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Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm...
[linux-2.6.git] / fs / btrfs / inode.c
blobf1a77449d032b1fbd481eb16cd232653e5bfbefa
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/statfs.h>
34 #include <linux/compat.h>
35 #include <linux/aio.h>
36 #include <linux/bit_spinlock.h>
37 #include <linux/xattr.h>
38 #include <linux/posix_acl.h>
39 #include <linux/falloc.h>
40 #include <linux/slab.h>
41 #include <linux/ratelimit.h>
42 #include <linux/mount.h>
43 #include <linux/btrfs.h>
44 #include <linux/blkdev.h>
45 #include <linux/posix_acl_xattr.h>
46 #include "ctree.h"
47 #include "disk-io.h"
48 #include "transaction.h"
49 #include "btrfs_inode.h"
50 #include "print-tree.h"
51 #include "ordered-data.h"
52 #include "xattr.h"
53 #include "tree-log.h"
54 #include "volumes.h"
55 #include "compression.h"
56 #include "locking.h"
57 #include "free-space-cache.h"
58 #include "inode-map.h"
59 #include "backref.h"
60 #include "hash.h"
61
62 struct btrfs_iget_args {
63 u64 ino;
64 struct btrfs_root *root;
65 };
66
67 static const struct inode_operations btrfs_dir_inode_operations;
68 static const struct inode_operations btrfs_symlink_inode_operations;
69 static const struct inode_operations btrfs_dir_ro_inode_operations;
70 static const struct inode_operations btrfs_special_inode_operations;
71 static const struct inode_operations btrfs_file_inode_operations;
72 static const struct address_space_operations btrfs_aops;
73 static const struct address_space_operations btrfs_symlink_aops;
74 static const struct file_operations btrfs_dir_file_operations;
75 static struct extent_io_ops btrfs_extent_io_ops;
76
77 static struct kmem_cache *btrfs_inode_cachep;
78 static struct kmem_cache *btrfs_delalloc_work_cachep;
79 struct kmem_cache *btrfs_trans_handle_cachep;
80 struct kmem_cache *btrfs_transaction_cachep;
81 struct kmem_cache *btrfs_path_cachep;
82 struct kmem_cache *btrfs_free_space_cachep;
83
84 #define S_SHIFT 12
85 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
86 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
87 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
88 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
89 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
90 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
91 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
92 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
93 };
94
95 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
96 static int btrfs_truncate(struct inode *inode);
97 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
98 static noinline int cow_file_range(struct inode *inode,
99 struct page *locked_page,
100 u64 start, u64 end, int *page_started,
101 unsigned long *nr_written, int unlock);
102 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
103 u64 len, u64 orig_start,
104 u64 block_start, u64 block_len,
105 u64 orig_block_len, u64 ram_bytes,
106 int type);
107
108 static int btrfs_dirty_inode(struct inode *inode);
109
110 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
111 struct inode *inode, struct inode *dir,
112 const struct qstr *qstr)
113 {
114 int err;
115
116 err = btrfs_init_acl(trans, inode, dir);
117 if (!err)
118 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
119 return err;
120 }
121
122 /*
123 * this does all the hard work for inserting an inline extent into
124 * the btree. The caller should have done a btrfs_drop_extents so that
125 * no overlapping inline items exist in the btree
126 */
127 static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
128 struct btrfs_root *root, struct inode *inode,
129 u64 start, size_t size, size_t compressed_size,
130 int compress_type,
131 struct page **compressed_pages)
132 {
133 struct btrfs_key key;
134 struct btrfs_path *path;
135 struct extent_buffer *leaf;
136 struct page *page = NULL;
137 char *kaddr;
138 unsigned long ptr;
139 struct btrfs_file_extent_item *ei;
140 int err = 0;
141 int ret;
142 size_t cur_size = size;
143 size_t datasize;
144 unsigned long offset;
145
146 if (compressed_size && compressed_pages)
147 cur_size = compressed_size;
148
149 path = btrfs_alloc_path();
150 if (!path)
151 return -ENOMEM;
152
153 path->leave_spinning = 1;
154
155 key.objectid = btrfs_ino(inode);
156 key.offset = start;
157 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
158 datasize = btrfs_file_extent_calc_inline_size(cur_size);
159
160 inode_add_bytes(inode, size);
161 ret = btrfs_insert_empty_item(trans, root, path, &key,
162 datasize);
163 if (ret) {
164 err = ret;
165 goto fail;
166 }
167 leaf = path->nodes[0];
168 ei = btrfs_item_ptr(leaf, path->slots[0],
169 struct btrfs_file_extent_item);
170 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
171 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
172 btrfs_set_file_extent_encryption(leaf, ei, 0);
173 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
174 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
175 ptr = btrfs_file_extent_inline_start(ei);
176
177 if (compress_type != BTRFS_COMPRESS_NONE) {
178 struct page *cpage;
179 int i = 0;
180 while (compressed_size > 0) {
181 cpage = compressed_pages[i];
182 cur_size = min_t(unsigned long, compressed_size,
183 PAGE_CACHE_SIZE);
184
185 kaddr = kmap_atomic(cpage);
186 write_extent_buffer(leaf, kaddr, ptr, cur_size);
187 kunmap_atomic(kaddr);
188
189 i++;
190 ptr += cur_size;
191 compressed_size -= cur_size;
192 }
193 btrfs_set_file_extent_compression(leaf, ei,
194 compress_type);
195 } else {
196 page = find_get_page(inode->i_mapping,
197 start >> PAGE_CACHE_SHIFT);
198 btrfs_set_file_extent_compression(leaf, ei, 0);
199 kaddr = kmap_atomic(page);
200 offset = start & (PAGE_CACHE_SIZE - 1);
201 write_extent_buffer(leaf, kaddr + offset, ptr, size);
202 kunmap_atomic(kaddr);
203 page_cache_release(page);
204 }
205 btrfs_mark_buffer_dirty(leaf);
206 btrfs_free_path(path);
207
208 /*
209 * we're an inline extent, so nobody can
210 * extend the file past i_size without locking
211 * a page we already have locked.
212 *
213 * We must do any isize and inode updates
214 * before we unlock the pages. Otherwise we
215 * could end up racing with unlink.
216 */
217 BTRFS_I(inode)->disk_i_size = inode->i_size;
218 ret = btrfs_update_inode(trans, root, inode);
219
220 return ret;
221 fail:
222 btrfs_free_path(path);
223 return err;
224 }
225
226
227 /*
228 * conditionally insert an inline extent into the file. This
229 * does the checks required to make sure the data is small enough
230 * to fit as an inline extent.
231 */
232 static noinline int cow_file_range_inline(struct btrfs_root *root,
233 struct inode *inode, u64 start,
234 u64 end, size_t compressed_size,
235 int compress_type,
236 struct page **compressed_pages)
237 {
238 struct btrfs_trans_handle *trans;
239 u64 isize = i_size_read(inode);
240 u64 actual_end = min(end + 1, isize);
241 u64 inline_len = actual_end - start;
242 u64 aligned_end = ALIGN(end, root->sectorsize);
243 u64 data_len = inline_len;
244 int ret;
245
246 if (compressed_size)
247 data_len = compressed_size;
248
249 if (start > 0 ||
250 actual_end >= PAGE_CACHE_SIZE ||
251 data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
252 (!compressed_size &&
253 (actual_end & (root->sectorsize - 1)) == 0) ||
254 end + 1 < isize ||
255 data_len > root->fs_info->max_inline) {
256 return 1;
257 }
258
259 trans = btrfs_join_transaction(root);
260 if (IS_ERR(trans))
261 return PTR_ERR(trans);
262 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
263
264 ret = btrfs_drop_extents(trans, root, inode, start, aligned_end, 1);
265 if (ret) {
266 btrfs_abort_transaction(trans, root, ret);
267 goto out;
268 }
269
270 if (isize > actual_end)
271 inline_len = min_t(u64, isize, actual_end);
272 ret = insert_inline_extent(trans, root, inode, start,
273 inline_len, compressed_size,
274 compress_type, compressed_pages);
275 if (ret && ret != -ENOSPC) {
276 btrfs_abort_transaction(trans, root, ret);
277 goto out;
278 } else if (ret == -ENOSPC) {
279 ret = 1;
280 goto out;
281 }
282
283 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
284 btrfs_delalloc_release_metadata(inode, end + 1 - start);
285 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
286 out:
287 btrfs_end_transaction(trans, root);
288 return ret;
289 }
290
291 struct async_extent {
292 u64 start;
293 u64 ram_size;
294 u64 compressed_size;
295 struct page **pages;
296 unsigned long nr_pages;
297 int compress_type;
298 struct list_head list;
299 };
300
301 struct async_cow {
302 struct inode *inode;
303 struct btrfs_root *root;
304 struct page *locked_page;
305 u64 start;
306 u64 end;
307 struct list_head extents;
308 struct btrfs_work work;
309 };
310
311 static noinline int add_async_extent(struct async_cow *cow,
312 u64 start, u64 ram_size,
313 u64 compressed_size,
314 struct page **pages,
315 unsigned long nr_pages,
316 int compress_type)
317 {
318 struct async_extent *async_extent;
319
320 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
321 BUG_ON(!async_extent); /* -ENOMEM */
322 async_extent->start = start;
323 async_extent->ram_size = ram_size;
324 async_extent->compressed_size = compressed_size;
325 async_extent->pages = pages;
326 async_extent->nr_pages = nr_pages;
327 async_extent->compress_type = compress_type;
328 list_add_tail(&async_extent->list, &cow->extents);
329 return 0;
330 }
331
332 /*
333 * we create compressed extents in two phases. The first
334 * phase compresses a range of pages that have already been
335 * locked (both pages and state bits are locked).
336 *
337 * This is done inside an ordered work queue, and the compression
338 * is spread across many cpus. The actual IO submission is step
339 * two, and the ordered work queue takes care of making sure that
340 * happens in the same order things were put onto the queue by
341 * writepages and friends.
342 *
343 * If this code finds it can't get good compression, it puts an
344 * entry onto the work queue to write the uncompressed bytes. This
345 * makes sure that both compressed inodes and uncompressed inodes
346 * are written in the same order that the flusher thread sent them
347 * down.
348 */
349 static noinline int compress_file_range(struct inode *inode,
350 struct page *locked_page,
351 u64 start, u64 end,
352 struct async_cow *async_cow,
353 int *num_added)
354 {
355 struct btrfs_root *root = BTRFS_I(inode)->root;
356 u64 num_bytes;
357 u64 blocksize = root->sectorsize;
358 u64 actual_end;
359 u64 isize = i_size_read(inode);
360 int ret = 0;
361 struct page **pages = NULL;
362 unsigned long nr_pages;
363 unsigned long nr_pages_ret = 0;
364 unsigned long total_compressed = 0;
365 unsigned long total_in = 0;
366 unsigned long max_compressed = 128 * 1024;
367 unsigned long max_uncompressed = 128 * 1024;
368 int i;
369 int will_compress;
370 int compress_type = root->fs_info->compress_type;
371 int redirty = 0;
372
373 /* if this is a small write inside eof, kick off a defrag */
374 if ((end - start + 1) < 16 * 1024 &&
375 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
376 btrfs_add_inode_defrag(NULL, inode);
377
378 actual_end = min_t(u64, isize, end + 1);
379 again:
380 will_compress = 0;
381 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
382 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
383
384 /*
385 * we don't want to send crud past the end of i_size through
386 * compression, that's just a waste of CPU time. So, if the
387 * end of the file is before the start of our current
388 * requested range of bytes, we bail out to the uncompressed
389 * cleanup code that can deal with all of this.
390 *
391 * It isn't really the fastest way to fix things, but this is a
392 * very uncommon corner.
393 */
394 if (actual_end <= start)
395 goto cleanup_and_bail_uncompressed;
396
397 total_compressed = actual_end - start;
398
399 /* we want to make sure that amount of ram required to uncompress
400 * an extent is reasonable, so we limit the total size in ram
401 * of a compressed extent to 128k. This is a crucial number
402 * because it also controls how easily we can spread reads across
403 * cpus for decompression.
404 *
405 * We also want to make sure the amount of IO required to do
406 * a random read is reasonably small, so we limit the size of
407 * a compressed extent to 128k.
408 */
409 total_compressed = min(total_compressed, max_uncompressed);
410 num_bytes = ALIGN(end - start + 1, blocksize);
411 num_bytes = max(blocksize, num_bytes);
412 total_in = 0;
413 ret = 0;
414
415 /*
416 * we do compression for mount -o compress and when the
417 * inode has not been flagged as nocompress. This flag can
418 * change at any time if we discover bad compression ratios.
419 */
420 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) &&
421 (btrfs_test_opt(root, COMPRESS) ||
422 (BTRFS_I(inode)->force_compress) ||
423 (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) {
424 WARN_ON(pages);
425 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
426 if (!pages) {
427 /* just bail out to the uncompressed code */
428 goto cont;
429 }
430
431 if (BTRFS_I(inode)->force_compress)
432 compress_type = BTRFS_I(inode)->force_compress;
433
434 /*
435 * we need to call clear_page_dirty_for_io on each
436 * page in the range. Otherwise applications with the file
437 * mmap'd can wander in and change the page contents while
438 * we are compressing them.
439 *
440 * If the compression fails for any reason, we set the pages
441 * dirty again later on.
442 */
443 extent_range_clear_dirty_for_io(inode, start, end);
444 redirty = 1;
445 ret = btrfs_compress_pages(compress_type,
446 inode->i_mapping, start,
447 total_compressed, pages,
448 nr_pages, &nr_pages_ret,
449 &total_in,
450 &total_compressed,
451 max_compressed);
452
453 if (!ret) {
454 unsigned long offset = total_compressed &
455 (PAGE_CACHE_SIZE - 1);
456 struct page *page = pages[nr_pages_ret - 1];
457 char *kaddr;
458
459 /* zero the tail end of the last page, we might be
460 * sending it down to disk
461 */
462 if (offset) {
463 kaddr = kmap_atomic(page);
464 memset(kaddr + offset, 0,
465 PAGE_CACHE_SIZE - offset);
466 kunmap_atomic(kaddr);
467 }
468 will_compress = 1;
469 }
470 }
471 cont:
472 if (start == 0) {
473 /* lets try to make an inline extent */
474 if (ret || total_in < (actual_end - start)) {
475 /* we didn't compress the entire range, try
476 * to make an uncompressed inline extent.
477 */
478 ret = cow_file_range_inline(root, inode, start, end,
479 0, 0, NULL);
480 } else {
481 /* try making a compressed inline extent */
482 ret = cow_file_range_inline(root, inode, start, end,
483 total_compressed,
484 compress_type, pages);
485 }
486 if (ret <= 0) {
487 unsigned long clear_flags = EXTENT_DELALLOC |
488 EXTENT_DEFRAG;
489 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0;
490
491 /*
492 * inline extent creation worked or returned error,
493 * we don't need to create any more async work items.
494 * Unlock and free up our temp pages.
495 */
496 extent_clear_unlock_delalloc(inode, start, end, NULL,
497 clear_flags, PAGE_UNLOCK |
498 PAGE_CLEAR_DIRTY |
499 PAGE_SET_WRITEBACK |
500 PAGE_END_WRITEBACK);
501 goto free_pages_out;
502 }
503 }
504
505 if (will_compress) {
506 /*
507 * we aren't doing an inline extent round the compressed size
508 * up to a block size boundary so the allocator does sane
509 * things
510 */
511 total_compressed = ALIGN(total_compressed, blocksize);
512
513 /*
514 * one last check to make sure the compression is really a
515 * win, compare the page count read with the blocks on disk
516 */
517 total_in = ALIGN(total_in, PAGE_CACHE_SIZE);
518 if (total_compressed >= total_in) {
519 will_compress = 0;
520 } else {
521 num_bytes = total_in;
522 }
523 }
524 if (!will_compress && pages) {
525 /*
526 * the compression code ran but failed to make things smaller,
527 * free any pages it allocated and our page pointer array
528 */
529 for (i = 0; i < nr_pages_ret; i++) {
530 WARN_ON(pages[i]->mapping);
531 page_cache_release(pages[i]);
532 }
533 kfree(pages);
534 pages = NULL;
535 total_compressed = 0;
536 nr_pages_ret = 0;
537
538 /* flag the file so we don't compress in the future */
539 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
540 !(BTRFS_I(inode)->force_compress)) {
541 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
542 }
543 }
544 if (will_compress) {
545 *num_added += 1;
546
547 /* the async work queues will take care of doing actual
548 * allocation on disk for these compressed pages,
549 * and will submit them to the elevator.
550 */
551 add_async_extent(async_cow, start, num_bytes,
552 total_compressed, pages, nr_pages_ret,
553 compress_type);
554
555 if (start + num_bytes < end) {
556 start += num_bytes;
557 pages = NULL;
558 cond_resched();
559 goto again;
560 }
561 } else {
562 cleanup_and_bail_uncompressed:
563 /*
564 * No compression, but we still need to write the pages in
565 * the file we've been given so far. redirty the locked
566 * page if it corresponds to our extent and set things up
567 * for the async work queue to run cow_file_range to do
568 * the normal delalloc dance
569 */
570 if (page_offset(locked_page) >= start &&
571 page_offset(locked_page) <= end) {
572 __set_page_dirty_nobuffers(locked_page);
573 /* unlocked later on in the async handlers */
574 }
575 if (redirty)
576 extent_range_redirty_for_io(inode, start, end);
577 add_async_extent(async_cow, start, end - start + 1,
578 0, NULL, 0, BTRFS_COMPRESS_NONE);
579 *num_added += 1;
580 }
581
582 out:
583 return ret;
584
585 free_pages_out:
586 for (i = 0; i < nr_pages_ret; i++) {
587 WARN_ON(pages[i]->mapping);
588 page_cache_release(pages[i]);
589 }
590 kfree(pages);
591
592 goto out;
593 }
594
595 /*
596 * phase two of compressed writeback. This is the ordered portion
597 * of the code, which only gets called in the order the work was
598 * queued. We walk all the async extents created by compress_file_range
599 * and send them down to the disk.
600 */
601 static noinline int submit_compressed_extents(struct inode *inode,
602 struct async_cow *async_cow)
603 {
604 struct async_extent *async_extent;
605 u64 alloc_hint = 0;
606 struct btrfs_key ins;
607 struct extent_map *em;
608 struct btrfs_root *root = BTRFS_I(inode)->root;
609 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
610 struct extent_io_tree *io_tree;
611 int ret = 0;
612
613 if (list_empty(&async_cow->extents))
614 return 0;
615
616 again:
617 while (!list_empty(&async_cow->extents)) {
618 async_extent = list_entry(async_cow->extents.next,
619 struct async_extent, list);
620 list_del(&async_extent->list);
621
622 io_tree = &BTRFS_I(inode)->io_tree;
623
624 retry:
625 /* did the compression code fall back to uncompressed IO? */
626 if (!async_extent->pages) {
627 int page_started = 0;
628 unsigned long nr_written = 0;
629
630 lock_extent(io_tree, async_extent->start,
631 async_extent->start +
632 async_extent->ram_size - 1);
633
634 /* allocate blocks */
635 ret = cow_file_range(inode, async_cow->locked_page,
636 async_extent->start,
637 async_extent->start +
638 async_extent->ram_size - 1,
639 &page_started, &nr_written, 0);
640
641 /* JDM XXX */
642
643 /*
644 * if page_started, cow_file_range inserted an
645 * inline extent and took care of all the unlocking
646 * and IO for us. Otherwise, we need to submit
647 * all those pages down to the drive.
648 */
649 if (!page_started && !ret)
650 extent_write_locked_range(io_tree,
651 inode, async_extent->start,
652 async_extent->start +
653 async_extent->ram_size - 1,
654 btrfs_get_extent,
655 WB_SYNC_ALL);
656 else if (ret)
657 unlock_page(async_cow->locked_page);
658 kfree(async_extent);
659 cond_resched();
660 continue;
661 }
662
663 lock_extent(io_tree, async_extent->start,
664 async_extent->start + async_extent->ram_size - 1);
665
666 ret = btrfs_reserve_extent(root,
667 async_extent->compressed_size,
668 async_extent->compressed_size,
669 0, alloc_hint, &ins, 1);
670 if (ret) {
671 int i;
672
673 for (i = 0; i < async_extent->nr_pages; i++) {
674 WARN_ON(async_extent->pages[i]->mapping);
675 page_cache_release(async_extent->pages[i]);
676 }
677 kfree(async_extent->pages);
678 async_extent->nr_pages = 0;
679 async_extent->pages = NULL;
680
681 if (ret == -ENOSPC) {
682 unlock_extent(io_tree, async_extent->start,
683 async_extent->start +
684 async_extent->ram_size - 1);
685 goto retry;
686 }
687 goto out_free;
688 }
689
690 /*
691 * here we're doing allocation and writeback of the
692 * compressed pages
693 */
694 btrfs_drop_extent_cache(inode, async_extent->start,
695 async_extent->start +
696 async_extent->ram_size - 1, 0);
697
698 em = alloc_extent_map();
699 if (!em) {
700 ret = -ENOMEM;
701 goto out_free_reserve;
702 }
703 em->start = async_extent->start;
704 em->len = async_extent->ram_size;
705 em->orig_start = em->start;
706 em->mod_start = em->start;
707 em->mod_len = em->len;
708
709 em->block_start = ins.objectid;
710 em->block_len = ins.offset;
711 em->orig_block_len = ins.offset;
712 em->ram_bytes = async_extent->ram_size;
713 em->bdev = root->fs_info->fs_devices->latest_bdev;
714 em->compress_type = async_extent->compress_type;
715 set_bit(EXTENT_FLAG_PINNED, &em->flags);
716 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
717 em->generation = -1;
718
719 while (1) {
720 write_lock(&em_tree->lock);
721 ret = add_extent_mapping(em_tree, em, 1);
722 write_unlock(&em_tree->lock);
723 if (ret != -EEXIST) {
724 free_extent_map(em);
725 break;
726 }
727 btrfs_drop_extent_cache(inode, async_extent->start,
728 async_extent->start +
729 async_extent->ram_size - 1, 0);
730 }
731
732 if (ret)
733 goto out_free_reserve;
734
735 ret = btrfs_add_ordered_extent_compress(inode,
736 async_extent->start,
737 ins.objectid,
738 async_extent->ram_size,
739 ins.offset,
740 BTRFS_ORDERED_COMPRESSED,
741 async_extent->compress_type);
742 if (ret)
743 goto out_free_reserve;
744
745 /*
746 * clear dirty, set writeback and unlock the pages.
747 */
748 extent_clear_unlock_delalloc(inode, async_extent->start,
749 async_extent->start +
750 async_extent->ram_size - 1,
751 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
752 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
753 PAGE_SET_WRITEBACK);
754 ret = btrfs_submit_compressed_write(inode,
755 async_extent->start,
756 async_extent->ram_size,
757 ins.objectid,
758 ins.offset, async_extent->pages,
759 async_extent->nr_pages);
760 alloc_hint = ins.objectid + ins.offset;
761 kfree(async_extent);
762 if (ret)
763 goto out;
764 cond_resched();
765 }
766 ret = 0;
767 out:
768 return ret;
769 out_free_reserve:
770 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
771 out_free:
772 extent_clear_unlock_delalloc(inode, async_extent->start,
773 async_extent->start +
774 async_extent->ram_size - 1,
775 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
776 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
777 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
778 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
779 kfree(async_extent);
780 goto again;
781 }
782
783 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
784 u64 num_bytes)
785 {
786 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
787 struct extent_map *em;
788 u64 alloc_hint = 0;
789
790 read_lock(&em_tree->lock);
791 em = search_extent_mapping(em_tree, start, num_bytes);
792 if (em) {
793 /*
794 * if block start isn't an actual block number then find the
795 * first block in this inode and use that as a hint. If that
796 * block is also bogus then just don't worry about it.
797 */
798 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
799 free_extent_map(em);
800 em = search_extent_mapping(em_tree, 0, 0);
801 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
802 alloc_hint = em->block_start;
803 if (em)
804 free_extent_map(em);
805 } else {
806 alloc_hint = em->block_start;
807 free_extent_map(em);
808 }
809 }
810 read_unlock(&em_tree->lock);
811
812 return alloc_hint;
813 }
814
815 /*
816 * when extent_io.c finds a delayed allocation range in the file,
817 * the call backs end up in this code. The basic idea is to
818 * allocate extents on disk for the range, and create ordered data structs
819 * in ram to track those extents.
820 *
821 * locked_page is the page that writepage had locked already. We use
822 * it to make sure we don't do extra locks or unlocks.
823 *
824 * *page_started is set to one if we unlock locked_page and do everything
825 * required to start IO on it. It may be clean and already done with
826 * IO when we return.
827 */
828 static noinline int cow_file_range(struct inode *inode,
829 struct page *locked_page,
830 u64 start, u64 end, int *page_started,
831 unsigned long *nr_written,
832 int unlock)
833 {
834 struct btrfs_root *root = BTRFS_I(inode)->root;
835 u64 alloc_hint = 0;
836 u64 num_bytes;
837 unsigned long ram_size;
838 u64 disk_num_bytes;
839 u64 cur_alloc_size;
840 u64 blocksize = root->sectorsize;
841 struct btrfs_key ins;
842 struct extent_map *em;
843 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
844 int ret = 0;
845
846 if (btrfs_is_free_space_inode(inode)) {
847 WARN_ON_ONCE(1);
848 return -EINVAL;
849 }
850
851 num_bytes = ALIGN(end - start + 1, blocksize);
852 num_bytes = max(blocksize, num_bytes);
853 disk_num_bytes = num_bytes;
854
855 /* if this is a small write inside eof, kick off defrag */
856 if (num_bytes < 64 * 1024 &&
857 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
858 btrfs_add_inode_defrag(NULL, inode);
859
860 if (start == 0) {
861 /* lets try to make an inline extent */
862 ret = cow_file_range_inline(root, inode, start, end, 0, 0,
863 NULL);
864 if (ret == 0) {
865 extent_clear_unlock_delalloc(inode, start, end, NULL,
866 EXTENT_LOCKED | EXTENT_DELALLOC |
867 EXTENT_DEFRAG, PAGE_UNLOCK |
868 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
869 PAGE_END_WRITEBACK);
870
871 *nr_written = *nr_written +
872 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
873 *page_started = 1;
874 goto out;
875 } else if (ret < 0) {
876 goto out_unlock;
877 }
878 }
879
880 BUG_ON(disk_num_bytes >
881 btrfs_super_total_bytes(root->fs_info->super_copy));
882
883 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
884 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
885
886 while (disk_num_bytes > 0) {
887 unsigned long op;
888
889 cur_alloc_size = disk_num_bytes;
890 ret = btrfs_reserve_extent(root, cur_alloc_size,
891 root->sectorsize, 0, alloc_hint,
892 &ins, 1);
893 if (ret < 0)
894 goto out_unlock;
895
896 em = alloc_extent_map();
897 if (!em) {
898 ret = -ENOMEM;
899 goto out_reserve;
900 }
901 em->start = start;
902 em->orig_start = em->start;
903 ram_size = ins.offset;
904 em->len = ins.offset;
905 em->mod_start = em->start;
906 em->mod_len = em->len;
907
908 em->block_start = ins.objectid;
909 em->block_len = ins.offset;
910 em->orig_block_len = ins.offset;
911 em->ram_bytes = ram_size;
912 em->bdev = root->fs_info->fs_devices->latest_bdev;
913 set_bit(EXTENT_FLAG_PINNED, &em->flags);
914 em->generation = -1;
915
916 while (1) {
917 write_lock(&em_tree->lock);
918 ret = add_extent_mapping(em_tree, em, 1);
919 write_unlock(&em_tree->lock);
920 if (ret != -EEXIST) {
921 free_extent_map(em);
922 break;
923 }
924 btrfs_drop_extent_cache(inode, start,
925 start + ram_size - 1, 0);
926 }
927 if (ret)
928 goto out_reserve;
929
930 cur_alloc_size = ins.offset;
931 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
932 ram_size, cur_alloc_size, 0);
933 if (ret)
934 goto out_reserve;
935
936 if (root->root_key.objectid ==
937 BTRFS_DATA_RELOC_TREE_OBJECTID) {
938 ret = btrfs_reloc_clone_csums(inode, start,
939 cur_alloc_size);
940 if (ret)
941 goto out_reserve;
942 }
943
944 if (disk_num_bytes < cur_alloc_size)
945 break;
946
947 /* we're not doing compressed IO, don't unlock the first
948 * page (which the caller expects to stay locked), don't
949 * clear any dirty bits and don't set any writeback bits
950 *
951 * Do set the Private2 bit so we know this page was properly
952 * setup for writepage
953 */
954 op = unlock ? PAGE_UNLOCK : 0;
955 op |= PAGE_SET_PRIVATE2;
956
957 extent_clear_unlock_delalloc(inode, start,
958 start + ram_size - 1, locked_page,
959 EXTENT_LOCKED | EXTENT_DELALLOC,
960 op);
961 disk_num_bytes -= cur_alloc_size;
962 num_bytes -= cur_alloc_size;
963 alloc_hint = ins.objectid + ins.offset;
964 start += cur_alloc_size;
965 }
966 out:
967 return ret;
968
969 out_reserve:
970 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
971 out_unlock:
972 extent_clear_unlock_delalloc(inode, start, end, locked_page,
973 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
974 EXTENT_DELALLOC | EXTENT_DEFRAG,
975 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
976 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
977 goto out;
978 }
979
980 /*
981 * work queue call back to started compression on a file and pages
982 */
983 static noinline void async_cow_start(struct btrfs_work *work)
984 {
985 struct async_cow *async_cow;
986 int num_added = 0;
987 async_cow = container_of(work, struct async_cow, work);
988
989 compress_file_range(async_cow->inode, async_cow->locked_page,
990 async_cow->start, async_cow->end, async_cow,
991 &num_added);
992 if (num_added == 0) {
993 btrfs_add_delayed_iput(async_cow->inode);
994 async_cow->inode = NULL;
995 }
996 }
997
998 /*
999 * work queue call back to submit previously compressed pages
1000 */
1001 static noinline void async_cow_submit(struct btrfs_work *work)
1002 {
1003 struct async_cow *async_cow;
1004 struct btrfs_root *root;
1005 unsigned long nr_pages;
1006
1007 async_cow = container_of(work, struct async_cow, work);
1008
1009 root = async_cow->root;
1010 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
1011 PAGE_CACHE_SHIFT;
1012
1013 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1014 5 * 1024 * 1024 &&
1015 waitqueue_active(&root->fs_info->async_submit_wait))
1016 wake_up(&root->fs_info->async_submit_wait);
1017
1018 if (async_cow->inode)
1019 submit_compressed_extents(async_cow->inode, async_cow);
1020 }
1021
1022 static noinline void async_cow_free(struct btrfs_work *work)
1023 {
1024 struct async_cow *async_cow;
1025 async_cow = container_of(work, struct async_cow, work);
1026 if (async_cow->inode)
1027 btrfs_add_delayed_iput(async_cow->inode);
1028 kfree(async_cow);
1029 }
1030
1031 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1032 u64 start, u64 end, int *page_started,
1033 unsigned long *nr_written)
1034 {
1035 struct async_cow *async_cow;
1036 struct btrfs_root *root = BTRFS_I(inode)->root;
1037 unsigned long nr_pages;
1038 u64 cur_end;
1039 int limit = 10 * 1024 * 1024;
1040
1041 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1042 1, 0, NULL, GFP_NOFS);
1043 while (start < end) {
1044 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1045 BUG_ON(!async_cow); /* -ENOMEM */
1046 async_cow->inode = igrab(inode);
1047 async_cow->root = root;
1048 async_cow->locked_page = locked_page;
1049 async_cow->start = start;
1050
1051 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
1052 cur_end = end;
1053 else
1054 cur_end = min(end, start + 512 * 1024 - 1);
1055
1056 async_cow->end = cur_end;
1057 INIT_LIST_HEAD(&async_cow->extents);
1058
1059 async_cow->work.func = async_cow_start;
1060 async_cow->work.ordered_func = async_cow_submit;
1061 async_cow->work.ordered_free = async_cow_free;
1062 async_cow->work.flags = 0;
1063
1064 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
1065 PAGE_CACHE_SHIFT;
1066 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1067
1068 btrfs_queue_worker(&root->fs_info->delalloc_workers,
1069 &async_cow->work);
1070
1071 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1072 wait_event(root->fs_info->async_submit_wait,
1073 (atomic_read(&root->fs_info->async_delalloc_pages) <
1074 limit));
1075 }
1076
1077 while (atomic_read(&root->fs_info->async_submit_draining) &&
1078 atomic_read(&root->fs_info->async_delalloc_pages)) {
1079 wait_event(root->fs_info->async_submit_wait,
1080 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1081 0));
1082 }
1083
1084 *nr_written += nr_pages;
1085 start = cur_end + 1;
1086 }
1087 *page_started = 1;
1088 return 0;
1089 }
1090
1091 static noinline int csum_exist_in_range(struct btrfs_root *root,
1092 u64 bytenr, u64 num_bytes)
1093 {
1094 int ret;
1095 struct btrfs_ordered_sum *sums;
1096 LIST_HEAD(list);
1097
1098 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1099 bytenr + num_bytes - 1, &list, 0);
1100 if (ret == 0 && list_empty(&list))
1101 return 0;
1102
1103 while (!list_empty(&list)) {
1104 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1105 list_del(&sums->list);
1106 kfree(sums);
1107 }
1108 return 1;
1109 }
1110
1111 /*
1112 * when nowcow writeback call back. This checks for snapshots or COW copies
1113 * of the extents that exist in the file, and COWs the file as required.
