projects / deliverable / linux.git / blob
? search:


24dfa27a4f76f03bf35dc3292cb7f7738a10baf9
[deliverable/linux.git] / fs / btrfs / inode.c
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/pagemap.h>
25 #include <linux/highmem.h>
26 #include <linux/time.h>
27 #include <linux/init.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mpage.h>
31 #include <linux/swap.h>
32 #include <linux/writeback.h>
33 #include <linux/statfs.h>
34 #include <linux/compat.h>
35 #include <linux/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 /*
398 * skip compression for a small file range(<=blocksize) that
399 * isn't an inline extent, since it dosen't save disk space at all.
400 */
401 if ((end - start + 1) <= blocksize &&
402 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
403 goto cleanup_and_bail_uncompressed;
404
405 actual_end = min_t(u64, isize, end + 1);
406 again:
407 will_compress = 0;
408 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
409 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
410
411 /*
412 * we don't want to send crud past the end of i_size through
413 * compression, that's just a waste of CPU time. So, if the
414 * end of the file is before the start of our current
415 * requested range of bytes, we bail out to the uncompressed
416 * cleanup code that can deal with all of this.
417 *
418 * It isn't really the fastest way to fix things, but this is a
419 * very uncommon corner.
420 */
421 if (actual_end <= start)
422 goto cleanup_and_bail_uncompressed;
423
424 total_compressed = actual_end - start;
425
426 /* we want to make sure that amount of ram required to uncompress
427 * an extent is reasonable, so we limit the total size in ram
428 * of a compressed extent to 128k. This is a crucial number
429 * because it also controls how easily we can spread reads across
430 * cpus for decompression.
431 *
432 * We also want to make sure the amount of IO required to do
433 * a random read is reasonably small, so we limit the size of
434 * a compressed extent to 128k.
435 */
436 total_compressed = min(total_compressed, max_uncompressed);
437 num_bytes = ALIGN(end - start + 1, blocksize);
438 num_bytes = max(blocksize, num_bytes);
439 total_in = 0;
440 ret = 0;
441
442 /*
443 * we do compression for mount -o compress and when the
444 * inode has not been flagged as nocompress. This flag can
445 * change at any time if we discover bad compression ratios.
446 */
447 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) &&
448 (btrfs_test_opt(root, COMPRESS) ||
449 (BTRFS_I(inode)->force_compress) ||
450 (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) {
451 WARN_ON(pages);
452 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
453 if (!pages) {
454 /* just bail out to the uncompressed code */
455 goto cont;
456 }
457
458 if (BTRFS_I(inode)->force_compress)
459 compress_type = BTRFS_I(inode)->force_compress;
460
461 /*
462 * we need to call clear_page_dirty_for_io on each
463 * page in the range. Otherwise applications with the file
464 * mmap'd can wander in and change the page contents while
465 * we are compressing them.
466 *
467 * If the compression fails for any reason, we set the pages
468 * dirty again later on.
469 */
470 extent_range_clear_dirty_for_io(inode, start, end);
471 redirty = 1;
472 ret = btrfs_compress_pages(compress_type,
473 inode->i_mapping, start,
474 total_compressed, pages,
475 nr_pages, &nr_pages_ret,
476 &total_in,
477 &total_compressed,
478 max_compressed);
479
480 if (!ret) {
481 unsigned long offset = total_compressed &
482 (PAGE_CACHE_SIZE - 1);
483 struct page *page = pages[nr_pages_ret - 1];
484 char *kaddr;
485
486 /* zero the tail end of the last page, we might be
487 * sending it down to disk
488 */
489 if (offset) {
490 kaddr = kmap_atomic(page);
491 memset(kaddr + offset, 0,
492 PAGE_CACHE_SIZE - offset);
493 kunmap_atomic(kaddr);
494 }
495 will_compress = 1;
496 }
497 }
498 cont:
499 if (start == 0) {
500 /* lets try to make an inline extent */
501 if (ret || total_in < (actual_end - start)) {
502 /* we didn't compress the entire range, try
503 * to make an uncompressed inline extent.
504 */
505 ret = cow_file_range_inline(root, inode, start, end,
506 0, 0, NULL);
507 } else {
508 /* try making a compressed inline extent */
509 ret = cow_file_range_inline(root, inode, start, end,
510 total_compressed,
511 compress_type, pages);
512 }
513 if (ret <= 0) {
514 unsigned long clear_flags = EXTENT_DELALLOC |
515 EXTENT_DEFRAG;
516 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0;
517
518 /*
519 * inline extent creation worked or returned error,
520 * we don't need to create any more async work items.
521 * Unlock and free up our temp pages.
522 */
523 extent_clear_unlock_delalloc(inode, start, end, NULL,
524 clear_flags, PAGE_UNLOCK |
525 PAGE_CLEAR_DIRTY |
526 PAGE_SET_WRITEBACK |
527 PAGE_END_WRITEBACK);
528 goto free_pages_out;
529 }
530 }
531
532 if (will_compress) {
533 /*
534 * we aren't doing an inline extent round the compressed size
535 * up to a block size boundary so the allocator does sane
536 * things
537 */
538 total_compressed = ALIGN(total_compressed, blocksize);
539
540 /*
541 * one last check to make sure the compression is really a
542 * win, compare the page count read with the blocks on disk
543 */
544 total_in = ALIGN(total_in, PAGE_CACHE_SIZE);
545 if (total_compressed >= total_in) {
546 will_compress = 0;
547 } else {
548 num_bytes = total_in;
549 }
550 }
551 if (!will_compress && pages) {
552 /*
553 * the compression code ran but failed to make things smaller,
554 * free any pages it allocated and our page pointer array
555 */
556 for (i = 0; i < nr_pages_ret; i++) {
557 WARN_ON(pages[i]->mapping);
558 page_cache_release(pages[i]);
559 }
560 kfree(pages);
561 pages = NULL;
562 total_compressed = 0;
563 nr_pages_ret = 0;
564
565 /* flag the file so we don't compress in the future */
566 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
567 !(BTRFS_I(inode)->force_compress)) {
568 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
569 }
570 }
571 if (will_compress) {
572 *num_added += 1;
573
574 /* the async work queues will take care of doing actual
575 * allocation on disk for these compressed pages,
576 * and will submit them to the elevator.
577 */
578 add_async_extent(async_cow, start, num_bytes,
579 total_compressed, pages, nr_pages_ret,
580 compress_type);
581
582 if (start + num_bytes < end) {
583 start += num_bytes;
584 pages = NULL;
585 cond_resched();
586 goto again;
587 }
588 } else {
589 cleanup_and_bail_uncompressed:
590 /*
591 * No compression, but we still need to write the pages in
592 * the file we've been given so far. redirty the locked
593 * page if it corresponds to our extent and set things up
594 * for the async work queue to run cow_file_range to do
595 * the normal delalloc dance
596 */
597 if (page_offset(locked_page) >= start &&
598 page_offset(locked_page) <= end) {
599 __set_page_dirty_nobuffers(locked_page);
600 /* unlocked later on in the async handlers */
601 }
602 if (redirty)
603 extent_range_redirty_for_io(inode, start, end);
604 add_async_extent(async_cow, start, end - start + 1,
605 0, NULL, 0, BTRFS_COMPRESS_NONE);
606 *num_added += 1;
607 }
608
609 out:
610 return ret;
611
612 free_pages_out:
613 for (i = 0; i < nr_pages_ret; i++) {
614 WARN_ON(pages[i]->mapping);
615 page_cache_release(pages[i]);
616 }
617 kfree(pages);
618
619 goto out;
620 }
621
622 /*
623 * phase two of compressed writeback. This is the ordered portion
624 * of the code, which only gets called in the order the work was
625 * queued. We walk all the async extents created by compress_file_range
626 * and send them down to the disk.
627 */
628 static noinline int submit_compressed_extents(struct inode *inode,
629 struct async_cow *async_cow)
630 {
631 struct async_extent *async_extent;
632 u64 alloc_hint = 0;
633 struct btrfs_key ins;
634 struct extent_map *em;
635 struct btrfs_root *root = BTRFS_I(inode)->root;
636 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
637 struct extent_io_tree *io_tree;
638 int ret = 0;
639
640 if (list_empty(&async_cow->extents))
641 return 0;
642
643 again:
644 while (!list_empty(&async_cow->extents)) {
645 async_extent = list_entry(async_cow->extents.next,
646 struct async_extent, list);
647 list_del(&async_extent->list);
648
649 io_tree = &BTRFS_I(inode)->io_tree;
650
651 retry:
652 /* did the compression code fall back to uncompressed IO? */
653 if (!async_extent->pages) {
654 int page_started = 0;
655 unsigned long nr_written = 0;
656
657 lock_extent(io_tree, async_extent->start,
658 async_extent->start +
659 async_extent->ram_size - 1);
660
661 /* allocate blocks */
662 ret = cow_file_range(inode, async_cow->locked_page,
663 async_extent->start,
664 async_extent->start +
665 async_extent->ram_size - 1,
666 &page_started, &nr_written, 0);
667
668 /* JDM XXX */
669
670 /*
671 * if page_started, cow_file_range inserted an
672 * inline extent and took care of all the unlocking
673 * and IO for us. Otherwise, we need to submit
674 * all those pages down to the drive.
675 */
676 if (!page_started && !ret)
677 extent_write_locked_range(io_tree,
678 inode, async_extent->start,
679 async_extent->start +
680 async_extent->ram_size - 1,
681 btrfs_get_extent,
682 WB_SYNC_ALL);
683 else if (ret)
684 unlock_page(async_cow->locked_page);
685 kfree(async_extent);
686 cond_resched();
687 continue;
688 }
689
690 lock_extent(io_tree, async_extent->start,
691 async_extent->start + async_extent->ram_size - 1);
692
693 ret = btrfs_reserve_extent(root,
694 async_extent->compressed_size,
695 async_extent->compressed_size,
696 0, alloc_hint, &ins, 1);
697 if (ret) {
698 int i;
699
700 for (i = 0; i < async_extent->nr_pages; i++) {
701 WARN_ON(async_extent->pages[i]->mapping);
702 page_cache_release(async_extent->pages[i]);
703 }
704 kfree(async_extent->pages);
705 async_extent->nr_pages = 0;
706 async_extent->pages = NULL;
707
708 if (ret == -ENOSPC) {
709 unlock_extent(io_tree, async_extent->start,
710 async_extent->start +
711 async_extent->ram_size - 1);
712 goto retry;
713 }
714 goto out_free;
715 }
716
717 /*
718 * here we're doing allocation and writeback of the
719 * compressed pages
720 */
721 btrfs_drop_extent_cache(inode, async_extent->start,
722 async_extent->start +
723 async_extent->ram_size - 1, 0);
724
725 em = alloc_extent_map();
726 if (!em) {
727 ret = -ENOMEM;
728 goto out_free_reserve;
729 }
730 em->start = async_extent->start;
731 em->len = async_extent->ram_size;
732 em->orig_start = em->start;
733 em->mod_start = em->start;
734 em->mod_len = em->len;
735
736 em->block_start = ins.objectid;
737 em->block_len = ins.offset;
738 em->orig_block_len = ins.offset;
739 em->ram_bytes = async_extent->ram_size;
740 em->bdev = root->fs_info->fs_devices->latest_bdev;
741 em->compress_type = async_extent->compress_type;
742 set_bit(EXTENT_FLAG_PINNED, &em->flags);
743 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
744 em->generation = -1;
745
746 while (1) {
747 write_lock(&em_tree->lock);
748 ret = add_extent_mapping(em_tree, em, 1);
749 write_unlock(&em_tree->lock);
750 if (ret != -EEXIST) {
751 free_extent_map(em);
752 break;
753 }
754 btrfs_drop_extent_cache(inode, async_extent->start,
755 async_extent->start +
756 async_extent->ram_size - 1, 0);
757 }
758
759 if (ret)
760 goto out_free_reserve;
761
762 ret = btrfs_add_ordered_extent_compress(inode,
763 async_extent->start,
764 ins.objectid,
765 async_extent->ram_size,
766 ins.offset,
767 BTRFS_ORDERED_COMPRESSED,
768 async_extent->compress_type);
769 if (ret)
770 goto out_free_reserve;
771
772 /*
773 * clear dirty, set writeback and unlock the pages.
774 */
775 extent_clear_unlock_delalloc(inode, async_extent->start,
776 async_extent->start +
777 async_extent->ram_size - 1,
778 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
779 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
780 PAGE_SET_WRITEBACK);
781 ret = btrfs_submit_compressed_write(inode,
782 async_extent->start,
783 async_extent->ram_size,
784 ins.objectid,
785 ins.offset, async_extent->pages,
786 async_extent->nr_pages);
787 alloc_hint = ins.objectid + ins.offset;
788 kfree(async_extent);
789 if (ret)
790 goto out;
791 cond_resched();
792 }
793 ret = 0;
794 out:
795 return ret;
796 out_free_reserve:
797 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
798 out_free:
799 extent_clear_unlock_delalloc(inode, async_extent->start,
800 async_extent->start +
801 async_extent->ram_size - 1,
802 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
803 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
804 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
805 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
806 kfree(async_extent);
807 goto again;
808 }
809
810 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
811 u64 num_bytes)
812 {
813 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
814 struct extent_map *em;
815 u64 alloc_hint = 0;
816
817 read_lock(&em_tree->lock);
818 em = search_extent_mapping(em_tree, start, num_bytes);
819 if (em) {
820 /*
821 * if block start isn't an actual block number then find the
822 * first block in this inode and use that as a hint. If that
823 * block is also bogus then just don't worry about it.
824 */
825 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
826 free_extent_map(em);
827 em = search_extent_mapping(em_tree, 0, 0);
828 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
829 alloc_hint = em->block_start;
830 if (em)
831 free_extent_map(em);
832 } else {
833 alloc_hint = em->block_start;
834 free_extent_map(em);
835 }
836 }
837 read_unlock(&em_tree->lock);
838
839 return alloc_hint;
840 }
841
842 /*
843 * when extent_io.c finds a delayed allocation range in the file,
844 * the call backs end up in this code. The basic idea is to
845 * allocate extents on disk for the range, and create ordered data structs
846 * in ram to track those extents.
847 *
848 * locked_page is the page that writepage had locked already. We use
849 * it to make sure we don't do extra locks or unlocks.
850 *
851 * *page_started is set to one if we unlock locked_page and do everything
852 * required to start IO on it. It may be clean and already done with
853 * IO when we return.
854 */
855 static noinline int cow_file_range(struct inode *inode,
856 struct page *locked_page,
857 u64 start, u64 end, int *page_started,
858 unsigned long *nr_written,
859 int unlock)
860 {
861 struct btrfs_root *root = BTRFS_I(inode)->root;
862 u64 alloc_hint = 0;
863 u64 num_bytes;
864 unsigned long ram_size;
865 u64 disk_num_bytes;
866 u64 cur_alloc_size;
867 u64 blocksize = root->sectorsize;
868 struct btrfs_key ins;
869 struct extent_map *em;
870 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
871 int ret = 0;
872
873 if (btrfs_is_free_space_inode(inode)) {
874 WARN_ON_ONCE(1);
875 ret = -EINVAL;
876 goto out_unlock;
877 }
878
879 num_bytes = ALIGN(end - start + 1, blocksize);
880 num_bytes = max(blocksize, num_bytes);
881 disk_num_bytes = num_bytes;
882
883 /* if this is a small write inside eof, kick off defrag */
884 if (num_bytes < 64 * 1024 &&
885 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
886 btrfs_add_inode_defrag(NULL, inode);
887
888 if (start == 0) {
889 /* lets try to make an inline extent */
890 ret = cow_file_range_inline(root, inode, start, end, 0, 0,
891 NULL);
892 if (ret == 0) {
893 extent_clear_unlock_delalloc(inode, start, end, NULL,
894 EXTENT_LOCKED | EXTENT_DELALLOC |
895 EXTENT_DEFRAG, PAGE_UNLOCK |
896 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
897 PAGE_END_WRITEBACK);
898
899 *nr_written = *nr_written +
900 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
901 *page_started = 1;
902 goto out;
903 } else if (ret < 0) {
904 goto out_unlock;
905 }
906 }
907
908 BUG_ON(disk_num_bytes >
909 btrfs_super_total_bytes(root->fs_info->super_copy));
910
911 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
912 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
913
914 while (disk_num_bytes > 0) {
915 unsigned long op;
916
917 cur_alloc_size = disk_num_bytes;
918 ret = btrfs_reserve_extent(root, cur_alloc_size,
919 root->sectorsize, 0, alloc_hint,
920 &ins, 1);
921 if (ret < 0)
922 goto out_unlock;
923
924 em = alloc_extent_map();
925 if (!em) {
926 ret = -ENOMEM;
927 goto out_reserve;
928 }
929 em->start = start;
930 em->orig_start = em->start;
931 ram_size = ins.offset;
932 em->len = ins.offset;
933 em->mod_start = em->start;
934 em->mod_len = em->len;
935
936 em->block_start = ins.objectid;
937 em->block_len = ins.offset;
938 em->orig_block_len = ins.offset;
939 em->ram_bytes = ram_size;
940 em->bdev = root->fs_info->fs_devices->latest_bdev;
941 set_bit(EXTENT_FLAG_PINNED, &em->flags);
942 em->generation = -1;
943
944 while (1) {
945 write_lock(&em_tree->lock);
946 ret = add_extent_mapping(em_tree, em, 1);
947 write_unlock(&em_tree->lock);
948 if (ret != -EEXIST) {
949 free_extent_map(em);
950 break;
951 }
952 btrfs_drop_extent_cache(inode, start,
953 start + ram_size - 1, 0);
954 }
955 if (ret)
956 goto out_reserve;
957
958 cur_alloc_size = ins.offset;
959 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
960 ram_size, cur_alloc_size, 0);
961 if (ret)
962 goto out_reserve;
963
964 if (root->root_key.objectid ==
965 BTRFS_DATA_RELOC_TREE_OBJECTID) {
966 ret = btrfs_reloc_clone_csums(inode, start,
967 cur_alloc_size);
968 if (ret)
969 goto out_reserve;
970 }
971
972 if (disk_num_bytes < cur_alloc_size)
973 break;
974
975 /* we're not doing compressed IO, don't unlock the first
976 * page (which the caller expects to stay locked), don't
977 * clear any dirty bits and don't set any writeback bits
978 *
979 * Do set the Private2 bit so we know this page was properly
980 * setup for writepage
981 */
982 op = unlock ? PAGE_UNLOCK : 0;
983 op |= PAGE_SET_PRIVATE2;
984
985 extent_clear_unlock_delalloc(inode, start,
986 start + ram_size - 1, locked_page,
987 EXTENT_LOCKED | EXTENT_DELALLOC,
988 op);
989 disk_num_bytes -= cur_alloc_size;
990 num_bytes -= cur_alloc_size;
991 alloc_hint = ins.objectid + ins.offset;
992 start += cur_alloc_size;
993 }
994 out:
995 return ret;
996
997 out_reserve:
998 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
999 out_unlock:
1000 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1001 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
1002 EXTENT_DELALLOC | EXTENT_DEFRAG,
1003 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
1004 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
1005 goto out;
1006 }
1007
1008 /*
1009 * work queue call back to started compression on a file and pages
1010 */
1011 static noinline void async_cow_start(struct btrfs_work *work)
1012 {
1013 struct async_cow *async_cow;
1014 int num_added = 0;
1015 async_cow = container_of(work, struct async_cow, work);
1016
1017 compress_file_range(async_cow->inode, async_cow->locked_page,
1018 async_cow->start, async_cow->end, async_cow,
1019 &num_added);
1020 if (num_added == 0) {
1021 btrfs_add_delayed_iput(async_cow->inode);
1022 async_cow->inode = NULL;
1023 }
1024 }
1025
1026 /*
1027 * work queue call back to submit previously compressed pages
1028 */
1029 static noinline void async_cow_submit(struct btrfs_work *work)
1030 {
1031 struct async_cow *async_cow;
1032 struct btrfs_root *root;
1033 unsigned long nr_pages;
1034
1035 async_cow = container_of(work, struct async_cow, work);
1036
1037 root = async_cow->root;
1038 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
1039 PAGE_CACHE_SHIFT;
1040
1041 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1042 5 * 1024 * 1024 &&
1043 waitqueue_active(&root->fs_info->async_submit_wait))
1044 wake_up(&root->fs_info->async_submit_wait);
1045
1046 if (async_cow->inode)
1047 submit_compressed_extents(async_cow->inode, async_cow);
1048 }
1049
1050 static noinline void async_cow_free(struct btrfs_work *work)
1051 {
1052 struct async_cow *async_cow;
1053 async_cow = container_of(work, struct async_cow, work);
1054 if (async_cow->inode)
1055 btrfs_add_delayed_iput(async_cow->inode);
1056 kfree(async_cow);
1057 }
1058
1059 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1060 u64 start, u64 end, int *page_started,
1061 unsigned long *nr_written)
1062 {
1063 struct async_cow *async_cow;
1064 struct btrfs_root *root = BTRFS_I(inode)->root;
1065 unsigned long nr_pages;
1066 u64 cur_end;
1067 int limit = 10 * 1024 * 1024;
1068
1069 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1070 1, 0, NULL, GFP_NOFS);
1071 while (start < end) {
1072 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1073 BUG_ON(!async_cow); /* -ENOMEM */
1074 async_cow->inode = igrab(inode);
1075 async_cow->root = root;
1076 async_cow->locked_page = locked_page;
1077 async_cow->start = start;
1078
1079 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
1080 cur_end = end;
1081 else
1082 cur_end = min(end, start + 512 * 1024 - 1);
1083
1084 async_cow->end = cur_end;
1085 INIT_LIST_HEAD(&async_cow->extents);
1086
1087 btrfs_init_work(&async_cow->work, async_cow_start,
1088 async_cow_submit, async_cow_free);
1089
1090 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
1091 PAGE_CACHE_SHIFT;
1092 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1093
1094 btrfs_queue_work(root->fs_info->delalloc_workers,
1095 &async_cow->work);
1096
1097 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1098 wait_event(root->fs_info->async_submit_wait,
1099 (atomic_read(&root->fs_info->async_delalloc_pages) <
1100 limit));
1101 }
1102
1103 while (atomic_read(&root->fs_info->async_submit_draining) &&
1104 atomic_read(&root->fs_info->async_delalloc_pages)) {
1105 wait_event(root->fs_info->async_submit_wait,
1106 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1107 0));
1108 }
1109
1110 *nr_written += nr_pages;
1111 start = cur_end + 1;
1112 }
1113 *page_started = 1;
1114 return 0;
1115 }
1116
1117 static noinline int csum_exist_in_range(struct btrfs_root *root,
1118 u64 bytenr, u64 num_bytes)
1119 {
1120 int ret;
1121 struct btrfs_ordered_sum *sums;
1122 LIST_HEAD(list);
1123
1124 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1125 bytenr + num_bytes - 1, &list, 0);
1126 if (ret == 0 && list_empty(&list))
1127 return 0;
1128
1129 while (!list_empty(&list)) {
1130 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1131 list_del(&sums->list);
1132 kfree(sums);
1133 }
1134 return 1;
1135 }
1136
1137 /*
1138 * when nowcow writeback call back. This checks for snapshots or COW copies
1139 * of the extents that exist in the file, and COWs the file as required.
1140 *
1141 * If no cow copies or snapshots exist, we write directly to the existing
1142 * blocks on disk
1143 */
1144 static noinline int run_delalloc_nocow(struct inode *inode,
1145 struct page *locked_page,
1146 u64 start, u64 end, int *page_started, int force,
1147 unsigned long *nr_written)
1148 {
1149 struct btrfs_root *root = BTRFS_I(inode)->root;
1150 struct btrfs_trans_handle *trans;
1151 struct extent_buffer *leaf;
1152 struct btrfs_path *path;
1153 struct btrfs_file_extent_item *fi;
1154 struct btrfs_key found_key;
1155 u64 cow_start;
1156 u64 cur_offset;
1157 u64 extent_end;
1158 u64 extent_offset;
1159 u64 disk_bytenr;
1160 u64 num_bytes;
1161 u64 disk_num_bytes;
1162 u64 ram_bytes;
1163 int extent_type;
1164 int ret, err;
1165 int type;
1166 int nocow;
1167 int check_prev = 1;
1168 bool nolock;
1169 u64 ino = btrfs_ino(inode);
1170
1171 path = btrfs_alloc_path();
1172 if (!path) {
1173 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1174 EXTENT_LOCKED | EXTENT_DELALLOC |
1175 EXTENT_DO_ACCOUNTING |
1176 EXTENT_DEFRAG, PAGE_UNLOCK |
1177 PAGE_CLEAR_DIRTY |
1178 PAGE_SET_WRITEBACK |
1179 PAGE_END_WRITEBACK);
1180 return -ENOMEM;
1181 }
1182
1183 nolock = btrfs_is_free_space_inode(inode);
1184
1185 if (nolock)
1186 trans = btrfs_join_transaction_nolock(root);
1187 else
1188 trans = btrfs_join_transaction(root);
1189
1190 if (IS_ERR(trans)) {
1191 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1192 EXTENT_LOCKED | EXTENT_DELALLOC |
1193 EXTENT_DO_ACCOUNTING |
1194 EXTENT_DEFRAG, PAGE_UNLOCK |
1195 PAGE_CLEAR_DIRTY |
1196 PAGE_SET_WRITEBACK |
1197 PAGE_END_WRITEBACK);
1198 btrfs_free_path(path);
1199 return PTR_ERR(trans);
1200 }
1201
1202 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1203
1204 cow_start = (u64)-1;
1205 cur_offset = start;
1206 while (1) {
1207 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1208 cur_offset, 0);
1209 if (ret < 0)
1210 goto error;
1211 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1212 leaf = path->nodes[0];
1213 btrfs_item_key_to_cpu(leaf, &found_key,
1214 path->slots[0] - 1);
1215 if (found_key.objectid == ino &&
1216 found_key.type == BTRFS_EXTENT_DATA_KEY)
1217 path->slots[0]--;
1218 }
1219 check_prev = 0;
1220 next_slot:
1221 leaf = path->nodes[0];
1222 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1223 ret = btrfs_next_leaf(root, path);
1224 if (ret < 0)
1225 goto error;
1226 if (ret > 0)
1227 break;
1228 leaf = path->nodes[0];
1229 }
1230
1231 nocow = 0;
1232 disk_bytenr = 0;
1233 num_bytes = 0;
1234 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1235
1236 if (found_key.objectid > ino ||
1237 found_key.type > BTRFS_EXTENT_DATA_KEY ||
1238 found_key.offset > end)
1239 break;
1240
1241 if (found_key.offset > cur_offset) {
1242 extent_end = found_key.offset;
1243 extent_type = 0;
1244 goto out_check;
1245 }
1246
1247 fi = btrfs_item_ptr(leaf, path->slots[0],
1248 struct btrfs_file_extent_item);
1249 extent_type = btrfs_file_extent_type(leaf, fi);
1250
1251 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1252 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1253 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1254 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1255 extent_offset = btrfs_file_extent_offset(leaf, fi);
1256 extent_end = found_key.offset +
1257 btrfs_file_extent_num_bytes(leaf, fi);
1258 disk_num_bytes =
1259 btrfs_file_extent_disk_num_bytes(leaf, fi);
1260 if (extent_end <= start) {
1261 path->slots[0]++;
1262 goto next_slot;
1263 }
1264 if (disk_bytenr == 0)
1265 goto out_check;
1266 if (btrfs_file_extent_compression(leaf, fi) ||
1267 btrfs_file_extent_encryption(leaf, fi) ||
1268 btrfs_file_extent_other_encoding(leaf, fi))
1269 goto out_check;
1270 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1271 goto out_check;
1272 if (btrfs_extent_readonly(root, disk_bytenr))
1273 goto out_check;
1274 if (btrfs_cross_ref_exist(trans, root, ino,
1275 found_key.offset -
1276 extent_offset, disk_bytenr))
1277 goto out_check;
1278 disk_bytenr += extent_offset;
1279 disk_bytenr += cur_offset - found_key.offset;
1280 num_bytes = min(end + 1, extent_end) - cur_offset;
1281 /*
1282 * if there are pending snapshots for this root,
1283 * we fall into common COW way.
1284 */
1285 if (!nolock) {
1286 err = btrfs_start_nocow_write(root);
1287 if (!err)
1288 goto out_check;
1289 }
1290 /*
1291 * force cow if csum exists in the range.
1292 * this ensure that csum for a given extent are
1293 * either valid or do not exist.
1294 */
1295 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1296 goto out_check;
1297 nocow = 1;
1298 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1299 extent_end = found_key.offset +
1300 btrfs_file_extent_inline_len(leaf,
1301 path->slots[0], fi);
1302 extent_end = ALIGN(extent_end, root->sectorsize);
1303 } else {
1304 BUG_ON(1);
1305 }
1306 out_check:
1307 if (extent_end <= start) {
1308 path->slots[0]++;
1309 if (!nolock && nocow)
1310 btrfs_end_nocow_write(root);
1311 goto next_slot;
1312 }
1313 if (!nocow) {
1314 if (cow_start == (u64)-1)
1315 cow_start = cur_offset;
1316 cur_offset = extent_end;
1317 if (cur_offset > end)
1318 break;
1319 path->slots[0]++;
1320 goto next_slot;
1321 }
1322
1323 btrfs_release_path(path);
1324 if (cow_start != (u64)-1) {
1325 ret = cow_file_range(inode, locked_page,
1326 cow_start, found_key.offset - 1,
1327 page_started, nr_written, 1);
1328 if (ret) {
1329 if (!nolock && nocow)
1330 btrfs_end_nocow_write(root);
1331 goto error;
1332 }
1333 cow_start = (u64)-1;
1334 }
1335
1336 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1337 struct extent_map *em;
1338 struct extent_map_tree *em_tree;
1339 em_tree = &BTRFS_I(inode)->extent_tree;
1340 em = alloc_extent_map();
1341 BUG_ON(!em); /* -ENOMEM */
1342 em->start = cur_offset;
1343 em->orig_start = found_key.offset - extent_offset;
1344 em->len = num_bytes;
1345 em->block_len = num_bytes;
1346 em->block_start = disk_bytenr;
1347 em->orig_block_len = disk_num_bytes;
1348 em->ram_bytes = ram_bytes;
1349 em->bdev = root->fs_info->fs_devices->latest_bdev;
1350 em->mod_start = em->start;
1351 em->mod_len = em->len;
1352 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1353 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1354 em->generation = -1;
1355 while (1) {
1356 write_lock(&em_tree->lock);
1357 ret = add_extent_mapping(em_tree, em, 1);
1358 write_unlock(&em_tree->lock);
1359 if (ret != -EEXIST) {
1360 free_extent_map(em);
1361 break;
1362 }
1363 btrfs_drop_extent_cache(inode, em->start,
1364 em->start + em->len - 1, 0);
1365 }
1366 type = BTRFS_ORDERED_PREALLOC;
1367 } else {
1368 type = BTRFS_ORDERED_NOCOW;
1369 }
1370
1371 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1372 num_bytes, num_bytes, type);
1373 BUG_ON(ret); /* -ENOMEM */
1374
1375 if (root->root_key.objectid ==
1376 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1377 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1378 num_bytes);
1379 if (ret) {
1380 if (!nolock && nocow)
1381 btrfs_end_nocow_write(root);
1382 goto error;
1383 }
1384 }
1385
1386 extent_clear_unlock_delalloc(inode, cur_offset,
1387 cur_offset + num_bytes - 1,
1388 locked_page, EXTENT_LOCKED |
1389 EXTENT_DELALLOC, PAGE_UNLOCK |
1390 PAGE_SET_PRIVATE2);
1391 if (!nolock && nocow)
1392 btrfs_end_nocow_write(root);
1393 cur_offset = extent_end;
1394 if (cur_offset > end)
1395 break;
1396 }
1397 btrfs_release_path(path);
1398
1399 if (cur_offset <= end && cow_start == (u64)-1) {
1400 cow_start = cur_offset;
1401 cur_offset = end;
1402 }
1403
1404 if (cow_start != (u64)-1) {
1405 ret = cow_file_range(inode, locked_page, cow_start, end,
1406 page_started, nr_written, 1);
1407 if (ret)
1408 goto error;
1409 }
1410
1411 error:
1412 err = btrfs_end_transaction(trans, root);
1413 if (!ret)
1414 ret = err;
1415
1416 if (ret && cur_offset < end)
1417 extent_clear_unlock_delalloc(inode, cur_offset, end,
1418 locked_page, EXTENT_LOCKED |
1419 EXTENT_DELALLOC | EXTENT_DEFRAG |
1420 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1421 PAGE_CLEAR_DIRTY |
1422 PAGE_SET_WRITEBACK |
1423 PAGE_END_WRITEBACK);
1424 btrfs_free_path(path);
1425 return ret;
1426 }
1427
1428 /*
1429 * extent_io.c call back to do delayed allocation processing
1430 */
1431 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1432 u64 start, u64 end, int *page_started,
1433 unsigned long *nr_written)
1434 {
1435 int ret;
1436 struct btrfs_root *root = BTRFS_I(inode)->root;
1437
1438 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) {
1439 ret = run_delalloc_nocow(inode, locked_page, start, end,
1440 page_started, 1, nr_written);
1441 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC) {
1442 ret = run_delalloc_nocow(inode, locked_page, start, end,
1443 page_started, 0, nr_written);
1444 } else if (!btrfs_test_opt(root, COMPRESS) &&
1445 !(BTRFS_I(inode)->force_compress) &&
1446 !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS)) {
1447 ret = cow_file_range(inode, locked_page, start, end,
1448 page_started, nr_written, 1);
1449 } else {
1450 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1451 &BTRFS_I(inode)->runtime_flags);
1452 ret = cow_file_range_async(inode, locked_page, start, end,
1453 page_started, nr_written);
1454 }
1455 return ret;
1456 }
1457
1458 static void btrfs_split_extent_hook(struct inode *inode,
1459 struct extent_state *orig, u64 split)
1460 {
1461 /* not delalloc, ignore it */
1462 if (!(orig->state & EXTENT_DELALLOC))
1463 return;
1464
1465 spin_lock(&BTRFS_I(inode)->lock);
1466 BTRFS_I(inode)->outstanding_extents++;
1467 spin_unlock(&BTRFS_I(inode)->lock);
1468 }
1469
1470 /*
1471 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1472 * extents so we can keep track of new extents that are just merged onto old
1473 * extents, such as when we are doing sequential writes, so we can properly
1474 * account for the metadata space we'll need.
