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Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux/fpc-iii.git] / fs / btrfs / inode.c
blobd3d44486290bf6c8dce015ec24f440874ceb6d67
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/pagemap.h>
25 #include <linux/highmem.h>
26 #include <linux/time.h>
27 #include <linux/init.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mpage.h>
31 #include <linux/swap.h>
32 #include <linux/writeback.h>
33 #include <linux/statfs.h>
34 #include <linux/compat.h>
35 #include <linux/aio.h>
36 #include <linux/bit_spinlock.h>
37 #include <linux/xattr.h>
38 #include <linux/posix_acl.h>
39 #include <linux/falloc.h>
40 #include <linux/slab.h>
41 #include <linux/ratelimit.h>
42 #include <linux/mount.h>
43 #include <linux/btrfs.h>
44 #include <linux/blkdev.h>
45 #include <linux/posix_acl_xattr.h>
46 #include "ctree.h"
47 #include "disk-io.h"
48 #include "transaction.h"
49 #include "btrfs_inode.h"
50 #include "print-tree.h"
51 #include "ordered-data.h"
52 #include "xattr.h"
53 #include "tree-log.h"
54 #include "volumes.h"
55 #include "compression.h"
56 #include "locking.h"
57 #include "free-space-cache.h"
58 #include "inode-map.h"
59 #include "backref.h"
60 #include "hash.h"
61 #include "props.h"
62
63 struct btrfs_iget_args {
64 struct btrfs_key *location;
65 struct btrfs_root *root;
66 };
67
68 static const struct inode_operations btrfs_dir_inode_operations;
69 static const struct inode_operations btrfs_symlink_inode_operations;
70 static const struct inode_operations btrfs_dir_ro_inode_operations;
71 static const struct inode_operations btrfs_special_inode_operations;
72 static const struct inode_operations btrfs_file_inode_operations;
73 static const struct address_space_operations btrfs_aops;
74 static const struct address_space_operations btrfs_symlink_aops;
75 static const struct file_operations btrfs_dir_file_operations;
76 static struct extent_io_ops btrfs_extent_io_ops;
77
78 static struct kmem_cache *btrfs_inode_cachep;
79 static struct kmem_cache *btrfs_delalloc_work_cachep;
80 struct kmem_cache *btrfs_trans_handle_cachep;
81 struct kmem_cache *btrfs_transaction_cachep;
82 struct kmem_cache *btrfs_path_cachep;
83 struct kmem_cache *btrfs_free_space_cachep;
84
85 #define S_SHIFT 12
86 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
87 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
88 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
89 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
90 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
91 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
92 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
93 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
94 };
95
96 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
97 static int btrfs_truncate(struct inode *inode);
98 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
99 static noinline int cow_file_range(struct inode *inode,
100 struct page *locked_page,
101 u64 start, u64 end, int *page_started,
102 unsigned long *nr_written, int unlock);
103 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
104 u64 len, u64 orig_start,
105 u64 block_start, u64 block_len,
106 u64 orig_block_len, u64 ram_bytes,
107 int type);
108
109 static int btrfs_dirty_inode(struct inode *inode);
110
111 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
112 struct inode *inode, struct inode *dir,
113 const struct qstr *qstr)
114 {
115 int err;
116
117 err = btrfs_init_acl(trans, inode, dir);
118 if (!err)
119 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
120 return err;
121 }
122
123 /*
124 * this does all the hard work for inserting an inline extent into
125 * the btree. The caller should have done a btrfs_drop_extents so that
126 * no overlapping inline items exist in the btree
127 */
128 static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
129 struct btrfs_path *path, int extent_inserted,
130 struct btrfs_root *root, struct inode *inode,
131 u64 start, size_t size, size_t compressed_size,
132 int compress_type,
133 struct page **compressed_pages)
134 {
135 struct extent_buffer *leaf;
136 struct page *page = NULL;
137 char *kaddr;
138 unsigned long ptr;
139 struct btrfs_file_extent_item *ei;
140 int err = 0;
141 int ret;
142 size_t cur_size = size;
143 unsigned long offset;
144
145 if (compressed_size && compressed_pages)
146 cur_size = compressed_size;
147
148 inode_add_bytes(inode, size);
149
150 if (!extent_inserted) {
151 struct btrfs_key key;
152 size_t datasize;
153
154 key.objectid = btrfs_ino(inode);
155 key.offset = start;
156 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
157
158 datasize = btrfs_file_extent_calc_inline_size(cur_size);
159 path->leave_spinning = 1;
160 ret = btrfs_insert_empty_item(trans, root, path, &key,
161 datasize);
162 if (ret) {
163 err = ret;
164 goto fail;
165 }
166 }
167 leaf = path->nodes[0];
168 ei = btrfs_item_ptr(leaf, path->slots[0],
169 struct btrfs_file_extent_item);
170 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
171 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
172 btrfs_set_file_extent_encryption(leaf, ei, 0);
173 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
174 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
175 ptr = btrfs_file_extent_inline_start(ei);
176
177 if (compress_type != BTRFS_COMPRESS_NONE) {
178 struct page *cpage;
179 int i = 0;
180 while (compressed_size > 0) {
181 cpage = compressed_pages[i];
182 cur_size = min_t(unsigned long, compressed_size,
183 PAGE_CACHE_SIZE);
184
185 kaddr = kmap_atomic(cpage);
186 write_extent_buffer(leaf, kaddr, ptr, cur_size);
187 kunmap_atomic(kaddr);
188
189 i++;
190 ptr += cur_size;
191 compressed_size -= cur_size;
192 }
193 btrfs_set_file_extent_compression(leaf, ei,
194 compress_type);
195 } else {
196 page = find_get_page(inode->i_mapping,
197 start >> PAGE_CACHE_SHIFT);
198 btrfs_set_file_extent_compression(leaf, ei, 0);
199 kaddr = kmap_atomic(page);
200 offset = start & (PAGE_CACHE_SIZE - 1);
201 write_extent_buffer(leaf, kaddr + offset, ptr, size);
202 kunmap_atomic(kaddr);
203 page_cache_release(page);
204 }
205 btrfs_mark_buffer_dirty(leaf);
206 btrfs_release_path(path);
207
208 /*
209 * we're an inline extent, so nobody can
210 * extend the file past i_size without locking
211 * a page we already have locked.
212 *
213 * We must do any isize and inode updates
214 * before we unlock the pages. Otherwise we
215 * could end up racing with unlink.
216 */
217 BTRFS_I(inode)->disk_i_size = inode->i_size;
218 ret = btrfs_update_inode(trans, root, inode);
219
220 return ret;
221 fail:
222 return err;
223 }
224
225
226 /*
227 * conditionally insert an inline extent into the file. This
228 * does the checks required to make sure the data is small enough
229 * to fit as an inline extent.
230 */
231 static noinline int cow_file_range_inline(struct btrfs_root *root,
232 struct inode *inode, u64 start,
233 u64 end, size_t compressed_size,
234 int compress_type,
235 struct page **compressed_pages)
236 {
237 struct btrfs_trans_handle *trans;
238 u64 isize = i_size_read(inode);
239 u64 actual_end = min(end + 1, isize);
240 u64 inline_len = actual_end - start;
241 u64 aligned_end = ALIGN(end, root->sectorsize);
242 u64 data_len = inline_len;
243 int ret;
244 struct btrfs_path *path;
245 int extent_inserted = 0;
246 u32 extent_item_size;
247
248 if (compressed_size)
249 data_len = compressed_size;
250
251 if (start > 0 ||
252 actual_end >= PAGE_CACHE_SIZE ||
253 data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
254 (!compressed_size &&
255 (actual_end & (root->sectorsize - 1)) == 0) ||
256 end + 1 < isize ||
257 data_len > root->fs_info->max_inline) {
258 return 1;
259 }
260
261 path = btrfs_alloc_path();
262 if (!path)
263 return -ENOMEM;
264
265 trans = btrfs_join_transaction(root);
266 if (IS_ERR(trans)) {
267 btrfs_free_path(path);
268 return PTR_ERR(trans);
269 }
270 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
271
272 if (compressed_size && compressed_pages)
273 extent_item_size = btrfs_file_extent_calc_inline_size(
274 compressed_size);
275 else
276 extent_item_size = btrfs_file_extent_calc_inline_size(
277 inline_len);
278
279 ret = __btrfs_drop_extents(trans, root, inode, path,
280 start, aligned_end, NULL,
281 1, 1, extent_item_size, &extent_inserted);
282 if (ret) {
283 btrfs_abort_transaction(trans, root, ret);
284 goto out;
285 }
286
287 if (isize > actual_end)
288 inline_len = min_t(u64, isize, actual_end);
289 ret = insert_inline_extent(trans, path, extent_inserted,
290 root, inode, start,
291 inline_len, compressed_size,
292 compress_type, compressed_pages);
293 if (ret && ret != -ENOSPC) {
294 btrfs_abort_transaction(trans, root, ret);
295 goto out;
296 } else if (ret == -ENOSPC) {
297 ret = 1;
298 goto out;
299 }
300
301 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
302 btrfs_delalloc_release_metadata(inode, end + 1 - start);
303 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
304 out:
305 btrfs_free_path(path);
306 btrfs_end_transaction(trans, root);
307 return ret;
308 }
309
310 struct async_extent {
311 u64 start;
312 u64 ram_size;
313 u64 compressed_size;
314 struct page **pages;
315 unsigned long nr_pages;
316 int compress_type;
317 struct list_head list;
318 };
319
320 struct async_cow {
321 struct inode *inode;
322 struct btrfs_root *root;
323 struct page *locked_page;
324 u64 start;
325 u64 end;
326 struct list_head extents;
327 struct btrfs_work work;
328 };
329
330 static noinline int add_async_extent(struct async_cow *cow,
331 u64 start, u64 ram_size,
332 u64 compressed_size,
333 struct page **pages,
334 unsigned long nr_pages,
335 int compress_type)
336 {
337 struct async_extent *async_extent;
338
339 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
340 BUG_ON(!async_extent); /* -ENOMEM */
341 async_extent->start = start;
342 async_extent->ram_size = ram_size;
343 async_extent->compressed_size = compressed_size;
344 async_extent->pages = pages;
345 async_extent->nr_pages = nr_pages;
346 async_extent->compress_type = compress_type;
347 list_add_tail(&async_extent->list, &cow->extents);
348 return 0;
349 }
350
351 /*
352 * we create compressed extents in two phases. The first
353 * phase compresses a range of pages that have already been
354 * locked (both pages and state bits are locked).
355 *
356 * This is done inside an ordered work queue, and the compression
357 * is spread across many cpus. The actual IO submission is step
358 * two, and the ordered work queue takes care of making sure that
359 * happens in the same order things were put onto the queue by
360 * writepages and friends.
361 *
362 * If this code finds it can't get good compression, it puts an
363 * entry onto the work queue to write the uncompressed bytes. This
364 * makes sure that both compressed inodes and uncompressed inodes
365 * are written in the same order that the flusher thread sent them
366 * down.
367 */
368 static noinline int compress_file_range(struct inode *inode,
369 struct page *locked_page,
370 u64 start, u64 end,
371 struct async_cow *async_cow,
372 int *num_added)
373 {
374 struct btrfs_root *root = BTRFS_I(inode)->root;
375 u64 num_bytes;
376 u64 blocksize = root->sectorsize;
377 u64 actual_end;
378 u64 isize = i_size_read(inode);
379 int ret = 0;
380 struct page **pages = NULL;
381 unsigned long nr_pages;
382 unsigned long nr_pages_ret = 0;
383 unsigned long total_compressed = 0;
384 unsigned long total_in = 0;
385 unsigned long max_compressed = 128 * 1024;
386 unsigned long max_uncompressed = 128 * 1024;
387 int i;
388 int will_compress;
389 int compress_type = root->fs_info->compress_type;
390 int redirty = 0;
391
392 /* if this is a small write inside eof, kick off a defrag */
393 if ((end - start + 1) < 16 * 1024 &&
394 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
395 btrfs_add_inode_defrag(NULL, inode);
396
397 actual_end = min_t(u64, isize, end + 1);
398 again:
399 will_compress = 0;
400 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
401 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
402
403 /*
404 * we don't want to send crud past the end of i_size through
405 * compression, that's just a waste of CPU time. So, if the
406 * end of the file is before the start of our current
407 * requested range of bytes, we bail out to the uncompressed
408 * cleanup code that can deal with all of this.
409 *
410 * It isn't really the fastest way to fix things, but this is a
411 * very uncommon corner.
412 */
413 if (actual_end <= start)
414 goto cleanup_and_bail_uncompressed;
415
416 total_compressed = actual_end - start;
417
418 /* we want to make sure that amount of ram required to uncompress
419 * an extent is reasonable, so we limit the total size in ram
420 * of a compressed extent to 128k. This is a crucial number
421 * because it also controls how easily we can spread reads across
422 * cpus for decompression.
423 *
424 * We also want to make sure the amount of IO required to do
425 * a random read is reasonably small, so we limit the size of
426 * a compressed extent to 128k.
427 */
428 total_compressed = min(total_compressed, max_uncompressed);
429 num_bytes = ALIGN(end - start + 1, blocksize);
430 num_bytes = max(blocksize, num_bytes);
431 total_in = 0;
432 ret = 0;
433
434 /*
435 * we do compression for mount -o compress and when the
436 * inode has not been flagged as nocompress. This flag can
437 * change at any time if we discover bad compression ratios.
438 */
439 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) &&
440 (btrfs_test_opt(root, COMPRESS) ||
441 (BTRFS_I(inode)->force_compress) ||
442 (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) {
443 WARN_ON(pages);
444 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
445 if (!pages) {
446 /* just bail out to the uncompressed code */
447 goto cont;
448 }
449
450 if (BTRFS_I(inode)->force_compress)
451 compress_type = BTRFS_I(inode)->force_compress;
452
453 /*
454 * we need to call clear_page_dirty_for_io on each
455 * page in the range. Otherwise applications with the file
456 * mmap'd can wander in and change the page contents while
457 * we are compressing them.
458 *
459 * If the compression fails for any reason, we set the pages
460 * dirty again later on.
461 */
462 extent_range_clear_dirty_for_io(inode, start, end);
463 redirty = 1;
464 ret = btrfs_compress_pages(compress_type,
465 inode->i_mapping, start,
466 total_compressed, pages,
467 nr_pages, &nr_pages_ret,
468 &total_in,
469 &total_compressed,
470 max_compressed);
471
472 if (!ret) {
473 unsigned long offset = total_compressed &
474 (PAGE_CACHE_SIZE - 1);
475 struct page *page = pages[nr_pages_ret - 1];
476 char *kaddr;
477
478 /* zero the tail end of the last page, we might be
479 * sending it down to disk
480 */
481 if (offset) {
482 kaddr = kmap_atomic(page);
483 memset(kaddr + offset, 0,
484 PAGE_CACHE_SIZE - offset);
485 kunmap_atomic(kaddr);
486 }
487 will_compress = 1;
488 }
489 }
490 cont:
491 if (start == 0) {
492 /* lets try to make an inline extent */
493 if (ret || total_in < (actual_end - start)) {
494 /* we didn't compress the entire range, try
495 * to make an uncompressed inline extent.
496 */
497 ret = cow_file_range_inline(root, inode, start, end,
498 0, 0, NULL);
499 } else {
500 /* try making a compressed inline extent */
501 ret = cow_file_range_inline(root, inode, start, end,
502 total_compressed,
503 compress_type, pages);
504 }
505 if (ret <= 0) {
506 unsigned long clear_flags = EXTENT_DELALLOC |
507 EXTENT_DEFRAG;
508 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0;
509
510 /*
511 * inline extent creation worked or returned error,
512 * we don't need to create any more async work items.
513 * Unlock and free up our temp pages.
514 */
515 extent_clear_unlock_delalloc(inode, start, end, NULL,
516 clear_flags, PAGE_UNLOCK |
517 PAGE_CLEAR_DIRTY |
518 PAGE_SET_WRITEBACK |
519 PAGE_END_WRITEBACK);
520 goto free_pages_out;
521 }
522 }
523
524 if (will_compress) {
525 /*
526 * we aren't doing an inline extent round the compressed size
527 * up to a block size boundary so the allocator does sane
528 * things
529 */
530 total_compressed = ALIGN(total_compressed, blocksize);
531
532 /*
533 * one last check to make sure the compression is really a
534 * win, compare the page count read with the blocks on disk
535 */
536 total_in = ALIGN(total_in, PAGE_CACHE_SIZE);
537 if (total_compressed >= total_in) {
538 will_compress = 0;
539 } else {
540 num_bytes = total_in;
541 }
542 }
543 if (!will_compress && pages) {
544 /*
545 * the compression code ran but failed to make things smaller,
546 * free any pages it allocated and our page pointer array
547 */
548 for (i = 0; i < nr_pages_ret; i++) {
549 WARN_ON(pages[i]->mapping);
550 page_cache_release(pages[i]);
551 }
552 kfree(pages);
553 pages = NULL;
554 total_compressed = 0;
555 nr_pages_ret = 0;
556
557 /* flag the file so we don't compress in the future */
558 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
559 !(BTRFS_I(inode)->force_compress)) {
560 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
561 }
562 }
563 if (will_compress) {
564 *num_added += 1;
565
566 /* the async work queues will take care of doing actual
567 * allocation on disk for these compressed pages,
568 * and will submit them to the elevator.
569 */
570 add_async_extent(async_cow, start, num_bytes,
571 total_compressed, pages, nr_pages_ret,
572 compress_type);
573
574 if (start + num_bytes < end) {
575 start += num_bytes;
576 pages = NULL;
577 cond_resched();
578 goto again;
579 }
580 } else {
581 cleanup_and_bail_uncompressed:
582 /*
583 * No compression, but we still need to write the pages in
584 * the file we've been given so far. redirty the locked
585 * page if it corresponds to our extent and set things up
586 * for the async work queue to run cow_file_range to do
587 * the normal delalloc dance
588 */
589 if (page_offset(locked_page) >= start &&
590 page_offset(locked_page) <= end) {
591 __set_page_dirty_nobuffers(locked_page);
592 /* unlocked later on in the async handlers */
593 }
594 if (redirty)
595 extent_range_redirty_for_io(inode, start, end);
596 add_async_extent(async_cow, start, end - start + 1,
597 0, NULL, 0, BTRFS_COMPRESS_NONE);
598 *num_added += 1;
599 }
600
601 out:
602 return ret;
603
604 free_pages_out:
605 for (i = 0; i < nr_pages_ret; i++) {
606 WARN_ON(pages[i]->mapping);
607 page_cache_release(pages[i]);
608 }
609 kfree(pages);
610
611 goto out;
612 }
613
614 /*
615 * phase two of compressed writeback. This is the ordered portion
616 * of the code, which only gets called in the order the work was
617 * queued. We walk all the async extents created by compress_file_range
618 * and send them down to the disk.
619 */
620 static noinline int submit_compressed_extents(struct inode *inode,
621 struct async_cow *async_cow)
622 {
623 struct async_extent *async_extent;
624 u64 alloc_hint = 0;
625 struct btrfs_key ins;
626 struct extent_map *em;
627 struct btrfs_root *root = BTRFS_I(inode)->root;
628 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
629 struct extent_io_tree *io_tree;
630 int ret = 0;
631
632 if (list_empty(&async_cow->extents))
633 return 0;
634
635 again:
636 while (!list_empty(&async_cow->extents)) {
637 async_extent = list_entry(async_cow->extents.next,
638 struct async_extent, list);
639 list_del(&async_extent->list);
640
641 io_tree = &BTRFS_I(inode)->io_tree;
642
643 retry:
644 /* did the compression code fall back to uncompressed IO? */
645 if (!async_extent->pages) {
646 int page_started = 0;
647 unsigned long nr_written = 0;
648
649 lock_extent(io_tree, async_extent->start,
650 async_extent->start +
651 async_extent->ram_size - 1);
652
653 /* allocate blocks */
654 ret = cow_file_range(inode, async_cow->locked_page,
655 async_extent->start,
656 async_extent->start +
657 async_extent->ram_size - 1,
658 &page_started, &nr_written, 0);
659
660 /* JDM XXX */
661
662 /*
663 * if page_started, cow_file_range inserted an
664 * inline extent and took care of all the unlocking
665 * and IO for us. Otherwise, we need to submit
666 * all those pages down to the drive.
667 */
668 if (!page_started && !ret)
669 extent_write_locked_range(io_tree,
670 inode, async_extent->start,
671 async_extent->start +
672 async_extent->ram_size - 1,
673 btrfs_get_extent,
674 WB_SYNC_ALL);
675 else if (ret)
676 unlock_page(async_cow->locked_page);
677 kfree(async_extent);
678 cond_resched();
679 continue;
680 }
681
682 lock_extent(io_tree, async_extent->start,
683 async_extent->start + async_extent->ram_size - 1);
684
685 ret = btrfs_reserve_extent(root,
686 async_extent->compressed_size,
687 async_extent->compressed_size,
688 0, alloc_hint, &ins, 1);
689 if (ret) {
690 int i;
691
692 for (i = 0; i < async_extent->nr_pages; i++) {
693 WARN_ON(async_extent->pages[i]->mapping);
694 page_cache_release(async_extent->pages[i]);
695 }
696 kfree(async_extent->pages);
697 async_extent->nr_pages = 0;
698 async_extent->pages = NULL;
699
700 if (ret == -ENOSPC) {
701 unlock_extent(io_tree, async_extent->start,
702 async_extent->start +
703 async_extent->ram_size - 1);
704 goto retry;
705 }
706 goto out_free;
707 }
708
709 /*
710 * here we're doing allocation and writeback of the
711 * compressed pages
712 */
713 btrfs_drop_extent_cache(inode, async_extent->start,
714 async_extent->start +
715 async_extent->ram_size - 1, 0);
716
717 em = alloc_extent_map();
718 if (!em) {
719 ret = -ENOMEM;
720 goto out_free_reserve;
721 }
722 em->start = async_extent->start;
723 em->len = async_extent->ram_size;
724 em->orig_start = em->start;
725 em->mod_start = em->start;
726 em->mod_len = em->len;
727
728 em->block_start = ins.objectid;
729 em->block_len = ins.offset;
730 em->orig_block_len = ins.offset;
731 em->ram_bytes = async_extent->ram_size;
732 em->bdev = root->fs_info->fs_devices->latest_bdev;
733 em->compress_type = async_extent->compress_type;
734 set_bit(EXTENT_FLAG_PINNED, &em->flags);
735 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
736 em->generation = -1;
737
738 while (1) {
739 write_lock(&em_tree->lock);
740 ret = add_extent_mapping(em_tree, em, 1);
741 write_unlock(&em_tree->lock);
742 if (ret != -EEXIST) {
743 free_extent_map(em);
744 break;
745 }
746 btrfs_drop_extent_cache(inode, async_extent->start,
747 async_extent->start +
748 async_extent->ram_size - 1, 0);
749 }
750
751 if (ret)
752 goto out_free_reserve;
753
754 ret = btrfs_add_ordered_extent_compress(inode,
755 async_extent->start,
756 ins.objectid,
757 async_extent->ram_size,
758 ins.offset,
759 BTRFS_ORDERED_COMPRESSED,
760 async_extent->compress_type);
761 if (ret)
762 goto out_free_reserve;
763
764 /*
765 * clear dirty, set writeback and unlock the pages.
766 */
767 extent_clear_unlock_delalloc(inode, async_extent->start,
768 async_extent->start +
769 async_extent->ram_size - 1,
770 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
771 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
772 PAGE_SET_WRITEBACK);
773 ret = btrfs_submit_compressed_write(inode,
774 async_extent->start,
775 async_extent->ram_size,
776 ins.objectid,
777 ins.offset, async_extent->pages,
778 async_extent->nr_pages);
779 alloc_hint = ins.objectid + ins.offset;
780 kfree(async_extent);
781 if (ret)
782 goto out;
783 cond_resched();
784 }
785 ret = 0;
786 out:
787 return ret;
788 out_free_reserve:
789 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
790 out_free:
791 extent_clear_unlock_delalloc(inode, async_extent->start,
792 async_extent->start +
793 async_extent->ram_size - 1,
794 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
795 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
796 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
797 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
798 kfree(async_extent);
799 goto again;
800 }
801
802 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
803 u64 num_bytes)
804 {
805 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
806 struct extent_map *em;
807 u64 alloc_hint = 0;
808
809 read_lock(&em_tree->lock);
810 em = search_extent_mapping(em_tree, start, num_bytes);
811 if (em) {
812 /*
813 * if block start isn't an actual block number then find the
814 * first block in this inode and use that as a hint. If that
815 * block is also bogus then just don't worry about it.
816 */
817 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
818 free_extent_map(em);
819 em = search_extent_mapping(em_tree, 0, 0);
820 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
821 alloc_hint = em->block_start;
822 if (em)
823 free_extent_map(em);
824 } else {
825 alloc_hint = em->block_start;
826 free_extent_map(em);
827 }
828 }
829 read_unlock(&em_tree->lock);
830
831 return alloc_hint;
832 }
833
834 /*
835 * when extent_io.c finds a delayed allocation range in the file,
836 * the call backs end up in this code. The basic idea is to
837 * allocate extents on disk for the range, and create ordered data structs
838 * in ram to track those extents.
839 *
840 * locked_page is the page that writepage had locked already. We use
841 * it to make sure we don't do extra locks or unlocks.
842 *
843 * *page_started is set to one if we unlock locked_page and do everything
844 * required to start IO on it. It may be clean and already done with
845 * IO when we return.
846 */
847 static noinline int cow_file_range(struct inode *inode,
848 struct page *locked_page,
849 u64 start, u64 end, int *page_started,
850 unsigned long *nr_written,
851 int unlock)
852 {
853 struct btrfs_root *root = BTRFS_I(inode)->root;
854 u64 alloc_hint = 0;
855 u64 num_bytes;
856 unsigned long ram_size;
857 u64 disk_num_bytes;
858 u64 cur_alloc_size;
859 u64 blocksize = root->sectorsize;
860 struct btrfs_key ins;
861 struct extent_map *em;
862 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
863 int ret = 0;
864
865 if (btrfs_is_free_space_inode(inode)) {
866 WARN_ON_ONCE(1);
867 return -EINVAL;
868 }
869
870 num_bytes = ALIGN(end - start + 1, blocksize);
871 num_bytes = max(blocksize, num_bytes);
872 disk_num_bytes = num_bytes;
873
874 /* if this is a small write inside eof, kick off defrag */
875 if (num_bytes < 64 * 1024 &&
876 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
877 btrfs_add_inode_defrag(NULL, inode);
878
879 if (start == 0) {
880 /* lets try to make an inline extent */
881 ret = cow_file_range_inline(root, inode, start, end, 0, 0,
882 NULL);
883 if (ret == 0) {
884 extent_clear_unlock_delalloc(inode, start, end, NULL,
885 EXTENT_LOCKED | EXTENT_DELALLOC |
886 EXTENT_DEFRAG, PAGE_UNLOCK |
887 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
888 PAGE_END_WRITEBACK);
889
890 *nr_written = *nr_written +
891 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
892 *page_started = 1;
893 goto out;
894 } else if (ret < 0) {
895 goto out_unlock;
896 }
897 }
898
899 BUG_ON(disk_num_bytes >
900 btrfs_super_total_bytes(root->fs_info->super_copy));
901
902 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
903 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
904
905 while (disk_num_bytes > 0) {
906 unsigned long op;
907
908 cur_alloc_size = disk_num_bytes;
909 ret = btrfs_reserve_extent(root, cur_alloc_size,
910 root->sectorsize, 0, alloc_hint,
911 &ins, 1);
912 if (ret < 0)
913 goto out_unlock;
914
915 em = alloc_extent_map();
916 if (!em) {
917 ret = -ENOMEM;
918 goto out_reserve;
919 }
920 em->start = start;
921 em->orig_start = em->start;
922 ram_size = ins.offset;
923 em->len = ins.offset;
924 em->mod_start = em->start;
925 em->mod_len = em->len;
926
927 em->block_start = ins.objectid;
928 em->block_len = ins.offset;
929 em->orig_block_len = ins.offset;
930 em->ram_bytes = ram_size;
931 em->bdev = root->fs_info->fs_devices->latest_bdev;
932 set_bit(EXTENT_FLAG_PINNED, &em->flags);
933 em->generation = -1;
934
935 while (1) {
936 write_lock(&em_tree->lock);
937 ret = add_extent_mapping(em_tree, em, 1);
938 write_unlock(&em_tree->lock);
939 if (ret != -EEXIST) {
940 free_extent_map(em);
941 break;
942 }
943 btrfs_drop_extent_cache(inode, start,
944 start + ram_size - 1, 0);
945 }
946 if (ret)
947 goto out_reserve;
948
949 cur_alloc_size = ins.offset;
950 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
951 ram_size, cur_alloc_size, 0);
952 if (ret)
953 goto out_reserve;
954
955 if (root->root_key.objectid ==
956 BTRFS_DATA_RELOC_TREE_OBJECTID) {
957 ret = btrfs_reloc_clone_csums(inode, start,
958 cur_alloc_size);
959 if (ret)
960 goto out_reserve;
961 }
962
963 if (disk_num_bytes < cur_alloc_size)
964 break;
965
966 /* we're not doing compressed IO, don't unlock the first
967 * page (which the caller expects to stay locked), don't
968 * clear any dirty bits and don't set any writeback bits
969 *
970 * Do set the Private2 bit so we know this page was properly
971 * setup for writepage
972 */
973 op = unlock ? PAGE_UNLOCK : 0;
974 op |= PAGE_SET_PRIVATE2;
975
976 extent_clear_unlock_delalloc(inode, start,
977 start + ram_size - 1, locked_page,
978 EXTENT_LOCKED | EXTENT_DELALLOC,
979 op);
980 disk_num_bytes -= cur_alloc_size;
981 num_bytes -= cur_alloc_size;
982 alloc_hint = ins.objectid + ins.offset;
983 start += cur_alloc_size;
984 }
985 out:
986 return ret;
987
988 out_reserve:
989 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
990 out_unlock:
991 extent_clear_unlock_delalloc(inode, start, end, locked_page,
992 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
993 EXTENT_DELALLOC | EXTENT_DEFRAG,
994 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
995 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
996 goto out;
997 }
998
999 /*
1000 * work queue call back to started compression on a file and pages
1001 */
1002 static noinline void async_cow_start(struct btrfs_work *work)
1003 {
1004 struct async_cow *async_cow;
1005 int num_added = 0;
1006 async_cow = container_of(work, struct async_cow, work);
1007
1008 compress_file_range(async_cow->inode, async_cow->locked_page,
1009 async_cow->start, async_cow->end, async_cow,
1010 &num_added);
1011 if (num_added == 0) {
1012 btrfs_add_delayed_iput(async_cow->inode);
1013 async_cow->inode = NULL;
1014 }
1015 }
1016
1017 /*
1018 * work queue call back to submit previously compressed pages
1019 */
1020 static noinline void async_cow_submit(struct btrfs_work *work)
1021 {
1022 struct async_cow *async_cow;
1023 struct btrfs_root *root;
1024 unsigned long nr_pages;
1025
1026 async_cow = container_of(work, struct async_cow, work);
1027
1028 root = async_cow->root;
1029 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
1030 PAGE_CACHE_SHIFT;
1031
1032 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1033 5 * 1024 * 1024 &&
1034 waitqueue_active(&root->fs_info->async_submit_wait))
1035 wake_up(&root->fs_info->async_submit_wait);
1036
1037 if (async_cow->inode)
1038 submit_compressed_extents(async_cow->inode, async_cow);
1039 }
1040
1041 static noinline void async_cow_free(struct btrfs_work *work)
1042 {
1043 struct async_cow *async_cow;
1044 async_cow = container_of(work, struct async_cow, work);
1045 if (async_cow->inode)
1046 btrfs_add_delayed_iput(async_cow->inode);
1047 kfree(async_cow);
1048 }
1049
1050 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1051 u64 start, u64 end, int *page_started,
1052 unsigned long *nr_written)
1053 {
1054 struct async_cow *async_cow;
1055 struct btrfs_root *root = BTRFS_I(inode)->root;
1056 unsigned long nr_pages;
1057 u64 cur_end;
1058 int limit = 10 * 1024 * 1024;
1059
1060 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1061 1, 0, NULL, GFP_NOFS);
1062 while (start < end) {
1063 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1064 BUG_ON(!async_cow); /* -ENOMEM */
1065 async_cow->inode = igrab(inode);
1066 async_cow->root = root;
1067 async_cow->locked_page = locked_page;
1068 async_cow->start = start;
1069
1070 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
1071 cur_end = end;
1072 else
1073 cur_end = min(end, start + 512 * 1024 - 1);
1074
1075 async_cow->end = cur_end;
1076 INIT_LIST_HEAD(&async_cow->extents);
1077
1078 async_cow->work.func = async_cow_start;
1079 async_cow->work.ordered_func = async_cow_submit;
1080 async_cow->work.ordered_free = async_cow_free;
1081 async_cow->work.flags = 0;
1082
1083 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
1084 PAGE_CACHE_SHIFT;
1085 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1086
1087 btrfs_queue_worker(&root->fs_info->delalloc_workers,
1088 &async_cow->work);
1089
1090 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1091 wait_event(root->fs_info->async_submit_wait,
1092 (atomic_read(&root->fs_info->async_delalloc_pages) <
1093 limit));
1094 }
1095
1096 while (atomic_read(&root->fs_info->async_submit_draining) &&
1097 atomic_read(&root->fs_info->async_delalloc_pages)) {
1098 wait_event(root->fs_info->async_submit_wait,
1099 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1100 0));
1101 }
1102
1103 *nr_written += nr_pages;
1104 start = cur_end + 1;
1105 }
1106 *page_started = 1;
1107 return 0;
1108 }
1109
1110 static noinline int csum_exist_in_range(struct btrfs_root *root,
1111 u64 bytenr, u64 num_bytes)
1112 {
1113 int ret;
1114 struct btrfs_ordered_sum *sums;
1115 LIST_HEAD(list);
1116
1117 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1118 bytenr + num_bytes - 1, &list, 0);
1119 if (ret == 0 && list_empty(&list))
1120 return 0;
1121
1122 while (!list_empty(&list)) {
1123 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1124 list_del(&sums->list);
1125 kfree(sums);
1126 }
1127 return 1;
1128 }
1129
1130 /*
1131 * when nowcow writeback call back. This checks for snapshots or COW copies
1132 * of the extents that exist in the file, and COWs the file as required.
