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ACPI: NUMA: Fix typo in the full name of SRAT
[linux-2.6/btrfs-unstable.git] / fs / btrfs / inode.c
blob95c212037095fea727f4a35ea19d9d7e54ad8cfe
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/pagemap.h>
25 #include <linux/highmem.h>
26 #include <linux/time.h>
27 #include <linux/init.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mpage.h>
31 #include <linux/swap.h>
32 #include <linux/writeback.h>
33 #include <linux/compat.h>
34 #include <linux/bit_spinlock.h>
35 #include <linux/xattr.h>
36 #include <linux/posix_acl.h>
37 #include <linux/falloc.h>
38 #include <linux/slab.h>
39 #include <linux/ratelimit.h>
40 #include <linux/mount.h>
41 #include <linux/btrfs.h>
42 #include <linux/blkdev.h>
43 #include <linux/posix_acl_xattr.h>
44 #include <linux/uio.h>
45 #include "ctree.h"
46 #include "disk-io.h"
47 #include "transaction.h"
48 #include "btrfs_inode.h"
49 #include "print-tree.h"
50 #include "ordered-data.h"
51 #include "xattr.h"
52 #include "tree-log.h"
53 #include "volumes.h"
54 #include "compression.h"
55 #include "locking.h"
56 #include "free-space-cache.h"
57 #include "inode-map.h"
58 #include "backref.h"
59 #include "hash.h"
60 #include "props.h"
61 #include "qgroup.h"
62 #include "dedupe.h"
63
64 struct btrfs_iget_args {
65 struct btrfs_key *location;
66 struct btrfs_root *root;
67 };
68
69 struct btrfs_dio_data {
70 u64 outstanding_extents;
71 u64 reserve;
72 u64 unsubmitted_oe_range_start;
73 u64 unsubmitted_oe_range_end;
74 int overwrite;
75 };
76
77 static const struct inode_operations btrfs_dir_inode_operations;
78 static const struct inode_operations btrfs_symlink_inode_operations;
79 static const struct inode_operations btrfs_dir_ro_inode_operations;
80 static const struct inode_operations btrfs_special_inode_operations;
81 static const struct inode_operations btrfs_file_inode_operations;
82 static const struct address_space_operations btrfs_aops;
83 static const struct address_space_operations btrfs_symlink_aops;
84 static const struct file_operations btrfs_dir_file_operations;
85 static const struct extent_io_ops btrfs_extent_io_ops;
86
87 static struct kmem_cache *btrfs_inode_cachep;
88 struct kmem_cache *btrfs_trans_handle_cachep;
89 struct kmem_cache *btrfs_path_cachep;
90 struct kmem_cache *btrfs_free_space_cachep;
91
92 #define S_SHIFT 12
93 static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
94 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
95 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
96 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
97 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
98 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
99 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
100 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
101 };
102
103 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
104 static int btrfs_truncate(struct inode *inode);
105 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
106 static noinline int cow_file_range(struct inode *inode,
107 struct page *locked_page,
108 u64 start, u64 end, u64 delalloc_end,
109 int *page_started, unsigned long *nr_written,
110 int unlock, struct btrfs_dedupe_hash *hash);
111 static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
112 u64 orig_start, u64 block_start,
113 u64 block_len, u64 orig_block_len,
114 u64 ram_bytes, int compress_type,
115 int type);
116
117 static void __endio_write_update_ordered(struct inode *inode,
118 const u64 offset, const u64 bytes,
119 const bool uptodate);
120
121 /*
122 * Cleanup all submitted ordered extents in specified range to handle errors
123 * from the fill_dellaloc() callback.
124 *
125 * NOTE: caller must ensure that when an error happens, it can not call
126 * extent_clear_unlock_delalloc() to clear both the bits EXTENT_DO_ACCOUNTING
127 * and EXTENT_DELALLOC simultaneously, because that causes the reserved metadata
128 * to be released, which we want to happen only when finishing the ordered
129 * extent (btrfs_finish_ordered_io()). Also note that the caller of the
130 * fill_delalloc() callback already does proper cleanup for the first page of
131 * the range, that is, it invokes the callback writepage_end_io_hook() for the
132 * range of the first page.
133 */
134 static inline void btrfs_cleanup_ordered_extents(struct inode *inode,
135 const u64 offset,
136 const u64 bytes)
137 {
138 return __endio_write_update_ordered(inode, offset + PAGE_SIZE,
139 bytes - PAGE_SIZE, false);
140 }
141
142 static int btrfs_dirty_inode(struct inode *inode);
143
144 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
145 void btrfs_test_inode_set_ops(struct inode *inode)
146 {
147 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
148 }
149 #endif
150
151 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
152 struct inode *inode, struct inode *dir,
153 const struct qstr *qstr)
154 {
155 int err;
156
157 err = btrfs_init_acl(trans, inode, dir);
158 if (!err)
159 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
160 return err;
161 }
162
163 /*
164 * this does all the hard work for inserting an inline extent into
165 * the btree. The caller should have done a btrfs_drop_extents so that
166 * no overlapping inline items exist in the btree
167 */
168 static int insert_inline_extent(struct btrfs_trans_handle *trans,
169 struct btrfs_path *path, int extent_inserted,
170 struct btrfs_root *root, struct inode *inode,
171 u64 start, size_t size, size_t compressed_size,
172 int compress_type,
173 struct page **compressed_pages)
174 {
175 struct extent_buffer *leaf;
176 struct page *page = NULL;
177 char *kaddr;
178 unsigned long ptr;
179 struct btrfs_file_extent_item *ei;
180 int ret;
181 size_t cur_size = size;
182 unsigned long offset;
183
184 if (compressed_size && compressed_pages)
185 cur_size = compressed_size;
186
187 inode_add_bytes(inode, size);
188
189 if (!extent_inserted) {
190 struct btrfs_key key;
191 size_t datasize;
192
193 key.objectid = btrfs_ino(BTRFS_I(inode));
194 key.offset = start;
195 key.type = BTRFS_EXTENT_DATA_KEY;
196
197 datasize = btrfs_file_extent_calc_inline_size(cur_size);
198 path->leave_spinning = 1;
199 ret = btrfs_insert_empty_item(trans, root, path, &key,
200 datasize);
201 if (ret)
202 goto fail;
203 }
204 leaf = path->nodes[0];
205 ei = btrfs_item_ptr(leaf, path->slots[0],
206 struct btrfs_file_extent_item);
207 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
208 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
209 btrfs_set_file_extent_encryption(leaf, ei, 0);
210 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
211 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
212 ptr = btrfs_file_extent_inline_start(ei);
213
214 if (compress_type != BTRFS_COMPRESS_NONE) {
215 struct page *cpage;
216 int i = 0;
217 while (compressed_size > 0) {
218 cpage = compressed_pages[i];
219 cur_size = min_t(unsigned long, compressed_size,
220 PAGE_SIZE);
221
222 kaddr = kmap_atomic(cpage);
223 write_extent_buffer(leaf, kaddr, ptr, cur_size);
224 kunmap_atomic(kaddr);
225
226 i++;
227 ptr += cur_size;
228 compressed_size -= cur_size;
229 }
230 btrfs_set_file_extent_compression(leaf, ei,
231 compress_type);
232 } else {
233 page = find_get_page(inode->i_mapping,
234 start >> PAGE_SHIFT);
235 btrfs_set_file_extent_compression(leaf, ei, 0);
236 kaddr = kmap_atomic(page);
237 offset = start & (PAGE_SIZE - 1);
238 write_extent_buffer(leaf, kaddr + offset, ptr, size);
239 kunmap_atomic(kaddr);
240 put_page(page);
241 }
242 btrfs_mark_buffer_dirty(leaf);
243 btrfs_release_path(path);
244
245 /*
246 * we're an inline extent, so nobody can
247 * extend the file past i_size without locking
248 * a page we already have locked.
249 *
250 * We must do any isize and inode updates
251 * before we unlock the pages. Otherwise we
252 * could end up racing with unlink.
253 */
254 BTRFS_I(inode)->disk_i_size = inode->i_size;
255 ret = btrfs_update_inode(trans, root, inode);
256
257 fail:
258 return ret;
259 }
260
261
262 /*
263 * conditionally insert an inline extent into the file. This
264 * does the checks required to make sure the data is small enough
265 * to fit as an inline extent.
266 */
267 static noinline int cow_file_range_inline(struct btrfs_root *root,
268 struct inode *inode, u64 start,
269 u64 end, size_t compressed_size,
270 int compress_type,
271 struct page **compressed_pages)
272 {
273 struct btrfs_fs_info *fs_info = root->fs_info;
274 struct btrfs_trans_handle *trans;
275 u64 isize = i_size_read(inode);
276 u64 actual_end = min(end + 1, isize);
277 u64 inline_len = actual_end - start;
278 u64 aligned_end = ALIGN(end, fs_info->sectorsize);
279 u64 data_len = inline_len;
280 int ret;
281 struct btrfs_path *path;
282 int extent_inserted = 0;
283 u32 extent_item_size;
284
285 if (compressed_size)
286 data_len = compressed_size;
287
288 if (start > 0 ||
289 actual_end > fs_info->sectorsize ||
290 data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) ||
291 (!compressed_size &&
292 (actual_end & (fs_info->sectorsize - 1)) == 0) ||
293 end + 1 < isize ||
294 data_len > fs_info->max_inline) {
295 return 1;
296 }
297
298 path = btrfs_alloc_path();
299 if (!path)
300 return -ENOMEM;
301
302 trans = btrfs_join_transaction(root);
303 if (IS_ERR(trans)) {
304 btrfs_free_path(path);
305 return PTR_ERR(trans);
306 }
307 trans->block_rsv = &fs_info->delalloc_block_rsv;
308
309 if (compressed_size && compressed_pages)
310 extent_item_size = btrfs_file_extent_calc_inline_size(
311 compressed_size);
312 else
313 extent_item_size = btrfs_file_extent_calc_inline_size(
314 inline_len);
315
316 ret = __btrfs_drop_extents(trans, root, inode, path,
317 start, aligned_end, NULL,
318 1, 1, extent_item_size, &extent_inserted);
319 if (ret) {
320 btrfs_abort_transaction(trans, ret);
321 goto out;
322 }
323
324 if (isize > actual_end)
325 inline_len = min_t(u64, isize, actual_end);
326 ret = insert_inline_extent(trans, path, extent_inserted,
327 root, inode, start,
328 inline_len, compressed_size,
329 compress_type, compressed_pages);
330 if (ret && ret != -ENOSPC) {
331 btrfs_abort_transaction(trans, ret);
332 goto out;
333 } else if (ret == -ENOSPC) {
334 ret = 1;
335 goto out;
336 }
337
338 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
339 btrfs_delalloc_release_metadata(BTRFS_I(inode), end + 1 - start);
340 btrfs_drop_extent_cache(BTRFS_I(inode), start, aligned_end - 1, 0);
341 out:
342 /*
343 * Don't forget to free the reserved space, as for inlined extent
344 * it won't count as data extent, free them directly here.
345 * And at reserve time, it's always aligned to page size, so
346 * just free one page here.
347 */
348 btrfs_qgroup_free_data(inode, NULL, 0, PAGE_SIZE);
349 btrfs_free_path(path);
350 btrfs_end_transaction(trans);
351 return ret;
352 }
353
354 struct async_extent {
355 u64 start;
356 u64 ram_size;
357 u64 compressed_size;
358 struct page **pages;
359 unsigned long nr_pages;
360 int compress_type;
361 struct list_head list;
362 };
363
364 struct async_cow {
365 struct inode *inode;
366 struct btrfs_root *root;
367 struct page *locked_page;
368 u64 start;
369 u64 end;
370 struct list_head extents;
371 struct btrfs_work work;
372 };
373
374 static noinline int add_async_extent(struct async_cow *cow,
375 u64 start, u64 ram_size,
376 u64 compressed_size,
377 struct page **pages,
378 unsigned long nr_pages,
379 int compress_type)
380 {
381 struct async_extent *async_extent;
382
383 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
384 BUG_ON(!async_extent); /* -ENOMEM */
385 async_extent->start = start;
386 async_extent->ram_size = ram_size;
387 async_extent->compressed_size = compressed_size;
388 async_extent->pages = pages;
389 async_extent->nr_pages = nr_pages;
390 async_extent->compress_type = compress_type;
391 list_add_tail(&async_extent->list, &cow->extents);
392 return 0;
393 }
394
395 static inline int inode_need_compress(struct inode *inode)
396 {
397 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
398
399 /* force compress */
400 if (btrfs_test_opt(fs_info, FORCE_COMPRESS))
401 return 1;
402 /* bad compression ratios */
403 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
404 return 0;
405 if (btrfs_test_opt(fs_info, COMPRESS) ||
406 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
407 BTRFS_I(inode)->force_compress)
408 return 1;
409 return 0;
410 }
411
412 static inline void inode_should_defrag(struct btrfs_inode *inode,
413 u64 start, u64 end, u64 num_bytes, u64 small_write)
414 {
415 /* If this is a small write inside eof, kick off a defrag */
416 if (num_bytes < small_write &&
417 (start > 0 || end + 1 < inode->disk_i_size))
418 btrfs_add_inode_defrag(NULL, inode);
419 }
420
421 /*
422 * we create compressed extents in two phases. The first
423 * phase compresses a range of pages that have already been
424 * locked (both pages and state bits are locked).
425 *
426 * This is done inside an ordered work queue, and the compression
427 * is spread across many cpus. The actual IO submission is step
428 * two, and the ordered work queue takes care of making sure that
429 * happens in the same order things were put onto the queue by
430 * writepages and friends.
431 *
432 * If this code finds it can't get good compression, it puts an
433 * entry onto the work queue to write the uncompressed bytes. This
434 * makes sure that both compressed inodes and uncompressed inodes
435 * are written in the same order that the flusher thread sent them
436 * down.
437 */
438 static noinline void compress_file_range(struct inode *inode,
439 struct page *locked_page,
440 u64 start, u64 end,
441 struct async_cow *async_cow,
442 int *num_added)
443 {
444 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
445 struct btrfs_root *root = BTRFS_I(inode)->root;
446 u64 num_bytes;
447 u64 blocksize = fs_info->sectorsize;
448 u64 actual_end;
449 u64 isize = i_size_read(inode);
450 int ret = 0;
451 struct page **pages = NULL;
452 unsigned long nr_pages;
453 unsigned long total_compressed = 0;
454 unsigned long total_in = 0;
455 int i;
456 int will_compress;
457 int compress_type = fs_info->compress_type;
458 int redirty = 0;
459
460 inode_should_defrag(BTRFS_I(inode), start, end, end - start + 1,
461 SZ_16K);
462
463 actual_end = min_t(u64, isize, end + 1);
464 again:
465 will_compress = 0;
466 nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
467 BUILD_BUG_ON((BTRFS_MAX_COMPRESSED % PAGE_SIZE) != 0);
468 nr_pages = min_t(unsigned long, nr_pages,
469 BTRFS_MAX_COMPRESSED / PAGE_SIZE);
470
471 /*
472 * we don't want to send crud past the end of i_size through
473 * compression, that's just a waste of CPU time. So, if the
474 * end of the file is before the start of our current
475 * requested range of bytes, we bail out to the uncompressed
476 * cleanup code that can deal with all of this.
477 *
478 * It isn't really the fastest way to fix things, but this is a
479 * very uncommon corner.
480 */
481 if (actual_end <= start)
482 goto cleanup_and_bail_uncompressed;
483
484 total_compressed = actual_end - start;
485
486 /*
487 * skip compression for a small file range(<=blocksize) that
488 * isn't an inline extent, since it doesn't save disk space at all.
489 */
490 if (total_compressed <= blocksize &&
491 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
492 goto cleanup_and_bail_uncompressed;
493
494 total_compressed = min_t(unsigned long, total_compressed,
495 BTRFS_MAX_UNCOMPRESSED);
496 num_bytes = ALIGN(end - start + 1, blocksize);
497 num_bytes = max(blocksize, num_bytes);
498 total_in = 0;
499 ret = 0;
500
501 /*
502 * we do compression for mount -o compress and when the
503 * inode has not been flagged as nocompress. This flag can
504 * change at any time if we discover bad compression ratios.
505 */
506 if (inode_need_compress(inode)) {
507 WARN_ON(pages);
508 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
509 if (!pages) {
510 /* just bail out to the uncompressed code */
511 goto cont;
512 }
513
514 if (BTRFS_I(inode)->force_compress)
515 compress_type = BTRFS_I(inode)->force_compress;
516
517 /*
518 * we need to call clear_page_dirty_for_io on each
519 * page in the range. Otherwise applications with the file
520 * mmap'd can wander in and change the page contents while
521 * we are compressing them.
522 *
523 * If the compression fails for any reason, we set the pages
524 * dirty again later on.
525 */
526 extent_range_clear_dirty_for_io(inode, start, end);
527 redirty = 1;
528 ret = btrfs_compress_pages(compress_type,
529 inode->i_mapping, start,
530 pages,
531 &nr_pages,
532 &total_in,
533 &total_compressed);
534
535 if (!ret) {
536 unsigned long offset = total_compressed &
537 (PAGE_SIZE - 1);
538 struct page *page = pages[nr_pages - 1];
539 char *kaddr;
540
541 /* zero the tail end of the last page, we might be
542 * sending it down to disk
543 */
544 if (offset) {
545 kaddr = kmap_atomic(page);
546 memset(kaddr + offset, 0,
547 PAGE_SIZE - offset);
548 kunmap_atomic(kaddr);
549 }
550 will_compress = 1;
551 }
552 }
553 cont:
554 if (start == 0) {
555 /* lets try to make an inline extent */
556 if (ret || total_in < (actual_end - start)) {
557 /* we didn't compress the entire range, try
558 * to make an uncompressed inline extent.
559 */
560 ret = cow_file_range_inline(root, inode, start, end,
561 0, BTRFS_COMPRESS_NONE, NULL);
562 } else {
563 /* try making a compressed inline extent */
564 ret = cow_file_range_inline(root, inode, start, end,
565 total_compressed,
566 compress_type, pages);
567 }
568 if (ret <= 0) {
569 unsigned long clear_flags = EXTENT_DELALLOC |
570 EXTENT_DELALLOC_NEW | EXTENT_DEFRAG;
571 unsigned long page_error_op;
572
573 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0;
574 page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
575
576 /*
577 * inline extent creation worked or returned error,
578 * we don't need to create any more async work items.
579 * Unlock and free up our temp pages.
580 */
581 extent_clear_unlock_delalloc(inode, start, end, end,
582 NULL, clear_flags,
583 PAGE_UNLOCK |
584 PAGE_CLEAR_DIRTY |
585 PAGE_SET_WRITEBACK |
586 page_error_op |
587 PAGE_END_WRITEBACK);
588 if (ret == 0)
589 btrfs_free_reserved_data_space_noquota(inode,
590 start,
591 end - start + 1);
592 goto free_pages_out;
593 }
594 }
595
596 if (will_compress) {
597 /*
598 * we aren't doing an inline extent round the compressed size
599 * up to a block size boundary so the allocator does sane
600 * things
601 */
602 total_compressed = ALIGN(total_compressed, blocksize);
603
604 /*
605 * one last check to make sure the compression is really a
606 * win, compare the page count read with the blocks on disk,
607 * compression must free at least one sector size
608 */
609 total_in = ALIGN(total_in, PAGE_SIZE);
610 if (total_compressed + blocksize <= total_in) {
611 num_bytes = total_in;
612 *num_added += 1;
613
614 /*
615 * The async work queues will take care of doing actual
616 * allocation on disk for these compressed pages, and
617 * will submit them to the elevator.
618 */
619 add_async_extent(async_cow, start, num_bytes,
620 total_compressed, pages, nr_pages,
621 compress_type);
622
623 if (start + num_bytes < end) {
624 start += num_bytes;
625 pages = NULL;
626 cond_resched();
627 goto again;
628 }
629 return;
630 }
631 }
632 if (pages) {
633 /*
634 * the compression code ran but failed to make things smaller,
635 * free any pages it allocated and our page pointer array
636 */
637 for (i = 0; i < nr_pages; i++) {
638 WARN_ON(pages[i]->mapping);
639 put_page(pages[i]);
640 }
641 kfree(pages);
642 pages = NULL;
643 total_compressed = 0;
644 nr_pages = 0;
645
646 /* flag the file so we don't compress in the future */
647 if (!btrfs_test_opt(fs_info, FORCE_COMPRESS) &&
648 !(BTRFS_I(inode)->force_compress)) {
649 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
650 }
651 }
652 cleanup_and_bail_uncompressed:
653 /*
654 * No compression, but we still need to write the pages in the file
655 * we've been given so far. redirty the locked page if it corresponds
656 * to our extent and set things up for the async work queue to run
657 * cow_file_range to do the normal delalloc dance.
658 */
659 if (page_offset(locked_page) >= start &&
660 page_offset(locked_page) <= end)
661 __set_page_dirty_nobuffers(locked_page);
662 /* unlocked later on in the async handlers */
663
664 if (redirty)
665 extent_range_redirty_for_io(inode, start, end);
666 add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0,
667 BTRFS_COMPRESS_NONE);
668 *num_added += 1;
669
670 return;
671
672 free_pages_out:
673 for (i = 0; i < nr_pages; i++) {
674 WARN_ON(pages[i]->mapping);
675 put_page(pages[i]);
676 }
677 kfree(pages);
678 }
679
680 static void free_async_extent_pages(struct async_extent *async_extent)
681 {
682 int i;
683
684 if (!async_extent->pages)
685 return;
686
687 for (i = 0; i < async_extent->nr_pages; i++) {
688 WARN_ON(async_extent->pages[i]->mapping);
689 put_page(async_extent->pages[i]);
690 }
691 kfree(async_extent->pages);
692 async_extent->nr_pages = 0;
693 async_extent->pages = NULL;
694 }
695
696 /*
697 * phase two of compressed writeback. This is the ordered portion
698 * of the code, which only gets called in the order the work was
699 * queued. We walk all the async extents created by compress_file_range
700 * and send them down to the disk.
701 */
702 static noinline void submit_compressed_extents(struct inode *inode,
703 struct async_cow *async_cow)
704 {
705 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
706 struct async_extent *async_extent;
707 u64 alloc_hint = 0;
708 struct btrfs_key ins;
709 struct extent_map *em;
710 struct btrfs_root *root = BTRFS_I(inode)->root;
711 struct extent_io_tree *io_tree;
712 int ret = 0;
713
714 again:
715 while (!list_empty(&async_cow->extents)) {
716 async_extent = list_entry(async_cow->extents.next,
717 struct async_extent, list);
718 list_del(&async_extent->list);
719
720 io_tree = &BTRFS_I(inode)->io_tree;
721
722 retry:
723 /* did the compression code fall back to uncompressed IO? */
724 if (!async_extent->pages) {
725 int page_started = 0;
726 unsigned long nr_written = 0;
727
728 lock_extent(io_tree, async_extent->start,
729 async_extent->start +
730 async_extent->ram_size - 1);
731
732 /* allocate blocks */
733 ret = cow_file_range(inode, async_cow->locked_page,
734 async_extent->start,
735 async_extent->start +
736 async_extent->ram_size - 1,
737 async_extent->start +
738 async_extent->ram_size - 1,
739 &page_started, &nr_written, 0,
740 NULL);
741
742 /* JDM XXX */
743
744 /*
745 * if page_started, cow_file_range inserted an
746 * inline extent and took care of all the unlocking
747 * and IO for us. Otherwise, we need to submit
748 * all those pages down to the drive.
749 */
750 if (!page_started && !ret)
751 extent_write_locked_range(io_tree,
752 inode, async_extent->start,
753 async_extent->start +
754 async_extent->ram_size - 1,
755 btrfs_get_extent,
756 WB_SYNC_ALL);
757 else if (ret)
758 unlock_page(async_cow->locked_page);
759 kfree(async_extent);
760 cond_resched();
761 continue;
762 }
763
764 lock_extent(io_tree, async_extent->start,
765 async_extent->start + async_extent->ram_size - 1);
766
767 ret = btrfs_reserve_extent(root, async_extent->ram_size,
768 async_extent->compressed_size,
769 async_extent->compressed_size,
770 0, alloc_hint, &ins, 1, 1);
771 if (ret) {
772 free_async_extent_pages(async_extent);
773
774 if (ret == -ENOSPC) {
775 unlock_extent(io_tree, async_extent->start,
776 async_extent->start +
777 async_extent->ram_size - 1);
778
779 /*
780 * we need to redirty the pages if we decide to
781 * fallback to uncompressed IO, otherwise we
782 * will not submit these pages down to lower
783 * layers.
784 */
785 extent_range_redirty_for_io(inode,
786 async_extent->start,
787 async_extent->start +
788 async_extent->ram_size - 1);
789
790 goto retry;
791 }
792 goto out_free;
793 }
794 /*
795 * here we're doing allocation and writeback of the
796 * compressed pages
797 */
798 em = create_io_em(inode, async_extent->start,
799 async_extent->ram_size, /* len */
800 async_extent->start, /* orig_start */
801 ins.objectid, /* block_start */
802 ins.offset, /* block_len */
803 ins.offset, /* orig_block_len */
804 async_extent->ram_size, /* ram_bytes */
805 async_extent->compress_type,
806 BTRFS_ORDERED_COMPRESSED);
807 if (IS_ERR(em))
808 /* ret value is not necessary due to void function */
809 goto out_free_reserve;
810 free_extent_map(em);
811
812 ret = btrfs_add_ordered_extent_compress(inode,
813 async_extent->start,
814 ins.objectid,
815 async_extent->ram_size,
816 ins.offset,
817 BTRFS_ORDERED_COMPRESSED,
818 async_extent->compress_type);
819 if (ret) {
820 btrfs_drop_extent_cache(BTRFS_I(inode),
821 async_extent->start,
822 async_extent->start +
823 async_extent->ram_size - 1, 0);
824 goto out_free_reserve;
825 }
826 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
827
828 /*
829 * clear dirty, set writeback and unlock the pages.
830 */
831 extent_clear_unlock_delalloc(inode, async_extent->start,
832 async_extent->start +
833 async_extent->ram_size - 1,
834 async_extent->start +
835 async_extent->ram_size - 1,
836 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
837 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
838 PAGE_SET_WRITEBACK);
839 if (btrfs_submit_compressed_write(inode,
840 async_extent->start,
841 async_extent->ram_size,
842 ins.objectid,
843 ins.offset, async_extent->pages,
844 async_extent->nr_pages)) {
845 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
846 struct page *p = async_extent->pages[0];
847 const u64 start = async_extent->start;
848 const u64 end = start + async_extent->ram_size - 1;
849
850 p->mapping = inode->i_mapping;
851 tree->ops->writepage_end_io_hook(p, start, end,
852 NULL, 0);
853 p->mapping = NULL;
854 extent_clear_unlock_delalloc(inode, start, end, end,
855 NULL, 0,
856 PAGE_END_WRITEBACK |
857 PAGE_SET_ERROR);
858 free_async_extent_pages(async_extent);
859 }
860 alloc_hint = ins.objectid + ins.offset;
861 kfree(async_extent);
862 cond_resched();
863 }
864 return;
865 out_free_reserve:
866 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
867 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
868 out_free:
869 extent_clear_unlock_delalloc(inode, async_extent->start,
870 async_extent->start +
871 async_extent->ram_size - 1,
872 async_extent->start +
873 async_extent->ram_size - 1,
874 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
875 EXTENT_DELALLOC_NEW |
876 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
877 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
878 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
879 PAGE_SET_ERROR);
880 free_async_extent_pages(async_extent);
881 kfree(async_extent);
882 goto again;
883 }
884
885 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
886 u64 num_bytes)
887 {
888 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
889 struct extent_map *em;
890 u64 alloc_hint = 0;
891
892 read_lock(&em_tree->lock);
893 em = search_extent_mapping(em_tree, start, num_bytes);
894 if (em) {
895 /*
896 * if block start isn't an actual block number then find the
897 * first block in this inode and use that as a hint. If that
898 * block is also bogus then just don't worry about it.
899 */
900 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
901 free_extent_map(em);
902 em = search_extent_mapping(em_tree, 0, 0);
903 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
904 alloc_hint = em->block_start;
905 if (em)
906 free_extent_map(em);
907 } else {
908 alloc_hint = em->block_start;
909 free_extent_map(em);
910 }
911 }
912 read_unlock(&em_tree->lock);
913
914 return alloc_hint;
915 }
916
917 /*
918 * when extent_io.c finds a delayed allocation range in the file,
919 * the call backs end up in this code. The basic idea is to
920 * allocate extents on disk for the range, and create ordered data structs
921 * in ram to track those extents.
922 *
923 * locked_page is the page that writepage had locked already. We use
924 * it to make sure we don't do extra locks or unlocks.
925 *
926 * *page_started is set to one if we unlock locked_page and do everything
927 * required to start IO on it. It may be clean and already done with
928 * IO when we return.
929 */
930 static noinline int cow_file_range(struct inode *inode,
931 struct page *locked_page,
932 u64 start, u64 end, u64 delalloc_end,
933 int *page_started, unsigned long *nr_written,
934 int unlock, struct btrfs_dedupe_hash *hash)
935 {
936 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
937 struct btrfs_root *root = BTRFS_I(inode)->root;
938 u64 alloc_hint = 0;
939 u64 num_bytes;
940 unsigned long ram_size;
941 u64 disk_num_bytes;
942 u64 cur_alloc_size = 0;
943 u64 blocksize = fs_info->sectorsize;
944 struct btrfs_key ins;
945 struct extent_map *em;
946 unsigned clear_bits;
947 unsigned long page_ops;
948 bool extent_reserved = false;
949 int ret = 0;
950
951 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
952 WARN_ON_ONCE(1);
953 ret = -EINVAL;
954 goto out_unlock;
955 }
956
957 num_bytes = ALIGN(end - start + 1, blocksize);
958 num_bytes = max(blocksize, num_bytes);
959 disk_num_bytes = num_bytes;
960
961 inode_should_defrag(BTRFS_I(inode), start, end, num_bytes, SZ_64K);
962
963 if (start == 0) {
964 /* lets try to make an inline extent */
965 ret = cow_file_range_inline(root, inode, start, end, 0,
966 BTRFS_COMPRESS_NONE, NULL);
967 if (ret == 0) {
968 extent_clear_unlock_delalloc(inode, start, end,
969 delalloc_end, NULL,
970 EXTENT_LOCKED | EXTENT_DELALLOC |
971 EXTENT_DELALLOC_NEW |
972 EXTENT_DEFRAG, PAGE_UNLOCK |
973 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
974 PAGE_END_WRITEBACK);
975 btrfs_free_reserved_data_space_noquota(inode, start,
976 end - start + 1);
977 *nr_written = *nr_written +
978 (end - start + PAGE_SIZE) / PAGE_SIZE;
979 *page_started = 1;
980 goto out;
981 } else if (ret < 0) {
982 goto out_unlock;
983 }
984 }
985
986 BUG_ON(disk_num_bytes >
987 btrfs_super_total_bytes(fs_info->super_copy));
988
989 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
990 btrfs_drop_extent_cache(BTRFS_I(inode), start,
991 start + num_bytes - 1, 0);
992
993 while (disk_num_bytes > 0) {
994 cur_alloc_size = disk_num_bytes;
995 ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size,
996 fs_info->sectorsize, 0, alloc_hint,
997 &ins, 1, 1);
998 if (ret < 0)
999 goto out_unlock;
1000 cur_alloc_size = ins.offset;
1001 extent_reserved = true;
1002
1003 ram_size = ins.offset;
1004 em = create_io_em(inode, start, ins.offset, /* len */
1005 start, /* orig_start */
1006 ins.objectid, /* block_start */
1007 ins.offset, /* block_len */
1008 ins.offset, /* orig_block_len */
1009 ram_size, /* ram_bytes */
1010 BTRFS_COMPRESS_NONE, /* compress_type */
1011 BTRFS_ORDERED_REGULAR /* type */);
1012 if (IS_ERR(em))
1013 goto out_reserve;
1014 free_extent_map(em);
1015
1016 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
1017 ram_size, cur_alloc_size, 0);
1018 if (ret)
1019 goto out_drop_extent_cache;
1020
1021 if (root->root_key.objectid ==
1022 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1023 ret = btrfs_reloc_clone_csums(inode, start,
1024 cur_alloc_size);
1025 /*
1026 * Only drop cache here, and process as normal.
1027 *
1028 * We must not allow extent_clear_unlock_delalloc()
1029 * at out_unlock label to free meta of this ordered
1030 * extent, as its meta should be freed by
1031 * btrfs_finish_ordered_io().
1032 *
1033 * So we must continue until @start is increased to
1034 * skip current ordered extent.
1035 */
1036 if (ret)
1037 btrfs_drop_extent_cache(BTRFS_I(inode), start,
1038 start + ram_size - 1, 0);
1039 }
1040
1041 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1042
1043 /* we're not doing compressed IO, don't unlock the first
1044 * page (which the caller expects to stay locked), don't
1045 * clear any dirty bits and don't set any writeback bits
1046 *
1047 * Do set the Private2 bit so we know this page was properly
1048 * setup for writepage
1049 */
1050 page_ops = unlock ? PAGE_UNLOCK : 0;
1051 page_ops |= PAGE_SET_PRIVATE2;
1052
1053 extent_clear_unlock_delalloc(inode, start,
1054 start + ram_size - 1,
1055 delalloc_end, locked_page,
1056 EXTENT_LOCKED | EXTENT_DELALLOC,
1057 page_ops);
1058 if (disk_num_bytes < cur_alloc_size)
1059 disk_num_bytes = 0;
1060 else
1061 disk_num_bytes -= cur_alloc_size;
1062 num_bytes -= cur_alloc_size;
1063 alloc_hint = ins.objectid + ins.offset;
1064 start += cur_alloc_size;
1065 extent_reserved = false;
1066
1067 /*
1068 * btrfs_reloc_clone_csums() error, since start is increased
1069 * extent_clear_unlock_delalloc() at out_unlock label won't
1070 * free metadata of current ordered extent, we're OK to exit.
1071 */
1072 if (ret)
1073 goto out_unlock;
1074 }
1075 out:
1076 return ret;
1077
1078 out_drop_extent_cache:
1079 btrfs_drop_extent_cache(BTRFS_I(inode), start, start + ram_size - 1, 0);
1080 out_reserve:
1081 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1082 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
1083 out_unlock:
1084 clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
1085 EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV;
1086 page_ops = PAGE_UNLOCK | PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
1087 PAGE_END_WRITEBACK;
1088 /*
1089 * If we reserved an extent for our delalloc range (or a subrange) and
1090 * failed to create the respective ordered extent, then it means that
1091 * when we reserved the extent we decremented the extent's size from
1092 * the data space_info's bytes_may_use counter and incremented the
1093 * space_info's bytes_reserved counter by the same amount. We must make
1094 * sure extent_clear_unlock_delalloc() does not try to decrement again
1095 * the data space_info's bytes_may_use counter, therefore we do not pass
1096 * it the flag EXTENT_CLEAR_DATA_RESV.
1097 */
1098 if (extent_reserved) {
1099 extent_clear_unlock_delalloc(inode, start,
1100 start + cur_alloc_size,
1101 start + cur_alloc_size,
1102 locked_page,
1103 clear_bits,
1104 page_ops);
1105 start += cur_alloc_size;
1106 if (start >= end)
1107 goto out;
1108 }
1109 extent_clear_unlock_delalloc(inode, start, end, delalloc_end,
1110 locked_page,
1111 clear_bits | EXTENT_CLEAR_DATA_RESV,
1112 page_ops);
1113 goto out;
1114 }
1115
1116 /*
1117 * work queue call back to started compression on a file and pages
1118 */
1119 static noinline void async_cow_start(struct btrfs_work *work)
1120 {
1121 struct async_cow *async_cow;
1122 int num_added = 0;
1123 async_cow = container_of(work, struct async_cow, work);
1124
1125 compress_file_range(async_cow->inode, async_cow->locked_page,
1126 async_cow->start, async_cow->end, async_cow,
1127 &num_added);
1128 if (num_added == 0) {
1129 btrfs_add_delayed_iput(async_cow->inode);
1130 async_cow->inode = NULL;
1131 }
1132 }
1133
1134 /*
1135 * work queue call back to submit previously compressed pages
1136 */
1137 static noinline void async_cow_submit(struct btrfs_work *work)
1138 {
1139 struct btrfs_fs_info *fs_info;
1140 struct async_cow *async_cow;
1141 struct btrfs_root *root;
1142 unsigned long nr_pages;
1143
1144 async_cow = container_of(work, struct async_cow, work);
1145
1146 root = async_cow->root;
1147 fs_info = root->fs_info;
1148 nr_pages = (async_cow->end - async_cow->start + PAGE_SIZE) >>
1149 PAGE_SHIFT;
1150
1151 /*
1152 * atomic_sub_return implies a barrier for waitqueue_active
1153 */
1154 if (atomic_sub_return(nr_pages, &fs_info->async_delalloc_pages) <
1155 5 * SZ_1M &&
1156 waitqueue_active(&fs_info->async_submit_wait))
1157 wake_up(&fs_info->async_submit_wait);
1158
1159 if (async_cow->inode)
1160 submit_compressed_extents(async_cow->inode, async_cow);
1161 }
1162
1163 static noinline void async_cow_free(struct btrfs_work *work)
1164 {
1165 struct async_cow *async_cow;
1166 async_cow = container_of(work, struct async_cow, work);
1167 if (async_cow->inode)
1168 btrfs_add_delayed_iput(async_cow->inode);
1169 kfree(async_cow);
1170 }
1171
1172 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1173 u64 start, u64 end, int *page_started,
1174 unsigned long *nr_written)
1175 {
1176 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1177 struct async_cow *async_cow;
1178 struct btrfs_root *root = BTRFS_I(inode)->root;
1179 unsigned long nr_pages;
1180 u64 cur_end;
1181
1182 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1183 1, 0, NULL, GFP_NOFS);
1184 while (start < end) {
1185 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1186 BUG_ON(!async_cow); /* -ENOMEM */
1187 async_cow->inode = igrab(inode);
1188 async_cow->root = root;
1189 async_cow->locked_page = locked_page;
1190 async_cow->start = start;
1191
1192 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
1193 !btrfs_test_opt(fs_info, FORCE_COMPRESS))
1194 cur_end = end;
1195 else
1196 cur_end = min(end, start + SZ_512K - 1);
1197
1198 async_cow->end = cur_end;
1199 INIT_LIST_HEAD(&async_cow->extents);
1200
1201 btrfs_init_work(&async_cow->work,
1202 btrfs_delalloc_helper,
1203 async_cow_start, async_cow_submit,
1204 async_cow_free);
1205
1206 nr_pages = (cur_end - start + PAGE_SIZE) >>
1207 PAGE_SHIFT;
1208 atomic_add(nr_pages, &fs_info->async_delalloc_pages);
1209
1210 btrfs_queue_work(fs_info->delalloc_workers, &async_cow->work);
1211
1212 while (atomic_read(&fs_info->async_submit_draining) &&
1213 atomic_read(&fs_info->async_delalloc_pages)) {
1214 wait_event(fs_info->async_submit_wait,
1215 (atomic_read(&fs_info->async_delalloc_pages) ==
1216 0));
1217 }
1218
1219 *nr_written += nr_pages;
1220 start = cur_end + 1;
1221 }
1222 *page_started = 1;
1223 return 0;
1224 }
1225
1226 static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info,
1227 u64 bytenr, u64 num_bytes)
1228 {
1229 int ret;
1230 struct btrfs_ordered_sum *sums;
1231 LIST_HEAD(list);
1232
1233 ret = btrfs_lookup_csums_range(fs_info->csum_root, bytenr,
1234 bytenr + num_bytes - 1, &list, 0);
1235 if (ret == 0 && list_empty(&list))
1236 return 0;
1237
1238 while (!list_empty(&list)) {
1239 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1240 list_del(&sums->list);
1241 kfree(sums);
1242 }
1243 return 1;
1244 }
1245
1246 /*
1247 * when nowcow writeback call back. This checks for snapshots or COW copies
1248 * of the extents that exist in the file, and COWs the file as required.
1249 *
1250 * If no cow copies or snapshots exist, we write directly to the existing
1251 * blocks on disk
1252 */
1253 static noinline int run_delalloc_nocow(struct inode *inode,
1254 struct page *locked_page,
1255 u64 start, u64 end, int *page_started, int force,
1256 unsigned long *nr_written)
1257 {
1258 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1259 struct btrfs_root *root = BTRFS_I(inode)->root;
1260 struct extent_buffer *leaf;
1261 struct btrfs_path *path;
1262 struct btrfs_file_extent_item *fi;
1263 struct btrfs_key found_key;
1264 struct extent_map *em;
1265 u64 cow_start;
1266 u64 cur_offset;
1267 u64 extent_end;
1268 u64 extent_offset;
1269 u64 disk_bytenr;
1270 u64 num_bytes;
1271 u64 disk_num_bytes;
1272 u64 ram_bytes;
1273 int extent_type;
1274 int ret, err;
1275 int type;
1276 int nocow;
1277 int check_prev = 1;
1278 bool nolock;
1279 u64 ino = btrfs_ino(BTRFS_I(inode));
1280
1281 path = btrfs_alloc_path();
1282 if (!path) {
1283 extent_clear_unlock_delalloc(inode, start, end, end,
1284 locked_page,
1285 EXTENT_LOCKED | EXTENT_DELALLOC |
1286 EXTENT_DO_ACCOUNTING |
1287 EXTENT_DEFRAG, PAGE_UNLOCK |
1288 PAGE_CLEAR_DIRTY |
1289 PAGE_SET_WRITEBACK |
1290 PAGE_END_WRITEBACK);
1291 return -ENOMEM;
1292 }
1293
1294 nolock = btrfs_is_free_space_inode(BTRFS_I(inode));
1295
1296 cow_start = (u64)-1;
1297 cur_offset = start;
1298 while (1) {
1299 ret = btrfs_lookup_file_extent(NULL, root, path, ino,
1300 cur_offset, 0);
1301 if (ret < 0)
1302 goto error;
1303 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1304 leaf = path->nodes[0];
1305 btrfs_item_key_to_cpu(leaf, &found_key,
1306 path->slots[0] - 1);
1307 if (found_key.objectid == ino &&
1308 found_key.type == BTRFS_EXTENT_DATA_KEY)
1309 path->slots[0]--;
1310 }
1311 check_prev = 0;
1312 next_slot:
1313 leaf = path->nodes[0];
1314 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1315 ret = btrfs_next_leaf(root, path);
1316 if (ret < 0)
1317 goto error;
1318 if (ret > 0)
1319 break;
1320 leaf = path->nodes[0];
1321 }
1322
1323 nocow = 0;
1324 disk_bytenr = 0;
1325 num_bytes = 0;
1326 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1327
1328 if (found_key.objectid > ino)
1329 break;
1330 if (WARN_ON_ONCE(found_key.objectid < ino) ||
1331 found_key.type < BTRFS_EXTENT_DATA_KEY) {
1332 path->slots[0]++;
1333 goto next_slot;
1334 }
1335 if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
1336 found_key.offset > end)
1337 break;
1338
1339 if (found_key.offset > cur_offset) {
1340 extent_end = found_key.offset;
1341 extent_type = 0;
1342 goto out_check;
1343 }
1344
1345 fi = btrfs_item_ptr(leaf, path->slots[0],
1346 struct btrfs_file_extent_item);
1347 extent_type = btrfs_file_extent_type(leaf, fi);
1348
1349 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1350 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1351 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1352 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1353 extent_offset = btrfs_file_extent_offset(leaf, fi);
1354 extent_end = found_key.offset +
1355 btrfs_file_extent_num_bytes(leaf, fi);
1356 disk_num_bytes =
1357 btrfs_file_extent_disk_num_bytes(leaf, fi);
1358 if (extent_end <= start) {
1359 path->slots[0]++;
1360 goto next_slot;
1361 }
1362 if (disk_bytenr == 0)
1363 goto out_check;
1364 if (btrfs_file_extent_compression(leaf, fi) ||
1365 btrfs_file_extent_encryption(leaf, fi) ||
1366 btrfs_file_extent_other_encoding(leaf, fi))
1367 goto out_check;
1368 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1369 goto out_check;
1370 if (btrfs_extent_readonly(fs_info, disk_bytenr))
1371 goto out_check;
1372 if (btrfs_cross_ref_exist(root, ino,
1373 found_key.offset -
1374 extent_offset, disk_bytenr))
1375 goto out_check;
1376 disk_bytenr += extent_offset;
1377 disk_bytenr += cur_offset - found_key.offset;
1378 num_bytes = min(end + 1, extent_end) - cur_offset;
1379 /*
1380 * if there are pending snapshots for this root,
1381 * we fall into common COW way.
