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Merge tag 'nios2-v4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/lftan...
[mirror_ubuntu-bionic-kernel.git] / fs / btrfs / inode.c
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 <linux/btrfs.h>
43 #include <linux/blkdev.h>
44 #include <linux/posix_acl_xattr.h>
45 #include <linux/uio.h>
46 #include "ctree.h"
47 #include "disk-io.h"
48 #include "transaction.h"
49 #include "btrfs_inode.h"
50 #include "print-tree.h"
51 #include "ordered-data.h"
52 #include "xattr.h"
53 #include "tree-log.h"
54 #include "volumes.h"
55 #include "compression.h"
56 #include "locking.h"
57 #include "free-space-cache.h"
58 #include "inode-map.h"
59 #include "backref.h"
60 #include "hash.h"
61 #include "props.h"
62 #include "qgroup.h"
63 #include "dedupe.h"
64
65 struct btrfs_iget_args {
66 struct btrfs_key *location;
67 struct btrfs_root *root;
68 };
69
70 struct btrfs_dio_data {
71 u64 outstanding_extents;
72 u64 reserve;
73 u64 unsubmitted_oe_range_start;
74 u64 unsubmitted_oe_range_end;
75 };
76
77 static const struct inode_operations btrfs_dir_inode_operations;
78 static const struct inode_operations btrfs_symlink_inode_operations;
79 static const struct inode_operations btrfs_dir_ro_inode_operations;
80 static const struct inode_operations btrfs_special_inode_operations;
81 static const struct inode_operations btrfs_file_inode_operations;
82 static const struct address_space_operations btrfs_aops;
83 static const struct address_space_operations btrfs_symlink_aops;
84 static const struct file_operations btrfs_dir_file_operations;
85 static const struct extent_io_ops btrfs_extent_io_ops;
86
87 static struct kmem_cache *btrfs_inode_cachep;
88 struct kmem_cache *btrfs_trans_handle_cachep;
89 struct kmem_cache *btrfs_transaction_cachep;
90 struct kmem_cache *btrfs_path_cachep;
91 struct kmem_cache *btrfs_free_space_cachep;
92
93 #define S_SHIFT 12
94 static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
95 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
96 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
97 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
98 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
99 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
100 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
101 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
102 };
103
104 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
105 static int btrfs_truncate(struct inode *inode);
106 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
107 static noinline int cow_file_range(struct inode *inode,
108 struct page *locked_page,
109 u64 start, u64 end, u64 delalloc_end,
110 int *page_started, unsigned long *nr_written,
111 int unlock, struct btrfs_dedupe_hash *hash);
112 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
113 u64 len, u64 orig_start,
114 u64 block_start, u64 block_len,
115 u64 orig_block_len, u64 ram_bytes,
116 int type);
117
118 static int btrfs_dirty_inode(struct inode *inode);
119
120 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
121 void btrfs_test_inode_set_ops(struct inode *inode)
122 {
123 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
124 }
125 #endif
126
127 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
128 struct inode *inode, struct inode *dir,
129 const struct qstr *qstr)
130 {
131 int err;
132
133 err = btrfs_init_acl(trans, inode, dir);
134 if (!err)
135 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
136 return err;
137 }
138
139 /*
140 * this does all the hard work for inserting an inline extent into
141 * the btree. The caller should have done a btrfs_drop_extents so that
142 * no overlapping inline items exist in the btree
143 */
144 static int insert_inline_extent(struct btrfs_trans_handle *trans,
145 struct btrfs_path *path, int extent_inserted,
146 struct btrfs_root *root, struct inode *inode,
147 u64 start, size_t size, size_t compressed_size,
148 int compress_type,
149 struct page **compressed_pages)
150 {
151 struct extent_buffer *leaf;
152 struct page *page = NULL;
153 char *kaddr;
154 unsigned long ptr;
155 struct btrfs_file_extent_item *ei;
156 int err = 0;
157 int ret;
158 size_t cur_size = size;
159 unsigned long offset;
160
161 if (compressed_size && compressed_pages)
162 cur_size = compressed_size;
163
164 inode_add_bytes(inode, size);
165
166 if (!extent_inserted) {
167 struct btrfs_key key;
168 size_t datasize;
169
170 key.objectid = btrfs_ino(inode);
171 key.offset = start;
172 key.type = BTRFS_EXTENT_DATA_KEY;
173
174 datasize = btrfs_file_extent_calc_inline_size(cur_size);
175 path->leave_spinning = 1;
176 ret = btrfs_insert_empty_item(trans, root, path, &key,
177 datasize);
178 if (ret) {
179 err = ret;
180 goto fail;
181 }
182 }
183 leaf = path->nodes[0];
184 ei = btrfs_item_ptr(leaf, path->slots[0],
185 struct btrfs_file_extent_item);
186 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
187 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
188 btrfs_set_file_extent_encryption(leaf, ei, 0);
189 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
190 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
191 ptr = btrfs_file_extent_inline_start(ei);
192
193 if (compress_type != BTRFS_COMPRESS_NONE) {
194 struct page *cpage;
195 int i = 0;
196 while (compressed_size > 0) {
197 cpage = compressed_pages[i];
198 cur_size = min_t(unsigned long, compressed_size,
199 PAGE_SIZE);
200
201 kaddr = kmap_atomic(cpage);
202 write_extent_buffer(leaf, kaddr, ptr, cur_size);
203 kunmap_atomic(kaddr);
204
205 i++;
206 ptr += cur_size;
207 compressed_size -= cur_size;
208 }
209 btrfs_set_file_extent_compression(leaf, ei,
210 compress_type);
211 } else {
212 page = find_get_page(inode->i_mapping,
213 start >> PAGE_SHIFT);
214 btrfs_set_file_extent_compression(leaf, ei, 0);
215 kaddr = kmap_atomic(page);
216 offset = start & (PAGE_SIZE - 1);
217 write_extent_buffer(leaf, kaddr + offset, ptr, size);
218 kunmap_atomic(kaddr);
219 put_page(page);
220 }
221 btrfs_mark_buffer_dirty(leaf);
222 btrfs_release_path(path);
223
224 /*
225 * we're an inline extent, so nobody can
226 * extend the file past i_size without locking
227 * a page we already have locked.
228 *
229 * We must do any isize and inode updates
230 * before we unlock the pages. Otherwise we
231 * could end up racing with unlink.
232 */
233 BTRFS_I(inode)->disk_i_size = inode->i_size;
234 ret = btrfs_update_inode(trans, root, inode);
235
236 return ret;
237 fail:
238 return err;
239 }
240
241
242 /*
243 * conditionally insert an inline extent into the file. This
244 * does the checks required to make sure the data is small enough
245 * to fit as an inline extent.
246 */
247 static noinline int cow_file_range_inline(struct btrfs_root *root,
248 struct inode *inode, u64 start,
249 u64 end, size_t compressed_size,
250 int compress_type,
251 struct page **compressed_pages)
252 {
253 struct btrfs_trans_handle *trans;
254 u64 isize = i_size_read(inode);
255 u64 actual_end = min(end + 1, isize);
256 u64 inline_len = actual_end - start;
257 u64 aligned_end = ALIGN(end, root->sectorsize);
258 u64 data_len = inline_len;
259 int ret;
260 struct btrfs_path *path;
261 int extent_inserted = 0;
262 u32 extent_item_size;
263
264 if (compressed_size)
265 data_len = compressed_size;
266
267 if (start > 0 ||
268 actual_end > root->sectorsize ||
269 data_len > BTRFS_MAX_INLINE_DATA_SIZE(root) ||
270 (!compressed_size &&
271 (actual_end & (root->sectorsize - 1)) == 0) ||
272 end + 1 < isize ||
273 data_len > root->fs_info->max_inline) {
274 return 1;
275 }
276
277 path = btrfs_alloc_path();
278 if (!path)
279 return -ENOMEM;
280
281 trans = btrfs_join_transaction(root);
282 if (IS_ERR(trans)) {
283 btrfs_free_path(path);
284 return PTR_ERR(trans);
285 }
286 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
287
288 if (compressed_size && compressed_pages)
289 extent_item_size = btrfs_file_extent_calc_inline_size(
290 compressed_size);
291 else
292 extent_item_size = btrfs_file_extent_calc_inline_size(
293 inline_len);
294
295 ret = __btrfs_drop_extents(trans, root, inode, path,
296 start, aligned_end, NULL,
297 1, 1, extent_item_size, &extent_inserted);
298 if (ret) {
299 btrfs_abort_transaction(trans, ret);
300 goto out;
301 }
302
303 if (isize > actual_end)
304 inline_len = min_t(u64, isize, actual_end);
305 ret = insert_inline_extent(trans, path, extent_inserted,
306 root, inode, start,
307 inline_len, compressed_size,
308 compress_type, compressed_pages);
309 if (ret && ret != -ENOSPC) {
310 btrfs_abort_transaction(trans, ret);
311 goto out;
312 } else if (ret == -ENOSPC) {
313 ret = 1;
314 goto out;
315 }
316
317 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
318 btrfs_delalloc_release_metadata(inode, end + 1 - start);
319 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
320 out:
321 /*
322 * Don't forget to free the reserved space, as for inlined extent
323 * it won't count as data extent, free them directly here.
324 * And at reserve time, it's always aligned to page size, so
325 * just free one page here.
326 */
327 btrfs_qgroup_free_data(inode, 0, PAGE_SIZE);
328 btrfs_free_path(path);
329 btrfs_end_transaction(trans, root);
330 return ret;
331 }
332
333 struct async_extent {
334 u64 start;
335 u64 ram_size;
336 u64 compressed_size;
337 struct page **pages;
338 unsigned long nr_pages;
339 int compress_type;
340 struct list_head list;
341 };
342
343 struct async_cow {
344 struct inode *inode;
345 struct btrfs_root *root;
346 struct page *locked_page;
347 u64 start;
348 u64 end;
349 struct list_head extents;
350 struct btrfs_work work;
351 };
352
353 static noinline int add_async_extent(struct async_cow *cow,
354 u64 start, u64 ram_size,
355 u64 compressed_size,
356 struct page **pages,
357 unsigned long nr_pages,
358 int compress_type)
359 {
360 struct async_extent *async_extent;
361
362 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
363 BUG_ON(!async_extent); /* -ENOMEM */
364 async_extent->start = start;
365 async_extent->ram_size = ram_size;
366 async_extent->compressed_size = compressed_size;
367 async_extent->pages = pages;
368 async_extent->nr_pages = nr_pages;
369 async_extent->compress_type = compress_type;
370 list_add_tail(&async_extent->list, &cow->extents);
371 return 0;
372 }
373
374 static inline int inode_need_compress(struct inode *inode)
375 {
376 struct btrfs_root *root = BTRFS_I(inode)->root;
377
378 /* force compress */
379 if (btrfs_test_opt(root->fs_info, FORCE_COMPRESS))
380 return 1;
381 /* bad compression ratios */
382 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
383 return 0;
384 if (btrfs_test_opt(root->fs_info, COMPRESS) ||
385 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
386 BTRFS_I(inode)->force_compress)
387 return 1;
388 return 0;
389 }
390
391 /*
392 * we create compressed extents in two phases. The first
393 * phase compresses a range of pages that have already been
394 * locked (both pages and state bits are locked).
395 *
396 * This is done inside an ordered work queue, and the compression
397 * is spread across many cpus. The actual IO submission is step
398 * two, and the ordered work queue takes care of making sure that
399 * happens in the same order things were put onto the queue by
400 * writepages and friends.
401 *
402 * If this code finds it can't get good compression, it puts an
403 * entry onto the work queue to write the uncompressed bytes. This
404 * makes sure that both compressed inodes and uncompressed inodes
405 * are written in the same order that the flusher thread sent them
406 * down.
407 */
408 static noinline void compress_file_range(struct inode *inode,
409 struct page *locked_page,
410 u64 start, u64 end,
411 struct async_cow *async_cow,
412 int *num_added)
413 {
414 struct btrfs_root *root = BTRFS_I(inode)->root;
415 u64 num_bytes;
416 u64 blocksize = root->sectorsize;
417 u64 actual_end;
418 u64 isize = i_size_read(inode);
419 int ret = 0;
420 struct page **pages = NULL;
421 unsigned long nr_pages;
422 unsigned long nr_pages_ret = 0;
423 unsigned long total_compressed = 0;
424 unsigned long total_in = 0;
425 unsigned long max_compressed = SZ_128K;
426 unsigned long max_uncompressed = SZ_128K;
427 int i;
428 int will_compress;
429 int compress_type = root->fs_info->compress_type;
430 int redirty = 0;
431
432 /* if this is a small write inside eof, kick off a defrag */
433 if ((end - start + 1) < SZ_16K &&
434 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
435 btrfs_add_inode_defrag(NULL, inode);
436
437 actual_end = min_t(u64, isize, end + 1);
438 again:
439 will_compress = 0;
440 nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
441 nr_pages = min_t(unsigned long, nr_pages, SZ_128K / PAGE_SIZE);
442
443 /*
444 * we don't want to send crud past the end of i_size through
445 * compression, that's just a waste of CPU time. So, if the
446 * end of the file is before the start of our current
447 * requested range of bytes, we bail out to the uncompressed
448 * cleanup code that can deal with all of this.
449 *
450 * It isn't really the fastest way to fix things, but this is a
451 * very uncommon corner.
452 */
453 if (actual_end <= start)
454 goto cleanup_and_bail_uncompressed;
455
456 total_compressed = actual_end - start;
457
458 /*
459 * skip compression for a small file range(<=blocksize) that
460 * isn't an inline extent, since it doesn't save disk space at all.
461 */
462 if (total_compressed <= blocksize &&
463 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
464 goto cleanup_and_bail_uncompressed;
465
466 /* we want to make sure that amount of ram required to uncompress
467 * an extent is reasonable, so we limit the total size in ram
468 * of a compressed extent to 128k. This is a crucial number
469 * because it also controls how easily we can spread reads across
470 * cpus for decompression.
471 *
472 * We also want to make sure the amount of IO required to do
473 * a random read is reasonably small, so we limit the size of
474 * a compressed extent to 128k.
475 */
476 total_compressed = min(total_compressed, max_uncompressed);
477 num_bytes = ALIGN(end - start + 1, blocksize);
478 num_bytes = max(blocksize, num_bytes);
479 total_in = 0;
480 ret = 0;
481
482 /*
483 * we do compression for mount -o compress and when the
484 * inode has not been flagged as nocompress. This flag can
485 * change at any time if we discover bad compression ratios.
486 */
487 if (inode_need_compress(inode)) {
488 WARN_ON(pages);
489 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
490 if (!pages) {
491 /* just bail out to the uncompressed code */
492 goto cont;
493 }
494
495 if (BTRFS_I(inode)->force_compress)
496 compress_type = BTRFS_I(inode)->force_compress;
497
498 /*
499 * we need to call clear_page_dirty_for_io on each
500 * page in the range. Otherwise applications with the file
501 * mmap'd can wander in and change the page contents while
502 * we are compressing them.
503 *
504 * If the compression fails for any reason, we set the pages
505 * dirty again later on.
506 */
507 extent_range_clear_dirty_for_io(inode, start, end);
508 redirty = 1;
509 ret = btrfs_compress_pages(compress_type,
510 inode->i_mapping, start,
511 total_compressed, pages,
512 nr_pages, &nr_pages_ret,
513 &total_in,
514 &total_compressed,
515 max_compressed);
516
517 if (!ret) {
518 unsigned long offset = total_compressed &
519 (PAGE_SIZE - 1);
520 struct page *page = pages[nr_pages_ret - 1];
521 char *kaddr;
522
523 /* zero the tail end of the last page, we might be
524 * sending it down to disk
525 */
526 if (offset) {
527 kaddr = kmap_atomic(page);
528 memset(kaddr + offset, 0,
529 PAGE_SIZE - offset);
530 kunmap_atomic(kaddr);
531 }
532 will_compress = 1;
533 }
534 }
535 cont:
536 if (start == 0) {
537 /* lets try to make an inline extent */
538 if (ret || total_in < (actual_end - start)) {
539 /* we didn't compress the entire range, try
540 * to make an uncompressed inline extent.
541 */
542 ret = cow_file_range_inline(root, inode, start, end,
543 0, 0, NULL);
544 } else {
545 /* try making a compressed inline extent */
546 ret = cow_file_range_inline(root, inode, start, end,
547 total_compressed,
548 compress_type, pages);
549 }
550 if (ret <= 0) {
551 unsigned long clear_flags = EXTENT_DELALLOC |
552 EXTENT_DEFRAG;
553 unsigned long page_error_op;
554
555 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0;
556 page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
557
558 /*
559 * inline extent creation worked or returned error,
560 * we don't need to create any more async work items.
561 * Unlock and free up our temp pages.
562 */
563 extent_clear_unlock_delalloc(inode, start, end, end,
564 NULL, clear_flags,
565 PAGE_UNLOCK |
566 PAGE_CLEAR_DIRTY |
567 PAGE_SET_WRITEBACK |
568 page_error_op |
569 PAGE_END_WRITEBACK);
570 btrfs_free_reserved_data_space_noquota(inode, start,
571 end - start + 1);
572 goto free_pages_out;
573 }
574 }
575
576 if (will_compress) {
577 /*
578 * we aren't doing an inline extent round the compressed size
579 * up to a block size boundary so the allocator does sane
580 * things
581 */
582 total_compressed = ALIGN(total_compressed, blocksize);
583
584 /*
585 * one last check to make sure the compression is really a
586 * win, compare the page count read with the blocks on disk
587 */
588 total_in = ALIGN(total_in, PAGE_SIZE);
589 if (total_compressed >= total_in) {
590 will_compress = 0;
591 } else {
592 num_bytes = total_in;
593 *num_added += 1;
594
595 /*
596 * The async work queues will take care of doing actual
597 * allocation on disk for these compressed pages, and
598 * will submit them to the elevator.
599 */
600 add_async_extent(async_cow, start, num_bytes,
601 total_compressed, pages, nr_pages_ret,
602 compress_type);
603
604 if (start + num_bytes < end) {
605 start += num_bytes;
606 pages = NULL;
607 cond_resched();
608 goto again;
609 }
610 return;
611 }
612 }
613 if (pages) {
614 /*
615 * the compression code ran but failed to make things smaller,
616 * free any pages it allocated and our page pointer array
617 */
618 for (i = 0; i < nr_pages_ret; i++) {
619 WARN_ON(pages[i]->mapping);
620 put_page(pages[i]);
621 }
622 kfree(pages);
623 pages = NULL;
624 total_compressed = 0;
625 nr_pages_ret = 0;
626
627 /* flag the file so we don't compress in the future */
628 if (!btrfs_test_opt(root->fs_info, FORCE_COMPRESS) &&
629 !(BTRFS_I(inode)->force_compress)) {
630 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
631 }
632 }
633 cleanup_and_bail_uncompressed:
634 /*
635 * No compression, but we still need to write the pages in the file
636 * we've been given so far. redirty the locked page if it corresponds
637 * to our extent and set things up for the async work queue to run
638 * cow_file_range to do the normal delalloc dance.
639 */
640 if (page_offset(locked_page) >= start &&
641 page_offset(locked_page) <= end)
642 __set_page_dirty_nobuffers(locked_page);
643 /* unlocked later on in the async handlers */
644
645 if (redirty)
646 extent_range_redirty_for_io(inode, start, end);
647 add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0,
648 BTRFS_COMPRESS_NONE);
649 *num_added += 1;
650
651 return;
652
653 free_pages_out:
654 for (i = 0; i < nr_pages_ret; i++) {
655 WARN_ON(pages[i]->mapping);
656 put_page(pages[i]);
657 }
658 kfree(pages);
659 }
660
661 static void free_async_extent_pages(struct async_extent *async_extent)
662 {
663 int i;
664
665 if (!async_extent->pages)
666 return;
667
668 for (i = 0; i < async_extent->nr_pages; i++) {
669 WARN_ON(async_extent->pages[i]->mapping);
670 put_page(async_extent->pages[i]);
671 }
672 kfree(async_extent->pages);
673 async_extent->nr_pages = 0;
674 async_extent->pages = NULL;
675 }
676
677 /*
678 * phase two of compressed writeback. This is the ordered portion
679 * of the code, which only gets called in the order the work was
680 * queued. We walk all the async extents created by compress_file_range
681 * and send them down to the disk.
682 */
683 static noinline void submit_compressed_extents(struct inode *inode,
684 struct async_cow *async_cow)
685 {
686 struct async_extent *async_extent;
687 u64 alloc_hint = 0;
688 struct btrfs_key ins;
689 struct extent_map *em;
690 struct btrfs_root *root = BTRFS_I(inode)->root;
691 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
692 struct extent_io_tree *io_tree;
693 int ret = 0;
694
695 again:
696 while (!list_empty(&async_cow->extents)) {
697 async_extent = list_entry(async_cow->extents.next,
698 struct async_extent, list);
699 list_del(&async_extent->list);
700
701 io_tree = &BTRFS_I(inode)->io_tree;
702
703 retry:
704 /* did the compression code fall back to uncompressed IO? */
705 if (!async_extent->pages) {
706 int page_started = 0;
707 unsigned long nr_written = 0;
708
709 lock_extent(io_tree, async_extent->start,
710 async_extent->start +
711 async_extent->ram_size - 1);
712
713 /* allocate blocks */
714 ret = cow_file_range(inode, async_cow->locked_page,
715 async_extent->start,
716 async_extent->start +
717 async_extent->ram_size - 1,
718 async_extent->start +
719 async_extent->ram_size - 1,
720 &page_started, &nr_written, 0,
721 NULL);
722
723 /* JDM XXX */
724
725 /*
726 * if page_started, cow_file_range inserted an
727 * inline extent and took care of all the unlocking
728 * and IO for us. Otherwise, we need to submit
729 * all those pages down to the drive.
730 */
731 if (!page_started && !ret)
732 extent_write_locked_range(io_tree,
733 inode, async_extent->start,
734 async_extent->start +
735 async_extent->ram_size - 1,
736 btrfs_get_extent,
737 WB_SYNC_ALL);
738 else if (ret)
739 unlock_page(async_cow->locked_page);
740 kfree(async_extent);
741 cond_resched();
742 continue;
743 }
744
745 lock_extent(io_tree, async_extent->start,
746 async_extent->start + async_extent->ram_size - 1);
747
748 ret = btrfs_reserve_extent(root, async_extent->ram_size,
749 async_extent->compressed_size,
750 async_extent->compressed_size,
751 0, alloc_hint, &ins, 1, 1);
752 if (ret) {
753 free_async_extent_pages(async_extent);
754
755 if (ret == -ENOSPC) {
756 unlock_extent(io_tree, async_extent->start,
757 async_extent->start +
758 async_extent->ram_size - 1);
759
760 /*
761 * we need to redirty the pages if we decide to
762 * fallback to uncompressed IO, otherwise we
763 * will not submit these pages down to lower
764 * layers.
765 */
766 extent_range_redirty_for_io(inode,
767 async_extent->start,
768 async_extent->start +
769 async_extent->ram_size - 1);
770
771 goto retry;
772 }
773 goto out_free;
774 }
775 /*
776 * here we're doing allocation and writeback of the
777 * compressed pages
778 */
779 btrfs_drop_extent_cache(inode, async_extent->start,
780 async_extent->start +
781 async_extent->ram_size - 1, 0);
782
783 em = alloc_extent_map();
784 if (!em) {
785 ret = -ENOMEM;
786 goto out_free_reserve;
787 }
788 em->start = async_extent->start;
789 em->len = async_extent->ram_size;
790 em->orig_start = em->start;
791 em->mod_start = em->start;
792 em->mod_len = em->len;
793
794 em->block_start = ins.objectid;
795 em->block_len = ins.offset;
796 em->orig_block_len = ins.offset;
797 em->ram_bytes = async_extent->ram_size;
798 em->bdev = root->fs_info->fs_devices->latest_bdev;
799 em->compress_type = async_extent->compress_type;
800 set_bit(EXTENT_FLAG_PINNED, &em->flags);
801 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
802 em->generation = -1;
803
804 while (1) {
805 write_lock(&em_tree->lock);
806 ret = add_extent_mapping(em_tree, em, 1);
807 write_unlock(&em_tree->lock);
808 if (ret != -EEXIST) {
809 free_extent_map(em);
810 break;
811 }
812 btrfs_drop_extent_cache(inode, async_extent->start,
813 async_extent->start +
814 async_extent->ram_size - 1, 0);
815 }
816
817 if (ret)
818 goto out_free_reserve;
819
820 ret = btrfs_add_ordered_extent_compress(inode,
821 async_extent->start,
822 ins.objectid,
823 async_extent->ram_size,
824 ins.offset,
825 BTRFS_ORDERED_COMPRESSED,
826 async_extent->compress_type);
827 if (ret) {
828 btrfs_drop_extent_cache(inode, async_extent->start,
829 async_extent->start +
830 async_extent->ram_size - 1, 0);
831 goto out_free_reserve;
832 }
833 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
834
835 /*
836 * clear dirty, set writeback and unlock the pages.
837 */
838 extent_clear_unlock_delalloc(inode, async_extent->start,
839 async_extent->start +
840 async_extent->ram_size - 1,
841 async_extent->start +
842 async_extent->ram_size - 1,
843 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
844 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
845 PAGE_SET_WRITEBACK);
846 ret = btrfs_submit_compressed_write(inode,
847 async_extent->start,
848 async_extent->ram_size,
849 ins.objectid,
850 ins.offset, async_extent->pages,
851 async_extent->nr_pages);
852 if (ret) {
853 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
854 struct page *p = async_extent->pages[0];
855 const u64 start = async_extent->start;
856 const u64 end = start + async_extent->ram_size - 1;
857
858 p->mapping = inode->i_mapping;
859 tree->ops->writepage_end_io_hook(p, start, end,
860 NULL, 0);
861 p->mapping = NULL;
862 extent_clear_unlock_delalloc(inode, start, end, end,
863 NULL, 0,
864 PAGE_END_WRITEBACK |
865 PAGE_SET_ERROR);
866 free_async_extent_pages(async_extent);
867 }
868 alloc_hint = ins.objectid + ins.offset;
869 kfree(async_extent);
870 cond_resched();
871 }
872 return;
873 out_free_reserve:
874 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
875 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
876 out_free:
877 extent_clear_unlock_delalloc(inode, async_extent->start,
878 async_extent->start +
879 async_extent->ram_size - 1,
880 async_extent->start +
881 async_extent->ram_size - 1,
882 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
883 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
884 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
885 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
886 PAGE_SET_ERROR);
887 free_async_extent_pages(async_extent);
888 kfree(async_extent);
889 goto again;
890 }
891
892 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
893 u64 num_bytes)
894 {
895 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
896 struct extent_map *em;
897 u64 alloc_hint = 0;
898
899 read_lock(&em_tree->lock);
900 em = search_extent_mapping(em_tree, start, num_bytes);
901 if (em) {
902 /*
903 * if block start isn't an actual block number then find the
904 * first block in this inode and use that as a hint. If that
905 * block is also bogus then just don't worry about it.
906 */
907 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
908 free_extent_map(em);
909 em = search_extent_mapping(em_tree, 0, 0);
910 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
911 alloc_hint = em->block_start;
912 if (em)
913 free_extent_map(em);
914 } else {
915 alloc_hint = em->block_start;
916 free_extent_map(em);
917 }
918 }
919 read_unlock(&em_tree->lock);
920
921 return alloc_hint;
922 }
923
924 /*
925 * when extent_io.c finds a delayed allocation range in the file,
926 * the call backs end up in this code. The basic idea is to
927 * allocate extents on disk for the range, and create ordered data structs
928 * in ram to track those extents.
929 *
930 * locked_page is the page that writepage had locked already. We use
931 * it to make sure we don't do extra locks or unlocks.
932 *
933 * *page_started is set to one if we unlock locked_page and do everything
934 * required to start IO on it. It may be clean and already done with
935 * IO when we return.
936 */
937 static noinline int cow_file_range(struct inode *inode,
938 struct page *locked_page,
939 u64 start, u64 end, u64 delalloc_end,
940 int *page_started, unsigned long *nr_written,
941 int unlock, struct btrfs_dedupe_hash *hash)
942 {
943 struct btrfs_root *root = BTRFS_I(inode)->root;
944 u64 alloc_hint = 0;
945 u64 num_bytes;
946 unsigned long ram_size;
947 u64 disk_num_bytes;
948 u64 cur_alloc_size;
949 u64 blocksize = root->sectorsize;
950 struct btrfs_key ins;
951 struct extent_map *em;
952 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
953 int ret = 0;
954
955 if (btrfs_is_free_space_inode(inode)) {
956 WARN_ON_ONCE(1);
957 ret = -EINVAL;
958 goto out_unlock;
959 }
960
961 num_bytes = ALIGN(end - start + 1, blocksize);
962 num_bytes = max(blocksize, num_bytes);
963 disk_num_bytes = num_bytes;
964
965 /* if this is a small write inside eof, kick off defrag */
966 if (num_bytes < SZ_64K &&
967 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
968 btrfs_add_inode_defrag(NULL, inode);
969
970 if (start == 0) {
971 /* lets try to make an inline extent */
972 ret = cow_file_range_inline(root, inode, start, end, 0, 0,
973 NULL);
974 if (ret == 0) {
975 extent_clear_unlock_delalloc(inode, start, end,
976 delalloc_end, NULL,
977 EXTENT_LOCKED | EXTENT_DELALLOC |
978 EXTENT_DEFRAG, PAGE_UNLOCK |
979 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
980 PAGE_END_WRITEBACK);
981 btrfs_free_reserved_data_space_noquota(inode, start,
982 end - start + 1);
983 *nr_written = *nr_written +
984 (end - start + PAGE_SIZE) / PAGE_SIZE;
985 *page_started = 1;
986 goto out;
987 } else if (ret < 0) {
988 goto out_unlock;
989 }
990 }
991
992 BUG_ON(disk_num_bytes >
993 btrfs_super_total_bytes(root->fs_info->super_copy));
994
995 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
996 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
997
998 while (disk_num_bytes > 0) {
999 unsigned long op;
1000
1001 cur_alloc_size = disk_num_bytes;
1002 ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size,
1003 root->sectorsize, 0, alloc_hint,
1004 &ins, 1, 1);
1005 if (ret < 0)
1006 goto out_unlock;
1007
1008 em = alloc_extent_map();
1009 if (!em) {
1010 ret = -ENOMEM;
1011 goto out_reserve;
1012 }
1013 em->start = start;
1014 em->orig_start = em->start;
1015 ram_size = ins.offset;
1016 em->len = ins.offset;
1017 em->mod_start = em->start;
1018 em->mod_len = em->len;
1019
1020 em->block_start = ins.objectid;
1021 em->block_len = ins.offset;
1022 em->orig_block_len = ins.offset;
1023 em->ram_bytes = ram_size;
1024 em->bdev = root->fs_info->fs_devices->latest_bdev;
1025 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1026 em->generation = -1;
1027
1028 while (1) {
1029 write_lock(&em_tree->lock);
1030 ret = add_extent_mapping(em_tree, em, 1);
1031 write_unlock(&em_tree->lock);
1032 if (ret != -EEXIST) {
1033 free_extent_map(em);
1034 break;
1035 }
1036 btrfs_drop_extent_cache(inode, start,
1037 start + ram_size - 1, 0);
1038 }
1039 if (ret)
1040 goto out_reserve;
1041
1042 cur_alloc_size = ins.offset;
1043 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
1044 ram_size, cur_alloc_size, 0);
1045 if (ret)
1046 goto out_drop_extent_cache;
1047
1048 if (root->root_key.objectid ==
1049 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1050 ret = btrfs_reloc_clone_csums(inode, start,
1051 cur_alloc_size);
1052 if (ret)
1053 goto out_drop_extent_cache;
1054 }
1055
1056 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
1057
1058 if (disk_num_bytes < cur_alloc_size)
1059 break;
1060
1061 /* we're not doing compressed IO, don't unlock the first
1062 * page (which the caller expects to stay locked), don't
1063 * clear any dirty bits and don't set any writeback bits
1064 *
1065 * Do set the Private2 bit so we know this page was properly
1066 * setup for writepage
1067 */
1068 op = unlock ? PAGE_UNLOCK : 0;
1069 op |= PAGE_SET_PRIVATE2;
1070
1071 extent_clear_unlock_delalloc(inode, start,
1072 start + ram_size - 1,
1073 delalloc_end, locked_page,
1074 EXTENT_LOCKED | EXTENT_DELALLOC,
1075 op);
1076 disk_num_bytes -= cur_alloc_size;
1077 num_bytes -= cur_alloc_size;
1078 alloc_hint = ins.objectid + ins.offset;
1079 start += cur_alloc_size;
1080 }
1081 out:
1082 return ret;
1083
1084 out_drop_extent_cache:
1085 btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0);
1086 out_reserve:
1087 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
1088 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
1089 out_unlock:
1090 extent_clear_unlock_delalloc(inode, start, end, delalloc_end,
1091 locked_page,
1092 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
1093 EXTENT_DELALLOC | EXTENT_DEFRAG,
1094 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
1095 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
1096 goto out;
1097 }
1098
1099 /*
1100 * work queue call back to started compression on a file and pages
1101 */
1102 static noinline void async_cow_start(struct btrfs_work *work)
1103 {
1104 struct async_cow *async_cow;
1105 int num_added = 0;
1106 async_cow = container_of(work, struct async_cow, work);
1107
1108 compress_file_range(async_cow->inode, async_cow->locked_page,
1109 async_cow->start, async_cow->end, async_cow,
1110 &num_added);
1111 if (num_added == 0) {
1112 btrfs_add_delayed_iput(async_cow->inode);
1113 async_cow->inode = NULL;
1114 }
1115 }
1116
1117 /*
1118 * work queue call back to submit previously compressed pages
1119 */
1120 static noinline void async_cow_submit(struct btrfs_work *work)
1121 {
1122 struct async_cow *async_cow;
1123 struct btrfs_root *root;
1124 unsigned long nr_pages;
1125
1126 async_cow = container_of(work, struct async_cow, work);
1127
1128 root = async_cow->root;
1129 nr_pages = (async_cow->end - async_cow->start + PAGE_SIZE) >>
1130 PAGE_SHIFT;
1131
1132 /*
1133 * atomic_sub_return implies a barrier for waitqueue_active
1134 */
1135 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1136 5 * SZ_1M &&
1137 waitqueue_active(&root->fs_info->async_submit_wait))
1138 wake_up(&root->fs_info->async_submit_wait);
1139
1140 if (async_cow->inode)
1141 submit_compressed_extents(async_cow->inode, async_cow);
1142 }
1143
1144 static noinline void async_cow_free(struct btrfs_work *work)
1145 {
1146 struct async_cow *async_cow;
1147 async_cow = container_of(work, struct async_cow, work);
1148 if (async_cow->inode)
1149 btrfs_add_delayed_iput(async_cow->inode);
1150 kfree(async_cow);
1151 }
1152
1153 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1154 u64 start, u64 end, int *page_started,
1155 unsigned long *nr_written)
1156 {
1157 struct async_cow *async_cow;
1158 struct btrfs_root *root = BTRFS_I(inode)->root;
1159 unsigned long nr_pages;
1160 u64 cur_end;
1161 int limit = 10 * SZ_1M;
1162
1163 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1164 1, 0, NULL, GFP_NOFS);
1165 while (start < end) {
1166 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1167 BUG_ON(!async_cow); /* -ENOMEM */
1168 async_cow->inode = igrab(inode);
1169 async_cow->root = root;
1170 async_cow->locked_page = locked_page;
1171 async_cow->start = start;
1172
1173 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
1174 !btrfs_test_opt(root->fs_info, FORCE_COMPRESS))
1175 cur_end = end;
1176 else
1177 cur_end = min(end, start + SZ_512K - 1);
1178
1179 async_cow->end = cur_end;
1180 INIT_LIST_HEAD(&async_cow->extents);
1181
1182 btrfs_init_work(&async_cow->work,
1183 btrfs_delalloc_helper,
1184 async_cow_start, async_cow_submit,
1185 async_cow_free);
1186
1187 nr_pages = (cur_end - start + PAGE_SIZE) >>
1188 PAGE_SHIFT;
1189 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1190
1191 btrfs_queue_work(root->fs_info->delalloc_workers,
1192 &async_cow->work);
1193
1194 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1195 wait_event(root->fs_info->async_submit_wait,
1196 (atomic_read(&root->fs_info->async_delalloc_pages) <
1197 limit));
1198 }
1199
1200 while (atomic_read(&root->fs_info->async_submit_draining) &&
1201 atomic_read(&root->fs_info->async_delalloc_pages)) {
1202 wait_event(root->fs_info->async_submit_wait,
1203 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1204 0));
1205 }
1206
1207 *nr_written += nr_pages;
1208 start = cur_end + 1;
1209 }
1210 *page_started = 1;
1211 return 0;
1212 }
1213
1214 static noinline int csum_exist_in_range(struct btrfs_root *root,
1215 u64 bytenr, u64 num_bytes)
1216 {
1217 int ret;
1218 struct btrfs_ordered_sum *sums;
1219 LIST_HEAD(list);
1220
1221 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1222 bytenr + num_bytes - 1, &list, 0);
1223 if (ret == 0 && list_empty(&list))
1224 return 0;
1225
1226 while (!list_empty(&list)) {
1227 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1228 list_del(&sums->list);
1229 kfree(sums);
1230 }
1231 return 1;
1232 }
1233
1234 /*
1235 * when nowcow writeback call back. This checks for snapshots or COW copies
1236 * of the extents that exist in the file, and COWs the file as required.
1237 *
1238 * If no cow copies or snapshots exist, we write directly to the existing
1239 * blocks on disk
1240 */
1241 static noinline int run_delalloc_nocow(struct inode *inode,
1242 struct page *locked_page,
1243 u64 start, u64 end, int *page_started, int force,
1244 unsigned long *nr_written)
1245 {
1246 struct btrfs_root *root = BTRFS_I(inode)->root;
1247 struct btrfs_trans_handle *trans;
1248 struct extent_buffer *leaf;
1249 struct btrfs_path *path;
1250 struct btrfs_file_extent_item *fi;
1251 struct btrfs_key found_key;
1252 u64 cow_start;
1253 u64 cur_offset;
1254 u64 extent_end;
1255 u64 extent_offset;
1256 u64 disk_bytenr;
1257 u64 num_bytes;
1258 u64 disk_num_bytes;
1259 u64 ram_bytes;
1260 int extent_type;
1261 int ret, err;
1262 int type;
1263 int nocow;
1264 int check_prev = 1;
1265 bool nolock;
1266 u64 ino = btrfs_ino(inode);
1267
1268 path = btrfs_alloc_path();
1269 if (!path) {
1270 extent_clear_unlock_delalloc(inode, start, end, end,
1271 locked_page,
1272 EXTENT_LOCKED | EXTENT_DELALLOC |
1273 EXTENT_DO_ACCOUNTING |
1274 EXTENT_DEFRAG, PAGE_UNLOCK |
1275 PAGE_CLEAR_DIRTY |
1276 PAGE_SET_WRITEBACK |
1277 PAGE_END_WRITEBACK);
1278 return -ENOMEM;
1279 }
1280
1281 nolock = btrfs_is_free_space_inode(inode);
1282
1283 if (nolock)
1284 trans = btrfs_join_transaction_nolock(root);
1285 else
1286 trans = btrfs_join_transaction(root);
1287
1288 if (IS_ERR(trans)) {
1289 extent_clear_unlock_delalloc(inode, start, end, end,
1290 locked_page,
1291 EXTENT_LOCKED | EXTENT_DELALLOC |
1292 EXTENT_DO_ACCOUNTING |
1293 EXTENT_DEFRAG, PAGE_UNLOCK |
1294 PAGE_CLEAR_DIRTY |
1295 PAGE_SET_WRITEBACK |
1296 PAGE_END_WRITEBACK);
1297 btrfs_free_path(path);
1298 return PTR_ERR(trans);
1299 }
1300
1301 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1302
1303 cow_start = (u64)-1;
1304 cur_offset = start;
1305 while (1) {
1306 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1307 cur_offset, 0);
1308 if (ret < 0)
1309 goto error;
1310 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1311 leaf = path->nodes[0];
1312 btrfs_item_key_to_cpu(leaf, &found_key,
1313 path->slots[0] - 1);
1314 if (found_key.objectid == ino &&
1315 found_key.type == BTRFS_EXTENT_DATA_KEY)
1316 path->slots[0]--;
1317 }
1318 check_prev = 0;
1319 next_slot:
1320 leaf = path->nodes[0];
1321 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1322 ret = btrfs_next_leaf(root, path);
1323 if (ret < 0)
1324 goto error;
1325 if (ret > 0)
1326 break;
1327 leaf = path->nodes[0];
1328 }
1329
1330 nocow = 0;
1331 disk_bytenr = 0;
1332 num_bytes = 0;
1333 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1334
1335 if (found_key.objectid > ino)
1336 break;
1337 if (WARN_ON_ONCE(found_key.objectid < ino) ||
1338 found_key.type < BTRFS_EXTENT_DATA_KEY) {
1339 path->slots[0]++;
1340 goto next_slot;
1341 }
1342 if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
1343 found_key.offset > end)
1344 break;
1345
1346 if (found_key.offset > cur_offset) {
1347 extent_end = found_key.offset;
1348 extent_type = 0;
1349 goto out_check;
1350 }
1351
1352 fi = btrfs_item_ptr(leaf, path->slots[0],
1353 struct btrfs_file_extent_item);
1354 extent_type = btrfs_file_extent_type(leaf, fi);
1355
1356 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1357 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1358 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1359 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1360 extent_offset = btrfs_file_extent_offset(leaf, fi);
1361 extent_end = found_key.offset +
1362 btrfs_file_extent_num_bytes(leaf, fi);
1363 disk_num_bytes =
1364 btrfs_file_extent_disk_num_bytes(leaf, fi);
1365 if (extent_end <= start) {
1366 path->slots[0]++;
1367 goto next_slot;
1368 }
1369 if (disk_bytenr == 0)
1370 goto out_check;
1371 if (btrfs_file_extent_compression(leaf, fi) ||
1372 btrfs_file_extent_encryption(leaf, fi) ||
1373 btrfs_file_extent_other_encoding(leaf, fi))
1374 goto out_check;
1375 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1376 goto out_check;
1377 if (btrfs_extent_readonly(root, disk_bytenr))
1378 goto out_check;
1379 if (btrfs_cross_ref_exist(trans, root, ino,
1380 found_key.offset -
1381 extent_offset, disk_bytenr))
1382 goto out_check;
1383 disk_bytenr += extent_offset;
1384 disk_bytenr += cur_offset - found_key.offset;
1385 num_bytes = min(end + 1, extent_end) - cur_offset;
1386 /*
1387 * if there are pending snapshots for this root,
1388 * we fall into common COW way.