1133 *
1134 * If no cow copies or snapshots exist, we write directly to the existing
1135 * blocks on disk
1136 */
1137 static noinline int run_delalloc_nocow(struct inode *inode,
1138 struct page *locked_page,
1139 u64 start, u64 end, int *page_started, int force,
1140 unsigned long *nr_written)
1141 {
1142 struct btrfs_root *root = BTRFS_I(inode)->root;
1143 struct btrfs_trans_handle *trans;
1144 struct extent_buffer *leaf;
1145 struct btrfs_path *path;
1146 struct btrfs_file_extent_item *fi;
1147 struct btrfs_key found_key;
1148 u64 cow_start;
1149 u64 cur_offset;
1150 u64 extent_end;
1151 u64 extent_offset;
1152 u64 disk_bytenr;
1153 u64 num_bytes;
1154 u64 disk_num_bytes;
1155 u64 ram_bytes;
1156 int extent_type;
1157 int ret, err;
1158 int type;
1159 int nocow;
1160 int check_prev = 1;
1161 bool nolock;
1162 u64 ino = btrfs_ino(inode);
1163
1164 path = btrfs_alloc_path();
1165 if (!path) {
1166 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1167 EXTENT_LOCKED | EXTENT_DELALLOC |
1168 EXTENT_DO_ACCOUNTING |
1169 EXTENT_DEFRAG, PAGE_UNLOCK |
1170 PAGE_CLEAR_DIRTY |
1171 PAGE_SET_WRITEBACK |
1172 PAGE_END_WRITEBACK);
1173 return -ENOMEM;
1174 }
1175
1176 nolock = btrfs_is_free_space_inode(inode);
1177
1178 if (nolock)
1179 trans = btrfs_join_transaction_nolock(root);
1180 else
1181 trans = btrfs_join_transaction(root);
1182
1183 if (IS_ERR(trans)) {
1184 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1185 EXTENT_LOCKED | EXTENT_DELALLOC |
1186 EXTENT_DO_ACCOUNTING |
1187 EXTENT_DEFRAG, PAGE_UNLOCK |
1188 PAGE_CLEAR_DIRTY |
1189 PAGE_SET_WRITEBACK |
1190 PAGE_END_WRITEBACK);
1191 btrfs_free_path(path);
1192 return PTR_ERR(trans);
1193 }
1194
1195 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1196
1197 cow_start = (u64)-1;
1198 cur_offset = start;
1199 while (1) {
1200 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1201 cur_offset, 0);
1202 if (ret < 0)
1203 goto error;
1204 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1205 leaf = path->nodes[0];
1206 btrfs_item_key_to_cpu(leaf, &found_key,
1207 path->slots[0] - 1);
1208 if (found_key.objectid == ino &&
1209 found_key.type == BTRFS_EXTENT_DATA_KEY)
1210 path->slots[0]--;
1211 }
1212 check_prev = 0;
1213 next_slot:
1214 leaf = path->nodes[0];
1215 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1216 ret = btrfs_next_leaf(root, path);
1217 if (ret < 0)
1218 goto error;
1219 if (ret > 0)
1220 break;
1221 leaf = path->nodes[0];
1222 }
1223
1224 nocow = 0;
1225 disk_bytenr = 0;
1226 num_bytes = 0;
1227 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1228
1229 if (found_key.objectid > ino ||
1230 found_key.type > BTRFS_EXTENT_DATA_KEY ||
1231 found_key.offset > end)
1232 break;
1233
1234 if (found_key.offset > cur_offset) {
1235 extent_end = found_key.offset;
1236 extent_type = 0;
1237 goto out_check;
1238 }
1239
1240 fi = btrfs_item_ptr(leaf, path->slots[0],
1241 struct btrfs_file_extent_item);
1242 extent_type = btrfs_file_extent_type(leaf, fi);
1243
1244 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1245 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1246 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1247 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1248 extent_offset = btrfs_file_extent_offset(leaf, fi);
1249 extent_end = found_key.offset +
1250 btrfs_file_extent_num_bytes(leaf, fi);
1251 disk_num_bytes =
1252 btrfs_file_extent_disk_num_bytes(leaf, fi);
1253 if (extent_end <= start) {
1254 path->slots[0]++;
1255 goto next_slot;
1256 }
1257 if (disk_bytenr == 0)
1258 goto out_check;
1259 if (btrfs_file_extent_compression(leaf, fi) ||
1260 btrfs_file_extent_encryption(leaf, fi) ||
1261 btrfs_file_extent_other_encoding(leaf, fi))
1262 goto out_check;
1263 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1264 goto out_check;
1265 if (btrfs_extent_readonly(root, disk_bytenr))
1266 goto out_check;
1267 if (btrfs_cross_ref_exist(trans, root, ino,
1268 found_key.offset -
1269 extent_offset, disk_bytenr))
1270 goto out_check;
1271 disk_bytenr += extent_offset;
1272 disk_bytenr += cur_offset - found_key.offset;
1273 num_bytes = min(end + 1, extent_end) - cur_offset;
1274 /*
1275 * force cow if csum exists in the range.
1276 * this ensure that csum for a given extent are
1277 * either valid or do not exist.
1278 */
1279 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1280 goto out_check;
1281 nocow = 1;
1282 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1283 extent_end = found_key.offset +
1284 btrfs_file_extent_inline_len(leaf,
1285 path->slots[0], fi);
1286 extent_end = ALIGN(extent_end, root->sectorsize);
1287 } else {
1288 BUG_ON(1);
1289 }
1290 out_check:
1291 if (extent_end <= start) {
1292 path->slots[0]++;
1293 goto next_slot;
1294 }
1295 if (!nocow) {
1296 if (cow_start == (u64)-1)
1297 cow_start = cur_offset;
1298 cur_offset = extent_end;
1299 if (cur_offset > end)
1300 break;
1301 path->slots[0]++;
1302 goto next_slot;
1303 }
1304
1305 btrfs_release_path(path);
1306 if (cow_start != (u64)-1) {
1307 ret = cow_file_range(inode, locked_page,
1308 cow_start, found_key.offset - 1,
1309 page_started, nr_written, 1);
1310 if (ret)
1311 goto error;
1312 cow_start = (u64)-1;
1313 }
1314
1315 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1316 struct extent_map *em;
1317 struct extent_map_tree *em_tree;
1318 em_tree = &BTRFS_I(inode)->extent_tree;
1319 em = alloc_extent_map();
1320 BUG_ON(!em); /* -ENOMEM */
1321 em->start = cur_offset;
1322 em->orig_start = found_key.offset - extent_offset;
1323 em->len = num_bytes;
1324 em->block_len = num_bytes;
1325 em->block_start = disk_bytenr;
1326 em->orig_block_len = disk_num_bytes;
1327 em->ram_bytes = ram_bytes;
1328 em->bdev = root->fs_info->fs_devices->latest_bdev;
1329 em->mod_start = em->start;
1330 em->mod_len = em->len;
1331 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1332 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1333 em->generation = -1;
1334 while (1) {
1335 write_lock(&em_tree->lock);
1336 ret = add_extent_mapping(em_tree, em, 1);
1337 write_unlock(&em_tree->lock);
1338 if (ret != -EEXIST) {
1339 free_extent_map(em);
1340 break;
1341 }
1342 btrfs_drop_extent_cache(inode, em->start,
1343 em->start + em->len - 1, 0);
1344 }
1345 type = BTRFS_ORDERED_PREALLOC;
1346 } else {
1347 type = BTRFS_ORDERED_NOCOW;
1348 }
1349
1350 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1351 num_bytes, num_bytes, type);
1352 BUG_ON(ret); /* -ENOMEM */
1353
1354 if (root->root_key.objectid ==
1355 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1356 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1357 num_bytes);
1358 if (ret)
1359 goto error;
1360 }
1361
1362 extent_clear_unlock_delalloc(inode, cur_offset,
1363 cur_offset + num_bytes - 1,
1364 locked_page, EXTENT_LOCKED |
1365 EXTENT_DELALLOC, PAGE_UNLOCK |
1366 PAGE_SET_PRIVATE2);
1367 cur_offset = extent_end;
1368 if (cur_offset > end)
1369 break;
1370 }
1371 btrfs_release_path(path);
1372
1373 if (cur_offset <= end && cow_start == (u64)-1) {
1374 cow_start = cur_offset;
1375 cur_offset = end;
1376 }
1377
1378 if (cow_start != (u64)-1) {
1379 ret = cow_file_range(inode, locked_page, cow_start, end,
1380 page_started, nr_written, 1);
1381 if (ret)
1382 goto error;
1383 }
1384
1385 error:
1386 err = btrfs_end_transaction(trans, root);
1387 if (!ret)
1388 ret = err;
1389
1390 if (ret && cur_offset < end)
1391 extent_clear_unlock_delalloc(inode, cur_offset, end,
1392 locked_page, EXTENT_LOCKED |
1393 EXTENT_DELALLOC | EXTENT_DEFRAG |
1394 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1395 PAGE_CLEAR_DIRTY |
1396 PAGE_SET_WRITEBACK |
1397 PAGE_END_WRITEBACK);
1398 btrfs_free_path(path);
1399 return ret;
1400 }
1401
1402 /*
1403 * extent_io.c call back to do delayed allocation processing
1404 */
1405 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1406 u64 start, u64 end, int *page_started,
1407 unsigned long *nr_written)
1408 {
1409 int ret;
1410 struct btrfs_root *root = BTRFS_I(inode)->root;
1411
1412 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) {
1413 ret = run_delalloc_nocow(inode, locked_page, start, end,
1414 page_started, 1, nr_written);
1415 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC) {
1416 ret = run_delalloc_nocow(inode, locked_page, start, end,
1417 page_started, 0, nr_written);
1418 } else if (!btrfs_test_opt(root, COMPRESS) &&
1419 !(BTRFS_I(inode)->force_compress) &&
1420 !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS)) {
1421 ret = cow_file_range(inode, locked_page, start, end,
1422 page_started, nr_written, 1);
1423 } else {
1424 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1425 &BTRFS_I(inode)->runtime_flags);
1426 ret = cow_file_range_async(inode, locked_page, start, end,
1427 page_started, nr_written);
1428 }
1429 return ret;
1430 }
1431
1432 static void btrfs_split_extent_hook(struct inode *inode,
1433 struct extent_state *orig, u64 split)
1434 {
1435 /* not delalloc, ignore it */
1436 if (!(orig->state & EXTENT_DELALLOC))
1437 return;
1438
1439 spin_lock(&BTRFS_I(inode)->lock);
1440 BTRFS_I(inode)->outstanding_extents++;
1441 spin_unlock(&BTRFS_I(inode)->lock);
1442 }
1443
1444 /*
1445 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1446 * extents so we can keep track of new extents that are just merged onto old
1447 * extents, such as when we are doing sequential writes, so we can properly
1448 * account for the metadata space we'll need.
1449 */
1450 static void btrfs_merge_extent_hook(struct inode *inode,
1451 struct extent_state *new,
1452 struct extent_state *other)
1453 {
1454 /* not delalloc, ignore it */
1455 if (!(other->state & EXTENT_DELALLOC))
1456 return;
1457
1458 spin_lock(&BTRFS_I(inode)->lock);
1459 BTRFS_I(inode)->outstanding_extents--;
1460 spin_unlock(&BTRFS_I(inode)->lock);
1461 }
1462
1463 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1464 struct inode *inode)
1465 {
1466 spin_lock(&root->delalloc_lock);
1467 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1468 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1469 &root->delalloc_inodes);
1470 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1471 &BTRFS_I(inode)->runtime_flags);
1472 root->nr_delalloc_inodes++;
1473 if (root->nr_delalloc_inodes == 1) {
1474 spin_lock(&root->fs_info->delalloc_root_lock);
1475 BUG_ON(!list_empty(&root->delalloc_root));
1476 list_add_tail(&root->delalloc_root,
1477 &root->fs_info->delalloc_roots);
1478 spin_unlock(&root->fs_info->delalloc_root_lock);
1479 }
1480 }
1481 spin_unlock(&root->delalloc_lock);
1482 }
1483
1484 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1485 struct inode *inode)
1486 {
1487 spin_lock(&root->delalloc_lock);
1488 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1489 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1490 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1491 &BTRFS_I(inode)->runtime_flags);
1492 root->nr_delalloc_inodes--;
1493 if (!root->nr_delalloc_inodes) {
1494 spin_lock(&root->fs_info->delalloc_root_lock);
1495 BUG_ON(list_empty(&root->delalloc_root));
1496 list_del_init(&root->delalloc_root);
1497 spin_unlock(&root->fs_info->delalloc_root_lock);
1498 }
1499 }
1500 spin_unlock(&root->delalloc_lock);
1501 }
1502
1503 /*
1504 * extent_io.c set_bit_hook, used to track delayed allocation
1505 * bytes in this file, and to maintain the list of inodes that
1506 * have pending delalloc work to be done.
1507 */
1508 static void btrfs_set_bit_hook(struct inode *inode,
1509 struct extent_state *state, unsigned long *bits)
1510 {
1511
1512 /*
1513 * set_bit and clear bit hooks normally require _irqsave/restore
1514 * but in this case, we are only testing for the DELALLOC
1515 * bit, which is only set or cleared with irqs on
1516 */
1517 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1518 struct btrfs_root *root = BTRFS_I(inode)->root;
1519 u64 len = state->end + 1 - state->start;
1520 bool do_list = !btrfs_is_free_space_inode(inode);
1521
1522 if (*bits & EXTENT_FIRST_DELALLOC) {
1523 *bits &= ~EXTENT_FIRST_DELALLOC;
1524 } else {
1525 spin_lock(&BTRFS_I(inode)->lock);
1526 BTRFS_I(inode)->outstanding_extents++;
1527 spin_unlock(&BTRFS_I(inode)->lock);
1528 }
1529
1530 __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
1531 root->fs_info->delalloc_batch);
1532 spin_lock(&BTRFS_I(inode)->lock);
1533 BTRFS_I(inode)->delalloc_bytes += len;
1534 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1535 &BTRFS_I(inode)->runtime_flags))
1536 btrfs_add_delalloc_inodes(root, inode);
1537 spin_unlock(&BTRFS_I(inode)->lock);
1538 }
1539 }
1540
1541 /*
1542 * extent_io.c clear_bit_hook, see set_bit_hook for why
1543 */
1544 static void btrfs_clear_bit_hook(struct inode *inode,
1545 struct extent_state *state,
1546 unsigned long *bits)
1547 {
1548 /*
1549 * set_bit and clear bit hooks normally require _irqsave/restore
1550 * but in this case, we are only testing for the DELALLOC
1551 * bit, which is only set or cleared with irqs on
1552 */
1553 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1554 struct btrfs_root *root = BTRFS_I(inode)->root;
1555 u64 len = state->end + 1 - state->start;
1556 bool do_list = !btrfs_is_free_space_inode(inode);
1557
1558 if (*bits & EXTENT_FIRST_DELALLOC) {
1559 *bits &= ~EXTENT_FIRST_DELALLOC;
1560 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1561 spin_lock(&BTRFS_I(inode)->lock);
1562 BTRFS_I(inode)->outstanding_extents--;
1563 spin_unlock(&BTRFS_I(inode)->lock);
1564 }
1565
1566 /*
1567 * We don't reserve metadata space for space cache inodes so we
1568 * don't need to call dellalloc_release_metadata if there is an
1569 * error.
1570 */
1571 if (*bits & EXTENT_DO_ACCOUNTING &&
1572 root != root->fs_info->tree_root)
1573 btrfs_delalloc_release_metadata(inode, len);
1574
1575 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1576 && do_list && !(state->state & EXTENT_NORESERVE))
1577 btrfs_free_reserved_data_space(inode, len);
1578
1579 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
1580 root->fs_info->delalloc_batch);
1581 spin_lock(&BTRFS_I(inode)->lock);
1582 BTRFS_I(inode)->delalloc_bytes -= len;
1583 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1584 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1585 &BTRFS_I(inode)->runtime_flags))
1586 btrfs_del_delalloc_inode(root, inode);
1587 spin_unlock(&BTRFS_I(inode)->lock);
1588 }
1589 }
1590
1591 /*
1592 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1593 * we don't create bios that span stripes or chunks
1594 */
1595 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
1596 size_t size, struct bio *bio,
1597 unsigned long bio_flags)
1598 {
1599 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1600 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1601 u64 length = 0;
1602 u64 map_length;
1603 int ret;
1604
1605 if (bio_flags & EXTENT_BIO_COMPRESSED)
1606 return 0;
1607
1608 length = bio->bi_iter.bi_size;
1609 map_length = length;
1610 ret = btrfs_map_block(root->fs_info, rw, logical,
1611 &map_length, NULL, 0);
1612 /* Will always return 0 with map_multi == NULL */
1613 BUG_ON(ret < 0);
1614 if (map_length < length + size)
1615 return 1;
1616 return 0;
1617 }
1618
1619 /*
1620 * in order to insert checksums into the metadata in large chunks,
1621 * we wait until bio submission time. All the pages in the bio are
1622 * checksummed and sums are attached onto the ordered extent record.
1623 *
1624 * At IO completion time the cums attached on the ordered extent record
1625 * are inserted into the btree
1626 */
1627 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1628 struct bio *bio, int mirror_num,
1629 unsigned long bio_flags,
1630 u64 bio_offset)
1631 {
1632 struct btrfs_root *root = BTRFS_I(inode)->root;
1633 int ret = 0;
1634
1635 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1636 BUG_ON(ret); /* -ENOMEM */
1637 return 0;
1638 }
1639
1640 /*
1641 * in order to insert checksums into the metadata in large chunks,
1642 * we wait until bio submission time. All the pages in the bio are
1643 * checksummed and sums are attached onto the ordered extent record.
1644 *
1645 * At IO completion time the cums attached on the ordered extent record
1646 * are inserted into the btree
1647 */
1648 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1649 int mirror_num, unsigned long bio_flags,
1650 u64 bio_offset)
1651 {
1652 struct btrfs_root *root = BTRFS_I(inode)->root;
1653 int ret;
1654
1655 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
1656 if (ret)
1657 bio_endio(bio, ret);
1658 return ret;
1659 }
1660
1661 /*
1662 * extent_io.c submission hook. This does the right thing for csum calculation
1663 * on write, or reading the csums from the tree before a read
1664 */
1665 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1666 int mirror_num, unsigned long bio_flags,
1667 u64 bio_offset)
1668 {
1669 struct btrfs_root *root = BTRFS_I(inode)->root;
1670 int ret = 0;
1671 int skip_sum;
1672 int metadata = 0;
1673 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1674
1675 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1676
1677 if (btrfs_is_free_space_inode(inode))
1678 metadata = 2;
1679
1680 if (!(rw & REQ_WRITE)) {
1681 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1682 if (ret)
1683 goto out;
1684
1685 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1686 ret = btrfs_submit_compressed_read(inode, bio,
1687 mirror_num,
1688 bio_flags);
1689 goto out;
1690 } else if (!skip_sum) {
1691 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1692 if (ret)
1693 goto out;
1694 }
1695 goto mapit;
1696 } else if (async && !skip_sum) {
1697 /* csum items have already been cloned */
1698 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1699 goto mapit;
1700 /* we're doing a write, do the async checksumming */
1701 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1702 inode, rw, bio, mirror_num,
1703 bio_flags, bio_offset,
1704 __btrfs_submit_bio_start,
1705 __btrfs_submit_bio_done);
1706 goto out;
1707 } else if (!skip_sum) {
1708 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1709 if (ret)
1710 goto out;
1711 }
1712
1713 mapit:
1714 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
1715
1716 out:
1717 if (ret < 0)
1718 bio_endio(bio, ret);
1719 return ret;
1720 }
1721
1722 /*
1723 * given a list of ordered sums record them in the inode. This happens
1724 * at IO completion time based on sums calculated at bio submission time.
1725 */
1726 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1727 struct inode *inode, u64 file_offset,
1728 struct list_head *list)
1729 {
1730 struct btrfs_ordered_sum *sum;
1731
1732 list_for_each_entry(sum, list, list) {
1733 trans->adding_csums = 1;
1734 btrfs_csum_file_blocks(trans,
1735 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1736 trans->adding_csums = 0;
1737 }
1738 return 0;
1739 }
1740
1741 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1742 struct extent_state **cached_state)
1743 {
1744 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0);
1745 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1746 cached_state, GFP_NOFS);
1747 }
1748
1749 /* see btrfs_writepage_start_hook for details on why this is required */
1750 struct btrfs_writepage_fixup {
1751 struct page *page;
1752 struct btrfs_work work;
1753 };
1754
1755 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1756 {
1757 struct btrfs_writepage_fixup *fixup;
1758 struct btrfs_ordered_extent *ordered;
1759 struct extent_state *cached_state = NULL;
1760 struct page *page;
1761 struct inode *inode;
1762 u64 page_start;
1763 u64 page_end;
1764 int ret;
1765
1766 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1767 page = fixup->page;
1768 again:
1769 lock_page(page);
1770 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1771 ClearPageChecked(page);
1772 goto out_page;
1773 }
1774
1775 inode = page->mapping->host;
1776 page_start = page_offset(page);
1777 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1778
1779 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
1780 &cached_state);
1781
1782 /* already ordered? We're done */
1783 if (PagePrivate2(page))
1784 goto out;
1785
1786 ordered = btrfs_lookup_ordered_extent(inode, page_start);
1787 if (ordered) {
1788 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
1789 page_end, &cached_state, GFP_NOFS);
1790 unlock_page(page);
1791 btrfs_start_ordered_extent(inode, ordered, 1);
1792 btrfs_put_ordered_extent(ordered);
1793 goto again;
1794 }
1795
1796 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
1797 if (ret) {
1798 mapping_set_error(page->mapping, ret);
1799 end_extent_writepage(page, ret, page_start, page_end);
1800 ClearPageChecked(page);
1801 goto out;
1802 }
1803
1804 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
1805 ClearPageChecked(page);
1806 set_page_dirty(page);
1807 out:
1808 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
1809 &cached_state, GFP_NOFS);
1810 out_page:
1811 unlock_page(page);
1812 page_cache_release(page);
1813 kfree(fixup);
1814 }
1815
1816 /*
1817 * There are a few paths in the higher layers of the kernel that directly
1818 * set the page dirty bit without asking the filesystem if it is a
1819 * good idea. This causes problems because we want to make sure COW
1820 * properly happens and the data=ordered rules are followed.
1821 *
1822 * In our case any range that doesn't have the ORDERED bit set
1823 * hasn't been properly setup for IO. We kick off an async process
1824 * to fix it up. The async helper will wait for ordered extents, set
1825 * the delalloc bit and make it safe to write the page.
1826 */
1827 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
1828 {
1829 struct inode *inode = page->mapping->host;
1830 struct btrfs_writepage_fixup *fixup;
1831 struct btrfs_root *root = BTRFS_I(inode)->root;
1832
1833 /* this page is properly in the ordered list */
1834 if (TestClearPagePrivate2(page))
1835 return 0;
1836
1837 if (PageChecked(page))
1838 return -EAGAIN;
1839
1840 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
1841 if (!fixup)
1842 return -EAGAIN;
1843
1844 SetPageChecked(page);
1845 page_cache_get(page);
1846 fixup->work.func = btrfs_writepage_fixup_worker;
1847 fixup->page = page;
1848 btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
1849 return -EBUSY;
1850 }
1851
1852 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
1853 struct inode *inode, u64 file_pos,
1854 u64 disk_bytenr, u64 disk_num_bytes,
1855 u64 num_bytes, u64 ram_bytes,
1856 u8 compression, u8 encryption,
1857 u16 other_encoding, int extent_type)
1858 {
1859 struct btrfs_root *root = BTRFS_I(inode)->root;
1860 struct btrfs_file_extent_item *fi;
1861 struct btrfs_path *path;
1862 struct extent_buffer *leaf;
1863 struct btrfs_key ins;
1864 int extent_inserted = 0;
1865 int ret;
1866
1867 path = btrfs_alloc_path();
1868 if (!path)
1869 return -ENOMEM;
1870
1871 /*
1872 * we may be replacing one extent in the tree with another.
1873 * The new extent is pinned in the extent map, and we don't want
1874 * to drop it from the cache until it is completely in the btree.
1875 *
1876 * So, tell btrfs_drop_extents to leave this extent in the cache.
1877 * the caller is expected to unpin it and allow it to be merged
1878 * with the others.
1879 */
1880 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
1881 file_pos + num_bytes, NULL, 0,
1882 1, sizeof(*fi), &extent_inserted);
1883 if (ret)
1884 goto out;
1885
1886 if (!extent_inserted) {
1887 ins.objectid = btrfs_ino(inode);
1888 ins.offset = file_pos;
1889 ins.type = BTRFS_EXTENT_DATA_KEY;
1890
1891 path->leave_spinning = 1;
1892 ret = btrfs_insert_empty_item(trans, root, path, &ins,
1893 sizeof(*fi));
1894 if (ret)
1895 goto out;
1896 }
1897 leaf = path->nodes[0];
1898 fi = btrfs_item_ptr(leaf, path->slots[0],
1899 struct btrfs_file_extent_item);
1900 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1901 btrfs_set_file_extent_type(leaf, fi, extent_type);
1902 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
1903 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
1904 btrfs_set_file_extent_offset(leaf, fi, 0);
1905 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
1906 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
1907 btrfs_set_file_extent_compression(leaf, fi, compression);
1908 btrfs_set_file_extent_encryption(leaf, fi, encryption);
1909 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
1910
1911 btrfs_mark_buffer_dirty(leaf);
1912 btrfs_release_path(path);
1913
1914 inode_add_bytes(inode, num_bytes);
1915
1916 ins.objectid = disk_bytenr;
1917 ins.offset = disk_num_bytes;
1918 ins.type = BTRFS_EXTENT_ITEM_KEY;
1919 ret = btrfs_alloc_reserved_file_extent(trans, root,
1920 root->root_key.objectid,
1921 btrfs_ino(inode), file_pos, &ins);
1922 out:
1923 btrfs_free_path(path);
1924
1925 return ret;
1926 }
1927
1928 /* snapshot-aware defrag */
1929 struct sa_defrag_extent_backref {
1930 struct rb_node node;
1931 struct old_sa_defrag_extent *old;
1932 u64 root_id;
1933 u64 inum;
1934 u64 file_pos;
1935 u64 extent_offset;
1936 u64 num_bytes;
1937 u64 generation;
1938 };
1939
1940 struct old_sa_defrag_extent {
1941 struct list_head list;
1942 struct new_sa_defrag_extent *new;
1943
1944 u64 extent_offset;
1945 u64 bytenr;
1946 u64 offset;
1947 u64 len;
1948 int count;
1949 };
1950
1951 struct new_sa_defrag_extent {
1952 struct rb_root root;
1953 struct list_head head;
1954 struct btrfs_path *path;
1955 struct inode *inode;
1956 u64 file_pos;
1957 u64 len;
1958 u64 bytenr;
1959 u64 disk_len;
1960 u8 compress_type;
1961 };
1962
1963 static int backref_comp(struct sa_defrag_extent_backref *b1,
1964 struct sa_defrag_extent_backref *b2)
1965 {
1966 if (b1->root_id < b2->root_id)
1967 return -1;
1968 else if (b1->root_id > b2->root_id)
1969 return 1;
1970
1971 if (b1->inum < b2->inum)
1972 return -1;
1973 else if (b1->inum > b2->inum)
1974 return 1;
1975
1976 if (b1->file_pos < b2->file_pos)
1977 return -1;
1978 else if (b1->file_pos > b2->file_pos)
1979 return 1;
1980
1981 /*
1982 * [------------------------------] ===> (a range of space)
1983 * |<--->| |<---->| =============> (fs/file tree A)
1984 * |<---------------------------->| ===> (fs/file tree B)
1985 *
1986 * A range of space can refer to two file extents in one tree while
1987 * refer to only one file extent in another tree.
1988 *
1989 * So we may process a disk offset more than one time(two extents in A)
1990 * and locate at the same extent(one extent in B), then insert two same
1991 * backrefs(both refer to the extent in B).
1992 */
1993 return 0;
1994 }
1995
1996 static void backref_insert(struct rb_root *root,
1997 struct sa_defrag_extent_backref *backref)
1998 {
1999 struct rb_node **p = &root->rb_node;
2000 struct rb_node *parent = NULL;
2001 struct sa_defrag_extent_backref *entry;
2002 int ret;
2003
2004 while (*p) {
2005 parent = *p;
2006 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2007
2008 ret = backref_comp(backref, entry);
2009 if (ret < 0)
2010 p = &(*p)->rb_left;
2011 else
2012 p = &(*p)->rb_right;
2013 }
2014
2015 rb_link_node(&backref->node, parent, p);
2016 rb_insert_color(&backref->node, root);
2017 }
2018
2019 /*
2020 * Note the backref might has changed, and in this case we just return 0.
2021 */
2022 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2023 void *ctx)
2024 {
2025 struct btrfs_file_extent_item *extent;
2026 struct btrfs_fs_info *fs_info;
2027 struct old_sa_defrag_extent *old = ctx;
2028 struct new_sa_defrag_extent *new = old->new;
2029 struct btrfs_path *path = new->path;
2030 struct btrfs_key key;
2031 struct btrfs_root *root;
2032 struct sa_defrag_extent_backref *backref;
2033 struct extent_buffer *leaf;
2034 struct inode *inode = new->inode;
2035 int slot;
2036 int ret;
2037 u64 extent_offset;
2038 u64 num_bytes;
2039
2040 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2041 inum == btrfs_ino(inode))
2042 return 0;
2043
2044 key.objectid = root_id;
2045 key.type = BTRFS_ROOT_ITEM_KEY;
2046 key.offset = (u64)-1;
2047
2048 fs_info = BTRFS_I(inode)->root->fs_info;
2049 root = btrfs_read_fs_root_no_name(fs_info, &key);
2050 if (IS_ERR(root)) {
2051 if (PTR_ERR(root) == -ENOENT)
2052 return 0;
2053 WARN_ON(1);
2054 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
2055 inum, offset, root_id);
2056 return PTR_ERR(root);
2057 }
2058
2059 key.objectid = inum;
2060 key.type = BTRFS_EXTENT_DATA_KEY;
2061 if (offset > (u64)-1 << 32)
2062 key.offset = 0;
2063 else
2064 key.offset = offset;
2065
2066 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2067 if (WARN_ON(ret < 0))
2068 return ret;
2069 ret = 0;
2070
2071 while (1) {
2072 cond_resched();
2073
2074 leaf = path->nodes[0];
2075 slot = path->slots[0];
2076
2077 if (slot >= btrfs_header_nritems(leaf)) {
2078 ret = btrfs_next_leaf(root, path);
2079 if (ret < 0) {
2080 goto out;
2081 } else if (ret > 0) {
2082 ret = 0;
2083 goto out;
2084 }
2085 continue;
2086 }
2087
2088 path->slots[0]++;
2089
2090 btrfs_item_key_to_cpu(leaf, &key, slot);
2091
2092 if (key.objectid > inum)
2093 goto out;
2094
2095 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2096 continue;
2097
2098 extent = btrfs_item_ptr(leaf, slot,
2099 struct btrfs_file_extent_item);
2100
2101 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2102 continue;
2103
2104 /*
2105 * 'offset' refers to the exact key.offset,
2106 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2107 * (key.offset - extent_offset).
2108 */
2109 if (key.offset != offset)
2110 continue;
2111
2112 extent_offset = btrfs_file_extent_offset(leaf, extent);
2113 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2114
2115 if (extent_offset >= old->extent_offset + old->offset +
2116 old->len || extent_offset + num_bytes <=
2117 old->extent_offset + old->offset)
2118 continue;
2119 break;
2120 }
2121
2122 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2123 if (!backref) {
2124 ret = -ENOENT;
2125 goto out;
2126 }
2127
2128 backref->root_id = root_id;
2129 backref->inum = inum;
2130 backref->file_pos = offset;
2131 backref->num_bytes = num_bytes;
2132 backref->extent_offset = extent_offset;
2133 backref->generation = btrfs_file_extent_generation(leaf, extent);
2134 backref->old = old;
2135 backref_insert(&new->root, backref);
2136 old->count++;
2137 out:
2138 btrfs_release_path(path);
2139 WARN_ON(ret);
2140 return ret;
2141 }
2142
2143 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2144 struct new_sa_defrag_extent *new)
2145 {
2146 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
2147 struct old_sa_defrag_extent *old, *tmp;
2148 int ret;
2149
2150 new->path = path;
2151
2152 list_for_each_entry_safe(old, tmp, &new->head, list) {
2153 ret = iterate_inodes_from_logical(old->bytenr +
2154 old->extent_offset, fs_info,
2155 path, record_one_backref,
2156 old);
2157 if (ret < 0 && ret != -ENOENT)
2158 return false;
2159
2160 /* no backref to be processed for this extent */
2161 if (!old->count) {
2162 list_del(&old->list);
2163 kfree(old);
2164 }
2165 }
2166
2167 if (list_empty(&new->head))
2168 return false;
2169
2170 return true;
2171 }
2172
2173 static int relink_is_mergable(struct extent_buffer *leaf,
2174 struct btrfs_file_extent_item *fi,
2175 struct new_sa_defrag_extent *new)
2176 {
2177 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2178 return 0;
2179
2180 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2181 return 0;
2182
2183 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2184 return 0;
2185
2186 if (btrfs_file_extent_encryption(leaf, fi) ||
2187 btrfs_file_extent_other_encoding(leaf, fi))
2188 return 0;
2189
2190 return 1;
2191 }
2192
2193 /*
2194 * Note the backref might has changed, and in this case we just return 0.