1475 */
1476 static void btrfs_merge_extent_hook(struct inode *inode,
1477 struct extent_state *new,
1478 struct extent_state *other)
1479 {
1480 /* not delalloc, ignore it */
1481 if (!(other->state & EXTENT_DELALLOC))
1482 return;
1483
1484 spin_lock(&BTRFS_I(inode)->lock);
1485 BTRFS_I(inode)->outstanding_extents--;
1486 spin_unlock(&BTRFS_I(inode)->lock);
1487 }
1488
1489 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1490 struct inode *inode)
1491 {
1492 spin_lock(&root->delalloc_lock);
1493 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1494 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1495 &root->delalloc_inodes);
1496 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1497 &BTRFS_I(inode)->runtime_flags);
1498 root->nr_delalloc_inodes++;
1499 if (root->nr_delalloc_inodes == 1) {
1500 spin_lock(&root->fs_info->delalloc_root_lock);
1501 BUG_ON(!list_empty(&root->delalloc_root));
1502 list_add_tail(&root->delalloc_root,
1503 &root->fs_info->delalloc_roots);
1504 spin_unlock(&root->fs_info->delalloc_root_lock);
1505 }
1506 }
1507 spin_unlock(&root->delalloc_lock);
1508 }
1509
1510 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1511 struct inode *inode)
1512 {
1513 spin_lock(&root->delalloc_lock);
1514 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1515 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1516 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1517 &BTRFS_I(inode)->runtime_flags);
1518 root->nr_delalloc_inodes--;
1519 if (!root->nr_delalloc_inodes) {
1520 spin_lock(&root->fs_info->delalloc_root_lock);
1521 BUG_ON(list_empty(&root->delalloc_root));
1522 list_del_init(&root->delalloc_root);
1523 spin_unlock(&root->fs_info->delalloc_root_lock);
1524 }
1525 }
1526 spin_unlock(&root->delalloc_lock);
1527 }
1528
1529 /*
1530 * extent_io.c set_bit_hook, used to track delayed allocation
1531 * bytes in this file, and to maintain the list of inodes that
1532 * have pending delalloc work to be done.
1533 */
1534 static void btrfs_set_bit_hook(struct inode *inode,
1535 struct extent_state *state, unsigned long *bits)
1536 {
1537
1538 /*
1539 * set_bit and clear bit hooks normally require _irqsave/restore
1540 * but in this case, we are only testing for the DELALLOC
1541 * bit, which is only set or cleared with irqs on
1542 */
1543 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1544 struct btrfs_root *root = BTRFS_I(inode)->root;
1545 u64 len = state->end + 1 - state->start;
1546 bool do_list = !btrfs_is_free_space_inode(inode);
1547
1548 if (*bits & EXTENT_FIRST_DELALLOC) {
1549 *bits &= ~EXTENT_FIRST_DELALLOC;
1550 } else {
1551 spin_lock(&BTRFS_I(inode)->lock);
1552 BTRFS_I(inode)->outstanding_extents++;
1553 spin_unlock(&BTRFS_I(inode)->lock);
1554 }
1555
1556 __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
1557 root->fs_info->delalloc_batch);
1558 spin_lock(&BTRFS_I(inode)->lock);
1559 BTRFS_I(inode)->delalloc_bytes += len;
1560 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1561 &BTRFS_I(inode)->runtime_flags))
1562 btrfs_add_delalloc_inodes(root, inode);
1563 spin_unlock(&BTRFS_I(inode)->lock);
1564 }
1565 }
1566
1567 /*
1568 * extent_io.c clear_bit_hook, see set_bit_hook for why
1569 */
1570 static void btrfs_clear_bit_hook(struct inode *inode,
1571 struct extent_state *state,
1572 unsigned long *bits)
1573 {
1574 /*
1575 * set_bit and clear bit hooks normally require _irqsave/restore
1576 * but in this case, we are only testing for the DELALLOC
1577 * bit, which is only set or cleared with irqs on
1578 */
1579 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1580 struct btrfs_root *root = BTRFS_I(inode)->root;
1581 u64 len = state->end + 1 - state->start;
1582 bool do_list = !btrfs_is_free_space_inode(inode);
1583
1584 if (*bits & EXTENT_FIRST_DELALLOC) {
1585 *bits &= ~EXTENT_FIRST_DELALLOC;
1586 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1587 spin_lock(&BTRFS_I(inode)->lock);
1588 BTRFS_I(inode)->outstanding_extents--;
1589 spin_unlock(&BTRFS_I(inode)->lock);
1590 }
1591
1592 /*
1593 * We don't reserve metadata space for space cache inodes so we
1594 * don't need to call dellalloc_release_metadata if there is an
1595 * error.
1596 */
1597 if (*bits & EXTENT_DO_ACCOUNTING &&
1598 root != root->fs_info->tree_root)
1599 btrfs_delalloc_release_metadata(inode, len);
1600
1601 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1602 && do_list && !(state->state & EXTENT_NORESERVE))
1603 btrfs_free_reserved_data_space(inode, len);
1604
1605 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
1606 root->fs_info->delalloc_batch);
1607 spin_lock(&BTRFS_I(inode)->lock);
1608 BTRFS_I(inode)->delalloc_bytes -= len;
1609 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1610 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1611 &BTRFS_I(inode)->runtime_flags))
1612 btrfs_del_delalloc_inode(root, inode);
1613 spin_unlock(&BTRFS_I(inode)->lock);
1614 }
1615 }
1616
1617 /*
1618 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1619 * we don't create bios that span stripes or chunks
1620 */
1621 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
1622 size_t size, struct bio *bio,
1623 unsigned long bio_flags)
1624 {
1625 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1626 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1627 u64 length = 0;
1628 u64 map_length;
1629 int ret;
1630
1631 if (bio_flags & EXTENT_BIO_COMPRESSED)
1632 return 0;
1633
1634 length = bio->bi_iter.bi_size;
1635 map_length = length;
1636 ret = btrfs_map_block(root->fs_info, rw, logical,
1637 &map_length, NULL, 0);
1638 /* Will always return 0 with map_multi == NULL */
1639 BUG_ON(ret < 0);
1640 if (map_length < length + size)
1641 return 1;
1642 return 0;
1643 }
1644
1645 /*
1646 * in order to insert checksums into the metadata in large chunks,
1647 * we wait until bio submission time. All the pages in the bio are
1648 * checksummed and sums are attached onto the ordered extent record.
1649 *
1650 * At IO completion time the cums attached on the ordered extent record
1651 * are inserted into the btree
1652 */
1653 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1654 struct bio *bio, int mirror_num,
1655 unsigned long bio_flags,
1656 u64 bio_offset)
1657 {
1658 struct btrfs_root *root = BTRFS_I(inode)->root;
1659 int ret = 0;
1660
1661 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1662 BUG_ON(ret); /* -ENOMEM */
1663 return 0;
1664 }
1665
1666 /*
1667 * in order to insert checksums into the metadata in large chunks,
1668 * we wait until bio submission time. All the pages in the bio are
1669 * checksummed and sums are attached onto the ordered extent record.
1670 *
1671 * At IO completion time the cums attached on the ordered extent record
1672 * are inserted into the btree
1673 */
1674 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1675 int mirror_num, unsigned long bio_flags,
1676 u64 bio_offset)
1677 {
1678 struct btrfs_root *root = BTRFS_I(inode)->root;
1679 int ret;
1680
1681 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
1682 if (ret)
1683 bio_endio(bio, ret);
1684 return ret;
1685 }
1686
1687 /*
1688 * extent_io.c submission hook. This does the right thing for csum calculation
1689 * on write, or reading the csums from the tree before a read
1690 */
1691 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1692 int mirror_num, unsigned long bio_flags,
1693 u64 bio_offset)
1694 {
1695 struct btrfs_root *root = BTRFS_I(inode)->root;
1696 int ret = 0;
1697 int skip_sum;
1698 int metadata = 0;
1699 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1700
1701 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1702
1703 if (btrfs_is_free_space_inode(inode))
1704 metadata = 2;
1705
1706 if (!(rw & REQ_WRITE)) {
1707 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1708 if (ret)
1709 goto out;
1710
1711 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1712 ret = btrfs_submit_compressed_read(inode, bio,
1713 mirror_num,
1714 bio_flags);
1715 goto out;
1716 } else if (!skip_sum) {
1717 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1718 if (ret)
1719 goto out;
1720 }
1721 goto mapit;
1722 } else if (async && !skip_sum) {
1723 /* csum items have already been cloned */
1724 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1725 goto mapit;
1726 /* we're doing a write, do the async checksumming */
1727 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1728 inode, rw, bio, mirror_num,
1729 bio_flags, bio_offset,
1730 __btrfs_submit_bio_start,
1731 __btrfs_submit_bio_done);
1732 goto out;
1733 } else if (!skip_sum) {
1734 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1735 if (ret)
1736 goto out;
1737 }
1738
1739 mapit:
1740 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
1741
1742 out:
1743 if (ret < 0)
1744 bio_endio(bio, ret);
1745 return ret;
1746 }
1747
1748 /*
1749 * given a list of ordered sums record them in the inode. This happens
1750 * at IO completion time based on sums calculated at bio submission time.
1751 */
1752 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1753 struct inode *inode, u64 file_offset,
1754 struct list_head *list)
1755 {
1756 struct btrfs_ordered_sum *sum;
1757
1758 list_for_each_entry(sum, list, list) {
1759 trans->adding_csums = 1;
1760 btrfs_csum_file_blocks(trans,
1761 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1762 trans->adding_csums = 0;
1763 }
1764 return 0;
1765 }
1766
1767 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1768 struct extent_state **cached_state)
1769 {
1770 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0);
1771 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1772 cached_state, GFP_NOFS);
1773 }
1774
1775 /* see btrfs_writepage_start_hook for details on why this is required */
1776 struct btrfs_writepage_fixup {
1777 struct page *page;
1778 struct btrfs_work work;
1779 };
1780
1781 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1782 {
1783 struct btrfs_writepage_fixup *fixup;
1784 struct btrfs_ordered_extent *ordered;
1785 struct extent_state *cached_state = NULL;
1786 struct page *page;
1787 struct inode *inode;
1788 u64 page_start;
1789 u64 page_end;
1790 int ret;
1791
1792 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1793 page = fixup->page;
1794 again:
1795 lock_page(page);
1796 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1797 ClearPageChecked(page);
1798 goto out_page;
1799 }
1800
1801 inode = page->mapping->host;
1802 page_start = page_offset(page);
1803 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1804
1805 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
1806 &cached_state);
1807
1808 /* already ordered? We're done */
1809 if (PagePrivate2(page))
1810 goto out;
1811
1812 ordered = btrfs_lookup_ordered_extent(inode, page_start);
1813 if (ordered) {
1814 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
1815 page_end, &cached_state, GFP_NOFS);
1816 unlock_page(page);
1817 btrfs_start_ordered_extent(inode, ordered, 1);
1818 btrfs_put_ordered_extent(ordered);
1819 goto again;
1820 }
1821
1822 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
1823 if (ret) {
1824 mapping_set_error(page->mapping, ret);
1825 end_extent_writepage(page, ret, page_start, page_end);
1826 ClearPageChecked(page);
1827 goto out;
1828 }
1829
1830 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
1831 ClearPageChecked(page);
1832 set_page_dirty(page);
1833 out:
1834 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
1835 &cached_state, GFP_NOFS);
1836 out_page:
1837 unlock_page(page);
1838 page_cache_release(page);
1839 kfree(fixup);
1840 }
1841
1842 /*
1843 * There are a few paths in the higher layers of the kernel that directly
1844 * set the page dirty bit without asking the filesystem if it is a
1845 * good idea. This causes problems because we want to make sure COW
1846 * properly happens and the data=ordered rules are followed.
1847 *
1848 * In our case any range that doesn't have the ORDERED bit set
1849 * hasn't been properly setup for IO. We kick off an async process
1850 * to fix it up. The async helper will wait for ordered extents, set
1851 * the delalloc bit and make it safe to write the page.
1852 */
1853 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
1854 {
1855 struct inode *inode = page->mapping->host;
1856 struct btrfs_writepage_fixup *fixup;
1857 struct btrfs_root *root = BTRFS_I(inode)->root;
1858
1859 /* this page is properly in the ordered list */
1860 if (TestClearPagePrivate2(page))
1861 return 0;
1862
1863 if (PageChecked(page))
1864 return -EAGAIN;
1865
1866 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
1867 if (!fixup)
1868 return -EAGAIN;
1869
1870 SetPageChecked(page);
1871 page_cache_get(page);
1872 btrfs_init_work(&fixup->work, btrfs_writepage_fixup_worker, NULL, NULL);
1873 fixup->page = page;
1874 btrfs_queue_work(root->fs_info->fixup_workers, &fixup->work);
1875 return -EBUSY;
1876 }
1877
1878 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
1879 struct inode *inode, u64 file_pos,
1880 u64 disk_bytenr, u64 disk_num_bytes,
1881 u64 num_bytes, u64 ram_bytes,
1882 u8 compression, u8 encryption,
1883 u16 other_encoding, int extent_type)
1884 {
1885 struct btrfs_root *root = BTRFS_I(inode)->root;
1886 struct btrfs_file_extent_item *fi;
1887 struct btrfs_path *path;
1888 struct extent_buffer *leaf;
1889 struct btrfs_key ins;
1890 int extent_inserted = 0;
1891 int ret;
1892
1893 path = btrfs_alloc_path();
1894 if (!path)
1895 return -ENOMEM;
1896
1897 /*
1898 * we may be replacing one extent in the tree with another.
1899 * The new extent is pinned in the extent map, and we don't want
1900 * to drop it from the cache until it is completely in the btree.
1901 *
1902 * So, tell btrfs_drop_extents to leave this extent in the cache.
1903 * the caller is expected to unpin it and allow it to be merged
1904 * with the others.
1905 */
1906 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
1907 file_pos + num_bytes, NULL, 0,
1908 1, sizeof(*fi), &extent_inserted);
1909 if (ret)
1910 goto out;
1911
1912 if (!extent_inserted) {
1913 ins.objectid = btrfs_ino(inode);
1914 ins.offset = file_pos;
1915 ins.type = BTRFS_EXTENT_DATA_KEY;
1916
1917 path->leave_spinning = 1;
1918 ret = btrfs_insert_empty_item(trans, root, path, &ins,
1919 sizeof(*fi));
1920 if (ret)
1921 goto out;
1922 }
1923 leaf = path->nodes[0];
1924 fi = btrfs_item_ptr(leaf, path->slots[0],
1925 struct btrfs_file_extent_item);
1926 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1927 btrfs_set_file_extent_type(leaf, fi, extent_type);
1928 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
1929 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
1930 btrfs_set_file_extent_offset(leaf, fi, 0);
1931 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
1932 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
1933 btrfs_set_file_extent_compression(leaf, fi, compression);
1934 btrfs_set_file_extent_encryption(leaf, fi, encryption);
1935 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
1936
1937 btrfs_mark_buffer_dirty(leaf);
1938 btrfs_release_path(path);
1939
1940 inode_add_bytes(inode, num_bytes);
1941
1942 ins.objectid = disk_bytenr;
1943 ins.offset = disk_num_bytes;
1944 ins.type = BTRFS_EXTENT_ITEM_KEY;
1945 ret = btrfs_alloc_reserved_file_extent(trans, root,
1946 root->root_key.objectid,
1947 btrfs_ino(inode), file_pos, &ins);
1948 out:
1949 btrfs_free_path(path);
1950
1951 return ret;
1952 }
1953
1954 /* snapshot-aware defrag */
1955 struct sa_defrag_extent_backref {
1956 struct rb_node node;
1957 struct old_sa_defrag_extent *old;
1958 u64 root_id;
1959 u64 inum;
1960 u64 file_pos;
1961 u64 extent_offset;
1962 u64 num_bytes;
1963 u64 generation;
1964 };
1965
1966 struct old_sa_defrag_extent {
1967 struct list_head list;
1968 struct new_sa_defrag_extent *new;
1969
1970 u64 extent_offset;
1971 u64 bytenr;
1972 u64 offset;
1973 u64 len;
1974 int count;
1975 };
1976
1977 struct new_sa_defrag_extent {
1978 struct rb_root root;
1979 struct list_head head;
1980 struct btrfs_path *path;
1981 struct inode *inode;
1982 u64 file_pos;
1983 u64 len;
1984 u64 bytenr;
1985 u64 disk_len;
1986 u8 compress_type;
1987 };
1988
1989 static int backref_comp(struct sa_defrag_extent_backref *b1,
1990 struct sa_defrag_extent_backref *b2)
1991 {
1992 if (b1->root_id < b2->root_id)
1993 return -1;
1994 else if (b1->root_id > b2->root_id)
1995 return 1;
1996
1997 if (b1->inum < b2->inum)
1998 return -1;
1999 else if (b1->inum > b2->inum)
2000 return 1;
2001
2002 if (b1->file_pos < b2->file_pos)
2003 return -1;
2004 else if (b1->file_pos > b2->file_pos)
2005 return 1;
2006
2007 /*
2008 * [------------------------------] ===> (a range of space)
2009 * |<--->| |<---->| =============> (fs/file tree A)
2010 * |<---------------------------->| ===> (fs/file tree B)
2011 *
2012 * A range of space can refer to two file extents in one tree while
2013 * refer to only one file extent in another tree.
2014 *
2015 * So we may process a disk offset more than one time(two extents in A)
2016 * and locate at the same extent(one extent in B), then insert two same
2017 * backrefs(both refer to the extent in B).
2018 */
2019 return 0;
2020 }
2021
2022 static void backref_insert(struct rb_root *root,
2023 struct sa_defrag_extent_backref *backref)
2024 {
2025 struct rb_node **p = &root->rb_node;
2026 struct rb_node *parent = NULL;
2027 struct sa_defrag_extent_backref *entry;
2028 int ret;
2029
2030 while (*p) {
2031 parent = *p;
2032 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2033
2034 ret = backref_comp(backref, entry);
2035 if (ret < 0)
2036 p = &(*p)->rb_left;
2037 else
2038 p = &(*p)->rb_right;
2039 }
2040
2041 rb_link_node(&backref->node, parent, p);
2042 rb_insert_color(&backref->node, root);
2043 }
2044
2045 /*
2046 * Note the backref might has changed, and in this case we just return 0.
2047 */
2048 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2049 void *ctx)
2050 {
2051 struct btrfs_file_extent_item *extent;
2052 struct btrfs_fs_info *fs_info;
2053 struct old_sa_defrag_extent *old = ctx;
2054 struct new_sa_defrag_extent *new = old->new;
2055 struct btrfs_path *path = new->path;
2056 struct btrfs_key key;
2057 struct btrfs_root *root;
2058 struct sa_defrag_extent_backref *backref;
2059 struct extent_buffer *leaf;
2060 struct inode *inode = new->inode;
2061 int slot;
2062 int ret;
2063 u64 extent_offset;
2064 u64 num_bytes;
2065
2066 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2067 inum == btrfs_ino(inode))
2068 return 0;
2069
2070 key.objectid = root_id;
2071 key.type = BTRFS_ROOT_ITEM_KEY;
2072 key.offset = (u64)-1;
2073
2074 fs_info = BTRFS_I(inode)->root->fs_info;
2075 root = btrfs_read_fs_root_no_name(fs_info, &key);
2076 if (IS_ERR(root)) {
2077 if (PTR_ERR(root) == -ENOENT)
2078 return 0;
2079 WARN_ON(1);
2080 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
2081 inum, offset, root_id);
2082 return PTR_ERR(root);
2083 }
2084
2085 key.objectid = inum;
2086 key.type = BTRFS_EXTENT_DATA_KEY;
2087 if (offset > (u64)-1 << 32)
2088 key.offset = 0;
2089 else
2090 key.offset = offset;
2091
2092 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2093 if (WARN_ON(ret < 0))
2094 return ret;
2095 ret = 0;
2096
2097 while (1) {
2098 cond_resched();
2099
2100 leaf = path->nodes[0];
2101 slot = path->slots[0];
2102
2103 if (slot >= btrfs_header_nritems(leaf)) {
2104 ret = btrfs_next_leaf(root, path);
2105 if (ret < 0) {
2106 goto out;
2107 } else if (ret > 0) {
2108 ret = 0;
2109 goto out;
2110 }
2111 continue;
2112 }
2113
2114 path->slots[0]++;
2115
2116 btrfs_item_key_to_cpu(leaf, &key, slot);
2117
2118 if (key.objectid > inum)
2119 goto out;
2120
2121 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2122 continue;
2123
2124 extent = btrfs_item_ptr(leaf, slot,
2125 struct btrfs_file_extent_item);
2126
2127 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2128 continue;
2129
2130 /*
2131 * 'offset' refers to the exact key.offset,
2132 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2133 * (key.offset - extent_offset).
2134 */
2135 if (key.offset != offset)
2136 continue;
2137
2138 extent_offset = btrfs_file_extent_offset(leaf, extent);
2139 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2140
2141 if (extent_offset >= old->extent_offset + old->offset +
2142 old->len || extent_offset + num_bytes <=
2143 old->extent_offset + old->offset)
2144 continue;
2145 break;
2146 }
2147
2148 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2149 if (!backref) {
2150 ret = -ENOENT;
2151 goto out;
2152 }
2153
2154 backref->root_id = root_id;
2155 backref->inum = inum;
2156 backref->file_pos = offset;
2157 backref->num_bytes = num_bytes;
2158 backref->extent_offset = extent_offset;
2159 backref->generation = btrfs_file_extent_generation(leaf, extent);
2160 backref->old = old;
2161 backref_insert(&new->root, backref);
2162 old->count++;
2163 out:
2164 btrfs_release_path(path);
2165 WARN_ON(ret);
2166 return ret;
2167 }
2168
2169 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2170 struct new_sa_defrag_extent *new)
2171 {
2172 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
2173 struct old_sa_defrag_extent *old, *tmp;
2174 int ret;
2175
2176 new->path = path;
2177
2178 list_for_each_entry_safe(old, tmp, &new->head, list) {
2179 ret = iterate_inodes_from_logical(old->bytenr +
2180 old->extent_offset, fs_info,
2181 path, record_one_backref,
2182 old);
2183 if (ret < 0 && ret != -ENOENT)
2184 return false;
2185
2186 /* no backref to be processed for this extent */
2187 if (!old->count) {
2188 list_del(&old->list);
2189 kfree(old);
2190 }
2191 }
2192
2193 if (list_empty(&new->head))
2194 return false;
2195
2196 return true;
2197 }
2198
2199 static int relink_is_mergable(struct extent_buffer *leaf,
2200 struct btrfs_file_extent_item *fi,
2201 struct new_sa_defrag_extent *new)
2202 {
2203 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2204 return 0;
2205
2206 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2207 return 0;
2208
2209 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2210 return 0;
2211
2212 if (btrfs_file_extent_encryption(leaf, fi) ||
2213 btrfs_file_extent_other_encoding(leaf, fi))
2214 return 0;
2215
2216 return 1;
2217 }
2218
2219 /*
2220 * Note the backref might has changed, and in this case we just return 0.
2221 */
2222 static noinline int relink_extent_backref(struct btrfs_path *path,
2223 struct sa_defrag_extent_backref *prev,
2224 struct sa_defrag_extent_backref *backref)
2225 {
2226 struct btrfs_file_extent_item *extent;
2227 struct btrfs_file_extent_item *item;
2228 struct btrfs_ordered_extent *ordered;
2229 struct btrfs_trans_handle *trans;
2230 struct btrfs_fs_info *fs_info;
2231 struct btrfs_root *root;
2232 struct btrfs_key key;
2233 struct extent_buffer *leaf;
2234 struct old_sa_defrag_extent *old = backref->old;
2235 struct new_sa_defrag_extent *new = old->new;
2236 struct inode *src_inode = new->inode;
2237 struct inode *inode;
2238 struct extent_state *cached = NULL;
2239 int ret = 0;
2240 u64 start;
2241 u64 len;
2242 u64 lock_start;
2243 u64 lock_end;
2244 bool merge = false;
2245 int index;
2246
2247 if (prev && prev->root_id == backref->root_id &&
2248 prev->inum == backref->inum &&
2249 prev->file_pos + prev->num_bytes == backref->file_pos)
2250 merge = true;
2251
2252 /* step 1: get root */
2253 key.objectid = backref->root_id;
2254 key.type = BTRFS_ROOT_ITEM_KEY;
2255 key.offset = (u64)-1;
2256
2257 fs_info = BTRFS_I(src_inode)->root->fs_info;
2258 index = srcu_read_lock(&fs_info->subvol_srcu);
2259
2260 root = btrfs_read_fs_root_no_name(fs_info, &key);
2261 if (IS_ERR(root)) {
2262 srcu_read_unlock(&fs_info->subvol_srcu, index);
2263 if (PTR_ERR(root) == -ENOENT)
2264 return 0;
2265 return PTR_ERR(root);
2266 }
2267
2268 if (btrfs_root_readonly(root)) {
2269 srcu_read_unlock(&fs_info->subvol_srcu, index);
2270 return 0;
2271 }
2272
2273 /* step 2: get inode */
2274 key.objectid = backref->inum;
2275 key.type = BTRFS_INODE_ITEM_KEY;
2276 key.offset = 0;
2277
2278 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2279 if (IS_ERR(inode)) {
2280 srcu_read_unlock(&fs_info->subvol_srcu, index);
2281 return 0;
2282 }
2283
2284 srcu_read_unlock(&fs_info->subvol_srcu, index);
2285
2286 /* step 3: relink backref */
2287 lock_start = backref->file_pos;
2288 lock_end = backref->file_pos + backref->num_bytes - 1;
2289 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2290 0, &cached);
2291
2292 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2293 if (ordered) {
2294 btrfs_put_ordered_extent(ordered);
2295 goto out_unlock;
2296 }
2297
2298 trans = btrfs_join_transaction(root);
2299 if (IS_ERR(trans)) {
2300 ret = PTR_ERR(trans);
2301 goto out_unlock;
2302 }
2303
2304 key.objectid = backref->inum;
2305 key.type = BTRFS_EXTENT_DATA_KEY;
2306 key.offset = backref->file_pos;
2307
2308 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2309 if (ret < 0) {
2310 goto out_free_path;
2311 } else if (ret > 0) {
2312 ret = 0;
2313 goto out_free_path;
2314 }
2315
2316 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2317 struct btrfs_file_extent_item);
2318
2319 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2320 backref->generation)
2321 goto out_free_path;
2322
2323 btrfs_release_path(path);
2324
2325 start = backref->file_pos;
2326 if (backref->extent_offset < old->extent_offset + old->offset)
2327 start += old->extent_offset + old->offset -
2328 backref->extent_offset;
2329
2330 len = min(backref->extent_offset + backref->num_bytes,
2331 old->extent_offset + old->offset + old->len);
2332 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2333
2334 ret = btrfs_drop_extents(trans, root, inode, start,
2335 start + len, 1);
2336 if (ret)
2337 goto out_free_path;
2338 again:
2339 key.objectid = btrfs_ino(inode);
2340 key.type = BTRFS_EXTENT_DATA_KEY;
2341 key.offset = start;
2342
2343 path->leave_spinning = 1;
2344 if (merge) {
2345 struct btrfs_file_extent_item *fi;
2346 u64 extent_len;
2347 struct btrfs_key found_key;
2348
2349 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2350 if (ret < 0)
2351 goto out_free_path;
2352
2353 path->slots[0]--;
2354 leaf = path->nodes[0];
2355 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2356
2357 fi = btrfs_item_ptr(leaf, path->slots[0],
2358 struct btrfs_file_extent_item);
2359 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2360
2361 if (extent_len + found_key.offset == start &&
2362 relink_is_mergable(leaf, fi, new)) {
2363 btrfs_set_file_extent_num_bytes(leaf, fi,
2364 extent_len + len);
2365 btrfs_mark_buffer_dirty(leaf);
2366 inode_add_bytes(inode, len);
2367
2368 ret = 1;
2369 goto out_free_path;
2370 } else {
2371 merge = false;
2372 btrfs_release_path(path);
2373 goto again;
2374 }
2375 }
2376
2377 ret = btrfs_insert_empty_item(trans, root, path, &key,
2378 sizeof(*extent));
2379 if (ret) {
2380 btrfs_abort_transaction(trans, root, ret);
2381 goto out_free_path;
2382 }
2383
2384 leaf = path->nodes[0];
2385 item = btrfs_item_ptr(leaf, path->slots[0],
2386 struct btrfs_file_extent_item);
2387 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2388 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2389 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2390 btrfs_set_file_extent_num_bytes(leaf, item, len);
2391 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2392 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2393 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2394 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2395 btrfs_set_file_extent_encryption(leaf, item, 0);
2396 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2397
2398 btrfs_mark_buffer_dirty(leaf);
2399 inode_add_bytes(inode, len);
2400 btrfs_release_path(path);
2401
2402 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2403 new->disk_len, 0,
2404 backref->root_id, backref->inum,
2405 new->file_pos, 0); /* start - extent_offset */
2406 if (ret) {
2407 btrfs_abort_transaction(trans, root, ret);
2408 goto out_free_path;
2409 }
2410
2411 ret = 1;
2412 out_free_path:
2413 btrfs_release_path(path);
2414 path->leave_spinning = 0;
2415 btrfs_end_transaction(trans, root);
2416 out_unlock:
2417 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2418 &cached, GFP_NOFS);
2419 iput(inode);
2420 return ret;
2421 }
2422
2423 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2424 {
2425 struct old_sa_defrag_extent *old, *tmp;
2426
2427 if (!new)
2428 return;
2429
2430 list_for_each_entry_safe(old, tmp, &new->head, list) {
2431 list_del(&old->list);
2432 kfree(old);
2433 }
2434 kfree(new);
2435 }
2436
2437 static void relink_file_extents(struct new_sa_defrag_extent *new)
2438 {
2439 struct btrfs_path *path;
2440 struct sa_defrag_extent_backref *backref;
2441 struct sa_defrag_extent_backref *prev = NULL;
2442 struct inode *inode;
2443 struct btrfs_root *root;
2444 struct rb_node *node;
2445 int ret;
2446
2447 inode = new->inode;
2448 root = BTRFS_I(inode)->root;
2449
2450 path = btrfs_alloc_path();
2451 if (!path)
2452 return;
2453
2454 if (!record_extent_backrefs(path, new)) {
2455 btrfs_free_path(path);
2456 goto out;
2457 }
2458 btrfs_release_path(path);
2459
2460 while (1) {
2461 node = rb_first(&new->root);
2462 if (!node)
2463 break;
2464 rb_erase(node, &new->root);
2465
2466 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2467
2468 ret = relink_extent_backref(path, prev, backref);
2469 WARN_ON(ret < 0);
2470
2471 kfree(prev);
2472
2473 if (ret == 1)
2474 prev = backref;
2475 else
2476 prev = NULL;
2477 cond_resched();
2478 }
2479 kfree(prev);
2480
2481 btrfs_free_path(path);
2482 out:
2483 free_sa_defrag_extent(new);
2484
2485 atomic_dec(&root->fs_info->defrag_running);
2486 wake_up(&root->fs_info->transaction_wait);
2487 }
2488
2489 static struct new_sa_defrag_extent *
2490 record_old_file_extents(struct inode *inode,
2491 struct btrfs_ordered_extent *ordered)
2492 {
2493 struct btrfs_root *root = BTRFS_I(inode)->root;
2494 struct btrfs_path *path;
2495 struct btrfs_key key;
2496 struct old_sa_defrag_extent *old;
2497 struct new_sa_defrag_extent *new;
2498 int ret;
2499
2500 new = kmalloc(sizeof(*new), GFP_NOFS);
2501 if (!new)
2502 return NULL;
2503
2504 new->inode = inode;
2505 new->file_pos = ordered->file_offset;
2506 new->len = ordered->len;
2507 new->bytenr = ordered->start;
2508 new->disk_len = ordered->disk_len;
2509 new->compress_type = ordered->compress_type;
2510 new->root = RB_ROOT;
2511 INIT_LIST_HEAD(&new->head);
2512
2513 path = btrfs_alloc_path();
2514 if (!path)
2515 goto out_kfree;
2516
2517 key.objectid = btrfs_ino(inode);
2518 key.type = BTRFS_EXTENT_DATA_KEY;
2519 key.offset = new->file_pos;
2520
2521 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2522 if (ret < 0)
2523 goto out_free_path;
2524 if (ret > 0 && path->slots[0] > 0)
2525 path->slots[0]--;
2526
2527 /* find out all the old extents for the file range */
2528 while (1) {
2529 struct btrfs_file_extent_item *extent;
2530 struct extent_buffer *l;
2531 int slot;
2532 u64 num_bytes;
2533 u64 offset;
2534 u64 end;
2535 u64 disk_bytenr;
2536 u64 extent_offset;
2537
2538 l = path->nodes[0];
2539 slot = path->slots[0];
2540
2541 if (slot >= btrfs_header_nritems(l)) {
2542 ret = btrfs_next_leaf(root, path);
2543 if (ret < 0)
2544 goto out_free_path;
2545 else if (ret > 0)
2546 break;
2547 continue;
2548 }
2549
2550 btrfs_item_key_to_cpu(l, &key, slot);
2551
2552 if (key.objectid != btrfs_ino(inode))
2553 break;
2554 if (key.type != BTRFS_EXTENT_DATA_KEY)
2555 break;
2556 if (key.offset >= new->file_pos + new->len)
2557 break;
2558
2559 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2560
2561 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2562 if (key.offset + num_bytes < new->file_pos)
2563 goto next;
2564
2565 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2566 if (!disk_bytenr)
2567 goto next;
2568
2569 extent_offset = btrfs_file_extent_offset(l, extent);
2570
2571 old = kmalloc(sizeof(*old), GFP_NOFS);
2572 if (!old)
2573 goto out_free_path;
2574
2575 offset = max(new->file_pos, key.offset);
2576 end = min(new->file_pos + new->len, key.offset + num_bytes);
2577
2578 old->bytenr = disk_bytenr;
2579 old->extent_offset = extent_offset;
2580 old->offset = offset - key.offset;
2581 old->len = end - offset;
2582 old->new = new;
2583 old->count = 0;
2584 list_add_tail(&old->list, &new->head);
2585 next:
2586 path->slots[0]++;
2587 cond_resched();
2588 }
2589
2590 btrfs_free_path(path);
2591 atomic_inc(&root->fs_info->defrag_running);
2592
2593 return new;
2594
2595 out_free_path:
2596 btrfs_free_path(path);
2597 out_kfree:
2598 free_sa_defrag_extent(new);
2599 return NULL;
2600 }
2601
2602 /* as ordered data IO finishes, this gets called so we can finish
2603 * an ordered extent if the range of bytes in the file it covers are
2604 * fully written.
