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