1382 */
1383 if (!nolock) {
1384 err = btrfs_start_write_no_snapshoting(root);
1385 if (!err)
1386 goto out_check;
1387 }
1388 /*
1389 * force cow if csum exists in the range.
1390 * this ensure that csum for a given extent are
1391 * either valid or do not exist.
1392 */
1393 if (csum_exist_in_range(fs_info, disk_bytenr,
1394 num_bytes)) {
1395 if (!nolock)
1396 btrfs_end_write_no_snapshoting(root);
1397 goto out_check;
1398 }
1399 if (!btrfs_inc_nocow_writers(fs_info, disk_bytenr)) {
1400 if (!nolock)
1401 btrfs_end_write_no_snapshoting(root);
1402 goto out_check;
1403 }
1404 nocow = 1;
1405 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1406 extent_end = found_key.offset +
1407 btrfs_file_extent_inline_len(leaf,
1408 path->slots[0], fi);
1409 extent_end = ALIGN(extent_end,
1410 fs_info->sectorsize);
1411 } else {
1412 BUG_ON(1);
1413 }
1414 out_check:
1415 if (extent_end <= start) {
1416 path->slots[0]++;
1417 if (!nolock && nocow)
1418 btrfs_end_write_no_snapshoting(root);
1419 if (nocow)
1420 btrfs_dec_nocow_writers(fs_info, disk_bytenr);
1421 goto next_slot;
1422 }
1423 if (!nocow) {
1424 if (cow_start == (u64)-1)
1425 cow_start = cur_offset;
1426 cur_offset = extent_end;
1427 if (cur_offset > end)
1428 break;
1429 path->slots[0]++;
1430 goto next_slot;
1431 }
1432
1433 btrfs_release_path(path);
1434 if (cow_start != (u64)-1) {
1435 ret = cow_file_range(inode, locked_page,
1436 cow_start, found_key.offset - 1,
1437 end, page_started, nr_written, 1,
1438 NULL);
1439 if (ret) {
1440 if (!nolock && nocow)
1441 btrfs_end_write_no_snapshoting(root);
1442 if (nocow)
1443 btrfs_dec_nocow_writers(fs_info,
1444 disk_bytenr);
1445 goto error;
1446 }
1447 cow_start = (u64)-1;
1448 }
1449
1450 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1451 u64 orig_start = found_key.offset - extent_offset;
1452
1453 em = create_io_em(inode, cur_offset, num_bytes,
1454 orig_start,
1455 disk_bytenr, /* block_start */
1456 num_bytes, /* block_len */
1457 disk_num_bytes, /* orig_block_len */
1458 ram_bytes, BTRFS_COMPRESS_NONE,
1459 BTRFS_ORDERED_PREALLOC);
1460 if (IS_ERR(em)) {
1461 if (!nolock && nocow)
1462 btrfs_end_write_no_snapshoting(root);
1463 if (nocow)
1464 btrfs_dec_nocow_writers(fs_info,
1465 disk_bytenr);
1466 ret = PTR_ERR(em);
1467 goto error;
1468 }
1469 free_extent_map(em);
1470 }
1471
1472 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1473 type = BTRFS_ORDERED_PREALLOC;
1474 } else {
1475 type = BTRFS_ORDERED_NOCOW;
1476 }
1477
1478 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1479 num_bytes, num_bytes, type);
1480 if (nocow)
1481 btrfs_dec_nocow_writers(fs_info, disk_bytenr);
1482 BUG_ON(ret); /* -ENOMEM */
1483
1484 if (root->root_key.objectid ==
1485 BTRFS_DATA_RELOC_TREE_OBJECTID)
1486 /*
1487 * Error handled later, as we must prevent
1488 * extent_clear_unlock_delalloc() in error handler
1489 * from freeing metadata of created ordered extent.
1490 */
1491 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1492 num_bytes);
1493
1494 extent_clear_unlock_delalloc(inode, cur_offset,
1495 cur_offset + num_bytes - 1, end,
1496 locked_page, EXTENT_LOCKED |
1497 EXTENT_DELALLOC |
1498 EXTENT_CLEAR_DATA_RESV,
1499 PAGE_UNLOCK | PAGE_SET_PRIVATE2);
1500
1501 if (!nolock && nocow)
1502 btrfs_end_write_no_snapshoting(root);
1503 cur_offset = extent_end;
1504
1505 /*
1506 * btrfs_reloc_clone_csums() error, now we're OK to call error
1507 * handler, as metadata for created ordered extent will only
1508 * be freed by btrfs_finish_ordered_io().
1509 */
1510 if (ret)
1511 goto error;
1512 if (cur_offset > end)
1513 break;
1514 }
1515 btrfs_release_path(path);
1516
1517 if (cur_offset <= end && cow_start == (u64)-1) {
1518 cow_start = cur_offset;
1519 cur_offset = end;
1520 }
1521
1522 if (cow_start != (u64)-1) {
1523 ret = cow_file_range(inode, locked_page, cow_start, end, end,
1524 page_started, nr_written, 1, NULL);
1525 if (ret)
1526 goto error;
1527 }
1528
1529 error:
1530 if (ret && cur_offset < end)
1531 extent_clear_unlock_delalloc(inode, cur_offset, end, end,
1532 locked_page, EXTENT_LOCKED |
1533 EXTENT_DELALLOC | EXTENT_DEFRAG |
1534 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1535 PAGE_CLEAR_DIRTY |
1536 PAGE_SET_WRITEBACK |
1537 PAGE_END_WRITEBACK);
1538 btrfs_free_path(path);
1539 return ret;
1540 }
1541
1542 static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
1543 {
1544
1545 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
1546 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
1547 return 0;
1548
1549 /*
1550 * @defrag_bytes is a hint value, no spinlock held here,
1551 * if is not zero, it means the file is defragging.
1552 * Force cow if given extent needs to be defragged.
1553 */
1554 if (BTRFS_I(inode)->defrag_bytes &&
1555 test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1556 EXTENT_DEFRAG, 0, NULL))
1557 return 1;
1558
1559 return 0;
1560 }
1561
1562 /*
1563 * extent_io.c call back to do delayed allocation processing
1564 */
1565 static int run_delalloc_range(void *private_data, struct page *locked_page,
1566 u64 start, u64 end, int *page_started,
1567 unsigned long *nr_written)
1568 {
1569 struct inode *inode = private_data;
1570 int ret;
1571 int force_cow = need_force_cow(inode, start, end);
1572
1573 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
1574 ret = run_delalloc_nocow(inode, locked_page, start, end,
1575 page_started, 1, nr_written);
1576 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
1577 ret = run_delalloc_nocow(inode, locked_page, start, end,
1578 page_started, 0, nr_written);
1579 } else if (!inode_need_compress(inode)) {
1580 ret = cow_file_range(inode, locked_page, start, end, end,
1581 page_started, nr_written, 1, NULL);
1582 } else {
1583 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1584 &BTRFS_I(inode)->runtime_flags);
1585 ret = cow_file_range_async(inode, locked_page, start, end,
1586 page_started, nr_written);
1587 }
1588 if (ret)
1589 btrfs_cleanup_ordered_extents(inode, start, end - start + 1);
1590 return ret;
1591 }
1592
1593 static void btrfs_split_extent_hook(void *private_data,
1594 struct extent_state *orig, u64 split)
1595 {
1596 struct inode *inode = private_data;
1597 u64 size;
1598
1599 /* not delalloc, ignore it */
1600 if (!(orig->state & EXTENT_DELALLOC))
1601 return;
1602
1603 size = orig->end - orig->start + 1;
1604 if (size > BTRFS_MAX_EXTENT_SIZE) {
1605 u32 num_extents;
1606 u64 new_size;
1607
1608 /*
1609 * See the explanation in btrfs_merge_extent_hook, the same
1610 * applies here, just in reverse.
1611 */
1612 new_size = orig->end - split + 1;
1613 num_extents = count_max_extents(new_size);
1614 new_size = split - orig->start;
1615 num_extents += count_max_extents(new_size);
1616 if (count_max_extents(size) >= num_extents)
1617 return;
1618 }
1619
1620 spin_lock(&BTRFS_I(inode)->lock);
1621 BTRFS_I(inode)->outstanding_extents++;
1622 spin_unlock(&BTRFS_I(inode)->lock);
1623 }
1624
1625 /*
1626 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1627 * extents so we can keep track of new extents that are just merged onto old
1628 * extents, such as when we are doing sequential writes, so we can properly
1629 * account for the metadata space we'll need.
1630 */
1631 static void btrfs_merge_extent_hook(void *private_data,
1632 struct extent_state *new,
1633 struct extent_state *other)
1634 {
1635 struct inode *inode = private_data;
1636 u64 new_size, old_size;
1637 u32 num_extents;
1638
1639 /* not delalloc, ignore it */
1640 if (!(other->state & EXTENT_DELALLOC))
1641 return;
1642
1643 if (new->start > other->start)
1644 new_size = new->end - other->start + 1;
1645 else
1646 new_size = other->end - new->start + 1;
1647
1648 /* we're not bigger than the max, unreserve the space and go */
1649 if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
1650 spin_lock(&BTRFS_I(inode)->lock);
1651 BTRFS_I(inode)->outstanding_extents--;
1652 spin_unlock(&BTRFS_I(inode)->lock);
1653 return;
1654 }
1655
1656 /*
1657 * We have to add up either side to figure out how many extents were
1658 * accounted for before we merged into one big extent. If the number of
1659 * extents we accounted for is <= the amount we need for the new range
1660 * then we can return, otherwise drop. Think of it like this
1661 *
1662 * [ 4k][MAX_SIZE]
1663 *
1664 * So we've grown the extent by a MAX_SIZE extent, this would mean we
1665 * need 2 outstanding extents, on one side we have 1 and the other side
1666 * we have 1 so they are == and we can return. But in this case
1667 *
1668 * [MAX_SIZE+4k][MAX_SIZE+4k]
1669 *
1670 * Each range on their own accounts for 2 extents, but merged together
1671 * they are only 3 extents worth of accounting, so we need to drop in
1672 * this case.
1673 */
1674 old_size = other->end - other->start + 1;
1675 num_extents = count_max_extents(old_size);
1676 old_size = new->end - new->start + 1;
1677 num_extents += count_max_extents(old_size);
1678 if (count_max_extents(new_size) >= num_extents)
1679 return;
1680
1681 spin_lock(&BTRFS_I(inode)->lock);
1682 BTRFS_I(inode)->outstanding_extents--;
1683 spin_unlock(&BTRFS_I(inode)->lock);
1684 }
1685
1686 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1687 struct inode *inode)
1688 {
1689 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1690
1691 spin_lock(&root->delalloc_lock);
1692 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1693 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1694 &root->delalloc_inodes);
1695 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1696 &BTRFS_I(inode)->runtime_flags);
1697 root->nr_delalloc_inodes++;
1698 if (root->nr_delalloc_inodes == 1) {
1699 spin_lock(&fs_info->delalloc_root_lock);
1700 BUG_ON(!list_empty(&root->delalloc_root));
1701 list_add_tail(&root->delalloc_root,
1702 &fs_info->delalloc_roots);
1703 spin_unlock(&fs_info->delalloc_root_lock);
1704 }
1705 }
1706 spin_unlock(&root->delalloc_lock);
1707 }
1708
1709 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1710 struct btrfs_inode *inode)
1711 {
1712 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1713
1714 spin_lock(&root->delalloc_lock);
1715 if (!list_empty(&inode->delalloc_inodes)) {
1716 list_del_init(&inode->delalloc_inodes);
1717 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1718 &inode->runtime_flags);
1719 root->nr_delalloc_inodes--;
1720 if (!root->nr_delalloc_inodes) {
1721 spin_lock(&fs_info->delalloc_root_lock);
1722 BUG_ON(list_empty(&root->delalloc_root));
1723 list_del_init(&root->delalloc_root);
1724 spin_unlock(&fs_info->delalloc_root_lock);
1725 }
1726 }
1727 spin_unlock(&root->delalloc_lock);
1728 }
1729
1730 /*
1731 * extent_io.c set_bit_hook, used to track delayed allocation
1732 * bytes in this file, and to maintain the list of inodes that
1733 * have pending delalloc work to be done.
1734 */
1735 static void btrfs_set_bit_hook(void *private_data,
1736 struct extent_state *state, unsigned *bits)
1737 {
1738 struct inode *inode = private_data;
1739
1740 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1741
1742 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
1743 WARN_ON(1);
1744 /*
1745 * set_bit and clear bit hooks normally require _irqsave/restore
1746 * but in this case, we are only testing for the DELALLOC
1747 * bit, which is only set or cleared with irqs on
1748 */
1749 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1750 struct btrfs_root *root = BTRFS_I(inode)->root;
1751 u64 len = state->end + 1 - state->start;
1752 bool do_list = !btrfs_is_free_space_inode(BTRFS_I(inode));
1753
1754 if (*bits & EXTENT_FIRST_DELALLOC) {
1755 *bits &= ~EXTENT_FIRST_DELALLOC;
1756 } else {
1757 spin_lock(&BTRFS_I(inode)->lock);
1758 BTRFS_I(inode)->outstanding_extents++;
1759 spin_unlock(&BTRFS_I(inode)->lock);
1760 }
1761
1762 /* For sanity tests */
1763 if (btrfs_is_testing(fs_info))
1764 return;
1765
1766 percpu_counter_add_batch(&fs_info->delalloc_bytes, len,
1767 fs_info->delalloc_batch);
1768 spin_lock(&BTRFS_I(inode)->lock);
1769 BTRFS_I(inode)->delalloc_bytes += len;
1770 if (*bits & EXTENT_DEFRAG)
1771 BTRFS_I(inode)->defrag_bytes += len;
1772 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1773 &BTRFS_I(inode)->runtime_flags))
1774 btrfs_add_delalloc_inodes(root, inode);
1775 spin_unlock(&BTRFS_I(inode)->lock);
1776 }
1777
1778 if (!(state->state & EXTENT_DELALLOC_NEW) &&
1779 (*bits & EXTENT_DELALLOC_NEW)) {
1780 spin_lock(&BTRFS_I(inode)->lock);
1781 BTRFS_I(inode)->new_delalloc_bytes += state->end + 1 -
1782 state->start;
1783 spin_unlock(&BTRFS_I(inode)->lock);
1784 }
1785 }
1786
1787 /*
1788 * extent_io.c clear_bit_hook, see set_bit_hook for why
1789 */
1790 static void btrfs_clear_bit_hook(void *private_data,
1791 struct extent_state *state,
1792 unsigned *bits)
1793 {
1794 struct btrfs_inode *inode = BTRFS_I((struct inode *)private_data);
1795 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1796 u64 len = state->end + 1 - state->start;
1797 u32 num_extents = count_max_extents(len);
1798
1799 spin_lock(&inode->lock);
1800 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG))
1801 inode->defrag_bytes -= len;
1802 spin_unlock(&inode->lock);
1803
1804 /*
1805 * set_bit and clear bit hooks normally require _irqsave/restore
1806 * but in this case, we are only testing for the DELALLOC
1807 * bit, which is only set or cleared with irqs on
1808 */
1809 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1810 struct btrfs_root *root = inode->root;
1811 bool do_list = !btrfs_is_free_space_inode(inode);
1812
1813 if (*bits & EXTENT_FIRST_DELALLOC) {
1814 *bits &= ~EXTENT_FIRST_DELALLOC;
1815 } else if (!(*bits & EXTENT_CLEAR_META_RESV)) {
1816 spin_lock(&inode->lock);
1817 inode->outstanding_extents -= num_extents;
1818 spin_unlock(&inode->lock);
1819 }
1820
1821 /*
1822 * We don't reserve metadata space for space cache inodes so we
1823 * don't need to call dellalloc_release_metadata if there is an
1824 * error.
1825 */
1826 if (*bits & EXTENT_CLEAR_META_RESV &&
1827 root != fs_info->tree_root)
1828 btrfs_delalloc_release_metadata(inode, len);
1829
1830 /* For sanity tests. */
1831 if (btrfs_is_testing(fs_info))
1832 return;
1833
1834 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID &&
1835 do_list && !(state->state & EXTENT_NORESERVE) &&
1836 (*bits & EXTENT_CLEAR_DATA_RESV))
1837 btrfs_free_reserved_data_space_noquota(
1838 &inode->vfs_inode,
1839 state->start, len);
1840
1841 percpu_counter_add_batch(&fs_info->delalloc_bytes, -len,
1842 fs_info->delalloc_batch);
1843 spin_lock(&inode->lock);
1844 inode->delalloc_bytes -= len;
1845 if (do_list && inode->delalloc_bytes == 0 &&
1846 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1847 &inode->runtime_flags))
1848 btrfs_del_delalloc_inode(root, inode);
1849 spin_unlock(&inode->lock);
1850 }
1851
1852 if ((state->state & EXTENT_DELALLOC_NEW) &&
1853 (*bits & EXTENT_DELALLOC_NEW)) {
1854 spin_lock(&inode->lock);
1855 ASSERT(inode->new_delalloc_bytes >= len);
1856 inode->new_delalloc_bytes -= len;
1857 spin_unlock(&inode->lock);
1858 }
1859 }
1860
1861 /*
1862 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1863 * we don't create bios that span stripes or chunks
1864 *
1865 * return 1 if page cannot be merged to bio
1866 * return 0 if page can be merged to bio
1867 * return error otherwise
1868 */
1869 int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
1870 size_t size, struct bio *bio,
1871 unsigned long bio_flags)
1872 {
1873 struct inode *inode = page->mapping->host;
1874 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1875 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1876 u64 length = 0;
1877 u64 map_length;
1878 int ret;
1879
1880 if (bio_flags & EXTENT_BIO_COMPRESSED)
1881 return 0;
1882
1883 length = bio->bi_iter.bi_size;
1884 map_length = length;
1885 ret = btrfs_map_block(fs_info, btrfs_op(bio), logical, &map_length,
1886 NULL, 0);
1887 if (ret < 0)
1888 return ret;
1889 if (map_length < length + size)
1890 return 1;
1891 return 0;
1892 }
1893
1894 /*
1895 * in order to insert checksums into the metadata in large chunks,
1896 * we wait until bio submission time. All the pages in the bio are
1897 * checksummed and sums are attached onto the ordered extent record.
1898 *
1899 * At IO completion time the cums attached on the ordered extent record
1900 * are inserted into the btree
1901 */
1902 static blk_status_t __btrfs_submit_bio_start(void *private_data, struct bio *bio,
1903 int mirror_num, unsigned long bio_flags,
1904 u64 bio_offset)
1905 {
1906 struct inode *inode = private_data;
1907 blk_status_t ret = 0;
1908
1909 ret = btrfs_csum_one_bio(inode, bio, 0, 0);
1910 BUG_ON(ret); /* -ENOMEM */
1911 return 0;
1912 }
1913
1914 /*
1915 * in order to insert checksums into the metadata in large chunks,
1916 * we wait until bio submission time. All the pages in the bio are
1917 * checksummed and sums are attached onto the ordered extent record.
1918 *
1919 * At IO completion time the cums attached on the ordered extent record
1920 * are inserted into the btree
1921 */
1922 static blk_status_t __btrfs_submit_bio_done(void *private_data, struct bio *bio,
1923 int mirror_num, unsigned long bio_flags,
1924 u64 bio_offset)
1925 {
1926 struct inode *inode = private_data;
1927 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1928 blk_status_t ret;
1929
1930 ret = btrfs_map_bio(fs_info, bio, mirror_num, 1);
1931 if (ret) {
1932 bio->bi_status = ret;
1933 bio_endio(bio);
1934 }
1935 return ret;
1936 }
1937
1938 /*
1939 * extent_io.c submission hook. This does the right thing for csum calculation
1940 * on write, or reading the csums from the tree before a read
1941 */
1942 static blk_status_t btrfs_submit_bio_hook(void *private_data, struct bio *bio,
1943 int mirror_num, unsigned long bio_flags,
1944 u64 bio_offset)
1945 {
1946 struct inode *inode = private_data;
1947 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1948 struct btrfs_root *root = BTRFS_I(inode)->root;
1949 enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
1950 blk_status_t ret = 0;
1951 int skip_sum;
1952 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1953
1954 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1955
1956 if (btrfs_is_free_space_inode(BTRFS_I(inode)))
1957 metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
1958
1959 if (bio_op(bio) != REQ_OP_WRITE) {
1960 ret = btrfs_bio_wq_end_io(fs_info, bio, metadata);
1961 if (ret)
1962 goto out;
1963
1964 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1965 ret = btrfs_submit_compressed_read(inode, bio,
1966 mirror_num,
1967 bio_flags);
1968 goto out;
1969 } else if (!skip_sum) {
1970 ret = btrfs_lookup_bio_sums(inode, bio, NULL);
1971 if (ret)
1972 goto out;
1973 }
1974 goto mapit;
1975 } else if (async && !skip_sum) {
1976 /* csum items have already been cloned */
1977 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1978 goto mapit;
1979 /* we're doing a write, do the async checksumming */
1980 ret = btrfs_wq_submit_bio(fs_info, bio, mirror_num, bio_flags,
1981 bio_offset, inode,
1982 __btrfs_submit_bio_start,
1983 __btrfs_submit_bio_done);
1984 goto out;
1985 } else if (!skip_sum) {
1986 ret = btrfs_csum_one_bio(inode, bio, 0, 0);
1987 if (ret)
1988 goto out;
1989 }
1990
1991 mapit:
1992 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
1993
1994 out:
1995 if (ret) {
1996 bio->bi_status = ret;
1997 bio_endio(bio);
1998 }
1999 return ret;
2000 }
2001
2002 /*
2003 * given a list of ordered sums record them in the inode. This happens
2004 * at IO completion time based on sums calculated at bio submission time.
2005 */
2006 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
2007 struct inode *inode, struct list_head *list)
2008 {
2009 struct btrfs_ordered_sum *sum;
2010
2011 list_for_each_entry(sum, list, list) {
2012 trans->adding_csums = 1;
2013 btrfs_csum_file_blocks(trans,
2014 BTRFS_I(inode)->root->fs_info->csum_root, sum);
2015 trans->adding_csums = 0;
2016 }
2017 return 0;
2018 }
2019
2020 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
2021 struct extent_state **cached_state, int dedupe)
2022 {
2023 WARN_ON((end & (PAGE_SIZE - 1)) == 0);
2024 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
2025 cached_state);
2026 }
2027
2028 /* see btrfs_writepage_start_hook for details on why this is required */
2029 struct btrfs_writepage_fixup {
2030 struct page *page;
2031 struct btrfs_work work;
2032 };
2033
2034 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
2035 {
2036 struct btrfs_writepage_fixup *fixup;
2037 struct btrfs_ordered_extent *ordered;
2038 struct extent_state *cached_state = NULL;
2039 struct extent_changeset *data_reserved = NULL;
2040 struct page *page;
2041 struct inode *inode;
2042 u64 page_start;
2043 u64 page_end;
2044 int ret;
2045
2046 fixup = container_of(work, struct btrfs_writepage_fixup, work);
2047 page = fixup->page;
2048 again:
2049 lock_page(page);
2050 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
2051 ClearPageChecked(page);
2052 goto out_page;
2053 }
2054
2055 inode = page->mapping->host;
2056 page_start = page_offset(page);
2057 page_end = page_offset(page) + PAGE_SIZE - 1;
2058
2059 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
2060 &cached_state);
2061
2062 /* already ordered? We're done */
2063 if (PagePrivate2(page))
2064 goto out;
2065
2066 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
2067 PAGE_SIZE);
2068 if (ordered) {
2069 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
2070 page_end, &cached_state, GFP_NOFS);
2071 unlock_page(page);
2072 btrfs_start_ordered_extent(inode, ordered, 1);
2073 btrfs_put_ordered_extent(ordered);
2074 goto again;
2075 }
2076
2077 ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
2078 PAGE_SIZE);
2079 if (ret) {
2080 mapping_set_error(page->mapping, ret);
2081 end_extent_writepage(page, ret, page_start, page_end);
2082 ClearPageChecked(page);
2083 goto out;
2084 }
2085
2086 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state,
2087 0);
2088 ClearPageChecked(page);
2089 set_page_dirty(page);
2090 out:
2091 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
2092 &cached_state, GFP_NOFS);
2093 out_page:
2094 unlock_page(page);
2095 put_page(page);
2096 kfree(fixup);
2097 extent_changeset_free(data_reserved);
2098 }
2099
2100 /*
2101 * There are a few paths in the higher layers of the kernel that directly
2102 * set the page dirty bit without asking the filesystem if it is a
2103 * good idea. This causes problems because we want to make sure COW
2104 * properly happens and the data=ordered rules are followed.
2105 *
2106 * In our case any range that doesn't have the ORDERED bit set
2107 * hasn't been properly setup for IO. We kick off an async process
2108 * to fix it up. The async helper will wait for ordered extents, set
2109 * the delalloc bit and make it safe to write the page.
2110 */
2111 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
2112 {
2113 struct inode *inode = page->mapping->host;
2114 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2115 struct btrfs_writepage_fixup *fixup;
2116
2117 /* this page is properly in the ordered list */
2118 if (TestClearPagePrivate2(page))
2119 return 0;
2120
2121 if (PageChecked(page))
2122 return -EAGAIN;
2123
2124 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
2125 if (!fixup)
2126 return -EAGAIN;
2127
2128 SetPageChecked(page);
2129 get_page(page);
2130 btrfs_init_work(&fixup->work, btrfs_fixup_helper,
2131 btrfs_writepage_fixup_worker, NULL, NULL);
2132 fixup->page = page;
2133 btrfs_queue_work(fs_info->fixup_workers, &fixup->work);
2134 return -EBUSY;
2135 }
2136
2137 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
2138 struct inode *inode, u64 file_pos,
2139 u64 disk_bytenr, u64 disk_num_bytes,
2140 u64 num_bytes, u64 ram_bytes,
2141 u8 compression, u8 encryption,
2142 u16 other_encoding, int extent_type)
2143 {
2144 struct btrfs_root *root = BTRFS_I(inode)->root;
2145 struct btrfs_file_extent_item *fi;
2146 struct btrfs_path *path;
2147 struct extent_buffer *leaf;
2148 struct btrfs_key ins;
2149 u64 qg_released;
2150 int extent_inserted = 0;
2151 int ret;
2152
2153 path = btrfs_alloc_path();
2154 if (!path)
2155 return -ENOMEM;
2156
2157 /*
2158 * we may be replacing one extent in the tree with another.
2159 * The new extent is pinned in the extent map, and we don't want
2160 * to drop it from the cache until it is completely in the btree.
2161 *
2162 * So, tell btrfs_drop_extents to leave this extent in the cache.
2163 * the caller is expected to unpin it and allow it to be merged
2164 * with the others.
2165 */
2166 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
2167 file_pos + num_bytes, NULL, 0,
2168 1, sizeof(*fi), &extent_inserted);
2169 if (ret)
2170 goto out;
2171
2172 if (!extent_inserted) {
2173 ins.objectid = btrfs_ino(BTRFS_I(inode));
2174 ins.offset = file_pos;
2175 ins.type = BTRFS_EXTENT_DATA_KEY;
2176
2177 path->leave_spinning = 1;
2178 ret = btrfs_insert_empty_item(trans, root, path, &ins,
2179 sizeof(*fi));
2180 if (ret)
2181 goto out;
2182 }
2183 leaf = path->nodes[0];
2184 fi = btrfs_item_ptr(leaf, path->slots[0],
2185 struct btrfs_file_extent_item);
2186 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2187 btrfs_set_file_extent_type(leaf, fi, extent_type);
2188 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
2189 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
2190 btrfs_set_file_extent_offset(leaf, fi, 0);
2191 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2192 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
2193 btrfs_set_file_extent_compression(leaf, fi, compression);
2194 btrfs_set_file_extent_encryption(leaf, fi, encryption);
2195 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
2196
2197 btrfs_mark_buffer_dirty(leaf);
2198 btrfs_release_path(path);
2199
2200 inode_add_bytes(inode, num_bytes);
2201
2202 ins.objectid = disk_bytenr;
2203 ins.offset = disk_num_bytes;
2204 ins.type = BTRFS_EXTENT_ITEM_KEY;
2205
2206 /*
2207 * Release the reserved range from inode dirty range map, as it is
2208 * already moved into delayed_ref_head
2209 */
2210 ret = btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
2211 if (ret < 0)
2212 goto out;
2213 qg_released = ret;
2214 ret = btrfs_alloc_reserved_file_extent(trans, root->root_key.objectid,
2215 btrfs_ino(BTRFS_I(inode)), file_pos, qg_released, &ins);
2216 out:
2217 btrfs_free_path(path);
2218
2219 return ret;
2220 }
2221
2222 /* snapshot-aware defrag */
2223 struct sa_defrag_extent_backref {
2224 struct rb_node node;
2225 struct old_sa_defrag_extent *old;
2226 u64 root_id;
2227 u64 inum;
2228 u64 file_pos;
2229 u64 extent_offset;
2230 u64 num_bytes;
2231 u64 generation;
2232 };
2233
2234 struct old_sa_defrag_extent {
2235 struct list_head list;
2236 struct new_sa_defrag_extent *new;
2237
2238 u64 extent_offset;
2239 u64 bytenr;
2240 u64 offset;
2241 u64 len;
2242 int count;
2243 };
2244
2245 struct new_sa_defrag_extent {
2246 struct rb_root root;
2247 struct list_head head;
2248 struct btrfs_path *path;
2249 struct inode *inode;
2250 u64 file_pos;
2251 u64 len;
2252 u64 bytenr;
2253 u64 disk_len;
2254 u8 compress_type;
2255 };
2256
2257 static int backref_comp(struct sa_defrag_extent_backref *b1,
2258 struct sa_defrag_extent_backref *b2)
2259 {
2260 if (b1->root_id < b2->root_id)
2261 return -1;
2262 else if (b1->root_id > b2->root_id)
2263 return 1;
2264
2265 if (b1->inum < b2->inum)
2266 return -1;
2267 else if (b1->inum > b2->inum)
2268 return 1;
2269
2270 if (b1->file_pos < b2->file_pos)
2271 return -1;
2272 else if (b1->file_pos > b2->file_pos)
2273 return 1;
2274
2275 /*
2276 * [------------------------------] ===> (a range of space)
2277 * |<--->| |<---->| =============> (fs/file tree A)
2278 * |<---------------------------->| ===> (fs/file tree B)
2279 *
2280 * A range of space can refer to two file extents in one tree while
2281 * refer to only one file extent in another tree.
2282 *
2283 * So we may process a disk offset more than one time(two extents in A)
2284 * and locate at the same extent(one extent in B), then insert two same
2285 * backrefs(both refer to the extent in B).
2286 */
2287 return 0;
2288 }
2289
2290 static void backref_insert(struct rb_root *root,
2291 struct sa_defrag_extent_backref *backref)
2292 {
2293 struct rb_node **p = &root->rb_node;
2294 struct rb_node *parent = NULL;
2295 struct sa_defrag_extent_backref *entry;
2296 int ret;
2297
2298 while (*p) {
2299 parent = *p;
2300 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2301
2302 ret = backref_comp(backref, entry);
2303 if (ret < 0)
2304 p = &(*p)->rb_left;
2305 else
2306 p = &(*p)->rb_right;
2307 }
2308
2309 rb_link_node(&backref->node, parent, p);
2310 rb_insert_color(&backref->node, root);
2311 }
2312
2313 /*
2314 * Note the backref might has changed, and in this case we just return 0.
2315 */
2316 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2317 void *ctx)
2318 {
2319 struct btrfs_file_extent_item *extent;
2320 struct old_sa_defrag_extent *old = ctx;
2321 struct new_sa_defrag_extent *new = old->new;
2322 struct btrfs_path *path = new->path;
2323 struct btrfs_key key;
2324 struct btrfs_root *root;
2325 struct sa_defrag_extent_backref *backref;
2326 struct extent_buffer *leaf;
2327 struct inode *inode = new->inode;
2328 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2329 int slot;
2330 int ret;
2331 u64 extent_offset;
2332 u64 num_bytes;
2333
2334 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2335 inum == btrfs_ino(BTRFS_I(inode)))
2336 return 0;
2337
2338 key.objectid = root_id;
2339 key.type = BTRFS_ROOT_ITEM_KEY;
2340 key.offset = (u64)-1;
2341
2342 root = btrfs_read_fs_root_no_name(fs_info, &key);
2343 if (IS_ERR(root)) {
2344 if (PTR_ERR(root) == -ENOENT)
2345 return 0;
2346 WARN_ON(1);
2347 btrfs_debug(fs_info, "inum=%llu, offset=%llu, root_id=%llu",
2348 inum, offset, root_id);
2349 return PTR_ERR(root);
2350 }
2351
2352 key.objectid = inum;
2353 key.type = BTRFS_EXTENT_DATA_KEY;
2354 if (offset > (u64)-1 << 32)
2355 key.offset = 0;
2356 else
2357 key.offset = offset;
2358
2359 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2360 if (WARN_ON(ret < 0))
2361 return ret;
2362 ret = 0;
2363
2364 while (1) {
2365 cond_resched();
2366
2367 leaf = path->nodes[0];
2368 slot = path->slots[0];
2369
2370 if (slot >= btrfs_header_nritems(leaf)) {
2371 ret = btrfs_next_leaf(root, path);
2372 if (ret < 0) {
2373 goto out;
2374 } else if (ret > 0) {
2375 ret = 0;
2376 goto out;
2377 }
2378 continue;
2379 }
2380
2381 path->slots[0]++;
2382
2383 btrfs_item_key_to_cpu(leaf, &key, slot);
2384
2385 if (key.objectid > inum)
2386 goto out;
2387
2388 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2389 continue;
2390
2391 extent = btrfs_item_ptr(leaf, slot,
2392 struct btrfs_file_extent_item);
2393
2394 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2395 continue;
2396
2397 /*
2398 * 'offset' refers to the exact key.offset,
2399 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2400 * (key.offset - extent_offset).
2401 */
2402 if (key.offset != offset)
2403 continue;
2404
2405 extent_offset = btrfs_file_extent_offset(leaf, extent);
2406 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2407
2408 if (extent_offset >= old->extent_offset + old->offset +
2409 old->len || extent_offset + num_bytes <=
2410 old->extent_offset + old->offset)
2411 continue;
2412 break;
2413 }
2414
2415 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2416 if (!backref) {
2417 ret = -ENOENT;
2418 goto out;
2419 }
2420
2421 backref->root_id = root_id;
2422 backref->inum = inum;
2423 backref->file_pos = offset;
2424 backref->num_bytes = num_bytes;
2425 backref->extent_offset = extent_offset;
2426 backref->generation = btrfs_file_extent_generation(leaf, extent);
2427 backref->old = old;
2428 backref_insert(&new->root, backref);
2429 old->count++;
2430 out:
2431 btrfs_release_path(path);
2432 WARN_ON(ret);
2433 return ret;
2434 }
2435
2436 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2437 struct new_sa_defrag_extent *new)
2438 {
2439 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2440 struct old_sa_defrag_extent *old, *tmp;
2441 int ret;
2442
2443 new->path = path;
2444
2445 list_for_each_entry_safe(old, tmp, &new->head, list) {
2446 ret = iterate_inodes_from_logical(old->bytenr +
2447 old->extent_offset, fs_info,
2448 path, record_one_backref,
2449 old);
2450 if (ret < 0 && ret != -ENOENT)
2451 return false;
2452
2453 /* no backref to be processed for this extent */
2454 if (!old->count) {
2455 list_del(&old->list);
2456 kfree(old);
2457 }
2458 }
2459
2460 if (list_empty(&new->head))
2461 return false;
2462
2463 return true;
2464 }
2465
2466 static int relink_is_mergable(struct extent_buffer *leaf,
2467 struct btrfs_file_extent_item *fi,
2468 struct new_sa_defrag_extent *new)
2469 {
2470 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2471 return 0;
2472
2473 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2474 return 0;
2475
2476 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2477 return 0;
2478
2479 if (btrfs_file_extent_encryption(leaf, fi) ||
2480 btrfs_file_extent_other_encoding(leaf, fi))
2481 return 0;
2482
2483 return 1;
2484 }
2485
2486 /*
2487 * Note the backref might has changed, and in this case we just return 0.
2488 */
2489 static noinline int relink_extent_backref(struct btrfs_path *path,
2490 struct sa_defrag_extent_backref *prev,
2491 struct sa_defrag_extent_backref *backref)
2492 {
2493 struct btrfs_file_extent_item *extent;
2494 struct btrfs_file_extent_item *item;
2495 struct btrfs_ordered_extent *ordered;
2496 struct btrfs_trans_handle *trans;
2497 struct btrfs_root *root;
2498 struct btrfs_key key;
2499 struct extent_buffer *leaf;
2500 struct old_sa_defrag_extent *old = backref->old;
2501 struct new_sa_defrag_extent *new = old->new;
2502 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2503 struct inode *inode;
2504 struct extent_state *cached = NULL;
2505 int ret = 0;
2506 u64 start;
2507 u64 len;
2508 u64 lock_start;
2509 u64 lock_end;
2510 bool merge = false;
2511 int index;
2512
2513 if (prev && prev->root_id == backref->root_id &&
2514 prev->inum == backref->inum &&
2515 prev->file_pos + prev->num_bytes == backref->file_pos)
2516 merge = true;
2517
2518 /* step 1: get root */
2519 key.objectid = backref->root_id;
2520 key.type = BTRFS_ROOT_ITEM_KEY;
2521 key.offset = (u64)-1;
2522
2523 index = srcu_read_lock(&fs_info->subvol_srcu);
2524
2525 root = btrfs_read_fs_root_no_name(fs_info, &key);
2526 if (IS_ERR(root)) {
2527 srcu_read_unlock(&fs_info->subvol_srcu, index);
2528 if (PTR_ERR(root) == -ENOENT)
2529 return 0;
2530 return PTR_ERR(root);
2531 }
2532
2533 if (btrfs_root_readonly(root)) {
2534 srcu_read_unlock(&fs_info->subvol_srcu, index);
2535 return 0;
2536 }
2537
2538 /* step 2: get inode */
2539 key.objectid = backref->inum;
2540 key.type = BTRFS_INODE_ITEM_KEY;
2541 key.offset = 0;
2542
2543 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2544 if (IS_ERR(inode)) {
2545 srcu_read_unlock(&fs_info->subvol_srcu, index);
2546 return 0;
2547 }
2548
2549 srcu_read_unlock(&fs_info->subvol_srcu, index);
2550
2551 /* step 3: relink backref */
2552 lock_start = backref->file_pos;
2553 lock_end = backref->file_pos + backref->num_bytes - 1;
2554 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2555 &cached);
2556
2557 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2558 if (ordered) {
2559 btrfs_put_ordered_extent(ordered);
2560 goto out_unlock;
2561 }
2562
2563 trans = btrfs_join_transaction(root);
2564 if (IS_ERR(trans)) {
2565 ret = PTR_ERR(trans);
2566 goto out_unlock;
2567 }
2568
2569 key.objectid = backref->inum;
2570 key.type = BTRFS_EXTENT_DATA_KEY;
2571 key.offset = backref->file_pos;
2572
2573 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2574 if (ret < 0) {
2575 goto out_free_path;
2576 } else if (ret > 0) {
2577 ret = 0;
2578 goto out_free_path;
2579 }
2580
2581 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2582 struct btrfs_file_extent_item);
2583
2584 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2585 backref->generation)
2586 goto out_free_path;
2587
2588 btrfs_release_path(path);
2589
2590 start = backref->file_pos;
2591 if (backref->extent_offset < old->extent_offset + old->offset)
2592 start += old->extent_offset + old->offset -
2593 backref->extent_offset;
2594
2595 len = min(backref->extent_offset + backref->num_bytes,
2596 old->extent_offset + old->offset + old->len);
2597 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2598
2599 ret = btrfs_drop_extents(trans, root, inode, start,
2600 start + len, 1);
2601 if (ret)
2602 goto out_free_path;
2603 again:
2604 key.objectid = btrfs_ino(BTRFS_I(inode));
2605 key.type = BTRFS_EXTENT_DATA_KEY;
2606 key.offset = start;
2607
2608 path->leave_spinning = 1;
2609 if (merge) {
2610 struct btrfs_file_extent_item *fi;
2611 u64 extent_len;
2612 struct btrfs_key found_key;
2613
2614 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2615 if (ret < 0)
2616 goto out_free_path;
2617
2618 path->slots[0]--;
2619 leaf = path->nodes[0];
2620 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2621
2622 fi = btrfs_item_ptr(leaf, path->slots[0],
2623 struct btrfs_file_extent_item);
2624 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2625
2626 if (extent_len + found_key.offset == start &&
2627 relink_is_mergable(leaf, fi, new)) {
2628 btrfs_set_file_extent_num_bytes(leaf, fi,
2629 extent_len + len);
2630 btrfs_mark_buffer_dirty(leaf);
2631 inode_add_bytes(inode, len);
2632
2633 ret = 1;
2634 goto out_free_path;
2635 } else {
2636 merge = false;
2637 btrfs_release_path(path);
2638 goto again;
2639 }
2640 }
2641
2642 ret = btrfs_insert_empty_item(trans, root, path, &key,
2643 sizeof(*extent));
2644 if (ret) {
2645 btrfs_abort_transaction(trans, ret);
2646 goto out_free_path;
2647 }
2648
2649 leaf = path->nodes[0];
2650 item = btrfs_item_ptr(leaf, path->slots[0],
2651 struct btrfs_file_extent_item);
2652 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2653 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2654 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2655 btrfs_set_file_extent_num_bytes(leaf, item, len);
2656 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2657 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2658 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2659 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2660 btrfs_set_file_extent_encryption(leaf, item, 0);
2661 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2662
2663 btrfs_mark_buffer_dirty(leaf);
2664 inode_add_bytes(inode, len);
2665 btrfs_release_path(path);
2666
2667 ret = btrfs_inc_extent_ref(trans, fs_info, new->bytenr,
2668 new->disk_len, 0,
2669 backref->root_id, backref->inum,
2670 new->file_pos); /* start - extent_offset */
2671 if (ret) {
2672 btrfs_abort_transaction(trans, ret);
2673 goto out_free_path;
2674 }
2675
2676 ret = 1;
2677 out_free_path:
2678 btrfs_release_path(path);
2679 path->leave_spinning = 0;
2680 btrfs_end_transaction(trans);
2681 out_unlock:
2682 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2683 &cached, GFP_NOFS);
2684 iput(inode);
2685 return ret;
2686 }
2687
2688 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2689 {
2690 struct old_sa_defrag_extent *old, *tmp;
2691
2692 if (!new)
2693 return;
2694
2695 list_for_each_entry_safe(old, tmp, &new->head, list) {
2696 kfree(old);
2697 }
2698 kfree(new);
2699 }
2700
2701 static void relink_file_extents(struct new_sa_defrag_extent *new)
2702 {
2703 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2704 struct btrfs_path *path;
2705 struct sa_defrag_extent_backref *backref;
2706 struct sa_defrag_extent_backref *prev = NULL;
2707 struct inode *inode;
2708 struct btrfs_root *root;
2709 struct rb_node *node;
2710 int ret;
2711
2712 inode = new->inode;
2713 root = BTRFS_I(inode)->root;
2714
2715 path = btrfs_alloc_path();
2716 if (!path)
2717 return;
2718
2719 if (!record_extent_backrefs(path, new)) {
2720 btrfs_free_path(path);
2721 goto out;
2722 }
2723 btrfs_release_path(path);
2724
2725 while (1) {
2726 node = rb_first(&new->root);
2727 if (!node)
2728 break;
2729 rb_erase(node, &new->root);
2730
2731 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2732
2733 ret = relink_extent_backref(path, prev, backref);
2734 WARN_ON(ret < 0);
2735
2736 kfree(prev);
2737
2738 if (ret == 1)
2739 prev = backref;
2740 else
2741 prev = NULL;
2742 cond_resched();
2743 }
2744 kfree(prev);
2745
2746 btrfs_free_path(path);
2747 out:
2748 free_sa_defrag_extent(new);
2749
2750 atomic_dec(&fs_info->defrag_running);
2751 wake_up(&fs_info->transaction_wait);
2752 }
2753
2754 static struct new_sa_defrag_extent *
2755 record_old_file_extents(struct inode *inode,
2756 struct btrfs_ordered_extent *ordered)
2757 {
2758 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2759 struct btrfs_root *root = BTRFS_I(inode)->root;
2760 struct btrfs_path *path;
2761 struct btrfs_key key;
2762 struct old_sa_defrag_extent *old;
2763 struct new_sa_defrag_extent *new;
2764 int ret;
2765
2766 new = kmalloc(sizeof(*new), GFP_NOFS);
2767 if (!new)
2768 return NULL;
2769
2770 new->inode = inode;
2771 new->file_pos = ordered->file_offset;
2772 new->len = ordered->len;
2773 new->bytenr = ordered->start;
2774 new->disk_len = ordered->disk_len;
2775 new->compress_type = ordered->compress_type;
2776 new->root = RB_ROOT;
2777 INIT_LIST_HEAD(&new->head);
2778
2779 path = btrfs_alloc_path();
2780 if (!path)
2781 goto out_kfree;
2782
2783 key.objectid = btrfs_ino(BTRFS_I(inode));
2784 key.type = BTRFS_EXTENT_DATA_KEY;
2785 key.offset = new->file_pos;
2786
2787 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2788 if (ret < 0)
2789 goto out_free_path;
2790 if (ret > 0 && path->slots[0] > 0)
2791 path->slots[0]--;
2792
2793 /* find out all the old extents for the file range */
2794 while (1) {
2795 struct btrfs_file_extent_item *extent;
2796 struct extent_buffer *l;
2797 int slot;
2798 u64 num_bytes;
2799 u64 offset;
2800 u64 end;
2801 u64 disk_bytenr;
2802 u64 extent_offset;
2803
2804 l = path->nodes[0];
2805 slot = path->slots[0];
2806
2807 if (slot >= btrfs_header_nritems(l)) {
2808 ret = btrfs_next_leaf(root, path);
2809 if (ret < 0)
2810 goto out_free_path;
2811 else if (ret > 0)
2812 break;
2813 continue;
2814 }
2815
2816 btrfs_item_key_to_cpu(l, &key, slot);
2817
2818 if (key.objectid != btrfs_ino(BTRFS_I(inode)))
2819 break;
2820 if (key.type != BTRFS_EXTENT_DATA_KEY)
2821 break;
2822 if (key.offset >= new->file_pos + new->len)
2823 break;
2824
2825 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2826
2827 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2828 if (key.offset + num_bytes < new->file_pos)
2829 goto next;
2830
2831 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2832 if (!disk_bytenr)
2833 goto next;
2834
2835 extent_offset = btrfs_file_extent_offset(l, extent);
2836
2837 old = kmalloc(sizeof(*old), GFP_NOFS);
2838 if (!old)
2839 goto out_free_path;
2840
2841 offset = max(new->file_pos, key.offset);
2842 end = min(new->file_pos + new->len, key.offset + num_bytes);
2843
2844 old->bytenr = disk_bytenr;
2845 old->extent_offset = extent_offset;
2846 old->offset = offset - key.offset;
2847 old->len = end - offset;
2848 old->new = new;
2849 old->count = 0;
2850 list_add_tail(&old->list, &new->head);
2851 next:
2852 path->slots[0]++;
2853 cond_resched();
2854 }
2855
2856 btrfs_free_path(path);
2857 atomic_inc(&fs_info->defrag_running);
2858
2859 return new;
2860
2861 out_free_path:
2862 btrfs_free_path(path);
2863 out_kfree:
2864 free_sa_defrag_extent(new);
2865 return NULL;
2866 }
2867
2868 static void btrfs_release_delalloc_bytes(struct btrfs_fs_info *fs_info,
2869 u64 start, u64 len)
2870 {
2871 struct btrfs_block_group_cache *cache;
2872
2873 cache = btrfs_lookup_block_group(fs_info, start);
2874 ASSERT(cache);
2875
2876 spin_lock(&cache->lock);
2877 cache->delalloc_bytes -= len;
2878 spin_unlock(&cache->lock);
2879
2880 btrfs_put_block_group(cache);
2881 }
2882
2883 /* as ordered data IO finishes, this gets called so we can finish
2884 * an ordered extent if the range of bytes in the file it covers are
2885 * fully written.