2605 */
2606 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2607 {
2608 struct inode *inode = ordered_extent->inode;
2609 struct btrfs_root *root = BTRFS_I(inode)->root;
2610 struct btrfs_trans_handle *trans = NULL;
2611 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2612 struct extent_state *cached_state = NULL;
2613 struct new_sa_defrag_extent *new = NULL;
2614 int compress_type = 0;
2615 int ret = 0;
2616 u64 logical_len = ordered_extent->len;
2617 bool nolock;
2618 bool truncated = false;
2619
2620 nolock = btrfs_is_free_space_inode(inode);
2621
2622 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2623 ret = -EIO;
2624 goto out;
2625 }
2626
2627 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2628 truncated = true;
2629 logical_len = ordered_extent->truncated_len;
2630 /* Truncated the entire extent, don't bother adding */
2631 if (!logical_len)
2632 goto out;
2633 }
2634
2635 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2636 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2637 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2638 if (nolock)
2639 trans = btrfs_join_transaction_nolock(root);
2640 else
2641 trans = btrfs_join_transaction(root);
2642 if (IS_ERR(trans)) {
2643 ret = PTR_ERR(trans);
2644 trans = NULL;
2645 goto out;
2646 }
2647 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2648 ret = btrfs_update_inode_fallback(trans, root, inode);
2649 if (ret) /* -ENOMEM or corruption */
2650 btrfs_abort_transaction(trans, root, ret);
2651 goto out;
2652 }
2653
2654 lock_extent_bits(io_tree, ordered_extent->file_offset,
2655 ordered_extent->file_offset + ordered_extent->len - 1,
2656 0, &cached_state);
2657
2658 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2659 ordered_extent->file_offset + ordered_extent->len - 1,
2660 EXTENT_DEFRAG, 1, cached_state);
2661 if (ret) {
2662 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2663 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
2664 /* the inode is shared */
2665 new = record_old_file_extents(inode, ordered_extent);
2666
2667 clear_extent_bit(io_tree, ordered_extent->file_offset,
2668 ordered_extent->file_offset + ordered_extent->len - 1,
2669 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2670 }
2671
2672 if (nolock)
2673 trans = btrfs_join_transaction_nolock(root);
2674 else
2675 trans = btrfs_join_transaction(root);
2676 if (IS_ERR(trans)) {
2677 ret = PTR_ERR(trans);
2678 trans = NULL;
2679 goto out_unlock;
2680 }
2681 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2682
2683 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2684 compress_type = ordered_extent->compress_type;
2685 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2686 BUG_ON(compress_type);
2687 ret = btrfs_mark_extent_written(trans, inode,
2688 ordered_extent->file_offset,
2689 ordered_extent->file_offset +
2690 logical_len);
2691 } else {
2692 BUG_ON(root == root->fs_info->tree_root);
2693 ret = insert_reserved_file_extent(trans, inode,
2694 ordered_extent->file_offset,
2695 ordered_extent->start,
2696 ordered_extent->disk_len,
2697 logical_len, logical_len,
2698 compress_type, 0, 0,
2699 BTRFS_FILE_EXTENT_REG);
2700 }
2701 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2702 ordered_extent->file_offset, ordered_extent->len,
2703 trans->transid);
2704 if (ret < 0) {
2705 btrfs_abort_transaction(trans, root, ret);
2706 goto out_unlock;
2707 }
2708
2709 add_pending_csums(trans, inode, ordered_extent->file_offset,
2710 &ordered_extent->list);
2711
2712 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2713 ret = btrfs_update_inode_fallback(trans, root, inode);
2714 if (ret) { /* -ENOMEM or corruption */
2715 btrfs_abort_transaction(trans, root, ret);
2716 goto out_unlock;
2717 }
2718 ret = 0;
2719 out_unlock:
2720 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2721 ordered_extent->file_offset +
2722 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2723 out:
2724 if (root != root->fs_info->tree_root)
2725 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2726 if (trans)
2727 btrfs_end_transaction(trans, root);
2728
2729 if (ret || truncated) {
2730 u64 start, end;
2731
2732 if (truncated)
2733 start = ordered_extent->file_offset + logical_len;
2734 else
2735 start = ordered_extent->file_offset;
2736 end = ordered_extent->file_offset + ordered_extent->len - 1;
2737 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
2738
2739 /* Drop the cache for the part of the extent we didn't write. */
2740 btrfs_drop_extent_cache(inode, start, end, 0);
2741
2742 /*
2743 * If the ordered extent had an IOERR or something else went
2744 * wrong we need to return the space for this ordered extent
2745 * back to the allocator. We only free the extent in the
2746 * truncated case if we didn't write out the extent at all.
2747 */
2748 if ((ret || !logical_len) &&
2749 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2750 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
2751 btrfs_free_reserved_extent(root, ordered_extent->start,
2752 ordered_extent->disk_len);
2753 }
2754
2755
2756 /*
2757 * This needs to be done to make sure anybody waiting knows we are done
2758 * updating everything for this ordered extent.
2759 */
2760 btrfs_remove_ordered_extent(inode, ordered_extent);
2761
2762 /* for snapshot-aware defrag */
2763 if (new) {
2764 if (ret) {
2765 free_sa_defrag_extent(new);
2766 atomic_dec(&root->fs_info->defrag_running);
2767 } else {
2768 relink_file_extents(new);
2769 }
2770 }
2771
2772 /* once for us */
2773 btrfs_put_ordered_extent(ordered_extent);
2774 /* once for the tree */
2775 btrfs_put_ordered_extent(ordered_extent);
2776
2777 return ret;
2778 }
2779
2780 static void finish_ordered_fn(struct btrfs_work *work)
2781 {
2782 struct btrfs_ordered_extent *ordered_extent;
2783 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
2784 btrfs_finish_ordered_io(ordered_extent);
2785 }
2786
2787 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
2788 struct extent_state *state, int uptodate)
2789 {
2790 struct inode *inode = page->mapping->host;
2791 struct btrfs_root *root = BTRFS_I(inode)->root;
2792 struct btrfs_ordered_extent *ordered_extent = NULL;
2793 struct btrfs_workqueue *workers;
2794
2795 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
2796
2797 ClearPagePrivate2(page);
2798 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
2799 end - start + 1, uptodate))
2800 return 0;
2801
2802 btrfs_init_work(&ordered_extent->work, finish_ordered_fn, NULL, NULL);
2803
2804 if (btrfs_is_free_space_inode(inode))
2805 workers = root->fs_info->endio_freespace_worker;
2806 else
2807 workers = root->fs_info->endio_write_workers;
2808 btrfs_queue_work(workers, &ordered_extent->work);
2809
2810 return 0;
2811 }
2812
2813 /*
2814 * when reads are done, we need to check csums to verify the data is correct
2815 * if there's a match, we allow the bio to finish. If not, the code in
2816 * extent_io.c will try to find good copies for us.
2817 */
2818 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
2819 u64 phy_offset, struct page *page,
2820 u64 start, u64 end, int mirror)
2821 {
2822 size_t offset = start - page_offset(page);
2823 struct inode *inode = page->mapping->host;
2824 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2825 char *kaddr;
2826 struct btrfs_root *root = BTRFS_I(inode)->root;
2827 u32 csum_expected;
2828 u32 csum = ~(u32)0;
2829 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
2830 DEFAULT_RATELIMIT_BURST);
2831
2832 if (PageChecked(page)) {
2833 ClearPageChecked(page);
2834 goto good;
2835 }
2836
2837 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
2838 goto good;
2839
2840 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
2841 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
2842 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
2843 GFP_NOFS);
2844 return 0;
2845 }
2846
2847 phy_offset >>= inode->i_sb->s_blocksize_bits;
2848 csum_expected = *(((u32 *)io_bio->csum) + phy_offset);
2849
2850 kaddr = kmap_atomic(page);
2851 csum = btrfs_csum_data(kaddr + offset, csum, end - start + 1);
2852 btrfs_csum_final(csum, (char *)&csum);
2853 if (csum != csum_expected)
2854 goto zeroit;
2855
2856 kunmap_atomic(kaddr);
2857 good:
2858 return 0;
2859
2860 zeroit:
2861 if (__ratelimit(&_rs))
2862 btrfs_info(root->fs_info, "csum failed ino %llu off %llu csum %u expected csum %u",
2863 btrfs_ino(page->mapping->host), start, csum, csum_expected);
2864 memset(kaddr + offset, 1, end - start + 1);
2865 flush_dcache_page(page);
2866 kunmap_atomic(kaddr);
2867 if (csum_expected == 0)
2868 return 0;
2869 return -EIO;
2870 }
2871
2872 struct delayed_iput {
2873 struct list_head list;
2874 struct inode *inode;
2875 };
2876
2877 /* JDM: If this is fs-wide, why can't we add a pointer to
2878 * btrfs_inode instead and avoid the allocation? */
2879 void btrfs_add_delayed_iput(struct inode *inode)
2880 {
2881 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2882 struct delayed_iput *delayed;
2883
2884 if (atomic_add_unless(&inode->i_count, -1, 1))
2885 return;
2886
2887 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
2888 delayed->inode = inode;
2889
2890 spin_lock(&fs_info->delayed_iput_lock);
2891 list_add_tail(&delayed->list, &fs_info->delayed_iputs);
2892 spin_unlock(&fs_info->delayed_iput_lock);
2893 }
2894
2895 void btrfs_run_delayed_iputs(struct btrfs_root *root)
2896 {
2897 LIST_HEAD(list);
2898 struct btrfs_fs_info *fs_info = root->fs_info;
2899 struct delayed_iput *delayed;
2900 int empty;
2901
2902 spin_lock(&fs_info->delayed_iput_lock);
2903 empty = list_empty(&fs_info->delayed_iputs);
2904 spin_unlock(&fs_info->delayed_iput_lock);
2905 if (empty)
2906 return;
2907
2908 spin_lock(&fs_info->delayed_iput_lock);
2909 list_splice_init(&fs_info->delayed_iputs, &list);
2910 spin_unlock(&fs_info->delayed_iput_lock);
2911
2912 while (!list_empty(&list)) {
2913 delayed = list_entry(list.next, struct delayed_iput, list);
2914 list_del(&delayed->list);
2915 iput(delayed->inode);
2916 kfree(delayed);
2917 }
2918 }
2919
2920 /*
2921 * This is called in transaction commit time. If there are no orphan
2922 * files in the subvolume, it removes orphan item and frees block_rsv
2923 * structure.
2924 */
2925 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
2926 struct btrfs_root *root)
2927 {
2928 struct btrfs_block_rsv *block_rsv;
2929 int ret;
2930
2931 if (atomic_read(&root->orphan_inodes) ||
2932 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
2933 return;
2934
2935 spin_lock(&root->orphan_lock);
2936 if (atomic_read(&root->orphan_inodes)) {
2937 spin_unlock(&root->orphan_lock);
2938 return;
2939 }
2940
2941 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
2942 spin_unlock(&root->orphan_lock);
2943 return;
2944 }
2945
2946 block_rsv = root->orphan_block_rsv;
2947 root->orphan_block_rsv = NULL;
2948 spin_unlock(&root->orphan_lock);
2949
2950 if (root->orphan_item_inserted &&
2951 btrfs_root_refs(&root->root_item) > 0) {
2952 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
2953 root->root_key.objectid);
2954 if (ret)
2955 btrfs_abort_transaction(trans, root, ret);
2956 else
2957 root->orphan_item_inserted = 0;
2958 }
2959
2960 if (block_rsv) {
2961 WARN_ON(block_rsv->size > 0);
2962 btrfs_free_block_rsv(root, block_rsv);
2963 }
2964 }
2965
2966 /*
2967 * This creates an orphan entry for the given inode in case something goes
2968 * wrong in the middle of an unlink/truncate.
2969 *
2970 * NOTE: caller of this function should reserve 5 units of metadata for
2971 * this function.
2972 */
2973 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
2974 {
2975 struct btrfs_root *root = BTRFS_I(inode)->root;
2976 struct btrfs_block_rsv *block_rsv = NULL;
2977 int reserve = 0;
2978 int insert = 0;
2979 int ret;
2980
2981 if (!root->orphan_block_rsv) {
2982 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
2983 if (!block_rsv)
2984 return -ENOMEM;
2985 }
2986
2987 spin_lock(&root->orphan_lock);
2988 if (!root->orphan_block_rsv) {
2989 root->orphan_block_rsv = block_rsv;
2990 } else if (block_rsv) {
2991 btrfs_free_block_rsv(root, block_rsv);
2992 block_rsv = NULL;
2993 }
2994
2995 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
2996 &BTRFS_I(inode)->runtime_flags)) {
2997 #if 0
2998 /*
2999 * For proper ENOSPC handling, we should do orphan
3000 * cleanup when mounting. But this introduces backward
3001 * compatibility issue.
3002 */
3003 if (!xchg(&root->orphan_item_inserted, 1))
3004 insert = 2;
3005 else
3006 insert = 1;
3007 #endif
3008 insert = 1;
3009 atomic_inc(&root->orphan_inodes);
3010 }
3011
3012 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3013 &BTRFS_I(inode)->runtime_flags))
3014 reserve = 1;
3015 spin_unlock(&root->orphan_lock);
3016
3017 /* grab metadata reservation from transaction handle */
3018 if (reserve) {
3019 ret = btrfs_orphan_reserve_metadata(trans, inode);
3020 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
3021 }
3022
3023 /* insert an orphan item to track this unlinked/truncated file */
3024 if (insert >= 1) {
3025 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3026 if (ret) {
3027 atomic_dec(&root->orphan_inodes);
3028 if (reserve) {
3029 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3030 &BTRFS_I(inode)->runtime_flags);
3031 btrfs_orphan_release_metadata(inode);
3032 }
3033 if (ret != -EEXIST) {
3034 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3035 &BTRFS_I(inode)->runtime_flags);
3036 btrfs_abort_transaction(trans, root, ret);
3037 return ret;
3038 }
3039 }
3040 ret = 0;
3041 }
3042
3043 /* insert an orphan item to track subvolume contains orphan files */
3044 if (insert >= 2) {
3045 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
3046 root->root_key.objectid);
3047 if (ret && ret != -EEXIST) {
3048 btrfs_abort_transaction(trans, root, ret);
3049 return ret;
3050 }
3051 }
3052 return 0;
3053 }
3054
3055 /*
3056 * We have done the truncate/delete so we can go ahead and remove the orphan
3057 * item for this particular inode.
3058 */
3059 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3060 struct inode *inode)
3061 {
3062 struct btrfs_root *root = BTRFS_I(inode)->root;
3063 int delete_item = 0;
3064 int release_rsv = 0;
3065 int ret = 0;
3066
3067 spin_lock(&root->orphan_lock);
3068 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3069 &BTRFS_I(inode)->runtime_flags))
3070 delete_item = 1;
3071
3072 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3073 &BTRFS_I(inode)->runtime_flags))
3074 release_rsv = 1;
3075 spin_unlock(&root->orphan_lock);
3076
3077 if (delete_item) {
3078 atomic_dec(&root->orphan_inodes);
3079 if (trans)
3080 ret = btrfs_del_orphan_item(trans, root,
3081 btrfs_ino(inode));
3082 }
3083
3084 if (release_rsv)
3085 btrfs_orphan_release_metadata(inode);
3086
3087 return ret;
3088 }
3089
3090 /*
3091 * this cleans up any orphans that may be left on the list from the last use
3092 * of this root.
3093 */
3094 int btrfs_orphan_cleanup(struct btrfs_root *root)
3095 {
3096 struct btrfs_path *path;
3097 struct extent_buffer *leaf;
3098 struct btrfs_key key, found_key;
3099 struct btrfs_trans_handle *trans;
3100 struct inode *inode;
3101 u64 last_objectid = 0;
3102 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3103
3104 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3105 return 0;
3106
3107 path = btrfs_alloc_path();
3108 if (!path) {
3109 ret = -ENOMEM;
3110 goto out;
3111 }
3112 path->reada = -1;
3113
3114 key.objectid = BTRFS_ORPHAN_OBJECTID;
3115 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
3116 key.offset = (u64)-1;
3117
3118 while (1) {
3119 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3120 if (ret < 0)
3121 goto out;
3122
3123 /*
3124 * if ret == 0 means we found what we were searching for, which
3125 * is weird, but possible, so only screw with path if we didn't
3126 * find the key and see if we have stuff that matches
3127 */
3128 if (ret > 0) {
3129 ret = 0;
3130 if (path->slots[0] == 0)
3131 break;
3132 path->slots[0]--;
3133 }
3134
3135 /* pull out the item */
3136 leaf = path->nodes[0];
3137 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3138
3139 /* make sure the item matches what we want */
3140 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3141 break;
3142 if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
3143 break;
3144
3145 /* release the path since we're done with it */
3146 btrfs_release_path(path);
3147
3148 /*
3149 * this is where we are basically btrfs_lookup, without the
3150 * crossing root thing. we store the inode number in the
3151 * offset of the orphan item.
3152 */
3153
3154 if (found_key.offset == last_objectid) {
3155 btrfs_err(root->fs_info,
3156 "Error removing orphan entry, stopping orphan cleanup");
3157 ret = -EINVAL;
3158 goto out;
3159 }
3160
3161 last_objectid = found_key.offset;
3162
3163 found_key.objectid = found_key.offset;
3164 found_key.type = BTRFS_INODE_ITEM_KEY;
3165 found_key.offset = 0;
3166 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3167 ret = PTR_ERR_OR_ZERO(inode);
3168 if (ret && ret != -ESTALE)
3169 goto out;
3170
3171 if (ret == -ESTALE && root == root->fs_info->tree_root) {
3172 struct btrfs_root *dead_root;
3173 struct btrfs_fs_info *fs_info = root->fs_info;
3174 int is_dead_root = 0;
3175
3176 /*
3177 * this is an orphan in the tree root. Currently these
3178 * could come from 2 sources:
3179 * a) a snapshot deletion in progress
3180 * b) a free space cache inode
3181 * We need to distinguish those two, as the snapshot
3182 * orphan must not get deleted.
3183 * find_dead_roots already ran before us, so if this
3184 * is a snapshot deletion, we should find the root
3185 * in the dead_roots list
3186 */
3187 spin_lock(&fs_info->trans_lock);
3188 list_for_each_entry(dead_root, &fs_info->dead_roots,
3189 root_list) {
3190 if (dead_root->root_key.objectid ==
3191 found_key.objectid) {
3192 is_dead_root = 1;
3193 break;
3194 }
3195 }
3196 spin_unlock(&fs_info->trans_lock);
3197 if (is_dead_root) {
3198 /* prevent this orphan from being found again */
3199 key.offset = found_key.objectid - 1;
3200 continue;
3201 }
3202 }
3203 /*
3204 * Inode is already gone but the orphan item is still there,
3205 * kill the orphan item.
3206 */
3207 if (ret == -ESTALE) {
3208 trans = btrfs_start_transaction(root, 1);
3209 if (IS_ERR(trans)) {
3210 ret = PTR_ERR(trans);
3211 goto out;
3212 }
3213 btrfs_debug(root->fs_info, "auto deleting %Lu",
3214 found_key.objectid);
3215 ret = btrfs_del_orphan_item(trans, root,
3216 found_key.objectid);
3217 btrfs_end_transaction(trans, root);
3218 if (ret)
3219 goto out;
3220 continue;
3221 }
3222
3223 /*
3224 * add this inode to the orphan list so btrfs_orphan_del does
3225 * the proper thing when we hit it
3226 */
3227 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3228 &BTRFS_I(inode)->runtime_flags);
3229 atomic_inc(&root->orphan_inodes);
3230
3231 /* if we have links, this was a truncate, lets do that */
3232 if (inode->i_nlink) {
3233 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3234 iput(inode);
3235 continue;
3236 }
3237 nr_truncate++;
3238
3239 /* 1 for the orphan item deletion. */
3240 trans = btrfs_start_transaction(root, 1);
3241 if (IS_ERR(trans)) {
3242 iput(inode);
3243 ret = PTR_ERR(trans);
3244 goto out;
3245 }
3246 ret = btrfs_orphan_add(trans, inode);
3247 btrfs_end_transaction(trans, root);
3248 if (ret) {
3249 iput(inode);
3250 goto out;
3251 }
3252
3253 ret = btrfs_truncate(inode);
3254 if (ret)
3255 btrfs_orphan_del(NULL, inode);
3256 } else {
3257 nr_unlink++;
3258 }
3259
3260 /* this will do delete_inode and everything for us */
3261 iput(inode);
3262 if (ret)
3263 goto out;
3264 }
3265 /* release the path since we're done with it */
3266 btrfs_release_path(path);
3267
3268 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3269
3270 if (root->orphan_block_rsv)
3271 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3272 (u64)-1);
3273
3274 if (root->orphan_block_rsv || root->orphan_item_inserted) {
3275 trans = btrfs_join_transaction(root);
3276 if (!IS_ERR(trans))
3277 btrfs_end_transaction(trans, root);
3278 }
3279
3280 if (nr_unlink)
3281 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3282 if (nr_truncate)
3283 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3284
3285 out:
3286 if (ret)
3287 btrfs_crit(root->fs_info,
3288 "could not do orphan cleanup %d", ret);
3289 btrfs_free_path(path);
3290 return ret;
3291 }
3292
3293 /*
3294 * very simple check to peek ahead in the leaf looking for xattrs. If we
3295 * don't find any xattrs, we know there can't be any acls.
3296 *
3297 * slot is the slot the inode is in, objectid is the objectid of the inode
3298 */
3299 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3300 int slot, u64 objectid,
3301 int *first_xattr_slot)
3302 {
3303 u32 nritems = btrfs_header_nritems(leaf);
3304 struct btrfs_key found_key;
3305 static u64 xattr_access = 0;
3306 static u64 xattr_default = 0;
3307 int scanned = 0;
3308
3309 if (!xattr_access) {
3310 xattr_access = btrfs_name_hash(POSIX_ACL_XATTR_ACCESS,
3311 strlen(POSIX_ACL_XATTR_ACCESS));
3312 xattr_default = btrfs_name_hash(POSIX_ACL_XATTR_DEFAULT,
3313 strlen(POSIX_ACL_XATTR_DEFAULT));
3314 }
3315
3316 slot++;
3317 *first_xattr_slot = -1;
3318 while (slot < nritems) {
3319 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3320
3321 /* we found a different objectid, there must not be acls */
3322 if (found_key.objectid != objectid)
3323 return 0;
3324
3325 /* we found an xattr, assume we've got an acl */
3326 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3327 if (*first_xattr_slot == -1)
3328 *first_xattr_slot = slot;
3329 if (found_key.offset == xattr_access ||
3330 found_key.offset == xattr_default)
3331 return 1;
3332 }
3333
3334 /*
3335 * we found a key greater than an xattr key, there can't
3336 * be any acls later on
3337 */
3338 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3339 return 0;
3340
3341 slot++;
3342 scanned++;
3343
3344 /*
3345 * it goes inode, inode backrefs, xattrs, extents,
3346 * so if there are a ton of hard links to an inode there can
3347 * be a lot of backrefs. Don't waste time searching too hard,
3348 * this is just an optimization
3349 */
3350 if (scanned >= 8)
3351 break;
3352 }
3353 /* we hit the end of the leaf before we found an xattr or
3354 * something larger than an xattr. We have to assume the inode
3355 * has acls
3356 */
3357 if (*first_xattr_slot == -1)
3358 *first_xattr_slot = slot;
3359 return 1;
3360 }
3361
3362 /*
3363 * read an inode from the btree into the in-memory inode
3364 */
3365 static void btrfs_read_locked_inode(struct inode *inode)
3366 {
3367 struct btrfs_path *path;
3368 struct extent_buffer *leaf;
3369 struct btrfs_inode_item *inode_item;
3370 struct btrfs_timespec *tspec;
3371 struct btrfs_root *root = BTRFS_I(inode)->root;
3372 struct btrfs_key location;
3373 unsigned long ptr;
3374 int maybe_acls;
3375 u32 rdev;
3376 int ret;
3377 bool filled = false;
3378 int first_xattr_slot;
3379
3380 ret = btrfs_fill_inode(inode, &rdev);
3381 if (!ret)
3382 filled = true;
3383
3384 path = btrfs_alloc_path();
3385 if (!path)
3386 goto make_bad;
3387
3388 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3389
3390 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3391 if (ret)
3392 goto make_bad;
3393
3394 leaf = path->nodes[0];
3395
3396 if (filled)
3397 goto cache_index;
3398
3399 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3400 struct btrfs_inode_item);
3401 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3402 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3403 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3404 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3405 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3406
3407 tspec = btrfs_inode_atime(inode_item);
3408 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3409 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3410
3411 tspec = btrfs_inode_mtime(inode_item);
3412 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3413 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3414
3415 tspec = btrfs_inode_ctime(inode_item);
3416 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3417 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3418
3419 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3420 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3421 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3422
3423 /*
3424 * If we were modified in the current generation and evicted from memory
3425 * and then re-read we need to do a full sync since we don't have any
3426 * idea about which extents were modified before we were evicted from
3427 * cache.
3428 */
3429 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3430 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3431 &BTRFS_I(inode)->runtime_flags);
3432
3433 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3434 inode->i_generation = BTRFS_I(inode)->generation;
3435 inode->i_rdev = 0;
3436 rdev = btrfs_inode_rdev(leaf, inode_item);
3437
3438 BTRFS_I(inode)->index_cnt = (u64)-1;
3439 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3440
3441 cache_index:
3442 path->slots[0]++;
3443 if (inode->i_nlink != 1 ||
3444 path->slots[0] >= btrfs_header_nritems(leaf))
3445 goto cache_acl;
3446
3447 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3448 if (location.objectid != btrfs_ino(inode))
3449 goto cache_acl;
3450
3451 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3452 if (location.type == BTRFS_INODE_REF_KEY) {
3453 struct btrfs_inode_ref *ref;
3454
3455 ref = (struct btrfs_inode_ref *)ptr;
3456 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3457 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3458 struct btrfs_inode_extref *extref;
3459
3460 extref = (struct btrfs_inode_extref *)ptr;
3461 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3462 extref);
3463 }
3464 cache_acl:
3465 /*
3466 * try to precache a NULL acl entry for files that don't have
3467 * any xattrs or acls
3468 */
3469 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3470 btrfs_ino(inode), &first_xattr_slot);
3471 if (first_xattr_slot != -1) {
3472 path->slots[0] = first_xattr_slot;
3473 ret = btrfs_load_inode_props(inode, path);
3474 if (ret)
3475 btrfs_err(root->fs_info,
3476 "error loading props for ino %llu (root %llu): %d\n",
3477 btrfs_ino(inode),
3478 root->root_key.objectid, ret);
3479 }
3480 btrfs_free_path(path);
3481
3482 if (!maybe_acls)
3483 cache_no_acl(inode);
3484
3485 switch (inode->i_mode & S_IFMT) {
3486 case S_IFREG:
3487 inode->i_mapping->a_ops = &btrfs_aops;
3488 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3489 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3490 inode->i_fop = &btrfs_file_operations;
3491 inode->i_op = &btrfs_file_inode_operations;
3492 break;
3493 case S_IFDIR:
3494 inode->i_fop = &btrfs_dir_file_operations;
3495 if (root == root->fs_info->tree_root)
3496 inode->i_op = &btrfs_dir_ro_inode_operations;
3497 else
3498 inode->i_op = &btrfs_dir_inode_operations;
3499 break;
3500 case S_IFLNK:
3501 inode->i_op = &btrfs_symlink_inode_operations;
3502 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3503 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3504 break;
3505 default:
3506 inode->i_op = &btrfs_special_inode_operations;
3507 init_special_inode(inode, inode->i_mode, rdev);
3508 break;
3509 }
3510
3511 btrfs_update_iflags(inode);
3512 return;
3513
3514 make_bad:
3515 btrfs_free_path(path);
3516 make_bad_inode(inode);
3517 }
3518
3519 /*
3520 * given a leaf and an inode, copy the inode fields into the leaf
3521 */
3522 static void fill_inode_item(struct btrfs_trans_handle *trans,
3523 struct extent_buffer *leaf,
3524 struct btrfs_inode_item *item,
3525 struct inode *inode)
3526 {
3527 struct btrfs_map_token token;
3528
3529 btrfs_init_map_token(&token);
3530
3531 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3532 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3533 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3534 &token);
3535 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3536 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3537
3538 btrfs_set_token_timespec_sec(leaf, btrfs_inode_atime(item),
3539 inode->i_atime.tv_sec, &token);
3540 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_atime(item),
3541 inode->i_atime.tv_nsec, &token);
3542
3543 btrfs_set_token_timespec_sec(leaf, btrfs_inode_mtime(item),
3544 inode->i_mtime.tv_sec, &token);
3545 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_mtime(item),
3546 inode->i_mtime.tv_nsec, &token);
3547
3548 btrfs_set_token_timespec_sec(leaf, btrfs_inode_ctime(item),
3549 inode->i_ctime.tv_sec, &token);
3550 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_ctime(item),
3551 inode->i_ctime.tv_nsec, &token);
3552
3553 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3554 &token);
3555 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3556 &token);
3557 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3558 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3559 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3560 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3561 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3562 }
3563
3564 /*
3565 * copy everything in the in-memory inode into the btree.
3566 */
3567 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3568 struct btrfs_root *root, struct inode *inode)
3569 {
3570 struct btrfs_inode_item *inode_item;
3571 struct btrfs_path *path;
3572 struct extent_buffer *leaf;
3573 int ret;
3574
3575 path = btrfs_alloc_path();
3576 if (!path)
3577 return -ENOMEM;
3578
3579 path->leave_spinning = 1;
3580 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3581 1);
3582 if (ret) {
3583 if (ret > 0)
3584 ret = -ENOENT;
3585 goto failed;
3586 }
3587
3588 leaf = path->nodes[0];
3589 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3590 struct btrfs_inode_item);
3591
3592 fill_inode_item(trans, leaf, inode_item, inode);
3593 btrfs_mark_buffer_dirty(leaf);
3594 btrfs_set_inode_last_trans(trans, inode);
3595 ret = 0;
3596 failed:
3597 btrfs_free_path(path);
3598 return ret;
3599 }
3600
3601 /*
3602 * copy everything in the in-memory inode into the btree.
3603 */
3604 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3605 struct btrfs_root *root, struct inode *inode)
3606 {
3607 int ret;
3608
3609 /*
3610 * If the inode is a free space inode, we can deadlock during commit
3611 * if we put it into the delayed code.
3612 *
3613 * The data relocation inode should also be directly updated
3614 * without delay
3615 */
3616 if (!btrfs_is_free_space_inode(inode)
3617 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) {
3618 btrfs_update_root_times(trans, root);
3619
3620 ret = btrfs_delayed_update_inode(trans, root, inode);
3621 if (!ret)
3622 btrfs_set_inode_last_trans(trans, inode);
3623 return ret;
3624 }
3625
3626 return btrfs_update_inode_item(trans, root, inode);
3627 }
3628
3629 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3630 struct btrfs_root *root,
3631 struct inode *inode)
3632 {
3633 int ret;
3634
3635 ret = btrfs_update_inode(trans, root, inode);
3636 if (ret == -ENOSPC)
3637 return btrfs_update_inode_item(trans, root, inode);
3638 return ret;
3639 }
3640
3641 /*
3642 * unlink helper that gets used here in inode.c and in the tree logging
3643 * recovery code. It remove a link in a directory with a given name, and
3644 * also drops the back refs in the inode to the directory
3645 */
3646 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3647 struct btrfs_root *root,
3648 struct inode *dir, struct inode *inode,
3649 const char *name, int name_len)
3650 {
3651 struct btrfs_path *path;
3652 int ret = 0;
3653 struct extent_buffer *leaf;
3654 struct btrfs_dir_item *di;
3655 struct btrfs_key key;
3656 u64 index;
3657 u64 ino = btrfs_ino(inode);
3658 u64 dir_ino = btrfs_ino(dir);
3659
3660 path = btrfs_alloc_path();
3661 if (!path) {
3662 ret = -ENOMEM;
3663 goto out;
3664 }
3665
3666 path->leave_spinning = 1;
3667 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3668 name, name_len, -1);
3669 if (IS_ERR(di)) {
3670 ret = PTR_ERR(di);
3671 goto err;
3672 }
3673 if (!di) {
3674 ret = -ENOENT;
3675 goto err;
3676 }
3677 leaf = path->nodes[0];
3678 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3679 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3680 if (ret)
3681 goto err;
3682 btrfs_release_path(path);
3683
3684 /*
3685 * If we don't have dir index, we have to get it by looking up
3686 * the inode ref, since we get the inode ref, remove it directly,
3687 * it is unnecessary to do delayed deletion.
