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Merge git://git.kernel.org/pub/scm/virt/kvm/kvm
[linux-2.6/cjktty.git] / fs / btrfs / inode.c
blob16d9e8e191e6ac34d92da08fe90b46e2de42ebf8
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/bit_spinlock.h>
36 #include <linux/xattr.h>
37 #include <linux/posix_acl.h>
38 #include <linux/falloc.h>
39 #include <linux/slab.h>
40 #include <linux/ratelimit.h>
41 #include <linux/mount.h>
42 #include "compat.h"
43 #include "ctree.h"
44 #include "disk-io.h"
45 #include "transaction.h"
46 #include "btrfs_inode.h"
47 #include "ioctl.h"
48 #include "print-tree.h"
49 #include "ordered-data.h"
50 #include "xattr.h"
51 #include "tree-log.h"
52 #include "volumes.h"
53 #include "compression.h"
54 #include "locking.h"
55 #include "free-space-cache.h"
56 #include "inode-map.h"
57
58 struct btrfs_iget_args {
59 u64 ino;
60 struct btrfs_root *root;
61 };
62
63 static const struct inode_operations btrfs_dir_inode_operations;
64 static const struct inode_operations btrfs_symlink_inode_operations;
65 static const struct inode_operations btrfs_dir_ro_inode_operations;
66 static const struct inode_operations btrfs_special_inode_operations;
67 static const struct inode_operations btrfs_file_inode_operations;
68 static const struct address_space_operations btrfs_aops;
69 static const struct address_space_operations btrfs_symlink_aops;
70 static const struct file_operations btrfs_dir_file_operations;
71 static struct extent_io_ops btrfs_extent_io_ops;
72
73 static struct kmem_cache *btrfs_inode_cachep;
74 static struct kmem_cache *btrfs_delalloc_work_cachep;
75 struct kmem_cache *btrfs_trans_handle_cachep;
76 struct kmem_cache *btrfs_transaction_cachep;
77 struct kmem_cache *btrfs_path_cachep;
78 struct kmem_cache *btrfs_free_space_cachep;
79
80 #define S_SHIFT 12
81 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
82 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
83 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
84 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
85 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
86 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
87 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
88 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
89 };
90
91 static int btrfs_setsize(struct inode *inode, loff_t newsize);
92 static int btrfs_truncate(struct inode *inode);
93 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
94 static noinline int cow_file_range(struct inode *inode,
95 struct page *locked_page,
96 u64 start, u64 end, int *page_started,
97 unsigned long *nr_written, int unlock);
98 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
99 u64 len, u64 orig_start,
100 u64 block_start, u64 block_len,
101 u64 orig_block_len, int type);
102
103 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
104 struct inode *inode, struct inode *dir,
105 const struct qstr *qstr)
106 {
107 int err;
108
109 err = btrfs_init_acl(trans, inode, dir);
110 if (!err)
111 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
112 return err;
113 }
114
115 /*
116 * this does all the hard work for inserting an inline extent into
117 * the btree. The caller should have done a btrfs_drop_extents so that
118 * no overlapping inline items exist in the btree
119 */
120 static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
121 struct btrfs_root *root, struct inode *inode,
122 u64 start, size_t size, size_t compressed_size,
123 int compress_type,
124 struct page **compressed_pages)
125 {
126 struct btrfs_key key;
127 struct btrfs_path *path;
128 struct extent_buffer *leaf;
129 struct page *page = NULL;
130 char *kaddr;
131 unsigned long ptr;
132 struct btrfs_file_extent_item *ei;
133 int err = 0;
134 int ret;
135 size_t cur_size = size;
136 size_t datasize;
137 unsigned long offset;
138
139 if (compressed_size && compressed_pages)
140 cur_size = compressed_size;
141
142 path = btrfs_alloc_path();
143 if (!path)
144 return -ENOMEM;
145
146 path->leave_spinning = 1;
147
148 key.objectid = btrfs_ino(inode);
149 key.offset = start;
150 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
151 datasize = btrfs_file_extent_calc_inline_size(cur_size);
152
153 inode_add_bytes(inode, size);
154 ret = btrfs_insert_empty_item(trans, root, path, &key,
155 datasize);
156 if (ret) {
157 err = ret;
158 goto fail;
159 }
160 leaf = path->nodes[0];
161 ei = btrfs_item_ptr(leaf, path->slots[0],
162 struct btrfs_file_extent_item);
163 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
164 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
165 btrfs_set_file_extent_encryption(leaf, ei, 0);
166 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
167 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
168 ptr = btrfs_file_extent_inline_start(ei);
169
170 if (compress_type != BTRFS_COMPRESS_NONE) {
171 struct page *cpage;
172 int i = 0;
173 while (compressed_size > 0) {
174 cpage = compressed_pages[i];
175 cur_size = min_t(unsigned long, compressed_size,
176 PAGE_CACHE_SIZE);
177
178 kaddr = kmap_atomic(cpage);
179 write_extent_buffer(leaf, kaddr, ptr, cur_size);
180 kunmap_atomic(kaddr);
181
182 i++;
183 ptr += cur_size;
184 compressed_size -= cur_size;
185 }
186 btrfs_set_file_extent_compression(leaf, ei,
187 compress_type);
188 } else {
189 page = find_get_page(inode->i_mapping,
190 start >> PAGE_CACHE_SHIFT);
191 btrfs_set_file_extent_compression(leaf, ei, 0);
192 kaddr = kmap_atomic(page);
193 offset = start & (PAGE_CACHE_SIZE - 1);
194 write_extent_buffer(leaf, kaddr + offset, ptr, size);
195 kunmap_atomic(kaddr);
196 page_cache_release(page);
197 }
198 btrfs_mark_buffer_dirty(leaf);
199 btrfs_free_path(path);
200
201 /*
202 * we're an inline extent, so nobody can
203 * extend the file past i_size without locking
204 * a page we already have locked.
205 *
206 * We must do any isize and inode updates
207 * before we unlock the pages. Otherwise we
208 * could end up racing with unlink.
209 */
210 BTRFS_I(inode)->disk_i_size = inode->i_size;
211 ret = btrfs_update_inode(trans, root, inode);
212
213 return ret;
214 fail:
215 btrfs_free_path(path);
216 return err;
217 }
218
219
220 /*
221 * conditionally insert an inline extent into the file. This
222 * does the checks required to make sure the data is small enough
223 * to fit as an inline extent.
224 */
225 static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans,
226 struct btrfs_root *root,
227 struct inode *inode, u64 start, u64 end,
228 size_t compressed_size, int compress_type,
229 struct page **compressed_pages)
230 {
231 u64 isize = i_size_read(inode);
232 u64 actual_end = min(end + 1, isize);
233 u64 inline_len = actual_end - start;
234 u64 aligned_end = (end + root->sectorsize - 1) &
235 ~((u64)root->sectorsize - 1);
236 u64 data_len = inline_len;
237 int ret;
238
239 if (compressed_size)
240 data_len = compressed_size;
241
242 if (start > 0 ||
243 actual_end >= PAGE_CACHE_SIZE ||
244 data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
245 (!compressed_size &&
246 (actual_end & (root->sectorsize - 1)) == 0) ||
247 end + 1 < isize ||
248 data_len > root->fs_info->max_inline) {
249 return 1;
250 }
251
252 ret = btrfs_drop_extents(trans, root, inode, start, aligned_end, 1);
253 if (ret)
254 return ret;
255
256 if (isize > actual_end)
257 inline_len = min_t(u64, isize, actual_end);
258 ret = insert_inline_extent(trans, root, inode, start,
259 inline_len, compressed_size,
260 compress_type, compressed_pages);
261 if (ret && ret != -ENOSPC) {
262 btrfs_abort_transaction(trans, root, ret);
263 return ret;
264 } else if (ret == -ENOSPC) {
265 return 1;
266 }
267
268 btrfs_delalloc_release_metadata(inode, end + 1 - start);
269 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
270 return 0;
271 }
272
273 struct async_extent {
274 u64 start;
275 u64 ram_size;
276 u64 compressed_size;
277 struct page **pages;
278 unsigned long nr_pages;
279 int compress_type;
280 struct list_head list;
281 };
282
283 struct async_cow {
284 struct inode *inode;
285 struct btrfs_root *root;
286 struct page *locked_page;
287 u64 start;
288 u64 end;
289 struct list_head extents;
290 struct btrfs_work work;
291 };
292
293 static noinline int add_async_extent(struct async_cow *cow,
294 u64 start, u64 ram_size,
295 u64 compressed_size,
296 struct page **pages,
297 unsigned long nr_pages,
298 int compress_type)
299 {
300 struct async_extent *async_extent;
301
302 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
303 BUG_ON(!async_extent); /* -ENOMEM */
304 async_extent->start = start;
305 async_extent->ram_size = ram_size;
306 async_extent->compressed_size = compressed_size;
307 async_extent->pages = pages;
308 async_extent->nr_pages = nr_pages;
309 async_extent->compress_type = compress_type;
310 list_add_tail(&async_extent->list, &cow->extents);
311 return 0;
312 }
313
314 /*
315 * we create compressed extents in two phases. The first
316 * phase compresses a range of pages that have already been
317 * locked (both pages and state bits are locked).
318 *
319 * This is done inside an ordered work queue, and the compression
320 * is spread across many cpus. The actual IO submission is step
321 * two, and the ordered work queue takes care of making sure that
322 * happens in the same order things were put onto the queue by
323 * writepages and friends.
324 *
325 * If this code finds it can't get good compression, it puts an
326 * entry onto the work queue to write the uncompressed bytes. This
327 * makes sure that both compressed inodes and uncompressed inodes
328 * are written in the same order that the flusher thread sent them
329 * down.
330 */
331 static noinline int compress_file_range(struct inode *inode,
332 struct page *locked_page,
333 u64 start, u64 end,
334 struct async_cow *async_cow,
335 int *num_added)
336 {
337 struct btrfs_root *root = BTRFS_I(inode)->root;
338 struct btrfs_trans_handle *trans;
339 u64 num_bytes;
340 u64 blocksize = root->sectorsize;
341 u64 actual_end;
342 u64 isize = i_size_read(inode);
343 int ret = 0;
344 struct page **pages = NULL;
345 unsigned long nr_pages;
346 unsigned long nr_pages_ret = 0;
347 unsigned long total_compressed = 0;
348 unsigned long total_in = 0;
349 unsigned long max_compressed = 128 * 1024;
350 unsigned long max_uncompressed = 128 * 1024;
351 int i;
352 int will_compress;
353 int compress_type = root->fs_info->compress_type;
354
355 /* if this is a small write inside eof, kick off a defrag */
356 if ((end - start + 1) < 16 * 1024 &&
357 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
358 btrfs_add_inode_defrag(NULL, inode);
359
360 actual_end = min_t(u64, isize, end + 1);
361 again:
362 will_compress = 0;
363 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
364 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
365
366 /*
367 * we don't want to send crud past the end of i_size through
368 * compression, that's just a waste of CPU time. So, if the
369 * end of the file is before the start of our current
370 * requested range of bytes, we bail out to the uncompressed
371 * cleanup code that can deal with all of this.
372 *
373 * It isn't really the fastest way to fix things, but this is a
374 * very uncommon corner.
375 */
376 if (actual_end <= start)
377 goto cleanup_and_bail_uncompressed;
378
379 total_compressed = actual_end - start;
380
381 /* we want to make sure that amount of ram required to uncompress
382 * an extent is reasonable, so we limit the total size in ram
383 * of a compressed extent to 128k. This is a crucial number
384 * because it also controls how easily we can spread reads across
385 * cpus for decompression.
386 *
387 * We also want to make sure the amount of IO required to do
388 * a random read is reasonably small, so we limit the size of
389 * a compressed extent to 128k.
390 */
391 total_compressed = min(total_compressed, max_uncompressed);
392 num_bytes = (end - start + blocksize) & ~(blocksize - 1);
393 num_bytes = max(blocksize, num_bytes);
394 total_in = 0;
395 ret = 0;
396
397 /*
398 * we do compression for mount -o compress and when the
399 * inode has not been flagged as nocompress. This flag can
400 * change at any time if we discover bad compression ratios.
401 */
402 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) &&
403 (btrfs_test_opt(root, COMPRESS) ||
404 (BTRFS_I(inode)->force_compress) ||
405 (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) {
406 WARN_ON(pages);
407 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
408 if (!pages) {
409 /* just bail out to the uncompressed code */
410 goto cont;
411 }
412
413 if (BTRFS_I(inode)->force_compress)
414 compress_type = BTRFS_I(inode)->force_compress;
415
416 ret = btrfs_compress_pages(compress_type,
417 inode->i_mapping, start,
418 total_compressed, pages,
419 nr_pages, &nr_pages_ret,
420 &total_in,
421 &total_compressed,
422 max_compressed);
423
424 if (!ret) {
425 unsigned long offset = total_compressed &
426 (PAGE_CACHE_SIZE - 1);
427 struct page *page = pages[nr_pages_ret - 1];
428 char *kaddr;
429
430 /* zero the tail end of the last page, we might be
431 * sending it down to disk
432 */
433 if (offset) {
434 kaddr = kmap_atomic(page);
435 memset(kaddr + offset, 0,
436 PAGE_CACHE_SIZE - offset);
437 kunmap_atomic(kaddr);
438 }
439 will_compress = 1;
440 }
441 }
442 cont:
443 if (start == 0) {
444 trans = btrfs_join_transaction(root);
445 if (IS_ERR(trans)) {
446 ret = PTR_ERR(trans);
447 trans = NULL;
448 goto cleanup_and_out;
449 }
450 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
451
452 /* lets try to make an inline extent */
453 if (ret || total_in < (actual_end - start)) {
454 /* we didn't compress the entire range, try
455 * to make an uncompressed inline extent.
456 */
457 ret = cow_file_range_inline(trans, root, inode,
458 start, end, 0, 0, NULL);
459 } else {
460 /* try making a compressed inline extent */
461 ret = cow_file_range_inline(trans, root, inode,
462 start, end,
463 total_compressed,
464 compress_type, pages);
465 }
466 if (ret <= 0) {
467 /*
468 * inline extent creation worked or returned error,
469 * we don't need to create any more async work items.
470 * Unlock and free up our temp pages.
471 */
472 extent_clear_unlock_delalloc(inode,
473 &BTRFS_I(inode)->io_tree,
474 start, end, NULL,
475 EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
476 EXTENT_CLEAR_DELALLOC |
477 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK);
478
479 btrfs_end_transaction(trans, root);
480 goto free_pages_out;
481 }
482 btrfs_end_transaction(trans, root);
483 }
484
485 if (will_compress) {
486 /*
487 * we aren't doing an inline extent round the compressed size
488 * up to a block size boundary so the allocator does sane
489 * things
490 */
491 total_compressed = (total_compressed + blocksize - 1) &
492 ~(blocksize - 1);
493
494 /*
495 * one last check to make sure the compression is really a
496 * win, compare the page count read with the blocks on disk
497 */
498 total_in = (total_in + PAGE_CACHE_SIZE - 1) &
499 ~(PAGE_CACHE_SIZE - 1);
500 if (total_compressed >= total_in) {
501 will_compress = 0;
502 } else {
503 num_bytes = total_in;
504 }
505 }
506 if (!will_compress && pages) {
507 /*
508 * the compression code ran but failed to make things smaller,
509 * free any pages it allocated and our page pointer array
510 */
511 for (i = 0; i < nr_pages_ret; i++) {
512 WARN_ON(pages[i]->mapping);
513 page_cache_release(pages[i]);
514 }
515 kfree(pages);
516 pages = NULL;
517 total_compressed = 0;
518 nr_pages_ret = 0;
519
520 /* flag the file so we don't compress in the future */
521 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
522 !(BTRFS_I(inode)->force_compress)) {
523 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
524 }
525 }
526 if (will_compress) {
527 *num_added += 1;
528
529 /* the async work queues will take care of doing actual
530 * allocation on disk for these compressed pages,
531 * and will submit them to the elevator.
532 */
533 add_async_extent(async_cow, start, num_bytes,
534 total_compressed, pages, nr_pages_ret,
535 compress_type);
536
537 if (start + num_bytes < end) {
538 start += num_bytes;
539 pages = NULL;
540 cond_resched();
541 goto again;
542 }
543 } else {
544 cleanup_and_bail_uncompressed:
545 /*
546 * No compression, but we still need to write the pages in
547 * the file we've been given so far. redirty the locked
548 * page if it corresponds to our extent and set things up
549 * for the async work queue to run cow_file_range to do
550 * the normal delalloc dance
551 */
552 if (page_offset(locked_page) >= start &&
553 page_offset(locked_page) <= end) {
554 __set_page_dirty_nobuffers(locked_page);
555 /* unlocked later on in the async handlers */
556 }
557 add_async_extent(async_cow, start, end - start + 1,
558 0, NULL, 0, BTRFS_COMPRESS_NONE);
559 *num_added += 1;
560 }
561
562 out:
563 return ret;
564
565 free_pages_out:
566 for (i = 0; i < nr_pages_ret; i++) {
567 WARN_ON(pages[i]->mapping);
568 page_cache_release(pages[i]);
569 }
570 kfree(pages);
571
572 goto out;
573
574 cleanup_and_out:
575 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
576 start, end, NULL,
577 EXTENT_CLEAR_UNLOCK_PAGE |
578 EXTENT_CLEAR_DIRTY |
579 EXTENT_CLEAR_DELALLOC |
580 EXTENT_SET_WRITEBACK |
581 EXTENT_END_WRITEBACK);
582 if (!trans || IS_ERR(trans))
583 btrfs_error(root->fs_info, ret, "Failed to join transaction");
584 else
585 btrfs_abort_transaction(trans, root, ret);
586 goto free_pages_out;
587 }
588
589 /*
590 * phase two of compressed writeback. This is the ordered portion
591 * of the code, which only gets called in the order the work was
592 * queued. We walk all the async extents created by compress_file_range
593 * and send them down to the disk.
594 */
595 static noinline int submit_compressed_extents(struct inode *inode,
596 struct async_cow *async_cow)
597 {
598 struct async_extent *async_extent;
599 u64 alloc_hint = 0;
600 struct btrfs_trans_handle *trans;
601 struct btrfs_key ins;
602 struct extent_map *em;
603 struct btrfs_root *root = BTRFS_I(inode)->root;
604 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
605 struct extent_io_tree *io_tree;
606 int ret = 0;
607
608 if (list_empty(&async_cow->extents))
609 return 0;
610
611
612 while (!list_empty(&async_cow->extents)) {
613 async_extent = list_entry(async_cow->extents.next,
614 struct async_extent, list);
615 list_del(&async_extent->list);
616
617 io_tree = &BTRFS_I(inode)->io_tree;
618
619 retry:
620 /* did the compression code fall back to uncompressed IO? */
621 if (!async_extent->pages) {
622 int page_started = 0;
623 unsigned long nr_written = 0;
624
625 lock_extent(io_tree, async_extent->start,
626 async_extent->start +
627 async_extent->ram_size - 1);
628
629 /* allocate blocks */
630 ret = cow_file_range(inode, async_cow->locked_page,
631 async_extent->start,
632 async_extent->start +
633 async_extent->ram_size - 1,
634 &page_started, &nr_written, 0);
635
636 /* JDM XXX */
637
638 /*
639 * if page_started, cow_file_range inserted an
640 * inline extent and took care of all the unlocking
641 * and IO for us. Otherwise, we need to submit
642 * all those pages down to the drive.
643 */
644 if (!page_started && !ret)
645 extent_write_locked_range(io_tree,
646 inode, async_extent->start,
647 async_extent->start +
648 async_extent->ram_size - 1,
649 btrfs_get_extent,
650 WB_SYNC_ALL);
651 kfree(async_extent);
652 cond_resched();
653 continue;
654 }
655
656 lock_extent(io_tree, async_extent->start,
657 async_extent->start + async_extent->ram_size - 1);
658
659 trans = btrfs_join_transaction(root);
660 if (IS_ERR(trans)) {
661 ret = PTR_ERR(trans);
662 } else {
663 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
664 ret = btrfs_reserve_extent(trans, root,
665 async_extent->compressed_size,
666 async_extent->compressed_size,
667 0, alloc_hint, &ins, 1);
668 if (ret && ret != -ENOSPC)
669 btrfs_abort_transaction(trans, root, ret);
670 btrfs_end_transaction(trans, root);
671 }
672
673 if (ret) {
674 int i;
675 for (i = 0; i < async_extent->nr_pages; i++) {
676 WARN_ON(async_extent->pages[i]->mapping);
677 page_cache_release(async_extent->pages[i]);
678 }
679 kfree(async_extent->pages);
680 async_extent->nr_pages = 0;
681 async_extent->pages = NULL;
682 unlock_extent(io_tree, async_extent->start,
683 async_extent->start +
684 async_extent->ram_size - 1);
685 if (ret == -ENOSPC)
686 goto retry;
687 goto out_free; /* JDM: Requeue? */
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 BUG_ON(!em); /* -ENOMEM */
700 em->start = async_extent->start;
701 em->len = async_extent->ram_size;
702 em->orig_start = em->start;
703
704 em->block_start = ins.objectid;
705 em->block_len = ins.offset;
706 em->orig_block_len = ins.offset;
707 em->bdev = root->fs_info->fs_devices->latest_bdev;
708 em->compress_type = async_extent->compress_type;
709 set_bit(EXTENT_FLAG_PINNED, &em->flags);
710 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
711 em->generation = -1;
712
713 while (1) {
714 write_lock(&em_tree->lock);
715 ret = add_extent_mapping(em_tree, em);
716 if (!ret)
717 list_move(&em->list,
718 &em_tree->modified_extents);
719 write_unlock(&em_tree->lock);
720 if (ret != -EEXIST) {
721 free_extent_map(em);
722 break;
723 }
724 btrfs_drop_extent_cache(inode, async_extent->start,
725 async_extent->start +
726 async_extent->ram_size - 1, 0);
727 }
728
729 ret = btrfs_add_ordered_extent_compress(inode,
730 async_extent->start,
731 ins.objectid,
732 async_extent->ram_size,
733 ins.offset,
734 BTRFS_ORDERED_COMPRESSED,
735 async_extent->compress_type);
736 BUG_ON(ret); /* -ENOMEM */
737
738 /*
739 * clear dirty, set writeback and unlock the pages.
740 */
741 extent_clear_unlock_delalloc(inode,
742 &BTRFS_I(inode)->io_tree,
743 async_extent->start,
744 async_extent->start +
745 async_extent->ram_size - 1,
746 NULL, EXTENT_CLEAR_UNLOCK_PAGE |
747 EXTENT_CLEAR_UNLOCK |
748 EXTENT_CLEAR_DELALLOC |
749 EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK);
750
751 ret = btrfs_submit_compressed_write(inode,
752 async_extent->start,
753 async_extent->ram_size,
754 ins.objectid,
755 ins.offset, async_extent->pages,
756 async_extent->nr_pages);
757
758 BUG_ON(ret); /* -ENOMEM */
759 alloc_hint = ins.objectid + ins.offset;
760 kfree(async_extent);
761 cond_resched();
762 }
763 ret = 0;
764 out:
765 return ret;
766 out_free:
767 kfree(async_extent);
768 goto out;
769 }
770
771 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
772 u64 num_bytes)
773 {
774 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
775 struct extent_map *em;
776 u64 alloc_hint = 0;
777
778 read_lock(&em_tree->lock);
779 em = search_extent_mapping(em_tree, start, num_bytes);
780 if (em) {
781 /*
782 * if block start isn't an actual block number then find the
783 * first block in this inode and use that as a hint. If that
784 * block is also bogus then just don't worry about it.
785 */
786 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
787 free_extent_map(em);
788 em = search_extent_mapping(em_tree, 0, 0);
789 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
790 alloc_hint = em->block_start;
791 if (em)
792 free_extent_map(em);
793 } else {
794 alloc_hint = em->block_start;
795 free_extent_map(em);
796 }
797 }
798 read_unlock(&em_tree->lock);
799
800 return alloc_hint;
801 }
802
803 /*
804 * when extent_io.c finds a delayed allocation range in the file,
805 * the call backs end up in this code. The basic idea is to
806 * allocate extents on disk for the range, and create ordered data structs
807 * in ram to track those extents.
808 *
809 * locked_page is the page that writepage had locked already. We use
810 * it to make sure we don't do extra locks or unlocks.
811 *
812 * *page_started is set to one if we unlock locked_page and do everything
813 * required to start IO on it. It may be clean and already done with
814 * IO when we return.
815 */
816 static noinline int __cow_file_range(struct btrfs_trans_handle *trans,
817 struct inode *inode,
818 struct btrfs_root *root,
819 struct page *locked_page,
820 u64 start, u64 end, int *page_started,
821 unsigned long *nr_written,
822 int unlock)
823 {
824 u64 alloc_hint = 0;
825 u64 num_bytes;
826 unsigned long ram_size;
827 u64 disk_num_bytes;
828 u64 cur_alloc_size;
829 u64 blocksize = root->sectorsize;
830 struct btrfs_key ins;
831 struct extent_map *em;
832 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
833 int ret = 0;
834
835 BUG_ON(btrfs_is_free_space_inode(inode));
836
837 num_bytes = (end - start + blocksize) & ~(blocksize - 1);
838 num_bytes = max(blocksize, num_bytes);
839 disk_num_bytes = num_bytes;
840
841 /* if this is a small write inside eof, kick off defrag */
842 if (num_bytes < 64 * 1024 &&
843 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
844 btrfs_add_inode_defrag(trans, inode);
845
846 if (start == 0) {
847 /* lets try to make an inline extent */
848 ret = cow_file_range_inline(trans, root, inode,
849 start, end, 0, 0, NULL);
850 if (ret == 0) {
851 extent_clear_unlock_delalloc(inode,
852 &BTRFS_I(inode)->io_tree,
853 start, end, NULL,
854 EXTENT_CLEAR_UNLOCK_PAGE |
855 EXTENT_CLEAR_UNLOCK |
856 EXTENT_CLEAR_DELALLOC |
857 EXTENT_CLEAR_DIRTY |
858 EXTENT_SET_WRITEBACK |
859 EXTENT_END_WRITEBACK);
860
861 *nr_written = *nr_written +
862 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
863 *page_started = 1;
864 goto out;
865 } else if (ret < 0) {
866 btrfs_abort_transaction(trans, root, ret);
867 goto out_unlock;
868 }
869 }
870
871 BUG_ON(disk_num_bytes >
872 btrfs_super_total_bytes(root->fs_info->super_copy));
873
874 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
875 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
876
877 while (disk_num_bytes > 0) {
878 unsigned long op;
879
880 cur_alloc_size = disk_num_bytes;
881 ret = btrfs_reserve_extent(trans, root, cur_alloc_size,
882 root->sectorsize, 0, alloc_hint,
883 &ins, 1);
884 if (ret < 0) {
885 btrfs_abort_transaction(trans, root, ret);
886 goto out_unlock;
887 }
888
889 em = alloc_extent_map();
890 BUG_ON(!em); /* -ENOMEM */
891 em->start = start;
892 em->orig_start = em->start;
893 ram_size = ins.offset;
894 em->len = ins.offset;
895
896 em->block_start = ins.objectid;
897 em->block_len = ins.offset;
898 em->orig_block_len = ins.offset;
899 em->bdev = root->fs_info->fs_devices->latest_bdev;
900 set_bit(EXTENT_FLAG_PINNED, &em->flags);
901 em->generation = -1;
902
903 while (1) {
904 write_lock(&em_tree->lock);
905 ret = add_extent_mapping(em_tree, em);
906 if (!ret)
907 list_move(&em->list,
908 &em_tree->modified_extents);
909 write_unlock(&em_tree->lock);
910 if (ret != -EEXIST) {
911 free_extent_map(em);
912 break;
913 }
914 btrfs_drop_extent_cache(inode, start,
915 start + ram_size - 1, 0);
916 }
917
918 cur_alloc_size = ins.offset;
919 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
920 ram_size, cur_alloc_size, 0);
921 BUG_ON(ret); /* -ENOMEM */
922
923 if (root->root_key.objectid ==
924 BTRFS_DATA_RELOC_TREE_OBJECTID) {
925 ret = btrfs_reloc_clone_csums(inode, start,
926 cur_alloc_size);
927 if (ret) {
928 btrfs_abort_transaction(trans, root, ret);
929 goto out_unlock;
930 }
931 }
932
933 if (disk_num_bytes < cur_alloc_size)
934 break;
935
936 /* we're not doing compressed IO, don't unlock the first
937 * page (which the caller expects to stay locked), don't
938 * clear any dirty bits and don't set any writeback bits
939 *
940 * Do set the Private2 bit so we know this page was properly
941 * setup for writepage
942 */
943 op = unlock ? EXTENT_CLEAR_UNLOCK_PAGE : 0;
944 op |= EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
945 EXTENT_SET_PRIVATE2;
946
947 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
948 start, start + ram_size - 1,
949 locked_page, op);
950 disk_num_bytes -= cur_alloc_size;
951 num_bytes -= cur_alloc_size;
952 alloc_hint = ins.objectid + ins.offset;
953 start += cur_alloc_size;
954 }
955 out:
956 return ret;
957
958 out_unlock:
959 extent_clear_unlock_delalloc(inode,
960 &BTRFS_I(inode)->io_tree,
961 start, end, locked_page,
962 EXTENT_CLEAR_UNLOCK_PAGE |
963 EXTENT_CLEAR_UNLOCK |
964 EXTENT_CLEAR_DELALLOC |
965 EXTENT_CLEAR_DIRTY |
966 EXTENT_SET_WRITEBACK |
967 EXTENT_END_WRITEBACK);
968
969 goto out;
970 }
971
972 static noinline int cow_file_range(struct inode *inode,
973 struct page *locked_page,
974 u64 start, u64 end, int *page_started,
975 unsigned long *nr_written,
976 int unlock)
977 {
978 struct btrfs_trans_handle *trans;
979 struct btrfs_root *root = BTRFS_I(inode)->root;
980 int ret;
981
982 trans = btrfs_join_transaction(root);
983 if (IS_ERR(trans)) {
984 extent_clear_unlock_delalloc(inode,
985 &BTRFS_I(inode)->io_tree,
986 start, end, locked_page,
987 EXTENT_CLEAR_UNLOCK_PAGE |
988 EXTENT_CLEAR_UNLOCK |
989 EXTENT_CLEAR_DELALLOC |
990 EXTENT_CLEAR_DIRTY |
991 EXTENT_SET_WRITEBACK |
992 EXTENT_END_WRITEBACK);
993 return PTR_ERR(trans);
994 }
995 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
996
997 ret = __cow_file_range(trans, inode, root, locked_page, start, end,
998 page_started, nr_written, unlock);
999
1000 btrfs_end_transaction(trans, root);
1001
1002 return ret;
1003 }
1004
1005 /*
1006 * work queue call back to started compression on a file and pages
1007 */
1008 static noinline void async_cow_start(struct btrfs_work *work)
1009 {
1010 struct async_cow *async_cow;
1011 int num_added = 0;
1012 async_cow = container_of(work, struct async_cow, work);
1013
1014 compress_file_range(async_cow->inode, async_cow->locked_page,
1015 async_cow->start, async_cow->end, async_cow,
1016 &num_added);
1017 if (num_added == 0) {
1018 btrfs_add_delayed_iput(async_cow->inode);
1019 async_cow->inode = NULL;
1020 }
1021 }
1022
1023 /*
1024 * work queue call back to submit previously compressed pages
1025 */
1026 static noinline void async_cow_submit(struct btrfs_work *work)
1027 {
1028 struct async_cow *async_cow;
1029 struct btrfs_root *root;
1030 unsigned long nr_pages;
1031
1032 async_cow = container_of(work, struct async_cow, work);
1033
1034 root = async_cow->root;
1035 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
1036 PAGE_CACHE_SHIFT;
1037
1038 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1039 5 * 1024 * 1024 &&
1040 waitqueue_active(&root->fs_info->async_submit_wait))
1041 wake_up(&root->fs_info->async_submit_wait);
1042
1043 if (async_cow->inode)
1044 submit_compressed_extents(async_cow->inode, async_cow);
1045 }
1046
1047 static noinline void async_cow_free(struct btrfs_work *work)
1048 {
1049 struct async_cow *async_cow;
1050 async_cow = container_of(work, struct async_cow, work);
1051 if (async_cow->inode)
1052 btrfs_add_delayed_iput(async_cow->inode);
1053 kfree(async_cow);
1054 }
1055
1056 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1057 u64 start, u64 end, int *page_started,
1058 unsigned long *nr_written)
1059 {
1060 struct async_cow *async_cow;
1061 struct btrfs_root *root = BTRFS_I(inode)->root;
1062 unsigned long nr_pages;
1063 u64 cur_end;
1064 int limit = 10 * 1024 * 1024;
1065
1066 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1067 1, 0, NULL, GFP_NOFS);
1068 while (start < end) {
1069 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1070 BUG_ON(!async_cow); /* -ENOMEM */
1071 async_cow->inode = igrab(inode);
1072 async_cow->root = root;
1073 async_cow->locked_page = locked_page;
1074 async_cow->start = start;
1075
1076 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
1077 cur_end = end;
1078 else
1079 cur_end = min(end, start + 512 * 1024 - 1);
1080
1081 async_cow->end = cur_end;
1082 INIT_LIST_HEAD(&async_cow->extents);
1083
1084 async_cow->work.func = async_cow_start;
1085 async_cow->work.ordered_func = async_cow_submit;
1086 async_cow->work.ordered_free = async_cow_free;
1087 async_cow->work.flags = 0;
1088
1089 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
1090 PAGE_CACHE_SHIFT;
1091 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1092
1093 btrfs_queue_worker(&root->fs_info->delalloc_workers,
1094 &async_cow->work);
1095
1096 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1097 wait_event(root->fs_info->async_submit_wait,
1098 (atomic_read(&root->fs_info->async_delalloc_pages) <
1099 limit));
1100 }
1101
1102 while (atomic_read(&root->fs_info->async_submit_draining) &&
1103 atomic_read(&root->fs_info->async_delalloc_pages)) {
1104 wait_event(root->fs_info->async_submit_wait,
1105 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1106 0));
1107 }
1108
1109 *nr_written += nr_pages;
1110 start = cur_end + 1;
1111 }
1112 *page_started = 1;
1113 return 0;
1114 }
1115
1116 static noinline int csum_exist_in_range(struct btrfs_root *root,
1117 u64 bytenr, u64 num_bytes)
1118 {
1119 int ret;
1120 struct btrfs_ordered_sum *sums;
1121 LIST_HEAD(list);
1122
1123 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1124 bytenr + num_bytes - 1, &list, 0);
1125 if (ret == 0 && list_empty(&list))
1126 return 0;
1127
1128 while (!list_empty(&list)) {
1129 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1130 list_del(&sums->list);
1131 kfree(sums);
1132 }
1133 return 1;
1134 }
1135
1136 /*
1137 * when nowcow writeback call back. This checks for snapshots or COW copies
1138 * of the extents that exist in the file, and COWs the file as required.