2886 */
2887 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2888 {
2889 struct inode *inode = ordered_extent->inode;
2890 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2891 struct btrfs_root *root = BTRFS_I(inode)->root;
2892 struct btrfs_trans_handle *trans = NULL;
2893 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2894 struct extent_state *cached_state = NULL;
2895 struct new_sa_defrag_extent *new = NULL;
2896 int compress_type = 0;
2897 int ret = 0;
2898 u64 logical_len = ordered_extent->len;
2899 bool nolock;
2900 bool truncated = false;
2901 bool range_locked = false;
2902 bool clear_new_delalloc_bytes = false;
2903
2904 if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2905 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags) &&
2906 !test_bit(BTRFS_ORDERED_DIRECT, &ordered_extent->flags))
2907 clear_new_delalloc_bytes = true;
2908
2909 nolock = btrfs_is_free_space_inode(BTRFS_I(inode));
2910
2911 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2912 ret = -EIO;
2913 goto out;
2914 }
2915
2916 btrfs_free_io_failure_record(BTRFS_I(inode),
2917 ordered_extent->file_offset,
2918 ordered_extent->file_offset +
2919 ordered_extent->len - 1);
2920
2921 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2922 truncated = true;
2923 logical_len = ordered_extent->truncated_len;
2924 /* Truncated the entire extent, don't bother adding */
2925 if (!logical_len)
2926 goto out;
2927 }
2928
2929 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2930 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2931
2932 /*
2933 * For mwrite(mmap + memset to write) case, we still reserve
2934 * space for NOCOW range.
2935 * As NOCOW won't cause a new delayed ref, just free the space
2936 */
2937 btrfs_qgroup_free_data(inode, NULL, ordered_extent->file_offset,
2938 ordered_extent->len);
2939 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2940 if (nolock)
2941 trans = btrfs_join_transaction_nolock(root);
2942 else
2943 trans = btrfs_join_transaction(root);
2944 if (IS_ERR(trans)) {
2945 ret = PTR_ERR(trans);
2946 trans = NULL;
2947 goto out;
2948 }
2949 trans->block_rsv = &fs_info->delalloc_block_rsv;
2950 ret = btrfs_update_inode_fallback(trans, root, inode);
2951 if (ret) /* -ENOMEM or corruption */
2952 btrfs_abort_transaction(trans, ret);
2953 goto out;
2954 }
2955
2956 range_locked = true;
2957 lock_extent_bits(io_tree, ordered_extent->file_offset,
2958 ordered_extent->file_offset + ordered_extent->len - 1,
2959 &cached_state);
2960
2961 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2962 ordered_extent->file_offset + ordered_extent->len - 1,
2963 EXTENT_DEFRAG, 0, cached_state);
2964 if (ret) {
2965 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2966 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
2967 /* the inode is shared */
2968 new = record_old_file_extents(inode, ordered_extent);
2969
2970 clear_extent_bit(io_tree, ordered_extent->file_offset,
2971 ordered_extent->file_offset + ordered_extent->len - 1,
2972 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2973 }
2974
2975 if (nolock)
2976 trans = btrfs_join_transaction_nolock(root);
2977 else
2978 trans = btrfs_join_transaction(root);
2979 if (IS_ERR(trans)) {
2980 ret = PTR_ERR(trans);
2981 trans = NULL;
2982 goto out;
2983 }
2984
2985 trans->block_rsv = &fs_info->delalloc_block_rsv;
2986
2987 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2988 compress_type = ordered_extent->compress_type;
2989 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2990 BUG_ON(compress_type);
2991 ret = btrfs_mark_extent_written(trans, BTRFS_I(inode),
2992 ordered_extent->file_offset,
2993 ordered_extent->file_offset +
2994 logical_len);
2995 } else {
2996 BUG_ON(root == fs_info->tree_root);
2997 ret = insert_reserved_file_extent(trans, inode,
2998 ordered_extent->file_offset,
2999 ordered_extent->start,
3000 ordered_extent->disk_len,
3001 logical_len, logical_len,
3002 compress_type, 0, 0,
3003 BTRFS_FILE_EXTENT_REG);
3004 if (!ret)
3005 btrfs_release_delalloc_bytes(fs_info,
3006 ordered_extent->start,
3007 ordered_extent->disk_len);
3008 }
3009 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
3010 ordered_extent->file_offset, ordered_extent->len,
3011 trans->transid);
3012 if (ret < 0) {
3013 btrfs_abort_transaction(trans, ret);
3014 goto out;
3015 }
3016
3017 add_pending_csums(trans, inode, &ordered_extent->list);
3018
3019 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
3020 ret = btrfs_update_inode_fallback(trans, root, inode);
3021 if (ret) { /* -ENOMEM or corruption */
3022 btrfs_abort_transaction(trans, ret);
3023 goto out;
3024 }
3025 ret = 0;
3026 out:
3027 if (range_locked || clear_new_delalloc_bytes) {
3028 unsigned int clear_bits = 0;
3029
3030 if (range_locked)
3031 clear_bits |= EXTENT_LOCKED;
3032 if (clear_new_delalloc_bytes)
3033 clear_bits |= EXTENT_DELALLOC_NEW;
3034 clear_extent_bit(&BTRFS_I(inode)->io_tree,
3035 ordered_extent->file_offset,
3036 ordered_extent->file_offset +
3037 ordered_extent->len - 1,
3038 clear_bits,
3039 (clear_bits & EXTENT_LOCKED) ? 1 : 0,
3040 0, &cached_state, GFP_NOFS);
3041 }
3042
3043 if (root != fs_info->tree_root)
3044 btrfs_delalloc_release_metadata(BTRFS_I(inode),
3045 ordered_extent->len);
3046 if (trans)
3047 btrfs_end_transaction(trans);
3048
3049 if (ret || truncated) {
3050 u64 start, end;
3051
3052 if (truncated)
3053 start = ordered_extent->file_offset + logical_len;
3054 else
3055 start = ordered_extent->file_offset;
3056 end = ordered_extent->file_offset + ordered_extent->len - 1;
3057 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
3058
3059 /* Drop the cache for the part of the extent we didn't write. */
3060 btrfs_drop_extent_cache(BTRFS_I(inode), start, end, 0);
3061
3062 /*
3063 * If the ordered extent had an IOERR or something else went
3064 * wrong we need to return the space for this ordered extent
3065 * back to the allocator. We only free the extent in the
3066 * truncated case if we didn't write out the extent at all.
3067 */
3068 if ((ret || !logical_len) &&
3069 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
3070 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
3071 btrfs_free_reserved_extent(fs_info,
3072 ordered_extent->start,
3073 ordered_extent->disk_len, 1);
3074 }
3075
3076
3077 /*
3078 * This needs to be done to make sure anybody waiting knows we are done
3079 * updating everything for this ordered extent.
3080 */
3081 btrfs_remove_ordered_extent(inode, ordered_extent);
3082
3083 /* for snapshot-aware defrag */
3084 if (new) {
3085 if (ret) {
3086 free_sa_defrag_extent(new);
3087 atomic_dec(&fs_info->defrag_running);
3088 } else {
3089 relink_file_extents(new);
3090 }
3091 }
3092
3093 /* once for us */
3094 btrfs_put_ordered_extent(ordered_extent);
3095 /* once for the tree */
3096 btrfs_put_ordered_extent(ordered_extent);
3097
3098 return ret;
3099 }
3100
3101 static void finish_ordered_fn(struct btrfs_work *work)
3102 {
3103 struct btrfs_ordered_extent *ordered_extent;
3104 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
3105 btrfs_finish_ordered_io(ordered_extent);
3106 }
3107
3108 static void btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
3109 struct extent_state *state, int uptodate)
3110 {
3111 struct inode *inode = page->mapping->host;
3112 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3113 struct btrfs_ordered_extent *ordered_extent = NULL;
3114 struct btrfs_workqueue *wq;
3115 btrfs_work_func_t func;
3116
3117 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
3118
3119 ClearPagePrivate2(page);
3120 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
3121 end - start + 1, uptodate))
3122 return;
3123
3124 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
3125 wq = fs_info->endio_freespace_worker;
3126 func = btrfs_freespace_write_helper;
3127 } else {
3128 wq = fs_info->endio_write_workers;
3129 func = btrfs_endio_write_helper;
3130 }
3131
3132 btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
3133 NULL);
3134 btrfs_queue_work(wq, &ordered_extent->work);
3135 }
3136
3137 static int __readpage_endio_check(struct inode *inode,
3138 struct btrfs_io_bio *io_bio,
3139 int icsum, struct page *page,
3140 int pgoff, u64 start, size_t len)
3141 {
3142 char *kaddr;
3143 u32 csum_expected;
3144 u32 csum = ~(u32)0;
3145
3146 csum_expected = *(((u32 *)io_bio->csum) + icsum);
3147
3148 kaddr = kmap_atomic(page);
3149 csum = btrfs_csum_data(kaddr + pgoff, csum, len);
3150 btrfs_csum_final(csum, (u8 *)&csum);
3151 if (csum != csum_expected)
3152 goto zeroit;
3153
3154 kunmap_atomic(kaddr);
3155 return 0;
3156 zeroit:
3157 btrfs_print_data_csum_error(BTRFS_I(inode), start, csum, csum_expected,
3158 io_bio->mirror_num);
3159 memset(kaddr + pgoff, 1, len);
3160 flush_dcache_page(page);
3161 kunmap_atomic(kaddr);
3162 if (csum_expected == 0)
3163 return 0;
3164 return -EIO;
3165 }
3166
3167 /*
3168 * when reads are done, we need to check csums to verify the data is correct
3169 * if there's a match, we allow the bio to finish. If not, the code in
3170 * extent_io.c will try to find good copies for us.
3171 */
3172 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
3173 u64 phy_offset, struct page *page,
3174 u64 start, u64 end, int mirror)
3175 {
3176 size_t offset = start - page_offset(page);
3177 struct inode *inode = page->mapping->host;
3178 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3179 struct btrfs_root *root = BTRFS_I(inode)->root;
3180
3181 if (PageChecked(page)) {
3182 ClearPageChecked(page);
3183 return 0;
3184 }
3185
3186 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3187 return 0;
3188
3189 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
3190 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
3191 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM);
3192 return 0;
3193 }
3194
3195 phy_offset >>= inode->i_sb->s_blocksize_bits;
3196 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3197 start, (size_t)(end - start + 1));
3198 }
3199
3200 void btrfs_add_delayed_iput(struct inode *inode)
3201 {
3202 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3203 struct btrfs_inode *binode = BTRFS_I(inode);
3204
3205 if (atomic_add_unless(&inode->i_count, -1, 1))
3206 return;
3207
3208 spin_lock(&fs_info->delayed_iput_lock);
3209 if (binode->delayed_iput_count == 0) {
3210 ASSERT(list_empty(&binode->delayed_iput));
3211 list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
3212 } else {
3213 binode->delayed_iput_count++;
3214 }
3215 spin_unlock(&fs_info->delayed_iput_lock);
3216 }
3217
3218 void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info)
3219 {
3220
3221 spin_lock(&fs_info->delayed_iput_lock);
3222 while (!list_empty(&fs_info->delayed_iputs)) {
3223 struct btrfs_inode *inode;
3224
3225 inode = list_first_entry(&fs_info->delayed_iputs,
3226 struct btrfs_inode, delayed_iput);
3227 if (inode->delayed_iput_count) {
3228 inode->delayed_iput_count--;
3229 list_move_tail(&inode->delayed_iput,
3230 &fs_info->delayed_iputs);
3231 } else {
3232 list_del_init(&inode->delayed_iput);
3233 }
3234 spin_unlock(&fs_info->delayed_iput_lock);
3235 iput(&inode->vfs_inode);
3236 spin_lock(&fs_info->delayed_iput_lock);
3237 }
3238 spin_unlock(&fs_info->delayed_iput_lock);
3239 }
3240
3241 /*
3242 * This is called in transaction commit time. If there are no orphan
3243 * files in the subvolume, it removes orphan item and frees block_rsv
3244 * structure.
3245 */
3246 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
3247 struct btrfs_root *root)
3248 {
3249 struct btrfs_fs_info *fs_info = root->fs_info;
3250 struct btrfs_block_rsv *block_rsv;
3251 int ret;
3252
3253 if (atomic_read(&root->orphan_inodes) ||
3254 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
3255 return;
3256
3257 spin_lock(&root->orphan_lock);
3258 if (atomic_read(&root->orphan_inodes)) {
3259 spin_unlock(&root->orphan_lock);
3260 return;
3261 }
3262
3263 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
3264 spin_unlock(&root->orphan_lock);
3265 return;
3266 }
3267
3268 block_rsv = root->orphan_block_rsv;
3269 root->orphan_block_rsv = NULL;
3270 spin_unlock(&root->orphan_lock);
3271
3272 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
3273 btrfs_root_refs(&root->root_item) > 0) {
3274 ret = btrfs_del_orphan_item(trans, fs_info->tree_root,
3275 root->root_key.objectid);
3276 if (ret)
3277 btrfs_abort_transaction(trans, ret);
3278 else
3279 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
3280 &root->state);
3281 }
3282
3283 if (block_rsv) {
3284 WARN_ON(block_rsv->size > 0);
3285 btrfs_free_block_rsv(fs_info, block_rsv);
3286 }
3287 }
3288
3289 /*
3290 * This creates an orphan entry for the given inode in case something goes
3291 * wrong in the middle of an unlink/truncate.
3292 *
3293 * NOTE: caller of this function should reserve 5 units of metadata for
3294 * this function.
3295 */
3296 int btrfs_orphan_add(struct btrfs_trans_handle *trans,
3297 struct btrfs_inode *inode)
3298 {
3299 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
3300 struct btrfs_root *root = inode->root;
3301 struct btrfs_block_rsv *block_rsv = NULL;
3302 int reserve = 0;
3303 int insert = 0;
3304 int ret;
3305
3306 if (!root->orphan_block_rsv) {
3307 block_rsv = btrfs_alloc_block_rsv(fs_info,
3308 BTRFS_BLOCK_RSV_TEMP);
3309 if (!block_rsv)
3310 return -ENOMEM;
3311 }
3312
3313 spin_lock(&root->orphan_lock);
3314 if (!root->orphan_block_rsv) {
3315 root->orphan_block_rsv = block_rsv;
3316 } else if (block_rsv) {
3317 btrfs_free_block_rsv(fs_info, block_rsv);
3318 block_rsv = NULL;
3319 }
3320
3321 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3322 &inode->runtime_flags)) {
3323 #if 0
3324 /*
3325 * For proper ENOSPC handling, we should do orphan
3326 * cleanup when mounting. But this introduces backward
3327 * compatibility issue.
3328 */
3329 if (!xchg(&root->orphan_item_inserted, 1))
3330 insert = 2;
3331 else
3332 insert = 1;
3333 #endif
3334 insert = 1;
3335 atomic_inc(&root->orphan_inodes);
3336 }
3337
3338 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3339 &inode->runtime_flags))
3340 reserve = 1;
3341 spin_unlock(&root->orphan_lock);
3342
3343 /* grab metadata reservation from transaction handle */
3344 if (reserve) {
3345 ret = btrfs_orphan_reserve_metadata(trans, inode);
3346 ASSERT(!ret);
3347 if (ret) {
3348 atomic_dec(&root->orphan_inodes);
3349 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3350 &inode->runtime_flags);
3351 if (insert)
3352 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3353 &inode->runtime_flags);
3354 return ret;
3355 }
3356 }
3357
3358 /* insert an orphan item to track this unlinked/truncated file */
3359 if (insert >= 1) {
3360 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3361 if (ret) {
3362 atomic_dec(&root->orphan_inodes);
3363 if (reserve) {
3364 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3365 &inode->runtime_flags);
3366 btrfs_orphan_release_metadata(inode);
3367 }
3368 if (ret != -EEXIST) {
3369 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3370 &inode->runtime_flags);
3371 btrfs_abort_transaction(trans, ret);
3372 return ret;
3373 }
3374 }
3375 ret = 0;
3376 }
3377
3378 /* insert an orphan item to track subvolume contains orphan files */
3379 if (insert >= 2) {
3380 ret = btrfs_insert_orphan_item(trans, fs_info->tree_root,
3381 root->root_key.objectid);
3382 if (ret && ret != -EEXIST) {
3383 btrfs_abort_transaction(trans, ret);
3384 return ret;
3385 }
3386 }
3387 return 0;
3388 }
3389
3390 /*
3391 * We have done the truncate/delete so we can go ahead and remove the orphan
3392 * item for this particular inode.
3393 */
3394 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3395 struct btrfs_inode *inode)
3396 {
3397 struct btrfs_root *root = inode->root;
3398 int delete_item = 0;
3399 int release_rsv = 0;
3400 int ret = 0;
3401
3402 spin_lock(&root->orphan_lock);
3403 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3404 &inode->runtime_flags))
3405 delete_item = 1;
3406
3407 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3408 &inode->runtime_flags))
3409 release_rsv = 1;
3410 spin_unlock(&root->orphan_lock);
3411
3412 if (delete_item) {
3413 atomic_dec(&root->orphan_inodes);
3414 if (trans)
3415 ret = btrfs_del_orphan_item(trans, root,
3416 btrfs_ino(inode));
3417 }
3418
3419 if (release_rsv)
3420 btrfs_orphan_release_metadata(inode);
3421
3422 return ret;
3423 }
3424
3425 /*
3426 * this cleans up any orphans that may be left on the list from the last use
3427 * of this root.
3428 */
3429 int btrfs_orphan_cleanup(struct btrfs_root *root)
3430 {
3431 struct btrfs_fs_info *fs_info = root->fs_info;
3432 struct btrfs_path *path;
3433 struct extent_buffer *leaf;
3434 struct btrfs_key key, found_key;
3435 struct btrfs_trans_handle *trans;
3436 struct inode *inode;
3437 u64 last_objectid = 0;
3438 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3439
3440 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3441 return 0;
3442
3443 path = btrfs_alloc_path();
3444 if (!path) {
3445 ret = -ENOMEM;
3446 goto out;
3447 }
3448 path->reada = READA_BACK;
3449
3450 key.objectid = BTRFS_ORPHAN_OBJECTID;
3451 key.type = BTRFS_ORPHAN_ITEM_KEY;
3452 key.offset = (u64)-1;
3453
3454 while (1) {
3455 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3456 if (ret < 0)
3457 goto out;
3458
3459 /*
3460 * if ret == 0 means we found what we were searching for, which
3461 * is weird, but possible, so only screw with path if we didn't
3462 * find the key and see if we have stuff that matches
3463 */
3464 if (ret > 0) {
3465 ret = 0;
3466 if (path->slots[0] == 0)
3467 break;
3468 path->slots[0]--;
3469 }
3470
3471 /* pull out the item */
3472 leaf = path->nodes[0];
3473 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3474
3475 /* make sure the item matches what we want */
3476 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3477 break;
3478 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3479 break;
3480
3481 /* release the path since we're done with it */
3482 btrfs_release_path(path);
3483
3484 /*
3485 * this is where we are basically btrfs_lookup, without the
3486 * crossing root thing. we store the inode number in the
3487 * offset of the orphan item.
3488 */
3489
3490 if (found_key.offset == last_objectid) {
3491 btrfs_err(fs_info,
3492 "Error removing orphan entry, stopping orphan cleanup");
3493 ret = -EINVAL;
3494 goto out;
3495 }
3496
3497 last_objectid = found_key.offset;
3498
3499 found_key.objectid = found_key.offset;
3500 found_key.type = BTRFS_INODE_ITEM_KEY;
3501 found_key.offset = 0;
3502 inode = btrfs_iget(fs_info->sb, &found_key, root, NULL);
3503 ret = PTR_ERR_OR_ZERO(inode);
3504 if (ret && ret != -ENOENT)
3505 goto out;
3506
3507 if (ret == -ENOENT && root == fs_info->tree_root) {
3508 struct btrfs_root *dead_root;
3509 struct btrfs_fs_info *fs_info = root->fs_info;
3510 int is_dead_root = 0;
3511
3512 /*
3513 * this is an orphan in the tree root. Currently these
3514 * could come from 2 sources:
3515 * a) a snapshot deletion in progress
3516 * b) a free space cache inode
3517 * We need to distinguish those two, as the snapshot
3518 * orphan must not get deleted.
3519 * find_dead_roots already ran before us, so if this
3520 * is a snapshot deletion, we should find the root
3521 * in the dead_roots list
3522 */
3523 spin_lock(&fs_info->trans_lock);
3524 list_for_each_entry(dead_root, &fs_info->dead_roots,
3525 root_list) {
3526 if (dead_root->root_key.objectid ==
3527 found_key.objectid) {
3528 is_dead_root = 1;
3529 break;
3530 }
3531 }
3532 spin_unlock(&fs_info->trans_lock);
3533 if (is_dead_root) {
3534 /* prevent this orphan from being found again */
3535 key.offset = found_key.objectid - 1;
3536 continue;
3537 }
3538 }
3539 /*
3540 * Inode is already gone but the orphan item is still there,
3541 * kill the orphan item.
3542 */
3543 if (ret == -ENOENT) {
3544 trans = btrfs_start_transaction(root, 1);
3545 if (IS_ERR(trans)) {
3546 ret = PTR_ERR(trans);
3547 goto out;
3548 }
3549 btrfs_debug(fs_info, "auto deleting %Lu",
3550 found_key.objectid);
3551 ret = btrfs_del_orphan_item(trans, root,
3552 found_key.objectid);
3553 btrfs_end_transaction(trans);
3554 if (ret)
3555 goto out;
3556 continue;
3557 }
3558
3559 /*
3560 * add this inode to the orphan list so btrfs_orphan_del does
3561 * the proper thing when we hit it
3562 */
3563 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3564 &BTRFS_I(inode)->runtime_flags);
3565 atomic_inc(&root->orphan_inodes);
3566
3567 /* if we have links, this was a truncate, lets do that */
3568 if (inode->i_nlink) {
3569 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3570 iput(inode);
3571 continue;
3572 }
3573 nr_truncate++;
3574
3575 /* 1 for the orphan item deletion. */
3576 trans = btrfs_start_transaction(root, 1);
3577 if (IS_ERR(trans)) {
3578 iput(inode);
3579 ret = PTR_ERR(trans);
3580 goto out;
3581 }
3582 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
3583 btrfs_end_transaction(trans);
3584 if (ret) {
3585 iput(inode);
3586 goto out;
3587 }
3588
3589 ret = btrfs_truncate(inode);
3590 if (ret)
3591 btrfs_orphan_del(NULL, BTRFS_I(inode));
3592 } else {
3593 nr_unlink++;
3594 }
3595
3596 /* this will do delete_inode and everything for us */
3597 iput(inode);
3598 if (ret)
3599 goto out;
3600 }
3601 /* release the path since we're done with it */
3602 btrfs_release_path(path);
3603
3604 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3605
3606 if (root->orphan_block_rsv)
3607 btrfs_block_rsv_release(fs_info, root->orphan_block_rsv,
3608 (u64)-1);
3609
3610 if (root->orphan_block_rsv ||
3611 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3612 trans = btrfs_join_transaction(root);
3613 if (!IS_ERR(trans))
3614 btrfs_end_transaction(trans);
3615 }
3616
3617 if (nr_unlink)
3618 btrfs_debug(fs_info, "unlinked %d orphans", nr_unlink);
3619 if (nr_truncate)
3620 btrfs_debug(fs_info, "truncated %d orphans", nr_truncate);
3621
3622 out:
3623 if (ret)
3624 btrfs_err(fs_info, "could not do orphan cleanup %d", ret);
3625 btrfs_free_path(path);
3626 return ret;
3627 }
3628
3629 /*
3630 * very simple check to peek ahead in the leaf looking for xattrs. If we
3631 * don't find any xattrs, we know there can't be any acls.
3632 *
3633 * slot is the slot the inode is in, objectid is the objectid of the inode
3634 */
3635 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3636 int slot, u64 objectid,
3637 int *first_xattr_slot)
3638 {
3639 u32 nritems = btrfs_header_nritems(leaf);
3640 struct btrfs_key found_key;
3641 static u64 xattr_access = 0;
3642 static u64 xattr_default = 0;
3643 int scanned = 0;
3644
3645 if (!xattr_access) {
3646 xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
3647 strlen(XATTR_NAME_POSIX_ACL_ACCESS));
3648 xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
3649 strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
3650 }
3651
3652 slot++;
3653 *first_xattr_slot = -1;
3654 while (slot < nritems) {
3655 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3656
3657 /* we found a different objectid, there must not be acls */
3658 if (found_key.objectid != objectid)
3659 return 0;
3660
3661 /* we found an xattr, assume we've got an acl */
3662 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3663 if (*first_xattr_slot == -1)
3664 *first_xattr_slot = slot;
3665 if (found_key.offset == xattr_access ||
3666 found_key.offset == xattr_default)
3667 return 1;
3668 }
3669
3670 /*
3671 * we found a key greater than an xattr key, there can't
3672 * be any acls later on
3673 */
3674 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3675 return 0;
3676
3677 slot++;
3678 scanned++;
3679
3680 /*
3681 * it goes inode, inode backrefs, xattrs, extents,
3682 * so if there are a ton of hard links to an inode there can
3683 * be a lot of backrefs. Don't waste time searching too hard,
3684 * this is just an optimization
3685 */
3686 if (scanned >= 8)
3687 break;
3688 }
3689 /* we hit the end of the leaf before we found an xattr or
3690 * something larger than an xattr. We have to assume the inode
3691 * has acls
3692 */
3693 if (*first_xattr_slot == -1)
3694 *first_xattr_slot = slot;
3695 return 1;
3696 }
3697
3698 /*
3699 * read an inode from the btree into the in-memory inode
3700 */
3701 static int btrfs_read_locked_inode(struct inode *inode)
3702 {
3703 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3704 struct btrfs_path *path;
3705 struct extent_buffer *leaf;
3706 struct btrfs_inode_item *inode_item;
3707 struct btrfs_root *root = BTRFS_I(inode)->root;
3708 struct btrfs_key location;
3709 unsigned long ptr;
3710 int maybe_acls;
3711 u32 rdev;
3712 int ret;
3713 bool filled = false;
3714 int first_xattr_slot;
3715
3716 ret = btrfs_fill_inode(inode, &rdev);
3717 if (!ret)
3718 filled = true;
3719
3720 path = btrfs_alloc_path();
3721 if (!path) {
3722 ret = -ENOMEM;
3723 goto make_bad;
3724 }
3725
3726 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3727
3728 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3729 if (ret) {
3730 if (ret > 0)
3731 ret = -ENOENT;
3732 goto make_bad;
3733 }
3734
3735 leaf = path->nodes[0];
3736
3737 if (filled)
3738 goto cache_index;
3739
3740 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3741 struct btrfs_inode_item);
3742 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3743 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3744 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3745 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3746 btrfs_i_size_write(BTRFS_I(inode), btrfs_inode_size(leaf, inode_item));
3747
3748 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3749 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3750
3751 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3752 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3753
3754 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3755 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3756
3757 BTRFS_I(inode)->i_otime.tv_sec =
3758 btrfs_timespec_sec(leaf, &inode_item->otime);
3759 BTRFS_I(inode)->i_otime.tv_nsec =
3760 btrfs_timespec_nsec(leaf, &inode_item->otime);
3761
3762 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3763 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3764 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3765
3766 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3767 inode->i_generation = BTRFS_I(inode)->generation;
3768 inode->i_rdev = 0;
3769 rdev = btrfs_inode_rdev(leaf, inode_item);
3770
3771 BTRFS_I(inode)->index_cnt = (u64)-1;
3772 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3773
3774 cache_index:
3775 /*
3776 * If we were modified in the current generation and evicted from memory
3777 * and then re-read we need to do a full sync since we don't have any
3778 * idea about which extents were modified before we were evicted from
3779 * cache.
3780 *
3781 * This is required for both inode re-read from disk and delayed inode
3782 * in delayed_nodes_tree.
3783 */
3784 if (BTRFS_I(inode)->last_trans == fs_info->generation)
3785 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3786 &BTRFS_I(inode)->runtime_flags);
3787
3788 /*
3789 * We don't persist the id of the transaction where an unlink operation
3790 * against the inode was last made. So here we assume the inode might
3791 * have been evicted, and therefore the exact value of last_unlink_trans
3792 * lost, and set it to last_trans to avoid metadata inconsistencies
3793 * between the inode and its parent if the inode is fsync'ed and the log
3794 * replayed. For example, in the scenario:
3795 *
3796 * touch mydir/foo
3797 * ln mydir/foo mydir/bar
3798 * sync
3799 * unlink mydir/bar
3800 * echo 2 > /proc/sys/vm/drop_caches # evicts inode
3801 * xfs_io -c fsync mydir/foo
3802 * <power failure>
3803 * mount fs, triggers fsync log replay
3804 *
3805 * We must make sure that when we fsync our inode foo we also log its
3806 * parent inode, otherwise after log replay the parent still has the
3807 * dentry with the "bar" name but our inode foo has a link count of 1
3808 * and doesn't have an inode ref with the name "bar" anymore.
3809 *
3810 * Setting last_unlink_trans to last_trans is a pessimistic approach,
3811 * but it guarantees correctness at the expense of occasional full
3812 * transaction commits on fsync if our inode is a directory, or if our
3813 * inode is not a directory, logging its parent unnecessarily.
3814 */
3815 BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
3816
3817 path->slots[0]++;
3818 if (inode->i_nlink != 1 ||
3819 path->slots[0] >= btrfs_header_nritems(leaf))
3820 goto cache_acl;
3821
3822 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3823 if (location.objectid != btrfs_ino(BTRFS_I(inode)))
3824 goto cache_acl;
3825
3826 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3827 if (location.type == BTRFS_INODE_REF_KEY) {
3828 struct btrfs_inode_ref *ref;
3829
3830 ref = (struct btrfs_inode_ref *)ptr;
3831 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3832 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3833 struct btrfs_inode_extref *extref;
3834
3835 extref = (struct btrfs_inode_extref *)ptr;
3836 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3837 extref);
3838 }
3839 cache_acl:
3840 /*
3841 * try to precache a NULL acl entry for files that don't have
3842 * any xattrs or acls
3843 */
3844 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3845 btrfs_ino(BTRFS_I(inode)), &first_xattr_slot);
3846 if (first_xattr_slot != -1) {
3847 path->slots[0] = first_xattr_slot;
3848 ret = btrfs_load_inode_props(inode, path);
3849 if (ret)
3850 btrfs_err(fs_info,
3851 "error loading props for ino %llu (root %llu): %d",
3852 btrfs_ino(BTRFS_I(inode)),
3853 root->root_key.objectid, ret);
3854 }
3855 btrfs_free_path(path);
3856
3857 if (!maybe_acls)
3858 cache_no_acl(inode);
3859
3860 switch (inode->i_mode & S_IFMT) {
3861 case S_IFREG:
3862 inode->i_mapping->a_ops = &btrfs_aops;
3863 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3864 inode->i_fop = &btrfs_file_operations;
3865 inode->i_op = &btrfs_file_inode_operations;
3866 break;
3867 case S_IFDIR:
3868 inode->i_fop = &btrfs_dir_file_operations;
3869 inode->i_op = &btrfs_dir_inode_operations;
3870 break;
3871 case S_IFLNK:
3872 inode->i_op = &btrfs_symlink_inode_operations;
3873 inode_nohighmem(inode);
3874 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3875 break;
3876 default:
3877 inode->i_op = &btrfs_special_inode_operations;
3878 init_special_inode(inode, inode->i_mode, rdev);
3879 break;
3880 }
3881
3882 btrfs_update_iflags(inode);
3883 return 0;
3884
3885 make_bad:
3886 btrfs_free_path(path);
3887 make_bad_inode(inode);
3888 return ret;
3889 }
3890
3891 /*
3892 * given a leaf and an inode, copy the inode fields into the leaf
3893 */
3894 static void fill_inode_item(struct btrfs_trans_handle *trans,
3895 struct extent_buffer *leaf,
3896 struct btrfs_inode_item *item,
3897 struct inode *inode)
3898 {
3899 struct btrfs_map_token token;
3900
3901 btrfs_init_map_token(&token);
3902
3903 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3904 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3905 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3906 &token);
3907 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3908 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3909
3910 btrfs_set_token_timespec_sec(leaf, &item->atime,
3911 inode->i_atime.tv_sec, &token);
3912 btrfs_set_token_timespec_nsec(leaf, &item->atime,
3913 inode->i_atime.tv_nsec, &token);
3914
3915 btrfs_set_token_timespec_sec(leaf, &item->mtime,
3916 inode->i_mtime.tv_sec, &token);
3917 btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3918 inode->i_mtime.tv_nsec, &token);
3919
3920 btrfs_set_token_timespec_sec(leaf, &item->ctime,
3921 inode->i_ctime.tv_sec, &token);
3922 btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3923 inode->i_ctime.tv_nsec, &token);
3924
3925 btrfs_set_token_timespec_sec(leaf, &item->otime,
3926 BTRFS_I(inode)->i_otime.tv_sec, &token);
3927 btrfs_set_token_timespec_nsec(leaf, &item->otime,
3928 BTRFS_I(inode)->i_otime.tv_nsec, &token);
3929
3930 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3931 &token);
3932 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3933 &token);
3934 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3935 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3936 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3937 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3938 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3939 }
3940
3941 /*
3942 * copy everything in the in-memory inode into the btree.
3943 */
3944 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3945 struct btrfs_root *root, struct inode *inode)
3946 {
3947 struct btrfs_inode_item *inode_item;
3948 struct btrfs_path *path;
3949 struct extent_buffer *leaf;
3950 int ret;
3951
3952 path = btrfs_alloc_path();
3953 if (!path)
3954 return -ENOMEM;
3955
3956 path->leave_spinning = 1;
3957 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3958 1);
3959 if (ret) {
3960 if (ret > 0)
3961 ret = -ENOENT;
3962 goto failed;
3963 }
3964
3965 leaf = path->nodes[0];
3966 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3967 struct btrfs_inode_item);
3968
3969 fill_inode_item(trans, leaf, inode_item, inode);
3970 btrfs_mark_buffer_dirty(leaf);
3971 btrfs_set_inode_last_trans(trans, inode);
3972 ret = 0;
3973 failed:
3974 btrfs_free_path(path);
3975 return ret;
3976 }
3977
3978 /*
3979 * copy everything in the in-memory inode into the btree.
3980 */
3981 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3982 struct btrfs_root *root, struct inode *inode)
3983 {
3984 struct btrfs_fs_info *fs_info = root->fs_info;
3985 int ret;
3986
3987 /*
3988 * If the inode is a free space inode, we can deadlock during commit
3989 * if we put it into the delayed code.
3990 *
3991 * The data relocation inode should also be directly updated
3992 * without delay
3993 */
3994 if (!btrfs_is_free_space_inode(BTRFS_I(inode))
3995 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
3996 && !test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
3997 btrfs_update_root_times(trans, root);
3998
3999 ret = btrfs_delayed_update_inode(trans, root, inode);
4000 if (!ret)
4001 btrfs_set_inode_last_trans(trans, inode);
4002 return ret;
4003 }
4004
4005 return btrfs_update_inode_item(trans, root, inode);
4006 }
4007
4008 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
4009 struct btrfs_root *root,
4010 struct inode *inode)
4011 {
4012 int ret;
4013
4014 ret = btrfs_update_inode(trans, root, inode);
4015 if (ret == -ENOSPC)
4016 return btrfs_update_inode_item(trans, root, inode);
4017 return ret;
4018 }
4019
4020 /*
4021 * unlink helper that gets used here in inode.c and in the tree logging
4022 * recovery code. It remove a link in a directory with a given name, and
4023 * also drops the back refs in the inode to the directory
4024 */
4025 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4026 struct btrfs_root *root,
4027 struct btrfs_inode *dir,
4028 struct btrfs_inode *inode,
4029 const char *name, int name_len)
4030 {
4031 struct btrfs_fs_info *fs_info = root->fs_info;
4032 struct btrfs_path *path;
4033 int ret = 0;
4034 struct extent_buffer *leaf;
4035 struct btrfs_dir_item *di;
4036 struct btrfs_key key;
4037 u64 index;
4038 u64 ino = btrfs_ino(inode);
4039 u64 dir_ino = btrfs_ino(dir);
4040
4041 path = btrfs_alloc_path();
4042 if (!path) {
4043 ret = -ENOMEM;
4044 goto out;
4045 }
4046
4047 path->leave_spinning = 1;
4048 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4049 name, name_len, -1);
4050 if (IS_ERR(di)) {
4051 ret = PTR_ERR(di);
4052 goto err;
4053 }
4054 if (!di) {
4055 ret = -ENOENT;
4056 goto err;
4057 }
4058 leaf = path->nodes[0];
4059 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4060 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4061 if (ret)
4062 goto err;
4063 btrfs_release_path(path);
4064
4065 /*
4066 * If we don't have dir index, we have to get it by looking up
4067 * the inode ref, since we get the inode ref, remove it directly,
4068 * it is unnecessary to do delayed deletion.
4069 *
4070 * But if we have dir index, needn't search inode ref to get it.
4071 * Since the inode ref is close to the inode item, it is better
4072 * that we delay to delete it, and just do this deletion when
4073 * we update the inode item.
4074 */
4075 if (inode->dir_index) {
4076 ret = btrfs_delayed_delete_inode_ref(inode);
4077 if (!ret) {
4078 index = inode->dir_index;
4079 goto skip_backref;
4080 }
4081 }
4082
4083 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
4084 dir_ino, &index);
4085 if (ret) {
4086 btrfs_info(fs_info,
4087 "failed to delete reference to %.*s, inode %llu parent %llu",
4088 name_len, name, ino, dir_ino);
4089 btrfs_abort_transaction(trans, ret);
4090 goto err;
4091 }
4092 skip_backref:
4093 ret = btrfs_delete_delayed_dir_index(trans, fs_info, dir, index);
4094 if (ret) {
4095 btrfs_abort_transaction(trans, ret);
4096 goto err;
4097 }
4098
4099 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, inode,
4100 dir_ino);
4101 if (ret != 0 && ret != -ENOENT) {
4102 btrfs_abort_transaction(trans, ret);
4103 goto err;
4104 }
4105
4106 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, dir,
4107 index);
4108 if (ret == -ENOENT)
4109 ret = 0;
4110 else if (ret)
4111 btrfs_abort_transaction(trans, ret);
4112 err:
4113 btrfs_free_path(path);
4114 if (ret)
4115 goto out;
4116
4117 btrfs_i_size_write(dir, dir->vfs_inode.i_size - name_len * 2);
4118 inode_inc_iversion(&inode->vfs_inode);
4119 inode_inc_iversion(&dir->vfs_inode);
4120 inode->vfs_inode.i_ctime = dir->vfs_inode.i_mtime =
4121 dir->vfs_inode.i_ctime = current_time(&inode->vfs_inode);
4122 ret = btrfs_update_inode(trans, root, &dir->vfs_inode);
4123 out:
4124 return ret;
4125 }
4126
4127 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4128 struct btrfs_root *root,
4129 struct btrfs_inode *dir, struct btrfs_inode *inode,
4130 const char *name, int name_len)
4131 {
4132 int ret;
4133 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
4134 if (!ret) {
4135 drop_nlink(&inode->vfs_inode);
4136 ret = btrfs_update_inode(trans, root, &inode->vfs_inode);
4137 }
4138 return ret;
4139 }
4140
4141 /*
4142 * helper to start transaction for unlink and rmdir.
