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1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/pagemap.h>
25 #include <linux/highmem.h>
26 #include <linux/time.h>
27 #include <linux/init.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mpage.h>
31 #include <linux/swap.h>
32 #include <linux/writeback.h>
33 #include <linux/statfs.h>
34 #include <linux/compat.h>
35 #include <linux/bit_spinlock.h>
36 #include <linux/xattr.h>
37 #include <linux/posix_acl.h>
38 #include <linux/falloc.h>
39 #include <linux/slab.h>
40 #include <linux/ratelimit.h>
41 #include <linux/mount.h>
42 #include <linux/btrfs.h>
43 #include <linux/blkdev.h>
44 #include "compat.h"
45 #include "ctree.h"
46 #include "disk-io.h"
47 #include "transaction.h"
48 #include "btrfs_inode.h"
49 #include "print-tree.h"
50 #include "ordered-data.h"
51 #include "xattr.h"
52 #include "tree-log.h"
53 #include "volumes.h"
54 #include "compression.h"
55 #include "locking.h"
56 #include "free-space-cache.h"
57 #include "inode-map.h"
58 #include "backref.h"
59
60 struct btrfs_iget_args {
61 u64 ino;
62 struct btrfs_root *root;
63 };
64
65 static const struct inode_operations btrfs_dir_inode_operations;
66 static const struct inode_operations btrfs_symlink_inode_operations;
67 static const struct inode_operations btrfs_dir_ro_inode_operations;
68 static const struct inode_operations btrfs_special_inode_operations;
69 static const struct inode_operations btrfs_file_inode_operations;
70 static const struct address_space_operations btrfs_aops;
71 static const struct address_space_operations btrfs_symlink_aops;
72 static const struct file_operations btrfs_dir_file_operations;
73 static struct extent_io_ops btrfs_extent_io_ops;
74
75 static struct kmem_cache *btrfs_inode_cachep;
76 static struct kmem_cache *btrfs_delalloc_work_cachep;
77 struct kmem_cache *btrfs_trans_handle_cachep;
78 struct kmem_cache *btrfs_transaction_cachep;
79 struct kmem_cache *btrfs_path_cachep;
80 struct kmem_cache *btrfs_free_space_cachep;
81
82 #define S_SHIFT 12
83 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
84 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
85 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
86 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
87 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
88 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
89 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
90 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
91 };
92
93 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
94 static int btrfs_truncate(struct inode *inode);
95 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
96 static noinline int cow_file_range(struct inode *inode,
97 struct page *locked_page,
98 u64 start, u64 end, int *page_started,
99 unsigned long *nr_written, int unlock);
100 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
101 u64 len, u64 orig_start,
102 u64 block_start, u64 block_len,
103 u64 orig_block_len, u64 ram_bytes,
104 int type);
105
106 static int btrfs_dirty_inode(struct inode *inode);
107
108 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
109 struct inode *inode, struct inode *dir,
110 const struct qstr *qstr)
111 {
112 int err;
113
114 err = btrfs_init_acl(trans, inode, dir);
115 if (!err)
116 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
117 return err;
118 }
119
120 /*
121 * this does all the hard work for inserting an inline extent into
122 * the btree. The caller should have done a btrfs_drop_extents so that
123 * no overlapping inline items exist in the btree
124 */
125 static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
126 struct btrfs_root *root, struct inode *inode,
127 u64 start, size_t size, size_t compressed_size,
128 int compress_type,
129 struct page **compressed_pages)
130 {
131 struct btrfs_key key;
132 struct btrfs_path *path;
133 struct extent_buffer *leaf;
134 struct page *page = NULL;
135 char *kaddr;
136 unsigned long ptr;
137 struct btrfs_file_extent_item *ei;
138 int err = 0;
139 int ret;
140 size_t cur_size = size;
141 size_t datasize;
142 unsigned long offset;
143
144 if (compressed_size && compressed_pages)
145 cur_size = compressed_size;
146
147 path = btrfs_alloc_path();
148 if (!path)
149 return -ENOMEM;
150
151 path->leave_spinning = 1;
152
153 key.objectid = btrfs_ino(inode);
154 key.offset = start;
155 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
156 datasize = btrfs_file_extent_calc_inline_size(cur_size);
157
158 inode_add_bytes(inode, size);
159 ret = btrfs_insert_empty_item(trans, root, path, &key,
160 datasize);
161 if (ret) {
162 err = ret;
163 goto fail;
164 }
165 leaf = path->nodes[0];
166 ei = btrfs_item_ptr(leaf, path->slots[0],
167 struct btrfs_file_extent_item);
168 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
169 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
170 btrfs_set_file_extent_encryption(leaf, ei, 0);
171 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
172 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
173 ptr = btrfs_file_extent_inline_start(ei);
174
175 if (compress_type != BTRFS_COMPRESS_NONE) {
176 struct page *cpage;
177 int i = 0;
178 while (compressed_size > 0) {
179 cpage = compressed_pages[i];
180 cur_size = min_t(unsigned long, compressed_size,
181 PAGE_CACHE_SIZE);
182
183 kaddr = kmap_atomic(cpage);
184 write_extent_buffer(leaf, kaddr, ptr, cur_size);
185 kunmap_atomic(kaddr);
186
187 i++;
188 ptr += cur_size;
189 compressed_size -= cur_size;
190 }
191 btrfs_set_file_extent_compression(leaf, ei,
192 compress_type);
193 } else {
194 page = find_get_page(inode->i_mapping,
195 start >> PAGE_CACHE_SHIFT);
196 btrfs_set_file_extent_compression(leaf, ei, 0);
197 kaddr = kmap_atomic(page);
198 offset = start & (PAGE_CACHE_SIZE - 1);
199 write_extent_buffer(leaf, kaddr + offset, ptr, size);
200 kunmap_atomic(kaddr);
201 page_cache_release(page);
202 }
203 btrfs_mark_buffer_dirty(leaf);
204 btrfs_free_path(path);
205
206 /*
207 * we're an inline extent, so nobody can
208 * extend the file past i_size without locking
209 * a page we already have locked.
210 *
211 * We must do any isize and inode updates
212 * before we unlock the pages. Otherwise we
213 * could end up racing with unlink.
214 */
215 BTRFS_I(inode)->disk_i_size = inode->i_size;
216 ret = btrfs_update_inode(trans, root, inode);
217
218 return ret;
219 fail:
220 btrfs_free_path(path);
221 return err;
222 }
223
224
225 /*
226 * conditionally insert an inline extent into the file. This
227 * does the checks required to make sure the data is small enough
228 * to fit as an inline extent.
229 */
230 static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans,
231 struct btrfs_root *root,
232 struct inode *inode, u64 start, u64 end,
233 size_t compressed_size, int compress_type,
234 struct page **compressed_pages)
235 {
236 u64 isize = i_size_read(inode);
237 u64 actual_end = min(end + 1, isize);
238 u64 inline_len = actual_end - start;
239 u64 aligned_end = ALIGN(end, root->sectorsize);
240 u64 data_len = inline_len;
241 int ret;
242
243 if (compressed_size)
244 data_len = compressed_size;
245
246 if (start > 0 ||
247 actual_end >= PAGE_CACHE_SIZE ||
248 data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
249 (!compressed_size &&
250 (actual_end & (root->sectorsize - 1)) == 0) ||
251 end + 1 < isize ||
252 data_len > root->fs_info->max_inline) {
253 return 1;
254 }
255
256 ret = btrfs_drop_extents(trans, root, inode, start, aligned_end, 1);
257 if (ret)
258 return ret;
259
260 if (isize > actual_end)
261 inline_len = min_t(u64, isize, actual_end);
262 ret = insert_inline_extent(trans, root, inode, start,
263 inline_len, compressed_size,
264 compress_type, compressed_pages);
265 if (ret && ret != -ENOSPC) {
266 btrfs_abort_transaction(trans, root, ret);
267 return ret;
268 } else if (ret == -ENOSPC) {
269 return 1;
270 }
271
272 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
273 btrfs_delalloc_release_metadata(inode, end + 1 - start);
274 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
275 return 0;
276 }
277
278 struct async_extent {
279 u64 start;
280 u64 ram_size;
281 u64 compressed_size;
282 struct page **pages;
283 unsigned long nr_pages;
284 int compress_type;
285 struct list_head list;
286 };
287
288 struct async_cow {
289 struct inode *inode;
290 struct btrfs_root *root;
291 struct page *locked_page;
292 u64 start;
293 u64 end;
294 struct list_head extents;
295 struct btrfs_work work;
296 };
297
298 static noinline int add_async_extent(struct async_cow *cow,
299 u64 start, u64 ram_size,
300 u64 compressed_size,
301 struct page **pages,
302 unsigned long nr_pages,
303 int compress_type)
304 {
305 struct async_extent *async_extent;
306
307 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
308 BUG_ON(!async_extent); /* -ENOMEM */
309 async_extent->start = start;
310 async_extent->ram_size = ram_size;
311 async_extent->compressed_size = compressed_size;
312 async_extent->pages = pages;
313 async_extent->nr_pages = nr_pages;
314 async_extent->compress_type = compress_type;
315 list_add_tail(&async_extent->list, &cow->extents);
316 return 0;
317 }
318
319 /*
320 * we create compressed extents in two phases. The first
321 * phase compresses a range of pages that have already been
322 * locked (both pages and state bits are locked).
323 *
324 * This is done inside an ordered work queue, and the compression
325 * is spread across many cpus. The actual IO submission is step
326 * two, and the ordered work queue takes care of making sure that
327 * happens in the same order things were put onto the queue by
328 * writepages and friends.
329 *
330 * If this code finds it can't get good compression, it puts an
331 * entry onto the work queue to write the uncompressed bytes. This
332 * makes sure that both compressed inodes and uncompressed inodes
333 * are written in the same order that the flusher thread sent them
334 * down.
335 */
336 static noinline int compress_file_range(struct inode *inode,
337 struct page *locked_page,
338 u64 start, u64 end,
339 struct async_cow *async_cow,
340 int *num_added)
341 {
342 struct btrfs_root *root = BTRFS_I(inode)->root;
343 struct btrfs_trans_handle *trans;
344 u64 num_bytes;
345 u64 blocksize = root->sectorsize;
346 u64 actual_end;
347 u64 isize = i_size_read(inode);
348 int ret = 0;
349 struct page **pages = NULL;
350 unsigned long nr_pages;
351 unsigned long nr_pages_ret = 0;
352 unsigned long total_compressed = 0;
353 unsigned long total_in = 0;
354 unsigned long max_compressed = 128 * 1024;
355 unsigned long max_uncompressed = 128 * 1024;
356 int i;
357 int will_compress;
358 int compress_type = root->fs_info->compress_type;
359 int redirty = 0;
360
361 /* if this is a small write inside eof, kick off a defrag */
362 if ((end - start + 1) < 16 * 1024 &&
363 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
364 btrfs_add_inode_defrag(NULL, inode);
365
366 actual_end = min_t(u64, isize, end + 1);
367 again:
368 will_compress = 0;
369 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
370 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
371
372 /*
373 * we don't want to send crud past the end of i_size through
374 * compression, that's just a waste of CPU time. So, if the
375 * end of the file is before the start of our current
376 * requested range of bytes, we bail out to the uncompressed
377 * cleanup code that can deal with all of this.
378 *
379 * It isn't really the fastest way to fix things, but this is a
380 * very uncommon corner.
381 */
382 if (actual_end <= start)
383 goto cleanup_and_bail_uncompressed;
384
385 total_compressed = actual_end - start;
386
387 /* we want to make sure that amount of ram required to uncompress
388 * an extent is reasonable, so we limit the total size in ram
389 * of a compressed extent to 128k. This is a crucial number
390 * because it also controls how easily we can spread reads across
391 * cpus for decompression.
392 *
393 * We also want to make sure the amount of IO required to do
394 * a random read is reasonably small, so we limit the size of
395 * a compressed extent to 128k.
396 */
397 total_compressed = min(total_compressed, max_uncompressed);
398 num_bytes = ALIGN(end - start + 1, blocksize);
399 num_bytes = max(blocksize, num_bytes);
400 total_in = 0;
401 ret = 0;
402
403 /*
404 * we do compression for mount -o compress and when the
405 * inode has not been flagged as nocompress. This flag can
406 * change at any time if we discover bad compression ratios.
407 */
408 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) &&
409 (btrfs_test_opt(root, COMPRESS) ||
410 (BTRFS_I(inode)->force_compress) ||
411 (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) {
412 WARN_ON(pages);
413 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
414 if (!pages) {
415 /* just bail out to the uncompressed code */
416 goto cont;
417 }
418
419 if (BTRFS_I(inode)->force_compress)
420 compress_type = BTRFS_I(inode)->force_compress;
421
422 /*
423 * we need to call clear_page_dirty_for_io on each
424 * page in the range. Otherwise applications with the file
425 * mmap'd can wander in and change the page contents while
426 * we are compressing them.
427 *
428 * If the compression fails for any reason, we set the pages
429 * dirty again later on.
430 */
431 extent_range_clear_dirty_for_io(inode, start, end);
432 redirty = 1;
433 ret = btrfs_compress_pages(compress_type,
434 inode->i_mapping, start,
435 total_compressed, pages,
436 nr_pages, &nr_pages_ret,
437 &total_in,
438 &total_compressed,
439 max_compressed);
440
441 if (!ret) {
442 unsigned long offset = total_compressed &
443 (PAGE_CACHE_SIZE - 1);
444 struct page *page = pages[nr_pages_ret - 1];
445 char *kaddr;
446
447 /* zero the tail end of the last page, we might be
448 * sending it down to disk
449 */
450 if (offset) {
451 kaddr = kmap_atomic(page);
452 memset(kaddr + offset, 0,
453 PAGE_CACHE_SIZE - offset);
454 kunmap_atomic(kaddr);
455 }
456 will_compress = 1;
457 }
458 }
459 cont:
460 if (start == 0) {
461 trans = btrfs_join_transaction(root);
462 if (IS_ERR(trans)) {
463 ret = PTR_ERR(trans);
464 trans = NULL;
465 goto cleanup_and_out;
466 }
467 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
468
469 /* lets try to make an inline extent */
470 if (ret || total_in < (actual_end - start)) {
471 /* we didn't compress the entire range, try
472 * to make an uncompressed inline extent.
473 */
474 ret = cow_file_range_inline(trans, root, inode,
475 start, end, 0, 0, NULL);
476 } else {
477 /* try making a compressed inline extent */
478 ret = cow_file_range_inline(trans, root, inode,
479 start, end,
480 total_compressed,
481 compress_type, pages);
482 }
483 if (ret <= 0) {
484 /*
485 * inline extent creation worked or returned error,
486 * we don't need to create any more async work items.
487 * Unlock and free up our temp pages.
488 */
489 extent_clear_unlock_delalloc(inode,
490 &BTRFS_I(inode)->io_tree,
491 start, end, NULL,
492 EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
493 EXTENT_CLEAR_DELALLOC |
494 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK);
495
496 btrfs_end_transaction(trans, root);
497 goto free_pages_out;
498 }
499 btrfs_end_transaction(trans, root);
500 }
501
502 if (will_compress) {
503 /*
504 * we aren't doing an inline extent round the compressed size
505 * up to a block size boundary so the allocator does sane
506 * things
507 */
508 total_compressed = ALIGN(total_compressed, blocksize);
509
510 /*
511 * one last check to make sure the compression is really a
512 * win, compare the page count read with the blocks on disk
513 */
514 total_in = ALIGN(total_in, PAGE_CACHE_SIZE);
515 if (total_compressed >= total_in) {
516 will_compress = 0;
517 } else {
518 num_bytes = total_in;
519 }
520 }
521 if (!will_compress && pages) {
522 /*
523 * the compression code ran but failed to make things smaller,
524 * free any pages it allocated and our page pointer array
525 */
526 for (i = 0; i < nr_pages_ret; i++) {
527 WARN_ON(pages[i]->mapping);
528 page_cache_release(pages[i]);
529 }
530 kfree(pages);
531 pages = NULL;
532 total_compressed = 0;
533 nr_pages_ret = 0;
534
535 /* flag the file so we don't compress in the future */
536 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
537 !(BTRFS_I(inode)->force_compress)) {
538 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
539 }
540 }
541 if (will_compress) {
542 *num_added += 1;
543
544 /* the async work queues will take care of doing actual
545 * allocation on disk for these compressed pages,
546 * and will submit them to the elevator.
547 */
548 add_async_extent(async_cow, start, num_bytes,
549 total_compressed, pages, nr_pages_ret,
550 compress_type);
551
552 if (start + num_bytes < end) {
553 start += num_bytes;
554 pages = NULL;
555 cond_resched();
556 goto again;
557 }
558 } else {
559 cleanup_and_bail_uncompressed:
560 /*
561 * No compression, but we still need to write the pages in
562 * the file we've been given so far. redirty the locked
563 * page if it corresponds to our extent and set things up
564 * for the async work queue to run cow_file_range to do
565 * the normal delalloc dance
566 */
567 if (page_offset(locked_page) >= start &&
568 page_offset(locked_page) <= end) {
569 __set_page_dirty_nobuffers(locked_page);
570 /* unlocked later on in the async handlers */
571 }
572 if (redirty)
573 extent_range_redirty_for_io(inode, start, end);
574 add_async_extent(async_cow, start, end - start + 1,
575 0, NULL, 0, BTRFS_COMPRESS_NONE);
576 *num_added += 1;
577 }
578
579 out:
580 return ret;
581
582 free_pages_out:
583 for (i = 0; i < nr_pages_ret; i++) {
584 WARN_ON(pages[i]->mapping);
585 page_cache_release(pages[i]);
586 }
587 kfree(pages);
588
589 goto out;
590
591 cleanup_and_out:
592 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
593 start, end, NULL,
594 EXTENT_CLEAR_UNLOCK_PAGE |
595 EXTENT_CLEAR_DIRTY |
596 EXTENT_CLEAR_DELALLOC |
597 EXTENT_SET_WRITEBACK |
598 EXTENT_END_WRITEBACK);
599 if (!trans || IS_ERR(trans))
600 btrfs_error(root->fs_info, ret, "Failed to join transaction");
601 else
602 btrfs_abort_transaction(trans, root, ret);
603 goto free_pages_out;
604 }
605
606 /*
607 * phase two of compressed writeback. This is the ordered portion
608 * of the code, which only gets called in the order the work was
609 * queued. We walk all the async extents created by compress_file_range
610 * and send them down to the disk.
611 */
612 static noinline int submit_compressed_extents(struct inode *inode,
613 struct async_cow *async_cow)
614 {
615 struct async_extent *async_extent;
616 u64 alloc_hint = 0;
617 struct btrfs_trans_handle *trans;
618 struct btrfs_key ins;
619 struct extent_map *em;
620 struct btrfs_root *root = BTRFS_I(inode)->root;
621 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
622 struct extent_io_tree *io_tree;
623 int ret = 0;
624
625 if (list_empty(&async_cow->extents))
626 return 0;
627
628 again:
629 while (!list_empty(&async_cow->extents)) {
630 async_extent = list_entry(async_cow->extents.next,
631 struct async_extent, list);
632 list_del(&async_extent->list);
633
634 io_tree = &BTRFS_I(inode)->io_tree;
635
636 retry:
637 /* did the compression code fall back to uncompressed IO? */
638 if (!async_extent->pages) {
639 int page_started = 0;
640 unsigned long nr_written = 0;
641
642 lock_extent(io_tree, async_extent->start,
643 async_extent->start +
644 async_extent->ram_size - 1);
645
646 /* allocate blocks */
647 ret = cow_file_range(inode, async_cow->locked_page,
648 async_extent->start,
649 async_extent->start +
650 async_extent->ram_size - 1,
651 &page_started, &nr_written, 0);
652
653 /* JDM XXX */
654
655 /*
656 * if page_started, cow_file_range inserted an
657 * inline extent and took care of all the unlocking
658 * and IO for us. Otherwise, we need to submit
659 * all those pages down to the drive.
660 */
661 if (!page_started && !ret)
662 extent_write_locked_range(io_tree,
663 inode, async_extent->start,
664 async_extent->start +
665 async_extent->ram_size - 1,
666 btrfs_get_extent,
667 WB_SYNC_ALL);
668 else if (ret)
669 unlock_page(async_cow->locked_page);
670 kfree(async_extent);
671 cond_resched();
672 continue;
673 }
674
675 lock_extent(io_tree, async_extent->start,
676 async_extent->start + async_extent->ram_size - 1);
677
678 trans = btrfs_join_transaction(root);
679 if (IS_ERR(trans)) {
680 ret = PTR_ERR(trans);
681 } else {
682 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
683 ret = btrfs_reserve_extent(trans, root,
684 async_extent->compressed_size,
685 async_extent->compressed_size,
686 0, alloc_hint, &ins, 1);
687 if (ret && ret != -ENOSPC)
688 btrfs_abort_transaction(trans, root, ret);
689 btrfs_end_transaction(trans, root);
690 }
691
692 if (ret) {
693 int i;
694
695 for (i = 0; i < async_extent->nr_pages; i++) {
696 WARN_ON(async_extent->pages[i]->mapping);
697 page_cache_release(async_extent->pages[i]);
698 }
699 kfree(async_extent->pages);
700 async_extent->nr_pages = 0;
701 async_extent->pages = NULL;
702
703 if (ret == -ENOSPC)
704 goto retry;
705 goto out_free;
706 }
707
708 /*
709 * here we're doing allocation and writeback of the
710 * compressed pages
711 */
712 btrfs_drop_extent_cache(inode, async_extent->start,
713 async_extent->start +
714 async_extent->ram_size - 1, 0);
715
716 em = alloc_extent_map();
717 if (!em) {
718 ret = -ENOMEM;
719 goto out_free_reserve;
720 }
721 em->start = async_extent->start;
722 em->len = async_extent->ram_size;
723 em->orig_start = em->start;
724 em->mod_start = em->start;
725 em->mod_len = em->len;
726
727 em->block_start = ins.objectid;
728 em->block_len = ins.offset;
729 em->orig_block_len = ins.offset;
730 em->ram_bytes = async_extent->ram_size;
731 em->bdev = root->fs_info->fs_devices->latest_bdev;
732 em->compress_type = async_extent->compress_type;
733 set_bit(EXTENT_FLAG_PINNED, &em->flags);
734 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
735 em->generation = -1;
736
737 while (1) {
738 write_lock(&em_tree->lock);
739 ret = add_extent_mapping(em_tree, em, 1);
740 write_unlock(&em_tree->lock);
741 if (ret != -EEXIST) {
742 free_extent_map(em);
743 break;
744 }
745 btrfs_drop_extent_cache(inode, async_extent->start,
746 async_extent->start +
747 async_extent->ram_size - 1, 0);
748 }
749
750 if (ret)
751 goto out_free_reserve;
752
753 ret = btrfs_add_ordered_extent_compress(inode,
754 async_extent->start,
755 ins.objectid,
756 async_extent->ram_size,
757 ins.offset,
758 BTRFS_ORDERED_COMPRESSED,
759 async_extent->compress_type);
760 if (ret)
761 goto out_free_reserve;
762
763 /*
764 * clear dirty, set writeback and unlock the pages.
765 */
766 extent_clear_unlock_delalloc(inode,
767 &BTRFS_I(inode)->io_tree,
768 async_extent->start,
769 async_extent->start +
770 async_extent->ram_size - 1,
771 NULL, EXTENT_CLEAR_UNLOCK_PAGE |
772 EXTENT_CLEAR_UNLOCK |
773 EXTENT_CLEAR_DELALLOC |
774 EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK);
775
776 ret = btrfs_submit_compressed_write(inode,
777 async_extent->start,
778 async_extent->ram_size,
779 ins.objectid,
780 ins.offset, async_extent->pages,
781 async_extent->nr_pages);
782 alloc_hint = ins.objectid + ins.offset;
783 kfree(async_extent);
784 if (ret)
785 goto out;
786 cond_resched();
787 }
788 ret = 0;
789 out:
790 return ret;
791 out_free_reserve:
792 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
793 out_free:
794 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
795 async_extent->start,
796 async_extent->start +
797 async_extent->ram_size - 1,
798 NULL, EXTENT_CLEAR_UNLOCK_PAGE |
799 EXTENT_CLEAR_UNLOCK |
800 EXTENT_CLEAR_DELALLOC |
801 EXTENT_CLEAR_DIRTY |
802 EXTENT_SET_WRITEBACK |
803 EXTENT_END_WRITEBACK);
804 kfree(async_extent);
805 goto again;
806 }
807
808 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
809 u64 num_bytes)
810 {
811 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
812 struct extent_map *em;
813 u64 alloc_hint = 0;
814
815 read_lock(&em_tree->lock);
816 em = search_extent_mapping(em_tree, start, num_bytes);
817 if (em) {
818 /*
819 * if block start isn't an actual block number then find the
820 * first block in this inode and use that as a hint. If that
821 * block is also bogus then just don't worry about it.
822 */
823 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
824 free_extent_map(em);
825 em = search_extent_mapping(em_tree, 0, 0);
826 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
827 alloc_hint = em->block_start;
828 if (em)
829 free_extent_map(em);
830 } else {
831 alloc_hint = em->block_start;
832 free_extent_map(em);
833 }
834 }
835 read_unlock(&em_tree->lock);
836
837 return alloc_hint;
838 }
839
840 /*
841 * when extent_io.c finds a delayed allocation range in the file,
842 * the call backs end up in this code. The basic idea is to
843 * allocate extents on disk for the range, and create ordered data structs
844 * in ram to track those extents.
845 *
846 * locked_page is the page that writepage had locked already. We use
847 * it to make sure we don't do extra locks or unlocks.
848 *
849 * *page_started is set to one if we unlock locked_page and do everything
850 * required to start IO on it. It may be clean and already done with
851 * IO when we return.
852 */
853 static noinline int __cow_file_range(struct btrfs_trans_handle *trans,
854 struct inode *inode,
855 struct btrfs_root *root,
856 struct page *locked_page,
857 u64 start, u64 end, int *page_started,
858 unsigned long *nr_written,
859 int unlock)
860 {
861 u64 alloc_hint = 0;
862 u64 num_bytes;
863 unsigned long ram_size;
864 u64 disk_num_bytes;
865 u64 cur_alloc_size;
866 u64 blocksize = root->sectorsize;
867 struct btrfs_key ins;
868 struct extent_map *em;
869 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
870 int ret = 0;
871
872 BUG_ON(btrfs_is_free_space_inode(inode));
873
874 num_bytes = ALIGN(end - start + 1, blocksize);
875 num_bytes = max(blocksize, num_bytes);
876 disk_num_bytes = num_bytes;
877
878 /* if this is a small write inside eof, kick off defrag */
879 if (num_bytes < 64 * 1024 &&
880 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
881 btrfs_add_inode_defrag(trans, inode);
882
883 if (start == 0) {
884 /* lets try to make an inline extent */
885 ret = cow_file_range_inline(trans, root, inode,
886 start, end, 0, 0, NULL);
887 if (ret == 0) {
888 extent_clear_unlock_delalloc(inode,
889 &BTRFS_I(inode)->io_tree,
890 start, end, NULL,
891 EXTENT_CLEAR_UNLOCK_PAGE |
892 EXTENT_CLEAR_UNLOCK |
893 EXTENT_CLEAR_DELALLOC |
894 EXTENT_CLEAR_DIRTY |
895 EXTENT_SET_WRITEBACK |
896 EXTENT_END_WRITEBACK);
897
898 *nr_written = *nr_written +
899 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
900 *page_started = 1;
901 goto out;
902 } else if (ret < 0) {
903 btrfs_abort_transaction(trans, root, ret);
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(trans, root, cur_alloc_size,
919 root->sectorsize, 0, alloc_hint,
920 &ins, 1);
921 if (ret < 0) {
922 btrfs_abort_transaction(trans, root, ret);
923 goto out_unlock;
924 }
925
926 em = alloc_extent_map();
927 if (!em) {
928 ret = -ENOMEM;
929 goto out_reserve;
930 }
931 em->start = start;
932 em->orig_start = em->start;
933 ram_size = ins.offset;
934 em->len = ins.offset;
935 em->mod_start = em->start;
936 em->mod_len = em->len;
937
938 em->block_start = ins.objectid;
939 em->block_len = ins.offset;
940 em->orig_block_len = ins.offset;
941 em->ram_bytes = ram_size;
942 em->bdev = root->fs_info->fs_devices->latest_bdev;
943 set_bit(EXTENT_FLAG_PINNED, &em->flags);
944 em->generation = -1;
945
946 while (1) {
947 write_lock(&em_tree->lock);
948 ret = add_extent_mapping(em_tree, em, 1);
949 write_unlock(&em_tree->lock);
950 if (ret != -EEXIST) {
951 free_extent_map(em);
952 break;
953 }
954 btrfs_drop_extent_cache(inode, start,
955 start + ram_size - 1, 0);
956 }
957 if (ret)
958 goto out_reserve;
959
960 cur_alloc_size = ins.offset;
961 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
962 ram_size, cur_alloc_size, 0);
963 if (ret)
964 goto out_reserve;
965
966 if (root->root_key.objectid ==
967 BTRFS_DATA_RELOC_TREE_OBJECTID) {
968 ret = btrfs_reloc_clone_csums(inode, start,
969 cur_alloc_size);
970 if (ret) {
971 btrfs_abort_transaction(trans, root, ret);
972 goto out_reserve;
973 }
974 }
975
976 if (disk_num_bytes < cur_alloc_size)
977 break;
978
979 /* we're not doing compressed IO, don't unlock the first
980 * page (which the caller expects to stay locked), don't
981 * clear any dirty bits and don't set any writeback bits
982 *
983 * Do set the Private2 bit so we know this page was properly
984 * setup for writepage
985 */
986 op = unlock ? EXTENT_CLEAR_UNLOCK_PAGE : 0;
987 op |= EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
988 EXTENT_SET_PRIVATE2;
989
990 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
991 start, start + ram_size - 1,
992 locked_page, op);
993 disk_num_bytes -= cur_alloc_size;
994 num_bytes -= cur_alloc_size;
995 alloc_hint = ins.objectid + ins.offset;
996 start += cur_alloc_size;
997 }
998 out:
999 return ret;
1000
1001 out_reserve:
1002 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
1003 out_unlock:
1004 extent_clear_unlock_delalloc(inode,
1005 &BTRFS_I(inode)->io_tree,
1006 start, end, locked_page,
1007 EXTENT_CLEAR_UNLOCK_PAGE |
1008 EXTENT_CLEAR_UNLOCK |
1009 EXTENT_CLEAR_DELALLOC |
1010 EXTENT_CLEAR_DIRTY |
1011 EXTENT_SET_WRITEBACK |
1012 EXTENT_END_WRITEBACK);
1013
1014 goto out;
1015 }
1016
1017 static noinline int cow_file_range(struct inode *inode,
1018 struct page *locked_page,
1019 u64 start, u64 end, int *page_started,
1020 unsigned long *nr_written,
1021 int unlock)
1022 {
1023 struct btrfs_trans_handle *trans;
1024 struct btrfs_root *root = BTRFS_I(inode)->root;
1025 int ret;
1026
1027 trans = btrfs_join_transaction(root);
1028 if (IS_ERR(trans)) {
1029 extent_clear_unlock_delalloc(inode,
1030 &BTRFS_I(inode)->io_tree,
1031 start, end, locked_page,
1032 EXTENT_CLEAR_UNLOCK_PAGE |
1033 EXTENT_CLEAR_UNLOCK |
1034 EXTENT_CLEAR_DELALLOC |
1035 EXTENT_CLEAR_DIRTY |
1036 EXTENT_SET_WRITEBACK |
1037 EXTENT_END_WRITEBACK);
1038 return PTR_ERR(trans);
1039 }
1040 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1041
1042 ret = __cow_file_range(trans, inode, root, locked_page, start, end,
1043 page_started, nr_written, unlock);
1044
1045 btrfs_end_transaction(trans, root);
1046
1047 return ret;
1048 }
1049
1050 /*
1051 * work queue call back to started compression on a file and pages
1052 */
1053 static noinline void async_cow_start(struct btrfs_work *work)
1054 {
1055 struct async_cow *async_cow;
1056 int num_added = 0;
1057 async_cow = container_of(work, struct async_cow, work);
1058
1059 compress_file_range(async_cow->inode, async_cow->locked_page,
1060 async_cow->start, async_cow->end, async_cow,
1061 &num_added);
1062 if (num_added == 0) {
1063 btrfs_add_delayed_iput(async_cow->inode);
1064 async_cow->inode = NULL;
1065 }
1066 }
1067
1068 /*
1069 * work queue call back to submit previously compressed pages
1070 */
1071 static noinline void async_cow_submit(struct btrfs_work *work)
1072 {
1073 struct async_cow *async_cow;
1074 struct btrfs_root *root;
1075 unsigned long nr_pages;
1076
1077 async_cow = container_of(work, struct async_cow, work);
1078
1079 root = async_cow->root;
1080 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
1081 PAGE_CACHE_SHIFT;
1082
1083 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1084 5 * 1024 * 1024 &&
1085 waitqueue_active(&root->fs_info->async_submit_wait))
1086 wake_up(&root->fs_info->async_submit_wait);
1087
1088 if (async_cow->inode)
1089 submit_compressed_extents(async_cow->inode, async_cow);
1090 }
1091
1092 static noinline void async_cow_free(struct btrfs_work *work)
1093 {
1094 struct async_cow *async_cow;
1095 async_cow = container_of(work, struct async_cow, work);
1096 if (async_cow->inode)
1097 btrfs_add_delayed_iput(async_cow->inode);
1098 kfree(async_cow);
1099 }
1100
1101 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1102 u64 start, u64 end, int *page_started,
1103 unsigned long *nr_written)
1104 {
1105 struct async_cow *async_cow;
1106 struct btrfs_root *root = BTRFS_I(inode)->root;
1107 unsigned long nr_pages;
1108 u64 cur_end;
1109 int limit = 10 * 1024 * 1024;
1110
1111 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1112 1, 0, NULL, GFP_NOFS);
1113 while (start < end) {
1114 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1115 BUG_ON(!async_cow); /* -ENOMEM */
1116 async_cow->inode = igrab(inode);
1117 async_cow->root = root;
1118 async_cow->locked_page = locked_page;
1119 async_cow->start = start;
1120
1121 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
1122 cur_end = end;
1123 else
1124 cur_end = min(end, start + 512 * 1024 - 1);
1125
1126 async_cow->end = cur_end;
1127 INIT_LIST_HEAD(&async_cow->extents);
1128
1129 async_cow->work.func = async_cow_start;
1130 async_cow->work.ordered_func = async_cow_submit;
1131 async_cow->work.ordered_free = async_cow_free;
1132 async_cow->work.flags = 0;
1133
1134 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
1135 PAGE_CACHE_SHIFT;
1136 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1137
1138 btrfs_queue_worker(&root->fs_info->delalloc_workers,
1139 &async_cow->work);
1140
1141 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1142 wait_event(root->fs_info->async_submit_wait,
1143 (atomic_read(&root->fs_info->async_delalloc_pages) <
1144 limit));
1145 }
1146
1147 while (atomic_read(&root->fs_info->async_submit_draining) &&
1148 atomic_read(&root->fs_info->async_delalloc_pages)) {
1149 wait_event(root->fs_info->async_submit_wait,
1150 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1151 0));
1152 }
1153
1154 *nr_written += nr_pages;
1155 start = cur_end + 1;
1156 }
1157 *page_started = 1;
1158 return 0;
1159 }
1160
1161 static noinline int csum_exist_in_range(struct btrfs_root *root,
1162 u64 bytenr, u64 num_bytes)
1163 {
1164 int ret;
1165 struct btrfs_ordered_sum *sums;
1166 LIST_HEAD(list);
1167
1168 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1169 bytenr + num_bytes - 1, &list, 0);
1170 if (ret == 0 && list_empty(&list))
1171 return 0;
1172
1173 while (!list_empty(&list)) {
1174 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1175 list_del(&sums->list);
1176 kfree(sums);
1177 }
1178 return 1;
1179 }
1180
1181 /*
1182 * when nowcow writeback call back. This checks for snapshots or COW copies
1183 * of the extents that exist in the file, and COWs the file as required.
