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Merge branch 'for-linus-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/mason...
[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
64 struct btrfs_iget_args {
65 struct btrfs_key *location;
66 struct btrfs_root *root;
67 };
68
69 struct btrfs_dio_data {
70 u64 outstanding_extents;
71 u64 reserve;
72 u64 unsubmitted_oe_range_start;
73 u64 unsubmitted_oe_range_end;
74 };
75
76 static const struct inode_operations btrfs_dir_inode_operations;
77 static const struct inode_operations btrfs_symlink_inode_operations;
78 static const struct inode_operations btrfs_dir_ro_inode_operations;
79 static const struct inode_operations btrfs_special_inode_operations;
80 static const struct inode_operations btrfs_file_inode_operations;
81 static const struct address_space_operations btrfs_aops;
82 static const struct address_space_operations btrfs_symlink_aops;
83 static const struct file_operations btrfs_dir_file_operations;
84 static const struct extent_io_ops btrfs_extent_io_ops;
85
86 static struct kmem_cache *btrfs_inode_cachep;
87 struct kmem_cache *btrfs_trans_handle_cachep;
88 struct kmem_cache *btrfs_transaction_cachep;
89 struct kmem_cache *btrfs_path_cachep;
90 struct kmem_cache *btrfs_free_space_cachep;
91
92 #define S_SHIFT 12
93 static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
94 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
95 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
96 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
97 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
98 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
99 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
100 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
101 };
102
103 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
104 static int btrfs_truncate(struct inode *inode);
105 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
106 static noinline int cow_file_range(struct inode *inode,
107 struct page *locked_page,
108 u64 start, u64 end, int *page_started,
109 unsigned long *nr_written, int unlock);
110 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
111 u64 len, u64 orig_start,
112 u64 block_start, u64 block_len,
113 u64 orig_block_len, u64 ram_bytes,
114 int type);
115
116 static int btrfs_dirty_inode(struct inode *inode);
117
118 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
119 void btrfs_test_inode_set_ops(struct inode *inode)
120 {
121 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
122 }
123 #endif
124
125 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
126 struct inode *inode, struct inode *dir,
127 const struct qstr *qstr)
128 {
129 int err;
130
131 err = btrfs_init_acl(trans, inode, dir);
132 if (!err)
133 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
134 return err;
135 }
136
137 /*
138 * this does all the hard work for inserting an inline extent into
139 * the btree. The caller should have done a btrfs_drop_extents so that
140 * no overlapping inline items exist in the btree
141 */
142 static int insert_inline_extent(struct btrfs_trans_handle *trans,
143 struct btrfs_path *path, int extent_inserted,
144 struct btrfs_root *root, struct inode *inode,
145 u64 start, size_t size, size_t compressed_size,
146 int compress_type,
147 struct page **compressed_pages)
148 {
149 struct extent_buffer *leaf;
150 struct page *page = NULL;
151 char *kaddr;
152 unsigned long ptr;
153 struct btrfs_file_extent_item *ei;
154 int err = 0;
155 int ret;
156 size_t cur_size = size;
157 unsigned long offset;
158
159 if (compressed_size && compressed_pages)
160 cur_size = compressed_size;
161
162 inode_add_bytes(inode, size);
163
164 if (!extent_inserted) {
165 struct btrfs_key key;
166 size_t datasize;
167
168 key.objectid = btrfs_ino(inode);
169 key.offset = start;
170 key.type = BTRFS_EXTENT_DATA_KEY;
171
172 datasize = btrfs_file_extent_calc_inline_size(cur_size);
173 path->leave_spinning = 1;
174 ret = btrfs_insert_empty_item(trans, root, path, &key,
175 datasize);
176 if (ret) {
177 err = ret;
178 goto fail;
179 }
180 }
181 leaf = path->nodes[0];
182 ei = btrfs_item_ptr(leaf, path->slots[0],
183 struct btrfs_file_extent_item);
184 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
185 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
186 btrfs_set_file_extent_encryption(leaf, ei, 0);
187 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
188 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
189 ptr = btrfs_file_extent_inline_start(ei);
190
191 if (compress_type != BTRFS_COMPRESS_NONE) {
192 struct page *cpage;
193 int i = 0;
194 while (compressed_size > 0) {
195 cpage = compressed_pages[i];
196 cur_size = min_t(unsigned long, compressed_size,
197 PAGE_SIZE);
198
199 kaddr = kmap_atomic(cpage);
200 write_extent_buffer(leaf, kaddr, ptr, cur_size);
201 kunmap_atomic(kaddr);
202
203 i++;
204 ptr += cur_size;
205 compressed_size -= cur_size;
206 }
207 btrfs_set_file_extent_compression(leaf, ei,
208 compress_type);
209 } else {
210 page = find_get_page(inode->i_mapping,
211 start >> PAGE_SHIFT);
212 btrfs_set_file_extent_compression(leaf, ei, 0);
213 kaddr = kmap_atomic(page);
214 offset = start & (PAGE_SIZE - 1);
215 write_extent_buffer(leaf, kaddr + offset, ptr, size);
216 kunmap_atomic(kaddr);
217 put_page(page);
218 }
219 btrfs_mark_buffer_dirty(leaf);
220 btrfs_release_path(path);
221
222 /*
223 * we're an inline extent, so nobody can
224 * extend the file past i_size without locking
225 * a page we already have locked.
226 *
227 * We must do any isize and inode updates
228 * before we unlock the pages. Otherwise we
229 * could end up racing with unlink.
230 */
231 BTRFS_I(inode)->disk_i_size = inode->i_size;
232 ret = btrfs_update_inode(trans, root, inode);
233
234 return ret;
235 fail:
236 return err;
237 }
238
239
240 /*
241 * conditionally insert an inline extent into the file. This
242 * does the checks required to make sure the data is small enough
243 * to fit as an inline extent.
244 */
245 static noinline int cow_file_range_inline(struct btrfs_root *root,
246 struct inode *inode, u64 start,
247 u64 end, size_t compressed_size,
248 int compress_type,
249 struct page **compressed_pages)
250 {
251 struct btrfs_trans_handle *trans;
252 u64 isize = i_size_read(inode);
253 u64 actual_end = min(end + 1, isize);
254 u64 inline_len = actual_end - start;
255 u64 aligned_end = ALIGN(end, root->sectorsize);
256 u64 data_len = inline_len;
257 int ret;
258 struct btrfs_path *path;
259 int extent_inserted = 0;
260 u32 extent_item_size;
261
262 if (compressed_size)
263 data_len = compressed_size;
264
265 if (start > 0 ||
266 actual_end > root->sectorsize ||
267 data_len > BTRFS_MAX_INLINE_DATA_SIZE(root) ||
268 (!compressed_size &&
269 (actual_end & (root->sectorsize - 1)) == 0) ||
270 end + 1 < isize ||
271 data_len > root->fs_info->max_inline) {
272 return 1;
273 }
274
275 path = btrfs_alloc_path();
276 if (!path)
277 return -ENOMEM;
278
279 trans = btrfs_join_transaction(root);
280 if (IS_ERR(trans)) {
281 btrfs_free_path(path);
282 return PTR_ERR(trans);
283 }
284 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
285
286 if (compressed_size && compressed_pages)
287 extent_item_size = btrfs_file_extent_calc_inline_size(
288 compressed_size);
289 else
290 extent_item_size = btrfs_file_extent_calc_inline_size(
291 inline_len);
292
293 ret = __btrfs_drop_extents(trans, root, inode, path,
294 start, aligned_end, NULL,
295 1, 1, extent_item_size, &extent_inserted);
296 if (ret) {
297 btrfs_abort_transaction(trans, root, ret);
298 goto out;
299 }
300
301 if (isize > actual_end)
302 inline_len = min_t(u64, isize, actual_end);
303 ret = insert_inline_extent(trans, path, extent_inserted,
304 root, inode, start,
305 inline_len, compressed_size,
306 compress_type, compressed_pages);
307 if (ret && ret != -ENOSPC) {
308 btrfs_abort_transaction(trans, root, ret);
309 goto out;
310 } else if (ret == -ENOSPC) {
311 ret = 1;
312 goto out;
313 }
314
315 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
316 btrfs_delalloc_release_metadata(inode, end + 1 - start);
317 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
318 out:
319 /*
320 * Don't forget to free the reserved space, as for inlined extent
321 * it won't count as data extent, free them directly here.
322 * And at reserve time, it's always aligned to page size, so
323 * just free one page here.
324 */
325 btrfs_qgroup_free_data(inode, 0, PAGE_SIZE);
326 btrfs_free_path(path);
327 btrfs_end_transaction(trans, root);
328 return ret;
329 }
330
331 struct async_extent {
332 u64 start;
333 u64 ram_size;
334 u64 compressed_size;
335 struct page **pages;
336 unsigned long nr_pages;
337 int compress_type;
338 struct list_head list;
339 };
340
341 struct async_cow {
342 struct inode *inode;
343 struct btrfs_root *root;
344 struct page *locked_page;
345 u64 start;
346 u64 end;
347 struct list_head extents;
348 struct btrfs_work work;
349 };
350
351 static noinline int add_async_extent(struct async_cow *cow,
352 u64 start, u64 ram_size,
353 u64 compressed_size,
354 struct page **pages,
355 unsigned long nr_pages,
356 int compress_type)
357 {
358 struct async_extent *async_extent;
359
360 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
361 BUG_ON(!async_extent); /* -ENOMEM */
362 async_extent->start = start;
363 async_extent->ram_size = ram_size;
364 async_extent->compressed_size = compressed_size;
365 async_extent->pages = pages;
366 async_extent->nr_pages = nr_pages;
367 async_extent->compress_type = compress_type;
368 list_add_tail(&async_extent->list, &cow->extents);
369 return 0;
370 }
371
372 static inline int inode_need_compress(struct inode *inode)
373 {
374 struct btrfs_root *root = BTRFS_I(inode)->root;
375
376 /* force compress */
377 if (btrfs_test_opt(root, FORCE_COMPRESS))
378 return 1;
379 /* bad compression ratios */
380 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
381 return 0;
382 if (btrfs_test_opt(root, COMPRESS) ||
383 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
384 BTRFS_I(inode)->force_compress)
385 return 1;
386 return 0;
387 }
388
389 /*
390 * we create compressed extents in two phases. The first
391 * phase compresses a range of pages that have already been
392 * locked (both pages and state bits are locked).
393 *
394 * This is done inside an ordered work queue, and the compression
395 * is spread across many cpus. The actual IO submission is step
396 * two, and the ordered work queue takes care of making sure that
397 * happens in the same order things were put onto the queue by
398 * writepages and friends.
399 *
400 * If this code finds it can't get good compression, it puts an
401 * entry onto the work queue to write the uncompressed bytes. This
402 * makes sure that both compressed inodes and uncompressed inodes
403 * are written in the same order that the flusher thread sent them
404 * down.
405 */
406 static noinline void compress_file_range(struct inode *inode,
407 struct page *locked_page,
408 u64 start, u64 end,
409 struct async_cow *async_cow,
410 int *num_added)
411 {
412 struct btrfs_root *root = BTRFS_I(inode)->root;
413 u64 num_bytes;
414 u64 blocksize = root->sectorsize;
415 u64 actual_end;
416 u64 isize = i_size_read(inode);
417 int ret = 0;
418 struct page **pages = NULL;
419 unsigned long nr_pages;
420 unsigned long nr_pages_ret = 0;
421 unsigned long total_compressed = 0;
422 unsigned long total_in = 0;
423 unsigned long max_compressed = SZ_128K;
424 unsigned long max_uncompressed = SZ_128K;
425 int i;
426 int will_compress;
427 int compress_type = root->fs_info->compress_type;
428 int redirty = 0;
429
430 /* if this is a small write inside eof, kick off a defrag */
431 if ((end - start + 1) < SZ_16K &&
432 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
433 btrfs_add_inode_defrag(NULL, inode);
434
435 actual_end = min_t(u64, isize, end + 1);
436 again:
437 will_compress = 0;
438 nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
439 nr_pages = min_t(unsigned long, nr_pages, SZ_128K / PAGE_SIZE);
440
441 /*
442 * we don't want to send crud past the end of i_size through
443 * compression, that's just a waste of CPU time. So, if the
444 * end of the file is before the start of our current
445 * requested range of bytes, we bail out to the uncompressed
446 * cleanup code that can deal with all of this.
447 *
448 * It isn't really the fastest way to fix things, but this is a
449 * very uncommon corner.
450 */
451 if (actual_end <= start)
452 goto cleanup_and_bail_uncompressed;
453
454 total_compressed = actual_end - start;
455
456 /*
457 * skip compression for a small file range(<=blocksize) that
458 * isn't an inline extent, since it doesn't save disk space at all.
459 */
460 if (total_compressed <= blocksize &&
461 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
462 goto cleanup_and_bail_uncompressed;
463
464 /* we want to make sure that amount of ram required to uncompress
465 * an extent is reasonable, so we limit the total size in ram
466 * of a compressed extent to 128k. This is a crucial number
467 * because it also controls how easily we can spread reads across
468 * cpus for decompression.
469 *
470 * We also want to make sure the amount of IO required to do
471 * a random read is reasonably small, so we limit the size of
472 * a compressed extent to 128k.
473 */
474 total_compressed = min(total_compressed, max_uncompressed);
475 num_bytes = ALIGN(end - start + 1, blocksize);
476 num_bytes = max(blocksize, num_bytes);
477 total_in = 0;
478 ret = 0;
479
480 /*
481 * we do compression for mount -o compress and when the
482 * inode has not been flagged as nocompress. This flag can
483 * change at any time if we discover bad compression ratios.
484 */
485 if (inode_need_compress(inode)) {
486 WARN_ON(pages);
487 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
488 if (!pages) {
489 /* just bail out to the uncompressed code */
490 goto cont;
491 }
492
493 if (BTRFS_I(inode)->force_compress)
494 compress_type = BTRFS_I(inode)->force_compress;
495
496 /*
497 * we need to call clear_page_dirty_for_io on each
498 * page in the range. Otherwise applications with the file
499 * mmap'd can wander in and change the page contents while
500 * we are compressing them.
501 *
502 * If the compression fails for any reason, we set the pages
503 * dirty again later on.
504 */
505 extent_range_clear_dirty_for_io(inode, start, end);
506 redirty = 1;
507 ret = btrfs_compress_pages(compress_type,
508 inode->i_mapping, start,
509 total_compressed, pages,
510 nr_pages, &nr_pages_ret,
511 &total_in,
512 &total_compressed,
513 max_compressed);
514
515 if (!ret) {
516 unsigned long offset = total_compressed &
517 (PAGE_SIZE - 1);
518 struct page *page = pages[nr_pages_ret - 1];
519 char *kaddr;
520
521 /* zero the tail end of the last page, we might be
522 * sending it down to disk
523 */
524 if (offset) {
525 kaddr = kmap_atomic(page);
526 memset(kaddr + offset, 0,
527 PAGE_SIZE - offset);
528 kunmap_atomic(kaddr);
529 }
530 will_compress = 1;
531 }
532 }
533 cont:
534 if (start == 0) {
535 /* lets try to make an inline extent */
536 if (ret || total_in < (actual_end - start)) {
537 /* we didn't compress the entire range, try
538 * to make an uncompressed inline extent.
539 */
540 ret = cow_file_range_inline(root, inode, start, end,
541 0, 0, NULL);
542 } else {
543 /* try making a compressed inline extent */
544 ret = cow_file_range_inline(root, inode, start, end,
545 total_compressed,
546 compress_type, pages);
547 }
548 if (ret <= 0) {
549 unsigned long clear_flags = EXTENT_DELALLOC |
550 EXTENT_DEFRAG;
551 unsigned long page_error_op;
552
553 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0;
554 page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
555
556 /*
557 * inline extent creation worked or returned error,
558 * we don't need to create any more async work items.
559 * Unlock and free up our temp pages.
560 */
561 extent_clear_unlock_delalloc(inode, start, end, NULL,
562 clear_flags, PAGE_UNLOCK |
563 PAGE_CLEAR_DIRTY |
564 PAGE_SET_WRITEBACK |
565 page_error_op |
566 PAGE_END_WRITEBACK);
567 goto free_pages_out;
568 }
569 }
570
571 if (will_compress) {
572 /*
573 * we aren't doing an inline extent round the compressed size
574 * up to a block size boundary so the allocator does sane
575 * things
576 */
577 total_compressed = ALIGN(total_compressed, blocksize);
578
579 /*
580 * one last check to make sure the compression is really a
581 * win, compare the page count read with the blocks on disk
582 */
583 total_in = ALIGN(total_in, PAGE_SIZE);
584 if (total_compressed >= total_in) {
585 will_compress = 0;
586 } else {
587 num_bytes = total_in;
588 }
589 }
590 if (!will_compress && pages) {
591 /*
592 * the compression code ran but failed to make things smaller,
593 * free any pages it allocated and our page pointer array
594 */
595 for (i = 0; i < nr_pages_ret; i++) {
596 WARN_ON(pages[i]->mapping);
597 put_page(pages[i]);
598 }
599 kfree(pages);
600 pages = NULL;
601 total_compressed = 0;
602 nr_pages_ret = 0;
603
604 /* flag the file so we don't compress in the future */
605 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
606 !(BTRFS_I(inode)->force_compress)) {
607 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
608 }
609 }
610 if (will_compress) {
611 *num_added += 1;
612
613 /* the async work queues will take care of doing actual
614 * allocation on disk for these compressed pages,
615 * and will submit them to the elevator.
616 */
617 add_async_extent(async_cow, start, num_bytes,
618 total_compressed, pages, nr_pages_ret,
619 compress_type);
620
621 if (start + num_bytes < end) {
622 start += num_bytes;
623 pages = NULL;
624 cond_resched();
625 goto again;
626 }
627 } else {
628 cleanup_and_bail_uncompressed:
629 /*
630 * No compression, but we still need to write the pages in
631 * the file we've been given so far. redirty the locked
632 * page if it corresponds to our extent and set things up
633 * for the async work queue to run cow_file_range to do
634 * the normal delalloc dance
635 */
636 if (page_offset(locked_page) >= start &&
637 page_offset(locked_page) <= end) {
638 __set_page_dirty_nobuffers(locked_page);
639 /* unlocked later on in the async handlers */
640 }
641 if (redirty)
642 extent_range_redirty_for_io(inode, start, end);
643 add_async_extent(async_cow, start, end - start + 1,
644 0, NULL, 0, BTRFS_COMPRESS_NONE);
645 *num_added += 1;
646 }
647
648 return;
649
650 free_pages_out:
651 for (i = 0; i < nr_pages_ret; i++) {
652 WARN_ON(pages[i]->mapping);
653 put_page(pages[i]);
654 }
655 kfree(pages);
656 }
657
658 static void free_async_extent_pages(struct async_extent *async_extent)
659 {
660 int i;
661
662 if (!async_extent->pages)
663 return;
664
665 for (i = 0; i < async_extent->nr_pages; i++) {
666 WARN_ON(async_extent->pages[i]->mapping);
667 put_page(async_extent->pages[i]);
668 }
669 kfree(async_extent->pages);
670 async_extent->nr_pages = 0;
671 async_extent->pages = NULL;
672 }
673
674 /*
675 * phase two of compressed writeback. This is the ordered portion
676 * of the code, which only gets called in the order the work was
677 * queued. We walk all the async extents created by compress_file_range
678 * and send them down to the disk.
679 */
680 static noinline void submit_compressed_extents(struct inode *inode,
681 struct async_cow *async_cow)
682 {
683 struct async_extent *async_extent;
684 u64 alloc_hint = 0;
685 struct btrfs_key ins;
686 struct extent_map *em;
687 struct btrfs_root *root = BTRFS_I(inode)->root;
688 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
689 struct extent_io_tree *io_tree;
690 int ret = 0;
691
692 again:
693 while (!list_empty(&async_cow->extents)) {
694 async_extent = list_entry(async_cow->extents.next,
695 struct async_extent, list);
696 list_del(&async_extent->list);
697
698 io_tree = &BTRFS_I(inode)->io_tree;
699
700 retry:
701 /* did the compression code fall back to uncompressed IO? */
702 if (!async_extent->pages) {
703 int page_started = 0;
704 unsigned long nr_written = 0;
705
706 lock_extent(io_tree, async_extent->start,
707 async_extent->start +
708 async_extent->ram_size - 1);
709
710 /* allocate blocks */
711 ret = cow_file_range(inode, async_cow->locked_page,
712 async_extent->start,
713 async_extent->start +
714 async_extent->ram_size - 1,
715 &page_started, &nr_written, 0);
716
717 /* JDM XXX */
718
719 /*
720 * if page_started, cow_file_range inserted an
721 * inline extent and took care of all the unlocking
722 * and IO for us. Otherwise, we need to submit
723 * all those pages down to the drive.
724 */
725 if (!page_started && !ret)
726 extent_write_locked_range(io_tree,
727 inode, async_extent->start,
728 async_extent->start +
729 async_extent->ram_size - 1,
730 btrfs_get_extent,
731 WB_SYNC_ALL);
732 else if (ret)
733 unlock_page(async_cow->locked_page);
734 kfree(async_extent);
735 cond_resched();
736 continue;
737 }
738
739 lock_extent(io_tree, async_extent->start,
740 async_extent->start + async_extent->ram_size - 1);
741
742 ret = btrfs_reserve_extent(root,
743 async_extent->compressed_size,
744 async_extent->compressed_size,
745 0, alloc_hint, &ins, 1, 1);
746 if (ret) {
747 free_async_extent_pages(async_extent);
748
749 if (ret == -ENOSPC) {
750 unlock_extent(io_tree, async_extent->start,
751 async_extent->start +
752 async_extent->ram_size - 1);
753
754 /*
755 * we need to redirty the pages if we decide to
756 * fallback to uncompressed IO, otherwise we
757 * will not submit these pages down to lower
758 * layers.
759 */
760 extent_range_redirty_for_io(inode,
761 async_extent->start,
762 async_extent->start +
763 async_extent->ram_size - 1);
764
765 goto retry;
766 }
767 goto out_free;
768 }
769 /*
770 * here we're doing allocation and writeback of the
771 * compressed pages
772 */
773 btrfs_drop_extent_cache(inode, async_extent->start,
774 async_extent->start +
775 async_extent->ram_size - 1, 0);
776
777 em = alloc_extent_map();
778 if (!em) {
779 ret = -ENOMEM;
780 goto out_free_reserve;
781 }
782 em->start = async_extent->start;
783 em->len = async_extent->ram_size;
784 em->orig_start = em->start;
785 em->mod_start = em->start;
786 em->mod_len = em->len;
787
788 em->block_start = ins.objectid;
789 em->block_len = ins.offset;
790 em->orig_block_len = ins.offset;
791 em->ram_bytes = async_extent->ram_size;
792 em->bdev = root->fs_info->fs_devices->latest_bdev;
793 em->compress_type = async_extent->compress_type;
794 set_bit(EXTENT_FLAG_PINNED, &em->flags);
795 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
796 em->generation = -1;
797
798 while (1) {
799 write_lock(&em_tree->lock);
800 ret = add_extent_mapping(em_tree, em, 1);
801 write_unlock(&em_tree->lock);
802 if (ret != -EEXIST) {
803 free_extent_map(em);
804 break;
805 }
806 btrfs_drop_extent_cache(inode, async_extent->start,
807 async_extent->start +
808 async_extent->ram_size - 1, 0);
809 }
810
811 if (ret)
812 goto out_free_reserve;
813
814 ret = btrfs_add_ordered_extent_compress(inode,
815 async_extent->start,
816 ins.objectid,
817 async_extent->ram_size,
818 ins.offset,
819 BTRFS_ORDERED_COMPRESSED,
820 async_extent->compress_type);
821 if (ret) {
822 btrfs_drop_extent_cache(inode, async_extent->start,
823 async_extent->start +
824 async_extent->ram_size - 1, 0);
825 goto out_free_reserve;
826 }
827 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
828
829 /*
830 * clear dirty, set writeback and unlock the pages.
831 */
832 extent_clear_unlock_delalloc(inode, async_extent->start,
833 async_extent->start +
834 async_extent->ram_size - 1,
835 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
836 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
837 PAGE_SET_WRITEBACK);
838 ret = btrfs_submit_compressed_write(inode,
839 async_extent->start,
840 async_extent->ram_size,
841 ins.objectid,
842 ins.offset, async_extent->pages,
843 async_extent->nr_pages);
844 if (ret) {
845 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
846 struct page *p = async_extent->pages[0];
847 const u64 start = async_extent->start;
848 const u64 end = start + async_extent->ram_size - 1;
849
850 p->mapping = inode->i_mapping;
851 tree->ops->writepage_end_io_hook(p, start, end,
852 NULL, 0);
853 p->mapping = NULL;
854 extent_clear_unlock_delalloc(inode, start, end, NULL, 0,
855 PAGE_END_WRITEBACK |
856 PAGE_SET_ERROR);
857 free_async_extent_pages(async_extent);
858 }
859 alloc_hint = ins.objectid + ins.offset;
860 kfree(async_extent);
861 cond_resched();
862 }
863 return;
864 out_free_reserve:
865 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
866 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
867 out_free:
868 extent_clear_unlock_delalloc(inode, async_extent->start,
869 async_extent->start +
870 async_extent->ram_size - 1,
871 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
872 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
873 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
874 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
875 PAGE_SET_ERROR);
876 free_async_extent_pages(async_extent);
877 kfree(async_extent);
878 goto again;
879 }
880
881 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
882 u64 num_bytes)
883 {
884 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
885 struct extent_map *em;
886 u64 alloc_hint = 0;
887
888 read_lock(&em_tree->lock);
889 em = search_extent_mapping(em_tree, start, num_bytes);
890 if (em) {
891 /*
892 * if block start isn't an actual block number then find the
893 * first block in this inode and use that as a hint. If that
894 * block is also bogus then just don't worry about it.
895 */
896 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
897 free_extent_map(em);
898 em = search_extent_mapping(em_tree, 0, 0);
899 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
900 alloc_hint = em->block_start;
901 if (em)
902 free_extent_map(em);
903 } else {
904 alloc_hint = em->block_start;
905 free_extent_map(em);
906 }
907 }
908 read_unlock(&em_tree->lock);
909
910 return alloc_hint;
911 }
912
913 /*
914 * when extent_io.c finds a delayed allocation range in the file,
915 * the call backs end up in this code. The basic idea is to
916 * allocate extents on disk for the range, and create ordered data structs
917 * in ram to track those extents.
918 *
919 * locked_page is the page that writepage had locked already. We use
920 * it to make sure we don't do extra locks or unlocks.
921 *
922 * *page_started is set to one if we unlock locked_page and do everything
923 * required to start IO on it. It may be clean and already done with
924 * IO when we return.
925 */
926 static noinline int cow_file_range(struct inode *inode,
927 struct page *locked_page,
928 u64 start, u64 end, int *page_started,
929 unsigned long *nr_written,
930 int unlock)
931 {
932 struct btrfs_root *root = BTRFS_I(inode)->root;
933 u64 alloc_hint = 0;
934 u64 num_bytes;
935 unsigned long ram_size;
936 u64 disk_num_bytes;
937 u64 cur_alloc_size;
938 u64 blocksize = root->sectorsize;
939 struct btrfs_key ins;
940 struct extent_map *em;
941 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
942 int ret = 0;
943
944 if (btrfs_is_free_space_inode(inode)) {
945 WARN_ON_ONCE(1);
946 ret = -EINVAL;
947 goto out_unlock;
948 }
949
950 num_bytes = ALIGN(end - start + 1, blocksize);
951 num_bytes = max(blocksize, num_bytes);
952 disk_num_bytes = num_bytes;
953
954 /* if this is a small write inside eof, kick off defrag */
955 if (num_bytes < SZ_64K &&
956 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
957 btrfs_add_inode_defrag(NULL, inode);
958
959 if (start == 0) {
960 /* lets try to make an inline extent */
961 ret = cow_file_range_inline(root, inode, start, end, 0, 0,
962 NULL);
963 if (ret == 0) {
964 extent_clear_unlock_delalloc(inode, start, end, NULL,
965 EXTENT_LOCKED | EXTENT_DELALLOC |
966 EXTENT_DEFRAG, PAGE_UNLOCK |
967 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
968 PAGE_END_WRITEBACK);
969
970 *nr_written = *nr_written +
971 (end - start + PAGE_SIZE) / PAGE_SIZE;
972 *page_started = 1;
973 goto out;
974 } else if (ret < 0) {
975 goto out_unlock;
976 }
977 }
978
979 BUG_ON(disk_num_bytes >
980 btrfs_super_total_bytes(root->fs_info->super_copy));
981
982 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
983 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
984
985 while (disk_num_bytes > 0) {
986 unsigned long op;
987
988 cur_alloc_size = disk_num_bytes;
989 ret = btrfs_reserve_extent(root, cur_alloc_size,
990 root->sectorsize, 0, alloc_hint,
991 &ins, 1, 1);
992 if (ret < 0)
993 goto out_unlock;
994
995 em = alloc_extent_map();
996 if (!em) {
997 ret = -ENOMEM;
998 goto out_reserve;
999 }
1000 em->start = start;
1001 em->orig_start = em->start;
1002 ram_size = ins.offset;
1003 em->len = ins.offset;
1004 em->mod_start = em->start;
1005 em->mod_len = em->len;
1006
1007 em->block_start = ins.objectid;
1008 em->block_len = ins.offset;
1009 em->orig_block_len = ins.offset;
1010 em->ram_bytes = ram_size;
1011 em->bdev = root->fs_info->fs_devices->latest_bdev;
1012 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1013 em->generation = -1;
1014
1015 while (1) {
1016 write_lock(&em_tree->lock);
1017 ret = add_extent_mapping(em_tree, em, 1);
1018 write_unlock(&em_tree->lock);
1019 if (ret != -EEXIST) {
1020 free_extent_map(em);
1021 break;
1022 }
1023 btrfs_drop_extent_cache(inode, start,
1024 start + ram_size - 1, 0);
1025 }
1026 if (ret)
1027 goto out_reserve;
1028
1029 cur_alloc_size = ins.offset;
1030 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
1031 ram_size, cur_alloc_size, 0);
1032 if (ret)
1033 goto out_drop_extent_cache;
1034
1035 if (root->root_key.objectid ==
1036 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1037 ret = btrfs_reloc_clone_csums(inode, start,
1038 cur_alloc_size);
1039 if (ret)
1040 goto out_drop_extent_cache;
1041 }
1042
1043 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
1044
1045 if (disk_num_bytes < cur_alloc_size)
1046 break;
1047
1048 /* we're not doing compressed IO, don't unlock the first
1049 * page (which the caller expects to stay locked), don't
1050 * clear any dirty bits and don't set any writeback bits
1051 *
1052 * Do set the Private2 bit so we know this page was properly
1053 * setup for writepage
1054 */
1055 op = unlock ? PAGE_UNLOCK : 0;
1056 op |= PAGE_SET_PRIVATE2;
1057
1058 extent_clear_unlock_delalloc(inode, start,
1059 start + ram_size - 1, locked_page,
1060 EXTENT_LOCKED | EXTENT_DELALLOC,
1061 op);
1062 disk_num_bytes -= cur_alloc_size;
1063 num_bytes -= cur_alloc_size;
1064 alloc_hint = ins.objectid + ins.offset;
1065 start += cur_alloc_size;
1066 }
1067 out:
1068 return ret;
1069
1070 out_drop_extent_cache:
1071 btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0);
1072 out_reserve:
1073 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
1074 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
1075 out_unlock:
1076 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1077 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
1078 EXTENT_DELALLOC | EXTENT_DEFRAG,
1079 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
1080 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
1081 goto out;
1082 }
1083
1084 /*
1085 * work queue call back to started compression on a file and pages
1086 */
1087 static noinline void async_cow_start(struct btrfs_work *work)
1088 {
1089 struct async_cow *async_cow;
1090 int num_added = 0;
1091 async_cow = container_of(work, struct async_cow, work);
1092
1093 compress_file_range(async_cow->inode, async_cow->locked_page,
1094 async_cow->start, async_cow->end, async_cow,
1095 &num_added);
1096 if (num_added == 0) {
1097 btrfs_add_delayed_iput(async_cow->inode);
1098 async_cow->inode = NULL;
1099 }
1100 }
1101
1102 /*
1103 * work queue call back to submit previously compressed pages
1104 */
1105 static noinline void async_cow_submit(struct btrfs_work *work)
1106 {
1107 struct async_cow *async_cow;
1108 struct btrfs_root *root;
1109 unsigned long nr_pages;
1110
1111 async_cow = container_of(work, struct async_cow, work);
1112
1113 root = async_cow->root;
1114 nr_pages = (async_cow->end - async_cow->start + PAGE_SIZE) >>
1115 PAGE_SHIFT;
1116
1117 /*
1118 * atomic_sub_return implies a barrier for waitqueue_active
1119 */
1120 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1121 5 * SZ_1M &&
1122 waitqueue_active(&root->fs_info->async_submit_wait))
1123 wake_up(&root->fs_info->async_submit_wait);
1124
1125 if (async_cow->inode)
1126 submit_compressed_extents(async_cow->inode, async_cow);
1127 }
1128
1129 static noinline void async_cow_free(struct btrfs_work *work)
1130 {
1131 struct async_cow *async_cow;
1132 async_cow = container_of(work, struct async_cow, work);
1133 if (async_cow->inode)
1134 btrfs_add_delayed_iput(async_cow->inode);
1135 kfree(async_cow);
1136 }
1137
1138 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1139 u64 start, u64 end, int *page_started,
1140 unsigned long *nr_written)
1141 {
1142 struct async_cow *async_cow;
1143 struct btrfs_root *root = BTRFS_I(inode)->root;
1144 unsigned long nr_pages;
1145 u64 cur_end;
1146 int limit = 10 * SZ_1M;
1147
1148 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1149 1, 0, NULL, GFP_NOFS);
1150 while (start < end) {
1151 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1152 BUG_ON(!async_cow); /* -ENOMEM */
1153 async_cow->inode = igrab(inode);
1154 async_cow->root = root;
1155 async_cow->locked_page = locked_page;
1156 async_cow->start = start;
1157
1158 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
1159 !btrfs_test_opt(root, FORCE_COMPRESS))
1160 cur_end = end;
1161 else
1162 cur_end = min(end, start + SZ_512K - 1);
1163
1164 async_cow->end = cur_end;
1165 INIT_LIST_HEAD(&async_cow->extents);
1166
1167 btrfs_init_work(&async_cow->work,
1168 btrfs_delalloc_helper,
1169 async_cow_start, async_cow_submit,
1170 async_cow_free);
1171
1172 nr_pages = (cur_end - start + PAGE_SIZE) >>
1173 PAGE_SHIFT;
1174 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1175
1176 btrfs_queue_work(root->fs_info->delalloc_workers,
1177 &async_cow->work);
1178
1179 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1180 wait_event(root->fs_info->async_submit_wait,
1181 (atomic_read(&root->fs_info->async_delalloc_pages) <
1182 limit));
1183 }
1184
1185 while (atomic_read(&root->fs_info->async_submit_draining) &&
1186 atomic_read(&root->fs_info->async_delalloc_pages)) {
1187 wait_event(root->fs_info->async_submit_wait,
1188 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1189 0));
1190 }
1191
1192 *nr_written += nr_pages;
1193 start = cur_end + 1;
1194 }
1195 *page_started = 1;
1196 return 0;
1197 }
1198
1199 static noinline int csum_exist_in_range(struct btrfs_root *root,
1200 u64 bytenr, u64 num_bytes)
1201 {
1202 int ret;
1203 struct btrfs_ordered_sum *sums;
1204 LIST_HEAD(list);
1205
1206 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1207 bytenr + num_bytes - 1, &list, 0);
1208 if (ret == 0 && list_empty(&list))
1209 return 0;
1210
1211 while (!list_empty(&list)) {
1212 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1213 list_del(&sums->list);
1214 kfree(sums);
1215 }
1216 return 1;
1217 }
1218
1219 /*
1220 * when nowcow writeback call back. This checks for snapshots or COW copies
1221 * of the extents that exist in the file, and COWs the file as required.
1222 *
1223 * If no cow copies or snapshots exist, we write directly to the existing
1224 * blocks on disk
1225 */
1226 static noinline int run_delalloc_nocow(struct inode *inode,
1227 struct page *locked_page,
1228 u64 start, u64 end, int *page_started, int force,
1229 unsigned long *nr_written)
1230 {
1231 struct btrfs_root *root = BTRFS_I(inode)->root;
1232 struct btrfs_trans_handle *trans;
1233 struct extent_buffer *leaf;
1234 struct btrfs_path *path;
1235 struct btrfs_file_extent_item *fi;
1236 struct btrfs_key found_key;
1237 u64 cow_start;
1238 u64 cur_offset;
1239 u64 extent_end;
1240 u64 extent_offset;
1241 u64 disk_bytenr;
1242 u64 num_bytes;
1243 u64 disk_num_bytes;
1244 u64 ram_bytes;
1245 int extent_type;
1246 int ret, err;
1247 int type;
1248 int nocow;
1249 int check_prev = 1;
1250 bool nolock;
1251 u64 ino = btrfs_ino(inode);
1252
1253 path = btrfs_alloc_path();
1254 if (!path) {
1255 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1256 EXTENT_LOCKED | EXTENT_DELALLOC |
1257 EXTENT_DO_ACCOUNTING |
1258 EXTENT_DEFRAG, PAGE_UNLOCK |
1259 PAGE_CLEAR_DIRTY |
1260 PAGE_SET_WRITEBACK |
1261 PAGE_END_WRITEBACK);
1262 return -ENOMEM;
1263 }
1264
1265 nolock = btrfs_is_free_space_inode(inode);
1266
1267 if (nolock)
1268 trans = btrfs_join_transaction_nolock(root);
1269 else
1270 trans = btrfs_join_transaction(root);
1271
1272 if (IS_ERR(trans)) {
1273 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1274 EXTENT_LOCKED | EXTENT_DELALLOC |
1275 EXTENT_DO_ACCOUNTING |
1276 EXTENT_DEFRAG, PAGE_UNLOCK |
1277 PAGE_CLEAR_DIRTY |
1278 PAGE_SET_WRITEBACK |
1279 PAGE_END_WRITEBACK);
1280 btrfs_free_path(path);
1281 return PTR_ERR(trans);
1282 }
1283
1284 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1285
1286 cow_start = (u64)-1;
1287 cur_offset = start;
1288 while (1) {
1289 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1290 cur_offset, 0);
1291 if (ret < 0)
1292 goto error;
1293 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1294 leaf = path->nodes[0];
1295 btrfs_item_key_to_cpu(leaf, &found_key,
1296 path->slots[0] - 1);
1297 if (found_key.objectid == ino &&
1298 found_key.type == BTRFS_EXTENT_DATA_KEY)
1299 path->slots[0]--;
1300 }
1301 check_prev = 0;
1302 next_slot:
1303 leaf = path->nodes[0];
1304 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1305 ret = btrfs_next_leaf(root, path);
1306 if (ret < 0)
1307 goto error;
1308 if (ret > 0)
1309 break;
1310 leaf = path->nodes[0];
1311 }
1312
1313 nocow = 0;
1314 disk_bytenr = 0;
1315 num_bytes = 0;
1316 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1317
1318 if (found_key.objectid > ino)
1319 break;
1320 if (WARN_ON_ONCE(found_key.objectid < ino) ||
1321 found_key.type < BTRFS_EXTENT_DATA_KEY) {
1322 path->slots[0]++;
1323 goto next_slot;
1324 }
1325 if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
1326 found_key.offset > end)
1327 break;
1328
1329 if (found_key.offset > cur_offset) {
1330 extent_end = found_key.offset;
1331 extent_type = 0;
1332 goto out_check;
1333 }
1334
1335 fi = btrfs_item_ptr(leaf, path->slots[0],
1336 struct btrfs_file_extent_item);
1337 extent_type = btrfs_file_extent_type(leaf, fi);
1338
1339 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1340 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1341 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1342 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1343 extent_offset = btrfs_file_extent_offset(leaf, fi);
1344 extent_end = found_key.offset +
1345 btrfs_file_extent_num_bytes(leaf, fi);
1346 disk_num_bytes =
1347 btrfs_file_extent_disk_num_bytes(leaf, fi);
1348 if (extent_end <= start) {
1349 path->slots[0]++;
1350 goto next_slot;
1351 }
1352 if (disk_bytenr == 0)
1353 goto out_check;
1354 if (btrfs_file_extent_compression(leaf, fi) ||
1355 btrfs_file_extent_encryption(leaf, fi) ||
1356 btrfs_file_extent_other_encoding(leaf, fi))
1357 goto out_check;
1358 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1359 goto out_check;
1360 if (btrfs_extent_readonly(root, disk_bytenr))
1361 goto out_check;
1362 if (btrfs_cross_ref_exist(trans, root, ino,
1363 found_key.offset -
1364 extent_offset, disk_bytenr))
1365 goto out_check;
1366 disk_bytenr += extent_offset;
1367 disk_bytenr += cur_offset - found_key.offset;
1368 num_bytes = min(end + 1, extent_end) - cur_offset;
1369 /*
1370 * if there are pending snapshots for this root,
1371 * we fall into common COW way.
1372 */
1373 if (!nolock) {
1374 err = btrfs_start_write_no_snapshoting(root);
1375 if (!err)
1376 goto out_check;
1377 }
1378 /*
1379 * force cow if csum exists in the range.
1380 * this ensure that csum for a given extent are
1381 * either valid or do not exist.