4143 *
4144 * unlink and rmdir are special in btrfs, they do not always free space, so
4145 * if we cannot make our reservations the normal way try and see if there is
4146 * plenty of slack room in the global reserve to migrate, otherwise we cannot
4147 * allow the unlink to occur.
4148 */
4149 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
4150 {
4151 struct btrfs_root *root = BTRFS_I(dir)->root;
4152
4153 /*
4154 * 1 for the possible orphan item
4155 * 1 for the dir item
4156 * 1 for the dir index
4157 * 1 for the inode ref
4158 * 1 for the inode
4159 */
4160 return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
4161 }
4162
4163 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4164 {
4165 struct btrfs_root *root = BTRFS_I(dir)->root;
4166 struct btrfs_trans_handle *trans;
4167 struct inode *inode = d_inode(dentry);
4168 int ret;
4169
4170 trans = __unlink_start_trans(dir);
4171 if (IS_ERR(trans))
4172 return PTR_ERR(trans);
4173
4174 btrfs_record_unlink_dir(trans, BTRFS_I(dir), BTRFS_I(d_inode(dentry)),
4175 0);
4176
4177 ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
4178 BTRFS_I(d_inode(dentry)), dentry->d_name.name,
4179 dentry->d_name.len);
4180 if (ret)
4181 goto out;
4182
4183 if (inode->i_nlink == 0) {
4184 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
4185 if (ret)
4186 goto out;
4187 }
4188
4189 out:
4190 btrfs_end_transaction(trans);
4191 btrfs_btree_balance_dirty(root->fs_info);
4192 return ret;
4193 }
4194
4195 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4196 struct btrfs_root *root,
4197 struct inode *dir, u64 objectid,
4198 const char *name, int name_len)
4199 {
4200 struct btrfs_fs_info *fs_info = root->fs_info;
4201 struct btrfs_path *path;
4202 struct extent_buffer *leaf;
4203 struct btrfs_dir_item *di;
4204 struct btrfs_key key;
4205 u64 index;
4206 int ret;
4207 u64 dir_ino = btrfs_ino(BTRFS_I(dir));
4208
4209 path = btrfs_alloc_path();
4210 if (!path)
4211 return -ENOMEM;
4212
4213 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4214 name, name_len, -1);
4215 if (IS_ERR_OR_NULL(di)) {
4216 if (!di)
4217 ret = -ENOENT;
4218 else
4219 ret = PTR_ERR(di);
4220 goto out;
4221 }
4222
4223 leaf = path->nodes[0];
4224 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4225 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4226 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4227 if (ret) {
4228 btrfs_abort_transaction(trans, ret);
4229 goto out;
4230 }
4231 btrfs_release_path(path);
4232
4233 ret = btrfs_del_root_ref(trans, fs_info, objectid,
4234 root->root_key.objectid, dir_ino,
4235 &index, name, name_len);
4236 if (ret < 0) {
4237 if (ret != -ENOENT) {
4238 btrfs_abort_transaction(trans, ret);
4239 goto out;
4240 }
4241 di = btrfs_search_dir_index_item(root, path, dir_ino,
4242 name, name_len);
4243 if (IS_ERR_OR_NULL(di)) {
4244 if (!di)
4245 ret = -ENOENT;
4246 else
4247 ret = PTR_ERR(di);
4248 btrfs_abort_transaction(trans, ret);
4249 goto out;
4250 }
4251
4252 leaf = path->nodes[0];
4253 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4254 btrfs_release_path(path);
4255 index = key.offset;
4256 }
4257 btrfs_release_path(path);
4258
4259 ret = btrfs_delete_delayed_dir_index(trans, fs_info, BTRFS_I(dir), index);
4260 if (ret) {
4261 btrfs_abort_transaction(trans, ret);
4262 goto out;
4263 }
4264
4265 btrfs_i_size_write(BTRFS_I(dir), dir->i_size - name_len * 2);
4266 inode_inc_iversion(dir);
4267 dir->i_mtime = dir->i_ctime = current_time(dir);
4268 ret = btrfs_update_inode_fallback(trans, root, dir);
4269 if (ret)
4270 btrfs_abort_transaction(trans, ret);
4271 out:
4272 btrfs_free_path(path);
4273 return ret;
4274 }
4275
4276 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4277 {
4278 struct inode *inode = d_inode(dentry);
4279 int err = 0;
4280 struct btrfs_root *root = BTRFS_I(dir)->root;
4281 struct btrfs_trans_handle *trans;
4282 u64 last_unlink_trans;
4283
4284 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4285 return -ENOTEMPTY;
4286 if (btrfs_ino(BTRFS_I(inode)) == BTRFS_FIRST_FREE_OBJECTID)
4287 return -EPERM;
4288
4289 trans = __unlink_start_trans(dir);
4290 if (IS_ERR(trans))
4291 return PTR_ERR(trans);
4292
4293 if (unlikely(btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4294 err = btrfs_unlink_subvol(trans, root, dir,
4295 BTRFS_I(inode)->location.objectid,
4296 dentry->d_name.name,
4297 dentry->d_name.len);
4298 goto out;
4299 }
4300
4301 err = btrfs_orphan_add(trans, BTRFS_I(inode));
4302 if (err)
4303 goto out;
4304
4305 last_unlink_trans = BTRFS_I(inode)->last_unlink_trans;
4306
4307 /* now the directory is empty */
4308 err = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
4309 BTRFS_I(d_inode(dentry)), dentry->d_name.name,
4310 dentry->d_name.len);
4311 if (!err) {
4312 btrfs_i_size_write(BTRFS_I(inode), 0);
4313 /*
4314 * Propagate the last_unlink_trans value of the deleted dir to
4315 * its parent directory. This is to prevent an unrecoverable
4316 * log tree in the case we do something like this:
4317 * 1) create dir foo
4318 * 2) create snapshot under dir foo
4319 * 3) delete the snapshot
4320 * 4) rmdir foo
4321 * 5) mkdir foo
4322 * 6) fsync foo or some file inside foo
4323 */
4324 if (last_unlink_trans >= trans->transid)
4325 BTRFS_I(dir)->last_unlink_trans = last_unlink_trans;
4326 }
4327 out:
4328 btrfs_end_transaction(trans);
4329 btrfs_btree_balance_dirty(root->fs_info);
4330
4331 return err;
4332 }
4333
4334 static int truncate_space_check(struct btrfs_trans_handle *trans,
4335 struct btrfs_root *root,
4336 u64 bytes_deleted)
4337 {
4338 struct btrfs_fs_info *fs_info = root->fs_info;
4339 int ret;
4340
4341 /*
4342 * This is only used to apply pressure to the enospc system, we don't
4343 * intend to use this reservation at all.
4344 */
4345 bytes_deleted = btrfs_csum_bytes_to_leaves(fs_info, bytes_deleted);
4346 bytes_deleted *= fs_info->nodesize;
4347 ret = btrfs_block_rsv_add(root, &fs_info->trans_block_rsv,
4348 bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
4349 if (!ret) {
4350 trace_btrfs_space_reservation(fs_info, "transaction",
4351 trans->transid,
4352 bytes_deleted, 1);
4353 trans->bytes_reserved += bytes_deleted;
4354 }
4355 return ret;
4356
4357 }
4358
4359 static int truncate_inline_extent(struct inode *inode,
4360 struct btrfs_path *path,
4361 struct btrfs_key *found_key,
4362 const u64 item_end,
4363 const u64 new_size)
4364 {
4365 struct extent_buffer *leaf = path->nodes[0];
4366 int slot = path->slots[0];
4367 struct btrfs_file_extent_item *fi;
4368 u32 size = (u32)(new_size - found_key->offset);
4369 struct btrfs_root *root = BTRFS_I(inode)->root;
4370
4371 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
4372
4373 if (btrfs_file_extent_compression(leaf, fi) != BTRFS_COMPRESS_NONE) {
4374 loff_t offset = new_size;
4375 loff_t page_end = ALIGN(offset, PAGE_SIZE);
4376
4377 /*
4378 * Zero out the remaining of the last page of our inline extent,
4379 * instead of directly truncating our inline extent here - that
4380 * would be much more complex (decompressing all the data, then
4381 * compressing the truncated data, which might be bigger than
4382 * the size of the inline extent, resize the extent, etc).
4383 * We release the path because to get the page we might need to
4384 * read the extent item from disk (data not in the page cache).
4385 */
4386 btrfs_release_path(path);
4387 return btrfs_truncate_block(inode, offset, page_end - offset,
4388 0);
4389 }
4390
4391 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4392 size = btrfs_file_extent_calc_inline_size(size);
4393 btrfs_truncate_item(root->fs_info, path, size, 1);
4394
4395 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4396 inode_sub_bytes(inode, item_end + 1 - new_size);
4397
4398 return 0;
4399 }
4400
4401 /*
4402 * this can truncate away extent items, csum items and directory items.
4403 * It starts at a high offset and removes keys until it can't find
4404 * any higher than new_size
4405 *
4406 * csum items that cross the new i_size are truncated to the new size
4407 * as well.
4408 *
4409 * min_type is the minimum key type to truncate down to. If set to 0, this
4410 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4411 */
4412 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4413 struct btrfs_root *root,
4414 struct inode *inode,
4415 u64 new_size, u32 min_type)
4416 {
4417 struct btrfs_fs_info *fs_info = root->fs_info;
4418 struct btrfs_path *path;
4419 struct extent_buffer *leaf;
4420 struct btrfs_file_extent_item *fi;
4421 struct btrfs_key key;
4422 struct btrfs_key found_key;
4423 u64 extent_start = 0;
4424 u64 extent_num_bytes = 0;
4425 u64 extent_offset = 0;
4426 u64 item_end = 0;
4427 u64 last_size = new_size;
4428 u32 found_type = (u8)-1;
4429 int found_extent;
4430 int del_item;
4431 int pending_del_nr = 0;
4432 int pending_del_slot = 0;
4433 int extent_type = -1;
4434 int ret;
4435 int err = 0;
4436 u64 ino = btrfs_ino(BTRFS_I(inode));
4437 u64 bytes_deleted = 0;
4438 bool be_nice = 0;
4439 bool should_throttle = 0;
4440 bool should_end = 0;
4441
4442 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4443
4444 /*
4445 * for non-free space inodes and ref cows, we want to back off from
4446 * time to time
4447 */
4448 if (!btrfs_is_free_space_inode(BTRFS_I(inode)) &&
4449 test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4450 be_nice = 1;
4451
4452 path = btrfs_alloc_path();
4453 if (!path)
4454 return -ENOMEM;
4455 path->reada = READA_BACK;
4456
4457 /*
4458 * We want to drop from the next block forward in case this new size is
4459 * not block aligned since we will be keeping the last block of the
4460 * extent just the way it is.
4461 */
4462 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4463 root == fs_info->tree_root)
4464 btrfs_drop_extent_cache(BTRFS_I(inode), ALIGN(new_size,
4465 fs_info->sectorsize),
4466 (u64)-1, 0);
4467
4468 /*
4469 * This function is also used to drop the items in the log tree before
4470 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4471 * it is used to drop the loged items. So we shouldn't kill the delayed
4472 * items.
4473 */
4474 if (min_type == 0 && root == BTRFS_I(inode)->root)
4475 btrfs_kill_delayed_inode_items(BTRFS_I(inode));
4476
4477 key.objectid = ino;
4478 key.offset = (u64)-1;
4479 key.type = (u8)-1;
4480
4481 search_again:
4482 /*
4483 * with a 16K leaf size and 128MB extents, you can actually queue
4484 * up a huge file in a single leaf. Most of the time that
4485 * bytes_deleted is > 0, it will be huge by the time we get here
4486 */
4487 if (be_nice && bytes_deleted > SZ_32M) {
4488 if (btrfs_should_end_transaction(trans)) {
4489 err = -EAGAIN;
4490 goto error;
4491 }
4492 }
4493
4494
4495 path->leave_spinning = 1;
4496 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4497 if (ret < 0) {
4498 err = ret;
4499 goto out;
4500 }
4501
4502 if (ret > 0) {
4503 /* there are no items in the tree for us to truncate, we're
4504 * done
4505 */
4506 if (path->slots[0] == 0)
4507 goto out;
4508 path->slots[0]--;
4509 }
4510
4511 while (1) {
4512 fi = NULL;
4513 leaf = path->nodes[0];
4514 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4515 found_type = found_key.type;
4516
4517 if (found_key.objectid != ino)
4518 break;
4519
4520 if (found_type < min_type)
4521 break;
4522
4523 item_end = found_key.offset;
4524 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4525 fi = btrfs_item_ptr(leaf, path->slots[0],
4526 struct btrfs_file_extent_item);
4527 extent_type = btrfs_file_extent_type(leaf, fi);
4528 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4529 item_end +=
4530 btrfs_file_extent_num_bytes(leaf, fi);
4531
4532 trace_btrfs_truncate_show_fi_regular(
4533 BTRFS_I(inode), leaf, fi,
4534 found_key.offset);
4535 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4536 item_end += btrfs_file_extent_inline_len(leaf,
4537 path->slots[0], fi);
4538
4539 trace_btrfs_truncate_show_fi_inline(
4540 BTRFS_I(inode), leaf, fi, path->slots[0],
4541 found_key.offset);
4542 }
4543 item_end--;
4544 }
4545 if (found_type > min_type) {
4546 del_item = 1;
4547 } else {
4548 if (item_end < new_size)
4549 break;
4550 if (found_key.offset >= new_size)
4551 del_item = 1;
4552 else
4553 del_item = 0;
4554 }
4555 found_extent = 0;
4556 /* FIXME, shrink the extent if the ref count is only 1 */
4557 if (found_type != BTRFS_EXTENT_DATA_KEY)
4558 goto delete;
4559
4560 if (del_item)
4561 last_size = found_key.offset;
4562 else
4563 last_size = new_size;
4564
4565 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4566 u64 num_dec;
4567 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4568 if (!del_item) {
4569 u64 orig_num_bytes =
4570 btrfs_file_extent_num_bytes(leaf, fi);
4571 extent_num_bytes = ALIGN(new_size -
4572 found_key.offset,
4573 fs_info->sectorsize);
4574 btrfs_set_file_extent_num_bytes(leaf, fi,
4575 extent_num_bytes);
4576 num_dec = (orig_num_bytes -
4577 extent_num_bytes);
4578 if (test_bit(BTRFS_ROOT_REF_COWS,
4579 &root->state) &&
4580 extent_start != 0)
4581 inode_sub_bytes(inode, num_dec);
4582 btrfs_mark_buffer_dirty(leaf);
4583 } else {
4584 extent_num_bytes =
4585 btrfs_file_extent_disk_num_bytes(leaf,
4586 fi);
4587 extent_offset = found_key.offset -
4588 btrfs_file_extent_offset(leaf, fi);
4589
4590 /* FIXME blocksize != 4096 */
4591 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4592 if (extent_start != 0) {
4593 found_extent = 1;
4594 if (test_bit(BTRFS_ROOT_REF_COWS,
4595 &root->state))
4596 inode_sub_bytes(inode, num_dec);
4597 }
4598 }
4599 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4600 /*
4601 * we can't truncate inline items that have had
4602 * special encodings
4603 */
4604 if (!del_item &&
4605 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4606 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4607
4608 /*
4609 * Need to release path in order to truncate a
4610 * compressed extent. So delete any accumulated
4611 * extent items so far.
4612 */
4613 if (btrfs_file_extent_compression(leaf, fi) !=
4614 BTRFS_COMPRESS_NONE && pending_del_nr) {
4615 err = btrfs_del_items(trans, root, path,
4616 pending_del_slot,
4617 pending_del_nr);
4618 if (err) {
4619 btrfs_abort_transaction(trans,
4620 err);
4621 goto error;
4622 }
4623 pending_del_nr = 0;
4624 }
4625
4626 err = truncate_inline_extent(inode, path,
4627 &found_key,
4628 item_end,
4629 new_size);
4630 if (err) {
4631 btrfs_abort_transaction(trans, err);
4632 goto error;
4633 }
4634 } else if (test_bit(BTRFS_ROOT_REF_COWS,
4635 &root->state)) {
4636 inode_sub_bytes(inode, item_end + 1 - new_size);
4637 }
4638 }
4639 delete:
4640 if (del_item) {
4641 if (!pending_del_nr) {
4642 /* no pending yet, add ourselves */
4643 pending_del_slot = path->slots[0];
4644 pending_del_nr = 1;
4645 } else if (pending_del_nr &&
4646 path->slots[0] + 1 == pending_del_slot) {
4647 /* hop on the pending chunk */
4648 pending_del_nr++;
4649 pending_del_slot = path->slots[0];
4650 } else {
4651 BUG();
4652 }
4653 } else {
4654 break;
4655 }
4656 should_throttle = 0;
4657
4658 if (found_extent &&
4659 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4660 root == fs_info->tree_root)) {
4661 btrfs_set_path_blocking(path);
4662 bytes_deleted += extent_num_bytes;
4663 ret = btrfs_free_extent(trans, fs_info, extent_start,
4664 extent_num_bytes, 0,
4665 btrfs_header_owner(leaf),
4666 ino, extent_offset);
4667 BUG_ON(ret);
4668 if (btrfs_should_throttle_delayed_refs(trans, fs_info))
4669 btrfs_async_run_delayed_refs(fs_info,
4670 trans->delayed_ref_updates * 2,
4671 trans->transid, 0);
4672 if (be_nice) {
4673 if (truncate_space_check(trans, root,
4674 extent_num_bytes)) {
4675 should_end = 1;
4676 }
4677 if (btrfs_should_throttle_delayed_refs(trans,
4678 fs_info))
4679 should_throttle = 1;
4680 }
4681 }
4682
4683 if (found_type == BTRFS_INODE_ITEM_KEY)
4684 break;
4685
4686 if (path->slots[0] == 0 ||
4687 path->slots[0] != pending_del_slot ||
4688 should_throttle || should_end) {
4689 if (pending_del_nr) {
4690 ret = btrfs_del_items(trans, root, path,
4691 pending_del_slot,
4692 pending_del_nr);
4693 if (ret) {
4694 btrfs_abort_transaction(trans, ret);
4695 goto error;
4696 }
4697 pending_del_nr = 0;
4698 }
4699 btrfs_release_path(path);
4700 if (should_throttle) {
4701 unsigned long updates = trans->delayed_ref_updates;
4702 if (updates) {
4703 trans->delayed_ref_updates = 0;
4704 ret = btrfs_run_delayed_refs(trans,
4705 fs_info,
4706 updates * 2);
4707 if (ret && !err)
4708 err = ret;
4709 }
4710 }
4711 /*
4712 * if we failed to refill our space rsv, bail out
4713 * and let the transaction restart
4714 */
4715 if (should_end) {
4716 err = -EAGAIN;
4717 goto error;
4718 }
4719 goto search_again;
4720 } else {
4721 path->slots[0]--;
4722 }
4723 }
4724 out:
4725 if (pending_del_nr) {
4726 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4727 pending_del_nr);
4728 if (ret)
4729 btrfs_abort_transaction(trans, ret);
4730 }
4731 error:
4732 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
4733 ASSERT(last_size >= new_size);
4734 if (!err && last_size > new_size)
4735 last_size = new_size;
4736 btrfs_ordered_update_i_size(inode, last_size, NULL);
4737 }
4738
4739 btrfs_free_path(path);
4740
4741 if (be_nice && bytes_deleted > SZ_32M) {
4742 unsigned long updates = trans->delayed_ref_updates;
4743 if (updates) {
4744 trans->delayed_ref_updates = 0;
4745 ret = btrfs_run_delayed_refs(trans, fs_info,
4746 updates * 2);
4747 if (ret && !err)
4748 err = ret;
4749 }
4750 }
4751 return err;
4752 }
4753
4754 /*
4755 * btrfs_truncate_block - read, zero a chunk and write a block
4756 * @inode - inode that we're zeroing
4757 * @from - the offset to start zeroing
4758 * @len - the length to zero, 0 to zero the entire range respective to the
4759 * offset
4760 * @front - zero up to the offset instead of from the offset on
4761 *
4762 * This will find the block for the "from" offset and cow the block and zero the
4763 * part we want to zero. This is used with truncate and hole punching.
4764 */
4765 int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
4766 int front)
4767 {
4768 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4769 struct address_space *mapping = inode->i_mapping;
4770 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4771 struct btrfs_ordered_extent *ordered;
4772 struct extent_state *cached_state = NULL;
4773 struct extent_changeset *data_reserved = NULL;
4774 char *kaddr;
4775 u32 blocksize = fs_info->sectorsize;
4776 pgoff_t index = from >> PAGE_SHIFT;
4777 unsigned offset = from & (blocksize - 1);
4778 struct page *page;
4779 gfp_t mask = btrfs_alloc_write_mask(mapping);
4780 int ret = 0;
4781 u64 block_start;
4782 u64 block_end;
4783
4784 if ((offset & (blocksize - 1)) == 0 &&
4785 (!len || ((len & (blocksize - 1)) == 0)))
4786 goto out;
4787
4788 ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
4789 round_down(from, blocksize), blocksize);
4790 if (ret)
4791 goto out;
4792
4793 again:
4794 page = find_or_create_page(mapping, index, mask);
4795 if (!page) {
4796 btrfs_delalloc_release_space(inode, data_reserved,
4797 round_down(from, blocksize),
4798 blocksize);
4799 ret = -ENOMEM;
4800 goto out;
4801 }
4802
4803 block_start = round_down(from, blocksize);
4804 block_end = block_start + blocksize - 1;
4805
4806 if (!PageUptodate(page)) {
4807 ret = btrfs_readpage(NULL, page);
4808 lock_page(page);
4809 if (page->mapping != mapping) {
4810 unlock_page(page);
4811 put_page(page);
4812 goto again;
4813 }
4814 if (!PageUptodate(page)) {
4815 ret = -EIO;
4816 goto out_unlock;
4817 }
4818 }
4819 wait_on_page_writeback(page);
4820
4821 lock_extent_bits(io_tree, block_start, block_end, &cached_state);
4822 set_page_extent_mapped(page);
4823
4824 ordered = btrfs_lookup_ordered_extent(inode, block_start);
4825 if (ordered) {
4826 unlock_extent_cached(io_tree, block_start, block_end,
4827 &cached_state, GFP_NOFS);
4828 unlock_page(page);
4829 put_page(page);
4830 btrfs_start_ordered_extent(inode, ordered, 1);
4831 btrfs_put_ordered_extent(ordered);
4832 goto again;
4833 }
4834
4835 clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end,
4836 EXTENT_DIRTY | EXTENT_DELALLOC |
4837 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4838 0, 0, &cached_state, GFP_NOFS);
4839
4840 ret = btrfs_set_extent_delalloc(inode, block_start, block_end,
4841 &cached_state, 0);
4842 if (ret) {
4843 unlock_extent_cached(io_tree, block_start, block_end,
4844 &cached_state, GFP_NOFS);
4845 goto out_unlock;
4846 }
4847
4848 if (offset != blocksize) {
4849 if (!len)
4850 len = blocksize - offset;
4851 kaddr = kmap(page);
4852 if (front)
4853 memset(kaddr + (block_start - page_offset(page)),
4854 0, offset);
4855 else
4856 memset(kaddr + (block_start - page_offset(page)) + offset,
4857 0, len);
4858 flush_dcache_page(page);
4859 kunmap(page);
4860 }
4861 ClearPageChecked(page);
4862 set_page_dirty(page);
4863 unlock_extent_cached(io_tree, block_start, block_end, &cached_state,
4864 GFP_NOFS);
4865
4866 out_unlock:
4867 if (ret)
4868 btrfs_delalloc_release_space(inode, data_reserved, block_start,
4869 blocksize);
4870 unlock_page(page);
4871 put_page(page);
4872 out:
4873 extent_changeset_free(data_reserved);
4874 return ret;
4875 }
4876
4877 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4878 u64 offset, u64 len)
4879 {
4880 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4881 struct btrfs_trans_handle *trans;
4882 int ret;
4883
4884 /*
4885 * Still need to make sure the inode looks like it's been updated so
4886 * that any holes get logged if we fsync.
4887 */
4888 if (btrfs_fs_incompat(fs_info, NO_HOLES)) {
4889 BTRFS_I(inode)->last_trans = fs_info->generation;
4890 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4891 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4892 return 0;
4893 }
4894
4895 /*
4896 * 1 - for the one we're dropping
4897 * 1 - for the one we're adding
4898 * 1 - for updating the inode.
4899 */
4900 trans = btrfs_start_transaction(root, 3);
4901 if (IS_ERR(trans))
4902 return PTR_ERR(trans);
4903
4904 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4905 if (ret) {
4906 btrfs_abort_transaction(trans, ret);
4907 btrfs_end_transaction(trans);
4908 return ret;
4909 }
4910
4911 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(BTRFS_I(inode)),
4912 offset, 0, 0, len, 0, len, 0, 0, 0);
4913 if (ret)
4914 btrfs_abort_transaction(trans, ret);
4915 else
4916 btrfs_update_inode(trans, root, inode);
4917 btrfs_end_transaction(trans);
4918 return ret;
4919 }
4920
4921 /*
4922 * This function puts in dummy file extents for the area we're creating a hole
4923 * for. So if we are truncating this file to a larger size we need to insert
4924 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4925 * the range between oldsize and size
4926 */
4927 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4928 {
4929 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4930 struct btrfs_root *root = BTRFS_I(inode)->root;
4931 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4932 struct extent_map *em = NULL;
4933 struct extent_state *cached_state = NULL;
4934 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4935 u64 hole_start = ALIGN(oldsize, fs_info->sectorsize);
4936 u64 block_end = ALIGN(size, fs_info->sectorsize);
4937 u64 last_byte;
4938 u64 cur_offset;
4939 u64 hole_size;
4940 int err = 0;
4941
4942 /*
4943 * If our size started in the middle of a block we need to zero out the
4944 * rest of the block before we expand the i_size, otherwise we could
4945 * expose stale data.
4946 */
4947 err = btrfs_truncate_block(inode, oldsize, 0, 0);
4948 if (err)
4949 return err;
4950
4951 if (size <= hole_start)
4952 return 0;
4953
4954 while (1) {
4955 struct btrfs_ordered_extent *ordered;
4956
4957 lock_extent_bits(io_tree, hole_start, block_end - 1,
4958 &cached_state);
4959 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), hole_start,
4960 block_end - hole_start);
4961 if (!ordered)
4962 break;
4963 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4964 &cached_state, GFP_NOFS);
4965 btrfs_start_ordered_extent(inode, ordered, 1);
4966 btrfs_put_ordered_extent(ordered);
4967 }
4968
4969 cur_offset = hole_start;
4970 while (1) {
4971 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset,
4972 block_end - cur_offset, 0);
4973 if (IS_ERR(em)) {
4974 err = PTR_ERR(em);
4975 em = NULL;
4976 break;
4977 }
4978 last_byte = min(extent_map_end(em), block_end);
4979 last_byte = ALIGN(last_byte, fs_info->sectorsize);
4980 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4981 struct extent_map *hole_em;
4982 hole_size = last_byte - cur_offset;
4983
4984 err = maybe_insert_hole(root, inode, cur_offset,
4985 hole_size);
4986 if (err)
4987 break;
4988 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
4989 cur_offset + hole_size - 1, 0);
4990 hole_em = alloc_extent_map();
4991 if (!hole_em) {
4992 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4993 &BTRFS_I(inode)->runtime_flags);
4994 goto next;
4995 }
4996 hole_em->start = cur_offset;
4997 hole_em->len = hole_size;
4998 hole_em->orig_start = cur_offset;
4999
5000 hole_em->block_start = EXTENT_MAP_HOLE;
5001 hole_em->block_len = 0;
5002 hole_em->orig_block_len = 0;
5003 hole_em->ram_bytes = hole_size;
5004 hole_em->bdev = fs_info->fs_devices->latest_bdev;
5005 hole_em->compress_type = BTRFS_COMPRESS_NONE;
5006 hole_em->generation = fs_info->generation;
5007
5008 while (1) {
5009 write_lock(&em_tree->lock);
5010 err = add_extent_mapping(em_tree, hole_em, 1);
5011 write_unlock(&em_tree->lock);
5012 if (err != -EEXIST)
5013 break;
5014 btrfs_drop_extent_cache(BTRFS_I(inode),
5015 cur_offset,
5016 cur_offset +
5017 hole_size - 1, 0);
5018 }
5019 free_extent_map(hole_em);
5020 }
5021 next:
5022 free_extent_map(em);
5023 em = NULL;
5024 cur_offset = last_byte;
5025 if (cur_offset >= block_end)
5026 break;
5027 }
5028 free_extent_map(em);
5029 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
5030 GFP_NOFS);
5031 return err;
5032 }
5033
5034 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
5035 {
5036 struct btrfs_root *root = BTRFS_I(inode)->root;
5037 struct btrfs_trans_handle *trans;
5038 loff_t oldsize = i_size_read(inode);
5039 loff_t newsize = attr->ia_size;
5040 int mask = attr->ia_valid;
5041 int ret;
5042
5043 /*
5044 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
5045 * special case where we need to update the times despite not having
5046 * these flags set. For all other operations the VFS set these flags
5047 * explicitly if it wants a timestamp update.
5048 */
5049 if (newsize != oldsize) {
5050 inode_inc_iversion(inode);
5051 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
5052 inode->i_ctime = inode->i_mtime =
5053 current_time(inode);
5054 }
5055
5056 if (newsize > oldsize) {
5057 /*
5058 * Don't do an expanding truncate while snapshoting is ongoing.
5059 * This is to ensure the snapshot captures a fully consistent
5060 * state of this file - if the snapshot captures this expanding
5061 * truncation, it must capture all writes that happened before
5062 * this truncation.
5063 */
5064 btrfs_wait_for_snapshot_creation(root);
5065 ret = btrfs_cont_expand(inode, oldsize, newsize);
5066 if (ret) {
5067 btrfs_end_write_no_snapshoting(root);
5068 return ret;
5069 }
5070
5071 trans = btrfs_start_transaction(root, 1);
5072 if (IS_ERR(trans)) {
5073 btrfs_end_write_no_snapshoting(root);
5074 return PTR_ERR(trans);
5075 }
5076
5077 i_size_write(inode, newsize);
5078 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
5079 pagecache_isize_extended(inode, oldsize, newsize);
5080 ret = btrfs_update_inode(trans, root, inode);
5081 btrfs_end_write_no_snapshoting(root);
5082 btrfs_end_transaction(trans);
5083 } else {
5084
5085 /*
5086 * We're truncating a file that used to have good data down to
5087 * zero. Make sure it gets into the ordered flush list so that
5088 * any new writes get down to disk quickly.
5089 */
5090 if (newsize == 0)
5091 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
5092 &BTRFS_I(inode)->runtime_flags);
5093
5094 /*
5095 * 1 for the orphan item we're going to add
5096 * 1 for the orphan item deletion.
5097 */
5098 trans = btrfs_start_transaction(root, 2);
5099 if (IS_ERR(trans))
5100 return PTR_ERR(trans);
5101
5102 /*
5103 * We need to do this in case we fail at _any_ point during the
5104 * actual truncate. Once we do the truncate_setsize we could
5105 * invalidate pages which forces any outstanding ordered io to
5106 * be instantly completed which will give us extents that need
5107 * to be truncated. If we fail to get an orphan inode down we
5108 * could have left over extents that were never meant to live,
5109 * so we need to guarantee from this point on that everything
5110 * will be consistent.
5111 */
5112 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
5113 btrfs_end_transaction(trans);
5114 if (ret)
5115 return ret;
5116
5117 /* we don't support swapfiles, so vmtruncate shouldn't fail */
5118 truncate_setsize(inode, newsize);
5119
5120 /* Disable nonlocked read DIO to avoid the end less truncate */
5121 btrfs_inode_block_unlocked_dio(BTRFS_I(inode));
5122 inode_dio_wait(inode);
5123 btrfs_inode_resume_unlocked_dio(BTRFS_I(inode));
5124
5125 ret = btrfs_truncate(inode);
5126 if (ret && inode->i_nlink) {
5127 int err;
5128
5129 /* To get a stable disk_i_size */
5130 err = btrfs_wait_ordered_range(inode, 0, (u64)-1);
5131 if (err) {
5132 btrfs_orphan_del(NULL, BTRFS_I(inode));
5133 return err;
5134 }
5135
5136 /*
5137 * failed to truncate, disk_i_size is only adjusted down
5138 * as we remove extents, so it should represent the true
5139 * size of the inode, so reset the in memory size and
5140 * delete our orphan entry.
5141 */
5142 trans = btrfs_join_transaction(root);
5143 if (IS_ERR(trans)) {
5144 btrfs_orphan_del(NULL, BTRFS_I(inode));
5145 return ret;
5146 }
5147 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
5148 err = btrfs_orphan_del(trans, BTRFS_I(inode));
5149 if (err)
5150 btrfs_abort_transaction(trans, err);
5151 btrfs_end_transaction(trans);
5152 }
5153 }
5154
5155 return ret;
5156 }
5157
5158 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
5159 {
5160 struct inode *inode = d_inode(dentry);
5161 struct btrfs_root *root = BTRFS_I(inode)->root;
5162 int err;
5163
5164 if (btrfs_root_readonly(root))
5165 return -EROFS;
5166
5167 err = setattr_prepare(dentry, attr);
5168 if (err)
5169 return err;
5170
5171 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
5172 err = btrfs_setsize(inode, attr);
5173 if (err)
5174 return err;
5175 }
5176
5177 if (attr->ia_valid) {
5178 setattr_copy(inode, attr);
5179 inode_inc_iversion(inode);
5180 err = btrfs_dirty_inode(inode);
5181
5182 if (!err && attr->ia_valid & ATTR_MODE)
5183 err = posix_acl_chmod(inode, inode->i_mode);
5184 }
5185
5186 return err;
5187 }
5188
5189 /*
5190 * While truncating the inode pages during eviction, we get the VFS calling
5191 * btrfs_invalidatepage() against each page of the inode. This is slow because
5192 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
5193 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
5194 * extent_state structures over and over, wasting lots of time.
5195 *
5196 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
5197 * those expensive operations on a per page basis and do only the ordered io
5198 * finishing, while we release here the extent_map and extent_state structures,
5199 * without the excessive merging and splitting.
5200 */
5201 static void evict_inode_truncate_pages(struct inode *inode)
5202 {
5203 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5204 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
5205 struct rb_node *node;
5206
5207 ASSERT(inode->i_state & I_FREEING);
5208 truncate_inode_pages_final(&inode->i_data);
5209
5210 write_lock(&map_tree->lock);
5211 while (!RB_EMPTY_ROOT(&map_tree->map)) {
5212 struct extent_map *em;
5213
5214 node = rb_first(&map_tree->map);
5215 em = rb_entry(node, struct extent_map, rb_node);
5216 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
5217 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
5218 remove_extent_mapping(map_tree, em);
5219 free_extent_map(em);
5220 if (need_resched()) {
5221 write_unlock(&map_tree->lock);
5222 cond_resched();
5223 write_lock(&map_tree->lock);
5224 }
5225 }
5226 write_unlock(&map_tree->lock);
5227
5228 /*
5229 * Keep looping until we have no more ranges in the io tree.
5230 * We can have ongoing bios started by readpages (called from readahead)
5231 * that have their endio callback (extent_io.c:end_bio_extent_readpage)
5232 * still in progress (unlocked the pages in the bio but did not yet
5233 * unlocked the ranges in the io tree). Therefore this means some
5234 * ranges can still be locked and eviction started because before
5235 * submitting those bios, which are executed by a separate task (work
5236 * queue kthread), inode references (inode->i_count) were not taken
5237 * (which would be dropped in the end io callback of each bio).
5238 * Therefore here we effectively end up waiting for those bios and
5239 * anyone else holding locked ranges without having bumped the inode's
5240 * reference count - if we don't do it, when they access the inode's
5241 * io_tree to unlock a range it may be too late, leading to an
5242 * use-after-free issue.
5243 */
5244 spin_lock(&io_tree->lock);
5245 while (!RB_EMPTY_ROOT(&io_tree->state)) {
5246 struct extent_state *state;
5247 struct extent_state *cached_state = NULL;
5248 u64 start;
5249 u64 end;
5250
5251 node = rb_first(&io_tree->state);
5252 state = rb_entry(node, struct extent_state, rb_node);
5253 start = state->start;
5254 end = state->end;
5255 spin_unlock(&io_tree->lock);
5256
5257 lock_extent_bits(io_tree, start, end, &cached_state);
5258
5259 /*
5260 * If still has DELALLOC flag, the extent didn't reach disk,
5261 * and its reserved space won't be freed by delayed_ref.
5262 * So we need to free its reserved space here.
5263 * (Refer to comment in btrfs_invalidatepage, case 2)
5264 *
5265 * Note, end is the bytenr of last byte, so we need + 1 here.
5266 */
5267 if (state->state & EXTENT_DELALLOC)
5268 btrfs_qgroup_free_data(inode, NULL, start, end - start + 1);
5269
5270 clear_extent_bit(io_tree, start, end,
5271 EXTENT_LOCKED | EXTENT_DIRTY |
5272 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
5273 EXTENT_DEFRAG, 1, 1,
5274 &cached_state, GFP_NOFS);
5275
5276 cond_resched();
5277 spin_lock(&io_tree->lock);
5278 }
5279 spin_unlock(&io_tree->lock);
5280 }
5281
5282 void btrfs_evict_inode(struct inode *inode)
5283 {
5284 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5285 struct btrfs_trans_handle *trans;
5286 struct btrfs_root *root = BTRFS_I(inode)->root;
5287 struct btrfs_block_rsv *rsv, *global_rsv;
5288 int steal_from_global = 0;
5289 u64 min_size;
5290 int ret;
5291
5292 trace_btrfs_inode_evict(inode);
5293
5294 if (!root) {
5295 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
5296 return;
5297 }
5298
5299 min_size = btrfs_calc_trunc_metadata_size(fs_info, 1);
5300
5301 evict_inode_truncate_pages(inode);
5302
5303 if (inode->i_nlink &&
5304 ((btrfs_root_refs(&root->root_item) != 0 &&
5305 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5306 btrfs_is_free_space_inode(BTRFS_I(inode))))
5307 goto no_delete;
5308
5309 if (is_bad_inode(inode)) {
5310 btrfs_orphan_del(NULL, BTRFS_I(inode));
5311 goto no_delete;
5312 }
5313 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
5314 if (!special_file(inode->i_mode))
5315 btrfs_wait_ordered_range(inode, 0, (u64)-1);
5316
5317 btrfs_free_io_failure_record(BTRFS_I(inode), 0, (u64)-1);
5318
5319 if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
5320 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
5321 &BTRFS_I(inode)->runtime_flags));
5322 goto no_delete;
5323 }
5324
5325 if (inode->i_nlink > 0) {
5326 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5327 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5328 goto no_delete;
5329 }
5330
5331 ret = btrfs_commit_inode_delayed_inode(BTRFS_I(inode));
5332 if (ret) {
5333 btrfs_orphan_del(NULL, BTRFS_I(inode));
5334 goto no_delete;
5335 }
5336
5337 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
5338 if (!rsv) {
5339 btrfs_orphan_del(NULL, BTRFS_I(inode));
5340 goto no_delete;
5341 }
5342 rsv->size = min_size;
5343 rsv->failfast = 1;
5344 global_rsv = &fs_info->global_block_rsv;
5345
5346 btrfs_i_size_write(BTRFS_I(inode), 0);
5347
5348 /*
5349 * This is a bit simpler than btrfs_truncate since we've already
5350 * reserved our space for our orphan item in the unlink, so we just
5351 * need to reserve some slack space in case we add bytes and update
5352 * inode item when doing the truncate.
5353 */
5354 while (1) {
5355 ret = btrfs_block_rsv_refill(root, rsv, min_size,
5356 BTRFS_RESERVE_FLUSH_LIMIT);
5357
5358 /*
5359 * Try and steal from the global reserve since we will
5360 * likely not use this space anyway, we want to try as
5361 * hard as possible to get this to work.
5362 */
5363 if (ret)
5364 steal_from_global++;
5365 else
5366 steal_from_global = 0;
5367 ret = 0;
5368
5369 /*
5370 * steal_from_global == 0: we reserved stuff, hooray!
5371 * steal_from_global == 1: we didn't reserve stuff, boo!
5372 * steal_from_global == 2: we've committed, still not a lot of
5373 * room but maybe we'll have room in the global reserve this
5374 * time.
5375 * steal_from_global == 3: abandon all hope!
5376 */
5377 if (steal_from_global > 2) {
5378 btrfs_warn(fs_info,
5379 "Could not get space for a delete, will truncate on mount %d",
5380 ret);
5381 btrfs_orphan_del(NULL, BTRFS_I(inode));
5382 btrfs_free_block_rsv(fs_info, rsv);
5383 goto no_delete;
5384 }
5385
5386 trans = btrfs_join_transaction(root);
5387 if (IS_ERR(trans)) {
5388 btrfs_orphan_del(NULL, BTRFS_I(inode));
5389 btrfs_free_block_rsv(fs_info, rsv);
5390 goto no_delete;
5391 }
5392
5393 /*
5394 * We can't just steal from the global reserve, we need to make
5395 * sure there is room to do it, if not we need to commit and try
5396 * again.
5397 */
5398 if (steal_from_global) {
5399 if (!btrfs_check_space_for_delayed_refs(trans, fs_info))
5400 ret = btrfs_block_rsv_migrate(global_rsv, rsv,
5401 min_size, 0);
5402 else
5403 ret = -ENOSPC;
5404 }
5405
5406 /*
5407 * Couldn't steal from the global reserve, we have too much
5408 * pending stuff built up, commit the transaction and try it
5409 * again.
5410 */
5411 if (ret) {
5412 ret = btrfs_commit_transaction(trans);
5413 if (ret) {
5414 btrfs_orphan_del(NULL, BTRFS_I(inode));
5415 btrfs_free_block_rsv(fs_info, rsv);
5416 goto no_delete;
5417 }
5418 continue;
5419 } else {
5420 steal_from_global = 0;
5421 }
5422
5423 trans->block_rsv = rsv;
5424
5425 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5426 if (ret != -ENOSPC && ret != -EAGAIN)
5427 break;
5428
5429 trans->block_rsv = &fs_info->trans_block_rsv;
5430 btrfs_end_transaction(trans);
5431 trans = NULL;
5432 btrfs_btree_balance_dirty(fs_info);
5433 }
5434
5435 btrfs_free_block_rsv(fs_info, rsv);
5436
5437 /*
5438 * Errors here aren't a big deal, it just means we leave orphan items
5439 * in the tree. They will be cleaned up on the next mount.
5440 */
5441 if (ret == 0) {
5442 trans->block_rsv = root->orphan_block_rsv;
5443 btrfs_orphan_del(trans, BTRFS_I(inode));
5444 } else {
5445 btrfs_orphan_del(NULL, BTRFS_I(inode));
5446 }
5447
5448 trans->block_rsv = &fs_info->trans_block_rsv;
5449 if (!(root == fs_info->tree_root ||
5450 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5451 btrfs_return_ino(root, btrfs_ino(BTRFS_I(inode)));
5452
5453 btrfs_end_transaction(trans);
5454 btrfs_btree_balance_dirty(fs_info);
5455 no_delete:
5456 btrfs_remove_delayed_node(BTRFS_I(inode));
5457 clear_inode(inode);
5458 }
5459
5460 /*
5461 * this returns the key found in the dir entry in the location pointer.
5462 * If no dir entries were found, location->objectid is 0.
