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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/compat.h>
34#include <linux/bit_spinlock.h>
35#include <linux/xattr.h>
36#include <linux/posix_acl.h>
37#include <linux/falloc.h>
38#include <linux/slab.h>
39#include <linux/ratelimit.h>
40#include <linux/mount.h>
41#include <linux/btrfs.h>
42#include <linux/blkdev.h>
43#include <linux/posix_acl_xattr.h>
44#include <linux/uio.h>
45#include <linux/magic.h>
46#include "ctree.h"
47#include "disk-io.h"
48#include "transaction.h"
49#include "btrfs_inode.h"
50#include "print-tree.h"
51#include "ordered-data.h"
52#include "xattr.h"
53#include "tree-log.h"
54#include "volumes.h"
55#include "compression.h"
56#include "locking.h"
57#include "free-space-cache.h"
58#include "inode-map.h"
59#include "backref.h"
60#include "hash.h"
61#include "props.h"
62#include "qgroup.h"
63#include "dedupe.h"
64
65struct btrfs_iget_args {
66 struct btrfs_key *location;
67 struct btrfs_root *root;
68};
69
70struct btrfs_dio_data {
71 u64 reserve;
72 u64 unsubmitted_oe_range_start;
73 u64 unsubmitted_oe_range_end;
74 int overwrite;
75};
76
77static const struct inode_operations btrfs_dir_inode_operations;
78static const struct inode_operations btrfs_symlink_inode_operations;
79static const struct inode_operations btrfs_dir_ro_inode_operations;
80static const struct inode_operations btrfs_special_inode_operations;
81static const struct inode_operations btrfs_file_inode_operations;
82static const struct address_space_operations btrfs_aops;
83static const struct address_space_operations btrfs_symlink_aops;
84static const struct file_operations btrfs_dir_file_operations;
85static const struct extent_io_ops btrfs_extent_io_ops;
86
87static struct kmem_cache *btrfs_inode_cachep;
88struct kmem_cache *btrfs_trans_handle_cachep;
89struct kmem_cache *btrfs_path_cachep;
90struct kmem_cache *btrfs_free_space_cachep;
91
92#define S_SHIFT 12
93static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
94 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
95 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
96 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
97 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
98 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
99 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
100 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
101};
102
103static int btrfs_setsize(struct inode *inode, struct iattr *attr);
104static int btrfs_truncate(struct inode *inode);
105static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
106static noinline int cow_file_range(struct inode *inode,
107 struct page *locked_page,
108 u64 start, u64 end, u64 delalloc_end,
109 int *page_started, unsigned long *nr_written,
110 int unlock, struct btrfs_dedupe_hash *hash);
111static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
112 u64 orig_start, u64 block_start,
113 u64 block_len, u64 orig_block_len,
114 u64 ram_bytes, int compress_type,
115 int type);
116
117static void __endio_write_update_ordered(struct inode *inode,
118 const u64 offset, const u64 bytes,
119 const bool uptodate);
120
121/*
122 * Cleanup all submitted ordered extents in specified range to handle errors
123 * from the fill_dellaloc() callback.
124 *
125 * NOTE: caller must ensure that when an error happens, it can not call
126 * extent_clear_unlock_delalloc() to clear both the bits EXTENT_DO_ACCOUNTING
127 * and EXTENT_DELALLOC simultaneously, because that causes the reserved metadata
128 * to be released, which we want to happen only when finishing the ordered
129 * extent (btrfs_finish_ordered_io()). Also note that the caller of the
130 * fill_delalloc() callback already does proper cleanup for the first page of
131 * the range, that is, it invokes the callback writepage_end_io_hook() for the
132 * range of the first page.
133 */
134static inline void btrfs_cleanup_ordered_extents(struct inode *inode,
135 const u64 offset,
136 const u64 bytes)
137{
138 unsigned long index = offset >> PAGE_SHIFT;
139 unsigned long end_index = (offset + bytes - 1) >> PAGE_SHIFT;
140 struct page *page;
141
142 while (index <= end_index) {
143 page = find_get_page(inode->i_mapping, index);
144 index++;
145 if (!page)
146 continue;
147 ClearPagePrivate2(page);
148 put_page(page);
149 }
150 return __endio_write_update_ordered(inode, offset + PAGE_SIZE,
151 bytes - PAGE_SIZE, false);
152}
153
154static int btrfs_dirty_inode(struct inode *inode);
155
156#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
157void btrfs_test_inode_set_ops(struct inode *inode)
158{
159 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
160}
161#endif
162
163static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
164 struct inode *inode, struct inode *dir,
165 const struct qstr *qstr)
166{
167 int err;
168
169 err = btrfs_init_acl(trans, inode, dir);
170 if (!err)
171 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
172 return err;
173}
174
175/*
176 * this does all the hard work for inserting an inline extent into
177 * the btree. The caller should have done a btrfs_drop_extents so that
178 * no overlapping inline items exist in the btree
179 */
180static int insert_inline_extent(struct btrfs_trans_handle *trans,
181 struct btrfs_path *path, int extent_inserted,
182 struct btrfs_root *root, struct inode *inode,
183 u64 start, size_t size, size_t compressed_size,
184 int compress_type,
185 struct page **compressed_pages)
186{
187 struct extent_buffer *leaf;
188 struct page *page = NULL;
189 char *kaddr;
190 unsigned long ptr;
191 struct btrfs_file_extent_item *ei;
192 int ret;
193 size_t cur_size = size;
194 unsigned long offset;
195
196 if (compressed_size && compressed_pages)
197 cur_size = compressed_size;
198
199 inode_add_bytes(inode, size);
200
201 if (!extent_inserted) {
202 struct btrfs_key key;
203 size_t datasize;
204
205 key.objectid = btrfs_ino(BTRFS_I(inode));
206 key.offset = start;
207 key.type = BTRFS_EXTENT_DATA_KEY;
208
209 datasize = btrfs_file_extent_calc_inline_size(cur_size);
210 path->leave_spinning = 1;
211 ret = btrfs_insert_empty_item(trans, root, path, &key,
212 datasize);
213 if (ret)
214 goto fail;
215 }
216 leaf = path->nodes[0];
217 ei = btrfs_item_ptr(leaf, path->slots[0],
218 struct btrfs_file_extent_item);
219 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
220 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
221 btrfs_set_file_extent_encryption(leaf, ei, 0);
222 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
223 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
224 ptr = btrfs_file_extent_inline_start(ei);
225
226 if (compress_type != BTRFS_COMPRESS_NONE) {
227 struct page *cpage;
228 int i = 0;
229 while (compressed_size > 0) {
230 cpage = compressed_pages[i];
231 cur_size = min_t(unsigned long, compressed_size,
232 PAGE_SIZE);
233
234 kaddr = kmap_atomic(cpage);
235 write_extent_buffer(leaf, kaddr, ptr, cur_size);
236 kunmap_atomic(kaddr);
237
238 i++;
239 ptr += cur_size;
240 compressed_size -= cur_size;
241 }
242 btrfs_set_file_extent_compression(leaf, ei,
243 compress_type);
244 } else {
245 page = find_get_page(inode->i_mapping,
246 start >> PAGE_SHIFT);
247 btrfs_set_file_extent_compression(leaf, ei, 0);
248 kaddr = kmap_atomic(page);
249 offset = start & (PAGE_SIZE - 1);
250 write_extent_buffer(leaf, kaddr + offset, ptr, size);
251 kunmap_atomic(kaddr);
252 put_page(page);
253 }
254 btrfs_mark_buffer_dirty(leaf);
255 btrfs_release_path(path);
256
257 /*
258 * we're an inline extent, so nobody can
259 * extend the file past i_size without locking
260 * a page we already have locked.
261 *
262 * We must do any isize and inode updates
263 * before we unlock the pages. Otherwise we
264 * could end up racing with unlink.
265 */
266 BTRFS_I(inode)->disk_i_size = inode->i_size;
267 ret = btrfs_update_inode(trans, root, inode);
268
269fail:
270 return ret;
271}
272
273
274/*
275 * conditionally insert an inline extent into the file. This
276 * does the checks required to make sure the data is small enough
277 * to fit as an inline extent.
278 */
279static noinline int cow_file_range_inline(struct btrfs_root *root,
280 struct inode *inode, u64 start,
281 u64 end, size_t compressed_size,
282 int compress_type,
283 struct page **compressed_pages)
284{
285 struct btrfs_fs_info *fs_info = root->fs_info;
286 struct btrfs_trans_handle *trans;
287 u64 isize = i_size_read(inode);
288 u64 actual_end = min(end + 1, isize);
289 u64 inline_len = actual_end - start;
290 u64 aligned_end = ALIGN(end, fs_info->sectorsize);
291 u64 data_len = inline_len;
292 int ret;
293 struct btrfs_path *path;
294 int extent_inserted = 0;
295 u32 extent_item_size;
296
297 if (compressed_size)
298 data_len = compressed_size;
299
300 if (start > 0 ||
301 actual_end > fs_info->sectorsize ||
302 data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) ||
303 (!compressed_size &&
304 (actual_end & (fs_info->sectorsize - 1)) == 0) ||
305 end + 1 < isize ||
306 data_len > fs_info->max_inline) {
307 return 1;
308 }
309
310 path = btrfs_alloc_path();
311 if (!path)
312 return -ENOMEM;
313
314 trans = btrfs_join_transaction(root);
315 if (IS_ERR(trans)) {
316 btrfs_free_path(path);
317 return PTR_ERR(trans);
318 }
319 trans->block_rsv = &BTRFS_I(inode)->block_rsv;
320
321 if (compressed_size && compressed_pages)
322 extent_item_size = btrfs_file_extent_calc_inline_size(
323 compressed_size);
324 else
325 extent_item_size = btrfs_file_extent_calc_inline_size(
326 inline_len);
327
328 ret = __btrfs_drop_extents(trans, root, inode, path,
329 start, aligned_end, NULL,
330 1, 1, extent_item_size, &extent_inserted);
331 if (ret) {
332 btrfs_abort_transaction(trans, ret);
333 goto out;
334 }
335
336 if (isize > actual_end)
337 inline_len = min_t(u64, isize, actual_end);
338 ret = insert_inline_extent(trans, path, extent_inserted,
339 root, inode, start,
340 inline_len, compressed_size,
341 compress_type, compressed_pages);
342 if (ret && ret != -ENOSPC) {
343 btrfs_abort_transaction(trans, ret);
344 goto out;
345 } else if (ret == -ENOSPC) {
346 ret = 1;
347 goto out;
348 }
349
350 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
351 btrfs_drop_extent_cache(BTRFS_I(inode), start, aligned_end - 1, 0);
352out:
353 /*
354 * Don't forget to free the reserved space, as for inlined extent
355 * it won't count as data extent, free them directly here.
356 * And at reserve time, it's always aligned to page size, so
357 * just free one page here.
358 */
359 btrfs_qgroup_free_data(inode, NULL, 0, PAGE_SIZE);
360 btrfs_free_path(path);
361 btrfs_end_transaction(trans);
362 return ret;
363}
364
365struct async_extent {
366 u64 start;
367 u64 ram_size;
368 u64 compressed_size;
369 struct page **pages;
370 unsigned long nr_pages;
371 int compress_type;
372 struct list_head list;
373};
374
375struct async_cow {
376 struct inode *inode;
377 struct btrfs_root *root;
378 struct page *locked_page;
379 u64 start;
380 u64 end;
381 unsigned int write_flags;
382 struct list_head extents;
383 struct btrfs_work work;
384};
385
386static noinline int add_async_extent(struct async_cow *cow,
387 u64 start, u64 ram_size,
388 u64 compressed_size,
389 struct page **pages,
390 unsigned long nr_pages,
391 int compress_type)
392{
393 struct async_extent *async_extent;
394
395 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
396 BUG_ON(!async_extent); /* -ENOMEM */
397 async_extent->start = start;
398 async_extent->ram_size = ram_size;
399 async_extent->compressed_size = compressed_size;
400 async_extent->pages = pages;
401 async_extent->nr_pages = nr_pages;
402 async_extent->compress_type = compress_type;
403 list_add_tail(&async_extent->list, &cow->extents);
404 return 0;
405}
406
407static inline int inode_need_compress(struct inode *inode, u64 start, u64 end)
408{
409 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
410
411 /* force compress */
412 if (btrfs_test_opt(fs_info, FORCE_COMPRESS))
413 return 1;
414 /* defrag ioctl */
415 if (BTRFS_I(inode)->defrag_compress)
416 return 1;
417 /* bad compression ratios */
418 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
419 return 0;
420 if (btrfs_test_opt(fs_info, COMPRESS) ||
421 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
422 BTRFS_I(inode)->prop_compress)
423 return btrfs_compress_heuristic(inode, start, end);
424 return 0;
425}
426
427static inline void inode_should_defrag(struct btrfs_inode *inode,
428 u64 start, u64 end, u64 num_bytes, u64 small_write)
429{
430 /* If this is a small write inside eof, kick off a defrag */
431 if (num_bytes < small_write &&
432 (start > 0 || end + 1 < inode->disk_i_size))
433 btrfs_add_inode_defrag(NULL, inode);
434}
435
436/*
437 * we create compressed extents in two phases. The first
438 * phase compresses a range of pages that have already been
439 * locked (both pages and state bits are locked).
440 *
441 * This is done inside an ordered work queue, and the compression
442 * is spread across many cpus. The actual IO submission is step
443 * two, and the ordered work queue takes care of making sure that
444 * happens in the same order things were put onto the queue by
445 * writepages and friends.
446 *
447 * If this code finds it can't get good compression, it puts an
448 * entry onto the work queue to write the uncompressed bytes. This
449 * makes sure that both compressed inodes and uncompressed inodes
450 * are written in the same order that the flusher thread sent them
451 * down.
452 */
453static noinline void compress_file_range(struct inode *inode,
454 struct page *locked_page,
455 u64 start, u64 end,
456 struct async_cow *async_cow,
457 int *num_added)
458{
459 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
460 struct btrfs_root *root = BTRFS_I(inode)->root;
461 u64 blocksize = fs_info->sectorsize;
462 u64 actual_end;
463 u64 isize = i_size_read(inode);
464 int ret = 0;
465 struct page **pages = NULL;
466 unsigned long nr_pages;
467 unsigned long total_compressed = 0;
468 unsigned long total_in = 0;
469 int i;
470 int will_compress;
471 int compress_type = fs_info->compress_type;
472 int redirty = 0;
473
474 inode_should_defrag(BTRFS_I(inode), start, end, end - start + 1,
475 SZ_16K);
476
477 actual_end = min_t(u64, isize, end + 1);
478again:
479 will_compress = 0;
480 nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
481 BUILD_BUG_ON((BTRFS_MAX_COMPRESSED % PAGE_SIZE) != 0);
482 nr_pages = min_t(unsigned long, nr_pages,
483 BTRFS_MAX_COMPRESSED / PAGE_SIZE);
484
485 /*
486 * we don't want to send crud past the end of i_size through
487 * compression, that's just a waste of CPU time. So, if the
488 * end of the file is before the start of our current
489 * requested range of bytes, we bail out to the uncompressed
490 * cleanup code that can deal with all of this.
491 *
492 * It isn't really the fastest way to fix things, but this is a
493 * very uncommon corner.
494 */
495 if (actual_end <= start)
496 goto cleanup_and_bail_uncompressed;
497
498 total_compressed = actual_end - start;
499
500 /*
501 * skip compression for a small file range(<=blocksize) that
502 * isn't an inline extent, since it doesn't save disk space at all.
503 */
504 if (total_compressed <= blocksize &&
505 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
506 goto cleanup_and_bail_uncompressed;
507
508 total_compressed = min_t(unsigned long, total_compressed,
509 BTRFS_MAX_UNCOMPRESSED);
510 total_in = 0;
511 ret = 0;
512
513 /*
514 * we do compression for mount -o compress and when the
515 * inode has not been flagged as nocompress. This flag can
516 * change at any time if we discover bad compression ratios.
517 */
518 if (inode_need_compress(inode, start, end)) {
519 WARN_ON(pages);
520 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
521 if (!pages) {
522 /* just bail out to the uncompressed code */
523 goto cont;
524 }
525
526 if (BTRFS_I(inode)->defrag_compress)
527 compress_type = BTRFS_I(inode)->defrag_compress;
528 else if (BTRFS_I(inode)->prop_compress)
529 compress_type = BTRFS_I(inode)->prop_compress;
530
531 /*
532 * we need to call clear_page_dirty_for_io on each
533 * page in the range. Otherwise applications with the file
534 * mmap'd can wander in and change the page contents while
535 * we are compressing them.
536 *
537 * If the compression fails for any reason, we set the pages
538 * dirty again later on.
539 */
540 extent_range_clear_dirty_for_io(inode, start, end);
541 redirty = 1;
542
543 /* Compression level is applied here and only here */
544 ret = btrfs_compress_pages(
545 compress_type | (fs_info->compress_level << 4),
546 inode->i_mapping, start,
547 pages,
548 &nr_pages,
549 &total_in,
550 &total_compressed);
551
552 if (!ret) {
553 unsigned long offset = total_compressed &
554 (PAGE_SIZE - 1);
555 struct page *page = pages[nr_pages - 1];
556 char *kaddr;
557
558 /* zero the tail end of the last page, we might be
559 * sending it down to disk
560 */
561 if (offset) {
562 kaddr = kmap_atomic(page);
563 memset(kaddr + offset, 0,
564 PAGE_SIZE - offset);
565 kunmap_atomic(kaddr);
566 }
567 will_compress = 1;
568 }
569 }
570cont:
571 if (start == 0) {
572 /* lets try to make an inline extent */
573 if (ret || total_in < actual_end) {
574 /* we didn't compress the entire range, try
575 * to make an uncompressed inline extent.
576 */
577 ret = cow_file_range_inline(root, inode, start, end,
578 0, BTRFS_COMPRESS_NONE, NULL);
579 } else {
580 /* try making a compressed inline extent */
581 ret = cow_file_range_inline(root, inode, start, end,
582 total_compressed,
583 compress_type, pages);
584 }
585 if (ret <= 0) {
586 unsigned long clear_flags = EXTENT_DELALLOC |
587 EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
588 EXTENT_DO_ACCOUNTING;
589 unsigned long page_error_op;
590
591 page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
592
593 /*
594 * inline extent creation worked or returned error,
595 * we don't need to create any more async work items.
596 * Unlock and free up our temp pages.
597 *
598 * We use DO_ACCOUNTING here because we need the
599 * delalloc_release_metadata to be done _after_ we drop
600 * our outstanding extent for clearing delalloc for this
601 * range.
602 */
603 extent_clear_unlock_delalloc(inode, start, end, end,
604 NULL, clear_flags,
605 PAGE_UNLOCK |
606 PAGE_CLEAR_DIRTY |
607 PAGE_SET_WRITEBACK |
608 page_error_op |
609 PAGE_END_WRITEBACK);
610 goto free_pages_out;
611 }
612 }
613
614 if (will_compress) {
615 /*
616 * we aren't doing an inline extent round the compressed size
617 * up to a block size boundary so the allocator does sane
618 * things
619 */
620 total_compressed = ALIGN(total_compressed, blocksize);
621
622 /*
623 * one last check to make sure the compression is really a
624 * win, compare the page count read with the blocks on disk,
625 * compression must free at least one sector size
626 */
627 total_in = ALIGN(total_in, PAGE_SIZE);
628 if (total_compressed + blocksize <= total_in) {
629 *num_added += 1;
630
631 /*
632 * The async work queues will take care of doing actual
633 * allocation on disk for these compressed pages, and
634 * will submit them to the elevator.
635 */
636 add_async_extent(async_cow, start, total_in,
637 total_compressed, pages, nr_pages,
638 compress_type);
639
640 if (start + total_in < end) {
641 start += total_in;
642 pages = NULL;
643 cond_resched();
644 goto again;
645 }
646 return;
647 }
648 }
649 if (pages) {
650 /*
651 * the compression code ran but failed to make things smaller,
652 * free any pages it allocated and our page pointer array
653 */
654 for (i = 0; i < nr_pages; i++) {
655 WARN_ON(pages[i]->mapping);
656 put_page(pages[i]);
657 }
658 kfree(pages);
659 pages = NULL;
660 total_compressed = 0;
661 nr_pages = 0;
662
663 /* flag the file so we don't compress in the future */
664 if (!btrfs_test_opt(fs_info, FORCE_COMPRESS) &&
665 !(BTRFS_I(inode)->prop_compress)) {
666 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
667 }
668 }
669cleanup_and_bail_uncompressed:
670 /*
671 * No compression, but we still need to write the pages in the file
672 * we've been given so far. redirty the locked page if it corresponds
673 * to our extent and set things up for the async work queue to run
674 * cow_file_range to do the normal delalloc dance.
675 */
676 if (page_offset(locked_page) >= start &&
677 page_offset(locked_page) <= end)
678 __set_page_dirty_nobuffers(locked_page);
679 /* unlocked later on in the async handlers */
680
681 if (redirty)
682 extent_range_redirty_for_io(inode, start, end);
683 add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0,
684 BTRFS_COMPRESS_NONE);
685 *num_added += 1;
686
687 return;
688
689free_pages_out:
690 for (i = 0; i < nr_pages; i++) {
691 WARN_ON(pages[i]->mapping);
692 put_page(pages[i]);
693 }
694 kfree(pages);
695}
696
697static void free_async_extent_pages(struct async_extent *async_extent)
698{
699 int i;
700
701 if (!async_extent->pages)
702 return;
703
704 for (i = 0; i < async_extent->nr_pages; i++) {
705 WARN_ON(async_extent->pages[i]->mapping);
706 put_page(async_extent->pages[i]);
707 }
708 kfree(async_extent->pages);
709 async_extent->nr_pages = 0;
710 async_extent->pages = NULL;
711}
712
713/*
714 * phase two of compressed writeback. This is the ordered portion
715 * of the code, which only gets called in the order the work was
716 * queued. We walk all the async extents created by compress_file_range
717 * and send them down to the disk.
718 */
719static noinline void submit_compressed_extents(struct inode *inode,
720 struct async_cow *async_cow)
721{
722 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
723 struct async_extent *async_extent;
724 u64 alloc_hint = 0;
725 struct btrfs_key ins;
726 struct extent_map *em;
727 struct btrfs_root *root = BTRFS_I(inode)->root;
728 struct extent_io_tree *io_tree;
729 int ret = 0;
730
731again:
732 while (!list_empty(&async_cow->extents)) {
733 async_extent = list_entry(async_cow->extents.next,
734 struct async_extent, list);
735 list_del(&async_extent->list);
736
737 io_tree = &BTRFS_I(inode)->io_tree;
738
739retry:
740 /* did the compression code fall back to uncompressed IO? */
741 if (!async_extent->pages) {
742 int page_started = 0;
743 unsigned long nr_written = 0;
744
745 lock_extent(io_tree, async_extent->start,
746 async_extent->start +
747 async_extent->ram_size - 1);
748
749 /* allocate blocks */
750 ret = cow_file_range(inode, async_cow->locked_page,
751 async_extent->start,
752 async_extent->start +
753 async_extent->ram_size - 1,
754 async_extent->start +
755 async_extent->ram_size - 1,
756 &page_started, &nr_written, 0,
757 NULL);
758
759 /* JDM XXX */
760
761 /*
762 * if page_started, cow_file_range inserted an
763 * inline extent and took care of all the unlocking
764 * and IO for us. Otherwise, we need to submit
765 * all those pages down to the drive.
766 */
767 if (!page_started && !ret)
768 extent_write_locked_range(io_tree,
769 inode, async_extent->start,
770 async_extent->start +
771 async_extent->ram_size - 1,
772 btrfs_get_extent,
773 WB_SYNC_ALL);
774 else if (ret)
775 unlock_page(async_cow->locked_page);
776 kfree(async_extent);
777 cond_resched();
778 continue;
779 }
780
781 lock_extent(io_tree, async_extent->start,
782 async_extent->start + async_extent->ram_size - 1);
783
784 ret = btrfs_reserve_extent(root, async_extent->ram_size,
785 async_extent->compressed_size,
786 async_extent->compressed_size,
787 0, alloc_hint, &ins, 1, 1);
788 if (ret) {
789 free_async_extent_pages(async_extent);
790
791 if (ret == -ENOSPC) {
792 unlock_extent(io_tree, async_extent->start,
793 async_extent->start +
794 async_extent->ram_size - 1);
795
796 /*
797 * we need to redirty the pages if we decide to
798 * fallback to uncompressed IO, otherwise we
799 * will not submit these pages down to lower
800 * layers.
801 */
802 extent_range_redirty_for_io(inode,
803 async_extent->start,
804 async_extent->start +
805 async_extent->ram_size - 1);
806
807 goto retry;
808 }
809 goto out_free;
810 }
811 /*
812 * here we're doing allocation and writeback of the
813 * compressed pages
814 */
815 em = create_io_em(inode, async_extent->start,
816 async_extent->ram_size, /* len */
817 async_extent->start, /* orig_start */
818 ins.objectid, /* block_start */
819 ins.offset, /* block_len */
820 ins.offset, /* orig_block_len */
821 async_extent->ram_size, /* ram_bytes */
822 async_extent->compress_type,
823 BTRFS_ORDERED_COMPRESSED);
824 if (IS_ERR(em))
825 /* ret value is not necessary due to void function */
826 goto out_free_reserve;
827 free_extent_map(em);
828
829 ret = btrfs_add_ordered_extent_compress(inode,
830 async_extent->start,
831 ins.objectid,
832 async_extent->ram_size,
833 ins.offset,
834 BTRFS_ORDERED_COMPRESSED,
835 async_extent->compress_type);
836 if (ret) {
837 btrfs_drop_extent_cache(BTRFS_I(inode),
838 async_extent->start,
839 async_extent->start +
840 async_extent->ram_size - 1, 0);
841 goto out_free_reserve;
842 }
843 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
844
845 /*
846 * clear dirty, set writeback and unlock the pages.
847 */
848 extent_clear_unlock_delalloc(inode, async_extent->start,
849 async_extent->start +
850 async_extent->ram_size - 1,
851 async_extent->start +
852 async_extent->ram_size - 1,
853 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
854 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
855 PAGE_SET_WRITEBACK);
856 if (btrfs_submit_compressed_write(inode,
857 async_extent->start,
858 async_extent->ram_size,
859 ins.objectid,
860 ins.offset, async_extent->pages,
861 async_extent->nr_pages,
862 async_cow->write_flags)) {
863 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
864 struct page *p = async_extent->pages[0];
865 const u64 start = async_extent->start;
866 const u64 end = start + async_extent->ram_size - 1;
867
868 p->mapping = inode->i_mapping;
869 tree->ops->writepage_end_io_hook(p, start, end,
870 NULL, 0);
871 p->mapping = NULL;
872 extent_clear_unlock_delalloc(inode, start, end, end,
873 NULL, 0,
874 PAGE_END_WRITEBACK |
875 PAGE_SET_ERROR);
876 free_async_extent_pages(async_extent);
877 }
878 alloc_hint = ins.objectid + ins.offset;
879 kfree(async_extent);
880 cond_resched();
881 }
882 return;
883out_free_reserve:
884 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
885 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
886out_free:
887 extent_clear_unlock_delalloc(inode, async_extent->start,
888 async_extent->start +
889 async_extent->ram_size - 1,
890 async_extent->start +
891 async_extent->ram_size - 1,
892 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
893 EXTENT_DELALLOC_NEW |
894 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
895 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
896 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
897 PAGE_SET_ERROR);
898 free_async_extent_pages(async_extent);
899 kfree(async_extent);
900 goto again;
901}
902
903static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
904 u64 num_bytes)
905{
906 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
907 struct extent_map *em;
908 u64 alloc_hint = 0;
909
910 read_lock(&em_tree->lock);
911 em = search_extent_mapping(em_tree, start, num_bytes);
912 if (em) {
913 /*
914 * if block start isn't an actual block number then find the
915 * first block in this inode and use that as a hint. If that
916 * block is also bogus then just don't worry about it.
917 */
918 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
919 free_extent_map(em);
920 em = search_extent_mapping(em_tree, 0, 0);
921 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
922 alloc_hint = em->block_start;
923 if (em)
924 free_extent_map(em);
925 } else {
926 alloc_hint = em->block_start;
927 free_extent_map(em);
928 }
929 }
930 read_unlock(&em_tree->lock);
931
932 return alloc_hint;
933}
934
935/*
936 * when extent_io.c finds a delayed allocation range in the file,
937 * the call backs end up in this code. The basic idea is to
938 * allocate extents on disk for the range, and create ordered data structs
939 * in ram to track those extents.
940 *
941 * locked_page is the page that writepage had locked already. We use
942 * it to make sure we don't do extra locks or unlocks.
943 *
944 * *page_started is set to one if we unlock locked_page and do everything
945 * required to start IO on it. It may be clean and already done with
946 * IO when we return.
947 */
948static noinline int cow_file_range(struct inode *inode,
949 struct page *locked_page,
950 u64 start, u64 end, u64 delalloc_end,
951 int *page_started, unsigned long *nr_written,
952 int unlock, struct btrfs_dedupe_hash *hash)
953{
954 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
955 struct btrfs_root *root = BTRFS_I(inode)->root;
956 u64 alloc_hint = 0;
957 u64 num_bytes;
958 unsigned long ram_size;
959 u64 disk_num_bytes;
960 u64 cur_alloc_size = 0;
961 u64 blocksize = fs_info->sectorsize;
962 struct btrfs_key ins;
963 struct extent_map *em;
964 unsigned clear_bits;
965 unsigned long page_ops;
966 bool extent_reserved = false;
967 int ret = 0;
968
969 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
970 WARN_ON_ONCE(1);
971 ret = -EINVAL;
972 goto out_unlock;
973 }
974
975 num_bytes = ALIGN(end - start + 1, blocksize);
976 num_bytes = max(blocksize, num_bytes);
977 disk_num_bytes = num_bytes;
978
979 inode_should_defrag(BTRFS_I(inode), start, end, num_bytes, SZ_64K);
980
981 if (start == 0) {
982 /* lets try to make an inline extent */
983 ret = cow_file_range_inline(root, inode, start, end, 0,
984 BTRFS_COMPRESS_NONE, NULL);
985 if (ret == 0) {
986 /*
987 * We use DO_ACCOUNTING here because we need the
988 * delalloc_release_metadata to be run _after_ we drop
989 * our outstanding extent for clearing delalloc for this
990 * range.
991 */
992 extent_clear_unlock_delalloc(inode, start, end,
993 delalloc_end, NULL,
994 EXTENT_LOCKED | EXTENT_DELALLOC |
995 EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
996 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
997 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
998 PAGE_END_WRITEBACK);
999 *nr_written = *nr_written +
1000 (end - start + PAGE_SIZE) / PAGE_SIZE;
1001 *page_started = 1;
1002 goto out;
1003 } else if (ret < 0) {
1004 goto out_unlock;
1005 }
1006 }
1007
1008 BUG_ON(disk_num_bytes >
1009 btrfs_super_total_bytes(fs_info->super_copy));
1010
1011 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
1012 btrfs_drop_extent_cache(BTRFS_I(inode), start,
1013 start + num_bytes - 1, 0);
1014
1015 while (disk_num_bytes > 0) {
1016 cur_alloc_size = disk_num_bytes;
1017 ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size,
1018 fs_info->sectorsize, 0, alloc_hint,
1019 &ins, 1, 1);
1020 if (ret < 0)
1021 goto out_unlock;
1022 cur_alloc_size = ins.offset;
1023 extent_reserved = true;
1024
1025 ram_size = ins.offset;
1026 em = create_io_em(inode, start, ins.offset, /* len */
1027 start, /* orig_start */
1028 ins.objectid, /* block_start */
1029 ins.offset, /* block_len */
1030 ins.offset, /* orig_block_len */
1031 ram_size, /* ram_bytes */
1032 BTRFS_COMPRESS_NONE, /* compress_type */
1033 BTRFS_ORDERED_REGULAR /* type */);
1034 if (IS_ERR(em))
1035 goto out_reserve;
1036 free_extent_map(em);
1037
1038 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
1039 ram_size, cur_alloc_size, 0);
1040 if (ret)
1041 goto out_drop_extent_cache;
1042
1043 if (root->root_key.objectid ==
1044 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1045 ret = btrfs_reloc_clone_csums(inode, start,
1046 cur_alloc_size);
1047 /*
1048 * Only drop cache here, and process as normal.
1049 *
1050 * We must not allow extent_clear_unlock_delalloc()
1051 * at out_unlock label to free meta of this ordered
1052 * extent, as its meta should be freed by
1053 * btrfs_finish_ordered_io().
1054 *
1055 * So we must continue until @start is increased to
1056 * skip current ordered extent.
1057 */
1058 if (ret)
1059 btrfs_drop_extent_cache(BTRFS_I(inode), start,
1060 start + ram_size - 1, 0);
1061 }
1062
1063 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1064
1065 /* we're not doing compressed IO, don't unlock the first
1066 * page (which the caller expects to stay locked), don't
1067 * clear any dirty bits and don't set any writeback bits
1068 *
1069 * Do set the Private2 bit so we know this page was properly
1070 * setup for writepage
1071 */
1072 page_ops = unlock ? PAGE_UNLOCK : 0;
1073 page_ops |= PAGE_SET_PRIVATE2;
1074
1075 extent_clear_unlock_delalloc(inode, start,
1076 start + ram_size - 1,
1077 delalloc_end, locked_page,
1078 EXTENT_LOCKED | EXTENT_DELALLOC,
1079 page_ops);
1080 if (disk_num_bytes < cur_alloc_size)
1081 disk_num_bytes = 0;
1082 else
1083 disk_num_bytes -= cur_alloc_size;
1084 num_bytes -= cur_alloc_size;
1085 alloc_hint = ins.objectid + ins.offset;
1086 start += cur_alloc_size;
1087 extent_reserved = false;
1088
1089 /*
1090 * btrfs_reloc_clone_csums() error, since start is increased
1091 * extent_clear_unlock_delalloc() at out_unlock label won't
1092 * free metadata of current ordered extent, we're OK to exit.
1093 */
1094 if (ret)
1095 goto out_unlock;
1096 }
1097out:
1098 return ret;
1099
1100out_drop_extent_cache:
1101 btrfs_drop_extent_cache(BTRFS_I(inode), start, start + ram_size - 1, 0);
1102out_reserve:
1103 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1104 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
1105out_unlock:
1106 clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
1107 EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV;
1108 page_ops = PAGE_UNLOCK | PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
1109 PAGE_END_WRITEBACK;
1110 /*
1111 * If we reserved an extent for our delalloc range (or a subrange) and
1112 * failed to create the respective ordered extent, then it means that
1113 * when we reserved the extent we decremented the extent's size from
1114 * the data space_info's bytes_may_use counter and incremented the
1115 * space_info's bytes_reserved counter by the same amount. We must make
1116 * sure extent_clear_unlock_delalloc() does not try to decrement again
1117 * the data space_info's bytes_may_use counter, therefore we do not pass
1118 * it the flag EXTENT_CLEAR_DATA_RESV.
1119 */
1120 if (extent_reserved) {
1121 extent_clear_unlock_delalloc(inode, start,
1122 start + cur_alloc_size,
1123 start + cur_alloc_size,
1124 locked_page,
1125 clear_bits,
1126 page_ops);
1127 start += cur_alloc_size;
1128 if (start >= end)
1129 goto out;
1130 }
1131 extent_clear_unlock_delalloc(inode, start, end, delalloc_end,
1132 locked_page,
1133 clear_bits | EXTENT_CLEAR_DATA_RESV,
1134 page_ops);
1135 goto out;
1136}
1137
1138/*
1139 * work queue call back to started compression on a file and pages
1140 */
1141static noinline void async_cow_start(struct btrfs_work *work)
1142{
1143 struct async_cow *async_cow;
1144 int num_added = 0;
1145 async_cow = container_of(work, struct async_cow, work);
1146
1147 compress_file_range(async_cow->inode, async_cow->locked_page,
1148 async_cow->start, async_cow->end, async_cow,
1149 &num_added);
1150 if (num_added == 0) {
1151 btrfs_add_delayed_iput(async_cow->inode);
1152 async_cow->inode = NULL;
1153 }
1154}
1155
1156/*
1157 * work queue call back to submit previously compressed pages
1158 */
1159static noinline void async_cow_submit(struct btrfs_work *work)
1160{
1161 struct btrfs_fs_info *fs_info;
1162 struct async_cow *async_cow;
1163 struct btrfs_root *root;
1164 unsigned long nr_pages;
1165
1166 async_cow = container_of(work, struct async_cow, work);
1167
1168 root = async_cow->root;
1169 fs_info = root->fs_info;
1170 nr_pages = (async_cow->end - async_cow->start + PAGE_SIZE) >>
1171 PAGE_SHIFT;
1172
1173 /*
1174 * atomic_sub_return implies a barrier for waitqueue_active
1175 */
1176 if (atomic_sub_return(nr_pages, &fs_info->async_delalloc_pages) <
1177 5 * SZ_1M &&
1178 waitqueue_active(&fs_info->async_submit_wait))
1179 wake_up(&fs_info->async_submit_wait);
1180
1181 if (async_cow->inode)
1182 submit_compressed_extents(async_cow->inode, async_cow);
1183}
1184
1185static noinline void async_cow_free(struct btrfs_work *work)
1186{
1187 struct async_cow *async_cow;
1188 async_cow = container_of(work, struct async_cow, work);
1189 if (async_cow->inode)
1190 btrfs_add_delayed_iput(async_cow->inode);
1191 kfree(async_cow);
1192}
1193
1194static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1195 u64 start, u64 end, int *page_started,
1196 unsigned long *nr_written,
1197 unsigned int write_flags)
1198{
1199 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1200 struct async_cow *async_cow;
1201 struct btrfs_root *root = BTRFS_I(inode)->root;
1202 unsigned long nr_pages;
1203 u64 cur_end;
1204
1205 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1206 1, 0, NULL, GFP_NOFS);
1207 while (start < end) {
1208 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1209 BUG_ON(!async_cow); /* -ENOMEM */
1210 async_cow->inode = igrab(inode);
1211 async_cow->root = root;
1212 async_cow->locked_page = locked_page;
1213 async_cow->start = start;
1214 async_cow->write_flags = write_flags;
1215
1216 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
1217 !btrfs_test_opt(fs_info, FORCE_COMPRESS))
1218 cur_end = end;
1219 else
1220 cur_end = min(end, start + SZ_512K - 1);
1221
1222 async_cow->end = cur_end;
1223 INIT_LIST_HEAD(&async_cow->extents);
1224
1225 btrfs_init_work(&async_cow->work,
1226 btrfs_delalloc_helper,
1227 async_cow_start, async_cow_submit,
1228 async_cow_free);
1229
1230 nr_pages = (cur_end - start + PAGE_SIZE) >>
1231 PAGE_SHIFT;
1232 atomic_add(nr_pages, &fs_info->async_delalloc_pages);
1233
1234 btrfs_queue_work(fs_info->delalloc_workers, &async_cow->work);
1235
1236 *nr_written += nr_pages;
1237 start = cur_end + 1;
1238 }
1239 *page_started = 1;
1240 return 0;
1241}
1242
1243static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info,
1244 u64 bytenr, u64 num_bytes)
1245{
1246 int ret;
1247 struct btrfs_ordered_sum *sums;
1248 LIST_HEAD(list);
1249
1250 ret = btrfs_lookup_csums_range(fs_info->csum_root, bytenr,
1251 bytenr + num_bytes - 1, &list, 0);
1252 if (ret == 0 && list_empty(&list))
1253 return 0;
1254
1255 while (!list_empty(&list)) {
1256 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1257 list_del(&sums->list);
1258 kfree(sums);
1259 }
1260 return 1;
1261}
1262
1263/*
1264 * when nowcow writeback call back. This checks for snapshots or COW copies
1265 * of the extents that exist in the file, and COWs the file as required.