3688 *
3689 * But if we have dir index, needn't search inode ref to get it.
3690 * Since the inode ref is close to the inode item, it is better
3691 * that we delay to delete it, and just do this deletion when
3692 * we update the inode item.
3693 */
3694 if (BTRFS_I(inode)->dir_index) {
3695 ret = btrfs_delayed_delete_inode_ref(inode);
3696 if (!ret) {
3697 index = BTRFS_I(inode)->dir_index;
3698 goto skip_backref;
3699 }
3700 }
3701
3702 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
3703 dir_ino, &index);
3704 if (ret) {
3705 btrfs_info(root->fs_info,
3706 "failed to delete reference to %.*s, inode %llu parent %llu",
3707 name_len, name, ino, dir_ino);
3708 btrfs_abort_transaction(trans, root, ret);
3709 goto err;
3710 }
3711 skip_backref:
3712 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3713 if (ret) {
3714 btrfs_abort_transaction(trans, root, ret);
3715 goto err;
3716 }
3717
3718 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
3719 inode, dir_ino);
3720 if (ret != 0 && ret != -ENOENT) {
3721 btrfs_abort_transaction(trans, root, ret);
3722 goto err;
3723 }
3724
3725 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
3726 dir, index);
3727 if (ret == -ENOENT)
3728 ret = 0;
3729 else if (ret)
3730 btrfs_abort_transaction(trans, root, ret);
3731 err:
3732 btrfs_free_path(path);
3733 if (ret)
3734 goto out;
3735
3736 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3737 inode_inc_iversion(inode);
3738 inode_inc_iversion(dir);
3739 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3740 ret = btrfs_update_inode(trans, root, dir);
3741 out:
3742 return ret;
3743 }
3744
3745 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3746 struct btrfs_root *root,
3747 struct inode *dir, struct inode *inode,
3748 const char *name, int name_len)
3749 {
3750 int ret;
3751 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
3752 if (!ret) {
3753 drop_nlink(inode);
3754 ret = btrfs_update_inode(trans, root, inode);
3755 }
3756 return ret;
3757 }
3758
3759 /*
3760 * helper to start transaction for unlink and rmdir.
3761 *
3762 * unlink and rmdir are special in btrfs, they do not always free space, so
3763 * if we cannot make our reservations the normal way try and see if there is
3764 * plenty of slack room in the global reserve to migrate, otherwise we cannot
3765 * allow the unlink to occur.
3766 */
3767 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
3768 {
3769 struct btrfs_trans_handle *trans;
3770 struct btrfs_root *root = BTRFS_I(dir)->root;
3771 int ret;
3772
3773 /*
3774 * 1 for the possible orphan item
3775 * 1 for the dir item
3776 * 1 for the dir index
3777 * 1 for the inode ref
3778 * 1 for the inode
3779 */
3780 trans = btrfs_start_transaction(root, 5);
3781 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
3782 return trans;
3783
3784 if (PTR_ERR(trans) == -ENOSPC) {
3785 u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5);
3786
3787 trans = btrfs_start_transaction(root, 0);
3788 if (IS_ERR(trans))
3789 return trans;
3790 ret = btrfs_cond_migrate_bytes(root->fs_info,
3791 &root->fs_info->trans_block_rsv,
3792 num_bytes, 5);
3793 if (ret) {
3794 btrfs_end_transaction(trans, root);
3795 return ERR_PTR(ret);
3796 }
3797 trans->block_rsv = &root->fs_info->trans_block_rsv;
3798 trans->bytes_reserved = num_bytes;
3799 }
3800 return trans;
3801 }
3802
3803 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
3804 {
3805 struct btrfs_root *root = BTRFS_I(dir)->root;
3806 struct btrfs_trans_handle *trans;
3807 struct inode *inode = dentry->d_inode;
3808 int ret;
3809
3810 trans = __unlink_start_trans(dir);
3811 if (IS_ERR(trans))
3812 return PTR_ERR(trans);
3813
3814 btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0);
3815
3816 ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3817 dentry->d_name.name, dentry->d_name.len);
3818 if (ret)
3819 goto out;
3820
3821 if (inode->i_nlink == 0) {
3822 ret = btrfs_orphan_add(trans, inode);
3823 if (ret)
3824 goto out;
3825 }
3826
3827 out:
3828 btrfs_end_transaction(trans, root);
3829 btrfs_btree_balance_dirty(root);
3830 return ret;
3831 }
3832
3833 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
3834 struct btrfs_root *root,
3835 struct inode *dir, u64 objectid,
3836 const char *name, int name_len)
3837 {
3838 struct btrfs_path *path;
3839 struct extent_buffer *leaf;
3840 struct btrfs_dir_item *di;
3841 struct btrfs_key key;
3842 u64 index;
3843 int ret;
3844 u64 dir_ino = btrfs_ino(dir);
3845
3846 path = btrfs_alloc_path();
3847 if (!path)
3848 return -ENOMEM;
3849
3850 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3851 name, name_len, -1);
3852 if (IS_ERR_OR_NULL(di)) {
3853 if (!di)
3854 ret = -ENOENT;
3855 else
3856 ret = PTR_ERR(di);
3857 goto out;
3858 }
3859
3860 leaf = path->nodes[0];
3861 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3862 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
3863 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3864 if (ret) {
3865 btrfs_abort_transaction(trans, root, ret);
3866 goto out;
3867 }
3868 btrfs_release_path(path);
3869
3870 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
3871 objectid, root->root_key.objectid,
3872 dir_ino, &index, name, name_len);
3873 if (ret < 0) {
3874 if (ret != -ENOENT) {
3875 btrfs_abort_transaction(trans, root, ret);
3876 goto out;
3877 }
3878 di = btrfs_search_dir_index_item(root, path, dir_ino,
3879 name, name_len);
3880 if (IS_ERR_OR_NULL(di)) {
3881 if (!di)
3882 ret = -ENOENT;
3883 else
3884 ret = PTR_ERR(di);
3885 btrfs_abort_transaction(trans, root, ret);
3886 goto out;
3887 }
3888
3889 leaf = path->nodes[0];
3890 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3891 btrfs_release_path(path);
3892 index = key.offset;
3893 }
3894 btrfs_release_path(path);
3895
3896 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3897 if (ret) {
3898 btrfs_abort_transaction(trans, root, ret);
3899 goto out;
3900 }
3901
3902 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3903 inode_inc_iversion(dir);
3904 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3905 ret = btrfs_update_inode_fallback(trans, root, dir);
3906 if (ret)
3907 btrfs_abort_transaction(trans, root, ret);
3908 out:
3909 btrfs_free_path(path);
3910 return ret;
3911 }
3912
3913 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
3914 {
3915 struct inode *inode = dentry->d_inode;
3916 int err = 0;
3917 struct btrfs_root *root = BTRFS_I(dir)->root;
3918 struct btrfs_trans_handle *trans;
3919
3920 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
3921 return -ENOTEMPTY;
3922 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
3923 return -EPERM;
3924
3925 trans = __unlink_start_trans(dir);
3926 if (IS_ERR(trans))
3927 return PTR_ERR(trans);
3928
3929 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
3930 err = btrfs_unlink_subvol(trans, root, dir,
3931 BTRFS_I(inode)->location.objectid,
3932 dentry->d_name.name,
3933 dentry->d_name.len);
3934 goto out;
3935 }
3936
3937 err = btrfs_orphan_add(trans, inode);
3938 if (err)
3939 goto out;
3940
3941 /* now the directory is empty */
3942 err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3943 dentry->d_name.name, dentry->d_name.len);
3944 if (!err)
3945 btrfs_i_size_write(inode, 0);
3946 out:
3947 btrfs_end_transaction(trans, root);
3948 btrfs_btree_balance_dirty(root);
3949
3950 return err;
3951 }
3952
3953 /*
3954 * this can truncate away extent items, csum items and directory items.
3955 * It starts at a high offset and removes keys until it can't find
3956 * any higher than new_size
3957 *
3958 * csum items that cross the new i_size are truncated to the new size
3959 * as well.
3960 *
3961 * min_type is the minimum key type to truncate down to. If set to 0, this
3962 * will kill all the items on this inode, including the INODE_ITEM_KEY.
3963 */
3964 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
3965 struct btrfs_root *root,
3966 struct inode *inode,
3967 u64 new_size, u32 min_type)
3968 {
3969 struct btrfs_path *path;
3970 struct extent_buffer *leaf;
3971 struct btrfs_file_extent_item *fi;
3972 struct btrfs_key key;
3973 struct btrfs_key found_key;
3974 u64 extent_start = 0;
3975 u64 extent_num_bytes = 0;
3976 u64 extent_offset = 0;
3977 u64 item_end = 0;
3978 u64 last_size = (u64)-1;
3979 u32 found_type = (u8)-1;
3980 int found_extent;
3981 int del_item;
3982 int pending_del_nr = 0;
3983 int pending_del_slot = 0;
3984 int extent_type = -1;
3985 int ret;
3986 int err = 0;
3987 u64 ino = btrfs_ino(inode);
3988
3989 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
3990
3991 path = btrfs_alloc_path();
3992 if (!path)
3993 return -ENOMEM;
3994 path->reada = -1;
3995
3996 /*
3997 * We want to drop from the next block forward in case this new size is
3998 * not block aligned since we will be keeping the last block of the
3999 * extent just the way it is.
4000 */
4001 if (root->ref_cows || root == root->fs_info->tree_root)
4002 btrfs_drop_extent_cache(inode, ALIGN(new_size,
4003 root->sectorsize), (u64)-1, 0);
4004
4005 /*
4006 * This function is also used to drop the items in the log tree before
4007 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4008 * it is used to drop the loged items. So we shouldn't kill the delayed
4009 * items.
4010 */
4011 if (min_type == 0 && root == BTRFS_I(inode)->root)
4012 btrfs_kill_delayed_inode_items(inode);
4013
4014 key.objectid = ino;
4015 key.offset = (u64)-1;
4016 key.type = (u8)-1;
4017
4018 search_again:
4019 path->leave_spinning = 1;
4020 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4021 if (ret < 0) {
4022 err = ret;
4023 goto out;
4024 }
4025
4026 if (ret > 0) {
4027 /* there are no items in the tree for us to truncate, we're
4028 * done
4029 */
4030 if (path->slots[0] == 0)
4031 goto out;
4032 path->slots[0]--;
4033 }
4034
4035 while (1) {
4036 fi = NULL;
4037 leaf = path->nodes[0];
4038 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4039 found_type = btrfs_key_type(&found_key);
4040
4041 if (found_key.objectid != ino)
4042 break;
4043
4044 if (found_type < min_type)
4045 break;
4046
4047 item_end = found_key.offset;
4048 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4049 fi = btrfs_item_ptr(leaf, path->slots[0],
4050 struct btrfs_file_extent_item);
4051 extent_type = btrfs_file_extent_type(leaf, fi);
4052 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4053 item_end +=
4054 btrfs_file_extent_num_bytes(leaf, fi);
4055 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4056 item_end += btrfs_file_extent_inline_len(leaf,
4057 path->slots[0], fi);
4058 }
4059 item_end--;
4060 }
4061 if (found_type > min_type) {
4062 del_item = 1;
4063 } else {
4064 if (item_end < new_size)
4065 break;
4066 if (found_key.offset >= new_size)
4067 del_item = 1;
4068 else
4069 del_item = 0;
4070 }
4071 found_extent = 0;
4072 /* FIXME, shrink the extent if the ref count is only 1 */
4073 if (found_type != BTRFS_EXTENT_DATA_KEY)
4074 goto delete;
4075
4076 if (del_item)
4077 last_size = found_key.offset;
4078 else
4079 last_size = new_size;
4080
4081 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4082 u64 num_dec;
4083 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4084 if (!del_item) {
4085 u64 orig_num_bytes =
4086 btrfs_file_extent_num_bytes(leaf, fi);
4087 extent_num_bytes = ALIGN(new_size -
4088 found_key.offset,
4089 root->sectorsize);
4090 btrfs_set_file_extent_num_bytes(leaf, fi,
4091 extent_num_bytes);
4092 num_dec = (orig_num_bytes -
4093 extent_num_bytes);
4094 if (root->ref_cows && extent_start != 0)
4095 inode_sub_bytes(inode, num_dec);
4096 btrfs_mark_buffer_dirty(leaf);
4097 } else {
4098 extent_num_bytes =
4099 btrfs_file_extent_disk_num_bytes(leaf,
4100 fi);
4101 extent_offset = found_key.offset -
4102 btrfs_file_extent_offset(leaf, fi);
4103
4104 /* FIXME blocksize != 4096 */
4105 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4106 if (extent_start != 0) {
4107 found_extent = 1;
4108 if (root->ref_cows)
4109 inode_sub_bytes(inode, num_dec);
4110 }
4111 }
4112 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4113 /*
4114 * we can't truncate inline items that have had
4115 * special encodings
4116 */
4117 if (!del_item &&
4118 btrfs_file_extent_compression(leaf, fi) == 0 &&
4119 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4120 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4121 u32 size = new_size - found_key.offset;
4122
4123 if (root->ref_cows) {
4124 inode_sub_bytes(inode, item_end + 1 -
4125 new_size);
4126 }
4127
4128 /*
4129 * update the ram bytes to properly reflect
4130 * the new size of our item
4131 */
4132 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4133 size =
4134 btrfs_file_extent_calc_inline_size(size);
4135 btrfs_truncate_item(root, path, size, 1);
4136 } else if (root->ref_cows) {
4137 inode_sub_bytes(inode, item_end + 1 -
4138 found_key.offset);
4139 }
4140 }
4141 delete:
4142 if (del_item) {
4143 if (!pending_del_nr) {
4144 /* no pending yet, add ourselves */
4145 pending_del_slot = path->slots[0];
4146 pending_del_nr = 1;
4147 } else if (pending_del_nr &&
4148 path->slots[0] + 1 == pending_del_slot) {
4149 /* hop on the pending chunk */
4150 pending_del_nr++;
4151 pending_del_slot = path->slots[0];
4152 } else {
4153 BUG();
4154 }
4155 } else {
4156 break;
4157 }
4158 if (found_extent && (root->ref_cows ||
4159 root == root->fs_info->tree_root)) {
4160 btrfs_set_path_blocking(path);
4161 ret = btrfs_free_extent(trans, root, extent_start,
4162 extent_num_bytes, 0,
4163 btrfs_header_owner(leaf),
4164 ino, extent_offset, 0);
4165 BUG_ON(ret);
4166 }
4167
4168 if (found_type == BTRFS_INODE_ITEM_KEY)
4169 break;
4170
4171 if (path->slots[0] == 0 ||
4172 path->slots[0] != pending_del_slot) {
4173 if (pending_del_nr) {
4174 ret = btrfs_del_items(trans, root, path,
4175 pending_del_slot,
4176 pending_del_nr);
4177 if (ret) {
4178 btrfs_abort_transaction(trans,
4179 root, ret);
4180 goto error;
4181 }
4182 pending_del_nr = 0;
4183 }
4184 btrfs_release_path(path);
4185 goto search_again;
4186 } else {
4187 path->slots[0]--;
4188 }
4189 }
4190 out:
4191 if (pending_del_nr) {
4192 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4193 pending_del_nr);
4194 if (ret)
4195 btrfs_abort_transaction(trans, root, ret);
4196 }
4197 error:
4198 if (last_size != (u64)-1)
4199 btrfs_ordered_update_i_size(inode, last_size, NULL);
4200 btrfs_free_path(path);
4201 return err;
4202 }
4203
4204 /*
4205 * btrfs_truncate_page - read, zero a chunk and write a page
4206 * @inode - inode that we're zeroing
4207 * @from - the offset to start zeroing
4208 * @len - the length to zero, 0 to zero the entire range respective to the
4209 * offset
4210 * @front - zero up to the offset instead of from the offset on
4211 *
4212 * This will find the page for the "from" offset and cow the page and zero the
4213 * part we want to zero. This is used with truncate and hole punching.
4214 */
4215 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
4216 int front)
4217 {
4218 struct address_space *mapping = inode->i_mapping;
4219 struct btrfs_root *root = BTRFS_I(inode)->root;
4220 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4221 struct btrfs_ordered_extent *ordered;
4222 struct extent_state *cached_state = NULL;
4223 char *kaddr;
4224 u32 blocksize = root->sectorsize;
4225 pgoff_t index = from >> PAGE_CACHE_SHIFT;
4226 unsigned offset = from & (PAGE_CACHE_SIZE-1);
4227 struct page *page;
4228 gfp_t mask = btrfs_alloc_write_mask(mapping);
4229 int ret = 0;
4230 u64 page_start;
4231 u64 page_end;
4232
4233 if ((offset & (blocksize - 1)) == 0 &&
4234 (!len || ((len & (blocksize - 1)) == 0)))
4235 goto out;
4236 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
4237 if (ret)
4238 goto out;
4239
4240 again:
4241 page = find_or_create_page(mapping, index, mask);
4242 if (!page) {
4243 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4244 ret = -ENOMEM;
4245 goto out;
4246 }
4247
4248 page_start = page_offset(page);
4249 page_end = page_start + PAGE_CACHE_SIZE - 1;
4250
4251 if (!PageUptodate(page)) {
4252 ret = btrfs_readpage(NULL, page);
4253 lock_page(page);
4254 if (page->mapping != mapping) {
4255 unlock_page(page);
4256 page_cache_release(page);
4257 goto again;
4258 }
4259 if (!PageUptodate(page)) {
4260 ret = -EIO;
4261 goto out_unlock;
4262 }
4263 }
4264 wait_on_page_writeback(page);
4265
4266 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
4267 set_page_extent_mapped(page);
4268
4269 ordered = btrfs_lookup_ordered_extent(inode, page_start);
4270 if (ordered) {
4271 unlock_extent_cached(io_tree, page_start, page_end,
4272 &cached_state, GFP_NOFS);
4273 unlock_page(page);
4274 page_cache_release(page);
4275 btrfs_start_ordered_extent(inode, ordered, 1);
4276 btrfs_put_ordered_extent(ordered);
4277 goto again;
4278 }
4279
4280 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
4281 EXTENT_DIRTY | EXTENT_DELALLOC |
4282 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4283 0, 0, &cached_state, GFP_NOFS);
4284
4285 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
4286 &cached_state);
4287 if (ret) {
4288 unlock_extent_cached(io_tree, page_start, page_end,
4289 &cached_state, GFP_NOFS);
4290 goto out_unlock;
4291 }
4292
4293 if (offset != PAGE_CACHE_SIZE) {
4294 if (!len)
4295 len = PAGE_CACHE_SIZE - offset;
4296 kaddr = kmap(page);
4297 if (front)
4298 memset(kaddr, 0, offset);
4299 else
4300 memset(kaddr + offset, 0, len);
4301 flush_dcache_page(page);
4302 kunmap(page);
4303 }
4304 ClearPageChecked(page);
4305 set_page_dirty(page);
4306 unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
4307 GFP_NOFS);
4308
4309 out_unlock:
4310 if (ret)
4311 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4312 unlock_page(page);
4313 page_cache_release(page);
4314 out:
4315 return ret;
4316 }
4317
4318 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4319 u64 offset, u64 len)
4320 {
4321 struct btrfs_trans_handle *trans;
4322 int ret;
4323
4324 /*
4325 * Still need to make sure the inode looks like it's been updated so
4326 * that any holes get logged if we fsync.
4327 */
4328 if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) {
4329 BTRFS_I(inode)->last_trans = root->fs_info->generation;
4330 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4331 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4332 return 0;
4333 }
4334
4335 /*
4336 * 1 - for the one we're dropping
4337 * 1 - for the one we're adding
4338 * 1 - for updating the inode.
4339 */
4340 trans = btrfs_start_transaction(root, 3);
4341 if (IS_ERR(trans))
4342 return PTR_ERR(trans);
4343
4344 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4345 if (ret) {
4346 btrfs_abort_transaction(trans, root, ret);
4347 btrfs_end_transaction(trans, root);
4348 return ret;
4349 }
4350
4351 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
4352 0, 0, len, 0, len, 0, 0, 0);
4353 if (ret)
4354 btrfs_abort_transaction(trans, root, ret);
4355 else
4356 btrfs_update_inode(trans, root, inode);
4357 btrfs_end_transaction(trans, root);
4358 return ret;
4359 }
4360
4361 /*
4362 * This function puts in dummy file extents for the area we're creating a hole
4363 * for. So if we are truncating this file to a larger size we need to insert
4364 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4365 * the range between oldsize and size
4366 */
4367 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4368 {
4369 struct btrfs_root *root = BTRFS_I(inode)->root;
4370 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4371 struct extent_map *em = NULL;
4372 struct extent_state *cached_state = NULL;
4373 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4374 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4375 u64 block_end = ALIGN(size, root->sectorsize);
4376 u64 last_byte;
4377 u64 cur_offset;
4378 u64 hole_size;
4379 int err = 0;
4380
4381 /*
4382 * If our size started in the middle of a page we need to zero out the
4383 * rest of the page before we expand the i_size, otherwise we could
4384 * expose stale data.
4385 */
4386 err = btrfs_truncate_page(inode, oldsize, 0, 0);
4387 if (err)
4388 return err;
4389
4390 if (size <= hole_start)
4391 return 0;
4392
4393 while (1) {
4394 struct btrfs_ordered_extent *ordered;
4395
4396 lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
4397 &cached_state);
4398 ordered = btrfs_lookup_ordered_range(inode, hole_start,
4399 block_end - hole_start);
4400 if (!ordered)
4401 break;
4402 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4403 &cached_state, GFP_NOFS);
4404 btrfs_start_ordered_extent(inode, ordered, 1);
4405 btrfs_put_ordered_extent(ordered);
4406 }
4407
4408 cur_offset = hole_start;
4409 while (1) {
4410 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4411 block_end - cur_offset, 0);
4412 if (IS_ERR(em)) {
4413 err = PTR_ERR(em);
4414 em = NULL;
4415 break;
4416 }
4417 last_byte = min(extent_map_end(em), block_end);
4418 last_byte = ALIGN(last_byte , root->sectorsize);
4419 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4420 struct extent_map *hole_em;
4421 hole_size = last_byte - cur_offset;
4422
4423 err = maybe_insert_hole(root, inode, cur_offset,
4424 hole_size);
4425 if (err)
4426 break;
4427 btrfs_drop_extent_cache(inode, cur_offset,
4428 cur_offset + hole_size - 1, 0);
4429 hole_em = alloc_extent_map();
4430 if (!hole_em) {
4431 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4432 &BTRFS_I(inode)->runtime_flags);
4433 goto next;
4434 }
4435 hole_em->start = cur_offset;
4436 hole_em->len = hole_size;
4437 hole_em->orig_start = cur_offset;
4438
4439 hole_em->block_start = EXTENT_MAP_HOLE;
4440 hole_em->block_len = 0;
4441 hole_em->orig_block_len = 0;
4442 hole_em->ram_bytes = hole_size;
4443 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4444 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4445 hole_em->generation = root->fs_info->generation;
4446
4447 while (1) {
4448 write_lock(&em_tree->lock);
4449 err = add_extent_mapping(em_tree, hole_em, 1);
4450 write_unlock(&em_tree->lock);
4451 if (err != -EEXIST)
4452 break;
4453 btrfs_drop_extent_cache(inode, cur_offset,
4454 cur_offset +
4455 hole_size - 1, 0);
4456 }
4457 free_extent_map(hole_em);
4458 }
4459 next:
4460 free_extent_map(em);
4461 em = NULL;
4462 cur_offset = last_byte;
4463 if (cur_offset >= block_end)
4464 break;
4465 }
4466 free_extent_map(em);
4467 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4468 GFP_NOFS);
4469 return err;
4470 }
4471
4472 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4473 {
4474 struct btrfs_root *root = BTRFS_I(inode)->root;
4475 struct btrfs_trans_handle *trans;
4476 loff_t oldsize = i_size_read(inode);
4477 loff_t newsize = attr->ia_size;
4478 int mask = attr->ia_valid;
4479 int ret;
4480
4481 /*
4482 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4483 * special case where we need to update the times despite not having
4484 * these flags set. For all other operations the VFS set these flags
4485 * explicitly if it wants a timestamp update.
4486 */
4487 if (newsize != oldsize) {
4488 inode_inc_iversion(inode);
4489 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
4490 inode->i_ctime = inode->i_mtime =
4491 current_fs_time(inode->i_sb);
4492 }
4493
4494 if (newsize > oldsize) {
4495 truncate_pagecache(inode, newsize);
4496 ret = btrfs_cont_expand(inode, oldsize, newsize);
4497 if (ret)
4498 return ret;
4499
4500 trans = btrfs_start_transaction(root, 1);
4501 if (IS_ERR(trans))
4502 return PTR_ERR(trans);
4503
4504 i_size_write(inode, newsize);
4505 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4506 ret = btrfs_update_inode(trans, root, inode);
4507 btrfs_end_transaction(trans, root);
4508 } else {
4509
4510 /*
4511 * We're truncating a file that used to have good data down to
4512 * zero. Make sure it gets into the ordered flush list so that
4513 * any new writes get down to disk quickly.
4514 */
4515 if (newsize == 0)
4516 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
4517 &BTRFS_I(inode)->runtime_flags);
4518
4519 /*
4520 * 1 for the orphan item we're going to add
4521 * 1 for the orphan item deletion.
4522 */
4523 trans = btrfs_start_transaction(root, 2);
4524 if (IS_ERR(trans))
4525 return PTR_ERR(trans);
4526
4527 /*
4528 * We need to do this in case we fail at _any_ point during the
4529 * actual truncate. Once we do the truncate_setsize we could
4530 * invalidate pages which forces any outstanding ordered io to
4531 * be instantly completed which will give us extents that need
4532 * to be truncated. If we fail to get an orphan inode down we
4533 * could have left over extents that were never meant to live,
4534 * so we need to garuntee from this point on that everything
4535 * will be consistent.
4536 */
4537 ret = btrfs_orphan_add(trans, inode);
4538 btrfs_end_transaction(trans, root);
4539 if (ret)
4540 return ret;
4541
4542 /* we don't support swapfiles, so vmtruncate shouldn't fail */
4543 truncate_setsize(inode, newsize);
4544
4545 /* Disable nonlocked read DIO to avoid the end less truncate */
4546 btrfs_inode_block_unlocked_dio(inode);
4547 inode_dio_wait(inode);
4548 btrfs_inode_resume_unlocked_dio(inode);
4549
4550 ret = btrfs_truncate(inode);
4551 if (ret && inode->i_nlink) {
4552 int err;
4553
4554 /*
4555 * failed to truncate, disk_i_size is only adjusted down
4556 * as we remove extents, so it should represent the true
4557 * size of the inode, so reset the in memory size and
4558 * delete our orphan entry.
4559 */
4560 trans = btrfs_join_transaction(root);
4561 if (IS_ERR(trans)) {
4562 btrfs_orphan_del(NULL, inode);
4563 return ret;
4564 }
4565 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
4566 err = btrfs_orphan_del(trans, inode);
4567 if (err)
4568 btrfs_abort_transaction(trans, root, err);
4569 btrfs_end_transaction(trans, root);
4570 }
4571 }
4572
4573 return ret;
4574 }
4575
4576 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
4577 {
4578 struct inode *inode = dentry->d_inode;
4579 struct btrfs_root *root = BTRFS_I(inode)->root;
4580 int err;
4581
4582 if (btrfs_root_readonly(root))
4583 return -EROFS;
4584
4585 err = inode_change_ok(inode, attr);
4586 if (err)
4587 return err;
4588
4589 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
4590 err = btrfs_setsize(inode, attr);
4591 if (err)
4592 return err;
4593 }
4594
4595 if (attr->ia_valid) {
4596 setattr_copy(inode, attr);
4597 inode_inc_iversion(inode);
4598 err = btrfs_dirty_inode(inode);
4599
4600 if (!err && attr->ia_valid & ATTR_MODE)
4601 err = posix_acl_chmod(inode, inode->i_mode);
4602 }
4603
4604 return err;
4605 }
4606
4607 /*
4608 * While truncating the inode pages during eviction, we get the VFS calling
4609 * btrfs_invalidatepage() against each page of the inode. This is slow because
4610 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
4611 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
4612 * extent_state structures over and over, wasting lots of time.
4613 *
4614 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
4615 * those expensive operations on a per page basis and do only the ordered io
4616 * finishing, while we release here the extent_map and extent_state structures,
4617 * without the excessive merging and splitting.
4618 */
4619 static void evict_inode_truncate_pages(struct inode *inode)
4620 {
4621 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4622 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
4623 struct rb_node *node;
4624
4625 ASSERT(inode->i_state & I_FREEING);
4626 truncate_inode_pages_final(&inode->i_data);
4627
4628 write_lock(&map_tree->lock);
4629 while (!RB_EMPTY_ROOT(&map_tree->map)) {
4630 struct extent_map *em;
4631
4632 node = rb_first(&map_tree->map);
4633 em = rb_entry(node, struct extent_map, rb_node);
4634 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
4635 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
4636 remove_extent_mapping(map_tree, em);
4637 free_extent_map(em);
4638 }
4639 write_unlock(&map_tree->lock);
4640
4641 spin_lock(&io_tree->lock);
4642 while (!RB_EMPTY_ROOT(&io_tree->state)) {
4643 struct extent_state *state;
4644 struct extent_state *cached_state = NULL;
4645
4646 node = rb_first(&io_tree->state);
4647 state = rb_entry(node, struct extent_state, rb_node);
4648 atomic_inc(&state->refs);
4649 spin_unlock(&io_tree->lock);
4650
4651 lock_extent_bits(io_tree, state->start, state->end,
4652 0, &cached_state);
4653 clear_extent_bit(io_tree, state->start, state->end,
4654 EXTENT_LOCKED | EXTENT_DIRTY |
4655 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
4656 EXTENT_DEFRAG, 1, 1,
4657 &cached_state, GFP_NOFS);
4658 free_extent_state(state);
4659
4660 spin_lock(&io_tree->lock);
4661 }
4662 spin_unlock(&io_tree->lock);
4663 }
4664
4665 void btrfs_evict_inode(struct inode *inode)
4666 {
4667 struct btrfs_trans_handle *trans;
4668 struct btrfs_root *root = BTRFS_I(inode)->root;
4669 struct btrfs_block_rsv *rsv, *global_rsv;
4670 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
4671 int ret;
4672
4673 trace_btrfs_inode_evict(inode);
4674
4675 evict_inode_truncate_pages(inode);
4676
4677 if (inode->i_nlink &&
4678 ((btrfs_root_refs(&root->root_item) != 0 &&
4679 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
4680 btrfs_is_free_space_inode(inode)))
4681 goto no_delete;
4682
4683 if (is_bad_inode(inode)) {
4684 btrfs_orphan_del(NULL, inode);
4685 goto no_delete;
4686 }
4687 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
4688 btrfs_wait_ordered_range(inode, 0, (u64)-1);
4689
4690 if (root->fs_info->log_root_recovering) {
4691 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
4692 &BTRFS_I(inode)->runtime_flags));
4693 goto no_delete;
4694 }
4695
4696 if (inode->i_nlink > 0) {
4697 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
4698 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
4699 goto no_delete;
4700 }
4701
4702 ret = btrfs_commit_inode_delayed_inode(inode);
4703 if (ret) {
4704 btrfs_orphan_del(NULL, inode);
4705 goto no_delete;
4706 }
4707
4708 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
4709 if (!rsv) {
4710 btrfs_orphan_del(NULL, inode);
4711 goto no_delete;
4712 }
4713 rsv->size = min_size;
4714 rsv->failfast = 1;
4715 global_rsv = &root->fs_info->global_block_rsv;
4716
4717 btrfs_i_size_write(inode, 0);
4718
4719 /*
4720 * This is a bit simpler than btrfs_truncate since we've already
4721 * reserved our space for our orphan item in the unlink, so we just
4722 * need to reserve some slack space in case we add bytes and update
4723 * inode item when doing the truncate.
4724 */
4725 while (1) {
4726 ret = btrfs_block_rsv_refill(root, rsv, min_size,
4727 BTRFS_RESERVE_FLUSH_LIMIT);
4728
4729 /*
4730 * Try and steal from the global reserve since we will
4731 * likely not use this space anyway, we want to try as
4732 * hard as possible to get this to work.
4733 */
4734 if (ret)
4735 ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size);
4736
4737 if (ret) {
4738 btrfs_warn(root->fs_info,
4739 "Could not get space for a delete, will truncate on mount %d",
4740 ret);
4741 btrfs_orphan_del(NULL, inode);
4742 btrfs_free_block_rsv(root, rsv);
4743 goto no_delete;
4744 }
4745
4746 trans = btrfs_join_transaction(root);
4747 if (IS_ERR(trans)) {
4748 btrfs_orphan_del(NULL, inode);
4749 btrfs_free_block_rsv(root, rsv);
4750 goto no_delete;
4751 }
4752
4753 trans->block_rsv = rsv;
4754
4755 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
4756 if (ret != -ENOSPC)
4757 break;
4758
4759 trans->block_rsv = &root->fs_info->trans_block_rsv;
4760 btrfs_end_transaction(trans, root);
4761 trans = NULL;
4762 btrfs_btree_balance_dirty(root);
4763 }
4764
4765 btrfs_free_block_rsv(root, rsv);
4766
4767 /*
4768 * Errors here aren't a big deal, it just means we leave orphan items
4769 * in the tree. They will be cleaned up on the next mount.