2195 */
2196 static noinline int relink_extent_backref(struct btrfs_path *path,
2197 struct sa_defrag_extent_backref *prev,
2198 struct sa_defrag_extent_backref *backref)
2199 {
2200 struct btrfs_file_extent_item *extent;
2201 struct btrfs_file_extent_item *item;
2202 struct btrfs_ordered_extent *ordered;
2203 struct btrfs_trans_handle *trans;
2204 struct btrfs_fs_info *fs_info;
2205 struct btrfs_root *root;
2206 struct btrfs_key key;
2207 struct extent_buffer *leaf;
2208 struct old_sa_defrag_extent *old = backref->old;
2209 struct new_sa_defrag_extent *new = old->new;
2210 struct inode *src_inode = new->inode;
2211 struct inode *inode;
2212 struct extent_state *cached = NULL;
2213 int ret = 0;
2214 u64 start;
2215 u64 len;
2216 u64 lock_start;
2217 u64 lock_end;
2218 bool merge = false;
2219 int index;
2220
2221 if (prev && prev->root_id == backref->root_id &&
2222 prev->inum == backref->inum &&
2223 prev->file_pos + prev->num_bytes == backref->file_pos)
2224 merge = true;
2225
2226 /* step 1: get root */
2227 key.objectid = backref->root_id;
2228 key.type = BTRFS_ROOT_ITEM_KEY;
2229 key.offset = (u64)-1;
2230
2231 fs_info = BTRFS_I(src_inode)->root->fs_info;
2232 index = srcu_read_lock(&fs_info->subvol_srcu);
2233
2234 root = btrfs_read_fs_root_no_name(fs_info, &key);
2235 if (IS_ERR(root)) {
2236 srcu_read_unlock(&fs_info->subvol_srcu, index);
2237 if (PTR_ERR(root) == -ENOENT)
2238 return 0;
2239 return PTR_ERR(root);
2240 }
2241
2242 /* step 2: get inode */
2243 key.objectid = backref->inum;
2244 key.type = BTRFS_INODE_ITEM_KEY;
2245 key.offset = 0;
2246
2247 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2248 if (IS_ERR(inode)) {
2249 srcu_read_unlock(&fs_info->subvol_srcu, index);
2250 return 0;
2251 }
2252
2253 srcu_read_unlock(&fs_info->subvol_srcu, index);
2254
2255 /* step 3: relink backref */
2256 lock_start = backref->file_pos;
2257 lock_end = backref->file_pos + backref->num_bytes - 1;
2258 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2259 0, &cached);
2260
2261 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2262 if (ordered) {
2263 btrfs_put_ordered_extent(ordered);
2264 goto out_unlock;
2265 }
2266
2267 trans = btrfs_join_transaction(root);
2268 if (IS_ERR(trans)) {
2269 ret = PTR_ERR(trans);
2270 goto out_unlock;
2271 }
2272
2273 key.objectid = backref->inum;
2274 key.type = BTRFS_EXTENT_DATA_KEY;
2275 key.offset = backref->file_pos;
2276
2277 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2278 if (ret < 0) {
2279 goto out_free_path;
2280 } else if (ret > 0) {
2281 ret = 0;
2282 goto out_free_path;
2283 }
2284
2285 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2286 struct btrfs_file_extent_item);
2287
2288 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2289 backref->generation)
2290 goto out_free_path;
2291
2292 btrfs_release_path(path);
2293
2294 start = backref->file_pos;
2295 if (backref->extent_offset < old->extent_offset + old->offset)
2296 start += old->extent_offset + old->offset -
2297 backref->extent_offset;
2298
2299 len = min(backref->extent_offset + backref->num_bytes,
2300 old->extent_offset + old->offset + old->len);
2301 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2302
2303 ret = btrfs_drop_extents(trans, root, inode, start,
2304 start + len, 1);
2305 if (ret)
2306 goto out_free_path;
2307 again:
2308 key.objectid = btrfs_ino(inode);
2309 key.type = BTRFS_EXTENT_DATA_KEY;
2310 key.offset = start;
2311
2312 path->leave_spinning = 1;
2313 if (merge) {
2314 struct btrfs_file_extent_item *fi;
2315 u64 extent_len;
2316 struct btrfs_key found_key;
2317
2318 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2319 if (ret < 0)
2320 goto out_free_path;
2321
2322 path->slots[0]--;
2323 leaf = path->nodes[0];
2324 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2325
2326 fi = btrfs_item_ptr(leaf, path->slots[0],
2327 struct btrfs_file_extent_item);
2328 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2329
2330 if (extent_len + found_key.offset == start &&
2331 relink_is_mergable(leaf, fi, new)) {
2332 btrfs_set_file_extent_num_bytes(leaf, fi,
2333 extent_len + len);
2334 btrfs_mark_buffer_dirty(leaf);
2335 inode_add_bytes(inode, len);
2336
2337 ret = 1;
2338 goto out_free_path;
2339 } else {
2340 merge = false;
2341 btrfs_release_path(path);
2342 goto again;
2343 }
2344 }
2345
2346 ret = btrfs_insert_empty_item(trans, root, path, &key,
2347 sizeof(*extent));
2348 if (ret) {
2349 btrfs_abort_transaction(trans, root, ret);
2350 goto out_free_path;
2351 }
2352
2353 leaf = path->nodes[0];
2354 item = btrfs_item_ptr(leaf, path->slots[0],
2355 struct btrfs_file_extent_item);
2356 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2357 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2358 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2359 btrfs_set_file_extent_num_bytes(leaf, item, len);
2360 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2361 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2362 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2363 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2364 btrfs_set_file_extent_encryption(leaf, item, 0);
2365 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2366
2367 btrfs_mark_buffer_dirty(leaf);
2368 inode_add_bytes(inode, len);
2369 btrfs_release_path(path);
2370
2371 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2372 new->disk_len, 0,
2373 backref->root_id, backref->inum,
2374 new->file_pos, 0); /* start - extent_offset */
2375 if (ret) {
2376 btrfs_abort_transaction(trans, root, ret);
2377 goto out_free_path;
2378 }
2379
2380 ret = 1;
2381 out_free_path:
2382 btrfs_release_path(path);
2383 path->leave_spinning = 0;
2384 btrfs_end_transaction(trans, root);
2385 out_unlock:
2386 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2387 &cached, GFP_NOFS);
2388 iput(inode);
2389 return ret;
2390 }
2391
2392 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2393 {
2394 struct old_sa_defrag_extent *old, *tmp;
2395
2396 if (!new)
2397 return;
2398
2399 list_for_each_entry_safe(old, tmp, &new->head, list) {
2400 list_del(&old->list);
2401 kfree(old);
2402 }
2403 kfree(new);
2404 }
2405
2406 static void relink_file_extents(struct new_sa_defrag_extent *new)
2407 {
2408 struct btrfs_path *path;
2409 struct sa_defrag_extent_backref *backref;
2410 struct sa_defrag_extent_backref *prev = NULL;
2411 struct inode *inode;
2412 struct btrfs_root *root;
2413 struct rb_node *node;
2414 int ret;
2415
2416 inode = new->inode;
2417 root = BTRFS_I(inode)->root;
2418
2419 path = btrfs_alloc_path();
2420 if (!path)
2421 return;
2422
2423 if (!record_extent_backrefs(path, new)) {
2424 btrfs_free_path(path);
2425 goto out;
2426 }
2427 btrfs_release_path(path);
2428
2429 while (1) {
2430 node = rb_first(&new->root);
2431 if (!node)
2432 break;
2433 rb_erase(node, &new->root);
2434
2435 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2436
2437 ret = relink_extent_backref(path, prev, backref);
2438 WARN_ON(ret < 0);
2439
2440 kfree(prev);
2441
2442 if (ret == 1)
2443 prev = backref;
2444 else
2445 prev = NULL;
2446 cond_resched();
2447 }
2448 kfree(prev);
2449
2450 btrfs_free_path(path);
2451 out:
2452 free_sa_defrag_extent(new);
2453
2454 atomic_dec(&root->fs_info->defrag_running);
2455 wake_up(&root->fs_info->transaction_wait);
2456 }
2457
2458 static struct new_sa_defrag_extent *
2459 record_old_file_extents(struct inode *inode,
2460 struct btrfs_ordered_extent *ordered)
2461 {
2462 struct btrfs_root *root = BTRFS_I(inode)->root;
2463 struct btrfs_path *path;
2464 struct btrfs_key key;
2465 struct old_sa_defrag_extent *old;
2466 struct new_sa_defrag_extent *new;
2467 int ret;
2468
2469 new = kmalloc(sizeof(*new), GFP_NOFS);
2470 if (!new)
2471 return NULL;
2472
2473 new->inode = inode;
2474 new->file_pos = ordered->file_offset;
2475 new->len = ordered->len;
2476 new->bytenr = ordered->start;
2477 new->disk_len = ordered->disk_len;
2478 new->compress_type = ordered->compress_type;
2479 new->root = RB_ROOT;
2480 INIT_LIST_HEAD(&new->head);
2481
2482 path = btrfs_alloc_path();
2483 if (!path)
2484 goto out_kfree;
2485
2486 key.objectid = btrfs_ino(inode);
2487 key.type = BTRFS_EXTENT_DATA_KEY;
2488 key.offset = new->file_pos;
2489
2490 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2491 if (ret < 0)
2492 goto out_free_path;
2493 if (ret > 0 && path->slots[0] > 0)
2494 path->slots[0]--;
2495
2496 /* find out all the old extents for the file range */
2497 while (1) {
2498 struct btrfs_file_extent_item *extent;
2499 struct extent_buffer *l;
2500 int slot;
2501 u64 num_bytes;
2502 u64 offset;
2503 u64 end;
2504 u64 disk_bytenr;
2505 u64 extent_offset;
2506
2507 l = path->nodes[0];
2508 slot = path->slots[0];
2509
2510 if (slot >= btrfs_header_nritems(l)) {
2511 ret = btrfs_next_leaf(root, path);
2512 if (ret < 0)
2513 goto out_free_path;
2514 else if (ret > 0)
2515 break;
2516 continue;
2517 }
2518
2519 btrfs_item_key_to_cpu(l, &key, slot);
2520
2521 if (key.objectid != btrfs_ino(inode))
2522 break;
2523 if (key.type != BTRFS_EXTENT_DATA_KEY)
2524 break;
2525 if (key.offset >= new->file_pos + new->len)
2526 break;
2527
2528 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2529
2530 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2531 if (key.offset + num_bytes < new->file_pos)
2532 goto next;
2533
2534 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2535 if (!disk_bytenr)
2536 goto next;
2537
2538 extent_offset = btrfs_file_extent_offset(l, extent);
2539
2540 old = kmalloc(sizeof(*old), GFP_NOFS);
2541 if (!old)
2542 goto out_free_path;
2543
2544 offset = max(new->file_pos, key.offset);
2545 end = min(new->file_pos + new->len, key.offset + num_bytes);
2546
2547 old->bytenr = disk_bytenr;
2548 old->extent_offset = extent_offset;
2549 old->offset = offset - key.offset;
2550 old->len = end - offset;
2551 old->new = new;
2552 old->count = 0;
2553 list_add_tail(&old->list, &new->head);
2554 next:
2555 path->slots[0]++;
2556 cond_resched();
2557 }
2558
2559 btrfs_free_path(path);
2560 atomic_inc(&root->fs_info->defrag_running);
2561
2562 return new;
2563
2564 out_free_path:
2565 btrfs_free_path(path);
2566 out_kfree:
2567 free_sa_defrag_extent(new);
2568 return NULL;
2569 }
2570
2571 /* as ordered data IO finishes, this gets called so we can finish
2572 * an ordered extent if the range of bytes in the file it covers are
2573 * fully written.
2574 */
2575 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2576 {
2577 struct inode *inode = ordered_extent->inode;
2578 struct btrfs_root *root = BTRFS_I(inode)->root;
2579 struct btrfs_trans_handle *trans = NULL;
2580 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2581 struct extent_state *cached_state = NULL;
2582 struct new_sa_defrag_extent *new = NULL;
2583 int compress_type = 0;
2584 int ret = 0;
2585 u64 logical_len = ordered_extent->len;
2586 bool nolock;
2587 bool truncated = false;
2588
2589 nolock = btrfs_is_free_space_inode(inode);
2590
2591 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2592 ret = -EIO;
2593 goto out;
2594 }
2595
2596 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2597 truncated = true;
2598 logical_len = ordered_extent->truncated_len;
2599 /* Truncated the entire extent, don't bother adding */
2600 if (!logical_len)
2601 goto out;
2602 }
2603
2604 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2605 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2606 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2607 if (nolock)
2608 trans = btrfs_join_transaction_nolock(root);
2609 else
2610 trans = btrfs_join_transaction(root);
2611 if (IS_ERR(trans)) {
2612 ret = PTR_ERR(trans);
2613 trans = NULL;
2614 goto out;
2615 }
2616 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2617 ret = btrfs_update_inode_fallback(trans, root, inode);
2618 if (ret) /* -ENOMEM or corruption */
2619 btrfs_abort_transaction(trans, root, ret);
2620 goto out;
2621 }
2622
2623 lock_extent_bits(io_tree, ordered_extent->file_offset,
2624 ordered_extent->file_offset + ordered_extent->len - 1,
2625 0, &cached_state);
2626
2627 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2628 ordered_extent->file_offset + ordered_extent->len - 1,
2629 EXTENT_DEFRAG, 1, cached_state);
2630 if (ret) {
2631 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2632 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
2633 /* the inode is shared */
2634 new = record_old_file_extents(inode, ordered_extent);
2635
2636 clear_extent_bit(io_tree, ordered_extent->file_offset,
2637 ordered_extent->file_offset + ordered_extent->len - 1,
2638 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2639 }
2640
2641 if (nolock)
2642 trans = btrfs_join_transaction_nolock(root);
2643 else
2644 trans = btrfs_join_transaction(root);
2645 if (IS_ERR(trans)) {
2646 ret = PTR_ERR(trans);
2647 trans = NULL;
2648 goto out_unlock;
2649 }
2650 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2651
2652 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2653 compress_type = ordered_extent->compress_type;
2654 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2655 BUG_ON(compress_type);
2656 ret = btrfs_mark_extent_written(trans, inode,
2657 ordered_extent->file_offset,
2658 ordered_extent->file_offset +
2659 logical_len);
2660 } else {
2661 BUG_ON(root == root->fs_info->tree_root);
2662 ret = insert_reserved_file_extent(trans, inode,
2663 ordered_extent->file_offset,
2664 ordered_extent->start,
2665 ordered_extent->disk_len,
2666 logical_len, logical_len,
2667 compress_type, 0, 0,
2668 BTRFS_FILE_EXTENT_REG);
2669 }
2670 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2671 ordered_extent->file_offset, ordered_extent->len,
2672 trans->transid);
2673 if (ret < 0) {
2674 btrfs_abort_transaction(trans, root, ret);
2675 goto out_unlock;
2676 }
2677
2678 add_pending_csums(trans, inode, ordered_extent->file_offset,
2679 &ordered_extent->list);
2680
2681 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2682 ret = btrfs_update_inode_fallback(trans, root, inode);
2683 if (ret) { /* -ENOMEM or corruption */
2684 btrfs_abort_transaction(trans, root, ret);
2685 goto out_unlock;
2686 }
2687 ret = 0;
2688 out_unlock:
2689 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2690 ordered_extent->file_offset +
2691 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2692 out:
2693 if (root != root->fs_info->tree_root)
2694 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2695 if (trans)
2696 btrfs_end_transaction(trans, root);
2697
2698 if (ret || truncated) {
2699 u64 start, end;
2700
2701 if (truncated)
2702 start = ordered_extent->file_offset + logical_len;
2703 else
2704 start = ordered_extent->file_offset;
2705 end = ordered_extent->file_offset + ordered_extent->len - 1;
2706 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
2707
2708 /* Drop the cache for the part of the extent we didn't write. */
2709 btrfs_drop_extent_cache(inode, start, end, 0);
2710
2711 /*
2712 * If the ordered extent had an IOERR or something else went
2713 * wrong we need to return the space for this ordered extent
2714 * back to the allocator. We only free the extent in the
2715 * truncated case if we didn't write out the extent at all.
2716 */
2717 if ((ret || !logical_len) &&
2718 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2719 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
2720 btrfs_free_reserved_extent(root, ordered_extent->start,
2721 ordered_extent->disk_len);
2722 }
2723
2724
2725 /*
2726 * This needs to be done to make sure anybody waiting knows we are done
2727 * updating everything for this ordered extent.
2728 */
2729 btrfs_remove_ordered_extent(inode, ordered_extent);
2730
2731 /* for snapshot-aware defrag */
2732 if (new) {
2733 if (ret) {
2734 free_sa_defrag_extent(new);
2735 atomic_dec(&root->fs_info->defrag_running);
2736 } else {
2737 relink_file_extents(new);
2738 }
2739 }
2740
2741 /* once for us */
2742 btrfs_put_ordered_extent(ordered_extent);
2743 /* once for the tree */
2744 btrfs_put_ordered_extent(ordered_extent);
2745
2746 return ret;
2747 }
2748
2749 static void finish_ordered_fn(struct btrfs_work *work)
2750 {
2751 struct btrfs_ordered_extent *ordered_extent;
2752 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
2753 btrfs_finish_ordered_io(ordered_extent);
2754 }
2755
2756 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
2757 struct extent_state *state, int uptodate)
2758 {
2759 struct inode *inode = page->mapping->host;
2760 struct btrfs_root *root = BTRFS_I(inode)->root;
2761 struct btrfs_ordered_extent *ordered_extent = NULL;
2762 struct btrfs_workers *workers;
2763
2764 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
2765
2766 ClearPagePrivate2(page);
2767 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
2768 end - start + 1, uptodate))
2769 return 0;
2770
2771 ordered_extent->work.func = finish_ordered_fn;
2772 ordered_extent->work.flags = 0;
2773
2774 if (btrfs_is_free_space_inode(inode))
2775 workers = &root->fs_info->endio_freespace_worker;
2776 else
2777 workers = &root->fs_info->endio_write_workers;
2778 btrfs_queue_worker(workers, &ordered_extent->work);
2779
2780 return 0;
2781 }
2782
2783 /*
2784 * when reads are done, we need to check csums to verify the data is correct
2785 * if there's a match, we allow the bio to finish. If not, the code in
2786 * extent_io.c will try to find good copies for us.
2787 */
2788 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
2789 u64 phy_offset, struct page *page,
2790 u64 start, u64 end, int mirror)
2791 {
2792 size_t offset = start - page_offset(page);
2793 struct inode *inode = page->mapping->host;
2794 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2795 char *kaddr;
2796 struct btrfs_root *root = BTRFS_I(inode)->root;
2797 u32 csum_expected;
2798 u32 csum = ~(u32)0;
2799 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
2800 DEFAULT_RATELIMIT_BURST);
2801
2802 if (PageChecked(page)) {
2803 ClearPageChecked(page);
2804 goto good;
2805 }
2806
2807 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
2808 goto good;
2809
2810 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
2811 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
2812 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
2813 GFP_NOFS);
2814 return 0;
2815 }
2816
2817 phy_offset >>= inode->i_sb->s_blocksize_bits;
2818 csum_expected = *(((u32 *)io_bio->csum) + phy_offset);
2819
2820 kaddr = kmap_atomic(page);
2821 csum = btrfs_csum_data(kaddr + offset, csum, end - start + 1);
2822 btrfs_csum_final(csum, (char *)&csum);
2823 if (csum != csum_expected)
2824 goto zeroit;
2825
2826 kunmap_atomic(kaddr);
2827 good:
2828 return 0;
2829
2830 zeroit:
2831 if (__ratelimit(&_rs))
2832 btrfs_info(root->fs_info, "csum failed ino %llu off %llu csum %u expected csum %u",
2833 btrfs_ino(page->mapping->host), start, csum, csum_expected);
2834 memset(kaddr + offset, 1, end - start + 1);
2835 flush_dcache_page(page);
2836 kunmap_atomic(kaddr);
2837 if (csum_expected == 0)
2838 return 0;
2839 return -EIO;
2840 }
2841
2842 struct delayed_iput {
2843 struct list_head list;
2844 struct inode *inode;
2845 };
2846
2847 /* JDM: If this is fs-wide, why can't we add a pointer to
2848 * btrfs_inode instead and avoid the allocation? */
2849 void btrfs_add_delayed_iput(struct inode *inode)
2850 {
2851 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2852 struct delayed_iput *delayed;
2853
2854 if (atomic_add_unless(&inode->i_count, -1, 1))
2855 return;
2856
2857 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
2858 delayed->inode = inode;
2859
2860 spin_lock(&fs_info->delayed_iput_lock);
2861 list_add_tail(&delayed->list, &fs_info->delayed_iputs);
2862 spin_unlock(&fs_info->delayed_iput_lock);
2863 }
2864
2865 void btrfs_run_delayed_iputs(struct btrfs_root *root)
2866 {
2867 LIST_HEAD(list);
2868 struct btrfs_fs_info *fs_info = root->fs_info;
2869 struct delayed_iput *delayed;
2870 int empty;
2871
2872 spin_lock(&fs_info->delayed_iput_lock);
2873 empty = list_empty(&fs_info->delayed_iputs);
2874 spin_unlock(&fs_info->delayed_iput_lock);
2875 if (empty)
2876 return;
2877
2878 spin_lock(&fs_info->delayed_iput_lock);
2879 list_splice_init(&fs_info->delayed_iputs, &list);
2880 spin_unlock(&fs_info->delayed_iput_lock);
2881
2882 while (!list_empty(&list)) {
2883 delayed = list_entry(list.next, struct delayed_iput, list);
2884 list_del(&delayed->list);
2885 iput(delayed->inode);
2886 kfree(delayed);
2887 }
2888 }
2889
2890 /*
2891 * This is called in transaction commit time. If there are no orphan
2892 * files in the subvolume, it removes orphan item and frees block_rsv
2893 * structure.
2894 */
2895 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
2896 struct btrfs_root *root)
2897 {
2898 struct btrfs_block_rsv *block_rsv;
2899 int ret;
2900
2901 if (atomic_read(&root->orphan_inodes) ||
2902 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
2903 return;
2904
2905 spin_lock(&root->orphan_lock);
2906 if (atomic_read(&root->orphan_inodes)) {
2907 spin_unlock(&root->orphan_lock);
2908 return;
2909 }
2910
2911 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
2912 spin_unlock(&root->orphan_lock);
2913 return;
2914 }
2915
2916 block_rsv = root->orphan_block_rsv;
2917 root->orphan_block_rsv = NULL;
2918 spin_unlock(&root->orphan_lock);
2919
2920 if (root->orphan_item_inserted &&
2921 btrfs_root_refs(&root->root_item) > 0) {
2922 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
2923 root->root_key.objectid);
2924 if (ret)
2925 btrfs_abort_transaction(trans, root, ret);
2926 else
2927 root->orphan_item_inserted = 0;
2928 }
2929
2930 if (block_rsv) {
2931 WARN_ON(block_rsv->size > 0);
2932 btrfs_free_block_rsv(root, block_rsv);
2933 }
2934 }
2935
2936 /*
2937 * This creates an orphan entry for the given inode in case something goes
2938 * wrong in the middle of an unlink/truncate.
2939 *
2940 * NOTE: caller of this function should reserve 5 units of metadata for
2941 * this function.
2942 */
2943 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
2944 {
2945 struct btrfs_root *root = BTRFS_I(inode)->root;
2946 struct btrfs_block_rsv *block_rsv = NULL;
2947 int reserve = 0;
2948 int insert = 0;
2949 int ret;
2950
2951 if (!root->orphan_block_rsv) {
2952 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
2953 if (!block_rsv)
2954 return -ENOMEM;
2955 }
2956
2957 spin_lock(&root->orphan_lock);
2958 if (!root->orphan_block_rsv) {
2959 root->orphan_block_rsv = block_rsv;
2960 } else if (block_rsv) {
2961 btrfs_free_block_rsv(root, block_rsv);
2962 block_rsv = NULL;
2963 }
2964
2965 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
2966 &BTRFS_I(inode)->runtime_flags)) {
2967 #if 0
2968 /*
2969 * For proper ENOSPC handling, we should do orphan
2970 * cleanup when mounting. But this introduces backward
2971 * compatibility issue.
2972 */
2973 if (!xchg(&root->orphan_item_inserted, 1))
2974 insert = 2;
2975 else
2976 insert = 1;
2977 #endif
2978 insert = 1;
2979 atomic_inc(&root->orphan_inodes);
2980 }
2981
2982 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
2983 &BTRFS_I(inode)->runtime_flags))
2984 reserve = 1;
2985 spin_unlock(&root->orphan_lock);
2986
2987 /* grab metadata reservation from transaction handle */
2988 if (reserve) {
2989 ret = btrfs_orphan_reserve_metadata(trans, inode);
2990 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
2991 }
2992
2993 /* insert an orphan item to track this unlinked/truncated file */
2994 if (insert >= 1) {
2995 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
2996 if (ret) {
2997 atomic_dec(&root->orphan_inodes);
2998 if (reserve) {
2999 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3000 &BTRFS_I(inode)->runtime_flags);
3001 btrfs_orphan_release_metadata(inode);
3002 }
3003 if (ret != -EEXIST) {
3004 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3005 &BTRFS_I(inode)->runtime_flags);
3006 btrfs_abort_transaction(trans, root, ret);
3007 return ret;
3008 }
3009 }
3010 ret = 0;
3011 }
3012
3013 /* insert an orphan item to track subvolume contains orphan files */
3014 if (insert >= 2) {
3015 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
3016 root->root_key.objectid);
3017 if (ret && ret != -EEXIST) {
3018 btrfs_abort_transaction(trans, root, ret);
3019 return ret;
3020 }
3021 }
3022 return 0;
3023 }
3024
3025 /*
3026 * We have done the truncate/delete so we can go ahead and remove the orphan
3027 * item for this particular inode.
3028 */
3029 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3030 struct inode *inode)
3031 {
3032 struct btrfs_root *root = BTRFS_I(inode)->root;
3033 int delete_item = 0;
3034 int release_rsv = 0;
3035 int ret = 0;
3036
3037 spin_lock(&root->orphan_lock);
3038 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3039 &BTRFS_I(inode)->runtime_flags))
3040 delete_item = 1;
3041
3042 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3043 &BTRFS_I(inode)->runtime_flags))
3044 release_rsv = 1;
3045 spin_unlock(&root->orphan_lock);
3046
3047 if (delete_item) {
3048 atomic_dec(&root->orphan_inodes);
3049 if (trans)
3050 ret = btrfs_del_orphan_item(trans, root,
3051 btrfs_ino(inode));
3052 }
3053
3054 if (release_rsv)
3055 btrfs_orphan_release_metadata(inode);
3056
3057 return ret;
3058 }
3059
3060 /*
3061 * this cleans up any orphans that may be left on the list from the last use
3062 * of this root.
3063 */
3064 int btrfs_orphan_cleanup(struct btrfs_root *root)
3065 {
3066 struct btrfs_path *path;
3067 struct extent_buffer *leaf;
3068 struct btrfs_key key, found_key;
3069 struct btrfs_trans_handle *trans;
3070 struct inode *inode;
3071 u64 last_objectid = 0;
3072 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3073
3074 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3075 return 0;
3076
3077 path = btrfs_alloc_path();
3078 if (!path) {
3079 ret = -ENOMEM;
3080 goto out;
3081 }
3082 path->reada = -1;
3083
3084 key.objectid = BTRFS_ORPHAN_OBJECTID;
3085 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
3086 key.offset = (u64)-1;
3087
3088 while (1) {
3089 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3090 if (ret < 0)
3091 goto out;
3092
3093 /*
3094 * if ret == 0 means we found what we were searching for, which
3095 * is weird, but possible, so only screw with path if we didn't
3096 * find the key and see if we have stuff that matches
3097 */
3098 if (ret > 0) {
3099 ret = 0;
3100 if (path->slots[0] == 0)
3101 break;
3102 path->slots[0]--;
3103 }
3104
3105 /* pull out the item */
3106 leaf = path->nodes[0];
3107 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3108
3109 /* make sure the item matches what we want */
3110 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3111 break;
3112 if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
3113 break;
3114
3115 /* release the path since we're done with it */
3116 btrfs_release_path(path);
3117
3118 /*
3119 * this is where we are basically btrfs_lookup, without the
3120 * crossing root thing. we store the inode number in the
3121 * offset of the orphan item.
3122 */
3123
3124 if (found_key.offset == last_objectid) {
3125 btrfs_err(root->fs_info,
3126 "Error removing orphan entry, stopping orphan cleanup");
3127 ret = -EINVAL;
3128 goto out;
3129 }
3130
3131 last_objectid = found_key.offset;
3132
3133 found_key.objectid = found_key.offset;
3134 found_key.type = BTRFS_INODE_ITEM_KEY;
3135 found_key.offset = 0;
3136 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3137 ret = PTR_ERR_OR_ZERO(inode);
3138 if (ret && ret != -ESTALE)
3139 goto out;
3140
3141 if (ret == -ESTALE && root == root->fs_info->tree_root) {
3142 struct btrfs_root *dead_root;
3143 struct btrfs_fs_info *fs_info = root->fs_info;
3144 int is_dead_root = 0;
3145
3146 /*
3147 * this is an orphan in the tree root. Currently these
3148 * could come from 2 sources:
3149 * a) a snapshot deletion in progress
3150 * b) a free space cache inode
3151 * We need to distinguish those two, as the snapshot
3152 * orphan must not get deleted.
3153 * find_dead_roots already ran before us, so if this
3154 * is a snapshot deletion, we should find the root
3155 * in the dead_roots list
3156 */
3157 spin_lock(&fs_info->trans_lock);
3158 list_for_each_entry(dead_root, &fs_info->dead_roots,
3159 root_list) {
3160 if (dead_root->root_key.objectid ==
3161 found_key.objectid) {
3162 is_dead_root = 1;
3163 break;
3164 }
3165 }
3166 spin_unlock(&fs_info->trans_lock);
3167 if (is_dead_root) {
3168 /* prevent this orphan from being found again */
3169 key.offset = found_key.objectid - 1;
3170 continue;
3171 }
3172 }
3173 /*
3174 * Inode is already gone but the orphan item is still there,
3175 * kill the orphan item.
3176 */
3177 if (ret == -ESTALE) {
3178 trans = btrfs_start_transaction(root, 1);
3179 if (IS_ERR(trans)) {
3180 ret = PTR_ERR(trans);
3181 goto out;
3182 }
3183 btrfs_debug(root->fs_info, "auto deleting %Lu",
3184 found_key.objectid);
3185 ret = btrfs_del_orphan_item(trans, root,
3186 found_key.objectid);
3187 btrfs_end_transaction(trans, root);
3188 if (ret)
3189 goto out;
3190 continue;
3191 }
3192
3193 /*
3194 * add this inode to the orphan list so btrfs_orphan_del does
3195 * the proper thing when we hit it
3196 */
3197 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3198 &BTRFS_I(inode)->runtime_flags);
3199 atomic_inc(&root->orphan_inodes);
3200
3201 /* if we have links, this was a truncate, lets do that */
3202 if (inode->i_nlink) {
3203 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3204 iput(inode);
3205 continue;
3206 }
3207 nr_truncate++;
3208
3209 /* 1 for the orphan item deletion. */
3210 trans = btrfs_start_transaction(root, 1);
3211 if (IS_ERR(trans)) {
3212 iput(inode);
3213 ret = PTR_ERR(trans);
3214 goto out;
3215 }
3216 ret = btrfs_orphan_add(trans, inode);
3217 btrfs_end_transaction(trans, root);
3218 if (ret) {
3219 iput(inode);
3220 goto out;
3221 }
3222
3223 ret = btrfs_truncate(inode);
3224 if (ret)
3225 btrfs_orphan_del(NULL, inode);
3226 } else {
3227 nr_unlink++;
3228 }
3229
3230 /* this will do delete_inode and everything for us */
3231 iput(inode);
3232 if (ret)
3233 goto out;
3234 }
3235 /* release the path since we're done with it */
3236 btrfs_release_path(path);
3237
3238 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3239
3240 if (root->orphan_block_rsv)
3241 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3242 (u64)-1);
3243
3244 if (root->orphan_block_rsv || root->orphan_item_inserted) {
3245 trans = btrfs_join_transaction(root);
3246 if (!IS_ERR(trans))
3247 btrfs_end_transaction(trans, root);
3248 }
3249
3250 if (nr_unlink)
3251 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3252 if (nr_truncate)
3253 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3254
3255 out:
3256 if (ret)
3257 btrfs_crit(root->fs_info,
3258 "could not do orphan cleanup %d", ret);
3259 btrfs_free_path(path);
3260 return ret;
3261 }
3262
3263 /*
3264 * very simple check to peek ahead in the leaf looking for xattrs. If we
3265 * don't find any xattrs, we know there can't be any acls.
3266 *
3267 * slot is the slot the inode is in, objectid is the objectid of the inode
3268 */
3269 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3270 int slot, u64 objectid,
3271 int *first_xattr_slot)
3272 {
3273 u32 nritems = btrfs_header_nritems(leaf);
3274 struct btrfs_key found_key;
3275 static u64 xattr_access = 0;
3276 static u64 xattr_default = 0;
3277 int scanned = 0;
3278
3279 if (!xattr_access) {
3280 xattr_access = btrfs_name_hash(POSIX_ACL_XATTR_ACCESS,
3281 strlen(POSIX_ACL_XATTR_ACCESS));
3282 xattr_default = btrfs_name_hash(POSIX_ACL_XATTR_DEFAULT,
3283 strlen(POSIX_ACL_XATTR_DEFAULT));
3284 }
3285
3286 slot++;
3287 *first_xattr_slot = -1;
3288 while (slot < nritems) {
3289 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3290
3291 /* we found a different objectid, there must not be acls */
3292 if (found_key.objectid != objectid)
3293 return 0;
3294
3295 /* we found an xattr, assume we've got an acl */
3296 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3297 if (*first_xattr_slot == -1)
3298 *first_xattr_slot = slot;
3299 if (found_key.offset == xattr_access ||
3300 found_key.offset == xattr_default)
3301 return 1;
3302 }
3303
3304 /*
3305 * we found a key greater than an xattr key, there can't
3306 * be any acls later on
3307 */
3308 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3309 return 0;
3310
3311 slot++;
3312 scanned++;
3313
3314 /*
3315 * it goes inode, inode backrefs, xattrs, extents,
3316 * so if there are a ton of hard links to an inode there can
3317 * be a lot of backrefs. Don't waste time searching too hard,
3318 * this is just an optimization
3319 */
3320 if (scanned >= 8)
3321 break;
3322 }
3323 /* we hit the end of the leaf before we found an xattr or
3324 * something larger than an xattr. We have to assume the inode
3325 * has acls
3326 */
3327 if (*first_xattr_slot == -1)
3328 *first_xattr_slot = slot;
3329 return 1;
3330 }
3331
3332 /*
3333 * read an inode from the btree into the in-memory inode
3334 */
3335 static void btrfs_read_locked_inode(struct inode *inode)
3336 {
3337 struct btrfs_path *path;
3338 struct extent_buffer *leaf;
3339 struct btrfs_inode_item *inode_item;
3340 struct btrfs_timespec *tspec;
3341 struct btrfs_root *root = BTRFS_I(inode)->root;
3342 struct btrfs_key location;
3343 unsigned long ptr;
3344 int maybe_acls;
3345 u32 rdev;
3346 int ret;
3347 bool filled = false;
3348 int first_xattr_slot;
3349
3350 ret = btrfs_fill_inode(inode, &rdev);
3351 if (!ret)
3352 filled = true;
3353
3354 path = btrfs_alloc_path();
3355 if (!path)
3356 goto make_bad;
3357
3358 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3359
3360 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3361 if (ret)
3362 goto make_bad;
3363
3364 leaf = path->nodes[0];
3365
3366 if (filled)
3367 goto cache_index;
3368
3369 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3370 struct btrfs_inode_item);
3371 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3372 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3373 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3374 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3375 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3376
3377 tspec = btrfs_inode_atime(inode_item);
3378 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3379 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3380
3381 tspec = btrfs_inode_mtime(inode_item);
3382 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3383 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3384
3385 tspec = btrfs_inode_ctime(inode_item);
3386 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3387 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3388
3389 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3390 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3391 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3392
3393 /*
3394 * If we were modified in the current generation and evicted from memory
3395 * and then re-read we need to do a full sync since we don't have any
3396 * idea about which extents were modified before we were evicted from
3397 * cache.