1266 *
1267 * If no cow copies or snapshots exist, we write directly to the existing
1268 * blocks on disk
1269 */
1270static noinline int run_delalloc_nocow(struct inode *inode,
1271 struct page *locked_page,
1272 u64 start, u64 end, int *page_started, int force,
1273 unsigned long *nr_written)
1274{
1275 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1276 struct btrfs_root *root = BTRFS_I(inode)->root;
1277 struct extent_buffer *leaf;
1278 struct btrfs_path *path;
1279 struct btrfs_file_extent_item *fi;
1280 struct btrfs_key found_key;
1281 struct extent_map *em;
1282 u64 cow_start;
1283 u64 cur_offset;
1284 u64 extent_end;
1285 u64 extent_offset;
1286 u64 disk_bytenr;
1287 u64 num_bytes;
1288 u64 disk_num_bytes;
1289 u64 ram_bytes;
1290 int extent_type;
1291 int ret, err;
1292 int type;
1293 int nocow;
1294 int check_prev = 1;
1295 bool nolock;
1296 u64 ino = btrfs_ino(BTRFS_I(inode));
1297
1298 path = btrfs_alloc_path();
1299 if (!path) {
1300 extent_clear_unlock_delalloc(inode, start, end, end,
1301 locked_page,
1302 EXTENT_LOCKED | EXTENT_DELALLOC |
1303 EXTENT_DO_ACCOUNTING |
1304 EXTENT_DEFRAG, PAGE_UNLOCK |
1305 PAGE_CLEAR_DIRTY |
1306 PAGE_SET_WRITEBACK |
1307 PAGE_END_WRITEBACK);
1308 return -ENOMEM;
1309 }
1310
1311 nolock = btrfs_is_free_space_inode(BTRFS_I(inode));
1312
1313 cow_start = (u64)-1;
1314 cur_offset = start;
1315 while (1) {
1316 ret = btrfs_lookup_file_extent(NULL, root, path, ino,
1317 cur_offset, 0);
1318 if (ret < 0)
1319 goto error;
1320 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1321 leaf = path->nodes[0];
1322 btrfs_item_key_to_cpu(leaf, &found_key,
1323 path->slots[0] - 1);
1324 if (found_key.objectid == ino &&
1325 found_key.type == BTRFS_EXTENT_DATA_KEY)
1326 path->slots[0]--;
1327 }
1328 check_prev = 0;
1329next_slot:
1330 leaf = path->nodes[0];
1331 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1332 ret = btrfs_next_leaf(root, path);
1333 if (ret < 0)
1334 goto error;
1335 if (ret > 0)
1336 break;
1337 leaf = path->nodes[0];
1338 }
1339
1340 nocow = 0;
1341 disk_bytenr = 0;
1342 num_bytes = 0;
1343 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1344
1345 if (found_key.objectid > ino)
1346 break;
1347 if (WARN_ON_ONCE(found_key.objectid < ino) ||
1348 found_key.type < BTRFS_EXTENT_DATA_KEY) {
1349 path->slots[0]++;
1350 goto next_slot;
1351 }
1352 if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
1353 found_key.offset > end)
1354 break;
1355
1356 if (found_key.offset > cur_offset) {
1357 extent_end = found_key.offset;
1358 extent_type = 0;
1359 goto out_check;
1360 }
1361
1362 fi = btrfs_item_ptr(leaf, path->slots[0],
1363 struct btrfs_file_extent_item);
1364 extent_type = btrfs_file_extent_type(leaf, fi);
1365
1366 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1367 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1368 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1369 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1370 extent_offset = btrfs_file_extent_offset(leaf, fi);
1371 extent_end = found_key.offset +
1372 btrfs_file_extent_num_bytes(leaf, fi);
1373 disk_num_bytes =
1374 btrfs_file_extent_disk_num_bytes(leaf, fi);
1375 if (extent_end <= start) {
1376 path->slots[0]++;
1377 goto next_slot;
1378 }
1379 if (disk_bytenr == 0)
1380 goto out_check;
1381 if (btrfs_file_extent_compression(leaf, fi) ||
1382 btrfs_file_extent_encryption(leaf, fi) ||
1383 btrfs_file_extent_other_encoding(leaf, fi))
1384 goto out_check;
1385 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1386 goto out_check;
1387 if (btrfs_extent_readonly(fs_info, disk_bytenr))
1388 goto out_check;
1389 if (btrfs_cross_ref_exist(root, ino,
1390 found_key.offset -
1391 extent_offset, disk_bytenr))
1392 goto out_check;
1393 disk_bytenr += extent_offset;
1394 disk_bytenr += cur_offset - found_key.offset;
1395 num_bytes = min(end + 1, extent_end) - cur_offset;
1396 /*
1397 * if there are pending snapshots for this root,
1398 * we fall into common COW way.
1399 */
1400 if (!nolock) {
1401 err = btrfs_start_write_no_snapshotting(root);
1402 if (!err)
1403 goto out_check;
1404 }
1405 /*
1406 * force cow if csum exists in the range.
1407 * this ensure that csum for a given extent are
1408 * either valid or do not exist.
1409 */
1410 if (csum_exist_in_range(fs_info, disk_bytenr,
1411 num_bytes)) {
1412 if (!nolock)
1413 btrfs_end_write_no_snapshotting(root);
1414 goto out_check;
1415 }
1416 if (!btrfs_inc_nocow_writers(fs_info, disk_bytenr)) {
1417 if (!nolock)
1418 btrfs_end_write_no_snapshotting(root);
1419 goto out_check;
1420 }
1421 nocow = 1;
1422 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1423 extent_end = found_key.offset +
1424 btrfs_file_extent_inline_len(leaf,
1425 path->slots[0], fi);
1426 extent_end = ALIGN(extent_end,
1427 fs_info->sectorsize);
1428 } else {
1429 BUG_ON(1);
1430 }
1431out_check:
1432 if (extent_end <= start) {
1433 path->slots[0]++;
1434 if (!nolock && nocow)
1435 btrfs_end_write_no_snapshotting(root);
1436 if (nocow)
1437 btrfs_dec_nocow_writers(fs_info, disk_bytenr);
1438 goto next_slot;
1439 }
1440 if (!nocow) {
1441 if (cow_start == (u64)-1)
1442 cow_start = cur_offset;
1443 cur_offset = extent_end;
1444 if (cur_offset > end)
1445 break;
1446 path->slots[0]++;
1447 goto next_slot;
1448 }
1449
1450 btrfs_release_path(path);
1451 if (cow_start != (u64)-1) {
1452 ret = cow_file_range(inode, locked_page,
1453 cow_start, found_key.offset - 1,
1454 end, page_started, nr_written, 1,
1455 NULL);
1456 if (ret) {
1457 if (!nolock && nocow)
1458 btrfs_end_write_no_snapshotting(root);
1459 if (nocow)
1460 btrfs_dec_nocow_writers(fs_info,
1461 disk_bytenr);
1462 goto error;
1463 }
1464 cow_start = (u64)-1;
1465 }
1466
1467 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1468 u64 orig_start = found_key.offset - extent_offset;
1469
1470 em = create_io_em(inode, cur_offset, num_bytes,
1471 orig_start,
1472 disk_bytenr, /* block_start */
1473 num_bytes, /* block_len */
1474 disk_num_bytes, /* orig_block_len */
1475 ram_bytes, BTRFS_COMPRESS_NONE,
1476 BTRFS_ORDERED_PREALLOC);
1477 if (IS_ERR(em)) {
1478 if (!nolock && nocow)
1479 btrfs_end_write_no_snapshotting(root);
1480 if (nocow)
1481 btrfs_dec_nocow_writers(fs_info,
1482 disk_bytenr);
1483 ret = PTR_ERR(em);
1484 goto error;
1485 }
1486 free_extent_map(em);
1487 }
1488
1489 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1490 type = BTRFS_ORDERED_PREALLOC;
1491 } else {
1492 type = BTRFS_ORDERED_NOCOW;
1493 }
1494
1495 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1496 num_bytes, num_bytes, type);
1497 if (nocow)
1498 btrfs_dec_nocow_writers(fs_info, disk_bytenr);
1499 BUG_ON(ret); /* -ENOMEM */
1500
1501 if (root->root_key.objectid ==
1502 BTRFS_DATA_RELOC_TREE_OBJECTID)
1503 /*
1504 * Error handled later, as we must prevent
1505 * extent_clear_unlock_delalloc() in error handler
1506 * from freeing metadata of created ordered extent.
1507 */
1508 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1509 num_bytes);
1510
1511 extent_clear_unlock_delalloc(inode, cur_offset,
1512 cur_offset + num_bytes - 1, end,
1513 locked_page, EXTENT_LOCKED |
1514 EXTENT_DELALLOC |
1515 EXTENT_CLEAR_DATA_RESV,
1516 PAGE_UNLOCK | PAGE_SET_PRIVATE2);
1517
1518 if (!nolock && nocow)
1519 btrfs_end_write_no_snapshotting(root);
1520 cur_offset = extent_end;
1521
1522 /*
1523 * btrfs_reloc_clone_csums() error, now we're OK to call error
1524 * handler, as metadata for created ordered extent will only
1525 * be freed by btrfs_finish_ordered_io().
1526 */
1527 if (ret)
1528 goto error;
1529 if (cur_offset > end)
1530 break;
1531 }
1532 btrfs_release_path(path);
1533
1534 if (cur_offset <= end && cow_start == (u64)-1) {
1535 cow_start = cur_offset;
1536 cur_offset = end;
1537 }
1538
1539 if (cow_start != (u64)-1) {
1540 ret = cow_file_range(inode, locked_page, cow_start, end, end,
1541 page_started, nr_written, 1, NULL);
1542 if (ret)
1543 goto error;
1544 }
1545
1546error:
1547 if (ret && cur_offset < end)
1548 extent_clear_unlock_delalloc(inode, cur_offset, end, end,
1549 locked_page, EXTENT_LOCKED |
1550 EXTENT_DELALLOC | EXTENT_DEFRAG |
1551 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1552 PAGE_CLEAR_DIRTY |
1553 PAGE_SET_WRITEBACK |
1554 PAGE_END_WRITEBACK);
1555 btrfs_free_path(path);
1556 return ret;
1557}
1558
1559static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
1560{
1561
1562 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
1563 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
1564 return 0;
1565
1566 /*
1567 * @defrag_bytes is a hint value, no spinlock held here,
1568 * if is not zero, it means the file is defragging.
1569 * Force cow if given extent needs to be defragged.
1570 */
1571 if (BTRFS_I(inode)->defrag_bytes &&
1572 test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1573 EXTENT_DEFRAG, 0, NULL))
1574 return 1;
1575
1576 return 0;
1577}
1578
1579/*
1580 * extent_io.c call back to do delayed allocation processing
1581 */
1582static int run_delalloc_range(void *private_data, struct page *locked_page,
1583 u64 start, u64 end, int *page_started,
1584 unsigned long *nr_written,
1585 struct writeback_control *wbc)
1586{
1587 struct inode *inode = private_data;
1588 int ret;
1589 int force_cow = need_force_cow(inode, start, end);
1590 unsigned int write_flags = wbc_to_write_flags(wbc);
1591
1592 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
1593 ret = run_delalloc_nocow(inode, locked_page, start, end,
1594 page_started, 1, nr_written);
1595 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
1596 ret = run_delalloc_nocow(inode, locked_page, start, end,
1597 page_started, 0, nr_written);
1598 } else if (!inode_need_compress(inode, start, end)) {
1599 ret = cow_file_range(inode, locked_page, start, end, end,
1600 page_started, nr_written, 1, NULL);
1601 } else {
1602 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1603 &BTRFS_I(inode)->runtime_flags);
1604 ret = cow_file_range_async(inode, locked_page, start, end,
1605 page_started, nr_written,
1606 write_flags);
1607 }
1608 if (ret)
1609 btrfs_cleanup_ordered_extents(inode, start, end - start + 1);
1610 return ret;
1611}
1612
1613static void btrfs_split_extent_hook(void *private_data,
1614 struct extent_state *orig, u64 split)
1615{
1616 struct inode *inode = private_data;
1617 u64 size;
1618
1619 /* not delalloc, ignore it */
1620 if (!(orig->state & EXTENT_DELALLOC))
1621 return;
1622
1623 size = orig->end - orig->start + 1;
1624 if (size > BTRFS_MAX_EXTENT_SIZE) {
1625 u32 num_extents;
1626 u64 new_size;
1627
1628 /*
1629 * See the explanation in btrfs_merge_extent_hook, the same
1630 * applies here, just in reverse.
1631 */
1632 new_size = orig->end - split + 1;
1633 num_extents = count_max_extents(new_size);
1634 new_size = split - orig->start;
1635 num_extents += count_max_extents(new_size);
1636 if (count_max_extents(size) >= num_extents)
1637 return;
1638 }
1639
1640 spin_lock(&BTRFS_I(inode)->lock);
1641 btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
1642 spin_unlock(&BTRFS_I(inode)->lock);
1643}
1644
1645/*
1646 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1647 * extents so we can keep track of new extents that are just merged onto old
1648 * extents, such as when we are doing sequential writes, so we can properly
1649 * account for the metadata space we'll need.
1650 */
1651static void btrfs_merge_extent_hook(void *private_data,
1652 struct extent_state *new,
1653 struct extent_state *other)
1654{
1655 struct inode *inode = private_data;
1656 u64 new_size, old_size;
1657 u32 num_extents;
1658
1659 /* not delalloc, ignore it */
1660 if (!(other->state & EXTENT_DELALLOC))
1661 return;
1662
1663 if (new->start > other->start)
1664 new_size = new->end - other->start + 1;
1665 else
1666 new_size = other->end - new->start + 1;
1667
1668 /* we're not bigger than the max, unreserve the space and go */
1669 if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
1670 spin_lock(&BTRFS_I(inode)->lock);
1671 btrfs_mod_outstanding_extents(BTRFS_I(inode), -1);
1672 spin_unlock(&BTRFS_I(inode)->lock);
1673 return;
1674 }
1675
1676 /*
1677 * We have to add up either side to figure out how many extents were
1678 * accounted for before we merged into one big extent. If the number of
1679 * extents we accounted for is <= the amount we need for the new range
1680 * then we can return, otherwise drop. Think of it like this
1681 *
1682 * [ 4k][MAX_SIZE]
1683 *
1684 * So we've grown the extent by a MAX_SIZE extent, this would mean we
1685 * need 2 outstanding extents, on one side we have 1 and the other side
1686 * we have 1 so they are == and we can return. But in this case
1687 *
1688 * [MAX_SIZE+4k][MAX_SIZE+4k]
1689 *
1690 * Each range on their own accounts for 2 extents, but merged together
1691 * they are only 3 extents worth of accounting, so we need to drop in
1692 * this case.
1693 */
1694 old_size = other->end - other->start + 1;
1695 num_extents = count_max_extents(old_size);
1696 old_size = new->end - new->start + 1;
1697 num_extents += count_max_extents(old_size);
1698 if (count_max_extents(new_size) >= num_extents)
1699 return;
1700
1701 spin_lock(&BTRFS_I(inode)->lock);
1702 btrfs_mod_outstanding_extents(BTRFS_I(inode), -1);
1703 spin_unlock(&BTRFS_I(inode)->lock);
1704}
1705
1706static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1707 struct inode *inode)
1708{
1709 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1710
1711 spin_lock(&root->delalloc_lock);
1712 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1713 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1714 &root->delalloc_inodes);
1715 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1716 &BTRFS_I(inode)->runtime_flags);
1717 root->nr_delalloc_inodes++;
1718 if (root->nr_delalloc_inodes == 1) {
1719 spin_lock(&fs_info->delalloc_root_lock);
1720 BUG_ON(!list_empty(&root->delalloc_root));
1721 list_add_tail(&root->delalloc_root,
1722 &fs_info->delalloc_roots);
1723 spin_unlock(&fs_info->delalloc_root_lock);
1724 }
1725 }
1726 spin_unlock(&root->delalloc_lock);
1727}
1728
1729static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1730 struct btrfs_inode *inode)
1731{
1732 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1733
1734 spin_lock(&root->delalloc_lock);
1735 if (!list_empty(&inode->delalloc_inodes)) {
1736 list_del_init(&inode->delalloc_inodes);
1737 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1738 &inode->runtime_flags);
1739 root->nr_delalloc_inodes--;
1740 if (!root->nr_delalloc_inodes) {
1741 spin_lock(&fs_info->delalloc_root_lock);
1742 BUG_ON(list_empty(&root->delalloc_root));
1743 list_del_init(&root->delalloc_root);
1744 spin_unlock(&fs_info->delalloc_root_lock);
1745 }
1746 }
1747 spin_unlock(&root->delalloc_lock);
1748}
1749
1750/*
1751 * extent_io.c set_bit_hook, used to track delayed allocation
1752 * bytes in this file, and to maintain the list of inodes that
1753 * have pending delalloc work to be done.
1754 */
1755static void btrfs_set_bit_hook(void *private_data,
1756 struct extent_state *state, unsigned *bits)
1757{
1758 struct inode *inode = private_data;
1759
1760 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1761
1762 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
1763 WARN_ON(1);
1764 /*
1765 * set_bit and clear bit hooks normally require _irqsave/restore
1766 * but in this case, we are only testing for the DELALLOC
1767 * bit, which is only set or cleared with irqs on
1768 */
1769 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1770 struct btrfs_root *root = BTRFS_I(inode)->root;
1771 u64 len = state->end + 1 - state->start;
1772 u32 num_extents = count_max_extents(len);
1773 bool do_list = !btrfs_is_free_space_inode(BTRFS_I(inode));
1774
1775 spin_lock(&BTRFS_I(inode)->lock);
1776 btrfs_mod_outstanding_extents(BTRFS_I(inode), num_extents);
1777 spin_unlock(&BTRFS_I(inode)->lock);
1778
1779 /* For sanity tests */
1780 if (btrfs_is_testing(fs_info))
1781 return;
1782
1783 percpu_counter_add_batch(&fs_info->delalloc_bytes, len,
1784 fs_info->delalloc_batch);
1785 spin_lock(&BTRFS_I(inode)->lock);
1786 BTRFS_I(inode)->delalloc_bytes += len;
1787 if (*bits & EXTENT_DEFRAG)
1788 BTRFS_I(inode)->defrag_bytes += len;
1789 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1790 &BTRFS_I(inode)->runtime_flags))
1791 btrfs_add_delalloc_inodes(root, inode);
1792 spin_unlock(&BTRFS_I(inode)->lock);
1793 }
1794
1795 if (!(state->state & EXTENT_DELALLOC_NEW) &&
1796 (*bits & EXTENT_DELALLOC_NEW)) {
1797 spin_lock(&BTRFS_I(inode)->lock);
1798 BTRFS_I(inode)->new_delalloc_bytes += state->end + 1 -
1799 state->start;
1800 spin_unlock(&BTRFS_I(inode)->lock);
1801 }
1802}
1803
1804/*
1805 * extent_io.c clear_bit_hook, see set_bit_hook for why
1806 */
1807static void btrfs_clear_bit_hook(void *private_data,
1808 struct extent_state *state,
1809 unsigned *bits)
1810{
1811 struct btrfs_inode *inode = BTRFS_I((struct inode *)private_data);
1812 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1813 u64 len = state->end + 1 - state->start;
1814 u32 num_extents = count_max_extents(len);
1815
1816 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG)) {
1817 spin_lock(&inode->lock);
1818 inode->defrag_bytes -= len;
1819 spin_unlock(&inode->lock);
1820 }
1821
1822 /*
1823 * set_bit and clear bit hooks normally require _irqsave/restore
1824 * but in this case, we are only testing for the DELALLOC
1825 * bit, which is only set or cleared with irqs on
1826 */
1827 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1828 struct btrfs_root *root = inode->root;
1829 bool do_list = !btrfs_is_free_space_inode(inode);
1830
1831 spin_lock(&inode->lock);
1832 btrfs_mod_outstanding_extents(inode, -num_extents);
1833 spin_unlock(&inode->lock);
1834
1835 /*
1836 * We don't reserve metadata space for space cache inodes so we
1837 * don't need to call dellalloc_release_metadata if there is an
1838 * error.
1839 */
1840 if (*bits & EXTENT_CLEAR_META_RESV &&
1841 root != fs_info->tree_root)
1842 btrfs_delalloc_release_metadata(inode, len);
1843
1844 /* For sanity tests. */
1845 if (btrfs_is_testing(fs_info))
1846 return;
1847
1848 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID &&
1849 do_list && !(state->state & EXTENT_NORESERVE) &&
1850 (*bits & EXTENT_CLEAR_DATA_RESV))
1851 btrfs_free_reserved_data_space_noquota(
1852 &inode->vfs_inode,
1853 state->start, len);
1854
1855 percpu_counter_add_batch(&fs_info->delalloc_bytes, -len,
1856 fs_info->delalloc_batch);
1857 spin_lock(&inode->lock);
1858 inode->delalloc_bytes -= len;
1859 if (do_list && inode->delalloc_bytes == 0 &&
1860 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1861 &inode->runtime_flags))
1862 btrfs_del_delalloc_inode(root, inode);
1863 spin_unlock(&inode->lock);
1864 }
1865
1866 if ((state->state & EXTENT_DELALLOC_NEW) &&
1867 (*bits & EXTENT_DELALLOC_NEW)) {
1868 spin_lock(&inode->lock);
1869 ASSERT(inode->new_delalloc_bytes >= len);
1870 inode->new_delalloc_bytes -= len;
1871 spin_unlock(&inode->lock);
1872 }
1873}
1874
1875/*
1876 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1877 * we don't create bios that span stripes or chunks
1878 *
1879 * return 1 if page cannot be merged to bio
1880 * return 0 if page can be merged to bio
1881 * return error otherwise
1882 */
1883int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
1884 size_t size, struct bio *bio,
1885 unsigned long bio_flags)
1886{
1887 struct inode *inode = page->mapping->host;
1888 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1889 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1890 u64 length = 0;
1891 u64 map_length;
1892 int ret;
1893
1894 if (bio_flags & EXTENT_BIO_COMPRESSED)
1895 return 0;
1896
1897 length = bio->bi_iter.bi_size;
1898 map_length = length;
1899 ret = btrfs_map_block(fs_info, btrfs_op(bio), logical, &map_length,
1900 NULL, 0);
1901 if (ret < 0)
1902 return ret;
1903 if (map_length < length + size)
1904 return 1;
1905 return 0;
1906}
1907
1908/*
1909 * in order to insert checksums into the metadata in large chunks,
1910 * we wait until bio submission time. All the pages in the bio are
1911 * checksummed and sums are attached onto the ordered extent record.
1912 *
1913 * At IO completion time the cums attached on the ordered extent record
1914 * are inserted into the btree
1915 */
1916static blk_status_t __btrfs_submit_bio_start(void *private_data, struct bio *bio,
1917 int mirror_num, unsigned long bio_flags,
1918 u64 bio_offset)
1919{
1920 struct inode *inode = private_data;
1921 blk_status_t ret = 0;
1922
1923 ret = btrfs_csum_one_bio(inode, bio, 0, 0);
1924 BUG_ON(ret); /* -ENOMEM */
1925 return 0;
1926}
1927
1928/*
1929 * in order to insert checksums into the metadata in large chunks,
1930 * we wait until bio submission time. All the pages in the bio are
1931 * checksummed and sums are attached onto the ordered extent record.
1932 *
1933 * At IO completion time the cums attached on the ordered extent record
1934 * are inserted into the btree
1935 */
1936static blk_status_t __btrfs_submit_bio_done(void *private_data, struct bio *bio,
1937 int mirror_num, unsigned long bio_flags,
1938 u64 bio_offset)
1939{
1940 struct inode *inode = private_data;
1941 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1942 blk_status_t ret;
1943
1944 ret = btrfs_map_bio(fs_info, bio, mirror_num, 1);
1945 if (ret) {
1946 bio->bi_status = ret;
1947 bio_endio(bio);
1948 }
1949 return ret;
1950}
1951
1952/*
1953 * extent_io.c submission hook. This does the right thing for csum calculation
1954 * on write, or reading the csums from the tree before a read
1955 */
1956static blk_status_t btrfs_submit_bio_hook(void *private_data, struct bio *bio,
1957 int mirror_num, unsigned long bio_flags,
1958 u64 bio_offset)
1959{
1960 struct inode *inode = private_data;
1961 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1962 struct btrfs_root *root = BTRFS_I(inode)->root;
1963 enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
1964 blk_status_t ret = 0;
1965 int skip_sum;
1966 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1967
1968 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1969
1970 if (btrfs_is_free_space_inode(BTRFS_I(inode)))
1971 metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
1972
1973 if (bio_op(bio) != REQ_OP_WRITE) {
1974 ret = btrfs_bio_wq_end_io(fs_info, bio, metadata);
1975 if (ret)
1976 goto out;
1977
1978 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1979 ret = btrfs_submit_compressed_read(inode, bio,
1980 mirror_num,
1981 bio_flags);
1982 goto out;
1983 } else if (!skip_sum) {
1984 ret = btrfs_lookup_bio_sums(inode, bio, NULL);
1985 if (ret)
1986 goto out;
1987 }
1988 goto mapit;
1989 } else if (async && !skip_sum) {
1990 /* csum items have already been cloned */
1991 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1992 goto mapit;
1993 /* we're doing a write, do the async checksumming */
1994 ret = btrfs_wq_submit_bio(fs_info, bio, mirror_num, bio_flags,
1995 bio_offset, inode,
1996 __btrfs_submit_bio_start,
1997 __btrfs_submit_bio_done);
1998 goto out;
1999 } else if (!skip_sum) {
2000 ret = btrfs_csum_one_bio(inode, bio, 0, 0);
2001 if (ret)
2002 goto out;
2003 }
2004
2005mapit:
2006 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
2007
2008out:
2009 if (ret) {
2010 bio->bi_status = ret;
2011 bio_endio(bio);
2012 }
2013 return ret;
2014}
2015
2016/*
2017 * given a list of ordered sums record them in the inode. This happens
2018 * at IO completion time based on sums calculated at bio submission time.
2019 */
2020static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
2021 struct inode *inode, struct list_head *list)
2022{
2023 struct btrfs_ordered_sum *sum;
2024
2025 list_for_each_entry(sum, list, list) {
2026 trans->adding_csums = 1;
2027 btrfs_csum_file_blocks(trans,
2028 BTRFS_I(inode)->root->fs_info->csum_root, sum);
2029 trans->adding_csums = 0;
2030 }
2031 return 0;
2032}
2033
2034int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
2035 unsigned int extra_bits,
2036 struct extent_state **cached_state, int dedupe)
2037{
2038 WARN_ON((end & (PAGE_SIZE - 1)) == 0);
2039 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
2040 extra_bits, cached_state);
2041}
2042
2043/* see btrfs_writepage_start_hook for details on why this is required */
2044struct btrfs_writepage_fixup {
2045 struct page *page;
2046 struct btrfs_work work;
2047};
2048
2049static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
2050{
2051 struct btrfs_writepage_fixup *fixup;
2052 struct btrfs_ordered_extent *ordered;
2053 struct extent_state *cached_state = NULL;
2054 struct extent_changeset *data_reserved = NULL;
2055 struct page *page;
2056 struct inode *inode;
2057 u64 page_start;
2058 u64 page_end;
2059 int ret;
2060
2061 fixup = container_of(work, struct btrfs_writepage_fixup, work);
2062 page = fixup->page;
2063again:
2064 lock_page(page);
2065 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
2066 ClearPageChecked(page);
2067 goto out_page;
2068 }
2069
2070 inode = page->mapping->host;
2071 page_start = page_offset(page);
2072 page_end = page_offset(page) + PAGE_SIZE - 1;
2073
2074 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
2075 &cached_state);
2076
2077 /* already ordered? We're done */
2078 if (PagePrivate2(page))
2079 goto out;
2080
2081 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
2082 PAGE_SIZE);
2083 if (ordered) {
2084 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
2085 page_end, &cached_state, GFP_NOFS);
2086 unlock_page(page);
2087 btrfs_start_ordered_extent(inode, ordered, 1);
2088 btrfs_put_ordered_extent(ordered);
2089 goto again;
2090 }
2091
2092 ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
2093 PAGE_SIZE);
2094 if (ret) {
2095 mapping_set_error(page->mapping, ret);
2096 end_extent_writepage(page, ret, page_start, page_end);
2097 ClearPageChecked(page);
2098 goto out;
2099 }
2100
2101 btrfs_set_extent_delalloc(inode, page_start, page_end, 0, &cached_state,
2102 0);
2103 ClearPageChecked(page);
2104 set_page_dirty(page);
2105 btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
2106out:
2107 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
2108 &cached_state, GFP_NOFS);
2109out_page:
2110 unlock_page(page);
2111 put_page(page);
2112 kfree(fixup);
2113 extent_changeset_free(data_reserved);
2114}
2115
2116/*
2117 * There are a few paths in the higher layers of the kernel that directly
2118 * set the page dirty bit without asking the filesystem if it is a
2119 * good idea. This causes problems because we want to make sure COW
2120 * properly happens and the data=ordered rules are followed.
2121 *
2122 * In our case any range that doesn't have the ORDERED bit set
2123 * hasn't been properly setup for IO. We kick off an async process
2124 * to fix it up. The async helper will wait for ordered extents, set
2125 * the delalloc bit and make it safe to write the page.
2126 */
2127static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
2128{
2129 struct inode *inode = page->mapping->host;
2130 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2131 struct btrfs_writepage_fixup *fixup;
2132
2133 /* this page is properly in the ordered list */
2134 if (TestClearPagePrivate2(page))
2135 return 0;
2136
2137 if (PageChecked(page))
2138 return -EAGAIN;
2139
2140 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
2141 if (!fixup)
2142 return -EAGAIN;
2143
2144 SetPageChecked(page);
2145 get_page(page);
2146 btrfs_init_work(&fixup->work, btrfs_fixup_helper,
2147 btrfs_writepage_fixup_worker, NULL, NULL);
2148 fixup->page = page;
2149 btrfs_queue_work(fs_info->fixup_workers, &fixup->work);
2150 return -EBUSY;
2151}
2152
2153static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
2154 struct inode *inode, u64 file_pos,
2155 u64 disk_bytenr, u64 disk_num_bytes,
2156 u64 num_bytes, u64 ram_bytes,
2157 u8 compression, u8 encryption,
2158 u16 other_encoding, int extent_type)
2159{
2160 struct btrfs_root *root = BTRFS_I(inode)->root;
2161 struct btrfs_file_extent_item *fi;
2162 struct btrfs_path *path;
2163 struct extent_buffer *leaf;
2164 struct btrfs_key ins;
2165 u64 qg_released;
2166 int extent_inserted = 0;
2167 int ret;
2168
2169 path = btrfs_alloc_path();
2170 if (!path)
2171 return -ENOMEM;
2172
2173 /*
2174 * we may be replacing one extent in the tree with another.
2175 * The new extent is pinned in the extent map, and we don't want
2176 * to drop it from the cache until it is completely in the btree.
2177 *
2178 * So, tell btrfs_drop_extents to leave this extent in the cache.
2179 * the caller is expected to unpin it and allow it to be merged
2180 * with the others.
2181 */
2182 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
2183 file_pos + num_bytes, NULL, 0,
2184 1, sizeof(*fi), &extent_inserted);
2185 if (ret)
2186 goto out;
2187
2188 if (!extent_inserted) {
2189 ins.objectid = btrfs_ino(BTRFS_I(inode));
2190 ins.offset = file_pos;
2191 ins.type = BTRFS_EXTENT_DATA_KEY;
2192
2193 path->leave_spinning = 1;
2194 ret = btrfs_insert_empty_item(trans, root, path, &ins,
2195 sizeof(*fi));
2196 if (ret)
2197 goto out;
2198 }
2199 leaf = path->nodes[0];
2200 fi = btrfs_item_ptr(leaf, path->slots[0],
2201 struct btrfs_file_extent_item);
2202 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2203 btrfs_set_file_extent_type(leaf, fi, extent_type);
2204 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
2205 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
2206 btrfs_set_file_extent_offset(leaf, fi, 0);
2207 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2208 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
2209 btrfs_set_file_extent_compression(leaf, fi, compression);
2210 btrfs_set_file_extent_encryption(leaf, fi, encryption);
2211 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
2212
2213 btrfs_mark_buffer_dirty(leaf);
2214 btrfs_release_path(path);
2215
2216 inode_add_bytes(inode, num_bytes);
2217
2218 ins.objectid = disk_bytenr;
2219 ins.offset = disk_num_bytes;
2220 ins.type = BTRFS_EXTENT_ITEM_KEY;
2221
2222 /*
2223 * Release the reserved range from inode dirty range map, as it is
2224 * already moved into delayed_ref_head
2225 */
2226 ret = btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
2227 if (ret < 0)
2228 goto out;
2229 qg_released = ret;
2230 ret = btrfs_alloc_reserved_file_extent(trans, root,
2231 btrfs_ino(BTRFS_I(inode)),
2232 file_pos, qg_released, &ins);
2233out:
2234 btrfs_free_path(path);
2235
2236 return ret;
2237}
2238
2239/* snapshot-aware defrag */
2240struct sa_defrag_extent_backref {
2241 struct rb_node node;
2242 struct old_sa_defrag_extent *old;
2243 u64 root_id;
2244 u64 inum;
2245 u64 file_pos;
2246 u64 extent_offset;
2247 u64 num_bytes;
2248 u64 generation;
2249};
2250
2251struct old_sa_defrag_extent {
2252 struct list_head list;
2253 struct new_sa_defrag_extent *new;
2254
2255 u64 extent_offset;
2256 u64 bytenr;
2257 u64 offset;
2258 u64 len;
2259 int count;
2260};
2261
2262struct new_sa_defrag_extent {
2263 struct rb_root root;
2264 struct list_head head;
2265 struct btrfs_path *path;
2266 struct inode *inode;
2267 u64 file_pos;
2268 u64 len;
2269 u64 bytenr;
2270 u64 disk_len;
2271 u8 compress_type;
2272};
2273
2274static int backref_comp(struct sa_defrag_extent_backref *b1,
2275 struct sa_defrag_extent_backref *b2)
2276{
2277 if (b1->root_id < b2->root_id)
2278 return -1;
2279 else if (b1->root_id > b2->root_id)
2280 return 1;
2281
2282 if (b1->inum < b2->inum)
2283 return -1;
2284 else if (b1->inum > b2->inum)
2285 return 1;
2286
2287 if (b1->file_pos < b2->file_pos)
2288 return -1;
2289 else if (b1->file_pos > b2->file_pos)
2290 return 1;
2291
2292 /*
2293 * [------------------------------] ===> (a range of space)
2294 * |<--->| |<---->| =============> (fs/file tree A)
2295 * |<---------------------------->| ===> (fs/file tree B)
2296 *
2297 * A range of space can refer to two file extents in one tree while
2298 * refer to only one file extent in another tree.
2299 *
2300 * So we may process a disk offset more than one time(two extents in A)
2301 * and locate at the same extent(one extent in B), then insert two same
2302 * backrefs(both refer to the extent in B).
2303 */
2304 return 0;
2305}
2306
2307static void backref_insert(struct rb_root *root,
2308 struct sa_defrag_extent_backref *backref)
2309{
2310 struct rb_node **p = &root->rb_node;
2311 struct rb_node *parent = NULL;
2312 struct sa_defrag_extent_backref *entry;
2313 int ret;
2314
2315 while (*p) {
2316 parent = *p;
2317 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2318
2319 ret = backref_comp(backref, entry);
2320 if (ret < 0)
2321 p = &(*p)->rb_left;
2322 else
2323 p = &(*p)->rb_right;
2324 }
2325
2326 rb_link_node(&backref->node, parent, p);
2327 rb_insert_color(&backref->node, root);
2328}
2329
2330/*
2331 * Note the backref might has changed, and in this case we just return 0.