1114 *
1115 * If no cow copies or snapshots exist, we write directly to the existing
1116 * blocks on disk
1117 */
1118 static noinline int run_delalloc_nocow(struct inode *inode,
1119 struct page *locked_page,
1120 u64 start, u64 end, int *page_started, int force,
1121 unsigned long *nr_written)
1122 {
1123 struct btrfs_root *root = BTRFS_I(inode)->root;
1124 struct btrfs_trans_handle *trans;
1125 struct extent_buffer *leaf;
1126 struct btrfs_path *path;
1127 struct btrfs_file_extent_item *fi;
1128 struct btrfs_key found_key;
1129 u64 cow_start;
1130 u64 cur_offset;
1131 u64 extent_end;
1132 u64 extent_offset;
1133 u64 disk_bytenr;
1134 u64 num_bytes;
1135 u64 disk_num_bytes;
1136 u64 ram_bytes;
1137 int extent_type;
1138 int ret, err;
1139 int type;
1140 int nocow;
1141 int check_prev = 1;
1142 bool nolock;
1143 u64 ino = btrfs_ino(inode);
1144
1145 path = btrfs_alloc_path();
1146 if (!path) {
1147 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1148 EXTENT_LOCKED | EXTENT_DELALLOC |
1149 EXTENT_DO_ACCOUNTING |
1150 EXTENT_DEFRAG, PAGE_UNLOCK |
1151 PAGE_CLEAR_DIRTY |
1152 PAGE_SET_WRITEBACK |
1153 PAGE_END_WRITEBACK);
1154 return -ENOMEM;
1155 }
1156
1157 nolock = btrfs_is_free_space_inode(inode);
1158
1159 if (nolock)
1160 trans = btrfs_join_transaction_nolock(root);
1161 else
1162 trans = btrfs_join_transaction(root);
1163
1164 if (IS_ERR(trans)) {
1165 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1166 EXTENT_LOCKED | EXTENT_DELALLOC |
1167 EXTENT_DO_ACCOUNTING |
1168 EXTENT_DEFRAG, PAGE_UNLOCK |
1169 PAGE_CLEAR_DIRTY |
1170 PAGE_SET_WRITEBACK |
1171 PAGE_END_WRITEBACK);
1172 btrfs_free_path(path);
1173 return PTR_ERR(trans);
1174 }
1175
1176 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1177
1178 cow_start = (u64)-1;
1179 cur_offset = start;
1180 while (1) {
1181 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1182 cur_offset, 0);
1183 if (ret < 0)
1184 goto error;
1185 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1186 leaf = path->nodes[0];
1187 btrfs_item_key_to_cpu(leaf, &found_key,
1188 path->slots[0] - 1);
1189 if (found_key.objectid == ino &&
1190 found_key.type == BTRFS_EXTENT_DATA_KEY)
1191 path->slots[0]--;
1192 }
1193 check_prev = 0;
1194 next_slot:
1195 leaf = path->nodes[0];
1196 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1197 ret = btrfs_next_leaf(root, path);
1198 if (ret < 0)
1199 goto error;
1200 if (ret > 0)
1201 break;
1202 leaf = path->nodes[0];
1203 }
1204
1205 nocow = 0;
1206 disk_bytenr = 0;
1207 num_bytes = 0;
1208 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1209
1210 if (found_key.objectid > ino ||
1211 found_key.type > BTRFS_EXTENT_DATA_KEY ||
1212 found_key.offset > end)
1213 break;
1214
1215 if (found_key.offset > cur_offset) {
1216 extent_end = found_key.offset;
1217 extent_type = 0;
1218 goto out_check;
1219 }
1220
1221 fi = btrfs_item_ptr(leaf, path->slots[0],
1222 struct btrfs_file_extent_item);
1223 extent_type = btrfs_file_extent_type(leaf, fi);
1224
1225 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1226 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1227 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1228 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1229 extent_offset = btrfs_file_extent_offset(leaf, fi);
1230 extent_end = found_key.offset +
1231 btrfs_file_extent_num_bytes(leaf, fi);
1232 disk_num_bytes =
1233 btrfs_file_extent_disk_num_bytes(leaf, fi);
1234 if (extent_end <= start) {
1235 path->slots[0]++;
1236 goto next_slot;
1237 }
1238 if (disk_bytenr == 0)
1239 goto out_check;
1240 if (btrfs_file_extent_compression(leaf, fi) ||
1241 btrfs_file_extent_encryption(leaf, fi) ||
1242 btrfs_file_extent_other_encoding(leaf, fi))
1243 goto out_check;
1244 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1245 goto out_check;
1246 if (btrfs_extent_readonly(root, disk_bytenr))
1247 goto out_check;
1248 if (btrfs_cross_ref_exist(trans, root, ino,
1249 found_key.offset -
1250 extent_offset, disk_bytenr))
1251 goto out_check;
1252 disk_bytenr += extent_offset;
1253 disk_bytenr += cur_offset - found_key.offset;
1254 num_bytes = min(end + 1, extent_end) - cur_offset;
1255 /*
1256 * force cow if csum exists in the range.
1257 * this ensure that csum for a given extent are
1258 * either valid or do not exist.
1259 */
1260 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1261 goto out_check;
1262 nocow = 1;
1263 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1264 extent_end = found_key.offset +
1265 btrfs_file_extent_inline_len(leaf, fi);
1266 extent_end = ALIGN(extent_end, root->sectorsize);
1267 } else {
1268 BUG_ON(1);
1269 }
1270 out_check:
1271 if (extent_end <= start) {
1272 path->slots[0]++;
1273 goto next_slot;
1274 }
1275 if (!nocow) {
1276 if (cow_start == (u64)-1)
1277 cow_start = cur_offset;
1278 cur_offset = extent_end;
1279 if (cur_offset > end)
1280 break;
1281 path->slots[0]++;
1282 goto next_slot;
1283 }
1284
1285 btrfs_release_path(path);
1286 if (cow_start != (u64)-1) {
1287 ret = cow_file_range(inode, locked_page,
1288 cow_start, found_key.offset - 1,
1289 page_started, nr_written, 1);
1290 if (ret)
1291 goto error;
1292 cow_start = (u64)-1;
1293 }
1294
1295 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1296 struct extent_map *em;
1297 struct extent_map_tree *em_tree;
1298 em_tree = &BTRFS_I(inode)->extent_tree;
1299 em = alloc_extent_map();
1300 BUG_ON(!em); /* -ENOMEM */
1301 em->start = cur_offset;
1302 em->orig_start = found_key.offset - extent_offset;
1303 em->len = num_bytes;
1304 em->block_len = num_bytes;
1305 em->block_start = disk_bytenr;
1306 em->orig_block_len = disk_num_bytes;
1307 em->ram_bytes = ram_bytes;
1308 em->bdev = root->fs_info->fs_devices->latest_bdev;
1309 em->mod_start = em->start;
1310 em->mod_len = em->len;
1311 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1312 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1313 em->generation = -1;
1314 while (1) {
1315 write_lock(&em_tree->lock);
1316 ret = add_extent_mapping(em_tree, em, 1);
1317 write_unlock(&em_tree->lock);
1318 if (ret != -EEXIST) {
1319 free_extent_map(em);
1320 break;
1321 }
1322 btrfs_drop_extent_cache(inode, em->start,
1323 em->start + em->len - 1, 0);
1324 }
1325 type = BTRFS_ORDERED_PREALLOC;
1326 } else {
1327 type = BTRFS_ORDERED_NOCOW;
1328 }
1329
1330 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1331 num_bytes, num_bytes, type);
1332 BUG_ON(ret); /* -ENOMEM */
1333
1334 if (root->root_key.objectid ==
1335 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1336 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1337 num_bytes);
1338 if (ret)
1339 goto error;
1340 }
1341
1342 extent_clear_unlock_delalloc(inode, cur_offset,
1343 cur_offset + num_bytes - 1,
1344 locked_page, EXTENT_LOCKED |
1345 EXTENT_DELALLOC, PAGE_UNLOCK |
1346 PAGE_SET_PRIVATE2);
1347 cur_offset = extent_end;
1348 if (cur_offset > end)
1349 break;
1350 }
1351 btrfs_release_path(path);
1352
1353 if (cur_offset <= end && cow_start == (u64)-1) {
1354 cow_start = cur_offset;
1355 cur_offset = end;
1356 }
1357
1358 if (cow_start != (u64)-1) {
1359 ret = cow_file_range(inode, locked_page, cow_start, end,
1360 page_started, nr_written, 1);
1361 if (ret)
1362 goto error;
1363 }
1364
1365 error:
1366 err = btrfs_end_transaction(trans, root);
1367 if (!ret)
1368 ret = err;
1369
1370 if (ret && cur_offset < end)
1371 extent_clear_unlock_delalloc(inode, cur_offset, end,
1372 locked_page, EXTENT_LOCKED |
1373 EXTENT_DELALLOC | EXTENT_DEFRAG |
1374 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1375 PAGE_CLEAR_DIRTY |
1376 PAGE_SET_WRITEBACK |
1377 PAGE_END_WRITEBACK);
1378 btrfs_free_path(path);
1379 return ret;
1380 }
1381
1382 /*
1383 * extent_io.c call back to do delayed allocation processing
1384 */
1385 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1386 u64 start, u64 end, int *page_started,
1387 unsigned long *nr_written)
1388 {
1389 int ret;
1390 struct btrfs_root *root = BTRFS_I(inode)->root;
1391
1392 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) {
1393 ret = run_delalloc_nocow(inode, locked_page, start, end,
1394 page_started, 1, nr_written);
1395 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC) {
1396 ret = run_delalloc_nocow(inode, locked_page, start, end,
1397 page_started, 0, nr_written);
1398 } else if (!btrfs_test_opt(root, COMPRESS) &&
1399 !(BTRFS_I(inode)->force_compress) &&
1400 !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS)) {
1401 ret = cow_file_range(inode, locked_page, start, end,
1402 page_started, nr_written, 1);
1403 } else {
1404 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1405 &BTRFS_I(inode)->runtime_flags);
1406 ret = cow_file_range_async(inode, locked_page, start, end,
1407 page_started, nr_written);
1408 }
1409 return ret;
1410 }
1411
1412 static void btrfs_split_extent_hook(struct inode *inode,
1413 struct extent_state *orig, u64 split)
1414 {
1415 /* not delalloc, ignore it */
1416 if (!(orig->state & EXTENT_DELALLOC))
1417 return;
1418
1419 spin_lock(&BTRFS_I(inode)->lock);
1420 BTRFS_I(inode)->outstanding_extents++;
1421 spin_unlock(&BTRFS_I(inode)->lock);
1422 }
1423
1424 /*
1425 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1426 * extents so we can keep track of new extents that are just merged onto old
1427 * extents, such as when we are doing sequential writes, so we can properly
1428 * account for the metadata space we'll need.
1429 */
1430 static void btrfs_merge_extent_hook(struct inode *inode,
1431 struct extent_state *new,
1432 struct extent_state *other)
1433 {
1434 /* not delalloc, ignore it */
1435 if (!(other->state & EXTENT_DELALLOC))
1436 return;
1437
1438 spin_lock(&BTRFS_I(inode)->lock);
1439 BTRFS_I(inode)->outstanding_extents--;
1440 spin_unlock(&BTRFS_I(inode)->lock);
1441 }
1442
1443 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1444 struct inode *inode)
1445 {
1446 spin_lock(&root->delalloc_lock);
1447 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1448 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1449 &root->delalloc_inodes);
1450 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1451 &BTRFS_I(inode)->runtime_flags);
1452 root->nr_delalloc_inodes++;
1453 if (root->nr_delalloc_inodes == 1) {
1454 spin_lock(&root->fs_info->delalloc_root_lock);
1455 BUG_ON(!list_empty(&root->delalloc_root));
1456 list_add_tail(&root->delalloc_root,
1457 &root->fs_info->delalloc_roots);
1458 spin_unlock(&root->fs_info->delalloc_root_lock);
1459 }
1460 }
1461 spin_unlock(&root->delalloc_lock);
1462 }
1463
1464 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1465 struct inode *inode)
1466 {
1467 spin_lock(&root->delalloc_lock);
1468 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1469 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1470 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1471 &BTRFS_I(inode)->runtime_flags);
1472 root->nr_delalloc_inodes--;
1473 if (!root->nr_delalloc_inodes) {
1474 spin_lock(&root->fs_info->delalloc_root_lock);
1475 BUG_ON(list_empty(&root->delalloc_root));
1476 list_del_init(&root->delalloc_root);
1477 spin_unlock(&root->fs_info->delalloc_root_lock);
1478 }
1479 }
1480 spin_unlock(&root->delalloc_lock);
1481 }
1482
1483 /*
1484 * extent_io.c set_bit_hook, used to track delayed allocation
1485 * bytes in this file, and to maintain the list of inodes that
1486 * have pending delalloc work to be done.
1487 */
1488 static void btrfs_set_bit_hook(struct inode *inode,
1489 struct extent_state *state, unsigned long *bits)
1490 {
1491
1492 /*
1493 * set_bit and clear bit hooks normally require _irqsave/restore
1494 * but in this case, we are only testing for the DELALLOC
1495 * bit, which is only set or cleared with irqs on
1496 */
1497 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1498 struct btrfs_root *root = BTRFS_I(inode)->root;
1499 u64 len = state->end + 1 - state->start;
1500 bool do_list = !btrfs_is_free_space_inode(inode);
1501
1502 if (*bits & EXTENT_FIRST_DELALLOC) {
1503 *bits &= ~EXTENT_FIRST_DELALLOC;
1504 } else {
1505 spin_lock(&BTRFS_I(inode)->lock);
1506 BTRFS_I(inode)->outstanding_extents++;
1507 spin_unlock(&BTRFS_I(inode)->lock);
1508 }
1509
1510 __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
1511 root->fs_info->delalloc_batch);
1512 spin_lock(&BTRFS_I(inode)->lock);
1513 BTRFS_I(inode)->delalloc_bytes += len;
1514 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1515 &BTRFS_I(inode)->runtime_flags))
1516 btrfs_add_delalloc_inodes(root, inode);
1517 spin_unlock(&BTRFS_I(inode)->lock);
1518 }
1519 }
1520
1521 /*
1522 * extent_io.c clear_bit_hook, see set_bit_hook for why
1523 */
1524 static void btrfs_clear_bit_hook(struct inode *inode,
1525 struct extent_state *state,
1526 unsigned long *bits)
1527 {
1528 /*
1529 * set_bit and clear bit hooks normally require _irqsave/restore
1530 * but in this case, we are only testing for the DELALLOC
1531 * bit, which is only set or cleared with irqs on
1532 */
1533 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1534 struct btrfs_root *root = BTRFS_I(inode)->root;
1535 u64 len = state->end + 1 - state->start;
1536 bool do_list = !btrfs_is_free_space_inode(inode);
1537
1538 if (*bits & EXTENT_FIRST_DELALLOC) {
1539 *bits &= ~EXTENT_FIRST_DELALLOC;
1540 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1541 spin_lock(&BTRFS_I(inode)->lock);
1542 BTRFS_I(inode)->outstanding_extents--;
1543 spin_unlock(&BTRFS_I(inode)->lock);
1544 }
1545
1546 /*
1547 * We don't reserve metadata space for space cache inodes so we
1548 * don't need to call dellalloc_release_metadata if there is an
1549 * error.
1550 */
1551 if (*bits & EXTENT_DO_ACCOUNTING &&
1552 root != root->fs_info->tree_root)
1553 btrfs_delalloc_release_metadata(inode, len);
1554
1555 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1556 && do_list && !(state->state & EXTENT_NORESERVE))
1557 btrfs_free_reserved_data_space(inode, len);
1558
1559 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
1560 root->fs_info->delalloc_batch);
1561 spin_lock(&BTRFS_I(inode)->lock);
1562 BTRFS_I(inode)->delalloc_bytes -= len;
1563 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1564 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1565 &BTRFS_I(inode)->runtime_flags))
1566 btrfs_del_delalloc_inode(root, inode);
1567 spin_unlock(&BTRFS_I(inode)->lock);
1568 }
1569 }
1570
1571 /*
1572 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1573 * we don't create bios that span stripes or chunks
1574 */
1575 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
1576 size_t size, struct bio *bio,
1577 unsigned long bio_flags)
1578 {
1579 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1580 u64 logical = (u64)bio->bi_sector << 9;
1581 u64 length = 0;
1582 u64 map_length;
1583 int ret;
1584
1585 if (bio_flags & EXTENT_BIO_COMPRESSED)
1586 return 0;
1587
1588 length = bio->bi_size;
1589 map_length = length;
1590 ret = btrfs_map_block(root->fs_info, rw, logical,
1591 &map_length, NULL, 0);
1592 /* Will always return 0 with map_multi == NULL */
1593 BUG_ON(ret < 0);
1594 if (map_length < length + size)
1595 return 1;
1596 return 0;
1597 }
1598
1599 /*
1600 * in order to insert checksums into the metadata in large chunks,
1601 * we wait until bio submission time. All the pages in the bio are
1602 * checksummed and sums are attached onto the ordered extent record.
1603 *
1604 * At IO completion time the cums attached on the ordered extent record
1605 * are inserted into the btree
1606 */
1607 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1608 struct bio *bio, int mirror_num,
1609 unsigned long bio_flags,
1610 u64 bio_offset)
1611 {
1612 struct btrfs_root *root = BTRFS_I(inode)->root;
1613 int ret = 0;
1614
1615 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1616 BUG_ON(ret); /* -ENOMEM */
1617 return 0;
1618 }
1619
1620 /*
1621 * in order to insert checksums into the metadata in large chunks,
1622 * we wait until bio submission time. All the pages in the bio are
1623 * checksummed and sums are attached onto the ordered extent record.
1624 *
1625 * At IO completion time the cums attached on the ordered extent record
1626 * are inserted into the btree
1627 */
1628 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1629 int mirror_num, unsigned long bio_flags,
1630 u64 bio_offset)
1631 {
1632 struct btrfs_root *root = BTRFS_I(inode)->root;
1633 int ret;
1634
1635 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
1636 if (ret)
1637 bio_endio(bio, ret);
1638 return ret;
1639 }
1640
1641 /*
1642 * extent_io.c submission hook. This does the right thing for csum calculation
1643 * on write, or reading the csums from the tree before a read
1644 */
1645 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1646 int mirror_num, unsigned long bio_flags,
1647 u64 bio_offset)
1648 {
1649 struct btrfs_root *root = BTRFS_I(inode)->root;
1650 int ret = 0;
1651 int skip_sum;
1652 int metadata = 0;
1653 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1654
1655 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1656
1657 if (btrfs_is_free_space_inode(inode))
1658 metadata = 2;
1659
1660 if (!(rw & REQ_WRITE)) {
1661 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1662 if (ret)
1663 goto out;
1664
1665 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1666 ret = btrfs_submit_compressed_read(inode, bio,
1667 mirror_num,
1668 bio_flags);
1669 goto out;
1670 } else if (!skip_sum) {
1671 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1672 if (ret)
1673 goto out;
1674 }
1675 goto mapit;
1676 } else if (async && !skip_sum) {
1677 /* csum items have already been cloned */
1678 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1679 goto mapit;
1680 /* we're doing a write, do the async checksumming */
1681 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1682 inode, rw, bio, mirror_num,
1683 bio_flags, bio_offset,
1684 __btrfs_submit_bio_start,
1685 __btrfs_submit_bio_done);
1686 goto out;
1687 } else if (!skip_sum) {
1688 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1689 if (ret)
1690 goto out;
1691 }
1692
1693 mapit:
1694 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
1695
1696 out:
1697 if (ret < 0)
1698 bio_endio(bio, ret);
1699 return ret;
1700 }
1701
1702 /*
1703 * given a list of ordered sums record them in the inode. This happens
1704 * at IO completion time based on sums calculated at bio submission time.
1705 */
1706 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1707 struct inode *inode, u64 file_offset,
1708 struct list_head *list)
1709 {
1710 struct btrfs_ordered_sum *sum;
1711
1712 list_for_each_entry(sum, list, list) {
1713 trans->adding_csums = 1;
1714 btrfs_csum_file_blocks(trans,
1715 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1716 trans->adding_csums = 0;
1717 }
1718 return 0;
1719 }
1720
1721 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1722 struct extent_state **cached_state)
1723 {
1724 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0);
1725 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1726 cached_state, GFP_NOFS);
1727 }
1728
1729 /* see btrfs_writepage_start_hook for details on why this is required */
1730 struct btrfs_writepage_fixup {
1731 struct page *page;
1732 struct btrfs_work work;
1733 };
1734
1735 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1736 {
1737 struct btrfs_writepage_fixup *fixup;
1738 struct btrfs_ordered_extent *ordered;
1739 struct extent_state *cached_state = NULL;
1740 struct page *page;
1741 struct inode *inode;
1742 u64 page_start;
1743 u64 page_end;
1744 int ret;
1745
1746 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1747 page = fixup->page;
1748 again:
1749 lock_page(page);
1750 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1751 ClearPageChecked(page);
1752 goto out_page;
1753 }
1754
1755 inode = page->mapping->host;
1756 page_start = page_offset(page);
1757 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1758
1759 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
1760 &cached_state);
1761
1762 /* already ordered? We're done */
1763 if (PagePrivate2(page))
1764 goto out;
1765
1766 ordered = btrfs_lookup_ordered_extent(inode, page_start);
1767 if (ordered) {
1768 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
1769 page_end, &cached_state, GFP_NOFS);
1770 unlock_page(page);
1771 btrfs_start_ordered_extent(inode, ordered, 1);
1772 btrfs_put_ordered_extent(ordered);
1773 goto again;
1774 }
1775
1776 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
1777 if (ret) {
1778 mapping_set_error(page->mapping, ret);
1779 end_extent_writepage(page, ret, page_start, page_end);
1780 ClearPageChecked(page);
1781 goto out;
1782 }
1783
1784 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
1785 ClearPageChecked(page);
1786 set_page_dirty(page);
1787 out:
1788 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
1789 &cached_state, GFP_NOFS);
1790 out_page:
1791 unlock_page(page);
1792 page_cache_release(page);
1793 kfree(fixup);
1794 }
1795
1796 /*
1797 * There are a few paths in the higher layers of the kernel that directly
1798 * set the page dirty bit without asking the filesystem if it is a
1799 * good idea. This causes problems because we want to make sure COW
1800 * properly happens and the data=ordered rules are followed.
1801 *
1802 * In our case any range that doesn't have the ORDERED bit set
1803 * hasn't been properly setup for IO. We kick off an async process
1804 * to fix it up. The async helper will wait for ordered extents, set
1805 * the delalloc bit and make it safe to write the page.
1806 */
1807 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
1808 {
1809 struct inode *inode = page->mapping->host;
1810 struct btrfs_writepage_fixup *fixup;
1811 struct btrfs_root *root = BTRFS_I(inode)->root;
1812
1813 /* this page is properly in the ordered list */
1814 if (TestClearPagePrivate2(page))
1815 return 0;
1816
1817 if (PageChecked(page))
1818 return -EAGAIN;
1819
1820 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
1821 if (!fixup)
1822 return -EAGAIN;
1823
1824 SetPageChecked(page);
1825 page_cache_get(page);
1826 fixup->work.func = btrfs_writepage_fixup_worker;
1827 fixup->page = page;
1828 btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
1829 return -EBUSY;
1830 }
1831
1832 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
1833 struct inode *inode, u64 file_pos,
1834 u64 disk_bytenr, u64 disk_num_bytes,
1835 u64 num_bytes, u64 ram_bytes,
1836 u8 compression, u8 encryption,
1837 u16 other_encoding, int extent_type)
1838 {
1839 struct btrfs_root *root = BTRFS_I(inode)->root;
1840 struct btrfs_file_extent_item *fi;
1841 struct btrfs_path *path;
1842 struct extent_buffer *leaf;
1843 struct btrfs_key ins;
1844 int ret;
1845
1846 path = btrfs_alloc_path();
1847 if (!path)
1848 return -ENOMEM;
1849
1850 path->leave_spinning = 1;
1851
1852 /*
1853 * we may be replacing one extent in the tree with another.
1854 * The new extent is pinned in the extent map, and we don't want
1855 * to drop it from the cache until it is completely in the btree.
1856 *
1857 * So, tell btrfs_drop_extents to leave this extent in the cache.
1858 * the caller is expected to unpin it and allow it to be merged
1859 * with the others.
1860 */
1861 ret = btrfs_drop_extents(trans, root, inode, file_pos,
1862 file_pos + num_bytes, 0);
1863 if (ret)
1864 goto out;
1865
1866 ins.objectid = btrfs_ino(inode);
1867 ins.offset = file_pos;
1868 ins.type = BTRFS_EXTENT_DATA_KEY;
1869 ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi));
1870 if (ret)
1871 goto out;
1872 leaf = path->nodes[0];
1873 fi = btrfs_item_ptr(leaf, path->slots[0],
1874 struct btrfs_file_extent_item);
1875 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1876 btrfs_set_file_extent_type(leaf, fi, extent_type);
1877 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
1878 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
1879 btrfs_set_file_extent_offset(leaf, fi, 0);
1880 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
1881 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
1882 btrfs_set_file_extent_compression(leaf, fi, compression);
1883 btrfs_set_file_extent_encryption(leaf, fi, encryption);
1884 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
1885
1886 btrfs_mark_buffer_dirty(leaf);
1887 btrfs_release_path(path);
1888
1889 inode_add_bytes(inode, num_bytes);
1890
1891 ins.objectid = disk_bytenr;
1892 ins.offset = disk_num_bytes;
1893 ins.type = BTRFS_EXTENT_ITEM_KEY;
1894 ret = btrfs_alloc_reserved_file_extent(trans, root,
1895 root->root_key.objectid,
1896 btrfs_ino(inode), file_pos, &ins);
1897 out:
1898 btrfs_free_path(path);
1899
1900 return ret;
1901 }
1902
1903 /* snapshot-aware defrag */
1904 struct sa_defrag_extent_backref {
1905 struct rb_node node;
1906 struct old_sa_defrag_extent *old;
1907 u64 root_id;
1908 u64 inum;
1909 u64 file_pos;
1910 u64 extent_offset;
1911 u64 num_bytes;
1912 u64 generation;
1913 };
1914
1915 struct old_sa_defrag_extent {
1916 struct list_head list;
1917 struct new_sa_defrag_extent *new;
1918
1919 u64 extent_offset;
1920 u64 bytenr;
1921 u64 offset;
1922 u64 len;
1923 int count;
1924 };
1925
1926 struct new_sa_defrag_extent {
1927 struct rb_root root;
1928 struct list_head head;
1929 struct btrfs_path *path;
1930 struct inode *inode;
1931 u64 file_pos;
1932 u64 len;
1933 u64 bytenr;
1934 u64 disk_len;
1935 u8 compress_type;
1936 };
1937
1938 static int backref_comp(struct sa_defrag_extent_backref *b1,
1939 struct sa_defrag_extent_backref *b2)
1940 {
1941 if (b1->root_id < b2->root_id)
1942 return -1;
1943 else if (b1->root_id > b2->root_id)
1944 return 1;
1945
1946 if (b1->inum < b2->inum)
1947 return -1;
1948 else if (b1->inum > b2->inum)
1949 return 1;
1950
1951 if (b1->file_pos < b2->file_pos)
1952 return -1;
1953 else if (b1->file_pos > b2->file_pos)
1954 return 1;
1955
1956 /*
1957 * [------------------------------] ===> (a range of space)
1958 * |<--->| |<---->| =============> (fs/file tree A)
1959 * |<---------------------------->| ===> (fs/file tree B)
1960 *
1961 * A range of space can refer to two file extents in one tree while
1962 * refer to only one file extent in another tree.
1963 *
1964 * So we may process a disk offset more than one time(two extents in A)
1965 * and locate at the same extent(one extent in B), then insert two same
1966 * backrefs(both refer to the extent in B).
1967 */
1968 return 0;
1969 }
1970
1971 static void backref_insert(struct rb_root *root,
1972 struct sa_defrag_extent_backref *backref)
1973 {
1974 struct rb_node **p = &root->rb_node;
1975 struct rb_node *parent = NULL;
1976 struct sa_defrag_extent_backref *entry;
1977 int ret;
1978
1979 while (*p) {
1980 parent = *p;
1981 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
1982
1983 ret = backref_comp(backref, entry);
1984 if (ret < 0)
1985 p = &(*p)->rb_left;
1986 else
1987 p = &(*p)->rb_right;
1988 }
1989
1990 rb_link_node(&backref->node, parent, p);
1991 rb_insert_color(&backref->node, root);
1992 }
1993
1994 /*
1995 * Note the backref might has changed, and in this case we just return 0.
1996 */
1997 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
1998 void *ctx)
1999 {
2000 struct btrfs_file_extent_item *extent;
2001 struct btrfs_fs_info *fs_info;
2002 struct old_sa_defrag_extent *old = ctx;
2003 struct new_sa_defrag_extent *new = old->new;
2004 struct btrfs_path *path = new->path;
2005 struct btrfs_key key;
2006 struct btrfs_root *root;
2007 struct sa_defrag_extent_backref *backref;
2008 struct extent_buffer *leaf;
2009 struct inode *inode = new->inode;
2010 int slot;
2011 int ret;
2012 u64 extent_offset;
2013 u64 num_bytes;
2014
2015 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2016 inum == btrfs_ino(inode))
2017 return 0;
2018
2019 key.objectid = root_id;
2020 key.type = BTRFS_ROOT_ITEM_KEY;
2021 key.offset = (u64)-1;
2022
2023 fs_info = BTRFS_I(inode)->root->fs_info;
2024 root = btrfs_read_fs_root_no_name(fs_info, &key);
2025 if (IS_ERR(root)) {
2026 if (PTR_ERR(root) == -ENOENT)
2027 return 0;
2028 WARN_ON(1);
2029 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
2030 inum, offset, root_id);
2031 return PTR_ERR(root);
2032 }
2033
2034 key.objectid = inum;
2035 key.type = BTRFS_EXTENT_DATA_KEY;
2036 if (offset > (u64)-1 << 32)
2037 key.offset = 0;
2038 else
2039 key.offset = offset;
2040
2041 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2042 if (WARN_ON(ret < 0))
2043 return ret;
2044 ret = 0;
2045
2046 while (1) {
2047 cond_resched();
2048
2049 leaf = path->nodes[0];
2050 slot = path->slots[0];
2051
2052 if (slot >= btrfs_header_nritems(leaf)) {
2053 ret = btrfs_next_leaf(root, path);
2054 if (ret < 0) {
2055 goto out;
2056 } else if (ret > 0) {
2057 ret = 0;
2058 goto out;
2059 }
2060 continue;
2061 }
2062
2063 path->slots[0]++;
2064
2065 btrfs_item_key_to_cpu(leaf, &key, slot);
2066
2067 if (key.objectid > inum)
2068 goto out;
2069
2070 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2071 continue;
2072
2073 extent = btrfs_item_ptr(leaf, slot,
2074 struct btrfs_file_extent_item);
2075
2076 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2077 continue;
2078
2079 /*
2080 * 'offset' refers to the exact key.offset,
2081 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2082 * (key.offset - extent_offset).
2083 */
2084 if (key.offset != offset)
2085 continue;
2086
2087 extent_offset = btrfs_file_extent_offset(leaf, extent);
2088 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2089
2090 if (extent_offset >= old->extent_offset + old->offset +
2091 old->len || extent_offset + num_bytes <=
2092 old->extent_offset + old->offset)
2093 continue;
2094 break;
2095 }
2096
2097 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2098 if (!backref) {
2099 ret = -ENOENT;
2100 goto out;
2101 }
2102
2103 backref->root_id = root_id;
2104 backref->inum = inum;
2105 backref->file_pos = offset;
2106 backref->num_bytes = num_bytes;
2107 backref->extent_offset = extent_offset;
2108 backref->generation = btrfs_file_extent_generation(leaf, extent);
2109 backref->old = old;
2110 backref_insert(&new->root, backref);
2111 old->count++;
2112 out:
2113 btrfs_release_path(path);
2114 WARN_ON(ret);
2115 return ret;
2116 }
2117
2118 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2119 struct new_sa_defrag_extent *new)
2120 {
2121 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
2122 struct old_sa_defrag_extent *old, *tmp;
2123 int ret;
2124
2125 new->path = path;
2126
2127 list_for_each_entry_safe(old, tmp, &new->head, list) {
2128 ret = iterate_inodes_from_logical(old->bytenr +
2129 old->extent_offset, fs_info,
2130 path, record_one_backref,
2131 old);
2132 if (ret < 0 && ret != -ENOENT)
2133 return false;
2134
2135 /* no backref to be processed for this extent */
2136 if (!old->count) {
2137 list_del(&old->list);
2138 kfree(old);
2139 }
2140 }
2141
2142 if (list_empty(&new->head))
2143 return false;
2144
2145 return true;
2146 }
2147
2148 static int relink_is_mergable(struct extent_buffer *leaf,
2149 struct btrfs_file_extent_item *fi,
2150 struct new_sa_defrag_extent *new)
2151 {
2152 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2153 return 0;
2154
2155 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2156 return 0;
2157
2158 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2159 return 0;
2160
2161 if (btrfs_file_extent_encryption(leaf, fi) ||
2162 btrfs_file_extent_other_encoding(leaf, fi))
2163 return 0;
2164
2165 return 1;
2166 }
2167
2168 /*
2169 * Note the backref might has changed, and in this case we just return 0.