5463 */
5464 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5465 struct btrfs_key *location)
5466 {
5467 const char *name = dentry->d_name.name;
5468 int namelen = dentry->d_name.len;
5469 struct btrfs_dir_item *di;
5470 struct btrfs_path *path;
5471 struct btrfs_root *root = BTRFS_I(dir)->root;
5472 int ret = 0;
5473
5474 path = btrfs_alloc_path();
5475 if (!path)
5476 return -ENOMEM;
5477
5478 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(BTRFS_I(dir)),
5479 name, namelen, 0);
5480 if (IS_ERR(di))
5481 ret = PTR_ERR(di);
5482
5483 if (IS_ERR_OR_NULL(di))
5484 goto out_err;
5485
5486 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5487 out:
5488 btrfs_free_path(path);
5489 return ret;
5490 out_err:
5491 location->objectid = 0;
5492 goto out;
5493 }
5494
5495 /*
5496 * when we hit a tree root in a directory, the btrfs part of the inode
5497 * needs to be changed to reflect the root directory of the tree root. This
5498 * is kind of like crossing a mount point.
5499 */
5500 static int fixup_tree_root_location(struct btrfs_fs_info *fs_info,
5501 struct inode *dir,
5502 struct dentry *dentry,
5503 struct btrfs_key *location,
5504 struct btrfs_root **sub_root)
5505 {
5506 struct btrfs_path *path;
5507 struct btrfs_root *new_root;
5508 struct btrfs_root_ref *ref;
5509 struct extent_buffer *leaf;
5510 struct btrfs_key key;
5511 int ret;
5512 int err = 0;
5513
5514 path = btrfs_alloc_path();
5515 if (!path) {
5516 err = -ENOMEM;
5517 goto out;
5518 }
5519
5520 err = -ENOENT;
5521 key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5522 key.type = BTRFS_ROOT_REF_KEY;
5523 key.offset = location->objectid;
5524
5525 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
5526 if (ret) {
5527 if (ret < 0)
5528 err = ret;
5529 goto out;
5530 }
5531
5532 leaf = path->nodes[0];
5533 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5534 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(BTRFS_I(dir)) ||
5535 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5536 goto out;
5537
5538 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5539 (unsigned long)(ref + 1),
5540 dentry->d_name.len);
5541 if (ret)
5542 goto out;
5543
5544 btrfs_release_path(path);
5545
5546 new_root = btrfs_read_fs_root_no_name(fs_info, location);
5547 if (IS_ERR(new_root)) {
5548 err = PTR_ERR(new_root);
5549 goto out;
5550 }
5551
5552 *sub_root = new_root;
5553 location->objectid = btrfs_root_dirid(&new_root->root_item);
5554 location->type = BTRFS_INODE_ITEM_KEY;
5555 location->offset = 0;
5556 err = 0;
5557 out:
5558 btrfs_free_path(path);
5559 return err;
5560 }
5561
5562 static void inode_tree_add(struct inode *inode)
5563 {
5564 struct btrfs_root *root = BTRFS_I(inode)->root;
5565 struct btrfs_inode *entry;
5566 struct rb_node **p;
5567 struct rb_node *parent;
5568 struct rb_node *new = &BTRFS_I(inode)->rb_node;
5569 u64 ino = btrfs_ino(BTRFS_I(inode));
5570
5571 if (inode_unhashed(inode))
5572 return;
5573 parent = NULL;
5574 spin_lock(&root->inode_lock);
5575 p = &root->inode_tree.rb_node;
5576 while (*p) {
5577 parent = *p;
5578 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5579
5580 if (ino < btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5581 p = &parent->rb_left;
5582 else if (ino > btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5583 p = &parent->rb_right;
5584 else {
5585 WARN_ON(!(entry->vfs_inode.i_state &
5586 (I_WILL_FREE | I_FREEING)));
5587 rb_replace_node(parent, new, &root->inode_tree);
5588 RB_CLEAR_NODE(parent);
5589 spin_unlock(&root->inode_lock);
5590 return;
5591 }
5592 }
5593 rb_link_node(new, parent, p);
5594 rb_insert_color(new, &root->inode_tree);
5595 spin_unlock(&root->inode_lock);
5596 }
5597
5598 static void inode_tree_del(struct inode *inode)
5599 {
5600 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5601 struct btrfs_root *root = BTRFS_I(inode)->root;
5602 int empty = 0;
5603
5604 spin_lock(&root->inode_lock);
5605 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5606 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5607 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5608 empty = RB_EMPTY_ROOT(&root->inode_tree);
5609 }
5610 spin_unlock(&root->inode_lock);
5611
5612 if (empty && btrfs_root_refs(&root->root_item) == 0) {
5613 synchronize_srcu(&fs_info->subvol_srcu);
5614 spin_lock(&root->inode_lock);
5615 empty = RB_EMPTY_ROOT(&root->inode_tree);
5616 spin_unlock(&root->inode_lock);
5617 if (empty)
5618 btrfs_add_dead_root(root);
5619 }
5620 }
5621
5622 void btrfs_invalidate_inodes(struct btrfs_root *root)
5623 {
5624 struct btrfs_fs_info *fs_info = root->fs_info;
5625 struct rb_node *node;
5626 struct rb_node *prev;
5627 struct btrfs_inode *entry;
5628 struct inode *inode;
5629 u64 objectid = 0;
5630
5631 if (!test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
5632 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
5633
5634 spin_lock(&root->inode_lock);
5635 again:
5636 node = root->inode_tree.rb_node;
5637 prev = NULL;
5638 while (node) {
5639 prev = node;
5640 entry = rb_entry(node, struct btrfs_inode, rb_node);
5641
5642 if (objectid < btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5643 node = node->rb_left;
5644 else if (objectid > btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5645 node = node->rb_right;
5646 else
5647 break;
5648 }
5649 if (!node) {
5650 while (prev) {
5651 entry = rb_entry(prev, struct btrfs_inode, rb_node);
5652 if (objectid <= btrfs_ino(BTRFS_I(&entry->vfs_inode))) {
5653 node = prev;
5654 break;
5655 }
5656 prev = rb_next(prev);
5657 }
5658 }
5659 while (node) {
5660 entry = rb_entry(node, struct btrfs_inode, rb_node);
5661 objectid = btrfs_ino(BTRFS_I(&entry->vfs_inode)) + 1;
5662 inode = igrab(&entry->vfs_inode);
5663 if (inode) {
5664 spin_unlock(&root->inode_lock);
5665 if (atomic_read(&inode->i_count) > 1)
5666 d_prune_aliases(inode);
5667 /*
5668 * btrfs_drop_inode will have it removed from
5669 * the inode cache when its usage count
5670 * hits zero.
5671 */
5672 iput(inode);
5673 cond_resched();
5674 spin_lock(&root->inode_lock);
5675 goto again;
5676 }
5677
5678 if (cond_resched_lock(&root->inode_lock))
5679 goto again;
5680
5681 node = rb_next(node);
5682 }
5683 spin_unlock(&root->inode_lock);
5684 }
5685
5686 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5687 {
5688 struct btrfs_iget_args *args = p;
5689 inode->i_ino = args->location->objectid;
5690 memcpy(&BTRFS_I(inode)->location, args->location,
5691 sizeof(*args->location));
5692 BTRFS_I(inode)->root = args->root;
5693 return 0;
5694 }
5695
5696 static int btrfs_find_actor(struct inode *inode, void *opaque)
5697 {
5698 struct btrfs_iget_args *args = opaque;
5699 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5700 args->root == BTRFS_I(inode)->root;
5701 }
5702
5703 static struct inode *btrfs_iget_locked(struct super_block *s,
5704 struct btrfs_key *location,
5705 struct btrfs_root *root)
5706 {
5707 struct inode *inode;
5708 struct btrfs_iget_args args;
5709 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5710
5711 args.location = location;
5712 args.root = root;
5713
5714 inode = iget5_locked(s, hashval, btrfs_find_actor,
5715 btrfs_init_locked_inode,
5716 (void *)&args);
5717 return inode;
5718 }
5719
5720 /* Get an inode object given its location and corresponding root.
5721 * Returns in *is_new if the inode was read from disk
5722 */
5723 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5724 struct btrfs_root *root, int *new)
5725 {
5726 struct inode *inode;
5727
5728 inode = btrfs_iget_locked(s, location, root);
5729 if (!inode)
5730 return ERR_PTR(-ENOMEM);
5731
5732 if (inode->i_state & I_NEW) {
5733 int ret;
5734
5735 ret = btrfs_read_locked_inode(inode);
5736 if (!is_bad_inode(inode)) {
5737 inode_tree_add(inode);
5738 unlock_new_inode(inode);
5739 if (new)
5740 *new = 1;
5741 } else {
5742 unlock_new_inode(inode);
5743 iput(inode);
5744 ASSERT(ret < 0);
5745 inode = ERR_PTR(ret < 0 ? ret : -ESTALE);
5746 }
5747 }
5748
5749 return inode;
5750 }
5751
5752 static struct inode *new_simple_dir(struct super_block *s,
5753 struct btrfs_key *key,
5754 struct btrfs_root *root)
5755 {
5756 struct inode *inode = new_inode(s);
5757
5758 if (!inode)
5759 return ERR_PTR(-ENOMEM);
5760
5761 BTRFS_I(inode)->root = root;
5762 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5763 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5764
5765 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5766 inode->i_op = &btrfs_dir_ro_inode_operations;
5767 inode->i_opflags &= ~IOP_XATTR;
5768 inode->i_fop = &simple_dir_operations;
5769 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5770 inode->i_mtime = current_time(inode);
5771 inode->i_atime = inode->i_mtime;
5772 inode->i_ctime = inode->i_mtime;
5773 BTRFS_I(inode)->i_otime = inode->i_mtime;
5774
5775 return inode;
5776 }
5777
5778 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5779 {
5780 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
5781 struct inode *inode;
5782 struct btrfs_root *root = BTRFS_I(dir)->root;
5783 struct btrfs_root *sub_root = root;
5784 struct btrfs_key location;
5785 int index;
5786 int ret = 0;
5787
5788 if (dentry->d_name.len > BTRFS_NAME_LEN)
5789 return ERR_PTR(-ENAMETOOLONG);
5790
5791 ret = btrfs_inode_by_name(dir, dentry, &location);
5792 if (ret < 0)
5793 return ERR_PTR(ret);
5794
5795 if (location.objectid == 0)
5796 return ERR_PTR(-ENOENT);
5797
5798 if (location.type == BTRFS_INODE_ITEM_KEY) {
5799 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5800 return inode;
5801 }
5802
5803 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5804
5805 index = srcu_read_lock(&fs_info->subvol_srcu);
5806 ret = fixup_tree_root_location(fs_info, dir, dentry,
5807 &location, &sub_root);
5808 if (ret < 0) {
5809 if (ret != -ENOENT)
5810 inode = ERR_PTR(ret);
5811 else
5812 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5813 } else {
5814 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5815 }
5816 srcu_read_unlock(&fs_info->subvol_srcu, index);
5817
5818 if (!IS_ERR(inode) && root != sub_root) {
5819 down_read(&fs_info->cleanup_work_sem);
5820 if (!(inode->i_sb->s_flags & MS_RDONLY))
5821 ret = btrfs_orphan_cleanup(sub_root);
5822 up_read(&fs_info->cleanup_work_sem);
5823 if (ret) {
5824 iput(inode);
5825 inode = ERR_PTR(ret);
5826 }
5827 }
5828
5829 return inode;
5830 }
5831
5832 static int btrfs_dentry_delete(const struct dentry *dentry)
5833 {
5834 struct btrfs_root *root;
5835 struct inode *inode = d_inode(dentry);
5836
5837 if (!inode && !IS_ROOT(dentry))
5838 inode = d_inode(dentry->d_parent);
5839
5840 if (inode) {
5841 root = BTRFS_I(inode)->root;
5842 if (btrfs_root_refs(&root->root_item) == 0)
5843 return 1;
5844
5845 if (btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5846 return 1;
5847 }
5848 return 0;
5849 }
5850
5851 static void btrfs_dentry_release(struct dentry *dentry)
5852 {
5853 kfree(dentry->d_fsdata);
5854 }
5855
5856 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5857 unsigned int flags)
5858 {
5859 struct inode *inode;
5860
5861 inode = btrfs_lookup_dentry(dir, dentry);
5862 if (IS_ERR(inode)) {
5863 if (PTR_ERR(inode) == -ENOENT)
5864 inode = NULL;
5865 else
5866 return ERR_CAST(inode);
5867 }
5868
5869 return d_splice_alias(inode, dentry);
5870 }
5871
5872 unsigned char btrfs_filetype_table[] = {
5873 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5874 };
5875
5876 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5877 {
5878 struct inode *inode = file_inode(file);
5879 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5880 struct btrfs_root *root = BTRFS_I(inode)->root;
5881 struct btrfs_dir_item *di;
5882 struct btrfs_key key;
5883 struct btrfs_key found_key;
5884 struct btrfs_path *path;
5885 struct list_head ins_list;
5886 struct list_head del_list;
5887 int ret;
5888 struct extent_buffer *leaf;
5889 int slot;
5890 unsigned char d_type;
5891 int over = 0;
5892 char tmp_name[32];
5893 char *name_ptr;
5894 int name_len;
5895 bool put = false;
5896 struct btrfs_key location;
5897
5898 if (!dir_emit_dots(file, ctx))
5899 return 0;
5900
5901 path = btrfs_alloc_path();
5902 if (!path)
5903 return -ENOMEM;
5904
5905 path->reada = READA_FORWARD;
5906
5907 INIT_LIST_HEAD(&ins_list);
5908 INIT_LIST_HEAD(&del_list);
5909 put = btrfs_readdir_get_delayed_items(inode, &ins_list, &del_list);
5910
5911 key.type = BTRFS_DIR_INDEX_KEY;
5912 key.offset = ctx->pos;
5913 key.objectid = btrfs_ino(BTRFS_I(inode));
5914
5915 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5916 if (ret < 0)
5917 goto err;
5918
5919 while (1) {
5920 leaf = path->nodes[0];
5921 slot = path->slots[0];
5922 if (slot >= btrfs_header_nritems(leaf)) {
5923 ret = btrfs_next_leaf(root, path);
5924 if (ret < 0)
5925 goto err;
5926 else if (ret > 0)
5927 break;
5928 continue;
5929 }
5930
5931 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5932
5933 if (found_key.objectid != key.objectid)
5934 break;
5935 if (found_key.type != BTRFS_DIR_INDEX_KEY)
5936 break;
5937 if (found_key.offset < ctx->pos)
5938 goto next;
5939 if (btrfs_should_delete_dir_index(&del_list, found_key.offset))
5940 goto next;
5941
5942 ctx->pos = found_key.offset;
5943
5944 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5945 if (verify_dir_item(fs_info, leaf, slot, di))
5946 goto next;
5947
5948 name_len = btrfs_dir_name_len(leaf, di);
5949 if (name_len <= sizeof(tmp_name)) {
5950 name_ptr = tmp_name;
5951 } else {
5952 name_ptr = kmalloc(name_len, GFP_KERNEL);
5953 if (!name_ptr) {
5954 ret = -ENOMEM;
5955 goto err;
5956 }
5957 }
5958 read_extent_buffer(leaf, name_ptr, (unsigned long)(di + 1),
5959 name_len);
5960
5961 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5962 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5963
5964 over = !dir_emit(ctx, name_ptr, name_len, location.objectid,
5965 d_type);
5966
5967 if (name_ptr != tmp_name)
5968 kfree(name_ptr);
5969
5970 if (over)
5971 goto nopos;
5972 ctx->pos++;
5973 next:
5974 path->slots[0]++;
5975 }
5976
5977 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
5978 if (ret)
5979 goto nopos;
5980
5981 /*
5982 * Stop new entries from being returned after we return the last
5983 * entry.
5984 *
5985 * New directory entries are assigned a strictly increasing
5986 * offset. This means that new entries created during readdir
5987 * are *guaranteed* to be seen in the future by that readdir.
5988 * This has broken buggy programs which operate on names as
5989 * they're returned by readdir. Until we re-use freed offsets
5990 * we have this hack to stop new entries from being returned
5991 * under the assumption that they'll never reach this huge
5992 * offset.
5993 *
5994 * This is being careful not to overflow 32bit loff_t unless the
5995 * last entry requires it because doing so has broken 32bit apps
5996 * in the past.
5997 */
5998 if (ctx->pos >= INT_MAX)
5999 ctx->pos = LLONG_MAX;
6000 else
6001 ctx->pos = INT_MAX;
6002 nopos:
6003 ret = 0;
6004 err:
6005 if (put)
6006 btrfs_readdir_put_delayed_items(inode, &ins_list, &del_list);
6007 btrfs_free_path(path);
6008 return ret;
6009 }
6010
6011 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
6012 {
6013 struct btrfs_root *root = BTRFS_I(inode)->root;
6014 struct btrfs_trans_handle *trans;
6015 int ret = 0;
6016 bool nolock = false;
6017
6018 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
6019 return 0;
6020
6021 if (btrfs_fs_closing(root->fs_info) &&
6022 btrfs_is_free_space_inode(BTRFS_I(inode)))
6023 nolock = true;
6024
6025 if (wbc->sync_mode == WB_SYNC_ALL) {
6026 if (nolock)
6027 trans = btrfs_join_transaction_nolock(root);
6028 else
6029 trans = btrfs_join_transaction(root);
6030 if (IS_ERR(trans))
6031 return PTR_ERR(trans);
6032 ret = btrfs_commit_transaction(trans);
6033 }
6034 return ret;
6035 }
6036
6037 /*
6038 * This is somewhat expensive, updating the tree every time the
6039 * inode changes. But, it is most likely to find the inode in cache.
6040 * FIXME, needs more benchmarking...there are no reasons other than performance
6041 * to keep or drop this code.
6042 */
6043 static int btrfs_dirty_inode(struct inode *inode)
6044 {
6045 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6046 struct btrfs_root *root = BTRFS_I(inode)->root;
6047 struct btrfs_trans_handle *trans;
6048 int ret;
6049
6050 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
6051 return 0;
6052
6053 trans = btrfs_join_transaction(root);
6054 if (IS_ERR(trans))
6055 return PTR_ERR(trans);
6056
6057 ret = btrfs_update_inode(trans, root, inode);
6058 if (ret && ret == -ENOSPC) {
6059 /* whoops, lets try again with the full transaction */
6060 btrfs_end_transaction(trans);
6061 trans = btrfs_start_transaction(root, 1);
6062 if (IS_ERR(trans))
6063 return PTR_ERR(trans);
6064
6065 ret = btrfs_update_inode(trans, root, inode);
6066 }
6067 btrfs_end_transaction(trans);
6068 if (BTRFS_I(inode)->delayed_node)
6069 btrfs_balance_delayed_items(fs_info);
6070
6071 return ret;
6072 }
6073
6074 /*
6075 * This is a copy of file_update_time. We need this so we can return error on
6076 * ENOSPC for updating the inode in the case of file write and mmap writes.
6077 */
6078 static int btrfs_update_time(struct inode *inode, struct timespec *now,
6079 int flags)
6080 {
6081 struct btrfs_root *root = BTRFS_I(inode)->root;
6082
6083 if (btrfs_root_readonly(root))
6084 return -EROFS;
6085
6086 if (flags & S_VERSION)
6087 inode_inc_iversion(inode);
6088 if (flags & S_CTIME)
6089 inode->i_ctime = *now;
6090 if (flags & S_MTIME)
6091 inode->i_mtime = *now;
6092 if (flags & S_ATIME)
6093 inode->i_atime = *now;
6094 return btrfs_dirty_inode(inode);
6095 }
6096
6097 /*
6098 * find the highest existing sequence number in a directory
6099 * and then set the in-memory index_cnt variable to reflect
6100 * free sequence numbers
6101 */
6102 static int btrfs_set_inode_index_count(struct btrfs_inode *inode)
6103 {
6104 struct btrfs_root *root = inode->root;
6105 struct btrfs_key key, found_key;
6106 struct btrfs_path *path;
6107 struct extent_buffer *leaf;
6108 int ret;
6109
6110 key.objectid = btrfs_ino(inode);
6111 key.type = BTRFS_DIR_INDEX_KEY;
6112 key.offset = (u64)-1;
6113
6114 path = btrfs_alloc_path();
6115 if (!path)
6116 return -ENOMEM;
6117
6118 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6119 if (ret < 0)
6120 goto out;
6121 /* FIXME: we should be able to handle this */
6122 if (ret == 0)
6123 goto out;
6124 ret = 0;
6125
6126 /*
6127 * MAGIC NUMBER EXPLANATION:
6128 * since we search a directory based on f_pos we have to start at 2
6129 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
6130 * else has to start at 2
6131 */
6132 if (path->slots[0] == 0) {
6133 inode->index_cnt = 2;
6134 goto out;
6135 }
6136
6137 path->slots[0]--;
6138
6139 leaf = path->nodes[0];
6140 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6141
6142 if (found_key.objectid != btrfs_ino(inode) ||
6143 found_key.type != BTRFS_DIR_INDEX_KEY) {
6144 inode->index_cnt = 2;
6145 goto out;
6146 }
6147
6148 inode->index_cnt = found_key.offset + 1;
6149 out:
6150 btrfs_free_path(path);
6151 return ret;
6152 }
6153
6154 /*
6155 * helper to find a free sequence number in a given directory. This current
6156 * code is very simple, later versions will do smarter things in the btree
6157 */
6158 int btrfs_set_inode_index(struct btrfs_inode *dir, u64 *index)
6159 {
6160 int ret = 0;
6161
6162 if (dir->index_cnt == (u64)-1) {
6163 ret = btrfs_inode_delayed_dir_index_count(dir);
6164 if (ret) {
6165 ret = btrfs_set_inode_index_count(dir);
6166 if (ret)
6167 return ret;
6168 }
6169 }
6170
6171 *index = dir->index_cnt;
6172 dir->index_cnt++;
6173
6174 return ret;
6175 }
6176
6177 static int btrfs_insert_inode_locked(struct inode *inode)
6178 {
6179 struct btrfs_iget_args args;
6180 args.location = &BTRFS_I(inode)->location;
6181 args.root = BTRFS_I(inode)->root;
6182
6183 return insert_inode_locked4(inode,
6184 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
6185 btrfs_find_actor, &args);
6186 }
6187
6188 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
6189 struct btrfs_root *root,
6190 struct inode *dir,
6191 const char *name, int name_len,
6192 u64 ref_objectid, u64 objectid,
6193 umode_t mode, u64 *index)
6194 {
6195 struct btrfs_fs_info *fs_info = root->fs_info;
6196 struct inode *inode;
6197 struct btrfs_inode_item *inode_item;
6198 struct btrfs_key *location;
6199 struct btrfs_path *path;
6200 struct btrfs_inode_ref *ref;
6201 struct btrfs_key key[2];
6202 u32 sizes[2];
6203 int nitems = name ? 2 : 1;
6204 unsigned long ptr;
6205 int ret;
6206
6207 path = btrfs_alloc_path();
6208 if (!path)
6209 return ERR_PTR(-ENOMEM);
6210
6211 inode = new_inode(fs_info->sb);
6212 if (!inode) {
6213 btrfs_free_path(path);
6214 return ERR_PTR(-ENOMEM);
6215 }
6216
6217 /*
6218 * O_TMPFILE, set link count to 0, so that after this point,
6219 * we fill in an inode item with the correct link count.
6220 */
6221 if (!name)
6222 set_nlink(inode, 0);
6223
6224 /*
6225 * we have to initialize this early, so we can reclaim the inode
6226 * number if we fail afterwards in this function.
6227 */
6228 inode->i_ino = objectid;
6229
6230 if (dir && name) {
6231 trace_btrfs_inode_request(dir);
6232
6233 ret = btrfs_set_inode_index(BTRFS_I(dir), index);
6234 if (ret) {
6235 btrfs_free_path(path);
6236 iput(inode);
6237 return ERR_PTR(ret);
6238 }
6239 } else if (dir) {
6240 *index = 0;
6241 }
6242 /*
6243 * index_cnt is ignored for everything but a dir,
6244 * btrfs_get_inode_index_count has an explanation for the magic
6245 * number
6246 */
6247 BTRFS_I(inode)->index_cnt = 2;
6248 BTRFS_I(inode)->dir_index = *index;
6249 BTRFS_I(inode)->root = root;
6250 BTRFS_I(inode)->generation = trans->transid;
6251 inode->i_generation = BTRFS_I(inode)->generation;
6252
6253 /*
6254 * We could have gotten an inode number from somebody who was fsynced
6255 * and then removed in this same transaction, so let's just set full
6256 * sync since it will be a full sync anyway and this will blow away the
6257 * old info in the log.
6258 */
6259 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6260
6261 key[0].objectid = objectid;
6262 key[0].type = BTRFS_INODE_ITEM_KEY;
6263 key[0].offset = 0;
6264
6265 sizes[0] = sizeof(struct btrfs_inode_item);
6266
6267 if (name) {
6268 /*
6269 * Start new inodes with an inode_ref. This is slightly more
6270 * efficient for small numbers of hard links since they will
6271 * be packed into one item. Extended refs will kick in if we
6272 * add more hard links than can fit in the ref item.
6273 */
6274 key[1].objectid = objectid;
6275 key[1].type = BTRFS_INODE_REF_KEY;
6276 key[1].offset = ref_objectid;
6277
6278 sizes[1] = name_len + sizeof(*ref);
6279 }
6280
6281 location = &BTRFS_I(inode)->location;
6282 location->objectid = objectid;
6283 location->offset = 0;
6284 location->type = BTRFS_INODE_ITEM_KEY;
6285
6286 ret = btrfs_insert_inode_locked(inode);
6287 if (ret < 0)
6288 goto fail;
6289
6290 path->leave_spinning = 1;
6291 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6292 if (ret != 0)
6293 goto fail_unlock;
6294
6295 inode_init_owner(inode, dir, mode);
6296 inode_set_bytes(inode, 0);
6297
6298 inode->i_mtime = current_time(inode);
6299 inode->i_atime = inode->i_mtime;
6300 inode->i_ctime = inode->i_mtime;
6301 BTRFS_I(inode)->i_otime = inode->i_mtime;
6302
6303 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6304 struct btrfs_inode_item);
6305 memzero_extent_buffer(path->nodes[0], (unsigned long)inode_item,
6306 sizeof(*inode_item));
6307 fill_inode_item(trans, path->nodes[0], inode_item, inode);
6308
6309 if (name) {
6310 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6311 struct btrfs_inode_ref);
6312 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6313 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6314 ptr = (unsigned long)(ref + 1);
6315 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6316 }
6317
6318 btrfs_mark_buffer_dirty(path->nodes[0]);
6319 btrfs_free_path(path);
6320
6321 btrfs_inherit_iflags(inode, dir);
6322
6323 if (S_ISREG(mode)) {
6324 if (btrfs_test_opt(fs_info, NODATASUM))
6325 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6326 if (btrfs_test_opt(fs_info, NODATACOW))
6327 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6328 BTRFS_INODE_NODATASUM;
6329 }
6330
6331 inode_tree_add(inode);
6332
6333 trace_btrfs_inode_new(inode);
6334 btrfs_set_inode_last_trans(trans, inode);
6335
6336 btrfs_update_root_times(trans, root);
6337
6338 ret = btrfs_inode_inherit_props(trans, inode, dir);
6339 if (ret)
6340 btrfs_err(fs_info,
6341 "error inheriting props for ino %llu (root %llu): %d",
6342 btrfs_ino(BTRFS_I(inode)), root->root_key.objectid, ret);
6343
6344 return inode;
6345
6346 fail_unlock:
6347 unlock_new_inode(inode);
6348 fail:
6349 if (dir && name)
6350 BTRFS_I(dir)->index_cnt--;
6351 btrfs_free_path(path);
6352 iput(inode);
6353 return ERR_PTR(ret);
6354 }
6355
6356 static inline u8 btrfs_inode_type(struct inode *inode)
6357 {
6358 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
6359 }
6360
6361 /*
6362 * utility function to add 'inode' into 'parent_inode' with
6363 * a give name and a given sequence number.
6364 * if 'add_backref' is true, also insert a backref from the
6365 * inode to the parent directory.
6366 */
6367 int btrfs_add_link(struct btrfs_trans_handle *trans,
6368 struct btrfs_inode *parent_inode, struct btrfs_inode *inode,
6369 const char *name, int name_len, int add_backref, u64 index)
6370 {
6371 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
6372 int ret = 0;
6373 struct btrfs_key key;
6374 struct btrfs_root *root = parent_inode->root;
6375 u64 ino = btrfs_ino(inode);
6376 u64 parent_ino = btrfs_ino(parent_inode);
6377
6378 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6379 memcpy(&key, &inode->root->root_key, sizeof(key));
6380 } else {
6381 key.objectid = ino;
6382 key.type = BTRFS_INODE_ITEM_KEY;
6383 key.offset = 0;
6384 }
6385
6386 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6387 ret = btrfs_add_root_ref(trans, fs_info, key.objectid,
6388 root->root_key.objectid, parent_ino,
6389 index, name, name_len);
6390 } else if (add_backref) {
6391 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6392 parent_ino, index);
6393 }
6394
6395 /* Nothing to clean up yet */
6396 if (ret)
6397 return ret;
6398
6399 ret = btrfs_insert_dir_item(trans, root, name, name_len,
6400 parent_inode, &key,
6401 btrfs_inode_type(&inode->vfs_inode), index);
6402 if (ret == -EEXIST || ret == -EOVERFLOW)
6403 goto fail_dir_item;
6404 else if (ret) {
6405 btrfs_abort_transaction(trans, ret);
6406 return ret;
6407 }
6408
6409 btrfs_i_size_write(parent_inode, parent_inode->vfs_inode.i_size +
6410 name_len * 2);
6411 inode_inc_iversion(&parent_inode->vfs_inode);
6412 parent_inode->vfs_inode.i_mtime = parent_inode->vfs_inode.i_ctime =
6413 current_time(&parent_inode->vfs_inode);
6414 ret = btrfs_update_inode(trans, root, &parent_inode->vfs_inode);
6415 if (ret)
6416 btrfs_abort_transaction(trans, ret);
6417 return ret;
6418
6419 fail_dir_item:
6420 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6421 u64 local_index;
6422 int err;
6423 err = btrfs_del_root_ref(trans, fs_info, key.objectid,
6424 root->root_key.objectid, parent_ino,
6425 &local_index, name, name_len);
6426
6427 } else if (add_backref) {
6428 u64 local_index;
6429 int err;
6430
6431 err = btrfs_del_inode_ref(trans, root, name, name_len,
6432 ino, parent_ino, &local_index);
6433 }
6434 return ret;
6435 }
6436
6437 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6438 struct btrfs_inode *dir, struct dentry *dentry,
6439 struct btrfs_inode *inode, int backref, u64 index)
6440 {
6441 int err = btrfs_add_link(trans, dir, inode,
6442 dentry->d_name.name, dentry->d_name.len,
6443 backref, index);
6444 if (err > 0)
6445 err = -EEXIST;
6446 return err;
6447 }
6448
6449 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6450 umode_t mode, dev_t rdev)
6451 {
6452 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6453 struct btrfs_trans_handle *trans;
6454 struct btrfs_root *root = BTRFS_I(dir)->root;
6455 struct inode *inode = NULL;
6456 int err;
6457 int drop_inode = 0;
6458 u64 objectid;
6459 u64 index = 0;
6460
6461 /*
6462 * 2 for inode item and ref
6463 * 2 for dir items
6464 * 1 for xattr if selinux is on
6465 */
6466 trans = btrfs_start_transaction(root, 5);
6467 if (IS_ERR(trans))
6468 return PTR_ERR(trans);
6469
6470 err = btrfs_find_free_ino(root, &objectid);
6471 if (err)
6472 goto out_unlock;
6473
6474 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6475 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6476 mode, &index);
6477 if (IS_ERR(inode)) {
6478 err = PTR_ERR(inode);
6479 goto out_unlock;
6480 }
6481
6482 /*
6483 * If the active LSM wants to access the inode during
6484 * d_instantiate it needs these. Smack checks to see
6485 * if the filesystem supports xattrs by looking at the
6486 * ops vector.
6487 */
6488 inode->i_op = &btrfs_special_inode_operations;
6489 init_special_inode(inode, inode->i_mode, rdev);
6490
6491 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6492 if (err)
6493 goto out_unlock_inode;
6494
6495 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6496 0, index);
6497 if (err) {
6498 goto out_unlock_inode;
6499 } else {
6500 btrfs_update_inode(trans, root, inode);
6501 unlock_new_inode(inode);
6502 d_instantiate(dentry, inode);
6503 }
6504
6505 out_unlock:
6506 btrfs_end_transaction(trans);
6507 btrfs_balance_delayed_items(fs_info);
6508 btrfs_btree_balance_dirty(fs_info);
6509 if (drop_inode) {
6510 inode_dec_link_count(inode);
6511 iput(inode);
6512 }
6513 return err;
6514
6515 out_unlock_inode:
6516 drop_inode = 1;
6517 unlock_new_inode(inode);
6518 goto out_unlock;
6519
6520 }
6521
6522 static int btrfs_create(struct inode *dir, struct dentry *dentry,
6523 umode_t mode, bool excl)
6524 {
6525 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6526 struct btrfs_trans_handle *trans;
6527 struct btrfs_root *root = BTRFS_I(dir)->root;
6528 struct inode *inode = NULL;
6529 int drop_inode_on_err = 0;
6530 int err;
6531 u64 objectid;
6532 u64 index = 0;
6533
6534 /*
6535 * 2 for inode item and ref
6536 * 2 for dir items
6537 * 1 for xattr if selinux is on
6538 */
6539 trans = btrfs_start_transaction(root, 5);
6540 if (IS_ERR(trans))
6541 return PTR_ERR(trans);
6542
6543 err = btrfs_find_free_ino(root, &objectid);
6544 if (err)
6545 goto out_unlock;
6546
6547 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6548 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6549 mode, &index);
6550 if (IS_ERR(inode)) {
6551 err = PTR_ERR(inode);
6552 goto out_unlock;
6553 }
6554 drop_inode_on_err = 1;
6555 /*
6556 * If the active LSM wants to access the inode during
6557 * d_instantiate it needs these. Smack checks to see
6558 * if the filesystem supports xattrs by looking at the
6559 * ops vector.
6560 */
6561 inode->i_fop = &btrfs_file_operations;
6562 inode->i_op = &btrfs_file_inode_operations;
6563 inode->i_mapping->a_ops = &btrfs_aops;
6564
6565 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6566 if (err)
6567 goto out_unlock_inode;
6568
6569 err = btrfs_update_inode(trans, root, inode);
6570 if (err)
6571 goto out_unlock_inode;
6572
6573 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6574 0, index);
6575 if (err)
6576 goto out_unlock_inode;
6577
6578 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6579 unlock_new_inode(inode);
6580 d_instantiate(dentry, inode);
6581
6582 out_unlock:
6583 btrfs_end_transaction(trans);
6584 if (err && drop_inode_on_err) {
6585 inode_dec_link_count(inode);
6586 iput(inode);
6587 }
6588 btrfs_balance_delayed_items(fs_info);
6589 btrfs_btree_balance_dirty(fs_info);
6590 return err;
6591
6592 out_unlock_inode:
6593 unlock_new_inode(inode);
6594 goto out_unlock;
6595
6596 }
6597
6598 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6599 struct dentry *dentry)
6600 {
6601 struct btrfs_trans_handle *trans = NULL;
6602 struct btrfs_root *root = BTRFS_I(dir)->root;
6603 struct inode *inode = d_inode(old_dentry);
6604 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6605 u64 index;
6606 int err;
6607 int drop_inode = 0;
6608
6609 /* do not allow sys_link's with other subvols of the same device */
6610 if (root->objectid != BTRFS_I(inode)->root->objectid)
6611 return -EXDEV;
6612
6613 if (inode->i_nlink >= BTRFS_LINK_MAX)
6614 return -EMLINK;
6615
6616 err = btrfs_set_inode_index(BTRFS_I(dir), &index);
6617 if (err)
6618 goto fail;
6619
6620 /*
6621 * 2 items for inode and inode ref
6622 * 2 items for dir items
6623 * 1 item for parent inode
6624 */
6625 trans = btrfs_start_transaction(root, 5);
6626 if (IS_ERR(trans)) {
6627 err = PTR_ERR(trans);
6628 trans = NULL;
6629 goto fail;
6630 }
6631
6632 /* There are several dir indexes for this inode, clear the cache. */
6633 BTRFS_I(inode)->dir_index = 0ULL;
6634 inc_nlink(inode);
6635 inode_inc_iversion(inode);
6636 inode->i_ctime = current_time(inode);
6637 ihold(inode);
6638 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6639
6640 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6641 1, index);
6642
6643 if (err) {
6644 drop_inode = 1;
6645 } else {
6646 struct dentry *parent = dentry->d_parent;
6647 err = btrfs_update_inode(trans, root, inode);
6648 if (err)
6649 goto fail;
6650 if (inode->i_nlink == 1) {
6651 /*
6652 * If new hard link count is 1, it's a file created
6653 * with open(2) O_TMPFILE flag.
6654 */
6655 err = btrfs_orphan_del(trans, BTRFS_I(inode));
6656 if (err)
6657 goto fail;
6658 }
6659 d_instantiate(dentry, inode);
6660 btrfs_log_new_name(trans, BTRFS_I(inode), NULL, parent);
6661 }
6662
6663 btrfs_balance_delayed_items(fs_info);
6664 fail:
6665 if (trans)
6666 btrfs_end_transaction(trans);
6667 if (drop_inode) {
6668 inode_dec_link_count(inode);
6669 iput(inode);
6670 }
6671 btrfs_btree_balance_dirty(fs_info);
6672 return err;
6673 }
6674
6675 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6676 {
6677 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6678 struct inode *inode = NULL;
6679 struct btrfs_trans_handle *trans;
6680 struct btrfs_root *root = BTRFS_I(dir)->root;
6681 int err = 0;
6682 int drop_on_err = 0;
6683 u64 objectid = 0;
6684 u64 index = 0;
6685
6686 /*
6687 * 2 items for inode and ref
6688 * 2 items for dir items
6689 * 1 for xattr if selinux is on
6690 */
6691 trans = btrfs_start_transaction(root, 5);
6692 if (IS_ERR(trans))
6693 return PTR_ERR(trans);
6694
6695 err = btrfs_find_free_ino(root, &objectid);
6696 if (err)
6697 goto out_fail;
6698
6699 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6700 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6701 S_IFDIR | mode, &index);
6702 if (IS_ERR(inode)) {
6703 err = PTR_ERR(inode);
6704 goto out_fail;
6705 }
6706
6707 drop_on_err = 1;
6708 /* these must be set before we unlock the inode */
6709 inode->i_op = &btrfs_dir_inode_operations;
6710 inode->i_fop = &btrfs_dir_file_operations;
6711
6712 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6713 if (err)
6714 goto out_fail_inode;
6715
6716 btrfs_i_size_write(BTRFS_I(inode), 0);
6717 err = btrfs_update_inode(trans, root, inode);
6718 if (err)
6719 goto out_fail_inode;
6720
6721 err = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
6722 dentry->d_name.name,
6723 dentry->d_name.len, 0, index);
6724 if (err)
6725 goto out_fail_inode;
6726
6727 d_instantiate(dentry, inode);
6728 /*
6729 * mkdir is special. We're unlocking after we call d_instantiate
6730 * to avoid a race with nfsd calling d_instantiate.
6731 */
6732 unlock_new_inode(inode);
6733 drop_on_err = 0;
6734
6735 out_fail:
6736 btrfs_end_transaction(trans);
6737 if (drop_on_err) {
6738 inode_dec_link_count(inode);
6739 iput(inode);
6740 }
6741 btrfs_balance_delayed_items(fs_info);
6742 btrfs_btree_balance_dirty(fs_info);
6743 return err;
6744
6745 out_fail_inode:
6746 unlock_new_inode(inode);
6747 goto out_fail;
6748 }
6749
6750 /* Find next extent map of a given extent map, caller needs to ensure locks */
6751 static struct extent_map *next_extent_map(struct extent_map *em)
6752 {
6753 struct rb_node *next;
6754
6755 next = rb_next(&em->rb_node);
6756 if (!next)
6757 return NULL;
6758 return container_of(next, struct extent_map, rb_node);
6759 }
6760
6761 static struct extent_map *prev_extent_map(struct extent_map *em)
6762 {
6763 struct rb_node *prev;
6764
6765 prev = rb_prev(&em->rb_node);
6766 if (!prev)
6767 return NULL;
6768 return container_of(prev, struct extent_map, rb_node);
6769 }
6770
6771 /* helper for btfs_get_extent. Given an existing extent in the tree,
6772 * the existing extent is the nearest extent to map_start,
6773 * and an extent that you want to insert, deal with overlap and insert
6774 * the best fitted new extent into the tree.
6775 */
6776 static int merge_extent_mapping(struct extent_map_tree *em_tree,
6777 struct extent_map *existing,
6778 struct extent_map *em,
6779 u64 map_start)
6780 {
6781 struct extent_map *prev;
6782 struct extent_map *next;
6783 u64 start;
6784 u64 end;
6785 u64 start_diff;
6786
6787 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
6788
6789 if (existing->start > map_start) {
6790 next = existing;
6791 prev = prev_extent_map(next);
6792 } else {
6793 prev = existing;
6794 next = next_extent_map(prev);
6795 }
6796
6797 start = prev ? extent_map_end(prev) : em->start;
6798 start = max_t(u64, start, em->start);
6799 end = next ? next->start : extent_map_end(em);
6800 end = min_t(u64, end, extent_map_end(em));
6801 start_diff = start - em->start;
6802 em->start = start;
6803 em->len = end - start;
6804 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
6805 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
6806 em->block_start += start_diff;
6807 em->block_len -= start_diff;
6808 }
6809 return add_extent_mapping(em_tree, em, 0);
6810 }
6811
6812 static noinline int uncompress_inline(struct btrfs_path *path,
6813 struct page *page,
6814 size_t pg_offset, u64 extent_offset,
6815 struct btrfs_file_extent_item *item)
6816 {
6817 int ret;
6818 struct extent_buffer *leaf = path->nodes[0];
6819 char *tmp;
6820 size_t max_size;
6821 unsigned long inline_size;
6822 unsigned long ptr;
6823 int compress_type;
6824
6825 WARN_ON(pg_offset != 0);
6826 compress_type = btrfs_file_extent_compression(leaf, item);
6827 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6828 inline_size = btrfs_file_extent_inline_item_len(leaf,
6829 btrfs_item_nr(path->slots[0]));
6830 tmp = kmalloc(inline_size, GFP_NOFS);
6831 if (!tmp)
6832 return -ENOMEM;
6833 ptr = btrfs_file_extent_inline_start(item);
6834
6835 read_extent_buffer(leaf, tmp, ptr, inline_size);
6836
6837 max_size = min_t(unsigned long, PAGE_SIZE, max_size);
6838 ret = btrfs_decompress(compress_type, tmp, page,
6839 extent_offset, inline_size, max_size);
6840
6841 /*
6842 * decompression code contains a memset to fill in any space between the end
6843 * of the uncompressed data and the end of max_size in case the decompressed
6844 * data ends up shorter than ram_bytes. That doesn't cover the hole between
6845 * the end of an inline extent and the beginning of the next block, so we
6846 * cover that region here.
6847 */
6848
6849 if (max_size + pg_offset < PAGE_SIZE) {
6850 char *map = kmap(page);
6851 memset(map + pg_offset + max_size, 0, PAGE_SIZE - max_size - pg_offset);
6852 kunmap(page);
6853 }
6854 kfree(tmp);
6855 return ret;
6856 }
6857
6858 /*
6859 * a bit scary, this does extent mapping from logical file offset to the disk.
6860 * the ugly parts come from merging extents from the disk with the in-ram
6861 * representation. This gets more complex because of the data=ordered code,
6862 * where the in-ram extents might be locked pending data=ordered completion.
6863 *
6864 * This also copies inline extents directly into the page.