2332 */
2333static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2334 void *ctx)
2335{
2336 struct btrfs_file_extent_item *extent;
2337 struct old_sa_defrag_extent *old = ctx;
2338 struct new_sa_defrag_extent *new = old->new;
2339 struct btrfs_path *path = new->path;
2340 struct btrfs_key key;
2341 struct btrfs_root *root;
2342 struct sa_defrag_extent_backref *backref;
2343 struct extent_buffer *leaf;
2344 struct inode *inode = new->inode;
2345 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2346 int slot;
2347 int ret;
2348 u64 extent_offset;
2349 u64 num_bytes;
2350
2351 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2352 inum == btrfs_ino(BTRFS_I(inode)))
2353 return 0;
2354
2355 key.objectid = root_id;
2356 key.type = BTRFS_ROOT_ITEM_KEY;
2357 key.offset = (u64)-1;
2358
2359 root = btrfs_read_fs_root_no_name(fs_info, &key);
2360 if (IS_ERR(root)) {
2361 if (PTR_ERR(root) == -ENOENT)
2362 return 0;
2363 WARN_ON(1);
2364 btrfs_debug(fs_info, "inum=%llu, offset=%llu, root_id=%llu",
2365 inum, offset, root_id);
2366 return PTR_ERR(root);
2367 }
2368
2369 key.objectid = inum;
2370 key.type = BTRFS_EXTENT_DATA_KEY;
2371 if (offset > (u64)-1 << 32)
2372 key.offset = 0;
2373 else
2374 key.offset = offset;
2375
2376 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2377 if (WARN_ON(ret < 0))
2378 return ret;
2379 ret = 0;
2380
2381 while (1) {
2382 cond_resched();
2383
2384 leaf = path->nodes[0];
2385 slot = path->slots[0];
2386
2387 if (slot >= btrfs_header_nritems(leaf)) {
2388 ret = btrfs_next_leaf(root, path);
2389 if (ret < 0) {
2390 goto out;
2391 } else if (ret > 0) {
2392 ret = 0;
2393 goto out;
2394 }
2395 continue;
2396 }
2397
2398 path->slots[0]++;
2399
2400 btrfs_item_key_to_cpu(leaf, &key, slot);
2401
2402 if (key.objectid > inum)
2403 goto out;
2404
2405 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2406 continue;
2407
2408 extent = btrfs_item_ptr(leaf, slot,
2409 struct btrfs_file_extent_item);
2410
2411 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2412 continue;
2413
2414 /*
2415 * 'offset' refers to the exact key.offset,
2416 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2417 * (key.offset - extent_offset).
2418 */
2419 if (key.offset != offset)
2420 continue;
2421
2422 extent_offset = btrfs_file_extent_offset(leaf, extent);
2423 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2424
2425 if (extent_offset >= old->extent_offset + old->offset +
2426 old->len || extent_offset + num_bytes <=
2427 old->extent_offset + old->offset)
2428 continue;
2429 break;
2430 }
2431
2432 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2433 if (!backref) {
2434 ret = -ENOENT;
2435 goto out;
2436 }
2437
2438 backref->root_id = root_id;
2439 backref->inum = inum;
2440 backref->file_pos = offset;
2441 backref->num_bytes = num_bytes;
2442 backref->extent_offset = extent_offset;
2443 backref->generation = btrfs_file_extent_generation(leaf, extent);
2444 backref->old = old;
2445 backref_insert(&new->root, backref);
2446 old->count++;
2447out:
2448 btrfs_release_path(path);
2449 WARN_ON(ret);
2450 return ret;
2451}
2452
2453static noinline bool record_extent_backrefs(struct btrfs_path *path,
2454 struct new_sa_defrag_extent *new)
2455{
2456 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2457 struct old_sa_defrag_extent *old, *tmp;
2458 int ret;
2459
2460 new->path = path;
2461
2462 list_for_each_entry_safe(old, tmp, &new->head, list) {
2463 ret = iterate_inodes_from_logical(old->bytenr +
2464 old->extent_offset, fs_info,
2465 path, record_one_backref,
2466 old, false);
2467 if (ret < 0 && ret != -ENOENT)
2468 return false;
2469
2470 /* no backref to be processed for this extent */
2471 if (!old->count) {
2472 list_del(&old->list);
2473 kfree(old);
2474 }
2475 }
2476
2477 if (list_empty(&new->head))
2478 return false;
2479
2480 return true;
2481}
2482
2483static int relink_is_mergable(struct extent_buffer *leaf,
2484 struct btrfs_file_extent_item *fi,
2485 struct new_sa_defrag_extent *new)
2486{
2487 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2488 return 0;
2489
2490 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2491 return 0;
2492
2493 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2494 return 0;
2495
2496 if (btrfs_file_extent_encryption(leaf, fi) ||
2497 btrfs_file_extent_other_encoding(leaf, fi))
2498 return 0;
2499
2500 return 1;
2501}
2502
2503/*
2504 * Note the backref might has changed, and in this case we just return 0.
2505 */
2506static noinline int relink_extent_backref(struct btrfs_path *path,
2507 struct sa_defrag_extent_backref *prev,
2508 struct sa_defrag_extent_backref *backref)
2509{
2510 struct btrfs_file_extent_item *extent;
2511 struct btrfs_file_extent_item *item;
2512 struct btrfs_ordered_extent *ordered;
2513 struct btrfs_trans_handle *trans;
2514 struct btrfs_root *root;
2515 struct btrfs_key key;
2516 struct extent_buffer *leaf;
2517 struct old_sa_defrag_extent *old = backref->old;
2518 struct new_sa_defrag_extent *new = old->new;
2519 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2520 struct inode *inode;
2521 struct extent_state *cached = NULL;
2522 int ret = 0;
2523 u64 start;
2524 u64 len;
2525 u64 lock_start;
2526 u64 lock_end;
2527 bool merge = false;
2528 int index;
2529
2530 if (prev && prev->root_id == backref->root_id &&
2531 prev->inum == backref->inum &&
2532 prev->file_pos + prev->num_bytes == backref->file_pos)
2533 merge = true;
2534
2535 /* step 1: get root */
2536 key.objectid = backref->root_id;
2537 key.type = BTRFS_ROOT_ITEM_KEY;
2538 key.offset = (u64)-1;
2539
2540 index = srcu_read_lock(&fs_info->subvol_srcu);
2541
2542 root = btrfs_read_fs_root_no_name(fs_info, &key);
2543 if (IS_ERR(root)) {
2544 srcu_read_unlock(&fs_info->subvol_srcu, index);
2545 if (PTR_ERR(root) == -ENOENT)
2546 return 0;
2547 return PTR_ERR(root);
2548 }
2549
2550 if (btrfs_root_readonly(root)) {
2551 srcu_read_unlock(&fs_info->subvol_srcu, index);
2552 return 0;
2553 }
2554
2555 /* step 2: get inode */
2556 key.objectid = backref->inum;
2557 key.type = BTRFS_INODE_ITEM_KEY;
2558 key.offset = 0;
2559
2560 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2561 if (IS_ERR(inode)) {
2562 srcu_read_unlock(&fs_info->subvol_srcu, index);
2563 return 0;
2564 }
2565
2566 srcu_read_unlock(&fs_info->subvol_srcu, index);
2567
2568 /* step 3: relink backref */
2569 lock_start = backref->file_pos;
2570 lock_end = backref->file_pos + backref->num_bytes - 1;
2571 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2572 &cached);
2573
2574 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2575 if (ordered) {
2576 btrfs_put_ordered_extent(ordered);
2577 goto out_unlock;
2578 }
2579
2580 trans = btrfs_join_transaction(root);
2581 if (IS_ERR(trans)) {
2582 ret = PTR_ERR(trans);
2583 goto out_unlock;
2584 }
2585
2586 key.objectid = backref->inum;
2587 key.type = BTRFS_EXTENT_DATA_KEY;
2588 key.offset = backref->file_pos;
2589
2590 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2591 if (ret < 0) {
2592 goto out_free_path;
2593 } else if (ret > 0) {
2594 ret = 0;
2595 goto out_free_path;
2596 }
2597
2598 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2599 struct btrfs_file_extent_item);
2600
2601 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2602 backref->generation)
2603 goto out_free_path;
2604
2605 btrfs_release_path(path);
2606
2607 start = backref->file_pos;
2608 if (backref->extent_offset < old->extent_offset + old->offset)
2609 start += old->extent_offset + old->offset -
2610 backref->extent_offset;
2611
2612 len = min(backref->extent_offset + backref->num_bytes,
2613 old->extent_offset + old->offset + old->len);
2614 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2615
2616 ret = btrfs_drop_extents(trans, root, inode, start,
2617 start + len, 1);
2618 if (ret)
2619 goto out_free_path;
2620again:
2621 key.objectid = btrfs_ino(BTRFS_I(inode));
2622 key.type = BTRFS_EXTENT_DATA_KEY;
2623 key.offset = start;
2624
2625 path->leave_spinning = 1;
2626 if (merge) {
2627 struct btrfs_file_extent_item *fi;
2628 u64 extent_len;
2629 struct btrfs_key found_key;
2630
2631 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2632 if (ret < 0)
2633 goto out_free_path;
2634
2635 path->slots[0]--;
2636 leaf = path->nodes[0];
2637 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2638
2639 fi = btrfs_item_ptr(leaf, path->slots[0],
2640 struct btrfs_file_extent_item);
2641 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2642
2643 if (extent_len + found_key.offset == start &&
2644 relink_is_mergable(leaf, fi, new)) {
2645 btrfs_set_file_extent_num_bytes(leaf, fi,
2646 extent_len + len);
2647 btrfs_mark_buffer_dirty(leaf);
2648 inode_add_bytes(inode, len);
2649
2650 ret = 1;
2651 goto out_free_path;
2652 } else {
2653 merge = false;
2654 btrfs_release_path(path);
2655 goto again;
2656 }
2657 }
2658
2659 ret = btrfs_insert_empty_item(trans, root, path, &key,
2660 sizeof(*extent));
2661 if (ret) {
2662 btrfs_abort_transaction(trans, ret);
2663 goto out_free_path;
2664 }
2665
2666 leaf = path->nodes[0];
2667 item = btrfs_item_ptr(leaf, path->slots[0],
2668 struct btrfs_file_extent_item);
2669 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2670 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2671 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2672 btrfs_set_file_extent_num_bytes(leaf, item, len);
2673 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2674 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2675 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2676 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2677 btrfs_set_file_extent_encryption(leaf, item, 0);
2678 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2679
2680 btrfs_mark_buffer_dirty(leaf);
2681 inode_add_bytes(inode, len);
2682 btrfs_release_path(path);
2683
2684 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2685 new->disk_len, 0,
2686 backref->root_id, backref->inum,
2687 new->file_pos); /* start - extent_offset */
2688 if (ret) {
2689 btrfs_abort_transaction(trans, ret);
2690 goto out_free_path;
2691 }
2692
2693 ret = 1;
2694out_free_path:
2695 btrfs_release_path(path);
2696 path->leave_spinning = 0;
2697 btrfs_end_transaction(trans);
2698out_unlock:
2699 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2700 &cached, GFP_NOFS);
2701 iput(inode);
2702 return ret;
2703}
2704
2705static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2706{
2707 struct old_sa_defrag_extent *old, *tmp;
2708
2709 if (!new)
2710 return;
2711
2712 list_for_each_entry_safe(old, tmp, &new->head, list) {
2713 kfree(old);
2714 }
2715 kfree(new);
2716}
2717
2718static void relink_file_extents(struct new_sa_defrag_extent *new)
2719{
2720 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2721 struct btrfs_path *path;
2722 struct sa_defrag_extent_backref *backref;
2723 struct sa_defrag_extent_backref *prev = NULL;
2724 struct inode *inode;
2725 struct btrfs_root *root;
2726 struct rb_node *node;
2727 int ret;
2728
2729 inode = new->inode;
2730 root = BTRFS_I(inode)->root;
2731
2732 path = btrfs_alloc_path();
2733 if (!path)
2734 return;
2735
2736 if (!record_extent_backrefs(path, new)) {
2737 btrfs_free_path(path);
2738 goto out;
2739 }
2740 btrfs_release_path(path);
2741
2742 while (1) {
2743 node = rb_first(&new->root);
2744 if (!node)
2745 break;
2746 rb_erase(node, &new->root);
2747
2748 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2749
2750 ret = relink_extent_backref(path, prev, backref);
2751 WARN_ON(ret < 0);
2752
2753 kfree(prev);
2754
2755 if (ret == 1)
2756 prev = backref;
2757 else
2758 prev = NULL;
2759 cond_resched();
2760 }
2761 kfree(prev);
2762
2763 btrfs_free_path(path);
2764out:
2765 free_sa_defrag_extent(new);
2766
2767 atomic_dec(&fs_info->defrag_running);
2768 wake_up(&fs_info->transaction_wait);
2769}
2770
2771static struct new_sa_defrag_extent *
2772record_old_file_extents(struct inode *inode,
2773 struct btrfs_ordered_extent *ordered)
2774{
2775 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2776 struct btrfs_root *root = BTRFS_I(inode)->root;
2777 struct btrfs_path *path;
2778 struct btrfs_key key;
2779 struct old_sa_defrag_extent *old;
2780 struct new_sa_defrag_extent *new;
2781 int ret;
2782
2783 new = kmalloc(sizeof(*new), GFP_NOFS);
2784 if (!new)
2785 return NULL;
2786
2787 new->inode = inode;
2788 new->file_pos = ordered->file_offset;
2789 new->len = ordered->len;
2790 new->bytenr = ordered->start;
2791 new->disk_len = ordered->disk_len;
2792 new->compress_type = ordered->compress_type;
2793 new->root = RB_ROOT;
2794 INIT_LIST_HEAD(&new->head);
2795
2796 path = btrfs_alloc_path();
2797 if (!path)
2798 goto out_kfree;
2799
2800 key.objectid = btrfs_ino(BTRFS_I(inode));
2801 key.type = BTRFS_EXTENT_DATA_KEY;
2802 key.offset = new->file_pos;
2803
2804 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2805 if (ret < 0)
2806 goto out_free_path;
2807 if (ret > 0 && path->slots[0] > 0)
2808 path->slots[0]--;
2809
2810 /* find out all the old extents for the file range */
2811 while (1) {
2812 struct btrfs_file_extent_item *extent;
2813 struct extent_buffer *l;
2814 int slot;
2815 u64 num_bytes;
2816 u64 offset;
2817 u64 end;
2818 u64 disk_bytenr;
2819 u64 extent_offset;
2820
2821 l = path->nodes[0];
2822 slot = path->slots[0];
2823
2824 if (slot >= btrfs_header_nritems(l)) {
2825 ret = btrfs_next_leaf(root, path);
2826 if (ret < 0)
2827 goto out_free_path;
2828 else if (ret > 0)
2829 break;
2830 continue;
2831 }
2832
2833 btrfs_item_key_to_cpu(l, &key, slot);
2834
2835 if (key.objectid != btrfs_ino(BTRFS_I(inode)))
2836 break;
2837 if (key.type != BTRFS_EXTENT_DATA_KEY)
2838 break;
2839 if (key.offset >= new->file_pos + new->len)
2840 break;
2841
2842 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2843
2844 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2845 if (key.offset + num_bytes < new->file_pos)
2846 goto next;
2847
2848 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2849 if (!disk_bytenr)
2850 goto next;
2851
2852 extent_offset = btrfs_file_extent_offset(l, extent);
2853
2854 old = kmalloc(sizeof(*old), GFP_NOFS);
2855 if (!old)
2856 goto out_free_path;
2857
2858 offset = max(new->file_pos, key.offset);
2859 end = min(new->file_pos + new->len, key.offset + num_bytes);
2860
2861 old->bytenr = disk_bytenr;
2862 old->extent_offset = extent_offset;
2863 old->offset = offset - key.offset;
2864 old->len = end - offset;
2865 old->new = new;
2866 old->count = 0;
2867 list_add_tail(&old->list, &new->head);
2868next:
2869 path->slots[0]++;
2870 cond_resched();
2871 }
2872
2873 btrfs_free_path(path);
2874 atomic_inc(&fs_info->defrag_running);
2875
2876 return new;
2877
2878out_free_path:
2879 btrfs_free_path(path);
2880out_kfree:
2881 free_sa_defrag_extent(new);
2882 return NULL;
2883}
2884
2885static void btrfs_release_delalloc_bytes(struct btrfs_fs_info *fs_info,
2886 u64 start, u64 len)
2887{
2888 struct btrfs_block_group_cache *cache;
2889
2890 cache = btrfs_lookup_block_group(fs_info, start);
2891 ASSERT(cache);
2892
2893 spin_lock(&cache->lock);
2894 cache->delalloc_bytes -= len;
2895 spin_unlock(&cache->lock);
2896
2897 btrfs_put_block_group(cache);
2898}
2899
2900/* as ordered data IO finishes, this gets called so we can finish
2901 * an ordered extent if the range of bytes in the file it covers are
2902 * fully written.
2903 */
2904static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2905{
2906 struct inode *inode = ordered_extent->inode;
2907 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2908 struct btrfs_root *root = BTRFS_I(inode)->root;
2909 struct btrfs_trans_handle *trans = NULL;
2910 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2911 struct extent_state *cached_state = NULL;
2912 struct new_sa_defrag_extent *new = NULL;
2913 int compress_type = 0;
2914 int ret = 0;
2915 u64 logical_len = ordered_extent->len;
2916 bool nolock;
2917 bool truncated = false;
2918 bool range_locked = false;
2919 bool clear_new_delalloc_bytes = false;
2920
2921 if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2922 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags) &&
2923 !test_bit(BTRFS_ORDERED_DIRECT, &ordered_extent->flags))
2924 clear_new_delalloc_bytes = true;
2925
2926 nolock = btrfs_is_free_space_inode(BTRFS_I(inode));
2927
2928 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2929 ret = -EIO;
2930 goto out;
2931 }
2932
2933 btrfs_free_io_failure_record(BTRFS_I(inode),
2934 ordered_extent->file_offset,
2935 ordered_extent->file_offset +
2936 ordered_extent->len - 1);
2937
2938 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2939 truncated = true;
2940 logical_len = ordered_extent->truncated_len;
2941 /* Truncated the entire extent, don't bother adding */
2942 if (!logical_len)
2943 goto out;
2944 }
2945
2946 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2947 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2948
2949 /*
2950 * For mwrite(mmap + memset to write) case, we still reserve
2951 * space for NOCOW range.
2952 * As NOCOW won't cause a new delayed ref, just free the space
2953 */
2954 btrfs_qgroup_free_data(inode, NULL, ordered_extent->file_offset,
2955 ordered_extent->len);
2956 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2957 if (nolock)
2958 trans = btrfs_join_transaction_nolock(root);
2959 else
2960 trans = btrfs_join_transaction(root);
2961 if (IS_ERR(trans)) {
2962 ret = PTR_ERR(trans);
2963 trans = NULL;
2964 goto out;
2965 }
2966 trans->block_rsv = &BTRFS_I(inode)->block_rsv;
2967 ret = btrfs_update_inode_fallback(trans, root, inode);
2968 if (ret) /* -ENOMEM or corruption */
2969 btrfs_abort_transaction(trans, ret);
2970 goto out;
2971 }
2972
2973 range_locked = true;
2974 lock_extent_bits(io_tree, ordered_extent->file_offset,
2975 ordered_extent->file_offset + ordered_extent->len - 1,
2976 &cached_state);
2977
2978 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2979 ordered_extent->file_offset + ordered_extent->len - 1,
2980 EXTENT_DEFRAG, 0, cached_state);
2981 if (ret) {
2982 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2983 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
2984 /* the inode is shared */
2985 new = record_old_file_extents(inode, ordered_extent);
2986
2987 clear_extent_bit(io_tree, ordered_extent->file_offset,
2988 ordered_extent->file_offset + ordered_extent->len - 1,
2989 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2990 }
2991
2992 if (nolock)
2993 trans = btrfs_join_transaction_nolock(root);
2994 else
2995 trans = btrfs_join_transaction(root);
2996 if (IS_ERR(trans)) {
2997 ret = PTR_ERR(trans);
2998 trans = NULL;
2999 goto out;
3000 }
3001
3002 trans->block_rsv = &BTRFS_I(inode)->block_rsv;
3003
3004 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
3005 compress_type = ordered_extent->compress_type;
3006 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
3007 BUG_ON(compress_type);
3008 btrfs_qgroup_free_data(inode, NULL, ordered_extent->file_offset,
3009 ordered_extent->len);
3010 ret = btrfs_mark_extent_written(trans, BTRFS_I(inode),
3011 ordered_extent->file_offset,
3012 ordered_extent->file_offset +
3013 logical_len);
3014 } else {
3015 BUG_ON(root == fs_info->tree_root);
3016 ret = insert_reserved_file_extent(trans, inode,
3017 ordered_extent->file_offset,
3018 ordered_extent->start,
3019 ordered_extent->disk_len,
3020 logical_len, logical_len,
3021 compress_type, 0, 0,
3022 BTRFS_FILE_EXTENT_REG);
3023 if (!ret)
3024 btrfs_release_delalloc_bytes(fs_info,
3025 ordered_extent->start,
3026 ordered_extent->disk_len);
3027 }
3028 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
3029 ordered_extent->file_offset, ordered_extent->len,
3030 trans->transid);
3031 if (ret < 0) {
3032 btrfs_abort_transaction(trans, ret);
3033 goto out;
3034 }
3035
3036 add_pending_csums(trans, inode, &ordered_extent->list);
3037
3038 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
3039 ret = btrfs_update_inode_fallback(trans, root, inode);
3040 if (ret) { /* -ENOMEM or corruption */
3041 btrfs_abort_transaction(trans, ret);
3042 goto out;
3043 }
3044 ret = 0;
3045out:
3046 if (range_locked || clear_new_delalloc_bytes) {
3047 unsigned int clear_bits = 0;
3048
3049 if (range_locked)
3050 clear_bits |= EXTENT_LOCKED;
3051 if (clear_new_delalloc_bytes)
3052 clear_bits |= EXTENT_DELALLOC_NEW;
3053 clear_extent_bit(&BTRFS_I(inode)->io_tree,
3054 ordered_extent->file_offset,
3055 ordered_extent->file_offset +
3056 ordered_extent->len - 1,
3057 clear_bits,
3058 (clear_bits & EXTENT_LOCKED) ? 1 : 0,
3059 0, &cached_state, GFP_NOFS);
3060 }
3061
3062 if (trans)
3063 btrfs_end_transaction(trans);
3064
3065 if (ret || truncated) {
3066 u64 start, end;
3067
3068 if (truncated)
3069 start = ordered_extent->file_offset + logical_len;
3070 else
3071 start = ordered_extent->file_offset;
3072 end = ordered_extent->file_offset + ordered_extent->len - 1;
3073 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
3074
3075 /* Drop the cache for the part of the extent we didn't write. */
3076 btrfs_drop_extent_cache(BTRFS_I(inode), start, end, 0);
3077
3078 /*
3079 * If the ordered extent had an IOERR or something else went
3080 * wrong we need to return the space for this ordered extent
3081 * back to the allocator. We only free the extent in the
3082 * truncated case if we didn't write out the extent at all.
3083 */
3084 if ((ret || !logical_len) &&
3085 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
3086 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
3087 btrfs_free_reserved_extent(fs_info,
3088 ordered_extent->start,
3089 ordered_extent->disk_len, 1);
3090 }
3091
3092
3093 /*
3094 * This needs to be done to make sure anybody waiting knows we are done
3095 * updating everything for this ordered extent.
3096 */
3097 btrfs_remove_ordered_extent(inode, ordered_extent);
3098
3099 /* for snapshot-aware defrag */
3100 if (new) {
3101 if (ret) {
3102 free_sa_defrag_extent(new);
3103 atomic_dec(&fs_info->defrag_running);
3104 } else {
3105 relink_file_extents(new);
3106 }
3107 }
3108
3109 /* once for us */
3110 btrfs_put_ordered_extent(ordered_extent);
3111 /* once for the tree */
3112 btrfs_put_ordered_extent(ordered_extent);
3113
3114 return ret;
3115}
3116
3117static void finish_ordered_fn(struct btrfs_work *work)
3118{
3119 struct btrfs_ordered_extent *ordered_extent;
3120 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
3121 btrfs_finish_ordered_io(ordered_extent);
3122}
3123
3124static void btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
3125 struct extent_state *state, int uptodate)
3126{
3127 struct inode *inode = page->mapping->host;
3128 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3129 struct btrfs_ordered_extent *ordered_extent = NULL;
3130 struct btrfs_workqueue *wq;
3131 btrfs_work_func_t func;
3132
3133 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
3134
3135 ClearPagePrivate2(page);
3136 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
3137 end - start + 1, uptodate))
3138 return;
3139
3140 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
3141 wq = fs_info->endio_freespace_worker;
3142 func = btrfs_freespace_write_helper;
3143 } else {
3144 wq = fs_info->endio_write_workers;
3145 func = btrfs_endio_write_helper;
3146 }
3147
3148 btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
3149 NULL);
3150 btrfs_queue_work(wq, &ordered_extent->work);
3151}
3152
3153static int __readpage_endio_check(struct inode *inode,
3154 struct btrfs_io_bio *io_bio,
3155 int icsum, struct page *page,
3156 int pgoff, u64 start, size_t len)
3157{
3158 char *kaddr;
3159 u32 csum_expected;
3160 u32 csum = ~(u32)0;
3161
3162 csum_expected = *(((u32 *)io_bio->csum) + icsum);
3163
3164 kaddr = kmap_atomic(page);
3165 csum = btrfs_csum_data(kaddr + pgoff, csum, len);
3166 btrfs_csum_final(csum, (u8 *)&csum);
3167 if (csum != csum_expected)
3168 goto zeroit;
3169
3170 kunmap_atomic(kaddr);
3171 return 0;
3172zeroit:
3173 btrfs_print_data_csum_error(BTRFS_I(inode), start, csum, csum_expected,
3174 io_bio->mirror_num);
3175 memset(kaddr + pgoff, 1, len);
3176 flush_dcache_page(page);
3177 kunmap_atomic(kaddr);
3178 return -EIO;
3179}
3180
3181/*
3182 * when reads are done, we need to check csums to verify the data is correct
3183 * if there's a match, we allow the bio to finish. If not, the code in
3184 * extent_io.c will try to find good copies for us.
3185 */
3186static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
3187 u64 phy_offset, struct page *page,
3188 u64 start, u64 end, int mirror)
3189{
3190 size_t offset = start - page_offset(page);
3191 struct inode *inode = page->mapping->host;
3192 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3193 struct btrfs_root *root = BTRFS_I(inode)->root;
3194
3195 if (PageChecked(page)) {
3196 ClearPageChecked(page);
3197 return 0;
3198 }
3199
3200 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3201 return 0;
3202
3203 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
3204 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
3205 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM);
3206 return 0;
3207 }
3208
3209 phy_offset >>= inode->i_sb->s_blocksize_bits;
3210 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3211 start, (size_t)(end - start + 1));
3212}
3213
3214void btrfs_add_delayed_iput(struct inode *inode)
3215{
3216 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3217 struct btrfs_inode *binode = BTRFS_I(inode);
3218
3219 if (atomic_add_unless(&inode->i_count, -1, 1))
3220 return;
3221
3222 spin_lock(&fs_info->delayed_iput_lock);
3223 if (binode->delayed_iput_count == 0) {
3224 ASSERT(list_empty(&binode->delayed_iput));
3225 list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
3226 } else {
3227 binode->delayed_iput_count++;
3228 }
3229 spin_unlock(&fs_info->delayed_iput_lock);
3230}
3231
3232void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info)
3233{
3234
3235 spin_lock(&fs_info->delayed_iput_lock);
3236 while (!list_empty(&fs_info->delayed_iputs)) {
3237 struct btrfs_inode *inode;
3238
3239 inode = list_first_entry(&fs_info->delayed_iputs,
3240 struct btrfs_inode, delayed_iput);
3241 if (inode->delayed_iput_count) {
3242 inode->delayed_iput_count--;
3243 list_move_tail(&inode->delayed_iput,
3244 &fs_info->delayed_iputs);
3245 } else {
3246 list_del_init(&inode->delayed_iput);
3247 }
3248 spin_unlock(&fs_info->delayed_iput_lock);
3249 iput(&inode->vfs_inode);
3250 spin_lock(&fs_info->delayed_iput_lock);
3251 }
3252 spin_unlock(&fs_info->delayed_iput_lock);
3253}
3254
3255/*
3256 * This is called in transaction commit time. If there are no orphan
3257 * files in the subvolume, it removes orphan item and frees block_rsv
3258 * structure.
3259 */
3260void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
3261 struct btrfs_root *root)
3262{
3263 struct btrfs_fs_info *fs_info = root->fs_info;
3264 struct btrfs_block_rsv *block_rsv;
3265 int ret;
3266
3267 if (atomic_read(&root->orphan_inodes) ||
3268 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
3269 return;
3270
3271 spin_lock(&root->orphan_lock);
3272 if (atomic_read(&root->orphan_inodes)) {
3273 spin_unlock(&root->orphan_lock);
3274 return;
3275 }
3276
3277 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
3278 spin_unlock(&root->orphan_lock);
3279 return;
3280 }
3281
3282 block_rsv = root->orphan_block_rsv;
3283 root->orphan_block_rsv = NULL;
3284 spin_unlock(&root->orphan_lock);
3285
3286 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
3287 btrfs_root_refs(&root->root_item) > 0) {
3288 ret = btrfs_del_orphan_item(trans, fs_info->tree_root,
3289 root->root_key.objectid);
3290 if (ret)
3291 btrfs_abort_transaction(trans, ret);
3292 else
3293 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
3294 &root->state);
3295 }
3296
3297 if (block_rsv) {
3298 WARN_ON(block_rsv->size > 0);
3299 btrfs_free_block_rsv(fs_info, block_rsv);
3300 }
3301}
3302
3303/*
3304 * This creates an orphan entry for the given inode in case something goes
3305 * wrong in the middle of an unlink/truncate.
3306 *
3307 * NOTE: caller of this function should reserve 5 units of metadata for
3308 * this function.
3309 */
3310int btrfs_orphan_add(struct btrfs_trans_handle *trans,
3311 struct btrfs_inode *inode)
3312{
3313 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
3314 struct btrfs_root *root = inode->root;
3315 struct btrfs_block_rsv *block_rsv = NULL;
3316 int reserve = 0;
3317 int insert = 0;
3318 int ret;
3319
3320 if (!root->orphan_block_rsv) {
3321 block_rsv = btrfs_alloc_block_rsv(fs_info,
3322 BTRFS_BLOCK_RSV_TEMP);
3323 if (!block_rsv)
3324 return -ENOMEM;
3325 }
3326
3327 spin_lock(&root->orphan_lock);
3328 if (!root->orphan_block_rsv) {
3329 root->orphan_block_rsv = block_rsv;
3330 } else if (block_rsv) {
3331 btrfs_free_block_rsv(fs_info, block_rsv);
3332 block_rsv = NULL;
3333 }
3334
3335 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3336 &inode->runtime_flags)) {
3337#if 0
3338 /*
3339 * For proper ENOSPC handling, we should do orphan
3340 * cleanup when mounting. But this introduces backward
3341 * compatibility issue.
3342 */
3343 if (!xchg(&root->orphan_item_inserted, 1))
3344 insert = 2;
3345 else
3346 insert = 1;
3347#endif
3348 insert = 1;
3349 atomic_inc(&root->orphan_inodes);
3350 }
3351
3352 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3353 &inode->runtime_flags))
3354 reserve = 1;
3355 spin_unlock(&root->orphan_lock);
3356
3357 /* grab metadata reservation from transaction handle */
3358 if (reserve) {
3359 ret = btrfs_orphan_reserve_metadata(trans, inode);
3360 ASSERT(!ret);
3361 if (ret) {
3362 atomic_dec(&root->orphan_inodes);
3363 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3364 &inode->runtime_flags);
3365 if (insert)
3366 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3367 &inode->runtime_flags);
3368 return ret;
3369 }
3370 }
3371
3372 /* insert an orphan item to track this unlinked/truncated file */
3373 if (insert >= 1) {
3374 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3375 if (ret) {
3376 atomic_dec(&root->orphan_inodes);
3377 if (reserve) {
3378 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3379 &inode->runtime_flags);
3380 btrfs_orphan_release_metadata(inode);
3381 }
3382 if (ret != -EEXIST) {
3383 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3384 &inode->runtime_flags);
3385 btrfs_abort_transaction(trans, ret);
3386 return ret;
3387 }
3388 }
3389 ret = 0;
3390 }
3391
3392 /* insert an orphan item to track subvolume contains orphan files */
3393 if (insert >= 2) {
3394 ret = btrfs_insert_orphan_item(trans, fs_info->tree_root,
3395 root->root_key.objectid);
3396 if (ret && ret != -EEXIST) {
3397 btrfs_abort_transaction(trans, ret);
3398 return ret;
3399 }
3400 }
3401 return 0;
3402}
3403
3404/*
3405 * We have done the truncate/delete so we can go ahead and remove the orphan
3406 * item for this particular inode.
3407 */
3408static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3409 struct btrfs_inode *inode)
3410{
3411 struct btrfs_root *root = inode->root;
3412 int delete_item = 0;
3413 int release_rsv = 0;
3414 int ret = 0;
3415
3416 spin_lock(&root->orphan_lock);
3417 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3418 &inode->runtime_flags))
3419 delete_item = 1;
3420
3421 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3422 &inode->runtime_flags))
3423 release_rsv = 1;
3424 spin_unlock(&root->orphan_lock);
3425
3426 if (delete_item) {
3427 atomic_dec(&root->orphan_inodes);
3428 if (trans)
3429 ret = btrfs_del_orphan_item(trans, root,
3430 btrfs_ino(inode));
3431 }
3432
3433 if (release_rsv)
3434 btrfs_orphan_release_metadata(inode);
3435
3436 return ret;
3437}
3438
3439/*
3440 * this cleans up any orphans that may be left on the list from the last use
3441 * of this root.
3442 */
3443int btrfs_orphan_cleanup(struct btrfs_root *root)
3444{
3445 struct btrfs_fs_info *fs_info = root->fs_info;
3446 struct btrfs_path *path;
3447 struct extent_buffer *leaf;
3448 struct btrfs_key key, found_key;
3449 struct btrfs_trans_handle *trans;
3450 struct inode *inode;
3451 u64 last_objectid = 0;
3452 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3453
3454 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3455 return 0;
3456
3457 path = btrfs_alloc_path();
3458 if (!path) {
3459 ret = -ENOMEM;
3460 goto out;
3461 }
3462 path->reada = READA_BACK;
3463
3464 key.objectid = BTRFS_ORPHAN_OBJECTID;
3465 key.type = BTRFS_ORPHAN_ITEM_KEY;
3466 key.offset = (u64)-1;
3467
3468 while (1) {
3469 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3470 if (ret < 0)
3471 goto out;
3472
3473 /*
3474 * if ret == 0 means we found what we were searching for, which
3475 * is weird, but possible, so only screw with path if we didn't
3476 * find the key and see if we have stuff that matches
3477 */
3478 if (ret > 0) {
3479 ret = 0;
3480 if (path->slots[0] == 0)
3481 break;
3482 path->slots[0]--;
3483 }
3484
3485 /* pull out the item */
3486 leaf = path->nodes[0];
3487 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3488
3489 /* make sure the item matches what we want */
3490 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3491 break;
3492 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3493 break;
3494
3495 /* release the path since we're done with it */
3496 btrfs_release_path(path);
3497
3498 /*
3499 * this is where we are basically btrfs_lookup, without the
3500 * crossing root thing. we store the inode number in the
3501 * offset of the orphan item.
3502 */
3503
3504 if (found_key.offset == last_objectid) {
3505 btrfs_err(fs_info,
3506 "Error removing orphan entry, stopping orphan cleanup");
3507 ret = -EINVAL;
3508 goto out;
3509 }
3510
3511 last_objectid = found_key.offset;
3512
3513 found_key.objectid = found_key.offset;
3514 found_key.type = BTRFS_INODE_ITEM_KEY;
3515 found_key.offset = 0;
3516 inode = btrfs_iget(fs_info->sb, &found_key, root, NULL);
3517 ret = PTR_ERR_OR_ZERO(inode);
3518 if (ret && ret != -ENOENT)
3519 goto out;
3520
3521 if (ret == -ENOENT && root == fs_info->tree_root) {
3522 struct btrfs_root *dead_root;
3523 struct btrfs_fs_info *fs_info = root->fs_info;
3524 int is_dead_root = 0;
3525
3526 /*
3527 * this is an orphan in the tree root. Currently these
3528 * could come from 2 sources:
3529 * a) a snapshot deletion in progress
3530 * b) a free space cache inode
3531 * We need to distinguish those two, as the snapshot
3532 * orphan must not get deleted.
3533 * find_dead_roots already ran before us, so if this
3534 * is a snapshot deletion, we should find the root
3535 * in the dead_roots list
3536 */
3537 spin_lock(&fs_info->trans_lock);
3538 list_for_each_entry(dead_root, &fs_info->dead_roots,
3539 root_list) {
3540 if (dead_root->root_key.objectid ==
3541 found_key.objectid) {
3542 is_dead_root = 1;
3543 break;
3544 }
3545 }
3546 spin_unlock(&fs_info->trans_lock);
3547 if (is_dead_root) {
3548 /* prevent this orphan from being found again */
3549 key.offset = found_key.objectid - 1;
3550 continue;
3551 }
3552 }
3553 /*
3554 * Inode is already gone but the orphan item is still there,
3555 * kill the orphan item.
