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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_init_inode_security(struct btrfs_trans_handle *trans,
107 struct inode *inode, struct inode *dir,
108 const struct qstr *qstr)
109 {
110 int err;
111
112 err = btrfs_init_acl(trans, inode, dir);
113 if (!err)
114 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
115 return err;
116 }
117
118 /*
119 * this does all the hard work for inserting an inline extent into
120 * the btree. The caller should have done a btrfs_drop_extents so that
121 * no overlapping inline items exist in the btree
122 */
123 static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
124 struct btrfs_root *root, struct inode *inode,
125 u64 start, size_t size, size_t compressed_size,
126 int compress_type,
127 struct page **compressed_pages)
128 {
129 struct btrfs_key key;
130 struct btrfs_path *path;
131 struct extent_buffer *leaf;
132 struct page *page = NULL;
133 char *kaddr;
134 unsigned long ptr;
135 struct btrfs_file_extent_item *ei;
136 int err = 0;
137 int ret;
138 size_t cur_size = size;
139 size_t datasize;
140 unsigned long offset;
141
142 if (compressed_size && compressed_pages)
143 cur_size = compressed_size;
144
145 path = btrfs_alloc_path();
146 if (!path)
147 return -ENOMEM;
148
149 path->leave_spinning = 1;
150
151 key.objectid = btrfs_ino(inode);
152 key.offset = start;
153 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
154 datasize = btrfs_file_extent_calc_inline_size(cur_size);
155
156 inode_add_bytes(inode, size);
157 ret = btrfs_insert_empty_item(trans, root, path, &key,
158 datasize);
159 if (ret) {
160 err = ret;
161 goto fail;
162 }
163 leaf = path->nodes[0];
164 ei = btrfs_item_ptr(leaf, path->slots[0],
165 struct btrfs_file_extent_item);
166 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
167 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
168 btrfs_set_file_extent_encryption(leaf, ei, 0);
169 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
170 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
171 ptr = btrfs_file_extent_inline_start(ei);
172
173 if (compress_type != BTRFS_COMPRESS_NONE) {
174 struct page *cpage;
175 int i = 0;
176 while (compressed_size > 0) {
177 cpage = compressed_pages[i];
178 cur_size = min_t(unsigned long, compressed_size,
179 PAGE_CACHE_SIZE);
180
181 kaddr = kmap_atomic(cpage);
182 write_extent_buffer(leaf, kaddr, ptr, cur_size);
183 kunmap_atomic(kaddr);
184
185 i++;
186 ptr += cur_size;
187 compressed_size -= cur_size;
188 }
189 btrfs_set_file_extent_compression(leaf, ei,
190 compress_type);
191 } else {
192 page = find_get_page(inode->i_mapping,
193 start >> PAGE_CACHE_SHIFT);
194 btrfs_set_file_extent_compression(leaf, ei, 0);
195 kaddr = kmap_atomic(page);
196 offset = start & (PAGE_CACHE_SIZE - 1);
197 write_extent_buffer(leaf, kaddr + offset, ptr, size);
198 kunmap_atomic(kaddr);
199 page_cache_release(page);
200 }
201 btrfs_mark_buffer_dirty(leaf);
202 btrfs_free_path(path);
203
204 /*
205 * we're an inline extent, so nobody can
206 * extend the file past i_size without locking
207 * a page we already have locked.
208 *
209 * We must do any isize and inode updates
210 * before we unlock the pages. Otherwise we
211 * could end up racing with unlink.
212 */
213 BTRFS_I(inode)->disk_i_size = inode->i_size;
214 ret = btrfs_update_inode(trans, root, inode);
215
216 return ret;
217 fail:
218 btrfs_free_path(path);
219 return err;
220 }
221
222
223 /*
224 * conditionally insert an inline extent into the file. This
225 * does the checks required to make sure the data is small enough
226 * to fit as an inline extent.
227 */
228 static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans,
229 struct btrfs_root *root,
230 struct inode *inode, u64 start, u64 end,
231 size_t compressed_size, int compress_type,
232 struct page **compressed_pages)
233 {
234 u64 isize = i_size_read(inode);
235 u64 actual_end = min(end + 1, isize);
236 u64 inline_len = actual_end - start;
237 u64 aligned_end = ALIGN(end, root->sectorsize);
238 u64 data_len = inline_len;
239 int ret;
240
241 if (compressed_size)
242 data_len = compressed_size;
243
244 if (start > 0 ||
245 actual_end >= PAGE_CACHE_SIZE ||
246 data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
247 (!compressed_size &&
248 (actual_end & (root->sectorsize - 1)) == 0) ||
249 end + 1 < isize ||
250 data_len > root->fs_info->max_inline) {
251 return 1;
252 }
253
254 ret = btrfs_drop_extents(trans, root, inode, start, aligned_end, 1);
255 if (ret)
256 return ret;
257
258 if (isize > actual_end)
259 inline_len = min_t(u64, isize, actual_end);
260 ret = insert_inline_extent(trans, root, inode, start,
261 inline_len, compressed_size,
262 compress_type, compressed_pages);
263 if (ret && ret != -ENOSPC) {
264 btrfs_abort_transaction(trans, root, ret);
265 return ret;
266 } else if (ret == -ENOSPC) {
267 return 1;
268 }
269
270 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
271 btrfs_delalloc_release_metadata(inode, end + 1 - start);
272 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
273 return 0;
274 }
275
276 struct async_extent {
277 u64 start;
278 u64 ram_size;
279 u64 compressed_size;
280 struct page **pages;
281 unsigned long nr_pages;
282 int compress_type;
283 struct list_head list;
284 };
285
286 struct async_cow {
287 struct inode *inode;
288 struct btrfs_root *root;
289 struct page *locked_page;
290 u64 start;
291 u64 end;
292 struct list_head extents;
293 struct btrfs_work work;
294 };
295
296 static noinline int add_async_extent(struct async_cow *cow,
297 u64 start, u64 ram_size,
298 u64 compressed_size,
299 struct page **pages,
300 unsigned long nr_pages,
301 int compress_type)
302 {
303 struct async_extent *async_extent;
304
305 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
306 BUG_ON(!async_extent); /* -ENOMEM */
307 async_extent->start = start;
308 async_extent->ram_size = ram_size;
309 async_extent->compressed_size = compressed_size;
310 async_extent->pages = pages;
311 async_extent->nr_pages = nr_pages;
312 async_extent->compress_type = compress_type;
313 list_add_tail(&async_extent->list, &cow->extents);
314 return 0;
315 }
316
317 /*
318 * we create compressed extents in two phases. The first
319 * phase compresses a range of pages that have already been
320 * locked (both pages and state bits are locked).
321 *
322 * This is done inside an ordered work queue, and the compression
323 * is spread across many cpus. The actual IO submission is step
324 * two, and the ordered work queue takes care of making sure that
325 * happens in the same order things were put onto the queue by
326 * writepages and friends.
327 *
328 * If this code finds it can't get good compression, it puts an
329 * entry onto the work queue to write the uncompressed bytes. This
330 * makes sure that both compressed inodes and uncompressed inodes
331 * are written in the same order that the flusher thread sent them
332 * down.
333 */
334 static noinline int compress_file_range(struct inode *inode,
335 struct page *locked_page,
336 u64 start, u64 end,
337 struct async_cow *async_cow,
338 int *num_added)
339 {
340 struct btrfs_root *root = BTRFS_I(inode)->root;
341 struct btrfs_trans_handle *trans;
342 u64 num_bytes;
343 u64 blocksize = root->sectorsize;
344 u64 actual_end;
345 u64 isize = i_size_read(inode);
346 int ret = 0;
347 struct page **pages = NULL;
348 unsigned long nr_pages;
349 unsigned long nr_pages_ret = 0;
350 unsigned long total_compressed = 0;
351 unsigned long total_in = 0;
352 unsigned long max_compressed = 128 * 1024;
353 unsigned long max_uncompressed = 128 * 1024;
354 int i;
355 int will_compress;
356 int compress_type = root->fs_info->compress_type;
357 int redirty = 0;
358
359 /* if this is a small write inside eof, kick off a defrag */
360 if ((end - start + 1) < 16 * 1024 &&
361 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
362 btrfs_add_inode_defrag(NULL, inode);
363
364 actual_end = min_t(u64, isize, end + 1);
365 again:
366 will_compress = 0;
367 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
368 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
369
370 /*
371 * we don't want to send crud past the end of i_size through
372 * compression, that's just a waste of CPU time. So, if the
373 * end of the file is before the start of our current
374 * requested range of bytes, we bail out to the uncompressed
375 * cleanup code that can deal with all of this.
376 *
377 * It isn't really the fastest way to fix things, but this is a
378 * very uncommon corner.
379 */
380 if (actual_end <= start)
381 goto cleanup_and_bail_uncompressed;
382
383 total_compressed = actual_end - start;
384
385 /* we want to make sure that amount of ram required to uncompress
386 * an extent is reasonable, so we limit the total size in ram
387 * of a compressed extent to 128k. This is a crucial number
388 * because it also controls how easily we can spread reads across
389 * cpus for decompression.
390 *
391 * We also want to make sure the amount of IO required to do
392 * a random read is reasonably small, so we limit the size of
393 * a compressed extent to 128k.
394 */
395 total_compressed = min(total_compressed, max_uncompressed);
396 num_bytes = ALIGN(end - start + 1, blocksize);
397 num_bytes = max(blocksize, num_bytes);
398 total_in = 0;
399 ret = 0;
400
401 /*
402 * we do compression for mount -o compress and when the
403 * inode has not been flagged as nocompress. This flag can
404 * change at any time if we discover bad compression ratios.
405 */
406 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) &&
407 (btrfs_test_opt(root, COMPRESS) ||
408 (BTRFS_I(inode)->force_compress) ||
409 (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) {
410 WARN_ON(pages);
411 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
412 if (!pages) {
413 /* just bail out to the uncompressed code */
414 goto cont;
415 }
416
417 if (BTRFS_I(inode)->force_compress)
418 compress_type = BTRFS_I(inode)->force_compress;
419
420 /*
421 * we need to call clear_page_dirty_for_io on each
422 * page in the range. Otherwise applications with the file
423 * mmap'd can wander in and change the page contents while
424 * we are compressing them.
425 *
426 * If the compression fails for any reason, we set the pages
427 * dirty again later on.
428 */
429 extent_range_clear_dirty_for_io(inode, start, end);
430 redirty = 1;
431 ret = btrfs_compress_pages(compress_type,
432 inode->i_mapping, start,
433 total_compressed, pages,
434 nr_pages, &nr_pages_ret,
435 &total_in,
436 &total_compressed,
437 max_compressed);
438
439 if (!ret) {
440 unsigned long offset = total_compressed &
441 (PAGE_CACHE_SIZE - 1);
442 struct page *page = pages[nr_pages_ret - 1];
443 char *kaddr;
444
445 /* zero the tail end of the last page, we might be
446 * sending it down to disk
447 */
448 if (offset) {
449 kaddr = kmap_atomic(page);
450 memset(kaddr + offset, 0,
451 PAGE_CACHE_SIZE - offset);
452 kunmap_atomic(kaddr);
453 }
454 will_compress = 1;
455 }
456 }
457 cont:
458 if (start == 0) {
459 trans = btrfs_join_transaction(root);
460 if (IS_ERR(trans)) {
461 ret = PTR_ERR(trans);
462 trans = NULL;
463 goto cleanup_and_out;
464 }
465 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
466
467 /* lets try to make an inline extent */
468 if (ret || total_in < (actual_end - start)) {
469 /* we didn't compress the entire range, try
470 * to make an uncompressed inline extent.
471 */
472 ret = cow_file_range_inline(trans, root, inode,
473 start, end, 0, 0, NULL);
474 } else {
475 /* try making a compressed inline extent */
476 ret = cow_file_range_inline(trans, root, inode,
477 start, end,
478 total_compressed,
479 compress_type, pages);
480 }
481 if (ret <= 0) {
482 /*
483 * inline extent creation worked or returned error,
484 * we don't need to create any more async work items.
485 * Unlock and free up our temp pages.
486 */
487 extent_clear_unlock_delalloc(inode,
488 &BTRFS_I(inode)->io_tree,
489 start, end, NULL,
490 EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
491 EXTENT_CLEAR_DELALLOC |
492 EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK);
493
494 btrfs_end_transaction(trans, root);
495 goto free_pages_out;
496 }
497 btrfs_end_transaction(trans, root);
498 }
499
500 if (will_compress) {
501 /*
502 * we aren't doing an inline extent round the compressed size
503 * up to a block size boundary so the allocator does sane
504 * things
505 */
506 total_compressed = ALIGN(total_compressed, blocksize);
507
508 /*
509 * one last check to make sure the compression is really a
510 * win, compare the page count read with the blocks on disk
511 */
512 total_in = ALIGN(total_in, PAGE_CACHE_SIZE);
513 if (total_compressed >= total_in) {
514 will_compress = 0;
515 } else {
516 num_bytes = total_in;
517 }
518 }
519 if (!will_compress && pages) {
520 /*
521 * the compression code ran but failed to make things smaller,
522 * free any pages it allocated and our page pointer array
523 */
524 for (i = 0; i < nr_pages_ret; i++) {
525 WARN_ON(pages[i]->mapping);
526 page_cache_release(pages[i]);
527 }
528 kfree(pages);
529 pages = NULL;
530 total_compressed = 0;
531 nr_pages_ret = 0;
532
533 /* flag the file so we don't compress in the future */
534 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
535 !(BTRFS_I(inode)->force_compress)) {
536 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
537 }
538 }
539 if (will_compress) {
540 *num_added += 1;
541
542 /* the async work queues will take care of doing actual
543 * allocation on disk for these compressed pages,
544 * and will submit them to the elevator.
545 */
546 add_async_extent(async_cow, start, num_bytes,
547 total_compressed, pages, nr_pages_ret,
548 compress_type);
549
550 if (start + num_bytes < end) {
551 start += num_bytes;
552 pages = NULL;
553 cond_resched();
554 goto again;
555 }
556 } else {
557 cleanup_and_bail_uncompressed:
558 /*
559 * No compression, but we still need to write the pages in
560 * the file we've been given so far. redirty the locked
561 * page if it corresponds to our extent and set things up
562 * for the async work queue to run cow_file_range to do
563 * the normal delalloc dance
564 */
565 if (page_offset(locked_page) >= start &&
566 page_offset(locked_page) <= end) {
567 __set_page_dirty_nobuffers(locked_page);
568 /* unlocked later on in the async handlers */
569 }
570 if (redirty)
571 extent_range_redirty_for_io(inode, start, end);
572 add_async_extent(async_cow, start, end - start + 1,
573 0, NULL, 0, BTRFS_COMPRESS_NONE);
574 *num_added += 1;
575 }
576
577 out:
578 return ret;
579
580 free_pages_out:
581 for (i = 0; i < nr_pages_ret; i++) {
582 WARN_ON(pages[i]->mapping);
583 page_cache_release(pages[i]);
584 }
585 kfree(pages);
586
587 goto out;
588
589 cleanup_and_out:
590 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
591 start, end, NULL,
592 EXTENT_CLEAR_UNLOCK_PAGE |
593 EXTENT_CLEAR_DIRTY |
594 EXTENT_CLEAR_DELALLOC |
595 EXTENT_SET_WRITEBACK |
596 EXTENT_END_WRITEBACK);
597 if (!trans || IS_ERR(trans))
598 btrfs_error(root->fs_info, ret, "Failed to join transaction");
599 else
600 btrfs_abort_transaction(trans, root, ret);
601 goto free_pages_out;
602 }
603
604 /*
605 * phase two of compressed writeback. This is the ordered portion
606 * of the code, which only gets called in the order the work was
607 * queued. We walk all the async extents created by compress_file_range
608 * and send them down to the disk.
609 */
610 static noinline int submit_compressed_extents(struct inode *inode,
611 struct async_cow *async_cow)
612 {
613 struct async_extent *async_extent;
614 u64 alloc_hint = 0;
615 struct btrfs_trans_handle *trans;
616 struct btrfs_key ins;
617 struct extent_map *em;
618 struct btrfs_root *root = BTRFS_I(inode)->root;
619 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
620 struct extent_io_tree *io_tree;
621 int ret = 0;
622
623 if (list_empty(&async_cow->extents))
624 return 0;
625
626 again:
627 while (!list_empty(&async_cow->extents)) {
628 async_extent = list_entry(async_cow->extents.next,
629 struct async_extent, list);
630 list_del(&async_extent->list);
631
632 io_tree = &BTRFS_I(inode)->io_tree;
633
634 retry:
635 /* did the compression code fall back to uncompressed IO? */
636 if (!async_extent->pages) {
637 int page_started = 0;
638 unsigned long nr_written = 0;
639
640 lock_extent(io_tree, async_extent->start,
641 async_extent->start +
642 async_extent->ram_size - 1);
643
644 /* allocate blocks */
645 ret = cow_file_range(inode, async_cow->locked_page,
646 async_extent->start,
647 async_extent->start +
648 async_extent->ram_size - 1,
649 &page_started, &nr_written, 0);
650
651 /* JDM XXX */
652
653 /*
654 * if page_started, cow_file_range inserted an
655 * inline extent and took care of all the unlocking
656 * and IO for us. Otherwise, we need to submit
657 * all those pages down to the drive.
658 */
659 if (!page_started && !ret)
660 extent_write_locked_range(io_tree,
661 inode, async_extent->start,
662 async_extent->start +
663 async_extent->ram_size - 1,
664 btrfs_get_extent,
665 WB_SYNC_ALL);
666 else if (ret)
667 unlock_page(async_cow->locked_page);
668 kfree(async_extent);
669 cond_resched();
670 continue;
671 }
672
673 lock_extent(io_tree, async_extent->start,
674 async_extent->start + async_extent->ram_size - 1);
675
676 trans = btrfs_join_transaction(root);
677 if (IS_ERR(trans)) {
678 ret = PTR_ERR(trans);
679 } else {
680 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
681 ret = btrfs_reserve_extent(trans, root,
682 async_extent->compressed_size,
683 async_extent->compressed_size,
684 0, alloc_hint, &ins, 1);
685 if (ret && ret != -ENOSPC)
686 btrfs_abort_transaction(trans, root, ret);
687 btrfs_end_transaction(trans, root);
688 }
689
690 if (ret) {
691 int i;
692
693 for (i = 0; i < async_extent->nr_pages; i++) {
694 WARN_ON(async_extent->pages[i]->mapping);
695 page_cache_release(async_extent->pages[i]);
696 }
697 kfree(async_extent->pages);
698 async_extent->nr_pages = 0;
699 async_extent->pages = NULL;
700
701 if (ret == -ENOSPC)
702 goto retry;
703 goto out_free;
704 }
705
706 /*
707 * here we're doing allocation and writeback of the
708 * compressed pages
709 */
710 btrfs_drop_extent_cache(inode, async_extent->start,
711 async_extent->start +
712 async_extent->ram_size - 1, 0);
713
714 em = alloc_extent_map();
715 if (!em)
716 goto out_free_reserve;
717 em->start = async_extent->start;
718 em->len = async_extent->ram_size;
719 em->orig_start = em->start;
720 em->mod_start = em->start;
721 em->mod_len = em->len;
722
723 em->block_start = ins.objectid;
724 em->block_len = ins.offset;
725 em->orig_block_len = ins.offset;
726 em->ram_bytes = async_extent->ram_size;
727 em->bdev = root->fs_info->fs_devices->latest_bdev;
728 em->compress_type = async_extent->compress_type;
729 set_bit(EXTENT_FLAG_PINNED, &em->flags);
730 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
731 em->generation = -1;
732
733 while (1) {
734 write_lock(&em_tree->lock);
735 ret = add_extent_mapping(em_tree, em);
736 if (!ret)
737 list_move(&em->list,
738 &em_tree->modified_extents);
739 write_unlock(&em_tree->lock);
740 if (ret != -EEXIST) {
741 free_extent_map(em);
742 break;
743 }
744 btrfs_drop_extent_cache(inode, async_extent->start,
745 async_extent->start +
746 async_extent->ram_size - 1, 0);
747 }
748
749 if (ret)
750 goto out_free_reserve;
751
752 ret = btrfs_add_ordered_extent_compress(inode,
753 async_extent->start,
754 ins.objectid,
755 async_extent->ram_size,
756 ins.offset,
757 BTRFS_ORDERED_COMPRESSED,
758 async_extent->compress_type);
759 if (ret)
760 goto out_free_reserve;
761
762 /*
763 * clear dirty, set writeback and unlock the pages.
764 */
765 extent_clear_unlock_delalloc(inode,
766 &BTRFS_I(inode)->io_tree,
767 async_extent->start,
768 async_extent->start +
769 async_extent->ram_size - 1,
770 NULL, EXTENT_CLEAR_UNLOCK_PAGE |
771 EXTENT_CLEAR_UNLOCK |
772 EXTENT_CLEAR_DELALLOC |
773 EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK);
774
775 ret = btrfs_submit_compressed_write(inode,
776 async_extent->start,
777 async_extent->ram_size,
778 ins.objectid,
779 ins.offset, async_extent->pages,
780 async_extent->nr_pages);
781 alloc_hint = ins.objectid + ins.offset;
782 kfree(async_extent);
783 if (ret)
784 goto out;
785 cond_resched();
786 }
787 ret = 0;
788 out:
789 return ret;
790 out_free_reserve:
791 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
792 out_free:
793 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
794 async_extent->start,
795 async_extent->start +
796 async_extent->ram_size - 1,
797 NULL, EXTENT_CLEAR_UNLOCK_PAGE |
798 EXTENT_CLEAR_UNLOCK |
799 EXTENT_CLEAR_DELALLOC |
800 EXTENT_CLEAR_DIRTY |
801 EXTENT_SET_WRITEBACK |
802 EXTENT_END_WRITEBACK);
803 kfree(async_extent);
804 goto again;
805 }
806
807 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
808 u64 num_bytes)
809 {
810 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
811 struct extent_map *em;
812 u64 alloc_hint = 0;
813
814 read_lock(&em_tree->lock);
815 em = search_extent_mapping(em_tree, start, num_bytes);
816 if (em) {
817 /*
818 * if block start isn't an actual block number then find the
819 * first block in this inode and use that as a hint. If that
820 * block is also bogus then just don't worry about it.
821 */
822 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
823 free_extent_map(em);
824 em = search_extent_mapping(em_tree, 0, 0);
825 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
826 alloc_hint = em->block_start;
827 if (em)
828 free_extent_map(em);
829 } else {
830 alloc_hint = em->block_start;
831 free_extent_map(em);
832 }
833 }
834 read_unlock(&em_tree->lock);
835
836 return alloc_hint;
837 }
838
839 /*
840 * when extent_io.c finds a delayed allocation range in the file,
841 * the call backs end up in this code. The basic idea is to
842 * allocate extents on disk for the range, and create ordered data structs
843 * in ram to track those extents.
844 *
845 * locked_page is the page that writepage had locked already. We use
846 * it to make sure we don't do extra locks or unlocks.
847 *
848 * *page_started is set to one if we unlock locked_page and do everything
849 * required to start IO on it. It may be clean and already done with
850 * IO when we return.
851 */
852 static noinline int __cow_file_range(struct btrfs_trans_handle *trans,
853 struct inode *inode,
854 struct btrfs_root *root,
855 struct page *locked_page,
856 u64 start, u64 end, int *page_started,
857 unsigned long *nr_written,
858 int unlock)
859 {
860 u64 alloc_hint = 0;
861 u64 num_bytes;
862 unsigned long ram_size;
863 u64 disk_num_bytes;
864 u64 cur_alloc_size;
865 u64 blocksize = root->sectorsize;
866 struct btrfs_key ins;
867 struct extent_map *em;
868 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
869 int ret = 0;
870
871 BUG_ON(btrfs_is_free_space_inode(inode));
872
873 num_bytes = ALIGN(end - start + 1, blocksize);
874 num_bytes = max(blocksize, num_bytes);
875 disk_num_bytes = num_bytes;
876
877 /* if this is a small write inside eof, kick off defrag */
878 if (num_bytes < 64 * 1024 &&
879 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
880 btrfs_add_inode_defrag(trans, inode);
881
882 if (start == 0) {
883 /* lets try to make an inline extent */
884 ret = cow_file_range_inline(trans, root, inode,
885 start, end, 0, 0, NULL);
886 if (ret == 0) {
887 extent_clear_unlock_delalloc(inode,
888 &BTRFS_I(inode)->io_tree,
889 start, end, NULL,
890 EXTENT_CLEAR_UNLOCK_PAGE |
891 EXTENT_CLEAR_UNLOCK |
892 EXTENT_CLEAR_DELALLOC |
893 EXTENT_CLEAR_DIRTY |
894 EXTENT_SET_WRITEBACK |
895 EXTENT_END_WRITEBACK);
896
897 *nr_written = *nr_written +
898 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
899 *page_started = 1;
900 goto out;
901 } else if (ret < 0) {
902 btrfs_abort_transaction(trans, root, ret);
903 goto out_unlock;
904 }
905 }
906
907 BUG_ON(disk_num_bytes >
908 btrfs_super_total_bytes(root->fs_info->super_copy));
909
910 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
911 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
912
913 while (disk_num_bytes > 0) {
914 unsigned long op;
915
916 cur_alloc_size = disk_num_bytes;
917 ret = btrfs_reserve_extent(trans, root, cur_alloc_size,
918 root->sectorsize, 0, alloc_hint,
919 &ins, 1);
920 if (ret < 0) {
921 btrfs_abort_transaction(trans, root, ret);
922 goto out_unlock;
923 }
924
925 em = alloc_extent_map();
926 BUG_ON(!em); /* -ENOMEM */
927 em->start = start;
928 em->orig_start = em->start;
929 ram_size = ins.offset;
930 em->len = ins.offset;
931 em->mod_start = em->start;
932 em->mod_len = em->len;
933
934 em->block_start = ins.objectid;
935 em->block_len = ins.offset;
936 em->orig_block_len = ins.offset;
937 em->ram_bytes = ram_size;
938 em->bdev = root->fs_info->fs_devices->latest_bdev;
939 set_bit(EXTENT_FLAG_PINNED, &em->flags);
940 em->generation = -1;
941
942 while (1) {
943 write_lock(&em_tree->lock);
944 ret = add_extent_mapping(em_tree, em);
945 if (!ret)
946 list_move(&em->list,
947 &em_tree->modified_extents);
948 write_unlock(&em_tree->lock);
949 if (ret != -EEXIST) {
950 free_extent_map(em);
951 break;
952 }
953 btrfs_drop_extent_cache(inode, start,
954 start + ram_size - 1, 0);
955 }
956
957 cur_alloc_size = ins.offset;
958 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
959 ram_size, cur_alloc_size, 0);
960 BUG_ON(ret); /* -ENOMEM */
961
962 if (root->root_key.objectid ==
963 BTRFS_DATA_RELOC_TREE_OBJECTID) {
964 ret = btrfs_reloc_clone_csums(inode, start,
965 cur_alloc_size);
966 if (ret) {
967 btrfs_abort_transaction(trans, root, ret);
968 goto out_unlock;
969 }
970 }
971
972 if (disk_num_bytes < cur_alloc_size)
973 break;
974
975 /* we're not doing compressed IO, don't unlock the first
976 * page (which the caller expects to stay locked), don't
977 * clear any dirty bits and don't set any writeback bits
978 *
979 * Do set the Private2 bit so we know this page was properly
980 * setup for writepage
981 */
982 op = unlock ? EXTENT_CLEAR_UNLOCK_PAGE : 0;
983 op |= EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
984 EXTENT_SET_PRIVATE2;
985
986 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
987 start, start + ram_size - 1,
988 locked_page, op);
989 disk_num_bytes -= cur_alloc_size;
990 num_bytes -= cur_alloc_size;
991 alloc_hint = ins.objectid + ins.offset;
992 start += cur_alloc_size;
993 }
994 out:
995 return ret;
996
997 out_unlock:
998 extent_clear_unlock_delalloc(inode,
999 &BTRFS_I(inode)->io_tree,
1000 start, end, locked_page,
1001 EXTENT_CLEAR_UNLOCK_PAGE |
1002 EXTENT_CLEAR_UNLOCK |
1003 EXTENT_CLEAR_DELALLOC |
1004 EXTENT_CLEAR_DIRTY |
1005 EXTENT_SET_WRITEBACK |
1006 EXTENT_END_WRITEBACK);
1007
1008 goto out;
1009 }
1010
1011 static noinline int cow_file_range(struct inode *inode,
1012 struct page *locked_page,
1013 u64 start, u64 end, int *page_started,
1014 unsigned long *nr_written,
1015 int unlock)
1016 {
1017 struct btrfs_trans_handle *trans;
1018 struct btrfs_root *root = BTRFS_I(inode)->root;
1019 int ret;
1020
1021 trans = btrfs_join_transaction(root);
1022 if (IS_ERR(trans)) {
1023 extent_clear_unlock_delalloc(inode,
1024 &BTRFS_I(inode)->io_tree,
1025 start, end, locked_page,
1026 EXTENT_CLEAR_UNLOCK_PAGE |
1027 EXTENT_CLEAR_UNLOCK |
1028 EXTENT_CLEAR_DELALLOC |
1029 EXTENT_CLEAR_DIRTY |
1030 EXTENT_SET_WRITEBACK |
1031 EXTENT_END_WRITEBACK);
1032 return PTR_ERR(trans);
1033 }
1034 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1035
1036 ret = __cow_file_range(trans, inode, root, locked_page, start, end,
1037 page_started, nr_written, unlock);
1038
1039 btrfs_end_transaction(trans, root);
1040
1041 return ret;
1042 }
1043
1044 /*
1045 * work queue call back to started compression on a file and pages
1046 */
1047 static noinline void async_cow_start(struct btrfs_work *work)
1048 {
1049 struct async_cow *async_cow;
1050 int num_added = 0;
1051 async_cow = container_of(work, struct async_cow, work);
1052
1053 compress_file_range(async_cow->inode, async_cow->locked_page,
1054 async_cow->start, async_cow->end, async_cow,
1055 &num_added);
1056 if (num_added == 0) {
1057 btrfs_add_delayed_iput(async_cow->inode);
1058 async_cow->inode = NULL;
1059 }
1060 }
1061
1062 /*
1063 * work queue call back to submit previously compressed pages
1064 */
1065 static noinline void async_cow_submit(struct btrfs_work *work)
1066 {
1067 struct async_cow *async_cow;
1068 struct btrfs_root *root;
1069 unsigned long nr_pages;
1070
1071 async_cow = container_of(work, struct async_cow, work);
1072
1073 root = async_cow->root;
1074 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
1075 PAGE_CACHE_SHIFT;
1076
1077 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1078 5 * 1024 * 1024 &&
1079 waitqueue_active(&root->fs_info->async_submit_wait))
1080 wake_up(&root->fs_info->async_submit_wait);
1081
1082 if (async_cow->inode)
1083 submit_compressed_extents(async_cow->inode, async_cow);
1084 }
1085
1086 static noinline void async_cow_free(struct btrfs_work *work)
1087 {
1088 struct async_cow *async_cow;
1089 async_cow = container_of(work, struct async_cow, work);
1090 if (async_cow->inode)
1091 btrfs_add_delayed_iput(async_cow->inode);
1092 kfree(async_cow);
1093 }
1094
1095 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1096 u64 start, u64 end, int *page_started,
1097 unsigned long *nr_written)
1098 {
1099 struct async_cow *async_cow;
1100 struct btrfs_root *root = BTRFS_I(inode)->root;
1101 unsigned long nr_pages;
1102 u64 cur_end;
1103 int limit = 10 * 1024 * 1024;
1104
1105 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1106 1, 0, NULL, GFP_NOFS);
1107 while (start < end) {
1108 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1109 BUG_ON(!async_cow); /* -ENOMEM */
1110 async_cow->inode = igrab(inode);
1111 async_cow->root = root;
1112 async_cow->locked_page = locked_page;
1113 async_cow->start = start;
1114
1115 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
1116 cur_end = end;
1117 else
1118 cur_end = min(end, start + 512 * 1024 - 1);
1119
1120 async_cow->end = cur_end;
1121 INIT_LIST_HEAD(&async_cow->extents);
1122
1123 async_cow->work.func = async_cow_start;
1124 async_cow->work.ordered_func = async_cow_submit;
1125 async_cow->work.ordered_free = async_cow_free;
1126 async_cow->work.flags = 0;
1127
1128 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
1129 PAGE_CACHE_SHIFT;
1130 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1131
1132 btrfs_queue_worker(&root->fs_info->delalloc_workers,
1133 &async_cow->work);
1134
1135 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1136 wait_event(root->fs_info->async_submit_wait,
1137 (atomic_read(&root->fs_info->async_delalloc_pages) <
1138 limit));
1139 }
1140
1141 while (atomic_read(&root->fs_info->async_submit_draining) &&
1142 atomic_read(&root->fs_info->async_delalloc_pages)) {
1143 wait_event(root->fs_info->async_submit_wait,
1144 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1145 0));
1146 }
1147
1148 *nr_written += nr_pages;
1149 start = cur_end + 1;
1150 }
1151 *page_started = 1;
1152 return 0;
1153 }
1154
1155 static noinline int csum_exist_in_range(struct btrfs_root *root,
1156 u64 bytenr, u64 num_bytes)
1157 {
1158 int ret;
1159 struct btrfs_ordered_sum *sums;
1160 LIST_HEAD(list);
1161
1162 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1163 bytenr + num_bytes - 1, &list, 0);
1164 if (ret == 0 && list_empty(&list))
1165 return 0;
1166
1167 while (!list_empty(&list)) {
1168 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1169 list_del(&sums->list);
1170 kfree(sums);
1171 }
1172 return 1;
1173 }
1174
1175 /*
1176 * when nowcow writeback call back. This checks for snapshots or COW copies
1177 * of the extents that exist in the file, and COWs the file as required.