2170 */
2171 static noinline int relink_extent_backref(struct btrfs_path *path,
2172 struct sa_defrag_extent_backref *prev,
2173 struct sa_defrag_extent_backref *backref)
2174 {
2175 struct btrfs_file_extent_item *extent;
2176 struct btrfs_file_extent_item *item;
2177 struct btrfs_ordered_extent *ordered;
2178 struct btrfs_trans_handle *trans;
2179 struct btrfs_fs_info *fs_info;
2180 struct btrfs_root *root;
2181 struct btrfs_key key;
2182 struct extent_buffer *leaf;
2183 struct old_sa_defrag_extent *old = backref->old;
2184 struct new_sa_defrag_extent *new = old->new;
2185 struct inode *src_inode = new->inode;
2186 struct inode *inode;
2187 struct extent_state *cached = NULL;
2188 int ret = 0;
2189 u64 start;
2190 u64 len;
2191 u64 lock_start;
2192 u64 lock_end;
2193 bool merge = false;
2194 int index;
2195
2196 if (prev && prev->root_id == backref->root_id &&
2197 prev->inum == backref->inum &&
2198 prev->file_pos + prev->num_bytes == backref->file_pos)
2199 merge = true;
2200
2201 /* step 1: get root */
2202 key.objectid = backref->root_id;
2203 key.type = BTRFS_ROOT_ITEM_KEY;
2204 key.offset = (u64)-1;
2205
2206 fs_info = BTRFS_I(src_inode)->root->fs_info;
2207 index = srcu_read_lock(&fs_info->subvol_srcu);
2208
2209 root = btrfs_read_fs_root_no_name(fs_info, &key);
2210 if (IS_ERR(root)) {
2211 srcu_read_unlock(&fs_info->subvol_srcu, index);
2212 if (PTR_ERR(root) == -ENOENT)
2213 return 0;
2214 return PTR_ERR(root);
2215 }
2216
2217 /* step 2: get inode */
2218 key.objectid = backref->inum;
2219 key.type = BTRFS_INODE_ITEM_KEY;
2220 key.offset = 0;
2221
2222 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2223 if (IS_ERR(inode)) {
2224 srcu_read_unlock(&fs_info->subvol_srcu, index);
2225 return 0;
2226 }
2227
2228 srcu_read_unlock(&fs_info->subvol_srcu, index);
2229
2230 /* step 3: relink backref */
2231 lock_start = backref->file_pos;
2232 lock_end = backref->file_pos + backref->num_bytes - 1;
2233 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2234 0, &cached);
2235
2236 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2237 if (ordered) {
2238 btrfs_put_ordered_extent(ordered);
2239 goto out_unlock;
2240 }
2241
2242 trans = btrfs_join_transaction(root);
2243 if (IS_ERR(trans)) {
2244 ret = PTR_ERR(trans);
2245 goto out_unlock;
2246 }
2247
2248 key.objectid = backref->inum;
2249 key.type = BTRFS_EXTENT_DATA_KEY;
2250 key.offset = backref->file_pos;
2251
2252 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2253 if (ret < 0) {
2254 goto out_free_path;
2255 } else if (ret > 0) {
2256 ret = 0;
2257 goto out_free_path;
2258 }
2259
2260 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2261 struct btrfs_file_extent_item);
2262
2263 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2264 backref->generation)
2265 goto out_free_path;
2266
2267 btrfs_release_path(path);
2268
2269 start = backref->file_pos;
2270 if (backref->extent_offset < old->extent_offset + old->offset)
2271 start += old->extent_offset + old->offset -
2272 backref->extent_offset;
2273
2274 len = min(backref->extent_offset + backref->num_bytes,
2275 old->extent_offset + old->offset + old->len);
2276 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2277
2278 ret = btrfs_drop_extents(trans, root, inode, start,
2279 start + len, 1);
2280 if (ret)
2281 goto out_free_path;
2282 again:
2283 key.objectid = btrfs_ino(inode);
2284 key.type = BTRFS_EXTENT_DATA_KEY;
2285 key.offset = start;
2286
2287 path->leave_spinning = 1;
2288 if (merge) {
2289 struct btrfs_file_extent_item *fi;
2290 u64 extent_len;
2291 struct btrfs_key found_key;
2292
2293 ret = btrfs_search_slot(trans, root, &key, path, 1, 1);
2294 if (ret < 0)
2295 goto out_free_path;
2296
2297 path->slots[0]--;
2298 leaf = path->nodes[0];
2299 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2300
2301 fi = btrfs_item_ptr(leaf, path->slots[0],
2302 struct btrfs_file_extent_item);
2303 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2304
2305 if (extent_len + found_key.offset == start &&
2306 relink_is_mergable(leaf, fi, new)) {
2307 btrfs_set_file_extent_num_bytes(leaf, fi,
2308 extent_len + len);
2309 btrfs_mark_buffer_dirty(leaf);
2310 inode_add_bytes(inode, len);
2311
2312 ret = 1;
2313 goto out_free_path;
2314 } else {
2315 merge = false;
2316 btrfs_release_path(path);
2317 goto again;
2318 }
2319 }
2320
2321 ret = btrfs_insert_empty_item(trans, root, path, &key,
2322 sizeof(*extent));
2323 if (ret) {
2324 btrfs_abort_transaction(trans, root, ret);
2325 goto out_free_path;
2326 }
2327
2328 leaf = path->nodes[0];
2329 item = btrfs_item_ptr(leaf, path->slots[0],
2330 struct btrfs_file_extent_item);
2331 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2332 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2333 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2334 btrfs_set_file_extent_num_bytes(leaf, item, len);
2335 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2336 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2337 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2338 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2339 btrfs_set_file_extent_encryption(leaf, item, 0);
2340 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2341
2342 btrfs_mark_buffer_dirty(leaf);
2343 inode_add_bytes(inode, len);
2344 btrfs_release_path(path);
2345
2346 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2347 new->disk_len, 0,
2348 backref->root_id, backref->inum,
2349 new->file_pos, 0); /* start - extent_offset */
2350 if (ret) {
2351 btrfs_abort_transaction(trans, root, ret);
2352 goto out_free_path;
2353 }
2354
2355 ret = 1;
2356 out_free_path:
2357 btrfs_release_path(path);
2358 path->leave_spinning = 0;
2359 btrfs_end_transaction(trans, root);
2360 out_unlock:
2361 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2362 &cached, GFP_NOFS);
2363 iput(inode);
2364 return ret;
2365 }
2366
2367 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2368 {
2369 struct old_sa_defrag_extent *old, *tmp;
2370
2371 if (!new)
2372 return;
2373
2374 list_for_each_entry_safe(old, tmp, &new->head, list) {
2375 list_del(&old->list);
2376 kfree(old);
2377 }
2378 kfree(new);
2379 }
2380
2381 static void relink_file_extents(struct new_sa_defrag_extent *new)
2382 {
2383 struct btrfs_path *path;
2384 struct sa_defrag_extent_backref *backref;
2385 struct sa_defrag_extent_backref *prev = NULL;
2386 struct inode *inode;
2387 struct btrfs_root *root;
2388 struct rb_node *node;
2389 int ret;
2390
2391 inode = new->inode;
2392 root = BTRFS_I(inode)->root;
2393
2394 path = btrfs_alloc_path();
2395 if (!path)
2396 return;
2397
2398 if (!record_extent_backrefs(path, new)) {
2399 btrfs_free_path(path);
2400 goto out;
2401 }
2402 btrfs_release_path(path);
2403
2404 while (1) {
2405 node = rb_first(&new->root);
2406 if (!node)
2407 break;
2408 rb_erase(node, &new->root);
2409
2410 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2411
2412 ret = relink_extent_backref(path, prev, backref);
2413 WARN_ON(ret < 0);
2414
2415 kfree(prev);
2416
2417 if (ret == 1)
2418 prev = backref;
2419 else
2420 prev = NULL;
2421 cond_resched();
2422 }
2423 kfree(prev);
2424
2425 btrfs_free_path(path);
2426 out:
2427 free_sa_defrag_extent(new);
2428
2429 atomic_dec(&root->fs_info->defrag_running);
2430 wake_up(&root->fs_info->transaction_wait);
2431 }
2432
2433 static struct new_sa_defrag_extent *
2434 record_old_file_extents(struct inode *inode,
2435 struct btrfs_ordered_extent *ordered)
2436 {
2437 struct btrfs_root *root = BTRFS_I(inode)->root;
2438 struct btrfs_path *path;
2439 struct btrfs_key key;
2440 struct old_sa_defrag_extent *old;
2441 struct new_sa_defrag_extent *new;
2442 int ret;
2443
2444 new = kmalloc(sizeof(*new), GFP_NOFS);
2445 if (!new)
2446 return NULL;
2447
2448 new->inode = inode;
2449 new->file_pos = ordered->file_offset;
2450 new->len = ordered->len;
2451 new->bytenr = ordered->start;
2452 new->disk_len = ordered->disk_len;
2453 new->compress_type = ordered->compress_type;
2454 new->root = RB_ROOT;
2455 INIT_LIST_HEAD(&new->head);
2456
2457 path = btrfs_alloc_path();
2458 if (!path)
2459 goto out_kfree;
2460
2461 key.objectid = btrfs_ino(inode);
2462 key.type = BTRFS_EXTENT_DATA_KEY;
2463 key.offset = new->file_pos;
2464
2465 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2466 if (ret < 0)
2467 goto out_free_path;
2468 if (ret > 0 && path->slots[0] > 0)
2469 path->slots[0]--;
2470
2471 /* find out all the old extents for the file range */
2472 while (1) {
2473 struct btrfs_file_extent_item *extent;
2474 struct extent_buffer *l;
2475 int slot;
2476 u64 num_bytes;
2477 u64 offset;
2478 u64 end;
2479 u64 disk_bytenr;
2480 u64 extent_offset;
2481
2482 l = path->nodes[0];
2483 slot = path->slots[0];
2484
2485 if (slot >= btrfs_header_nritems(l)) {
2486 ret = btrfs_next_leaf(root, path);
2487 if (ret < 0)
2488 goto out_free_path;
2489 else if (ret > 0)
2490 break;
2491 continue;
2492 }
2493
2494 btrfs_item_key_to_cpu(l, &key, slot);
2495
2496 if (key.objectid != btrfs_ino(inode))
2497 break;
2498 if (key.type != BTRFS_EXTENT_DATA_KEY)
2499 break;
2500 if (key.offset >= new->file_pos + new->len)
2501 break;
2502
2503 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2504
2505 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2506 if (key.offset + num_bytes < new->file_pos)
2507 goto next;
2508
2509 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2510 if (!disk_bytenr)
2511 goto next;
2512
2513 extent_offset = btrfs_file_extent_offset(l, extent);
2514
2515 old = kmalloc(sizeof(*old), GFP_NOFS);
2516 if (!old)
2517 goto out_free_path;
2518
2519 offset = max(new->file_pos, key.offset);
2520 end = min(new->file_pos + new->len, key.offset + num_bytes);
2521
2522 old->bytenr = disk_bytenr;
2523 old->extent_offset = extent_offset;
2524 old->offset = offset - key.offset;
2525 old->len = end - offset;
2526 old->new = new;
2527 old->count = 0;
2528 list_add_tail(&old->list, &new->head);
2529 next:
2530 path->slots[0]++;
2531 cond_resched();
2532 }
2533
2534 btrfs_free_path(path);
2535 atomic_inc(&root->fs_info->defrag_running);
2536
2537 return new;
2538
2539 out_free_path:
2540 btrfs_free_path(path);
2541 out_kfree:
2542 free_sa_defrag_extent(new);
2543 return NULL;
2544 }
2545
2546 /*
2547 * helper function for btrfs_finish_ordered_io, this
2548 * just reads in some of the csum leaves to prime them into ram
2549 * before we start the transaction. It limits the amount of btree
2550 * reads required while inside the transaction.
2551 */
2552 /* as ordered data IO finishes, this gets called so we can finish
2553 * an ordered extent if the range of bytes in the file it covers are
2554 * fully written.
2555 */
2556 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2557 {
2558 struct inode *inode = ordered_extent->inode;
2559 struct btrfs_root *root = BTRFS_I(inode)->root;
2560 struct btrfs_trans_handle *trans = NULL;
2561 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2562 struct extent_state *cached_state = NULL;
2563 struct new_sa_defrag_extent *new = NULL;
2564 int compress_type = 0;
2565 int ret = 0;
2566 u64 logical_len = ordered_extent->len;
2567 bool nolock;
2568 bool truncated = false;
2569
2570 nolock = btrfs_is_free_space_inode(inode);
2571
2572 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2573 ret = -EIO;
2574 goto out;
2575 }
2576
2577 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2578 truncated = true;
2579 logical_len = ordered_extent->truncated_len;
2580 /* Truncated the entire extent, don't bother adding */
2581 if (!logical_len)
2582 goto out;
2583 }
2584
2585 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2586 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2587 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2588 if (nolock)
2589 trans = btrfs_join_transaction_nolock(root);
2590 else
2591 trans = btrfs_join_transaction(root);
2592 if (IS_ERR(trans)) {
2593 ret = PTR_ERR(trans);
2594 trans = NULL;
2595 goto out;
2596 }
2597 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2598 ret = btrfs_update_inode_fallback(trans, root, inode);
2599 if (ret) /* -ENOMEM or corruption */
2600 btrfs_abort_transaction(trans, root, ret);
2601 goto out;
2602 }
2603
2604 lock_extent_bits(io_tree, ordered_extent->file_offset,
2605 ordered_extent->file_offset + ordered_extent->len - 1,
2606 0, &cached_state);
2607
2608 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2609 ordered_extent->file_offset + ordered_extent->len - 1,
2610 EXTENT_DEFRAG, 1, cached_state);
2611 if (ret) {
2612 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2613 if (last_snapshot >= BTRFS_I(inode)->generation)
2614 /* the inode is shared */
2615 new = record_old_file_extents(inode, ordered_extent);
2616
2617 clear_extent_bit(io_tree, ordered_extent->file_offset,
2618 ordered_extent->file_offset + ordered_extent->len - 1,
2619 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2620 }
2621
2622 if (nolock)
2623 trans = btrfs_join_transaction_nolock(root);
2624 else
2625 trans = btrfs_join_transaction(root);
2626 if (IS_ERR(trans)) {
2627 ret = PTR_ERR(trans);
2628 trans = NULL;
2629 goto out_unlock;
2630 }
2631 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2632
2633 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2634 compress_type = ordered_extent->compress_type;
2635 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2636 BUG_ON(compress_type);
2637 ret = btrfs_mark_extent_written(trans, inode,
2638 ordered_extent->file_offset,
2639 ordered_extent->file_offset +
2640 logical_len);
2641 } else {
2642 BUG_ON(root == root->fs_info->tree_root);
2643 ret = insert_reserved_file_extent(trans, inode,
2644 ordered_extent->file_offset,
2645 ordered_extent->start,
2646 ordered_extent->disk_len,
2647 logical_len, logical_len,
2648 compress_type, 0, 0,
2649 BTRFS_FILE_EXTENT_REG);
2650 }
2651 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2652 ordered_extent->file_offset, ordered_extent->len,
2653 trans->transid);
2654 if (ret < 0) {
2655 btrfs_abort_transaction(trans, root, ret);
2656 goto out_unlock;
2657 }
2658
2659 add_pending_csums(trans, inode, ordered_extent->file_offset,
2660 &ordered_extent->list);
2661
2662 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2663 ret = btrfs_update_inode_fallback(trans, root, inode);
2664 if (ret) { /* -ENOMEM or corruption */
2665 btrfs_abort_transaction(trans, root, ret);
2666 goto out_unlock;
2667 }
2668 ret = 0;
2669 out_unlock:
2670 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2671 ordered_extent->file_offset +
2672 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2673 out:
2674 if (root != root->fs_info->tree_root)
2675 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2676 if (trans)
2677 btrfs_end_transaction(trans, root);
2678
2679 if (ret || truncated) {
2680 u64 start, end;
2681
2682 if (truncated)
2683 start = ordered_extent->file_offset + logical_len;
2684 else
2685 start = ordered_extent->file_offset;
2686 end = ordered_extent->file_offset + ordered_extent->len - 1;
2687 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
2688
2689 /* Drop the cache for the part of the extent we didn't write. */
2690 btrfs_drop_extent_cache(inode, start, end, 0);
2691
2692 /*
2693 * If the ordered extent had an IOERR or something else went
2694 * wrong we need to return the space for this ordered extent
2695 * back to the allocator. We only free the extent in the
2696 * truncated case if we didn't write out the extent at all.
2697 */
2698 if ((ret || !logical_len) &&
2699 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2700 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
2701 btrfs_free_reserved_extent(root, ordered_extent->start,
2702 ordered_extent->disk_len);
2703 }
2704
2705
2706 /*
2707 * This needs to be done to make sure anybody waiting knows we are done
2708 * updating everything for this ordered extent.
2709 */
2710 btrfs_remove_ordered_extent(inode, ordered_extent);
2711
2712 /* for snapshot-aware defrag */
2713 if (new) {
2714 if (ret) {
2715 free_sa_defrag_extent(new);
2716 atomic_dec(&root->fs_info->defrag_running);
2717 } else {
2718 relink_file_extents(new);
2719 }
2720 }
2721
2722 /* once for us */
2723 btrfs_put_ordered_extent(ordered_extent);
2724 /* once for the tree */
2725 btrfs_put_ordered_extent(ordered_extent);
2726
2727 return ret;
2728 }
2729
2730 static void finish_ordered_fn(struct btrfs_work *work)
2731 {
2732 struct btrfs_ordered_extent *ordered_extent;
2733 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
2734 btrfs_finish_ordered_io(ordered_extent);
2735 }
2736
2737 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
2738 struct extent_state *state, int uptodate)
2739 {
2740 struct inode *inode = page->mapping->host;
2741 struct btrfs_root *root = BTRFS_I(inode)->root;
2742 struct btrfs_ordered_extent *ordered_extent = NULL;
2743 struct btrfs_workers *workers;
2744
2745 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
2746
2747 ClearPagePrivate2(page);
2748 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
2749 end - start + 1, uptodate))
2750 return 0;
2751
2752 ordered_extent->work.func = finish_ordered_fn;
2753 ordered_extent->work.flags = 0;
2754
2755 if (btrfs_is_free_space_inode(inode))
2756 workers = &root->fs_info->endio_freespace_worker;
2757 else
2758 workers = &root->fs_info->endio_write_workers;
2759 btrfs_queue_worker(workers, &ordered_extent->work);
2760
2761 return 0;
2762 }
2763
2764 /*
2765 * when reads are done, we need to check csums to verify the data is correct
2766 * if there's a match, we allow the bio to finish. If not, the code in
2767 * extent_io.c will try to find good copies for us.
2768 */
2769 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
2770 u64 phy_offset, struct page *page,
2771 u64 start, u64 end, int mirror)
2772 {
2773 size_t offset = start - page_offset(page);
2774 struct inode *inode = page->mapping->host;
2775 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2776 char *kaddr;
2777 struct btrfs_root *root = BTRFS_I(inode)->root;
2778 u32 csum_expected;
2779 u32 csum = ~(u32)0;
2780 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
2781 DEFAULT_RATELIMIT_BURST);
2782
2783 if (PageChecked(page)) {
2784 ClearPageChecked(page);
2785 goto good;
2786 }
2787
2788 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
2789 goto good;
2790
2791 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
2792 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
2793 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
2794 GFP_NOFS);
2795 return 0;
2796 }
2797
2798 phy_offset >>= inode->i_sb->s_blocksize_bits;
2799 csum_expected = *(((u32 *)io_bio->csum) + phy_offset);
2800
2801 kaddr = kmap_atomic(page);
2802 csum = btrfs_csum_data(kaddr + offset, csum, end - start + 1);
2803 btrfs_csum_final(csum, (char *)&csum);
2804 if (csum != csum_expected)
2805 goto zeroit;
2806
2807 kunmap_atomic(kaddr);
2808 good:
2809 return 0;
2810
2811 zeroit:
2812 if (__ratelimit(&_rs))
2813 btrfs_info(root->fs_info, "csum failed ino %llu off %llu csum %u expected csum %u",
2814 btrfs_ino(page->mapping->host), start, csum, csum_expected);
2815 memset(kaddr + offset, 1, end - start + 1);
2816 flush_dcache_page(page);
2817 kunmap_atomic(kaddr);
2818 if (csum_expected == 0)
2819 return 0;
2820 return -EIO;
2821 }
2822
2823 struct delayed_iput {
2824 struct list_head list;
2825 struct inode *inode;
2826 };
2827
2828 /* JDM: If this is fs-wide, why can't we add a pointer to
2829 * btrfs_inode instead and avoid the allocation? */
2830 void btrfs_add_delayed_iput(struct inode *inode)
2831 {
2832 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2833 struct delayed_iput *delayed;
2834
2835 if (atomic_add_unless(&inode->i_count, -1, 1))
2836 return;
2837
2838 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
2839 delayed->inode = inode;
2840
2841 spin_lock(&fs_info->delayed_iput_lock);
2842 list_add_tail(&delayed->list, &fs_info->delayed_iputs);
2843 spin_unlock(&fs_info->delayed_iput_lock);
2844 }
2845
2846 void btrfs_run_delayed_iputs(struct btrfs_root *root)
2847 {
2848 LIST_HEAD(list);
2849 struct btrfs_fs_info *fs_info = root->fs_info;
2850 struct delayed_iput *delayed;
2851 int empty;
2852
2853 spin_lock(&fs_info->delayed_iput_lock);
2854 empty = list_empty(&fs_info->delayed_iputs);
2855 spin_unlock(&fs_info->delayed_iput_lock);
2856 if (empty)
2857 return;
2858
2859 spin_lock(&fs_info->delayed_iput_lock);
2860 list_splice_init(&fs_info->delayed_iputs, &list);
2861 spin_unlock(&fs_info->delayed_iput_lock);
2862
2863 while (!list_empty(&list)) {
2864 delayed = list_entry(list.next, struct delayed_iput, list);
2865 list_del(&delayed->list);
2866 iput(delayed->inode);
2867 kfree(delayed);
2868 }
2869 }
2870
2871 /*
2872 * This is called in transaction commit time. If there are no orphan
2873 * files in the subvolume, it removes orphan item and frees block_rsv
2874 * structure.
2875 */
2876 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
2877 struct btrfs_root *root)
2878 {
2879 struct btrfs_block_rsv *block_rsv;
2880 int ret;
2881
2882 if (atomic_read(&root->orphan_inodes) ||
2883 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
2884 return;
2885
2886 spin_lock(&root->orphan_lock);
2887 if (atomic_read(&root->orphan_inodes)) {
2888 spin_unlock(&root->orphan_lock);
2889 return;
2890 }
2891
2892 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
2893 spin_unlock(&root->orphan_lock);
2894 return;
2895 }
2896
2897 block_rsv = root->orphan_block_rsv;
2898 root->orphan_block_rsv = NULL;
2899 spin_unlock(&root->orphan_lock);
2900
2901 if (root->orphan_item_inserted &&
2902 btrfs_root_refs(&root->root_item) > 0) {
2903 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
2904 root->root_key.objectid);
2905 if (ret)
2906 btrfs_abort_transaction(trans, root, ret);
2907 else
2908 root->orphan_item_inserted = 0;
2909 }
2910
2911 if (block_rsv) {
2912 WARN_ON(block_rsv->size > 0);
2913 btrfs_free_block_rsv(root, block_rsv);
2914 }
2915 }
2916
2917 /*
2918 * This creates an orphan entry for the given inode in case something goes
2919 * wrong in the middle of an unlink/truncate.
2920 *
2921 * NOTE: caller of this function should reserve 5 units of metadata for
2922 * this function.
2923 */
2924 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
2925 {
2926 struct btrfs_root *root = BTRFS_I(inode)->root;
2927 struct btrfs_block_rsv *block_rsv = NULL;
2928 int reserve = 0;
2929 int insert = 0;
2930 int ret;
2931
2932 if (!root->orphan_block_rsv) {
2933 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
2934 if (!block_rsv)
2935 return -ENOMEM;
2936 }
2937
2938 spin_lock(&root->orphan_lock);
2939 if (!root->orphan_block_rsv) {
2940 root->orphan_block_rsv = block_rsv;
2941 } else if (block_rsv) {
2942 btrfs_free_block_rsv(root, block_rsv);
2943 block_rsv = NULL;
2944 }
2945
2946 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
2947 &BTRFS_I(inode)->runtime_flags)) {
2948 #if 0
2949 /*
2950 * For proper ENOSPC handling, we should do orphan
2951 * cleanup when mounting. But this introduces backward
2952 * compatibility issue.
2953 */
2954 if (!xchg(&root->orphan_item_inserted, 1))
2955 insert = 2;
2956 else
2957 insert = 1;
2958 #endif
2959 insert = 1;
2960 atomic_inc(&root->orphan_inodes);
2961 }
2962
2963 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
2964 &BTRFS_I(inode)->runtime_flags))
2965 reserve = 1;
2966 spin_unlock(&root->orphan_lock);
2967
2968 /* grab metadata reservation from transaction handle */
2969 if (reserve) {
2970 ret = btrfs_orphan_reserve_metadata(trans, inode);
2971 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
2972 }
2973
2974 /* insert an orphan item to track this unlinked/truncated file */
2975 if (insert >= 1) {
2976 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
2977 if (ret) {
2978 atomic_dec(&root->orphan_inodes);
2979 if (reserve) {
2980 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
2981 &BTRFS_I(inode)->runtime_flags);
2982 btrfs_orphan_release_metadata(inode);
2983 }
2984 if (ret != -EEXIST) {
2985 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
2986 &BTRFS_I(inode)->runtime_flags);
2987 btrfs_abort_transaction(trans, root, ret);
2988 return ret;
2989 }
2990 }
2991 ret = 0;
2992 }
2993
2994 /* insert an orphan item to track subvolume contains orphan files */
2995 if (insert >= 2) {
2996 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
2997 root->root_key.objectid);
2998 if (ret && ret != -EEXIST) {
2999 btrfs_abort_transaction(trans, root, ret);
3000 return ret;
3001 }
3002 }
3003 return 0;
3004 }
3005
3006 /*
3007 * We have done the truncate/delete so we can go ahead and remove the orphan
3008 * item for this particular inode.
3009 */
3010 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3011 struct inode *inode)
3012 {
3013 struct btrfs_root *root = BTRFS_I(inode)->root;
3014 int delete_item = 0;
3015 int release_rsv = 0;
3016 int ret = 0;
3017
3018 spin_lock(&root->orphan_lock);
3019 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3020 &BTRFS_I(inode)->runtime_flags))
3021 delete_item = 1;
3022
3023 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3024 &BTRFS_I(inode)->runtime_flags))
3025 release_rsv = 1;
3026 spin_unlock(&root->orphan_lock);
3027
3028 if (delete_item) {
3029 atomic_dec(&root->orphan_inodes);
3030 if (trans)
3031 ret = btrfs_del_orphan_item(trans, root,
3032 btrfs_ino(inode));
3033 }
3034
3035 if (release_rsv)
3036 btrfs_orphan_release_metadata(inode);
3037
3038 return ret;
3039 }
3040
3041 /*
3042 * this cleans up any orphans that may be left on the list from the last use
3043 * of this root.
3044 */
3045 int btrfs_orphan_cleanup(struct btrfs_root *root)
3046 {
3047 struct btrfs_path *path;
3048 struct extent_buffer *leaf;
3049 struct btrfs_key key, found_key;
3050 struct btrfs_trans_handle *trans;
3051 struct inode *inode;
3052 u64 last_objectid = 0;
3053 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3054
3055 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3056 return 0;
3057
3058 path = btrfs_alloc_path();
3059 if (!path) {
3060 ret = -ENOMEM;
3061 goto out;
3062 }
3063 path->reada = -1;
3064
3065 key.objectid = BTRFS_ORPHAN_OBJECTID;
3066 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
3067 key.offset = (u64)-1;
3068
3069 while (1) {
3070 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3071 if (ret < 0)
3072 goto out;
3073
3074 /*
3075 * if ret == 0 means we found what we were searching for, which
3076 * is weird, but possible, so only screw with path if we didn't
3077 * find the key and see if we have stuff that matches
3078 */
3079 if (ret > 0) {
3080 ret = 0;
3081 if (path->slots[0] == 0)
3082 break;
3083 path->slots[0]--;
3084 }
3085
3086 /* pull out the item */
3087 leaf = path->nodes[0];
3088 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3089
3090 /* make sure the item matches what we want */
3091 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3092 break;
3093 if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
3094 break;
3095
3096 /* release the path since we're done with it */
3097 btrfs_release_path(path);
3098
3099 /*
3100 * this is where we are basically btrfs_lookup, without the
3101 * crossing root thing. we store the inode number in the
3102 * offset of the orphan item.
3103 */
3104
3105 if (found_key.offset == last_objectid) {
3106 btrfs_err(root->fs_info,
3107 "Error removing orphan entry, stopping orphan cleanup");
3108 ret = -EINVAL;
3109 goto out;
3110 }
3111
3112 last_objectid = found_key.offset;
3113
3114 found_key.objectid = found_key.offset;
3115 found_key.type = BTRFS_INODE_ITEM_KEY;
3116 found_key.offset = 0;
3117 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3118 ret = PTR_ERR_OR_ZERO(inode);
3119 if (ret && ret != -ESTALE)
3120 goto out;
3121
3122 if (ret == -ESTALE && root == root->fs_info->tree_root) {
3123 struct btrfs_root *dead_root;
3124 struct btrfs_fs_info *fs_info = root->fs_info;
3125 int is_dead_root = 0;
3126
3127 /*
3128 * this is an orphan in the tree root. Currently these
3129 * could come from 2 sources:
3130 * a) a snapshot deletion in progress
3131 * b) a free space cache inode
3132 * We need to distinguish those two, as the snapshot
3133 * orphan must not get deleted.
3134 * find_dead_roots already ran before us, so if this
3135 * is a snapshot deletion, we should find the root
3136 * in the dead_roots list
3137 */
3138 spin_lock(&fs_info->trans_lock);
3139 list_for_each_entry(dead_root, &fs_info->dead_roots,
3140 root_list) {
3141 if (dead_root->root_key.objectid ==
3142 found_key.objectid) {
3143 is_dead_root = 1;
3144 break;
3145 }
3146 }
3147 spin_unlock(&fs_info->trans_lock);
3148 if (is_dead_root) {
3149 /* prevent this orphan from being found again */
3150 key.offset = found_key.objectid - 1;
3151 continue;
3152 }
3153 }
3154 /*
3155 * Inode is already gone but the orphan item is still there,
3156 * kill the orphan item.
3157 */
3158 if (ret == -ESTALE) {
3159 trans = btrfs_start_transaction(root, 1);
3160 if (IS_ERR(trans)) {
3161 ret = PTR_ERR(trans);
3162 goto out;
3163 }
3164 btrfs_debug(root->fs_info, "auto deleting %Lu",
3165 found_key.objectid);
3166 ret = btrfs_del_orphan_item(trans, root,
3167 found_key.objectid);
3168 btrfs_end_transaction(trans, root);
3169 if (ret)
3170 goto out;
3171 continue;
3172 }
3173
3174 /*
3175 * add this inode to the orphan list so btrfs_orphan_del does
3176 * the proper thing when we hit it
3177 */
3178 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3179 &BTRFS_I(inode)->runtime_flags);
3180 atomic_inc(&root->orphan_inodes);
3181
3182 /* if we have links, this was a truncate, lets do that */
3183 if (inode->i_nlink) {
3184 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3185 iput(inode);
3186 continue;
3187 }
3188 nr_truncate++;
3189
3190 /* 1 for the orphan item deletion. */
3191 trans = btrfs_start_transaction(root, 1);
3192 if (IS_ERR(trans)) {
3193 iput(inode);
3194 ret = PTR_ERR(trans);
3195 goto out;
3196 }
3197 ret = btrfs_orphan_add(trans, inode);
3198 btrfs_end_transaction(trans, root);
3199 if (ret) {
3200 iput(inode);
3201 goto out;
3202 }
3203
3204 ret = btrfs_truncate(inode);
3205 if (ret)
3206 btrfs_orphan_del(NULL, inode);
3207 } else {
3208 nr_unlink++;
3209 }
3210
3211 /* this will do delete_inode and everything for us */
3212 iput(inode);
3213 if (ret)
3214 goto out;
3215 }
3216 /* release the path since we're done with it */
3217 btrfs_release_path(path);
3218
3219 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3220
3221 if (root->orphan_block_rsv)
3222 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3223 (u64)-1);
3224
3225 if (root->orphan_block_rsv || root->orphan_item_inserted) {
3226 trans = btrfs_join_transaction(root);
3227 if (!IS_ERR(trans))
3228 btrfs_end_transaction(trans, root);
3229 }
3230
3231 if (nr_unlink)
3232 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3233 if (nr_truncate)
3234 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3235
3236 out:
3237 if (ret)
3238 btrfs_crit(root->fs_info,
3239 "could not do orphan cleanup %d", ret);
3240 btrfs_free_path(path);
3241 return ret;
3242 }
3243
3244 /*
3245 * very simple check to peek ahead in the leaf looking for xattrs. If we
3246 * don't find any xattrs, we know there can't be any acls.
3247 *
3248 * slot is the slot the inode is in, objectid is the objectid of the inode
3249 */
3250 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3251 int slot, u64 objectid)
3252 {
3253 u32 nritems = btrfs_header_nritems(leaf);
3254 struct btrfs_key found_key;
3255 static u64 xattr_access = 0;
3256 static u64 xattr_default = 0;
3257 int scanned = 0;
3258
3259 if (!xattr_access) {
3260 xattr_access = btrfs_name_hash(POSIX_ACL_XATTR_ACCESS,
3261 strlen(POSIX_ACL_XATTR_ACCESS));
3262 xattr_default = btrfs_name_hash(POSIX_ACL_XATTR_DEFAULT,
3263 strlen(POSIX_ACL_XATTR_DEFAULT));
3264 }
3265
3266 slot++;
3267 while (slot < nritems) {
3268 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3269
3270 /* we found a different objectid, there must not be acls */
3271 if (found_key.objectid != objectid)
3272 return 0;
3273
3274 /* we found an xattr, assume we've got an acl */
3275 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3276 if (found_key.offset == xattr_access ||
3277 found_key.offset == xattr_default)
3278 return 1;
3279 }
3280
3281 /*
3282 * we found a key greater than an xattr key, there can't
3283 * be any acls later on
3284 */
3285 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3286 return 0;
3287
3288 slot++;
3289 scanned++;
3290
3291 /*
3292 * it goes inode, inode backrefs, xattrs, extents,
3293 * so if there are a ton of hard links to an inode there can
3294 * be a lot of backrefs. Don't waste time searching too hard,
3295 * this is just an optimization
3296 */
3297 if (scanned >= 8)
3298 break;
3299 }
3300 /* we hit the end of the leaf before we found an xattr or
3301 * something larger than an xattr. We have to assume the inode
3302 * has acls
3303 */
3304 return 1;
3305 }
3306
3307 /*
3308 * read an inode from the btree into the in-memory inode
3309 */
3310 static void btrfs_read_locked_inode(struct inode *inode)
3311 {
3312 struct btrfs_path *path;
3313 struct extent_buffer *leaf;
3314 struct btrfs_inode_item *inode_item;
3315 struct btrfs_timespec *tspec;
3316 struct btrfs_root *root = BTRFS_I(inode)->root;
3317 struct btrfs_key location;
3318 int maybe_acls;
3319 u32 rdev;
3320 int ret;
3321 bool filled = false;
3322
3323 ret = btrfs_fill_inode(inode, &rdev);
3324 if (!ret)
3325 filled = true;
3326
3327 path = btrfs_alloc_path();
3328 if (!path)
3329 goto make_bad;
3330
3331 path->leave_spinning = 1;
3332 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3333
3334 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3335 if (ret)
3336 goto make_bad;
3337
3338 leaf = path->nodes[0];
3339
3340 if (filled)
3341 goto cache_acl;
3342
3343 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3344 struct btrfs_inode_item);
3345 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3346 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3347 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3348 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3349 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3350
3351 tspec = btrfs_inode_atime(inode_item);
3352 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3353 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3354
3355 tspec = btrfs_inode_mtime(inode_item);
3356 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3357 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3358
3359 tspec = btrfs_inode_ctime(inode_item);
3360 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3361 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3362
3363 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3364 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3365 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3366
3367 /*
3368 * If we were modified in the current generation and evicted from memory
3369 * and then re-read we need to do a full sync since we don't have any
3370 * idea about which extents were modified before we were evicted from
3371 * cache.