1184 *
1185 * If no cow copies or snapshots exist, we write directly to the existing
1186 * blocks on disk
1187 */
1188 static noinline int run_delalloc_nocow(struct inode *inode,
1189 struct page *locked_page,
1190 u64 start, u64 end, int *page_started, int force,
1191 unsigned long *nr_written)
1192 {
1193 struct btrfs_root *root = BTRFS_I(inode)->root;
1194 struct btrfs_trans_handle *trans;
1195 struct extent_buffer *leaf;
1196 struct btrfs_path *path;
1197 struct btrfs_file_extent_item *fi;
1198 struct btrfs_key found_key;
1199 u64 cow_start;
1200 u64 cur_offset;
1201 u64 extent_end;
1202 u64 extent_offset;
1203 u64 disk_bytenr;
1204 u64 num_bytes;
1205 u64 disk_num_bytes;
1206 u64 ram_bytes;
1207 int extent_type;
1208 int ret, err;
1209 int type;
1210 int nocow;
1211 int check_prev = 1;
1212 bool nolock;
1213 u64 ino = btrfs_ino(inode);
1214
1215 path = btrfs_alloc_path();
1216 if (!path) {
1217 extent_clear_unlock_delalloc(inode,
1218 &BTRFS_I(inode)->io_tree,
1219 start, end, locked_page,
1220 EXTENT_CLEAR_UNLOCK_PAGE |
1221 EXTENT_CLEAR_UNLOCK |
1222 EXTENT_CLEAR_DELALLOC |
1223 EXTENT_CLEAR_DIRTY |
1224 EXTENT_SET_WRITEBACK |
1225 EXTENT_END_WRITEBACK);
1226 return -ENOMEM;
1227 }
1228
1229 nolock = btrfs_is_free_space_inode(inode);
1230
1231 if (nolock)
1232 trans = btrfs_join_transaction_nolock(root);
1233 else
1234 trans = btrfs_join_transaction(root);
1235
1236 if (IS_ERR(trans)) {
1237 extent_clear_unlock_delalloc(inode,
1238 &BTRFS_I(inode)->io_tree,
1239 start, end, locked_page,
1240 EXTENT_CLEAR_UNLOCK_PAGE |
1241 EXTENT_CLEAR_UNLOCK |
1242 EXTENT_CLEAR_DELALLOC |
1243 EXTENT_CLEAR_DIRTY |
1244 EXTENT_SET_WRITEBACK |
1245 EXTENT_END_WRITEBACK);
1246 btrfs_free_path(path);
1247 return PTR_ERR(trans);
1248 }
1249
1250 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1251
1252 cow_start = (u64)-1;
1253 cur_offset = start;
1254 while (1) {
1255 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1256 cur_offset, 0);
1257 if (ret < 0) {
1258 btrfs_abort_transaction(trans, root, ret);
1259 goto error;
1260 }
1261 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1262 leaf = path->nodes[0];
1263 btrfs_item_key_to_cpu(leaf, &found_key,
1264 path->slots[0] - 1);
1265 if (found_key.objectid == ino &&
1266 found_key.type == BTRFS_EXTENT_DATA_KEY)
1267 path->slots[0]--;
1268 }
1269 check_prev = 0;
1270 next_slot:
1271 leaf = path->nodes[0];
1272 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1273 ret = btrfs_next_leaf(root, path);
1274 if (ret < 0) {
1275 btrfs_abort_transaction(trans, root, ret);
1276 goto error;
1277 }
1278 if (ret > 0)
1279 break;
1280 leaf = path->nodes[0];
1281 }
1282
1283 nocow = 0;
1284 disk_bytenr = 0;
1285 num_bytes = 0;
1286 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1287
1288 if (found_key.objectid > ino ||
1289 found_key.type > BTRFS_EXTENT_DATA_KEY ||
1290 found_key.offset > end)
1291 break;
1292
1293 if (found_key.offset > cur_offset) {
1294 extent_end = found_key.offset;
1295 extent_type = 0;
1296 goto out_check;
1297 }
1298
1299 fi = btrfs_item_ptr(leaf, path->slots[0],
1300 struct btrfs_file_extent_item);
1301 extent_type = btrfs_file_extent_type(leaf, fi);
1302
1303 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1304 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1305 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1306 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1307 extent_offset = btrfs_file_extent_offset(leaf, fi);
1308 extent_end = found_key.offset +
1309 btrfs_file_extent_num_bytes(leaf, fi);
1310 disk_num_bytes =
1311 btrfs_file_extent_disk_num_bytes(leaf, fi);
1312 if (extent_end <= start) {
1313 path->slots[0]++;
1314 goto next_slot;
1315 }
1316 if (disk_bytenr == 0)
1317 goto out_check;
1318 if (btrfs_file_extent_compression(leaf, fi) ||
1319 btrfs_file_extent_encryption(leaf, fi) ||
1320 btrfs_file_extent_other_encoding(leaf, fi))
1321 goto out_check;
1322 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1323 goto out_check;
1324 if (btrfs_extent_readonly(root, disk_bytenr))
1325 goto out_check;
1326 if (btrfs_cross_ref_exist(trans, root, ino,
1327 found_key.offset -
1328 extent_offset, disk_bytenr))
1329 goto out_check;
1330 disk_bytenr += extent_offset;
1331 disk_bytenr += cur_offset - found_key.offset;
1332 num_bytes = min(end + 1, extent_end) - cur_offset;
1333 /*
1334 * force cow if csum exists in the range.
1335 * this ensure that csum for a given extent are
1336 * either valid or do not exist.
1337 */
1338 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1339 goto out_check;
1340 nocow = 1;
1341 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1342 extent_end = found_key.offset +
1343 btrfs_file_extent_inline_len(leaf, fi);
1344 extent_end = ALIGN(extent_end, root->sectorsize);
1345 } else {
1346 BUG_ON(1);
1347 }
1348 out_check:
1349 if (extent_end <= start) {
1350 path->slots[0]++;
1351 goto next_slot;
1352 }
1353 if (!nocow) {
1354 if (cow_start == (u64)-1)
1355 cow_start = cur_offset;
1356 cur_offset = extent_end;
1357 if (cur_offset > end)
1358 break;
1359 path->slots[0]++;
1360 goto next_slot;
1361 }
1362
1363 btrfs_release_path(path);
1364 if (cow_start != (u64)-1) {
1365 ret = __cow_file_range(trans, inode, root, locked_page,
1366 cow_start, found_key.offset - 1,
1367 page_started, nr_written, 1);
1368 if (ret) {
1369 btrfs_abort_transaction(trans, root, ret);
1370 goto error;
1371 }
1372 cow_start = (u64)-1;
1373 }
1374
1375 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1376 struct extent_map *em;
1377 struct extent_map_tree *em_tree;
1378 em_tree = &BTRFS_I(inode)->extent_tree;
1379 em = alloc_extent_map();
1380 BUG_ON(!em); /* -ENOMEM */
1381 em->start = cur_offset;
1382 em->orig_start = found_key.offset - extent_offset;
1383 em->len = num_bytes;
1384 em->block_len = num_bytes;
1385 em->block_start = disk_bytenr;
1386 em->orig_block_len = disk_num_bytes;
1387 em->ram_bytes = ram_bytes;
1388 em->bdev = root->fs_info->fs_devices->latest_bdev;
1389 em->mod_start = em->start;
1390 em->mod_len = em->len;
1391 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1392 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1393 em->generation = -1;
1394 while (1) {
1395 write_lock(&em_tree->lock);
1396 ret = add_extent_mapping(em_tree, em, 1);
1397 write_unlock(&em_tree->lock);
1398 if (ret != -EEXIST) {
1399 free_extent_map(em);
1400 break;
1401 }
1402 btrfs_drop_extent_cache(inode, em->start,
1403 em->start + em->len - 1, 0);
1404 }
1405 type = BTRFS_ORDERED_PREALLOC;
1406 } else {
1407 type = BTRFS_ORDERED_NOCOW;
1408 }
1409
1410 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1411 num_bytes, num_bytes, type);
1412 BUG_ON(ret); /* -ENOMEM */
1413
1414 if (root->root_key.objectid ==
1415 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1416 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1417 num_bytes);
1418 if (ret) {
1419 btrfs_abort_transaction(trans, root, ret);
1420 goto error;
1421 }
1422 }
1423
1424 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
1425 cur_offset, cur_offset + num_bytes - 1,
1426 locked_page, EXTENT_CLEAR_UNLOCK_PAGE |
1427 EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
1428 EXTENT_SET_PRIVATE2);
1429 cur_offset = extent_end;
1430 if (cur_offset > end)
1431 break;
1432 }
1433 btrfs_release_path(path);
1434
1435 if (cur_offset <= end && cow_start == (u64)-1) {
1436 cow_start = cur_offset;
1437 cur_offset = end;
1438 }
1439
1440 if (cow_start != (u64)-1) {
1441 ret = __cow_file_range(trans, inode, root, locked_page,
1442 cow_start, end,
1443 page_started, nr_written, 1);
1444 if (ret) {
1445 btrfs_abort_transaction(trans, root, ret);
1446 goto error;
1447 }
1448 }
1449
1450 error:
1451 err = btrfs_end_transaction(trans, root);
1452 if (!ret)
1453 ret = err;
1454
1455 if (ret && cur_offset < end)
1456 extent_clear_unlock_delalloc(inode,
1457 &BTRFS_I(inode)->io_tree,
1458 cur_offset, end, locked_page,
1459 EXTENT_CLEAR_UNLOCK_PAGE |
1460 EXTENT_CLEAR_UNLOCK |
1461 EXTENT_CLEAR_DELALLOC |
1462 EXTENT_CLEAR_DIRTY |
1463 EXTENT_SET_WRITEBACK |
1464 EXTENT_END_WRITEBACK);
1465
1466 btrfs_free_path(path);
1467 return ret;
1468 }
1469
1470 /*
1471 * extent_io.c call back to do delayed allocation processing
1472 */
1473 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1474 u64 start, u64 end, int *page_started,
1475 unsigned long *nr_written)
1476 {
1477 int ret;
1478 struct btrfs_root *root = BTRFS_I(inode)->root;
1479
1480 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) {
1481 ret = run_delalloc_nocow(inode, locked_page, start, end,
1482 page_started, 1, nr_written);
1483 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC) {
1484 ret = run_delalloc_nocow(inode, locked_page, start, end,
1485 page_started, 0, nr_written);
1486 } else if (!btrfs_test_opt(root, COMPRESS) &&
1487 !(BTRFS_I(inode)->force_compress) &&
1488 !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS)) {
1489 ret = cow_file_range(inode, locked_page, start, end,
1490 page_started, nr_written, 1);
1491 } else {
1492 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1493 &BTRFS_I(inode)->runtime_flags);
1494 ret = cow_file_range_async(inode, locked_page, start, end,
1495 page_started, nr_written);
1496 }
1497 return ret;
1498 }
1499
1500 static void btrfs_split_extent_hook(struct inode *inode,
1501 struct extent_state *orig, u64 split)
1502 {
1503 /* not delalloc, ignore it */
1504 if (!(orig->state & EXTENT_DELALLOC))
1505 return;
1506
1507 spin_lock(&BTRFS_I(inode)->lock);
1508 BTRFS_I(inode)->outstanding_extents++;
1509 spin_unlock(&BTRFS_I(inode)->lock);
1510 }
1511
1512 /*
1513 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1514 * extents so we can keep track of new extents that are just merged onto old
1515 * extents, such as when we are doing sequential writes, so we can properly
1516 * account for the metadata space we'll need.
1517 */
1518 static void btrfs_merge_extent_hook(struct inode *inode,
1519 struct extent_state *new,
1520 struct extent_state *other)
1521 {
1522 /* not delalloc, ignore it */
1523 if (!(other->state & EXTENT_DELALLOC))
1524 return;
1525
1526 spin_lock(&BTRFS_I(inode)->lock);
1527 BTRFS_I(inode)->outstanding_extents--;
1528 spin_unlock(&BTRFS_I(inode)->lock);
1529 }
1530
1531 /*
1532 * extent_io.c set_bit_hook, used to track delayed allocation
1533 * bytes in this file, and to maintain the list of inodes that
1534 * have pending delalloc work to be done.
1535 */
1536 static void btrfs_set_bit_hook(struct inode *inode,
1537 struct extent_state *state, unsigned long *bits)
1538 {
1539
1540 /*
1541 * set_bit and clear bit hooks normally require _irqsave/restore
1542 * but in this case, we are only testing for the DELALLOC
1543 * bit, which is only set or cleared with irqs on
1544 */
1545 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1546 struct btrfs_root *root = BTRFS_I(inode)->root;
1547 u64 len = state->end + 1 - state->start;
1548 bool do_list = !btrfs_is_free_space_inode(inode);
1549
1550 if (*bits & EXTENT_FIRST_DELALLOC) {
1551 *bits &= ~EXTENT_FIRST_DELALLOC;
1552 } else {
1553 spin_lock(&BTRFS_I(inode)->lock);
1554 BTRFS_I(inode)->outstanding_extents++;
1555 spin_unlock(&BTRFS_I(inode)->lock);
1556 }
1557
1558 __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
1559 root->fs_info->delalloc_batch);
1560 spin_lock(&BTRFS_I(inode)->lock);
1561 BTRFS_I(inode)->delalloc_bytes += len;
1562 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1563 &BTRFS_I(inode)->runtime_flags)) {
1564 spin_lock(&root->fs_info->delalloc_lock);
1565 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1566 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1567 &root->fs_info->delalloc_inodes);
1568 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1569 &BTRFS_I(inode)->runtime_flags);
1570 }
1571 spin_unlock(&root->fs_info->delalloc_lock);
1572 }
1573 spin_unlock(&BTRFS_I(inode)->lock);
1574 }
1575 }
1576
1577 /*
1578 * extent_io.c clear_bit_hook, see set_bit_hook for why
1579 */
1580 static void btrfs_clear_bit_hook(struct inode *inode,
1581 struct extent_state *state,
1582 unsigned long *bits)
1583 {
1584 /*
1585 * set_bit and clear bit hooks normally require _irqsave/restore
1586 * but in this case, we are only testing for the DELALLOC
1587 * bit, which is only set or cleared with irqs on
1588 */
1589 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1590 struct btrfs_root *root = BTRFS_I(inode)->root;
1591 u64 len = state->end + 1 - state->start;
1592 bool do_list = !btrfs_is_free_space_inode(inode);
1593
1594 if (*bits & EXTENT_FIRST_DELALLOC) {
1595 *bits &= ~EXTENT_FIRST_DELALLOC;
1596 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1597 spin_lock(&BTRFS_I(inode)->lock);
1598 BTRFS_I(inode)->outstanding_extents--;
1599 spin_unlock(&BTRFS_I(inode)->lock);
1600 }
1601
1602 if (*bits & EXTENT_DO_ACCOUNTING)
1603 btrfs_delalloc_release_metadata(inode, len);
1604
1605 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1606 && do_list)
1607 btrfs_free_reserved_data_space(inode, len);
1608
1609 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
1610 root->fs_info->delalloc_batch);
1611 spin_lock(&BTRFS_I(inode)->lock);
1612 BTRFS_I(inode)->delalloc_bytes -= len;
1613 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1614 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1615 &BTRFS_I(inode)->runtime_flags)) {
1616 spin_lock(&root->fs_info->delalloc_lock);
1617 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1618 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1619 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1620 &BTRFS_I(inode)->runtime_flags);
1621 }
1622 spin_unlock(&root->fs_info->delalloc_lock);
1623 }
1624 spin_unlock(&BTRFS_I(inode)->lock);
1625 }
1626 }
1627
1628 /*
1629 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1630 * we don't create bios that span stripes or chunks
1631 */
1632 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
1633 size_t size, struct bio *bio,
1634 unsigned long bio_flags)
1635 {
1636 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1637 u64 logical = (u64)bio->bi_sector << 9;
1638 u64 length = 0;
1639 u64 map_length;
1640 int ret;
1641
1642 if (bio_flags & EXTENT_BIO_COMPRESSED)
1643 return 0;
1644
1645 length = bio->bi_size;
1646 map_length = length;
1647 ret = btrfs_map_block(root->fs_info, rw, logical,
1648 &map_length, NULL, 0);
1649 /* Will always return 0 with map_multi == NULL */
1650 BUG_ON(ret < 0);
1651 if (map_length < length + size)
1652 return 1;
1653 return 0;
1654 }
1655
1656 /*
1657 * in order to insert checksums into the metadata in large chunks,
1658 * we wait until bio submission time. All the pages in the bio are
1659 * checksummed and sums are attached onto the ordered extent record.
1660 *
1661 * At IO completion time the cums attached on the ordered extent record
1662 * are inserted into the btree
1663 */
1664 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1665 struct bio *bio, int mirror_num,
1666 unsigned long bio_flags,
1667 u64 bio_offset)
1668 {
1669 struct btrfs_root *root = BTRFS_I(inode)->root;
1670 int ret = 0;
1671
1672 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1673 BUG_ON(ret); /* -ENOMEM */
1674 return 0;
1675 }
1676
1677 /*
1678 * in order to insert checksums into the metadata in large chunks,
1679 * we wait until bio submission time. All the pages in the bio are
1680 * checksummed and sums are attached onto the ordered extent record.
1681 *
1682 * At IO completion time the cums attached on the ordered extent record
1683 * are inserted into the btree
1684 */
1685 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1686 int mirror_num, unsigned long bio_flags,
1687 u64 bio_offset)
1688 {
1689 struct btrfs_root *root = BTRFS_I(inode)->root;
1690 int ret;
1691
1692 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
1693 if (ret)
1694 bio_endio(bio, ret);
1695 return ret;
1696 }
1697
1698 /*
1699 * extent_io.c submission hook. This does the right thing for csum calculation
1700 * on write, or reading the csums from the tree before a read
1701 */
1702 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1703 int mirror_num, unsigned long bio_flags,
1704 u64 bio_offset)
1705 {
1706 struct btrfs_root *root = BTRFS_I(inode)->root;
1707 int ret = 0;
1708 int skip_sum;
1709 int metadata = 0;
1710 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1711
1712 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1713
1714 if (btrfs_is_free_space_inode(inode))
1715 metadata = 2;
1716
1717 if (!(rw & REQ_WRITE)) {
1718 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1719 if (ret)
1720 goto out;
1721
1722 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1723 ret = btrfs_submit_compressed_read(inode, bio,
1724 mirror_num,
1725 bio_flags);
1726 goto out;
1727 } else if (!skip_sum) {
1728 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1729 if (ret)
1730 goto out;
1731 }
1732 goto mapit;
1733 } else if (async && !skip_sum) {
1734 /* csum items have already been cloned */
1735 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1736 goto mapit;
1737 /* we're doing a write, do the async checksumming */
1738 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1739 inode, rw, bio, mirror_num,
1740 bio_flags, bio_offset,
1741 __btrfs_submit_bio_start,
1742 __btrfs_submit_bio_done);
1743 goto out;
1744 } else if (!skip_sum) {
1745 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1746 if (ret)
1747 goto out;
1748 }
1749
1750 mapit:
1751 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
1752
1753 out:
1754 if (ret < 0)
1755 bio_endio(bio, ret);
1756 return ret;
1757 }
1758
1759 /*
1760 * given a list of ordered sums record them in the inode. This happens
1761 * at IO completion time based on sums calculated at bio submission time.
1762 */
1763 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1764 struct inode *inode, u64 file_offset,
1765 struct list_head *list)
1766 {
1767 struct btrfs_ordered_sum *sum;
1768
1769 list_for_each_entry(sum, list, list) {
1770 trans->adding_csums = 1;
1771 btrfs_csum_file_blocks(trans,
1772 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1773 trans->adding_csums = 0;
1774 }
1775 return 0;
1776 }
1777
1778 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1779 struct extent_state **cached_state)
1780 {
1781 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0);
1782 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1783 cached_state, GFP_NOFS);
1784 }
1785
1786 /* see btrfs_writepage_start_hook for details on why this is required */
1787 struct btrfs_writepage_fixup {
1788 struct page *page;
1789 struct btrfs_work work;
1790 };
1791
1792 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1793 {
1794 struct btrfs_writepage_fixup *fixup;
1795 struct btrfs_ordered_extent *ordered;
1796 struct extent_state *cached_state = NULL;
1797 struct page *page;
1798 struct inode *inode;
1799 u64 page_start;
1800 u64 page_end;
1801 int ret;
1802
1803 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1804 page = fixup->page;
1805 again:
1806 lock_page(page);
1807 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1808 ClearPageChecked(page);
1809 goto out_page;
1810 }
1811
1812 inode = page->mapping->host;
1813 page_start = page_offset(page);
1814 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1815
1816 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
1817 &cached_state);
1818
1819 /* already ordered? We're done */
1820 if (PagePrivate2(page))
1821 goto out;
1822
1823 ordered = btrfs_lookup_ordered_extent(inode, page_start);
1824 if (ordered) {
1825 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
1826 page_end, &cached_state, GFP_NOFS);
1827 unlock_page(page);
1828 btrfs_start_ordered_extent(inode, ordered, 1);
1829 btrfs_put_ordered_extent(ordered);
1830 goto again;
1831 }
1832
1833 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
1834 if (ret) {
1835 mapping_set_error(page->mapping, ret);
1836 end_extent_writepage(page, ret, page_start, page_end);
1837 ClearPageChecked(page);
1838 goto out;
1839 }
1840
1841 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
1842 ClearPageChecked(page);
1843 set_page_dirty(page);
1844 out:
1845 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
1846 &cached_state, GFP_NOFS);
1847 out_page:
1848 unlock_page(page);
1849 page_cache_release(page);
1850 kfree(fixup);
1851 }
1852
1853 /*
1854 * There are a few paths in the higher layers of the kernel that directly
1855 * set the page dirty bit without asking the filesystem if it is a
1856 * good idea. This causes problems because we want to make sure COW
1857 * properly happens and the data=ordered rules are followed.
1858 *
1859 * In our case any range that doesn't have the ORDERED bit set
1860 * hasn't been properly setup for IO. We kick off an async process
1861 * to fix it up. The async helper will wait for ordered extents, set
1862 * the delalloc bit and make it safe to write the page.
1863 */
1864 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
1865 {
1866 struct inode *inode = page->mapping->host;
1867 struct btrfs_writepage_fixup *fixup;
1868 struct btrfs_root *root = BTRFS_I(inode)->root;
1869
1870 /* this page is properly in the ordered list */
1871 if (TestClearPagePrivate2(page))
1872 return 0;
1873
1874 if (PageChecked(page))
1875 return -EAGAIN;
1876
1877 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
1878 if (!fixup)
1879 return -EAGAIN;
1880
1881 SetPageChecked(page);
1882 page_cache_get(page);
1883 fixup->work.func = btrfs_writepage_fixup_worker;
1884 fixup->page = page;
1885 btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
1886 return -EBUSY;
1887 }
1888
1889 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
1890 struct inode *inode, u64 file_pos,
1891 u64 disk_bytenr, u64 disk_num_bytes,
1892 u64 num_bytes, u64 ram_bytes,
1893 u8 compression, u8 encryption,
1894 u16 other_encoding, int extent_type)
1895 {
1896 struct btrfs_root *root = BTRFS_I(inode)->root;
1897 struct btrfs_file_extent_item *fi;
1898 struct btrfs_path *path;
1899 struct extent_buffer *leaf;
1900 struct btrfs_key ins;
1901 int ret;
1902
1903 path = btrfs_alloc_path();
1904 if (!path)
1905 return -ENOMEM;
1906
1907 path->leave_spinning = 1;
1908
1909 /*
1910 * we may be replacing one extent in the tree with another.
1911 * The new extent is pinned in the extent map, and we don't want
1912 * to drop it from the cache until it is completely in the btree.
1913 *
1914 * So, tell btrfs_drop_extents to leave this extent in the cache.
1915 * the caller is expected to unpin it and allow it to be merged
1916 * with the others.
1917 */
1918 ret = btrfs_drop_extents(trans, root, inode, file_pos,
1919 file_pos + num_bytes, 0);
1920 if (ret)
1921 goto out;
1922
1923 ins.objectid = btrfs_ino(inode);
1924 ins.offset = file_pos;
1925 ins.type = BTRFS_EXTENT_DATA_KEY;
1926 ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi));
1927 if (ret)
1928 goto out;
1929 leaf = path->nodes[0];
1930 fi = btrfs_item_ptr(leaf, path->slots[0],
1931 struct btrfs_file_extent_item);
1932 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1933 btrfs_set_file_extent_type(leaf, fi, extent_type);
1934 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
1935 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
1936 btrfs_set_file_extent_offset(leaf, fi, 0);
1937 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
1938 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
1939 btrfs_set_file_extent_compression(leaf, fi, compression);
1940 btrfs_set_file_extent_encryption(leaf, fi, encryption);
1941 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
1942
1943 btrfs_mark_buffer_dirty(leaf);
1944 btrfs_release_path(path);
1945
1946 inode_add_bytes(inode, num_bytes);
1947
1948 ins.objectid = disk_bytenr;
1949 ins.offset = disk_num_bytes;
1950 ins.type = BTRFS_EXTENT_ITEM_KEY;
1951 ret = btrfs_alloc_reserved_file_extent(trans, root,
1952 root->root_key.objectid,
1953 btrfs_ino(inode), file_pos, &ins);
1954 out:
1955 btrfs_free_path(path);
1956
1957 return ret;
1958 }
1959
1960 /* snapshot-aware defrag */
1961 struct sa_defrag_extent_backref {
1962 struct rb_node node;
1963 struct old_sa_defrag_extent *old;
1964 u64 root_id;
1965 u64 inum;
1966 u64 file_pos;
1967 u64 extent_offset;
1968 u64 num_bytes;
1969 u64 generation;
1970 };
1971
1972 struct old_sa_defrag_extent {
1973 struct list_head list;
1974 struct new_sa_defrag_extent *new;
1975
1976 u64 extent_offset;
1977 u64 bytenr;
1978 u64 offset;
1979 u64 len;
1980 int count;
1981 };
1982
1983 struct new_sa_defrag_extent {
1984 struct rb_root root;
1985 struct list_head head;
1986 struct btrfs_path *path;
1987 struct inode *inode;
1988 u64 file_pos;
1989 u64 len;
1990 u64 bytenr;
1991 u64 disk_len;
1992 u8 compress_type;
1993 };
1994
1995 static int backref_comp(struct sa_defrag_extent_backref *b1,
1996 struct sa_defrag_extent_backref *b2)
1997 {
1998 if (b1->root_id < b2->root_id)
1999 return -1;
2000 else if (b1->root_id > b2->root_id)
2001 return 1;
2002
2003 if (b1->inum < b2->inum)
2004 return -1;
2005 else if (b1->inum > b2->inum)
2006 return 1;
2007
2008 if (b1->file_pos < b2->file_pos)
2009 return -1;
2010 else if (b1->file_pos > b2->file_pos)
2011 return 1;
2012
2013 /*
2014 * [------------------------------] ===> (a range of space)
2015 * |<--->| |<---->| =============> (fs/file tree A)
2016 * |<---------------------------->| ===> (fs/file tree B)
2017 *
2018 * A range of space can refer to two file extents in one tree while
2019 * refer to only one file extent in another tree.
2020 *
2021 * So we may process a disk offset more than one time(two extents in A)
2022 * and locate at the same extent(one extent in B), then insert two same
2023 * backrefs(both refer to the extent in B).
2024 */
2025 return 0;
2026 }
2027
2028 static void backref_insert(struct rb_root *root,
2029 struct sa_defrag_extent_backref *backref)
2030 {
2031 struct rb_node **p = &root->rb_node;
2032 struct rb_node *parent = NULL;
2033 struct sa_defrag_extent_backref *entry;
2034 int ret;
2035
2036 while (*p) {
2037 parent = *p;
2038 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2039
2040 ret = backref_comp(backref, entry);
2041 if (ret < 0)
2042 p = &(*p)->rb_left;
2043 else
2044 p = &(*p)->rb_right;
2045 }
2046
2047 rb_link_node(&backref->node, parent, p);
2048 rb_insert_color(&backref->node, root);
2049 }
2050
2051 /*
2052 * Note the backref might has changed, and in this case we just return 0.
2053 */
2054 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2055 void *ctx)
2056 {
2057 struct btrfs_file_extent_item *extent;
2058 struct btrfs_fs_info *fs_info;
2059 struct old_sa_defrag_extent *old = ctx;
2060 struct new_sa_defrag_extent *new = old->new;
2061 struct btrfs_path *path = new->path;
2062 struct btrfs_key key;
2063 struct btrfs_root *root;
2064 struct sa_defrag_extent_backref *backref;
2065 struct extent_buffer *leaf;
2066 struct inode *inode = new->inode;
2067 int slot;
2068 int ret;
2069 u64 extent_offset;
2070 u64 num_bytes;
2071
2072 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2073 inum == btrfs_ino(inode))
2074 return 0;
2075
2076 key.objectid = root_id;
2077 key.type = BTRFS_ROOT_ITEM_KEY;
2078 key.offset = (u64)-1;
2079
2080 fs_info = BTRFS_I(inode)->root->fs_info;
2081 root = btrfs_read_fs_root_no_name(fs_info, &key);
2082 if (IS_ERR(root)) {
2083 if (PTR_ERR(root) == -ENOENT)
2084 return 0;
2085 WARN_ON(1);
2086 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
2087 inum, offset, root_id);
2088 return PTR_ERR(root);
2089 }
2090
2091 key.objectid = inum;
2092 key.type = BTRFS_EXTENT_DATA_KEY;
2093 if (offset > (u64)-1 << 32)
2094 key.offset = 0;
2095 else
2096 key.offset = offset;
2097
2098 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2099 if (ret < 0) {
2100 WARN_ON(1);
2101 return ret;
2102 }
2103
2104 while (1) {
2105 cond_resched();
2106
2107 leaf = path->nodes[0];
2108 slot = path->slots[0];
2109
2110 if (slot >= btrfs_header_nritems(leaf)) {
2111 ret = btrfs_next_leaf(root, path);
2112 if (ret < 0) {
2113 goto out;
2114 } else if (ret > 0) {
2115 ret = 0;
2116 goto out;
2117 }
2118 continue;
2119 }
2120
2121 path->slots[0]++;
2122
2123 btrfs_item_key_to_cpu(leaf, &key, slot);
2124
2125 if (key.objectid > inum)
2126 goto out;
2127
2128 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2129 continue;
2130
2131 extent = btrfs_item_ptr(leaf, slot,
2132 struct btrfs_file_extent_item);
2133
2134 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2135 continue;
2136
2137 extent_offset = btrfs_file_extent_offset(leaf, extent);
2138 if (key.offset - extent_offset != offset)
2139 continue;
2140
2141 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2142 if (extent_offset >= old->extent_offset + old->offset +
2143 old->len || extent_offset + num_bytes <=
2144 old->extent_offset + old->offset)
2145 continue;
2146
2147 break;
2148 }
2149
2150 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2151 if (!backref) {
2152 ret = -ENOENT;
2153 goto out;
2154 }
2155
2156 backref->root_id = root_id;
2157 backref->inum = inum;
2158 backref->file_pos = offset + extent_offset;
2159 backref->num_bytes = num_bytes;
2160 backref->extent_offset = extent_offset;
2161 backref->generation = btrfs_file_extent_generation(leaf, extent);
2162 backref->old = old;
2163 backref_insert(&new->root, backref);
2164 old->count++;
2165 out:
2166 btrfs_release_path(path);
2167 WARN_ON(ret);
2168 return ret;
2169 }
2170
2171 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2172 struct new_sa_defrag_extent *new)
2173 {
2174 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
2175 struct old_sa_defrag_extent *old, *tmp;
2176 int ret;
2177
2178 new->path = path;
2179
2180 list_for_each_entry_safe(old, tmp, &new->head, list) {
2181 ret = iterate_inodes_from_logical(old->bytenr, fs_info,
2182 path, record_one_backref,
2183 old);
2184 BUG_ON(ret < 0 && ret != -ENOENT);
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 u64 disk_bytenr)
2202 {
2203 if (btrfs_file_extent_disk_bytenr(leaf, fi) != disk_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) ||
2210 btrfs_file_extent_encryption(leaf, fi) ||
2211 btrfs_file_extent_other_encoding(leaf, fi))
2212 return 0;
2213
2214 return 1;
2215 }
2216
2217 /*
2218 * Note the backref might has changed, and in this case we just return 0.