1178 *
1179 * If no cow copies or snapshots exist, we write directly to the existing
1180 * blocks on disk
1181 */
1182 static noinline int run_delalloc_nocow(struct inode *inode,
1183 struct page *locked_page,
1184 u64 start, u64 end, int *page_started, int force,
1185 unsigned long *nr_written)
1186 {
1187 struct btrfs_root *root = BTRFS_I(inode)->root;
1188 struct btrfs_trans_handle *trans;
1189 struct extent_buffer *leaf;
1190 struct btrfs_path *path;
1191 struct btrfs_file_extent_item *fi;
1192 struct btrfs_key found_key;
1193 u64 cow_start;
1194 u64 cur_offset;
1195 u64 extent_end;
1196 u64 extent_offset;
1197 u64 disk_bytenr;
1198 u64 num_bytes;
1199 u64 disk_num_bytes;
1200 u64 ram_bytes;
1201 int extent_type;
1202 int ret, err;
1203 int type;
1204 int nocow;
1205 int check_prev = 1;
1206 bool nolock;
1207 u64 ino = btrfs_ino(inode);
1208
1209 path = btrfs_alloc_path();
1210 if (!path) {
1211 extent_clear_unlock_delalloc(inode,
1212 &BTRFS_I(inode)->io_tree,
1213 start, end, locked_page,
1214 EXTENT_CLEAR_UNLOCK_PAGE |
1215 EXTENT_CLEAR_UNLOCK |
1216 EXTENT_CLEAR_DELALLOC |
1217 EXTENT_CLEAR_DIRTY |
1218 EXTENT_SET_WRITEBACK |
1219 EXTENT_END_WRITEBACK);
1220 return -ENOMEM;
1221 }
1222
1223 nolock = btrfs_is_free_space_inode(inode);
1224
1225 if (nolock)
1226 trans = btrfs_join_transaction_nolock(root);
1227 else
1228 trans = btrfs_join_transaction(root);
1229
1230 if (IS_ERR(trans)) {
1231 extent_clear_unlock_delalloc(inode,
1232 &BTRFS_I(inode)->io_tree,
1233 start, end, locked_page,
1234 EXTENT_CLEAR_UNLOCK_PAGE |
1235 EXTENT_CLEAR_UNLOCK |
1236 EXTENT_CLEAR_DELALLOC |
1237 EXTENT_CLEAR_DIRTY |
1238 EXTENT_SET_WRITEBACK |
1239 EXTENT_END_WRITEBACK);
1240 btrfs_free_path(path);
1241 return PTR_ERR(trans);
1242 }
1243
1244 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1245
1246 cow_start = (u64)-1;
1247 cur_offset = start;
1248 while (1) {
1249 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1250 cur_offset, 0);
1251 if (ret < 0) {
1252 btrfs_abort_transaction(trans, root, ret);
1253 goto error;
1254 }
1255 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1256 leaf = path->nodes[0];
1257 btrfs_item_key_to_cpu(leaf, &found_key,
1258 path->slots[0] - 1);
1259 if (found_key.objectid == ino &&
1260 found_key.type == BTRFS_EXTENT_DATA_KEY)
1261 path->slots[0]--;
1262 }
1263 check_prev = 0;
1264 next_slot:
1265 leaf = path->nodes[0];
1266 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1267 ret = btrfs_next_leaf(root, path);
1268 if (ret < 0) {
1269 btrfs_abort_transaction(trans, root, ret);
1270 goto error;
1271 }
1272 if (ret > 0)
1273 break;
1274 leaf = path->nodes[0];
1275 }
1276
1277 nocow = 0;
1278 disk_bytenr = 0;
1279 num_bytes = 0;
1280 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1281
1282 if (found_key.objectid > ino ||
1283 found_key.type > BTRFS_EXTENT_DATA_KEY ||
1284 found_key.offset > end)
1285 break;
1286
1287 if (found_key.offset > cur_offset) {
1288 extent_end = found_key.offset;
1289 extent_type = 0;
1290 goto out_check;
1291 }
1292
1293 fi = btrfs_item_ptr(leaf, path->slots[0],
1294 struct btrfs_file_extent_item);
1295 extent_type = btrfs_file_extent_type(leaf, fi);
1296
1297 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1298 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1299 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1300 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1301 extent_offset = btrfs_file_extent_offset(leaf, fi);
1302 extent_end = found_key.offset +
1303 btrfs_file_extent_num_bytes(leaf, fi);
1304 disk_num_bytes =
1305 btrfs_file_extent_disk_num_bytes(leaf, fi);
1306 if (extent_end <= start) {
1307 path->slots[0]++;
1308 goto next_slot;
1309 }
1310 if (disk_bytenr == 0)
1311 goto out_check;
1312 if (btrfs_file_extent_compression(leaf, fi) ||
1313 btrfs_file_extent_encryption(leaf, fi) ||
1314 btrfs_file_extent_other_encoding(leaf, fi))
1315 goto out_check;
1316 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1317 goto out_check;
1318 if (btrfs_extent_readonly(root, disk_bytenr))
1319 goto out_check;
1320 if (btrfs_cross_ref_exist(trans, root, ino,
1321 found_key.offset -
1322 extent_offset, disk_bytenr))
1323 goto out_check;
1324 disk_bytenr += extent_offset;
1325 disk_bytenr += cur_offset - found_key.offset;
1326 num_bytes = min(end + 1, extent_end) - cur_offset;
1327 /*
1328 * force cow if csum exists in the range.
1329 * this ensure that csum for a given extent are
1330 * either valid or do not exist.
1331 */
1332 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1333 goto out_check;
1334 nocow = 1;
1335 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1336 extent_end = found_key.offset +
1337 btrfs_file_extent_inline_len(leaf, fi);
1338 extent_end = ALIGN(extent_end, root->sectorsize);
1339 } else {
1340 BUG_ON(1);
1341 }
1342 out_check:
1343 if (extent_end <= start) {
1344 path->slots[0]++;
1345 goto next_slot;
1346 }
1347 if (!nocow) {
1348 if (cow_start == (u64)-1)
1349 cow_start = cur_offset;
1350 cur_offset = extent_end;
1351 if (cur_offset > end)
1352 break;
1353 path->slots[0]++;
1354 goto next_slot;
1355 }
1356
1357 btrfs_release_path(path);
1358 if (cow_start != (u64)-1) {
1359 ret = __cow_file_range(trans, inode, root, locked_page,
1360 cow_start, found_key.offset - 1,
1361 page_started, nr_written, 1);
1362 if (ret) {
1363 btrfs_abort_transaction(trans, root, ret);
1364 goto error;
1365 }
1366 cow_start = (u64)-1;
1367 }
1368
1369 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1370 struct extent_map *em;
1371 struct extent_map_tree *em_tree;
1372 em_tree = &BTRFS_I(inode)->extent_tree;
1373 em = alloc_extent_map();
1374 BUG_ON(!em); /* -ENOMEM */
1375 em->start = cur_offset;
1376 em->orig_start = found_key.offset - extent_offset;
1377 em->len = num_bytes;
1378 em->block_len = num_bytes;
1379 em->block_start = disk_bytenr;
1380 em->orig_block_len = disk_num_bytes;
1381 em->ram_bytes = ram_bytes;
1382 em->bdev = root->fs_info->fs_devices->latest_bdev;
1383 em->mod_start = em->start;
1384 em->mod_len = em->len;
1385 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1386 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1387 em->generation = -1;
1388 while (1) {
1389 write_lock(&em_tree->lock);
1390 ret = add_extent_mapping(em_tree, em);
1391 if (!ret)
1392 list_move(&em->list,
1393 &em_tree->modified_extents);
1394 write_unlock(&em_tree->lock);
1395 if (ret != -EEXIST) {
1396 free_extent_map(em);
1397 break;
1398 }
1399 btrfs_drop_extent_cache(inode, em->start,
1400 em->start + em->len - 1, 0);
1401 }
1402 type = BTRFS_ORDERED_PREALLOC;
1403 } else {
1404 type = BTRFS_ORDERED_NOCOW;
1405 }
1406
1407 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1408 num_bytes, num_bytes, type);
1409 BUG_ON(ret); /* -ENOMEM */
1410
1411 if (root->root_key.objectid ==
1412 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1413 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1414 num_bytes);
1415 if (ret) {
1416 btrfs_abort_transaction(trans, root, ret);
1417 goto error;
1418 }
1419 }
1420
1421 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
1422 cur_offset, cur_offset + num_bytes - 1,
1423 locked_page, EXTENT_CLEAR_UNLOCK_PAGE |
1424 EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
1425 EXTENT_SET_PRIVATE2);
1426 cur_offset = extent_end;
1427 if (cur_offset > end)
1428 break;
1429 }
1430 btrfs_release_path(path);
1431
1432 if (cur_offset <= end && cow_start == (u64)-1) {
1433 cow_start = cur_offset;
1434 cur_offset = end;
1435 }
1436
1437 if (cow_start != (u64)-1) {
1438 ret = __cow_file_range(trans, inode, root, locked_page,
1439 cow_start, end,
1440 page_started, nr_written, 1);
1441 if (ret) {
1442 btrfs_abort_transaction(trans, root, ret);
1443 goto error;
1444 }
1445 }
1446
1447 error:
1448 err = btrfs_end_transaction(trans, root);
1449 if (!ret)
1450 ret = err;
1451
1452 if (ret && cur_offset < end)
1453 extent_clear_unlock_delalloc(inode,
1454 &BTRFS_I(inode)->io_tree,
1455 cur_offset, end, locked_page,
1456 EXTENT_CLEAR_UNLOCK_PAGE |
1457 EXTENT_CLEAR_UNLOCK |
1458 EXTENT_CLEAR_DELALLOC |
1459 EXTENT_CLEAR_DIRTY |
1460 EXTENT_SET_WRITEBACK |
1461 EXTENT_END_WRITEBACK);
1462
1463 btrfs_free_path(path);
1464 return ret;
1465 }
1466
1467 /*
1468 * extent_io.c call back to do delayed allocation processing
1469 */
1470 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1471 u64 start, u64 end, int *page_started,
1472 unsigned long *nr_written)
1473 {
1474 int ret;
1475 struct btrfs_root *root = BTRFS_I(inode)->root;
1476
1477 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) {
1478 ret = run_delalloc_nocow(inode, locked_page, start, end,
1479 page_started, 1, nr_written);
1480 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC) {
1481 ret = run_delalloc_nocow(inode, locked_page, start, end,
1482 page_started, 0, nr_written);
1483 } else if (!btrfs_test_opt(root, COMPRESS) &&
1484 !(BTRFS_I(inode)->force_compress) &&
1485 !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS)) {
1486 ret = cow_file_range(inode, locked_page, start, end,
1487 page_started, nr_written, 1);
1488 } else {
1489 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1490 &BTRFS_I(inode)->runtime_flags);
1491 ret = cow_file_range_async(inode, locked_page, start, end,
1492 page_started, nr_written);
1493 }
1494 return ret;
1495 }
1496
1497 static void btrfs_split_extent_hook(struct inode *inode,
1498 struct extent_state *orig, u64 split)
1499 {
1500 /* not delalloc, ignore it */
1501 if (!(orig->state & EXTENT_DELALLOC))
1502 return;
1503
1504 spin_lock(&BTRFS_I(inode)->lock);
1505 BTRFS_I(inode)->outstanding_extents++;
1506 spin_unlock(&BTRFS_I(inode)->lock);
1507 }
1508
1509 /*
1510 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1511 * extents so we can keep track of new extents that are just merged onto old
1512 * extents, such as when we are doing sequential writes, so we can properly
1513 * account for the metadata space we'll need.
1514 */
1515 static void btrfs_merge_extent_hook(struct inode *inode,
1516 struct extent_state *new,
1517 struct extent_state *other)
1518 {
1519 /* not delalloc, ignore it */
1520 if (!(other->state & EXTENT_DELALLOC))
1521 return;
1522
1523 spin_lock(&BTRFS_I(inode)->lock);
1524 BTRFS_I(inode)->outstanding_extents--;
1525 spin_unlock(&BTRFS_I(inode)->lock);
1526 }
1527
1528 /*
1529 * extent_io.c set_bit_hook, used to track delayed allocation
1530 * bytes in this file, and to maintain the list of inodes that
1531 * have pending delalloc work to be done.
1532 */
1533 static void btrfs_set_bit_hook(struct inode *inode,
1534 struct extent_state *state, int *bits)
1535 {
1536
1537 /*
1538 * set_bit and clear bit hooks normally require _irqsave/restore
1539 * but in this case, we are only testing for the DELALLOC
1540 * bit, which is only set or cleared with irqs on
1541 */
1542 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1543 struct btrfs_root *root = BTRFS_I(inode)->root;
1544 u64 len = state->end + 1 - state->start;
1545 bool do_list = !btrfs_is_free_space_inode(inode);
1546
1547 if (*bits & EXTENT_FIRST_DELALLOC) {
1548 *bits &= ~EXTENT_FIRST_DELALLOC;
1549 } else {
1550 spin_lock(&BTRFS_I(inode)->lock);
1551 BTRFS_I(inode)->outstanding_extents++;
1552 spin_unlock(&BTRFS_I(inode)->lock);
1553 }
1554
1555 __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
1556 root->fs_info->delalloc_batch);
1557 spin_lock(&BTRFS_I(inode)->lock);
1558 BTRFS_I(inode)->delalloc_bytes += len;
1559 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1560 &BTRFS_I(inode)->runtime_flags)) {
1561 spin_lock(&root->fs_info->delalloc_lock);
1562 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1563 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1564 &root->fs_info->delalloc_inodes);
1565 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1566 &BTRFS_I(inode)->runtime_flags);
1567 }
1568 spin_unlock(&root->fs_info->delalloc_lock);
1569 }
1570 spin_unlock(&BTRFS_I(inode)->lock);
1571 }
1572 }
1573
1574 /*
1575 * extent_io.c clear_bit_hook, see set_bit_hook for why
1576 */
1577 static void btrfs_clear_bit_hook(struct inode *inode,
1578 struct extent_state *state, int *bits)
1579 {
1580 /*
1581 * set_bit and clear bit hooks normally require _irqsave/restore
1582 * but in this case, we are only testing for the DELALLOC
1583 * bit, which is only set or cleared with irqs on
1584 */
1585 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1586 struct btrfs_root *root = BTRFS_I(inode)->root;
1587 u64 len = state->end + 1 - state->start;
1588 bool do_list = !btrfs_is_free_space_inode(inode);
1589
1590 if (*bits & EXTENT_FIRST_DELALLOC) {
1591 *bits &= ~EXTENT_FIRST_DELALLOC;
1592 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1593 spin_lock(&BTRFS_I(inode)->lock);
1594 BTRFS_I(inode)->outstanding_extents--;
1595 spin_unlock(&BTRFS_I(inode)->lock);
1596 }
1597
1598 if (*bits & EXTENT_DO_ACCOUNTING)
1599 btrfs_delalloc_release_metadata(inode, len);
1600
1601 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1602 && do_list)
1603 btrfs_free_reserved_data_space(inode, len);
1604
1605 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
1606 root->fs_info->delalloc_batch);
1607 spin_lock(&BTRFS_I(inode)->lock);
1608 BTRFS_I(inode)->delalloc_bytes -= len;
1609 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1610 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1611 &BTRFS_I(inode)->runtime_flags)) {
1612 spin_lock(&root->fs_info->delalloc_lock);
1613 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1614 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1615 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1616 &BTRFS_I(inode)->runtime_flags);
1617 }
1618 spin_unlock(&root->fs_info->delalloc_lock);
1619 }
1620 spin_unlock(&BTRFS_I(inode)->lock);
1621 }
1622 }
1623
1624 /*
1625 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1626 * we don't create bios that span stripes or chunks
1627 */
1628 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
1629 size_t size, struct bio *bio,
1630 unsigned long bio_flags)
1631 {
1632 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1633 u64 logical = (u64)bio->bi_sector << 9;
1634 u64 length = 0;
1635 u64 map_length;
1636 int ret;
1637
1638 if (bio_flags & EXTENT_BIO_COMPRESSED)
1639 return 0;
1640
1641 length = bio->bi_size;
1642 map_length = length;
1643 ret = btrfs_map_block(root->fs_info, rw, logical,
1644 &map_length, NULL, 0);
1645 /* Will always return 0 with map_multi == NULL */
1646 BUG_ON(ret < 0);
1647 if (map_length < length + size)
1648 return 1;
1649 return 0;
1650 }
1651
1652 /*
1653 * in order to insert checksums into the metadata in large chunks,
1654 * we wait until bio submission time. All the pages in the bio are
1655 * checksummed and sums are attached onto the ordered extent record.
1656 *
1657 * At IO completion time the cums attached on the ordered extent record
1658 * are inserted into the btree
1659 */
1660 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1661 struct bio *bio, int mirror_num,
1662 unsigned long bio_flags,
1663 u64 bio_offset)
1664 {
1665 struct btrfs_root *root = BTRFS_I(inode)->root;
1666 int ret = 0;
1667
1668 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1669 BUG_ON(ret); /* -ENOMEM */
1670 return 0;
1671 }
1672
1673 /*
1674 * in order to insert checksums into the metadata in large chunks,
1675 * we wait until bio submission time. All the pages in the bio are
1676 * checksummed and sums are attached onto the ordered extent record.
1677 *
1678 * At IO completion time the cums attached on the ordered extent record
1679 * are inserted into the btree
1680 */
1681 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1682 int mirror_num, unsigned long bio_flags,
1683 u64 bio_offset)
1684 {
1685 struct btrfs_root *root = BTRFS_I(inode)->root;
1686 int ret;
1687
1688 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
1689 if (ret)
1690 bio_endio(bio, ret);
1691 return ret;
1692 }
1693
1694 /*
1695 * extent_io.c submission hook. This does the right thing for csum calculation
1696 * on write, or reading the csums from the tree before a read
1697 */
1698 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1699 int mirror_num, unsigned long bio_flags,
1700 u64 bio_offset)
1701 {
1702 struct btrfs_root *root = BTRFS_I(inode)->root;
1703 int ret = 0;
1704 int skip_sum;
1705 int metadata = 0;
1706 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1707
1708 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1709
1710 if (btrfs_is_free_space_inode(inode))
1711 metadata = 2;
1712
1713 if (!(rw & REQ_WRITE)) {
1714 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1715 if (ret)
1716 goto out;
1717
1718 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1719 ret = btrfs_submit_compressed_read(inode, bio,
1720 mirror_num,
1721 bio_flags);
1722 goto out;
1723 } else if (!skip_sum) {
1724 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1725 if (ret)
1726 goto out;
1727 }
1728 goto mapit;
1729 } else if (async && !skip_sum) {
1730 /* csum items have already been cloned */
1731 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1732 goto mapit;
1733 /* we're doing a write, do the async checksumming */
1734 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1735 inode, rw, bio, mirror_num,
1736 bio_flags, bio_offset,
1737 __btrfs_submit_bio_start,
1738 __btrfs_submit_bio_done);
1739 goto out;
1740 } else if (!skip_sum) {
1741 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1742 if (ret)
1743 goto out;
1744 }
1745
1746 mapit:
1747 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
1748
1749 out:
1750 if (ret < 0)
1751 bio_endio(bio, ret);
1752 return ret;
1753 }
1754
1755 /*
1756 * given a list of ordered sums record them in the inode. This happens
1757 * at IO completion time based on sums calculated at bio submission time.
1758 */
1759 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1760 struct inode *inode, u64 file_offset,
1761 struct list_head *list)
1762 {
1763 struct btrfs_ordered_sum *sum;
1764
1765 list_for_each_entry(sum, list, list) {
1766 trans->adding_csums = 1;
1767 btrfs_csum_file_blocks(trans,
1768 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1769 trans->adding_csums = 0;
1770 }
1771 return 0;
1772 }
1773
1774 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1775 struct extent_state **cached_state)
1776 {
1777 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0);
1778 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1779 cached_state, GFP_NOFS);
1780 }
1781
1782 /* see btrfs_writepage_start_hook for details on why this is required */
1783 struct btrfs_writepage_fixup {
1784 struct page *page;
1785 struct btrfs_work work;
1786 };
1787
1788 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1789 {
1790 struct btrfs_writepage_fixup *fixup;
1791 struct btrfs_ordered_extent *ordered;
1792 struct extent_state *cached_state = NULL;
1793 struct page *page;
1794 struct inode *inode;
1795 u64 page_start;
1796 u64 page_end;
1797 int ret;
1798
1799 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1800 page = fixup->page;
1801 again:
1802 lock_page(page);
1803 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1804 ClearPageChecked(page);
1805 goto out_page;
1806 }
1807
1808 inode = page->mapping->host;
1809 page_start = page_offset(page);
1810 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1811
1812 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
1813 &cached_state);
1814
1815 /* already ordered? We're done */
1816 if (PagePrivate2(page))
1817 goto out;
1818
1819 ordered = btrfs_lookup_ordered_extent(inode, page_start);
1820 if (ordered) {
1821 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
1822 page_end, &cached_state, GFP_NOFS);
1823 unlock_page(page);
1824 btrfs_start_ordered_extent(inode, ordered, 1);
1825 btrfs_put_ordered_extent(ordered);
1826 goto again;
1827 }
1828
1829 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
1830 if (ret) {
1831 mapping_set_error(page->mapping, ret);
1832 end_extent_writepage(page, ret, page_start, page_end);
1833 ClearPageChecked(page);
1834 goto out;
1835 }
1836
1837 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
1838 ClearPageChecked(page);
1839 set_page_dirty(page);
1840 out:
1841 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
1842 &cached_state, GFP_NOFS);
1843 out_page:
1844 unlock_page(page);
1845 page_cache_release(page);
1846 kfree(fixup);
1847 }
1848
1849 /*
1850 * There are a few paths in the higher layers of the kernel that directly
1851 * set the page dirty bit without asking the filesystem if it is a
1852 * good idea. This causes problems because we want to make sure COW
1853 * properly happens and the data=ordered rules are followed.
1854 *
1855 * In our case any range that doesn't have the ORDERED bit set
1856 * hasn't been properly setup for IO. We kick off an async process
1857 * to fix it up. The async helper will wait for ordered extents, set
1858 * the delalloc bit and make it safe to write the page.
1859 */
1860 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
1861 {
1862 struct inode *inode = page->mapping->host;
1863 struct btrfs_writepage_fixup *fixup;
1864 struct btrfs_root *root = BTRFS_I(inode)->root;
1865
1866 /* this page is properly in the ordered list */
1867 if (TestClearPagePrivate2(page))
1868 return 0;
1869
1870 if (PageChecked(page))
1871 return -EAGAIN;
1872
1873 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
1874 if (!fixup)
1875 return -EAGAIN;
1876
1877 SetPageChecked(page);
1878 page_cache_get(page);
1879 fixup->work.func = btrfs_writepage_fixup_worker;
1880 fixup->page = page;
1881 btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
1882 return -EBUSY;
1883 }
1884
1885 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
1886 struct inode *inode, u64 file_pos,
1887 u64 disk_bytenr, u64 disk_num_bytes,
1888 u64 num_bytes, u64 ram_bytes,
1889 u8 compression, u8 encryption,
1890 u16 other_encoding, int extent_type)
1891 {
1892 struct btrfs_root *root = BTRFS_I(inode)->root;
1893 struct btrfs_file_extent_item *fi;
1894 struct btrfs_path *path;
1895 struct extent_buffer *leaf;
1896 struct btrfs_key ins;
1897 int ret;
1898
1899 path = btrfs_alloc_path();
1900 if (!path)
1901 return -ENOMEM;
1902
1903 path->leave_spinning = 1;
1904
1905 /*
1906 * we may be replacing one extent in the tree with another.
1907 * The new extent is pinned in the extent map, and we don't want
1908 * to drop it from the cache until it is completely in the btree.
1909 *
1910 * So, tell btrfs_drop_extents to leave this extent in the cache.
1911 * the caller is expected to unpin it and allow it to be merged
1912 * with the others.
1913 */
1914 ret = btrfs_drop_extents(trans, root, inode, file_pos,
1915 file_pos + num_bytes, 0);
1916 if (ret)
1917 goto out;
1918
1919 ins.objectid = btrfs_ino(inode);
1920 ins.offset = file_pos;
1921 ins.type = BTRFS_EXTENT_DATA_KEY;
1922 ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi));
1923 if (ret)
1924 goto out;
1925 leaf = path->nodes[0];
1926 fi = btrfs_item_ptr(leaf, path->slots[0],
1927 struct btrfs_file_extent_item);
1928 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1929 btrfs_set_file_extent_type(leaf, fi, extent_type);
1930 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
1931 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
1932 btrfs_set_file_extent_offset(leaf, fi, 0);
1933 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
1934 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
1935 btrfs_set_file_extent_compression(leaf, fi, compression);
1936 btrfs_set_file_extent_encryption(leaf, fi, encryption);
1937 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
1938
1939 btrfs_mark_buffer_dirty(leaf);
1940 btrfs_release_path(path);
1941
1942 inode_add_bytes(inode, num_bytes);
1943
1944 ins.objectid = disk_bytenr;
1945 ins.offset = disk_num_bytes;
1946 ins.type = BTRFS_EXTENT_ITEM_KEY;
1947 ret = btrfs_alloc_reserved_file_extent(trans, root,
1948 root->root_key.objectid,
1949 btrfs_ino(inode), file_pos, &ins);
1950 out:
1951 btrfs_free_path(path);
1952
1953 return ret;
1954 }
1955
1956 /* snapshot-aware defrag */
1957 struct sa_defrag_extent_backref {
1958 struct rb_node node;
1959 struct old_sa_defrag_extent *old;
1960 u64 root_id;
1961 u64 inum;
1962 u64 file_pos;
1963 u64 extent_offset;
1964 u64 num_bytes;
1965 u64 generation;
1966 };
1967
1968 struct old_sa_defrag_extent {
1969 struct list_head list;
1970 struct new_sa_defrag_extent *new;
1971
1972 u64 extent_offset;
1973 u64 bytenr;
1974 u64 offset;
1975 u64 len;
1976 int count;
1977 };
1978
1979 struct new_sa_defrag_extent {
1980 struct rb_root root;
1981 struct list_head head;
1982 struct btrfs_path *path;
1983 struct inode *inode;
1984 u64 file_pos;
1985 u64 len;
1986 u64 bytenr;
1987 u64 disk_len;
1988 u8 compress_type;
1989 };
1990
1991 static int backref_comp(struct sa_defrag_extent_backref *b1,
1992 struct sa_defrag_extent_backref *b2)
1993 {
1994 if (b1->root_id < b2->root_id)
1995 return -1;
1996 else if (b1->root_id > b2->root_id)
1997 return 1;
1998
1999 if (b1->inum < b2->inum)
2000 return -1;
2001 else if (b1->inum > b2->inum)
2002 return 1;
2003
2004 if (b1->file_pos < b2->file_pos)
2005 return -1;
2006 else if (b1->file_pos > b2->file_pos)
2007 return 1;
2008
2009 /*
2010 * [------------------------------] ===> (a range of space)
2011 * |<--->| |<---->| =============> (fs/file tree A)
2012 * |<---------------------------->| ===> (fs/file tree B)
2013 *
2014 * A range of space can refer to two file extents in one tree while
2015 * refer to only one file extent in another tree.
2016 *
2017 * So we may process a disk offset more than one time(two extents in A)
2018 * and locate at the same extent(one extent in B), then insert two same
2019 * backrefs(both refer to the extent in B).
2020 */
2021 return 0;
2022 }
2023
2024 static void backref_insert(struct rb_root *root,
2025 struct sa_defrag_extent_backref *backref)
2026 {
2027 struct rb_node **p = &root->rb_node;
2028 struct rb_node *parent = NULL;
2029 struct sa_defrag_extent_backref *entry;
2030 int ret;
2031
2032 while (*p) {
2033 parent = *p;
2034 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2035
2036 ret = backref_comp(backref, entry);
2037 if (ret < 0)
2038 p = &(*p)->rb_left;
2039 else
2040 p = &(*p)->rb_right;
2041 }
2042
2043 rb_link_node(&backref->node, parent, p);
2044 rb_insert_color(&backref->node, root);
2045 }
2046
2047 /*
2048 * Note the backref might has changed, and in this case we just return 0.
2049 */
2050 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2051 void *ctx)
2052 {
2053 struct btrfs_file_extent_item *extent;
2054 struct btrfs_fs_info *fs_info;
2055 struct old_sa_defrag_extent *old = ctx;
2056 struct new_sa_defrag_extent *new = old->new;
2057 struct btrfs_path *path = new->path;
2058 struct btrfs_key key;
2059 struct btrfs_root *root;
2060 struct sa_defrag_extent_backref *backref;
2061 struct extent_buffer *leaf;
2062 struct inode *inode = new->inode;
2063 int slot;
2064 int ret;
2065 u64 extent_offset;
2066 u64 num_bytes;
2067
2068 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2069 inum == btrfs_ino(inode))
2070 return 0;
2071
2072 key.objectid = root_id;
2073 key.type = BTRFS_ROOT_ITEM_KEY;
2074 key.offset = (u64)-1;
2075
2076 fs_info = BTRFS_I(inode)->root->fs_info;
2077 root = btrfs_read_fs_root_no_name(fs_info, &key);
2078 if (IS_ERR(root)) {
2079 if (PTR_ERR(root) == -ENOENT)
2080 return 0;
2081 WARN_ON(1);
2082 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
2083 inum, offset, root_id);
2084 return PTR_ERR(root);
2085 }
2086
2087 key.objectid = inum;
2088 key.type = BTRFS_EXTENT_DATA_KEY;
2089 if (offset > (u64)-1 << 32)
2090 key.offset = 0;
2091 else
2092 key.offset = offset;
2093
2094 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2095 if (ret < 0) {
2096 WARN_ON(1);
2097 return ret;
2098 }
2099
2100 while (1) {
2101 cond_resched();
2102
2103 leaf = path->nodes[0];
2104 slot = path->slots[0];
2105
2106 if (slot >= btrfs_header_nritems(leaf)) {
2107 ret = btrfs_next_leaf(root, path);
2108 if (ret < 0) {
2109 goto out;
2110 } else if (ret > 0) {
2111 ret = 0;
2112 goto out;
2113 }
2114 continue;
2115 }
2116
2117 path->slots[0]++;
2118
2119 btrfs_item_key_to_cpu(leaf, &key, slot);
2120
2121 if (key.objectid > inum)
2122 goto out;
2123
2124 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2125 continue;
2126
2127 extent = btrfs_item_ptr(leaf, slot,
2128 struct btrfs_file_extent_item);
2129
2130 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2131 continue;
2132
2133 extent_offset = btrfs_file_extent_offset(leaf, extent);
2134 if (key.offset - extent_offset != offset)
2135 continue;
2136
2137 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2138 if (extent_offset >= old->extent_offset + old->offset +
2139 old->len || extent_offset + num_bytes <=
2140 old->extent_offset + old->offset)
2141 continue;
2142
2143 break;
2144 }
2145
2146 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2147 if (!backref) {
2148 ret = -ENOENT;
2149 goto out;
2150 }
2151
2152 backref->root_id = root_id;
2153 backref->inum = inum;
2154 backref->file_pos = offset + extent_offset;
2155 backref->num_bytes = num_bytes;
2156 backref->extent_offset = extent_offset;
2157 backref->generation = btrfs_file_extent_generation(leaf, extent);
2158 backref->old = old;
2159 backref_insert(&new->root, backref);
2160 old->count++;
2161 out:
2162 btrfs_release_path(path);
2163 WARN_ON(ret);
2164 return ret;
2165 }
2166
2167 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2168 struct new_sa_defrag_extent *new)
2169 {
2170 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
2171 struct old_sa_defrag_extent *old, *tmp;
2172 int ret;
2173
2174 new->path = path;
2175
2176 list_for_each_entry_safe(old, tmp, &new->head, list) {
2177 ret = iterate_inodes_from_logical(old->bytenr, fs_info,
2178 path, record_one_backref,
2179 old);
2180 BUG_ON(ret < 0 && ret != -ENOENT);
2181
2182 /* no backref to be processed for this extent */
2183 if (!old->count) {
2184 list_del(&old->list);
2185 kfree(old);
2186 }
2187 }
2188
2189 if (list_empty(&new->head))
2190 return false;
2191
2192 return true;
2193 }
2194
2195 static int relink_is_mergable(struct extent_buffer *leaf,
2196 struct btrfs_file_extent_item *fi,
2197 u64 disk_bytenr)
2198 {
2199 if (btrfs_file_extent_disk_bytenr(leaf, fi) != disk_bytenr)
2200 return 0;
2201
2202 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2203 return 0;
2204
2205 if (btrfs_file_extent_compression(leaf, fi) ||
2206 btrfs_file_extent_encryption(leaf, fi) ||
2207 btrfs_file_extent_other_encoding(leaf, fi))
2208 return 0;
2209
2210 return 1;
2211 }
2212
2213 /*
2214 * Note the backref might has changed, and in this case we just return 0.