3372 */
3373 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3374 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3375 &BTRFS_I(inode)->runtime_flags);
3376
3377 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3378 inode->i_generation = BTRFS_I(inode)->generation;
3379 inode->i_rdev = 0;
3380 rdev = btrfs_inode_rdev(leaf, inode_item);
3381
3382 BTRFS_I(inode)->index_cnt = (u64)-1;
3383 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3384 cache_acl:
3385 /*
3386 * try to precache a NULL acl entry for files that don't have
3387 * any xattrs or acls
3388 */
3389 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3390 btrfs_ino(inode));
3391 if (!maybe_acls)
3392 cache_no_acl(inode);
3393
3394 btrfs_free_path(path);
3395
3396 switch (inode->i_mode & S_IFMT) {
3397 case S_IFREG:
3398 inode->i_mapping->a_ops = &btrfs_aops;
3399 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3400 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3401 inode->i_fop = &btrfs_file_operations;
3402 inode->i_op = &btrfs_file_inode_operations;
3403 break;
3404 case S_IFDIR:
3405 inode->i_fop = &btrfs_dir_file_operations;
3406 if (root == root->fs_info->tree_root)
3407 inode->i_op = &btrfs_dir_ro_inode_operations;
3408 else
3409 inode->i_op = &btrfs_dir_inode_operations;
3410 break;
3411 case S_IFLNK:
3412 inode->i_op = &btrfs_symlink_inode_operations;
3413 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3414 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3415 break;
3416 default:
3417 inode->i_op = &btrfs_special_inode_operations;
3418 init_special_inode(inode, inode->i_mode, rdev);
3419 break;
3420 }
3421
3422 btrfs_update_iflags(inode);
3423 return;
3424
3425 make_bad:
3426 btrfs_free_path(path);
3427 make_bad_inode(inode);
3428 }
3429
3430 /*
3431 * given a leaf and an inode, copy the inode fields into the leaf
3432 */
3433 static void fill_inode_item(struct btrfs_trans_handle *trans,
3434 struct extent_buffer *leaf,
3435 struct btrfs_inode_item *item,
3436 struct inode *inode)
3437 {
3438 struct btrfs_map_token token;
3439
3440 btrfs_init_map_token(&token);
3441
3442 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3443 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3444 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3445 &token);
3446 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3447 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3448
3449 btrfs_set_token_timespec_sec(leaf, btrfs_inode_atime(item),
3450 inode->i_atime.tv_sec, &token);
3451 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_atime(item),
3452 inode->i_atime.tv_nsec, &token);
3453
3454 btrfs_set_token_timespec_sec(leaf, btrfs_inode_mtime(item),
3455 inode->i_mtime.tv_sec, &token);
3456 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_mtime(item),
3457 inode->i_mtime.tv_nsec, &token);
3458
3459 btrfs_set_token_timespec_sec(leaf, btrfs_inode_ctime(item),
3460 inode->i_ctime.tv_sec, &token);
3461 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_ctime(item),
3462 inode->i_ctime.tv_nsec, &token);
3463
3464 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3465 &token);
3466 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3467 &token);
3468 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3469 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3470 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3471 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3472 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3473 }
3474
3475 /*
3476 * copy everything in the in-memory inode into the btree.
3477 */
3478 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3479 struct btrfs_root *root, struct inode *inode)
3480 {
3481 struct btrfs_inode_item *inode_item;
3482 struct btrfs_path *path;
3483 struct extent_buffer *leaf;
3484 int ret;
3485
3486 path = btrfs_alloc_path();
3487 if (!path)
3488 return -ENOMEM;
3489
3490 path->leave_spinning = 1;
3491 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3492 1);
3493 if (ret) {
3494 if (ret > 0)
3495 ret = -ENOENT;
3496 goto failed;
3497 }
3498
3499 btrfs_unlock_up_safe(path, 1);
3500 leaf = path->nodes[0];
3501 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3502 struct btrfs_inode_item);
3503
3504 fill_inode_item(trans, leaf, inode_item, inode);
3505 btrfs_mark_buffer_dirty(leaf);
3506 btrfs_set_inode_last_trans(trans, inode);
3507 ret = 0;
3508 failed:
3509 btrfs_free_path(path);
3510 return ret;
3511 }
3512
3513 /*
3514 * copy everything in the in-memory inode into the btree.
3515 */
3516 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3517 struct btrfs_root *root, struct inode *inode)
3518 {
3519 int ret;
3520
3521 /*
3522 * If the inode is a free space inode, we can deadlock during commit
3523 * if we put it into the delayed code.
3524 *
3525 * The data relocation inode should also be directly updated
3526 * without delay
3527 */
3528 if (!btrfs_is_free_space_inode(inode)
3529 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) {
3530 btrfs_update_root_times(trans, root);
3531
3532 ret = btrfs_delayed_update_inode(trans, root, inode);
3533 if (!ret)
3534 btrfs_set_inode_last_trans(trans, inode);
3535 return ret;
3536 }
3537
3538 return btrfs_update_inode_item(trans, root, inode);
3539 }
3540
3541 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3542 struct btrfs_root *root,
3543 struct inode *inode)
3544 {
3545 int ret;
3546
3547 ret = btrfs_update_inode(trans, root, inode);
3548 if (ret == -ENOSPC)
3549 return btrfs_update_inode_item(trans, root, inode);
3550 return ret;
3551 }
3552
3553 /*
3554 * unlink helper that gets used here in inode.c and in the tree logging
3555 * recovery code. It remove a link in a directory with a given name, and
3556 * also drops the back refs in the inode to the directory
3557 */
3558 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3559 struct btrfs_root *root,
3560 struct inode *dir, struct inode *inode,
3561 const char *name, int name_len)
3562 {
3563 struct btrfs_path *path;
3564 int ret = 0;
3565 struct extent_buffer *leaf;
3566 struct btrfs_dir_item *di;
3567 struct btrfs_key key;
3568 u64 index;
3569 u64 ino = btrfs_ino(inode);
3570 u64 dir_ino = btrfs_ino(dir);
3571
3572 path = btrfs_alloc_path();
3573 if (!path) {
3574 ret = -ENOMEM;
3575 goto out;
3576 }
3577
3578 path->leave_spinning = 1;
3579 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3580 name, name_len, -1);
3581 if (IS_ERR(di)) {
3582 ret = PTR_ERR(di);
3583 goto err;
3584 }
3585 if (!di) {
3586 ret = -ENOENT;
3587 goto err;
3588 }
3589 leaf = path->nodes[0];
3590 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3591 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3592 if (ret)
3593 goto err;
3594 btrfs_release_path(path);
3595
3596 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
3597 dir_ino, &index);
3598 if (ret) {
3599 btrfs_info(root->fs_info,
3600 "failed to delete reference to %.*s, inode %llu parent %llu",
3601 name_len, name, ino, dir_ino);
3602 btrfs_abort_transaction(trans, root, ret);
3603 goto err;
3604 }
3605
3606 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3607 if (ret) {
3608 btrfs_abort_transaction(trans, root, ret);
3609 goto err;
3610 }
3611
3612 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
3613 inode, dir_ino);
3614 if (ret != 0 && ret != -ENOENT) {
3615 btrfs_abort_transaction(trans, root, ret);
3616 goto err;
3617 }
3618
3619 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
3620 dir, index);
3621 if (ret == -ENOENT)
3622 ret = 0;
3623 else if (ret)
3624 btrfs_abort_transaction(trans, root, ret);
3625 err:
3626 btrfs_free_path(path);
3627 if (ret)
3628 goto out;
3629
3630 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3631 inode_inc_iversion(inode);
3632 inode_inc_iversion(dir);
3633 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3634 ret = btrfs_update_inode(trans, root, dir);
3635 out:
3636 return ret;
3637 }
3638
3639 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3640 struct btrfs_root *root,
3641 struct inode *dir, struct inode *inode,
3642 const char *name, int name_len)
3643 {
3644 int ret;
3645 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
3646 if (!ret) {
3647 drop_nlink(inode);
3648 ret = btrfs_update_inode(trans, root, inode);
3649 }
3650 return ret;
3651 }
3652
3653 /*
3654 * helper to start transaction for unlink and rmdir.
3655 *
3656 * unlink and rmdir are special in btrfs, they do not always free space, so
3657 * if we cannot make our reservations the normal way try and see if there is
3658 * plenty of slack room in the global reserve to migrate, otherwise we cannot
3659 * allow the unlink to occur.
3660 */
3661 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
3662 {
3663 struct btrfs_trans_handle *trans;
3664 struct btrfs_root *root = BTRFS_I(dir)->root;
3665 int ret;
3666
3667 /*
3668 * 1 for the possible orphan item
3669 * 1 for the dir item
3670 * 1 for the dir index
3671 * 1 for the inode ref
3672 * 1 for the inode
3673 */
3674 trans = btrfs_start_transaction(root, 5);
3675 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
3676 return trans;
3677
3678 if (PTR_ERR(trans) == -ENOSPC) {
3679 u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5);
3680
3681 trans = btrfs_start_transaction(root, 0);
3682 if (IS_ERR(trans))
3683 return trans;
3684 ret = btrfs_cond_migrate_bytes(root->fs_info,
3685 &root->fs_info->trans_block_rsv,
3686 num_bytes, 5);
3687 if (ret) {
3688 btrfs_end_transaction(trans, root);
3689 return ERR_PTR(ret);
3690 }
3691 trans->block_rsv = &root->fs_info->trans_block_rsv;
3692 trans->bytes_reserved = num_bytes;
3693 }
3694 return trans;
3695 }
3696
3697 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
3698 {
3699 struct btrfs_root *root = BTRFS_I(dir)->root;
3700 struct btrfs_trans_handle *trans;
3701 struct inode *inode = dentry->d_inode;
3702 int ret;
3703
3704 trans = __unlink_start_trans(dir);
3705 if (IS_ERR(trans))
3706 return PTR_ERR(trans);
3707
3708 btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0);
3709
3710 ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3711 dentry->d_name.name, dentry->d_name.len);
3712 if (ret)
3713 goto out;
3714
3715 if (inode->i_nlink == 0) {
3716 ret = btrfs_orphan_add(trans, inode);
3717 if (ret)
3718 goto out;
3719 }
3720
3721 out:
3722 btrfs_end_transaction(trans, root);
3723 btrfs_btree_balance_dirty(root);
3724 return ret;
3725 }
3726
3727 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
3728 struct btrfs_root *root,
3729 struct inode *dir, u64 objectid,
3730 const char *name, int name_len)
3731 {
3732 struct btrfs_path *path;
3733 struct extent_buffer *leaf;
3734 struct btrfs_dir_item *di;
3735 struct btrfs_key key;
3736 u64 index;
3737 int ret;
3738 u64 dir_ino = btrfs_ino(dir);
3739
3740 path = btrfs_alloc_path();
3741 if (!path)
3742 return -ENOMEM;
3743
3744 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3745 name, name_len, -1);
3746 if (IS_ERR_OR_NULL(di)) {
3747 if (!di)
3748 ret = -ENOENT;
3749 else
3750 ret = PTR_ERR(di);
3751 goto out;
3752 }
3753
3754 leaf = path->nodes[0];
3755 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3756 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
3757 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3758 if (ret) {
3759 btrfs_abort_transaction(trans, root, ret);
3760 goto out;
3761 }
3762 btrfs_release_path(path);
3763
3764 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
3765 objectid, root->root_key.objectid,
3766 dir_ino, &index, name, name_len);
3767 if (ret < 0) {
3768 if (ret != -ENOENT) {
3769 btrfs_abort_transaction(trans, root, ret);
3770 goto out;
3771 }
3772 di = btrfs_search_dir_index_item(root, path, dir_ino,
3773 name, name_len);
3774 if (IS_ERR_OR_NULL(di)) {
3775 if (!di)
3776 ret = -ENOENT;
3777 else
3778 ret = PTR_ERR(di);
3779 btrfs_abort_transaction(trans, root, ret);
3780 goto out;
3781 }
3782
3783 leaf = path->nodes[0];
3784 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3785 btrfs_release_path(path);
3786 index = key.offset;
3787 }
3788 btrfs_release_path(path);
3789
3790 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3791 if (ret) {
3792 btrfs_abort_transaction(trans, root, ret);
3793 goto out;
3794 }
3795
3796 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3797 inode_inc_iversion(dir);
3798 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3799 ret = btrfs_update_inode_fallback(trans, root, dir);
3800 if (ret)
3801 btrfs_abort_transaction(trans, root, ret);
3802 out:
3803 btrfs_free_path(path);
3804 return ret;
3805 }
3806
3807 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
3808 {
3809 struct inode *inode = dentry->d_inode;
3810 int err = 0;
3811 struct btrfs_root *root = BTRFS_I(dir)->root;
3812 struct btrfs_trans_handle *trans;
3813
3814 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
3815 return -ENOTEMPTY;
3816 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
3817 return -EPERM;
3818
3819 trans = __unlink_start_trans(dir);
3820 if (IS_ERR(trans))
3821 return PTR_ERR(trans);
3822
3823 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
3824 err = btrfs_unlink_subvol(trans, root, dir,
3825 BTRFS_I(inode)->location.objectid,
3826 dentry->d_name.name,
3827 dentry->d_name.len);
3828 goto out;
3829 }
3830
3831 err = btrfs_orphan_add(trans, inode);
3832 if (err)
3833 goto out;
3834
3835 /* now the directory is empty */
3836 err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3837 dentry->d_name.name, dentry->d_name.len);
3838 if (!err)
3839 btrfs_i_size_write(inode, 0);
3840 out:
3841 btrfs_end_transaction(trans, root);
3842 btrfs_btree_balance_dirty(root);
3843
3844 return err;
3845 }
3846
3847 /*
3848 * this can truncate away extent items, csum items and directory items.
3849 * It starts at a high offset and removes keys until it can't find
3850 * any higher than new_size
3851 *
3852 * csum items that cross the new i_size are truncated to the new size
3853 * as well.
3854 *
3855 * min_type is the minimum key type to truncate down to. If set to 0, this
3856 * will kill all the items on this inode, including the INODE_ITEM_KEY.
3857 */
3858 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
3859 struct btrfs_root *root,
3860 struct inode *inode,
3861 u64 new_size, u32 min_type)
3862 {
3863 struct btrfs_path *path;
3864 struct extent_buffer *leaf;
3865 struct btrfs_file_extent_item *fi;
3866 struct btrfs_key key;
3867 struct btrfs_key found_key;
3868 u64 extent_start = 0;
3869 u64 extent_num_bytes = 0;
3870 u64 extent_offset = 0;
3871 u64 item_end = 0;
3872 u64 last_size = (u64)-1;
3873 u32 found_type = (u8)-1;
3874 int found_extent;
3875 int del_item;
3876 int pending_del_nr = 0;
3877 int pending_del_slot = 0;
3878 int extent_type = -1;
3879 int ret;
3880 int err = 0;
3881 u64 ino = btrfs_ino(inode);
3882
3883 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
3884
3885 path = btrfs_alloc_path();
3886 if (!path)
3887 return -ENOMEM;
3888 path->reada = -1;
3889
3890 /*
3891 * We want to drop from the next block forward in case this new size is
3892 * not block aligned since we will be keeping the last block of the
3893 * extent just the way it is.
3894 */
3895 if (root->ref_cows || root == root->fs_info->tree_root)
3896 btrfs_drop_extent_cache(inode, ALIGN(new_size,
3897 root->sectorsize), (u64)-1, 0);
3898
3899 /*
3900 * This function is also used to drop the items in the log tree before
3901 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
3902 * it is used to drop the loged items. So we shouldn't kill the delayed
3903 * items.
3904 */
3905 if (min_type == 0 && root == BTRFS_I(inode)->root)
3906 btrfs_kill_delayed_inode_items(inode);
3907
3908 key.objectid = ino;
3909 key.offset = (u64)-1;
3910 key.type = (u8)-1;
3911
3912 search_again:
3913 path->leave_spinning = 1;
3914 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3915 if (ret < 0) {
3916 err = ret;
3917 goto out;
3918 }
3919
3920 if (ret > 0) {
3921 /* there are no items in the tree for us to truncate, we're
3922 * done
3923 */
3924 if (path->slots[0] == 0)
3925 goto out;
3926 path->slots[0]--;
3927 }
3928
3929 while (1) {
3930 fi = NULL;
3931 leaf = path->nodes[0];
3932 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3933 found_type = btrfs_key_type(&found_key);
3934
3935 if (found_key.objectid != ino)
3936 break;
3937
3938 if (found_type < min_type)
3939 break;
3940
3941 item_end = found_key.offset;
3942 if (found_type == BTRFS_EXTENT_DATA_KEY) {
3943 fi = btrfs_item_ptr(leaf, path->slots[0],
3944 struct btrfs_file_extent_item);
3945 extent_type = btrfs_file_extent_type(leaf, fi);
3946 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
3947 item_end +=
3948 btrfs_file_extent_num_bytes(leaf, fi);
3949 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
3950 item_end += btrfs_file_extent_inline_len(leaf,
3951 fi);
3952 }
3953 item_end--;
3954 }
3955 if (found_type > min_type) {
3956 del_item = 1;
3957 } else {
3958 if (item_end < new_size)
3959 break;
3960 if (found_key.offset >= new_size)
3961 del_item = 1;
3962 else
3963 del_item = 0;
3964 }
3965 found_extent = 0;
3966 /* FIXME, shrink the extent if the ref count is only 1 */
3967 if (found_type != BTRFS_EXTENT_DATA_KEY)
3968 goto delete;
3969
3970 if (del_item)
3971 last_size = found_key.offset;
3972 else
3973 last_size = new_size;
3974
3975 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
3976 u64 num_dec;
3977 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
3978 if (!del_item) {
3979 u64 orig_num_bytes =
3980 btrfs_file_extent_num_bytes(leaf, fi);
3981 extent_num_bytes = ALIGN(new_size -
3982 found_key.offset,
3983 root->sectorsize);
3984 btrfs_set_file_extent_num_bytes(leaf, fi,
3985 extent_num_bytes);
3986 num_dec = (orig_num_bytes -
3987 extent_num_bytes);
3988 if (root->ref_cows && extent_start != 0)
3989 inode_sub_bytes(inode, num_dec);
3990 btrfs_mark_buffer_dirty(leaf);
3991 } else {
3992 extent_num_bytes =
3993 btrfs_file_extent_disk_num_bytes(leaf,
3994 fi);
3995 extent_offset = found_key.offset -
3996 btrfs_file_extent_offset(leaf, fi);
3997
3998 /* FIXME blocksize != 4096 */
3999 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4000 if (extent_start != 0) {
4001 found_extent = 1;
4002 if (root->ref_cows)
4003 inode_sub_bytes(inode, num_dec);
4004 }
4005 }
4006 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4007 /*
4008 * we can't truncate inline items that have had
4009 * special encodings
4010 */
4011 if (!del_item &&
4012 btrfs_file_extent_compression(leaf, fi) == 0 &&
4013 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4014 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4015 u32 size = new_size - found_key.offset;
4016
4017 if (root->ref_cows) {
4018 inode_sub_bytes(inode, item_end + 1 -
4019 new_size);
4020 }
4021 size =
4022 btrfs_file_extent_calc_inline_size(size);
4023 btrfs_truncate_item(root, path, size, 1);
4024 } else if (root->ref_cows) {
4025 inode_sub_bytes(inode, item_end + 1 -
4026 found_key.offset);
4027 }
4028 }
4029 delete:
4030 if (del_item) {
4031 if (!pending_del_nr) {
4032 /* no pending yet, add ourselves */
4033 pending_del_slot = path->slots[0];
4034 pending_del_nr = 1;
4035 } else if (pending_del_nr &&
4036 path->slots[0] + 1 == pending_del_slot) {
4037 /* hop on the pending chunk */
4038 pending_del_nr++;
4039 pending_del_slot = path->slots[0];
4040 } else {
4041 BUG();
4042 }
4043 } else {
4044 break;
4045 }
4046 if (found_extent && (root->ref_cows ||
4047 root == root->fs_info->tree_root)) {
4048 btrfs_set_path_blocking(path);
4049 ret = btrfs_free_extent(trans, root, extent_start,
4050 extent_num_bytes, 0,
4051 btrfs_header_owner(leaf),
4052 ino, extent_offset, 0);
4053 BUG_ON(ret);
4054 }
4055
4056 if (found_type == BTRFS_INODE_ITEM_KEY)
4057 break;
4058
4059 if (path->slots[0] == 0 ||
4060 path->slots[0] != pending_del_slot) {
4061 if (pending_del_nr) {
4062 ret = btrfs_del_items(trans, root, path,
4063 pending_del_slot,
4064 pending_del_nr);
4065 if (ret) {
4066 btrfs_abort_transaction(trans,
4067 root, ret);
4068 goto error;
4069 }
4070 pending_del_nr = 0;
4071 }
4072 btrfs_release_path(path);
4073 goto search_again;
4074 } else {
4075 path->slots[0]--;
4076 }
4077 }
4078 out:
4079 if (pending_del_nr) {
4080 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4081 pending_del_nr);
4082 if (ret)
4083 btrfs_abort_transaction(trans, root, ret);
4084 }
4085 error:
4086 if (last_size != (u64)-1)
4087 btrfs_ordered_update_i_size(inode, last_size, NULL);
4088 btrfs_free_path(path);
4089 return err;
4090 }
4091
4092 /*
4093 * btrfs_truncate_page - read, zero a chunk and write a page
4094 * @inode - inode that we're zeroing
4095 * @from - the offset to start zeroing
4096 * @len - the length to zero, 0 to zero the entire range respective to the
4097 * offset
4098 * @front - zero up to the offset instead of from the offset on
4099 *
4100 * This will find the page for the "from" offset and cow the page and zero the
4101 * part we want to zero. This is used with truncate and hole punching.
4102 */
4103 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
4104 int front)
4105 {
4106 struct address_space *mapping = inode->i_mapping;
4107 struct btrfs_root *root = BTRFS_I(inode)->root;
4108 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4109 struct btrfs_ordered_extent *ordered;
4110 struct extent_state *cached_state = NULL;
4111 char *kaddr;
4112 u32 blocksize = root->sectorsize;
4113 pgoff_t index = from >> PAGE_CACHE_SHIFT;
4114 unsigned offset = from & (PAGE_CACHE_SIZE-1);
4115 struct page *page;
4116 gfp_t mask = btrfs_alloc_write_mask(mapping);
4117 int ret = 0;
4118 u64 page_start;
4119 u64 page_end;
4120
4121 if ((offset & (blocksize - 1)) == 0 &&
4122 (!len || ((len & (blocksize - 1)) == 0)))
4123 goto out;
4124 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
4125 if (ret)
4126 goto out;
4127
4128 again:
4129 page = find_or_create_page(mapping, index, mask);
4130 if (!page) {
4131 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4132 ret = -ENOMEM;
4133 goto out;
4134 }
4135
4136 page_start = page_offset(page);
4137 page_end = page_start + PAGE_CACHE_SIZE - 1;
4138
4139 if (!PageUptodate(page)) {
4140 ret = btrfs_readpage(NULL, page);
4141 lock_page(page);
4142 if (page->mapping != mapping) {
4143 unlock_page(page);
4144 page_cache_release(page);
4145 goto again;
4146 }
4147 if (!PageUptodate(page)) {
4148 ret = -EIO;
4149 goto out_unlock;
4150 }
4151 }
4152 wait_on_page_writeback(page);
4153
4154 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
4155 set_page_extent_mapped(page);
4156
4157 ordered = btrfs_lookup_ordered_extent(inode, page_start);
4158 if (ordered) {
4159 unlock_extent_cached(io_tree, page_start, page_end,
4160 &cached_state, GFP_NOFS);
4161 unlock_page(page);
4162 page_cache_release(page);
4163 btrfs_start_ordered_extent(inode, ordered, 1);
4164 btrfs_put_ordered_extent(ordered);
4165 goto again;
4166 }
4167
4168 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
4169 EXTENT_DIRTY | EXTENT_DELALLOC |
4170 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4171 0, 0, &cached_state, GFP_NOFS);
4172
4173 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
4174 &cached_state);
4175 if (ret) {
4176 unlock_extent_cached(io_tree, page_start, page_end,
4177 &cached_state, GFP_NOFS);
4178 goto out_unlock;
4179 }
4180
4181 if (offset != PAGE_CACHE_SIZE) {
4182 if (!len)
4183 len = PAGE_CACHE_SIZE - offset;
4184 kaddr = kmap(page);
4185 if (front)
4186 memset(kaddr, 0, offset);
4187 else
4188 memset(kaddr + offset, 0, len);
4189 flush_dcache_page(page);
4190 kunmap(page);
4191 }
4192 ClearPageChecked(page);
4193 set_page_dirty(page);
4194 unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
4195 GFP_NOFS);
4196
4197 out_unlock:
4198 if (ret)
4199 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4200 unlock_page(page);
4201 page_cache_release(page);
4202 out:
4203 return ret;
4204 }
4205
4206 /*
4207 * This function puts in dummy file extents for the area we're creating a hole
4208 * for. So if we are truncating this file to a larger size we need to insert
4209 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4210 * the range between oldsize and size
4211 */
4212 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4213 {
4214 struct btrfs_trans_handle *trans;
4215 struct btrfs_root *root = BTRFS_I(inode)->root;
4216 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4217 struct extent_map *em = NULL;
4218 struct extent_state *cached_state = NULL;
4219 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4220 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4221 u64 block_end = ALIGN(size, root->sectorsize);
4222 u64 last_byte;
4223 u64 cur_offset;
4224 u64 hole_size;
4225 int err = 0;
4226
4227 /*
4228 * If our size started in the middle of a page we need to zero out the
4229 * rest of the page before we expand the i_size, otherwise we could
4230 * expose stale data.
4231 */
4232 err = btrfs_truncate_page(inode, oldsize, 0, 0);
4233 if (err)
4234 return err;
4235
4236 if (size <= hole_start)
4237 return 0;
4238
4239 while (1) {
4240 struct btrfs_ordered_extent *ordered;
4241
4242 lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
4243 &cached_state);
4244 ordered = btrfs_lookup_ordered_range(inode, hole_start,
4245 block_end - hole_start);
4246 if (!ordered)
4247 break;
4248 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4249 &cached_state, GFP_NOFS);
4250 btrfs_start_ordered_extent(inode, ordered, 1);
4251 btrfs_put_ordered_extent(ordered);
4252 }
4253
4254 cur_offset = hole_start;
4255 while (1) {
4256 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4257 block_end - cur_offset, 0);
4258 if (IS_ERR(em)) {
4259 err = PTR_ERR(em);
4260 em = NULL;
4261 break;
4262 }
4263 last_byte = min(extent_map_end(em), block_end);
4264 last_byte = ALIGN(last_byte , root->sectorsize);
4265 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4266 struct extent_map *hole_em;
4267 hole_size = last_byte - cur_offset;
4268
4269 trans = btrfs_start_transaction(root, 3);
4270 if (IS_ERR(trans)) {
4271 err = PTR_ERR(trans);
4272 break;
4273 }
4274
4275 err = btrfs_drop_extents(trans, root, inode,
4276 cur_offset,
4277 cur_offset + hole_size, 1);
4278 if (err) {
4279 btrfs_abort_transaction(trans, root, err);
4280 btrfs_end_transaction(trans, root);
4281 break;
4282 }
4283
4284 err = btrfs_insert_file_extent(trans, root,
4285 btrfs_ino(inode), cur_offset, 0,
4286 0, hole_size, 0, hole_size,
4287 0, 0, 0);
4288 if (err) {
4289 btrfs_abort_transaction(trans, root, err);
4290 btrfs_end_transaction(trans, root);
4291 break;
4292 }
4293
4294 btrfs_drop_extent_cache(inode, cur_offset,
4295 cur_offset + hole_size - 1, 0);
4296 hole_em = alloc_extent_map();
4297 if (!hole_em) {
4298 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4299 &BTRFS_I(inode)->runtime_flags);
4300 goto next;
4301 }
4302 hole_em->start = cur_offset;
4303 hole_em->len = hole_size;
4304 hole_em->orig_start = cur_offset;
4305
4306 hole_em->block_start = EXTENT_MAP_HOLE;
4307 hole_em->block_len = 0;
4308 hole_em->orig_block_len = 0;
4309 hole_em->ram_bytes = hole_size;
4310 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4311 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4312 hole_em->generation = trans->transid;
4313
4314 while (1) {
4315 write_lock(&em_tree->lock);
4316 err = add_extent_mapping(em_tree, hole_em, 1);
4317 write_unlock(&em_tree->lock);
4318 if (err != -EEXIST)
4319 break;
4320 btrfs_drop_extent_cache(inode, cur_offset,
4321 cur_offset +
4322 hole_size - 1, 0);
4323 }
4324 free_extent_map(hole_em);
4325 next:
4326 btrfs_update_inode(trans, root, inode);
4327 btrfs_end_transaction(trans, root);
4328 }
4329 free_extent_map(em);
4330 em = NULL;
4331 cur_offset = last_byte;
4332 if (cur_offset >= block_end)
4333 break;
4334 }
4335
4336 free_extent_map(em);
4337 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4338 GFP_NOFS);
4339 return err;
4340 }
4341
4342 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4343 {
4344 struct btrfs_root *root = BTRFS_I(inode)->root;
4345 struct btrfs_trans_handle *trans;
4346 loff_t oldsize = i_size_read(inode);
4347 loff_t newsize = attr->ia_size;
4348 int mask = attr->ia_valid;
4349 int ret;
4350
4351 /*
4352 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4353 * special case where we need to update the times despite not having
4354 * these flags set. For all other operations the VFS set these flags
4355 * explicitly if it wants a timestamp update.
4356 */
4357 if (newsize != oldsize && (!(mask & (ATTR_CTIME | ATTR_MTIME))))
4358 inode->i_ctime = inode->i_mtime = current_fs_time(inode->i_sb);
4359
4360 if (newsize > oldsize) {
4361 truncate_pagecache(inode, newsize);
4362 ret = btrfs_cont_expand(inode, oldsize, newsize);
4363 if (ret)
4364 return ret;
4365
4366 trans = btrfs_start_transaction(root, 1);
4367 if (IS_ERR(trans))
4368 return PTR_ERR(trans);
4369
4370 i_size_write(inode, newsize);
4371 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4372 ret = btrfs_update_inode(trans, root, inode);
4373 btrfs_end_transaction(trans, root);
4374 } else {
4375
4376 /*
4377 * We're truncating a file that used to have good data down to
4378 * zero. Make sure it gets into the ordered flush list so that
4379 * any new writes get down to disk quickly.
4380 */
4381 if (newsize == 0)
4382 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
4383 &BTRFS_I(inode)->runtime_flags);
4384
4385 /*
4386 * 1 for the orphan item we're going to add
4387 * 1 for the orphan item deletion.
4388 */
4389 trans = btrfs_start_transaction(root, 2);
4390 if (IS_ERR(trans))
4391 return PTR_ERR(trans);
4392
4393 /*
4394 * We need to do this in case we fail at _any_ point during the
4395 * actual truncate. Once we do the truncate_setsize we could
4396 * invalidate pages which forces any outstanding ordered io to
4397 * be instantly completed which will give us extents that need
4398 * to be truncated. If we fail to get an orphan inode down we
4399 * could have left over extents that were never meant to live,
4400 * so we need to garuntee from this point on that everything
4401 * will be consistent.
4402 */
4403 ret = btrfs_orphan_add(trans, inode);
4404 btrfs_end_transaction(trans, root);
4405 if (ret)
4406 return ret;
4407
4408 /* we don't support swapfiles, so vmtruncate shouldn't fail */
4409 truncate_setsize(inode, newsize);
4410
4411 /* Disable nonlocked read DIO to avoid the end less truncate */
4412 btrfs_inode_block_unlocked_dio(inode);
4413 inode_dio_wait(inode);
4414 btrfs_inode_resume_unlocked_dio(inode);
4415
4416 ret = btrfs_truncate(inode);
4417 if (ret && inode->i_nlink) {
4418 int err;
4419
4420 /*
4421 * failed to truncate, disk_i_size is only adjusted down
4422 * as we remove extents, so it should represent the true
4423 * size of the inode, so reset the in memory size and
4424 * delete our orphan entry.