1389 */
1390 if (!nolock) {
1391 err = btrfs_start_write_no_snapshoting(root);
1392 if (!err)
1393 goto out_check;
1394 }
1395 /*
1396 * force cow if csum exists in the range.
1397 * this ensure that csum for a given extent are
1398 * either valid or do not exist.
1399 */
1400 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1401 goto out_check;
1402 if (!btrfs_inc_nocow_writers(root->fs_info,
1403 disk_bytenr))
1404 goto out_check;
1405 nocow = 1;
1406 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1407 extent_end = found_key.offset +
1408 btrfs_file_extent_inline_len(leaf,
1409 path->slots[0], fi);
1410 extent_end = ALIGN(extent_end, root->sectorsize);
1411 } else {
1412 BUG_ON(1);
1413 }
1414 out_check:
1415 if (extent_end <= start) {
1416 path->slots[0]++;
1417 if (!nolock && nocow)
1418 btrfs_end_write_no_snapshoting(root);
1419 if (nocow)
1420 btrfs_dec_nocow_writers(root->fs_info,
1421 disk_bytenr);
1422 goto next_slot;
1423 }
1424 if (!nocow) {
1425 if (cow_start == (u64)-1)
1426 cow_start = cur_offset;
1427 cur_offset = extent_end;
1428 if (cur_offset > end)
1429 break;
1430 path->slots[0]++;
1431 goto next_slot;
1432 }
1433
1434 btrfs_release_path(path);
1435 if (cow_start != (u64)-1) {
1436 ret = cow_file_range(inode, locked_page,
1437 cow_start, found_key.offset - 1,
1438 end, page_started, nr_written, 1,
1439 NULL);
1440 if (ret) {
1441 if (!nolock && nocow)
1442 btrfs_end_write_no_snapshoting(root);
1443 if (nocow)
1444 btrfs_dec_nocow_writers(root->fs_info,
1445 disk_bytenr);
1446 goto error;
1447 }
1448 cow_start = (u64)-1;
1449 }
1450
1451 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1452 struct extent_map *em;
1453 struct extent_map_tree *em_tree;
1454 em_tree = &BTRFS_I(inode)->extent_tree;
1455 em = alloc_extent_map();
1456 BUG_ON(!em); /* -ENOMEM */
1457 em->start = cur_offset;
1458 em->orig_start = found_key.offset - extent_offset;
1459 em->len = num_bytes;
1460 em->block_len = num_bytes;
1461 em->block_start = disk_bytenr;
1462 em->orig_block_len = disk_num_bytes;
1463 em->ram_bytes = ram_bytes;
1464 em->bdev = root->fs_info->fs_devices->latest_bdev;
1465 em->mod_start = em->start;
1466 em->mod_len = em->len;
1467 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1468 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1469 em->generation = -1;
1470 while (1) {
1471 write_lock(&em_tree->lock);
1472 ret = add_extent_mapping(em_tree, em, 1);
1473 write_unlock(&em_tree->lock);
1474 if (ret != -EEXIST) {
1475 free_extent_map(em);
1476 break;
1477 }
1478 btrfs_drop_extent_cache(inode, em->start,
1479 em->start + em->len - 1, 0);
1480 }
1481 type = BTRFS_ORDERED_PREALLOC;
1482 } else {
1483 type = BTRFS_ORDERED_NOCOW;
1484 }
1485
1486 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1487 num_bytes, num_bytes, type);
1488 if (nocow)
1489 btrfs_dec_nocow_writers(root->fs_info, disk_bytenr);
1490 BUG_ON(ret); /* -ENOMEM */
1491
1492 if (root->root_key.objectid ==
1493 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1494 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1495 num_bytes);
1496 if (ret) {
1497 if (!nolock && nocow)
1498 btrfs_end_write_no_snapshoting(root);
1499 goto error;
1500 }
1501 }
1502
1503 extent_clear_unlock_delalloc(inode, cur_offset,
1504 cur_offset + num_bytes - 1, end,
1505 locked_page, EXTENT_LOCKED |
1506 EXTENT_DELALLOC |
1507 EXTENT_CLEAR_DATA_RESV,
1508 PAGE_UNLOCK | PAGE_SET_PRIVATE2);
1509
1510 if (!nolock && nocow)
1511 btrfs_end_write_no_snapshoting(root);
1512 cur_offset = extent_end;
1513 if (cur_offset > end)
1514 break;
1515 }
1516 btrfs_release_path(path);
1517
1518 if (cur_offset <= end && cow_start == (u64)-1) {
1519 cow_start = cur_offset;
1520 cur_offset = end;
1521 }
1522
1523 if (cow_start != (u64)-1) {
1524 ret = cow_file_range(inode, locked_page, cow_start, end, end,
1525 page_started, nr_written, 1, NULL);
1526 if (ret)
1527 goto error;
1528 }
1529
1530 error:
1531 err = btrfs_end_transaction(trans, root);
1532 if (!ret)
1533 ret = err;
1534
1535 if (ret && cur_offset < end)
1536 extent_clear_unlock_delalloc(inode, cur_offset, end, end,
1537 locked_page, EXTENT_LOCKED |
1538 EXTENT_DELALLOC | EXTENT_DEFRAG |
1539 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1540 PAGE_CLEAR_DIRTY |
1541 PAGE_SET_WRITEBACK |
1542 PAGE_END_WRITEBACK);
1543 btrfs_free_path(path);
1544 return ret;
1545 }
1546
1547 static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
1548 {
1549
1550 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
1551 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
1552 return 0;
1553
1554 /*
1555 * @defrag_bytes is a hint value, no spinlock held here,
1556 * if is not zero, it means the file is defragging.
1557 * Force cow if given extent needs to be defragged.
1558 */
1559 if (BTRFS_I(inode)->defrag_bytes &&
1560 test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1561 EXTENT_DEFRAG, 0, NULL))
1562 return 1;
1563
1564 return 0;
1565 }
1566
1567 /*
1568 * extent_io.c call back to do delayed allocation processing
1569 */
1570 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1571 u64 start, u64 end, int *page_started,
1572 unsigned long *nr_written)
1573 {
1574 int ret;
1575 int force_cow = need_force_cow(inode, start, end);
1576
1577 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
1578 ret = run_delalloc_nocow(inode, locked_page, start, end,
1579 page_started, 1, nr_written);
1580 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
1581 ret = run_delalloc_nocow(inode, locked_page, start, end,
1582 page_started, 0, nr_written);
1583 } else if (!inode_need_compress(inode)) {
1584 ret = cow_file_range(inode, locked_page, start, end, end,
1585 page_started, nr_written, 1, NULL);
1586 } else {
1587 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1588 &BTRFS_I(inode)->runtime_flags);
1589 ret = cow_file_range_async(inode, locked_page, start, end,
1590 page_started, nr_written);
1591 }
1592 return ret;
1593 }
1594
1595 static void btrfs_split_extent_hook(struct inode *inode,
1596 struct extent_state *orig, u64 split)
1597 {
1598 u64 size;
1599
1600 /* not delalloc, ignore it */
1601 if (!(orig->state & EXTENT_DELALLOC))
1602 return;
1603
1604 size = orig->end - orig->start + 1;
1605 if (size > BTRFS_MAX_EXTENT_SIZE) {
1606 u64 num_extents;
1607 u64 new_size;
1608
1609 /*
1610 * See the explanation in btrfs_merge_extent_hook, the same
1611 * applies here, just in reverse.
1612 */
1613 new_size = orig->end - split + 1;
1614 num_extents = div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1615 BTRFS_MAX_EXTENT_SIZE);
1616 new_size = split - orig->start;
1617 num_extents += div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1618 BTRFS_MAX_EXTENT_SIZE);
1619 if (div64_u64(size + BTRFS_MAX_EXTENT_SIZE - 1,
1620 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1621 return;
1622 }
1623
1624 spin_lock(&BTRFS_I(inode)->lock);
1625 BTRFS_I(inode)->outstanding_extents++;
1626 spin_unlock(&BTRFS_I(inode)->lock);
1627 }
1628
1629 /*
1630 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1631 * extents so we can keep track of new extents that are just merged onto old
1632 * extents, such as when we are doing sequential writes, so we can properly
1633 * account for the metadata space we'll need.
1634 */
1635 static void btrfs_merge_extent_hook(struct inode *inode,
1636 struct extent_state *new,
1637 struct extent_state *other)
1638 {
1639 u64 new_size, old_size;
1640 u64 num_extents;
1641
1642 /* not delalloc, ignore it */
1643 if (!(other->state & EXTENT_DELALLOC))
1644 return;
1645
1646 if (new->start > other->start)
1647 new_size = new->end - other->start + 1;
1648 else
1649 new_size = other->end - new->start + 1;
1650
1651 /* we're not bigger than the max, unreserve the space and go */
1652 if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
1653 spin_lock(&BTRFS_I(inode)->lock);
1654 BTRFS_I(inode)->outstanding_extents--;
1655 spin_unlock(&BTRFS_I(inode)->lock);
1656 return;
1657 }
1658
1659 /*
1660 * We have to add up either side to figure out how many extents were
1661 * accounted for before we merged into one big extent. If the number of
1662 * extents we accounted for is <= the amount we need for the new range
1663 * then we can return, otherwise drop. Think of it like this
1664 *
1665 * [ 4k][MAX_SIZE]
1666 *
1667 * So we've grown the extent by a MAX_SIZE extent, this would mean we
1668 * need 2 outstanding extents, on one side we have 1 and the other side
1669 * we have 1 so they are == and we can return. But in this case
1670 *
1671 * [MAX_SIZE+4k][MAX_SIZE+4k]
1672 *
1673 * Each range on their own accounts for 2 extents, but merged together
1674 * they are only 3 extents worth of accounting, so we need to drop in
1675 * this case.
1676 */
1677 old_size = other->end - other->start + 1;
1678 num_extents = div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1679 BTRFS_MAX_EXTENT_SIZE);
1680 old_size = new->end - new->start + 1;
1681 num_extents += div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1682 BTRFS_MAX_EXTENT_SIZE);
1683
1684 if (div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1685 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1686 return;
1687
1688 spin_lock(&BTRFS_I(inode)->lock);
1689 BTRFS_I(inode)->outstanding_extents--;
1690 spin_unlock(&BTRFS_I(inode)->lock);
1691 }
1692
1693 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1694 struct inode *inode)
1695 {
1696 spin_lock(&root->delalloc_lock);
1697 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1698 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1699 &root->delalloc_inodes);
1700 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1701 &BTRFS_I(inode)->runtime_flags);
1702 root->nr_delalloc_inodes++;
1703 if (root->nr_delalloc_inodes == 1) {
1704 spin_lock(&root->fs_info->delalloc_root_lock);
1705 BUG_ON(!list_empty(&root->delalloc_root));
1706 list_add_tail(&root->delalloc_root,
1707 &root->fs_info->delalloc_roots);
1708 spin_unlock(&root->fs_info->delalloc_root_lock);
1709 }
1710 }
1711 spin_unlock(&root->delalloc_lock);
1712 }
1713
1714 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1715 struct inode *inode)
1716 {
1717 spin_lock(&root->delalloc_lock);
1718 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1719 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1720 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1721 &BTRFS_I(inode)->runtime_flags);
1722 root->nr_delalloc_inodes--;
1723 if (!root->nr_delalloc_inodes) {
1724 spin_lock(&root->fs_info->delalloc_root_lock);
1725 BUG_ON(list_empty(&root->delalloc_root));
1726 list_del_init(&root->delalloc_root);
1727 spin_unlock(&root->fs_info->delalloc_root_lock);
1728 }
1729 }
1730 spin_unlock(&root->delalloc_lock);
1731 }
1732
1733 /*
1734 * extent_io.c set_bit_hook, used to track delayed allocation
1735 * bytes in this file, and to maintain the list of inodes that
1736 * have pending delalloc work to be done.
1737 */
1738 static void btrfs_set_bit_hook(struct inode *inode,
1739 struct extent_state *state, unsigned *bits)
1740 {
1741
1742 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
1743 WARN_ON(1);
1744 /*
1745 * set_bit and clear bit hooks normally require _irqsave/restore
1746 * but in this case, we are only testing for the DELALLOC
1747 * bit, which is only set or cleared with irqs on
1748 */
1749 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1750 struct btrfs_root *root = BTRFS_I(inode)->root;
1751 u64 len = state->end + 1 - state->start;
1752 bool do_list = !btrfs_is_free_space_inode(inode);
1753
1754 if (*bits & EXTENT_FIRST_DELALLOC) {
1755 *bits &= ~EXTENT_FIRST_DELALLOC;
1756 } else {
1757 spin_lock(&BTRFS_I(inode)->lock);
1758 BTRFS_I(inode)->outstanding_extents++;
1759 spin_unlock(&BTRFS_I(inode)->lock);
1760 }
1761
1762 /* For sanity tests */
1763 if (btrfs_is_testing(root->fs_info))
1764 return;
1765
1766 __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
1767 root->fs_info->delalloc_batch);
1768 spin_lock(&BTRFS_I(inode)->lock);
1769 BTRFS_I(inode)->delalloc_bytes += len;
1770 if (*bits & EXTENT_DEFRAG)
1771 BTRFS_I(inode)->defrag_bytes += len;
1772 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1773 &BTRFS_I(inode)->runtime_flags))
1774 btrfs_add_delalloc_inodes(root, inode);
1775 spin_unlock(&BTRFS_I(inode)->lock);
1776 }
1777 }
1778
1779 /*
1780 * extent_io.c clear_bit_hook, see set_bit_hook for why
1781 */
1782 static void btrfs_clear_bit_hook(struct inode *inode,
1783 struct extent_state *state,
1784 unsigned *bits)
1785 {
1786 u64 len = state->end + 1 - state->start;
1787 u64 num_extents = div64_u64(len + BTRFS_MAX_EXTENT_SIZE -1,
1788 BTRFS_MAX_EXTENT_SIZE);
1789
1790 spin_lock(&BTRFS_I(inode)->lock);
1791 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG))
1792 BTRFS_I(inode)->defrag_bytes -= len;
1793 spin_unlock(&BTRFS_I(inode)->lock);
1794
1795 /*
1796 * set_bit and clear bit hooks normally require _irqsave/restore
1797 * but in this case, we are only testing for the DELALLOC
1798 * bit, which is only set or cleared with irqs on
1799 */
1800 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1801 struct btrfs_root *root = BTRFS_I(inode)->root;
1802 bool do_list = !btrfs_is_free_space_inode(inode);
1803
1804 if (*bits & EXTENT_FIRST_DELALLOC) {
1805 *bits &= ~EXTENT_FIRST_DELALLOC;
1806 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1807 spin_lock(&BTRFS_I(inode)->lock);
1808 BTRFS_I(inode)->outstanding_extents -= num_extents;
1809 spin_unlock(&BTRFS_I(inode)->lock);
1810 }
1811
1812 /*
1813 * We don't reserve metadata space for space cache inodes so we
1814 * don't need to call dellalloc_release_metadata if there is an
1815 * error.
1816 */
1817 if (*bits & EXTENT_DO_ACCOUNTING &&
1818 root != root->fs_info->tree_root)
1819 btrfs_delalloc_release_metadata(inode, len);
1820
1821 /* For sanity tests. */
1822 if (btrfs_is_testing(root->fs_info))
1823 return;
1824
1825 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1826 && do_list && !(state->state & EXTENT_NORESERVE)
1827 && (*bits & (EXTENT_DO_ACCOUNTING |
1828 EXTENT_CLEAR_DATA_RESV)))
1829 btrfs_free_reserved_data_space_noquota(inode,
1830 state->start, len);
1831
1832 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
1833 root->fs_info->delalloc_batch);
1834 spin_lock(&BTRFS_I(inode)->lock);
1835 BTRFS_I(inode)->delalloc_bytes -= len;
1836 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1837 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1838 &BTRFS_I(inode)->runtime_flags))
1839 btrfs_del_delalloc_inode(root, inode);
1840 spin_unlock(&BTRFS_I(inode)->lock);
1841 }
1842 }
1843
1844 /*
1845 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1846 * we don't create bios that span stripes or chunks
1847 *
1848 * return 1 if page cannot be merged to bio
1849 * return 0 if page can be merged to bio
1850 * return error otherwise
1851 */
1852 int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
1853 size_t size, struct bio *bio,
1854 unsigned long bio_flags)
1855 {
1856 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1857 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1858 u64 length = 0;
1859 u64 map_length;
1860 int ret;
1861
1862 if (bio_flags & EXTENT_BIO_COMPRESSED)
1863 return 0;
1864
1865 length = bio->bi_iter.bi_size;
1866 map_length = length;
1867 ret = btrfs_map_block(root->fs_info, bio_op(bio), logical,
1868 &map_length, NULL, 0);
1869 if (ret < 0)
1870 return ret;
1871 if (map_length < length + size)
1872 return 1;
1873 return 0;
1874 }
1875
1876 /*
1877 * in order to insert checksums into the metadata in large chunks,
1878 * we wait until bio submission time. All the pages in the bio are
1879 * checksummed and sums are attached onto the ordered extent record.
1880 *
1881 * At IO completion time the cums attached on the ordered extent record
1882 * are inserted into the btree
1883 */
1884 static int __btrfs_submit_bio_start(struct inode *inode, struct bio *bio,
1885 int mirror_num, unsigned long bio_flags,
1886 u64 bio_offset)
1887 {
1888 struct btrfs_root *root = BTRFS_I(inode)->root;
1889 int ret = 0;
1890
1891 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1892 BUG_ON(ret); /* -ENOMEM */
1893 return 0;
1894 }
1895
1896 /*
1897 * in order to insert checksums into the metadata in large chunks,
1898 * we wait until bio submission time. All the pages in the bio are
1899 * checksummed and sums are attached onto the ordered extent record.
1900 *
1901 * At IO completion time the cums attached on the ordered extent record
1902 * are inserted into the btree
1903 */
1904 static int __btrfs_submit_bio_done(struct inode *inode, struct bio *bio,
1905 int mirror_num, unsigned long bio_flags,
1906 u64 bio_offset)
1907 {
1908 struct btrfs_root *root = BTRFS_I(inode)->root;
1909 int ret;
1910
1911 ret = btrfs_map_bio(root, bio, mirror_num, 1);
1912 if (ret) {
1913 bio->bi_error = ret;
1914 bio_endio(bio);
1915 }
1916 return ret;
1917 }
1918
1919 /*
1920 * extent_io.c submission hook. This does the right thing for csum calculation
1921 * on write, or reading the csums from the tree before a read
1922 */
1923 static int btrfs_submit_bio_hook(struct inode *inode, struct bio *bio,
1924 int mirror_num, unsigned long bio_flags,
1925 u64 bio_offset)
1926 {
1927 struct btrfs_root *root = BTRFS_I(inode)->root;
1928 enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
1929 int ret = 0;
1930 int skip_sum;
1931 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1932
1933 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1934
1935 if (btrfs_is_free_space_inode(inode))
1936 metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
1937
1938 if (bio_op(bio) != REQ_OP_WRITE) {
1939 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1940 if (ret)
1941 goto out;
1942
1943 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1944 ret = btrfs_submit_compressed_read(inode, bio,
1945 mirror_num,
1946 bio_flags);
1947 goto out;
1948 } else if (!skip_sum) {
1949 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1950 if (ret)
1951 goto out;
1952 }
1953 goto mapit;
1954 } else if (async && !skip_sum) {
1955 /* csum items have already been cloned */
1956 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1957 goto mapit;
1958 /* we're doing a write, do the async checksumming */
1959 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1960 inode, bio, mirror_num,
1961 bio_flags, bio_offset,
1962 __btrfs_submit_bio_start,
1963 __btrfs_submit_bio_done);
1964 goto out;
1965 } else if (!skip_sum) {
1966 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1967 if (ret)
1968 goto out;
1969 }
1970
1971 mapit:
1972 ret = btrfs_map_bio(root, bio, mirror_num, 0);
1973
1974 out:
1975 if (ret < 0) {
1976 bio->bi_error = ret;
1977 bio_endio(bio);
1978 }
1979 return ret;
1980 }
1981
1982 /*
1983 * given a list of ordered sums record them in the inode. This happens
1984 * at IO completion time based on sums calculated at bio submission time.
1985 */
1986 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1987 struct inode *inode, u64 file_offset,
1988 struct list_head *list)
1989 {
1990 struct btrfs_ordered_sum *sum;
1991
1992 list_for_each_entry(sum, list, list) {
1993 trans->adding_csums = 1;
1994 btrfs_csum_file_blocks(trans,
1995 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1996 trans->adding_csums = 0;
1997 }
1998 return 0;
1999 }
2000
2001 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
2002 struct extent_state **cached_state, int dedupe)
2003 {
2004 WARN_ON((end & (PAGE_SIZE - 1)) == 0);
2005 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
2006 cached_state);
2007 }
2008
2009 /* see btrfs_writepage_start_hook for details on why this is required */
2010 struct btrfs_writepage_fixup {
2011 struct page *page;
2012 struct btrfs_work work;
2013 };
2014
2015 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
2016 {
2017 struct btrfs_writepage_fixup *fixup;
2018 struct btrfs_ordered_extent *ordered;
2019 struct extent_state *cached_state = NULL;
2020 struct page *page;
2021 struct inode *inode;
2022 u64 page_start;
2023 u64 page_end;
2024 int ret;
2025
2026 fixup = container_of(work, struct btrfs_writepage_fixup, work);
2027 page = fixup->page;
2028 again:
2029 lock_page(page);
2030 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
2031 ClearPageChecked(page);
2032 goto out_page;
2033 }
2034
2035 inode = page->mapping->host;
2036 page_start = page_offset(page);
2037 page_end = page_offset(page) + PAGE_SIZE - 1;
2038
2039 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
2040 &cached_state);
2041
2042 /* already ordered? We're done */
2043 if (PagePrivate2(page))
2044 goto out;
2045
2046 ordered = btrfs_lookup_ordered_range(inode, page_start,
2047 PAGE_SIZE);
2048 if (ordered) {
2049 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
2050 page_end, &cached_state, GFP_NOFS);
2051 unlock_page(page);
2052 btrfs_start_ordered_extent(inode, ordered, 1);
2053 btrfs_put_ordered_extent(ordered);
2054 goto again;
2055 }
2056
2057 ret = btrfs_delalloc_reserve_space(inode, page_start,
2058 PAGE_SIZE);
2059 if (ret) {
2060 mapping_set_error(page->mapping, ret);
2061 end_extent_writepage(page, ret, page_start, page_end);
2062 ClearPageChecked(page);
2063 goto out;
2064 }
2065
2066 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state,
2067 0);
2068 ClearPageChecked(page);
2069 set_page_dirty(page);
2070 out:
2071 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
2072 &cached_state, GFP_NOFS);
2073 out_page:
2074 unlock_page(page);
2075 put_page(page);
2076 kfree(fixup);
2077 }
2078
2079 /*
2080 * There are a few paths in the higher layers of the kernel that directly
2081 * set the page dirty bit without asking the filesystem if it is a
2082 * good idea. This causes problems because we want to make sure COW
2083 * properly happens and the data=ordered rules are followed.
2084 *
2085 * In our case any range that doesn't have the ORDERED bit set
2086 * hasn't been properly setup for IO. We kick off an async process
2087 * to fix it up. The async helper will wait for ordered extents, set
2088 * the delalloc bit and make it safe to write the page.
2089 */
2090 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
2091 {
2092 struct inode *inode = page->mapping->host;
2093 struct btrfs_writepage_fixup *fixup;
2094 struct btrfs_root *root = BTRFS_I(inode)->root;
2095
2096 /* this page is properly in the ordered list */
2097 if (TestClearPagePrivate2(page))
2098 return 0;
2099
2100 if (PageChecked(page))
2101 return -EAGAIN;
2102
2103 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
2104 if (!fixup)
2105 return -EAGAIN;
2106
2107 SetPageChecked(page);
2108 get_page(page);
2109 btrfs_init_work(&fixup->work, btrfs_fixup_helper,
2110 btrfs_writepage_fixup_worker, NULL, NULL);
2111 fixup->page = page;
2112 btrfs_queue_work(root->fs_info->fixup_workers, &fixup->work);
2113 return -EBUSY;
2114 }
2115
2116 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
2117 struct inode *inode, u64 file_pos,
2118 u64 disk_bytenr, u64 disk_num_bytes,
2119 u64 num_bytes, u64 ram_bytes,
2120 u8 compression, u8 encryption,
2121 u16 other_encoding, int extent_type)
2122 {
2123 struct btrfs_root *root = BTRFS_I(inode)->root;
2124 struct btrfs_file_extent_item *fi;
2125 struct btrfs_path *path;
2126 struct extent_buffer *leaf;
2127 struct btrfs_key ins;
2128 int extent_inserted = 0;
2129 int ret;
2130
2131 path = btrfs_alloc_path();
2132 if (!path)
2133 return -ENOMEM;
2134
2135 /*
2136 * we may be replacing one extent in the tree with another.
2137 * The new extent is pinned in the extent map, and we don't want
2138 * to drop it from the cache until it is completely in the btree.
2139 *
2140 * So, tell btrfs_drop_extents to leave this extent in the cache.
2141 * the caller is expected to unpin it and allow it to be merged
2142 * with the others.
2143 */
2144 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
2145 file_pos + num_bytes, NULL, 0,
2146 1, sizeof(*fi), &extent_inserted);
2147 if (ret)
2148 goto out;
2149
2150 if (!extent_inserted) {
2151 ins.objectid = btrfs_ino(inode);
2152 ins.offset = file_pos;
2153 ins.type = BTRFS_EXTENT_DATA_KEY;
2154
2155 path->leave_spinning = 1;
2156 ret = btrfs_insert_empty_item(trans, root, path, &ins,
2157 sizeof(*fi));
2158 if (ret)
2159 goto out;
2160 }
2161 leaf = path->nodes[0];
2162 fi = btrfs_item_ptr(leaf, path->slots[0],
2163 struct btrfs_file_extent_item);
2164 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2165 btrfs_set_file_extent_type(leaf, fi, extent_type);
2166 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
2167 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
2168 btrfs_set_file_extent_offset(leaf, fi, 0);
2169 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2170 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
2171 btrfs_set_file_extent_compression(leaf, fi, compression);
2172 btrfs_set_file_extent_encryption(leaf, fi, encryption);
2173 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
2174
2175 btrfs_mark_buffer_dirty(leaf);
2176 btrfs_release_path(path);
2177
2178 inode_add_bytes(inode, num_bytes);
2179
2180 ins.objectid = disk_bytenr;
2181 ins.offset = disk_num_bytes;
2182 ins.type = BTRFS_EXTENT_ITEM_KEY;
2183 ret = btrfs_alloc_reserved_file_extent(trans, root,
2184 root->root_key.objectid,
2185 btrfs_ino(inode), file_pos,
2186 ram_bytes, &ins);
2187 /*
2188 * Release the reserved range from inode dirty range map, as it is
2189 * already moved into delayed_ref_head
2190 */
2191 btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
2192 out:
2193 btrfs_free_path(path);
2194
2195 return ret;
2196 }
2197
2198 /* snapshot-aware defrag */
2199 struct sa_defrag_extent_backref {
2200 struct rb_node node;
2201 struct old_sa_defrag_extent *old;
2202 u64 root_id;
2203 u64 inum;
2204 u64 file_pos;
2205 u64 extent_offset;
2206 u64 num_bytes;
2207 u64 generation;
2208 };
2209
2210 struct old_sa_defrag_extent {
2211 struct list_head list;
2212 struct new_sa_defrag_extent *new;
2213
2214 u64 extent_offset;
2215 u64 bytenr;
2216 u64 offset;
2217 u64 len;
2218 int count;
2219 };
2220
2221 struct new_sa_defrag_extent {
2222 struct rb_root root;
2223 struct list_head head;
2224 struct btrfs_path *path;
2225 struct inode *inode;
2226 u64 file_pos;
2227 u64 len;
2228 u64 bytenr;
2229 u64 disk_len;
2230 u8 compress_type;
2231 };
2232
2233 static int backref_comp(struct sa_defrag_extent_backref *b1,
2234 struct sa_defrag_extent_backref *b2)
2235 {
2236 if (b1->root_id < b2->root_id)
2237 return -1;
2238 else if (b1->root_id > b2->root_id)
2239 return 1;
2240
2241 if (b1->inum < b2->inum)
2242 return -1;
2243 else if (b1->inum > b2->inum)
2244 return 1;
2245
2246 if (b1->file_pos < b2->file_pos)
2247 return -1;
2248 else if (b1->file_pos > b2->file_pos)
2249 return 1;
2250
2251 /*
2252 * [------------------------------] ===> (a range of space)
2253 * |<--->| |<---->| =============> (fs/file tree A)
2254 * |<---------------------------->| ===> (fs/file tree B)
2255 *
2256 * A range of space can refer to two file extents in one tree while
2257 * refer to only one file extent in another tree.
2258 *
2259 * So we may process a disk offset more than one time(two extents in A)
2260 * and locate at the same extent(one extent in B), then insert two same
2261 * backrefs(both refer to the extent in B).
2262 */
2263 return 0;
2264 }
2265
2266 static void backref_insert(struct rb_root *root,
2267 struct sa_defrag_extent_backref *backref)
2268 {
2269 struct rb_node **p = &root->rb_node;
2270 struct rb_node *parent = NULL;
2271 struct sa_defrag_extent_backref *entry;
2272 int ret;
2273
2274 while (*p) {
2275 parent = *p;
2276 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2277
2278 ret = backref_comp(backref, entry);
2279 if (ret < 0)
2280 p = &(*p)->rb_left;
2281 else
2282 p = &(*p)->rb_right;
2283 }
2284
2285 rb_link_node(&backref->node, parent, p);
2286 rb_insert_color(&backref->node, root);
2287 }
2288
2289 /*
2290 * Note the backref might has changed, and in this case we just return 0.
2291 */
2292 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2293 void *ctx)
2294 {
2295 struct btrfs_file_extent_item *extent;
2296 struct btrfs_fs_info *fs_info;
2297 struct old_sa_defrag_extent *old = ctx;
2298 struct new_sa_defrag_extent *new = old->new;
2299 struct btrfs_path *path = new->path;
2300 struct btrfs_key key;
2301 struct btrfs_root *root;
2302 struct sa_defrag_extent_backref *backref;
2303 struct extent_buffer *leaf;
2304 struct inode *inode = new->inode;
2305 int slot;
2306 int ret;
2307 u64 extent_offset;
2308 u64 num_bytes;
2309
2310 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2311 inum == btrfs_ino(inode))
2312 return 0;
2313
2314 key.objectid = root_id;
2315 key.type = BTRFS_ROOT_ITEM_KEY;
2316 key.offset = (u64)-1;
2317
2318 fs_info = BTRFS_I(inode)->root->fs_info;
2319 root = btrfs_read_fs_root_no_name(fs_info, &key);
2320 if (IS_ERR(root)) {
2321 if (PTR_ERR(root) == -ENOENT)
2322 return 0;
2323 WARN_ON(1);
2324 btrfs_debug(fs_info, "inum=%llu, offset=%llu, root_id=%llu",
2325 inum, offset, root_id);
2326 return PTR_ERR(root);
2327 }
2328
2329 key.objectid = inum;
2330 key.type = BTRFS_EXTENT_DATA_KEY;
2331 if (offset > (u64)-1 << 32)
2332 key.offset = 0;
2333 else
2334 key.offset = offset;
2335
2336 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2337 if (WARN_ON(ret < 0))
2338 return ret;
2339 ret = 0;
2340
2341 while (1) {
2342 cond_resched();
2343
2344 leaf = path->nodes[0];
2345 slot = path->slots[0];
2346
2347 if (slot >= btrfs_header_nritems(leaf)) {
2348 ret = btrfs_next_leaf(root, path);
2349 if (ret < 0) {
2350 goto out;
2351 } else if (ret > 0) {
2352 ret = 0;
2353 goto out;
2354 }
2355 continue;
2356 }
2357
2358 path->slots[0]++;
2359
2360 btrfs_item_key_to_cpu(leaf, &key, slot);
2361
2362 if (key.objectid > inum)
2363 goto out;
2364
2365 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2366 continue;
2367
2368 extent = btrfs_item_ptr(leaf, slot,
2369 struct btrfs_file_extent_item);
2370
2371 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2372 continue;
2373
2374 /*
2375 * 'offset' refers to the exact key.offset,
2376 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2377 * (key.offset - extent_offset).
2378 */
2379 if (key.offset != offset)
2380 continue;
2381
2382 extent_offset = btrfs_file_extent_offset(leaf, extent);
2383 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2384
2385 if (extent_offset >= old->extent_offset + old->offset +
2386 old->len || extent_offset + num_bytes <=
2387 old->extent_offset + old->offset)
2388 continue;
2389 break;
2390 }
2391
2392 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2393 if (!backref) {
2394 ret = -ENOENT;
2395 goto out;
2396 }
2397
2398 backref->root_id = root_id;
2399 backref->inum = inum;
2400 backref->file_pos = offset;
2401 backref->num_bytes = num_bytes;
2402 backref->extent_offset = extent_offset;
2403 backref->generation = btrfs_file_extent_generation(leaf, extent);
2404 backref->old = old;
2405 backref_insert(&new->root, backref);
2406 old->count++;
2407 out:
2408 btrfs_release_path(path);
2409 WARN_ON(ret);
2410 return ret;
2411 }
2412
2413 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2414 struct new_sa_defrag_extent *new)
2415 {
2416 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
2417 struct old_sa_defrag_extent *old, *tmp;
2418 int ret;
2419
2420 new->path = path;
2421
2422 list_for_each_entry_safe(old, tmp, &new->head, list) {
2423 ret = iterate_inodes_from_logical(old->bytenr +
2424 old->extent_offset, fs_info,
2425 path, record_one_backref,
2426 old);
2427 if (ret < 0 && ret != -ENOENT)
2428 return false;
2429
2430 /* no backref to be processed for this extent */
2431 if (!old->count) {
2432 list_del(&old->list);
2433 kfree(old);
2434 }
2435 }
2436
2437 if (list_empty(&new->head))
2438 return false;
2439
2440 return true;
2441 }
2442
2443 static int relink_is_mergable(struct extent_buffer *leaf,
2444 struct btrfs_file_extent_item *fi,
2445 struct new_sa_defrag_extent *new)
2446 {
2447 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2448 return 0;
2449
2450 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2451 return 0;
2452
2453 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2454 return 0;
2455
2456 if (btrfs_file_extent_encryption(leaf, fi) ||
2457 btrfs_file_extent_other_encoding(leaf, fi))
2458 return 0;
2459
2460 return 1;
2461 }
2462
2463 /*
2464 * Note the backref might has changed, and in this case we just return 0.
2465 */
2466 static noinline int relink_extent_backref(struct btrfs_path *path,
2467 struct sa_defrag_extent_backref *prev,
2468 struct sa_defrag_extent_backref *backref)
2469 {
2470 struct btrfs_file_extent_item *extent;
2471 struct btrfs_file_extent_item *item;
2472 struct btrfs_ordered_extent *ordered;
2473 struct btrfs_trans_handle *trans;
2474 struct btrfs_fs_info *fs_info;
2475 struct btrfs_root *root;
2476 struct btrfs_key key;
2477 struct extent_buffer *leaf;
2478 struct old_sa_defrag_extent *old = backref->old;
2479 struct new_sa_defrag_extent *new = old->new;
2480 struct inode *src_inode = new->inode;
2481 struct inode *inode;
2482 struct extent_state *cached = NULL;
2483 int ret = 0;
2484 u64 start;
2485 u64 len;
2486 u64 lock_start;
2487 u64 lock_end;
2488 bool merge = false;
2489 int index;
2490
2491 if (prev && prev->root_id == backref->root_id &&
2492 prev->inum == backref->inum &&
2493 prev->file_pos + prev->num_bytes == backref->file_pos)
2494 merge = true;
2495
2496 /* step 1: get root */
2497 key.objectid = backref->root_id;
2498 key.type = BTRFS_ROOT_ITEM_KEY;
2499 key.offset = (u64)-1;
2500
2501 fs_info = BTRFS_I(src_inode)->root->fs_info;
2502 index = srcu_read_lock(&fs_info->subvol_srcu);
2503
2504 root = btrfs_read_fs_root_no_name(fs_info, &key);
2505 if (IS_ERR(root)) {
2506 srcu_read_unlock(&fs_info->subvol_srcu, index);
2507 if (PTR_ERR(root) == -ENOENT)
2508 return 0;
2509 return PTR_ERR(root);
2510 }
2511
2512 if (btrfs_root_readonly(root)) {
2513 srcu_read_unlock(&fs_info->subvol_srcu, index);
2514 return 0;
2515 }
2516
2517 /* step 2: get inode */
2518 key.objectid = backref->inum;
2519 key.type = BTRFS_INODE_ITEM_KEY;
2520 key.offset = 0;
2521
2522 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2523 if (IS_ERR(inode)) {
2524 srcu_read_unlock(&fs_info->subvol_srcu, index);
2525 return 0;
2526 }
2527
2528 srcu_read_unlock(&fs_info->subvol_srcu, index);
2529
2530 /* step 3: relink backref */
2531 lock_start = backref->file_pos;
2532 lock_end = backref->file_pos + backref->num_bytes - 1;
2533 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2534 &cached);
2535
2536 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2537 if (ordered) {
2538 btrfs_put_ordered_extent(ordered);
2539 goto out_unlock;
2540 }
2541
2542 trans = btrfs_join_transaction(root);
2543 if (IS_ERR(trans)) {
2544 ret = PTR_ERR(trans);
2545 goto out_unlock;
2546 }
2547
2548 key.objectid = backref->inum;
2549 key.type = BTRFS_EXTENT_DATA_KEY;
2550 key.offset = backref->file_pos;
2551
2552 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2553 if (ret < 0) {
2554 goto out_free_path;
2555 } else if (ret > 0) {
2556 ret = 0;
2557 goto out_free_path;
2558 }
2559
2560 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2561 struct btrfs_file_extent_item);
2562
2563 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2564 backref->generation)
2565 goto out_free_path;
2566
2567 btrfs_release_path(path);
2568
2569 start = backref->file_pos;
2570 if (backref->extent_offset < old->extent_offset + old->offset)
2571 start += old->extent_offset + old->offset -
2572 backref->extent_offset;
2573
2574 len = min(backref->extent_offset + backref->num_bytes,
2575 old->extent_offset + old->offset + old->len);
2576 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2577
2578 ret = btrfs_drop_extents(trans, root, inode, start,
2579 start + len, 1);
2580 if (ret)
2581 goto out_free_path;
2582 again:
2583 key.objectid = btrfs_ino(inode);
2584 key.type = BTRFS_EXTENT_DATA_KEY;
2585 key.offset = start;
2586
2587 path->leave_spinning = 1;
2588 if (merge) {
2589 struct btrfs_file_extent_item *fi;
2590 u64 extent_len;
2591 struct btrfs_key found_key;
2592
2593 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2594 if (ret < 0)
2595 goto out_free_path;
2596
2597 path->slots[0]--;
2598 leaf = path->nodes[0];
2599 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2600
2601 fi = btrfs_item_ptr(leaf, path->slots[0],
2602 struct btrfs_file_extent_item);
2603 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2604
2605 if (extent_len + found_key.offset == start &&
2606 relink_is_mergable(leaf, fi, new)) {
2607 btrfs_set_file_extent_num_bytes(leaf, fi,
2608 extent_len + len);
2609 btrfs_mark_buffer_dirty(leaf);
2610 inode_add_bytes(inode, len);
2611
2612 ret = 1;
2613 goto out_free_path;
2614 } else {
2615 merge = false;
2616 btrfs_release_path(path);
2617 goto again;
2618 }
2619 }
2620
2621 ret = btrfs_insert_empty_item(trans, root, path, &key,
2622 sizeof(*extent));
2623 if (ret) {
2624 btrfs_abort_transaction(trans, ret);
2625 goto out_free_path;
2626 }
2627
2628 leaf = path->nodes[0];
2629 item = btrfs_item_ptr(leaf, path->slots[0],
2630 struct btrfs_file_extent_item);
2631 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2632 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2633 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2634 btrfs_set_file_extent_num_bytes(leaf, item, len);
2635 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2636 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2637 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2638 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2639 btrfs_set_file_extent_encryption(leaf, item, 0);
2640 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2641
2642 btrfs_mark_buffer_dirty(leaf);
2643 inode_add_bytes(inode, len);
2644 btrfs_release_path(path);
2645
2646 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2647 new->disk_len, 0,
2648 backref->root_id, backref->inum,
2649 new->file_pos); /* start - extent_offset */
2650 if (ret) {
2651 btrfs_abort_transaction(trans, ret);
2652 goto out_free_path;
2653 }
2654
2655 ret = 1;
2656 out_free_path:
2657 btrfs_release_path(path);
2658 path->leave_spinning = 0;
2659 btrfs_end_transaction(trans, root);
2660 out_unlock:
2661 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2662 &cached, GFP_NOFS);
2663 iput(inode);
2664 return ret;
2665 }
2666
2667 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2668 {
2669 struct old_sa_defrag_extent *old, *tmp;
2670
2671 if (!new)
2672 return;
2673
2674 list_for_each_entry_safe(old, tmp, &new->head, list) {
2675 kfree(old);
2676 }
2677 kfree(new);
2678 }
2679
2680 static void relink_file_extents(struct new_sa_defrag_extent *new)
2681 {
2682 struct btrfs_path *path;
2683 struct sa_defrag_extent_backref *backref;
2684 struct sa_defrag_extent_backref *prev = NULL;
2685 struct inode *inode;
2686 struct btrfs_root *root;
2687 struct rb_node *node;
2688 int ret;
2689
2690 inode = new->inode;
2691 root = BTRFS_I(inode)->root;
2692
2693 path = btrfs_alloc_path();
2694 if (!path)
2695 return;
2696
2697 if (!record_extent_backrefs(path, new)) {
2698 btrfs_free_path(path);
2699 goto out;
2700 }
2701 btrfs_release_path(path);
2702
2703 while (1) {
2704 node = rb_first(&new->root);
2705 if (!node)
2706 break;
2707 rb_erase(node, &new->root);
2708
2709 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2710
2711 ret = relink_extent_backref(path, prev, backref);
2712 WARN_ON(ret < 0);
2713
2714 kfree(prev);
2715
2716 if (ret == 1)
2717 prev = backref;
2718 else
2719 prev = NULL;
2720 cond_resched();
2721 }
2722 kfree(prev);
2723
2724 btrfs_free_path(path);
2725 out:
2726 free_sa_defrag_extent(new);
2727
2728 atomic_dec(&root->fs_info->defrag_running);
2729 wake_up(&root->fs_info->transaction_wait);
2730 }
2731
2732 static struct new_sa_defrag_extent *
2733 record_old_file_extents(struct inode *inode,
2734 struct btrfs_ordered_extent *ordered)
2735 {
2736 struct btrfs_root *root = BTRFS_I(inode)->root;
2737 struct btrfs_path *path;
2738 struct btrfs_key key;
2739 struct old_sa_defrag_extent *old;
2740 struct new_sa_defrag_extent *new;
2741 int ret;
2742
2743 new = kmalloc(sizeof(*new), GFP_NOFS);
2744 if (!new)
2745 return NULL;
2746
2747 new->inode = inode;
2748 new->file_pos = ordered->file_offset;
2749 new->len = ordered->len;
2750 new->bytenr = ordered->start;
2751 new->disk_len = ordered->disk_len;
2752 new->compress_type = ordered->compress_type;
2753 new->root = RB_ROOT;
2754 INIT_LIST_HEAD(&new->head);
2755
2756 path = btrfs_alloc_path();
2757 if (!path)
2758 goto out_kfree;
2759
2760 key.objectid = btrfs_ino(inode);
2761 key.type = BTRFS_EXTENT_DATA_KEY;
2762 key.offset = new->file_pos;
2763
2764 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2765 if (ret < 0)
2766 goto out_free_path;
2767 if (ret > 0 && path->slots[0] > 0)
2768 path->slots[0]--;
2769
2770 /* find out all the old extents for the file range */
2771 while (1) {
2772 struct btrfs_file_extent_item *extent;
2773 struct extent_buffer *l;
2774 int slot;
2775 u64 num_bytes;
2776 u64 offset;
2777 u64 end;
2778 u64 disk_bytenr;
2779 u64 extent_offset;
2780
2781 l = path->nodes[0];
2782 slot = path->slots[0];
2783
2784 if (slot >= btrfs_header_nritems(l)) {
2785 ret = btrfs_next_leaf(root, path);
2786 if (ret < 0)
2787 goto out_free_path;
2788 else if (ret > 0)
2789 break;
2790 continue;
2791 }
2792
2793 btrfs_item_key_to_cpu(l, &key, slot);
2794
2795 if (key.objectid != btrfs_ino(inode))
2796 break;
2797 if (key.type != BTRFS_EXTENT_DATA_KEY)
2798 break;
2799 if (key.offset >= new->file_pos + new->len)
2800 break;
2801
2802 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2803
2804 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2805 if (key.offset + num_bytes < new->file_pos)
2806 goto next;
2807
2808 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2809 if (!disk_bytenr)
2810 goto next;
2811
2812 extent_offset = btrfs_file_extent_offset(l, extent);
2813
2814 old = kmalloc(sizeof(*old), GFP_NOFS);
2815 if (!old)
2816 goto out_free_path;
2817
2818 offset = max(new->file_pos, key.offset);
2819 end = min(new->file_pos + new->len, key.offset + num_bytes);
2820
2821 old->bytenr = disk_bytenr;
2822 old->extent_offset = extent_offset;
2823 old->offset = offset - key.offset;
2824 old->len = end - offset;
2825 old->new = new;
2826 old->count = 0;
2827 list_add_tail(&old->list, &new->head);
2828 next:
2829 path->slots[0]++;
2830 cond_resched();
2831 }
2832
2833 btrfs_free_path(path);
2834 atomic_inc(&root->fs_info->defrag_running);
2835
2836 return new;
2837
2838 out_free_path:
2839 btrfs_free_path(path);
2840 out_kfree:
2841 free_sa_defrag_extent(new);
2842 return NULL;
2843 }
2844
2845 static void btrfs_release_delalloc_bytes(struct btrfs_root *root,
2846 u64 start, u64 len)
2847 {
2848 struct btrfs_block_group_cache *cache;
2849
2850 cache = btrfs_lookup_block_group(root->fs_info, start);
2851 ASSERT(cache);
2852
2853 spin_lock(&cache->lock);
2854 cache->delalloc_bytes -= len;
2855 spin_unlock(&cache->lock);
2856
2857 btrfs_put_block_group(cache);
2858 }
2859
2860 /* as ordered data IO finishes, this gets called so we can finish
2861 * an ordered extent if the range of bytes in the file it covers are
2862 * fully written.