1382 */
1383 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1384 goto out_check;
1385 if (!btrfs_inc_nocow_writers(root->fs_info,
1386 disk_bytenr))
1387 goto out_check;
1388 nocow = 1;
1389 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1390 extent_end = found_key.offset +
1391 btrfs_file_extent_inline_len(leaf,
1392 path->slots[0], fi);
1393 extent_end = ALIGN(extent_end, root->sectorsize);
1394 } else {
1395 BUG_ON(1);
1396 }
1397 out_check:
1398 if (extent_end <= start) {
1399 path->slots[0]++;
1400 if (!nolock && nocow)
1401 btrfs_end_write_no_snapshoting(root);
1402 if (nocow)
1403 btrfs_dec_nocow_writers(root->fs_info,
1404 disk_bytenr);
1405 goto next_slot;
1406 }
1407 if (!nocow) {
1408 if (cow_start == (u64)-1)
1409 cow_start = cur_offset;
1410 cur_offset = extent_end;
1411 if (cur_offset > end)
1412 break;
1413 path->slots[0]++;
1414 goto next_slot;
1415 }
1416
1417 btrfs_release_path(path);
1418 if (cow_start != (u64)-1) {
1419 ret = cow_file_range(inode, locked_page,
1420 cow_start, found_key.offset - 1,
1421 page_started, nr_written, 1);
1422 if (ret) {
1423 if (!nolock && nocow)
1424 btrfs_end_write_no_snapshoting(root);
1425 if (nocow)
1426 btrfs_dec_nocow_writers(root->fs_info,
1427 disk_bytenr);
1428 goto error;
1429 }
1430 cow_start = (u64)-1;
1431 }
1432
1433 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1434 struct extent_map *em;
1435 struct extent_map_tree *em_tree;
1436 em_tree = &BTRFS_I(inode)->extent_tree;
1437 em = alloc_extent_map();
1438 BUG_ON(!em); /* -ENOMEM */
1439 em->start = cur_offset;
1440 em->orig_start = found_key.offset - extent_offset;
1441 em->len = num_bytes;
1442 em->block_len = num_bytes;
1443 em->block_start = disk_bytenr;
1444 em->orig_block_len = disk_num_bytes;
1445 em->ram_bytes = ram_bytes;
1446 em->bdev = root->fs_info->fs_devices->latest_bdev;
1447 em->mod_start = em->start;
1448 em->mod_len = em->len;
1449 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1450 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1451 em->generation = -1;
1452 while (1) {
1453 write_lock(&em_tree->lock);
1454 ret = add_extent_mapping(em_tree, em, 1);
1455 write_unlock(&em_tree->lock);
1456 if (ret != -EEXIST) {
1457 free_extent_map(em);
1458 break;
1459 }
1460 btrfs_drop_extent_cache(inode, em->start,
1461 em->start + em->len - 1, 0);
1462 }
1463 type = BTRFS_ORDERED_PREALLOC;
1464 } else {
1465 type = BTRFS_ORDERED_NOCOW;
1466 }
1467
1468 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1469 num_bytes, num_bytes, type);
1470 if (nocow)
1471 btrfs_dec_nocow_writers(root->fs_info, disk_bytenr);
1472 BUG_ON(ret); /* -ENOMEM */
1473
1474 if (root->root_key.objectid ==
1475 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1476 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1477 num_bytes);
1478 if (ret) {
1479 if (!nolock && nocow)
1480 btrfs_end_write_no_snapshoting(root);
1481 goto error;
1482 }
1483 }
1484
1485 extent_clear_unlock_delalloc(inode, cur_offset,
1486 cur_offset + num_bytes - 1,
1487 locked_page, EXTENT_LOCKED |
1488 EXTENT_DELALLOC, PAGE_UNLOCK |
1489 PAGE_SET_PRIVATE2);
1490 if (!nolock && nocow)
1491 btrfs_end_write_no_snapshoting(root);
1492 cur_offset = extent_end;
1493 if (cur_offset > end)
1494 break;
1495 }
1496 btrfs_release_path(path);
1497
1498 if (cur_offset <= end && cow_start == (u64)-1) {
1499 cow_start = cur_offset;
1500 cur_offset = end;
1501 }
1502
1503 if (cow_start != (u64)-1) {
1504 ret = cow_file_range(inode, locked_page, cow_start, end,
1505 page_started, nr_written, 1);
1506 if (ret)
1507 goto error;
1508 }
1509
1510 error:
1511 err = btrfs_end_transaction(trans, root);
1512 if (!ret)
1513 ret = err;
1514
1515 if (ret && cur_offset < end)
1516 extent_clear_unlock_delalloc(inode, cur_offset, end,
1517 locked_page, EXTENT_LOCKED |
1518 EXTENT_DELALLOC | EXTENT_DEFRAG |
1519 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1520 PAGE_CLEAR_DIRTY |
1521 PAGE_SET_WRITEBACK |
1522 PAGE_END_WRITEBACK);
1523 btrfs_free_path(path);
1524 return ret;
1525 }
1526
1527 static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
1528 {
1529
1530 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
1531 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
1532 return 0;
1533
1534 /*
1535 * @defrag_bytes is a hint value, no spinlock held here,
1536 * if is not zero, it means the file is defragging.
1537 * Force cow if given extent needs to be defragged.
1538 */
1539 if (BTRFS_I(inode)->defrag_bytes &&
1540 test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1541 EXTENT_DEFRAG, 0, NULL))
1542 return 1;
1543
1544 return 0;
1545 }
1546
1547 /*
1548 * extent_io.c call back to do delayed allocation processing
1549 */
1550 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1551 u64 start, u64 end, int *page_started,
1552 unsigned long *nr_written)
1553 {
1554 int ret;
1555 int force_cow = need_force_cow(inode, start, end);
1556
1557 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
1558 ret = run_delalloc_nocow(inode, locked_page, start, end,
1559 page_started, 1, nr_written);
1560 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
1561 ret = run_delalloc_nocow(inode, locked_page, start, end,
1562 page_started, 0, nr_written);
1563 } else if (!inode_need_compress(inode)) {
1564 ret = cow_file_range(inode, locked_page, start, end,
1565 page_started, nr_written, 1);
1566 } else {
1567 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1568 &BTRFS_I(inode)->runtime_flags);
1569 ret = cow_file_range_async(inode, locked_page, start, end,
1570 page_started, nr_written);
1571 }
1572 return ret;
1573 }
1574
1575 static void btrfs_split_extent_hook(struct inode *inode,
1576 struct extent_state *orig, u64 split)
1577 {
1578 u64 size;
1579
1580 /* not delalloc, ignore it */
1581 if (!(orig->state & EXTENT_DELALLOC))
1582 return;
1583
1584 size = orig->end - orig->start + 1;
1585 if (size > BTRFS_MAX_EXTENT_SIZE) {
1586 u64 num_extents;
1587 u64 new_size;
1588
1589 /*
1590 * See the explanation in btrfs_merge_extent_hook, the same
1591 * applies here, just in reverse.
1592 */
1593 new_size = orig->end - split + 1;
1594 num_extents = div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1595 BTRFS_MAX_EXTENT_SIZE);
1596 new_size = split - orig->start;
1597 num_extents += div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1598 BTRFS_MAX_EXTENT_SIZE);
1599 if (div64_u64(size + BTRFS_MAX_EXTENT_SIZE - 1,
1600 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1601 return;
1602 }
1603
1604 spin_lock(&BTRFS_I(inode)->lock);
1605 BTRFS_I(inode)->outstanding_extents++;
1606 spin_unlock(&BTRFS_I(inode)->lock);
1607 }
1608
1609 /*
1610 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1611 * extents so we can keep track of new extents that are just merged onto old
1612 * extents, such as when we are doing sequential writes, so we can properly
1613 * account for the metadata space we'll need.
1614 */
1615 static void btrfs_merge_extent_hook(struct inode *inode,
1616 struct extent_state *new,
1617 struct extent_state *other)
1618 {
1619 u64 new_size, old_size;
1620 u64 num_extents;
1621
1622 /* not delalloc, ignore it */
1623 if (!(other->state & EXTENT_DELALLOC))
1624 return;
1625
1626 if (new->start > other->start)
1627 new_size = new->end - other->start + 1;
1628 else
1629 new_size = other->end - new->start + 1;
1630
1631 /* we're not bigger than the max, unreserve the space and go */
1632 if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
1633 spin_lock(&BTRFS_I(inode)->lock);
1634 BTRFS_I(inode)->outstanding_extents--;
1635 spin_unlock(&BTRFS_I(inode)->lock);
1636 return;
1637 }
1638
1639 /*
1640 * We have to add up either side to figure out how many extents were
1641 * accounted for before we merged into one big extent. If the number of
1642 * extents we accounted for is <= the amount we need for the new range
1643 * then we can return, otherwise drop. Think of it like this
1644 *
1645 * [ 4k][MAX_SIZE]
1646 *
1647 * So we've grown the extent by a MAX_SIZE extent, this would mean we
1648 * need 2 outstanding extents, on one side we have 1 and the other side
1649 * we have 1 so they are == and we can return. But in this case
1650 *
1651 * [MAX_SIZE+4k][MAX_SIZE+4k]
1652 *
1653 * Each range on their own accounts for 2 extents, but merged together
1654 * they are only 3 extents worth of accounting, so we need to drop in
1655 * this case.
1656 */
1657 old_size = other->end - other->start + 1;
1658 num_extents = div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1659 BTRFS_MAX_EXTENT_SIZE);
1660 old_size = new->end - new->start + 1;
1661 num_extents += div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1662 BTRFS_MAX_EXTENT_SIZE);
1663
1664 if (div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1665 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1666 return;
1667
1668 spin_lock(&BTRFS_I(inode)->lock);
1669 BTRFS_I(inode)->outstanding_extents--;
1670 spin_unlock(&BTRFS_I(inode)->lock);
1671 }
1672
1673 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1674 struct inode *inode)
1675 {
1676 spin_lock(&root->delalloc_lock);
1677 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1678 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1679 &root->delalloc_inodes);
1680 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1681 &BTRFS_I(inode)->runtime_flags);
1682 root->nr_delalloc_inodes++;
1683 if (root->nr_delalloc_inodes == 1) {
1684 spin_lock(&root->fs_info->delalloc_root_lock);
1685 BUG_ON(!list_empty(&root->delalloc_root));
1686 list_add_tail(&root->delalloc_root,
1687 &root->fs_info->delalloc_roots);
1688 spin_unlock(&root->fs_info->delalloc_root_lock);
1689 }
1690 }
1691 spin_unlock(&root->delalloc_lock);
1692 }
1693
1694 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1695 struct inode *inode)
1696 {
1697 spin_lock(&root->delalloc_lock);
1698 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1699 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1700 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1701 &BTRFS_I(inode)->runtime_flags);
1702 root->nr_delalloc_inodes--;
1703 if (!root->nr_delalloc_inodes) {
1704 spin_lock(&root->fs_info->delalloc_root_lock);
1705 BUG_ON(list_empty(&root->delalloc_root));
1706 list_del_init(&root->delalloc_root);
1707 spin_unlock(&root->fs_info->delalloc_root_lock);
1708 }
1709 }
1710 spin_unlock(&root->delalloc_lock);
1711 }
1712
1713 /*
1714 * extent_io.c set_bit_hook, used to track delayed allocation
1715 * bytes in this file, and to maintain the list of inodes that
1716 * have pending delalloc work to be done.
1717 */
1718 static void btrfs_set_bit_hook(struct inode *inode,
1719 struct extent_state *state, unsigned *bits)
1720 {
1721
1722 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
1723 WARN_ON(1);
1724 /*
1725 * set_bit and clear bit hooks normally require _irqsave/restore
1726 * but in this case, we are only testing for the DELALLOC
1727 * bit, which is only set or cleared with irqs on
1728 */
1729 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1730 struct btrfs_root *root = BTRFS_I(inode)->root;
1731 u64 len = state->end + 1 - state->start;
1732 bool do_list = !btrfs_is_free_space_inode(inode);
1733
1734 if (*bits & EXTENT_FIRST_DELALLOC) {
1735 *bits &= ~EXTENT_FIRST_DELALLOC;
1736 } else {
1737 spin_lock(&BTRFS_I(inode)->lock);
1738 BTRFS_I(inode)->outstanding_extents++;
1739 spin_unlock(&BTRFS_I(inode)->lock);
1740 }
1741
1742 /* For sanity tests */
1743 if (btrfs_test_is_dummy_root(root))
1744 return;
1745
1746 __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
1747 root->fs_info->delalloc_batch);
1748 spin_lock(&BTRFS_I(inode)->lock);
1749 BTRFS_I(inode)->delalloc_bytes += len;
1750 if (*bits & EXTENT_DEFRAG)
1751 BTRFS_I(inode)->defrag_bytes += len;
1752 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1753 &BTRFS_I(inode)->runtime_flags))
1754 btrfs_add_delalloc_inodes(root, inode);
1755 spin_unlock(&BTRFS_I(inode)->lock);
1756 }
1757 }
1758
1759 /*
1760 * extent_io.c clear_bit_hook, see set_bit_hook for why
1761 */
1762 static void btrfs_clear_bit_hook(struct inode *inode,
1763 struct extent_state *state,
1764 unsigned *bits)
1765 {
1766 u64 len = state->end + 1 - state->start;
1767 u64 num_extents = div64_u64(len + BTRFS_MAX_EXTENT_SIZE -1,
1768 BTRFS_MAX_EXTENT_SIZE);
1769
1770 spin_lock(&BTRFS_I(inode)->lock);
1771 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG))
1772 BTRFS_I(inode)->defrag_bytes -= len;
1773 spin_unlock(&BTRFS_I(inode)->lock);
1774
1775 /*
1776 * set_bit and clear bit hooks normally require _irqsave/restore
1777 * but in this case, we are only testing for the DELALLOC
1778 * bit, which is only set or cleared with irqs on
1779 */
1780 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1781 struct btrfs_root *root = BTRFS_I(inode)->root;
1782 bool do_list = !btrfs_is_free_space_inode(inode);
1783
1784 if (*bits & EXTENT_FIRST_DELALLOC) {
1785 *bits &= ~EXTENT_FIRST_DELALLOC;
1786 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1787 spin_lock(&BTRFS_I(inode)->lock);
1788 BTRFS_I(inode)->outstanding_extents -= num_extents;
1789 spin_unlock(&BTRFS_I(inode)->lock);
1790 }
1791
1792 /*
1793 * We don't reserve metadata space for space cache inodes so we
1794 * don't need to call dellalloc_release_metadata if there is an
1795 * error.
1796 */
1797 if (*bits & EXTENT_DO_ACCOUNTING &&
1798 root != root->fs_info->tree_root)
1799 btrfs_delalloc_release_metadata(inode, len);
1800
1801 /* For sanity tests. */
1802 if (btrfs_test_is_dummy_root(root))
1803 return;
1804
1805 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1806 && do_list && !(state->state & EXTENT_NORESERVE))
1807 btrfs_free_reserved_data_space_noquota(inode,
1808 state->start, len);
1809
1810 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
1811 root->fs_info->delalloc_batch);
1812 spin_lock(&BTRFS_I(inode)->lock);
1813 BTRFS_I(inode)->delalloc_bytes -= len;
1814 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1815 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1816 &BTRFS_I(inode)->runtime_flags))
1817 btrfs_del_delalloc_inode(root, inode);
1818 spin_unlock(&BTRFS_I(inode)->lock);
1819 }
1820 }
1821
1822 /*
1823 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1824 * we don't create bios that span stripes or chunks
1825 */
1826 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
1827 size_t size, struct bio *bio,
1828 unsigned long bio_flags)
1829 {
1830 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1831 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1832 u64 length = 0;
1833 u64 map_length;
1834 int ret;
1835
1836 if (bio_flags & EXTENT_BIO_COMPRESSED)
1837 return 0;
1838
1839 length = bio->bi_iter.bi_size;
1840 map_length = length;
1841 ret = btrfs_map_block(root->fs_info, rw, logical,
1842 &map_length, NULL, 0);
1843 /* Will always return 0 with map_multi == NULL */
1844 BUG_ON(ret < 0);
1845 if (map_length < length + size)
1846 return 1;
1847 return 0;
1848 }
1849
1850 /*
1851 * in order to insert checksums into the metadata in large chunks,
1852 * we wait until bio submission time. All the pages in the bio are
1853 * checksummed and sums are attached onto the ordered extent record.
1854 *
1855 * At IO completion time the cums attached on the ordered extent record
1856 * are inserted into the btree
1857 */
1858 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1859 struct bio *bio, int mirror_num,
1860 unsigned long bio_flags,
1861 u64 bio_offset)
1862 {
1863 struct btrfs_root *root = BTRFS_I(inode)->root;
1864 int ret = 0;
1865
1866 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1867 BUG_ON(ret); /* -ENOMEM */
1868 return 0;
1869 }
1870
1871 /*
1872 * in order to insert checksums into the metadata in large chunks,
1873 * we wait until bio submission time. All the pages in the bio are
1874 * checksummed and sums are attached onto the ordered extent record.
1875 *
1876 * At IO completion time the cums attached on the ordered extent record
1877 * are inserted into the btree
1878 */
1879 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1880 int mirror_num, unsigned long bio_flags,
1881 u64 bio_offset)
1882 {
1883 struct btrfs_root *root = BTRFS_I(inode)->root;
1884 int ret;
1885
1886 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
1887 if (ret) {
1888 bio->bi_error = ret;
1889 bio_endio(bio);
1890 }
1891 return ret;
1892 }
1893
1894 /*
1895 * extent_io.c submission hook. This does the right thing for csum calculation
1896 * on write, or reading the csums from the tree before a read
1897 */
1898 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1899 int mirror_num, unsigned long bio_flags,
1900 u64 bio_offset)
1901 {
1902 struct btrfs_root *root = BTRFS_I(inode)->root;
1903 enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
1904 int ret = 0;
1905 int skip_sum;
1906 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1907
1908 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1909
1910 if (btrfs_is_free_space_inode(inode))
1911 metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
1912
1913 if (!(rw & REQ_WRITE)) {
1914 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1915 if (ret)
1916 goto out;
1917
1918 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1919 ret = btrfs_submit_compressed_read(inode, bio,
1920 mirror_num,
1921 bio_flags);
1922 goto out;
1923 } else if (!skip_sum) {
1924 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1925 if (ret)
1926 goto out;
1927 }
1928 goto mapit;
1929 } else if (async && !skip_sum) {
1930 /* csum items have already been cloned */
1931 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1932 goto mapit;
1933 /* we're doing a write, do the async checksumming */
1934 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1935 inode, rw, bio, mirror_num,
1936 bio_flags, bio_offset,
1937 __btrfs_submit_bio_start,
1938 __btrfs_submit_bio_done);
1939 goto out;
1940 } else if (!skip_sum) {
1941 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1942 if (ret)
1943 goto out;
1944 }
1945
1946 mapit:
1947 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
1948
1949 out:
1950 if (ret < 0) {
1951 bio->bi_error = ret;
1952 bio_endio(bio);
1953 }
1954 return ret;
1955 }
1956
1957 /*
1958 * given a list of ordered sums record them in the inode. This happens
1959 * at IO completion time based on sums calculated at bio submission time.
1960 */
1961 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1962 struct inode *inode, u64 file_offset,
1963 struct list_head *list)
1964 {
1965 struct btrfs_ordered_sum *sum;
1966
1967 list_for_each_entry(sum, list, list) {
1968 trans->adding_csums = 1;
1969 btrfs_csum_file_blocks(trans,
1970 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1971 trans->adding_csums = 0;
1972 }
1973 return 0;
1974 }
1975
1976 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1977 struct extent_state **cached_state)
1978 {
1979 WARN_ON((end & (PAGE_SIZE - 1)) == 0);
1980 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1981 cached_state);
1982 }
1983
1984 /* see btrfs_writepage_start_hook for details on why this is required */
1985 struct btrfs_writepage_fixup {
1986 struct page *page;
1987 struct btrfs_work work;
1988 };
1989
1990 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1991 {
1992 struct btrfs_writepage_fixup *fixup;
1993 struct btrfs_ordered_extent *ordered;
1994 struct extent_state *cached_state = NULL;
1995 struct page *page;
1996 struct inode *inode;
1997 u64 page_start;
1998 u64 page_end;
1999 int ret;
2000
2001 fixup = container_of(work, struct btrfs_writepage_fixup, work);
2002 page = fixup->page;
2003 again:
2004 lock_page(page);
2005 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
2006 ClearPageChecked(page);
2007 goto out_page;
2008 }
2009
2010 inode = page->mapping->host;
2011 page_start = page_offset(page);
2012 page_end = page_offset(page) + PAGE_SIZE - 1;
2013
2014 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
2015 &cached_state);
2016
2017 /* already ordered? We're done */
2018 if (PagePrivate2(page))
2019 goto out;
2020
2021 ordered = btrfs_lookup_ordered_range(inode, page_start,
2022 PAGE_SIZE);
2023 if (ordered) {
2024 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
2025 page_end, &cached_state, GFP_NOFS);
2026 unlock_page(page);
2027 btrfs_start_ordered_extent(inode, ordered, 1);
2028 btrfs_put_ordered_extent(ordered);
2029 goto again;
2030 }
2031
2032 ret = btrfs_delalloc_reserve_space(inode, page_start,
2033 PAGE_SIZE);
2034 if (ret) {
2035 mapping_set_error(page->mapping, ret);
2036 end_extent_writepage(page, ret, page_start, page_end);
2037 ClearPageChecked(page);
2038 goto out;
2039 }
2040
2041 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
2042 ClearPageChecked(page);
2043 set_page_dirty(page);
2044 out:
2045 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
2046 &cached_state, GFP_NOFS);
2047 out_page:
2048 unlock_page(page);
2049 put_page(page);
2050 kfree(fixup);
2051 }
2052
2053 /*
2054 * There are a few paths in the higher layers of the kernel that directly
2055 * set the page dirty bit without asking the filesystem if it is a
2056 * good idea. This causes problems because we want to make sure COW
2057 * properly happens and the data=ordered rules are followed.
2058 *
2059 * In our case any range that doesn't have the ORDERED bit set
2060 * hasn't been properly setup for IO. We kick off an async process
2061 * to fix it up. The async helper will wait for ordered extents, set
2062 * the delalloc bit and make it safe to write the page.
2063 */
2064 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
2065 {
2066 struct inode *inode = page->mapping->host;
2067 struct btrfs_writepage_fixup *fixup;
2068 struct btrfs_root *root = BTRFS_I(inode)->root;
2069
2070 /* this page is properly in the ordered list */
2071 if (TestClearPagePrivate2(page))
2072 return 0;
2073
2074 if (PageChecked(page))
2075 return -EAGAIN;
2076
2077 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
2078 if (!fixup)
2079 return -EAGAIN;
2080
2081 SetPageChecked(page);
2082 get_page(page);
2083 btrfs_init_work(&fixup->work, btrfs_fixup_helper,
2084 btrfs_writepage_fixup_worker, NULL, NULL);
2085 fixup->page = page;
2086 btrfs_queue_work(root->fs_info->fixup_workers, &fixup->work);
2087 return -EBUSY;
2088 }
2089
2090 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
2091 struct inode *inode, u64 file_pos,
2092 u64 disk_bytenr, u64 disk_num_bytes,
2093 u64 num_bytes, u64 ram_bytes,
2094 u8 compression, u8 encryption,
2095 u16 other_encoding, int extent_type)
2096 {
2097 struct btrfs_root *root = BTRFS_I(inode)->root;
2098 struct btrfs_file_extent_item *fi;
2099 struct btrfs_path *path;
2100 struct extent_buffer *leaf;
2101 struct btrfs_key ins;
2102 int extent_inserted = 0;
2103 int ret;
2104
2105 path = btrfs_alloc_path();
2106 if (!path)
2107 return -ENOMEM;
2108
2109 /*
2110 * we may be replacing one extent in the tree with another.
2111 * The new extent is pinned in the extent map, and we don't want
2112 * to drop it from the cache until it is completely in the btree.
2113 *
2114 * So, tell btrfs_drop_extents to leave this extent in the cache.
2115 * the caller is expected to unpin it and allow it to be merged
2116 * with the others.
2117 */
2118 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
2119 file_pos + num_bytes, NULL, 0,
2120 1, sizeof(*fi), &extent_inserted);
2121 if (ret)
2122 goto out;
2123
2124 if (!extent_inserted) {
2125 ins.objectid = btrfs_ino(inode);
2126 ins.offset = file_pos;
2127 ins.type = BTRFS_EXTENT_DATA_KEY;
2128
2129 path->leave_spinning = 1;
2130 ret = btrfs_insert_empty_item(trans, root, path, &ins,
2131 sizeof(*fi));
2132 if (ret)
2133 goto out;
2134 }
2135 leaf = path->nodes[0];
2136 fi = btrfs_item_ptr(leaf, path->slots[0],
2137 struct btrfs_file_extent_item);
2138 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2139 btrfs_set_file_extent_type(leaf, fi, extent_type);
2140 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
2141 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
2142 btrfs_set_file_extent_offset(leaf, fi, 0);
2143 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2144 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
2145 btrfs_set_file_extent_compression(leaf, fi, compression);
2146 btrfs_set_file_extent_encryption(leaf, fi, encryption);
2147 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
2148
2149 btrfs_mark_buffer_dirty(leaf);
2150 btrfs_release_path(path);
2151
2152 inode_add_bytes(inode, num_bytes);
2153
2154 ins.objectid = disk_bytenr;
2155 ins.offset = disk_num_bytes;
2156 ins.type = BTRFS_EXTENT_ITEM_KEY;
2157 ret = btrfs_alloc_reserved_file_extent(trans, root,
2158 root->root_key.objectid,
2159 btrfs_ino(inode), file_pos,
2160 ram_bytes, &ins);
2161 /*
2162 * Release the reserved range from inode dirty range map, as it is
2163 * already moved into delayed_ref_head
2164 */
2165 btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
2166 out:
2167 btrfs_free_path(path);
2168
2169 return ret;
2170 }
2171
2172 /* snapshot-aware defrag */
2173 struct sa_defrag_extent_backref {
2174 struct rb_node node;
2175 struct old_sa_defrag_extent *old;
2176 u64 root_id;
2177 u64 inum;
2178 u64 file_pos;
2179 u64 extent_offset;
2180 u64 num_bytes;
2181 u64 generation;
2182 };
2183
2184 struct old_sa_defrag_extent {
2185 struct list_head list;
2186 struct new_sa_defrag_extent *new;
2187
2188 u64 extent_offset;
2189 u64 bytenr;
2190 u64 offset;
2191 u64 len;
2192 int count;
2193 };
2194
2195 struct new_sa_defrag_extent {
2196 struct rb_root root;
2197 struct list_head head;
2198 struct btrfs_path *path;
2199 struct inode *inode;
2200 u64 file_pos;
2201 u64 len;
2202 u64 bytenr;
2203 u64 disk_len;
2204 u8 compress_type;
2205 };
2206
2207 static int backref_comp(struct sa_defrag_extent_backref *b1,
2208 struct sa_defrag_extent_backref *b2)
2209 {
2210 if (b1->root_id < b2->root_id)
2211 return -1;
2212 else if (b1->root_id > b2->root_id)
2213 return 1;
2214
2215 if (b1->inum < b2->inum)
2216 return -1;
2217 else if (b1->inum > b2->inum)
2218 return 1;
2219
2220 if (b1->file_pos < b2->file_pos)
2221 return -1;
2222 else if (b1->file_pos > b2->file_pos)
2223 return 1;
2224
2225 /*
2226 * [------------------------------] ===> (a range of space)
2227 * |<--->| |<---->| =============> (fs/file tree A)
2228 * |<---------------------------->| ===> (fs/file tree B)
2229 *
2230 * A range of space can refer to two file extents in one tree while
2231 * refer to only one file extent in another tree.
2232 *
2233 * So we may process a disk offset more than one time(two extents in A)
2234 * and locate at the same extent(one extent in B), then insert two same
2235 * backrefs(both refer to the extent in B).
2236 */
2237 return 0;
2238 }
2239
2240 static void backref_insert(struct rb_root *root,
2241 struct sa_defrag_extent_backref *backref)
2242 {
2243 struct rb_node **p = &root->rb_node;
2244 struct rb_node *parent = NULL;
2245 struct sa_defrag_extent_backref *entry;
2246 int ret;
2247
2248 while (*p) {
2249 parent = *p;
2250 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2251
2252 ret = backref_comp(backref, entry);
2253 if (ret < 0)
2254 p = &(*p)->rb_left;
2255 else
2256 p = &(*p)->rb_right;
2257 }
2258
2259 rb_link_node(&backref->node, parent, p);
2260 rb_insert_color(&backref->node, root);
2261 }
2262
2263 /*
2264 * Note the backref might has changed, and in this case we just return 0.
2265 */
2266 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2267 void *ctx)
2268 {
2269 struct btrfs_file_extent_item *extent;
2270 struct btrfs_fs_info *fs_info;
2271 struct old_sa_defrag_extent *old = ctx;
2272 struct new_sa_defrag_extent *new = old->new;
2273 struct btrfs_path *path = new->path;
2274 struct btrfs_key key;
2275 struct btrfs_root *root;
2276 struct sa_defrag_extent_backref *backref;
2277 struct extent_buffer *leaf;
2278 struct inode *inode = new->inode;
2279 int slot;
2280 int ret;
2281 u64 extent_offset;
2282 u64 num_bytes;
2283
2284 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2285 inum == btrfs_ino(inode))
2286 return 0;
2287
2288 key.objectid = root_id;
2289 key.type = BTRFS_ROOT_ITEM_KEY;
2290 key.offset = (u64)-1;
2291
2292 fs_info = BTRFS_I(inode)->root->fs_info;
2293 root = btrfs_read_fs_root_no_name(fs_info, &key);
2294 if (IS_ERR(root)) {
2295 if (PTR_ERR(root) == -ENOENT)
2296 return 0;
2297 WARN_ON(1);
2298 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
2299 inum, offset, root_id);
2300 return PTR_ERR(root);
2301 }
2302
2303 key.objectid = inum;
2304 key.type = BTRFS_EXTENT_DATA_KEY;
2305 if (offset > (u64)-1 << 32)
2306 key.offset = 0;
2307 else
2308 key.offset = offset;
2309
2310 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2311 if (WARN_ON(ret < 0))
2312 return ret;
2313 ret = 0;
2314
2315 while (1) {
2316 cond_resched();
2317
2318 leaf = path->nodes[0];
2319 slot = path->slots[0];
2320
2321 if (slot >= btrfs_header_nritems(leaf)) {
2322 ret = btrfs_next_leaf(root, path);
2323 if (ret < 0) {
2324 goto out;
2325 } else if (ret > 0) {
2326 ret = 0;
2327 goto out;
2328 }
2329 continue;
2330 }
2331
2332 path->slots[0]++;
2333
2334 btrfs_item_key_to_cpu(leaf, &key, slot);
2335
2336 if (key.objectid > inum)
2337 goto out;
2338
2339 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2340 continue;
2341
2342 extent = btrfs_item_ptr(leaf, slot,
2343 struct btrfs_file_extent_item);
2344
2345 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2346 continue;
2347
2348 /*
2349 * 'offset' refers to the exact key.offset,
2350 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2351 * (key.offset - extent_offset).
2352 */
2353 if (key.offset != offset)
2354 continue;
2355
2356 extent_offset = btrfs_file_extent_offset(leaf, extent);
2357 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2358
2359 if (extent_offset >= old->extent_offset + old->offset +
2360 old->len || extent_offset + num_bytes <=
2361 old->extent_offset + old->offset)
2362 continue;
2363 break;
2364 }
2365
2366 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2367 if (!backref) {
2368 ret = -ENOENT;
2369 goto out;
2370 }
2371
2372 backref->root_id = root_id;
2373 backref->inum = inum;
2374 backref->file_pos = offset;
2375 backref->num_bytes = num_bytes;
2376 backref->extent_offset = extent_offset;
2377 backref->generation = btrfs_file_extent_generation(leaf, extent);
2378 backref->old = old;
2379 backref_insert(&new->root, backref);
2380 old->count++;
2381 out:
2382 btrfs_release_path(path);
2383 WARN_ON(ret);
2384 return ret;
2385 }
2386
2387 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2388 struct new_sa_defrag_extent *new)
2389 {
2390 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
2391 struct old_sa_defrag_extent *old, *tmp;
2392 int ret;
2393
2394 new->path = path;
2395
2396 list_for_each_entry_safe(old, tmp, &new->head, list) {
2397 ret = iterate_inodes_from_logical(old->bytenr +
2398 old->extent_offset, fs_info,
2399 path, record_one_backref,
2400 old);
2401 if (ret < 0 && ret != -ENOENT)
2402 return false;
2403
2404 /* no backref to be processed for this extent */
2405 if (!old->count) {
2406 list_del(&old->list);
2407 kfree(old);
2408 }
2409 }
2410
2411 if (list_empty(&new->head))
2412 return false;
2413
2414 return true;
2415 }
2416
2417 static int relink_is_mergable(struct extent_buffer *leaf,
2418 struct btrfs_file_extent_item *fi,
2419 struct new_sa_defrag_extent *new)
2420 {
2421 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2422 return 0;
2423
2424 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2425 return 0;
2426
2427 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2428 return 0;
2429
2430 if (btrfs_file_extent_encryption(leaf, fi) ||
2431 btrfs_file_extent_other_encoding(leaf, fi))
2432 return 0;
2433
2434 return 1;
2435 }
2436
2437 /*
2438 * Note the backref might has changed, and in this case we just return 0.
2439 */
2440 static noinline int relink_extent_backref(struct btrfs_path *path,
2441 struct sa_defrag_extent_backref *prev,
2442 struct sa_defrag_extent_backref *backref)
2443 {
2444 struct btrfs_file_extent_item *extent;
2445 struct btrfs_file_extent_item *item;
2446 struct btrfs_ordered_extent *ordered;
2447 struct btrfs_trans_handle *trans;
2448 struct btrfs_fs_info *fs_info;
2449 struct btrfs_root *root;
2450 struct btrfs_key key;
2451 struct extent_buffer *leaf;
2452 struct old_sa_defrag_extent *old = backref->old;
2453 struct new_sa_defrag_extent *new = old->new;
2454 struct inode *src_inode = new->inode;
2455 struct inode *inode;
2456 struct extent_state *cached = NULL;
2457 int ret = 0;
2458 u64 start;
2459 u64 len;
2460 u64 lock_start;
2461 u64 lock_end;
2462 bool merge = false;
2463 int index;
2464
2465 if (prev && prev->root_id == backref->root_id &&
2466 prev->inum == backref->inum &&
2467 prev->file_pos + prev->num_bytes == backref->file_pos)
2468 merge = true;
2469
2470 /* step 1: get root */
2471 key.objectid = backref->root_id;
2472 key.type = BTRFS_ROOT_ITEM_KEY;
2473 key.offset = (u64)-1;
2474
2475 fs_info = BTRFS_I(src_inode)->root->fs_info;
2476 index = srcu_read_lock(&fs_info->subvol_srcu);
2477
2478 root = btrfs_read_fs_root_no_name(fs_info, &key);
2479 if (IS_ERR(root)) {
2480 srcu_read_unlock(&fs_info->subvol_srcu, index);
2481 if (PTR_ERR(root) == -ENOENT)
2482 return 0;
2483 return PTR_ERR(root);
2484 }
2485
2486 if (btrfs_root_readonly(root)) {
2487 srcu_read_unlock(&fs_info->subvol_srcu, index);
2488 return 0;
2489 }
2490
2491 /* step 2: get inode */
2492 key.objectid = backref->inum;
2493 key.type = BTRFS_INODE_ITEM_KEY;
2494 key.offset = 0;
2495
2496 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2497 if (IS_ERR(inode)) {
2498 srcu_read_unlock(&fs_info->subvol_srcu, index);
2499 return 0;
2500 }
2501
2502 srcu_read_unlock(&fs_info->subvol_srcu, index);
2503
2504 /* step 3: relink backref */
2505 lock_start = backref->file_pos;
2506 lock_end = backref->file_pos + backref->num_bytes - 1;
2507 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2508 &cached);
2509
2510 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2511 if (ordered) {
2512 btrfs_put_ordered_extent(ordered);
2513 goto out_unlock;
2514 }
2515
2516 trans = btrfs_join_transaction(root);
2517 if (IS_ERR(trans)) {
2518 ret = PTR_ERR(trans);
2519 goto out_unlock;
2520 }
2521
2522 key.objectid = backref->inum;
2523 key.type = BTRFS_EXTENT_DATA_KEY;
2524 key.offset = backref->file_pos;
2525
2526 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2527 if (ret < 0) {
2528 goto out_free_path;
2529 } else if (ret > 0) {
2530 ret = 0;
2531 goto out_free_path;
2532 }
2533
2534 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2535 struct btrfs_file_extent_item);
2536
2537 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2538 backref->generation)
2539 goto out_free_path;
2540
2541 btrfs_release_path(path);
2542
2543 start = backref->file_pos;
2544 if (backref->extent_offset < old->extent_offset + old->offset)
2545 start += old->extent_offset + old->offset -
2546 backref->extent_offset;
2547
2548 len = min(backref->extent_offset + backref->num_bytes,
2549 old->extent_offset + old->offset + old->len);
2550 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2551
2552 ret = btrfs_drop_extents(trans, root, inode, start,
2553 start + len, 1);
2554 if (ret)
2555 goto out_free_path;
2556 again:
2557 key.objectid = btrfs_ino(inode);
2558 key.type = BTRFS_EXTENT_DATA_KEY;
2559 key.offset = start;
2560
2561 path->leave_spinning = 1;
2562 if (merge) {
2563 struct btrfs_file_extent_item *fi;
2564 u64 extent_len;
2565 struct btrfs_key found_key;
2566
2567 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2568 if (ret < 0)
2569 goto out_free_path;
2570
2571 path->slots[0]--;
2572 leaf = path->nodes[0];
2573 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2574
2575 fi = btrfs_item_ptr(leaf, path->slots[0],
2576 struct btrfs_file_extent_item);
2577 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2578
2579 if (extent_len + found_key.offset == start &&
2580 relink_is_mergable(leaf, fi, new)) {
2581 btrfs_set_file_extent_num_bytes(leaf, fi,
2582 extent_len + len);
2583 btrfs_mark_buffer_dirty(leaf);
2584 inode_add_bytes(inode, len);
2585
2586 ret = 1;
2587 goto out_free_path;
2588 } else {
2589 merge = false;
2590 btrfs_release_path(path);
2591 goto again;
2592 }
2593 }
2594
2595 ret = btrfs_insert_empty_item(trans, root, path, &key,
2596 sizeof(*extent));
2597 if (ret) {
2598 btrfs_abort_transaction(trans, root, ret);
2599 goto out_free_path;
2600 }
2601
2602 leaf = path->nodes[0];
2603 item = btrfs_item_ptr(leaf, path->slots[0],
2604 struct btrfs_file_extent_item);
2605 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2606 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2607 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2608 btrfs_set_file_extent_num_bytes(leaf, item, len);
2609 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2610 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2611 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2612 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2613 btrfs_set_file_extent_encryption(leaf, item, 0);
2614 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2615
2616 btrfs_mark_buffer_dirty(leaf);
2617 inode_add_bytes(inode, len);
2618 btrfs_release_path(path);
2619
2620 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2621 new->disk_len, 0,
2622 backref->root_id, backref->inum,
2623 new->file_pos); /* start - extent_offset */
2624 if (ret) {
2625 btrfs_abort_transaction(trans, root, ret);
2626 goto out_free_path;
2627 }
2628
2629 ret = 1;
2630 out_free_path:
2631 btrfs_release_path(path);
2632 path->leave_spinning = 0;
2633 btrfs_end_transaction(trans, root);
2634 out_unlock:
2635 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2636 &cached, GFP_NOFS);
2637 iput(inode);
2638 return ret;
2639 }
2640
2641 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2642 {
2643 struct old_sa_defrag_extent *old, *tmp;
2644
2645 if (!new)
2646 return;
2647
2648 list_for_each_entry_safe(old, tmp, &new->head, list) {
2649 kfree(old);
2650 }
2651 kfree(new);
2652 }
2653
2654 static void relink_file_extents(struct new_sa_defrag_extent *new)
2655 {
2656 struct btrfs_path *path;
2657 struct sa_defrag_extent_backref *backref;
2658 struct sa_defrag_extent_backref *prev = NULL;
2659 struct inode *inode;
2660 struct btrfs_root *root;
2661 struct rb_node *node;
2662 int ret;
2663
2664 inode = new->inode;
2665 root = BTRFS_I(inode)->root;
2666
2667 path = btrfs_alloc_path();
2668 if (!path)
2669 return;
2670
2671 if (!record_extent_backrefs(path, new)) {
2672 btrfs_free_path(path);
2673 goto out;
2674 }
2675 btrfs_release_path(path);
2676
2677 while (1) {
2678 node = rb_first(&new->root);
2679 if (!node)
2680 break;
2681 rb_erase(node, &new->root);
2682
2683 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2684
2685 ret = relink_extent_backref(path, prev, backref);
2686 WARN_ON(ret < 0);
2687
2688 kfree(prev);
2689
2690 if (ret == 1)
2691 prev = backref;
2692 else
2693 prev = NULL;
2694 cond_resched();
2695 }
2696 kfree(prev);
2697
2698 btrfs_free_path(path);
2699 out:
2700 free_sa_defrag_extent(new);
2701
2702 atomic_dec(&root->fs_info->defrag_running);
2703 wake_up(&root->fs_info->transaction_wait);
2704 }
2705
2706 static struct new_sa_defrag_extent *
2707 record_old_file_extents(struct inode *inode,
2708 struct btrfs_ordered_extent *ordered)
2709 {
2710 struct btrfs_root *root = BTRFS_I(inode)->root;
2711 struct btrfs_path *path;
2712 struct btrfs_key key;
2713 struct old_sa_defrag_extent *old;
2714 struct new_sa_defrag_extent *new;
2715 int ret;
2716
2717 new = kmalloc(sizeof(*new), GFP_NOFS);
2718 if (!new)
2719 return NULL;
2720
2721 new->inode = inode;
2722 new->file_pos = ordered->file_offset;
2723 new->len = ordered->len;
2724 new->bytenr = ordered->start;
2725 new->disk_len = ordered->disk_len;
2726 new->compress_type = ordered->compress_type;
2727 new->root = RB_ROOT;
2728 INIT_LIST_HEAD(&new->head);
2729
2730 path = btrfs_alloc_path();
2731 if (!path)
2732 goto out_kfree;
2733
2734 key.objectid = btrfs_ino(inode);
2735 key.type = BTRFS_EXTENT_DATA_KEY;
2736 key.offset = new->file_pos;
2737
2738 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2739 if (ret < 0)
2740 goto out_free_path;
2741 if (ret > 0 && path->slots[0] > 0)
2742 path->slots[0]--;
2743
2744 /* find out all the old extents for the file range */
2745 while (1) {
2746 struct btrfs_file_extent_item *extent;
2747 struct extent_buffer *l;
2748 int slot;
2749 u64 num_bytes;
2750 u64 offset;
2751 u64 end;
2752 u64 disk_bytenr;
2753 u64 extent_offset;
2754
2755 l = path->nodes[0];
2756 slot = path->slots[0];
2757
2758 if (slot >= btrfs_header_nritems(l)) {
2759 ret = btrfs_next_leaf(root, path);
2760 if (ret < 0)
2761 goto out_free_path;
2762 else if (ret > 0)
2763 break;
2764 continue;
2765 }
2766
2767 btrfs_item_key_to_cpu(l, &key, slot);
2768
2769 if (key.objectid != btrfs_ino(inode))
2770 break;
2771 if (key.type != BTRFS_EXTENT_DATA_KEY)
2772 break;
2773 if (key.offset >= new->file_pos + new->len)
2774 break;
2775
2776 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2777
2778 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2779 if (key.offset + num_bytes < new->file_pos)
2780 goto next;
2781
2782 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2783 if (!disk_bytenr)
2784 goto next;
2785
2786 extent_offset = btrfs_file_extent_offset(l, extent);
2787
2788 old = kmalloc(sizeof(*old), GFP_NOFS);
2789 if (!old)
2790 goto out_free_path;
2791
2792 offset = max(new->file_pos, key.offset);
2793 end = min(new->file_pos + new->len, key.offset + num_bytes);
2794
2795 old->bytenr = disk_bytenr;
2796 old->extent_offset = extent_offset;
2797 old->offset = offset - key.offset;
2798 old->len = end - offset;
2799 old->new = new;
2800 old->count = 0;
2801 list_add_tail(&old->list, &new->head);
2802 next:
2803 path->slots[0]++;
2804 cond_resched();
2805 }
2806
2807 btrfs_free_path(path);
2808 atomic_inc(&root->fs_info->defrag_running);
2809
2810 return new;
2811
2812 out_free_path:
2813 btrfs_free_path(path);
2814 out_kfree:
2815 free_sa_defrag_extent(new);
2816 return NULL;
2817 }
2818
2819 static void btrfs_release_delalloc_bytes(struct btrfs_root *root,
2820 u64 start, u64 len)
2821 {
2822 struct btrfs_block_group_cache *cache;
2823
2824 cache = btrfs_lookup_block_group(root->fs_info, start);
2825 ASSERT(cache);
2826
2827 spin_lock(&cache->lock);
2828 cache->delalloc_bytes -= len;
2829 spin_unlock(&cache->lock);
2830
2831 btrfs_put_block_group(cache);
2832 }
2833
2834 /* as ordered data IO finishes, this gets called so we can finish
2835 * an ordered extent if the range of bytes in the file it covers are
2836 * fully written.