6865 */
6866 struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
6867 struct page *page,
6868 size_t pg_offset, u64 start, u64 len,
6869 int create)
6870 {
6871 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
6872 int ret;
6873 int err = 0;
6874 u64 extent_start = 0;
6875 u64 extent_end = 0;
6876 u64 objectid = btrfs_ino(inode);
6877 u32 found_type;
6878 struct btrfs_path *path = NULL;
6879 struct btrfs_root *root = inode->root;
6880 struct btrfs_file_extent_item *item;
6881 struct extent_buffer *leaf;
6882 struct btrfs_key found_key;
6883 struct extent_map *em = NULL;
6884 struct extent_map_tree *em_tree = &inode->extent_tree;
6885 struct extent_io_tree *io_tree = &inode->io_tree;
6886 struct btrfs_trans_handle *trans = NULL;
6887 const bool new_inline = !page || create;
6888
6889 again:
6890 read_lock(&em_tree->lock);
6891 em = lookup_extent_mapping(em_tree, start, len);
6892 if (em)
6893 em->bdev = fs_info->fs_devices->latest_bdev;
6894 read_unlock(&em_tree->lock);
6895
6896 if (em) {
6897 if (em->start > start || em->start + em->len <= start)
6898 free_extent_map(em);
6899 else if (em->block_start == EXTENT_MAP_INLINE && page)
6900 free_extent_map(em);
6901 else
6902 goto out;
6903 }
6904 em = alloc_extent_map();
6905 if (!em) {
6906 err = -ENOMEM;
6907 goto out;
6908 }
6909 em->bdev = fs_info->fs_devices->latest_bdev;
6910 em->start = EXTENT_MAP_HOLE;
6911 em->orig_start = EXTENT_MAP_HOLE;
6912 em->len = (u64)-1;
6913 em->block_len = (u64)-1;
6914
6915 if (!path) {
6916 path = btrfs_alloc_path();
6917 if (!path) {
6918 err = -ENOMEM;
6919 goto out;
6920 }
6921 /*
6922 * Chances are we'll be called again, so go ahead and do
6923 * readahead
6924 */
6925 path->reada = READA_FORWARD;
6926 }
6927
6928 ret = btrfs_lookup_file_extent(trans, root, path,
6929 objectid, start, trans != NULL);
6930 if (ret < 0) {
6931 err = ret;
6932 goto out;
6933 }
6934
6935 if (ret != 0) {
6936 if (path->slots[0] == 0)
6937 goto not_found;
6938 path->slots[0]--;
6939 }
6940
6941 leaf = path->nodes[0];
6942 item = btrfs_item_ptr(leaf, path->slots[0],
6943 struct btrfs_file_extent_item);
6944 /* are we inside the extent that was found? */
6945 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6946 found_type = found_key.type;
6947 if (found_key.objectid != objectid ||
6948 found_type != BTRFS_EXTENT_DATA_KEY) {
6949 /*
6950 * If we backup past the first extent we want to move forward
6951 * and see if there is an extent in front of us, otherwise we'll
6952 * say there is a hole for our whole search range which can
6953 * cause problems.
6954 */
6955 extent_end = start;
6956 goto next;
6957 }
6958
6959 found_type = btrfs_file_extent_type(leaf, item);
6960 extent_start = found_key.offset;
6961 if (found_type == BTRFS_FILE_EXTENT_REG ||
6962 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6963 extent_end = extent_start +
6964 btrfs_file_extent_num_bytes(leaf, item);
6965
6966 trace_btrfs_get_extent_show_fi_regular(inode, leaf, item,
6967 extent_start);
6968 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6969 size_t size;
6970 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6971 extent_end = ALIGN(extent_start + size,
6972 fs_info->sectorsize);
6973
6974 trace_btrfs_get_extent_show_fi_inline(inode, leaf, item,
6975 path->slots[0],
6976 extent_start);
6977 }
6978 next:
6979 if (start >= extent_end) {
6980 path->slots[0]++;
6981 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6982 ret = btrfs_next_leaf(root, path);
6983 if (ret < 0) {
6984 err = ret;
6985 goto out;
6986 }
6987 if (ret > 0)
6988 goto not_found;
6989 leaf = path->nodes[0];
6990 }
6991 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6992 if (found_key.objectid != objectid ||
6993 found_key.type != BTRFS_EXTENT_DATA_KEY)
6994 goto not_found;
6995 if (start + len <= found_key.offset)
6996 goto not_found;
6997 if (start > found_key.offset)
6998 goto next;
6999 em->start = start;
7000 em->orig_start = start;
7001 em->len = found_key.offset - start;
7002 goto not_found_em;
7003 }
7004
7005 btrfs_extent_item_to_extent_map(inode, path, item,
7006 new_inline, em);
7007
7008 if (found_type == BTRFS_FILE_EXTENT_REG ||
7009 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7010 goto insert;
7011 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
7012 unsigned long ptr;
7013 char *map;
7014 size_t size;
7015 size_t extent_offset;
7016 size_t copy_size;
7017
7018 if (new_inline)
7019 goto out;
7020
7021 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
7022 extent_offset = page_offset(page) + pg_offset - extent_start;
7023 copy_size = min_t(u64, PAGE_SIZE - pg_offset,
7024 size - extent_offset);
7025 em->start = extent_start + extent_offset;
7026 em->len = ALIGN(copy_size, fs_info->sectorsize);
7027 em->orig_block_len = em->len;
7028 em->orig_start = em->start;
7029 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
7030 if (create == 0 && !PageUptodate(page)) {
7031 if (btrfs_file_extent_compression(leaf, item) !=
7032 BTRFS_COMPRESS_NONE) {
7033 ret = uncompress_inline(path, page, pg_offset,
7034 extent_offset, item);
7035 if (ret) {
7036 err = ret;
7037 goto out;
7038 }
7039 } else {
7040 map = kmap(page);
7041 read_extent_buffer(leaf, map + pg_offset, ptr,
7042 copy_size);
7043 if (pg_offset + copy_size < PAGE_SIZE) {
7044 memset(map + pg_offset + copy_size, 0,
7045 PAGE_SIZE - pg_offset -
7046 copy_size);
7047 }
7048 kunmap(page);
7049 }
7050 flush_dcache_page(page);
7051 } else if (create && PageUptodate(page)) {
7052 BUG();
7053 if (!trans) {
7054 kunmap(page);
7055 free_extent_map(em);
7056 em = NULL;
7057
7058 btrfs_release_path(path);
7059 trans = btrfs_join_transaction(root);
7060
7061 if (IS_ERR(trans))
7062 return ERR_CAST(trans);
7063 goto again;
7064 }
7065 map = kmap(page);
7066 write_extent_buffer(leaf, map + pg_offset, ptr,
7067 copy_size);
7068 kunmap(page);
7069 btrfs_mark_buffer_dirty(leaf);
7070 }
7071 set_extent_uptodate(io_tree, em->start,
7072 extent_map_end(em) - 1, NULL, GFP_NOFS);
7073 goto insert;
7074 }
7075 not_found:
7076 em->start = start;
7077 em->orig_start = start;
7078 em->len = len;
7079 not_found_em:
7080 em->block_start = EXTENT_MAP_HOLE;
7081 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
7082 insert:
7083 btrfs_release_path(path);
7084 if (em->start > start || extent_map_end(em) <= start) {
7085 btrfs_err(fs_info,
7086 "bad extent! em: [%llu %llu] passed [%llu %llu]",
7087 em->start, em->len, start, len);
7088 err = -EIO;
7089 goto out;
7090 }
7091
7092 err = 0;
7093 write_lock(&em_tree->lock);
7094 ret = add_extent_mapping(em_tree, em, 0);
7095 /* it is possible that someone inserted the extent into the tree
7096 * while we had the lock dropped. It is also possible that
7097 * an overlapping map exists in the tree
7098 */
7099 if (ret == -EEXIST) {
7100 struct extent_map *existing;
7101
7102 ret = 0;
7103
7104 existing = search_extent_mapping(em_tree, start, len);
7105 /*
7106 * existing will always be non-NULL, since there must be
7107 * extent causing the -EEXIST.
7108 */
7109 if (existing->start == em->start &&
7110 extent_map_end(existing) >= extent_map_end(em) &&
7111 em->block_start == existing->block_start) {
7112 /*
7113 * The existing extent map already encompasses the
7114 * entire extent map we tried to add.
7115 */
7116 free_extent_map(em);
7117 em = existing;
7118 err = 0;
7119
7120 } else if (start >= extent_map_end(existing) ||
7121 start <= existing->start) {
7122 /*
7123 * The existing extent map is the one nearest to
7124 * the [start, start + len) range which overlaps
7125 */
7126 err = merge_extent_mapping(em_tree, existing,
7127 em, start);
7128 free_extent_map(existing);
7129 if (err) {
7130 free_extent_map(em);
7131 em = NULL;
7132 }
7133 } else {
7134 free_extent_map(em);
7135 em = existing;
7136 err = 0;
7137 }
7138 }
7139 write_unlock(&em_tree->lock);
7140 out:
7141
7142 trace_btrfs_get_extent(root, inode, em);
7143
7144 btrfs_free_path(path);
7145 if (trans) {
7146 ret = btrfs_end_transaction(trans);
7147 if (!err)
7148 err = ret;
7149 }
7150 if (err) {
7151 free_extent_map(em);
7152 return ERR_PTR(err);
7153 }
7154 BUG_ON(!em); /* Error is always set */
7155 return em;
7156 }
7157
7158 struct extent_map *btrfs_get_extent_fiemap(struct btrfs_inode *inode,
7159 struct page *page,
7160 size_t pg_offset, u64 start, u64 len,
7161 int create)
7162 {
7163 struct extent_map *em;
7164 struct extent_map *hole_em = NULL;
7165 u64 range_start = start;
7166 u64 end;
7167 u64 found;
7168 u64 found_end;
7169 int err = 0;
7170
7171 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
7172 if (IS_ERR(em))
7173 return em;
7174 /*
7175 * If our em maps to:
7176 * - a hole or
7177 * - a pre-alloc extent,
7178 * there might actually be delalloc bytes behind it.
7179 */
7180 if (em->block_start != EXTENT_MAP_HOLE &&
7181 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7182 return em;
7183 else
7184 hole_em = em;
7185
7186 /* check to see if we've wrapped (len == -1 or similar) */
7187 end = start + len;
7188 if (end < start)
7189 end = (u64)-1;
7190 else
7191 end -= 1;
7192
7193 em = NULL;
7194
7195 /* ok, we didn't find anything, lets look for delalloc */
7196 found = count_range_bits(&inode->io_tree, &range_start,
7197 end, len, EXTENT_DELALLOC, 1);
7198 found_end = range_start + found;
7199 if (found_end < range_start)
7200 found_end = (u64)-1;
7201
7202 /*
7203 * we didn't find anything useful, return
7204 * the original results from get_extent()
7205 */
7206 if (range_start > end || found_end <= start) {
7207 em = hole_em;
7208 hole_em = NULL;
7209 goto out;
7210 }
7211
7212 /* adjust the range_start to make sure it doesn't
7213 * go backwards from the start they passed in
7214 */
7215 range_start = max(start, range_start);
7216 found = found_end - range_start;
7217
7218 if (found > 0) {
7219 u64 hole_start = start;
7220 u64 hole_len = len;
7221
7222 em = alloc_extent_map();
7223 if (!em) {
7224 err = -ENOMEM;
7225 goto out;
7226 }
7227 /*
7228 * when btrfs_get_extent can't find anything it
7229 * returns one huge hole
7230 *
7231 * make sure what it found really fits our range, and
7232 * adjust to make sure it is based on the start from
7233 * the caller
7234 */
7235 if (hole_em) {
7236 u64 calc_end = extent_map_end(hole_em);
7237
7238 if (calc_end <= start || (hole_em->start > end)) {
7239 free_extent_map(hole_em);
7240 hole_em = NULL;
7241 } else {
7242 hole_start = max(hole_em->start, start);
7243 hole_len = calc_end - hole_start;
7244 }
7245 }
7246 em->bdev = NULL;
7247 if (hole_em && range_start > hole_start) {
7248 /* our hole starts before our delalloc, so we
7249 * have to return just the parts of the hole
7250 * that go until the delalloc starts
7251 */
7252 em->len = min(hole_len,
7253 range_start - hole_start);
7254 em->start = hole_start;
7255 em->orig_start = hole_start;
7256 /*
7257 * don't adjust block start at all,
7258 * it is fixed at EXTENT_MAP_HOLE
7259 */
7260 em->block_start = hole_em->block_start;
7261 em->block_len = hole_len;
7262 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
7263 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7264 } else {
7265 em->start = range_start;
7266 em->len = found;
7267 em->orig_start = range_start;
7268 em->block_start = EXTENT_MAP_DELALLOC;
7269 em->block_len = found;
7270 }
7271 } else if (hole_em) {
7272 return hole_em;
7273 }
7274 out:
7275
7276 free_extent_map(hole_em);
7277 if (err) {
7278 free_extent_map(em);
7279 return ERR_PTR(err);
7280 }
7281 return em;
7282 }
7283
7284 static struct extent_map *btrfs_create_dio_extent(struct inode *inode,
7285 const u64 start,
7286 const u64 len,
7287 const u64 orig_start,
7288 const u64 block_start,
7289 const u64 block_len,
7290 const u64 orig_block_len,
7291 const u64 ram_bytes,
7292 const int type)
7293 {
7294 struct extent_map *em = NULL;
7295 int ret;
7296
7297 if (type != BTRFS_ORDERED_NOCOW) {
7298 em = create_io_em(inode, start, len, orig_start,
7299 block_start, block_len, orig_block_len,
7300 ram_bytes,
7301 BTRFS_COMPRESS_NONE, /* compress_type */
7302 type);
7303 if (IS_ERR(em))
7304 goto out;
7305 }
7306 ret = btrfs_add_ordered_extent_dio(inode, start, block_start,
7307 len, block_len, type);
7308 if (ret) {
7309 if (em) {
7310 free_extent_map(em);
7311 btrfs_drop_extent_cache(BTRFS_I(inode), start,
7312 start + len - 1, 0);
7313 }
7314 em = ERR_PTR(ret);
7315 }
7316 out:
7317
7318 return em;
7319 }
7320
7321 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7322 u64 start, u64 len)
7323 {
7324 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7325 struct btrfs_root *root = BTRFS_I(inode)->root;
7326 struct extent_map *em;
7327 struct btrfs_key ins;
7328 u64 alloc_hint;
7329 int ret;
7330
7331 alloc_hint = get_extent_allocation_hint(inode, start, len);
7332 ret = btrfs_reserve_extent(root, len, len, fs_info->sectorsize,
7333 0, alloc_hint, &ins, 1, 1);
7334 if (ret)
7335 return ERR_PTR(ret);
7336
7337 em = btrfs_create_dio_extent(inode, start, ins.offset, start,
7338 ins.objectid, ins.offset, ins.offset,
7339 ins.offset, BTRFS_ORDERED_REGULAR);
7340 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
7341 if (IS_ERR(em))
7342 btrfs_free_reserved_extent(fs_info, ins.objectid,
7343 ins.offset, 1);
7344
7345 return em;
7346 }
7347
7348 /*
7349 * returns 1 when the nocow is safe, < 1 on error, 0 if the
7350 * block must be cow'd
7351 */
7352 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7353 u64 *orig_start, u64 *orig_block_len,
7354 u64 *ram_bytes)
7355 {
7356 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7357 struct btrfs_path *path;
7358 int ret;
7359 struct extent_buffer *leaf;
7360 struct btrfs_root *root = BTRFS_I(inode)->root;
7361 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7362 struct btrfs_file_extent_item *fi;
7363 struct btrfs_key key;
7364 u64 disk_bytenr;
7365 u64 backref_offset;
7366 u64 extent_end;
7367 u64 num_bytes;
7368 int slot;
7369 int found_type;
7370 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7371
7372 path = btrfs_alloc_path();
7373 if (!path)
7374 return -ENOMEM;
7375
7376 ret = btrfs_lookup_file_extent(NULL, root, path,
7377 btrfs_ino(BTRFS_I(inode)), offset, 0);
7378 if (ret < 0)
7379 goto out;
7380
7381 slot = path->slots[0];
7382 if (ret == 1) {
7383 if (slot == 0) {
7384 /* can't find the item, must cow */
7385 ret = 0;
7386 goto out;
7387 }
7388 slot--;
7389 }
7390 ret = 0;
7391 leaf = path->nodes[0];
7392 btrfs_item_key_to_cpu(leaf, &key, slot);
7393 if (key.objectid != btrfs_ino(BTRFS_I(inode)) ||
7394 key.type != BTRFS_EXTENT_DATA_KEY) {
7395 /* not our file or wrong item type, must cow */
7396 goto out;
7397 }
7398
7399 if (key.offset > offset) {
7400 /* Wrong offset, must cow */
7401 goto out;
7402 }
7403
7404 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7405 found_type = btrfs_file_extent_type(leaf, fi);
7406 if (found_type != BTRFS_FILE_EXTENT_REG &&
7407 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7408 /* not a regular extent, must cow */
7409 goto out;
7410 }
7411
7412 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7413 goto out;
7414
7415 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7416 if (extent_end <= offset)
7417 goto out;
7418
7419 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7420 if (disk_bytenr == 0)
7421 goto out;
7422
7423 if (btrfs_file_extent_compression(leaf, fi) ||
7424 btrfs_file_extent_encryption(leaf, fi) ||
7425 btrfs_file_extent_other_encoding(leaf, fi))
7426 goto out;
7427
7428 backref_offset = btrfs_file_extent_offset(leaf, fi);
7429
7430 if (orig_start) {
7431 *orig_start = key.offset - backref_offset;
7432 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7433 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7434 }
7435
7436 if (btrfs_extent_readonly(fs_info, disk_bytenr))
7437 goto out;
7438
7439 num_bytes = min(offset + *len, extent_end) - offset;
7440 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7441 u64 range_end;
7442
7443 range_end = round_up(offset + num_bytes,
7444 root->fs_info->sectorsize) - 1;
7445 ret = test_range_bit(io_tree, offset, range_end,
7446 EXTENT_DELALLOC, 0, NULL);
7447 if (ret) {
7448 ret = -EAGAIN;
7449 goto out;
7450 }
7451 }
7452
7453 btrfs_release_path(path);
7454
7455 /*
7456 * look for other files referencing this extent, if we
7457 * find any we must cow
7458 */
7459
7460 ret = btrfs_cross_ref_exist(root, btrfs_ino(BTRFS_I(inode)),
7461 key.offset - backref_offset, disk_bytenr);
7462 if (ret) {
7463 ret = 0;
7464 goto out;
7465 }
7466
7467 /*
7468 * adjust disk_bytenr and num_bytes to cover just the bytes
7469 * in this extent we are about to write. If there
7470 * are any csums in that range we have to cow in order
7471 * to keep the csums correct
7472 */
7473 disk_bytenr += backref_offset;
7474 disk_bytenr += offset - key.offset;
7475 if (csum_exist_in_range(fs_info, disk_bytenr, num_bytes))
7476 goto out;
7477 /*
7478 * all of the above have passed, it is safe to overwrite this extent
7479 * without cow
7480 */
7481 *len = num_bytes;
7482 ret = 1;
7483 out:
7484 btrfs_free_path(path);
7485 return ret;
7486 }
7487
7488 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
7489 {
7490 struct radix_tree_root *root = &inode->i_mapping->page_tree;
7491 bool found = false;
7492 void **pagep = NULL;
7493 struct page *page = NULL;
7494 unsigned long start_idx;
7495 unsigned long end_idx;
7496
7497 start_idx = start >> PAGE_SHIFT;
7498
7499 /*
7500 * end is the last byte in the last page. end == start is legal
7501 */
7502 end_idx = end >> PAGE_SHIFT;
7503
7504 rcu_read_lock();
7505
7506 /* Most of the code in this while loop is lifted from
7507 * find_get_page. It's been modified to begin searching from a
7508 * page and return just the first page found in that range. If the
7509 * found idx is less than or equal to the end idx then we know that
7510 * a page exists. If no pages are found or if those pages are
7511 * outside of the range then we're fine (yay!) */
7512 while (page == NULL &&
7513 radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
7514 page = radix_tree_deref_slot(pagep);
7515 if (unlikely(!page))
7516 break;
7517
7518 if (radix_tree_exception(page)) {
7519 if (radix_tree_deref_retry(page)) {
7520 page = NULL;
7521 continue;
7522 }
7523 /*
7524 * Otherwise, shmem/tmpfs must be storing a swap entry
7525 * here as an exceptional entry: so return it without
7526 * attempting to raise page count.
7527 */
7528 page = NULL;
7529 break; /* TODO: Is this relevant for this use case? */
7530 }
7531
7532 if (!page_cache_get_speculative(page)) {
7533 page = NULL;
7534 continue;
7535 }
7536
7537 /*
7538 * Has the page moved?
7539 * This is part of the lockless pagecache protocol. See
7540 * include/linux/pagemap.h for details.
7541 */
7542 if (unlikely(page != *pagep)) {
7543 put_page(page);
7544 page = NULL;
7545 }
7546 }
7547
7548 if (page) {
7549 if (page->index <= end_idx)
7550 found = true;
7551 put_page(page);
7552 }
7553
7554 rcu_read_unlock();
7555 return found;
7556 }
7557
7558 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7559 struct extent_state **cached_state, int writing)
7560 {
7561 struct btrfs_ordered_extent *ordered;
7562 int ret = 0;
7563
7564 while (1) {
7565 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7566 cached_state);
7567 /*
7568 * We're concerned with the entire range that we're going to be
7569 * doing DIO to, so we need to make sure there's no ordered
7570 * extents in this range.
7571 */
7572 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), lockstart,
7573 lockend - lockstart + 1);
7574
7575 /*
7576 * We need to make sure there are no buffered pages in this
7577 * range either, we could have raced between the invalidate in
7578 * generic_file_direct_write and locking the extent. The
7579 * invalidate needs to happen so that reads after a write do not
7580 * get stale data.
7581 */
7582 if (!ordered &&
7583 (!writing ||
7584 !btrfs_page_exists_in_range(inode, lockstart, lockend)))
7585 break;
7586
7587 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7588 cached_state, GFP_NOFS);
7589
7590 if (ordered) {
7591 /*
7592 * If we are doing a DIO read and the ordered extent we
7593 * found is for a buffered write, we can not wait for it
7594 * to complete and retry, because if we do so we can
7595 * deadlock with concurrent buffered writes on page
7596 * locks. This happens only if our DIO read covers more
7597 * than one extent map, if at this point has already
7598 * created an ordered extent for a previous extent map
7599 * and locked its range in the inode's io tree, and a
7600 * concurrent write against that previous extent map's
7601 * range and this range started (we unlock the ranges
7602 * in the io tree only when the bios complete and
7603 * buffered writes always lock pages before attempting
7604 * to lock range in the io tree).
7605 */
7606 if (writing ||
7607 test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags))
7608 btrfs_start_ordered_extent(inode, ordered, 1);
7609 else
7610 ret = -ENOTBLK;
7611 btrfs_put_ordered_extent(ordered);
7612 } else {
7613 /*
7614 * We could trigger writeback for this range (and wait
7615 * for it to complete) and then invalidate the pages for
7616 * this range (through invalidate_inode_pages2_range()),
7617 * but that can lead us to a deadlock with a concurrent
7618 * call to readpages() (a buffered read or a defrag call
7619 * triggered a readahead) on a page lock due to an
7620 * ordered dio extent we created before but did not have
7621 * yet a corresponding bio submitted (whence it can not
7622 * complete), which makes readpages() wait for that
7623 * ordered extent to complete while holding a lock on
7624 * that page.
7625 */
7626 ret = -ENOTBLK;
7627 }
7628
7629 if (ret)
7630 break;
7631
7632 cond_resched();
7633 }
7634
7635 return ret;
7636 }
7637
7638 /* The callers of this must take lock_extent() */
7639 static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
7640 u64 orig_start, u64 block_start,
7641 u64 block_len, u64 orig_block_len,
7642 u64 ram_bytes, int compress_type,
7643 int type)
7644 {
7645 struct extent_map_tree *em_tree;
7646 struct extent_map *em;
7647 struct btrfs_root *root = BTRFS_I(inode)->root;
7648 int ret;
7649
7650 ASSERT(type == BTRFS_ORDERED_PREALLOC ||
7651 type == BTRFS_ORDERED_COMPRESSED ||
7652 type == BTRFS_ORDERED_NOCOW ||
7653 type == BTRFS_ORDERED_REGULAR);
7654
7655 em_tree = &BTRFS_I(inode)->extent_tree;
7656 em = alloc_extent_map();
7657 if (!em)
7658 return ERR_PTR(-ENOMEM);
7659
7660 em->start = start;
7661 em->orig_start = orig_start;
7662 em->len = len;
7663 em->block_len = block_len;
7664 em->block_start = block_start;
7665 em->bdev = root->fs_info->fs_devices->latest_bdev;
7666 em->orig_block_len = orig_block_len;
7667 em->ram_bytes = ram_bytes;
7668 em->generation = -1;
7669 set_bit(EXTENT_FLAG_PINNED, &em->flags);
7670 if (type == BTRFS_ORDERED_PREALLOC) {
7671 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7672 } else if (type == BTRFS_ORDERED_COMPRESSED) {
7673 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
7674 em->compress_type = compress_type;
7675 }
7676
7677 do {
7678 btrfs_drop_extent_cache(BTRFS_I(inode), em->start,
7679 em->start + em->len - 1, 0);
7680 write_lock(&em_tree->lock);
7681 ret = add_extent_mapping(em_tree, em, 1);
7682 write_unlock(&em_tree->lock);
7683 /*
7684 * The caller has taken lock_extent(), who could race with us
7685 * to add em?
7686 */
7687 } while (ret == -EEXIST);
7688
7689 if (ret) {
7690 free_extent_map(em);
7691 return ERR_PTR(ret);
7692 }
7693
7694 /* em got 2 refs now, callers needs to do free_extent_map once. */
7695 return em;
7696 }
7697
7698 static void adjust_dio_outstanding_extents(struct inode *inode,
7699 struct btrfs_dio_data *dio_data,
7700 const u64 len)
7701 {
7702 unsigned num_extents = count_max_extents(len);
7703
7704 /*
7705 * If we have an outstanding_extents count still set then we're
7706 * within our reservation, otherwise we need to adjust our inode
7707 * counter appropriately.
7708 */
7709 if (dio_data->outstanding_extents >= num_extents) {
7710 dio_data->outstanding_extents -= num_extents;
7711 } else {
7712 /*
7713 * If dio write length has been split due to no large enough
7714 * contiguous space, we need to compensate our inode counter
7715 * appropriately.
7716 */
7717 u64 num_needed = num_extents - dio_data->outstanding_extents;
7718
7719 spin_lock(&BTRFS_I(inode)->lock);
7720 BTRFS_I(inode)->outstanding_extents += num_needed;
7721 spin_unlock(&BTRFS_I(inode)->lock);
7722 }
7723 }
7724
7725 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7726 struct buffer_head *bh_result, int create)
7727 {
7728 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7729 struct extent_map *em;
7730 struct extent_state *cached_state = NULL;
7731 struct btrfs_dio_data *dio_data = NULL;
7732 u64 start = iblock << inode->i_blkbits;
7733 u64 lockstart, lockend;
7734 u64 len = bh_result->b_size;
7735 int unlock_bits = EXTENT_LOCKED;
7736 int ret = 0;
7737
7738 if (create)
7739 unlock_bits |= EXTENT_DIRTY;
7740 else
7741 len = min_t(u64, len, fs_info->sectorsize);
7742
7743 lockstart = start;
7744 lockend = start + len - 1;
7745
7746 if (current->journal_info) {
7747 /*
7748 * Need to pull our outstanding extents and set journal_info to NULL so
7749 * that anything that needs to check if there's a transaction doesn't get
7750 * confused.
7751 */
7752 dio_data = current->journal_info;
7753 current->journal_info = NULL;
7754 }
7755
7756 /*
7757 * If this errors out it's because we couldn't invalidate pagecache for
7758 * this range and we need to fallback to buffered.
7759 */
7760 if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
7761 create)) {
7762 ret = -ENOTBLK;
7763 goto err;
7764 }
7765
7766 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
7767 if (IS_ERR(em)) {
7768 ret = PTR_ERR(em);
7769 goto unlock_err;
7770 }
7771
7772 /*
7773 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7774 * io. INLINE is special, and we could probably kludge it in here, but
7775 * it's still buffered so for safety lets just fall back to the generic
7776 * buffered path.
7777 *
7778 * For COMPRESSED we _have_ to read the entire extent in so we can
7779 * decompress it, so there will be buffering required no matter what we
7780 * do, so go ahead and fallback to buffered.
7781 *
7782 * We return -ENOTBLK because that's what makes DIO go ahead and go back
7783 * to buffered IO. Don't blame me, this is the price we pay for using
7784 * the generic code.
7785 */
7786 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7787 em->block_start == EXTENT_MAP_INLINE) {
7788 free_extent_map(em);
7789 ret = -ENOTBLK;
7790 goto unlock_err;
7791 }
7792
7793 /* Just a good old fashioned hole, return */
7794 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
7795 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
7796 free_extent_map(em);
7797 goto unlock_err;
7798 }
7799
7800 /*
7801 * We don't allocate a new extent in the following cases
7802 *
7803 * 1) The inode is marked as NODATACOW. In this case we'll just use the
7804 * existing extent.
7805 * 2) The extent is marked as PREALLOC. We're good to go here and can
7806 * just use the extent.
7807 *
7808 */
7809 if (!create) {
7810 len = min(len, em->len - (start - em->start));
7811 lockstart = start + len;
7812 goto unlock;
7813 }
7814
7815 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7816 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7817 em->block_start != EXTENT_MAP_HOLE)) {
7818 int type;
7819 u64 block_start, orig_start, orig_block_len, ram_bytes;
7820
7821 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7822 type = BTRFS_ORDERED_PREALLOC;
7823 else
7824 type = BTRFS_ORDERED_NOCOW;
7825 len = min(len, em->len - (start - em->start));
7826 block_start = em->block_start + (start - em->start);
7827
7828 if (can_nocow_extent(inode, start, &len, &orig_start,
7829 &orig_block_len, &ram_bytes) == 1 &&
7830 btrfs_inc_nocow_writers(fs_info, block_start)) {
7831 struct extent_map *em2;
7832
7833 em2 = btrfs_create_dio_extent(inode, start, len,
7834 orig_start, block_start,
7835 len, orig_block_len,
7836 ram_bytes, type);
7837 btrfs_dec_nocow_writers(fs_info, block_start);
7838 if (type == BTRFS_ORDERED_PREALLOC) {
7839 free_extent_map(em);
7840 em = em2;
7841 }
7842 if (em2 && IS_ERR(em2)) {
7843 ret = PTR_ERR(em2);
7844 goto unlock_err;
7845 }
7846 /*
7847 * For inode marked NODATACOW or extent marked PREALLOC,
7848 * use the existing or preallocated extent, so does not
7849 * need to adjust btrfs_space_info's bytes_may_use.
7850 */
7851 btrfs_free_reserved_data_space_noquota(inode,
7852 start, len);
7853 goto unlock;
7854 }
7855 }
7856
7857 /*
7858 * this will cow the extent, reset the len in case we changed
7859 * it above
7860 */
7861 len = bh_result->b_size;
7862 free_extent_map(em);
7863 em = btrfs_new_extent_direct(inode, start, len);
7864 if (IS_ERR(em)) {
7865 ret = PTR_ERR(em);
7866 goto unlock_err;
7867 }
7868 len = min(len, em->len - (start - em->start));
7869 unlock:
7870 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7871 inode->i_blkbits;
7872 bh_result->b_size = len;
7873 bh_result->b_bdev = em->bdev;
7874 set_buffer_mapped(bh_result);
7875 if (create) {
7876 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7877 set_buffer_new(bh_result);
7878
7879 /*
7880 * Need to update the i_size under the extent lock so buffered
7881 * readers will get the updated i_size when we unlock.
7882 */
7883 if (!dio_data->overwrite && start + len > i_size_read(inode))
7884 i_size_write(inode, start + len);
7885
7886 adjust_dio_outstanding_extents(inode, dio_data, len);
7887 WARN_ON(dio_data->reserve < len);
7888 dio_data->reserve -= len;
7889 dio_data->unsubmitted_oe_range_end = start + len;
7890 current->journal_info = dio_data;
7891 }
7892
7893 /*
7894 * In the case of write we need to clear and unlock the entire range,
7895 * in the case of read we need to unlock only the end area that we
7896 * aren't using if there is any left over space.
7897 */
7898 if (lockstart < lockend) {
7899 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7900 lockend, unlock_bits, 1, 0,
7901 &cached_state, GFP_NOFS);
7902 } else {
7903 free_extent_state(cached_state);
7904 }
7905
7906 free_extent_map(em);
7907
7908 return 0;
7909
7910 unlock_err:
7911 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7912 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
7913 err:
7914 if (dio_data)
7915 current->journal_info = dio_data;
7916 /*
7917 * Compensate the delalloc release we do in btrfs_direct_IO() when we
7918 * write less data then expected, so that we don't underflow our inode's
7919 * outstanding extents counter.
7920 */
7921 if (create && dio_data)
7922 adjust_dio_outstanding_extents(inode, dio_data, len);
7923
7924 return ret;
7925 }
7926
7927 static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio,
7928 int mirror_num)
7929 {
7930 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7931 int ret;
7932
7933 BUG_ON(bio_op(bio) == REQ_OP_WRITE);
7934
7935 bio_get(bio);
7936
7937 ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DIO_REPAIR);
7938 if (ret)
7939 goto err;
7940
7941 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
7942 err:
7943 bio_put(bio);
7944 return ret;
7945 }
7946
7947 static int btrfs_check_dio_repairable(struct inode *inode,
7948 struct bio *failed_bio,
7949 struct io_failure_record *failrec,
7950 int failed_mirror)
7951 {
7952 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7953 int num_copies;
7954
7955 num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len);
7956 if (num_copies == 1) {
7957 /*
7958 * we only have a single copy of the data, so don't bother with
7959 * all the retry and error correction code that follows. no
7960 * matter what the error is, it is very likely to persist.
7961 */
7962 btrfs_debug(fs_info,
7963 "Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
7964 num_copies, failrec->this_mirror, failed_mirror);
7965 return 0;
7966 }
7967
7968 failrec->failed_mirror = failed_mirror;
7969 failrec->this_mirror++;
7970 if (failrec->this_mirror == failed_mirror)
7971 failrec->this_mirror++;
7972
7973 if (failrec->this_mirror > num_copies) {
7974 btrfs_debug(fs_info,
7975 "Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
7976 num_copies, failrec->this_mirror, failed_mirror);
7977 return 0;
7978 }
7979
7980 return 1;
7981 }
7982
7983 static int dio_read_error(struct inode *inode, struct bio *failed_bio,
7984 struct page *page, unsigned int pgoff,
7985 u64 start, u64 end, int failed_mirror,
7986 bio_end_io_t *repair_endio, void *repair_arg)
7987 {
7988 struct io_failure_record *failrec;
7989 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7990 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
7991 struct bio *bio;
7992 int isector;
7993 int read_mode = 0;
7994 int segs;
7995 int ret;
7996
7997 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
7998
7999 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
8000 if (ret)
8001 return ret;
8002
8003 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
8004 failed_mirror);
8005 if (!ret) {
8006 free_io_failure(failure_tree, io_tree, failrec);
8007 return -EIO;
8008 }
8009
8010 segs = bio_segments(failed_bio);
8011 if (segs > 1 ||
8012 (failed_bio->bi_io_vec->bv_len > btrfs_inode_sectorsize(inode)))
8013 read_mode |= REQ_FAILFAST_DEV;
8014
8015 isector = start - btrfs_io_bio(failed_bio)->logical;
8016 isector >>= inode->i_sb->s_blocksize_bits;
8017 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
8018 pgoff, isector, repair_endio, repair_arg);
8019 bio_set_op_attrs(bio, REQ_OP_READ, read_mode);
8020
8021 btrfs_debug(BTRFS_I(inode)->root->fs_info,
8022 "Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n",
8023 read_mode, failrec->this_mirror, failrec->in_validation);
8024
8025 ret = submit_dio_repair_bio(inode, bio, failrec->this_mirror);
8026 if (ret) {
8027 free_io_failure(failure_tree, io_tree, failrec);
8028 bio_put(bio);
8029 }
8030
8031 return ret;
8032 }
8033
8034 struct btrfs_retry_complete {
8035 struct completion done;
8036 struct inode *inode;
8037 u64 start;
8038 int uptodate;
8039 };
8040
8041 static void btrfs_retry_endio_nocsum(struct bio *bio)
8042 {
8043 struct btrfs_retry_complete *done = bio->bi_private;
8044 struct inode *inode = done->inode;
8045 struct bio_vec *bvec;
8046 struct extent_io_tree *io_tree, *failure_tree;
8047 int i;
8048
8049 if (bio->bi_status)
8050 goto end;
8051
8052 ASSERT(bio->bi_vcnt == 1);
8053 io_tree = &BTRFS_I(inode)->io_tree;
8054 failure_tree = &BTRFS_I(inode)->io_failure_tree;
8055 ASSERT(bio->bi_io_vec->bv_len == btrfs_inode_sectorsize(inode));
8056
8057 done->uptodate = 1;
8058 ASSERT(!bio_flagged(bio, BIO_CLONED));
8059 bio_for_each_segment_all(bvec, bio, i)
8060 clean_io_failure(BTRFS_I(inode)->root->fs_info, failure_tree,
8061 io_tree, done->start, bvec->bv_page,
8062 btrfs_ino(BTRFS_I(inode)), 0);
8063 end:
8064 complete(&done->done);
8065 bio_put(bio);
8066 }
8067
8068 static int __btrfs_correct_data_nocsum(struct inode *inode,
8069 struct btrfs_io_bio *io_bio)
8070 {
8071 struct btrfs_fs_info *fs_info;
8072 struct bio_vec bvec;
8073 struct bvec_iter iter;
8074 struct btrfs_retry_complete done;
8075 u64 start;
8076 unsigned int pgoff;
8077 u32 sectorsize;
8078 int nr_sectors;
8079 int ret;
8080 int err = 0;
8081
8082 fs_info = BTRFS_I(inode)->root->fs_info;
8083 sectorsize = fs_info->sectorsize;
8084
8085 start = io_bio->logical;
8086 done.inode = inode;
8087 io_bio->bio.bi_iter = io_bio->iter;
8088
8089 bio_for_each_segment(bvec, &io_bio->bio, iter) {
8090 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
8091 pgoff = bvec.bv_offset;
8092
8093 next_block_or_try_again:
8094 done.uptodate = 0;
8095 done.start = start;
8096 init_completion(&done.done);
8097
8098 ret = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
8099 pgoff, start, start + sectorsize - 1,
8100 io_bio->mirror_num,
8101 btrfs_retry_endio_nocsum, &done);
8102 if (ret) {
8103 err = ret;
8104 goto next;
8105 }
8106
8107 wait_for_completion(&done.done);
8108
8109 if (!done.uptodate) {
8110 /* We might have another mirror, so try again */
8111 goto next_block_or_try_again;
8112 }
8113
8114 next:
8115 start += sectorsize;
8116
8117 nr_sectors--;
8118 if (nr_sectors) {
8119 pgoff += sectorsize;
8120 ASSERT(pgoff < PAGE_SIZE);
8121 goto next_block_or_try_again;
8122 }
8123 }
8124
8125 return err;
8126 }
8127
8128 static void btrfs_retry_endio(struct bio *bio)
8129 {
8130 struct btrfs_retry_complete *done = bio->bi_private;
8131 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8132 struct extent_io_tree *io_tree, *failure_tree;
8133 struct inode *inode = done->inode;
8134 struct bio_vec *bvec;
8135 int uptodate;
8136 int ret;
8137 int i;
8138
8139 if (bio->bi_status)
8140 goto end;
8141
8142 uptodate = 1;
8143
8144 ASSERT(bio->bi_vcnt == 1);
8145 ASSERT(bio->bi_io_vec->bv_len == btrfs_inode_sectorsize(done->inode));
8146
8147 io_tree = &BTRFS_I(inode)->io_tree;
8148 failure_tree = &BTRFS_I(inode)->io_failure_tree;
8149
8150 ASSERT(!bio_flagged(bio, BIO_CLONED));
8151 bio_for_each_segment_all(bvec, bio, i) {
8152 ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page,
8153 bvec->bv_offset, done->start,
8154 bvec->bv_len);
8155 if (!ret)
8156 clean_io_failure(BTRFS_I(inode)->root->fs_info,
8157 failure_tree, io_tree, done->start,
8158 bvec->bv_page,
8159 btrfs_ino(BTRFS_I(inode)),
8160 bvec->bv_offset);
8161 else
8162 uptodate = 0;
8163 }
8164
8165 done->uptodate = uptodate;
8166 end:
8167 complete(&done->done);
8168 bio_put(bio);
8169 }
8170
8171 static blk_status_t __btrfs_subio_endio_read(struct inode *inode,
8172 struct btrfs_io_bio *io_bio, blk_status_t err)
8173 {
8174 struct btrfs_fs_info *fs_info;
8175 struct bio_vec bvec;
8176 struct bvec_iter iter;
8177 struct btrfs_retry_complete done;
8178 u64 start;
8179 u64 offset = 0;
8180 u32 sectorsize;
8181 int nr_sectors;
8182 unsigned int pgoff;
8183 int csum_pos;
8184 bool uptodate = (err == 0);
8185 int ret;
8186
8187 fs_info = BTRFS_I(inode)->root->fs_info;
8188 sectorsize = fs_info->sectorsize;
8189
8190 err = 0;
8191 start = io_bio->logical;
8192 done.inode = inode;
8193 io_bio->bio.bi_iter = io_bio->iter;
8194
8195 bio_for_each_segment(bvec, &io_bio->bio, iter) {
8196 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
8197
8198 pgoff = bvec.bv_offset;
8199 next_block:
8200 if (uptodate) {
8201 csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset);
8202 ret = __readpage_endio_check(inode, io_bio, csum_pos,
8203 bvec.bv_page, pgoff, start, sectorsize);
8204 if (likely(!ret))
8205 goto next;
8206 }
8207 try_again:
8208 done.uptodate = 0;
8209 done.start = start;
8210 init_completion(&done.done);
8211
8212 ret = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
8213 pgoff, start, start + sectorsize - 1,
8214 io_bio->mirror_num,
8215 btrfs_retry_endio, &done);
8216 if (ret) {
8217 err = errno_to_blk_status(ret);
8218 goto next;
8219 }
8220
8221 wait_for_completion(&done.done);
8222
8223 if (!done.uptodate) {
8224 /* We might have another mirror, so try again */
8225 goto try_again;
8226 }
8227 next:
8228 offset += sectorsize;
8229 start += sectorsize;
8230
8231 ASSERT(nr_sectors);
8232
8233 nr_sectors--;
8234 if (nr_sectors) {
8235 pgoff += sectorsize;
8236 ASSERT(pgoff < PAGE_SIZE);
8237 goto next_block;
8238 }
8239 }
8240
8241 return err;
8242 }
8243
8244 static blk_status_t btrfs_subio_endio_read(struct inode *inode,
8245 struct btrfs_io_bio *io_bio, blk_status_t err)
8246 {
8247 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8248
8249 if (skip_csum) {
8250 if (unlikely(err))
8251 return __btrfs_correct_data_nocsum(inode, io_bio);
8252 else
8253 return 0;
8254 } else {
8255 return __btrfs_subio_endio_read(inode, io_bio, err);
8256 }
8257 }
8258
8259 static void btrfs_endio_direct_read(struct bio *bio)
8260 {
8261 struct btrfs_dio_private *dip = bio->bi_private;
8262 struct inode *inode = dip->inode;
8263 struct bio *dio_bio;
8264 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8265 blk_status_t err = bio->bi_status;
8266
8267 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED) {
8268 err = btrfs_subio_endio_read(inode, io_bio, err);
8269 if (!err)
8270 bio->bi_status = 0;
8271 }
8272
8273 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
8274 dip->logical_offset + dip->bytes - 1);
8275 dio_bio = dip->dio_bio;
8276
8277 kfree(dip);
8278
8279 dio_bio->bi_status = bio->bi_status;
8280 dio_end_io(dio_bio);
8281
8282 if (io_bio->end_io)
8283 io_bio->end_io(io_bio, blk_status_to_errno(err));
8284 bio_put(bio);
8285 }
8286
8287 static void __endio_write_update_ordered(struct inode *inode,
8288 const u64 offset, const u64 bytes,
8289 const bool uptodate)
8290 {
8291 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8292 struct btrfs_ordered_extent *ordered = NULL;
8293 struct btrfs_workqueue *wq;
8294 btrfs_work_func_t func;
8295 u64 ordered_offset = offset;
8296 u64 ordered_bytes = bytes;
8297 int ret;
8298
8299 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
8300 wq = fs_info->endio_freespace_worker;
8301 func = btrfs_freespace_write_helper;
8302 } else {
8303 wq = fs_info->endio_write_workers;
8304 func = btrfs_endio_write_helper;
8305 }
8306
8307 again:
8308 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
8309 &ordered_offset,
8310 ordered_bytes,
8311 uptodate);
8312 if (!ret)
8313 goto out_test;
8314
8315 btrfs_init_work(&ordered->work, func, finish_ordered_fn, NULL, NULL);
8316 btrfs_queue_work(wq, &ordered->work);
8317 out_test:
8318 /*
8319 * our bio might span multiple ordered extents. If we haven't
8320 * completed the accounting for the whole dio, go back and try again
8321 */
8322 if (ordered_offset < offset + bytes) {
8323 ordered_bytes = offset + bytes - ordered_offset;
8324 ordered = NULL;
8325 goto again;
8326 }
8327 }
8328
8329 static void btrfs_endio_direct_write(struct bio *bio)
8330 {
8331 struct btrfs_dio_private *dip = bio->bi_private;
8332 struct bio *dio_bio = dip->dio_bio;
8333
8334 __endio_write_update_ordered(dip->inode, dip->logical_offset,
8335 dip->bytes, !bio->bi_status);
8336
8337 kfree(dip);
8338
8339 dio_bio->bi_status = bio->bi_status;
8340 dio_end_io(dio_bio);
8341 bio_put(bio);
8342 }
8343
8344 static blk_status_t __btrfs_submit_bio_start_direct_io(void *private_data,
8345 struct bio *bio, int mirror_num,
8346 unsigned long bio_flags, u64 offset)
8347 {
8348 struct inode *inode = private_data;
8349 blk_status_t ret;
8350 ret = btrfs_csum_one_bio(inode, bio, offset, 1);
8351 BUG_ON(ret); /* -ENOMEM */
8352 return 0;
8353 }
8354
8355 static void btrfs_end_dio_bio(struct bio *bio)
8356 {
8357 struct btrfs_dio_private *dip = bio->bi_private;
8358 blk_status_t err = bio->bi_status;
8359
8360 if (err)
8361 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
8362 "direct IO failed ino %llu rw %d,%u sector %#Lx len %u err no %d",
8363 btrfs_ino(BTRFS_I(dip->inode)), bio_op(bio),
8364 bio->bi_opf,
8365 (unsigned long long)bio->bi_iter.bi_sector,
8366 bio->bi_iter.bi_size, err);
8367
8368 if (dip->subio_endio)
8369 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
8370
8371 if (err) {
8372 dip->errors = 1;
8373
8374 /*
8375 * before atomic variable goto zero, we must make sure
8376 * dip->errors is perceived to be set.