1139 *
1140 * If no cow copies or snapshots exist, we write directly to the existing
1141 * blocks on disk
1142 */
1143 static noinline int run_delalloc_nocow(struct inode *inode,
1144 struct page *locked_page,
1145 u64 start, u64 end, int *page_started, int force,
1146 unsigned long *nr_written)
1147 {
1148 struct btrfs_root *root = BTRFS_I(inode)->root;
1149 struct btrfs_trans_handle *trans;
1150 struct extent_buffer *leaf;
1151 struct btrfs_path *path;
1152 struct btrfs_file_extent_item *fi;
1153 struct btrfs_key found_key;
1154 u64 cow_start;
1155 u64 cur_offset;
1156 u64 extent_end;
1157 u64 extent_offset;
1158 u64 disk_bytenr;
1159 u64 num_bytes;
1160 u64 disk_num_bytes;
1161 int extent_type;
1162 int ret, err;
1163 int type;
1164 int nocow;
1165 int check_prev = 1;
1166 bool nolock;
1167 u64 ino = btrfs_ino(inode);
1168
1169 path = btrfs_alloc_path();
1170 if (!path) {
1171 extent_clear_unlock_delalloc(inode,
1172 &BTRFS_I(inode)->io_tree,
1173 start, end, locked_page,
1174 EXTENT_CLEAR_UNLOCK_PAGE |
1175 EXTENT_CLEAR_UNLOCK |
1176 EXTENT_CLEAR_DELALLOC |
1177 EXTENT_CLEAR_DIRTY |
1178 EXTENT_SET_WRITEBACK |
1179 EXTENT_END_WRITEBACK);
1180 return -ENOMEM;
1181 }
1182
1183 nolock = btrfs_is_free_space_inode(inode);
1184
1185 if (nolock)
1186 trans = btrfs_join_transaction_nolock(root);
1187 else
1188 trans = btrfs_join_transaction(root);
1189
1190 if (IS_ERR(trans)) {
1191 extent_clear_unlock_delalloc(inode,
1192 &BTRFS_I(inode)->io_tree,
1193 start, end, locked_page,
1194 EXTENT_CLEAR_UNLOCK_PAGE |
1195 EXTENT_CLEAR_UNLOCK |
1196 EXTENT_CLEAR_DELALLOC |
1197 EXTENT_CLEAR_DIRTY |
1198 EXTENT_SET_WRITEBACK |
1199 EXTENT_END_WRITEBACK);
1200 btrfs_free_path(path);
1201 return PTR_ERR(trans);
1202 }
1203
1204 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1205
1206 cow_start = (u64)-1;
1207 cur_offset = start;
1208 while (1) {
1209 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1210 cur_offset, 0);
1211 if (ret < 0) {
1212 btrfs_abort_transaction(trans, root, ret);
1213 goto error;
1214 }
1215 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1216 leaf = path->nodes[0];
1217 btrfs_item_key_to_cpu(leaf, &found_key,
1218 path->slots[0] - 1);
1219 if (found_key.objectid == ino &&
1220 found_key.type == BTRFS_EXTENT_DATA_KEY)
1221 path->slots[0]--;
1222 }
1223 check_prev = 0;
1224 next_slot:
1225 leaf = path->nodes[0];
1226 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1227 ret = btrfs_next_leaf(root, path);
1228 if (ret < 0) {
1229 btrfs_abort_transaction(trans, root, ret);
1230 goto error;
1231 }
1232 if (ret > 0)
1233 break;
1234 leaf = path->nodes[0];
1235 }
1236
1237 nocow = 0;
1238 disk_bytenr = 0;
1239 num_bytes = 0;
1240 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1241
1242 if (found_key.objectid > ino ||
1243 found_key.type > BTRFS_EXTENT_DATA_KEY ||
1244 found_key.offset > end)
1245 break;
1246
1247 if (found_key.offset > cur_offset) {
1248 extent_end = found_key.offset;
1249 extent_type = 0;
1250 goto out_check;
1251 }
1252
1253 fi = btrfs_item_ptr(leaf, path->slots[0],
1254 struct btrfs_file_extent_item);
1255 extent_type = btrfs_file_extent_type(leaf, fi);
1256
1257 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1258 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1259 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1260 extent_offset = btrfs_file_extent_offset(leaf, fi);
1261 extent_end = found_key.offset +
1262 btrfs_file_extent_num_bytes(leaf, fi);
1263 disk_num_bytes =
1264 btrfs_file_extent_disk_num_bytes(leaf, fi);
1265 if (extent_end <= start) {
1266 path->slots[0]++;
1267 goto next_slot;
1268 }
1269 if (disk_bytenr == 0)
1270 goto out_check;
1271 if (btrfs_file_extent_compression(leaf, fi) ||
1272 btrfs_file_extent_encryption(leaf, fi) ||
1273 btrfs_file_extent_other_encoding(leaf, fi))
1274 goto out_check;
1275 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1276 goto out_check;
1277 if (btrfs_extent_readonly(root, disk_bytenr))
1278 goto out_check;
1279 if (btrfs_cross_ref_exist(trans, root, ino,
1280 found_key.offset -
1281 extent_offset, disk_bytenr))
1282 goto out_check;
1283 disk_bytenr += extent_offset;
1284 disk_bytenr += cur_offset - found_key.offset;
1285 num_bytes = min(end + 1, extent_end) - cur_offset;
1286 /*
1287 * force cow if csum exists in the range.
1288 * this ensure that csum for a given extent are
1289 * either valid or do not exist.
1290 */
1291 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1292 goto out_check;
1293 nocow = 1;
1294 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1295 extent_end = found_key.offset +
1296 btrfs_file_extent_inline_len(leaf, fi);
1297 extent_end = ALIGN(extent_end, root->sectorsize);
1298 } else {
1299 BUG_ON(1);
1300 }
1301 out_check:
1302 if (extent_end <= start) {
1303 path->slots[0]++;
1304 goto next_slot;
1305 }
1306 if (!nocow) {
1307 if (cow_start == (u64)-1)
1308 cow_start = cur_offset;
1309 cur_offset = extent_end;
1310 if (cur_offset > end)
1311 break;
1312 path->slots[0]++;
1313 goto next_slot;
1314 }
1315
1316 btrfs_release_path(path);
1317 if (cow_start != (u64)-1) {
1318 ret = __cow_file_range(trans, inode, root, locked_page,
1319 cow_start, found_key.offset - 1,
1320 page_started, nr_written, 1);
1321 if (ret) {
1322 btrfs_abort_transaction(trans, root, ret);
1323 goto error;
1324 }
1325 cow_start = (u64)-1;
1326 }
1327
1328 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1329 struct extent_map *em;
1330 struct extent_map_tree *em_tree;
1331 em_tree = &BTRFS_I(inode)->extent_tree;
1332 em = alloc_extent_map();
1333 BUG_ON(!em); /* -ENOMEM */
1334 em->start = cur_offset;
1335 em->orig_start = found_key.offset - extent_offset;
1336 em->len = num_bytes;
1337 em->block_len = num_bytes;
1338 em->block_start = disk_bytenr;
1339 em->orig_block_len = disk_num_bytes;
1340 em->bdev = root->fs_info->fs_devices->latest_bdev;
1341 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1342 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1343 em->generation = -1;
1344 while (1) {
1345 write_lock(&em_tree->lock);
1346 ret = add_extent_mapping(em_tree, em);
1347 if (!ret)
1348 list_move(&em->list,
1349 &em_tree->modified_extents);
1350 write_unlock(&em_tree->lock);
1351 if (ret != -EEXIST) {
1352 free_extent_map(em);
1353 break;
1354 }
1355 btrfs_drop_extent_cache(inode, em->start,
1356 em->start + em->len - 1, 0);
1357 }
1358 type = BTRFS_ORDERED_PREALLOC;
1359 } else {
1360 type = BTRFS_ORDERED_NOCOW;
1361 }
1362
1363 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1364 num_bytes, num_bytes, type);
1365 BUG_ON(ret); /* -ENOMEM */
1366
1367 if (root->root_key.objectid ==
1368 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1369 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1370 num_bytes);
1371 if (ret) {
1372 btrfs_abort_transaction(trans, root, ret);
1373 goto error;
1374 }
1375 }
1376
1377 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
1378 cur_offset, cur_offset + num_bytes - 1,
1379 locked_page, EXTENT_CLEAR_UNLOCK_PAGE |
1380 EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
1381 EXTENT_SET_PRIVATE2);
1382 cur_offset = extent_end;
1383 if (cur_offset > end)
1384 break;
1385 }
1386 btrfs_release_path(path);
1387
1388 if (cur_offset <= end && cow_start == (u64)-1) {
1389 cow_start = cur_offset;
1390 cur_offset = end;
1391 }
1392
1393 if (cow_start != (u64)-1) {
1394 ret = __cow_file_range(trans, inode, root, locked_page,
1395 cow_start, end,
1396 page_started, nr_written, 1);
1397 if (ret) {
1398 btrfs_abort_transaction(trans, root, ret);
1399 goto error;
1400 }
1401 }
1402
1403 error:
1404 err = btrfs_end_transaction(trans, root);
1405 if (!ret)
1406 ret = err;
1407
1408 if (ret && cur_offset < end)
1409 extent_clear_unlock_delalloc(inode,
1410 &BTRFS_I(inode)->io_tree,
1411 cur_offset, end, locked_page,
1412 EXTENT_CLEAR_UNLOCK_PAGE |
1413 EXTENT_CLEAR_UNLOCK |
1414 EXTENT_CLEAR_DELALLOC |
1415 EXTENT_CLEAR_DIRTY |
1416 EXTENT_SET_WRITEBACK |
1417 EXTENT_END_WRITEBACK);
1418
1419 btrfs_free_path(path);
1420 return ret;
1421 }
1422
1423 /*
1424 * extent_io.c call back to do delayed allocation processing
1425 */
1426 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1427 u64 start, u64 end, int *page_started,
1428 unsigned long *nr_written)
1429 {
1430 int ret;
1431 struct btrfs_root *root = BTRFS_I(inode)->root;
1432
1433 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) {
1434 ret = run_delalloc_nocow(inode, locked_page, start, end,
1435 page_started, 1, nr_written);
1436 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC) {
1437 ret = run_delalloc_nocow(inode, locked_page, start, end,
1438 page_started, 0, nr_written);
1439 } else if (!btrfs_test_opt(root, COMPRESS) &&
1440 !(BTRFS_I(inode)->force_compress) &&
1441 !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS)) {
1442 ret = cow_file_range(inode, locked_page, start, end,
1443 page_started, nr_written, 1);
1444 } else {
1445 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1446 &BTRFS_I(inode)->runtime_flags);
1447 ret = cow_file_range_async(inode, locked_page, start, end,
1448 page_started, nr_written);
1449 }
1450 return ret;
1451 }
1452
1453 static void btrfs_split_extent_hook(struct inode *inode,
1454 struct extent_state *orig, u64 split)
1455 {
1456 /* not delalloc, ignore it */
1457 if (!(orig->state & EXTENT_DELALLOC))
1458 return;
1459
1460 spin_lock(&BTRFS_I(inode)->lock);
1461 BTRFS_I(inode)->outstanding_extents++;
1462 spin_unlock(&BTRFS_I(inode)->lock);
1463 }
1464
1465 /*
1466 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1467 * extents so we can keep track of new extents that are just merged onto old
1468 * extents, such as when we are doing sequential writes, so we can properly
1469 * account for the metadata space we'll need.
1470 */
1471 static void btrfs_merge_extent_hook(struct inode *inode,
1472 struct extent_state *new,
1473 struct extent_state *other)
1474 {
1475 /* not delalloc, ignore it */
1476 if (!(other->state & EXTENT_DELALLOC))
1477 return;
1478
1479 spin_lock(&BTRFS_I(inode)->lock);
1480 BTRFS_I(inode)->outstanding_extents--;
1481 spin_unlock(&BTRFS_I(inode)->lock);
1482 }
1483
1484 /*
1485 * extent_io.c set_bit_hook, used to track delayed allocation
1486 * bytes in this file, and to maintain the list of inodes that
1487 * have pending delalloc work to be done.
1488 */
1489 static void btrfs_set_bit_hook(struct inode *inode,
1490 struct extent_state *state, int *bits)
1491 {
1492
1493 /*
1494 * set_bit and clear bit hooks normally require _irqsave/restore
1495 * but in this case, we are only testing for the DELALLOC
1496 * bit, which is only set or cleared with irqs on
1497 */
1498 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1499 struct btrfs_root *root = BTRFS_I(inode)->root;
1500 u64 len = state->end + 1 - state->start;
1501 bool do_list = !btrfs_is_free_space_inode(inode);
1502
1503 if (*bits & EXTENT_FIRST_DELALLOC) {
1504 *bits &= ~EXTENT_FIRST_DELALLOC;
1505 } else {
1506 spin_lock(&BTRFS_I(inode)->lock);
1507 BTRFS_I(inode)->outstanding_extents++;
1508 spin_unlock(&BTRFS_I(inode)->lock);
1509 }
1510
1511 spin_lock(&root->fs_info->delalloc_lock);
1512 BTRFS_I(inode)->delalloc_bytes += len;
1513 root->fs_info->delalloc_bytes += len;
1514 if (do_list && list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1515 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1516 &root->fs_info->delalloc_inodes);
1517 }
1518 spin_unlock(&root->fs_info->delalloc_lock);
1519 }
1520 }
1521
1522 /*
1523 * extent_io.c clear_bit_hook, see set_bit_hook for why
1524 */
1525 static void btrfs_clear_bit_hook(struct inode *inode,
1526 struct extent_state *state, int *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 if (*bits & EXTENT_DO_ACCOUNTING)
1547 btrfs_delalloc_release_metadata(inode, len);
1548
1549 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1550 && do_list)
1551 btrfs_free_reserved_data_space(inode, len);
1552
1553 spin_lock(&root->fs_info->delalloc_lock);
1554 root->fs_info->delalloc_bytes -= len;
1555 BTRFS_I(inode)->delalloc_bytes -= len;
1556
1557 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1558 !list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1559 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1560 }
1561 spin_unlock(&root->fs_info->delalloc_lock);
1562 }
1563 }
1564
1565 /*
1566 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1567 * we don't create bios that span stripes or chunks
1568 */
1569 int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
1570 size_t size, struct bio *bio,
1571 unsigned long bio_flags)
1572 {
1573 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1574 u64 logical = (u64)bio->bi_sector << 9;
1575 u64 length = 0;
1576 u64 map_length;
1577 int ret;
1578
1579 if (bio_flags & EXTENT_BIO_COMPRESSED)
1580 return 0;
1581
1582 length = bio->bi_size;
1583 map_length = length;
1584 ret = btrfs_map_block(root->fs_info, READ, logical,
1585 &map_length, NULL, 0);
1586 /* Will always return 0 with map_multi == NULL */
1587 BUG_ON(ret < 0);
1588 if (map_length < length + size)
1589 return 1;
1590 return 0;
1591 }
1592
1593 /*
1594 * in order to insert checksums into the metadata in large chunks,
1595 * we wait until bio submission time. All the pages in the bio are
1596 * checksummed and sums are attached onto the ordered extent record.
1597 *
1598 * At IO completion time the cums attached on the ordered extent record
1599 * are inserted into the btree
1600 */
1601 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1602 struct bio *bio, int mirror_num,
1603 unsigned long bio_flags,
1604 u64 bio_offset)
1605 {
1606 struct btrfs_root *root = BTRFS_I(inode)->root;
1607 int ret = 0;
1608
1609 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1610 BUG_ON(ret); /* -ENOMEM */
1611 return 0;
1612 }
1613
1614 /*
1615 * in order to insert checksums into the metadata in large chunks,
1616 * we wait until bio submission time. All the pages in the bio are
1617 * checksummed and sums are attached onto the ordered extent record.
1618 *
1619 * At IO completion time the cums attached on the ordered extent record
1620 * are inserted into the btree
1621 */
1622 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1623 int mirror_num, unsigned long bio_flags,
1624 u64 bio_offset)
1625 {
1626 struct btrfs_root *root = BTRFS_I(inode)->root;
1627 int ret;
1628
1629 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
1630 if (ret)
1631 bio_endio(bio, ret);
1632 return ret;
1633 }
1634
1635 /*
1636 * extent_io.c submission hook. This does the right thing for csum calculation
1637 * on write, or reading the csums from the tree before a read
1638 */
1639 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1640 int mirror_num, unsigned long bio_flags,
1641 u64 bio_offset)
1642 {
1643 struct btrfs_root *root = BTRFS_I(inode)->root;
1644 int ret = 0;
1645 int skip_sum;
1646 int metadata = 0;
1647 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1648
1649 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1650
1651 if (btrfs_is_free_space_inode(inode))
1652 metadata = 2;
1653
1654 if (!(rw & REQ_WRITE)) {
1655 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1656 if (ret)
1657 goto out;
1658
1659 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1660 ret = btrfs_submit_compressed_read(inode, bio,
1661 mirror_num,
1662 bio_flags);
1663 goto out;
1664 } else if (!skip_sum) {
1665 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1666 if (ret)
1667 goto out;
1668 }
1669 goto mapit;
1670 } else if (async && !skip_sum) {
1671 /* csum items have already been cloned */
1672 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1673 goto mapit;
1674 /* we're doing a write, do the async checksumming */
1675 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1676 inode, rw, bio, mirror_num,
1677 bio_flags, bio_offset,
1678 __btrfs_submit_bio_start,
1679 __btrfs_submit_bio_done);
1680 goto out;
1681 } else if (!skip_sum) {
1682 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1683 if (ret)
1684 goto out;
1685 }
1686
1687 mapit:
1688 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
1689
1690 out:
1691 if (ret < 0)
1692 bio_endio(bio, ret);
1693 return ret;
1694 }
1695
1696 /*
1697 * given a list of ordered sums record them in the inode. This happens
1698 * at IO completion time based on sums calculated at bio submission time.
1699 */
1700 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1701 struct inode *inode, u64 file_offset,
1702 struct list_head *list)
1703 {
1704 struct btrfs_ordered_sum *sum;
1705
1706 list_for_each_entry(sum, list, list) {
1707 btrfs_csum_file_blocks(trans,
1708 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1709 }
1710 return 0;
1711 }
1712
1713 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1714 struct extent_state **cached_state)
1715 {
1716 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0);
1717 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1718 cached_state, GFP_NOFS);
1719 }
1720
1721 /* see btrfs_writepage_start_hook for details on why this is required */
1722 struct btrfs_writepage_fixup {
1723 struct page *page;
1724 struct btrfs_work work;
1725 };
1726
1727 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1728 {
1729 struct btrfs_writepage_fixup *fixup;
1730 struct btrfs_ordered_extent *ordered;
1731 struct extent_state *cached_state = NULL;
1732 struct page *page;
1733 struct inode *inode;
1734 u64 page_start;
1735 u64 page_end;
1736 int ret;
1737
1738 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1739 page = fixup->page;
1740 again:
1741 lock_page(page);
1742 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1743 ClearPageChecked(page);
1744 goto out_page;
1745 }
1746
1747 inode = page->mapping->host;
1748 page_start = page_offset(page);
1749 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1750
1751 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
1752 &cached_state);
1753
1754 /* already ordered? We're done */
1755 if (PagePrivate2(page))
1756 goto out;
1757
1758 ordered = btrfs_lookup_ordered_extent(inode, page_start);
1759 if (ordered) {
1760 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
1761 page_end, &cached_state, GFP_NOFS);
1762 unlock_page(page);
1763 btrfs_start_ordered_extent(inode, ordered, 1);
1764 btrfs_put_ordered_extent(ordered);
1765 goto again;
1766 }
1767
1768 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
1769 if (ret) {
1770 mapping_set_error(page->mapping, ret);
1771 end_extent_writepage(page, ret, page_start, page_end);
1772 ClearPageChecked(page);
1773 goto out;
1774 }
1775
1776 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
1777 ClearPageChecked(page);
1778 set_page_dirty(page);
1779 out:
1780 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
1781 &cached_state, GFP_NOFS);
1782 out_page:
1783 unlock_page(page);
1784 page_cache_release(page);
1785 kfree(fixup);
1786 }
1787
1788 /*
1789 * There are a few paths in the higher layers of the kernel that directly
1790 * set the page dirty bit without asking the filesystem if it is a
1791 * good idea. This causes problems because we want to make sure COW
1792 * properly happens and the data=ordered rules are followed.
1793 *
1794 * In our case any range that doesn't have the ORDERED bit set
1795 * hasn't been properly setup for IO. We kick off an async process
1796 * to fix it up. The async helper will wait for ordered extents, set
1797 * the delalloc bit and make it safe to write the page.
1798 */
1799 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
1800 {
1801 struct inode *inode = page->mapping->host;
1802 struct btrfs_writepage_fixup *fixup;
1803 struct btrfs_root *root = BTRFS_I(inode)->root;
1804
1805 /* this page is properly in the ordered list */
1806 if (TestClearPagePrivate2(page))
1807 return 0;
1808
1809 if (PageChecked(page))
1810 return -EAGAIN;
1811
1812 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
1813 if (!fixup)
1814 return -EAGAIN;
1815
1816 SetPageChecked(page);
1817 page_cache_get(page);
1818 fixup->work.func = btrfs_writepage_fixup_worker;
1819 fixup->page = page;
1820 btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
1821 return -EBUSY;
1822 }
1823
1824 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
1825 struct inode *inode, u64 file_pos,
1826 u64 disk_bytenr, u64 disk_num_bytes,
1827 u64 num_bytes, u64 ram_bytes,
1828 u8 compression, u8 encryption,
1829 u16 other_encoding, int extent_type)
1830 {
1831 struct btrfs_root *root = BTRFS_I(inode)->root;
1832 struct btrfs_file_extent_item *fi;
1833 struct btrfs_path *path;
1834 struct extent_buffer *leaf;
1835 struct btrfs_key ins;
1836 int ret;
1837
1838 path = btrfs_alloc_path();
1839 if (!path)
1840 return -ENOMEM;
1841
1842 path->leave_spinning = 1;
1843
1844 /*
1845 * we may be replacing one extent in the tree with another.
1846 * The new extent is pinned in the extent map, and we don't want
1847 * to drop it from the cache until it is completely in the btree.
1848 *
1849 * So, tell btrfs_drop_extents to leave this extent in the cache.
1850 * the caller is expected to unpin it and allow it to be merged
1851 * with the others.
1852 */
1853 ret = btrfs_drop_extents(trans, root, inode, file_pos,
1854 file_pos + num_bytes, 0);
1855 if (ret)
1856 goto out;
1857
1858 ins.objectid = btrfs_ino(inode);
1859 ins.offset = file_pos;
1860 ins.type = BTRFS_EXTENT_DATA_KEY;
1861 ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi));
1862 if (ret)
1863 goto out;
1864 leaf = path->nodes[0];
1865 fi = btrfs_item_ptr(leaf, path->slots[0],
1866 struct btrfs_file_extent_item);
1867 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1868 btrfs_set_file_extent_type(leaf, fi, extent_type);
1869 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
1870 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
1871 btrfs_set_file_extent_offset(leaf, fi, 0);
1872 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
1873 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
1874 btrfs_set_file_extent_compression(leaf, fi, compression);
1875 btrfs_set_file_extent_encryption(leaf, fi, encryption);
1876 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
1877
1878 btrfs_mark_buffer_dirty(leaf);
1879 btrfs_release_path(path);
1880
1881 inode_add_bytes(inode, num_bytes);
1882
1883 ins.objectid = disk_bytenr;
1884 ins.offset = disk_num_bytes;
1885 ins.type = BTRFS_EXTENT_ITEM_KEY;
1886 ret = btrfs_alloc_reserved_file_extent(trans, root,
1887 root->root_key.objectid,
1888 btrfs_ino(inode), file_pos, &ins);
1889 out:
1890 btrfs_free_path(path);
1891
1892 return ret;
1893 }
1894
1895 /*
1896 * helper function for btrfs_finish_ordered_io, this
1897 * just reads in some of the csum leaves to prime them into ram
1898 * before we start the transaction. It limits the amount of btree
1899 * reads required while inside the transaction.
1900 */
1901 /* as ordered data IO finishes, this gets called so we can finish
1902 * an ordered extent if the range of bytes in the file it covers are
1903 * fully written.
1904 */
1905 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
1906 {
1907 struct inode *inode = ordered_extent->inode;
1908 struct btrfs_root *root = BTRFS_I(inode)->root;
1909 struct btrfs_trans_handle *trans = NULL;
1910 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1911 struct extent_state *cached_state = NULL;
1912 int compress_type = 0;
1913 int ret;
1914 bool nolock;
1915
1916 nolock = btrfs_is_free_space_inode(inode);
1917
1918 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
1919 ret = -EIO;
1920 goto out;
1921 }
1922
1923 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
1924 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
1925 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
1926 if (nolock)
1927 trans = btrfs_join_transaction_nolock(root);
1928 else
1929 trans = btrfs_join_transaction(root);
1930 if (IS_ERR(trans)) {
1931 ret = PTR_ERR(trans);
1932 trans = NULL;
1933 goto out;
1934 }
1935 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1936 ret = btrfs_update_inode_fallback(trans, root, inode);
1937 if (ret) /* -ENOMEM or corruption */
1938 btrfs_abort_transaction(trans, root, ret);
1939 goto out;
1940 }
1941
1942 lock_extent_bits(io_tree, ordered_extent->file_offset,
1943 ordered_extent->file_offset + ordered_extent->len - 1,
1944 0, &cached_state);
1945
1946 if (nolock)
1947 trans = btrfs_join_transaction_nolock(root);
1948 else
1949 trans = btrfs_join_transaction(root);
1950 if (IS_ERR(trans)) {
1951 ret = PTR_ERR(trans);
1952 trans = NULL;
1953 goto out_unlock;
1954 }
1955 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1956
1957 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
1958 compress_type = ordered_extent->compress_type;
1959 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
1960 BUG_ON(compress_type);
1961 ret = btrfs_mark_extent_written(trans, inode,
1962 ordered_extent->file_offset,
1963 ordered_extent->file_offset +
1964 ordered_extent->len);
1965 } else {
1966 BUG_ON(root == root->fs_info->tree_root);
1967 ret = insert_reserved_file_extent(trans, inode,
1968 ordered_extent->file_offset,
1969 ordered_extent->start,
1970 ordered_extent->disk_len,
1971 ordered_extent->len,
1972 ordered_extent->len,
1973 compress_type, 0, 0,
1974 BTRFS_FILE_EXTENT_REG);
1975 }
1976 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
1977 ordered_extent->file_offset, ordered_extent->len,
1978 trans->transid);
1979 if (ret < 0) {
1980 btrfs_abort_transaction(trans, root, ret);
1981 goto out_unlock;
1982 }
1983
1984 add_pending_csums(trans, inode, ordered_extent->file_offset,
1985 &ordered_extent->list);
1986
1987 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
1988 ret = btrfs_update_inode_fallback(trans, root, inode);
1989 if (ret) { /* -ENOMEM or corruption */
1990 btrfs_abort_transaction(trans, root, ret);
1991 goto out_unlock;
1992 }
1993 ret = 0;
1994 out_unlock:
1995 unlock_extent_cached(io_tree, ordered_extent->file_offset,
1996 ordered_extent->file_offset +
1997 ordered_extent->len - 1, &cached_state, GFP_NOFS);
1998 out:
1999 if (root != root->fs_info->tree_root)
2000 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2001 if (trans)
2002 btrfs_end_transaction(trans, root);
2003
2004 if (ret)
2005 clear_extent_uptodate(io_tree, ordered_extent->file_offset,
2006 ordered_extent->file_offset +
2007 ordered_extent->len - 1, NULL, GFP_NOFS);
2008
2009 /*
2010 * This needs to be done to make sure anybody waiting knows we are done
2011 * updating everything for this ordered extent.