2219 */
2220 static noinline int relink_extent_backref(struct btrfs_path *path,
2221 struct sa_defrag_extent_backref *prev,
2222 struct sa_defrag_extent_backref *backref)
2223 {
2224 struct btrfs_file_extent_item *extent;
2225 struct btrfs_file_extent_item *item;
2226 struct btrfs_ordered_extent *ordered;
2227 struct btrfs_trans_handle *trans;
2228 struct btrfs_fs_info *fs_info;
2229 struct btrfs_root *root;
2230 struct btrfs_key key;
2231 struct extent_buffer *leaf;
2232 struct old_sa_defrag_extent *old = backref->old;
2233 struct new_sa_defrag_extent *new = old->new;
2234 struct inode *src_inode = new->inode;
2235 struct inode *inode;
2236 struct extent_state *cached = NULL;
2237 int ret = 0;
2238 u64 start;
2239 u64 len;
2240 u64 lock_start;
2241 u64 lock_end;
2242 bool merge = false;
2243 int index;
2244
2245 if (prev && prev->root_id == backref->root_id &&
2246 prev->inum == backref->inum &&
2247 prev->file_pos + prev->num_bytes == backref->file_pos)
2248 merge = true;
2249
2250 /* step 1: get root */
2251 key.objectid = backref->root_id;
2252 key.type = BTRFS_ROOT_ITEM_KEY;
2253 key.offset = (u64)-1;
2254
2255 fs_info = BTRFS_I(src_inode)->root->fs_info;
2256 index = srcu_read_lock(&fs_info->subvol_srcu);
2257
2258 root = btrfs_read_fs_root_no_name(fs_info, &key);
2259 if (IS_ERR(root)) {
2260 srcu_read_unlock(&fs_info->subvol_srcu, index);
2261 if (PTR_ERR(root) == -ENOENT)
2262 return 0;
2263 return PTR_ERR(root);
2264 }
2265 if (btrfs_root_refs(&root->root_item) == 0) {
2266 srcu_read_unlock(&fs_info->subvol_srcu, index);
2267 /* parse ENOENT to 0 */
2268 return 0;
2269 }
2270
2271 /* step 2: get inode */
2272 key.objectid = backref->inum;
2273 key.type = BTRFS_INODE_ITEM_KEY;
2274 key.offset = 0;
2275
2276 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2277 if (IS_ERR(inode)) {
2278 srcu_read_unlock(&fs_info->subvol_srcu, index);
2279 return 0;
2280 }
2281
2282 srcu_read_unlock(&fs_info->subvol_srcu, index);
2283
2284 /* step 3: relink backref */
2285 lock_start = backref->file_pos;
2286 lock_end = backref->file_pos + backref->num_bytes - 1;
2287 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2288 0, &cached);
2289
2290 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2291 if (ordered) {
2292 btrfs_put_ordered_extent(ordered);
2293 goto out_unlock;
2294 }
2295
2296 trans = btrfs_join_transaction(root);
2297 if (IS_ERR(trans)) {
2298 ret = PTR_ERR(trans);
2299 goto out_unlock;
2300 }
2301
2302 key.objectid = backref->inum;
2303 key.type = BTRFS_EXTENT_DATA_KEY;
2304 key.offset = backref->file_pos;
2305
2306 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2307 if (ret < 0) {
2308 goto out_free_path;
2309 } else if (ret > 0) {
2310 ret = 0;
2311 goto out_free_path;
2312 }
2313
2314 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2315 struct btrfs_file_extent_item);
2316
2317 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2318 backref->generation)
2319 goto out_free_path;
2320
2321 btrfs_release_path(path);
2322
2323 start = backref->file_pos;
2324 if (backref->extent_offset < old->extent_offset + old->offset)
2325 start += old->extent_offset + old->offset -
2326 backref->extent_offset;
2327
2328 len = min(backref->extent_offset + backref->num_bytes,
2329 old->extent_offset + old->offset + old->len);
2330 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2331
2332 ret = btrfs_drop_extents(trans, root, inode, start,
2333 start + len, 1);
2334 if (ret)
2335 goto out_free_path;
2336 again:
2337 key.objectid = btrfs_ino(inode);
2338 key.type = BTRFS_EXTENT_DATA_KEY;
2339 key.offset = start;
2340
2341 path->leave_spinning = 1;
2342 if (merge) {
2343 struct btrfs_file_extent_item *fi;
2344 u64 extent_len;
2345 struct btrfs_key found_key;
2346
2347 ret = btrfs_search_slot(trans, root, &key, path, 1, 1);
2348 if (ret < 0)
2349 goto out_free_path;
2350
2351 path->slots[0]--;
2352 leaf = path->nodes[0];
2353 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2354
2355 fi = btrfs_item_ptr(leaf, path->slots[0],
2356 struct btrfs_file_extent_item);
2357 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2358
2359 if (relink_is_mergable(leaf, fi, new->bytenr) &&
2360 extent_len + found_key.offset == start) {
2361 btrfs_set_file_extent_num_bytes(leaf, fi,
2362 extent_len + len);
2363 btrfs_mark_buffer_dirty(leaf);
2364 inode_add_bytes(inode, len);
2365
2366 ret = 1;
2367 goto out_free_path;
2368 } else {
2369 merge = false;
2370 btrfs_release_path(path);
2371 goto again;
2372 }
2373 }
2374
2375 ret = btrfs_insert_empty_item(trans, root, path, &key,
2376 sizeof(*extent));
2377 if (ret) {
2378 btrfs_abort_transaction(trans, root, ret);
2379 goto out_free_path;
2380 }
2381
2382 leaf = path->nodes[0];
2383 item = btrfs_item_ptr(leaf, path->slots[0],
2384 struct btrfs_file_extent_item);
2385 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2386 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2387 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2388 btrfs_set_file_extent_num_bytes(leaf, item, len);
2389 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2390 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2391 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2392 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2393 btrfs_set_file_extent_encryption(leaf, item, 0);
2394 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2395
2396 btrfs_mark_buffer_dirty(leaf);
2397 inode_add_bytes(inode, len);
2398 btrfs_release_path(path);
2399
2400 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2401 new->disk_len, 0,
2402 backref->root_id, backref->inum,
2403 new->file_pos, 0); /* start - extent_offset */
2404 if (ret) {
2405 btrfs_abort_transaction(trans, root, ret);
2406 goto out_free_path;
2407 }
2408
2409 ret = 1;
2410 out_free_path:
2411 btrfs_release_path(path);
2412 path->leave_spinning = 0;
2413 btrfs_end_transaction(trans, root);
2414 out_unlock:
2415 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2416 &cached, GFP_NOFS);
2417 iput(inode);
2418 return ret;
2419 }
2420
2421 static void relink_file_extents(struct new_sa_defrag_extent *new)
2422 {
2423 struct btrfs_path *path;
2424 struct old_sa_defrag_extent *old, *tmp;
2425 struct sa_defrag_extent_backref *backref;
2426 struct sa_defrag_extent_backref *prev = NULL;
2427 struct inode *inode;
2428 struct btrfs_root *root;
2429 struct rb_node *node;
2430 int ret;
2431
2432 inode = new->inode;
2433 root = BTRFS_I(inode)->root;
2434
2435 path = btrfs_alloc_path();
2436 if (!path)
2437 return;
2438
2439 if (!record_extent_backrefs(path, new)) {
2440 btrfs_free_path(path);
2441 goto out;
2442 }
2443 btrfs_release_path(path);
2444
2445 while (1) {
2446 node = rb_first(&new->root);
2447 if (!node)
2448 break;
2449 rb_erase(node, &new->root);
2450
2451 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2452
2453 ret = relink_extent_backref(path, prev, backref);
2454 WARN_ON(ret < 0);
2455
2456 kfree(prev);
2457
2458 if (ret == 1)
2459 prev = backref;
2460 else
2461 prev = NULL;
2462 cond_resched();
2463 }
2464 kfree(prev);
2465
2466 btrfs_free_path(path);
2467
2468 list_for_each_entry_safe(old, tmp, &new->head, list) {
2469 list_del(&old->list);
2470 kfree(old);
2471 }
2472 out:
2473 atomic_dec(&root->fs_info->defrag_running);
2474 wake_up(&root->fs_info->transaction_wait);
2475
2476 kfree(new);
2477 }
2478
2479 static struct new_sa_defrag_extent *
2480 record_old_file_extents(struct inode *inode,
2481 struct btrfs_ordered_extent *ordered)
2482 {
2483 struct btrfs_root *root = BTRFS_I(inode)->root;
2484 struct btrfs_path *path;
2485 struct btrfs_key key;
2486 struct old_sa_defrag_extent *old, *tmp;
2487 struct new_sa_defrag_extent *new;
2488 int ret;
2489
2490 new = kmalloc(sizeof(*new), GFP_NOFS);
2491 if (!new)
2492 return NULL;
2493
2494 new->inode = inode;
2495 new->file_pos = ordered->file_offset;
2496 new->len = ordered->len;
2497 new->bytenr = ordered->start;
2498 new->disk_len = ordered->disk_len;
2499 new->compress_type = ordered->compress_type;
2500 new->root = RB_ROOT;
2501 INIT_LIST_HEAD(&new->head);
2502
2503 path = btrfs_alloc_path();
2504 if (!path)
2505 goto out_kfree;
2506
2507 key.objectid = btrfs_ino(inode);
2508 key.type = BTRFS_EXTENT_DATA_KEY;
2509 key.offset = new->file_pos;
2510
2511 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2512 if (ret < 0)
2513 goto out_free_path;
2514 if (ret > 0 && path->slots[0] > 0)
2515 path->slots[0]--;
2516
2517 /* find out all the old extents for the file range */
2518 while (1) {
2519 struct btrfs_file_extent_item *extent;
2520 struct extent_buffer *l;
2521 int slot;
2522 u64 num_bytes;
2523 u64 offset;
2524 u64 end;
2525 u64 disk_bytenr;
2526 u64 extent_offset;
2527
2528 l = path->nodes[0];
2529 slot = path->slots[0];
2530
2531 if (slot >= btrfs_header_nritems(l)) {
2532 ret = btrfs_next_leaf(root, path);
2533 if (ret < 0)
2534 goto out_free_list;
2535 else if (ret > 0)
2536 break;
2537 continue;
2538 }
2539
2540 btrfs_item_key_to_cpu(l, &key, slot);
2541
2542 if (key.objectid != btrfs_ino(inode))
2543 break;
2544 if (key.type != BTRFS_EXTENT_DATA_KEY)
2545 break;
2546 if (key.offset >= new->file_pos + new->len)
2547 break;
2548
2549 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2550
2551 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2552 if (key.offset + num_bytes < new->file_pos)
2553 goto next;
2554
2555 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2556 if (!disk_bytenr)
2557 goto next;
2558
2559 extent_offset = btrfs_file_extent_offset(l, extent);
2560
2561 old = kmalloc(sizeof(*old), GFP_NOFS);
2562 if (!old)
2563 goto out_free_list;
2564
2565 offset = max(new->file_pos, key.offset);
2566 end = min(new->file_pos + new->len, key.offset + num_bytes);
2567
2568 old->bytenr = disk_bytenr;
2569 old->extent_offset = extent_offset;
2570 old->offset = offset - key.offset;
2571 old->len = end - offset;
2572 old->new = new;
2573 old->count = 0;
2574 list_add_tail(&old->list, &new->head);
2575 next:
2576 path->slots[0]++;
2577 cond_resched();
2578 }
2579
2580 btrfs_free_path(path);
2581 atomic_inc(&root->fs_info->defrag_running);
2582
2583 return new;
2584
2585 out_free_list:
2586 list_for_each_entry_safe(old, tmp, &new->head, list) {
2587 list_del(&old->list);
2588 kfree(old);
2589 }
2590 out_free_path:
2591 btrfs_free_path(path);
2592 out_kfree:
2593 kfree(new);
2594 return NULL;
2595 }
2596
2597 /*
2598 * helper function for btrfs_finish_ordered_io, this
2599 * just reads in some of the csum leaves to prime them into ram
2600 * before we start the transaction. It limits the amount of btree
2601 * reads required while inside the transaction.
2602 */
2603 /* as ordered data IO finishes, this gets called so we can finish
2604 * an ordered extent if the range of bytes in the file it covers are
2605 * fully written.
2606 */
2607 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2608 {
2609 struct inode *inode = ordered_extent->inode;
2610 struct btrfs_root *root = BTRFS_I(inode)->root;
2611 struct btrfs_trans_handle *trans = NULL;
2612 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2613 struct extent_state *cached_state = NULL;
2614 struct new_sa_defrag_extent *new = NULL;
2615 int compress_type = 0;
2616 int ret;
2617 bool nolock;
2618
2619 nolock = btrfs_is_free_space_inode(inode);
2620
2621 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2622 ret = -EIO;
2623 goto out;
2624 }
2625
2626 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2627 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2628 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2629 if (nolock)
2630 trans = btrfs_join_transaction_nolock(root);
2631 else
2632 trans = btrfs_join_transaction(root);
2633 if (IS_ERR(trans)) {
2634 ret = PTR_ERR(trans);
2635 trans = NULL;
2636 goto out;
2637 }
2638 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2639 ret = btrfs_update_inode_fallback(trans, root, inode);
2640 if (ret) /* -ENOMEM or corruption */
2641 btrfs_abort_transaction(trans, root, ret);
2642 goto out;
2643 }
2644
2645 lock_extent_bits(io_tree, ordered_extent->file_offset,
2646 ordered_extent->file_offset + ordered_extent->len - 1,
2647 0, &cached_state);
2648
2649 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2650 ordered_extent->file_offset + ordered_extent->len - 1,
2651 EXTENT_DEFRAG, 1, cached_state);
2652 if (ret) {
2653 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2654 if (last_snapshot >= BTRFS_I(inode)->generation)
2655 /* the inode is shared */
2656 new = record_old_file_extents(inode, ordered_extent);
2657
2658 clear_extent_bit(io_tree, ordered_extent->file_offset,
2659 ordered_extent->file_offset + ordered_extent->len - 1,
2660 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2661 }
2662
2663 if (nolock)
2664 trans = btrfs_join_transaction_nolock(root);
2665 else
2666 trans = btrfs_join_transaction(root);
2667 if (IS_ERR(trans)) {
2668 ret = PTR_ERR(trans);
2669 trans = NULL;
2670 goto out_unlock;
2671 }
2672 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2673
2674 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2675 compress_type = ordered_extent->compress_type;
2676 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2677 BUG_ON(compress_type);
2678 ret = btrfs_mark_extent_written(trans, inode,
2679 ordered_extent->file_offset,
2680 ordered_extent->file_offset +
2681 ordered_extent->len);
2682 } else {
2683 BUG_ON(root == root->fs_info->tree_root);
2684 ret = insert_reserved_file_extent(trans, inode,
2685 ordered_extent->file_offset,
2686 ordered_extent->start,
2687 ordered_extent->disk_len,
2688 ordered_extent->len,
2689 ordered_extent->len,
2690 compress_type, 0, 0,
2691 BTRFS_FILE_EXTENT_REG);
2692 }
2693 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2694 ordered_extent->file_offset, ordered_extent->len,
2695 trans->transid);
2696 if (ret < 0) {
2697 btrfs_abort_transaction(trans, root, ret);
2698 goto out_unlock;
2699 }
2700
2701 add_pending_csums(trans, inode, ordered_extent->file_offset,
2702 &ordered_extent->list);
2703
2704 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2705 ret = btrfs_update_inode_fallback(trans, root, inode);
2706 if (ret) { /* -ENOMEM or corruption */
2707 btrfs_abort_transaction(trans, root, ret);
2708 goto out_unlock;
2709 }
2710 ret = 0;
2711 out_unlock:
2712 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2713 ordered_extent->file_offset +
2714 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2715 out:
2716 if (root != root->fs_info->tree_root)
2717 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2718 if (trans)
2719 btrfs_end_transaction(trans, root);
2720
2721 if (ret) {
2722 clear_extent_uptodate(io_tree, ordered_extent->file_offset,
2723 ordered_extent->file_offset +
2724 ordered_extent->len - 1, NULL, GFP_NOFS);
2725
2726 /*
2727 * If the ordered extent had an IOERR or something else went
2728 * wrong we need to return the space for this ordered extent
2729 * back to the allocator.
2730 */
2731 if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2732 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
2733 btrfs_free_reserved_extent(root, ordered_extent->start,
2734 ordered_extent->disk_len);
2735 }
2736
2737
2738 /*
2739 * This needs to be done to make sure anybody waiting knows we are done
2740 * updating everything for this ordered extent.
2741 */
2742 btrfs_remove_ordered_extent(inode, ordered_extent);
2743
2744 /* for snapshot-aware defrag */
2745 if (new)
2746 relink_file_extents(new);
2747
2748 /* once for us */
2749 btrfs_put_ordered_extent(ordered_extent);
2750 /* once for the tree */
2751 btrfs_put_ordered_extent(ordered_extent);
2752
2753 return ret;
2754 }
2755
2756 static void finish_ordered_fn(struct btrfs_work *work)
2757 {
2758 struct btrfs_ordered_extent *ordered_extent;
2759 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
2760 btrfs_finish_ordered_io(ordered_extent);
2761 }
2762
2763 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
2764 struct extent_state *state, int uptodate)
2765 {
2766 struct inode *inode = page->mapping->host;
2767 struct btrfs_root *root = BTRFS_I(inode)->root;
2768 struct btrfs_ordered_extent *ordered_extent = NULL;
2769 struct btrfs_workers *workers;
2770
2771 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
2772
2773 ClearPagePrivate2(page);
2774 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
2775 end - start + 1, uptodate))
2776 return 0;
2777
2778 ordered_extent->work.func = finish_ordered_fn;
2779 ordered_extent->work.flags = 0;
2780
2781 if (btrfs_is_free_space_inode(inode))
2782 workers = &root->fs_info->endio_freespace_worker;
2783 else
2784 workers = &root->fs_info->endio_write_workers;
2785 btrfs_queue_worker(workers, &ordered_extent->work);
2786
2787 return 0;
2788 }
2789
2790 /*
2791 * when reads are done, we need to check csums to verify the data is correct
2792 * if there's a match, we allow the bio to finish. If not, the code in
2793 * extent_io.c will try to find good copies for us.
2794 */
2795 static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
2796 struct extent_state *state, int mirror)
2797 {
2798 size_t offset = start - page_offset(page);
2799 struct inode *inode = page->mapping->host;
2800 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2801 char *kaddr;
2802 u64 private = ~(u32)0;
2803 int ret;
2804 struct btrfs_root *root = BTRFS_I(inode)->root;
2805 u32 csum = ~(u32)0;
2806 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
2807 DEFAULT_RATELIMIT_BURST);
2808
2809 if (PageChecked(page)) {
2810 ClearPageChecked(page);
2811 goto good;
2812 }
2813
2814 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
2815 goto good;
2816
2817 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
2818 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
2819 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
2820 GFP_NOFS);
2821 return 0;
2822 }
2823
2824 if (state && state->start == start) {
2825 private = state->private;
2826 ret = 0;
2827 } else {
2828 ret = get_state_private(io_tree, start, &private);
2829 }
2830 kaddr = kmap_atomic(page);
2831 if (ret)
2832 goto zeroit;
2833
2834 csum = btrfs_csum_data(kaddr + offset, csum, end - start + 1);
2835 btrfs_csum_final(csum, (char *)&csum);
2836 if (csum != private)
2837 goto zeroit;
2838
2839 kunmap_atomic(kaddr);
2840 good:
2841 return 0;
2842
2843 zeroit:
2844 if (__ratelimit(&_rs))
2845 btrfs_info(root->fs_info, "csum failed ino %llu off %llu csum %u private %llu",
2846 (unsigned long long)btrfs_ino(page->mapping->host),
2847 (unsigned long long)start, csum,
2848 (unsigned long long)private);
2849 memset(kaddr + offset, 1, end - start + 1);
2850 flush_dcache_page(page);
2851 kunmap_atomic(kaddr);
2852 if (private == 0)
2853 return 0;
2854 return -EIO;
2855 }
2856
2857 struct delayed_iput {
2858 struct list_head list;
2859 struct inode *inode;
2860 };
2861
2862 /* JDM: If this is fs-wide, why can't we add a pointer to
2863 * btrfs_inode instead and avoid the allocation? */
2864 void btrfs_add_delayed_iput(struct inode *inode)
2865 {
2866 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2867 struct delayed_iput *delayed;
2868
2869 if (atomic_add_unless(&inode->i_count, -1, 1))
2870 return;
2871
2872 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
2873 delayed->inode = inode;
2874
2875 spin_lock(&fs_info->delayed_iput_lock);
2876 list_add_tail(&delayed->list, &fs_info->delayed_iputs);
2877 spin_unlock(&fs_info->delayed_iput_lock);
2878 }
2879
2880 void btrfs_run_delayed_iputs(struct btrfs_root *root)
2881 {
2882 LIST_HEAD(list);
2883 struct btrfs_fs_info *fs_info = root->fs_info;
2884 struct delayed_iput *delayed;
2885 int empty;
2886
2887 spin_lock(&fs_info->delayed_iput_lock);
2888 empty = list_empty(&fs_info->delayed_iputs);
2889 spin_unlock(&fs_info->delayed_iput_lock);
2890 if (empty)
2891 return;
2892
2893 spin_lock(&fs_info->delayed_iput_lock);
2894 list_splice_init(&fs_info->delayed_iputs, &list);
2895 spin_unlock(&fs_info->delayed_iput_lock);
2896
2897 while (!list_empty(&list)) {
2898 delayed = list_entry(list.next, struct delayed_iput, list);
2899 list_del(&delayed->list);
2900 iput(delayed->inode);
2901 kfree(delayed);
2902 }
2903 }
2904
2905 /*
2906 * This is called in transaction commit time. If there are no orphan
2907 * files in the subvolume, it removes orphan item and frees block_rsv
2908 * structure.
2909 */
2910 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
2911 struct btrfs_root *root)
2912 {
2913 struct btrfs_block_rsv *block_rsv;
2914 int ret;
2915
2916 if (atomic_read(&root->orphan_inodes) ||
2917 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
2918 return;
2919
2920 spin_lock(&root->orphan_lock);
2921 if (atomic_read(&root->orphan_inodes)) {
2922 spin_unlock(&root->orphan_lock);
2923 return;
2924 }
2925
2926 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
2927 spin_unlock(&root->orphan_lock);
2928 return;
2929 }
2930
2931 block_rsv = root->orphan_block_rsv;
2932 root->orphan_block_rsv = NULL;
2933 spin_unlock(&root->orphan_lock);
2934
2935 if (root->orphan_item_inserted &&
2936 btrfs_root_refs(&root->root_item) > 0) {
2937 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
2938 root->root_key.objectid);
2939 BUG_ON(ret);
2940 root->orphan_item_inserted = 0;
2941 }
2942
2943 if (block_rsv) {
2944 WARN_ON(block_rsv->size > 0);
2945 btrfs_free_block_rsv(root, block_rsv);
2946 }
2947 }
2948
2949 /*
2950 * This creates an orphan entry for the given inode in case something goes
2951 * wrong in the middle of an unlink/truncate.
2952 *
2953 * NOTE: caller of this function should reserve 5 units of metadata for
2954 * this function.
2955 */
2956 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
2957 {
2958 struct btrfs_root *root = BTRFS_I(inode)->root;
2959 struct btrfs_block_rsv *block_rsv = NULL;
2960 int reserve = 0;
2961 int insert = 0;
2962 int ret;
2963
2964 if (!root->orphan_block_rsv) {
2965 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
2966 if (!block_rsv)
2967 return -ENOMEM;
2968 }
2969
2970 spin_lock(&root->orphan_lock);
2971 if (!root->orphan_block_rsv) {
2972 root->orphan_block_rsv = block_rsv;
2973 } else if (block_rsv) {
2974 btrfs_free_block_rsv(root, block_rsv);
2975 block_rsv = NULL;
2976 }
2977
2978 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
2979 &BTRFS_I(inode)->runtime_flags)) {
2980 #if 0
2981 /*
2982 * For proper ENOSPC handling, we should do orphan
2983 * cleanup when mounting. But this introduces backward
2984 * compatibility issue.
2985 */
2986 if (!xchg(&root->orphan_item_inserted, 1))
2987 insert = 2;
2988 else
2989 insert = 1;
2990 #endif
2991 insert = 1;
2992 atomic_inc(&root->orphan_inodes);
2993 }
2994
2995 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
2996 &BTRFS_I(inode)->runtime_flags))
2997 reserve = 1;
2998 spin_unlock(&root->orphan_lock);
2999
3000 /* grab metadata reservation from transaction handle */
3001 if (reserve) {
3002 ret = btrfs_orphan_reserve_metadata(trans, inode);
3003 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
3004 }
3005
3006 /* insert an orphan item to track this unlinked/truncated file */
3007 if (insert >= 1) {
3008 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3009 if (ret && ret != -EEXIST) {
3010 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3011 &BTRFS_I(inode)->runtime_flags);
3012 btrfs_abort_transaction(trans, root, ret);
3013 return ret;
3014 }
3015 ret = 0;
3016 }
3017
3018 /* insert an orphan item to track subvolume contains orphan files */
3019 if (insert >= 2) {
3020 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
3021 root->root_key.objectid);
3022 if (ret && ret != -EEXIST) {
3023 btrfs_abort_transaction(trans, root, ret);
3024 return ret;
3025 }
3026 }
3027 return 0;
3028 }
3029
3030 /*
3031 * We have done the truncate/delete so we can go ahead and remove the orphan
3032 * item for this particular inode.
3033 */
3034 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3035 struct inode *inode)
3036 {
3037 struct btrfs_root *root = BTRFS_I(inode)->root;
3038 int delete_item = 0;
3039 int release_rsv = 0;
3040 int ret = 0;
3041
3042 spin_lock(&root->orphan_lock);
3043 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3044 &BTRFS_I(inode)->runtime_flags))
3045 delete_item = 1;
3046
3047 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3048 &BTRFS_I(inode)->runtime_flags))
3049 release_rsv = 1;
3050 spin_unlock(&root->orphan_lock);
3051
3052 if (trans && delete_item) {
3053 ret = btrfs_del_orphan_item(trans, root, btrfs_ino(inode));
3054 BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */
3055 }
3056
3057 if (release_rsv) {
3058 btrfs_orphan_release_metadata(inode);
3059 atomic_dec(&root->orphan_inodes);
3060 }
3061
3062 return 0;
3063 }
3064
3065 /*
3066 * this cleans up any orphans that may be left on the list from the last use
3067 * of this root.
3068 */
3069 int btrfs_orphan_cleanup(struct btrfs_root *root)
3070 {
3071 struct btrfs_path *path;
3072 struct extent_buffer *leaf;
3073 struct btrfs_key key, found_key;
3074 struct btrfs_trans_handle *trans;
3075 struct inode *inode;
3076 u64 last_objectid = 0;
3077 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3078
3079 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3080 return 0;
3081
3082 path = btrfs_alloc_path();
3083 if (!path) {
3084 ret = -ENOMEM;
3085 goto out;
3086 }
3087 path->reada = -1;
3088
3089 key.objectid = BTRFS_ORPHAN_OBJECTID;
3090 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
3091 key.offset = (u64)-1;
3092
3093 while (1) {
3094 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3095 if (ret < 0)
3096 goto out;
3097
3098 /*
3099 * if ret == 0 means we found what we were searching for, which
3100 * is weird, but possible, so only screw with path if we didn't
3101 * find the key and see if we have stuff that matches
3102 */
3103 if (ret > 0) {
3104 ret = 0;
3105 if (path->slots[0] == 0)
3106 break;
3107 path->slots[0]--;
3108 }
3109
3110 /* pull out the item */
3111 leaf = path->nodes[0];
3112 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3113
3114 /* make sure the item matches what we want */
3115 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3116 break;
3117 if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
3118 break;
3119
3120 /* release the path since we're done with it */
3121 btrfs_release_path(path);
3122
3123 /*
3124 * this is where we are basically btrfs_lookup, without the
3125 * crossing root thing. we store the inode number in the
3126 * offset of the orphan item.
3127 */
3128
3129 if (found_key.offset == last_objectid) {
3130 btrfs_err(root->fs_info,
3131 "Error removing orphan entry, stopping orphan cleanup");
3132 ret = -EINVAL;
3133 goto out;
3134 }
3135
3136 last_objectid = found_key.offset;
3137
3138 found_key.objectid = found_key.offset;
3139 found_key.type = BTRFS_INODE_ITEM_KEY;
3140 found_key.offset = 0;
3141 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3142 ret = PTR_RET(inode);
3143 if (ret && ret != -ESTALE)
3144 goto out;
3145
3146 if (ret == -ESTALE && root == root->fs_info->tree_root) {
3147 struct btrfs_root *dead_root;
3148 struct btrfs_fs_info *fs_info = root->fs_info;
3149 int is_dead_root = 0;
3150
3151 /*
3152 * this is an orphan in the tree root. Currently these
3153 * could come from 2 sources:
3154 * a) a snapshot deletion in progress
3155 * b) a free space cache inode
3156 * We need to distinguish those two, as the snapshot
3157 * orphan must not get deleted.
3158 * find_dead_roots already ran before us, so if this
3159 * is a snapshot deletion, we should find the root
3160 * in the dead_roots list
3161 */
3162 spin_lock(&fs_info->trans_lock);
3163 list_for_each_entry(dead_root, &fs_info->dead_roots,
3164 root_list) {
3165 if (dead_root->root_key.objectid ==
3166 found_key.objectid) {
3167 is_dead_root = 1;
3168 break;
3169 }
3170 }
3171 spin_unlock(&fs_info->trans_lock);
3172 if (is_dead_root) {
3173 /* prevent this orphan from being found again */
3174 key.offset = found_key.objectid - 1;
3175 continue;
3176 }
3177 }
3178 /*
3179 * Inode is already gone but the orphan item is still there,
3180 * kill the orphan item.
3181 */
3182 if (ret == -ESTALE) {
3183 trans = btrfs_start_transaction(root, 1);
3184 if (IS_ERR(trans)) {
3185 ret = PTR_ERR(trans);
3186 goto out;
3187 }
3188 btrfs_debug(root->fs_info, "auto deleting %Lu",
3189 found_key.objectid);
3190 ret = btrfs_del_orphan_item(trans, root,
3191 found_key.objectid);
3192 BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */
3193 btrfs_end_transaction(trans, root);
3194 continue;
3195 }
3196
3197 /*
3198 * add this inode to the orphan list so btrfs_orphan_del does
3199 * the proper thing when we hit it
3200 */
3201 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3202 &BTRFS_I(inode)->runtime_flags);
3203 atomic_inc(&root->orphan_inodes);
3204
3205 /* if we have links, this was a truncate, lets do that */
3206 if (inode->i_nlink) {
3207 if (!S_ISREG(inode->i_mode)) {
3208 WARN_ON(1);
3209 iput(inode);
3210 continue;
3211 }
3212 nr_truncate++;
3213
3214 /* 1 for the orphan item deletion. */
3215 trans = btrfs_start_transaction(root, 1);
3216 if (IS_ERR(trans)) {
3217 ret = PTR_ERR(trans);
3218 goto out;
3219 }
3220 ret = btrfs_orphan_add(trans, inode);
3221 btrfs_end_transaction(trans, root);
3222 if (ret)
3223 goto out;
3224
3225 ret = btrfs_truncate(inode);
3226 if (ret)
3227 btrfs_orphan_del(NULL, inode);
3228 } else {
3229 nr_unlink++;
3230 }
3231
3232 /* this will do delete_inode and everything for us */
3233 iput(inode);
3234 if (ret)
3235 goto out;
3236 }
3237 /* release the path since we're done with it */
3238 btrfs_release_path(path);
3239
3240 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3241
3242 if (root->orphan_block_rsv)
3243 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3244 (u64)-1);
3245
3246 if (root->orphan_block_rsv || root->orphan_item_inserted) {
3247 trans = btrfs_join_transaction(root);
3248 if (!IS_ERR(trans))
3249 btrfs_end_transaction(trans, root);
3250 }
3251
3252 if (nr_unlink)
3253 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3254 if (nr_truncate)
3255 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3256
3257 out:
3258 if (ret)
3259 btrfs_crit(root->fs_info,
3260 "could not do orphan cleanup %d", ret);
3261 btrfs_free_path(path);
3262 return ret;
3263 }
3264
3265 /*
3266 * very simple check to peek ahead in the leaf looking for xattrs. If we
3267 * don't find any xattrs, we know there can't be any acls.
3268 *
3269 * slot is the slot the inode is in, objectid is the objectid of the inode
3270 */
3271 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3272 int slot, u64 objectid)
3273 {
3274 u32 nritems = btrfs_header_nritems(leaf);
3275 struct btrfs_key found_key;
3276 int scanned = 0;
3277
3278 slot++;
3279 while (slot < nritems) {
3280 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3281
3282 /* we found a different objectid, there must not be acls */
3283 if (found_key.objectid != objectid)
3284 return 0;
3285
3286 /* we found an xattr, assume we've got an acl */
3287 if (found_key.type == BTRFS_XATTR_ITEM_KEY)
3288 return 1;
3289
3290 /*
3291 * we found a key greater than an xattr key, there can't
3292 * be any acls later on
3293 */
3294 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3295 return 0;
3296
3297 slot++;
3298 scanned++;
3299
3300 /*
3301 * it goes inode, inode backrefs, xattrs, extents,
3302 * so if there are a ton of hard links to an inode there can
3303 * be a lot of backrefs. Don't waste time searching too hard,
3304 * this is just an optimization
3305 */
3306 if (scanned >= 8)
3307 break;
3308 }
3309 /* we hit the end of the leaf before we found an xattr or
3310 * something larger than an xattr. We have to assume the inode
3311 * has acls
3312 */
3313 return 1;
3314 }
3315
3316 /*
3317 * read an inode from the btree into the in-memory inode
3318 */
3319 static void btrfs_read_locked_inode(struct inode *inode)
3320 {
3321 struct btrfs_path *path;
3322 struct extent_buffer *leaf;
3323 struct btrfs_inode_item *inode_item;
3324 struct btrfs_timespec *tspec;
3325 struct btrfs_root *root = BTRFS_I(inode)->root;
3326 struct btrfs_key location;
3327 int maybe_acls;
3328 u32 rdev;
3329 int ret;
3330 bool filled = false;
3331
3332 ret = btrfs_fill_inode(inode, &rdev);
3333 if (!ret)
3334 filled = true;
3335
3336 path = btrfs_alloc_path();
3337 if (!path)
3338 goto make_bad;
3339
3340 path->leave_spinning = 1;
3341 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3342
3343 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3344 if (ret)
3345 goto make_bad;
3346
3347 leaf = path->nodes[0];
3348
3349 if (filled)
3350 goto cache_acl;
3351
3352 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3353 struct btrfs_inode_item);
3354 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3355 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3356 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3357 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3358 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3359
3360 tspec = btrfs_inode_atime(inode_item);
3361 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3362 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3363
3364 tspec = btrfs_inode_mtime(inode_item);
3365 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3366 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3367
3368 tspec = btrfs_inode_ctime(inode_item);
3369 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3370 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3371
3372 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3373 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3374 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3375
3376 /*
3377 * If we were modified in the current generation and evicted from memory
3378 * and then re-read we need to do a full sync since we don't have any
3379 * idea about which extents were modified before we were evicted from
3380 * cache.