4770 */
4771 if (ret == 0) {
4772 trans->block_rsv = root->orphan_block_rsv;
4773 btrfs_orphan_del(trans, inode);
4774 } else {
4775 btrfs_orphan_del(NULL, inode);
4776 }
4777
4778 trans->block_rsv = &root->fs_info->trans_block_rsv;
4779 if (!(root == root->fs_info->tree_root ||
4780 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
4781 btrfs_return_ino(root, btrfs_ino(inode));
4782
4783 btrfs_end_transaction(trans, root);
4784 btrfs_btree_balance_dirty(root);
4785 no_delete:
4786 btrfs_remove_delayed_node(inode);
4787 clear_inode(inode);
4788 return;
4789 }
4790
4791 /*
4792 * this returns the key found in the dir entry in the location pointer.
4793 * If no dir entries were found, location->objectid is 0.
4794 */
4795 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
4796 struct btrfs_key *location)
4797 {
4798 const char *name = dentry->d_name.name;
4799 int namelen = dentry->d_name.len;
4800 struct btrfs_dir_item *di;
4801 struct btrfs_path *path;
4802 struct btrfs_root *root = BTRFS_I(dir)->root;
4803 int ret = 0;
4804
4805 path = btrfs_alloc_path();
4806 if (!path)
4807 return -ENOMEM;
4808
4809 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
4810 namelen, 0);
4811 if (IS_ERR(di))
4812 ret = PTR_ERR(di);
4813
4814 if (IS_ERR_OR_NULL(di))
4815 goto out_err;
4816
4817 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
4818 out:
4819 btrfs_free_path(path);
4820 return ret;
4821 out_err:
4822 location->objectid = 0;
4823 goto out;
4824 }
4825
4826 /*
4827 * when we hit a tree root in a directory, the btrfs part of the inode
4828 * needs to be changed to reflect the root directory of the tree root. This
4829 * is kind of like crossing a mount point.
4830 */
4831 static int fixup_tree_root_location(struct btrfs_root *root,
4832 struct inode *dir,
4833 struct dentry *dentry,
4834 struct btrfs_key *location,
4835 struct btrfs_root **sub_root)
4836 {
4837 struct btrfs_path *path;
4838 struct btrfs_root *new_root;
4839 struct btrfs_root_ref *ref;
4840 struct extent_buffer *leaf;
4841 int ret;
4842 int err = 0;
4843
4844 path = btrfs_alloc_path();
4845 if (!path) {
4846 err = -ENOMEM;
4847 goto out;
4848 }
4849
4850 err = -ENOENT;
4851 ret = btrfs_find_item(root->fs_info->tree_root, path,
4852 BTRFS_I(dir)->root->root_key.objectid,
4853 location->objectid, BTRFS_ROOT_REF_KEY, NULL);
4854 if (ret) {
4855 if (ret < 0)
4856 err = ret;
4857 goto out;
4858 }
4859
4860 leaf = path->nodes[0];
4861 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
4862 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
4863 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
4864 goto out;
4865
4866 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
4867 (unsigned long)(ref + 1),
4868 dentry->d_name.len);
4869 if (ret)
4870 goto out;
4871
4872 btrfs_release_path(path);
4873
4874 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
4875 if (IS_ERR(new_root)) {
4876 err = PTR_ERR(new_root);
4877 goto out;
4878 }
4879
4880 *sub_root = new_root;
4881 location->objectid = btrfs_root_dirid(&new_root->root_item);
4882 location->type = BTRFS_INODE_ITEM_KEY;
4883 location->offset = 0;
4884 err = 0;
4885 out:
4886 btrfs_free_path(path);
4887 return err;
4888 }
4889
4890 static void inode_tree_add(struct inode *inode)
4891 {
4892 struct btrfs_root *root = BTRFS_I(inode)->root;
4893 struct btrfs_inode *entry;
4894 struct rb_node **p;
4895 struct rb_node *parent;
4896 struct rb_node *new = &BTRFS_I(inode)->rb_node;
4897 u64 ino = btrfs_ino(inode);
4898
4899 if (inode_unhashed(inode))
4900 return;
4901 parent = NULL;
4902 spin_lock(&root->inode_lock);
4903 p = &root->inode_tree.rb_node;
4904 while (*p) {
4905 parent = *p;
4906 entry = rb_entry(parent, struct btrfs_inode, rb_node);
4907
4908 if (ino < btrfs_ino(&entry->vfs_inode))
4909 p = &parent->rb_left;
4910 else if (ino > btrfs_ino(&entry->vfs_inode))
4911 p = &parent->rb_right;
4912 else {
4913 WARN_ON(!(entry->vfs_inode.i_state &
4914 (I_WILL_FREE | I_FREEING)));
4915 rb_replace_node(parent, new, &root->inode_tree);
4916 RB_CLEAR_NODE(parent);
4917 spin_unlock(&root->inode_lock);
4918 return;
4919 }
4920 }
4921 rb_link_node(new, parent, p);
4922 rb_insert_color(new, &root->inode_tree);
4923 spin_unlock(&root->inode_lock);
4924 }
4925
4926 static void inode_tree_del(struct inode *inode)
4927 {
4928 struct btrfs_root *root = BTRFS_I(inode)->root;
4929 int empty = 0;
4930
4931 spin_lock(&root->inode_lock);
4932 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
4933 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
4934 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
4935 empty = RB_EMPTY_ROOT(&root->inode_tree);
4936 }
4937 spin_unlock(&root->inode_lock);
4938
4939 if (empty && btrfs_root_refs(&root->root_item) == 0) {
4940 synchronize_srcu(&root->fs_info->subvol_srcu);
4941 spin_lock(&root->inode_lock);
4942 empty = RB_EMPTY_ROOT(&root->inode_tree);
4943 spin_unlock(&root->inode_lock);
4944 if (empty)
4945 btrfs_add_dead_root(root);
4946 }
4947 }
4948
4949 void btrfs_invalidate_inodes(struct btrfs_root *root)
4950 {
4951 struct rb_node *node;
4952 struct rb_node *prev;
4953 struct btrfs_inode *entry;
4954 struct inode *inode;
4955 u64 objectid = 0;
4956
4957 if (!test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
4958 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
4959
4960 spin_lock(&root->inode_lock);
4961 again:
4962 node = root->inode_tree.rb_node;
4963 prev = NULL;
4964 while (node) {
4965 prev = node;
4966 entry = rb_entry(node, struct btrfs_inode, rb_node);
4967
4968 if (objectid < btrfs_ino(&entry->vfs_inode))
4969 node = node->rb_left;
4970 else if (objectid > btrfs_ino(&entry->vfs_inode))
4971 node = node->rb_right;
4972 else
4973 break;
4974 }
4975 if (!node) {
4976 while (prev) {
4977 entry = rb_entry(prev, struct btrfs_inode, rb_node);
4978 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
4979 node = prev;
4980 break;
4981 }
4982 prev = rb_next(prev);
4983 }
4984 }
4985 while (node) {
4986 entry = rb_entry(node, struct btrfs_inode, rb_node);
4987 objectid = btrfs_ino(&entry->vfs_inode) + 1;
4988 inode = igrab(&entry->vfs_inode);
4989 if (inode) {
4990 spin_unlock(&root->inode_lock);
4991 if (atomic_read(&inode->i_count) > 1)
4992 d_prune_aliases(inode);
4993 /*
4994 * btrfs_drop_inode will have it removed from
4995 * the inode cache when its usage count
4996 * hits zero.
4997 */
4998 iput(inode);
4999 cond_resched();
5000 spin_lock(&root->inode_lock);
5001 goto again;
5002 }
5003
5004 if (cond_resched_lock(&root->inode_lock))
5005 goto again;
5006
5007 node = rb_next(node);
5008 }
5009 spin_unlock(&root->inode_lock);
5010 }
5011
5012 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5013 {
5014 struct btrfs_iget_args *args = p;
5015 inode->i_ino = args->location->objectid;
5016 memcpy(&BTRFS_I(inode)->location, args->location,
5017 sizeof(*args->location));
5018 BTRFS_I(inode)->root = args->root;
5019 return 0;
5020 }
5021
5022 static int btrfs_find_actor(struct inode *inode, void *opaque)
5023 {
5024 struct btrfs_iget_args *args = opaque;
5025 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5026 args->root == BTRFS_I(inode)->root;
5027 }
5028
5029 static struct inode *btrfs_iget_locked(struct super_block *s,
5030 struct btrfs_key *location,
5031 struct btrfs_root *root)
5032 {
5033 struct inode *inode;
5034 struct btrfs_iget_args args;
5035 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5036
5037 args.location = location;
5038 args.root = root;
5039
5040 inode = iget5_locked(s, hashval, btrfs_find_actor,
5041 btrfs_init_locked_inode,
5042 (void *)&args);
5043 return inode;
5044 }
5045
5046 /* Get an inode object given its location and corresponding root.
5047 * Returns in *is_new if the inode was read from disk
5048 */
5049 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5050 struct btrfs_root *root, int *new)
5051 {
5052 struct inode *inode;
5053
5054 inode = btrfs_iget_locked(s, location, root);
5055 if (!inode)
5056 return ERR_PTR(-ENOMEM);
5057
5058 if (inode->i_state & I_NEW) {
5059 btrfs_read_locked_inode(inode);
5060 if (!is_bad_inode(inode)) {
5061 inode_tree_add(inode);
5062 unlock_new_inode(inode);
5063 if (new)
5064 *new = 1;
5065 } else {
5066 unlock_new_inode(inode);
5067 iput(inode);
5068 inode = ERR_PTR(-ESTALE);
5069 }
5070 }
5071
5072 return inode;
5073 }
5074
5075 static struct inode *new_simple_dir(struct super_block *s,
5076 struct btrfs_key *key,
5077 struct btrfs_root *root)
5078 {
5079 struct inode *inode = new_inode(s);
5080
5081 if (!inode)
5082 return ERR_PTR(-ENOMEM);
5083
5084 BTRFS_I(inode)->root = root;
5085 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5086 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5087
5088 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5089 inode->i_op = &btrfs_dir_ro_inode_operations;
5090 inode->i_fop = &simple_dir_operations;
5091 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5092 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
5093
5094 return inode;
5095 }
5096
5097 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5098 {
5099 struct inode *inode;
5100 struct btrfs_root *root = BTRFS_I(dir)->root;
5101 struct btrfs_root *sub_root = root;
5102 struct btrfs_key location;
5103 int index;
5104 int ret = 0;
5105
5106 if (dentry->d_name.len > BTRFS_NAME_LEN)
5107 return ERR_PTR(-ENAMETOOLONG);
5108
5109 ret = btrfs_inode_by_name(dir, dentry, &location);
5110 if (ret < 0)
5111 return ERR_PTR(ret);
5112
5113 if (location.objectid == 0)
5114 return ERR_PTR(-ENOENT);
5115
5116 if (location.type == BTRFS_INODE_ITEM_KEY) {
5117 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5118 return inode;
5119 }
5120
5121 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5122
5123 index = srcu_read_lock(&root->fs_info->subvol_srcu);
5124 ret = fixup_tree_root_location(root, dir, dentry,
5125 &location, &sub_root);
5126 if (ret < 0) {
5127 if (ret != -ENOENT)
5128 inode = ERR_PTR(ret);
5129 else
5130 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5131 } else {
5132 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5133 }
5134 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
5135
5136 if (!IS_ERR(inode) && root != sub_root) {
5137 down_read(&root->fs_info->cleanup_work_sem);
5138 if (!(inode->i_sb->s_flags & MS_RDONLY))
5139 ret = btrfs_orphan_cleanup(sub_root);
5140 up_read(&root->fs_info->cleanup_work_sem);
5141 if (ret) {
5142 iput(inode);
5143 inode = ERR_PTR(ret);
5144 }
5145 }
5146
5147 return inode;
5148 }
5149
5150 static int btrfs_dentry_delete(const struct dentry *dentry)
5151 {
5152 struct btrfs_root *root;
5153 struct inode *inode = dentry->d_inode;
5154
5155 if (!inode && !IS_ROOT(dentry))
5156 inode = dentry->d_parent->d_inode;
5157
5158 if (inode) {
5159 root = BTRFS_I(inode)->root;
5160 if (btrfs_root_refs(&root->root_item) == 0)
5161 return 1;
5162
5163 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5164 return 1;
5165 }
5166 return 0;
5167 }
5168
5169 static void btrfs_dentry_release(struct dentry *dentry)
5170 {
5171 if (dentry->d_fsdata)
5172 kfree(dentry->d_fsdata);
5173 }
5174
5175 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5176 unsigned int flags)
5177 {
5178 struct inode *inode;
5179
5180 inode = btrfs_lookup_dentry(dir, dentry);
5181 if (IS_ERR(inode)) {
5182 if (PTR_ERR(inode) == -ENOENT)
5183 inode = NULL;
5184 else
5185 return ERR_CAST(inode);
5186 }
5187
5188 return d_materialise_unique(dentry, inode);
5189 }
5190
5191 unsigned char btrfs_filetype_table[] = {
5192 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5193 };
5194
5195 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5196 {
5197 struct inode *inode = file_inode(file);
5198 struct btrfs_root *root = BTRFS_I(inode)->root;
5199 struct btrfs_item *item;
5200 struct btrfs_dir_item *di;
5201 struct btrfs_key key;
5202 struct btrfs_key found_key;
5203 struct btrfs_path *path;
5204 struct list_head ins_list;
5205 struct list_head del_list;
5206 int ret;
5207 struct extent_buffer *leaf;
5208 int slot;
5209 unsigned char d_type;
5210 int over = 0;
5211 u32 di_cur;
5212 u32 di_total;
5213 u32 di_len;
5214 int key_type = BTRFS_DIR_INDEX_KEY;
5215 char tmp_name[32];
5216 char *name_ptr;
5217 int name_len;
5218 int is_curr = 0; /* ctx->pos points to the current index? */
5219
5220 /* FIXME, use a real flag for deciding about the key type */
5221 if (root->fs_info->tree_root == root)
5222 key_type = BTRFS_DIR_ITEM_KEY;
5223
5224 if (!dir_emit_dots(file, ctx))
5225 return 0;
5226
5227 path = btrfs_alloc_path();
5228 if (!path)
5229 return -ENOMEM;
5230
5231 path->reada = 1;
5232
5233 if (key_type == BTRFS_DIR_INDEX_KEY) {
5234 INIT_LIST_HEAD(&ins_list);
5235 INIT_LIST_HEAD(&del_list);
5236 btrfs_get_delayed_items(inode, &ins_list, &del_list);
5237 }
5238
5239 btrfs_set_key_type(&key, key_type);
5240 key.offset = ctx->pos;
5241 key.objectid = btrfs_ino(inode);
5242
5243 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5244 if (ret < 0)
5245 goto err;
5246
5247 while (1) {
5248 leaf = path->nodes[0];
5249 slot = path->slots[0];
5250 if (slot >= btrfs_header_nritems(leaf)) {
5251 ret = btrfs_next_leaf(root, path);
5252 if (ret < 0)
5253 goto err;
5254 else if (ret > 0)
5255 break;
5256 continue;
5257 }
5258
5259 item = btrfs_item_nr(slot);
5260 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5261
5262 if (found_key.objectid != key.objectid)
5263 break;
5264 if (btrfs_key_type(&found_key) != key_type)
5265 break;
5266 if (found_key.offset < ctx->pos)
5267 goto next;
5268 if (key_type == BTRFS_DIR_INDEX_KEY &&
5269 btrfs_should_delete_dir_index(&del_list,
5270 found_key.offset))
5271 goto next;
5272
5273 ctx->pos = found_key.offset;
5274 is_curr = 1;
5275
5276 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5277 di_cur = 0;
5278 di_total = btrfs_item_size(leaf, item);
5279
5280 while (di_cur < di_total) {
5281 struct btrfs_key location;
5282
5283 if (verify_dir_item(root, leaf, di))
5284 break;
5285
5286 name_len = btrfs_dir_name_len(leaf, di);
5287 if (name_len <= sizeof(tmp_name)) {
5288 name_ptr = tmp_name;
5289 } else {
5290 name_ptr = kmalloc(name_len, GFP_NOFS);
5291 if (!name_ptr) {
5292 ret = -ENOMEM;
5293 goto err;
5294 }
5295 }
5296 read_extent_buffer(leaf, name_ptr,
5297 (unsigned long)(di + 1), name_len);
5298
5299 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5300 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5301
5302
5303 /* is this a reference to our own snapshot? If so
5304 * skip it.
5305 *
5306 * In contrast to old kernels, we insert the snapshot's
5307 * dir item and dir index after it has been created, so
5308 * we won't find a reference to our own snapshot. We
5309 * still keep the following code for backward
5310 * compatibility.
5311 */
5312 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5313 location.objectid == root->root_key.objectid) {
5314 over = 0;
5315 goto skip;
5316 }
5317 over = !dir_emit(ctx, name_ptr, name_len,
5318 location.objectid, d_type);
5319
5320 skip:
5321 if (name_ptr != tmp_name)
5322 kfree(name_ptr);
5323
5324 if (over)
5325 goto nopos;
5326 di_len = btrfs_dir_name_len(leaf, di) +
5327 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5328 di_cur += di_len;
5329 di = (struct btrfs_dir_item *)((char *)di + di_len);
5330 }
5331 next:
5332 path->slots[0]++;
5333 }
5334
5335 if (key_type == BTRFS_DIR_INDEX_KEY) {
5336 if (is_curr)
5337 ctx->pos++;
5338 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
5339 if (ret)
5340 goto nopos;
5341 }
5342
5343 /* Reached end of directory/root. Bump pos past the last item. */
5344 ctx->pos++;
5345
5346 /*
5347 * Stop new entries from being returned after we return the last
5348 * entry.
5349 *
5350 * New directory entries are assigned a strictly increasing
5351 * offset. This means that new entries created during readdir
5352 * are *guaranteed* to be seen in the future by that readdir.
5353 * This has broken buggy programs which operate on names as
5354 * they're returned by readdir. Until we re-use freed offsets
5355 * we have this hack to stop new entries from being returned
5356 * under the assumption that they'll never reach this huge
5357 * offset.
5358 *
5359 * This is being careful not to overflow 32bit loff_t unless the
5360 * last entry requires it because doing so has broken 32bit apps
5361 * in the past.
5362 */
5363 if (key_type == BTRFS_DIR_INDEX_KEY) {
5364 if (ctx->pos >= INT_MAX)
5365 ctx->pos = LLONG_MAX;
5366 else
5367 ctx->pos = INT_MAX;
5368 }
5369 nopos:
5370 ret = 0;
5371 err:
5372 if (key_type == BTRFS_DIR_INDEX_KEY)
5373 btrfs_put_delayed_items(&ins_list, &del_list);
5374 btrfs_free_path(path);
5375 return ret;
5376 }
5377
5378 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5379 {
5380 struct btrfs_root *root = BTRFS_I(inode)->root;
5381 struct btrfs_trans_handle *trans;
5382 int ret = 0;
5383 bool nolock = false;
5384
5385 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5386 return 0;
5387
5388 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5389 nolock = true;
5390
5391 if (wbc->sync_mode == WB_SYNC_ALL) {
5392 if (nolock)
5393 trans = btrfs_join_transaction_nolock(root);
5394 else
5395 trans = btrfs_join_transaction(root);
5396 if (IS_ERR(trans))
5397 return PTR_ERR(trans);
5398 ret = btrfs_commit_transaction(trans, root);
5399 }
5400 return ret;
5401 }
5402
5403 /*
5404 * This is somewhat expensive, updating the tree every time the
5405 * inode changes. But, it is most likely to find the inode in cache.
5406 * FIXME, needs more benchmarking...there are no reasons other than performance
5407 * to keep or drop this code.
5408 */
5409 static int btrfs_dirty_inode(struct inode *inode)
5410 {
5411 struct btrfs_root *root = BTRFS_I(inode)->root;
5412 struct btrfs_trans_handle *trans;
5413 int ret;
5414
5415 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5416 return 0;
5417
5418 trans = btrfs_join_transaction(root);
5419 if (IS_ERR(trans))
5420 return PTR_ERR(trans);
5421
5422 ret = btrfs_update_inode(trans, root, inode);
5423 if (ret && ret == -ENOSPC) {
5424 /* whoops, lets try again with the full transaction */
5425 btrfs_end_transaction(trans, root);
5426 trans = btrfs_start_transaction(root, 1);
5427 if (IS_ERR(trans))
5428 return PTR_ERR(trans);
5429
5430 ret = btrfs_update_inode(trans, root, inode);
5431 }
5432 btrfs_end_transaction(trans, root);
5433 if (BTRFS_I(inode)->delayed_node)
5434 btrfs_balance_delayed_items(root);
5435
5436 return ret;
5437 }
5438
5439 /*
5440 * This is a copy of file_update_time. We need this so we can return error on
5441 * ENOSPC for updating the inode in the case of file write and mmap writes.
5442 */
5443 static int btrfs_update_time(struct inode *inode, struct timespec *now,
5444 int flags)
5445 {
5446 struct btrfs_root *root = BTRFS_I(inode)->root;
5447
5448 if (btrfs_root_readonly(root))
5449 return -EROFS;
5450
5451 if (flags & S_VERSION)
5452 inode_inc_iversion(inode);
5453 if (flags & S_CTIME)
5454 inode->i_ctime = *now;
5455 if (flags & S_MTIME)
5456 inode->i_mtime = *now;
5457 if (flags & S_ATIME)
5458 inode->i_atime = *now;
5459 return btrfs_dirty_inode(inode);
5460 }
5461
5462 /*
5463 * find the highest existing sequence number in a directory
5464 * and then set the in-memory index_cnt variable to reflect
5465 * free sequence numbers
5466 */
5467 static int btrfs_set_inode_index_count(struct inode *inode)
5468 {
5469 struct btrfs_root *root = BTRFS_I(inode)->root;
5470 struct btrfs_key key, found_key;
5471 struct btrfs_path *path;
5472 struct extent_buffer *leaf;
5473 int ret;
5474
5475 key.objectid = btrfs_ino(inode);
5476 btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
5477 key.offset = (u64)-1;
5478
5479 path = btrfs_alloc_path();
5480 if (!path)
5481 return -ENOMEM;
5482
5483 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5484 if (ret < 0)
5485 goto out;
5486 /* FIXME: we should be able to handle this */
5487 if (ret == 0)
5488 goto out;
5489 ret = 0;
5490
5491 /*
5492 * MAGIC NUMBER EXPLANATION:
5493 * since we search a directory based on f_pos we have to start at 2
5494 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
5495 * else has to start at 2
5496 */
5497 if (path->slots[0] == 0) {
5498 BTRFS_I(inode)->index_cnt = 2;
5499 goto out;
5500 }
5501
5502 path->slots[0]--;
5503
5504 leaf = path->nodes[0];
5505 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5506
5507 if (found_key.objectid != btrfs_ino(inode) ||
5508 btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) {
5509 BTRFS_I(inode)->index_cnt = 2;
5510 goto out;
5511 }
5512
5513 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
5514 out:
5515 btrfs_free_path(path);
5516 return ret;
5517 }
5518
5519 /*
5520 * helper to find a free sequence number in a given directory. This current
5521 * code is very simple, later versions will do smarter things in the btree
5522 */
5523 int btrfs_set_inode_index(struct inode *dir, u64 *index)
5524 {
5525 int ret = 0;
5526
5527 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
5528 ret = btrfs_inode_delayed_dir_index_count(dir);
5529 if (ret) {
5530 ret = btrfs_set_inode_index_count(dir);
5531 if (ret)
5532 return ret;
5533 }
5534 }
5535
5536 *index = BTRFS_I(dir)->index_cnt;
5537 BTRFS_I(dir)->index_cnt++;
5538
5539 return ret;
5540 }
5541
5542 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
5543 struct btrfs_root *root,
5544 struct inode *dir,
5545 const char *name, int name_len,
5546 u64 ref_objectid, u64 objectid,
5547 umode_t mode, u64 *index)
5548 {
5549 struct inode *inode;
5550 struct btrfs_inode_item *inode_item;
5551 struct btrfs_key *location;
5552 struct btrfs_path *path;
5553 struct btrfs_inode_ref *ref;
5554 struct btrfs_key key[2];
5555 u32 sizes[2];
5556 unsigned long ptr;
5557 int ret;
5558
5559 path = btrfs_alloc_path();
5560 if (!path)
5561 return ERR_PTR(-ENOMEM);
5562
5563 inode = new_inode(root->fs_info->sb);
5564 if (!inode) {
5565 btrfs_free_path(path);
5566 return ERR_PTR(-ENOMEM);
5567 }
5568
5569 /*
5570 * we have to initialize this early, so we can reclaim the inode
5571 * number if we fail afterwards in this function.
5572 */
5573 inode->i_ino = objectid;
5574
5575 if (dir) {
5576 trace_btrfs_inode_request(dir);
5577
5578 ret = btrfs_set_inode_index(dir, index);
5579 if (ret) {
5580 btrfs_free_path(path);
5581 iput(inode);
5582 return ERR_PTR(ret);
5583 }
5584 }
5585 /*
5586 * index_cnt is ignored for everything but a dir,
5587 * btrfs_get_inode_index_count has an explanation for the magic
5588 * number
5589 */
5590 BTRFS_I(inode)->index_cnt = 2;
5591 BTRFS_I(inode)->dir_index = *index;
5592 BTRFS_I(inode)->root = root;
5593 BTRFS_I(inode)->generation = trans->transid;
5594 inode->i_generation = BTRFS_I(inode)->generation;
5595
5596 /*
5597 * We could have gotten an inode number from somebody who was fsynced
5598 * and then removed in this same transaction, so let's just set full
5599 * sync since it will be a full sync anyway and this will blow away the
5600 * old info in the log.
5601 */
5602 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
5603
5604 key[0].objectid = objectid;
5605 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
5606 key[0].offset = 0;
5607
5608 /*
5609 * Start new inodes with an inode_ref. This is slightly more
5610 * efficient for small numbers of hard links since they will
5611 * be packed into one item. Extended refs will kick in if we
5612 * add more hard links than can fit in the ref item.
5613 */
5614 key[1].objectid = objectid;
5615 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
5616 key[1].offset = ref_objectid;
5617
5618 sizes[0] = sizeof(struct btrfs_inode_item);
5619 sizes[1] = name_len + sizeof(*ref);
5620
5621 path->leave_spinning = 1;
5622 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
5623 if (ret != 0)
5624 goto fail;
5625
5626 inode_init_owner(inode, dir, mode);
5627 inode_set_bytes(inode, 0);
5628 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
5629 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
5630 struct btrfs_inode_item);
5631 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
5632 sizeof(*inode_item));
5633 fill_inode_item(trans, path->nodes[0], inode_item, inode);
5634
5635 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
5636 struct btrfs_inode_ref);
5637 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
5638 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
5639 ptr = (unsigned long)(ref + 1);
5640 write_extent_buffer(path->nodes[0], name, ptr, name_len);
5641
5642 btrfs_mark_buffer_dirty(path->nodes[0]);
5643 btrfs_free_path(path);
5644
5645 location = &BTRFS_I(inode)->location;
5646 location->objectid = objectid;
5647 location->offset = 0;
5648 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
5649
5650 btrfs_inherit_iflags(inode, dir);
5651
5652 if (S_ISREG(mode)) {
5653 if (btrfs_test_opt(root, NODATASUM))
5654 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
5655 if (btrfs_test_opt(root, NODATACOW))
5656 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
5657 BTRFS_INODE_NODATASUM;
5658 }
5659
5660 btrfs_insert_inode_hash(inode);
5661 inode_tree_add(inode);
5662
5663 trace_btrfs_inode_new(inode);
5664 btrfs_set_inode_last_trans(trans, inode);
5665
5666 btrfs_update_root_times(trans, root);
5667
5668 ret = btrfs_inode_inherit_props(trans, inode, dir);
5669 if (ret)
5670 btrfs_err(root->fs_info,
5671 "error inheriting props for ino %llu (root %llu): %d",
5672 btrfs_ino(inode), root->root_key.objectid, ret);
5673
5674 return inode;
5675 fail:
5676 if (dir)
5677 BTRFS_I(dir)->index_cnt--;
5678 btrfs_free_path(path);
5679 iput(inode);
5680 return ERR_PTR(ret);
5681 }
5682
5683 static inline u8 btrfs_inode_type(struct inode *inode)
5684 {
5685 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
5686 }
5687
5688 /*
5689 * utility function to add 'inode' into 'parent_inode' with
5690 * a give name and a given sequence number.
5691 * if 'add_backref' is true, also insert a backref from the
5692 * inode to the parent directory.
5693 */
5694 int btrfs_add_link(struct btrfs_trans_handle *trans,
5695 struct inode *parent_inode, struct inode *inode,
5696 const char *name, int name_len, int add_backref, u64 index)
5697 {
5698 int ret = 0;
5699 struct btrfs_key key;
5700 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
5701 u64 ino = btrfs_ino(inode);
5702 u64 parent_ino = btrfs_ino(parent_inode);
5703
5704 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5705 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
5706 } else {
5707 key.objectid = ino;
5708 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
5709 key.offset = 0;
5710 }
5711
5712 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5713 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
5714 key.objectid, root->root_key.objectid,
5715 parent_ino, index, name, name_len);
5716 } else if (add_backref) {
5717 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
5718 parent_ino, index);
5719 }
5720
5721 /* Nothing to clean up yet */
5722 if (ret)
5723 return ret;
5724
5725 ret = btrfs_insert_dir_item(trans, root, name, name_len,
5726 parent_inode, &key,
5727 btrfs_inode_type(inode), index);
5728 if (ret == -EEXIST || ret == -EOVERFLOW)
5729 goto fail_dir_item;
5730 else if (ret) {
5731 btrfs_abort_transaction(trans, root, ret);
5732 return ret;
5733 }
5734
5735 btrfs_i_size_write(parent_inode, parent_inode->i_size +
5736 name_len * 2);
5737 inode_inc_iversion(parent_inode);
5738 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
5739 ret = btrfs_update_inode(trans, root, parent_inode);
5740 if (ret)
5741 btrfs_abort_transaction(trans, root, ret);
5742 return ret;
5743
5744 fail_dir_item:
5745 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5746 u64 local_index;
5747 int err;
5748 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
5749 key.objectid, root->root_key.objectid,
5750 parent_ino, &local_index, name, name_len);
5751
5752 } else if (add_backref) {
5753 u64 local_index;
5754 int err;
5755
5756 err = btrfs_del_inode_ref(trans, root, name, name_len,
5757 ino, parent_ino, &local_index);
5758 }
5759 return ret;
5760 }
5761
5762 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
5763 struct inode *dir, struct dentry *dentry,
5764 struct inode *inode, int backref, u64 index)
5765 {
5766 int err = btrfs_add_link(trans, dir, inode,
5767 dentry->d_name.name, dentry->d_name.len,
5768 backref, index);
5769 if (err > 0)
5770 err = -EEXIST;
5771 return err;
5772 }
5773
5774 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
5775 umode_t mode, dev_t rdev)
5776 {
5777 struct btrfs_trans_handle *trans;
5778 struct btrfs_root *root = BTRFS_I(dir)->root;
5779 struct inode *inode = NULL;
5780 int err;
5781 int drop_inode = 0;
5782 u64 objectid;
5783 u64 index = 0;
5784
5785 if (!new_valid_dev(rdev))
5786 return -EINVAL;
5787
5788 /*
5789 * 2 for inode item and ref
5790 * 2 for dir items
5791 * 1 for xattr if selinux is on
5792 */
5793 trans = btrfs_start_transaction(root, 5);
5794 if (IS_ERR(trans))
5795 return PTR_ERR(trans);
5796
5797 err = btrfs_find_free_ino(root, &objectid);
5798 if (err)
5799 goto out_unlock;
5800
5801 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5802 dentry->d_name.len, btrfs_ino(dir), objectid,
5803 mode, &index);
5804 if (IS_ERR(inode)) {
5805 err = PTR_ERR(inode);
5806 goto out_unlock;
5807 }
5808
5809 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5810 if (err) {
5811 drop_inode = 1;
5812 goto out_unlock;
5813 }
5814
5815 /*
5816 * If the active LSM wants to access the inode during
5817 * d_instantiate it needs these. Smack checks to see
5818 * if the filesystem supports xattrs by looking at the
5819 * ops vector.
5820 */
5821
5822 inode->i_op = &btrfs_special_inode_operations;
5823 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5824 if (err)
5825 drop_inode = 1;
5826 else {
5827 init_special_inode(inode, inode->i_mode, rdev);
5828 btrfs_update_inode(trans, root, inode);
5829 d_instantiate(dentry, inode);
5830 }
5831 out_unlock:
5832 btrfs_end_transaction(trans, root);
5833 btrfs_balance_delayed_items(root);
5834 btrfs_btree_balance_dirty(root);
5835 if (drop_inode) {
5836 inode_dec_link_count(inode);
5837 iput(inode);
5838 }
5839 return err;
5840 }
5841
5842 static int btrfs_create(struct inode *dir, struct dentry *dentry,
5843 umode_t mode, bool excl)
5844 {
5845 struct btrfs_trans_handle *trans;
5846 struct btrfs_root *root = BTRFS_I(dir)->root;
5847 struct inode *inode = NULL;
5848 int drop_inode_on_err = 0;
5849 int err;
5850 u64 objectid;
5851 u64 index = 0;
5852
5853 /*
5854 * 2 for inode item and ref
5855 * 2 for dir items
5856 * 1 for xattr if selinux is on
5857 */
5858 trans = btrfs_start_transaction(root, 5);
5859 if (IS_ERR(trans))
5860 return PTR_ERR(trans);
5861
5862 err = btrfs_find_free_ino(root, &objectid);
5863 if (err)
5864 goto out_unlock;
5865
5866 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5867 dentry->d_name.len, btrfs_ino(dir), objectid,
5868 mode, &index);
5869 if (IS_ERR(inode)) {
5870 err = PTR_ERR(inode);
5871 goto out_unlock;
5872 }
5873 drop_inode_on_err = 1;
5874
5875 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5876 if (err)
5877 goto out_unlock;
5878
5879 err = btrfs_update_inode(trans, root, inode);
5880 if (err)
5881 goto out_unlock;
5882
5883 /*
5884 * If the active LSM wants to access the inode during
5885 * d_instantiate it needs these. Smack checks to see
5886 * if the filesystem supports xattrs by looking at the
5887 * ops vector.