2012 */
2013 btrfs_remove_ordered_extent(inode, ordered_extent);
2014
2015 /* once for us */
2016 btrfs_put_ordered_extent(ordered_extent);
2017 /* once for the tree */
2018 btrfs_put_ordered_extent(ordered_extent);
2019
2020 return ret;
2021 }
2022
2023 static void finish_ordered_fn(struct btrfs_work *work)
2024 {
2025 struct btrfs_ordered_extent *ordered_extent;
2026 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
2027 btrfs_finish_ordered_io(ordered_extent);
2028 }
2029
2030 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
2031 struct extent_state *state, int uptodate)
2032 {
2033 struct inode *inode = page->mapping->host;
2034 struct btrfs_root *root = BTRFS_I(inode)->root;
2035 struct btrfs_ordered_extent *ordered_extent = NULL;
2036 struct btrfs_workers *workers;
2037
2038 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
2039
2040 ClearPagePrivate2(page);
2041 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
2042 end - start + 1, uptodate))
2043 return 0;
2044
2045 ordered_extent->work.func = finish_ordered_fn;
2046 ordered_extent->work.flags = 0;
2047
2048 if (btrfs_is_free_space_inode(inode))
2049 workers = &root->fs_info->endio_freespace_worker;
2050 else
2051 workers = &root->fs_info->endio_write_workers;
2052 btrfs_queue_worker(workers, &ordered_extent->work);
2053
2054 return 0;
2055 }
2056
2057 /*
2058 * when reads are done, we need to check csums to verify the data is correct
2059 * if there's a match, we allow the bio to finish. If not, the code in
2060 * extent_io.c will try to find good copies for us.
2061 */
2062 static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
2063 struct extent_state *state, int mirror)
2064 {
2065 size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
2066 struct inode *inode = page->mapping->host;
2067 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2068 char *kaddr;
2069 u64 private = ~(u32)0;
2070 int ret;
2071 struct btrfs_root *root = BTRFS_I(inode)->root;
2072 u32 csum = ~(u32)0;
2073
2074 if (PageChecked(page)) {
2075 ClearPageChecked(page);
2076 goto good;
2077 }
2078
2079 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
2080 goto good;
2081
2082 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
2083 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
2084 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
2085 GFP_NOFS);
2086 return 0;
2087 }
2088
2089 if (state && state->start == start) {
2090 private = state->private;
2091 ret = 0;
2092 } else {
2093 ret = get_state_private(io_tree, start, &private);
2094 }
2095 kaddr = kmap_atomic(page);
2096 if (ret)
2097 goto zeroit;
2098
2099 csum = btrfs_csum_data(root, kaddr + offset, csum, end - start + 1);
2100 btrfs_csum_final(csum, (char *)&csum);
2101 if (csum != private)
2102 goto zeroit;
2103
2104 kunmap_atomic(kaddr);
2105 good:
2106 return 0;
2107
2108 zeroit:
2109 printk_ratelimited(KERN_INFO "btrfs csum failed ino %llu off %llu csum %u "
2110 "private %llu\n",
2111 (unsigned long long)btrfs_ino(page->mapping->host),
2112 (unsigned long long)start, csum,
2113 (unsigned long long)private);
2114 memset(kaddr + offset, 1, end - start + 1);
2115 flush_dcache_page(page);
2116 kunmap_atomic(kaddr);
2117 if (private == 0)
2118 return 0;
2119 return -EIO;
2120 }
2121
2122 struct delayed_iput {
2123 struct list_head list;
2124 struct inode *inode;
2125 };
2126
2127 /* JDM: If this is fs-wide, why can't we add a pointer to
2128 * btrfs_inode instead and avoid the allocation? */
2129 void btrfs_add_delayed_iput(struct inode *inode)
2130 {
2131 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2132 struct delayed_iput *delayed;
2133
2134 if (atomic_add_unless(&inode->i_count, -1, 1))
2135 return;
2136
2137 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
2138 delayed->inode = inode;
2139
2140 spin_lock(&fs_info->delayed_iput_lock);
2141 list_add_tail(&delayed->list, &fs_info->delayed_iputs);
2142 spin_unlock(&fs_info->delayed_iput_lock);
2143 }
2144
2145 void btrfs_run_delayed_iputs(struct btrfs_root *root)
2146 {
2147 LIST_HEAD(list);
2148 struct btrfs_fs_info *fs_info = root->fs_info;
2149 struct delayed_iput *delayed;
2150 int empty;
2151
2152 spin_lock(&fs_info->delayed_iput_lock);
2153 empty = list_empty(&fs_info->delayed_iputs);
2154 spin_unlock(&fs_info->delayed_iput_lock);
2155 if (empty)
2156 return;
2157
2158 spin_lock(&fs_info->delayed_iput_lock);
2159 list_splice_init(&fs_info->delayed_iputs, &list);
2160 spin_unlock(&fs_info->delayed_iput_lock);
2161
2162 while (!list_empty(&list)) {
2163 delayed = list_entry(list.next, struct delayed_iput, list);
2164 list_del(&delayed->list);
2165 iput(delayed->inode);
2166 kfree(delayed);
2167 }
2168 }
2169
2170 enum btrfs_orphan_cleanup_state {
2171 ORPHAN_CLEANUP_STARTED = 1,
2172 ORPHAN_CLEANUP_DONE = 2,
2173 };
2174
2175 /*
2176 * This is called in transaction commit time. If there are no orphan
2177 * files in the subvolume, it removes orphan item and frees block_rsv
2178 * structure.
2179 */
2180 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
2181 struct btrfs_root *root)
2182 {
2183 struct btrfs_block_rsv *block_rsv;
2184 int ret;
2185
2186 if (atomic_read(&root->orphan_inodes) ||
2187 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
2188 return;
2189
2190 spin_lock(&root->orphan_lock);
2191 if (atomic_read(&root->orphan_inodes)) {
2192 spin_unlock(&root->orphan_lock);
2193 return;
2194 }
2195
2196 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
2197 spin_unlock(&root->orphan_lock);
2198 return;
2199 }
2200
2201 block_rsv = root->orphan_block_rsv;
2202 root->orphan_block_rsv = NULL;
2203 spin_unlock(&root->orphan_lock);
2204
2205 if (root->orphan_item_inserted &&
2206 btrfs_root_refs(&root->root_item) > 0) {
2207 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
2208 root->root_key.objectid);
2209 BUG_ON(ret);
2210 root->orphan_item_inserted = 0;
2211 }
2212
2213 if (block_rsv) {
2214 WARN_ON(block_rsv->size > 0);
2215 btrfs_free_block_rsv(root, block_rsv);
2216 }
2217 }
2218
2219 /*
2220 * This creates an orphan entry for the given inode in case something goes
2221 * wrong in the middle of an unlink/truncate.
2222 *
2223 * NOTE: caller of this function should reserve 5 units of metadata for
2224 * this function.
2225 */
2226 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
2227 {
2228 struct btrfs_root *root = BTRFS_I(inode)->root;
2229 struct btrfs_block_rsv *block_rsv = NULL;
2230 int reserve = 0;
2231 int insert = 0;
2232 int ret;
2233
2234 if (!root->orphan_block_rsv) {
2235 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
2236 if (!block_rsv)
2237 return -ENOMEM;
2238 }
2239
2240 spin_lock(&root->orphan_lock);
2241 if (!root->orphan_block_rsv) {
2242 root->orphan_block_rsv = block_rsv;
2243 } else if (block_rsv) {
2244 btrfs_free_block_rsv(root, block_rsv);
2245 block_rsv = NULL;
2246 }
2247
2248 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
2249 &BTRFS_I(inode)->runtime_flags)) {
2250 #if 0
2251 /*
2252 * For proper ENOSPC handling, we should do orphan
2253 * cleanup when mounting. But this introduces backward
2254 * compatibility issue.
2255 */
2256 if (!xchg(&root->orphan_item_inserted, 1))
2257 insert = 2;
2258 else
2259 insert = 1;
2260 #endif
2261 insert = 1;
2262 atomic_inc(&root->orphan_inodes);
2263 }
2264
2265 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
2266 &BTRFS_I(inode)->runtime_flags))
2267 reserve = 1;
2268 spin_unlock(&root->orphan_lock);
2269
2270 /* grab metadata reservation from transaction handle */
2271 if (reserve) {
2272 ret = btrfs_orphan_reserve_metadata(trans, inode);
2273 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
2274 }
2275
2276 /* insert an orphan item to track this unlinked/truncated file */
2277 if (insert >= 1) {
2278 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
2279 if (ret && ret != -EEXIST) {
2280 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
2281 &BTRFS_I(inode)->runtime_flags);
2282 btrfs_abort_transaction(trans, root, ret);
2283 return ret;
2284 }
2285 ret = 0;
2286 }
2287
2288 /* insert an orphan item to track subvolume contains orphan files */
2289 if (insert >= 2) {
2290 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
2291 root->root_key.objectid);
2292 if (ret && ret != -EEXIST) {
2293 btrfs_abort_transaction(trans, root, ret);
2294 return ret;
2295 }
2296 }
2297 return 0;
2298 }
2299
2300 /*
2301 * We have done the truncate/delete so we can go ahead and remove the orphan
2302 * item for this particular inode.
2303 */
2304 int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode)
2305 {
2306 struct btrfs_root *root = BTRFS_I(inode)->root;
2307 int delete_item = 0;
2308 int release_rsv = 0;
2309 int ret = 0;
2310
2311 spin_lock(&root->orphan_lock);
2312 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
2313 &BTRFS_I(inode)->runtime_flags))
2314 delete_item = 1;
2315
2316 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
2317 &BTRFS_I(inode)->runtime_flags))
2318 release_rsv = 1;
2319 spin_unlock(&root->orphan_lock);
2320
2321 if (trans && delete_item) {
2322 ret = btrfs_del_orphan_item(trans, root, btrfs_ino(inode));
2323 BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */
2324 }
2325
2326 if (release_rsv) {
2327 btrfs_orphan_release_metadata(inode);
2328 atomic_dec(&root->orphan_inodes);
2329 }
2330
2331 return 0;
2332 }
2333
2334 /*
2335 * this cleans up any orphans that may be left on the list from the last use
2336 * of this root.
2337 */
2338 int btrfs_orphan_cleanup(struct btrfs_root *root)
2339 {
2340 struct btrfs_path *path;
2341 struct extent_buffer *leaf;
2342 struct btrfs_key key, found_key;
2343 struct btrfs_trans_handle *trans;
2344 struct inode *inode;
2345 u64 last_objectid = 0;
2346 int ret = 0, nr_unlink = 0, nr_truncate = 0;
2347
2348 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
2349 return 0;
2350
2351 path = btrfs_alloc_path();
2352 if (!path) {
2353 ret = -ENOMEM;
2354 goto out;
2355 }
2356 path->reada = -1;
2357
2358 key.objectid = BTRFS_ORPHAN_OBJECTID;
2359 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
2360 key.offset = (u64)-1;
2361
2362 while (1) {
2363 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2364 if (ret < 0)
2365 goto out;
2366
2367 /*
2368 * if ret == 0 means we found what we were searching for, which
2369 * is weird, but possible, so only screw with path if we didn't
2370 * find the key and see if we have stuff that matches
2371 */
2372 if (ret > 0) {
2373 ret = 0;
2374 if (path->slots[0] == 0)
2375 break;
2376 path->slots[0]--;
2377 }
2378
2379 /* pull out the item */
2380 leaf = path->nodes[0];
2381 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2382
2383 /* make sure the item matches what we want */
2384 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
2385 break;
2386 if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
2387 break;
2388
2389 /* release the path since we're done with it */
2390 btrfs_release_path(path);
2391
2392 /*
2393 * this is where we are basically btrfs_lookup, without the
2394 * crossing root thing. we store the inode number in the
2395 * offset of the orphan item.
2396 */
2397
2398 if (found_key.offset == last_objectid) {
2399 printk(KERN_ERR "btrfs: Error removing orphan entry, "
2400 "stopping orphan cleanup\n");
2401 ret = -EINVAL;
2402 goto out;
2403 }
2404
2405 last_objectid = found_key.offset;
2406
2407 found_key.objectid = found_key.offset;
2408 found_key.type = BTRFS_INODE_ITEM_KEY;
2409 found_key.offset = 0;
2410 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
2411 ret = PTR_RET(inode);
2412 if (ret && ret != -ESTALE)
2413 goto out;
2414
2415 if (ret == -ESTALE && root == root->fs_info->tree_root) {
2416 struct btrfs_root *dead_root;
2417 struct btrfs_fs_info *fs_info = root->fs_info;
2418 int is_dead_root = 0;
2419
2420 /*
2421 * this is an orphan in the tree root. Currently these
2422 * could come from 2 sources:
2423 * a) a snapshot deletion in progress
2424 * b) a free space cache inode
2425 * We need to distinguish those two, as the snapshot
2426 * orphan must not get deleted.
2427 * find_dead_roots already ran before us, so if this
2428 * is a snapshot deletion, we should find the root
2429 * in the dead_roots list
2430 */
2431 spin_lock(&fs_info->trans_lock);
2432 list_for_each_entry(dead_root, &fs_info->dead_roots,
2433 root_list) {
2434 if (dead_root->root_key.objectid ==
2435 found_key.objectid) {
2436 is_dead_root = 1;
2437 break;
2438 }
2439 }
2440 spin_unlock(&fs_info->trans_lock);
2441 if (is_dead_root) {
2442 /* prevent this orphan from being found again */
2443 key.offset = found_key.objectid - 1;
2444 continue;
2445 }
2446 }
2447 /*
2448 * Inode is already gone but the orphan item is still there,
2449 * kill the orphan item.
2450 */
2451 if (ret == -ESTALE) {
2452 trans = btrfs_start_transaction(root, 1);
2453 if (IS_ERR(trans)) {
2454 ret = PTR_ERR(trans);
2455 goto out;
2456 }
2457 printk(KERN_ERR "auto deleting %Lu\n",
2458 found_key.objectid);
2459 ret = btrfs_del_orphan_item(trans, root,
2460 found_key.objectid);
2461 BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */
2462 btrfs_end_transaction(trans, root);
2463 continue;
2464 }
2465
2466 /*
2467 * add this inode to the orphan list so btrfs_orphan_del does
2468 * the proper thing when we hit it
2469 */
2470 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
2471 &BTRFS_I(inode)->runtime_flags);
2472
2473 /* if we have links, this was a truncate, lets do that */
2474 if (inode->i_nlink) {
2475 if (!S_ISREG(inode->i_mode)) {
2476 WARN_ON(1);
2477 iput(inode);
2478 continue;
2479 }
2480 nr_truncate++;
2481 ret = btrfs_truncate(inode);
2482 } else {
2483 nr_unlink++;
2484 }
2485
2486 /* this will do delete_inode and everything for us */
2487 iput(inode);
2488 if (ret)
2489 goto out;
2490 }
2491 /* release the path since we're done with it */
2492 btrfs_release_path(path);
2493
2494 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
2495
2496 if (root->orphan_block_rsv)
2497 btrfs_block_rsv_release(root, root->orphan_block_rsv,
2498 (u64)-1);
2499
2500 if (root->orphan_block_rsv || root->orphan_item_inserted) {
2501 trans = btrfs_join_transaction(root);
2502 if (!IS_ERR(trans))
2503 btrfs_end_transaction(trans, root);
2504 }
2505
2506 if (nr_unlink)
2507 printk(KERN_INFO "btrfs: unlinked %d orphans\n", nr_unlink);
2508 if (nr_truncate)
2509 printk(KERN_INFO "btrfs: truncated %d orphans\n", nr_truncate);
2510
2511 out:
2512 if (ret)
2513 printk(KERN_CRIT "btrfs: could not do orphan cleanup %d\n", ret);
2514 btrfs_free_path(path);
2515 return ret;
2516 }
2517
2518 /*
2519 * very simple check to peek ahead in the leaf looking for xattrs. If we
2520 * don't find any xattrs, we know there can't be any acls.
2521 *
2522 * slot is the slot the inode is in, objectid is the objectid of the inode
2523 */
2524 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
2525 int slot, u64 objectid)
2526 {
2527 u32 nritems = btrfs_header_nritems(leaf);
2528 struct btrfs_key found_key;
2529 int scanned = 0;
2530
2531 slot++;
2532 while (slot < nritems) {
2533 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2534
2535 /* we found a different objectid, there must not be acls */
2536 if (found_key.objectid != objectid)
2537 return 0;
2538
2539 /* we found an xattr, assume we've got an acl */
2540 if (found_key.type == BTRFS_XATTR_ITEM_KEY)
2541 return 1;
2542
2543 /*
2544 * we found a key greater than an xattr key, there can't
2545 * be any acls later on
2546 */
2547 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
2548 return 0;
2549
2550 slot++;
2551 scanned++;
2552
2553 /*
2554 * it goes inode, inode backrefs, xattrs, extents,
2555 * so if there are a ton of hard links to an inode there can
2556 * be a lot of backrefs. Don't waste time searching too hard,
2557 * this is just an optimization
2558 */
2559 if (scanned >= 8)
2560 break;
2561 }
2562 /* we hit the end of the leaf before we found an xattr or
2563 * something larger than an xattr. We have to assume the inode
2564 * has acls
2565 */
2566 return 1;
2567 }
2568
2569 /*
2570 * read an inode from the btree into the in-memory inode
2571 */
2572 static void btrfs_read_locked_inode(struct inode *inode)
2573 {
2574 struct btrfs_path *path;
2575 struct extent_buffer *leaf;
2576 struct btrfs_inode_item *inode_item;
2577 struct btrfs_timespec *tspec;
2578 struct btrfs_root *root = BTRFS_I(inode)->root;
2579 struct btrfs_key location;
2580 int maybe_acls;
2581 u32 rdev;
2582 int ret;
2583 bool filled = false;
2584
2585 ret = btrfs_fill_inode(inode, &rdev);
2586 if (!ret)
2587 filled = true;
2588
2589 path = btrfs_alloc_path();
2590 if (!path)
2591 goto make_bad;
2592
2593 path->leave_spinning = 1;
2594 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
2595
2596 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
2597 if (ret)
2598 goto make_bad;
2599
2600 leaf = path->nodes[0];
2601
2602 if (filled)
2603 goto cache_acl;
2604
2605 inode_item = btrfs_item_ptr(leaf, path->slots[0],
2606 struct btrfs_inode_item);
2607 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
2608 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
2609 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
2610 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
2611 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
2612
2613 tspec = btrfs_inode_atime(inode_item);
2614 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
2615 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
2616
2617 tspec = btrfs_inode_mtime(inode_item);
2618 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
2619 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
2620
2621 tspec = btrfs_inode_ctime(inode_item);
2622 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
2623 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
2624
2625 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
2626 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
2627 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
2628
2629 /*
2630 * If we were modified in the current generation and evicted from memory
2631 * and then re-read we need to do a full sync since we don't have any
2632 * idea about which extents were modified before we were evicted from
2633 * cache.
2634 */
2635 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
2636 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2637 &BTRFS_I(inode)->runtime_flags);
2638
2639 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
2640 inode->i_generation = BTRFS_I(inode)->generation;
2641 inode->i_rdev = 0;
2642 rdev = btrfs_inode_rdev(leaf, inode_item);
2643
2644 BTRFS_I(inode)->index_cnt = (u64)-1;
2645 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
2646 cache_acl:
2647 /*
2648 * try to precache a NULL acl entry for files that don't have
2649 * any xattrs or acls
2650 */
2651 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
2652 btrfs_ino(inode));
2653 if (!maybe_acls)
2654 cache_no_acl(inode);
2655
2656 btrfs_free_path(path);
2657
2658 switch (inode->i_mode & S_IFMT) {
2659 case S_IFREG:
2660 inode->i_mapping->a_ops = &btrfs_aops;
2661 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
2662 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
2663 inode->i_fop = &btrfs_file_operations;
2664 inode->i_op = &btrfs_file_inode_operations;
2665 break;
2666 case S_IFDIR:
2667 inode->i_fop = &btrfs_dir_file_operations;
2668 if (root == root->fs_info->tree_root)
2669 inode->i_op = &btrfs_dir_ro_inode_operations;
2670 else
2671 inode->i_op = &btrfs_dir_inode_operations;
2672 break;
2673 case S_IFLNK:
2674 inode->i_op = &btrfs_symlink_inode_operations;
2675 inode->i_mapping->a_ops = &btrfs_symlink_aops;
2676 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
2677 break;
2678 default:
2679 inode->i_op = &btrfs_special_inode_operations;
2680 init_special_inode(inode, inode->i_mode, rdev);
2681 break;
2682 }
2683
2684 btrfs_update_iflags(inode);
2685 return;
2686
2687 make_bad:
2688 btrfs_free_path(path);
2689 make_bad_inode(inode);
2690 }
2691
2692 /*
2693 * given a leaf and an inode, copy the inode fields into the leaf
2694 */
2695 static void fill_inode_item(struct btrfs_trans_handle *trans,
2696 struct extent_buffer *leaf,
2697 struct btrfs_inode_item *item,
2698 struct inode *inode)
2699 {
2700 btrfs_set_inode_uid(leaf, item, i_uid_read(inode));
2701 btrfs_set_inode_gid(leaf, item, i_gid_read(inode));
2702 btrfs_set_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size);
2703 btrfs_set_inode_mode(leaf, item, inode->i_mode);
2704 btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
2705
2706 btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
2707 inode->i_atime.tv_sec);
2708 btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
2709 inode->i_atime.tv_nsec);
2710
2711 btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
2712 inode->i_mtime.tv_sec);
2713 btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
2714 inode->i_mtime.tv_nsec);
2715
2716 btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
2717 inode->i_ctime.tv_sec);
2718 btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
2719 inode->i_ctime.tv_nsec);
2720
2721 btrfs_set_inode_nbytes(leaf, item, inode_get_bytes(inode));
2722 btrfs_set_inode_generation(leaf, item, BTRFS_I(inode)->generation);
2723 btrfs_set_inode_sequence(leaf, item, inode->i_version);
2724 btrfs_set_inode_transid(leaf, item, trans->transid);
2725 btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
2726 btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags);
2727 btrfs_set_inode_block_group(leaf, item, 0);
2728 }
2729
2730 /*
2731 * copy everything in the in-memory inode into the btree.
2732 */
2733 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
2734 struct btrfs_root *root, struct inode *inode)
2735 {
2736 struct btrfs_inode_item *inode_item;
2737 struct btrfs_path *path;
2738 struct extent_buffer *leaf;
2739 int ret;
2740
2741 path = btrfs_alloc_path();
2742 if (!path)
2743 return -ENOMEM;
2744
2745 path->leave_spinning = 1;
2746 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
2747 1);
2748 if (ret) {
2749 if (ret > 0)
2750 ret = -ENOENT;
2751 goto failed;
2752 }
2753
2754 btrfs_unlock_up_safe(path, 1);
2755 leaf = path->nodes[0];
2756 inode_item = btrfs_item_ptr(leaf, path->slots[0],
2757 struct btrfs_inode_item);
2758
2759 fill_inode_item(trans, leaf, inode_item, inode);
2760 btrfs_mark_buffer_dirty(leaf);
2761 btrfs_set_inode_last_trans(trans, inode);
2762 ret = 0;
2763 failed:
2764 btrfs_free_path(path);
2765 return ret;
2766 }
2767
2768 /*
2769 * copy everything in the in-memory inode into the btree.
2770 */
2771 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
2772 struct btrfs_root *root, struct inode *inode)
2773 {
2774 int ret;
2775
2776 /*
2777 * If the inode is a free space inode, we can deadlock during commit
2778 * if we put it into the delayed code.
2779 *
2780 * The data relocation inode should also be directly updated
2781 * without delay
2782 */
2783 if (!btrfs_is_free_space_inode(inode)
2784 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) {
2785 btrfs_update_root_times(trans, root);
2786
2787 ret = btrfs_delayed_update_inode(trans, root, inode);
2788 if (!ret)
2789 btrfs_set_inode_last_trans(trans, inode);
2790 return ret;
2791 }
2792
2793 return btrfs_update_inode_item(trans, root, inode);
2794 }
2795
2796 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
2797 struct btrfs_root *root,
2798 struct inode *inode)
2799 {
2800 int ret;
2801
2802 ret = btrfs_update_inode(trans, root, inode);
2803 if (ret == -ENOSPC)
2804 return btrfs_update_inode_item(trans, root, inode);
2805 return ret;
2806 }
2807
2808 /*
2809 * unlink helper that gets used here in inode.c and in the tree logging
2810 * recovery code. It remove a link in a directory with a given name, and
2811 * also drops the back refs in the inode to the directory
2812 */
2813 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
2814 struct btrfs_root *root,
2815 struct inode *dir, struct inode *inode,
2816 const char *name, int name_len)
2817 {
2818 struct btrfs_path *path;
2819 int ret = 0;
2820 struct extent_buffer *leaf;
2821 struct btrfs_dir_item *di;
2822 struct btrfs_key key;
2823 u64 index;
2824 u64 ino = btrfs_ino(inode);
2825 u64 dir_ino = btrfs_ino(dir);
2826
2827 path = btrfs_alloc_path();
2828 if (!path) {
2829 ret = -ENOMEM;
2830 goto out;
2831 }
2832
2833 path->leave_spinning = 1;
2834 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
2835 name, name_len, -1);
2836 if (IS_ERR(di)) {
2837 ret = PTR_ERR(di);
2838 goto err;
2839 }
2840 if (!di) {
2841 ret = -ENOENT;
2842 goto err;
2843 }
2844 leaf = path->nodes[0];
2845 btrfs_dir_item_key_to_cpu(leaf, di, &key);
2846 ret = btrfs_delete_one_dir_name(trans, root, path, di);
2847 if (ret)
2848 goto err;
2849 btrfs_release_path(path);
2850
2851 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
2852 dir_ino, &index);
2853 if (ret) {
2854 printk(KERN_INFO "btrfs failed to delete reference to %.*s, "
2855 "inode %llu parent %llu\n", name_len, name,
2856 (unsigned long long)ino, (unsigned long long)dir_ino);
2857 btrfs_abort_transaction(trans, root, ret);
2858 goto err;
2859 }
2860
2861 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
2862 if (ret) {
2863 btrfs_abort_transaction(trans, root, ret);
2864 goto err;
2865 }
2866
2867 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
2868 inode, dir_ino);
2869 if (ret != 0 && ret != -ENOENT) {
2870 btrfs_abort_transaction(trans, root, ret);
2871 goto err;
2872 }
2873
2874 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
2875 dir, index);
2876 if (ret == -ENOENT)
2877 ret = 0;
2878 err:
2879 btrfs_free_path(path);
2880 if (ret)
2881 goto out;
2882
2883 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
2884 inode_inc_iversion(inode);
2885 inode_inc_iversion(dir);
2886 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
2887 ret = btrfs_update_inode(trans, root, dir);
2888 out:
2889 return ret;
2890 }
2891
2892 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
2893 struct btrfs_root *root,
2894 struct inode *dir, struct inode *inode,
2895 const char *name, int name_len)
2896 {
2897 int ret;
2898 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
2899 if (!ret) {
2900 btrfs_drop_nlink(inode);
2901 ret = btrfs_update_inode(trans, root, inode);
2902 }
2903 return ret;
2904 }
2905
2906
2907 /* helper to check if there is any shared block in the path */
2908 static int check_path_shared(struct btrfs_root *root,
2909 struct btrfs_path *path)
2910 {
2911 struct extent_buffer *eb;
2912 int level;
2913 u64 refs = 1;
2914
2915 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2916 int ret;
2917
2918 if (!path->nodes[level])
2919 break;
2920 eb = path->nodes[level];
2921 if (!btrfs_block_can_be_shared(root, eb))
2922 continue;
2923 ret = btrfs_lookup_extent_info(NULL, root, eb->start, eb->len,
2924 &refs, NULL);
2925 if (refs > 1)
2926 return 1;
2927 }
2928 return 0;
2929 }
2930
2931 /*
2932 * helper to start transaction for unlink and rmdir.
2933 *
2934 * unlink and rmdir are special in btrfs, they do not always free space.
2935 * so in enospc case, we should make sure they will free space before
2936 * allowing them to use the global metadata reservation.
2937 */
2938 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
2939 struct dentry *dentry)
2940 {
2941 struct btrfs_trans_handle *trans;
2942 struct btrfs_root *root = BTRFS_I(dir)->root;
2943 struct btrfs_path *path;
2944 struct btrfs_dir_item *di;
2945 struct inode *inode = dentry->d_inode;
2946 u64 index;
2947 int check_link = 1;
2948 int err = -ENOSPC;
2949 int ret;
2950 u64 ino = btrfs_ino(inode);
2951 u64 dir_ino = btrfs_ino(dir);
2952
2953 /*
2954 * 1 for the possible orphan item
2955 * 1 for the dir item
2956 * 1 for the dir index
2957 * 1 for the inode ref
2958 * 1 for the inode ref in the tree log
2959 * 2 for the dir entries in the log
2960 * 1 for the inode
2961 */
2962 trans = btrfs_start_transaction(root, 8);
2963 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
2964 return trans;
2965
2966 if (ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
2967 return ERR_PTR(-ENOSPC);
2968
2969 /* check if there is someone else holds reference */
2970 if (S_ISDIR(inode->i_mode) && atomic_read(&inode->i_count) > 1)
2971 return ERR_PTR(-ENOSPC);
2972
2973 if (atomic_read(&inode->i_count) > 2)
2974 return ERR_PTR(-ENOSPC);
2975
2976 if (xchg(&root->fs_info->enospc_unlink, 1))
2977 return ERR_PTR(-ENOSPC);
2978
2979 path = btrfs_alloc_path();
2980 if (!path) {
2981 root->fs_info->enospc_unlink = 0;
2982 return ERR_PTR(-ENOMEM);
2983 }
2984
2985 /* 1 for the orphan item */
2986 trans = btrfs_start_transaction(root, 1);
2987 if (IS_ERR(trans)) {
2988 btrfs_free_path(path);
2989 root->fs_info->enospc_unlink = 0;
2990 return trans;
2991 }
2992
2993 path->skip_locking = 1;
2994 path->search_commit_root = 1;
2995
2996 ret = btrfs_lookup_inode(trans, root, path,
2997 &BTRFS_I(dir)->location, 0);
2998 if (ret < 0) {
2999 err = ret;
3000 goto out;
3001 }
3002 if (ret == 0) {
3003 if (check_path_shared(root, path))
3004 goto out;
3005 } else {
3006 check_link = 0;
3007 }
3008 btrfs_release_path(path);
3009
3010 ret = btrfs_lookup_inode(trans, root, path,
3011 &BTRFS_I(inode)->location, 0);
3012 if (ret < 0) {
3013 err = ret;
3014 goto out;
3015 }
3016 if (ret == 0) {
3017 if (check_path_shared(root, path))
3018 goto out;
3019 } else {
3020 check_link = 0;
3021 }
3022 btrfs_release_path(path);
3023
3024 if (ret == 0 && S_ISREG(inode->i_mode)) {
3025 ret = btrfs_lookup_file_extent(trans, root, path,
3026 ino, (u64)-1, 0);
3027 if (ret < 0) {
3028 err = ret;
3029 goto out;
3030 }
3031 BUG_ON(ret == 0); /* Corruption */
3032 if (check_path_shared(root, path))
3033 goto out;
3034 btrfs_release_path(path);
3035 }
3036
3037 if (!check_link) {
3038 err = 0;
3039 goto out;
3040 }
3041
3042 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3043 dentry->d_name.name, dentry->d_name.len, 0);
3044 if (IS_ERR(di)) {
3045 err = PTR_ERR(di);
3046 goto out;
3047 }
3048 if (di) {
3049 if (check_path_shared(root, path))
3050 goto out;
3051 } else {
3052 err = 0;
3053 goto out;
3054 }
3055 btrfs_release_path(path);
3056
3057 ret = btrfs_get_inode_ref_index(trans, root, path, dentry->d_name.name,
3058 dentry->d_name.len, ino, dir_ino, 0,
3059 &index);
3060 if (ret) {
3061 err = ret;
3062 goto out;
3063 }
3064
3065 if (check_path_shared(root, path))
3066 goto out;
3067
3068 btrfs_release_path(path);
3069
3070 /*
3071 * This is a commit root search, if we can lookup inode item and other
3072 * relative items in the commit root, it means the transaction of
3073 * dir/file creation has been committed, and the dir index item that we
3074 * delay to insert has also been inserted into the commit root. So
3075 * we needn't worry about the delayed insertion of the dir index item
3076 * here.