3381 */
3382 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3383 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3384 &BTRFS_I(inode)->runtime_flags);
3385
3386 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3387 inode->i_generation = BTRFS_I(inode)->generation;
3388 inode->i_rdev = 0;
3389 rdev = btrfs_inode_rdev(leaf, inode_item);
3390
3391 BTRFS_I(inode)->index_cnt = (u64)-1;
3392 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3393 cache_acl:
3394 /*
3395 * try to precache a NULL acl entry for files that don't have
3396 * any xattrs or acls
3397 */
3398 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3399 btrfs_ino(inode));
3400 if (!maybe_acls)
3401 cache_no_acl(inode);
3402
3403 btrfs_free_path(path);
3404
3405 switch (inode->i_mode & S_IFMT) {
3406 case S_IFREG:
3407 inode->i_mapping->a_ops = &btrfs_aops;
3408 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3409 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3410 inode->i_fop = &btrfs_file_operations;
3411 inode->i_op = &btrfs_file_inode_operations;
3412 break;
3413 case S_IFDIR:
3414 inode->i_fop = &btrfs_dir_file_operations;
3415 if (root == root->fs_info->tree_root)
3416 inode->i_op = &btrfs_dir_ro_inode_operations;
3417 else
3418 inode->i_op = &btrfs_dir_inode_operations;
3419 break;
3420 case S_IFLNK:
3421 inode->i_op = &btrfs_symlink_inode_operations;
3422 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3423 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3424 break;
3425 default:
3426 inode->i_op = &btrfs_special_inode_operations;
3427 init_special_inode(inode, inode->i_mode, rdev);
3428 break;
3429 }
3430
3431 btrfs_update_iflags(inode);
3432 return;
3433
3434 make_bad:
3435 btrfs_free_path(path);
3436 make_bad_inode(inode);
3437 }
3438
3439 /*
3440 * given a leaf and an inode, copy the inode fields into the leaf
3441 */
3442 static void fill_inode_item(struct btrfs_trans_handle *trans,
3443 struct extent_buffer *leaf,
3444 struct btrfs_inode_item *item,
3445 struct inode *inode)
3446 {
3447 struct btrfs_map_token token;
3448
3449 btrfs_init_map_token(&token);
3450
3451 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3452 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3453 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3454 &token);
3455 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3456 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3457
3458 btrfs_set_token_timespec_sec(leaf, btrfs_inode_atime(item),
3459 inode->i_atime.tv_sec, &token);
3460 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_atime(item),
3461 inode->i_atime.tv_nsec, &token);
3462
3463 btrfs_set_token_timespec_sec(leaf, btrfs_inode_mtime(item),
3464 inode->i_mtime.tv_sec, &token);
3465 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_mtime(item),
3466 inode->i_mtime.tv_nsec, &token);
3467
3468 btrfs_set_token_timespec_sec(leaf, btrfs_inode_ctime(item),
3469 inode->i_ctime.tv_sec, &token);
3470 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_ctime(item),
3471 inode->i_ctime.tv_nsec, &token);
3472
3473 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3474 &token);
3475 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3476 &token);
3477 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3478 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3479 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3480 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3481 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3482 }
3483
3484 /*
3485 * copy everything in the in-memory inode into the btree.
3486 */
3487 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3488 struct btrfs_root *root, struct inode *inode)
3489 {
3490 struct btrfs_inode_item *inode_item;
3491 struct btrfs_path *path;
3492 struct extent_buffer *leaf;
3493 int ret;
3494
3495 path = btrfs_alloc_path();
3496 if (!path)
3497 return -ENOMEM;
3498
3499 path->leave_spinning = 1;
3500 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3501 1);
3502 if (ret) {
3503 if (ret > 0)
3504 ret = -ENOENT;
3505 goto failed;
3506 }
3507
3508 btrfs_unlock_up_safe(path, 1);
3509 leaf = path->nodes[0];
3510 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3511 struct btrfs_inode_item);
3512
3513 fill_inode_item(trans, leaf, inode_item, inode);
3514 btrfs_mark_buffer_dirty(leaf);
3515 btrfs_set_inode_last_trans(trans, inode);
3516 ret = 0;
3517 failed:
3518 btrfs_free_path(path);
3519 return ret;
3520 }
3521
3522 /*
3523 * copy everything in the in-memory inode into the btree.
3524 */
3525 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3526 struct btrfs_root *root, struct inode *inode)
3527 {
3528 int ret;
3529
3530 /*
3531 * If the inode is a free space inode, we can deadlock during commit
3532 * if we put it into the delayed code.
3533 *
3534 * The data relocation inode should also be directly updated
3535 * without delay
3536 */
3537 if (!btrfs_is_free_space_inode(inode)
3538 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) {
3539 btrfs_update_root_times(trans, root);
3540
3541 ret = btrfs_delayed_update_inode(trans, root, inode);
3542 if (!ret)
3543 btrfs_set_inode_last_trans(trans, inode);
3544 return ret;
3545 }
3546
3547 return btrfs_update_inode_item(trans, root, inode);
3548 }
3549
3550 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3551 struct btrfs_root *root,
3552 struct inode *inode)
3553 {
3554 int ret;
3555
3556 ret = btrfs_update_inode(trans, root, inode);
3557 if (ret == -ENOSPC)
3558 return btrfs_update_inode_item(trans, root, inode);
3559 return ret;
3560 }
3561
3562 /*
3563 * unlink helper that gets used here in inode.c and in the tree logging
3564 * recovery code. It remove a link in a directory with a given name, and
3565 * also drops the back refs in the inode to the directory
3566 */
3567 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3568 struct btrfs_root *root,
3569 struct inode *dir, struct inode *inode,
3570 const char *name, int name_len)
3571 {
3572 struct btrfs_path *path;
3573 int ret = 0;
3574 struct extent_buffer *leaf;
3575 struct btrfs_dir_item *di;
3576 struct btrfs_key key;
3577 u64 index;
3578 u64 ino = btrfs_ino(inode);
3579 u64 dir_ino = btrfs_ino(dir);
3580
3581 path = btrfs_alloc_path();
3582 if (!path) {
3583 ret = -ENOMEM;
3584 goto out;
3585 }
3586
3587 path->leave_spinning = 1;
3588 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3589 name, name_len, -1);
3590 if (IS_ERR(di)) {
3591 ret = PTR_ERR(di);
3592 goto err;
3593 }
3594 if (!di) {
3595 ret = -ENOENT;
3596 goto err;
3597 }
3598 leaf = path->nodes[0];
3599 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3600 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3601 if (ret)
3602 goto err;
3603 btrfs_release_path(path);
3604
3605 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
3606 dir_ino, &index);
3607 if (ret) {
3608 btrfs_info(root->fs_info,
3609 "failed to delete reference to %.*s, inode %llu parent %llu",
3610 name_len, name,
3611 (unsigned long long)ino, (unsigned long long)dir_ino);
3612 btrfs_abort_transaction(trans, root, ret);
3613 goto err;
3614 }
3615
3616 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3617 if (ret) {
3618 btrfs_abort_transaction(trans, root, ret);
3619 goto err;
3620 }
3621
3622 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
3623 inode, dir_ino);
3624 if (ret != 0 && ret != -ENOENT) {
3625 btrfs_abort_transaction(trans, root, ret);
3626 goto err;
3627 }
3628
3629 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
3630 dir, index);
3631 if (ret == -ENOENT)
3632 ret = 0;
3633 else if (ret)
3634 btrfs_abort_transaction(trans, root, ret);
3635 err:
3636 btrfs_free_path(path);
3637 if (ret)
3638 goto out;
3639
3640 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3641 inode_inc_iversion(inode);
3642 inode_inc_iversion(dir);
3643 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3644 ret = btrfs_update_inode(trans, root, dir);
3645 out:
3646 return ret;
3647 }
3648
3649 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3650 struct btrfs_root *root,
3651 struct inode *dir, struct inode *inode,
3652 const char *name, int name_len)
3653 {
3654 int ret;
3655 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
3656 if (!ret) {
3657 btrfs_drop_nlink(inode);
3658 ret = btrfs_update_inode(trans, root, inode);
3659 }
3660 return ret;
3661 }
3662
3663
3664 /* helper to check if there is any shared block in the path */
3665 static int check_path_shared(struct btrfs_root *root,
3666 struct btrfs_path *path)
3667 {
3668 struct extent_buffer *eb;
3669 int level;
3670 u64 refs = 1;
3671
3672 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
3673 int ret;
3674
3675 if (!path->nodes[level])
3676 break;
3677 eb = path->nodes[level];
3678 if (!btrfs_block_can_be_shared(root, eb))
3679 continue;
3680 ret = btrfs_lookup_extent_info(NULL, root, eb->start, level, 1,
3681 &refs, NULL);
3682 if (refs > 1)
3683 return 1;
3684 }
3685 return 0;
3686 }
3687
3688 /*
3689 * helper to start transaction for unlink and rmdir.
3690 *
3691 * unlink and rmdir are special in btrfs, they do not always free space.
3692 * so in enospc case, we should make sure they will free space before
3693 * allowing them to use the global metadata reservation.
3694 */
3695 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
3696 struct dentry *dentry)
3697 {
3698 struct btrfs_trans_handle *trans;
3699 struct btrfs_root *root = BTRFS_I(dir)->root;
3700 struct btrfs_path *path;
3701 struct btrfs_dir_item *di;
3702 struct inode *inode = dentry->d_inode;
3703 u64 index;
3704 int check_link = 1;
3705 int err = -ENOSPC;
3706 int ret;
3707 u64 ino = btrfs_ino(inode);
3708 u64 dir_ino = btrfs_ino(dir);
3709
3710 /*
3711 * 1 for the possible orphan item
3712 * 1 for the dir item
3713 * 1 for the dir index
3714 * 1 for the inode ref
3715 * 1 for the inode
3716 */
3717 trans = btrfs_start_transaction(root, 5);
3718 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
3719 return trans;
3720
3721 if (ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
3722 return ERR_PTR(-ENOSPC);
3723
3724 /* check if there is someone else holds reference */
3725 if (S_ISDIR(inode->i_mode) && atomic_read(&inode->i_count) > 1)
3726 return ERR_PTR(-ENOSPC);
3727
3728 if (atomic_read(&inode->i_count) > 2)
3729 return ERR_PTR(-ENOSPC);
3730
3731 if (xchg(&root->fs_info->enospc_unlink, 1))
3732 return ERR_PTR(-ENOSPC);
3733
3734 path = btrfs_alloc_path();
3735 if (!path) {
3736 root->fs_info->enospc_unlink = 0;
3737 return ERR_PTR(-ENOMEM);
3738 }
3739
3740 /* 1 for the orphan item */
3741 trans = btrfs_start_transaction(root, 1);
3742 if (IS_ERR(trans)) {
3743 btrfs_free_path(path);
3744 root->fs_info->enospc_unlink = 0;
3745 return trans;
3746 }
3747
3748 path->skip_locking = 1;
3749 path->search_commit_root = 1;
3750
3751 ret = btrfs_lookup_inode(trans, root, path,
3752 &BTRFS_I(dir)->location, 0);
3753 if (ret < 0) {
3754 err = ret;
3755 goto out;
3756 }
3757 if (ret == 0) {
3758 if (check_path_shared(root, path))
3759 goto out;
3760 } else {
3761 check_link = 0;
3762 }
3763 btrfs_release_path(path);
3764
3765 ret = btrfs_lookup_inode(trans, root, path,
3766 &BTRFS_I(inode)->location, 0);
3767 if (ret < 0) {
3768 err = ret;
3769 goto out;
3770 }
3771 if (ret == 0) {
3772 if (check_path_shared(root, path))
3773 goto out;
3774 } else {
3775 check_link = 0;
3776 }
3777 btrfs_release_path(path);
3778
3779 if (ret == 0 && S_ISREG(inode->i_mode)) {
3780 ret = btrfs_lookup_file_extent(trans, root, path,
3781 ino, (u64)-1, 0);
3782 if (ret < 0) {
3783 err = ret;
3784 goto out;
3785 }
3786 BUG_ON(ret == 0); /* Corruption */
3787 if (check_path_shared(root, path))
3788 goto out;
3789 btrfs_release_path(path);
3790 }
3791
3792 if (!check_link) {
3793 err = 0;
3794 goto out;
3795 }
3796
3797 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3798 dentry->d_name.name, dentry->d_name.len, 0);
3799 if (IS_ERR(di)) {
3800 err = PTR_ERR(di);
3801 goto out;
3802 }
3803 if (di) {
3804 if (check_path_shared(root, path))
3805 goto out;
3806 } else {
3807 err = 0;
3808 goto out;
3809 }
3810 btrfs_release_path(path);
3811
3812 ret = btrfs_get_inode_ref_index(trans, root, path, dentry->d_name.name,
3813 dentry->d_name.len, ino, dir_ino, 0,
3814 &index);
3815 if (ret) {
3816 err = ret;
3817 goto out;
3818 }
3819
3820 if (check_path_shared(root, path))
3821 goto out;
3822
3823 btrfs_release_path(path);
3824
3825 /*
3826 * This is a commit root search, if we can lookup inode item and other
3827 * relative items in the commit root, it means the transaction of
3828 * dir/file creation has been committed, and the dir index item that we
3829 * delay to insert has also been inserted into the commit root. So
3830 * we needn't worry about the delayed insertion of the dir index item
3831 * here.
3832 */
3833 di = btrfs_lookup_dir_index_item(trans, root, path, dir_ino, index,
3834 dentry->d_name.name, dentry->d_name.len, 0);
3835 if (IS_ERR(di)) {
3836 err = PTR_ERR(di);
3837 goto out;
3838 }
3839 BUG_ON(ret == -ENOENT);
3840 if (check_path_shared(root, path))
3841 goto out;
3842
3843 err = 0;
3844 out:
3845 btrfs_free_path(path);
3846 /* Migrate the orphan reservation over */
3847 if (!err)
3848 err = btrfs_block_rsv_migrate(trans->block_rsv,
3849 &root->fs_info->global_block_rsv,
3850 trans->bytes_reserved);
3851
3852 if (err) {
3853 btrfs_end_transaction(trans, root);
3854 root->fs_info->enospc_unlink = 0;
3855 return ERR_PTR(err);
3856 }
3857
3858 trans->block_rsv = &root->fs_info->global_block_rsv;
3859 return trans;
3860 }
3861
3862 static void __unlink_end_trans(struct btrfs_trans_handle *trans,
3863 struct btrfs_root *root)
3864 {
3865 if (trans->block_rsv->type == BTRFS_BLOCK_RSV_GLOBAL) {
3866 btrfs_block_rsv_release(root, trans->block_rsv,
3867 trans->bytes_reserved);
3868 trans->block_rsv = &root->fs_info->trans_block_rsv;
3869 BUG_ON(!root->fs_info->enospc_unlink);
3870 root->fs_info->enospc_unlink = 0;
3871 }
3872 btrfs_end_transaction(trans, root);
3873 }
3874
3875 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
3876 {
3877 struct btrfs_root *root = BTRFS_I(dir)->root;
3878 struct btrfs_trans_handle *trans;
3879 struct inode *inode = dentry->d_inode;
3880 int ret;
3881
3882 trans = __unlink_start_trans(dir, dentry);
3883 if (IS_ERR(trans))
3884 return PTR_ERR(trans);
3885
3886 btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0);
3887
3888 ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3889 dentry->d_name.name, dentry->d_name.len);
3890 if (ret)
3891 goto out;
3892
3893 if (inode->i_nlink == 0) {
3894 ret = btrfs_orphan_add(trans, inode);
3895 if (ret)
3896 goto out;
3897 }
3898
3899 out:
3900 __unlink_end_trans(trans, root);
3901 btrfs_btree_balance_dirty(root);
3902 return ret;
3903 }
3904
3905 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
3906 struct btrfs_root *root,
3907 struct inode *dir, u64 objectid,
3908 const char *name, int name_len)
3909 {
3910 struct btrfs_path *path;
3911 struct extent_buffer *leaf;
3912 struct btrfs_dir_item *di;
3913 struct btrfs_key key;
3914 u64 index;
3915 int ret;
3916 u64 dir_ino = btrfs_ino(dir);
3917
3918 path = btrfs_alloc_path();
3919 if (!path)
3920 return -ENOMEM;
3921
3922 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3923 name, name_len, -1);
3924 if (IS_ERR_OR_NULL(di)) {
3925 if (!di)
3926 ret = -ENOENT;
3927 else
3928 ret = PTR_ERR(di);
3929 goto out;
3930 }
3931
3932 leaf = path->nodes[0];
3933 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3934 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
3935 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3936 if (ret) {
3937 btrfs_abort_transaction(trans, root, ret);
3938 goto out;
3939 }
3940 btrfs_release_path(path);
3941
3942 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
3943 objectid, root->root_key.objectid,
3944 dir_ino, &index, name, name_len);
3945 if (ret < 0) {
3946 if (ret != -ENOENT) {
3947 btrfs_abort_transaction(trans, root, ret);
3948 goto out;
3949 }
3950 di = btrfs_search_dir_index_item(root, path, dir_ino,
3951 name, name_len);
3952 if (IS_ERR_OR_NULL(di)) {
3953 if (!di)
3954 ret = -ENOENT;
3955 else
3956 ret = PTR_ERR(di);
3957 btrfs_abort_transaction(trans, root, ret);
3958 goto out;
3959 }
3960
3961 leaf = path->nodes[0];
3962 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3963 btrfs_release_path(path);
3964 index = key.offset;
3965 }
3966 btrfs_release_path(path);
3967
3968 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3969 if (ret) {
3970 btrfs_abort_transaction(trans, root, ret);
3971 goto out;
3972 }
3973
3974 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3975 inode_inc_iversion(dir);
3976 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3977 ret = btrfs_update_inode_fallback(trans, root, dir);
3978 if (ret)
3979 btrfs_abort_transaction(trans, root, ret);
3980 out:
3981 btrfs_free_path(path);
3982 return ret;
3983 }
3984
3985 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
3986 {
3987 struct inode *inode = dentry->d_inode;
3988 int err = 0;
3989 struct btrfs_root *root = BTRFS_I(dir)->root;
3990 struct btrfs_trans_handle *trans;
3991
3992 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
3993 return -ENOTEMPTY;
3994 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
3995 return -EPERM;
3996
3997 trans = __unlink_start_trans(dir, dentry);
3998 if (IS_ERR(trans))
3999 return PTR_ERR(trans);
4000
4001 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4002 err = btrfs_unlink_subvol(trans, root, dir,
4003 BTRFS_I(inode)->location.objectid,
4004 dentry->d_name.name,
4005 dentry->d_name.len);
4006 goto out;
4007 }
4008
4009 err = btrfs_orphan_add(trans, inode);
4010 if (err)
4011 goto out;
4012
4013 /* now the directory is empty */
4014 err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
4015 dentry->d_name.name, dentry->d_name.len);
4016 if (!err)
4017 btrfs_i_size_write(inode, 0);
4018 out:
4019 __unlink_end_trans(trans, root);
4020 btrfs_btree_balance_dirty(root);
4021
4022 return err;
4023 }
4024
4025 /*
4026 * this can truncate away extent items, csum items and directory items.
4027 * It starts at a high offset and removes keys until it can't find
4028 * any higher than new_size
4029 *
4030 * csum items that cross the new i_size are truncated to the new size
4031 * as well.
4032 *
4033 * min_type is the minimum key type to truncate down to. If set to 0, this
4034 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4035 */
4036 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4037 struct btrfs_root *root,
4038 struct inode *inode,
4039 u64 new_size, u32 min_type)
4040 {
4041 struct btrfs_path *path;
4042 struct extent_buffer *leaf;
4043 struct btrfs_file_extent_item *fi;
4044 struct btrfs_key key;
4045 struct btrfs_key found_key;
4046 u64 extent_start = 0;
4047 u64 extent_num_bytes = 0;
4048 u64 extent_offset = 0;
4049 u64 item_end = 0;
4050 u32 found_type = (u8)-1;
4051 int found_extent;
4052 int del_item;
4053 int pending_del_nr = 0;
4054 int pending_del_slot = 0;
4055 int extent_type = -1;
4056 int ret;
4057 int err = 0;
4058 u64 ino = btrfs_ino(inode);
4059
4060 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4061
4062 path = btrfs_alloc_path();
4063 if (!path)
4064 return -ENOMEM;
4065 path->reada = -1;
4066
4067 /*
4068 * We want to drop from the next block forward in case this new size is
4069 * not block aligned since we will be keeping the last block of the
4070 * extent just the way it is.
4071 */
4072 if (root->ref_cows || root == root->fs_info->tree_root)
4073 btrfs_drop_extent_cache(inode, ALIGN(new_size,
4074 root->sectorsize), (u64)-1, 0);
4075
4076 /*
4077 * This function is also used to drop the items in the log tree before
4078 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4079 * it is used to drop the loged items. So we shouldn't kill the delayed
4080 * items.
4081 */
4082 if (min_type == 0 && root == BTRFS_I(inode)->root)
4083 btrfs_kill_delayed_inode_items(inode);
4084
4085 key.objectid = ino;
4086 key.offset = (u64)-1;
4087 key.type = (u8)-1;
4088
4089 search_again:
4090 path->leave_spinning = 1;
4091 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4092 if (ret < 0) {
4093 err = ret;
4094 goto out;
4095 }
4096
4097 if (ret > 0) {
4098 /* there are no items in the tree for us to truncate, we're
4099 * done
4100 */
4101 if (path->slots[0] == 0)
4102 goto out;
4103 path->slots[0]--;
4104 }
4105
4106 while (1) {
4107 fi = NULL;
4108 leaf = path->nodes[0];
4109 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4110 found_type = btrfs_key_type(&found_key);
4111
4112 if (found_key.objectid != ino)
4113 break;
4114
4115 if (found_type < min_type)
4116 break;
4117
4118 item_end = found_key.offset;
4119 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4120 fi = btrfs_item_ptr(leaf, path->slots[0],
4121 struct btrfs_file_extent_item);
4122 extent_type = btrfs_file_extent_type(leaf, fi);
4123 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4124 item_end +=
4125 btrfs_file_extent_num_bytes(leaf, fi);
4126 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4127 item_end += btrfs_file_extent_inline_len(leaf,
4128 fi);
4129 }
4130 item_end--;
4131 }
4132 if (found_type > min_type) {
4133 del_item = 1;
4134 } else {
4135 if (item_end < new_size)
4136 break;
4137 if (found_key.offset >= new_size)
4138 del_item = 1;
4139 else
4140 del_item = 0;
4141 }
4142 found_extent = 0;
4143 /* FIXME, shrink the extent if the ref count is only 1 */
4144 if (found_type != BTRFS_EXTENT_DATA_KEY)
4145 goto delete;
4146
4147 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4148 u64 num_dec;
4149 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4150 if (!del_item) {
4151 u64 orig_num_bytes =
4152 btrfs_file_extent_num_bytes(leaf, fi);
4153 extent_num_bytes = ALIGN(new_size -
4154 found_key.offset,
4155 root->sectorsize);
4156 btrfs_set_file_extent_num_bytes(leaf, fi,
4157 extent_num_bytes);
4158 num_dec = (orig_num_bytes -
4159 extent_num_bytes);
4160 if (root->ref_cows && extent_start != 0)
4161 inode_sub_bytes(inode, num_dec);
4162 btrfs_mark_buffer_dirty(leaf);
4163 } else {
4164 extent_num_bytes =
4165 btrfs_file_extent_disk_num_bytes(leaf,
4166 fi);
4167 extent_offset = found_key.offset -
4168 btrfs_file_extent_offset(leaf, fi);
4169
4170 /* FIXME blocksize != 4096 */
4171 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4172 if (extent_start != 0) {
4173 found_extent = 1;
4174 if (root->ref_cows)
4175 inode_sub_bytes(inode, num_dec);
4176 }
4177 }
4178 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4179 /*
4180 * we can't truncate inline items that have had
4181 * special encodings
4182 */
4183 if (!del_item &&
4184 btrfs_file_extent_compression(leaf, fi) == 0 &&
4185 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4186 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4187 u32 size = new_size - found_key.offset;
4188
4189 if (root->ref_cows) {
4190 inode_sub_bytes(inode, item_end + 1 -
4191 new_size);
4192 }
4193 size =
4194 btrfs_file_extent_calc_inline_size(size);
4195 btrfs_truncate_item(root, path, size, 1);
4196 } else if (root->ref_cows) {
4197 inode_sub_bytes(inode, item_end + 1 -
4198 found_key.offset);
4199 }
4200 }
4201 delete:
4202 if (del_item) {
4203 if (!pending_del_nr) {
4204 /* no pending yet, add ourselves */
4205 pending_del_slot = path->slots[0];
4206 pending_del_nr = 1;
4207 } else if (pending_del_nr &&
4208 path->slots[0] + 1 == pending_del_slot) {
4209 /* hop on the pending chunk */
4210 pending_del_nr++;
4211 pending_del_slot = path->slots[0];
4212 } else {
4213 BUG();
4214 }
4215 } else {
4216 break;
4217 }
4218 if (found_extent && (root->ref_cows ||
4219 root == root->fs_info->tree_root)) {
4220 btrfs_set_path_blocking(path);
4221 ret = btrfs_free_extent(trans, root, extent_start,
4222 extent_num_bytes, 0,
4223 btrfs_header_owner(leaf),
4224 ino, extent_offset, 0);
4225 BUG_ON(ret);
4226 }
4227
4228 if (found_type == BTRFS_INODE_ITEM_KEY)
4229 break;
4230
4231 if (path->slots[0] == 0 ||
4232 path->slots[0] != pending_del_slot) {
4233 if (pending_del_nr) {
4234 ret = btrfs_del_items(trans, root, path,
4235 pending_del_slot,
4236 pending_del_nr);
4237 if (ret) {
4238 btrfs_abort_transaction(trans,
4239 root, ret);
4240 goto error;
4241 }
4242 pending_del_nr = 0;
4243 }
4244 btrfs_release_path(path);
4245 goto search_again;
4246 } else {
4247 path->slots[0]--;
4248 }
4249 }
4250 out:
4251 if (pending_del_nr) {
4252 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4253 pending_del_nr);
4254 if (ret)
4255 btrfs_abort_transaction(trans, root, ret);
4256 }
4257 error:
4258 btrfs_free_path(path);
4259 return err;
4260 }
4261
4262 /*
4263 * btrfs_truncate_page - read, zero a chunk and write a page
4264 * @inode - inode that we're zeroing
4265 * @from - the offset to start zeroing
4266 * @len - the length to zero, 0 to zero the entire range respective to the
4267 * offset
4268 * @front - zero up to the offset instead of from the offset on
4269 *
4270 * This will find the page for the "from" offset and cow the page and zero the
4271 * part we want to zero. This is used with truncate and hole punching.
4272 */
4273 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
4274 int front)
4275 {
4276 struct address_space *mapping = inode->i_mapping;
4277 struct btrfs_root *root = BTRFS_I(inode)->root;
4278 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4279 struct btrfs_ordered_extent *ordered;
4280 struct extent_state *cached_state = NULL;
4281 char *kaddr;
4282 u32 blocksize = root->sectorsize;
4283 pgoff_t index = from >> PAGE_CACHE_SHIFT;
4284 unsigned offset = from & (PAGE_CACHE_SIZE-1);
4285 struct page *page;
4286 gfp_t mask = btrfs_alloc_write_mask(mapping);
4287 int ret = 0;
4288 u64 page_start;
4289 u64 page_end;
4290
4291 if ((offset & (blocksize - 1)) == 0 &&
4292 (!len || ((len & (blocksize - 1)) == 0)))
4293 goto out;
4294 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
4295 if (ret)
4296 goto out;
4297
4298 again:
4299 page = find_or_create_page(mapping, index, mask);
4300 if (!page) {
4301 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4302 ret = -ENOMEM;
4303 goto out;
4304 }
4305
4306 page_start = page_offset(page);
4307 page_end = page_start + PAGE_CACHE_SIZE - 1;
4308
4309 if (!PageUptodate(page)) {
4310 ret = btrfs_readpage(NULL, page);
4311 lock_page(page);
4312 if (page->mapping != mapping) {
4313 unlock_page(page);
4314 page_cache_release(page);
4315 goto again;
4316 }
4317 if (!PageUptodate(page)) {
4318 ret = -EIO;
4319 goto out_unlock;
4320 }
4321 }
4322 wait_on_page_writeback(page);
4323
4324 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
4325 set_page_extent_mapped(page);
4326
4327 ordered = btrfs_lookup_ordered_extent(inode, page_start);
4328 if (ordered) {
4329 unlock_extent_cached(io_tree, page_start, page_end,
4330 &cached_state, GFP_NOFS);
4331 unlock_page(page);
4332 page_cache_release(page);
4333 btrfs_start_ordered_extent(inode, ordered, 1);
4334 btrfs_put_ordered_extent(ordered);
4335 goto again;
4336 }
4337
4338 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
4339 EXTENT_DIRTY | EXTENT_DELALLOC |
4340 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4341 0, 0, &cached_state, GFP_NOFS);
4342
4343 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
4344 &cached_state);
4345 if (ret) {
4346 unlock_extent_cached(io_tree, page_start, page_end,
4347 &cached_state, GFP_NOFS);
4348 goto out_unlock;
4349 }
4350
4351 if (offset != PAGE_CACHE_SIZE) {
4352 if (!len)
4353 len = PAGE_CACHE_SIZE - offset;
4354 kaddr = kmap(page);
4355 if (front)
4356 memset(kaddr, 0, offset);
4357 else
4358 memset(kaddr + offset, 0, len);
4359 flush_dcache_page(page);
4360 kunmap(page);
4361 }
4362 ClearPageChecked(page);
4363 set_page_dirty(page);
4364 unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
4365 GFP_NOFS);
4366
4367 out_unlock:
4368 if (ret)
4369 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4370 unlock_page(page);
4371 page_cache_release(page);
4372 out:
4373 return ret;
4374 }
4375
4376 /*
4377 * This function puts in dummy file extents for the area we're creating a hole
4378 * for. So if we are truncating this file to a larger size we need to insert
4379 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4380 * the range between oldsize and size
4381 */
4382 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4383 {
4384 struct btrfs_trans_handle *trans;
4385 struct btrfs_root *root = BTRFS_I(inode)->root;
4386 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4387 struct extent_map *em = NULL;
4388 struct extent_state *cached_state = NULL;
4389 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4390 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4391 u64 block_end = ALIGN(size, root->sectorsize);
4392 u64 last_byte;
4393 u64 cur_offset;
4394 u64 hole_size;
4395 int err = 0;
4396
4397 if (size <= hole_start)
4398 return 0;
4399
4400 while (1) {
4401 struct btrfs_ordered_extent *ordered;
4402 btrfs_wait_ordered_range(inode, hole_start,
4403 block_end - hole_start);
4404 lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
4405 &cached_state);
4406 ordered = btrfs_lookup_ordered_extent(inode, hole_start);
4407 if (!ordered)
4408 break;
4409 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4410 &cached_state, GFP_NOFS);
4411 btrfs_put_ordered_extent(ordered);
4412 }
4413
4414 cur_offset = hole_start;
4415 while (1) {
4416 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4417 block_end - cur_offset, 0);
4418 if (IS_ERR(em)) {
4419 err = PTR_ERR(em);
4420 em = NULL;
4421 break;
4422 }
4423 last_byte = min(extent_map_end(em), block_end);
4424 last_byte = ALIGN(last_byte , root->sectorsize);
4425 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4426 struct extent_map *hole_em;
4427 hole_size = last_byte - cur_offset;
4428
4429 trans = btrfs_start_transaction(root, 3);
4430 if (IS_ERR(trans)) {
4431 err = PTR_ERR(trans);
4432 break;
4433 }
4434
4435 err = btrfs_drop_extents(trans, root, inode,
4436 cur_offset,
4437 cur_offset + hole_size, 1);
4438 if (err) {
4439 btrfs_abort_transaction(trans, root, err);
4440 btrfs_end_transaction(trans, root);
4441 break;
4442 }
4443
4444 err = btrfs_insert_file_extent(trans, root,
4445 btrfs_ino(inode), cur_offset, 0,
4446 0, hole_size, 0, hole_size,
4447 0, 0, 0);
4448 if (err) {
4449 btrfs_abort_transaction(trans, root, err);
4450 btrfs_end_transaction(trans, root);
4451 break;
4452 }
4453
4454 btrfs_drop_extent_cache(inode, cur_offset,
4455 cur_offset + hole_size - 1, 0);
4456 hole_em = alloc_extent_map();
4457 if (!hole_em) {
4458 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4459 &BTRFS_I(inode)->runtime_flags);
4460 goto next;
4461 }
4462 hole_em->start = cur_offset;
4463 hole_em->len = hole_size;
4464 hole_em->orig_start = cur_offset;
4465
4466 hole_em->block_start = EXTENT_MAP_HOLE;
4467 hole_em->block_len = 0;
4468 hole_em->orig_block_len = 0;
4469 hole_em->ram_bytes = hole_size;
4470 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4471 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4472 hole_em->generation = trans->transid;
4473
4474 while (1) {
4475 write_lock(&em_tree->lock);
4476 err = add_extent_mapping(em_tree, hole_em, 1);
4477 write_unlock(&em_tree->lock);
4478 if (err != -EEXIST)
4479 break;
4480 btrfs_drop_extent_cache(inode, cur_offset,
4481 cur_offset +
4482 hole_size - 1, 0);
4483 }
4484 free_extent_map(hole_em);
4485 next:
4486 btrfs_update_inode(trans, root, inode);
4487 btrfs_end_transaction(trans, root);
4488 }
4489 free_extent_map(em);
4490 em = NULL;
4491 cur_offset = last_byte;
4492 if (cur_offset >= block_end)
4493 break;
4494 }
4495
4496 free_extent_map(em);
4497 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4498 GFP_NOFS);
4499 return err;
4500 }
4501
4502 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4503 {
4504 struct btrfs_root *root = BTRFS_I(inode)->root;
4505 struct btrfs_trans_handle *trans;
4506 loff_t oldsize = i_size_read(inode);
4507 loff_t newsize = attr->ia_size;
4508 int mask = attr->ia_valid;
4509 int ret;
4510
4511 if (newsize == oldsize)
4512 return 0;
4513
4514 /*
4515 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4516 * special case where we need to update the times despite not having
4517 * these flags set. For all other operations the VFS set these flags
4518 * explicitly if it wants a timestamp update.