4425 */
4426 trans = btrfs_join_transaction(root);
4427 if (IS_ERR(trans)) {
4428 btrfs_orphan_del(NULL, inode);
4429 return ret;
4430 }
4431 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
4432 err = btrfs_orphan_del(trans, inode);
4433 if (err)
4434 btrfs_abort_transaction(trans, root, err);
4435 btrfs_end_transaction(trans, root);
4436 }
4437 }
4438
4439 return ret;
4440 }
4441
4442 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
4443 {
4444 struct inode *inode = dentry->d_inode;
4445 struct btrfs_root *root = BTRFS_I(inode)->root;
4446 int err;
4447
4448 if (btrfs_root_readonly(root))
4449 return -EROFS;
4450
4451 err = inode_change_ok(inode, attr);
4452 if (err)
4453 return err;
4454
4455 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
4456 err = btrfs_setsize(inode, attr);
4457 if (err)
4458 return err;
4459 }
4460
4461 if (attr->ia_valid) {
4462 setattr_copy(inode, attr);
4463 inode_inc_iversion(inode);
4464 err = btrfs_dirty_inode(inode);
4465
4466 if (!err && attr->ia_valid & ATTR_MODE)
4467 err = btrfs_acl_chmod(inode);
4468 }
4469
4470 return err;
4471 }
4472
4473 void btrfs_evict_inode(struct inode *inode)
4474 {
4475 struct btrfs_trans_handle *trans;
4476 struct btrfs_root *root = BTRFS_I(inode)->root;
4477 struct btrfs_block_rsv *rsv, *global_rsv;
4478 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
4479 int ret;
4480
4481 trace_btrfs_inode_evict(inode);
4482
4483 truncate_inode_pages(&inode->i_data, 0);
4484 if (inode->i_nlink &&
4485 ((btrfs_root_refs(&root->root_item) != 0 &&
4486 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
4487 btrfs_is_free_space_inode(inode)))
4488 goto no_delete;
4489
4490 if (is_bad_inode(inode)) {
4491 btrfs_orphan_del(NULL, inode);
4492 goto no_delete;
4493 }
4494 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
4495 btrfs_wait_ordered_range(inode, 0, (u64)-1);
4496
4497 if (root->fs_info->log_root_recovering) {
4498 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
4499 &BTRFS_I(inode)->runtime_flags));
4500 goto no_delete;
4501 }
4502
4503 if (inode->i_nlink > 0) {
4504 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
4505 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
4506 goto no_delete;
4507 }
4508
4509 ret = btrfs_commit_inode_delayed_inode(inode);
4510 if (ret) {
4511 btrfs_orphan_del(NULL, inode);
4512 goto no_delete;
4513 }
4514
4515 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
4516 if (!rsv) {
4517 btrfs_orphan_del(NULL, inode);
4518 goto no_delete;
4519 }
4520 rsv->size = min_size;
4521 rsv->failfast = 1;
4522 global_rsv = &root->fs_info->global_block_rsv;
4523
4524 btrfs_i_size_write(inode, 0);
4525
4526 /*
4527 * This is a bit simpler than btrfs_truncate since we've already
4528 * reserved our space for our orphan item in the unlink, so we just
4529 * need to reserve some slack space in case we add bytes and update
4530 * inode item when doing the truncate.
4531 */
4532 while (1) {
4533 ret = btrfs_block_rsv_refill(root, rsv, min_size,
4534 BTRFS_RESERVE_FLUSH_LIMIT);
4535
4536 /*
4537 * Try and steal from the global reserve since we will
4538 * likely not use this space anyway, we want to try as
4539 * hard as possible to get this to work.
4540 */
4541 if (ret)
4542 ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size);
4543
4544 if (ret) {
4545 btrfs_warn(root->fs_info,
4546 "Could not get space for a delete, will truncate on mount %d",
4547 ret);
4548 btrfs_orphan_del(NULL, inode);
4549 btrfs_free_block_rsv(root, rsv);
4550 goto no_delete;
4551 }
4552
4553 trans = btrfs_join_transaction(root);
4554 if (IS_ERR(trans)) {
4555 btrfs_orphan_del(NULL, inode);
4556 btrfs_free_block_rsv(root, rsv);
4557 goto no_delete;
4558 }
4559
4560 trans->block_rsv = rsv;
4561
4562 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
4563 if (ret != -ENOSPC)
4564 break;
4565
4566 trans->block_rsv = &root->fs_info->trans_block_rsv;
4567 btrfs_end_transaction(trans, root);
4568 trans = NULL;
4569 btrfs_btree_balance_dirty(root);
4570 }
4571
4572 btrfs_free_block_rsv(root, rsv);
4573
4574 /*
4575 * Errors here aren't a big deal, it just means we leave orphan items
4576 * in the tree. They will be cleaned up on the next mount.
4577 */
4578 if (ret == 0) {
4579 trans->block_rsv = root->orphan_block_rsv;
4580 btrfs_orphan_del(trans, inode);
4581 } else {
4582 btrfs_orphan_del(NULL, inode);
4583 }
4584
4585 trans->block_rsv = &root->fs_info->trans_block_rsv;
4586 if (!(root == root->fs_info->tree_root ||
4587 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
4588 btrfs_return_ino(root, btrfs_ino(inode));
4589
4590 btrfs_end_transaction(trans, root);
4591 btrfs_btree_balance_dirty(root);
4592 no_delete:
4593 btrfs_remove_delayed_node(inode);
4594 clear_inode(inode);
4595 return;
4596 }
4597
4598 /*
4599 * this returns the key found in the dir entry in the location pointer.
4600 * If no dir entries were found, location->objectid is 0.
4601 */
4602 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
4603 struct btrfs_key *location)
4604 {
4605 const char *name = dentry->d_name.name;
4606 int namelen = dentry->d_name.len;
4607 struct btrfs_dir_item *di;
4608 struct btrfs_path *path;
4609 struct btrfs_root *root = BTRFS_I(dir)->root;
4610 int ret = 0;
4611
4612 path = btrfs_alloc_path();
4613 if (!path)
4614 return -ENOMEM;
4615
4616 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
4617 namelen, 0);
4618 if (IS_ERR(di))
4619 ret = PTR_ERR(di);
4620
4621 if (IS_ERR_OR_NULL(di))
4622 goto out_err;
4623
4624 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
4625 out:
4626 btrfs_free_path(path);
4627 return ret;
4628 out_err:
4629 location->objectid = 0;
4630 goto out;
4631 }
4632
4633 /*
4634 * when we hit a tree root in a directory, the btrfs part of the inode
4635 * needs to be changed to reflect the root directory of the tree root. This
4636 * is kind of like crossing a mount point.
4637 */
4638 static int fixup_tree_root_location(struct btrfs_root *root,
4639 struct inode *dir,
4640 struct dentry *dentry,
4641 struct btrfs_key *location,
4642 struct btrfs_root **sub_root)
4643 {
4644 struct btrfs_path *path;
4645 struct btrfs_root *new_root;
4646 struct btrfs_root_ref *ref;
4647 struct extent_buffer *leaf;
4648 int ret;
4649 int err = 0;
4650
4651 path = btrfs_alloc_path();
4652 if (!path) {
4653 err = -ENOMEM;
4654 goto out;
4655 }
4656
4657 err = -ENOENT;
4658 ret = btrfs_find_root_ref(root->fs_info->tree_root, path,
4659 BTRFS_I(dir)->root->root_key.objectid,
4660 location->objectid);
4661 if (ret) {
4662 if (ret < 0)
4663 err = ret;
4664 goto out;
4665 }
4666
4667 leaf = path->nodes[0];
4668 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
4669 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
4670 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
4671 goto out;
4672
4673 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
4674 (unsigned long)(ref + 1),
4675 dentry->d_name.len);
4676 if (ret)
4677 goto out;
4678
4679 btrfs_release_path(path);
4680
4681 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
4682 if (IS_ERR(new_root)) {
4683 err = PTR_ERR(new_root);
4684 goto out;
4685 }
4686
4687 *sub_root = new_root;
4688 location->objectid = btrfs_root_dirid(&new_root->root_item);
4689 location->type = BTRFS_INODE_ITEM_KEY;
4690 location->offset = 0;
4691 err = 0;
4692 out:
4693 btrfs_free_path(path);
4694 return err;
4695 }
4696
4697 static void inode_tree_add(struct inode *inode)
4698 {
4699 struct btrfs_root *root = BTRFS_I(inode)->root;
4700 struct btrfs_inode *entry;
4701 struct rb_node **p;
4702 struct rb_node *parent;
4703 struct rb_node *new = &BTRFS_I(inode)->rb_node;
4704 u64 ino = btrfs_ino(inode);
4705
4706 if (inode_unhashed(inode))
4707 return;
4708 parent = NULL;
4709 spin_lock(&root->inode_lock);
4710 p = &root->inode_tree.rb_node;
4711 while (*p) {
4712 parent = *p;
4713 entry = rb_entry(parent, struct btrfs_inode, rb_node);
4714
4715 if (ino < btrfs_ino(&entry->vfs_inode))
4716 p = &parent->rb_left;
4717 else if (ino > btrfs_ino(&entry->vfs_inode))
4718 p = &parent->rb_right;
4719 else {
4720 WARN_ON(!(entry->vfs_inode.i_state &
4721 (I_WILL_FREE | I_FREEING)));
4722 rb_replace_node(parent, new, &root->inode_tree);
4723 RB_CLEAR_NODE(parent);
4724 spin_unlock(&root->inode_lock);
4725 return;
4726 }
4727 }
4728 rb_link_node(new, parent, p);
4729 rb_insert_color(new, &root->inode_tree);
4730 spin_unlock(&root->inode_lock);
4731 }
4732
4733 static void inode_tree_del(struct inode *inode)
4734 {
4735 struct btrfs_root *root = BTRFS_I(inode)->root;
4736 int empty = 0;
4737
4738 spin_lock(&root->inode_lock);
4739 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
4740 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
4741 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
4742 empty = RB_EMPTY_ROOT(&root->inode_tree);
4743 }
4744 spin_unlock(&root->inode_lock);
4745
4746 if (empty && btrfs_root_refs(&root->root_item) == 0) {
4747 synchronize_srcu(&root->fs_info->subvol_srcu);
4748 spin_lock(&root->inode_lock);
4749 empty = RB_EMPTY_ROOT(&root->inode_tree);
4750 spin_unlock(&root->inode_lock);
4751 if (empty)
4752 btrfs_add_dead_root(root);
4753 }
4754 }
4755
4756 void btrfs_invalidate_inodes(struct btrfs_root *root)
4757 {
4758 struct rb_node *node;
4759 struct rb_node *prev;
4760 struct btrfs_inode *entry;
4761 struct inode *inode;
4762 u64 objectid = 0;
4763
4764 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
4765
4766 spin_lock(&root->inode_lock);
4767 again:
4768 node = root->inode_tree.rb_node;
4769 prev = NULL;
4770 while (node) {
4771 prev = node;
4772 entry = rb_entry(node, struct btrfs_inode, rb_node);
4773
4774 if (objectid < btrfs_ino(&entry->vfs_inode))
4775 node = node->rb_left;
4776 else if (objectid > btrfs_ino(&entry->vfs_inode))
4777 node = node->rb_right;
4778 else
4779 break;
4780 }
4781 if (!node) {
4782 while (prev) {
4783 entry = rb_entry(prev, struct btrfs_inode, rb_node);
4784 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
4785 node = prev;
4786 break;
4787 }
4788 prev = rb_next(prev);
4789 }
4790 }
4791 while (node) {
4792 entry = rb_entry(node, struct btrfs_inode, rb_node);
4793 objectid = btrfs_ino(&entry->vfs_inode) + 1;
4794 inode = igrab(&entry->vfs_inode);
4795 if (inode) {
4796 spin_unlock(&root->inode_lock);
4797 if (atomic_read(&inode->i_count) > 1)
4798 d_prune_aliases(inode);
4799 /*
4800 * btrfs_drop_inode will have it removed from
4801 * the inode cache when its usage count
4802 * hits zero.
4803 */
4804 iput(inode);
4805 cond_resched();
4806 spin_lock(&root->inode_lock);
4807 goto again;
4808 }
4809
4810 if (cond_resched_lock(&root->inode_lock))
4811 goto again;
4812
4813 node = rb_next(node);
4814 }
4815 spin_unlock(&root->inode_lock);
4816 }
4817
4818 static int btrfs_init_locked_inode(struct inode *inode, void *p)
4819 {
4820 struct btrfs_iget_args *args = p;
4821 inode->i_ino = args->ino;
4822 BTRFS_I(inode)->root = args->root;
4823 return 0;
4824 }
4825
4826 static int btrfs_find_actor(struct inode *inode, void *opaque)
4827 {
4828 struct btrfs_iget_args *args = opaque;
4829 return args->ino == btrfs_ino(inode) &&
4830 args->root == BTRFS_I(inode)->root;
4831 }
4832
4833 static struct inode *btrfs_iget_locked(struct super_block *s,
4834 u64 objectid,
4835 struct btrfs_root *root)
4836 {
4837 struct inode *inode;
4838 struct btrfs_iget_args args;
4839 unsigned long hashval = btrfs_inode_hash(objectid, root);
4840
4841 args.ino = objectid;
4842 args.root = root;
4843
4844 inode = iget5_locked(s, hashval, btrfs_find_actor,
4845 btrfs_init_locked_inode,
4846 (void *)&args);
4847 return inode;
4848 }
4849
4850 /* Get an inode object given its location and corresponding root.
4851 * Returns in *is_new if the inode was read from disk
4852 */
4853 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
4854 struct btrfs_root *root, int *new)
4855 {
4856 struct inode *inode;
4857
4858 inode = btrfs_iget_locked(s, location->objectid, root);
4859 if (!inode)
4860 return ERR_PTR(-ENOMEM);
4861
4862 if (inode->i_state & I_NEW) {
4863 BTRFS_I(inode)->root = root;
4864 memcpy(&BTRFS_I(inode)->location, location, sizeof(*location));
4865 btrfs_read_locked_inode(inode);
4866 if (!is_bad_inode(inode)) {
4867 inode_tree_add(inode);
4868 unlock_new_inode(inode);
4869 if (new)
4870 *new = 1;
4871 } else {
4872 unlock_new_inode(inode);
4873 iput(inode);
4874 inode = ERR_PTR(-ESTALE);
4875 }
4876 }
4877
4878 return inode;
4879 }
4880
4881 static struct inode *new_simple_dir(struct super_block *s,
4882 struct btrfs_key *key,
4883 struct btrfs_root *root)
4884 {
4885 struct inode *inode = new_inode(s);
4886
4887 if (!inode)
4888 return ERR_PTR(-ENOMEM);
4889
4890 BTRFS_I(inode)->root = root;
4891 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
4892 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
4893
4894 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
4895 inode->i_op = &btrfs_dir_ro_inode_operations;
4896 inode->i_fop = &simple_dir_operations;
4897 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
4898 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
4899
4900 return inode;
4901 }
4902
4903 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
4904 {
4905 struct inode *inode;
4906 struct btrfs_root *root = BTRFS_I(dir)->root;
4907 struct btrfs_root *sub_root = root;
4908 struct btrfs_key location;
4909 int index;
4910 int ret = 0;
4911
4912 if (dentry->d_name.len > BTRFS_NAME_LEN)
4913 return ERR_PTR(-ENAMETOOLONG);
4914
4915 ret = btrfs_inode_by_name(dir, dentry, &location);
4916 if (ret < 0)
4917 return ERR_PTR(ret);
4918
4919 if (location.objectid == 0)
4920 return NULL;
4921
4922 if (location.type == BTRFS_INODE_ITEM_KEY) {
4923 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
4924 return inode;
4925 }
4926
4927 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
4928
4929 index = srcu_read_lock(&root->fs_info->subvol_srcu);
4930 ret = fixup_tree_root_location(root, dir, dentry,
4931 &location, &sub_root);
4932 if (ret < 0) {
4933 if (ret != -ENOENT)
4934 inode = ERR_PTR(ret);
4935 else
4936 inode = new_simple_dir(dir->i_sb, &location, sub_root);
4937 } else {
4938 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
4939 }
4940 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
4941
4942 if (!IS_ERR(inode) && root != sub_root) {
4943 down_read(&root->fs_info->cleanup_work_sem);
4944 if (!(inode->i_sb->s_flags & MS_RDONLY))
4945 ret = btrfs_orphan_cleanup(sub_root);
4946 up_read(&root->fs_info->cleanup_work_sem);
4947 if (ret) {
4948 iput(inode);
4949 inode = ERR_PTR(ret);
4950 }
4951 }
4952
4953 return inode;
4954 }
4955
4956 static int btrfs_dentry_delete(const struct dentry *dentry)
4957 {
4958 struct btrfs_root *root;
4959 struct inode *inode = dentry->d_inode;
4960
4961 if (!inode && !IS_ROOT(dentry))
4962 inode = dentry->d_parent->d_inode;
4963
4964 if (inode) {
4965 root = BTRFS_I(inode)->root;
4966 if (btrfs_root_refs(&root->root_item) == 0)
4967 return 1;
4968
4969 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
4970 return 1;
4971 }
4972 return 0;
4973 }
4974
4975 static void btrfs_dentry_release(struct dentry *dentry)
4976 {
4977 if (dentry->d_fsdata)
4978 kfree(dentry->d_fsdata);
4979 }
4980
4981 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
4982 unsigned int flags)
4983 {
4984 struct dentry *ret;
4985
4986 ret = d_splice_alias(btrfs_lookup_dentry(dir, dentry), dentry);
4987 return ret;
4988 }
4989
4990 unsigned char btrfs_filetype_table[] = {
4991 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
4992 };
4993
4994 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
4995 {
4996 struct inode *inode = file_inode(file);
4997 struct btrfs_root *root = BTRFS_I(inode)->root;
4998 struct btrfs_item *item;
4999 struct btrfs_dir_item *di;
5000 struct btrfs_key key;
5001 struct btrfs_key found_key;
5002 struct btrfs_path *path;
5003 struct list_head ins_list;
5004 struct list_head del_list;
5005 int ret;
5006 struct extent_buffer *leaf;
5007 int slot;
5008 unsigned char d_type;
5009 int over = 0;
5010 u32 di_cur;
5011 u32 di_total;
5012 u32 di_len;
5013 int key_type = BTRFS_DIR_INDEX_KEY;
5014 char tmp_name[32];
5015 char *name_ptr;
5016 int name_len;
5017 int is_curr = 0; /* ctx->pos points to the current index? */
5018
5019 /* FIXME, use a real flag for deciding about the key type */
5020 if (root->fs_info->tree_root == root)
5021 key_type = BTRFS_DIR_ITEM_KEY;
5022
5023 if (!dir_emit_dots(file, ctx))
5024 return 0;
5025
5026 path = btrfs_alloc_path();
5027 if (!path)
5028 return -ENOMEM;
5029
5030 path->reada = 1;
5031
5032 if (key_type == BTRFS_DIR_INDEX_KEY) {
5033 INIT_LIST_HEAD(&ins_list);
5034 INIT_LIST_HEAD(&del_list);
5035 btrfs_get_delayed_items(inode, &ins_list, &del_list);
5036 }
5037
5038 btrfs_set_key_type(&key, key_type);
5039 key.offset = ctx->pos;
5040 key.objectid = btrfs_ino(inode);
5041
5042 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5043 if (ret < 0)
5044 goto err;
5045
5046 while (1) {
5047 leaf = path->nodes[0];
5048 slot = path->slots[0];
5049 if (slot >= btrfs_header_nritems(leaf)) {
5050 ret = btrfs_next_leaf(root, path);
5051 if (ret < 0)
5052 goto err;
5053 else if (ret > 0)
5054 break;
5055 continue;
5056 }
5057
5058 item = btrfs_item_nr(slot);
5059 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5060
5061 if (found_key.objectid != key.objectid)
5062 break;
5063 if (btrfs_key_type(&found_key) != key_type)
5064 break;
5065 if (found_key.offset < ctx->pos)
5066 goto next;
5067 if (key_type == BTRFS_DIR_INDEX_KEY &&
5068 btrfs_should_delete_dir_index(&del_list,
5069 found_key.offset))
5070 goto next;
5071
5072 ctx->pos = found_key.offset;
5073 is_curr = 1;
5074
5075 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5076 di_cur = 0;
5077 di_total = btrfs_item_size(leaf, item);
5078
5079 while (di_cur < di_total) {
5080 struct btrfs_key location;
5081
5082 if (verify_dir_item(root, leaf, di))
5083 break;
5084
5085 name_len = btrfs_dir_name_len(leaf, di);
5086 if (name_len <= sizeof(tmp_name)) {
5087 name_ptr = tmp_name;
5088 } else {
5089 name_ptr = kmalloc(name_len, GFP_NOFS);
5090 if (!name_ptr) {
5091 ret = -ENOMEM;
5092 goto err;
5093 }
5094 }
5095 read_extent_buffer(leaf, name_ptr,
5096 (unsigned long)(di + 1), name_len);
5097
5098 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5099 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5100
5101
5102 /* is this a reference to our own snapshot? If so
5103 * skip it.
5104 *
5105 * In contrast to old kernels, we insert the snapshot's
5106 * dir item and dir index after it has been created, so
5107 * we won't find a reference to our own snapshot. We
5108 * still keep the following code for backward
5109 * compatibility.
5110 */
5111 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5112 location.objectid == root->root_key.objectid) {
5113 over = 0;
5114 goto skip;
5115 }
5116 over = !dir_emit(ctx, name_ptr, name_len,
5117 location.objectid, d_type);
5118
5119 skip:
5120 if (name_ptr != tmp_name)
5121 kfree(name_ptr);
5122
5123 if (over)
5124 goto nopos;
5125 di_len = btrfs_dir_name_len(leaf, di) +
5126 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5127 di_cur += di_len;
5128 di = (struct btrfs_dir_item *)((char *)di + di_len);
5129 }
5130 next:
5131 path->slots[0]++;
5132 }
5133
5134 if (key_type == BTRFS_DIR_INDEX_KEY) {
5135 if (is_curr)
5136 ctx->pos++;
5137 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
5138 if (ret)
5139 goto nopos;
5140 }
5141
5142 /* Reached end of directory/root. Bump pos past the last item. */
5143 ctx->pos++;
5144
5145 /*
5146 * Stop new entries from being returned after we return the last
5147 * entry.
5148 *
5149 * New directory entries are assigned a strictly increasing
5150 * offset. This means that new entries created during readdir
5151 * are *guaranteed* to be seen in the future by that readdir.
5152 * This has broken buggy programs which operate on names as
5153 * they're returned by readdir. Until we re-use freed offsets
5154 * we have this hack to stop new entries from being returned
5155 * under the assumption that they'll never reach this huge
5156 * offset.
5157 *
5158 * This is being careful not to overflow 32bit loff_t unless the
5159 * last entry requires it because doing so has broken 32bit apps
5160 * in the past.
5161 */
5162 if (key_type == BTRFS_DIR_INDEX_KEY) {
5163 if (ctx->pos >= INT_MAX)
5164 ctx->pos = LLONG_MAX;
5165 else
5166 ctx->pos = INT_MAX;
5167 }
5168 nopos:
5169 ret = 0;
5170 err:
5171 if (key_type == BTRFS_DIR_INDEX_KEY)
5172 btrfs_put_delayed_items(&ins_list, &del_list);
5173 btrfs_free_path(path);
5174 return ret;
5175 }
5176
5177 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5178 {
5179 struct btrfs_root *root = BTRFS_I(inode)->root;
5180 struct btrfs_trans_handle *trans;
5181 int ret = 0;
5182 bool nolock = false;
5183
5184 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5185 return 0;
5186
5187 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5188 nolock = true;
5189
5190 if (wbc->sync_mode == WB_SYNC_ALL) {
5191 if (nolock)
5192 trans = btrfs_join_transaction_nolock(root);
5193 else
5194 trans = btrfs_join_transaction(root);
5195 if (IS_ERR(trans))
5196 return PTR_ERR(trans);
5197 ret = btrfs_commit_transaction(trans, root);
5198 }
5199 return ret;
5200 }
5201
5202 /*
5203 * This is somewhat expensive, updating the tree every time the
5204 * inode changes. But, it is most likely to find the inode in cache.
5205 * FIXME, needs more benchmarking...there are no reasons other than performance
5206 * to keep or drop this code.
5207 */
5208 static int btrfs_dirty_inode(struct inode *inode)
5209 {
5210 struct btrfs_root *root = BTRFS_I(inode)->root;
5211 struct btrfs_trans_handle *trans;
5212 int ret;
5213
5214 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5215 return 0;
5216
5217 trans = btrfs_join_transaction(root);
5218 if (IS_ERR(trans))
5219 return PTR_ERR(trans);
5220
5221 ret = btrfs_update_inode(trans, root, inode);
5222 if (ret && ret == -ENOSPC) {
5223 /* whoops, lets try again with the full transaction */
5224 btrfs_end_transaction(trans, root);
5225 trans = btrfs_start_transaction(root, 1);
5226 if (IS_ERR(trans))
5227 return PTR_ERR(trans);
5228
5229 ret = btrfs_update_inode(trans, root, inode);
5230 }
5231 btrfs_end_transaction(trans, root);
5232 if (BTRFS_I(inode)->delayed_node)
5233 btrfs_balance_delayed_items(root);
5234
5235 return ret;
5236 }
5237
5238 /*
5239 * This is a copy of file_update_time. We need this so we can return error on
5240 * ENOSPC for updating the inode in the case of file write and mmap writes.
5241 */
5242 static int btrfs_update_time(struct inode *inode, struct timespec *now,
5243 int flags)
5244 {
5245 struct btrfs_root *root = BTRFS_I(inode)->root;
5246
5247 if (btrfs_root_readonly(root))
5248 return -EROFS;
5249
5250 if (flags & S_VERSION)
5251 inode_inc_iversion(inode);
5252 if (flags & S_CTIME)
5253 inode->i_ctime = *now;
5254 if (flags & S_MTIME)
5255 inode->i_mtime = *now;
5256 if (flags & S_ATIME)
5257 inode->i_atime = *now;
5258 return btrfs_dirty_inode(inode);
5259 }
5260
5261 /*
5262 * find the highest existing sequence number in a directory
5263 * and then set the in-memory index_cnt variable to reflect
5264 * free sequence numbers
5265 */
5266 static int btrfs_set_inode_index_count(struct inode *inode)
5267 {
5268 struct btrfs_root *root = BTRFS_I(inode)->root;
5269 struct btrfs_key key, found_key;
5270 struct btrfs_path *path;
5271 struct extent_buffer *leaf;
5272 int ret;
5273
5274 key.objectid = btrfs_ino(inode);
5275 btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
5276 key.offset = (u64)-1;
5277
5278 path = btrfs_alloc_path();
5279 if (!path)
5280 return -ENOMEM;
5281
5282 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5283 if (ret < 0)
5284 goto out;
5285 /* FIXME: we should be able to handle this */
5286 if (ret == 0)
5287 goto out;
5288 ret = 0;
5289
5290 /*
5291 * MAGIC NUMBER EXPLANATION:
5292 * since we search a directory based on f_pos we have to start at 2
5293 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
5294 * else has to start at 2
5295 */
5296 if (path->slots[0] == 0) {
5297 BTRFS_I(inode)->index_cnt = 2;
5298 goto out;
5299 }
5300
5301 path->slots[0]--;
5302
5303 leaf = path->nodes[0];
5304 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5305
5306 if (found_key.objectid != btrfs_ino(inode) ||
5307 btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) {
5308 BTRFS_I(inode)->index_cnt = 2;
5309 goto out;
5310 }
5311
5312 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
5313 out:
5314 btrfs_free_path(path);
5315 return ret;
5316 }
5317
5318 /*
5319 * helper to find a free sequence number in a given directory. This current
5320 * code is very simple, later versions will do smarter things in the btree
5321 */
5322 int btrfs_set_inode_index(struct inode *dir, u64 *index)
5323 {
5324 int ret = 0;
5325
5326 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
5327 ret = btrfs_inode_delayed_dir_index_count(dir);
5328 if (ret) {
5329 ret = btrfs_set_inode_index_count(dir);
5330 if (ret)
5331 return ret;
5332 }
5333 }
5334
5335 *index = BTRFS_I(dir)->index_cnt;
5336 BTRFS_I(dir)->index_cnt++;
5337
5338 return ret;
5339 }
5340
5341 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
5342 struct btrfs_root *root,
5343 struct inode *dir,
5344 const char *name, int name_len,
5345 u64 ref_objectid, u64 objectid,
5346 umode_t mode, u64 *index)
5347 {
5348 struct inode *inode;
5349 struct btrfs_inode_item *inode_item;
5350 struct btrfs_key *location;
5351 struct btrfs_path *path;
5352 struct btrfs_inode_ref *ref;
5353 struct btrfs_key key[2];
5354 u32 sizes[2];
5355 unsigned long ptr;
5356 int ret;
5357 int owner;
5358
5359 path = btrfs_alloc_path();
5360 if (!path)
5361 return ERR_PTR(-ENOMEM);
5362
5363 inode = new_inode(root->fs_info->sb);
5364 if (!inode) {
5365 btrfs_free_path(path);
5366 return ERR_PTR(-ENOMEM);
5367 }
5368
5369 /*
5370 * we have to initialize this early, so we can reclaim the inode
5371 * number if we fail afterwards in this function.
5372 */
5373 inode->i_ino = objectid;
5374
5375 if (dir) {
5376 trace_btrfs_inode_request(dir);
5377
5378 ret = btrfs_set_inode_index(dir, index);
5379 if (ret) {
5380 btrfs_free_path(path);
5381 iput(inode);
5382 return ERR_PTR(ret);
5383 }
5384 }
5385 /*
5386 * index_cnt is ignored for everything but a dir,
5387 * btrfs_get_inode_index_count has an explanation for the magic
5388 * number
5389 */
5390 BTRFS_I(inode)->index_cnt = 2;
5391 BTRFS_I(inode)->root = root;
5392 BTRFS_I(inode)->generation = trans->transid;
5393 inode->i_generation = BTRFS_I(inode)->generation;
5394
5395 /*
5396 * We could have gotten an inode number from somebody who was fsynced
5397 * and then removed in this same transaction, so let's just set full
5398 * sync since it will be a full sync anyway and this will blow away the
5399 * old info in the log.
5400 */
5401 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
5402
5403 if (S_ISDIR(mode))
5404 owner = 0;
5405 else
5406 owner = 1;
5407
5408 key[0].objectid = objectid;
5409 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
5410 key[0].offset = 0;
5411
5412 /*
5413 * Start new inodes with an inode_ref. This is slightly more
5414 * efficient for small numbers of hard links since they will
5415 * be packed into one item. Extended refs will kick in if we
5416 * add more hard links than can fit in the ref item.
5417 */
5418 key[1].objectid = objectid;
5419 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
5420 key[1].offset = ref_objectid;
5421
5422 sizes[0] = sizeof(struct btrfs_inode_item);
5423 sizes[1] = name_len + sizeof(*ref);
5424
5425 path->leave_spinning = 1;
5426 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
5427 if (ret != 0)
5428 goto fail;
5429
5430 inode_init_owner(inode, dir, mode);
5431 inode_set_bytes(inode, 0);
5432 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
5433 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
5434 struct btrfs_inode_item);
5435 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
5436 sizeof(*inode_item));
5437 fill_inode_item(trans, path->nodes[0], inode_item, inode);
5438
5439 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
5440 struct btrfs_inode_ref);
5441 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
5442 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
5443 ptr = (unsigned long)(ref + 1);
5444 write_extent_buffer(path->nodes[0], name, ptr, name_len);
5445
5446 btrfs_mark_buffer_dirty(path->nodes[0]);
5447 btrfs_free_path(path);
5448
5449 location = &BTRFS_I(inode)->location;
5450 location->objectid = objectid;
5451 location->offset = 0;
5452 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
5453
5454 btrfs_inherit_iflags(inode, dir);
5455
5456 if (S_ISREG(mode)) {
5457 if (btrfs_test_opt(root, NODATASUM))
5458 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
5459 if (btrfs_test_opt(root, NODATACOW))
5460 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
5461 BTRFS_INODE_NODATASUM;
5462 }
5463
5464 btrfs_insert_inode_hash(inode);
5465 inode_tree_add(inode);
5466
5467 trace_btrfs_inode_new(inode);
5468 btrfs_set_inode_last_trans(trans, inode);
5469
5470 btrfs_update_root_times(trans, root);
5471
5472 return inode;
5473 fail:
5474 if (dir)
5475 BTRFS_I(dir)->index_cnt--;
5476 btrfs_free_path(path);
5477 iput(inode);
5478 return ERR_PTR(ret);
5479 }
5480
5481 static inline u8 btrfs_inode_type(struct inode *inode)
5482 {
5483 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
5484 }
5485
5486 /*
5487 * utility function to add 'inode' into 'parent_inode' with
5488 * a give name and a given sequence number.
5489 * if 'add_backref' is true, also insert a backref from the
5490 * inode to the parent directory.
5491 */
5492 int btrfs_add_link(struct btrfs_trans_handle *trans,
5493 struct inode *parent_inode, struct inode *inode,
5494 const char *name, int name_len, int add_backref, u64 index)
5495 {
5496 int ret = 0;
5497 struct btrfs_key key;
5498 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
5499 u64 ino = btrfs_ino(inode);
5500 u64 parent_ino = btrfs_ino(parent_inode);
5501
5502 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5503 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
5504 } else {
5505 key.objectid = ino;
5506 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
5507 key.offset = 0;
5508 }
5509
5510 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5511 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
5512 key.objectid, root->root_key.objectid,
5513 parent_ino, index, name, name_len);
5514 } else if (add_backref) {
5515 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
5516 parent_ino, index);
5517 }
5518
5519 /* Nothing to clean up yet */
5520 if (ret)
5521 return ret;
5522
5523 ret = btrfs_insert_dir_item(trans, root, name, name_len,
5524 parent_inode, &key,
5525 btrfs_inode_type(inode), index);
5526 if (ret == -EEXIST || ret == -EOVERFLOW)
5527 goto fail_dir_item;
5528 else if (ret) {
5529 btrfs_abort_transaction(trans, root, ret);
5530 return ret;
5531 }
5532
5533 btrfs_i_size_write(parent_inode, parent_inode->i_size +
5534 name_len * 2);
5535 inode_inc_iversion(parent_inode);
5536 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
5537 ret = btrfs_update_inode(trans, root, parent_inode);
5538 if (ret)
5539 btrfs_abort_transaction(trans, root, ret);
5540 return ret;
5541
5542 fail_dir_item:
5543 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5544 u64 local_index;
5545 int err;
5546 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
5547 key.objectid, root->root_key.objectid,
5548 parent_ino, &local_index, name, name_len);
5549
5550 } else if (add_backref) {
5551 u64 local_index;
5552 int err;
5553
5554 err = btrfs_del_inode_ref(trans, root, name, name_len,
5555 ino, parent_ino, &local_index);
5556 }
5557 return ret;
5558 }
5559
5560 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
5561 struct inode *dir, struct dentry *dentry,
5562 struct inode *inode, int backref, u64 index)
5563 {
5564 int err = btrfs_add_link(trans, dir, inode,
5565 dentry->d_name.name, dentry->d_name.len,
5566 backref, index);
5567 if (err > 0)
5568 err = -EEXIST;
5569 return err;
5570 }
5571
5572 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
5573 umode_t mode, dev_t rdev)
5574 {
5575 struct btrfs_trans_handle *trans;
5576 struct btrfs_root *root = BTRFS_I(dir)->root;
5577 struct inode *inode = NULL;
5578 int err;
5579 int drop_inode = 0;
5580 u64 objectid;
5581 u64 index = 0;
5582
5583 if (!new_valid_dev(rdev))
5584 return -EINVAL;
5585
5586 /*
5587 * 2 for inode item and ref
5588 * 2 for dir items
5589 * 1 for xattr if selinux is on
5590 */
5591 trans = btrfs_start_transaction(root, 5);
5592 if (IS_ERR(trans))
5593 return PTR_ERR(trans);
5594
5595 err = btrfs_find_free_ino(root, &objectid);
5596 if (err)
5597 goto out_unlock;
5598
5599 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5600 dentry->d_name.len, btrfs_ino(dir), objectid,
5601 mode, &index);
5602 if (IS_ERR(inode)) {
5603 err = PTR_ERR(inode);
5604 goto out_unlock;
5605 }
5606
5607 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5608 if (err) {
5609 drop_inode = 1;
5610 goto out_unlock;
5611 }
5612
5613 /*
5614 * If the active LSM wants to access the inode during
5615 * d_instantiate it needs these. Smack checks to see
5616 * if the filesystem supports xattrs by looking at the
5617 * ops vector.