3077 */
3078 di = btrfs_lookup_dir_index_item(trans, root, path, dir_ino, index,
3079 dentry->d_name.name, dentry->d_name.len, 0);
3080 if (IS_ERR(di)) {
3081 err = PTR_ERR(di);
3082 goto out;
3083 }
3084 BUG_ON(ret == -ENOENT);
3085 if (check_path_shared(root, path))
3086 goto out;
3087
3088 err = 0;
3089 out:
3090 btrfs_free_path(path);
3091 /* Migrate the orphan reservation over */
3092 if (!err)
3093 err = btrfs_block_rsv_migrate(trans->block_rsv,
3094 &root->fs_info->global_block_rsv,
3095 trans->bytes_reserved);
3096
3097 if (err) {
3098 btrfs_end_transaction(trans, root);
3099 root->fs_info->enospc_unlink = 0;
3100 return ERR_PTR(err);
3101 }
3102
3103 trans->block_rsv = &root->fs_info->global_block_rsv;
3104 return trans;
3105 }
3106
3107 static void __unlink_end_trans(struct btrfs_trans_handle *trans,
3108 struct btrfs_root *root)
3109 {
3110 if (trans->block_rsv->type == BTRFS_BLOCK_RSV_GLOBAL) {
3111 btrfs_block_rsv_release(root, trans->block_rsv,
3112 trans->bytes_reserved);
3113 trans->block_rsv = &root->fs_info->trans_block_rsv;
3114 BUG_ON(!root->fs_info->enospc_unlink);
3115 root->fs_info->enospc_unlink = 0;
3116 }
3117 btrfs_end_transaction(trans, root);
3118 }
3119
3120 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
3121 {
3122 struct btrfs_root *root = BTRFS_I(dir)->root;
3123 struct btrfs_trans_handle *trans;
3124 struct inode *inode = dentry->d_inode;
3125 int ret;
3126
3127 trans = __unlink_start_trans(dir, dentry);
3128 if (IS_ERR(trans))
3129 return PTR_ERR(trans);
3130
3131 btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0);
3132
3133 ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3134 dentry->d_name.name, dentry->d_name.len);
3135 if (ret)
3136 goto out;
3137
3138 if (inode->i_nlink == 0) {
3139 ret = btrfs_orphan_add(trans, inode);
3140 if (ret)
3141 goto out;
3142 }
3143
3144 out:
3145 __unlink_end_trans(trans, root);
3146 btrfs_btree_balance_dirty(root);
3147 return ret;
3148 }
3149
3150 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
3151 struct btrfs_root *root,
3152 struct inode *dir, u64 objectid,
3153 const char *name, int name_len)
3154 {
3155 struct btrfs_path *path;
3156 struct extent_buffer *leaf;
3157 struct btrfs_dir_item *di;
3158 struct btrfs_key key;
3159 u64 index;
3160 int ret;
3161 u64 dir_ino = btrfs_ino(dir);
3162
3163 path = btrfs_alloc_path();
3164 if (!path)
3165 return -ENOMEM;
3166
3167 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3168 name, name_len, -1);
3169 if (IS_ERR_OR_NULL(di)) {
3170 if (!di)
3171 ret = -ENOENT;
3172 else
3173 ret = PTR_ERR(di);
3174 goto out;
3175 }
3176
3177 leaf = path->nodes[0];
3178 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3179 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
3180 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3181 if (ret) {
3182 btrfs_abort_transaction(trans, root, ret);
3183 goto out;
3184 }
3185 btrfs_release_path(path);
3186
3187 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
3188 objectid, root->root_key.objectid,
3189 dir_ino, &index, name, name_len);
3190 if (ret < 0) {
3191 if (ret != -ENOENT) {
3192 btrfs_abort_transaction(trans, root, ret);
3193 goto out;
3194 }
3195 di = btrfs_search_dir_index_item(root, path, dir_ino,
3196 name, name_len);
3197 if (IS_ERR_OR_NULL(di)) {
3198 if (!di)
3199 ret = -ENOENT;
3200 else
3201 ret = PTR_ERR(di);
3202 btrfs_abort_transaction(trans, root, ret);
3203 goto out;
3204 }
3205
3206 leaf = path->nodes[0];
3207 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3208 btrfs_release_path(path);
3209 index = key.offset;
3210 }
3211 btrfs_release_path(path);
3212
3213 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3214 if (ret) {
3215 btrfs_abort_transaction(trans, root, ret);
3216 goto out;
3217 }
3218
3219 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3220 inode_inc_iversion(dir);
3221 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3222 ret = btrfs_update_inode_fallback(trans, root, dir);
3223 if (ret)
3224 btrfs_abort_transaction(trans, root, ret);
3225 out:
3226 btrfs_free_path(path);
3227 return ret;
3228 }
3229
3230 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
3231 {
3232 struct inode *inode = dentry->d_inode;
3233 int err = 0;
3234 struct btrfs_root *root = BTRFS_I(dir)->root;
3235 struct btrfs_trans_handle *trans;
3236
3237 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
3238 return -ENOTEMPTY;
3239 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
3240 return -EPERM;
3241
3242 trans = __unlink_start_trans(dir, dentry);
3243 if (IS_ERR(trans))
3244 return PTR_ERR(trans);
3245
3246 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
3247 err = btrfs_unlink_subvol(trans, root, dir,
3248 BTRFS_I(inode)->location.objectid,
3249 dentry->d_name.name,
3250 dentry->d_name.len);
3251 goto out;
3252 }
3253
3254 err = btrfs_orphan_add(trans, inode);
3255 if (err)
3256 goto out;
3257
3258 /* now the directory is empty */
3259 err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3260 dentry->d_name.name, dentry->d_name.len);
3261 if (!err)
3262 btrfs_i_size_write(inode, 0);
3263 out:
3264 __unlink_end_trans(trans, root);
3265 btrfs_btree_balance_dirty(root);
3266
3267 return err;
3268 }
3269
3270 /*
3271 * this can truncate away extent items, csum items and directory items.
3272 * It starts at a high offset and removes keys until it can't find
3273 * any higher than new_size
3274 *
3275 * csum items that cross the new i_size are truncated to the new size
3276 * as well.
3277 *
3278 * min_type is the minimum key type to truncate down to. If set to 0, this
3279 * will kill all the items on this inode, including the INODE_ITEM_KEY.
3280 */
3281 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
3282 struct btrfs_root *root,
3283 struct inode *inode,
3284 u64 new_size, u32 min_type)
3285 {
3286 struct btrfs_path *path;
3287 struct extent_buffer *leaf;
3288 struct btrfs_file_extent_item *fi;
3289 struct btrfs_key key;
3290 struct btrfs_key found_key;
3291 u64 extent_start = 0;
3292 u64 extent_num_bytes = 0;
3293 u64 extent_offset = 0;
3294 u64 item_end = 0;
3295 u64 mask = root->sectorsize - 1;
3296 u32 found_type = (u8)-1;
3297 int found_extent;
3298 int del_item;
3299 int pending_del_nr = 0;
3300 int pending_del_slot = 0;
3301 int extent_type = -1;
3302 int ret;
3303 int err = 0;
3304 u64 ino = btrfs_ino(inode);
3305
3306 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
3307
3308 path = btrfs_alloc_path();
3309 if (!path)
3310 return -ENOMEM;
3311 path->reada = -1;
3312
3313 /*
3314 * We want to drop from the next block forward in case this new size is
3315 * not block aligned since we will be keeping the last block of the
3316 * extent just the way it is.
3317 */
3318 if (root->ref_cows || root == root->fs_info->tree_root)
3319 btrfs_drop_extent_cache(inode, (new_size + mask) & (~mask), (u64)-1, 0);
3320
3321 /*
3322 * This function is also used to drop the items in the log tree before
3323 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
3324 * it is used to drop the loged items. So we shouldn't kill the delayed
3325 * items.
3326 */
3327 if (min_type == 0 && root == BTRFS_I(inode)->root)
3328 btrfs_kill_delayed_inode_items(inode);
3329
3330 key.objectid = ino;
3331 key.offset = (u64)-1;
3332 key.type = (u8)-1;
3333
3334 search_again:
3335 path->leave_spinning = 1;
3336 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3337 if (ret < 0) {
3338 err = ret;
3339 goto out;
3340 }
3341
3342 if (ret > 0) {
3343 /* there are no items in the tree for us to truncate, we're
3344 * done
3345 */
3346 if (path->slots[0] == 0)
3347 goto out;
3348 path->slots[0]--;
3349 }
3350
3351 while (1) {
3352 fi = NULL;
3353 leaf = path->nodes[0];
3354 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3355 found_type = btrfs_key_type(&found_key);
3356
3357 if (found_key.objectid != ino)
3358 break;
3359
3360 if (found_type < min_type)
3361 break;
3362
3363 item_end = found_key.offset;
3364 if (found_type == BTRFS_EXTENT_DATA_KEY) {
3365 fi = btrfs_item_ptr(leaf, path->slots[0],
3366 struct btrfs_file_extent_item);
3367 extent_type = btrfs_file_extent_type(leaf, fi);
3368 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
3369 item_end +=
3370 btrfs_file_extent_num_bytes(leaf, fi);
3371 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
3372 item_end += btrfs_file_extent_inline_len(leaf,
3373 fi);
3374 }
3375 item_end--;
3376 }
3377 if (found_type > min_type) {
3378 del_item = 1;
3379 } else {
3380 if (item_end < new_size)
3381 break;
3382 if (found_key.offset >= new_size)
3383 del_item = 1;
3384 else
3385 del_item = 0;
3386 }
3387 found_extent = 0;
3388 /* FIXME, shrink the extent if the ref count is only 1 */
3389 if (found_type != BTRFS_EXTENT_DATA_KEY)
3390 goto delete;
3391
3392 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
3393 u64 num_dec;
3394 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
3395 if (!del_item) {
3396 u64 orig_num_bytes =
3397 btrfs_file_extent_num_bytes(leaf, fi);
3398 extent_num_bytes = new_size -
3399 found_key.offset + root->sectorsize - 1;
3400 extent_num_bytes = extent_num_bytes &
3401 ~((u64)root->sectorsize - 1);
3402 btrfs_set_file_extent_num_bytes(leaf, fi,
3403 extent_num_bytes);
3404 num_dec = (orig_num_bytes -
3405 extent_num_bytes);
3406 if (root->ref_cows && extent_start != 0)
3407 inode_sub_bytes(inode, num_dec);
3408 btrfs_mark_buffer_dirty(leaf);
3409 } else {
3410 extent_num_bytes =
3411 btrfs_file_extent_disk_num_bytes(leaf,
3412 fi);
3413 extent_offset = found_key.offset -
3414 btrfs_file_extent_offset(leaf, fi);
3415
3416 /* FIXME blocksize != 4096 */
3417 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
3418 if (extent_start != 0) {
3419 found_extent = 1;
3420 if (root->ref_cows)
3421 inode_sub_bytes(inode, num_dec);
3422 }
3423 }
3424 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
3425 /*
3426 * we can't truncate inline items that have had
3427 * special encodings
3428 */
3429 if (!del_item &&
3430 btrfs_file_extent_compression(leaf, fi) == 0 &&
3431 btrfs_file_extent_encryption(leaf, fi) == 0 &&
3432 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
3433 u32 size = new_size - found_key.offset;
3434
3435 if (root->ref_cows) {
3436 inode_sub_bytes(inode, item_end + 1 -
3437 new_size);
3438 }
3439 size =
3440 btrfs_file_extent_calc_inline_size(size);
3441 btrfs_truncate_item(trans, root, path,
3442 size, 1);
3443 } else if (root->ref_cows) {
3444 inode_sub_bytes(inode, item_end + 1 -
3445 found_key.offset);
3446 }
3447 }
3448 delete:
3449 if (del_item) {
3450 if (!pending_del_nr) {
3451 /* no pending yet, add ourselves */
3452 pending_del_slot = path->slots[0];
3453 pending_del_nr = 1;
3454 } else if (pending_del_nr &&
3455 path->slots[0] + 1 == pending_del_slot) {
3456 /* hop on the pending chunk */
3457 pending_del_nr++;
3458 pending_del_slot = path->slots[0];
3459 } else {
3460 BUG();
3461 }
3462 } else {
3463 break;
3464 }
3465 if (found_extent && (root->ref_cows ||
3466 root == root->fs_info->tree_root)) {
3467 btrfs_set_path_blocking(path);
3468 ret = btrfs_free_extent(trans, root, extent_start,
3469 extent_num_bytes, 0,
3470 btrfs_header_owner(leaf),
3471 ino, extent_offset, 0);
3472 BUG_ON(ret);
3473 }
3474
3475 if (found_type == BTRFS_INODE_ITEM_KEY)
3476 break;
3477
3478 if (path->slots[0] == 0 ||
3479 path->slots[0] != pending_del_slot) {
3480 if (pending_del_nr) {
3481 ret = btrfs_del_items(trans, root, path,
3482 pending_del_slot,
3483 pending_del_nr);
3484 if (ret) {
3485 btrfs_abort_transaction(trans,
3486 root, ret);
3487 goto error;
3488 }
3489 pending_del_nr = 0;
3490 }
3491 btrfs_release_path(path);
3492 goto search_again;
3493 } else {
3494 path->slots[0]--;
3495 }
3496 }
3497 out:
3498 if (pending_del_nr) {
3499 ret = btrfs_del_items(trans, root, path, pending_del_slot,
3500 pending_del_nr);
3501 if (ret)
3502 btrfs_abort_transaction(trans, root, ret);
3503 }
3504 error:
3505 btrfs_free_path(path);
3506 return err;
3507 }
3508
3509 /*
3510 * btrfs_truncate_page - read, zero a chunk and write a page
3511 * @inode - inode that we're zeroing
3512 * @from - the offset to start zeroing
3513 * @len - the length to zero, 0 to zero the entire range respective to the
3514 * offset
3515 * @front - zero up to the offset instead of from the offset on
3516 *
3517 * This will find the page for the "from" offset and cow the page and zero the
3518 * part we want to zero. This is used with truncate and hole punching.
3519 */
3520 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
3521 int front)
3522 {
3523 struct address_space *mapping = inode->i_mapping;
3524 struct btrfs_root *root = BTRFS_I(inode)->root;
3525 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3526 struct btrfs_ordered_extent *ordered;
3527 struct extent_state *cached_state = NULL;
3528 char *kaddr;
3529 u32 blocksize = root->sectorsize;
3530 pgoff_t index = from >> PAGE_CACHE_SHIFT;
3531 unsigned offset = from & (PAGE_CACHE_SIZE-1);
3532 struct page *page;
3533 gfp_t mask = btrfs_alloc_write_mask(mapping);
3534 int ret = 0;
3535 u64 page_start;
3536 u64 page_end;
3537
3538 if ((offset & (blocksize - 1)) == 0 &&
3539 (!len || ((len & (blocksize - 1)) == 0)))
3540 goto out;
3541 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
3542 if (ret)
3543 goto out;
3544
3545 again:
3546 page = find_or_create_page(mapping, index, mask);
3547 if (!page) {
3548 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
3549 ret = -ENOMEM;
3550 goto out;
3551 }
3552
3553 page_start = page_offset(page);
3554 page_end = page_start + PAGE_CACHE_SIZE - 1;
3555
3556 if (!PageUptodate(page)) {
3557 ret = btrfs_readpage(NULL, page);
3558 lock_page(page);
3559 if (page->mapping != mapping) {
3560 unlock_page(page);
3561 page_cache_release(page);
3562 goto again;
3563 }
3564 if (!PageUptodate(page)) {
3565 ret = -EIO;
3566 goto out_unlock;
3567 }
3568 }
3569 wait_on_page_writeback(page);
3570
3571 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
3572 set_page_extent_mapped(page);
3573
3574 ordered = btrfs_lookup_ordered_extent(inode, page_start);
3575 if (ordered) {
3576 unlock_extent_cached(io_tree, page_start, page_end,
3577 &cached_state, GFP_NOFS);
3578 unlock_page(page);
3579 page_cache_release(page);
3580 btrfs_start_ordered_extent(inode, ordered, 1);
3581 btrfs_put_ordered_extent(ordered);
3582 goto again;
3583 }
3584
3585 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
3586 EXTENT_DIRTY | EXTENT_DELALLOC |
3587 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
3588 0, 0, &cached_state, GFP_NOFS);
3589
3590 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
3591 &cached_state);
3592 if (ret) {
3593 unlock_extent_cached(io_tree, page_start, page_end,
3594 &cached_state, GFP_NOFS);
3595 goto out_unlock;
3596 }
3597
3598 if (offset != PAGE_CACHE_SIZE) {
3599 if (!len)
3600 len = PAGE_CACHE_SIZE - offset;
3601 kaddr = kmap(page);
3602 if (front)
3603 memset(kaddr, 0, offset);
3604 else
3605 memset(kaddr + offset, 0, len);
3606 flush_dcache_page(page);
3607 kunmap(page);
3608 }
3609 ClearPageChecked(page);
3610 set_page_dirty(page);
3611 unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
3612 GFP_NOFS);
3613
3614 out_unlock:
3615 if (ret)
3616 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
3617 unlock_page(page);
3618 page_cache_release(page);
3619 out:
3620 return ret;
3621 }
3622
3623 /*
3624 * This function puts in dummy file extents for the area we're creating a hole
3625 * for. So if we are truncating this file to a larger size we need to insert
3626 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
3627 * the range between oldsize and size
3628 */
3629 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
3630 {
3631 struct btrfs_trans_handle *trans;
3632 struct btrfs_root *root = BTRFS_I(inode)->root;
3633 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3634 struct extent_map *em = NULL;
3635 struct extent_state *cached_state = NULL;
3636 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
3637 u64 mask = root->sectorsize - 1;
3638 u64 hole_start = (oldsize + mask) & ~mask;
3639 u64 block_end = (size + mask) & ~mask;
3640 u64 last_byte;
3641 u64 cur_offset;
3642 u64 hole_size;
3643 int err = 0;
3644
3645 if (size <= hole_start)
3646 return 0;
3647
3648 while (1) {
3649 struct btrfs_ordered_extent *ordered;
3650 btrfs_wait_ordered_range(inode, hole_start,
3651 block_end - hole_start);
3652 lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
3653 &cached_state);
3654 ordered = btrfs_lookup_ordered_extent(inode, hole_start);
3655 if (!ordered)
3656 break;
3657 unlock_extent_cached(io_tree, hole_start, block_end - 1,
3658 &cached_state, GFP_NOFS);
3659 btrfs_put_ordered_extent(ordered);
3660 }
3661
3662 cur_offset = hole_start;
3663 while (1) {
3664 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
3665 block_end - cur_offset, 0);
3666 if (IS_ERR(em)) {
3667 err = PTR_ERR(em);
3668 break;
3669 }
3670 last_byte = min(extent_map_end(em), block_end);
3671 last_byte = (last_byte + mask) & ~mask;
3672 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
3673 struct extent_map *hole_em;
3674 hole_size = last_byte - cur_offset;
3675
3676 trans = btrfs_start_transaction(root, 3);
3677 if (IS_ERR(trans)) {
3678 err = PTR_ERR(trans);
3679 break;
3680 }
3681
3682 err = btrfs_drop_extents(trans, root, inode,
3683 cur_offset,
3684 cur_offset + hole_size, 1);
3685 if (err) {
3686 btrfs_abort_transaction(trans, root, err);
3687 btrfs_end_transaction(trans, root);
3688 break;
3689 }
3690
3691 err = btrfs_insert_file_extent(trans, root,
3692 btrfs_ino(inode), cur_offset, 0,
3693 0, hole_size, 0, hole_size,
3694 0, 0, 0);
3695 if (err) {
3696 btrfs_abort_transaction(trans, root, err);
3697 btrfs_end_transaction(trans, root);
3698 break;
3699 }
3700
3701 btrfs_drop_extent_cache(inode, cur_offset,
3702 cur_offset + hole_size - 1, 0);
3703 hole_em = alloc_extent_map();
3704 if (!hole_em) {
3705 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3706 &BTRFS_I(inode)->runtime_flags);
3707 goto next;
3708 }
3709 hole_em->start = cur_offset;
3710 hole_em->len = hole_size;
3711 hole_em->orig_start = cur_offset;
3712
3713 hole_em->block_start = EXTENT_MAP_HOLE;
3714 hole_em->block_len = 0;
3715 hole_em->orig_block_len = 0;
3716 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
3717 hole_em->compress_type = BTRFS_COMPRESS_NONE;
3718 hole_em->generation = trans->transid;
3719
3720 while (1) {
3721 write_lock(&em_tree->lock);
3722 err = add_extent_mapping(em_tree, hole_em);
3723 if (!err)
3724 list_move(&hole_em->list,
3725 &em_tree->modified_extents);
3726 write_unlock(&em_tree->lock);
3727 if (err != -EEXIST)
3728 break;
3729 btrfs_drop_extent_cache(inode, cur_offset,
3730 cur_offset +
3731 hole_size - 1, 0);
3732 }
3733 free_extent_map(hole_em);
3734 next:
3735 btrfs_update_inode(trans, root, inode);
3736 btrfs_end_transaction(trans, root);
3737 }
3738 free_extent_map(em);
3739 em = NULL;
3740 cur_offset = last_byte;
3741 if (cur_offset >= block_end)
3742 break;
3743 }
3744
3745 free_extent_map(em);
3746 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
3747 GFP_NOFS);
3748 return err;
3749 }
3750
3751 static int btrfs_setsize(struct inode *inode, loff_t newsize)
3752 {
3753 struct btrfs_root *root = BTRFS_I(inode)->root;
3754 struct btrfs_trans_handle *trans;
3755 loff_t oldsize = i_size_read(inode);
3756 int ret;
3757
3758 if (newsize == oldsize)
3759 return 0;
3760
3761 if (newsize > oldsize) {
3762 truncate_pagecache(inode, oldsize, newsize);
3763 ret = btrfs_cont_expand(inode, oldsize, newsize);
3764 if (ret)
3765 return ret;
3766
3767 trans = btrfs_start_transaction(root, 1);
3768 if (IS_ERR(trans))
3769 return PTR_ERR(trans);
3770
3771 i_size_write(inode, newsize);
3772 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
3773 ret = btrfs_update_inode(trans, root, inode);
3774 btrfs_end_transaction(trans, root);
3775 } else {
3776
3777 /*
3778 * We're truncating a file that used to have good data down to
3779 * zero. Make sure it gets into the ordered flush list so that
3780 * any new writes get down to disk quickly.
3781 */
3782 if (newsize == 0)
3783 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
3784 &BTRFS_I(inode)->runtime_flags);
3785
3786 /* we don't support swapfiles, so vmtruncate shouldn't fail */
3787 truncate_setsize(inode, newsize);
3788 ret = btrfs_truncate(inode);
3789 }
3790
3791 return ret;
3792 }
3793
3794 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
3795 {
3796 struct inode *inode = dentry->d_inode;
3797 struct btrfs_root *root = BTRFS_I(inode)->root;
3798 int err;
3799
3800 if (btrfs_root_readonly(root))
3801 return -EROFS;
3802
3803 err = inode_change_ok(inode, attr);
3804 if (err)
3805 return err;
3806
3807 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
3808 err = btrfs_setsize(inode, attr->ia_size);
3809 if (err)
3810 return err;
3811 }
3812
3813 if (attr->ia_valid) {
3814 setattr_copy(inode, attr);
3815 inode_inc_iversion(inode);
3816 err = btrfs_dirty_inode(inode);
3817
3818 if (!err && attr->ia_valid & ATTR_MODE)
3819 err = btrfs_acl_chmod(inode);
3820 }
3821
3822 return err;
3823 }
3824
3825 void btrfs_evict_inode(struct inode *inode)
3826 {
3827 struct btrfs_trans_handle *trans;
3828 struct btrfs_root *root = BTRFS_I(inode)->root;
3829 struct btrfs_block_rsv *rsv, *global_rsv;
3830 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
3831 int ret;
3832
3833 trace_btrfs_inode_evict(inode);
3834
3835 truncate_inode_pages(&inode->i_data, 0);
3836 if (inode->i_nlink && (btrfs_root_refs(&root->root_item) != 0 ||
3837 btrfs_is_free_space_inode(inode)))
3838 goto no_delete;
3839
3840 if (is_bad_inode(inode)) {
3841 btrfs_orphan_del(NULL, inode);
3842 goto no_delete;
3843 }
3844 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
3845 btrfs_wait_ordered_range(inode, 0, (u64)-1);
3846
3847 if (root->fs_info->log_root_recovering) {
3848 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3849 &BTRFS_I(inode)->runtime_flags));
3850 goto no_delete;
3851 }
3852
3853 if (inode->i_nlink > 0) {
3854 BUG_ON(btrfs_root_refs(&root->root_item) != 0);
3855 goto no_delete;
3856 }
3857
3858 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
3859 if (!rsv) {
3860 btrfs_orphan_del(NULL, inode);
3861 goto no_delete;
3862 }
3863 rsv->size = min_size;
3864 rsv->failfast = 1;
3865 global_rsv = &root->fs_info->global_block_rsv;
3866
3867 btrfs_i_size_write(inode, 0);
3868
3869 /*
3870 * This is a bit simpler than btrfs_truncate since we've already
3871 * reserved our space for our orphan item in the unlink, so we just
3872 * need to reserve some slack space in case we add bytes and update
3873 * inode item when doing the truncate.
3874 */
3875 while (1) {
3876 ret = btrfs_block_rsv_refill(root, rsv, min_size,
3877 BTRFS_RESERVE_FLUSH_LIMIT);
3878
3879 /*
3880 * Try and steal from the global reserve since we will
3881 * likely not use this space anyway, we want to try as
3882 * hard as possible to get this to work.
3883 */
3884 if (ret)
3885 ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size);
3886
3887 if (ret) {
3888 printk(KERN_WARNING "Could not get space for a "
3889 "delete, will truncate on mount %d\n", ret);
3890 btrfs_orphan_del(NULL, inode);
3891 btrfs_free_block_rsv(root, rsv);
3892 goto no_delete;
3893 }
3894
3895 trans = btrfs_start_transaction_lflush(root, 1);
3896 if (IS_ERR(trans)) {
3897 btrfs_orphan_del(NULL, inode);
3898 btrfs_free_block_rsv(root, rsv);
3899 goto no_delete;
3900 }
3901
3902 trans->block_rsv = rsv;
3903
3904 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
3905 if (ret != -ENOSPC)
3906 break;
3907
3908 trans->block_rsv = &root->fs_info->trans_block_rsv;
3909 ret = btrfs_update_inode(trans, root, inode);
3910 BUG_ON(ret);
3911
3912 btrfs_end_transaction(trans, root);
3913 trans = NULL;
3914 btrfs_btree_balance_dirty(root);
3915 }
3916
3917 btrfs_free_block_rsv(root, rsv);
3918
3919 if (ret == 0) {
3920 trans->block_rsv = root->orphan_block_rsv;
3921 ret = btrfs_orphan_del(trans, inode);
3922 BUG_ON(ret);
3923 }
3924
3925 trans->block_rsv = &root->fs_info->trans_block_rsv;
3926 if (!(root == root->fs_info->tree_root ||
3927 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
3928 btrfs_return_ino(root, btrfs_ino(inode));
3929
3930 btrfs_end_transaction(trans, root);
3931 btrfs_btree_balance_dirty(root);
3932 no_delete:
3933 clear_inode(inode);
3934 return;
3935 }
3936
3937 /*
3938 * this returns the key found in the dir entry in the location pointer.
3939 * If no dir entries were found, location->objectid is 0.
3940 */
3941 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
3942 struct btrfs_key *location)
3943 {
3944 const char *name = dentry->d_name.name;
3945 int namelen = dentry->d_name.len;
3946 struct btrfs_dir_item *di;
3947 struct btrfs_path *path;
3948 struct btrfs_root *root = BTRFS_I(dir)->root;
3949 int ret = 0;
3950
3951 path = btrfs_alloc_path();
3952 if (!path)
3953 return -ENOMEM;
3954
3955 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
3956 namelen, 0);
3957 if (IS_ERR(di))
3958 ret = PTR_ERR(di);
3959
3960 if (IS_ERR_OR_NULL(di))
3961 goto out_err;
3962
3963 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
3964 out:
3965 btrfs_free_path(path);
3966 return ret;
3967 out_err:
3968 location->objectid = 0;
3969 goto out;
3970 }
3971
3972 /*
3973 * when we hit a tree root in a directory, the btrfs part of the inode
3974 * needs to be changed to reflect the root directory of the tree root. This
3975 * is kind of like crossing a mount point.
3976 */
3977 static int fixup_tree_root_location(struct btrfs_root *root,
3978 struct inode *dir,
3979 struct dentry *dentry,
3980 struct btrfs_key *location,
3981 struct btrfs_root **sub_root)
3982 {
3983 struct btrfs_path *path;
3984 struct btrfs_root *new_root;
3985 struct btrfs_root_ref *ref;
3986 struct extent_buffer *leaf;
3987 int ret;
3988 int err = 0;
3989
3990 path = btrfs_alloc_path();
3991 if (!path) {
3992 err = -ENOMEM;
3993 goto out;
3994 }
3995
3996 err = -ENOENT;
3997 ret = btrfs_find_root_ref(root->fs_info->tree_root, path,
3998 BTRFS_I(dir)->root->root_key.objectid,
3999 location->objectid);
4000 if (ret) {
4001 if (ret < 0)
4002 err = ret;
4003 goto out;
4004 }
4005
4006 leaf = path->nodes[0];
4007 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
4008 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
4009 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
4010 goto out;
4011
4012 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
4013 (unsigned long)(ref + 1),
4014 dentry->d_name.len);
4015 if (ret)
4016 goto out;
4017
4018 btrfs_release_path(path);
4019
4020 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
4021 if (IS_ERR(new_root)) {
4022 err = PTR_ERR(new_root);
4023 goto out;
4024 }
4025
4026 if (btrfs_root_refs(&new_root->root_item) == 0) {
4027 err = -ENOENT;
4028 goto out;
4029 }
4030
4031 *sub_root = new_root;
4032 location->objectid = btrfs_root_dirid(&new_root->root_item);
4033 location->type = BTRFS_INODE_ITEM_KEY;
4034 location->offset = 0;
4035 err = 0;
4036 out:
4037 btrfs_free_path(path);
4038 return err;
4039 }
4040
4041 static void inode_tree_add(struct inode *inode)
4042 {
4043 struct btrfs_root *root = BTRFS_I(inode)->root;
4044 struct btrfs_inode *entry;
4045 struct rb_node **p;
4046 struct rb_node *parent;
4047 u64 ino = btrfs_ino(inode);
4048 again:
4049 p = &root->inode_tree.rb_node;
4050 parent = NULL;
4051
4052 if (inode_unhashed(inode))
4053 return;
4054
4055 spin_lock(&root->inode_lock);
4056 while (*p) {
4057 parent = *p;
4058 entry = rb_entry(parent, struct btrfs_inode, rb_node);
4059
4060 if (ino < btrfs_ino(&entry->vfs_inode))
4061 p = &parent->rb_left;
4062 else if (ino > btrfs_ino(&entry->vfs_inode))
4063 p = &parent->rb_right;
4064 else {
4065 WARN_ON(!(entry->vfs_inode.i_state &
4066 (I_WILL_FREE | I_FREEING)));
4067 rb_erase(parent, &root->inode_tree);
4068 RB_CLEAR_NODE(parent);
4069 spin_unlock(&root->inode_lock);
4070 goto again;
4071 }
4072 }
4073 rb_link_node(&BTRFS_I(inode)->rb_node, parent, p);
4074 rb_insert_color(&BTRFS_I(inode)->rb_node, &root->inode_tree);
4075 spin_unlock(&root->inode_lock);
4076 }
4077
4078 static void inode_tree_del(struct inode *inode)
4079 {
4080 struct btrfs_root *root = BTRFS_I(inode)->root;
4081 int empty = 0;
4082
4083 spin_lock(&root->inode_lock);
4084 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
4085 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
4086 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
4087 empty = RB_EMPTY_ROOT(&root->inode_tree);
4088 }
4089 spin_unlock(&root->inode_lock);
4090
4091 /*
4092 * Free space cache has inodes in the tree root, but the tree root has a
4093 * root_refs of 0, so this could end up dropping the tree root as a
4094 * snapshot, so we need the extra !root->fs_info->tree_root check to
4095 * make sure we don't drop it.