2215 */
2216 static noinline int relink_extent_backref(struct btrfs_path *path,
2217 struct sa_defrag_extent_backref *prev,
2218 struct sa_defrag_extent_backref *backref)
2219 {
2220 struct btrfs_file_extent_item *extent;
2221 struct btrfs_file_extent_item *item;
2222 struct btrfs_ordered_extent *ordered;
2223 struct btrfs_trans_handle *trans;
2224 struct btrfs_fs_info *fs_info;
2225 struct btrfs_root *root;
2226 struct btrfs_key key;
2227 struct extent_buffer *leaf;
2228 struct old_sa_defrag_extent *old = backref->old;
2229 struct new_sa_defrag_extent *new = old->new;
2230 struct inode *src_inode = new->inode;
2231 struct inode *inode;
2232 struct extent_state *cached = NULL;
2233 int ret = 0;
2234 u64 start;
2235 u64 len;
2236 u64 lock_start;
2237 u64 lock_end;
2238 bool merge = false;
2239 int index;
2240
2241 if (prev && prev->root_id == backref->root_id &&
2242 prev->inum == backref->inum &&
2243 prev->file_pos + prev->num_bytes == backref->file_pos)
2244 merge = true;
2245
2246 /* step 1: get root */
2247 key.objectid = backref->root_id;
2248 key.type = BTRFS_ROOT_ITEM_KEY;
2249 key.offset = (u64)-1;
2250
2251 fs_info = BTRFS_I(src_inode)->root->fs_info;
2252 index = srcu_read_lock(&fs_info->subvol_srcu);
2253
2254 root = btrfs_read_fs_root_no_name(fs_info, &key);
2255 if (IS_ERR(root)) {
2256 srcu_read_unlock(&fs_info->subvol_srcu, index);
2257 if (PTR_ERR(root) == -ENOENT)
2258 return 0;
2259 return PTR_ERR(root);
2260 }
2261 if (btrfs_root_refs(&root->root_item) == 0) {
2262 srcu_read_unlock(&fs_info->subvol_srcu, index);
2263 /* parse ENOENT to 0 */
2264 return 0;
2265 }
2266
2267 /* step 2: get inode */
2268 key.objectid = backref->inum;
2269 key.type = BTRFS_INODE_ITEM_KEY;
2270 key.offset = 0;
2271
2272 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2273 if (IS_ERR(inode)) {
2274 srcu_read_unlock(&fs_info->subvol_srcu, index);
2275 return 0;
2276 }
2277
2278 srcu_read_unlock(&fs_info->subvol_srcu, index);
2279
2280 /* step 3: relink backref */
2281 lock_start = backref->file_pos;
2282 lock_end = backref->file_pos + backref->num_bytes - 1;
2283 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2284 0, &cached);
2285
2286 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2287 if (ordered) {
2288 btrfs_put_ordered_extent(ordered);
2289 goto out_unlock;
2290 }
2291
2292 trans = btrfs_join_transaction(root);
2293 if (IS_ERR(trans)) {
2294 ret = PTR_ERR(trans);
2295 goto out_unlock;
2296 }
2297
2298 key.objectid = backref->inum;
2299 key.type = BTRFS_EXTENT_DATA_KEY;
2300 key.offset = backref->file_pos;
2301
2302 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2303 if (ret < 0) {
2304 goto out_free_path;
2305 } else if (ret > 0) {
2306 ret = 0;
2307 goto out_free_path;
2308 }
2309
2310 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2311 struct btrfs_file_extent_item);
2312
2313 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2314 backref->generation)
2315 goto out_free_path;
2316
2317 btrfs_release_path(path);
2318
2319 start = backref->file_pos;
2320 if (backref->extent_offset < old->extent_offset + old->offset)
2321 start += old->extent_offset + old->offset -
2322 backref->extent_offset;
2323
2324 len = min(backref->extent_offset + backref->num_bytes,
2325 old->extent_offset + old->offset + old->len);
2326 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2327
2328 ret = btrfs_drop_extents(trans, root, inode, start,
2329 start + len, 1);
2330 if (ret)
2331 goto out_free_path;
2332 again:
2333 key.objectid = btrfs_ino(inode);
2334 key.type = BTRFS_EXTENT_DATA_KEY;
2335 key.offset = start;
2336
2337 path->leave_spinning = 1;
2338 if (merge) {
2339 struct btrfs_file_extent_item *fi;
2340 u64 extent_len;
2341 struct btrfs_key found_key;
2342
2343 ret = btrfs_search_slot(trans, root, &key, path, 1, 1);
2344 if (ret < 0)
2345 goto out_free_path;
2346
2347 path->slots[0]--;
2348 leaf = path->nodes[0];
2349 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2350
2351 fi = btrfs_item_ptr(leaf, path->slots[0],
2352 struct btrfs_file_extent_item);
2353 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2354
2355 if (relink_is_mergable(leaf, fi, new->bytenr) &&
2356 extent_len + found_key.offset == start) {
2357 btrfs_set_file_extent_num_bytes(leaf, fi,
2358 extent_len + len);
2359 btrfs_mark_buffer_dirty(leaf);
2360 inode_add_bytes(inode, len);
2361
2362 ret = 1;
2363 goto out_free_path;
2364 } else {
2365 merge = false;
2366 btrfs_release_path(path);
2367 goto again;
2368 }
2369 }
2370
2371 ret = btrfs_insert_empty_item(trans, root, path, &key,
2372 sizeof(*extent));
2373 if (ret) {
2374 btrfs_abort_transaction(trans, root, ret);
2375 goto out_free_path;
2376 }
2377
2378 leaf = path->nodes[0];
2379 item = btrfs_item_ptr(leaf, path->slots[0],
2380 struct btrfs_file_extent_item);
2381 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2382 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2383 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2384 btrfs_set_file_extent_num_bytes(leaf, item, len);
2385 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2386 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2387 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2388 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2389 btrfs_set_file_extent_encryption(leaf, item, 0);
2390 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2391
2392 btrfs_mark_buffer_dirty(leaf);
2393 inode_add_bytes(inode, len);
2394 btrfs_release_path(path);
2395
2396 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2397 new->disk_len, 0,
2398 backref->root_id, backref->inum,
2399 new->file_pos, 0); /* start - extent_offset */
2400 if (ret) {
2401 btrfs_abort_transaction(trans, root, ret);
2402 goto out_free_path;
2403 }
2404
2405 ret = 1;
2406 out_free_path:
2407 btrfs_release_path(path);
2408 path->leave_spinning = 0;
2409 btrfs_end_transaction(trans, root);
2410 out_unlock:
2411 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2412 &cached, GFP_NOFS);
2413 iput(inode);
2414 return ret;
2415 }
2416
2417 static void relink_file_extents(struct new_sa_defrag_extent *new)
2418 {
2419 struct btrfs_path *path;
2420 struct old_sa_defrag_extent *old, *tmp;
2421 struct sa_defrag_extent_backref *backref;
2422 struct sa_defrag_extent_backref *prev = NULL;
2423 struct inode *inode;
2424 struct btrfs_root *root;
2425 struct rb_node *node;
2426 int ret;
2427
2428 inode = new->inode;
2429 root = BTRFS_I(inode)->root;
2430
2431 path = btrfs_alloc_path();
2432 if (!path)
2433 return;
2434
2435 if (!record_extent_backrefs(path, new)) {
2436 btrfs_free_path(path);
2437 goto out;
2438 }
2439 btrfs_release_path(path);
2440
2441 while (1) {
2442 node = rb_first(&new->root);
2443 if (!node)
2444 break;
2445 rb_erase(node, &new->root);
2446
2447 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2448
2449 ret = relink_extent_backref(path, prev, backref);
2450 WARN_ON(ret < 0);
2451
2452 kfree(prev);
2453
2454 if (ret == 1)
2455 prev = backref;
2456 else
2457 prev = NULL;
2458 cond_resched();
2459 }
2460 kfree(prev);
2461
2462 btrfs_free_path(path);
2463
2464 list_for_each_entry_safe(old, tmp, &new->head, list) {
2465 list_del(&old->list);
2466 kfree(old);
2467 }
2468 out:
2469 atomic_dec(&root->fs_info->defrag_running);
2470 wake_up(&root->fs_info->transaction_wait);
2471
2472 kfree(new);
2473 }
2474
2475 static struct new_sa_defrag_extent *
2476 record_old_file_extents(struct inode *inode,
2477 struct btrfs_ordered_extent *ordered)
2478 {
2479 struct btrfs_root *root = BTRFS_I(inode)->root;
2480 struct btrfs_path *path;
2481 struct btrfs_key key;
2482 struct old_sa_defrag_extent *old, *tmp;
2483 struct new_sa_defrag_extent *new;
2484 int ret;
2485
2486 new = kmalloc(sizeof(*new), GFP_NOFS);
2487 if (!new)
2488 return NULL;
2489
2490 new->inode = inode;
2491 new->file_pos = ordered->file_offset;
2492 new->len = ordered->len;
2493 new->bytenr = ordered->start;
2494 new->disk_len = ordered->disk_len;
2495 new->compress_type = ordered->compress_type;
2496 new->root = RB_ROOT;
2497 INIT_LIST_HEAD(&new->head);
2498
2499 path = btrfs_alloc_path();
2500 if (!path)
2501 goto out_kfree;
2502
2503 key.objectid = btrfs_ino(inode);
2504 key.type = BTRFS_EXTENT_DATA_KEY;
2505 key.offset = new->file_pos;
2506
2507 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2508 if (ret < 0)
2509 goto out_free_path;
2510 if (ret > 0 && path->slots[0] > 0)
2511 path->slots[0]--;
2512
2513 /* find out all the old extents for the file range */
2514 while (1) {
2515 struct btrfs_file_extent_item *extent;
2516 struct extent_buffer *l;
2517 int slot;
2518 u64 num_bytes;
2519 u64 offset;
2520 u64 end;
2521 u64 disk_bytenr;
2522 u64 extent_offset;
2523
2524 l = path->nodes[0];
2525 slot = path->slots[0];
2526
2527 if (slot >= btrfs_header_nritems(l)) {
2528 ret = btrfs_next_leaf(root, path);
2529 if (ret < 0)
2530 goto out_free_list;
2531 else if (ret > 0)
2532 break;
2533 continue;
2534 }
2535
2536 btrfs_item_key_to_cpu(l, &key, slot);
2537
2538 if (key.objectid != btrfs_ino(inode))
2539 break;
2540 if (key.type != BTRFS_EXTENT_DATA_KEY)
2541 break;
2542 if (key.offset >= new->file_pos + new->len)
2543 break;
2544
2545 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2546
2547 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2548 if (key.offset + num_bytes < new->file_pos)
2549 goto next;
2550
2551 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2552 if (!disk_bytenr)
2553 goto next;
2554
2555 extent_offset = btrfs_file_extent_offset(l, extent);
2556
2557 old = kmalloc(sizeof(*old), GFP_NOFS);
2558 if (!old)
2559 goto out_free_list;
2560
2561 offset = max(new->file_pos, key.offset);
2562 end = min(new->file_pos + new->len, key.offset + num_bytes);
2563
2564 old->bytenr = disk_bytenr;
2565 old->extent_offset = extent_offset;
2566 old->offset = offset - key.offset;
2567 old->len = end - offset;
2568 old->new = new;
2569 old->count = 0;
2570 list_add_tail(&old->list, &new->head);
2571 next:
2572 path->slots[0]++;
2573 cond_resched();
2574 }
2575
2576 btrfs_free_path(path);
2577 atomic_inc(&root->fs_info->defrag_running);
2578
2579 return new;
2580
2581 out_free_list:
2582 list_for_each_entry_safe(old, tmp, &new->head, list) {
2583 list_del(&old->list);
2584 kfree(old);
2585 }
2586 out_free_path:
2587 btrfs_free_path(path);
2588 out_kfree:
2589 kfree(new);
2590 return NULL;
2591 }
2592
2593 /*
2594 * helper function for btrfs_finish_ordered_io, this
2595 * just reads in some of the csum leaves to prime them into ram
2596 * before we start the transaction. It limits the amount of btree
2597 * reads required while inside the transaction.
2598 */
2599 /* as ordered data IO finishes, this gets called so we can finish
2600 * an ordered extent if the range of bytes in the file it covers are
2601 * fully written.
2602 */
2603 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2604 {
2605 struct inode *inode = ordered_extent->inode;
2606 struct btrfs_root *root = BTRFS_I(inode)->root;
2607 struct btrfs_trans_handle *trans = NULL;
2608 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2609 struct extent_state *cached_state = NULL;
2610 struct new_sa_defrag_extent *new = NULL;
2611 int compress_type = 0;
2612 int ret;
2613 bool nolock;
2614
2615 nolock = btrfs_is_free_space_inode(inode);
2616
2617 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2618 ret = -EIO;
2619 goto out;
2620 }
2621
2622 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2623 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2624 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2625 if (nolock)
2626 trans = btrfs_join_transaction_nolock(root);
2627 else
2628 trans = btrfs_join_transaction(root);
2629 if (IS_ERR(trans)) {
2630 ret = PTR_ERR(trans);
2631 trans = NULL;
2632 goto out;
2633 }
2634 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2635 ret = btrfs_update_inode_fallback(trans, root, inode);
2636 if (ret) /* -ENOMEM or corruption */
2637 btrfs_abort_transaction(trans, root, ret);
2638 goto out;
2639 }
2640
2641 lock_extent_bits(io_tree, ordered_extent->file_offset,
2642 ordered_extent->file_offset + ordered_extent->len - 1,
2643 0, &cached_state);
2644
2645 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2646 ordered_extent->file_offset + ordered_extent->len - 1,
2647 EXTENT_DEFRAG, 1, cached_state);
2648 if (ret) {
2649 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2650 if (last_snapshot >= BTRFS_I(inode)->generation)
2651 /* the inode is shared */
2652 new = record_old_file_extents(inode, ordered_extent);
2653
2654 clear_extent_bit(io_tree, ordered_extent->file_offset,
2655 ordered_extent->file_offset + ordered_extent->len - 1,
2656 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2657 }
2658
2659 if (nolock)
2660 trans = btrfs_join_transaction_nolock(root);
2661 else
2662 trans = btrfs_join_transaction(root);
2663 if (IS_ERR(trans)) {
2664 ret = PTR_ERR(trans);
2665 trans = NULL;
2666 goto out_unlock;
2667 }
2668 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2669
2670 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2671 compress_type = ordered_extent->compress_type;
2672 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2673 BUG_ON(compress_type);
2674 ret = btrfs_mark_extent_written(trans, inode,
2675 ordered_extent->file_offset,
2676 ordered_extent->file_offset +
2677 ordered_extent->len);
2678 } else {
2679 BUG_ON(root == root->fs_info->tree_root);
2680 ret = insert_reserved_file_extent(trans, inode,
2681 ordered_extent->file_offset,
2682 ordered_extent->start,
2683 ordered_extent->disk_len,
2684 ordered_extent->len,
2685 ordered_extent->len,
2686 compress_type, 0, 0,
2687 BTRFS_FILE_EXTENT_REG);
2688 }
2689 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2690 ordered_extent->file_offset, ordered_extent->len,
2691 trans->transid);
2692 if (ret < 0) {
2693 btrfs_abort_transaction(trans, root, ret);
2694 goto out_unlock;
2695 }
2696
2697 add_pending_csums(trans, inode, ordered_extent->file_offset,
2698 &ordered_extent->list);
2699
2700 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2701 ret = btrfs_update_inode_fallback(trans, root, inode);
2702 if (ret) { /* -ENOMEM or corruption */
2703 btrfs_abort_transaction(trans, root, ret);
2704 goto out_unlock;
2705 }
2706 ret = 0;
2707 out_unlock:
2708 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2709 ordered_extent->file_offset +
2710 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2711 out:
2712 if (root != root->fs_info->tree_root)
2713 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2714 if (trans)
2715 btrfs_end_transaction(trans, root);
2716
2717 if (ret) {
2718 clear_extent_uptodate(io_tree, ordered_extent->file_offset,
2719 ordered_extent->file_offset +
2720 ordered_extent->len - 1, NULL, GFP_NOFS);
2721
2722 /*
2723 * If the ordered extent had an IOERR or something else went
2724 * wrong we need to return the space for this ordered extent
2725 * back to the allocator.
2726 */
2727 if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2728 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
2729 btrfs_free_reserved_extent(root, ordered_extent->start,
2730 ordered_extent->disk_len);
2731 }
2732
2733
2734 /*
2735 * This needs to be done to make sure anybody waiting knows we are done
2736 * updating everything for this ordered extent.
2737 */
2738 btrfs_remove_ordered_extent(inode, ordered_extent);
2739
2740 /* for snapshot-aware defrag */
2741 if (new)
2742 relink_file_extents(new);
2743
2744 /* once for us */
2745 btrfs_put_ordered_extent(ordered_extent);
2746 /* once for the tree */
2747 btrfs_put_ordered_extent(ordered_extent);
2748
2749 return ret;
2750 }
2751
2752 static void finish_ordered_fn(struct btrfs_work *work)
2753 {
2754 struct btrfs_ordered_extent *ordered_extent;
2755 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
2756 btrfs_finish_ordered_io(ordered_extent);
2757 }
2758
2759 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
2760 struct extent_state *state, int uptodate)
2761 {
2762 struct inode *inode = page->mapping->host;
2763 struct btrfs_root *root = BTRFS_I(inode)->root;
2764 struct btrfs_ordered_extent *ordered_extent = NULL;
2765 struct btrfs_workers *workers;
2766
2767 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
2768
2769 ClearPagePrivate2(page);
2770 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
2771 end - start + 1, uptodate))
2772 return 0;
2773
2774 ordered_extent->work.func = finish_ordered_fn;
2775 ordered_extent->work.flags = 0;
2776
2777 if (btrfs_is_free_space_inode(inode))
2778 workers = &root->fs_info->endio_freespace_worker;
2779 else
2780 workers = &root->fs_info->endio_write_workers;
2781 btrfs_queue_worker(workers, &ordered_extent->work);
2782
2783 return 0;
2784 }
2785
2786 /*
2787 * when reads are done, we need to check csums to verify the data is correct
2788 * if there's a match, we allow the bio to finish. If not, the code in
2789 * extent_io.c will try to find good copies for us.
2790 */
2791 static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
2792 struct extent_state *state, int mirror)
2793 {
2794 size_t offset = start - page_offset(page);
2795 struct inode *inode = page->mapping->host;
2796 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2797 char *kaddr;
2798 u64 private = ~(u32)0;
2799 int ret;
2800 struct btrfs_root *root = BTRFS_I(inode)->root;
2801 u32 csum = ~(u32)0;
2802 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
2803 DEFAULT_RATELIMIT_BURST);
2804
2805 if (PageChecked(page)) {
2806 ClearPageChecked(page);
2807 goto good;
2808 }
2809
2810 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
2811 goto good;
2812
2813 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
2814 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
2815 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
2816 GFP_NOFS);
2817 return 0;
2818 }
2819
2820 if (state && state->start == start) {
2821 private = state->private;
2822 ret = 0;
2823 } else {
2824 ret = get_state_private(io_tree, start, &private);
2825 }
2826 kaddr = kmap_atomic(page);
2827 if (ret)
2828 goto zeroit;
2829
2830 csum = btrfs_csum_data(kaddr + offset, csum, end - start + 1);
2831 btrfs_csum_final(csum, (char *)&csum);
2832 if (csum != private)
2833 goto zeroit;
2834
2835 kunmap_atomic(kaddr);
2836 good:
2837 return 0;
2838
2839 zeroit:
2840 if (__ratelimit(&_rs))
2841 btrfs_info(root->fs_info, "csum failed ino %llu off %llu csum %u private %llu",
2842 (unsigned long long)btrfs_ino(page->mapping->host),
2843 (unsigned long long)start, csum,
2844 (unsigned long long)private);
2845 memset(kaddr + offset, 1, end - start + 1);
2846 flush_dcache_page(page);
2847 kunmap_atomic(kaddr);
2848 if (private == 0)
2849 return 0;
2850 return -EIO;
2851 }
2852
2853 struct delayed_iput {
2854 struct list_head list;
2855 struct inode *inode;
2856 };
2857
2858 /* JDM: If this is fs-wide, why can't we add a pointer to
2859 * btrfs_inode instead and avoid the allocation? */
2860 void btrfs_add_delayed_iput(struct inode *inode)
2861 {
2862 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2863 struct delayed_iput *delayed;
2864
2865 if (atomic_add_unless(&inode->i_count, -1, 1))
2866 return;
2867
2868 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
2869 delayed->inode = inode;
2870
2871 spin_lock(&fs_info->delayed_iput_lock);
2872 list_add_tail(&delayed->list, &fs_info->delayed_iputs);
2873 spin_unlock(&fs_info->delayed_iput_lock);
2874 }
2875
2876 void btrfs_run_delayed_iputs(struct btrfs_root *root)
2877 {
2878 LIST_HEAD(list);
2879 struct btrfs_fs_info *fs_info = root->fs_info;
2880 struct delayed_iput *delayed;
2881 int empty;
2882
2883 spin_lock(&fs_info->delayed_iput_lock);
2884 empty = list_empty(&fs_info->delayed_iputs);
2885 spin_unlock(&fs_info->delayed_iput_lock);
2886 if (empty)
2887 return;
2888
2889 spin_lock(&fs_info->delayed_iput_lock);
2890 list_splice_init(&fs_info->delayed_iputs, &list);
2891 spin_unlock(&fs_info->delayed_iput_lock);
2892
2893 while (!list_empty(&list)) {
2894 delayed = list_entry(list.next, struct delayed_iput, list);
2895 list_del(&delayed->list);
2896 iput(delayed->inode);
2897 kfree(delayed);
2898 }
2899 }
2900
2901 /*
2902 * This is called in transaction commit time. If there are no orphan
2903 * files in the subvolume, it removes orphan item and frees block_rsv
2904 * structure.
2905 */
2906 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
2907 struct btrfs_root *root)
2908 {
2909 struct btrfs_block_rsv *block_rsv;
2910 int ret;
2911
2912 if (atomic_read(&root->orphan_inodes) ||
2913 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
2914 return;
2915
2916 spin_lock(&root->orphan_lock);
2917 if (atomic_read(&root->orphan_inodes)) {
2918 spin_unlock(&root->orphan_lock);
2919 return;
2920 }
2921
2922 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
2923 spin_unlock(&root->orphan_lock);
2924 return;
2925 }
2926
2927 block_rsv = root->orphan_block_rsv;
2928 root->orphan_block_rsv = NULL;
2929 spin_unlock(&root->orphan_lock);
2930
2931 if (root->orphan_item_inserted &&
2932 btrfs_root_refs(&root->root_item) > 0) {
2933 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
2934 root->root_key.objectid);
2935 BUG_ON(ret);
2936 root->orphan_item_inserted = 0;
2937 }
2938
2939 if (block_rsv) {
2940 WARN_ON(block_rsv->size > 0);
2941 btrfs_free_block_rsv(root, block_rsv);
2942 }
2943 }
2944
2945 /*
2946 * This creates an orphan entry for the given inode in case something goes
2947 * wrong in the middle of an unlink/truncate.
2948 *
2949 * NOTE: caller of this function should reserve 5 units of metadata for
2950 * this function.
2951 */
2952 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
2953 {
2954 struct btrfs_root *root = BTRFS_I(inode)->root;
2955 struct btrfs_block_rsv *block_rsv = NULL;
2956 int reserve = 0;
2957 int insert = 0;
2958 int ret;
2959
2960 if (!root->orphan_block_rsv) {
2961 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
2962 if (!block_rsv)
2963 return -ENOMEM;
2964 }
2965
2966 spin_lock(&root->orphan_lock);
2967 if (!root->orphan_block_rsv) {
2968 root->orphan_block_rsv = block_rsv;
2969 } else if (block_rsv) {
2970 btrfs_free_block_rsv(root, block_rsv);
2971 block_rsv = NULL;
2972 }
2973
2974 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
2975 &BTRFS_I(inode)->runtime_flags)) {
2976 #if 0
2977 /*
2978 * For proper ENOSPC handling, we should do orphan
2979 * cleanup when mounting. But this introduces backward
2980 * compatibility issue.
2981 */
2982 if (!xchg(&root->orphan_item_inserted, 1))
2983 insert = 2;
2984 else
2985 insert = 1;
2986 #endif
2987 insert = 1;
2988 atomic_inc(&root->orphan_inodes);
2989 }
2990
2991 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
2992 &BTRFS_I(inode)->runtime_flags))
2993 reserve = 1;
2994 spin_unlock(&root->orphan_lock);
2995
2996 /* grab metadata reservation from transaction handle */
2997 if (reserve) {
2998 ret = btrfs_orphan_reserve_metadata(trans, inode);
2999 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
3000 }
3001
3002 /* insert an orphan item to track this unlinked/truncated file */
3003 if (insert >= 1) {
3004 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3005 if (ret && ret != -EEXIST) {
3006 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3007 &BTRFS_I(inode)->runtime_flags);
3008 btrfs_abort_transaction(trans, root, ret);
3009 return ret;
3010 }
3011 ret = 0;
3012 }
3013
3014 /* insert an orphan item to track subvolume contains orphan files */
3015 if (insert >= 2) {
3016 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
3017 root->root_key.objectid);
3018 if (ret && ret != -EEXIST) {
3019 btrfs_abort_transaction(trans, root, ret);
3020 return ret;
3021 }
3022 }
3023 return 0;
3024 }
3025
3026 /*
3027 * We have done the truncate/delete so we can go ahead and remove the orphan
3028 * item for this particular inode.
3029 */
3030 int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode)
3031 {
3032 struct btrfs_root *root = BTRFS_I(inode)->root;
3033 int delete_item = 0;
3034 int release_rsv = 0;
3035 int ret = 0;
3036
3037 spin_lock(&root->orphan_lock);
3038 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3039 &BTRFS_I(inode)->runtime_flags))
3040 delete_item = 1;
3041
3042 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3043 &BTRFS_I(inode)->runtime_flags))
3044 release_rsv = 1;
3045 spin_unlock(&root->orphan_lock);
3046
3047 if (trans && delete_item) {
3048 ret = btrfs_del_orphan_item(trans, root, btrfs_ino(inode));
3049 BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */
3050 }
3051
3052 if (release_rsv) {
3053 btrfs_orphan_release_metadata(inode);
3054 atomic_dec(&root->orphan_inodes);
3055 }
3056
3057 return 0;
3058 }
3059
3060 /*
3061 * this cleans up any orphans that may be left on the list from the last use
3062 * of this root.
3063 */
3064 int btrfs_orphan_cleanup(struct btrfs_root *root)
3065 {
3066 struct btrfs_path *path;
3067 struct extent_buffer *leaf;
3068 struct btrfs_key key, found_key;
3069 struct btrfs_trans_handle *trans;
3070 struct inode *inode;
3071 u64 last_objectid = 0;
3072 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3073
3074 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3075 return 0;
3076
3077 path = btrfs_alloc_path();
3078 if (!path) {
3079 ret = -ENOMEM;
3080 goto out;
3081 }
3082 path->reada = -1;
3083
3084 key.objectid = BTRFS_ORPHAN_OBJECTID;
3085 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
3086 key.offset = (u64)-1;
3087
3088 while (1) {
3089 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3090 if (ret < 0)
3091 goto out;
3092
3093 /*
3094 * if ret == 0 means we found what we were searching for, which
3095 * is weird, but possible, so only screw with path if we didn't
3096 * find the key and see if we have stuff that matches
3097 */
3098 if (ret > 0) {
3099 ret = 0;
3100 if (path->slots[0] == 0)
3101 break;
3102 path->slots[0]--;
3103 }
3104
3105 /* pull out the item */
3106 leaf = path->nodes[0];
3107 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3108
3109 /* make sure the item matches what we want */
3110 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3111 break;
3112 if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
3113 break;
3114
3115 /* release the path since we're done with it */
3116 btrfs_release_path(path);
3117
3118 /*
3119 * this is where we are basically btrfs_lookup, without the
3120 * crossing root thing. we store the inode number in the
3121 * offset of the orphan item.
3122 */
3123
3124 if (found_key.offset == last_objectid) {
3125 btrfs_err(root->fs_info,
3126 "Error removing orphan entry, stopping orphan cleanup");
3127 ret = -EINVAL;
3128 goto out;
3129 }
3130
3131 last_objectid = found_key.offset;
3132
3133 found_key.objectid = found_key.offset;
3134 found_key.type = BTRFS_INODE_ITEM_KEY;
3135 found_key.offset = 0;
3136 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3137 ret = PTR_RET(inode);
3138 if (ret && ret != -ESTALE)
3139 goto out;
3140
3141 if (ret == -ESTALE && root == root->fs_info->tree_root) {
3142 struct btrfs_root *dead_root;
3143 struct btrfs_fs_info *fs_info = root->fs_info;
3144 int is_dead_root = 0;
3145
3146 /*
3147 * this is an orphan in the tree root. Currently these
3148 * could come from 2 sources:
3149 * a) a snapshot deletion in progress
3150 * b) a free space cache inode
3151 * We need to distinguish those two, as the snapshot
3152 * orphan must not get deleted.
3153 * find_dead_roots already ran before us, so if this
3154 * is a snapshot deletion, we should find the root
3155 * in the dead_roots list
3156 */
3157 spin_lock(&fs_info->trans_lock);
3158 list_for_each_entry(dead_root, &fs_info->dead_roots,
3159 root_list) {
3160 if (dead_root->root_key.objectid ==
3161 found_key.objectid) {
3162 is_dead_root = 1;
3163 break;
3164 }
3165 }
3166 spin_unlock(&fs_info->trans_lock);
3167 if (is_dead_root) {
3168 /* prevent this orphan from being found again */
3169 key.offset = found_key.objectid - 1;
3170 continue;
3171 }
3172 }
3173 /*
3174 * Inode is already gone but the orphan item is still there,
3175 * kill the orphan item.
3176 */
3177 if (ret == -ESTALE) {
3178 trans = btrfs_start_transaction(root, 1);
3179 if (IS_ERR(trans)) {
3180 ret = PTR_ERR(trans);
3181 goto out;
3182 }
3183 btrfs_debug(root->fs_info, "auto deleting %Lu",
3184 found_key.objectid);
3185 ret = btrfs_del_orphan_item(trans, root,
3186 found_key.objectid);
3187 BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */
3188 btrfs_end_transaction(trans, root);
3189 continue;
3190 }
3191
3192 /*
3193 * add this inode to the orphan list so btrfs_orphan_del does
3194 * the proper thing when we hit it
3195 */
3196 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3197 &BTRFS_I(inode)->runtime_flags);
3198 atomic_inc(&root->orphan_inodes);
3199
3200 /* if we have links, this was a truncate, lets do that */
3201 if (inode->i_nlink) {
3202 if (!S_ISREG(inode->i_mode)) {
3203 WARN_ON(1);
3204 iput(inode);
3205 continue;
3206 }
3207 nr_truncate++;
3208
3209 /* 1 for the orphan item deletion. */
3210 trans = btrfs_start_transaction(root, 1);
3211 if (IS_ERR(trans)) {
3212 ret = PTR_ERR(trans);
3213 goto out;
3214 }
3215 ret = btrfs_orphan_add(trans, inode);
3216 btrfs_end_transaction(trans, root);
3217 if (ret)
3218 goto out;
3219
3220 ret = btrfs_truncate(inode);
3221 if (ret)
3222 btrfs_orphan_del(NULL, inode);
3223 } else {
3224 nr_unlink++;
3225 }
3226
3227 /* this will do delete_inode and everything for us */
3228 iput(inode);
3229 if (ret)
3230 goto out;
3231 }
3232 /* release the path since we're done with it */
3233 btrfs_release_path(path);
3234
3235 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3236
3237 if (root->orphan_block_rsv)
3238 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3239 (u64)-1);
3240
3241 if (root->orphan_block_rsv || root->orphan_item_inserted) {
3242 trans = btrfs_join_transaction(root);
3243 if (!IS_ERR(trans))
3244 btrfs_end_transaction(trans, root);
3245 }
3246
3247 if (nr_unlink)
3248 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3249 if (nr_truncate)
3250 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3251
3252 out:
3253 if (ret)
3254 btrfs_crit(root->fs_info,
3255 "could not do orphan cleanup %d", ret);
3256 btrfs_free_path(path);
3257 return ret;
3258 }
3259
3260 /*
3261 * very simple check to peek ahead in the leaf looking for xattrs. If we
3262 * don't find any xattrs, we know there can't be any acls.
3263 *
3264 * slot is the slot the inode is in, objectid is the objectid of the inode
3265 */
3266 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3267 int slot, u64 objectid)
3268 {
3269 u32 nritems = btrfs_header_nritems(leaf);
3270 struct btrfs_key found_key;
3271 int scanned = 0;
3272
3273 slot++;
3274 while (slot < nritems) {
3275 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3276
3277 /* we found a different objectid, there must not be acls */
3278 if (found_key.objectid != objectid)
3279 return 0;
3280
3281 /* we found an xattr, assume we've got an acl */
3282 if (found_key.type == BTRFS_XATTR_ITEM_KEY)
3283 return 1;
3284
3285 /*
3286 * we found a key greater than an xattr key, there can't
3287 * be any acls later on
3288 */
3289 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3290 return 0;
3291
3292 slot++;
3293 scanned++;
3294
3295 /*
3296 * it goes inode, inode backrefs, xattrs, extents,
3297 * so if there are a ton of hard links to an inode there can
3298 * be a lot of backrefs. Don't waste time searching too hard,
3299 * this is just an optimization
3300 */
3301 if (scanned >= 8)
3302 break;
3303 }
3304 /* we hit the end of the leaf before we found an xattr or
3305 * something larger than an xattr. We have to assume the inode
3306 * has acls
3307 */
3308 return 1;
3309 }
3310
3311 /*
3312 * read an inode from the btree into the in-memory inode
3313 */
3314 static void btrfs_read_locked_inode(struct inode *inode)
3315 {
3316 struct btrfs_path *path;
3317 struct extent_buffer *leaf;
3318 struct btrfs_inode_item *inode_item;
3319 struct btrfs_timespec *tspec;
3320 struct btrfs_root *root = BTRFS_I(inode)->root;
3321 struct btrfs_key location;
3322 int maybe_acls;
3323 u32 rdev;
3324 int ret;
3325 bool filled = false;
3326
3327 ret = btrfs_fill_inode(inode, &rdev);
3328 if (!ret)
3329 filled = true;
3330
3331 path = btrfs_alloc_path();
3332 if (!path)
3333 goto make_bad;
3334
3335 path->leave_spinning = 1;
3336 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3337
3338 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3339 if (ret)
3340 goto make_bad;
3341
3342 leaf = path->nodes[0];
3343
3344 if (filled)
3345 goto cache_acl;
3346
3347 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3348 struct btrfs_inode_item);
3349 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3350 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3351 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3352 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3353 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3354
3355 tspec = btrfs_inode_atime(inode_item);
3356 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3357 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3358
3359 tspec = btrfs_inode_mtime(inode_item);
3360 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3361 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3362
3363 tspec = btrfs_inode_ctime(inode_item);
3364 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
3365 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
3366
3367 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3368 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3369 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3370
3371 /*
3372 * If we were modified in the current generation and evicted from memory
3373 * and then re-read we need to do a full sync since we don't have any
3374 * idea about which extents were modified before we were evicted from
3375 * cache.