2837 */
2838 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2839 {
2840 struct inode *inode = ordered_extent->inode;
2841 struct btrfs_root *root = BTRFS_I(inode)->root;
2842 struct btrfs_trans_handle *trans = NULL;
2843 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2844 struct extent_state *cached_state = NULL;
2845 struct new_sa_defrag_extent *new = NULL;
2846 int compress_type = 0;
2847 int ret = 0;
2848 u64 logical_len = ordered_extent->len;
2849 bool nolock;
2850 bool truncated = false;
2851
2852 nolock = btrfs_is_free_space_inode(inode);
2853
2854 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2855 ret = -EIO;
2856 goto out;
2857 }
2858
2859 btrfs_free_io_failure_record(inode, ordered_extent->file_offset,
2860 ordered_extent->file_offset +
2861 ordered_extent->len - 1);
2862
2863 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2864 truncated = true;
2865 logical_len = ordered_extent->truncated_len;
2866 /* Truncated the entire extent, don't bother adding */
2867 if (!logical_len)
2868 goto out;
2869 }
2870
2871 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2872 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2873
2874 /*
2875 * For mwrite(mmap + memset to write) case, we still reserve
2876 * space for NOCOW range.
2877 * As NOCOW won't cause a new delayed ref, just free the space
2878 */
2879 btrfs_qgroup_free_data(inode, ordered_extent->file_offset,
2880 ordered_extent->len);
2881 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2882 if (nolock)
2883 trans = btrfs_join_transaction_nolock(root);
2884 else
2885 trans = btrfs_join_transaction(root);
2886 if (IS_ERR(trans)) {
2887 ret = PTR_ERR(trans);
2888 trans = NULL;
2889 goto out;
2890 }
2891 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2892 ret = btrfs_update_inode_fallback(trans, root, inode);
2893 if (ret) /* -ENOMEM or corruption */
2894 btrfs_abort_transaction(trans, root, ret);
2895 goto out;
2896 }
2897
2898 lock_extent_bits(io_tree, ordered_extent->file_offset,
2899 ordered_extent->file_offset + ordered_extent->len - 1,
2900 &cached_state);
2901
2902 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2903 ordered_extent->file_offset + ordered_extent->len - 1,
2904 EXTENT_DEFRAG, 1, cached_state);
2905 if (ret) {
2906 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2907 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
2908 /* the inode is shared */
2909 new = record_old_file_extents(inode, ordered_extent);
2910
2911 clear_extent_bit(io_tree, ordered_extent->file_offset,
2912 ordered_extent->file_offset + ordered_extent->len - 1,
2913 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2914 }
2915
2916 if (nolock)
2917 trans = btrfs_join_transaction_nolock(root);
2918 else
2919 trans = btrfs_join_transaction(root);
2920 if (IS_ERR(trans)) {
2921 ret = PTR_ERR(trans);
2922 trans = NULL;
2923 goto out_unlock;
2924 }
2925
2926 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2927
2928 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2929 compress_type = ordered_extent->compress_type;
2930 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2931 BUG_ON(compress_type);
2932 ret = btrfs_mark_extent_written(trans, inode,
2933 ordered_extent->file_offset,
2934 ordered_extent->file_offset +
2935 logical_len);
2936 } else {
2937 BUG_ON(root == root->fs_info->tree_root);
2938 ret = insert_reserved_file_extent(trans, inode,
2939 ordered_extent->file_offset,
2940 ordered_extent->start,
2941 ordered_extent->disk_len,
2942 logical_len, logical_len,
2943 compress_type, 0, 0,
2944 BTRFS_FILE_EXTENT_REG);
2945 if (!ret)
2946 btrfs_release_delalloc_bytes(root,
2947 ordered_extent->start,
2948 ordered_extent->disk_len);
2949 }
2950 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2951 ordered_extent->file_offset, ordered_extent->len,
2952 trans->transid);
2953 if (ret < 0) {
2954 btrfs_abort_transaction(trans, root, ret);
2955 goto out_unlock;
2956 }
2957
2958 add_pending_csums(trans, inode, ordered_extent->file_offset,
2959 &ordered_extent->list);
2960
2961 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2962 ret = btrfs_update_inode_fallback(trans, root, inode);
2963 if (ret) { /* -ENOMEM or corruption */
2964 btrfs_abort_transaction(trans, root, ret);
2965 goto out_unlock;
2966 }
2967 ret = 0;
2968 out_unlock:
2969 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2970 ordered_extent->file_offset +
2971 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2972 out:
2973 if (root != root->fs_info->tree_root)
2974 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2975 if (trans)
2976 btrfs_end_transaction(trans, root);
2977
2978 if (ret || truncated) {
2979 u64 start, end;
2980
2981 if (truncated)
2982 start = ordered_extent->file_offset + logical_len;
2983 else
2984 start = ordered_extent->file_offset;
2985 end = ordered_extent->file_offset + ordered_extent->len - 1;
2986 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
2987
2988 /* Drop the cache for the part of the extent we didn't write. */
2989 btrfs_drop_extent_cache(inode, start, end, 0);
2990
2991 /*
2992 * If the ordered extent had an IOERR or something else went
2993 * wrong we need to return the space for this ordered extent
2994 * back to the allocator. We only free the extent in the
2995 * truncated case if we didn't write out the extent at all.
2996 */
2997 if ((ret || !logical_len) &&
2998 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2999 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
3000 btrfs_free_reserved_extent(root, ordered_extent->start,
3001 ordered_extent->disk_len, 1);
3002 }
3003
3004
3005 /*
3006 * This needs to be done to make sure anybody waiting knows we are done
3007 * updating everything for this ordered extent.
3008 */
3009 btrfs_remove_ordered_extent(inode, ordered_extent);
3010
3011 /* for snapshot-aware defrag */
3012 if (new) {
3013 if (ret) {
3014 free_sa_defrag_extent(new);
3015 atomic_dec(&root->fs_info->defrag_running);
3016 } else {
3017 relink_file_extents(new);
3018 }
3019 }
3020
3021 /* once for us */
3022 btrfs_put_ordered_extent(ordered_extent);
3023 /* once for the tree */
3024 btrfs_put_ordered_extent(ordered_extent);
3025
3026 return ret;
3027 }
3028
3029 static void finish_ordered_fn(struct btrfs_work *work)
3030 {
3031 struct btrfs_ordered_extent *ordered_extent;
3032 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
3033 btrfs_finish_ordered_io(ordered_extent);
3034 }
3035
3036 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
3037 struct extent_state *state, int uptodate)
3038 {
3039 struct inode *inode = page->mapping->host;
3040 struct btrfs_root *root = BTRFS_I(inode)->root;
3041 struct btrfs_ordered_extent *ordered_extent = NULL;
3042 struct btrfs_workqueue *wq;
3043 btrfs_work_func_t func;
3044
3045 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
3046
3047 ClearPagePrivate2(page);
3048 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
3049 end - start + 1, uptodate))
3050 return 0;
3051
3052 if (btrfs_is_free_space_inode(inode)) {
3053 wq = root->fs_info->endio_freespace_worker;
3054 func = btrfs_freespace_write_helper;
3055 } else {
3056 wq = root->fs_info->endio_write_workers;
3057 func = btrfs_endio_write_helper;
3058 }
3059
3060 btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
3061 NULL);
3062 btrfs_queue_work(wq, &ordered_extent->work);
3063
3064 return 0;
3065 }
3066
3067 static int __readpage_endio_check(struct inode *inode,
3068 struct btrfs_io_bio *io_bio,
3069 int icsum, struct page *page,
3070 int pgoff, u64 start, size_t len)
3071 {
3072 char *kaddr;
3073 u32 csum_expected;
3074 u32 csum = ~(u32)0;
3075
3076 csum_expected = *(((u32 *)io_bio->csum) + icsum);
3077
3078 kaddr = kmap_atomic(page);
3079 csum = btrfs_csum_data(kaddr + pgoff, csum, len);
3080 btrfs_csum_final(csum, (char *)&csum);
3081 if (csum != csum_expected)
3082 goto zeroit;
3083
3084 kunmap_atomic(kaddr);
3085 return 0;
3086 zeroit:
3087 btrfs_warn_rl(BTRFS_I(inode)->root->fs_info,
3088 "csum failed ino %llu off %llu csum %u expected csum %u",
3089 btrfs_ino(inode), start, csum, csum_expected);
3090 memset(kaddr + pgoff, 1, len);
3091 flush_dcache_page(page);
3092 kunmap_atomic(kaddr);
3093 if (csum_expected == 0)
3094 return 0;
3095 return -EIO;
3096 }
3097
3098 /*
3099 * when reads are done, we need to check csums to verify the data is correct
3100 * if there's a match, we allow the bio to finish. If not, the code in
3101 * extent_io.c will try to find good copies for us.
3102 */
3103 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
3104 u64 phy_offset, struct page *page,
3105 u64 start, u64 end, int mirror)
3106 {
3107 size_t offset = start - page_offset(page);
3108 struct inode *inode = page->mapping->host;
3109 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3110 struct btrfs_root *root = BTRFS_I(inode)->root;
3111
3112 if (PageChecked(page)) {
3113 ClearPageChecked(page);
3114 return 0;
3115 }
3116
3117 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3118 return 0;
3119
3120 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
3121 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
3122 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM);
3123 return 0;
3124 }
3125
3126 phy_offset >>= inode->i_sb->s_blocksize_bits;
3127 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3128 start, (size_t)(end - start + 1));
3129 }
3130
3131 void btrfs_add_delayed_iput(struct inode *inode)
3132 {
3133 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
3134 struct btrfs_inode *binode = BTRFS_I(inode);
3135
3136 if (atomic_add_unless(&inode->i_count, -1, 1))
3137 return;
3138
3139 spin_lock(&fs_info->delayed_iput_lock);
3140 if (binode->delayed_iput_count == 0) {
3141 ASSERT(list_empty(&binode->delayed_iput));
3142 list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
3143 } else {
3144 binode->delayed_iput_count++;
3145 }
3146 spin_unlock(&fs_info->delayed_iput_lock);
3147 }
3148
3149 void btrfs_run_delayed_iputs(struct btrfs_root *root)
3150 {
3151 struct btrfs_fs_info *fs_info = root->fs_info;
3152
3153 spin_lock(&fs_info->delayed_iput_lock);
3154 while (!list_empty(&fs_info->delayed_iputs)) {
3155 struct btrfs_inode *inode;
3156
3157 inode = list_first_entry(&fs_info->delayed_iputs,
3158 struct btrfs_inode, delayed_iput);
3159 if (inode->delayed_iput_count) {
3160 inode->delayed_iput_count--;
3161 list_move_tail(&inode->delayed_iput,
3162 &fs_info->delayed_iputs);
3163 } else {
3164 list_del_init(&inode->delayed_iput);
3165 }
3166 spin_unlock(&fs_info->delayed_iput_lock);
3167 iput(&inode->vfs_inode);
3168 spin_lock(&fs_info->delayed_iput_lock);
3169 }
3170 spin_unlock(&fs_info->delayed_iput_lock);
3171 }
3172
3173 /*
3174 * This is called in transaction commit time. If there are no orphan
3175 * files in the subvolume, it removes orphan item and frees block_rsv
3176 * structure.
3177 */
3178 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
3179 struct btrfs_root *root)
3180 {
3181 struct btrfs_block_rsv *block_rsv;
3182 int ret;
3183
3184 if (atomic_read(&root->orphan_inodes) ||
3185 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
3186 return;
3187
3188 spin_lock(&root->orphan_lock);
3189 if (atomic_read(&root->orphan_inodes)) {
3190 spin_unlock(&root->orphan_lock);
3191 return;
3192 }
3193
3194 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
3195 spin_unlock(&root->orphan_lock);
3196 return;
3197 }
3198
3199 block_rsv = root->orphan_block_rsv;
3200 root->orphan_block_rsv = NULL;
3201 spin_unlock(&root->orphan_lock);
3202
3203 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
3204 btrfs_root_refs(&root->root_item) > 0) {
3205 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
3206 root->root_key.objectid);
3207 if (ret)
3208 btrfs_abort_transaction(trans, root, ret);
3209 else
3210 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
3211 &root->state);
3212 }
3213
3214 if (block_rsv) {
3215 WARN_ON(block_rsv->size > 0);
3216 btrfs_free_block_rsv(root, block_rsv);
3217 }
3218 }
3219
3220 /*
3221 * This creates an orphan entry for the given inode in case something goes
3222 * wrong in the middle of an unlink/truncate.
3223 *
3224 * NOTE: caller of this function should reserve 5 units of metadata for
3225 * this function.
3226 */
3227 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
3228 {
3229 struct btrfs_root *root = BTRFS_I(inode)->root;
3230 struct btrfs_block_rsv *block_rsv = NULL;
3231 int reserve = 0;
3232 int insert = 0;
3233 int ret;
3234
3235 if (!root->orphan_block_rsv) {
3236 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
3237 if (!block_rsv)
3238 return -ENOMEM;
3239 }
3240
3241 spin_lock(&root->orphan_lock);
3242 if (!root->orphan_block_rsv) {
3243 root->orphan_block_rsv = block_rsv;
3244 } else if (block_rsv) {
3245 btrfs_free_block_rsv(root, block_rsv);
3246 block_rsv = NULL;
3247 }
3248
3249 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3250 &BTRFS_I(inode)->runtime_flags)) {
3251 #if 0
3252 /*
3253 * For proper ENOSPC handling, we should do orphan
3254 * cleanup when mounting. But this introduces backward
3255 * compatibility issue.
3256 */
3257 if (!xchg(&root->orphan_item_inserted, 1))
3258 insert = 2;
3259 else
3260 insert = 1;
3261 #endif
3262 insert = 1;
3263 atomic_inc(&root->orphan_inodes);
3264 }
3265
3266 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3267 &BTRFS_I(inode)->runtime_flags))
3268 reserve = 1;
3269 spin_unlock(&root->orphan_lock);
3270
3271 /* grab metadata reservation from transaction handle */
3272 if (reserve) {
3273 ret = btrfs_orphan_reserve_metadata(trans, inode);
3274 ASSERT(!ret);
3275 if (ret) {
3276 atomic_dec(&root->orphan_inodes);
3277 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3278 &BTRFS_I(inode)->runtime_flags);
3279 if (insert)
3280 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3281 &BTRFS_I(inode)->runtime_flags);
3282 return ret;
3283 }
3284 }
3285
3286 /* insert an orphan item to track this unlinked/truncated file */
3287 if (insert >= 1) {
3288 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3289 if (ret) {
3290 atomic_dec(&root->orphan_inodes);
3291 if (reserve) {
3292 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3293 &BTRFS_I(inode)->runtime_flags);
3294 btrfs_orphan_release_metadata(inode);
3295 }
3296 if (ret != -EEXIST) {
3297 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3298 &BTRFS_I(inode)->runtime_flags);
3299 btrfs_abort_transaction(trans, root, ret);
3300 return ret;
3301 }
3302 }
3303 ret = 0;
3304 }
3305
3306 /* insert an orphan item to track subvolume contains orphan files */
3307 if (insert >= 2) {
3308 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
3309 root->root_key.objectid);
3310 if (ret && ret != -EEXIST) {
3311 btrfs_abort_transaction(trans, root, ret);
3312 return ret;
3313 }
3314 }
3315 return 0;
3316 }
3317
3318 /*
3319 * We have done the truncate/delete so we can go ahead and remove the orphan
3320 * item for this particular inode.
3321 */
3322 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3323 struct inode *inode)
3324 {
3325 struct btrfs_root *root = BTRFS_I(inode)->root;
3326 int delete_item = 0;
3327 int release_rsv = 0;
3328 int ret = 0;
3329
3330 spin_lock(&root->orphan_lock);
3331 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3332 &BTRFS_I(inode)->runtime_flags))
3333 delete_item = 1;
3334
3335 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3336 &BTRFS_I(inode)->runtime_flags))
3337 release_rsv = 1;
3338 spin_unlock(&root->orphan_lock);
3339
3340 if (delete_item) {
3341 atomic_dec(&root->orphan_inodes);
3342 if (trans)
3343 ret = btrfs_del_orphan_item(trans, root,
3344 btrfs_ino(inode));
3345 }
3346
3347 if (release_rsv)
3348 btrfs_orphan_release_metadata(inode);
3349
3350 return ret;
3351 }
3352
3353 /*
3354 * this cleans up any orphans that may be left on the list from the last use
3355 * of this root.
3356 */
3357 int btrfs_orphan_cleanup(struct btrfs_root *root)
3358 {
3359 struct btrfs_path *path;
3360 struct extent_buffer *leaf;
3361 struct btrfs_key key, found_key;
3362 struct btrfs_trans_handle *trans;
3363 struct inode *inode;
3364 u64 last_objectid = 0;
3365 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3366
3367 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3368 return 0;
3369
3370 path = btrfs_alloc_path();
3371 if (!path) {
3372 ret = -ENOMEM;
3373 goto out;
3374 }
3375 path->reada = READA_BACK;
3376
3377 key.objectid = BTRFS_ORPHAN_OBJECTID;
3378 key.type = BTRFS_ORPHAN_ITEM_KEY;
3379 key.offset = (u64)-1;
3380
3381 while (1) {
3382 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3383 if (ret < 0)
3384 goto out;
3385
3386 /*
3387 * if ret == 0 means we found what we were searching for, which
3388 * is weird, but possible, so only screw with path if we didn't
3389 * find the key and see if we have stuff that matches
3390 */
3391 if (ret > 0) {
3392 ret = 0;
3393 if (path->slots[0] == 0)
3394 break;
3395 path->slots[0]--;
3396 }
3397
3398 /* pull out the item */
3399 leaf = path->nodes[0];
3400 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3401
3402 /* make sure the item matches what we want */
3403 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3404 break;
3405 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3406 break;
3407
3408 /* release the path since we're done with it */
3409 btrfs_release_path(path);
3410
3411 /*
3412 * this is where we are basically btrfs_lookup, without the
3413 * crossing root thing. we store the inode number in the
3414 * offset of the orphan item.
3415 */
3416
3417 if (found_key.offset == last_objectid) {
3418 btrfs_err(root->fs_info,
3419 "Error removing orphan entry, stopping orphan cleanup");
3420 ret = -EINVAL;
3421 goto out;
3422 }
3423
3424 last_objectid = found_key.offset;
3425
3426 found_key.objectid = found_key.offset;
3427 found_key.type = BTRFS_INODE_ITEM_KEY;
3428 found_key.offset = 0;
3429 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3430 ret = PTR_ERR_OR_ZERO(inode);
3431 if (ret && ret != -ESTALE)
3432 goto out;
3433
3434 if (ret == -ESTALE && root == root->fs_info->tree_root) {
3435 struct btrfs_root *dead_root;
3436 struct btrfs_fs_info *fs_info = root->fs_info;
3437 int is_dead_root = 0;
3438
3439 /*
3440 * this is an orphan in the tree root. Currently these
3441 * could come from 2 sources:
3442 * a) a snapshot deletion in progress
3443 * b) a free space cache inode
3444 * We need to distinguish those two, as the snapshot
3445 * orphan must not get deleted.
3446 * find_dead_roots already ran before us, so if this
3447 * is a snapshot deletion, we should find the root
3448 * in the dead_roots list
3449 */
3450 spin_lock(&fs_info->trans_lock);
3451 list_for_each_entry(dead_root, &fs_info->dead_roots,
3452 root_list) {
3453 if (dead_root->root_key.objectid ==
3454 found_key.objectid) {
3455 is_dead_root = 1;
3456 break;
3457 }
3458 }
3459 spin_unlock(&fs_info->trans_lock);
3460 if (is_dead_root) {
3461 /* prevent this orphan from being found again */
3462 key.offset = found_key.objectid - 1;
3463 continue;
3464 }
3465 }
3466 /*
3467 * Inode is already gone but the orphan item is still there,
3468 * kill the orphan item.
3469 */
3470 if (ret == -ESTALE) {
3471 trans = btrfs_start_transaction(root, 1);
3472 if (IS_ERR(trans)) {
3473 ret = PTR_ERR(trans);
3474 goto out;
3475 }
3476 btrfs_debug(root->fs_info, "auto deleting %Lu",
3477 found_key.objectid);
3478 ret = btrfs_del_orphan_item(trans, root,
3479 found_key.objectid);
3480 btrfs_end_transaction(trans, root);
3481 if (ret)
3482 goto out;
3483 continue;
3484 }
3485
3486 /*
3487 * add this inode to the orphan list so btrfs_orphan_del does
3488 * the proper thing when we hit it
3489 */
3490 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3491 &BTRFS_I(inode)->runtime_flags);
3492 atomic_inc(&root->orphan_inodes);
3493
3494 /* if we have links, this was a truncate, lets do that */
3495 if (inode->i_nlink) {
3496 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3497 iput(inode);
3498 continue;
3499 }
3500 nr_truncate++;
3501
3502 /* 1 for the orphan item deletion. */
3503 trans = btrfs_start_transaction(root, 1);
3504 if (IS_ERR(trans)) {
3505 iput(inode);
3506 ret = PTR_ERR(trans);
3507 goto out;
3508 }
3509 ret = btrfs_orphan_add(trans, inode);
3510 btrfs_end_transaction(trans, root);
3511 if (ret) {
3512 iput(inode);
3513 goto out;
3514 }
3515
3516 ret = btrfs_truncate(inode);
3517 if (ret)
3518 btrfs_orphan_del(NULL, inode);
3519 } else {
3520 nr_unlink++;
3521 }
3522
3523 /* this will do delete_inode and everything for us */
3524 iput(inode);
3525 if (ret)
3526 goto out;
3527 }
3528 /* release the path since we're done with it */
3529 btrfs_release_path(path);
3530
3531 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3532
3533 if (root->orphan_block_rsv)
3534 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3535 (u64)-1);
3536
3537 if (root->orphan_block_rsv ||
3538 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3539 trans = btrfs_join_transaction(root);
3540 if (!IS_ERR(trans))
3541 btrfs_end_transaction(trans, root);
3542 }
3543
3544 if (nr_unlink)
3545 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3546 if (nr_truncate)
3547 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3548
3549 out:
3550 if (ret)
3551 btrfs_err(root->fs_info,
3552 "could not do orphan cleanup %d", ret);
3553 btrfs_free_path(path);
3554 return ret;
3555 }
3556
3557 /*
3558 * very simple check to peek ahead in the leaf looking for xattrs. If we
3559 * don't find any xattrs, we know there can't be any acls.
3560 *
3561 * slot is the slot the inode is in, objectid is the objectid of the inode
3562 */
3563 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3564 int slot, u64 objectid,
3565 int *first_xattr_slot)
3566 {
3567 u32 nritems = btrfs_header_nritems(leaf);
3568 struct btrfs_key found_key;
3569 static u64 xattr_access = 0;
3570 static u64 xattr_default = 0;
3571 int scanned = 0;
3572
3573 if (!xattr_access) {
3574 xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
3575 strlen(XATTR_NAME_POSIX_ACL_ACCESS));
3576 xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
3577 strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
3578 }
3579
3580 slot++;
3581 *first_xattr_slot = -1;
3582 while (slot < nritems) {
3583 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3584
3585 /* we found a different objectid, there must not be acls */
3586 if (found_key.objectid != objectid)
3587 return 0;
3588
3589 /* we found an xattr, assume we've got an acl */
3590 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3591 if (*first_xattr_slot == -1)
3592 *first_xattr_slot = slot;
3593 if (found_key.offset == xattr_access ||
3594 found_key.offset == xattr_default)
3595 return 1;
3596 }
3597
3598 /*
3599 * we found a key greater than an xattr key, there can't
3600 * be any acls later on
3601 */
3602 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3603 return 0;
3604
3605 slot++;
3606 scanned++;
3607
3608 /*
3609 * it goes inode, inode backrefs, xattrs, extents,
3610 * so if there are a ton of hard links to an inode there can
3611 * be a lot of backrefs. Don't waste time searching too hard,
3612 * this is just an optimization
3613 */
3614 if (scanned >= 8)
3615 break;
3616 }
3617 /* we hit the end of the leaf before we found an xattr or
3618 * something larger than an xattr. We have to assume the inode
3619 * has acls
3620 */
3621 if (*first_xattr_slot == -1)
3622 *first_xattr_slot = slot;
3623 return 1;
3624 }
3625
3626 /*
3627 * read an inode from the btree into the in-memory inode
3628 */
3629 static void btrfs_read_locked_inode(struct inode *inode)
3630 {
3631 struct btrfs_path *path;
3632 struct extent_buffer *leaf;
3633 struct btrfs_inode_item *inode_item;
3634 struct btrfs_root *root = BTRFS_I(inode)->root;
3635 struct btrfs_key location;
3636 unsigned long ptr;
3637 int maybe_acls;
3638 u32 rdev;
3639 int ret;
3640 bool filled = false;
3641 int first_xattr_slot;
3642
3643 ret = btrfs_fill_inode(inode, &rdev);
3644 if (!ret)
3645 filled = true;
3646
3647 path = btrfs_alloc_path();
3648 if (!path)
3649 goto make_bad;
3650
3651 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3652
3653 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3654 if (ret)
3655 goto make_bad;
3656
3657 leaf = path->nodes[0];
3658
3659 if (filled)
3660 goto cache_index;
3661
3662 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3663 struct btrfs_inode_item);
3664 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3665 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3666 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3667 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3668 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3669
3670 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3671 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3672
3673 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3674 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3675
3676 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3677 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3678
3679 BTRFS_I(inode)->i_otime.tv_sec =
3680 btrfs_timespec_sec(leaf, &inode_item->otime);
3681 BTRFS_I(inode)->i_otime.tv_nsec =
3682 btrfs_timespec_nsec(leaf, &inode_item->otime);
3683
3684 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3685 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3686 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3687
3688 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3689 inode->i_generation = BTRFS_I(inode)->generation;
3690 inode->i_rdev = 0;
3691 rdev = btrfs_inode_rdev(leaf, inode_item);
3692
3693 BTRFS_I(inode)->index_cnt = (u64)-1;
3694 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3695
3696 cache_index:
3697 /*
3698 * If we were modified in the current generation and evicted from memory
3699 * and then re-read we need to do a full sync since we don't have any
3700 * idea about which extents were modified before we were evicted from
3701 * cache.
3702 *
3703 * This is required for both inode re-read from disk and delayed inode
3704 * in delayed_nodes_tree.
3705 */
3706 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3707 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3708 &BTRFS_I(inode)->runtime_flags);
3709
3710 /*
3711 * We don't persist the id of the transaction where an unlink operation
3712 * against the inode was last made. So here we assume the inode might
3713 * have been evicted, and therefore the exact value of last_unlink_trans
3714 * lost, and set it to last_trans to avoid metadata inconsistencies
3715 * between the inode and its parent if the inode is fsync'ed and the log
3716 * replayed. For example, in the scenario:
3717 *
3718 * touch mydir/foo
3719 * ln mydir/foo mydir/bar
3720 * sync
3721 * unlink mydir/bar
3722 * echo 2 > /proc/sys/vm/drop_caches # evicts inode
3723 * xfs_io -c fsync mydir/foo
3724 * <power failure>
3725 * mount fs, triggers fsync log replay
3726 *
3727 * We must make sure that when we fsync our inode foo we also log its
3728 * parent inode, otherwise after log replay the parent still has the
3729 * dentry with the "bar" name but our inode foo has a link count of 1
3730 * and doesn't have an inode ref with the name "bar" anymore.
3731 *
3732 * Setting last_unlink_trans to last_trans is a pessimistic approach,
3733 * but it guarantees correctness at the expense of occasional full
3734 * transaction commits on fsync if our inode is a directory, or if our
3735 * inode is not a directory, logging its parent unnecessarily.
3736 */
3737 BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
3738
3739 path->slots[0]++;
3740 if (inode->i_nlink != 1 ||
3741 path->slots[0] >= btrfs_header_nritems(leaf))
3742 goto cache_acl;
3743
3744 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3745 if (location.objectid != btrfs_ino(inode))
3746 goto cache_acl;
3747
3748 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3749 if (location.type == BTRFS_INODE_REF_KEY) {
3750 struct btrfs_inode_ref *ref;
3751
3752 ref = (struct btrfs_inode_ref *)ptr;
3753 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3754 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3755 struct btrfs_inode_extref *extref;
3756
3757 extref = (struct btrfs_inode_extref *)ptr;
3758 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3759 extref);
3760 }
3761 cache_acl:
3762 /*
3763 * try to precache a NULL acl entry for files that don't have
3764 * any xattrs or acls
3765 */
3766 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3767 btrfs_ino(inode), &first_xattr_slot);
3768 if (first_xattr_slot != -1) {
3769 path->slots[0] = first_xattr_slot;
3770 ret = btrfs_load_inode_props(inode, path);
3771 if (ret)
3772 btrfs_err(root->fs_info,
3773 "error loading props for ino %llu (root %llu): %d",
3774 btrfs_ino(inode),
3775 root->root_key.objectid, ret);
3776 }
3777 btrfs_free_path(path);
3778
3779 if (!maybe_acls)
3780 cache_no_acl(inode);
3781
3782 switch (inode->i_mode & S_IFMT) {
3783 case S_IFREG:
3784 inode->i_mapping->a_ops = &btrfs_aops;
3785 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3786 inode->i_fop = &btrfs_file_operations;
3787 inode->i_op = &btrfs_file_inode_operations;
3788 break;
3789 case S_IFDIR:
3790 inode->i_fop = &btrfs_dir_file_operations;
3791 if (root == root->fs_info->tree_root)
3792 inode->i_op = &btrfs_dir_ro_inode_operations;
3793 else
3794 inode->i_op = &btrfs_dir_inode_operations;
3795 break;
3796 case S_IFLNK:
3797 inode->i_op = &btrfs_symlink_inode_operations;
3798 inode_nohighmem(inode);
3799 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3800 break;
3801 default:
3802 inode->i_op = &btrfs_special_inode_operations;
3803 init_special_inode(inode, inode->i_mode, rdev);
3804 break;
3805 }
3806
3807 btrfs_update_iflags(inode);
3808 return;
3809
3810 make_bad:
3811 btrfs_free_path(path);
3812 make_bad_inode(inode);
3813 }
3814
3815 /*
3816 * given a leaf and an inode, copy the inode fields into the leaf
3817 */
3818 static void fill_inode_item(struct btrfs_trans_handle *trans,
3819 struct extent_buffer *leaf,
3820 struct btrfs_inode_item *item,
3821 struct inode *inode)
3822 {
3823 struct btrfs_map_token token;
3824
3825 btrfs_init_map_token(&token);
3826
3827 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3828 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3829 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3830 &token);
3831 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3832 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3833
3834 btrfs_set_token_timespec_sec(leaf, &item->atime,
3835 inode->i_atime.tv_sec, &token);
3836 btrfs_set_token_timespec_nsec(leaf, &item->atime,
3837 inode->i_atime.tv_nsec, &token);
3838
3839 btrfs_set_token_timespec_sec(leaf, &item->mtime,
3840 inode->i_mtime.tv_sec, &token);
3841 btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3842 inode->i_mtime.tv_nsec, &token);
3843
3844 btrfs_set_token_timespec_sec(leaf, &item->ctime,
3845 inode->i_ctime.tv_sec, &token);
3846 btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3847 inode->i_ctime.tv_nsec, &token);
3848
3849 btrfs_set_token_timespec_sec(leaf, &item->otime,
3850 BTRFS_I(inode)->i_otime.tv_sec, &token);
3851 btrfs_set_token_timespec_nsec(leaf, &item->otime,
3852 BTRFS_I(inode)->i_otime.tv_nsec, &token);
3853
3854 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3855 &token);
3856 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3857 &token);
3858 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3859 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3860 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3861 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3862 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3863 }
3864
3865 /*
3866 * copy everything in the in-memory inode into the btree.
3867 */
3868 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3869 struct btrfs_root *root, struct inode *inode)
3870 {
3871 struct btrfs_inode_item *inode_item;
3872 struct btrfs_path *path;
3873 struct extent_buffer *leaf;
3874 int ret;
3875
3876 path = btrfs_alloc_path();
3877 if (!path)
3878 return -ENOMEM;
3879
3880 path->leave_spinning = 1;
3881 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3882 1);
3883 if (ret) {
3884 if (ret > 0)
3885 ret = -ENOENT;
3886 goto failed;
3887 }
3888
3889 leaf = path->nodes[0];
3890 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3891 struct btrfs_inode_item);
3892
3893 fill_inode_item(trans, leaf, inode_item, inode);
3894 btrfs_mark_buffer_dirty(leaf);
3895 btrfs_set_inode_last_trans(trans, inode);
3896 ret = 0;
3897 failed:
3898 btrfs_free_path(path);
3899 return ret;
3900 }
3901
3902 /*
3903 * copy everything in the in-memory inode into the btree.
3904 */
3905 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3906 struct btrfs_root *root, struct inode *inode)
3907 {
3908 int ret;
3909
3910 /*
3911 * If the inode is a free space inode, we can deadlock during commit
3912 * if we put it into the delayed code.
3913 *
3914 * The data relocation inode should also be directly updated
3915 * without delay
3916 */
3917 if (!btrfs_is_free_space_inode(inode)
3918 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
3919 && !root->fs_info->log_root_recovering) {
3920 btrfs_update_root_times(trans, root);
3921
3922 ret = btrfs_delayed_update_inode(trans, root, inode);
3923 if (!ret)
3924 btrfs_set_inode_last_trans(trans, inode);
3925 return ret;
3926 }
3927
3928 return btrfs_update_inode_item(trans, root, inode);
3929 }
3930
3931 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3932 struct btrfs_root *root,
3933 struct inode *inode)
3934 {
3935 int ret;
3936
3937 ret = btrfs_update_inode(trans, root, inode);
3938 if (ret == -ENOSPC)
3939 return btrfs_update_inode_item(trans, root, inode);
3940 return ret;
3941 }
3942
3943 /*
3944 * unlink helper that gets used here in inode.c and in the tree logging
3945 * recovery code. It remove a link in a directory with a given name, and
3946 * also drops the back refs in the inode to the directory
3947 */
3948 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3949 struct btrfs_root *root,
3950 struct inode *dir, struct inode *inode,
3951 const char *name, int name_len)
3952 {
3953 struct btrfs_path *path;
3954 int ret = 0;
3955 struct extent_buffer *leaf;
3956 struct btrfs_dir_item *di;
3957 struct btrfs_key key;
3958 u64 index;
3959 u64 ino = btrfs_ino(inode);
3960 u64 dir_ino = btrfs_ino(dir);
3961
3962 path = btrfs_alloc_path();
3963 if (!path) {
3964 ret = -ENOMEM;
3965 goto out;
3966 }
3967
3968 path->leave_spinning = 1;
3969 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3970 name, name_len, -1);
3971 if (IS_ERR(di)) {
3972 ret = PTR_ERR(di);
3973 goto err;
3974 }
3975 if (!di) {
3976 ret = -ENOENT;
3977 goto err;
3978 }
3979 leaf = path->nodes[0];
3980 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3981 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3982 if (ret)
3983 goto err;
3984 btrfs_release_path(path);
3985
3986 /*
3987 * If we don't have dir index, we have to get it by looking up
3988 * the inode ref, since we get the inode ref, remove it directly,
3989 * it is unnecessary to do delayed deletion.
3990 *
3991 * But if we have dir index, needn't search inode ref to get it.
3992 * Since the inode ref is close to the inode item, it is better
3993 * that we delay to delete it, and just do this deletion when
3994 * we update the inode item.
3995 */
3996 if (BTRFS_I(inode)->dir_index) {
3997 ret = btrfs_delayed_delete_inode_ref(inode);
3998 if (!ret) {
3999 index = BTRFS_I(inode)->dir_index;
4000 goto skip_backref;
4001 }
4002 }
4003
4004 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
4005 dir_ino, &index);
4006 if (ret) {
4007 btrfs_info(root->fs_info,
4008 "failed to delete reference to %.*s, inode %llu parent %llu",
4009 name_len, name, ino, dir_ino);
4010 btrfs_abort_transaction(trans, root, ret);
4011 goto err;
4012 }
4013 skip_backref:
4014 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
4015 if (ret) {
4016 btrfs_abort_transaction(trans, root, ret);
4017 goto err;
4018 }
4019
4020 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
4021 inode, dir_ino);
4022 if (ret != 0 && ret != -ENOENT) {
4023 btrfs_abort_transaction(trans, root, ret);
4024 goto err;
4025 }
4026
4027 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
4028 dir, index);
4029 if (ret == -ENOENT)
4030 ret = 0;
4031 else if (ret)
4032 btrfs_abort_transaction(trans, root, ret);
4033 err:
4034 btrfs_free_path(path);
4035 if (ret)
4036 goto out;
4037
4038 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4039 inode_inc_iversion(inode);
4040 inode_inc_iversion(dir);
4041 inode->i_ctime = dir->i_mtime =
4042 dir->i_ctime = current_fs_time(inode->i_sb);
4043 ret = btrfs_update_inode(trans, root, dir);
4044 out:
4045 return ret;
4046 }
4047
4048 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4049 struct btrfs_root *root,
4050 struct inode *dir, struct inode *inode,
4051 const char *name, int name_len)
4052 {
4053 int ret;
4054 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
4055 if (!ret) {
4056 drop_nlink(inode);
4057 ret = btrfs_update_inode(trans, root, inode);
4058 }
4059 return ret;
4060 }
4061
4062 /*
4063 * helper to start transaction for unlink and rmdir.
4064 *
4065 * unlink and rmdir are special in btrfs, they do not always free space, so
4066 * if we cannot make our reservations the normal way try and see if there is
4067 * plenty of slack room in the global reserve to migrate, otherwise we cannot
4068 * allow the unlink to occur.