5888 */
5889 inode->i_fop = &btrfs_file_operations;
5890 inode->i_op = &btrfs_file_inode_operations;
5891
5892 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5893 if (err)
5894 goto out_unlock;
5895
5896 inode->i_mapping->a_ops = &btrfs_aops;
5897 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
5898 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
5899 d_instantiate(dentry, inode);
5900
5901 out_unlock:
5902 btrfs_end_transaction(trans, root);
5903 if (err && drop_inode_on_err) {
5904 inode_dec_link_count(inode);
5905 iput(inode);
5906 }
5907 btrfs_balance_delayed_items(root);
5908 btrfs_btree_balance_dirty(root);
5909 return err;
5910 }
5911
5912 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
5913 struct dentry *dentry)
5914 {
5915 struct btrfs_trans_handle *trans;
5916 struct btrfs_root *root = BTRFS_I(dir)->root;
5917 struct inode *inode = old_dentry->d_inode;
5918 u64 index;
5919 int err;
5920 int drop_inode = 0;
5921
5922 /* do not allow sys_link's with other subvols of the same device */
5923 if (root->objectid != BTRFS_I(inode)->root->objectid)
5924 return -EXDEV;
5925
5926 if (inode->i_nlink >= BTRFS_LINK_MAX)
5927 return -EMLINK;
5928
5929 err = btrfs_set_inode_index(dir, &index);
5930 if (err)
5931 goto fail;
5932
5933 /*
5934 * 2 items for inode and inode ref
5935 * 2 items for dir items
5936 * 1 item for parent inode
5937 */
5938 trans = btrfs_start_transaction(root, 5);
5939 if (IS_ERR(trans)) {
5940 err = PTR_ERR(trans);
5941 goto fail;
5942 }
5943
5944 /* There are several dir indexes for this inode, clear the cache. */
5945 BTRFS_I(inode)->dir_index = 0ULL;
5946 inc_nlink(inode);
5947 inode_inc_iversion(inode);
5948 inode->i_ctime = CURRENT_TIME;
5949 ihold(inode);
5950 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
5951
5952 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
5953
5954 if (err) {
5955 drop_inode = 1;
5956 } else {
5957 struct dentry *parent = dentry->d_parent;
5958 err = btrfs_update_inode(trans, root, inode);
5959 if (err)
5960 goto fail;
5961 d_instantiate(dentry, inode);
5962 btrfs_log_new_name(trans, inode, NULL, parent);
5963 }
5964
5965 btrfs_end_transaction(trans, root);
5966 btrfs_balance_delayed_items(root);
5967 fail:
5968 if (drop_inode) {
5969 inode_dec_link_count(inode);
5970 iput(inode);
5971 }
5972 btrfs_btree_balance_dirty(root);
5973 return err;
5974 }
5975
5976 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
5977 {
5978 struct inode *inode = NULL;
5979 struct btrfs_trans_handle *trans;
5980 struct btrfs_root *root = BTRFS_I(dir)->root;
5981 int err = 0;
5982 int drop_on_err = 0;
5983 u64 objectid = 0;
5984 u64 index = 0;
5985
5986 /*
5987 * 2 items for inode and ref
5988 * 2 items for dir items
5989 * 1 for xattr if selinux is on
5990 */
5991 trans = btrfs_start_transaction(root, 5);
5992 if (IS_ERR(trans))
5993 return PTR_ERR(trans);
5994
5995 err = btrfs_find_free_ino(root, &objectid);
5996 if (err)
5997 goto out_fail;
5998
5999 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6000 dentry->d_name.len, btrfs_ino(dir), objectid,
6001 S_IFDIR | mode, &index);
6002 if (IS_ERR(inode)) {
6003 err = PTR_ERR(inode);
6004 goto out_fail;
6005 }
6006
6007 drop_on_err = 1;
6008
6009 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6010 if (err)
6011 goto out_fail;
6012
6013 inode->i_op = &btrfs_dir_inode_operations;
6014 inode->i_fop = &btrfs_dir_file_operations;
6015
6016 btrfs_i_size_write(inode, 0);
6017 err = btrfs_update_inode(trans, root, inode);
6018 if (err)
6019 goto out_fail;
6020
6021 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
6022 dentry->d_name.len, 0, index);
6023 if (err)
6024 goto out_fail;
6025
6026 d_instantiate(dentry, inode);
6027 drop_on_err = 0;
6028
6029 out_fail:
6030 btrfs_end_transaction(trans, root);
6031 if (drop_on_err)
6032 iput(inode);
6033 btrfs_balance_delayed_items(root);
6034 btrfs_btree_balance_dirty(root);
6035 return err;
6036 }
6037
6038 /* helper for btfs_get_extent. Given an existing extent in the tree,
6039 * and an extent that you want to insert, deal with overlap and insert
6040 * the new extent into the tree.
6041 */
6042 static int merge_extent_mapping(struct extent_map_tree *em_tree,
6043 struct extent_map *existing,
6044 struct extent_map *em,
6045 u64 map_start, u64 map_len)
6046 {
6047 u64 start_diff;
6048
6049 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
6050 start_diff = map_start - em->start;
6051 em->start = map_start;
6052 em->len = map_len;
6053 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
6054 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
6055 em->block_start += start_diff;
6056 em->block_len -= start_diff;
6057 }
6058 return add_extent_mapping(em_tree, em, 0);
6059 }
6060
6061 static noinline int uncompress_inline(struct btrfs_path *path,
6062 struct inode *inode, struct page *page,
6063 size_t pg_offset, u64 extent_offset,
6064 struct btrfs_file_extent_item *item)
6065 {
6066 int ret;
6067 struct extent_buffer *leaf = path->nodes[0];
6068 char *tmp;
6069 size_t max_size;
6070 unsigned long inline_size;
6071 unsigned long ptr;
6072 int compress_type;
6073
6074 WARN_ON(pg_offset != 0);
6075 compress_type = btrfs_file_extent_compression(leaf, item);
6076 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6077 inline_size = btrfs_file_extent_inline_item_len(leaf,
6078 btrfs_item_nr(path->slots[0]));
6079 tmp = kmalloc(inline_size, GFP_NOFS);
6080 if (!tmp)
6081 return -ENOMEM;
6082 ptr = btrfs_file_extent_inline_start(item);
6083
6084 read_extent_buffer(leaf, tmp, ptr, inline_size);
6085
6086 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
6087 ret = btrfs_decompress(compress_type, tmp, page,
6088 extent_offset, inline_size, max_size);
6089 kfree(tmp);
6090 return ret;
6091 }
6092
6093 /*
6094 * a bit scary, this does extent mapping from logical file offset to the disk.
6095 * the ugly parts come from merging extents from the disk with the in-ram
6096 * representation. This gets more complex because of the data=ordered code,
6097 * where the in-ram extents might be locked pending data=ordered completion.
6098 *
6099 * This also copies inline extents directly into the page.
6100 */
6101
6102 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
6103 size_t pg_offset, u64 start, u64 len,
6104 int create)
6105 {
6106 int ret;
6107 int err = 0;
6108 u64 bytenr;
6109 u64 extent_start = 0;
6110 u64 extent_end = 0;
6111 u64 objectid = btrfs_ino(inode);
6112 u32 found_type;
6113 struct btrfs_path *path = NULL;
6114 struct btrfs_root *root = BTRFS_I(inode)->root;
6115 struct btrfs_file_extent_item *item;
6116 struct extent_buffer *leaf;
6117 struct btrfs_key found_key;
6118 struct extent_map *em = NULL;
6119 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
6120 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6121 struct btrfs_trans_handle *trans = NULL;
6122 int compress_type;
6123
6124 again:
6125 read_lock(&em_tree->lock);
6126 em = lookup_extent_mapping(em_tree, start, len);
6127 if (em)
6128 em->bdev = root->fs_info->fs_devices->latest_bdev;
6129 read_unlock(&em_tree->lock);
6130
6131 if (em) {
6132 if (em->start > start || em->start + em->len <= start)
6133 free_extent_map(em);
6134 else if (em->block_start == EXTENT_MAP_INLINE && page)
6135 free_extent_map(em);
6136 else
6137 goto out;
6138 }
6139 em = alloc_extent_map();
6140 if (!em) {
6141 err = -ENOMEM;
6142 goto out;
6143 }
6144 em->bdev = root->fs_info->fs_devices->latest_bdev;
6145 em->start = EXTENT_MAP_HOLE;
6146 em->orig_start = EXTENT_MAP_HOLE;
6147 em->len = (u64)-1;
6148 em->block_len = (u64)-1;
6149
6150 if (!path) {
6151 path = btrfs_alloc_path();
6152 if (!path) {
6153 err = -ENOMEM;
6154 goto out;
6155 }
6156 /*
6157 * Chances are we'll be called again, so go ahead and do
6158 * readahead
6159 */
6160 path->reada = 1;
6161 }
6162
6163 ret = btrfs_lookup_file_extent(trans, root, path,
6164 objectid, start, trans != NULL);
6165 if (ret < 0) {
6166 err = ret;
6167 goto out;
6168 }
6169
6170 if (ret != 0) {
6171 if (path->slots[0] == 0)
6172 goto not_found;
6173 path->slots[0]--;
6174 }
6175
6176 leaf = path->nodes[0];
6177 item = btrfs_item_ptr(leaf, path->slots[0],
6178 struct btrfs_file_extent_item);
6179 /* are we inside the extent that was found? */
6180 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6181 found_type = btrfs_key_type(&found_key);
6182 if (found_key.objectid != objectid ||
6183 found_type != BTRFS_EXTENT_DATA_KEY) {
6184 /*
6185 * If we backup past the first extent we want to move forward
6186 * and see if there is an extent in front of us, otherwise we'll
6187 * say there is a hole for our whole search range which can
6188 * cause problems.
6189 */
6190 extent_end = start;
6191 goto next;
6192 }
6193
6194 found_type = btrfs_file_extent_type(leaf, item);
6195 extent_start = found_key.offset;
6196 compress_type = btrfs_file_extent_compression(leaf, item);
6197 if (found_type == BTRFS_FILE_EXTENT_REG ||
6198 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6199 extent_end = extent_start +
6200 btrfs_file_extent_num_bytes(leaf, item);
6201 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6202 size_t size;
6203 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6204 extent_end = ALIGN(extent_start + size, root->sectorsize);
6205 }
6206 next:
6207 if (start >= extent_end) {
6208 path->slots[0]++;
6209 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6210 ret = btrfs_next_leaf(root, path);
6211 if (ret < 0) {
6212 err = ret;
6213 goto out;
6214 }
6215 if (ret > 0)
6216 goto not_found;
6217 leaf = path->nodes[0];
6218 }
6219 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6220 if (found_key.objectid != objectid ||
6221 found_key.type != BTRFS_EXTENT_DATA_KEY)
6222 goto not_found;
6223 if (start + len <= found_key.offset)
6224 goto not_found;
6225 em->start = start;
6226 em->orig_start = start;
6227 em->len = found_key.offset - start;
6228 goto not_found_em;
6229 }
6230
6231 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, item);
6232 if (found_type == BTRFS_FILE_EXTENT_REG ||
6233 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6234 em->start = extent_start;
6235 em->len = extent_end - extent_start;
6236 em->orig_start = extent_start -
6237 btrfs_file_extent_offset(leaf, item);
6238 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf,
6239 item);
6240 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
6241 if (bytenr == 0) {
6242 em->block_start = EXTENT_MAP_HOLE;
6243 goto insert;
6244 }
6245 if (compress_type != BTRFS_COMPRESS_NONE) {
6246 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
6247 em->compress_type = compress_type;
6248 em->block_start = bytenr;
6249 em->block_len = em->orig_block_len;
6250 } else {
6251 bytenr += btrfs_file_extent_offset(leaf, item);
6252 em->block_start = bytenr;
6253 em->block_len = em->len;
6254 if (found_type == BTRFS_FILE_EXTENT_PREALLOC)
6255 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
6256 }
6257 goto insert;
6258 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6259 unsigned long ptr;
6260 char *map;
6261 size_t size;
6262 size_t extent_offset;
6263 size_t copy_size;
6264
6265 em->block_start = EXTENT_MAP_INLINE;
6266 if (!page || create) {
6267 em->start = extent_start;
6268 em->len = extent_end - extent_start;
6269 goto out;
6270 }
6271
6272 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6273 extent_offset = page_offset(page) + pg_offset - extent_start;
6274 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
6275 size - extent_offset);
6276 em->start = extent_start + extent_offset;
6277 em->len = ALIGN(copy_size, root->sectorsize);
6278 em->orig_block_len = em->len;
6279 em->orig_start = em->start;
6280 if (compress_type) {
6281 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
6282 em->compress_type = compress_type;
6283 }
6284 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6285 if (create == 0 && !PageUptodate(page)) {
6286 if (btrfs_file_extent_compression(leaf, item) !=
6287 BTRFS_COMPRESS_NONE) {
6288 ret = uncompress_inline(path, inode, page,
6289 pg_offset,
6290 extent_offset, item);
6291 if (ret) {
6292 err = ret;
6293 goto out;
6294 }
6295 } else {
6296 map = kmap(page);
6297 read_extent_buffer(leaf, map + pg_offset, ptr,
6298 copy_size);
6299 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
6300 memset(map + pg_offset + copy_size, 0,
6301 PAGE_CACHE_SIZE - pg_offset -
6302 copy_size);
6303 }
6304 kunmap(page);
6305 }
6306 flush_dcache_page(page);
6307 } else if (create && PageUptodate(page)) {
6308 BUG();
6309 if (!trans) {
6310 kunmap(page);
6311 free_extent_map(em);
6312 em = NULL;
6313
6314 btrfs_release_path(path);
6315 trans = btrfs_join_transaction(root);
6316
6317 if (IS_ERR(trans))
6318 return ERR_CAST(trans);
6319 goto again;
6320 }
6321 map = kmap(page);
6322 write_extent_buffer(leaf, map + pg_offset, ptr,
6323 copy_size);
6324 kunmap(page);
6325 btrfs_mark_buffer_dirty(leaf);
6326 }
6327 set_extent_uptodate(io_tree, em->start,
6328 extent_map_end(em) - 1, NULL, GFP_NOFS);
6329 goto insert;
6330 } else {
6331 WARN(1, KERN_ERR "btrfs unknown found_type %d\n", found_type);
6332 }
6333 not_found:
6334 em->start = start;
6335 em->orig_start = start;
6336 em->len = len;
6337 not_found_em:
6338 em->block_start = EXTENT_MAP_HOLE;
6339 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
6340 insert:
6341 btrfs_release_path(path);
6342 if (em->start > start || extent_map_end(em) <= start) {
6343 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
6344 em->start, em->len, start, len);
6345 err = -EIO;
6346 goto out;
6347 }
6348
6349 err = 0;
6350 write_lock(&em_tree->lock);
6351 ret = add_extent_mapping(em_tree, em, 0);
6352 /* it is possible that someone inserted the extent into the tree
6353 * while we had the lock dropped. It is also possible that
6354 * an overlapping map exists in the tree
6355 */
6356 if (ret == -EEXIST) {
6357 struct extent_map *existing;
6358
6359 ret = 0;
6360
6361 existing = lookup_extent_mapping(em_tree, start, len);
6362 if (existing && (existing->start > start ||
6363 existing->start + existing->len <= start)) {
6364 free_extent_map(existing);
6365 existing = NULL;
6366 }
6367 if (!existing) {
6368 existing = lookup_extent_mapping(em_tree, em->start,
6369 em->len);
6370 if (existing) {
6371 err = merge_extent_mapping(em_tree, existing,
6372 em, start,
6373 root->sectorsize);
6374 free_extent_map(existing);
6375 if (err) {
6376 free_extent_map(em);
6377 em = NULL;
6378 }
6379 } else {
6380 err = -EIO;
6381 free_extent_map(em);
6382 em = NULL;
6383 }
6384 } else {
6385 free_extent_map(em);
6386 em = existing;
6387 err = 0;
6388 }
6389 }
6390 write_unlock(&em_tree->lock);
6391 out:
6392
6393 trace_btrfs_get_extent(root, em);
6394
6395 if (path)
6396 btrfs_free_path(path);
6397 if (trans) {
6398 ret = btrfs_end_transaction(trans, root);
6399 if (!err)
6400 err = ret;
6401 }
6402 if (err) {
6403 free_extent_map(em);
6404 return ERR_PTR(err);
6405 }
6406 BUG_ON(!em); /* Error is always set */
6407 return em;
6408 }
6409
6410 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
6411 size_t pg_offset, u64 start, u64 len,
6412 int create)
6413 {
6414 struct extent_map *em;
6415 struct extent_map *hole_em = NULL;
6416 u64 range_start = start;
6417 u64 end;
6418 u64 found;
6419 u64 found_end;
6420 int err = 0;
6421
6422 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
6423 if (IS_ERR(em))
6424 return em;
6425 if (em) {
6426 /*
6427 * if our em maps to
6428 * - a hole or
6429 * - a pre-alloc extent,
6430 * there might actually be delalloc bytes behind it.
6431 */
6432 if (em->block_start != EXTENT_MAP_HOLE &&
6433 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6434 return em;
6435 else
6436 hole_em = em;
6437 }
6438
6439 /* check to see if we've wrapped (len == -1 or similar) */
6440 end = start + len;
6441 if (end < start)
6442 end = (u64)-1;
6443 else
6444 end -= 1;
6445
6446 em = NULL;
6447
6448 /* ok, we didn't find anything, lets look for delalloc */
6449 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
6450 end, len, EXTENT_DELALLOC, 1);
6451 found_end = range_start + found;
6452 if (found_end < range_start)
6453 found_end = (u64)-1;
6454
6455 /*
6456 * we didn't find anything useful, return
6457 * the original results from get_extent()
6458 */
6459 if (range_start > end || found_end <= start) {
6460 em = hole_em;
6461 hole_em = NULL;
6462 goto out;
6463 }
6464
6465 /* adjust the range_start to make sure it doesn't
6466 * go backwards from the start they passed in
6467 */
6468 range_start = max(start, range_start);
6469 found = found_end - range_start;
6470
6471 if (found > 0) {
6472 u64 hole_start = start;
6473 u64 hole_len = len;
6474
6475 em = alloc_extent_map();
6476 if (!em) {
6477 err = -ENOMEM;
6478 goto out;
6479 }
6480 /*
6481 * when btrfs_get_extent can't find anything it
6482 * returns one huge hole
6483 *
6484 * make sure what it found really fits our range, and
6485 * adjust to make sure it is based on the start from
6486 * the caller
6487 */
6488 if (hole_em) {
6489 u64 calc_end = extent_map_end(hole_em);
6490
6491 if (calc_end <= start || (hole_em->start > end)) {
6492 free_extent_map(hole_em);
6493 hole_em = NULL;
6494 } else {
6495 hole_start = max(hole_em->start, start);
6496 hole_len = calc_end - hole_start;
6497 }
6498 }
6499 em->bdev = NULL;
6500 if (hole_em && range_start > hole_start) {
6501 /* our hole starts before our delalloc, so we
6502 * have to return just the parts of the hole
6503 * that go until the delalloc starts
6504 */
6505 em->len = min(hole_len,
6506 range_start - hole_start);
6507 em->start = hole_start;
6508 em->orig_start = hole_start;
6509 /*
6510 * don't adjust block start at all,
6511 * it is fixed at EXTENT_MAP_HOLE
6512 */
6513 em->block_start = hole_em->block_start;
6514 em->block_len = hole_len;
6515 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
6516 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
6517 } else {
6518 em->start = range_start;
6519 em->len = found;
6520 em->orig_start = range_start;
6521 em->block_start = EXTENT_MAP_DELALLOC;
6522 em->block_len = found;
6523 }
6524 } else if (hole_em) {
6525 return hole_em;
6526 }
6527 out:
6528
6529 free_extent_map(hole_em);
6530 if (err) {
6531 free_extent_map(em);
6532 return ERR_PTR(err);
6533 }
6534 return em;
6535 }
6536
6537 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
6538 u64 start, u64 len)
6539 {
6540 struct btrfs_root *root = BTRFS_I(inode)->root;
6541 struct extent_map *em;
6542 struct btrfs_key ins;
6543 u64 alloc_hint;
6544 int ret;
6545
6546 alloc_hint = get_extent_allocation_hint(inode, start, len);
6547 ret = btrfs_reserve_extent(root, len, root->sectorsize, 0,
6548 alloc_hint, &ins, 1);
6549 if (ret)
6550 return ERR_PTR(ret);
6551
6552 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
6553 ins.offset, ins.offset, ins.offset, 0);
6554 if (IS_ERR(em)) {
6555 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
6556 return em;
6557 }
6558
6559 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
6560 ins.offset, ins.offset, 0);
6561 if (ret) {
6562 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
6563 free_extent_map(em);
6564 return ERR_PTR(ret);
6565 }
6566
6567 return em;
6568 }
6569
6570 /*
6571 * returns 1 when the nocow is safe, < 1 on error, 0 if the
6572 * block must be cow'd
6573 */
6574 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
6575 u64 *orig_start, u64 *orig_block_len,
6576 u64 *ram_bytes)
6577 {
6578 struct btrfs_trans_handle *trans;
6579 struct btrfs_path *path;
6580 int ret;
6581 struct extent_buffer *leaf;
6582 struct btrfs_root *root = BTRFS_I(inode)->root;
6583 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6584 struct btrfs_file_extent_item *fi;
6585 struct btrfs_key key;
6586 u64 disk_bytenr;
6587 u64 backref_offset;
6588 u64 extent_end;
6589 u64 num_bytes;
6590 int slot;
6591 int found_type;
6592 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
6593
6594 path = btrfs_alloc_path();
6595 if (!path)
6596 return -ENOMEM;
6597
6598 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
6599 offset, 0);
6600 if (ret < 0)
6601 goto out;
6602
6603 slot = path->slots[0];
6604 if (ret == 1) {
6605 if (slot == 0) {
6606 /* can't find the item, must cow */
6607 ret = 0;
6608 goto out;
6609 }
6610 slot--;
6611 }
6612 ret = 0;
6613 leaf = path->nodes[0];
6614 btrfs_item_key_to_cpu(leaf, &key, slot);
6615 if (key.objectid != btrfs_ino(inode) ||
6616 key.type != BTRFS_EXTENT_DATA_KEY) {
6617 /* not our file or wrong item type, must cow */
6618 goto out;
6619 }
6620
6621 if (key.offset > offset) {
6622 /* Wrong offset, must cow */
6623 goto out;
6624 }
6625
6626 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
6627 found_type = btrfs_file_extent_type(leaf, fi);
6628 if (found_type != BTRFS_FILE_EXTENT_REG &&
6629 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
6630 /* not a regular extent, must cow */
6631 goto out;
6632 }
6633
6634 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
6635 goto out;
6636
6637 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
6638 if (extent_end <= offset)
6639 goto out;
6640
6641 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
6642 if (disk_bytenr == 0)
6643 goto out;
6644
6645 if (btrfs_file_extent_compression(leaf, fi) ||
6646 btrfs_file_extent_encryption(leaf, fi) ||
6647 btrfs_file_extent_other_encoding(leaf, fi))
6648 goto out;
6649
6650 backref_offset = btrfs_file_extent_offset(leaf, fi);
6651
6652 if (orig_start) {
6653 *orig_start = key.offset - backref_offset;
6654 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
6655 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
6656 }
6657
6658 if (btrfs_extent_readonly(root, disk_bytenr))
6659 goto out;
6660
6661 num_bytes = min(offset + *len, extent_end) - offset;
6662 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6663 u64 range_end;
6664
6665 range_end = round_up(offset + num_bytes, root->sectorsize) - 1;
6666 ret = test_range_bit(io_tree, offset, range_end,
6667 EXTENT_DELALLOC, 0, NULL);
6668 if (ret) {
6669 ret = -EAGAIN;
6670 goto out;
6671 }
6672 }
6673
6674 btrfs_release_path(path);
6675
6676 /*
6677 * look for other files referencing this extent, if we
6678 * find any we must cow
6679 */
6680 trans = btrfs_join_transaction(root);
6681 if (IS_ERR(trans)) {
6682 ret = 0;
6683 goto out;
6684 }
6685
6686 ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
6687 key.offset - backref_offset, disk_bytenr);
6688 btrfs_end_transaction(trans, root);
6689 if (ret) {
6690 ret = 0;
6691 goto out;
6692 }
6693
6694 /*
6695 * adjust disk_bytenr and num_bytes to cover just the bytes
6696 * in this extent we are about to write. If there
6697 * are any csums in that range we have to cow in order
6698 * to keep the csums correct
6699 */
6700 disk_bytenr += backref_offset;
6701 disk_bytenr += offset - key.offset;
6702 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
6703 goto out;
6704 /*
6705 * all of the above have passed, it is safe to overwrite this extent
6706 * without cow
6707 */
6708 *len = num_bytes;
6709 ret = 1;
6710 out:
6711 btrfs_free_path(path);
6712 return ret;
6713 }
6714
6715 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
6716 struct extent_state **cached_state, int writing)
6717 {
6718 struct btrfs_ordered_extent *ordered;
6719 int ret = 0;
6720
6721 while (1) {
6722 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6723 0, cached_state);
6724 /*
6725 * We're concerned with the entire range that we're going to be
6726 * doing DIO to, so we need to make sure theres no ordered
6727 * extents in this range.
6728 */
6729 ordered = btrfs_lookup_ordered_range(inode, lockstart,
6730 lockend - lockstart + 1);
6731
6732 /*
6733 * We need to make sure there are no buffered pages in this
6734 * range either, we could have raced between the invalidate in
6735 * generic_file_direct_write and locking the extent. The
6736 * invalidate needs to happen so that reads after a write do not
6737 * get stale data.
6738 */
6739 if (!ordered && (!writing ||
6740 !test_range_bit(&BTRFS_I(inode)->io_tree,
6741 lockstart, lockend, EXTENT_UPTODATE, 0,
6742 *cached_state)))
6743 break;
6744
6745 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6746 cached_state, GFP_NOFS);
6747
6748 if (ordered) {
6749 btrfs_start_ordered_extent(inode, ordered, 1);
6750 btrfs_put_ordered_extent(ordered);
6751 } else {
6752 /* Screw you mmap */
6753 ret = filemap_write_and_wait_range(inode->i_mapping,
6754 lockstart,
6755 lockend);
6756 if (ret)
6757 break;
6758
6759 /*
6760 * If we found a page that couldn't be invalidated just
6761 * fall back to buffered.
6762 */
6763 ret = invalidate_inode_pages2_range(inode->i_mapping,
6764 lockstart >> PAGE_CACHE_SHIFT,
6765 lockend >> PAGE_CACHE_SHIFT);
6766 if (ret)
6767 break;
6768 }
6769
6770 cond_resched();
6771 }
6772
6773 return ret;
6774 }
6775
6776 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
6777 u64 len, u64 orig_start,
6778 u64 block_start, u64 block_len,
6779 u64 orig_block_len, u64 ram_bytes,
6780 int type)
6781 {
6782 struct extent_map_tree *em_tree;
6783 struct extent_map *em;
6784 struct btrfs_root *root = BTRFS_I(inode)->root;
6785 int ret;
6786
6787 em_tree = &BTRFS_I(inode)->extent_tree;
6788 em = alloc_extent_map();
6789 if (!em)
6790 return ERR_PTR(-ENOMEM);
6791
6792 em->start = start;
6793 em->orig_start = orig_start;
6794 em->mod_start = start;
6795 em->mod_len = len;
6796 em->len = len;
6797 em->block_len = block_len;
6798 em->block_start = block_start;
6799 em->bdev = root->fs_info->fs_devices->latest_bdev;
6800 em->orig_block_len = orig_block_len;
6801 em->ram_bytes = ram_bytes;
6802 em->generation = -1;
6803 set_bit(EXTENT_FLAG_PINNED, &em->flags);
6804 if (type == BTRFS_ORDERED_PREALLOC)
6805 set_bit(EXTENT_FLAG_FILLING, &em->flags);
6806
6807 do {
6808 btrfs_drop_extent_cache(inode, em->start,
6809 em->start + em->len - 1, 0);
6810 write_lock(&em_tree->lock);
6811 ret = add_extent_mapping(em_tree, em, 1);
6812 write_unlock(&em_tree->lock);
6813 } while (ret == -EEXIST);
6814
6815 if (ret) {
6816 free_extent_map(em);
6817 return ERR_PTR(ret);
6818 }
6819
6820 return em;
6821 }
6822
6823
6824 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
6825 struct buffer_head *bh_result, int create)
6826 {
6827 struct extent_map *em;
6828 struct btrfs_root *root = BTRFS_I(inode)->root;
6829 struct extent_state *cached_state = NULL;
6830 u64 start = iblock << inode->i_blkbits;
6831 u64 lockstart, lockend;
6832 u64 len = bh_result->b_size;
6833 int unlock_bits = EXTENT_LOCKED;
6834 int ret = 0;
6835
6836 if (create)
6837 unlock_bits |= EXTENT_DELALLOC | EXTENT_DIRTY;
6838 else
6839 len = min_t(u64, len, root->sectorsize);
6840
6841 lockstart = start;
6842 lockend = start + len - 1;
6843
6844 /*
6845 * If this errors out it's because we couldn't invalidate pagecache for
6846 * this range and we need to fallback to buffered.
6847 */
6848 if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create))
6849 return -ENOTBLK;
6850
6851 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
6852 if (IS_ERR(em)) {
6853 ret = PTR_ERR(em);
6854 goto unlock_err;
6855 }
6856
6857 /*
6858 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
6859 * io. INLINE is special, and we could probably kludge it in here, but
6860 * it's still buffered so for safety lets just fall back to the generic
6861 * buffered path.
6862 *
6863 * For COMPRESSED we _have_ to read the entire extent in so we can
6864 * decompress it, so there will be buffering required no matter what we
6865 * do, so go ahead and fallback to buffered.
6866 *
6867 * We return -ENOTBLK because thats what makes DIO go ahead and go back
6868 * to buffered IO. Don't blame me, this is the price we pay for using
6869 * the generic code.
6870 */
6871 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
6872 em->block_start == EXTENT_MAP_INLINE) {
6873 free_extent_map(em);
6874 ret = -ENOTBLK;
6875 goto unlock_err;
6876 }
6877
6878 /* Just a good old fashioned hole, return */
6879 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
6880 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
6881 free_extent_map(em);
6882 goto unlock_err;
6883 }
6884
6885 /*
6886 * We don't allocate a new extent in the following cases
6887 *
6888 * 1) The inode is marked as NODATACOW. In this case we'll just use the
6889 * existing extent.
6890 * 2) The extent is marked as PREALLOC. We're good to go here and can
6891 * just use the extent.
6892 *
6893 */
6894 if (!create) {
6895 len = min(len, em->len - (start - em->start));
6896 lockstart = start + len;
6897 goto unlock;
6898 }
6899
6900 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
6901 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
6902 em->block_start != EXTENT_MAP_HOLE)) {
6903 int type;
6904 int ret;
6905 u64 block_start, orig_start, orig_block_len, ram_bytes;
6906
6907 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6908 type = BTRFS_ORDERED_PREALLOC;
6909 else
6910 type = BTRFS_ORDERED_NOCOW;
6911 len = min(len, em->len - (start - em->start));
6912 block_start = em->block_start + (start - em->start);
6913
6914 if (can_nocow_extent(inode, start, &len, &orig_start,
6915 &orig_block_len, &ram_bytes) == 1) {
6916 if (type == BTRFS_ORDERED_PREALLOC) {
6917 free_extent_map(em);
6918 em = create_pinned_em(inode, start, len,
6919 orig_start,
6920 block_start, len,
6921 orig_block_len,
6922 ram_bytes, type);
6923 if (IS_ERR(em))
6924 goto unlock_err;
6925 }
6926
6927 ret = btrfs_add_ordered_extent_dio(inode, start,
6928 block_start, len, len, type);
6929 if (ret) {
6930 free_extent_map(em);
6931 goto unlock_err;
6932 }
6933 goto unlock;
6934 }
6935 }
6936
6937 /*
6938 * this will cow the extent, reset the len in case we changed
6939 * it above
6940 */
6941 len = bh_result->b_size;
6942 free_extent_map(em);
6943 em = btrfs_new_extent_direct(inode, start, len);
6944 if (IS_ERR(em)) {
6945 ret = PTR_ERR(em);
6946 goto unlock_err;
6947 }
6948 len = min(len, em->len - (start - em->start));
6949 unlock:
6950 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
6951 inode->i_blkbits;
6952 bh_result->b_size = len;
6953 bh_result->b_bdev = em->bdev;
6954 set_buffer_mapped(bh_result);
6955 if (create) {
6956 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6957 set_buffer_new(bh_result);
6958
6959 /*
6960 * Need to update the i_size under the extent lock so buffered
6961 * readers will get the updated i_size when we unlock.
6962 */
6963 if (start + len > i_size_read(inode))
6964 i_size_write(inode, start + len);
6965
6966 spin_lock(&BTRFS_I(inode)->lock);
6967 BTRFS_I(inode)->outstanding_extents++;
6968 spin_unlock(&BTRFS_I(inode)->lock);
6969
6970 ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6971 lockstart + len - 1, EXTENT_DELALLOC, NULL,
6972 &cached_state, GFP_NOFS);
6973 BUG_ON(ret);
6974 }
6975
6976 /*
6977 * In the case of write we need to clear and unlock the entire range,
6978 * in the case of read we need to unlock only the end area that we
6979 * aren't using if there is any left over space.