3376 */
3377 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3378 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3379 &BTRFS_I(inode)->runtime_flags);
3380
3381 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3382 inode->i_generation = BTRFS_I(inode)->generation;
3383 inode->i_rdev = 0;
3384 rdev = btrfs_inode_rdev(leaf, inode_item);
3385
3386 BTRFS_I(inode)->index_cnt = (u64)-1;
3387 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3388 cache_acl:
3389 /*
3390 * try to precache a NULL acl entry for files that don't have
3391 * any xattrs or acls
3392 */
3393 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3394 btrfs_ino(inode));
3395 if (!maybe_acls)
3396 cache_no_acl(inode);
3397
3398 btrfs_free_path(path);
3399
3400 switch (inode->i_mode & S_IFMT) {
3401 case S_IFREG:
3402 inode->i_mapping->a_ops = &btrfs_aops;
3403 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3404 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3405 inode->i_fop = &btrfs_file_operations;
3406 inode->i_op = &btrfs_file_inode_operations;
3407 break;
3408 case S_IFDIR:
3409 inode->i_fop = &btrfs_dir_file_operations;
3410 if (root == root->fs_info->tree_root)
3411 inode->i_op = &btrfs_dir_ro_inode_operations;
3412 else
3413 inode->i_op = &btrfs_dir_inode_operations;
3414 break;
3415 case S_IFLNK:
3416 inode->i_op = &btrfs_symlink_inode_operations;
3417 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3418 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
3419 break;
3420 default:
3421 inode->i_op = &btrfs_special_inode_operations;
3422 init_special_inode(inode, inode->i_mode, rdev);
3423 break;
3424 }
3425
3426 btrfs_update_iflags(inode);
3427 return;
3428
3429 make_bad:
3430 btrfs_free_path(path);
3431 make_bad_inode(inode);
3432 }
3433
3434 /*
3435 * given a leaf and an inode, copy the inode fields into the leaf
3436 */
3437 static void fill_inode_item(struct btrfs_trans_handle *trans,
3438 struct extent_buffer *leaf,
3439 struct btrfs_inode_item *item,
3440 struct inode *inode)
3441 {
3442 struct btrfs_map_token token;
3443
3444 btrfs_init_map_token(&token);
3445
3446 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3447 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3448 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3449 &token);
3450 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3451 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3452
3453 btrfs_set_token_timespec_sec(leaf, btrfs_inode_atime(item),
3454 inode->i_atime.tv_sec, &token);
3455 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_atime(item),
3456 inode->i_atime.tv_nsec, &token);
3457
3458 btrfs_set_token_timespec_sec(leaf, btrfs_inode_mtime(item),
3459 inode->i_mtime.tv_sec, &token);
3460 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_mtime(item),
3461 inode->i_mtime.tv_nsec, &token);
3462
3463 btrfs_set_token_timespec_sec(leaf, btrfs_inode_ctime(item),
3464 inode->i_ctime.tv_sec, &token);
3465 btrfs_set_token_timespec_nsec(leaf, btrfs_inode_ctime(item),
3466 inode->i_ctime.tv_nsec, &token);
3467
3468 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3469 &token);
3470 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3471 &token);
3472 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3473 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3474 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3475 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3476 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3477 }
3478
3479 /*
3480 * copy everything in the in-memory inode into the btree.
3481 */
3482 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3483 struct btrfs_root *root, struct inode *inode)
3484 {
3485 struct btrfs_inode_item *inode_item;
3486 struct btrfs_path *path;
3487 struct extent_buffer *leaf;
3488 int ret;
3489
3490 path = btrfs_alloc_path();
3491 if (!path)
3492 return -ENOMEM;
3493
3494 path->leave_spinning = 1;
3495 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3496 1);
3497 if (ret) {
3498 if (ret > 0)
3499 ret = -ENOENT;
3500 goto failed;
3501 }
3502
3503 btrfs_unlock_up_safe(path, 1);
3504 leaf = path->nodes[0];
3505 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3506 struct btrfs_inode_item);
3507
3508 fill_inode_item(trans, leaf, inode_item, inode);
3509 btrfs_mark_buffer_dirty(leaf);
3510 btrfs_set_inode_last_trans(trans, inode);
3511 ret = 0;
3512 failed:
3513 btrfs_free_path(path);
3514 return ret;
3515 }
3516
3517 /*
3518 * copy everything in the in-memory inode into the btree.
3519 */
3520 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3521 struct btrfs_root *root, struct inode *inode)
3522 {
3523 int ret;
3524
3525 /*
3526 * If the inode is a free space inode, we can deadlock during commit
3527 * if we put it into the delayed code.
3528 *
3529 * The data relocation inode should also be directly updated
3530 * without delay
3531 */
3532 if (!btrfs_is_free_space_inode(inode)
3533 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) {
3534 btrfs_update_root_times(trans, root);
3535
3536 ret = btrfs_delayed_update_inode(trans, root, inode);
3537 if (!ret)
3538 btrfs_set_inode_last_trans(trans, inode);
3539 return ret;
3540 }
3541
3542 return btrfs_update_inode_item(trans, root, inode);
3543 }
3544
3545 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3546 struct btrfs_root *root,
3547 struct inode *inode)
3548 {
3549 int ret;
3550
3551 ret = btrfs_update_inode(trans, root, inode);
3552 if (ret == -ENOSPC)
3553 return btrfs_update_inode_item(trans, root, inode);
3554 return ret;
3555 }
3556
3557 /*
3558 * unlink helper that gets used here in inode.c and in the tree logging
3559 * recovery code. It remove a link in a directory with a given name, and
3560 * also drops the back refs in the inode to the directory
3561 */
3562 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3563 struct btrfs_root *root,
3564 struct inode *dir, struct inode *inode,
3565 const char *name, int name_len)
3566 {
3567 struct btrfs_path *path;
3568 int ret = 0;
3569 struct extent_buffer *leaf;
3570 struct btrfs_dir_item *di;
3571 struct btrfs_key key;
3572 u64 index;
3573 u64 ino = btrfs_ino(inode);
3574 u64 dir_ino = btrfs_ino(dir);
3575
3576 path = btrfs_alloc_path();
3577 if (!path) {
3578 ret = -ENOMEM;
3579 goto out;
3580 }
3581
3582 path->leave_spinning = 1;
3583 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3584 name, name_len, -1);
3585 if (IS_ERR(di)) {
3586 ret = PTR_ERR(di);
3587 goto err;
3588 }
3589 if (!di) {
3590 ret = -ENOENT;
3591 goto err;
3592 }
3593 leaf = path->nodes[0];
3594 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3595 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3596 if (ret)
3597 goto err;
3598 btrfs_release_path(path);
3599
3600 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
3601 dir_ino, &index);
3602 if (ret) {
3603 btrfs_info(root->fs_info,
3604 "failed to delete reference to %.*s, inode %llu parent %llu",
3605 name_len, name,
3606 (unsigned long long)ino, (unsigned long long)dir_ino);
3607 btrfs_abort_transaction(trans, root, ret);
3608 goto err;
3609 }
3610
3611 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3612 if (ret) {
3613 btrfs_abort_transaction(trans, root, ret);
3614 goto err;
3615 }
3616
3617 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
3618 inode, dir_ino);
3619 if (ret != 0 && ret != -ENOENT) {
3620 btrfs_abort_transaction(trans, root, ret);
3621 goto err;
3622 }
3623
3624 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
3625 dir, index);
3626 if (ret == -ENOENT)
3627 ret = 0;
3628 err:
3629 btrfs_free_path(path);
3630 if (ret)
3631 goto out;
3632
3633 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3634 inode_inc_iversion(inode);
3635 inode_inc_iversion(dir);
3636 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3637 ret = btrfs_update_inode(trans, root, dir);
3638 out:
3639 return ret;
3640 }
3641
3642 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3643 struct btrfs_root *root,
3644 struct inode *dir, struct inode *inode,
3645 const char *name, int name_len)
3646 {
3647 int ret;
3648 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
3649 if (!ret) {
3650 btrfs_drop_nlink(inode);
3651 ret = btrfs_update_inode(trans, root, inode);
3652 }
3653 return ret;
3654 }
3655
3656
3657 /* helper to check if there is any shared block in the path */
3658 static int check_path_shared(struct btrfs_root *root,
3659 struct btrfs_path *path)
3660 {
3661 struct extent_buffer *eb;
3662 int level;
3663 u64 refs = 1;
3664
3665 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
3666 int ret;
3667
3668 if (!path->nodes[level])
3669 break;
3670 eb = path->nodes[level];
3671 if (!btrfs_block_can_be_shared(root, eb))
3672 continue;
3673 ret = btrfs_lookup_extent_info(NULL, root, eb->start, level, 1,
3674 &refs, NULL);
3675 if (refs > 1)
3676 return 1;
3677 }
3678 return 0;
3679 }
3680
3681 /*
3682 * helper to start transaction for unlink and rmdir.
3683 *
3684 * unlink and rmdir are special in btrfs, they do not always free space.
3685 * so in enospc case, we should make sure they will free space before
3686 * allowing them to use the global metadata reservation.
3687 */
3688 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
3689 struct dentry *dentry)
3690 {
3691 struct btrfs_trans_handle *trans;
3692 struct btrfs_root *root = BTRFS_I(dir)->root;
3693 struct btrfs_path *path;
3694 struct btrfs_dir_item *di;
3695 struct inode *inode = dentry->d_inode;
3696 u64 index;
3697 int check_link = 1;
3698 int err = -ENOSPC;
3699 int ret;
3700 u64 ino = btrfs_ino(inode);
3701 u64 dir_ino = btrfs_ino(dir);
3702
3703 /*
3704 * 1 for the possible orphan item
3705 * 1 for the dir item
3706 * 1 for the dir index
3707 * 1 for the inode ref
3708 * 1 for the inode
3709 */
3710 trans = btrfs_start_transaction(root, 5);
3711 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
3712 return trans;
3713
3714 if (ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
3715 return ERR_PTR(-ENOSPC);
3716
3717 /* check if there is someone else holds reference */
3718 if (S_ISDIR(inode->i_mode) && atomic_read(&inode->i_count) > 1)
3719 return ERR_PTR(-ENOSPC);
3720
3721 if (atomic_read(&inode->i_count) > 2)
3722 return ERR_PTR(-ENOSPC);
3723
3724 if (xchg(&root->fs_info->enospc_unlink, 1))
3725 return ERR_PTR(-ENOSPC);
3726
3727 path = btrfs_alloc_path();
3728 if (!path) {
3729 root->fs_info->enospc_unlink = 0;
3730 return ERR_PTR(-ENOMEM);
3731 }
3732
3733 /* 1 for the orphan item */
3734 trans = btrfs_start_transaction(root, 1);
3735 if (IS_ERR(trans)) {
3736 btrfs_free_path(path);
3737 root->fs_info->enospc_unlink = 0;
3738 return trans;
3739 }
3740
3741 path->skip_locking = 1;
3742 path->search_commit_root = 1;
3743
3744 ret = btrfs_lookup_inode(trans, root, path,
3745 &BTRFS_I(dir)->location, 0);
3746 if (ret < 0) {
3747 err = ret;
3748 goto out;
3749 }
3750 if (ret == 0) {
3751 if (check_path_shared(root, path))
3752 goto out;
3753 } else {
3754 check_link = 0;
3755 }
3756 btrfs_release_path(path);
3757
3758 ret = btrfs_lookup_inode(trans, root, path,
3759 &BTRFS_I(inode)->location, 0);
3760 if (ret < 0) {
3761 err = ret;
3762 goto out;
3763 }
3764 if (ret == 0) {
3765 if (check_path_shared(root, path))
3766 goto out;
3767 } else {
3768 check_link = 0;
3769 }
3770 btrfs_release_path(path);
3771
3772 if (ret == 0 && S_ISREG(inode->i_mode)) {
3773 ret = btrfs_lookup_file_extent(trans, root, path,
3774 ino, (u64)-1, 0);
3775 if (ret < 0) {
3776 err = ret;
3777 goto out;
3778 }
3779 BUG_ON(ret == 0); /* Corruption */
3780 if (check_path_shared(root, path))
3781 goto out;
3782 btrfs_release_path(path);
3783 }
3784
3785 if (!check_link) {
3786 err = 0;
3787 goto out;
3788 }
3789
3790 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3791 dentry->d_name.name, dentry->d_name.len, 0);
3792 if (IS_ERR(di)) {
3793 err = PTR_ERR(di);
3794 goto out;
3795 }
3796 if (di) {
3797 if (check_path_shared(root, path))
3798 goto out;
3799 } else {
3800 err = 0;
3801 goto out;
3802 }
3803 btrfs_release_path(path);
3804
3805 ret = btrfs_get_inode_ref_index(trans, root, path, dentry->d_name.name,
3806 dentry->d_name.len, ino, dir_ino, 0,
3807 &index);
3808 if (ret) {
3809 err = ret;
3810 goto out;
3811 }
3812
3813 if (check_path_shared(root, path))
3814 goto out;
3815
3816 btrfs_release_path(path);
3817
3818 /*
3819 * This is a commit root search, if we can lookup inode item and other
3820 * relative items in the commit root, it means the transaction of
3821 * dir/file creation has been committed, and the dir index item that we
3822 * delay to insert has also been inserted into the commit root. So
3823 * we needn't worry about the delayed insertion of the dir index item
3824 * here.
3825 */
3826 di = btrfs_lookup_dir_index_item(trans, root, path, dir_ino, index,
3827 dentry->d_name.name, dentry->d_name.len, 0);
3828 if (IS_ERR(di)) {
3829 err = PTR_ERR(di);
3830 goto out;
3831 }
3832 BUG_ON(ret == -ENOENT);
3833 if (check_path_shared(root, path))
3834 goto out;
3835
3836 err = 0;
3837 out:
3838 btrfs_free_path(path);
3839 /* Migrate the orphan reservation over */
3840 if (!err)
3841 err = btrfs_block_rsv_migrate(trans->block_rsv,
3842 &root->fs_info->global_block_rsv,
3843 trans->bytes_reserved);
3844
3845 if (err) {
3846 btrfs_end_transaction(trans, root);
3847 root->fs_info->enospc_unlink = 0;
3848 return ERR_PTR(err);
3849 }
3850
3851 trans->block_rsv = &root->fs_info->global_block_rsv;
3852 return trans;
3853 }
3854
3855 static void __unlink_end_trans(struct btrfs_trans_handle *trans,
3856 struct btrfs_root *root)
3857 {
3858 if (trans->block_rsv->type == BTRFS_BLOCK_RSV_GLOBAL) {
3859 btrfs_block_rsv_release(root, trans->block_rsv,
3860 trans->bytes_reserved);
3861 trans->block_rsv = &root->fs_info->trans_block_rsv;
3862 BUG_ON(!root->fs_info->enospc_unlink);
3863 root->fs_info->enospc_unlink = 0;
3864 }
3865 btrfs_end_transaction(trans, root);
3866 }
3867
3868 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
3869 {
3870 struct btrfs_root *root = BTRFS_I(dir)->root;
3871 struct btrfs_trans_handle *trans;
3872 struct inode *inode = dentry->d_inode;
3873 int ret;
3874
3875 trans = __unlink_start_trans(dir, dentry);
3876 if (IS_ERR(trans))
3877 return PTR_ERR(trans);
3878
3879 btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0);
3880
3881 ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3882 dentry->d_name.name, dentry->d_name.len);
3883 if (ret)
3884 goto out;
3885
3886 if (inode->i_nlink == 0) {
3887 ret = btrfs_orphan_add(trans, inode);
3888 if (ret)
3889 goto out;
3890 }
3891
3892 out:
3893 __unlink_end_trans(trans, root);
3894 btrfs_btree_balance_dirty(root);
3895 return ret;
3896 }
3897
3898 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
3899 struct btrfs_root *root,
3900 struct inode *dir, u64 objectid,
3901 const char *name, int name_len)
3902 {
3903 struct btrfs_path *path;
3904 struct extent_buffer *leaf;
3905 struct btrfs_dir_item *di;
3906 struct btrfs_key key;
3907 u64 index;
3908 int ret;
3909 u64 dir_ino = btrfs_ino(dir);
3910
3911 path = btrfs_alloc_path();
3912 if (!path)
3913 return -ENOMEM;
3914
3915 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3916 name, name_len, -1);
3917 if (IS_ERR_OR_NULL(di)) {
3918 if (!di)
3919 ret = -ENOENT;
3920 else
3921 ret = PTR_ERR(di);
3922 goto out;
3923 }
3924
3925 leaf = path->nodes[0];
3926 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3927 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
3928 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3929 if (ret) {
3930 btrfs_abort_transaction(trans, root, ret);
3931 goto out;
3932 }
3933 btrfs_release_path(path);
3934
3935 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
3936 objectid, root->root_key.objectid,
3937 dir_ino, &index, name, name_len);
3938 if (ret < 0) {
3939 if (ret != -ENOENT) {
3940 btrfs_abort_transaction(trans, root, ret);
3941 goto out;
3942 }
3943 di = btrfs_search_dir_index_item(root, path, dir_ino,
3944 name, name_len);
3945 if (IS_ERR_OR_NULL(di)) {
3946 if (!di)
3947 ret = -ENOENT;
3948 else
3949 ret = PTR_ERR(di);
3950 btrfs_abort_transaction(trans, root, ret);
3951 goto out;
3952 }
3953
3954 leaf = path->nodes[0];
3955 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3956 btrfs_release_path(path);
3957 index = key.offset;
3958 }
3959 btrfs_release_path(path);
3960
3961 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3962 if (ret) {
3963 btrfs_abort_transaction(trans, root, ret);
3964 goto out;
3965 }
3966
3967 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3968 inode_inc_iversion(dir);
3969 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3970 ret = btrfs_update_inode_fallback(trans, root, dir);
3971 if (ret)
3972 btrfs_abort_transaction(trans, root, ret);
3973 out:
3974 btrfs_free_path(path);
3975 return ret;
3976 }
3977
3978 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
3979 {
3980 struct inode *inode = dentry->d_inode;
3981 int err = 0;
3982 struct btrfs_root *root = BTRFS_I(dir)->root;
3983 struct btrfs_trans_handle *trans;
3984
3985 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
3986 return -ENOTEMPTY;
3987 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
3988 return -EPERM;
3989
3990 trans = __unlink_start_trans(dir, dentry);
3991 if (IS_ERR(trans))
3992 return PTR_ERR(trans);
3993
3994 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
3995 err = btrfs_unlink_subvol(trans, root, dir,
3996 BTRFS_I(inode)->location.objectid,
3997 dentry->d_name.name,
3998 dentry->d_name.len);
3999 goto out;
4000 }
4001
4002 err = btrfs_orphan_add(trans, inode);
4003 if (err)
4004 goto out;
4005
4006 /* now the directory is empty */
4007 err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
4008 dentry->d_name.name, dentry->d_name.len);
4009 if (!err)
4010 btrfs_i_size_write(inode, 0);
4011 out:
4012 __unlink_end_trans(trans, root);
4013 btrfs_btree_balance_dirty(root);
4014
4015 return err;
4016 }
4017
4018 /*
4019 * this can truncate away extent items, csum items and directory items.
4020 * It starts at a high offset and removes keys until it can't find
4021 * any higher than new_size
4022 *
4023 * csum items that cross the new i_size are truncated to the new size
4024 * as well.
4025 *
4026 * min_type is the minimum key type to truncate down to. If set to 0, this
4027 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4028 */
4029 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4030 struct btrfs_root *root,
4031 struct inode *inode,
4032 u64 new_size, u32 min_type)
4033 {
4034 struct btrfs_path *path;
4035 struct extent_buffer *leaf;
4036 struct btrfs_file_extent_item *fi;
4037 struct btrfs_key key;
4038 struct btrfs_key found_key;
4039 u64 extent_start = 0;
4040 u64 extent_num_bytes = 0;
4041 u64 extent_offset = 0;
4042 u64 item_end = 0;
4043 u32 found_type = (u8)-1;
4044 int found_extent;
4045 int del_item;
4046 int pending_del_nr = 0;
4047 int pending_del_slot = 0;
4048 int extent_type = -1;
4049 int ret;
4050 int err = 0;
4051 u64 ino = btrfs_ino(inode);
4052
4053 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4054
4055 path = btrfs_alloc_path();
4056 if (!path)
4057 return -ENOMEM;
4058 path->reada = -1;
4059
4060 /*
4061 * We want to drop from the next block forward in case this new size is
4062 * not block aligned since we will be keeping the last block of the
4063 * extent just the way it is.
4064 */
4065 if (root->ref_cows || root == root->fs_info->tree_root)
4066 btrfs_drop_extent_cache(inode, ALIGN(new_size,
4067 root->sectorsize), (u64)-1, 0);
4068
4069 /*
4070 * This function is also used to drop the items in the log tree before
4071 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4072 * it is used to drop the loged items. So we shouldn't kill the delayed
4073 * items.
4074 */
4075 if (min_type == 0 && root == BTRFS_I(inode)->root)
4076 btrfs_kill_delayed_inode_items(inode);
4077
4078 key.objectid = ino;
4079 key.offset = (u64)-1;
4080 key.type = (u8)-1;
4081
4082 search_again:
4083 path->leave_spinning = 1;
4084 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4085 if (ret < 0) {
4086 err = ret;
4087 goto out;
4088 }
4089
4090 if (ret > 0) {
4091 /* there are no items in the tree for us to truncate, we're
4092 * done
4093 */
4094 if (path->slots[0] == 0)
4095 goto out;
4096 path->slots[0]--;
4097 }
4098
4099 while (1) {
4100 fi = NULL;
4101 leaf = path->nodes[0];
4102 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4103 found_type = btrfs_key_type(&found_key);
4104
4105 if (found_key.objectid != ino)
4106 break;
4107
4108 if (found_type < min_type)
4109 break;
4110
4111 item_end = found_key.offset;
4112 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4113 fi = btrfs_item_ptr(leaf, path->slots[0],
4114 struct btrfs_file_extent_item);
4115 extent_type = btrfs_file_extent_type(leaf, fi);
4116 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4117 item_end +=
4118 btrfs_file_extent_num_bytes(leaf, fi);
4119 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4120 item_end += btrfs_file_extent_inline_len(leaf,
4121 fi);
4122 }
4123 item_end--;
4124 }
4125 if (found_type > min_type) {
4126 del_item = 1;
4127 } else {
4128 if (item_end < new_size)
4129 break;
4130 if (found_key.offset >= new_size)
4131 del_item = 1;
4132 else
4133 del_item = 0;
4134 }
4135 found_extent = 0;
4136 /* FIXME, shrink the extent if the ref count is only 1 */
4137 if (found_type != BTRFS_EXTENT_DATA_KEY)
4138 goto delete;
4139
4140 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4141 u64 num_dec;
4142 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4143 if (!del_item) {
4144 u64 orig_num_bytes =
4145 btrfs_file_extent_num_bytes(leaf, fi);
4146 extent_num_bytes = ALIGN(new_size -
4147 found_key.offset,
4148 root->sectorsize);
4149 btrfs_set_file_extent_num_bytes(leaf, fi,
4150 extent_num_bytes);
4151 num_dec = (orig_num_bytes -
4152 extent_num_bytes);
4153 if (root->ref_cows && extent_start != 0)
4154 inode_sub_bytes(inode, num_dec);
4155 btrfs_mark_buffer_dirty(leaf);
4156 } else {
4157 extent_num_bytes =
4158 btrfs_file_extent_disk_num_bytes(leaf,
4159 fi);
4160 extent_offset = found_key.offset -
4161 btrfs_file_extent_offset(leaf, fi);
4162
4163 /* FIXME blocksize != 4096 */
4164 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4165 if (extent_start != 0) {
4166 found_extent = 1;
4167 if (root->ref_cows)
4168 inode_sub_bytes(inode, num_dec);
4169 }
4170 }
4171 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4172 /*
4173 * we can't truncate inline items that have had
4174 * special encodings
4175 */
4176 if (!del_item &&
4177 btrfs_file_extent_compression(leaf, fi) == 0 &&
4178 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4179 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4180 u32 size = new_size - found_key.offset;
4181
4182 if (root->ref_cows) {
4183 inode_sub_bytes(inode, item_end + 1 -
4184 new_size);
4185 }
4186 size =
4187 btrfs_file_extent_calc_inline_size(size);
4188 btrfs_truncate_item(trans, root, path,
4189 size, 1);
4190 } else if (root->ref_cows) {
4191 inode_sub_bytes(inode, item_end + 1 -
4192 found_key.offset);
4193 }
4194 }
4195 delete:
4196 if (del_item) {
4197 if (!pending_del_nr) {
4198 /* no pending yet, add ourselves */
4199 pending_del_slot = path->slots[0];
4200 pending_del_nr = 1;
4201 } else if (pending_del_nr &&
4202 path->slots[0] + 1 == pending_del_slot) {
4203 /* hop on the pending chunk */
4204 pending_del_nr++;
4205 pending_del_slot = path->slots[0];
4206 } else {
4207 BUG();
4208 }
4209 } else {
4210 break;
4211 }
4212 if (found_extent && (root->ref_cows ||
4213 root == root->fs_info->tree_root)) {
4214 btrfs_set_path_blocking(path);
4215 ret = btrfs_free_extent(trans, root, extent_start,
4216 extent_num_bytes, 0,
4217 btrfs_header_owner(leaf),
4218 ino, extent_offset, 0);
4219 BUG_ON(ret);
4220 }
4221
4222 if (found_type == BTRFS_INODE_ITEM_KEY)
4223 break;
4224
4225 if (path->slots[0] == 0 ||
4226 path->slots[0] != pending_del_slot) {
4227 if (pending_del_nr) {
4228 ret = btrfs_del_items(trans, root, path,
4229 pending_del_slot,
4230 pending_del_nr);
4231 if (ret) {
4232 btrfs_abort_transaction(trans,
4233 root, ret);
4234 goto error;
4235 }
4236 pending_del_nr = 0;
4237 }
4238 btrfs_release_path(path);
4239 goto search_again;
4240 } else {
4241 path->slots[0]--;
4242 }
4243 }
4244 out:
4245 if (pending_del_nr) {
4246 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4247 pending_del_nr);
4248 if (ret)
4249 btrfs_abort_transaction(trans, root, ret);
4250 }
4251 error:
4252 btrfs_free_path(path);
4253 return err;
4254 }
4255
4256 /*
4257 * btrfs_truncate_page - read, zero a chunk and write a page
4258 * @inode - inode that we're zeroing
4259 * @from - the offset to start zeroing
4260 * @len - the length to zero, 0 to zero the entire range respective to the
4261 * offset
4262 * @front - zero up to the offset instead of from the offset on
4263 *
4264 * This will find the page for the "from" offset and cow the page and zero the
4265 * part we want to zero. This is used with truncate and hole punching.
4266 */
4267 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
4268 int front)
4269 {
4270 struct address_space *mapping = inode->i_mapping;
4271 struct btrfs_root *root = BTRFS_I(inode)->root;
4272 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4273 struct btrfs_ordered_extent *ordered;
4274 struct extent_state *cached_state = NULL;
4275 char *kaddr;
4276 u32 blocksize = root->sectorsize;
4277 pgoff_t index = from >> PAGE_CACHE_SHIFT;
4278 unsigned offset = from & (PAGE_CACHE_SIZE-1);
4279 struct page *page;
4280 gfp_t mask = btrfs_alloc_write_mask(mapping);
4281 int ret = 0;
4282 u64 page_start;
4283 u64 page_end;
4284
4285 if ((offset & (blocksize - 1)) == 0 &&
4286 (!len || ((len & (blocksize - 1)) == 0)))
4287 goto out;
4288 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
4289 if (ret)
4290 goto out;
4291
4292 again:
4293 page = find_or_create_page(mapping, index, mask);
4294 if (!page) {
4295 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4296 ret = -ENOMEM;
4297 goto out;
4298 }
4299
4300 page_start = page_offset(page);
4301 page_end = page_start + PAGE_CACHE_SIZE - 1;
4302
4303 if (!PageUptodate(page)) {
4304 ret = btrfs_readpage(NULL, page);
4305 lock_page(page);
4306 if (page->mapping != mapping) {
4307 unlock_page(page);
4308 page_cache_release(page);
4309 goto again;
4310 }
4311 if (!PageUptodate(page)) {
4312 ret = -EIO;
4313 goto out_unlock;
4314 }
4315 }
4316 wait_on_page_writeback(page);
4317
4318 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
4319 set_page_extent_mapped(page);
4320
4321 ordered = btrfs_lookup_ordered_extent(inode, page_start);
4322 if (ordered) {
4323 unlock_extent_cached(io_tree, page_start, page_end,
4324 &cached_state, GFP_NOFS);
4325 unlock_page(page);
4326 page_cache_release(page);
4327 btrfs_start_ordered_extent(inode, ordered, 1);
4328 btrfs_put_ordered_extent(ordered);
4329 goto again;
4330 }
4331
4332 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
4333 EXTENT_DIRTY | EXTENT_DELALLOC |
4334 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4335 0, 0, &cached_state, GFP_NOFS);
4336
4337 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
4338 &cached_state);
4339 if (ret) {
4340 unlock_extent_cached(io_tree, page_start, page_end,
4341 &cached_state, GFP_NOFS);
4342 goto out_unlock;
4343 }
4344
4345 if (offset != PAGE_CACHE_SIZE) {
4346 if (!len)
4347 len = PAGE_CACHE_SIZE - offset;
4348 kaddr = kmap(page);
4349 if (front)
4350 memset(kaddr, 0, offset);
4351 else
4352 memset(kaddr + offset, 0, len);
4353 flush_dcache_page(page);
4354 kunmap(page);
4355 }
4356 ClearPageChecked(page);
4357 set_page_dirty(page);
4358 unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
4359 GFP_NOFS);
4360
4361 out_unlock:
4362 if (ret)
4363 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4364 unlock_page(page);
4365 page_cache_release(page);
4366 out:
4367 return ret;
4368 }
4369
4370 /*
4371 * This function puts in dummy file extents for the area we're creating a hole
4372 * for. So if we are truncating this file to a larger size we need to insert
4373 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4374 * the range between oldsize and size
4375 */
4376 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4377 {
4378 struct btrfs_trans_handle *trans;
4379 struct btrfs_root *root = BTRFS_I(inode)->root;
4380 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4381 struct extent_map *em = NULL;
4382 struct extent_state *cached_state = NULL;
4383 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4384 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4385 u64 block_end = ALIGN(size, root->sectorsize);
4386 u64 last_byte;
4387 u64 cur_offset;
4388 u64 hole_size;
4389 int err = 0;
4390
4391 if (size <= hole_start)
4392 return 0;
4393
4394 while (1) {
4395 struct btrfs_ordered_extent *ordered;
4396 btrfs_wait_ordered_range(inode, hole_start,
4397 block_end - hole_start);
4398 lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
4399 &cached_state);
4400 ordered = btrfs_lookup_ordered_extent(inode, hole_start);
4401 if (!ordered)
4402 break;
4403 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4404 &cached_state, GFP_NOFS);
4405 btrfs_put_ordered_extent(ordered);
4406 }
4407
4408 cur_offset = hole_start;
4409 while (1) {
4410 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4411 block_end - cur_offset, 0);
4412 if (IS_ERR(em)) {
4413 err = PTR_ERR(em);
4414 em = NULL;
4415 break;
4416 }
4417 last_byte = min(extent_map_end(em), block_end);
4418 last_byte = ALIGN(last_byte , root->sectorsize);
4419 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4420 struct extent_map *hole_em;
4421 hole_size = last_byte - cur_offset;
4422
4423 trans = btrfs_start_transaction(root, 3);
4424 if (IS_ERR(trans)) {
4425 err = PTR_ERR(trans);
4426 break;
4427 }
4428
4429 err = btrfs_drop_extents(trans, root, inode,
4430 cur_offset,
4431 cur_offset + hole_size, 1);
4432 if (err) {
4433 btrfs_abort_transaction(trans, root, err);
4434 btrfs_end_transaction(trans, root);
4435 break;
4436 }
4437
4438 err = btrfs_insert_file_extent(trans, root,
4439 btrfs_ino(inode), cur_offset, 0,
4440 0, hole_size, 0, hole_size,
4441 0, 0, 0);
4442 if (err) {
4443 btrfs_abort_transaction(trans, root, err);
4444 btrfs_end_transaction(trans, root);
4445 break;
4446 }
4447
4448 btrfs_drop_extent_cache(inode, cur_offset,
4449 cur_offset + hole_size - 1, 0);
4450 hole_em = alloc_extent_map();
4451 if (!hole_em) {
4452 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4453 &BTRFS_I(inode)->runtime_flags);
4454 goto next;
4455 }
4456 hole_em->start = cur_offset;
4457 hole_em->len = hole_size;
4458 hole_em->orig_start = cur_offset;
4459
4460 hole_em->block_start = EXTENT_MAP_HOLE;
4461 hole_em->block_len = 0;
4462 hole_em->orig_block_len = 0;
4463 hole_em->ram_bytes = hole_size;
4464 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4465 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4466 hole_em->generation = trans->transid;
4467
4468 while (1) {
4469 write_lock(&em_tree->lock);
4470 err = add_extent_mapping(em_tree, hole_em);
4471 if (!err)
4472 list_move(&hole_em->list,
4473 &em_tree->modified_extents);
4474 write_unlock(&em_tree->lock);
4475 if (err != -EEXIST)
4476 break;
4477 btrfs_drop_extent_cache(inode, cur_offset,
4478 cur_offset +
4479 hole_size - 1, 0);
4480 }
4481 free_extent_map(hole_em);
4482 next:
4483 btrfs_update_inode(trans, root, inode);
4484 btrfs_end_transaction(trans, root);
4485 }
4486 free_extent_map(em);
4487 em = NULL;
4488 cur_offset = last_byte;
4489 if (cur_offset >= block_end)
4490 break;
4491 }
4492
4493 free_extent_map(em);
4494 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4495 GFP_NOFS);
4496 return err;
4497 }
4498
4499 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4500 {
4501 struct btrfs_root *root = BTRFS_I(inode)->root;
4502 struct btrfs_trans_handle *trans;
4503 loff_t oldsize = i_size_read(inode);
4504 loff_t newsize = attr->ia_size;
4505 int mask = attr->ia_valid;
4506 int ret;
4507
4508 if (newsize == oldsize)
4509 return 0;
4510
4511 /*
4512 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4513 * special case where we need to update the times despite not having
4514 * these flags set. For all other operations the VFS set these flags
4515 * explicitly if it wants a timestamp update.
4516 */
4517 if (newsize != oldsize && (!(mask & (ATTR_CTIME | ATTR_MTIME))))
4518 inode->i_ctime = inode->i_mtime = current_fs_time(inode->i_sb);
4519
4520 if (newsize > oldsize) {
4521 truncate_pagecache(inode, oldsize, newsize);
4522 ret = btrfs_cont_expand(inode, oldsize, newsize);
4523 if (ret)
4524 return ret;
4525
4526 trans = btrfs_start_transaction(root, 1);
4527 if (IS_ERR(trans))
4528 return PTR_ERR(trans);
4529
4530 i_size_write(inode, newsize);
4531 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4532 ret = btrfs_update_inode(trans, root, inode);
4533 btrfs_end_transaction(trans, root);
4534 } else {
4535
4536 /*
4537 * We're truncating a file that used to have good data down to
4538 * zero. Make sure it gets into the ordered flush list so that
4539 * any new writes get down to disk quickly.