4069 */
4070 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
4071 {
4072 struct btrfs_root *root = BTRFS_I(dir)->root;
4073
4074 /*
4075 * 1 for the possible orphan item
4076 * 1 for the dir item
4077 * 1 for the dir index
4078 * 1 for the inode ref
4079 * 1 for the inode
4080 */
4081 return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
4082 }
4083
4084 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4085 {
4086 struct btrfs_root *root = BTRFS_I(dir)->root;
4087 struct btrfs_trans_handle *trans;
4088 struct inode *inode = d_inode(dentry);
4089 int ret;
4090
4091 trans = __unlink_start_trans(dir);
4092 if (IS_ERR(trans))
4093 return PTR_ERR(trans);
4094
4095 btrfs_record_unlink_dir(trans, dir, d_inode(dentry), 0);
4096
4097 ret = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4098 dentry->d_name.name, dentry->d_name.len);
4099 if (ret)
4100 goto out;
4101
4102 if (inode->i_nlink == 0) {
4103 ret = btrfs_orphan_add(trans, inode);
4104 if (ret)
4105 goto out;
4106 }
4107
4108 out:
4109 btrfs_end_transaction(trans, root);
4110 btrfs_btree_balance_dirty(root);
4111 return ret;
4112 }
4113
4114 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4115 struct btrfs_root *root,
4116 struct inode *dir, u64 objectid,
4117 const char *name, int name_len)
4118 {
4119 struct btrfs_path *path;
4120 struct extent_buffer *leaf;
4121 struct btrfs_dir_item *di;
4122 struct btrfs_key key;
4123 u64 index;
4124 int ret;
4125 u64 dir_ino = btrfs_ino(dir);
4126
4127 path = btrfs_alloc_path();
4128 if (!path)
4129 return -ENOMEM;
4130
4131 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4132 name, name_len, -1);
4133 if (IS_ERR_OR_NULL(di)) {
4134 if (!di)
4135 ret = -ENOENT;
4136 else
4137 ret = PTR_ERR(di);
4138 goto out;
4139 }
4140
4141 leaf = path->nodes[0];
4142 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4143 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4144 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4145 if (ret) {
4146 btrfs_abort_transaction(trans, root, ret);
4147 goto out;
4148 }
4149 btrfs_release_path(path);
4150
4151 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
4152 objectid, root->root_key.objectid,
4153 dir_ino, &index, name, name_len);
4154 if (ret < 0) {
4155 if (ret != -ENOENT) {
4156 btrfs_abort_transaction(trans, root, ret);
4157 goto out;
4158 }
4159 di = btrfs_search_dir_index_item(root, path, dir_ino,
4160 name, name_len);
4161 if (IS_ERR_OR_NULL(di)) {
4162 if (!di)
4163 ret = -ENOENT;
4164 else
4165 ret = PTR_ERR(di);
4166 btrfs_abort_transaction(trans, root, ret);
4167 goto out;
4168 }
4169
4170 leaf = path->nodes[0];
4171 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4172 btrfs_release_path(path);
4173 index = key.offset;
4174 }
4175 btrfs_release_path(path);
4176
4177 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
4178 if (ret) {
4179 btrfs_abort_transaction(trans, root, ret);
4180 goto out;
4181 }
4182
4183 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4184 inode_inc_iversion(dir);
4185 dir->i_mtime = dir->i_ctime = current_fs_time(dir->i_sb);
4186 ret = btrfs_update_inode_fallback(trans, root, dir);
4187 if (ret)
4188 btrfs_abort_transaction(trans, root, ret);
4189 out:
4190 btrfs_free_path(path);
4191 return ret;
4192 }
4193
4194 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4195 {
4196 struct inode *inode = d_inode(dentry);
4197 int err = 0;
4198 struct btrfs_root *root = BTRFS_I(dir)->root;
4199 struct btrfs_trans_handle *trans;
4200
4201 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4202 return -ENOTEMPTY;
4203 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
4204 return -EPERM;
4205
4206 trans = __unlink_start_trans(dir);
4207 if (IS_ERR(trans))
4208 return PTR_ERR(trans);
4209
4210 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4211 err = btrfs_unlink_subvol(trans, root, dir,
4212 BTRFS_I(inode)->location.objectid,
4213 dentry->d_name.name,
4214 dentry->d_name.len);
4215 goto out;
4216 }
4217
4218 err = btrfs_orphan_add(trans, inode);
4219 if (err)
4220 goto out;
4221
4222 /* now the directory is empty */
4223 err = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4224 dentry->d_name.name, dentry->d_name.len);
4225 if (!err)
4226 btrfs_i_size_write(inode, 0);
4227 out:
4228 btrfs_end_transaction(trans, root);
4229 btrfs_btree_balance_dirty(root);
4230
4231 return err;
4232 }
4233
4234 static int truncate_space_check(struct btrfs_trans_handle *trans,
4235 struct btrfs_root *root,
4236 u64 bytes_deleted)
4237 {
4238 int ret;
4239
4240 /*
4241 * This is only used to apply pressure to the enospc system, we don't
4242 * intend to use this reservation at all.
4243 */
4244 bytes_deleted = btrfs_csum_bytes_to_leaves(root, bytes_deleted);
4245 bytes_deleted *= root->nodesize;
4246 ret = btrfs_block_rsv_add(root, &root->fs_info->trans_block_rsv,
4247 bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
4248 if (!ret) {
4249 trace_btrfs_space_reservation(root->fs_info, "transaction",
4250 trans->transid,
4251 bytes_deleted, 1);
4252 trans->bytes_reserved += bytes_deleted;
4253 }
4254 return ret;
4255
4256 }
4257
4258 static int truncate_inline_extent(struct inode *inode,
4259 struct btrfs_path *path,
4260 struct btrfs_key *found_key,
4261 const u64 item_end,
4262 const u64 new_size)
4263 {
4264 struct extent_buffer *leaf = path->nodes[0];
4265 int slot = path->slots[0];
4266 struct btrfs_file_extent_item *fi;
4267 u32 size = (u32)(new_size - found_key->offset);
4268 struct btrfs_root *root = BTRFS_I(inode)->root;
4269
4270 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
4271
4272 if (btrfs_file_extent_compression(leaf, fi) != BTRFS_COMPRESS_NONE) {
4273 loff_t offset = new_size;
4274 loff_t page_end = ALIGN(offset, PAGE_SIZE);
4275
4276 /*
4277 * Zero out the remaining of the last page of our inline extent,
4278 * instead of directly truncating our inline extent here - that
4279 * would be much more complex (decompressing all the data, then
4280 * compressing the truncated data, which might be bigger than
4281 * the size of the inline extent, resize the extent, etc).
4282 * We release the path because to get the page we might need to
4283 * read the extent item from disk (data not in the page cache).
4284 */
4285 btrfs_release_path(path);
4286 return btrfs_truncate_block(inode, offset, page_end - offset,
4287 0);
4288 }
4289
4290 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4291 size = btrfs_file_extent_calc_inline_size(size);
4292 btrfs_truncate_item(root, path, size, 1);
4293
4294 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4295 inode_sub_bytes(inode, item_end + 1 - new_size);
4296
4297 return 0;
4298 }
4299
4300 /*
4301 * this can truncate away extent items, csum items and directory items.
4302 * It starts at a high offset and removes keys until it can't find
4303 * any higher than new_size
4304 *
4305 * csum items that cross the new i_size are truncated to the new size
4306 * as well.
4307 *
4308 * min_type is the minimum key type to truncate down to. If set to 0, this
4309 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4310 */
4311 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4312 struct btrfs_root *root,
4313 struct inode *inode,
4314 u64 new_size, u32 min_type)
4315 {
4316 struct btrfs_path *path;
4317 struct extent_buffer *leaf;
4318 struct btrfs_file_extent_item *fi;
4319 struct btrfs_key key;
4320 struct btrfs_key found_key;
4321 u64 extent_start = 0;
4322 u64 extent_num_bytes = 0;
4323 u64 extent_offset = 0;
4324 u64 item_end = 0;
4325 u64 last_size = new_size;
4326 u32 found_type = (u8)-1;
4327 int found_extent;
4328 int del_item;
4329 int pending_del_nr = 0;
4330 int pending_del_slot = 0;
4331 int extent_type = -1;
4332 int ret;
4333 int err = 0;
4334 u64 ino = btrfs_ino(inode);
4335 u64 bytes_deleted = 0;
4336 bool be_nice = 0;
4337 bool should_throttle = 0;
4338 bool should_end = 0;
4339
4340 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4341
4342 /*
4343 * for non-free space inodes and ref cows, we want to back off from
4344 * time to time
4345 */
4346 if (!btrfs_is_free_space_inode(inode) &&
4347 test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4348 be_nice = 1;
4349
4350 path = btrfs_alloc_path();
4351 if (!path)
4352 return -ENOMEM;
4353 path->reada = READA_BACK;
4354
4355 /*
4356 * We want to drop from the next block forward in case this new size is
4357 * not block aligned since we will be keeping the last block of the
4358 * extent just the way it is.
4359 */
4360 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4361 root == root->fs_info->tree_root)
4362 btrfs_drop_extent_cache(inode, ALIGN(new_size,
4363 root->sectorsize), (u64)-1, 0);
4364
4365 /*
4366 * This function is also used to drop the items in the log tree before
4367 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4368 * it is used to drop the loged items. So we shouldn't kill the delayed
4369 * items.
4370 */
4371 if (min_type == 0 && root == BTRFS_I(inode)->root)
4372 btrfs_kill_delayed_inode_items(inode);
4373
4374 key.objectid = ino;
4375 key.offset = (u64)-1;
4376 key.type = (u8)-1;
4377
4378 search_again:
4379 /*
4380 * with a 16K leaf size and 128MB extents, you can actually queue
4381 * up a huge file in a single leaf. Most of the time that
4382 * bytes_deleted is > 0, it will be huge by the time we get here
4383 */
4384 if (be_nice && bytes_deleted > SZ_32M) {
4385 if (btrfs_should_end_transaction(trans, root)) {
4386 err = -EAGAIN;
4387 goto error;
4388 }
4389 }
4390
4391
4392 path->leave_spinning = 1;
4393 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4394 if (ret < 0) {
4395 err = ret;
4396 goto out;
4397 }
4398
4399 if (ret > 0) {
4400 /* there are no items in the tree for us to truncate, we're
4401 * done
4402 */
4403 if (path->slots[0] == 0)
4404 goto out;
4405 path->slots[0]--;
4406 }
4407
4408 while (1) {
4409 fi = NULL;
4410 leaf = path->nodes[0];
4411 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4412 found_type = found_key.type;
4413
4414 if (found_key.objectid != ino)
4415 break;
4416
4417 if (found_type < min_type)
4418 break;
4419
4420 item_end = found_key.offset;
4421 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4422 fi = btrfs_item_ptr(leaf, path->slots[0],
4423 struct btrfs_file_extent_item);
4424 extent_type = btrfs_file_extent_type(leaf, fi);
4425 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4426 item_end +=
4427 btrfs_file_extent_num_bytes(leaf, fi);
4428 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4429 item_end += btrfs_file_extent_inline_len(leaf,
4430 path->slots[0], fi);
4431 }
4432 item_end--;
4433 }
4434 if (found_type > min_type) {
4435 del_item = 1;
4436 } else {
4437 if (item_end < new_size)
4438 break;
4439 if (found_key.offset >= new_size)
4440 del_item = 1;
4441 else
4442 del_item = 0;
4443 }
4444 found_extent = 0;
4445 /* FIXME, shrink the extent if the ref count is only 1 */
4446 if (found_type != BTRFS_EXTENT_DATA_KEY)
4447 goto delete;
4448
4449 if (del_item)
4450 last_size = found_key.offset;
4451 else
4452 last_size = new_size;
4453
4454 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4455 u64 num_dec;
4456 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4457 if (!del_item) {
4458 u64 orig_num_bytes =
4459 btrfs_file_extent_num_bytes(leaf, fi);
4460 extent_num_bytes = ALIGN(new_size -
4461 found_key.offset,
4462 root->sectorsize);
4463 btrfs_set_file_extent_num_bytes(leaf, fi,
4464 extent_num_bytes);
4465 num_dec = (orig_num_bytes -
4466 extent_num_bytes);
4467 if (test_bit(BTRFS_ROOT_REF_COWS,
4468 &root->state) &&
4469 extent_start != 0)
4470 inode_sub_bytes(inode, num_dec);
4471 btrfs_mark_buffer_dirty(leaf);
4472 } else {
4473 extent_num_bytes =
4474 btrfs_file_extent_disk_num_bytes(leaf,
4475 fi);
4476 extent_offset = found_key.offset -
4477 btrfs_file_extent_offset(leaf, fi);
4478
4479 /* FIXME blocksize != 4096 */
4480 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4481 if (extent_start != 0) {
4482 found_extent = 1;
4483 if (test_bit(BTRFS_ROOT_REF_COWS,
4484 &root->state))
4485 inode_sub_bytes(inode, num_dec);
4486 }
4487 }
4488 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4489 /*
4490 * we can't truncate inline items that have had
4491 * special encodings
4492 */
4493 if (!del_item &&
4494 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4495 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4496
4497 /*
4498 * Need to release path in order to truncate a
4499 * compressed extent. So delete any accumulated
4500 * extent items so far.
4501 */
4502 if (btrfs_file_extent_compression(leaf, fi) !=
4503 BTRFS_COMPRESS_NONE && pending_del_nr) {
4504 err = btrfs_del_items(trans, root, path,
4505 pending_del_slot,
4506 pending_del_nr);
4507 if (err) {
4508 btrfs_abort_transaction(trans,
4509 root,
4510 err);
4511 goto error;
4512 }
4513 pending_del_nr = 0;
4514 }
4515
4516 err = truncate_inline_extent(inode, path,
4517 &found_key,
4518 item_end,
4519 new_size);
4520 if (err) {
4521 btrfs_abort_transaction(trans,
4522 root, err);
4523 goto error;
4524 }
4525 } else if (test_bit(BTRFS_ROOT_REF_COWS,
4526 &root->state)) {
4527 inode_sub_bytes(inode, item_end + 1 - new_size);
4528 }
4529 }
4530 delete:
4531 if (del_item) {
4532 if (!pending_del_nr) {
4533 /* no pending yet, add ourselves */
4534 pending_del_slot = path->slots[0];
4535 pending_del_nr = 1;
4536 } else if (pending_del_nr &&
4537 path->slots[0] + 1 == pending_del_slot) {
4538 /* hop on the pending chunk */
4539 pending_del_nr++;
4540 pending_del_slot = path->slots[0];
4541 } else {
4542 BUG();
4543 }
4544 } else {
4545 break;
4546 }
4547 should_throttle = 0;
4548
4549 if (found_extent &&
4550 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4551 root == root->fs_info->tree_root)) {
4552 btrfs_set_path_blocking(path);
4553 bytes_deleted += extent_num_bytes;
4554 ret = btrfs_free_extent(trans, root, extent_start,
4555 extent_num_bytes, 0,
4556 btrfs_header_owner(leaf),
4557 ino, extent_offset);
4558 BUG_ON(ret);
4559 if (btrfs_should_throttle_delayed_refs(trans, root))
4560 btrfs_async_run_delayed_refs(root,
4561 trans->delayed_ref_updates * 2, 0);
4562 if (be_nice) {
4563 if (truncate_space_check(trans, root,
4564 extent_num_bytes)) {
4565 should_end = 1;
4566 }
4567 if (btrfs_should_throttle_delayed_refs(trans,
4568 root)) {
4569 should_throttle = 1;
4570 }
4571 }
4572 }
4573
4574 if (found_type == BTRFS_INODE_ITEM_KEY)
4575 break;
4576
4577 if (path->slots[0] == 0 ||
4578 path->slots[0] != pending_del_slot ||
4579 should_throttle || should_end) {
4580 if (pending_del_nr) {
4581 ret = btrfs_del_items(trans, root, path,
4582 pending_del_slot,
4583 pending_del_nr);
4584 if (ret) {
4585 btrfs_abort_transaction(trans,
4586 root, ret);
4587 goto error;
4588 }
4589 pending_del_nr = 0;
4590 }
4591 btrfs_release_path(path);
4592 if (should_throttle) {
4593 unsigned long updates = trans->delayed_ref_updates;
4594 if (updates) {
4595 trans->delayed_ref_updates = 0;
4596 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4597 if (ret && !err)
4598 err = ret;
4599 }
4600 }
4601 /*
4602 * if we failed to refill our space rsv, bail out
4603 * and let the transaction restart
4604 */
4605 if (should_end) {
4606 err = -EAGAIN;
4607 goto error;
4608 }
4609 goto search_again;
4610 } else {
4611 path->slots[0]--;
4612 }
4613 }
4614 out:
4615 if (pending_del_nr) {
4616 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4617 pending_del_nr);
4618 if (ret)
4619 btrfs_abort_transaction(trans, root, ret);
4620 }
4621 error:
4622 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
4623 btrfs_ordered_update_i_size(inode, last_size, NULL);
4624
4625 btrfs_free_path(path);
4626
4627 if (be_nice && bytes_deleted > SZ_32M) {
4628 unsigned long updates = trans->delayed_ref_updates;
4629 if (updates) {
4630 trans->delayed_ref_updates = 0;
4631 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4632 if (ret && !err)
4633 err = ret;
4634 }
4635 }
4636 return err;
4637 }
4638
4639 /*
4640 * btrfs_truncate_block - read, zero a chunk and write a block
4641 * @inode - inode that we're zeroing
4642 * @from - the offset to start zeroing
4643 * @len - the length to zero, 0 to zero the entire range respective to the
4644 * offset
4645 * @front - zero up to the offset instead of from the offset on
4646 *
4647 * This will find the block for the "from" offset and cow the block and zero the
4648 * part we want to zero. This is used with truncate and hole punching.
4649 */
4650 int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
4651 int front)
4652 {
4653 struct address_space *mapping = inode->i_mapping;
4654 struct btrfs_root *root = BTRFS_I(inode)->root;
4655 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4656 struct btrfs_ordered_extent *ordered;
4657 struct extent_state *cached_state = NULL;
4658 char *kaddr;
4659 u32 blocksize = root->sectorsize;
4660 pgoff_t index = from >> PAGE_SHIFT;
4661 unsigned offset = from & (blocksize - 1);
4662 struct page *page;
4663 gfp_t mask = btrfs_alloc_write_mask(mapping);
4664 int ret = 0;
4665 u64 block_start;
4666 u64 block_end;
4667
4668 if ((offset & (blocksize - 1)) == 0 &&
4669 (!len || ((len & (blocksize - 1)) == 0)))
4670 goto out;
4671
4672 ret = btrfs_delalloc_reserve_space(inode,
4673 round_down(from, blocksize), blocksize);
4674 if (ret)
4675 goto out;
4676
4677 again:
4678 page = find_or_create_page(mapping, index, mask);
4679 if (!page) {
4680 btrfs_delalloc_release_space(inode,
4681 round_down(from, blocksize),
4682 blocksize);
4683 ret = -ENOMEM;
4684 goto out;
4685 }
4686
4687 block_start = round_down(from, blocksize);
4688 block_end = block_start + blocksize - 1;
4689
4690 if (!PageUptodate(page)) {
4691 ret = btrfs_readpage(NULL, page);
4692 lock_page(page);
4693 if (page->mapping != mapping) {
4694 unlock_page(page);
4695 put_page(page);
4696 goto again;
4697 }
4698 if (!PageUptodate(page)) {
4699 ret = -EIO;
4700 goto out_unlock;
4701 }
4702 }
4703 wait_on_page_writeback(page);
4704
4705 lock_extent_bits(io_tree, block_start, block_end, &cached_state);
4706 set_page_extent_mapped(page);
4707
4708 ordered = btrfs_lookup_ordered_extent(inode, block_start);
4709 if (ordered) {
4710 unlock_extent_cached(io_tree, block_start, block_end,
4711 &cached_state, GFP_NOFS);
4712 unlock_page(page);
4713 put_page(page);
4714 btrfs_start_ordered_extent(inode, ordered, 1);
4715 btrfs_put_ordered_extent(ordered);
4716 goto again;
4717 }
4718
4719 clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end,
4720 EXTENT_DIRTY | EXTENT_DELALLOC |
4721 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4722 0, 0, &cached_state, GFP_NOFS);
4723
4724 ret = btrfs_set_extent_delalloc(inode, block_start, block_end,
4725 &cached_state);
4726 if (ret) {
4727 unlock_extent_cached(io_tree, block_start, block_end,
4728 &cached_state, GFP_NOFS);
4729 goto out_unlock;
4730 }
4731
4732 if (offset != blocksize) {
4733 if (!len)
4734 len = blocksize - offset;
4735 kaddr = kmap(page);
4736 if (front)
4737 memset(kaddr + (block_start - page_offset(page)),
4738 0, offset);
4739 else
4740 memset(kaddr + (block_start - page_offset(page)) + offset,
4741 0, len);
4742 flush_dcache_page(page);
4743 kunmap(page);
4744 }
4745 ClearPageChecked(page);
4746 set_page_dirty(page);
4747 unlock_extent_cached(io_tree, block_start, block_end, &cached_state,
4748 GFP_NOFS);
4749
4750 out_unlock:
4751 if (ret)
4752 btrfs_delalloc_release_space(inode, block_start,
4753 blocksize);
4754 unlock_page(page);
4755 put_page(page);
4756 out:
4757 return ret;
4758 }
4759
4760 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4761 u64 offset, u64 len)
4762 {
4763 struct btrfs_trans_handle *trans;
4764 int ret;
4765
4766 /*
4767 * Still need to make sure the inode looks like it's been updated so
4768 * that any holes get logged if we fsync.
4769 */
4770 if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) {
4771 BTRFS_I(inode)->last_trans = root->fs_info->generation;
4772 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4773 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4774 return 0;
4775 }
4776
4777 /*
4778 * 1 - for the one we're dropping
4779 * 1 - for the one we're adding
4780 * 1 - for updating the inode.
4781 */
4782 trans = btrfs_start_transaction(root, 3);
4783 if (IS_ERR(trans))
4784 return PTR_ERR(trans);
4785
4786 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4787 if (ret) {
4788 btrfs_abort_transaction(trans, root, ret);
4789 btrfs_end_transaction(trans, root);
4790 return ret;
4791 }
4792
4793 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
4794 0, 0, len, 0, len, 0, 0, 0);
4795 if (ret)
4796 btrfs_abort_transaction(trans, root, ret);
4797 else
4798 btrfs_update_inode(trans, root, inode);
4799 btrfs_end_transaction(trans, root);
4800 return ret;
4801 }
4802
4803 /*
4804 * This function puts in dummy file extents for the area we're creating a hole
4805 * for. So if we are truncating this file to a larger size we need to insert
4806 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4807 * the range between oldsize and size
4808 */
4809 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4810 {
4811 struct btrfs_root *root = BTRFS_I(inode)->root;
4812 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4813 struct extent_map *em = NULL;
4814 struct extent_state *cached_state = NULL;
4815 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4816 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4817 u64 block_end = ALIGN(size, root->sectorsize);
4818 u64 last_byte;
4819 u64 cur_offset;
4820 u64 hole_size;
4821 int err = 0;
4822
4823 /*
4824 * If our size started in the middle of a block we need to zero out the
4825 * rest of the block before we expand the i_size, otherwise we could
4826 * expose stale data.
4827 */
4828 err = btrfs_truncate_block(inode, oldsize, 0, 0);
4829 if (err)
4830 return err;
4831
4832 if (size <= hole_start)
4833 return 0;
4834
4835 while (1) {
4836 struct btrfs_ordered_extent *ordered;
4837
4838 lock_extent_bits(io_tree, hole_start, block_end - 1,
4839 &cached_state);
4840 ordered = btrfs_lookup_ordered_range(inode, hole_start,
4841 block_end - hole_start);
4842 if (!ordered)
4843 break;
4844 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4845 &cached_state, GFP_NOFS);
4846 btrfs_start_ordered_extent(inode, ordered, 1);
4847 btrfs_put_ordered_extent(ordered);
4848 }
4849
4850 cur_offset = hole_start;
4851 while (1) {
4852 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4853 block_end - cur_offset, 0);
4854 if (IS_ERR(em)) {
4855 err = PTR_ERR(em);
4856 em = NULL;
4857 break;
4858 }
4859 last_byte = min(extent_map_end(em), block_end);
4860 last_byte = ALIGN(last_byte , root->sectorsize);
4861 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4862 struct extent_map *hole_em;
4863 hole_size = last_byte - cur_offset;
4864
4865 err = maybe_insert_hole(root, inode, cur_offset,
4866 hole_size);
4867 if (err)
4868 break;
4869 btrfs_drop_extent_cache(inode, cur_offset,
4870 cur_offset + hole_size - 1, 0);
4871 hole_em = alloc_extent_map();
4872 if (!hole_em) {
4873 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4874 &BTRFS_I(inode)->runtime_flags);
4875 goto next;
4876 }
4877 hole_em->start = cur_offset;
4878 hole_em->len = hole_size;
4879 hole_em->orig_start = cur_offset;
4880
4881 hole_em->block_start = EXTENT_MAP_HOLE;
4882 hole_em->block_len = 0;
4883 hole_em->orig_block_len = 0;
4884 hole_em->ram_bytes = hole_size;
4885 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4886 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4887 hole_em->generation = root->fs_info->generation;
4888
4889 while (1) {
4890 write_lock(&em_tree->lock);
4891 err = add_extent_mapping(em_tree, hole_em, 1);
4892 write_unlock(&em_tree->lock);
4893 if (err != -EEXIST)
4894 break;
4895 btrfs_drop_extent_cache(inode, cur_offset,
4896 cur_offset +
4897 hole_size - 1, 0);
4898 }
4899 free_extent_map(hole_em);
4900 }
4901 next:
4902 free_extent_map(em);
4903 em = NULL;
4904 cur_offset = last_byte;
4905 if (cur_offset >= block_end)
4906 break;
4907 }
4908 free_extent_map(em);
4909 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4910 GFP_NOFS);
4911 return err;
4912 }
4913
4914 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4915 {
4916 struct btrfs_root *root = BTRFS_I(inode)->root;
4917 struct btrfs_trans_handle *trans;
4918 loff_t oldsize = i_size_read(inode);
4919 loff_t newsize = attr->ia_size;
4920 int mask = attr->ia_valid;
4921 int ret;
4922
4923 /*
4924 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4925 * special case where we need to update the times despite not having
4926 * these flags set. For all other operations the VFS set these flags
4927 * explicitly if it wants a timestamp update.
4928 */
4929 if (newsize != oldsize) {
4930 inode_inc_iversion(inode);
4931 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
4932 inode->i_ctime = inode->i_mtime =
4933 current_fs_time(inode->i_sb);
4934 }
4935
4936 if (newsize > oldsize) {
4937 /*
4938 * Don't do an expanding truncate while snapshoting is ongoing.
4939 * This is to ensure the snapshot captures a fully consistent
4940 * state of this file - if the snapshot captures this expanding
4941 * truncation, it must capture all writes that happened before
4942 * this truncation.
4943 */
4944 btrfs_wait_for_snapshot_creation(root);
4945 ret = btrfs_cont_expand(inode, oldsize, newsize);
4946 if (ret) {
4947 btrfs_end_write_no_snapshoting(root);
4948 return ret;
4949 }
4950
4951 trans = btrfs_start_transaction(root, 1);
4952 if (IS_ERR(trans)) {
4953 btrfs_end_write_no_snapshoting(root);
4954 return PTR_ERR(trans);
4955 }
4956
4957 i_size_write(inode, newsize);
4958 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4959 pagecache_isize_extended(inode, oldsize, newsize);
4960 ret = btrfs_update_inode(trans, root, inode);
4961 btrfs_end_write_no_snapshoting(root);
4962 btrfs_end_transaction(trans, root);
4963 } else {
4964
4965 /*
4966 * We're truncating a file that used to have good data down to
4967 * zero. Make sure it gets into the ordered flush list so that
4968 * any new writes get down to disk quickly.
4969 */
4970 if (newsize == 0)
4971 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
4972 &BTRFS_I(inode)->runtime_flags);
4973
4974 /*
4975 * 1 for the orphan item we're going to add
4976 * 1 for the orphan item deletion.
4977 */
4978 trans = btrfs_start_transaction(root, 2);
4979 if (IS_ERR(trans))
4980 return PTR_ERR(trans);
4981
4982 /*
4983 * We need to do this in case we fail at _any_ point during the
4984 * actual truncate. Once we do the truncate_setsize we could
4985 * invalidate pages which forces any outstanding ordered io to
4986 * be instantly completed which will give us extents that need
4987 * to be truncated. If we fail to get an orphan inode down we
4988 * could have left over extents that were never meant to live,
4989 * so we need to guarantee from this point on that everything
4990 * will be consistent.
4991 */
4992 ret = btrfs_orphan_add(trans, inode);
4993 btrfs_end_transaction(trans, root);
4994 if (ret)
4995 return ret;
4996
4997 /* we don't support swapfiles, so vmtruncate shouldn't fail */
4998 truncate_setsize(inode, newsize);
4999
5000 /* Disable nonlocked read DIO to avoid the end less truncate */
5001 btrfs_inode_block_unlocked_dio(inode);
5002 inode_dio_wait(inode);
5003 btrfs_inode_resume_unlocked_dio(inode);
5004
5005 ret = btrfs_truncate(inode);
5006 if (ret && inode->i_nlink) {
5007 int err;
5008
5009 /*
5010 * failed to truncate, disk_i_size is only adjusted down
5011 * as we remove extents, so it should represent the true
5012 * size of the inode, so reset the in memory size and
5013 * delete our orphan entry.
5014 */
5015 trans = btrfs_join_transaction(root);
5016 if (IS_ERR(trans)) {
5017 btrfs_orphan_del(NULL, inode);
5018 return ret;
5019 }
5020 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
5021 err = btrfs_orphan_del(trans, inode);
5022 if (err)
5023 btrfs_abort_transaction(trans, root, err);
5024 btrfs_end_transaction(trans, root);
5025 }
5026 }
5027
5028 return ret;
5029 }
5030
5031 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
5032 {
5033 struct inode *inode = d_inode(dentry);
5034 struct btrfs_root *root = BTRFS_I(inode)->root;
5035 int err;
5036
5037 if (btrfs_root_readonly(root))
5038 return -EROFS;
5039
5040 err = inode_change_ok(inode, attr);
5041 if (err)
5042 return err;
5043
5044 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
5045 err = btrfs_setsize(inode, attr);
5046 if (err)
5047 return err;
5048 }
5049
5050 if (attr->ia_valid) {
5051 setattr_copy(inode, attr);
5052 inode_inc_iversion(inode);
5053 err = btrfs_dirty_inode(inode);
5054
5055 if (!err && attr->ia_valid & ATTR_MODE)
5056 err = posix_acl_chmod(inode, inode->i_mode);
5057 }
5058
5059 return err;
5060 }
5061
5062 /*
5063 * While truncating the inode pages during eviction, we get the VFS calling
5064 * btrfs_invalidatepage() against each page of the inode. This is slow because
5065 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
5066 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
5067 * extent_state structures over and over, wasting lots of time.
5068 *
5069 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
5070 * those expensive operations on a per page basis and do only the ordered io
5071 * finishing, while we release here the extent_map and extent_state structures,
5072 * without the excessive merging and splitting.
5073 */
5074 static void evict_inode_truncate_pages(struct inode *inode)
5075 {
5076 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5077 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
5078 struct rb_node *node;
5079
5080 ASSERT(inode->i_state & I_FREEING);
5081 truncate_inode_pages_final(&inode->i_data);
5082
5083 write_lock(&map_tree->lock);
5084 while (!RB_EMPTY_ROOT(&map_tree->map)) {
5085 struct extent_map *em;
5086
5087 node = rb_first(&map_tree->map);
5088 em = rb_entry(node, struct extent_map, rb_node);
5089 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
5090 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
5091 remove_extent_mapping(map_tree, em);
5092 free_extent_map(em);
5093 if (need_resched()) {
5094 write_unlock(&map_tree->lock);
5095 cond_resched();
5096 write_lock(&map_tree->lock);
5097 }
5098 }
5099 write_unlock(&map_tree->lock);
5100
5101 /*
5102 * Keep looping until we have no more ranges in the io tree.
5103 * We can have ongoing bios started by readpages (called from readahead)
5104 * that have their endio callback (extent_io.c:end_bio_extent_readpage)
5105 * still in progress (unlocked the pages in the bio but did not yet
5106 * unlocked the ranges in the io tree). Therefore this means some
5107 * ranges can still be locked and eviction started because before
5108 * submitting those bios, which are executed by a separate task (work
5109 * queue kthread), inode references (inode->i_count) were not taken
5110 * (which would be dropped in the end io callback of each bio).
5111 * Therefore here we effectively end up waiting for those bios and
5112 * anyone else holding locked ranges without having bumped the inode's
5113 * reference count - if we don't do it, when they access the inode's
5114 * io_tree to unlock a range it may be too late, leading to an
5115 * use-after-free issue.
5116 */
5117 spin_lock(&io_tree->lock);
5118 while (!RB_EMPTY_ROOT(&io_tree->state)) {
5119 struct extent_state *state;
5120 struct extent_state *cached_state = NULL;
5121 u64 start;
5122 u64 end;
5123
5124 node = rb_first(&io_tree->state);
5125 state = rb_entry(node, struct extent_state, rb_node);
5126 start = state->start;
5127 end = state->end;
5128 spin_unlock(&io_tree->lock);
5129
5130 lock_extent_bits(io_tree, start, end, &cached_state);
5131
5132 /*
5133 * If still has DELALLOC flag, the extent didn't reach disk,
5134 * and its reserved space won't be freed by delayed_ref.
5135 * So we need to free its reserved space here.
5136 * (Refer to comment in btrfs_invalidatepage, case 2)
5137 *
5138 * Note, end is the bytenr of last byte, so we need + 1 here.
5139 */
5140 if (state->state & EXTENT_DELALLOC)
5141 btrfs_qgroup_free_data(inode, start, end - start + 1);
5142
5143 clear_extent_bit(io_tree, start, end,
5144 EXTENT_LOCKED | EXTENT_DIRTY |
5145 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
5146 EXTENT_DEFRAG, 1, 1,
5147 &cached_state, GFP_NOFS);
5148
5149 cond_resched();
5150 spin_lock(&io_tree->lock);
5151 }
5152 spin_unlock(&io_tree->lock);
5153 }
5154
5155 void btrfs_evict_inode(struct inode *inode)
5156 {
5157 struct btrfs_trans_handle *trans;
5158 struct btrfs_root *root = BTRFS_I(inode)->root;
5159 struct btrfs_block_rsv *rsv, *global_rsv;
5160 int steal_from_global = 0;
5161 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
5162 int ret;
5163
5164 trace_btrfs_inode_evict(inode);
5165
5166 evict_inode_truncate_pages(inode);
5167
5168 if (inode->i_nlink &&
5169 ((btrfs_root_refs(&root->root_item) != 0 &&
5170 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5171 btrfs_is_free_space_inode(inode)))
5172 goto no_delete;
5173
5174 if (is_bad_inode(inode)) {
5175 btrfs_orphan_del(NULL, inode);
5176 goto no_delete;
5177 }
5178 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
5179 if (!special_file(inode->i_mode))
5180 btrfs_wait_ordered_range(inode, 0, (u64)-1);
5181
5182 btrfs_free_io_failure_record(inode, 0, (u64)-1);
5183
5184 if (root->fs_info->log_root_recovering) {
5185 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
5186 &BTRFS_I(inode)->runtime_flags));
5187 goto no_delete;
5188 }
5189
5190 if (inode->i_nlink > 0) {
5191 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5192 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5193 goto no_delete;
5194 }
5195
5196 ret = btrfs_commit_inode_delayed_inode(inode);
5197 if (ret) {
5198 btrfs_orphan_del(NULL, inode);
5199 goto no_delete;
5200 }
5201
5202 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
5203 if (!rsv) {
5204 btrfs_orphan_del(NULL, inode);
5205 goto no_delete;
5206 }
5207 rsv->size = min_size;
5208 rsv->failfast = 1;
5209 global_rsv = &root->fs_info->global_block_rsv;
5210
5211 btrfs_i_size_write(inode, 0);
5212
5213 /*
5214 * This is a bit simpler than btrfs_truncate since we've already
5215 * reserved our space for our orphan item in the unlink, so we just
5216 * need to reserve some slack space in case we add bytes and update
5217 * inode item when doing the truncate.
5218 */
5219 while (1) {
5220 ret = btrfs_block_rsv_refill(root, rsv, min_size,
5221 BTRFS_RESERVE_FLUSH_LIMIT);
5222
5223 /*
5224 * Try and steal from the global reserve since we will
5225 * likely not use this space anyway, we want to try as
5226 * hard as possible to get this to work.
5227 */
5228 if (ret)
5229 steal_from_global++;
5230 else
5231 steal_from_global = 0;
5232 ret = 0;
5233
5234 /*
5235 * steal_from_global == 0: we reserved stuff, hooray!
5236 * steal_from_global == 1: we didn't reserve stuff, boo!
5237 * steal_from_global == 2: we've committed, still not a lot of
5238 * room but maybe we'll have room in the global reserve this
5239 * time.
5240 * steal_from_global == 3: abandon all hope!
5241 */
5242 if (steal_from_global > 2) {
5243 btrfs_warn(root->fs_info,
5244 "Could not get space for a delete, will truncate on mount %d",
5245 ret);
5246 btrfs_orphan_del(NULL, inode);
5247 btrfs_free_block_rsv(root, rsv);
5248 goto no_delete;
5249 }
5250
5251 trans = btrfs_join_transaction(root);
5252 if (IS_ERR(trans)) {
5253 btrfs_orphan_del(NULL, inode);
5254 btrfs_free_block_rsv(root, rsv);
5255 goto no_delete;
5256 }
5257
5258 /*
5259 * We can't just steal from the global reserve, we need to make
5260 * sure there is room to do it, if not we need to commit and try
5261 * again.
5262 */
5263 if (steal_from_global) {
5264 if (!btrfs_check_space_for_delayed_refs(trans, root))
5265 ret = btrfs_block_rsv_migrate(global_rsv, rsv,
5266 min_size);
5267 else
5268 ret = -ENOSPC;
5269 }
5270
5271 /*
5272 * Couldn't steal from the global reserve, we have too much
5273 * pending stuff built up, commit the transaction and try it
5274 * again.
5275 */
5276 if (ret) {
5277 ret = btrfs_commit_transaction(trans, root);
5278 if (ret) {
5279 btrfs_orphan_del(NULL, inode);
5280 btrfs_free_block_rsv(root, rsv);
5281 goto no_delete;
5282 }
5283 continue;
5284 } else {
5285 steal_from_global = 0;
5286 }
5287
5288 trans->block_rsv = rsv;
5289
5290 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5291 if (ret != -ENOSPC && ret != -EAGAIN)
5292 break;
5293
5294 trans->block_rsv = &root->fs_info->trans_block_rsv;
5295 btrfs_end_transaction(trans, root);
5296 trans = NULL;
5297 btrfs_btree_balance_dirty(root);
5298 }
5299
5300 btrfs_free_block_rsv(root, rsv);
5301
5302 /*
5303 * Errors here aren't a big deal, it just means we leave orphan items
5304 * in the tree. They will be cleaned up on the next mount.
5305 */
5306 if (ret == 0) {
5307 trans->block_rsv = root->orphan_block_rsv;
5308 btrfs_orphan_del(trans, inode);
5309 } else {
5310 btrfs_orphan_del(NULL, inode);
5311 }
5312
5313 trans->block_rsv = &root->fs_info->trans_block_rsv;
5314 if (!(root == root->fs_info->tree_root ||
5315 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5316 btrfs_return_ino(root, btrfs_ino(inode));
5317
5318 btrfs_end_transaction(trans, root);
5319 btrfs_btree_balance_dirty(root);
5320 no_delete:
5321 btrfs_remove_delayed_node(inode);
5322 clear_inode(inode);
5323 }
5324
5325 /*
5326 * this returns the key found in the dir entry in the location pointer.
5327 * If no dir entries were found, location->objectid is 0.
5328 */
5329 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5330 struct btrfs_key *location)
5331 {
5332 const char *name = dentry->d_name.name;
5333 int namelen = dentry->d_name.len;
5334 struct btrfs_dir_item *di;
5335 struct btrfs_path *path;
5336 struct btrfs_root *root = BTRFS_I(dir)->root;
5337 int ret = 0;
5338
5339 path = btrfs_alloc_path();
5340 if (!path)
5341 return -ENOMEM;
5342
5343 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
5344 namelen, 0);
5345 if (IS_ERR(di))
5346 ret = PTR_ERR(di);
5347
5348 if (IS_ERR_OR_NULL(di))
5349 goto out_err;
5350
5351 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5352 out:
5353 btrfs_free_path(path);
5354 return ret;
5355 out_err:
5356 location->objectid = 0;
5357 goto out;
5358 }
5359
5360 /*
5361 * when we hit a tree root in a directory, the btrfs part of the inode
5362 * needs to be changed to reflect the root directory of the tree root. This
5363 * is kind of like crossing a mount point.