4096 */
4097 if (empty && btrfs_root_refs(&root->root_item) == 0 &&
4098 root != root->fs_info->tree_root) {
4099 synchronize_srcu(&root->fs_info->subvol_srcu);
4100 spin_lock(&root->inode_lock);
4101 empty = RB_EMPTY_ROOT(&root->inode_tree);
4102 spin_unlock(&root->inode_lock);
4103 if (empty)
4104 btrfs_add_dead_root(root);
4105 }
4106 }
4107
4108 void btrfs_invalidate_inodes(struct btrfs_root *root)
4109 {
4110 struct rb_node *node;
4111 struct rb_node *prev;
4112 struct btrfs_inode *entry;
4113 struct inode *inode;
4114 u64 objectid = 0;
4115
4116 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
4117
4118 spin_lock(&root->inode_lock);
4119 again:
4120 node = root->inode_tree.rb_node;
4121 prev = NULL;
4122 while (node) {
4123 prev = node;
4124 entry = rb_entry(node, struct btrfs_inode, rb_node);
4125
4126 if (objectid < btrfs_ino(&entry->vfs_inode))
4127 node = node->rb_left;
4128 else if (objectid > btrfs_ino(&entry->vfs_inode))
4129 node = node->rb_right;
4130 else
4131 break;
4132 }
4133 if (!node) {
4134 while (prev) {
4135 entry = rb_entry(prev, struct btrfs_inode, rb_node);
4136 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
4137 node = prev;
4138 break;
4139 }
4140 prev = rb_next(prev);
4141 }
4142 }
4143 while (node) {
4144 entry = rb_entry(node, struct btrfs_inode, rb_node);
4145 objectid = btrfs_ino(&entry->vfs_inode) + 1;
4146 inode = igrab(&entry->vfs_inode);
4147 if (inode) {
4148 spin_unlock(&root->inode_lock);
4149 if (atomic_read(&inode->i_count) > 1)
4150 d_prune_aliases(inode);
4151 /*
4152 * btrfs_drop_inode will have it removed from
4153 * the inode cache when its usage count
4154 * hits zero.
4155 */
4156 iput(inode);
4157 cond_resched();
4158 spin_lock(&root->inode_lock);
4159 goto again;
4160 }
4161
4162 if (cond_resched_lock(&root->inode_lock))
4163 goto again;
4164
4165 node = rb_next(node);
4166 }
4167 spin_unlock(&root->inode_lock);
4168 }
4169
4170 static int btrfs_init_locked_inode(struct inode *inode, void *p)
4171 {
4172 struct btrfs_iget_args *args = p;
4173 inode->i_ino = args->ino;
4174 BTRFS_I(inode)->root = args->root;
4175 return 0;
4176 }
4177
4178 static int btrfs_find_actor(struct inode *inode, void *opaque)
4179 {
4180 struct btrfs_iget_args *args = opaque;
4181 return args->ino == btrfs_ino(inode) &&
4182 args->root == BTRFS_I(inode)->root;
4183 }
4184
4185 static struct inode *btrfs_iget_locked(struct super_block *s,
4186 u64 objectid,
4187 struct btrfs_root *root)
4188 {
4189 struct inode *inode;
4190 struct btrfs_iget_args args;
4191 args.ino = objectid;
4192 args.root = root;
4193
4194 inode = iget5_locked(s, objectid, btrfs_find_actor,
4195 btrfs_init_locked_inode,
4196 (void *)&args);
4197 return inode;
4198 }
4199
4200 /* Get an inode object given its location and corresponding root.
4201 * Returns in *is_new if the inode was read from disk
4202 */
4203 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
4204 struct btrfs_root *root, int *new)
4205 {
4206 struct inode *inode;
4207
4208 inode = btrfs_iget_locked(s, location->objectid, root);
4209 if (!inode)
4210 return ERR_PTR(-ENOMEM);
4211
4212 if (inode->i_state & I_NEW) {
4213 BTRFS_I(inode)->root = root;
4214 memcpy(&BTRFS_I(inode)->location, location, sizeof(*location));
4215 btrfs_read_locked_inode(inode);
4216 if (!is_bad_inode(inode)) {
4217 inode_tree_add(inode);
4218 unlock_new_inode(inode);
4219 if (new)
4220 *new = 1;
4221 } else {
4222 unlock_new_inode(inode);
4223 iput(inode);
4224 inode = ERR_PTR(-ESTALE);
4225 }
4226 }
4227
4228 return inode;
4229 }
4230
4231 static struct inode *new_simple_dir(struct super_block *s,
4232 struct btrfs_key *key,
4233 struct btrfs_root *root)
4234 {
4235 struct inode *inode = new_inode(s);
4236
4237 if (!inode)
4238 return ERR_PTR(-ENOMEM);
4239
4240 BTRFS_I(inode)->root = root;
4241 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
4242 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
4243
4244 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
4245 inode->i_op = &btrfs_dir_ro_inode_operations;
4246 inode->i_fop = &simple_dir_operations;
4247 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
4248 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
4249
4250 return inode;
4251 }
4252
4253 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
4254 {
4255 struct inode *inode;
4256 struct btrfs_root *root = BTRFS_I(dir)->root;
4257 struct btrfs_root *sub_root = root;
4258 struct btrfs_key location;
4259 int index;
4260 int ret = 0;
4261
4262 if (dentry->d_name.len > BTRFS_NAME_LEN)
4263 return ERR_PTR(-ENAMETOOLONG);
4264
4265 ret = btrfs_inode_by_name(dir, dentry, &location);
4266 if (ret < 0)
4267 return ERR_PTR(ret);
4268
4269 if (location.objectid == 0)
4270 return NULL;
4271
4272 if (location.type == BTRFS_INODE_ITEM_KEY) {
4273 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
4274 return inode;
4275 }
4276
4277 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
4278
4279 index = srcu_read_lock(&root->fs_info->subvol_srcu);
4280 ret = fixup_tree_root_location(root, dir, dentry,
4281 &location, &sub_root);
4282 if (ret < 0) {
4283 if (ret != -ENOENT)
4284 inode = ERR_PTR(ret);
4285 else
4286 inode = new_simple_dir(dir->i_sb, &location, sub_root);
4287 } else {
4288 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
4289 }
4290 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
4291
4292 if (!IS_ERR(inode) && root != sub_root) {
4293 down_read(&root->fs_info->cleanup_work_sem);
4294 if (!(inode->i_sb->s_flags & MS_RDONLY))
4295 ret = btrfs_orphan_cleanup(sub_root);
4296 up_read(&root->fs_info->cleanup_work_sem);
4297 if (ret)
4298 inode = ERR_PTR(ret);
4299 }
4300
4301 return inode;
4302 }
4303
4304 static int btrfs_dentry_delete(const struct dentry *dentry)
4305 {
4306 struct btrfs_root *root;
4307 struct inode *inode = dentry->d_inode;
4308
4309 if (!inode && !IS_ROOT(dentry))
4310 inode = dentry->d_parent->d_inode;
4311
4312 if (inode) {
4313 root = BTRFS_I(inode)->root;
4314 if (btrfs_root_refs(&root->root_item) == 0)
4315 return 1;
4316
4317 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
4318 return 1;
4319 }
4320 return 0;
4321 }
4322
4323 static void btrfs_dentry_release(struct dentry *dentry)
4324 {
4325 if (dentry->d_fsdata)
4326 kfree(dentry->d_fsdata);
4327 }
4328
4329 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
4330 unsigned int flags)
4331 {
4332 struct dentry *ret;
4333
4334 ret = d_splice_alias(btrfs_lookup_dentry(dir, dentry), dentry);
4335 return ret;
4336 }
4337
4338 unsigned char btrfs_filetype_table[] = {
4339 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
4340 };
4341
4342 static int btrfs_real_readdir(struct file *filp, void *dirent,
4343 filldir_t filldir)
4344 {
4345 struct inode *inode = filp->f_dentry->d_inode;
4346 struct btrfs_root *root = BTRFS_I(inode)->root;
4347 struct btrfs_item *item;
4348 struct btrfs_dir_item *di;
4349 struct btrfs_key key;
4350 struct btrfs_key found_key;
4351 struct btrfs_path *path;
4352 struct list_head ins_list;
4353 struct list_head del_list;
4354 int ret;
4355 struct extent_buffer *leaf;
4356 int slot;
4357 unsigned char d_type;
4358 int over = 0;
4359 u32 di_cur;
4360 u32 di_total;
4361 u32 di_len;
4362 int key_type = BTRFS_DIR_INDEX_KEY;
4363 char tmp_name[32];
4364 char *name_ptr;
4365 int name_len;
4366 int is_curr = 0; /* filp->f_pos points to the current index? */
4367
4368 /* FIXME, use a real flag for deciding about the key type */
4369 if (root->fs_info->tree_root == root)
4370 key_type = BTRFS_DIR_ITEM_KEY;
4371
4372 /* special case for "." */
4373 if (filp->f_pos == 0) {
4374 over = filldir(dirent, ".", 1,
4375 filp->f_pos, btrfs_ino(inode), DT_DIR);
4376 if (over)
4377 return 0;
4378 filp->f_pos = 1;
4379 }
4380 /* special case for .., just use the back ref */
4381 if (filp->f_pos == 1) {
4382 u64 pino = parent_ino(filp->f_path.dentry);
4383 over = filldir(dirent, "..", 2,
4384 filp->f_pos, pino, DT_DIR);
4385 if (over)
4386 return 0;
4387 filp->f_pos = 2;
4388 }
4389 path = btrfs_alloc_path();
4390 if (!path)
4391 return -ENOMEM;
4392
4393 path->reada = 1;
4394
4395 if (key_type == BTRFS_DIR_INDEX_KEY) {
4396 INIT_LIST_HEAD(&ins_list);
4397 INIT_LIST_HEAD(&del_list);
4398 btrfs_get_delayed_items(inode, &ins_list, &del_list);
4399 }
4400
4401 btrfs_set_key_type(&key, key_type);
4402 key.offset = filp->f_pos;
4403 key.objectid = btrfs_ino(inode);
4404
4405 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4406 if (ret < 0)
4407 goto err;
4408
4409 while (1) {
4410 leaf = path->nodes[0];
4411 slot = path->slots[0];
4412 if (slot >= btrfs_header_nritems(leaf)) {
4413 ret = btrfs_next_leaf(root, path);
4414 if (ret < 0)
4415 goto err;
4416 else if (ret > 0)
4417 break;
4418 continue;
4419 }
4420
4421 item = btrfs_item_nr(leaf, slot);
4422 btrfs_item_key_to_cpu(leaf, &found_key, slot);
4423
4424 if (found_key.objectid != key.objectid)
4425 break;
4426 if (btrfs_key_type(&found_key) != key_type)
4427 break;
4428 if (found_key.offset < filp->f_pos)
4429 goto next;
4430 if (key_type == BTRFS_DIR_INDEX_KEY &&
4431 btrfs_should_delete_dir_index(&del_list,
4432 found_key.offset))
4433 goto next;
4434
4435 filp->f_pos = found_key.offset;
4436 is_curr = 1;
4437
4438 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
4439 di_cur = 0;
4440 di_total = btrfs_item_size(leaf, item);
4441
4442 while (di_cur < di_total) {
4443 struct btrfs_key location;
4444
4445 if (verify_dir_item(root, leaf, di))
4446 break;
4447
4448 name_len = btrfs_dir_name_len(leaf, di);
4449 if (name_len <= sizeof(tmp_name)) {
4450 name_ptr = tmp_name;
4451 } else {
4452 name_ptr = kmalloc(name_len, GFP_NOFS);
4453 if (!name_ptr) {
4454 ret = -ENOMEM;
4455 goto err;
4456 }
4457 }
4458 read_extent_buffer(leaf, name_ptr,
4459 (unsigned long)(di + 1), name_len);
4460
4461 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
4462 btrfs_dir_item_key_to_cpu(leaf, di, &location);
4463
4464
4465 /* is this a reference to our own snapshot? If so
4466 * skip it.
4467 *
4468 * In contrast to old kernels, we insert the snapshot's
4469 * dir item and dir index after it has been created, so
4470 * we won't find a reference to our own snapshot. We
4471 * still keep the following code for backward
4472 * compatibility.
4473 */
4474 if (location.type == BTRFS_ROOT_ITEM_KEY &&
4475 location.objectid == root->root_key.objectid) {
4476 over = 0;
4477 goto skip;
4478 }
4479 over = filldir(dirent, name_ptr, name_len,
4480 found_key.offset, location.objectid,
4481 d_type);
4482
4483 skip:
4484 if (name_ptr != tmp_name)
4485 kfree(name_ptr);
4486
4487 if (over)
4488 goto nopos;
4489 di_len = btrfs_dir_name_len(leaf, di) +
4490 btrfs_dir_data_len(leaf, di) + sizeof(*di);
4491 di_cur += di_len;
4492 di = (struct btrfs_dir_item *)((char *)di + di_len);
4493 }
4494 next:
4495 path->slots[0]++;
4496 }
4497
4498 if (key_type == BTRFS_DIR_INDEX_KEY) {
4499 if (is_curr)
4500 filp->f_pos++;
4501 ret = btrfs_readdir_delayed_dir_index(filp, dirent, filldir,
4502 &ins_list);
4503 if (ret)
4504 goto nopos;
4505 }
4506
4507 /* Reached end of directory/root. Bump pos past the last item. */
4508 if (key_type == BTRFS_DIR_INDEX_KEY)
4509 /*
4510 * 32-bit glibc will use getdents64, but then strtol -
4511 * so the last number we can serve is this.
4512 */
4513 filp->f_pos = 0x7fffffff;
4514 else
4515 filp->f_pos++;
4516 nopos:
4517 ret = 0;
4518 err:
4519 if (key_type == BTRFS_DIR_INDEX_KEY)
4520 btrfs_put_delayed_items(&ins_list, &del_list);
4521 btrfs_free_path(path);
4522 return ret;
4523 }
4524
4525 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
4526 {
4527 struct btrfs_root *root = BTRFS_I(inode)->root;
4528 struct btrfs_trans_handle *trans;
4529 int ret = 0;
4530 bool nolock = false;
4531
4532 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
4533 return 0;
4534
4535 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
4536 nolock = true;
4537
4538 if (wbc->sync_mode == WB_SYNC_ALL) {
4539 if (nolock)
4540 trans = btrfs_join_transaction_nolock(root);
4541 else
4542 trans = btrfs_join_transaction(root);
4543 if (IS_ERR(trans))
4544 return PTR_ERR(trans);
4545 ret = btrfs_commit_transaction(trans, root);
4546 }
4547 return ret;
4548 }
4549
4550 /*
4551 * This is somewhat expensive, updating the tree every time the
4552 * inode changes. But, it is most likely to find the inode in cache.
4553 * FIXME, needs more benchmarking...there are no reasons other than performance
4554 * to keep or drop this code.
4555 */
4556 int btrfs_dirty_inode(struct inode *inode)
4557 {
4558 struct btrfs_root *root = BTRFS_I(inode)->root;
4559 struct btrfs_trans_handle *trans;
4560 int ret;
4561
4562 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
4563 return 0;
4564
4565 trans = btrfs_join_transaction(root);
4566 if (IS_ERR(trans))
4567 return PTR_ERR(trans);
4568
4569 ret = btrfs_update_inode(trans, root, inode);
4570 if (ret && ret == -ENOSPC) {
4571 /* whoops, lets try again with the full transaction */
4572 btrfs_end_transaction(trans, root);
4573 trans = btrfs_start_transaction(root, 1);
4574 if (IS_ERR(trans))
4575 return PTR_ERR(trans);
4576
4577 ret = btrfs_update_inode(trans, root, inode);
4578 }
4579 btrfs_end_transaction(trans, root);
4580 if (BTRFS_I(inode)->delayed_node)
4581 btrfs_balance_delayed_items(root);
4582
4583 return ret;
4584 }
4585
4586 /*
4587 * This is a copy of file_update_time. We need this so we can return error on
4588 * ENOSPC for updating the inode in the case of file write and mmap writes.
4589 */
4590 static int btrfs_update_time(struct inode *inode, struct timespec *now,
4591 int flags)
4592 {
4593 struct btrfs_root *root = BTRFS_I(inode)->root;
4594
4595 if (btrfs_root_readonly(root))
4596 return -EROFS;
4597
4598 if (flags & S_VERSION)
4599 inode_inc_iversion(inode);
4600 if (flags & S_CTIME)
4601 inode->i_ctime = *now;
4602 if (flags & S_MTIME)
4603 inode->i_mtime = *now;
4604 if (flags & S_ATIME)
4605 inode->i_atime = *now;
4606 return btrfs_dirty_inode(inode);
4607 }
4608
4609 /*
4610 * find the highest existing sequence number in a directory
4611 * and then set the in-memory index_cnt variable to reflect
4612 * free sequence numbers
4613 */
4614 static int btrfs_set_inode_index_count(struct inode *inode)
4615 {
4616 struct btrfs_root *root = BTRFS_I(inode)->root;
4617 struct btrfs_key key, found_key;
4618 struct btrfs_path *path;
4619 struct extent_buffer *leaf;
4620 int ret;
4621
4622 key.objectid = btrfs_ino(inode);
4623 btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
4624 key.offset = (u64)-1;
4625
4626 path = btrfs_alloc_path();
4627 if (!path)
4628 return -ENOMEM;
4629
4630 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4631 if (ret < 0)
4632 goto out;
4633 /* FIXME: we should be able to handle this */
4634 if (ret == 0)
4635 goto out;
4636 ret = 0;
4637
4638 /*
4639 * MAGIC NUMBER EXPLANATION:
4640 * since we search a directory based on f_pos we have to start at 2
4641 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
4642 * else has to start at 2
4643 */
4644 if (path->slots[0] == 0) {
4645 BTRFS_I(inode)->index_cnt = 2;
4646 goto out;
4647 }
4648
4649 path->slots[0]--;
4650
4651 leaf = path->nodes[0];
4652 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4653
4654 if (found_key.objectid != btrfs_ino(inode) ||
4655 btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) {
4656 BTRFS_I(inode)->index_cnt = 2;
4657 goto out;
4658 }
4659
4660 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
4661 out:
4662 btrfs_free_path(path);
4663 return ret;
4664 }
4665
4666 /*
4667 * helper to find a free sequence number in a given directory. This current
4668 * code is very simple, later versions will do smarter things in the btree
4669 */
4670 int btrfs_set_inode_index(struct inode *dir, u64 *index)
4671 {
4672 int ret = 0;
4673
4674 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
4675 ret = btrfs_inode_delayed_dir_index_count(dir);
4676 if (ret) {
4677 ret = btrfs_set_inode_index_count(dir);
4678 if (ret)
4679 return ret;
4680 }
4681 }
4682
4683 *index = BTRFS_I(dir)->index_cnt;
4684 BTRFS_I(dir)->index_cnt++;
4685
4686 return ret;
4687 }
4688
4689 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
4690 struct btrfs_root *root,
4691 struct inode *dir,
4692 const char *name, int name_len,
4693 u64 ref_objectid, u64 objectid,
4694 umode_t mode, u64 *index)
4695 {
4696 struct inode *inode;
4697 struct btrfs_inode_item *inode_item;
4698 struct btrfs_key *location;
4699 struct btrfs_path *path;
4700 struct btrfs_inode_ref *ref;
4701 struct btrfs_key key[2];
4702 u32 sizes[2];
4703 unsigned long ptr;
4704 int ret;
4705 int owner;
4706
4707 path = btrfs_alloc_path();
4708 if (!path)
4709 return ERR_PTR(-ENOMEM);
4710
4711 inode = new_inode(root->fs_info->sb);
4712 if (!inode) {
4713 btrfs_free_path(path);
4714 return ERR_PTR(-ENOMEM);
4715 }
4716
4717 /*
4718 * we have to initialize this early, so we can reclaim the inode
4719 * number if we fail afterwards in this function.
4720 */
4721 inode->i_ino = objectid;
4722
4723 if (dir) {
4724 trace_btrfs_inode_request(dir);
4725
4726 ret = btrfs_set_inode_index(dir, index);
4727 if (ret) {
4728 btrfs_free_path(path);
4729 iput(inode);
4730 return ERR_PTR(ret);
4731 }
4732 }
4733 /*
4734 * index_cnt is ignored for everything but a dir,
4735 * btrfs_get_inode_index_count has an explanation for the magic
4736 * number
4737 */
4738 BTRFS_I(inode)->index_cnt = 2;
4739 BTRFS_I(inode)->root = root;
4740 BTRFS_I(inode)->generation = trans->transid;
4741 inode->i_generation = BTRFS_I(inode)->generation;
4742
4743 /*
4744 * We could have gotten an inode number from somebody who was fsynced
4745 * and then removed in this same transaction, so let's just set full
4746 * sync since it will be a full sync anyway and this will blow away the
4747 * old info in the log.
4748 */
4749 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
4750
4751 if (S_ISDIR(mode))
4752 owner = 0;
4753 else
4754 owner = 1;
4755
4756 key[0].objectid = objectid;
4757 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
4758 key[0].offset = 0;
4759
4760 /*
4761 * Start new inodes with an inode_ref. This is slightly more
4762 * efficient for small numbers of hard links since they will
4763 * be packed into one item. Extended refs will kick in if we
4764 * add more hard links than can fit in the ref item.
4765 */
4766 key[1].objectid = objectid;
4767 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
4768 key[1].offset = ref_objectid;
4769
4770 sizes[0] = sizeof(struct btrfs_inode_item);
4771 sizes[1] = name_len + sizeof(*ref);
4772
4773 path->leave_spinning = 1;
4774 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
4775 if (ret != 0)
4776 goto fail;
4777
4778 inode_init_owner(inode, dir, mode);
4779 inode_set_bytes(inode, 0);
4780 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
4781 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
4782 struct btrfs_inode_item);
4783 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
4784 sizeof(*inode_item));
4785 fill_inode_item(trans, path->nodes[0], inode_item, inode);
4786
4787 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
4788 struct btrfs_inode_ref);
4789 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
4790 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
4791 ptr = (unsigned long)(ref + 1);
4792 write_extent_buffer(path->nodes[0], name, ptr, name_len);
4793
4794 btrfs_mark_buffer_dirty(path->nodes[0]);
4795 btrfs_free_path(path);
4796
4797 location = &BTRFS_I(inode)->location;
4798 location->objectid = objectid;
4799 location->offset = 0;
4800 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
4801
4802 btrfs_inherit_iflags(inode, dir);
4803
4804 if (S_ISREG(mode)) {
4805 if (btrfs_test_opt(root, NODATASUM))
4806 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
4807 if (btrfs_test_opt(root, NODATACOW))
4808 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
4809 }
4810
4811 insert_inode_hash(inode);
4812 inode_tree_add(inode);
4813
4814 trace_btrfs_inode_new(inode);
4815 btrfs_set_inode_last_trans(trans, inode);
4816
4817 btrfs_update_root_times(trans, root);
4818
4819 return inode;
4820 fail:
4821 if (dir)
4822 BTRFS_I(dir)->index_cnt--;
4823 btrfs_free_path(path);
4824 iput(inode);
4825 return ERR_PTR(ret);
4826 }
4827
4828 static inline u8 btrfs_inode_type(struct inode *inode)
4829 {
4830 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
4831 }
4832
4833 /*
4834 * utility function to add 'inode' into 'parent_inode' with
4835 * a give name and a given sequence number.
4836 * if 'add_backref' is true, also insert a backref from the
4837 * inode to the parent directory.
4838 */
4839 int btrfs_add_link(struct btrfs_trans_handle *trans,
4840 struct inode *parent_inode, struct inode *inode,
4841 const char *name, int name_len, int add_backref, u64 index)
4842 {
4843 int ret = 0;
4844 struct btrfs_key key;
4845 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
4846 u64 ino = btrfs_ino(inode);
4847 u64 parent_ino = btrfs_ino(parent_inode);
4848
4849 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
4850 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
4851 } else {
4852 key.objectid = ino;
4853 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
4854 key.offset = 0;
4855 }
4856
4857 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
4858 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
4859 key.objectid, root->root_key.objectid,
4860 parent_ino, index, name, name_len);
4861 } else if (add_backref) {
4862 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
4863 parent_ino, index);
4864 }
4865
4866 /* Nothing to clean up yet */
4867 if (ret)
4868 return ret;
4869
4870 ret = btrfs_insert_dir_item(trans, root, name, name_len,
4871 parent_inode, &key,
4872 btrfs_inode_type(inode), index);
4873 if (ret == -EEXIST || ret == -EOVERFLOW)
4874 goto fail_dir_item;
4875 else if (ret) {
4876 btrfs_abort_transaction(trans, root, ret);
4877 return ret;
4878 }
4879
4880 btrfs_i_size_write(parent_inode, parent_inode->i_size +
4881 name_len * 2);
4882 inode_inc_iversion(parent_inode);
4883 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
4884 ret = btrfs_update_inode(trans, root, parent_inode);
4885 if (ret)
4886 btrfs_abort_transaction(trans, root, ret);
4887 return ret;
4888
4889 fail_dir_item:
4890 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
4891 u64 local_index;
4892 int err;
4893 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
4894 key.objectid, root->root_key.objectid,
4895 parent_ino, &local_index, name, name_len);
4896
4897 } else if (add_backref) {
4898 u64 local_index;
4899 int err;
4900
4901 err = btrfs_del_inode_ref(trans, root, name, name_len,
4902 ino, parent_ino, &local_index);
4903 }
4904 return ret;
4905 }
4906
4907 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
4908 struct inode *dir, struct dentry *dentry,
4909 struct inode *inode, int backref, u64 index)
4910 {
4911 int err = btrfs_add_link(trans, dir, inode,
4912 dentry->d_name.name, dentry->d_name.len,
4913 backref, index);
4914 if (err > 0)
4915 err = -EEXIST;
4916 return err;
4917 }
4918
4919 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
4920 umode_t mode, dev_t rdev)
4921 {
4922 struct btrfs_trans_handle *trans;
4923 struct btrfs_root *root = BTRFS_I(dir)->root;
4924 struct inode *inode = NULL;
4925 int err;
4926 int drop_inode = 0;
4927 u64 objectid;
4928 u64 index = 0;
4929
4930 if (!new_valid_dev(rdev))
4931 return -EINVAL;
4932
4933 /*
4934 * 2 for inode item and ref
4935 * 2 for dir items
4936 * 1 for xattr if selinux is on
4937 */
4938 trans = btrfs_start_transaction(root, 5);
4939 if (IS_ERR(trans))
4940 return PTR_ERR(trans);
4941
4942 err = btrfs_find_free_ino(root, &objectid);
4943 if (err)
4944 goto out_unlock;
4945
4946 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
4947 dentry->d_name.len, btrfs_ino(dir), objectid,
4948 mode, &index);
4949 if (IS_ERR(inode)) {
4950 err = PTR_ERR(inode);
4951 goto out_unlock;
4952 }
4953
4954 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
4955 if (err) {
4956 drop_inode = 1;
4957 goto out_unlock;
4958 }
4959
4960 err = btrfs_update_inode(trans, root, inode);
4961 if (err) {
4962 drop_inode = 1;
4963 goto out_unlock;
4964 }
4965
4966 /*
4967 * If the active LSM wants to access the inode during
4968 * d_instantiate it needs these. Smack checks to see
4969 * if the filesystem supports xattrs by looking at the
4970 * ops vector.
4971 */
4972
4973 inode->i_op = &btrfs_special_inode_operations;
4974 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
4975 if (err)
4976 drop_inode = 1;
4977 else {
4978 init_special_inode(inode, inode->i_mode, rdev);
4979 btrfs_update_inode(trans, root, inode);
4980 d_instantiate(dentry, inode);
4981 }
4982 out_unlock:
4983 btrfs_end_transaction(trans, root);
4984 btrfs_btree_balance_dirty(root);
4985 if (drop_inode) {
4986 inode_dec_link_count(inode);
4987 iput(inode);
4988 }
4989 return err;
4990 }
4991
4992 static int btrfs_create(struct inode *dir, struct dentry *dentry,
4993 umode_t mode, bool excl)
4994 {
4995 struct btrfs_trans_handle *trans;
4996 struct btrfs_root *root = BTRFS_I(dir)->root;
4997 struct inode *inode = NULL;
4998 int drop_inode_on_err = 0;
4999 int err;
5000 u64 objectid;
5001 u64 index = 0;
5002
5003 /*
5004 * 2 for inode item and ref
5005 * 2 for dir items
5006 * 1 for xattr if selinux is on
5007 */
5008 trans = btrfs_start_transaction(root, 5);
5009 if (IS_ERR(trans))
5010 return PTR_ERR(trans);
5011
5012 err = btrfs_find_free_ino(root, &objectid);
5013 if (err)
5014 goto out_unlock;
5015
5016 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5017 dentry->d_name.len, btrfs_ino(dir), objectid,
5018 mode, &index);
5019 if (IS_ERR(inode)) {
5020 err = PTR_ERR(inode);
5021 goto out_unlock;
5022 }
5023 drop_inode_on_err = 1;
5024
5025 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5026 if (err)
5027 goto out_unlock;
5028
5029 err = btrfs_update_inode(trans, root, inode);
5030 if (err)
5031 goto out_unlock;
5032
5033 /*
5034 * If the active LSM wants to access the inode during
5035 * d_instantiate it needs these. Smack checks to see
5036 * if the filesystem supports xattrs by looking at the
5037 * ops vector.