3398 */
3399 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3400 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3401 &BTRFS_I(inode)->runtime_flags);
3402
3403 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3404 inode->i_generation = BTRFS_I(inode)->generation;
3405 inode->i_rdev = 0;
3406 rdev = btrfs_inode_rdev(leaf, inode_item);
3407
3408 BTRFS_I(inode)->index_cnt = (u64)-1;
3409 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3410
3411 cache_index:
3412 path->slots[0]++;
3413 if (inode->i_nlink != 1 ||
3414 path->slots[0] >= btrfs_header_nritems(leaf))
3415 goto cache_acl;
3416
3417 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3418 if (location.objectid != btrfs_ino(inode))
3419 goto cache_acl;
3420
3421 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3422 if (location.type == BTRFS_INODE_REF_KEY) {
3423 struct btrfs_inode_ref *ref;
3424
3425 ref = (struct btrfs_inode_ref *)ptr;
3426 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3427 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3428 struct btrfs_inode_extref *extref;
3429
3430 extref = (struct btrfs_inode_extref *)ptr;
3431 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3432 extref);
3433 }
3434 cache_acl:
3435 /*
3436 * try to precache a NULL acl entry for files that don't have
3437 * any xattrs or acls
3438 */
3439 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3440 btrfs_ino(inode), &first_xattr_slot);
3441 if (first_xattr_slot != -1) {
3442 path->slots[0] = first_xattr_slot;
3443 ret = btrfs_load_inode_props(inode, path);
3444 if (ret)
3445 btrfs_err(root->fs_info,
3446 "error loading props for ino %llu (root %llu): %d\n",
3447 btrfs_ino(inode),
3448 root->root_key.objectid, ret);
3449 }
3450 btrfs_free_path(path);
3451
3452 if (!maybe_acls)
3453 cache_no_acl(inode);
3454
3455 switch (inode->i_mode & S_IFMT) {
3456 case S_IFREG:
3457 inode->i_mapping->a_ops = &btrfs_aops;
3458 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3459 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3460 inode->i_fop = &btrfs_file_operations;
3461 inode->i_op = &btrfs_file_inode_operations;
3462 break;
3463 case S_IFDIR:
3464 inode->i_fop = &btrfs_dir_file_operations;
3465 if (root == root->fs_info->tree_root)
3466 inode->i_op = &btrfs_dir_ro_inode_operations;
3467 else
3468 inode->i_op = &btrfs_dir_inode_operations;
3469 break;
3470 case S_IFLNK:
3471 inode->i_op = &btrfs_symlink_inode_operations;
3472 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3473 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3474 break;
3475 default:
3476 inode->i_op = &btrfs_special_inode_operations;
3477 init_special_inode(inode, inode->i_mode, rdev);
3478 break;
3479 }
3480
3481 btrfs_update_iflags(inode);
3482 return;
3483
3484 make_bad:
3485 btrfs_free_path(path);
3486 make_bad_inode(inode);
3487 }
3488
3489 /*
3490 * given a leaf and an inode, copy the inode fields into the leaf
3491 */
3492 static void fill_inode_item(struct btrfs_trans_handle *trans,
3493 struct extent_buffer *leaf,
3494 struct btrfs_inode_item *item,
3495 struct inode *inode)
3496 {
3497 struct btrfs_map_token token;
3498
3499 btrfs_init_map_token(&token);
3500
3501 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3502 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3503 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3504 &token);
3505 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3506 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3507
3508 btrfs_set_token_timespec_sec(leaf, btrfs_inode_atime(item),
3509 inode->i_atime.tv_sec, &token);
3510 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_atime(item),
3511 inode->i_atime.tv_nsec, &token);
3512
3513 btrfs_set_token_timespec_sec(leaf, btrfs_inode_mtime(item),
3514 inode->i_mtime.tv_sec, &token);
3515 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_mtime(item),
3516 inode->i_mtime.tv_nsec, &token);
3517
3518 btrfs_set_token_timespec_sec(leaf, btrfs_inode_ctime(item),
3519 inode->i_ctime.tv_sec, &token);
3520 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_ctime(item),
3521 inode->i_ctime.tv_nsec, &token);
3522
3523 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3524 &token);
3525 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3526 &token);
3527 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3528 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3529 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3530 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3531 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3532 }
3533
3534 /*
3535 * copy everything in the in-memory inode into the btree.
3536 */
3537 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3538 struct btrfs_root *root, struct inode *inode)
3539 {
3540 struct btrfs_inode_item *inode_item;
3541 struct btrfs_path *path;
3542 struct extent_buffer *leaf;
3543 int ret;
3544
3545 path = btrfs_alloc_path();
3546 if (!path)
3547 return -ENOMEM;
3548
3549 path->leave_spinning = 1;
3550 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3551 1);
3552 if (ret) {
3553 if (ret > 0)
3554 ret = -ENOENT;
3555 goto failed;
3556 }
3557
3558 leaf = path->nodes[0];
3559 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3560 struct btrfs_inode_item);
3561
3562 fill_inode_item(trans, leaf, inode_item, inode);
3563 btrfs_mark_buffer_dirty(leaf);
3564 btrfs_set_inode_last_trans(trans, inode);
3565 ret = 0;
3566 failed:
3567 btrfs_free_path(path);
3568 return ret;
3569 }
3570
3571 /*
3572 * copy everything in the in-memory inode into the btree.
3573 */
3574 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3575 struct btrfs_root *root, struct inode *inode)
3576 {
3577 int ret;
3578
3579 /*
3580 * If the inode is a free space inode, we can deadlock during commit
3581 * if we put it into the delayed code.
3582 *
3583 * The data relocation inode should also be directly updated
3584 * without delay
3585 */
3586 if (!btrfs_is_free_space_inode(inode)
3587 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) {
3588 btrfs_update_root_times(trans, root);
3589
3590 ret = btrfs_delayed_update_inode(trans, root, inode);
3591 if (!ret)
3592 btrfs_set_inode_last_trans(trans, inode);
3593 return ret;
3594 }
3595
3596 return btrfs_update_inode_item(trans, root, inode);
3597 }
3598
3599 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3600 struct btrfs_root *root,
3601 struct inode *inode)
3602 {
3603 int ret;
3604
3605 ret = btrfs_update_inode(trans, root, inode);
3606 if (ret == -ENOSPC)
3607 return btrfs_update_inode_item(trans, root, inode);
3608 return ret;
3609 }
3610
3611 /*
3612 * unlink helper that gets used here in inode.c and in the tree logging
3613 * recovery code. It remove a link in a directory with a given name, and
3614 * also drops the back refs in the inode to the directory
3615 */
3616 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3617 struct btrfs_root *root,
3618 struct inode *dir, struct inode *inode,
3619 const char *name, int name_len)
3620 {
3621 struct btrfs_path *path;
3622 int ret = 0;
3623 struct extent_buffer *leaf;
3624 struct btrfs_dir_item *di;
3625 struct btrfs_key key;
3626 u64 index;
3627 u64 ino = btrfs_ino(inode);
3628 u64 dir_ino = btrfs_ino(dir);
3629
3630 path = btrfs_alloc_path();
3631 if (!path) {
3632 ret = -ENOMEM;
3633 goto out;
3634 }
3635
3636 path->leave_spinning = 1;
3637 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3638 name, name_len, -1);
3639 if (IS_ERR(di)) {
3640 ret = PTR_ERR(di);
3641 goto err;
3642 }
3643 if (!di) {
3644 ret = -ENOENT;
3645 goto err;
3646 }
3647 leaf = path->nodes[0];
3648 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3649 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3650 if (ret)
3651 goto err;
3652 btrfs_release_path(path);
3653
3654 /*
3655 * If we don't have dir index, we have to get it by looking up
3656 * the inode ref, since we get the inode ref, remove it directly,
3657 * it is unnecessary to do delayed deletion.
3658 *
3659 * But if we have dir index, needn't search inode ref to get it.
3660 * Since the inode ref is close to the inode item, it is better
3661 * that we delay to delete it, and just do this deletion when
3662 * we update the inode item.
3663 */
3664 if (BTRFS_I(inode)->dir_index) {
3665 ret = btrfs_delayed_delete_inode_ref(inode);
3666 if (!ret) {
3667 index = BTRFS_I(inode)->dir_index;
3668 goto skip_backref;
3669 }
3670 }
3671
3672 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
3673 dir_ino, &index);
3674 if (ret) {
3675 btrfs_info(root->fs_info,
3676 "failed to delete reference to %.*s, inode %llu parent %llu",
3677 name_len, name, ino, dir_ino);
3678 btrfs_abort_transaction(trans, root, ret);
3679 goto err;
3680 }
3681 skip_backref:
3682 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3683 if (ret) {
3684 btrfs_abort_transaction(trans, root, ret);
3685 goto err;
3686 }
3687
3688 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
3689 inode, dir_ino);
3690 if (ret != 0 && ret != -ENOENT) {
3691 btrfs_abort_transaction(trans, root, ret);
3692 goto err;
3693 }
3694
3695 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
3696 dir, index);
3697 if (ret == -ENOENT)
3698 ret = 0;
3699 else if (ret)
3700 btrfs_abort_transaction(trans, root, ret);
3701 err:
3702 btrfs_free_path(path);
3703 if (ret)
3704 goto out;
3705
3706 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3707 inode_inc_iversion(inode);
3708 inode_inc_iversion(dir);
3709 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3710 ret = btrfs_update_inode(trans, root, dir);
3711 out:
3712 return ret;
3713 }
3714
3715 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3716 struct btrfs_root *root,
3717 struct inode *dir, struct inode *inode,
3718 const char *name, int name_len)
3719 {
3720 int ret;
3721 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
3722 if (!ret) {
3723 drop_nlink(inode);
3724 ret = btrfs_update_inode(trans, root, inode);
3725 }
3726 return ret;
3727 }
3728
3729 /*
3730 * helper to start transaction for unlink and rmdir.
3731 *
3732 * unlink and rmdir are special in btrfs, they do not always free space, so
3733 * if we cannot make our reservations the normal way try and see if there is
3734 * plenty of slack room in the global reserve to migrate, otherwise we cannot
3735 * allow the unlink to occur.
3736 */
3737 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
3738 {
3739 struct btrfs_trans_handle *trans;
3740 struct btrfs_root *root = BTRFS_I(dir)->root;
3741 int ret;
3742
3743 /*
3744 * 1 for the possible orphan item
3745 * 1 for the dir item
3746 * 1 for the dir index
3747 * 1 for the inode ref
3748 * 1 for the inode
3749 */
3750 trans = btrfs_start_transaction(root, 5);
3751 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
3752 return trans;
3753
3754 if (PTR_ERR(trans) == -ENOSPC) {
3755 u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5);
3756
3757 trans = btrfs_start_transaction(root, 0);
3758 if (IS_ERR(trans))
3759 return trans;
3760 ret = btrfs_cond_migrate_bytes(root->fs_info,
3761 &root->fs_info->trans_block_rsv,
3762 num_bytes, 5);
3763 if (ret) {
3764 btrfs_end_transaction(trans, root);
3765 return ERR_PTR(ret);
3766 }
3767 trans->block_rsv = &root->fs_info->trans_block_rsv;
3768 trans->bytes_reserved = num_bytes;
3769 }
3770 return trans;
3771 }
3772
3773 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
3774 {
3775 struct btrfs_root *root = BTRFS_I(dir)->root;
3776 struct btrfs_trans_handle *trans;
3777 struct inode *inode = dentry->d_inode;
3778 int ret;
3779
3780 trans = __unlink_start_trans(dir);
3781 if (IS_ERR(trans))
3782 return PTR_ERR(trans);
3783
3784 btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0);
3785
3786 ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3787 dentry->d_name.name, dentry->d_name.len);
3788 if (ret)
3789 goto out;
3790
3791 if (inode->i_nlink == 0) {
3792 ret = btrfs_orphan_add(trans, inode);
3793 if (ret)
3794 goto out;
3795 }
3796
3797 out:
3798 btrfs_end_transaction(trans, root);
3799 btrfs_btree_balance_dirty(root);
3800 return ret;
3801 }
3802
3803 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
3804 struct btrfs_root *root,
3805 struct inode *dir, u64 objectid,
3806 const char *name, int name_len)
3807 {
3808 struct btrfs_path *path;
3809 struct extent_buffer *leaf;
3810 struct btrfs_dir_item *di;
3811 struct btrfs_key key;
3812 u64 index;
3813 int ret;
3814 u64 dir_ino = btrfs_ino(dir);
3815
3816 path = btrfs_alloc_path();
3817 if (!path)
3818 return -ENOMEM;
3819
3820 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3821 name, name_len, -1);
3822 if (IS_ERR_OR_NULL(di)) {
3823 if (!di)
3824 ret = -ENOENT;
3825 else
3826 ret = PTR_ERR(di);
3827 goto out;
3828 }
3829
3830 leaf = path->nodes[0];
3831 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3832 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
3833 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3834 if (ret) {
3835 btrfs_abort_transaction(trans, root, ret);
3836 goto out;
3837 }
3838 btrfs_release_path(path);
3839
3840 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
3841 objectid, root->root_key.objectid,
3842 dir_ino, &index, name, name_len);
3843 if (ret < 0) {
3844 if (ret != -ENOENT) {
3845 btrfs_abort_transaction(trans, root, ret);
3846 goto out;
3847 }
3848 di = btrfs_search_dir_index_item(root, path, dir_ino,
3849 name, name_len);
3850 if (IS_ERR_OR_NULL(di)) {
3851 if (!di)
3852 ret = -ENOENT;
3853 else
3854 ret = PTR_ERR(di);
3855 btrfs_abort_transaction(trans, root, ret);
3856 goto out;
3857 }
3858
3859 leaf = path->nodes[0];
3860 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3861 btrfs_release_path(path);
3862 index = key.offset;
3863 }
3864 btrfs_release_path(path);
3865
3866 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3867 if (ret) {
3868 btrfs_abort_transaction(trans, root, ret);
3869 goto out;
3870 }
3871
3872 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3873 inode_inc_iversion(dir);
3874 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3875 ret = btrfs_update_inode_fallback(trans, root, dir);
3876 if (ret)
3877 btrfs_abort_transaction(trans, root, ret);
3878 out:
3879 btrfs_free_path(path);
3880 return ret;
3881 }
3882
3883 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
3884 {
3885 struct inode *inode = dentry->d_inode;
3886 int err = 0;
3887 struct btrfs_root *root = BTRFS_I(dir)->root;
3888 struct btrfs_trans_handle *trans;
3889
3890 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
3891 return -ENOTEMPTY;
3892 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
3893 return -EPERM;
3894
3895 trans = __unlink_start_trans(dir);
3896 if (IS_ERR(trans))
3897 return PTR_ERR(trans);
3898
3899 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
3900 err = btrfs_unlink_subvol(trans, root, dir,
3901 BTRFS_I(inode)->location.objectid,
3902 dentry->d_name.name,
3903 dentry->d_name.len);
3904 goto out;
3905 }
3906
3907 err = btrfs_orphan_add(trans, inode);
3908 if (err)
3909 goto out;
3910
3911 /* now the directory is empty */
3912 err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3913 dentry->d_name.name, dentry->d_name.len);
3914 if (!err)
3915 btrfs_i_size_write(inode, 0);
3916 out:
3917 btrfs_end_transaction(trans, root);
3918 btrfs_btree_balance_dirty(root);
3919
3920 return err;
3921 }
3922
3923 /*
3924 * this can truncate away extent items, csum items and directory items.
3925 * It starts at a high offset and removes keys until it can't find
3926 * any higher than new_size
3927 *
3928 * csum items that cross the new i_size are truncated to the new size
3929 * as well.
3930 *
3931 * min_type is the minimum key type to truncate down to. If set to 0, this
3932 * will kill all the items on this inode, including the INODE_ITEM_KEY.
3933 */
3934 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
3935 struct btrfs_root *root,
3936 struct inode *inode,
3937 u64 new_size, u32 min_type)
3938 {
3939 struct btrfs_path *path;
3940 struct extent_buffer *leaf;
3941 struct btrfs_file_extent_item *fi;
3942 struct btrfs_key key;
3943 struct btrfs_key found_key;
3944 u64 extent_start = 0;
3945 u64 extent_num_bytes = 0;
3946 u64 extent_offset = 0;
3947 u64 item_end = 0;
3948 u64 last_size = (u64)-1;
3949 u32 found_type = (u8)-1;
3950 int found_extent;
3951 int del_item;
3952 int pending_del_nr = 0;
3953 int pending_del_slot = 0;
3954 int extent_type = -1;
3955 int ret;
3956 int err = 0;
3957 u64 ino = btrfs_ino(inode);
3958
3959 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
3960
3961 path = btrfs_alloc_path();
3962 if (!path)
3963 return -ENOMEM;
3964 path->reada = -1;
3965
3966 /*
3967 * We want to drop from the next block forward in case this new size is
3968 * not block aligned since we will be keeping the last block of the
3969 * extent just the way it is.
3970 */
3971 if (root->ref_cows || root == root->fs_info->tree_root)
3972 btrfs_drop_extent_cache(inode, ALIGN(new_size,
3973 root->sectorsize), (u64)-1, 0);
3974
3975 /*
3976 * This function is also used to drop the items in the log tree before
3977 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
3978 * it is used to drop the loged items. So we shouldn't kill the delayed
3979 * items.
3980 */
3981 if (min_type == 0 && root == BTRFS_I(inode)->root)
3982 btrfs_kill_delayed_inode_items(inode);
3983
3984 key.objectid = ino;
3985 key.offset = (u64)-1;
3986 key.type = (u8)-1;
3987
3988 search_again:
3989 path->leave_spinning = 1;
3990 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3991 if (ret < 0) {
3992 err = ret;
3993 goto out;
3994 }
3995
3996 if (ret > 0) {
3997 /* there are no items in the tree for us to truncate, we're
3998 * done
3999 */
4000 if (path->slots[0] == 0)
4001 goto out;
4002 path->slots[0]--;
4003 }
4004
4005 while (1) {
4006 fi = NULL;
4007 leaf = path->nodes[0];
4008 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4009 found_type = btrfs_key_type(&found_key);
4010
4011 if (found_key.objectid != ino)
4012 break;
4013
4014 if (found_type < min_type)
4015 break;
4016
4017 item_end = found_key.offset;
4018 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4019 fi = btrfs_item_ptr(leaf, path->slots[0],
4020 struct btrfs_file_extent_item);
4021 extent_type = btrfs_file_extent_type(leaf, fi);
4022 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4023 item_end +=
4024 btrfs_file_extent_num_bytes(leaf, fi);
4025 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4026 item_end += btrfs_file_extent_inline_len(leaf,
4027 path->slots[0], fi);
4028 }
4029 item_end--;
4030 }
4031 if (found_type > min_type) {
4032 del_item = 1;
4033 } else {
4034 if (item_end < new_size)
4035 break;
4036 if (found_key.offset >= new_size)
4037 del_item = 1;
4038 else
4039 del_item = 0;
4040 }
4041 found_extent = 0;
4042 /* FIXME, shrink the extent if the ref count is only 1 */
4043 if (found_type != BTRFS_EXTENT_DATA_KEY)
4044 goto delete;
4045
4046 if (del_item)
4047 last_size = found_key.offset;
4048 else
4049 last_size = new_size;
4050
4051 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4052 u64 num_dec;
4053 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4054 if (!del_item) {
4055 u64 orig_num_bytes =
4056 btrfs_file_extent_num_bytes(leaf, fi);
4057 extent_num_bytes = ALIGN(new_size -
4058 found_key.offset,
4059 root->sectorsize);
4060 btrfs_set_file_extent_num_bytes(leaf, fi,
4061 extent_num_bytes);
4062 num_dec = (orig_num_bytes -
4063 extent_num_bytes);
4064 if (root->ref_cows && extent_start != 0)
4065 inode_sub_bytes(inode, num_dec);
4066 btrfs_mark_buffer_dirty(leaf);
4067 } else {
4068 extent_num_bytes =
4069 btrfs_file_extent_disk_num_bytes(leaf,
4070 fi);
4071 extent_offset = found_key.offset -
4072 btrfs_file_extent_offset(leaf, fi);
4073
4074 /* FIXME blocksize != 4096 */
4075 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4076 if (extent_start != 0) {
4077 found_extent = 1;
4078 if (root->ref_cows)
4079 inode_sub_bytes(inode, num_dec);
4080 }
4081 }
4082 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4083 /*
4084 * we can't truncate inline items that have had
4085 * special encodings
4086 */
4087 if (!del_item &&
4088 btrfs_file_extent_compression(leaf, fi) == 0 &&
4089 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4090 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4091 u32 size = new_size - found_key.offset;
4092
4093 if (root->ref_cows) {
4094 inode_sub_bytes(inode, item_end + 1 -
4095 new_size);
4096 }
4097
4098 /*
4099 * update the ram bytes to properly reflect
4100 * the new size of our item
4101 */
4102 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4103 size =
4104 btrfs_file_extent_calc_inline_size(size);
4105 btrfs_truncate_item(root, path, size, 1);
4106 } else if (root->ref_cows) {
4107 inode_sub_bytes(inode, item_end + 1 -
4108 found_key.offset);
4109 }
4110 }
4111 delete:
4112 if (del_item) {
4113 if (!pending_del_nr) {
4114 /* no pending yet, add ourselves */
4115 pending_del_slot = path->slots[0];
4116 pending_del_nr = 1;
4117 } else if (pending_del_nr &&
4118 path->slots[0] + 1 == pending_del_slot) {
4119 /* hop on the pending chunk */
4120 pending_del_nr++;
4121 pending_del_slot = path->slots[0];
4122 } else {
4123 BUG();
4124 }
4125 } else {
4126 break;
4127 }
4128 if (found_extent && (root->ref_cows ||
4129 root == root->fs_info->tree_root)) {
4130 btrfs_set_path_blocking(path);
4131 ret = btrfs_free_extent(trans, root, extent_start,
4132 extent_num_bytes, 0,
4133 btrfs_header_owner(leaf),
4134 ino, extent_offset, 0);
4135 BUG_ON(ret);
4136 }
4137
4138 if (found_type == BTRFS_INODE_ITEM_KEY)
4139 break;
4140
4141 if (path->slots[0] == 0 ||
4142 path->slots[0] != pending_del_slot) {
4143 if (pending_del_nr) {
4144 ret = btrfs_del_items(trans, root, path,
4145 pending_del_slot,
4146 pending_del_nr);
4147 if (ret) {
4148 btrfs_abort_transaction(trans,
4149 root, ret);
4150 goto error;
4151 }
4152 pending_del_nr = 0;
4153 }
4154 btrfs_release_path(path);
4155 goto search_again;
4156 } else {
4157 path->slots[0]--;
4158 }
4159 }
4160 out:
4161 if (pending_del_nr) {
4162 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4163 pending_del_nr);
4164 if (ret)
4165 btrfs_abort_transaction(trans, root, ret);
4166 }
4167 error:
4168 if (last_size != (u64)-1)
4169 btrfs_ordered_update_i_size(inode, last_size, NULL);
4170 btrfs_free_path(path);
4171 return err;
4172 }
4173
4174 /*
4175 * btrfs_truncate_page - read, zero a chunk and write a page
4176 * @inode - inode that we're zeroing
4177 * @from - the offset to start zeroing
4178 * @len - the length to zero, 0 to zero the entire range respective to the
4179 * offset
4180 * @front - zero up to the offset instead of from the offset on
4181 *
4182 * This will find the page for the "from" offset and cow the page and zero the
4183 * part we want to zero. This is used with truncate and hole punching.
4184 */
4185 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
4186 int front)
4187 {
4188 struct address_space *mapping = inode->i_mapping;
4189 struct btrfs_root *root = BTRFS_I(inode)->root;
4190 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4191 struct btrfs_ordered_extent *ordered;
4192 struct extent_state *cached_state = NULL;
4193 char *kaddr;
4194 u32 blocksize = root->sectorsize;
4195 pgoff_t index = from >> PAGE_CACHE_SHIFT;
4196 unsigned offset = from & (PAGE_CACHE_SIZE-1);
4197 struct page *page;
4198 gfp_t mask = btrfs_alloc_write_mask(mapping);
4199 int ret = 0;
4200 u64 page_start;
4201 u64 page_end;
4202
4203 if ((offset & (blocksize - 1)) == 0 &&
4204 (!len || ((len & (blocksize - 1)) == 0)))
4205 goto out;
4206 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
4207 if (ret)
4208 goto out;
4209
4210 again:
4211 page = find_or_create_page(mapping, index, mask);
4212 if (!page) {
4213 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4214 ret = -ENOMEM;
4215 goto out;
4216 }
4217
4218 page_start = page_offset(page);
4219 page_end = page_start + PAGE_CACHE_SIZE - 1;
4220
4221 if (!PageUptodate(page)) {
4222 ret = btrfs_readpage(NULL, page);
4223 lock_page(page);
4224 if (page->mapping != mapping) {
4225 unlock_page(page);
4226 page_cache_release(page);
4227 goto again;
4228 }
4229 if (!PageUptodate(page)) {
4230 ret = -EIO;
4231 goto out_unlock;
4232 }
4233 }
4234 wait_on_page_writeback(page);
4235
4236 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
4237 set_page_extent_mapped(page);
4238
4239 ordered = btrfs_lookup_ordered_extent(inode, page_start);
4240 if (ordered) {
4241 unlock_extent_cached(io_tree, page_start, page_end,
4242 &cached_state, GFP_NOFS);
4243 unlock_page(page);
4244 page_cache_release(page);
4245 btrfs_start_ordered_extent(inode, ordered, 1);
4246 btrfs_put_ordered_extent(ordered);
4247 goto again;
4248 }
4249
4250 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
4251 EXTENT_DIRTY | EXTENT_DELALLOC |
4252 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4253 0, 0, &cached_state, GFP_NOFS);
4254
4255 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
4256 &cached_state);
4257 if (ret) {
4258 unlock_extent_cached(io_tree, page_start, page_end,
4259 &cached_state, GFP_NOFS);
4260 goto out_unlock;
4261 }
4262
4263 if (offset != PAGE_CACHE_SIZE) {
4264 if (!len)
4265 len = PAGE_CACHE_SIZE - offset;
4266 kaddr = kmap(page);
4267 if (front)
4268 memset(kaddr, 0, offset);
4269 else
4270 memset(kaddr + offset, 0, len);
4271 flush_dcache_page(page);
4272 kunmap(page);
4273 }
4274 ClearPageChecked(page);
4275 set_page_dirty(page);
4276 unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
4277 GFP_NOFS);
4278
4279 out_unlock:
4280 if (ret)
4281 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4282 unlock_page(page);
4283 page_cache_release(page);
4284 out:
4285 return ret;
4286 }
4287
4288 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4289 u64 offset, u64 len)
4290 {
4291 struct btrfs_trans_handle *trans;
4292 int ret;
4293
4294 /*
4295 * Still need to make sure the inode looks like it's been updated so
4296 * that any holes get logged if we fsync.
4297 */
4298 if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) {
4299 BTRFS_I(inode)->last_trans = root->fs_info->generation;
4300 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4301 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4302 return 0;
4303 }
4304
4305 /*
4306 * 1 - for the one we're dropping
4307 * 1 - for the one we're adding
4308 * 1 - for updating the inode.
4309 */
4310 trans = btrfs_start_transaction(root, 3);
4311 if (IS_ERR(trans))
4312 return PTR_ERR(trans);
4313
4314 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4315 if (ret) {
4316 btrfs_abort_transaction(trans, root, ret);
4317 btrfs_end_transaction(trans, root);
4318 return ret;
4319 }
4320
4321 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
4322 0, 0, len, 0, len, 0, 0, 0);
4323 if (ret)
4324 btrfs_abort_transaction(trans, root, ret);
4325 else
4326 btrfs_update_inode(trans, root, inode);
4327 btrfs_end_transaction(trans, root);
4328 return ret;
4329 }
4330
4331 /*
4332 * This function puts in dummy file extents for the area we're creating a hole
4333 * for. So if we are truncating this file to a larger size we need to insert
4334 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4335 * the range between oldsize and size
4336 */
4337 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4338 {
4339 struct btrfs_root *root = BTRFS_I(inode)->root;
4340 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4341 struct extent_map *em = NULL;
4342 struct extent_state *cached_state = NULL;
4343 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4344 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4345 u64 block_end = ALIGN(size, root->sectorsize);
4346 u64 last_byte;
4347 u64 cur_offset;
4348 u64 hole_size;
4349 int err = 0;
4350
4351 /*
4352 * If our size started in the middle of a page we need to zero out the
4353 * rest of the page before we expand the i_size, otherwise we could
4354 * expose stale data.
4355 */
4356 err = btrfs_truncate_page(inode, oldsize, 0, 0);
4357 if (err)
4358 return err;
4359
4360 if (size <= hole_start)
4361 return 0;
4362
4363 while (1) {
4364 struct btrfs_ordered_extent *ordered;
4365
4366 lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
4367 &cached_state);
4368 ordered = btrfs_lookup_ordered_range(inode, hole_start,
4369 block_end - hole_start);
4370 if (!ordered)
4371 break;
4372 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4373 &cached_state, GFP_NOFS);
4374 btrfs_start_ordered_extent(inode, ordered, 1);
4375 btrfs_put_ordered_extent(ordered);
4376 }
4377
4378 cur_offset = hole_start;
4379 while (1) {
4380 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4381 block_end - cur_offset, 0);
4382 if (IS_ERR(em)) {
4383 err = PTR_ERR(em);
4384 em = NULL;
4385 break;
4386 }
4387 last_byte = min(extent_map_end(em), block_end);
4388 last_byte = ALIGN(last_byte , root->sectorsize);
4389 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4390 struct extent_map *hole_em;
4391 hole_size = last_byte - cur_offset;
4392
4393 err = maybe_insert_hole(root, inode, cur_offset,
4394 hole_size);
4395 if (err)
4396 break;
4397 btrfs_drop_extent_cache(inode, cur_offset,
4398 cur_offset + hole_size - 1, 0);
4399 hole_em = alloc_extent_map();
4400 if (!hole_em) {
4401 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4402 &BTRFS_I(inode)->runtime_flags);
4403 goto next;
4404 }
4405 hole_em->start = cur_offset;
4406 hole_em->len = hole_size;
4407 hole_em->orig_start = cur_offset;
4408
4409 hole_em->block_start = EXTENT_MAP_HOLE;
4410 hole_em->block_len = 0;
4411 hole_em->orig_block_len = 0;
4412 hole_em->ram_bytes = hole_size;
4413 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4414 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4415 hole_em->generation = root->fs_info->generation;
4416
4417 while (1) {
4418 write_lock(&em_tree->lock);
4419 err = add_extent_mapping(em_tree, hole_em, 1);
4420 write_unlock(&em_tree->lock);
4421 if (err != -EEXIST)
4422 break;
4423 btrfs_drop_extent_cache(inode, cur_offset,
4424 cur_offset +
4425 hole_size - 1, 0);
4426 }
4427 free_extent_map(hole_em);
4428 }
4429 next:
4430 free_extent_map(em);
4431 em = NULL;
4432 cur_offset = last_byte;
4433 if (cur_offset >= block_end)
4434 break;
4435 }
4436 free_extent_map(em);
4437 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4438 GFP_NOFS);
4439 return err;
4440 }
4441
4442 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4443 {
4444 struct btrfs_root *root = BTRFS_I(inode)->root;
4445 struct btrfs_trans_handle *trans;
4446 loff_t oldsize = i_size_read(inode);
4447 loff_t newsize = attr->ia_size;
4448 int mask = attr->ia_valid;
4449 int ret;
4450
4451 /*
4452 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4453 * special case where we need to update the times despite not having
4454 * these flags set. For all other operations the VFS set these flags
4455 * explicitly if it wants a timestamp update.
4456 */
4457 if (newsize != oldsize) {
4458 inode_inc_iversion(inode);
4459 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
4460 inode->i_ctime = inode->i_mtime =
4461 current_fs_time(inode->i_sb);
4462 }
4463
4464 if (newsize > oldsize) {
4465 truncate_pagecache(inode, newsize);
4466 ret = btrfs_cont_expand(inode, oldsize, newsize);
4467 if (ret)
4468 return ret;
4469
4470 trans = btrfs_start_transaction(root, 1);
4471 if (IS_ERR(trans))
4472 return PTR_ERR(trans);
4473
4474 i_size_write(inode, newsize);
4475 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4476 ret = btrfs_update_inode(trans, root, inode);
4477 btrfs_end_transaction(trans, root);
4478 } else {
4479
4480 /*
4481 * We're truncating a file that used to have good data down to
4482 * zero. Make sure it gets into the ordered flush list so that
4483 * any new writes get down to disk quickly.
4484 */
4485 if (newsize == 0)
4486 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
4487 &BTRFS_I(inode)->runtime_flags);
4488
4489 /*
4490 * 1 for the orphan item we're going to add
4491 * 1 for the orphan item deletion.
4492 */
4493 trans = btrfs_start_transaction(root, 2);
4494 if (IS_ERR(trans))
4495 return PTR_ERR(trans);
4496
4497 /*
4498 * We need to do this in case we fail at _any_ point during the
4499 * actual truncate. Once we do the truncate_setsize we could
4500 * invalidate pages which forces any outstanding ordered io to
4501 * be instantly completed which will give us extents that need
4502 * to be truncated. If we fail to get an orphan inode down we
4503 * could have left over extents that were never meant to live,
4504 * so we need to garuntee from this point on that everything
4505 * will be consistent.
4506 */
4507 ret = btrfs_orphan_add(trans, inode);
4508 btrfs_end_transaction(trans, root);
4509 if (ret)
4510 return ret;
4511
4512 /* we don't support swapfiles, so vmtruncate shouldn't fail */
4513 truncate_setsize(inode, newsize);
4514
4515 /* Disable nonlocked read DIO to avoid the end less truncate */
4516 btrfs_inode_block_unlocked_dio(inode);
4517 inode_dio_wait(inode);
4518 btrfs_inode_resume_unlocked_dio(inode);
4519
4520 ret = btrfs_truncate(inode);
4521 if (ret && inode->i_nlink) {
4522 int err;
4523
4524 /*
4525 * failed to truncate, disk_i_size is only adjusted down
4526 * as we remove extents, so it should represent the true
4527 * size of the inode, so reset the in memory size and
4528 * delete our orphan entry.
4529 */
4530 trans = btrfs_join_transaction(root);
4531 if (IS_ERR(trans)) {
4532 btrfs_orphan_del(NULL, inode);
4533 return ret;
4534 }
4535 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
4536 err = btrfs_orphan_del(trans, inode);
4537 if (err)
4538 btrfs_abort_transaction(trans, root, err);
4539 btrfs_end_transaction(trans, root);
4540 }
4541 }
4542
4543 return ret;
4544 }
4545
4546 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
4547 {
4548 struct inode *inode = dentry->d_inode;
4549 struct btrfs_root *root = BTRFS_I(inode)->root;
4550 int err;
4551
4552 if (btrfs_root_readonly(root))
4553 return -EROFS;
4554
4555 err = inode_change_ok(inode, attr);
4556 if (err)
4557 return err;
4558
4559 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
4560 err = btrfs_setsize(inode, attr);
4561 if (err)
4562 return err;
4563 }
4564
4565 if (attr->ia_valid) {
4566 setattr_copy(inode, attr);
4567 inode_inc_iversion(inode);
4568 err = btrfs_dirty_inode(inode);
4569
4570 if (!err && attr->ia_valid & ATTR_MODE)
4571 err = posix_acl_chmod(inode, inode->i_mode);
4572 }
4573
4574 return err;
4575 }
4576
4577 /*
4578 * While truncating the inode pages during eviction, we get the VFS calling
4579 * btrfs_invalidatepage() against each page of the inode. This is slow because
4580 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
4581 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
4582 * extent_state structures over and over, wasting lots of time.