8377 */
8378 smp_mb__before_atomic();
8379 }
8380
8381 /* if there are more bios still pending for this dio, just exit */
8382 if (!atomic_dec_and_test(&dip->pending_bios))
8383 goto out;
8384
8385 if (dip->errors) {
8386 bio_io_error(dip->orig_bio);
8387 } else {
8388 dip->dio_bio->bi_status = 0;
8389 bio_endio(dip->orig_bio);
8390 }
8391 out:
8392 bio_put(bio);
8393 }
8394
8395 static inline blk_status_t btrfs_lookup_and_bind_dio_csum(struct inode *inode,
8396 struct btrfs_dio_private *dip,
8397 struct bio *bio,
8398 u64 file_offset)
8399 {
8400 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8401 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
8402 blk_status_t ret;
8403
8404 /*
8405 * We load all the csum data we need when we submit
8406 * the first bio to reduce the csum tree search and
8407 * contention.
8408 */
8409 if (dip->logical_offset == file_offset) {
8410 ret = btrfs_lookup_bio_sums_dio(inode, dip->orig_bio,
8411 file_offset);
8412 if (ret)
8413 return ret;
8414 }
8415
8416 if (bio == dip->orig_bio)
8417 return 0;
8418
8419 file_offset -= dip->logical_offset;
8420 file_offset >>= inode->i_sb->s_blocksize_bits;
8421 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
8422
8423 return 0;
8424 }
8425
8426 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
8427 u64 file_offset, int skip_sum,
8428 int async_submit)
8429 {
8430 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8431 struct btrfs_dio_private *dip = bio->bi_private;
8432 bool write = bio_op(bio) == REQ_OP_WRITE;
8433 blk_status_t ret;
8434
8435 if (async_submit)
8436 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
8437
8438 bio_get(bio);
8439
8440 if (!write) {
8441 ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA);
8442 if (ret)
8443 goto err;
8444 }
8445
8446 if (skip_sum)
8447 goto map;
8448
8449 if (write && async_submit) {
8450 ret = btrfs_wq_submit_bio(fs_info, bio, 0, 0,
8451 file_offset, inode,
8452 __btrfs_submit_bio_start_direct_io,
8453 __btrfs_submit_bio_done);
8454 goto err;
8455 } else if (write) {
8456 /*
8457 * If we aren't doing async submit, calculate the csum of the
8458 * bio now.
8459 */
8460 ret = btrfs_csum_one_bio(inode, bio, file_offset, 1);
8461 if (ret)
8462 goto err;
8463 } else {
8464 ret = btrfs_lookup_and_bind_dio_csum(inode, dip, bio,
8465 file_offset);
8466 if (ret)
8467 goto err;
8468 }
8469 map:
8470 ret = btrfs_map_bio(fs_info, bio, 0, async_submit);
8471 err:
8472 bio_put(bio);
8473 return ret;
8474 }
8475
8476 static int btrfs_submit_direct_hook(struct btrfs_dio_private *dip,
8477 int skip_sum)
8478 {
8479 struct inode *inode = dip->inode;
8480 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8481 struct bio *bio;
8482 struct bio *orig_bio = dip->orig_bio;
8483 u64 start_sector = orig_bio->bi_iter.bi_sector;
8484 u64 file_offset = dip->logical_offset;
8485 u64 map_length;
8486 int async_submit = 0;
8487 u64 submit_len;
8488 int clone_offset = 0;
8489 int clone_len;
8490 int ret;
8491
8492 map_length = orig_bio->bi_iter.bi_size;
8493 submit_len = map_length;
8494 ret = btrfs_map_block(fs_info, btrfs_op(orig_bio), start_sector << 9,
8495 &map_length, NULL, 0);
8496 if (ret)
8497 return -EIO;
8498
8499 if (map_length >= submit_len) {
8500 bio = orig_bio;
8501 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8502 goto submit;
8503 }
8504
8505 /* async crcs make it difficult to collect full stripe writes. */
8506 if (btrfs_data_alloc_profile(fs_info) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8507 async_submit = 0;
8508 else
8509 async_submit = 1;
8510
8511 /* bio split */
8512 ASSERT(map_length <= INT_MAX);
8513 atomic_inc(&dip->pending_bios);
8514 do {
8515 clone_len = min_t(int, submit_len, map_length);
8516
8517 /*
8518 * This will never fail as it's passing GPF_NOFS and
8519 * the allocation is backed by btrfs_bioset.
8520 */
8521 bio = btrfs_bio_clone_partial(orig_bio, clone_offset,
8522 clone_len);
8523 bio->bi_private = dip;
8524 bio->bi_end_io = btrfs_end_dio_bio;
8525 btrfs_io_bio(bio)->logical = file_offset;
8526
8527 ASSERT(submit_len >= clone_len);
8528 submit_len -= clone_len;
8529 if (submit_len == 0)
8530 break;
8531
8532 /*
8533 * Increase the count before we submit the bio so we know
8534 * the end IO handler won't happen before we increase the
8535 * count. Otherwise, the dip might get freed before we're
8536 * done setting it up.
8537 */
8538 atomic_inc(&dip->pending_bios);
8539
8540 ret = __btrfs_submit_dio_bio(bio, inode, file_offset, skip_sum,
8541 async_submit);
8542 if (ret) {
8543 bio_put(bio);
8544 atomic_dec(&dip->pending_bios);
8545 goto out_err;
8546 }
8547
8548 clone_offset += clone_len;
8549 start_sector += clone_len >> 9;
8550 file_offset += clone_len;
8551
8552 map_length = submit_len;
8553 ret = btrfs_map_block(fs_info, btrfs_op(orig_bio),
8554 start_sector << 9, &map_length, NULL, 0);
8555 if (ret)
8556 goto out_err;
8557 } while (submit_len > 0);
8558
8559 submit:
8560 ret = __btrfs_submit_dio_bio(bio, inode, file_offset, skip_sum,
8561 async_submit);
8562 if (!ret)
8563 return 0;
8564
8565 bio_put(bio);
8566 out_err:
8567 dip->errors = 1;
8568 /*
8569 * before atomic variable goto zero, we must
8570 * make sure dip->errors is perceived to be set.
8571 */
8572 smp_mb__before_atomic();
8573 if (atomic_dec_and_test(&dip->pending_bios))
8574 bio_io_error(dip->orig_bio);
8575
8576 /* bio_end_io() will handle error, so we needn't return it */
8577 return 0;
8578 }
8579
8580 static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode,
8581 loff_t file_offset)
8582 {
8583 struct btrfs_dio_private *dip = NULL;
8584 struct bio *bio = NULL;
8585 struct btrfs_io_bio *io_bio;
8586 int skip_sum;
8587 bool write = (bio_op(dio_bio) == REQ_OP_WRITE);
8588 int ret = 0;
8589
8590 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8591
8592 bio = btrfs_bio_clone(dio_bio);
8593
8594 dip = kzalloc(sizeof(*dip), GFP_NOFS);
8595 if (!dip) {
8596 ret = -ENOMEM;
8597 goto free_ordered;
8598 }
8599
8600 dip->private = dio_bio->bi_private;
8601 dip->inode = inode;
8602 dip->logical_offset = file_offset;
8603 dip->bytes = dio_bio->bi_iter.bi_size;
8604 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8605 bio->bi_private = dip;
8606 dip->orig_bio = bio;
8607 dip->dio_bio = dio_bio;
8608 atomic_set(&dip->pending_bios, 0);
8609 io_bio = btrfs_io_bio(bio);
8610 io_bio->logical = file_offset;
8611
8612 if (write) {
8613 bio->bi_end_io = btrfs_endio_direct_write;
8614 } else {
8615 bio->bi_end_io = btrfs_endio_direct_read;
8616 dip->subio_endio = btrfs_subio_endio_read;
8617 }
8618
8619 /*
8620 * Reset the range for unsubmitted ordered extents (to a 0 length range)
8621 * even if we fail to submit a bio, because in such case we do the
8622 * corresponding error handling below and it must not be done a second
8623 * time by btrfs_direct_IO().
8624 */
8625 if (write) {
8626 struct btrfs_dio_data *dio_data = current->journal_info;
8627
8628 dio_data->unsubmitted_oe_range_end = dip->logical_offset +
8629 dip->bytes;
8630 dio_data->unsubmitted_oe_range_start =
8631 dio_data->unsubmitted_oe_range_end;
8632 }
8633
8634 ret = btrfs_submit_direct_hook(dip, skip_sum);
8635 if (!ret)
8636 return;
8637
8638 if (io_bio->end_io)
8639 io_bio->end_io(io_bio, ret);
8640
8641 free_ordered:
8642 /*
8643 * If we arrived here it means either we failed to submit the dip
8644 * or we either failed to clone the dio_bio or failed to allocate the
8645 * dip. If we cloned the dio_bio and allocated the dip, we can just
8646 * call bio_endio against our io_bio so that we get proper resource
8647 * cleanup if we fail to submit the dip, otherwise, we must do the
8648 * same as btrfs_endio_direct_[write|read] because we can't call these
8649 * callbacks - they require an allocated dip and a clone of dio_bio.
8650 */
8651 if (bio && dip) {
8652 bio_io_error(bio);
8653 /*
8654 * The end io callbacks free our dip, do the final put on bio
8655 * and all the cleanup and final put for dio_bio (through
8656 * dio_end_io()).
8657 */
8658 dip = NULL;
8659 bio = NULL;
8660 } else {
8661 if (write)
8662 __endio_write_update_ordered(inode,
8663 file_offset,
8664 dio_bio->bi_iter.bi_size,
8665 false);
8666 else
8667 unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
8668 file_offset + dio_bio->bi_iter.bi_size - 1);
8669
8670 dio_bio->bi_status = BLK_STS_IOERR;
8671 /*
8672 * Releases and cleans up our dio_bio, no need to bio_put()
8673 * nor bio_endio()/bio_io_error() against dio_bio.
8674 */
8675 dio_end_io(dio_bio);
8676 }
8677 if (bio)
8678 bio_put(bio);
8679 kfree(dip);
8680 }
8681
8682 static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info,
8683 struct kiocb *iocb,
8684 const struct iov_iter *iter, loff_t offset)
8685 {
8686 int seg;
8687 int i;
8688 unsigned int blocksize_mask = fs_info->sectorsize - 1;
8689 ssize_t retval = -EINVAL;
8690
8691 if (offset & blocksize_mask)
8692 goto out;
8693
8694 if (iov_iter_alignment(iter) & blocksize_mask)
8695 goto out;
8696
8697 /* If this is a write we don't need to check anymore */
8698 if (iov_iter_rw(iter) != READ || !iter_is_iovec(iter))
8699 return 0;
8700 /*
8701 * Check to make sure we don't have duplicate iov_base's in this
8702 * iovec, if so return EINVAL, otherwise we'll get csum errors
8703 * when reading back.
8704 */
8705 for (seg = 0; seg < iter->nr_segs; seg++) {
8706 for (i = seg + 1; i < iter->nr_segs; i++) {
8707 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8708 goto out;
8709 }
8710 }
8711 retval = 0;
8712 out:
8713 return retval;
8714 }
8715
8716 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
8717 {
8718 struct file *file = iocb->ki_filp;
8719 struct inode *inode = file->f_mapping->host;
8720 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8721 struct btrfs_dio_data dio_data = { 0 };
8722 struct extent_changeset *data_reserved = NULL;
8723 loff_t offset = iocb->ki_pos;
8724 size_t count = 0;
8725 int flags = 0;
8726 bool wakeup = true;
8727 bool relock = false;
8728 ssize_t ret;
8729
8730 if (check_direct_IO(fs_info, iocb, iter, offset))
8731 return 0;
8732
8733 inode_dio_begin(inode);
8734 smp_mb__after_atomic();
8735
8736 /*
8737 * The generic stuff only does filemap_write_and_wait_range, which
8738 * isn't enough if we've written compressed pages to this area, so
8739 * we need to flush the dirty pages again to make absolutely sure
8740 * that any outstanding dirty pages are on disk.
8741 */
8742 count = iov_iter_count(iter);
8743 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8744 &BTRFS_I(inode)->runtime_flags))
8745 filemap_fdatawrite_range(inode->i_mapping, offset,
8746 offset + count - 1);
8747
8748 if (iov_iter_rw(iter) == WRITE) {
8749 /*
8750 * If the write DIO is beyond the EOF, we need update
8751 * the isize, but it is protected by i_mutex. So we can
8752 * not unlock the i_mutex at this case.
8753 */
8754 if (offset + count <= inode->i_size) {
8755 dio_data.overwrite = 1;
8756 inode_unlock(inode);
8757 relock = true;
8758 } else if (iocb->ki_flags & IOCB_NOWAIT) {
8759 ret = -EAGAIN;
8760 goto out;
8761 }
8762 ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
8763 offset, count);
8764 if (ret)
8765 goto out;
8766 dio_data.outstanding_extents = count_max_extents(count);
8767
8768 /*
8769 * We need to know how many extents we reserved so that we can
8770 * do the accounting properly if we go over the number we
8771 * originally calculated. Abuse current->journal_info for this.
8772 */
8773 dio_data.reserve = round_up(count,
8774 fs_info->sectorsize);
8775 dio_data.unsubmitted_oe_range_start = (u64)offset;
8776 dio_data.unsubmitted_oe_range_end = (u64)offset;
8777 current->journal_info = &dio_data;
8778 down_read(&BTRFS_I(inode)->dio_sem);
8779 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8780 &BTRFS_I(inode)->runtime_flags)) {
8781 inode_dio_end(inode);
8782 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8783 wakeup = false;
8784 }
8785
8786 ret = __blockdev_direct_IO(iocb, inode,
8787 fs_info->fs_devices->latest_bdev,
8788 iter, btrfs_get_blocks_direct, NULL,
8789 btrfs_submit_direct, flags);
8790 if (iov_iter_rw(iter) == WRITE) {
8791 up_read(&BTRFS_I(inode)->dio_sem);
8792 current->journal_info = NULL;
8793 if (ret < 0 && ret != -EIOCBQUEUED) {
8794 if (dio_data.reserve)
8795 btrfs_delalloc_release_space(inode, data_reserved,
8796 offset, dio_data.reserve);
8797 /*
8798 * On error we might have left some ordered extents
8799 * without submitting corresponding bios for them, so
8800 * cleanup them up to avoid other tasks getting them
8801 * and waiting for them to complete forever.
8802 */
8803 if (dio_data.unsubmitted_oe_range_start <
8804 dio_data.unsubmitted_oe_range_end)
8805 __endio_write_update_ordered(inode,
8806 dio_data.unsubmitted_oe_range_start,
8807 dio_data.unsubmitted_oe_range_end -
8808 dio_data.unsubmitted_oe_range_start,
8809 false);
8810 } else if (ret >= 0 && (size_t)ret < count)
8811 btrfs_delalloc_release_space(inode, data_reserved,
8812 offset, count - (size_t)ret);
8813 }
8814 out:
8815 if (wakeup)
8816 inode_dio_end(inode);
8817 if (relock)
8818 inode_lock(inode);
8819
8820 extent_changeset_free(data_reserved);
8821 return ret;
8822 }
8823
8824 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
8825
8826 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8827 __u64 start, __u64 len)
8828 {
8829 int ret;
8830
8831 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8832 if (ret)
8833 return ret;
8834
8835 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
8836 }
8837
8838 int btrfs_readpage(struct file *file, struct page *page)
8839 {
8840 struct extent_io_tree *tree;
8841 tree = &BTRFS_I(page->mapping->host)->io_tree;
8842 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8843 }
8844
8845 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8846 {
8847 struct extent_io_tree *tree;
8848 struct inode *inode = page->mapping->host;
8849 int ret;
8850
8851 if (current->flags & PF_MEMALLOC) {
8852 redirty_page_for_writepage(wbc, page);
8853 unlock_page(page);
8854 return 0;
8855 }
8856
8857 /*
8858 * If we are under memory pressure we will call this directly from the
8859 * VM, we need to make sure we have the inode referenced for the ordered
8860 * extent. If not just return like we didn't do anything.
8861 */
8862 if (!igrab(inode)) {
8863 redirty_page_for_writepage(wbc, page);
8864 return AOP_WRITEPAGE_ACTIVATE;
8865 }
8866 tree = &BTRFS_I(page->mapping->host)->io_tree;
8867 ret = extent_write_full_page(tree, page, btrfs_get_extent, wbc);
8868 btrfs_add_delayed_iput(inode);
8869 return ret;
8870 }
8871
8872 static int btrfs_writepages(struct address_space *mapping,
8873 struct writeback_control *wbc)
8874 {
8875 struct extent_io_tree *tree;
8876
8877 tree = &BTRFS_I(mapping->host)->io_tree;
8878 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
8879 }
8880
8881 static int
8882 btrfs_readpages(struct file *file, struct address_space *mapping,
8883 struct list_head *pages, unsigned nr_pages)
8884 {
8885 struct extent_io_tree *tree;
8886 tree = &BTRFS_I(mapping->host)->io_tree;
8887 return extent_readpages(tree, mapping, pages, nr_pages,
8888 btrfs_get_extent);
8889 }
8890 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8891 {
8892 struct extent_io_tree *tree;
8893 struct extent_map_tree *map;
8894 int ret;
8895
8896 tree = &BTRFS_I(page->mapping->host)->io_tree;
8897 map = &BTRFS_I(page->mapping->host)->extent_tree;
8898 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
8899 if (ret == 1) {
8900 ClearPagePrivate(page);
8901 set_page_private(page, 0);
8902 put_page(page);
8903 }
8904 return ret;
8905 }
8906
8907 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8908 {
8909 if (PageWriteback(page) || PageDirty(page))
8910 return 0;
8911 return __btrfs_releasepage(page, gfp_flags);
8912 }
8913
8914 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8915 unsigned int length)
8916 {
8917 struct inode *inode = page->mapping->host;
8918 struct extent_io_tree *tree;
8919 struct btrfs_ordered_extent *ordered;
8920 struct extent_state *cached_state = NULL;
8921 u64 page_start = page_offset(page);
8922 u64 page_end = page_start + PAGE_SIZE - 1;
8923 u64 start;
8924 u64 end;
8925 int inode_evicting = inode->i_state & I_FREEING;
8926
8927 /*
8928 * we have the page locked, so new writeback can't start,
8929 * and the dirty bit won't be cleared while we are here.
8930 *
8931 * Wait for IO on this page so that we can safely clear
8932 * the PagePrivate2 bit and do ordered accounting
8933 */
8934 wait_on_page_writeback(page);
8935
8936 tree = &BTRFS_I(inode)->io_tree;
8937 if (offset) {
8938 btrfs_releasepage(page, GFP_NOFS);
8939 return;
8940 }
8941
8942 if (!inode_evicting)
8943 lock_extent_bits(tree, page_start, page_end, &cached_state);
8944 again:
8945 start = page_start;
8946 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
8947 page_end - start + 1);
8948 if (ordered) {
8949 end = min(page_end, ordered->file_offset + ordered->len - 1);
8950 /*
8951 * IO on this page will never be started, so we need
8952 * to account for any ordered extents now
8953 */
8954 if (!inode_evicting)
8955 clear_extent_bit(tree, start, end,
8956 EXTENT_DIRTY | EXTENT_DELALLOC |
8957 EXTENT_DELALLOC_NEW |
8958 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8959 EXTENT_DEFRAG, 1, 0, &cached_state,
8960 GFP_NOFS);
8961 /*
8962 * whoever cleared the private bit is responsible
8963 * for the finish_ordered_io
8964 */
8965 if (TestClearPagePrivate2(page)) {
8966 struct btrfs_ordered_inode_tree *tree;
8967 u64 new_len;
8968
8969 tree = &BTRFS_I(inode)->ordered_tree;
8970
8971 spin_lock_irq(&tree->lock);
8972 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8973 new_len = start - ordered->file_offset;
8974 if (new_len < ordered->truncated_len)
8975 ordered->truncated_len = new_len;
8976 spin_unlock_irq(&tree->lock);
8977
8978 if (btrfs_dec_test_ordered_pending(inode, &ordered,
8979 start,
8980 end - start + 1, 1))
8981 btrfs_finish_ordered_io(ordered);
8982 }
8983 btrfs_put_ordered_extent(ordered);
8984 if (!inode_evicting) {
8985 cached_state = NULL;
8986 lock_extent_bits(tree, start, end,
8987 &cached_state);
8988 }
8989
8990 start = end + 1;
8991 if (start < page_end)
8992 goto again;
8993 }
8994
8995 /*
8996 * Qgroup reserved space handler
8997 * Page here will be either
8998 * 1) Already written to disk
8999 * In this case, its reserved space is released from data rsv map
9000 * and will be freed by delayed_ref handler finally.
9001 * So even we call qgroup_free_data(), it won't decrease reserved
9002 * space.
9003 * 2) Not written to disk
9004 * This means the reserved space should be freed here. However,
9005 * if a truncate invalidates the page (by clearing PageDirty)
9006 * and the page is accounted for while allocating extent
9007 * in btrfs_check_data_free_space() we let delayed_ref to
9008 * free the entire extent.
9009 */
9010 if (PageDirty(page))
9011 btrfs_qgroup_free_data(inode, NULL, page_start, PAGE_SIZE);
9012 if (!inode_evicting) {
9013 clear_extent_bit(tree, page_start, page_end,
9014 EXTENT_LOCKED | EXTENT_DIRTY |
9015 EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
9016 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
9017 &cached_state, GFP_NOFS);
9018
9019 __btrfs_releasepage(page, GFP_NOFS);
9020 }
9021
9022 ClearPageChecked(page);
9023 if (PagePrivate(page)) {
9024 ClearPagePrivate(page);
9025 set_page_private(page, 0);
9026 put_page(page);
9027 }
9028 }
9029
9030 /*
9031 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
9032 * called from a page fault handler when a page is first dirtied. Hence we must
9033 * be careful to check for EOF conditions here. We set the page up correctly
9034 * for a written page which means we get ENOSPC checking when writing into
9035 * holes and correct delalloc and unwritten extent mapping on filesystems that
9036 * support these features.
9037 *
9038 * We are not allowed to take the i_mutex here so we have to play games to
9039 * protect against truncate races as the page could now be beyond EOF. Because
9040 * vmtruncate() writes the inode size before removing pages, once we have the
9041 * page lock we can determine safely if the page is beyond EOF. If it is not
9042 * beyond EOF, then the page is guaranteed safe against truncation until we
9043 * unlock the page.
9044 */
9045 int btrfs_page_mkwrite(struct vm_fault *vmf)
9046 {
9047 struct page *page = vmf->page;
9048 struct inode *inode = file_inode(vmf->vma->vm_file);
9049 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9050 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
9051 struct btrfs_ordered_extent *ordered;
9052 struct extent_state *cached_state = NULL;
9053 struct extent_changeset *data_reserved = NULL;
9054 char *kaddr;
9055 unsigned long zero_start;
9056 loff_t size;
9057 int ret;
9058 int reserved = 0;
9059 u64 reserved_space;
9060 u64 page_start;
9061 u64 page_end;
9062 u64 end;
9063
9064 reserved_space = PAGE_SIZE;
9065
9066 sb_start_pagefault(inode->i_sb);
9067 page_start = page_offset(page);
9068 page_end = page_start + PAGE_SIZE - 1;
9069 end = page_end;
9070
9071 /*
9072 * Reserving delalloc space after obtaining the page lock can lead to
9073 * deadlock. For example, if a dirty page is locked by this function
9074 * and the call to btrfs_delalloc_reserve_space() ends up triggering
9075 * dirty page write out, then the btrfs_writepage() function could
9076 * end up waiting indefinitely to get a lock on the page currently
9077 * being processed by btrfs_page_mkwrite() function.
9078 */
9079 ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
9080 reserved_space);
9081 if (!ret) {
9082 ret = file_update_time(vmf->vma->vm_file);
9083 reserved = 1;
9084 }
9085 if (ret) {
9086 if (ret == -ENOMEM)
9087 ret = VM_FAULT_OOM;
9088 else /* -ENOSPC, -EIO, etc */
9089 ret = VM_FAULT_SIGBUS;
9090 if (reserved)
9091 goto out;
9092 goto out_noreserve;
9093 }
9094
9095 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
9096 again:
9097 lock_page(page);
9098 size = i_size_read(inode);
9099
9100 if ((page->mapping != inode->i_mapping) ||
9101 (page_start >= size)) {
9102 /* page got truncated out from underneath us */
9103 goto out_unlock;
9104 }
9105 wait_on_page_writeback(page);
9106
9107 lock_extent_bits(io_tree, page_start, page_end, &cached_state);
9108 set_page_extent_mapped(page);
9109
9110 /*
9111 * we can't set the delalloc bits if there are pending ordered
9112 * extents. Drop our locks and wait for them to finish
9113 */
9114 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
9115 PAGE_SIZE);
9116 if (ordered) {
9117 unlock_extent_cached(io_tree, page_start, page_end,
9118 &cached_state, GFP_NOFS);
9119 unlock_page(page);
9120 btrfs_start_ordered_extent(inode, ordered, 1);
9121 btrfs_put_ordered_extent(ordered);
9122 goto again;
9123 }
9124
9125 if (page->index == ((size - 1) >> PAGE_SHIFT)) {
9126 reserved_space = round_up(size - page_start,
9127 fs_info->sectorsize);
9128 if (reserved_space < PAGE_SIZE) {
9129 end = page_start + reserved_space - 1;
9130 spin_lock(&BTRFS_I(inode)->lock);
9131 BTRFS_I(inode)->outstanding_extents++;
9132 spin_unlock(&BTRFS_I(inode)->lock);
9133 btrfs_delalloc_release_space(inode, data_reserved,
9134 page_start, PAGE_SIZE - reserved_space);
9135 }
9136 }
9137
9138 /*
9139 * page_mkwrite gets called when the page is firstly dirtied after it's
9140 * faulted in, but write(2) could also dirty a page and set delalloc
9141 * bits, thus in this case for space account reason, we still need to
9142 * clear any delalloc bits within this page range since we have to
9143 * reserve data&meta space before lock_page() (see above comments).
9144 */
9145 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
9146 EXTENT_DIRTY | EXTENT_DELALLOC |
9147 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
9148 0, 0, &cached_state, GFP_NOFS);
9149
9150 ret = btrfs_set_extent_delalloc(inode, page_start, end,
9151 &cached_state, 0);
9152 if (ret) {
9153 unlock_extent_cached(io_tree, page_start, page_end,
9154 &cached_state, GFP_NOFS);
9155 ret = VM_FAULT_SIGBUS;
9156 goto out_unlock;
9157 }
9158 ret = 0;
9159
9160 /* page is wholly or partially inside EOF */
9161 if (page_start + PAGE_SIZE > size)
9162 zero_start = size & ~PAGE_MASK;
9163 else
9164 zero_start = PAGE_SIZE;
9165
9166 if (zero_start != PAGE_SIZE) {
9167 kaddr = kmap(page);
9168 memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start);
9169 flush_dcache_page(page);
9170 kunmap(page);
9171 }
9172 ClearPageChecked(page);
9173 set_page_dirty(page);
9174 SetPageUptodate(page);
9175
9176 BTRFS_I(inode)->last_trans = fs_info->generation;
9177 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
9178 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
9179
9180 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
9181
9182 out_unlock:
9183 if (!ret) {
9184 sb_end_pagefault(inode->i_sb);
9185 extent_changeset_free(data_reserved);
9186 return VM_FAULT_LOCKED;
9187 }
9188 unlock_page(page);
9189 out:
9190 btrfs_delalloc_release_space(inode, data_reserved, page_start,
9191 reserved_space);
9192 out_noreserve:
9193 sb_end_pagefault(inode->i_sb);
9194 extent_changeset_free(data_reserved);
9195 return ret;
9196 }
9197
9198 static int btrfs_truncate(struct inode *inode)
9199 {
9200 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9201 struct btrfs_root *root = BTRFS_I(inode)->root;
9202 struct btrfs_block_rsv *rsv;
9203 int ret = 0;
9204 int err = 0;
9205 struct btrfs_trans_handle *trans;
9206 u64 mask = fs_info->sectorsize - 1;
9207 u64 min_size = btrfs_calc_trunc_metadata_size(fs_info, 1);
9208
9209 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
9210 (u64)-1);
9211 if (ret)
9212 return ret;
9213
9214 /*
9215 * Yes ladies and gentlemen, this is indeed ugly. The fact is we have
9216 * 3 things going on here
9217 *
9218 * 1) We need to reserve space for our orphan item and the space to
9219 * delete our orphan item. Lord knows we don't want to have a dangling
9220 * orphan item because we didn't reserve space to remove it.
9221 *
9222 * 2) We need to reserve space to update our inode.
9223 *
9224 * 3) We need to have something to cache all the space that is going to
9225 * be free'd up by the truncate operation, but also have some slack
9226 * space reserved in case it uses space during the truncate (thank you
9227 * very much snapshotting).
9228 *
9229 * And we need these to all be separate. The fact is we can use a lot of
9230 * space doing the truncate, and we have no earthly idea how much space
9231 * we will use, so we need the truncate reservation to be separate so it
9232 * doesn't end up using space reserved for updating the inode or
9233 * removing the orphan item. We also need to be able to stop the
9234 * transaction and start a new one, which means we need to be able to
9235 * update the inode several times, and we have no idea of knowing how
9236 * many times that will be, so we can't just reserve 1 item for the
9237 * entirety of the operation, so that has to be done separately as well.
9238 * Then there is the orphan item, which does indeed need to be held on
9239 * to for the whole operation, and we need nobody to touch this reserved
9240 * space except the orphan code.
9241 *
9242 * So that leaves us with
9243 *
9244 * 1) root->orphan_block_rsv - for the orphan deletion.
9245 * 2) rsv - for the truncate reservation, which we will steal from the
9246 * transaction reservation.
9247 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
9248 * updating the inode.
9249 */
9250 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
9251 if (!rsv)
9252 return -ENOMEM;
9253 rsv->size = min_size;
9254 rsv->failfast = 1;
9255
9256 /*
9257 * 1 for the truncate slack space
9258 * 1 for updating the inode.
9259 */
9260 trans = btrfs_start_transaction(root, 2);
9261 if (IS_ERR(trans)) {
9262 err = PTR_ERR(trans);
9263 goto out;
9264 }
9265
9266 /* Migrate the slack space for the truncate to our reserve */
9267 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
9268 min_size, 0);
9269 BUG_ON(ret);
9270
9271 /*
9272 * So if we truncate and then write and fsync we normally would just
9273 * write the extents that changed, which is a problem if we need to
9274 * first truncate that entire inode. So set this flag so we write out
9275 * all of the extents in the inode to the sync log so we're completely
9276 * safe.
9277 */
9278 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
9279 trans->block_rsv = rsv;
9280
9281 while (1) {
9282 ret = btrfs_truncate_inode_items(trans, root, inode,
9283 inode->i_size,
9284 BTRFS_EXTENT_DATA_KEY);
9285 if (ret != -ENOSPC && ret != -EAGAIN) {
9286 err = ret;
9287 break;
9288 }
9289
9290 trans->block_rsv = &fs_info->trans_block_rsv;
9291 ret = btrfs_update_inode(trans, root, inode);
9292 if (ret) {
9293 err = ret;
9294 break;
9295 }
9296
9297 btrfs_end_transaction(trans);
9298 btrfs_btree_balance_dirty(fs_info);
9299
9300 trans = btrfs_start_transaction(root, 2);
9301 if (IS_ERR(trans)) {
9302 ret = err = PTR_ERR(trans);
9303 trans = NULL;
9304 break;
9305 }
9306
9307 btrfs_block_rsv_release(fs_info, rsv, -1);
9308 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
9309 rsv, min_size, 0);
9310 BUG_ON(ret); /* shouldn't happen */
9311 trans->block_rsv = rsv;
9312 }
9313
9314 if (ret == 0 && inode->i_nlink > 0) {
9315 trans->block_rsv = root->orphan_block_rsv;
9316 ret = btrfs_orphan_del(trans, BTRFS_I(inode));
9317 if (ret)
9318 err = ret;
9319 }
9320
9321 if (trans) {
9322 trans->block_rsv = &fs_info->trans_block_rsv;
9323 ret = btrfs_update_inode(trans, root, inode);
9324 if (ret && !err)
9325 err = ret;
9326
9327 ret = btrfs_end_transaction(trans);
9328 btrfs_btree_balance_dirty(fs_info);
9329 }
9330 out:
9331 btrfs_free_block_rsv(fs_info, rsv);
9332
9333 if (ret && !err)
9334 err = ret;
9335
9336 return err;
9337 }
9338
9339 /*
9340 * create a new subvolume directory/inode (helper for the ioctl).
9341 */
9342 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
9343 struct btrfs_root *new_root,
9344 struct btrfs_root *parent_root,
9345 u64 new_dirid)
9346 {
9347 struct inode *inode;
9348 int err;
9349 u64 index = 0;
9350
9351 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
9352 new_dirid, new_dirid,
9353 S_IFDIR | (~current_umask() & S_IRWXUGO),
9354 &index);
9355 if (IS_ERR(inode))
9356 return PTR_ERR(inode);
9357 inode->i_op = &btrfs_dir_inode_operations;
9358 inode->i_fop = &btrfs_dir_file_operations;
9359
9360 set_nlink(inode, 1);
9361 btrfs_i_size_write(BTRFS_I(inode), 0);
9362 unlock_new_inode(inode);
9363
9364 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
9365 if (err)
9366 btrfs_err(new_root->fs_info,
9367 "error inheriting subvolume %llu properties: %d",
9368 new_root->root_key.objectid, err);
9369
9370 err = btrfs_update_inode(trans, new_root, inode);
9371
9372 iput(inode);
9373 return err;
9374 }
9375
9376 struct inode *btrfs_alloc_inode(struct super_block *sb)
9377 {
9378 struct btrfs_inode *ei;
9379 struct inode *inode;
9380
9381 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
9382 if (!ei)
9383 return NULL;
9384
9385 ei->root = NULL;
9386 ei->generation = 0;
9387 ei->last_trans = 0;
9388 ei->last_sub_trans = 0;
9389 ei->logged_trans = 0;
9390 ei->delalloc_bytes = 0;
9391 ei->new_delalloc_bytes = 0;
9392 ei->defrag_bytes = 0;
9393 ei->disk_i_size = 0;
9394 ei->flags = 0;
9395 ei->csum_bytes = 0;
9396 ei->index_cnt = (u64)-1;
9397 ei->dir_index = 0;
9398 ei->last_unlink_trans = 0;
9399 ei->last_log_commit = 0;
9400 ei->delayed_iput_count = 0;
9401
9402 spin_lock_init(&ei->lock);
9403 ei->outstanding_extents = 0;
9404 ei->reserved_extents = 0;
9405
9406 ei->runtime_flags = 0;
9407 ei->force_compress = BTRFS_COMPRESS_NONE;
9408
9409 ei->delayed_node = NULL;
9410
9411 ei->i_otime.tv_sec = 0;
9412 ei->i_otime.tv_nsec = 0;
9413
9414 inode = &ei->vfs_inode;
9415 extent_map_tree_init(&ei->extent_tree);
9416 extent_io_tree_init(&ei->io_tree, inode);
9417 extent_io_tree_init(&ei->io_failure_tree, inode);
9418 ei->io_tree.track_uptodate = 1;
9419 ei->io_failure_tree.track_uptodate = 1;
9420 atomic_set(&ei->sync_writers, 0);
9421 mutex_init(&ei->log_mutex);
9422 mutex_init(&ei->delalloc_mutex);
9423 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
9424 INIT_LIST_HEAD(&ei->delalloc_inodes);
9425 INIT_LIST_HEAD(&ei->delayed_iput);
9426 RB_CLEAR_NODE(&ei->rb_node);
9427 init_rwsem(&ei->dio_sem);
9428
9429 return inode;
9430 }
9431
9432 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
9433 void btrfs_test_destroy_inode(struct inode *inode)
9434 {
9435 btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
9436 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9437 }
9438 #endif
9439
9440 static void btrfs_i_callback(struct rcu_head *head)
9441 {
9442 struct inode *inode = container_of(head, struct inode, i_rcu);
9443 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9444 }
9445
9446 void btrfs_destroy_inode(struct inode *inode)
9447 {
9448 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9449 struct btrfs_ordered_extent *ordered;
9450 struct btrfs_root *root = BTRFS_I(inode)->root;
9451
9452 WARN_ON(!hlist_empty(&inode->i_dentry));
9453 WARN_ON(inode->i_data.nrpages);
9454 WARN_ON(BTRFS_I(inode)->outstanding_extents);
9455 WARN_ON(BTRFS_I(inode)->reserved_extents);
9456 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
9457 WARN_ON(BTRFS_I(inode)->new_delalloc_bytes);
9458 WARN_ON(BTRFS_I(inode)->csum_bytes);
9459 WARN_ON(BTRFS_I(inode)->defrag_bytes);
9460
9461 /*
9462 * This can happen where we create an inode, but somebody else also
9463 * created the same inode and we need to destroy the one we already
9464 * created.
9465 */
9466 if (!root)
9467 goto free;
9468
9469 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
9470 &BTRFS_I(inode)->runtime_flags)) {
9471 btrfs_info(fs_info, "inode %llu still on the orphan list",
9472 btrfs_ino(BTRFS_I(inode)));
9473 atomic_dec(&root->orphan_inodes);
9474 }
9475
9476 while (1) {
9477 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
9478 if (!ordered)
9479 break;
9480 else {
9481 btrfs_err(fs_info,
9482 "found ordered extent %llu %llu on inode cleanup",
9483 ordered->file_offset, ordered->len);
9484 btrfs_remove_ordered_extent(inode, ordered);
9485 btrfs_put_ordered_extent(ordered);
9486 btrfs_put_ordered_extent(ordered);
9487 }
9488 }
9489 btrfs_qgroup_check_reserved_leak(inode);
9490 inode_tree_del(inode);
9491 btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
9492 free:
9493 call_rcu(&inode->i_rcu, btrfs_i_callback);
9494 }
9495
9496 int btrfs_drop_inode(struct inode *inode)
9497 {
9498 struct btrfs_root *root = BTRFS_I(inode)->root;
9499
9500 if (root == NULL)
9501 return 1;
9502
9503 /* the snap/subvol tree is on deleting */
9504 if (btrfs_root_refs(&root->root_item) == 0)
9505 return 1;
9506 else
9507 return generic_drop_inode(inode);
9508 }
9509
9510 static void init_once(void *foo)
9511 {
9512 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
9513
9514 inode_init_once(&ei->vfs_inode);
9515 }
9516
9517 void btrfs_destroy_cachep(void)
9518 {
9519 /*
9520 * Make sure all delayed rcu free inodes are flushed before we
9521 * destroy cache.