2863 */
2864 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2865 {
2866 struct inode *inode = ordered_extent->inode;
2867 struct btrfs_root *root = BTRFS_I(inode)->root;
2868 struct btrfs_trans_handle *trans = NULL;
2869 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2870 struct extent_state *cached_state = NULL;
2871 struct new_sa_defrag_extent *new = NULL;
2872 int compress_type = 0;
2873 int ret = 0;
2874 u64 logical_len = ordered_extent->len;
2875 bool nolock;
2876 bool truncated = false;
2877
2878 nolock = btrfs_is_free_space_inode(inode);
2879
2880 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2881 ret = -EIO;
2882 goto out;
2883 }
2884
2885 btrfs_free_io_failure_record(inode, ordered_extent->file_offset,
2886 ordered_extent->file_offset +
2887 ordered_extent->len - 1);
2888
2889 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2890 truncated = true;
2891 logical_len = ordered_extent->truncated_len;
2892 /* Truncated the entire extent, don't bother adding */
2893 if (!logical_len)
2894 goto out;
2895 }
2896
2897 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2898 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2899
2900 /*
2901 * For mwrite(mmap + memset to write) case, we still reserve
2902 * space for NOCOW range.
2903 * As NOCOW won't cause a new delayed ref, just free the space
2904 */
2905 btrfs_qgroup_free_data(inode, ordered_extent->file_offset,
2906 ordered_extent->len);
2907 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2908 if (nolock)
2909 trans = btrfs_join_transaction_nolock(root);
2910 else
2911 trans = btrfs_join_transaction(root);
2912 if (IS_ERR(trans)) {
2913 ret = PTR_ERR(trans);
2914 trans = NULL;
2915 goto out;
2916 }
2917 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2918 ret = btrfs_update_inode_fallback(trans, root, inode);
2919 if (ret) /* -ENOMEM or corruption */
2920 btrfs_abort_transaction(trans, ret);
2921 goto out;
2922 }
2923
2924 lock_extent_bits(io_tree, ordered_extent->file_offset,
2925 ordered_extent->file_offset + ordered_extent->len - 1,
2926 &cached_state);
2927
2928 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2929 ordered_extent->file_offset + ordered_extent->len - 1,
2930 EXTENT_DEFRAG, 1, cached_state);
2931 if (ret) {
2932 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2933 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
2934 /* the inode is shared */
2935 new = record_old_file_extents(inode, ordered_extent);
2936
2937 clear_extent_bit(io_tree, ordered_extent->file_offset,
2938 ordered_extent->file_offset + ordered_extent->len - 1,
2939 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2940 }
2941
2942 if (nolock)
2943 trans = btrfs_join_transaction_nolock(root);
2944 else
2945 trans = btrfs_join_transaction(root);
2946 if (IS_ERR(trans)) {
2947 ret = PTR_ERR(trans);
2948 trans = NULL;
2949 goto out_unlock;
2950 }
2951
2952 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2953
2954 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2955 compress_type = ordered_extent->compress_type;
2956 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2957 BUG_ON(compress_type);
2958 ret = btrfs_mark_extent_written(trans, inode,
2959 ordered_extent->file_offset,
2960 ordered_extent->file_offset +
2961 logical_len);
2962 } else {
2963 BUG_ON(root == root->fs_info->tree_root);
2964 ret = insert_reserved_file_extent(trans, inode,
2965 ordered_extent->file_offset,
2966 ordered_extent->start,
2967 ordered_extent->disk_len,
2968 logical_len, logical_len,
2969 compress_type, 0, 0,
2970 BTRFS_FILE_EXTENT_REG);
2971 if (!ret)
2972 btrfs_release_delalloc_bytes(root,
2973 ordered_extent->start,
2974 ordered_extent->disk_len);
2975 }
2976 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2977 ordered_extent->file_offset, ordered_extent->len,
2978 trans->transid);
2979 if (ret < 0) {
2980 btrfs_abort_transaction(trans, ret);
2981 goto out_unlock;
2982 }
2983
2984 add_pending_csums(trans, inode, ordered_extent->file_offset,
2985 &ordered_extent->list);
2986
2987 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2988 ret = btrfs_update_inode_fallback(trans, root, inode);
2989 if (ret) { /* -ENOMEM or corruption */
2990 btrfs_abort_transaction(trans, ret);
2991 goto out_unlock;
2992 }
2993 ret = 0;
2994 out_unlock:
2995 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2996 ordered_extent->file_offset +
2997 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2998 out:
2999 if (root != root->fs_info->tree_root)
3000 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
3001 if (trans)
3002 btrfs_end_transaction(trans, root);
3003
3004 if (ret || truncated) {
3005 u64 start, end;
3006
3007 if (truncated)
3008 start = ordered_extent->file_offset + logical_len;
3009 else
3010 start = ordered_extent->file_offset;
3011 end = ordered_extent->file_offset + ordered_extent->len - 1;
3012 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
3013
3014 /* Drop the cache for the part of the extent we didn't write. */
3015 btrfs_drop_extent_cache(inode, start, end, 0);
3016
3017 /*
3018 * If the ordered extent had an IOERR or something else went
3019 * wrong we need to return the space for this ordered extent
3020 * back to the allocator. We only free the extent in the
3021 * truncated case if we didn't write out the extent at all.
3022 */
3023 if ((ret || !logical_len) &&
3024 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
3025 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
3026 btrfs_free_reserved_extent(root, ordered_extent->start,
3027 ordered_extent->disk_len, 1);
3028 }
3029
3030
3031 /*
3032 * This needs to be done to make sure anybody waiting knows we are done
3033 * updating everything for this ordered extent.
3034 */
3035 btrfs_remove_ordered_extent(inode, ordered_extent);
3036
3037 /* for snapshot-aware defrag */
3038 if (new) {
3039 if (ret) {
3040 free_sa_defrag_extent(new);
3041 atomic_dec(&root->fs_info->defrag_running);
3042 } else {
3043 relink_file_extents(new);
3044 }
3045 }
3046
3047 /* once for us */
3048 btrfs_put_ordered_extent(ordered_extent);
3049 /* once for the tree */
3050 btrfs_put_ordered_extent(ordered_extent);
3051
3052 return ret;
3053 }
3054
3055 static void finish_ordered_fn(struct btrfs_work *work)
3056 {
3057 struct btrfs_ordered_extent *ordered_extent;
3058 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
3059 btrfs_finish_ordered_io(ordered_extent);
3060 }
3061
3062 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
3063 struct extent_state *state, int uptodate)
3064 {
3065 struct inode *inode = page->mapping->host;
3066 struct btrfs_root *root = BTRFS_I(inode)->root;
3067 struct btrfs_ordered_extent *ordered_extent = NULL;
3068 struct btrfs_workqueue *wq;
3069 btrfs_work_func_t func;
3070
3071 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
3072
3073 ClearPagePrivate2(page);
3074 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
3075 end - start + 1, uptodate))
3076 return 0;
3077
3078 if (btrfs_is_free_space_inode(inode)) {
3079 wq = root->fs_info->endio_freespace_worker;
3080 func = btrfs_freespace_write_helper;
3081 } else {
3082 wq = root->fs_info->endio_write_workers;
3083 func = btrfs_endio_write_helper;
3084 }
3085
3086 btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
3087 NULL);
3088 btrfs_queue_work(wq, &ordered_extent->work);
3089
3090 return 0;
3091 }
3092
3093 static int __readpage_endio_check(struct inode *inode,
3094 struct btrfs_io_bio *io_bio,
3095 int icsum, struct page *page,
3096 int pgoff, u64 start, size_t len)
3097 {
3098 char *kaddr;
3099 u32 csum_expected;
3100 u32 csum = ~(u32)0;
3101
3102 csum_expected = *(((u32 *)io_bio->csum) + icsum);
3103
3104 kaddr = kmap_atomic(page);
3105 csum = btrfs_csum_data(kaddr + pgoff, csum, len);
3106 btrfs_csum_final(csum, (char *)&csum);
3107 if (csum != csum_expected)
3108 goto zeroit;
3109
3110 kunmap_atomic(kaddr);
3111 return 0;
3112 zeroit:
3113 btrfs_warn_rl(BTRFS_I(inode)->root->fs_info,
3114 "csum failed ino %llu off %llu csum %u expected csum %u",
3115 btrfs_ino(inode), start, csum, csum_expected);
3116 memset(kaddr + pgoff, 1, len);
3117 flush_dcache_page(page);
3118 kunmap_atomic(kaddr);
3119 if (csum_expected == 0)
3120 return 0;
3121 return -EIO;
3122 }
3123
3124 /*
3125 * when reads are done, we need to check csums to verify the data is correct
3126 * if there's a match, we allow the bio to finish. If not, the code in
3127 * extent_io.c will try to find good copies for us.
3128 */
3129 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
3130 u64 phy_offset, struct page *page,
3131 u64 start, u64 end, int mirror)
3132 {
3133 size_t offset = start - page_offset(page);
3134 struct inode *inode = page->mapping->host;
3135 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3136 struct btrfs_root *root = BTRFS_I(inode)->root;
3137
3138 if (PageChecked(page)) {
3139 ClearPageChecked(page);
3140 return 0;
3141 }
3142
3143 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3144 return 0;
3145
3146 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
3147 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
3148 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM);
3149 return 0;
3150 }
3151
3152 phy_offset >>= inode->i_sb->s_blocksize_bits;
3153 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3154 start, (size_t)(end - start + 1));
3155 }
3156
3157 void btrfs_add_delayed_iput(struct inode *inode)
3158 {
3159 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
3160 struct btrfs_inode *binode = BTRFS_I(inode);
3161
3162 if (atomic_add_unless(&inode->i_count, -1, 1))
3163 return;
3164
3165 spin_lock(&fs_info->delayed_iput_lock);
3166 if (binode->delayed_iput_count == 0) {
3167 ASSERT(list_empty(&binode->delayed_iput));
3168 list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
3169 } else {
3170 binode->delayed_iput_count++;
3171 }
3172 spin_unlock(&fs_info->delayed_iput_lock);
3173 }
3174
3175 void btrfs_run_delayed_iputs(struct btrfs_root *root)
3176 {
3177 struct btrfs_fs_info *fs_info = root->fs_info;
3178
3179 spin_lock(&fs_info->delayed_iput_lock);
3180 while (!list_empty(&fs_info->delayed_iputs)) {
3181 struct btrfs_inode *inode;
3182
3183 inode = list_first_entry(&fs_info->delayed_iputs,
3184 struct btrfs_inode, delayed_iput);
3185 if (inode->delayed_iput_count) {
3186 inode->delayed_iput_count--;
3187 list_move_tail(&inode->delayed_iput,
3188 &fs_info->delayed_iputs);
3189 } else {
3190 list_del_init(&inode->delayed_iput);
3191 }
3192 spin_unlock(&fs_info->delayed_iput_lock);
3193 iput(&inode->vfs_inode);
3194 spin_lock(&fs_info->delayed_iput_lock);
3195 }
3196 spin_unlock(&fs_info->delayed_iput_lock);
3197 }
3198
3199 /*
3200 * This is called in transaction commit time. If there are no orphan
3201 * files in the subvolume, it removes orphan item and frees block_rsv
3202 * structure.
3203 */
3204 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
3205 struct btrfs_root *root)
3206 {
3207 struct btrfs_block_rsv *block_rsv;
3208 int ret;
3209
3210 if (atomic_read(&root->orphan_inodes) ||
3211 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
3212 return;
3213
3214 spin_lock(&root->orphan_lock);
3215 if (atomic_read(&root->orphan_inodes)) {
3216 spin_unlock(&root->orphan_lock);
3217 return;
3218 }
3219
3220 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
3221 spin_unlock(&root->orphan_lock);
3222 return;
3223 }
3224
3225 block_rsv = root->orphan_block_rsv;
3226 root->orphan_block_rsv = NULL;
3227 spin_unlock(&root->orphan_lock);
3228
3229 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
3230 btrfs_root_refs(&root->root_item) > 0) {
3231 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
3232 root->root_key.objectid);
3233 if (ret)
3234 btrfs_abort_transaction(trans, ret);
3235 else
3236 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
3237 &root->state);
3238 }
3239
3240 if (block_rsv) {
3241 WARN_ON(block_rsv->size > 0);
3242 btrfs_free_block_rsv(root, block_rsv);
3243 }
3244 }
3245
3246 /*
3247 * This creates an orphan entry for the given inode in case something goes
3248 * wrong in the middle of an unlink/truncate.
3249 *
3250 * NOTE: caller of this function should reserve 5 units of metadata for
3251 * this function.
3252 */
3253 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
3254 {
3255 struct btrfs_root *root = BTRFS_I(inode)->root;
3256 struct btrfs_block_rsv *block_rsv = NULL;
3257 int reserve = 0;
3258 int insert = 0;
3259 int ret;
3260
3261 if (!root->orphan_block_rsv) {
3262 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
3263 if (!block_rsv)
3264 return -ENOMEM;
3265 }
3266
3267 spin_lock(&root->orphan_lock);
3268 if (!root->orphan_block_rsv) {
3269 root->orphan_block_rsv = block_rsv;
3270 } else if (block_rsv) {
3271 btrfs_free_block_rsv(root, block_rsv);
3272 block_rsv = NULL;
3273 }
3274
3275 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3276 &BTRFS_I(inode)->runtime_flags)) {
3277 #if 0
3278 /*
3279 * For proper ENOSPC handling, we should do orphan
3280 * cleanup when mounting. But this introduces backward
3281 * compatibility issue.
3282 */
3283 if (!xchg(&root->orphan_item_inserted, 1))
3284 insert = 2;
3285 else
3286 insert = 1;
3287 #endif
3288 insert = 1;
3289 atomic_inc(&root->orphan_inodes);
3290 }
3291
3292 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3293 &BTRFS_I(inode)->runtime_flags))
3294 reserve = 1;
3295 spin_unlock(&root->orphan_lock);
3296
3297 /* grab metadata reservation from transaction handle */
3298 if (reserve) {
3299 ret = btrfs_orphan_reserve_metadata(trans, inode);
3300 ASSERT(!ret);
3301 if (ret) {
3302 atomic_dec(&root->orphan_inodes);
3303 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3304 &BTRFS_I(inode)->runtime_flags);
3305 if (insert)
3306 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3307 &BTRFS_I(inode)->runtime_flags);
3308 return ret;
3309 }
3310 }
3311
3312 /* insert an orphan item to track this unlinked/truncated file */
3313 if (insert >= 1) {
3314 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3315 if (ret) {
3316 atomic_dec(&root->orphan_inodes);
3317 if (reserve) {
3318 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3319 &BTRFS_I(inode)->runtime_flags);
3320 btrfs_orphan_release_metadata(inode);
3321 }
3322 if (ret != -EEXIST) {
3323 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3324 &BTRFS_I(inode)->runtime_flags);
3325 btrfs_abort_transaction(trans, ret);
3326 return ret;
3327 }
3328 }
3329 ret = 0;
3330 }
3331
3332 /* insert an orphan item to track subvolume contains orphan files */
3333 if (insert >= 2) {
3334 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
3335 root->root_key.objectid);
3336 if (ret && ret != -EEXIST) {
3337 btrfs_abort_transaction(trans, ret);
3338 return ret;
3339 }
3340 }
3341 return 0;
3342 }
3343
3344 /*
3345 * We have done the truncate/delete so we can go ahead and remove the orphan
3346 * item for this particular inode.
3347 */
3348 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3349 struct inode *inode)
3350 {
3351 struct btrfs_root *root = BTRFS_I(inode)->root;
3352 int delete_item = 0;
3353 int release_rsv = 0;
3354 int ret = 0;
3355
3356 spin_lock(&root->orphan_lock);
3357 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3358 &BTRFS_I(inode)->runtime_flags))
3359 delete_item = 1;
3360
3361 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3362 &BTRFS_I(inode)->runtime_flags))
3363 release_rsv = 1;
3364 spin_unlock(&root->orphan_lock);
3365
3366 if (delete_item) {
3367 atomic_dec(&root->orphan_inodes);
3368 if (trans)
3369 ret = btrfs_del_orphan_item(trans, root,
3370 btrfs_ino(inode));
3371 }
3372
3373 if (release_rsv)
3374 btrfs_orphan_release_metadata(inode);
3375
3376 return ret;
3377 }
3378
3379 /*
3380 * this cleans up any orphans that may be left on the list from the last use
3381 * of this root.
3382 */
3383 int btrfs_orphan_cleanup(struct btrfs_root *root)
3384 {
3385 struct btrfs_path *path;
3386 struct extent_buffer *leaf;
3387 struct btrfs_key key, found_key;
3388 struct btrfs_trans_handle *trans;
3389 struct inode *inode;
3390 u64 last_objectid = 0;
3391 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3392
3393 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3394 return 0;
3395
3396 path = btrfs_alloc_path();
3397 if (!path) {
3398 ret = -ENOMEM;
3399 goto out;
3400 }
3401 path->reada = READA_BACK;
3402
3403 key.objectid = BTRFS_ORPHAN_OBJECTID;
3404 key.type = BTRFS_ORPHAN_ITEM_KEY;
3405 key.offset = (u64)-1;
3406
3407 while (1) {
3408 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3409 if (ret < 0)
3410 goto out;
3411
3412 /*
3413 * if ret == 0 means we found what we were searching for, which
3414 * is weird, but possible, so only screw with path if we didn't
3415 * find the key and see if we have stuff that matches
3416 */
3417 if (ret > 0) {
3418 ret = 0;
3419 if (path->slots[0] == 0)
3420 break;
3421 path->slots[0]--;
3422 }
3423
3424 /* pull out the item */
3425 leaf = path->nodes[0];
3426 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3427
3428 /* make sure the item matches what we want */
3429 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3430 break;
3431 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3432 break;
3433
3434 /* release the path since we're done with it */
3435 btrfs_release_path(path);
3436
3437 /*
3438 * this is where we are basically btrfs_lookup, without the
3439 * crossing root thing. we store the inode number in the
3440 * offset of the orphan item.
3441 */
3442
3443 if (found_key.offset == last_objectid) {
3444 btrfs_err(root->fs_info,
3445 "Error removing orphan entry, stopping orphan cleanup");
3446 ret = -EINVAL;
3447 goto out;
3448 }
3449
3450 last_objectid = found_key.offset;
3451
3452 found_key.objectid = found_key.offset;
3453 found_key.type = BTRFS_INODE_ITEM_KEY;
3454 found_key.offset = 0;
3455 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3456 ret = PTR_ERR_OR_ZERO(inode);
3457 if (ret && ret != -ENOENT)
3458 goto out;
3459
3460 if (ret == -ENOENT && root == root->fs_info->tree_root) {
3461 struct btrfs_root *dead_root;
3462 struct btrfs_fs_info *fs_info = root->fs_info;
3463 int is_dead_root = 0;
3464
3465 /*
3466 * this is an orphan in the tree root. Currently these
3467 * could come from 2 sources:
3468 * a) a snapshot deletion in progress
3469 * b) a free space cache inode
3470 * We need to distinguish those two, as the snapshot
3471 * orphan must not get deleted.
3472 * find_dead_roots already ran before us, so if this
3473 * is a snapshot deletion, we should find the root
3474 * in the dead_roots list
3475 */
3476 spin_lock(&fs_info->trans_lock);
3477 list_for_each_entry(dead_root, &fs_info->dead_roots,
3478 root_list) {
3479 if (dead_root->root_key.objectid ==
3480 found_key.objectid) {
3481 is_dead_root = 1;
3482 break;
3483 }
3484 }
3485 spin_unlock(&fs_info->trans_lock);
3486 if (is_dead_root) {
3487 /* prevent this orphan from being found again */
3488 key.offset = found_key.objectid - 1;
3489 continue;
3490 }
3491 }
3492 /*
3493 * Inode is already gone but the orphan item is still there,
3494 * kill the orphan item.
3495 */
3496 if (ret == -ENOENT) {
3497 trans = btrfs_start_transaction(root, 1);
3498 if (IS_ERR(trans)) {
3499 ret = PTR_ERR(trans);
3500 goto out;
3501 }
3502 btrfs_debug(root->fs_info, "auto deleting %Lu",
3503 found_key.objectid);
3504 ret = btrfs_del_orphan_item(trans, root,
3505 found_key.objectid);
3506 btrfs_end_transaction(trans, root);
3507 if (ret)
3508 goto out;
3509 continue;
3510 }
3511
3512 /*
3513 * add this inode to the orphan list so btrfs_orphan_del does
3514 * the proper thing when we hit it
3515 */
3516 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3517 &BTRFS_I(inode)->runtime_flags);
3518 atomic_inc(&root->orphan_inodes);
3519
3520 /* if we have links, this was a truncate, lets do that */
3521 if (inode->i_nlink) {
3522 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3523 iput(inode);
3524 continue;
3525 }
3526 nr_truncate++;
3527
3528 /* 1 for the orphan item deletion. */
3529 trans = btrfs_start_transaction(root, 1);
3530 if (IS_ERR(trans)) {
3531 iput(inode);
3532 ret = PTR_ERR(trans);
3533 goto out;
3534 }
3535 ret = btrfs_orphan_add(trans, inode);
3536 btrfs_end_transaction(trans, root);
3537 if (ret) {
3538 iput(inode);
3539 goto out;
3540 }
3541
3542 ret = btrfs_truncate(inode);
3543 if (ret)
3544 btrfs_orphan_del(NULL, inode);
3545 } else {
3546 nr_unlink++;
3547 }
3548
3549 /* this will do delete_inode and everything for us */
3550 iput(inode);
3551 if (ret)
3552 goto out;
3553 }
3554 /* release the path since we're done with it */
3555 btrfs_release_path(path);
3556
3557 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3558
3559 if (root->orphan_block_rsv)
3560 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3561 (u64)-1);
3562
3563 if (root->orphan_block_rsv ||
3564 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3565 trans = btrfs_join_transaction(root);
3566 if (!IS_ERR(trans))
3567 btrfs_end_transaction(trans, root);
3568 }
3569
3570 if (nr_unlink)
3571 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3572 if (nr_truncate)
3573 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3574
3575 out:
3576 if (ret)
3577 btrfs_err(root->fs_info,
3578 "could not do orphan cleanup %d", ret);
3579 btrfs_free_path(path);
3580 return ret;
3581 }
3582
3583 /*
3584 * very simple check to peek ahead in the leaf looking for xattrs. If we
3585 * don't find any xattrs, we know there can't be any acls.
3586 *
3587 * slot is the slot the inode is in, objectid is the objectid of the inode
3588 */
3589 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3590 int slot, u64 objectid,
3591 int *first_xattr_slot)
3592 {
3593 u32 nritems = btrfs_header_nritems(leaf);
3594 struct btrfs_key found_key;
3595 static u64 xattr_access = 0;
3596 static u64 xattr_default = 0;
3597 int scanned = 0;
3598
3599 if (!xattr_access) {
3600 xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
3601 strlen(XATTR_NAME_POSIX_ACL_ACCESS));
3602 xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
3603 strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
3604 }
3605
3606 slot++;
3607 *first_xattr_slot = -1;
3608 while (slot < nritems) {
3609 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3610
3611 /* we found a different objectid, there must not be acls */
3612 if (found_key.objectid != objectid)
3613 return 0;
3614
3615 /* we found an xattr, assume we've got an acl */
3616 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3617 if (*first_xattr_slot == -1)
3618 *first_xattr_slot = slot;
3619 if (found_key.offset == xattr_access ||
3620 found_key.offset == xattr_default)
3621 return 1;
3622 }
3623
3624 /*
3625 * we found a key greater than an xattr key, there can't
3626 * be any acls later on
3627 */
3628 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3629 return 0;
3630
3631 slot++;
3632 scanned++;
3633
3634 /*
3635 * it goes inode, inode backrefs, xattrs, extents,
3636 * so if there are a ton of hard links to an inode there can
3637 * be a lot of backrefs. Don't waste time searching too hard,
3638 * this is just an optimization
3639 */
3640 if (scanned >= 8)
3641 break;
3642 }
3643 /* we hit the end of the leaf before we found an xattr or
3644 * something larger than an xattr. We have to assume the inode
3645 * has acls
3646 */
3647 if (*first_xattr_slot == -1)
3648 *first_xattr_slot = slot;
3649 return 1;
3650 }
3651
3652 /*
3653 * read an inode from the btree into the in-memory inode
3654 */
3655 static int btrfs_read_locked_inode(struct inode *inode)
3656 {
3657 struct btrfs_path *path;
3658 struct extent_buffer *leaf;
3659 struct btrfs_inode_item *inode_item;
3660 struct btrfs_root *root = BTRFS_I(inode)->root;
3661 struct btrfs_key location;
3662 unsigned long ptr;
3663 int maybe_acls;
3664 u32 rdev;
3665 int ret;
3666 bool filled = false;
3667 int first_xattr_slot;
3668
3669 ret = btrfs_fill_inode(inode, &rdev);
3670 if (!ret)
3671 filled = true;
3672
3673 path = btrfs_alloc_path();
3674 if (!path) {
3675 ret = -ENOMEM;
3676 goto make_bad;
3677 }
3678
3679 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3680
3681 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3682 if (ret) {
3683 if (ret > 0)
3684 ret = -ENOENT;
3685 goto make_bad;
3686 }
3687
3688 leaf = path->nodes[0];
3689
3690 if (filled)
3691 goto cache_index;
3692
3693 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3694 struct btrfs_inode_item);
3695 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3696 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3697 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3698 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3699 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3700
3701 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3702 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3703
3704 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3705 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3706
3707 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3708 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3709
3710 BTRFS_I(inode)->i_otime.tv_sec =
3711 btrfs_timespec_sec(leaf, &inode_item->otime);
3712 BTRFS_I(inode)->i_otime.tv_nsec =
3713 btrfs_timespec_nsec(leaf, &inode_item->otime);
3714
3715 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3716 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3717 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3718
3719 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3720 inode->i_generation = BTRFS_I(inode)->generation;
3721 inode->i_rdev = 0;
3722 rdev = btrfs_inode_rdev(leaf, inode_item);
3723
3724 BTRFS_I(inode)->index_cnt = (u64)-1;
3725 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3726
3727 cache_index:
3728 /*
3729 * If we were modified in the current generation and evicted from memory
3730 * and then re-read we need to do a full sync since we don't have any
3731 * idea about which extents were modified before we were evicted from
3732 * cache.
3733 *
3734 * This is required for both inode re-read from disk and delayed inode
3735 * in delayed_nodes_tree.
3736 */
3737 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3738 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3739 &BTRFS_I(inode)->runtime_flags);
3740
3741 /*
3742 * We don't persist the id of the transaction where an unlink operation
3743 * against the inode was last made. So here we assume the inode might
3744 * have been evicted, and therefore the exact value of last_unlink_trans
3745 * lost, and set it to last_trans to avoid metadata inconsistencies
3746 * between the inode and its parent if the inode is fsync'ed and the log
3747 * replayed. For example, in the scenario:
3748 *
3749 * touch mydir/foo
3750 * ln mydir/foo mydir/bar
3751 * sync
3752 * unlink mydir/bar
3753 * echo 2 > /proc/sys/vm/drop_caches # evicts inode
3754 * xfs_io -c fsync mydir/foo
3755 * <power failure>
3756 * mount fs, triggers fsync log replay
3757 *
3758 * We must make sure that when we fsync our inode foo we also log its
3759 * parent inode, otherwise after log replay the parent still has the
3760 * dentry with the "bar" name but our inode foo has a link count of 1
3761 * and doesn't have an inode ref with the name "bar" anymore.
3762 *
3763 * Setting last_unlink_trans to last_trans is a pessimistic approach,
3764 * but it guarantees correctness at the expense of occasional full
3765 * transaction commits on fsync if our inode is a directory, or if our
3766 * inode is not a directory, logging its parent unnecessarily.
3767 */
3768 BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
3769
3770 path->slots[0]++;
3771 if (inode->i_nlink != 1 ||
3772 path->slots[0] >= btrfs_header_nritems(leaf))
3773 goto cache_acl;
3774
3775 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3776 if (location.objectid != btrfs_ino(inode))
3777 goto cache_acl;
3778
3779 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3780 if (location.type == BTRFS_INODE_REF_KEY) {
3781 struct btrfs_inode_ref *ref;
3782
3783 ref = (struct btrfs_inode_ref *)ptr;
3784 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3785 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3786 struct btrfs_inode_extref *extref;
3787
3788 extref = (struct btrfs_inode_extref *)ptr;
3789 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3790 extref);
3791 }
3792 cache_acl:
3793 /*
3794 * try to precache a NULL acl entry for files that don't have
3795 * any xattrs or acls
3796 */
3797 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3798 btrfs_ino(inode), &first_xattr_slot);
3799 if (first_xattr_slot != -1) {
3800 path->slots[0] = first_xattr_slot;
3801 ret = btrfs_load_inode_props(inode, path);
3802 if (ret)
3803 btrfs_err(root->fs_info,
3804 "error loading props for ino %llu (root %llu): %d",
3805 btrfs_ino(inode),
3806 root->root_key.objectid, ret);
3807 }
3808 btrfs_free_path(path);
3809
3810 if (!maybe_acls)
3811 cache_no_acl(inode);
3812
3813 switch (inode->i_mode & S_IFMT) {
3814 case S_IFREG:
3815 inode->i_mapping->a_ops = &btrfs_aops;
3816 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3817 inode->i_fop = &btrfs_file_operations;
3818 inode->i_op = &btrfs_file_inode_operations;
3819 break;
3820 case S_IFDIR:
3821 inode->i_fop = &btrfs_dir_file_operations;
3822 if (root == root->fs_info->tree_root)
3823 inode->i_op = &btrfs_dir_ro_inode_operations;
3824 else
3825 inode->i_op = &btrfs_dir_inode_operations;
3826 break;
3827 case S_IFLNK:
3828 inode->i_op = &btrfs_symlink_inode_operations;
3829 inode_nohighmem(inode);
3830 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3831 break;
3832 default:
3833 inode->i_op = &btrfs_special_inode_operations;
3834 init_special_inode(inode, inode->i_mode, rdev);
3835 break;
3836 }
3837
3838 btrfs_update_iflags(inode);
3839 return 0;
3840
3841 make_bad:
3842 btrfs_free_path(path);
3843 make_bad_inode(inode);
3844 return ret;
3845 }
3846
3847 /*
3848 * given a leaf and an inode, copy the inode fields into the leaf
3849 */
3850 static void fill_inode_item(struct btrfs_trans_handle *trans,
3851 struct extent_buffer *leaf,
3852 struct btrfs_inode_item *item,
3853 struct inode *inode)
3854 {
3855 struct btrfs_map_token token;
3856
3857 btrfs_init_map_token(&token);
3858
3859 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3860 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3861 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3862 &token);
3863 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3864 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3865
3866 btrfs_set_token_timespec_sec(leaf, &item->atime,
3867 inode->i_atime.tv_sec, &token);
3868 btrfs_set_token_timespec_nsec(leaf, &item->atime,
3869 inode->i_atime.tv_nsec, &token);
3870
3871 btrfs_set_token_timespec_sec(leaf, &item->mtime,
3872 inode->i_mtime.tv_sec, &token);
3873 btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3874 inode->i_mtime.tv_nsec, &token);
3875
3876 btrfs_set_token_timespec_sec(leaf, &item->ctime,
3877 inode->i_ctime.tv_sec, &token);
3878 btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3879 inode->i_ctime.tv_nsec, &token);
3880
3881 btrfs_set_token_timespec_sec(leaf, &item->otime,
3882 BTRFS_I(inode)->i_otime.tv_sec, &token);
3883 btrfs_set_token_timespec_nsec(leaf, &item->otime,
3884 BTRFS_I(inode)->i_otime.tv_nsec, &token);
3885
3886 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3887 &token);
3888 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3889 &token);
3890 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3891 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3892 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3893 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3894 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3895 }
3896
3897 /*
3898 * copy everything in the in-memory inode into the btree.
3899 */
3900 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3901 struct btrfs_root *root, struct inode *inode)
3902 {
3903 struct btrfs_inode_item *inode_item;
3904 struct btrfs_path *path;
3905 struct extent_buffer *leaf;
3906 int ret;
3907
3908 path = btrfs_alloc_path();
3909 if (!path)
3910 return -ENOMEM;
3911
3912 path->leave_spinning = 1;
3913 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3914 1);
3915 if (ret) {
3916 if (ret > 0)
3917 ret = -ENOENT;
3918 goto failed;
3919 }
3920
3921 leaf = path->nodes[0];
3922 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3923 struct btrfs_inode_item);
3924
3925 fill_inode_item(trans, leaf, inode_item, inode);
3926 btrfs_mark_buffer_dirty(leaf);
3927 btrfs_set_inode_last_trans(trans, inode);
3928 ret = 0;
3929 failed:
3930 btrfs_free_path(path);
3931 return ret;
3932 }
3933
3934 /*
3935 * copy everything in the in-memory inode into the btree.
3936 */
3937 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3938 struct btrfs_root *root, struct inode *inode)
3939 {
3940 int ret;
3941
3942 /*
3943 * If the inode is a free space inode, we can deadlock during commit
3944 * if we put it into the delayed code.
3945 *
3946 * The data relocation inode should also be directly updated
3947 * without delay
3948 */
3949 if (!btrfs_is_free_space_inode(inode)
3950 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
3951 && !test_bit(BTRFS_FS_LOG_RECOVERING, &root->fs_info->flags)) {
3952 btrfs_update_root_times(trans, root);
3953
3954 ret = btrfs_delayed_update_inode(trans, root, inode);
3955 if (!ret)
3956 btrfs_set_inode_last_trans(trans, inode);
3957 return ret;
3958 }
3959
3960 return btrfs_update_inode_item(trans, root, inode);
3961 }
3962
3963 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3964 struct btrfs_root *root,
3965 struct inode *inode)
3966 {
3967 int ret;
3968
3969 ret = btrfs_update_inode(trans, root, inode);
3970 if (ret == -ENOSPC)
3971 return btrfs_update_inode_item(trans, root, inode);
3972 return ret;
3973 }
3974
3975 /*
3976 * unlink helper that gets used here in inode.c and in the tree logging
3977 * recovery code. It remove a link in a directory with a given name, and
3978 * also drops the back refs in the inode to the directory
3979 */
3980 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3981 struct btrfs_root *root,
3982 struct inode *dir, struct inode *inode,
3983 const char *name, int name_len)
3984 {
3985 struct btrfs_path *path;
3986 int ret = 0;
3987 struct extent_buffer *leaf;
3988 struct btrfs_dir_item *di;
3989 struct btrfs_key key;
3990 u64 index;
3991 u64 ino = btrfs_ino(inode);
3992 u64 dir_ino = btrfs_ino(dir);
3993
3994 path = btrfs_alloc_path();
3995 if (!path) {
3996 ret = -ENOMEM;
3997 goto out;
3998 }
3999
4000 path->leave_spinning = 1;
4001 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4002 name, name_len, -1);
4003 if (IS_ERR(di)) {
4004 ret = PTR_ERR(di);
4005 goto err;
4006 }
4007 if (!di) {
4008 ret = -ENOENT;
4009 goto err;
4010 }
4011 leaf = path->nodes[0];
4012 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4013 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4014 if (ret)
4015 goto err;
4016 btrfs_release_path(path);
4017
4018 /*
4019 * If we don't have dir index, we have to get it by looking up
4020 * the inode ref, since we get the inode ref, remove it directly,
4021 * it is unnecessary to do delayed deletion.
4022 *
4023 * But if we have dir index, needn't search inode ref to get it.
4024 * Since the inode ref is close to the inode item, it is better
4025 * that we delay to delete it, and just do this deletion when
4026 * we update the inode item.
4027 */
4028 if (BTRFS_I(inode)->dir_index) {
4029 ret = btrfs_delayed_delete_inode_ref(inode);
4030 if (!ret) {
4031 index = BTRFS_I(inode)->dir_index;
4032 goto skip_backref;
4033 }
4034 }
4035
4036 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
4037 dir_ino, &index);
4038 if (ret) {
4039 btrfs_info(root->fs_info,
4040 "failed to delete reference to %.*s, inode %llu parent %llu",
4041 name_len, name, ino, dir_ino);
4042 btrfs_abort_transaction(trans, ret);
4043 goto err;
4044 }
4045 skip_backref:
4046 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
4047 if (ret) {
4048 btrfs_abort_transaction(trans, ret);
4049 goto err;
4050 }
4051
4052 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
4053 inode, dir_ino);
4054 if (ret != 0 && ret != -ENOENT) {
4055 btrfs_abort_transaction(trans, ret);
4056 goto err;
4057 }
4058
4059 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
4060 dir, index);
4061 if (ret == -ENOENT)
4062 ret = 0;
4063 else if (ret)
4064 btrfs_abort_transaction(trans, ret);
4065 err:
4066 btrfs_free_path(path);
4067 if (ret)
4068 goto out;
4069
4070 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4071 inode_inc_iversion(inode);
4072 inode_inc_iversion(dir);
4073 inode->i_ctime = dir->i_mtime =
4074 dir->i_ctime = current_time(inode);
4075 ret = btrfs_update_inode(trans, root, dir);
4076 out:
4077 return ret;
4078 }
4079
4080 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4081 struct btrfs_root *root,
4082 struct inode *dir, struct inode *inode,
4083 const char *name, int name_len)
4084 {
4085 int ret;
4086 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
4087 if (!ret) {
4088 drop_nlink(inode);
4089 ret = btrfs_update_inode(trans, root, inode);
4090 }
4091 return ret;
4092 }
4093
4094 /*
4095 * helper to start transaction for unlink and rmdir.
4096 *
4097 * unlink and rmdir are special in btrfs, they do not always free space, so
4098 * if we cannot make our reservations the normal way try and see if there is
4099 * plenty of slack room in the global reserve to migrate, otherwise we cannot
4100 * allow the unlink to occur.