4519 */
4520 if (newsize != oldsize && (!(mask & (ATTR_CTIME | ATTR_MTIME))))
4521 inode->i_ctime = inode->i_mtime = current_fs_time(inode->i_sb);
4522
4523 if (newsize > oldsize) {
4524 truncate_pagecache(inode, oldsize, newsize);
4525 ret = btrfs_cont_expand(inode, oldsize, newsize);
4526 if (ret)
4527 return ret;
4528
4529 trans = btrfs_start_transaction(root, 1);
4530 if (IS_ERR(trans))
4531 return PTR_ERR(trans);
4532
4533 i_size_write(inode, newsize);
4534 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4535 ret = btrfs_update_inode(trans, root, inode);
4536 btrfs_end_transaction(trans, root);
4537 } else {
4538
4539 /*
4540 * We're truncating a file that used to have good data down to
4541 * zero. Make sure it gets into the ordered flush list so that
4542 * any new writes get down to disk quickly.
4543 */
4544 if (newsize == 0)
4545 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
4546 &BTRFS_I(inode)->runtime_flags);
4547
4548 /*
4549 * 1 for the orphan item we're going to add
4550 * 1 for the orphan item deletion.
4551 */
4552 trans = btrfs_start_transaction(root, 2);
4553 if (IS_ERR(trans))
4554 return PTR_ERR(trans);
4555
4556 /*
4557 * We need to do this in case we fail at _any_ point during the
4558 * actual truncate. Once we do the truncate_setsize we could
4559 * invalidate pages which forces any outstanding ordered io to
4560 * be instantly completed which will give us extents that need
4561 * to be truncated. If we fail to get an orphan inode down we
4562 * could have left over extents that were never meant to live,
4563 * so we need to garuntee from this point on that everything
4564 * will be consistent.
4565 */
4566 ret = btrfs_orphan_add(trans, inode);
4567 btrfs_end_transaction(trans, root);
4568 if (ret)
4569 return ret;
4570
4571 /* we don't support swapfiles, so vmtruncate shouldn't fail */
4572 truncate_setsize(inode, newsize);
4573
4574 /* Disable nonlocked read DIO to avoid the end less truncate */
4575 btrfs_inode_block_unlocked_dio(inode);
4576 inode_dio_wait(inode);
4577 btrfs_inode_resume_unlocked_dio(inode);
4578
4579 ret = btrfs_truncate(inode);
4580 if (ret && inode->i_nlink)
4581 btrfs_orphan_del(NULL, inode);
4582 }
4583
4584 return ret;
4585 }
4586
4587 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
4588 {
4589 struct inode *inode = dentry->d_inode;
4590 struct btrfs_root *root = BTRFS_I(inode)->root;
4591 int err;
4592
4593 if (btrfs_root_readonly(root))
4594 return -EROFS;
4595
4596 err = inode_change_ok(inode, attr);
4597 if (err)
4598 return err;
4599
4600 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
4601 err = btrfs_setsize(inode, attr);
4602 if (err)
4603 return err;
4604 }
4605
4606 if (attr->ia_valid) {
4607 setattr_copy(inode, attr);
4608 inode_inc_iversion(inode);
4609 err = btrfs_dirty_inode(inode);
4610
4611 if (!err && attr->ia_valid & ATTR_MODE)
4612 err = btrfs_acl_chmod(inode);
4613 }
4614
4615 return err;
4616 }
4617
4618 void btrfs_evict_inode(struct inode *inode)
4619 {
4620 struct btrfs_trans_handle *trans;
4621 struct btrfs_root *root = BTRFS_I(inode)->root;
4622 struct btrfs_block_rsv *rsv, *global_rsv;
4623 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
4624 int ret;
4625
4626 trace_btrfs_inode_evict(inode);
4627
4628 truncate_inode_pages(&inode->i_data, 0);
4629 if (inode->i_nlink && (btrfs_root_refs(&root->root_item) != 0 ||
4630 btrfs_is_free_space_inode(inode)))
4631 goto no_delete;
4632
4633 if (is_bad_inode(inode)) {
4634 btrfs_orphan_del(NULL, inode);
4635 goto no_delete;
4636 }
4637 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
4638 btrfs_wait_ordered_range(inode, 0, (u64)-1);
4639
4640 if (root->fs_info->log_root_recovering) {
4641 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
4642 &BTRFS_I(inode)->runtime_flags));
4643 goto no_delete;
4644 }
4645
4646 if (inode->i_nlink > 0) {
4647 BUG_ON(btrfs_root_refs(&root->root_item) != 0);
4648 goto no_delete;
4649 }
4650
4651 ret = btrfs_commit_inode_delayed_inode(inode);
4652 if (ret) {
4653 btrfs_orphan_del(NULL, inode);
4654 goto no_delete;
4655 }
4656
4657 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
4658 if (!rsv) {
4659 btrfs_orphan_del(NULL, inode);
4660 goto no_delete;
4661 }
4662 rsv->size = min_size;
4663 rsv->failfast = 1;
4664 global_rsv = &root->fs_info->global_block_rsv;
4665
4666 btrfs_i_size_write(inode, 0);
4667
4668 /*
4669 * This is a bit simpler than btrfs_truncate since we've already
4670 * reserved our space for our orphan item in the unlink, so we just
4671 * need to reserve some slack space in case we add bytes and update
4672 * inode item when doing the truncate.
4673 */
4674 while (1) {
4675 ret = btrfs_block_rsv_refill(root, rsv, min_size,
4676 BTRFS_RESERVE_FLUSH_LIMIT);
4677
4678 /*
4679 * Try and steal from the global reserve since we will
4680 * likely not use this space anyway, we want to try as
4681 * hard as possible to get this to work.
4682 */
4683 if (ret)
4684 ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size);
4685
4686 if (ret) {
4687 btrfs_warn(root->fs_info,
4688 "Could not get space for a delete, will truncate on mount %d",
4689 ret);
4690 btrfs_orphan_del(NULL, inode);
4691 btrfs_free_block_rsv(root, rsv);
4692 goto no_delete;
4693 }
4694
4695 trans = btrfs_join_transaction(root);
4696 if (IS_ERR(trans)) {
4697 btrfs_orphan_del(NULL, inode);
4698 btrfs_free_block_rsv(root, rsv);
4699 goto no_delete;
4700 }
4701
4702 trans->block_rsv = rsv;
4703
4704 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
4705 if (ret != -ENOSPC)
4706 break;
4707
4708 trans->block_rsv = &root->fs_info->trans_block_rsv;
4709 btrfs_end_transaction(trans, root);
4710 trans = NULL;
4711 btrfs_btree_balance_dirty(root);
4712 }
4713
4714 btrfs_free_block_rsv(root, rsv);
4715
4716 if (ret == 0) {
4717 trans->block_rsv = root->orphan_block_rsv;
4718 ret = btrfs_orphan_del(trans, inode);
4719 BUG_ON(ret);
4720 }
4721
4722 trans->block_rsv = &root->fs_info->trans_block_rsv;
4723 if (!(root == root->fs_info->tree_root ||
4724 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
4725 btrfs_return_ino(root, btrfs_ino(inode));
4726
4727 btrfs_end_transaction(trans, root);
4728 btrfs_btree_balance_dirty(root);
4729 no_delete:
4730 clear_inode(inode);
4731 return;
4732 }
4733
4734 /*
4735 * this returns the key found in the dir entry in the location pointer.
4736 * If no dir entries were found, location->objectid is 0.
4737 */
4738 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
4739 struct btrfs_key *location)
4740 {
4741 const char *name = dentry->d_name.name;
4742 int namelen = dentry->d_name.len;
4743 struct btrfs_dir_item *di;
4744 struct btrfs_path *path;
4745 struct btrfs_root *root = BTRFS_I(dir)->root;
4746 int ret = 0;
4747
4748 path = btrfs_alloc_path();
4749 if (!path)
4750 return -ENOMEM;
4751
4752 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
4753 namelen, 0);
4754 if (IS_ERR(di))
4755 ret = PTR_ERR(di);
4756
4757 if (IS_ERR_OR_NULL(di))
4758 goto out_err;
4759
4760 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
4761 out:
4762 btrfs_free_path(path);
4763 return ret;
4764 out_err:
4765 location->objectid = 0;
4766 goto out;
4767 }
4768
4769 /*
4770 * when we hit a tree root in a directory, the btrfs part of the inode
4771 * needs to be changed to reflect the root directory of the tree root. This
4772 * is kind of like crossing a mount point.
4773 */
4774 static int fixup_tree_root_location(struct btrfs_root *root,
4775 struct inode *dir,
4776 struct dentry *dentry,
4777 struct btrfs_key *location,
4778 struct btrfs_root **sub_root)
4779 {
4780 struct btrfs_path *path;
4781 struct btrfs_root *new_root;
4782 struct btrfs_root_ref *ref;
4783 struct extent_buffer *leaf;
4784 int ret;
4785 int err = 0;
4786
4787 path = btrfs_alloc_path();
4788 if (!path) {
4789 err = -ENOMEM;
4790 goto out;
4791 }
4792
4793 err = -ENOENT;
4794 ret = btrfs_find_root_ref(root->fs_info->tree_root, path,
4795 BTRFS_I(dir)->root->root_key.objectid,
4796 location->objectid);
4797 if (ret) {
4798 if (ret < 0)
4799 err = ret;
4800 goto out;
4801 }
4802
4803 leaf = path->nodes[0];
4804 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
4805 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
4806 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
4807 goto out;
4808
4809 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
4810 (unsigned long)(ref + 1),
4811 dentry->d_name.len);
4812 if (ret)
4813 goto out;
4814
4815 btrfs_release_path(path);
4816
4817 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
4818 if (IS_ERR(new_root)) {
4819 err = PTR_ERR(new_root);
4820 goto out;
4821 }
4822
4823 if (btrfs_root_refs(&new_root->root_item) == 0) {
4824 err = -ENOENT;
4825 goto out;
4826 }
4827
4828 *sub_root = new_root;
4829 location->objectid = btrfs_root_dirid(&new_root->root_item);
4830 location->type = BTRFS_INODE_ITEM_KEY;
4831 location->offset = 0;
4832 err = 0;
4833 out:
4834 btrfs_free_path(path);
4835 return err;
4836 }
4837
4838 static void inode_tree_add(struct inode *inode)
4839 {
4840 struct btrfs_root *root = BTRFS_I(inode)->root;
4841 struct btrfs_inode *entry;
4842 struct rb_node **p;
4843 struct rb_node *parent;
4844 u64 ino = btrfs_ino(inode);
4845 again:
4846 p = &root->inode_tree.rb_node;
4847 parent = NULL;
4848
4849 if (inode_unhashed(inode))
4850 return;
4851
4852 spin_lock(&root->inode_lock);
4853 while (*p) {
4854 parent = *p;
4855 entry = rb_entry(parent, struct btrfs_inode, rb_node);
4856
4857 if (ino < btrfs_ino(&entry->vfs_inode))
4858 p = &parent->rb_left;
4859 else if (ino > btrfs_ino(&entry->vfs_inode))
4860 p = &parent->rb_right;
4861 else {
4862 WARN_ON(!(entry->vfs_inode.i_state &
4863 (I_WILL_FREE | I_FREEING)));
4864 rb_erase(parent, &root->inode_tree);
4865 RB_CLEAR_NODE(parent);
4866 spin_unlock(&root->inode_lock);
4867 goto again;
4868 }
4869 }
4870 rb_link_node(&BTRFS_I(inode)->rb_node, parent, p);
4871 rb_insert_color(&BTRFS_I(inode)->rb_node, &root->inode_tree);
4872 spin_unlock(&root->inode_lock);
4873 }
4874
4875 static void inode_tree_del(struct inode *inode)
4876 {
4877 struct btrfs_root *root = BTRFS_I(inode)->root;
4878 int empty = 0;
4879
4880 spin_lock(&root->inode_lock);
4881 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
4882 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
4883 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
4884 empty = RB_EMPTY_ROOT(&root->inode_tree);
4885 }
4886 spin_unlock(&root->inode_lock);
4887
4888 /*
4889 * Free space cache has inodes in the tree root, but the tree root has a
4890 * root_refs of 0, so this could end up dropping the tree root as a
4891 * snapshot, so we need the extra !root->fs_info->tree_root check to
4892 * make sure we don't drop it.
4893 */
4894 if (empty && btrfs_root_refs(&root->root_item) == 0 &&
4895 root != root->fs_info->tree_root) {
4896 synchronize_srcu(&root->fs_info->subvol_srcu);
4897 spin_lock(&root->inode_lock);
4898 empty = RB_EMPTY_ROOT(&root->inode_tree);
4899 spin_unlock(&root->inode_lock);
4900 if (empty)
4901 btrfs_add_dead_root(root);
4902 }
4903 }
4904
4905 void btrfs_invalidate_inodes(struct btrfs_root *root)
4906 {
4907 struct rb_node *node;
4908 struct rb_node *prev;
4909 struct btrfs_inode *entry;
4910 struct inode *inode;
4911 u64 objectid = 0;
4912
4913 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
4914
4915 spin_lock(&root->inode_lock);
4916 again:
4917 node = root->inode_tree.rb_node;
4918 prev = NULL;
4919 while (node) {
4920 prev = node;
4921 entry = rb_entry(node, struct btrfs_inode, rb_node);
4922
4923 if (objectid < btrfs_ino(&entry->vfs_inode))
4924 node = node->rb_left;
4925 else if (objectid > btrfs_ino(&entry->vfs_inode))
4926 node = node->rb_right;
4927 else
4928 break;
4929 }
4930 if (!node) {
4931 while (prev) {
4932 entry = rb_entry(prev, struct btrfs_inode, rb_node);
4933 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
4934 node = prev;
4935 break;
4936 }
4937 prev = rb_next(prev);
4938 }
4939 }
4940 while (node) {
4941 entry = rb_entry(node, struct btrfs_inode, rb_node);
4942 objectid = btrfs_ino(&entry->vfs_inode) + 1;
4943 inode = igrab(&entry->vfs_inode);
4944 if (inode) {
4945 spin_unlock(&root->inode_lock);
4946 if (atomic_read(&inode->i_count) > 1)
4947 d_prune_aliases(inode);
4948 /*
4949 * btrfs_drop_inode will have it removed from
4950 * the inode cache when its usage count
4951 * hits zero.
4952 */
4953 iput(inode);
4954 cond_resched();
4955 spin_lock(&root->inode_lock);
4956 goto again;
4957 }
4958
4959 if (cond_resched_lock(&root->inode_lock))
4960 goto again;
4961
4962 node = rb_next(node);
4963 }
4964 spin_unlock(&root->inode_lock);
4965 }
4966
4967 static int btrfs_init_locked_inode(struct inode *inode, void *p)
4968 {
4969 struct btrfs_iget_args *args = p;
4970 inode->i_ino = args->ino;
4971 BTRFS_I(inode)->root = args->root;
4972 return 0;
4973 }
4974
4975 static int btrfs_find_actor(struct inode *inode, void *opaque)
4976 {
4977 struct btrfs_iget_args *args = opaque;
4978 return args->ino == btrfs_ino(inode) &&
4979 args->root == BTRFS_I(inode)->root;
4980 }
4981
4982 static struct inode *btrfs_iget_locked(struct super_block *s,
4983 u64 objectid,
4984 struct btrfs_root *root)
4985 {
4986 struct inode *inode;
4987 struct btrfs_iget_args args;
4988 args.ino = objectid;
4989 args.root = root;
4990
4991 inode = iget5_locked(s, objectid, btrfs_find_actor,
4992 btrfs_init_locked_inode,
4993 (void *)&args);
4994 return inode;
4995 }
4996
4997 /* Get an inode object given its location and corresponding root.
4998 * Returns in *is_new if the inode was read from disk
4999 */
5000 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5001 struct btrfs_root *root, int *new)
5002 {
5003 struct inode *inode;
5004
5005 inode = btrfs_iget_locked(s, location->objectid, root);
5006 if (!inode)
5007 return ERR_PTR(-ENOMEM);
5008
5009 if (inode->i_state & I_NEW) {
5010 BTRFS_I(inode)->root = root;
5011 memcpy(&BTRFS_I(inode)->location, location, sizeof(*location));
5012 btrfs_read_locked_inode(inode);
5013 if (!is_bad_inode(inode)) {
5014 inode_tree_add(inode);
5015 unlock_new_inode(inode);
5016 if (new)
5017 *new = 1;
5018 } else {
5019 unlock_new_inode(inode);
5020 iput(inode);
5021 inode = ERR_PTR(-ESTALE);
5022 }
5023 }
5024
5025 return inode;
5026 }
5027
5028 static struct inode *new_simple_dir(struct super_block *s,
5029 struct btrfs_key *key,
5030 struct btrfs_root *root)
5031 {
5032 struct inode *inode = new_inode(s);
5033
5034 if (!inode)
5035 return ERR_PTR(-ENOMEM);
5036
5037 BTRFS_I(inode)->root = root;
5038 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5039 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5040
5041 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5042 inode->i_op = &btrfs_dir_ro_inode_operations;
5043 inode->i_fop = &simple_dir_operations;
5044 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5045 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
5046
5047 return inode;
5048 }
5049
5050 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5051 {
5052 struct inode *inode;
5053 struct btrfs_root *root = BTRFS_I(dir)->root;
5054 struct btrfs_root *sub_root = root;
5055 struct btrfs_key location;
5056 int index;
5057 int ret = 0;
5058
5059 if (dentry->d_name.len > BTRFS_NAME_LEN)
5060 return ERR_PTR(-ENAMETOOLONG);
5061
5062 ret = btrfs_inode_by_name(dir, dentry, &location);
5063 if (ret < 0)
5064 return ERR_PTR(ret);
5065
5066 if (location.objectid == 0)
5067 return NULL;
5068
5069 if (location.type == BTRFS_INODE_ITEM_KEY) {
5070 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5071 return inode;
5072 }
5073
5074 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5075
5076 index = srcu_read_lock(&root->fs_info->subvol_srcu);
5077 ret = fixup_tree_root_location(root, dir, dentry,
5078 &location, &sub_root);
5079 if (ret < 0) {
5080 if (ret != -ENOENT)
5081 inode = ERR_PTR(ret);
5082 else
5083 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5084 } else {
5085 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5086 }
5087 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
5088
5089 if (!IS_ERR(inode) && root != sub_root) {
5090 down_read(&root->fs_info->cleanup_work_sem);
5091 if (!(inode->i_sb->s_flags & MS_RDONLY))
5092 ret = btrfs_orphan_cleanup(sub_root);
5093 up_read(&root->fs_info->cleanup_work_sem);
5094 if (ret)
5095 inode = ERR_PTR(ret);
5096 }
5097
5098 return inode;
5099 }
5100
5101 static int btrfs_dentry_delete(const struct dentry *dentry)
5102 {
5103 struct btrfs_root *root;
5104 struct inode *inode = dentry->d_inode;
5105
5106 if (!inode && !IS_ROOT(dentry))
5107 inode = dentry->d_parent->d_inode;
5108
5109 if (inode) {
5110 root = BTRFS_I(inode)->root;
5111 if (btrfs_root_refs(&root->root_item) == 0)
5112 return 1;
5113
5114 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5115 return 1;
5116 }
5117 return 0;
5118 }
5119
5120 static void btrfs_dentry_release(struct dentry *dentry)
5121 {
5122 if (dentry->d_fsdata)
5123 kfree(dentry->d_fsdata);
5124 }
5125
5126 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5127 unsigned int flags)
5128 {
5129 struct dentry *ret;
5130
5131 ret = d_splice_alias(btrfs_lookup_dentry(dir, dentry), dentry);
5132 return ret;
5133 }
5134
5135 unsigned char btrfs_filetype_table[] = {
5136 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5137 };
5138
5139 static int btrfs_real_readdir(struct file *filp, void *dirent,
5140 filldir_t filldir)
5141 {
5142 struct inode *inode = file_inode(filp);
5143 struct btrfs_root *root = BTRFS_I(inode)->root;
5144 struct btrfs_item *item;
5145 struct btrfs_dir_item *di;
5146 struct btrfs_key key;
5147 struct btrfs_key found_key;
5148 struct btrfs_path *path;
5149 struct list_head ins_list;
5150 struct list_head del_list;
5151 int ret;
5152 struct extent_buffer *leaf;
5153 int slot;
5154 unsigned char d_type;
5155 int over = 0;
5156 u32 di_cur;
5157 u32 di_total;
5158 u32 di_len;
5159 int key_type = BTRFS_DIR_INDEX_KEY;
5160 char tmp_name[32];
5161 char *name_ptr;
5162 int name_len;
5163 int is_curr = 0; /* filp->f_pos points to the current index? */
5164
5165 /* FIXME, use a real flag for deciding about the key type */
5166 if (root->fs_info->tree_root == root)
5167 key_type = BTRFS_DIR_ITEM_KEY;
5168
5169 /* special case for "." */
5170 if (filp->f_pos == 0) {
5171 over = filldir(dirent, ".", 1,
5172 filp->f_pos, btrfs_ino(inode), DT_DIR);
5173 if (over)
5174 return 0;
5175 filp->f_pos = 1;
5176 }
5177 /* special case for .., just use the back ref */
5178 if (filp->f_pos == 1) {
5179 u64 pino = parent_ino(filp->f_path.dentry);
5180 over = filldir(dirent, "..", 2,
5181 filp->f_pos, pino, DT_DIR);
5182 if (over)
5183 return 0;
5184 filp->f_pos = 2;
5185 }
5186 path = btrfs_alloc_path();
5187 if (!path)
5188 return -ENOMEM;
5189
5190 path->reada = 1;
5191
5192 if (key_type == BTRFS_DIR_INDEX_KEY) {
5193 INIT_LIST_HEAD(&ins_list);
5194 INIT_LIST_HEAD(&del_list);
5195 btrfs_get_delayed_items(inode, &ins_list, &del_list);
5196 }
5197
5198 btrfs_set_key_type(&key, key_type);
5199 key.offset = filp->f_pos;
5200 key.objectid = btrfs_ino(inode);
5201
5202 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5203 if (ret < 0)
5204 goto err;
5205
5206 while (1) {
5207 leaf = path->nodes[0];
5208 slot = path->slots[0];
5209 if (slot >= btrfs_header_nritems(leaf)) {
5210 ret = btrfs_next_leaf(root, path);
5211 if (ret < 0)
5212 goto err;
5213 else if (ret > 0)
5214 break;
5215 continue;
5216 }
5217
5218 item = btrfs_item_nr(leaf, slot);
5219 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5220
5221 if (found_key.objectid != key.objectid)
5222 break;
5223 if (btrfs_key_type(&found_key) != key_type)
5224 break;
5225 if (found_key.offset < filp->f_pos)
5226 goto next;
5227 if (key_type == BTRFS_DIR_INDEX_KEY &&
5228 btrfs_should_delete_dir_index(&del_list,
5229 found_key.offset))
5230 goto next;
5231
5232 filp->f_pos = found_key.offset;
5233 is_curr = 1;
5234
5235 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5236 di_cur = 0;
5237 di_total = btrfs_item_size(leaf, item);
5238
5239 while (di_cur < di_total) {
5240 struct btrfs_key location;
5241
5242 if (verify_dir_item(root, leaf, di))
5243 break;
5244
5245 name_len = btrfs_dir_name_len(leaf, di);
5246 if (name_len <= sizeof(tmp_name)) {
5247 name_ptr = tmp_name;
5248 } else {
5249 name_ptr = kmalloc(name_len, GFP_NOFS);
5250 if (!name_ptr) {
5251 ret = -ENOMEM;
5252 goto err;
5253 }
5254 }
5255 read_extent_buffer(leaf, name_ptr,
5256 (unsigned long)(di + 1), name_len);
5257
5258 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5259 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5260
5261
5262 /* is this a reference to our own snapshot? If so
5263 * skip it.
5264 *
5265 * In contrast to old kernels, we insert the snapshot's
5266 * dir item and dir index after it has been created, so
5267 * we won't find a reference to our own snapshot. We
5268 * still keep the following code for backward
5269 * compatibility.
5270 */
5271 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5272 location.objectid == root->root_key.objectid) {
5273 over = 0;
5274 goto skip;
5275 }
5276 over = filldir(dirent, name_ptr, name_len,
5277 found_key.offset, location.objectid,
5278 d_type);
5279
5280 skip:
5281 if (name_ptr != tmp_name)
5282 kfree(name_ptr);
5283
5284 if (over)
5285 goto nopos;
5286 di_len = btrfs_dir_name_len(leaf, di) +
5287 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5288 di_cur += di_len;
5289 di = (struct btrfs_dir_item *)((char *)di + di_len);
5290 }
5291 next:
5292 path->slots[0]++;
5293 }
5294
5295 if (key_type == BTRFS_DIR_INDEX_KEY) {
5296 if (is_curr)
5297 filp->f_pos++;
5298 ret = btrfs_readdir_delayed_dir_index(filp, dirent, filldir,
5299 &ins_list);
5300 if (ret)
5301 goto nopos;
5302 }
5303
5304 /* Reached end of directory/root. Bump pos past the last item. */
5305 if (key_type == BTRFS_DIR_INDEX_KEY)
5306 /*
5307 * 32-bit glibc will use getdents64, but then strtol -
5308 * so the last number we can serve is this.
5309 */
5310 filp->f_pos = 0x7fffffff;
5311 else
5312 filp->f_pos++;
5313 nopos:
5314 ret = 0;
5315 err:
5316 if (key_type == BTRFS_DIR_INDEX_KEY)
5317 btrfs_put_delayed_items(&ins_list, &del_list);
5318 btrfs_free_path(path);
5319 return ret;
5320 }
5321
5322 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5323 {
5324 struct btrfs_root *root = BTRFS_I(inode)->root;
5325 struct btrfs_trans_handle *trans;
5326 int ret = 0;
5327 bool nolock = false;
5328
5329 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5330 return 0;
5331
5332 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5333 nolock = true;
5334
5335 if (wbc->sync_mode == WB_SYNC_ALL) {
5336 if (nolock)
5337 trans = btrfs_join_transaction_nolock(root);
5338 else
5339 trans = btrfs_join_transaction(root);
5340 if (IS_ERR(trans))
5341 return PTR_ERR(trans);
5342 ret = btrfs_commit_transaction(trans, root);
5343 }
5344 return ret;
5345 }
5346
5347 /*
5348 * This is somewhat expensive, updating the tree every time the
5349 * inode changes. But, it is most likely to find the inode in cache.
5350 * FIXME, needs more benchmarking...there are no reasons other than performance
5351 * to keep or drop this code.
5352 */
5353 static int btrfs_dirty_inode(struct inode *inode)
5354 {
5355 struct btrfs_root *root = BTRFS_I(inode)->root;
5356 struct btrfs_trans_handle *trans;
5357 int ret;
5358
5359 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5360 return 0;
5361
5362 trans = btrfs_join_transaction(root);
5363 if (IS_ERR(trans))
5364 return PTR_ERR(trans);
5365
5366 ret = btrfs_update_inode(trans, root, inode);
5367 if (ret && ret == -ENOSPC) {
5368 /* whoops, lets try again with the full transaction */
5369 btrfs_end_transaction(trans, root);
5370 trans = btrfs_start_transaction(root, 1);
5371 if (IS_ERR(trans))
5372 return PTR_ERR(trans);
5373
5374 ret = btrfs_update_inode(trans, root, inode);
5375 }
5376 btrfs_end_transaction(trans, root);
5377 if (BTRFS_I(inode)->delayed_node)
5378 btrfs_balance_delayed_items(root);
5379
5380 return ret;
5381 }
5382
5383 /*
5384 * This is a copy of file_update_time. We need this so we can return error on
5385 * ENOSPC for updating the inode in the case of file write and mmap writes.
5386 */
5387 static int btrfs_update_time(struct inode *inode, struct timespec *now,
5388 int flags)
5389 {
5390 struct btrfs_root *root = BTRFS_I(inode)->root;
5391
5392 if (btrfs_root_readonly(root))
5393 return -EROFS;
5394
5395 if (flags & S_VERSION)
5396 inode_inc_iversion(inode);
5397 if (flags & S_CTIME)
5398 inode->i_ctime = *now;
5399 if (flags & S_MTIME)
5400 inode->i_mtime = *now;
5401 if (flags & S_ATIME)
5402 inode->i_atime = *now;
5403 return btrfs_dirty_inode(inode);
5404 }
5405
5406 /*
5407 * find the highest existing sequence number in a directory
5408 * and then set the in-memory index_cnt variable to reflect
5409 * free sequence numbers
5410 */
5411 static int btrfs_set_inode_index_count(struct inode *inode)
5412 {
5413 struct btrfs_root *root = BTRFS_I(inode)->root;
5414 struct btrfs_key key, found_key;
5415 struct btrfs_path *path;
5416 struct extent_buffer *leaf;
5417 int ret;
5418
5419 key.objectid = btrfs_ino(inode);
5420 btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
5421 key.offset = (u64)-1;
5422
5423 path = btrfs_alloc_path();
5424 if (!path)
5425 return -ENOMEM;
5426
5427 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5428 if (ret < 0)
5429 goto out;
5430 /* FIXME: we should be able to handle this */
5431 if (ret == 0)
5432 goto out;
5433 ret = 0;
5434
5435 /*
5436 * MAGIC NUMBER EXPLANATION:
5437 * since we search a directory based on f_pos we have to start at 2
5438 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
5439 * else has to start at 2
5440 */
5441 if (path->slots[0] == 0) {
5442 BTRFS_I(inode)->index_cnt = 2;
5443 goto out;
5444 }
5445
5446 path->slots[0]--;
5447
5448 leaf = path->nodes[0];
5449 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5450
5451 if (found_key.objectid != btrfs_ino(inode) ||
5452 btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) {
5453 BTRFS_I(inode)->index_cnt = 2;
5454 goto out;
5455 }
5456
5457 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
5458 out:
5459 btrfs_free_path(path);
5460 return ret;
5461 }
5462
5463 /*
5464 * helper to find a free sequence number in a given directory. This current
5465 * code is very simple, later versions will do smarter things in the btree
5466 */
5467 int btrfs_set_inode_index(struct inode *dir, u64 *index)
5468 {
5469 int ret = 0;
5470
5471 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
5472 ret = btrfs_inode_delayed_dir_index_count(dir);
5473 if (ret) {
5474 ret = btrfs_set_inode_index_count(dir);
5475 if (ret)
5476 return ret;
5477 }
5478 }
5479
5480 *index = BTRFS_I(dir)->index_cnt;
5481 BTRFS_I(dir)->index_cnt++;
5482
5483 return ret;
5484 }
5485
5486 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
5487 struct btrfs_root *root,
5488 struct inode *dir,
5489 const char *name, int name_len,
5490 u64 ref_objectid, u64 objectid,
5491 umode_t mode, u64 *index)
5492 {
5493 struct inode *inode;
5494 struct btrfs_inode_item *inode_item;
5495 struct btrfs_key *location;
5496 struct btrfs_path *path;
5497 struct btrfs_inode_ref *ref;
5498 struct btrfs_key key[2];
5499 u32 sizes[2];
5500 unsigned long ptr;
5501 int ret;
5502 int owner;
5503
5504 path = btrfs_alloc_path();
5505 if (!path)
5506 return ERR_PTR(-ENOMEM);
5507
5508 inode = new_inode(root->fs_info->sb);
5509 if (!inode) {
5510 btrfs_free_path(path);
5511 return ERR_PTR(-ENOMEM);
5512 }
5513
5514 /*
5515 * we have to initialize this early, so we can reclaim the inode
5516 * number if we fail afterwards in this function.
5517 */
5518 inode->i_ino = objectid;
5519
5520 if (dir) {
5521 trace_btrfs_inode_request(dir);
5522
5523 ret = btrfs_set_inode_index(dir, index);
5524 if (ret) {
5525 btrfs_free_path(path);
5526 iput(inode);
5527 return ERR_PTR(ret);
5528 }
5529 }
5530 /*
5531 * index_cnt is ignored for everything but a dir,
5532 * btrfs_get_inode_index_count has an explanation for the magic
5533 * number
5534 */
5535 BTRFS_I(inode)->index_cnt = 2;
5536 BTRFS_I(inode)->root = root;
5537 BTRFS_I(inode)->generation = trans->transid;
5538 inode->i_generation = BTRFS_I(inode)->generation;
5539
5540 /*
5541 * We could have gotten an inode number from somebody who was fsynced
5542 * and then removed in this same transaction, so let's just set full
5543 * sync since it will be a full sync anyway and this will blow away the
5544 * old info in the log.
5545 */
5546 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
5547
5548 if (S_ISDIR(mode))
5549 owner = 0;
5550 else
5551 owner = 1;
5552
5553 key[0].objectid = objectid;
5554 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
5555 key[0].offset = 0;
5556
5557 /*
5558 * Start new inodes with an inode_ref. This is slightly more
5559 * efficient for small numbers of hard links since they will
5560 * be packed into one item. Extended refs will kick in if we
5561 * add more hard links than can fit in the ref item.
5562 */
5563 key[1].objectid = objectid;
5564 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
5565 key[1].offset = ref_objectid;
5566
5567 sizes[0] = sizeof(struct btrfs_inode_item);
5568 sizes[1] = name_len + sizeof(*ref);
5569
5570 path->leave_spinning = 1;
5571 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
5572 if (ret != 0)
5573 goto fail;
5574
5575 inode_init_owner(inode, dir, mode);
5576 inode_set_bytes(inode, 0);
5577 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
5578 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
5579 struct btrfs_inode_item);
5580 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
5581 sizeof(*inode_item));
5582 fill_inode_item(trans, path->nodes[0], inode_item, inode);
5583
5584 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
5585 struct btrfs_inode_ref);
5586 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
5587 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
5588 ptr = (unsigned long)(ref + 1);
5589 write_extent_buffer(path->nodes[0], name, ptr, name_len);
5590
5591 btrfs_mark_buffer_dirty(path->nodes[0]);
5592 btrfs_free_path(path);
5593
5594 location = &BTRFS_I(inode)->location;
5595 location->objectid = objectid;
5596 location->offset = 0;
5597 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
5598
5599 btrfs_inherit_iflags(inode, dir);
5600
5601 if (S_ISREG(mode)) {
5602 if (btrfs_test_opt(root, NODATASUM))
5603 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
5604 if (btrfs_test_opt(root, NODATACOW))
5605 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
5606 BTRFS_INODE_NODATASUM;
5607 }
5608
5609 insert_inode_hash(inode);
5610 inode_tree_add(inode);
5611
5612 trace_btrfs_inode_new(inode);
5613 btrfs_set_inode_last_trans(trans, inode);
5614
5615 btrfs_update_root_times(trans, root);
5616
5617 return inode;
5618 fail:
5619 if (dir)
5620 BTRFS_I(dir)->index_cnt--;
5621 btrfs_free_path(path);
5622 iput(inode);
5623 return ERR_PTR(ret);
5624 }
5625
5626 static inline u8 btrfs_inode_type(struct inode *inode)
5627 {
5628 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
5629 }
5630
5631 /*
5632 * utility function to add 'inode' into 'parent_inode' with
5633 * a give name and a given sequence number.