3556 */
3557 if (ret == -ENOENT) {
3558 trans = btrfs_start_transaction(root, 1);
3559 if (IS_ERR(trans)) {
3560 ret = PTR_ERR(trans);
3561 goto out;
3562 }
3563 btrfs_debug(fs_info, "auto deleting %Lu",
3564 found_key.objectid);
3565 ret = btrfs_del_orphan_item(trans, root,
3566 found_key.objectid);
3567 btrfs_end_transaction(trans);
3568 if (ret)
3569 goto out;
3570 continue;
3571 }
3572
3573 /*
3574 * add this inode to the orphan list so btrfs_orphan_del does
3575 * the proper thing when we hit it
3576 */
3577 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3578 &BTRFS_I(inode)->runtime_flags);
3579 atomic_inc(&root->orphan_inodes);
3580
3581 /* if we have links, this was a truncate, lets do that */
3582 if (inode->i_nlink) {
3583 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3584 iput(inode);
3585 continue;
3586 }
3587 nr_truncate++;
3588
3589 /* 1 for the orphan item deletion. */
3590 trans = btrfs_start_transaction(root, 1);
3591 if (IS_ERR(trans)) {
3592 iput(inode);
3593 ret = PTR_ERR(trans);
3594 goto out;
3595 }
3596 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
3597 btrfs_end_transaction(trans);
3598 if (ret) {
3599 iput(inode);
3600 goto out;
3601 }
3602
3603 ret = btrfs_truncate(inode);
3604 if (ret)
3605 btrfs_orphan_del(NULL, BTRFS_I(inode));
3606 } else {
3607 nr_unlink++;
3608 }
3609
3610 /* this will do delete_inode and everything for us */
3611 iput(inode);
3612 if (ret)
3613 goto out;
3614 }
3615 /* release the path since we're done with it */
3616 btrfs_release_path(path);
3617
3618 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3619
3620 if (root->orphan_block_rsv)
3621 btrfs_block_rsv_release(fs_info, root->orphan_block_rsv,
3622 (u64)-1);
3623
3624 if (root->orphan_block_rsv ||
3625 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3626 trans = btrfs_join_transaction(root);
3627 if (!IS_ERR(trans))
3628 btrfs_end_transaction(trans);
3629 }
3630
3631 if (nr_unlink)
3632 btrfs_debug(fs_info, "unlinked %d orphans", nr_unlink);
3633 if (nr_truncate)
3634 btrfs_debug(fs_info, "truncated %d orphans", nr_truncate);
3635
3636out:
3637 if (ret)
3638 btrfs_err(fs_info, "could not do orphan cleanup %d", ret);
3639 btrfs_free_path(path);
3640 return ret;
3641}
3642
3643/*
3644 * very simple check to peek ahead in the leaf looking for xattrs. If we
3645 * don't find any xattrs, we know there can't be any acls.
3646 *
3647 * slot is the slot the inode is in, objectid is the objectid of the inode
3648 */
3649static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3650 int slot, u64 objectid,
3651 int *first_xattr_slot)
3652{
3653 u32 nritems = btrfs_header_nritems(leaf);
3654 struct btrfs_key found_key;
3655 static u64 xattr_access = 0;
3656 static u64 xattr_default = 0;
3657 int scanned = 0;
3658
3659 if (!xattr_access) {
3660 xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
3661 strlen(XATTR_NAME_POSIX_ACL_ACCESS));
3662 xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
3663 strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
3664 }
3665
3666 slot++;
3667 *first_xattr_slot = -1;
3668 while (slot < nritems) {
3669 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3670
3671 /* we found a different objectid, there must not be acls */
3672 if (found_key.objectid != objectid)
3673 return 0;
3674
3675 /* we found an xattr, assume we've got an acl */
3676 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3677 if (*first_xattr_slot == -1)
3678 *first_xattr_slot = slot;
3679 if (found_key.offset == xattr_access ||
3680 found_key.offset == xattr_default)
3681 return 1;
3682 }
3683
3684 /*
3685 * we found a key greater than an xattr key, there can't
3686 * be any acls later on
3687 */
3688 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3689 return 0;
3690
3691 slot++;
3692 scanned++;
3693
3694 /*
3695 * it goes inode, inode backrefs, xattrs, extents,
3696 * so if there are a ton of hard links to an inode there can
3697 * be a lot of backrefs. Don't waste time searching too hard,
3698 * this is just an optimization
3699 */
3700 if (scanned >= 8)
3701 break;
3702 }
3703 /* we hit the end of the leaf before we found an xattr or
3704 * something larger than an xattr. We have to assume the inode
3705 * has acls
3706 */
3707 if (*first_xattr_slot == -1)
3708 *first_xattr_slot = slot;
3709 return 1;
3710}
3711
3712/*
3713 * read an inode from the btree into the in-memory inode
3714 */
3715static int btrfs_read_locked_inode(struct inode *inode)
3716{
3717 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3718 struct btrfs_path *path;
3719 struct extent_buffer *leaf;
3720 struct btrfs_inode_item *inode_item;
3721 struct btrfs_root *root = BTRFS_I(inode)->root;
3722 struct btrfs_key location;
3723 unsigned long ptr;
3724 int maybe_acls;
3725 u32 rdev;
3726 int ret;
3727 bool filled = false;
3728 int first_xattr_slot;
3729
3730 ret = btrfs_fill_inode(inode, &rdev);
3731 if (!ret)
3732 filled = true;
3733
3734 path = btrfs_alloc_path();
3735 if (!path) {
3736 ret = -ENOMEM;
3737 goto make_bad;
3738 }
3739
3740 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3741
3742 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3743 if (ret) {
3744 if (ret > 0)
3745 ret = -ENOENT;
3746 goto make_bad;
3747 }
3748
3749 leaf = path->nodes[0];
3750
3751 if (filled)
3752 goto cache_index;
3753
3754 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3755 struct btrfs_inode_item);
3756 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3757 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3758 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3759 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3760 btrfs_i_size_write(BTRFS_I(inode), btrfs_inode_size(leaf, inode_item));
3761
3762 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3763 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3764
3765 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3766 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3767
3768 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3769 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3770
3771 BTRFS_I(inode)->i_otime.tv_sec =
3772 btrfs_timespec_sec(leaf, &inode_item->otime);
3773 BTRFS_I(inode)->i_otime.tv_nsec =
3774 btrfs_timespec_nsec(leaf, &inode_item->otime);
3775
3776 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3777 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3778 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3779
3780 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3781 inode->i_generation = BTRFS_I(inode)->generation;
3782 inode->i_rdev = 0;
3783 rdev = btrfs_inode_rdev(leaf, inode_item);
3784
3785 BTRFS_I(inode)->index_cnt = (u64)-1;
3786 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3787
3788cache_index:
3789 /*
3790 * If we were modified in the current generation and evicted from memory
3791 * and then re-read we need to do a full sync since we don't have any
3792 * idea about which extents were modified before we were evicted from
3793 * cache.
3794 *
3795 * This is required for both inode re-read from disk and delayed inode
3796 * in delayed_nodes_tree.
3797 */
3798 if (BTRFS_I(inode)->last_trans == fs_info->generation)
3799 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3800 &BTRFS_I(inode)->runtime_flags);
3801
3802 /*
3803 * We don't persist the id of the transaction where an unlink operation
3804 * against the inode was last made. So here we assume the inode might
3805 * have been evicted, and therefore the exact value of last_unlink_trans
3806 * lost, and set it to last_trans to avoid metadata inconsistencies
3807 * between the inode and its parent if the inode is fsync'ed and the log
3808 * replayed. For example, in the scenario:
3809 *
3810 * touch mydir/foo
3811 * ln mydir/foo mydir/bar
3812 * sync
3813 * unlink mydir/bar
3814 * echo 2 > /proc/sys/vm/drop_caches # evicts inode
3815 * xfs_io -c fsync mydir/foo
3816 * <power failure>
3817 * mount fs, triggers fsync log replay
3818 *
3819 * We must make sure that when we fsync our inode foo we also log its
3820 * parent inode, otherwise after log replay the parent still has the
3821 * dentry with the "bar" name but our inode foo has a link count of 1
3822 * and doesn't have an inode ref with the name "bar" anymore.
3823 *
3824 * Setting last_unlink_trans to last_trans is a pessimistic approach,
3825 * but it guarantees correctness at the expense of occasional full
3826 * transaction commits on fsync if our inode is a directory, or if our
3827 * inode is not a directory, logging its parent unnecessarily.
3828 */
3829 BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
3830
3831 path->slots[0]++;
3832 if (inode->i_nlink != 1 ||
3833 path->slots[0] >= btrfs_header_nritems(leaf))
3834 goto cache_acl;
3835
3836 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3837 if (location.objectid != btrfs_ino(BTRFS_I(inode)))
3838 goto cache_acl;
3839
3840 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3841 if (location.type == BTRFS_INODE_REF_KEY) {
3842 struct btrfs_inode_ref *ref;
3843
3844 ref = (struct btrfs_inode_ref *)ptr;
3845 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3846 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3847 struct btrfs_inode_extref *extref;
3848
3849 extref = (struct btrfs_inode_extref *)ptr;
3850 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3851 extref);
3852 }
3853cache_acl:
3854 /*
3855 * try to precache a NULL acl entry for files that don't have
3856 * any xattrs or acls
3857 */
3858 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3859 btrfs_ino(BTRFS_I(inode)), &first_xattr_slot);
3860 if (first_xattr_slot != -1) {
3861 path->slots[0] = first_xattr_slot;
3862 ret = btrfs_load_inode_props(inode, path);
3863 if (ret)
3864 btrfs_err(fs_info,
3865 "error loading props for ino %llu (root %llu): %d",
3866 btrfs_ino(BTRFS_I(inode)),
3867 root->root_key.objectid, ret);
3868 }
3869 btrfs_free_path(path);
3870
3871 if (!maybe_acls)
3872 cache_no_acl(inode);
3873
3874 switch (inode->i_mode & S_IFMT) {
3875 case S_IFREG:
3876 inode->i_mapping->a_ops = &btrfs_aops;
3877 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3878 inode->i_fop = &btrfs_file_operations;
3879 inode->i_op = &btrfs_file_inode_operations;
3880 break;
3881 case S_IFDIR:
3882 inode->i_fop = &btrfs_dir_file_operations;
3883 inode->i_op = &btrfs_dir_inode_operations;
3884 break;
3885 case S_IFLNK:
3886 inode->i_op = &btrfs_symlink_inode_operations;
3887 inode_nohighmem(inode);
3888 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3889 break;
3890 default:
3891 inode->i_op = &btrfs_special_inode_operations;
3892 init_special_inode(inode, inode->i_mode, rdev);
3893 break;
3894 }
3895
3896 btrfs_update_iflags(inode);
3897 return 0;
3898
3899make_bad:
3900 btrfs_free_path(path);
3901 make_bad_inode(inode);
3902 return ret;
3903}
3904
3905/*
3906 * given a leaf and an inode, copy the inode fields into the leaf
3907 */
3908static void fill_inode_item(struct btrfs_trans_handle *trans,
3909 struct extent_buffer *leaf,
3910 struct btrfs_inode_item *item,
3911 struct inode *inode)
3912{
3913 struct btrfs_map_token token;
3914
3915 btrfs_init_map_token(&token);
3916
3917 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3918 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3919 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3920 &token);
3921 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3922 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3923
3924 btrfs_set_token_timespec_sec(leaf, &item->atime,
3925 inode->i_atime.tv_sec, &token);
3926 btrfs_set_token_timespec_nsec(leaf, &item->atime,
3927 inode->i_atime.tv_nsec, &token);
3928
3929 btrfs_set_token_timespec_sec(leaf, &item->mtime,
3930 inode->i_mtime.tv_sec, &token);
3931 btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3932 inode->i_mtime.tv_nsec, &token);
3933
3934 btrfs_set_token_timespec_sec(leaf, &item->ctime,
3935 inode->i_ctime.tv_sec, &token);
3936 btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3937 inode->i_ctime.tv_nsec, &token);
3938
3939 btrfs_set_token_timespec_sec(leaf, &item->otime,
3940 BTRFS_I(inode)->i_otime.tv_sec, &token);
3941 btrfs_set_token_timespec_nsec(leaf, &item->otime,
3942 BTRFS_I(inode)->i_otime.tv_nsec, &token);
3943
3944 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3945 &token);
3946 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3947 &token);
3948 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3949 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3950 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3951 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3952 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3953}
3954
3955/*
3956 * copy everything in the in-memory inode into the btree.
3957 */
3958static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3959 struct btrfs_root *root, struct inode *inode)
3960{
3961 struct btrfs_inode_item *inode_item;
3962 struct btrfs_path *path;
3963 struct extent_buffer *leaf;
3964 int ret;
3965
3966 path = btrfs_alloc_path();
3967 if (!path)
3968 return -ENOMEM;
3969
3970 path->leave_spinning = 1;
3971 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3972 1);
3973 if (ret) {
3974 if (ret > 0)
3975 ret = -ENOENT;
3976 goto failed;
3977 }
3978
3979 leaf = path->nodes[0];
3980 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3981 struct btrfs_inode_item);
3982
3983 fill_inode_item(trans, leaf, inode_item, inode);
3984 btrfs_mark_buffer_dirty(leaf);
3985 btrfs_set_inode_last_trans(trans, inode);
3986 ret = 0;
3987failed:
3988 btrfs_free_path(path);
3989 return ret;
3990}
3991
3992/*
3993 * copy everything in the in-memory inode into the btree.
3994 */
3995noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3996 struct btrfs_root *root, struct inode *inode)
3997{
3998 struct btrfs_fs_info *fs_info = root->fs_info;
3999 int ret;
4000
4001 /*
4002 * If the inode is a free space inode, we can deadlock during commit
4003 * if we put it into the delayed code.
4004 *
4005 * The data relocation inode should also be directly updated
4006 * without delay
4007 */
4008 if (!btrfs_is_free_space_inode(BTRFS_I(inode))
4009 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
4010 && !test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
4011 btrfs_update_root_times(trans, root);
4012
4013 ret = btrfs_delayed_update_inode(trans, root, inode);
4014 if (!ret)
4015 btrfs_set_inode_last_trans(trans, inode);
4016 return ret;
4017 }
4018
4019 return btrfs_update_inode_item(trans, root, inode);
4020}
4021
4022noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
4023 struct btrfs_root *root,
4024 struct inode *inode)
4025{
4026 int ret;
4027
4028 ret = btrfs_update_inode(trans, root, inode);
4029 if (ret == -ENOSPC)
4030 return btrfs_update_inode_item(trans, root, inode);
4031 return ret;
4032}
4033
4034/*
4035 * unlink helper that gets used here in inode.c and in the tree logging
4036 * recovery code. It remove a link in a directory with a given name, and
4037 * also drops the back refs in the inode to the directory
4038 */
4039static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4040 struct btrfs_root *root,
4041 struct btrfs_inode *dir,
4042 struct btrfs_inode *inode,
4043 const char *name, int name_len)
4044{
4045 struct btrfs_fs_info *fs_info = root->fs_info;
4046 struct btrfs_path *path;
4047 int ret = 0;
4048 struct extent_buffer *leaf;
4049 struct btrfs_dir_item *di;
4050 struct btrfs_key key;
4051 u64 index;
4052 u64 ino = btrfs_ino(inode);
4053 u64 dir_ino = btrfs_ino(dir);
4054
4055 path = btrfs_alloc_path();
4056 if (!path) {
4057 ret = -ENOMEM;
4058 goto out;
4059 }
4060
4061 path->leave_spinning = 1;
4062 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4063 name, name_len, -1);
4064 if (IS_ERR(di)) {
4065 ret = PTR_ERR(di);
4066 goto err;
4067 }
4068 if (!di) {
4069 ret = -ENOENT;
4070 goto err;
4071 }
4072 leaf = path->nodes[0];
4073 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4074 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4075 if (ret)
4076 goto err;
4077 btrfs_release_path(path);
4078
4079 /*
4080 * If we don't have dir index, we have to get it by looking up
4081 * the inode ref, since we get the inode ref, remove it directly,
4082 * it is unnecessary to do delayed deletion.
4083 *
4084 * But if we have dir index, needn't search inode ref to get it.
4085 * Since the inode ref is close to the inode item, it is better
4086 * that we delay to delete it, and just do this deletion when
4087 * we update the inode item.
4088 */
4089 if (inode->dir_index) {
4090 ret = btrfs_delayed_delete_inode_ref(inode);
4091 if (!ret) {
4092 index = inode->dir_index;
4093 goto skip_backref;
4094 }
4095 }
4096
4097 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
4098 dir_ino, &index);
4099 if (ret) {
4100 btrfs_info(fs_info,
4101 "failed to delete reference to %.*s, inode %llu parent %llu",
4102 name_len, name, ino, dir_ino);
4103 btrfs_abort_transaction(trans, ret);
4104 goto err;
4105 }
4106skip_backref:
4107 ret = btrfs_delete_delayed_dir_index(trans, fs_info, dir, index);
4108 if (ret) {
4109 btrfs_abort_transaction(trans, ret);
4110 goto err;
4111 }
4112
4113 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, inode,
4114 dir_ino);
4115 if (ret != 0 && ret != -ENOENT) {
4116 btrfs_abort_transaction(trans, ret);
4117 goto err;
4118 }
4119
4120 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, dir,
4121 index);
4122 if (ret == -ENOENT)
4123 ret = 0;
4124 else if (ret)
4125 btrfs_abort_transaction(trans, ret);
4126err:
4127 btrfs_free_path(path);
4128 if (ret)
4129 goto out;
4130
4131 btrfs_i_size_write(dir, dir->vfs_inode.i_size - name_len * 2);
4132 inode_inc_iversion(&inode->vfs_inode);
4133 inode_inc_iversion(&dir->vfs_inode);
4134 inode->vfs_inode.i_ctime = dir->vfs_inode.i_mtime =
4135 dir->vfs_inode.i_ctime = current_time(&inode->vfs_inode);
4136 ret = btrfs_update_inode(trans, root, &dir->vfs_inode);
4137out:
4138 return ret;
4139}
4140
4141int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4142 struct btrfs_root *root,
4143 struct btrfs_inode *dir, struct btrfs_inode *inode,
4144 const char *name, int name_len)
4145{
4146 int ret;
4147 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
4148 if (!ret) {
4149 drop_nlink(&inode->vfs_inode);
4150 ret = btrfs_update_inode(trans, root, &inode->vfs_inode);
4151 }
4152 return ret;
4153}
4154
4155/*
4156 * helper to start transaction for unlink and rmdir.
4157 *
4158 * unlink and rmdir are special in btrfs, they do not always free space, so
4159 * if we cannot make our reservations the normal way try and see if there is
4160 * plenty of slack room in the global reserve to migrate, otherwise we cannot
4161 * allow the unlink to occur.
4162 */
4163static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
4164{
4165 struct btrfs_root *root = BTRFS_I(dir)->root;
4166
4167 /*
4168 * 1 for the possible orphan item
4169 * 1 for the dir item
4170 * 1 for the dir index
4171 * 1 for the inode ref
4172 * 1 for the inode
4173 */
4174 return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
4175}
4176
4177static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4178{
4179 struct btrfs_root *root = BTRFS_I(dir)->root;
4180 struct btrfs_trans_handle *trans;
4181 struct inode *inode = d_inode(dentry);
4182 int ret;
4183
4184 trans = __unlink_start_trans(dir);
4185 if (IS_ERR(trans))
4186 return PTR_ERR(trans);
4187
4188 btrfs_record_unlink_dir(trans, BTRFS_I(dir), BTRFS_I(d_inode(dentry)),
4189 0);
4190
4191 ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
4192 BTRFS_I(d_inode(dentry)), dentry->d_name.name,
4193 dentry->d_name.len);
4194 if (ret)
4195 goto out;
4196
4197 if (inode->i_nlink == 0) {
4198 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
4199 if (ret)
4200 goto out;
4201 }
4202
4203out:
4204 btrfs_end_transaction(trans);
4205 btrfs_btree_balance_dirty(root->fs_info);
4206 return ret;
4207}
4208
4209int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4210 struct btrfs_root *root,
4211 struct inode *dir, u64 objectid,
4212 const char *name, int name_len)
4213{
4214 struct btrfs_fs_info *fs_info = root->fs_info;
4215 struct btrfs_path *path;
4216 struct extent_buffer *leaf;
4217 struct btrfs_dir_item *di;
4218 struct btrfs_key key;
4219 u64 index;
4220 int ret;
4221 u64 dir_ino = btrfs_ino(BTRFS_I(dir));
4222
4223 path = btrfs_alloc_path();
4224 if (!path)
4225 return -ENOMEM;
4226
4227 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4228 name, name_len, -1);
4229 if (IS_ERR_OR_NULL(di)) {
4230 if (!di)
4231 ret = -ENOENT;
4232 else
4233 ret = PTR_ERR(di);
4234 goto out;
4235 }
4236
4237 leaf = path->nodes[0];
4238 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4239 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4240 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4241 if (ret) {
4242 btrfs_abort_transaction(trans, ret);
4243 goto out;
4244 }
4245 btrfs_release_path(path);
4246
4247 ret = btrfs_del_root_ref(trans, fs_info, objectid,
4248 root->root_key.objectid, dir_ino,
4249 &index, name, name_len);
4250 if (ret < 0) {
4251 if (ret != -ENOENT) {
4252 btrfs_abort_transaction(trans, ret);
4253 goto out;
4254 }
4255 di = btrfs_search_dir_index_item(root, path, dir_ino,
4256 name, name_len);
4257 if (IS_ERR_OR_NULL(di)) {
4258 if (!di)
4259 ret = -ENOENT;
4260 else
4261 ret = PTR_ERR(di);
4262 btrfs_abort_transaction(trans, ret);
4263 goto out;
4264 }
4265
4266 leaf = path->nodes[0];
4267 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4268 btrfs_release_path(path);
4269 index = key.offset;
4270 }
4271 btrfs_release_path(path);
4272
4273 ret = btrfs_delete_delayed_dir_index(trans, fs_info, BTRFS_I(dir), index);
4274 if (ret) {
4275 btrfs_abort_transaction(trans, ret);
4276 goto out;
4277 }
4278
4279 btrfs_i_size_write(BTRFS_I(dir), dir->i_size - name_len * 2);
4280 inode_inc_iversion(dir);
4281 dir->i_mtime = dir->i_ctime = current_time(dir);
4282 ret = btrfs_update_inode_fallback(trans, root, dir);
4283 if (ret)
4284 btrfs_abort_transaction(trans, ret);
4285out:
4286 btrfs_free_path(path);
4287 return ret;
4288}
4289
4290static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4291{
4292 struct inode *inode = d_inode(dentry);
4293 int err = 0;
4294 struct btrfs_root *root = BTRFS_I(dir)->root;
4295 struct btrfs_trans_handle *trans;
4296 u64 last_unlink_trans;
4297
4298 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4299 return -ENOTEMPTY;
4300 if (btrfs_ino(BTRFS_I(inode)) == BTRFS_FIRST_FREE_OBJECTID)
4301 return -EPERM;
4302
4303 trans = __unlink_start_trans(dir);
4304 if (IS_ERR(trans))
4305 return PTR_ERR(trans);
4306
4307 if (unlikely(btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4308 err = btrfs_unlink_subvol(trans, root, dir,
4309 BTRFS_I(inode)->location.objectid,
4310 dentry->d_name.name,
4311 dentry->d_name.len);
4312 goto out;
4313 }
4314
4315 err = btrfs_orphan_add(trans, BTRFS_I(inode));
4316 if (err)
4317 goto out;
4318
4319 last_unlink_trans = BTRFS_I(inode)->last_unlink_trans;
4320
4321 /* now the directory is empty */
4322 err = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
4323 BTRFS_I(d_inode(dentry)), dentry->d_name.name,
4324 dentry->d_name.len);
4325 if (!err) {
4326 btrfs_i_size_write(BTRFS_I(inode), 0);
4327 /*
4328 * Propagate the last_unlink_trans value of the deleted dir to
4329 * its parent directory. This is to prevent an unrecoverable
4330 * log tree in the case we do something like this:
4331 * 1) create dir foo
4332 * 2) create snapshot under dir foo
4333 * 3) delete the snapshot
4334 * 4) rmdir foo
4335 * 5) mkdir foo
4336 * 6) fsync foo or some file inside foo
4337 */
4338 if (last_unlink_trans >= trans->transid)
4339 BTRFS_I(dir)->last_unlink_trans = last_unlink_trans;
4340 }
4341out:
4342 btrfs_end_transaction(trans);
4343 btrfs_btree_balance_dirty(root->fs_info);
4344
4345 return err;
4346}
4347
4348static int truncate_space_check(struct btrfs_trans_handle *trans,
4349 struct btrfs_root *root,
4350 u64 bytes_deleted)
4351{
4352 struct btrfs_fs_info *fs_info = root->fs_info;
4353 int ret;
4354
4355 /*
4356 * This is only used to apply pressure to the enospc system, we don't
4357 * intend to use this reservation at all.
4358 */
4359 bytes_deleted = btrfs_csum_bytes_to_leaves(fs_info, bytes_deleted);
4360 bytes_deleted *= fs_info->nodesize;
4361 ret = btrfs_block_rsv_add(root, &fs_info->trans_block_rsv,
4362 bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
4363 if (!ret) {
4364 trace_btrfs_space_reservation(fs_info, "transaction",
4365 trans->transid,
4366 bytes_deleted, 1);
4367 trans->bytes_reserved += bytes_deleted;
4368 }
4369 return ret;
4370
4371}
4372
4373/*
4374 * Return this if we need to call truncate_block for the last bit of the
4375 * truncate.
4376 */
4377#define NEED_TRUNCATE_BLOCK 1
4378
4379/*
4380 * this can truncate away extent items, csum items and directory items.
4381 * It starts at a high offset and removes keys until it can't find
4382 * any higher than new_size
4383 *
4384 * csum items that cross the new i_size are truncated to the new size
4385 * as well.
4386 *
4387 * min_type is the minimum key type to truncate down to. If set to 0, this
4388 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4389 */
4390int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4391 struct btrfs_root *root,
4392 struct inode *inode,
4393 u64 new_size, u32 min_type)
4394{
4395 struct btrfs_fs_info *fs_info = root->fs_info;
4396 struct btrfs_path *path;
4397 struct extent_buffer *leaf;
4398 struct btrfs_file_extent_item *fi;
4399 struct btrfs_key key;
4400 struct btrfs_key found_key;
4401 u64 extent_start = 0;
4402 u64 extent_num_bytes = 0;
4403 u64 extent_offset = 0;
4404 u64 item_end = 0;
4405 u64 last_size = new_size;
4406 u32 found_type = (u8)-1;
4407 int found_extent;
4408 int del_item;
4409 int pending_del_nr = 0;
4410 int pending_del_slot = 0;
4411 int extent_type = -1;
4412 int ret;
4413 int err = 0;
4414 u64 ino = btrfs_ino(BTRFS_I(inode));
4415 u64 bytes_deleted = 0;
4416 bool be_nice = false;
4417 bool should_throttle = false;
4418 bool should_end = false;
4419
4420 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4421
4422 /*
4423 * for non-free space inodes and ref cows, we want to back off from
4424 * time to time
4425 */
4426 if (!btrfs_is_free_space_inode(BTRFS_I(inode)) &&
4427 test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4428 be_nice = true;
4429
4430 path = btrfs_alloc_path();
4431 if (!path)
4432 return -ENOMEM;
4433 path->reada = READA_BACK;
4434
4435 /*
4436 * We want to drop from the next block forward in case this new size is
4437 * not block aligned since we will be keeping the last block of the
4438 * extent just the way it is.
4439 */
4440 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4441 root == fs_info->tree_root)
4442 btrfs_drop_extent_cache(BTRFS_I(inode), ALIGN(new_size,
4443 fs_info->sectorsize),
4444 (u64)-1, 0);
4445
4446 /*
4447 * This function is also used to drop the items in the log tree before
4448 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4449 * it is used to drop the loged items. So we shouldn't kill the delayed
4450 * items.
4451 */
4452 if (min_type == 0 && root == BTRFS_I(inode)->root)
4453 btrfs_kill_delayed_inode_items(BTRFS_I(inode));
4454
4455 key.objectid = ino;
4456 key.offset = (u64)-1;
4457 key.type = (u8)-1;
4458
4459search_again:
4460 /*
4461 * with a 16K leaf size and 128MB extents, you can actually queue
4462 * up a huge file in a single leaf. Most of the time that
4463 * bytes_deleted is > 0, it will be huge by the time we get here
4464 */
4465 if (be_nice && bytes_deleted > SZ_32M) {
4466 if (btrfs_should_end_transaction(trans)) {
4467 err = -EAGAIN;
4468 goto error;
4469 }
4470 }
4471
4472
4473 path->leave_spinning = 1;
4474 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4475 if (ret < 0) {
4476 err = ret;
4477 goto out;
4478 }
4479
4480 if (ret > 0) {
4481 /* there are no items in the tree for us to truncate, we're
4482 * done
4483 */
4484 if (path->slots[0] == 0)
4485 goto out;
4486 path->slots[0]--;
4487 }
4488
4489 while (1) {
4490 fi = NULL;
4491 leaf = path->nodes[0];
4492 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4493 found_type = found_key.type;
4494
4495 if (found_key.objectid != ino)
4496 break;
4497
4498 if (found_type < min_type)
4499 break;
4500
4501 item_end = found_key.offset;
4502 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4503 fi = btrfs_item_ptr(leaf, path->slots[0],
4504 struct btrfs_file_extent_item);
4505 extent_type = btrfs_file_extent_type(leaf, fi);
4506 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4507 item_end +=
4508 btrfs_file_extent_num_bytes(leaf, fi);
4509
4510 trace_btrfs_truncate_show_fi_regular(
4511 BTRFS_I(inode), leaf, fi,
4512 found_key.offset);
4513 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4514 item_end += btrfs_file_extent_inline_len(leaf,
4515 path->slots[0], fi);
4516
4517 trace_btrfs_truncate_show_fi_inline(
4518 BTRFS_I(inode), leaf, fi, path->slots[0],
4519 found_key.offset);
4520 }
4521 item_end--;
4522 }
4523 if (found_type > min_type) {
4524 del_item = 1;
4525 } else {
4526 if (item_end < new_size)
4527 break;
4528 if (found_key.offset >= new_size)
4529 del_item = 1;
4530 else
4531 del_item = 0;
4532 }
4533 found_extent = 0;
4534 /* FIXME, shrink the extent if the ref count is only 1 */
4535 if (found_type != BTRFS_EXTENT_DATA_KEY)
4536 goto delete;
4537
4538 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4539 u64 num_dec;
4540 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4541 if (!del_item) {
4542 u64 orig_num_bytes =
4543 btrfs_file_extent_num_bytes(leaf, fi);
4544 extent_num_bytes = ALIGN(new_size -
4545 found_key.offset,
4546 fs_info->sectorsize);
4547 btrfs_set_file_extent_num_bytes(leaf, fi,
4548 extent_num_bytes);
4549 num_dec = (orig_num_bytes -
4550 extent_num_bytes);
4551 if (test_bit(BTRFS_ROOT_REF_COWS,
4552 &root->state) &&
4553 extent_start != 0)
4554 inode_sub_bytes(inode, num_dec);
4555 btrfs_mark_buffer_dirty(leaf);
4556 } else {
4557 extent_num_bytes =
4558 btrfs_file_extent_disk_num_bytes(leaf,
4559 fi);
4560 extent_offset = found_key.offset -
4561 btrfs_file_extent_offset(leaf, fi);
4562
4563 /* FIXME blocksize != 4096 */
4564 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4565 if (extent_start != 0) {
4566 found_extent = 1;
4567 if (test_bit(BTRFS_ROOT_REF_COWS,
4568 &root->state))
4569 inode_sub_bytes(inode, num_dec);
4570 }
4571 }
4572 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4573 /*
4574 * we can't truncate inline items that have had
4575 * special encodings
4576 */
4577 if (!del_item &&
4578 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4579 btrfs_file_extent_other_encoding(leaf, fi) == 0 &&
4580 btrfs_file_extent_compression(leaf, fi) == 0) {
4581 u32 size = (u32)(new_size - found_key.offset);
4582
4583 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4584 size = btrfs_file_extent_calc_inline_size(size);
4585 btrfs_truncate_item(root->fs_info, path, size, 1);
4586 } else if (!del_item) {
4587 /*
4588 * We have to bail so the last_size is set to
4589 * just before this extent.
4590 */
4591 err = NEED_TRUNCATE_BLOCK;
4592 break;
4593 }
4594
4595 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4596 inode_sub_bytes(inode, item_end + 1 - new_size);
4597 }
4598delete:
4599 if (del_item)
4600 last_size = found_key.offset;
4601 else
4602 last_size = new_size;
4603 if (del_item) {
4604 if (!pending_del_nr) {
4605 /* no pending yet, add ourselves */
4606 pending_del_slot = path->slots[0];
4607 pending_del_nr = 1;
4608 } else if (pending_del_nr &&
4609 path->slots[0] + 1 == pending_del_slot) {
4610 /* hop on the pending chunk */
4611 pending_del_nr++;
4612 pending_del_slot = path->slots[0];
4613 } else {
4614 BUG();
4615 }
4616 } else {
4617 break;
4618 }
4619 should_throttle = false;
4620
4621 if (found_extent &&
4622 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4623 root == fs_info->tree_root)) {
4624 btrfs_set_path_blocking(path);
4625 bytes_deleted += extent_num_bytes;
4626 ret = btrfs_free_extent(trans, root, extent_start,
4627 extent_num_bytes, 0,
4628 btrfs_header_owner(leaf),
4629 ino, extent_offset);
4630 BUG_ON(ret);
4631 if (btrfs_should_throttle_delayed_refs(trans, fs_info))
4632 btrfs_async_run_delayed_refs(fs_info,
4633 trans->delayed_ref_updates * 2,
4634 trans->transid, 0);
4635 if (be_nice) {
4636 if (truncate_space_check(trans, root,
4637 extent_num_bytes)) {
4638 should_end = true;
4639 }
4640 if (btrfs_should_throttle_delayed_refs(trans,
4641 fs_info))
4642 should_throttle = true;
4643 }
4644 }
4645
4646 if (found_type == BTRFS_INODE_ITEM_KEY)
4647 break;
4648
4649 if (path->slots[0] == 0 ||
4650 path->slots[0] != pending_del_slot ||
4651 should_throttle || should_end) {
4652 if (pending_del_nr) {
4653 ret = btrfs_del_items(trans, root, path,
4654 pending_del_slot,
4655 pending_del_nr);
4656 if (ret) {
4657 btrfs_abort_transaction(trans, ret);
4658 goto error;
4659 }
4660 pending_del_nr = 0;
4661 }
4662 btrfs_release_path(path);
4663 if (should_throttle) {
4664 unsigned long updates = trans->delayed_ref_updates;
4665 if (updates) {
4666 trans->delayed_ref_updates = 0;
4667 ret = btrfs_run_delayed_refs(trans,
4668 fs_info,
4669 updates * 2);
4670 if (ret && !err)
4671 err = ret;
4672 }
4673 }
4674 /*
4675 * if we failed to refill our space rsv, bail out
4676 * and let the transaction restart
4677 */
4678 if (should_end) {
4679 err = -EAGAIN;
4680 goto error;
4681 }
4682 goto search_again;
4683 } else {
4684 path->slots[0]--;
4685 }
4686 }
4687out:
4688 if (pending_del_nr) {
4689 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4690 pending_del_nr);
4691 if (ret)
4692 btrfs_abort_transaction(trans, ret);
4693 }
4694error:
4695 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
4696 ASSERT(last_size >= new_size);
4697 if (!err && last_size > new_size)
4698 last_size = new_size;
4699 btrfs_ordered_update_i_size(inode, last_size, NULL);
4700 }
4701
4702 btrfs_free_path(path);
4703
4704 if (be_nice && bytes_deleted > SZ_32M) {
4705 unsigned long updates = trans->delayed_ref_updates;
4706 if (updates) {
4707 trans->delayed_ref_updates = 0;
4708 ret = btrfs_run_delayed_refs(trans, fs_info,
4709 updates * 2);
4710 if (ret && !err)
4711 err = ret;
4712 }
4713 }
4714 return err;
4715}
4716
4717/*
4718 * btrfs_truncate_block - read, zero a chunk and write a block
4719 * @inode - inode that we're zeroing
4720 * @from - the offset to start zeroing
4721 * @len - the length to zero, 0 to zero the entire range respective to the
4722 * offset
4723 * @front - zero up to the offset instead of from the offset on
4724 *
4725 * This will find the block for the "from" offset and cow the block and zero the
4726 * part we want to zero. This is used with truncate and hole punching.