4101 */
4102 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
4103 {
4104 struct btrfs_root *root = BTRFS_I(dir)->root;
4105
4106 /*
4107 * 1 for the possible orphan item
4108 * 1 for the dir item
4109 * 1 for the dir index
4110 * 1 for the inode ref
4111 * 1 for the inode
4112 */
4113 return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
4114 }
4115
4116 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4117 {
4118 struct btrfs_root *root = BTRFS_I(dir)->root;
4119 struct btrfs_trans_handle *trans;
4120 struct inode *inode = d_inode(dentry);
4121 int ret;
4122
4123 trans = __unlink_start_trans(dir);
4124 if (IS_ERR(trans))
4125 return PTR_ERR(trans);
4126
4127 btrfs_record_unlink_dir(trans, dir, d_inode(dentry), 0);
4128
4129 ret = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4130 dentry->d_name.name, dentry->d_name.len);
4131 if (ret)
4132 goto out;
4133
4134 if (inode->i_nlink == 0) {
4135 ret = btrfs_orphan_add(trans, inode);
4136 if (ret)
4137 goto out;
4138 }
4139
4140 out:
4141 btrfs_end_transaction(trans, root);
4142 btrfs_btree_balance_dirty(root);
4143 return ret;
4144 }
4145
4146 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4147 struct btrfs_root *root,
4148 struct inode *dir, u64 objectid,
4149 const char *name, int name_len)
4150 {
4151 struct btrfs_path *path;
4152 struct extent_buffer *leaf;
4153 struct btrfs_dir_item *di;
4154 struct btrfs_key key;
4155 u64 index;
4156 int ret;
4157 u64 dir_ino = btrfs_ino(dir);
4158
4159 path = btrfs_alloc_path();
4160 if (!path)
4161 return -ENOMEM;
4162
4163 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4164 name, name_len, -1);
4165 if (IS_ERR_OR_NULL(di)) {
4166 if (!di)
4167 ret = -ENOENT;
4168 else
4169 ret = PTR_ERR(di);
4170 goto out;
4171 }
4172
4173 leaf = path->nodes[0];
4174 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4175 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4176 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4177 if (ret) {
4178 btrfs_abort_transaction(trans, ret);
4179 goto out;
4180 }
4181 btrfs_release_path(path);
4182
4183 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
4184 objectid, root->root_key.objectid,
4185 dir_ino, &index, name, name_len);
4186 if (ret < 0) {
4187 if (ret != -ENOENT) {
4188 btrfs_abort_transaction(trans, ret);
4189 goto out;
4190 }
4191 di = btrfs_search_dir_index_item(root, path, dir_ino,
4192 name, name_len);
4193 if (IS_ERR_OR_NULL(di)) {
4194 if (!di)
4195 ret = -ENOENT;
4196 else
4197 ret = PTR_ERR(di);
4198 btrfs_abort_transaction(trans, ret);
4199 goto out;
4200 }
4201
4202 leaf = path->nodes[0];
4203 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4204 btrfs_release_path(path);
4205 index = key.offset;
4206 }
4207 btrfs_release_path(path);
4208
4209 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
4210 if (ret) {
4211 btrfs_abort_transaction(trans, ret);
4212 goto out;
4213 }
4214
4215 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4216 inode_inc_iversion(dir);
4217 dir->i_mtime = dir->i_ctime = current_time(dir);
4218 ret = btrfs_update_inode_fallback(trans, root, dir);
4219 if (ret)
4220 btrfs_abort_transaction(trans, ret);
4221 out:
4222 btrfs_free_path(path);
4223 return ret;
4224 }
4225
4226 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4227 {
4228 struct inode *inode = d_inode(dentry);
4229 int err = 0;
4230 struct btrfs_root *root = BTRFS_I(dir)->root;
4231 struct btrfs_trans_handle *trans;
4232 u64 last_unlink_trans;
4233
4234 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4235 return -ENOTEMPTY;
4236 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
4237 return -EPERM;
4238
4239 trans = __unlink_start_trans(dir);
4240 if (IS_ERR(trans))
4241 return PTR_ERR(trans);
4242
4243 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4244 err = btrfs_unlink_subvol(trans, root, dir,
4245 BTRFS_I(inode)->location.objectid,
4246 dentry->d_name.name,
4247 dentry->d_name.len);
4248 goto out;
4249 }
4250
4251 err = btrfs_orphan_add(trans, inode);
4252 if (err)
4253 goto out;
4254
4255 last_unlink_trans = BTRFS_I(inode)->last_unlink_trans;
4256
4257 /* now the directory is empty */
4258 err = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4259 dentry->d_name.name, dentry->d_name.len);
4260 if (!err) {
4261 btrfs_i_size_write(inode, 0);
4262 /*
4263 * Propagate the last_unlink_trans value of the deleted dir to
4264 * its parent directory. This is to prevent an unrecoverable
4265 * log tree in the case we do something like this:
4266 * 1) create dir foo
4267 * 2) create snapshot under dir foo
4268 * 3) delete the snapshot
4269 * 4) rmdir foo
4270 * 5) mkdir foo
4271 * 6) fsync foo or some file inside foo
4272 */
4273 if (last_unlink_trans >= trans->transid)
4274 BTRFS_I(dir)->last_unlink_trans = last_unlink_trans;
4275 }
4276 out:
4277 btrfs_end_transaction(trans, root);
4278 btrfs_btree_balance_dirty(root);
4279
4280 return err;
4281 }
4282
4283 static int truncate_space_check(struct btrfs_trans_handle *trans,
4284 struct btrfs_root *root,
4285 u64 bytes_deleted)
4286 {
4287 int ret;
4288
4289 /*
4290 * This is only used to apply pressure to the enospc system, we don't
4291 * intend to use this reservation at all.
4292 */
4293 bytes_deleted = btrfs_csum_bytes_to_leaves(root, bytes_deleted);
4294 bytes_deleted *= root->nodesize;
4295 ret = btrfs_block_rsv_add(root, &root->fs_info->trans_block_rsv,
4296 bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
4297 if (!ret) {
4298 trace_btrfs_space_reservation(root->fs_info, "transaction",
4299 trans->transid,
4300 bytes_deleted, 1);
4301 trans->bytes_reserved += bytes_deleted;
4302 }
4303 return ret;
4304
4305 }
4306
4307 static int truncate_inline_extent(struct inode *inode,
4308 struct btrfs_path *path,
4309 struct btrfs_key *found_key,
4310 const u64 item_end,
4311 const u64 new_size)
4312 {
4313 struct extent_buffer *leaf = path->nodes[0];
4314 int slot = path->slots[0];
4315 struct btrfs_file_extent_item *fi;
4316 u32 size = (u32)(new_size - found_key->offset);
4317 struct btrfs_root *root = BTRFS_I(inode)->root;
4318
4319 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
4320
4321 if (btrfs_file_extent_compression(leaf, fi) != BTRFS_COMPRESS_NONE) {
4322 loff_t offset = new_size;
4323 loff_t page_end = ALIGN(offset, PAGE_SIZE);
4324
4325 /*
4326 * Zero out the remaining of the last page of our inline extent,
4327 * instead of directly truncating our inline extent here - that
4328 * would be much more complex (decompressing all the data, then
4329 * compressing the truncated data, which might be bigger than
4330 * the size of the inline extent, resize the extent, etc).
4331 * We release the path because to get the page we might need to
4332 * read the extent item from disk (data not in the page cache).
4333 */
4334 btrfs_release_path(path);
4335 return btrfs_truncate_block(inode, offset, page_end - offset,
4336 0);
4337 }
4338
4339 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4340 size = btrfs_file_extent_calc_inline_size(size);
4341 btrfs_truncate_item(root, path, size, 1);
4342
4343 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4344 inode_sub_bytes(inode, item_end + 1 - new_size);
4345
4346 return 0;
4347 }
4348
4349 /*
4350 * this can truncate away extent items, csum items and directory items.
4351 * It starts at a high offset and removes keys until it can't find
4352 * any higher than new_size
4353 *
4354 * csum items that cross the new i_size are truncated to the new size
4355 * as well.
4356 *
4357 * min_type is the minimum key type to truncate down to. If set to 0, this
4358 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4359 */
4360 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4361 struct btrfs_root *root,
4362 struct inode *inode,
4363 u64 new_size, u32 min_type)
4364 {
4365 struct btrfs_path *path;
4366 struct extent_buffer *leaf;
4367 struct btrfs_file_extent_item *fi;
4368 struct btrfs_key key;
4369 struct btrfs_key found_key;
4370 u64 extent_start = 0;
4371 u64 extent_num_bytes = 0;
4372 u64 extent_offset = 0;
4373 u64 item_end = 0;
4374 u64 last_size = new_size;
4375 u32 found_type = (u8)-1;
4376 int found_extent;
4377 int del_item;
4378 int pending_del_nr = 0;
4379 int pending_del_slot = 0;
4380 int extent_type = -1;
4381 int ret;
4382 int err = 0;
4383 u64 ino = btrfs_ino(inode);
4384 u64 bytes_deleted = 0;
4385 bool be_nice = 0;
4386 bool should_throttle = 0;
4387 bool should_end = 0;
4388
4389 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4390
4391 /*
4392 * for non-free space inodes and ref cows, we want to back off from
4393 * time to time
4394 */
4395 if (!btrfs_is_free_space_inode(inode) &&
4396 test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4397 be_nice = 1;
4398
4399 path = btrfs_alloc_path();
4400 if (!path)
4401 return -ENOMEM;
4402 path->reada = READA_BACK;
4403
4404 /*
4405 * We want to drop from the next block forward in case this new size is
4406 * not block aligned since we will be keeping the last block of the
4407 * extent just the way it is.
4408 */
4409 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4410 root == root->fs_info->tree_root)
4411 btrfs_drop_extent_cache(inode, ALIGN(new_size,
4412 root->sectorsize), (u64)-1, 0);
4413
4414 /*
4415 * This function is also used to drop the items in the log tree before
4416 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4417 * it is used to drop the loged items. So we shouldn't kill the delayed
4418 * items.
4419 */
4420 if (min_type == 0 && root == BTRFS_I(inode)->root)
4421 btrfs_kill_delayed_inode_items(inode);
4422
4423 key.objectid = ino;
4424 key.offset = (u64)-1;
4425 key.type = (u8)-1;
4426
4427 search_again:
4428 /*
4429 * with a 16K leaf size and 128MB extents, you can actually queue
4430 * up a huge file in a single leaf. Most of the time that
4431 * bytes_deleted is > 0, it will be huge by the time we get here
4432 */
4433 if (be_nice && bytes_deleted > SZ_32M) {
4434 if (btrfs_should_end_transaction(trans, root)) {
4435 err = -EAGAIN;
4436 goto error;
4437 }
4438 }
4439
4440
4441 path->leave_spinning = 1;
4442 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4443 if (ret < 0) {
4444 err = ret;
4445 goto out;
4446 }
4447
4448 if (ret > 0) {
4449 /* there are no items in the tree for us to truncate, we're
4450 * done
4451 */
4452 if (path->slots[0] == 0)
4453 goto out;
4454 path->slots[0]--;
4455 }
4456
4457 while (1) {
4458 fi = NULL;
4459 leaf = path->nodes[0];
4460 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4461 found_type = found_key.type;
4462
4463 if (found_key.objectid != ino)
4464 break;
4465
4466 if (found_type < min_type)
4467 break;
4468
4469 item_end = found_key.offset;
4470 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4471 fi = btrfs_item_ptr(leaf, path->slots[0],
4472 struct btrfs_file_extent_item);
4473 extent_type = btrfs_file_extent_type(leaf, fi);
4474 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4475 item_end +=
4476 btrfs_file_extent_num_bytes(leaf, fi);
4477 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4478 item_end += btrfs_file_extent_inline_len(leaf,
4479 path->slots[0], fi);
4480 }
4481 item_end--;
4482 }
4483 if (found_type > min_type) {
4484 del_item = 1;
4485 } else {
4486 if (item_end < new_size)
4487 break;
4488 if (found_key.offset >= new_size)
4489 del_item = 1;
4490 else
4491 del_item = 0;
4492 }
4493 found_extent = 0;
4494 /* FIXME, shrink the extent if the ref count is only 1 */
4495 if (found_type != BTRFS_EXTENT_DATA_KEY)
4496 goto delete;
4497
4498 if (del_item)
4499 last_size = found_key.offset;
4500 else
4501 last_size = new_size;
4502
4503 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4504 u64 num_dec;
4505 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4506 if (!del_item) {
4507 u64 orig_num_bytes =
4508 btrfs_file_extent_num_bytes(leaf, fi);
4509 extent_num_bytes = ALIGN(new_size -
4510 found_key.offset,
4511 root->sectorsize);
4512 btrfs_set_file_extent_num_bytes(leaf, fi,
4513 extent_num_bytes);
4514 num_dec = (orig_num_bytes -
4515 extent_num_bytes);
4516 if (test_bit(BTRFS_ROOT_REF_COWS,
4517 &root->state) &&
4518 extent_start != 0)
4519 inode_sub_bytes(inode, num_dec);
4520 btrfs_mark_buffer_dirty(leaf);
4521 } else {
4522 extent_num_bytes =
4523 btrfs_file_extent_disk_num_bytes(leaf,
4524 fi);
4525 extent_offset = found_key.offset -
4526 btrfs_file_extent_offset(leaf, fi);
4527
4528 /* FIXME blocksize != 4096 */
4529 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4530 if (extent_start != 0) {
4531 found_extent = 1;
4532 if (test_bit(BTRFS_ROOT_REF_COWS,
4533 &root->state))
4534 inode_sub_bytes(inode, num_dec);
4535 }
4536 }
4537 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4538 /*
4539 * we can't truncate inline items that have had
4540 * special encodings
4541 */
4542 if (!del_item &&
4543 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4544 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4545
4546 /*
4547 * Need to release path in order to truncate a
4548 * compressed extent. So delete any accumulated
4549 * extent items so far.
4550 */
4551 if (btrfs_file_extent_compression(leaf, fi) !=
4552 BTRFS_COMPRESS_NONE && pending_del_nr) {
4553 err = btrfs_del_items(trans, root, path,
4554 pending_del_slot,
4555 pending_del_nr);
4556 if (err) {
4557 btrfs_abort_transaction(trans,
4558 err);
4559 goto error;
4560 }
4561 pending_del_nr = 0;
4562 }
4563
4564 err = truncate_inline_extent(inode, path,
4565 &found_key,
4566 item_end,
4567 new_size);
4568 if (err) {
4569 btrfs_abort_transaction(trans, err);
4570 goto error;
4571 }
4572 } else if (test_bit(BTRFS_ROOT_REF_COWS,
4573 &root->state)) {
4574 inode_sub_bytes(inode, item_end + 1 - new_size);
4575 }
4576 }
4577 delete:
4578 if (del_item) {
4579 if (!pending_del_nr) {
4580 /* no pending yet, add ourselves */
4581 pending_del_slot = path->slots[0];
4582 pending_del_nr = 1;
4583 } else if (pending_del_nr &&
4584 path->slots[0] + 1 == pending_del_slot) {
4585 /* hop on the pending chunk */
4586 pending_del_nr++;
4587 pending_del_slot = path->slots[0];
4588 } else {
4589 BUG();
4590 }
4591 } else {
4592 break;
4593 }
4594 should_throttle = 0;
4595
4596 if (found_extent &&
4597 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4598 root == root->fs_info->tree_root)) {
4599 btrfs_set_path_blocking(path);
4600 bytes_deleted += extent_num_bytes;
4601 ret = btrfs_free_extent(trans, root, extent_start,
4602 extent_num_bytes, 0,
4603 btrfs_header_owner(leaf),
4604 ino, extent_offset);
4605 BUG_ON(ret);
4606 if (btrfs_should_throttle_delayed_refs(trans, root))
4607 btrfs_async_run_delayed_refs(root,
4608 trans->delayed_ref_updates * 2,
4609 trans->transid, 0);
4610 if (be_nice) {
4611 if (truncate_space_check(trans, root,
4612 extent_num_bytes)) {
4613 should_end = 1;
4614 }
4615 if (btrfs_should_throttle_delayed_refs(trans,
4616 root)) {
4617 should_throttle = 1;
4618 }
4619 }
4620 }
4621
4622 if (found_type == BTRFS_INODE_ITEM_KEY)
4623 break;
4624
4625 if (path->slots[0] == 0 ||
4626 path->slots[0] != pending_del_slot ||
4627 should_throttle || should_end) {
4628 if (pending_del_nr) {
4629 ret = btrfs_del_items(trans, root, path,
4630 pending_del_slot,
4631 pending_del_nr);
4632 if (ret) {
4633 btrfs_abort_transaction(trans, ret);
4634 goto error;
4635 }
4636 pending_del_nr = 0;
4637 }
4638 btrfs_release_path(path);
4639 if (should_throttle) {
4640 unsigned long updates = trans->delayed_ref_updates;
4641 if (updates) {
4642 trans->delayed_ref_updates = 0;
4643 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4644 if (ret && !err)
4645 err = ret;
4646 }
4647 }
4648 /*
4649 * if we failed to refill our space rsv, bail out
4650 * and let the transaction restart
4651 */
4652 if (should_end) {
4653 err = -EAGAIN;
4654 goto error;
4655 }
4656 goto search_again;
4657 } else {
4658 path->slots[0]--;
4659 }
4660 }
4661 out:
4662 if (pending_del_nr) {
4663 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4664 pending_del_nr);
4665 if (ret)
4666 btrfs_abort_transaction(trans, ret);
4667 }
4668 error:
4669 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
4670 btrfs_ordered_update_i_size(inode, last_size, NULL);
4671
4672 btrfs_free_path(path);
4673
4674 if (be_nice && bytes_deleted > SZ_32M) {
4675 unsigned long updates = trans->delayed_ref_updates;
4676 if (updates) {
4677 trans->delayed_ref_updates = 0;
4678 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4679 if (ret && !err)
4680 err = ret;
4681 }
4682 }
4683 return err;
4684 }
4685
4686 /*
4687 * btrfs_truncate_block - read, zero a chunk and write a block
4688 * @inode - inode that we're zeroing
4689 * @from - the offset to start zeroing
4690 * @len - the length to zero, 0 to zero the entire range respective to the
4691 * offset
4692 * @front - zero up to the offset instead of from the offset on
4693 *
4694 * This will find the block for the "from" offset and cow the block and zero the
4695 * part we want to zero. This is used with truncate and hole punching.
4696 */
4697 int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
4698 int front)
4699 {
4700 struct address_space *mapping = inode->i_mapping;
4701 struct btrfs_root *root = BTRFS_I(inode)->root;
4702 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4703 struct btrfs_ordered_extent *ordered;
4704 struct extent_state *cached_state = NULL;
4705 char *kaddr;
4706 u32 blocksize = root->sectorsize;
4707 pgoff_t index = from >> PAGE_SHIFT;
4708 unsigned offset = from & (blocksize - 1);
4709 struct page *page;
4710 gfp_t mask = btrfs_alloc_write_mask(mapping);
4711 int ret = 0;
4712 u64 block_start;
4713 u64 block_end;
4714
4715 if ((offset & (blocksize - 1)) == 0 &&
4716 (!len || ((len & (blocksize - 1)) == 0)))
4717 goto out;
4718
4719 ret = btrfs_delalloc_reserve_space(inode,
4720 round_down(from, blocksize), blocksize);
4721 if (ret)
4722 goto out;
4723
4724 again:
4725 page = find_or_create_page(mapping, index, mask);
4726 if (!page) {
4727 btrfs_delalloc_release_space(inode,
4728 round_down(from, blocksize),
4729 blocksize);
4730 ret = -ENOMEM;
4731 goto out;
4732 }
4733
4734 block_start = round_down(from, blocksize);
4735 block_end = block_start + blocksize - 1;
4736
4737 if (!PageUptodate(page)) {
4738 ret = btrfs_readpage(NULL, page);
4739 lock_page(page);
4740 if (page->mapping != mapping) {
4741 unlock_page(page);
4742 put_page(page);
4743 goto again;
4744 }
4745 if (!PageUptodate(page)) {
4746 ret = -EIO;
4747 goto out_unlock;
4748 }
4749 }
4750 wait_on_page_writeback(page);
4751
4752 lock_extent_bits(io_tree, block_start, block_end, &cached_state);
4753 set_page_extent_mapped(page);
4754
4755 ordered = btrfs_lookup_ordered_extent(inode, block_start);
4756 if (ordered) {
4757 unlock_extent_cached(io_tree, block_start, block_end,
4758 &cached_state, GFP_NOFS);
4759 unlock_page(page);
4760 put_page(page);
4761 btrfs_start_ordered_extent(inode, ordered, 1);
4762 btrfs_put_ordered_extent(ordered);
4763 goto again;
4764 }
4765
4766 clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end,
4767 EXTENT_DIRTY | EXTENT_DELALLOC |
4768 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4769 0, 0, &cached_state, GFP_NOFS);
4770
4771 ret = btrfs_set_extent_delalloc(inode, block_start, block_end,
4772 &cached_state, 0);
4773 if (ret) {
4774 unlock_extent_cached(io_tree, block_start, block_end,
4775 &cached_state, GFP_NOFS);
4776 goto out_unlock;
4777 }
4778
4779 if (offset != blocksize) {
4780 if (!len)
4781 len = blocksize - offset;
4782 kaddr = kmap(page);
4783 if (front)
4784 memset(kaddr + (block_start - page_offset(page)),
4785 0, offset);
4786 else
4787 memset(kaddr + (block_start - page_offset(page)) + offset,
4788 0, len);
4789 flush_dcache_page(page);
4790 kunmap(page);
4791 }
4792 ClearPageChecked(page);
4793 set_page_dirty(page);
4794 unlock_extent_cached(io_tree, block_start, block_end, &cached_state,
4795 GFP_NOFS);
4796
4797 out_unlock:
4798 if (ret)
4799 btrfs_delalloc_release_space(inode, block_start,
4800 blocksize);
4801 unlock_page(page);
4802 put_page(page);
4803 out:
4804 return ret;
4805 }
4806
4807 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4808 u64 offset, u64 len)
4809 {
4810 struct btrfs_trans_handle *trans;
4811 int ret;
4812
4813 /*
4814 * Still need to make sure the inode looks like it's been updated so
4815 * that any holes get logged if we fsync.
4816 */
4817 if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) {
4818 BTRFS_I(inode)->last_trans = root->fs_info->generation;
4819 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4820 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4821 return 0;
4822 }
4823
4824 /*
4825 * 1 - for the one we're dropping
4826 * 1 - for the one we're adding
4827 * 1 - for updating the inode.
4828 */
4829 trans = btrfs_start_transaction(root, 3);
4830 if (IS_ERR(trans))
4831 return PTR_ERR(trans);
4832
4833 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4834 if (ret) {
4835 btrfs_abort_transaction(trans, ret);
4836 btrfs_end_transaction(trans, root);
4837 return ret;
4838 }
4839
4840 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
4841 0, 0, len, 0, len, 0, 0, 0);
4842 if (ret)
4843 btrfs_abort_transaction(trans, ret);
4844 else
4845 btrfs_update_inode(trans, root, inode);
4846 btrfs_end_transaction(trans, root);
4847 return ret;
4848 }
4849
4850 /*
4851 * This function puts in dummy file extents for the area we're creating a hole
4852 * for. So if we are truncating this file to a larger size we need to insert
4853 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4854 * the range between oldsize and size
4855 */
4856 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4857 {
4858 struct btrfs_root *root = BTRFS_I(inode)->root;
4859 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4860 struct extent_map *em = NULL;
4861 struct extent_state *cached_state = NULL;
4862 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4863 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4864 u64 block_end = ALIGN(size, root->sectorsize);
4865 u64 last_byte;
4866 u64 cur_offset;
4867 u64 hole_size;
4868 int err = 0;
4869
4870 /*
4871 * If our size started in the middle of a block we need to zero out the
4872 * rest of the block before we expand the i_size, otherwise we could
4873 * expose stale data.
4874 */
4875 err = btrfs_truncate_block(inode, oldsize, 0, 0);
4876 if (err)
4877 return err;
4878
4879 if (size <= hole_start)
4880 return 0;
4881
4882 while (1) {
4883 struct btrfs_ordered_extent *ordered;
4884
4885 lock_extent_bits(io_tree, hole_start, block_end - 1,
4886 &cached_state);
4887 ordered = btrfs_lookup_ordered_range(inode, hole_start,
4888 block_end - hole_start);
4889 if (!ordered)
4890 break;
4891 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4892 &cached_state, GFP_NOFS);
4893 btrfs_start_ordered_extent(inode, ordered, 1);
4894 btrfs_put_ordered_extent(ordered);
4895 }
4896
4897 cur_offset = hole_start;
4898 while (1) {
4899 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4900 block_end - cur_offset, 0);
4901 if (IS_ERR(em)) {
4902 err = PTR_ERR(em);
4903 em = NULL;
4904 break;
4905 }
4906 last_byte = min(extent_map_end(em), block_end);
4907 last_byte = ALIGN(last_byte , root->sectorsize);
4908 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4909 struct extent_map *hole_em;
4910 hole_size = last_byte - cur_offset;
4911
4912 err = maybe_insert_hole(root, inode, cur_offset,
4913 hole_size);
4914 if (err)
4915 break;
4916 btrfs_drop_extent_cache(inode, cur_offset,
4917 cur_offset + hole_size - 1, 0);
4918 hole_em = alloc_extent_map();
4919 if (!hole_em) {
4920 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4921 &BTRFS_I(inode)->runtime_flags);
4922 goto next;
4923 }
4924 hole_em->start = cur_offset;
4925 hole_em->len = hole_size;
4926 hole_em->orig_start = cur_offset;
4927
4928 hole_em->block_start = EXTENT_MAP_HOLE;
4929 hole_em->block_len = 0;
4930 hole_em->orig_block_len = 0;
4931 hole_em->ram_bytes = hole_size;
4932 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4933 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4934 hole_em->generation = root->fs_info->generation;
4935
4936 while (1) {
4937 write_lock(&em_tree->lock);
4938 err = add_extent_mapping(em_tree, hole_em, 1);
4939 write_unlock(&em_tree->lock);
4940 if (err != -EEXIST)
4941 break;
4942 btrfs_drop_extent_cache(inode, cur_offset,
4943 cur_offset +
4944 hole_size - 1, 0);
4945 }
4946 free_extent_map(hole_em);
4947 }
4948 next:
4949 free_extent_map(em);
4950 em = NULL;
4951 cur_offset = last_byte;
4952 if (cur_offset >= block_end)
4953 break;
4954 }
4955 free_extent_map(em);
4956 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4957 GFP_NOFS);
4958 return err;
4959 }
4960
4961 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4962 {
4963 struct btrfs_root *root = BTRFS_I(inode)->root;
4964 struct btrfs_trans_handle *trans;
4965 loff_t oldsize = i_size_read(inode);
4966 loff_t newsize = attr->ia_size;
4967 int mask = attr->ia_valid;
4968 int ret;
4969
4970 /*
4971 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4972 * special case where we need to update the times despite not having
4973 * these flags set. For all other operations the VFS set these flags
4974 * explicitly if it wants a timestamp update.
4975 */
4976 if (newsize != oldsize) {
4977 inode_inc_iversion(inode);
4978 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
4979 inode->i_ctime = inode->i_mtime =
4980 current_time(inode);
4981 }
4982
4983 if (newsize > oldsize) {
4984 /*
4985 * Don't do an expanding truncate while snapshoting is ongoing.
4986 * This is to ensure the snapshot captures a fully consistent
4987 * state of this file - if the snapshot captures this expanding
4988 * truncation, it must capture all writes that happened before
4989 * this truncation.
4990 */
4991 btrfs_wait_for_snapshot_creation(root);
4992 ret = btrfs_cont_expand(inode, oldsize, newsize);
4993 if (ret) {
4994 btrfs_end_write_no_snapshoting(root);
4995 return ret;
4996 }
4997
4998 trans = btrfs_start_transaction(root, 1);
4999 if (IS_ERR(trans)) {
5000 btrfs_end_write_no_snapshoting(root);
5001 return PTR_ERR(trans);
5002 }
5003
5004 i_size_write(inode, newsize);
5005 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
5006 pagecache_isize_extended(inode, oldsize, newsize);
5007 ret = btrfs_update_inode(trans, root, inode);
5008 btrfs_end_write_no_snapshoting(root);
5009 btrfs_end_transaction(trans, root);
5010 } else {
5011
5012 /*
5013 * We're truncating a file that used to have good data down to
5014 * zero. Make sure it gets into the ordered flush list so that
5015 * any new writes get down to disk quickly.
5016 */
5017 if (newsize == 0)
5018 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
5019 &BTRFS_I(inode)->runtime_flags);
5020
5021 /*
5022 * 1 for the orphan item we're going to add
5023 * 1 for the orphan item deletion.
5024 */
5025 trans = btrfs_start_transaction(root, 2);
5026 if (IS_ERR(trans))
5027 return PTR_ERR(trans);
5028
5029 /*
5030 * We need to do this in case we fail at _any_ point during the
5031 * actual truncate. Once we do the truncate_setsize we could
5032 * invalidate pages which forces any outstanding ordered io to
5033 * be instantly completed which will give us extents that need
5034 * to be truncated. If we fail to get an orphan inode down we
5035 * could have left over extents that were never meant to live,
5036 * so we need to guarantee from this point on that everything
5037 * will be consistent.
5038 */
5039 ret = btrfs_orphan_add(trans, inode);
5040 btrfs_end_transaction(trans, root);
5041 if (ret)
5042 return ret;
5043
5044 /* we don't support swapfiles, so vmtruncate shouldn't fail */
5045 truncate_setsize(inode, newsize);
5046
5047 /* Disable nonlocked read DIO to avoid the end less truncate */
5048 btrfs_inode_block_unlocked_dio(inode);
5049 inode_dio_wait(inode);
5050 btrfs_inode_resume_unlocked_dio(inode);
5051
5052 ret = btrfs_truncate(inode);
5053 if (ret && inode->i_nlink) {
5054 int err;
5055
5056 /*
5057 * failed to truncate, disk_i_size is only adjusted down
5058 * as we remove extents, so it should represent the true
5059 * size of the inode, so reset the in memory size and
5060 * delete our orphan entry.
5061 */
5062 trans = btrfs_join_transaction(root);
5063 if (IS_ERR(trans)) {
5064 btrfs_orphan_del(NULL, inode);
5065 return ret;
5066 }
5067 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
5068 err = btrfs_orphan_del(trans, inode);
5069 if (err)
5070 btrfs_abort_transaction(trans, err);
5071 btrfs_end_transaction(trans, root);
5072 }
5073 }
5074
5075 return ret;
5076 }
5077
5078 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
5079 {
5080 struct inode *inode = d_inode(dentry);
5081 struct btrfs_root *root = BTRFS_I(inode)->root;
5082 int err;
5083
5084 if (btrfs_root_readonly(root))
5085 return -EROFS;
5086
5087 err = setattr_prepare(dentry, attr);
5088 if (err)
5089 return err;
5090
5091 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
5092 err = btrfs_setsize(inode, attr);
5093 if (err)
5094 return err;
5095 }
5096
5097 if (attr->ia_valid) {
5098 setattr_copy(inode, attr);
5099 inode_inc_iversion(inode);
5100 err = btrfs_dirty_inode(inode);
5101
5102 if (!err && attr->ia_valid & ATTR_MODE)
5103 err = posix_acl_chmod(inode, inode->i_mode);
5104 }
5105
5106 return err;
5107 }
5108
5109 /*
5110 * While truncating the inode pages during eviction, we get the VFS calling
5111 * btrfs_invalidatepage() against each page of the inode. This is slow because
5112 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
5113 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
5114 * extent_state structures over and over, wasting lots of time.
5115 *
5116 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
5117 * those expensive operations on a per page basis and do only the ordered io
5118 * finishing, while we release here the extent_map and extent_state structures,
5119 * without the excessive merging and splitting.
5120 */
5121 static void evict_inode_truncate_pages(struct inode *inode)
5122 {
5123 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5124 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
5125 struct rb_node *node;
5126
5127 ASSERT(inode->i_state & I_FREEING);
5128 truncate_inode_pages_final(&inode->i_data);
5129
5130 write_lock(&map_tree->lock);
5131 while (!RB_EMPTY_ROOT(&map_tree->map)) {
5132 struct extent_map *em;
5133
5134 node = rb_first(&map_tree->map);
5135 em = rb_entry(node, struct extent_map, rb_node);
5136 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
5137 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
5138 remove_extent_mapping(map_tree, em);
5139 free_extent_map(em);
5140 if (need_resched()) {
5141 write_unlock(&map_tree->lock);
5142 cond_resched();
5143 write_lock(&map_tree->lock);
5144 }
5145 }
5146 write_unlock(&map_tree->lock);
5147
5148 /*
5149 * Keep looping until we have no more ranges in the io tree.
5150 * We can have ongoing bios started by readpages (called from readahead)
5151 * that have their endio callback (extent_io.c:end_bio_extent_readpage)
5152 * still in progress (unlocked the pages in the bio but did not yet
5153 * unlocked the ranges in the io tree). Therefore this means some
5154 * ranges can still be locked and eviction started because before
5155 * submitting those bios, which are executed by a separate task (work
5156 * queue kthread), inode references (inode->i_count) were not taken
5157 * (which would be dropped in the end io callback of each bio).
5158 * Therefore here we effectively end up waiting for those bios and
5159 * anyone else holding locked ranges without having bumped the inode's
5160 * reference count - if we don't do it, when they access the inode's
5161 * io_tree to unlock a range it may be too late, leading to an
5162 * use-after-free issue.
5163 */
5164 spin_lock(&io_tree->lock);
5165 while (!RB_EMPTY_ROOT(&io_tree->state)) {
5166 struct extent_state *state;
5167 struct extent_state *cached_state = NULL;
5168 u64 start;
5169 u64 end;
5170
5171 node = rb_first(&io_tree->state);
5172 state = rb_entry(node, struct extent_state, rb_node);
5173 start = state->start;
5174 end = state->end;
5175 spin_unlock(&io_tree->lock);
5176
5177 lock_extent_bits(io_tree, start, end, &cached_state);
5178
5179 /*
5180 * If still has DELALLOC flag, the extent didn't reach disk,
5181 * and its reserved space won't be freed by delayed_ref.
5182 * So we need to free its reserved space here.
5183 * (Refer to comment in btrfs_invalidatepage, case 2)
5184 *
5185 * Note, end is the bytenr of last byte, so we need + 1 here.
5186 */
5187 if (state->state & EXTENT_DELALLOC)
5188 btrfs_qgroup_free_data(inode, start, end - start + 1);
5189
5190 clear_extent_bit(io_tree, start, end,
5191 EXTENT_LOCKED | EXTENT_DIRTY |
5192 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
5193 EXTENT_DEFRAG, 1, 1,
5194 &cached_state, GFP_NOFS);
5195
5196 cond_resched();
5197 spin_lock(&io_tree->lock);
5198 }
5199 spin_unlock(&io_tree->lock);
5200 }
5201
5202 void btrfs_evict_inode(struct inode *inode)
5203 {
5204 struct btrfs_trans_handle *trans;
5205 struct btrfs_root *root = BTRFS_I(inode)->root;
5206 struct btrfs_block_rsv *rsv, *global_rsv;
5207 int steal_from_global = 0;
5208 u64 min_size;
5209 int ret;
5210
5211 trace_btrfs_inode_evict(inode);
5212
5213 if (!root) {
5214 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
5215 return;
5216 }
5217
5218 min_size = btrfs_calc_trunc_metadata_size(root, 1);
5219
5220 evict_inode_truncate_pages(inode);
5221
5222 if (inode->i_nlink &&
5223 ((btrfs_root_refs(&root->root_item) != 0 &&
5224 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5225 btrfs_is_free_space_inode(inode)))
5226 goto no_delete;
5227
5228 if (is_bad_inode(inode)) {
5229 btrfs_orphan_del(NULL, inode);
5230 goto no_delete;
5231 }
5232 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
5233 if (!special_file(inode->i_mode))
5234 btrfs_wait_ordered_range(inode, 0, (u64)-1);
5235
5236 btrfs_free_io_failure_record(inode, 0, (u64)-1);
5237
5238 if (test_bit(BTRFS_FS_LOG_RECOVERING, &root->fs_info->flags)) {
5239 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
5240 &BTRFS_I(inode)->runtime_flags));
5241 goto no_delete;
5242 }
5243
5244 if (inode->i_nlink > 0) {
5245 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5246 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5247 goto no_delete;
5248 }
5249
5250 ret = btrfs_commit_inode_delayed_inode(inode);
5251 if (ret) {
5252 btrfs_orphan_del(NULL, inode);
5253 goto no_delete;
5254 }
5255
5256 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
5257 if (!rsv) {
5258 btrfs_orphan_del(NULL, inode);
5259 goto no_delete;
5260 }
5261 rsv->size = min_size;
5262 rsv->failfast = 1;
5263 global_rsv = &root->fs_info->global_block_rsv;
5264
5265 btrfs_i_size_write(inode, 0);
5266
5267 /*
5268 * This is a bit simpler than btrfs_truncate since we've already
5269 * reserved our space for our orphan item in the unlink, so we just
5270 * need to reserve some slack space in case we add bytes and update
5271 * inode item when doing the truncate.
5272 */
5273 while (1) {
5274 ret = btrfs_block_rsv_refill(root, rsv, min_size,
5275 BTRFS_RESERVE_FLUSH_LIMIT);
5276
5277 /*
5278 * Try and steal from the global reserve since we will
5279 * likely not use this space anyway, we want to try as
5280 * hard as possible to get this to work.
5281 */
5282 if (ret)
5283 steal_from_global++;
5284 else
5285 steal_from_global = 0;
5286 ret = 0;
5287
5288 /*
5289 * steal_from_global == 0: we reserved stuff, hooray!
5290 * steal_from_global == 1: we didn't reserve stuff, boo!
5291 * steal_from_global == 2: we've committed, still not a lot of
5292 * room but maybe we'll have room in the global reserve this
5293 * time.
5294 * steal_from_global == 3: abandon all hope!
5295 */
5296 if (steal_from_global > 2) {
5297 btrfs_warn(root->fs_info,
5298 "Could not get space for a delete, will truncate on mount %d",
5299 ret);
5300 btrfs_orphan_del(NULL, inode);
5301 btrfs_free_block_rsv(root, rsv);
5302 goto no_delete;
5303 }
5304
5305 trans = btrfs_join_transaction(root);
5306 if (IS_ERR(trans)) {
5307 btrfs_orphan_del(NULL, inode);
5308 btrfs_free_block_rsv(root, rsv);
5309 goto no_delete;
5310 }
5311
5312 /*
5313 * We can't just steal from the global reserve, we need to make
5314 * sure there is room to do it, if not we need to commit and try
5315 * again.
5316 */
5317 if (steal_from_global) {
5318 if (!btrfs_check_space_for_delayed_refs(trans, root))
5319 ret = btrfs_block_rsv_migrate(global_rsv, rsv,
5320 min_size, 0);
5321 else
5322 ret = -ENOSPC;
5323 }
5324
5325 /*
5326 * Couldn't steal from the global reserve, we have too much
5327 * pending stuff built up, commit the transaction and try it
5328 * again.
5329 */
5330 if (ret) {
5331 ret = btrfs_commit_transaction(trans, root);
5332 if (ret) {
5333 btrfs_orphan_del(NULL, inode);
5334 btrfs_free_block_rsv(root, rsv);
5335 goto no_delete;
5336 }
5337 continue;
5338 } else {
5339 steal_from_global = 0;
5340 }
5341
5342 trans->block_rsv = rsv;
5343
5344 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5345 if (ret != -ENOSPC && ret != -EAGAIN)
5346 break;
5347
5348 trans->block_rsv = &root->fs_info->trans_block_rsv;
5349 btrfs_end_transaction(trans, root);
5350 trans = NULL;
5351 btrfs_btree_balance_dirty(root);
5352 }
5353
5354 btrfs_free_block_rsv(root, rsv);
5355
5356 /*
5357 * Errors here aren't a big deal, it just means we leave orphan items
5358 * in the tree. They will be cleaned up on the next mount.
5359 */
5360 if (ret == 0) {
5361 trans->block_rsv = root->orphan_block_rsv;
5362 btrfs_orphan_del(trans, inode);
5363 } else {
5364 btrfs_orphan_del(NULL, inode);
5365 }
5366
5367 trans->block_rsv = &root->fs_info->trans_block_rsv;
5368 if (!(root == root->fs_info->tree_root ||
5369 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5370 btrfs_return_ino(root, btrfs_ino(inode));
5371
5372 btrfs_end_transaction(trans, root);
5373 btrfs_btree_balance_dirty(root);
5374 no_delete:
5375 btrfs_remove_delayed_node(inode);
5376 clear_inode(inode);
5377 }
5378
5379 /*
5380 * this returns the key found in the dir entry in the location pointer.
5381 * If no dir entries were found, location->objectid is 0.
5382 */
5383 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5384 struct btrfs_key *location)
5385 {
5386 const char *name = dentry->d_name.name;
5387 int namelen = dentry->d_name.len;
5388 struct btrfs_dir_item *di;
5389 struct btrfs_path *path;
5390 struct btrfs_root *root = BTRFS_I(dir)->root;
5391 int ret = 0;
5392
5393 path = btrfs_alloc_path();
5394 if (!path)
5395 return -ENOMEM;
5396
5397 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
5398 namelen, 0);
5399 if (IS_ERR(di))
5400 ret = PTR_ERR(di);
5401
5402 if (IS_ERR_OR_NULL(di))
5403 goto out_err;
5404
5405 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5406 out:
5407 btrfs_free_path(path);
5408 return ret;
5409 out_err:
5410 location->objectid = 0;
5411 goto out;
5412 }
5413
5414 /*
5415 * when we hit a tree root in a directory, the btrfs part of the inode
5416 * needs to be changed to reflect the root directory of the tree root. This
5417 * is kind of like crossing a mount point.