6980 */
6981 if (lockstart < lockend) {
6982 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6983 lockend, unlock_bits, 1, 0,
6984 &cached_state, GFP_NOFS);
6985 } else {
6986 free_extent_state(cached_state);
6987 }
6988
6989 free_extent_map(em);
6990
6991 return 0;
6992
6993 unlock_err:
6994 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6995 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
6996 return ret;
6997 }
6998
6999 static void btrfs_endio_direct_read(struct bio *bio, int err)
7000 {
7001 struct btrfs_dio_private *dip = bio->bi_private;
7002 struct bio_vec *bvec;
7003 struct inode *inode = dip->inode;
7004 struct btrfs_root *root = BTRFS_I(inode)->root;
7005 struct bio *dio_bio;
7006 u32 *csums = (u32 *)dip->csum;
7007 u64 start;
7008 int i;
7009
7010 start = dip->logical_offset;
7011 bio_for_each_segment_all(bvec, bio, i) {
7012 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
7013 struct page *page = bvec->bv_page;
7014 char *kaddr;
7015 u32 csum = ~(u32)0;
7016 unsigned long flags;
7017
7018 local_irq_save(flags);
7019 kaddr = kmap_atomic(page);
7020 csum = btrfs_csum_data(kaddr + bvec->bv_offset,
7021 csum, bvec->bv_len);
7022 btrfs_csum_final(csum, (char *)&csum);
7023 kunmap_atomic(kaddr);
7024 local_irq_restore(flags);
7025
7026 flush_dcache_page(bvec->bv_page);
7027 if (csum != csums[i]) {
7028 btrfs_err(root->fs_info, "csum failed ino %llu off %llu csum %u expected csum %u",
7029 btrfs_ino(inode), start, csum,
7030 csums[i]);
7031 err = -EIO;
7032 }
7033 }
7034
7035 start += bvec->bv_len;
7036 }
7037
7038 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
7039 dip->logical_offset + dip->bytes - 1);
7040 dio_bio = dip->dio_bio;
7041
7042 kfree(dip);
7043
7044 /* If we had a csum failure make sure to clear the uptodate flag */
7045 if (err)
7046 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags);
7047 dio_end_io(dio_bio, err);
7048 bio_put(bio);
7049 }
7050
7051 static void btrfs_endio_direct_write(struct bio *bio, int err)
7052 {
7053 struct btrfs_dio_private *dip = bio->bi_private;
7054 struct inode *inode = dip->inode;
7055 struct btrfs_root *root = BTRFS_I(inode)->root;
7056 struct btrfs_ordered_extent *ordered = NULL;
7057 u64 ordered_offset = dip->logical_offset;
7058 u64 ordered_bytes = dip->bytes;
7059 struct bio *dio_bio;
7060 int ret;
7061
7062 if (err)
7063 goto out_done;
7064 again:
7065 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
7066 &ordered_offset,
7067 ordered_bytes, !err);
7068 if (!ret)
7069 goto out_test;
7070
7071 btrfs_init_work(&ordered->work, finish_ordered_fn, NULL, NULL);
7072 btrfs_queue_work(root->fs_info->endio_write_workers,
7073 &ordered->work);
7074 out_test:
7075 /*
7076 * our bio might span multiple ordered extents. If we haven't
7077 * completed the accounting for the whole dio, go back and try again
7078 */
7079 if (ordered_offset < dip->logical_offset + dip->bytes) {
7080 ordered_bytes = dip->logical_offset + dip->bytes -
7081 ordered_offset;
7082 ordered = NULL;
7083 goto again;
7084 }
7085 out_done:
7086 dio_bio = dip->dio_bio;
7087
7088 kfree(dip);
7089
7090 /* If we had an error make sure to clear the uptodate flag */
7091 if (err)
7092 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags);
7093 dio_end_io(dio_bio, err);
7094 bio_put(bio);
7095 }
7096
7097 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
7098 struct bio *bio, int mirror_num,
7099 unsigned long bio_flags, u64 offset)
7100 {
7101 int ret;
7102 struct btrfs_root *root = BTRFS_I(inode)->root;
7103 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
7104 BUG_ON(ret); /* -ENOMEM */
7105 return 0;
7106 }
7107
7108 static void btrfs_end_dio_bio(struct bio *bio, int err)
7109 {
7110 struct btrfs_dio_private *dip = bio->bi_private;
7111
7112 if (err) {
7113 btrfs_err(BTRFS_I(dip->inode)->root->fs_info,
7114 "direct IO failed ino %llu rw %lu sector %#Lx len %u err no %d",
7115 btrfs_ino(dip->inode), bio->bi_rw,
7116 (unsigned long long)bio->bi_iter.bi_sector,
7117 bio->bi_iter.bi_size, err);
7118 dip->errors = 1;
7119
7120 /*
7121 * before atomic variable goto zero, we must make sure
7122 * dip->errors is perceived to be set.
7123 */
7124 smp_mb__before_atomic_dec();
7125 }
7126
7127 /* if there are more bios still pending for this dio, just exit */
7128 if (!atomic_dec_and_test(&dip->pending_bios))
7129 goto out;
7130
7131 if (dip->errors) {
7132 bio_io_error(dip->orig_bio);
7133 } else {
7134 set_bit(BIO_UPTODATE, &dip->dio_bio->bi_flags);
7135 bio_endio(dip->orig_bio, 0);
7136 }
7137 out:
7138 bio_put(bio);
7139 }
7140
7141 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
7142 u64 first_sector, gfp_t gfp_flags)
7143 {
7144 int nr_vecs = bio_get_nr_vecs(bdev);
7145 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
7146 }
7147
7148 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
7149 int rw, u64 file_offset, int skip_sum,
7150 int async_submit)
7151 {
7152 struct btrfs_dio_private *dip = bio->bi_private;
7153 int write = rw & REQ_WRITE;
7154 struct btrfs_root *root = BTRFS_I(inode)->root;
7155 int ret;
7156
7157 if (async_submit)
7158 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
7159
7160 bio_get(bio);
7161
7162 if (!write) {
7163 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
7164 if (ret)
7165 goto err;
7166 }
7167
7168 if (skip_sum)
7169 goto map;
7170
7171 if (write && async_submit) {
7172 ret = btrfs_wq_submit_bio(root->fs_info,
7173 inode, rw, bio, 0, 0,
7174 file_offset,
7175 __btrfs_submit_bio_start_direct_io,
7176 __btrfs_submit_bio_done);
7177 goto err;
7178 } else if (write) {
7179 /*
7180 * If we aren't doing async submit, calculate the csum of the
7181 * bio now.
7182 */
7183 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
7184 if (ret)
7185 goto err;
7186 } else if (!skip_sum) {
7187 ret = btrfs_lookup_bio_sums_dio(root, inode, dip, bio,
7188 file_offset);
7189 if (ret)
7190 goto err;
7191 }
7192
7193 map:
7194 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
7195 err:
7196 bio_put(bio);
7197 return ret;
7198 }
7199
7200 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
7201 int skip_sum)
7202 {
7203 struct inode *inode = dip->inode;
7204 struct btrfs_root *root = BTRFS_I(inode)->root;
7205 struct bio *bio;
7206 struct bio *orig_bio = dip->orig_bio;
7207 struct bio_vec *bvec = orig_bio->bi_io_vec;
7208 u64 start_sector = orig_bio->bi_iter.bi_sector;
7209 u64 file_offset = dip->logical_offset;
7210 u64 submit_len = 0;
7211 u64 map_length;
7212 int nr_pages = 0;
7213 int ret = 0;
7214 int async_submit = 0;
7215
7216 map_length = orig_bio->bi_iter.bi_size;
7217 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
7218 &map_length, NULL, 0);
7219 if (ret) {
7220 bio_put(orig_bio);
7221 return -EIO;
7222 }
7223
7224 if (map_length >= orig_bio->bi_iter.bi_size) {
7225 bio = orig_bio;
7226 goto submit;
7227 }
7228
7229 /* async crcs make it difficult to collect full stripe writes. */
7230 if (btrfs_get_alloc_profile(root, 1) &
7231 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6))
7232 async_submit = 0;
7233 else
7234 async_submit = 1;
7235
7236 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
7237 if (!bio)
7238 return -ENOMEM;
7239 bio->bi_private = dip;
7240 bio->bi_end_io = btrfs_end_dio_bio;
7241 atomic_inc(&dip->pending_bios);
7242
7243 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
7244 if (unlikely(map_length < submit_len + bvec->bv_len ||
7245 bio_add_page(bio, bvec->bv_page, bvec->bv_len,
7246 bvec->bv_offset) < bvec->bv_len)) {
7247 /*
7248 * inc the count before we submit the bio so
7249 * we know the end IO handler won't happen before
7250 * we inc the count. Otherwise, the dip might get freed
7251 * before we're done setting it up
7252 */
7253 atomic_inc(&dip->pending_bios);
7254 ret = __btrfs_submit_dio_bio(bio, inode, rw,
7255 file_offset, skip_sum,
7256 async_submit);
7257 if (ret) {
7258 bio_put(bio);
7259 atomic_dec(&dip->pending_bios);
7260 goto out_err;
7261 }
7262
7263 start_sector += submit_len >> 9;
7264 file_offset += submit_len;
7265
7266 submit_len = 0;
7267 nr_pages = 0;
7268
7269 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
7270 start_sector, GFP_NOFS);
7271 if (!bio)
7272 goto out_err;
7273 bio->bi_private = dip;
7274 bio->bi_end_io = btrfs_end_dio_bio;
7275
7276 map_length = orig_bio->bi_iter.bi_size;
7277 ret = btrfs_map_block(root->fs_info, rw,
7278 start_sector << 9,
7279 &map_length, NULL, 0);
7280 if (ret) {
7281 bio_put(bio);
7282 goto out_err;
7283 }
7284 } else {
7285 submit_len += bvec->bv_len;
7286 nr_pages++;
7287 bvec++;
7288 }
7289 }
7290
7291 submit:
7292 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
7293 async_submit);
7294 if (!ret)
7295 return 0;
7296
7297 bio_put(bio);
7298 out_err:
7299 dip->errors = 1;
7300 /*
7301 * before atomic variable goto zero, we must
7302 * make sure dip->errors is perceived to be set.
7303 */
7304 smp_mb__before_atomic_dec();
7305 if (atomic_dec_and_test(&dip->pending_bios))
7306 bio_io_error(dip->orig_bio);
7307
7308 /* bio_end_io() will handle error, so we needn't return it */
7309 return 0;
7310 }
7311
7312 static void btrfs_submit_direct(int rw, struct bio *dio_bio,
7313 struct inode *inode, loff_t file_offset)
7314 {
7315 struct btrfs_root *root = BTRFS_I(inode)->root;
7316 struct btrfs_dio_private *dip;
7317 struct bio *io_bio;
7318 int skip_sum;
7319 int sum_len;
7320 int write = rw & REQ_WRITE;
7321 int ret = 0;
7322 u16 csum_size;
7323
7324 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
7325
7326 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
7327 if (!io_bio) {
7328 ret = -ENOMEM;
7329 goto free_ordered;
7330 }
7331
7332 if (!skip_sum && !write) {
7333 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
7334 sum_len = dio_bio->bi_iter.bi_size >>
7335 inode->i_sb->s_blocksize_bits;
7336 sum_len *= csum_size;
7337 } else {
7338 sum_len = 0;
7339 }
7340
7341 dip = kmalloc(sizeof(*dip) + sum_len, GFP_NOFS);
7342 if (!dip) {
7343 ret = -ENOMEM;
7344 goto free_io_bio;
7345 }
7346
7347 dip->private = dio_bio->bi_private;
7348 dip->inode = inode;
7349 dip->logical_offset = file_offset;
7350 dip->bytes = dio_bio->bi_iter.bi_size;
7351 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
7352 io_bio->bi_private = dip;
7353 dip->errors = 0;
7354 dip->orig_bio = io_bio;
7355 dip->dio_bio = dio_bio;
7356 atomic_set(&dip->pending_bios, 0);
7357
7358 if (write)
7359 io_bio->bi_end_io = btrfs_endio_direct_write;
7360 else
7361 io_bio->bi_end_io = btrfs_endio_direct_read;
7362
7363 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
7364 if (!ret)
7365 return;
7366
7367 free_io_bio:
7368 bio_put(io_bio);
7369
7370 free_ordered:
7371 /*
7372 * If this is a write, we need to clean up the reserved space and kill
7373 * the ordered extent.
7374 */
7375 if (write) {
7376 struct btrfs_ordered_extent *ordered;
7377 ordered = btrfs_lookup_ordered_extent(inode, file_offset);
7378 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
7379 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
7380 btrfs_free_reserved_extent(root, ordered->start,
7381 ordered->disk_len);
7382 btrfs_put_ordered_extent(ordered);
7383 btrfs_put_ordered_extent(ordered);
7384 }
7385 bio_endio(dio_bio, ret);
7386 }
7387
7388 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb,
7389 const struct iovec *iov, loff_t offset,
7390 unsigned long nr_segs)
7391 {
7392 int seg;
7393 int i;
7394 size_t size;
7395 unsigned long addr;
7396 unsigned blocksize_mask = root->sectorsize - 1;
7397 ssize_t retval = -EINVAL;
7398 loff_t end = offset;
7399
7400 if (offset & blocksize_mask)
7401 goto out;
7402
7403 /* Check the memory alignment. Blocks cannot straddle pages */
7404 for (seg = 0; seg < nr_segs; seg++) {
7405 addr = (unsigned long)iov[seg].iov_base;
7406 size = iov[seg].iov_len;
7407 end += size;
7408 if ((addr & blocksize_mask) || (size & blocksize_mask))
7409 goto out;
7410
7411 /* If this is a write we don't need to check anymore */
7412 if (rw & WRITE)
7413 continue;
7414
7415 /*
7416 * Check to make sure we don't have duplicate iov_base's in this
7417 * iovec, if so return EINVAL, otherwise we'll get csum errors
7418 * when reading back.
7419 */
7420 for (i = seg + 1; i < nr_segs; i++) {
7421 if (iov[seg].iov_base == iov[i].iov_base)
7422 goto out;
7423 }
7424 }
7425 retval = 0;
7426 out:
7427 return retval;
7428 }
7429
7430 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
7431 const struct iovec *iov, loff_t offset,
7432 unsigned long nr_segs)
7433 {
7434 struct file *file = iocb->ki_filp;
7435 struct inode *inode = file->f_mapping->host;
7436 size_t count = 0;
7437 int flags = 0;
7438 bool wakeup = true;
7439 bool relock = false;
7440 ssize_t ret;
7441
7442 if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
7443 offset, nr_segs))
7444 return 0;
7445
7446 atomic_inc(&inode->i_dio_count);
7447 smp_mb__after_atomic_inc();
7448
7449 /*
7450 * The generic stuff only does filemap_write_and_wait_range, which
7451 * isn't enough if we've written compressed pages to this area, so
7452 * we need to flush the dirty pages again to make absolutely sure
7453 * that any outstanding dirty pages are on disk.
7454 */
7455 count = iov_length(iov, nr_segs);
7456 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
7457 &BTRFS_I(inode)->runtime_flags))
7458 filemap_fdatawrite_range(inode->i_mapping, offset, count);
7459
7460 if (rw & WRITE) {
7461 /*
7462 * If the write DIO is beyond the EOF, we need update
7463 * the isize, but it is protected by i_mutex. So we can
7464 * not unlock the i_mutex at this case.
7465 */
7466 if (offset + count <= inode->i_size) {
7467 mutex_unlock(&inode->i_mutex);
7468 relock = true;
7469 }
7470 ret = btrfs_delalloc_reserve_space(inode, count);
7471 if (ret)
7472 goto out;
7473 } else if (unlikely(test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
7474 &BTRFS_I(inode)->runtime_flags))) {
7475 inode_dio_done(inode);
7476 flags = DIO_LOCKING | DIO_SKIP_HOLES;
7477 wakeup = false;
7478 }
7479
7480 ret = __blockdev_direct_IO(rw, iocb, inode,
7481 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
7482 iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
7483 btrfs_submit_direct, flags);
7484 if (rw & WRITE) {
7485 if (ret < 0 && ret != -EIOCBQUEUED)
7486 btrfs_delalloc_release_space(inode, count);
7487 else if (ret >= 0 && (size_t)ret < count)
7488 btrfs_delalloc_release_space(inode,
7489 count - (size_t)ret);
7490 else
7491 btrfs_delalloc_release_metadata(inode, 0);
7492 }
7493 out:
7494 if (wakeup)
7495 inode_dio_done(inode);
7496 if (relock)
7497 mutex_lock(&inode->i_mutex);
7498
7499 return ret;
7500 }
7501
7502 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
7503
7504 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
7505 __u64 start, __u64 len)
7506 {
7507 int ret;
7508
7509 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
7510 if (ret)
7511 return ret;
7512
7513 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
7514 }
7515
7516 int btrfs_readpage(struct file *file, struct page *page)
7517 {
7518 struct extent_io_tree *tree;
7519 tree = &BTRFS_I(page->mapping->host)->io_tree;
7520 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
7521 }
7522
7523 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
7524 {
7525 struct extent_io_tree *tree;
7526
7527
7528 if (current->flags & PF_MEMALLOC) {
7529 redirty_page_for_writepage(wbc, page);
7530 unlock_page(page);
7531 return 0;
7532 }
7533 tree = &BTRFS_I(page->mapping->host)->io_tree;
7534 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
7535 }
7536
7537 static int btrfs_writepages(struct address_space *mapping,
7538 struct writeback_control *wbc)
7539 {
7540 struct extent_io_tree *tree;
7541
7542 tree = &BTRFS_I(mapping->host)->io_tree;
7543 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
7544 }
7545
7546 static int
7547 btrfs_readpages(struct file *file, struct address_space *mapping,
7548 struct list_head *pages, unsigned nr_pages)
7549 {
7550 struct extent_io_tree *tree;
7551 tree = &BTRFS_I(mapping->host)->io_tree;
7552 return extent_readpages(tree, mapping, pages, nr_pages,
7553 btrfs_get_extent);
7554 }
7555 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
7556 {
7557 struct extent_io_tree *tree;
7558 struct extent_map_tree *map;
7559 int ret;
7560
7561 tree = &BTRFS_I(page->mapping->host)->io_tree;
7562 map = &BTRFS_I(page->mapping->host)->extent_tree;
7563 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
7564 if (ret == 1) {
7565 ClearPagePrivate(page);
7566 set_page_private(page, 0);
7567 page_cache_release(page);
7568 }
7569 return ret;
7570 }
7571
7572 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
7573 {
7574 if (PageWriteback(page) || PageDirty(page))
7575 return 0;
7576 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
7577 }
7578
7579 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
7580 unsigned int length)
7581 {
7582 struct inode *inode = page->mapping->host;
7583 struct extent_io_tree *tree;
7584 struct btrfs_ordered_extent *ordered;
7585 struct extent_state *cached_state = NULL;
7586 u64 page_start = page_offset(page);
7587 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
7588 int inode_evicting = inode->i_state & I_FREEING;
7589
7590 /*
7591 * we have the page locked, so new writeback can't start,
7592 * and the dirty bit won't be cleared while we are here.
7593 *
7594 * Wait for IO on this page so that we can safely clear
7595 * the PagePrivate2 bit and do ordered accounting
7596 */
7597 wait_on_page_writeback(page);
7598
7599 tree = &BTRFS_I(inode)->io_tree;
7600 if (offset) {
7601 btrfs_releasepage(page, GFP_NOFS);
7602 return;
7603 }
7604
7605 if (!inode_evicting)
7606 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
7607 ordered = btrfs_lookup_ordered_extent(inode, page_start);
7608 if (ordered) {
7609 /*
7610 * IO on this page will never be started, so we need
7611 * to account for any ordered extents now
7612 */
7613 if (!inode_evicting)
7614 clear_extent_bit(tree, page_start, page_end,
7615 EXTENT_DIRTY | EXTENT_DELALLOC |
7616 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
7617 EXTENT_DEFRAG, 1, 0, &cached_state,
7618 GFP_NOFS);
7619 /*
7620 * whoever cleared the private bit is responsible
7621 * for the finish_ordered_io
7622 */
7623 if (TestClearPagePrivate2(page)) {
7624 struct btrfs_ordered_inode_tree *tree;
7625 u64 new_len;
7626
7627 tree = &BTRFS_I(inode)->ordered_tree;
7628
7629 spin_lock_irq(&tree->lock);
7630 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
7631 new_len = page_start - ordered->file_offset;
7632 if (new_len < ordered->truncated_len)
7633 ordered->truncated_len = new_len;
7634 spin_unlock_irq(&tree->lock);
7635
7636 if (btrfs_dec_test_ordered_pending(inode, &ordered,
7637 page_start,
7638 PAGE_CACHE_SIZE, 1))
7639 btrfs_finish_ordered_io(ordered);
7640 }
7641 btrfs_put_ordered_extent(ordered);
7642 if (!inode_evicting) {
7643 cached_state = NULL;
7644 lock_extent_bits(tree, page_start, page_end, 0,
7645 &cached_state);
7646 }
7647 }
7648
7649 if (!inode_evicting) {
7650 clear_extent_bit(tree, page_start, page_end,
7651 EXTENT_LOCKED | EXTENT_DIRTY |
7652 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
7653 EXTENT_DEFRAG, 1, 1,
7654 &cached_state, GFP_NOFS);
7655
7656 __btrfs_releasepage(page, GFP_NOFS);
7657 }
7658
7659 ClearPageChecked(page);
7660 if (PagePrivate(page)) {
7661 ClearPagePrivate(page);
7662 set_page_private(page, 0);
7663 page_cache_release(page);
7664 }
7665 }
7666
7667 /*
7668 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
7669 * called from a page fault handler when a page is first dirtied. Hence we must
7670 * be careful to check for EOF conditions here. We set the page up correctly
7671 * for a written page which means we get ENOSPC checking when writing into
7672 * holes and correct delalloc and unwritten extent mapping on filesystems that
7673 * support these features.
7674 *
7675 * We are not allowed to take the i_mutex here so we have to play games to
7676 * protect against truncate races as the page could now be beyond EOF. Because
7677 * vmtruncate() writes the inode size before removing pages, once we have the
7678 * page lock we can determine safely if the page is beyond EOF. If it is not
7679 * beyond EOF, then the page is guaranteed safe against truncation until we
7680 * unlock the page.
7681 */
7682 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
7683 {
7684 struct page *page = vmf->page;
7685 struct inode *inode = file_inode(vma->vm_file);
7686 struct btrfs_root *root = BTRFS_I(inode)->root;
7687 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7688 struct btrfs_ordered_extent *ordered;
7689 struct extent_state *cached_state = NULL;
7690 char *kaddr;
7691 unsigned long zero_start;
7692 loff_t size;
7693 int ret;
7694 int reserved = 0;
7695 u64 page_start;
7696 u64 page_end;
7697
7698 sb_start_pagefault(inode->i_sb);
7699 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
7700 if (!ret) {
7701 ret = file_update_time(vma->vm_file);
7702 reserved = 1;
7703 }
7704 if (ret) {
7705 if (ret == -ENOMEM)
7706 ret = VM_FAULT_OOM;
7707 else /* -ENOSPC, -EIO, etc */
7708 ret = VM_FAULT_SIGBUS;
7709 if (reserved)
7710 goto out;
7711 goto out_noreserve;
7712 }
7713
7714 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
7715 again:
7716 lock_page(page);
7717 size = i_size_read(inode);
7718 page_start = page_offset(page);
7719 page_end = page_start + PAGE_CACHE_SIZE - 1;
7720
7721 if ((page->mapping != inode->i_mapping) ||
7722 (page_start >= size)) {
7723 /* page got truncated out from underneath us */
7724 goto out_unlock;
7725 }
7726 wait_on_page_writeback(page);
7727
7728 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
7729 set_page_extent_mapped(page);
7730
7731 /*
7732 * we can't set the delalloc bits if there are pending ordered
7733 * extents. Drop our locks and wait for them to finish
7734 */
7735 ordered = btrfs_lookup_ordered_extent(inode, page_start);
7736 if (ordered) {
7737 unlock_extent_cached(io_tree, page_start, page_end,
7738 &cached_state, GFP_NOFS);
7739 unlock_page(page);
7740 btrfs_start_ordered_extent(inode, ordered, 1);
7741 btrfs_put_ordered_extent(ordered);
7742 goto again;
7743 }
7744
7745 /*
7746 * XXX - page_mkwrite gets called every time the page is dirtied, even
7747 * if it was already dirty, so for space accounting reasons we need to
7748 * clear any delalloc bits for the range we are fixing to save. There
7749 * is probably a better way to do this, but for now keep consistent with
7750 * prepare_pages in the normal write path.
7751 */
7752 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
7753 EXTENT_DIRTY | EXTENT_DELALLOC |
7754 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
7755 0, 0, &cached_state, GFP_NOFS);
7756
7757 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
7758 &cached_state);
7759 if (ret) {
7760 unlock_extent_cached(io_tree, page_start, page_end,
7761 &cached_state, GFP_NOFS);
7762 ret = VM_FAULT_SIGBUS;
7763 goto out_unlock;
7764 }
7765 ret = 0;
7766
7767 /* page is wholly or partially inside EOF */
7768 if (page_start + PAGE_CACHE_SIZE > size)
7769 zero_start = size & ~PAGE_CACHE_MASK;
7770 else
7771 zero_start = PAGE_CACHE_SIZE;
7772
7773 if (zero_start != PAGE_CACHE_SIZE) {
7774 kaddr = kmap(page);
7775 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
7776 flush_dcache_page(page);
7777 kunmap(page);
7778 }
7779 ClearPageChecked(page);
7780 set_page_dirty(page);
7781 SetPageUptodate(page);
7782
7783 BTRFS_I(inode)->last_trans = root->fs_info->generation;
7784 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
7785 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
7786
7787 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
7788
7789 out_unlock:
7790 if (!ret) {
7791 sb_end_pagefault(inode->i_sb);
7792 return VM_FAULT_LOCKED;
7793 }
7794 unlock_page(page);
7795 out:
7796 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
7797 out_noreserve:
7798 sb_end_pagefault(inode->i_sb);
7799 return ret;
7800 }
7801
7802 static int btrfs_truncate(struct inode *inode)
7803 {
7804 struct btrfs_root *root = BTRFS_I(inode)->root;
7805 struct btrfs_block_rsv *rsv;
7806 int ret = 0;
7807 int err = 0;
7808 struct btrfs_trans_handle *trans;
7809 u64 mask = root->sectorsize - 1;
7810 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
7811
7812 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
7813 (u64)-1);
7814 if (ret)
7815 return ret;
7816
7817 /*
7818 * Yes ladies and gentelment, this is indeed ugly. The fact is we have
7819 * 3 things going on here
7820 *
7821 * 1) We need to reserve space for our orphan item and the space to
7822 * delete our orphan item. Lord knows we don't want to have a dangling
7823 * orphan item because we didn't reserve space to remove it.
7824 *
7825 * 2) We need to reserve space to update our inode.
7826 *
7827 * 3) We need to have something to cache all the space that is going to
7828 * be free'd up by the truncate operation, but also have some slack
7829 * space reserved in case it uses space during the truncate (thank you
7830 * very much snapshotting).
7831 *
7832 * And we need these to all be seperate. The fact is we can use alot of
7833 * space doing the truncate, and we have no earthly idea how much space
7834 * we will use, so we need the truncate reservation to be seperate so it
7835 * doesn't end up using space reserved for updating the inode or
7836 * removing the orphan item. We also need to be able to stop the
7837 * transaction and start a new one, which means we need to be able to
7838 * update the inode several times, and we have no idea of knowing how
7839 * many times that will be, so we can't just reserve 1 item for the
7840 * entirety of the opration, so that has to be done seperately as well.
7841 * Then there is the orphan item, which does indeed need to be held on
7842 * to for the whole operation, and we need nobody to touch this reserved
7843 * space except the orphan code.
7844 *
7845 * So that leaves us with
7846 *
7847 * 1) root->orphan_block_rsv - for the orphan deletion.
7848 * 2) rsv - for the truncate reservation, which we will steal from the
7849 * transaction reservation.
7850 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
7851 * updating the inode.
7852 */
7853 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
7854 if (!rsv)
7855 return -ENOMEM;
7856 rsv->size = min_size;
7857 rsv->failfast = 1;
7858
7859 /*
7860 * 1 for the truncate slack space
7861 * 1 for updating the inode.
7862 */
7863 trans = btrfs_start_transaction(root, 2);
7864 if (IS_ERR(trans)) {
7865 err = PTR_ERR(trans);
7866 goto out;
7867 }
7868
7869 /* Migrate the slack space for the truncate to our reserve */
7870 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
7871 min_size);
7872 BUG_ON(ret);
7873
7874 /*
7875 * setattr is responsible for setting the ordered_data_close flag,
7876 * but that is only tested during the last file release. That
7877 * could happen well after the next commit, leaving a great big
7878 * window where new writes may get lost if someone chooses to write
7879 * to this file after truncating to zero
7880 *
7881 * The inode doesn't have any dirty data here, and so if we commit
7882 * this is a noop. If someone immediately starts writing to the inode
7883 * it is very likely we'll catch some of their writes in this
7884 * transaction, and the commit will find this file on the ordered
7885 * data list with good things to send down.
7886 *
7887 * This is a best effort solution, there is still a window where
7888 * using truncate to replace the contents of the file will
7889 * end up with a zero length file after a crash.
7890 */
7891 if (inode->i_size == 0 && test_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
7892 &BTRFS_I(inode)->runtime_flags))
7893 btrfs_add_ordered_operation(trans, root, inode);
7894
7895 /*
7896 * So if we truncate and then write and fsync we normally would just
7897 * write the extents that changed, which is a problem if we need to
7898 * first truncate that entire inode. So set this flag so we write out
7899 * all of the extents in the inode to the sync log so we're completely
7900 * safe.
7901 */
7902 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
7903 trans->block_rsv = rsv;
7904
7905 while (1) {
7906 ret = btrfs_truncate_inode_items(trans, root, inode,
7907 inode->i_size,
7908 BTRFS_EXTENT_DATA_KEY);
7909 if (ret != -ENOSPC) {
7910 err = ret;
7911 break;
7912 }
7913
7914 trans->block_rsv = &root->fs_info->trans_block_rsv;
7915 ret = btrfs_update_inode(trans, root, inode);
7916 if (ret) {
7917 err = ret;
7918 break;
7919 }
7920
7921 btrfs_end_transaction(trans, root);
7922 btrfs_btree_balance_dirty(root);
7923
7924 trans = btrfs_start_transaction(root, 2);
7925 if (IS_ERR(trans)) {
7926 ret = err = PTR_ERR(trans);
7927 trans = NULL;
7928 break;
7929 }
7930
7931 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
7932 rsv, min_size);
7933 BUG_ON(ret); /* shouldn't happen */
7934 trans->block_rsv = rsv;
7935 }
7936
7937 if (ret == 0 && inode->i_nlink > 0) {
7938 trans->block_rsv = root->orphan_block_rsv;
7939 ret = btrfs_orphan_del(trans, inode);
7940 if (ret)
7941 err = ret;
7942 }
7943
7944 if (trans) {
7945 trans->block_rsv = &root->fs_info->trans_block_rsv;
7946 ret = btrfs_update_inode(trans, root, inode);
7947 if (ret && !err)
7948 err = ret;
7949
7950 ret = btrfs_end_transaction(trans, root);
7951 btrfs_btree_balance_dirty(root);
7952 }
7953
7954 out:
7955 btrfs_free_block_rsv(root, rsv);
7956
7957 if (ret && !err)
7958 err = ret;
7959
7960 return err;
7961 }
7962
7963 /*
7964 * create a new subvolume directory/inode (helper for the ioctl).
7965 */
7966 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
7967 struct btrfs_root *new_root,
7968 struct btrfs_root *parent_root,
7969 u64 new_dirid)
7970 {
7971 struct inode *inode;
7972 int err;
7973 u64 index = 0;
7974
7975 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
7976 new_dirid, new_dirid,
7977 S_IFDIR | (~current_umask() & S_IRWXUGO),
7978 &index);
7979 if (IS_ERR(inode))
7980 return PTR_ERR(inode);
7981 inode->i_op = &btrfs_dir_inode_operations;
7982 inode->i_fop = &btrfs_dir_file_operations;
7983
7984 set_nlink(inode, 1);
7985 btrfs_i_size_write(inode, 0);
7986
7987 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
7988 if (err)
7989 btrfs_err(new_root->fs_info,
7990 "error inheriting subvolume %llu properties: %d\n",
7991 new_root->root_key.objectid, err);
7992
7993 err = btrfs_update_inode(trans, new_root, inode);
7994
7995 iput(inode);
7996 return err;
7997 }
7998
7999 struct inode *btrfs_alloc_inode(struct super_block *sb)
8000 {
8001 struct btrfs_inode *ei;
8002 struct inode *inode;
8003
8004 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
8005 if (!ei)
8006 return NULL;
8007
8008 ei->root = NULL;
8009 ei->generation = 0;
8010 ei->last_trans = 0;
8011 ei->last_sub_trans = 0;
8012 ei->logged_trans = 0;
8013 ei->delalloc_bytes = 0;
8014 ei->disk_i_size = 0;
8015 ei->flags = 0;
8016 ei->csum_bytes = 0;
8017 ei->index_cnt = (u64)-1;
8018 ei->dir_index = 0;
8019 ei->last_unlink_trans = 0;
8020 ei->last_log_commit = 0;
8021
8022 spin_lock_init(&ei->lock);
8023 ei->outstanding_extents = 0;
8024 ei->reserved_extents = 0;
8025
8026 ei->runtime_flags = 0;
8027 ei->force_compress = BTRFS_COMPRESS_NONE;
8028
8029 ei->delayed_node = NULL;
8030
8031 inode = &ei->vfs_inode;
8032 extent_map_tree_init(&ei->extent_tree);
8033 extent_io_tree_init(&ei->io_tree, &inode->i_data);
8034 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
8035 ei->io_tree.track_uptodate = 1;
8036 ei->io_failure_tree.track_uptodate = 1;
8037 atomic_set(&ei->sync_writers, 0);
8038 mutex_init(&ei->log_mutex);
8039 mutex_init(&ei->delalloc_mutex);
8040 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
8041 INIT_LIST_HEAD(&ei->delalloc_inodes);
8042 INIT_LIST_HEAD(&ei->ordered_operations);
8043 RB_CLEAR_NODE(&ei->rb_node);
8044
8045 return inode;
8046 }
8047
8048 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
8049 void btrfs_test_destroy_inode(struct inode *inode)
8050 {
8051 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
8052 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
8053 }
8054 #endif
8055
8056 static void btrfs_i_callback(struct rcu_head *head)
8057 {
8058 struct inode *inode = container_of(head, struct inode, i_rcu);
8059 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
8060 }
8061
8062 void btrfs_destroy_inode(struct inode *inode)
8063 {
8064 struct btrfs_ordered_extent *ordered;
8065 struct btrfs_root *root = BTRFS_I(inode)->root;
8066
8067 WARN_ON(!hlist_empty(&inode->i_dentry));
8068 WARN_ON(inode->i_data.nrpages);
8069 WARN_ON(BTRFS_I(inode)->outstanding_extents);
8070 WARN_ON(BTRFS_I(inode)->reserved_extents);
8071 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
8072 WARN_ON(BTRFS_I(inode)->csum_bytes);
8073
8074 /*
8075 * This can happen where we create an inode, but somebody else also
8076 * created the same inode and we need to destroy the one we already
8077 * created.