4727 */
4728int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
4729 int front)
4730{
4731 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4732 struct address_space *mapping = inode->i_mapping;
4733 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4734 struct btrfs_ordered_extent *ordered;
4735 struct extent_state *cached_state = NULL;
4736 struct extent_changeset *data_reserved = NULL;
4737 char *kaddr;
4738 u32 blocksize = fs_info->sectorsize;
4739 pgoff_t index = from >> PAGE_SHIFT;
4740 unsigned offset = from & (blocksize - 1);
4741 struct page *page;
4742 gfp_t mask = btrfs_alloc_write_mask(mapping);
4743 int ret = 0;
4744 u64 block_start;
4745 u64 block_end;
4746
4747 if ((offset & (blocksize - 1)) == 0 &&
4748 (!len || ((len & (blocksize - 1)) == 0)))
4749 goto out;
4750
4751 block_start = round_down(from, blocksize);
4752 block_end = block_start + blocksize - 1;
4753
4754 ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
4755 block_start, blocksize);
4756 if (ret)
4757 goto out;
4758
4759again:
4760 page = find_or_create_page(mapping, index, mask);
4761 if (!page) {
4762 btrfs_delalloc_release_space(inode, data_reserved,
4763 block_start, blocksize);
4764 btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize);
4765 ret = -ENOMEM;
4766 goto out;
4767 }
4768
4769 if (!PageUptodate(page)) {
4770 ret = btrfs_readpage(NULL, page);
4771 lock_page(page);
4772 if (page->mapping != mapping) {
4773 unlock_page(page);
4774 put_page(page);
4775 goto again;
4776 }
4777 if (!PageUptodate(page)) {
4778 ret = -EIO;
4779 goto out_unlock;
4780 }
4781 }
4782 wait_on_page_writeback(page);
4783
4784 lock_extent_bits(io_tree, block_start, block_end, &cached_state);
4785 set_page_extent_mapped(page);
4786
4787 ordered = btrfs_lookup_ordered_extent(inode, block_start);
4788 if (ordered) {
4789 unlock_extent_cached(io_tree, block_start, block_end,
4790 &cached_state, GFP_NOFS);
4791 unlock_page(page);
4792 put_page(page);
4793 btrfs_start_ordered_extent(inode, ordered, 1);
4794 btrfs_put_ordered_extent(ordered);
4795 goto again;
4796 }
4797
4798 clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end,
4799 EXTENT_DIRTY | EXTENT_DELALLOC |
4800 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4801 0, 0, &cached_state, GFP_NOFS);
4802
4803 ret = btrfs_set_extent_delalloc(inode, block_start, block_end, 0,
4804 &cached_state, 0);
4805 if (ret) {
4806 unlock_extent_cached(io_tree, block_start, block_end,
4807 &cached_state, GFP_NOFS);
4808 goto out_unlock;
4809 }
4810
4811 if (offset != blocksize) {
4812 if (!len)
4813 len = blocksize - offset;
4814 kaddr = kmap(page);
4815 if (front)
4816 memset(kaddr + (block_start - page_offset(page)),
4817 0, offset);
4818 else
4819 memset(kaddr + (block_start - page_offset(page)) + offset,
4820 0, len);
4821 flush_dcache_page(page);
4822 kunmap(page);
4823 }
4824 ClearPageChecked(page);
4825 set_page_dirty(page);
4826 unlock_extent_cached(io_tree, block_start, block_end, &cached_state,
4827 GFP_NOFS);
4828
4829out_unlock:
4830 if (ret)
4831 btrfs_delalloc_release_space(inode, data_reserved, block_start,
4832 blocksize);
4833 btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize);
4834 unlock_page(page);
4835 put_page(page);
4836out:
4837 extent_changeset_free(data_reserved);
4838 return ret;
4839}
4840
4841static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4842 u64 offset, u64 len)
4843{
4844 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4845 struct btrfs_trans_handle *trans;
4846 int ret;
4847
4848 /*
4849 * Still need to make sure the inode looks like it's been updated so
4850 * that any holes get logged if we fsync.
4851 */
4852 if (btrfs_fs_incompat(fs_info, NO_HOLES)) {
4853 BTRFS_I(inode)->last_trans = fs_info->generation;
4854 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4855 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4856 return 0;
4857 }
4858
4859 /*
4860 * 1 - for the one we're dropping
4861 * 1 - for the one we're adding
4862 * 1 - for updating the inode.
4863 */
4864 trans = btrfs_start_transaction(root, 3);
4865 if (IS_ERR(trans))
4866 return PTR_ERR(trans);
4867
4868 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4869 if (ret) {
4870 btrfs_abort_transaction(trans, ret);
4871 btrfs_end_transaction(trans);
4872 return ret;
4873 }
4874
4875 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(BTRFS_I(inode)),
4876 offset, 0, 0, len, 0, len, 0, 0, 0);
4877 if (ret)
4878 btrfs_abort_transaction(trans, ret);
4879 else
4880 btrfs_update_inode(trans, root, inode);
4881 btrfs_end_transaction(trans);
4882 return ret;
4883}
4884
4885/*
4886 * This function puts in dummy file extents for the area we're creating a hole
4887 * for. So if we are truncating this file to a larger size we need to insert
4888 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4889 * the range between oldsize and size
4890 */
4891int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4892{
4893 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4894 struct btrfs_root *root = BTRFS_I(inode)->root;
4895 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4896 struct extent_map *em = NULL;
4897 struct extent_state *cached_state = NULL;
4898 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4899 u64 hole_start = ALIGN(oldsize, fs_info->sectorsize);
4900 u64 block_end = ALIGN(size, fs_info->sectorsize);
4901 u64 last_byte;
4902 u64 cur_offset;
4903 u64 hole_size;
4904 int err = 0;
4905
4906 /*
4907 * If our size started in the middle of a block we need to zero out the
4908 * rest of the block before we expand the i_size, otherwise we could
4909 * expose stale data.
4910 */
4911 err = btrfs_truncate_block(inode, oldsize, 0, 0);
4912 if (err)
4913 return err;
4914
4915 if (size <= hole_start)
4916 return 0;
4917
4918 while (1) {
4919 struct btrfs_ordered_extent *ordered;
4920
4921 lock_extent_bits(io_tree, hole_start, block_end - 1,
4922 &cached_state);
4923 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), hole_start,
4924 block_end - hole_start);
4925 if (!ordered)
4926 break;
4927 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4928 &cached_state, GFP_NOFS);
4929 btrfs_start_ordered_extent(inode, ordered, 1);
4930 btrfs_put_ordered_extent(ordered);
4931 }
4932
4933 cur_offset = hole_start;
4934 while (1) {
4935 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset,
4936 block_end - cur_offset, 0);
4937 if (IS_ERR(em)) {
4938 err = PTR_ERR(em);
4939 em = NULL;
4940 break;
4941 }
4942 last_byte = min(extent_map_end(em), block_end);
4943 last_byte = ALIGN(last_byte, fs_info->sectorsize);
4944 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4945 struct extent_map *hole_em;
4946 hole_size = last_byte - cur_offset;
4947
4948 err = maybe_insert_hole(root, inode, cur_offset,
4949 hole_size);
4950 if (err)
4951 break;
4952 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
4953 cur_offset + hole_size - 1, 0);
4954 hole_em = alloc_extent_map();
4955 if (!hole_em) {
4956 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4957 &BTRFS_I(inode)->runtime_flags);
4958 goto next;
4959 }
4960 hole_em->start = cur_offset;
4961 hole_em->len = hole_size;
4962 hole_em->orig_start = cur_offset;
4963
4964 hole_em->block_start = EXTENT_MAP_HOLE;
4965 hole_em->block_len = 0;
4966 hole_em->orig_block_len = 0;
4967 hole_em->ram_bytes = hole_size;
4968 hole_em->bdev = fs_info->fs_devices->latest_bdev;
4969 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4970 hole_em->generation = fs_info->generation;
4971
4972 while (1) {
4973 write_lock(&em_tree->lock);
4974 err = add_extent_mapping(em_tree, hole_em, 1);
4975 write_unlock(&em_tree->lock);
4976 if (err != -EEXIST)
4977 break;
4978 btrfs_drop_extent_cache(BTRFS_I(inode),
4979 cur_offset,
4980 cur_offset +
4981 hole_size - 1, 0);
4982 }
4983 free_extent_map(hole_em);
4984 }
4985next:
4986 free_extent_map(em);
4987 em = NULL;
4988 cur_offset = last_byte;
4989 if (cur_offset >= block_end)
4990 break;
4991 }
4992 free_extent_map(em);
4993 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4994 GFP_NOFS);
4995 return err;
4996}
4997
4998static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4999{
5000 struct btrfs_root *root = BTRFS_I(inode)->root;
5001 struct btrfs_trans_handle *trans;
5002 loff_t oldsize = i_size_read(inode);
5003 loff_t newsize = attr->ia_size;
5004 int mask = attr->ia_valid;
5005 int ret;
5006
5007 /*
5008 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
5009 * special case where we need to update the times despite not having
5010 * these flags set. For all other operations the VFS set these flags
5011 * explicitly if it wants a timestamp update.
5012 */
5013 if (newsize != oldsize) {
5014 inode_inc_iversion(inode);
5015 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
5016 inode->i_ctime = inode->i_mtime =
5017 current_time(inode);
5018 }
5019
5020 if (newsize > oldsize) {
5021 /*
5022 * Don't do an expanding truncate while snapshotting is ongoing.
5023 * This is to ensure the snapshot captures a fully consistent
5024 * state of this file - if the snapshot captures this expanding
5025 * truncation, it must capture all writes that happened before
5026 * this truncation.
5027 */
5028 btrfs_wait_for_snapshot_creation(root);
5029 ret = btrfs_cont_expand(inode, oldsize, newsize);
5030 if (ret) {
5031 btrfs_end_write_no_snapshotting(root);
5032 return ret;
5033 }
5034
5035 trans = btrfs_start_transaction(root, 1);
5036 if (IS_ERR(trans)) {
5037 btrfs_end_write_no_snapshotting(root);
5038 return PTR_ERR(trans);
5039 }
5040
5041 i_size_write(inode, newsize);
5042 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
5043 pagecache_isize_extended(inode, oldsize, newsize);
5044 ret = btrfs_update_inode(trans, root, inode);
5045 btrfs_end_write_no_snapshotting(root);
5046 btrfs_end_transaction(trans);
5047 } else {
5048
5049 /*
5050 * We're truncating a file that used to have good data down to
5051 * zero. Make sure it gets into the ordered flush list so that
5052 * any new writes get down to disk quickly.
5053 */
5054 if (newsize == 0)
5055 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
5056 &BTRFS_I(inode)->runtime_flags);
5057
5058 /*
5059 * 1 for the orphan item we're going to add
5060 * 1 for the orphan item deletion.
5061 */
5062 trans = btrfs_start_transaction(root, 2);
5063 if (IS_ERR(trans))
5064 return PTR_ERR(trans);
5065
5066 /*
5067 * We need to do this in case we fail at _any_ point during the
5068 * actual truncate. Once we do the truncate_setsize we could
5069 * invalidate pages which forces any outstanding ordered io to
5070 * be instantly completed which will give us extents that need
5071 * to be truncated. If we fail to get an orphan inode down we
5072 * could have left over extents that were never meant to live,
5073 * so we need to guarantee from this point on that everything
5074 * will be consistent.
5075 */
5076 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
5077 btrfs_end_transaction(trans);
5078 if (ret)
5079 return ret;
5080
5081 /* we don't support swapfiles, so vmtruncate shouldn't fail */
5082 truncate_setsize(inode, newsize);
5083
5084 /* Disable nonlocked read DIO to avoid the end less truncate */
5085 btrfs_inode_block_unlocked_dio(BTRFS_I(inode));
5086 inode_dio_wait(inode);
5087 btrfs_inode_resume_unlocked_dio(BTRFS_I(inode));
5088
5089 ret = btrfs_truncate(inode);
5090 if (ret && inode->i_nlink) {
5091 int err;
5092
5093 /* To get a stable disk_i_size */
5094 err = btrfs_wait_ordered_range(inode, 0, (u64)-1);
5095 if (err) {
5096 btrfs_orphan_del(NULL, BTRFS_I(inode));
5097 return err;
5098 }
5099
5100 /*
5101 * failed to truncate, disk_i_size is only adjusted down
5102 * as we remove extents, so it should represent the true
5103 * size of the inode, so reset the in memory size and
5104 * delete our orphan entry.
5105 */
5106 trans = btrfs_join_transaction(root);
5107 if (IS_ERR(trans)) {
5108 btrfs_orphan_del(NULL, BTRFS_I(inode));
5109 return ret;
5110 }
5111 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
5112 err = btrfs_orphan_del(trans, BTRFS_I(inode));
5113 if (err)
5114 btrfs_abort_transaction(trans, err);
5115 btrfs_end_transaction(trans);
5116 }
5117 }
5118
5119 return ret;
5120}
5121
5122static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
5123{
5124 struct inode *inode = d_inode(dentry);
5125 struct btrfs_root *root = BTRFS_I(inode)->root;
5126 int err;
5127
5128 if (btrfs_root_readonly(root))
5129 return -EROFS;
5130
5131 err = setattr_prepare(dentry, attr);
5132 if (err)
5133 return err;
5134
5135 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
5136 err = btrfs_setsize(inode, attr);
5137 if (err)
5138 return err;
5139 }
5140
5141 if (attr->ia_valid) {
5142 setattr_copy(inode, attr);
5143 inode_inc_iversion(inode);
5144 err = btrfs_dirty_inode(inode);
5145
5146 if (!err && attr->ia_valid & ATTR_MODE)
5147 err = posix_acl_chmod(inode, inode->i_mode);
5148 }
5149
5150 return err;
5151}
5152
5153/*
5154 * While truncating the inode pages during eviction, we get the VFS calling
5155 * btrfs_invalidatepage() against each page of the inode. This is slow because
5156 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
5157 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
5158 * extent_state structures over and over, wasting lots of time.
5159 *
5160 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
5161 * those expensive operations on a per page basis and do only the ordered io
5162 * finishing, while we release here the extent_map and extent_state structures,
5163 * without the excessive merging and splitting.
5164 */
5165static void evict_inode_truncate_pages(struct inode *inode)
5166{
5167 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5168 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
5169 struct rb_node *node;
5170
5171 ASSERT(inode->i_state & I_FREEING);
5172 truncate_inode_pages_final(&inode->i_data);
5173
5174 write_lock(&map_tree->lock);
5175 while (!RB_EMPTY_ROOT(&map_tree->map)) {
5176 struct extent_map *em;
5177
5178 node = rb_first(&map_tree->map);
5179 em = rb_entry(node, struct extent_map, rb_node);
5180 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
5181 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
5182 remove_extent_mapping(map_tree, em);
5183 free_extent_map(em);
5184 if (need_resched()) {
5185 write_unlock(&map_tree->lock);
5186 cond_resched();
5187 write_lock(&map_tree->lock);
5188 }
5189 }
5190 write_unlock(&map_tree->lock);
5191
5192 /*
5193 * Keep looping until we have no more ranges in the io tree.
5194 * We can have ongoing bios started by readpages (called from readahead)
5195 * that have their endio callback (extent_io.c:end_bio_extent_readpage)
5196 * still in progress (unlocked the pages in the bio but did not yet
5197 * unlocked the ranges in the io tree). Therefore this means some
5198 * ranges can still be locked and eviction started because before
5199 * submitting those bios, which are executed by a separate task (work
5200 * queue kthread), inode references (inode->i_count) were not taken
5201 * (which would be dropped in the end io callback of each bio).
5202 * Therefore here we effectively end up waiting for those bios and
5203 * anyone else holding locked ranges without having bumped the inode's
5204 * reference count - if we don't do it, when they access the inode's
5205 * io_tree to unlock a range it may be too late, leading to an
5206 * use-after-free issue.
5207 */
5208 spin_lock(&io_tree->lock);
5209 while (!RB_EMPTY_ROOT(&io_tree->state)) {
5210 struct extent_state *state;
5211 struct extent_state *cached_state = NULL;
5212 u64 start;
5213 u64 end;
5214
5215 node = rb_first(&io_tree->state);
5216 state = rb_entry(node, struct extent_state, rb_node);
5217 start = state->start;
5218 end = state->end;
5219 spin_unlock(&io_tree->lock);
5220
5221 lock_extent_bits(io_tree, start, end, &cached_state);
5222
5223 /*
5224 * If still has DELALLOC flag, the extent didn't reach disk,
5225 * and its reserved space won't be freed by delayed_ref.
5226 * So we need to free its reserved space here.
5227 * (Refer to comment in btrfs_invalidatepage, case 2)
5228 *
5229 * Note, end is the bytenr of last byte, so we need + 1 here.
5230 */
5231 if (state->state & EXTENT_DELALLOC)
5232 btrfs_qgroup_free_data(inode, NULL, start, end - start + 1);
5233
5234 clear_extent_bit(io_tree, start, end,
5235 EXTENT_LOCKED | EXTENT_DIRTY |
5236 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
5237 EXTENT_DEFRAG, 1, 1,
5238 &cached_state, GFP_NOFS);
5239
5240 cond_resched();
5241 spin_lock(&io_tree->lock);
5242 }
5243 spin_unlock(&io_tree->lock);
5244}
5245
5246void btrfs_evict_inode(struct inode *inode)
5247{
5248 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5249 struct btrfs_trans_handle *trans;
5250 struct btrfs_root *root = BTRFS_I(inode)->root;
5251 struct btrfs_block_rsv *rsv, *global_rsv;
5252 int steal_from_global = 0;
5253 u64 min_size;
5254 int ret;
5255
5256 trace_btrfs_inode_evict(inode);
5257
5258 if (!root) {
5259 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
5260 return;
5261 }
5262
5263 min_size = btrfs_calc_trunc_metadata_size(fs_info, 1);
5264
5265 evict_inode_truncate_pages(inode);
5266
5267 if (inode->i_nlink &&
5268 ((btrfs_root_refs(&root->root_item) != 0 &&
5269 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5270 btrfs_is_free_space_inode(BTRFS_I(inode))))
5271 goto no_delete;
5272
5273 if (is_bad_inode(inode)) {
5274 btrfs_orphan_del(NULL, BTRFS_I(inode));
5275 goto no_delete;
5276 }
5277 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
5278 if (!special_file(inode->i_mode))
5279 btrfs_wait_ordered_range(inode, 0, (u64)-1);
5280
5281 btrfs_free_io_failure_record(BTRFS_I(inode), 0, (u64)-1);
5282
5283 if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
5284 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
5285 &BTRFS_I(inode)->runtime_flags));
5286 goto no_delete;
5287 }
5288
5289 if (inode->i_nlink > 0) {
5290 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5291 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5292 goto no_delete;
5293 }
5294
5295 ret = btrfs_commit_inode_delayed_inode(BTRFS_I(inode));
5296 if (ret) {
5297 btrfs_orphan_del(NULL, BTRFS_I(inode));
5298 goto no_delete;
5299 }
5300
5301 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
5302 if (!rsv) {
5303 btrfs_orphan_del(NULL, BTRFS_I(inode));
5304 goto no_delete;
5305 }
5306 rsv->size = min_size;
5307 rsv->failfast = 1;
5308 global_rsv = &fs_info->global_block_rsv;
5309
5310 btrfs_i_size_write(BTRFS_I(inode), 0);
5311
5312 /*
5313 * This is a bit simpler than btrfs_truncate since we've already
5314 * reserved our space for our orphan item in the unlink, so we just
5315 * need to reserve some slack space in case we add bytes and update
5316 * inode item when doing the truncate.
5317 */
5318 while (1) {
5319 ret = btrfs_block_rsv_refill(root, rsv, min_size,
5320 BTRFS_RESERVE_FLUSH_LIMIT);
5321
5322 /*
5323 * Try and steal from the global reserve since we will
5324 * likely not use this space anyway, we want to try as
5325 * hard as possible to get this to work.
5326 */
5327 if (ret)
5328 steal_from_global++;
5329 else
5330 steal_from_global = 0;
5331 ret = 0;
5332
5333 /*
5334 * steal_from_global == 0: we reserved stuff, hooray!
5335 * steal_from_global == 1: we didn't reserve stuff, boo!
5336 * steal_from_global == 2: we've committed, still not a lot of
5337 * room but maybe we'll have room in the global reserve this
5338 * time.
5339 * steal_from_global == 3: abandon all hope!
5340 */
5341 if (steal_from_global > 2) {
5342 btrfs_warn(fs_info,
5343 "Could not get space for a delete, will truncate on mount %d",
5344 ret);
5345 btrfs_orphan_del(NULL, BTRFS_I(inode));
5346 btrfs_free_block_rsv(fs_info, rsv);
5347 goto no_delete;
5348 }
5349
5350 trans = btrfs_join_transaction(root);
5351 if (IS_ERR(trans)) {
5352 btrfs_orphan_del(NULL, BTRFS_I(inode));
5353 btrfs_free_block_rsv(fs_info, rsv);
5354 goto no_delete;
5355 }
5356
5357 /*
5358 * We can't just steal from the global reserve, we need to make
5359 * sure there is room to do it, if not we need to commit and try
5360 * again.
5361 */
5362 if (steal_from_global) {
5363 if (!btrfs_check_space_for_delayed_refs(trans, fs_info))
5364 ret = btrfs_block_rsv_migrate(global_rsv, rsv,
5365 min_size, 0);
5366 else
5367 ret = -ENOSPC;
5368 }
5369
5370 /*
5371 * Couldn't steal from the global reserve, we have too much
5372 * pending stuff built up, commit the transaction and try it
5373 * again.
5374 */
5375 if (ret) {
5376 ret = btrfs_commit_transaction(trans);
5377 if (ret) {
5378 btrfs_orphan_del(NULL, BTRFS_I(inode));
5379 btrfs_free_block_rsv(fs_info, rsv);
5380 goto no_delete;
5381 }
5382 continue;
5383 } else {
5384 steal_from_global = 0;
5385 }
5386
5387 trans->block_rsv = rsv;
5388
5389 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5390 if (ret != -ENOSPC && ret != -EAGAIN)
5391 break;
5392
5393 trans->block_rsv = &fs_info->trans_block_rsv;
5394 btrfs_end_transaction(trans);
5395 trans = NULL;
5396 btrfs_btree_balance_dirty(fs_info);
5397 }
5398
5399 btrfs_free_block_rsv(fs_info, rsv);
5400
5401 /*
5402 * Errors here aren't a big deal, it just means we leave orphan items
5403 * in the tree. They will be cleaned up on the next mount.
5404 */
5405 if (ret == 0) {
5406 trans->block_rsv = root->orphan_block_rsv;
5407 btrfs_orphan_del(trans, BTRFS_I(inode));
5408 } else {
5409 btrfs_orphan_del(NULL, BTRFS_I(inode));
5410 }
5411
5412 trans->block_rsv = &fs_info->trans_block_rsv;
5413 if (!(root == fs_info->tree_root ||
5414 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5415 btrfs_return_ino(root, btrfs_ino(BTRFS_I(inode)));
5416
5417 btrfs_end_transaction(trans);
5418 btrfs_btree_balance_dirty(fs_info);
5419no_delete:
5420 btrfs_remove_delayed_node(BTRFS_I(inode));
5421 clear_inode(inode);
5422}
5423
5424/*
5425 * this returns the key found in the dir entry in the location pointer.
5426 * If no dir entries were found, location->objectid is 0.
5427 */
5428static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5429 struct btrfs_key *location)
5430{
5431 const char *name = dentry->d_name.name;
5432 int namelen = dentry->d_name.len;
5433 struct btrfs_dir_item *di;
5434 struct btrfs_path *path;
5435 struct btrfs_root *root = BTRFS_I(dir)->root;
5436 int ret = 0;
5437
5438 path = btrfs_alloc_path();
5439 if (!path)
5440 return -ENOMEM;
5441
5442 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(BTRFS_I(dir)),
5443 name, namelen, 0);
5444 if (IS_ERR(di))
5445 ret = PTR_ERR(di);
5446
5447 if (IS_ERR_OR_NULL(di))
5448 goto out_err;
5449
5450 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5451 if (location->type != BTRFS_INODE_ITEM_KEY &&
5452 location->type != BTRFS_ROOT_ITEM_KEY) {
5453 btrfs_warn(root->fs_info,
5454"%s gets something invalid in DIR_ITEM (name %s, directory ino %llu, location(%llu %u %llu))",
5455 __func__, name, btrfs_ino(BTRFS_I(dir)),
5456 location->objectid, location->type, location->offset);
5457 goto out_err;
5458 }
5459out:
5460 btrfs_free_path(path);
5461 return ret;
5462out_err:
5463 location->objectid = 0;
5464 goto out;
5465}
5466
5467/*
5468 * when we hit a tree root in a directory, the btrfs part of the inode
5469 * needs to be changed to reflect the root directory of the tree root. This
5470 * is kind of like crossing a mount point.
5471 */
5472static int fixup_tree_root_location(struct btrfs_fs_info *fs_info,
5473 struct inode *dir,
5474 struct dentry *dentry,
5475 struct btrfs_key *location,
5476 struct btrfs_root **sub_root)
5477{
5478 struct btrfs_path *path;
5479 struct btrfs_root *new_root;
5480 struct btrfs_root_ref *ref;
5481 struct extent_buffer *leaf;
5482 struct btrfs_key key;
5483 int ret;
5484 int err = 0;
5485
5486 path = btrfs_alloc_path();
5487 if (!path) {
5488 err = -ENOMEM;
5489 goto out;
5490 }
5491
5492 err = -ENOENT;
5493 key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5494 key.type = BTRFS_ROOT_REF_KEY;
5495 key.offset = location->objectid;
5496
5497 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
5498 if (ret) {
5499 if (ret < 0)
5500 err = ret;
5501 goto out;
5502 }
5503
5504 leaf = path->nodes[0];
5505 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5506 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(BTRFS_I(dir)) ||
5507 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5508 goto out;
5509
5510 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5511 (unsigned long)(ref + 1),
5512 dentry->d_name.len);
5513 if (ret)
5514 goto out;
5515
5516 btrfs_release_path(path);
5517
5518 new_root = btrfs_read_fs_root_no_name(fs_info, location);
5519 if (IS_ERR(new_root)) {
5520 err = PTR_ERR(new_root);
5521 goto out;
5522 }
5523
5524 *sub_root = new_root;
5525 location->objectid = btrfs_root_dirid(&new_root->root_item);
5526 location->type = BTRFS_INODE_ITEM_KEY;
5527 location->offset = 0;
5528 err = 0;
5529out:
5530 btrfs_free_path(path);
5531 return err;
5532}
5533
5534static void inode_tree_add(struct inode *inode)
5535{
5536 struct btrfs_root *root = BTRFS_I(inode)->root;
5537 struct btrfs_inode *entry;
5538 struct rb_node **p;
5539 struct rb_node *parent;
5540 struct rb_node *new = &BTRFS_I(inode)->rb_node;
5541 u64 ino = btrfs_ino(BTRFS_I(inode));
5542
5543 if (inode_unhashed(inode))
5544 return;
5545 parent = NULL;
5546 spin_lock(&root->inode_lock);
5547 p = &root->inode_tree.rb_node;
5548 while (*p) {
5549 parent = *p;
5550 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5551
5552 if (ino < btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5553 p = &parent->rb_left;
5554 else if (ino > btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5555 p = &parent->rb_right;
5556 else {
5557 WARN_ON(!(entry->vfs_inode.i_state &
5558 (I_WILL_FREE | I_FREEING)));
5559 rb_replace_node(parent, new, &root->inode_tree);
5560 RB_CLEAR_NODE(parent);
5561 spin_unlock(&root->inode_lock);
5562 return;
5563 }
5564 }
5565 rb_link_node(new, parent, p);
5566 rb_insert_color(new, &root->inode_tree);
5567 spin_unlock(&root->inode_lock);
5568}
5569
5570static void inode_tree_del(struct inode *inode)
5571{
5572 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5573 struct btrfs_root *root = BTRFS_I(inode)->root;
5574 int empty = 0;
5575
5576 spin_lock(&root->inode_lock);
5577 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5578 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5579 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5580 empty = RB_EMPTY_ROOT(&root->inode_tree);
5581 }
5582 spin_unlock(&root->inode_lock);
5583
5584 if (empty && btrfs_root_refs(&root->root_item) == 0) {
5585 synchronize_srcu(&fs_info->subvol_srcu);
5586 spin_lock(&root->inode_lock);
5587 empty = RB_EMPTY_ROOT(&root->inode_tree);
5588 spin_unlock(&root->inode_lock);
5589 if (empty)
5590 btrfs_add_dead_root(root);
5591 }
5592}
5593
5594void btrfs_invalidate_inodes(struct btrfs_root *root)
5595{
5596 struct btrfs_fs_info *fs_info = root->fs_info;
5597 struct rb_node *node;
5598 struct rb_node *prev;
5599 struct btrfs_inode *entry;
5600 struct inode *inode;
5601 u64 objectid = 0;
5602
5603 if (!test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
5604 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
5605
5606 spin_lock(&root->inode_lock);
5607again:
5608 node = root->inode_tree.rb_node;
5609 prev = NULL;
5610 while (node) {
5611 prev = node;
5612 entry = rb_entry(node, struct btrfs_inode, rb_node);
5613
5614 if (objectid < btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5615 node = node->rb_left;
5616 else if (objectid > btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5617 node = node->rb_right;
5618 else
5619 break;
5620 }
5621 if (!node) {
5622 while (prev) {
5623 entry = rb_entry(prev, struct btrfs_inode, rb_node);
5624 if (objectid <= btrfs_ino(BTRFS_I(&entry->vfs_inode))) {
5625 node = prev;
5626 break;
5627 }
5628 prev = rb_next(prev);
5629 }
5630 }
5631 while (node) {
5632 entry = rb_entry(node, struct btrfs_inode, rb_node);
5633 objectid = btrfs_ino(BTRFS_I(&entry->vfs_inode)) + 1;
5634 inode = igrab(&entry->vfs_inode);
5635 if (inode) {
5636 spin_unlock(&root->inode_lock);
5637 if (atomic_read(&inode->i_count) > 1)
5638 d_prune_aliases(inode);
5639 /*
5640 * btrfs_drop_inode will have it removed from
5641 * the inode cache when its usage count
5642 * hits zero.
5643 */
5644 iput(inode);
5645 cond_resched();
5646 spin_lock(&root->inode_lock);
5647 goto again;
5648 }
5649
5650 if (cond_resched_lock(&root->inode_lock))
5651 goto again;
5652
5653 node = rb_next(node);
5654 }
5655 spin_unlock(&root->inode_lock);
5656}
5657
5658static int btrfs_init_locked_inode(struct inode *inode, void *p)
5659{
5660 struct btrfs_iget_args *args = p;
5661 inode->i_ino = args->location->objectid;
5662 memcpy(&BTRFS_I(inode)->location, args->location,
5663 sizeof(*args->location));
5664 BTRFS_I(inode)->root = args->root;
5665 return 0;
5666}
5667
5668static int btrfs_find_actor(struct inode *inode, void *opaque)
5669{
5670 struct btrfs_iget_args *args = opaque;
5671 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5672 args->root == BTRFS_I(inode)->root;
5673}
5674
5675static struct inode *btrfs_iget_locked(struct super_block *s,
5676 struct btrfs_key *location,
5677 struct btrfs_root *root)
5678{
5679 struct inode *inode;
5680 struct btrfs_iget_args args;
5681 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5682
5683 args.location = location;
5684 args.root = root;
5685
5686 inode = iget5_locked(s, hashval, btrfs_find_actor,
5687 btrfs_init_locked_inode,
5688 (void *)&args);
5689 return inode;
5690}
5691
5692/* Get an inode object given its location and corresponding root.
5693 * Returns in *is_new if the inode was read from disk
5694 */
5695struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5696 struct btrfs_root *root, int *new)
5697{
5698 struct inode *inode;
5699
5700 inode = btrfs_iget_locked(s, location, root);
5701 if (!inode)
5702 return ERR_PTR(-ENOMEM);
5703
5704 if (inode->i_state & I_NEW) {
5705 int ret;
5706
5707 ret = btrfs_read_locked_inode(inode);
5708 if (!is_bad_inode(inode)) {
5709 inode_tree_add(inode);
5710 unlock_new_inode(inode);
5711 if (new)
5712 *new = 1;
5713 } else {
5714 unlock_new_inode(inode);
5715 iput(inode);
5716 ASSERT(ret < 0);
5717 inode = ERR_PTR(ret < 0 ? ret : -ESTALE);
5718 }
5719 }
5720
5721 return inode;
5722}
5723
5724static struct inode *new_simple_dir(struct super_block *s,
5725 struct btrfs_key *key,
5726 struct btrfs_root *root)
5727{
5728 struct inode *inode = new_inode(s);
5729
5730 if (!inode)
5731 return ERR_PTR(-ENOMEM);
5732
5733 BTRFS_I(inode)->root = root;
5734 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5735 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5736
5737 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5738 inode->i_op = &btrfs_dir_ro_inode_operations;
5739 inode->i_opflags &= ~IOP_XATTR;
5740 inode->i_fop = &simple_dir_operations;
5741 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5742 inode->i_mtime = current_time(inode);
5743 inode->i_atime = inode->i_mtime;
5744 inode->i_ctime = inode->i_mtime;
5745 BTRFS_I(inode)->i_otime = inode->i_mtime;
5746
5747 return inode;
5748}
5749
5750struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5751{
5752 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
5753 struct inode *inode;
5754 struct btrfs_root *root = BTRFS_I(dir)->root;
5755 struct btrfs_root *sub_root = root;
5756 struct btrfs_key location;
5757 int index;
5758 int ret = 0;
5759
5760 if (dentry->d_name.len > BTRFS_NAME_LEN)
5761 return ERR_PTR(-ENAMETOOLONG);
5762
5763 ret = btrfs_inode_by_name(dir, dentry, &location);
5764 if (ret < 0)
5765 return ERR_PTR(ret);
5766
5767 if (location.objectid == 0)
5768 return ERR_PTR(-ENOENT);
5769
5770 if (location.type == BTRFS_INODE_ITEM_KEY) {
5771 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5772 return inode;
5773 }
5774
5775 index = srcu_read_lock(&fs_info->subvol_srcu);
5776 ret = fixup_tree_root_location(fs_info, dir, dentry,
5777 &location, &sub_root);
5778 if (ret < 0) {
5779 if (ret != -ENOENT)
5780 inode = ERR_PTR(ret);
5781 else
5782 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5783 } else {
5784 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5785 }
5786 srcu_read_unlock(&fs_info->subvol_srcu, index);
5787
5788 if (!IS_ERR(inode) && root != sub_root) {
5789 down_read(&fs_info->cleanup_work_sem);
5790 if (!sb_rdonly(inode->i_sb))
5791 ret = btrfs_orphan_cleanup(sub_root);
5792 up_read(&fs_info->cleanup_work_sem);
5793 if (ret) {
5794 iput(inode);
5795 inode = ERR_PTR(ret);
5796 }
5797 }
5798
5799 return inode;
5800}
5801
5802static int btrfs_dentry_delete(const struct dentry *dentry)
5803{
5804 struct btrfs_root *root;
5805 struct inode *inode = d_inode(dentry);
5806
5807 if (!inode && !IS_ROOT(dentry))
5808 inode = d_inode(dentry->d_parent);
5809
5810 if (inode) {
5811 root = BTRFS_I(inode)->root;
5812 if (btrfs_root_refs(&root->root_item) == 0)
5813 return 1;
5814
5815 if (btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5816 return 1;
5817 }
5818 return 0;
5819}
5820
5821static void btrfs_dentry_release(struct dentry *dentry)
5822{
5823 kfree(dentry->d_fsdata);
5824}
5825
5826static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5827 unsigned int flags)
5828{
5829 struct inode *inode;
5830
5831 inode = btrfs_lookup_dentry(dir, dentry);
5832 if (IS_ERR(inode)) {
5833 if (PTR_ERR(inode) == -ENOENT)
5834 inode = NULL;
5835 else
5836 return ERR_CAST(inode);
5837 }
5838
5839 return d_splice_alias(inode, dentry);
5840}
5841
5842unsigned char btrfs_filetype_table[] = {
5843 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5844};
5845
5846/*
5847 * All this infrastructure exists because dir_emit can fault, and we are holding
5848 * the tree lock when doing readdir. For now just allocate a buffer and copy
5849 * our information into that, and then dir_emit from the buffer. This is
5850 * similar to what NFS does, only we don't keep the buffer around in pagecache
5851 * because I'm afraid I'll mess that up. Long term we need to make filldir do
5852 * copy_to_user_inatomic so we don't have to worry about page faulting under the
5853 * tree lock.
5854 */
5855static int btrfs_opendir(struct inode *inode, struct file *file)
5856{
5857 struct btrfs_file_private *private;
5858
5859 private = kzalloc(sizeof(struct btrfs_file_private), GFP_KERNEL);
5860 if (!private)
5861 return -ENOMEM;
5862 private->filldir_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
5863 if (!private->filldir_buf) {
5864 kfree(private);
5865 return -ENOMEM;
5866 }
5867 file->private_data = private;
5868 return 0;
5869}
5870
5871struct dir_entry {
5872 u64 ino;
5873 u64 offset;
5874 unsigned type;
5875 int name_len;
5876};
5877
5878static int btrfs_filldir(void *addr, int entries, struct dir_context *ctx)
5879{
5880 while (entries--) {
5881 struct dir_entry *entry = addr;
5882 char *name = (char *)(entry + 1);
5883
5884 ctx->pos = entry->offset;
5885 if (!dir_emit(ctx, name, entry->name_len, entry->ino,
5886 entry->type))
5887 return 1;
5888 addr += sizeof(struct dir_entry) + entry->name_len;
5889 ctx->pos++;
5890 }
5891 return 0;
5892}
5893
5894static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5895{
5896 struct inode *inode = file_inode(file);
5897 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5898 struct btrfs_root *root = BTRFS_I(inode)->root;
5899 struct btrfs_file_private *private = file->private_data;
5900 struct btrfs_dir_item *di;
5901 struct btrfs_key key;
5902 struct btrfs_key found_key;
5903 struct btrfs_path *path;
5904 void *addr;
5905 struct list_head ins_list;
5906 struct list_head del_list;
5907 int ret;
5908 struct extent_buffer *leaf;
5909 int slot;
5910 char *name_ptr;
5911 int name_len;
5912 int entries = 0;
5913 int total_len = 0;
5914 bool put = false;
5915 struct btrfs_key location;
5916
5917 if (!dir_emit_dots(file, ctx))
5918 return 0;
5919
5920 path = btrfs_alloc_path();
5921 if (!path)
5922 return -ENOMEM;
5923
5924 addr = private->filldir_buf;
5925 path->reada = READA_FORWARD;
5926
5927 INIT_LIST_HEAD(&ins_list);
5928 INIT_LIST_HEAD(&del_list);
5929 put = btrfs_readdir_get_delayed_items(inode, &ins_list, &del_list);
5930
5931again:
5932 key.type = BTRFS_DIR_INDEX_KEY;
5933 key.offset = ctx->pos;
5934 key.objectid = btrfs_ino(BTRFS_I(inode));
5935
5936 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5937 if (ret < 0)
5938 goto err;
5939
5940 while (1) {
5941 struct dir_entry *entry;
5942
5943 leaf = path->nodes[0];
5944 slot = path->slots[0];
5945 if (slot >= btrfs_header_nritems(leaf)) {
5946 ret = btrfs_next_leaf(root, path);
5947 if (ret < 0)
5948 goto err;
5949 else if (ret > 0)
5950 break;
5951 continue;
5952 }
5953
5954 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5955
5956 if (found_key.objectid != key.objectid)
5957 break;
5958 if (found_key.type != BTRFS_DIR_INDEX_KEY)
5959 break;
5960 if (found_key.offset < ctx->pos)
5961 goto next;
5962 if (btrfs_should_delete_dir_index(&del_list, found_key.offset))
5963 goto next;
5964 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5965 if (verify_dir_item(fs_info, leaf, slot, di))
5966 goto next;
5967
5968 name_len = btrfs_dir_name_len(leaf, di);
5969 if ((total_len + sizeof(struct dir_entry) + name_len) >=
5970 PAGE_SIZE) {
5971 btrfs_release_path(path);
5972 ret = btrfs_filldir(private->filldir_buf, entries, ctx);
5973 if (ret)
5974 goto nopos;
5975 addr = private->filldir_buf;
5976 entries = 0;
5977 total_len = 0;
5978 goto again;
5979 }
5980
5981 entry = addr;
5982 entry->name_len = name_len;
5983 name_ptr = (char *)(entry + 1);
5984 read_extent_buffer(leaf, name_ptr, (unsigned long)(di + 1),
5985 name_len);
5986 entry->type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5987 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5988 entry->ino = location.objectid;
5989 entry->offset = found_key.offset;
5990 entries++;
5991 addr += sizeof(struct dir_entry) + name_len;
5992 total_len += sizeof(struct dir_entry) + name_len;
5993next:
5994 path->slots[0]++;
5995 }
5996 btrfs_release_path(path);
5997
5998 ret = btrfs_filldir(private->filldir_buf, entries, ctx);
5999 if (ret)
6000 goto nopos;
6001
6002 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
6003 if (ret)
6004 goto nopos;
6005
6006 /*
6007 * Stop new entries from being returned after we return the last
6008 * entry.