5418 */
5419 static int fixup_tree_root_location(struct btrfs_root *root,
5420 struct inode *dir,
5421 struct dentry *dentry,
5422 struct btrfs_key *location,
5423 struct btrfs_root **sub_root)
5424 {
5425 struct btrfs_path *path;
5426 struct btrfs_root *new_root;
5427 struct btrfs_root_ref *ref;
5428 struct extent_buffer *leaf;
5429 struct btrfs_key key;
5430 int ret;
5431 int err = 0;
5432
5433 path = btrfs_alloc_path();
5434 if (!path) {
5435 err = -ENOMEM;
5436 goto out;
5437 }
5438
5439 err = -ENOENT;
5440 key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5441 key.type = BTRFS_ROOT_REF_KEY;
5442 key.offset = location->objectid;
5443
5444 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, path,
5445 0, 0);
5446 if (ret) {
5447 if (ret < 0)
5448 err = ret;
5449 goto out;
5450 }
5451
5452 leaf = path->nodes[0];
5453 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5454 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
5455 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5456 goto out;
5457
5458 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5459 (unsigned long)(ref + 1),
5460 dentry->d_name.len);
5461 if (ret)
5462 goto out;
5463
5464 btrfs_release_path(path);
5465
5466 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
5467 if (IS_ERR(new_root)) {
5468 err = PTR_ERR(new_root);
5469 goto out;
5470 }
5471
5472 *sub_root = new_root;
5473 location->objectid = btrfs_root_dirid(&new_root->root_item);
5474 location->type = BTRFS_INODE_ITEM_KEY;
5475 location->offset = 0;
5476 err = 0;
5477 out:
5478 btrfs_free_path(path);
5479 return err;
5480 }
5481
5482 static void inode_tree_add(struct inode *inode)
5483 {
5484 struct btrfs_root *root = BTRFS_I(inode)->root;
5485 struct btrfs_inode *entry;
5486 struct rb_node **p;
5487 struct rb_node *parent;
5488 struct rb_node *new = &BTRFS_I(inode)->rb_node;
5489 u64 ino = btrfs_ino(inode);
5490
5491 if (inode_unhashed(inode))
5492 return;
5493 parent = NULL;
5494 spin_lock(&root->inode_lock);
5495 p = &root->inode_tree.rb_node;
5496 while (*p) {
5497 parent = *p;
5498 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5499
5500 if (ino < btrfs_ino(&entry->vfs_inode))
5501 p = &parent->rb_left;
5502 else if (ino > btrfs_ino(&entry->vfs_inode))
5503 p = &parent->rb_right;
5504 else {
5505 WARN_ON(!(entry->vfs_inode.i_state &
5506 (I_WILL_FREE | I_FREEING)));
5507 rb_replace_node(parent, new, &root->inode_tree);
5508 RB_CLEAR_NODE(parent);
5509 spin_unlock(&root->inode_lock);
5510 return;
5511 }
5512 }
5513 rb_link_node(new, parent, p);
5514 rb_insert_color(new, &root->inode_tree);
5515 spin_unlock(&root->inode_lock);
5516 }
5517
5518 static void inode_tree_del(struct inode *inode)
5519 {
5520 struct btrfs_root *root = BTRFS_I(inode)->root;
5521 int empty = 0;
5522
5523 spin_lock(&root->inode_lock);
5524 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5525 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5526 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5527 empty = RB_EMPTY_ROOT(&root->inode_tree);
5528 }
5529 spin_unlock(&root->inode_lock);
5530
5531 if (empty && btrfs_root_refs(&root->root_item) == 0) {
5532 synchronize_srcu(&root->fs_info->subvol_srcu);
5533 spin_lock(&root->inode_lock);
5534 empty = RB_EMPTY_ROOT(&root->inode_tree);
5535 spin_unlock(&root->inode_lock);
5536 if (empty)
5537 btrfs_add_dead_root(root);
5538 }
5539 }
5540
5541 void btrfs_invalidate_inodes(struct btrfs_root *root)
5542 {
5543 struct rb_node *node;
5544 struct rb_node *prev;
5545 struct btrfs_inode *entry;
5546 struct inode *inode;
5547 u64 objectid = 0;
5548
5549 if (!test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
5550 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
5551
5552 spin_lock(&root->inode_lock);
5553 again:
5554 node = root->inode_tree.rb_node;
5555 prev = NULL;
5556 while (node) {
5557 prev = node;
5558 entry = rb_entry(node, struct btrfs_inode, rb_node);
5559
5560 if (objectid < btrfs_ino(&entry->vfs_inode))
5561 node = node->rb_left;
5562 else if (objectid > btrfs_ino(&entry->vfs_inode))
5563 node = node->rb_right;
5564 else
5565 break;
5566 }
5567 if (!node) {
5568 while (prev) {
5569 entry = rb_entry(prev, struct btrfs_inode, rb_node);
5570 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
5571 node = prev;
5572 break;
5573 }
5574 prev = rb_next(prev);
5575 }
5576 }
5577 while (node) {
5578 entry = rb_entry(node, struct btrfs_inode, rb_node);
5579 objectid = btrfs_ino(&entry->vfs_inode) + 1;
5580 inode = igrab(&entry->vfs_inode);
5581 if (inode) {
5582 spin_unlock(&root->inode_lock);
5583 if (atomic_read(&inode->i_count) > 1)
5584 d_prune_aliases(inode);
5585 /*
5586 * btrfs_drop_inode will have it removed from
5587 * the inode cache when its usage count
5588 * hits zero.
5589 */
5590 iput(inode);
5591 cond_resched();
5592 spin_lock(&root->inode_lock);
5593 goto again;
5594 }
5595
5596 if (cond_resched_lock(&root->inode_lock))
5597 goto again;
5598
5599 node = rb_next(node);
5600 }
5601 spin_unlock(&root->inode_lock);
5602 }
5603
5604 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5605 {
5606 struct btrfs_iget_args *args = p;
5607 inode->i_ino = args->location->objectid;
5608 memcpy(&BTRFS_I(inode)->location, args->location,
5609 sizeof(*args->location));
5610 BTRFS_I(inode)->root = args->root;
5611 return 0;
5612 }
5613
5614 static int btrfs_find_actor(struct inode *inode, void *opaque)
5615 {
5616 struct btrfs_iget_args *args = opaque;
5617 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5618 args->root == BTRFS_I(inode)->root;
5619 }
5620
5621 static struct inode *btrfs_iget_locked(struct super_block *s,
5622 struct btrfs_key *location,
5623 struct btrfs_root *root)
5624 {
5625 struct inode *inode;
5626 struct btrfs_iget_args args;
5627 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5628
5629 args.location = location;
5630 args.root = root;
5631
5632 inode = iget5_locked(s, hashval, btrfs_find_actor,
5633 btrfs_init_locked_inode,
5634 (void *)&args);
5635 return inode;
5636 }
5637
5638 /* Get an inode object given its location and corresponding root.
5639 * Returns in *is_new if the inode was read from disk
5640 */
5641 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5642 struct btrfs_root *root, int *new)
5643 {
5644 struct inode *inode;
5645
5646 inode = btrfs_iget_locked(s, location, root);
5647 if (!inode)
5648 return ERR_PTR(-ENOMEM);
5649
5650 if (inode->i_state & I_NEW) {
5651 int ret;
5652
5653 ret = btrfs_read_locked_inode(inode);
5654 if (!is_bad_inode(inode)) {
5655 inode_tree_add(inode);
5656 unlock_new_inode(inode);
5657 if (new)
5658 *new = 1;
5659 } else {
5660 unlock_new_inode(inode);
5661 iput(inode);
5662 ASSERT(ret < 0);
5663 inode = ERR_PTR(ret < 0 ? ret : -ESTALE);
5664 }
5665 }
5666
5667 return inode;
5668 }
5669
5670 static struct inode *new_simple_dir(struct super_block *s,
5671 struct btrfs_key *key,
5672 struct btrfs_root *root)
5673 {
5674 struct inode *inode = new_inode(s);
5675
5676 if (!inode)
5677 return ERR_PTR(-ENOMEM);
5678
5679 BTRFS_I(inode)->root = root;
5680 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5681 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5682
5683 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5684 inode->i_op = &btrfs_dir_ro_inode_operations;
5685 inode->i_fop = &simple_dir_operations;
5686 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5687 inode->i_mtime = current_time(inode);
5688 inode->i_atime = inode->i_mtime;
5689 inode->i_ctime = inode->i_mtime;
5690 BTRFS_I(inode)->i_otime = inode->i_mtime;
5691
5692 return inode;
5693 }
5694
5695 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5696 {
5697 struct inode *inode;
5698 struct btrfs_root *root = BTRFS_I(dir)->root;
5699 struct btrfs_root *sub_root = root;
5700 struct btrfs_key location;
5701 int index;
5702 int ret = 0;
5703
5704 if (dentry->d_name.len > BTRFS_NAME_LEN)
5705 return ERR_PTR(-ENAMETOOLONG);
5706
5707 ret = btrfs_inode_by_name(dir, dentry, &location);
5708 if (ret < 0)
5709 return ERR_PTR(ret);
5710
5711 if (location.objectid == 0)
5712 return ERR_PTR(-ENOENT);
5713
5714 if (location.type == BTRFS_INODE_ITEM_KEY) {
5715 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5716 return inode;
5717 }
5718
5719 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5720
5721 index = srcu_read_lock(&root->fs_info->subvol_srcu);
5722 ret = fixup_tree_root_location(root, dir, dentry,
5723 &location, &sub_root);
5724 if (ret < 0) {
5725 if (ret != -ENOENT)
5726 inode = ERR_PTR(ret);
5727 else
5728 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5729 } else {
5730 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5731 }
5732 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
5733
5734 if (!IS_ERR(inode) && root != sub_root) {
5735 down_read(&root->fs_info->cleanup_work_sem);
5736 if (!(inode->i_sb->s_flags & MS_RDONLY))
5737 ret = btrfs_orphan_cleanup(sub_root);
5738 up_read(&root->fs_info->cleanup_work_sem);
5739 if (ret) {
5740 iput(inode);
5741 inode = ERR_PTR(ret);
5742 }
5743 }
5744
5745 return inode;
5746 }
5747
5748 static int btrfs_dentry_delete(const struct dentry *dentry)
5749 {
5750 struct btrfs_root *root;
5751 struct inode *inode = d_inode(dentry);
5752
5753 if (!inode && !IS_ROOT(dentry))
5754 inode = d_inode(dentry->d_parent);
5755
5756 if (inode) {
5757 root = BTRFS_I(inode)->root;
5758 if (btrfs_root_refs(&root->root_item) == 0)
5759 return 1;
5760
5761 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5762 return 1;
5763 }
5764 return 0;
5765 }
5766
5767 static void btrfs_dentry_release(struct dentry *dentry)
5768 {
5769 kfree(dentry->d_fsdata);
5770 }
5771
5772 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5773 unsigned int flags)
5774 {
5775 struct inode *inode;
5776
5777 inode = btrfs_lookup_dentry(dir, dentry);
5778 if (IS_ERR(inode)) {
5779 if (PTR_ERR(inode) == -ENOENT)
5780 inode = NULL;
5781 else
5782 return ERR_CAST(inode);
5783 }
5784
5785 return d_splice_alias(inode, dentry);
5786 }
5787
5788 unsigned char btrfs_filetype_table[] = {
5789 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5790 };
5791
5792 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5793 {
5794 struct inode *inode = file_inode(file);
5795 struct btrfs_root *root = BTRFS_I(inode)->root;
5796 struct btrfs_item *item;
5797 struct btrfs_dir_item *di;
5798 struct btrfs_key key;
5799 struct btrfs_key found_key;
5800 struct btrfs_path *path;
5801 struct list_head ins_list;
5802 struct list_head del_list;
5803 int ret;
5804 struct extent_buffer *leaf;
5805 int slot;
5806 unsigned char d_type;
5807 int over = 0;
5808 u32 di_cur;
5809 u32 di_total;
5810 u32 di_len;
5811 int key_type = BTRFS_DIR_INDEX_KEY;
5812 char tmp_name[32];
5813 char *name_ptr;
5814 int name_len;
5815 int is_curr = 0; /* ctx->pos points to the current index? */
5816 bool emitted;
5817 bool put = false;
5818
5819 /* FIXME, use a real flag for deciding about the key type */
5820 if (root->fs_info->tree_root == root)
5821 key_type = BTRFS_DIR_ITEM_KEY;
5822
5823 if (!dir_emit_dots(file, ctx))
5824 return 0;
5825
5826 path = btrfs_alloc_path();
5827 if (!path)
5828 return -ENOMEM;
5829
5830 path->reada = READA_FORWARD;
5831
5832 if (key_type == BTRFS_DIR_INDEX_KEY) {
5833 INIT_LIST_HEAD(&ins_list);
5834 INIT_LIST_HEAD(&del_list);
5835 put = btrfs_readdir_get_delayed_items(inode, &ins_list,
5836 &del_list);
5837 }
5838
5839 key.type = key_type;
5840 key.offset = ctx->pos;
5841 key.objectid = btrfs_ino(inode);
5842
5843 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5844 if (ret < 0)
5845 goto err;
5846
5847 emitted = false;
5848 while (1) {
5849 leaf = path->nodes[0];
5850 slot = path->slots[0];
5851 if (slot >= btrfs_header_nritems(leaf)) {
5852 ret = btrfs_next_leaf(root, path);
5853 if (ret < 0)
5854 goto err;
5855 else if (ret > 0)
5856 break;
5857 continue;
5858 }
5859
5860 item = btrfs_item_nr(slot);
5861 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5862
5863 if (found_key.objectid != key.objectid)
5864 break;
5865 if (found_key.type != key_type)
5866 break;
5867 if (found_key.offset < ctx->pos)
5868 goto next;
5869 if (key_type == BTRFS_DIR_INDEX_KEY &&
5870 btrfs_should_delete_dir_index(&del_list,
5871 found_key.offset))
5872 goto next;
5873
5874 ctx->pos = found_key.offset;
5875 is_curr = 1;
5876
5877 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5878 di_cur = 0;
5879 di_total = btrfs_item_size(leaf, item);
5880
5881 while (di_cur < di_total) {
5882 struct btrfs_key location;
5883
5884 if (verify_dir_item(root, leaf, di))
5885 break;
5886
5887 name_len = btrfs_dir_name_len(leaf, di);
5888 if (name_len <= sizeof(tmp_name)) {
5889 name_ptr = tmp_name;
5890 } else {
5891 name_ptr = kmalloc(name_len, GFP_KERNEL);
5892 if (!name_ptr) {
5893 ret = -ENOMEM;
5894 goto err;
5895 }
5896 }
5897 read_extent_buffer(leaf, name_ptr,
5898 (unsigned long)(di + 1), name_len);
5899
5900 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5901 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5902
5903
5904 /* is this a reference to our own snapshot? If so
5905 * skip it.
5906 *
5907 * In contrast to old kernels, we insert the snapshot's
5908 * dir item and dir index after it has been created, so
5909 * we won't find a reference to our own snapshot. We
5910 * still keep the following code for backward
5911 * compatibility.
5912 */
5913 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5914 location.objectid == root->root_key.objectid) {
5915 over = 0;
5916 goto skip;
5917 }
5918 over = !dir_emit(ctx, name_ptr, name_len,
5919 location.objectid, d_type);
5920
5921 skip:
5922 if (name_ptr != tmp_name)
5923 kfree(name_ptr);
5924
5925 if (over)
5926 goto nopos;
5927 emitted = true;
5928 di_len = btrfs_dir_name_len(leaf, di) +
5929 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5930 di_cur += di_len;
5931 di = (struct btrfs_dir_item *)((char *)di + di_len);
5932 }
5933 next:
5934 path->slots[0]++;
5935 }
5936
5937 if (key_type == BTRFS_DIR_INDEX_KEY) {
5938 if (is_curr)
5939 ctx->pos++;
5940 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list, &emitted);
5941 if (ret)
5942 goto nopos;
5943 }
5944
5945 /*
5946 * If we haven't emitted any dir entry, we must not touch ctx->pos as
5947 * it was was set to the termination value in previous call. We assume
5948 * that "." and ".." were emitted if we reach this point and set the
5949 * termination value as well for an empty directory.
5950 */
5951 if (ctx->pos > 2 && !emitted)
5952 goto nopos;
5953
5954 /* Reached end of directory/root. Bump pos past the last item. */
5955 ctx->pos++;
5956
5957 /*
5958 * Stop new entries from being returned after we return the last
5959 * entry.
5960 *
5961 * New directory entries are assigned a strictly increasing
5962 * offset. This means that new entries created during readdir
5963 * are *guaranteed* to be seen in the future by that readdir.
5964 * This has broken buggy programs which operate on names as
5965 * they're returned by readdir. Until we re-use freed offsets
5966 * we have this hack to stop new entries from being returned
5967 * under the assumption that they'll never reach this huge
5968 * offset.
5969 *
5970 * This is being careful not to overflow 32bit loff_t unless the
5971 * last entry requires it because doing so has broken 32bit apps
5972 * in the past.
5973 */
5974 if (key_type == BTRFS_DIR_INDEX_KEY) {
5975 if (ctx->pos >= INT_MAX)
5976 ctx->pos = LLONG_MAX;
5977 else
5978 ctx->pos = INT_MAX;
5979 }
5980 nopos:
5981 ret = 0;
5982 err:
5983 if (put)
5984 btrfs_readdir_put_delayed_items(inode, &ins_list, &del_list);
5985 btrfs_free_path(path);
5986 return ret;
5987 }
5988
5989 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5990 {
5991 struct btrfs_root *root = BTRFS_I(inode)->root;
5992 struct btrfs_trans_handle *trans;
5993 int ret = 0;
5994 bool nolock = false;
5995
5996 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5997 return 0;
5998
5999 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
6000 nolock = true;
6001
6002 if (wbc->sync_mode == WB_SYNC_ALL) {
6003 if (nolock)
6004 trans = btrfs_join_transaction_nolock(root);
6005 else
6006 trans = btrfs_join_transaction(root);
6007 if (IS_ERR(trans))
6008 return PTR_ERR(trans);
6009 ret = btrfs_commit_transaction(trans, root);
6010 }
6011 return ret;
6012 }
6013
6014 /*
6015 * This is somewhat expensive, updating the tree every time the
6016 * inode changes. But, it is most likely to find the inode in cache.
6017 * FIXME, needs more benchmarking...there are no reasons other than performance
6018 * to keep or drop this code.
6019 */
6020 static int btrfs_dirty_inode(struct inode *inode)
6021 {
6022 struct btrfs_root *root = BTRFS_I(inode)->root;
6023 struct btrfs_trans_handle *trans;
6024 int ret;
6025
6026 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
6027 return 0;
6028
6029 trans = btrfs_join_transaction(root);
6030 if (IS_ERR(trans))
6031 return PTR_ERR(trans);
6032
6033 ret = btrfs_update_inode(trans, root, inode);
6034 if (ret && ret == -ENOSPC) {
6035 /* whoops, lets try again with the full transaction */
6036 btrfs_end_transaction(trans, root);
6037 trans = btrfs_start_transaction(root, 1);
6038 if (IS_ERR(trans))
6039 return PTR_ERR(trans);
6040
6041 ret = btrfs_update_inode(trans, root, inode);
6042 }
6043 btrfs_end_transaction(trans, root);
6044 if (BTRFS_I(inode)->delayed_node)
6045 btrfs_balance_delayed_items(root);
6046
6047 return ret;
6048 }
6049
6050 /*
6051 * This is a copy of file_update_time. We need this so we can return error on
6052 * ENOSPC for updating the inode in the case of file write and mmap writes.
6053 */
6054 static int btrfs_update_time(struct inode *inode, struct timespec *now,
6055 int flags)
6056 {
6057 struct btrfs_root *root = BTRFS_I(inode)->root;
6058
6059 if (btrfs_root_readonly(root))
6060 return -EROFS;
6061
6062 if (flags & S_VERSION)
6063 inode_inc_iversion(inode);
6064 if (flags & S_CTIME)
6065 inode->i_ctime = *now;
6066 if (flags & S_MTIME)
6067 inode->i_mtime = *now;
6068 if (flags & S_ATIME)
6069 inode->i_atime = *now;
6070 return btrfs_dirty_inode(inode);
6071 }
6072
6073 /*
6074 * find the highest existing sequence number in a directory
6075 * and then set the in-memory index_cnt variable to reflect
6076 * free sequence numbers
6077 */
6078 static int btrfs_set_inode_index_count(struct inode *inode)
6079 {
6080 struct btrfs_root *root = BTRFS_I(inode)->root;
6081 struct btrfs_key key, found_key;
6082 struct btrfs_path *path;
6083 struct extent_buffer *leaf;
6084 int ret;
6085
6086 key.objectid = btrfs_ino(inode);
6087 key.type = BTRFS_DIR_INDEX_KEY;
6088 key.offset = (u64)-1;
6089
6090 path = btrfs_alloc_path();
6091 if (!path)
6092 return -ENOMEM;
6093
6094 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6095 if (ret < 0)
6096 goto out;
6097 /* FIXME: we should be able to handle this */
6098 if (ret == 0)
6099 goto out;
6100 ret = 0;
6101
6102 /*
6103 * MAGIC NUMBER EXPLANATION:
6104 * since we search a directory based on f_pos we have to start at 2
6105 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
6106 * else has to start at 2
6107 */
6108 if (path->slots[0] == 0) {
6109 BTRFS_I(inode)->index_cnt = 2;
6110 goto out;
6111 }
6112
6113 path->slots[0]--;
6114
6115 leaf = path->nodes[0];
6116 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6117
6118 if (found_key.objectid != btrfs_ino(inode) ||
6119 found_key.type != BTRFS_DIR_INDEX_KEY) {
6120 BTRFS_I(inode)->index_cnt = 2;
6121 goto out;
6122 }
6123
6124 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
6125 out:
6126 btrfs_free_path(path);
6127 return ret;
6128 }
6129
6130 /*
6131 * helper to find a free sequence number in a given directory. This current
6132 * code is very simple, later versions will do smarter things in the btree
6133 */
6134 int btrfs_set_inode_index(struct inode *dir, u64 *index)
6135 {
6136 int ret = 0;
6137
6138 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
6139 ret = btrfs_inode_delayed_dir_index_count(dir);
6140 if (ret) {
6141 ret = btrfs_set_inode_index_count(dir);
6142 if (ret)
6143 return ret;
6144 }
6145 }
6146
6147 *index = BTRFS_I(dir)->index_cnt;
6148 BTRFS_I(dir)->index_cnt++;
6149
6150 return ret;
6151 }
6152
6153 static int btrfs_insert_inode_locked(struct inode *inode)
6154 {
6155 struct btrfs_iget_args args;
6156 args.location = &BTRFS_I(inode)->location;
6157 args.root = BTRFS_I(inode)->root;
6158
6159 return insert_inode_locked4(inode,
6160 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
6161 btrfs_find_actor, &args);
6162 }
6163
6164 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
6165 struct btrfs_root *root,
6166 struct inode *dir,
6167 const char *name, int name_len,
6168 u64 ref_objectid, u64 objectid,
6169 umode_t mode, u64 *index)
6170 {
6171 struct inode *inode;
6172 struct btrfs_inode_item *inode_item;
6173 struct btrfs_key *location;
6174 struct btrfs_path *path;
6175 struct btrfs_inode_ref *ref;
6176 struct btrfs_key key[2];
6177 u32 sizes[2];
6178 int nitems = name ? 2 : 1;
6179 unsigned long ptr;
6180 int ret;
6181
6182 path = btrfs_alloc_path();
6183 if (!path)
6184 return ERR_PTR(-ENOMEM);
6185
6186 inode = new_inode(root->fs_info->sb);
6187 if (!inode) {
6188 btrfs_free_path(path);
6189 return ERR_PTR(-ENOMEM);
6190 }
6191
6192 /*
6193 * O_TMPFILE, set link count to 0, so that after this point,
6194 * we fill in an inode item with the correct link count.
6195 */
6196 if (!name)
6197 set_nlink(inode, 0);
6198
6199 /*
6200 * we have to initialize this early, so we can reclaim the inode
6201 * number if we fail afterwards in this function.
6202 */
6203 inode->i_ino = objectid;
6204
6205 if (dir && name) {
6206 trace_btrfs_inode_request(dir);
6207
6208 ret = btrfs_set_inode_index(dir, index);
6209 if (ret) {
6210 btrfs_free_path(path);
6211 iput(inode);
6212 return ERR_PTR(ret);
6213 }
6214 } else if (dir) {
6215 *index = 0;
6216 }
6217 /*
6218 * index_cnt is ignored for everything but a dir,
6219 * btrfs_get_inode_index_count has an explanation for the magic
6220 * number
6221 */
6222 BTRFS_I(inode)->index_cnt = 2;
6223 BTRFS_I(inode)->dir_index = *index;
6224 BTRFS_I(inode)->root = root;
6225 BTRFS_I(inode)->generation = trans->transid;
6226 inode->i_generation = BTRFS_I(inode)->generation;
6227
6228 /*
6229 * We could have gotten an inode number from somebody who was fsynced
6230 * and then removed in this same transaction, so let's just set full
6231 * sync since it will be a full sync anyway and this will blow away the
6232 * old info in the log.
6233 */
6234 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6235
6236 key[0].objectid = objectid;
6237 key[0].type = BTRFS_INODE_ITEM_KEY;
6238 key[0].offset = 0;
6239
6240 sizes[0] = sizeof(struct btrfs_inode_item);
6241
6242 if (name) {
6243 /*
6244 * Start new inodes with an inode_ref. This is slightly more
6245 * efficient for small numbers of hard links since they will
6246 * be packed into one item. Extended refs will kick in if we
6247 * add more hard links than can fit in the ref item.
6248 */
6249 key[1].objectid = objectid;
6250 key[1].type = BTRFS_INODE_REF_KEY;
6251 key[1].offset = ref_objectid;
6252
6253 sizes[1] = name_len + sizeof(*ref);
6254 }
6255
6256 location = &BTRFS_I(inode)->location;
6257 location->objectid = objectid;
6258 location->offset = 0;
6259 location->type = BTRFS_INODE_ITEM_KEY;
6260
6261 ret = btrfs_insert_inode_locked(inode);
6262 if (ret < 0)
6263 goto fail;
6264
6265 path->leave_spinning = 1;
6266 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6267 if (ret != 0)
6268 goto fail_unlock;
6269
6270 inode_init_owner(inode, dir, mode);
6271 inode_set_bytes(inode, 0);
6272
6273 inode->i_mtime = current_time(inode);
6274 inode->i_atime = inode->i_mtime;
6275 inode->i_ctime = inode->i_mtime;
6276 BTRFS_I(inode)->i_otime = inode->i_mtime;
6277
6278 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6279 struct btrfs_inode_item);
6280 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
6281 sizeof(*inode_item));
6282 fill_inode_item(trans, path->nodes[0], inode_item, inode);
6283
6284 if (name) {
6285 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6286 struct btrfs_inode_ref);
6287 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6288 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6289 ptr = (unsigned long)(ref + 1);
6290 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6291 }
6292
6293 btrfs_mark_buffer_dirty(path->nodes[0]);
6294 btrfs_free_path(path);
6295
6296 btrfs_inherit_iflags(inode, dir);
6297
6298 if (S_ISREG(mode)) {
6299 if (btrfs_test_opt(root->fs_info, NODATASUM))
6300 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6301 if (btrfs_test_opt(root->fs_info, NODATACOW))
6302 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6303 BTRFS_INODE_NODATASUM;
6304 }
6305
6306 inode_tree_add(inode);
6307
6308 trace_btrfs_inode_new(inode);
6309 btrfs_set_inode_last_trans(trans, inode);
6310
6311 btrfs_update_root_times(trans, root);
6312
6313 ret = btrfs_inode_inherit_props(trans, inode, dir);
6314 if (ret)
6315 btrfs_err(root->fs_info,
6316 "error inheriting props for ino %llu (root %llu): %d",
6317 btrfs_ino(inode), root->root_key.objectid, ret);
6318
6319 return inode;
6320
6321 fail_unlock:
6322 unlock_new_inode(inode);
6323 fail:
6324 if (dir && name)
6325 BTRFS_I(dir)->index_cnt--;
6326 btrfs_free_path(path);
6327 iput(inode);
6328 return ERR_PTR(ret);
6329 }
6330
6331 static inline u8 btrfs_inode_type(struct inode *inode)
6332 {
6333 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
6334 }
6335
6336 /*
6337 * utility function to add 'inode' into 'parent_inode' with
6338 * a give name and a given sequence number.
6339 * if 'add_backref' is true, also insert a backref from the
6340 * inode to the parent directory.
6341 */
6342 int btrfs_add_link(struct btrfs_trans_handle *trans,
6343 struct inode *parent_inode, struct inode *inode,
6344 const char *name, int name_len, int add_backref, u64 index)
6345 {
6346 int ret = 0;
6347 struct btrfs_key key;
6348 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
6349 u64 ino = btrfs_ino(inode);
6350 u64 parent_ino = btrfs_ino(parent_inode);
6351
6352 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6353 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
6354 } else {
6355 key.objectid = ino;
6356 key.type = BTRFS_INODE_ITEM_KEY;
6357 key.offset = 0;
6358 }
6359
6360 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6361 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
6362 key.objectid, root->root_key.objectid,
6363 parent_ino, index, name, name_len);
6364 } else if (add_backref) {
6365 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6366 parent_ino, index);
6367 }
6368
6369 /* Nothing to clean up yet */
6370 if (ret)
6371 return ret;
6372
6373 ret = btrfs_insert_dir_item(trans, root, name, name_len,
6374 parent_inode, &key,
6375 btrfs_inode_type(inode), index);
6376 if (ret == -EEXIST || ret == -EOVERFLOW)
6377 goto fail_dir_item;
6378 else if (ret) {
6379 btrfs_abort_transaction(trans, ret);
6380 return ret;
6381 }
6382
6383 btrfs_i_size_write(parent_inode, parent_inode->i_size +
6384 name_len * 2);
6385 inode_inc_iversion(parent_inode);
6386 parent_inode->i_mtime = parent_inode->i_ctime =
6387 current_time(parent_inode);
6388 ret = btrfs_update_inode(trans, root, parent_inode);
6389 if (ret)
6390 btrfs_abort_transaction(trans, ret);
6391 return ret;
6392
6393 fail_dir_item:
6394 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6395 u64 local_index;
6396 int err;
6397 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
6398 key.objectid, root->root_key.objectid,
6399 parent_ino, &local_index, name, name_len);
6400
6401 } else if (add_backref) {
6402 u64 local_index;
6403 int err;
6404
6405 err = btrfs_del_inode_ref(trans, root, name, name_len,
6406 ino, parent_ino, &local_index);
6407 }
6408 return ret;
6409 }
6410
6411 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6412 struct inode *dir, struct dentry *dentry,
6413 struct inode *inode, int backref, u64 index)
6414 {
6415 int err = btrfs_add_link(trans, dir, inode,
6416 dentry->d_name.name, dentry->d_name.len,
6417 backref, index);
6418 if (err > 0)
6419 err = -EEXIST;
6420 return err;
6421 }
6422
6423 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6424 umode_t mode, dev_t rdev)
6425 {
6426 struct btrfs_trans_handle *trans;
6427 struct btrfs_root *root = BTRFS_I(dir)->root;
6428 struct inode *inode = NULL;
6429 int err;
6430 int drop_inode = 0;
6431 u64 objectid;
6432 u64 index = 0;
6433
6434 /*
6435 * 2 for inode item and ref
6436 * 2 for dir items
6437 * 1 for xattr if selinux is on
6438 */
6439 trans = btrfs_start_transaction(root, 5);
6440 if (IS_ERR(trans))
6441 return PTR_ERR(trans);
6442
6443 err = btrfs_find_free_ino(root, &objectid);
6444 if (err)
6445 goto out_unlock;
6446
6447 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6448 dentry->d_name.len, btrfs_ino(dir), objectid,
6449 mode, &index);
6450 if (IS_ERR(inode)) {
6451 err = PTR_ERR(inode);
6452 goto out_unlock;
6453 }
6454
6455 /*
6456 * If the active LSM wants to access the inode during
6457 * d_instantiate it needs these. Smack checks to see
6458 * if the filesystem supports xattrs by looking at the
6459 * ops vector.
6460 */
6461 inode->i_op = &btrfs_special_inode_operations;
6462 init_special_inode(inode, inode->i_mode, rdev);
6463
6464 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6465 if (err)
6466 goto out_unlock_inode;
6467
6468 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6469 if (err) {
6470 goto out_unlock_inode;
6471 } else {
6472 btrfs_update_inode(trans, root, inode);
6473 unlock_new_inode(inode);
6474 d_instantiate(dentry, inode);
6475 }
6476
6477 out_unlock:
6478 btrfs_end_transaction(trans, root);
6479 btrfs_balance_delayed_items(root);
6480 btrfs_btree_balance_dirty(root);
6481 if (drop_inode) {
6482 inode_dec_link_count(inode);
6483 iput(inode);
6484 }
6485 return err;
6486
6487 out_unlock_inode:
6488 drop_inode = 1;
6489 unlock_new_inode(inode);
6490 goto out_unlock;
6491
6492 }
6493
6494 static int btrfs_create(struct inode *dir, struct dentry *dentry,
6495 umode_t mode, bool excl)
6496 {
6497 struct btrfs_trans_handle *trans;
6498 struct btrfs_root *root = BTRFS_I(dir)->root;
6499 struct inode *inode = NULL;
6500 int drop_inode_on_err = 0;
6501 int err;
6502 u64 objectid;
6503 u64 index = 0;
6504
6505 /*
6506 * 2 for inode item and ref
6507 * 2 for dir items
6508 * 1 for xattr if selinux is on
6509 */
6510 trans = btrfs_start_transaction(root, 5);
6511 if (IS_ERR(trans))
6512 return PTR_ERR(trans);
6513
6514 err = btrfs_find_free_ino(root, &objectid);
6515 if (err)
6516 goto out_unlock;
6517
6518 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6519 dentry->d_name.len, btrfs_ino(dir), objectid,
6520 mode, &index);
6521 if (IS_ERR(inode)) {
6522 err = PTR_ERR(inode);
6523 goto out_unlock;
6524 }
6525 drop_inode_on_err = 1;
6526 /*
6527 * If the active LSM wants to access the inode during
6528 * d_instantiate it needs these. Smack checks to see
6529 * if the filesystem supports xattrs by looking at the
6530 * ops vector.
6531 */
6532 inode->i_fop = &btrfs_file_operations;
6533 inode->i_op = &btrfs_file_inode_operations;
6534 inode->i_mapping->a_ops = &btrfs_aops;
6535
6536 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6537 if (err)
6538 goto out_unlock_inode;
6539
6540 err = btrfs_update_inode(trans, root, inode);
6541 if (err)
6542 goto out_unlock_inode;
6543
6544 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6545 if (err)
6546 goto out_unlock_inode;
6547
6548 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6549 unlock_new_inode(inode);
6550 d_instantiate(dentry, inode);
6551
6552 out_unlock:
6553 btrfs_end_transaction(trans, root);
6554 if (err && drop_inode_on_err) {
6555 inode_dec_link_count(inode);
6556 iput(inode);
6557 }
6558 btrfs_balance_delayed_items(root);
6559 btrfs_btree_balance_dirty(root);
6560 return err;
6561
6562 out_unlock_inode:
6563 unlock_new_inode(inode);
6564 goto out_unlock;
6565
6566 }
6567
6568 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6569 struct dentry *dentry)
6570 {
6571 struct btrfs_trans_handle *trans = NULL;
6572 struct btrfs_root *root = BTRFS_I(dir)->root;
6573 struct inode *inode = d_inode(old_dentry);
6574 u64 index;
6575 int err;
6576 int drop_inode = 0;
6577
6578 /* do not allow sys_link's with other subvols of the same device */
6579 if (root->objectid != BTRFS_I(inode)->root->objectid)
6580 return -EXDEV;
6581
6582 if (inode->i_nlink >= BTRFS_LINK_MAX)
6583 return -EMLINK;
6584
6585 err = btrfs_set_inode_index(dir, &index);
6586 if (err)
6587 goto fail;
6588
6589 /*
6590 * 2 items for inode and inode ref
6591 * 2 items for dir items
6592 * 1 item for parent inode
6593 */
6594 trans = btrfs_start_transaction(root, 5);
6595 if (IS_ERR(trans)) {
6596 err = PTR_ERR(trans);
6597 trans = NULL;
6598 goto fail;
6599 }
6600
6601 /* There are several dir indexes for this inode, clear the cache. */
6602 BTRFS_I(inode)->dir_index = 0ULL;
6603 inc_nlink(inode);
6604 inode_inc_iversion(inode);
6605 inode->i_ctime = current_time(inode);
6606 ihold(inode);
6607 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6608
6609 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
6610
6611 if (err) {
6612 drop_inode = 1;
6613 } else {
6614 struct dentry *parent = dentry->d_parent;
6615 err = btrfs_update_inode(trans, root, inode);
6616 if (err)
6617 goto fail;
6618 if (inode->i_nlink == 1) {
6619 /*
6620 * If new hard link count is 1, it's a file created
6621 * with open(2) O_TMPFILE flag.
6622 */
6623 err = btrfs_orphan_del(trans, inode);
6624 if (err)
6625 goto fail;
6626 }
6627 d_instantiate(dentry, inode);
6628 btrfs_log_new_name(trans, inode, NULL, parent);
6629 }
6630
6631 btrfs_balance_delayed_items(root);
6632 fail:
6633 if (trans)
6634 btrfs_end_transaction(trans, root);
6635 if (drop_inode) {
6636 inode_dec_link_count(inode);
6637 iput(inode);
6638 }
6639 btrfs_btree_balance_dirty(root);
6640 return err;
6641 }
6642
6643 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6644 {
6645 struct inode *inode = NULL;
6646 struct btrfs_trans_handle *trans;
6647 struct btrfs_root *root = BTRFS_I(dir)->root;
6648 int err = 0;
6649 int drop_on_err = 0;
6650 u64 objectid = 0;
6651 u64 index = 0;
6652
6653 /*
6654 * 2 items for inode and ref
6655 * 2 items for dir items
6656 * 1 for xattr if selinux is on
6657 */
6658 trans = btrfs_start_transaction(root, 5);
6659 if (IS_ERR(trans))
6660 return PTR_ERR(trans);
6661
6662 err = btrfs_find_free_ino(root, &objectid);
6663 if (err)
6664 goto out_fail;
6665
6666 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6667 dentry->d_name.len, btrfs_ino(dir), objectid,
6668 S_IFDIR | mode, &index);
6669 if (IS_ERR(inode)) {
6670 err = PTR_ERR(inode);
6671 goto out_fail;
6672 }
6673
6674 drop_on_err = 1;
6675 /* these must be set before we unlock the inode */
6676 inode->i_op = &btrfs_dir_inode_operations;
6677 inode->i_fop = &btrfs_dir_file_operations;
6678
6679 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6680 if (err)
6681 goto out_fail_inode;
6682
6683 btrfs_i_size_write(inode, 0);
6684 err = btrfs_update_inode(trans, root, inode);
6685 if (err)
6686 goto out_fail_inode;
6687
6688 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
6689 dentry->d_name.len, 0, index);
6690 if (err)
6691 goto out_fail_inode;
6692
6693 d_instantiate(dentry, inode);
6694 /*
6695 * mkdir is special. We're unlocking after we call d_instantiate
6696 * to avoid a race with nfsd calling d_instantiate.
6697 */
6698 unlock_new_inode(inode);
6699 drop_on_err = 0;
6700
6701 out_fail:
6702 btrfs_end_transaction(trans, root);
6703 if (drop_on_err) {
6704 inode_dec_link_count(inode);
6705 iput(inode);
6706 }
6707 btrfs_balance_delayed_items(root);
6708 btrfs_btree_balance_dirty(root);
6709 return err;
6710
6711 out_fail_inode:
6712 unlock_new_inode(inode);
6713 goto out_fail;
6714 }
6715
6716 /* Find next extent map of a given extent map, caller needs to ensure locks */
6717 static struct extent_map *next_extent_map(struct extent_map *em)
6718 {
6719 struct rb_node *next;
6720
6721 next = rb_next(&em->rb_node);
6722 if (!next)
6723 return NULL;
6724 return container_of(next, struct extent_map, rb_node);
6725 }
6726
6727 static struct extent_map *prev_extent_map(struct extent_map *em)
6728 {
6729 struct rb_node *prev;
6730
6731 prev = rb_prev(&em->rb_node);
6732 if (!prev)
6733 return NULL;
6734 return container_of(prev, struct extent_map, rb_node);
6735 }
6736
6737 /* helper for btfs_get_extent. Given an existing extent in the tree,
6738 * the existing extent is the nearest extent to map_start,
6739 * and an extent that you want to insert, deal with overlap and insert
6740 * the best fitted new extent into the tree.
6741 */
6742 static int merge_extent_mapping(struct extent_map_tree *em_tree,
6743 struct extent_map *existing,
6744 struct extent_map *em,
6745 u64 map_start)
6746 {
6747 struct extent_map *prev;
6748 struct extent_map *next;
6749 u64 start;
6750 u64 end;
6751 u64 start_diff;
6752
6753 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
6754
6755 if (existing->start > map_start) {
6756 next = existing;
6757 prev = prev_extent_map(next);
6758 } else {
6759 prev = existing;
6760 next = next_extent_map(prev);
6761 }
6762
6763 start = prev ? extent_map_end(prev) : em->start;
6764 start = max_t(u64, start, em->start);
6765 end = next ? next->start : extent_map_end(em);
6766 end = min_t(u64, end, extent_map_end(em));
6767 start_diff = start - em->start;
6768 em->start = start;
6769 em->len = end - start;
6770 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
6771 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
6772 em->block_start += start_diff;
6773 em->block_len -= start_diff;
6774 }
6775 return add_extent_mapping(em_tree, em, 0);
6776 }
6777
6778 static noinline int uncompress_inline(struct btrfs_path *path,
6779 struct page *page,
6780 size_t pg_offset, u64 extent_offset,
6781 struct btrfs_file_extent_item *item)
6782 {
6783 int ret;
6784 struct extent_buffer *leaf = path->nodes[0];
6785 char *tmp;
6786 size_t max_size;
6787 unsigned long inline_size;
6788 unsigned long ptr;
6789 int compress_type;
6790
6791 WARN_ON(pg_offset != 0);
6792 compress_type = btrfs_file_extent_compression(leaf, item);
6793 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6794 inline_size = btrfs_file_extent_inline_item_len(leaf,
6795 btrfs_item_nr(path->slots[0]));
6796 tmp = kmalloc(inline_size, GFP_NOFS);
6797 if (!tmp)
6798 return -ENOMEM;
6799 ptr = btrfs_file_extent_inline_start(item);
6800
6801 read_extent_buffer(leaf, tmp, ptr, inline_size);
6802
6803 max_size = min_t(unsigned long, PAGE_SIZE, max_size);
6804 ret = btrfs_decompress(compress_type, tmp, page,
6805 extent_offset, inline_size, max_size);
6806 kfree(tmp);
6807 return ret;
6808 }
6809
6810 /*
6811 * a bit scary, this does extent mapping from logical file offset to the disk.
6812 * the ugly parts come from merging extents from the disk with the in-ram
6813 * representation. This gets more complex because of the data=ordered code,
6814 * where the in-ram extents might be locked pending data=ordered completion.