5038 */
5039 inode->i_fop = &btrfs_file_operations;
5040 inode->i_op = &btrfs_file_inode_operations;
5041
5042 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5043 if (err)
5044 goto out_unlock;
5045
5046 inode->i_mapping->a_ops = &btrfs_aops;
5047 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
5048 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
5049 d_instantiate(dentry, inode);
5050
5051 out_unlock:
5052 btrfs_end_transaction(trans, root);
5053 if (err && drop_inode_on_err) {
5054 inode_dec_link_count(inode);
5055 iput(inode);
5056 }
5057 btrfs_btree_balance_dirty(root);
5058 return err;
5059 }
5060
5061 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
5062 struct dentry *dentry)
5063 {
5064 struct btrfs_trans_handle *trans;
5065 struct btrfs_root *root = BTRFS_I(dir)->root;
5066 struct inode *inode = old_dentry->d_inode;
5067 u64 index;
5068 int err;
5069 int drop_inode = 0;
5070
5071 /* do not allow sys_link's with other subvols of the same device */
5072 if (root->objectid != BTRFS_I(inode)->root->objectid)
5073 return -EXDEV;
5074
5075 if (inode->i_nlink >= BTRFS_LINK_MAX)
5076 return -EMLINK;
5077
5078 err = btrfs_set_inode_index(dir, &index);
5079 if (err)
5080 goto fail;
5081
5082 /*
5083 * 2 items for inode and inode ref
5084 * 2 items for dir items
5085 * 1 item for parent inode
5086 */
5087 trans = btrfs_start_transaction(root, 5);
5088 if (IS_ERR(trans)) {
5089 err = PTR_ERR(trans);
5090 goto fail;
5091 }
5092
5093 btrfs_inc_nlink(inode);
5094 inode_inc_iversion(inode);
5095 inode->i_ctime = CURRENT_TIME;
5096 ihold(inode);
5097 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
5098
5099 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
5100
5101 if (err) {
5102 drop_inode = 1;
5103 } else {
5104 struct dentry *parent = dentry->d_parent;
5105 err = btrfs_update_inode(trans, root, inode);
5106 if (err)
5107 goto fail;
5108 d_instantiate(dentry, inode);
5109 btrfs_log_new_name(trans, inode, NULL, parent);
5110 }
5111
5112 btrfs_end_transaction(trans, root);
5113 fail:
5114 if (drop_inode) {
5115 inode_dec_link_count(inode);
5116 iput(inode);
5117 }
5118 btrfs_btree_balance_dirty(root);
5119 return err;
5120 }
5121
5122 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
5123 {
5124 struct inode *inode = NULL;
5125 struct btrfs_trans_handle *trans;
5126 struct btrfs_root *root = BTRFS_I(dir)->root;
5127 int err = 0;
5128 int drop_on_err = 0;
5129 u64 objectid = 0;
5130 u64 index = 0;
5131
5132 /*
5133 * 2 items for inode and ref
5134 * 2 items for dir items
5135 * 1 for xattr if selinux is on
5136 */
5137 trans = btrfs_start_transaction(root, 5);
5138 if (IS_ERR(trans))
5139 return PTR_ERR(trans);
5140
5141 err = btrfs_find_free_ino(root, &objectid);
5142 if (err)
5143 goto out_fail;
5144
5145 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5146 dentry->d_name.len, btrfs_ino(dir), objectid,
5147 S_IFDIR | mode, &index);
5148 if (IS_ERR(inode)) {
5149 err = PTR_ERR(inode);
5150 goto out_fail;
5151 }
5152
5153 drop_on_err = 1;
5154
5155 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5156 if (err)
5157 goto out_fail;
5158
5159 inode->i_op = &btrfs_dir_inode_operations;
5160 inode->i_fop = &btrfs_dir_file_operations;
5161
5162 btrfs_i_size_write(inode, 0);
5163 err = btrfs_update_inode(trans, root, inode);
5164 if (err)
5165 goto out_fail;
5166
5167 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
5168 dentry->d_name.len, 0, index);
5169 if (err)
5170 goto out_fail;
5171
5172 d_instantiate(dentry, inode);
5173 drop_on_err = 0;
5174
5175 out_fail:
5176 btrfs_end_transaction(trans, root);
5177 if (drop_on_err)
5178 iput(inode);
5179 btrfs_btree_balance_dirty(root);
5180 return err;
5181 }
5182
5183 /* helper for btfs_get_extent. Given an existing extent in the tree,
5184 * and an extent that you want to insert, deal with overlap and insert
5185 * the new extent into the tree.
5186 */
5187 static int merge_extent_mapping(struct extent_map_tree *em_tree,
5188 struct extent_map *existing,
5189 struct extent_map *em,
5190 u64 map_start, u64 map_len)
5191 {
5192 u64 start_diff;
5193
5194 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
5195 start_diff = map_start - em->start;
5196 em->start = map_start;
5197 em->len = map_len;
5198 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
5199 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
5200 em->block_start += start_diff;
5201 em->block_len -= start_diff;
5202 }
5203 return add_extent_mapping(em_tree, em);
5204 }
5205
5206 static noinline int uncompress_inline(struct btrfs_path *path,
5207 struct inode *inode, struct page *page,
5208 size_t pg_offset, u64 extent_offset,
5209 struct btrfs_file_extent_item *item)
5210 {
5211 int ret;
5212 struct extent_buffer *leaf = path->nodes[0];
5213 char *tmp;
5214 size_t max_size;
5215 unsigned long inline_size;
5216 unsigned long ptr;
5217 int compress_type;
5218
5219 WARN_ON(pg_offset != 0);
5220 compress_type = btrfs_file_extent_compression(leaf, item);
5221 max_size = btrfs_file_extent_ram_bytes(leaf, item);
5222 inline_size = btrfs_file_extent_inline_item_len(leaf,
5223 btrfs_item_nr(leaf, path->slots[0]));
5224 tmp = kmalloc(inline_size, GFP_NOFS);
5225 if (!tmp)
5226 return -ENOMEM;
5227 ptr = btrfs_file_extent_inline_start(item);
5228
5229 read_extent_buffer(leaf, tmp, ptr, inline_size);
5230
5231 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
5232 ret = btrfs_decompress(compress_type, tmp, page,
5233 extent_offset, inline_size, max_size);
5234 if (ret) {
5235 char *kaddr = kmap_atomic(page);
5236 unsigned long copy_size = min_t(u64,
5237 PAGE_CACHE_SIZE - pg_offset,
5238 max_size - extent_offset);
5239 memset(kaddr + pg_offset, 0, copy_size);
5240 kunmap_atomic(kaddr);
5241 }
5242 kfree(tmp);
5243 return 0;
5244 }
5245
5246 /*
5247 * a bit scary, this does extent mapping from logical file offset to the disk.
5248 * the ugly parts come from merging extents from the disk with the in-ram
5249 * representation. This gets more complex because of the data=ordered code,
5250 * where the in-ram extents might be locked pending data=ordered completion.
5251 *
5252 * This also copies inline extents directly into the page.
5253 */
5254
5255 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
5256 size_t pg_offset, u64 start, u64 len,
5257 int create)
5258 {
5259 int ret;
5260 int err = 0;
5261 u64 bytenr;
5262 u64 extent_start = 0;
5263 u64 extent_end = 0;
5264 u64 objectid = btrfs_ino(inode);
5265 u32 found_type;
5266 struct btrfs_path *path = NULL;
5267 struct btrfs_root *root = BTRFS_I(inode)->root;
5268 struct btrfs_file_extent_item *item;
5269 struct extent_buffer *leaf;
5270 struct btrfs_key found_key;
5271 struct extent_map *em = NULL;
5272 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
5273 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5274 struct btrfs_trans_handle *trans = NULL;
5275 int compress_type;
5276
5277 again:
5278 read_lock(&em_tree->lock);
5279 em = lookup_extent_mapping(em_tree, start, len);
5280 if (em)
5281 em->bdev = root->fs_info->fs_devices->latest_bdev;
5282 read_unlock(&em_tree->lock);
5283
5284 if (em) {
5285 if (em->start > start || em->start + em->len <= start)
5286 free_extent_map(em);
5287 else if (em->block_start == EXTENT_MAP_INLINE && page)
5288 free_extent_map(em);
5289 else
5290 goto out;
5291 }
5292 em = alloc_extent_map();
5293 if (!em) {
5294 err = -ENOMEM;
5295 goto out;
5296 }
5297 em->bdev = root->fs_info->fs_devices->latest_bdev;
5298 em->start = EXTENT_MAP_HOLE;
5299 em->orig_start = EXTENT_MAP_HOLE;
5300 em->len = (u64)-1;
5301 em->block_len = (u64)-1;
5302
5303 if (!path) {
5304 path = btrfs_alloc_path();
5305 if (!path) {
5306 err = -ENOMEM;
5307 goto out;
5308 }
5309 /*
5310 * Chances are we'll be called again, so go ahead and do
5311 * readahead
5312 */
5313 path->reada = 1;
5314 }
5315
5316 ret = btrfs_lookup_file_extent(trans, root, path,
5317 objectid, start, trans != NULL);
5318 if (ret < 0) {
5319 err = ret;
5320 goto out;
5321 }
5322
5323 if (ret != 0) {
5324 if (path->slots[0] == 0)
5325 goto not_found;
5326 path->slots[0]--;
5327 }
5328
5329 leaf = path->nodes[0];
5330 item = btrfs_item_ptr(leaf, path->slots[0],
5331 struct btrfs_file_extent_item);
5332 /* are we inside the extent that was found? */
5333 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5334 found_type = btrfs_key_type(&found_key);
5335 if (found_key.objectid != objectid ||
5336 found_type != BTRFS_EXTENT_DATA_KEY) {
5337 goto not_found;
5338 }
5339
5340 found_type = btrfs_file_extent_type(leaf, item);
5341 extent_start = found_key.offset;
5342 compress_type = btrfs_file_extent_compression(leaf, item);
5343 if (found_type == BTRFS_FILE_EXTENT_REG ||
5344 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
5345 extent_end = extent_start +
5346 btrfs_file_extent_num_bytes(leaf, item);
5347 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
5348 size_t size;
5349 size = btrfs_file_extent_inline_len(leaf, item);
5350 extent_end = (extent_start + size + root->sectorsize - 1) &
5351 ~((u64)root->sectorsize - 1);
5352 }
5353
5354 if (start >= extent_end) {
5355 path->slots[0]++;
5356 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
5357 ret = btrfs_next_leaf(root, path);
5358 if (ret < 0) {
5359 err = ret;
5360 goto out;
5361 }
5362 if (ret > 0)
5363 goto not_found;
5364 leaf = path->nodes[0];
5365 }
5366 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5367 if (found_key.objectid != objectid ||
5368 found_key.type != BTRFS_EXTENT_DATA_KEY)
5369 goto not_found;
5370 if (start + len <= found_key.offset)
5371 goto not_found;
5372 em->start = start;
5373 em->orig_start = start;
5374 em->len = found_key.offset - start;
5375 goto not_found_em;
5376 }
5377
5378 if (found_type == BTRFS_FILE_EXTENT_REG ||
5379 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
5380 em->start = extent_start;
5381 em->len = extent_end - extent_start;
5382 em->orig_start = extent_start -
5383 btrfs_file_extent_offset(leaf, item);
5384 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf,
5385 item);
5386 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
5387 if (bytenr == 0) {
5388 em->block_start = EXTENT_MAP_HOLE;
5389 goto insert;
5390 }
5391 if (compress_type != BTRFS_COMPRESS_NONE) {
5392 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
5393 em->compress_type = compress_type;
5394 em->block_start = bytenr;
5395 em->block_len = em->orig_block_len;
5396 } else {
5397 bytenr += btrfs_file_extent_offset(leaf, item);
5398 em->block_start = bytenr;
5399 em->block_len = em->len;
5400 if (found_type == BTRFS_FILE_EXTENT_PREALLOC)
5401 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
5402 }
5403 goto insert;
5404 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
5405 unsigned long ptr;
5406 char *map;
5407 size_t size;
5408 size_t extent_offset;
5409 size_t copy_size;
5410
5411 em->block_start = EXTENT_MAP_INLINE;
5412 if (!page || create) {
5413 em->start = extent_start;
5414 em->len = extent_end - extent_start;
5415 goto out;
5416 }
5417
5418 size = btrfs_file_extent_inline_len(leaf, item);
5419 extent_offset = page_offset(page) + pg_offset - extent_start;
5420 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
5421 size - extent_offset);
5422 em->start = extent_start + extent_offset;
5423 em->len = (copy_size + root->sectorsize - 1) &
5424 ~((u64)root->sectorsize - 1);
5425 em->orig_block_len = em->len;
5426 em->orig_start = em->start;
5427 if (compress_type) {
5428 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
5429 em->compress_type = compress_type;
5430 }
5431 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
5432 if (create == 0 && !PageUptodate(page)) {
5433 if (btrfs_file_extent_compression(leaf, item) !=
5434 BTRFS_COMPRESS_NONE) {
5435 ret = uncompress_inline(path, inode, page,
5436 pg_offset,
5437 extent_offset, item);
5438 BUG_ON(ret); /* -ENOMEM */
5439 } else {
5440 map = kmap(page);
5441 read_extent_buffer(leaf, map + pg_offset, ptr,
5442 copy_size);
5443 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
5444 memset(map + pg_offset + copy_size, 0,
5445 PAGE_CACHE_SIZE - pg_offset -
5446 copy_size);
5447 }
5448 kunmap(page);
5449 }
5450 flush_dcache_page(page);
5451 } else if (create && PageUptodate(page)) {
5452 BUG();
5453 if (!trans) {
5454 kunmap(page);
5455 free_extent_map(em);
5456 em = NULL;
5457
5458 btrfs_release_path(path);
5459 trans = btrfs_join_transaction(root);
5460
5461 if (IS_ERR(trans))
5462 return ERR_CAST(trans);
5463 goto again;
5464 }
5465 map = kmap(page);
5466 write_extent_buffer(leaf, map + pg_offset, ptr,
5467 copy_size);
5468 kunmap(page);
5469 btrfs_mark_buffer_dirty(leaf);
5470 }
5471 set_extent_uptodate(io_tree, em->start,
5472 extent_map_end(em) - 1, NULL, GFP_NOFS);
5473 goto insert;
5474 } else {
5475 WARN(1, KERN_ERR "btrfs unknown found_type %d\n", found_type);
5476 }
5477 not_found:
5478 em->start = start;
5479 em->orig_start = start;
5480 em->len = len;
5481 not_found_em:
5482 em->block_start = EXTENT_MAP_HOLE;
5483 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
5484 insert:
5485 btrfs_release_path(path);
5486 if (em->start > start || extent_map_end(em) <= start) {
5487 printk(KERN_ERR "Btrfs: bad extent! em: [%llu %llu] passed "
5488 "[%llu %llu]\n", (unsigned long long)em->start,
5489 (unsigned long long)em->len,
5490 (unsigned long long)start,
5491 (unsigned long long)len);
5492 err = -EIO;
5493 goto out;
5494 }
5495
5496 err = 0;
5497 write_lock(&em_tree->lock);
5498 ret = add_extent_mapping(em_tree, em);
5499 /* it is possible that someone inserted the extent into the tree
5500 * while we had the lock dropped. It is also possible that
5501 * an overlapping map exists in the tree
5502 */
5503 if (ret == -EEXIST) {
5504 struct extent_map *existing;
5505
5506 ret = 0;
5507
5508 existing = lookup_extent_mapping(em_tree, start, len);
5509 if (existing && (existing->start > start ||
5510 existing->start + existing->len <= start)) {
5511 free_extent_map(existing);
5512 existing = NULL;
5513 }
5514 if (!existing) {
5515 existing = lookup_extent_mapping(em_tree, em->start,
5516 em->len);
5517 if (existing) {
5518 err = merge_extent_mapping(em_tree, existing,
5519 em, start,
5520 root->sectorsize);
5521 free_extent_map(existing);
5522 if (err) {
5523 free_extent_map(em);
5524 em = NULL;
5525 }
5526 } else {
5527 err = -EIO;
5528 free_extent_map(em);
5529 em = NULL;
5530 }
5531 } else {
5532 free_extent_map(em);
5533 em = existing;
5534 err = 0;
5535 }
5536 }
5537 write_unlock(&em_tree->lock);
5538 out:
5539
5540 if (em)
5541 trace_btrfs_get_extent(root, em);
5542
5543 if (path)
5544 btrfs_free_path(path);
5545 if (trans) {
5546 ret = btrfs_end_transaction(trans, root);
5547 if (!err)
5548 err = ret;
5549 }
5550 if (err) {
5551 free_extent_map(em);
5552 return ERR_PTR(err);
5553 }
5554 BUG_ON(!em); /* Error is always set */
5555 return em;
5556 }
5557
5558 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
5559 size_t pg_offset, u64 start, u64 len,
5560 int create)
5561 {
5562 struct extent_map *em;
5563 struct extent_map *hole_em = NULL;
5564 u64 range_start = start;
5565 u64 end;
5566 u64 found;
5567 u64 found_end;
5568 int err = 0;
5569
5570 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
5571 if (IS_ERR(em))
5572 return em;
5573 if (em) {
5574 /*
5575 * if our em maps to a hole, there might
5576 * actually be delalloc bytes behind it
5577 */
5578 if (em->block_start != EXTENT_MAP_HOLE)
5579 return em;
5580 else
5581 hole_em = em;
5582 }
5583
5584 /* check to see if we've wrapped (len == -1 or similar) */
5585 end = start + len;
5586 if (end < start)
5587 end = (u64)-1;
5588 else
5589 end -= 1;
5590
5591 em = NULL;
5592
5593 /* ok, we didn't find anything, lets look for delalloc */
5594 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
5595 end, len, EXTENT_DELALLOC, 1);
5596 found_end = range_start + found;
5597 if (found_end < range_start)
5598 found_end = (u64)-1;
5599
5600 /*
5601 * we didn't find anything useful, return
5602 * the original results from get_extent()
5603 */
5604 if (range_start > end || found_end <= start) {
5605 em = hole_em;
5606 hole_em = NULL;
5607 goto out;
5608 }
5609
5610 /* adjust the range_start to make sure it doesn't
5611 * go backwards from the start they passed in
5612 */
5613 range_start = max(start,range_start);
5614 found = found_end - range_start;
5615
5616 if (found > 0) {
5617 u64 hole_start = start;
5618 u64 hole_len = len;
5619
5620 em = alloc_extent_map();
5621 if (!em) {
5622 err = -ENOMEM;
5623 goto out;
5624 }
5625 /*
5626 * when btrfs_get_extent can't find anything it
5627 * returns one huge hole
5628 *
5629 * make sure what it found really fits our range, and
5630 * adjust to make sure it is based on the start from
5631 * the caller
5632 */
5633 if (hole_em) {
5634 u64 calc_end = extent_map_end(hole_em);
5635
5636 if (calc_end <= start || (hole_em->start > end)) {
5637 free_extent_map(hole_em);
5638 hole_em = NULL;
5639 } else {
5640 hole_start = max(hole_em->start, start);
5641 hole_len = calc_end - hole_start;
5642 }
5643 }
5644 em->bdev = NULL;
5645 if (hole_em && range_start > hole_start) {
5646 /* our hole starts before our delalloc, so we
5647 * have to return just the parts of the hole
5648 * that go until the delalloc starts
5649 */
5650 em->len = min(hole_len,
5651 range_start - hole_start);
5652 em->start = hole_start;
5653 em->orig_start = hole_start;
5654 /*
5655 * don't adjust block start at all,
5656 * it is fixed at EXTENT_MAP_HOLE
5657 */
5658 em->block_start = hole_em->block_start;
5659 em->block_len = hole_len;
5660 } else {
5661 em->start = range_start;
5662 em->len = found;
5663 em->orig_start = range_start;
5664 em->block_start = EXTENT_MAP_DELALLOC;
5665 em->block_len = found;
5666 }
5667 } else if (hole_em) {
5668 return hole_em;
5669 }
5670 out:
5671
5672 free_extent_map(hole_em);
5673 if (err) {
5674 free_extent_map(em);
5675 return ERR_PTR(err);
5676 }
5677 return em;
5678 }
5679
5680 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
5681 u64 start, u64 len)
5682 {
5683 struct btrfs_root *root = BTRFS_I(inode)->root;
5684 struct btrfs_trans_handle *trans;
5685 struct extent_map *em;
5686 struct btrfs_key ins;
5687 u64 alloc_hint;
5688 int ret;
5689
5690 trans = btrfs_join_transaction(root);
5691 if (IS_ERR(trans))
5692 return ERR_CAST(trans);
5693
5694 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
5695
5696 alloc_hint = get_extent_allocation_hint(inode, start, len);
5697 ret = btrfs_reserve_extent(trans, root, len, root->sectorsize, 0,
5698 alloc_hint, &ins, 1);
5699 if (ret) {
5700 em = ERR_PTR(ret);
5701 goto out;
5702 }
5703
5704 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
5705 ins.offset, ins.offset, 0);
5706 if (IS_ERR(em))
5707 goto out;
5708
5709 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
5710 ins.offset, ins.offset, 0);
5711 if (ret) {
5712 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
5713 em = ERR_PTR(ret);
5714 }
5715 out:
5716 btrfs_end_transaction(trans, root);
5717 return em;
5718 }
5719
5720 /*
5721 * returns 1 when the nocow is safe, < 1 on error, 0 if the
5722 * block must be cow'd
5723 */
5724 static noinline int can_nocow_odirect(struct btrfs_trans_handle *trans,
5725 struct inode *inode, u64 offset, u64 len)
5726 {
5727 struct btrfs_path *path;
5728 int ret;
5729 struct extent_buffer *leaf;
5730 struct btrfs_root *root = BTRFS_I(inode)->root;
5731 struct btrfs_file_extent_item *fi;
5732 struct btrfs_key key;
5733 u64 disk_bytenr;
5734 u64 backref_offset;
5735 u64 extent_end;
5736 u64 num_bytes;
5737 int slot;
5738 int found_type;
5739
5740 path = btrfs_alloc_path();
5741 if (!path)
5742 return -ENOMEM;
5743
5744 ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(inode),
5745 offset, 0);
5746 if (ret < 0)
5747 goto out;
5748
5749 slot = path->slots[0];
5750 if (ret == 1) {
5751 if (slot == 0) {
5752 /* can't find the item, must cow */
5753 ret = 0;
5754 goto out;
5755 }
5756 slot--;
5757 }
5758 ret = 0;
5759 leaf = path->nodes[0];
5760 btrfs_item_key_to_cpu(leaf, &key, slot);
5761 if (key.objectid != btrfs_ino(inode) ||
5762 key.type != BTRFS_EXTENT_DATA_KEY) {
5763 /* not our file or wrong item type, must cow */
5764 goto out;
5765 }
5766
5767 if (key.offset > offset) {
5768 /* Wrong offset, must cow */
5769 goto out;
5770 }
5771
5772 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
5773 found_type = btrfs_file_extent_type(leaf, fi);
5774 if (found_type != BTRFS_FILE_EXTENT_REG &&
5775 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
5776 /* not a regular extent, must cow */
5777 goto out;
5778 }
5779 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
5780 backref_offset = btrfs_file_extent_offset(leaf, fi);
5781
5782 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
5783 if (extent_end < offset + len) {
5784 /* extent doesn't include our full range, must cow */
5785 goto out;
5786 }
5787
5788 if (btrfs_extent_readonly(root, disk_bytenr))
5789 goto out;
5790
5791 /*
5792 * look for other files referencing this extent, if we
5793 * find any we must cow
5794 */
5795 if (btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
5796 key.offset - backref_offset, disk_bytenr))
5797 goto out;
5798
5799 /*
5800 * adjust disk_bytenr and num_bytes to cover just the bytes
5801 * in this extent we are about to write. If there
5802 * are any csums in that range we have to cow in order
5803 * to keep the csums correct
5804 */
5805 disk_bytenr += backref_offset;
5806 disk_bytenr += offset - key.offset;
5807 num_bytes = min(offset + len, extent_end) - offset;
5808 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
5809 goto out;
5810 /*
5811 * all of the above have passed, it is safe to overwrite this extent
5812 * without cow
5813 */
5814 ret = 1;
5815 out:
5816 btrfs_free_path(path);
5817 return ret;
5818 }
5819
5820 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
5821 struct extent_state **cached_state, int writing)
5822 {
5823 struct btrfs_ordered_extent *ordered;
5824 int ret = 0;
5825
5826 while (1) {
5827 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
5828 0, cached_state);
5829 /*
5830 * We're concerned with the entire range that we're going to be
5831 * doing DIO to, so we need to make sure theres no ordered
5832 * extents in this range.
5833 */
5834 ordered = btrfs_lookup_ordered_range(inode, lockstart,
5835 lockend - lockstart + 1);
5836
5837 /*
5838 * We need to make sure there are no buffered pages in this
5839 * range either, we could have raced between the invalidate in
5840 * generic_file_direct_write and locking the extent. The
5841 * invalidate needs to happen so that reads after a write do not
5842 * get stale data.
5843 */
5844 if (!ordered && (!writing ||
5845 !test_range_bit(&BTRFS_I(inode)->io_tree,
5846 lockstart, lockend, EXTENT_UPTODATE, 0,
5847 *cached_state)))
5848 break;
5849
5850 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
5851 cached_state, GFP_NOFS);
5852
5853 if (ordered) {
5854 btrfs_start_ordered_extent(inode, ordered, 1);
5855 btrfs_put_ordered_extent(ordered);
5856 } else {
5857 /* Screw you mmap */
5858 ret = filemap_write_and_wait_range(inode->i_mapping,
5859 lockstart,
5860 lockend);
5861 if (ret)
5862 break;
5863
5864 /*
5865 * If we found a page that couldn't be invalidated just
5866 * fall back to buffered.
5867 */
5868 ret = invalidate_inode_pages2_range(inode->i_mapping,
5869 lockstart >> PAGE_CACHE_SHIFT,
5870 lockend >> PAGE_CACHE_SHIFT);
5871 if (ret)
5872 break;
5873 }
5874
5875 cond_resched();
5876 }
5877
5878 return ret;
5879 }
5880
5881 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
5882 u64 len, u64 orig_start,
5883 u64 block_start, u64 block_len,
5884 u64 orig_block_len, int type)
5885 {
5886 struct extent_map_tree *em_tree;
5887 struct extent_map *em;
5888 struct btrfs_root *root = BTRFS_I(inode)->root;
5889 int ret;
5890
5891 em_tree = &BTRFS_I(inode)->extent_tree;
5892 em = alloc_extent_map();
5893 if (!em)
5894 return ERR_PTR(-ENOMEM);
5895
5896 em->start = start;
5897 em->orig_start = orig_start;
5898 em->len = len;
5899 em->block_len = block_len;
5900 em->block_start = block_start;
5901 em->bdev = root->fs_info->fs_devices->latest_bdev;
5902 em->orig_block_len = orig_block_len;
5903 em->generation = -1;
5904 set_bit(EXTENT_FLAG_PINNED, &em->flags);
5905 if (type == BTRFS_ORDERED_PREALLOC)
5906 set_bit(EXTENT_FLAG_FILLING, &em->flags);
5907
5908 do {
5909 btrfs_drop_extent_cache(inode, em->start,
5910 em->start + em->len - 1, 0);
5911 write_lock(&em_tree->lock);
5912 ret = add_extent_mapping(em_tree, em);
5913 if (!ret)
5914 list_move(&em->list,
5915 &em_tree->modified_extents);
5916 write_unlock(&em_tree->lock);
5917 } while (ret == -EEXIST);
5918
5919 if (ret) {
5920 free_extent_map(em);
5921 return ERR_PTR(ret);
5922 }
5923
5924 return em;
5925 }
5926
5927
5928 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
5929 struct buffer_head *bh_result, int create)
5930 {
5931 struct extent_map *em;
5932 struct btrfs_root *root = BTRFS_I(inode)->root;
5933 struct extent_state *cached_state = NULL;
5934 u64 start = iblock << inode->i_blkbits;
5935 u64 lockstart, lockend;
5936 u64 len = bh_result->b_size;
5937 struct btrfs_trans_handle *trans;
5938 int unlock_bits = EXTENT_LOCKED;
5939 int ret;
5940
5941 if (create) {
5942 ret = btrfs_delalloc_reserve_space(inode, len);
5943 if (ret)
5944 return ret;
5945 unlock_bits |= EXTENT_DELALLOC | EXTENT_DIRTY;
5946 } else {
5947 len = min_t(u64, len, root->sectorsize);
5948 }
5949
5950 lockstart = start;
5951 lockend = start + len - 1;
5952
5953 /*
5954 * If this errors out it's because we couldn't invalidate pagecache for
5955 * this range and we need to fallback to buffered.
5956 */
5957 if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create))
5958 return -ENOTBLK;
5959
5960 if (create) {
5961 ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
5962 lockend, EXTENT_DELALLOC, NULL,
5963 &cached_state, GFP_NOFS);
5964 if (ret)
5965 goto unlock_err;
5966 }
5967
5968 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
5969 if (IS_ERR(em)) {
5970 ret = PTR_ERR(em);
5971 goto unlock_err;
5972 }
5973
5974 /*
5975 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
5976 * io. INLINE is special, and we could probably kludge it in here, but
5977 * it's still buffered so for safety lets just fall back to the generic
5978 * buffered path.
5979 *
5980 * For COMPRESSED we _have_ to read the entire extent in so we can
5981 * decompress it, so there will be buffering required no matter what we
5982 * do, so go ahead and fallback to buffered.
5983 *
5984 * We return -ENOTBLK because thats what makes DIO go ahead and go back
5985 * to buffered IO. Don't blame me, this is the price we pay for using
5986 * the generic code.
5987 */
5988 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
5989 em->block_start == EXTENT_MAP_INLINE) {
5990 free_extent_map(em);
5991 ret = -ENOTBLK;
5992 goto unlock_err;
5993 }
5994
5995 /* Just a good old fashioned hole, return */
5996 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
5997 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
5998 free_extent_map(em);
5999 ret = 0;
6000 goto unlock_err;
6001 }
6002
6003 /*
6004 * We don't allocate a new extent in the following cases
6005 *
6006 * 1) The inode is marked as NODATACOW. In this case we'll just use the
6007 * existing extent.
6008 * 2) The extent is marked as PREALLOC. We're good to go here and can
6009 * just use the extent.
6010 *
6011 */
6012 if (!create) {
6013 len = min(len, em->len - (start - em->start));
6014 lockstart = start + len;
6015 goto unlock;
6016 }
6017
6018 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
6019 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
6020 em->block_start != EXTENT_MAP_HOLE)) {
6021 int type;
6022 int ret;
6023 u64 block_start;
6024
6025 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6026 type = BTRFS_ORDERED_PREALLOC;
6027 else
6028 type = BTRFS_ORDERED_NOCOW;
6029 len = min(len, em->len - (start - em->start));
6030 block_start = em->block_start + (start - em->start);
6031
6032 /*
6033 * we're not going to log anything, but we do need
6034 * to make sure the current transaction stays open
6035 * while we look for nocow cross refs
6036 */
6037 trans = btrfs_join_transaction(root);
6038 if (IS_ERR(trans))
6039 goto must_cow;
6040
6041 if (can_nocow_odirect(trans, inode, start, len) == 1) {
6042 u64 orig_start = em->orig_start;
6043 u64 orig_block_len = em->orig_block_len;
6044
6045 if (type == BTRFS_ORDERED_PREALLOC) {
6046 free_extent_map(em);
6047 em = create_pinned_em(inode, start, len,
6048 orig_start,
6049 block_start, len,
6050 orig_block_len, type);
6051 if (IS_ERR(em)) {
6052 btrfs_end_transaction(trans, root);
6053 goto unlock_err;
6054 }
6055 }
6056
6057 ret = btrfs_add_ordered_extent_dio(inode, start,
6058 block_start, len, len, type);
6059 btrfs_end_transaction(trans, root);
6060 if (ret) {
6061 free_extent_map(em);
6062 goto unlock_err;
6063 }
6064 goto unlock;
6065 }
6066 btrfs_end_transaction(trans, root);
6067 }
6068 must_cow:
6069 /*
6070 * this will cow the extent, reset the len in case we changed
6071 * it above
6072 */
6073 len = bh_result->b_size;
6074 free_extent_map(em);
6075 em = btrfs_new_extent_direct(inode, start, len);
6076 if (IS_ERR(em)) {
6077 ret = PTR_ERR(em);
6078 goto unlock_err;
6079 }
6080 len = min(len, em->len - (start - em->start));
6081 unlock:
6082 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
6083 inode->i_blkbits;
6084 bh_result->b_size = len;
6085 bh_result->b_bdev = em->bdev;
6086 set_buffer_mapped(bh_result);
6087 if (create) {
6088 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6089 set_buffer_new(bh_result);
6090
6091 /*
6092 * Need to update the i_size under the extent lock so buffered
6093 * readers will get the updated i_size when we unlock.
6094 */
6095 if (start + len > i_size_read(inode))
6096 i_size_write(inode, start + len);
6097 }
6098
6099 /*
6100 * In the case of write we need to clear and unlock the entire range,
6101 * in the case of read we need to unlock only the end area that we
6102 * aren't using if there is any left over space.