6009 *
6010 * New directory entries are assigned a strictly increasing
6011 * offset. This means that new entries created during readdir
6012 * are *guaranteed* to be seen in the future by that readdir.
6013 * This has broken buggy programs which operate on names as
6014 * they're returned by readdir. Until we re-use freed offsets
6015 * we have this hack to stop new entries from being returned
6016 * under the assumption that they'll never reach this huge
6017 * offset.
6018 *
6019 * This is being careful not to overflow 32bit loff_t unless the
6020 * last entry requires it because doing so has broken 32bit apps
6021 * in the past.
6022 */
6023 if (ctx->pos >= INT_MAX)
6024 ctx->pos = LLONG_MAX;
6025 else
6026 ctx->pos = INT_MAX;
6027nopos:
6028 ret = 0;
6029err:
6030 if (put)
6031 btrfs_readdir_put_delayed_items(inode, &ins_list, &del_list);
6032 btrfs_free_path(path);
6033 return ret;
6034}
6035
6036int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
6037{
6038 struct btrfs_root *root = BTRFS_I(inode)->root;
6039 struct btrfs_trans_handle *trans;
6040 int ret = 0;
6041 bool nolock = false;
6042
6043 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
6044 return 0;
6045
6046 if (btrfs_fs_closing(root->fs_info) &&
6047 btrfs_is_free_space_inode(BTRFS_I(inode)))
6048 nolock = true;
6049
6050 if (wbc->sync_mode == WB_SYNC_ALL) {
6051 if (nolock)
6052 trans = btrfs_join_transaction_nolock(root);
6053 else
6054 trans = btrfs_join_transaction(root);
6055 if (IS_ERR(trans))
6056 return PTR_ERR(trans);
6057 ret = btrfs_commit_transaction(trans);
6058 }
6059 return ret;
6060}
6061
6062/*
6063 * This is somewhat expensive, updating the tree every time the
6064 * inode changes. But, it is most likely to find the inode in cache.
6065 * FIXME, needs more benchmarking...there are no reasons other than performance
6066 * to keep or drop this code.
6067 */
6068static int btrfs_dirty_inode(struct inode *inode)
6069{
6070 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6071 struct btrfs_root *root = BTRFS_I(inode)->root;
6072 struct btrfs_trans_handle *trans;
6073 int ret;
6074
6075 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
6076 return 0;
6077
6078 trans = btrfs_join_transaction(root);
6079 if (IS_ERR(trans))
6080 return PTR_ERR(trans);
6081
6082 ret = btrfs_update_inode(trans, root, inode);
6083 if (ret && ret == -ENOSPC) {
6084 /* whoops, lets try again with the full transaction */
6085 btrfs_end_transaction(trans);
6086 trans = btrfs_start_transaction(root, 1);
6087 if (IS_ERR(trans))
6088 return PTR_ERR(trans);
6089
6090 ret = btrfs_update_inode(trans, root, inode);
6091 }
6092 btrfs_end_transaction(trans);
6093 if (BTRFS_I(inode)->delayed_node)
6094 btrfs_balance_delayed_items(fs_info);
6095
6096 return ret;
6097}
6098
6099/*
6100 * This is a copy of file_update_time. We need this so we can return error on
6101 * ENOSPC for updating the inode in the case of file write and mmap writes.
6102 */
6103static int btrfs_update_time(struct inode *inode, struct timespec *now,
6104 int flags)
6105{
6106 struct btrfs_root *root = BTRFS_I(inode)->root;
6107
6108 if (btrfs_root_readonly(root))
6109 return -EROFS;
6110
6111 if (flags & S_VERSION)
6112 inode_inc_iversion(inode);
6113 if (flags & S_CTIME)
6114 inode->i_ctime = *now;
6115 if (flags & S_MTIME)
6116 inode->i_mtime = *now;
6117 if (flags & S_ATIME)
6118 inode->i_atime = *now;
6119 return btrfs_dirty_inode(inode);
6120}
6121
6122/*
6123 * find the highest existing sequence number in a directory
6124 * and then set the in-memory index_cnt variable to reflect
6125 * free sequence numbers
6126 */
6127static int btrfs_set_inode_index_count(struct btrfs_inode *inode)
6128{
6129 struct btrfs_root *root = inode->root;
6130 struct btrfs_key key, found_key;
6131 struct btrfs_path *path;
6132 struct extent_buffer *leaf;
6133 int ret;
6134
6135 key.objectid = btrfs_ino(inode);
6136 key.type = BTRFS_DIR_INDEX_KEY;
6137 key.offset = (u64)-1;
6138
6139 path = btrfs_alloc_path();
6140 if (!path)
6141 return -ENOMEM;
6142
6143 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6144 if (ret < 0)
6145 goto out;
6146 /* FIXME: we should be able to handle this */
6147 if (ret == 0)
6148 goto out;
6149 ret = 0;
6150
6151 /*
6152 * MAGIC NUMBER EXPLANATION:
6153 * since we search a directory based on f_pos we have to start at 2
6154 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
6155 * else has to start at 2
6156 */
6157 if (path->slots[0] == 0) {
6158 inode->index_cnt = 2;
6159 goto out;
6160 }
6161
6162 path->slots[0]--;
6163
6164 leaf = path->nodes[0];
6165 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6166
6167 if (found_key.objectid != btrfs_ino(inode) ||
6168 found_key.type != BTRFS_DIR_INDEX_KEY) {
6169 inode->index_cnt = 2;
6170 goto out;
6171 }
6172
6173 inode->index_cnt = found_key.offset + 1;
6174out:
6175 btrfs_free_path(path);
6176 return ret;
6177}
6178
6179/*
6180 * helper to find a free sequence number in a given directory. This current
6181 * code is very simple, later versions will do smarter things in the btree
6182 */
6183int btrfs_set_inode_index(struct btrfs_inode *dir, u64 *index)
6184{
6185 int ret = 0;
6186
6187 if (dir->index_cnt == (u64)-1) {
6188 ret = btrfs_inode_delayed_dir_index_count(dir);
6189 if (ret) {
6190 ret = btrfs_set_inode_index_count(dir);
6191 if (ret)
6192 return ret;
6193 }
6194 }
6195
6196 *index = dir->index_cnt;
6197 dir->index_cnt++;
6198
6199 return ret;
6200}
6201
6202static int btrfs_insert_inode_locked(struct inode *inode)
6203{
6204 struct btrfs_iget_args args;
6205 args.location = &BTRFS_I(inode)->location;
6206 args.root = BTRFS_I(inode)->root;
6207
6208 return insert_inode_locked4(inode,
6209 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
6210 btrfs_find_actor, &args);
6211}
6212
6213/*
6214 * Inherit flags from the parent inode.
6215 *
6216 * Currently only the compression flags and the cow flags are inherited.
6217 */
6218static void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
6219{
6220 unsigned int flags;
6221
6222 if (!dir)
6223 return;
6224
6225 flags = BTRFS_I(dir)->flags;
6226
6227 if (flags & BTRFS_INODE_NOCOMPRESS) {
6228 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
6229 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
6230 } else if (flags & BTRFS_INODE_COMPRESS) {
6231 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
6232 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
6233 }
6234
6235 if (flags & BTRFS_INODE_NODATACOW) {
6236 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
6237 if (S_ISREG(inode->i_mode))
6238 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6239 }
6240
6241 btrfs_update_iflags(inode);
6242}
6243
6244static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
6245 struct btrfs_root *root,
6246 struct inode *dir,
6247 const char *name, int name_len,
6248 u64 ref_objectid, u64 objectid,
6249 umode_t mode, u64 *index)
6250{
6251 struct btrfs_fs_info *fs_info = root->fs_info;
6252 struct inode *inode;
6253 struct btrfs_inode_item *inode_item;
6254 struct btrfs_key *location;
6255 struct btrfs_path *path;
6256 struct btrfs_inode_ref *ref;
6257 struct btrfs_key key[2];
6258 u32 sizes[2];
6259 int nitems = name ? 2 : 1;
6260 unsigned long ptr;
6261 int ret;
6262
6263 path = btrfs_alloc_path();
6264 if (!path)
6265 return ERR_PTR(-ENOMEM);
6266
6267 inode = new_inode(fs_info->sb);
6268 if (!inode) {
6269 btrfs_free_path(path);
6270 return ERR_PTR(-ENOMEM);
6271 }
6272
6273 /*
6274 * O_TMPFILE, set link count to 0, so that after this point,
6275 * we fill in an inode item with the correct link count.
6276 */
6277 if (!name)
6278 set_nlink(inode, 0);
6279
6280 /*
6281 * we have to initialize this early, so we can reclaim the inode
6282 * number if we fail afterwards in this function.
6283 */
6284 inode->i_ino = objectid;
6285
6286 if (dir && name) {
6287 trace_btrfs_inode_request(dir);
6288
6289 ret = btrfs_set_inode_index(BTRFS_I(dir), index);
6290 if (ret) {
6291 btrfs_free_path(path);
6292 iput(inode);
6293 return ERR_PTR(ret);
6294 }
6295 } else if (dir) {
6296 *index = 0;
6297 }
6298 /*
6299 * index_cnt is ignored for everything but a dir,
6300 * btrfs_get_inode_index_count has an explanation for the magic
6301 * number
6302 */
6303 BTRFS_I(inode)->index_cnt = 2;
6304 BTRFS_I(inode)->dir_index = *index;
6305 BTRFS_I(inode)->root = root;
6306 BTRFS_I(inode)->generation = trans->transid;
6307 inode->i_generation = BTRFS_I(inode)->generation;
6308
6309 /*
6310 * We could have gotten an inode number from somebody who was fsynced
6311 * and then removed in this same transaction, so let's just set full
6312 * sync since it will be a full sync anyway and this will blow away the
6313 * old info in the log.
6314 */
6315 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6316
6317 key[0].objectid = objectid;
6318 key[0].type = BTRFS_INODE_ITEM_KEY;
6319 key[0].offset = 0;
6320
6321 sizes[0] = sizeof(struct btrfs_inode_item);
6322
6323 if (name) {
6324 /*
6325 * Start new inodes with an inode_ref. This is slightly more
6326 * efficient for small numbers of hard links since they will
6327 * be packed into one item. Extended refs will kick in if we
6328 * add more hard links than can fit in the ref item.
6329 */
6330 key[1].objectid = objectid;
6331 key[1].type = BTRFS_INODE_REF_KEY;
6332 key[1].offset = ref_objectid;
6333
6334 sizes[1] = name_len + sizeof(*ref);
6335 }
6336
6337 location = &BTRFS_I(inode)->location;
6338 location->objectid = objectid;
6339 location->offset = 0;
6340 location->type = BTRFS_INODE_ITEM_KEY;
6341
6342 ret = btrfs_insert_inode_locked(inode);
6343 if (ret < 0)
6344 goto fail;
6345
6346 path->leave_spinning = 1;
6347 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6348 if (ret != 0)
6349 goto fail_unlock;
6350
6351 inode_init_owner(inode, dir, mode);
6352 inode_set_bytes(inode, 0);
6353
6354 inode->i_mtime = current_time(inode);
6355 inode->i_atime = inode->i_mtime;
6356 inode->i_ctime = inode->i_mtime;
6357 BTRFS_I(inode)->i_otime = inode->i_mtime;
6358
6359 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6360 struct btrfs_inode_item);
6361 memzero_extent_buffer(path->nodes[0], (unsigned long)inode_item,
6362 sizeof(*inode_item));
6363 fill_inode_item(trans, path->nodes[0], inode_item, inode);
6364
6365 if (name) {
6366 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6367 struct btrfs_inode_ref);
6368 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6369 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6370 ptr = (unsigned long)(ref + 1);
6371 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6372 }
6373
6374 btrfs_mark_buffer_dirty(path->nodes[0]);
6375 btrfs_free_path(path);
6376
6377 btrfs_inherit_iflags(inode, dir);
6378
6379 if (S_ISREG(mode)) {
6380 if (btrfs_test_opt(fs_info, NODATASUM))
6381 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6382 if (btrfs_test_opt(fs_info, NODATACOW))
6383 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6384 BTRFS_INODE_NODATASUM;
6385 }
6386
6387 inode_tree_add(inode);
6388
6389 trace_btrfs_inode_new(inode);
6390 btrfs_set_inode_last_trans(trans, inode);
6391
6392 btrfs_update_root_times(trans, root);
6393
6394 ret = btrfs_inode_inherit_props(trans, inode, dir);
6395 if (ret)
6396 btrfs_err(fs_info,
6397 "error inheriting props for ino %llu (root %llu): %d",
6398 btrfs_ino(BTRFS_I(inode)), root->root_key.objectid, ret);
6399
6400 return inode;
6401
6402fail_unlock:
6403 unlock_new_inode(inode);
6404fail:
6405 if (dir && name)
6406 BTRFS_I(dir)->index_cnt--;
6407 btrfs_free_path(path);
6408 iput(inode);
6409 return ERR_PTR(ret);
6410}
6411
6412static inline u8 btrfs_inode_type(struct inode *inode)
6413{
6414 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
6415}
6416
6417/*
6418 * utility function to add 'inode' into 'parent_inode' with
6419 * a give name and a given sequence number.
6420 * if 'add_backref' is true, also insert a backref from the
6421 * inode to the parent directory.
6422 */
6423int btrfs_add_link(struct btrfs_trans_handle *trans,
6424 struct btrfs_inode *parent_inode, struct btrfs_inode *inode,
6425 const char *name, int name_len, int add_backref, u64 index)
6426{
6427 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
6428 int ret = 0;
6429 struct btrfs_key key;
6430 struct btrfs_root *root = parent_inode->root;
6431 u64 ino = btrfs_ino(inode);
6432 u64 parent_ino = btrfs_ino(parent_inode);
6433
6434 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6435 memcpy(&key, &inode->root->root_key, sizeof(key));
6436 } else {
6437 key.objectid = ino;
6438 key.type = BTRFS_INODE_ITEM_KEY;
6439 key.offset = 0;
6440 }
6441
6442 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6443 ret = btrfs_add_root_ref(trans, fs_info, key.objectid,
6444 root->root_key.objectid, parent_ino,
6445 index, name, name_len);
6446 } else if (add_backref) {
6447 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6448 parent_ino, index);
6449 }
6450
6451 /* Nothing to clean up yet */
6452 if (ret)
6453 return ret;
6454
6455 ret = btrfs_insert_dir_item(trans, root, name, name_len,
6456 parent_inode, &key,
6457 btrfs_inode_type(&inode->vfs_inode), index);
6458 if (ret == -EEXIST || ret == -EOVERFLOW)
6459 goto fail_dir_item;
6460 else if (ret) {
6461 btrfs_abort_transaction(trans, ret);
6462 return ret;
6463 }
6464
6465 btrfs_i_size_write(parent_inode, parent_inode->vfs_inode.i_size +
6466 name_len * 2);
6467 inode_inc_iversion(&parent_inode->vfs_inode);
6468 parent_inode->vfs_inode.i_mtime = parent_inode->vfs_inode.i_ctime =
6469 current_time(&parent_inode->vfs_inode);
6470 ret = btrfs_update_inode(trans, root, &parent_inode->vfs_inode);
6471 if (ret)
6472 btrfs_abort_transaction(trans, ret);
6473 return ret;
6474
6475fail_dir_item:
6476 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6477 u64 local_index;
6478 int err;
6479 err = btrfs_del_root_ref(trans, fs_info, key.objectid,
6480 root->root_key.objectid, parent_ino,
6481 &local_index, name, name_len);
6482
6483 } else if (add_backref) {
6484 u64 local_index;
6485 int err;
6486
6487 err = btrfs_del_inode_ref(trans, root, name, name_len,
6488 ino, parent_ino, &local_index);
6489 }
6490 return ret;
6491}
6492
6493static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6494 struct btrfs_inode *dir, struct dentry *dentry,
6495 struct btrfs_inode *inode, int backref, u64 index)
6496{
6497 int err = btrfs_add_link(trans, dir, inode,
6498 dentry->d_name.name, dentry->d_name.len,
6499 backref, index);
6500 if (err > 0)
6501 err = -EEXIST;
6502 return err;
6503}
6504
6505static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6506 umode_t mode, dev_t rdev)
6507{
6508 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6509 struct btrfs_trans_handle *trans;
6510 struct btrfs_root *root = BTRFS_I(dir)->root;
6511 struct inode *inode = NULL;
6512 int err;
6513 int drop_inode = 0;
6514 u64 objectid;
6515 u64 index = 0;
6516
6517 /*
6518 * 2 for inode item and ref
6519 * 2 for dir items
6520 * 1 for xattr if selinux is on
6521 */
6522 trans = btrfs_start_transaction(root, 5);
6523 if (IS_ERR(trans))
6524 return PTR_ERR(trans);
6525
6526 err = btrfs_find_free_ino(root, &objectid);
6527 if (err)
6528 goto out_unlock;
6529
6530 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6531 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6532 mode, &index);
6533 if (IS_ERR(inode)) {
6534 err = PTR_ERR(inode);
6535 goto out_unlock;
6536 }
6537
6538 /*
6539 * If the active LSM wants to access the inode during
6540 * d_instantiate it needs these. Smack checks to see
6541 * if the filesystem supports xattrs by looking at the
6542 * ops vector.
6543 */
6544 inode->i_op = &btrfs_special_inode_operations;
6545 init_special_inode(inode, inode->i_mode, rdev);
6546
6547 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6548 if (err)
6549 goto out_unlock_inode;
6550
6551 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6552 0, index);
6553 if (err) {
6554 goto out_unlock_inode;
6555 } else {
6556 btrfs_update_inode(trans, root, inode);
6557 unlock_new_inode(inode);
6558 d_instantiate(dentry, inode);
6559 }
6560
6561out_unlock:
6562 btrfs_end_transaction(trans);
6563 btrfs_balance_delayed_items(fs_info);
6564 btrfs_btree_balance_dirty(fs_info);
6565 if (drop_inode) {
6566 inode_dec_link_count(inode);
6567 iput(inode);
6568 }
6569 return err;
6570
6571out_unlock_inode:
6572 drop_inode = 1;
6573 unlock_new_inode(inode);
6574 goto out_unlock;
6575
6576}
6577
6578static int btrfs_create(struct inode *dir, struct dentry *dentry,
6579 umode_t mode, bool excl)
6580{
6581 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6582 struct btrfs_trans_handle *trans;
6583 struct btrfs_root *root = BTRFS_I(dir)->root;
6584 struct inode *inode = NULL;
6585 int drop_inode_on_err = 0;
6586 int err;
6587 u64 objectid;
6588 u64 index = 0;
6589
6590 /*
6591 * 2 for inode item and ref
6592 * 2 for dir items
6593 * 1 for xattr if selinux is on
6594 */
6595 trans = btrfs_start_transaction(root, 5);
6596 if (IS_ERR(trans))
6597 return PTR_ERR(trans);
6598
6599 err = btrfs_find_free_ino(root, &objectid);
6600 if (err)
6601 goto out_unlock;
6602
6603 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6604 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6605 mode, &index);
6606 if (IS_ERR(inode)) {
6607 err = PTR_ERR(inode);
6608 goto out_unlock;
6609 }
6610 drop_inode_on_err = 1;
6611 /*
6612 * If the active LSM wants to access the inode during
6613 * d_instantiate it needs these. Smack checks to see
6614 * if the filesystem supports xattrs by looking at the
6615 * ops vector.
6616 */
6617 inode->i_fop = &btrfs_file_operations;
6618 inode->i_op = &btrfs_file_inode_operations;
6619 inode->i_mapping->a_ops = &btrfs_aops;
6620
6621 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6622 if (err)
6623 goto out_unlock_inode;
6624
6625 err = btrfs_update_inode(trans, root, inode);
6626 if (err)
6627 goto out_unlock_inode;
6628
6629 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6630 0, index);
6631 if (err)
6632 goto out_unlock_inode;
6633
6634 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6635 unlock_new_inode(inode);
6636 d_instantiate(dentry, inode);
6637
6638out_unlock:
6639 btrfs_end_transaction(trans);
6640 if (err && drop_inode_on_err) {
6641 inode_dec_link_count(inode);
6642 iput(inode);
6643 }
6644 btrfs_balance_delayed_items(fs_info);
6645 btrfs_btree_balance_dirty(fs_info);
6646 return err;
6647
6648out_unlock_inode:
6649 unlock_new_inode(inode);
6650 goto out_unlock;
6651
6652}
6653
6654static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6655 struct dentry *dentry)
6656{
6657 struct btrfs_trans_handle *trans = NULL;
6658 struct btrfs_root *root = BTRFS_I(dir)->root;
6659 struct inode *inode = d_inode(old_dentry);
6660 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6661 u64 index;
6662 int err;
6663 int drop_inode = 0;
6664
6665 /* do not allow sys_link's with other subvols of the same device */
6666 if (root->objectid != BTRFS_I(inode)->root->objectid)
6667 return -EXDEV;
6668
6669 if (inode->i_nlink >= BTRFS_LINK_MAX)
6670 return -EMLINK;
6671
6672 err = btrfs_set_inode_index(BTRFS_I(dir), &index);
6673 if (err)
6674 goto fail;
6675
6676 /*
6677 * 2 items for inode and inode ref
6678 * 2 items for dir items
6679 * 1 item for parent inode
6680 */
6681 trans = btrfs_start_transaction(root, 5);
6682 if (IS_ERR(trans)) {
6683 err = PTR_ERR(trans);
6684 trans = NULL;
6685 goto fail;
6686 }
6687
6688 /* There are several dir indexes for this inode, clear the cache. */
6689 BTRFS_I(inode)->dir_index = 0ULL;
6690 inc_nlink(inode);
6691 inode_inc_iversion(inode);
6692 inode->i_ctime = current_time(inode);
6693 ihold(inode);
6694 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6695
6696 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6697 1, index);
6698
6699 if (err) {
6700 drop_inode = 1;
6701 } else {
6702 struct dentry *parent = dentry->d_parent;
6703 err = btrfs_update_inode(trans, root, inode);
6704 if (err)
6705 goto fail;
6706 if (inode->i_nlink == 1) {
6707 /*
6708 * If new hard link count is 1, it's a file created
6709 * with open(2) O_TMPFILE flag.
6710 */
6711 err = btrfs_orphan_del(trans, BTRFS_I(inode));
6712 if (err)
6713 goto fail;
6714 }
6715 d_instantiate(dentry, inode);
6716 btrfs_log_new_name(trans, BTRFS_I(inode), NULL, parent);
6717 }
6718
6719 btrfs_balance_delayed_items(fs_info);
6720fail:
6721 if (trans)
6722 btrfs_end_transaction(trans);
6723 if (drop_inode) {
6724 inode_dec_link_count(inode);
6725 iput(inode);
6726 }
6727 btrfs_btree_balance_dirty(fs_info);
6728 return err;
6729}
6730
6731static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6732{
6733 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6734 struct inode *inode = NULL;
6735 struct btrfs_trans_handle *trans;
6736 struct btrfs_root *root = BTRFS_I(dir)->root;
6737 int err = 0;
6738 int drop_on_err = 0;
6739 u64 objectid = 0;
6740 u64 index = 0;
6741
6742 /*
6743 * 2 items for inode and ref
6744 * 2 items for dir items
6745 * 1 for xattr if selinux is on
6746 */
6747 trans = btrfs_start_transaction(root, 5);
6748 if (IS_ERR(trans))
6749 return PTR_ERR(trans);
6750
6751 err = btrfs_find_free_ino(root, &objectid);
6752 if (err)
6753 goto out_fail;
6754
6755 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6756 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6757 S_IFDIR | mode, &index);
6758 if (IS_ERR(inode)) {
6759 err = PTR_ERR(inode);
6760 goto out_fail;
6761 }
6762
6763 drop_on_err = 1;
6764 /* these must be set before we unlock the inode */
6765 inode->i_op = &btrfs_dir_inode_operations;
6766 inode->i_fop = &btrfs_dir_file_operations;
6767
6768 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6769 if (err)
6770 goto out_fail_inode;
6771
6772 btrfs_i_size_write(BTRFS_I(inode), 0);
6773 err = btrfs_update_inode(trans, root, inode);
6774 if (err)
6775 goto out_fail_inode;
6776
6777 err = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
6778 dentry->d_name.name,
6779 dentry->d_name.len, 0, index);
6780 if (err)
6781 goto out_fail_inode;
6782
6783 d_instantiate(dentry, inode);
6784 /*
6785 * mkdir is special. We're unlocking after we call d_instantiate
6786 * to avoid a race with nfsd calling d_instantiate.
6787 */
6788 unlock_new_inode(inode);
6789 drop_on_err = 0;
6790
6791out_fail:
6792 btrfs_end_transaction(trans);
6793 if (drop_on_err) {
6794 inode_dec_link_count(inode);
6795 iput(inode);
6796 }
6797 btrfs_balance_delayed_items(fs_info);
6798 btrfs_btree_balance_dirty(fs_info);
6799 return err;
6800
6801out_fail_inode:
6802 unlock_new_inode(inode);
6803 goto out_fail;
6804}
6805
6806/* Find next extent map of a given extent map, caller needs to ensure locks */
6807static struct extent_map *next_extent_map(struct extent_map *em)
6808{
6809 struct rb_node *next;
6810
6811 next = rb_next(&em->rb_node);
6812 if (!next)
6813 return NULL;
6814 return container_of(next, struct extent_map, rb_node);
6815}
6816
6817static struct extent_map *prev_extent_map(struct extent_map *em)
6818{
6819 struct rb_node *prev;
6820
6821 prev = rb_prev(&em->rb_node);
6822 if (!prev)
6823 return NULL;
6824 return container_of(prev, struct extent_map, rb_node);
6825}
6826
6827/* helper for btfs_get_extent. Given an existing extent in the tree,
6828 * the existing extent is the nearest extent to map_start,
6829 * and an extent that you want to insert, deal with overlap and insert
6830 * the best fitted new extent into the tree.
6831 */
6832static int merge_extent_mapping(struct extent_map_tree *em_tree,
6833 struct extent_map *existing,
6834 struct extent_map *em,
6835 u64 map_start)
6836{
6837 struct extent_map *prev;
6838 struct extent_map *next;
6839 u64 start;
6840 u64 end;
6841 u64 start_diff;
6842
6843 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
6844
6845 if (existing->start > map_start) {
6846 next = existing;
6847 prev = prev_extent_map(next);
6848 } else {
6849 prev = existing;
6850 next = next_extent_map(prev);
6851 }
6852
6853 start = prev ? extent_map_end(prev) : em->start;
6854 start = max_t(u64, start, em->start);
6855 end = next ? next->start : extent_map_end(em);
6856 end = min_t(u64, end, extent_map_end(em));
6857 start_diff = start - em->start;
6858 em->start = start;
6859 em->len = end - start;
6860 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
6861 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
6862 em->block_start += start_diff;
6863 em->block_len -= start_diff;
6864 }
6865 return add_extent_mapping(em_tree, em, 0);
6866}
6867
6868static noinline int uncompress_inline(struct btrfs_path *path,
6869 struct page *page,
6870 size_t pg_offset, u64 extent_offset,
6871 struct btrfs_file_extent_item *item)
6872{
6873 int ret;
6874 struct extent_buffer *leaf = path->nodes[0];
6875 char *tmp;
6876 size_t max_size;
6877 unsigned long inline_size;
6878 unsigned long ptr;
6879 int compress_type;
6880
6881 WARN_ON(pg_offset != 0);
6882 compress_type = btrfs_file_extent_compression(leaf, item);
6883 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6884 inline_size = btrfs_file_extent_inline_item_len(leaf,
6885 btrfs_item_nr(path->slots[0]));
6886 tmp = kmalloc(inline_size, GFP_NOFS);
6887 if (!tmp)
6888 return -ENOMEM;
6889 ptr = btrfs_file_extent_inline_start(item);
6890
6891 read_extent_buffer(leaf, tmp, ptr, inline_size);
6892
6893 max_size = min_t(unsigned long, PAGE_SIZE, max_size);
6894 ret = btrfs_decompress(compress_type, tmp, page,
6895 extent_offset, inline_size, max_size);
6896
6897 /*
6898 * decompression code contains a memset to fill in any space between the end
6899 * of the uncompressed data and the end of max_size in case the decompressed
6900 * data ends up shorter than ram_bytes. That doesn't cover the hole between
6901 * the end of an inline extent and the beginning of the next block, so we
6902 * cover that region here.
6903 */
6904
6905 if (max_size + pg_offset < PAGE_SIZE) {
6906 char *map = kmap(page);
6907 memset(map + pg_offset + max_size, 0, PAGE_SIZE - max_size - pg_offset);
6908 kunmap(page);
6909 }
6910 kfree(tmp);
6911 return ret;
6912}
6913
6914/*
6915 * a bit scary, this does extent mapping from logical file offset to the disk.
6916 * the ugly parts come from merging extents from the disk with the in-ram
6917 * representation. This gets more complex because of the data=ordered code,
6918 * where the in-ram extents might be locked pending data=ordered completion.
6919 *
6920 * This also copies inline extents directly into the page.
6921 */
6922struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
6923 struct page *page,
6924 size_t pg_offset, u64 start, u64 len,
6925 int create)
6926{
6927 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
6928 int ret;
6929 int err = 0;
6930 u64 extent_start = 0;
6931 u64 extent_end = 0;
6932 u64 objectid = btrfs_ino(inode);
6933 u32 found_type;
6934 struct btrfs_path *path = NULL;
6935 struct btrfs_root *root = inode->root;
6936 struct btrfs_file_extent_item *item;
6937 struct extent_buffer *leaf;
6938 struct btrfs_key found_key;
6939 struct extent_map *em = NULL;
6940 struct extent_map_tree *em_tree = &inode->extent_tree;
6941 struct extent_io_tree *io_tree = &inode->io_tree;
6942 struct btrfs_trans_handle *trans = NULL;
6943 const bool new_inline = !page || create;
6944
6945again:
6946 read_lock(&em_tree->lock);
6947 em = lookup_extent_mapping(em_tree, start, len);
6948 if (em)
6949 em->bdev = fs_info->fs_devices->latest_bdev;
6950 read_unlock(&em_tree->lock);
6951
6952 if (em) {
6953 if (em->start > start || em->start + em->len <= start)
6954 free_extent_map(em);
6955 else if (em->block_start == EXTENT_MAP_INLINE && page)
6956 free_extent_map(em);
6957 else
6958 goto out;
6959 }
6960 em = alloc_extent_map();
6961 if (!em) {
6962 err = -ENOMEM;
6963 goto out;
6964 }
6965 em->bdev = fs_info->fs_devices->latest_bdev;
6966 em->start = EXTENT_MAP_HOLE;
6967 em->orig_start = EXTENT_MAP_HOLE;
6968 em->len = (u64)-1;
6969 em->block_len = (u64)-1;
6970
6971 if (!path) {
6972 path = btrfs_alloc_path();
6973 if (!path) {
6974 err = -ENOMEM;
6975 goto out;
6976 }
6977 /*
6978 * Chances are we'll be called again, so go ahead and do
6979 * readahead
6980 */
6981 path->reada = READA_FORWARD;
6982 }
6983
6984 ret = btrfs_lookup_file_extent(trans, root, path,
6985 objectid, start, trans != NULL);
6986 if (ret < 0) {
6987 err = ret;
6988 goto out;
6989 }
6990
6991 if (ret != 0) {
6992 if (path->slots[0] == 0)
6993 goto not_found;
6994 path->slots[0]--;
6995 }
6996
6997 leaf = path->nodes[0];
6998 item = btrfs_item_ptr(leaf, path->slots[0],
6999 struct btrfs_file_extent_item);
7000 /* are we inside the extent that was found? */
7001 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
7002 found_type = found_key.type;
7003 if (found_key.objectid != objectid ||
7004 found_type != BTRFS_EXTENT_DATA_KEY) {
7005 /*
7006 * If we backup past the first extent we want to move forward
7007 * and see if there is an extent in front of us, otherwise we'll
7008 * say there is a hole for our whole search range which can
7009 * cause problems.
7010 */
7011 extent_end = start;
7012 goto next;
7013 }
7014
7015 found_type = btrfs_file_extent_type(leaf, item);
7016 extent_start = found_key.offset;
7017 if (found_type == BTRFS_FILE_EXTENT_REG ||
7018 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7019 extent_end = extent_start +
7020 btrfs_file_extent_num_bytes(leaf, item);
7021
7022 trace_btrfs_get_extent_show_fi_regular(inode, leaf, item,
7023 extent_start);
7024 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
7025 size_t size;
7026 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
7027 extent_end = ALIGN(extent_start + size,
7028 fs_info->sectorsize);
7029
7030 trace_btrfs_get_extent_show_fi_inline(inode, leaf, item,
7031 path->slots[0],
7032 extent_start);
7033 }
7034next:
7035 if (start >= extent_end) {
7036 path->slots[0]++;
7037 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
7038 ret = btrfs_next_leaf(root, path);
7039 if (ret < 0) {
7040 err = ret;
7041 goto out;
7042 }
7043 if (ret > 0)
7044 goto not_found;
7045 leaf = path->nodes[0];
7046 }
7047 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
7048 if (found_key.objectid != objectid ||
7049 found_key.type != BTRFS_EXTENT_DATA_KEY)
7050 goto not_found;
7051 if (start + len <= found_key.offset)
7052 goto not_found;
7053 if (start > found_key.offset)
7054 goto next;
7055 em->start = start;
7056 em->orig_start = start;
7057 em->len = found_key.offset - start;
7058 goto not_found_em;
7059 }
7060
7061 btrfs_extent_item_to_extent_map(inode, path, item,
7062 new_inline, em);
7063
7064 if (found_type == BTRFS_FILE_EXTENT_REG ||
7065 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7066 goto insert;
7067 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
7068 unsigned long ptr;
7069 char *map;
7070 size_t size;
7071 size_t extent_offset;
7072 size_t copy_size;
7073
7074 if (new_inline)
7075 goto out;
7076
7077 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
7078 extent_offset = page_offset(page) + pg_offset - extent_start;
7079 copy_size = min_t(u64, PAGE_SIZE - pg_offset,
7080 size - extent_offset);
7081 em->start = extent_start + extent_offset;
7082 em->len = ALIGN(copy_size, fs_info->sectorsize);
7083 em->orig_block_len = em->len;
7084 em->orig_start = em->start;
7085 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
7086 if (create == 0 && !PageUptodate(page)) {
7087 if (btrfs_file_extent_compression(leaf, item) !=
7088 BTRFS_COMPRESS_NONE) {
7089 ret = uncompress_inline(path, page, pg_offset,
7090 extent_offset, item);
7091 if (ret) {
7092 err = ret;
7093 goto out;
7094 }
7095 } else {
7096 map = kmap(page);
7097 read_extent_buffer(leaf, map + pg_offset, ptr,
7098 copy_size);
7099 if (pg_offset + copy_size < PAGE_SIZE) {
7100 memset(map + pg_offset + copy_size, 0,
7101 PAGE_SIZE - pg_offset -
7102 copy_size);
7103 }
7104 kunmap(page);
7105 }
7106 flush_dcache_page(page);
7107 } else if (create && PageUptodate(page)) {
7108 BUG();
7109 if (!trans) {
7110 kunmap(page);
7111 free_extent_map(em);
7112 em = NULL;
7113
7114 btrfs_release_path(path);
7115 trans = btrfs_join_transaction(root);
7116
7117 if (IS_ERR(trans))
7118 return ERR_CAST(trans);
7119 goto again;
7120 }
7121 map = kmap(page);
7122 write_extent_buffer(leaf, map + pg_offset, ptr,
7123 copy_size);
7124 kunmap(page);
7125 btrfs_mark_buffer_dirty(leaf);
7126 }
7127 set_extent_uptodate(io_tree, em->start,
7128 extent_map_end(em) - 1, NULL, GFP_NOFS);
7129 goto insert;
7130 }
7131not_found:
7132 em->start = start;
7133 em->orig_start = start;
7134 em->len = len;
7135not_found_em:
7136 em->block_start = EXTENT_MAP_HOLE;
7137 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
7138insert:
7139 btrfs_release_path(path);
7140 if (em->start > start || extent_map_end(em) <= start) {
7141 btrfs_err(fs_info,
7142 "bad extent! em: [%llu %llu] passed [%llu %llu]",
7143 em->start, em->len, start, len);
7144 err = -EIO;
7145 goto out;
7146 }
7147
7148 err = 0;
7149 write_lock(&em_tree->lock);
7150 ret = add_extent_mapping(em_tree, em, 0);
7151 /* it is possible that someone inserted the extent into the tree
7152 * while we had the lock dropped. It is also possible that
7153 * an overlapping map exists in the tree
7154 */
7155 if (ret == -EEXIST) {
7156 struct extent_map *existing;
7157
7158 ret = 0;
7159
7160 existing = search_extent_mapping(em_tree, start, len);
7161 /*
7162 * existing will always be non-NULL, since there must be
7163 * extent causing the -EEXIST.