4540 */
4541 if (newsize == 0)
4542 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
4543 &BTRFS_I(inode)->runtime_flags);
4544
4545 /*
4546 * 1 for the orphan item we're going to add
4547 * 1 for the orphan item deletion.
4548 */
4549 trans = btrfs_start_transaction(root, 2);
4550 if (IS_ERR(trans))
4551 return PTR_ERR(trans);
4552
4553 /*
4554 * We need to do this in case we fail at _any_ point during the
4555 * actual truncate. Once we do the truncate_setsize we could
4556 * invalidate pages which forces any outstanding ordered io to
4557 * be instantly completed which will give us extents that need
4558 * to be truncated. If we fail to get an orphan inode down we
4559 * could have left over extents that were never meant to live,
4560 * so we need to garuntee from this point on that everything
4561 * will be consistent.
4562 */
4563 ret = btrfs_orphan_add(trans, inode);
4564 btrfs_end_transaction(trans, root);
4565 if (ret)
4566 return ret;
4567
4568 /* we don't support swapfiles, so vmtruncate shouldn't fail */
4569 truncate_setsize(inode, newsize);
4570
4571 /* Disable nonlocked read DIO to avoid the end less truncate */
4572 btrfs_inode_block_unlocked_dio(inode);
4573 inode_dio_wait(inode);
4574 btrfs_inode_resume_unlocked_dio(inode);
4575
4576 ret = btrfs_truncate(inode);
4577 if (ret && inode->i_nlink)
4578 btrfs_orphan_del(NULL, inode);
4579 }
4580
4581 return ret;
4582 }
4583
4584 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
4585 {
4586 struct inode *inode = dentry->d_inode;
4587 struct btrfs_root *root = BTRFS_I(inode)->root;
4588 int err;
4589
4590 if (btrfs_root_readonly(root))
4591 return -EROFS;
4592
4593 err = inode_change_ok(inode, attr);
4594 if (err)
4595 return err;
4596
4597 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
4598 err = btrfs_setsize(inode, attr);
4599 if (err)
4600 return err;
4601 }
4602
4603 if (attr->ia_valid) {
4604 setattr_copy(inode, attr);
4605 inode_inc_iversion(inode);
4606 err = btrfs_dirty_inode(inode);
4607
4608 if (!err && attr->ia_valid & ATTR_MODE)
4609 err = btrfs_acl_chmod(inode);
4610 }
4611
4612 return err;
4613 }
4614
4615 void btrfs_evict_inode(struct inode *inode)
4616 {
4617 struct btrfs_trans_handle *trans;
4618 struct btrfs_root *root = BTRFS_I(inode)->root;
4619 struct btrfs_block_rsv *rsv, *global_rsv;
4620 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
4621 int ret;
4622
4623 trace_btrfs_inode_evict(inode);
4624
4625 truncate_inode_pages(&inode->i_data, 0);
4626 if (inode->i_nlink && (btrfs_root_refs(&root->root_item) != 0 ||
4627 btrfs_is_free_space_inode(inode)))
4628 goto no_delete;
4629
4630 if (is_bad_inode(inode)) {
4631 btrfs_orphan_del(NULL, inode);
4632 goto no_delete;
4633 }
4634 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
4635 btrfs_wait_ordered_range(inode, 0, (u64)-1);
4636
4637 if (root->fs_info->log_root_recovering) {
4638 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
4639 &BTRFS_I(inode)->runtime_flags));
4640 goto no_delete;
4641 }
4642
4643 if (inode->i_nlink > 0) {
4644 BUG_ON(btrfs_root_refs(&root->root_item) != 0);
4645 goto no_delete;
4646 }
4647
4648 ret = btrfs_commit_inode_delayed_inode(inode);
4649 if (ret) {
4650 btrfs_orphan_del(NULL, inode);
4651 goto no_delete;
4652 }
4653
4654 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
4655 if (!rsv) {
4656 btrfs_orphan_del(NULL, inode);
4657 goto no_delete;
4658 }
4659 rsv->size = min_size;
4660 rsv->failfast = 1;
4661 global_rsv = &root->fs_info->global_block_rsv;
4662
4663 btrfs_i_size_write(inode, 0);
4664
4665 /*
4666 * This is a bit simpler than btrfs_truncate since we've already
4667 * reserved our space for our orphan item in the unlink, so we just
4668 * need to reserve some slack space in case we add bytes and update
4669 * inode item when doing the truncate.
4670 */
4671 while (1) {
4672 ret = btrfs_block_rsv_refill(root, rsv, min_size,
4673 BTRFS_RESERVE_FLUSH_LIMIT);
4674
4675 /*
4676 * Try and steal from the global reserve since we will
4677 * likely not use this space anyway, we want to try as
4678 * hard as possible to get this to work.
4679 */
4680 if (ret)
4681 ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size);
4682
4683 if (ret) {
4684 btrfs_warn(root->fs_info,
4685 "Could not get space for a delete, will truncate on mount %d",
4686 ret);
4687 btrfs_orphan_del(NULL, inode);
4688 btrfs_free_block_rsv(root, rsv);
4689 goto no_delete;
4690 }
4691
4692 trans = btrfs_join_transaction(root);
4693 if (IS_ERR(trans)) {
4694 btrfs_orphan_del(NULL, inode);
4695 btrfs_free_block_rsv(root, rsv);
4696 goto no_delete;
4697 }
4698
4699 trans->block_rsv = rsv;
4700
4701 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
4702 if (ret != -ENOSPC)
4703 break;
4704
4705 trans->block_rsv = &root->fs_info->trans_block_rsv;
4706 btrfs_end_transaction(trans, root);
4707 trans = NULL;
4708 btrfs_btree_balance_dirty(root);
4709 }
4710
4711 btrfs_free_block_rsv(root, rsv);
4712
4713 if (ret == 0) {
4714 trans->block_rsv = root->orphan_block_rsv;
4715 ret = btrfs_orphan_del(trans, inode);
4716 BUG_ON(ret);
4717 }
4718
4719 trans->block_rsv = &root->fs_info->trans_block_rsv;
4720 if (!(root == root->fs_info->tree_root ||
4721 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
4722 btrfs_return_ino(root, btrfs_ino(inode));
4723
4724 btrfs_end_transaction(trans, root);
4725 btrfs_btree_balance_dirty(root);
4726 no_delete:
4727 clear_inode(inode);
4728 return;
4729 }
4730
4731 /*
4732 * this returns the key found in the dir entry in the location pointer.
4733 * If no dir entries were found, location->objectid is 0.
4734 */
4735 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
4736 struct btrfs_key *location)
4737 {
4738 const char *name = dentry->d_name.name;
4739 int namelen = dentry->d_name.len;
4740 struct btrfs_dir_item *di;
4741 struct btrfs_path *path;
4742 struct btrfs_root *root = BTRFS_I(dir)->root;
4743 int ret = 0;
4744
4745 path = btrfs_alloc_path();
4746 if (!path)
4747 return -ENOMEM;
4748
4749 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
4750 namelen, 0);
4751 if (IS_ERR(di))
4752 ret = PTR_ERR(di);
4753
4754 if (IS_ERR_OR_NULL(di))
4755 goto out_err;
4756
4757 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
4758 out:
4759 btrfs_free_path(path);
4760 return ret;
4761 out_err:
4762 location->objectid = 0;
4763 goto out;
4764 }
4765
4766 /*
4767 * when we hit a tree root in a directory, the btrfs part of the inode
4768 * needs to be changed to reflect the root directory of the tree root. This
4769 * is kind of like crossing a mount point.
4770 */
4771 static int fixup_tree_root_location(struct btrfs_root *root,
4772 struct inode *dir,
4773 struct dentry *dentry,
4774 struct btrfs_key *location,
4775 struct btrfs_root **sub_root)
4776 {
4777 struct btrfs_path *path;
4778 struct btrfs_root *new_root;
4779 struct btrfs_root_ref *ref;
4780 struct extent_buffer *leaf;
4781 int ret;
4782 int err = 0;
4783
4784 path = btrfs_alloc_path();
4785 if (!path) {
4786 err = -ENOMEM;
4787 goto out;
4788 }
4789
4790 err = -ENOENT;
4791 ret = btrfs_find_root_ref(root->fs_info->tree_root, path,
4792 BTRFS_I(dir)->root->root_key.objectid,
4793 location->objectid);
4794 if (ret) {
4795 if (ret < 0)
4796 err = ret;
4797 goto out;
4798 }
4799
4800 leaf = path->nodes[0];
4801 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
4802 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
4803 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
4804 goto out;
4805
4806 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
4807 (unsigned long)(ref + 1),
4808 dentry->d_name.len);
4809 if (ret)
4810 goto out;
4811
4812 btrfs_release_path(path);
4813
4814 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
4815 if (IS_ERR(new_root)) {
4816 err = PTR_ERR(new_root);
4817 goto out;
4818 }
4819
4820 if (btrfs_root_refs(&new_root->root_item) == 0) {
4821 err = -ENOENT;
4822 goto out;
4823 }
4824
4825 *sub_root = new_root;
4826 location->objectid = btrfs_root_dirid(&new_root->root_item);
4827 location->type = BTRFS_INODE_ITEM_KEY;
4828 location->offset = 0;
4829 err = 0;
4830 out:
4831 btrfs_free_path(path);
4832 return err;
4833 }
4834
4835 static void inode_tree_add(struct inode *inode)
4836 {
4837 struct btrfs_root *root = BTRFS_I(inode)->root;
4838 struct btrfs_inode *entry;
4839 struct rb_node **p;
4840 struct rb_node *parent;
4841 u64 ino = btrfs_ino(inode);
4842 again:
4843 p = &root->inode_tree.rb_node;
4844 parent = NULL;
4845
4846 if (inode_unhashed(inode))
4847 return;
4848
4849 spin_lock(&root->inode_lock);
4850 while (*p) {
4851 parent = *p;
4852 entry = rb_entry(parent, struct btrfs_inode, rb_node);
4853
4854 if (ino < btrfs_ino(&entry->vfs_inode))
4855 p = &parent->rb_left;
4856 else if (ino > btrfs_ino(&entry->vfs_inode))
4857 p = &parent->rb_right;
4858 else {
4859 WARN_ON(!(entry->vfs_inode.i_state &
4860 (I_WILL_FREE | I_FREEING)));
4861 rb_erase(parent, &root->inode_tree);
4862 RB_CLEAR_NODE(parent);
4863 spin_unlock(&root->inode_lock);
4864 goto again;
4865 }
4866 }
4867 rb_link_node(&BTRFS_I(inode)->rb_node, parent, p);
4868 rb_insert_color(&BTRFS_I(inode)->rb_node, &root->inode_tree);
4869 spin_unlock(&root->inode_lock);
4870 }
4871
4872 static void inode_tree_del(struct inode *inode)
4873 {
4874 struct btrfs_root *root = BTRFS_I(inode)->root;
4875 int empty = 0;
4876
4877 spin_lock(&root->inode_lock);
4878 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
4879 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
4880 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
4881 empty = RB_EMPTY_ROOT(&root->inode_tree);
4882 }
4883 spin_unlock(&root->inode_lock);
4884
4885 /*
4886 * Free space cache has inodes in the tree root, but the tree root has a
4887 * root_refs of 0, so this could end up dropping the tree root as a
4888 * snapshot, so we need the extra !root->fs_info->tree_root check to
4889 * make sure we don't drop it.
4890 */
4891 if (empty && btrfs_root_refs(&root->root_item) == 0 &&
4892 root != root->fs_info->tree_root) {
4893 synchronize_srcu(&root->fs_info->subvol_srcu);
4894 spin_lock(&root->inode_lock);
4895 empty = RB_EMPTY_ROOT(&root->inode_tree);
4896 spin_unlock(&root->inode_lock);
4897 if (empty)
4898 btrfs_add_dead_root(root);
4899 }
4900 }
4901
4902 void btrfs_invalidate_inodes(struct btrfs_root *root)
4903 {
4904 struct rb_node *node;
4905 struct rb_node *prev;
4906 struct btrfs_inode *entry;
4907 struct inode *inode;
4908 u64 objectid = 0;
4909
4910 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
4911
4912 spin_lock(&root->inode_lock);
4913 again:
4914 node = root->inode_tree.rb_node;
4915 prev = NULL;
4916 while (node) {
4917 prev = node;
4918 entry = rb_entry(node, struct btrfs_inode, rb_node);
4919
4920 if (objectid < btrfs_ino(&entry->vfs_inode))
4921 node = node->rb_left;
4922 else if (objectid > btrfs_ino(&entry->vfs_inode))
4923 node = node->rb_right;
4924 else
4925 break;
4926 }
4927 if (!node) {
4928 while (prev) {
4929 entry = rb_entry(prev, struct btrfs_inode, rb_node);
4930 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
4931 node = prev;
4932 break;
4933 }
4934 prev = rb_next(prev);
4935 }
4936 }
4937 while (node) {
4938 entry = rb_entry(node, struct btrfs_inode, rb_node);
4939 objectid = btrfs_ino(&entry->vfs_inode) + 1;
4940 inode = igrab(&entry->vfs_inode);
4941 if (inode) {
4942 spin_unlock(&root->inode_lock);
4943 if (atomic_read(&inode->i_count) > 1)
4944 d_prune_aliases(inode);
4945 /*
4946 * btrfs_drop_inode will have it removed from
4947 * the inode cache when its usage count
4948 * hits zero.
4949 */
4950 iput(inode);
4951 cond_resched();
4952 spin_lock(&root->inode_lock);
4953 goto again;
4954 }
4955
4956 if (cond_resched_lock(&root->inode_lock))
4957 goto again;
4958
4959 node = rb_next(node);
4960 }
4961 spin_unlock(&root->inode_lock);
4962 }
4963
4964 static int btrfs_init_locked_inode(struct inode *inode, void *p)
4965 {
4966 struct btrfs_iget_args *args = p;
4967 inode->i_ino = args->ino;
4968 BTRFS_I(inode)->root = args->root;
4969 return 0;
4970 }
4971
4972 static int btrfs_find_actor(struct inode *inode, void *opaque)
4973 {
4974 struct btrfs_iget_args *args = opaque;
4975 return args->ino == btrfs_ino(inode) &&
4976 args->root == BTRFS_I(inode)->root;
4977 }
4978
4979 static struct inode *btrfs_iget_locked(struct super_block *s,
4980 u64 objectid,
4981 struct btrfs_root *root)
4982 {
4983 struct inode *inode;
4984 struct btrfs_iget_args args;
4985 args.ino = objectid;
4986 args.root = root;
4987
4988 inode = iget5_locked(s, objectid, btrfs_find_actor,
4989 btrfs_init_locked_inode,
4990 (void *)&args);
4991 return inode;
4992 }
4993
4994 /* Get an inode object given its location and corresponding root.
4995 * Returns in *is_new if the inode was read from disk
4996 */
4997 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
4998 struct btrfs_root *root, int *new)
4999 {
5000 struct inode *inode;
5001
5002 inode = btrfs_iget_locked(s, location->objectid, root);
5003 if (!inode)
5004 return ERR_PTR(-ENOMEM);
5005
5006 if (inode->i_state & I_NEW) {
5007 BTRFS_I(inode)->root = root;
5008 memcpy(&BTRFS_I(inode)->location, location, sizeof(*location));
5009 btrfs_read_locked_inode(inode);
5010 if (!is_bad_inode(inode)) {
5011 inode_tree_add(inode);
5012 unlock_new_inode(inode);
5013 if (new)
5014 *new = 1;
5015 } else {
5016 unlock_new_inode(inode);
5017 iput(inode);
5018 inode = ERR_PTR(-ESTALE);
5019 }
5020 }
5021
5022 return inode;
5023 }
5024
5025 static struct inode *new_simple_dir(struct super_block *s,
5026 struct btrfs_key *key,
5027 struct btrfs_root *root)
5028 {
5029 struct inode *inode = new_inode(s);
5030
5031 if (!inode)
5032 return ERR_PTR(-ENOMEM);
5033
5034 BTRFS_I(inode)->root = root;
5035 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5036 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5037
5038 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5039 inode->i_op = &btrfs_dir_ro_inode_operations;
5040 inode->i_fop = &simple_dir_operations;
5041 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5042 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
5043
5044 return inode;
5045 }
5046
5047 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5048 {
5049 struct inode *inode;
5050 struct btrfs_root *root = BTRFS_I(dir)->root;
5051 struct btrfs_root *sub_root = root;
5052 struct btrfs_key location;
5053 int index;
5054 int ret = 0;
5055
5056 if (dentry->d_name.len > BTRFS_NAME_LEN)
5057 return ERR_PTR(-ENAMETOOLONG);
5058
5059 ret = btrfs_inode_by_name(dir, dentry, &location);
5060 if (ret < 0)
5061 return ERR_PTR(ret);
5062
5063 if (location.objectid == 0)
5064 return NULL;
5065
5066 if (location.type == BTRFS_INODE_ITEM_KEY) {
5067 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5068 return inode;
5069 }
5070
5071 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5072
5073 index = srcu_read_lock(&root->fs_info->subvol_srcu);
5074 ret = fixup_tree_root_location(root, dir, dentry,
5075 &location, &sub_root);
5076 if (ret < 0) {
5077 if (ret != -ENOENT)
5078 inode = ERR_PTR(ret);
5079 else
5080 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5081 } else {
5082 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5083 }
5084 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
5085
5086 if (!IS_ERR(inode) && root != sub_root) {
5087 down_read(&root->fs_info->cleanup_work_sem);
5088 if (!(inode->i_sb->s_flags & MS_RDONLY))
5089 ret = btrfs_orphan_cleanup(sub_root);
5090 up_read(&root->fs_info->cleanup_work_sem);
5091 if (ret)
5092 inode = ERR_PTR(ret);
5093 }
5094
5095 return inode;
5096 }
5097
5098 static int btrfs_dentry_delete(const struct dentry *dentry)
5099 {
5100 struct btrfs_root *root;
5101 struct inode *inode = dentry->d_inode;
5102
5103 if (!inode && !IS_ROOT(dentry))
5104 inode = dentry->d_parent->d_inode;
5105
5106 if (inode) {
5107 root = BTRFS_I(inode)->root;
5108 if (btrfs_root_refs(&root->root_item) == 0)
5109 return 1;
5110
5111 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5112 return 1;
5113 }
5114 return 0;
5115 }
5116
5117 static void btrfs_dentry_release(struct dentry *dentry)
5118 {
5119 if (dentry->d_fsdata)
5120 kfree(dentry->d_fsdata);
5121 }
5122
5123 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5124 unsigned int flags)
5125 {
5126 struct dentry *ret;
5127
5128 ret = d_splice_alias(btrfs_lookup_dentry(dir, dentry), dentry);
5129 return ret;
5130 }
5131
5132 unsigned char btrfs_filetype_table[] = {
5133 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5134 };
5135
5136 static int btrfs_real_readdir(struct file *filp, void *dirent,
5137 filldir_t filldir)
5138 {
5139 struct inode *inode = file_inode(filp);
5140 struct btrfs_root *root = BTRFS_I(inode)->root;
5141 struct btrfs_item *item;
5142 struct btrfs_dir_item *di;
5143 struct btrfs_key key;
5144 struct btrfs_key found_key;
5145 struct btrfs_path *path;
5146 struct list_head ins_list;
5147 struct list_head del_list;
5148 int ret;
5149 struct extent_buffer *leaf;
5150 int slot;
5151 unsigned char d_type;
5152 int over = 0;
5153 u32 di_cur;
5154 u32 di_total;
5155 u32 di_len;
5156 int key_type = BTRFS_DIR_INDEX_KEY;
5157 char tmp_name[32];
5158 char *name_ptr;
5159 int name_len;
5160 int is_curr = 0; /* filp->f_pos points to the current index? */
5161
5162 /* FIXME, use a real flag for deciding about the key type */
5163 if (root->fs_info->tree_root == root)
5164 key_type = BTRFS_DIR_ITEM_KEY;
5165
5166 /* special case for "." */
5167 if (filp->f_pos == 0) {
5168 over = filldir(dirent, ".", 1,
5169 filp->f_pos, btrfs_ino(inode), DT_DIR);
5170 if (over)
5171 return 0;
5172 filp->f_pos = 1;
5173 }
5174 /* special case for .., just use the back ref */
5175 if (filp->f_pos == 1) {
5176 u64 pino = parent_ino(filp->f_path.dentry);
5177 over = filldir(dirent, "..", 2,
5178 filp->f_pos, pino, DT_DIR);
5179 if (over)
5180 return 0;
5181 filp->f_pos = 2;
5182 }
5183 path = btrfs_alloc_path();
5184 if (!path)
5185 return -ENOMEM;
5186
5187 path->reada = 1;
5188
5189 if (key_type == BTRFS_DIR_INDEX_KEY) {
5190 INIT_LIST_HEAD(&ins_list);
5191 INIT_LIST_HEAD(&del_list);
5192 btrfs_get_delayed_items(inode, &ins_list, &del_list);
5193 }
5194
5195 btrfs_set_key_type(&key, key_type);
5196 key.offset = filp->f_pos;
5197 key.objectid = btrfs_ino(inode);
5198
5199 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5200 if (ret < 0)
5201 goto err;
5202
5203 while (1) {
5204 leaf = path->nodes[0];
5205 slot = path->slots[0];
5206 if (slot >= btrfs_header_nritems(leaf)) {
5207 ret = btrfs_next_leaf(root, path);
5208 if (ret < 0)
5209 goto err;
5210 else if (ret > 0)
5211 break;
5212 continue;
5213 }
5214
5215 item = btrfs_item_nr(leaf, slot);
5216 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5217
5218 if (found_key.objectid != key.objectid)
5219 break;
5220 if (btrfs_key_type(&found_key) != key_type)
5221 break;
5222 if (found_key.offset < filp->f_pos)
5223 goto next;
5224 if (key_type == BTRFS_DIR_INDEX_KEY &&
5225 btrfs_should_delete_dir_index(&del_list,
5226 found_key.offset))
5227 goto next;
5228
5229 filp->f_pos = found_key.offset;
5230 is_curr = 1;
5231
5232 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5233 di_cur = 0;
5234 di_total = btrfs_item_size(leaf, item);
5235
5236 while (di_cur < di_total) {
5237 struct btrfs_key location;
5238
5239 if (verify_dir_item(root, leaf, di))
5240 break;
5241
5242 name_len = btrfs_dir_name_len(leaf, di);
5243 if (name_len <= sizeof(tmp_name)) {
5244 name_ptr = tmp_name;
5245 } else {
5246 name_ptr = kmalloc(name_len, GFP_NOFS);
5247 if (!name_ptr) {
5248 ret = -ENOMEM;
5249 goto err;
5250 }
5251 }
5252 read_extent_buffer(leaf, name_ptr,
5253 (unsigned long)(di + 1), name_len);
5254
5255 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5256 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5257
5258
5259 /* is this a reference to our own snapshot? If so
5260 * skip it.
5261 *
5262 * In contrast to old kernels, we insert the snapshot's
5263 * dir item and dir index after it has been created, so
5264 * we won't find a reference to our own snapshot. We
5265 * still keep the following code for backward
5266 * compatibility.
5267 */
5268 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5269 location.objectid == root->root_key.objectid) {
5270 over = 0;
5271 goto skip;
5272 }
5273 over = filldir(dirent, name_ptr, name_len,
5274 found_key.offset, location.objectid,
5275 d_type);
5276
5277 skip:
5278 if (name_ptr != tmp_name)
5279 kfree(name_ptr);
5280
5281 if (over)
5282 goto nopos;
5283 di_len = btrfs_dir_name_len(leaf, di) +
5284 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5285 di_cur += di_len;
5286 di = (struct btrfs_dir_item *)((char *)di + di_len);
5287 }
5288 next:
5289 path->slots[0]++;
5290 }
5291
5292 if (key_type == BTRFS_DIR_INDEX_KEY) {
5293 if (is_curr)
5294 filp->f_pos++;
5295 ret = btrfs_readdir_delayed_dir_index(filp, dirent, filldir,
5296 &ins_list);
5297 if (ret)
5298 goto nopos;
5299 }
5300
5301 /* Reached end of directory/root. Bump pos past the last item. */
5302 if (key_type == BTRFS_DIR_INDEX_KEY)
5303 /*
5304 * 32-bit glibc will use getdents64, but then strtol -
5305 * so the last number we can serve is this.
5306 */
5307 filp->f_pos = 0x7fffffff;
5308 else
5309 filp->f_pos++;
5310 nopos:
5311 ret = 0;
5312 err:
5313 if (key_type == BTRFS_DIR_INDEX_KEY)
5314 btrfs_put_delayed_items(&ins_list, &del_list);
5315 btrfs_free_path(path);
5316 return ret;
5317 }
5318
5319 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5320 {
5321 struct btrfs_root *root = BTRFS_I(inode)->root;
5322 struct btrfs_trans_handle *trans;
5323 int ret = 0;
5324 bool nolock = false;
5325
5326 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5327 return 0;
5328
5329 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5330 nolock = true;
5331
5332 if (wbc->sync_mode == WB_SYNC_ALL) {
5333 if (nolock)
5334 trans = btrfs_join_transaction_nolock(root);
5335 else
5336 trans = btrfs_join_transaction(root);
5337 if (IS_ERR(trans))
5338 return PTR_ERR(trans);
5339 ret = btrfs_commit_transaction(trans, root);
5340 }
5341 return ret;
5342 }
5343
5344 /*
5345 * This is somewhat expensive, updating the tree every time the
5346 * inode changes. But, it is most likely to find the inode in cache.
5347 * FIXME, needs more benchmarking...there are no reasons other than performance
5348 * to keep or drop this code.
5349 */
5350 int btrfs_dirty_inode(struct inode *inode)
5351 {
5352 struct btrfs_root *root = BTRFS_I(inode)->root;
5353 struct btrfs_trans_handle *trans;
5354 int ret;
5355
5356 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5357 return 0;
5358
5359 trans = btrfs_join_transaction(root);
5360 if (IS_ERR(trans))
5361 return PTR_ERR(trans);
5362
5363 ret = btrfs_update_inode(trans, root, inode);
5364 if (ret && ret == -ENOSPC) {
5365 /* whoops, lets try again with the full transaction */
5366 btrfs_end_transaction(trans, root);
5367 trans = btrfs_start_transaction(root, 1);
5368 if (IS_ERR(trans))
5369 return PTR_ERR(trans);
5370
5371 ret = btrfs_update_inode(trans, root, inode);
5372 }
5373 btrfs_end_transaction(trans, root);
5374 if (BTRFS_I(inode)->delayed_node)
5375 btrfs_balance_delayed_items(root);
5376
5377 return ret;
5378 }
5379
5380 /*
5381 * This is a copy of file_update_time. We need this so we can return error on
5382 * ENOSPC for updating the inode in the case of file write and mmap writes.
5383 */
5384 static int btrfs_update_time(struct inode *inode, struct timespec *now,
5385 int flags)
5386 {
5387 struct btrfs_root *root = BTRFS_I(inode)->root;
5388
5389 if (btrfs_root_readonly(root))
5390 return -EROFS;
5391
5392 if (flags & S_VERSION)
5393 inode_inc_iversion(inode);
5394 if (flags & S_CTIME)
5395 inode->i_ctime = *now;
5396 if (flags & S_MTIME)
5397 inode->i_mtime = *now;
5398 if (flags & S_ATIME)
5399 inode->i_atime = *now;
5400 return btrfs_dirty_inode(inode);
5401 }
5402
5403 /*
5404 * find the highest existing sequence number in a directory
5405 * and then set the in-memory index_cnt variable to reflect
5406 * free sequence numbers
5407 */
5408 static int btrfs_set_inode_index_count(struct inode *inode)
5409 {
5410 struct btrfs_root *root = BTRFS_I(inode)->root;
5411 struct btrfs_key key, found_key;
5412 struct btrfs_path *path;
5413 struct extent_buffer *leaf;
5414 int ret;
5415
5416 key.objectid = btrfs_ino(inode);
5417 btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
5418 key.offset = (u64)-1;
5419
5420 path = btrfs_alloc_path();
5421 if (!path)
5422 return -ENOMEM;
5423
5424 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5425 if (ret < 0)
5426 goto out;
5427 /* FIXME: we should be able to handle this */
5428 if (ret == 0)
5429 goto out;
5430 ret = 0;
5431
5432 /*
5433 * MAGIC NUMBER EXPLANATION:
5434 * since we search a directory based on f_pos we have to start at 2
5435 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
5436 * else has to start at 2
5437 */
5438 if (path->slots[0] == 0) {
5439 BTRFS_I(inode)->index_cnt = 2;
5440 goto out;
5441 }
5442
5443 path->slots[0]--;
5444
5445 leaf = path->nodes[0];
5446 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5447
5448 if (found_key.objectid != btrfs_ino(inode) ||
5449 btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) {
5450 BTRFS_I(inode)->index_cnt = 2;
5451 goto out;
5452 }
5453
5454 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
5455 out:
5456 btrfs_free_path(path);
5457 return ret;
5458 }
5459
5460 /*
5461 * helper to find a free sequence number in a given directory. This current
5462 * code is very simple, later versions will do smarter things in the btree
5463 */
5464 int btrfs_set_inode_index(struct inode *dir, u64 *index)
5465 {
5466 int ret = 0;
5467
5468 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
5469 ret = btrfs_inode_delayed_dir_index_count(dir);
5470 if (ret) {
5471 ret = btrfs_set_inode_index_count(dir);
5472 if (ret)
5473 return ret;
5474 }
5475 }
5476
5477 *index = BTRFS_I(dir)->index_cnt;
5478 BTRFS_I(dir)->index_cnt++;
5479
5480 return ret;
5481 }
5482
5483 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
5484 struct btrfs_root *root,
5485 struct inode *dir,
5486 const char *name, int name_len,
5487 u64 ref_objectid, u64 objectid,
5488 umode_t mode, u64 *index)
5489 {
5490 struct inode *inode;
5491 struct btrfs_inode_item *inode_item;
5492 struct btrfs_key *location;
5493 struct btrfs_path *path;
5494 struct btrfs_inode_ref *ref;
5495 struct btrfs_key key[2];
5496 u32 sizes[2];
5497 unsigned long ptr;
5498 int ret;
5499 int owner;
5500
5501 path = btrfs_alloc_path();
5502 if (!path)
5503 return ERR_PTR(-ENOMEM);
5504
5505 inode = new_inode(root->fs_info->sb);
5506 if (!inode) {
5507 btrfs_free_path(path);
5508 return ERR_PTR(-ENOMEM);
5509 }
5510
5511 /*
5512 * we have to initialize this early, so we can reclaim the inode
5513 * number if we fail afterwards in this function.
5514 */
5515 inode->i_ino = objectid;
5516
5517 if (dir) {
5518 trace_btrfs_inode_request(dir);
5519
5520 ret = btrfs_set_inode_index(dir, index);
5521 if (ret) {
5522 btrfs_free_path(path);
5523 iput(inode);
5524 return ERR_PTR(ret);
5525 }
5526 }
5527 /*
5528 * index_cnt is ignored for everything but a dir,
5529 * btrfs_get_inode_index_count has an explanation for the magic
5530 * number
5531 */
5532 BTRFS_I(inode)->index_cnt = 2;
5533 BTRFS_I(inode)->root = root;
5534 BTRFS_I(inode)->generation = trans->transid;
5535 inode->i_generation = BTRFS_I(inode)->generation;
5536
5537 /*
5538 * We could have gotten an inode number from somebody who was fsynced
5539 * and then removed in this same transaction, so let's just set full
5540 * sync since it will be a full sync anyway and this will blow away the
5541 * old info in the log.
5542 */
5543 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
5544
5545 if (S_ISDIR(mode))
5546 owner = 0;
5547 else
5548 owner = 1;
5549
5550 key[0].objectid = objectid;
5551 btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
5552 key[0].offset = 0;
5553
5554 /*
5555 * Start new inodes with an inode_ref. This is slightly more
5556 * efficient for small numbers of hard links since they will
5557 * be packed into one item. Extended refs will kick in if we
5558 * add more hard links than can fit in the ref item.
5559 */
5560 key[1].objectid = objectid;
5561 btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
5562 key[1].offset = ref_objectid;
5563
5564 sizes[0] = sizeof(struct btrfs_inode_item);
5565 sizes[1] = name_len + sizeof(*ref);
5566
5567 path->leave_spinning = 1;
5568 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
5569 if (ret != 0)
5570 goto fail;
5571
5572 inode_init_owner(inode, dir, mode);
5573 inode_set_bytes(inode, 0);
5574 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
5575 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
5576 struct btrfs_inode_item);
5577 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
5578 sizeof(*inode_item));
5579 fill_inode_item(trans, path->nodes[0], inode_item, inode);
5580
5581 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
5582 struct btrfs_inode_ref);
5583 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
5584 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
5585 ptr = (unsigned long)(ref + 1);
5586 write_extent_buffer(path->nodes[0], name, ptr, name_len);
5587
5588 btrfs_mark_buffer_dirty(path->nodes[0]);
5589 btrfs_free_path(path);
5590
5591 location = &BTRFS_I(inode)->location;
5592 location->objectid = objectid;
5593 location->offset = 0;
5594 btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
5595
5596 btrfs_inherit_iflags(inode, dir);
5597
5598 if (S_ISREG(mode)) {
5599 if (btrfs_test_opt(root, NODATASUM))
5600 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
5601 if (btrfs_test_opt(root, NODATACOW))
5602 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
5603 BTRFS_INODE_NODATASUM;
5604 }
5605
5606 insert_inode_hash(inode);
5607 inode_tree_add(inode);
5608
5609 trace_btrfs_inode_new(inode);
5610 btrfs_set_inode_last_trans(trans, inode);
5611
5612 btrfs_update_root_times(trans, root);
5613
5614 return inode;
5615 fail:
5616 if (dir)
5617 BTRFS_I(dir)->index_cnt--;
5618 btrfs_free_path(path);
5619 iput(inode);
5620 return ERR_PTR(ret);
5621 }
5622
5623 static inline u8 btrfs_inode_type(struct inode *inode)
5624 {
5625 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
5626 }
5627
5628 /*
5629 * utility function to add 'inode' into 'parent_inode' with
5630 * a give name and a given sequence number.