5364 */
5365 static int fixup_tree_root_location(struct btrfs_root *root,
5366 struct inode *dir,
5367 struct dentry *dentry,
5368 struct btrfs_key *location,
5369 struct btrfs_root **sub_root)
5370 {
5371 struct btrfs_path *path;
5372 struct btrfs_root *new_root;
5373 struct btrfs_root_ref *ref;
5374 struct extent_buffer *leaf;
5375 struct btrfs_key key;
5376 int ret;
5377 int err = 0;
5378
5379 path = btrfs_alloc_path();
5380 if (!path) {
5381 err = -ENOMEM;
5382 goto out;
5383 }
5384
5385 err = -ENOENT;
5386 key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5387 key.type = BTRFS_ROOT_REF_KEY;
5388 key.offset = location->objectid;
5389
5390 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, path,
5391 0, 0);
5392 if (ret) {
5393 if (ret < 0)
5394 err = ret;
5395 goto out;
5396 }
5397
5398 leaf = path->nodes[0];
5399 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5400 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
5401 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5402 goto out;
5403
5404 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5405 (unsigned long)(ref + 1),
5406 dentry->d_name.len);
5407 if (ret)
5408 goto out;
5409
5410 btrfs_release_path(path);
5411
5412 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
5413 if (IS_ERR(new_root)) {
5414 err = PTR_ERR(new_root);
5415 goto out;
5416 }
5417
5418 *sub_root = new_root;
5419 location->objectid = btrfs_root_dirid(&new_root->root_item);
5420 location->type = BTRFS_INODE_ITEM_KEY;
5421 location->offset = 0;
5422 err = 0;
5423 out:
5424 btrfs_free_path(path);
5425 return err;
5426 }
5427
5428 static void inode_tree_add(struct inode *inode)
5429 {
5430 struct btrfs_root *root = BTRFS_I(inode)->root;
5431 struct btrfs_inode *entry;
5432 struct rb_node **p;
5433 struct rb_node *parent;
5434 struct rb_node *new = &BTRFS_I(inode)->rb_node;
5435 u64 ino = btrfs_ino(inode);
5436
5437 if (inode_unhashed(inode))
5438 return;
5439 parent = NULL;
5440 spin_lock(&root->inode_lock);
5441 p = &root->inode_tree.rb_node;
5442 while (*p) {
5443 parent = *p;
5444 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5445
5446 if (ino < btrfs_ino(&entry->vfs_inode))
5447 p = &parent->rb_left;
5448 else if (ino > btrfs_ino(&entry->vfs_inode))
5449 p = &parent->rb_right;
5450 else {
5451 WARN_ON(!(entry->vfs_inode.i_state &
5452 (I_WILL_FREE | I_FREEING)));
5453 rb_replace_node(parent, new, &root->inode_tree);
5454 RB_CLEAR_NODE(parent);
5455 spin_unlock(&root->inode_lock);
5456 return;
5457 }
5458 }
5459 rb_link_node(new, parent, p);
5460 rb_insert_color(new, &root->inode_tree);
5461 spin_unlock(&root->inode_lock);
5462 }
5463
5464 static void inode_tree_del(struct inode *inode)
5465 {
5466 struct btrfs_root *root = BTRFS_I(inode)->root;
5467 int empty = 0;
5468
5469 spin_lock(&root->inode_lock);
5470 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5471 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5472 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5473 empty = RB_EMPTY_ROOT(&root->inode_tree);
5474 }
5475 spin_unlock(&root->inode_lock);
5476
5477 if (empty && btrfs_root_refs(&root->root_item) == 0) {
5478 synchronize_srcu(&root->fs_info->subvol_srcu);
5479 spin_lock(&root->inode_lock);
5480 empty = RB_EMPTY_ROOT(&root->inode_tree);
5481 spin_unlock(&root->inode_lock);
5482 if (empty)
5483 btrfs_add_dead_root(root);
5484 }
5485 }
5486
5487 void btrfs_invalidate_inodes(struct btrfs_root *root)
5488 {
5489 struct rb_node *node;
5490 struct rb_node *prev;
5491 struct btrfs_inode *entry;
5492 struct inode *inode;
5493 u64 objectid = 0;
5494
5495 if (!test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
5496 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
5497
5498 spin_lock(&root->inode_lock);
5499 again:
5500 node = root->inode_tree.rb_node;
5501 prev = NULL;
5502 while (node) {
5503 prev = node;
5504 entry = rb_entry(node, struct btrfs_inode, rb_node);
5505
5506 if (objectid < btrfs_ino(&entry->vfs_inode))
5507 node = node->rb_left;
5508 else if (objectid > btrfs_ino(&entry->vfs_inode))
5509 node = node->rb_right;
5510 else
5511 break;
5512 }
5513 if (!node) {
5514 while (prev) {
5515 entry = rb_entry(prev, struct btrfs_inode, rb_node);
5516 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
5517 node = prev;
5518 break;
5519 }
5520 prev = rb_next(prev);
5521 }
5522 }
5523 while (node) {
5524 entry = rb_entry(node, struct btrfs_inode, rb_node);
5525 objectid = btrfs_ino(&entry->vfs_inode) + 1;
5526 inode = igrab(&entry->vfs_inode);
5527 if (inode) {
5528 spin_unlock(&root->inode_lock);
5529 if (atomic_read(&inode->i_count) > 1)
5530 d_prune_aliases(inode);
5531 /*
5532 * btrfs_drop_inode will have it removed from
5533 * the inode cache when its usage count
5534 * hits zero.
5535 */
5536 iput(inode);
5537 cond_resched();
5538 spin_lock(&root->inode_lock);
5539 goto again;
5540 }
5541
5542 if (cond_resched_lock(&root->inode_lock))
5543 goto again;
5544
5545 node = rb_next(node);
5546 }
5547 spin_unlock(&root->inode_lock);
5548 }
5549
5550 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5551 {
5552 struct btrfs_iget_args *args = p;
5553 inode->i_ino = args->location->objectid;
5554 memcpy(&BTRFS_I(inode)->location, args->location,
5555 sizeof(*args->location));
5556 BTRFS_I(inode)->root = args->root;
5557 return 0;
5558 }
5559
5560 static int btrfs_find_actor(struct inode *inode, void *opaque)
5561 {
5562 struct btrfs_iget_args *args = opaque;
5563 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5564 args->root == BTRFS_I(inode)->root;
5565 }
5566
5567 static struct inode *btrfs_iget_locked(struct super_block *s,
5568 struct btrfs_key *location,
5569 struct btrfs_root *root)
5570 {
5571 struct inode *inode;
5572 struct btrfs_iget_args args;
5573 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5574
5575 args.location = location;
5576 args.root = root;
5577
5578 inode = iget5_locked(s, hashval, btrfs_find_actor,
5579 btrfs_init_locked_inode,
5580 (void *)&args);
5581 return inode;
5582 }
5583
5584 /* Get an inode object given its location and corresponding root.
5585 * Returns in *is_new if the inode was read from disk
5586 */
5587 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5588 struct btrfs_root *root, int *new)
5589 {
5590 struct inode *inode;
5591
5592 inode = btrfs_iget_locked(s, location, root);
5593 if (!inode)
5594 return ERR_PTR(-ENOMEM);
5595
5596 if (inode->i_state & I_NEW) {
5597 btrfs_read_locked_inode(inode);
5598 if (!is_bad_inode(inode)) {
5599 inode_tree_add(inode);
5600 unlock_new_inode(inode);
5601 if (new)
5602 *new = 1;
5603 } else {
5604 unlock_new_inode(inode);
5605 iput(inode);
5606 inode = ERR_PTR(-ESTALE);
5607 }
5608 }
5609
5610 return inode;
5611 }
5612
5613 static struct inode *new_simple_dir(struct super_block *s,
5614 struct btrfs_key *key,
5615 struct btrfs_root *root)
5616 {
5617 struct inode *inode = new_inode(s);
5618
5619 if (!inode)
5620 return ERR_PTR(-ENOMEM);
5621
5622 BTRFS_I(inode)->root = root;
5623 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5624 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5625
5626 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5627 inode->i_op = &btrfs_dir_ro_inode_operations;
5628 inode->i_fop = &simple_dir_operations;
5629 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5630 inode->i_mtime = current_fs_time(inode->i_sb);
5631 inode->i_atime = inode->i_mtime;
5632 inode->i_ctime = inode->i_mtime;
5633 BTRFS_I(inode)->i_otime = inode->i_mtime;
5634
5635 return inode;
5636 }
5637
5638 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5639 {
5640 struct inode *inode;
5641 struct btrfs_root *root = BTRFS_I(dir)->root;
5642 struct btrfs_root *sub_root = root;
5643 struct btrfs_key location;
5644 int index;
5645 int ret = 0;
5646
5647 if (dentry->d_name.len > BTRFS_NAME_LEN)
5648 return ERR_PTR(-ENAMETOOLONG);
5649
5650 ret = btrfs_inode_by_name(dir, dentry, &location);
5651 if (ret < 0)
5652 return ERR_PTR(ret);
5653
5654 if (location.objectid == 0)
5655 return ERR_PTR(-ENOENT);
5656
5657 if (location.type == BTRFS_INODE_ITEM_KEY) {
5658 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5659 return inode;
5660 }
5661
5662 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5663
5664 index = srcu_read_lock(&root->fs_info->subvol_srcu);
5665 ret = fixup_tree_root_location(root, dir, dentry,
5666 &location, &sub_root);
5667 if (ret < 0) {
5668 if (ret != -ENOENT)
5669 inode = ERR_PTR(ret);
5670 else
5671 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5672 } else {
5673 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5674 }
5675 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
5676
5677 if (!IS_ERR(inode) && root != sub_root) {
5678 down_read(&root->fs_info->cleanup_work_sem);
5679 if (!(inode->i_sb->s_flags & MS_RDONLY))
5680 ret = btrfs_orphan_cleanup(sub_root);
5681 up_read(&root->fs_info->cleanup_work_sem);
5682 if (ret) {
5683 iput(inode);
5684 inode = ERR_PTR(ret);
5685 }
5686 }
5687
5688 return inode;
5689 }
5690
5691 static int btrfs_dentry_delete(const struct dentry *dentry)
5692 {
5693 struct btrfs_root *root;
5694 struct inode *inode = d_inode(dentry);
5695
5696 if (!inode && !IS_ROOT(dentry))
5697 inode = d_inode(dentry->d_parent);
5698
5699 if (inode) {
5700 root = BTRFS_I(inode)->root;
5701 if (btrfs_root_refs(&root->root_item) == 0)
5702 return 1;
5703
5704 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5705 return 1;
5706 }
5707 return 0;
5708 }
5709
5710 static void btrfs_dentry_release(struct dentry *dentry)
5711 {
5712 kfree(dentry->d_fsdata);
5713 }
5714
5715 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5716 unsigned int flags)
5717 {
5718 struct inode *inode;
5719
5720 inode = btrfs_lookup_dentry(dir, dentry);
5721 if (IS_ERR(inode)) {
5722 if (PTR_ERR(inode) == -ENOENT)
5723 inode = NULL;
5724 else
5725 return ERR_CAST(inode);
5726 }
5727
5728 return d_splice_alias(inode, dentry);
5729 }
5730
5731 unsigned char btrfs_filetype_table[] = {
5732 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5733 };
5734
5735 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5736 {
5737 struct inode *inode = file_inode(file);
5738 struct btrfs_root *root = BTRFS_I(inode)->root;
5739 struct btrfs_item *item;
5740 struct btrfs_dir_item *di;
5741 struct btrfs_key key;
5742 struct btrfs_key found_key;
5743 struct btrfs_path *path;
5744 struct list_head ins_list;
5745 struct list_head del_list;
5746 int ret;
5747 struct extent_buffer *leaf;
5748 int slot;
5749 unsigned char d_type;
5750 int over = 0;
5751 u32 di_cur;
5752 u32 di_total;
5753 u32 di_len;
5754 int key_type = BTRFS_DIR_INDEX_KEY;
5755 char tmp_name[32];
5756 char *name_ptr;
5757 int name_len;
5758 int is_curr = 0; /* ctx->pos points to the current index? */
5759 bool emitted;
5760
5761 /* FIXME, use a real flag for deciding about the key type */
5762 if (root->fs_info->tree_root == root)
5763 key_type = BTRFS_DIR_ITEM_KEY;
5764
5765 if (!dir_emit_dots(file, ctx))
5766 return 0;
5767
5768 path = btrfs_alloc_path();
5769 if (!path)
5770 return -ENOMEM;
5771
5772 path->reada = READA_FORWARD;
5773
5774 if (key_type == BTRFS_DIR_INDEX_KEY) {
5775 INIT_LIST_HEAD(&ins_list);
5776 INIT_LIST_HEAD(&del_list);
5777 btrfs_get_delayed_items(inode, &ins_list, &del_list);
5778 }
5779
5780 key.type = key_type;
5781 key.offset = ctx->pos;
5782 key.objectid = btrfs_ino(inode);
5783
5784 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5785 if (ret < 0)
5786 goto err;
5787
5788 emitted = false;
5789 while (1) {
5790 leaf = path->nodes[0];
5791 slot = path->slots[0];
5792 if (slot >= btrfs_header_nritems(leaf)) {
5793 ret = btrfs_next_leaf(root, path);
5794 if (ret < 0)
5795 goto err;
5796 else if (ret > 0)
5797 break;
5798 continue;
5799 }
5800
5801 item = btrfs_item_nr(slot);
5802 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5803
5804 if (found_key.objectid != key.objectid)
5805 break;
5806 if (found_key.type != key_type)
5807 break;
5808 if (found_key.offset < ctx->pos)
5809 goto next;
5810 if (key_type == BTRFS_DIR_INDEX_KEY &&
5811 btrfs_should_delete_dir_index(&del_list,
5812 found_key.offset))
5813 goto next;
5814
5815 ctx->pos = found_key.offset;
5816 is_curr = 1;
5817
5818 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5819 di_cur = 0;
5820 di_total = btrfs_item_size(leaf, item);
5821
5822 while (di_cur < di_total) {
5823 struct btrfs_key location;
5824
5825 if (verify_dir_item(root, leaf, di))
5826 break;
5827
5828 name_len = btrfs_dir_name_len(leaf, di);
5829 if (name_len <= sizeof(tmp_name)) {
5830 name_ptr = tmp_name;
5831 } else {
5832 name_ptr = kmalloc(name_len, GFP_KERNEL);
5833 if (!name_ptr) {
5834 ret = -ENOMEM;
5835 goto err;
5836 }
5837 }
5838 read_extent_buffer(leaf, name_ptr,
5839 (unsigned long)(di + 1), name_len);
5840
5841 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5842 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5843
5844
5845 /* is this a reference to our own snapshot? If so
5846 * skip it.
5847 *
5848 * In contrast to old kernels, we insert the snapshot's
5849 * dir item and dir index after it has been created, so
5850 * we won't find a reference to our own snapshot. We
5851 * still keep the following code for backward
5852 * compatibility.
5853 */
5854 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5855 location.objectid == root->root_key.objectid) {
5856 over = 0;
5857 goto skip;
5858 }
5859 over = !dir_emit(ctx, name_ptr, name_len,
5860 location.objectid, d_type);
5861
5862 skip:
5863 if (name_ptr != tmp_name)
5864 kfree(name_ptr);
5865
5866 if (over)
5867 goto nopos;
5868 emitted = true;
5869 di_len = btrfs_dir_name_len(leaf, di) +
5870 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5871 di_cur += di_len;
5872 di = (struct btrfs_dir_item *)((char *)di + di_len);
5873 }
5874 next:
5875 path->slots[0]++;
5876 }
5877
5878 if (key_type == BTRFS_DIR_INDEX_KEY) {
5879 if (is_curr)
5880 ctx->pos++;
5881 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list, &emitted);
5882 if (ret)
5883 goto nopos;
5884 }
5885
5886 /*
5887 * If we haven't emitted any dir entry, we must not touch ctx->pos as
5888 * it was was set to the termination value in previous call. We assume
5889 * that "." and ".." were emitted if we reach this point and set the
5890 * termination value as well for an empty directory.
5891 */
5892 if (ctx->pos > 2 && !emitted)
5893 goto nopos;
5894
5895 /* Reached end of directory/root. Bump pos past the last item. */
5896 ctx->pos++;
5897
5898 /*
5899 * Stop new entries from being returned after we return the last
5900 * entry.
5901 *
5902 * New directory entries are assigned a strictly increasing
5903 * offset. This means that new entries created during readdir
5904 * are *guaranteed* to be seen in the future by that readdir.
5905 * This has broken buggy programs which operate on names as
5906 * they're returned by readdir. Until we re-use freed offsets
5907 * we have this hack to stop new entries from being returned
5908 * under the assumption that they'll never reach this huge
5909 * offset.
5910 *
5911 * This is being careful not to overflow 32bit loff_t unless the
5912 * last entry requires it because doing so has broken 32bit apps
5913 * in the past.
5914 */
5915 if (key_type == BTRFS_DIR_INDEX_KEY) {
5916 if (ctx->pos >= INT_MAX)
5917 ctx->pos = LLONG_MAX;
5918 else
5919 ctx->pos = INT_MAX;
5920 }
5921 nopos:
5922 ret = 0;
5923 err:
5924 if (key_type == BTRFS_DIR_INDEX_KEY)
5925 btrfs_put_delayed_items(&ins_list, &del_list);
5926 btrfs_free_path(path);
5927 return ret;
5928 }
5929
5930 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5931 {
5932 struct btrfs_root *root = BTRFS_I(inode)->root;
5933 struct btrfs_trans_handle *trans;
5934 int ret = 0;
5935 bool nolock = false;
5936
5937 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5938 return 0;
5939
5940 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5941 nolock = true;
5942
5943 if (wbc->sync_mode == WB_SYNC_ALL) {
5944 if (nolock)
5945 trans = btrfs_join_transaction_nolock(root);
5946 else
5947 trans = btrfs_join_transaction(root);
5948 if (IS_ERR(trans))
5949 return PTR_ERR(trans);
5950 ret = btrfs_commit_transaction(trans, root);
5951 }
5952 return ret;
5953 }
5954
5955 /*
5956 * This is somewhat expensive, updating the tree every time the
5957 * inode changes. But, it is most likely to find the inode in cache.
5958 * FIXME, needs more benchmarking...there are no reasons other than performance
5959 * to keep or drop this code.
5960 */
5961 static int btrfs_dirty_inode(struct inode *inode)
5962 {
5963 struct btrfs_root *root = BTRFS_I(inode)->root;
5964 struct btrfs_trans_handle *trans;
5965 int ret;
5966
5967 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5968 return 0;
5969
5970 trans = btrfs_join_transaction(root);
5971 if (IS_ERR(trans))
5972 return PTR_ERR(trans);
5973
5974 ret = btrfs_update_inode(trans, root, inode);
5975 if (ret && ret == -ENOSPC) {
5976 /* whoops, lets try again with the full transaction */
5977 btrfs_end_transaction(trans, root);
5978 trans = btrfs_start_transaction(root, 1);
5979 if (IS_ERR(trans))
5980 return PTR_ERR(trans);
5981
5982 ret = btrfs_update_inode(trans, root, inode);
5983 }
5984 btrfs_end_transaction(trans, root);
5985 if (BTRFS_I(inode)->delayed_node)
5986 btrfs_balance_delayed_items(root);
5987
5988 return ret;
5989 }
5990
5991 /*
5992 * This is a copy of file_update_time. We need this so we can return error on
5993 * ENOSPC for updating the inode in the case of file write and mmap writes.
5994 */
5995 static int btrfs_update_time(struct inode *inode, struct timespec *now,
5996 int flags)
5997 {
5998 struct btrfs_root *root = BTRFS_I(inode)->root;
5999
6000 if (btrfs_root_readonly(root))
6001 return -EROFS;
6002
6003 if (flags & S_VERSION)
6004 inode_inc_iversion(inode);
6005 if (flags & S_CTIME)
6006 inode->i_ctime = *now;
6007 if (flags & S_MTIME)
6008 inode->i_mtime = *now;
6009 if (flags & S_ATIME)
6010 inode->i_atime = *now;
6011 return btrfs_dirty_inode(inode);
6012 }
6013
6014 /*
6015 * find the highest existing sequence number in a directory
6016 * and then set the in-memory index_cnt variable to reflect
6017 * free sequence numbers
6018 */
6019 static int btrfs_set_inode_index_count(struct inode *inode)
6020 {
6021 struct btrfs_root *root = BTRFS_I(inode)->root;
6022 struct btrfs_key key, found_key;
6023 struct btrfs_path *path;
6024 struct extent_buffer *leaf;
6025 int ret;
6026
6027 key.objectid = btrfs_ino(inode);
6028 key.type = BTRFS_DIR_INDEX_KEY;
6029 key.offset = (u64)-1;
6030
6031 path = btrfs_alloc_path();
6032 if (!path)
6033 return -ENOMEM;
6034
6035 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6036 if (ret < 0)
6037 goto out;
6038 /* FIXME: we should be able to handle this */
6039 if (ret == 0)
6040 goto out;
6041 ret = 0;
6042
6043 /*
6044 * MAGIC NUMBER EXPLANATION:
6045 * since we search a directory based on f_pos we have to start at 2
6046 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
6047 * else has to start at 2
6048 */
6049 if (path->slots[0] == 0) {
6050 BTRFS_I(inode)->index_cnt = 2;
6051 goto out;
6052 }
6053
6054 path->slots[0]--;
6055
6056 leaf = path->nodes[0];
6057 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6058
6059 if (found_key.objectid != btrfs_ino(inode) ||
6060 found_key.type != BTRFS_DIR_INDEX_KEY) {
6061 BTRFS_I(inode)->index_cnt = 2;
6062 goto out;
6063 }
6064
6065 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
6066 out:
6067 btrfs_free_path(path);
6068 return ret;
6069 }
6070
6071 /*
6072 * helper to find a free sequence number in a given directory. This current
6073 * code is very simple, later versions will do smarter things in the btree
6074 */
6075 int btrfs_set_inode_index(struct inode *dir, u64 *index)
6076 {
6077 int ret = 0;
6078
6079 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
6080 ret = btrfs_inode_delayed_dir_index_count(dir);
6081 if (ret) {
6082 ret = btrfs_set_inode_index_count(dir);
6083 if (ret)
6084 return ret;
6085 }
6086 }
6087
6088 *index = BTRFS_I(dir)->index_cnt;
6089 BTRFS_I(dir)->index_cnt++;
6090
6091 return ret;
6092 }
6093
6094 static int btrfs_insert_inode_locked(struct inode *inode)
6095 {
6096 struct btrfs_iget_args args;
6097 args.location = &BTRFS_I(inode)->location;
6098 args.root = BTRFS_I(inode)->root;
6099
6100 return insert_inode_locked4(inode,
6101 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
6102 btrfs_find_actor, &args);
6103 }
6104
6105 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
6106 struct btrfs_root *root,
6107 struct inode *dir,
6108 const char *name, int name_len,
6109 u64 ref_objectid, u64 objectid,
6110 umode_t mode, u64 *index)
6111 {
6112 struct inode *inode;
6113 struct btrfs_inode_item *inode_item;
6114 struct btrfs_key *location;
6115 struct btrfs_path *path;
6116 struct btrfs_inode_ref *ref;
6117 struct btrfs_key key[2];
6118 u32 sizes[2];
6119 int nitems = name ? 2 : 1;
6120 unsigned long ptr;
6121 int ret;
6122
6123 path = btrfs_alloc_path();
6124 if (!path)
6125 return ERR_PTR(-ENOMEM);
6126
6127 inode = new_inode(root->fs_info->sb);
6128 if (!inode) {
6129 btrfs_free_path(path);
6130 return ERR_PTR(-ENOMEM);
6131 }
6132
6133 /*
6134 * O_TMPFILE, set link count to 0, so that after this point,
6135 * we fill in an inode item with the correct link count.
6136 */
6137 if (!name)
6138 set_nlink(inode, 0);
6139
6140 /*
6141 * we have to initialize this early, so we can reclaim the inode
6142 * number if we fail afterwards in this function.
6143 */
6144 inode->i_ino = objectid;
6145
6146 if (dir && name) {
6147 trace_btrfs_inode_request(dir);
6148
6149 ret = btrfs_set_inode_index(dir, index);
6150 if (ret) {
6151 btrfs_free_path(path);
6152 iput(inode);
6153 return ERR_PTR(ret);
6154 }
6155 } else if (dir) {
6156 *index = 0;
6157 }
6158 /*
6159 * index_cnt is ignored for everything but a dir,
6160 * btrfs_get_inode_index_count has an explanation for the magic
6161 * number
6162 */
6163 BTRFS_I(inode)->index_cnt = 2;
6164 BTRFS_I(inode)->dir_index = *index;
6165 BTRFS_I(inode)->root = root;
6166 BTRFS_I(inode)->generation = trans->transid;
6167 inode->i_generation = BTRFS_I(inode)->generation;
6168
6169 /*
6170 * We could have gotten an inode number from somebody who was fsynced
6171 * and then removed in this same transaction, so let's just set full
6172 * sync since it will be a full sync anyway and this will blow away the
6173 * old info in the log.
6174 */
6175 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6176
6177 key[0].objectid = objectid;
6178 key[0].type = BTRFS_INODE_ITEM_KEY;
6179 key[0].offset = 0;
6180
6181 sizes[0] = sizeof(struct btrfs_inode_item);
6182
6183 if (name) {
6184 /*
6185 * Start new inodes with an inode_ref. This is slightly more
6186 * efficient for small numbers of hard links since they will
6187 * be packed into one item. Extended refs will kick in if we
6188 * add more hard links than can fit in the ref item.
6189 */
6190 key[1].objectid = objectid;
6191 key[1].type = BTRFS_INODE_REF_KEY;
6192 key[1].offset = ref_objectid;
6193
6194 sizes[1] = name_len + sizeof(*ref);
6195 }
6196
6197 location = &BTRFS_I(inode)->location;
6198 location->objectid = objectid;
6199 location->offset = 0;
6200 location->type = BTRFS_INODE_ITEM_KEY;
6201
6202 ret = btrfs_insert_inode_locked(inode);
6203 if (ret < 0)
6204 goto fail;
6205
6206 path->leave_spinning = 1;
6207 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6208 if (ret != 0)
6209 goto fail_unlock;
6210
6211 inode_init_owner(inode, dir, mode);
6212 inode_set_bytes(inode, 0);
6213
6214 inode->i_mtime = current_fs_time(inode->i_sb);
6215 inode->i_atime = inode->i_mtime;
6216 inode->i_ctime = inode->i_mtime;
6217 BTRFS_I(inode)->i_otime = inode->i_mtime;
6218
6219 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6220 struct btrfs_inode_item);
6221 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
6222 sizeof(*inode_item));
6223 fill_inode_item(trans, path->nodes[0], inode_item, inode);
6224
6225 if (name) {
6226 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6227 struct btrfs_inode_ref);
6228 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6229 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6230 ptr = (unsigned long)(ref + 1);
6231 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6232 }
6233
6234 btrfs_mark_buffer_dirty(path->nodes[0]);
6235 btrfs_free_path(path);
6236
6237 btrfs_inherit_iflags(inode, dir);
6238
6239 if (S_ISREG(mode)) {
6240 if (btrfs_test_opt(root, NODATASUM))
6241 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6242 if (btrfs_test_opt(root, NODATACOW))
6243 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6244 BTRFS_INODE_NODATASUM;
6245 }
6246
6247 inode_tree_add(inode);
6248
6249 trace_btrfs_inode_new(inode);
6250 btrfs_set_inode_last_trans(trans, inode);
6251
6252 btrfs_update_root_times(trans, root);
6253
6254 ret = btrfs_inode_inherit_props(trans, inode, dir);
6255 if (ret)
6256 btrfs_err(root->fs_info,
6257 "error inheriting props for ino %llu (root %llu): %d",
6258 btrfs_ino(inode), root->root_key.objectid, ret);
6259
6260 return inode;
6261
6262 fail_unlock:
6263 unlock_new_inode(inode);
6264 fail:
6265 if (dir && name)
6266 BTRFS_I(dir)->index_cnt--;
6267 btrfs_free_path(path);
6268 iput(inode);
6269 return ERR_PTR(ret);
6270 }
6271
6272 static inline u8 btrfs_inode_type(struct inode *inode)
6273 {
6274 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
6275 }
6276
6277 /*
6278 * utility function to add 'inode' into 'parent_inode' with
6279 * a give name and a given sequence number.
6280 * if 'add_backref' is true, also insert a backref from the
6281 * inode to the parent directory.
6282 */
6283 int btrfs_add_link(struct btrfs_trans_handle *trans,
6284 struct inode *parent_inode, struct inode *inode,
6285 const char *name, int name_len, int add_backref, u64 index)
6286 {
6287 int ret = 0;
6288 struct btrfs_key key;
6289 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
6290 u64 ino = btrfs_ino(inode);
6291 u64 parent_ino = btrfs_ino(parent_inode);
6292
6293 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6294 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
6295 } else {
6296 key.objectid = ino;
6297 key.type = BTRFS_INODE_ITEM_KEY;
6298 key.offset = 0;
6299 }
6300
6301 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6302 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
6303 key.objectid, root->root_key.objectid,
6304 parent_ino, index, name, name_len);
6305 } else if (add_backref) {
6306 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6307 parent_ino, index);
6308 }
6309
6310 /* Nothing to clean up yet */
6311 if (ret)
6312 return ret;
6313
6314 ret = btrfs_insert_dir_item(trans, root, name, name_len,
6315 parent_inode, &key,
6316 btrfs_inode_type(inode), index);
6317 if (ret == -EEXIST || ret == -EOVERFLOW)
6318 goto fail_dir_item;
6319 else if (ret) {
6320 btrfs_abort_transaction(trans, root, ret);
6321 return ret;
6322 }
6323
6324 btrfs_i_size_write(parent_inode, parent_inode->i_size +
6325 name_len * 2);
6326 inode_inc_iversion(parent_inode);
6327 parent_inode->i_mtime = parent_inode->i_ctime =
6328 current_fs_time(parent_inode->i_sb);
6329 ret = btrfs_update_inode(trans, root, parent_inode);
6330 if (ret)
6331 btrfs_abort_transaction(trans, root, ret);
6332 return ret;
6333
6334 fail_dir_item:
6335 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6336 u64 local_index;
6337 int err;
6338 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
6339 key.objectid, root->root_key.objectid,
6340 parent_ino, &local_index, name, name_len);
6341
6342 } else if (add_backref) {
6343 u64 local_index;
6344 int err;
6345
6346 err = btrfs_del_inode_ref(trans, root, name, name_len,
6347 ino, parent_ino, &local_index);
6348 }
6349 return ret;
6350 }
6351
6352 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6353 struct inode *dir, struct dentry *dentry,
6354 struct inode *inode, int backref, u64 index)
6355 {
6356 int err = btrfs_add_link(trans, dir, inode,
6357 dentry->d_name.name, dentry->d_name.len,
6358 backref, index);
6359 if (err > 0)
6360 err = -EEXIST;
6361 return err;
6362 }
6363
6364 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6365 umode_t mode, dev_t rdev)
6366 {
6367 struct btrfs_trans_handle *trans;
6368 struct btrfs_root *root = BTRFS_I(dir)->root;
6369 struct inode *inode = NULL;
6370 int err;
6371 int drop_inode = 0;
6372 u64 objectid;
6373 u64 index = 0;
6374
6375 /*
6376 * 2 for inode item and ref
6377 * 2 for dir items
6378 * 1 for xattr if selinux is on
6379 */
6380 trans = btrfs_start_transaction(root, 5);
6381 if (IS_ERR(trans))
6382 return PTR_ERR(trans);
6383
6384 err = btrfs_find_free_ino(root, &objectid);
6385 if (err)
6386 goto out_unlock;
6387
6388 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6389 dentry->d_name.len, btrfs_ino(dir), objectid,
6390 mode, &index);
6391 if (IS_ERR(inode)) {
6392 err = PTR_ERR(inode);
6393 goto out_unlock;
6394 }
6395
6396 /*
6397 * If the active LSM wants to access the inode during
6398 * d_instantiate it needs these. Smack checks to see
6399 * if the filesystem supports xattrs by looking at the
6400 * ops vector.
6401 */
6402 inode->i_op = &btrfs_special_inode_operations;
6403 init_special_inode(inode, inode->i_mode, rdev);
6404
6405 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6406 if (err)
6407 goto out_unlock_inode;
6408
6409 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6410 if (err) {
6411 goto out_unlock_inode;
6412 } else {
6413 btrfs_update_inode(trans, root, inode);
6414 unlock_new_inode(inode);
6415 d_instantiate(dentry, inode);
6416 }
6417
6418 out_unlock:
6419 btrfs_end_transaction(trans, root);
6420 btrfs_balance_delayed_items(root);
6421 btrfs_btree_balance_dirty(root);
6422 if (drop_inode) {
6423 inode_dec_link_count(inode);
6424 iput(inode);
6425 }
6426 return err;
6427
6428 out_unlock_inode:
6429 drop_inode = 1;
6430 unlock_new_inode(inode);
6431 goto out_unlock;
6432
6433 }
6434
6435 static int btrfs_create(struct inode *dir, struct dentry *dentry,
6436 umode_t mode, bool excl)
6437 {
6438 struct btrfs_trans_handle *trans;
6439 struct btrfs_root *root = BTRFS_I(dir)->root;
6440 struct inode *inode = NULL;
6441 int drop_inode_on_err = 0;
6442 int err;
6443 u64 objectid;
6444 u64 index = 0;
6445
6446 /*
6447 * 2 for inode item and ref
6448 * 2 for dir items
6449 * 1 for xattr if selinux is on
6450 */
6451 trans = btrfs_start_transaction(root, 5);
6452 if (IS_ERR(trans))
6453 return PTR_ERR(trans);
6454
6455 err = btrfs_find_free_ino(root, &objectid);
6456 if (err)
6457 goto out_unlock;
6458
6459 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6460 dentry->d_name.len, btrfs_ino(dir), objectid,
6461 mode, &index);
6462 if (IS_ERR(inode)) {
6463 err = PTR_ERR(inode);
6464 goto out_unlock;
6465 }
6466 drop_inode_on_err = 1;
6467 /*
6468 * If the active LSM wants to access the inode during
6469 * d_instantiate it needs these. Smack checks to see
6470 * if the filesystem supports xattrs by looking at the
6471 * ops vector.
6472 */
6473 inode->i_fop = &btrfs_file_operations;
6474 inode->i_op = &btrfs_file_inode_operations;
6475 inode->i_mapping->a_ops = &btrfs_aops;
6476
6477 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6478 if (err)
6479 goto out_unlock_inode;
6480
6481 err = btrfs_update_inode(trans, root, inode);
6482 if (err)
6483 goto out_unlock_inode;
6484
6485 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6486 if (err)
6487 goto out_unlock_inode;
6488
6489 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6490 unlock_new_inode(inode);
6491 d_instantiate(dentry, inode);
6492
6493 out_unlock:
6494 btrfs_end_transaction(trans, root);
6495 if (err && drop_inode_on_err) {
6496 inode_dec_link_count(inode);
6497 iput(inode);
6498 }
6499 btrfs_balance_delayed_items(root);
6500 btrfs_btree_balance_dirty(root);
6501 return err;
6502
6503 out_unlock_inode:
6504 unlock_new_inode(inode);
6505 goto out_unlock;
6506
6507 }
6508
6509 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6510 struct dentry *dentry)
6511 {
6512 struct btrfs_trans_handle *trans = NULL;
6513 struct btrfs_root *root = BTRFS_I(dir)->root;
6514 struct inode *inode = d_inode(old_dentry);
6515 u64 index;
6516 int err;
6517 int drop_inode = 0;
6518
6519 /* do not allow sys_link's with other subvols of the same device */
6520 if (root->objectid != BTRFS_I(inode)->root->objectid)
6521 return -EXDEV;
6522
6523 if (inode->i_nlink >= BTRFS_LINK_MAX)
6524 return -EMLINK;
6525
6526 err = btrfs_set_inode_index(dir, &index);
6527 if (err)
6528 goto fail;
6529
6530 /*
6531 * 2 items for inode and inode ref
6532 * 2 items for dir items
6533 * 1 item for parent inode
6534 */
6535 trans = btrfs_start_transaction(root, 5);
6536 if (IS_ERR(trans)) {
6537 err = PTR_ERR(trans);
6538 trans = NULL;
6539 goto fail;
6540 }
6541
6542 /* There are several dir indexes for this inode, clear the cache. */
6543 BTRFS_I(inode)->dir_index = 0ULL;
6544 inc_nlink(inode);
6545 inode_inc_iversion(inode);
6546 inode->i_ctime = current_fs_time(inode->i_sb);
6547 ihold(inode);
6548 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6549
6550 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
6551
6552 if (err) {
6553 drop_inode = 1;
6554 } else {
6555 struct dentry *parent = dentry->d_parent;
6556 err = btrfs_update_inode(trans, root, inode);
6557 if (err)
6558 goto fail;
6559 if (inode->i_nlink == 1) {
6560 /*
6561 * If new hard link count is 1, it's a file created
6562 * with open(2) O_TMPFILE flag.
6563 */
6564 err = btrfs_orphan_del(trans, inode);
6565 if (err)
6566 goto fail;
6567 }
6568 d_instantiate(dentry, inode);
6569 btrfs_log_new_name(trans, inode, NULL, parent);
6570 }
6571
6572 btrfs_balance_delayed_items(root);
6573 fail:
6574 if (trans)
6575 btrfs_end_transaction(trans, root);
6576 if (drop_inode) {
6577 inode_dec_link_count(inode);
6578 iput(inode);
6579 }
6580 btrfs_btree_balance_dirty(root);
6581 return err;
6582 }
6583
6584 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6585 {
6586 struct inode *inode = NULL;
6587 struct btrfs_trans_handle *trans;
6588 struct btrfs_root *root = BTRFS_I(dir)->root;
6589 int err = 0;
6590 int drop_on_err = 0;
6591 u64 objectid = 0;
6592 u64 index = 0;
6593
6594 /*
6595 * 2 items for inode and ref
6596 * 2 items for dir items
6597 * 1 for xattr if selinux is on
6598 */
6599 trans = btrfs_start_transaction(root, 5);
6600 if (IS_ERR(trans))
6601 return PTR_ERR(trans);
6602
6603 err = btrfs_find_free_ino(root, &objectid);
6604 if (err)
6605 goto out_fail;
6606
6607 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6608 dentry->d_name.len, btrfs_ino(dir), objectid,
6609 S_IFDIR | mode, &index);
6610 if (IS_ERR(inode)) {
6611 err = PTR_ERR(inode);
6612 goto out_fail;
6613 }
6614
6615 drop_on_err = 1;
6616 /* these must be set before we unlock the inode */
6617 inode->i_op = &btrfs_dir_inode_operations;
6618 inode->i_fop = &btrfs_dir_file_operations;
6619
6620 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6621 if (err)
6622 goto out_fail_inode;
6623
6624 btrfs_i_size_write(inode, 0);
6625 err = btrfs_update_inode(trans, root, inode);
6626 if (err)
6627 goto out_fail_inode;
6628
6629 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
6630 dentry->d_name.len, 0, index);
6631 if (err)
6632 goto out_fail_inode;
6633
6634 d_instantiate(dentry, inode);
6635 /*
6636 * mkdir is special. We're unlocking after we call d_instantiate
6637 * to avoid a race with nfsd calling d_instantiate.
6638 */
6639 unlock_new_inode(inode);
6640 drop_on_err = 0;
6641
6642 out_fail:
6643 btrfs_end_transaction(trans, root);
6644 if (drop_on_err) {
6645 inode_dec_link_count(inode);
6646 iput(inode);
6647 }
6648 btrfs_balance_delayed_items(root);
6649 btrfs_btree_balance_dirty(root);
6650 return err;
6651
6652 out_fail_inode:
6653 unlock_new_inode(inode);
6654 goto out_fail;
6655 }
6656
6657 /* Find next extent map of a given extent map, caller needs to ensure locks */
6658 static struct extent_map *next_extent_map(struct extent_map *em)
6659 {
6660 struct rb_node *next;
6661
6662 next = rb_next(&em->rb_node);
6663 if (!next)
6664 return NULL;
6665 return container_of(next, struct extent_map, rb_node);
6666 }
6667
6668 static struct extent_map *prev_extent_map(struct extent_map *em)
6669 {
6670 struct rb_node *prev;
6671
6672 prev = rb_prev(&em->rb_node);
6673 if (!prev)
6674 return NULL;
6675 return container_of(prev, struct extent_map, rb_node);
6676 }
6677
6678 /* helper for btfs_get_extent. Given an existing extent in the tree,
6679 * the existing extent is the nearest extent to map_start,
6680 * and an extent that you want to insert, deal with overlap and insert
6681 * the best fitted new extent into the tree.
6682 */
6683 static int merge_extent_mapping(struct extent_map_tree *em_tree,
6684 struct extent_map *existing,
6685 struct extent_map *em,
6686 u64 map_start)
6687 {
6688 struct extent_map *prev;
6689 struct extent_map *next;
6690 u64 start;
6691 u64 end;
6692 u64 start_diff;
6693
6694 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
6695
6696 if (existing->start > map_start) {
6697 next = existing;
6698 prev = prev_extent_map(next);
6699 } else {
6700 prev = existing;
6701 next = next_extent_map(prev);
6702 }
6703
6704 start = prev ? extent_map_end(prev) : em->start;
6705 start = max_t(u64, start, em->start);
6706 end = next ? next->start : extent_map_end(em);
6707 end = min_t(u64, end, extent_map_end(em));
6708 start_diff = start - em->start;
6709 em->start = start;
6710 em->len = end - start;
6711 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
6712 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
6713 em->block_start += start_diff;
6714 em->block_len -= start_diff;
6715 }
6716 return add_extent_mapping(em_tree, em, 0);
6717 }
6718
6719 static noinline int uncompress_inline(struct btrfs_path *path,
6720 struct page *page,
6721 size_t pg_offset, u64 extent_offset,
6722 struct btrfs_file_extent_item *item)
6723 {
6724 int ret;
6725 struct extent_buffer *leaf = path->nodes[0];
6726 char *tmp;
6727 size_t max_size;
6728 unsigned long inline_size;
6729 unsigned long ptr;
6730 int compress_type;
6731
6732 WARN_ON(pg_offset != 0);
6733 compress_type = btrfs_file_extent_compression(leaf, item);
6734 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6735 inline_size = btrfs_file_extent_inline_item_len(leaf,
6736 btrfs_item_nr(path->slots[0]));
6737 tmp = kmalloc(inline_size, GFP_NOFS);
6738 if (!tmp)
6739 return -ENOMEM;
6740 ptr = btrfs_file_extent_inline_start(item);
6741
6742 read_extent_buffer(leaf, tmp, ptr, inline_size);
6743
6744 max_size = min_t(unsigned long, PAGE_SIZE, max_size);
6745 ret = btrfs_decompress(compress_type, tmp, page,
6746 extent_offset, inline_size, max_size);
6747 kfree(tmp);
6748 return ret;
6749 }
6750
6751 /*
6752 * a bit scary, this does extent mapping from logical file offset to the disk.
6753 * the ugly parts come from merging extents from the disk with the in-ram
6754 * representation. This gets more complex because of the data=ordered code,
6755 * where the in-ram extents might be locked pending data=ordered completion.
6756 *
6757 * This also copies inline extents directly into the page.