7164 */
7165 if (existing->start == em->start &&
7166 extent_map_end(existing) >= extent_map_end(em) &&
7167 em->block_start == existing->block_start) {
7168 /*
7169 * The existing extent map already encompasses the
7170 * entire extent map we tried to add.
7171 */
7172 free_extent_map(em);
7173 em = existing;
7174 err = 0;
7175
7176 } else if (start >= extent_map_end(existing) ||
7177 start <= existing->start) {
7178 /*
7179 * The existing extent map is the one nearest to
7180 * the [start, start + len) range which overlaps
7181 */
7182 err = merge_extent_mapping(em_tree, existing,
7183 em, start);
7184 free_extent_map(existing);
7185 if (err) {
7186 free_extent_map(em);
7187 em = NULL;
7188 }
7189 } else {
7190 free_extent_map(em);
7191 em = existing;
7192 err = 0;
7193 }
7194 }
7195 write_unlock(&em_tree->lock);
7196out:
7197
7198 trace_btrfs_get_extent(root, inode, em);
7199
7200 btrfs_free_path(path);
7201 if (trans) {
7202 ret = btrfs_end_transaction(trans);
7203 if (!err)
7204 err = ret;
7205 }
7206 if (err) {
7207 free_extent_map(em);
7208 return ERR_PTR(err);
7209 }
7210 BUG_ON(!em); /* Error is always set */
7211 return em;
7212}
7213
7214struct extent_map *btrfs_get_extent_fiemap(struct btrfs_inode *inode,
7215 struct page *page,
7216 size_t pg_offset, u64 start, u64 len,
7217 int create)
7218{
7219 struct extent_map *em;
7220 struct extent_map *hole_em = NULL;
7221 u64 range_start = start;
7222 u64 end;
7223 u64 found;
7224 u64 found_end;
7225 int err = 0;
7226
7227 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
7228 if (IS_ERR(em))
7229 return em;
7230 /*
7231 * If our em maps to:
7232 * - a hole or
7233 * - a pre-alloc extent,
7234 * there might actually be delalloc bytes behind it.
7235 */
7236 if (em->block_start != EXTENT_MAP_HOLE &&
7237 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7238 return em;
7239 else
7240 hole_em = em;
7241
7242 /* check to see if we've wrapped (len == -1 or similar) */
7243 end = start + len;
7244 if (end < start)
7245 end = (u64)-1;
7246 else
7247 end -= 1;
7248
7249 em = NULL;
7250
7251 /* ok, we didn't find anything, lets look for delalloc */
7252 found = count_range_bits(&inode->io_tree, &range_start,
7253 end, len, EXTENT_DELALLOC, 1);
7254 found_end = range_start + found;
7255 if (found_end < range_start)
7256 found_end = (u64)-1;
7257
7258 /*
7259 * we didn't find anything useful, return
7260 * the original results from get_extent()
7261 */
7262 if (range_start > end || found_end <= start) {
7263 em = hole_em;
7264 hole_em = NULL;
7265 goto out;
7266 }
7267
7268 /* adjust the range_start to make sure it doesn't
7269 * go backwards from the start they passed in
7270 */
7271 range_start = max(start, range_start);
7272 found = found_end - range_start;
7273
7274 if (found > 0) {
7275 u64 hole_start = start;
7276 u64 hole_len = len;
7277
7278 em = alloc_extent_map();
7279 if (!em) {
7280 err = -ENOMEM;
7281 goto out;
7282 }
7283 /*
7284 * when btrfs_get_extent can't find anything it
7285 * returns one huge hole
7286 *
7287 * make sure what it found really fits our range, and
7288 * adjust to make sure it is based on the start from
7289 * the caller
7290 */
7291 if (hole_em) {
7292 u64 calc_end = extent_map_end(hole_em);
7293
7294 if (calc_end <= start || (hole_em->start > end)) {
7295 free_extent_map(hole_em);
7296 hole_em = NULL;
7297 } else {
7298 hole_start = max(hole_em->start, start);
7299 hole_len = calc_end - hole_start;
7300 }
7301 }
7302 em->bdev = NULL;
7303 if (hole_em && range_start > hole_start) {
7304 /* our hole starts before our delalloc, so we
7305 * have to return just the parts of the hole
7306 * that go until the delalloc starts
7307 */
7308 em->len = min(hole_len,
7309 range_start - hole_start);
7310 em->start = hole_start;
7311 em->orig_start = hole_start;
7312 /*
7313 * don't adjust block start at all,
7314 * it is fixed at EXTENT_MAP_HOLE
7315 */
7316 em->block_start = hole_em->block_start;
7317 em->block_len = hole_len;
7318 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
7319 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7320 } else {
7321 em->start = range_start;
7322 em->len = found;
7323 em->orig_start = range_start;
7324 em->block_start = EXTENT_MAP_DELALLOC;
7325 em->block_len = found;
7326 }
7327 } else if (hole_em) {
7328 return hole_em;
7329 }
7330out:
7331
7332 free_extent_map(hole_em);
7333 if (err) {
7334 free_extent_map(em);
7335 return ERR_PTR(err);
7336 }
7337 return em;
7338}
7339
7340static struct extent_map *btrfs_create_dio_extent(struct inode *inode,
7341 const u64 start,
7342 const u64 len,
7343 const u64 orig_start,
7344 const u64 block_start,
7345 const u64 block_len,
7346 const u64 orig_block_len,
7347 const u64 ram_bytes,
7348 const int type)
7349{
7350 struct extent_map *em = NULL;
7351 int ret;
7352
7353 if (type != BTRFS_ORDERED_NOCOW) {
7354 em = create_io_em(inode, start, len, orig_start,
7355 block_start, block_len, orig_block_len,
7356 ram_bytes,
7357 BTRFS_COMPRESS_NONE, /* compress_type */
7358 type);
7359 if (IS_ERR(em))
7360 goto out;
7361 }
7362 ret = btrfs_add_ordered_extent_dio(inode, start, block_start,
7363 len, block_len, type);
7364 if (ret) {
7365 if (em) {
7366 free_extent_map(em);
7367 btrfs_drop_extent_cache(BTRFS_I(inode), start,
7368 start + len - 1, 0);
7369 }
7370 em = ERR_PTR(ret);
7371 }
7372 out:
7373
7374 return em;
7375}
7376
7377static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7378 u64 start, u64 len)
7379{
7380 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7381 struct btrfs_root *root = BTRFS_I(inode)->root;
7382 struct extent_map *em;
7383 struct btrfs_key ins;
7384 u64 alloc_hint;
7385 int ret;
7386
7387 alloc_hint = get_extent_allocation_hint(inode, start, len);
7388 ret = btrfs_reserve_extent(root, len, len, fs_info->sectorsize,
7389 0, alloc_hint, &ins, 1, 1);
7390 if (ret)
7391 return ERR_PTR(ret);
7392
7393 em = btrfs_create_dio_extent(inode, start, ins.offset, start,
7394 ins.objectid, ins.offset, ins.offset,
7395 ins.offset, BTRFS_ORDERED_REGULAR);
7396 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
7397 if (IS_ERR(em))
7398 btrfs_free_reserved_extent(fs_info, ins.objectid,
7399 ins.offset, 1);
7400
7401 return em;
7402}
7403
7404/*
7405 * returns 1 when the nocow is safe, < 1 on error, 0 if the
7406 * block must be cow'd
7407 */
7408noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7409 u64 *orig_start, u64 *orig_block_len,
7410 u64 *ram_bytes)
7411{
7412 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7413 struct btrfs_path *path;
7414 int ret;
7415 struct extent_buffer *leaf;
7416 struct btrfs_root *root = BTRFS_I(inode)->root;
7417 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7418 struct btrfs_file_extent_item *fi;
7419 struct btrfs_key key;
7420 u64 disk_bytenr;
7421 u64 backref_offset;
7422 u64 extent_end;
7423 u64 num_bytes;
7424 int slot;
7425 int found_type;
7426 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7427
7428 path = btrfs_alloc_path();
7429 if (!path)
7430 return -ENOMEM;
7431
7432 ret = btrfs_lookup_file_extent(NULL, root, path,
7433 btrfs_ino(BTRFS_I(inode)), offset, 0);
7434 if (ret < 0)
7435 goto out;
7436
7437 slot = path->slots[0];
7438 if (ret == 1) {
7439 if (slot == 0) {
7440 /* can't find the item, must cow */
7441 ret = 0;
7442 goto out;
7443 }
7444 slot--;
7445 }
7446 ret = 0;
7447 leaf = path->nodes[0];
7448 btrfs_item_key_to_cpu(leaf, &key, slot);
7449 if (key.objectid != btrfs_ino(BTRFS_I(inode)) ||
7450 key.type != BTRFS_EXTENT_DATA_KEY) {
7451 /* not our file or wrong item type, must cow */
7452 goto out;
7453 }
7454
7455 if (key.offset > offset) {
7456 /* Wrong offset, must cow */
7457 goto out;
7458 }
7459
7460 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7461 found_type = btrfs_file_extent_type(leaf, fi);
7462 if (found_type != BTRFS_FILE_EXTENT_REG &&
7463 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7464 /* not a regular extent, must cow */
7465 goto out;
7466 }
7467
7468 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7469 goto out;
7470
7471 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7472 if (extent_end <= offset)
7473 goto out;
7474
7475 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7476 if (disk_bytenr == 0)
7477 goto out;
7478
7479 if (btrfs_file_extent_compression(leaf, fi) ||
7480 btrfs_file_extent_encryption(leaf, fi) ||
7481 btrfs_file_extent_other_encoding(leaf, fi))
7482 goto out;
7483
7484 backref_offset = btrfs_file_extent_offset(leaf, fi);
7485
7486 if (orig_start) {
7487 *orig_start = key.offset - backref_offset;
7488 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7489 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7490 }
7491
7492 if (btrfs_extent_readonly(fs_info, disk_bytenr))
7493 goto out;
7494
7495 num_bytes = min(offset + *len, extent_end) - offset;
7496 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7497 u64 range_end;
7498
7499 range_end = round_up(offset + num_bytes,
7500 root->fs_info->sectorsize) - 1;
7501 ret = test_range_bit(io_tree, offset, range_end,
7502 EXTENT_DELALLOC, 0, NULL);
7503 if (ret) {
7504 ret = -EAGAIN;
7505 goto out;
7506 }
7507 }
7508
7509 btrfs_release_path(path);
7510
7511 /*
7512 * look for other files referencing this extent, if we
7513 * find any we must cow
7514 */
7515
7516 ret = btrfs_cross_ref_exist(root, btrfs_ino(BTRFS_I(inode)),
7517 key.offset - backref_offset, disk_bytenr);
7518 if (ret) {
7519 ret = 0;
7520 goto out;
7521 }
7522
7523 /*
7524 * adjust disk_bytenr and num_bytes to cover just the bytes
7525 * in this extent we are about to write. If there
7526 * are any csums in that range we have to cow in order
7527 * to keep the csums correct
7528 */
7529 disk_bytenr += backref_offset;
7530 disk_bytenr += offset - key.offset;
7531 if (csum_exist_in_range(fs_info, disk_bytenr, num_bytes))
7532 goto out;
7533 /*
7534 * all of the above have passed, it is safe to overwrite this extent
7535 * without cow
7536 */
7537 *len = num_bytes;
7538 ret = 1;
7539out:
7540 btrfs_free_path(path);
7541 return ret;
7542}
7543
7544bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
7545{
7546 struct radix_tree_root *root = &inode->i_mapping->page_tree;
7547 bool found = false;
7548 void **pagep = NULL;
7549 struct page *page = NULL;
7550 unsigned long start_idx;
7551 unsigned long end_idx;
7552
7553 start_idx = start >> PAGE_SHIFT;
7554
7555 /*
7556 * end is the last byte in the last page. end == start is legal
7557 */
7558 end_idx = end >> PAGE_SHIFT;
7559
7560 rcu_read_lock();
7561
7562 /* Most of the code in this while loop is lifted from
7563 * find_get_page. It's been modified to begin searching from a
7564 * page and return just the first page found in that range. If the
7565 * found idx is less than or equal to the end idx then we know that
7566 * a page exists. If no pages are found or if those pages are
7567 * outside of the range then we're fine (yay!) */
7568 while (page == NULL &&
7569 radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
7570 page = radix_tree_deref_slot(pagep);
7571 if (unlikely(!page))
7572 break;
7573
7574 if (radix_tree_exception(page)) {
7575 if (radix_tree_deref_retry(page)) {
7576 page = NULL;
7577 continue;
7578 }
7579 /*
7580 * Otherwise, shmem/tmpfs must be storing a swap entry
7581 * here as an exceptional entry: so return it without
7582 * attempting to raise page count.
7583 */
7584 page = NULL;
7585 break; /* TODO: Is this relevant for this use case? */
7586 }
7587
7588 if (!page_cache_get_speculative(page)) {
7589 page = NULL;
7590 continue;
7591 }
7592
7593 /*
7594 * Has the page moved?
7595 * This is part of the lockless pagecache protocol. See
7596 * include/linux/pagemap.h for details.
7597 */
7598 if (unlikely(page != *pagep)) {
7599 put_page(page);
7600 page = NULL;
7601 }
7602 }
7603
7604 if (page) {
7605 if (page->index <= end_idx)
7606 found = true;
7607 put_page(page);
7608 }
7609
7610 rcu_read_unlock();
7611 return found;
7612}
7613
7614static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7615 struct extent_state **cached_state, int writing)
7616{
7617 struct btrfs_ordered_extent *ordered;
7618 int ret = 0;
7619
7620 while (1) {
7621 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7622 cached_state);
7623 /*
7624 * We're concerned with the entire range that we're going to be
7625 * doing DIO to, so we need to make sure there's no ordered
7626 * extents in this range.
7627 */
7628 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), lockstart,
7629 lockend - lockstart + 1);
7630
7631 /*
7632 * We need to make sure there are no buffered pages in this
7633 * range either, we could have raced between the invalidate in
7634 * generic_file_direct_write and locking the extent. The
7635 * invalidate needs to happen so that reads after a write do not
7636 * get stale data.
7637 */
7638 if (!ordered &&
7639 (!writing ||
7640 !btrfs_page_exists_in_range(inode, lockstart, lockend)))
7641 break;
7642
7643 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7644 cached_state, GFP_NOFS);
7645
7646 if (ordered) {
7647 /*
7648 * If we are doing a DIO read and the ordered extent we
7649 * found is for a buffered write, we can not wait for it
7650 * to complete and retry, because if we do so we can
7651 * deadlock with concurrent buffered writes on page
7652 * locks. This happens only if our DIO read covers more
7653 * than one extent map, if at this point has already
7654 * created an ordered extent for a previous extent map
7655 * and locked its range in the inode's io tree, and a
7656 * concurrent write against that previous extent map's
7657 * range and this range started (we unlock the ranges
7658 * in the io tree only when the bios complete and
7659 * buffered writes always lock pages before attempting
7660 * to lock range in the io tree).
7661 */
7662 if (writing ||
7663 test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags))
7664 btrfs_start_ordered_extent(inode, ordered, 1);
7665 else
7666 ret = -ENOTBLK;
7667 btrfs_put_ordered_extent(ordered);
7668 } else {
7669 /*
7670 * We could trigger writeback for this range (and wait
7671 * for it to complete) and then invalidate the pages for
7672 * this range (through invalidate_inode_pages2_range()),
7673 * but that can lead us to a deadlock with a concurrent
7674 * call to readpages() (a buffered read or a defrag call
7675 * triggered a readahead) on a page lock due to an
7676 * ordered dio extent we created before but did not have
7677 * yet a corresponding bio submitted (whence it can not
7678 * complete), which makes readpages() wait for that
7679 * ordered extent to complete while holding a lock on
7680 * that page.
7681 */
7682 ret = -ENOTBLK;
7683 }
7684
7685 if (ret)
7686 break;
7687
7688 cond_resched();
7689 }
7690
7691 return ret;
7692}
7693
7694/* The callers of this must take lock_extent() */
7695static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
7696 u64 orig_start, u64 block_start,
7697 u64 block_len, u64 orig_block_len,
7698 u64 ram_bytes, int compress_type,
7699 int type)
7700{
7701 struct extent_map_tree *em_tree;
7702 struct extent_map *em;
7703 struct btrfs_root *root = BTRFS_I(inode)->root;
7704 int ret;
7705
7706 ASSERT(type == BTRFS_ORDERED_PREALLOC ||
7707 type == BTRFS_ORDERED_COMPRESSED ||
7708 type == BTRFS_ORDERED_NOCOW ||
7709 type == BTRFS_ORDERED_REGULAR);
7710
7711 em_tree = &BTRFS_I(inode)->extent_tree;
7712 em = alloc_extent_map();
7713 if (!em)
7714 return ERR_PTR(-ENOMEM);
7715
7716 em->start = start;
7717 em->orig_start = orig_start;
7718 em->len = len;
7719 em->block_len = block_len;
7720 em->block_start = block_start;
7721 em->bdev = root->fs_info->fs_devices->latest_bdev;
7722 em->orig_block_len = orig_block_len;
7723 em->ram_bytes = ram_bytes;
7724 em->generation = -1;
7725 set_bit(EXTENT_FLAG_PINNED, &em->flags);
7726 if (type == BTRFS_ORDERED_PREALLOC) {
7727 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7728 } else if (type == BTRFS_ORDERED_COMPRESSED) {
7729 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
7730 em->compress_type = compress_type;
7731 }
7732
7733 do {
7734 btrfs_drop_extent_cache(BTRFS_I(inode), em->start,
7735 em->start + em->len - 1, 0);
7736 write_lock(&em_tree->lock);
7737 ret = add_extent_mapping(em_tree, em, 1);
7738 write_unlock(&em_tree->lock);
7739 /*
7740 * The caller has taken lock_extent(), who could race with us
7741 * to add em?
7742 */
7743 } while (ret == -EEXIST);
7744
7745 if (ret) {
7746 free_extent_map(em);
7747 return ERR_PTR(ret);
7748 }
7749
7750 /* em got 2 refs now, callers needs to do free_extent_map once. */
7751 return em;
7752}
7753
7754static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7755 struct buffer_head *bh_result, int create)
7756{
7757 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7758 struct extent_map *em;
7759 struct extent_state *cached_state = NULL;
7760 struct btrfs_dio_data *dio_data = NULL;
7761 u64 start = iblock << inode->i_blkbits;
7762 u64 lockstart, lockend;
7763 u64 len = bh_result->b_size;
7764 int unlock_bits = EXTENT_LOCKED;
7765 int ret = 0;
7766
7767 if (create)
7768 unlock_bits |= EXTENT_DIRTY;
7769 else
7770 len = min_t(u64, len, fs_info->sectorsize);
7771
7772 lockstart = start;
7773 lockend = start + len - 1;
7774
7775 if (current->journal_info) {
7776 /*
7777 * Need to pull our outstanding extents and set journal_info to NULL so
7778 * that anything that needs to check if there's a transaction doesn't get
7779 * confused.
7780 */
7781 dio_data = current->journal_info;
7782 current->journal_info = NULL;
7783 }
7784
7785 /*
7786 * If this errors out it's because we couldn't invalidate pagecache for
7787 * this range and we need to fallback to buffered.
7788 */
7789 if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
7790 create)) {
7791 ret = -ENOTBLK;
7792 goto err;
7793 }
7794
7795 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
7796 if (IS_ERR(em)) {
7797 ret = PTR_ERR(em);
7798 goto unlock_err;
7799 }
7800
7801 /*
7802 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7803 * io. INLINE is special, and we could probably kludge it in here, but
7804 * it's still buffered so for safety lets just fall back to the generic
7805 * buffered path.
7806 *
7807 * For COMPRESSED we _have_ to read the entire extent in so we can
7808 * decompress it, so there will be buffering required no matter what we
7809 * do, so go ahead and fallback to buffered.
7810 *
7811 * We return -ENOTBLK because that's what makes DIO go ahead and go back
7812 * to buffered IO. Don't blame me, this is the price we pay for using
7813 * the generic code.
7814 */
7815 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7816 em->block_start == EXTENT_MAP_INLINE) {
7817 free_extent_map(em);
7818 ret = -ENOTBLK;
7819 goto unlock_err;
7820 }
7821
7822 /* Just a good old fashioned hole, return */
7823 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
7824 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
7825 free_extent_map(em);
7826 goto unlock_err;
7827 }
7828
7829 /*
7830 * We don't allocate a new extent in the following cases
7831 *
7832 * 1) The inode is marked as NODATACOW. In this case we'll just use the
7833 * existing extent.
7834 * 2) The extent is marked as PREALLOC. We're good to go here and can
7835 * just use the extent.
7836 *
7837 */
7838 if (!create) {
7839 len = min(len, em->len - (start - em->start));
7840 lockstart = start + len;
7841 goto unlock;
7842 }
7843
7844 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7845 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7846 em->block_start != EXTENT_MAP_HOLE)) {
7847 int type;
7848 u64 block_start, orig_start, orig_block_len, ram_bytes;
7849
7850 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7851 type = BTRFS_ORDERED_PREALLOC;
7852 else
7853 type = BTRFS_ORDERED_NOCOW;
7854 len = min(len, em->len - (start - em->start));
7855 block_start = em->block_start + (start - em->start);
7856
7857 if (can_nocow_extent(inode, start, &len, &orig_start,
7858 &orig_block_len, &ram_bytes) == 1 &&
7859 btrfs_inc_nocow_writers(fs_info, block_start)) {
7860 struct extent_map *em2;
7861
7862 em2 = btrfs_create_dio_extent(inode, start, len,
7863 orig_start, block_start,
7864 len, orig_block_len,
7865 ram_bytes, type);
7866 btrfs_dec_nocow_writers(fs_info, block_start);
7867 if (type == BTRFS_ORDERED_PREALLOC) {
7868 free_extent_map(em);
7869 em = em2;
7870 }
7871 if (em2 && IS_ERR(em2)) {
7872 ret = PTR_ERR(em2);
7873 goto unlock_err;
7874 }
7875 /*
7876 * For inode marked NODATACOW or extent marked PREALLOC,
7877 * use the existing or preallocated extent, so does not
7878 * need to adjust btrfs_space_info's bytes_may_use.
7879 */
7880 btrfs_free_reserved_data_space_noquota(inode,
7881 start, len);
7882 goto unlock;
7883 }
7884 }
7885
7886 /*
7887 * this will cow the extent, reset the len in case we changed
7888 * it above
7889 */
7890 len = bh_result->b_size;
7891 free_extent_map(em);
7892 em = btrfs_new_extent_direct(inode, start, len);
7893 if (IS_ERR(em)) {
7894 ret = PTR_ERR(em);
7895 goto unlock_err;
7896 }
7897 len = min(len, em->len - (start - em->start));
7898unlock:
7899 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7900 inode->i_blkbits;
7901 bh_result->b_size = len;
7902 bh_result->b_bdev = em->bdev;
7903 set_buffer_mapped(bh_result);
7904 if (create) {
7905 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7906 set_buffer_new(bh_result);
7907
7908 /*
7909 * Need to update the i_size under the extent lock so buffered
7910 * readers will get the updated i_size when we unlock.
7911 */
7912 if (!dio_data->overwrite && start + len > i_size_read(inode))
7913 i_size_write(inode, start + len);
7914
7915 WARN_ON(dio_data->reserve < len);
7916 dio_data->reserve -= len;
7917 dio_data->unsubmitted_oe_range_end = start + len;
7918 current->journal_info = dio_data;
7919 }
7920
7921 /*
7922 * In the case of write we need to clear and unlock the entire range,
7923 * in the case of read we need to unlock only the end area that we
7924 * aren't using if there is any left over space.
7925 */
7926 if (lockstart < lockend) {
7927 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7928 lockend, unlock_bits, 1, 0,
7929 &cached_state, GFP_NOFS);
7930 } else {
7931 free_extent_state(cached_state);
7932 }
7933
7934 free_extent_map(em);
7935
7936 return 0;
7937
7938unlock_err:
7939 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7940 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
7941err:
7942 if (dio_data)
7943 current->journal_info = dio_data;
7944 return ret;
7945}
7946
7947static inline blk_status_t submit_dio_repair_bio(struct inode *inode,
7948 struct bio *bio,
7949 int mirror_num)
7950{
7951 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7952 blk_status_t ret;
7953
7954 BUG_ON(bio_op(bio) == REQ_OP_WRITE);
7955
7956 bio_get(bio);
7957
7958 ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DIO_REPAIR);
7959 if (ret)
7960 goto err;
7961
7962 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
7963err:
7964 bio_put(bio);
7965 return ret;
7966}
7967
7968static int btrfs_check_dio_repairable(struct inode *inode,
7969 struct bio *failed_bio,
7970 struct io_failure_record *failrec,
7971 int failed_mirror)
7972{
7973 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7974 int num_copies;
7975
7976 num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len);
7977 if (num_copies == 1) {
7978 /*
7979 * we only have a single copy of the data, so don't bother with
7980 * all the retry and error correction code that follows. no
7981 * matter what the error is, it is very likely to persist.
7982 */
7983 btrfs_debug(fs_info,
7984 "Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
7985 num_copies, failrec->this_mirror, failed_mirror);
7986 return 0;
7987 }
7988
7989 failrec->failed_mirror = failed_mirror;
7990 failrec->this_mirror++;
7991 if (failrec->this_mirror == failed_mirror)
7992 failrec->this_mirror++;
7993
7994 if (failrec->this_mirror > num_copies) {
7995 btrfs_debug(fs_info,
7996 "Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
7997 num_copies, failrec->this_mirror, failed_mirror);
7998 return 0;
7999 }
8000
8001 return 1;
8002}
8003
8004static blk_status_t dio_read_error(struct inode *inode, struct bio *failed_bio,
8005 struct page *page, unsigned int pgoff,
8006 u64 start, u64 end, int failed_mirror,
8007 bio_end_io_t *repair_endio, void *repair_arg)
8008{
8009 struct io_failure_record *failrec;
8010 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8011 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
8012 struct bio *bio;
8013 int isector;
8014 unsigned int read_mode = 0;
8015 int segs;
8016 int ret;
8017 blk_status_t status;
8018
8019 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
8020
8021 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
8022 if (ret)
8023 return errno_to_blk_status(ret);
8024
8025 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
8026 failed_mirror);
8027 if (!ret) {
8028 free_io_failure(failure_tree, io_tree, failrec);
8029 return BLK_STS_IOERR;
8030 }
8031
8032 segs = bio_segments(failed_bio);
8033 if (segs > 1 ||
8034 (failed_bio->bi_io_vec->bv_len > btrfs_inode_sectorsize(inode)))
8035 read_mode |= REQ_FAILFAST_DEV;
8036
8037 isector = start - btrfs_io_bio(failed_bio)->logical;
8038 isector >>= inode->i_sb->s_blocksize_bits;
8039 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
8040 pgoff, isector, repair_endio, repair_arg);
8041 bio_set_op_attrs(bio, REQ_OP_READ, read_mode);
8042
8043 btrfs_debug(BTRFS_I(inode)->root->fs_info,
8044 "repair DIO read error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d",
8045 read_mode, failrec->this_mirror, failrec->in_validation);
8046
8047 status = submit_dio_repair_bio(inode, bio, failrec->this_mirror);
8048 if (status) {
8049 free_io_failure(failure_tree, io_tree, failrec);
8050 bio_put(bio);
8051 }
8052
8053 return status;
8054}
8055
8056struct btrfs_retry_complete {
8057 struct completion done;
8058 struct inode *inode;
8059 u64 start;
8060 int uptodate;
8061};
8062
8063static void btrfs_retry_endio_nocsum(struct bio *bio)
8064{
8065 struct btrfs_retry_complete *done = bio->bi_private;
8066 struct inode *inode = done->inode;
8067 struct bio_vec *bvec;
8068 struct extent_io_tree *io_tree, *failure_tree;
8069 int i;
8070
8071 if (bio->bi_status)
8072 goto end;
8073
8074 ASSERT(bio->bi_vcnt == 1);
8075 io_tree = &BTRFS_I(inode)->io_tree;
8076 failure_tree = &BTRFS_I(inode)->io_failure_tree;
8077 ASSERT(bio->bi_io_vec->bv_len == btrfs_inode_sectorsize(inode));
8078
8079 done->uptodate = 1;
8080 ASSERT(!bio_flagged(bio, BIO_CLONED));
8081 bio_for_each_segment_all(bvec, bio, i)
8082 clean_io_failure(BTRFS_I(inode)->root->fs_info, failure_tree,
8083 io_tree, done->start, bvec->bv_page,
8084 btrfs_ino(BTRFS_I(inode)), 0);
8085end:
8086 complete(&done->done);
8087 bio_put(bio);
8088}
8089
8090static blk_status_t __btrfs_correct_data_nocsum(struct inode *inode,
8091 struct btrfs_io_bio *io_bio)
8092{
8093 struct btrfs_fs_info *fs_info;
8094 struct bio_vec bvec;
8095 struct bvec_iter iter;
8096 struct btrfs_retry_complete done;
8097 u64 start;
8098 unsigned int pgoff;
8099 u32 sectorsize;
8100 int nr_sectors;
8101 blk_status_t ret;
8102 blk_status_t err = BLK_STS_OK;
8103
8104 fs_info = BTRFS_I(inode)->root->fs_info;
8105 sectorsize = fs_info->sectorsize;
8106
8107 start = io_bio->logical;
8108 done.inode = inode;
8109 io_bio->bio.bi_iter = io_bio->iter;
8110
8111 bio_for_each_segment(bvec, &io_bio->bio, iter) {
8112 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
8113 pgoff = bvec.bv_offset;
8114
8115next_block_or_try_again:
8116 done.uptodate = 0;
8117 done.start = start;
8118 init_completion(&done.done);
8119
8120 ret = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
8121 pgoff, start, start + sectorsize - 1,
8122 io_bio->mirror_num,
8123 btrfs_retry_endio_nocsum, &done);
8124 if (ret) {
8125 err = ret;
8126 goto next;
8127 }
8128
8129 wait_for_completion_io(&done.done);
8130
8131 if (!done.uptodate) {
8132 /* We might have another mirror, so try again */
8133 goto next_block_or_try_again;
8134 }
8135
8136next:
8137 start += sectorsize;
8138
8139 nr_sectors--;
8140 if (nr_sectors) {
8141 pgoff += sectorsize;
8142 ASSERT(pgoff < PAGE_SIZE);
8143 goto next_block_or_try_again;
8144 }
8145 }
8146
8147 return err;
8148}
8149
8150static void btrfs_retry_endio(struct bio *bio)
8151{
8152 struct btrfs_retry_complete *done = bio->bi_private;
8153 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8154 struct extent_io_tree *io_tree, *failure_tree;
8155 struct inode *inode = done->inode;
8156 struct bio_vec *bvec;
8157 int uptodate;
8158 int ret;
8159 int i;
8160
8161 if (bio->bi_status)
8162 goto end;
8163
8164 uptodate = 1;
8165
8166 ASSERT(bio->bi_vcnt == 1);
8167 ASSERT(bio->bi_io_vec->bv_len == btrfs_inode_sectorsize(done->inode));
8168
8169 io_tree = &BTRFS_I(inode)->io_tree;
8170 failure_tree = &BTRFS_I(inode)->io_failure_tree;
8171
8172 ASSERT(!bio_flagged(bio, BIO_CLONED));
8173 bio_for_each_segment_all(bvec, bio, i) {
8174 ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page,
8175 bvec->bv_offset, done->start,
8176 bvec->bv_len);
8177 if (!ret)
8178 clean_io_failure(BTRFS_I(inode)->root->fs_info,
8179 failure_tree, io_tree, done->start,
8180 bvec->bv_page,
8181 btrfs_ino(BTRFS_I(inode)),
8182 bvec->bv_offset);
8183 else
8184 uptodate = 0;
8185 }
8186
8187 done->uptodate = uptodate;
8188end:
8189 complete(&done->done);
8190 bio_put(bio);
8191}
8192
8193static blk_status_t __btrfs_subio_endio_read(struct inode *inode,
8194 struct btrfs_io_bio *io_bio, blk_status_t err)
8195{
8196 struct btrfs_fs_info *fs_info;
8197 struct bio_vec bvec;
8198 struct bvec_iter iter;
8199 struct btrfs_retry_complete done;
8200 u64 start;
8201 u64 offset = 0;
8202 u32 sectorsize;
8203 int nr_sectors;
8204 unsigned int pgoff;
8205 int csum_pos;
8206 bool uptodate = (err == 0);
8207 int ret;
8208 blk_status_t status;
8209
8210 fs_info = BTRFS_I(inode)->root->fs_info;
8211 sectorsize = fs_info->sectorsize;
8212
8213 err = BLK_STS_OK;
8214 start = io_bio->logical;
8215 done.inode = inode;
8216 io_bio->bio.bi_iter = io_bio->iter;
8217
8218 bio_for_each_segment(bvec, &io_bio->bio, iter) {
8219 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
8220
8221 pgoff = bvec.bv_offset;
8222next_block:
8223 if (uptodate) {
8224 csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset);
8225 ret = __readpage_endio_check(inode, io_bio, csum_pos,
8226 bvec.bv_page, pgoff, start, sectorsize);
8227 if (likely(!ret))
8228 goto next;
8229 }
8230try_again:
8231 done.uptodate = 0;
8232 done.start = start;
8233 init_completion(&done.done);
8234
8235 status = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
8236 pgoff, start, start + sectorsize - 1,
8237 io_bio->mirror_num, btrfs_retry_endio,
8238 &done);
8239 if (status) {
8240 err = status;
8241 goto next;
8242 }
8243
8244 wait_for_completion_io(&done.done);
8245
8246 if (!done.uptodate) {
8247 /* We might have another mirror, so try again */
8248 goto try_again;
8249 }
8250next:
8251 offset += sectorsize;
8252 start += sectorsize;
8253
8254 ASSERT(nr_sectors);
8255
8256 nr_sectors--;
8257 if (nr_sectors) {
8258 pgoff += sectorsize;
8259 ASSERT(pgoff < PAGE_SIZE);
8260 goto next_block;
8261 }
8262 }
8263
8264 return err;
8265}
8266
8267static blk_status_t btrfs_subio_endio_read(struct inode *inode,
8268 struct btrfs_io_bio *io_bio, blk_status_t err)
8269{
8270 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8271
8272 if (skip_csum) {
8273 if (unlikely(err))
8274 return __btrfs_correct_data_nocsum(inode, io_bio);
8275 else
8276 return BLK_STS_OK;
8277 } else {
8278 return __btrfs_subio_endio_read(inode, io_bio, err);
8279 }
8280}
8281
8282static void btrfs_endio_direct_read(struct bio *bio)
8283{
8284 struct btrfs_dio_private *dip = bio->bi_private;
8285 struct inode *inode = dip->inode;
8286 struct bio *dio_bio;
8287 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8288 blk_status_t err = bio->bi_status;
8289
8290 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
8291 err = btrfs_subio_endio_read(inode, io_bio, err);
8292
8293 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
8294 dip->logical_offset + dip->bytes - 1);
8295 dio_bio = dip->dio_bio;
8296
8297 kfree(dip);
8298
8299 dio_bio->bi_status = err;
8300 dio_end_io(dio_bio);
8301
8302 if (io_bio->end_io)
8303 io_bio->end_io(io_bio, blk_status_to_errno(err));
8304 bio_put(bio);
8305}
8306
8307static void __endio_write_update_ordered(struct inode *inode,
8308 const u64 offset, const u64 bytes,
8309 const bool uptodate)
8310{
8311 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8312 struct btrfs_ordered_extent *ordered = NULL;
8313 struct btrfs_workqueue *wq;
8314 btrfs_work_func_t func;
8315 u64 ordered_offset = offset;
8316 u64 ordered_bytes = bytes;
8317 u64 last_offset;
8318 int ret;
8319
8320 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
8321 wq = fs_info->endio_freespace_worker;
8322 func = btrfs_freespace_write_helper;
8323 } else {
8324 wq = fs_info->endio_write_workers;
8325 func = btrfs_endio_write_helper;
8326 }
8327
8328again:
8329 last_offset = ordered_offset;
8330 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
8331 &ordered_offset,
8332 ordered_bytes,
8333 uptodate);
8334 if (!ret)
8335 goto out_test;
8336
8337 btrfs_init_work(&ordered->work, func, finish_ordered_fn, NULL, NULL);
8338 btrfs_queue_work(wq, &ordered->work);
8339out_test:
8340 /*
8341 * If btrfs_dec_test_ordered_pending does not find any ordered extent
8342 * in the range, we can exit.