6815 *
6816 * This also copies inline extents directly into the page.
6817 */
6818
6819 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
6820 size_t pg_offset, u64 start, u64 len,
6821 int create)
6822 {
6823 int ret;
6824 int err = 0;
6825 u64 extent_start = 0;
6826 u64 extent_end = 0;
6827 u64 objectid = btrfs_ino(inode);
6828 u32 found_type;
6829 struct btrfs_path *path = NULL;
6830 struct btrfs_root *root = BTRFS_I(inode)->root;
6831 struct btrfs_file_extent_item *item;
6832 struct extent_buffer *leaf;
6833 struct btrfs_key found_key;
6834 struct extent_map *em = NULL;
6835 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
6836 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6837 struct btrfs_trans_handle *trans = NULL;
6838 const bool new_inline = !page || create;
6839
6840 again:
6841 read_lock(&em_tree->lock);
6842 em = lookup_extent_mapping(em_tree, start, len);
6843 if (em)
6844 em->bdev = root->fs_info->fs_devices->latest_bdev;
6845 read_unlock(&em_tree->lock);
6846
6847 if (em) {
6848 if (em->start > start || em->start + em->len <= start)
6849 free_extent_map(em);
6850 else if (em->block_start == EXTENT_MAP_INLINE && page)
6851 free_extent_map(em);
6852 else
6853 goto out;
6854 }
6855 em = alloc_extent_map();
6856 if (!em) {
6857 err = -ENOMEM;
6858 goto out;
6859 }
6860 em->bdev = root->fs_info->fs_devices->latest_bdev;
6861 em->start = EXTENT_MAP_HOLE;
6862 em->orig_start = EXTENT_MAP_HOLE;
6863 em->len = (u64)-1;
6864 em->block_len = (u64)-1;
6865
6866 if (!path) {
6867 path = btrfs_alloc_path();
6868 if (!path) {
6869 err = -ENOMEM;
6870 goto out;
6871 }
6872 /*
6873 * Chances are we'll be called again, so go ahead and do
6874 * readahead
6875 */
6876 path->reada = READA_FORWARD;
6877 }
6878
6879 ret = btrfs_lookup_file_extent(trans, root, path,
6880 objectid, start, trans != NULL);
6881 if (ret < 0) {
6882 err = ret;
6883 goto out;
6884 }
6885
6886 if (ret != 0) {
6887 if (path->slots[0] == 0)
6888 goto not_found;
6889 path->slots[0]--;
6890 }
6891
6892 leaf = path->nodes[0];
6893 item = btrfs_item_ptr(leaf, path->slots[0],
6894 struct btrfs_file_extent_item);
6895 /* are we inside the extent that was found? */
6896 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6897 found_type = found_key.type;
6898 if (found_key.objectid != objectid ||
6899 found_type != BTRFS_EXTENT_DATA_KEY) {
6900 /*
6901 * If we backup past the first extent we want to move forward
6902 * and see if there is an extent in front of us, otherwise we'll
6903 * say there is a hole for our whole search range which can
6904 * cause problems.
6905 */
6906 extent_end = start;
6907 goto next;
6908 }
6909
6910 found_type = btrfs_file_extent_type(leaf, item);
6911 extent_start = found_key.offset;
6912 if (found_type == BTRFS_FILE_EXTENT_REG ||
6913 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6914 extent_end = extent_start +
6915 btrfs_file_extent_num_bytes(leaf, item);
6916 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6917 size_t size;
6918 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6919 extent_end = ALIGN(extent_start + size, root->sectorsize);
6920 }
6921 next:
6922 if (start >= extent_end) {
6923 path->slots[0]++;
6924 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6925 ret = btrfs_next_leaf(root, path);
6926 if (ret < 0) {
6927 err = ret;
6928 goto out;
6929 }
6930 if (ret > 0)
6931 goto not_found;
6932 leaf = path->nodes[0];
6933 }
6934 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6935 if (found_key.objectid != objectid ||
6936 found_key.type != BTRFS_EXTENT_DATA_KEY)
6937 goto not_found;
6938 if (start + len <= found_key.offset)
6939 goto not_found;
6940 if (start > found_key.offset)
6941 goto next;
6942 em->start = start;
6943 em->orig_start = start;
6944 em->len = found_key.offset - start;
6945 goto not_found_em;
6946 }
6947
6948 btrfs_extent_item_to_extent_map(inode, path, item, new_inline, em);
6949
6950 if (found_type == BTRFS_FILE_EXTENT_REG ||
6951 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6952 goto insert;
6953 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6954 unsigned long ptr;
6955 char *map;
6956 size_t size;
6957 size_t extent_offset;
6958 size_t copy_size;
6959
6960 if (new_inline)
6961 goto out;
6962
6963 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6964 extent_offset = page_offset(page) + pg_offset - extent_start;
6965 copy_size = min_t(u64, PAGE_SIZE - pg_offset,
6966 size - extent_offset);
6967 em->start = extent_start + extent_offset;
6968 em->len = ALIGN(copy_size, root->sectorsize);
6969 em->orig_block_len = em->len;
6970 em->orig_start = em->start;
6971 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6972 if (create == 0 && !PageUptodate(page)) {
6973 if (btrfs_file_extent_compression(leaf, item) !=
6974 BTRFS_COMPRESS_NONE) {
6975 ret = uncompress_inline(path, page, pg_offset,
6976 extent_offset, item);
6977 if (ret) {
6978 err = ret;
6979 goto out;
6980 }
6981 } else {
6982 map = kmap(page);
6983 read_extent_buffer(leaf, map + pg_offset, ptr,
6984 copy_size);
6985 if (pg_offset + copy_size < PAGE_SIZE) {
6986 memset(map + pg_offset + copy_size, 0,
6987 PAGE_SIZE - pg_offset -
6988 copy_size);
6989 }
6990 kunmap(page);
6991 }
6992 flush_dcache_page(page);
6993 } else if (create && PageUptodate(page)) {
6994 BUG();
6995 if (!trans) {
6996 kunmap(page);
6997 free_extent_map(em);
6998 em = NULL;
6999
7000 btrfs_release_path(path);
7001 trans = btrfs_join_transaction(root);
7002
7003 if (IS_ERR(trans))
7004 return ERR_CAST(trans);
7005 goto again;
7006 }
7007 map = kmap(page);
7008 write_extent_buffer(leaf, map + pg_offset, ptr,
7009 copy_size);
7010 kunmap(page);
7011 btrfs_mark_buffer_dirty(leaf);
7012 }
7013 set_extent_uptodate(io_tree, em->start,
7014 extent_map_end(em) - 1, NULL, GFP_NOFS);
7015 goto insert;
7016 }
7017 not_found:
7018 em->start = start;
7019 em->orig_start = start;
7020 em->len = len;
7021 not_found_em:
7022 em->block_start = EXTENT_MAP_HOLE;
7023 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
7024 insert:
7025 btrfs_release_path(path);
7026 if (em->start > start || extent_map_end(em) <= start) {
7027 btrfs_err(root->fs_info,
7028 "bad extent! em: [%llu %llu] passed [%llu %llu]",
7029 em->start, em->len, start, len);
7030 err = -EIO;
7031 goto out;
7032 }
7033
7034 err = 0;
7035 write_lock(&em_tree->lock);
7036 ret = add_extent_mapping(em_tree, em, 0);
7037 /* it is possible that someone inserted the extent into the tree
7038 * while we had the lock dropped. It is also possible that
7039 * an overlapping map exists in the tree
7040 */
7041 if (ret == -EEXIST) {
7042 struct extent_map *existing;
7043
7044 ret = 0;
7045
7046 existing = search_extent_mapping(em_tree, start, len);
7047 /*
7048 * existing will always be non-NULL, since there must be
7049 * extent causing the -EEXIST.
7050 */
7051 if (existing->start == em->start &&
7052 extent_map_end(existing) == extent_map_end(em) &&
7053 em->block_start == existing->block_start) {
7054 /*
7055 * these two extents are the same, it happens
7056 * with inlines especially
7057 */
7058 free_extent_map(em);
7059 em = existing;
7060 err = 0;
7061
7062 } else if (start >= extent_map_end(existing) ||
7063 start <= existing->start) {
7064 /*
7065 * The existing extent map is the one nearest to
7066 * the [start, start + len) range which overlaps
7067 */
7068 err = merge_extent_mapping(em_tree, existing,
7069 em, start);
7070 free_extent_map(existing);
7071 if (err) {
7072 free_extent_map(em);
7073 em = NULL;
7074 }
7075 } else {
7076 free_extent_map(em);
7077 em = existing;
7078 err = 0;
7079 }
7080 }
7081 write_unlock(&em_tree->lock);
7082 out:
7083
7084 trace_btrfs_get_extent(root, em);
7085
7086 btrfs_free_path(path);
7087 if (trans) {
7088 ret = btrfs_end_transaction(trans, root);
7089 if (!err)
7090 err = ret;
7091 }
7092 if (err) {
7093 free_extent_map(em);
7094 return ERR_PTR(err);
7095 }
7096 BUG_ON(!em); /* Error is always set */
7097 return em;
7098 }
7099
7100 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
7101 size_t pg_offset, u64 start, u64 len,
7102 int create)
7103 {
7104 struct extent_map *em;
7105 struct extent_map *hole_em = NULL;
7106 u64 range_start = start;
7107 u64 end;
7108 u64 found;
7109 u64 found_end;
7110 int err = 0;
7111
7112 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
7113 if (IS_ERR(em))
7114 return em;
7115 if (em) {
7116 /*
7117 * if our em maps to
7118 * - a hole or
7119 * - a pre-alloc extent,
7120 * there might actually be delalloc bytes behind it.
7121 */
7122 if (em->block_start != EXTENT_MAP_HOLE &&
7123 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7124 return em;
7125 else
7126 hole_em = em;
7127 }
7128
7129 /* check to see if we've wrapped (len == -1 or similar) */
7130 end = start + len;
7131 if (end < start)
7132 end = (u64)-1;
7133 else
7134 end -= 1;
7135
7136 em = NULL;
7137
7138 /* ok, we didn't find anything, lets look for delalloc */
7139 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
7140 end, len, EXTENT_DELALLOC, 1);
7141 found_end = range_start + found;
7142 if (found_end < range_start)
7143 found_end = (u64)-1;
7144
7145 /*
7146 * we didn't find anything useful, return
7147 * the original results from get_extent()
7148 */
7149 if (range_start > end || found_end <= start) {
7150 em = hole_em;
7151 hole_em = NULL;
7152 goto out;
7153 }
7154
7155 /* adjust the range_start to make sure it doesn't
7156 * go backwards from the start they passed in
7157 */
7158 range_start = max(start, range_start);
7159 found = found_end - range_start;
7160
7161 if (found > 0) {
7162 u64 hole_start = start;
7163 u64 hole_len = len;
7164
7165 em = alloc_extent_map();
7166 if (!em) {
7167 err = -ENOMEM;
7168 goto out;
7169 }
7170 /*
7171 * when btrfs_get_extent can't find anything it
7172 * returns one huge hole
7173 *
7174 * make sure what it found really fits our range, and
7175 * adjust to make sure it is based on the start from
7176 * the caller
7177 */
7178 if (hole_em) {
7179 u64 calc_end = extent_map_end(hole_em);
7180
7181 if (calc_end <= start || (hole_em->start > end)) {
7182 free_extent_map(hole_em);
7183 hole_em = NULL;
7184 } else {
7185 hole_start = max(hole_em->start, start);
7186 hole_len = calc_end - hole_start;
7187 }
7188 }
7189 em->bdev = NULL;
7190 if (hole_em && range_start > hole_start) {
7191 /* our hole starts before our delalloc, so we
7192 * have to return just the parts of the hole
7193 * that go until the delalloc starts
7194 */
7195 em->len = min(hole_len,
7196 range_start - hole_start);
7197 em->start = hole_start;
7198 em->orig_start = hole_start;
7199 /*
7200 * don't adjust block start at all,
7201 * it is fixed at EXTENT_MAP_HOLE
7202 */
7203 em->block_start = hole_em->block_start;
7204 em->block_len = hole_len;
7205 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
7206 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7207 } else {
7208 em->start = range_start;
7209 em->len = found;
7210 em->orig_start = range_start;
7211 em->block_start = EXTENT_MAP_DELALLOC;
7212 em->block_len = found;
7213 }
7214 } else if (hole_em) {
7215 return hole_em;
7216 }
7217 out:
7218
7219 free_extent_map(hole_em);
7220 if (err) {
7221 free_extent_map(em);
7222 return ERR_PTR(err);
7223 }
7224 return em;
7225 }
7226
7227 static struct extent_map *btrfs_create_dio_extent(struct inode *inode,
7228 const u64 start,
7229 const u64 len,
7230 const u64 orig_start,
7231 const u64 block_start,
7232 const u64 block_len,
7233 const u64 orig_block_len,
7234 const u64 ram_bytes,
7235 const int type)
7236 {
7237 struct extent_map *em = NULL;
7238 int ret;
7239
7240 down_read(&BTRFS_I(inode)->dio_sem);
7241 if (type != BTRFS_ORDERED_NOCOW) {
7242 em = create_pinned_em(inode, start, len, orig_start,
7243 block_start, block_len, orig_block_len,
7244 ram_bytes, type);
7245 if (IS_ERR(em))
7246 goto out;
7247 }
7248 ret = btrfs_add_ordered_extent_dio(inode, start, block_start,
7249 len, block_len, type);
7250 if (ret) {
7251 if (em) {
7252 free_extent_map(em);
7253 btrfs_drop_extent_cache(inode, start,
7254 start + len - 1, 0);
7255 }
7256 em = ERR_PTR(ret);
7257 }
7258 out:
7259 up_read(&BTRFS_I(inode)->dio_sem);
7260
7261 return em;
7262 }
7263
7264 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7265 u64 start, u64 len)
7266 {
7267 struct btrfs_root *root = BTRFS_I(inode)->root;
7268 struct extent_map *em;
7269 struct btrfs_key ins;
7270 u64 alloc_hint;
7271 int ret;
7272
7273 alloc_hint = get_extent_allocation_hint(inode, start, len);
7274 ret = btrfs_reserve_extent(root, len, len, root->sectorsize, 0,
7275 alloc_hint, &ins, 1, 1);
7276 if (ret)
7277 return ERR_PTR(ret);
7278
7279 em = btrfs_create_dio_extent(inode, start, ins.offset, start,
7280 ins.objectid, ins.offset, ins.offset,
7281 ins.offset, 0);
7282 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
7283 if (IS_ERR(em))
7284 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
7285
7286 return em;
7287 }
7288
7289 /*
7290 * returns 1 when the nocow is safe, < 1 on error, 0 if the
7291 * block must be cow'd
7292 */
7293 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7294 u64 *orig_start, u64 *orig_block_len,
7295 u64 *ram_bytes)
7296 {
7297 struct btrfs_trans_handle *trans;
7298 struct btrfs_path *path;
7299 int ret;
7300 struct extent_buffer *leaf;
7301 struct btrfs_root *root = BTRFS_I(inode)->root;
7302 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7303 struct btrfs_file_extent_item *fi;
7304 struct btrfs_key key;
7305 u64 disk_bytenr;
7306 u64 backref_offset;
7307 u64 extent_end;
7308 u64 num_bytes;
7309 int slot;
7310 int found_type;
7311 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7312
7313 path = btrfs_alloc_path();
7314 if (!path)
7315 return -ENOMEM;
7316
7317 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
7318 offset, 0);
7319 if (ret < 0)
7320 goto out;
7321
7322 slot = path->slots[0];
7323 if (ret == 1) {
7324 if (slot == 0) {
7325 /* can't find the item, must cow */
7326 ret = 0;
7327 goto out;
7328 }
7329 slot--;
7330 }
7331 ret = 0;
7332 leaf = path->nodes[0];
7333 btrfs_item_key_to_cpu(leaf, &key, slot);
7334 if (key.objectid != btrfs_ino(inode) ||
7335 key.type != BTRFS_EXTENT_DATA_KEY) {
7336 /* not our file or wrong item type, must cow */
7337 goto out;
7338 }
7339
7340 if (key.offset > offset) {
7341 /* Wrong offset, must cow */
7342 goto out;
7343 }
7344
7345 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7346 found_type = btrfs_file_extent_type(leaf, fi);
7347 if (found_type != BTRFS_FILE_EXTENT_REG &&
7348 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7349 /* not a regular extent, must cow */
7350 goto out;
7351 }
7352
7353 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7354 goto out;
7355
7356 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7357 if (extent_end <= offset)
7358 goto out;
7359
7360 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7361 if (disk_bytenr == 0)
7362 goto out;
7363
7364 if (btrfs_file_extent_compression(leaf, fi) ||
7365 btrfs_file_extent_encryption(leaf, fi) ||
7366 btrfs_file_extent_other_encoding(leaf, fi))
7367 goto out;
7368
7369 backref_offset = btrfs_file_extent_offset(leaf, fi);
7370
7371 if (orig_start) {
7372 *orig_start = key.offset - backref_offset;
7373 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7374 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7375 }
7376
7377 if (btrfs_extent_readonly(root, disk_bytenr))
7378 goto out;
7379
7380 num_bytes = min(offset + *len, extent_end) - offset;
7381 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7382 u64 range_end;
7383
7384 range_end = round_up(offset + num_bytes, root->sectorsize) - 1;
7385 ret = test_range_bit(io_tree, offset, range_end,
7386 EXTENT_DELALLOC, 0, NULL);
7387 if (ret) {
7388 ret = -EAGAIN;
7389 goto out;
7390 }
7391 }
7392
7393 btrfs_release_path(path);
7394
7395 /*
7396 * look for other files referencing this extent, if we
7397 * find any we must cow
7398 */
7399 trans = btrfs_join_transaction(root);
7400 if (IS_ERR(trans)) {
7401 ret = 0;
7402 goto out;
7403 }
7404
7405 ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
7406 key.offset - backref_offset, disk_bytenr);
7407 btrfs_end_transaction(trans, root);
7408 if (ret) {
7409 ret = 0;
7410 goto out;
7411 }
7412
7413 /*
7414 * adjust disk_bytenr and num_bytes to cover just the bytes
7415 * in this extent we are about to write. If there
7416 * are any csums in that range we have to cow in order
7417 * to keep the csums correct
7418 */
7419 disk_bytenr += backref_offset;
7420 disk_bytenr += offset - key.offset;
7421 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
7422 goto out;
7423 /*
7424 * all of the above have passed, it is safe to overwrite this extent
7425 * without cow
7426 */
7427 *len = num_bytes;
7428 ret = 1;
7429 out:
7430 btrfs_free_path(path);
7431 return ret;
7432 }
7433
7434 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
7435 {
7436 struct radix_tree_root *root = &inode->i_mapping->page_tree;
7437 int found = false;
7438 void **pagep = NULL;
7439 struct page *page = NULL;
7440 int start_idx;
7441 int end_idx;
7442
7443 start_idx = start >> PAGE_SHIFT;
7444
7445 /*
7446 * end is the last byte in the last page. end == start is legal
7447 */
7448 end_idx = end >> PAGE_SHIFT;
7449
7450 rcu_read_lock();
7451
7452 /* Most of the code in this while loop is lifted from
7453 * find_get_page. It's been modified to begin searching from a
7454 * page and return just the first page found in that range. If the
7455 * found idx is less than or equal to the end idx then we know that
7456 * a page exists. If no pages are found or if those pages are
7457 * outside of the range then we're fine (yay!) */
7458 while (page == NULL &&
7459 radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
7460 page = radix_tree_deref_slot(pagep);
7461 if (unlikely(!page))
7462 break;
7463
7464 if (radix_tree_exception(page)) {
7465 if (radix_tree_deref_retry(page)) {
7466 page = NULL;
7467 continue;
7468 }
7469 /*
7470 * Otherwise, shmem/tmpfs must be storing a swap entry
7471 * here as an exceptional entry: so return it without
7472 * attempting to raise page count.
7473 */
7474 page = NULL;
7475 break; /* TODO: Is this relevant for this use case? */
7476 }
7477
7478 if (!page_cache_get_speculative(page)) {
7479 page = NULL;
7480 continue;
7481 }
7482
7483 /*
7484 * Has the page moved?
7485 * This is part of the lockless pagecache protocol. See
7486 * include/linux/pagemap.h for details.
7487 */
7488 if (unlikely(page != *pagep)) {
7489 put_page(page);
7490 page = NULL;
7491 }
7492 }
7493
7494 if (page) {
7495 if (page->index <= end_idx)
7496 found = true;
7497 put_page(page);
7498 }
7499
7500 rcu_read_unlock();
7501 return found;
7502 }
7503
7504 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7505 struct extent_state **cached_state, int writing)
7506 {
7507 struct btrfs_ordered_extent *ordered;
7508 int ret = 0;
7509
7510 while (1) {
7511 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7512 cached_state);
7513 /*
7514 * We're concerned with the entire range that we're going to be
7515 * doing DIO to, so we need to make sure there's no ordered
7516 * extents in this range.
7517 */
7518 ordered = btrfs_lookup_ordered_range(inode, lockstart,
7519 lockend - lockstart + 1);
7520
7521 /*
7522 * We need to make sure there are no buffered pages in this
7523 * range either, we could have raced between the invalidate in
7524 * generic_file_direct_write and locking the extent. The
7525 * invalidate needs to happen so that reads after a write do not
7526 * get stale data.
7527 */
7528 if (!ordered &&
7529 (!writing ||
7530 !btrfs_page_exists_in_range(inode, lockstart, lockend)))
7531 break;
7532
7533 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7534 cached_state, GFP_NOFS);
7535
7536 if (ordered) {
7537 /*
7538 * If we are doing a DIO read and the ordered extent we
7539 * found is for a buffered write, we can not wait for it
7540 * to complete and retry, because if we do so we can
7541 * deadlock with concurrent buffered writes on page
7542 * locks. This happens only if our DIO read covers more
7543 * than one extent map, if at this point has already
7544 * created an ordered extent for a previous extent map
7545 * and locked its range in the inode's io tree, and a
7546 * concurrent write against that previous extent map's
7547 * range and this range started (we unlock the ranges
7548 * in the io tree only when the bios complete and
7549 * buffered writes always lock pages before attempting
7550 * to lock range in the io tree).
7551 */
7552 if (writing ||
7553 test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags))
7554 btrfs_start_ordered_extent(inode, ordered, 1);
7555 else
7556 ret = -ENOTBLK;
7557 btrfs_put_ordered_extent(ordered);
7558 } else {
7559 /*
7560 * We could trigger writeback for this range (and wait
7561 * for it to complete) and then invalidate the pages for
7562 * this range (through invalidate_inode_pages2_range()),
7563 * but that can lead us to a deadlock with a concurrent
7564 * call to readpages() (a buffered read or a defrag call
7565 * triggered a readahead) on a page lock due to an
7566 * ordered dio extent we created before but did not have
7567 * yet a corresponding bio submitted (whence it can not
7568 * complete), which makes readpages() wait for that
7569 * ordered extent to complete while holding a lock on
7570 * that page.
7571 */
7572 ret = -ENOTBLK;
7573 }
7574
7575 if (ret)
7576 break;
7577
7578 cond_resched();
7579 }
7580
7581 return ret;
7582 }
7583
7584 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
7585 u64 len, u64 orig_start,
7586 u64 block_start, u64 block_len,
7587 u64 orig_block_len, u64 ram_bytes,
7588 int type)
7589 {
7590 struct extent_map_tree *em_tree;
7591 struct extent_map *em;
7592 struct btrfs_root *root = BTRFS_I(inode)->root;
7593 int ret;
7594
7595 em_tree = &BTRFS_I(inode)->extent_tree;
7596 em = alloc_extent_map();
7597 if (!em)
7598 return ERR_PTR(-ENOMEM);
7599
7600 em->start = start;
7601 em->orig_start = orig_start;
7602 em->mod_start = start;
7603 em->mod_len = len;
7604 em->len = len;
7605 em->block_len = block_len;
7606 em->block_start = block_start;
7607 em->bdev = root->fs_info->fs_devices->latest_bdev;
7608 em->orig_block_len = orig_block_len;
7609 em->ram_bytes = ram_bytes;
7610 em->generation = -1;
7611 set_bit(EXTENT_FLAG_PINNED, &em->flags);
7612 if (type == BTRFS_ORDERED_PREALLOC)
7613 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7614
7615 do {
7616 btrfs_drop_extent_cache(inode, em->start,
7617 em->start + em->len - 1, 0);
7618 write_lock(&em_tree->lock);
7619 ret = add_extent_mapping(em_tree, em, 1);
7620 write_unlock(&em_tree->lock);
7621 } while (ret == -EEXIST);
7622
7623 if (ret) {
7624 free_extent_map(em);
7625 return ERR_PTR(ret);
7626 }
7627
7628 return em;
7629 }
7630
7631 static void adjust_dio_outstanding_extents(struct inode *inode,
7632 struct btrfs_dio_data *dio_data,
7633 const u64 len)
7634 {
7635 unsigned num_extents;
7636
7637 num_extents = (unsigned) div64_u64(len + BTRFS_MAX_EXTENT_SIZE - 1,
7638 BTRFS_MAX_EXTENT_SIZE);
7639 /*
7640 * If we have an outstanding_extents count still set then we're
7641 * within our reservation, otherwise we need to adjust our inode
7642 * counter appropriately.
7643 */
7644 if (dio_data->outstanding_extents) {
7645 dio_data->outstanding_extents -= num_extents;
7646 } else {
7647 spin_lock(&BTRFS_I(inode)->lock);
7648 BTRFS_I(inode)->outstanding_extents += num_extents;
7649 spin_unlock(&BTRFS_I(inode)->lock);
7650 }
7651 }
7652
7653 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7654 struct buffer_head *bh_result, int create)
7655 {
7656 struct extent_map *em;
7657 struct btrfs_root *root = BTRFS_I(inode)->root;
7658 struct extent_state *cached_state = NULL;
7659 struct btrfs_dio_data *dio_data = NULL;
7660 u64 start = iblock << inode->i_blkbits;
7661 u64 lockstart, lockend;
7662 u64 len = bh_result->b_size;
7663 int unlock_bits = EXTENT_LOCKED;
7664 int ret = 0;
7665
7666 if (create)
7667 unlock_bits |= EXTENT_DIRTY;
7668 else
7669 len = min_t(u64, len, root->sectorsize);
7670
7671 lockstart = start;
7672 lockend = start + len - 1;
7673
7674 if (current->journal_info) {
7675 /*
7676 * Need to pull our outstanding extents and set journal_info to NULL so
7677 * that anything that needs to check if there's a transaction doesn't get
7678 * confused.
7679 */
7680 dio_data = current->journal_info;
7681 current->journal_info = NULL;
7682 }
7683
7684 /*
7685 * If this errors out it's because we couldn't invalidate pagecache for
7686 * this range and we need to fallback to buffered.
7687 */
7688 if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
7689 create)) {
7690 ret = -ENOTBLK;
7691 goto err;
7692 }
7693
7694 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
7695 if (IS_ERR(em)) {
7696 ret = PTR_ERR(em);
7697 goto unlock_err;
7698 }
7699
7700 /*
7701 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7702 * io. INLINE is special, and we could probably kludge it in here, but
7703 * it's still buffered so for safety lets just fall back to the generic
7704 * buffered path.
7705 *
7706 * For COMPRESSED we _have_ to read the entire extent in so we can
7707 * decompress it, so there will be buffering required no matter what we
7708 * do, so go ahead and fallback to buffered.
7709 *
7710 * We return -ENOTBLK because that's what makes DIO go ahead and go back
7711 * to buffered IO. Don't blame me, this is the price we pay for using
7712 * the generic code.
7713 */
7714 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7715 em->block_start == EXTENT_MAP_INLINE) {
7716 free_extent_map(em);
7717 ret = -ENOTBLK;
7718 goto unlock_err;
7719 }
7720
7721 /* Just a good old fashioned hole, return */
7722 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
7723 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
7724 free_extent_map(em);
7725 goto unlock_err;
7726 }
7727
7728 /*
7729 * We don't allocate a new extent in the following cases
7730 *
7731 * 1) The inode is marked as NODATACOW. In this case we'll just use the
7732 * existing extent.
7733 * 2) The extent is marked as PREALLOC. We're good to go here and can
7734 * just use the extent.
7735 *
7736 */
7737 if (!create) {
7738 len = min(len, em->len - (start - em->start));
7739 lockstart = start + len;
7740 goto unlock;
7741 }
7742
7743 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7744 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7745 em->block_start != EXTENT_MAP_HOLE)) {
7746 int type;
7747 u64 block_start, orig_start, orig_block_len, ram_bytes;
7748
7749 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7750 type = BTRFS_ORDERED_PREALLOC;
7751 else
7752 type = BTRFS_ORDERED_NOCOW;
7753 len = min(len, em->len - (start - em->start));
7754 block_start = em->block_start + (start - em->start);
7755
7756 if (can_nocow_extent(inode, start, &len, &orig_start,
7757 &orig_block_len, &ram_bytes) == 1 &&
7758 btrfs_inc_nocow_writers(root->fs_info, block_start)) {
7759 struct extent_map *em2;
7760
7761 em2 = btrfs_create_dio_extent(inode, start, len,
7762 orig_start, block_start,
7763 len, orig_block_len,
7764 ram_bytes, type);
7765 btrfs_dec_nocow_writers(root->fs_info, block_start);
7766 if (type == BTRFS_ORDERED_PREALLOC) {
7767 free_extent_map(em);
7768 em = em2;
7769 }
7770 if (em2 && IS_ERR(em2)) {
7771 ret = PTR_ERR(em2);
7772 goto unlock_err;
7773 }
7774 /*
7775 * For inode marked NODATACOW or extent marked PREALLOC,
7776 * use the existing or preallocated extent, so does not
7777 * need to adjust btrfs_space_info's bytes_may_use.
7778 */
7779 btrfs_free_reserved_data_space_noquota(inode,
7780 start, len);
7781 goto unlock;
7782 }
7783 }
7784
7785 /*
7786 * this will cow the extent, reset the len in case we changed
7787 * it above
7788 */
7789 len = bh_result->b_size;
7790 free_extent_map(em);
7791 em = btrfs_new_extent_direct(inode, start, len);
7792 if (IS_ERR(em)) {
7793 ret = PTR_ERR(em);
7794 goto unlock_err;
7795 }
7796 len = min(len, em->len - (start - em->start));
7797 unlock:
7798 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7799 inode->i_blkbits;
7800 bh_result->b_size = len;
7801 bh_result->b_bdev = em->bdev;
7802 set_buffer_mapped(bh_result);
7803 if (create) {
7804 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7805 set_buffer_new(bh_result);
7806
7807 /*
7808 * Need to update the i_size under the extent lock so buffered
7809 * readers will get the updated i_size when we unlock.
7810 */
7811 if (start + len > i_size_read(inode))
7812 i_size_write(inode, start + len);
7813
7814 adjust_dio_outstanding_extents(inode, dio_data, len);
7815 WARN_ON(dio_data->reserve < len);
7816 dio_data->reserve -= len;
7817 dio_data->unsubmitted_oe_range_end = start + len;
7818 current->journal_info = dio_data;
7819 }
7820
7821 /*
7822 * In the case of write we need to clear and unlock the entire range,
7823 * in the case of read we need to unlock only the end area that we
7824 * aren't using if there is any left over space.
7825 */
7826 if (lockstart < lockend) {
7827 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7828 lockend, unlock_bits, 1, 0,
7829 &cached_state, GFP_NOFS);
7830 } else {
7831 free_extent_state(cached_state);
7832 }
7833
7834 free_extent_map(em);
7835
7836 return 0;
7837
7838 unlock_err:
7839 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7840 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
7841 err:
7842 if (dio_data)
7843 current->journal_info = dio_data;
7844 /*
7845 * Compensate the delalloc release we do in btrfs_direct_IO() when we
7846 * write less data then expected, so that we don't underflow our inode's
7847 * outstanding extents counter.
7848 */
7849 if (create && dio_data)
7850 adjust_dio_outstanding_extents(inode, dio_data, len);
7851
7852 return ret;
7853 }
7854
7855 static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio,
7856 int mirror_num)
7857 {
7858 struct btrfs_root *root = BTRFS_I(inode)->root;
7859 int ret;
7860
7861 BUG_ON(bio_op(bio) == REQ_OP_WRITE);
7862
7863 bio_get(bio);
7864
7865 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
7866 BTRFS_WQ_ENDIO_DIO_REPAIR);
7867 if (ret)
7868 goto err;
7869
7870 ret = btrfs_map_bio(root, bio, mirror_num, 0);
7871 err:
7872 bio_put(bio);
7873 return ret;
7874 }
7875
7876 static int btrfs_check_dio_repairable(struct inode *inode,
7877 struct bio *failed_bio,
7878 struct io_failure_record *failrec,
7879 int failed_mirror)
7880 {
7881 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7882 int num_copies;
7883
7884 num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len);
7885 if (num_copies == 1) {
7886 /*
7887 * we only have a single copy of the data, so don't bother with
7888 * all the retry and error correction code that follows. no
7889 * matter what the error is, it is very likely to persist.
7890 */
7891 btrfs_debug(fs_info,
7892 "Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
7893 num_copies, failrec->this_mirror, failed_mirror);
7894 return 0;
7895 }
7896
7897 failrec->failed_mirror = failed_mirror;
7898 failrec->this_mirror++;
7899 if (failrec->this_mirror == failed_mirror)
7900 failrec->this_mirror++;
7901
7902 if (failrec->this_mirror > num_copies) {
7903 btrfs_debug(fs_info,
7904 "Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
7905 num_copies, failrec->this_mirror, failed_mirror);
7906 return 0;
7907 }
7908
7909 return 1;
7910 }
7911
7912 static int dio_read_error(struct inode *inode, struct bio *failed_bio,
7913 struct page *page, unsigned int pgoff,
7914 u64 start, u64 end, int failed_mirror,
7915 bio_end_io_t *repair_endio, void *repair_arg)
7916 {
7917 struct io_failure_record *failrec;
7918 struct bio *bio;
7919 int isector;
7920 int read_mode = 0;
7921 int ret;
7922
7923 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
7924
7925 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
7926 if (ret)
7927 return ret;
7928
7929 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
7930 failed_mirror);
7931 if (!ret) {
7932 free_io_failure(inode, failrec);
7933 return -EIO;
7934 }
7935
7936 if ((failed_bio->bi_vcnt > 1)
7937 || (failed_bio->bi_io_vec->bv_len
7938 > BTRFS_I(inode)->root->sectorsize))
7939 read_mode |= REQ_FAILFAST_DEV;
7940
7941 isector = start - btrfs_io_bio(failed_bio)->logical;
7942 isector >>= inode->i_sb->s_blocksize_bits;
7943 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
7944 pgoff, isector, repair_endio, repair_arg);
7945 if (!bio) {
7946 free_io_failure(inode, failrec);
7947 return -EIO;
7948 }
7949 bio_set_op_attrs(bio, REQ_OP_READ, read_mode);
7950
7951 btrfs_debug(BTRFS_I(inode)->root->fs_info,
7952 "Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n",
7953 read_mode, failrec->this_mirror, failrec->in_validation);
7954
7955 ret = submit_dio_repair_bio(inode, bio, failrec->this_mirror);
7956 if (ret) {
7957 free_io_failure(inode, failrec);
7958 bio_put(bio);
7959 }
7960
7961 return ret;
7962 }
7963
7964 struct btrfs_retry_complete {
7965 struct completion done;
7966 struct inode *inode;
7967 u64 start;
7968 int uptodate;
7969 };
7970
7971 static void btrfs_retry_endio_nocsum(struct bio *bio)
7972 {
7973 struct btrfs_retry_complete *done = bio->bi_private;
7974 struct inode *inode;
7975 struct bio_vec *bvec;
7976 int i;
7977
7978 if (bio->bi_error)
7979 goto end;
7980
7981 ASSERT(bio->bi_vcnt == 1);
7982 inode = bio->bi_io_vec->bv_page->mapping->host;
7983 ASSERT(bio->bi_io_vec->bv_len == BTRFS_I(inode)->root->sectorsize);
7984
7985 done->uptodate = 1;
7986 bio_for_each_segment_all(bvec, bio, i)
7987 clean_io_failure(done->inode, done->start, bvec->bv_page, 0);
7988 end:
7989 complete(&done->done);
7990 bio_put(bio);
7991 }
7992
7993 static int __btrfs_correct_data_nocsum(struct inode *inode,
7994 struct btrfs_io_bio *io_bio)
7995 {
7996 struct btrfs_fs_info *fs_info;
7997 struct bio_vec *bvec;
7998 struct btrfs_retry_complete done;
7999 u64 start;
8000 unsigned int pgoff;
8001 u32 sectorsize;
8002 int nr_sectors;
8003 int i;
8004 int ret;
8005
8006 fs_info = BTRFS_I(inode)->root->fs_info;
8007 sectorsize = BTRFS_I(inode)->root->sectorsize;
8008
8009 start = io_bio->logical;
8010 done.inode = inode;
8011
8012 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
8013 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
8014 pgoff = bvec->bv_offset;
8015
8016 next_block_or_try_again:
8017 done.uptodate = 0;
8018 done.start = start;
8019 init_completion(&done.done);
8020
8021 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page,
8022 pgoff, start, start + sectorsize - 1,
8023 io_bio->mirror_num,
8024 btrfs_retry_endio_nocsum, &done);
8025 if (ret)
8026 return ret;
8027
8028 wait_for_completion(&done.done);
8029
8030 if (!done.uptodate) {
8031 /* We might have another mirror, so try again */
8032 goto next_block_or_try_again;
8033 }
8034
8035 start += sectorsize;
8036
8037 if (nr_sectors--) {
8038 pgoff += sectorsize;
8039 goto next_block_or_try_again;
8040 }
8041 }
8042
8043 return 0;
8044 }
8045
8046 static void btrfs_retry_endio(struct bio *bio)
8047 {
8048 struct btrfs_retry_complete *done = bio->bi_private;
8049 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8050 struct inode *inode;
8051 struct bio_vec *bvec;
8052 u64 start;
8053 int uptodate;
8054 int ret;
8055 int i;
8056
8057 if (bio->bi_error)
8058 goto end;
8059
8060 uptodate = 1;
8061
8062 start = done->start;
8063
8064 ASSERT(bio->bi_vcnt == 1);
8065 inode = bio->bi_io_vec->bv_page->mapping->host;
8066 ASSERT(bio->bi_io_vec->bv_len == BTRFS_I(inode)->root->sectorsize);
8067
8068 bio_for_each_segment_all(bvec, bio, i) {
8069 ret = __readpage_endio_check(done->inode, io_bio, i,
8070 bvec->bv_page, bvec->bv_offset,
8071 done->start, bvec->bv_len);
8072 if (!ret)
8073 clean_io_failure(done->inode, done->start,
8074 bvec->bv_page, bvec->bv_offset);
8075 else
8076 uptodate = 0;
8077 }
8078
8079 done->uptodate = uptodate;
8080 end:
8081 complete(&done->done);
8082 bio_put(bio);
8083 }
8084
8085 static int __btrfs_subio_endio_read(struct inode *inode,
8086 struct btrfs_io_bio *io_bio, int err)
8087 {
8088 struct btrfs_fs_info *fs_info;
8089 struct bio_vec *bvec;
8090 struct btrfs_retry_complete done;
8091 u64 start;
8092 u64 offset = 0;
8093 u32 sectorsize;
8094 int nr_sectors;
8095 unsigned int pgoff;
8096 int csum_pos;
8097 int i;
8098 int ret;
8099
8100 fs_info = BTRFS_I(inode)->root->fs_info;
8101 sectorsize = BTRFS_I(inode)->root->sectorsize;
8102
8103 err = 0;
8104 start = io_bio->logical;
8105 done.inode = inode;
8106
8107 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
8108 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
8109
8110 pgoff = bvec->bv_offset;
8111 next_block:
8112 csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset);
8113 ret = __readpage_endio_check(inode, io_bio, csum_pos,
8114 bvec->bv_page, pgoff, start,
8115 sectorsize);
8116 if (likely(!ret))
8117 goto next;
8118 try_again:
8119 done.uptodate = 0;
8120 done.start = start;
8121 init_completion(&done.done);
8122
8123 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page,
8124 pgoff, start, start + sectorsize - 1,
8125 io_bio->mirror_num,
8126 btrfs_retry_endio, &done);
8127 if (ret) {
8128 err = ret;
8129 goto next;
8130 }
8131
8132 wait_for_completion(&done.done);
8133
8134 if (!done.uptodate) {
8135 /* We might have another mirror, so try again */
8136 goto try_again;
8137 }
8138 next:
8139 offset += sectorsize;
8140 start += sectorsize;
8141
8142 ASSERT(nr_sectors);
8143
8144 if (--nr_sectors) {
8145 pgoff += sectorsize;
8146 goto next_block;
8147 }
8148 }
8149
8150 return err;
8151 }
8152
8153 static int btrfs_subio_endio_read(struct inode *inode,
8154 struct btrfs_io_bio *io_bio, int err)
8155 {
8156 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8157
8158 if (skip_csum) {
8159 if (unlikely(err))
8160 return __btrfs_correct_data_nocsum(inode, io_bio);
8161 else
8162 return 0;
8163 } else {
8164 return __btrfs_subio_endio_read(inode, io_bio, err);
8165 }
8166 }
8167
8168 static void btrfs_endio_direct_read(struct bio *bio)
8169 {
8170 struct btrfs_dio_private *dip = bio->bi_private;
8171 struct inode *inode = dip->inode;
8172 struct bio *dio_bio;
8173 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8174 int err = bio->bi_error;
8175
8176 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
8177 err = btrfs_subio_endio_read(inode, io_bio, err);
8178
8179 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
8180 dip->logical_offset + dip->bytes - 1);
8181 dio_bio = dip->dio_bio;
8182
8183 kfree(dip);
8184
8185 dio_bio->bi_error = bio->bi_error;
8186 dio_end_io(dio_bio, bio->bi_error);
8187
8188 if (io_bio->end_io)
8189 io_bio->end_io(io_bio, err);
8190 bio_put(bio);
8191 }
8192
8193 static void btrfs_endio_direct_write_update_ordered(struct inode *inode,
8194 const u64 offset,
8195 const u64 bytes,
8196 const int uptodate)
8197 {
8198 struct btrfs_root *root = BTRFS_I(inode)->root;
8199 struct btrfs_ordered_extent *ordered = NULL;
8200 u64 ordered_offset = offset;
8201 u64 ordered_bytes = bytes;
8202 int ret;
8203
8204 again:
8205 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
8206 &ordered_offset,
8207 ordered_bytes,
8208 uptodate);
8209 if (!ret)
8210 goto out_test;
8211
8212 btrfs_init_work(&ordered->work, btrfs_endio_write_helper,
8213 finish_ordered_fn, NULL, NULL);
8214 btrfs_queue_work(root->fs_info->endio_write_workers,
8215 &ordered->work);
8216 out_test:
8217 /*
8218 * our bio might span multiple ordered extents. If we haven't
8219 * completed the accounting for the whole dio, go back and try again
8220 */
8221 if (ordered_offset < offset + bytes) {
8222 ordered_bytes = offset + bytes - ordered_offset;
8223 ordered = NULL;
8224 goto again;
8225 }
8226 }
8227
8228 static void btrfs_endio_direct_write(struct bio *bio)
8229 {
8230 struct btrfs_dio_private *dip = bio->bi_private;
8231 struct bio *dio_bio = dip->dio_bio;
8232
8233 btrfs_endio_direct_write_update_ordered(dip->inode,
8234 dip->logical_offset,
8235 dip->bytes,
8236 !bio->bi_error);
8237
8238 kfree(dip);
8239
8240 dio_bio->bi_error = bio->bi_error;
8241 dio_end_io(dio_bio, bio->bi_error);
8242 bio_put(bio);
8243 }
8244
8245 static int __btrfs_submit_bio_start_direct_io(struct inode *inode,
8246 struct bio *bio, int mirror_num,
8247 unsigned long bio_flags, u64 offset)
8248 {
8249 int ret;
8250 struct btrfs_root *root = BTRFS_I(inode)->root;
8251 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
8252 BUG_ON(ret); /* -ENOMEM */
8253 return 0;
8254 }
8255
8256 static void btrfs_end_dio_bio(struct bio *bio)
8257 {
8258 struct btrfs_dio_private *dip = bio->bi_private;
8259 int err = bio->bi_error;
8260
8261 if (err)
8262 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
8263 "direct IO failed ino %llu rw %d,%u sector %#Lx len %u err no %d",
8264 btrfs_ino(dip->inode), bio_op(bio), bio->bi_opf,
8265 (unsigned long long)bio->bi_iter.bi_sector,
8266 bio->bi_iter.bi_size, err);
8267
8268 if (dip->subio_endio)
8269 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
8270
8271 if (err) {
8272 dip->errors = 1;
8273
8274 /*
8275 * before atomic variable goto zero, we must make sure
8276 * dip->errors is perceived to be set.