5634 * if 'add_backref' is true, also insert a backref from the
5635 * inode to the parent directory.
5636 */
5637 int btrfs_add_link(struct btrfs_trans_handle *trans,
5638 struct inode *parent_inode, struct inode *inode,
5639 const char *name, int name_len, int add_backref, u64 index)
5640 {
5641 int ret = 0;
5642 struct btrfs_key key;
5643 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
5644 u64 ino = btrfs_ino(inode);
5645 u64 parent_ino = btrfs_ino(parent_inode);
5646
5647 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5648 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
5649 } else {
5650 key.objectid = ino;
5651 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
5652 key.offset = 0;
5653 }
5654
5655 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5656 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
5657 key.objectid, root->root_key.objectid,
5658 parent_ino, index, name, name_len);
5659 } else if (add_backref) {
5660 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
5661 parent_ino, index);
5662 }
5663
5664 /* Nothing to clean up yet */
5665 if (ret)
5666 return ret;
5667
5668 ret = btrfs_insert_dir_item(trans, root, name, name_len,
5669 parent_inode, &key,
5670 btrfs_inode_type(inode), index);
5671 if (ret == -EEXIST || ret == -EOVERFLOW)
5672 goto fail_dir_item;
5673 else if (ret) {
5674 btrfs_abort_transaction(trans, root, ret);
5675 return ret;
5676 }
5677
5678 btrfs_i_size_write(parent_inode, parent_inode->i_size +
5679 name_len * 2);
5680 inode_inc_iversion(parent_inode);
5681 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
5682 ret = btrfs_update_inode(trans, root, parent_inode);
5683 if (ret)
5684 btrfs_abort_transaction(trans, root, ret);
5685 return ret;
5686
5687 fail_dir_item:
5688 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5689 u64 local_index;
5690 int err;
5691 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
5692 key.objectid, root->root_key.objectid,
5693 parent_ino, &local_index, name, name_len);
5694
5695 } else if (add_backref) {
5696 u64 local_index;
5697 int err;
5698
5699 err = btrfs_del_inode_ref(trans, root, name, name_len,
5700 ino, parent_ino, &local_index);
5701 }
5702 return ret;
5703 }
5704
5705 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
5706 struct inode *dir, struct dentry *dentry,
5707 struct inode *inode, int backref, u64 index)
5708 {
5709 int err = btrfs_add_link(trans, dir, inode,
5710 dentry->d_name.name, dentry->d_name.len,
5711 backref, index);
5712 if (err > 0)
5713 err = -EEXIST;
5714 return err;
5715 }
5716
5717 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
5718 umode_t mode, dev_t rdev)
5719 {
5720 struct btrfs_trans_handle *trans;
5721 struct btrfs_root *root = BTRFS_I(dir)->root;
5722 struct inode *inode = NULL;
5723 int err;
5724 int drop_inode = 0;
5725 u64 objectid;
5726 u64 index = 0;
5727
5728 if (!new_valid_dev(rdev))
5729 return -EINVAL;
5730
5731 /*
5732 * 2 for inode item and ref
5733 * 2 for dir items
5734 * 1 for xattr if selinux is on
5735 */
5736 trans = btrfs_start_transaction(root, 5);
5737 if (IS_ERR(trans))
5738 return PTR_ERR(trans);
5739
5740 err = btrfs_find_free_ino(root, &objectid);
5741 if (err)
5742 goto out_unlock;
5743
5744 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5745 dentry->d_name.len, btrfs_ino(dir), objectid,
5746 mode, &index);
5747 if (IS_ERR(inode)) {
5748 err = PTR_ERR(inode);
5749 goto out_unlock;
5750 }
5751
5752 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5753 if (err) {
5754 drop_inode = 1;
5755 goto out_unlock;
5756 }
5757
5758 /*
5759 * If the active LSM wants to access the inode during
5760 * d_instantiate it needs these. Smack checks to see
5761 * if the filesystem supports xattrs by looking at the
5762 * ops vector.
5763 */
5764
5765 inode->i_op = &btrfs_special_inode_operations;
5766 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5767 if (err)
5768 drop_inode = 1;
5769 else {
5770 init_special_inode(inode, inode->i_mode, rdev);
5771 btrfs_update_inode(trans, root, inode);
5772 d_instantiate(dentry, inode);
5773 }
5774 out_unlock:
5775 btrfs_end_transaction(trans, root);
5776 btrfs_btree_balance_dirty(root);
5777 if (drop_inode) {
5778 inode_dec_link_count(inode);
5779 iput(inode);
5780 }
5781 return err;
5782 }
5783
5784 static int btrfs_create(struct inode *dir, struct dentry *dentry,
5785 umode_t mode, bool excl)
5786 {
5787 struct btrfs_trans_handle *trans;
5788 struct btrfs_root *root = BTRFS_I(dir)->root;
5789 struct inode *inode = NULL;
5790 int drop_inode_on_err = 0;
5791 int err;
5792 u64 objectid;
5793 u64 index = 0;
5794
5795 /*
5796 * 2 for inode item and ref
5797 * 2 for dir items
5798 * 1 for xattr if selinux is on
5799 */
5800 trans = btrfs_start_transaction(root, 5);
5801 if (IS_ERR(trans))
5802 return PTR_ERR(trans);
5803
5804 err = btrfs_find_free_ino(root, &objectid);
5805 if (err)
5806 goto out_unlock;
5807
5808 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5809 dentry->d_name.len, btrfs_ino(dir), objectid,
5810 mode, &index);
5811 if (IS_ERR(inode)) {
5812 err = PTR_ERR(inode);
5813 goto out_unlock;
5814 }
5815 drop_inode_on_err = 1;
5816
5817 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5818 if (err)
5819 goto out_unlock;
5820
5821 err = btrfs_update_inode(trans, root, inode);
5822 if (err)
5823 goto out_unlock;
5824
5825 /*
5826 * If the active LSM wants to access the inode during
5827 * d_instantiate it needs these. Smack checks to see
5828 * if the filesystem supports xattrs by looking at the
5829 * ops vector.
5830 */
5831 inode->i_fop = &btrfs_file_operations;
5832 inode->i_op = &btrfs_file_inode_operations;
5833
5834 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5835 if (err)
5836 goto out_unlock;
5837
5838 inode->i_mapping->a_ops = &btrfs_aops;
5839 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
5840 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
5841 d_instantiate(dentry, inode);
5842
5843 out_unlock:
5844 btrfs_end_transaction(trans, root);
5845 if (err && drop_inode_on_err) {
5846 inode_dec_link_count(inode);
5847 iput(inode);
5848 }
5849 btrfs_btree_balance_dirty(root);
5850 return err;
5851 }
5852
5853 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
5854 struct dentry *dentry)
5855 {
5856 struct btrfs_trans_handle *trans;
5857 struct btrfs_root *root = BTRFS_I(dir)->root;
5858 struct inode *inode = old_dentry->d_inode;
5859 u64 index;
5860 int err;
5861 int drop_inode = 0;
5862
5863 /* do not allow sys_link's with other subvols of the same device */
5864 if (root->objectid != BTRFS_I(inode)->root->objectid)
5865 return -EXDEV;
5866
5867 if (inode->i_nlink >= BTRFS_LINK_MAX)
5868 return -EMLINK;
5869
5870 err = btrfs_set_inode_index(dir, &index);
5871 if (err)
5872 goto fail;
5873
5874 /*
5875 * 2 items for inode and inode ref
5876 * 2 items for dir items
5877 * 1 item for parent inode
5878 */
5879 trans = btrfs_start_transaction(root, 5);
5880 if (IS_ERR(trans)) {
5881 err = PTR_ERR(trans);
5882 goto fail;
5883 }
5884
5885 btrfs_inc_nlink(inode);
5886 inode_inc_iversion(inode);
5887 inode->i_ctime = CURRENT_TIME;
5888 ihold(inode);
5889 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
5890
5891 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
5892
5893 if (err) {
5894 drop_inode = 1;
5895 } else {
5896 struct dentry *parent = dentry->d_parent;
5897 err = btrfs_update_inode(trans, root, inode);
5898 if (err)
5899 goto fail;
5900 d_instantiate(dentry, inode);
5901 btrfs_log_new_name(trans, inode, NULL, parent);
5902 }
5903
5904 btrfs_end_transaction(trans, root);
5905 fail:
5906 if (drop_inode) {
5907 inode_dec_link_count(inode);
5908 iput(inode);
5909 }
5910 btrfs_btree_balance_dirty(root);
5911 return err;
5912 }
5913
5914 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
5915 {
5916 struct inode *inode = NULL;
5917 struct btrfs_trans_handle *trans;
5918 struct btrfs_root *root = BTRFS_I(dir)->root;
5919 int err = 0;
5920 int drop_on_err = 0;
5921 u64 objectid = 0;
5922 u64 index = 0;
5923
5924 /*
5925 * 2 items for inode and ref
5926 * 2 items for dir items
5927 * 1 for xattr if selinux is on
5928 */
5929 trans = btrfs_start_transaction(root, 5);
5930 if (IS_ERR(trans))
5931 return PTR_ERR(trans);
5932
5933 err = btrfs_find_free_ino(root, &objectid);
5934 if (err)
5935 goto out_fail;
5936
5937 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5938 dentry->d_name.len, btrfs_ino(dir), objectid,
5939 S_IFDIR | mode, &index);
5940 if (IS_ERR(inode)) {
5941 err = PTR_ERR(inode);
5942 goto out_fail;
5943 }
5944
5945 drop_on_err = 1;
5946
5947 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5948 if (err)
5949 goto out_fail;
5950
5951 inode->i_op = &btrfs_dir_inode_operations;
5952 inode->i_fop = &btrfs_dir_file_operations;
5953
5954 btrfs_i_size_write(inode, 0);
5955 err = btrfs_update_inode(trans, root, inode);
5956 if (err)
5957 goto out_fail;
5958
5959 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
5960 dentry->d_name.len, 0, index);
5961 if (err)
5962 goto out_fail;
5963
5964 d_instantiate(dentry, inode);
5965 drop_on_err = 0;
5966
5967 out_fail:
5968 btrfs_end_transaction(trans, root);
5969 if (drop_on_err)
5970 iput(inode);
5971 btrfs_btree_balance_dirty(root);
5972 return err;
5973 }
5974
5975 /* helper for btfs_get_extent. Given an existing extent in the tree,
5976 * and an extent that you want to insert, deal with overlap and insert
5977 * the new extent into the tree.
5978 */
5979 static int merge_extent_mapping(struct extent_map_tree *em_tree,
5980 struct extent_map *existing,
5981 struct extent_map *em,
5982 u64 map_start, u64 map_len)
5983 {
5984 u64 start_diff;
5985
5986 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
5987 start_diff = map_start - em->start;
5988 em->start = map_start;
5989 em->len = map_len;
5990 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
5991 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
5992 em->block_start += start_diff;
5993 em->block_len -= start_diff;
5994 }
5995 return add_extent_mapping(em_tree, em, 0);
5996 }
5997
5998 static noinline int uncompress_inline(struct btrfs_path *path,
5999 struct inode *inode, struct page *page,
6000 size_t pg_offset, u64 extent_offset,
6001 struct btrfs_file_extent_item *item)
6002 {
6003 int ret;
6004 struct extent_buffer *leaf = path->nodes[0];
6005 char *tmp;
6006 size_t max_size;
6007 unsigned long inline_size;
6008 unsigned long ptr;
6009 int compress_type;
6010
6011 WARN_ON(pg_offset != 0);
6012 compress_type = btrfs_file_extent_compression(leaf, item);
6013 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6014 inline_size = btrfs_file_extent_inline_item_len(leaf,
6015 btrfs_item_nr(leaf, path->slots[0]));
6016 tmp = kmalloc(inline_size, GFP_NOFS);
6017 if (!tmp)
6018 return -ENOMEM;
6019 ptr = btrfs_file_extent_inline_start(item);
6020
6021 read_extent_buffer(leaf, tmp, ptr, inline_size);
6022
6023 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
6024 ret = btrfs_decompress(compress_type, tmp, page,
6025 extent_offset, inline_size, max_size);
6026 if (ret) {
6027 char *kaddr = kmap_atomic(page);
6028 unsigned long copy_size = min_t(u64,
6029 PAGE_CACHE_SIZE - pg_offset,
6030 max_size - extent_offset);
6031 memset(kaddr + pg_offset, 0, copy_size);
6032 kunmap_atomic(kaddr);
6033 }
6034 kfree(tmp);
6035 return 0;
6036 }
6037
6038 /*
6039 * a bit scary, this does extent mapping from logical file offset to the disk.
6040 * the ugly parts come from merging extents from the disk with the in-ram
6041 * representation. This gets more complex because of the data=ordered code,
6042 * where the in-ram extents might be locked pending data=ordered completion.
6043 *
6044 * This also copies inline extents directly into the page.
6045 */
6046
6047 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
6048 size_t pg_offset, u64 start, u64 len,
6049 int create)
6050 {
6051 int ret;
6052 int err = 0;
6053 u64 bytenr;
6054 u64 extent_start = 0;
6055 u64 extent_end = 0;
6056 u64 objectid = btrfs_ino(inode);
6057 u32 found_type;
6058 struct btrfs_path *path = NULL;
6059 struct btrfs_root *root = BTRFS_I(inode)->root;
6060 struct btrfs_file_extent_item *item;
6061 struct extent_buffer *leaf;
6062 struct btrfs_key found_key;
6063 struct extent_map *em = NULL;
6064 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
6065 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6066 struct btrfs_trans_handle *trans = NULL;
6067 int compress_type;
6068
6069 again:
6070 read_lock(&em_tree->lock);
6071 em = lookup_extent_mapping(em_tree, start, len);
6072 if (em)
6073 em->bdev = root->fs_info->fs_devices->latest_bdev;
6074 read_unlock(&em_tree->lock);
6075
6076 if (em) {
6077 if (em->start > start || em->start + em->len <= start)
6078 free_extent_map(em);
6079 else if (em->block_start == EXTENT_MAP_INLINE && page)
6080 free_extent_map(em);
6081 else
6082 goto out;
6083 }
6084 em = alloc_extent_map();
6085 if (!em) {
6086 err = -ENOMEM;
6087 goto out;
6088 }
6089 em->bdev = root->fs_info->fs_devices->latest_bdev;
6090 em->start = EXTENT_MAP_HOLE;
6091 em->orig_start = EXTENT_MAP_HOLE;
6092 em->len = (u64)-1;
6093 em->block_len = (u64)-1;
6094
6095 if (!path) {
6096 path = btrfs_alloc_path();
6097 if (!path) {
6098 err = -ENOMEM;
6099 goto out;
6100 }
6101 /*
6102 * Chances are we'll be called again, so go ahead and do
6103 * readahead
6104 */
6105 path->reada = 1;
6106 }
6107
6108 ret = btrfs_lookup_file_extent(trans, root, path,
6109 objectid, start, trans != NULL);
6110 if (ret < 0) {
6111 err = ret;
6112 goto out;
6113 }
6114
6115 if (ret != 0) {
6116 if (path->slots[0] == 0)
6117 goto not_found;
6118 path->slots[0]--;
6119 }
6120
6121 leaf = path->nodes[0];
6122 item = btrfs_item_ptr(leaf, path->slots[0],
6123 struct btrfs_file_extent_item);
6124 /* are we inside the extent that was found? */
6125 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6126 found_type = btrfs_key_type(&found_key);
6127 if (found_key.objectid != objectid ||
6128 found_type != BTRFS_EXTENT_DATA_KEY) {
6129 goto not_found;
6130 }
6131
6132 found_type = btrfs_file_extent_type(leaf, item);
6133 extent_start = found_key.offset;
6134 compress_type = btrfs_file_extent_compression(leaf, item);
6135 if (found_type == BTRFS_FILE_EXTENT_REG ||
6136 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6137 extent_end = extent_start +
6138 btrfs_file_extent_num_bytes(leaf, item);
6139 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6140 size_t size;
6141 size = btrfs_file_extent_inline_len(leaf, item);
6142 extent_end = ALIGN(extent_start + size, root->sectorsize);
6143 }
6144
6145 if (start >= extent_end) {
6146 path->slots[0]++;
6147 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6148 ret = btrfs_next_leaf(root, path);
6149 if (ret < 0) {
6150 err = ret;
6151 goto out;
6152 }
6153 if (ret > 0)
6154 goto not_found;
6155 leaf = path->nodes[0];
6156 }
6157 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6158 if (found_key.objectid != objectid ||
6159 found_key.type != BTRFS_EXTENT_DATA_KEY)
6160 goto not_found;
6161 if (start + len <= found_key.offset)
6162 goto not_found;
6163 em->start = start;
6164 em->orig_start = start;
6165 em->len = found_key.offset - start;
6166 goto not_found_em;
6167 }
6168
6169 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, item);
6170 if (found_type == BTRFS_FILE_EXTENT_REG ||
6171 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6172 em->start = extent_start;
6173 em->len = extent_end - extent_start;
6174 em->orig_start = extent_start -
6175 btrfs_file_extent_offset(leaf, item);
6176 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf,
6177 item);
6178 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
6179 if (bytenr == 0) {
6180 em->block_start = EXTENT_MAP_HOLE;
6181 goto insert;
6182 }
6183 if (compress_type != BTRFS_COMPRESS_NONE) {
6184 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
6185 em->compress_type = compress_type;
6186 em->block_start = bytenr;
6187 em->block_len = em->orig_block_len;
6188 } else {
6189 bytenr += btrfs_file_extent_offset(leaf, item);
6190 em->block_start = bytenr;
6191 em->block_len = em->len;
6192 if (found_type == BTRFS_FILE_EXTENT_PREALLOC)
6193 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
6194 }
6195 goto insert;
6196 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6197 unsigned long ptr;
6198 char *map;
6199 size_t size;
6200 size_t extent_offset;
6201 size_t copy_size;
6202
6203 em->block_start = EXTENT_MAP_INLINE;
6204 if (!page || create) {
6205 em->start = extent_start;
6206 em->len = extent_end - extent_start;
6207 goto out;
6208 }
6209
6210 size = btrfs_file_extent_inline_len(leaf, item);
6211 extent_offset = page_offset(page) + pg_offset - extent_start;
6212 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
6213 size - extent_offset);
6214 em->start = extent_start + extent_offset;
6215 em->len = ALIGN(copy_size, root->sectorsize);
6216 em->orig_block_len = em->len;
6217 em->orig_start = em->start;
6218 if (compress_type) {
6219 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
6220 em->compress_type = compress_type;
6221 }
6222 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6223 if (create == 0 && !PageUptodate(page)) {
6224 if (btrfs_file_extent_compression(leaf, item) !=
6225 BTRFS_COMPRESS_NONE) {
6226 ret = uncompress_inline(path, inode, page,
6227 pg_offset,
6228 extent_offset, item);
6229 BUG_ON(ret); /* -ENOMEM */
6230 } else {
6231 map = kmap(page);
6232 read_extent_buffer(leaf, map + pg_offset, ptr,
6233 copy_size);
6234 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
6235 memset(map + pg_offset + copy_size, 0,
6236 PAGE_CACHE_SIZE - pg_offset -
6237 copy_size);
6238 }
6239 kunmap(page);
6240 }
6241 flush_dcache_page(page);
6242 } else if (create && PageUptodate(page)) {
6243 BUG();
6244 if (!trans) {
6245 kunmap(page);
6246 free_extent_map(em);
6247 em = NULL;
6248
6249 btrfs_release_path(path);
6250 trans = btrfs_join_transaction(root);
6251
6252 if (IS_ERR(trans))
6253 return ERR_CAST(trans);
6254 goto again;
6255 }
6256 map = kmap(page);
6257 write_extent_buffer(leaf, map + pg_offset, ptr,
6258 copy_size);
6259 kunmap(page);
6260 btrfs_mark_buffer_dirty(leaf);
6261 }
6262 set_extent_uptodate(io_tree, em->start,
6263 extent_map_end(em) - 1, NULL, GFP_NOFS);
6264 goto insert;
6265 } else {
6266 WARN(1, KERN_ERR "btrfs unknown found_type %d\n", found_type);
6267 }
6268 not_found:
6269 em->start = start;
6270 em->orig_start = start;
6271 em->len = len;
6272 not_found_em:
6273 em->block_start = EXTENT_MAP_HOLE;
6274 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
6275 insert:
6276 btrfs_release_path(path);
6277 if (em->start > start || extent_map_end(em) <= start) {
6278 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
6279 (unsigned long long)em->start,
6280 (unsigned long long)em->len,
6281 (unsigned long long)start,
6282 (unsigned long long)len);
6283 err = -EIO;
6284 goto out;
6285 }
6286
6287 err = 0;
6288 write_lock(&em_tree->lock);
6289 ret = add_extent_mapping(em_tree, em, 0);
6290 /* it is possible that someone inserted the extent into the tree
6291 * while we had the lock dropped. It is also possible that
6292 * an overlapping map exists in the tree
6293 */
6294 if (ret == -EEXIST) {
6295 struct extent_map *existing;
6296
6297 ret = 0;
6298
6299 existing = lookup_extent_mapping(em_tree, start, len);
6300 if (existing && (existing->start > start ||
6301 existing->start + existing->len <= start)) {
6302 free_extent_map(existing);
6303 existing = NULL;
6304 }
6305 if (!existing) {
6306 existing = lookup_extent_mapping(em_tree, em->start,
6307 em->len);
6308 if (existing) {
6309 err = merge_extent_mapping(em_tree, existing,
6310 em, start,
6311 root->sectorsize);
6312 free_extent_map(existing);
6313 if (err) {
6314 free_extent_map(em);
6315 em = NULL;
6316 }
6317 } else {
6318 err = -EIO;
6319 free_extent_map(em);
6320 em = NULL;
6321 }
6322 } else {
6323 free_extent_map(em);
6324 em = existing;
6325 err = 0;
6326 }
6327 }
6328 write_unlock(&em_tree->lock);
6329 out:
6330
6331 if (em)
6332 trace_btrfs_get_extent(root, em);
6333
6334 if (path)
6335 btrfs_free_path(path);
6336 if (trans) {
6337 ret = btrfs_end_transaction(trans, root);
6338 if (!err)
6339 err = ret;
6340 }
6341 if (err) {
6342 free_extent_map(em);
6343 return ERR_PTR(err);
6344 }
6345 BUG_ON(!em); /* Error is always set */
6346 return em;
6347 }
6348
6349 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
6350 size_t pg_offset, u64 start, u64 len,
6351 int create)
6352 {
6353 struct extent_map *em;
6354 struct extent_map *hole_em = NULL;
6355 u64 range_start = start;
6356 u64 end;
6357 u64 found;
6358 u64 found_end;
6359 int err = 0;
6360
6361 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
6362 if (IS_ERR(em))
6363 return em;
6364 if (em) {
6365 /*
6366 * if our em maps to
6367 * - a hole or
6368 * - a pre-alloc extent,
6369 * there might actually be delalloc bytes behind it.
6370 */
6371 if (em->block_start != EXTENT_MAP_HOLE &&
6372 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6373 return em;
6374 else
6375 hole_em = em;
6376 }
6377
6378 /* check to see if we've wrapped (len == -1 or similar) */
6379 end = start + len;
6380 if (end < start)
6381 end = (u64)-1;
6382 else
6383 end -= 1;
6384
6385 em = NULL;
6386
6387 /* ok, we didn't find anything, lets look for delalloc */
6388 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
6389 end, len, EXTENT_DELALLOC, 1);
6390 found_end = range_start + found;
6391 if (found_end < range_start)
6392 found_end = (u64)-1;
6393
6394 /*
6395 * we didn't find anything useful, return
6396 * the original results from get_extent()
6397 */
6398 if (range_start > end || found_end <= start) {
6399 em = hole_em;
6400 hole_em = NULL;
6401 goto out;
6402 }
6403
6404 /* adjust the range_start to make sure it doesn't
6405 * go backwards from the start they passed in
6406 */
6407 range_start = max(start,range_start);
6408 found = found_end - range_start;
6409
6410 if (found > 0) {
6411 u64 hole_start = start;
6412 u64 hole_len = len;
6413
6414 em = alloc_extent_map();
6415 if (!em) {
6416 err = -ENOMEM;
6417 goto out;
6418 }
6419 /*
6420 * when btrfs_get_extent can't find anything it
6421 * returns one huge hole
6422 *
6423 * make sure what it found really fits our range, and
6424 * adjust to make sure it is based on the start from
6425 * the caller
6426 */
6427 if (hole_em) {
6428 u64 calc_end = extent_map_end(hole_em);
6429
6430 if (calc_end <= start || (hole_em->start > end)) {
6431 free_extent_map(hole_em);
6432 hole_em = NULL;
6433 } else {
6434 hole_start = max(hole_em->start, start);
6435 hole_len = calc_end - hole_start;
6436 }
6437 }
6438 em->bdev = NULL;
6439 if (hole_em && range_start > hole_start) {
6440 /* our hole starts before our delalloc, so we
6441 * have to return just the parts of the hole
6442 * that go until the delalloc starts
6443 */
6444 em->len = min(hole_len,
6445 range_start - hole_start);
6446 em->start = hole_start;
6447 em->orig_start = hole_start;
6448 /*
6449 * don't adjust block start at all,
6450 * it is fixed at EXTENT_MAP_HOLE
6451 */
6452 em->block_start = hole_em->block_start;
6453 em->block_len = hole_len;
6454 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
6455 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
6456 } else {
6457 em->start = range_start;
6458 em->len = found;
6459 em->orig_start = range_start;
6460 em->block_start = EXTENT_MAP_DELALLOC;
6461 em->block_len = found;
6462 }
6463 } else if (hole_em) {
6464 return hole_em;
6465 }
6466 out:
6467
6468 free_extent_map(hole_em);
6469 if (err) {
6470 free_extent_map(em);
6471 return ERR_PTR(err);
6472 }
6473 return em;
6474 }
6475
6476 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
6477 u64 start, u64 len)
6478 {
6479 struct btrfs_root *root = BTRFS_I(inode)->root;
6480 struct btrfs_trans_handle *trans;
6481 struct extent_map *em;
6482 struct btrfs_key ins;
6483 u64 alloc_hint;
6484 int ret;
6485
6486 trans = btrfs_join_transaction(root);
6487 if (IS_ERR(trans))
6488 return ERR_CAST(trans);
6489
6490 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
6491
6492 alloc_hint = get_extent_allocation_hint(inode, start, len);
6493 ret = btrfs_reserve_extent(trans, root, len, root->sectorsize, 0,
6494 alloc_hint, &ins, 1);
6495 if (ret) {
6496 em = ERR_PTR(ret);
6497 goto out;
6498 }
6499
6500 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
6501 ins.offset, ins.offset, ins.offset, 0);
6502 if (IS_ERR(em))
6503 goto out;
6504
6505 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
6506 ins.offset, ins.offset, 0);
6507 if (ret) {
6508 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
6509 em = ERR_PTR(ret);
6510 }
6511 out:
6512 btrfs_end_transaction(trans, root);
6513 return em;
6514 }
6515
6516 /*
6517 * returns 1 when the nocow is safe, < 1 on error, 0 if the
6518 * block must be cow'd
6519 */
6520 static noinline int can_nocow_odirect(struct btrfs_trans_handle *trans,
6521 struct inode *inode, u64 offset, u64 *len,
6522 u64 *orig_start, u64 *orig_block_len,
6523 u64 *ram_bytes)
6524 {
6525 struct btrfs_path *path;
6526 int ret;
6527 struct extent_buffer *leaf;
6528 struct btrfs_root *root = BTRFS_I(inode)->root;
6529 struct btrfs_file_extent_item *fi;
6530 struct btrfs_key key;
6531 u64 disk_bytenr;
6532 u64 backref_offset;
6533 u64 extent_end;
6534 u64 num_bytes;
6535 int slot;
6536 int found_type;
6537
6538 path = btrfs_alloc_path();
6539 if (!path)
6540 return -ENOMEM;
6541
6542 ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(inode),
6543 offset, 0);
6544 if (ret < 0)
6545 goto out;
6546
6547 slot = path->slots[0];
6548 if (ret == 1) {
6549 if (slot == 0) {
6550 /* can't find the item, must cow */
6551 ret = 0;
6552 goto out;
6553 }
6554 slot--;
6555 }
6556 ret = 0;
6557 leaf = path->nodes[0];
6558 btrfs_item_key_to_cpu(leaf, &key, slot);
6559 if (key.objectid != btrfs_ino(inode) ||
6560 key.type != BTRFS_EXTENT_DATA_KEY) {
6561 /* not our file or wrong item type, must cow */
6562 goto out;
6563 }
6564
6565 if (key.offset > offset) {
6566 /* Wrong offset, must cow */
6567 goto out;
6568 }
6569
6570 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
6571 found_type = btrfs_file_extent_type(leaf, fi);
6572 if (found_type != BTRFS_FILE_EXTENT_REG &&
6573 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
6574 /* not a regular extent, must cow */
6575 goto out;
6576 }
6577 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
6578 backref_offset = btrfs_file_extent_offset(leaf, fi);
6579
6580 *orig_start = key.offset - backref_offset;
6581 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
6582 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
6583
6584 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
6585 if (extent_end < offset + *len) {
6586 /* extent doesn't include our full range, must cow */
6587 goto out;
6588 }
6589
6590 if (btrfs_extent_readonly(root, disk_bytenr))
6591 goto out;
6592
6593 /*
6594 * look for other files referencing this extent, if we
6595 * find any we must cow
6596 */
6597 if (btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
6598 key.offset - backref_offset, disk_bytenr))
6599 goto out;
6600
6601 /*
6602 * adjust disk_bytenr and num_bytes to cover just the bytes
6603 * in this extent we are about to write. If there
6604 * are any csums in that range we have to cow in order
6605 * to keep the csums correct
6606 */
6607 disk_bytenr += backref_offset;
6608 disk_bytenr += offset - key.offset;
6609 num_bytes = min(offset + *len, extent_end) - offset;
6610 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
6611 goto out;
6612 /*
6613 * all of the above have passed, it is safe to overwrite this extent
6614 * without cow
6615 */
6616 *len = num_bytes;
6617 ret = 1;
6618 out:
6619 btrfs_free_path(path);
6620 return ret;
6621 }
6622
6623 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
6624 struct extent_state **cached_state, int writing)
6625 {
6626 struct btrfs_ordered_extent *ordered;
6627 int ret = 0;
6628
6629 while (1) {
6630 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6631 0, cached_state);
6632 /*
6633 * We're concerned with the entire range that we're going to be
6634 * doing DIO to, so we need to make sure theres no ordered
6635 * extents in this range.
6636 */
6637 ordered = btrfs_lookup_ordered_range(inode, lockstart,
6638 lockend - lockstart + 1);
6639
6640 /*
6641 * We need to make sure there are no buffered pages in this
6642 * range either, we could have raced between the invalidate in
6643 * generic_file_direct_write and locking the extent. The
6644 * invalidate needs to happen so that reads after a write do not
6645 * get stale data.
6646 */
6647 if (!ordered && (!writing ||
6648 !test_range_bit(&BTRFS_I(inode)->io_tree,
6649 lockstart, lockend, EXTENT_UPTODATE, 0,
6650 *cached_state)))
6651 break;
6652
6653 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6654 cached_state, GFP_NOFS);
6655
6656 if (ordered) {
6657 btrfs_start_ordered_extent(inode, ordered, 1);
6658 btrfs_put_ordered_extent(ordered);
6659 } else {
6660 /* Screw you mmap */
6661 ret = filemap_write_and_wait_range(inode->i_mapping,
6662 lockstart,
6663 lockend);
6664 if (ret)
6665 break;
6666
6667 /*
6668 * If we found a page that couldn't be invalidated just
6669 * fall back to buffered.
6670 */
6671 ret = invalidate_inode_pages2_range(inode->i_mapping,
6672 lockstart >> PAGE_CACHE_SHIFT,
6673 lockend >> PAGE_CACHE_SHIFT);
6674 if (ret)
6675 break;
6676 }
6677
6678 cond_resched();
6679 }
6680
6681 return ret;
6682 }
6683
6684 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
6685 u64 len, u64 orig_start,
6686 u64 block_start, u64 block_len,
6687 u64 orig_block_len, u64 ram_bytes,
6688 int type)
6689 {
6690 struct extent_map_tree *em_tree;
6691 struct extent_map *em;
6692 struct btrfs_root *root = BTRFS_I(inode)->root;
6693 int ret;
6694
6695 em_tree = &BTRFS_I(inode)->extent_tree;
6696 em = alloc_extent_map();
6697 if (!em)
6698 return ERR_PTR(-ENOMEM);
6699
6700 em->start = start;
6701 em->orig_start = orig_start;
6702 em->mod_start = start;
6703 em->mod_len = len;
6704 em->len = len;
6705 em->block_len = block_len;
6706 em->block_start = block_start;
6707 em->bdev = root->fs_info->fs_devices->latest_bdev;
6708 em->orig_block_len = orig_block_len;
6709 em->ram_bytes = ram_bytes;
6710 em->generation = -1;
6711 set_bit(EXTENT_FLAG_PINNED, &em->flags);
6712 if (type == BTRFS_ORDERED_PREALLOC)
6713 set_bit(EXTENT_FLAG_FILLING, &em->flags);
6714
6715 do {
6716 btrfs_drop_extent_cache(inode, em->start,
6717 em->start + em->len - 1, 0);
6718 write_lock(&em_tree->lock);
6719 ret = add_extent_mapping(em_tree, em, 1);
6720 write_unlock(&em_tree->lock);
6721 } while (ret == -EEXIST);
6722
6723 if (ret) {
6724 free_extent_map(em);
6725 return ERR_PTR(ret);
6726 }
6727
6728 return em;
6729 }
6730
6731
6732 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
6733 struct buffer_head *bh_result, int create)
6734 {
6735 struct extent_map *em;
6736 struct btrfs_root *root = BTRFS_I(inode)->root;
6737 struct extent_state *cached_state = NULL;
6738 u64 start = iblock << inode->i_blkbits;
6739 u64 lockstart, lockend;
6740 u64 len = bh_result->b_size;
6741 struct btrfs_trans_handle *trans;
6742 int unlock_bits = EXTENT_LOCKED;
6743 int ret = 0;
6744
6745 if (create)
6746 unlock_bits |= EXTENT_DELALLOC | EXTENT_DIRTY;
6747 else
6748 len = min_t(u64, len, root->sectorsize);
6749
6750 lockstart = start;
6751 lockend = start + len - 1;
6752
6753 /*
6754 * If this errors out it's because we couldn't invalidate pagecache for
6755 * this range and we need to fallback to buffered.