5618 */
5619
5620 inode->i_op = &btrfs_special_inode_operations;
5621 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5622 if (err)
5623 drop_inode = 1;
5624 else {
5625 init_special_inode(inode, inode->i_mode, rdev);
5626 btrfs_update_inode(trans, root, inode);
5627 d_instantiate(dentry, inode);
5628 }
5629 out_unlock:
5630 btrfs_end_transaction(trans, root);
5631 btrfs_btree_balance_dirty(root);
5632 if (drop_inode) {
5633 inode_dec_link_count(inode);
5634 iput(inode);
5635 }
5636 return err;
5637 }
5638
5639 static int btrfs_create(struct inode *dir, struct dentry *dentry,
5640 umode_t mode, bool excl)
5641 {
5642 struct btrfs_trans_handle *trans;
5643 struct btrfs_root *root = BTRFS_I(dir)->root;
5644 struct inode *inode = NULL;
5645 int drop_inode_on_err = 0;
5646 int err;
5647 u64 objectid;
5648 u64 index = 0;
5649
5650 /*
5651 * 2 for inode item and ref
5652 * 2 for dir items
5653 * 1 for xattr if selinux is on
5654 */
5655 trans = btrfs_start_transaction(root, 5);
5656 if (IS_ERR(trans))
5657 return PTR_ERR(trans);
5658
5659 err = btrfs_find_free_ino(root, &objectid);
5660 if (err)
5661 goto out_unlock;
5662
5663 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5664 dentry->d_name.len, btrfs_ino(dir), objectid,
5665 mode, &index);
5666 if (IS_ERR(inode)) {
5667 err = PTR_ERR(inode);
5668 goto out_unlock;
5669 }
5670 drop_inode_on_err = 1;
5671
5672 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5673 if (err)
5674 goto out_unlock;
5675
5676 err = btrfs_update_inode(trans, root, inode);
5677 if (err)
5678 goto out_unlock;
5679
5680 /*
5681 * If the active LSM wants to access the inode during
5682 * d_instantiate it needs these. Smack checks to see
5683 * if the filesystem supports xattrs by looking at the
5684 * ops vector.
5685 */
5686 inode->i_fop = &btrfs_file_operations;
5687 inode->i_op = &btrfs_file_inode_operations;
5688
5689 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5690 if (err)
5691 goto out_unlock;
5692
5693 inode->i_mapping->a_ops = &btrfs_aops;
5694 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
5695 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
5696 d_instantiate(dentry, inode);
5697
5698 out_unlock:
5699 btrfs_end_transaction(trans, root);
5700 if (err && drop_inode_on_err) {
5701 inode_dec_link_count(inode);
5702 iput(inode);
5703 }
5704 btrfs_btree_balance_dirty(root);
5705 return err;
5706 }
5707
5708 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
5709 struct dentry *dentry)
5710 {
5711 struct btrfs_trans_handle *trans;
5712 struct btrfs_root *root = BTRFS_I(dir)->root;
5713 struct inode *inode = old_dentry->d_inode;
5714 u64 index;
5715 int err;
5716 int drop_inode = 0;
5717
5718 /* do not allow sys_link's with other subvols of the same device */
5719 if (root->objectid != BTRFS_I(inode)->root->objectid)
5720 return -EXDEV;
5721
5722 if (inode->i_nlink >= BTRFS_LINK_MAX)
5723 return -EMLINK;
5724
5725 err = btrfs_set_inode_index(dir, &index);
5726 if (err)
5727 goto fail;
5728
5729 /*
5730 * 2 items for inode and inode ref
5731 * 2 items for dir items
5732 * 1 item for parent inode
5733 */
5734 trans = btrfs_start_transaction(root, 5);
5735 if (IS_ERR(trans)) {
5736 err = PTR_ERR(trans);
5737 goto fail;
5738 }
5739
5740 inc_nlink(inode);
5741 inode_inc_iversion(inode);
5742 inode->i_ctime = CURRENT_TIME;
5743 ihold(inode);
5744 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
5745
5746 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
5747
5748 if (err) {
5749 drop_inode = 1;
5750 } else {
5751 struct dentry *parent = dentry->d_parent;
5752 err = btrfs_update_inode(trans, root, inode);
5753 if (err)
5754 goto fail;
5755 d_instantiate(dentry, inode);
5756 btrfs_log_new_name(trans, inode, NULL, parent);
5757 }
5758
5759 btrfs_end_transaction(trans, root);
5760 fail:
5761 if (drop_inode) {
5762 inode_dec_link_count(inode);
5763 iput(inode);
5764 }
5765 btrfs_btree_balance_dirty(root);
5766 return err;
5767 }
5768
5769 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
5770 {
5771 struct inode *inode = NULL;
5772 struct btrfs_trans_handle *trans;
5773 struct btrfs_root *root = BTRFS_I(dir)->root;
5774 int err = 0;
5775 int drop_on_err = 0;
5776 u64 objectid = 0;
5777 u64 index = 0;
5778
5779 /*
5780 * 2 items for inode and ref
5781 * 2 items for dir items
5782 * 1 for xattr if selinux is on
5783 */
5784 trans = btrfs_start_transaction(root, 5);
5785 if (IS_ERR(trans))
5786 return PTR_ERR(trans);
5787
5788 err = btrfs_find_free_ino(root, &objectid);
5789 if (err)
5790 goto out_fail;
5791
5792 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5793 dentry->d_name.len, btrfs_ino(dir), objectid,
5794 S_IFDIR | mode, &index);
5795 if (IS_ERR(inode)) {
5796 err = PTR_ERR(inode);
5797 goto out_fail;
5798 }
5799
5800 drop_on_err = 1;
5801
5802 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5803 if (err)
5804 goto out_fail;
5805
5806 inode->i_op = &btrfs_dir_inode_operations;
5807 inode->i_fop = &btrfs_dir_file_operations;
5808
5809 btrfs_i_size_write(inode, 0);
5810 err = btrfs_update_inode(trans, root, inode);
5811 if (err)
5812 goto out_fail;
5813
5814 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
5815 dentry->d_name.len, 0, index);
5816 if (err)
5817 goto out_fail;
5818
5819 d_instantiate(dentry, inode);
5820 drop_on_err = 0;
5821
5822 out_fail:
5823 btrfs_end_transaction(trans, root);
5824 if (drop_on_err)
5825 iput(inode);
5826 btrfs_btree_balance_dirty(root);
5827 return err;
5828 }
5829
5830 /* helper for btfs_get_extent. Given an existing extent in the tree,
5831 * and an extent that you want to insert, deal with overlap and insert
5832 * the new extent into the tree.
5833 */
5834 static int merge_extent_mapping(struct extent_map_tree *em_tree,
5835 struct extent_map *existing,
5836 struct extent_map *em,
5837 u64 map_start, u64 map_len)
5838 {
5839 u64 start_diff;
5840
5841 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
5842 start_diff = map_start - em->start;
5843 em->start = map_start;
5844 em->len = map_len;
5845 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
5846 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
5847 em->block_start += start_diff;
5848 em->block_len -= start_diff;
5849 }
5850 return add_extent_mapping(em_tree, em, 0);
5851 }
5852
5853 static noinline int uncompress_inline(struct btrfs_path *path,
5854 struct inode *inode, struct page *page,
5855 size_t pg_offset, u64 extent_offset,
5856 struct btrfs_file_extent_item *item)
5857 {
5858 int ret;
5859 struct extent_buffer *leaf = path->nodes[0];
5860 char *tmp;
5861 size_t max_size;
5862 unsigned long inline_size;
5863 unsigned long ptr;
5864 int compress_type;
5865
5866 WARN_ON(pg_offset != 0);
5867 compress_type = btrfs_file_extent_compression(leaf, item);
5868 max_size = btrfs_file_extent_ram_bytes(leaf, item);
5869 inline_size = btrfs_file_extent_inline_item_len(leaf,
5870 btrfs_item_nr(path->slots[0]));
5871 tmp = kmalloc(inline_size, GFP_NOFS);
5872 if (!tmp)
5873 return -ENOMEM;
5874 ptr = btrfs_file_extent_inline_start(item);
5875
5876 read_extent_buffer(leaf, tmp, ptr, inline_size);
5877
5878 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
5879 ret = btrfs_decompress(compress_type, tmp, page,
5880 extent_offset, inline_size, max_size);
5881 if (ret) {
5882 char *kaddr = kmap_atomic(page);
5883 unsigned long copy_size = min_t(u64,
5884 PAGE_CACHE_SIZE - pg_offset,
5885 max_size - extent_offset);
5886 memset(kaddr + pg_offset, 0, copy_size);
5887 kunmap_atomic(kaddr);
5888 }
5889 kfree(tmp);
5890 return 0;
5891 }
5892
5893 /*
5894 * a bit scary, this does extent mapping from logical file offset to the disk.
5895 * the ugly parts come from merging extents from the disk with the in-ram
5896 * representation. This gets more complex because of the data=ordered code,
5897 * where the in-ram extents might be locked pending data=ordered completion.
5898 *
5899 * This also copies inline extents directly into the page.
5900 */
5901
5902 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
5903 size_t pg_offset, u64 start, u64 len,
5904 int create)
5905 {
5906 int ret;
5907 int err = 0;
5908 u64 bytenr;
5909 u64 extent_start = 0;
5910 u64 extent_end = 0;
5911 u64 objectid = btrfs_ino(inode);
5912 u32 found_type;
5913 struct btrfs_path *path = NULL;
5914 struct btrfs_root *root = BTRFS_I(inode)->root;
5915 struct btrfs_file_extent_item *item;
5916 struct extent_buffer *leaf;
5917 struct btrfs_key found_key;
5918 struct extent_map *em = NULL;
5919 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
5920 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5921 struct btrfs_trans_handle *trans = NULL;
5922 int compress_type;
5923
5924 again:
5925 read_lock(&em_tree->lock);
5926 em = lookup_extent_mapping(em_tree, start, len);
5927 if (em)
5928 em->bdev = root->fs_info->fs_devices->latest_bdev;
5929 read_unlock(&em_tree->lock);
5930
5931 if (em) {
5932 if (em->start > start || em->start + em->len <= start)
5933 free_extent_map(em);
5934 else if (em->block_start == EXTENT_MAP_INLINE && page)
5935 free_extent_map(em);
5936 else
5937 goto out;
5938 }
5939 em = alloc_extent_map();
5940 if (!em) {
5941 err = -ENOMEM;
5942 goto out;
5943 }
5944 em->bdev = root->fs_info->fs_devices->latest_bdev;
5945 em->start = EXTENT_MAP_HOLE;
5946 em->orig_start = EXTENT_MAP_HOLE;
5947 em->len = (u64)-1;
5948 em->block_len = (u64)-1;
5949
5950 if (!path) {
5951 path = btrfs_alloc_path();
5952 if (!path) {
5953 err = -ENOMEM;
5954 goto out;
5955 }
5956 /*
5957 * Chances are we'll be called again, so go ahead and do
5958 * readahead
5959 */
5960 path->reada = 1;
5961 }
5962
5963 ret = btrfs_lookup_file_extent(trans, root, path,
5964 objectid, start, trans != NULL);
5965 if (ret < 0) {
5966 err = ret;
5967 goto out;
5968 }
5969
5970 if (ret != 0) {
5971 if (path->slots[0] == 0)
5972 goto not_found;
5973 path->slots[0]--;
5974 }
5975
5976 leaf = path->nodes[0];
5977 item = btrfs_item_ptr(leaf, path->slots[0],
5978 struct btrfs_file_extent_item);
5979 /* are we inside the extent that was found? */
5980 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5981 found_type = btrfs_key_type(&found_key);
5982 if (found_key.objectid != objectid ||
5983 found_type != BTRFS_EXTENT_DATA_KEY) {
5984 /*
5985 * If we backup past the first extent we want to move forward
5986 * and see if there is an extent in front of us, otherwise we'll
5987 * say there is a hole for our whole search range which can
5988 * cause problems.
5989 */
5990 extent_end = start;
5991 goto next;
5992 }
5993
5994 found_type = btrfs_file_extent_type(leaf, item);
5995 extent_start = found_key.offset;
5996 compress_type = btrfs_file_extent_compression(leaf, item);
5997 if (found_type == BTRFS_FILE_EXTENT_REG ||
5998 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
5999 extent_end = extent_start +
6000 btrfs_file_extent_num_bytes(leaf, item);
6001 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6002 size_t size;
6003 size = btrfs_file_extent_inline_len(leaf, item);
6004 extent_end = ALIGN(extent_start + size, root->sectorsize);
6005 }
6006 next:
6007 if (start >= extent_end) {
6008 path->slots[0]++;
6009 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6010 ret = btrfs_next_leaf(root, path);
6011 if (ret < 0) {
6012 err = ret;
6013 goto out;
6014 }
6015 if (ret > 0)
6016 goto not_found;
6017 leaf = path->nodes[0];
6018 }
6019 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6020 if (found_key.objectid != objectid ||
6021 found_key.type != BTRFS_EXTENT_DATA_KEY)
6022 goto not_found;
6023 if (start + len <= found_key.offset)
6024 goto not_found;
6025 em->start = start;
6026 em->orig_start = start;
6027 em->len = found_key.offset - start;
6028 goto not_found_em;
6029 }
6030
6031 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, item);
6032 if (found_type == BTRFS_FILE_EXTENT_REG ||
6033 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6034 em->start = extent_start;
6035 em->len = extent_end - extent_start;
6036 em->orig_start = extent_start -
6037 btrfs_file_extent_offset(leaf, item);
6038 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf,
6039 item);
6040 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
6041 if (bytenr == 0) {
6042 em->block_start = EXTENT_MAP_HOLE;
6043 goto insert;
6044 }
6045 if (compress_type != BTRFS_COMPRESS_NONE) {
6046 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
6047 em->compress_type = compress_type;
6048 em->block_start = bytenr;
6049 em->block_len = em->orig_block_len;
6050 } else {
6051 bytenr += btrfs_file_extent_offset(leaf, item);
6052 em->block_start = bytenr;
6053 em->block_len = em->len;
6054 if (found_type == BTRFS_FILE_EXTENT_PREALLOC)
6055 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
6056 }
6057 goto insert;
6058 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6059 unsigned long ptr;
6060 char *map;
6061 size_t size;
6062 size_t extent_offset;
6063 size_t copy_size;
6064
6065 em->block_start = EXTENT_MAP_INLINE;
6066 if (!page || create) {
6067 em->start = extent_start;
6068 em->len = extent_end - extent_start;
6069 goto out;
6070 }
6071
6072 size = btrfs_file_extent_inline_len(leaf, item);
6073 extent_offset = page_offset(page) + pg_offset - extent_start;
6074 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
6075 size - extent_offset);
6076 em->start = extent_start + extent_offset;
6077 em->len = ALIGN(copy_size, root->sectorsize);
6078 em->orig_block_len = em->len;
6079 em->orig_start = em->start;
6080 if (compress_type) {
6081 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
6082 em->compress_type = compress_type;
6083 }
6084 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6085 if (create == 0 && !PageUptodate(page)) {
6086 if (btrfs_file_extent_compression(leaf, item) !=
6087 BTRFS_COMPRESS_NONE) {
6088 ret = uncompress_inline(path, inode, page,
6089 pg_offset,
6090 extent_offset, item);
6091 BUG_ON(ret); /* -ENOMEM */
6092 } else {
6093 map = kmap(page);
6094 read_extent_buffer(leaf, map + pg_offset, ptr,
6095 copy_size);
6096 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
6097 memset(map + pg_offset + copy_size, 0,
6098 PAGE_CACHE_SIZE - pg_offset -
6099 copy_size);
6100 }
6101 kunmap(page);
6102 }
6103 flush_dcache_page(page);
6104 } else if (create && PageUptodate(page)) {
6105 BUG();
6106 if (!trans) {
6107 kunmap(page);
6108 free_extent_map(em);
6109 em = NULL;
6110
6111 btrfs_release_path(path);
6112 trans = btrfs_join_transaction(root);
6113
6114 if (IS_ERR(trans))
6115 return ERR_CAST(trans);
6116 goto again;
6117 }
6118 map = kmap(page);
6119 write_extent_buffer(leaf, map + pg_offset, ptr,
6120 copy_size);
6121 kunmap(page);
6122 btrfs_mark_buffer_dirty(leaf);
6123 }
6124 set_extent_uptodate(io_tree, em->start,
6125 extent_map_end(em) - 1, NULL, GFP_NOFS);
6126 goto insert;
6127 } else {
6128 WARN(1, KERN_ERR "btrfs unknown found_type %d\n", found_type);
6129 }
6130 not_found:
6131 em->start = start;
6132 em->orig_start = start;
6133 em->len = len;
6134 not_found_em:
6135 em->block_start = EXTENT_MAP_HOLE;
6136 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
6137 insert:
6138 btrfs_release_path(path);
6139 if (em->start > start || extent_map_end(em) <= start) {
6140 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
6141 em->start, em->len, start, len);
6142 err = -EIO;
6143 goto out;
6144 }
6145
6146 err = 0;
6147 write_lock(&em_tree->lock);
6148 ret = add_extent_mapping(em_tree, em, 0);
6149 /* it is possible that someone inserted the extent into the tree
6150 * while we had the lock dropped. It is also possible that
6151 * an overlapping map exists in the tree
6152 */
6153 if (ret == -EEXIST) {
6154 struct extent_map *existing;
6155
6156 ret = 0;
6157
6158 existing = lookup_extent_mapping(em_tree, start, len);
6159 if (existing && (existing->start > start ||
6160 existing->start + existing->len <= start)) {
6161 free_extent_map(existing);
6162 existing = NULL;
6163 }
6164 if (!existing) {
6165 existing = lookup_extent_mapping(em_tree, em->start,
6166 em->len);
6167 if (existing) {
6168 err = merge_extent_mapping(em_tree, existing,
6169 em, start,
6170 root->sectorsize);
6171 free_extent_map(existing);
6172 if (err) {
6173 free_extent_map(em);
6174 em = NULL;
6175 }
6176 } else {
6177 err = -EIO;
6178 free_extent_map(em);
6179 em = NULL;
6180 }
6181 } else {
6182 free_extent_map(em);
6183 em = existing;
6184 err = 0;
6185 }
6186 }
6187 write_unlock(&em_tree->lock);
6188 out:
6189
6190 trace_btrfs_get_extent(root, em);
6191
6192 if (path)
6193 btrfs_free_path(path);
6194 if (trans) {
6195 ret = btrfs_end_transaction(trans, root);
6196 if (!err)
6197 err = ret;
6198 }
6199 if (err) {
6200 free_extent_map(em);
6201 return ERR_PTR(err);
6202 }
6203 BUG_ON(!em); /* Error is always set */
6204 return em;
6205 }
6206
6207 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
6208 size_t pg_offset, u64 start, u64 len,
6209 int create)
6210 {
6211 struct extent_map *em;
6212 struct extent_map *hole_em = NULL;
6213 u64 range_start = start;
6214 u64 end;
6215 u64 found;
6216 u64 found_end;
6217 int err = 0;
6218
6219 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
6220 if (IS_ERR(em))
6221 return em;
6222 if (em) {
6223 /*
6224 * if our em maps to
6225 * - a hole or
6226 * - a pre-alloc extent,
6227 * there might actually be delalloc bytes behind it.
6228 */
6229 if (em->block_start != EXTENT_MAP_HOLE &&
6230 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6231 return em;
6232 else
6233 hole_em = em;
6234 }
6235
6236 /* check to see if we've wrapped (len == -1 or similar) */
6237 end = start + len;
6238 if (end < start)
6239 end = (u64)-1;
6240 else
6241 end -= 1;
6242
6243 em = NULL;
6244
6245 /* ok, we didn't find anything, lets look for delalloc */
6246 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
6247 end, len, EXTENT_DELALLOC, 1);
6248 found_end = range_start + found;
6249 if (found_end < range_start)
6250 found_end = (u64)-1;
6251
6252 /*
6253 * we didn't find anything useful, return
6254 * the original results from get_extent()
6255 */
6256 if (range_start > end || found_end <= start) {
6257 em = hole_em;
6258 hole_em = NULL;
6259 goto out;
6260 }
6261
6262 /* adjust the range_start to make sure it doesn't
6263 * go backwards from the start they passed in
6264 */
6265 range_start = max(start, range_start);
6266 found = found_end - range_start;
6267
6268 if (found > 0) {
6269 u64 hole_start = start;
6270 u64 hole_len = len;
6271
6272 em = alloc_extent_map();
6273 if (!em) {
6274 err = -ENOMEM;
6275 goto out;
6276 }
6277 /*
6278 * when btrfs_get_extent can't find anything it
6279 * returns one huge hole
6280 *
6281 * make sure what it found really fits our range, and
6282 * adjust to make sure it is based on the start from
6283 * the caller
6284 */
6285 if (hole_em) {
6286 u64 calc_end = extent_map_end(hole_em);
6287
6288 if (calc_end <= start || (hole_em->start > end)) {
6289 free_extent_map(hole_em);
6290 hole_em = NULL;
6291 } else {
6292 hole_start = max(hole_em->start, start);
6293 hole_len = calc_end - hole_start;
6294 }
6295 }
6296 em->bdev = NULL;
6297 if (hole_em && range_start > hole_start) {
6298 /* our hole starts before our delalloc, so we
6299 * have to return just the parts of the hole
6300 * that go until the delalloc starts
6301 */
6302 em->len = min(hole_len,
6303 range_start - hole_start);
6304 em->start = hole_start;
6305 em->orig_start = hole_start;
6306 /*
6307 * don't adjust block start at all,
6308 * it is fixed at EXTENT_MAP_HOLE
6309 */
6310 em->block_start = hole_em->block_start;
6311 em->block_len = hole_len;
6312 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
6313 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
6314 } else {
6315 em->start = range_start;
6316 em->len = found;
6317 em->orig_start = range_start;
6318 em->block_start = EXTENT_MAP_DELALLOC;
6319 em->block_len = found;
6320 }
6321 } else if (hole_em) {
6322 return hole_em;
6323 }
6324 out:
6325
6326 free_extent_map(hole_em);
6327 if (err) {
6328 free_extent_map(em);
6329 return ERR_PTR(err);
6330 }
6331 return em;
6332 }
6333
6334 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
6335 u64 start, u64 len)
6336 {
6337 struct btrfs_root *root = BTRFS_I(inode)->root;
6338 struct extent_map *em;
6339 struct btrfs_key ins;
6340 u64 alloc_hint;
6341 int ret;
6342
6343 alloc_hint = get_extent_allocation_hint(inode, start, len);
6344 ret = btrfs_reserve_extent(root, len, root->sectorsize, 0,
6345 alloc_hint, &ins, 1);
6346 if (ret)
6347 return ERR_PTR(ret);
6348
6349 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
6350 ins.offset, ins.offset, ins.offset, 0);
6351 if (IS_ERR(em)) {
6352 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
6353 return em;
6354 }
6355
6356 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
6357 ins.offset, ins.offset, 0);
6358 if (ret) {
6359 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
6360 free_extent_map(em);
6361 return ERR_PTR(ret);
6362 }
6363
6364 return em;
6365 }
6366
6367 /*
6368 * returns 1 when the nocow is safe, < 1 on error, 0 if the
6369 * block must be cow'd
6370 */
6371 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
6372 u64 *orig_start, u64 *orig_block_len,
6373 u64 *ram_bytes)
6374 {
6375 struct btrfs_trans_handle *trans;
6376 struct btrfs_path *path;
6377 int ret;
6378 struct extent_buffer *leaf;
6379 struct btrfs_root *root = BTRFS_I(inode)->root;
6380 struct btrfs_file_extent_item *fi;
6381 struct btrfs_key key;
6382 u64 disk_bytenr;
6383 u64 backref_offset;
6384 u64 extent_end;
6385 u64 num_bytes;
6386 int slot;
6387 int found_type;
6388 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
6389 path = btrfs_alloc_path();
6390 if (!path)
6391 return -ENOMEM;
6392
6393 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
6394 offset, 0);
6395 if (ret < 0)
6396 goto out;
6397
6398 slot = path->slots[0];
6399 if (ret == 1) {
6400 if (slot == 0) {
6401 /* can't find the item, must cow */
6402 ret = 0;
6403 goto out;
6404 }
6405 slot--;
6406 }
6407 ret = 0;
6408 leaf = path->nodes[0];
6409 btrfs_item_key_to_cpu(leaf, &key, slot);
6410 if (key.objectid != btrfs_ino(inode) ||
6411 key.type != BTRFS_EXTENT_DATA_KEY) {
6412 /* not our file or wrong item type, must cow */
6413 goto out;
6414 }
6415
6416 if (key.offset > offset) {
6417 /* Wrong offset, must cow */
6418 goto out;
6419 }
6420
6421 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
6422 found_type = btrfs_file_extent_type(leaf, fi);
6423 if (found_type != BTRFS_FILE_EXTENT_REG &&
6424 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
6425 /* not a regular extent, must cow */
6426 goto out;
6427 }
6428
6429 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
6430 goto out;
6431
6432 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
6433 if (disk_bytenr == 0)
6434 goto out;
6435
6436 if (btrfs_file_extent_compression(leaf, fi) ||
6437 btrfs_file_extent_encryption(leaf, fi) ||
6438 btrfs_file_extent_other_encoding(leaf, fi))
6439 goto out;
6440
6441 backref_offset = btrfs_file_extent_offset(leaf, fi);
6442
6443 if (orig_start) {
6444 *orig_start = key.offset - backref_offset;
6445 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
6446 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
6447 }
6448
6449 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
6450
6451 if (btrfs_extent_readonly(root, disk_bytenr))
6452 goto out;
6453 btrfs_release_path(path);
6454
6455 /*
6456 * look for other files referencing this extent, if we
6457 * find any we must cow
6458 */
6459 trans = btrfs_join_transaction(root);
6460 if (IS_ERR(trans)) {
6461 ret = 0;
6462 goto out;
6463 }
6464
6465 ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
6466 key.offset - backref_offset, disk_bytenr);
6467 btrfs_end_transaction(trans, root);
6468 if (ret) {
6469 ret = 0;
6470 goto out;
6471 }
6472
6473 /*
6474 * adjust disk_bytenr and num_bytes to cover just the bytes
6475 * in this extent we are about to write. If there
6476 * are any csums in that range we have to cow in order
6477 * to keep the csums correct
6478 */
6479 disk_bytenr += backref_offset;
6480 disk_bytenr += offset - key.offset;
6481 num_bytes = min(offset + *len, extent_end) - offset;
6482 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
6483 goto out;
6484 /*
6485 * all of the above have passed, it is safe to overwrite this extent
6486 * without cow
6487 */
6488 *len = num_bytes;
6489 ret = 1;
6490 out:
6491 btrfs_free_path(path);
6492 return ret;
6493 }
6494
6495 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
6496 struct extent_state **cached_state, int writing)
6497 {
6498 struct btrfs_ordered_extent *ordered;
6499 int ret = 0;
6500
6501 while (1) {
6502 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6503 0, cached_state);
6504 /*
6505 * We're concerned with the entire range that we're going to be
6506 * doing DIO to, so we need to make sure theres no ordered
6507 * extents in this range.
6508 */
6509 ordered = btrfs_lookup_ordered_range(inode, lockstart,
6510 lockend - lockstart + 1);
6511
6512 /*
6513 * We need to make sure there are no buffered pages in this
6514 * range either, we could have raced between the invalidate in
6515 * generic_file_direct_write and locking the extent. The
6516 * invalidate needs to happen so that reads after a write do not
6517 * get stale data.
6518 */
6519 if (!ordered && (!writing ||
6520 !test_range_bit(&BTRFS_I(inode)->io_tree,
6521 lockstart, lockend, EXTENT_UPTODATE, 0,
6522 *cached_state)))
6523 break;
6524
6525 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6526 cached_state, GFP_NOFS);
6527
6528 if (ordered) {
6529 btrfs_start_ordered_extent(inode, ordered, 1);
6530 btrfs_put_ordered_extent(ordered);
6531 } else {
6532 /* Screw you mmap */
6533 ret = filemap_write_and_wait_range(inode->i_mapping,
6534 lockstart,
6535 lockend);
6536 if (ret)
6537 break;
6538
6539 /*
6540 * If we found a page that couldn't be invalidated just
6541 * fall back to buffered.
6542 */
6543 ret = invalidate_inode_pages2_range(inode->i_mapping,
6544 lockstart >> PAGE_CACHE_SHIFT,
6545 lockend >> PAGE_CACHE_SHIFT);
6546 if (ret)
6547 break;
6548 }
6549
6550 cond_resched();
6551 }
6552
6553 return ret;
6554 }
6555
6556 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
6557 u64 len, u64 orig_start,
6558 u64 block_start, u64 block_len,
6559 u64 orig_block_len, u64 ram_bytes,
6560 int type)
6561 {
6562 struct extent_map_tree *em_tree;
6563 struct extent_map *em;
6564 struct btrfs_root *root = BTRFS_I(inode)->root;
6565 int ret;
6566
6567 em_tree = &BTRFS_I(inode)->extent_tree;
6568 em = alloc_extent_map();
6569 if (!em)
6570 return ERR_PTR(-ENOMEM);
6571
6572 em->start = start;
6573 em->orig_start = orig_start;
6574 em->mod_start = start;
6575 em->mod_len = len;
6576 em->len = len;
6577 em->block_len = block_len;
6578 em->block_start = block_start;
6579 em->bdev = root->fs_info->fs_devices->latest_bdev;
6580 em->orig_block_len = orig_block_len;
6581 em->ram_bytes = ram_bytes;
6582 em->generation = -1;
6583 set_bit(EXTENT_FLAG_PINNED, &em->flags);
6584 if (type == BTRFS_ORDERED_PREALLOC)
6585 set_bit(EXTENT_FLAG_FILLING, &em->flags);
6586
6587 do {
6588 btrfs_drop_extent_cache(inode, em->start,
6589 em->start + em->len - 1, 0);
6590 write_lock(&em_tree->lock);
6591 ret = add_extent_mapping(em_tree, em, 1);
6592 write_unlock(&em_tree->lock);
6593 } while (ret == -EEXIST);
6594
6595 if (ret) {
6596 free_extent_map(em);
6597 return ERR_PTR(ret);
6598 }
6599
6600 return em;
6601 }
6602
6603
6604 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
6605 struct buffer_head *bh_result, int create)
6606 {
6607 struct extent_map *em;
6608 struct btrfs_root *root = BTRFS_I(inode)->root;
6609 struct extent_state *cached_state = NULL;
6610 u64 start = iblock << inode->i_blkbits;
6611 u64 lockstart, lockend;
6612 u64 len = bh_result->b_size;
6613 int unlock_bits = EXTENT_LOCKED;
6614 int ret = 0;
6615
6616 if (create)
6617 unlock_bits |= EXTENT_DELALLOC | EXTENT_DIRTY;
6618 else
6619 len = min_t(u64, len, root->sectorsize);
6620
6621 lockstart = start;
6622 lockend = start + len - 1;
6623
6624 /*
6625 * If this errors out it's because we couldn't invalidate pagecache for
6626 * this range and we need to fallback to buffered.
6627 */
6628 if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create))
6629 return -ENOTBLK;
6630
6631 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
6632 if (IS_ERR(em)) {
6633 ret = PTR_ERR(em);
6634 goto unlock_err;
6635 }
6636
6637 /*
6638 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
6639 * io. INLINE is special, and we could probably kludge it in here, but
6640 * it's still buffered so for safety lets just fall back to the generic
6641 * buffered path.
6642 *
6643 * For COMPRESSED we _have_ to read the entire extent in so we can
6644 * decompress it, so there will be buffering required no matter what we
6645 * do, so go ahead and fallback to buffered.
6646 *
6647 * We return -ENOTBLK because thats what makes DIO go ahead and go back
6648 * to buffered IO. Don't blame me, this is the price we pay for using
6649 * the generic code.
6650 */
6651 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
6652 em->block_start == EXTENT_MAP_INLINE) {
6653 free_extent_map(em);
6654 ret = -ENOTBLK;
6655 goto unlock_err;
6656 }
6657
6658 /* Just a good old fashioned hole, return */
6659 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
6660 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
6661 free_extent_map(em);
6662 goto unlock_err;
6663 }
6664
6665 /*
6666 * We don't allocate a new extent in the following cases
6667 *
6668 * 1) The inode is marked as NODATACOW. In this case we'll just use the
6669 * existing extent.
6670 * 2) The extent is marked as PREALLOC. We're good to go here and can
6671 * just use the extent.