8078 */
8079 if (!root)
8080 goto free;
8081
8082 /*
8083 * Make sure we're properly removed from the ordered operation
8084 * lists.
8085 */
8086 smp_mb();
8087 if (!list_empty(&BTRFS_I(inode)->ordered_operations)) {
8088 spin_lock(&root->fs_info->ordered_root_lock);
8089 list_del_init(&BTRFS_I(inode)->ordered_operations);
8090 spin_unlock(&root->fs_info->ordered_root_lock);
8091 }
8092
8093 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
8094 &BTRFS_I(inode)->runtime_flags)) {
8095 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
8096 btrfs_ino(inode));
8097 atomic_dec(&root->orphan_inodes);
8098 }
8099
8100 while (1) {
8101 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
8102 if (!ordered)
8103 break;
8104 else {
8105 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
8106 ordered->file_offset, ordered->len);
8107 btrfs_remove_ordered_extent(inode, ordered);
8108 btrfs_put_ordered_extent(ordered);
8109 btrfs_put_ordered_extent(ordered);
8110 }
8111 }
8112 inode_tree_del(inode);
8113 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
8114 free:
8115 call_rcu(&inode->i_rcu, btrfs_i_callback);
8116 }
8117
8118 int btrfs_drop_inode(struct inode *inode)
8119 {
8120 struct btrfs_root *root = BTRFS_I(inode)->root;
8121
8122 if (root == NULL)
8123 return 1;
8124
8125 /* the snap/subvol tree is on deleting */
8126 if (btrfs_root_refs(&root->root_item) == 0)
8127 return 1;
8128 else
8129 return generic_drop_inode(inode);
8130 }
8131
8132 static void init_once(void *foo)
8133 {
8134 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
8135
8136 inode_init_once(&ei->vfs_inode);
8137 }
8138
8139 void btrfs_destroy_cachep(void)
8140 {
8141 /*
8142 * Make sure all delayed rcu free inodes are flushed before we
8143 * destroy cache.
8144 */
8145 rcu_barrier();
8146 if (btrfs_inode_cachep)
8147 kmem_cache_destroy(btrfs_inode_cachep);
8148 if (btrfs_trans_handle_cachep)
8149 kmem_cache_destroy(btrfs_trans_handle_cachep);
8150 if (btrfs_transaction_cachep)
8151 kmem_cache_destroy(btrfs_transaction_cachep);
8152 if (btrfs_path_cachep)
8153 kmem_cache_destroy(btrfs_path_cachep);
8154 if (btrfs_free_space_cachep)
8155 kmem_cache_destroy(btrfs_free_space_cachep);
8156 if (btrfs_delalloc_work_cachep)
8157 kmem_cache_destroy(btrfs_delalloc_work_cachep);
8158 }
8159
8160 int btrfs_init_cachep(void)
8161 {
8162 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
8163 sizeof(struct btrfs_inode), 0,
8164 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
8165 if (!btrfs_inode_cachep)
8166 goto fail;
8167
8168 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
8169 sizeof(struct btrfs_trans_handle), 0,
8170 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8171 if (!btrfs_trans_handle_cachep)
8172 goto fail;
8173
8174 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
8175 sizeof(struct btrfs_transaction), 0,
8176 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8177 if (!btrfs_transaction_cachep)
8178 goto fail;
8179
8180 btrfs_path_cachep = kmem_cache_create("btrfs_path",
8181 sizeof(struct btrfs_path), 0,
8182 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8183 if (!btrfs_path_cachep)
8184 goto fail;
8185
8186 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
8187 sizeof(struct btrfs_free_space), 0,
8188 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8189 if (!btrfs_free_space_cachep)
8190 goto fail;
8191
8192 btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work",
8193 sizeof(struct btrfs_delalloc_work), 0,
8194 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
8195 NULL);
8196 if (!btrfs_delalloc_work_cachep)
8197 goto fail;
8198
8199 return 0;
8200 fail:
8201 btrfs_destroy_cachep();
8202 return -ENOMEM;
8203 }
8204
8205 static int btrfs_getattr(struct vfsmount *mnt,
8206 struct dentry *dentry, struct kstat *stat)
8207 {
8208 u64 delalloc_bytes;
8209 struct inode *inode = dentry->d_inode;
8210 u32 blocksize = inode->i_sb->s_blocksize;
8211
8212 generic_fillattr(inode, stat);
8213 stat->dev = BTRFS_I(inode)->root->anon_dev;
8214 stat->blksize = PAGE_CACHE_SIZE;
8215
8216 spin_lock(&BTRFS_I(inode)->lock);
8217 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
8218 spin_unlock(&BTRFS_I(inode)->lock);
8219 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
8220 ALIGN(delalloc_bytes, blocksize)) >> 9;
8221 return 0;
8222 }
8223
8224 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
8225 struct inode *new_dir, struct dentry *new_dentry)
8226 {
8227 struct btrfs_trans_handle *trans;
8228 struct btrfs_root *root = BTRFS_I(old_dir)->root;
8229 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
8230 struct inode *new_inode = new_dentry->d_inode;
8231 struct inode *old_inode = old_dentry->d_inode;
8232 struct timespec ctime = CURRENT_TIME;
8233 u64 index = 0;
8234 u64 root_objectid;
8235 int ret;
8236 u64 old_ino = btrfs_ino(old_inode);
8237
8238 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
8239 return -EPERM;
8240
8241 /* we only allow rename subvolume link between subvolumes */
8242 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
8243 return -EXDEV;
8244
8245 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
8246 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
8247 return -ENOTEMPTY;
8248
8249 if (S_ISDIR(old_inode->i_mode) && new_inode &&
8250 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
8251 return -ENOTEMPTY;
8252
8253
8254 /* check for collisions, even if the name isn't there */
8255 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
8256 new_dentry->d_name.name,
8257 new_dentry->d_name.len);
8258
8259 if (ret) {
8260 if (ret == -EEXIST) {
8261 /* we shouldn't get
8262 * eexist without a new_inode */
8263 if (WARN_ON(!new_inode)) {
8264 return ret;
8265 }
8266 } else {
8267 /* maybe -EOVERFLOW */
8268 return ret;
8269 }
8270 }
8271 ret = 0;
8272
8273 /*
8274 * we're using rename to replace one file with another.
8275 * and the replacement file is large. Start IO on it now so
8276 * we don't add too much work to the end of the transaction
8277 */
8278 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size &&
8279 old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
8280 filemap_flush(old_inode->i_mapping);
8281
8282 /* close the racy window with snapshot create/destroy ioctl */
8283 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
8284 down_read(&root->fs_info->subvol_sem);
8285 /*
8286 * We want to reserve the absolute worst case amount of items. So if
8287 * both inodes are subvols and we need to unlink them then that would
8288 * require 4 item modifications, but if they are both normal inodes it
8289 * would require 5 item modifications, so we'll assume their normal
8290 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
8291 * should cover the worst case number of items we'll modify.
8292 */
8293 trans = btrfs_start_transaction(root, 11);
8294 if (IS_ERR(trans)) {
8295 ret = PTR_ERR(trans);
8296 goto out_notrans;
8297 }
8298
8299 if (dest != root)
8300 btrfs_record_root_in_trans(trans, dest);
8301
8302 ret = btrfs_set_inode_index(new_dir, &index);
8303 if (ret)
8304 goto out_fail;
8305
8306 BTRFS_I(old_inode)->dir_index = 0ULL;
8307 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
8308 /* force full log commit if subvolume involved. */
8309 root->fs_info->last_trans_log_full_commit = trans->transid;
8310 } else {
8311 ret = btrfs_insert_inode_ref(trans, dest,
8312 new_dentry->d_name.name,
8313 new_dentry->d_name.len,
8314 old_ino,
8315 btrfs_ino(new_dir), index);
8316 if (ret)
8317 goto out_fail;
8318 /*
8319 * this is an ugly little race, but the rename is required
8320 * to make sure that if we crash, the inode is either at the
8321 * old name or the new one. pinning the log transaction lets
8322 * us make sure we don't allow a log commit to come in after
8323 * we unlink the name but before we add the new name back in.
8324 */
8325 btrfs_pin_log_trans(root);
8326 }
8327 /*
8328 * make sure the inode gets flushed if it is replacing
8329 * something.
8330 */
8331 if (new_inode && new_inode->i_size && S_ISREG(old_inode->i_mode))
8332 btrfs_add_ordered_operation(trans, root, old_inode);
8333
8334 inode_inc_iversion(old_dir);
8335 inode_inc_iversion(new_dir);
8336 inode_inc_iversion(old_inode);
8337 old_dir->i_ctime = old_dir->i_mtime = ctime;
8338 new_dir->i_ctime = new_dir->i_mtime = ctime;
8339 old_inode->i_ctime = ctime;
8340
8341 if (old_dentry->d_parent != new_dentry->d_parent)
8342 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
8343
8344 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
8345 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
8346 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
8347 old_dentry->d_name.name,
8348 old_dentry->d_name.len);
8349 } else {
8350 ret = __btrfs_unlink_inode(trans, root, old_dir,
8351 old_dentry->d_inode,
8352 old_dentry->d_name.name,
8353 old_dentry->d_name.len);
8354 if (!ret)
8355 ret = btrfs_update_inode(trans, root, old_inode);
8356 }
8357 if (ret) {
8358 btrfs_abort_transaction(trans, root, ret);
8359 goto out_fail;
8360 }
8361
8362 if (new_inode) {
8363 inode_inc_iversion(new_inode);
8364 new_inode->i_ctime = CURRENT_TIME;
8365 if (unlikely(btrfs_ino(new_inode) ==
8366 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
8367 root_objectid = BTRFS_I(new_inode)->location.objectid;
8368 ret = btrfs_unlink_subvol(trans, dest, new_dir,
8369 root_objectid,
8370 new_dentry->d_name.name,
8371 new_dentry->d_name.len);
8372 BUG_ON(new_inode->i_nlink == 0);
8373 } else {
8374 ret = btrfs_unlink_inode(trans, dest, new_dir,
8375 new_dentry->d_inode,
8376 new_dentry->d_name.name,
8377 new_dentry->d_name.len);
8378 }
8379 if (!ret && new_inode->i_nlink == 0)
8380 ret = btrfs_orphan_add(trans, new_dentry->d_inode);
8381 if (ret) {
8382 btrfs_abort_transaction(trans, root, ret);
8383 goto out_fail;
8384 }
8385 }
8386
8387 ret = btrfs_add_link(trans, new_dir, old_inode,
8388 new_dentry->d_name.name,
8389 new_dentry->d_name.len, 0, index);
8390 if (ret) {
8391 btrfs_abort_transaction(trans, root, ret);
8392 goto out_fail;
8393 }
8394
8395 if (old_inode->i_nlink == 1)
8396 BTRFS_I(old_inode)->dir_index = index;
8397
8398 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
8399 struct dentry *parent = new_dentry->d_parent;
8400 btrfs_log_new_name(trans, old_inode, old_dir, parent);
8401 btrfs_end_log_trans(root);
8402 }
8403 out_fail:
8404 btrfs_end_transaction(trans, root);
8405 out_notrans:
8406 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
8407 up_read(&root->fs_info->subvol_sem);
8408
8409 return ret;
8410 }
8411
8412 static void btrfs_run_delalloc_work(struct btrfs_work *work)
8413 {
8414 struct btrfs_delalloc_work *delalloc_work;
8415 struct inode *inode;
8416
8417 delalloc_work = container_of(work, struct btrfs_delalloc_work,
8418 work);
8419 inode = delalloc_work->inode;
8420 if (delalloc_work->wait) {
8421 btrfs_wait_ordered_range(inode, 0, (u64)-1);
8422 } else {
8423 filemap_flush(inode->i_mapping);
8424 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8425 &BTRFS_I(inode)->runtime_flags))
8426 filemap_flush(inode->i_mapping);
8427 }
8428
8429 if (delalloc_work->delay_iput)
8430 btrfs_add_delayed_iput(inode);
8431 else
8432 iput(inode);
8433 complete(&delalloc_work->completion);
8434 }
8435
8436 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
8437 int wait, int delay_iput)
8438 {
8439 struct btrfs_delalloc_work *work;
8440
8441 work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS);
8442 if (!work)
8443 return NULL;
8444
8445 init_completion(&work->completion);
8446 INIT_LIST_HEAD(&work->list);
8447 work->inode = inode;
8448 work->wait = wait;
8449 work->delay_iput = delay_iput;
8450 btrfs_init_work(&work->work, btrfs_run_delalloc_work, NULL, NULL);
8451
8452 return work;
8453 }
8454
8455 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
8456 {
8457 wait_for_completion(&work->completion);
8458 kmem_cache_free(btrfs_delalloc_work_cachep, work);
8459 }
8460
8461 /*
8462 * some fairly slow code that needs optimization. This walks the list
8463 * of all the inodes with pending delalloc and forces them to disk.
8464 */
8465 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
8466 int nr)
8467 {
8468 struct btrfs_inode *binode;
8469 struct inode *inode;
8470 struct btrfs_delalloc_work *work, *next;
8471 struct list_head works;
8472 struct list_head splice;
8473 int ret = 0;
8474
8475 INIT_LIST_HEAD(&works);
8476 INIT_LIST_HEAD(&splice);
8477
8478 mutex_lock(&root->delalloc_mutex);
8479 spin_lock(&root->delalloc_lock);
8480 list_splice_init(&root->delalloc_inodes, &splice);
8481 while (!list_empty(&splice)) {
8482 binode = list_entry(splice.next, struct btrfs_inode,
8483 delalloc_inodes);
8484
8485 list_move_tail(&binode->delalloc_inodes,
8486 &root->delalloc_inodes);
8487 inode = igrab(&binode->vfs_inode);
8488 if (!inode) {
8489 cond_resched_lock(&root->delalloc_lock);
8490 continue;
8491 }
8492 spin_unlock(&root->delalloc_lock);
8493
8494 work = btrfs_alloc_delalloc_work(inode, 0, delay_iput);
8495 if (unlikely(!work)) {
8496 if (delay_iput)
8497 btrfs_add_delayed_iput(inode);
8498 else
8499 iput(inode);
8500 ret = -ENOMEM;
8501 goto out;
8502 }
8503 list_add_tail(&work->list, &works);
8504 btrfs_queue_work(root->fs_info->flush_workers,
8505 &work->work);
8506 ret++;
8507 if (nr != -1 && ret >= nr)
8508 goto out;
8509 cond_resched();
8510 spin_lock(&root->delalloc_lock);
8511 }
8512 spin_unlock(&root->delalloc_lock);
8513
8514 out:
8515 list_for_each_entry_safe(work, next, &works, list) {
8516 list_del_init(&work->list);
8517 btrfs_wait_and_free_delalloc_work(work);
8518 }
8519
8520 if (!list_empty_careful(&splice)) {
8521 spin_lock(&root->delalloc_lock);
8522 list_splice_tail(&splice, &root->delalloc_inodes);
8523 spin_unlock(&root->delalloc_lock);
8524 }
8525 mutex_unlock(&root->delalloc_mutex);
8526 return ret;
8527 }
8528
8529 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
8530 {
8531 int ret;
8532
8533 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
8534 return -EROFS;
8535
8536 ret = __start_delalloc_inodes(root, delay_iput, -1);
8537 if (ret > 0)
8538 ret = 0;
8539 /*
8540 * the filemap_flush will queue IO into the worker threads, but
8541 * we have to make sure the IO is actually started and that
8542 * ordered extents get created before we return
8543 */
8544 atomic_inc(&root->fs_info->async_submit_draining);
8545 while (atomic_read(&root->fs_info->nr_async_submits) ||
8546 atomic_read(&root->fs_info->async_delalloc_pages)) {
8547 wait_event(root->fs_info->async_submit_wait,
8548 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
8549 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
8550 }
8551 atomic_dec(&root->fs_info->async_submit_draining);
8552 return ret;
8553 }
8554
8555 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
8556 int nr)
8557 {
8558 struct btrfs_root *root;
8559 struct list_head splice;
8560 int ret;
8561
8562 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
8563 return -EROFS;
8564
8565 INIT_LIST_HEAD(&splice);
8566
8567 mutex_lock(&fs_info->delalloc_root_mutex);
8568 spin_lock(&fs_info->delalloc_root_lock);
8569 list_splice_init(&fs_info->delalloc_roots, &splice);
8570 while (!list_empty(&splice) && nr) {
8571 root = list_first_entry(&splice, struct btrfs_root,
8572 delalloc_root);
8573 root = btrfs_grab_fs_root(root);
8574 BUG_ON(!root);
8575 list_move_tail(&root->delalloc_root,
8576 &fs_info->delalloc_roots);
8577 spin_unlock(&fs_info->delalloc_root_lock);
8578
8579 ret = __start_delalloc_inodes(root, delay_iput, nr);
8580 btrfs_put_fs_root(root);
8581 if (ret < 0)
8582 goto out;
8583
8584 if (nr != -1) {
8585 nr -= ret;
8586 WARN_ON(nr < 0);
8587 }
8588 spin_lock(&fs_info->delalloc_root_lock);
8589 }
8590 spin_unlock(&fs_info->delalloc_root_lock);
8591
8592 ret = 0;
8593 atomic_inc(&fs_info->async_submit_draining);
8594 while (atomic_read(&fs_info->nr_async_submits) ||
8595 atomic_read(&fs_info->async_delalloc_pages)) {
8596 wait_event(fs_info->async_submit_wait,
8597 (atomic_read(&fs_info->nr_async_submits) == 0 &&
8598 atomic_read(&fs_info->async_delalloc_pages) == 0));
8599 }
8600 atomic_dec(&fs_info->async_submit_draining);
8601 out:
8602 if (!list_empty_careful(&splice)) {
8603 spin_lock(&fs_info->delalloc_root_lock);
8604 list_splice_tail(&splice, &fs_info->delalloc_roots);
8605 spin_unlock(&fs_info->delalloc_root_lock);
8606 }
8607 mutex_unlock(&fs_info->delalloc_root_mutex);
8608 return ret;
8609 }
8610
8611 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
8612 const char *symname)
8613 {
8614 struct btrfs_trans_handle *trans;
8615 struct btrfs_root *root = BTRFS_I(dir)->root;
8616 struct btrfs_path *path;
8617 struct btrfs_key key;
8618 struct inode *inode = NULL;
8619 int err;
8620 int drop_inode = 0;
8621 u64 objectid;
8622 u64 index = 0;
8623 int name_len;
8624 int datasize;
8625 unsigned long ptr;
8626 struct btrfs_file_extent_item *ei;
8627 struct extent_buffer *leaf;
8628
8629 name_len = strlen(symname);
8630 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
8631 return -ENAMETOOLONG;
8632
8633 /*
8634 * 2 items for inode item and ref
8635 * 2 items for dir items
8636 * 1 item for xattr if selinux is on
8637 */
8638 trans = btrfs_start_transaction(root, 5);
8639 if (IS_ERR(trans))
8640 return PTR_ERR(trans);
8641
8642 err = btrfs_find_free_ino(root, &objectid);
8643 if (err)
8644 goto out_unlock;
8645
8646 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
8647 dentry->d_name.len, btrfs_ino(dir), objectid,
8648 S_IFLNK|S_IRWXUGO, &index);
8649 if (IS_ERR(inode)) {
8650 err = PTR_ERR(inode);
8651 goto out_unlock;
8652 }
8653
8654 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
8655 if (err) {
8656 drop_inode = 1;
8657 goto out_unlock;
8658 }
8659
8660 /*
8661 * If the active LSM wants to access the inode during
8662 * d_instantiate it needs these. Smack checks to see
8663 * if the filesystem supports xattrs by looking at the
8664 * ops vector.
8665 */
8666 inode->i_fop = &btrfs_file_operations;
8667 inode->i_op = &btrfs_file_inode_operations;
8668
8669 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
8670 if (err)
8671 drop_inode = 1;
8672 else {
8673 inode->i_mapping->a_ops = &btrfs_aops;
8674 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
8675 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
8676 }
8677 if (drop_inode)
8678 goto out_unlock;
8679
8680 path = btrfs_alloc_path();
8681 if (!path) {
8682 err = -ENOMEM;
8683 drop_inode = 1;
8684 goto out_unlock;
8685 }
8686 key.objectid = btrfs_ino(inode);
8687 key.offset = 0;
8688 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
8689 datasize = btrfs_file_extent_calc_inline_size(name_len);
8690 err = btrfs_insert_empty_item(trans, root, path, &key,
8691 datasize);
8692 if (err) {
8693 drop_inode = 1;
8694 btrfs_free_path(path);
8695 goto out_unlock;
8696 }
8697 leaf = path->nodes[0];
8698 ei = btrfs_item_ptr(leaf, path->slots[0],
8699 struct btrfs_file_extent_item);
8700 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
8701 btrfs_set_file_extent_type(leaf, ei,
8702 BTRFS_FILE_EXTENT_INLINE);
8703 btrfs_set_file_extent_encryption(leaf, ei, 0);
8704 btrfs_set_file_extent_compression(leaf, ei, 0);
8705 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
8706 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
8707
8708 ptr = btrfs_file_extent_inline_start(ei);
8709 write_extent_buffer(leaf, symname, ptr, name_len);
8710 btrfs_mark_buffer_dirty(leaf);
8711 btrfs_free_path(path);
8712
8713 inode->i_op = &btrfs_symlink_inode_operations;
8714 inode->i_mapping->a_ops = &btrfs_symlink_aops;
8715 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
8716 inode_set_bytes(inode, name_len);
8717 btrfs_i_size_write(inode, name_len);
8718 err = btrfs_update_inode(trans, root, inode);
8719 if (err)
8720 drop_inode = 1;
8721
8722 out_unlock:
8723 if (!err)
8724 d_instantiate(dentry, inode);
8725 btrfs_end_transaction(trans, root);
8726 if (drop_inode) {
8727 inode_dec_link_count(inode);
8728 iput(inode);
8729 }
8730 btrfs_btree_balance_dirty(root);
8731 return err;
8732 }
8733
8734 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
8735 u64 start, u64 num_bytes, u64 min_size,
8736 loff_t actual_len, u64 *alloc_hint,
8737 struct btrfs_trans_handle *trans)
8738 {
8739 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
8740 struct extent_map *em;
8741 struct btrfs_root *root = BTRFS_I(inode)->root;
8742 struct btrfs_key ins;
8743 u64 cur_offset = start;
8744 u64 i_size;
8745 u64 cur_bytes;
8746 int ret = 0;
8747 bool own_trans = true;
8748
8749 if (trans)
8750 own_trans = false;
8751 while (num_bytes > 0) {
8752 if (own_trans) {
8753 trans = btrfs_start_transaction(root, 3);
8754 if (IS_ERR(trans)) {
8755 ret = PTR_ERR(trans);
8756 break;
8757 }
8758 }
8759
8760 cur_bytes = min(num_bytes, 256ULL * 1024 * 1024);
8761 cur_bytes = max(cur_bytes, min_size);
8762 ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0,
8763 *alloc_hint, &ins, 1);
8764 if (ret) {
8765 if (own_trans)
8766 btrfs_end_transaction(trans, root);
8767 break;
8768 }
8769
8770 ret = insert_reserved_file_extent(trans, inode,
8771 cur_offset, ins.objectid,
8772 ins.offset, ins.offset,
8773 ins.offset, 0, 0, 0,
8774 BTRFS_FILE_EXTENT_PREALLOC);
8775 if (ret) {
8776 btrfs_free_reserved_extent(root, ins.objectid,
8777 ins.offset);
8778 btrfs_abort_transaction(trans, root, ret);
8779 if (own_trans)
8780 btrfs_end_transaction(trans, root);
8781 break;
8782 }
8783 btrfs_drop_extent_cache(inode, cur_offset,
8784 cur_offset + ins.offset -1, 0);
8785
8786 em = alloc_extent_map();
8787 if (!em) {
8788 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
8789 &BTRFS_I(inode)->runtime_flags);
8790 goto next;
8791 }
8792
8793 em->start = cur_offset;
8794 em->orig_start = cur_offset;
8795 em->len = ins.offset;
8796 em->block_start = ins.objectid;
8797 em->block_len = ins.offset;
8798 em->orig_block_len = ins.offset;
8799 em->ram_bytes = ins.offset;
8800 em->bdev = root->fs_info->fs_devices->latest_bdev;
8801 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
8802 em->generation = trans->transid;
8803
8804 while (1) {
8805 write_lock(&em_tree->lock);
8806 ret = add_extent_mapping(em_tree, em, 1);
8807 write_unlock(&em_tree->lock);
8808 if (ret != -EEXIST)
8809 break;
8810 btrfs_drop_extent_cache(inode, cur_offset,
8811 cur_offset + ins.offset - 1,
8812 0);
8813 }
8814 free_extent_map(em);
8815 next:
8816 num_bytes -= ins.offset;
8817 cur_offset += ins.offset;
8818 *alloc_hint = ins.objectid + ins.offset;
8819
8820 inode_inc_iversion(inode);
8821 inode->i_ctime = CURRENT_TIME;
8822 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
8823 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
8824 (actual_len > inode->i_size) &&
8825 (cur_offset > inode->i_size)) {
8826 if (cur_offset > actual_len)
8827 i_size = actual_len;
8828 else
8829 i_size = cur_offset;
8830 i_size_write(inode, i_size);
8831 btrfs_ordered_update_i_size(inode, i_size, NULL);
8832 }
8833
8834 ret = btrfs_update_inode(trans, root, inode);
8835
8836 if (ret) {
8837 btrfs_abort_transaction(trans, root, ret);
8838 if (own_trans)
8839 btrfs_end_transaction(trans, root);
8840 break;
8841 }
8842
8843 if (own_trans)
8844 btrfs_end_transaction(trans, root);
8845 }
8846 return ret;
8847 }
8848
8849 int btrfs_prealloc_file_range(struct inode *inode, int mode,
8850 u64 start, u64 num_bytes, u64 min_size,
8851 loff_t actual_len, u64 *alloc_hint)
8852 {
8853 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
8854 min_size, actual_len, alloc_hint,
8855 NULL);
8856 }
8857
8858 int btrfs_prealloc_file_range_trans(struct inode *inode,
8859 struct btrfs_trans_handle *trans, int mode,
8860 u64 start, u64 num_bytes, u64 min_size,
8861 loff_t actual_len, u64 *alloc_hint)
8862 {
8863 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
8864 min_size, actual_len, alloc_hint, trans);
8865 }
8866
8867 static int btrfs_set_page_dirty(struct page *page)
8868 {
8869 return __set_page_dirty_nobuffers(page);
8870 }
8871
8872 static int btrfs_permission(struct inode *inode, int mask)
8873 {
8874 struct btrfs_root *root = BTRFS_I(inode)->root;
8875 umode_t mode = inode->i_mode;
8876
8877 if (mask & MAY_WRITE &&
8878 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
8879 if (btrfs_root_readonly(root))
8880 return -EROFS;
8881 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
8882 return -EACCES;
8883 }
8884 return generic_permission(inode, mask);
8885 }
8886
8887 static const struct inode_operations btrfs_dir_inode_operations = {
8888 .getattr = btrfs_getattr,
8889 .lookup = btrfs_lookup,
8890 .create = btrfs_create,
8891 .unlink = btrfs_unlink,
8892 .link = btrfs_link,
8893 .mkdir = btrfs_mkdir,
8894 .rmdir = btrfs_rmdir,
8895 .rename = btrfs_rename,
8896 .symlink = btrfs_symlink,
8897 .setattr = btrfs_setattr,
8898 .mknod = btrfs_mknod,
8899 .setxattr = btrfs_setxattr,
8900 .getxattr = btrfs_getxattr,
8901 .listxattr = btrfs_listxattr,
8902 .removexattr = btrfs_removexattr,
8903 .permission = btrfs_permission,
8904 .get_acl = btrfs_get_acl,
8905 .set_acl = btrfs_set_acl,
8906 .update_time = btrfs_update_time,
8907 };
8908 static const struct inode_operations btrfs_dir_ro_inode_operations = {
8909 .lookup = btrfs_lookup,
8910 .permission = btrfs_permission,
8911 .get_acl = btrfs_get_acl,
8912 .set_acl = btrfs_set_acl,
8913 .update_time = btrfs_update_time,
8914 };
8915
8916 static const struct file_operations btrfs_dir_file_operations = {
8917 .llseek = generic_file_llseek,
8918 .read = generic_read_dir,
8919 .iterate = btrfs_real_readdir,
8920 .unlocked_ioctl = btrfs_ioctl,
8921 #ifdef CONFIG_COMPAT
8922 .compat_ioctl = btrfs_ioctl,
8923 #endif
8924 .release = btrfs_release_file,
8925 .fsync = btrfs_sync_file,
8926 };
8927
8928 static struct extent_io_ops btrfs_extent_io_ops = {
8929 .fill_delalloc = run_delalloc_range,
8930 .submit_bio_hook = btrfs_submit_bio_hook,
8931 .merge_bio_hook = btrfs_merge_bio_hook,
8932 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
8933 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
8934 .writepage_start_hook = btrfs_writepage_start_hook,
8935 .set_bit_hook = btrfs_set_bit_hook,
8936 .clear_bit_hook = btrfs_clear_bit_hook,
8937 .merge_extent_hook = btrfs_merge_extent_hook,
8938 .split_extent_hook = btrfs_split_extent_hook,
8939 };
8940
8941 /*
8942 * btrfs doesn't support the bmap operation because swapfiles
8943 * use bmap to make a mapping of extents in the file. They assume
8944 * these extents won't change over the life of the file and they
8945 * use the bmap result to do IO directly to the drive.
8946 *
8947 * the btrfs bmap call would return logical addresses that aren't
8948 * suitable for IO and they also will change frequently as COW
8949 * operations happen. So, swapfile + btrfs == corruption.
8950 *
8951 * For now we're avoiding this by dropping bmap.
8952 */
8953 static const struct address_space_operations btrfs_aops = {
8954 .readpage = btrfs_readpage,
8955 .writepage = btrfs_writepage,
8956 .writepages = btrfs_writepages,
8957 .readpages = btrfs_readpages,
8958 .direct_IO = btrfs_direct_IO,
8959 .invalidatepage = btrfs_invalidatepage,
8960 .releasepage = btrfs_releasepage,
8961 .set_page_dirty = btrfs_set_page_dirty,
8962 .error_remove_page = generic_error_remove_page,
8963 };
8964
8965 static const struct address_space_operations btrfs_symlink_aops = {
8966 .readpage = btrfs_readpage,
8967 .writepage = btrfs_writepage,
8968 .invalidatepage = btrfs_invalidatepage,
8969 .releasepage = btrfs_releasepage,
8970 };
8971
8972 static const struct inode_operations btrfs_file_inode_operations = {
8973 .getattr = btrfs_getattr,
8974 .setattr = btrfs_setattr,
8975 .setxattr = btrfs_setxattr,
8976 .getxattr = btrfs_getxattr,
8977 .listxattr = btrfs_listxattr,
8978 .removexattr = btrfs_removexattr,
8979 .permission = btrfs_permission,
8980 .fiemap = btrfs_fiemap,
8981 .get_acl = btrfs_get_acl,
8982 .set_acl = btrfs_set_acl,
8983 .update_time = btrfs_update_time,
8984 };
8985 static const struct inode_operations btrfs_special_inode_operations = {
8986 .getattr = btrfs_getattr,
8987 .setattr = btrfs_setattr,
8988 .permission = btrfs_permission,
8989 .setxattr = btrfs_setxattr,
8990 .getxattr = btrfs_getxattr,
8991 .listxattr = btrfs_listxattr,
8992 .removexattr = btrfs_removexattr,
8993 .get_acl = btrfs_get_acl,
8994 .set_acl = btrfs_set_acl,
8995 .update_time = btrfs_update_time,
8996 };
8997 static const struct inode_operations btrfs_symlink_inode_operations = {
8998 .readlink = generic_readlink,
8999 .follow_link = page_follow_link_light,
9000 .put_link = page_put_link,
9001 .getattr = btrfs_getattr,
9002 .setattr = btrfs_setattr,
9003 .permission = btrfs_permission,
9004 .setxattr = btrfs_setxattr,
9005 .getxattr = btrfs_getxattr,
9006 .listxattr = btrfs_listxattr,
9007 .removexattr = btrfs_removexattr,
9008 .update_time = btrfs_update_time,
9009 };
9010
9011 const struct dentry_operations btrfs_dentry_operations = {
9012 .d_delete = btrfs_dentry_delete,
9013 .d_release = btrfs_dentry_release,
9014 };
Linux kernel - Deliverables
This page took 0.202264 seconds and 4 git commands to generate.