8277 */
8278 smp_mb__before_atomic();
8279 }
8280
8281 /* if there are more bios still pending for this dio, just exit */
8282 if (!atomic_dec_and_test(&dip->pending_bios))
8283 goto out;
8284
8285 if (dip->errors) {
8286 bio_io_error(dip->orig_bio);
8287 } else {
8288 dip->dio_bio->bi_error = 0;
8289 bio_endio(dip->orig_bio);
8290 }
8291 out:
8292 bio_put(bio);
8293 }
8294
8295 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
8296 u64 first_sector, gfp_t gfp_flags)
8297 {
8298 struct bio *bio;
8299 bio = btrfs_bio_alloc(bdev, first_sector, BIO_MAX_PAGES, gfp_flags);
8300 if (bio)
8301 bio_associate_current(bio);
8302 return bio;
8303 }
8304
8305 static inline int btrfs_lookup_and_bind_dio_csum(struct btrfs_root *root,
8306 struct inode *inode,
8307 struct btrfs_dio_private *dip,
8308 struct bio *bio,
8309 u64 file_offset)
8310 {
8311 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8312 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
8313 int ret;
8314
8315 /*
8316 * We load all the csum data we need when we submit
8317 * the first bio to reduce the csum tree search and
8318 * contention.
8319 */
8320 if (dip->logical_offset == file_offset) {
8321 ret = btrfs_lookup_bio_sums_dio(root, inode, dip->orig_bio,
8322 file_offset);
8323 if (ret)
8324 return ret;
8325 }
8326
8327 if (bio == dip->orig_bio)
8328 return 0;
8329
8330 file_offset -= dip->logical_offset;
8331 file_offset >>= inode->i_sb->s_blocksize_bits;
8332 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
8333
8334 return 0;
8335 }
8336
8337 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
8338 u64 file_offset, int skip_sum,
8339 int async_submit)
8340 {
8341 struct btrfs_dio_private *dip = bio->bi_private;
8342 bool write = bio_op(bio) == REQ_OP_WRITE;
8343 struct btrfs_root *root = BTRFS_I(inode)->root;
8344 int ret;
8345
8346 if (async_submit)
8347 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
8348
8349 bio_get(bio);
8350
8351 if (!write) {
8352 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
8353 BTRFS_WQ_ENDIO_DATA);
8354 if (ret)
8355 goto err;
8356 }
8357
8358 if (skip_sum)
8359 goto map;
8360
8361 if (write && async_submit) {
8362 ret = btrfs_wq_submit_bio(root->fs_info,
8363 inode, bio, 0, 0, file_offset,
8364 __btrfs_submit_bio_start_direct_io,
8365 __btrfs_submit_bio_done);
8366 goto err;
8367 } else if (write) {
8368 /*
8369 * If we aren't doing async submit, calculate the csum of the
8370 * bio now.
8371 */
8372 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
8373 if (ret)
8374 goto err;
8375 } else {
8376 ret = btrfs_lookup_and_bind_dio_csum(root, inode, dip, bio,
8377 file_offset);
8378 if (ret)
8379 goto err;
8380 }
8381 map:
8382 ret = btrfs_map_bio(root, bio, 0, async_submit);
8383 err:
8384 bio_put(bio);
8385 return ret;
8386 }
8387
8388 static int btrfs_submit_direct_hook(struct btrfs_dio_private *dip,
8389 int skip_sum)
8390 {
8391 struct inode *inode = dip->inode;
8392 struct btrfs_root *root = BTRFS_I(inode)->root;
8393 struct bio *bio;
8394 struct bio *orig_bio = dip->orig_bio;
8395 struct bio_vec *bvec = orig_bio->bi_io_vec;
8396 u64 start_sector = orig_bio->bi_iter.bi_sector;
8397 u64 file_offset = dip->logical_offset;
8398 u64 submit_len = 0;
8399 u64 map_length;
8400 u32 blocksize = root->sectorsize;
8401 int async_submit = 0;
8402 int nr_sectors;
8403 int ret;
8404 int i;
8405
8406 map_length = orig_bio->bi_iter.bi_size;
8407 ret = btrfs_map_block(root->fs_info, bio_op(orig_bio),
8408 start_sector << 9, &map_length, NULL, 0);
8409 if (ret)
8410 return -EIO;
8411
8412 if (map_length >= orig_bio->bi_iter.bi_size) {
8413 bio = orig_bio;
8414 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8415 goto submit;
8416 }
8417
8418 /* async crcs make it difficult to collect full stripe writes. */
8419 if (btrfs_get_alloc_profile(root, 1) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8420 async_submit = 0;
8421 else
8422 async_submit = 1;
8423
8424 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
8425 if (!bio)
8426 return -ENOMEM;
8427
8428 bio->bi_opf = orig_bio->bi_opf;
8429 bio->bi_private = dip;
8430 bio->bi_end_io = btrfs_end_dio_bio;
8431 btrfs_io_bio(bio)->logical = file_offset;
8432 atomic_inc(&dip->pending_bios);
8433
8434 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
8435 nr_sectors = BTRFS_BYTES_TO_BLKS(root->fs_info, bvec->bv_len);
8436 i = 0;
8437 next_block:
8438 if (unlikely(map_length < submit_len + blocksize ||
8439 bio_add_page(bio, bvec->bv_page, blocksize,
8440 bvec->bv_offset + (i * blocksize)) < blocksize)) {
8441 /*
8442 * inc the count before we submit the bio so
8443 * we know the end IO handler won't happen before
8444 * we inc the count. Otherwise, the dip might get freed
8445 * before we're done setting it up
8446 */
8447 atomic_inc(&dip->pending_bios);
8448 ret = __btrfs_submit_dio_bio(bio, inode,
8449 file_offset, skip_sum,
8450 async_submit);
8451 if (ret) {
8452 bio_put(bio);
8453 atomic_dec(&dip->pending_bios);
8454 goto out_err;
8455 }
8456
8457 start_sector += submit_len >> 9;
8458 file_offset += submit_len;
8459
8460 submit_len = 0;
8461
8462 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
8463 start_sector, GFP_NOFS);
8464 if (!bio)
8465 goto out_err;
8466 bio->bi_opf = orig_bio->bi_opf;
8467 bio->bi_private = dip;
8468 bio->bi_end_io = btrfs_end_dio_bio;
8469 btrfs_io_bio(bio)->logical = file_offset;
8470
8471 map_length = orig_bio->bi_iter.bi_size;
8472 ret = btrfs_map_block(root->fs_info, bio_op(orig_bio),
8473 start_sector << 9,
8474 &map_length, NULL, 0);
8475 if (ret) {
8476 bio_put(bio);
8477 goto out_err;
8478 }
8479
8480 goto next_block;
8481 } else {
8482 submit_len += blocksize;
8483 if (--nr_sectors) {
8484 i++;
8485 goto next_block;
8486 }
8487 bvec++;
8488 }
8489 }
8490
8491 submit:
8492 ret = __btrfs_submit_dio_bio(bio, inode, file_offset, skip_sum,
8493 async_submit);
8494 if (!ret)
8495 return 0;
8496
8497 bio_put(bio);
8498 out_err:
8499 dip->errors = 1;
8500 /*
8501 * before atomic variable goto zero, we must
8502 * make sure dip->errors is perceived to be set.
8503 */
8504 smp_mb__before_atomic();
8505 if (atomic_dec_and_test(&dip->pending_bios))
8506 bio_io_error(dip->orig_bio);
8507
8508 /* bio_end_io() will handle error, so we needn't return it */
8509 return 0;
8510 }
8511
8512 static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode,
8513 loff_t file_offset)
8514 {
8515 struct btrfs_dio_private *dip = NULL;
8516 struct bio *io_bio = NULL;
8517 struct btrfs_io_bio *btrfs_bio;
8518 int skip_sum;
8519 bool write = (bio_op(dio_bio) == REQ_OP_WRITE);
8520 int ret = 0;
8521
8522 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8523
8524 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
8525 if (!io_bio) {
8526 ret = -ENOMEM;
8527 goto free_ordered;
8528 }
8529
8530 dip = kzalloc(sizeof(*dip), GFP_NOFS);
8531 if (!dip) {
8532 ret = -ENOMEM;
8533 goto free_ordered;
8534 }
8535
8536 dip->private = dio_bio->bi_private;
8537 dip->inode = inode;
8538 dip->logical_offset = file_offset;
8539 dip->bytes = dio_bio->bi_iter.bi_size;
8540 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8541 io_bio->bi_private = dip;
8542 dip->orig_bio = io_bio;
8543 dip->dio_bio = dio_bio;
8544 atomic_set(&dip->pending_bios, 0);
8545 btrfs_bio = btrfs_io_bio(io_bio);
8546 btrfs_bio->logical = file_offset;
8547
8548 if (write) {
8549 io_bio->bi_end_io = btrfs_endio_direct_write;
8550 } else {
8551 io_bio->bi_end_io = btrfs_endio_direct_read;
8552 dip->subio_endio = btrfs_subio_endio_read;
8553 }
8554
8555 /*
8556 * Reset the range for unsubmitted ordered extents (to a 0 length range)
8557 * even if we fail to submit a bio, because in such case we do the
8558 * corresponding error handling below and it must not be done a second
8559 * time by btrfs_direct_IO().
8560 */
8561 if (write) {
8562 struct btrfs_dio_data *dio_data = current->journal_info;
8563
8564 dio_data->unsubmitted_oe_range_end = dip->logical_offset +
8565 dip->bytes;
8566 dio_data->unsubmitted_oe_range_start =
8567 dio_data->unsubmitted_oe_range_end;
8568 }
8569
8570 ret = btrfs_submit_direct_hook(dip, skip_sum);
8571 if (!ret)
8572 return;
8573
8574 if (btrfs_bio->end_io)
8575 btrfs_bio->end_io(btrfs_bio, ret);
8576
8577 free_ordered:
8578 /*
8579 * If we arrived here it means either we failed to submit the dip
8580 * or we either failed to clone the dio_bio or failed to allocate the
8581 * dip. If we cloned the dio_bio and allocated the dip, we can just
8582 * call bio_endio against our io_bio so that we get proper resource
8583 * cleanup if we fail to submit the dip, otherwise, we must do the
8584 * same as btrfs_endio_direct_[write|read] because we can't call these
8585 * callbacks - they require an allocated dip and a clone of dio_bio.
8586 */
8587 if (io_bio && dip) {
8588 io_bio->bi_error = -EIO;
8589 bio_endio(io_bio);
8590 /*
8591 * The end io callbacks free our dip, do the final put on io_bio
8592 * and all the cleanup and final put for dio_bio (through
8593 * dio_end_io()).
8594 */
8595 dip = NULL;
8596 io_bio = NULL;
8597 } else {
8598 if (write)
8599 btrfs_endio_direct_write_update_ordered(inode,
8600 file_offset,
8601 dio_bio->bi_iter.bi_size,
8602 0);
8603 else
8604 unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
8605 file_offset + dio_bio->bi_iter.bi_size - 1);
8606
8607 dio_bio->bi_error = -EIO;
8608 /*
8609 * Releases and cleans up our dio_bio, no need to bio_put()
8610 * nor bio_endio()/bio_io_error() against dio_bio.
8611 */
8612 dio_end_io(dio_bio, ret);
8613 }
8614 if (io_bio)
8615 bio_put(io_bio);
8616 kfree(dip);
8617 }
8618
8619 static ssize_t check_direct_IO(struct btrfs_root *root, struct kiocb *iocb,
8620 const struct iov_iter *iter, loff_t offset)
8621 {
8622 int seg;
8623 int i;
8624 unsigned blocksize_mask = root->sectorsize - 1;
8625 ssize_t retval = -EINVAL;
8626
8627 if (offset & blocksize_mask)
8628 goto out;
8629
8630 if (iov_iter_alignment(iter) & blocksize_mask)
8631 goto out;
8632
8633 /* If this is a write we don't need to check anymore */
8634 if (iov_iter_rw(iter) != READ || !iter_is_iovec(iter))
8635 return 0;
8636 /*
8637 * Check to make sure we don't have duplicate iov_base's in this
8638 * iovec, if so return EINVAL, otherwise we'll get csum errors
8639 * when reading back.
8640 */
8641 for (seg = 0; seg < iter->nr_segs; seg++) {
8642 for (i = seg + 1; i < iter->nr_segs; i++) {
8643 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8644 goto out;
8645 }
8646 }
8647 retval = 0;
8648 out:
8649 return retval;
8650 }
8651
8652 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
8653 {
8654 struct file *file = iocb->ki_filp;
8655 struct inode *inode = file->f_mapping->host;
8656 struct btrfs_root *root = BTRFS_I(inode)->root;
8657 struct btrfs_dio_data dio_data = { 0 };
8658 loff_t offset = iocb->ki_pos;
8659 size_t count = 0;
8660 int flags = 0;
8661 bool wakeup = true;
8662 bool relock = false;
8663 ssize_t ret;
8664
8665 if (check_direct_IO(BTRFS_I(inode)->root, iocb, iter, offset))
8666 return 0;
8667
8668 inode_dio_begin(inode);
8669 smp_mb__after_atomic();
8670
8671 /*
8672 * The generic stuff only does filemap_write_and_wait_range, which
8673 * isn't enough if we've written compressed pages to this area, so
8674 * we need to flush the dirty pages again to make absolutely sure
8675 * that any outstanding dirty pages are on disk.
8676 */
8677 count = iov_iter_count(iter);
8678 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8679 &BTRFS_I(inode)->runtime_flags))
8680 filemap_fdatawrite_range(inode->i_mapping, offset,
8681 offset + count - 1);
8682
8683 if (iov_iter_rw(iter) == WRITE) {
8684 /*
8685 * If the write DIO is beyond the EOF, we need update
8686 * the isize, but it is protected by i_mutex. So we can
8687 * not unlock the i_mutex at this case.
8688 */
8689 if (offset + count <= inode->i_size) {
8690 inode_unlock(inode);
8691 relock = true;
8692 }
8693 ret = btrfs_delalloc_reserve_space(inode, offset, count);
8694 if (ret)
8695 goto out;
8696 dio_data.outstanding_extents = div64_u64(count +
8697 BTRFS_MAX_EXTENT_SIZE - 1,
8698 BTRFS_MAX_EXTENT_SIZE);
8699
8700 /*
8701 * We need to know how many extents we reserved so that we can
8702 * do the accounting properly if we go over the number we
8703 * originally calculated. Abuse current->journal_info for this.
8704 */
8705 dio_data.reserve = round_up(count, root->sectorsize);
8706 dio_data.unsubmitted_oe_range_start = (u64)offset;
8707 dio_data.unsubmitted_oe_range_end = (u64)offset;
8708 current->journal_info = &dio_data;
8709 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8710 &BTRFS_I(inode)->runtime_flags)) {
8711 inode_dio_end(inode);
8712 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8713 wakeup = false;
8714 }
8715
8716 ret = __blockdev_direct_IO(iocb, inode,
8717 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
8718 iter, btrfs_get_blocks_direct, NULL,
8719 btrfs_submit_direct, flags);
8720 if (iov_iter_rw(iter) == WRITE) {
8721 current->journal_info = NULL;
8722 if (ret < 0 && ret != -EIOCBQUEUED) {
8723 if (dio_data.reserve)
8724 btrfs_delalloc_release_space(inode, offset,
8725 dio_data.reserve);
8726 /*
8727 * On error we might have left some ordered extents
8728 * without submitting corresponding bios for them, so
8729 * cleanup them up to avoid other tasks getting them
8730 * and waiting for them to complete forever.
8731 */
8732 if (dio_data.unsubmitted_oe_range_start <
8733 dio_data.unsubmitted_oe_range_end)
8734 btrfs_endio_direct_write_update_ordered(inode,
8735 dio_data.unsubmitted_oe_range_start,
8736 dio_data.unsubmitted_oe_range_end -
8737 dio_data.unsubmitted_oe_range_start,
8738 0);
8739 } else if (ret >= 0 && (size_t)ret < count)
8740 btrfs_delalloc_release_space(inode, offset,
8741 count - (size_t)ret);
8742 }
8743 out:
8744 if (wakeup)
8745 inode_dio_end(inode);
8746 if (relock)
8747 inode_lock(inode);
8748
8749 return ret;
8750 }
8751
8752 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
8753
8754 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8755 __u64 start, __u64 len)
8756 {
8757 int ret;
8758
8759 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8760 if (ret)
8761 return ret;
8762
8763 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
8764 }
8765
8766 int btrfs_readpage(struct file *file, struct page *page)
8767 {
8768 struct extent_io_tree *tree;
8769 tree = &BTRFS_I(page->mapping->host)->io_tree;
8770 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8771 }
8772
8773 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8774 {
8775 struct extent_io_tree *tree;
8776 struct inode *inode = page->mapping->host;
8777 int ret;
8778
8779 if (current->flags & PF_MEMALLOC) {
8780 redirty_page_for_writepage(wbc, page);
8781 unlock_page(page);
8782 return 0;
8783 }
8784
8785 /*
8786 * If we are under memory pressure we will call this directly from the
8787 * VM, we need to make sure we have the inode referenced for the ordered
8788 * extent. If not just return like we didn't do anything.
8789 */
8790 if (!igrab(inode)) {
8791 redirty_page_for_writepage(wbc, page);
8792 return AOP_WRITEPAGE_ACTIVATE;
8793 }
8794 tree = &BTRFS_I(page->mapping->host)->io_tree;
8795 ret = extent_write_full_page(tree, page, btrfs_get_extent, wbc);
8796 btrfs_add_delayed_iput(inode);
8797 return ret;
8798 }
8799
8800 static int btrfs_writepages(struct address_space *mapping,
8801 struct writeback_control *wbc)
8802 {
8803 struct extent_io_tree *tree;
8804
8805 tree = &BTRFS_I(mapping->host)->io_tree;
8806 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
8807 }
8808
8809 static int
8810 btrfs_readpages(struct file *file, struct address_space *mapping,
8811 struct list_head *pages, unsigned nr_pages)
8812 {
8813 struct extent_io_tree *tree;
8814 tree = &BTRFS_I(mapping->host)->io_tree;
8815 return extent_readpages(tree, mapping, pages, nr_pages,
8816 btrfs_get_extent);
8817 }
8818 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8819 {
8820 struct extent_io_tree *tree;
8821 struct extent_map_tree *map;
8822 int ret;
8823
8824 tree = &BTRFS_I(page->mapping->host)->io_tree;
8825 map = &BTRFS_I(page->mapping->host)->extent_tree;
8826 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
8827 if (ret == 1) {
8828 ClearPagePrivate(page);
8829 set_page_private(page, 0);
8830 put_page(page);
8831 }
8832 return ret;
8833 }
8834
8835 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8836 {
8837 if (PageWriteback(page) || PageDirty(page))
8838 return 0;
8839 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
8840 }
8841
8842 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8843 unsigned int length)
8844 {
8845 struct inode *inode = page->mapping->host;
8846 struct extent_io_tree *tree;
8847 struct btrfs_ordered_extent *ordered;
8848 struct extent_state *cached_state = NULL;
8849 u64 page_start = page_offset(page);
8850 u64 page_end = page_start + PAGE_SIZE - 1;
8851 u64 start;
8852 u64 end;
8853 int inode_evicting = inode->i_state & I_FREEING;
8854
8855 /*
8856 * we have the page locked, so new writeback can't start,
8857 * and the dirty bit won't be cleared while we are here.
8858 *
8859 * Wait for IO on this page so that we can safely clear
8860 * the PagePrivate2 bit and do ordered accounting
8861 */
8862 wait_on_page_writeback(page);
8863
8864 tree = &BTRFS_I(inode)->io_tree;
8865 if (offset) {
8866 btrfs_releasepage(page, GFP_NOFS);
8867 return;
8868 }
8869
8870 if (!inode_evicting)
8871 lock_extent_bits(tree, page_start, page_end, &cached_state);
8872 again:
8873 start = page_start;
8874 ordered = btrfs_lookup_ordered_range(inode, start,
8875 page_end - start + 1);
8876 if (ordered) {
8877 end = min(page_end, ordered->file_offset + ordered->len - 1);
8878 /*
8879 * IO on this page will never be started, so we need
8880 * to account for any ordered extents now
8881 */
8882 if (!inode_evicting)
8883 clear_extent_bit(tree, start, end,
8884 EXTENT_DIRTY | EXTENT_DELALLOC |
8885 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8886 EXTENT_DEFRAG, 1, 0, &cached_state,
8887 GFP_NOFS);
8888 /*
8889 * whoever cleared the private bit is responsible
8890 * for the finish_ordered_io
8891 */
8892 if (TestClearPagePrivate2(page)) {
8893 struct btrfs_ordered_inode_tree *tree;
8894 u64 new_len;
8895
8896 tree = &BTRFS_I(inode)->ordered_tree;
8897
8898 spin_lock_irq(&tree->lock);
8899 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8900 new_len = start - ordered->file_offset;
8901 if (new_len < ordered->truncated_len)
8902 ordered->truncated_len = new_len;
8903 spin_unlock_irq(&tree->lock);
8904
8905 if (btrfs_dec_test_ordered_pending(inode, &ordered,
8906 start,
8907 end - start + 1, 1))
8908 btrfs_finish_ordered_io(ordered);
8909 }
8910 btrfs_put_ordered_extent(ordered);
8911 if (!inode_evicting) {
8912 cached_state = NULL;
8913 lock_extent_bits(tree, start, end,
8914 &cached_state);
8915 }
8916
8917 start = end + 1;
8918 if (start < page_end)
8919 goto again;
8920 }
8921
8922 /*
8923 * Qgroup reserved space handler
8924 * Page here will be either
8925 * 1) Already written to disk
8926 * In this case, its reserved space is released from data rsv map
8927 * and will be freed by delayed_ref handler finally.
8928 * So even we call qgroup_free_data(), it won't decrease reserved
8929 * space.
8930 * 2) Not written to disk
8931 * This means the reserved space should be freed here. However,
8932 * if a truncate invalidates the page (by clearing PageDirty)
8933 * and the page is accounted for while allocating extent
8934 * in btrfs_check_data_free_space() we let delayed_ref to
8935 * free the entire extent.
8936 */
8937 if (PageDirty(page))
8938 btrfs_qgroup_free_data(inode, page_start, PAGE_SIZE);
8939 if (!inode_evicting) {
8940 clear_extent_bit(tree, page_start, page_end,
8941 EXTENT_LOCKED | EXTENT_DIRTY |
8942 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
8943 EXTENT_DEFRAG, 1, 1,
8944 &cached_state, GFP_NOFS);
8945
8946 __btrfs_releasepage(page, GFP_NOFS);
8947 }
8948
8949 ClearPageChecked(page);
8950 if (PagePrivate(page)) {
8951 ClearPagePrivate(page);
8952 set_page_private(page, 0);
8953 put_page(page);
8954 }
8955 }
8956
8957 /*
8958 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
8959 * called from a page fault handler when a page is first dirtied. Hence we must
8960 * be careful to check for EOF conditions here. We set the page up correctly
8961 * for a written page which means we get ENOSPC checking when writing into
8962 * holes and correct delalloc and unwritten extent mapping on filesystems that
8963 * support these features.
8964 *
8965 * We are not allowed to take the i_mutex here so we have to play games to
8966 * protect against truncate races as the page could now be beyond EOF. Because
8967 * vmtruncate() writes the inode size before removing pages, once we have the
8968 * page lock we can determine safely if the page is beyond EOF. If it is not
8969 * beyond EOF, then the page is guaranteed safe against truncation until we
8970 * unlock the page.
8971 */
8972 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
8973 {
8974 struct page *page = vmf->page;
8975 struct inode *inode = file_inode(vma->vm_file);
8976 struct btrfs_root *root = BTRFS_I(inode)->root;
8977 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8978 struct btrfs_ordered_extent *ordered;
8979 struct extent_state *cached_state = NULL;
8980 char *kaddr;
8981 unsigned long zero_start;
8982 loff_t size;
8983 int ret;
8984 int reserved = 0;
8985 u64 reserved_space;
8986 u64 page_start;
8987 u64 page_end;
8988 u64 end;
8989
8990 reserved_space = PAGE_SIZE;
8991
8992 sb_start_pagefault(inode->i_sb);
8993 page_start = page_offset(page);
8994 page_end = page_start + PAGE_SIZE - 1;
8995 end = page_end;
8996
8997 /*
8998 * Reserving delalloc space after obtaining the page lock can lead to
8999 * deadlock. For example, if a dirty page is locked by this function
9000 * and the call to btrfs_delalloc_reserve_space() ends up triggering
9001 * dirty page write out, then the btrfs_writepage() function could
9002 * end up waiting indefinitely to get a lock on the page currently
9003 * being processed by btrfs_page_mkwrite() function.
9004 */
9005 ret = btrfs_delalloc_reserve_space(inode, page_start,
9006 reserved_space);
9007 if (!ret) {
9008 ret = file_update_time(vma->vm_file);
9009 reserved = 1;
9010 }
9011 if (ret) {
9012 if (ret == -ENOMEM)
9013 ret = VM_FAULT_OOM;
9014 else /* -ENOSPC, -EIO, etc */
9015 ret = VM_FAULT_SIGBUS;
9016 if (reserved)
9017 goto out;
9018 goto out_noreserve;
9019 }
9020
9021 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
9022 again:
9023 lock_page(page);
9024 size = i_size_read(inode);
9025
9026 if ((page->mapping != inode->i_mapping) ||
9027 (page_start >= size)) {
9028 /* page got truncated out from underneath us */
9029 goto out_unlock;
9030 }
9031 wait_on_page_writeback(page);
9032
9033 lock_extent_bits(io_tree, page_start, page_end, &cached_state);
9034 set_page_extent_mapped(page);
9035
9036 /*
9037 * we can't set the delalloc bits if there are pending ordered
9038 * extents. Drop our locks and wait for them to finish
9039 */
9040 ordered = btrfs_lookup_ordered_range(inode, page_start, page_end);
9041 if (ordered) {
9042 unlock_extent_cached(io_tree, page_start, page_end,
9043 &cached_state, GFP_NOFS);
9044 unlock_page(page);
9045 btrfs_start_ordered_extent(inode, ordered, 1);
9046 btrfs_put_ordered_extent(ordered);
9047 goto again;
9048 }
9049
9050 if (page->index == ((size - 1) >> PAGE_SHIFT)) {
9051 reserved_space = round_up(size - page_start, root->sectorsize);
9052 if (reserved_space < PAGE_SIZE) {
9053 end = page_start + reserved_space - 1;
9054 spin_lock(&BTRFS_I(inode)->lock);
9055 BTRFS_I(inode)->outstanding_extents++;
9056 spin_unlock(&BTRFS_I(inode)->lock);
9057 btrfs_delalloc_release_space(inode, page_start,
9058 PAGE_SIZE - reserved_space);
9059 }
9060 }
9061
9062 /*
9063 * XXX - page_mkwrite gets called every time the page is dirtied, even
9064 * if it was already dirty, so for space accounting reasons we need to
9065 * clear any delalloc bits for the range we are fixing to save. There
9066 * is probably a better way to do this, but for now keep consistent with
9067 * prepare_pages in the normal write path.
9068 */
9069 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
9070 EXTENT_DIRTY | EXTENT_DELALLOC |
9071 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
9072 0, 0, &cached_state, GFP_NOFS);
9073
9074 ret = btrfs_set_extent_delalloc(inode, page_start, end,
9075 &cached_state, 0);
9076 if (ret) {
9077 unlock_extent_cached(io_tree, page_start, page_end,
9078 &cached_state, GFP_NOFS);
9079 ret = VM_FAULT_SIGBUS;
9080 goto out_unlock;
9081 }
9082 ret = 0;
9083
9084 /* page is wholly or partially inside EOF */
9085 if (page_start + PAGE_SIZE > size)
9086 zero_start = size & ~PAGE_MASK;
9087 else
9088 zero_start = PAGE_SIZE;
9089
9090 if (zero_start != PAGE_SIZE) {
9091 kaddr = kmap(page);
9092 memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start);
9093 flush_dcache_page(page);
9094 kunmap(page);
9095 }
9096 ClearPageChecked(page);
9097 set_page_dirty(page);
9098 SetPageUptodate(page);
9099
9100 BTRFS_I(inode)->last_trans = root->fs_info->generation;
9101 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
9102 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
9103
9104 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
9105
9106 out_unlock:
9107 if (!ret) {
9108 sb_end_pagefault(inode->i_sb);
9109 return VM_FAULT_LOCKED;
9110 }
9111 unlock_page(page);
9112 out:
9113 btrfs_delalloc_release_space(inode, page_start, reserved_space);
9114 out_noreserve:
9115 sb_end_pagefault(inode->i_sb);
9116 return ret;
9117 }
9118
9119 static int btrfs_truncate(struct inode *inode)
9120 {
9121 struct btrfs_root *root = BTRFS_I(inode)->root;
9122 struct btrfs_block_rsv *rsv;
9123 int ret = 0;
9124 int err = 0;
9125 struct btrfs_trans_handle *trans;
9126 u64 mask = root->sectorsize - 1;
9127 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
9128
9129 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
9130 (u64)-1);
9131 if (ret)
9132 return ret;
9133
9134 /*
9135 * Yes ladies and gentlemen, this is indeed ugly. The fact is we have
9136 * 3 things going on here
9137 *
9138 * 1) We need to reserve space for our orphan item and the space to
9139 * delete our orphan item. Lord knows we don't want to have a dangling
9140 * orphan item because we didn't reserve space to remove it.
9141 *
9142 * 2) We need to reserve space to update our inode.
9143 *
9144 * 3) We need to have something to cache all the space that is going to
9145 * be free'd up by the truncate operation, but also have some slack
9146 * space reserved in case it uses space during the truncate (thank you
9147 * very much snapshotting).
9148 *
9149 * And we need these to all be separate. The fact is we can use a lot of
9150 * space doing the truncate, and we have no earthly idea how much space
9151 * we will use, so we need the truncate reservation to be separate so it
9152 * doesn't end up using space reserved for updating the inode or
9153 * removing the orphan item. We also need to be able to stop the
9154 * transaction and start a new one, which means we need to be able to
9155 * update the inode several times, and we have no idea of knowing how
9156 * many times that will be, so we can't just reserve 1 item for the
9157 * entirety of the operation, so that has to be done separately as well.
9158 * Then there is the orphan item, which does indeed need to be held on
9159 * to for the whole operation, and we need nobody to touch this reserved
9160 * space except the orphan code.
9161 *
9162 * So that leaves us with
9163 *
9164 * 1) root->orphan_block_rsv - for the orphan deletion.
9165 * 2) rsv - for the truncate reservation, which we will steal from the
9166 * transaction reservation.
9167 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
9168 * updating the inode.
9169 */
9170 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
9171 if (!rsv)
9172 return -ENOMEM;
9173 rsv->size = min_size;
9174 rsv->failfast = 1;
9175
9176 /*
9177 * 1 for the truncate slack space
9178 * 1 for updating the inode.
9179 */
9180 trans = btrfs_start_transaction(root, 2);
9181 if (IS_ERR(trans)) {
9182 err = PTR_ERR(trans);
9183 goto out;
9184 }
9185
9186 /* Migrate the slack space for the truncate to our reserve */
9187 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
9188 min_size, 0);
9189 BUG_ON(ret);
9190
9191 /*
9192 * So if we truncate and then write and fsync we normally would just
9193 * write the extents that changed, which is a problem if we need to
9194 * first truncate that entire inode. So set this flag so we write out
9195 * all of the extents in the inode to the sync log so we're completely
9196 * safe.
9197 */
9198 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
9199 trans->block_rsv = rsv;
9200
9201 while (1) {
9202 ret = btrfs_truncate_inode_items(trans, root, inode,
9203 inode->i_size,
9204 BTRFS_EXTENT_DATA_KEY);
9205 if (ret != -ENOSPC && ret != -EAGAIN) {
9206 err = ret;
9207 break;
9208 }
9209
9210 trans->block_rsv = &root->fs_info->trans_block_rsv;
9211 ret = btrfs_update_inode(trans, root, inode);
9212 if (ret) {
9213 err = ret;
9214 break;
9215 }
9216
9217 btrfs_end_transaction(trans, root);
9218 btrfs_btree_balance_dirty(root);
9219
9220 trans = btrfs_start_transaction(root, 2);
9221 if (IS_ERR(trans)) {
9222 ret = err = PTR_ERR(trans);
9223 trans = NULL;
9224 break;
9225 }
9226
9227 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
9228 rsv, min_size, 0);
9229 BUG_ON(ret); /* shouldn't happen */
9230 trans->block_rsv = rsv;
9231 }
9232
9233 if (ret == 0 && inode->i_nlink > 0) {
9234 trans->block_rsv = root->orphan_block_rsv;
9235 ret = btrfs_orphan_del(trans, inode);
9236 if (ret)
9237 err = ret;
9238 }
9239
9240 if (trans) {
9241 trans->block_rsv = &root->fs_info->trans_block_rsv;
9242 ret = btrfs_update_inode(trans, root, inode);
9243 if (ret && !err)
9244 err = ret;
9245
9246 ret = btrfs_end_transaction(trans, root);
9247 btrfs_btree_balance_dirty(root);
9248 }
9249 out:
9250 btrfs_free_block_rsv(root, rsv);
9251
9252 if (ret && !err)
9253 err = ret;
9254
9255 return err;
9256 }
9257
9258 /*
9259 * create a new subvolume directory/inode (helper for the ioctl).
9260 */
9261 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
9262 struct btrfs_root *new_root,
9263 struct btrfs_root *parent_root,
9264 u64 new_dirid)
9265 {
9266 struct inode *inode;
9267 int err;
9268 u64 index = 0;
9269
9270 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
9271 new_dirid, new_dirid,
9272 S_IFDIR | (~current_umask() & S_IRWXUGO),
9273 &index);
9274 if (IS_ERR(inode))
9275 return PTR_ERR(inode);
9276 inode->i_op = &btrfs_dir_inode_operations;
9277 inode->i_fop = &btrfs_dir_file_operations;
9278
9279 set_nlink(inode, 1);
9280 btrfs_i_size_write(inode, 0);
9281 unlock_new_inode(inode);
9282
9283 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
9284 if (err)
9285 btrfs_err(new_root->fs_info,
9286 "error inheriting subvolume %llu properties: %d",
9287 new_root->root_key.objectid, err);
9288
9289 err = btrfs_update_inode(trans, new_root, inode);
9290
9291 iput(inode);
9292 return err;
9293 }
9294
9295 struct inode *btrfs_alloc_inode(struct super_block *sb)
9296 {
9297 struct btrfs_inode *ei;
9298 struct inode *inode;
9299
9300 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
9301 if (!ei)
9302 return NULL;
9303
9304 ei->root = NULL;
9305 ei->generation = 0;
9306 ei->last_trans = 0;
9307 ei->last_sub_trans = 0;
9308 ei->logged_trans = 0;
9309 ei->delalloc_bytes = 0;
9310 ei->defrag_bytes = 0;
9311 ei->disk_i_size = 0;
9312 ei->flags = 0;
9313 ei->csum_bytes = 0;
9314 ei->index_cnt = (u64)-1;
9315 ei->dir_index = 0;
9316 ei->last_unlink_trans = 0;
9317 ei->last_log_commit = 0;
9318 ei->delayed_iput_count = 0;
9319
9320 spin_lock_init(&ei->lock);
9321 ei->outstanding_extents = 0;
9322 ei->reserved_extents = 0;
9323
9324 ei->runtime_flags = 0;
9325 ei->force_compress = BTRFS_COMPRESS_NONE;
9326
9327 ei->delayed_node = NULL;
9328
9329 ei->i_otime.tv_sec = 0;
9330 ei->i_otime.tv_nsec = 0;
9331
9332 inode = &ei->vfs_inode;
9333 extent_map_tree_init(&ei->extent_tree);
9334 extent_io_tree_init(&ei->io_tree, &inode->i_data);
9335 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
9336 ei->io_tree.track_uptodate = 1;
9337 ei->io_failure_tree.track_uptodate = 1;
9338 atomic_set(&ei->sync_writers, 0);
9339 mutex_init(&ei->log_mutex);
9340 mutex_init(&ei->delalloc_mutex);
9341 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
9342 INIT_LIST_HEAD(&ei->delalloc_inodes);
9343 INIT_LIST_HEAD(&ei->delayed_iput);
9344 RB_CLEAR_NODE(&ei->rb_node);
9345 init_rwsem(&ei->dio_sem);
9346
9347 return inode;
9348 }
9349
9350 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
9351 void btrfs_test_destroy_inode(struct inode *inode)
9352 {
9353 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
9354 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9355 }
9356 #endif
9357
9358 static void btrfs_i_callback(struct rcu_head *head)
9359 {
9360 struct inode *inode = container_of(head, struct inode, i_rcu);
9361 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9362 }
9363
9364 void btrfs_destroy_inode(struct inode *inode)
9365 {
9366 struct btrfs_ordered_extent *ordered;
9367 struct btrfs_root *root = BTRFS_I(inode)->root;
9368
9369 WARN_ON(!hlist_empty(&inode->i_dentry));
9370 WARN_ON(inode->i_data.nrpages);
9371 WARN_ON(BTRFS_I(inode)->outstanding_extents);
9372 WARN_ON(BTRFS_I(inode)->reserved_extents);
9373 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
9374 WARN_ON(BTRFS_I(inode)->csum_bytes);
9375 WARN_ON(BTRFS_I(inode)->defrag_bytes);
9376
9377 /*
9378 * This can happen where we create an inode, but somebody else also
9379 * created the same inode and we need to destroy the one we already
9380 * created.
9381 */
9382 if (!root)
9383 goto free;
9384
9385 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
9386 &BTRFS_I(inode)->runtime_flags)) {
9387 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
9388 btrfs_ino(inode));
9389 atomic_dec(&root->orphan_inodes);
9390 }
9391
9392 while (1) {
9393 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
9394 if (!ordered)
9395 break;
9396 else {
9397 btrfs_err(root->fs_info,
9398 "found ordered extent %llu %llu on inode cleanup",
9399 ordered->file_offset, ordered->len);
9400 btrfs_remove_ordered_extent(inode, ordered);
9401 btrfs_put_ordered_extent(ordered);
9402 btrfs_put_ordered_extent(ordered);
9403 }
9404 }
9405 btrfs_qgroup_check_reserved_leak(inode);
9406 inode_tree_del(inode);
9407 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
9408 free:
9409 call_rcu(&inode->i_rcu, btrfs_i_callback);
9410 }
9411
9412 int btrfs_drop_inode(struct inode *inode)
9413 {
9414 struct btrfs_root *root = BTRFS_I(inode)->root;
9415
9416 if (root == NULL)
9417 return 1;
9418
9419 /* the snap/subvol tree is on deleting */
9420 if (btrfs_root_refs(&root->root_item) == 0)
9421 return 1;
9422 else
9423 return generic_drop_inode(inode);
9424 }
9425
9426 static void init_once(void *foo)
9427 {
9428 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
9429
9430 inode_init_once(&ei->vfs_inode);
9431 }
9432
9433 void btrfs_destroy_cachep(void)
9434 {
9435 /*
9436 * Make sure all delayed rcu free inodes are flushed before we
9437 * destroy cache.