4583 *
4584 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
4585 * those expensive operations on a per page basis and do only the ordered io
4586 * finishing, while we release here the extent_map and extent_state structures,
4587 * without the excessive merging and splitting.
4588 */
4589 static void evict_inode_truncate_pages(struct inode *inode)
4590 {
4591 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4592 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
4593 struct rb_node *node;
4594
4595 ASSERT(inode->i_state & I_FREEING);
4596 truncate_inode_pages(&inode->i_data, 0);
4597
4598 write_lock(&map_tree->lock);
4599 while (!RB_EMPTY_ROOT(&map_tree->map)) {
4600 struct extent_map *em;
4601
4602 node = rb_first(&map_tree->map);
4603 em = rb_entry(node, struct extent_map, rb_node);
4604 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
4605 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
4606 remove_extent_mapping(map_tree, em);
4607 free_extent_map(em);
4608 }
4609 write_unlock(&map_tree->lock);
4610
4611 spin_lock(&io_tree->lock);
4612 while (!RB_EMPTY_ROOT(&io_tree->state)) {
4613 struct extent_state *state;
4614 struct extent_state *cached_state = NULL;
4615
4616 node = rb_first(&io_tree->state);
4617 state = rb_entry(node, struct extent_state, rb_node);
4618 atomic_inc(&state->refs);
4619 spin_unlock(&io_tree->lock);
4620
4621 lock_extent_bits(io_tree, state->start, state->end,
4622 0, &cached_state);
4623 clear_extent_bit(io_tree, state->start, state->end,
4624 EXTENT_LOCKED | EXTENT_DIRTY |
4625 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
4626 EXTENT_DEFRAG, 1, 1,
4627 &cached_state, GFP_NOFS);
4628 free_extent_state(state);
4629
4630 spin_lock(&io_tree->lock);
4631 }
4632 spin_unlock(&io_tree->lock);
4633 }
4634
4635 void btrfs_evict_inode(struct inode *inode)
4636 {
4637 struct btrfs_trans_handle *trans;
4638 struct btrfs_root *root = BTRFS_I(inode)->root;
4639 struct btrfs_block_rsv *rsv, *global_rsv;
4640 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
4641 int ret;
4642
4643 trace_btrfs_inode_evict(inode);
4644
4645 evict_inode_truncate_pages(inode);
4646
4647 if (inode->i_nlink &&
4648 ((btrfs_root_refs(&root->root_item) != 0 &&
4649 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
4650 btrfs_is_free_space_inode(inode)))
4651 goto no_delete;
4652
4653 if (is_bad_inode(inode)) {
4654 btrfs_orphan_del(NULL, inode);
4655 goto no_delete;
4656 }
4657 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
4658 btrfs_wait_ordered_range(inode, 0, (u64)-1);
4659
4660 if (root->fs_info->log_root_recovering) {
4661 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
4662 &BTRFS_I(inode)->runtime_flags));
4663 goto no_delete;
4664 }
4665
4666 if (inode->i_nlink > 0) {
4667 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
4668 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
4669 goto no_delete;
4670 }
4671
4672 ret = btrfs_commit_inode_delayed_inode(inode);
4673 if (ret) {
4674 btrfs_orphan_del(NULL, inode);
4675 goto no_delete;
4676 }
4677
4678 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
4679 if (!rsv) {
4680 btrfs_orphan_del(NULL, inode);
4681 goto no_delete;
4682 }
4683 rsv->size = min_size;
4684 rsv->failfast = 1;
4685 global_rsv = &root->fs_info->global_block_rsv;
4686
4687 btrfs_i_size_write(inode, 0);
4688
4689 /*
4690 * This is a bit simpler than btrfs_truncate since we've already
4691 * reserved our space for our orphan item in the unlink, so we just
4692 * need to reserve some slack space in case we add bytes and update
4693 * inode item when doing the truncate.
4694 */
4695 while (1) {
4696 ret = btrfs_block_rsv_refill(root, rsv, min_size,
4697 BTRFS_RESERVE_FLUSH_LIMIT);
4698
4699 /*
4700 * Try and steal from the global reserve since we will
4701 * likely not use this space anyway, we want to try as
4702 * hard as possible to get this to work.
4703 */
4704 if (ret)
4705 ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size);
4706
4707 if (ret) {
4708 btrfs_warn(root->fs_info,
4709 "Could not get space for a delete, will truncate on mount %d",
4710 ret);
4711 btrfs_orphan_del(NULL, inode);
4712 btrfs_free_block_rsv(root, rsv);
4713 goto no_delete;
4714 }
4715
4716 trans = btrfs_join_transaction(root);
4717 if (IS_ERR(trans)) {
4718 btrfs_orphan_del(NULL, inode);
4719 btrfs_free_block_rsv(root, rsv);
4720 goto no_delete;
4721 }
4722
4723 trans->block_rsv = rsv;
4724
4725 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
4726 if (ret != -ENOSPC)
4727 break;
4728
4729 trans->block_rsv = &root->fs_info->trans_block_rsv;
4730 btrfs_end_transaction(trans, root);
4731 trans = NULL;
4732 btrfs_btree_balance_dirty(root);
4733 }
4734
4735 btrfs_free_block_rsv(root, rsv);
4736
4737 /*
4738 * Errors here aren't a big deal, it just means we leave orphan items
4739 * in the tree. They will be cleaned up on the next mount.
4740 */
4741 if (ret == 0) {
4742 trans->block_rsv = root->orphan_block_rsv;
4743 btrfs_orphan_del(trans, inode);
4744 } else {
4745 btrfs_orphan_del(NULL, inode);
4746 }
4747
4748 trans->block_rsv = &root->fs_info->trans_block_rsv;
4749 if (!(root == root->fs_info->tree_root ||
4750 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
4751 btrfs_return_ino(root, btrfs_ino(inode));
4752
4753 btrfs_end_transaction(trans, root);
4754 btrfs_btree_balance_dirty(root);
4755 no_delete:
4756 btrfs_remove_delayed_node(inode);
4757 clear_inode(inode);
4758 return;
4759 }
4760
4761 /*
4762 * this returns the key found in the dir entry in the location pointer.
4763 * If no dir entries were found, location->objectid is 0.
4764 */
4765 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
4766 struct btrfs_key *location)
4767 {
4768 const char *name = dentry->d_name.name;
4769 int namelen = dentry->d_name.len;
4770 struct btrfs_dir_item *di;
4771 struct btrfs_path *path;
4772 struct btrfs_root *root = BTRFS_I(dir)->root;
4773 int ret = 0;
4774
4775 path = btrfs_alloc_path();
4776 if (!path)
4777 return -ENOMEM;
4778
4779 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
4780 namelen, 0);
4781 if (IS_ERR(di))
4782 ret = PTR_ERR(di);
4783
4784 if (IS_ERR_OR_NULL(di))
4785 goto out_err;
4786
4787 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
4788 out:
4789 btrfs_free_path(path);
4790 return ret;
4791 out_err:
4792 location->objectid = 0;
4793 goto out;
4794 }
4795
4796 /*
4797 * when we hit a tree root in a directory, the btrfs part of the inode
4798 * needs to be changed to reflect the root directory of the tree root. This
4799 * is kind of like crossing a mount point.
4800 */
4801 static int fixup_tree_root_location(struct btrfs_root *root,
4802 struct inode *dir,
4803 struct dentry *dentry,
4804 struct btrfs_key *location,
4805 struct btrfs_root **sub_root)
4806 {
4807 struct btrfs_path *path;
4808 struct btrfs_root *new_root;
4809 struct btrfs_root_ref *ref;
4810 struct extent_buffer *leaf;
4811 int ret;
4812 int err = 0;
4813
4814 path = btrfs_alloc_path();
4815 if (!path) {
4816 err = -ENOMEM;
4817 goto out;
4818 }
4819
4820 err = -ENOENT;
4821 ret = btrfs_find_item(root->fs_info->tree_root, path,
4822 BTRFS_I(dir)->root->root_key.objectid,
4823 location->objectid, BTRFS_ROOT_REF_KEY, NULL);
4824 if (ret) {
4825 if (ret < 0)
4826 err = ret;
4827 goto out;
4828 }
4829
4830 leaf = path->nodes[0];
4831 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
4832 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
4833 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
4834 goto out;
4835
4836 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
4837 (unsigned long)(ref + 1),
4838 dentry->d_name.len);
4839 if (ret)
4840 goto out;
4841
4842 btrfs_release_path(path);
4843
4844 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
4845 if (IS_ERR(new_root)) {
4846 err = PTR_ERR(new_root);
4847 goto out;
4848 }
4849
4850 *sub_root = new_root;
4851 location->objectid = btrfs_root_dirid(&new_root->root_item);
4852 location->type = BTRFS_INODE_ITEM_KEY;
4853 location->offset = 0;
4854 err = 0;
4855 out:
4856 btrfs_free_path(path);
4857 return err;
4858 }
4859
4860 static void inode_tree_add(struct inode *inode)
4861 {
4862 struct btrfs_root *root = BTRFS_I(inode)->root;
4863 struct btrfs_inode *entry;
4864 struct rb_node **p;
4865 struct rb_node *parent;
4866 struct rb_node *new = &BTRFS_I(inode)->rb_node;
4867 u64 ino = btrfs_ino(inode);
4868
4869 if (inode_unhashed(inode))
4870 return;
4871 parent = NULL;
4872 spin_lock(&root->inode_lock);
4873 p = &root->inode_tree.rb_node;
4874 while (*p) {
4875 parent = *p;
4876 entry = rb_entry(parent, struct btrfs_inode, rb_node);
4877
4878 if (ino < btrfs_ino(&entry->vfs_inode))
4879 p = &parent->rb_left;
4880 else if (ino > btrfs_ino(&entry->vfs_inode))
4881 p = &parent->rb_right;
4882 else {
4883 WARN_ON(!(entry->vfs_inode.i_state &
4884 (I_WILL_FREE | I_FREEING)));
4885 rb_replace_node(parent, new, &root->inode_tree);
4886 RB_CLEAR_NODE(parent);
4887 spin_unlock(&root->inode_lock);
4888 return;
4889 }
4890 }
4891 rb_link_node(new, parent, p);
4892 rb_insert_color(new, &root->inode_tree);
4893 spin_unlock(&root->inode_lock);
4894 }
4895
4896 static void inode_tree_del(struct inode *inode)
4897 {
4898 struct btrfs_root *root = BTRFS_I(inode)->root;
4899 int empty = 0;
4900
4901 spin_lock(&root->inode_lock);
4902 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
4903 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
4904 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
4905 empty = RB_EMPTY_ROOT(&root->inode_tree);
4906 }
4907 spin_unlock(&root->inode_lock);
4908
4909 if (empty && btrfs_root_refs(&root->root_item) == 0) {
4910 synchronize_srcu(&root->fs_info->subvol_srcu);
4911 spin_lock(&root->inode_lock);
4912 empty = RB_EMPTY_ROOT(&root->inode_tree);
4913 spin_unlock(&root->inode_lock);
4914 if (empty)
4915 btrfs_add_dead_root(root);
4916 }
4917 }
4918
4919 void btrfs_invalidate_inodes(struct btrfs_root *root)
4920 {
4921 struct rb_node *node;
4922 struct rb_node *prev;
4923 struct btrfs_inode *entry;
4924 struct inode *inode;
4925 u64 objectid = 0;
4926
4927 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
4928
4929 spin_lock(&root->inode_lock);
4930 again:
4931 node = root->inode_tree.rb_node;
4932 prev = NULL;
4933 while (node) {
4934 prev = node;
4935 entry = rb_entry(node, struct btrfs_inode, rb_node);
4936
4937 if (objectid < btrfs_ino(&entry->vfs_inode))
4938 node = node->rb_left;
4939 else if (objectid > btrfs_ino(&entry->vfs_inode))
4940 node = node->rb_right;
4941 else
4942 break;
4943 }
4944 if (!node) {
4945 while (prev) {
4946 entry = rb_entry(prev, struct btrfs_inode, rb_node);
4947 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
4948 node = prev;
4949 break;
4950 }
4951 prev = rb_next(prev);
4952 }
4953 }
4954 while (node) {
4955 entry = rb_entry(node, struct btrfs_inode, rb_node);
4956 objectid = btrfs_ino(&entry->vfs_inode) + 1;
4957 inode = igrab(&entry->vfs_inode);
4958 if (inode) {
4959 spin_unlock(&root->inode_lock);
4960 if (atomic_read(&inode->i_count) > 1)
4961 d_prune_aliases(inode);
4962 /*
4963 * btrfs_drop_inode will have it removed from
4964 * the inode cache when its usage count
4965 * hits zero.
4966 */
4967 iput(inode);
4968 cond_resched();
4969 spin_lock(&root->inode_lock);
4970 goto again;
4971 }
4972
4973 if (cond_resched_lock(&root->inode_lock))
4974 goto again;
4975
4976 node = rb_next(node);
4977 }
4978 spin_unlock(&root->inode_lock);
4979 }
4980
4981 static int btrfs_init_locked_inode(struct inode *inode, void *p)
4982 {
4983 struct btrfs_iget_args *args = p;
4984 inode->i_ino = args->location->objectid;
4985 memcpy(&BTRFS_I(inode)->location, args->location,
4986 sizeof(*args->location));
4987 BTRFS_I(inode)->root = args->root;
4988 return 0;
4989 }
4990
4991 static int btrfs_find_actor(struct inode *inode, void *opaque)
4992 {
4993 struct btrfs_iget_args *args = opaque;
4994 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
4995 args->root == BTRFS_I(inode)->root;
4996 }
4997
4998 static struct inode *btrfs_iget_locked(struct super_block *s,
4999 struct btrfs_key *location,
5000 struct btrfs_root *root)
5001 {
5002 struct inode *inode;
5003 struct btrfs_iget_args args;
5004 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5005
5006 args.location = location;
5007 args.root = root;
5008
5009 inode = iget5_locked(s, hashval, btrfs_find_actor,
5010 btrfs_init_locked_inode,
5011 (void *)&args);
5012 return inode;
5013 }
5014
5015 /* Get an inode object given its location and corresponding root.
5016 * Returns in *is_new if the inode was read from disk
5017 */
5018 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5019 struct btrfs_root *root, int *new)
5020 {
5021 struct inode *inode;
5022
5023 inode = btrfs_iget_locked(s, location, root);
5024 if (!inode)
5025 return ERR_PTR(-ENOMEM);
5026
5027 if (inode->i_state & I_NEW) {
5028 btrfs_read_locked_inode(inode);
5029 if (!is_bad_inode(inode)) {
5030 inode_tree_add(inode);
5031 unlock_new_inode(inode);
5032 if (new)
5033 *new = 1;
5034 } else {
5035 unlock_new_inode(inode);
5036 iput(inode);
5037 inode = ERR_PTR(-ESTALE);
5038 }
5039 }
5040
5041 return inode;
5042 }
5043
5044 static struct inode *new_simple_dir(struct super_block *s,
5045 struct btrfs_key *key,
5046 struct btrfs_root *root)
5047 {
5048 struct inode *inode = new_inode(s);
5049
5050 if (!inode)
5051 return ERR_PTR(-ENOMEM);
5052
5053 BTRFS_I(inode)->root = root;
5054 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5055 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5056
5057 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5058 inode->i_op = &btrfs_dir_ro_inode_operations;
5059 inode->i_fop = &simple_dir_operations;
5060 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5061 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
5062
5063 return inode;
5064 }
5065
5066 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5067 {
5068 struct inode *inode;
5069 struct btrfs_root *root = BTRFS_I(dir)->root;
5070 struct btrfs_root *sub_root = root;
5071 struct btrfs_key location;
5072 int index;
5073 int ret = 0;
5074
5075 if (dentry->d_name.len > BTRFS_NAME_LEN)
5076 return ERR_PTR(-ENAMETOOLONG);
5077
5078 ret = btrfs_inode_by_name(dir, dentry, &location);
5079 if (ret < 0)
5080 return ERR_PTR(ret);
5081
5082 if (location.objectid == 0)
5083 return ERR_PTR(-ENOENT);
5084
5085 if (location.type == BTRFS_INODE_ITEM_KEY) {
5086 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5087 return inode;
5088 }
5089
5090 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5091
5092 index = srcu_read_lock(&root->fs_info->subvol_srcu);
5093 ret = fixup_tree_root_location(root, dir, dentry,
5094 &location, &sub_root);
5095 if (ret < 0) {
5096 if (ret != -ENOENT)
5097 inode = ERR_PTR(ret);
5098 else
5099 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5100 } else {
5101 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5102 }
5103 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
5104
5105 if (!IS_ERR(inode) && root != sub_root) {
5106 down_read(&root->fs_info->cleanup_work_sem);
5107 if (!(inode->i_sb->s_flags & MS_RDONLY))
5108 ret = btrfs_orphan_cleanup(sub_root);
5109 up_read(&root->fs_info->cleanup_work_sem);
5110 if (ret) {
5111 iput(inode);
5112 inode = ERR_PTR(ret);
5113 }
5114 }
5115
5116 return inode;
5117 }
5118
5119 static int btrfs_dentry_delete(const struct dentry *dentry)
5120 {
5121 struct btrfs_root *root;
5122 struct inode *inode = dentry->d_inode;
5123
5124 if (!inode && !IS_ROOT(dentry))
5125 inode = dentry->d_parent->d_inode;
5126
5127 if (inode) {
5128 root = BTRFS_I(inode)->root;
5129 if (btrfs_root_refs(&root->root_item) == 0)
5130 return 1;
5131
5132 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5133 return 1;
5134 }
5135 return 0;
5136 }
5137
5138 static void btrfs_dentry_release(struct dentry *dentry)
5139 {
5140 if (dentry->d_fsdata)
5141 kfree(dentry->d_fsdata);
5142 }
5143
5144 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5145 unsigned int flags)
5146 {
5147 struct inode *inode;
5148
5149 inode = btrfs_lookup_dentry(dir, dentry);
5150 if (IS_ERR(inode)) {
5151 if (PTR_ERR(inode) == -ENOENT)
5152 inode = NULL;
5153 else
5154 return ERR_CAST(inode);
5155 }
5156
5157 return d_materialise_unique(dentry, inode);
5158 }
5159
5160 unsigned char btrfs_filetype_table[] = {
5161 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5162 };
5163
5164 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5165 {
5166 struct inode *inode = file_inode(file);
5167 struct btrfs_root *root = BTRFS_I(inode)->root;
5168 struct btrfs_item *item;
5169 struct btrfs_dir_item *di;
5170 struct btrfs_key key;
5171 struct btrfs_key found_key;
5172 struct btrfs_path *path;
5173 struct list_head ins_list;
5174 struct list_head del_list;
5175 int ret;
5176 struct extent_buffer *leaf;
5177 int slot;
5178 unsigned char d_type;
5179 int over = 0;
5180 u32 di_cur;
5181 u32 di_total;
5182 u32 di_len;
5183 int key_type = BTRFS_DIR_INDEX_KEY;
5184 char tmp_name[32];
5185 char *name_ptr;
5186 int name_len;
5187 int is_curr = 0; /* ctx->pos points to the current index? */
5188
5189 /* FIXME, use a real flag for deciding about the key type */
5190 if (root->fs_info->tree_root == root)
5191 key_type = BTRFS_DIR_ITEM_KEY;
5192
5193 if (!dir_emit_dots(file, ctx))
5194 return 0;
5195
5196 path = btrfs_alloc_path();
5197 if (!path)
5198 return -ENOMEM;
5199
5200 path->reada = 1;
5201
5202 if (key_type == BTRFS_DIR_INDEX_KEY) {
5203 INIT_LIST_HEAD(&ins_list);
5204 INIT_LIST_HEAD(&del_list);
5205 btrfs_get_delayed_items(inode, &ins_list, &del_list);
5206 }
5207
5208 btrfs_set_key_type(&key, key_type);
5209 key.offset = ctx->pos;
5210 key.objectid = btrfs_ino(inode);
5211
5212 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5213 if (ret < 0)
5214 goto err;
5215
5216 while (1) {
5217 leaf = path->nodes[0];
5218 slot = path->slots[0];
5219 if (slot >= btrfs_header_nritems(leaf)) {
5220 ret = btrfs_next_leaf(root, path);
5221 if (ret < 0)
5222 goto err;
5223 else if (ret > 0)
5224 break;
5225 continue;
5226 }
5227
5228 item = btrfs_item_nr(slot);
5229 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5230
5231 if (found_key.objectid != key.objectid)
5232 break;
5233 if (btrfs_key_type(&found_key) != key_type)
5234 break;
5235 if (found_key.offset < ctx->pos)
5236 goto next;
5237 if (key_type == BTRFS_DIR_INDEX_KEY &&
5238 btrfs_should_delete_dir_index(&del_list,
5239 found_key.offset))
5240 goto next;
5241
5242 ctx->pos = found_key.offset;
5243 is_curr = 1;
5244
5245 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5246 di_cur = 0;
5247 di_total = btrfs_item_size(leaf, item);
5248
5249 while (di_cur < di_total) {
5250 struct btrfs_key location;
5251
5252 if (verify_dir_item(root, leaf, di))
5253 break;
5254
5255 name_len = btrfs_dir_name_len(leaf, di);
5256 if (name_len <= sizeof(tmp_name)) {
5257 name_ptr = tmp_name;
5258 } else {
5259 name_ptr = kmalloc(name_len, GFP_NOFS);
5260 if (!name_ptr) {
5261 ret = -ENOMEM;
5262 goto err;
5263 }
5264 }
5265 read_extent_buffer(leaf, name_ptr,
5266 (unsigned long)(di + 1), name_len);
5267
5268 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5269 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5270
5271
5272 /* is this a reference to our own snapshot? If so
5273 * skip it.
5274 *
5275 * In contrast to old kernels, we insert the snapshot's
5276 * dir item and dir index after it has been created, so
5277 * we won't find a reference to our own snapshot. We
5278 * still keep the following code for backward
5279 * compatibility.
5280 */
5281 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5282 location.objectid == root->root_key.objectid) {
5283 over = 0;
5284 goto skip;
5285 }
5286 over = !dir_emit(ctx, name_ptr, name_len,
5287 location.objectid, d_type);
5288
5289 skip:
5290 if (name_ptr != tmp_name)
5291 kfree(name_ptr);
5292
5293 if (over)
5294 goto nopos;
5295 di_len = btrfs_dir_name_len(leaf, di) +
5296 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5297 di_cur += di_len;
5298 di = (struct btrfs_dir_item *)((char *)di + di_len);
5299 }
5300 next:
5301 path->slots[0]++;
5302 }
5303
5304 if (key_type == BTRFS_DIR_INDEX_KEY) {
5305 if (is_curr)
5306 ctx->pos++;
5307 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
5308 if (ret)
5309 goto nopos;
5310 }
5311
5312 /* Reached end of directory/root. Bump pos past the last item. */
5313 ctx->pos++;
5314
5315 /*
5316 * Stop new entries from being returned after we return the last
5317 * entry.
5318 *
5319 * New directory entries are assigned a strictly increasing
5320 * offset. This means that new entries created during readdir
5321 * are *guaranteed* to be seen in the future by that readdir.
5322 * This has broken buggy programs which operate on names as
5323 * they're returned by readdir. Until we re-use freed offsets
5324 * we have this hack to stop new entries from being returned
5325 * under the assumption that they'll never reach this huge
5326 * offset.
5327 *
5328 * This is being careful not to overflow 32bit loff_t unless the
5329 * last entry requires it because doing so has broken 32bit apps
5330 * in the past.
5331 */
5332 if (key_type == BTRFS_DIR_INDEX_KEY) {
5333 if (ctx->pos >= INT_MAX)
5334 ctx->pos = LLONG_MAX;
5335 else
5336 ctx->pos = INT_MAX;
5337 }
5338 nopos:
5339 ret = 0;
5340 err:
5341 if (key_type == BTRFS_DIR_INDEX_KEY)
5342 btrfs_put_delayed_items(&ins_list, &del_list);
5343 btrfs_free_path(path);
5344 return ret;
5345 }
5346
5347 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5348 {
5349 struct btrfs_root *root = BTRFS_I(inode)->root;
5350 struct btrfs_trans_handle *trans;
5351 int ret = 0;
5352 bool nolock = false;
5353
5354 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5355 return 0;
5356
5357 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5358 nolock = true;
5359
5360 if (wbc->sync_mode == WB_SYNC_ALL) {
5361 if (nolock)
5362 trans = btrfs_join_transaction_nolock(root);
5363 else
5364 trans = btrfs_join_transaction(root);
5365 if (IS_ERR(trans))
5366 return PTR_ERR(trans);
5367 ret = btrfs_commit_transaction(trans, root);
5368 }
5369 return ret;
5370 }
5371
5372 /*
5373 * This is somewhat expensive, updating the tree every time the
5374 * inode changes. But, it is most likely to find the inode in cache.
5375 * FIXME, needs more benchmarking...there are no reasons other than performance
5376 * to keep or drop this code.
5377 */
5378 static int btrfs_dirty_inode(struct inode *inode)
5379 {
5380 struct btrfs_root *root = BTRFS_I(inode)->root;
5381 struct btrfs_trans_handle *trans;
5382 int ret;
5383
5384 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5385 return 0;
5386
5387 trans = btrfs_join_transaction(root);
5388 if (IS_ERR(trans))
5389 return PTR_ERR(trans);
5390
5391 ret = btrfs_update_inode(trans, root, inode);
5392 if (ret && ret == -ENOSPC) {
5393 /* whoops, lets try again with the full transaction */
5394 btrfs_end_transaction(trans, root);
5395 trans = btrfs_start_transaction(root, 1);
5396 if (IS_ERR(trans))
5397 return PTR_ERR(trans);
5398
5399 ret = btrfs_update_inode(trans, root, inode);
5400 }
5401 btrfs_end_transaction(trans, root);
5402 if (BTRFS_I(inode)->delayed_node)
5403 btrfs_balance_delayed_items(root);
5404
5405 return ret;
5406 }
5407
5408 /*
5409 * This is a copy of file_update_time. We need this so we can return error on
5410 * ENOSPC for updating the inode in the case of file write and mmap writes.
5411 */
5412 static int btrfs_update_time(struct inode *inode, struct timespec *now,
5413 int flags)
5414 {
5415 struct btrfs_root *root = BTRFS_I(inode)->root;
5416
5417 if (btrfs_root_readonly(root))
5418 return -EROFS;
5419
5420 if (flags & S_VERSION)
5421 inode_inc_iversion(inode);
5422 if (flags & S_CTIME)
5423 inode->i_ctime = *now;
5424 if (flags & S_MTIME)
5425 inode->i_mtime = *now;
5426 if (flags & S_ATIME)
5427 inode->i_atime = *now;
5428 return btrfs_dirty_inode(inode);
5429 }
5430
5431 /*
5432 * find the highest existing sequence number in a directory
5433 * and then set the in-memory index_cnt variable to reflect
5434 * free sequence numbers
5435 */
5436 static int btrfs_set_inode_index_count(struct inode *inode)
5437 {
5438 struct btrfs_root *root = BTRFS_I(inode)->root;
5439 struct btrfs_key key, found_key;
5440 struct btrfs_path *path;
5441 struct extent_buffer *leaf;
5442 int ret;
5443
5444 key.objectid = btrfs_ino(inode);
5445 btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
5446 key.offset = (u64)-1;
5447
5448 path = btrfs_alloc_path();
5449 if (!path)
5450 return -ENOMEM;
5451
5452 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5453 if (ret < 0)
5454 goto out;
5455 /* FIXME: we should be able to handle this */
5456 if (ret == 0)
5457 goto out;
5458 ret = 0;
5459
5460 /*
5461 * MAGIC NUMBER EXPLANATION:
5462 * since we search a directory based on f_pos we have to start at 2
5463 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
5464 * else has to start at 2
5465 */
5466 if (path->slots[0] == 0) {
5467 BTRFS_I(inode)->index_cnt = 2;
5468 goto out;
5469 }
5470
5471 path->slots[0]--;
5472
5473 leaf = path->nodes[0];
5474 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5475
5476 if (found_key.objectid != btrfs_ino(inode) ||
5477 btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) {
5478 BTRFS_I(inode)->index_cnt = 2;
5479 goto out;
5480 }
5481
5482 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
5483 out:
5484 btrfs_free_path(path);
5485 return ret;
5486 }
5487
5488 /*
5489 * helper to find a free sequence number in a given directory. This current
5490 * code is very simple, later versions will do smarter things in the btree
5491 */
5492 int btrfs_set_inode_index(struct inode *dir, u64 *index)
5493 {
5494 int ret = 0;
5495
5496 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
5497 ret = btrfs_inode_delayed_dir_index_count(dir);
5498 if (ret) {
5499 ret = btrfs_set_inode_index_count(dir);
5500 if (ret)
5501 return ret;
5502 }
5503 }
5504
5505 *index = BTRFS_I(dir)->index_cnt;
5506 BTRFS_I(dir)->index_cnt++;
5507
5508 return ret;
5509 }
5510
5511 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
5512 struct btrfs_root *root,
5513 struct inode *dir,
5514 const char *name, int name_len,
5515 u64 ref_objectid, u64 objectid,
5516 umode_t mode, u64 *index)
5517 {
5518 struct inode *inode;
5519 struct btrfs_inode_item *inode_item;
5520 struct btrfs_key *location;
5521 struct btrfs_path *path;
5522 struct btrfs_inode_ref *ref;
5523 struct btrfs_key key[2];
5524 u32 sizes[2];
5525 unsigned long ptr;
5526 int ret;
5527
5528 path = btrfs_alloc_path();
5529 if (!path)
5530 return ERR_PTR(-ENOMEM);
5531
5532 inode = new_inode(root->fs_info->sb);
5533 if (!inode) {
5534 btrfs_free_path(path);
5535 return ERR_PTR(-ENOMEM);
5536 }
5537
5538 /*
5539 * we have to initialize this early, so we can reclaim the inode
5540 * number if we fail afterwards in this function.
5541 */
5542 inode->i_ino = objectid;
5543
5544 if (dir) {
5545 trace_btrfs_inode_request(dir);
5546
5547 ret = btrfs_set_inode_index(dir, index);
5548 if (ret) {
5549 btrfs_free_path(path);
5550 iput(inode);
5551 return ERR_PTR(ret);
5552 }
5553 }
5554 /*
5555 * index_cnt is ignored for everything but a dir,
5556 * btrfs_get_inode_index_count has an explanation for the magic
5557 * number
5558 */
5559 BTRFS_I(inode)->index_cnt = 2;
5560 BTRFS_I(inode)->dir_index = *index;
5561 BTRFS_I(inode)->root = root;
5562 BTRFS_I(inode)->generation = trans->transid;
5563 inode->i_generation = BTRFS_I(inode)->generation;
5564
5565 /*
5566 * We could have gotten an inode number from somebody who was fsynced
5567 * and then removed in this same transaction, so let's just set full
5568 * sync since it will be a full sync anyway and this will blow away the
5569 * old info in the log.
5570 */
5571 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
5572
5573 key[0].objectid = objectid;
5574 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
5575 key[0].offset = 0;
5576
5577 /*
5578 * Start new inodes with an inode_ref. This is slightly more
5579 * efficient for small numbers of hard links since they will
5580 * be packed into one item. Extended refs will kick in if we
5581 * add more hard links than can fit in the ref item.
5582 */
5583 key[1].objectid = objectid;
5584 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
5585 key[1].offset = ref_objectid;
5586
5587 sizes[0] = sizeof(struct btrfs_inode_item);
5588 sizes[1] = name_len + sizeof(*ref);
5589
5590 path->leave_spinning = 1;
5591 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
5592 if (ret != 0)
5593 goto fail;
5594
5595 inode_init_owner(inode, dir, mode);
5596 inode_set_bytes(inode, 0);
5597 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
5598 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
5599 struct btrfs_inode_item);
5600 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
5601 sizeof(*inode_item));
5602 fill_inode_item(trans, path->nodes[0], inode_item, inode);
5603
5604 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
5605 struct btrfs_inode_ref);
5606 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
5607 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
5608 ptr = (unsigned long)(ref + 1);
5609 write_extent_buffer(path->nodes[0], name, ptr, name_len);
5610
5611 btrfs_mark_buffer_dirty(path->nodes[0]);
5612 btrfs_free_path(path);
5613
5614 location = &BTRFS_I(inode)->location;
5615 location->objectid = objectid;
5616 location->offset = 0;
5617 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
5618
5619 btrfs_inherit_iflags(inode, dir);
5620
5621 if (S_ISREG(mode)) {
5622 if (btrfs_test_opt(root, NODATASUM))
5623 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
5624 if (btrfs_test_opt(root, NODATACOW))
5625 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
5626 BTRFS_INODE_NODATASUM;
5627 }
5628
5629 btrfs_insert_inode_hash(inode);
5630 inode_tree_add(inode);
5631
5632 trace_btrfs_inode_new(inode);
5633 btrfs_set_inode_last_trans(trans, inode);
5634
5635 btrfs_update_root_times(trans, root);
5636
5637 ret = btrfs_inode_inherit_props(trans, inode, dir);
5638 if (ret)
5639 btrfs_err(root->fs_info,
5640 "error inheriting props for ino %llu (root %llu): %d",
5641 btrfs_ino(inode), root->root_key.objectid, ret);
5642
5643 return inode;
5644 fail:
5645 if (dir)
5646 BTRFS_I(dir)->index_cnt--;
5647 btrfs_free_path(path);
5648 iput(inode);
5649 return ERR_PTR(ret);
5650 }
5651
5652 static inline u8 btrfs_inode_type(struct inode *inode)
5653 {
5654 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
5655 }
5656
5657 /*
5658 * utility function to add 'inode' into 'parent_inode' with
5659 * a give name and a given sequence number.
5660 * if 'add_backref' is true, also insert a backref from the
5661 * inode to the parent directory.