6758 */
6759
6760 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
6761 size_t pg_offset, u64 start, u64 len,
6762 int create)
6763 {
6764 int ret;
6765 int err = 0;
6766 u64 extent_start = 0;
6767 u64 extent_end = 0;
6768 u64 objectid = btrfs_ino(inode);
6769 u32 found_type;
6770 struct btrfs_path *path = NULL;
6771 struct btrfs_root *root = BTRFS_I(inode)->root;
6772 struct btrfs_file_extent_item *item;
6773 struct extent_buffer *leaf;
6774 struct btrfs_key found_key;
6775 struct extent_map *em = NULL;
6776 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
6777 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6778 struct btrfs_trans_handle *trans = NULL;
6779 const bool new_inline = !page || create;
6780
6781 again:
6782 read_lock(&em_tree->lock);
6783 em = lookup_extent_mapping(em_tree, start, len);
6784 if (em)
6785 em->bdev = root->fs_info->fs_devices->latest_bdev;
6786 read_unlock(&em_tree->lock);
6787
6788 if (em) {
6789 if (em->start > start || em->start + em->len <= start)
6790 free_extent_map(em);
6791 else if (em->block_start == EXTENT_MAP_INLINE && page)
6792 free_extent_map(em);
6793 else
6794 goto out;
6795 }
6796 em = alloc_extent_map();
6797 if (!em) {
6798 err = -ENOMEM;
6799 goto out;
6800 }
6801 em->bdev = root->fs_info->fs_devices->latest_bdev;
6802 em->start = EXTENT_MAP_HOLE;
6803 em->orig_start = EXTENT_MAP_HOLE;
6804 em->len = (u64)-1;
6805 em->block_len = (u64)-1;
6806
6807 if (!path) {
6808 path = btrfs_alloc_path();
6809 if (!path) {
6810 err = -ENOMEM;
6811 goto out;
6812 }
6813 /*
6814 * Chances are we'll be called again, so go ahead and do
6815 * readahead
6816 */
6817 path->reada = READA_FORWARD;
6818 }
6819
6820 ret = btrfs_lookup_file_extent(trans, root, path,
6821 objectid, start, trans != NULL);
6822 if (ret < 0) {
6823 err = ret;
6824 goto out;
6825 }
6826
6827 if (ret != 0) {
6828 if (path->slots[0] == 0)
6829 goto not_found;
6830 path->slots[0]--;
6831 }
6832
6833 leaf = path->nodes[0];
6834 item = btrfs_item_ptr(leaf, path->slots[0],
6835 struct btrfs_file_extent_item);
6836 /* are we inside the extent that was found? */
6837 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6838 found_type = found_key.type;
6839 if (found_key.objectid != objectid ||
6840 found_type != BTRFS_EXTENT_DATA_KEY) {
6841 /*
6842 * If we backup past the first extent we want to move forward
6843 * and see if there is an extent in front of us, otherwise we'll
6844 * say there is a hole for our whole search range which can
6845 * cause problems.
6846 */
6847 extent_end = start;
6848 goto next;
6849 }
6850
6851 found_type = btrfs_file_extent_type(leaf, item);
6852 extent_start = found_key.offset;
6853 if (found_type == BTRFS_FILE_EXTENT_REG ||
6854 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6855 extent_end = extent_start +
6856 btrfs_file_extent_num_bytes(leaf, item);
6857 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6858 size_t size;
6859 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6860 extent_end = ALIGN(extent_start + size, root->sectorsize);
6861 }
6862 next:
6863 if (start >= extent_end) {
6864 path->slots[0]++;
6865 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6866 ret = btrfs_next_leaf(root, path);
6867 if (ret < 0) {
6868 err = ret;
6869 goto out;
6870 }
6871 if (ret > 0)
6872 goto not_found;
6873 leaf = path->nodes[0];
6874 }
6875 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6876 if (found_key.objectid != objectid ||
6877 found_key.type != BTRFS_EXTENT_DATA_KEY)
6878 goto not_found;
6879 if (start + len <= found_key.offset)
6880 goto not_found;
6881 if (start > found_key.offset)
6882 goto next;
6883 em->start = start;
6884 em->orig_start = start;
6885 em->len = found_key.offset - start;
6886 goto not_found_em;
6887 }
6888
6889 btrfs_extent_item_to_extent_map(inode, path, item, new_inline, em);
6890
6891 if (found_type == BTRFS_FILE_EXTENT_REG ||
6892 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6893 goto insert;
6894 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6895 unsigned long ptr;
6896 char *map;
6897 size_t size;
6898 size_t extent_offset;
6899 size_t copy_size;
6900
6901 if (new_inline)
6902 goto out;
6903
6904 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6905 extent_offset = page_offset(page) + pg_offset - extent_start;
6906 copy_size = min_t(u64, PAGE_SIZE - pg_offset,
6907 size - extent_offset);
6908 em->start = extent_start + extent_offset;
6909 em->len = ALIGN(copy_size, root->sectorsize);
6910 em->orig_block_len = em->len;
6911 em->orig_start = em->start;
6912 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6913 if (create == 0 && !PageUptodate(page)) {
6914 if (btrfs_file_extent_compression(leaf, item) !=
6915 BTRFS_COMPRESS_NONE) {
6916 ret = uncompress_inline(path, page, pg_offset,
6917 extent_offset, item);
6918 if (ret) {
6919 err = ret;
6920 goto out;
6921 }
6922 } else {
6923 map = kmap(page);
6924 read_extent_buffer(leaf, map + pg_offset, ptr,
6925 copy_size);
6926 if (pg_offset + copy_size < PAGE_SIZE) {
6927 memset(map + pg_offset + copy_size, 0,
6928 PAGE_SIZE - pg_offset -
6929 copy_size);
6930 }
6931 kunmap(page);
6932 }
6933 flush_dcache_page(page);
6934 } else if (create && PageUptodate(page)) {
6935 BUG();
6936 if (!trans) {
6937 kunmap(page);
6938 free_extent_map(em);
6939 em = NULL;
6940
6941 btrfs_release_path(path);
6942 trans = btrfs_join_transaction(root);
6943
6944 if (IS_ERR(trans))
6945 return ERR_CAST(trans);
6946 goto again;
6947 }
6948 map = kmap(page);
6949 write_extent_buffer(leaf, map + pg_offset, ptr,
6950 copy_size);
6951 kunmap(page);
6952 btrfs_mark_buffer_dirty(leaf);
6953 }
6954 set_extent_uptodate(io_tree, em->start,
6955 extent_map_end(em) - 1, NULL, GFP_NOFS);
6956 goto insert;
6957 }
6958 not_found:
6959 em->start = start;
6960 em->orig_start = start;
6961 em->len = len;
6962 not_found_em:
6963 em->block_start = EXTENT_MAP_HOLE;
6964 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
6965 insert:
6966 btrfs_release_path(path);
6967 if (em->start > start || extent_map_end(em) <= start) {
6968 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
6969 em->start, em->len, start, len);
6970 err = -EIO;
6971 goto out;
6972 }
6973
6974 err = 0;
6975 write_lock(&em_tree->lock);
6976 ret = add_extent_mapping(em_tree, em, 0);
6977 /* it is possible that someone inserted the extent into the tree
6978 * while we had the lock dropped. It is also possible that
6979 * an overlapping map exists in the tree
6980 */
6981 if (ret == -EEXIST) {
6982 struct extent_map *existing;
6983
6984 ret = 0;
6985
6986 existing = search_extent_mapping(em_tree, start, len);
6987 /*
6988 * existing will always be non-NULL, since there must be
6989 * extent causing the -EEXIST.
6990 */
6991 if (existing->start == em->start &&
6992 extent_map_end(existing) == extent_map_end(em) &&
6993 em->block_start == existing->block_start) {
6994 /*
6995 * these two extents are the same, it happens
6996 * with inlines especially
6997 */
6998 free_extent_map(em);
6999 em = existing;
7000 err = 0;
7001
7002 } else if (start >= extent_map_end(existing) ||
7003 start <= existing->start) {
7004 /*
7005 * The existing extent map is the one nearest to
7006 * the [start, start + len) range which overlaps
7007 */
7008 err = merge_extent_mapping(em_tree, existing,
7009 em, start);
7010 free_extent_map(existing);
7011 if (err) {
7012 free_extent_map(em);
7013 em = NULL;
7014 }
7015 } else {
7016 free_extent_map(em);
7017 em = existing;
7018 err = 0;
7019 }
7020 }
7021 write_unlock(&em_tree->lock);
7022 out:
7023
7024 trace_btrfs_get_extent(root, em);
7025
7026 btrfs_free_path(path);
7027 if (trans) {
7028 ret = btrfs_end_transaction(trans, root);
7029 if (!err)
7030 err = ret;
7031 }
7032 if (err) {
7033 free_extent_map(em);
7034 return ERR_PTR(err);
7035 }
7036 BUG_ON(!em); /* Error is always set */
7037 return em;
7038 }
7039
7040 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
7041 size_t pg_offset, u64 start, u64 len,
7042 int create)
7043 {
7044 struct extent_map *em;
7045 struct extent_map *hole_em = NULL;
7046 u64 range_start = start;
7047 u64 end;
7048 u64 found;
7049 u64 found_end;
7050 int err = 0;
7051
7052 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
7053 if (IS_ERR(em))
7054 return em;
7055 if (em) {
7056 /*
7057 * if our em maps to
7058 * - a hole or
7059 * - a pre-alloc extent,
7060 * there might actually be delalloc bytes behind it.
7061 */
7062 if (em->block_start != EXTENT_MAP_HOLE &&
7063 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7064 return em;
7065 else
7066 hole_em = em;
7067 }
7068
7069 /* check to see if we've wrapped (len == -1 or similar) */
7070 end = start + len;
7071 if (end < start)
7072 end = (u64)-1;
7073 else
7074 end -= 1;
7075
7076 em = NULL;
7077
7078 /* ok, we didn't find anything, lets look for delalloc */
7079 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
7080 end, len, EXTENT_DELALLOC, 1);
7081 found_end = range_start + found;
7082 if (found_end < range_start)
7083 found_end = (u64)-1;
7084
7085 /*
7086 * we didn't find anything useful, return
7087 * the original results from get_extent()
7088 */
7089 if (range_start > end || found_end <= start) {
7090 em = hole_em;
7091 hole_em = NULL;
7092 goto out;
7093 }
7094
7095 /* adjust the range_start to make sure it doesn't
7096 * go backwards from the start they passed in
7097 */
7098 range_start = max(start, range_start);
7099 found = found_end - range_start;
7100
7101 if (found > 0) {
7102 u64 hole_start = start;
7103 u64 hole_len = len;
7104
7105 em = alloc_extent_map();
7106 if (!em) {
7107 err = -ENOMEM;
7108 goto out;
7109 }
7110 /*
7111 * when btrfs_get_extent can't find anything it
7112 * returns one huge hole
7113 *
7114 * make sure what it found really fits our range, and
7115 * adjust to make sure it is based on the start from
7116 * the caller
7117 */
7118 if (hole_em) {
7119 u64 calc_end = extent_map_end(hole_em);
7120
7121 if (calc_end <= start || (hole_em->start > end)) {
7122 free_extent_map(hole_em);
7123 hole_em = NULL;
7124 } else {
7125 hole_start = max(hole_em->start, start);
7126 hole_len = calc_end - hole_start;
7127 }
7128 }
7129 em->bdev = NULL;
7130 if (hole_em && range_start > hole_start) {
7131 /* our hole starts before our delalloc, so we
7132 * have to return just the parts of the hole
7133 * that go until the delalloc starts
7134 */
7135 em->len = min(hole_len,
7136 range_start - hole_start);
7137 em->start = hole_start;
7138 em->orig_start = hole_start;
7139 /*
7140 * don't adjust block start at all,
7141 * it is fixed at EXTENT_MAP_HOLE
7142 */
7143 em->block_start = hole_em->block_start;
7144 em->block_len = hole_len;
7145 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
7146 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7147 } else {
7148 em->start = range_start;
7149 em->len = found;
7150 em->orig_start = range_start;
7151 em->block_start = EXTENT_MAP_DELALLOC;
7152 em->block_len = found;
7153 }
7154 } else if (hole_em) {
7155 return hole_em;
7156 }
7157 out:
7158
7159 free_extent_map(hole_em);
7160 if (err) {
7161 free_extent_map(em);
7162 return ERR_PTR(err);
7163 }
7164 return em;
7165 }
7166
7167 static struct extent_map *btrfs_create_dio_extent(struct inode *inode,
7168 const u64 start,
7169 const u64 len,
7170 const u64 orig_start,
7171 const u64 block_start,
7172 const u64 block_len,
7173 const u64 orig_block_len,
7174 const u64 ram_bytes,
7175 const int type)
7176 {
7177 struct extent_map *em = NULL;
7178 int ret;
7179
7180 down_read(&BTRFS_I(inode)->dio_sem);
7181 if (type != BTRFS_ORDERED_NOCOW) {
7182 em = create_pinned_em(inode, start, len, orig_start,
7183 block_start, block_len, orig_block_len,
7184 ram_bytes, type);
7185 if (IS_ERR(em))
7186 goto out;
7187 }
7188 ret = btrfs_add_ordered_extent_dio(inode, start, block_start,
7189 len, block_len, type);
7190 if (ret) {
7191 if (em) {
7192 free_extent_map(em);
7193 btrfs_drop_extent_cache(inode, start,
7194 start + len - 1, 0);
7195 }
7196 em = ERR_PTR(ret);
7197 }
7198 out:
7199 up_read(&BTRFS_I(inode)->dio_sem);
7200
7201 return em;
7202 }
7203
7204 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7205 u64 start, u64 len)
7206 {
7207 struct btrfs_root *root = BTRFS_I(inode)->root;
7208 struct extent_map *em;
7209 struct btrfs_key ins;
7210 u64 alloc_hint;
7211 int ret;
7212
7213 alloc_hint = get_extent_allocation_hint(inode, start, len);
7214 ret = btrfs_reserve_extent(root, len, root->sectorsize, 0,
7215 alloc_hint, &ins, 1, 1);
7216 if (ret)
7217 return ERR_PTR(ret);
7218
7219 em = btrfs_create_dio_extent(inode, start, ins.offset, start,
7220 ins.objectid, ins.offset, ins.offset,
7221 ins.offset, 0);
7222 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
7223 if (IS_ERR(em))
7224 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
7225
7226 return em;
7227 }
7228
7229 /*
7230 * returns 1 when the nocow is safe, < 1 on error, 0 if the
7231 * block must be cow'd
7232 */
7233 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7234 u64 *orig_start, u64 *orig_block_len,
7235 u64 *ram_bytes)
7236 {
7237 struct btrfs_trans_handle *trans;
7238 struct btrfs_path *path;
7239 int ret;
7240 struct extent_buffer *leaf;
7241 struct btrfs_root *root = BTRFS_I(inode)->root;
7242 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7243 struct btrfs_file_extent_item *fi;
7244 struct btrfs_key key;
7245 u64 disk_bytenr;
7246 u64 backref_offset;
7247 u64 extent_end;
7248 u64 num_bytes;
7249 int slot;
7250 int found_type;
7251 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7252
7253 path = btrfs_alloc_path();
7254 if (!path)
7255 return -ENOMEM;
7256
7257 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
7258 offset, 0);
7259 if (ret < 0)
7260 goto out;
7261
7262 slot = path->slots[0];
7263 if (ret == 1) {
7264 if (slot == 0) {
7265 /* can't find the item, must cow */
7266 ret = 0;
7267 goto out;
7268 }
7269 slot--;
7270 }
7271 ret = 0;
7272 leaf = path->nodes[0];
7273 btrfs_item_key_to_cpu(leaf, &key, slot);
7274 if (key.objectid != btrfs_ino(inode) ||
7275 key.type != BTRFS_EXTENT_DATA_KEY) {
7276 /* not our file or wrong item type, must cow */
7277 goto out;
7278 }
7279
7280 if (key.offset > offset) {
7281 /* Wrong offset, must cow */
7282 goto out;
7283 }
7284
7285 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7286 found_type = btrfs_file_extent_type(leaf, fi);
7287 if (found_type != BTRFS_FILE_EXTENT_REG &&
7288 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7289 /* not a regular extent, must cow */
7290 goto out;
7291 }
7292
7293 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7294 goto out;
7295
7296 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7297 if (extent_end <= offset)
7298 goto out;
7299
7300 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7301 if (disk_bytenr == 0)
7302 goto out;
7303
7304 if (btrfs_file_extent_compression(leaf, fi) ||
7305 btrfs_file_extent_encryption(leaf, fi) ||
7306 btrfs_file_extent_other_encoding(leaf, fi))
7307 goto out;
7308
7309 backref_offset = btrfs_file_extent_offset(leaf, fi);
7310
7311 if (orig_start) {
7312 *orig_start = key.offset - backref_offset;
7313 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7314 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7315 }
7316
7317 if (btrfs_extent_readonly(root, disk_bytenr))
7318 goto out;
7319
7320 num_bytes = min(offset + *len, extent_end) - offset;
7321 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7322 u64 range_end;
7323
7324 range_end = round_up(offset + num_bytes, root->sectorsize) - 1;
7325 ret = test_range_bit(io_tree, offset, range_end,
7326 EXTENT_DELALLOC, 0, NULL);
7327 if (ret) {
7328 ret = -EAGAIN;
7329 goto out;
7330 }
7331 }
7332
7333 btrfs_release_path(path);
7334
7335 /*
7336 * look for other files referencing this extent, if we
7337 * find any we must cow
7338 */
7339 trans = btrfs_join_transaction(root);
7340 if (IS_ERR(trans)) {
7341 ret = 0;
7342 goto out;
7343 }
7344
7345 ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
7346 key.offset - backref_offset, disk_bytenr);
7347 btrfs_end_transaction(trans, root);
7348 if (ret) {
7349 ret = 0;
7350 goto out;
7351 }
7352
7353 /*
7354 * adjust disk_bytenr and num_bytes to cover just the bytes
7355 * in this extent we are about to write. If there
7356 * are any csums in that range we have to cow in order
7357 * to keep the csums correct
7358 */
7359 disk_bytenr += backref_offset;
7360 disk_bytenr += offset - key.offset;
7361 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
7362 goto out;
7363 /*
7364 * all of the above have passed, it is safe to overwrite this extent
7365 * without cow
7366 */
7367 *len = num_bytes;
7368 ret = 1;
7369 out:
7370 btrfs_free_path(path);
7371 return ret;
7372 }
7373
7374 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
7375 {
7376 struct radix_tree_root *root = &inode->i_mapping->page_tree;
7377 int found = false;
7378 void **pagep = NULL;
7379 struct page *page = NULL;
7380 int start_idx;
7381 int end_idx;
7382
7383 start_idx = start >> PAGE_SHIFT;
7384
7385 /*
7386 * end is the last byte in the last page. end == start is legal
7387 */
7388 end_idx = end >> PAGE_SHIFT;
7389
7390 rcu_read_lock();
7391
7392 /* Most of the code in this while loop is lifted from
7393 * find_get_page. It's been modified to begin searching from a
7394 * page and return just the first page found in that range. If the
7395 * found idx is less than or equal to the end idx then we know that
7396 * a page exists. If no pages are found or if those pages are
7397 * outside of the range then we're fine (yay!) */
7398 while (page == NULL &&
7399 radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
7400 page = radix_tree_deref_slot(pagep);
7401 if (unlikely(!page))
7402 break;
7403
7404 if (radix_tree_exception(page)) {
7405 if (radix_tree_deref_retry(page)) {
7406 page = NULL;
7407 continue;
7408 }
7409 /*
7410 * Otherwise, shmem/tmpfs must be storing a swap entry
7411 * here as an exceptional entry: so return it without
7412 * attempting to raise page count.
7413 */
7414 page = NULL;
7415 break; /* TODO: Is this relevant for this use case? */
7416 }
7417
7418 if (!page_cache_get_speculative(page)) {
7419 page = NULL;
7420 continue;
7421 }
7422
7423 /*
7424 * Has the page moved?
7425 * This is part of the lockless pagecache protocol. See
7426 * include/linux/pagemap.h for details.
7427 */
7428 if (unlikely(page != *pagep)) {
7429 put_page(page);
7430 page = NULL;
7431 }
7432 }
7433
7434 if (page) {
7435 if (page->index <= end_idx)
7436 found = true;
7437 put_page(page);
7438 }
7439
7440 rcu_read_unlock();
7441 return found;
7442 }
7443
7444 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7445 struct extent_state **cached_state, int writing)
7446 {
7447 struct btrfs_ordered_extent *ordered;
7448 int ret = 0;
7449
7450 while (1) {
7451 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7452 cached_state);
7453 /*
7454 * We're concerned with the entire range that we're going to be
7455 * doing DIO to, so we need to make sure there's no ordered
7456 * extents in this range.
7457 */
7458 ordered = btrfs_lookup_ordered_range(inode, lockstart,
7459 lockend - lockstart + 1);
7460
7461 /*
7462 * We need to make sure there are no buffered pages in this
7463 * range either, we could have raced between the invalidate in
7464 * generic_file_direct_write and locking the extent. The
7465 * invalidate needs to happen so that reads after a write do not
7466 * get stale data.
7467 */
7468 if (!ordered &&
7469 (!writing ||
7470 !btrfs_page_exists_in_range(inode, lockstart, lockend)))
7471 break;
7472
7473 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7474 cached_state, GFP_NOFS);
7475
7476 if (ordered) {
7477 /*
7478 * If we are doing a DIO read and the ordered extent we
7479 * found is for a buffered write, we can not wait for it
7480 * to complete and retry, because if we do so we can
7481 * deadlock with concurrent buffered writes on page
7482 * locks. This happens only if our DIO read covers more
7483 * than one extent map, if at this point has already
7484 * created an ordered extent for a previous extent map
7485 * and locked its range in the inode's io tree, and a
7486 * concurrent write against that previous extent map's
7487 * range and this range started (we unlock the ranges
7488 * in the io tree only when the bios complete and
7489 * buffered writes always lock pages before attempting
7490 * to lock range in the io tree).
7491 */
7492 if (writing ||
7493 test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags))
7494 btrfs_start_ordered_extent(inode, ordered, 1);
7495 else
7496 ret = -ENOTBLK;
7497 btrfs_put_ordered_extent(ordered);
7498 } else {
7499 /*
7500 * We could trigger writeback for this range (and wait
7501 * for it to complete) and then invalidate the pages for
7502 * this range (through invalidate_inode_pages2_range()),
7503 * but that can lead us to a deadlock with a concurrent
7504 * call to readpages() (a buffered read or a defrag call
7505 * triggered a readahead) on a page lock due to an
7506 * ordered dio extent we created before but did not have
7507 * yet a corresponding bio submitted (whence it can not
7508 * complete), which makes readpages() wait for that
7509 * ordered extent to complete while holding a lock on
7510 * that page.
7511 */
7512 ret = -ENOTBLK;
7513 }
7514
7515 if (ret)
7516 break;
7517
7518 cond_resched();
7519 }
7520
7521 return ret;
7522 }
7523
7524 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
7525 u64 len, u64 orig_start,
7526 u64 block_start, u64 block_len,
7527 u64 orig_block_len, u64 ram_bytes,
7528 int type)
7529 {
7530 struct extent_map_tree *em_tree;
7531 struct extent_map *em;
7532 struct btrfs_root *root = BTRFS_I(inode)->root;
7533 int ret;
7534
7535 em_tree = &BTRFS_I(inode)->extent_tree;
7536 em = alloc_extent_map();
7537 if (!em)
7538 return ERR_PTR(-ENOMEM);
7539
7540 em->start = start;
7541 em->orig_start = orig_start;
7542 em->mod_start = start;
7543 em->mod_len = len;
7544 em->len = len;
7545 em->block_len = block_len;
7546 em->block_start = block_start;
7547 em->bdev = root->fs_info->fs_devices->latest_bdev;
7548 em->orig_block_len = orig_block_len;
7549 em->ram_bytes = ram_bytes;
7550 em->generation = -1;
7551 set_bit(EXTENT_FLAG_PINNED, &em->flags);
7552 if (type == BTRFS_ORDERED_PREALLOC)
7553 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7554
7555 do {
7556 btrfs_drop_extent_cache(inode, em->start,
7557 em->start + em->len - 1, 0);
7558 write_lock(&em_tree->lock);
7559 ret = add_extent_mapping(em_tree, em, 1);
7560 write_unlock(&em_tree->lock);
7561 } while (ret == -EEXIST);
7562
7563 if (ret) {
7564 free_extent_map(em);
7565 return ERR_PTR(ret);
7566 }
7567
7568 return em;
7569 }
7570
7571 static void adjust_dio_outstanding_extents(struct inode *inode,
7572 struct btrfs_dio_data *dio_data,
7573 const u64 len)
7574 {
7575 unsigned num_extents;
7576
7577 num_extents = (unsigned) div64_u64(len + BTRFS_MAX_EXTENT_SIZE - 1,
7578 BTRFS_MAX_EXTENT_SIZE);
7579 /*
7580 * If we have an outstanding_extents count still set then we're
7581 * within our reservation, otherwise we need to adjust our inode
7582 * counter appropriately.
7583 */
7584 if (dio_data->outstanding_extents) {
7585 dio_data->outstanding_extents -= num_extents;
7586 } else {
7587 spin_lock(&BTRFS_I(inode)->lock);
7588 BTRFS_I(inode)->outstanding_extents += num_extents;
7589 spin_unlock(&BTRFS_I(inode)->lock);
7590 }
7591 }
7592
7593 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7594 struct buffer_head *bh_result, int create)
7595 {
7596 struct extent_map *em;
7597 struct btrfs_root *root = BTRFS_I(inode)->root;
7598 struct extent_state *cached_state = NULL;
7599 struct btrfs_dio_data *dio_data = NULL;
7600 u64 start = iblock << inode->i_blkbits;
7601 u64 lockstart, lockend;
7602 u64 len = bh_result->b_size;
7603 int unlock_bits = EXTENT_LOCKED;
7604 int ret = 0;
7605
7606 if (create)
7607 unlock_bits |= EXTENT_DIRTY;
7608 else
7609 len = min_t(u64, len, root->sectorsize);
7610
7611 lockstart = start;
7612 lockend = start + len - 1;
7613
7614 if (current->journal_info) {
7615 /*
7616 * Need to pull our outstanding extents and set journal_info to NULL so
7617 * that anything that needs to check if there's a transaction doesn't get
7618 * confused.
7619 */
7620 dio_data = current->journal_info;
7621 current->journal_info = NULL;
7622 }
7623
7624 /*
7625 * If this errors out it's because we couldn't invalidate pagecache for
7626 * this range and we need to fallback to buffered.
7627 */
7628 if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
7629 create)) {
7630 ret = -ENOTBLK;
7631 goto err;
7632 }
7633
7634 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
7635 if (IS_ERR(em)) {
7636 ret = PTR_ERR(em);
7637 goto unlock_err;
7638 }
7639
7640 /*
7641 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7642 * io. INLINE is special, and we could probably kludge it in here, but
7643 * it's still buffered so for safety lets just fall back to the generic
7644 * buffered path.
7645 *
7646 * For COMPRESSED we _have_ to read the entire extent in so we can
7647 * decompress it, so there will be buffering required no matter what we
7648 * do, so go ahead and fallback to buffered.
7649 *
7650 * We return -ENOTBLK because that's what makes DIO go ahead and go back
7651 * to buffered IO. Don't blame me, this is the price we pay for using
7652 * the generic code.
7653 */
7654 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7655 em->block_start == EXTENT_MAP_INLINE) {
7656 free_extent_map(em);
7657 ret = -ENOTBLK;
7658 goto unlock_err;
7659 }
7660
7661 /* Just a good old fashioned hole, return */
7662 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
7663 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
7664 free_extent_map(em);
7665 goto unlock_err;
7666 }
7667
7668 /*
7669 * We don't allocate a new extent in the following cases
7670 *
7671 * 1) The inode is marked as NODATACOW. In this case we'll just use the
7672 * existing extent.
7673 * 2) The extent is marked as PREALLOC. We're good to go here and can
7674 * just use the extent.
7675 *
7676 */
7677 if (!create) {
7678 len = min(len, em->len - (start - em->start));
7679 lockstart = start + len;
7680 goto unlock;
7681 }
7682
7683 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7684 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7685 em->block_start != EXTENT_MAP_HOLE)) {
7686 int type;
7687 u64 block_start, orig_start, orig_block_len, ram_bytes;
7688
7689 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7690 type = BTRFS_ORDERED_PREALLOC;
7691 else
7692 type = BTRFS_ORDERED_NOCOW;
7693 len = min(len, em->len - (start - em->start));
7694 block_start = em->block_start + (start - em->start);
7695
7696 if (can_nocow_extent(inode, start, &len, &orig_start,
7697 &orig_block_len, &ram_bytes) == 1 &&
7698 btrfs_inc_nocow_writers(root->fs_info, block_start)) {
7699 struct extent_map *em2;
7700
7701 em2 = btrfs_create_dio_extent(inode, start, len,
7702 orig_start, block_start,
7703 len, orig_block_len,
7704 ram_bytes, type);
7705 btrfs_dec_nocow_writers(root->fs_info, block_start);
7706 if (type == BTRFS_ORDERED_PREALLOC) {
7707 free_extent_map(em);
7708 em = em2;
7709 }
7710 if (em2 && IS_ERR(em2)) {
7711 ret = PTR_ERR(em2);
7712 goto unlock_err;
7713 }
7714 goto unlock;
7715 }
7716 }
7717
7718 /*
7719 * this will cow the extent, reset the len in case we changed
7720 * it above
7721 */
7722 len = bh_result->b_size;
7723 free_extent_map(em);
7724 em = btrfs_new_extent_direct(inode, start, len);
7725 if (IS_ERR(em)) {
7726 ret = PTR_ERR(em);
7727 goto unlock_err;
7728 }
7729 len = min(len, em->len - (start - em->start));
7730 unlock:
7731 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7732 inode->i_blkbits;
7733 bh_result->b_size = len;
7734 bh_result->b_bdev = em->bdev;
7735 set_buffer_mapped(bh_result);
7736 if (create) {
7737 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7738 set_buffer_new(bh_result);
7739
7740 /*
7741 * Need to update the i_size under the extent lock so buffered
7742 * readers will get the updated i_size when we unlock.
7743 */
7744 if (start + len > i_size_read(inode))
7745 i_size_write(inode, start + len);
7746
7747 adjust_dio_outstanding_extents(inode, dio_data, len);
7748 btrfs_free_reserved_data_space(inode, start, len);
7749 WARN_ON(dio_data->reserve < len);
7750 dio_data->reserve -= len;
7751 dio_data->unsubmitted_oe_range_end = start + len;
7752 current->journal_info = dio_data;
7753 }
7754
7755 /*
7756 * In the case of write we need to clear and unlock the entire range,
7757 * in the case of read we need to unlock only the end area that we
7758 * aren't using if there is any left over space.
7759 */
7760 if (lockstart < lockend) {
7761 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7762 lockend, unlock_bits, 1, 0,
7763 &cached_state, GFP_NOFS);
7764 } else {
7765 free_extent_state(cached_state);
7766 }
7767
7768 free_extent_map(em);
7769
7770 return 0;
7771
7772 unlock_err:
7773 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7774 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
7775 err:
7776 if (dio_data)
7777 current->journal_info = dio_data;
7778 /*
7779 * Compensate the delalloc release we do in btrfs_direct_IO() when we
7780 * write less data then expected, so that we don't underflow our inode's
7781 * outstanding extents counter.
7782 */
7783 if (create && dio_data)
7784 adjust_dio_outstanding_extents(inode, dio_data, len);
7785
7786 return ret;
7787 }
7788
7789 static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio,
7790 int rw, int mirror_num)
7791 {
7792 struct btrfs_root *root = BTRFS_I(inode)->root;
7793 int ret;
7794
7795 BUG_ON(rw & REQ_WRITE);
7796
7797 bio_get(bio);
7798
7799 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
7800 BTRFS_WQ_ENDIO_DIO_REPAIR);
7801 if (ret)
7802 goto err;
7803
7804 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
7805 err:
7806 bio_put(bio);
7807 return ret;
7808 }
7809
7810 static int btrfs_check_dio_repairable(struct inode *inode,
7811 struct bio *failed_bio,
7812 struct io_failure_record *failrec,
7813 int failed_mirror)
7814 {
7815 int num_copies;
7816
7817 num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info,
7818 failrec->logical, failrec->len);
7819 if (num_copies == 1) {
7820 /*
7821 * we only have a single copy of the data, so don't bother with
7822 * all the retry and error correction code that follows. no
7823 * matter what the error is, it is very likely to persist.
7824 */
7825 pr_debug("Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
7826 num_copies, failrec->this_mirror, failed_mirror);
7827 return 0;
7828 }
7829
7830 failrec->failed_mirror = failed_mirror;
7831 failrec->this_mirror++;
7832 if (failrec->this_mirror == failed_mirror)
7833 failrec->this_mirror++;
7834
7835 if (failrec->this_mirror > num_copies) {
7836 pr_debug("Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
7837 num_copies, failrec->this_mirror, failed_mirror);
7838 return 0;
7839 }
7840
7841 return 1;
7842 }
7843
7844 static int dio_read_error(struct inode *inode, struct bio *failed_bio,
7845 struct page *page, unsigned int pgoff,
7846 u64 start, u64 end, int failed_mirror,
7847 bio_end_io_t *repair_endio, void *repair_arg)
7848 {
7849 struct io_failure_record *failrec;
7850 struct bio *bio;
7851 int isector;
7852 int read_mode;
7853 int ret;
7854
7855 BUG_ON(failed_bio->bi_rw & REQ_WRITE);
7856
7857 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
7858 if (ret)
7859 return ret;
7860
7861 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
7862 failed_mirror);
7863 if (!ret) {
7864 free_io_failure(inode, failrec);
7865 return -EIO;
7866 }
7867
7868 if ((failed_bio->bi_vcnt > 1)
7869 || (failed_bio->bi_io_vec->bv_len
7870 > BTRFS_I(inode)->root->sectorsize))
7871 read_mode = READ_SYNC | REQ_FAILFAST_DEV;
7872 else
7873 read_mode = READ_SYNC;
7874
7875 isector = start - btrfs_io_bio(failed_bio)->logical;
7876 isector >>= inode->i_sb->s_blocksize_bits;
7877 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
7878 pgoff, isector, repair_endio, repair_arg);
7879 if (!bio) {
7880 free_io_failure(inode, failrec);
7881 return -EIO;
7882 }
7883
7884 btrfs_debug(BTRFS_I(inode)->root->fs_info,
7885 "Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n",
7886 read_mode, failrec->this_mirror, failrec->in_validation);
7887
7888 ret = submit_dio_repair_bio(inode, bio, read_mode,
7889 failrec->this_mirror);
7890 if (ret) {
7891 free_io_failure(inode, failrec);
7892 bio_put(bio);
7893 }
7894
7895 return ret;
7896 }
7897
7898 struct btrfs_retry_complete {
7899 struct completion done;
7900 struct inode *inode;
7901 u64 start;
7902 int uptodate;
7903 };
7904
7905 static void btrfs_retry_endio_nocsum(struct bio *bio)
7906 {
7907 struct btrfs_retry_complete *done = bio->bi_private;
7908 struct inode *inode;
7909 struct bio_vec *bvec;
7910 int i;
7911
7912 if (bio->bi_error)
7913 goto end;
7914
7915 ASSERT(bio->bi_vcnt == 1);
7916 inode = bio->bi_io_vec->bv_page->mapping->host;
7917 ASSERT(bio->bi_io_vec->bv_len == BTRFS_I(inode)->root->sectorsize);
7918
7919 done->uptodate = 1;
7920 bio_for_each_segment_all(bvec, bio, i)
7921 clean_io_failure(done->inode, done->start, bvec->bv_page, 0);
7922 end:
7923 complete(&done->done);
7924 bio_put(bio);
7925 }
7926
7927 static int __btrfs_correct_data_nocsum(struct inode *inode,
7928 struct btrfs_io_bio *io_bio)
7929 {
7930 struct btrfs_fs_info *fs_info;
7931 struct bio_vec *bvec;
7932 struct btrfs_retry_complete done;
7933 u64 start;
7934 unsigned int pgoff;
7935 u32 sectorsize;
7936 int nr_sectors;
7937 int i;
7938 int ret;
7939
7940 fs_info = BTRFS_I(inode)->root->fs_info;
7941 sectorsize = BTRFS_I(inode)->root->sectorsize;
7942
7943 start = io_bio->logical;
7944 done.inode = inode;
7945
7946 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
7947 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
7948 pgoff = bvec->bv_offset;
7949
7950 next_block_or_try_again:
7951 done.uptodate = 0;
7952 done.start = start;
7953 init_completion(&done.done);
7954
7955 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page,
7956 pgoff, start, start + sectorsize - 1,
7957 io_bio->mirror_num,
7958 btrfs_retry_endio_nocsum, &done);
7959 if (ret)
7960 return ret;
7961
7962 wait_for_completion(&done.done);
7963
7964 if (!done.uptodate) {
7965 /* We might have another mirror, so try again */
7966 goto next_block_or_try_again;
7967 }
7968
7969 start += sectorsize;
7970
7971 if (nr_sectors--) {
7972 pgoff += sectorsize;
7973 goto next_block_or_try_again;
7974 }
7975 }
7976
7977 return 0;
7978 }
7979
7980 static void btrfs_retry_endio(struct bio *bio)
7981 {
7982 struct btrfs_retry_complete *done = bio->bi_private;
7983 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
7984 struct inode *inode;
7985 struct bio_vec *bvec;
7986 u64 start;
7987 int uptodate;
7988 int ret;
7989 int i;
7990
7991 if (bio->bi_error)
7992 goto end;
7993
7994 uptodate = 1;
7995
7996 start = done->start;
7997
7998 ASSERT(bio->bi_vcnt == 1);
7999 inode = bio->bi_io_vec->bv_page->mapping->host;
8000 ASSERT(bio->bi_io_vec->bv_len == BTRFS_I(inode)->root->sectorsize);
8001
8002 bio_for_each_segment_all(bvec, bio, i) {
8003 ret = __readpage_endio_check(done->inode, io_bio, i,
8004 bvec->bv_page, bvec->bv_offset,
8005 done->start, bvec->bv_len);
8006 if (!ret)
8007 clean_io_failure(done->inode, done->start,
8008 bvec->bv_page, bvec->bv_offset);
8009 else
8010 uptodate = 0;
8011 }
8012
8013 done->uptodate = uptodate;
8014 end:
8015 complete(&done->done);
8016 bio_put(bio);
8017 }
8018
8019 static int __btrfs_subio_endio_read(struct inode *inode,
8020 struct btrfs_io_bio *io_bio, int err)
8021 {
8022 struct btrfs_fs_info *fs_info;
8023 struct bio_vec *bvec;
8024 struct btrfs_retry_complete done;
8025 u64 start;
8026 u64 offset = 0;
8027 u32 sectorsize;
8028 int nr_sectors;
8029 unsigned int pgoff;
8030 int csum_pos;
8031 int i;
8032 int ret;
8033
8034 fs_info = BTRFS_I(inode)->root->fs_info;
8035 sectorsize = BTRFS_I(inode)->root->sectorsize;
8036
8037 err = 0;
8038 start = io_bio->logical;
8039 done.inode = inode;
8040
8041 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
8042 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec->bv_len);
8043
8044 pgoff = bvec->bv_offset;
8045 next_block:
8046 csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset);
8047 ret = __readpage_endio_check(inode, io_bio, csum_pos,
8048 bvec->bv_page, pgoff, start,
8049 sectorsize);
8050 if (likely(!ret))
8051 goto next;
8052 try_again:
8053 done.uptodate = 0;
8054 done.start = start;
8055 init_completion(&done.done);
8056
8057 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page,
8058 pgoff, start, start + sectorsize - 1,
8059 io_bio->mirror_num,
8060 btrfs_retry_endio, &done);
8061 if (ret) {
8062 err = ret;
8063 goto next;
8064 }
8065
8066 wait_for_completion(&done.done);
8067
8068 if (!done.uptodate) {
8069 /* We might have another mirror, so try again */
8070 goto try_again;
8071 }
8072 next:
8073 offset += sectorsize;
8074 start += sectorsize;
8075
8076 ASSERT(nr_sectors);
8077
8078 if (--nr_sectors) {
8079 pgoff += sectorsize;
8080 goto next_block;
8081 }
8082 }
8083
8084 return err;
8085 }
8086
8087 static int btrfs_subio_endio_read(struct inode *inode,
8088 struct btrfs_io_bio *io_bio, int err)
8089 {
8090 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8091
8092 if (skip_csum) {
8093 if (unlikely(err))
8094 return __btrfs_correct_data_nocsum(inode, io_bio);
8095 else
8096 return 0;
8097 } else {
8098 return __btrfs_subio_endio_read(inode, io_bio, err);
8099 }
8100 }
8101
8102 static void btrfs_endio_direct_read(struct bio *bio)
8103 {
8104 struct btrfs_dio_private *dip = bio->bi_private;
8105 struct inode *inode = dip->inode;
8106 struct bio *dio_bio;
8107 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8108 int err = bio->bi_error;
8109
8110 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
8111 err = btrfs_subio_endio_read(inode, io_bio, err);
8112
8113 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
8114 dip->logical_offset + dip->bytes - 1);
8115 dio_bio = dip->dio_bio;
8116
8117 kfree(dip);
8118
8119 dio_bio->bi_error = bio->bi_error;
8120 dio_end_io(dio_bio, bio->bi_error);
8121
8122 if (io_bio->end_io)
8123 io_bio->end_io(io_bio, err);
8124 bio_put(bio);
8125 }
8126
8127 static void btrfs_endio_direct_write_update_ordered(struct inode *inode,
8128 const u64 offset,
8129 const u64 bytes,
8130 const int uptodate)
8131 {
8132 struct btrfs_root *root = BTRFS_I(inode)->root;
8133 struct btrfs_ordered_extent *ordered = NULL;
8134 u64 ordered_offset = offset;
8135 u64 ordered_bytes = bytes;
8136 int ret;
8137
8138 again:
8139 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
8140 &ordered_offset,
8141 ordered_bytes,
8142 uptodate);
8143 if (!ret)
8144 goto out_test;
8145
8146 btrfs_init_work(&ordered->work, btrfs_endio_write_helper,
8147 finish_ordered_fn, NULL, NULL);
8148 btrfs_queue_work(root->fs_info->endio_write_workers,
8149 &ordered->work);
8150 out_test:
8151 /*
8152 * our bio might span multiple ordered extents. If we haven't
8153 * completed the accounting for the whole dio, go back and try again
8154 */
8155 if (ordered_offset < offset + bytes) {
8156 ordered_bytes = offset + bytes - ordered_offset;
8157 ordered = NULL;
8158 goto again;
8159 }
8160 }
8161
8162 static void btrfs_endio_direct_write(struct bio *bio)
8163 {
8164 struct btrfs_dio_private *dip = bio->bi_private;
8165 struct bio *dio_bio = dip->dio_bio;
8166
8167 btrfs_endio_direct_write_update_ordered(dip->inode,
8168 dip->logical_offset,
8169 dip->bytes,
8170 !bio->bi_error);
8171
8172 kfree(dip);
8173
8174 dio_bio->bi_error = bio->bi_error;
8175 dio_end_io(dio_bio, bio->bi_error);
8176 bio_put(bio);
8177 }
8178
8179 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
8180 struct bio *bio, int mirror_num,
8181 unsigned long bio_flags, u64 offset)
8182 {
8183 int ret;
8184 struct btrfs_root *root = BTRFS_I(inode)->root;
8185 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
8186 BUG_ON(ret); /* -ENOMEM */
8187 return 0;
8188 }
8189
8190 static void btrfs_end_dio_bio(struct bio *bio)
8191 {
8192 struct btrfs_dio_private *dip = bio->bi_private;
8193 int err = bio->bi_error;
8194
8195 if (err)
8196 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
8197 "direct IO failed ino %llu rw %lu sector %#Lx len %u err no %d",
8198 btrfs_ino(dip->inode), bio->bi_rw,
8199 (unsigned long long)bio->bi_iter.bi_sector,
8200 bio->bi_iter.bi_size, err);
8201
8202 if (dip->subio_endio)
8203 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
8204
8205 if (err) {
8206 dip->errors = 1;
8207
8208 /*
8209 * before atomic variable goto zero, we must make sure
8210 * dip->errors is perceived to be set.