6672 *
6673 */
6674 if (!create) {
6675 len = min(len, em->len - (start - em->start));
6676 lockstart = start + len;
6677 goto unlock;
6678 }
6679
6680 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
6681 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
6682 em->block_start != EXTENT_MAP_HOLE)) {
6683 int type;
6684 int ret;
6685 u64 block_start, orig_start, orig_block_len, ram_bytes;
6686
6687 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6688 type = BTRFS_ORDERED_PREALLOC;
6689 else
6690 type = BTRFS_ORDERED_NOCOW;
6691 len = min(len, em->len - (start - em->start));
6692 block_start = em->block_start + (start - em->start);
6693
6694 if (can_nocow_extent(inode, start, &len, &orig_start,
6695 &orig_block_len, &ram_bytes) == 1) {
6696 if (type == BTRFS_ORDERED_PREALLOC) {
6697 free_extent_map(em);
6698 em = create_pinned_em(inode, start, len,
6699 orig_start,
6700 block_start, len,
6701 orig_block_len,
6702 ram_bytes, type);
6703 if (IS_ERR(em))
6704 goto unlock_err;
6705 }
6706
6707 ret = btrfs_add_ordered_extent_dio(inode, start,
6708 block_start, len, len, type);
6709 if (ret) {
6710 free_extent_map(em);
6711 goto unlock_err;
6712 }
6713 goto unlock;
6714 }
6715 }
6716
6717 /*
6718 * this will cow the extent, reset the len in case we changed
6719 * it above
6720 */
6721 len = bh_result->b_size;
6722 free_extent_map(em);
6723 em = btrfs_new_extent_direct(inode, start, len);
6724 if (IS_ERR(em)) {
6725 ret = PTR_ERR(em);
6726 goto unlock_err;
6727 }
6728 len = min(len, em->len - (start - em->start));
6729 unlock:
6730 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
6731 inode->i_blkbits;
6732 bh_result->b_size = len;
6733 bh_result->b_bdev = em->bdev;
6734 set_buffer_mapped(bh_result);
6735 if (create) {
6736 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6737 set_buffer_new(bh_result);
6738
6739 /*
6740 * Need to update the i_size under the extent lock so buffered
6741 * readers will get the updated i_size when we unlock.
6742 */
6743 if (start + len > i_size_read(inode))
6744 i_size_write(inode, start + len);
6745
6746 spin_lock(&BTRFS_I(inode)->lock);
6747 BTRFS_I(inode)->outstanding_extents++;
6748 spin_unlock(&BTRFS_I(inode)->lock);
6749
6750 ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6751 lockstart + len - 1, EXTENT_DELALLOC, NULL,
6752 &cached_state, GFP_NOFS);
6753 BUG_ON(ret);
6754 }
6755
6756 /*
6757 * In the case of write we need to clear and unlock the entire range,
6758 * in the case of read we need to unlock only the end area that we
6759 * aren't using if there is any left over space.
6760 */
6761 if (lockstart < lockend) {
6762 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6763 lockend, unlock_bits, 1, 0,
6764 &cached_state, GFP_NOFS);
6765 } else {
6766 free_extent_state(cached_state);
6767 }
6768
6769 free_extent_map(em);
6770
6771 return 0;
6772
6773 unlock_err:
6774 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6775 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
6776 return ret;
6777 }
6778
6779 static void btrfs_endio_direct_read(struct bio *bio, int err)
6780 {
6781 struct btrfs_dio_private *dip = bio->bi_private;
6782 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
6783 struct bio_vec *bvec = bio->bi_io_vec;
6784 struct inode *inode = dip->inode;
6785 struct btrfs_root *root = BTRFS_I(inode)->root;
6786 struct bio *dio_bio;
6787 u32 *csums = (u32 *)dip->csum;
6788 int index = 0;
6789 u64 start;
6790
6791 start = dip->logical_offset;
6792 do {
6793 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
6794 struct page *page = bvec->bv_page;
6795 char *kaddr;
6796 u32 csum = ~(u32)0;
6797 unsigned long flags;
6798
6799 local_irq_save(flags);
6800 kaddr = kmap_atomic(page);
6801 csum = btrfs_csum_data(kaddr + bvec->bv_offset,
6802 csum, bvec->bv_len);
6803 btrfs_csum_final(csum, (char *)&csum);
6804 kunmap_atomic(kaddr);
6805 local_irq_restore(flags);
6806
6807 flush_dcache_page(bvec->bv_page);
6808 if (csum != csums[index]) {
6809 btrfs_err(root->fs_info, "csum failed ino %llu off %llu csum %u expected csum %u",
6810 btrfs_ino(inode), start, csum,
6811 csums[index]);
6812 err = -EIO;
6813 }
6814 }
6815
6816 start += bvec->bv_len;
6817 bvec++;
6818 index++;
6819 } while (bvec <= bvec_end);
6820
6821 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
6822 dip->logical_offset + dip->bytes - 1);
6823 dio_bio = dip->dio_bio;
6824
6825 kfree(dip);
6826
6827 /* If we had a csum failure make sure to clear the uptodate flag */
6828 if (err)
6829 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags);
6830 dio_end_io(dio_bio, err);
6831 bio_put(bio);
6832 }
6833
6834 static void btrfs_endio_direct_write(struct bio *bio, int err)
6835 {
6836 struct btrfs_dio_private *dip = bio->bi_private;
6837 struct inode *inode = dip->inode;
6838 struct btrfs_root *root = BTRFS_I(inode)->root;
6839 struct btrfs_ordered_extent *ordered = NULL;
6840 u64 ordered_offset = dip->logical_offset;
6841 u64 ordered_bytes = dip->bytes;
6842 struct bio *dio_bio;
6843 int ret;
6844
6845 if (err)
6846 goto out_done;
6847 again:
6848 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
6849 &ordered_offset,
6850 ordered_bytes, !err);
6851 if (!ret)
6852 goto out_test;
6853
6854 ordered->work.func = finish_ordered_fn;
6855 ordered->work.flags = 0;
6856 btrfs_queue_worker(&root->fs_info->endio_write_workers,
6857 &ordered->work);
6858 out_test:
6859 /*
6860 * our bio might span multiple ordered extents. If we haven't
6861 * completed the accounting for the whole dio, go back and try again
6862 */
6863 if (ordered_offset < dip->logical_offset + dip->bytes) {
6864 ordered_bytes = dip->logical_offset + dip->bytes -
6865 ordered_offset;
6866 ordered = NULL;
6867 goto again;
6868 }
6869 out_done:
6870 dio_bio = dip->dio_bio;
6871
6872 kfree(dip);
6873
6874 /* If we had an error make sure to clear the uptodate flag */
6875 if (err)
6876 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags);
6877 dio_end_io(dio_bio, err);
6878 bio_put(bio);
6879 }
6880
6881 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
6882 struct bio *bio, int mirror_num,
6883 unsigned long bio_flags, u64 offset)
6884 {
6885 int ret;
6886 struct btrfs_root *root = BTRFS_I(inode)->root;
6887 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
6888 BUG_ON(ret); /* -ENOMEM */
6889 return 0;
6890 }
6891
6892 static void btrfs_end_dio_bio(struct bio *bio, int err)
6893 {
6894 struct btrfs_dio_private *dip = bio->bi_private;
6895
6896 if (err) {
6897 printk(KERN_ERR "btrfs direct IO failed ino %llu rw %lu "
6898 "sector %#Lx len %u err no %d\n",
6899 btrfs_ino(dip->inode), bio->bi_rw,
6900 (unsigned long long)bio->bi_sector, bio->bi_size, err);
6901 dip->errors = 1;
6902
6903 /*
6904 * before atomic variable goto zero, we must make sure
6905 * dip->errors is perceived to be set.
6906 */
6907 smp_mb__before_atomic_dec();
6908 }
6909
6910 /* if there are more bios still pending for this dio, just exit */
6911 if (!atomic_dec_and_test(&dip->pending_bios))
6912 goto out;
6913
6914 if (dip->errors) {
6915 bio_io_error(dip->orig_bio);
6916 } else {
6917 set_bit(BIO_UPTODATE, &dip->dio_bio->bi_flags);
6918 bio_endio(dip->orig_bio, 0);
6919 }
6920 out:
6921 bio_put(bio);
6922 }
6923
6924 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
6925 u64 first_sector, gfp_t gfp_flags)
6926 {
6927 int nr_vecs = bio_get_nr_vecs(bdev);
6928 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
6929 }
6930
6931 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
6932 int rw, u64 file_offset, int skip_sum,
6933 int async_submit)
6934 {
6935 struct btrfs_dio_private *dip = bio->bi_private;
6936 int write = rw & REQ_WRITE;
6937 struct btrfs_root *root = BTRFS_I(inode)->root;
6938 int ret;
6939
6940 if (async_submit)
6941 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
6942
6943 bio_get(bio);
6944
6945 if (!write) {
6946 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
6947 if (ret)
6948 goto err;
6949 }
6950
6951 if (skip_sum)
6952 goto map;
6953
6954 if (write && async_submit) {
6955 ret = btrfs_wq_submit_bio(root->fs_info,
6956 inode, rw, bio, 0, 0,
6957 file_offset,
6958 __btrfs_submit_bio_start_direct_io,
6959 __btrfs_submit_bio_done);
6960 goto err;
6961 } else if (write) {
6962 /*
6963 * If we aren't doing async submit, calculate the csum of the
6964 * bio now.
6965 */
6966 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
6967 if (ret)
6968 goto err;
6969 } else if (!skip_sum) {
6970 ret = btrfs_lookup_bio_sums_dio(root, inode, dip, bio,
6971 file_offset);
6972 if (ret)
6973 goto err;
6974 }
6975
6976 map:
6977 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
6978 err:
6979 bio_put(bio);
6980 return ret;
6981 }
6982
6983 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
6984 int skip_sum)
6985 {
6986 struct inode *inode = dip->inode;
6987 struct btrfs_root *root = BTRFS_I(inode)->root;
6988 struct bio *bio;
6989 struct bio *orig_bio = dip->orig_bio;
6990 struct bio_vec *bvec = orig_bio->bi_io_vec;
6991 u64 start_sector = orig_bio->bi_sector;
6992 u64 file_offset = dip->logical_offset;
6993 u64 submit_len = 0;
6994 u64 map_length;
6995 int nr_pages = 0;
6996 int ret = 0;
6997 int async_submit = 0;
6998
6999 map_length = orig_bio->bi_size;
7000 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
7001 &map_length, NULL, 0);
7002 if (ret) {
7003 bio_put(orig_bio);
7004 return -EIO;
7005 }
7006
7007 if (map_length >= orig_bio->bi_size) {
7008 bio = orig_bio;
7009 goto submit;
7010 }
7011
7012 /* async crcs make it difficult to collect full stripe writes. */
7013 if (btrfs_get_alloc_profile(root, 1) &
7014 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6))
7015 async_submit = 0;
7016 else
7017 async_submit = 1;
7018
7019 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
7020 if (!bio)
7021 return -ENOMEM;
7022 bio->bi_private = dip;
7023 bio->bi_end_io = btrfs_end_dio_bio;
7024 atomic_inc(&dip->pending_bios);
7025
7026 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
7027 if (unlikely(map_length < submit_len + bvec->bv_len ||
7028 bio_add_page(bio, bvec->bv_page, bvec->bv_len,
7029 bvec->bv_offset) < bvec->bv_len)) {
7030 /*
7031 * inc the count before we submit the bio so
7032 * we know the end IO handler won't happen before
7033 * we inc the count. Otherwise, the dip might get freed
7034 * before we're done setting it up
7035 */
7036 atomic_inc(&dip->pending_bios);
7037 ret = __btrfs_submit_dio_bio(bio, inode, rw,
7038 file_offset, skip_sum,
7039 async_submit);
7040 if (ret) {
7041 bio_put(bio);
7042 atomic_dec(&dip->pending_bios);
7043 goto out_err;
7044 }
7045
7046 start_sector += submit_len >> 9;
7047 file_offset += submit_len;
7048
7049 submit_len = 0;
7050 nr_pages = 0;
7051
7052 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
7053 start_sector, GFP_NOFS);
7054 if (!bio)
7055 goto out_err;
7056 bio->bi_private = dip;
7057 bio->bi_end_io = btrfs_end_dio_bio;
7058
7059 map_length = orig_bio->bi_size;
7060 ret = btrfs_map_block(root->fs_info, rw,
7061 start_sector << 9,
7062 &map_length, NULL, 0);
7063 if (ret) {
7064 bio_put(bio);
7065 goto out_err;
7066 }
7067 } else {
7068 submit_len += bvec->bv_len;
7069 nr_pages++;
7070 bvec++;
7071 }
7072 }
7073
7074 submit:
7075 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
7076 async_submit);
7077 if (!ret)
7078 return 0;
7079
7080 bio_put(bio);
7081 out_err:
7082 dip->errors = 1;
7083 /*
7084 * before atomic variable goto zero, we must
7085 * make sure dip->errors is perceived to be set.
7086 */
7087 smp_mb__before_atomic_dec();
7088 if (atomic_dec_and_test(&dip->pending_bios))
7089 bio_io_error(dip->orig_bio);
7090
7091 /* bio_end_io() will handle error, so we needn't return it */
7092 return 0;
7093 }
7094
7095 static void btrfs_submit_direct(int rw, struct bio *dio_bio,
7096 struct inode *inode, loff_t file_offset)
7097 {
7098 struct btrfs_root *root = BTRFS_I(inode)->root;
7099 struct btrfs_dio_private *dip;
7100 struct bio *io_bio;
7101 int skip_sum;
7102 int sum_len;
7103 int write = rw & REQ_WRITE;
7104 int ret = 0;
7105 u16 csum_size;
7106
7107 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
7108
7109 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
7110 if (!io_bio) {
7111 ret = -ENOMEM;
7112 goto free_ordered;
7113 }
7114
7115 if (!skip_sum && !write) {
7116 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
7117 sum_len = dio_bio->bi_size >> inode->i_sb->s_blocksize_bits;
7118 sum_len *= csum_size;
7119 } else {
7120 sum_len = 0;
7121 }
7122
7123 dip = kmalloc(sizeof(*dip) + sum_len, GFP_NOFS);
7124 if (!dip) {
7125 ret = -ENOMEM;
7126 goto free_io_bio;
7127 }
7128
7129 dip->private = dio_bio->bi_private;
7130 dip->inode = inode;
7131 dip->logical_offset = file_offset;
7132 dip->bytes = dio_bio->bi_size;
7133 dip->disk_bytenr = (u64)dio_bio->bi_sector << 9;
7134 io_bio->bi_private = dip;
7135 dip->errors = 0;
7136 dip->orig_bio = io_bio;
7137 dip->dio_bio = dio_bio;
7138 atomic_set(&dip->pending_bios, 0);
7139
7140 if (write)
7141 io_bio->bi_end_io = btrfs_endio_direct_write;
7142 else
7143 io_bio->bi_end_io = btrfs_endio_direct_read;
7144
7145 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
7146 if (!ret)
7147 return;
7148
7149 free_io_bio:
7150 bio_put(io_bio);
7151
7152 free_ordered:
7153 /*
7154 * If this is a write, we need to clean up the reserved space and kill
7155 * the ordered extent.
7156 */
7157 if (write) {
7158 struct btrfs_ordered_extent *ordered;
7159 ordered = btrfs_lookup_ordered_extent(inode, file_offset);
7160 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
7161 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
7162 btrfs_free_reserved_extent(root, ordered->start,
7163 ordered->disk_len);
7164 btrfs_put_ordered_extent(ordered);
7165 btrfs_put_ordered_extent(ordered);
7166 }
7167 bio_endio(dio_bio, ret);
7168 }
7169
7170 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb,
7171 const struct iovec *iov, loff_t offset,
7172 unsigned long nr_segs)
7173 {
7174 int seg;
7175 int i;
7176 size_t size;
7177 unsigned long addr;
7178 unsigned blocksize_mask = root->sectorsize - 1;
7179 ssize_t retval = -EINVAL;
7180 loff_t end = offset;
7181
7182 if (offset & blocksize_mask)
7183 goto out;
7184
7185 /* Check the memory alignment. Blocks cannot straddle pages */
7186 for (seg = 0; seg < nr_segs; seg++) {
7187 addr = (unsigned long)iov[seg].iov_base;
7188 size = iov[seg].iov_len;
7189 end += size;
7190 if ((addr & blocksize_mask) || (size & blocksize_mask))
7191 goto out;
7192
7193 /* If this is a write we don't need to check anymore */
7194 if (rw & WRITE)
7195 continue;
7196
7197 /*
7198 * Check to make sure we don't have duplicate iov_base's in this
7199 * iovec, if so return EINVAL, otherwise we'll get csum errors
7200 * when reading back.
7201 */
7202 for (i = seg + 1; i < nr_segs; i++) {
7203 if (iov[seg].iov_base == iov[i].iov_base)
7204 goto out;
7205 }
7206 }
7207 retval = 0;
7208 out:
7209 return retval;
7210 }
7211
7212 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
7213 const struct iovec *iov, loff_t offset,
7214 unsigned long nr_segs)
7215 {
7216 struct file *file = iocb->ki_filp;
7217 struct inode *inode = file->f_mapping->host;
7218 size_t count = 0;
7219 int flags = 0;
7220 bool wakeup = true;
7221 bool relock = false;
7222 ssize_t ret;
7223
7224 if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
7225 offset, nr_segs))
7226 return 0;
7227
7228 atomic_inc(&inode->i_dio_count);
7229 smp_mb__after_atomic_inc();
7230
7231 /*
7232 * The generic stuff only does filemap_write_and_wait_range, which isn't
7233 * enough if we've written compressed pages to this area, so we need to
7234 * call btrfs_wait_ordered_range to make absolutely sure that any
7235 * outstanding dirty pages are on disk.
7236 */
7237 count = iov_length(iov, nr_segs);
7238 ret = btrfs_wait_ordered_range(inode, offset, count);
7239 if (ret)
7240 return ret;
7241
7242 if (rw & WRITE) {
7243 /*
7244 * If the write DIO is beyond the EOF, we need update
7245 * the isize, but it is protected by i_mutex. So we can
7246 * not unlock the i_mutex at this case.
7247 */
7248 if (offset + count <= inode->i_size) {
7249 mutex_unlock(&inode->i_mutex);
7250 relock = true;
7251 }
7252 ret = btrfs_delalloc_reserve_space(inode, count);
7253 if (ret)
7254 goto out;
7255 } else if (unlikely(test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
7256 &BTRFS_I(inode)->runtime_flags))) {
7257 inode_dio_done(inode);
7258 flags = DIO_LOCKING | DIO_SKIP_HOLES;
7259 wakeup = false;
7260 }
7261
7262 ret = __blockdev_direct_IO(rw, iocb, inode,
7263 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
7264 iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
7265 btrfs_submit_direct, flags);
7266 if (rw & WRITE) {
7267 if (ret < 0 && ret != -EIOCBQUEUED)
7268 btrfs_delalloc_release_space(inode, count);
7269 else if (ret >= 0 && (size_t)ret < count)
7270 btrfs_delalloc_release_space(inode,
7271 count - (size_t)ret);
7272 else
7273 btrfs_delalloc_release_metadata(inode, 0);
7274 }
7275 out:
7276 if (wakeup)
7277 inode_dio_done(inode);
7278 if (relock)
7279 mutex_lock(&inode->i_mutex);
7280
7281 return ret;
7282 }
7283
7284 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
7285
7286 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
7287 __u64 start, __u64 len)
7288 {
7289 int ret;
7290
7291 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
7292 if (ret)
7293 return ret;
7294
7295 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
7296 }
7297
7298 int btrfs_readpage(struct file *file, struct page *page)
7299 {
7300 struct extent_io_tree *tree;
7301 tree = &BTRFS_I(page->mapping->host)->io_tree;
7302 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
7303 }
7304
7305 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
7306 {
7307 struct extent_io_tree *tree;
7308
7309
7310 if (current->flags & PF_MEMALLOC) {
7311 redirty_page_for_writepage(wbc, page);
7312 unlock_page(page);
7313 return 0;
7314 }
7315 tree = &BTRFS_I(page->mapping->host)->io_tree;
7316 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
7317 }
7318
7319 static int btrfs_writepages(struct address_space *mapping,
7320 struct writeback_control *wbc)
7321 {
7322 struct extent_io_tree *tree;
7323
7324 tree = &BTRFS_I(mapping->host)->io_tree;
7325 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
7326 }
7327
7328 static int
7329 btrfs_readpages(struct file *file, struct address_space *mapping,
7330 struct list_head *pages, unsigned nr_pages)
7331 {
7332 struct extent_io_tree *tree;
7333 tree = &BTRFS_I(mapping->host)->io_tree;
7334 return extent_readpages(tree, mapping, pages, nr_pages,
7335 btrfs_get_extent);
7336 }
7337 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
7338 {
7339 struct extent_io_tree *tree;
7340 struct extent_map_tree *map;
7341 int ret;
7342
7343 tree = &BTRFS_I(page->mapping->host)->io_tree;
7344 map = &BTRFS_I(page->mapping->host)->extent_tree;
7345 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
7346 if (ret == 1) {
7347 ClearPagePrivate(page);
7348 set_page_private(page, 0);
7349 page_cache_release(page);
7350 }
7351 return ret;
7352 }
7353
7354 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
7355 {
7356 if (PageWriteback(page) || PageDirty(page))
7357 return 0;
7358 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
7359 }
7360
7361 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
7362 unsigned int length)
7363 {
7364 struct inode *inode = page->mapping->host;
7365 struct extent_io_tree *tree;
7366 struct btrfs_ordered_extent *ordered;
7367 struct extent_state *cached_state = NULL;
7368 u64 page_start = page_offset(page);
7369 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
7370
7371 /*
7372 * we have the page locked, so new writeback can't start,
7373 * and the dirty bit won't be cleared while we are here.
7374 *
7375 * Wait for IO on this page so that we can safely clear
7376 * the PagePrivate2 bit and do ordered accounting
7377 */
7378 wait_on_page_writeback(page);
7379
7380 tree = &BTRFS_I(inode)->io_tree;
7381 if (offset) {
7382 btrfs_releasepage(page, GFP_NOFS);
7383 return;
7384 }
7385 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
7386 ordered = btrfs_lookup_ordered_extent(inode, page_offset(page));
7387 if (ordered) {
7388 /*
7389 * IO on this page will never be started, so we need
7390 * to account for any ordered extents now
7391 */
7392 clear_extent_bit(tree, page_start, page_end,
7393 EXTENT_DIRTY | EXTENT_DELALLOC |
7394 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
7395 EXTENT_DEFRAG, 1, 0, &cached_state, GFP_NOFS);
7396 /*
7397 * whoever cleared the private bit is responsible
7398 * for the finish_ordered_io
7399 */
7400 if (TestClearPagePrivate2(page)) {
7401 struct btrfs_ordered_inode_tree *tree;
7402 u64 new_len;
7403
7404 tree = &BTRFS_I(inode)->ordered_tree;
7405
7406 spin_lock_irq(&tree->lock);
7407 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
7408 new_len = page_start - ordered->file_offset;
7409 if (new_len < ordered->truncated_len)
7410 ordered->truncated_len = new_len;
7411 spin_unlock_irq(&tree->lock);
7412
7413 if (btrfs_dec_test_ordered_pending(inode, &ordered,
7414 page_start,
7415 PAGE_CACHE_SIZE, 1))
7416 btrfs_finish_ordered_io(ordered);
7417 }
7418 btrfs_put_ordered_extent(ordered);
7419 cached_state = NULL;
7420 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
7421 }
7422 clear_extent_bit(tree, page_start, page_end,
7423 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
7424 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
7425 &cached_state, GFP_NOFS);
7426 __btrfs_releasepage(page, GFP_NOFS);
7427
7428 ClearPageChecked(page);
7429 if (PagePrivate(page)) {
7430 ClearPagePrivate(page);
7431 set_page_private(page, 0);
7432 page_cache_release(page);
7433 }
7434 }
7435
7436 /*
7437 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
7438 * called from a page fault handler when a page is first dirtied. Hence we must
7439 * be careful to check for EOF conditions here. We set the page up correctly
7440 * for a written page which means we get ENOSPC checking when writing into
7441 * holes and correct delalloc and unwritten extent mapping on filesystems that
7442 * support these features.
7443 *
7444 * We are not allowed to take the i_mutex here so we have to play games to
7445 * protect against truncate races as the page could now be beyond EOF. Because
7446 * vmtruncate() writes the inode size before removing pages, once we have the
7447 * page lock we can determine safely if the page is beyond EOF. If it is not
7448 * beyond EOF, then the page is guaranteed safe against truncation until we
7449 * unlock the page.
7450 */
7451 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
7452 {
7453 struct page *page = vmf->page;
7454 struct inode *inode = file_inode(vma->vm_file);
7455 struct btrfs_root *root = BTRFS_I(inode)->root;
7456 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7457 struct btrfs_ordered_extent *ordered;
7458 struct extent_state *cached_state = NULL;
7459 char *kaddr;
7460 unsigned long zero_start;
7461 loff_t size;
7462 int ret;
7463 int reserved = 0;
7464 u64 page_start;
7465 u64 page_end;
7466
7467 sb_start_pagefault(inode->i_sb);
7468 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
7469 if (!ret) {
7470 ret = file_update_time(vma->vm_file);
7471 reserved = 1;
7472 }
7473 if (ret) {
7474 if (ret == -ENOMEM)
7475 ret = VM_FAULT_OOM;
7476 else /* -ENOSPC, -EIO, etc */
7477 ret = VM_FAULT_SIGBUS;
7478 if (reserved)
7479 goto out;
7480 goto out_noreserve;
7481 }
7482
7483 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
7484 again:
7485 lock_page(page);
7486 size = i_size_read(inode);
7487 page_start = page_offset(page);
7488 page_end = page_start + PAGE_CACHE_SIZE - 1;
7489
7490 if ((page->mapping != inode->i_mapping) ||
7491 (page_start >= size)) {
7492 /* page got truncated out from underneath us */
7493 goto out_unlock;
7494 }
7495 wait_on_page_writeback(page);
7496
7497 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
7498 set_page_extent_mapped(page);
7499
7500 /*
7501 * we can't set the delalloc bits if there are pending ordered
7502 * extents. Drop our locks and wait for them to finish
7503 */
7504 ordered = btrfs_lookup_ordered_extent(inode, page_start);
7505 if (ordered) {
7506 unlock_extent_cached(io_tree, page_start, page_end,
7507 &cached_state, GFP_NOFS);
7508 unlock_page(page);
7509 btrfs_start_ordered_extent(inode, ordered, 1);
7510 btrfs_put_ordered_extent(ordered);
7511 goto again;
7512 }
7513
7514 /*
7515 * XXX - page_mkwrite gets called every time the page is dirtied, even
7516 * if it was already dirty, so for space accounting reasons we need to
7517 * clear any delalloc bits for the range we are fixing to save. There
7518 * is probably a better way to do this, but for now keep consistent with
7519 * prepare_pages in the normal write path.
7520 */
7521 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
7522 EXTENT_DIRTY | EXTENT_DELALLOC |
7523 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
7524 0, 0, &cached_state, GFP_NOFS);
7525
7526 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
7527 &cached_state);
7528 if (ret) {
7529 unlock_extent_cached(io_tree, page_start, page_end,
7530 &cached_state, GFP_NOFS);
7531 ret = VM_FAULT_SIGBUS;
7532 goto out_unlock;
7533 }
7534 ret = 0;
7535
7536 /* page is wholly or partially inside EOF */
7537 if (page_start + PAGE_CACHE_SIZE > size)
7538 zero_start = size & ~PAGE_CACHE_MASK;
7539 else
7540 zero_start = PAGE_CACHE_SIZE;
7541
7542 if (zero_start != PAGE_CACHE_SIZE) {
7543 kaddr = kmap(page);
7544 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
7545 flush_dcache_page(page);
7546 kunmap(page);
7547 }
7548 ClearPageChecked(page);
7549 set_page_dirty(page);
7550 SetPageUptodate(page);
7551
7552 BTRFS_I(inode)->last_trans = root->fs_info->generation;
7553 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
7554 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
7555
7556 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
7557
7558 out_unlock:
7559 if (!ret) {
7560 sb_end_pagefault(inode->i_sb);
7561 return VM_FAULT_LOCKED;
7562 }
7563 unlock_page(page);
7564 out:
7565 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
7566 out_noreserve:
7567 sb_end_pagefault(inode->i_sb);
7568 return ret;
7569 }
7570
7571 static int btrfs_truncate(struct inode *inode)
7572 {
7573 struct btrfs_root *root = BTRFS_I(inode)->root;
7574 struct btrfs_block_rsv *rsv;
7575 int ret = 0;
7576 int err = 0;
7577 struct btrfs_trans_handle *trans;
7578 u64 mask = root->sectorsize - 1;
7579 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
7580
7581 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
7582 (u64)-1);
7583 if (ret)
7584 return ret;
7585
7586 /*
7587 * Yes ladies and gentelment, this is indeed ugly. The fact is we have
7588 * 3 things going on here
7589 *
7590 * 1) We need to reserve space for our orphan item and the space to
7591 * delete our orphan item. Lord knows we don't want to have a dangling
7592 * orphan item because we didn't reserve space to remove it.
7593 *
7594 * 2) We need to reserve space to update our inode.
7595 *
7596 * 3) We need to have something to cache all the space that is going to
7597 * be free'd up by the truncate operation, but also have some slack
7598 * space reserved in case it uses space during the truncate (thank you
7599 * very much snapshotting).
7600 *
7601 * And we need these to all be seperate. The fact is we can use alot of
7602 * space doing the truncate, and we have no earthly idea how much space
7603 * we will use, so we need the truncate reservation to be seperate so it
7604 * doesn't end up using space reserved for updating the inode or
7605 * removing the orphan item. We also need to be able to stop the
7606 * transaction and start a new one, which means we need to be able to
7607 * update the inode several times, and we have no idea of knowing how
7608 * many times that will be, so we can't just reserve 1 item for the
7609 * entirety of the opration, so that has to be done seperately as well.
7610 * Then there is the orphan item, which does indeed need to be held on
7611 * to for the whole operation, and we need nobody to touch this reserved
7612 * space except the orphan code.
7613 *
7614 * So that leaves us with
7615 *
7616 * 1) root->orphan_block_rsv - for the orphan deletion.
7617 * 2) rsv - for the truncate reservation, which we will steal from the
7618 * transaction reservation.
7619 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
7620 * updating the inode.
7621 */
7622 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
7623 if (!rsv)
7624 return -ENOMEM;
7625 rsv->size = min_size;
7626 rsv->failfast = 1;
7627
7628 /*
7629 * 1 for the truncate slack space
7630 * 1 for updating the inode.
7631 */
7632 trans = btrfs_start_transaction(root, 2);
7633 if (IS_ERR(trans)) {
7634 err = PTR_ERR(trans);
7635 goto out;
7636 }
7637
7638 /* Migrate the slack space for the truncate to our reserve */
7639 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
7640 min_size);
7641 BUG_ON(ret);
7642
7643 /*
7644 * setattr is responsible for setting the ordered_data_close flag,
7645 * but that is only tested during the last file release. That
7646 * could happen well after the next commit, leaving a great big
7647 * window where new writes may get lost if someone chooses to write
7648 * to this file after truncating to zero
7649 *
7650 * The inode doesn't have any dirty data here, and so if we commit
7651 * this is a noop. If someone immediately starts writing to the inode
7652 * it is very likely we'll catch some of their writes in this
7653 * transaction, and the commit will find this file on the ordered
7654 * data list with good things to send down.
7655 *
7656 * This is a best effort solution, there is still a window where
7657 * using truncate to replace the contents of the file will
7658 * end up with a zero length file after a crash.
7659 */
7660 if (inode->i_size == 0 && test_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
7661 &BTRFS_I(inode)->runtime_flags))
7662 btrfs_add_ordered_operation(trans, root, inode);
7663
7664 /*
7665 * So if we truncate and then write and fsync we normally would just
7666 * write the extents that changed, which is a problem if we need to
7667 * first truncate that entire inode. So set this flag so we write out
7668 * all of the extents in the inode to the sync log so we're completely
7669 * safe.
7670 */
7671 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
7672 trans->block_rsv = rsv;
7673
7674 while (1) {
7675 ret = btrfs_truncate_inode_items(trans, root, inode,
7676 inode->i_size,
7677 BTRFS_EXTENT_DATA_KEY);
7678 if (ret != -ENOSPC) {
7679 err = ret;
7680 break;
7681 }
7682
7683 trans->block_rsv = &root->fs_info->trans_block_rsv;
7684 ret = btrfs_update_inode(trans, root, inode);
7685 if (ret) {
7686 err = ret;
7687 break;
7688 }
7689
7690 btrfs_end_transaction(trans, root);
7691 btrfs_btree_balance_dirty(root);
7692
7693 trans = btrfs_start_transaction(root, 2);
7694 if (IS_ERR(trans)) {
7695 ret = err = PTR_ERR(trans);
7696 trans = NULL;
7697 break;
7698 }
7699
7700 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
7701 rsv, min_size);
7702 BUG_ON(ret); /* shouldn't happen */
7703 trans->block_rsv = rsv;
7704 }
7705
7706 if (ret == 0 && inode->i_nlink > 0) {
7707 trans->block_rsv = root->orphan_block_rsv;
7708 ret = btrfs_orphan_del(trans, inode);
7709 if (ret)
7710 err = ret;
7711 }
7712
7713 if (trans) {
7714 trans->block_rsv = &root->fs_info->trans_block_rsv;
7715 ret = btrfs_update_inode(trans, root, inode);
7716 if (ret && !err)
7717 err = ret;
7718
7719 ret = btrfs_end_transaction(trans, root);
7720 btrfs_btree_balance_dirty(root);
7721 }
7722
7723 out:
7724 btrfs_free_block_rsv(root, rsv);
7725
7726 if (ret && !err)
7727 err = ret;
7728
7729 return err;
7730 }
7731
7732 /*
7733 * create a new subvolume directory/inode (helper for the ioctl).