5662 */
5663 int btrfs_add_link(struct btrfs_trans_handle *trans,
5664 struct inode *parent_inode, struct inode *inode,
5665 const char *name, int name_len, int add_backref, u64 index)
5666 {
5667 int ret = 0;
5668 struct btrfs_key key;
5669 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
5670 u64 ino = btrfs_ino(inode);
5671 u64 parent_ino = btrfs_ino(parent_inode);
5672
5673 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5674 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
5675 } else {
5676 key.objectid = ino;
5677 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
5678 key.offset = 0;
5679 }
5680
5681 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5682 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
5683 key.objectid, root->root_key.objectid,
5684 parent_ino, index, name, name_len);
5685 } else if (add_backref) {
5686 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
5687 parent_ino, index);
5688 }
5689
5690 /* Nothing to clean up yet */
5691 if (ret)
5692 return ret;
5693
5694 ret = btrfs_insert_dir_item(trans, root, name, name_len,
5695 parent_inode, &key,
5696 btrfs_inode_type(inode), index);
5697 if (ret == -EEXIST || ret == -EOVERFLOW)
5698 goto fail_dir_item;
5699 else if (ret) {
5700 btrfs_abort_transaction(trans, root, ret);
5701 return ret;
5702 }
5703
5704 btrfs_i_size_write(parent_inode, parent_inode->i_size +
5705 name_len * 2);
5706 inode_inc_iversion(parent_inode);
5707 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
5708 ret = btrfs_update_inode(trans, root, parent_inode);
5709 if (ret)
5710 btrfs_abort_transaction(trans, root, ret);
5711 return ret;
5712
5713 fail_dir_item:
5714 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5715 u64 local_index;
5716 int err;
5717 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
5718 key.objectid, root->root_key.objectid,
5719 parent_ino, &local_index, name, name_len);
5720
5721 } else if (add_backref) {
5722 u64 local_index;
5723 int err;
5724
5725 err = btrfs_del_inode_ref(trans, root, name, name_len,
5726 ino, parent_ino, &local_index);
5727 }
5728 return ret;
5729 }
5730
5731 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
5732 struct inode *dir, struct dentry *dentry,
5733 struct inode *inode, int backref, u64 index)
5734 {
5735 int err = btrfs_add_link(trans, dir, inode,
5736 dentry->d_name.name, dentry->d_name.len,
5737 backref, index);
5738 if (err > 0)
5739 err = -EEXIST;
5740 return err;
5741 }
5742
5743 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
5744 umode_t mode, dev_t rdev)
5745 {
5746 struct btrfs_trans_handle *trans;
5747 struct btrfs_root *root = BTRFS_I(dir)->root;
5748 struct inode *inode = NULL;
5749 int err;
5750 int drop_inode = 0;
5751 u64 objectid;
5752 u64 index = 0;
5753
5754 if (!new_valid_dev(rdev))
5755 return -EINVAL;
5756
5757 /*
5758 * 2 for inode item and ref
5759 * 2 for dir items
5760 * 1 for xattr if selinux is on
5761 */
5762 trans = btrfs_start_transaction(root, 5);
5763 if (IS_ERR(trans))
5764 return PTR_ERR(trans);
5765
5766 err = btrfs_find_free_ino(root, &objectid);
5767 if (err)
5768 goto out_unlock;
5769
5770 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5771 dentry->d_name.len, btrfs_ino(dir), objectid,
5772 mode, &index);
5773 if (IS_ERR(inode)) {
5774 err = PTR_ERR(inode);
5775 goto out_unlock;
5776 }
5777
5778 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5779 if (err) {
5780 drop_inode = 1;
5781 goto out_unlock;
5782 }
5783
5784 /*
5785 * If the active LSM wants to access the inode during
5786 * d_instantiate it needs these. Smack checks to see
5787 * if the filesystem supports xattrs by looking at the
5788 * ops vector.
5789 */
5790
5791 inode->i_op = &btrfs_special_inode_operations;
5792 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5793 if (err)
5794 drop_inode = 1;
5795 else {
5796 init_special_inode(inode, inode->i_mode, rdev);
5797 btrfs_update_inode(trans, root, inode);
5798 d_instantiate(dentry, inode);
5799 }
5800 out_unlock:
5801 btrfs_end_transaction(trans, root);
5802 btrfs_btree_balance_dirty(root);
5803 if (drop_inode) {
5804 inode_dec_link_count(inode);
5805 iput(inode);
5806 }
5807 return err;
5808 }
5809
5810 static int btrfs_create(struct inode *dir, struct dentry *dentry,
5811 umode_t mode, bool excl)
5812 {
5813 struct btrfs_trans_handle *trans;
5814 struct btrfs_root *root = BTRFS_I(dir)->root;
5815 struct inode *inode = NULL;
5816 int drop_inode_on_err = 0;
5817 int err;
5818 u64 objectid;
5819 u64 index = 0;
5820
5821 /*
5822 * 2 for inode item and ref
5823 * 2 for dir items
5824 * 1 for xattr if selinux is on
5825 */
5826 trans = btrfs_start_transaction(root, 5);
5827 if (IS_ERR(trans))
5828 return PTR_ERR(trans);
5829
5830 err = btrfs_find_free_ino(root, &objectid);
5831 if (err)
5832 goto out_unlock;
5833
5834 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5835 dentry->d_name.len, btrfs_ino(dir), objectid,
5836 mode, &index);
5837 if (IS_ERR(inode)) {
5838 err = PTR_ERR(inode);
5839 goto out_unlock;
5840 }
5841 drop_inode_on_err = 1;
5842
5843 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5844 if (err)
5845 goto out_unlock;
5846
5847 err = btrfs_update_inode(trans, root, inode);
5848 if (err)
5849 goto out_unlock;
5850
5851 /*
5852 * If the active LSM wants to access the inode during
5853 * d_instantiate it needs these. Smack checks to see
5854 * if the filesystem supports xattrs by looking at the
5855 * ops vector.
5856 */
5857 inode->i_fop = &btrfs_file_operations;
5858 inode->i_op = &btrfs_file_inode_operations;
5859
5860 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5861 if (err)
5862 goto out_unlock;
5863
5864 inode->i_mapping->a_ops = &btrfs_aops;
5865 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
5866 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
5867 d_instantiate(dentry, inode);
5868
5869 out_unlock:
5870 btrfs_end_transaction(trans, root);
5871 if (err && drop_inode_on_err) {
5872 inode_dec_link_count(inode);
5873 iput(inode);
5874 }
5875 btrfs_btree_balance_dirty(root);
5876 return err;
5877 }
5878
5879 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
5880 struct dentry *dentry)
5881 {
5882 struct btrfs_trans_handle *trans;
5883 struct btrfs_root *root = BTRFS_I(dir)->root;
5884 struct inode *inode = old_dentry->d_inode;
5885 u64 index;
5886 int err;
5887 int drop_inode = 0;
5888
5889 /* do not allow sys_link's with other subvols of the same device */
5890 if (root->objectid != BTRFS_I(inode)->root->objectid)
5891 return -EXDEV;
5892
5893 if (inode->i_nlink >= BTRFS_LINK_MAX)
5894 return -EMLINK;
5895
5896 err = btrfs_set_inode_index(dir, &index);
5897 if (err)
5898 goto fail;
5899
5900 /*
5901 * 2 items for inode and inode ref
5902 * 2 items for dir items
5903 * 1 item for parent inode
5904 */
5905 trans = btrfs_start_transaction(root, 5);
5906 if (IS_ERR(trans)) {
5907 err = PTR_ERR(trans);
5908 goto fail;
5909 }
5910
5911 /* There are several dir indexes for this inode, clear the cache. */
5912 BTRFS_I(inode)->dir_index = 0ULL;
5913 inc_nlink(inode);
5914 inode_inc_iversion(inode);
5915 inode->i_ctime = CURRENT_TIME;
5916 ihold(inode);
5917 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
5918
5919 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
5920
5921 if (err) {
5922 drop_inode = 1;
5923 } else {
5924 struct dentry *parent = dentry->d_parent;
5925 err = btrfs_update_inode(trans, root, inode);
5926 if (err)
5927 goto fail;
5928 d_instantiate(dentry, inode);
5929 btrfs_log_new_name(trans, inode, NULL, parent);
5930 }
5931
5932 btrfs_end_transaction(trans, root);
5933 fail:
5934 if (drop_inode) {
5935 inode_dec_link_count(inode);
5936 iput(inode);
5937 }
5938 btrfs_btree_balance_dirty(root);
5939 return err;
5940 }
5941
5942 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
5943 {
5944 struct inode *inode = NULL;
5945 struct btrfs_trans_handle *trans;
5946 struct btrfs_root *root = BTRFS_I(dir)->root;
5947 int err = 0;
5948 int drop_on_err = 0;
5949 u64 objectid = 0;
5950 u64 index = 0;
5951
5952 /*
5953 * 2 items for inode and ref
5954 * 2 items for dir items
5955 * 1 for xattr if selinux is on
5956 */
5957 trans = btrfs_start_transaction(root, 5);
5958 if (IS_ERR(trans))
5959 return PTR_ERR(trans);
5960
5961 err = btrfs_find_free_ino(root, &objectid);
5962 if (err)
5963 goto out_fail;
5964
5965 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5966 dentry->d_name.len, btrfs_ino(dir), objectid,
5967 S_IFDIR | mode, &index);
5968 if (IS_ERR(inode)) {
5969 err = PTR_ERR(inode);
5970 goto out_fail;
5971 }
5972
5973 drop_on_err = 1;
5974
5975 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5976 if (err)
5977 goto out_fail;
5978
5979 inode->i_op = &btrfs_dir_inode_operations;
5980 inode->i_fop = &btrfs_dir_file_operations;
5981
5982 btrfs_i_size_write(inode, 0);
5983 err = btrfs_update_inode(trans, root, inode);
5984 if (err)
5985 goto out_fail;
5986
5987 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
5988 dentry->d_name.len, 0, index);
5989 if (err)
5990 goto out_fail;
5991
5992 d_instantiate(dentry, inode);
5993 drop_on_err = 0;
5994
5995 out_fail:
5996 btrfs_end_transaction(trans, root);
5997 if (drop_on_err)
5998 iput(inode);
5999 btrfs_btree_balance_dirty(root);
6000 return err;
6001 }
6002
6003 /* helper for btfs_get_extent. Given an existing extent in the tree,
6004 * and an extent that you want to insert, deal with overlap and insert
6005 * the new extent into the tree.
6006 */
6007 static int merge_extent_mapping(struct extent_map_tree *em_tree,
6008 struct extent_map *existing,
6009 struct extent_map *em,
6010 u64 map_start, u64 map_len)
6011 {
6012 u64 start_diff;
6013
6014 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
6015 start_diff = map_start - em->start;
6016 em->start = map_start;
6017 em->len = map_len;
6018 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
6019 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
6020 em->block_start += start_diff;
6021 em->block_len -= start_diff;
6022 }
6023 return add_extent_mapping(em_tree, em, 0);
6024 }
6025
6026 static noinline int uncompress_inline(struct btrfs_path *path,
6027 struct inode *inode, struct page *page,
6028 size_t pg_offset, u64 extent_offset,
6029 struct btrfs_file_extent_item *item)
6030 {
6031 int ret;
6032 struct extent_buffer *leaf = path->nodes[0];
6033 char *tmp;
6034 size_t max_size;
6035 unsigned long inline_size;
6036 unsigned long ptr;
6037 int compress_type;
6038
6039 WARN_ON(pg_offset != 0);
6040 compress_type = btrfs_file_extent_compression(leaf, item);
6041 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6042 inline_size = btrfs_file_extent_inline_item_len(leaf,
6043 btrfs_item_nr(path->slots[0]));
6044 tmp = kmalloc(inline_size, GFP_NOFS);
6045 if (!tmp)
6046 return -ENOMEM;
6047 ptr = btrfs_file_extent_inline_start(item);
6048
6049 read_extent_buffer(leaf, tmp, ptr, inline_size);
6050
6051 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
6052 ret = btrfs_decompress(compress_type, tmp, page,
6053 extent_offset, inline_size, max_size);
6054 if (ret) {
6055 char *kaddr = kmap_atomic(page);
6056 unsigned long copy_size = min_t(u64,
6057 PAGE_CACHE_SIZE - pg_offset,
6058 max_size - extent_offset);
6059 memset(kaddr + pg_offset, 0, copy_size);
6060 kunmap_atomic(kaddr);
6061 }
6062 kfree(tmp);
6063 return 0;
6064 }
6065
6066 /*
6067 * a bit scary, this does extent mapping from logical file offset to the disk.
6068 * the ugly parts come from merging extents from the disk with the in-ram
6069 * representation. This gets more complex because of the data=ordered code,
6070 * where the in-ram extents might be locked pending data=ordered completion.
6071 *
6072 * This also copies inline extents directly into the page.
6073 */
6074
6075 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
6076 size_t pg_offset, u64 start, u64 len,
6077 int create)
6078 {
6079 int ret;
6080 int err = 0;
6081 u64 bytenr;
6082 u64 extent_start = 0;
6083 u64 extent_end = 0;
6084 u64 objectid = btrfs_ino(inode);
6085 u32 found_type;
6086 struct btrfs_path *path = NULL;
6087 struct btrfs_root *root = BTRFS_I(inode)->root;
6088 struct btrfs_file_extent_item *item;
6089 struct extent_buffer *leaf;
6090 struct btrfs_key found_key;
6091 struct extent_map *em = NULL;
6092 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
6093 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6094 struct btrfs_trans_handle *trans = NULL;
6095 int compress_type;
6096
6097 again:
6098 read_lock(&em_tree->lock);
6099 em = lookup_extent_mapping(em_tree, start, len);
6100 if (em)
6101 em->bdev = root->fs_info->fs_devices->latest_bdev;
6102 read_unlock(&em_tree->lock);
6103
6104 if (em) {
6105 if (em->start > start || em->start + em->len <= start)
6106 free_extent_map(em);
6107 else if (em->block_start == EXTENT_MAP_INLINE && page)
6108 free_extent_map(em);
6109 else
6110 goto out;
6111 }
6112 em = alloc_extent_map();
6113 if (!em) {
6114 err = -ENOMEM;
6115 goto out;
6116 }
6117 em->bdev = root->fs_info->fs_devices->latest_bdev;
6118 em->start = EXTENT_MAP_HOLE;
6119 em->orig_start = EXTENT_MAP_HOLE;
6120 em->len = (u64)-1;
6121 em->block_len = (u64)-1;
6122
6123 if (!path) {
6124 path = btrfs_alloc_path();
6125 if (!path) {
6126 err = -ENOMEM;
6127 goto out;
6128 }
6129 /*
6130 * Chances are we'll be called again, so go ahead and do
6131 * readahead
6132 */
6133 path->reada = 1;
6134 }
6135
6136 ret = btrfs_lookup_file_extent(trans, root, path,
6137 objectid, start, trans != NULL);
6138 if (ret < 0) {
6139 err = ret;
6140 goto out;
6141 }
6142
6143 if (ret != 0) {
6144 if (path->slots[0] == 0)
6145 goto not_found;
6146 path->slots[0]--;
6147 }
6148
6149 leaf = path->nodes[0];
6150 item = btrfs_item_ptr(leaf, path->slots[0],
6151 struct btrfs_file_extent_item);
6152 /* are we inside the extent that was found? */
6153 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6154 found_type = btrfs_key_type(&found_key);
6155 if (found_key.objectid != objectid ||
6156 found_type != BTRFS_EXTENT_DATA_KEY) {
6157 /*
6158 * If we backup past the first extent we want to move forward
6159 * and see if there is an extent in front of us, otherwise we'll
6160 * say there is a hole for our whole search range which can
6161 * cause problems.
6162 */
6163 extent_end = start;
6164 goto next;
6165 }
6166
6167 found_type = btrfs_file_extent_type(leaf, item);
6168 extent_start = found_key.offset;
6169 compress_type = btrfs_file_extent_compression(leaf, item);
6170 if (found_type == BTRFS_FILE_EXTENT_REG ||
6171 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6172 extent_end = extent_start +
6173 btrfs_file_extent_num_bytes(leaf, item);
6174 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6175 size_t size;
6176 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6177 extent_end = ALIGN(extent_start + size, root->sectorsize);
6178 }
6179 next:
6180 if (start >= extent_end) {
6181 path->slots[0]++;
6182 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6183 ret = btrfs_next_leaf(root, path);
6184 if (ret < 0) {
6185 err = ret;
6186 goto out;
6187 }
6188 if (ret > 0)
6189 goto not_found;
6190 leaf = path->nodes[0];
6191 }
6192 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6193 if (found_key.objectid != objectid ||
6194 found_key.type != BTRFS_EXTENT_DATA_KEY)
6195 goto not_found;
6196 if (start + len <= found_key.offset)
6197 goto not_found;
6198 em->start = start;
6199 em->orig_start = start;
6200 em->len = found_key.offset - start;
6201 goto not_found_em;
6202 }
6203
6204 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, item);
6205 if (found_type == BTRFS_FILE_EXTENT_REG ||
6206 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6207 em->start = extent_start;
6208 em->len = extent_end - extent_start;
6209 em->orig_start = extent_start -
6210 btrfs_file_extent_offset(leaf, item);
6211 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf,
6212 item);
6213 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
6214 if (bytenr == 0) {
6215 em->block_start = EXTENT_MAP_HOLE;
6216 goto insert;
6217 }
6218 if (compress_type != BTRFS_COMPRESS_NONE) {
6219 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
6220 em->compress_type = compress_type;
6221 em->block_start = bytenr;
6222 em->block_len = em->orig_block_len;
6223 } else {
6224 bytenr += btrfs_file_extent_offset(leaf, item);
6225 em->block_start = bytenr;
6226 em->block_len = em->len;
6227 if (found_type == BTRFS_FILE_EXTENT_PREALLOC)
6228 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
6229 }
6230 goto insert;
6231 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6232 unsigned long ptr;
6233 char *map;
6234 size_t size;
6235 size_t extent_offset;
6236 size_t copy_size;
6237
6238 em->block_start = EXTENT_MAP_INLINE;
6239 if (!page || create) {
6240 em->start = extent_start;
6241 em->len = extent_end - extent_start;
6242 goto out;
6243 }
6244
6245 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6246 extent_offset = page_offset(page) + pg_offset - extent_start;
6247 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
6248 size - extent_offset);
6249 em->start = extent_start + extent_offset;
6250 em->len = ALIGN(copy_size, root->sectorsize);
6251 em->orig_block_len = em->len;
6252 em->orig_start = em->start;
6253 if (compress_type) {
6254 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
6255 em->compress_type = compress_type;
6256 }
6257 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6258 if (create == 0 && !PageUptodate(page)) {
6259 if (btrfs_file_extent_compression(leaf, item) !=
6260 BTRFS_COMPRESS_NONE) {
6261 ret = uncompress_inline(path, inode, page,
6262 pg_offset,
6263 extent_offset, item);
6264 BUG_ON(ret); /* -ENOMEM */
6265 } else {
6266 map = kmap(page);
6267 read_extent_buffer(leaf, map + pg_offset, ptr,
6268 copy_size);
6269 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
6270 memset(map + pg_offset + copy_size, 0,
6271 PAGE_CACHE_SIZE - pg_offset -
6272 copy_size);
6273 }
6274 kunmap(page);
6275 }
6276 flush_dcache_page(page);
6277 } else if (create && PageUptodate(page)) {
6278 BUG();
6279 if (!trans) {
6280 kunmap(page);
6281 free_extent_map(em);
6282 em = NULL;
6283
6284 btrfs_release_path(path);
6285 trans = btrfs_join_transaction(root);
6286
6287 if (IS_ERR(trans))
6288 return ERR_CAST(trans);
6289 goto again;
6290 }
6291 map = kmap(page);
6292 write_extent_buffer(leaf, map + pg_offset, ptr,
6293 copy_size);
6294 kunmap(page);
6295 btrfs_mark_buffer_dirty(leaf);
6296 }
6297 set_extent_uptodate(io_tree, em->start,
6298 extent_map_end(em) - 1, NULL, GFP_NOFS);
6299 goto insert;
6300 } else {
6301 WARN(1, KERN_ERR "btrfs unknown found_type %d\n", found_type);
6302 }
6303 not_found:
6304 em->start = start;
6305 em->orig_start = start;
6306 em->len = len;
6307 not_found_em:
6308 em->block_start = EXTENT_MAP_HOLE;
6309 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
6310 insert:
6311 btrfs_release_path(path);
6312 if (em->start > start || extent_map_end(em) <= start) {
6313 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
6314 em->start, em->len, start, len);
6315 err = -EIO;
6316 goto out;
6317 }
6318
6319 err = 0;
6320 write_lock(&em_tree->lock);
6321 ret = add_extent_mapping(em_tree, em, 0);
6322 /* it is possible that someone inserted the extent into the tree
6323 * while we had the lock dropped. It is also possible that
6324 * an overlapping map exists in the tree
6325 */
6326 if (ret == -EEXIST) {
6327 struct extent_map *existing;
6328
6329 ret = 0;
6330
6331 existing = lookup_extent_mapping(em_tree, start, len);
6332 if (existing && (existing->start > start ||
6333 existing->start + existing->len <= start)) {
6334 free_extent_map(existing);
6335 existing = NULL;
6336 }
6337 if (!existing) {
6338 existing = lookup_extent_mapping(em_tree, em->start,
6339 em->len);
6340 if (existing) {
6341 err = merge_extent_mapping(em_tree, existing,
6342 em, start,
6343 root->sectorsize);
6344 free_extent_map(existing);
6345 if (err) {
6346 free_extent_map(em);
6347 em = NULL;
6348 }
6349 } else {
6350 err = -EIO;
6351 free_extent_map(em);
6352 em = NULL;
6353 }
6354 } else {
6355 free_extent_map(em);
6356 em = existing;
6357 err = 0;
6358 }
6359 }
6360 write_unlock(&em_tree->lock);
6361 out:
6362
6363 trace_btrfs_get_extent(root, em);
6364
6365 if (path)
6366 btrfs_free_path(path);
6367 if (trans) {
6368 ret = btrfs_end_transaction(trans, root);
6369 if (!err)
6370 err = ret;
6371 }
6372 if (err) {
6373 free_extent_map(em);
6374 return ERR_PTR(err);
6375 }
6376 BUG_ON(!em); /* Error is always set */
6377 return em;
6378 }
6379
6380 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
6381 size_t pg_offset, u64 start, u64 len,
6382 int create)
6383 {
6384 struct extent_map *em;
6385 struct extent_map *hole_em = NULL;
6386 u64 range_start = start;
6387 u64 end;
6388 u64 found;
6389 u64 found_end;
6390 int err = 0;
6391
6392 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
6393 if (IS_ERR(em))
6394 return em;
6395 if (em) {
6396 /*
6397 * if our em maps to
6398 * - a hole or
6399 * - a pre-alloc extent,
6400 * there might actually be delalloc bytes behind it.
6401 */
6402 if (em->block_start != EXTENT_MAP_HOLE &&
6403 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6404 return em;
6405 else
6406 hole_em = em;
6407 }
6408
6409 /* check to see if we've wrapped (len == -1 or similar) */
6410 end = start + len;
6411 if (end < start)
6412 end = (u64)-1;
6413 else
6414 end -= 1;
6415
6416 em = NULL;
6417
6418 /* ok, we didn't find anything, lets look for delalloc */
6419 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
6420 end, len, EXTENT_DELALLOC, 1);
6421 found_end = range_start + found;
6422 if (found_end < range_start)
6423 found_end = (u64)-1;
6424
6425 /*
6426 * we didn't find anything useful, return
6427 * the original results from get_extent()
6428 */
6429 if (range_start > end || found_end <= start) {
6430 em = hole_em;
6431 hole_em = NULL;
6432 goto out;
6433 }
6434
6435 /* adjust the range_start to make sure it doesn't
6436 * go backwards from the start they passed in
6437 */
6438 range_start = max(start, range_start);
6439 found = found_end - range_start;
6440
6441 if (found > 0) {
6442 u64 hole_start = start;
6443 u64 hole_len = len;
6444
6445 em = alloc_extent_map();
6446 if (!em) {
6447 err = -ENOMEM;
6448 goto out;
6449 }
6450 /*
6451 * when btrfs_get_extent can't find anything it
6452 * returns one huge hole
6453 *
6454 * make sure what it found really fits our range, and
6455 * adjust to make sure it is based on the start from
6456 * the caller
6457 */
6458 if (hole_em) {
6459 u64 calc_end = extent_map_end(hole_em);
6460
6461 if (calc_end <= start || (hole_em->start > end)) {
6462 free_extent_map(hole_em);
6463 hole_em = NULL;
6464 } else {
6465 hole_start = max(hole_em->start, start);
6466 hole_len = calc_end - hole_start;
6467 }
6468 }
6469 em->bdev = NULL;
6470 if (hole_em && range_start > hole_start) {
6471 /* our hole starts before our delalloc, so we
6472 * have to return just the parts of the hole
6473 * that go until the delalloc starts
6474 */
6475 em->len = min(hole_len,
6476 range_start - hole_start);
6477 em->start = hole_start;
6478 em->orig_start = hole_start;
6479 /*
6480 * don't adjust block start at all,
6481 * it is fixed at EXTENT_MAP_HOLE
6482 */
6483 em->block_start = hole_em->block_start;
6484 em->block_len = hole_len;
6485 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
6486 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
6487 } else {
6488 em->start = range_start;
6489 em->len = found;
6490 em->orig_start = range_start;
6491 em->block_start = EXTENT_MAP_DELALLOC;
6492 em->block_len = found;
6493 }
6494 } else if (hole_em) {
6495 return hole_em;
6496 }
6497 out:
6498
6499 free_extent_map(hole_em);
6500 if (err) {
6501 free_extent_map(em);
6502 return ERR_PTR(err);
6503 }
6504 return em;
6505 }
6506
6507 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
6508 u64 start, u64 len)
6509 {
6510 struct btrfs_root *root = BTRFS_I(inode)->root;
6511 struct extent_map *em;
6512 struct btrfs_key ins;
6513 u64 alloc_hint;
6514 int ret;
6515
6516 alloc_hint = get_extent_allocation_hint(inode, start, len);
6517 ret = btrfs_reserve_extent(root, len, root->sectorsize, 0,
6518 alloc_hint, &ins, 1);
6519 if (ret)
6520 return ERR_PTR(ret);
6521
6522 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
6523 ins.offset, ins.offset, ins.offset, 0);
6524 if (IS_ERR(em)) {
6525 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
6526 return em;
6527 }
6528
6529 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
6530 ins.offset, ins.offset, 0);
6531 if (ret) {
6532 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
6533 free_extent_map(em);
6534 return ERR_PTR(ret);
6535 }
6536
6537 return em;
6538 }
6539
6540 /*
6541 * returns 1 when the nocow is safe, < 1 on error, 0 if the
6542 * block must be cow'd
6543 */
6544 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
6545 u64 *orig_start, u64 *orig_block_len,
6546 u64 *ram_bytes)
6547 {
6548 struct btrfs_trans_handle *trans;
6549 struct btrfs_path *path;
6550 int ret;
6551 struct extent_buffer *leaf;
6552 struct btrfs_root *root = BTRFS_I(inode)->root;
6553 struct btrfs_file_extent_item *fi;
6554 struct btrfs_key key;
6555 u64 disk_bytenr;
6556 u64 backref_offset;
6557 u64 extent_end;
6558 u64 num_bytes;
6559 int slot;
6560 int found_type;
6561 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
6562
6563 path = btrfs_alloc_path();
6564 if (!path)
6565 return -ENOMEM;
6566
6567 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
6568 offset, 0);
6569 if (ret < 0)
6570 goto out;
6571
6572 slot = path->slots[0];
6573 if (ret == 1) {
6574 if (slot == 0) {
6575 /* can't find the item, must cow */
6576 ret = 0;
6577 goto out;
6578 }
6579 slot--;
6580 }
6581 ret = 0;
6582 leaf = path->nodes[0];
6583 btrfs_item_key_to_cpu(leaf, &key, slot);
6584 if (key.objectid != btrfs_ino(inode) ||
6585 key.type != BTRFS_EXTENT_DATA_KEY) {
6586 /* not our file or wrong item type, must cow */
6587 goto out;
6588 }
6589
6590 if (key.offset > offset) {
6591 /* Wrong offset, must cow */
6592 goto out;
6593 }
6594
6595 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
6596 found_type = btrfs_file_extent_type(leaf, fi);
6597 if (found_type != BTRFS_FILE_EXTENT_REG &&
6598 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
6599 /* not a regular extent, must cow */
6600 goto out;
6601 }
6602
6603 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
6604 goto out;
6605
6606 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
6607 if (extent_end <= offset)
6608 goto out;
6609
6610 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
6611 if (disk_bytenr == 0)
6612 goto out;
6613
6614 if (btrfs_file_extent_compression(leaf, fi) ||
6615 btrfs_file_extent_encryption(leaf, fi) ||
6616 btrfs_file_extent_other_encoding(leaf, fi))
6617 goto out;
6618
6619 backref_offset = btrfs_file_extent_offset(leaf, fi);
6620
6621 if (orig_start) {
6622 *orig_start = key.offset - backref_offset;
6623 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
6624 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
6625 }
6626
6627 if (btrfs_extent_readonly(root, disk_bytenr))
6628 goto out;
6629 btrfs_release_path(path);
6630
6631 /*
6632 * look for other files referencing this extent, if we
6633 * find any we must cow
6634 */
6635 trans = btrfs_join_transaction(root);
6636 if (IS_ERR(trans)) {
6637 ret = 0;
6638 goto out;
6639 }
6640
6641 ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
6642 key.offset - backref_offset, disk_bytenr);
6643 btrfs_end_transaction(trans, root);
6644 if (ret) {
6645 ret = 0;
6646 goto out;
6647 }
6648
6649 /*
6650 * adjust disk_bytenr and num_bytes to cover just the bytes
6651 * in this extent we are about to write. If there
6652 * are any csums in that range we have to cow in order
6653 * to keep the csums correct
6654 */
6655 disk_bytenr += backref_offset;
6656 disk_bytenr += offset - key.offset;
6657 num_bytes = min(offset + *len, extent_end) - offset;
6658 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
6659 goto out;
6660 /*
6661 * all of the above have passed, it is safe to overwrite this extent
6662 * without cow
6663 */
6664 *len = num_bytes;
6665 ret = 1;
6666 out:
6667 btrfs_free_path(path);
6668 return ret;
6669 }
6670
6671 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
6672 struct extent_state **cached_state, int writing)
6673 {
6674 struct btrfs_ordered_extent *ordered;
6675 int ret = 0;
6676
6677 while (1) {
6678 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6679 0, cached_state);
6680 /*
6681 * We're concerned with the entire range that we're going to be
6682 * doing DIO to, so we need to make sure theres no ordered
6683 * extents in this range.
6684 */
6685 ordered = btrfs_lookup_ordered_range(inode, lockstart,
6686 lockend - lockstart + 1);
6687
6688 /*
6689 * We need to make sure there are no buffered pages in this
6690 * range either, we could have raced between the invalidate in
6691 * generic_file_direct_write and locking the extent. The
6692 * invalidate needs to happen so that reads after a write do not
6693 * get stale data.
6694 */
6695 if (!ordered && (!writing ||
6696 !test_range_bit(&BTRFS_I(inode)->io_tree,
6697 lockstart, lockend, EXTENT_UPTODATE, 0,
6698 *cached_state)))
6699 break;
6700
6701 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6702 cached_state, GFP_NOFS);
6703
6704 if (ordered) {
6705 btrfs_start_ordered_extent(inode, ordered, 1);
6706 btrfs_put_ordered_extent(ordered);
6707 } else {
6708 /* Screw you mmap */
6709 ret = filemap_write_and_wait_range(inode->i_mapping,
6710 lockstart,
6711 lockend);
6712 if (ret)
6713 break;
6714
6715 /*
6716 * If we found a page that couldn't be invalidated just
6717 * fall back to buffered.
6718 */
6719 ret = invalidate_inode_pages2_range(inode->i_mapping,
6720 lockstart >> PAGE_CACHE_SHIFT,
6721 lockend >> PAGE_CACHE_SHIFT);
6722 if (ret)
6723 break;
6724 }
6725
6726 cond_resched();
6727 }
6728
6729 return ret;
6730 }
6731
6732 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
6733 u64 len, u64 orig_start,
6734 u64 block_start, u64 block_len,
6735 u64 orig_block_len, u64 ram_bytes,
6736 int type)
6737 {
6738 struct extent_map_tree *em_tree;
6739 struct extent_map *em;
6740 struct btrfs_root *root = BTRFS_I(inode)->root;
6741 int ret;
6742
6743 em_tree = &BTRFS_I(inode)->extent_tree;
6744 em = alloc_extent_map();
6745 if (!em)
6746 return ERR_PTR(-ENOMEM);
6747
6748 em->start = start;
6749 em->orig_start = orig_start;
6750 em->mod_start = start;
6751 em->mod_len = len;
6752 em->len = len;
6753 em->block_len = block_len;
6754 em->block_start = block_start;
6755 em->bdev = root->fs_info->fs_devices->latest_bdev;
6756 em->orig_block_len = orig_block_len;
6757 em->ram_bytes = ram_bytes;
6758 em->generation = -1;
6759 set_bit(EXTENT_FLAG_PINNED, &em->flags);
6760 if (type == BTRFS_ORDERED_PREALLOC)
6761 set_bit(EXTENT_FLAG_FILLING, &em->flags);
6762
6763 do {
6764 btrfs_drop_extent_cache(inode, em->start,
6765 em->start + em->len - 1, 0);
6766 write_lock(&em_tree->lock);
6767 ret = add_extent_mapping(em_tree, em, 1);
6768 write_unlock(&em_tree->lock);
6769 } while (ret == -EEXIST);
6770
6771 if (ret) {
6772 free_extent_map(em);
6773 return ERR_PTR(ret);
6774 }
6775
6776 return em;
6777 }
6778
6779
6780 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
6781 struct buffer_head *bh_result, int create)
6782 {
6783 struct extent_map *em;
6784 struct btrfs_root *root = BTRFS_I(inode)->root;
6785 struct extent_state *cached_state = NULL;
6786 u64 start = iblock << inode->i_blkbits;
6787 u64 lockstart, lockend;
6788 u64 len = bh_result->b_size;
6789 int unlock_bits = EXTENT_LOCKED;
6790 int ret = 0;
6791
6792 if (create)
6793 unlock_bits |= EXTENT_DELALLOC | EXTENT_DIRTY;
6794 else
6795 len = min_t(u64, len, root->sectorsize);
6796
6797 lockstart = start;
6798 lockend = start + len - 1;
6799
6800 /*
6801 * If this errors out it's because we couldn't invalidate pagecache for
6802 * this range and we need to fallback to buffered.
6803 */
6804 if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create))
6805 return -ENOTBLK;
6806
6807 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
6808 if (IS_ERR(em)) {
6809 ret = PTR_ERR(em);
6810 goto unlock_err;
6811 }
6812
6813 /*
6814 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
6815 * io. INLINE is special, and we could probably kludge it in here, but
6816 * it's still buffered so for safety lets just fall back to the generic
6817 * buffered path.
6818 *
6819 * For COMPRESSED we _have_ to read the entire extent in so we can
6820 * decompress it, so there will be buffering required no matter what we
6821 * do, so go ahead and fallback to buffered.
6822 *
6823 * We return -ENOTBLK because thats what makes DIO go ahead and go back
6824 * to buffered IO. Don't blame me, this is the price we pay for using
6825 * the generic code.
6826 */
6827 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
6828 em->block_start == EXTENT_MAP_INLINE) {
6829 free_extent_map(em);
6830 ret = -ENOTBLK;
6831 goto unlock_err;
6832 }
6833
6834 /* Just a good old fashioned hole, return */
6835 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
6836 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
6837 free_extent_map(em);
6838 goto unlock_err;
6839 }
6840
6841 /*
6842 * We don't allocate a new extent in the following cases
6843 *
6844 * 1) The inode is marked as NODATACOW. In this case we'll just use the
6845 * existing extent.
6846 * 2) The extent is marked as PREALLOC. We're good to go here and can
6847 * just use the extent.