8211 */
8212 smp_mb__before_atomic();
8213 }
8214
8215 /* if there are more bios still pending for this dio, just exit */
8216 if (!atomic_dec_and_test(&dip->pending_bios))
8217 goto out;
8218
8219 if (dip->errors) {
8220 bio_io_error(dip->orig_bio);
8221 } else {
8222 dip->dio_bio->bi_error = 0;
8223 bio_endio(dip->orig_bio);
8224 }
8225 out:
8226 bio_put(bio);
8227 }
8228
8229 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
8230 u64 first_sector, gfp_t gfp_flags)
8231 {
8232 struct bio *bio;
8233 bio = btrfs_bio_alloc(bdev, first_sector, BIO_MAX_PAGES, gfp_flags);
8234 if (bio)
8235 bio_associate_current(bio);
8236 return bio;
8237 }
8238
8239 static inline int btrfs_lookup_and_bind_dio_csum(struct btrfs_root *root,
8240 struct inode *inode,
8241 struct btrfs_dio_private *dip,
8242 struct bio *bio,
8243 u64 file_offset)
8244 {
8245 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8246 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
8247 int ret;
8248
8249 /*
8250 * We load all the csum data we need when we submit
8251 * the first bio to reduce the csum tree search and
8252 * contention.
8253 */
8254 if (dip->logical_offset == file_offset) {
8255 ret = btrfs_lookup_bio_sums_dio(root, inode, dip->orig_bio,
8256 file_offset);
8257 if (ret)
8258 return ret;
8259 }
8260
8261 if (bio == dip->orig_bio)
8262 return 0;
8263
8264 file_offset -= dip->logical_offset;
8265 file_offset >>= inode->i_sb->s_blocksize_bits;
8266 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
8267
8268 return 0;
8269 }
8270
8271 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
8272 int rw, u64 file_offset, int skip_sum,
8273 int async_submit)
8274 {
8275 struct btrfs_dio_private *dip = bio->bi_private;
8276 int write = rw & REQ_WRITE;
8277 struct btrfs_root *root = BTRFS_I(inode)->root;
8278 int ret;
8279
8280 if (async_submit)
8281 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
8282
8283 bio_get(bio);
8284
8285 if (!write) {
8286 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
8287 BTRFS_WQ_ENDIO_DATA);
8288 if (ret)
8289 goto err;
8290 }
8291
8292 if (skip_sum)
8293 goto map;
8294
8295 if (write && async_submit) {
8296 ret = btrfs_wq_submit_bio(root->fs_info,
8297 inode, rw, bio, 0, 0,
8298 file_offset,
8299 __btrfs_submit_bio_start_direct_io,
8300 __btrfs_submit_bio_done);
8301 goto err;
8302 } else if (write) {
8303 /*
8304 * If we aren't doing async submit, calculate the csum of the
8305 * bio now.
8306 */
8307 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
8308 if (ret)
8309 goto err;
8310 } else {
8311 ret = btrfs_lookup_and_bind_dio_csum(root, inode, dip, bio,
8312 file_offset);
8313 if (ret)
8314 goto err;
8315 }
8316 map:
8317 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
8318 err:
8319 bio_put(bio);
8320 return ret;
8321 }
8322
8323 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
8324 int skip_sum)
8325 {
8326 struct inode *inode = dip->inode;
8327 struct btrfs_root *root = BTRFS_I(inode)->root;
8328 struct bio *bio;
8329 struct bio *orig_bio = dip->orig_bio;
8330 struct bio_vec *bvec = orig_bio->bi_io_vec;
8331 u64 start_sector = orig_bio->bi_iter.bi_sector;
8332 u64 file_offset = dip->logical_offset;
8333 u64 submit_len = 0;
8334 u64 map_length;
8335 u32 blocksize = root->sectorsize;
8336 int async_submit = 0;
8337 int nr_sectors;
8338 int ret;
8339 int i;
8340
8341 map_length = orig_bio->bi_iter.bi_size;
8342 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
8343 &map_length, NULL, 0);
8344 if (ret)
8345 return -EIO;
8346
8347 if (map_length >= orig_bio->bi_iter.bi_size) {
8348 bio = orig_bio;
8349 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8350 goto submit;
8351 }
8352
8353 /* async crcs make it difficult to collect full stripe writes. */
8354 if (btrfs_get_alloc_profile(root, 1) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8355 async_submit = 0;
8356 else
8357 async_submit = 1;
8358
8359 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
8360 if (!bio)
8361 return -ENOMEM;
8362
8363 bio->bi_private = dip;
8364 bio->bi_end_io = btrfs_end_dio_bio;
8365 btrfs_io_bio(bio)->logical = file_offset;
8366 atomic_inc(&dip->pending_bios);
8367
8368 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
8369 nr_sectors = BTRFS_BYTES_TO_BLKS(root->fs_info, bvec->bv_len);
8370 i = 0;
8371 next_block:
8372 if (unlikely(map_length < submit_len + blocksize ||
8373 bio_add_page(bio, bvec->bv_page, blocksize,
8374 bvec->bv_offset + (i * blocksize)) < blocksize)) {
8375 /*
8376 * inc the count before we submit the bio so
8377 * we know the end IO handler won't happen before
8378 * we inc the count. Otherwise, the dip might get freed
8379 * before we're done setting it up
8380 */
8381 atomic_inc(&dip->pending_bios);
8382 ret = __btrfs_submit_dio_bio(bio, inode, rw,
8383 file_offset, skip_sum,
8384 async_submit);
8385 if (ret) {
8386 bio_put(bio);
8387 atomic_dec(&dip->pending_bios);
8388 goto out_err;
8389 }
8390
8391 start_sector += submit_len >> 9;
8392 file_offset += submit_len;
8393
8394 submit_len = 0;
8395
8396 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
8397 start_sector, GFP_NOFS);
8398 if (!bio)
8399 goto out_err;
8400 bio->bi_private = dip;
8401 bio->bi_end_io = btrfs_end_dio_bio;
8402 btrfs_io_bio(bio)->logical = file_offset;
8403
8404 map_length = orig_bio->bi_iter.bi_size;
8405 ret = btrfs_map_block(root->fs_info, rw,
8406 start_sector << 9,
8407 &map_length, NULL, 0);
8408 if (ret) {
8409 bio_put(bio);
8410 goto out_err;
8411 }
8412
8413 goto next_block;
8414 } else {
8415 submit_len += blocksize;
8416 if (--nr_sectors) {
8417 i++;
8418 goto next_block;
8419 }
8420 bvec++;
8421 }
8422 }
8423
8424 submit:
8425 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
8426 async_submit);
8427 if (!ret)
8428 return 0;
8429
8430 bio_put(bio);
8431 out_err:
8432 dip->errors = 1;
8433 /*
8434 * before atomic variable goto zero, we must
8435 * make sure dip->errors is perceived to be set.
8436 */
8437 smp_mb__before_atomic();
8438 if (atomic_dec_and_test(&dip->pending_bios))
8439 bio_io_error(dip->orig_bio);
8440
8441 /* bio_end_io() will handle error, so we needn't return it */
8442 return 0;
8443 }
8444
8445 static void btrfs_submit_direct(int rw, struct bio *dio_bio,
8446 struct inode *inode, loff_t file_offset)
8447 {
8448 struct btrfs_dio_private *dip = NULL;
8449 struct bio *io_bio = NULL;
8450 struct btrfs_io_bio *btrfs_bio;
8451 int skip_sum;
8452 int write = rw & REQ_WRITE;
8453 int ret = 0;
8454
8455 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8456
8457 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
8458 if (!io_bio) {
8459 ret = -ENOMEM;
8460 goto free_ordered;
8461 }
8462
8463 dip = kzalloc(sizeof(*dip), GFP_NOFS);
8464 if (!dip) {
8465 ret = -ENOMEM;
8466 goto free_ordered;
8467 }
8468
8469 dip->private = dio_bio->bi_private;
8470 dip->inode = inode;
8471 dip->logical_offset = file_offset;
8472 dip->bytes = dio_bio->bi_iter.bi_size;
8473 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8474 io_bio->bi_private = dip;
8475 dip->orig_bio = io_bio;
8476 dip->dio_bio = dio_bio;
8477 atomic_set(&dip->pending_bios, 0);
8478 btrfs_bio = btrfs_io_bio(io_bio);
8479 btrfs_bio->logical = file_offset;
8480
8481 if (write) {
8482 io_bio->bi_end_io = btrfs_endio_direct_write;
8483 } else {
8484 io_bio->bi_end_io = btrfs_endio_direct_read;
8485 dip->subio_endio = btrfs_subio_endio_read;
8486 }
8487
8488 /*
8489 * Reset the range for unsubmitted ordered extents (to a 0 length range)
8490 * even if we fail to submit a bio, because in such case we do the
8491 * corresponding error handling below and it must not be done a second
8492 * time by btrfs_direct_IO().
8493 */
8494 if (write) {
8495 struct btrfs_dio_data *dio_data = current->journal_info;
8496
8497 dio_data->unsubmitted_oe_range_end = dip->logical_offset +
8498 dip->bytes;
8499 dio_data->unsubmitted_oe_range_start =
8500 dio_data->unsubmitted_oe_range_end;
8501 }
8502
8503 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
8504 if (!ret)
8505 return;
8506
8507 if (btrfs_bio->end_io)
8508 btrfs_bio->end_io(btrfs_bio, ret);
8509
8510 free_ordered:
8511 /*
8512 * If we arrived here it means either we failed to submit the dip
8513 * or we either failed to clone the dio_bio or failed to allocate the
8514 * dip. If we cloned the dio_bio and allocated the dip, we can just
8515 * call bio_endio against our io_bio so that we get proper resource
8516 * cleanup if we fail to submit the dip, otherwise, we must do the
8517 * same as btrfs_endio_direct_[write|read] because we can't call these
8518 * callbacks - they require an allocated dip and a clone of dio_bio.
8519 */
8520 if (io_bio && dip) {
8521 io_bio->bi_error = -EIO;
8522 bio_endio(io_bio);
8523 /*
8524 * The end io callbacks free our dip, do the final put on io_bio
8525 * and all the cleanup and final put for dio_bio (through
8526 * dio_end_io()).
8527 */
8528 dip = NULL;
8529 io_bio = NULL;
8530 } else {
8531 if (write)
8532 btrfs_endio_direct_write_update_ordered(inode,
8533 file_offset,
8534 dio_bio->bi_iter.bi_size,
8535 0);
8536 else
8537 unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
8538 file_offset + dio_bio->bi_iter.bi_size - 1);
8539
8540 dio_bio->bi_error = -EIO;
8541 /*
8542 * Releases and cleans up our dio_bio, no need to bio_put()
8543 * nor bio_endio()/bio_io_error() against dio_bio.
8544 */
8545 dio_end_io(dio_bio, ret);
8546 }
8547 if (io_bio)
8548 bio_put(io_bio);
8549 kfree(dip);
8550 }
8551
8552 static ssize_t check_direct_IO(struct btrfs_root *root, struct kiocb *iocb,
8553 const struct iov_iter *iter, loff_t offset)
8554 {
8555 int seg;
8556 int i;
8557 unsigned blocksize_mask = root->sectorsize - 1;
8558 ssize_t retval = -EINVAL;
8559
8560 if (offset & blocksize_mask)
8561 goto out;
8562
8563 if (iov_iter_alignment(iter) & blocksize_mask)
8564 goto out;
8565
8566 /* If this is a write we don't need to check anymore */
8567 if (iov_iter_rw(iter) == WRITE)
8568 return 0;
8569 /*
8570 * Check to make sure we don't have duplicate iov_base's in this
8571 * iovec, if so return EINVAL, otherwise we'll get csum errors
8572 * when reading back.
8573 */
8574 for (seg = 0; seg < iter->nr_segs; seg++) {
8575 for (i = seg + 1; i < iter->nr_segs; i++) {
8576 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8577 goto out;
8578 }
8579 }
8580 retval = 0;
8581 out:
8582 return retval;
8583 }
8584
8585 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
8586 {
8587 struct file *file = iocb->ki_filp;
8588 struct inode *inode = file->f_mapping->host;
8589 struct btrfs_root *root = BTRFS_I(inode)->root;
8590 struct btrfs_dio_data dio_data = { 0 };
8591 loff_t offset = iocb->ki_pos;
8592 size_t count = 0;
8593 int flags = 0;
8594 bool wakeup = true;
8595 bool relock = false;
8596 ssize_t ret;
8597
8598 if (check_direct_IO(BTRFS_I(inode)->root, iocb, iter, offset))
8599 return 0;
8600
8601 inode_dio_begin(inode);
8602 smp_mb__after_atomic();
8603
8604 /*
8605 * The generic stuff only does filemap_write_and_wait_range, which
8606 * isn't enough if we've written compressed pages to this area, so
8607 * we need to flush the dirty pages again to make absolutely sure
8608 * that any outstanding dirty pages are on disk.
8609 */
8610 count = iov_iter_count(iter);
8611 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8612 &BTRFS_I(inode)->runtime_flags))
8613 filemap_fdatawrite_range(inode->i_mapping, offset,
8614 offset + count - 1);
8615
8616 if (iov_iter_rw(iter) == WRITE) {
8617 /*
8618 * If the write DIO is beyond the EOF, we need update
8619 * the isize, but it is protected by i_mutex. So we can
8620 * not unlock the i_mutex at this case.
8621 */
8622 if (offset + count <= inode->i_size) {
8623 inode_unlock(inode);
8624 relock = true;
8625 }
8626 ret = btrfs_delalloc_reserve_space(inode, offset, count);
8627 if (ret)
8628 goto out;
8629 dio_data.outstanding_extents = div64_u64(count +
8630 BTRFS_MAX_EXTENT_SIZE - 1,
8631 BTRFS_MAX_EXTENT_SIZE);
8632
8633 /*
8634 * We need to know how many extents we reserved so that we can
8635 * do the accounting properly if we go over the number we
8636 * originally calculated. Abuse current->journal_info for this.
8637 */
8638 dio_data.reserve = round_up(count, root->sectorsize);
8639 dio_data.unsubmitted_oe_range_start = (u64)offset;
8640 dio_data.unsubmitted_oe_range_end = (u64)offset;
8641 current->journal_info = &dio_data;
8642 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8643 &BTRFS_I(inode)->runtime_flags)) {
8644 inode_dio_end(inode);
8645 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8646 wakeup = false;
8647 }
8648
8649 ret = __blockdev_direct_IO(iocb, inode,
8650 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
8651 iter, btrfs_get_blocks_direct, NULL,
8652 btrfs_submit_direct, flags);
8653 if (iov_iter_rw(iter) == WRITE) {
8654 current->journal_info = NULL;
8655 if (ret < 0 && ret != -EIOCBQUEUED) {
8656 if (dio_data.reserve)
8657 btrfs_delalloc_release_space(inode, offset,
8658 dio_data.reserve);
8659 /*
8660 * On error we might have left some ordered extents
8661 * without submitting corresponding bios for them, so
8662 * cleanup them up to avoid other tasks getting them
8663 * and waiting for them to complete forever.
8664 */
8665 if (dio_data.unsubmitted_oe_range_start <
8666 dio_data.unsubmitted_oe_range_end)
8667 btrfs_endio_direct_write_update_ordered(inode,
8668 dio_data.unsubmitted_oe_range_start,
8669 dio_data.unsubmitted_oe_range_end -
8670 dio_data.unsubmitted_oe_range_start,
8671 0);
8672 } else if (ret >= 0 && (size_t)ret < count)
8673 btrfs_delalloc_release_space(inode, offset,
8674 count - (size_t)ret);
8675 }
8676 out:
8677 if (wakeup)
8678 inode_dio_end(inode);
8679 if (relock)
8680 inode_lock(inode);
8681
8682 return ret;
8683 }
8684
8685 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
8686
8687 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8688 __u64 start, __u64 len)
8689 {
8690 int ret;
8691
8692 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8693 if (ret)
8694 return ret;
8695
8696 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
8697 }
8698
8699 int btrfs_readpage(struct file *file, struct page *page)
8700 {
8701 struct extent_io_tree *tree;
8702 tree = &BTRFS_I(page->mapping->host)->io_tree;
8703 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8704 }
8705
8706 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8707 {
8708 struct extent_io_tree *tree;
8709 struct inode *inode = page->mapping->host;
8710 int ret;
8711
8712 if (current->flags & PF_MEMALLOC) {
8713 redirty_page_for_writepage(wbc, page);
8714 unlock_page(page);
8715 return 0;
8716 }
8717
8718 /*
8719 * If we are under memory pressure we will call this directly from the
8720 * VM, we need to make sure we have the inode referenced for the ordered
8721 * extent. If not just return like we didn't do anything.
8722 */
8723 if (!igrab(inode)) {
8724 redirty_page_for_writepage(wbc, page);
8725 return AOP_WRITEPAGE_ACTIVATE;
8726 }
8727 tree = &BTRFS_I(page->mapping->host)->io_tree;
8728 ret = extent_write_full_page(tree, page, btrfs_get_extent, wbc);
8729 btrfs_add_delayed_iput(inode);
8730 return ret;
8731 }
8732
8733 static int btrfs_writepages(struct address_space *mapping,
8734 struct writeback_control *wbc)
8735 {
8736 struct extent_io_tree *tree;
8737
8738 tree = &BTRFS_I(mapping->host)->io_tree;
8739 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
8740 }
8741
8742 static int
8743 btrfs_readpages(struct file *file, struct address_space *mapping,
8744 struct list_head *pages, unsigned nr_pages)
8745 {
8746 struct extent_io_tree *tree;
8747 tree = &BTRFS_I(mapping->host)->io_tree;
8748 return extent_readpages(tree, mapping, pages, nr_pages,
8749 btrfs_get_extent);
8750 }
8751 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8752 {
8753 struct extent_io_tree *tree;
8754 struct extent_map_tree *map;
8755 int ret;
8756
8757 tree = &BTRFS_I(page->mapping->host)->io_tree;
8758 map = &BTRFS_I(page->mapping->host)->extent_tree;
8759 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
8760 if (ret == 1) {
8761 ClearPagePrivate(page);
8762 set_page_private(page, 0);
8763 put_page(page);
8764 }
8765 return ret;
8766 }
8767
8768 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8769 {
8770 if (PageWriteback(page) || PageDirty(page))
8771 return 0;
8772 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
8773 }
8774
8775 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8776 unsigned int length)
8777 {
8778 struct inode *inode = page->mapping->host;
8779 struct extent_io_tree *tree;
8780 struct btrfs_ordered_extent *ordered;
8781 struct extent_state *cached_state = NULL;
8782 u64 page_start = page_offset(page);
8783 u64 page_end = page_start + PAGE_SIZE - 1;
8784 u64 start;
8785 u64 end;
8786 int inode_evicting = inode->i_state & I_FREEING;
8787
8788 /*
8789 * we have the page locked, so new writeback can't start,
8790 * and the dirty bit won't be cleared while we are here.
8791 *
8792 * Wait for IO on this page so that we can safely clear
8793 * the PagePrivate2 bit and do ordered accounting
8794 */
8795 wait_on_page_writeback(page);
8796
8797 tree = &BTRFS_I(inode)->io_tree;
8798 if (offset) {
8799 btrfs_releasepage(page, GFP_NOFS);
8800 return;
8801 }
8802
8803 if (!inode_evicting)
8804 lock_extent_bits(tree, page_start, page_end, &cached_state);
8805 again:
8806 start = page_start;
8807 ordered = btrfs_lookup_ordered_range(inode, start,
8808 page_end - start + 1);
8809 if (ordered) {
8810 end = min(page_end, ordered->file_offset + ordered->len - 1);
8811 /*
8812 * IO on this page will never be started, so we need
8813 * to account for any ordered extents now
8814 */
8815 if (!inode_evicting)
8816 clear_extent_bit(tree, start, end,
8817 EXTENT_DIRTY | EXTENT_DELALLOC |
8818 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8819 EXTENT_DEFRAG, 1, 0, &cached_state,
8820 GFP_NOFS);
8821 /*
8822 * whoever cleared the private bit is responsible
8823 * for the finish_ordered_io
8824 */
8825 if (TestClearPagePrivate2(page)) {
8826 struct btrfs_ordered_inode_tree *tree;
8827 u64 new_len;
8828
8829 tree = &BTRFS_I(inode)->ordered_tree;
8830
8831 spin_lock_irq(&tree->lock);
8832 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8833 new_len = start - ordered->file_offset;
8834 if (new_len < ordered->truncated_len)
8835 ordered->truncated_len = new_len;
8836 spin_unlock_irq(&tree->lock);
8837
8838 if (btrfs_dec_test_ordered_pending(inode, &ordered,
8839 start,
8840 end - start + 1, 1))
8841 btrfs_finish_ordered_io(ordered);
8842 }
8843 btrfs_put_ordered_extent(ordered);
8844 if (!inode_evicting) {
8845 cached_state = NULL;
8846 lock_extent_bits(tree, start, end,
8847 &cached_state);
8848 }
8849
8850 start = end + 1;
8851 if (start < page_end)
8852 goto again;
8853 }
8854
8855 /*
8856 * Qgroup reserved space handler
8857 * Page here will be either
8858 * 1) Already written to disk
8859 * In this case, its reserved space is released from data rsv map
8860 * and will be freed by delayed_ref handler finally.
8861 * So even we call qgroup_free_data(), it won't decrease reserved
8862 * space.
8863 * 2) Not written to disk
8864 * This means the reserved space should be freed here.
8865 */
8866 btrfs_qgroup_free_data(inode, page_start, PAGE_SIZE);
8867 if (!inode_evicting) {
8868 clear_extent_bit(tree, page_start, page_end,
8869 EXTENT_LOCKED | EXTENT_DIRTY |
8870 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
8871 EXTENT_DEFRAG, 1, 1,
8872 &cached_state, GFP_NOFS);
8873
8874 __btrfs_releasepage(page, GFP_NOFS);
8875 }
8876
8877 ClearPageChecked(page);
8878 if (PagePrivate(page)) {
8879 ClearPagePrivate(page);
8880 set_page_private(page, 0);
8881 put_page(page);
8882 }
8883 }
8884
8885 /*
8886 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
8887 * called from a page fault handler when a page is first dirtied. Hence we must
8888 * be careful to check for EOF conditions here. We set the page up correctly
8889 * for a written page which means we get ENOSPC checking when writing into
8890 * holes and correct delalloc and unwritten extent mapping on filesystems that
8891 * support these features.
8892 *
8893 * We are not allowed to take the i_mutex here so we have to play games to
8894 * protect against truncate races as the page could now be beyond EOF. Because
8895 * vmtruncate() writes the inode size before removing pages, once we have the
8896 * page lock we can determine safely if the page is beyond EOF. If it is not
8897 * beyond EOF, then the page is guaranteed safe against truncation until we
8898 * unlock the page.
8899 */
8900 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
8901 {
8902 struct page *page = vmf->page;
8903 struct inode *inode = file_inode(vma->vm_file);
8904 struct btrfs_root *root = BTRFS_I(inode)->root;
8905 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8906 struct btrfs_ordered_extent *ordered;
8907 struct extent_state *cached_state = NULL;
8908 char *kaddr;
8909 unsigned long zero_start;
8910 loff_t size;
8911 int ret;
8912 int reserved = 0;
8913 u64 reserved_space;
8914 u64 page_start;
8915 u64 page_end;
8916 u64 end;
8917
8918 reserved_space = PAGE_SIZE;
8919
8920 sb_start_pagefault(inode->i_sb);
8921 page_start = page_offset(page);
8922 page_end = page_start + PAGE_SIZE - 1;
8923 end = page_end;
8924
8925 /*
8926 * Reserving delalloc space after obtaining the page lock can lead to
8927 * deadlock. For example, if a dirty page is locked by this function
8928 * and the call to btrfs_delalloc_reserve_space() ends up triggering
8929 * dirty page write out, then the btrfs_writepage() function could
8930 * end up waiting indefinitely to get a lock on the page currently
8931 * being processed by btrfs_page_mkwrite() function.
8932 */
8933 ret = btrfs_delalloc_reserve_space(inode, page_start,
8934 reserved_space);
8935 if (!ret) {
8936 ret = file_update_time(vma->vm_file);
8937 reserved = 1;
8938 }
8939 if (ret) {
8940 if (ret == -ENOMEM)
8941 ret = VM_FAULT_OOM;
8942 else /* -ENOSPC, -EIO, etc */
8943 ret = VM_FAULT_SIGBUS;
8944 if (reserved)
8945 goto out;
8946 goto out_noreserve;
8947 }
8948
8949 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
8950 again:
8951 lock_page(page);
8952 size = i_size_read(inode);
8953
8954 if ((page->mapping != inode->i_mapping) ||
8955 (page_start >= size)) {
8956 /* page got truncated out from underneath us */
8957 goto out_unlock;
8958 }
8959 wait_on_page_writeback(page);
8960
8961 lock_extent_bits(io_tree, page_start, page_end, &cached_state);
8962 set_page_extent_mapped(page);
8963
8964 /*
8965 * we can't set the delalloc bits if there are pending ordered
8966 * extents. Drop our locks and wait for them to finish
8967 */
8968 ordered = btrfs_lookup_ordered_range(inode, page_start, page_end);
8969 if (ordered) {
8970 unlock_extent_cached(io_tree, page_start, page_end,
8971 &cached_state, GFP_NOFS);
8972 unlock_page(page);
8973 btrfs_start_ordered_extent(inode, ordered, 1);
8974 btrfs_put_ordered_extent(ordered);
8975 goto again;
8976 }
8977
8978 if (page->index == ((size - 1) >> PAGE_SHIFT)) {
8979 reserved_space = round_up(size - page_start, root->sectorsize);
8980 if (reserved_space < PAGE_SIZE) {
8981 end = page_start + reserved_space - 1;
8982 spin_lock(&BTRFS_I(inode)->lock);
8983 BTRFS_I(inode)->outstanding_extents++;
8984 spin_unlock(&BTRFS_I(inode)->lock);
8985 btrfs_delalloc_release_space(inode, page_start,
8986 PAGE_SIZE - reserved_space);
8987 }
8988 }
8989
8990 /*
8991 * XXX - page_mkwrite gets called every time the page is dirtied, even
8992 * if it was already dirty, so for space accounting reasons we need to
8993 * clear any delalloc bits for the range we are fixing to save. There
8994 * is probably a better way to do this, but for now keep consistent with
8995 * prepare_pages in the normal write path.
8996 */
8997 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
8998 EXTENT_DIRTY | EXTENT_DELALLOC |
8999 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
9000 0, 0, &cached_state, GFP_NOFS);
9001
9002 ret = btrfs_set_extent_delalloc(inode, page_start, end,
9003 &cached_state);
9004 if (ret) {
9005 unlock_extent_cached(io_tree, page_start, page_end,
9006 &cached_state, GFP_NOFS);
9007 ret = VM_FAULT_SIGBUS;
9008 goto out_unlock;
9009 }
9010 ret = 0;
9011
9012 /* page is wholly or partially inside EOF */
9013 if (page_start + PAGE_SIZE > size)
9014 zero_start = size & ~PAGE_MASK;
9015 else
9016 zero_start = PAGE_SIZE;
9017
9018 if (zero_start != PAGE_SIZE) {
9019 kaddr = kmap(page);
9020 memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start);
9021 flush_dcache_page(page);
9022 kunmap(page);
9023 }
9024 ClearPageChecked(page);
9025 set_page_dirty(page);
9026 SetPageUptodate(page);
9027
9028 BTRFS_I(inode)->last_trans = root->fs_info->generation;
9029 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
9030 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
9031
9032 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
9033
9034 out_unlock:
9035 if (!ret) {
9036 sb_end_pagefault(inode->i_sb);
9037 return VM_FAULT_LOCKED;
9038 }
9039 unlock_page(page);
9040 out:
9041 btrfs_delalloc_release_space(inode, page_start, reserved_space);
9042 out_noreserve:
9043 sb_end_pagefault(inode->i_sb);
9044 return ret;
9045 }
9046
9047 static int btrfs_truncate(struct inode *inode)
9048 {
9049 struct btrfs_root *root = BTRFS_I(inode)->root;
9050 struct btrfs_block_rsv *rsv;
9051 int ret = 0;
9052 int err = 0;
9053 struct btrfs_trans_handle *trans;
9054 u64 mask = root->sectorsize - 1;
9055 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
9056
9057 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
9058 (u64)-1);
9059 if (ret)
9060 return ret;
9061
9062 /*
9063 * Yes ladies and gentlemen, this is indeed ugly. The fact is we have
9064 * 3 things going on here
9065 *
9066 * 1) We need to reserve space for our orphan item and the space to
9067 * delete our orphan item. Lord knows we don't want to have a dangling
9068 * orphan item because we didn't reserve space to remove it.
9069 *
9070 * 2) We need to reserve space to update our inode.
9071 *
9072 * 3) We need to have something to cache all the space that is going to
9073 * be free'd up by the truncate operation, but also have some slack
9074 * space reserved in case it uses space during the truncate (thank you
9075 * very much snapshotting).
9076 *
9077 * And we need these to all be separate. The fact is we can use a lot of
9078 * space doing the truncate, and we have no earthly idea how much space
9079 * we will use, so we need the truncate reservation to be separate so it
9080 * doesn't end up using space reserved for updating the inode or
9081 * removing the orphan item. We also need to be able to stop the
9082 * transaction and start a new one, which means we need to be able to
9083 * update the inode several times, and we have no idea of knowing how
9084 * many times that will be, so we can't just reserve 1 item for the
9085 * entirety of the operation, so that has to be done separately as well.
9086 * Then there is the orphan item, which does indeed need to be held on
9087 * to for the whole operation, and we need nobody to touch this reserved
9088 * space except the orphan code.
9089 *
9090 * So that leaves us with
9091 *
9092 * 1) root->orphan_block_rsv - for the orphan deletion.
9093 * 2) rsv - for the truncate reservation, which we will steal from the
9094 * transaction reservation.
9095 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
9096 * updating the inode.
9097 */
9098 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
9099 if (!rsv)
9100 return -ENOMEM;
9101 rsv->size = min_size;
9102 rsv->failfast = 1;
9103
9104 /*
9105 * 1 for the truncate slack space
9106 * 1 for updating the inode.
9107 */
9108 trans = btrfs_start_transaction(root, 2);
9109 if (IS_ERR(trans)) {
9110 err = PTR_ERR(trans);
9111 goto out;
9112 }
9113
9114 /* Migrate the slack space for the truncate to our reserve */
9115 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
9116 min_size);
9117 BUG_ON(ret);
9118
9119 /*
9120 * So if we truncate and then write and fsync we normally would just
9121 * write the extents that changed, which is a problem if we need to
9122 * first truncate that entire inode. So set this flag so we write out
9123 * all of the extents in the inode to the sync log so we're completely
9124 * safe.
9125 */
9126 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
9127 trans->block_rsv = rsv;
9128
9129 while (1) {
9130 ret = btrfs_truncate_inode_items(trans, root, inode,
9131 inode->i_size,
9132 BTRFS_EXTENT_DATA_KEY);
9133 if (ret != -ENOSPC && ret != -EAGAIN) {
9134 err = ret;
9135 break;
9136 }
9137
9138 trans->block_rsv = &root->fs_info->trans_block_rsv;
9139 ret = btrfs_update_inode(trans, root, inode);
9140 if (ret) {
9141 err = ret;
9142 break;
9143 }
9144
9145 btrfs_end_transaction(trans, root);
9146 btrfs_btree_balance_dirty(root);
9147
9148 trans = btrfs_start_transaction(root, 2);
9149 if (IS_ERR(trans)) {
9150 ret = err = PTR_ERR(trans);
9151 trans = NULL;
9152 break;
9153 }
9154
9155 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
9156 rsv, min_size);
9157 BUG_ON(ret); /* shouldn't happen */
9158 trans->block_rsv = rsv;
9159 }
9160
9161 if (ret == 0 && inode->i_nlink > 0) {
9162 trans->block_rsv = root->orphan_block_rsv;
9163 ret = btrfs_orphan_del(trans, inode);
9164 if (ret)
9165 err = ret;
9166 }
9167
9168 if (trans) {
9169 trans->block_rsv = &root->fs_info->trans_block_rsv;
9170 ret = btrfs_update_inode(trans, root, inode);
9171 if (ret && !err)
9172 err = ret;
9173
9174 ret = btrfs_end_transaction(trans, root);
9175 btrfs_btree_balance_dirty(root);
9176 }
9177
9178 out:
9179 btrfs_free_block_rsv(root, rsv);
9180
9181 if (ret && !err)
9182 err = ret;
9183
9184 return err;
9185 }
9186
9187 /*
9188 * create a new subvolume directory/inode (helper for the ioctl).
9189 */
9190 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
9191 struct btrfs_root *new_root,
9192 struct btrfs_root *parent_root,
9193 u64 new_dirid)
9194 {
9195 struct inode *inode;
9196 int err;
9197 u64 index = 0;
9198
9199 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
9200 new_dirid, new_dirid,
9201 S_IFDIR | (~current_umask() & S_IRWXUGO),
9202 &index);
9203 if (IS_ERR(inode))
9204 return PTR_ERR(inode);
9205 inode->i_op = &btrfs_dir_inode_operations;
9206 inode->i_fop = &btrfs_dir_file_operations;
9207
9208 set_nlink(inode, 1);
9209 btrfs_i_size_write(inode, 0);
9210 unlock_new_inode(inode);
9211
9212 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
9213 if (err)
9214 btrfs_err(new_root->fs_info,
9215 "error inheriting subvolume %llu properties: %d",
9216 new_root->root_key.objectid, err);
9217
9218 err = btrfs_update_inode(trans, new_root, inode);
9219
9220 iput(inode);
9221 return err;
9222 }
9223
9224 struct inode *btrfs_alloc_inode(struct super_block *sb)
9225 {
9226 struct btrfs_inode *ei;
9227 struct inode *inode;
9228
9229 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
9230 if (!ei)
9231 return NULL;
9232
9233 ei->root = NULL;
9234 ei->generation = 0;
9235 ei->last_trans = 0;
9236 ei->last_sub_trans = 0;
9237 ei->logged_trans = 0;
9238 ei->delalloc_bytes = 0;
9239 ei->defrag_bytes = 0;
9240 ei->disk_i_size = 0;
9241 ei->flags = 0;
9242 ei->csum_bytes = 0;
9243 ei->index_cnt = (u64)-1;
9244 ei->dir_index = 0;
9245 ei->last_unlink_trans = 0;
9246 ei->last_log_commit = 0;
9247 ei->delayed_iput_count = 0;
9248
9249 spin_lock_init(&ei->lock);
9250 ei->outstanding_extents = 0;
9251 ei->reserved_extents = 0;
9252
9253 ei->runtime_flags = 0;
9254 ei->force_compress = BTRFS_COMPRESS_NONE;
9255
9256 ei->delayed_node = NULL;
9257
9258 ei->i_otime.tv_sec = 0;
9259 ei->i_otime.tv_nsec = 0;
9260
9261 inode = &ei->vfs_inode;
9262 extent_map_tree_init(&ei->extent_tree);
9263 extent_io_tree_init(&ei->io_tree, &inode->i_data);
9264 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
9265 ei->io_tree.track_uptodate = 1;
9266 ei->io_failure_tree.track_uptodate = 1;
9267 atomic_set(&ei->sync_writers, 0);
9268 mutex_init(&ei->log_mutex);
9269 mutex_init(&ei->delalloc_mutex);
9270 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
9271 INIT_LIST_HEAD(&ei->delalloc_inodes);
9272 INIT_LIST_HEAD(&ei->delayed_iput);
9273 RB_CLEAR_NODE(&ei->rb_node);
9274 init_rwsem(&ei->dio_sem);
9275
9276 return inode;
9277 }
9278
9279 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
9280 void btrfs_test_destroy_inode(struct inode *inode)
9281 {
9282 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
9283 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9284 }
9285 #endif
9286
9287 static void btrfs_i_callback(struct rcu_head *head)
9288 {
9289 struct inode *inode = container_of(head, struct inode, i_rcu);
9290 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9291 }
9292
9293 void btrfs_destroy_inode(struct inode *inode)
9294 {
9295 struct btrfs_ordered_extent *ordered;
9296 struct btrfs_root *root = BTRFS_I(inode)->root;
9297
9298 WARN_ON(!hlist_empty(&inode->i_dentry));
9299 WARN_ON(inode->i_data.nrpages);
9300 WARN_ON(BTRFS_I(inode)->outstanding_extents);
9301 WARN_ON(BTRFS_I(inode)->reserved_extents);
9302 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
9303 WARN_ON(BTRFS_I(inode)->csum_bytes);
9304 WARN_ON(BTRFS_I(inode)->defrag_bytes);
9305
9306 /*
9307 * This can happen where we create an inode, but somebody else also
9308 * created the same inode and we need to destroy the one we already
9309 * created.
9310 */
9311 if (!root)
9312 goto free;
9313
9314 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
9315 &BTRFS_I(inode)->runtime_flags)) {
9316 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
9317 btrfs_ino(inode));
9318 atomic_dec(&root->orphan_inodes);
9319 }
9320
9321 while (1) {
9322 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
9323 if (!ordered)
9324 break;
9325 else {
9326 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
9327 ordered->file_offset, ordered->len);
9328 btrfs_remove_ordered_extent(inode, ordered);
9329 btrfs_put_ordered_extent(ordered);
9330 btrfs_put_ordered_extent(ordered);
9331 }
9332 }
9333 btrfs_qgroup_check_reserved_leak(inode);
9334 inode_tree_del(inode);
9335 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
9336 free:
9337 call_rcu(&inode->i_rcu, btrfs_i_callback);
9338 }
9339
9340 int btrfs_drop_inode(struct inode *inode)
9341 {
9342 struct btrfs_root *root = BTRFS_I(inode)->root;
9343
9344 if (root == NULL)
9345 return 1;
9346
9347 /* the snap/subvol tree is on deleting */
9348 if (btrfs_root_refs(&root->root_item) == 0)
9349 return 1;
9350 else
9351 return generic_drop_inode(inode);
9352 }
9353
9354 static void init_once(void *foo)
9355 {
9356 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
9357
9358 inode_init_once(&ei->vfs_inode);
9359 }
9360
9361 void btrfs_destroy_cachep(void)
9362 {
9363 /*
9364 * Make sure all delayed rcu free inodes are flushed before we
9365 * destroy cache.
9366 */
9367 rcu_barrier();
9368 kmem_cache_destroy(btrfs_inode_cachep);
9369 kmem_cache_destroy(btrfs_trans_handle_cachep);
9370 kmem_cache_destroy(btrfs_transaction_cachep);
9371 kmem_cache_destroy(btrfs_path_cachep);
9372 kmem_cache_destroy(btrfs_free_space_cachep);
9373 }
9374
9375 int btrfs_init_cachep(void)
9376 {
9377 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
9378 sizeof(struct btrfs_inode), 0,
9379 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
9380 init_once);
9381 if (!btrfs_inode_cachep)
9382 goto fail;
9383
9384 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
9385 sizeof(struct btrfs_trans_handle), 0,
9386 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9387 if (!btrfs_trans_handle_cachep)
9388 goto fail;
9389
9390 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
9391 sizeof(struct btrfs_transaction), 0,
9392 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9393 if (!btrfs_transaction_cachep)
9394 goto fail;
9395
9396 btrfs_path_cachep = kmem_cache_create("btrfs_path",
9397 sizeof(struct btrfs_path), 0,
9398 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9399 if (!btrfs_path_cachep)
9400 goto fail;
9401
9402 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
9403 sizeof(struct btrfs_free_space), 0,
9404 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
9405 if (!btrfs_free_space_cachep)
9406 goto fail;
9407
9408 return 0;
9409 fail:
9410 btrfs_destroy_cachep();
9411 return -ENOMEM;
9412 }
9413
9414 static int btrfs_getattr(struct vfsmount *mnt,
9415 struct dentry *dentry, struct kstat *stat)
9416 {
9417 u64 delalloc_bytes;
9418 struct inode *inode = d_inode(dentry);
9419 u32 blocksize = inode->i_sb->s_blocksize;
9420
9421 generic_fillattr(inode, stat);
9422 stat->dev = BTRFS_I(inode)->root->anon_dev;
9423
9424 spin_lock(&BTRFS_I(inode)->lock);
9425 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
9426 spin_unlock(&BTRFS_I(inode)->lock);
9427 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9428 ALIGN(delalloc_bytes, blocksize)) >> 9;
9429 return 0;
9430 }
9431
9432 static int btrfs_rename_exchange(struct inode *old_dir,
9433 struct dentry *old_dentry,
9434 struct inode *new_dir,
9435 struct dentry *new_dentry)
9436 {
9437 struct btrfs_trans_handle *trans;
9438 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9439 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9440 struct inode *new_inode = new_dentry->d_inode;
9441 struct inode *old_inode = old_dentry->d_inode;
9442 struct timespec ctime = CURRENT_TIME;
9443 struct dentry *parent;
9444 u64 old_ino = btrfs_ino(old_inode);
9445 u64 new_ino = btrfs_ino(new_inode);
9446 u64 old_idx = 0;
9447 u64 new_idx = 0;
9448 u64 root_objectid;
9449 int ret;
9450 bool root_log_pinned = false;
9451 bool dest_log_pinned = false;
9452
9453 /* we only allow rename subvolume link between subvolumes */
9454 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9455 return -EXDEV;
9456
9457 /* close the race window with snapshot create/destroy ioctl */
9458 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9459 down_read(&root->fs_info->subvol_sem);
9460 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9461 down_read(&dest->fs_info->subvol_sem);
9462
9463 /*
9464 * We want to reserve the absolute worst case amount of items. So if
9465 * both inodes are subvols and we need to unlink them then that would
9466 * require 4 item modifications, but if they are both normal inodes it
9467 * would require 5 item modifications, so we'll assume their normal
9468 * inodes. So 5 * 2 is 10, plus 2 for the new links, so 12 total items
9469 * should cover the worst case number of items we'll modify.