7734 */
7735 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
7736 struct btrfs_root *new_root, u64 new_dirid)
7737 {
7738 struct inode *inode;
7739 int err;
7740 u64 index = 0;
7741
7742 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
7743 new_dirid, new_dirid,
7744 S_IFDIR | (~current_umask() & S_IRWXUGO),
7745 &index);
7746 if (IS_ERR(inode))
7747 return PTR_ERR(inode);
7748 inode->i_op = &btrfs_dir_inode_operations;
7749 inode->i_fop = &btrfs_dir_file_operations;
7750
7751 set_nlink(inode, 1);
7752 btrfs_i_size_write(inode, 0);
7753
7754 err = btrfs_update_inode(trans, new_root, inode);
7755
7756 iput(inode);
7757 return err;
7758 }
7759
7760 struct inode *btrfs_alloc_inode(struct super_block *sb)
7761 {
7762 struct btrfs_inode *ei;
7763 struct inode *inode;
7764
7765 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
7766 if (!ei)
7767 return NULL;
7768
7769 ei->root = NULL;
7770 ei->generation = 0;
7771 ei->last_trans = 0;
7772 ei->last_sub_trans = 0;
7773 ei->logged_trans = 0;
7774 ei->delalloc_bytes = 0;
7775 ei->disk_i_size = 0;
7776 ei->flags = 0;
7777 ei->csum_bytes = 0;
7778 ei->index_cnt = (u64)-1;
7779 ei->last_unlink_trans = 0;
7780 ei->last_log_commit = 0;
7781
7782 spin_lock_init(&ei->lock);
7783 ei->outstanding_extents = 0;
7784 ei->reserved_extents = 0;
7785
7786 ei->runtime_flags = 0;
7787 ei->force_compress = BTRFS_COMPRESS_NONE;
7788
7789 ei->delayed_node = NULL;
7790
7791 inode = &ei->vfs_inode;
7792 extent_map_tree_init(&ei->extent_tree);
7793 extent_io_tree_init(&ei->io_tree, &inode->i_data);
7794 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
7795 ei->io_tree.track_uptodate = 1;
7796 ei->io_failure_tree.track_uptodate = 1;
7797 atomic_set(&ei->sync_writers, 0);
7798 mutex_init(&ei->log_mutex);
7799 mutex_init(&ei->delalloc_mutex);
7800 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
7801 INIT_LIST_HEAD(&ei->delalloc_inodes);
7802 INIT_LIST_HEAD(&ei->ordered_operations);
7803 RB_CLEAR_NODE(&ei->rb_node);
7804
7805 return inode;
7806 }
7807
7808 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
7809 void btrfs_test_destroy_inode(struct inode *inode)
7810 {
7811 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
7812 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
7813 }
7814 #endif
7815
7816 static void btrfs_i_callback(struct rcu_head *head)
7817 {
7818 struct inode *inode = container_of(head, struct inode, i_rcu);
7819 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
7820 }
7821
7822 void btrfs_destroy_inode(struct inode *inode)
7823 {
7824 struct btrfs_ordered_extent *ordered;
7825 struct btrfs_root *root = BTRFS_I(inode)->root;
7826
7827 WARN_ON(!hlist_empty(&inode->i_dentry));
7828 WARN_ON(inode->i_data.nrpages);
7829 WARN_ON(BTRFS_I(inode)->outstanding_extents);
7830 WARN_ON(BTRFS_I(inode)->reserved_extents);
7831 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
7832 WARN_ON(BTRFS_I(inode)->csum_bytes);
7833
7834 /*
7835 * This can happen where we create an inode, but somebody else also
7836 * created the same inode and we need to destroy the one we already
7837 * created.
7838 */
7839 if (!root)
7840 goto free;
7841
7842 /*
7843 * Make sure we're properly removed from the ordered operation
7844 * lists.
7845 */
7846 smp_mb();
7847 if (!list_empty(&BTRFS_I(inode)->ordered_operations)) {
7848 spin_lock(&root->fs_info->ordered_root_lock);
7849 list_del_init(&BTRFS_I(inode)->ordered_operations);
7850 spin_unlock(&root->fs_info->ordered_root_lock);
7851 }
7852
7853 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
7854 &BTRFS_I(inode)->runtime_flags)) {
7855 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
7856 btrfs_ino(inode));
7857 atomic_dec(&root->orphan_inodes);
7858 }
7859
7860 while (1) {
7861 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
7862 if (!ordered)
7863 break;
7864 else {
7865 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
7866 ordered->file_offset, ordered->len);
7867 btrfs_remove_ordered_extent(inode, ordered);
7868 btrfs_put_ordered_extent(ordered);
7869 btrfs_put_ordered_extent(ordered);
7870 }
7871 }
7872 inode_tree_del(inode);
7873 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
7874 free:
7875 call_rcu(&inode->i_rcu, btrfs_i_callback);
7876 }
7877
7878 int btrfs_drop_inode(struct inode *inode)
7879 {
7880 struct btrfs_root *root = BTRFS_I(inode)->root;
7881
7882 if (root == NULL)
7883 return 1;
7884
7885 /* the snap/subvol tree is on deleting */
7886 if (btrfs_root_refs(&root->root_item) == 0)
7887 return 1;
7888 else
7889 return generic_drop_inode(inode);
7890 }
7891
7892 static void init_once(void *foo)
7893 {
7894 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
7895
7896 inode_init_once(&ei->vfs_inode);
7897 }
7898
7899 void btrfs_destroy_cachep(void)
7900 {
7901 /*
7902 * Make sure all delayed rcu free inodes are flushed before we
7903 * destroy cache.
7904 */
7905 rcu_barrier();
7906 if (btrfs_inode_cachep)
7907 kmem_cache_destroy(btrfs_inode_cachep);
7908 if (btrfs_trans_handle_cachep)
7909 kmem_cache_destroy(btrfs_trans_handle_cachep);
7910 if (btrfs_transaction_cachep)
7911 kmem_cache_destroy(btrfs_transaction_cachep);
7912 if (btrfs_path_cachep)
7913 kmem_cache_destroy(btrfs_path_cachep);
7914 if (btrfs_free_space_cachep)
7915 kmem_cache_destroy(btrfs_free_space_cachep);
7916 if (btrfs_delalloc_work_cachep)
7917 kmem_cache_destroy(btrfs_delalloc_work_cachep);
7918 }
7919
7920 int btrfs_init_cachep(void)
7921 {
7922 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
7923 sizeof(struct btrfs_inode), 0,
7924 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
7925 if (!btrfs_inode_cachep)
7926 goto fail;
7927
7928 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
7929 sizeof(struct btrfs_trans_handle), 0,
7930 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7931 if (!btrfs_trans_handle_cachep)
7932 goto fail;
7933
7934 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
7935 sizeof(struct btrfs_transaction), 0,
7936 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7937 if (!btrfs_transaction_cachep)
7938 goto fail;
7939
7940 btrfs_path_cachep = kmem_cache_create("btrfs_path",
7941 sizeof(struct btrfs_path), 0,
7942 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7943 if (!btrfs_path_cachep)
7944 goto fail;
7945
7946 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
7947 sizeof(struct btrfs_free_space), 0,
7948 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7949 if (!btrfs_free_space_cachep)
7950 goto fail;
7951
7952 btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work",
7953 sizeof(struct btrfs_delalloc_work), 0,
7954 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
7955 NULL);
7956 if (!btrfs_delalloc_work_cachep)
7957 goto fail;
7958
7959 return 0;
7960 fail:
7961 btrfs_destroy_cachep();
7962 return -ENOMEM;
7963 }
7964
7965 static int btrfs_getattr(struct vfsmount *mnt,
7966 struct dentry *dentry, struct kstat *stat)
7967 {
7968 u64 delalloc_bytes;
7969 struct inode *inode = dentry->d_inode;
7970 u32 blocksize = inode->i_sb->s_blocksize;
7971
7972 generic_fillattr(inode, stat);
7973 stat->dev = BTRFS_I(inode)->root->anon_dev;
7974 stat->blksize = PAGE_CACHE_SIZE;
7975
7976 spin_lock(&BTRFS_I(inode)->lock);
7977 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
7978 spin_unlock(&BTRFS_I(inode)->lock);
7979 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
7980 ALIGN(delalloc_bytes, blocksize)) >> 9;
7981 return 0;
7982 }
7983
7984 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
7985 struct inode *new_dir, struct dentry *new_dentry)
7986 {
7987 struct btrfs_trans_handle *trans;
7988 struct btrfs_root *root = BTRFS_I(old_dir)->root;
7989 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
7990 struct inode *new_inode = new_dentry->d_inode;
7991 struct inode *old_inode = old_dentry->d_inode;
7992 struct timespec ctime = CURRENT_TIME;
7993 u64 index = 0;
7994 u64 root_objectid;
7995 int ret;
7996 u64 old_ino = btrfs_ino(old_inode);
7997
7998 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
7999 return -EPERM;
8000
8001 /* we only allow rename subvolume link between subvolumes */
8002 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
8003 return -EXDEV;
8004
8005 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
8006 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
8007 return -ENOTEMPTY;
8008
8009 if (S_ISDIR(old_inode->i_mode) && new_inode &&
8010 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
8011 return -ENOTEMPTY;
8012
8013
8014 /* check for collisions, even if the name isn't there */
8015 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
8016 new_dentry->d_name.name,
8017 new_dentry->d_name.len);
8018
8019 if (ret) {
8020 if (ret == -EEXIST) {
8021 /* we shouldn't get
8022 * eexist without a new_inode */
8023 if (WARN_ON(!new_inode)) {
8024 return ret;
8025 }
8026 } else {
8027 /* maybe -EOVERFLOW */
8028 return ret;
8029 }
8030 }
8031 ret = 0;
8032
8033 /*
8034 * we're using rename to replace one file with another.
8035 * and the replacement file is large. Start IO on it now so
8036 * we don't add too much work to the end of the transaction
8037 */
8038 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size &&
8039 old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
8040 filemap_flush(old_inode->i_mapping);
8041
8042 /* close the racy window with snapshot create/destroy ioctl */
8043 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
8044 down_read(&root->fs_info->subvol_sem);
8045 /*
8046 * We want to reserve the absolute worst case amount of items. So if
8047 * both inodes are subvols and we need to unlink them then that would
8048 * require 4 item modifications, but if they are both normal inodes it
8049 * would require 5 item modifications, so we'll assume their normal
8050 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
8051 * should cover the worst case number of items we'll modify.
8052 */
8053 trans = btrfs_start_transaction(root, 11);
8054 if (IS_ERR(trans)) {
8055 ret = PTR_ERR(trans);
8056 goto out_notrans;
8057 }
8058
8059 if (dest != root)
8060 btrfs_record_root_in_trans(trans, dest);
8061
8062 ret = btrfs_set_inode_index(new_dir, &index);
8063 if (ret)
8064 goto out_fail;
8065
8066 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
8067 /* force full log commit if subvolume involved. */
8068 root->fs_info->last_trans_log_full_commit = trans->transid;
8069 } else {
8070 ret = btrfs_insert_inode_ref(trans, dest,
8071 new_dentry->d_name.name,
8072 new_dentry->d_name.len,
8073 old_ino,
8074 btrfs_ino(new_dir), index);
8075 if (ret)
8076 goto out_fail;
8077 /*
8078 * this is an ugly little race, but the rename is required
8079 * to make sure that if we crash, the inode is either at the
8080 * old name or the new one. pinning the log transaction lets
8081 * us make sure we don't allow a log commit to come in after
8082 * we unlink the name but before we add the new name back in.
8083 */
8084 btrfs_pin_log_trans(root);
8085 }
8086 /*
8087 * make sure the inode gets flushed if it is replacing
8088 * something.
8089 */
8090 if (new_inode && new_inode->i_size && S_ISREG(old_inode->i_mode))
8091 btrfs_add_ordered_operation(trans, root, old_inode);
8092
8093 inode_inc_iversion(old_dir);
8094 inode_inc_iversion(new_dir);
8095 inode_inc_iversion(old_inode);
8096 old_dir->i_ctime = old_dir->i_mtime = ctime;
8097 new_dir->i_ctime = new_dir->i_mtime = ctime;
8098 old_inode->i_ctime = ctime;
8099
8100 if (old_dentry->d_parent != new_dentry->d_parent)
8101 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
8102
8103 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
8104 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
8105 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
8106 old_dentry->d_name.name,
8107 old_dentry->d_name.len);
8108 } else {
8109 ret = __btrfs_unlink_inode(trans, root, old_dir,
8110 old_dentry->d_inode,
8111 old_dentry->d_name.name,
8112 old_dentry->d_name.len);
8113 if (!ret)
8114 ret = btrfs_update_inode(trans, root, old_inode);
8115 }
8116 if (ret) {
8117 btrfs_abort_transaction(trans, root, ret);
8118 goto out_fail;
8119 }
8120
8121 if (new_inode) {
8122 inode_inc_iversion(new_inode);
8123 new_inode->i_ctime = CURRENT_TIME;
8124 if (unlikely(btrfs_ino(new_inode) ==
8125 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
8126 root_objectid = BTRFS_I(new_inode)->location.objectid;
8127 ret = btrfs_unlink_subvol(trans, dest, new_dir,
8128 root_objectid,
8129 new_dentry->d_name.name,
8130 new_dentry->d_name.len);
8131 BUG_ON(new_inode->i_nlink == 0);
8132 } else {
8133 ret = btrfs_unlink_inode(trans, dest, new_dir,
8134 new_dentry->d_inode,
8135 new_dentry->d_name.name,
8136 new_dentry->d_name.len);
8137 }
8138 if (!ret && new_inode->i_nlink == 0)
8139 ret = btrfs_orphan_add(trans, new_dentry->d_inode);
8140 if (ret) {
8141 btrfs_abort_transaction(trans, root, ret);
8142 goto out_fail;
8143 }
8144 }
8145
8146 ret = btrfs_add_link(trans, new_dir, old_inode,
8147 new_dentry->d_name.name,
8148 new_dentry->d_name.len, 0, index);
8149 if (ret) {
8150 btrfs_abort_transaction(trans, root, ret);
8151 goto out_fail;
8152 }
8153
8154 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
8155 struct dentry *parent = new_dentry->d_parent;
8156 btrfs_log_new_name(trans, old_inode, old_dir, parent);
8157 btrfs_end_log_trans(root);
8158 }
8159 out_fail:
8160 btrfs_end_transaction(trans, root);
8161 out_notrans:
8162 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
8163 up_read(&root->fs_info->subvol_sem);
8164
8165 return ret;
8166 }
8167
8168 static void btrfs_run_delalloc_work(struct btrfs_work *work)
8169 {
8170 struct btrfs_delalloc_work *delalloc_work;
8171 struct inode *inode;
8172
8173 delalloc_work = container_of(work, struct btrfs_delalloc_work,
8174 work);
8175 inode = delalloc_work->inode;
8176 if (delalloc_work->wait) {
8177 btrfs_wait_ordered_range(inode, 0, (u64)-1);
8178 } else {
8179 filemap_flush(inode->i_mapping);
8180 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8181 &BTRFS_I(inode)->runtime_flags))
8182 filemap_flush(inode->i_mapping);
8183 }
8184
8185 if (delalloc_work->delay_iput)
8186 btrfs_add_delayed_iput(inode);
8187 else
8188 iput(inode);
8189 complete(&delalloc_work->completion);
8190 }
8191
8192 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
8193 int wait, int delay_iput)
8194 {
8195 struct btrfs_delalloc_work *work;
8196
8197 work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS);
8198 if (!work)
8199 return NULL;
8200
8201 init_completion(&work->completion);
8202 INIT_LIST_HEAD(&work->list);
8203 work->inode = inode;
8204 work->wait = wait;
8205 work->delay_iput = delay_iput;
8206 work->work.func = btrfs_run_delalloc_work;
8207
8208 return work;
8209 }
8210
8211 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
8212 {
8213 wait_for_completion(&work->completion);
8214 kmem_cache_free(btrfs_delalloc_work_cachep, work);
8215 }
8216
8217 /*
8218 * some fairly slow code that needs optimization. This walks the list
8219 * of all the inodes with pending delalloc and forces them to disk.
8220 */
8221 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
8222 {
8223 struct btrfs_inode *binode;
8224 struct inode *inode;
8225 struct btrfs_delalloc_work *work, *next;
8226 struct list_head works;
8227 struct list_head splice;
8228 int ret = 0;
8229
8230 INIT_LIST_HEAD(&works);
8231 INIT_LIST_HEAD(&splice);
8232
8233 spin_lock(&root->delalloc_lock);
8234 list_splice_init(&root->delalloc_inodes, &splice);
8235 while (!list_empty(&splice)) {
8236 binode = list_entry(splice.next, struct btrfs_inode,
8237 delalloc_inodes);
8238
8239 list_move_tail(&binode->delalloc_inodes,
8240 &root->delalloc_inodes);
8241 inode = igrab(&binode->vfs_inode);
8242 if (!inode) {
8243 cond_resched_lock(&root->delalloc_lock);
8244 continue;
8245 }
8246 spin_unlock(&root->delalloc_lock);
8247
8248 work = btrfs_alloc_delalloc_work(inode, 0, delay_iput);
8249 if (unlikely(!work)) {
8250 if (delay_iput)
8251 btrfs_add_delayed_iput(inode);
8252 else
8253 iput(inode);
8254 ret = -ENOMEM;
8255 goto out;
8256 }
8257 list_add_tail(&work->list, &works);
8258 btrfs_queue_worker(&root->fs_info->flush_workers,
8259 &work->work);
8260
8261 cond_resched();
8262 spin_lock(&root->delalloc_lock);
8263 }
8264 spin_unlock(&root->delalloc_lock);
8265
8266 list_for_each_entry_safe(work, next, &works, list) {
8267 list_del_init(&work->list);
8268 btrfs_wait_and_free_delalloc_work(work);
8269 }
8270 return 0;
8271 out:
8272 list_for_each_entry_safe(work, next, &works, list) {
8273 list_del_init(&work->list);
8274 btrfs_wait_and_free_delalloc_work(work);
8275 }
8276
8277 if (!list_empty_careful(&splice)) {
8278 spin_lock(&root->delalloc_lock);
8279 list_splice_tail(&splice, &root->delalloc_inodes);
8280 spin_unlock(&root->delalloc_lock);
8281 }
8282 return ret;
8283 }
8284
8285 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
8286 {
8287 int ret;
8288
8289 if (root->fs_info->sb->s_flags & MS_RDONLY)
8290 return -EROFS;
8291
8292 ret = __start_delalloc_inodes(root, delay_iput);
8293 /*
8294 * the filemap_flush will queue IO into the worker threads, but
8295 * we have to make sure the IO is actually started and that
8296 * ordered extents get created before we return
8297 */
8298 atomic_inc(&root->fs_info->async_submit_draining);
8299 while (atomic_read(&root->fs_info->nr_async_submits) ||
8300 atomic_read(&root->fs_info->async_delalloc_pages)) {
8301 wait_event(root->fs_info->async_submit_wait,
8302 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
8303 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
8304 }
8305 atomic_dec(&root->fs_info->async_submit_draining);
8306 return ret;
8307 }
8308
8309 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput)
8310 {
8311 struct btrfs_root *root;
8312 struct list_head splice;
8313 int ret;
8314
8315 if (fs_info->sb->s_flags & MS_RDONLY)
8316 return -EROFS;
8317
8318 INIT_LIST_HEAD(&splice);
8319
8320 spin_lock(&fs_info->delalloc_root_lock);
8321 list_splice_init(&fs_info->delalloc_roots, &splice);
8322 while (!list_empty(&splice)) {
8323 root = list_first_entry(&splice, struct btrfs_root,
8324 delalloc_root);
8325 root = btrfs_grab_fs_root(root);
8326 BUG_ON(!root);
8327 list_move_tail(&root->delalloc_root,
8328 &fs_info->delalloc_roots);
8329 spin_unlock(&fs_info->delalloc_root_lock);
8330
8331 ret = __start_delalloc_inodes(root, delay_iput);
8332 btrfs_put_fs_root(root);
8333 if (ret)
8334 goto out;
8335
8336 spin_lock(&fs_info->delalloc_root_lock);
8337 }
8338 spin_unlock(&fs_info->delalloc_root_lock);
8339
8340 atomic_inc(&fs_info->async_submit_draining);
8341 while (atomic_read(&fs_info->nr_async_submits) ||
8342 atomic_read(&fs_info->async_delalloc_pages)) {
8343 wait_event(fs_info->async_submit_wait,
8344 (atomic_read(&fs_info->nr_async_submits) == 0 &&
8345 atomic_read(&fs_info->async_delalloc_pages) == 0));
8346 }
8347 atomic_dec(&fs_info->async_submit_draining);
8348 return 0;
8349 out:
8350 if (!list_empty_careful(&splice)) {
8351 spin_lock(&fs_info->delalloc_root_lock);
8352 list_splice_tail(&splice, &fs_info->delalloc_roots);
8353 spin_unlock(&fs_info->delalloc_root_lock);
8354 }
8355 return ret;
8356 }
8357
8358 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
8359 const char *symname)
8360 {
8361 struct btrfs_trans_handle *trans;
8362 struct btrfs_root *root = BTRFS_I(dir)->root;
8363 struct btrfs_path *path;
8364 struct btrfs_key key;
8365 struct inode *inode = NULL;
8366 int err;
8367 int drop_inode = 0;
8368 u64 objectid;
8369 u64 index = 0;
8370 int name_len;
8371 int datasize;
8372 unsigned long ptr;
8373 struct btrfs_file_extent_item *ei;
8374 struct extent_buffer *leaf;
8375
8376 name_len = strlen(symname);
8377 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
8378 return -ENAMETOOLONG;
8379
8380 /*
8381 * 2 items for inode item and ref
8382 * 2 items for dir items
8383 * 1 item for xattr if selinux is on
8384 */
8385 trans = btrfs_start_transaction(root, 5);
8386 if (IS_ERR(trans))
8387 return PTR_ERR(trans);
8388
8389 err = btrfs_find_free_ino(root, &objectid);
8390 if (err)
8391 goto out_unlock;
8392
8393 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
8394 dentry->d_name.len, btrfs_ino(dir), objectid,
8395 S_IFLNK|S_IRWXUGO, &index);
8396 if (IS_ERR(inode)) {
8397 err = PTR_ERR(inode);
8398 goto out_unlock;
8399 }
8400
8401 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
8402 if (err) {
8403 drop_inode = 1;
8404 goto out_unlock;
8405 }
8406
8407 /*
8408 * If the active LSM wants to access the inode during
8409 * d_instantiate it needs these. Smack checks to see
8410 * if the filesystem supports xattrs by looking at the
8411 * ops vector.
8412 */
8413 inode->i_fop = &btrfs_file_operations;
8414 inode->i_op = &btrfs_file_inode_operations;
8415
8416 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
8417 if (err)
8418 drop_inode = 1;
8419 else {
8420 inode->i_mapping->a_ops = &btrfs_aops;
8421 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
8422 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
8423 }
8424 if (drop_inode)
8425 goto out_unlock;
8426
8427 path = btrfs_alloc_path();
8428 if (!path) {
8429 err = -ENOMEM;
8430 drop_inode = 1;
8431 goto out_unlock;
8432 }
8433 key.objectid = btrfs_ino(inode);
8434 key.offset = 0;
8435 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
8436 datasize = btrfs_file_extent_calc_inline_size(name_len);
8437 err = btrfs_insert_empty_item(trans, root, path, &key,
8438 datasize);
8439 if (err) {
8440 drop_inode = 1;
8441 btrfs_free_path(path);
8442 goto out_unlock;
8443 }
8444 leaf = path->nodes[0];
8445 ei = btrfs_item_ptr(leaf, path->slots[0],
8446 struct btrfs_file_extent_item);
8447 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
8448 btrfs_set_file_extent_type(leaf, ei,
8449 BTRFS_FILE_EXTENT_INLINE);
8450 btrfs_set_file_extent_encryption(leaf, ei, 0);
8451 btrfs_set_file_extent_compression(leaf, ei, 0);
8452 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
8453 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
8454
8455 ptr = btrfs_file_extent_inline_start(ei);
8456 write_extent_buffer(leaf, symname, ptr, name_len);
8457 btrfs_mark_buffer_dirty(leaf);
8458 btrfs_free_path(path);
8459
8460 inode->i_op = &btrfs_symlink_inode_operations;
8461 inode->i_mapping->a_ops = &btrfs_symlink_aops;
8462 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
8463 inode_set_bytes(inode, name_len);
8464 btrfs_i_size_write(inode, name_len);
8465 err = btrfs_update_inode(trans, root, inode);
8466 if (err)
8467 drop_inode = 1;
8468
8469 out_unlock:
8470 if (!err)
8471 d_instantiate(dentry, inode);
8472 btrfs_end_transaction(trans, root);
8473 if (drop_inode) {
8474 inode_dec_link_count(inode);
8475 iput(inode);
8476 }
8477 btrfs_btree_balance_dirty(root);
8478 return err;
8479 }
8480
8481 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
8482 u64 start, u64 num_bytes, u64 min_size,
8483 loff_t actual_len, u64 *alloc_hint,
8484 struct btrfs_trans_handle *trans)
8485 {
8486 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
8487 struct extent_map *em;
8488 struct btrfs_root *root = BTRFS_I(inode)->root;
8489 struct btrfs_key ins;
8490 u64 cur_offset = start;
8491 u64 i_size;
8492 u64 cur_bytes;
8493 int ret = 0;
8494 bool own_trans = true;
8495
8496 if (trans)
8497 own_trans = false;
8498 while (num_bytes > 0) {
8499 if (own_trans) {
8500 trans = btrfs_start_transaction(root, 3);
8501 if (IS_ERR(trans)) {
8502 ret = PTR_ERR(trans);
8503 break;
8504 }
8505 }
8506
8507 cur_bytes = min(num_bytes, 256ULL * 1024 * 1024);
8508 cur_bytes = max(cur_bytes, min_size);
8509 ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0,
8510 *alloc_hint, &ins, 1);
8511 if (ret) {
8512 if (own_trans)
8513 btrfs_end_transaction(trans, root);
8514 break;
8515 }
8516
8517 ret = insert_reserved_file_extent(trans, inode,
8518 cur_offset, ins.objectid,
8519 ins.offset, ins.offset,
8520 ins.offset, 0, 0, 0,
8521 BTRFS_FILE_EXTENT_PREALLOC);
8522 if (ret) {
8523 btrfs_free_reserved_extent(root, ins.objectid,
8524 ins.offset);
8525 btrfs_abort_transaction(trans, root, ret);
8526 if (own_trans)
8527 btrfs_end_transaction(trans, root);
8528 break;
8529 }
8530 btrfs_drop_extent_cache(inode, cur_offset,
8531 cur_offset + ins.offset -1, 0);
8532
8533 em = alloc_extent_map();
8534 if (!em) {
8535 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
8536 &BTRFS_I(inode)->runtime_flags);
8537 goto next;
8538 }
8539
8540 em->start = cur_offset;
8541 em->orig_start = cur_offset;
8542 em->len = ins.offset;
8543 em->block_start = ins.objectid;
8544 em->block_len = ins.offset;
8545 em->orig_block_len = ins.offset;
8546 em->ram_bytes = ins.offset;
8547 em->bdev = root->fs_info->fs_devices->latest_bdev;
8548 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
8549 em->generation = trans->transid;
8550
8551 while (1) {
8552 write_lock(&em_tree->lock);
8553 ret = add_extent_mapping(em_tree, em, 1);
8554 write_unlock(&em_tree->lock);
8555 if (ret != -EEXIST)
8556 break;
8557 btrfs_drop_extent_cache(inode, cur_offset,
8558 cur_offset + ins.offset - 1,
8559 0);
8560 }
8561 free_extent_map(em);
8562 next:
8563 num_bytes -= ins.offset;
8564 cur_offset += ins.offset;
8565 *alloc_hint = ins.objectid + ins.offset;
8566
8567 inode_inc_iversion(inode);
8568 inode->i_ctime = CURRENT_TIME;
8569 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
8570 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
8571 (actual_len > inode->i_size) &&
8572 (cur_offset > inode->i_size)) {
8573 if (cur_offset > actual_len)
8574 i_size = actual_len;
8575 else
8576 i_size = cur_offset;
8577 i_size_write(inode, i_size);
8578 btrfs_ordered_update_i_size(inode, i_size, NULL);
8579 }
8580
8581 ret = btrfs_update_inode(trans, root, inode);
8582
8583 if (ret) {
8584 btrfs_abort_transaction(trans, root, ret);
8585 if (own_trans)
8586 btrfs_end_transaction(trans, root);
8587 break;
8588 }
8589
8590 if (own_trans)
8591 btrfs_end_transaction(trans, root);
8592 }
8593 return ret;
8594 }
8595
8596 int btrfs_prealloc_file_range(struct inode *inode, int mode,
8597 u64 start, u64 num_bytes, u64 min_size,
8598 loff_t actual_len, u64 *alloc_hint)
8599 {
8600 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
8601 min_size, actual_len, alloc_hint,
8602 NULL);
8603 }
8604
8605 int btrfs_prealloc_file_range_trans(struct inode *inode,
8606 struct btrfs_trans_handle *trans, int mode,
8607 u64 start, u64 num_bytes, u64 min_size,
8608 loff_t actual_len, u64 *alloc_hint)
8609 {
8610 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
8611 min_size, actual_len, alloc_hint, trans);
8612 }
8613
8614 static int btrfs_set_page_dirty(struct page *page)
8615 {
8616 return __set_page_dirty_nobuffers(page);
8617 }
8618
8619 static int btrfs_permission(struct inode *inode, int mask)
8620 {
8621 struct btrfs_root *root = BTRFS_I(inode)->root;
8622 umode_t mode = inode->i_mode;
8623
8624 if (mask & MAY_WRITE &&
8625 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
8626 if (btrfs_root_readonly(root))
8627 return -EROFS;
8628 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
8629 return -EACCES;
8630 }
8631 return generic_permission(inode, mask);
8632 }
8633
8634 static const struct inode_operations btrfs_dir_inode_operations = {
8635 .getattr = btrfs_getattr,
8636 .lookup = btrfs_lookup,
8637 .create = btrfs_create,
8638 .unlink = btrfs_unlink,
8639 .link = btrfs_link,
8640 .mkdir = btrfs_mkdir,
8641 .rmdir = btrfs_rmdir,
8642 .rename = btrfs_rename,
8643 .symlink = btrfs_symlink,
8644 .setattr = btrfs_setattr,
8645 .mknod = btrfs_mknod,
8646 .setxattr = btrfs_setxattr,
8647 .getxattr = btrfs_getxattr,
8648 .listxattr = btrfs_listxattr,
8649 .removexattr = btrfs_removexattr,
8650 .permission = btrfs_permission,
8651 .get_acl = btrfs_get_acl,
8652 .update_time = btrfs_update_time,
8653 };
8654 static const struct inode_operations btrfs_dir_ro_inode_operations = {
8655 .lookup = btrfs_lookup,
8656 .permission = btrfs_permission,
8657 .get_acl = btrfs_get_acl,
8658 .update_time = btrfs_update_time,
8659 };
8660
8661 static const struct file_operations btrfs_dir_file_operations = {
8662 .llseek = generic_file_llseek,
8663 .read = generic_read_dir,
8664 .iterate = btrfs_real_readdir,
8665 .unlocked_ioctl = btrfs_ioctl,
8666 #ifdef CONFIG_COMPAT
8667 .compat_ioctl = btrfs_ioctl,
8668 #endif
8669 .release = btrfs_release_file,
8670 .fsync = btrfs_sync_file,
8671 };
8672
8673 static struct extent_io_ops btrfs_extent_io_ops = {
8674 .fill_delalloc = run_delalloc_range,
8675 .submit_bio_hook = btrfs_submit_bio_hook,
8676 .merge_bio_hook = btrfs_merge_bio_hook,
8677 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
8678 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
8679 .writepage_start_hook = btrfs_writepage_start_hook,
8680 .set_bit_hook = btrfs_set_bit_hook,
8681 .clear_bit_hook = btrfs_clear_bit_hook,
8682 .merge_extent_hook = btrfs_merge_extent_hook,
8683 .split_extent_hook = btrfs_split_extent_hook,
8684 };
8685
8686 /*
8687 * btrfs doesn't support the bmap operation because swapfiles
8688 * use bmap to make a mapping of extents in the file. They assume
8689 * these extents won't change over the life of the file and they
8690 * use the bmap result to do IO directly to the drive.
8691 *
8692 * the btrfs bmap call would return logical addresses that aren't
8693 * suitable for IO and they also will change frequently as COW
8694 * operations happen. So, swapfile + btrfs == corruption.
8695 *
8696 * For now we're avoiding this by dropping bmap.
8697 */
8698 static const struct address_space_operations btrfs_aops = {
8699 .readpage = btrfs_readpage,
8700 .writepage = btrfs_writepage,
8701 .writepages = btrfs_writepages,
8702 .readpages = btrfs_readpages,
8703 .direct_IO = btrfs_direct_IO,
8704 .invalidatepage = btrfs_invalidatepage,
8705 .releasepage = btrfs_releasepage,
8706 .set_page_dirty = btrfs_set_page_dirty,
8707 .error_remove_page = generic_error_remove_page,
8708 };
8709
8710 static const struct address_space_operations btrfs_symlink_aops = {
8711 .readpage = btrfs_readpage,
8712 .writepage = btrfs_writepage,
8713 .invalidatepage = btrfs_invalidatepage,
8714 .releasepage = btrfs_releasepage,
8715 };
8716
8717 static const struct inode_operations btrfs_file_inode_operations = {
8718 .getattr = btrfs_getattr,
8719 .setattr = btrfs_setattr,
8720 .setxattr = btrfs_setxattr,
8721 .getxattr = btrfs_getxattr,
8722 .listxattr = btrfs_listxattr,
8723 .removexattr = btrfs_removexattr,
8724 .permission = btrfs_permission,
8725 .fiemap = btrfs_fiemap,
8726 .get_acl = btrfs_get_acl,
8727 .update_time = btrfs_update_time,
8728 };
8729 static const struct inode_operations btrfs_special_inode_operations = {
8730 .getattr = btrfs_getattr,
8731 .setattr = btrfs_setattr,
8732 .permission = btrfs_permission,
8733 .setxattr = btrfs_setxattr,
8734 .getxattr = btrfs_getxattr,
8735 .listxattr = btrfs_listxattr,
8736 .removexattr = btrfs_removexattr,
8737 .get_acl = btrfs_get_acl,
8738 .update_time = btrfs_update_time,
8739 };
8740 static const struct inode_operations btrfs_symlink_inode_operations = {
8741 .readlink = generic_readlink,
8742 .follow_link = page_follow_link_light,
8743 .put_link = page_put_link,
8744 .getattr = btrfs_getattr,
8745 .setattr = btrfs_setattr,
8746 .permission = btrfs_permission,
8747 .setxattr = btrfs_setxattr,
8748 .getxattr = btrfs_getxattr,
8749 .listxattr = btrfs_listxattr,
8750 .removexattr = btrfs_removexattr,
8751 .get_acl = btrfs_get_acl,
8752 .update_time = btrfs_update_time,
8753 };
8754
8755 const struct dentry_operations btrfs_dentry_operations = {
8756 .d_delete = btrfs_dentry_delete,
8757 .d_release = btrfs_dentry_release,
8758 };
Linus' kernel tree