6848 *
6849 */
6850 if (!create) {
6851 len = min(len, em->len - (start - em->start));
6852 lockstart = start + len;
6853 goto unlock;
6854 }
6855
6856 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
6857 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
6858 em->block_start != EXTENT_MAP_HOLE)) {
6859 int type;
6860 int ret;
6861 u64 block_start, orig_start, orig_block_len, ram_bytes;
6862
6863 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6864 type = BTRFS_ORDERED_PREALLOC;
6865 else
6866 type = BTRFS_ORDERED_NOCOW;
6867 len = min(len, em->len - (start - em->start));
6868 block_start = em->block_start + (start - em->start);
6869
6870 if (can_nocow_extent(inode, start, &len, &orig_start,
6871 &orig_block_len, &ram_bytes) == 1) {
6872 if (type == BTRFS_ORDERED_PREALLOC) {
6873 free_extent_map(em);
6874 em = create_pinned_em(inode, start, len,
6875 orig_start,
6876 block_start, len,
6877 orig_block_len,
6878 ram_bytes, type);
6879 if (IS_ERR(em))
6880 goto unlock_err;
6881 }
6882
6883 ret = btrfs_add_ordered_extent_dio(inode, start,
6884 block_start, len, len, type);
6885 if (ret) {
6886 free_extent_map(em);
6887 goto unlock_err;
6888 }
6889 goto unlock;
6890 }
6891 }
6892
6893 /*
6894 * this will cow the extent, reset the len in case we changed
6895 * it above
6896 */
6897 len = bh_result->b_size;
6898 free_extent_map(em);
6899 em = btrfs_new_extent_direct(inode, start, len);
6900 if (IS_ERR(em)) {
6901 ret = PTR_ERR(em);
6902 goto unlock_err;
6903 }
6904 len = min(len, em->len - (start - em->start));
6905 unlock:
6906 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
6907 inode->i_blkbits;
6908 bh_result->b_size = len;
6909 bh_result->b_bdev = em->bdev;
6910 set_buffer_mapped(bh_result);
6911 if (create) {
6912 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6913 set_buffer_new(bh_result);
6914
6915 /*
6916 * Need to update the i_size under the extent lock so buffered
6917 * readers will get the updated i_size when we unlock.
6918 */
6919 if (start + len > i_size_read(inode))
6920 i_size_write(inode, start + len);
6921
6922 spin_lock(&BTRFS_I(inode)->lock);
6923 BTRFS_I(inode)->outstanding_extents++;
6924 spin_unlock(&BTRFS_I(inode)->lock);
6925
6926 ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6927 lockstart + len - 1, EXTENT_DELALLOC, NULL,
6928 &cached_state, GFP_NOFS);
6929 BUG_ON(ret);
6930 }
6931
6932 /*
6933 * In the case of write we need to clear and unlock the entire range,
6934 * in the case of read we need to unlock only the end area that we
6935 * aren't using if there is any left over space.
6936 */
6937 if (lockstart < lockend) {
6938 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6939 lockend, unlock_bits, 1, 0,
6940 &cached_state, GFP_NOFS);
6941 } else {
6942 free_extent_state(cached_state);
6943 }
6944
6945 free_extent_map(em);
6946
6947 return 0;
6948
6949 unlock_err:
6950 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6951 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
6952 return ret;
6953 }
6954
6955 static void btrfs_endio_direct_read(struct bio *bio, int err)
6956 {
6957 struct btrfs_dio_private *dip = bio->bi_private;
6958 struct bio_vec *bvec;
6959 struct inode *inode = dip->inode;
6960 struct btrfs_root *root = BTRFS_I(inode)->root;
6961 struct bio *dio_bio;
6962 u32 *csums = (u32 *)dip->csum;
6963 u64 start;
6964 int i;
6965
6966 start = dip->logical_offset;
6967 bio_for_each_segment_all(bvec, bio, i) {
6968 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
6969 struct page *page = bvec->bv_page;
6970 char *kaddr;
6971 u32 csum = ~(u32)0;
6972 unsigned long flags;
6973
6974 local_irq_save(flags);
6975 kaddr = kmap_atomic(page);
6976 csum = btrfs_csum_data(kaddr + bvec->bv_offset,
6977 csum, bvec->bv_len);
6978 btrfs_csum_final(csum, (char *)&csum);
6979 kunmap_atomic(kaddr);
6980 local_irq_restore(flags);
6981
6982 flush_dcache_page(bvec->bv_page);
6983 if (csum != csums[i]) {
6984 btrfs_err(root->fs_info, "csum failed ino %llu off %llu csum %u expected csum %u",
6985 btrfs_ino(inode), start, csum,
6986 csums[i]);
6987 err = -EIO;
6988 }
6989 }
6990
6991 start += bvec->bv_len;
6992 }
6993
6994 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
6995 dip->logical_offset + dip->bytes - 1);
6996 dio_bio = dip->dio_bio;
6997
6998 kfree(dip);
6999
7000 /* If we had a csum failure make sure to clear the uptodate flag */
7001 if (err)
7002 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags);
7003 dio_end_io(dio_bio, err);
7004 bio_put(bio);
7005 }
7006
7007 static void btrfs_endio_direct_write(struct bio *bio, int err)
7008 {
7009 struct btrfs_dio_private *dip = bio->bi_private;
7010 struct inode *inode = dip->inode;
7011 struct btrfs_root *root = BTRFS_I(inode)->root;
7012 struct btrfs_ordered_extent *ordered = NULL;
7013 u64 ordered_offset = dip->logical_offset;
7014 u64 ordered_bytes = dip->bytes;
7015 struct bio *dio_bio;
7016 int ret;
7017
7018 if (err)
7019 goto out_done;
7020 again:
7021 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
7022 &ordered_offset,
7023 ordered_bytes, !err);
7024 if (!ret)
7025 goto out_test;
7026
7027 ordered->work.func = finish_ordered_fn;
7028 ordered->work.flags = 0;
7029 btrfs_queue_worker(&root->fs_info->endio_write_workers,
7030 &ordered->work);
7031 out_test:
7032 /*
7033 * our bio might span multiple ordered extents. If we haven't
7034 * completed the accounting for the whole dio, go back and try again
7035 */
7036 if (ordered_offset < dip->logical_offset + dip->bytes) {
7037 ordered_bytes = dip->logical_offset + dip->bytes -
7038 ordered_offset;
7039 ordered = NULL;
7040 goto again;
7041 }
7042 out_done:
7043 dio_bio = dip->dio_bio;
7044
7045 kfree(dip);
7046
7047 /* If we had an error make sure to clear the uptodate flag */
7048 if (err)
7049 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags);
7050 dio_end_io(dio_bio, err);
7051 bio_put(bio);
7052 }
7053
7054 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
7055 struct bio *bio, int mirror_num,
7056 unsigned long bio_flags, u64 offset)
7057 {
7058 int ret;
7059 struct btrfs_root *root = BTRFS_I(inode)->root;
7060 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
7061 BUG_ON(ret); /* -ENOMEM */
7062 return 0;
7063 }
7064
7065 static void btrfs_end_dio_bio(struct bio *bio, int err)
7066 {
7067 struct btrfs_dio_private *dip = bio->bi_private;
7068
7069 if (err) {
7070 btrfs_err(BTRFS_I(dip->inode)->root->fs_info,
7071 "direct IO failed ino %llu rw %lu sector %#Lx len %u err no %d",
7072 btrfs_ino(dip->inode), bio->bi_rw,
7073 (unsigned long long)bio->bi_iter.bi_sector,
7074 bio->bi_iter.bi_size, err);
7075 dip->errors = 1;
7076
7077 /*
7078 * before atomic variable goto zero, we must make sure
7079 * dip->errors is perceived to be set.
7080 */
7081 smp_mb__before_atomic_dec();
7082 }
7083
7084 /* if there are more bios still pending for this dio, just exit */
7085 if (!atomic_dec_and_test(&dip->pending_bios))
7086 goto out;
7087
7088 if (dip->errors) {
7089 bio_io_error(dip->orig_bio);
7090 } else {
7091 set_bit(BIO_UPTODATE, &dip->dio_bio->bi_flags);
7092 bio_endio(dip->orig_bio, 0);
7093 }
7094 out:
7095 bio_put(bio);
7096 }
7097
7098 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
7099 u64 first_sector, gfp_t gfp_flags)
7100 {
7101 int nr_vecs = bio_get_nr_vecs(bdev);
7102 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
7103 }
7104
7105 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
7106 int rw, u64 file_offset, int skip_sum,
7107 int async_submit)
7108 {
7109 struct btrfs_dio_private *dip = bio->bi_private;
7110 int write = rw & REQ_WRITE;
7111 struct btrfs_root *root = BTRFS_I(inode)->root;
7112 int ret;
7113
7114 if (async_submit)
7115 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
7116
7117 bio_get(bio);
7118
7119 if (!write) {
7120 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
7121 if (ret)
7122 goto err;
7123 }
7124
7125 if (skip_sum)
7126 goto map;
7127
7128 if (write && async_submit) {
7129 ret = btrfs_wq_submit_bio(root->fs_info,
7130 inode, rw, bio, 0, 0,
7131 file_offset,
7132 __btrfs_submit_bio_start_direct_io,
7133 __btrfs_submit_bio_done);
7134 goto err;
7135 } else if (write) {
7136 /*
7137 * If we aren't doing async submit, calculate the csum of the
7138 * bio now.
7139 */
7140 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
7141 if (ret)
7142 goto err;
7143 } else if (!skip_sum) {
7144 ret = btrfs_lookup_bio_sums_dio(root, inode, dip, bio,
7145 file_offset);
7146 if (ret)
7147 goto err;
7148 }
7149
7150 map:
7151 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
7152 err:
7153 bio_put(bio);
7154 return ret;
7155 }
7156
7157 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
7158 int skip_sum)
7159 {
7160 struct inode *inode = dip->inode;
7161 struct btrfs_root *root = BTRFS_I(inode)->root;
7162 struct bio *bio;
7163 struct bio *orig_bio = dip->orig_bio;
7164 struct bio_vec *bvec = orig_bio->bi_io_vec;
7165 u64 start_sector = orig_bio->bi_iter.bi_sector;
7166 u64 file_offset = dip->logical_offset;
7167 u64 submit_len = 0;
7168 u64 map_length;
7169 int nr_pages = 0;
7170 int ret = 0;
7171 int async_submit = 0;
7172
7173 map_length = orig_bio->bi_iter.bi_size;
7174 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
7175 &map_length, NULL, 0);
7176 if (ret) {
7177 bio_put(orig_bio);
7178 return -EIO;
7179 }
7180
7181 if (map_length >= orig_bio->bi_iter.bi_size) {
7182 bio = orig_bio;
7183 goto submit;
7184 }
7185
7186 /* async crcs make it difficult to collect full stripe writes. */
7187 if (btrfs_get_alloc_profile(root, 1) &
7188 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6))
7189 async_submit = 0;
7190 else
7191 async_submit = 1;
7192
7193 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
7194 if (!bio)
7195 return -ENOMEM;
7196 bio->bi_private = dip;
7197 bio->bi_end_io = btrfs_end_dio_bio;
7198 atomic_inc(&dip->pending_bios);
7199
7200 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
7201 if (unlikely(map_length < submit_len + bvec->bv_len ||
7202 bio_add_page(bio, bvec->bv_page, bvec->bv_len,
7203 bvec->bv_offset) < bvec->bv_len)) {
7204 /*
7205 * inc the count before we submit the bio so
7206 * we know the end IO handler won't happen before
7207 * we inc the count. Otherwise, the dip might get freed
7208 * before we're done setting it up
7209 */
7210 atomic_inc(&dip->pending_bios);
7211 ret = __btrfs_submit_dio_bio(bio, inode, rw,
7212 file_offset, skip_sum,
7213 async_submit);
7214 if (ret) {
7215 bio_put(bio);
7216 atomic_dec(&dip->pending_bios);
7217 goto out_err;
7218 }
7219
7220 start_sector += submit_len >> 9;
7221 file_offset += submit_len;
7222
7223 submit_len = 0;
7224 nr_pages = 0;
7225
7226 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
7227 start_sector, GFP_NOFS);
7228 if (!bio)
7229 goto out_err;
7230 bio->bi_private = dip;
7231 bio->bi_end_io = btrfs_end_dio_bio;
7232
7233 map_length = orig_bio->bi_iter.bi_size;
7234 ret = btrfs_map_block(root->fs_info, rw,
7235 start_sector << 9,
7236 &map_length, NULL, 0);
7237 if (ret) {
7238 bio_put(bio);
7239 goto out_err;
7240 }
7241 } else {
7242 submit_len += bvec->bv_len;
7243 nr_pages++;
7244 bvec++;
7245 }
7246 }
7247
7248 submit:
7249 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
7250 async_submit);
7251 if (!ret)
7252 return 0;
7253
7254 bio_put(bio);
7255 out_err:
7256 dip->errors = 1;
7257 /*
7258 * before atomic variable goto zero, we must
7259 * make sure dip->errors is perceived to be set.
7260 */
7261 smp_mb__before_atomic_dec();
7262 if (atomic_dec_and_test(&dip->pending_bios))
7263 bio_io_error(dip->orig_bio);
7264
7265 /* bio_end_io() will handle error, so we needn't return it */
7266 return 0;
7267 }
7268
7269 static void btrfs_submit_direct(int rw, struct bio *dio_bio,
7270 struct inode *inode, loff_t file_offset)
7271 {
7272 struct btrfs_root *root = BTRFS_I(inode)->root;
7273 struct btrfs_dio_private *dip;
7274 struct bio *io_bio;
7275 int skip_sum;
7276 int sum_len;
7277 int write = rw & REQ_WRITE;
7278 int ret = 0;
7279 u16 csum_size;
7280
7281 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
7282
7283 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
7284 if (!io_bio) {
7285 ret = -ENOMEM;
7286 goto free_ordered;
7287 }
7288
7289 if (!skip_sum && !write) {
7290 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
7291 sum_len = dio_bio->bi_iter.bi_size >>
7292 inode->i_sb->s_blocksize_bits;
7293 sum_len *= csum_size;
7294 } else {
7295 sum_len = 0;
7296 }
7297
7298 dip = kmalloc(sizeof(*dip) + sum_len, GFP_NOFS);
7299 if (!dip) {
7300 ret = -ENOMEM;
7301 goto free_io_bio;
7302 }
7303
7304 dip->private = dio_bio->bi_private;
7305 dip->inode = inode;
7306 dip->logical_offset = file_offset;
7307 dip->bytes = dio_bio->bi_iter.bi_size;
7308 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
7309 io_bio->bi_private = dip;
7310 dip->errors = 0;
7311 dip->orig_bio = io_bio;
7312 dip->dio_bio = dio_bio;
7313 atomic_set(&dip->pending_bios, 0);
7314
7315 if (write)
7316 io_bio->bi_end_io = btrfs_endio_direct_write;
7317 else
7318 io_bio->bi_end_io = btrfs_endio_direct_read;
7319
7320 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
7321 if (!ret)
7322 return;
7323
7324 free_io_bio:
7325 bio_put(io_bio);
7326
7327 free_ordered:
7328 /*
7329 * If this is a write, we need to clean up the reserved space and kill
7330 * the ordered extent.
7331 */
7332 if (write) {
7333 struct btrfs_ordered_extent *ordered;
7334 ordered = btrfs_lookup_ordered_extent(inode, file_offset);
7335 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
7336 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
7337 btrfs_free_reserved_extent(root, ordered->start,
7338 ordered->disk_len);
7339 btrfs_put_ordered_extent(ordered);
7340 btrfs_put_ordered_extent(ordered);
7341 }
7342 bio_endio(dio_bio, ret);
7343 }
7344
7345 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb,
7346 const struct iovec *iov, loff_t offset,
7347 unsigned long nr_segs)
7348 {
7349 int seg;
7350 int i;
7351 size_t size;
7352 unsigned long addr;
7353 unsigned blocksize_mask = root->sectorsize - 1;
7354 ssize_t retval = -EINVAL;
7355 loff_t end = offset;
7356
7357 if (offset & blocksize_mask)
7358 goto out;
7359
7360 /* Check the memory alignment. Blocks cannot straddle pages */
7361 for (seg = 0; seg < nr_segs; seg++) {
7362 addr = (unsigned long)iov[seg].iov_base;
7363 size = iov[seg].iov_len;
7364 end += size;
7365 if ((addr & blocksize_mask) || (size & blocksize_mask))
7366 goto out;
7367
7368 /* If this is a write we don't need to check anymore */
7369 if (rw & WRITE)
7370 continue;
7371
7372 /*
7373 * Check to make sure we don't have duplicate iov_base's in this
7374 * iovec, if so return EINVAL, otherwise we'll get csum errors
7375 * when reading back.
7376 */
7377 for (i = seg + 1; i < nr_segs; i++) {
7378 if (iov[seg].iov_base == iov[i].iov_base)
7379 goto out;
7380 }
7381 }
7382 retval = 0;
7383 out:
7384 return retval;
7385 }
7386
7387 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
7388 const struct iovec *iov, loff_t offset,
7389 unsigned long nr_segs)
7390 {
7391 struct file *file = iocb->ki_filp;
7392 struct inode *inode = file->f_mapping->host;
7393 size_t count = 0;
7394 int flags = 0;
7395 bool wakeup = true;
7396 bool relock = false;
7397 ssize_t ret;
7398
7399 if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
7400 offset, nr_segs))
7401 return 0;
7402
7403 atomic_inc(&inode->i_dio_count);
7404 smp_mb__after_atomic_inc();
7405
7406 /*
7407 * The generic stuff only does filemap_write_and_wait_range, which isn't
7408 * enough if we've written compressed pages to this area, so we need to
7409 * call btrfs_wait_ordered_range to make absolutely sure that any
7410 * outstanding dirty pages are on disk.
7411 */
7412 count = iov_length(iov, nr_segs);
7413 ret = btrfs_wait_ordered_range(inode, offset, count);
7414 if (ret)
7415 return ret;
7416
7417 if (rw & WRITE) {
7418 /*
7419 * If the write DIO is beyond the EOF, we need update
7420 * the isize, but it is protected by i_mutex. So we can
7421 * not unlock the i_mutex at this case.
7422 */
7423 if (offset + count <= inode->i_size) {
7424 mutex_unlock(&inode->i_mutex);
7425 relock = true;
7426 }
7427 ret = btrfs_delalloc_reserve_space(inode, count);
7428 if (ret)
7429 goto out;
7430 } else if (unlikely(test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
7431 &BTRFS_I(inode)->runtime_flags))) {
7432 inode_dio_done(inode);
7433 flags = DIO_LOCKING | DIO_SKIP_HOLES;
7434 wakeup = false;
7435 }
7436
7437 ret = __blockdev_direct_IO(rw, iocb, inode,
7438 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
7439 iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
7440 btrfs_submit_direct, flags);
7441 if (rw & WRITE) {
7442 if (ret < 0 && ret != -EIOCBQUEUED)
7443 btrfs_delalloc_release_space(inode, count);
7444 else if (ret >= 0 && (size_t)ret < count)
7445 btrfs_delalloc_release_space(inode,
7446 count - (size_t)ret);
7447 else
7448 btrfs_delalloc_release_metadata(inode, 0);
7449 }
7450 out:
7451 if (wakeup)
7452 inode_dio_done(inode);
7453 if (relock)
7454 mutex_lock(&inode->i_mutex);
7455
7456 return ret;
7457 }
7458
7459 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
7460
7461 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
7462 __u64 start, __u64 len)
7463 {
7464 int ret;
7465
7466 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
7467 if (ret)
7468 return ret;
7469
7470 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
7471 }
7472
7473 int btrfs_readpage(struct file *file, struct page *page)
7474 {
7475 struct extent_io_tree *tree;
7476 tree = &BTRFS_I(page->mapping->host)->io_tree;
7477 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
7478 }
7479
7480 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
7481 {
7482 struct extent_io_tree *tree;
7483
7484
7485 if (current->flags & PF_MEMALLOC) {
7486 redirty_page_for_writepage(wbc, page);
7487 unlock_page(page);
7488 return 0;
7489 }
7490 tree = &BTRFS_I(page->mapping->host)->io_tree;
7491 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
7492 }
7493
7494 static int btrfs_writepages(struct address_space *mapping,
7495 struct writeback_control *wbc)
7496 {
7497 struct extent_io_tree *tree;
7498
7499 tree = &BTRFS_I(mapping->host)->io_tree;
7500 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
7501 }
7502
7503 static int
7504 btrfs_readpages(struct file *file, struct address_space *mapping,
7505 struct list_head *pages, unsigned nr_pages)
7506 {
7507 struct extent_io_tree *tree;
7508 tree = &BTRFS_I(mapping->host)->io_tree;
7509 return extent_readpages(tree, mapping, pages, nr_pages,
7510 btrfs_get_extent);
7511 }
7512 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
7513 {
7514 struct extent_io_tree *tree;
7515 struct extent_map_tree *map;
7516 int ret;
7517
7518 tree = &BTRFS_I(page->mapping->host)->io_tree;
7519 map = &BTRFS_I(page->mapping->host)->extent_tree;
7520 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
7521 if (ret == 1) {
7522 ClearPagePrivate(page);
7523 set_page_private(page, 0);
7524 page_cache_release(page);
7525 }
7526 return ret;
7527 }
7528
7529 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
7530 {
7531 if (PageWriteback(page) || PageDirty(page))
7532 return 0;
7533 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
7534 }
7535
7536 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
7537 unsigned int length)
7538 {
7539 struct inode *inode = page->mapping->host;
7540 struct extent_io_tree *tree;
7541 struct btrfs_ordered_extent *ordered;
7542 struct extent_state *cached_state = NULL;
7543 u64 page_start = page_offset(page);
7544 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
7545 int inode_evicting = inode->i_state & I_FREEING;
7546
7547 /*
7548 * we have the page locked, so new writeback can't start,
7549 * and the dirty bit won't be cleared while we are here.
7550 *
7551 * Wait for IO on this page so that we can safely clear
7552 * the PagePrivate2 bit and do ordered accounting
7553 */
7554 wait_on_page_writeback(page);
7555
7556 tree = &BTRFS_I(inode)->io_tree;
7557 if (offset) {
7558 btrfs_releasepage(page, GFP_NOFS);
7559 return;
7560 }
7561
7562 if (!inode_evicting)
7563 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
7564 ordered = btrfs_lookup_ordered_extent(inode, page_start);
7565 if (ordered) {
7566 /*
7567 * IO on this page will never be started, so we need
7568 * to account for any ordered extents now
7569 */
7570 if (!inode_evicting)
7571 clear_extent_bit(tree, page_start, page_end,
7572 EXTENT_DIRTY | EXTENT_DELALLOC |
7573 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
7574 EXTENT_DEFRAG, 1, 0, &cached_state,
7575 GFP_NOFS);
7576 /*
7577 * whoever cleared the private bit is responsible
7578 * for the finish_ordered_io
7579 */
7580 if (TestClearPagePrivate2(page)) {
7581 struct btrfs_ordered_inode_tree *tree;
7582 u64 new_len;
7583
7584 tree = &BTRFS_I(inode)->ordered_tree;
7585
7586 spin_lock_irq(&tree->lock);
7587 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
7588 new_len = page_start - ordered->file_offset;
7589 if (new_len < ordered->truncated_len)
7590 ordered->truncated_len = new_len;
7591 spin_unlock_irq(&tree->lock);
7592
7593 if (btrfs_dec_test_ordered_pending(inode, &ordered,
7594 page_start,
7595 PAGE_CACHE_SIZE, 1))
7596 btrfs_finish_ordered_io(ordered);
7597 }
7598 btrfs_put_ordered_extent(ordered);
7599 if (!inode_evicting) {
7600 cached_state = NULL;
7601 lock_extent_bits(tree, page_start, page_end, 0,
7602 &cached_state);
7603 }
7604 }
7605
7606 if (!inode_evicting) {
7607 clear_extent_bit(tree, page_start, page_end,
7608 EXTENT_LOCKED | EXTENT_DIRTY |
7609 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
7610 EXTENT_DEFRAG, 1, 1,
7611 &cached_state, GFP_NOFS);
7612
7613 __btrfs_releasepage(page, GFP_NOFS);
7614 }
7615
7616 ClearPageChecked(page);
7617 if (PagePrivate(page)) {
7618 ClearPagePrivate(page);
7619 set_page_private(page, 0);
7620 page_cache_release(page);
7621 }
7622 }
7623
7624 /*
7625 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
7626 * called from a page fault handler when a page is first dirtied. Hence we must
7627 * be careful to check for EOF conditions here. We set the page up correctly
7628 * for a written page which means we get ENOSPC checking when writing into
7629 * holes and correct delalloc and unwritten extent mapping on filesystems that
7630 * support these features.
7631 *
7632 * We are not allowed to take the i_mutex here so we have to play games to
7633 * protect against truncate races as the page could now be beyond EOF. Because
7634 * vmtruncate() writes the inode size before removing pages, once we have the
7635 * page lock we can determine safely if the page is beyond EOF. If it is not
7636 * beyond EOF, then the page is guaranteed safe against truncation until we
7637 * unlock the page.
7638 */
7639 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
7640 {
7641 struct page *page = vmf->page;
7642 struct inode *inode = file_inode(vma->vm_file);
7643 struct btrfs_root *root = BTRFS_I(inode)->root;
7644 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7645 struct btrfs_ordered_extent *ordered;
7646 struct extent_state *cached_state = NULL;
7647 char *kaddr;
7648 unsigned long zero_start;
7649 loff_t size;
7650 int ret;
7651 int reserved = 0;
7652 u64 page_start;
7653 u64 page_end;
7654
7655 sb_start_pagefault(inode->i_sb);
7656 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
7657 if (!ret) {
7658 ret = file_update_time(vma->vm_file);
7659 reserved = 1;
7660 }
7661 if (ret) {
7662 if (ret == -ENOMEM)
7663 ret = VM_FAULT_OOM;
7664 else /* -ENOSPC, -EIO, etc */
7665 ret = VM_FAULT_SIGBUS;
7666 if (reserved)
7667 goto out;
7668 goto out_noreserve;
7669 }
7670
7671 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
7672 again:
7673 lock_page(page);
7674 size = i_size_read(inode);
7675 page_start = page_offset(page);
7676 page_end = page_start + PAGE_CACHE_SIZE - 1;
7677
7678 if ((page->mapping != inode->i_mapping) ||
7679 (page_start >= size)) {
7680 /* page got truncated out from underneath us */
7681 goto out_unlock;
7682 }
7683 wait_on_page_writeback(page);
7684
7685 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
7686 set_page_extent_mapped(page);
7687
7688 /*
7689 * we can't set the delalloc bits if there are pending ordered
7690 * extents. Drop our locks and wait for them to finish
7691 */
7692 ordered = btrfs_lookup_ordered_extent(inode, page_start);
7693 if (ordered) {
7694 unlock_extent_cached(io_tree, page_start, page_end,
7695 &cached_state, GFP_NOFS);
7696 unlock_page(page);
7697 btrfs_start_ordered_extent(inode, ordered, 1);
7698 btrfs_put_ordered_extent(ordered);
7699 goto again;
7700 }
7701
7702 /*
7703 * XXX - page_mkwrite gets called every time the page is dirtied, even
7704 * if it was already dirty, so for space accounting reasons we need to
7705 * clear any delalloc bits for the range we are fixing to save. There
7706 * is probably a better way to do this, but for now keep consistent with
7707 * prepare_pages in the normal write path.
7708 */
7709 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
7710 EXTENT_DIRTY | EXTENT_DELALLOC |
7711 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
7712 0, 0, &cached_state, GFP_NOFS);
7713
7714 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
7715 &cached_state);
7716 if (ret) {
7717 unlock_extent_cached(io_tree, page_start, page_end,
7718 &cached_state, GFP_NOFS);
7719 ret = VM_FAULT_SIGBUS;
7720 goto out_unlock;
7721 }
7722 ret = 0;
7723
7724 /* page is wholly or partially inside EOF */
7725 if (page_start + PAGE_CACHE_SIZE > size)
7726 zero_start = size & ~PAGE_CACHE_MASK;
7727 else
7728 zero_start = PAGE_CACHE_SIZE;
7729
7730 if (zero_start != PAGE_CACHE_SIZE) {
7731 kaddr = kmap(page);
7732 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
7733 flush_dcache_page(page);
7734 kunmap(page);
7735 }
7736 ClearPageChecked(page);
7737 set_page_dirty(page);
7738 SetPageUptodate(page);
7739
7740 BTRFS_I(inode)->last_trans = root->fs_info->generation;
7741 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
7742 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
7743
7744 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
7745
7746 out_unlock:
7747 if (!ret) {
7748 sb_end_pagefault(inode->i_sb);
7749 return VM_FAULT_LOCKED;
7750 }
7751 unlock_page(page);
7752 out:
7753 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
7754 out_noreserve:
7755 sb_end_pagefault(inode->i_sb);
7756 return ret;
7757 }
7758
7759 static int btrfs_truncate(struct inode *inode)
7760 {
7761 struct btrfs_root *root = BTRFS_I(inode)->root;
7762 struct btrfs_block_rsv *rsv;
7763 int ret = 0;
7764 int err = 0;
7765 struct btrfs_trans_handle *trans;
7766 u64 mask = root->sectorsize - 1;
7767 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
7768
7769 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
7770 (u64)-1);
7771 if (ret)
7772 return ret;
7773
7774 /*
7775 * Yes ladies and gentelment, this is indeed ugly. The fact is we have
7776 * 3 things going on here
7777 *
7778 * 1) We need to reserve space for our orphan item and the space to
7779 * delete our orphan item. Lord knows we don't want to have a dangling
7780 * orphan item because we didn't reserve space to remove it.
7781 *
7782 * 2) We need to reserve space to update our inode.
7783 *
7784 * 3) We need to have something to cache all the space that is going to
7785 * be free'd up by the truncate operation, but also have some slack
7786 * space reserved in case it uses space during the truncate (thank you
7787 * very much snapshotting).
7788 *
7789 * And we need these to all be seperate. The fact is we can use alot of
7790 * space doing the truncate, and we have no earthly idea how much space
7791 * we will use, so we need the truncate reservation to be seperate so it
7792 * doesn't end up using space reserved for updating the inode or
7793 * removing the orphan item. We also need to be able to stop the
7794 * transaction and start a new one, which means we need to be able to
7795 * update the inode several times, and we have no idea of knowing how
7796 * many times that will be, so we can't just reserve 1 item for the
7797 * entirety of the opration, so that has to be done seperately as well.
7798 * Then there is the orphan item, which does indeed need to be held on
7799 * to for the whole operation, and we need nobody to touch this reserved
7800 * space except the orphan code.
7801 *
7802 * So that leaves us with
7803 *
7804 * 1) root->orphan_block_rsv - for the orphan deletion.
7805 * 2) rsv - for the truncate reservation, which we will steal from the
7806 * transaction reservation.
7807 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
7808 * updating the inode.
7809 */
7810 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
7811 if (!rsv)
7812 return -ENOMEM;
7813 rsv->size = min_size;
7814 rsv->failfast = 1;
7815
7816 /*
7817 * 1 for the truncate slack space
7818 * 1 for updating the inode.
7819 */
7820 trans = btrfs_start_transaction(root, 2);
7821 if (IS_ERR(trans)) {
7822 err = PTR_ERR(trans);
7823 goto out;
7824 }
7825
7826 /* Migrate the slack space for the truncate to our reserve */
7827 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
7828 min_size);
7829 BUG_ON(ret);
7830
7831 /*
7832 * setattr is responsible for setting the ordered_data_close flag,
7833 * but that is only tested during the last file release. That
7834 * could happen well after the next commit, leaving a great big
7835 * window where new writes may get lost if someone chooses to write
7836 * to this file after truncating to zero
7837 *
7838 * The inode doesn't have any dirty data here, and so if we commit
7839 * this is a noop. If someone immediately starts writing to the inode
7840 * it is very likely we'll catch some of their writes in this
7841 * transaction, and the commit will find this file on the ordered
7842 * data list with good things to send down.
7843 *
7844 * This is a best effort solution, there is still a window where
7845 * using truncate to replace the contents of the file will
7846 * end up with a zero length file after a crash.
7847 */
7848 if (inode->i_size == 0 && test_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
7849 &BTRFS_I(inode)->runtime_flags))
7850 btrfs_add_ordered_operation(trans, root, inode);
7851
7852 /*
7853 * So if we truncate and then write and fsync we normally would just
7854 * write the extents that changed, which is a problem if we need to
7855 * first truncate that entire inode. So set this flag so we write out
7856 * all of the extents in the inode to the sync log so we're completely
7857 * safe.
7858 */
7859 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
7860 trans->block_rsv = rsv;
7861
7862 while (1) {
7863 ret = btrfs_truncate_inode_items(trans, root, inode,
7864 inode->i_size,
7865 BTRFS_EXTENT_DATA_KEY);
7866 if (ret != -ENOSPC) {
7867 err = ret;
7868 break;
7869 }
7870
7871 trans->block_rsv = &root->fs_info->trans_block_rsv;
7872 ret = btrfs_update_inode(trans, root, inode);
7873 if (ret) {
7874 err = ret;
7875 break;
7876 }
7877
7878 btrfs_end_transaction(trans, root);
7879 btrfs_btree_balance_dirty(root);
7880
7881 trans = btrfs_start_transaction(root, 2);
7882 if (IS_ERR(trans)) {
7883 ret = err = PTR_ERR(trans);
7884 trans = NULL;
7885 break;
7886 }
7887
7888 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
7889 rsv, min_size);
7890 BUG_ON(ret); /* shouldn't happen */
7891 trans->block_rsv = rsv;
7892 }
7893
7894 if (ret == 0 && inode->i_nlink > 0) {
7895 trans->block_rsv = root->orphan_block_rsv;
7896 ret = btrfs_orphan_del(trans, inode);
7897 if (ret)
7898 err = ret;
7899 }
7900
7901 if (trans) {
7902 trans->block_rsv = &root->fs_info->trans_block_rsv;
7903 ret = btrfs_update_inode(trans, root, inode);
7904 if (ret && !err)
7905 err = ret;
7906
7907 ret = btrfs_end_transaction(trans, root);
7908 btrfs_btree_balance_dirty(root);
7909 }
7910
7911 out:
7912 btrfs_free_block_rsv(root, rsv);
7913
7914 if (ret && !err)
7915 err = ret;
7916
7917 return err;
7918 }
7919
7920 /*
7921 * create a new subvolume directory/inode (helper for the ioctl).