6756 */
6757 if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create))
6758 return -ENOTBLK;
6759
6760 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
6761 if (IS_ERR(em)) {
6762 ret = PTR_ERR(em);
6763 goto unlock_err;
6764 }
6765
6766 /*
6767 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
6768 * io. INLINE is special, and we could probably kludge it in here, but
6769 * it's still buffered so for safety lets just fall back to the generic
6770 * buffered path.
6771 *
6772 * For COMPRESSED we _have_ to read the entire extent in so we can
6773 * decompress it, so there will be buffering required no matter what we
6774 * do, so go ahead and fallback to buffered.
6775 *
6776 * We return -ENOTBLK because thats what makes DIO go ahead and go back
6777 * to buffered IO. Don't blame me, this is the price we pay for using
6778 * the generic code.
6779 */
6780 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
6781 em->block_start == EXTENT_MAP_INLINE) {
6782 free_extent_map(em);
6783 ret = -ENOTBLK;
6784 goto unlock_err;
6785 }
6786
6787 /* Just a good old fashioned hole, return */
6788 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
6789 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
6790 free_extent_map(em);
6791 goto unlock_err;
6792 }
6793
6794 /*
6795 * We don't allocate a new extent in the following cases
6796 *
6797 * 1) The inode is marked as NODATACOW. In this case we'll just use the
6798 * existing extent.
6799 * 2) The extent is marked as PREALLOC. We're good to go here and can
6800 * just use the extent.
6801 *
6802 */
6803 if (!create) {
6804 len = min(len, em->len - (start - em->start));
6805 lockstart = start + len;
6806 goto unlock;
6807 }
6808
6809 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
6810 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
6811 em->block_start != EXTENT_MAP_HOLE)) {
6812 int type;
6813 int ret;
6814 u64 block_start, orig_start, orig_block_len, ram_bytes;
6815
6816 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6817 type = BTRFS_ORDERED_PREALLOC;
6818 else
6819 type = BTRFS_ORDERED_NOCOW;
6820 len = min(len, em->len - (start - em->start));
6821 block_start = em->block_start + (start - em->start);
6822
6823 /*
6824 * we're not going to log anything, but we do need
6825 * to make sure the current transaction stays open
6826 * while we look for nocow cross refs
6827 */
6828 trans = btrfs_join_transaction(root);
6829 if (IS_ERR(trans))
6830 goto must_cow;
6831
6832 if (can_nocow_odirect(trans, inode, start, &len, &orig_start,
6833 &orig_block_len, &ram_bytes) == 1) {
6834 if (type == BTRFS_ORDERED_PREALLOC) {
6835 free_extent_map(em);
6836 em = create_pinned_em(inode, start, len,
6837 orig_start,
6838 block_start, len,
6839 orig_block_len,
6840 ram_bytes, type);
6841 if (IS_ERR(em)) {
6842 btrfs_end_transaction(trans, root);
6843 goto unlock_err;
6844 }
6845 }
6846
6847 ret = btrfs_add_ordered_extent_dio(inode, start,
6848 block_start, len, len, type);
6849 btrfs_end_transaction(trans, root);
6850 if (ret) {
6851 free_extent_map(em);
6852 goto unlock_err;
6853 }
6854 goto unlock;
6855 }
6856 btrfs_end_transaction(trans, root);
6857 }
6858 must_cow:
6859 /*
6860 * this will cow the extent, reset the len in case we changed
6861 * it above
6862 */
6863 len = bh_result->b_size;
6864 free_extent_map(em);
6865 em = btrfs_new_extent_direct(inode, start, len);
6866 if (IS_ERR(em)) {
6867 ret = PTR_ERR(em);
6868 goto unlock_err;
6869 }
6870 len = min(len, em->len - (start - em->start));
6871 unlock:
6872 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
6873 inode->i_blkbits;
6874 bh_result->b_size = len;
6875 bh_result->b_bdev = em->bdev;
6876 set_buffer_mapped(bh_result);
6877 if (create) {
6878 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6879 set_buffer_new(bh_result);
6880
6881 /*
6882 * Need to update the i_size under the extent lock so buffered
6883 * readers will get the updated i_size when we unlock.
6884 */
6885 if (start + len > i_size_read(inode))
6886 i_size_write(inode, start + len);
6887
6888 spin_lock(&BTRFS_I(inode)->lock);
6889 BTRFS_I(inode)->outstanding_extents++;
6890 spin_unlock(&BTRFS_I(inode)->lock);
6891
6892 ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6893 lockstart + len - 1, EXTENT_DELALLOC, NULL,
6894 &cached_state, GFP_NOFS);
6895 BUG_ON(ret);
6896 }
6897
6898 /*
6899 * In the case of write we need to clear and unlock the entire range,
6900 * in the case of read we need to unlock only the end area that we
6901 * aren't using if there is any left over space.
6902 */
6903 if (lockstart < lockend) {
6904 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6905 lockend, unlock_bits, 1, 0,
6906 &cached_state, GFP_NOFS);
6907 } else {
6908 free_extent_state(cached_state);
6909 }
6910
6911 free_extent_map(em);
6912
6913 return 0;
6914
6915 unlock_err:
6916 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6917 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
6918 return ret;
6919 }
6920
6921 struct btrfs_dio_private {
6922 struct inode *inode;
6923 u64 logical_offset;
6924 u64 disk_bytenr;
6925 u64 bytes;
6926 void *private;
6927
6928 /* number of bios pending for this dio */
6929 atomic_t pending_bios;
6930
6931 /* IO errors */
6932 int errors;
6933
6934 struct bio *orig_bio;
6935 };
6936
6937 static void btrfs_endio_direct_read(struct bio *bio, int err)
6938 {
6939 struct btrfs_dio_private *dip = bio->bi_private;
6940 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
6941 struct bio_vec *bvec = bio->bi_io_vec;
6942 struct inode *inode = dip->inode;
6943 struct btrfs_root *root = BTRFS_I(inode)->root;
6944 u64 start;
6945
6946 start = dip->logical_offset;
6947 do {
6948 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
6949 struct page *page = bvec->bv_page;
6950 char *kaddr;
6951 u32 csum = ~(u32)0;
6952 u64 private = ~(u32)0;
6953 unsigned long flags;
6954
6955 if (get_state_private(&BTRFS_I(inode)->io_tree,
6956 start, &private))
6957 goto failed;
6958 local_irq_save(flags);
6959 kaddr = kmap_atomic(page);
6960 csum = btrfs_csum_data(kaddr + bvec->bv_offset,
6961 csum, bvec->bv_len);
6962 btrfs_csum_final(csum, (char *)&csum);
6963 kunmap_atomic(kaddr);
6964 local_irq_restore(flags);
6965
6966 flush_dcache_page(bvec->bv_page);
6967 if (csum != private) {
6968 failed:
6969 btrfs_err(root->fs_info, "csum failed ino %llu off %llu csum %u private %u",
6970 (unsigned long long)btrfs_ino(inode),
6971 (unsigned long long)start,
6972 csum, (unsigned)private);
6973 err = -EIO;
6974 }
6975 }
6976
6977 start += bvec->bv_len;
6978 bvec++;
6979 } while (bvec <= bvec_end);
6980
6981 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
6982 dip->logical_offset + dip->bytes - 1);
6983 bio->bi_private = dip->private;
6984
6985 kfree(dip);
6986
6987 /* If we had a csum failure make sure to clear the uptodate flag */
6988 if (err)
6989 clear_bit(BIO_UPTODATE, &bio->bi_flags);
6990 dio_end_io(bio, err);
6991 }
6992
6993 static void btrfs_endio_direct_write(struct bio *bio, int err)
6994 {
6995 struct btrfs_dio_private *dip = bio->bi_private;
6996 struct inode *inode = dip->inode;
6997 struct btrfs_root *root = BTRFS_I(inode)->root;
6998 struct btrfs_ordered_extent *ordered = NULL;
6999 u64 ordered_offset = dip->logical_offset;
7000 u64 ordered_bytes = dip->bytes;
7001 int ret;
7002
7003 if (err)
7004 goto out_done;
7005 again:
7006 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
7007 &ordered_offset,
7008 ordered_bytes, !err);
7009 if (!ret)
7010 goto out_test;
7011
7012 ordered->work.func = finish_ordered_fn;
7013 ordered->work.flags = 0;
7014 btrfs_queue_worker(&root->fs_info->endio_write_workers,
7015 &ordered->work);
7016 out_test:
7017 /*
7018 * our bio might span multiple ordered extents. If we haven't
7019 * completed the accounting for the whole dio, go back and try again
7020 */
7021 if (ordered_offset < dip->logical_offset + dip->bytes) {
7022 ordered_bytes = dip->logical_offset + dip->bytes -
7023 ordered_offset;
7024 ordered = NULL;
7025 goto again;
7026 }
7027 out_done:
7028 bio->bi_private = dip->private;
7029
7030 kfree(dip);
7031
7032 /* If we had an error make sure to clear the uptodate flag */
7033 if (err)
7034 clear_bit(BIO_UPTODATE, &bio->bi_flags);
7035 dio_end_io(bio, err);
7036 }
7037
7038 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
7039 struct bio *bio, int mirror_num,
7040 unsigned long bio_flags, u64 offset)
7041 {
7042 int ret;
7043 struct btrfs_root *root = BTRFS_I(inode)->root;
7044 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
7045 BUG_ON(ret); /* -ENOMEM */
7046 return 0;
7047 }
7048
7049 static void btrfs_end_dio_bio(struct bio *bio, int err)
7050 {
7051 struct btrfs_dio_private *dip = bio->bi_private;
7052
7053 if (err) {
7054 printk(KERN_ERR "btrfs direct IO failed ino %llu rw %lu "
7055 "sector %#Lx len %u err no %d\n",
7056 (unsigned long long)btrfs_ino(dip->inode), bio->bi_rw,
7057 (unsigned long long)bio->bi_sector, bio->bi_size, err);
7058 dip->errors = 1;
7059
7060 /*
7061 * before atomic variable goto zero, we must make sure
7062 * dip->errors is perceived to be set.
7063 */
7064 smp_mb__before_atomic_dec();
7065 }
7066
7067 /* if there are more bios still pending for this dio, just exit */
7068 if (!atomic_dec_and_test(&dip->pending_bios))
7069 goto out;
7070
7071 if (dip->errors)
7072 bio_io_error(dip->orig_bio);
7073 else {
7074 set_bit(BIO_UPTODATE, &dip->orig_bio->bi_flags);
7075 bio_endio(dip->orig_bio, 0);
7076 }
7077 out:
7078 bio_put(bio);
7079 }
7080
7081 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
7082 u64 first_sector, gfp_t gfp_flags)
7083 {
7084 int nr_vecs = bio_get_nr_vecs(bdev);
7085 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
7086 }
7087
7088 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
7089 int rw, u64 file_offset, int skip_sum,
7090 int async_submit)
7091 {
7092 int write = rw & REQ_WRITE;
7093 struct btrfs_root *root = BTRFS_I(inode)->root;
7094 int ret;
7095
7096 if (async_submit)
7097 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
7098
7099 bio_get(bio);
7100
7101 if (!write) {
7102 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
7103 if (ret)
7104 goto err;
7105 }
7106
7107 if (skip_sum)
7108 goto map;
7109
7110 if (write && async_submit) {
7111 ret = btrfs_wq_submit_bio(root->fs_info,
7112 inode, rw, bio, 0, 0,
7113 file_offset,
7114 __btrfs_submit_bio_start_direct_io,
7115 __btrfs_submit_bio_done);
7116 goto err;
7117 } else if (write) {
7118 /*
7119 * If we aren't doing async submit, calculate the csum of the
7120 * bio now.
7121 */
7122 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
7123 if (ret)
7124 goto err;
7125 } else if (!skip_sum) {
7126 ret = btrfs_lookup_bio_sums_dio(root, inode, bio, file_offset);
7127 if (ret)
7128 goto err;
7129 }
7130
7131 map:
7132 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
7133 err:
7134 bio_put(bio);
7135 return ret;
7136 }
7137
7138 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
7139 int skip_sum)
7140 {
7141 struct inode *inode = dip->inode;
7142 struct btrfs_root *root = BTRFS_I(inode)->root;
7143 struct bio *bio;
7144 struct bio *orig_bio = dip->orig_bio;
7145 struct bio_vec *bvec = orig_bio->bi_io_vec;
7146 u64 start_sector = orig_bio->bi_sector;
7147 u64 file_offset = dip->logical_offset;
7148 u64 submit_len = 0;
7149 u64 map_length;
7150 int nr_pages = 0;
7151 int ret = 0;
7152 int async_submit = 0;
7153
7154 map_length = orig_bio->bi_size;
7155 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
7156 &map_length, NULL, 0);
7157 if (ret) {
7158 bio_put(orig_bio);
7159 return -EIO;
7160 }
7161 if (map_length >= orig_bio->bi_size) {
7162 bio = orig_bio;
7163 goto submit;
7164 }
7165
7166 /* async crcs make it difficult to collect full stripe writes. */
7167 if (btrfs_get_alloc_profile(root, 1) &
7168 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6))
7169 async_submit = 0;
7170 else
7171 async_submit = 1;
7172
7173 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
7174 if (!bio)
7175 return -ENOMEM;
7176 bio->bi_private = dip;
7177 bio->bi_end_io = btrfs_end_dio_bio;
7178 atomic_inc(&dip->pending_bios);
7179
7180 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
7181 if (unlikely(map_length < submit_len + bvec->bv_len ||
7182 bio_add_page(bio, bvec->bv_page, bvec->bv_len,
7183 bvec->bv_offset) < bvec->bv_len)) {
7184 /*
7185 * inc the count before we submit the bio so
7186 * we know the end IO handler won't happen before
7187 * we inc the count. Otherwise, the dip might get freed
7188 * before we're done setting it up
7189 */
7190 atomic_inc(&dip->pending_bios);
7191 ret = __btrfs_submit_dio_bio(bio, inode, rw,
7192 file_offset, skip_sum,
7193 async_submit);
7194 if (ret) {
7195 bio_put(bio);
7196 atomic_dec(&dip->pending_bios);
7197 goto out_err;
7198 }
7199
7200 start_sector += submit_len >> 9;
7201 file_offset += submit_len;
7202
7203 submit_len = 0;
7204 nr_pages = 0;
7205
7206 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
7207 start_sector, GFP_NOFS);
7208 if (!bio)
7209 goto out_err;
7210 bio->bi_private = dip;
7211 bio->bi_end_io = btrfs_end_dio_bio;
7212
7213 map_length = orig_bio->bi_size;
7214 ret = btrfs_map_block(root->fs_info, rw,
7215 start_sector << 9,
7216 &map_length, NULL, 0);
7217 if (ret) {
7218 bio_put(bio);
7219 goto out_err;
7220 }
7221 } else {
7222 submit_len += bvec->bv_len;
7223 nr_pages ++;
7224 bvec++;
7225 }
7226 }
7227
7228 submit:
7229 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
7230 async_submit);
7231 if (!ret)
7232 return 0;
7233
7234 bio_put(bio);
7235 out_err:
7236 dip->errors = 1;
7237 /*
7238 * before atomic variable goto zero, we must
7239 * make sure dip->errors is perceived to be set.
7240 */
7241 smp_mb__before_atomic_dec();
7242 if (atomic_dec_and_test(&dip->pending_bios))
7243 bio_io_error(dip->orig_bio);
7244
7245 /* bio_end_io() will handle error, so we needn't return it */
7246 return 0;
7247 }
7248
7249 static void btrfs_submit_direct(int rw, struct bio *bio, struct inode *inode,
7250 loff_t file_offset)
7251 {
7252 struct btrfs_root *root = BTRFS_I(inode)->root;
7253 struct btrfs_dio_private *dip;
7254 struct bio_vec *bvec = bio->bi_io_vec;
7255 int skip_sum;
7256 int write = rw & REQ_WRITE;
7257 int ret = 0;
7258
7259 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
7260
7261 dip = kmalloc(sizeof(*dip), GFP_NOFS);
7262 if (!dip) {
7263 ret = -ENOMEM;
7264 goto free_ordered;
7265 }
7266
7267 dip->private = bio->bi_private;
7268 dip->inode = inode;
7269 dip->logical_offset = file_offset;
7270
7271 dip->bytes = 0;
7272 do {
7273 dip->bytes += bvec->bv_len;
7274 bvec++;
7275 } while (bvec <= (bio->bi_io_vec + bio->bi_vcnt - 1));
7276
7277 dip->disk_bytenr = (u64)bio->bi_sector << 9;
7278 bio->bi_private = dip;
7279 dip->errors = 0;
7280 dip->orig_bio = bio;
7281 atomic_set(&dip->pending_bios, 0);
7282
7283 if (write)
7284 bio->bi_end_io = btrfs_endio_direct_write;
7285 else
7286 bio->bi_end_io = btrfs_endio_direct_read;
7287
7288 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
7289 if (!ret)
7290 return;
7291 free_ordered:
7292 /*
7293 * If this is a write, we need to clean up the reserved space and kill
7294 * the ordered extent.
7295 */
7296 if (write) {
7297 struct btrfs_ordered_extent *ordered;
7298 ordered = btrfs_lookup_ordered_extent(inode, file_offset);
7299 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
7300 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
7301 btrfs_free_reserved_extent(root, ordered->start,
7302 ordered->disk_len);
7303 btrfs_put_ordered_extent(ordered);
7304 btrfs_put_ordered_extent(ordered);
7305 }
7306 bio_endio(bio, ret);
7307 }
7308
7309 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb,
7310 const struct iovec *iov, loff_t offset,
7311 unsigned long nr_segs)
7312 {
7313 int seg;
7314 int i;
7315 size_t size;
7316 unsigned long addr;
7317 unsigned blocksize_mask = root->sectorsize - 1;
7318 ssize_t retval = -EINVAL;
7319 loff_t end = offset;
7320
7321 if (offset & blocksize_mask)
7322 goto out;
7323
7324 /* Check the memory alignment. Blocks cannot straddle pages */
7325 for (seg = 0; seg < nr_segs; seg++) {
7326 addr = (unsigned long)iov[seg].iov_base;
7327 size = iov[seg].iov_len;
7328 end += size;
7329 if ((addr & blocksize_mask) || (size & blocksize_mask))
7330 goto out;
7331
7332 /* If this is a write we don't need to check anymore */
7333 if (rw & WRITE)
7334 continue;
7335
7336 /*
7337 * Check to make sure we don't have duplicate iov_base's in this
7338 * iovec, if so return EINVAL, otherwise we'll get csum errors
7339 * when reading back.
7340 */
7341 for (i = seg + 1; i < nr_segs; i++) {
7342 if (iov[seg].iov_base == iov[i].iov_base)
7343 goto out;
7344 }
7345 }
7346 retval = 0;
7347 out:
7348 return retval;
7349 }
7350
7351 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
7352 const struct iovec *iov, loff_t offset,
7353 unsigned long nr_segs)
7354 {
7355 struct file *file = iocb->ki_filp;
7356 struct inode *inode = file->f_mapping->host;
7357 size_t count = 0;
7358 int flags = 0;
7359 bool wakeup = true;
7360 bool relock = false;
7361 ssize_t ret;
7362
7363 if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
7364 offset, nr_segs))
7365 return 0;
7366
7367 atomic_inc(&inode->i_dio_count);
7368 smp_mb__after_atomic_inc();
7369
7370 if (rw & WRITE) {
7371 count = iov_length(iov, nr_segs);
7372 /*
7373 * If the write DIO is beyond the EOF, we need update
7374 * the isize, but it is protected by i_mutex. So we can
7375 * not unlock the i_mutex at this case.
7376 */
7377 if (offset + count <= inode->i_size) {
7378 mutex_unlock(&inode->i_mutex);
7379 relock = true;
7380 }
7381 ret = btrfs_delalloc_reserve_space(inode, count);
7382 if (ret)
7383 goto out;
7384 } else if (unlikely(test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
7385 &BTRFS_I(inode)->runtime_flags))) {
7386 inode_dio_done(inode);
7387 flags = DIO_LOCKING | DIO_SKIP_HOLES;
7388 wakeup = false;
7389 }
7390
7391 ret = __blockdev_direct_IO(rw, iocb, inode,
7392 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
7393 iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
7394 btrfs_submit_direct, flags);
7395 if (rw & WRITE) {
7396 if (ret < 0 && ret != -EIOCBQUEUED)
7397 btrfs_delalloc_release_space(inode, count);
7398 else if (ret >= 0 && (size_t)ret < count)
7399 btrfs_delalloc_release_space(inode,
7400 count - (size_t)ret);
7401 else
7402 btrfs_delalloc_release_metadata(inode, 0);
7403 }
7404 out:
7405 if (wakeup)
7406 inode_dio_done(inode);
7407 if (relock)
7408 mutex_lock(&inode->i_mutex);
7409
7410 return ret;
7411 }
7412
7413 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
7414
7415 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
7416 __u64 start, __u64 len)
7417 {
7418 int ret;
7419
7420 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
7421 if (ret)
7422 return ret;
7423
7424 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
7425 }
7426
7427 int btrfs_readpage(struct file *file, struct page *page)
7428 {
7429 struct extent_io_tree *tree;
7430 tree = &BTRFS_I(page->mapping->host)->io_tree;
7431 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
7432 }
7433
7434 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
7435 {
7436 struct extent_io_tree *tree;
7437
7438
7439 if (current->flags & PF_MEMALLOC) {
7440 redirty_page_for_writepage(wbc, page);
7441 unlock_page(page);
7442 return 0;
7443 }
7444 tree = &BTRFS_I(page->mapping->host)->io_tree;
7445 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
7446 }
7447
7448 static int btrfs_writepages(struct address_space *mapping,
7449 struct writeback_control *wbc)
7450 {
7451 struct extent_io_tree *tree;
7452
7453 tree = &BTRFS_I(mapping->host)->io_tree;
7454 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
7455 }
7456
7457 static int
7458 btrfs_readpages(struct file *file, struct address_space *mapping,
7459 struct list_head *pages, unsigned nr_pages)
7460 {
7461 struct extent_io_tree *tree;
7462 tree = &BTRFS_I(mapping->host)->io_tree;
7463 return extent_readpages(tree, mapping, pages, nr_pages,
7464 btrfs_get_extent);
7465 }
7466 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
7467 {
7468 struct extent_io_tree *tree;
7469 struct extent_map_tree *map;
7470 int ret;
7471
7472 tree = &BTRFS_I(page->mapping->host)->io_tree;
7473 map = &BTRFS_I(page->mapping->host)->extent_tree;
7474 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
7475 if (ret == 1) {
7476 ClearPagePrivate(page);
7477 set_page_private(page, 0);
7478 page_cache_release(page);
7479 }
7480 return ret;
7481 }
7482
7483 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
7484 {
7485 if (PageWriteback(page) || PageDirty(page))
7486 return 0;
7487 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
7488 }
7489
7490 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
7491 {
7492 struct inode *inode = page->mapping->host;
7493 struct extent_io_tree *tree;
7494 struct btrfs_ordered_extent *ordered;
7495 struct extent_state *cached_state = NULL;
7496 u64 page_start = page_offset(page);
7497 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
7498
7499 /*
7500 * we have the page locked, so new writeback can't start,
7501 * and the dirty bit won't be cleared while we are here.
7502 *
7503 * Wait for IO on this page so that we can safely clear
7504 * the PagePrivate2 bit and do ordered accounting
7505 */
7506 wait_on_page_writeback(page);
7507
7508 tree = &BTRFS_I(inode)->io_tree;
7509 if (offset) {
7510 btrfs_releasepage(page, GFP_NOFS);
7511 return;
7512 }
7513 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
7514 ordered = btrfs_lookup_ordered_extent(inode, page_offset(page));
7515 if (ordered) {
7516 /*
7517 * IO on this page will never be started, so we need
7518 * to account for any ordered extents now
7519 */
7520 clear_extent_bit(tree, page_start, page_end,
7521 EXTENT_DIRTY | EXTENT_DELALLOC |
7522 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
7523 EXTENT_DEFRAG, 1, 0, &cached_state, GFP_NOFS);
7524 /*
7525 * whoever cleared the private bit is responsible
7526 * for the finish_ordered_io
7527 */
7528 if (TestClearPagePrivate2(page) &&
7529 btrfs_dec_test_ordered_pending(inode, &ordered, page_start,
7530 PAGE_CACHE_SIZE, 1)) {
7531 btrfs_finish_ordered_io(ordered);
7532 }
7533 btrfs_put_ordered_extent(ordered);
7534 cached_state = NULL;
7535 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
7536 }
7537 clear_extent_bit(tree, page_start, page_end,
7538 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
7539 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
7540 &cached_state, GFP_NOFS);
7541 __btrfs_releasepage(page, GFP_NOFS);
7542
7543 ClearPageChecked(page);
7544 if (PagePrivate(page)) {
7545 ClearPagePrivate(page);
7546 set_page_private(page, 0);
7547 page_cache_release(page);
7548 }
7549 }
7550
7551 /*
7552 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
7553 * called from a page fault handler when a page is first dirtied. Hence we must
7554 * be careful to check for EOF conditions here. We set the page up correctly
7555 * for a written page which means we get ENOSPC checking when writing into
7556 * holes and correct delalloc and unwritten extent mapping on filesystems that
7557 * support these features.
7558 *
7559 * We are not allowed to take the i_mutex here so we have to play games to
7560 * protect against truncate races as the page could now be beyond EOF. Because
7561 * vmtruncate() writes the inode size before removing pages, once we have the
7562 * page lock we can determine safely if the page is beyond EOF. If it is not
7563 * beyond EOF, then the page is guaranteed safe against truncation until we
7564 * unlock the page.
7565 */
7566 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
7567 {
7568 struct page *page = vmf->page;
7569 struct inode *inode = file_inode(vma->vm_file);
7570 struct btrfs_root *root = BTRFS_I(inode)->root;
7571 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7572 struct btrfs_ordered_extent *ordered;
7573 struct extent_state *cached_state = NULL;
7574 char *kaddr;
7575 unsigned long zero_start;
7576 loff_t size;
7577 int ret;
7578 int reserved = 0;
7579 u64 page_start;
7580 u64 page_end;
7581
7582 sb_start_pagefault(inode->i_sb);
7583 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
7584 if (!ret) {
7585 ret = file_update_time(vma->vm_file);
7586 reserved = 1;
7587 }
7588 if (ret) {
7589 if (ret == -ENOMEM)
7590 ret = VM_FAULT_OOM;
7591 else /* -ENOSPC, -EIO, etc */
7592 ret = VM_FAULT_SIGBUS;
7593 if (reserved)
7594 goto out;
7595 goto out_noreserve;
7596 }
7597
7598 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
7599 again:
7600 lock_page(page);
7601 size = i_size_read(inode);
7602 page_start = page_offset(page);
7603 page_end = page_start + PAGE_CACHE_SIZE - 1;
7604
7605 if ((page->mapping != inode->i_mapping) ||
7606 (page_start >= size)) {
7607 /* page got truncated out from underneath us */
7608 goto out_unlock;
7609 }
7610 wait_on_page_writeback(page);
7611
7612 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
7613 set_page_extent_mapped(page);
7614
7615 /*
7616 * we can't set the delalloc bits if there are pending ordered
7617 * extents. Drop our locks and wait for them to finish
7618 */
7619 ordered = btrfs_lookup_ordered_extent(inode, page_start);
7620 if (ordered) {
7621 unlock_extent_cached(io_tree, page_start, page_end,
7622 &cached_state, GFP_NOFS);
7623 unlock_page(page);
7624 btrfs_start_ordered_extent(inode, ordered, 1);
7625 btrfs_put_ordered_extent(ordered);
7626 goto again;
7627 }
7628
7629 /*
7630 * XXX - page_mkwrite gets called every time the page is dirtied, even
7631 * if it was already dirty, so for space accounting reasons we need to
7632 * clear any delalloc bits for the range we are fixing to save. There
7633 * is probably a better way to do this, but for now keep consistent with
7634 * prepare_pages in the normal write path.
7635 */
7636 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
7637 EXTENT_DIRTY | EXTENT_DELALLOC |
7638 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
7639 0, 0, &cached_state, GFP_NOFS);
7640
7641 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
7642 &cached_state);
7643 if (ret) {
7644 unlock_extent_cached(io_tree, page_start, page_end,
7645 &cached_state, GFP_NOFS);
7646 ret = VM_FAULT_SIGBUS;
7647 goto out_unlock;
7648 }
7649 ret = 0;
7650
7651 /* page is wholly or partially inside EOF */
7652 if (page_start + PAGE_CACHE_SIZE > size)
7653 zero_start = size & ~PAGE_CACHE_MASK;
7654 else
7655 zero_start = PAGE_CACHE_SIZE;
7656
7657 if (zero_start != PAGE_CACHE_SIZE) {
7658 kaddr = kmap(page);
7659 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
7660 flush_dcache_page(page);
7661 kunmap(page);
7662 }
7663 ClearPageChecked(page);
7664 set_page_dirty(page);
7665 SetPageUptodate(page);
7666
7667 BTRFS_I(inode)->last_trans = root->fs_info->generation;
7668 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
7669 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
7670
7671 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
7672
7673 out_unlock:
7674 if (!ret) {
7675 sb_end_pagefault(inode->i_sb);
7676 return VM_FAULT_LOCKED;
7677 }
7678 unlock_page(page);
7679 out:
7680 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
7681 out_noreserve:
7682 sb_end_pagefault(inode->i_sb);
7683 return ret;
7684 }
7685
7686 static int btrfs_truncate(struct inode *inode)
7687 {
7688 struct btrfs_root *root = BTRFS_I(inode)->root;
7689 struct btrfs_block_rsv *rsv;
7690 int ret;
7691 int err = 0;
7692 struct btrfs_trans_handle *trans;
7693 u64 mask = root->sectorsize - 1;
7694 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
7695
7696 ret = btrfs_truncate_page(inode, inode->i_size, 0, 0);
7697 if (ret)
7698 return ret;
7699
7700 btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
7701 btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
7702
7703 /*
7704 * Yes ladies and gentelment, this is indeed ugly. The fact is we have
7705 * 3 things going on here
7706 *
7707 * 1) We need to reserve space for our orphan item and the space to
7708 * delete our orphan item. Lord knows we don't want to have a dangling
7709 * orphan item because we didn't reserve space to remove it.
7710 *
7711 * 2) We need to reserve space to update our inode.
7712 *
7713 * 3) We need to have something to cache all the space that is going to
7714 * be free'd up by the truncate operation, but also have some slack
7715 * space reserved in case it uses space during the truncate (thank you
7716 * very much snapshotting).
7717 *
7718 * And we need these to all be seperate. The fact is we can use alot of
7719 * space doing the truncate, and we have no earthly idea how much space
7720 * we will use, so we need the truncate reservation to be seperate so it
7721 * doesn't end up using space reserved for updating the inode or
7722 * removing the orphan item. We also need to be able to stop the
7723 * transaction and start a new one, which means we need to be able to
7724 * update the inode several times, and we have no idea of knowing how
7725 * many times that will be, so we can't just reserve 1 item for the
7726 * entirety of the opration, so that has to be done seperately as well.
7727 * Then there is the orphan item, which does indeed need to be held on
7728 * to for the whole operation, and we need nobody to touch this reserved
7729 * space except the orphan code.
7730 *
7731 * So that leaves us with
7732 *
7733 * 1) root->orphan_block_rsv - for the orphan deletion.
7734 * 2) rsv - for the truncate reservation, which we will steal from the
7735 * transaction reservation.
7736 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
7737 * updating the inode.
7738 */
7739 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
7740 if (!rsv)
7741 return -ENOMEM;
7742 rsv->size = min_size;
7743 rsv->failfast = 1;
7744
7745 /*
7746 * 1 for the truncate slack space
7747 * 1 for updating the inode.
7748 */
7749 trans = btrfs_start_transaction(root, 2);
7750 if (IS_ERR(trans)) {
7751 err = PTR_ERR(trans);
7752 goto out;
7753 }
7754
7755 /* Migrate the slack space for the truncate to our reserve */
7756 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
7757 min_size);
7758 BUG_ON(ret);
7759
7760 /*
7761 * setattr is responsible for setting the ordered_data_close flag,
7762 * but that is only tested during the last file release. That
7763 * could happen well after the next commit, leaving a great big
7764 * window where new writes may get lost if someone chooses to write
7765 * to this file after truncating to zero
7766 *
7767 * The inode doesn't have any dirty data here, and so if we commit
7768 * this is a noop. If someone immediately starts writing to the inode
7769 * it is very likely we'll catch some of their writes in this
7770 * transaction, and the commit will find this file on the ordered
7771 * data list with good things to send down.
7772 *
7773 * This is a best effort solution, there is still a window where
7774 * using truncate to replace the contents of the file will
7775 * end up with a zero length file after a crash.
7776 */
7777 if (inode->i_size == 0 && test_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
7778 &BTRFS_I(inode)->runtime_flags))
7779 btrfs_add_ordered_operation(trans, root, inode);
7780
7781 /*
7782 * So if we truncate and then write and fsync we normally would just
7783 * write the extents that changed, which is a problem if we need to
7784 * first truncate that entire inode. So set this flag so we write out
7785 * all of the extents in the inode to the sync log so we're completely
7786 * safe.