5631 * if 'add_backref' is true, also insert a backref from the
5632 * inode to the parent directory.
5633 */
5634 int btrfs_add_link(struct btrfs_trans_handle *trans,
5635 struct inode *parent_inode, struct inode *inode,
5636 const char *name, int name_len, int add_backref, u64 index)
5637 {
5638 int ret = 0;
5639 struct btrfs_key key;
5640 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
5641 u64 ino = btrfs_ino(inode);
5642 u64 parent_ino = btrfs_ino(parent_inode);
5643
5644 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5645 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
5646 } else {
5647 key.objectid = ino;
5648 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
5649 key.offset = 0;
5650 }
5651
5652 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5653 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
5654 key.objectid, root->root_key.objectid,
5655 parent_ino, index, name, name_len);
5656 } else if (add_backref) {
5657 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
5658 parent_ino, index);
5659 }
5660
5661 /* Nothing to clean up yet */
5662 if (ret)
5663 return ret;
5664
5665 ret = btrfs_insert_dir_item(trans, root, name, name_len,
5666 parent_inode, &key,
5667 btrfs_inode_type(inode), index);
5668 if (ret == -EEXIST || ret == -EOVERFLOW)
5669 goto fail_dir_item;
5670 else if (ret) {
5671 btrfs_abort_transaction(trans, root, ret);
5672 return ret;
5673 }
5674
5675 btrfs_i_size_write(parent_inode, parent_inode->i_size +
5676 name_len * 2);
5677 inode_inc_iversion(parent_inode);
5678 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
5679 ret = btrfs_update_inode(trans, root, parent_inode);
5680 if (ret)
5681 btrfs_abort_transaction(trans, root, ret);
5682 return ret;
5683
5684 fail_dir_item:
5685 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
5686 u64 local_index;
5687 int err;
5688 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
5689 key.objectid, root->root_key.objectid,
5690 parent_ino, &local_index, name, name_len);
5691
5692 } else if (add_backref) {
5693 u64 local_index;
5694 int err;
5695
5696 err = btrfs_del_inode_ref(trans, root, name, name_len,
5697 ino, parent_ino, &local_index);
5698 }
5699 return ret;
5700 }
5701
5702 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
5703 struct inode *dir, struct dentry *dentry,
5704 struct inode *inode, int backref, u64 index)
5705 {
5706 int err = btrfs_add_link(trans, dir, inode,
5707 dentry->d_name.name, dentry->d_name.len,
5708 backref, index);
5709 if (err > 0)
5710 err = -EEXIST;
5711 return err;
5712 }
5713
5714 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
5715 umode_t mode, dev_t rdev)
5716 {
5717 struct btrfs_trans_handle *trans;
5718 struct btrfs_root *root = BTRFS_I(dir)->root;
5719 struct inode *inode = NULL;
5720 int err;
5721 int drop_inode = 0;
5722 u64 objectid;
5723 u64 index = 0;
5724
5725 if (!new_valid_dev(rdev))
5726 return -EINVAL;
5727
5728 /*
5729 * 2 for inode item and ref
5730 * 2 for dir items
5731 * 1 for xattr if selinux is on
5732 */
5733 trans = btrfs_start_transaction(root, 5);
5734 if (IS_ERR(trans))
5735 return PTR_ERR(trans);
5736
5737 err = btrfs_find_free_ino(root, &objectid);
5738 if (err)
5739 goto out_unlock;
5740
5741 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5742 dentry->d_name.len, btrfs_ino(dir), objectid,
5743 mode, &index);
5744 if (IS_ERR(inode)) {
5745 err = PTR_ERR(inode);
5746 goto out_unlock;
5747 }
5748
5749 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5750 if (err) {
5751 drop_inode = 1;
5752 goto out_unlock;
5753 }
5754
5755 /*
5756 * If the active LSM wants to access the inode during
5757 * d_instantiate it needs these. Smack checks to see
5758 * if the filesystem supports xattrs by looking at the
5759 * ops vector.
5760 */
5761
5762 inode->i_op = &btrfs_special_inode_operations;
5763 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5764 if (err)
5765 drop_inode = 1;
5766 else {
5767 init_special_inode(inode, inode->i_mode, rdev);
5768 btrfs_update_inode(trans, root, inode);
5769 d_instantiate(dentry, inode);
5770 }
5771 out_unlock:
5772 btrfs_end_transaction(trans, root);
5773 btrfs_btree_balance_dirty(root);
5774 if (drop_inode) {
5775 inode_dec_link_count(inode);
5776 iput(inode);
5777 }
5778 return err;
5779 }
5780
5781 static int btrfs_create(struct inode *dir, struct dentry *dentry,
5782 umode_t mode, bool excl)
5783 {
5784 struct btrfs_trans_handle *trans;
5785 struct btrfs_root *root = BTRFS_I(dir)->root;
5786 struct inode *inode = NULL;
5787 int drop_inode_on_err = 0;
5788 int err;
5789 u64 objectid;
5790 u64 index = 0;
5791
5792 /*
5793 * 2 for inode item and ref
5794 * 2 for dir items
5795 * 1 for xattr if selinux is on
5796 */
5797 trans = btrfs_start_transaction(root, 5);
5798 if (IS_ERR(trans))
5799 return PTR_ERR(trans);
5800
5801 err = btrfs_find_free_ino(root, &objectid);
5802 if (err)
5803 goto out_unlock;
5804
5805 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5806 dentry->d_name.len, btrfs_ino(dir), objectid,
5807 mode, &index);
5808 if (IS_ERR(inode)) {
5809 err = PTR_ERR(inode);
5810 goto out_unlock;
5811 }
5812 drop_inode_on_err = 1;
5813
5814 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5815 if (err)
5816 goto out_unlock;
5817
5818 err = btrfs_update_inode(trans, root, inode);
5819 if (err)
5820 goto out_unlock;
5821
5822 /*
5823 * If the active LSM wants to access the inode during
5824 * d_instantiate it needs these. Smack checks to see
5825 * if the filesystem supports xattrs by looking at the
5826 * ops vector.
5827 */
5828 inode->i_fop = &btrfs_file_operations;
5829 inode->i_op = &btrfs_file_inode_operations;
5830
5831 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
5832 if (err)
5833 goto out_unlock;
5834
5835 inode->i_mapping->a_ops = &btrfs_aops;
5836 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
5837 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
5838 d_instantiate(dentry, inode);
5839
5840 out_unlock:
5841 btrfs_end_transaction(trans, root);
5842 if (err && drop_inode_on_err) {
5843 inode_dec_link_count(inode);
5844 iput(inode);
5845 }
5846 btrfs_btree_balance_dirty(root);
5847 return err;
5848 }
5849
5850 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
5851 struct dentry *dentry)
5852 {
5853 struct btrfs_trans_handle *trans;
5854 struct btrfs_root *root = BTRFS_I(dir)->root;
5855 struct inode *inode = old_dentry->d_inode;
5856 u64 index;
5857 int err;
5858 int drop_inode = 0;
5859
5860 /* do not allow sys_link's with other subvols of the same device */
5861 if (root->objectid != BTRFS_I(inode)->root->objectid)
5862 return -EXDEV;
5863
5864 if (inode->i_nlink >= BTRFS_LINK_MAX)
5865 return -EMLINK;
5866
5867 err = btrfs_set_inode_index(dir, &index);
5868 if (err)
5869 goto fail;
5870
5871 /*
5872 * 2 items for inode and inode ref
5873 * 2 items for dir items
5874 * 1 item for parent inode
5875 */
5876 trans = btrfs_start_transaction(root, 5);
5877 if (IS_ERR(trans)) {
5878 err = PTR_ERR(trans);
5879 goto fail;
5880 }
5881
5882 btrfs_inc_nlink(inode);
5883 inode_inc_iversion(inode);
5884 inode->i_ctime = CURRENT_TIME;
5885 ihold(inode);
5886 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
5887
5888 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
5889
5890 if (err) {
5891 drop_inode = 1;
5892 } else {
5893 struct dentry *parent = dentry->d_parent;
5894 err = btrfs_update_inode(trans, root, inode);
5895 if (err)
5896 goto fail;
5897 d_instantiate(dentry, inode);
5898 btrfs_log_new_name(trans, inode, NULL, parent);
5899 }
5900
5901 btrfs_end_transaction(trans, root);
5902 fail:
5903 if (drop_inode) {
5904 inode_dec_link_count(inode);
5905 iput(inode);
5906 }
5907 btrfs_btree_balance_dirty(root);
5908 return err;
5909 }
5910
5911 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
5912 {
5913 struct inode *inode = NULL;
5914 struct btrfs_trans_handle *trans;
5915 struct btrfs_root *root = BTRFS_I(dir)->root;
5916 int err = 0;
5917 int drop_on_err = 0;
5918 u64 objectid = 0;
5919 u64 index = 0;
5920
5921 /*
5922 * 2 items for inode and ref
5923 * 2 items for dir items
5924 * 1 for xattr if selinux is on
5925 */
5926 trans = btrfs_start_transaction(root, 5);
5927 if (IS_ERR(trans))
5928 return PTR_ERR(trans);
5929
5930 err = btrfs_find_free_ino(root, &objectid);
5931 if (err)
5932 goto out_fail;
5933
5934 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5935 dentry->d_name.len, btrfs_ino(dir), objectid,
5936 S_IFDIR | mode, &index);
5937 if (IS_ERR(inode)) {
5938 err = PTR_ERR(inode);
5939 goto out_fail;
5940 }
5941
5942 drop_on_err = 1;
5943
5944 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5945 if (err)
5946 goto out_fail;
5947
5948 inode->i_op = &btrfs_dir_inode_operations;
5949 inode->i_fop = &btrfs_dir_file_operations;
5950
5951 btrfs_i_size_write(inode, 0);
5952 err = btrfs_update_inode(trans, root, inode);
5953 if (err)
5954 goto out_fail;
5955
5956 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
5957 dentry->d_name.len, 0, index);
5958 if (err)
5959 goto out_fail;
5960
5961 d_instantiate(dentry, inode);
5962 drop_on_err = 0;
5963
5964 out_fail:
5965 btrfs_end_transaction(trans, root);
5966 if (drop_on_err)
5967 iput(inode);
5968 btrfs_btree_balance_dirty(root);
5969 return err;
5970 }
5971
5972 /* helper for btfs_get_extent. Given an existing extent in the tree,
5973 * and an extent that you want to insert, deal with overlap and insert
5974 * the new extent into the tree.
5975 */
5976 static int merge_extent_mapping(struct extent_map_tree *em_tree,
5977 struct extent_map *existing,
5978 struct extent_map *em,
5979 u64 map_start, u64 map_len)
5980 {
5981 u64 start_diff;
5982
5983 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
5984 start_diff = map_start - em->start;
5985 em->start = map_start;
5986 em->len = map_len;
5987 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
5988 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
5989 em->block_start += start_diff;
5990 em->block_len -= start_diff;
5991 }
5992 return add_extent_mapping(em_tree, em);
5993 }
5994
5995 static noinline int uncompress_inline(struct btrfs_path *path,
5996 struct inode *inode, struct page *page,
5997 size_t pg_offset, u64 extent_offset,
5998 struct btrfs_file_extent_item *item)
5999 {
6000 int ret;
6001 struct extent_buffer *leaf = path->nodes[0];
6002 char *tmp;
6003 size_t max_size;
6004 unsigned long inline_size;
6005 unsigned long ptr;
6006 int compress_type;
6007
6008 WARN_ON(pg_offset != 0);
6009 compress_type = btrfs_file_extent_compression(leaf, item);
6010 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6011 inline_size = btrfs_file_extent_inline_item_len(leaf,
6012 btrfs_item_nr(leaf, path->slots[0]));
6013 tmp = kmalloc(inline_size, GFP_NOFS);
6014 if (!tmp)
6015 return -ENOMEM;
6016 ptr = btrfs_file_extent_inline_start(item);
6017
6018 read_extent_buffer(leaf, tmp, ptr, inline_size);
6019
6020 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
6021 ret = btrfs_decompress(compress_type, tmp, page,
6022 extent_offset, inline_size, max_size);
6023 if (ret) {
6024 char *kaddr = kmap_atomic(page);
6025 unsigned long copy_size = min_t(u64,
6026 PAGE_CACHE_SIZE - pg_offset,
6027 max_size - extent_offset);
6028 memset(kaddr + pg_offset, 0, copy_size);
6029 kunmap_atomic(kaddr);
6030 }
6031 kfree(tmp);
6032 return 0;
6033 }
6034
6035 /*
6036 * a bit scary, this does extent mapping from logical file offset to the disk.
6037 * the ugly parts come from merging extents from the disk with the in-ram
6038 * representation. This gets more complex because of the data=ordered code,
6039 * where the in-ram extents might be locked pending data=ordered completion.
6040 *
6041 * This also copies inline extents directly into the page.
6042 */
6043
6044 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
6045 size_t pg_offset, u64 start, u64 len,
6046 int create)
6047 {
6048 int ret;
6049 int err = 0;
6050 u64 bytenr;
6051 u64 extent_start = 0;
6052 u64 extent_end = 0;
6053 u64 objectid = btrfs_ino(inode);
6054 u32 found_type;
6055 struct btrfs_path *path = NULL;
6056 struct btrfs_root *root = BTRFS_I(inode)->root;
6057 struct btrfs_file_extent_item *item;
6058 struct extent_buffer *leaf;
6059 struct btrfs_key found_key;
6060 struct extent_map *em = NULL;
6061 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
6062 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6063 struct btrfs_trans_handle *trans = NULL;
6064 int compress_type;
6065
6066 again:
6067 read_lock(&em_tree->lock);
6068 em = lookup_extent_mapping(em_tree, start, len);
6069 if (em)
6070 em->bdev = root->fs_info->fs_devices->latest_bdev;
6071 read_unlock(&em_tree->lock);
6072
6073 if (em) {
6074 if (em->start > start || em->start + em->len <= start)
6075 free_extent_map(em);
6076 else if (em->block_start == EXTENT_MAP_INLINE && page)
6077 free_extent_map(em);
6078 else
6079 goto out;
6080 }
6081 em = alloc_extent_map();
6082 if (!em) {
6083 err = -ENOMEM;
6084 goto out;
6085 }
6086 em->bdev = root->fs_info->fs_devices->latest_bdev;
6087 em->start = EXTENT_MAP_HOLE;
6088 em->orig_start = EXTENT_MAP_HOLE;
6089 em->len = (u64)-1;
6090 em->block_len = (u64)-1;
6091
6092 if (!path) {
6093 path = btrfs_alloc_path();
6094 if (!path) {
6095 err = -ENOMEM;
6096 goto out;
6097 }
6098 /*
6099 * Chances are we'll be called again, so go ahead and do
6100 * readahead
6101 */
6102 path->reada = 1;
6103 }
6104
6105 ret = btrfs_lookup_file_extent(trans, root, path,
6106 objectid, start, trans != NULL);
6107 if (ret < 0) {
6108 err = ret;
6109 goto out;
6110 }
6111
6112 if (ret != 0) {
6113 if (path->slots[0] == 0)
6114 goto not_found;
6115 path->slots[0]--;
6116 }
6117
6118 leaf = path->nodes[0];
6119 item = btrfs_item_ptr(leaf, path->slots[0],
6120 struct btrfs_file_extent_item);
6121 /* are we inside the extent that was found? */
6122 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6123 found_type = btrfs_key_type(&found_key);
6124 if (found_key.objectid != objectid ||
6125 found_type != BTRFS_EXTENT_DATA_KEY) {
6126 goto not_found;
6127 }
6128
6129 found_type = btrfs_file_extent_type(leaf, item);
6130 extent_start = found_key.offset;
6131 compress_type = btrfs_file_extent_compression(leaf, item);
6132 if (found_type == BTRFS_FILE_EXTENT_REG ||
6133 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6134 extent_end = extent_start +
6135 btrfs_file_extent_num_bytes(leaf, item);
6136 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6137 size_t size;
6138 size = btrfs_file_extent_inline_len(leaf, item);
6139 extent_end = ALIGN(extent_start + size, root->sectorsize);
6140 }
6141
6142 if (start >= extent_end) {
6143 path->slots[0]++;
6144 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6145 ret = btrfs_next_leaf(root, path);
6146 if (ret < 0) {
6147 err = ret;
6148 goto out;
6149 }
6150 if (ret > 0)
6151 goto not_found;
6152 leaf = path->nodes[0];
6153 }
6154 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6155 if (found_key.objectid != objectid ||
6156 found_key.type != BTRFS_EXTENT_DATA_KEY)
6157 goto not_found;
6158 if (start + len <= found_key.offset)
6159 goto not_found;
6160 em->start = start;
6161 em->orig_start = start;
6162 em->len = found_key.offset - start;
6163 goto not_found_em;
6164 }
6165
6166 em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, item);
6167 if (found_type == BTRFS_FILE_EXTENT_REG ||
6168 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6169 em->start = extent_start;
6170 em->len = extent_end - extent_start;
6171 em->orig_start = extent_start -
6172 btrfs_file_extent_offset(leaf, item);
6173 em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf,
6174 item);
6175 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
6176 if (bytenr == 0) {
6177 em->block_start = EXTENT_MAP_HOLE;
6178 goto insert;
6179 }
6180 if (compress_type != BTRFS_COMPRESS_NONE) {
6181 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
6182 em->compress_type = compress_type;
6183 em->block_start = bytenr;
6184 em->block_len = em->orig_block_len;
6185 } else {
6186 bytenr += btrfs_file_extent_offset(leaf, item);
6187 em->block_start = bytenr;
6188 em->block_len = em->len;
6189 if (found_type == BTRFS_FILE_EXTENT_PREALLOC)
6190 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
6191 }
6192 goto insert;
6193 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6194 unsigned long ptr;
6195 char *map;
6196 size_t size;
6197 size_t extent_offset;
6198 size_t copy_size;
6199
6200 em->block_start = EXTENT_MAP_INLINE;
6201 if (!page || create) {
6202 em->start = extent_start;
6203 em->len = extent_end - extent_start;
6204 goto out;
6205 }
6206
6207 size = btrfs_file_extent_inline_len(leaf, item);
6208 extent_offset = page_offset(page) + pg_offset - extent_start;
6209 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
6210 size - extent_offset);
6211 em->start = extent_start + extent_offset;
6212 em->len = ALIGN(copy_size, root->sectorsize);
6213 em->orig_block_len = em->len;
6214 em->orig_start = em->start;
6215 if (compress_type) {
6216 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
6217 em->compress_type = compress_type;
6218 }
6219 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6220 if (create == 0 && !PageUptodate(page)) {
6221 if (btrfs_file_extent_compression(leaf, item) !=
6222 BTRFS_COMPRESS_NONE) {
6223 ret = uncompress_inline(path, inode, page,
6224 pg_offset,
6225 extent_offset, item);
6226 BUG_ON(ret); /* -ENOMEM */
6227 } else {
6228 map = kmap(page);
6229 read_extent_buffer(leaf, map + pg_offset, ptr,
6230 copy_size);
6231 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
6232 memset(map + pg_offset + copy_size, 0,
6233 PAGE_CACHE_SIZE - pg_offset -
6234 copy_size);
6235 }
6236 kunmap(page);
6237 }
6238 flush_dcache_page(page);
6239 } else if (create && PageUptodate(page)) {
6240 BUG();
6241 if (!trans) {
6242 kunmap(page);
6243 free_extent_map(em);
6244 em = NULL;
6245
6246 btrfs_release_path(path);
6247 trans = btrfs_join_transaction(root);
6248
6249 if (IS_ERR(trans))
6250 return ERR_CAST(trans);
6251 goto again;
6252 }
6253 map = kmap(page);
6254 write_extent_buffer(leaf, map + pg_offset, ptr,
6255 copy_size);
6256 kunmap(page);
6257 btrfs_mark_buffer_dirty(leaf);
6258 }
6259 set_extent_uptodate(io_tree, em->start,
6260 extent_map_end(em) - 1, NULL, GFP_NOFS);
6261 goto insert;
6262 } else {
6263 WARN(1, KERN_ERR "btrfs unknown found_type %d\n", found_type);
6264 }
6265 not_found:
6266 em->start = start;
6267 em->orig_start = start;
6268 em->len = len;
6269 not_found_em:
6270 em->block_start = EXTENT_MAP_HOLE;
6271 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
6272 insert:
6273 btrfs_release_path(path);
6274 if (em->start > start || extent_map_end(em) <= start) {
6275 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
6276 (unsigned long long)em->start,
6277 (unsigned long long)em->len,
6278 (unsigned long long)start,
6279 (unsigned long long)len);
6280 err = -EIO;
6281 goto out;
6282 }
6283
6284 err = 0;
6285 write_lock(&em_tree->lock);
6286 ret = add_extent_mapping(em_tree, em);
6287 /* it is possible that someone inserted the extent into the tree
6288 * while we had the lock dropped. It is also possible that
6289 * an overlapping map exists in the tree
6290 */
6291 if (ret == -EEXIST) {
6292 struct extent_map *existing;
6293
6294 ret = 0;
6295
6296 existing = lookup_extent_mapping(em_tree, start, len);
6297 if (existing && (existing->start > start ||
6298 existing->start + existing->len <= start)) {
6299 free_extent_map(existing);
6300 existing = NULL;
6301 }
6302 if (!existing) {
6303 existing = lookup_extent_mapping(em_tree, em->start,
6304 em->len);
6305 if (existing) {
6306 err = merge_extent_mapping(em_tree, existing,
6307 em, start,
6308 root->sectorsize);
6309 free_extent_map(existing);
6310 if (err) {
6311 free_extent_map(em);
6312 em = NULL;
6313 }
6314 } else {
6315 err = -EIO;
6316 free_extent_map(em);
6317 em = NULL;
6318 }
6319 } else {
6320 free_extent_map(em);
6321 em = existing;
6322 err = 0;
6323 }
6324 }
6325 write_unlock(&em_tree->lock);
6326 out:
6327
6328 if (em)
6329 trace_btrfs_get_extent(root, em);
6330
6331 if (path)
6332 btrfs_free_path(path);
6333 if (trans) {
6334 ret = btrfs_end_transaction(trans, root);
6335 if (!err)
6336 err = ret;
6337 }
6338 if (err) {
6339 free_extent_map(em);
6340 return ERR_PTR(err);
6341 }
6342 BUG_ON(!em); /* Error is always set */
6343 return em;
6344 }
6345
6346 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
6347 size_t pg_offset, u64 start, u64 len,
6348 int create)
6349 {
6350 struct extent_map *em;
6351 struct extent_map *hole_em = NULL;
6352 u64 range_start = start;
6353 u64 end;
6354 u64 found;
6355 u64 found_end;
6356 int err = 0;
6357
6358 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
6359 if (IS_ERR(em))
6360 return em;
6361 if (em) {
6362 /*
6363 * if our em maps to
6364 * - a hole or
6365 * - a pre-alloc extent,
6366 * there might actually be delalloc bytes behind it.
6367 */
6368 if (em->block_start != EXTENT_MAP_HOLE &&
6369 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6370 return em;
6371 else
6372 hole_em = em;
6373 }
6374
6375 /* check to see if we've wrapped (len == -1 or similar) */
6376 end = start + len;
6377 if (end < start)
6378 end = (u64)-1;
6379 else
6380 end -= 1;
6381
6382 em = NULL;
6383
6384 /* ok, we didn't find anything, lets look for delalloc */
6385 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
6386 end, len, EXTENT_DELALLOC, 1);
6387 found_end = range_start + found;
6388 if (found_end < range_start)
6389 found_end = (u64)-1;
6390
6391 /*
6392 * we didn't find anything useful, return
6393 * the original results from get_extent()
6394 */
6395 if (range_start > end || found_end <= start) {
6396 em = hole_em;
6397 hole_em = NULL;
6398 goto out;
6399 }
6400
6401 /* adjust the range_start to make sure it doesn't
6402 * go backwards from the start they passed in
6403 */
6404 range_start = max(start,range_start);
6405 found = found_end - range_start;
6406
6407 if (found > 0) {
6408 u64 hole_start = start;
6409 u64 hole_len = len;
6410
6411 em = alloc_extent_map();
6412 if (!em) {
6413 err = -ENOMEM;
6414 goto out;
6415 }
6416 /*
6417 * when btrfs_get_extent can't find anything it
6418 * returns one huge hole
6419 *
6420 * make sure what it found really fits our range, and
6421 * adjust to make sure it is based on the start from
6422 * the caller
6423 */
6424 if (hole_em) {
6425 u64 calc_end = extent_map_end(hole_em);
6426
6427 if (calc_end <= start || (hole_em->start > end)) {
6428 free_extent_map(hole_em);
6429 hole_em = NULL;
6430 } else {
6431 hole_start = max(hole_em->start, start);
6432 hole_len = calc_end - hole_start;
6433 }
6434 }
6435 em->bdev = NULL;
6436 if (hole_em && range_start > hole_start) {
6437 /* our hole starts before our delalloc, so we
6438 * have to return just the parts of the hole
6439 * that go until the delalloc starts
6440 */
6441 em->len = min(hole_len,
6442 range_start - hole_start);
6443 em->start = hole_start;
6444 em->orig_start = hole_start;
6445 /*
6446 * don't adjust block start at all,
6447 * it is fixed at EXTENT_MAP_HOLE
6448 */
6449 em->block_start = hole_em->block_start;
6450 em->block_len = hole_len;
6451 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
6452 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
6453 } else {
6454 em->start = range_start;
6455 em->len = found;
6456 em->orig_start = range_start;
6457 em->block_start = EXTENT_MAP_DELALLOC;
6458 em->block_len = found;
6459 }
6460 } else if (hole_em) {
6461 return hole_em;
6462 }
6463 out:
6464
6465 free_extent_map(hole_em);
6466 if (err) {
6467 free_extent_map(em);
6468 return ERR_PTR(err);
6469 }
6470 return em;
6471 }
6472
6473 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
6474 u64 start, u64 len)
6475 {
6476 struct btrfs_root *root = BTRFS_I(inode)->root;
6477 struct btrfs_trans_handle *trans;
6478 struct extent_map *em;
6479 struct btrfs_key ins;
6480 u64 alloc_hint;
6481 int ret;
6482
6483 trans = btrfs_join_transaction(root);
6484 if (IS_ERR(trans))
6485 return ERR_CAST(trans);
6486
6487 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
6488
6489 alloc_hint = get_extent_allocation_hint(inode, start, len);
6490 ret = btrfs_reserve_extent(trans, root, len, root->sectorsize, 0,
6491 alloc_hint, &ins, 1);
6492 if (ret) {
6493 em = ERR_PTR(ret);
6494 goto out;
6495 }
6496
6497 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
6498 ins.offset, ins.offset, ins.offset, 0);
6499 if (IS_ERR(em))
6500 goto out;
6501
6502 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
6503 ins.offset, ins.offset, 0);
6504 if (ret) {
6505 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
6506 em = ERR_PTR(ret);
6507 }
6508 out:
6509 btrfs_end_transaction(trans, root);
6510 return em;
6511 }
6512
6513 /*
6514 * returns 1 when the nocow is safe, < 1 on error, 0 if the
6515 * block must be cow'd
6516 */
6517 static noinline int can_nocow_odirect(struct btrfs_trans_handle *trans,
6518 struct inode *inode, u64 offset, u64 len)
6519 {
6520 struct btrfs_path *path;
6521 int ret;
6522 struct extent_buffer *leaf;
6523 struct btrfs_root *root = BTRFS_I(inode)->root;
6524 struct btrfs_file_extent_item *fi;
6525 struct btrfs_key key;
6526 u64 disk_bytenr;
6527 u64 backref_offset;
6528 u64 extent_end;
6529 u64 num_bytes;
6530 int slot;
6531 int found_type;
6532
6533 path = btrfs_alloc_path();
6534 if (!path)
6535 return -ENOMEM;
6536
6537 ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(inode),
6538 offset, 0);
6539 if (ret < 0)
6540 goto out;
6541
6542 slot = path->slots[0];
6543 if (ret == 1) {
6544 if (slot == 0) {
6545 /* can't find the item, must cow */
6546 ret = 0;
6547 goto out;
6548 }
6549 slot--;
6550 }
6551 ret = 0;
6552 leaf = path->nodes[0];
6553 btrfs_item_key_to_cpu(leaf, &key, slot);
6554 if (key.objectid != btrfs_ino(inode) ||
6555 key.type != BTRFS_EXTENT_DATA_KEY) {
6556 /* not our file or wrong item type, must cow */
6557 goto out;
6558 }
6559
6560 if (key.offset > offset) {
6561 /* Wrong offset, must cow */
6562 goto out;
6563 }
6564
6565 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
6566 found_type = btrfs_file_extent_type(leaf, fi);
6567 if (found_type != BTRFS_FILE_EXTENT_REG &&
6568 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
6569 /* not a regular extent, must cow */
6570 goto out;
6571 }
6572 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
6573 backref_offset = btrfs_file_extent_offset(leaf, fi);
6574
6575 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
6576 if (extent_end < offset + len) {
6577 /* extent doesn't include our full range, must cow */
6578 goto out;
6579 }
6580
6581 if (btrfs_extent_readonly(root, disk_bytenr))
6582 goto out;
6583
6584 /*
6585 * look for other files referencing this extent, if we
6586 * find any we must cow
6587 */
6588 if (btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
6589 key.offset - backref_offset, disk_bytenr))
6590 goto out;
6591
6592 /*
6593 * adjust disk_bytenr and num_bytes to cover just the bytes
6594 * in this extent we are about to write. If there
6595 * are any csums in that range we have to cow in order
6596 * to keep the csums correct
6597 */
6598 disk_bytenr += backref_offset;
6599 disk_bytenr += offset - key.offset;
6600 num_bytes = min(offset + len, extent_end) - offset;
6601 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
6602 goto out;
6603 /*
6604 * all of the above have passed, it is safe to overwrite this extent
6605 * without cow
6606 */
6607 ret = 1;
6608 out:
6609 btrfs_free_path(path);
6610 return ret;
6611 }
6612
6613 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
6614 struct extent_state **cached_state, int writing)
6615 {
6616 struct btrfs_ordered_extent *ordered;
6617 int ret = 0;
6618
6619 while (1) {
6620 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6621 0, cached_state);
6622 /*
6623 * We're concerned with the entire range that we're going to be
6624 * doing DIO to, so we need to make sure theres no ordered
6625 * extents in this range.
6626 */
6627 ordered = btrfs_lookup_ordered_range(inode, lockstart,
6628 lockend - lockstart + 1);
6629
6630 /*
6631 * We need to make sure there are no buffered pages in this
6632 * range either, we could have raced between the invalidate in
6633 * generic_file_direct_write and locking the extent. The
6634 * invalidate needs to happen so that reads after a write do not
6635 * get stale data.
6636 */
6637 if (!ordered && (!writing ||
6638 !test_range_bit(&BTRFS_I(inode)->io_tree,
6639 lockstart, lockend, EXTENT_UPTODATE, 0,
6640 *cached_state)))
6641 break;
6642
6643 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6644 cached_state, GFP_NOFS);
6645
6646 if (ordered) {
6647 btrfs_start_ordered_extent(inode, ordered, 1);
6648 btrfs_put_ordered_extent(ordered);
6649 } else {
6650 /* Screw you mmap */
6651 ret = filemap_write_and_wait_range(inode->i_mapping,
6652 lockstart,
6653 lockend);
6654 if (ret)
6655 break;
6656
6657 /*
6658 * If we found a page that couldn't be invalidated just
6659 * fall back to buffered.
6660 */
6661 ret = invalidate_inode_pages2_range(inode->i_mapping,
6662 lockstart >> PAGE_CACHE_SHIFT,
6663 lockend >> PAGE_CACHE_SHIFT);
6664 if (ret)
6665 break;
6666 }
6667
6668 cond_resched();
6669 }
6670
6671 return ret;
6672 }
6673
6674 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
6675 u64 len, u64 orig_start,
6676 u64 block_start, u64 block_len,
6677 u64 orig_block_len, u64 ram_bytes,
6678 int type)
6679 {
6680 struct extent_map_tree *em_tree;
6681 struct extent_map *em;
6682 struct btrfs_root *root = BTRFS_I(inode)->root;
6683 int ret;
6684
6685 em_tree = &BTRFS_I(inode)->extent_tree;
6686 em = alloc_extent_map();
6687 if (!em)
6688 return ERR_PTR(-ENOMEM);
6689
6690 em->start = start;
6691 em->orig_start = orig_start;
6692 em->mod_start = start;
6693 em->mod_len = len;
6694 em->len = len;
6695 em->block_len = block_len;
6696 em->block_start = block_start;
6697 em->bdev = root->fs_info->fs_devices->latest_bdev;
6698 em->orig_block_len = orig_block_len;
6699 em->ram_bytes = ram_bytes;
6700 em->generation = -1;
6701 set_bit(EXTENT_FLAG_PINNED, &em->flags);
6702 if (type == BTRFS_ORDERED_PREALLOC)
6703 set_bit(EXTENT_FLAG_FILLING, &em->flags);
6704
6705 do {
6706 btrfs_drop_extent_cache(inode, em->start,
6707 em->start + em->len - 1, 0);
6708 write_lock(&em_tree->lock);
6709 ret = add_extent_mapping(em_tree, em);
6710 if (!ret)
6711 list_move(&em->list,
6712 &em_tree->modified_extents);
6713 write_unlock(&em_tree->lock);
6714 } while (ret == -EEXIST);
6715
6716 if (ret) {
6717 free_extent_map(em);
6718 return ERR_PTR(ret);
6719 }
6720
6721 return em;
6722 }
6723
6724
6725 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
6726 struct buffer_head *bh_result, int create)
6727 {
6728 struct extent_map *em;
6729 struct btrfs_root *root = BTRFS_I(inode)->root;
6730 struct extent_state *cached_state = NULL;
6731 u64 start = iblock << inode->i_blkbits;
6732 u64 lockstart, lockend;
6733 u64 len = bh_result->b_size;
6734 struct btrfs_trans_handle *trans;
6735 int unlock_bits = EXTENT_LOCKED;
6736 int ret = 0;
6737
6738 if (create)
6739 unlock_bits |= EXTENT_DELALLOC | EXTENT_DIRTY;
6740 else
6741 len = min_t(u64, len, root->sectorsize);
6742
6743 lockstart = start;
6744 lockend = start + len - 1;
6745
6746 /*
6747 * If this errors out it's because we couldn't invalidate pagecache for
6748 * this range and we need to fallback to buffered.