9438 */
9439 rcu_barrier();
9440 kmem_cache_destroy(btrfs_inode_cachep);
9441 kmem_cache_destroy(btrfs_trans_handle_cachep);
9442 kmem_cache_destroy(btrfs_transaction_cachep);
9443 kmem_cache_destroy(btrfs_path_cachep);
9444 kmem_cache_destroy(btrfs_free_space_cachep);
9445 }
9446
9447 int btrfs_init_cachep(void)
9448 {
9449 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
9450 sizeof(struct btrfs_inode), 0,
9451 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
9452 init_once);
9453 if (!btrfs_inode_cachep)
9454 goto fail;
9455
9456 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
9457 sizeof(struct btrfs_trans_handle), 0,
9458 SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
9459 if (!btrfs_trans_handle_cachep)
9460 goto fail;
9461
9462 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
9463 sizeof(struct btrfs_transaction), 0,
9464 SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
9465 if (!btrfs_transaction_cachep)
9466 goto fail;
9467
9468 btrfs_path_cachep = kmem_cache_create("btrfs_path",
9469 sizeof(struct btrfs_path), 0,
9470 SLAB_MEM_SPREAD, NULL);
9471 if (!btrfs_path_cachep)
9472 goto fail;
9473
9474 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
9475 sizeof(struct btrfs_free_space), 0,
9476 SLAB_MEM_SPREAD, NULL);
9477 if (!btrfs_free_space_cachep)
9478 goto fail;
9479
9480 return 0;
9481 fail:
9482 btrfs_destroy_cachep();
9483 return -ENOMEM;
9484 }
9485
9486 static int btrfs_getattr(struct vfsmount *mnt,
9487 struct dentry *dentry, struct kstat *stat)
9488 {
9489 u64 delalloc_bytes;
9490 struct inode *inode = d_inode(dentry);
9491 u32 blocksize = inode->i_sb->s_blocksize;
9492
9493 generic_fillattr(inode, stat);
9494 stat->dev = BTRFS_I(inode)->root->anon_dev;
9495
9496 spin_lock(&BTRFS_I(inode)->lock);
9497 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
9498 spin_unlock(&BTRFS_I(inode)->lock);
9499 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9500 ALIGN(delalloc_bytes, blocksize)) >> 9;
9501 return 0;
9502 }
9503
9504 static int btrfs_rename_exchange(struct inode *old_dir,
9505 struct dentry *old_dentry,
9506 struct inode *new_dir,
9507 struct dentry *new_dentry)
9508 {
9509 struct btrfs_trans_handle *trans;
9510 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9511 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9512 struct inode *new_inode = new_dentry->d_inode;
9513 struct inode *old_inode = old_dentry->d_inode;
9514 struct timespec ctime = current_time(old_inode);
9515 struct dentry *parent;
9516 u64 old_ino = btrfs_ino(old_inode);
9517 u64 new_ino = btrfs_ino(new_inode);
9518 u64 old_idx = 0;
9519 u64 new_idx = 0;
9520 u64 root_objectid;
9521 int ret;
9522 bool root_log_pinned = false;
9523 bool dest_log_pinned = false;
9524
9525 /* we only allow rename subvolume link between subvolumes */
9526 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9527 return -EXDEV;
9528
9529 /* close the race window with snapshot create/destroy ioctl */
9530 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9531 down_read(&root->fs_info->subvol_sem);
9532 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9533 down_read(&dest->fs_info->subvol_sem);
9534
9535 /*
9536 * We want to reserve the absolute worst case amount of items. So if
9537 * both inodes are subvols and we need to unlink them then that would
9538 * require 4 item modifications, but if they are both normal inodes it
9539 * would require 5 item modifications, so we'll assume their normal
9540 * inodes. So 5 * 2 is 10, plus 2 for the new links, so 12 total items
9541 * should cover the worst case number of items we'll modify.
9542 */
9543 trans = btrfs_start_transaction(root, 12);
9544 if (IS_ERR(trans)) {
9545 ret = PTR_ERR(trans);
9546 goto out_notrans;
9547 }
9548
9549 /*
9550 * We need to find a free sequence number both in the source and
9551 * in the destination directory for the exchange.
9552 */
9553 ret = btrfs_set_inode_index(new_dir, &old_idx);
9554 if (ret)
9555 goto out_fail;
9556 ret = btrfs_set_inode_index(old_dir, &new_idx);
9557 if (ret)
9558 goto out_fail;
9559
9560 BTRFS_I(old_inode)->dir_index = 0ULL;
9561 BTRFS_I(new_inode)->dir_index = 0ULL;
9562
9563 /* Reference for the source. */
9564 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9565 /* force full log commit if subvolume involved. */
9566 btrfs_set_log_full_commit(root->fs_info, trans);
9567 } else {
9568 btrfs_pin_log_trans(root);
9569 root_log_pinned = true;
9570 ret = btrfs_insert_inode_ref(trans, dest,
9571 new_dentry->d_name.name,
9572 new_dentry->d_name.len,
9573 old_ino,
9574 btrfs_ino(new_dir), old_idx);
9575 if (ret)
9576 goto out_fail;
9577 }
9578
9579 /* And now for the dest. */
9580 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9581 /* force full log commit if subvolume involved. */
9582 btrfs_set_log_full_commit(dest->fs_info, trans);
9583 } else {
9584 btrfs_pin_log_trans(dest);
9585 dest_log_pinned = true;
9586 ret = btrfs_insert_inode_ref(trans, root,
9587 old_dentry->d_name.name,
9588 old_dentry->d_name.len,
9589 new_ino,
9590 btrfs_ino(old_dir), new_idx);
9591 if (ret)
9592 goto out_fail;
9593 }
9594
9595 /* Update inode version and ctime/mtime. */
9596 inode_inc_iversion(old_dir);
9597 inode_inc_iversion(new_dir);
9598 inode_inc_iversion(old_inode);
9599 inode_inc_iversion(new_inode);
9600 old_dir->i_ctime = old_dir->i_mtime = ctime;
9601 new_dir->i_ctime = new_dir->i_mtime = ctime;
9602 old_inode->i_ctime = ctime;
9603 new_inode->i_ctime = ctime;
9604
9605 if (old_dentry->d_parent != new_dentry->d_parent) {
9606 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
9607 btrfs_record_unlink_dir(trans, new_dir, new_inode, 1);
9608 }
9609
9610 /* src is a subvolume */
9611 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9612 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9613 ret = btrfs_unlink_subvol(trans, root, old_dir,
9614 root_objectid,
9615 old_dentry->d_name.name,
9616 old_dentry->d_name.len);
9617 } else { /* src is an inode */
9618 ret = __btrfs_unlink_inode(trans, root, old_dir,
9619 old_dentry->d_inode,
9620 old_dentry->d_name.name,
9621 old_dentry->d_name.len);
9622 if (!ret)
9623 ret = btrfs_update_inode(trans, root, old_inode);
9624 }
9625 if (ret) {
9626 btrfs_abort_transaction(trans, ret);
9627 goto out_fail;
9628 }
9629
9630 /* dest is a subvolume */
9631 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9632 root_objectid = BTRFS_I(new_inode)->root->root_key.objectid;
9633 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9634 root_objectid,
9635 new_dentry->d_name.name,
9636 new_dentry->d_name.len);
9637 } else { /* dest is an inode */
9638 ret = __btrfs_unlink_inode(trans, dest, new_dir,
9639 new_dentry->d_inode,
9640 new_dentry->d_name.name,
9641 new_dentry->d_name.len);
9642 if (!ret)
9643 ret = btrfs_update_inode(trans, dest, new_inode);
9644 }
9645 if (ret) {
9646 btrfs_abort_transaction(trans, ret);
9647 goto out_fail;
9648 }
9649
9650 ret = btrfs_add_link(trans, new_dir, old_inode,
9651 new_dentry->d_name.name,
9652 new_dentry->d_name.len, 0, old_idx);
9653 if (ret) {
9654 btrfs_abort_transaction(trans, ret);
9655 goto out_fail;
9656 }
9657
9658 ret = btrfs_add_link(trans, old_dir, new_inode,
9659 old_dentry->d_name.name,
9660 old_dentry->d_name.len, 0, new_idx);
9661 if (ret) {
9662 btrfs_abort_transaction(trans, ret);
9663 goto out_fail;
9664 }
9665
9666 if (old_inode->i_nlink == 1)
9667 BTRFS_I(old_inode)->dir_index = old_idx;
9668 if (new_inode->i_nlink == 1)
9669 BTRFS_I(new_inode)->dir_index = new_idx;
9670
9671 if (root_log_pinned) {
9672 parent = new_dentry->d_parent;
9673 btrfs_log_new_name(trans, old_inode, old_dir, parent);
9674 btrfs_end_log_trans(root);
9675 root_log_pinned = false;
9676 }
9677 if (dest_log_pinned) {
9678 parent = old_dentry->d_parent;
9679 btrfs_log_new_name(trans, new_inode, new_dir, parent);
9680 btrfs_end_log_trans(dest);
9681 dest_log_pinned = false;
9682 }
9683 out_fail:
9684 /*
9685 * If we have pinned a log and an error happened, we unpin tasks
9686 * trying to sync the log and force them to fallback to a transaction
9687 * commit if the log currently contains any of the inodes involved in
9688 * this rename operation (to ensure we do not persist a log with an
9689 * inconsistent state for any of these inodes or leading to any
9690 * inconsistencies when replayed). If the transaction was aborted, the
9691 * abortion reason is propagated to userspace when attempting to commit
9692 * the transaction. If the log does not contain any of these inodes, we
9693 * allow the tasks to sync it.
9694 */
9695 if (ret && (root_log_pinned || dest_log_pinned)) {
9696 if (btrfs_inode_in_log(old_dir, root->fs_info->generation) ||
9697 btrfs_inode_in_log(new_dir, root->fs_info->generation) ||
9698 btrfs_inode_in_log(old_inode, root->fs_info->generation) ||
9699 (new_inode &&
9700 btrfs_inode_in_log(new_inode, root->fs_info->generation)))
9701 btrfs_set_log_full_commit(root->fs_info, trans);
9702
9703 if (root_log_pinned) {
9704 btrfs_end_log_trans(root);
9705 root_log_pinned = false;
9706 }
9707 if (dest_log_pinned) {
9708 btrfs_end_log_trans(dest);
9709 dest_log_pinned = false;
9710 }
9711 }
9712 ret = btrfs_end_transaction(trans, root);
9713 out_notrans:
9714 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9715 up_read(&dest->fs_info->subvol_sem);
9716 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9717 up_read(&root->fs_info->subvol_sem);
9718
9719 return ret;
9720 }
9721
9722 static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans,
9723 struct btrfs_root *root,
9724 struct inode *dir,
9725 struct dentry *dentry)
9726 {
9727 int ret;
9728 struct inode *inode;
9729 u64 objectid;
9730 u64 index;
9731
9732 ret = btrfs_find_free_ino(root, &objectid);
9733 if (ret)
9734 return ret;
9735
9736 inode = btrfs_new_inode(trans, root, dir,
9737 dentry->d_name.name,
9738 dentry->d_name.len,
9739 btrfs_ino(dir),
9740 objectid,
9741 S_IFCHR | WHITEOUT_MODE,
9742 &index);
9743
9744 if (IS_ERR(inode)) {
9745 ret = PTR_ERR(inode);
9746 return ret;
9747 }
9748
9749 inode->i_op = &btrfs_special_inode_operations;
9750 init_special_inode(inode, inode->i_mode,
9751 WHITEOUT_DEV);
9752
9753 ret = btrfs_init_inode_security(trans, inode, dir,
9754 &dentry->d_name);
9755 if (ret)
9756 goto out;
9757
9758 ret = btrfs_add_nondir(trans, dir, dentry,
9759 inode, 0, index);
9760 if (ret)
9761 goto out;
9762
9763 ret = btrfs_update_inode(trans, root, inode);
9764 out:
9765 unlock_new_inode(inode);
9766 if (ret)
9767 inode_dec_link_count(inode);
9768 iput(inode);
9769
9770 return ret;
9771 }
9772
9773 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9774 struct inode *new_dir, struct dentry *new_dentry,
9775 unsigned int flags)
9776 {
9777 struct btrfs_trans_handle *trans;
9778 unsigned int trans_num_items;
9779 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9780 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9781 struct inode *new_inode = d_inode(new_dentry);
9782 struct inode *old_inode = d_inode(old_dentry);
9783 u64 index = 0;
9784 u64 root_objectid;
9785 int ret;
9786 u64 old_ino = btrfs_ino(old_inode);
9787 bool log_pinned = false;
9788
9789 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9790 return -EPERM;
9791
9792 /* we only allow rename subvolume link between subvolumes */
9793 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9794 return -EXDEV;
9795
9796 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9797 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
9798 return -ENOTEMPTY;
9799
9800 if (S_ISDIR(old_inode->i_mode) && new_inode &&
9801 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9802 return -ENOTEMPTY;
9803
9804
9805 /* check for collisions, even if the name isn't there */
9806 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9807 new_dentry->d_name.name,
9808 new_dentry->d_name.len);
9809
9810 if (ret) {
9811 if (ret == -EEXIST) {
9812 /* we shouldn't get
9813 * eexist without a new_inode */
9814 if (WARN_ON(!new_inode)) {
9815 return ret;
9816 }
9817 } else {
9818 /* maybe -EOVERFLOW */
9819 return ret;
9820 }
9821 }
9822 ret = 0;
9823
9824 /*
9825 * we're using rename to replace one file with another. Start IO on it
9826 * now so we don't add too much work to the end of the transaction
9827 */
9828 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9829 filemap_flush(old_inode->i_mapping);
9830
9831 /* close the racy window with snapshot create/destroy ioctl */
9832 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9833 down_read(&root->fs_info->subvol_sem);
9834 /*
9835 * We want to reserve the absolute worst case amount of items. So if
9836 * both inodes are subvols and we need to unlink them then that would
9837 * require 4 item modifications, but if they are both normal inodes it
9838 * would require 5 item modifications, so we'll assume they are normal
9839 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
9840 * should cover the worst case number of items we'll modify.
9841 * If our rename has the whiteout flag, we need more 5 units for the
9842 * new inode (1 inode item, 1 inode ref, 2 dir items and 1 xattr item
9843 * when selinux is enabled).
9844 */
9845 trans_num_items = 11;
9846 if (flags & RENAME_WHITEOUT)
9847 trans_num_items += 5;
9848 trans = btrfs_start_transaction(root, trans_num_items);
9849 if (IS_ERR(trans)) {
9850 ret = PTR_ERR(trans);
9851 goto out_notrans;
9852 }
9853
9854 if (dest != root)
9855 btrfs_record_root_in_trans(trans, dest);
9856
9857 ret = btrfs_set_inode_index(new_dir, &index);
9858 if (ret)
9859 goto out_fail;
9860
9861 BTRFS_I(old_inode)->dir_index = 0ULL;
9862 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9863 /* force full log commit if subvolume involved. */
9864 btrfs_set_log_full_commit(root->fs_info, trans);
9865 } else {
9866 btrfs_pin_log_trans(root);
9867 log_pinned = true;
9868 ret = btrfs_insert_inode_ref(trans, dest,
9869 new_dentry->d_name.name,
9870 new_dentry->d_name.len,
9871 old_ino,
9872 btrfs_ino(new_dir), index);
9873 if (ret)
9874 goto out_fail;
9875 }
9876
9877 inode_inc_iversion(old_dir);
9878 inode_inc_iversion(new_dir);
9879 inode_inc_iversion(old_inode);
9880 old_dir->i_ctime = old_dir->i_mtime =
9881 new_dir->i_ctime = new_dir->i_mtime =
9882 old_inode->i_ctime = current_time(old_dir);
9883
9884 if (old_dentry->d_parent != new_dentry->d_parent)
9885 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
9886
9887 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9888 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9889 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
9890 old_dentry->d_name.name,
9891 old_dentry->d_name.len);
9892 } else {
9893 ret = __btrfs_unlink_inode(trans, root, old_dir,
9894 d_inode(old_dentry),
9895 old_dentry->d_name.name,
9896 old_dentry->d_name.len);
9897 if (!ret)
9898 ret = btrfs_update_inode(trans, root, old_inode);
9899 }
9900 if (ret) {
9901 btrfs_abort_transaction(trans, ret);
9902 goto out_fail;
9903 }
9904
9905 if (new_inode) {
9906 inode_inc_iversion(new_inode);
9907 new_inode->i_ctime = current_time(new_inode);
9908 if (unlikely(btrfs_ino(new_inode) ==
9909 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
9910 root_objectid = BTRFS_I(new_inode)->location.objectid;
9911 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9912 root_objectid,
9913 new_dentry->d_name.name,
9914 new_dentry->d_name.len);
9915 BUG_ON(new_inode->i_nlink == 0);
9916 } else {
9917 ret = btrfs_unlink_inode(trans, dest, new_dir,
9918 d_inode(new_dentry),
9919 new_dentry->d_name.name,
9920 new_dentry->d_name.len);
9921 }
9922 if (!ret && new_inode->i_nlink == 0)
9923 ret = btrfs_orphan_add(trans, d_inode(new_dentry));
9924 if (ret) {
9925 btrfs_abort_transaction(trans, ret);
9926 goto out_fail;
9927 }
9928 }
9929
9930 ret = btrfs_add_link(trans, new_dir, old_inode,
9931 new_dentry->d_name.name,
9932 new_dentry->d_name.len, 0, index);
9933 if (ret) {
9934 btrfs_abort_transaction(trans, ret);
9935 goto out_fail;
9936 }
9937
9938 if (old_inode->i_nlink == 1)
9939 BTRFS_I(old_inode)->dir_index = index;
9940
9941 if (log_pinned) {
9942 struct dentry *parent = new_dentry->d_parent;
9943
9944 btrfs_log_new_name(trans, old_inode, old_dir, parent);
9945 btrfs_end_log_trans(root);
9946 log_pinned = false;
9947 }
9948
9949 if (flags & RENAME_WHITEOUT) {
9950 ret = btrfs_whiteout_for_rename(trans, root, old_dir,
9951 old_dentry);
9952
9953 if (ret) {
9954 btrfs_abort_transaction(trans, ret);
9955 goto out_fail;
9956 }
9957 }
9958 out_fail:
9959 /*
9960 * If we have pinned the log and an error happened, we unpin tasks
9961 * trying to sync the log and force them to fallback to a transaction
9962 * commit if the log currently contains any of the inodes involved in
9963 * this rename operation (to ensure we do not persist a log with an
9964 * inconsistent state for any of these inodes or leading to any
9965 * inconsistencies when replayed). If the transaction was aborted, the
9966 * abortion reason is propagated to userspace when attempting to commit
9967 * the transaction. If the log does not contain any of these inodes, we
9968 * allow the tasks to sync it.
9969 */
9970 if (ret && log_pinned) {
9971 if (btrfs_inode_in_log(old_dir, root->fs_info->generation) ||
9972 btrfs_inode_in_log(new_dir, root->fs_info->generation) ||
9973 btrfs_inode_in_log(old_inode, root->fs_info->generation) ||
9974 (new_inode &&
9975 btrfs_inode_in_log(new_inode, root->fs_info->generation)))
9976 btrfs_set_log_full_commit(root->fs_info, trans);
9977
9978 btrfs_end_log_trans(root);
9979 log_pinned = false;
9980 }
9981 btrfs_end_transaction(trans, root);
9982 out_notrans:
9983 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9984 up_read(&root->fs_info->subvol_sem);
9985
9986 return ret;
9987 }
9988
9989 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
9990 struct inode *new_dir, struct dentry *new_dentry,
9991 unsigned int flags)
9992 {
9993 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
9994 return -EINVAL;
9995
9996 if (flags & RENAME_EXCHANGE)
9997 return btrfs_rename_exchange(old_dir, old_dentry, new_dir,
9998 new_dentry);
9999
10000 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
10001 }
10002
10003 static void btrfs_run_delalloc_work(struct btrfs_work *work)
10004 {
10005 struct btrfs_delalloc_work *delalloc_work;
10006 struct inode *inode;
10007
10008 delalloc_work = container_of(work, struct btrfs_delalloc_work,
10009 work);
10010 inode = delalloc_work->inode;
10011 filemap_flush(inode->i_mapping);
10012 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
10013 &BTRFS_I(inode)->runtime_flags))
10014 filemap_flush(inode->i_mapping);
10015
10016 if (delalloc_work->delay_iput)
10017 btrfs_add_delayed_iput(inode);
10018 else
10019 iput(inode);
10020 complete(&delalloc_work->completion);
10021 }
10022
10023 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
10024 int delay_iput)
10025 {
10026 struct btrfs_delalloc_work *work;
10027
10028 work = kmalloc(sizeof(*work), GFP_NOFS);
10029 if (!work)
10030 return NULL;
10031
10032 init_completion(&work->completion);
10033 INIT_LIST_HEAD(&work->list);
10034 work->inode = inode;
10035 work->delay_iput = delay_iput;
10036 WARN_ON_ONCE(!inode);
10037 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
10038 btrfs_run_delalloc_work, NULL, NULL);
10039
10040 return work;
10041 }
10042
10043 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
10044 {
10045 wait_for_completion(&work->completion);
10046 kfree(work);
10047 }
10048
10049 /*
10050 * some fairly slow code that needs optimization. This walks the list
10051 * of all the inodes with pending delalloc and forces them to disk.
10052 */
10053 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
10054 int nr)
10055 {
10056 struct btrfs_inode *binode;
10057 struct inode *inode;
10058 struct btrfs_delalloc_work *work, *next;
10059 struct list_head works;
10060 struct list_head splice;
10061 int ret = 0;
10062
10063 INIT_LIST_HEAD(&works);
10064 INIT_LIST_HEAD(&splice);
10065
10066 mutex_lock(&root->delalloc_mutex);
10067 spin_lock(&root->delalloc_lock);
10068 list_splice_init(&root->delalloc_inodes, &splice);
10069 while (!list_empty(&splice)) {
10070 binode = list_entry(splice.next, struct btrfs_inode,
10071 delalloc_inodes);
10072
10073 list_move_tail(&binode->delalloc_inodes,
10074 &root->delalloc_inodes);
10075 inode = igrab(&binode->vfs_inode);
10076 if (!inode) {
10077 cond_resched_lock(&root->delalloc_lock);
10078 continue;
10079 }
10080 spin_unlock(&root->delalloc_lock);
10081
10082 work = btrfs_alloc_delalloc_work(inode, delay_iput);
10083 if (!work) {
10084 if (delay_iput)
10085 btrfs_add_delayed_iput(inode);
10086 else
10087 iput(inode);
10088 ret = -ENOMEM;
10089 goto out;
10090 }
10091 list_add_tail(&work->list, &works);
10092 btrfs_queue_work(root->fs_info->flush_workers,
10093 &work->work);
10094 ret++;
10095 if (nr != -1 && ret >= nr)
10096 goto out;
10097 cond_resched();
10098 spin_lock(&root->delalloc_lock);
10099 }
10100 spin_unlock(&root->delalloc_lock);
10101
10102 out:
10103 list_for_each_entry_safe(work, next, &works, list) {
10104 list_del_init(&work->list);
10105 btrfs_wait_and_free_delalloc_work(work);
10106 }
10107
10108 if (!list_empty_careful(&splice)) {
10109 spin_lock(&root->delalloc_lock);
10110 list_splice_tail(&splice, &root->delalloc_inodes);
10111 spin_unlock(&root->delalloc_lock);
10112 }
10113 mutex_unlock(&root->delalloc_mutex);
10114 return ret;
10115 }
10116
10117 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
10118 {
10119 int ret;
10120
10121 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
10122 return -EROFS;
10123
10124 ret = __start_delalloc_inodes(root, delay_iput, -1);
10125 if (ret > 0)
10126 ret = 0;
10127 /*
10128 * the filemap_flush will queue IO into the worker threads, but
10129 * we have to make sure the IO is actually started and that
10130 * ordered extents get created before we return
10131 */
10132 atomic_inc(&root->fs_info->async_submit_draining);
10133 while (atomic_read(&root->fs_info->nr_async_submits) ||
10134 atomic_read(&root->fs_info->async_delalloc_pages)) {
10135 wait_event(root->fs_info->async_submit_wait,
10136 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
10137 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
10138 }
10139 atomic_dec(&root->fs_info->async_submit_draining);
10140 return ret;
10141 }
10142
10143 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
10144 int nr)
10145 {
10146 struct btrfs_root *root;
10147 struct list_head splice;
10148 int ret;
10149
10150 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10151 return -EROFS;
10152
10153 INIT_LIST_HEAD(&splice);
10154
10155 mutex_lock(&fs_info->delalloc_root_mutex);
10156 spin_lock(&fs_info->delalloc_root_lock);
10157 list_splice_init(&fs_info->delalloc_roots, &splice);
10158 while (!list_empty(&splice) && nr) {
10159 root = list_first_entry(&splice, struct btrfs_root,
10160 delalloc_root);
10161 root = btrfs_grab_fs_root(root);
10162 BUG_ON(!root);
10163 list_move_tail(&root->delalloc_root,
10164 &fs_info->delalloc_roots);
10165 spin_unlock(&fs_info->delalloc_root_lock);
10166
10167 ret = __start_delalloc_inodes(root, delay_iput, nr);
10168 btrfs_put_fs_root(root);
10169 if (ret < 0)
10170 goto out;
10171
10172 if (nr != -1) {
10173 nr -= ret;
10174 WARN_ON(nr < 0);
10175 }
10176 spin_lock(&fs_info->delalloc_root_lock);
10177 }
10178 spin_unlock(&fs_info->delalloc_root_lock);
10179
10180 ret = 0;
10181 atomic_inc(&fs_info->async_submit_draining);
10182 while (atomic_read(&fs_info->nr_async_submits) ||
10183 atomic_read(&fs_info->async_delalloc_pages)) {
10184 wait_event(fs_info->async_submit_wait,
10185 (atomic_read(&fs_info->nr_async_submits) == 0 &&
10186 atomic_read(&fs_info->async_delalloc_pages) == 0));
10187 }
10188 atomic_dec(&fs_info->async_submit_draining);
10189 out:
10190 if (!list_empty_careful(&splice)) {
10191 spin_lock(&fs_info->delalloc_root_lock);
10192 list_splice_tail(&splice, &fs_info->delalloc_roots);
10193 spin_unlock(&fs_info->delalloc_root_lock);
10194 }
10195 mutex_unlock(&fs_info->delalloc_root_mutex);
10196 return ret;
10197 }
10198
10199 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
10200 const char *symname)
10201 {
10202 struct btrfs_trans_handle *trans;
10203 struct btrfs_root *root = BTRFS_I(dir)->root;
10204 struct btrfs_path *path;
10205 struct btrfs_key key;
10206 struct inode *inode = NULL;
10207 int err;
10208 int drop_inode = 0;
10209 u64 objectid;
10210 u64 index = 0;
10211 int name_len;
10212 int datasize;
10213 unsigned long ptr;
10214 struct btrfs_file_extent_item *ei;
10215 struct extent_buffer *leaf;
10216
10217 name_len = strlen(symname);
10218 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
10219 return -ENAMETOOLONG;
10220
10221 /*
10222 * 2 items for inode item and ref
10223 * 2 items for dir items
10224 * 1 item for updating parent inode item
10225 * 1 item for the inline extent item
10226 * 1 item for xattr if selinux is on
10227 */
10228 trans = btrfs_start_transaction(root, 7);
10229 if (IS_ERR(trans))
10230 return PTR_ERR(trans);
10231
10232 err = btrfs_find_free_ino(root, &objectid);
10233 if (err)
10234 goto out_unlock;
10235
10236 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
10237 dentry->d_name.len, btrfs_ino(dir), objectid,
10238 S_IFLNK|S_IRWXUGO, &index);
10239 if (IS_ERR(inode)) {
10240 err = PTR_ERR(inode);
10241 goto out_unlock;
10242 }
10243
10244 /*
10245 * If the active LSM wants to access the inode during
10246 * d_instantiate it needs these. Smack checks to see
10247 * if the filesystem supports xattrs by looking at the
10248 * ops vector.
10249 */
10250 inode->i_fop = &btrfs_file_operations;
10251 inode->i_op = &btrfs_file_inode_operations;
10252 inode->i_mapping->a_ops = &btrfs_aops;
10253 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10254
10255 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
10256 if (err)
10257 goto out_unlock_inode;
10258
10259 path = btrfs_alloc_path();
10260 if (!path) {
10261 err = -ENOMEM;
10262 goto out_unlock_inode;
10263 }
10264 key.objectid = btrfs_ino(inode);
10265 key.offset = 0;
10266 key.type = BTRFS_EXTENT_DATA_KEY;
10267 datasize = btrfs_file_extent_calc_inline_size(name_len);
10268 err = btrfs_insert_empty_item(trans, root, path, &key,
10269 datasize);
10270 if (err) {
10271 btrfs_free_path(path);
10272 goto out_unlock_inode;
10273 }
10274 leaf = path->nodes[0];
10275 ei = btrfs_item_ptr(leaf, path->slots[0],
10276 struct btrfs_file_extent_item);
10277 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
10278 btrfs_set_file_extent_type(leaf, ei,
10279 BTRFS_FILE_EXTENT_INLINE);
10280 btrfs_set_file_extent_encryption(leaf, ei, 0);
10281 btrfs_set_file_extent_compression(leaf, ei, 0);
10282 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
10283 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
10284
10285 ptr = btrfs_file_extent_inline_start(ei);
10286 write_extent_buffer(leaf, symname, ptr, name_len);
10287 btrfs_mark_buffer_dirty(leaf);
10288 btrfs_free_path(path);
10289
10290 inode->i_op = &btrfs_symlink_inode_operations;
10291 inode_nohighmem(inode);
10292 inode->i_mapping->a_ops = &btrfs_symlink_aops;
10293 inode_set_bytes(inode, name_len);
10294 btrfs_i_size_write(inode, name_len);
10295 err = btrfs_update_inode(trans, root, inode);
10296 /*
10297 * Last step, add directory indexes for our symlink inode. This is the
10298 * last step to avoid extra cleanup of these indexes if an error happens
10299 * elsewhere above.
10300 */
10301 if (!err)
10302 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
10303 if (err) {
10304 drop_inode = 1;
10305 goto out_unlock_inode;
10306 }
10307
10308 unlock_new_inode(inode);
10309 d_instantiate(dentry, inode);
10310
10311 out_unlock:
10312 btrfs_end_transaction(trans, root);
10313 if (drop_inode) {
10314 inode_dec_link_count(inode);
10315 iput(inode);
10316 }
10317 btrfs_btree_balance_dirty(root);
10318 return err;
10319
10320 out_unlock_inode:
10321 drop_inode = 1;
10322 unlock_new_inode(inode);
10323 goto out_unlock;
10324 }
10325
10326 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
10327 u64 start, u64 num_bytes, u64 min_size,
10328 loff_t actual_len, u64 *alloc_hint,
10329 struct btrfs_trans_handle *trans)
10330 {
10331 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
10332 struct extent_map *em;
10333 struct btrfs_root *root = BTRFS_I(inode)->root;
10334 struct btrfs_key ins;
10335 u64 cur_offset = start;
10336 u64 i_size;
10337 u64 cur_bytes;
10338 u64 last_alloc = (u64)-1;
10339 int ret = 0;
10340 bool own_trans = true;
10341 u64 end = start + num_bytes - 1;
10342
10343 if (trans)
10344 own_trans = false;
10345 while (num_bytes > 0) {
10346 if (own_trans) {
10347 trans = btrfs_start_transaction(root, 3);
10348 if (IS_ERR(trans)) {
10349 ret = PTR_ERR(trans);
10350 break;
10351 }
10352 }
10353
10354 cur_bytes = min_t(u64, num_bytes, SZ_256M);
10355 cur_bytes = max(cur_bytes, min_size);
10356 /*
10357 * If we are severely fragmented we could end up with really
10358 * small allocations, so if the allocator is returning small
10359 * chunks lets make its job easier by only searching for those
10360 * sized chunks.
10361 */
10362 cur_bytes = min(cur_bytes, last_alloc);
10363 ret = btrfs_reserve_extent(root, cur_bytes, cur_bytes,
10364 min_size, 0, *alloc_hint, &ins, 1, 0);
10365 if (ret) {
10366 if (own_trans)
10367 btrfs_end_transaction(trans, root);
10368 break;
10369 }
10370 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
10371
10372 last_alloc = ins.offset;
10373 ret = insert_reserved_file_extent(trans, inode,
10374 cur_offset, ins.objectid,
10375 ins.offset, ins.offset,
10376 ins.offset, 0, 0, 0,
10377 BTRFS_FILE_EXTENT_PREALLOC);
10378 if (ret) {
10379 btrfs_free_reserved_extent(root, ins.objectid,
10380 ins.offset, 0);
10381 btrfs_abort_transaction(trans, ret);
10382 if (own_trans)
10383 btrfs_end_transaction(trans, root);
10384 break;
10385 }
10386
10387 btrfs_drop_extent_cache(inode, cur_offset,
10388 cur_offset + ins.offset -1, 0);
10389
10390 em = alloc_extent_map();
10391 if (!em) {
10392 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
10393 &BTRFS_I(inode)->runtime_flags);
10394 goto next;
10395 }
10396
10397 em->start = cur_offset;
10398 em->orig_start = cur_offset;
10399 em->len = ins.offset;
10400 em->block_start = ins.objectid;
10401 em->block_len = ins.offset;
10402 em->orig_block_len = ins.offset;
10403 em->ram_bytes = ins.offset;
10404 em->bdev = root->fs_info->fs_devices->latest_bdev;
10405 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
10406 em->generation = trans->transid;
10407
10408 while (1) {
10409 write_lock(&em_tree->lock);
10410 ret = add_extent_mapping(em_tree, em, 1);
10411 write_unlock(&em_tree->lock);
10412 if (ret != -EEXIST)
10413 break;
10414 btrfs_drop_extent_cache(inode, cur_offset,
10415 cur_offset + ins.offset - 1,
10416 0);
10417 }
10418 free_extent_map(em);
10419 next:
10420 num_bytes -= ins.offset;
10421 cur_offset += ins.offset;
10422 *alloc_hint = ins.objectid + ins.offset;
10423
10424 inode_inc_iversion(inode);
10425 inode->i_ctime = current_time(inode);
10426 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
10427 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
10428 (actual_len > inode->i_size) &&
10429 (cur_offset > inode->i_size)) {
10430 if (cur_offset > actual_len)
10431 i_size = actual_len;
10432 else
10433 i_size = cur_offset;
10434 i_size_write(inode, i_size);
10435 btrfs_ordered_update_i_size(inode, i_size, NULL);
10436 }
10437
10438 ret = btrfs_update_inode(trans, root, inode);
10439
10440 if (ret) {
10441 btrfs_abort_transaction(trans, ret);
10442 if (own_trans)
10443 btrfs_end_transaction(trans, root);
10444 break;
10445 }
10446
10447 if (own_trans)
10448 btrfs_end_transaction(trans, root);
10449 }
10450 if (cur_offset < end)
10451 btrfs_free_reserved_data_space(inode, cur_offset,
10452 end - cur_offset + 1);
10453 return ret;
10454 }
10455
10456 int btrfs_prealloc_file_range(struct inode *inode, int mode,
10457 u64 start, u64 num_bytes, u64 min_size,
10458 loff_t actual_len, u64 *alloc_hint)
10459 {
10460 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10461 min_size, actual_len, alloc_hint,
10462 NULL);
10463 }
10464
10465 int btrfs_prealloc_file_range_trans(struct inode *inode,
10466 struct btrfs_trans_handle *trans, int mode,
10467 u64 start, u64 num_bytes, u64 min_size,
10468 loff_t actual_len, u64 *alloc_hint)
10469 {
10470 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10471 min_size, actual_len, alloc_hint, trans);
10472 }
10473
10474 static int btrfs_set_page_dirty(struct page *page)
10475 {
10476 return __set_page_dirty_nobuffers(page);
10477 }
10478
10479 static int btrfs_permission(struct inode *inode, int mask)
10480 {
10481 struct btrfs_root *root = BTRFS_I(inode)->root;
10482 umode_t mode = inode->i_mode;
10483
10484 if (mask & MAY_WRITE &&
10485 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
10486 if (btrfs_root_readonly(root))
10487 return -EROFS;
10488 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
10489 return -EACCES;
10490 }
10491 return generic_permission(inode, mask);
10492 }
10493
10494 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
10495 {
10496 struct btrfs_trans_handle *trans;
10497 struct btrfs_root *root = BTRFS_I(dir)->root;
10498 struct inode *inode = NULL;
10499 u64 objectid;
10500 u64 index;
10501 int ret = 0;
10502
10503 /*
10504 * 5 units required for adding orphan entry
10505 */
10506 trans = btrfs_start_transaction(root, 5);
10507 if (IS_ERR(trans))
10508 return PTR_ERR(trans);
10509
10510 ret = btrfs_find_free_ino(root, &objectid);
10511 if (ret)
10512 goto out;
10513
10514 inode = btrfs_new_inode(trans, root, dir, NULL, 0,
10515 btrfs_ino(dir), objectid, mode, &index);
10516 if (IS_ERR(inode)) {
10517 ret = PTR_ERR(inode);
10518 inode = NULL;
10519 goto out;
10520 }
10521
10522 inode->i_fop = &btrfs_file_operations;
10523 inode->i_op = &btrfs_file_inode_operations;
10524
10525 inode->i_mapping->a_ops = &btrfs_aops;
10526 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10527
10528 ret = btrfs_init_inode_security(trans, inode, dir, NULL);
10529 if (ret)
10530 goto out_inode;
10531
10532 ret = btrfs_update_inode(trans, root, inode);
10533 if (ret)
10534 goto out_inode;
10535 ret = btrfs_orphan_add(trans, inode);
10536 if (ret)
10537 goto out_inode;
10538
10539 /*
10540 * We set number of links to 0 in btrfs_new_inode(), and here we set
10541 * it to 1 because d_tmpfile() will issue a warning if the count is 0,
10542 * through:
10543 *
10544 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
10545 */
10546 set_nlink(inode, 1);
10547 unlock_new_inode(inode);
10548 d_tmpfile(dentry, inode);
10549 mark_inode_dirty(inode);
10550
10551 out:
10552 btrfs_end_transaction(trans, root);
10553 if (ret)
10554 iput(inode);
10555 btrfs_balance_delayed_items(root);
10556 btrfs_btree_balance_dirty(root);
10557 return ret;
10558
10559 out_inode:
10560 unlock_new_inode(inode);
10561 goto out;
10562
10563 }
10564
10565 static const struct inode_operations btrfs_dir_inode_operations = {
10566 .getattr = btrfs_getattr,
10567 .lookup = btrfs_lookup,
10568 .create = btrfs_create,
10569 .unlink = btrfs_unlink,
10570 .link = btrfs_link,
10571 .mkdir = btrfs_mkdir,
10572 .rmdir = btrfs_rmdir,
10573 .rename = btrfs_rename2,
10574 .symlink = btrfs_symlink,
10575 .setattr = btrfs_setattr,
10576 .mknod = btrfs_mknod,
10577 .listxattr = btrfs_listxattr,
10578 .permission = btrfs_permission,
10579 .get_acl = btrfs_get_acl,
10580 .set_acl = btrfs_set_acl,
10581 .update_time = btrfs_update_time,
10582 .tmpfile = btrfs_tmpfile,
10583 };
10584 static const struct inode_operations btrfs_dir_ro_inode_operations = {
10585 .lookup = btrfs_lookup,
10586 .permission = btrfs_permission,
10587 .get_acl = btrfs_get_acl,
10588 .set_acl = btrfs_set_acl,
10589 .update_time = btrfs_update_time,
10590 };
10591
10592 static const struct file_operations btrfs_dir_file_operations = {
10593 .llseek = generic_file_llseek,
10594 .read = generic_read_dir,
10595 .iterate_shared = btrfs_real_readdir,
10596 .unlocked_ioctl = btrfs_ioctl,
10597 #ifdef CONFIG_COMPAT
10598 .compat_ioctl = btrfs_compat_ioctl,
10599 #endif
10600 .release = btrfs_release_file,
10601 .fsync = btrfs_sync_file,
10602 };
10603
10604 static const struct extent_io_ops btrfs_extent_io_ops = {
10605 .fill_delalloc = run_delalloc_range,
10606 .submit_bio_hook = btrfs_submit_bio_hook,
10607 .merge_bio_hook = btrfs_merge_bio_hook,
10608 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
10609 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
10610 .writepage_start_hook = btrfs_writepage_start_hook,
10611 .set_bit_hook = btrfs_set_bit_hook,
10612 .clear_bit_hook = btrfs_clear_bit_hook,
10613 .merge_extent_hook = btrfs_merge_extent_hook,
10614 .split_extent_hook = btrfs_split_extent_hook,
10615 };
10616
10617 /*
10618 * btrfs doesn't support the bmap operation because swapfiles
10619 * use bmap to make a mapping of extents in the file. They assume
10620 * these extents won't change over the life of the file and they
10621 * use the bmap result to do IO directly to the drive.
10622 *
10623 * the btrfs bmap call would return logical addresses that aren't
10624 * suitable for IO and they also will change frequently as COW
10625 * operations happen. So, swapfile + btrfs == corruption.
10626 *
10627 * For now we're avoiding this by dropping bmap.
10628 */
10629 static const struct address_space_operations btrfs_aops = {
10630 .readpage = btrfs_readpage,
10631 .writepage = btrfs_writepage,
10632 .writepages = btrfs_writepages,
10633 .readpages = btrfs_readpages,
10634 .direct_IO = btrfs_direct_IO,
10635 .invalidatepage = btrfs_invalidatepage,
10636 .releasepage = btrfs_releasepage,
10637 .set_page_dirty = btrfs_set_page_dirty,
10638 .error_remove_page = generic_error_remove_page,
10639 };
10640
10641 static const struct address_space_operations btrfs_symlink_aops = {
10642 .readpage = btrfs_readpage,
10643 .writepage = btrfs_writepage,
10644 .invalidatepage = btrfs_invalidatepage,
10645 .releasepage = btrfs_releasepage,
10646 };
10647
10648 static const struct inode_operations btrfs_file_inode_operations = {
10649 .getattr = btrfs_getattr,
10650 .setattr = btrfs_setattr,
10651 .listxattr = btrfs_listxattr,
10652 .permission = btrfs_permission,
10653 .fiemap = btrfs_fiemap,
10654 .get_acl = btrfs_get_acl,
10655 .set_acl = btrfs_set_acl,
10656 .update_time = btrfs_update_time,
10657 };
10658 static const struct inode_operations btrfs_special_inode_operations = {
10659 .getattr = btrfs_getattr,
10660 .setattr = btrfs_setattr,
10661 .permission = btrfs_permission,
10662 .listxattr = btrfs_listxattr,
10663 .get_acl = btrfs_get_acl,
10664 .set_acl = btrfs_set_acl,
10665 .update_time = btrfs_update_time,
10666 };
10667 static const struct inode_operations btrfs_symlink_inode_operations = {
10668 .readlink = generic_readlink,
10669 .get_link = page_get_link,
10670 .getattr = btrfs_getattr,
10671 .setattr = btrfs_setattr,
10672 .permission = btrfs_permission,
10673 .listxattr = btrfs_listxattr,
10674 .update_time = btrfs_update_time,
10675 };
10676
10677 const struct dentry_operations btrfs_dentry_operations = {
10678 .d_delete = btrfs_dentry_delete,
10679 .d_release = btrfs_dentry_release,
10680 };
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