7787 */
7788 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
7789 trans->block_rsv = rsv;
7790
7791 while (1) {
7792 ret = btrfs_truncate_inode_items(trans, root, inode,
7793 inode->i_size,
7794 BTRFS_EXTENT_DATA_KEY);
7795 if (ret != -ENOSPC) {
7796 err = ret;
7797 break;
7798 }
7799
7800 trans->block_rsv = &root->fs_info->trans_block_rsv;
7801 ret = btrfs_update_inode(trans, root, inode);
7802 if (ret) {
7803 err = ret;
7804 break;
7805 }
7806
7807 btrfs_end_transaction(trans, root);
7808 btrfs_btree_balance_dirty(root);
7809
7810 trans = btrfs_start_transaction(root, 2);
7811 if (IS_ERR(trans)) {
7812 ret = err = PTR_ERR(trans);
7813 trans = NULL;
7814 break;
7815 }
7816
7817 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
7818 rsv, min_size);
7819 BUG_ON(ret); /* shouldn't happen */
7820 trans->block_rsv = rsv;
7821 }
7822
7823 if (ret == 0 && inode->i_nlink > 0) {
7824 trans->block_rsv = root->orphan_block_rsv;
7825 ret = btrfs_orphan_del(trans, inode);
7826 if (ret)
7827 err = ret;
7828 }
7829
7830 if (trans) {
7831 trans->block_rsv = &root->fs_info->trans_block_rsv;
7832 ret = btrfs_update_inode(trans, root, inode);
7833 if (ret && !err)
7834 err = ret;
7835
7836 ret = btrfs_end_transaction(trans, root);
7837 btrfs_btree_balance_dirty(root);
7838 }
7839
7840 out:
7841 btrfs_free_block_rsv(root, rsv);
7842
7843 if (ret && !err)
7844 err = ret;
7845
7846 return err;
7847 }
7848
7849 /*
7850 * create a new subvolume directory/inode (helper for the ioctl).
7851 */
7852 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
7853 struct btrfs_root *new_root, u64 new_dirid)
7854 {
7855 struct inode *inode;
7856 int err;
7857 u64 index = 0;
7858
7859 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
7860 new_dirid, new_dirid,
7861 S_IFDIR | (~current_umask() & S_IRWXUGO),
7862 &index);
7863 if (IS_ERR(inode))
7864 return PTR_ERR(inode);
7865 inode->i_op = &btrfs_dir_inode_operations;
7866 inode->i_fop = &btrfs_dir_file_operations;
7867
7868 set_nlink(inode, 1);
7869 btrfs_i_size_write(inode, 0);
7870
7871 err = btrfs_update_inode(trans, new_root, inode);
7872
7873 iput(inode);
7874 return err;
7875 }
7876
7877 struct inode *btrfs_alloc_inode(struct super_block *sb)
7878 {
7879 struct btrfs_inode *ei;
7880 struct inode *inode;
7881
7882 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
7883 if (!ei)
7884 return NULL;
7885
7886 ei->root = NULL;
7887 ei->generation = 0;
7888 ei->last_trans = 0;
7889 ei->last_sub_trans = 0;
7890 ei->logged_trans = 0;
7891 ei->delalloc_bytes = 0;
7892 ei->disk_i_size = 0;
7893 ei->flags = 0;
7894 ei->csum_bytes = 0;
7895 ei->index_cnt = (u64)-1;
7896 ei->last_unlink_trans = 0;
7897 ei->last_log_commit = 0;
7898
7899 spin_lock_init(&ei->lock);
7900 ei->outstanding_extents = 0;
7901 ei->reserved_extents = 0;
7902
7903 ei->runtime_flags = 0;
7904 ei->force_compress = BTRFS_COMPRESS_NONE;
7905
7906 ei->delayed_node = NULL;
7907
7908 inode = &ei->vfs_inode;
7909 extent_map_tree_init(&ei->extent_tree);
7910 extent_io_tree_init(&ei->io_tree, &inode->i_data);
7911 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
7912 ei->io_tree.track_uptodate = 1;
7913 ei->io_failure_tree.track_uptodate = 1;
7914 atomic_set(&ei->sync_writers, 0);
7915 mutex_init(&ei->log_mutex);
7916 mutex_init(&ei->delalloc_mutex);
7917 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
7918 INIT_LIST_HEAD(&ei->delalloc_inodes);
7919 INIT_LIST_HEAD(&ei->ordered_operations);
7920 RB_CLEAR_NODE(&ei->rb_node);
7921
7922 return inode;
7923 }
7924
7925 static void btrfs_i_callback(struct rcu_head *head)
7926 {
7927 struct inode *inode = container_of(head, struct inode, i_rcu);
7928 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
7929 }
7930
7931 void btrfs_destroy_inode(struct inode *inode)
7932 {
7933 struct btrfs_ordered_extent *ordered;
7934 struct btrfs_root *root = BTRFS_I(inode)->root;
7935
7936 WARN_ON(!hlist_empty(&inode->i_dentry));
7937 WARN_ON(inode->i_data.nrpages);
7938 WARN_ON(BTRFS_I(inode)->outstanding_extents);
7939 WARN_ON(BTRFS_I(inode)->reserved_extents);
7940 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
7941 WARN_ON(BTRFS_I(inode)->csum_bytes);
7942
7943 /*
7944 * This can happen where we create an inode, but somebody else also
7945 * created the same inode and we need to destroy the one we already
7946 * created.
7947 */
7948 if (!root)
7949 goto free;
7950
7951 /*
7952 * Make sure we're properly removed from the ordered operation
7953 * lists.
7954 */
7955 smp_mb();
7956 if (!list_empty(&BTRFS_I(inode)->ordered_operations)) {
7957 spin_lock(&root->fs_info->ordered_extent_lock);
7958 list_del_init(&BTRFS_I(inode)->ordered_operations);
7959 spin_unlock(&root->fs_info->ordered_extent_lock);
7960 }
7961
7962 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
7963 &BTRFS_I(inode)->runtime_flags)) {
7964 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
7965 (unsigned long long)btrfs_ino(inode));
7966 atomic_dec(&root->orphan_inodes);
7967 }
7968
7969 while (1) {
7970 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
7971 if (!ordered)
7972 break;
7973 else {
7974 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
7975 (unsigned long long)ordered->file_offset,
7976 (unsigned long long)ordered->len);
7977 btrfs_remove_ordered_extent(inode, ordered);
7978 btrfs_put_ordered_extent(ordered);
7979 btrfs_put_ordered_extent(ordered);
7980 }
7981 }
7982 inode_tree_del(inode);
7983 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
7984 free:
7985 btrfs_remove_delayed_node(inode);
7986 call_rcu(&inode->i_rcu, btrfs_i_callback);
7987 }
7988
7989 int btrfs_drop_inode(struct inode *inode)
7990 {
7991 struct btrfs_root *root = BTRFS_I(inode)->root;
7992
7993 /* the snap/subvol tree is on deleting */
7994 if (btrfs_root_refs(&root->root_item) == 0 &&
7995 root != root->fs_info->tree_root)
7996 return 1;
7997 else
7998 return generic_drop_inode(inode);
7999 }
8000
8001 static void init_once(void *foo)
8002 {
8003 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
8004
8005 inode_init_once(&ei->vfs_inode);
8006 }
8007
8008 void btrfs_destroy_cachep(void)
8009 {
8010 /*
8011 * Make sure all delayed rcu free inodes are flushed before we
8012 * destroy cache.
8013 */
8014 rcu_barrier();
8015 if (btrfs_inode_cachep)
8016 kmem_cache_destroy(btrfs_inode_cachep);
8017 if (btrfs_trans_handle_cachep)
8018 kmem_cache_destroy(btrfs_trans_handle_cachep);
8019 if (btrfs_transaction_cachep)
8020 kmem_cache_destroy(btrfs_transaction_cachep);
8021 if (btrfs_path_cachep)
8022 kmem_cache_destroy(btrfs_path_cachep);
8023 if (btrfs_free_space_cachep)
8024 kmem_cache_destroy(btrfs_free_space_cachep);
8025 if (btrfs_delalloc_work_cachep)
8026 kmem_cache_destroy(btrfs_delalloc_work_cachep);
8027 }
8028
8029 int btrfs_init_cachep(void)
8030 {
8031 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
8032 sizeof(struct btrfs_inode), 0,
8033 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
8034 if (!btrfs_inode_cachep)
8035 goto fail;
8036
8037 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
8038 sizeof(struct btrfs_trans_handle), 0,
8039 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8040 if (!btrfs_trans_handle_cachep)
8041 goto fail;
8042
8043 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
8044 sizeof(struct btrfs_transaction), 0,
8045 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8046 if (!btrfs_transaction_cachep)
8047 goto fail;
8048
8049 btrfs_path_cachep = kmem_cache_create("btrfs_path",
8050 sizeof(struct btrfs_path), 0,
8051 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8052 if (!btrfs_path_cachep)
8053 goto fail;
8054
8055 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
8056 sizeof(struct btrfs_free_space), 0,
8057 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8058 if (!btrfs_free_space_cachep)
8059 goto fail;
8060
8061 btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work",
8062 sizeof(struct btrfs_delalloc_work), 0,
8063 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
8064 NULL);
8065 if (!btrfs_delalloc_work_cachep)
8066 goto fail;
8067
8068 return 0;
8069 fail:
8070 btrfs_destroy_cachep();
8071 return -ENOMEM;
8072 }
8073
8074 static int btrfs_getattr(struct vfsmount *mnt,
8075 struct dentry *dentry, struct kstat *stat)
8076 {
8077 u64 delalloc_bytes;
8078 struct inode *inode = dentry->d_inode;
8079 u32 blocksize = inode->i_sb->s_blocksize;
8080
8081 generic_fillattr(inode, stat);
8082 stat->dev = BTRFS_I(inode)->root->anon_dev;
8083 stat->blksize = PAGE_CACHE_SIZE;
8084
8085 spin_lock(&BTRFS_I(inode)->lock);
8086 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
8087 spin_unlock(&BTRFS_I(inode)->lock);
8088 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
8089 ALIGN(delalloc_bytes, blocksize)) >> 9;
8090 return 0;
8091 }
8092
8093 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
8094 struct inode *new_dir, struct dentry *new_dentry)
8095 {
8096 struct btrfs_trans_handle *trans;
8097 struct btrfs_root *root = BTRFS_I(old_dir)->root;
8098 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
8099 struct inode *new_inode = new_dentry->d_inode;
8100 struct inode *old_inode = old_dentry->d_inode;
8101 struct timespec ctime = CURRENT_TIME;
8102 u64 index = 0;
8103 u64 root_objectid;
8104 int ret;
8105 u64 old_ino = btrfs_ino(old_inode);
8106
8107 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
8108 return -EPERM;
8109
8110 /* we only allow rename subvolume link between subvolumes */
8111 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
8112 return -EXDEV;
8113
8114 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
8115 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
8116 return -ENOTEMPTY;
8117
8118 if (S_ISDIR(old_inode->i_mode) && new_inode &&
8119 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
8120 return -ENOTEMPTY;
8121
8122
8123 /* check for collisions, even if the name isn't there */
8124 ret = btrfs_check_dir_item_collision(root, new_dir->i_ino,
8125 new_dentry->d_name.name,
8126 new_dentry->d_name.len);
8127
8128 if (ret) {
8129 if (ret == -EEXIST) {
8130 /* we shouldn't get
8131 * eexist without a new_inode */
8132 if (!new_inode) {
8133 WARN_ON(1);
8134 return ret;
8135 }
8136 } else {
8137 /* maybe -EOVERFLOW */
8138 return ret;
8139 }
8140 }
8141 ret = 0;
8142
8143 /*
8144 * we're using rename to replace one file with another.
8145 * and the replacement file is large. Start IO on it now so
8146 * we don't add too much work to the end of the transaction
8147 */
8148 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size &&
8149 old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
8150 filemap_flush(old_inode->i_mapping);
8151
8152 /* close the racy window with snapshot create/destroy ioctl */
8153 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
8154 down_read(&root->fs_info->subvol_sem);
8155 /*
8156 * We want to reserve the absolute worst case amount of items. So if
8157 * both inodes are subvols and we need to unlink them then that would
8158 * require 4 item modifications, but if they are both normal inodes it
8159 * would require 5 item modifications, so we'll assume their normal
8160 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
8161 * should cover the worst case number of items we'll modify.
8162 */
8163 trans = btrfs_start_transaction(root, 11);
8164 if (IS_ERR(trans)) {
8165 ret = PTR_ERR(trans);
8166 goto out_notrans;
8167 }
8168
8169 if (dest != root)
8170 btrfs_record_root_in_trans(trans, dest);
8171
8172 ret = btrfs_set_inode_index(new_dir, &index);
8173 if (ret)
8174 goto out_fail;
8175
8176 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
8177 /* force full log commit if subvolume involved. */
8178 root->fs_info->last_trans_log_full_commit = trans->transid;
8179 } else {
8180 ret = btrfs_insert_inode_ref(trans, dest,
8181 new_dentry->d_name.name,
8182 new_dentry->d_name.len,
8183 old_ino,
8184 btrfs_ino(new_dir), index);
8185 if (ret)
8186 goto out_fail;
8187 /*
8188 * this is an ugly little race, but the rename is required
8189 * to make sure that if we crash, the inode is either at the
8190 * old name or the new one. pinning the log transaction lets
8191 * us make sure we don't allow a log commit to come in after
8192 * we unlink the name but before we add the new name back in.
8193 */
8194 btrfs_pin_log_trans(root);
8195 }
8196 /*
8197 * make sure the inode gets flushed if it is replacing
8198 * something.
8199 */
8200 if (new_inode && new_inode->i_size && S_ISREG(old_inode->i_mode))
8201 btrfs_add_ordered_operation(trans, root, old_inode);
8202
8203 inode_inc_iversion(old_dir);
8204 inode_inc_iversion(new_dir);
8205 inode_inc_iversion(old_inode);
8206 old_dir->i_ctime = old_dir->i_mtime = ctime;
8207 new_dir->i_ctime = new_dir->i_mtime = ctime;
8208 old_inode->i_ctime = ctime;
8209
8210 if (old_dentry->d_parent != new_dentry->d_parent)
8211 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
8212
8213 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
8214 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
8215 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
8216 old_dentry->d_name.name,
8217 old_dentry->d_name.len);
8218 } else {
8219 ret = __btrfs_unlink_inode(trans, root, old_dir,
8220 old_dentry->d_inode,
8221 old_dentry->d_name.name,
8222 old_dentry->d_name.len);
8223 if (!ret)
8224 ret = btrfs_update_inode(trans, root, old_inode);
8225 }
8226 if (ret) {
8227 btrfs_abort_transaction(trans, root, ret);
8228 goto out_fail;
8229 }
8230
8231 if (new_inode) {
8232 inode_inc_iversion(new_inode);
8233 new_inode->i_ctime = CURRENT_TIME;
8234 if (unlikely(btrfs_ino(new_inode) ==
8235 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
8236 root_objectid = BTRFS_I(new_inode)->location.objectid;
8237 ret = btrfs_unlink_subvol(trans, dest, new_dir,
8238 root_objectid,
8239 new_dentry->d_name.name,
8240 new_dentry->d_name.len);
8241 BUG_ON(new_inode->i_nlink == 0);
8242 } else {
8243 ret = btrfs_unlink_inode(trans, dest, new_dir,
8244 new_dentry->d_inode,
8245 new_dentry->d_name.name,
8246 new_dentry->d_name.len);
8247 }
8248 if (!ret && new_inode->i_nlink == 0) {
8249 ret = btrfs_orphan_add(trans, new_dentry->d_inode);
8250 BUG_ON(ret);
8251 }
8252 if (ret) {
8253 btrfs_abort_transaction(trans, root, ret);
8254 goto out_fail;
8255 }
8256 }
8257
8258 ret = btrfs_add_link(trans, new_dir, old_inode,
8259 new_dentry->d_name.name,
8260 new_dentry->d_name.len, 0, index);
8261 if (ret) {
8262 btrfs_abort_transaction(trans, root, ret);
8263 goto out_fail;
8264 }
8265
8266 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
8267 struct dentry *parent = new_dentry->d_parent;
8268 btrfs_log_new_name(trans, old_inode, old_dir, parent);
8269 btrfs_end_log_trans(root);
8270 }
8271 out_fail:
8272 btrfs_end_transaction(trans, root);
8273 out_notrans:
8274 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
8275 up_read(&root->fs_info->subvol_sem);
8276
8277 return ret;
8278 }
8279
8280 static void btrfs_run_delalloc_work(struct btrfs_work *work)
8281 {
8282 struct btrfs_delalloc_work *delalloc_work;
8283
8284 delalloc_work = container_of(work, struct btrfs_delalloc_work,
8285 work);
8286 if (delalloc_work->wait)
8287 btrfs_wait_ordered_range(delalloc_work->inode, 0, (u64)-1);
8288 else
8289 filemap_flush(delalloc_work->inode->i_mapping);
8290
8291 if (delalloc_work->delay_iput)
8292 btrfs_add_delayed_iput(delalloc_work->inode);
8293 else
8294 iput(delalloc_work->inode);
8295 complete(&delalloc_work->completion);
8296 }
8297
8298 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
8299 int wait, int delay_iput)
8300 {
8301 struct btrfs_delalloc_work *work;
8302
8303 work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS);
8304 if (!work)
8305 return NULL;
8306
8307 init_completion(&work->completion);
8308 INIT_LIST_HEAD(&work->list);
8309 work->inode = inode;
8310 work->wait = wait;
8311 work->delay_iput = delay_iput;
8312 work->work.func = btrfs_run_delalloc_work;
8313
8314 return work;
8315 }
8316
8317 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
8318 {
8319 wait_for_completion(&work->completion);
8320 kmem_cache_free(btrfs_delalloc_work_cachep, work);
8321 }
8322
8323 /*
8324 * some fairly slow code that needs optimization. This walks the list
8325 * of all the inodes with pending delalloc and forces them to disk.
8326 */
8327 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
8328 {
8329 struct btrfs_inode *binode;
8330 struct inode *inode;
8331 struct btrfs_delalloc_work *work, *next;
8332 struct list_head works;
8333 struct list_head splice;
8334 int ret = 0;
8335
8336 if (root->fs_info->sb->s_flags & MS_RDONLY)
8337 return -EROFS;
8338
8339 INIT_LIST_HEAD(&works);
8340 INIT_LIST_HEAD(&splice);
8341
8342 spin_lock(&root->fs_info->delalloc_lock);
8343 list_splice_init(&root->fs_info->delalloc_inodes, &splice);
8344 while (!list_empty(&splice)) {
8345 binode = list_entry(splice.next, struct btrfs_inode,
8346 delalloc_inodes);
8347
8348 list_del_init(&binode->delalloc_inodes);
8349
8350 inode = igrab(&binode->vfs_inode);
8351 if (!inode) {
8352 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
8353 &binode->runtime_flags);
8354 continue;
8355 }
8356
8357 list_add_tail(&binode->delalloc_inodes,
8358 &root->fs_info->delalloc_inodes);
8359 spin_unlock(&root->fs_info->delalloc_lock);
8360
8361 work = btrfs_alloc_delalloc_work(inode, 0, delay_iput);
8362 if (unlikely(!work)) {
8363 ret = -ENOMEM;
8364 goto out;
8365 }
8366 list_add_tail(&work->list, &works);
8367 btrfs_queue_worker(&root->fs_info->flush_workers,
8368 &work->work);
8369
8370 cond_resched();
8371 spin_lock(&root->fs_info->delalloc_lock);
8372 }
8373 spin_unlock(&root->fs_info->delalloc_lock);
8374
8375 list_for_each_entry_safe(work, next, &works, list) {
8376 list_del_init(&work->list);
8377 btrfs_wait_and_free_delalloc_work(work);
8378 }
8379
8380 /* the filemap_flush will queue IO into the worker threads, but
8381 * we have to make sure the IO is actually started and that
8382 * ordered extents get created before we return
8383 */
8384 atomic_inc(&root->fs_info->async_submit_draining);
8385 while (atomic_read(&root->fs_info->nr_async_submits) ||
8386 atomic_read(&root->fs_info->async_delalloc_pages)) {
8387 wait_event(root->fs_info->async_submit_wait,
8388 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
8389 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
8390 }
8391 atomic_dec(&root->fs_info->async_submit_draining);
8392 return 0;
8393 out:
8394 list_for_each_entry_safe(work, next, &works, list) {
8395 list_del_init(&work->list);
8396 btrfs_wait_and_free_delalloc_work(work);
8397 }
8398
8399 if (!list_empty_careful(&splice)) {
8400 spin_lock(&root->fs_info->delalloc_lock);
8401 list_splice_tail(&splice, &root->fs_info->delalloc_inodes);
8402 spin_unlock(&root->fs_info->delalloc_lock);
8403 }
8404 return ret;
8405 }
8406
8407 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
8408 const char *symname)
8409 {
8410 struct btrfs_trans_handle *trans;
8411 struct btrfs_root *root = BTRFS_I(dir)->root;
8412 struct btrfs_path *path;
8413 struct btrfs_key key;
8414 struct inode *inode = NULL;
8415 int err;
8416 int drop_inode = 0;
8417 u64 objectid;
8418 u64 index = 0 ;
8419 int name_len;
8420 int datasize;
8421 unsigned long ptr;
8422 struct btrfs_file_extent_item *ei;
8423 struct extent_buffer *leaf;
8424
8425 name_len = strlen(symname) + 1;
8426 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
8427 return -ENAMETOOLONG;
8428
8429 /*
8430 * 2 items for inode item and ref
8431 * 2 items for dir items
8432 * 1 item for xattr if selinux is on
8433 */
8434 trans = btrfs_start_transaction(root, 5);
8435 if (IS_ERR(trans))
8436 return PTR_ERR(trans);
8437
8438 err = btrfs_find_free_ino(root, &objectid);
8439 if (err)
8440 goto out_unlock;
8441
8442 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
8443 dentry->d_name.len, btrfs_ino(dir), objectid,
8444 S_IFLNK|S_IRWXUGO, &index);
8445 if (IS_ERR(inode)) {
8446 err = PTR_ERR(inode);
8447 goto out_unlock;
8448 }
8449
8450 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
8451 if (err) {
8452 drop_inode = 1;
8453 goto out_unlock;
8454 }
8455
8456 /*
8457 * If the active LSM wants to access the inode during
8458 * d_instantiate it needs these. Smack checks to see
8459 * if the filesystem supports xattrs by looking at the
8460 * ops vector.
8461 */
8462 inode->i_fop = &btrfs_file_operations;
8463 inode->i_op = &btrfs_file_inode_operations;
8464
8465 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
8466 if (err)
8467 drop_inode = 1;
8468 else {
8469 inode->i_mapping->a_ops = &btrfs_aops;
8470 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
8471 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
8472 }
8473 if (drop_inode)
8474 goto out_unlock;
8475
8476 path = btrfs_alloc_path();
8477 if (!path) {
8478 err = -ENOMEM;
8479 drop_inode = 1;
8480 goto out_unlock;
8481 }
8482 key.objectid = btrfs_ino(inode);
8483 key.offset = 0;
8484 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
8485 datasize = btrfs_file_extent_calc_inline_size(name_len);
8486 err = btrfs_insert_empty_item(trans, root, path, &key,
8487 datasize);
8488 if (err) {
8489 drop_inode = 1;
8490 btrfs_free_path(path);
8491 goto out_unlock;
8492 }
8493 leaf = path->nodes[0];
8494 ei = btrfs_item_ptr(leaf, path->slots[0],
8495 struct btrfs_file_extent_item);
8496 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
8497 btrfs_set_file_extent_type(leaf, ei,
8498 BTRFS_FILE_EXTENT_INLINE);
8499 btrfs_set_file_extent_encryption(leaf, ei, 0);
8500 btrfs_set_file_extent_compression(leaf, ei, 0);
8501 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
8502 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
8503
8504 ptr = btrfs_file_extent_inline_start(ei);
8505 write_extent_buffer(leaf, symname, ptr, name_len);
8506 btrfs_mark_buffer_dirty(leaf);
8507 btrfs_free_path(path);
8508
8509 inode->i_op = &btrfs_symlink_inode_operations;
8510 inode->i_mapping->a_ops = &btrfs_symlink_aops;
8511 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
8512 inode_set_bytes(inode, name_len);
8513 btrfs_i_size_write(inode, name_len - 1);
8514 err = btrfs_update_inode(trans, root, inode);
8515 if (err)
8516 drop_inode = 1;
8517
8518 out_unlock:
8519 if (!err)
8520 d_instantiate(dentry, inode);
8521 btrfs_end_transaction(trans, root);
8522 if (drop_inode) {
8523 inode_dec_link_count(inode);
8524 iput(inode);
8525 }
8526 btrfs_btree_balance_dirty(root);
8527 return err;
8528 }
8529
8530 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
8531 u64 start, u64 num_bytes, u64 min_size,
8532 loff_t actual_len, u64 *alloc_hint,
8533 struct btrfs_trans_handle *trans)
8534 {
8535 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
8536 struct extent_map *em;
8537 struct btrfs_root *root = BTRFS_I(inode)->root;
8538 struct btrfs_key ins;
8539 u64 cur_offset = start;
8540 u64 i_size;
8541 u64 cur_bytes;
8542 int ret = 0;
8543 bool own_trans = true;
8544
8545 if (trans)
8546 own_trans = false;
8547 while (num_bytes > 0) {
8548 if (own_trans) {
8549 trans = btrfs_start_transaction(root, 3);
8550 if (IS_ERR(trans)) {
8551 ret = PTR_ERR(trans);
8552 break;
8553 }
8554 }
8555
8556 cur_bytes = min(num_bytes, 256ULL * 1024 * 1024);
8557 cur_bytes = max(cur_bytes, min_size);
8558 ret = btrfs_reserve_extent(trans, root, cur_bytes,
8559 min_size, 0, *alloc_hint, &ins, 1);
8560 if (ret) {
8561 if (own_trans)
8562 btrfs_end_transaction(trans, root);
8563 break;
8564 }
8565
8566 ret = insert_reserved_file_extent(trans, inode,
8567 cur_offset, ins.objectid,
8568 ins.offset, ins.offset,
8569 ins.offset, 0, 0, 0,
8570 BTRFS_FILE_EXTENT_PREALLOC);
8571 if (ret) {
8572 btrfs_abort_transaction(trans, root, ret);
8573 if (own_trans)
8574 btrfs_end_transaction(trans, root);
8575 break;
8576 }
8577 btrfs_drop_extent_cache(inode, cur_offset,
8578 cur_offset + ins.offset -1, 0);
8579
8580 em = alloc_extent_map();
8581 if (!em) {
8582 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
8583 &BTRFS_I(inode)->runtime_flags);
8584 goto next;
8585 }
8586
8587 em->start = cur_offset;
8588 em->orig_start = cur_offset;
8589 em->len = ins.offset;
8590 em->block_start = ins.objectid;
8591 em->block_len = ins.offset;
8592 em->orig_block_len = ins.offset;
8593 em->ram_bytes = ins.offset;
8594 em->bdev = root->fs_info->fs_devices->latest_bdev;
8595 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
8596 em->generation = trans->transid;
8597
8598 while (1) {
8599 write_lock(&em_tree->lock);
8600 ret = add_extent_mapping(em_tree, em, 1);
8601 write_unlock(&em_tree->lock);
8602 if (ret != -EEXIST)
8603 break;
8604 btrfs_drop_extent_cache(inode, cur_offset,
8605 cur_offset + ins.offset - 1,
8606 0);
8607 }
8608 free_extent_map(em);
8609 next:
8610 num_bytes -= ins.offset;
8611 cur_offset += ins.offset;
8612 *alloc_hint = ins.objectid + ins.offset;
8613
8614 inode_inc_iversion(inode);
8615 inode->i_ctime = CURRENT_TIME;
8616 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
8617 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
8618 (actual_len > inode->i_size) &&
8619 (cur_offset > inode->i_size)) {
8620 if (cur_offset > actual_len)
8621 i_size = actual_len;
8622 else
8623 i_size = cur_offset;
8624 i_size_write(inode, i_size);
8625 btrfs_ordered_update_i_size(inode, i_size, NULL);
8626 }
8627
8628 ret = btrfs_update_inode(trans, root, inode);
8629
8630 if (ret) {
8631 btrfs_abort_transaction(trans, root, ret);
8632 if (own_trans)
8633 btrfs_end_transaction(trans, root);
8634 break;
8635 }
8636
8637 if (own_trans)
8638 btrfs_end_transaction(trans, root);
8639 }
8640 return ret;
8641 }
8642
8643 int btrfs_prealloc_file_range(struct inode *inode, int mode,
8644 u64 start, u64 num_bytes, u64 min_size,
8645 loff_t actual_len, u64 *alloc_hint)
8646 {
8647 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
8648 min_size, actual_len, alloc_hint,
8649 NULL);
8650 }
8651
8652 int btrfs_prealloc_file_range_trans(struct inode *inode,
8653 struct btrfs_trans_handle *trans, int mode,
8654 u64 start, u64 num_bytes, u64 min_size,
8655 loff_t actual_len, u64 *alloc_hint)
8656 {
8657 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
8658 min_size, actual_len, alloc_hint, trans);
8659 }
8660
8661 static int btrfs_set_page_dirty(struct page *page)
8662 {
8663 return __set_page_dirty_nobuffers(page);
8664 }
8665
8666 static int btrfs_permission(struct inode *inode, int mask)
8667 {
8668 struct btrfs_root *root = BTRFS_I(inode)->root;
8669 umode_t mode = inode->i_mode;
8670
8671 if (mask & MAY_WRITE &&
8672 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
8673 if (btrfs_root_readonly(root))
8674 return -EROFS;
8675 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
8676 return -EACCES;
8677 }
8678 return generic_permission(inode, mask);
8679 }
8680
8681 static const struct inode_operations btrfs_dir_inode_operations = {
8682 .getattr = btrfs_getattr,
8683 .lookup = btrfs_lookup,
8684 .create = btrfs_create,
8685 .unlink = btrfs_unlink,
8686 .link = btrfs_link,
8687 .mkdir = btrfs_mkdir,
8688 .rmdir = btrfs_rmdir,
8689 .rename = btrfs_rename,
8690 .symlink = btrfs_symlink,
8691 .setattr = btrfs_setattr,
8692 .mknod = btrfs_mknod,
8693 .setxattr = btrfs_setxattr,
8694 .getxattr = btrfs_getxattr,
8695 .listxattr = btrfs_listxattr,
8696 .removexattr = btrfs_removexattr,
8697 .permission = btrfs_permission,
8698 .get_acl = btrfs_get_acl,
8699 };
8700 static const struct inode_operations btrfs_dir_ro_inode_operations = {
8701 .lookup = btrfs_lookup,
8702 .permission = btrfs_permission,
8703 .get_acl = btrfs_get_acl,
8704 };
8705
8706 static const struct file_operations btrfs_dir_file_operations = {
8707 .llseek = generic_file_llseek,
8708 .read = generic_read_dir,
8709 .readdir = btrfs_real_readdir,
8710 .unlocked_ioctl = btrfs_ioctl,
8711 #ifdef CONFIG_COMPAT
8712 .compat_ioctl = btrfs_ioctl,
8713 #endif
8714 .release = btrfs_release_file,
8715 .fsync = btrfs_sync_file,
8716 };
8717
8718 static struct extent_io_ops btrfs_extent_io_ops = {
8719 .fill_delalloc = run_delalloc_range,
8720 .submit_bio_hook = btrfs_submit_bio_hook,
8721 .merge_bio_hook = btrfs_merge_bio_hook,
8722 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
8723 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
8724 .writepage_start_hook = btrfs_writepage_start_hook,
8725 .set_bit_hook = btrfs_set_bit_hook,
8726 .clear_bit_hook = btrfs_clear_bit_hook,
8727 .merge_extent_hook = btrfs_merge_extent_hook,
8728 .split_extent_hook = btrfs_split_extent_hook,
8729 };
8730
8731 /*
8732 * btrfs doesn't support the bmap operation because swapfiles
8733 * use bmap to make a mapping of extents in the file. They assume
8734 * these extents won't change over the life of the file and they
8735 * use the bmap result to do IO directly to the drive.
8736 *
8737 * the btrfs bmap call would return logical addresses that aren't
8738 * suitable for IO and they also will change frequently as COW
8739 * operations happen. So, swapfile + btrfs == corruption.
8740 *
8741 * For now we're avoiding this by dropping bmap.
8742 */
8743 static const struct address_space_operations btrfs_aops = {
8744 .readpage = btrfs_readpage,
8745 .writepage = btrfs_writepage,
8746 .writepages = btrfs_writepages,
8747 .readpages = btrfs_readpages,
8748 .direct_IO = btrfs_direct_IO,
8749 .invalidatepage = btrfs_invalidatepage,
8750 .releasepage = btrfs_releasepage,
8751 .set_page_dirty = btrfs_set_page_dirty,
8752 .error_remove_page = generic_error_remove_page,
8753 };
8754
8755 static const struct address_space_operations btrfs_symlink_aops = {
8756 .readpage = btrfs_readpage,
8757 .writepage = btrfs_writepage,
8758 .invalidatepage = btrfs_invalidatepage,
8759 .releasepage = btrfs_releasepage,
8760 };
8761
8762 static const struct inode_operations btrfs_file_inode_operations = {
8763 .getattr = btrfs_getattr,
8764 .setattr = btrfs_setattr,
8765 .setxattr = btrfs_setxattr,
8766 .getxattr = btrfs_getxattr,
8767 .listxattr = btrfs_listxattr,
8768 .removexattr = btrfs_removexattr,
8769 .permission = btrfs_permission,
8770 .fiemap = btrfs_fiemap,
8771 .get_acl = btrfs_get_acl,
8772 .update_time = btrfs_update_time,
8773 };
8774 static const struct inode_operations btrfs_special_inode_operations = {
8775 .getattr = btrfs_getattr,
8776 .setattr = btrfs_setattr,
8777 .permission = btrfs_permission,
8778 .setxattr = btrfs_setxattr,
8779 .getxattr = btrfs_getxattr,
8780 .listxattr = btrfs_listxattr,
8781 .removexattr = btrfs_removexattr,
8782 .get_acl = btrfs_get_acl,
8783 .update_time = btrfs_update_time,
8784 };
8785 static const struct inode_operations btrfs_symlink_inode_operations = {
8786 .readlink = generic_readlink,
8787 .follow_link = page_follow_link_light,
8788 .put_link = page_put_link,
8789 .getattr = btrfs_getattr,
8790 .setattr = btrfs_setattr,
8791 .permission = btrfs_permission,
8792 .setxattr = btrfs_setxattr,
8793 .getxattr = btrfs_getxattr,
8794 .listxattr = btrfs_listxattr,
8795 .removexattr = btrfs_removexattr,
8796 .get_acl = btrfs_get_acl,
8797 .update_time = btrfs_update_time,
8798 };
8799
8800 const struct dentry_operations btrfs_dentry_operations = {
8801 .d_delete = btrfs_dentry_delete,
8802 .d_release = btrfs_dentry_release,
8803 };
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