6749 */
6750 if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create))
6751 return -ENOTBLK;
6752
6753 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
6754 if (IS_ERR(em)) {
6755 ret = PTR_ERR(em);
6756 goto unlock_err;
6757 }
6758
6759 /*
6760 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
6761 * io. INLINE is special, and we could probably kludge it in here, but
6762 * it's still buffered so for safety lets just fall back to the generic
6763 * buffered path.
6764 *
6765 * For COMPRESSED we _have_ to read the entire extent in so we can
6766 * decompress it, so there will be buffering required no matter what we
6767 * do, so go ahead and fallback to buffered.
6768 *
6769 * We return -ENOTBLK because thats what makes DIO go ahead and go back
6770 * to buffered IO. Don't blame me, this is the price we pay for using
6771 * the generic code.
6772 */
6773 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
6774 em->block_start == EXTENT_MAP_INLINE) {
6775 free_extent_map(em);
6776 ret = -ENOTBLK;
6777 goto unlock_err;
6778 }
6779
6780 /* Just a good old fashioned hole, return */
6781 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
6782 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
6783 free_extent_map(em);
6784 goto unlock_err;
6785 }
6786
6787 /*
6788 * We don't allocate a new extent in the following cases
6789 *
6790 * 1) The inode is marked as NODATACOW. In this case we'll just use the
6791 * existing extent.
6792 * 2) The extent is marked as PREALLOC. We're good to go here and can
6793 * just use the extent.
6794 *
6795 */
6796 if (!create) {
6797 len = min(len, em->len - (start - em->start));
6798 lockstart = start + len;
6799 goto unlock;
6800 }
6801
6802 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
6803 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
6804 em->block_start != EXTENT_MAP_HOLE)) {
6805 int type;
6806 int ret;
6807 u64 block_start;
6808
6809 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6810 type = BTRFS_ORDERED_PREALLOC;
6811 else
6812 type = BTRFS_ORDERED_NOCOW;
6813 len = min(len, em->len - (start - em->start));
6814 block_start = em->block_start + (start - em->start);
6815
6816 /*
6817 * we're not going to log anything, but we do need
6818 * to make sure the current transaction stays open
6819 * while we look for nocow cross refs
6820 */
6821 trans = btrfs_join_transaction(root);
6822 if (IS_ERR(trans))
6823 goto must_cow;
6824
6825 if (can_nocow_odirect(trans, inode, start, len) == 1) {
6826 u64 orig_start = em->orig_start;
6827 u64 orig_block_len = em->orig_block_len;
6828 u64 ram_bytes = em->ram_bytes;
6829
6830 if (type == BTRFS_ORDERED_PREALLOC) {
6831 free_extent_map(em);
6832 em = create_pinned_em(inode, start, len,
6833 orig_start,
6834 block_start, len,
6835 orig_block_len,
6836 ram_bytes, type);
6837 if (IS_ERR(em)) {
6838 btrfs_end_transaction(trans, root);
6839 goto unlock_err;
6840 }
6841 }
6842
6843 ret = btrfs_add_ordered_extent_dio(inode, start,
6844 block_start, len, len, type);
6845 btrfs_end_transaction(trans, root);
6846 if (ret) {
6847 free_extent_map(em);
6848 goto unlock_err;
6849 }
6850 goto unlock;
6851 }
6852 btrfs_end_transaction(trans, root);
6853 }
6854 must_cow:
6855 /*
6856 * this will cow the extent, reset the len in case we changed
6857 * it above
6858 */
6859 len = bh_result->b_size;
6860 free_extent_map(em);
6861 em = btrfs_new_extent_direct(inode, start, len);
6862 if (IS_ERR(em)) {
6863 ret = PTR_ERR(em);
6864 goto unlock_err;
6865 }
6866 len = min(len, em->len - (start - em->start));
6867 unlock:
6868 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
6869 inode->i_blkbits;
6870 bh_result->b_size = len;
6871 bh_result->b_bdev = em->bdev;
6872 set_buffer_mapped(bh_result);
6873 if (create) {
6874 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6875 set_buffer_new(bh_result);
6876
6877 /*
6878 * Need to update the i_size under the extent lock so buffered
6879 * readers will get the updated i_size when we unlock.
6880 */
6881 if (start + len > i_size_read(inode))
6882 i_size_write(inode, start + len);
6883
6884 spin_lock(&BTRFS_I(inode)->lock);
6885 BTRFS_I(inode)->outstanding_extents++;
6886 spin_unlock(&BTRFS_I(inode)->lock);
6887
6888 ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6889 lockstart + len - 1, EXTENT_DELALLOC, NULL,
6890 &cached_state, GFP_NOFS);
6891 BUG_ON(ret);
6892 }
6893
6894 /*
6895 * In the case of write we need to clear and unlock the entire range,
6896 * in the case of read we need to unlock only the end area that we
6897 * aren't using if there is any left over space.
6898 */
6899 if (lockstart < lockend) {
6900 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
6901 lockend, unlock_bits, 1, 0,
6902 &cached_state, GFP_NOFS);
6903 } else {
6904 free_extent_state(cached_state);
6905 }
6906
6907 free_extent_map(em);
6908
6909 return 0;
6910
6911 unlock_err:
6912 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6913 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
6914 return ret;
6915 }
6916
6917 struct btrfs_dio_private {
6918 struct inode *inode;
6919 u64 logical_offset;
6920 u64 disk_bytenr;
6921 u64 bytes;
6922 void *private;
6923
6924 /* number of bios pending for this dio */
6925 atomic_t pending_bios;
6926
6927 /* IO errors */
6928 int errors;
6929
6930 struct bio *orig_bio;
6931 };
6932
6933 static void btrfs_endio_direct_read(struct bio *bio, int err)
6934 {
6935 struct btrfs_dio_private *dip = bio->bi_private;
6936 struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
6937 struct bio_vec *bvec = bio->bi_io_vec;
6938 struct inode *inode = dip->inode;
6939 struct btrfs_root *root = BTRFS_I(inode)->root;
6940 u64 start;
6941
6942 start = dip->logical_offset;
6943 do {
6944 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
6945 struct page *page = bvec->bv_page;
6946 char *kaddr;
6947 u32 csum = ~(u32)0;
6948 u64 private = ~(u32)0;
6949 unsigned long flags;
6950
6951 if (get_state_private(&BTRFS_I(inode)->io_tree,
6952 start, &private))
6953 goto failed;
6954 local_irq_save(flags);
6955 kaddr = kmap_atomic(page);
6956 csum = btrfs_csum_data(kaddr + bvec->bv_offset,
6957 csum, bvec->bv_len);
6958 btrfs_csum_final(csum, (char *)&csum);
6959 kunmap_atomic(kaddr);
6960 local_irq_restore(flags);
6961
6962 flush_dcache_page(bvec->bv_page);
6963 if (csum != private) {
6964 failed:
6965 btrfs_err(root->fs_info, "csum failed ino %llu off %llu csum %u private %u",
6966 (unsigned long long)btrfs_ino(inode),
6967 (unsigned long long)start,
6968 csum, (unsigned)private);
6969 err = -EIO;
6970 }
6971 }
6972
6973 start += bvec->bv_len;
6974 bvec++;
6975 } while (bvec <= bvec_end);
6976
6977 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
6978 dip->logical_offset + dip->bytes - 1);
6979 bio->bi_private = dip->private;
6980
6981 kfree(dip);
6982
6983 /* If we had a csum failure make sure to clear the uptodate flag */
6984 if (err)
6985 clear_bit(BIO_UPTODATE, &bio->bi_flags);
6986 dio_end_io(bio, err);
6987 }
6988
6989 static void btrfs_endio_direct_write(struct bio *bio, int err)
6990 {
6991 struct btrfs_dio_private *dip = bio->bi_private;
6992 struct inode *inode = dip->inode;
6993 struct btrfs_root *root = BTRFS_I(inode)->root;
6994 struct btrfs_ordered_extent *ordered = NULL;
6995 u64 ordered_offset = dip->logical_offset;
6996 u64 ordered_bytes = dip->bytes;
6997 int ret;
6998
6999 if (err)
7000 goto out_done;
7001 again:
7002 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
7003 &ordered_offset,
7004 ordered_bytes, !err);
7005 if (!ret)
7006 goto out_test;
7007
7008 ordered->work.func = finish_ordered_fn;
7009 ordered->work.flags = 0;
7010 btrfs_queue_worker(&root->fs_info->endio_write_workers,
7011 &ordered->work);
7012 out_test:
7013 /*
7014 * our bio might span multiple ordered extents. If we haven't
7015 * completed the accounting for the whole dio, go back and try again
7016 */
7017 if (ordered_offset < dip->logical_offset + dip->bytes) {
7018 ordered_bytes = dip->logical_offset + dip->bytes -
7019 ordered_offset;
7020 ordered = NULL;
7021 goto again;
7022 }
7023 out_done:
7024 bio->bi_private = dip->private;
7025
7026 kfree(dip);
7027
7028 /* If we had an error make sure to clear the uptodate flag */
7029 if (err)
7030 clear_bit(BIO_UPTODATE, &bio->bi_flags);
7031 dio_end_io(bio, err);
7032 }
7033
7034 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
7035 struct bio *bio, int mirror_num,
7036 unsigned long bio_flags, u64 offset)
7037 {
7038 int ret;
7039 struct btrfs_root *root = BTRFS_I(inode)->root;
7040 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
7041 BUG_ON(ret); /* -ENOMEM */
7042 return 0;
7043 }
7044
7045 static void btrfs_end_dio_bio(struct bio *bio, int err)
7046 {
7047 struct btrfs_dio_private *dip = bio->bi_private;
7048
7049 if (err) {
7050 printk(KERN_ERR "btrfs direct IO failed ino %llu rw %lu "
7051 "sector %#Lx len %u err no %d\n",
7052 (unsigned long long)btrfs_ino(dip->inode), bio->bi_rw,
7053 (unsigned long long)bio->bi_sector, bio->bi_size, err);
7054 dip->errors = 1;
7055
7056 /*
7057 * before atomic variable goto zero, we must make sure
7058 * dip->errors is perceived to be set.
7059 */
7060 smp_mb__before_atomic_dec();
7061 }
7062
7063 /* if there are more bios still pending for this dio, just exit */
7064 if (!atomic_dec_and_test(&dip->pending_bios))
7065 goto out;
7066
7067 if (dip->errors)
7068 bio_io_error(dip->orig_bio);
7069 else {
7070 set_bit(BIO_UPTODATE, &dip->orig_bio->bi_flags);
7071 bio_endio(dip->orig_bio, 0);
7072 }
7073 out:
7074 bio_put(bio);
7075 }
7076
7077 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
7078 u64 first_sector, gfp_t gfp_flags)
7079 {
7080 int nr_vecs = bio_get_nr_vecs(bdev);
7081 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
7082 }
7083
7084 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
7085 int rw, u64 file_offset, int skip_sum,
7086 int async_submit)
7087 {
7088 int write = rw & REQ_WRITE;
7089 struct btrfs_root *root = BTRFS_I(inode)->root;
7090 int ret;
7091
7092 if (async_submit)
7093 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
7094
7095 bio_get(bio);
7096
7097 if (!write) {
7098 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
7099 if (ret)
7100 goto err;
7101 }
7102
7103 if (skip_sum)
7104 goto map;
7105
7106 if (write && async_submit) {
7107 ret = btrfs_wq_submit_bio(root->fs_info,
7108 inode, rw, bio, 0, 0,
7109 file_offset,
7110 __btrfs_submit_bio_start_direct_io,
7111 __btrfs_submit_bio_done);
7112 goto err;
7113 } else if (write) {
7114 /*
7115 * If we aren't doing async submit, calculate the csum of the
7116 * bio now.
7117 */
7118 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
7119 if (ret)
7120 goto err;
7121 } else if (!skip_sum) {
7122 ret = btrfs_lookup_bio_sums_dio(root, inode, bio, file_offset);
7123 if (ret)
7124 goto err;
7125 }
7126
7127 map:
7128 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
7129 err:
7130 bio_put(bio);
7131 return ret;
7132 }
7133
7134 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
7135 int skip_sum)
7136 {
7137 struct inode *inode = dip->inode;
7138 struct btrfs_root *root = BTRFS_I(inode)->root;
7139 struct bio *bio;
7140 struct bio *orig_bio = dip->orig_bio;
7141 struct bio_vec *bvec = orig_bio->bi_io_vec;
7142 u64 start_sector = orig_bio->bi_sector;
7143 u64 file_offset = dip->logical_offset;
7144 u64 submit_len = 0;
7145 u64 map_length;
7146 int nr_pages = 0;
7147 int ret = 0;
7148 int async_submit = 0;
7149
7150 map_length = orig_bio->bi_size;
7151 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
7152 &map_length, NULL, 0);
7153 if (ret) {
7154 bio_put(orig_bio);
7155 return -EIO;
7156 }
7157 if (map_length >= orig_bio->bi_size) {
7158 bio = orig_bio;
7159 goto submit;
7160 }
7161
7162 /* async crcs make it difficult to collect full stripe writes. */
7163 if (btrfs_get_alloc_profile(root, 1) &
7164 (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6))
7165 async_submit = 0;
7166 else
7167 async_submit = 1;
7168
7169 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
7170 if (!bio)
7171 return -ENOMEM;
7172 bio->bi_private = dip;
7173 bio->bi_end_io = btrfs_end_dio_bio;
7174 atomic_inc(&dip->pending_bios);
7175
7176 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
7177 if (unlikely(map_length < submit_len + bvec->bv_len ||
7178 bio_add_page(bio, bvec->bv_page, bvec->bv_len,
7179 bvec->bv_offset) < bvec->bv_len)) {
7180 /*
7181 * inc the count before we submit the bio so
7182 * we know the end IO handler won't happen before
7183 * we inc the count. Otherwise, the dip might get freed
7184 * before we're done setting it up
7185 */
7186 atomic_inc(&dip->pending_bios);
7187 ret = __btrfs_submit_dio_bio(bio, inode, rw,
7188 file_offset, skip_sum,
7189 async_submit);
7190 if (ret) {
7191 bio_put(bio);
7192 atomic_dec(&dip->pending_bios);
7193 goto out_err;
7194 }
7195
7196 start_sector += submit_len >> 9;
7197 file_offset += submit_len;
7198
7199 submit_len = 0;
7200 nr_pages = 0;
7201
7202 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
7203 start_sector, GFP_NOFS);
7204 if (!bio)
7205 goto out_err;
7206 bio->bi_private = dip;
7207 bio->bi_end_io = btrfs_end_dio_bio;
7208
7209 map_length = orig_bio->bi_size;
7210 ret = btrfs_map_block(root->fs_info, rw,
7211 start_sector << 9,
7212 &map_length, NULL, 0);
7213 if (ret) {
7214 bio_put(bio);
7215 goto out_err;
7216 }
7217 } else {
7218 submit_len += bvec->bv_len;
7219 nr_pages ++;
7220 bvec++;
7221 }
7222 }
7223
7224 submit:
7225 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
7226 async_submit);
7227 if (!ret)
7228 return 0;
7229
7230 bio_put(bio);
7231 out_err:
7232 dip->errors = 1;
7233 /*
7234 * before atomic variable goto zero, we must
7235 * make sure dip->errors is perceived to be set.
7236 */
7237 smp_mb__before_atomic_dec();
7238 if (atomic_dec_and_test(&dip->pending_bios))
7239 bio_io_error(dip->orig_bio);
7240
7241 /* bio_end_io() will handle error, so we needn't return it */
7242 return 0;
7243 }
7244
7245 static void btrfs_submit_direct(int rw, struct bio *bio, struct inode *inode,
7246 loff_t file_offset)
7247 {
7248 struct btrfs_root *root = BTRFS_I(inode)->root;
7249 struct btrfs_dio_private *dip;
7250 struct bio_vec *bvec = bio->bi_io_vec;
7251 int skip_sum;
7252 int write = rw & REQ_WRITE;
7253 int ret = 0;
7254
7255 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
7256
7257 dip = kmalloc(sizeof(*dip), GFP_NOFS);
7258 if (!dip) {
7259 ret = -ENOMEM;
7260 goto free_ordered;
7261 }
7262
7263 dip->private = bio->bi_private;
7264 dip->inode = inode;
7265 dip->logical_offset = file_offset;
7266
7267 dip->bytes = 0;
7268 do {
7269 dip->bytes += bvec->bv_len;
7270 bvec++;
7271 } while (bvec <= (bio->bi_io_vec + bio->bi_vcnt - 1));
7272
7273 dip->disk_bytenr = (u64)bio->bi_sector << 9;
7274 bio->bi_private = dip;
7275 dip->errors = 0;
7276 dip->orig_bio = bio;
7277 atomic_set(&dip->pending_bios, 0);
7278
7279 if (write)
7280 bio->bi_end_io = btrfs_endio_direct_write;
7281 else
7282 bio->bi_end_io = btrfs_endio_direct_read;
7283
7284 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
7285 if (!ret)
7286 return;
7287 free_ordered:
7288 /*
7289 * If this is a write, we need to clean up the reserved space and kill
7290 * the ordered extent.
7291 */
7292 if (write) {
7293 struct btrfs_ordered_extent *ordered;
7294 ordered = btrfs_lookup_ordered_extent(inode, file_offset);
7295 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
7296 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
7297 btrfs_free_reserved_extent(root, ordered->start,
7298 ordered->disk_len);
7299 btrfs_put_ordered_extent(ordered);
7300 btrfs_put_ordered_extent(ordered);
7301 }
7302 bio_endio(bio, ret);
7303 }
7304
7305 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb,
7306 const struct iovec *iov, loff_t offset,
7307 unsigned long nr_segs)
7308 {
7309 int seg;
7310 int i;
7311 size_t size;
7312 unsigned long addr;
7313 unsigned blocksize_mask = root->sectorsize - 1;
7314 ssize_t retval = -EINVAL;
7315 loff_t end = offset;
7316
7317 if (offset & blocksize_mask)
7318 goto out;
7319
7320 /* Check the memory alignment. Blocks cannot straddle pages */
7321 for (seg = 0; seg < nr_segs; seg++) {
7322 addr = (unsigned long)iov[seg].iov_base;
7323 size = iov[seg].iov_len;
7324 end += size;
7325 if ((addr & blocksize_mask) || (size & blocksize_mask))
7326 goto out;
7327
7328 /* If this is a write we don't need to check anymore */
7329 if (rw & WRITE)
7330 continue;
7331
7332 /*
7333 * Check to make sure we don't have duplicate iov_base's in this
7334 * iovec, if so return EINVAL, otherwise we'll get csum errors
7335 * when reading back.
7336 */
7337 for (i = seg + 1; i < nr_segs; i++) {
7338 if (iov[seg].iov_base == iov[i].iov_base)
7339 goto out;
7340 }
7341 }
7342 retval = 0;
7343 out:
7344 return retval;
7345 }
7346
7347 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
7348 const struct iovec *iov, loff_t offset,
7349 unsigned long nr_segs)
7350 {
7351 struct file *file = iocb->ki_filp;
7352 struct inode *inode = file->f_mapping->host;
7353 size_t count = 0;
7354 int flags = 0;
7355 bool wakeup = true;
7356 bool relock = false;
7357 ssize_t ret;
7358
7359 if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
7360 offset, nr_segs))
7361 return 0;
7362
7363 atomic_inc(&inode->i_dio_count);
7364 smp_mb__after_atomic_inc();
7365
7366 if (rw & WRITE) {
7367 count = iov_length(iov, nr_segs);
7368 /*
7369 * If the write DIO is beyond the EOF, we need update
7370 * the isize, but it is protected by i_mutex. So we can
7371 * not unlock the i_mutex at this case.
7372 */
7373 if (offset + count <= inode->i_size) {
7374 mutex_unlock(&inode->i_mutex);
7375 relock = true;
7376 }
7377 ret = btrfs_delalloc_reserve_space(inode, count);
7378 if (ret)
7379 goto out;
7380 } else if (unlikely(test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
7381 &BTRFS_I(inode)->runtime_flags))) {
7382 inode_dio_done(inode);
7383 flags = DIO_LOCKING | DIO_SKIP_HOLES;
7384 wakeup = false;
7385 }
7386
7387 ret = __blockdev_direct_IO(rw, iocb, inode,
7388 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
7389 iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
7390 btrfs_submit_direct, flags);
7391 if (rw & WRITE) {
7392 if (ret < 0 && ret != -EIOCBQUEUED)
7393 btrfs_delalloc_release_space(inode, count);
7394 else if (ret >= 0 && (size_t)ret < count)
7395 btrfs_delalloc_release_space(inode,
7396 count - (size_t)ret);
7397 else
7398 btrfs_delalloc_release_metadata(inode, 0);
7399 }
7400 out:
7401 if (wakeup)
7402 inode_dio_done(inode);
7403 if (relock)
7404 mutex_lock(&inode->i_mutex);
7405
7406 return ret;
7407 }
7408
7409 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
7410
7411 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
7412 __u64 start, __u64 len)
7413 {
7414 int ret;
7415
7416 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
7417 if (ret)
7418 return ret;
7419
7420 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
7421 }
7422
7423 int btrfs_readpage(struct file *file, struct page *page)
7424 {
7425 struct extent_io_tree *tree;
7426 tree = &BTRFS_I(page->mapping->host)->io_tree;
7427 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
7428 }
7429
7430 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
7431 {
7432 struct extent_io_tree *tree;
7433
7434
7435 if (current->flags & PF_MEMALLOC) {
7436 redirty_page_for_writepage(wbc, page);
7437 unlock_page(page);
7438 return 0;
7439 }
7440 tree = &BTRFS_I(page->mapping->host)->io_tree;
7441 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
7442 }
7443
7444 int btrfs_writepages(struct address_space *mapping,
7445 struct writeback_control *wbc)
7446 {
7447 struct extent_io_tree *tree;
7448
7449 tree = &BTRFS_I(mapping->host)->io_tree;
7450 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
7451 }
7452
7453 static int
7454 btrfs_readpages(struct file *file, struct address_space *mapping,
7455 struct list_head *pages, unsigned nr_pages)
7456 {
7457 struct extent_io_tree *tree;
7458 tree = &BTRFS_I(mapping->host)->io_tree;
7459 return extent_readpages(tree, mapping, pages, nr_pages,
7460 btrfs_get_extent);
7461 }
7462 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
7463 {
7464 struct extent_io_tree *tree;
7465 struct extent_map_tree *map;
7466 int ret;
7467
7468 tree = &BTRFS_I(page->mapping->host)->io_tree;
7469 map = &BTRFS_I(page->mapping->host)->extent_tree;
7470 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
7471 if (ret == 1) {
7472 ClearPagePrivate(page);
7473 set_page_private(page, 0);
7474 page_cache_release(page);
7475 }
7476 return ret;
7477 }
7478
7479 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
7480 {
7481 if (PageWriteback(page) || PageDirty(page))
7482 return 0;
7483 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
7484 }
7485
7486 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
7487 {
7488 struct inode *inode = page->mapping->host;
7489 struct extent_io_tree *tree;
7490 struct btrfs_ordered_extent *ordered;
7491 struct extent_state *cached_state = NULL;
7492 u64 page_start = page_offset(page);
7493 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
7494
7495 /*
7496 * we have the page locked, so new writeback can't start,
7497 * and the dirty bit won't be cleared while we are here.
7498 *
7499 * Wait for IO on this page so that we can safely clear
7500 * the PagePrivate2 bit and do ordered accounting
7501 */
7502 wait_on_page_writeback(page);
7503
7504 tree = &BTRFS_I(inode)->io_tree;
7505 if (offset) {
7506 btrfs_releasepage(page, GFP_NOFS);
7507 return;
7508 }
7509 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
7510 ordered = btrfs_lookup_ordered_extent(inode, page_offset(page));
7511 if (ordered) {
7512 /*
7513 * IO on this page will never be started, so we need
7514 * to account for any ordered extents now
7515 */
7516 clear_extent_bit(tree, page_start, page_end,
7517 EXTENT_DIRTY | EXTENT_DELALLOC |
7518 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
7519 EXTENT_DEFRAG, 1, 0, &cached_state, GFP_NOFS);
7520 /*
7521 * whoever cleared the private bit is responsible
7522 * for the finish_ordered_io
7523 */
7524 if (TestClearPagePrivate2(page) &&
7525 btrfs_dec_test_ordered_pending(inode, &ordered, page_start,
7526 PAGE_CACHE_SIZE, 1)) {
7527 btrfs_finish_ordered_io(ordered);
7528 }
7529 btrfs_put_ordered_extent(ordered);
7530 cached_state = NULL;
7531 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
7532 }
7533 clear_extent_bit(tree, page_start, page_end,
7534 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
7535 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
7536 &cached_state, GFP_NOFS);
7537 __btrfs_releasepage(page, GFP_NOFS);
7538
7539 ClearPageChecked(page);
7540 if (PagePrivate(page)) {
7541 ClearPagePrivate(page);
7542 set_page_private(page, 0);
7543 page_cache_release(page);
7544 }
7545 }
7546
7547 /*
7548 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
7549 * called from a page fault handler when a page is first dirtied. Hence we must
7550 * be careful to check for EOF conditions here. We set the page up correctly
7551 * for a written page which means we get ENOSPC checking when writing into
7552 * holes and correct delalloc and unwritten extent mapping on filesystems that
7553 * support these features.
7554 *
7555 * We are not allowed to take the i_mutex here so we have to play games to
7556 * protect against truncate races as the page could now be beyond EOF. Because
7557 * vmtruncate() writes the inode size before removing pages, once we have the
7558 * page lock we can determine safely if the page is beyond EOF. If it is not
7559 * beyond EOF, then the page is guaranteed safe against truncation until we
7560 * unlock the page.
7561 */
7562 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
7563 {
7564 struct page *page = vmf->page;
7565 struct inode *inode = file_inode(vma->vm_file);
7566 struct btrfs_root *root = BTRFS_I(inode)->root;
7567 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7568 struct btrfs_ordered_extent *ordered;
7569 struct extent_state *cached_state = NULL;
7570 char *kaddr;
7571 unsigned long zero_start;
7572 loff_t size;
7573 int ret;
7574 int reserved = 0;
7575 u64 page_start;
7576 u64 page_end;
7577
7578 sb_start_pagefault(inode->i_sb);
7579 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
7580 if (!ret) {
7581 ret = file_update_time(vma->vm_file);
7582 reserved = 1;
7583 }
7584 if (ret) {
7585 if (ret == -ENOMEM)
7586 ret = VM_FAULT_OOM;
7587 else /* -ENOSPC, -EIO, etc */
7588 ret = VM_FAULT_SIGBUS;
7589 if (reserved)
7590 goto out;
7591 goto out_noreserve;
7592 }
7593
7594 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
7595 again:
7596 lock_page(page);
7597 size = i_size_read(inode);
7598 page_start = page_offset(page);
7599 page_end = page_start + PAGE_CACHE_SIZE - 1;
7600
7601 if ((page->mapping != inode->i_mapping) ||
7602 (page_start >= size)) {
7603 /* page got truncated out from underneath us */
7604 goto out_unlock;
7605 }
7606 wait_on_page_writeback(page);
7607
7608 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
7609 set_page_extent_mapped(page);
7610
7611 /*
7612 * we can't set the delalloc bits if there are pending ordered
7613 * extents. Drop our locks and wait for them to finish
7614 */
7615 ordered = btrfs_lookup_ordered_extent(inode, page_start);
7616 if (ordered) {
7617 unlock_extent_cached(io_tree, page_start, page_end,
7618 &cached_state, GFP_NOFS);
7619 unlock_page(page);
7620 btrfs_start_ordered_extent(inode, ordered, 1);
7621 btrfs_put_ordered_extent(ordered);
7622 goto again;
7623 }
7624
7625 /*
7626 * XXX - page_mkwrite gets called every time the page is dirtied, even
7627 * if it was already dirty, so for space accounting reasons we need to
7628 * clear any delalloc bits for the range we are fixing to save. There
7629 * is probably a better way to do this, but for now keep consistent with
7630 * prepare_pages in the normal write path.
7631 */
7632 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
7633 EXTENT_DIRTY | EXTENT_DELALLOC |
7634 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
7635 0, 0, &cached_state, GFP_NOFS);
7636
7637 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
7638 &cached_state);
7639 if (ret) {
7640 unlock_extent_cached(io_tree, page_start, page_end,
7641 &cached_state, GFP_NOFS);
7642 ret = VM_FAULT_SIGBUS;
7643 goto out_unlock;
7644 }
7645 ret = 0;
7646
7647 /* page is wholly or partially inside EOF */
7648 if (page_start + PAGE_CACHE_SIZE > size)
7649 zero_start = size & ~PAGE_CACHE_MASK;
7650 else
7651 zero_start = PAGE_CACHE_SIZE;
7652
7653 if (zero_start != PAGE_CACHE_SIZE) {
7654 kaddr = kmap(page);
7655 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
7656 flush_dcache_page(page);
7657 kunmap(page);
7658 }
7659 ClearPageChecked(page);
7660 set_page_dirty(page);
7661 SetPageUptodate(page);
7662
7663 BTRFS_I(inode)->last_trans = root->fs_info->generation;
7664 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
7665 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
7666
7667 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
7668
7669 out_unlock:
7670 if (!ret) {
7671 sb_end_pagefault(inode->i_sb);
7672 return VM_FAULT_LOCKED;
7673 }
7674 unlock_page(page);
7675 out:
7676 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
7677 out_noreserve:
7678 sb_end_pagefault(inode->i_sb);
7679 return ret;
7680 }
7681
7682 static int btrfs_truncate(struct inode *inode)
7683 {
7684 struct btrfs_root *root = BTRFS_I(inode)->root;
7685 struct btrfs_block_rsv *rsv;
7686 int ret;
7687 int err = 0;
7688 struct btrfs_trans_handle *trans;
7689 u64 mask = root->sectorsize - 1;
7690 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
7691
7692 ret = btrfs_truncate_page(inode, inode->i_size, 0, 0);
7693 if (ret)
7694 return ret;
7695
7696 btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
7697 btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
7698
7699 /*
7700 * Yes ladies and gentelment, this is indeed ugly. The fact is we have
7701 * 3 things going on here
7702 *
7703 * 1) We need to reserve space for our orphan item and the space to
7704 * delete our orphan item. Lord knows we don't want to have a dangling
7705 * orphan item because we didn't reserve space to remove it.
7706 *
7707 * 2) We need to reserve space to update our inode.
7708 *
7709 * 3) We need to have something to cache all the space that is going to
7710 * be free'd up by the truncate operation, but also have some slack
7711 * space reserved in case it uses space during the truncate (thank you
7712 * very much snapshotting).
7713 *
7714 * And we need these to all be seperate. The fact is we can use alot of
7715 * space doing the truncate, and we have no earthly idea how much space
7716 * we will use, so we need the truncate reservation to be seperate so it
7717 * doesn't end up using space reserved for updating the inode or
7718 * removing the orphan item. We also need to be able to stop the
7719 * transaction and start a new one, which means we need to be able to
7720 * update the inode several times, and we have no idea of knowing how
7721 * many times that will be, so we can't just reserve 1 item for the
7722 * entirety of the opration, so that has to be done seperately as well.
7723 * Then there is the orphan item, which does indeed need to be held on
7724 * to for the whole operation, and we need nobody to touch this reserved
7725 * space except the orphan code.
7726 *
7727 * So that leaves us with
7728 *
7729 * 1) root->orphan_block_rsv - for the orphan deletion.
7730 * 2) rsv - for the truncate reservation, which we will steal from the
7731 * transaction reservation.
7732 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
7733 * updating the inode.
7734 */
7735 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
7736 if (!rsv)
7737 return -ENOMEM;
7738 rsv->size = min_size;
7739 rsv->failfast = 1;
7740
7741 /*
7742 * 1 for the truncate slack space
7743 * 1 for updating the inode.
7744 */
7745 trans = btrfs_start_transaction(root, 2);
7746 if (IS_ERR(trans)) {
7747 err = PTR_ERR(trans);
7748 goto out;
7749 }
7750
7751 /* Migrate the slack space for the truncate to our reserve */
7752 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
7753 min_size);
7754 BUG_ON(ret);
7755
7756 /*
7757 * setattr is responsible for setting the ordered_data_close flag,
7758 * but that is only tested during the last file release. That
7759 * could happen well after the next commit, leaving a great big
7760 * window where new writes may get lost if someone chooses to write
7761 * to this file after truncating to zero
7762 *
7763 * The inode doesn't have any dirty data here, and so if we commit
7764 * this is a noop. If someone immediately starts writing to the inode
7765 * it is very likely we'll catch some of their writes in this
7766 * transaction, and the commit will find this file on the ordered
7767 * data list with good things to send down.
7768 *
7769 * This is a best effort solution, there is still a window where
7770 * using truncate to replace the contents of the file will
7771 * end up with a zero length file after a crash.
7772 */
7773 if (inode->i_size == 0 && test_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
7774 &BTRFS_I(inode)->runtime_flags))
7775 btrfs_add_ordered_operation(trans, root, inode);
7776
7777 /*
7778 * So if we truncate and then write and fsync we normally would just
7779 * write the extents that changed, which is a problem if we need to
7780 * first truncate that entire inode. So set this flag so we write out
7781 * all of the extents in the inode to the sync log so we're completely
7782 * safe.