6103 */
6104 if (lockstart < lockend) {
6105 if (create && len < lockend - lockstart) {
6106 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6107 lockstart + len - 1,
6108 unlock_bits | EXTENT_DEFRAG, 1, 0,
6109 &cached_state, GFP_NOFS);
6110 /*
6111 * Beside unlock, we also need to cleanup reserved space
6112 * for the left range by attaching EXTENT_DO_ACCOUNTING.
6113 */
6114 clear_extent_bit(&BTRFS_I(inode)->io_tree,
6115 lockstart + len, lockend,
6116 unlock_bits | EXTENT_DO_ACCOUNTING |
6117 EXTENT_DEFRAG, 1, 0, NULL, GFP_NOFS);
6118 } else {
6119 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6120 lockend, unlock_bits, 1, 0,
6121 &cached_state, GFP_NOFS);
6122 }
6123 } else {
6124 free_extent_state(cached_state);
6125 }
6126
6127 free_extent_map(em);
6128
6129 return 0;
6130
6131 unlock_err:
6132 if (create)
6133 unlock_bits |= EXTENT_DO_ACCOUNTING;
6134
6135 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6136 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
6137 return ret;
6138 }
6139
6140 struct btrfs_dio_private {
6141 struct inode *inode;
6142 u64 logical_offset;
6143 u64 disk_bytenr;
6144 u64 bytes;
6145 void *private;
6146
6147 /* number of bios pending for this dio */
6148 atomic_t pending_bios;
6149
6150 /* IO errors */
6151 int errors;
6152
6153 struct bio *orig_bio;
6154 };
6155
6156 static void btrfs_endio_direct_read(struct bio *bio, int err)
6157 {
6158 struct btrfs_dio_private *dip = bio->bi_private;
6159 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
6160 struct bio_vec *bvec = bio->bi_io_vec;
6161 struct inode *inode = dip->inode;
6162 struct btrfs_root *root = BTRFS_I(inode)->root;
6163 u64 start;
6164
6165 start = dip->logical_offset;
6166 do {
6167 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
6168 struct page *page = bvec->bv_page;
6169 char *kaddr;
6170 u32 csum = ~(u32)0;
6171 u64 private = ~(u32)0;
6172 unsigned long flags;
6173
6174 if (get_state_private(&BTRFS_I(inode)->io_tree,
6175 start, &private))
6176 goto failed;
6177 local_irq_save(flags);
6178 kaddr = kmap_atomic(page);
6179 csum = btrfs_csum_data(root, kaddr + bvec->bv_offset,
6180 csum, bvec->bv_len);
6181 btrfs_csum_final(csum, (char *)&csum);
6182 kunmap_atomic(kaddr);
6183 local_irq_restore(flags);
6184
6185 flush_dcache_page(bvec->bv_page);
6186 if (csum != private) {
6187 failed:
6188 printk(KERN_ERR "btrfs csum failed ino %llu off"
6189 " %llu csum %u private %u\n",
6190 (unsigned long long)btrfs_ino(inode),
6191 (unsigned long long)start,
6192 csum, (unsigned)private);
6193 err = -EIO;
6194 }
6195 }
6196
6197 start += bvec->bv_len;
6198 bvec++;
6199 } while (bvec <= bvec_end);
6200
6201 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
6202 dip->logical_offset + dip->bytes - 1);
6203 bio->bi_private = dip->private;
6204
6205 kfree(dip);
6206
6207 /* If we had a csum failure make sure to clear the uptodate flag */
6208 if (err)
6209 clear_bit(BIO_UPTODATE, &bio->bi_flags);
6210 dio_end_io(bio, err);
6211 }
6212
6213 static void btrfs_endio_direct_write(struct bio *bio, int err)
6214 {
6215 struct btrfs_dio_private *dip = bio->bi_private;
6216 struct inode *inode = dip->inode;
6217 struct btrfs_root *root = BTRFS_I(inode)->root;
6218 struct btrfs_ordered_extent *ordered = NULL;
6219 u64 ordered_offset = dip->logical_offset;
6220 u64 ordered_bytes = dip->bytes;
6221 int ret;
6222
6223 if (err)
6224 goto out_done;
6225 again:
6226 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
6227 &ordered_offset,
6228 ordered_bytes, !err);
6229 if (!ret)
6230 goto out_test;
6231
6232 ordered->work.func = finish_ordered_fn;
6233 ordered->work.flags = 0;
6234 btrfs_queue_worker(&root->fs_info->endio_write_workers,
6235 &ordered->work);
6236 out_test:
6237 /*
6238 * our bio might span multiple ordered extents. If we haven't
6239 * completed the accounting for the whole dio, go back and try again
6240 */
6241 if (ordered_offset < dip->logical_offset + dip->bytes) {
6242 ordered_bytes = dip->logical_offset + dip->bytes -
6243 ordered_offset;
6244 ordered = NULL;
6245 goto again;
6246 }
6247 out_done:
6248 bio->bi_private = dip->private;
6249
6250 kfree(dip);
6251
6252 /* If we had an error make sure to clear the uptodate flag */
6253 if (err)
6254 clear_bit(BIO_UPTODATE, &bio->bi_flags);
6255 dio_end_io(bio, err);
6256 }
6257
6258 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
6259 struct bio *bio, int mirror_num,
6260 unsigned long bio_flags, u64 offset)
6261 {
6262 int ret;
6263 struct btrfs_root *root = BTRFS_I(inode)->root;
6264 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
6265 BUG_ON(ret); /* -ENOMEM */
6266 return 0;
6267 }
6268
6269 static void btrfs_end_dio_bio(struct bio *bio, int err)
6270 {
6271 struct btrfs_dio_private *dip = bio->bi_private;
6272
6273 if (err) {
6274 printk(KERN_ERR "btrfs direct IO failed ino %llu rw %lu "
6275 "sector %#Lx len %u err no %d\n",
6276 (unsigned long long)btrfs_ino(dip->inode), bio->bi_rw,
6277 (unsigned long long)bio->bi_sector, bio->bi_size, err);
6278 dip->errors = 1;
6279
6280 /*
6281 * before atomic variable goto zero, we must make sure
6282 * dip->errors is perceived to be set.
6283 */
6284 smp_mb__before_atomic_dec();
6285 }
6286
6287 /* if there are more bios still pending for this dio, just exit */
6288 if (!atomic_dec_and_test(&dip->pending_bios))
6289 goto out;
6290
6291 if (dip->errors)
6292 bio_io_error(dip->orig_bio);
6293 else {
6294 set_bit(BIO_UPTODATE, &dip->orig_bio->bi_flags);
6295 bio_endio(dip->orig_bio, 0);
6296 }
6297 out:
6298 bio_put(bio);
6299 }
6300
6301 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
6302 u64 first_sector, gfp_t gfp_flags)
6303 {
6304 int nr_vecs = bio_get_nr_vecs(bdev);
6305 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
6306 }
6307
6308 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
6309 int rw, u64 file_offset, int skip_sum,
6310 int async_submit)
6311 {
6312 int write = rw & REQ_WRITE;
6313 struct btrfs_root *root = BTRFS_I(inode)->root;
6314 int ret;
6315
6316 if (async_submit)
6317 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
6318
6319 bio_get(bio);
6320
6321 if (!write) {
6322 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
6323 if (ret)
6324 goto err;
6325 }
6326
6327 if (skip_sum)
6328 goto map;
6329
6330 if (write && async_submit) {
6331 ret = btrfs_wq_submit_bio(root->fs_info,
6332 inode, rw, bio, 0, 0,
6333 file_offset,
6334 __btrfs_submit_bio_start_direct_io,
6335 __btrfs_submit_bio_done);
6336 goto err;
6337 } else if (write) {
6338 /*
6339 * If we aren't doing async submit, calculate the csum of the
6340 * bio now.
6341 */
6342 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
6343 if (ret)
6344 goto err;
6345 } else if (!skip_sum) {
6346 ret = btrfs_lookup_bio_sums_dio(root, inode, bio, file_offset);
6347 if (ret)
6348 goto err;
6349 }
6350
6351 map:
6352 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
6353 err:
6354 bio_put(bio);
6355 return ret;
6356 }
6357
6358 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
6359 int skip_sum)
6360 {
6361 struct inode *inode = dip->inode;
6362 struct btrfs_root *root = BTRFS_I(inode)->root;
6363 struct bio *bio;
6364 struct bio *orig_bio = dip->orig_bio;
6365 struct bio_vec *bvec = orig_bio->bi_io_vec;
6366 u64 start_sector = orig_bio->bi_sector;
6367 u64 file_offset = dip->logical_offset;
6368 u64 submit_len = 0;
6369 u64 map_length;
6370 int nr_pages = 0;
6371 int ret = 0;
6372 int async_submit = 0;
6373
6374 map_length = orig_bio->bi_size;
6375 ret = btrfs_map_block(root->fs_info, READ, start_sector << 9,
6376 &map_length, NULL, 0);
6377 if (ret) {
6378 bio_put(orig_bio);
6379 return -EIO;
6380 }
6381
6382 if (map_length >= orig_bio->bi_size) {
6383 bio = orig_bio;
6384 goto submit;
6385 }
6386
6387 async_submit = 1;
6388 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
6389 if (!bio)
6390 return -ENOMEM;
6391 bio->bi_private = dip;
6392 bio->bi_end_io = btrfs_end_dio_bio;
6393 atomic_inc(&dip->pending_bios);
6394
6395 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
6396 if (unlikely(map_length < submit_len + bvec->bv_len ||
6397 bio_add_page(bio, bvec->bv_page, bvec->bv_len,
6398 bvec->bv_offset) < bvec->bv_len)) {
6399 /*
6400 * inc the count before we submit the bio so
6401 * we know the end IO handler won't happen before
6402 * we inc the count. Otherwise, the dip might get freed
6403 * before we're done setting it up
6404 */
6405 atomic_inc(&dip->pending_bios);
6406 ret = __btrfs_submit_dio_bio(bio, inode, rw,
6407 file_offset, skip_sum,
6408 async_submit);
6409 if (ret) {
6410 bio_put(bio);
6411 atomic_dec(&dip->pending_bios);
6412 goto out_err;
6413 }
6414
6415 start_sector += submit_len >> 9;
6416 file_offset += submit_len;
6417
6418 submit_len = 0;
6419 nr_pages = 0;
6420
6421 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
6422 start_sector, GFP_NOFS);
6423 if (!bio)
6424 goto out_err;
6425 bio->bi_private = dip;
6426 bio->bi_end_io = btrfs_end_dio_bio;
6427
6428 map_length = orig_bio->bi_size;
6429 ret = btrfs_map_block(root->fs_info, READ,
6430 start_sector << 9,
6431 &map_length, NULL, 0);
6432 if (ret) {
6433 bio_put(bio);
6434 goto out_err;
6435 }
6436 } else {
6437 submit_len += bvec->bv_len;
6438 nr_pages ++;
6439 bvec++;
6440 }
6441 }
6442
6443 submit:
6444 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
6445 async_submit);
6446 if (!ret)
6447 return 0;
6448
6449 bio_put(bio);
6450 out_err:
6451 dip->errors = 1;
6452 /*
6453 * before atomic variable goto zero, we must
6454 * make sure dip->errors is perceived to be set.
6455 */
6456 smp_mb__before_atomic_dec();
6457 if (atomic_dec_and_test(&dip->pending_bios))
6458 bio_io_error(dip->orig_bio);
6459
6460 /* bio_end_io() will handle error, so we needn't return it */
6461 return 0;
6462 }
6463
6464 static void btrfs_submit_direct(int rw, struct bio *bio, struct inode *inode,
6465 loff_t file_offset)
6466 {
6467 struct btrfs_root *root = BTRFS_I(inode)->root;
6468 struct btrfs_dio_private *dip;
6469 struct bio_vec *bvec = bio->bi_io_vec;
6470 int skip_sum;
6471 int write = rw & REQ_WRITE;
6472 int ret = 0;
6473
6474 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
6475
6476 dip = kmalloc(sizeof(*dip), GFP_NOFS);
6477 if (!dip) {
6478 ret = -ENOMEM;
6479 goto free_ordered;
6480 }
6481
6482 dip->private = bio->bi_private;
6483 dip->inode = inode;
6484 dip->logical_offset = file_offset;
6485
6486 dip->bytes = 0;
6487 do {
6488 dip->bytes += bvec->bv_len;
6489 bvec++;
6490 } while (bvec <= (bio->bi_io_vec + bio->bi_vcnt - 1));
6491
6492 dip->disk_bytenr = (u64)bio->bi_sector << 9;
6493 bio->bi_private = dip;
6494 dip->errors = 0;
6495 dip->orig_bio = bio;
6496 atomic_set(&dip->pending_bios, 0);
6497
6498 if (write)
6499 bio->bi_end_io = btrfs_endio_direct_write;
6500 else
6501 bio->bi_end_io = btrfs_endio_direct_read;
6502
6503 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
6504 if (!ret)
6505 return;
6506 free_ordered:
6507 /*
6508 * If this is a write, we need to clean up the reserved space and kill
6509 * the ordered extent.
6510 */
6511 if (write) {
6512 struct btrfs_ordered_extent *ordered;
6513 ordered = btrfs_lookup_ordered_extent(inode, file_offset);
6514 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
6515 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
6516 btrfs_free_reserved_extent(root, ordered->start,
6517 ordered->disk_len);
6518 btrfs_put_ordered_extent(ordered);
6519 btrfs_put_ordered_extent(ordered);
6520 }
6521 bio_endio(bio, ret);
6522 }
6523
6524 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb,
6525 const struct iovec *iov, loff_t offset,
6526 unsigned long nr_segs)
6527 {
6528 int seg;
6529 int i;
6530 size_t size;
6531 unsigned long addr;
6532 unsigned blocksize_mask = root->sectorsize - 1;
6533 ssize_t retval = -EINVAL;
6534 loff_t end = offset;
6535
6536 if (offset & blocksize_mask)
6537 goto out;
6538
6539 /* Check the memory alignment. Blocks cannot straddle pages */
6540 for (seg = 0; seg < nr_segs; seg++) {
6541 addr = (unsigned long)iov[seg].iov_base;
6542 size = iov[seg].iov_len;
6543 end += size;
6544 if ((addr & blocksize_mask) || (size & blocksize_mask))
6545 goto out;
6546
6547 /* If this is a write we don't need to check anymore */
6548 if (rw & WRITE)
6549 continue;
6550
6551 /*
6552 * Check to make sure we don't have duplicate iov_base's in this
6553 * iovec, if so return EINVAL, otherwise we'll get csum errors
6554 * when reading back.
6555 */
6556 for (i = seg + 1; i < nr_segs; i++) {
6557 if (iov[seg].iov_base == iov[i].iov_base)
6558 goto out;
6559 }
6560 }
6561 retval = 0;
6562 out:
6563 return retval;
6564 }
6565
6566 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
6567 const struct iovec *iov, loff_t offset,
6568 unsigned long nr_segs)
6569 {
6570 struct file *file = iocb->ki_filp;
6571 struct inode *inode = file->f_mapping->host;
6572
6573 if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
6574 offset, nr_segs))
6575 return 0;
6576
6577 return __blockdev_direct_IO(rw, iocb, inode,
6578 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
6579 iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
6580 btrfs_submit_direct, 0);
6581 }
6582
6583 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
6584
6585 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
6586 __u64 start, __u64 len)
6587 {
6588 int ret;
6589
6590 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
6591 if (ret)
6592 return ret;
6593
6594 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
6595 }
6596
6597 int btrfs_readpage(struct file *file, struct page *page)
6598 {
6599 struct extent_io_tree *tree;
6600 tree = &BTRFS_I(page->mapping->host)->io_tree;
6601 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
6602 }
6603
6604 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
6605 {
6606 struct extent_io_tree *tree;
6607
6608
6609 if (current->flags & PF_MEMALLOC) {
6610 redirty_page_for_writepage(wbc, page);
6611 unlock_page(page);
6612 return 0;
6613 }
6614 tree = &BTRFS_I(page->mapping->host)->io_tree;
6615 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
6616 }
6617
6618 int btrfs_writepages(struct address_space *mapping,
6619 struct writeback_control *wbc)
6620 {
6621 struct extent_io_tree *tree;
6622
6623 tree = &BTRFS_I(mapping->host)->io_tree;
6624 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
6625 }
6626
6627 static int
6628 btrfs_readpages(struct file *file, struct address_space *mapping,
6629 struct list_head *pages, unsigned nr_pages)
6630 {
6631 struct extent_io_tree *tree;
6632 tree = &BTRFS_I(mapping->host)->io_tree;
6633 return extent_readpages(tree, mapping, pages, nr_pages,
6634 btrfs_get_extent);
6635 }
6636 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
6637 {
6638 struct extent_io_tree *tree;
6639 struct extent_map_tree *map;
6640 int ret;
6641
6642 tree = &BTRFS_I(page->mapping->host)->io_tree;
6643 map = &BTRFS_I(page->mapping->host)->extent_tree;
6644 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
6645 if (ret == 1) {
6646 ClearPagePrivate(page);
6647 set_page_private(page, 0);
6648 page_cache_release(page);
6649 }
6650 return ret;
6651 }
6652
6653 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
6654 {
6655 if (PageWriteback(page) || PageDirty(page))
6656 return 0;
6657 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
6658 }
6659
6660 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
6661 {
6662 struct inode *inode = page->mapping->host;
6663 struct extent_io_tree *tree;
6664 struct btrfs_ordered_extent *ordered;
6665 struct extent_state *cached_state = NULL;
6666 u64 page_start = page_offset(page);
6667 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
6668
6669 /*
6670 * we have the page locked, so new writeback can't start,
6671 * and the dirty bit won't be cleared while we are here.
6672 *
6673 * Wait for IO on this page so that we can safely clear
6674 * the PagePrivate2 bit and do ordered accounting
6675 */
6676 wait_on_page_writeback(page);
6677
6678 tree = &BTRFS_I(inode)->io_tree;
6679 if (offset) {
6680 btrfs_releasepage(page, GFP_NOFS);
6681 return;
6682 }
6683 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
6684 ordered = btrfs_lookup_ordered_extent(inode,
6685 page_offset(page));
6686 if (ordered) {
6687 /*
6688 * IO on this page will never be started, so we need
6689 * to account for any ordered extents now
6690 */
6691 clear_extent_bit(tree, page_start, page_end,
6692 EXTENT_DIRTY | EXTENT_DELALLOC |
6693 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
6694 EXTENT_DEFRAG, 1, 0, &cached_state, GFP_NOFS);
6695 /*
6696 * whoever cleared the private bit is responsible
6697 * for the finish_ordered_io
6698 */
6699 if (TestClearPagePrivate2(page) &&
6700 btrfs_dec_test_ordered_pending(inode, &ordered, page_start,
6701 PAGE_CACHE_SIZE, 1)) {
6702 btrfs_finish_ordered_io(ordered);
6703 }
6704 btrfs_put_ordered_extent(ordered);
6705 cached_state = NULL;
6706 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
6707 }
6708 clear_extent_bit(tree, page_start, page_end,
6709 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
6710 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
6711 &cached_state, GFP_NOFS);
6712 __btrfs_releasepage(page, GFP_NOFS);
6713
6714 ClearPageChecked(page);
6715 if (PagePrivate(page)) {
6716 ClearPagePrivate(page);
6717 set_page_private(page, 0);
6718 page_cache_release(page);
6719 }
6720 }
6721
6722 /*
6723 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
6724 * called from a page fault handler when a page is first dirtied. Hence we must
6725 * be careful to check for EOF conditions here. We set the page up correctly
6726 * for a written page which means we get ENOSPC checking when writing into
6727 * holes and correct delalloc and unwritten extent mapping on filesystems that
6728 * support these features.
6729 *
6730 * We are not allowed to take the i_mutex here so we have to play games to
6731 * protect against truncate races as the page could now be beyond EOF. Because
6732 * vmtruncate() writes the inode size before removing pages, once we have the
6733 * page lock we can determine safely if the page is beyond EOF. If it is not
6734 * beyond EOF, then the page is guaranteed safe against truncation until we
6735 * unlock the page.
6736 */
6737 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
6738 {
6739 struct page *page = vmf->page;
6740 struct inode *inode = fdentry(vma->vm_file)->d_inode;
6741 struct btrfs_root *root = BTRFS_I(inode)->root;
6742 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6743 struct btrfs_ordered_extent *ordered;
6744 struct extent_state *cached_state = NULL;
6745 char *kaddr;
6746 unsigned long zero_start;
6747 loff_t size;
6748 int ret;
6749 int reserved = 0;
6750 u64 page_start;
6751 u64 page_end;
6752
6753 sb_start_pagefault(inode->i_sb);
6754 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
6755 if (!ret) {
6756 ret = file_update_time(vma->vm_file);
6757 reserved = 1;
6758 }
6759 if (ret) {
6760 if (ret == -ENOMEM)
6761 ret = VM_FAULT_OOM;
6762 else /* -ENOSPC, -EIO, etc */
6763 ret = VM_FAULT_SIGBUS;
6764 if (reserved)
6765 goto out;
6766 goto out_noreserve;
6767 }
6768
6769 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
6770 again:
6771 lock_page(page);
6772 size = i_size_read(inode);
6773 page_start = page_offset(page);
6774 page_end = page_start + PAGE_CACHE_SIZE - 1;
6775
6776 if ((page->mapping != inode->i_mapping) ||
6777 (page_start >= size)) {
6778 /* page got truncated out from underneath us */
6779 goto out_unlock;
6780 }
6781 wait_on_page_writeback(page);
6782
6783 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
6784 set_page_extent_mapped(page);
6785
6786 /*
6787 * we can't set the delalloc bits if there are pending ordered
6788 * extents. Drop our locks and wait for them to finish
6789 */
6790 ordered = btrfs_lookup_ordered_extent(inode, page_start);
6791 if (ordered) {
6792 unlock_extent_cached(io_tree, page_start, page_end,
6793 &cached_state, GFP_NOFS);
6794 unlock_page(page);
6795 btrfs_start_ordered_extent(inode, ordered, 1);
6796 btrfs_put_ordered_extent(ordered);
6797 goto again;
6798 }
6799
6800 /*
6801 * XXX - page_mkwrite gets called every time the page is dirtied, even
6802 * if it was already dirty, so for space accounting reasons we need to
6803 * clear any delalloc bits for the range we are fixing to save. There
6804 * is probably a better way to do this, but for now keep consistent with
6805 * prepare_pages in the normal write path.
6806 */
6807 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
6808 EXTENT_DIRTY | EXTENT_DELALLOC |
6809 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
6810 0, 0, &cached_state, GFP_NOFS);
6811
6812 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
6813 &cached_state);
6814 if (ret) {
6815 unlock_extent_cached(io_tree, page_start, page_end,
6816 &cached_state, GFP_NOFS);
6817 ret = VM_FAULT_SIGBUS;
6818 goto out_unlock;
6819 }
6820 ret = 0;
6821
6822 /* page is wholly or partially inside EOF */
6823 if (page_start + PAGE_CACHE_SIZE > size)
6824 zero_start = size & ~PAGE_CACHE_MASK;
6825 else
6826 zero_start = PAGE_CACHE_SIZE;
6827
6828 if (zero_start != PAGE_CACHE_SIZE) {
6829 kaddr = kmap(page);
6830 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
6831 flush_dcache_page(page);
6832 kunmap(page);
6833 }
6834 ClearPageChecked(page);
6835 set_page_dirty(page);
6836 SetPageUptodate(page);
6837
6838 BTRFS_I(inode)->last_trans = root->fs_info->generation;
6839 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
6840 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
6841
6842 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
6843
6844 out_unlock:
6845 if (!ret) {
6846 sb_end_pagefault(inode->i_sb);
6847 return VM_FAULT_LOCKED;
6848 }
6849 unlock_page(page);
6850 out:
6851 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
6852 out_noreserve:
6853 sb_end_pagefault(inode->i_sb);
6854 return ret;
6855 }
6856
6857 static int btrfs_truncate(struct inode *inode)
6858 {
6859 struct btrfs_root *root = BTRFS_I(inode)->root;
6860 struct btrfs_block_rsv *rsv;
6861 int ret;
6862 int err = 0;
6863 struct btrfs_trans_handle *trans;
6864 u64 mask = root->sectorsize - 1;
6865 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
6866
6867 ret = btrfs_truncate_page(inode, inode->i_size, 0, 0);
6868 if (ret)
6869 return ret;
6870
6871 btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
6872 btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
6873
6874 /*
6875 * Yes ladies and gentelment, this is indeed ugly. The fact is we have
6876 * 3 things going on here
6877 *
6878 * 1) We need to reserve space for our orphan item and the space to
6879 * delete our orphan item. Lord knows we don't want to have a dangling
6880 * orphan item because we didn't reserve space to remove it.
6881 *
6882 * 2) We need to reserve space to update our inode.
6883 *
6884 * 3) We need to have something to cache all the space that is going to
6885 * be free'd up by the truncate operation, but also have some slack
6886 * space reserved in case it uses space during the truncate (thank you
6887 * very much snapshotting).
6888 *
6889 * And we need these to all be seperate. The fact is we can use alot of
6890 * space doing the truncate, and we have no earthly idea how much space
6891 * we will use, so we need the truncate reservation to be seperate so it
6892 * doesn't end up using space reserved for updating the inode or
6893 * removing the orphan item. We also need to be able to stop the
6894 * transaction and start a new one, which means we need to be able to
6895 * update the inode several times, and we have no idea of knowing how
6896 * many times that will be, so we can't just reserve 1 item for the
6897 * entirety of the opration, so that has to be done seperately as well.
6898 * Then there is the orphan item, which does indeed need to be held on
6899 * to for the whole operation, and we need nobody to touch this reserved
6900 * space except the orphan code.
6901 *
6902 * So that leaves us with
6903 *
6904 * 1) root->orphan_block_rsv - for the orphan deletion.
6905 * 2) rsv - for the truncate reservation, which we will steal from the
6906 * transaction reservation.
6907 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
6908 * updating the inode.
6909 */
6910 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
6911 if (!rsv)
6912 return -ENOMEM;
6913 rsv->size = min_size;
6914 rsv->failfast = 1;
6915
6916 /*
6917 * 1 for the truncate slack space
6918 * 1 for the orphan item we're going to add
6919 * 1 for the orphan item deletion
6920 * 1 for updating the inode.
6921 */
6922 trans = btrfs_start_transaction(root, 4);
6923 if (IS_ERR(trans)) {
6924 err = PTR_ERR(trans);
6925 goto out;
6926 }
6927
6928 /* Migrate the slack space for the truncate to our reserve */
6929 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
6930 min_size);
6931 BUG_ON(ret);
6932
6933 ret = btrfs_orphan_add(trans, inode);
6934 if (ret) {
6935 btrfs_end_transaction(trans, root);
6936 goto out;
6937 }
6938
6939 /*
6940 * setattr is responsible for setting the ordered_data_close flag,
6941 * but that is only tested during the last file release. That
6942 * could happen well after the next commit, leaving a great big
6943 * window where new writes may get lost if someone chooses to write
6944 * to this file after truncating to zero
6945 *
6946 * The inode doesn't have any dirty data here, and so if we commit
6947 * this is a noop. If someone immediately starts writing to the inode
6948 * it is very likely we'll catch some of their writes in this
6949 * transaction, and the commit will find this file on the ordered
6950 * data list with good things to send down.
6951 *
6952 * This is a best effort solution, there is still a window where
6953 * using truncate to replace the contents of the file will
6954 * end up with a zero length file after a crash.
6955 */
6956 if (inode->i_size == 0 && test_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
6957 &BTRFS_I(inode)->runtime_flags))
6958 btrfs_add_ordered_operation(trans, root, inode);
6959
6960 /*
6961 * So if we truncate and then write and fsync we normally would just
6962 * write the extents that changed, which is a problem if we need to
6963 * first truncate that entire inode. So set this flag so we write out
6964 * all of the extents in the inode to the sync log so we're completely
6965 * safe.
6966 */
6967 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6968 trans->block_rsv = rsv;
6969
6970 while (1) {
6971 ret = btrfs_truncate_inode_items(trans, root, inode,
6972 inode->i_size,
6973 BTRFS_EXTENT_DATA_KEY);
6974 if (ret != -ENOSPC) {
6975 err = ret;
6976 break;
6977 }
6978
6979 trans->block_rsv = &root->fs_info->trans_block_rsv;
6980 ret = btrfs_update_inode(trans, root, inode);
6981 if (ret) {
6982 err = ret;
6983 break;
6984 }
6985
6986 btrfs_end_transaction(trans, root);
6987 btrfs_btree_balance_dirty(root);
6988
6989 trans = btrfs_start_transaction(root, 2);
6990 if (IS_ERR(trans)) {
6991 ret = err = PTR_ERR(trans);
6992 trans = NULL;
6993 break;
6994 }
6995
6996 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
6997 rsv, min_size);
6998 BUG_ON(ret); /* shouldn't happen */
6999 trans->block_rsv = rsv;
7000 }
7001
7002 if (ret == 0 && inode->i_nlink > 0) {
7003 trans->block_rsv = root->orphan_block_rsv;
7004 ret = btrfs_orphan_del(trans, inode);
7005 if (ret)
7006 err = ret;
7007 } else if (ret && inode->i_nlink > 0) {
7008 /*
7009 * Failed to do the truncate, remove us from the in memory
7010 * orphan list.
7011 */
7012 ret = btrfs_orphan_del(NULL, inode);
7013 }
7014
7015 if (trans) {
7016 trans->block_rsv = &root->fs_info->trans_block_rsv;
7017 ret = btrfs_update_inode(trans, root, inode);
7018 if (ret && !err)
7019 err = ret;
7020
7021 ret = btrfs_end_transaction(trans, root);
7022 btrfs_btree_balance_dirty(root);
7023 }
7024
7025 out:
7026 btrfs_free_block_rsv(root, rsv);
7027
7028 if (ret && !err)
7029 err = ret;
7030
7031 return err;
7032 }
7033
7034 /*
7035 * create a new subvolume directory/inode (helper for the ioctl).
7036 */
7037 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
7038 struct btrfs_root *new_root, u64 new_dirid)
7039 {
7040 struct inode *inode;
7041 int err;
7042 u64 index = 0;
7043
7044 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
7045 new_dirid, new_dirid,
7046 S_IFDIR | (~current_umask() & S_IRWXUGO),
7047 &index);
7048 if (IS_ERR(inode))
7049 return PTR_ERR(inode);
7050 inode->i_op = &btrfs_dir_inode_operations;
7051 inode->i_fop = &btrfs_dir_file_operations;
7052
7053 set_nlink(inode, 1);
7054 btrfs_i_size_write(inode, 0);
7055
7056 err = btrfs_update_inode(trans, new_root, inode);
7057
7058 iput(inode);
7059 return err;
7060 }
7061
7062 struct inode *btrfs_alloc_inode(struct super_block *sb)
7063 {
7064 struct btrfs_inode *ei;
7065 struct inode *inode;
7066
7067 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
7068 if (!ei)
7069 return NULL;
7070
7071 ei->root = NULL;
7072 ei->generation = 0;
7073 ei->last_trans = 0;
7074 ei->last_sub_trans = 0;
7075 ei->logged_trans = 0;
7076 ei->delalloc_bytes = 0;
7077 ei->disk_i_size = 0;
7078 ei->flags = 0;
7079 ei->csum_bytes = 0;
7080 ei->index_cnt = (u64)-1;
7081 ei->last_unlink_trans = 0;
7082 ei->last_log_commit = 0;
7083
7084 spin_lock_init(&ei->lock);
7085 ei->outstanding_extents = 0;
7086 ei->reserved_extents = 0;
7087
7088 ei->runtime_flags = 0;
7089 ei->force_compress = BTRFS_COMPRESS_NONE;
7090
7091 ei->delayed_node = NULL;
7092
7093 inode = &ei->vfs_inode;
7094 extent_map_tree_init(&ei->extent_tree);
7095 extent_io_tree_init(&ei->io_tree, &inode->i_data);
7096 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
7097 ei->io_tree.track_uptodate = 1;
7098 ei->io_failure_tree.track_uptodate = 1;
7099 atomic_set(&ei->sync_writers, 0);
7100 mutex_init(&ei->log_mutex);
7101 mutex_init(&ei->delalloc_mutex);
7102 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
7103 INIT_LIST_HEAD(&ei->delalloc_inodes);
7104 INIT_LIST_HEAD(&ei->ordered_operations);
7105 RB_CLEAR_NODE(&ei->rb_node);
7106
7107 return inode;
7108 }
7109
7110 static void btrfs_i_callback(struct rcu_head *head)
7111 {
7112 struct inode *inode = container_of(head, struct inode, i_rcu);
7113 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
7114 }
7115
7116 void btrfs_destroy_inode(struct inode *inode)
7117 {
7118 struct btrfs_ordered_extent *ordered;
7119 struct btrfs_root *root = BTRFS_I(inode)->root;
7120
7121 WARN_ON(!hlist_empty(&inode->i_dentry));
7122 WARN_ON(inode->i_data.nrpages);
7123 WARN_ON(BTRFS_I(inode)->outstanding_extents);
7124 WARN_ON(BTRFS_I(inode)->reserved_extents);
7125 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
7126 WARN_ON(BTRFS_I(inode)->csum_bytes);
7127
7128 /*
7129 * This can happen where we create an inode, but somebody else also
7130 * created the same inode and we need to destroy the one we already
7131 * created.