9470 */
9471 trans = btrfs_start_transaction(root, 12);
9472 if (IS_ERR(trans)) {
9473 ret = PTR_ERR(trans);
9474 goto out_notrans;
9475 }
9476
9477 /*
9478 * We need to find a free sequence number both in the source and
9479 * in the destination directory for the exchange.
9480 */
9481 ret = btrfs_set_inode_index(new_dir, &old_idx);
9482 if (ret)
9483 goto out_fail;
9484 ret = btrfs_set_inode_index(old_dir, &new_idx);
9485 if (ret)
9486 goto out_fail;
9487
9488 BTRFS_I(old_inode)->dir_index = 0ULL;
9489 BTRFS_I(new_inode)->dir_index = 0ULL;
9490
9491 /* Reference for the source. */
9492 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9493 /* force full log commit if subvolume involved. */
9494 btrfs_set_log_full_commit(root->fs_info, trans);
9495 } else {
9496 btrfs_pin_log_trans(root);
9497 root_log_pinned = true;
9498 ret = btrfs_insert_inode_ref(trans, dest,
9499 new_dentry->d_name.name,
9500 new_dentry->d_name.len,
9501 old_ino,
9502 btrfs_ino(new_dir), old_idx);
9503 if (ret)
9504 goto out_fail;
9505 }
9506
9507 /* And now for the dest. */
9508 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9509 /* force full log commit if subvolume involved. */
9510 btrfs_set_log_full_commit(dest->fs_info, trans);
9511 } else {
9512 btrfs_pin_log_trans(dest);
9513 dest_log_pinned = true;
9514 ret = btrfs_insert_inode_ref(trans, root,
9515 old_dentry->d_name.name,
9516 old_dentry->d_name.len,
9517 new_ino,
9518 btrfs_ino(old_dir), new_idx);
9519 if (ret)
9520 goto out_fail;
9521 }
9522
9523 /* Update inode version and ctime/mtime. */
9524 inode_inc_iversion(old_dir);
9525 inode_inc_iversion(new_dir);
9526 inode_inc_iversion(old_inode);
9527 inode_inc_iversion(new_inode);
9528 old_dir->i_ctime = old_dir->i_mtime = ctime;
9529 new_dir->i_ctime = new_dir->i_mtime = ctime;
9530 old_inode->i_ctime = ctime;
9531 new_inode->i_ctime = ctime;
9532
9533 if (old_dentry->d_parent != new_dentry->d_parent) {
9534 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
9535 btrfs_record_unlink_dir(trans, new_dir, new_inode, 1);
9536 }
9537
9538 /* src is a subvolume */
9539 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9540 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9541 ret = btrfs_unlink_subvol(trans, root, old_dir,
9542 root_objectid,
9543 old_dentry->d_name.name,
9544 old_dentry->d_name.len);
9545 } else { /* src is an inode */
9546 ret = __btrfs_unlink_inode(trans, root, old_dir,
9547 old_dentry->d_inode,
9548 old_dentry->d_name.name,
9549 old_dentry->d_name.len);
9550 if (!ret)
9551 ret = btrfs_update_inode(trans, root, old_inode);
9552 }
9553 if (ret) {
9554 btrfs_abort_transaction(trans, root, ret);
9555 goto out_fail;
9556 }
9557
9558 /* dest is a subvolume */
9559 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9560 root_objectid = BTRFS_I(new_inode)->root->root_key.objectid;
9561 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9562 root_objectid,
9563 new_dentry->d_name.name,
9564 new_dentry->d_name.len);
9565 } else { /* dest is an inode */
9566 ret = __btrfs_unlink_inode(trans, dest, new_dir,
9567 new_dentry->d_inode,
9568 new_dentry->d_name.name,
9569 new_dentry->d_name.len);
9570 if (!ret)
9571 ret = btrfs_update_inode(trans, dest, new_inode);
9572 }
9573 if (ret) {
9574 btrfs_abort_transaction(trans, root, ret);
9575 goto out_fail;
9576 }
9577
9578 ret = btrfs_add_link(trans, new_dir, old_inode,
9579 new_dentry->d_name.name,
9580 new_dentry->d_name.len, 0, old_idx);
9581 if (ret) {
9582 btrfs_abort_transaction(trans, root, ret);
9583 goto out_fail;
9584 }
9585
9586 ret = btrfs_add_link(trans, old_dir, new_inode,
9587 old_dentry->d_name.name,
9588 old_dentry->d_name.len, 0, new_idx);
9589 if (ret) {
9590 btrfs_abort_transaction(trans, root, ret);
9591 goto out_fail;
9592 }
9593
9594 if (old_inode->i_nlink == 1)
9595 BTRFS_I(old_inode)->dir_index = old_idx;
9596 if (new_inode->i_nlink == 1)
9597 BTRFS_I(new_inode)->dir_index = new_idx;
9598
9599 if (root_log_pinned) {
9600 parent = new_dentry->d_parent;
9601 btrfs_log_new_name(trans, old_inode, old_dir, parent);
9602 btrfs_end_log_trans(root);
9603 root_log_pinned = false;
9604 }
9605 if (dest_log_pinned) {
9606 parent = old_dentry->d_parent;
9607 btrfs_log_new_name(trans, new_inode, new_dir, parent);
9608 btrfs_end_log_trans(dest);
9609 dest_log_pinned = false;
9610 }
9611 out_fail:
9612 /*
9613 * If we have pinned a log and an error happened, we unpin tasks
9614 * trying to sync the log and force them to fallback to a transaction
9615 * commit if the log currently contains any of the inodes involved in
9616 * this rename operation (to ensure we do not persist a log with an
9617 * inconsistent state for any of these inodes or leading to any
9618 * inconsistencies when replayed). If the transaction was aborted, the
9619 * abortion reason is propagated to userspace when attempting to commit
9620 * the transaction. If the log does not contain any of these inodes, we
9621 * allow the tasks to sync it.
9622 */
9623 if (ret && (root_log_pinned || dest_log_pinned)) {
9624 if (btrfs_inode_in_log(old_dir, root->fs_info->generation) ||
9625 btrfs_inode_in_log(new_dir, root->fs_info->generation) ||
9626 btrfs_inode_in_log(old_inode, root->fs_info->generation) ||
9627 (new_inode &&
9628 btrfs_inode_in_log(new_inode, root->fs_info->generation)))
9629 btrfs_set_log_full_commit(root->fs_info, trans);
9630
9631 if (root_log_pinned) {
9632 btrfs_end_log_trans(root);
9633 root_log_pinned = false;
9634 }
9635 if (dest_log_pinned) {
9636 btrfs_end_log_trans(dest);
9637 dest_log_pinned = false;
9638 }
9639 }
9640 ret = btrfs_end_transaction(trans, root);
9641 out_notrans:
9642 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9643 up_read(&dest->fs_info->subvol_sem);
9644 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9645 up_read(&root->fs_info->subvol_sem);
9646
9647 return ret;
9648 }
9649
9650 static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans,
9651 struct btrfs_root *root,
9652 struct inode *dir,
9653 struct dentry *dentry)
9654 {
9655 int ret;
9656 struct inode *inode;
9657 u64 objectid;
9658 u64 index;
9659
9660 ret = btrfs_find_free_ino(root, &objectid);
9661 if (ret)
9662 return ret;
9663
9664 inode = btrfs_new_inode(trans, root, dir,
9665 dentry->d_name.name,
9666 dentry->d_name.len,
9667 btrfs_ino(dir),
9668 objectid,
9669 S_IFCHR | WHITEOUT_MODE,
9670 &index);
9671
9672 if (IS_ERR(inode)) {
9673 ret = PTR_ERR(inode);
9674 return ret;
9675 }
9676
9677 inode->i_op = &btrfs_special_inode_operations;
9678 init_special_inode(inode, inode->i_mode,
9679 WHITEOUT_DEV);
9680
9681 ret = btrfs_init_inode_security(trans, inode, dir,
9682 &dentry->d_name);
9683 if (ret)
9684 goto out;
9685
9686 ret = btrfs_add_nondir(trans, dir, dentry,
9687 inode, 0, index);
9688 if (ret)
9689 goto out;
9690
9691 ret = btrfs_update_inode(trans, root, inode);
9692 out:
9693 unlock_new_inode(inode);
9694 if (ret)
9695 inode_dec_link_count(inode);
9696 iput(inode);
9697
9698 return ret;
9699 }
9700
9701 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9702 struct inode *new_dir, struct dentry *new_dentry,
9703 unsigned int flags)
9704 {
9705 struct btrfs_trans_handle *trans;
9706 unsigned int trans_num_items;
9707 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9708 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9709 struct inode *new_inode = d_inode(new_dentry);
9710 struct inode *old_inode = d_inode(old_dentry);
9711 u64 index = 0;
9712 u64 root_objectid;
9713 int ret;
9714 u64 old_ino = btrfs_ino(old_inode);
9715 bool log_pinned = false;
9716
9717 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9718 return -EPERM;
9719
9720 /* we only allow rename subvolume link between subvolumes */
9721 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9722 return -EXDEV;
9723
9724 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9725 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
9726 return -ENOTEMPTY;
9727
9728 if (S_ISDIR(old_inode->i_mode) && new_inode &&
9729 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9730 return -ENOTEMPTY;
9731
9732
9733 /* check for collisions, even if the name isn't there */
9734 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9735 new_dentry->d_name.name,
9736 new_dentry->d_name.len);
9737
9738 if (ret) {
9739 if (ret == -EEXIST) {
9740 /* we shouldn't get
9741 * eexist without a new_inode */
9742 if (WARN_ON(!new_inode)) {
9743 return ret;
9744 }
9745 } else {
9746 /* maybe -EOVERFLOW */
9747 return ret;
9748 }
9749 }
9750 ret = 0;
9751
9752 /*
9753 * we're using rename to replace one file with another. Start IO on it
9754 * now so we don't add too much work to the end of the transaction
9755 */
9756 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9757 filemap_flush(old_inode->i_mapping);
9758
9759 /* close the racy window with snapshot create/destroy ioctl */
9760 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9761 down_read(&root->fs_info->subvol_sem);
9762 /*
9763 * We want to reserve the absolute worst case amount of items. So if
9764 * both inodes are subvols and we need to unlink them then that would
9765 * require 4 item modifications, but if they are both normal inodes it
9766 * would require 5 item modifications, so we'll assume they are normal
9767 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
9768 * should cover the worst case number of items we'll modify.
9769 * If our rename has the whiteout flag, we need more 5 units for the
9770 * new inode (1 inode item, 1 inode ref, 2 dir items and 1 xattr item
9771 * when selinux is enabled).
9772 */
9773 trans_num_items = 11;
9774 if (flags & RENAME_WHITEOUT)
9775 trans_num_items += 5;
9776 trans = btrfs_start_transaction(root, trans_num_items);
9777 if (IS_ERR(trans)) {
9778 ret = PTR_ERR(trans);
9779 goto out_notrans;
9780 }
9781
9782 if (dest != root)
9783 btrfs_record_root_in_trans(trans, dest);
9784
9785 ret = btrfs_set_inode_index(new_dir, &index);
9786 if (ret)
9787 goto out_fail;
9788
9789 BTRFS_I(old_inode)->dir_index = 0ULL;
9790 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9791 /* force full log commit if subvolume involved. */
9792 btrfs_set_log_full_commit(root->fs_info, trans);
9793 } else {
9794 btrfs_pin_log_trans(root);
9795 log_pinned = true;
9796 ret = btrfs_insert_inode_ref(trans, dest,
9797 new_dentry->d_name.name,
9798 new_dentry->d_name.len,
9799 old_ino,
9800 btrfs_ino(new_dir), index);
9801 if (ret)
9802 goto out_fail;
9803 }
9804
9805 inode_inc_iversion(old_dir);
9806 inode_inc_iversion(new_dir);
9807 inode_inc_iversion(old_inode);
9808 old_dir->i_ctime = old_dir->i_mtime =
9809 new_dir->i_ctime = new_dir->i_mtime =
9810 old_inode->i_ctime = current_fs_time(old_dir->i_sb);
9811
9812 if (old_dentry->d_parent != new_dentry->d_parent)
9813 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
9814
9815 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9816 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9817 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
9818 old_dentry->d_name.name,
9819 old_dentry->d_name.len);
9820 } else {
9821 ret = __btrfs_unlink_inode(trans, root, old_dir,
9822 d_inode(old_dentry),
9823 old_dentry->d_name.name,
9824 old_dentry->d_name.len);
9825 if (!ret)
9826 ret = btrfs_update_inode(trans, root, old_inode);
9827 }
9828 if (ret) {
9829 btrfs_abort_transaction(trans, root, ret);
9830 goto out_fail;
9831 }
9832
9833 if (new_inode) {
9834 inode_inc_iversion(new_inode);
9835 new_inode->i_ctime = current_fs_time(new_inode->i_sb);
9836 if (unlikely(btrfs_ino(new_inode) ==
9837 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
9838 root_objectid = BTRFS_I(new_inode)->location.objectid;
9839 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9840 root_objectid,
9841 new_dentry->d_name.name,
9842 new_dentry->d_name.len);
9843 BUG_ON(new_inode->i_nlink == 0);
9844 } else {
9845 ret = btrfs_unlink_inode(trans, dest, new_dir,
9846 d_inode(new_dentry),
9847 new_dentry->d_name.name,
9848 new_dentry->d_name.len);
9849 }
9850 if (!ret && new_inode->i_nlink == 0)
9851 ret = btrfs_orphan_add(trans, d_inode(new_dentry));
9852 if (ret) {
9853 btrfs_abort_transaction(trans, root, ret);
9854 goto out_fail;
9855 }
9856 }
9857
9858 ret = btrfs_add_link(trans, new_dir, old_inode,
9859 new_dentry->d_name.name,
9860 new_dentry->d_name.len, 0, index);
9861 if (ret) {
9862 btrfs_abort_transaction(trans, root, ret);
9863 goto out_fail;
9864 }
9865
9866 if (old_inode->i_nlink == 1)
9867 BTRFS_I(old_inode)->dir_index = index;
9868
9869 if (log_pinned) {
9870 struct dentry *parent = new_dentry->d_parent;
9871
9872 btrfs_log_new_name(trans, old_inode, old_dir, parent);
9873 btrfs_end_log_trans(root);
9874 log_pinned = false;
9875 }
9876
9877 if (flags & RENAME_WHITEOUT) {
9878 ret = btrfs_whiteout_for_rename(trans, root, old_dir,
9879 old_dentry);
9880
9881 if (ret) {
9882 btrfs_abort_transaction(trans, root, ret);
9883 goto out_fail;
9884 }
9885 }
9886 out_fail:
9887 /*
9888 * If we have pinned the log and an error happened, we unpin tasks
9889 * trying to sync the log and force them to fallback to a transaction
9890 * commit if the log currently contains any of the inodes involved in
9891 * this rename operation (to ensure we do not persist a log with an
9892 * inconsistent state for any of these inodes or leading to any
9893 * inconsistencies when replayed). If the transaction was aborted, the
9894 * abortion reason is propagated to userspace when attempting to commit
9895 * the transaction. If the log does not contain any of these inodes, we
9896 * allow the tasks to sync it.
9897 */
9898 if (ret && log_pinned) {
9899 if (btrfs_inode_in_log(old_dir, root->fs_info->generation) ||
9900 btrfs_inode_in_log(new_dir, root->fs_info->generation) ||
9901 btrfs_inode_in_log(old_inode, root->fs_info->generation) ||
9902 (new_inode &&
9903 btrfs_inode_in_log(new_inode, root->fs_info->generation)))
9904 btrfs_set_log_full_commit(root->fs_info, trans);
9905
9906 btrfs_end_log_trans(root);
9907 log_pinned = false;
9908 }
9909 btrfs_end_transaction(trans, root);
9910 out_notrans:
9911 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9912 up_read(&root->fs_info->subvol_sem);
9913
9914 return ret;
9915 }
9916
9917 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
9918 struct inode *new_dir, struct dentry *new_dentry,
9919 unsigned int flags)
9920 {
9921 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
9922 return -EINVAL;
9923
9924 if (flags & RENAME_EXCHANGE)
9925 return btrfs_rename_exchange(old_dir, old_dentry, new_dir,
9926 new_dentry);
9927
9928 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
9929 }
9930
9931 static void btrfs_run_delalloc_work(struct btrfs_work *work)
9932 {
9933 struct btrfs_delalloc_work *delalloc_work;
9934 struct inode *inode;
9935
9936 delalloc_work = container_of(work, struct btrfs_delalloc_work,
9937 work);
9938 inode = delalloc_work->inode;
9939 filemap_flush(inode->i_mapping);
9940 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
9941 &BTRFS_I(inode)->runtime_flags))
9942 filemap_flush(inode->i_mapping);
9943
9944 if (delalloc_work->delay_iput)
9945 btrfs_add_delayed_iput(inode);
9946 else
9947 iput(inode);
9948 complete(&delalloc_work->completion);
9949 }
9950
9951 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
9952 int delay_iput)
9953 {
9954 struct btrfs_delalloc_work *work;
9955
9956 work = kmalloc(sizeof(*work), GFP_NOFS);
9957 if (!work)
9958 return NULL;
9959
9960 init_completion(&work->completion);
9961 INIT_LIST_HEAD(&work->list);
9962 work->inode = inode;
9963 work->delay_iput = delay_iput;
9964 WARN_ON_ONCE(!inode);
9965 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
9966 btrfs_run_delalloc_work, NULL, NULL);
9967
9968 return work;
9969 }
9970
9971 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
9972 {
9973 wait_for_completion(&work->completion);
9974 kfree(work);
9975 }
9976
9977 /*
9978 * some fairly slow code that needs optimization. This walks the list
9979 * of all the inodes with pending delalloc and forces them to disk.
9980 */
9981 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
9982 int nr)
9983 {
9984 struct btrfs_inode *binode;
9985 struct inode *inode;
9986 struct btrfs_delalloc_work *work, *next;
9987 struct list_head works;
9988 struct list_head splice;
9989 int ret = 0;
9990
9991 INIT_LIST_HEAD(&works);
9992 INIT_LIST_HEAD(&splice);
9993
9994 mutex_lock(&root->delalloc_mutex);
9995 spin_lock(&root->delalloc_lock);
9996 list_splice_init(&root->delalloc_inodes, &splice);
9997 while (!list_empty(&splice)) {
9998 binode = list_entry(splice.next, struct btrfs_inode,
9999 delalloc_inodes);
10000
10001 list_move_tail(&binode->delalloc_inodes,
10002 &root->delalloc_inodes);
10003 inode = igrab(&binode->vfs_inode);
10004 if (!inode) {
10005 cond_resched_lock(&root->delalloc_lock);
10006 continue;
10007 }
10008 spin_unlock(&root->delalloc_lock);
10009
10010 work = btrfs_alloc_delalloc_work(inode, delay_iput);
10011 if (!work) {
10012 if (delay_iput)
10013 btrfs_add_delayed_iput(inode);
10014 else
10015 iput(inode);
10016 ret = -ENOMEM;
10017 goto out;
10018 }
10019 list_add_tail(&work->list, &works);
10020 btrfs_queue_work(root->fs_info->flush_workers,
10021 &work->work);
10022 ret++;
10023 if (nr != -1 && ret >= nr)
10024 goto out;
10025 cond_resched();
10026 spin_lock(&root->delalloc_lock);
10027 }
10028 spin_unlock(&root->delalloc_lock);
10029
10030 out:
10031 list_for_each_entry_safe(work, next, &works, list) {
10032 list_del_init(&work->list);
10033 btrfs_wait_and_free_delalloc_work(work);
10034 }
10035
10036 if (!list_empty_careful(&splice)) {
10037 spin_lock(&root->delalloc_lock);
10038 list_splice_tail(&splice, &root->delalloc_inodes);
10039 spin_unlock(&root->delalloc_lock);
10040 }
10041 mutex_unlock(&root->delalloc_mutex);
10042 return ret;
10043 }
10044
10045 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
10046 {
10047 int ret;
10048
10049 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
10050 return -EROFS;
10051
10052 ret = __start_delalloc_inodes(root, delay_iput, -1);
10053 if (ret > 0)
10054 ret = 0;
10055 /*
10056 * the filemap_flush will queue IO into the worker threads, but
10057 * we have to make sure the IO is actually started and that
10058 * ordered extents get created before we return
10059 */
10060 atomic_inc(&root->fs_info->async_submit_draining);
10061 while (atomic_read(&root->fs_info->nr_async_submits) ||
10062 atomic_read(&root->fs_info->async_delalloc_pages)) {
10063 wait_event(root->fs_info->async_submit_wait,
10064 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
10065 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
10066 }
10067 atomic_dec(&root->fs_info->async_submit_draining);
10068 return ret;
10069 }
10070
10071 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
10072 int nr)
10073 {
10074 struct btrfs_root *root;
10075 struct list_head splice;
10076 int ret;
10077
10078 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10079 return -EROFS;
10080
10081 INIT_LIST_HEAD(&splice);
10082
10083 mutex_lock(&fs_info->delalloc_root_mutex);
10084 spin_lock(&fs_info->delalloc_root_lock);
10085 list_splice_init(&fs_info->delalloc_roots, &splice);
10086 while (!list_empty(&splice) && nr) {
10087 root = list_first_entry(&splice, struct btrfs_root,
10088 delalloc_root);
10089 root = btrfs_grab_fs_root(root);
10090 BUG_ON(!root);
10091 list_move_tail(&root->delalloc_root,
10092 &fs_info->delalloc_roots);
10093 spin_unlock(&fs_info->delalloc_root_lock);
10094
10095 ret = __start_delalloc_inodes(root, delay_iput, nr);
10096 btrfs_put_fs_root(root);
10097 if (ret < 0)
10098 goto out;
10099
10100 if (nr != -1) {
10101 nr -= ret;
10102 WARN_ON(nr < 0);
10103 }
10104 spin_lock(&fs_info->delalloc_root_lock);
10105 }
10106 spin_unlock(&fs_info->delalloc_root_lock);
10107
10108 ret = 0;
10109 atomic_inc(&fs_info->async_submit_draining);
10110 while (atomic_read(&fs_info->nr_async_submits) ||
10111 atomic_read(&fs_info->async_delalloc_pages)) {
10112 wait_event(fs_info->async_submit_wait,
10113 (atomic_read(&fs_info->nr_async_submits) == 0 &&
10114 atomic_read(&fs_info->async_delalloc_pages) == 0));
10115 }
10116 atomic_dec(&fs_info->async_submit_draining);
10117 out:
10118 if (!list_empty_careful(&splice)) {
10119 spin_lock(&fs_info->delalloc_root_lock);
10120 list_splice_tail(&splice, &fs_info->delalloc_roots);
10121 spin_unlock(&fs_info->delalloc_root_lock);
10122 }
10123 mutex_unlock(&fs_info->delalloc_root_mutex);
10124 return ret;
10125 }
10126
10127 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
10128 const char *symname)
10129 {
10130 struct btrfs_trans_handle *trans;
10131 struct btrfs_root *root = BTRFS_I(dir)->root;
10132 struct btrfs_path *path;
10133 struct btrfs_key key;
10134 struct inode *inode = NULL;
10135 int err;
10136 int drop_inode = 0;
10137 u64 objectid;
10138 u64 index = 0;
10139 int name_len;
10140 int datasize;
10141 unsigned long ptr;
10142 struct btrfs_file_extent_item *ei;
10143 struct extent_buffer *leaf;
10144
10145 name_len = strlen(symname);
10146 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
10147 return -ENAMETOOLONG;
10148
10149 /*
10150 * 2 items for inode item and ref
10151 * 2 items for dir items
10152 * 1 item for updating parent inode item
10153 * 1 item for the inline extent item
10154 * 1 item for xattr if selinux is on
10155 */
10156 trans = btrfs_start_transaction(root, 7);
10157 if (IS_ERR(trans))
10158 return PTR_ERR(trans);
10159
10160 err = btrfs_find_free_ino(root, &objectid);
10161 if (err)
10162 goto out_unlock;
10163
10164 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
10165 dentry->d_name.len, btrfs_ino(dir), objectid,
10166 S_IFLNK|S_IRWXUGO, &index);
10167 if (IS_ERR(inode)) {
10168 err = PTR_ERR(inode);
10169 goto out_unlock;
10170 }
10171
10172 /*
10173 * If the active LSM wants to access the inode during
10174 * d_instantiate it needs these. Smack checks to see
10175 * if the filesystem supports xattrs by looking at the
10176 * ops vector.
10177 */
10178 inode->i_fop = &btrfs_file_operations;
10179 inode->i_op = &btrfs_file_inode_operations;
10180 inode->i_mapping->a_ops = &btrfs_aops;
10181 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10182
10183 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
10184 if (err)
10185 goto out_unlock_inode;
10186
10187 path = btrfs_alloc_path();
10188 if (!path) {
10189 err = -ENOMEM;
10190 goto out_unlock_inode;
10191 }
10192 key.objectid = btrfs_ino(inode);
10193 key.offset = 0;
10194 key.type = BTRFS_EXTENT_DATA_KEY;
10195 datasize = btrfs_file_extent_calc_inline_size(name_len);
10196 err = btrfs_insert_empty_item(trans, root, path, &key,
10197 datasize);
10198 if (err) {
10199 btrfs_free_path(path);
10200 goto out_unlock_inode;
10201 }
10202 leaf = path->nodes[0];
10203 ei = btrfs_item_ptr(leaf, path->slots[0],
10204 struct btrfs_file_extent_item);
10205 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
10206 btrfs_set_file_extent_type(leaf, ei,
10207 BTRFS_FILE_EXTENT_INLINE);
10208 btrfs_set_file_extent_encryption(leaf, ei, 0);
10209 btrfs_set_file_extent_compression(leaf, ei, 0);
10210 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
10211 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
10212
10213 ptr = btrfs_file_extent_inline_start(ei);
10214 write_extent_buffer(leaf, symname, ptr, name_len);
10215 btrfs_mark_buffer_dirty(leaf);
10216 btrfs_free_path(path);
10217
10218 inode->i_op = &btrfs_symlink_inode_operations;
10219 inode_nohighmem(inode);
10220 inode->i_mapping->a_ops = &btrfs_symlink_aops;
10221 inode_set_bytes(inode, name_len);
10222 btrfs_i_size_write(inode, name_len);
10223 err = btrfs_update_inode(trans, root, inode);
10224 /*
10225 * Last step, add directory indexes for our symlink inode. This is the
10226 * last step to avoid extra cleanup of these indexes if an error happens
10227 * elsewhere above.
10228 */
10229 if (!err)
10230 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
10231 if (err) {
10232 drop_inode = 1;
10233 goto out_unlock_inode;
10234 }
10235
10236 unlock_new_inode(inode);
10237 d_instantiate(dentry, inode);
10238
10239 out_unlock:
10240 btrfs_end_transaction(trans, root);
10241 if (drop_inode) {
10242 inode_dec_link_count(inode);
10243 iput(inode);
10244 }
10245 btrfs_btree_balance_dirty(root);
10246 return err;
10247
10248 out_unlock_inode:
10249 drop_inode = 1;
10250 unlock_new_inode(inode);
10251 goto out_unlock;
10252 }
10253
10254 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
10255 u64 start, u64 num_bytes, u64 min_size,
10256 loff_t actual_len, u64 *alloc_hint,
10257 struct btrfs_trans_handle *trans)
10258 {
10259 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
10260 struct extent_map *em;
10261 struct btrfs_root *root = BTRFS_I(inode)->root;
10262 struct btrfs_key ins;
10263 u64 cur_offset = start;
10264 u64 i_size;
10265 u64 cur_bytes;
10266 u64 last_alloc = (u64)-1;
10267 int ret = 0;
10268 bool own_trans = true;
10269
10270 if (trans)
10271 own_trans = false;
10272 while (num_bytes > 0) {
10273 if (own_trans) {
10274 trans = btrfs_start_transaction(root, 3);
10275 if (IS_ERR(trans)) {
10276 ret = PTR_ERR(trans);
10277 break;
10278 }
10279 }
10280
10281 cur_bytes = min_t(u64, num_bytes, SZ_256M);
10282 cur_bytes = max(cur_bytes, min_size);
10283 /*
10284 * If we are severely fragmented we could end up with really
10285 * small allocations, so if the allocator is returning small
10286 * chunks lets make its job easier by only searching for those
10287 * sized chunks.
10288 */
10289 cur_bytes = min(cur_bytes, last_alloc);
10290 ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0,
10291 *alloc_hint, &ins, 1, 0);
10292 if (ret) {
10293 if (own_trans)
10294 btrfs_end_transaction(trans, root);
10295 break;
10296 }
10297 btrfs_dec_block_group_reservations(root->fs_info, ins.objectid);
10298
10299 last_alloc = ins.offset;
10300 ret = insert_reserved_file_extent(trans, inode,
10301 cur_offset, ins.objectid,
10302 ins.offset, ins.offset,
10303 ins.offset, 0, 0, 0,
10304 BTRFS_FILE_EXTENT_PREALLOC);
10305 if (ret) {
10306 btrfs_free_reserved_extent(root, ins.objectid,
10307 ins.offset, 0);
10308 btrfs_abort_transaction(trans, root, ret);
10309 if (own_trans)
10310 btrfs_end_transaction(trans, root);
10311 break;
10312 }
10313
10314 btrfs_drop_extent_cache(inode, cur_offset,
10315 cur_offset + ins.offset -1, 0);
10316
10317 em = alloc_extent_map();
10318 if (!em) {
10319 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
10320 &BTRFS_I(inode)->runtime_flags);
10321 goto next;
10322 }
10323
10324 em->start = cur_offset;
10325 em->orig_start = cur_offset;
10326 em->len = ins.offset;
10327 em->block_start = ins.objectid;
10328 em->block_len = ins.offset;
10329 em->orig_block_len = ins.offset;
10330 em->ram_bytes = ins.offset;
10331 em->bdev = root->fs_info->fs_devices->latest_bdev;
10332 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
10333 em->generation = trans->transid;
10334
10335 while (1) {
10336 write_lock(&em_tree->lock);
10337 ret = add_extent_mapping(em_tree, em, 1);
10338 write_unlock(&em_tree->lock);
10339 if (ret != -EEXIST)
10340 break;
10341 btrfs_drop_extent_cache(inode, cur_offset,
10342 cur_offset + ins.offset - 1,
10343 0);
10344 }
10345 free_extent_map(em);
10346 next:
10347 num_bytes -= ins.offset;
10348 cur_offset += ins.offset;
10349 *alloc_hint = ins.objectid + ins.offset;
10350
10351 inode_inc_iversion(inode);
10352 inode->i_ctime = current_fs_time(inode->i_sb);
10353 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
10354 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
10355 (actual_len > inode->i_size) &&
10356 (cur_offset > inode->i_size)) {
10357 if (cur_offset > actual_len)
10358 i_size = actual_len;
10359 else
10360 i_size = cur_offset;
10361 i_size_write(inode, i_size);
10362 btrfs_ordered_update_i_size(inode, i_size, NULL);
10363 }
10364
10365 ret = btrfs_update_inode(trans, root, inode);
10366
10367 if (ret) {
10368 btrfs_abort_transaction(trans, root, ret);
10369 if (own_trans)
10370 btrfs_end_transaction(trans, root);
10371 break;
10372 }
10373
10374 if (own_trans)
10375 btrfs_end_transaction(trans, root);
10376 }
10377 return ret;
10378 }
10379
10380 int btrfs_prealloc_file_range(struct inode *inode, int mode,
10381 u64 start, u64 num_bytes, u64 min_size,
10382 loff_t actual_len, u64 *alloc_hint)
10383 {
10384 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10385 min_size, actual_len, alloc_hint,
10386 NULL);
10387 }
10388
10389 int btrfs_prealloc_file_range_trans(struct inode *inode,
10390 struct btrfs_trans_handle *trans, int mode,
10391 u64 start, u64 num_bytes, u64 min_size,
10392 loff_t actual_len, u64 *alloc_hint)
10393 {
10394 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10395 min_size, actual_len, alloc_hint, trans);
10396 }
10397
10398 static int btrfs_set_page_dirty(struct page *page)
10399 {
10400 return __set_page_dirty_nobuffers(page);
10401 }
10402
10403 static int btrfs_permission(struct inode *inode, int mask)
10404 {
10405 struct btrfs_root *root = BTRFS_I(inode)->root;
10406 umode_t mode = inode->i_mode;
10407
10408 if (mask & MAY_WRITE &&
10409 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
10410 if (btrfs_root_readonly(root))
10411 return -EROFS;
10412 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
10413 return -EACCES;
10414 }
10415 return generic_permission(inode, mask);
10416 }
10417
10418 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
10419 {
10420 struct btrfs_trans_handle *trans;
10421 struct btrfs_root *root = BTRFS_I(dir)->root;
10422 struct inode *inode = NULL;
10423 u64 objectid;
10424 u64 index;
10425 int ret = 0;
10426
10427 /*
10428 * 5 units required for adding orphan entry
10429 */
10430 trans = btrfs_start_transaction(root, 5);
10431 if (IS_ERR(trans))
10432 return PTR_ERR(trans);
10433
10434 ret = btrfs_find_free_ino(root, &objectid);
10435 if (ret)
10436 goto out;
10437
10438 inode = btrfs_new_inode(trans, root, dir, NULL, 0,
10439 btrfs_ino(dir), objectid, mode, &index);
10440 if (IS_ERR(inode)) {
10441 ret = PTR_ERR(inode);
10442 inode = NULL;
10443 goto out;
10444 }
10445
10446 inode->i_fop = &btrfs_file_operations;
10447 inode->i_op = &btrfs_file_inode_operations;
10448
10449 inode->i_mapping->a_ops = &btrfs_aops;
10450 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10451
10452 ret = btrfs_init_inode_security(trans, inode, dir, NULL);
10453 if (ret)
10454 goto out_inode;
10455
10456 ret = btrfs_update_inode(trans, root, inode);
10457 if (ret)
10458 goto out_inode;
10459 ret = btrfs_orphan_add(trans, inode);
10460 if (ret)
10461 goto out_inode;
10462
10463 /*
10464 * We set number of links to 0 in btrfs_new_inode(), and here we set
10465 * it to 1 because d_tmpfile() will issue a warning if the count is 0,
10466 * through:
10467 *
10468 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
10469 */
10470 set_nlink(inode, 1);
10471 unlock_new_inode(inode);
10472 d_tmpfile(dentry, inode);
10473 mark_inode_dirty(inode);
10474
10475 out:
10476 btrfs_end_transaction(trans, root);
10477 if (ret)
10478 iput(inode);
10479 btrfs_balance_delayed_items(root);
10480 btrfs_btree_balance_dirty(root);
10481 return ret;
10482
10483 out_inode:
10484 unlock_new_inode(inode);
10485 goto out;
10486
10487 }
10488
10489 /* Inspired by filemap_check_errors() */
10490 int btrfs_inode_check_errors(struct inode *inode)
10491 {
10492 int ret = 0;
10493
10494 if (test_bit(AS_ENOSPC, &inode->i_mapping->flags) &&
10495 test_and_clear_bit(AS_ENOSPC, &inode->i_mapping->flags))
10496 ret = -ENOSPC;
10497 if (test_bit(AS_EIO, &inode->i_mapping->flags) &&
10498 test_and_clear_bit(AS_EIO, &inode->i_mapping->flags))
10499 ret = -EIO;
10500
10501 return ret;
10502 }
10503
10504 static const struct inode_operations btrfs_dir_inode_operations = {
10505 .getattr = btrfs_getattr,
10506 .lookup = btrfs_lookup,
10507 .create = btrfs_create,
10508 .unlink = btrfs_unlink,
10509 .link = btrfs_link,
10510 .mkdir = btrfs_mkdir,
10511 .rmdir = btrfs_rmdir,
10512 .rename2 = btrfs_rename2,
10513 .symlink = btrfs_symlink,
10514 .setattr = btrfs_setattr,
10515 .mknod = btrfs_mknod,
10516 .setxattr = generic_setxattr,
10517 .getxattr = generic_getxattr,
10518 .listxattr = btrfs_listxattr,
10519 .removexattr = generic_removexattr,
10520 .permission = btrfs_permission,
10521 .get_acl = btrfs_get_acl,
10522 .set_acl = btrfs_set_acl,
10523 .update_time = btrfs_update_time,
10524 .tmpfile = btrfs_tmpfile,
10525 };
10526 static const struct inode_operations btrfs_dir_ro_inode_operations = {
10527 .lookup = btrfs_lookup,
10528 .permission = btrfs_permission,
10529 .get_acl = btrfs_get_acl,
10530 .set_acl = btrfs_set_acl,
10531 .update_time = btrfs_update_time,
10532 };
10533
10534 static const struct file_operations btrfs_dir_file_operations = {
10535 .llseek = generic_file_llseek,
10536 .read = generic_read_dir,
10537 .iterate = btrfs_real_readdir,
10538 .unlocked_ioctl = btrfs_ioctl,
10539 #ifdef CONFIG_COMPAT
10540 .compat_ioctl = btrfs_compat_ioctl,
10541 #endif
10542 .release = btrfs_release_file,
10543 .fsync = btrfs_sync_file,
10544 };
10545
10546 static const struct extent_io_ops btrfs_extent_io_ops = {
10547 .fill_delalloc = run_delalloc_range,
10548 .submit_bio_hook = btrfs_submit_bio_hook,
10549 .merge_bio_hook = btrfs_merge_bio_hook,
10550 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
10551 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
10552 .writepage_start_hook = btrfs_writepage_start_hook,
10553 .set_bit_hook = btrfs_set_bit_hook,
10554 .clear_bit_hook = btrfs_clear_bit_hook,
10555 .merge_extent_hook = btrfs_merge_extent_hook,
10556 .split_extent_hook = btrfs_split_extent_hook,
10557 };
10558
10559 /*
10560 * btrfs doesn't support the bmap operation because swapfiles
10561 * use bmap to make a mapping of extents in the file. They assume
10562 * these extents won't change over the life of the file and they
10563 * use the bmap result to do IO directly to the drive.
10564 *
10565 * the btrfs bmap call would return logical addresses that aren't
10566 * suitable for IO and they also will change frequently as COW
10567 * operations happen. So, swapfile + btrfs == corruption.
10568 *
10569 * For now we're avoiding this by dropping bmap.
10570 */
10571 static const struct address_space_operations btrfs_aops = {
10572 .readpage = btrfs_readpage,
10573 .writepage = btrfs_writepage,
10574 .writepages = btrfs_writepages,
10575 .readpages = btrfs_readpages,
10576 .direct_IO = btrfs_direct_IO,
10577 .invalidatepage = btrfs_invalidatepage,
10578 .releasepage = btrfs_releasepage,
10579 .set_page_dirty = btrfs_set_page_dirty,
10580 .error_remove_page = generic_error_remove_page,
10581 };
10582
10583 static const struct address_space_operations btrfs_symlink_aops = {
10584 .readpage = btrfs_readpage,
10585 .writepage = btrfs_writepage,
10586 .invalidatepage = btrfs_invalidatepage,
10587 .releasepage = btrfs_releasepage,
10588 };
10589
10590 static const struct inode_operations btrfs_file_inode_operations = {
10591 .getattr = btrfs_getattr,
10592 .setattr = btrfs_setattr,
10593 .setxattr = generic_setxattr,
10594 .getxattr = generic_getxattr,
10595 .listxattr = btrfs_listxattr,
10596 .removexattr = generic_removexattr,
10597 .permission = btrfs_permission,
10598 .fiemap = btrfs_fiemap,
10599 .get_acl = btrfs_get_acl,
10600 .set_acl = btrfs_set_acl,
10601 .update_time = btrfs_update_time,
10602 };
10603 static const struct inode_operations btrfs_special_inode_operations = {
10604 .getattr = btrfs_getattr,
10605 .setattr = btrfs_setattr,
10606 .permission = btrfs_permission,
10607 .setxattr = generic_setxattr,
10608 .getxattr = generic_getxattr,
10609 .listxattr = btrfs_listxattr,
10610 .removexattr = generic_removexattr,
10611 .get_acl = btrfs_get_acl,
10612 .set_acl = btrfs_set_acl,
10613 .update_time = btrfs_update_time,
10614 };
10615 static const struct inode_operations btrfs_symlink_inode_operations = {
10616 .readlink = generic_readlink,
10617 .get_link = page_get_link,
10618 .getattr = btrfs_getattr,
10619 .setattr = btrfs_setattr,
10620 .permission = btrfs_permission,
10621 .setxattr = generic_setxattr,
10622 .getxattr = generic_getxattr,
10623 .listxattr = btrfs_listxattr,
10624 .removexattr = generic_removexattr,
10625 .update_time = btrfs_update_time,
10626 };
10627
10628 const struct dentry_operations btrfs_dentry_operations = {
10629 .d_delete = btrfs_dentry_delete,
10630 .d_release = btrfs_dentry_release,
10631 };
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