9522 */
9523 rcu_barrier();
9524 kmem_cache_destroy(btrfs_inode_cachep);
9525 kmem_cache_destroy(btrfs_trans_handle_cachep);
9526 kmem_cache_destroy(btrfs_path_cachep);
9527 kmem_cache_destroy(btrfs_free_space_cachep);
9528 }
9529
9530 int btrfs_init_cachep(void)
9531 {
9532 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
9533 sizeof(struct btrfs_inode), 0,
9534 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
9535 init_once);
9536 if (!btrfs_inode_cachep)
9537 goto fail;
9538
9539 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
9540 sizeof(struct btrfs_trans_handle), 0,
9541 SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
9542 if (!btrfs_trans_handle_cachep)
9543 goto fail;
9544
9545 btrfs_path_cachep = kmem_cache_create("btrfs_path",
9546 sizeof(struct btrfs_path), 0,
9547 SLAB_MEM_SPREAD, NULL);
9548 if (!btrfs_path_cachep)
9549 goto fail;
9550
9551 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
9552 sizeof(struct btrfs_free_space), 0,
9553 SLAB_MEM_SPREAD, NULL);
9554 if (!btrfs_free_space_cachep)
9555 goto fail;
9556
9557 return 0;
9558 fail:
9559 btrfs_destroy_cachep();
9560 return -ENOMEM;
9561 }
9562
9563 static int btrfs_getattr(const struct path *path, struct kstat *stat,
9564 u32 request_mask, unsigned int flags)
9565 {
9566 u64 delalloc_bytes;
9567 struct inode *inode = d_inode(path->dentry);
9568 u32 blocksize = inode->i_sb->s_blocksize;
9569 u32 bi_flags = BTRFS_I(inode)->flags;
9570
9571 stat->result_mask |= STATX_BTIME;
9572 stat->btime.tv_sec = BTRFS_I(inode)->i_otime.tv_sec;
9573 stat->btime.tv_nsec = BTRFS_I(inode)->i_otime.tv_nsec;
9574 if (bi_flags & BTRFS_INODE_APPEND)
9575 stat->attributes |= STATX_ATTR_APPEND;
9576 if (bi_flags & BTRFS_INODE_COMPRESS)
9577 stat->attributes |= STATX_ATTR_COMPRESSED;
9578 if (bi_flags & BTRFS_INODE_IMMUTABLE)
9579 stat->attributes |= STATX_ATTR_IMMUTABLE;
9580 if (bi_flags & BTRFS_INODE_NODUMP)
9581 stat->attributes |= STATX_ATTR_NODUMP;
9582
9583 stat->attributes_mask |= (STATX_ATTR_APPEND |
9584 STATX_ATTR_COMPRESSED |
9585 STATX_ATTR_IMMUTABLE |
9586 STATX_ATTR_NODUMP);
9587
9588 generic_fillattr(inode, stat);
9589 stat->dev = BTRFS_I(inode)->root->anon_dev;
9590
9591 spin_lock(&BTRFS_I(inode)->lock);
9592 delalloc_bytes = BTRFS_I(inode)->new_delalloc_bytes;
9593 spin_unlock(&BTRFS_I(inode)->lock);
9594 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9595 ALIGN(delalloc_bytes, blocksize)) >> 9;
9596 return 0;
9597 }
9598
9599 static int btrfs_rename_exchange(struct inode *old_dir,
9600 struct dentry *old_dentry,
9601 struct inode *new_dir,
9602 struct dentry *new_dentry)
9603 {
9604 struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9605 struct btrfs_trans_handle *trans;
9606 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9607 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9608 struct inode *new_inode = new_dentry->d_inode;
9609 struct inode *old_inode = old_dentry->d_inode;
9610 struct timespec ctime = current_time(old_inode);
9611 struct dentry *parent;
9612 u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
9613 u64 new_ino = btrfs_ino(BTRFS_I(new_inode));
9614 u64 old_idx = 0;
9615 u64 new_idx = 0;
9616 u64 root_objectid;
9617 int ret;
9618 bool root_log_pinned = false;
9619 bool dest_log_pinned = false;
9620
9621 /* we only allow rename subvolume link between subvolumes */
9622 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9623 return -EXDEV;
9624
9625 /* close the race window with snapshot create/destroy ioctl */
9626 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9627 down_read(&fs_info->subvol_sem);
9628 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9629 down_read(&fs_info->subvol_sem);
9630
9631 /*
9632 * We want to reserve the absolute worst case amount of items. So if
9633 * both inodes are subvols and we need to unlink them then that would
9634 * require 4 item modifications, but if they are both normal inodes it
9635 * would require 5 item modifications, so we'll assume their normal
9636 * inodes. So 5 * 2 is 10, plus 2 for the new links, so 12 total items
9637 * should cover the worst case number of items we'll modify.
9638 */
9639 trans = btrfs_start_transaction(root, 12);
9640 if (IS_ERR(trans)) {
9641 ret = PTR_ERR(trans);
9642 goto out_notrans;
9643 }
9644
9645 /*
9646 * We need to find a free sequence number both in the source and
9647 * in the destination directory for the exchange.
9648 */
9649 ret = btrfs_set_inode_index(BTRFS_I(new_dir), &old_idx);
9650 if (ret)
9651 goto out_fail;
9652 ret = btrfs_set_inode_index(BTRFS_I(old_dir), &new_idx);
9653 if (ret)
9654 goto out_fail;
9655
9656 BTRFS_I(old_inode)->dir_index = 0ULL;
9657 BTRFS_I(new_inode)->dir_index = 0ULL;
9658
9659 /* Reference for the source. */
9660 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9661 /* force full log commit if subvolume involved. */
9662 btrfs_set_log_full_commit(fs_info, trans);
9663 } else {
9664 btrfs_pin_log_trans(root);
9665 root_log_pinned = true;
9666 ret = btrfs_insert_inode_ref(trans, dest,
9667 new_dentry->d_name.name,
9668 new_dentry->d_name.len,
9669 old_ino,
9670 btrfs_ino(BTRFS_I(new_dir)),
9671 old_idx);
9672 if (ret)
9673 goto out_fail;
9674 }
9675
9676 /* And now for the dest. */
9677 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9678 /* force full log commit if subvolume involved. */
9679 btrfs_set_log_full_commit(fs_info, trans);
9680 } else {
9681 btrfs_pin_log_trans(dest);
9682 dest_log_pinned = true;
9683 ret = btrfs_insert_inode_ref(trans, root,
9684 old_dentry->d_name.name,
9685 old_dentry->d_name.len,
9686 new_ino,
9687 btrfs_ino(BTRFS_I(old_dir)),
9688 new_idx);
9689 if (ret)
9690 goto out_fail;
9691 }
9692
9693 /* Update inode version and ctime/mtime. */
9694 inode_inc_iversion(old_dir);
9695 inode_inc_iversion(new_dir);
9696 inode_inc_iversion(old_inode);
9697 inode_inc_iversion(new_inode);
9698 old_dir->i_ctime = old_dir->i_mtime = ctime;
9699 new_dir->i_ctime = new_dir->i_mtime = ctime;
9700 old_inode->i_ctime = ctime;
9701 new_inode->i_ctime = ctime;
9702
9703 if (old_dentry->d_parent != new_dentry->d_parent) {
9704 btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
9705 BTRFS_I(old_inode), 1);
9706 btrfs_record_unlink_dir(trans, BTRFS_I(new_dir),
9707 BTRFS_I(new_inode), 1);
9708 }
9709
9710 /* src is a subvolume */
9711 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9712 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9713 ret = btrfs_unlink_subvol(trans, root, old_dir,
9714 root_objectid,
9715 old_dentry->d_name.name,
9716 old_dentry->d_name.len);
9717 } else { /* src is an inode */
9718 ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
9719 BTRFS_I(old_dentry->d_inode),
9720 old_dentry->d_name.name,
9721 old_dentry->d_name.len);
9722 if (!ret)
9723 ret = btrfs_update_inode(trans, root, old_inode);
9724 }
9725 if (ret) {
9726 btrfs_abort_transaction(trans, ret);
9727 goto out_fail;
9728 }
9729
9730 /* dest is a subvolume */
9731 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9732 root_objectid = BTRFS_I(new_inode)->root->root_key.objectid;
9733 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9734 root_objectid,
9735 new_dentry->d_name.name,
9736 new_dentry->d_name.len);
9737 } else { /* dest is an inode */
9738 ret = __btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
9739 BTRFS_I(new_dentry->d_inode),
9740 new_dentry->d_name.name,
9741 new_dentry->d_name.len);
9742 if (!ret)
9743 ret = btrfs_update_inode(trans, dest, new_inode);
9744 }
9745 if (ret) {
9746 btrfs_abort_transaction(trans, ret);
9747 goto out_fail;
9748 }
9749
9750 ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
9751 new_dentry->d_name.name,
9752 new_dentry->d_name.len, 0, old_idx);
9753 if (ret) {
9754 btrfs_abort_transaction(trans, ret);
9755 goto out_fail;
9756 }
9757
9758 ret = btrfs_add_link(trans, BTRFS_I(old_dir), BTRFS_I(new_inode),
9759 old_dentry->d_name.name,
9760 old_dentry->d_name.len, 0, new_idx);
9761 if (ret) {
9762 btrfs_abort_transaction(trans, ret);
9763 goto out_fail;
9764 }
9765
9766 if (old_inode->i_nlink == 1)
9767 BTRFS_I(old_inode)->dir_index = old_idx;
9768 if (new_inode->i_nlink == 1)
9769 BTRFS_I(new_inode)->dir_index = new_idx;
9770
9771 if (root_log_pinned) {
9772 parent = new_dentry->d_parent;
9773 btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir),
9774 parent);
9775 btrfs_end_log_trans(root);
9776 root_log_pinned = false;
9777 }
9778 if (dest_log_pinned) {
9779 parent = old_dentry->d_parent;
9780 btrfs_log_new_name(trans, BTRFS_I(new_inode), BTRFS_I(new_dir),
9781 parent);
9782 btrfs_end_log_trans(dest);
9783 dest_log_pinned = false;
9784 }
9785 out_fail:
9786 /*
9787 * If we have pinned a log and an error happened, we unpin tasks
9788 * trying to sync the log and force them to fallback to a transaction
9789 * commit if the log currently contains any of the inodes involved in
9790 * this rename operation (to ensure we do not persist a log with an
9791 * inconsistent state for any of these inodes or leading to any
9792 * inconsistencies when replayed). If the transaction was aborted, the
9793 * abortion reason is propagated to userspace when attempting to commit
9794 * the transaction. If the log does not contain any of these inodes, we
9795 * allow the tasks to sync it.
9796 */
9797 if (ret && (root_log_pinned || dest_log_pinned)) {
9798 if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
9799 btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
9800 btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
9801 (new_inode &&
9802 btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
9803 btrfs_set_log_full_commit(fs_info, trans);
9804
9805 if (root_log_pinned) {
9806 btrfs_end_log_trans(root);
9807 root_log_pinned = false;
9808 }
9809 if (dest_log_pinned) {
9810 btrfs_end_log_trans(dest);
9811 dest_log_pinned = false;
9812 }
9813 }
9814 ret = btrfs_end_transaction(trans);
9815 out_notrans:
9816 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9817 up_read(&fs_info->subvol_sem);
9818 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9819 up_read(&fs_info->subvol_sem);
9820
9821 return ret;
9822 }
9823
9824 static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans,
9825 struct btrfs_root *root,
9826 struct inode *dir,
9827 struct dentry *dentry)
9828 {
9829 int ret;
9830 struct inode *inode;
9831 u64 objectid;
9832 u64 index;
9833
9834 ret = btrfs_find_free_ino(root, &objectid);
9835 if (ret)
9836 return ret;
9837
9838 inode = btrfs_new_inode(trans, root, dir,
9839 dentry->d_name.name,
9840 dentry->d_name.len,
9841 btrfs_ino(BTRFS_I(dir)),
9842 objectid,
9843 S_IFCHR | WHITEOUT_MODE,
9844 &index);
9845
9846 if (IS_ERR(inode)) {
9847 ret = PTR_ERR(inode);
9848 return ret;
9849 }
9850
9851 inode->i_op = &btrfs_special_inode_operations;
9852 init_special_inode(inode, inode->i_mode,
9853 WHITEOUT_DEV);
9854
9855 ret = btrfs_init_inode_security(trans, inode, dir,
9856 &dentry->d_name);
9857 if (ret)
9858 goto out;
9859
9860 ret = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
9861 BTRFS_I(inode), 0, index);
9862 if (ret)
9863 goto out;
9864
9865 ret = btrfs_update_inode(trans, root, inode);
9866 out:
9867 unlock_new_inode(inode);
9868 if (ret)
9869 inode_dec_link_count(inode);
9870 iput(inode);
9871
9872 return ret;
9873 }
9874
9875 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9876 struct inode *new_dir, struct dentry *new_dentry,
9877 unsigned int flags)
9878 {
9879 struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9880 struct btrfs_trans_handle *trans;
9881 unsigned int trans_num_items;
9882 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9883 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9884 struct inode *new_inode = d_inode(new_dentry);
9885 struct inode *old_inode = d_inode(old_dentry);
9886 u64 index = 0;
9887 u64 root_objectid;
9888 int ret;
9889 u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
9890 bool log_pinned = false;
9891
9892 if (btrfs_ino(BTRFS_I(new_dir)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9893 return -EPERM;
9894
9895 /* we only allow rename subvolume link between subvolumes */
9896 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9897 return -EXDEV;
9898
9899 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9900 (new_inode && btrfs_ino(BTRFS_I(new_inode)) == BTRFS_FIRST_FREE_OBJECTID))
9901 return -ENOTEMPTY;
9902
9903 if (S_ISDIR(old_inode->i_mode) && new_inode &&
9904 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9905 return -ENOTEMPTY;
9906
9907
9908 /* check for collisions, even if the name isn't there */
9909 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9910 new_dentry->d_name.name,
9911 new_dentry->d_name.len);
9912
9913 if (ret) {
9914 if (ret == -EEXIST) {
9915 /* we shouldn't get
9916 * eexist without a new_inode */
9917 if (WARN_ON(!new_inode)) {
9918 return ret;
9919 }
9920 } else {
9921 /* maybe -EOVERFLOW */
9922 return ret;
9923 }
9924 }
9925 ret = 0;
9926
9927 /*
9928 * we're using rename to replace one file with another. Start IO on it
9929 * now so we don't add too much work to the end of the transaction
9930 */
9931 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9932 filemap_flush(old_inode->i_mapping);
9933
9934 /* close the racy window with snapshot create/destroy ioctl */
9935 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9936 down_read(&fs_info->subvol_sem);
9937 /*
9938 * We want to reserve the absolute worst case amount of items. So if
9939 * both inodes are subvols and we need to unlink them then that would
9940 * require 4 item modifications, but if they are both normal inodes it
9941 * would require 5 item modifications, so we'll assume they are normal
9942 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
9943 * should cover the worst case number of items we'll modify.
9944 * If our rename has the whiteout flag, we need more 5 units for the
9945 * new inode (1 inode item, 1 inode ref, 2 dir items and 1 xattr item
9946 * when selinux is enabled).
9947 */
9948 trans_num_items = 11;
9949 if (flags & RENAME_WHITEOUT)
9950 trans_num_items += 5;
9951 trans = btrfs_start_transaction(root, trans_num_items);
9952 if (IS_ERR(trans)) {
9953 ret = PTR_ERR(trans);
9954 goto out_notrans;
9955 }
9956
9957 if (dest != root)
9958 btrfs_record_root_in_trans(trans, dest);
9959
9960 ret = btrfs_set_inode_index(BTRFS_I(new_dir), &index);
9961 if (ret)
9962 goto out_fail;
9963
9964 BTRFS_I(old_inode)->dir_index = 0ULL;
9965 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9966 /* force full log commit if subvolume involved. */
9967 btrfs_set_log_full_commit(fs_info, trans);
9968 } else {
9969 btrfs_pin_log_trans(root);
9970 log_pinned = true;
9971 ret = btrfs_insert_inode_ref(trans, dest,
9972 new_dentry->d_name.name,
9973 new_dentry->d_name.len,
9974 old_ino,
9975 btrfs_ino(BTRFS_I(new_dir)), index);
9976 if (ret)
9977 goto out_fail;
9978 }
9979
9980 inode_inc_iversion(old_dir);
9981 inode_inc_iversion(new_dir);
9982 inode_inc_iversion(old_inode);
9983 old_dir->i_ctime = old_dir->i_mtime =
9984 new_dir->i_ctime = new_dir->i_mtime =
9985 old_inode->i_ctime = current_time(old_dir);
9986
9987 if (old_dentry->d_parent != new_dentry->d_parent)
9988 btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
9989 BTRFS_I(old_inode), 1);
9990
9991 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9992 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9993 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
9994 old_dentry->d_name.name,
9995 old_dentry->d_name.len);
9996 } else {
9997 ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
9998 BTRFS_I(d_inode(old_dentry)),
9999 old_dentry->d_name.name,
10000 old_dentry->d_name.len);
10001 if (!ret)
10002 ret = btrfs_update_inode(trans, root, old_inode);
10003 }
10004 if (ret) {
10005 btrfs_abort_transaction(trans, ret);
10006 goto out_fail;
10007 }
10008
10009 if (new_inode) {
10010 inode_inc_iversion(new_inode);
10011 new_inode->i_ctime = current_time(new_inode);
10012 if (unlikely(btrfs_ino(BTRFS_I(new_inode)) ==
10013 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
10014 root_objectid = BTRFS_I(new_inode)->location.objectid;
10015 ret = btrfs_unlink_subvol(trans, dest, new_dir,
10016 root_objectid,
10017 new_dentry->d_name.name,
10018 new_dentry->d_name.len);
10019 BUG_ON(new_inode->i_nlink == 0);
10020 } else {
10021 ret = btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
10022 BTRFS_I(d_inode(new_dentry)),
10023 new_dentry->d_name.name,
10024 new_dentry->d_name.len);
10025 }
10026 if (!ret && new_inode->i_nlink == 0)
10027 ret = btrfs_orphan_add(trans,
10028 BTRFS_I(d_inode(new_dentry)));
10029 if (ret) {
10030 btrfs_abort_transaction(trans, ret);
10031 goto out_fail;
10032 }
10033 }
10034
10035 ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
10036 new_dentry->d_name.name,
10037 new_dentry->d_name.len, 0, index);
10038 if (ret) {
10039 btrfs_abort_transaction(trans, ret);
10040 goto out_fail;
10041 }
10042
10043 if (old_inode->i_nlink == 1)
10044 BTRFS_I(old_inode)->dir_index = index;
10045
10046 if (log_pinned) {
10047 struct dentry *parent = new_dentry->d_parent;
10048
10049 btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir),
10050 parent);
10051 btrfs_end_log_trans(root);
10052 log_pinned = false;
10053 }
10054
10055 if (flags & RENAME_WHITEOUT) {
10056 ret = btrfs_whiteout_for_rename(trans, root, old_dir,
10057 old_dentry);
10058
10059 if (ret) {
10060 btrfs_abort_transaction(trans, ret);
10061 goto out_fail;
10062 }
10063 }
10064 out_fail:
10065 /*
10066 * If we have pinned the log and an error happened, we unpin tasks
10067 * trying to sync the log and force them to fallback to a transaction
10068 * commit if the log currently contains any of the inodes involved in
10069 * this rename operation (to ensure we do not persist a log with an
10070 * inconsistent state for any of these inodes or leading to any
10071 * inconsistencies when replayed). If the transaction was aborted, the
10072 * abortion reason is propagated to userspace when attempting to commit
10073 * the transaction. If the log does not contain any of these inodes, we
10074 * allow the tasks to sync it.
10075 */
10076 if (ret && log_pinned) {
10077 if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
10078 btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
10079 btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
10080 (new_inode &&
10081 btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
10082 btrfs_set_log_full_commit(fs_info, trans);
10083
10084 btrfs_end_log_trans(root);
10085 log_pinned = false;
10086 }
10087 btrfs_end_transaction(trans);
10088 out_notrans:
10089 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
10090 up_read(&fs_info->subvol_sem);
10091
10092 return ret;
10093 }
10094
10095 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
10096 struct inode *new_dir, struct dentry *new_dentry,
10097 unsigned int flags)
10098 {
10099 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
10100 return -EINVAL;
10101
10102 if (flags & RENAME_EXCHANGE)
10103 return btrfs_rename_exchange(old_dir, old_dentry, new_dir,
10104 new_dentry);
10105
10106 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
10107 }
10108
10109 static void btrfs_run_delalloc_work(struct btrfs_work *work)
10110 {
10111 struct btrfs_delalloc_work *delalloc_work;
10112 struct inode *inode;
10113
10114 delalloc_work = container_of(work, struct btrfs_delalloc_work,
10115 work);
10116 inode = delalloc_work->inode;
10117 filemap_flush(inode->i_mapping);
10118 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
10119 &BTRFS_I(inode)->runtime_flags))
10120 filemap_flush(inode->i_mapping);
10121
10122 if (delalloc_work->delay_iput)
10123 btrfs_add_delayed_iput(inode);
10124 else
10125 iput(inode);
10126 complete(&delalloc_work->completion);
10127 }
10128
10129 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
10130 int delay_iput)
10131 {
10132 struct btrfs_delalloc_work *work;
10133
10134 work = kmalloc(sizeof(*work), GFP_NOFS);
10135 if (!work)
10136 return NULL;
10137
10138 init_completion(&work->completion);
10139 INIT_LIST_HEAD(&work->list);
10140 work->inode = inode;
10141 work->delay_iput = delay_iput;
10142 WARN_ON_ONCE(!inode);
10143 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
10144 btrfs_run_delalloc_work, NULL, NULL);
10145
10146 return work;
10147 }
10148
10149 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
10150 {
10151 wait_for_completion(&work->completion);
10152 kfree(work);
10153 }
10154
10155 /*
10156 * some fairly slow code that needs optimization. This walks the list
10157 * of all the inodes with pending delalloc and forces them to disk.
10158 */
10159 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
10160 int nr)
10161 {
10162 struct btrfs_inode *binode;
10163 struct inode *inode;
10164 struct btrfs_delalloc_work *work, *next;
10165 struct list_head works;
10166 struct list_head splice;
10167 int ret = 0;
10168
10169 INIT_LIST_HEAD(&works);
10170 INIT_LIST_HEAD(&splice);
10171
10172 mutex_lock(&root->delalloc_mutex);
10173 spin_lock(&root->delalloc_lock);
10174 list_splice_init(&root->delalloc_inodes, &splice);
10175 while (!list_empty(&splice)) {
10176 binode = list_entry(splice.next, struct btrfs_inode,
10177 delalloc_inodes);
10178
10179 list_move_tail(&binode->delalloc_inodes,
10180 &root->delalloc_inodes);
10181 inode = igrab(&binode->vfs_inode);
10182 if (!inode) {
10183 cond_resched_lock(&root->delalloc_lock);
10184 continue;
10185 }
10186 spin_unlock(&root->delalloc_lock);
10187
10188 work = btrfs_alloc_delalloc_work(inode, delay_iput);
10189 if (!work) {
10190 if (delay_iput)
10191 btrfs_add_delayed_iput(inode);
10192 else
10193 iput(inode);
10194 ret = -ENOMEM;
10195 goto out;
10196 }
10197 list_add_tail(&work->list, &works);
10198 btrfs_queue_work(root->fs_info->flush_workers,
10199 &work->work);
10200 ret++;
10201 if (nr != -1 && ret >= nr)
10202 goto out;
10203 cond_resched();
10204 spin_lock(&root->delalloc_lock);
10205 }
10206 spin_unlock(&root->delalloc_lock);
10207
10208 out:
10209 list_for_each_entry_safe(work, next, &works, list) {
10210 list_del_init(&work->list);
10211 btrfs_wait_and_free_delalloc_work(work);
10212 }
10213
10214 if (!list_empty_careful(&splice)) {
10215 spin_lock(&root->delalloc_lock);
10216 list_splice_tail(&splice, &root->delalloc_inodes);
10217 spin_unlock(&root->delalloc_lock);
10218 }
10219 mutex_unlock(&root->delalloc_mutex);
10220 return ret;
10221 }
10222
10223 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
10224 {
10225 struct btrfs_fs_info *fs_info = root->fs_info;
10226 int ret;
10227
10228 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10229 return -EROFS;
10230
10231 ret = __start_delalloc_inodes(root, delay_iput, -1);
10232 if (ret > 0)
10233 ret = 0;
10234 /*
10235 * the filemap_flush will queue IO into the worker threads, but
10236 * we have to make sure the IO is actually started and that
10237 * ordered extents get created before we return
10238 */
10239 atomic_inc(&fs_info->async_submit_draining);
10240 while (atomic_read(&fs_info->nr_async_submits) ||
10241 atomic_read(&fs_info->async_delalloc_pages)) {
10242 wait_event(fs_info->async_submit_wait,
10243 (atomic_read(&fs_info->nr_async_submits) == 0 &&
10244 atomic_read(&fs_info->async_delalloc_pages) == 0));
10245 }
10246 atomic_dec(&fs_info->async_submit_draining);
10247 return ret;
10248 }
10249
10250 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
10251 int nr)
10252 {
10253 struct btrfs_root *root;
10254 struct list_head splice;
10255 int ret;
10256
10257 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10258 return -EROFS;
10259
10260 INIT_LIST_HEAD(&splice);
10261
10262 mutex_lock(&fs_info->delalloc_root_mutex);
10263 spin_lock(&fs_info->delalloc_root_lock);
10264 list_splice_init(&fs_info->delalloc_roots, &splice);
10265 while (!list_empty(&splice) && nr) {
10266 root = list_first_entry(&splice, struct btrfs_root,
10267 delalloc_root);
10268 root = btrfs_grab_fs_root(root);
10269 BUG_ON(!root);
10270 list_move_tail(&root->delalloc_root,
10271 &fs_info->delalloc_roots);
10272 spin_unlock(&fs_info->delalloc_root_lock);
10273
10274 ret = __start_delalloc_inodes(root, delay_iput, nr);
10275 btrfs_put_fs_root(root);
10276 if (ret < 0)
10277 goto out;
10278
10279 if (nr != -1) {
10280 nr -= ret;
10281 WARN_ON(nr < 0);
10282 }
10283 spin_lock(&fs_info->delalloc_root_lock);
10284 }
10285 spin_unlock(&fs_info->delalloc_root_lock);
10286
10287 ret = 0;
10288 atomic_inc(&fs_info->async_submit_draining);
10289 while (atomic_read(&fs_info->nr_async_submits) ||
10290 atomic_read(&fs_info->async_delalloc_pages)) {
10291 wait_event(fs_info->async_submit_wait,
10292 (atomic_read(&fs_info->nr_async_submits) == 0 &&
10293 atomic_read(&fs_info->async_delalloc_pages) == 0));
10294 }
10295 atomic_dec(&fs_info->async_submit_draining);
10296 out:
10297 if (!list_empty_careful(&splice)) {
10298 spin_lock(&fs_info->delalloc_root_lock);
10299 list_splice_tail(&splice, &fs_info->delalloc_roots);
10300 spin_unlock(&fs_info->delalloc_root_lock);
10301 }
10302 mutex_unlock(&fs_info->delalloc_root_mutex);
10303 return ret;
10304 }
10305
10306 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
10307 const char *symname)
10308 {
10309 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
10310 struct btrfs_trans_handle *trans;
10311 struct btrfs_root *root = BTRFS_I(dir)->root;
10312 struct btrfs_path *path;
10313 struct btrfs_key key;
10314 struct inode *inode = NULL;
10315 int err;
10316 int drop_inode = 0;
10317 u64 objectid;
10318 u64 index = 0;
10319 int name_len;
10320 int datasize;
10321 unsigned long ptr;
10322 struct btrfs_file_extent_item *ei;
10323 struct extent_buffer *leaf;
10324
10325 name_len = strlen(symname);
10326 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info))
10327 return -ENAMETOOLONG;
10328
10329 /*
10330 * 2 items for inode item and ref
10331 * 2 items for dir items
10332 * 1 item for updating parent inode item
10333 * 1 item for the inline extent item
10334 * 1 item for xattr if selinux is on
10335 */
10336 trans = btrfs_start_transaction(root, 7);
10337 if (IS_ERR(trans))
10338 return PTR_ERR(trans);
10339
10340 err = btrfs_find_free_ino(root, &objectid);
10341 if (err)
10342 goto out_unlock;
10343
10344 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
10345 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)),
10346 objectid, S_IFLNK|S_IRWXUGO, &index);
10347 if (IS_ERR(inode)) {
10348 err = PTR_ERR(inode);
10349 goto out_unlock;
10350 }
10351
10352 /*
10353 * If the active LSM wants to access the inode during
10354 * d_instantiate it needs these. Smack checks to see
10355 * if the filesystem supports xattrs by looking at the
10356 * ops vector.
10357 */
10358 inode->i_fop = &btrfs_file_operations;
10359 inode->i_op = &btrfs_file_inode_operations;
10360 inode->i_mapping->a_ops = &btrfs_aops;
10361 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10362
10363 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
10364 if (err)
10365 goto out_unlock_inode;
10366
10367 path = btrfs_alloc_path();
10368 if (!path) {
10369 err = -ENOMEM;
10370 goto out_unlock_inode;
10371 }
10372 key.objectid = btrfs_ino(BTRFS_I(inode));
10373 key.offset = 0;
10374 key.type = BTRFS_EXTENT_DATA_KEY;
10375 datasize = btrfs_file_extent_calc_inline_size(name_len);
10376 err = btrfs_insert_empty_item(trans, root, path, &key,
10377 datasize);
10378 if (err) {
10379 btrfs_free_path(path);
10380 goto out_unlock_inode;
10381 }
10382 leaf = path->nodes[0];
10383 ei = btrfs_item_ptr(leaf, path->slots[0],
10384 struct btrfs_file_extent_item);
10385 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
10386 btrfs_set_file_extent_type(leaf, ei,
10387 BTRFS_FILE_EXTENT_INLINE);
10388 btrfs_set_file_extent_encryption(leaf, ei, 0);
10389 btrfs_set_file_extent_compression(leaf, ei, 0);
10390 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
10391 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
10392
10393 ptr = btrfs_file_extent_inline_start(ei);
10394 write_extent_buffer(leaf, symname, ptr, name_len);
10395 btrfs_mark_buffer_dirty(leaf);
10396 btrfs_free_path(path);
10397
10398 inode->i_op = &btrfs_symlink_inode_operations;
10399 inode_nohighmem(inode);
10400 inode->i_mapping->a_ops = &btrfs_symlink_aops;
10401 inode_set_bytes(inode, name_len);
10402 btrfs_i_size_write(BTRFS_I(inode), name_len);
10403 err = btrfs_update_inode(trans, root, inode);
10404 /*
10405 * Last step, add directory indexes for our symlink inode. This is the
10406 * last step to avoid extra cleanup of these indexes if an error happens
10407 * elsewhere above.
10408 */
10409 if (!err)
10410 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
10411 BTRFS_I(inode), 0, index);
10412 if (err) {
10413 drop_inode = 1;
10414 goto out_unlock_inode;
10415 }
10416
10417 unlock_new_inode(inode);
10418 d_instantiate(dentry, inode);
10419
10420 out_unlock:
10421 btrfs_end_transaction(trans);
10422 if (drop_inode) {
10423 inode_dec_link_count(inode);
10424 iput(inode);
10425 }
10426 btrfs_btree_balance_dirty(fs_info);
10427 return err;
10428
10429 out_unlock_inode:
10430 drop_inode = 1;
10431 unlock_new_inode(inode);
10432 goto out_unlock;
10433 }
10434
10435 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
10436 u64 start, u64 num_bytes, u64 min_size,
10437 loff_t actual_len, u64 *alloc_hint,
10438 struct btrfs_trans_handle *trans)
10439 {
10440 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
10441 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
10442 struct extent_map *em;
10443 struct btrfs_root *root = BTRFS_I(inode)->root;
10444 struct btrfs_key ins;
10445 u64 cur_offset = start;
10446 u64 i_size;
10447 u64 cur_bytes;
10448 u64 last_alloc = (u64)-1;
10449 int ret = 0;
10450 bool own_trans = true;
10451 u64 end = start + num_bytes - 1;
10452
10453 if (trans)
10454 own_trans = false;
10455 while (num_bytes > 0) {
10456 if (own_trans) {
10457 trans = btrfs_start_transaction(root, 3);
10458 if (IS_ERR(trans)) {
10459 ret = PTR_ERR(trans);
10460 break;
10461 }
10462 }
10463
10464 cur_bytes = min_t(u64, num_bytes, SZ_256M);
10465 cur_bytes = max(cur_bytes, min_size);
10466 /*
10467 * If we are severely fragmented we could end up with really
10468 * small allocations, so if the allocator is returning small
10469 * chunks lets make its job easier by only searching for those
10470 * sized chunks.
10471 */
10472 cur_bytes = min(cur_bytes, last_alloc);
10473 ret = btrfs_reserve_extent(root, cur_bytes, cur_bytes,
10474 min_size, 0, *alloc_hint, &ins, 1, 0);
10475 if (ret) {
10476 if (own_trans)
10477 btrfs_end_transaction(trans);
10478 break;
10479 }
10480 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
10481
10482 last_alloc = ins.offset;
10483 ret = insert_reserved_file_extent(trans, inode,
10484 cur_offset, ins.objectid,
10485 ins.offset, ins.offset,
10486 ins.offset, 0, 0, 0,
10487 BTRFS_FILE_EXTENT_PREALLOC);
10488 if (ret) {
10489 btrfs_free_reserved_extent(fs_info, ins.objectid,
10490 ins.offset, 0);
10491 btrfs_abort_transaction(trans, ret);
10492 if (own_trans)
10493 btrfs_end_transaction(trans);
10494 break;
10495 }
10496
10497 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
10498 cur_offset + ins.offset -1, 0);
10499
10500 em = alloc_extent_map();
10501 if (!em) {
10502 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
10503 &BTRFS_I(inode)->runtime_flags);
10504 goto next;
10505 }
10506
10507 em->start = cur_offset;
10508 em->orig_start = cur_offset;
10509 em->len = ins.offset;
10510 em->block_start = ins.objectid;
10511 em->block_len = ins.offset;
10512 em->orig_block_len = ins.offset;
10513 em->ram_bytes = ins.offset;
10514 em->bdev = fs_info->fs_devices->latest_bdev;
10515 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
10516 em->generation = trans->transid;
10517
10518 while (1) {
10519 write_lock(&em_tree->lock);
10520 ret = add_extent_mapping(em_tree, em, 1);
10521 write_unlock(&em_tree->lock);
10522 if (ret != -EEXIST)
10523 break;
10524 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
10525 cur_offset + ins.offset - 1,
10526 0);
10527 }
10528 free_extent_map(em);
10529 next:
10530 num_bytes -= ins.offset;
10531 cur_offset += ins.offset;
10532 *alloc_hint = ins.objectid + ins.offset;
10533
10534 inode_inc_iversion(inode);
10535 inode->i_ctime = current_time(inode);
10536 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
10537 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
10538 (actual_len > inode->i_size) &&
10539 (cur_offset > inode->i_size)) {
10540 if (cur_offset > actual_len)
10541 i_size = actual_len;
10542 else
10543 i_size = cur_offset;
10544 i_size_write(inode, i_size);
10545 btrfs_ordered_update_i_size(inode, i_size, NULL);
10546 }
10547
10548 ret = btrfs_update_inode(trans, root, inode);
10549
10550 if (ret) {
10551 btrfs_abort_transaction(trans, ret);
10552 if (own_trans)
10553 btrfs_end_transaction(trans);
10554 break;
10555 }
10556
10557 if (own_trans)
10558 btrfs_end_transaction(trans);
10559 }
10560 if (cur_offset < end)
10561 btrfs_free_reserved_data_space(inode, NULL, cur_offset,
10562 end - cur_offset + 1);
10563 return ret;
10564 }
10565
10566 int btrfs_prealloc_file_range(struct inode *inode, int mode,
10567 u64 start, u64 num_bytes, u64 min_size,
10568 loff_t actual_len, u64 *alloc_hint)
10569 {
10570 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10571 min_size, actual_len, alloc_hint,
10572 NULL);
10573 }
10574
10575 int btrfs_prealloc_file_range_trans(struct inode *inode,
10576 struct btrfs_trans_handle *trans, int mode,
10577 u64 start, u64 num_bytes, u64 min_size,
10578 loff_t actual_len, u64 *alloc_hint)
10579 {
10580 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10581 min_size, actual_len, alloc_hint, trans);
10582 }
10583
10584 static int btrfs_set_page_dirty(struct page *page)
10585 {
10586 return __set_page_dirty_nobuffers(page);
10587 }
10588
10589 static int btrfs_permission(struct inode *inode, int mask)
10590 {
10591 struct btrfs_root *root = BTRFS_I(inode)->root;
10592 umode_t mode = inode->i_mode;
10593
10594 if (mask & MAY_WRITE &&
10595 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
10596 if (btrfs_root_readonly(root))
10597 return -EROFS;
10598 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
10599 return -EACCES;
10600 }
10601 return generic_permission(inode, mask);
10602 }
10603
10604 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
10605 {
10606 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
10607 struct btrfs_trans_handle *trans;
10608 struct btrfs_root *root = BTRFS_I(dir)->root;
10609 struct inode *inode = NULL;
10610 u64 objectid;
10611 u64 index;
10612 int ret = 0;
10613
10614 /*
10615 * 5 units required for adding orphan entry
10616 */
10617 trans = btrfs_start_transaction(root, 5);
10618 if (IS_ERR(trans))
10619 return PTR_ERR(trans);
10620
10621 ret = btrfs_find_free_ino(root, &objectid);
10622 if (ret)
10623 goto out;
10624
10625 inode = btrfs_new_inode(trans, root, dir, NULL, 0,
10626 btrfs_ino(BTRFS_I(dir)), objectid, mode, &index);
10627 if (IS_ERR(inode)) {
10628 ret = PTR_ERR(inode);
10629 inode = NULL;
10630 goto out;
10631 }
10632
10633 inode->i_fop = &btrfs_file_operations;
10634 inode->i_op = &btrfs_file_inode_operations;
10635
10636 inode->i_mapping->a_ops = &btrfs_aops;
10637 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10638
10639 ret = btrfs_init_inode_security(trans, inode, dir, NULL);
10640 if (ret)
10641 goto out_inode;
10642
10643 ret = btrfs_update_inode(trans, root, inode);
10644 if (ret)
10645 goto out_inode;
10646 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
10647 if (ret)
10648 goto out_inode;
10649
10650 /*
10651 * We set number of links to 0 in btrfs_new_inode(), and here we set
10652 * it to 1 because d_tmpfile() will issue a warning if the count is 0,
10653 * through:
10654 *
10655 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
10656 */
10657 set_nlink(inode, 1);
10658 unlock_new_inode(inode);
10659 d_tmpfile(dentry, inode);
10660 mark_inode_dirty(inode);
10661
10662 out:
10663 btrfs_end_transaction(trans);
10664 if (ret)
10665 iput(inode);
10666 btrfs_balance_delayed_items(fs_info);
10667 btrfs_btree_balance_dirty(fs_info);
10668 return ret;
10669
10670 out_inode:
10671 unlock_new_inode(inode);
10672 goto out;
10673
10674 }
10675
10676 __attribute__((const))
10677 static int btrfs_readpage_io_failed_hook(struct page *page, int failed_mirror)
10678 {
10679 return -EAGAIN;
10680 }
10681
10682 static struct btrfs_fs_info *iotree_fs_info(void *private_data)
10683 {
10684 struct inode *inode = private_data;
10685 return btrfs_sb(inode->i_sb);
10686 }
10687
10688 static void btrfs_check_extent_io_range(void *private_data, const char *caller,
10689 u64 start, u64 end)
10690 {
10691 struct inode *inode = private_data;
10692 u64 isize;
10693
10694 isize = i_size_read(inode);
10695 if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) {
10696 btrfs_debug_rl(BTRFS_I(inode)->root->fs_info,
10697 "%s: ino %llu isize %llu odd range [%llu,%llu]",
10698 caller, btrfs_ino(BTRFS_I(inode)), isize, start, end);
10699 }
10700 }
10701
10702 void btrfs_set_range_writeback(void *private_data, u64 start, u64 end)
10703 {
10704 struct inode *inode = private_data;
10705 unsigned long index = start >> PAGE_SHIFT;
10706 unsigned long end_index = end >> PAGE_SHIFT;
10707 struct page *page;
10708
10709 while (index <= end_index) {
10710 page = find_get_page(inode->i_mapping, index);
10711 ASSERT(page); /* Pages should be in the extent_io_tree */
10712 set_page_writeback(page);
10713 put_page(page);
10714 index++;
10715 }
10716 }
10717
10718 static const struct inode_operations btrfs_dir_inode_operations = {
10719 .getattr = btrfs_getattr,
10720 .lookup = btrfs_lookup,
10721 .create = btrfs_create,
10722 .unlink = btrfs_unlink,
10723 .link = btrfs_link,
10724 .mkdir = btrfs_mkdir,
10725 .rmdir = btrfs_rmdir,
10726 .rename = btrfs_rename2,
10727 .symlink = btrfs_symlink,
10728 .setattr = btrfs_setattr,
10729 .mknod = btrfs_mknod,
10730 .listxattr = btrfs_listxattr,
10731 .permission = btrfs_permission,
10732 .get_acl = btrfs_get_acl,
10733 .set_acl = btrfs_set_acl,
10734 .update_time = btrfs_update_time,
10735 .tmpfile = btrfs_tmpfile,
10736 };
10737 static const struct inode_operations btrfs_dir_ro_inode_operations = {
10738 .lookup = btrfs_lookup,
10739 .permission = btrfs_permission,
10740 .update_time = btrfs_update_time,
10741 };
10742
10743 static const struct file_operations btrfs_dir_file_operations = {
10744 .llseek = generic_file_llseek,
10745 .read = generic_read_dir,
10746 .iterate_shared = btrfs_real_readdir,
10747 .unlocked_ioctl = btrfs_ioctl,
10748 #ifdef CONFIG_COMPAT
10749 .compat_ioctl = btrfs_compat_ioctl,
10750 #endif
10751 .release = btrfs_release_file,
10752 .fsync = btrfs_sync_file,
10753 };
10754
10755 static const struct extent_io_ops btrfs_extent_io_ops = {
10756 /* mandatory callbacks */
10757 .submit_bio_hook = btrfs_submit_bio_hook,
10758 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
10759 .merge_bio_hook = btrfs_merge_bio_hook,
10760 .readpage_io_failed_hook = btrfs_readpage_io_failed_hook,
10761 .tree_fs_info = iotree_fs_info,
10762 .set_range_writeback = btrfs_set_range_writeback,
10763
10764 /* optional callbacks */
10765 .fill_delalloc = run_delalloc_range,
10766 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
10767 .writepage_start_hook = btrfs_writepage_start_hook,
10768 .set_bit_hook = btrfs_set_bit_hook,
10769 .clear_bit_hook = btrfs_clear_bit_hook,
10770 .merge_extent_hook = btrfs_merge_extent_hook,
10771 .split_extent_hook = btrfs_split_extent_hook,
10772 .check_extent_io_range = btrfs_check_extent_io_range,
10773 };
10774
10775 /*
10776 * btrfs doesn't support the bmap operation because swapfiles
10777 * use bmap to make a mapping of extents in the file. They assume
10778 * these extents won't change over the life of the file and they
10779 * use the bmap result to do IO directly to the drive.
10780 *
10781 * the btrfs bmap call would return logical addresses that aren't
10782 * suitable for IO and they also will change frequently as COW
10783 * operations happen. So, swapfile + btrfs == corruption.
10784 *
10785 * For now we're avoiding this by dropping bmap.
10786 */
10787 static const struct address_space_operations btrfs_aops = {
10788 .readpage = btrfs_readpage,
10789 .writepage = btrfs_writepage,
10790 .writepages = btrfs_writepages,
10791 .readpages = btrfs_readpages,
10792 .direct_IO = btrfs_direct_IO,
10793 .invalidatepage = btrfs_invalidatepage,
10794 .releasepage = btrfs_releasepage,
10795 .set_page_dirty = btrfs_set_page_dirty,
10796 .error_remove_page = generic_error_remove_page,
10797 };
10798
10799 static const struct address_space_operations btrfs_symlink_aops = {
10800 .readpage = btrfs_readpage,
10801 .writepage = btrfs_writepage,
10802 .invalidatepage = btrfs_invalidatepage,
10803 .releasepage = btrfs_releasepage,
10804 };
10805
10806 static const struct inode_operations btrfs_file_inode_operations = {
10807 .getattr = btrfs_getattr,
10808 .setattr = btrfs_setattr,
10809 .listxattr = btrfs_listxattr,
10810 .permission = btrfs_permission,
10811 .fiemap = btrfs_fiemap,
10812 .get_acl = btrfs_get_acl,
10813 .set_acl = btrfs_set_acl,
10814 .update_time = btrfs_update_time,
10815 };
10816 static const struct inode_operations btrfs_special_inode_operations = {
10817 .getattr = btrfs_getattr,
10818 .setattr = btrfs_setattr,
10819 .permission = btrfs_permission,
10820 .listxattr = btrfs_listxattr,
10821 .get_acl = btrfs_get_acl,
10822 .set_acl = btrfs_set_acl,
10823 .update_time = btrfs_update_time,
10824 };
10825 static const struct inode_operations btrfs_symlink_inode_operations = {
10826 .get_link = page_get_link,
10827 .getattr = btrfs_getattr,
10828 .setattr = btrfs_setattr,
10829 .permission = btrfs_permission,
10830 .listxattr = btrfs_listxattr,
10831 .update_time = btrfs_update_time,
10832 };
10833
10834 const struct dentry_operations btrfs_dentry_operations = {
10835 .d_delete = btrfs_dentry_delete,
10836 .d_release = btrfs_dentry_release,
10837 };
(deprecated) Btrfs devel tree