7132 */
7133 if (!root)
7134 goto free;
7135
7136 /*
7137 * Make sure we're properly removed from the ordered operation
7138 * lists.
7139 */
7140 smp_mb();
7141 if (!list_empty(&BTRFS_I(inode)->ordered_operations)) {
7142 spin_lock(&root->fs_info->ordered_extent_lock);
7143 list_del_init(&BTRFS_I(inode)->ordered_operations);
7144 spin_unlock(&root->fs_info->ordered_extent_lock);
7145 }
7146
7147 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
7148 &BTRFS_I(inode)->runtime_flags)) {
7149 printk(KERN_INFO "BTRFS: inode %llu still on the orphan list\n",
7150 (unsigned long long)btrfs_ino(inode));
7151 atomic_dec(&root->orphan_inodes);
7152 }
7153
7154 while (1) {
7155 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
7156 if (!ordered)
7157 break;
7158 else {
7159 printk(KERN_ERR "btrfs found ordered "
7160 "extent %llu %llu on inode cleanup\n",
7161 (unsigned long long)ordered->file_offset,
7162 (unsigned long long)ordered->len);
7163 btrfs_remove_ordered_extent(inode, ordered);
7164 btrfs_put_ordered_extent(ordered);
7165 btrfs_put_ordered_extent(ordered);
7166 }
7167 }
7168 inode_tree_del(inode);
7169 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
7170 free:
7171 btrfs_remove_delayed_node(inode);
7172 call_rcu(&inode->i_rcu, btrfs_i_callback);
7173 }
7174
7175 int btrfs_drop_inode(struct inode *inode)
7176 {
7177 struct btrfs_root *root = BTRFS_I(inode)->root;
7178
7179 if (btrfs_root_refs(&root->root_item) == 0 &&
7180 !btrfs_is_free_space_inode(inode))
7181 return 1;
7182 else
7183 return generic_drop_inode(inode);
7184 }
7185
7186 static void init_once(void *foo)
7187 {
7188 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
7189
7190 inode_init_once(&ei->vfs_inode);
7191 }
7192
7193 void btrfs_destroy_cachep(void)
7194 {
7195 /*
7196 * Make sure all delayed rcu free inodes are flushed before we
7197 * destroy cache.
7198 */
7199 rcu_barrier();
7200 if (btrfs_inode_cachep)
7201 kmem_cache_destroy(btrfs_inode_cachep);
7202 if (btrfs_trans_handle_cachep)
7203 kmem_cache_destroy(btrfs_trans_handle_cachep);
7204 if (btrfs_transaction_cachep)
7205 kmem_cache_destroy(btrfs_transaction_cachep);
7206 if (btrfs_path_cachep)
7207 kmem_cache_destroy(btrfs_path_cachep);
7208 if (btrfs_free_space_cachep)
7209 kmem_cache_destroy(btrfs_free_space_cachep);
7210 if (btrfs_delalloc_work_cachep)
7211 kmem_cache_destroy(btrfs_delalloc_work_cachep);
7212 }
7213
7214 int btrfs_init_cachep(void)
7215 {
7216 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
7217 sizeof(struct btrfs_inode), 0,
7218 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
7219 if (!btrfs_inode_cachep)
7220 goto fail;
7221
7222 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
7223 sizeof(struct btrfs_trans_handle), 0,
7224 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7225 if (!btrfs_trans_handle_cachep)
7226 goto fail;
7227
7228 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
7229 sizeof(struct btrfs_transaction), 0,
7230 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7231 if (!btrfs_transaction_cachep)
7232 goto fail;
7233
7234 btrfs_path_cachep = kmem_cache_create("btrfs_path",
7235 sizeof(struct btrfs_path), 0,
7236 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7237 if (!btrfs_path_cachep)
7238 goto fail;
7239
7240 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
7241 sizeof(struct btrfs_free_space), 0,
7242 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7243 if (!btrfs_free_space_cachep)
7244 goto fail;
7245
7246 btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work",
7247 sizeof(struct btrfs_delalloc_work), 0,
7248 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
7249 NULL);
7250 if (!btrfs_delalloc_work_cachep)
7251 goto fail;
7252
7253 return 0;
7254 fail:
7255 btrfs_destroy_cachep();
7256 return -ENOMEM;
7257 }
7258
7259 static int btrfs_getattr(struct vfsmount *mnt,
7260 struct dentry *dentry, struct kstat *stat)
7261 {
7262 struct inode *inode = dentry->d_inode;
7263 u32 blocksize = inode->i_sb->s_blocksize;
7264
7265 generic_fillattr(inode, stat);
7266 stat->dev = BTRFS_I(inode)->root->anon_dev;
7267 stat->blksize = PAGE_CACHE_SIZE;
7268 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
7269 ALIGN(BTRFS_I(inode)->delalloc_bytes, blocksize)) >> 9;
7270 return 0;
7271 }
7272
7273 /*
7274 * If a file is moved, it will inherit the cow and compression flags of the new
7275 * directory.
7276 */
7277 static void fixup_inode_flags(struct inode *dir, struct inode *inode)
7278 {
7279 struct btrfs_inode *b_dir = BTRFS_I(dir);
7280 struct btrfs_inode *b_inode = BTRFS_I(inode);
7281
7282 if (b_dir->flags & BTRFS_INODE_NODATACOW)
7283 b_inode->flags |= BTRFS_INODE_NODATACOW;
7284 else
7285 b_inode->flags &= ~BTRFS_INODE_NODATACOW;
7286
7287 if (b_dir->flags & BTRFS_INODE_COMPRESS) {
7288 b_inode->flags |= BTRFS_INODE_COMPRESS;
7289 b_inode->flags &= ~BTRFS_INODE_NOCOMPRESS;
7290 } else {
7291 b_inode->flags &= ~(BTRFS_INODE_COMPRESS |
7292 BTRFS_INODE_NOCOMPRESS);
7293 }
7294 }
7295
7296 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
7297 struct inode *new_dir, struct dentry *new_dentry)
7298 {
7299 struct btrfs_trans_handle *trans;
7300 struct btrfs_root *root = BTRFS_I(old_dir)->root;
7301 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
7302 struct inode *new_inode = new_dentry->d_inode;
7303 struct inode *old_inode = old_dentry->d_inode;
7304 struct timespec ctime = CURRENT_TIME;
7305 u64 index = 0;
7306 u64 root_objectid;
7307 int ret;
7308 u64 old_ino = btrfs_ino(old_inode);
7309
7310 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
7311 return -EPERM;
7312
7313 /* we only allow rename subvolume link between subvolumes */
7314 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
7315 return -EXDEV;
7316
7317 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
7318 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
7319 return -ENOTEMPTY;
7320
7321 if (S_ISDIR(old_inode->i_mode) && new_inode &&
7322 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
7323 return -ENOTEMPTY;
7324
7325
7326 /* check for collisions, even if the name isn't there */
7327 ret = btrfs_check_dir_item_collision(root, new_dir->i_ino,
7328 new_dentry->d_name.name,
7329 new_dentry->d_name.len);
7330
7331 if (ret) {
7332 if (ret == -EEXIST) {
7333 /* we shouldn't get
7334 * eexist without a new_inode */
7335 if (!new_inode) {
7336 WARN_ON(1);
7337 return ret;
7338 }
7339 } else {
7340 /* maybe -EOVERFLOW */
7341 return ret;
7342 }
7343 }
7344 ret = 0;
7345
7346 /*
7347 * we're using rename to replace one file with another.
7348 * and the replacement file is large. Start IO on it now so
7349 * we don't add too much work to the end of the transaction
7350 */
7351 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size &&
7352 old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
7353 filemap_flush(old_inode->i_mapping);
7354
7355 /* close the racy window with snapshot create/destroy ioctl */
7356 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
7357 down_read(&root->fs_info->subvol_sem);
7358 /*
7359 * We want to reserve the absolute worst case amount of items. So if
7360 * both inodes are subvols and we need to unlink them then that would
7361 * require 4 item modifications, but if they are both normal inodes it
7362 * would require 5 item modifications, so we'll assume their normal
7363 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
7364 * should cover the worst case number of items we'll modify.
7365 */
7366 trans = btrfs_start_transaction(root, 20);
7367 if (IS_ERR(trans)) {
7368 ret = PTR_ERR(trans);
7369 goto out_notrans;
7370 }
7371
7372 if (dest != root)
7373 btrfs_record_root_in_trans(trans, dest);
7374
7375 ret = btrfs_set_inode_index(new_dir, &index);
7376 if (ret)
7377 goto out_fail;
7378
7379 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
7380 /* force full log commit if subvolume involved. */
7381 root->fs_info->last_trans_log_full_commit = trans->transid;
7382 } else {
7383 ret = btrfs_insert_inode_ref(trans, dest,
7384 new_dentry->d_name.name,
7385 new_dentry->d_name.len,
7386 old_ino,
7387 btrfs_ino(new_dir), index);
7388 if (ret)
7389 goto out_fail;
7390 /*
7391 * this is an ugly little race, but the rename is required
7392 * to make sure that if we crash, the inode is either at the
7393 * old name or the new one. pinning the log transaction lets
7394 * us make sure we don't allow a log commit to come in after
7395 * we unlink the name but before we add the new name back in.
7396 */
7397 btrfs_pin_log_trans(root);
7398 }
7399 /*
7400 * make sure the inode gets flushed if it is replacing
7401 * something.
7402 */
7403 if (new_inode && new_inode->i_size && S_ISREG(old_inode->i_mode))
7404 btrfs_add_ordered_operation(trans, root, old_inode);
7405
7406 inode_inc_iversion(old_dir);
7407 inode_inc_iversion(new_dir);
7408 inode_inc_iversion(old_inode);
7409 old_dir->i_ctime = old_dir->i_mtime = ctime;
7410 new_dir->i_ctime = new_dir->i_mtime = ctime;
7411 old_inode->i_ctime = ctime;
7412
7413 if (old_dentry->d_parent != new_dentry->d_parent)
7414 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
7415
7416 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
7417 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
7418 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
7419 old_dentry->d_name.name,
7420 old_dentry->d_name.len);
7421 } else {
7422 ret = __btrfs_unlink_inode(trans, root, old_dir,
7423 old_dentry->d_inode,
7424 old_dentry->d_name.name,
7425 old_dentry->d_name.len);
7426 if (!ret)
7427 ret = btrfs_update_inode(trans, root, old_inode);
7428 }
7429 if (ret) {
7430 btrfs_abort_transaction(trans, root, ret);
7431 goto out_fail;
7432 }
7433
7434 if (new_inode) {
7435 inode_inc_iversion(new_inode);
7436 new_inode->i_ctime = CURRENT_TIME;
7437 if (unlikely(btrfs_ino(new_inode) ==
7438 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
7439 root_objectid = BTRFS_I(new_inode)->location.objectid;
7440 ret = btrfs_unlink_subvol(trans, dest, new_dir,
7441 root_objectid,
7442 new_dentry->d_name.name,
7443 new_dentry->d_name.len);
7444 BUG_ON(new_inode->i_nlink == 0);
7445 } else {
7446 ret = btrfs_unlink_inode(trans, dest, new_dir,
7447 new_dentry->d_inode,
7448 new_dentry->d_name.name,
7449 new_dentry->d_name.len);
7450 }
7451 if (!ret && new_inode->i_nlink == 0) {
7452 ret = btrfs_orphan_add(trans, new_dentry->d_inode);
7453 BUG_ON(ret);
7454 }
7455 if (ret) {
7456 btrfs_abort_transaction(trans, root, ret);
7457 goto out_fail;
7458 }
7459 }
7460
7461 fixup_inode_flags(new_dir, old_inode);
7462
7463 ret = btrfs_add_link(trans, new_dir, old_inode,
7464 new_dentry->d_name.name,
7465 new_dentry->d_name.len, 0, index);
7466 if (ret) {
7467 btrfs_abort_transaction(trans, root, ret);
7468 goto out_fail;
7469 }
7470
7471 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
7472 struct dentry *parent = new_dentry->d_parent;
7473 btrfs_log_new_name(trans, old_inode, old_dir, parent);
7474 btrfs_end_log_trans(root);
7475 }
7476 out_fail:
7477 btrfs_end_transaction(trans, root);
7478 out_notrans:
7479 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
7480 up_read(&root->fs_info->subvol_sem);
7481
7482 return ret;
7483 }
7484
7485 static void btrfs_run_delalloc_work(struct btrfs_work *work)
7486 {
7487 struct btrfs_delalloc_work *delalloc_work;
7488
7489 delalloc_work = container_of(work, struct btrfs_delalloc_work,
7490 work);
7491 if (delalloc_work->wait)
7492 btrfs_wait_ordered_range(delalloc_work->inode, 0, (u64)-1);
7493 else
7494 filemap_flush(delalloc_work->inode->i_mapping);
7495
7496 if (delalloc_work->delay_iput)
7497 btrfs_add_delayed_iput(delalloc_work->inode);
7498 else
7499 iput(delalloc_work->inode);
7500 complete(&delalloc_work->completion);
7501 }
7502
7503 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
7504 int wait, int delay_iput)
7505 {
7506 struct btrfs_delalloc_work *work;
7507
7508 work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS);
7509 if (!work)
7510 return NULL;
7511
7512 init_completion(&work->completion);
7513 INIT_LIST_HEAD(&work->list);
7514 work->inode = inode;
7515 work->wait = wait;
7516 work->delay_iput = delay_iput;
7517 work->work.func = btrfs_run_delalloc_work;
7518
7519 return work;
7520 }
7521
7522 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
7523 {
7524 wait_for_completion(&work->completion);
7525 kmem_cache_free(btrfs_delalloc_work_cachep, work);
7526 }
7527
7528 /*
7529 * some fairly slow code that needs optimization. This walks the list
7530 * of all the inodes with pending delalloc and forces them to disk.
7531 */
7532 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
7533 {
7534 struct list_head *head = &root->fs_info->delalloc_inodes;
7535 struct btrfs_inode *binode;
7536 struct inode *inode;
7537 struct btrfs_delalloc_work *work, *next;
7538 struct list_head works;
7539 int ret = 0;
7540
7541 if (root->fs_info->sb->s_flags & MS_RDONLY)
7542 return -EROFS;
7543
7544 INIT_LIST_HEAD(&works);
7545
7546 spin_lock(&root->fs_info->delalloc_lock);
7547 while (!list_empty(head)) {
7548 binode = list_entry(head->next, struct btrfs_inode,
7549 delalloc_inodes);
7550 inode = igrab(&binode->vfs_inode);
7551 if (!inode)
7552 list_del_init(&binode->delalloc_inodes);
7553 spin_unlock(&root->fs_info->delalloc_lock);
7554 if (inode) {
7555 work = btrfs_alloc_delalloc_work(inode, 0, delay_iput);
7556 if (!work) {
7557 ret = -ENOMEM;
7558 goto out;
7559 }
7560 list_add_tail(&work->list, &works);
7561 btrfs_queue_worker(&root->fs_info->flush_workers,
7562 &work->work);
7563 }
7564 cond_resched();
7565 spin_lock(&root->fs_info->delalloc_lock);
7566 }
7567 spin_unlock(&root->fs_info->delalloc_lock);
7568
7569 /* the filemap_flush will queue IO into the worker threads, but
7570 * we have to make sure the IO is actually started and that
7571 * ordered extents get created before we return
7572 */
7573 atomic_inc(&root->fs_info->async_submit_draining);
7574 while (atomic_read(&root->fs_info->nr_async_submits) ||
7575 atomic_read(&root->fs_info->async_delalloc_pages)) {
7576 wait_event(root->fs_info->async_submit_wait,
7577 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
7578 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
7579 }
7580 atomic_dec(&root->fs_info->async_submit_draining);
7581 out:
7582 list_for_each_entry_safe(work, next, &works, list) {
7583 list_del_init(&work->list);
7584 btrfs_wait_and_free_delalloc_work(work);
7585 }
7586 return ret;
7587 }
7588
7589 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
7590 const char *symname)
7591 {
7592 struct btrfs_trans_handle *trans;
7593 struct btrfs_root *root = BTRFS_I(dir)->root;
7594 struct btrfs_path *path;
7595 struct btrfs_key key;
7596 struct inode *inode = NULL;
7597 int err;
7598 int drop_inode = 0;
7599 u64 objectid;
7600 u64 index = 0 ;
7601 int name_len;
7602 int datasize;
7603 unsigned long ptr;
7604 struct btrfs_file_extent_item *ei;
7605 struct extent_buffer *leaf;
7606
7607 name_len = strlen(symname) + 1;
7608 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
7609 return -ENAMETOOLONG;
7610
7611 /*
7612 * 2 items for inode item and ref
7613 * 2 items for dir items
7614 * 1 item for xattr if selinux is on
7615 */
7616 trans = btrfs_start_transaction(root, 5);
7617 if (IS_ERR(trans))
7618 return PTR_ERR(trans);
7619
7620 err = btrfs_find_free_ino(root, &objectid);
7621 if (err)
7622 goto out_unlock;
7623
7624 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
7625 dentry->d_name.len, btrfs_ino(dir), objectid,
7626 S_IFLNK|S_IRWXUGO, &index);
7627 if (IS_ERR(inode)) {
7628 err = PTR_ERR(inode);
7629 goto out_unlock;
7630 }
7631
7632 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
7633 if (err) {
7634 drop_inode = 1;
7635 goto out_unlock;
7636 }
7637
7638 /*
7639 * If the active LSM wants to access the inode during
7640 * d_instantiate it needs these. Smack checks to see
7641 * if the filesystem supports xattrs by looking at the
7642 * ops vector.
7643 */
7644 inode->i_fop = &btrfs_file_operations;
7645 inode->i_op = &btrfs_file_inode_operations;
7646
7647 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
7648 if (err)
7649 drop_inode = 1;
7650 else {
7651 inode->i_mapping->a_ops = &btrfs_aops;
7652 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
7653 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
7654 }
7655 if (drop_inode)
7656 goto out_unlock;
7657
7658 path = btrfs_alloc_path();
7659 if (!path) {
7660 err = -ENOMEM;
7661 drop_inode = 1;
7662 goto out_unlock;
7663 }
7664 key.objectid = btrfs_ino(inode);
7665 key.offset = 0;
7666 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
7667 datasize = btrfs_file_extent_calc_inline_size(name_len);
7668 err = btrfs_insert_empty_item(trans, root, path, &key,
7669 datasize);
7670 if (err) {
7671 drop_inode = 1;
7672 btrfs_free_path(path);
7673 goto out_unlock;
7674 }
7675 leaf = path->nodes[0];
7676 ei = btrfs_item_ptr(leaf, path->slots[0],
7677 struct btrfs_file_extent_item);
7678 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
7679 btrfs_set_file_extent_type(leaf, ei,
7680 BTRFS_FILE_EXTENT_INLINE);
7681 btrfs_set_file_extent_encryption(leaf, ei, 0);
7682 btrfs_set_file_extent_compression(leaf, ei, 0);
7683 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
7684 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
7685
7686 ptr = btrfs_file_extent_inline_start(ei);
7687 write_extent_buffer(leaf, symname, ptr, name_len);
7688 btrfs_mark_buffer_dirty(leaf);
7689 btrfs_free_path(path);
7690
7691 inode->i_op = &btrfs_symlink_inode_operations;
7692 inode->i_mapping->a_ops = &btrfs_symlink_aops;
7693 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
7694 inode_set_bytes(inode, name_len);
7695 btrfs_i_size_write(inode, name_len - 1);
7696 err = btrfs_update_inode(trans, root, inode);
7697 if (err)
7698 drop_inode = 1;
7699
7700 out_unlock:
7701 if (!err)
7702 d_instantiate(dentry, inode);
7703 btrfs_end_transaction(trans, root);
7704 if (drop_inode) {
7705 inode_dec_link_count(inode);
7706 iput(inode);
7707 }
7708 btrfs_btree_balance_dirty(root);
7709 return err;
7710 }
7711
7712 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
7713 u64 start, u64 num_bytes, u64 min_size,
7714 loff_t actual_len, u64 *alloc_hint,
7715 struct btrfs_trans_handle *trans)
7716 {
7717 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
7718 struct extent_map *em;
7719 struct btrfs_root *root = BTRFS_I(inode)->root;
7720 struct btrfs_key ins;
7721 u64 cur_offset = start;
7722 u64 i_size;
7723 int ret = 0;
7724 bool own_trans = true;
7725
7726 if (trans)
7727 own_trans = false;
7728 while (num_bytes > 0) {
7729 if (own_trans) {
7730 trans = btrfs_start_transaction(root, 3);
7731 if (IS_ERR(trans)) {
7732 ret = PTR_ERR(trans);
7733 break;
7734 }
7735 }
7736
7737 ret = btrfs_reserve_extent(trans, root, num_bytes, min_size,
7738 0, *alloc_hint, &ins, 1);
7739 if (ret) {
7740 if (own_trans)
7741 btrfs_end_transaction(trans, root);
7742 break;
7743 }
7744
7745 ret = insert_reserved_file_extent(trans, inode,
7746 cur_offset, ins.objectid,
7747 ins.offset, ins.offset,
7748 ins.offset, 0, 0, 0,
7749 BTRFS_FILE_EXTENT_PREALLOC);
7750 if (ret) {
7751 btrfs_abort_transaction(trans, root, ret);
7752 if (own_trans)
7753 btrfs_end_transaction(trans, root);
7754 break;
7755 }
7756 btrfs_drop_extent_cache(inode, cur_offset,
7757 cur_offset + ins.offset -1, 0);
7758
7759 em = alloc_extent_map();
7760 if (!em) {
7761 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
7762 &BTRFS_I(inode)->runtime_flags);
7763 goto next;
7764 }
7765
7766 em->start = cur_offset;
7767 em->orig_start = cur_offset;
7768 em->len = ins.offset;
7769 em->block_start = ins.objectid;
7770 em->block_len = ins.offset;
7771 em->orig_block_len = ins.offset;
7772 em->bdev = root->fs_info->fs_devices->latest_bdev;
7773 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7774 em->generation = trans->transid;
7775
7776 while (1) {
7777 write_lock(&em_tree->lock);
7778 ret = add_extent_mapping(em_tree, em);
7779 if (!ret)
7780 list_move(&em->list,
7781 &em_tree->modified_extents);
7782 write_unlock(&em_tree->lock);
7783 if (ret != -EEXIST)
7784 break;
7785 btrfs_drop_extent_cache(inode, cur_offset,
7786 cur_offset + ins.offset - 1,
7787 0);
7788 }
7789 free_extent_map(em);
7790 next:
7791 num_bytes -= ins.offset;
7792 cur_offset += ins.offset;
7793 *alloc_hint = ins.objectid + ins.offset;
7794
7795 inode_inc_iversion(inode);
7796 inode->i_ctime = CURRENT_TIME;
7797 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
7798 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
7799 (actual_len > inode->i_size) &&
7800 (cur_offset > inode->i_size)) {
7801 if (cur_offset > actual_len)
7802 i_size = actual_len;
7803 else
7804 i_size = cur_offset;
7805 i_size_write(inode, i_size);
7806 btrfs_ordered_update_i_size(inode, i_size, NULL);
7807 }
7808
7809 ret = btrfs_update_inode(trans, root, inode);
7810
7811 if (ret) {
7812 btrfs_abort_transaction(trans, root, ret);
7813 if (own_trans)
7814 btrfs_end_transaction(trans, root);
7815 break;
7816 }
7817
7818 if (own_trans)
7819 btrfs_end_transaction(trans, root);
7820 }
7821 return ret;
7822 }
7823
7824 int btrfs_prealloc_file_range(struct inode *inode, int mode,
7825 u64 start, u64 num_bytes, u64 min_size,
7826 loff_t actual_len, u64 *alloc_hint)
7827 {
7828 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
7829 min_size, actual_len, alloc_hint,
7830 NULL);
7831 }
7832
7833 int btrfs_prealloc_file_range_trans(struct inode *inode,
7834 struct btrfs_trans_handle *trans, int mode,
7835 u64 start, u64 num_bytes, u64 min_size,
7836 loff_t actual_len, u64 *alloc_hint)
7837 {
7838 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
7839 min_size, actual_len, alloc_hint, trans);
7840 }
7841
7842 static int btrfs_set_page_dirty(struct page *page)
7843 {
7844 return __set_page_dirty_nobuffers(page);
7845 }
7846
7847 static int btrfs_permission(struct inode *inode, int mask)
7848 {
7849 struct btrfs_root *root = BTRFS_I(inode)->root;
7850 umode_t mode = inode->i_mode;
7851
7852 if (mask & MAY_WRITE &&
7853 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
7854 if (btrfs_root_readonly(root))
7855 return -EROFS;
7856 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
7857 return -EACCES;
7858 }
7859 return generic_permission(inode, mask);
7860 }
7861
7862 static const struct inode_operations btrfs_dir_inode_operations = {
7863 .getattr = btrfs_getattr,
7864 .lookup = btrfs_lookup,
7865 .create = btrfs_create,
7866 .unlink = btrfs_unlink,
7867 .link = btrfs_link,
7868 .mkdir = btrfs_mkdir,
7869 .rmdir = btrfs_rmdir,
7870 .rename = btrfs_rename,
7871 .symlink = btrfs_symlink,
7872 .setattr = btrfs_setattr,
7873 .mknod = btrfs_mknod,
7874 .setxattr = btrfs_setxattr,
7875 .getxattr = btrfs_getxattr,
7876 .listxattr = btrfs_listxattr,
7877 .removexattr = btrfs_removexattr,
7878 .permission = btrfs_permission,
7879 .get_acl = btrfs_get_acl,
7880 };
7881 static const struct inode_operations btrfs_dir_ro_inode_operations = {
7882 .lookup = btrfs_lookup,
7883 .permission = btrfs_permission,
7884 .get_acl = btrfs_get_acl,
7885 };
7886
7887 static const struct file_operations btrfs_dir_file_operations = {
7888 .llseek = generic_file_llseek,
7889 .read = generic_read_dir,
7890 .readdir = btrfs_real_readdir,
7891 .unlocked_ioctl = btrfs_ioctl,
7892 #ifdef CONFIG_COMPAT
7893 .compat_ioctl = btrfs_ioctl,
7894 #endif
7895 .release = btrfs_release_file,
7896 .fsync = btrfs_sync_file,
7897 };
7898
7899 static struct extent_io_ops btrfs_extent_io_ops = {
7900 .fill_delalloc = run_delalloc_range,
7901 .submit_bio_hook = btrfs_submit_bio_hook,
7902 .merge_bio_hook = btrfs_merge_bio_hook,
7903 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
7904 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
7905 .writepage_start_hook = btrfs_writepage_start_hook,
7906 .set_bit_hook = btrfs_set_bit_hook,
7907 .clear_bit_hook = btrfs_clear_bit_hook,
7908 .merge_extent_hook = btrfs_merge_extent_hook,
7909 .split_extent_hook = btrfs_split_extent_hook,
7910 };
7911
7912 /*
7913 * btrfs doesn't support the bmap operation because swapfiles
7914 * use bmap to make a mapping of extents in the file. They assume
7915 * these extents won't change over the life of the file and they
7916 * use the bmap result to do IO directly to the drive.
7917 *
7918 * the btrfs bmap call would return logical addresses that aren't
7919 * suitable for IO and they also will change frequently as COW
7920 * operations happen. So, swapfile + btrfs == corruption.
7921 *
7922 * For now we're avoiding this by dropping bmap.
7923 */
7924 static const struct address_space_operations btrfs_aops = {
7925 .readpage = btrfs_readpage,
7926 .writepage = btrfs_writepage,
7927 .writepages = btrfs_writepages,
7928 .readpages = btrfs_readpages,
7929 .direct_IO = btrfs_direct_IO,
7930 .invalidatepage = btrfs_invalidatepage,
7931 .releasepage = btrfs_releasepage,
7932 .set_page_dirty = btrfs_set_page_dirty,
7933 .error_remove_page = generic_error_remove_page,
7934 };
7935
7936 static const struct address_space_operations btrfs_symlink_aops = {
7937 .readpage = btrfs_readpage,
7938 .writepage = btrfs_writepage,
7939 .invalidatepage = btrfs_invalidatepage,
7940 .releasepage = btrfs_releasepage,
7941 };
7942
7943 static const struct inode_operations btrfs_file_inode_operations = {
7944 .getattr = btrfs_getattr,
7945 .setattr = btrfs_setattr,
7946 .setxattr = btrfs_setxattr,
7947 .getxattr = btrfs_getxattr,
7948 .listxattr = btrfs_listxattr,
7949 .removexattr = btrfs_removexattr,
7950 .permission = btrfs_permission,
7951 .fiemap = btrfs_fiemap,
7952 .get_acl = btrfs_get_acl,
7953 .update_time = btrfs_update_time,
7954 };
7955 static const struct inode_operations btrfs_special_inode_operations = {
7956 .getattr = btrfs_getattr,
7957 .setattr = btrfs_setattr,
7958 .permission = btrfs_permission,
7959 .setxattr = btrfs_setxattr,
7960 .getxattr = btrfs_getxattr,
7961 .listxattr = btrfs_listxattr,
7962 .removexattr = btrfs_removexattr,
7963 .get_acl = btrfs_get_acl,
7964 .update_time = btrfs_update_time,
7965 };
7966 static const struct inode_operations btrfs_symlink_inode_operations = {
7967 .readlink = generic_readlink,
7968 .follow_link = page_follow_link_light,
7969 .put_link = page_put_link,
7970 .getattr = btrfs_getattr,
7971 .setattr = btrfs_setattr,
7972 .permission = btrfs_permission,
7973 .setxattr = btrfs_setxattr,
7974 .getxattr = btrfs_getxattr,
7975 .listxattr = btrfs_listxattr,
7976 .removexattr = btrfs_removexattr,
7977 .get_acl = btrfs_get_acl,
7978 .update_time = btrfs_update_time,
7979 };
7980
7981 const struct dentry_operations btrfs_dentry_operations = {
7982 .d_delete = btrfs_dentry_delete,
7983 .d_release = btrfs_dentry_release,
7984 };
CJK support for tty framebuffer vt