7922 */
7923 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
7924 struct btrfs_root *new_root,
7925 struct btrfs_root *parent_root,
7926 u64 new_dirid)
7927 {
7928 struct inode *inode;
7929 int err;
7930 u64 index = 0;
7931
7932 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
7933 new_dirid, new_dirid,
7934 S_IFDIR | (~current_umask() & S_IRWXUGO),
7935 &index);
7936 if (IS_ERR(inode))
7937 return PTR_ERR(inode);
7938 inode->i_op = &btrfs_dir_inode_operations;
7939 inode->i_fop = &btrfs_dir_file_operations;
7940
7941 set_nlink(inode, 1);
7942 btrfs_i_size_write(inode, 0);
7943
7944 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
7945 if (err)
7946 btrfs_err(new_root->fs_info,
7947 "error inheriting subvolume %llu properties: %d\n",
7948 new_root->root_key.objectid, err);
7949
7950 err = btrfs_update_inode(trans, new_root, inode);
7951
7952 iput(inode);
7953 return err;
7954 }
7955
7956 struct inode *btrfs_alloc_inode(struct super_block *sb)
7957 {
7958 struct btrfs_inode *ei;
7959 struct inode *inode;
7960
7961 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
7962 if (!ei)
7963 return NULL;
7964
7965 ei->root = NULL;
7966 ei->generation = 0;
7967 ei->last_trans = 0;
7968 ei->last_sub_trans = 0;
7969 ei->logged_trans = 0;
7970 ei->delalloc_bytes = 0;
7971 ei->disk_i_size = 0;
7972 ei->flags = 0;
7973 ei->csum_bytes = 0;
7974 ei->index_cnt = (u64)-1;
7975 ei->dir_index = 0;
7976 ei->last_unlink_trans = 0;
7977 ei->last_log_commit = 0;
7978
7979 spin_lock_init(&ei->lock);
7980 ei->outstanding_extents = 0;
7981 ei->reserved_extents = 0;
7982
7983 ei->runtime_flags = 0;
7984 ei->force_compress = BTRFS_COMPRESS_NONE;
7985
7986 ei->delayed_node = NULL;
7987
7988 inode = &ei->vfs_inode;
7989 extent_map_tree_init(&ei->extent_tree);
7990 extent_io_tree_init(&ei->io_tree, &inode->i_data);
7991 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
7992 ei->io_tree.track_uptodate = 1;
7993 ei->io_failure_tree.track_uptodate = 1;
7994 atomic_set(&ei->sync_writers, 0);
7995 mutex_init(&ei->log_mutex);
7996 mutex_init(&ei->delalloc_mutex);
7997 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
7998 INIT_LIST_HEAD(&ei->delalloc_inodes);
7999 INIT_LIST_HEAD(&ei->ordered_operations);
8000 RB_CLEAR_NODE(&ei->rb_node);
8001
8002 return inode;
8003 }
8004
8005 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
8006 void btrfs_test_destroy_inode(struct inode *inode)
8007 {
8008 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
8009 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
8010 }
8011 #endif
8012
8013 static void btrfs_i_callback(struct rcu_head *head)
8014 {
8015 struct inode *inode = container_of(head, struct inode, i_rcu);
8016 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
8017 }
8018
8019 void btrfs_destroy_inode(struct inode *inode)
8020 {
8021 struct btrfs_ordered_extent *ordered;
8022 struct btrfs_root *root = BTRFS_I(inode)->root;
8023
8024 WARN_ON(!hlist_empty(&inode->i_dentry));
8025 WARN_ON(inode->i_data.nrpages);
8026 WARN_ON(BTRFS_I(inode)->outstanding_extents);
8027 WARN_ON(BTRFS_I(inode)->reserved_extents);
8028 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
8029 WARN_ON(BTRFS_I(inode)->csum_bytes);
8030
8031 /*
8032 * This can happen where we create an inode, but somebody else also
8033 * created the same inode and we need to destroy the one we already
8034 * created.
8035 */
8036 if (!root)
8037 goto free;
8038
8039 /*
8040 * Make sure we're properly removed from the ordered operation
8041 * lists.
8042 */
8043 smp_mb();
8044 if (!list_empty(&BTRFS_I(inode)->ordered_operations)) {
8045 spin_lock(&root->fs_info->ordered_root_lock);
8046 list_del_init(&BTRFS_I(inode)->ordered_operations);
8047 spin_unlock(&root->fs_info->ordered_root_lock);
8048 }
8049
8050 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
8051 &BTRFS_I(inode)->runtime_flags)) {
8052 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
8053 btrfs_ino(inode));
8054 atomic_dec(&root->orphan_inodes);
8055 }
8056
8057 while (1) {
8058 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
8059 if (!ordered)
8060 break;
8061 else {
8062 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
8063 ordered->file_offset, ordered->len);
8064 btrfs_remove_ordered_extent(inode, ordered);
8065 btrfs_put_ordered_extent(ordered);
8066 btrfs_put_ordered_extent(ordered);
8067 }
8068 }
8069 inode_tree_del(inode);
8070 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
8071 free:
8072 call_rcu(&inode->i_rcu, btrfs_i_callback);
8073 }
8074
8075 int btrfs_drop_inode(struct inode *inode)
8076 {
8077 struct btrfs_root *root = BTRFS_I(inode)->root;
8078
8079 if (root == NULL)
8080 return 1;
8081
8082 /* the snap/subvol tree is on deleting */
8083 if (btrfs_root_refs(&root->root_item) == 0)
8084 return 1;
8085 else
8086 return generic_drop_inode(inode);
8087 }
8088
8089 static void init_once(void *foo)
8090 {
8091 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
8092
8093 inode_init_once(&ei->vfs_inode);
8094 }
8095
8096 void btrfs_destroy_cachep(void)
8097 {
8098 /*
8099 * Make sure all delayed rcu free inodes are flushed before we
8100 * destroy cache.
8101 */
8102 rcu_barrier();
8103 if (btrfs_inode_cachep)
8104 kmem_cache_destroy(btrfs_inode_cachep);
8105 if (btrfs_trans_handle_cachep)
8106 kmem_cache_destroy(btrfs_trans_handle_cachep);
8107 if (btrfs_transaction_cachep)
8108 kmem_cache_destroy(btrfs_transaction_cachep);
8109 if (btrfs_path_cachep)
8110 kmem_cache_destroy(btrfs_path_cachep);
8111 if (btrfs_free_space_cachep)
8112 kmem_cache_destroy(btrfs_free_space_cachep);
8113 if (btrfs_delalloc_work_cachep)
8114 kmem_cache_destroy(btrfs_delalloc_work_cachep);
8115 }
8116
8117 int btrfs_init_cachep(void)
8118 {
8119 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
8120 sizeof(struct btrfs_inode), 0,
8121 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
8122 if (!btrfs_inode_cachep)
8123 goto fail;
8124
8125 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
8126 sizeof(struct btrfs_trans_handle), 0,
8127 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8128 if (!btrfs_trans_handle_cachep)
8129 goto fail;
8130
8131 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
8132 sizeof(struct btrfs_transaction), 0,
8133 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8134 if (!btrfs_transaction_cachep)
8135 goto fail;
8136
8137 btrfs_path_cachep = kmem_cache_create("btrfs_path",
8138 sizeof(struct btrfs_path), 0,
8139 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8140 if (!btrfs_path_cachep)
8141 goto fail;
8142
8143 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
8144 sizeof(struct btrfs_free_space), 0,
8145 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8146 if (!btrfs_free_space_cachep)
8147 goto fail;
8148
8149 btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work",
8150 sizeof(struct btrfs_delalloc_work), 0,
8151 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
8152 NULL);
8153 if (!btrfs_delalloc_work_cachep)
8154 goto fail;
8155
8156 return 0;
8157 fail:
8158 btrfs_destroy_cachep();
8159 return -ENOMEM;
8160 }
8161
8162 static int btrfs_getattr(struct vfsmount *mnt,
8163 struct dentry *dentry, struct kstat *stat)
8164 {
8165 u64 delalloc_bytes;
8166 struct inode *inode = dentry->d_inode;
8167 u32 blocksize = inode->i_sb->s_blocksize;
8168
8169 generic_fillattr(inode, stat);
8170 stat->dev = BTRFS_I(inode)->root->anon_dev;
8171 stat->blksize = PAGE_CACHE_SIZE;
8172
8173 spin_lock(&BTRFS_I(inode)->lock);
8174 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
8175 spin_unlock(&BTRFS_I(inode)->lock);
8176 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
8177 ALIGN(delalloc_bytes, blocksize)) >> 9;
8178 return 0;
8179 }
8180
8181 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
8182 struct inode *new_dir, struct dentry *new_dentry)
8183 {
8184 struct btrfs_trans_handle *trans;
8185 struct btrfs_root *root = BTRFS_I(old_dir)->root;
8186 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
8187 struct inode *new_inode = new_dentry->d_inode;
8188 struct inode *old_inode = old_dentry->d_inode;
8189 struct timespec ctime = CURRENT_TIME;
8190 u64 index = 0;
8191 u64 root_objectid;
8192 int ret;
8193 u64 old_ino = btrfs_ino(old_inode);
8194
8195 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
8196 return -EPERM;
8197
8198 /* we only allow rename subvolume link between subvolumes */
8199 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
8200 return -EXDEV;
8201
8202 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
8203 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
8204 return -ENOTEMPTY;
8205
8206 if (S_ISDIR(old_inode->i_mode) && new_inode &&
8207 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
8208 return -ENOTEMPTY;
8209
8210
8211 /* check for collisions, even if the name isn't there */
8212 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
8213 new_dentry->d_name.name,
8214 new_dentry->d_name.len);
8215
8216 if (ret) {
8217 if (ret == -EEXIST) {
8218 /* we shouldn't get
8219 * eexist without a new_inode */
8220 if (WARN_ON(!new_inode)) {
8221 return ret;
8222 }
8223 } else {
8224 /* maybe -EOVERFLOW */
8225 return ret;
8226 }
8227 }
8228 ret = 0;
8229
8230 /*
8231 * we're using rename to replace one file with another.
8232 * and the replacement file is large. Start IO on it now so
8233 * we don't add too much work to the end of the transaction
8234 */
8235 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size &&
8236 old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
8237 filemap_flush(old_inode->i_mapping);
8238
8239 /* close the racy window with snapshot create/destroy ioctl */
8240 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
8241 down_read(&root->fs_info->subvol_sem);
8242 /*
8243 * We want to reserve the absolute worst case amount of items. So if
8244 * both inodes are subvols and we need to unlink them then that would
8245 * require 4 item modifications, but if they are both normal inodes it
8246 * would require 5 item modifications, so we'll assume their normal
8247 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
8248 * should cover the worst case number of items we'll modify.
8249 */
8250 trans = btrfs_start_transaction(root, 11);
8251 if (IS_ERR(trans)) {
8252 ret = PTR_ERR(trans);
8253 goto out_notrans;
8254 }
8255
8256 if (dest != root)
8257 btrfs_record_root_in_trans(trans, dest);
8258
8259 ret = btrfs_set_inode_index(new_dir, &index);
8260 if (ret)
8261 goto out_fail;
8262
8263 BTRFS_I(old_inode)->dir_index = 0ULL;
8264 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
8265 /* force full log commit if subvolume involved. */
8266 root->fs_info->last_trans_log_full_commit = trans->transid;
8267 } else {
8268 ret = btrfs_insert_inode_ref(trans, dest,
8269 new_dentry->d_name.name,
8270 new_dentry->d_name.len,
8271 old_ino,
8272 btrfs_ino(new_dir), index);
8273 if (ret)
8274 goto out_fail;
8275 /*
8276 * this is an ugly little race, but the rename is required
8277 * to make sure that if we crash, the inode is either at the
8278 * old name or the new one. pinning the log transaction lets
8279 * us make sure we don't allow a log commit to come in after
8280 * we unlink the name but before we add the new name back in.
8281 */
8282 btrfs_pin_log_trans(root);
8283 }
8284 /*
8285 * make sure the inode gets flushed if it is replacing
8286 * something.
8287 */
8288 if (new_inode && new_inode->i_size && S_ISREG(old_inode->i_mode))
8289 btrfs_add_ordered_operation(trans, root, old_inode);
8290
8291 inode_inc_iversion(old_dir);
8292 inode_inc_iversion(new_dir);
8293 inode_inc_iversion(old_inode);
8294 old_dir->i_ctime = old_dir->i_mtime = ctime;
8295 new_dir->i_ctime = new_dir->i_mtime = ctime;
8296 old_inode->i_ctime = ctime;
8297
8298 if (old_dentry->d_parent != new_dentry->d_parent)
8299 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
8300
8301 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
8302 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
8303 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
8304 old_dentry->d_name.name,
8305 old_dentry->d_name.len);
8306 } else {
8307 ret = __btrfs_unlink_inode(trans, root, old_dir,
8308 old_dentry->d_inode,
8309 old_dentry->d_name.name,
8310 old_dentry->d_name.len);
8311 if (!ret)
8312 ret = btrfs_update_inode(trans, root, old_inode);
8313 }
8314 if (ret) {
8315 btrfs_abort_transaction(trans, root, ret);
8316 goto out_fail;
8317 }
8318
8319 if (new_inode) {
8320 inode_inc_iversion(new_inode);
8321 new_inode->i_ctime = CURRENT_TIME;
8322 if (unlikely(btrfs_ino(new_inode) ==
8323 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
8324 root_objectid = BTRFS_I(new_inode)->location.objectid;
8325 ret = btrfs_unlink_subvol(trans, dest, new_dir,
8326 root_objectid,
8327 new_dentry->d_name.name,
8328 new_dentry->d_name.len);
8329 BUG_ON(new_inode->i_nlink == 0);
8330 } else {
8331 ret = btrfs_unlink_inode(trans, dest, new_dir,
8332 new_dentry->d_inode,
8333 new_dentry->d_name.name,
8334 new_dentry->d_name.len);
8335 }
8336 if (!ret && new_inode->i_nlink == 0)
8337 ret = btrfs_orphan_add(trans, new_dentry->d_inode);
8338 if (ret) {
8339 btrfs_abort_transaction(trans, root, ret);
8340 goto out_fail;
8341 }
8342 }
8343
8344 ret = btrfs_add_link(trans, new_dir, old_inode,
8345 new_dentry->d_name.name,
8346 new_dentry->d_name.len, 0, index);
8347 if (ret) {
8348 btrfs_abort_transaction(trans, root, ret);
8349 goto out_fail;
8350 }
8351
8352 if (old_inode->i_nlink == 1)
8353 BTRFS_I(old_inode)->dir_index = index;
8354
8355 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
8356 struct dentry *parent = new_dentry->d_parent;
8357 btrfs_log_new_name(trans, old_inode, old_dir, parent);
8358 btrfs_end_log_trans(root);
8359 }
8360 out_fail:
8361 btrfs_end_transaction(trans, root);
8362 out_notrans:
8363 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
8364 up_read(&root->fs_info->subvol_sem);
8365
8366 return ret;
8367 }
8368
8369 static void btrfs_run_delalloc_work(struct btrfs_work *work)
8370 {
8371 struct btrfs_delalloc_work *delalloc_work;
8372 struct inode *inode;
8373
8374 delalloc_work = container_of(work, struct btrfs_delalloc_work,
8375 work);
8376 inode = delalloc_work->inode;
8377 if (delalloc_work->wait) {
8378 btrfs_wait_ordered_range(inode, 0, (u64)-1);
8379 } else {
8380 filemap_flush(inode->i_mapping);
8381 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8382 &BTRFS_I(inode)->runtime_flags))
8383 filemap_flush(inode->i_mapping);
8384 }
8385
8386 if (delalloc_work->delay_iput)
8387 btrfs_add_delayed_iput(inode);
8388 else
8389 iput(inode);
8390 complete(&delalloc_work->completion);
8391 }
8392
8393 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
8394 int wait, int delay_iput)
8395 {
8396 struct btrfs_delalloc_work *work;
8397
8398 work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS);
8399 if (!work)
8400 return NULL;
8401
8402 init_completion(&work->completion);
8403 INIT_LIST_HEAD(&work->list);
8404 work->inode = inode;
8405 work->wait = wait;
8406 work->delay_iput = delay_iput;
8407 work->work.func = btrfs_run_delalloc_work;
8408
8409 return work;
8410 }
8411
8412 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
8413 {
8414 wait_for_completion(&work->completion);
8415 kmem_cache_free(btrfs_delalloc_work_cachep, work);
8416 }
8417
8418 /*
8419 * some fairly slow code that needs optimization. This walks the list
8420 * of all the inodes with pending delalloc and forces them to disk.
8421 */
8422 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
8423 {
8424 struct btrfs_inode *binode;
8425 struct inode *inode;
8426 struct btrfs_delalloc_work *work, *next;
8427 struct list_head works;
8428 struct list_head splice;
8429 int ret = 0;
8430
8431 INIT_LIST_HEAD(&works);
8432 INIT_LIST_HEAD(&splice);
8433
8434 spin_lock(&root->delalloc_lock);
8435 list_splice_init(&root->delalloc_inodes, &splice);
8436 while (!list_empty(&splice)) {
8437 binode = list_entry(splice.next, struct btrfs_inode,
8438 delalloc_inodes);
8439
8440 list_move_tail(&binode->delalloc_inodes,
8441 &root->delalloc_inodes);
8442 inode = igrab(&binode->vfs_inode);
8443 if (!inode) {
8444 cond_resched_lock(&root->delalloc_lock);
8445 continue;
8446 }
8447 spin_unlock(&root->delalloc_lock);
8448
8449 work = btrfs_alloc_delalloc_work(inode, 0, delay_iput);
8450 if (unlikely(!work)) {
8451 if (delay_iput)
8452 btrfs_add_delayed_iput(inode);
8453 else
8454 iput(inode);
8455 ret = -ENOMEM;
8456 goto out;
8457 }
8458 list_add_tail(&work->list, &works);
8459 btrfs_queue_worker(&root->fs_info->flush_workers,
8460 &work->work);
8461
8462 cond_resched();
8463 spin_lock(&root->delalloc_lock);
8464 }
8465 spin_unlock(&root->delalloc_lock);
8466
8467 list_for_each_entry_safe(work, next, &works, list) {
8468 list_del_init(&work->list);
8469 btrfs_wait_and_free_delalloc_work(work);
8470 }
8471 return 0;
8472 out:
8473 list_for_each_entry_safe(work, next, &works, list) {
8474 list_del_init(&work->list);
8475 btrfs_wait_and_free_delalloc_work(work);
8476 }
8477
8478 if (!list_empty_careful(&splice)) {
8479 spin_lock(&root->delalloc_lock);
8480 list_splice_tail(&splice, &root->delalloc_inodes);
8481 spin_unlock(&root->delalloc_lock);
8482 }
8483 return ret;
8484 }
8485
8486 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
8487 {
8488 int ret;
8489
8490 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
8491 return -EROFS;
8492
8493 ret = __start_delalloc_inodes(root, delay_iput);
8494 /*
8495 * the filemap_flush will queue IO into the worker threads, but
8496 * we have to make sure the IO is actually started and that
8497 * ordered extents get created before we return
8498 */
8499 atomic_inc(&root->fs_info->async_submit_draining);
8500 while (atomic_read(&root->fs_info->nr_async_submits) ||
8501 atomic_read(&root->fs_info->async_delalloc_pages)) {
8502 wait_event(root->fs_info->async_submit_wait,
8503 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
8504 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
8505 }
8506 atomic_dec(&root->fs_info->async_submit_draining);
8507 return ret;
8508 }
8509
8510 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput)
8511 {
8512 struct btrfs_root *root;
8513 struct list_head splice;
8514 int ret;
8515
8516 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
8517 return -EROFS;
8518
8519 INIT_LIST_HEAD(&splice);
8520
8521 spin_lock(&fs_info->delalloc_root_lock);
8522 list_splice_init(&fs_info->delalloc_roots, &splice);
8523 while (!list_empty(&splice)) {
8524 root = list_first_entry(&splice, struct btrfs_root,
8525 delalloc_root);
8526 root = btrfs_grab_fs_root(root);
8527 BUG_ON(!root);
8528 list_move_tail(&root->delalloc_root,
8529 &fs_info->delalloc_roots);
8530 spin_unlock(&fs_info->delalloc_root_lock);
8531
8532 ret = __start_delalloc_inodes(root, delay_iput);
8533 btrfs_put_fs_root(root);
8534 if (ret)
8535 goto out;
8536
8537 spin_lock(&fs_info->delalloc_root_lock);
8538 }
8539 spin_unlock(&fs_info->delalloc_root_lock);
8540
8541 atomic_inc(&fs_info->async_submit_draining);
8542 while (atomic_read(&fs_info->nr_async_submits) ||
8543 atomic_read(&fs_info->async_delalloc_pages)) {
8544 wait_event(fs_info->async_submit_wait,
8545 (atomic_read(&fs_info->nr_async_submits) == 0 &&
8546 atomic_read(&fs_info->async_delalloc_pages) == 0));
8547 }
8548 atomic_dec(&fs_info->async_submit_draining);
8549 return 0;
8550 out:
8551 if (!list_empty_careful(&splice)) {
8552 spin_lock(&fs_info->delalloc_root_lock);
8553 list_splice_tail(&splice, &fs_info->delalloc_roots);
8554 spin_unlock(&fs_info->delalloc_root_lock);
8555 }
8556 return ret;
8557 }
8558
8559 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
8560 const char *symname)
8561 {
8562 struct btrfs_trans_handle *trans;
8563 struct btrfs_root *root = BTRFS_I(dir)->root;
8564 struct btrfs_path *path;
8565 struct btrfs_key key;
8566 struct inode *inode = NULL;
8567 int err;
8568 int drop_inode = 0;
8569 u64 objectid;
8570 u64 index = 0;
8571 int name_len;
8572 int datasize;
8573 unsigned long ptr;
8574 struct btrfs_file_extent_item *ei;
8575 struct extent_buffer *leaf;
8576
8577 name_len = strlen(symname);
8578 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
8579 return -ENAMETOOLONG;
8580
8581 /*
8582 * 2 items for inode item and ref
8583 * 2 items for dir items
8584 * 1 item for xattr if selinux is on
8585 */
8586 trans = btrfs_start_transaction(root, 5);
8587 if (IS_ERR(trans))
8588 return PTR_ERR(trans);
8589
8590 err = btrfs_find_free_ino(root, &objectid);
8591 if (err)
8592 goto out_unlock;
8593
8594 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
8595 dentry->d_name.len, btrfs_ino(dir), objectid,
8596 S_IFLNK|S_IRWXUGO, &index);
8597 if (IS_ERR(inode)) {
8598 err = PTR_ERR(inode);
8599 goto out_unlock;
8600 }
8601
8602 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
8603 if (err) {
8604 drop_inode = 1;
8605 goto out_unlock;
8606 }
8607
8608 /*
8609 * If the active LSM wants to access the inode during
8610 * d_instantiate it needs these. Smack checks to see
8611 * if the filesystem supports xattrs by looking at the
8612 * ops vector.
8613 */
8614 inode->i_fop = &btrfs_file_operations;
8615 inode->i_op = &btrfs_file_inode_operations;
8616
8617 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
8618 if (err)
8619 drop_inode = 1;
8620 else {
8621 inode->i_mapping->a_ops = &btrfs_aops;
8622 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
8623 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
8624 }
8625 if (drop_inode)
8626 goto out_unlock;
8627
8628 path = btrfs_alloc_path();
8629 if (!path) {
8630 err = -ENOMEM;
8631 drop_inode = 1;
8632 goto out_unlock;
8633 }
8634 key.objectid = btrfs_ino(inode);
8635 key.offset = 0;
8636 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
8637 datasize = btrfs_file_extent_calc_inline_size(name_len);
8638 err = btrfs_insert_empty_item(trans, root, path, &key,
8639 datasize);
8640 if (err) {
8641 drop_inode = 1;
8642 btrfs_free_path(path);
8643 goto out_unlock;
8644 }
8645 leaf = path->nodes[0];
8646 ei = btrfs_item_ptr(leaf, path->slots[0],
8647 struct btrfs_file_extent_item);
8648 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
8649 btrfs_set_file_extent_type(leaf, ei,
8650 BTRFS_FILE_EXTENT_INLINE);
8651 btrfs_set_file_extent_encryption(leaf, ei, 0);
8652 btrfs_set_file_extent_compression(leaf, ei, 0);
8653 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
8654 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
8655
8656 ptr = btrfs_file_extent_inline_start(ei);
8657 write_extent_buffer(leaf, symname, ptr, name_len);
8658 btrfs_mark_buffer_dirty(leaf);
8659 btrfs_free_path(path);
8660
8661 inode->i_op = &btrfs_symlink_inode_operations;
8662 inode->i_mapping->a_ops = &btrfs_symlink_aops;
8663 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
8664 inode_set_bytes(inode, name_len);
8665 btrfs_i_size_write(inode, name_len);
8666 err = btrfs_update_inode(trans, root, inode);
8667 if (err)
8668 drop_inode = 1;
8669
8670 out_unlock:
8671 if (!err)
8672 d_instantiate(dentry, inode);
8673 btrfs_end_transaction(trans, root);
8674 if (drop_inode) {
8675 inode_dec_link_count(inode);
8676 iput(inode);
8677 }
8678 btrfs_btree_balance_dirty(root);
8679 return err;
8680 }
8681
8682 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
8683 u64 start, u64 num_bytes, u64 min_size,
8684 loff_t actual_len, u64 *alloc_hint,
8685 struct btrfs_trans_handle *trans)
8686 {
8687 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
8688 struct extent_map *em;
8689 struct btrfs_root *root = BTRFS_I(inode)->root;
8690 struct btrfs_key ins;
8691 u64 cur_offset = start;
8692 u64 i_size;
8693 u64 cur_bytes;
8694 int ret = 0;
8695 bool own_trans = true;
8696
8697 if (trans)
8698 own_trans = false;
8699 while (num_bytes > 0) {
8700 if (own_trans) {
8701 trans = btrfs_start_transaction(root, 3);
8702 if (IS_ERR(trans)) {
8703 ret = PTR_ERR(trans);
8704 break;
8705 }
8706 }
8707
8708 cur_bytes = min(num_bytes, 256ULL * 1024 * 1024);
8709 cur_bytes = max(cur_bytes, min_size);
8710 ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0,
8711 *alloc_hint, &ins, 1);
8712 if (ret) {
8713 if (own_trans)
8714 btrfs_end_transaction(trans, root);
8715 break;
8716 }
8717
8718 ret = insert_reserved_file_extent(trans, inode,
8719 cur_offset, ins.objectid,
8720 ins.offset, ins.offset,
8721 ins.offset, 0, 0, 0,
8722 BTRFS_FILE_EXTENT_PREALLOC);
8723 if (ret) {
8724 btrfs_free_reserved_extent(root, ins.objectid,
8725 ins.offset);
8726 btrfs_abort_transaction(trans, root, ret);
8727 if (own_trans)
8728 btrfs_end_transaction(trans, root);
8729 break;
8730 }
8731 btrfs_drop_extent_cache(inode, cur_offset,
8732 cur_offset + ins.offset -1, 0);
8733
8734 em = alloc_extent_map();
8735 if (!em) {
8736 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
8737 &BTRFS_I(inode)->runtime_flags);
8738 goto next;
8739 }
8740
8741 em->start = cur_offset;
8742 em->orig_start = cur_offset;
8743 em->len = ins.offset;
8744 em->block_start = ins.objectid;
8745 em->block_len = ins.offset;
8746 em->orig_block_len = ins.offset;
8747 em->ram_bytes = ins.offset;
8748 em->bdev = root->fs_info->fs_devices->latest_bdev;
8749 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
8750 em->generation = trans->transid;
8751
8752 while (1) {
8753 write_lock(&em_tree->lock);
8754 ret = add_extent_mapping(em_tree, em, 1);
8755 write_unlock(&em_tree->lock);
8756 if (ret != -EEXIST)
8757 break;
8758 btrfs_drop_extent_cache(inode, cur_offset,
8759 cur_offset + ins.offset - 1,
8760 0);
8761 }
8762 free_extent_map(em);
8763 next:
8764 num_bytes -= ins.offset;
8765 cur_offset += ins.offset;
8766 *alloc_hint = ins.objectid + ins.offset;
8767
8768 inode_inc_iversion(inode);
8769 inode->i_ctime = CURRENT_TIME;
8770 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
8771 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
8772 (actual_len > inode->i_size) &&
8773 (cur_offset > inode->i_size)) {
8774 if (cur_offset > actual_len)
8775 i_size = actual_len;
8776 else
8777 i_size = cur_offset;
8778 i_size_write(inode, i_size);
8779 btrfs_ordered_update_i_size(inode, i_size, NULL);
8780 }
8781
8782 ret = btrfs_update_inode(trans, root, inode);
8783
8784 if (ret) {
8785 btrfs_abort_transaction(trans, root, ret);
8786 if (own_trans)
8787 btrfs_end_transaction(trans, root);
8788 break;
8789 }
8790
8791 if (own_trans)
8792 btrfs_end_transaction(trans, root);
8793 }
8794 return ret;
8795 }
8796
8797 int btrfs_prealloc_file_range(struct inode *inode, int mode,
8798 u64 start, u64 num_bytes, u64 min_size,
8799 loff_t actual_len, u64 *alloc_hint)
8800 {
8801 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
8802 min_size, actual_len, alloc_hint,
8803 NULL);
8804 }
8805
8806 int btrfs_prealloc_file_range_trans(struct inode *inode,
8807 struct btrfs_trans_handle *trans, int mode,
8808 u64 start, u64 num_bytes, u64 min_size,
8809 loff_t actual_len, u64 *alloc_hint)
8810 {
8811 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
8812 min_size, actual_len, alloc_hint, trans);
8813 }
8814
8815 static int btrfs_set_page_dirty(struct page *page)
8816 {
8817 return __set_page_dirty_nobuffers(page);
8818 }
8819
8820 static int btrfs_permission(struct inode *inode, int mask)
8821 {
8822 struct btrfs_root *root = BTRFS_I(inode)->root;
8823 umode_t mode = inode->i_mode;
8824
8825 if (mask & MAY_WRITE &&
8826 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
8827 if (btrfs_root_readonly(root))
8828 return -EROFS;
8829 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
8830 return -EACCES;
8831 }
8832 return generic_permission(inode, mask);
8833 }
8834
8835 static const struct inode_operations btrfs_dir_inode_operations = {
8836 .getattr = btrfs_getattr,
8837 .lookup = btrfs_lookup,
8838 .create = btrfs_create,
8839 .unlink = btrfs_unlink,
8840 .link = btrfs_link,
8841 .mkdir = btrfs_mkdir,
8842 .rmdir = btrfs_rmdir,
8843 .rename = btrfs_rename,
8844 .symlink = btrfs_symlink,
8845 .setattr = btrfs_setattr,
8846 .mknod = btrfs_mknod,
8847 .setxattr = btrfs_setxattr,
8848 .getxattr = btrfs_getxattr,
8849 .listxattr = btrfs_listxattr,
8850 .removexattr = btrfs_removexattr,
8851 .permission = btrfs_permission,
8852 .get_acl = btrfs_get_acl,
8853 .set_acl = btrfs_set_acl,
8854 .update_time = btrfs_update_time,
8855 };
8856 static const struct inode_operations btrfs_dir_ro_inode_operations = {
8857 .lookup = btrfs_lookup,
8858 .permission = btrfs_permission,
8859 .get_acl = btrfs_get_acl,
8860 .set_acl = btrfs_set_acl,
8861 .update_time = btrfs_update_time,
8862 };
8863
8864 static const struct file_operations btrfs_dir_file_operations = {
8865 .llseek = generic_file_llseek,
8866 .read = generic_read_dir,
8867 .iterate = btrfs_real_readdir,
8868 .unlocked_ioctl = btrfs_ioctl,
8869 #ifdef CONFIG_COMPAT
8870 .compat_ioctl = btrfs_ioctl,
8871 #endif
8872 .release = btrfs_release_file,
8873 .fsync = btrfs_sync_file,
8874 };
8875
8876 static struct extent_io_ops btrfs_extent_io_ops = {
8877 .fill_delalloc = run_delalloc_range,
8878 .submit_bio_hook = btrfs_submit_bio_hook,
8879 .merge_bio_hook = btrfs_merge_bio_hook,
8880 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
8881 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
8882 .writepage_start_hook = btrfs_writepage_start_hook,
8883 .set_bit_hook = btrfs_set_bit_hook,
8884 .clear_bit_hook = btrfs_clear_bit_hook,
8885 .merge_extent_hook = btrfs_merge_extent_hook,
8886 .split_extent_hook = btrfs_split_extent_hook,
8887 };
8888
8889 /*
8890 * btrfs doesn't support the bmap operation because swapfiles
8891 * use bmap to make a mapping of extents in the file. They assume
8892 * these extents won't change over the life of the file and they
8893 * use the bmap result to do IO directly to the drive.
8894 *
8895 * the btrfs bmap call would return logical addresses that aren't
8896 * suitable for IO and they also will change frequently as COW
8897 * operations happen. So, swapfile + btrfs == corruption.
8898 *
8899 * For now we're avoiding this by dropping bmap.
8900 */
8901 static const struct address_space_operations btrfs_aops = {
8902 .readpage = btrfs_readpage,
8903 .writepage = btrfs_writepage,
8904 .writepages = btrfs_writepages,
8905 .readpages = btrfs_readpages,
8906 .direct_IO = btrfs_direct_IO,
8907 .invalidatepage = btrfs_invalidatepage,
8908 .releasepage = btrfs_releasepage,
8909 .set_page_dirty = btrfs_set_page_dirty,
8910 .error_remove_page = generic_error_remove_page,
8911 };
8912
8913 static const struct address_space_operations btrfs_symlink_aops = {
8914 .readpage = btrfs_readpage,
8915 .writepage = btrfs_writepage,
8916 .invalidatepage = btrfs_invalidatepage,
8917 .releasepage = btrfs_releasepage,
8918 };
8919
8920 static const struct inode_operations btrfs_file_inode_operations = {
8921 .getattr = btrfs_getattr,
8922 .setattr = btrfs_setattr,
8923 .setxattr = btrfs_setxattr,
8924 .getxattr = btrfs_getxattr,
8925 .listxattr = btrfs_listxattr,
8926 .removexattr = btrfs_removexattr,
8927 .permission = btrfs_permission,
8928 .fiemap = btrfs_fiemap,
8929 .get_acl = btrfs_get_acl,
8930 .set_acl = btrfs_set_acl,
8931 .update_time = btrfs_update_time,
8932 };
8933 static const struct inode_operations btrfs_special_inode_operations = {
8934 .getattr = btrfs_getattr,
8935 .setattr = btrfs_setattr,
8936 .permission = btrfs_permission,
8937 .setxattr = btrfs_setxattr,
8938 .getxattr = btrfs_getxattr,
8939 .listxattr = btrfs_listxattr,
8940 .removexattr = btrfs_removexattr,
8941 .get_acl = btrfs_get_acl,
8942 .set_acl = btrfs_set_acl,
8943 .update_time = btrfs_update_time,
8944 };
8945 static const struct inode_operations btrfs_symlink_inode_operations = {
8946 .readlink = generic_readlink,
8947 .follow_link = page_follow_link_light,
8948 .put_link = page_put_link,
8949 .getattr = btrfs_getattr,
8950 .setattr = btrfs_setattr,
8951 .permission = btrfs_permission,
8952 .setxattr = btrfs_setxattr,
8953 .getxattr = btrfs_getxattr,
8954 .listxattr = btrfs_listxattr,
8955 .removexattr = btrfs_removexattr,
8956 .update_time = btrfs_update_time,
8957 };
8958
8959 const struct dentry_operations btrfs_dentry_operations = {
8960 .d_delete = btrfs_dentry_delete,
8961 .d_release = btrfs_dentry_release,
8962 };
Linux with added FPC-III support