7783 */
7784 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
7785 trans->block_rsv = rsv;
7786
7787 while (1) {
7788 ret = btrfs_truncate_inode_items(trans, root, inode,
7789 inode->i_size,
7790 BTRFS_EXTENT_DATA_KEY);
7791 if (ret != -ENOSPC) {
7792 err = ret;
7793 break;
7794 }
7795
7796 trans->block_rsv = &root->fs_info->trans_block_rsv;
7797 ret = btrfs_update_inode(trans, root, inode);
7798 if (ret) {
7799 err = ret;
7800 break;
7801 }
7802
7803 btrfs_end_transaction(trans, root);
7804 btrfs_btree_balance_dirty(root);
7805
7806 trans = btrfs_start_transaction(root, 2);
7807 if (IS_ERR(trans)) {
7808 ret = err = PTR_ERR(trans);
7809 trans = NULL;
7810 break;
7811 }
7812
7813 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
7814 rsv, min_size);
7815 BUG_ON(ret); /* shouldn't happen */
7816 trans->block_rsv = rsv;
7817 }
7818
7819 if (ret == 0 && inode->i_nlink > 0) {
7820 trans->block_rsv = root->orphan_block_rsv;
7821 ret = btrfs_orphan_del(trans, inode);
7822 if (ret)
7823 err = ret;
7824 }
7825
7826 if (trans) {
7827 trans->block_rsv = &root->fs_info->trans_block_rsv;
7828 ret = btrfs_update_inode(trans, root, inode);
7829 if (ret && !err)
7830 err = ret;
7831
7832 ret = btrfs_end_transaction(trans, root);
7833 btrfs_btree_balance_dirty(root);
7834 }
7835
7836 out:
7837 btrfs_free_block_rsv(root, rsv);
7838
7839 if (ret && !err)
7840 err = ret;
7841
7842 return err;
7843 }
7844
7845 /*
7846 * create a new subvolume directory/inode (helper for the ioctl).
7847 */
7848 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
7849 struct btrfs_root *new_root, u64 new_dirid)
7850 {
7851 struct inode *inode;
7852 int err;
7853 u64 index = 0;
7854
7855 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
7856 new_dirid, new_dirid,
7857 S_IFDIR | (~current_umask() & S_IRWXUGO),
7858 &index);
7859 if (IS_ERR(inode))
7860 return PTR_ERR(inode);
7861 inode->i_op = &btrfs_dir_inode_operations;
7862 inode->i_fop = &btrfs_dir_file_operations;
7863
7864 set_nlink(inode, 1);
7865 btrfs_i_size_write(inode, 0);
7866
7867 err = btrfs_update_inode(trans, new_root, inode);
7868
7869 iput(inode);
7870 return err;
7871 }
7872
7873 struct inode *btrfs_alloc_inode(struct super_block *sb)
7874 {
7875 struct btrfs_inode *ei;
7876 struct inode *inode;
7877
7878 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
7879 if (!ei)
7880 return NULL;
7881
7882 ei->root = NULL;
7883 ei->generation = 0;
7884 ei->last_trans = 0;
7885 ei->last_sub_trans = 0;
7886 ei->logged_trans = 0;
7887 ei->delalloc_bytes = 0;
7888 ei->disk_i_size = 0;
7889 ei->flags = 0;
7890 ei->csum_bytes = 0;
7891 ei->index_cnt = (u64)-1;
7892 ei->last_unlink_trans = 0;
7893 ei->last_log_commit = 0;
7894
7895 spin_lock_init(&ei->lock);
7896 ei->outstanding_extents = 0;
7897 ei->reserved_extents = 0;
7898
7899 ei->runtime_flags = 0;
7900 ei->force_compress = BTRFS_COMPRESS_NONE;
7901
7902 ei->delayed_node = NULL;
7903
7904 inode = &ei->vfs_inode;
7905 extent_map_tree_init(&ei->extent_tree);
7906 extent_io_tree_init(&ei->io_tree, &inode->i_data);
7907 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
7908 ei->io_tree.track_uptodate = 1;
7909 ei->io_failure_tree.track_uptodate = 1;
7910 atomic_set(&ei->sync_writers, 0);
7911 mutex_init(&ei->log_mutex);
7912 mutex_init(&ei->delalloc_mutex);
7913 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
7914 INIT_LIST_HEAD(&ei->delalloc_inodes);
7915 INIT_LIST_HEAD(&ei->ordered_operations);
7916 RB_CLEAR_NODE(&ei->rb_node);
7917
7918 return inode;
7919 }
7920
7921 static void btrfs_i_callback(struct rcu_head *head)
7922 {
7923 struct inode *inode = container_of(head, struct inode, i_rcu);
7924 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
7925 }
7926
7927 void btrfs_destroy_inode(struct inode *inode)
7928 {
7929 struct btrfs_ordered_extent *ordered;
7930 struct btrfs_root *root = BTRFS_I(inode)->root;
7931
7932 WARN_ON(!hlist_empty(&inode->i_dentry));
7933 WARN_ON(inode->i_data.nrpages);
7934 WARN_ON(BTRFS_I(inode)->outstanding_extents);
7935 WARN_ON(BTRFS_I(inode)->reserved_extents);
7936 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
7937 WARN_ON(BTRFS_I(inode)->csum_bytes);
7938
7939 /*
7940 * This can happen where we create an inode, but somebody else also
7941 * created the same inode and we need to destroy the one we already
7942 * created.
7943 */
7944 if (!root)
7945 goto free;
7946
7947 /*
7948 * Make sure we're properly removed from the ordered operation
7949 * lists.
7950 */
7951 smp_mb();
7952 if (!list_empty(&BTRFS_I(inode)->ordered_operations)) {
7953 spin_lock(&root->fs_info->ordered_extent_lock);
7954 list_del_init(&BTRFS_I(inode)->ordered_operations);
7955 spin_unlock(&root->fs_info->ordered_extent_lock);
7956 }
7957
7958 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
7959 &BTRFS_I(inode)->runtime_flags)) {
7960 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
7961 (unsigned long long)btrfs_ino(inode));
7962 atomic_dec(&root->orphan_inodes);
7963 }
7964
7965 while (1) {
7966 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
7967 if (!ordered)
7968 break;
7969 else {
7970 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
7971 (unsigned long long)ordered->file_offset,
7972 (unsigned long long)ordered->len);
7973 btrfs_remove_ordered_extent(inode, ordered);
7974 btrfs_put_ordered_extent(ordered);
7975 btrfs_put_ordered_extent(ordered);
7976 }
7977 }
7978 inode_tree_del(inode);
7979 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
7980 free:
7981 btrfs_remove_delayed_node(inode);
7982 call_rcu(&inode->i_rcu, btrfs_i_callback);
7983 }
7984
7985 int btrfs_drop_inode(struct inode *inode)
7986 {
7987 struct btrfs_root *root = BTRFS_I(inode)->root;
7988
7989 /* the snap/subvol tree is on deleting */
7990 if (btrfs_root_refs(&root->root_item) == 0 &&
7991 root != root->fs_info->tree_root)
7992 return 1;
7993 else
7994 return generic_drop_inode(inode);
7995 }
7996
7997 static void init_once(void *foo)
7998 {
7999 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
8000
8001 inode_init_once(&ei->vfs_inode);
8002 }
8003
8004 void btrfs_destroy_cachep(void)
8005 {
8006 /*
8007 * Make sure all delayed rcu free inodes are flushed before we
8008 * destroy cache.
8009 */
8010 rcu_barrier();
8011 if (btrfs_inode_cachep)
8012 kmem_cache_destroy(btrfs_inode_cachep);
8013 if (btrfs_trans_handle_cachep)
8014 kmem_cache_destroy(btrfs_trans_handle_cachep);
8015 if (btrfs_transaction_cachep)
8016 kmem_cache_destroy(btrfs_transaction_cachep);
8017 if (btrfs_path_cachep)
8018 kmem_cache_destroy(btrfs_path_cachep);
8019 if (btrfs_free_space_cachep)
8020 kmem_cache_destroy(btrfs_free_space_cachep);
8021 if (btrfs_delalloc_work_cachep)
8022 kmem_cache_destroy(btrfs_delalloc_work_cachep);
8023 }
8024
8025 int btrfs_init_cachep(void)
8026 {
8027 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
8028 sizeof(struct btrfs_inode), 0,
8029 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
8030 if (!btrfs_inode_cachep)
8031 goto fail;
8032
8033 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
8034 sizeof(struct btrfs_trans_handle), 0,
8035 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8036 if (!btrfs_trans_handle_cachep)
8037 goto fail;
8038
8039 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
8040 sizeof(struct btrfs_transaction), 0,
8041 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8042 if (!btrfs_transaction_cachep)
8043 goto fail;
8044
8045 btrfs_path_cachep = kmem_cache_create("btrfs_path",
8046 sizeof(struct btrfs_path), 0,
8047 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8048 if (!btrfs_path_cachep)
8049 goto fail;
8050
8051 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
8052 sizeof(struct btrfs_free_space), 0,
8053 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8054 if (!btrfs_free_space_cachep)
8055 goto fail;
8056
8057 btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work",
8058 sizeof(struct btrfs_delalloc_work), 0,
8059 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
8060 NULL);
8061 if (!btrfs_delalloc_work_cachep)
8062 goto fail;
8063
8064 return 0;
8065 fail:
8066 btrfs_destroy_cachep();
8067 return -ENOMEM;
8068 }
8069
8070 static int btrfs_getattr(struct vfsmount *mnt,
8071 struct dentry *dentry, struct kstat *stat)
8072 {
8073 u64 delalloc_bytes;
8074 struct inode *inode = dentry->d_inode;
8075 u32 blocksize = inode->i_sb->s_blocksize;
8076
8077 generic_fillattr(inode, stat);
8078 stat->dev = BTRFS_I(inode)->root->anon_dev;
8079 stat->blksize = PAGE_CACHE_SIZE;
8080
8081 spin_lock(&BTRFS_I(inode)->lock);
8082 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
8083 spin_unlock(&BTRFS_I(inode)->lock);
8084 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
8085 ALIGN(delalloc_bytes, blocksize)) >> 9;
8086 return 0;
8087 }
8088
8089 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
8090 struct inode *new_dir, struct dentry *new_dentry)
8091 {
8092 struct btrfs_trans_handle *trans;
8093 struct btrfs_root *root = BTRFS_I(old_dir)->root;
8094 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
8095 struct inode *new_inode = new_dentry->d_inode;
8096 struct inode *old_inode = old_dentry->d_inode;
8097 struct timespec ctime = CURRENT_TIME;
8098 u64 index = 0;
8099 u64 root_objectid;
8100 int ret;
8101 u64 old_ino = btrfs_ino(old_inode);
8102
8103 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
8104 return -EPERM;
8105
8106 /* we only allow rename subvolume link between subvolumes */
8107 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
8108 return -EXDEV;
8109
8110 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
8111 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
8112 return -ENOTEMPTY;
8113
8114 if (S_ISDIR(old_inode->i_mode) && new_inode &&
8115 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
8116 return -ENOTEMPTY;
8117
8118
8119 /* check for collisions, even if the name isn't there */
8120 ret = btrfs_check_dir_item_collision(root, new_dir->i_ino,
8121 new_dentry->d_name.name,
8122 new_dentry->d_name.len);
8123
8124 if (ret) {
8125 if (ret == -EEXIST) {
8126 /* we shouldn't get
8127 * eexist without a new_inode */
8128 if (!new_inode) {
8129 WARN_ON(1);
8130 return ret;
8131 }
8132 } else {
8133 /* maybe -EOVERFLOW */
8134 return ret;
8135 }
8136 }
8137 ret = 0;
8138
8139 /*
8140 * we're using rename to replace one file with another.
8141 * and the replacement file is large. Start IO on it now so
8142 * we don't add too much work to the end of the transaction
8143 */
8144 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size &&
8145 old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
8146 filemap_flush(old_inode->i_mapping);
8147
8148 /* close the racy window with snapshot create/destroy ioctl */
8149 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
8150 down_read(&root->fs_info->subvol_sem);
8151 /*
8152 * We want to reserve the absolute worst case amount of items. So if
8153 * both inodes are subvols and we need to unlink them then that would
8154 * require 4 item modifications, but if they are both normal inodes it
8155 * would require 5 item modifications, so we'll assume their normal
8156 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
8157 * should cover the worst case number of items we'll modify.
8158 */
8159 trans = btrfs_start_transaction(root, 11);
8160 if (IS_ERR(trans)) {
8161 ret = PTR_ERR(trans);
8162 goto out_notrans;
8163 }
8164
8165 if (dest != root)
8166 btrfs_record_root_in_trans(trans, dest);
8167
8168 ret = btrfs_set_inode_index(new_dir, &index);
8169 if (ret)
8170 goto out_fail;
8171
8172 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
8173 /* force full log commit if subvolume involved. */
8174 root->fs_info->last_trans_log_full_commit = trans->transid;
8175 } else {
8176 ret = btrfs_insert_inode_ref(trans, dest,
8177 new_dentry->d_name.name,
8178 new_dentry->d_name.len,
8179 old_ino,
8180 btrfs_ino(new_dir), index);
8181 if (ret)
8182 goto out_fail;
8183 /*
8184 * this is an ugly little race, but the rename is required
8185 * to make sure that if we crash, the inode is either at the
8186 * old name or the new one. pinning the log transaction lets
8187 * us make sure we don't allow a log commit to come in after
8188 * we unlink the name but before we add the new name back in.
8189 */
8190 btrfs_pin_log_trans(root);
8191 }
8192 /*
8193 * make sure the inode gets flushed if it is replacing
8194 * something.
8195 */
8196 if (new_inode && new_inode->i_size && S_ISREG(old_inode->i_mode))
8197 btrfs_add_ordered_operation(trans, root, old_inode);
8198
8199 inode_inc_iversion(old_dir);
8200 inode_inc_iversion(new_dir);
8201 inode_inc_iversion(old_inode);
8202 old_dir->i_ctime = old_dir->i_mtime = ctime;
8203 new_dir->i_ctime = new_dir->i_mtime = ctime;
8204 old_inode->i_ctime = ctime;
8205
8206 if (old_dentry->d_parent != new_dentry->d_parent)
8207 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
8208
8209 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
8210 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
8211 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
8212 old_dentry->d_name.name,
8213 old_dentry->d_name.len);
8214 } else {
8215 ret = __btrfs_unlink_inode(trans, root, old_dir,
8216 old_dentry->d_inode,
8217 old_dentry->d_name.name,
8218 old_dentry->d_name.len);
8219 if (!ret)
8220 ret = btrfs_update_inode(trans, root, old_inode);
8221 }
8222 if (ret) {
8223 btrfs_abort_transaction(trans, root, ret);
8224 goto out_fail;
8225 }
8226
8227 if (new_inode) {
8228 inode_inc_iversion(new_inode);
8229 new_inode->i_ctime = CURRENT_TIME;
8230 if (unlikely(btrfs_ino(new_inode) ==
8231 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
8232 root_objectid = BTRFS_I(new_inode)->location.objectid;
8233 ret = btrfs_unlink_subvol(trans, dest, new_dir,
8234 root_objectid,
8235 new_dentry->d_name.name,
8236 new_dentry->d_name.len);
8237 BUG_ON(new_inode->i_nlink == 0);
8238 } else {
8239 ret = btrfs_unlink_inode(trans, dest, new_dir,
8240 new_dentry->d_inode,
8241 new_dentry->d_name.name,
8242 new_dentry->d_name.len);
8243 }
8244 if (!ret && new_inode->i_nlink == 0) {
8245 ret = btrfs_orphan_add(trans, new_dentry->d_inode);
8246 BUG_ON(ret);
8247 }
8248 if (ret) {
8249 btrfs_abort_transaction(trans, root, ret);
8250 goto out_fail;
8251 }
8252 }
8253
8254 ret = btrfs_add_link(trans, new_dir, old_inode,
8255 new_dentry->d_name.name,
8256 new_dentry->d_name.len, 0, index);
8257 if (ret) {
8258 btrfs_abort_transaction(trans, root, ret);
8259 goto out_fail;
8260 }
8261
8262 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
8263 struct dentry *parent = new_dentry->d_parent;
8264 btrfs_log_new_name(trans, old_inode, old_dir, parent);
8265 btrfs_end_log_trans(root);
8266 }
8267 out_fail:
8268 btrfs_end_transaction(trans, root);
8269 out_notrans:
8270 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
8271 up_read(&root->fs_info->subvol_sem);
8272
8273 return ret;
8274 }
8275
8276 static void btrfs_run_delalloc_work(struct btrfs_work *work)
8277 {
8278 struct btrfs_delalloc_work *delalloc_work;
8279
8280 delalloc_work = container_of(work, struct btrfs_delalloc_work,
8281 work);
8282 if (delalloc_work->wait)
8283 btrfs_wait_ordered_range(delalloc_work->inode, 0, (u64)-1);
8284 else
8285 filemap_flush(delalloc_work->inode->i_mapping);
8286
8287 if (delalloc_work->delay_iput)
8288 btrfs_add_delayed_iput(delalloc_work->inode);
8289 else
8290 iput(delalloc_work->inode);
8291 complete(&delalloc_work->completion);
8292 }
8293
8294 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
8295 int wait, int delay_iput)
8296 {
8297 struct btrfs_delalloc_work *work;
8298
8299 work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS);
8300 if (!work)
8301 return NULL;
8302
8303 init_completion(&work->completion);
8304 INIT_LIST_HEAD(&work->list);
8305 work->inode = inode;
8306 work->wait = wait;
8307 work->delay_iput = delay_iput;
8308 work->work.func = btrfs_run_delalloc_work;
8309
8310 return work;
8311 }
8312
8313 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
8314 {
8315 wait_for_completion(&work->completion);
8316 kmem_cache_free(btrfs_delalloc_work_cachep, work);
8317 }
8318
8319 /*
8320 * some fairly slow code that needs optimization. This walks the list
8321 * of all the inodes with pending delalloc and forces them to disk.
8322 */
8323 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
8324 {
8325 struct btrfs_inode *binode;
8326 struct inode *inode;
8327 struct btrfs_delalloc_work *work, *next;
8328 struct list_head works;
8329 struct list_head splice;
8330 int ret = 0;
8331
8332 if (root->fs_info->sb->s_flags & MS_RDONLY)
8333 return -EROFS;
8334
8335 INIT_LIST_HEAD(&works);
8336 INIT_LIST_HEAD(&splice);
8337
8338 spin_lock(&root->fs_info->delalloc_lock);
8339 list_splice_init(&root->fs_info->delalloc_inodes, &splice);
8340 while (!list_empty(&splice)) {
8341 binode = list_entry(splice.next, struct btrfs_inode,
8342 delalloc_inodes);
8343
8344 list_del_init(&binode->delalloc_inodes);
8345
8346 inode = igrab(&binode->vfs_inode);
8347 if (!inode) {
8348 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
8349 &binode->runtime_flags);
8350 continue;
8351 }
8352
8353 list_add_tail(&binode->delalloc_inodes,
8354 &root->fs_info->delalloc_inodes);
8355 spin_unlock(&root->fs_info->delalloc_lock);
8356
8357 work = btrfs_alloc_delalloc_work(inode, 0, delay_iput);
8358 if (unlikely(!work)) {
8359 ret = -ENOMEM;
8360 goto out;
8361 }
8362 list_add_tail(&work->list, &works);
8363 btrfs_queue_worker(&root->fs_info->flush_workers,
8364 &work->work);
8365
8366 cond_resched();
8367 spin_lock(&root->fs_info->delalloc_lock);
8368 }
8369 spin_unlock(&root->fs_info->delalloc_lock);
8370
8371 list_for_each_entry_safe(work, next, &works, list) {
8372 list_del_init(&work->list);
8373 btrfs_wait_and_free_delalloc_work(work);
8374 }
8375
8376 /* the filemap_flush will queue IO into the worker threads, but
8377 * we have to make sure the IO is actually started and that
8378 * ordered extents get created before we return
8379 */
8380 atomic_inc(&root->fs_info->async_submit_draining);
8381 while (atomic_read(&root->fs_info->nr_async_submits) ||
8382 atomic_read(&root->fs_info->async_delalloc_pages)) {
8383 wait_event(root->fs_info->async_submit_wait,
8384 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
8385 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
8386 }
8387 atomic_dec(&root->fs_info->async_submit_draining);
8388 return 0;
8389 out:
8390 list_for_each_entry_safe(work, next, &works, list) {
8391 list_del_init(&work->list);
8392 btrfs_wait_and_free_delalloc_work(work);
8393 }
8394
8395 if (!list_empty_careful(&splice)) {
8396 spin_lock(&root->fs_info->delalloc_lock);
8397 list_splice_tail(&splice, &root->fs_info->delalloc_inodes);
8398 spin_unlock(&root->fs_info->delalloc_lock);
8399 }
8400 return ret;
8401 }
8402
8403 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
8404 const char *symname)
8405 {
8406 struct btrfs_trans_handle *trans;
8407 struct btrfs_root *root = BTRFS_I(dir)->root;
8408 struct btrfs_path *path;
8409 struct btrfs_key key;
8410 struct inode *inode = NULL;
8411 int err;
8412 int drop_inode = 0;
8413 u64 objectid;
8414 u64 index = 0 ;
8415 int name_len;
8416 int datasize;
8417 unsigned long ptr;
8418 struct btrfs_file_extent_item *ei;
8419 struct extent_buffer *leaf;
8420
8421 name_len = strlen(symname) + 1;
8422 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
8423 return -ENAMETOOLONG;
8424
8425 /*
8426 * 2 items for inode item and ref
8427 * 2 items for dir items
8428 * 1 item for xattr if selinux is on
8429 */
8430 trans = btrfs_start_transaction(root, 5);
8431 if (IS_ERR(trans))
8432 return PTR_ERR(trans);
8433
8434 err = btrfs_find_free_ino(root, &objectid);
8435 if (err)
8436 goto out_unlock;
8437
8438 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
8439 dentry->d_name.len, btrfs_ino(dir), objectid,
8440 S_IFLNK|S_IRWXUGO, &index);
8441 if (IS_ERR(inode)) {
8442 err = PTR_ERR(inode);
8443 goto out_unlock;
8444 }
8445
8446 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
8447 if (err) {
8448 drop_inode = 1;
8449 goto out_unlock;
8450 }
8451
8452 /*
8453 * If the active LSM wants to access the inode during
8454 * d_instantiate it needs these. Smack checks to see
8455 * if the filesystem supports xattrs by looking at the
8456 * ops vector.
8457 */
8458 inode->i_fop = &btrfs_file_operations;
8459 inode->i_op = &btrfs_file_inode_operations;
8460
8461 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
8462 if (err)
8463 drop_inode = 1;
8464 else {
8465 inode->i_mapping->a_ops = &btrfs_aops;
8466 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
8467 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
8468 }
8469 if (drop_inode)
8470 goto out_unlock;
8471
8472 path = btrfs_alloc_path();
8473 if (!path) {
8474 err = -ENOMEM;
8475 drop_inode = 1;
8476 goto out_unlock;
8477 }
8478 key.objectid = btrfs_ino(inode);
8479 key.offset = 0;
8480 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
8481 datasize = btrfs_file_extent_calc_inline_size(name_len);
8482 err = btrfs_insert_empty_item(trans, root, path, &key,
8483 datasize);
8484 if (err) {
8485 drop_inode = 1;
8486 btrfs_free_path(path);
8487 goto out_unlock;
8488 }
8489 leaf = path->nodes[0];
8490 ei = btrfs_item_ptr(leaf, path->slots[0],
8491 struct btrfs_file_extent_item);
8492 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
8493 btrfs_set_file_extent_type(leaf, ei,
8494 BTRFS_FILE_EXTENT_INLINE);
8495 btrfs_set_file_extent_encryption(leaf, ei, 0);
8496 btrfs_set_file_extent_compression(leaf, ei, 0);
8497 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
8498 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
8499
8500 ptr = btrfs_file_extent_inline_start(ei);
8501 write_extent_buffer(leaf, symname, ptr, name_len);
8502 btrfs_mark_buffer_dirty(leaf);
8503 btrfs_free_path(path);
8504
8505 inode->i_op = &btrfs_symlink_inode_operations;
8506 inode->i_mapping->a_ops = &btrfs_symlink_aops;
8507 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
8508 inode_set_bytes(inode, name_len);
8509 btrfs_i_size_write(inode, name_len - 1);
8510 err = btrfs_update_inode(trans, root, inode);
8511 if (err)
8512 drop_inode = 1;
8513
8514 out_unlock:
8515 if (!err)
8516 d_instantiate(dentry, inode);
8517 btrfs_end_transaction(trans, root);
8518 if (drop_inode) {
8519 inode_dec_link_count(inode);
8520 iput(inode);
8521 }
8522 btrfs_btree_balance_dirty(root);
8523 return err;
8524 }
8525
8526 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
8527 u64 start, u64 num_bytes, u64 min_size,
8528 loff_t actual_len, u64 *alloc_hint,
8529 struct btrfs_trans_handle *trans)
8530 {
8531 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
8532 struct extent_map *em;
8533 struct btrfs_root *root = BTRFS_I(inode)->root;
8534 struct btrfs_key ins;
8535 u64 cur_offset = start;
8536 u64 i_size;
8537 u64 cur_bytes;
8538 int ret = 0;
8539 bool own_trans = true;
8540
8541 if (trans)
8542 own_trans = false;
8543 while (num_bytes > 0) {
8544 if (own_trans) {
8545 trans = btrfs_start_transaction(root, 3);
8546 if (IS_ERR(trans)) {
8547 ret = PTR_ERR(trans);
8548 break;
8549 }
8550 }
8551
8552 cur_bytes = min(num_bytes, 256ULL * 1024 * 1024);
8553 cur_bytes = max(cur_bytes, min_size);
8554 ret = btrfs_reserve_extent(trans, root, cur_bytes,
8555 min_size, 0, *alloc_hint, &ins, 1);
8556 if (ret) {
8557 if (own_trans)
8558 btrfs_end_transaction(trans, root);
8559 break;
8560 }
8561
8562 ret = insert_reserved_file_extent(trans, inode,
8563 cur_offset, ins.objectid,
8564 ins.offset, ins.offset,
8565 ins.offset, 0, 0, 0,
8566 BTRFS_FILE_EXTENT_PREALLOC);
8567 if (ret) {
8568 btrfs_abort_transaction(trans, root, ret);
8569 if (own_trans)
8570 btrfs_end_transaction(trans, root);
8571 break;
8572 }
8573 btrfs_drop_extent_cache(inode, cur_offset,
8574 cur_offset + ins.offset -1, 0);
8575
8576 em = alloc_extent_map();
8577 if (!em) {
8578 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
8579 &BTRFS_I(inode)->runtime_flags);
8580 goto next;
8581 }
8582
8583 em->start = cur_offset;
8584 em->orig_start = cur_offset;
8585 em->len = ins.offset;
8586 em->block_start = ins.objectid;
8587 em->block_len = ins.offset;
8588 em->orig_block_len = ins.offset;
8589 em->ram_bytes = ins.offset;
8590 em->bdev = root->fs_info->fs_devices->latest_bdev;
8591 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
8592 em->generation = trans->transid;
8593
8594 while (1) {
8595 write_lock(&em_tree->lock);
8596 ret = add_extent_mapping(em_tree, em);
8597 if (!ret)
8598 list_move(&em->list,
8599 &em_tree->modified_extents);
8600 write_unlock(&em_tree->lock);
8601 if (ret != -EEXIST)
8602 break;
8603 btrfs_drop_extent_cache(inode, cur_offset,
8604 cur_offset + ins.offset - 1,
8605 0);
8606 }
8607 free_extent_map(em);
8608 next:
8609 num_bytes -= ins.offset;
8610 cur_offset += ins.offset;
8611 *alloc_hint = ins.objectid + ins.offset;
8612
8613 inode_inc_iversion(inode);
8614 inode->i_ctime = CURRENT_TIME;
8615 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
8616 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
8617 (actual_len > inode->i_size) &&
8618 (cur_offset > inode->i_size)) {
8619 if (cur_offset > actual_len)
8620 i_size = actual_len;
8621 else
8622 i_size = cur_offset;
8623 i_size_write(inode, i_size);
8624 btrfs_ordered_update_i_size(inode, i_size, NULL);
8625 }
8626
8627 ret = btrfs_update_inode(trans, root, inode);
8628
8629 if (ret) {
8630 btrfs_abort_transaction(trans, root, ret);
8631 if (own_trans)
8632 btrfs_end_transaction(trans, root);
8633 break;
8634 }
8635
8636 if (own_trans)
8637 btrfs_end_transaction(trans, root);
8638 }
8639 return ret;
8640 }
8641
8642 int btrfs_prealloc_file_range(struct inode *inode, int mode,
8643 u64 start, u64 num_bytes, u64 min_size,
8644 loff_t actual_len, u64 *alloc_hint)
8645 {
8646 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
8647 min_size, actual_len, alloc_hint,
8648 NULL);
8649 }
8650
8651 int btrfs_prealloc_file_range_trans(struct inode *inode,
8652 struct btrfs_trans_handle *trans, int mode,
8653 u64 start, u64 num_bytes, u64 min_size,
8654 loff_t actual_len, u64 *alloc_hint)
8655 {
8656 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
8657 min_size, actual_len, alloc_hint, trans);
8658 }
8659
8660 static int btrfs_set_page_dirty(struct page *page)
8661 {
8662 return __set_page_dirty_nobuffers(page);
8663 }
8664
8665 static int btrfs_permission(struct inode *inode, int mask)
8666 {
8667 struct btrfs_root *root = BTRFS_I(inode)->root;
8668 umode_t mode = inode->i_mode;
8669
8670 if (mask & MAY_WRITE &&
8671 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
8672 if (btrfs_root_readonly(root))
8673 return -EROFS;
8674 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
8675 return -EACCES;
8676 }
8677 return generic_permission(inode, mask);
8678 }
8679
8680 static const struct inode_operations btrfs_dir_inode_operations = {
8681 .getattr = btrfs_getattr,
8682 .lookup = btrfs_lookup,
8683 .create = btrfs_create,
8684 .unlink = btrfs_unlink,
8685 .link = btrfs_link,
8686 .mkdir = btrfs_mkdir,
8687 .rmdir = btrfs_rmdir,
8688 .rename = btrfs_rename,
8689 .symlink = btrfs_symlink,
8690 .setattr = btrfs_setattr,
8691 .mknod = btrfs_mknod,
8692 .setxattr = btrfs_setxattr,
8693 .getxattr = btrfs_getxattr,
8694 .listxattr = btrfs_listxattr,
8695 .removexattr = btrfs_removexattr,
8696 .permission = btrfs_permission,
8697 .get_acl = btrfs_get_acl,
8698 };
8699 static const struct inode_operations btrfs_dir_ro_inode_operations = {
8700 .lookup = btrfs_lookup,
8701 .permission = btrfs_permission,
8702 .get_acl = btrfs_get_acl,
8703 };
8704
8705 static const struct file_operations btrfs_dir_file_operations = {
8706 .llseek = generic_file_llseek,
8707 .read = generic_read_dir,
8708 .readdir = btrfs_real_readdir,
8709 .unlocked_ioctl = btrfs_ioctl,
8710 #ifdef CONFIG_COMPAT
8711 .compat_ioctl = btrfs_ioctl,
8712 #endif
8713 .release = btrfs_release_file,
8714 .fsync = btrfs_sync_file,
8715 };
8716
8717 static struct extent_io_ops btrfs_extent_io_ops = {
8718 .fill_delalloc = run_delalloc_range,
8719 .submit_bio_hook = btrfs_submit_bio_hook,
8720 .merge_bio_hook = btrfs_merge_bio_hook,
8721 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
8722 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
8723 .writepage_start_hook = btrfs_writepage_start_hook,
8724 .set_bit_hook = btrfs_set_bit_hook,
8725 .clear_bit_hook = btrfs_clear_bit_hook,
8726 .merge_extent_hook = btrfs_merge_extent_hook,
8727 .split_extent_hook = btrfs_split_extent_hook,
8728 };
8729
8730 /*
8731 * btrfs doesn't support the bmap operation because swapfiles
8732 * use bmap to make a mapping of extents in the file. They assume
8733 * these extents won't change over the life of the file and they
8734 * use the bmap result to do IO directly to the drive.
8735 *
8736 * the btrfs bmap call would return logical addresses that aren't
8737 * suitable for IO and they also will change frequently as COW
8738 * operations happen. So, swapfile + btrfs == corruption.
8739 *
8740 * For now we're avoiding this by dropping bmap.
8741 */
8742 static const struct address_space_operations btrfs_aops = {
8743 .readpage = btrfs_readpage,
8744 .writepage = btrfs_writepage,
8745 .writepages = btrfs_writepages,
8746 .readpages = btrfs_readpages,
8747 .direct_IO = btrfs_direct_IO,
8748 .invalidatepage = btrfs_invalidatepage,
8749 .releasepage = btrfs_releasepage,
8750 .set_page_dirty = btrfs_set_page_dirty,
8751 .error_remove_page = generic_error_remove_page,
8752 };
8753
8754 static const struct address_space_operations btrfs_symlink_aops = {
8755 .readpage = btrfs_readpage,
8756 .writepage = btrfs_writepage,
8757 .invalidatepage = btrfs_invalidatepage,
8758 .releasepage = btrfs_releasepage,
8759 };
8760
8761 static const struct inode_operations btrfs_file_inode_operations = {
8762 .getattr = btrfs_getattr,
8763 .setattr = btrfs_setattr,
8764 .setxattr = btrfs_setxattr,
8765 .getxattr = btrfs_getxattr,
8766 .listxattr = btrfs_listxattr,
8767 .removexattr = btrfs_removexattr,
8768 .permission = btrfs_permission,
8769 .fiemap = btrfs_fiemap,
8770 .get_acl = btrfs_get_acl,
8771 .update_time = btrfs_update_time,
8772 };
8773 static const struct inode_operations btrfs_special_inode_operations = {
8774 .getattr = btrfs_getattr,
8775 .setattr = btrfs_setattr,
8776 .permission = btrfs_permission,
8777 .setxattr = btrfs_setxattr,
8778 .getxattr = btrfs_getxattr,
8779 .listxattr = btrfs_listxattr,
8780 .removexattr = btrfs_removexattr,
8781 .get_acl = btrfs_get_acl,
8782 .update_time = btrfs_update_time,
8783 };
8784 static const struct inode_operations btrfs_symlink_inode_operations = {
8785 .readlink = generic_readlink,
8786 .follow_link = page_follow_link_light,
8787 .put_link = page_put_link,
8788 .getattr = btrfs_getattr,
8789 .setattr = btrfs_setattr,
8790 .permission = btrfs_permission,
8791 .setxattr = btrfs_setxattr,
8792 .getxattr = btrfs_getxattr,
8793 .listxattr = btrfs_listxattr,
8794 .removexattr = btrfs_removexattr,
8795 .get_acl = btrfs_get_acl,
8796 .update_time = btrfs_update_time,
8797 };
8798
8799 const struct dentry_operations btrfs_dentry_operations = {
8800 .d_delete = btrfs_dentry_delete,
8801 .d_release = btrfs_dentry_release,
8802 };
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