8343 */
8344 if (ordered_offset == last_offset)
8345 return;
8346 /*
8347 * our bio might span multiple ordered extents. If we haven't
8348 * completed the accounting for the whole dio, go back and try again
8349 */
8350 if (ordered_offset < offset + bytes) {
8351 ordered_bytes = offset + bytes - ordered_offset;
8352 ordered = NULL;
8353 goto again;
8354 }
8355}
8356
8357static void btrfs_endio_direct_write(struct bio *bio)
8358{
8359 struct btrfs_dio_private *dip = bio->bi_private;
8360 struct bio *dio_bio = dip->dio_bio;
8361
8362 __endio_write_update_ordered(dip->inode, dip->logical_offset,
8363 dip->bytes, !bio->bi_status);
8364
8365 kfree(dip);
8366
8367 dio_bio->bi_status = bio->bi_status;
8368 dio_end_io(dio_bio);
8369 bio_put(bio);
8370}
8371
8372static blk_status_t __btrfs_submit_bio_start_direct_io(void *private_data,
8373 struct bio *bio, int mirror_num,
8374 unsigned long bio_flags, u64 offset)
8375{
8376 struct inode *inode = private_data;
8377 blk_status_t ret;
8378 ret = btrfs_csum_one_bio(inode, bio, offset, 1);
8379 BUG_ON(ret); /* -ENOMEM */
8380 return 0;
8381}
8382
8383static void btrfs_end_dio_bio(struct bio *bio)
8384{
8385 struct btrfs_dio_private *dip = bio->bi_private;
8386 blk_status_t err = bio->bi_status;
8387
8388 if (err)
8389 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
8390 "direct IO failed ino %llu rw %d,%u sector %#Lx len %u err no %d",
8391 btrfs_ino(BTRFS_I(dip->inode)), bio_op(bio),
8392 bio->bi_opf,
8393 (unsigned long long)bio->bi_iter.bi_sector,
8394 bio->bi_iter.bi_size, err);
8395
8396 if (dip->subio_endio)
8397 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
8398
8399 if (err) {
8400 dip->errors = 1;
8401
8402 /*
8403 * before atomic variable goto zero, we must make sure
8404 * dip->errors is perceived to be set.
8405 */
8406 smp_mb__before_atomic();
8407 }
8408
8409 /* if there are more bios still pending for this dio, just exit */
8410 if (!atomic_dec_and_test(&dip->pending_bios))
8411 goto out;
8412
8413 if (dip->errors) {
8414 bio_io_error(dip->orig_bio);
8415 } else {
8416 dip->dio_bio->bi_status = BLK_STS_OK;
8417 bio_endio(dip->orig_bio);
8418 }
8419out:
8420 bio_put(bio);
8421}
8422
8423static inline blk_status_t btrfs_lookup_and_bind_dio_csum(struct inode *inode,
8424 struct btrfs_dio_private *dip,
8425 struct bio *bio,
8426 u64 file_offset)
8427{
8428 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8429 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
8430 blk_status_t ret;
8431
8432 /*
8433 * We load all the csum data we need when we submit
8434 * the first bio to reduce the csum tree search and
8435 * contention.
8436 */
8437 if (dip->logical_offset == file_offset) {
8438 ret = btrfs_lookup_bio_sums_dio(inode, dip->orig_bio,
8439 file_offset);
8440 if (ret)
8441 return ret;
8442 }
8443
8444 if (bio == dip->orig_bio)
8445 return 0;
8446
8447 file_offset -= dip->logical_offset;
8448 file_offset >>= inode->i_sb->s_blocksize_bits;
8449 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
8450
8451 return 0;
8452}
8453
8454static inline blk_status_t
8455__btrfs_submit_dio_bio(struct bio *bio, struct inode *inode, u64 file_offset,
8456 int async_submit)
8457{
8458 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8459 struct btrfs_dio_private *dip = bio->bi_private;
8460 bool write = bio_op(bio) == REQ_OP_WRITE;
8461 blk_status_t ret;
8462
8463 if (async_submit)
8464 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
8465
8466 bio_get(bio);
8467
8468 if (!write) {
8469 ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA);
8470 if (ret)
8471 goto err;
8472 }
8473
8474 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
8475 goto map;
8476
8477 if (write && async_submit) {
8478 ret = btrfs_wq_submit_bio(fs_info, bio, 0, 0,
8479 file_offset, inode,
8480 __btrfs_submit_bio_start_direct_io,
8481 __btrfs_submit_bio_done);
8482 goto err;
8483 } else if (write) {
8484 /*
8485 * If we aren't doing async submit, calculate the csum of the
8486 * bio now.
8487 */
8488 ret = btrfs_csum_one_bio(inode, bio, file_offset, 1);
8489 if (ret)
8490 goto err;
8491 } else {
8492 ret = btrfs_lookup_and_bind_dio_csum(inode, dip, bio,
8493 file_offset);
8494 if (ret)
8495 goto err;
8496 }
8497map:
8498 ret = btrfs_map_bio(fs_info, bio, 0, 0);
8499err:
8500 bio_put(bio);
8501 return ret;
8502}
8503
8504static int btrfs_submit_direct_hook(struct btrfs_dio_private *dip)
8505{
8506 struct inode *inode = dip->inode;
8507 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8508 struct bio *bio;
8509 struct bio *orig_bio = dip->orig_bio;
8510 u64 start_sector = orig_bio->bi_iter.bi_sector;
8511 u64 file_offset = dip->logical_offset;
8512 u64 map_length;
8513 int async_submit = 0;
8514 u64 submit_len;
8515 int clone_offset = 0;
8516 int clone_len;
8517 int ret;
8518 blk_status_t status;
8519
8520 map_length = orig_bio->bi_iter.bi_size;
8521 submit_len = map_length;
8522 ret = btrfs_map_block(fs_info, btrfs_op(orig_bio), start_sector << 9,
8523 &map_length, NULL, 0);
8524 if (ret)
8525 return -EIO;
8526
8527 if (map_length >= submit_len) {
8528 bio = orig_bio;
8529 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8530 goto submit;
8531 }
8532
8533 /* async crcs make it difficult to collect full stripe writes. */
8534 if (btrfs_data_alloc_profile(fs_info) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8535 async_submit = 0;
8536 else
8537 async_submit = 1;
8538
8539 /* bio split */
8540 ASSERT(map_length <= INT_MAX);
8541 atomic_inc(&dip->pending_bios);
8542 do {
8543 clone_len = min_t(int, submit_len, map_length);
8544
8545 /*
8546 * This will never fail as it's passing GPF_NOFS and
8547 * the allocation is backed by btrfs_bioset.
8548 */
8549 bio = btrfs_bio_clone_partial(orig_bio, clone_offset,
8550 clone_len);
8551 bio->bi_private = dip;
8552 bio->bi_end_io = btrfs_end_dio_bio;
8553 btrfs_io_bio(bio)->logical = file_offset;
8554
8555 ASSERT(submit_len >= clone_len);
8556 submit_len -= clone_len;
8557 if (submit_len == 0)
8558 break;
8559
8560 /*
8561 * Increase the count before we submit the bio so we know
8562 * the end IO handler won't happen before we increase the
8563 * count. Otherwise, the dip might get freed before we're
8564 * done setting it up.
8565 */
8566 atomic_inc(&dip->pending_bios);
8567
8568 status = __btrfs_submit_dio_bio(bio, inode, file_offset,
8569 async_submit);
8570 if (status) {
8571 bio_put(bio);
8572 atomic_dec(&dip->pending_bios);
8573 goto out_err;
8574 }
8575
8576 clone_offset += clone_len;
8577 start_sector += clone_len >> 9;
8578 file_offset += clone_len;
8579
8580 map_length = submit_len;
8581 ret = btrfs_map_block(fs_info, btrfs_op(orig_bio),
8582 start_sector << 9, &map_length, NULL, 0);
8583 if (ret)
8584 goto out_err;
8585 } while (submit_len > 0);
8586
8587submit:
8588 status = __btrfs_submit_dio_bio(bio, inode, file_offset, async_submit);
8589 if (!status)
8590 return 0;
8591
8592 bio_put(bio);
8593out_err:
8594 dip->errors = 1;
8595 /*
8596 * before atomic variable goto zero, we must
8597 * make sure dip->errors is perceived to be set.
8598 */
8599 smp_mb__before_atomic();
8600 if (atomic_dec_and_test(&dip->pending_bios))
8601 bio_io_error(dip->orig_bio);
8602
8603 /* bio_end_io() will handle error, so we needn't return it */
8604 return 0;
8605}
8606
8607static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode,
8608 loff_t file_offset)
8609{
8610 struct btrfs_dio_private *dip = NULL;
8611 struct bio *bio = NULL;
8612 struct btrfs_io_bio *io_bio;
8613 bool write = (bio_op(dio_bio) == REQ_OP_WRITE);
8614 int ret = 0;
8615
8616 bio = btrfs_bio_clone(dio_bio);
8617
8618 dip = kzalloc(sizeof(*dip), GFP_NOFS);
8619 if (!dip) {
8620 ret = -ENOMEM;
8621 goto free_ordered;
8622 }
8623
8624 dip->private = dio_bio->bi_private;
8625 dip->inode = inode;
8626 dip->logical_offset = file_offset;
8627 dip->bytes = dio_bio->bi_iter.bi_size;
8628 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8629 bio->bi_private = dip;
8630 dip->orig_bio = bio;
8631 dip->dio_bio = dio_bio;
8632 atomic_set(&dip->pending_bios, 0);
8633 io_bio = btrfs_io_bio(bio);
8634 io_bio->logical = file_offset;
8635
8636 if (write) {
8637 bio->bi_end_io = btrfs_endio_direct_write;
8638 } else {
8639 bio->bi_end_io = btrfs_endio_direct_read;
8640 dip->subio_endio = btrfs_subio_endio_read;
8641 }
8642
8643 /*
8644 * Reset the range for unsubmitted ordered extents (to a 0 length range)
8645 * even if we fail to submit a bio, because in such case we do the
8646 * corresponding error handling below and it must not be done a second
8647 * time by btrfs_direct_IO().
8648 */
8649 if (write) {
8650 struct btrfs_dio_data *dio_data = current->journal_info;
8651
8652 dio_data->unsubmitted_oe_range_end = dip->logical_offset +
8653 dip->bytes;
8654 dio_data->unsubmitted_oe_range_start =
8655 dio_data->unsubmitted_oe_range_end;
8656 }
8657
8658 ret = btrfs_submit_direct_hook(dip);
8659 if (!ret)
8660 return;
8661
8662 if (io_bio->end_io)
8663 io_bio->end_io(io_bio, ret);
8664
8665free_ordered:
8666 /*
8667 * If we arrived here it means either we failed to submit the dip
8668 * or we either failed to clone the dio_bio or failed to allocate the
8669 * dip. If we cloned the dio_bio and allocated the dip, we can just
8670 * call bio_endio against our io_bio so that we get proper resource
8671 * cleanup if we fail to submit the dip, otherwise, we must do the
8672 * same as btrfs_endio_direct_[write|read] because we can't call these
8673 * callbacks - they require an allocated dip and a clone of dio_bio.
8674 */
8675 if (bio && dip) {
8676 bio_io_error(bio);
8677 /*
8678 * The end io callbacks free our dip, do the final put on bio
8679 * and all the cleanup and final put for dio_bio (through
8680 * dio_end_io()).
8681 */
8682 dip = NULL;
8683 bio = NULL;
8684 } else {
8685 if (write)
8686 __endio_write_update_ordered(inode,
8687 file_offset,
8688 dio_bio->bi_iter.bi_size,
8689 false);
8690 else
8691 unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
8692 file_offset + dio_bio->bi_iter.bi_size - 1);
8693
8694 dio_bio->bi_status = BLK_STS_IOERR;
8695 /*
8696 * Releases and cleans up our dio_bio, no need to bio_put()
8697 * nor bio_endio()/bio_io_error() against dio_bio.
8698 */
8699 dio_end_io(dio_bio);
8700 }
8701 if (bio)
8702 bio_put(bio);
8703 kfree(dip);
8704}
8705
8706static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info,
8707 const struct iov_iter *iter, loff_t offset)
8708{
8709 int seg;
8710 int i;
8711 unsigned int blocksize_mask = fs_info->sectorsize - 1;
8712 ssize_t retval = -EINVAL;
8713
8714 if (offset & blocksize_mask)
8715 goto out;
8716
8717 if (iov_iter_alignment(iter) & blocksize_mask)
8718 goto out;
8719
8720 /* If this is a write we don't need to check anymore */
8721 if (iov_iter_rw(iter) != READ || !iter_is_iovec(iter))
8722 return 0;
8723 /*
8724 * Check to make sure we don't have duplicate iov_base's in this
8725 * iovec, if so return EINVAL, otherwise we'll get csum errors
8726 * when reading back.
8727 */
8728 for (seg = 0; seg < iter->nr_segs; seg++) {
8729 for (i = seg + 1; i < iter->nr_segs; i++) {
8730 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8731 goto out;
8732 }
8733 }
8734 retval = 0;
8735out:
8736 return retval;
8737}
8738
8739static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
8740{
8741 struct file *file = iocb->ki_filp;
8742 struct inode *inode = file->f_mapping->host;
8743 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8744 struct btrfs_dio_data dio_data = { 0 };
8745 struct extent_changeset *data_reserved = NULL;
8746 loff_t offset = iocb->ki_pos;
8747 size_t count = 0;
8748 int flags = 0;
8749 bool wakeup = true;
8750 bool relock = false;
8751 ssize_t ret;
8752
8753 if (check_direct_IO(fs_info, iter, offset))
8754 return 0;
8755
8756 inode_dio_begin(inode);
8757
8758 /*
8759 * The generic stuff only does filemap_write_and_wait_range, which
8760 * isn't enough if we've written compressed pages to this area, so
8761 * we need to flush the dirty pages again to make absolutely sure
8762 * that any outstanding dirty pages are on disk.
8763 */
8764 count = iov_iter_count(iter);
8765 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8766 &BTRFS_I(inode)->runtime_flags))
8767 filemap_fdatawrite_range(inode->i_mapping, offset,
8768 offset + count - 1);
8769
8770 if (iov_iter_rw(iter) == WRITE) {
8771 /*
8772 * If the write DIO is beyond the EOF, we need update
8773 * the isize, but it is protected by i_mutex. So we can
8774 * not unlock the i_mutex at this case.
8775 */
8776 if (offset + count <= inode->i_size) {
8777 dio_data.overwrite = 1;
8778 inode_unlock(inode);
8779 relock = true;
8780 } else if (iocb->ki_flags & IOCB_NOWAIT) {
8781 ret = -EAGAIN;
8782 goto out;
8783 }
8784 ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
8785 offset, count);
8786 if (ret)
8787 goto out;
8788
8789 /*
8790 * We need to know how many extents we reserved so that we can
8791 * do the accounting properly if we go over the number we
8792 * originally calculated. Abuse current->journal_info for this.
8793 */
8794 dio_data.reserve = round_up(count,
8795 fs_info->sectorsize);
8796 dio_data.unsubmitted_oe_range_start = (u64)offset;
8797 dio_data.unsubmitted_oe_range_end = (u64)offset;
8798 current->journal_info = &dio_data;
8799 down_read(&BTRFS_I(inode)->dio_sem);
8800 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8801 &BTRFS_I(inode)->runtime_flags)) {
8802 inode_dio_end(inode);
8803 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8804 wakeup = false;
8805 }
8806
8807 ret = __blockdev_direct_IO(iocb, inode,
8808 fs_info->fs_devices->latest_bdev,
8809 iter, btrfs_get_blocks_direct, NULL,
8810 btrfs_submit_direct, flags);
8811 if (iov_iter_rw(iter) == WRITE) {
8812 up_read(&BTRFS_I(inode)->dio_sem);
8813 current->journal_info = NULL;
8814 if (ret < 0 && ret != -EIOCBQUEUED) {
8815 if (dio_data.reserve)
8816 btrfs_delalloc_release_space(inode, data_reserved,
8817 offset, dio_data.reserve);
8818 /*
8819 * On error we might have left some ordered extents
8820 * without submitting corresponding bios for them, so
8821 * cleanup them up to avoid other tasks getting them
8822 * and waiting for them to complete forever.
8823 */
8824 if (dio_data.unsubmitted_oe_range_start <
8825 dio_data.unsubmitted_oe_range_end)
8826 __endio_write_update_ordered(inode,
8827 dio_data.unsubmitted_oe_range_start,
8828 dio_data.unsubmitted_oe_range_end -
8829 dio_data.unsubmitted_oe_range_start,
8830 false);
8831 } else if (ret >= 0 && (size_t)ret < count)
8832 btrfs_delalloc_release_space(inode, data_reserved,
8833 offset, count - (size_t)ret);
8834 btrfs_delalloc_release_extents(BTRFS_I(inode), count);
8835 }
8836out:
8837 if (wakeup)
8838 inode_dio_end(inode);
8839 if (relock)
8840 inode_lock(inode);
8841
8842 extent_changeset_free(data_reserved);
8843 return ret;
8844}
8845
8846#define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
8847
8848static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8849 __u64 start, __u64 len)
8850{
8851 int ret;
8852
8853 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8854 if (ret)
8855 return ret;
8856
8857 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
8858}
8859
8860int btrfs_readpage(struct file *file, struct page *page)
8861{
8862 struct extent_io_tree *tree;
8863 tree = &BTRFS_I(page->mapping->host)->io_tree;
8864 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8865}
8866
8867static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8868{
8869 struct extent_io_tree *tree;
8870 struct inode *inode = page->mapping->host;
8871 int ret;
8872
8873 if (current->flags & PF_MEMALLOC) {
8874 redirty_page_for_writepage(wbc, page);
8875 unlock_page(page);
8876 return 0;
8877 }
8878
8879 /*
8880 * If we are under memory pressure we will call this directly from the
8881 * VM, we need to make sure we have the inode referenced for the ordered
8882 * extent. If not just return like we didn't do anything.
8883 */
8884 if (!igrab(inode)) {
8885 redirty_page_for_writepage(wbc, page);
8886 return AOP_WRITEPAGE_ACTIVATE;
8887 }
8888 tree = &BTRFS_I(page->mapping->host)->io_tree;
8889 ret = extent_write_full_page(tree, page, btrfs_get_extent, wbc);
8890 btrfs_add_delayed_iput(inode);
8891 return ret;
8892}
8893
8894static int btrfs_writepages(struct address_space *mapping,
8895 struct writeback_control *wbc)
8896{
8897 struct extent_io_tree *tree;
8898
8899 tree = &BTRFS_I(mapping->host)->io_tree;
8900 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
8901}
8902
8903static int
8904btrfs_readpages(struct file *file, struct address_space *mapping,
8905 struct list_head *pages, unsigned nr_pages)
8906{
8907 struct extent_io_tree *tree;
8908 tree = &BTRFS_I(mapping->host)->io_tree;
8909 return extent_readpages(tree, mapping, pages, nr_pages,
8910 btrfs_get_extent);
8911}
8912static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8913{
8914 struct extent_io_tree *tree;
8915 struct extent_map_tree *map;
8916 int ret;
8917
8918 tree = &BTRFS_I(page->mapping->host)->io_tree;
8919 map = &BTRFS_I(page->mapping->host)->extent_tree;
8920 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
8921 if (ret == 1) {
8922 ClearPagePrivate(page);
8923 set_page_private(page, 0);
8924 put_page(page);
8925 }
8926 return ret;
8927}
8928
8929static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8930{
8931 if (PageWriteback(page) || PageDirty(page))
8932 return 0;
8933 return __btrfs_releasepage(page, gfp_flags);
8934}
8935
8936static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8937 unsigned int length)
8938{
8939 struct inode *inode = page->mapping->host;
8940 struct extent_io_tree *tree;
8941 struct btrfs_ordered_extent *ordered;
8942 struct extent_state *cached_state = NULL;
8943 u64 page_start = page_offset(page);
8944 u64 page_end = page_start + PAGE_SIZE - 1;
8945 u64 start;
8946 u64 end;
8947 int inode_evicting = inode->i_state & I_FREEING;
8948
8949 /*
8950 * we have the page locked, so new writeback can't start,
8951 * and the dirty bit won't be cleared while we are here.
8952 *
8953 * Wait for IO on this page so that we can safely clear
8954 * the PagePrivate2 bit and do ordered accounting
8955 */
8956 wait_on_page_writeback(page);
8957
8958 tree = &BTRFS_I(inode)->io_tree;
8959 if (offset) {
8960 btrfs_releasepage(page, GFP_NOFS);
8961 return;
8962 }
8963
8964 if (!inode_evicting)
8965 lock_extent_bits(tree, page_start, page_end, &cached_state);
8966again:
8967 start = page_start;
8968 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
8969 page_end - start + 1);
8970 if (ordered) {
8971 end = min(page_end, ordered->file_offset + ordered->len - 1);
8972 /*
8973 * IO on this page will never be started, so we need
8974 * to account for any ordered extents now
8975 */
8976 if (!inode_evicting)
8977 clear_extent_bit(tree, start, end,
8978 EXTENT_DIRTY | EXTENT_DELALLOC |
8979 EXTENT_DELALLOC_NEW |
8980 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8981 EXTENT_DEFRAG, 1, 0, &cached_state,
8982 GFP_NOFS);
8983 /*
8984 * whoever cleared the private bit is responsible
8985 * for the finish_ordered_io
8986 */
8987 if (TestClearPagePrivate2(page)) {
8988 struct btrfs_ordered_inode_tree *tree;
8989 u64 new_len;
8990
8991 tree = &BTRFS_I(inode)->ordered_tree;
8992
8993 spin_lock_irq(&tree->lock);
8994 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8995 new_len = start - ordered->file_offset;
8996 if (new_len < ordered->truncated_len)
8997 ordered->truncated_len = new_len;
8998 spin_unlock_irq(&tree->lock);
8999
9000 if (btrfs_dec_test_ordered_pending(inode, &ordered,
9001 start,
9002 end - start + 1, 1))
9003 btrfs_finish_ordered_io(ordered);
9004 }
9005 btrfs_put_ordered_extent(ordered);
9006 if (!inode_evicting) {
9007 cached_state = NULL;
9008 lock_extent_bits(tree, start, end,
9009 &cached_state);
9010 }
9011
9012 start = end + 1;
9013 if (start < page_end)
9014 goto again;
9015 }
9016
9017 /*
9018 * Qgroup reserved space handler
9019 * Page here will be either
9020 * 1) Already written to disk
9021 * In this case, its reserved space is released from data rsv map
9022 * and will be freed by delayed_ref handler finally.
9023 * So even we call qgroup_free_data(), it won't decrease reserved
9024 * space.
9025 * 2) Not written to disk
9026 * This means the reserved space should be freed here. However,
9027 * if a truncate invalidates the page (by clearing PageDirty)
9028 * and the page is accounted for while allocating extent
9029 * in btrfs_check_data_free_space() we let delayed_ref to
9030 * free the entire extent.
9031 */
9032 if (PageDirty(page))
9033 btrfs_qgroup_free_data(inode, NULL, page_start, PAGE_SIZE);
9034 if (!inode_evicting) {
9035 clear_extent_bit(tree, page_start, page_end,
9036 EXTENT_LOCKED | EXTENT_DIRTY |
9037 EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
9038 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
9039 &cached_state, GFP_NOFS);
9040
9041 __btrfs_releasepage(page, GFP_NOFS);
9042 }
9043
9044 ClearPageChecked(page);
9045 if (PagePrivate(page)) {
9046 ClearPagePrivate(page);
9047 set_page_private(page, 0);
9048 put_page(page);
9049 }
9050}
9051
9052/*
9053 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
9054 * called from a page fault handler when a page is first dirtied. Hence we must
9055 * be careful to check for EOF conditions here. We set the page up correctly
9056 * for a written page which means we get ENOSPC checking when writing into
9057 * holes and correct delalloc and unwritten extent mapping on filesystems that
9058 * support these features.
9059 *
9060 * We are not allowed to take the i_mutex here so we have to play games to
9061 * protect against truncate races as the page could now be beyond EOF. Because
9062 * vmtruncate() writes the inode size before removing pages, once we have the
9063 * page lock we can determine safely if the page is beyond EOF. If it is not
9064 * beyond EOF, then the page is guaranteed safe against truncation until we
9065 * unlock the page.
9066 */
9067int btrfs_page_mkwrite(struct vm_fault *vmf)
9068{
9069 struct page *page = vmf->page;
9070 struct inode *inode = file_inode(vmf->vma->vm_file);
9071 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9072 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
9073 struct btrfs_ordered_extent *ordered;
9074 struct extent_state *cached_state = NULL;
9075 struct extent_changeset *data_reserved = NULL;
9076 char *kaddr;
9077 unsigned long zero_start;
9078 loff_t size;
9079 int ret;
9080 int reserved = 0;
9081 u64 reserved_space;
9082 u64 page_start;
9083 u64 page_end;
9084 u64 end;
9085
9086 reserved_space = PAGE_SIZE;
9087
9088 sb_start_pagefault(inode->i_sb);
9089 page_start = page_offset(page);
9090 page_end = page_start + PAGE_SIZE - 1;
9091 end = page_end;
9092
9093 /*
9094 * Reserving delalloc space after obtaining the page lock can lead to
9095 * deadlock. For example, if a dirty page is locked by this function
9096 * and the call to btrfs_delalloc_reserve_space() ends up triggering
9097 * dirty page write out, then the btrfs_writepage() function could
9098 * end up waiting indefinitely to get a lock on the page currently
9099 * being processed by btrfs_page_mkwrite() function.
9100 */
9101 ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
9102 reserved_space);
9103 if (!ret) {
9104 ret = file_update_time(vmf->vma->vm_file);
9105 reserved = 1;
9106 }
9107 if (ret) {
9108 if (ret == -ENOMEM)
9109 ret = VM_FAULT_OOM;
9110 else /* -ENOSPC, -EIO, etc */
9111 ret = VM_FAULT_SIGBUS;
9112 if (reserved)
9113 goto out;
9114 goto out_noreserve;
9115 }
9116
9117 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
9118again:
9119 lock_page(page);
9120 size = i_size_read(inode);
9121
9122 if ((page->mapping != inode->i_mapping) ||
9123 (page_start >= size)) {
9124 /* page got truncated out from underneath us */
9125 goto out_unlock;
9126 }
9127 wait_on_page_writeback(page);
9128
9129 lock_extent_bits(io_tree, page_start, page_end, &cached_state);
9130 set_page_extent_mapped(page);
9131
9132 /*
9133 * we can't set the delalloc bits if there are pending ordered
9134 * extents. Drop our locks and wait for them to finish
9135 */
9136 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
9137 PAGE_SIZE);
9138 if (ordered) {
9139 unlock_extent_cached(io_tree, page_start, page_end,
9140 &cached_state, GFP_NOFS);
9141 unlock_page(page);
9142 btrfs_start_ordered_extent(inode, ordered, 1);
9143 btrfs_put_ordered_extent(ordered);
9144 goto again;
9145 }
9146
9147 if (page->index == ((size - 1) >> PAGE_SHIFT)) {
9148 reserved_space = round_up(size - page_start,
9149 fs_info->sectorsize);
9150 if (reserved_space < PAGE_SIZE) {
9151 end = page_start + reserved_space - 1;
9152 btrfs_delalloc_release_space(inode, data_reserved,
9153 page_start, PAGE_SIZE - reserved_space);
9154 }
9155 }
9156
9157 /*
9158 * page_mkwrite gets called when the page is firstly dirtied after it's
9159 * faulted in, but write(2) could also dirty a page and set delalloc
9160 * bits, thus in this case for space account reason, we still need to
9161 * clear any delalloc bits within this page range since we have to
9162 * reserve data&meta space before lock_page() (see above comments).
9163 */
9164 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
9165 EXTENT_DIRTY | EXTENT_DELALLOC |
9166 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
9167 0, 0, &cached_state, GFP_NOFS);
9168
9169 ret = btrfs_set_extent_delalloc(inode, page_start, end, 0,
9170 &cached_state, 0);
9171 if (ret) {
9172 unlock_extent_cached(io_tree, page_start, page_end,
9173 &cached_state, GFP_NOFS);
9174 ret = VM_FAULT_SIGBUS;
9175 goto out_unlock;
9176 }
9177 ret = 0;
9178
9179 /* page is wholly or partially inside EOF */
9180 if (page_start + PAGE_SIZE > size)
9181 zero_start = size & ~PAGE_MASK;
9182 else
9183 zero_start = PAGE_SIZE;
9184
9185 if (zero_start != PAGE_SIZE) {
9186 kaddr = kmap(page);
9187 memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start);
9188 flush_dcache_page(page);
9189 kunmap(page);
9190 }
9191 ClearPageChecked(page);
9192 set_page_dirty(page);
9193 SetPageUptodate(page);
9194
9195 BTRFS_I(inode)->last_trans = fs_info->generation;
9196 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
9197 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
9198
9199 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
9200
9201out_unlock:
9202 if (!ret) {
9203 btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
9204 sb_end_pagefault(inode->i_sb);
9205 extent_changeset_free(data_reserved);
9206 return VM_FAULT_LOCKED;
9207 }
9208 unlock_page(page);
9209out:
9210 btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
9211 btrfs_delalloc_release_space(inode, data_reserved, page_start,
9212 reserved_space);
9213out_noreserve:
9214 sb_end_pagefault(inode->i_sb);
9215 extent_changeset_free(data_reserved);
9216 return ret;
9217}
9218
9219static int btrfs_truncate(struct inode *inode)
9220{
9221 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9222 struct btrfs_root *root = BTRFS_I(inode)->root;
9223 struct btrfs_block_rsv *rsv;
9224 int ret = 0;
9225 int err = 0;
9226 struct btrfs_trans_handle *trans;
9227 u64 mask = fs_info->sectorsize - 1;
9228 u64 min_size = btrfs_calc_trunc_metadata_size(fs_info, 1);
9229
9230 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
9231 (u64)-1);
9232 if (ret)
9233 return ret;
9234
9235 /*
9236 * Yes ladies and gentlemen, this is indeed ugly. The fact is we have
9237 * 3 things going on here
9238 *
9239 * 1) We need to reserve space for our orphan item and the space to
9240 * delete our orphan item. Lord knows we don't want to have a dangling
9241 * orphan item because we didn't reserve space to remove it.
9242 *
9243 * 2) We need to reserve space to update our inode.
9244 *
9245 * 3) We need to have something to cache all the space that is going to
9246 * be free'd up by the truncate operation, but also have some slack
9247 * space reserved in case it uses space during the truncate (thank you
9248 * very much snapshotting).
9249 *
9250 * And we need these to all be separate. The fact is we can use a lot of
9251 * space doing the truncate, and we have no earthly idea how much space
9252 * we will use, so we need the truncate reservation to be separate so it
9253 * doesn't end up using space reserved for updating the inode or
9254 * removing the orphan item. We also need to be able to stop the
9255 * transaction and start a new one, which means we need to be able to
9256 * update the inode several times, and we have no idea of knowing how
9257 * many times that will be, so we can't just reserve 1 item for the
9258 * entirety of the operation, so that has to be done separately as well.
9259 * Then there is the orphan item, which does indeed need to be held on
9260 * to for the whole operation, and we need nobody to touch this reserved
9261 * space except the orphan code.
9262 *
9263 * So that leaves us with
9264 *
9265 * 1) root->orphan_block_rsv - for the orphan deletion.
9266 * 2) rsv - for the truncate reservation, which we will steal from the
9267 * transaction reservation.
9268 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
9269 * updating the inode.
9270 */
9271 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
9272 if (!rsv)
9273 return -ENOMEM;
9274 rsv->size = min_size;
9275 rsv->failfast = 1;
9276
9277 /*
9278 * 1 for the truncate slack space
9279 * 1 for updating the inode.
9280 */
9281 trans = btrfs_start_transaction(root, 2);
9282 if (IS_ERR(trans)) {
9283 err = PTR_ERR(trans);
9284 goto out;
9285 }
9286
9287 /* Migrate the slack space for the truncate to our reserve */
9288 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
9289 min_size, 0);
9290 BUG_ON(ret);
9291
9292 /*
9293 * So if we truncate and then write and fsync we normally would just
9294 * write the extents that changed, which is a problem if we need to
9295 * first truncate that entire inode. So set this flag so we write out
9296 * all of the extents in the inode to the sync log so we're completely
9297 * safe.
9298 */
9299 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
9300 trans->block_rsv = rsv;
9301
9302 while (1) {
9303 ret = btrfs_truncate_inode_items(trans, root, inode,
9304 inode->i_size,
9305 BTRFS_EXTENT_DATA_KEY);
9306 trans->block_rsv = &fs_info->trans_block_rsv;
9307 if (ret != -ENOSPC && ret != -EAGAIN) {
9308 err = ret;
9309 break;
9310 }
9311
9312 ret = btrfs_update_inode(trans, root, inode);
9313 if (ret) {
9314 err = ret;
9315 break;
9316 }
9317
9318 btrfs_end_transaction(trans);
9319 btrfs_btree_balance_dirty(fs_info);
9320
9321 trans = btrfs_start_transaction(root, 2);
9322 if (IS_ERR(trans)) {
9323 ret = err = PTR_ERR(trans);
9324 trans = NULL;
9325 break;
9326 }
9327
9328 btrfs_block_rsv_release(fs_info, rsv, -1);
9329 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
9330 rsv, min_size, 0);
9331 BUG_ON(ret); /* shouldn't happen */
9332 trans->block_rsv = rsv;
9333 }
9334
9335 /*
9336 * We can't call btrfs_truncate_block inside a trans handle as we could
9337 * deadlock with freeze, if we got NEED_TRUNCATE_BLOCK then we know
9338 * we've truncated everything except the last little bit, and can do
9339 * btrfs_truncate_block and then update the disk_i_size.
9340 */
9341 if (ret == NEED_TRUNCATE_BLOCK) {
9342 btrfs_end_transaction(trans);
9343 btrfs_btree_balance_dirty(fs_info);
9344
9345 ret = btrfs_truncate_block(inode, inode->i_size, 0, 0);
9346 if (ret)
9347 goto out;
9348 trans = btrfs_start_transaction(root, 1);
9349 if (IS_ERR(trans)) {
9350 ret = PTR_ERR(trans);
9351 goto out;
9352 }
9353 btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
9354 }
9355
9356 if (ret == 0 && inode->i_nlink > 0) {
9357 trans->block_rsv = root->orphan_block_rsv;
9358 ret = btrfs_orphan_del(trans, BTRFS_I(inode));
9359 if (ret)
9360 err = ret;
9361 }
9362
9363 if (trans) {
9364 trans->block_rsv = &fs_info->trans_block_rsv;
9365 ret = btrfs_update_inode(trans, root, inode);
9366 if (ret && !err)
9367 err = ret;
9368
9369 ret = btrfs_end_transaction(trans);
9370 btrfs_btree_balance_dirty(fs_info);
9371 }
9372out:
9373 btrfs_free_block_rsv(fs_info, rsv);
9374
9375 if (ret && !err)
9376 err = ret;
9377
9378 return err;
9379}
9380
9381/*
9382 * create a new subvolume directory/inode (helper for the ioctl).
9383 */
9384int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
9385 struct btrfs_root *new_root,
9386 struct btrfs_root *parent_root,
9387 u64 new_dirid)
9388{
9389 struct inode *inode;
9390 int err;
9391 u64 index = 0;
9392
9393 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
9394 new_dirid, new_dirid,
9395 S_IFDIR | (~current_umask() & S_IRWXUGO),
9396 &index);
9397 if (IS_ERR(inode))
9398 return PTR_ERR(inode);
9399 inode->i_op = &btrfs_dir_inode_operations;
9400 inode->i_fop = &btrfs_dir_file_operations;
9401
9402 set_nlink(inode, 1);
9403 btrfs_i_size_write(BTRFS_I(inode), 0);
9404 unlock_new_inode(inode);
9405
9406 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
9407 if (err)
9408 btrfs_err(new_root->fs_info,
9409 "error inheriting subvolume %llu properties: %d",
9410 new_root->root_key.objectid, err);
9411
9412 err = btrfs_update_inode(trans, new_root, inode);
9413
9414 iput(inode);
9415 return err;
9416}
9417
9418struct inode *btrfs_alloc_inode(struct super_block *sb)
9419{
9420 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
9421 struct btrfs_inode *ei;
9422 struct inode *inode;
9423
9424 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
9425 if (!ei)
9426 return NULL;
9427
9428 ei->root = NULL;
9429 ei->generation = 0;
9430 ei->last_trans = 0;
9431 ei->last_sub_trans = 0;
9432 ei->logged_trans = 0;
9433 ei->delalloc_bytes = 0;
9434 ei->new_delalloc_bytes = 0;
9435 ei->defrag_bytes = 0;
9436 ei->disk_i_size = 0;
9437 ei->flags = 0;
9438 ei->csum_bytes = 0;
9439 ei->index_cnt = (u64)-1;
9440 ei->dir_index = 0;
9441 ei->last_unlink_trans = 0;
9442 ei->last_log_commit = 0;
9443 ei->delayed_iput_count = 0;
9444
9445 spin_lock_init(&ei->lock);
9446 ei->outstanding_extents = 0;
9447 if (sb->s_magic != BTRFS_TEST_MAGIC)
9448 btrfs_init_metadata_block_rsv(fs_info, &ei->block_rsv,
9449 BTRFS_BLOCK_RSV_DELALLOC);
9450 ei->runtime_flags = 0;
9451 ei->prop_compress = BTRFS_COMPRESS_NONE;
9452 ei->defrag_compress = BTRFS_COMPRESS_NONE;
9453
9454 ei->delayed_node = NULL;
9455
9456 ei->i_otime.tv_sec = 0;
9457 ei->i_otime.tv_nsec = 0;
9458
9459 inode = &ei->vfs_inode;
9460 extent_map_tree_init(&ei->extent_tree);
9461 extent_io_tree_init(&ei->io_tree, inode);
9462 extent_io_tree_init(&ei->io_failure_tree, inode);
9463 ei->io_tree.track_uptodate = 1;
9464 ei->io_failure_tree.track_uptodate = 1;
9465 atomic_set(&ei->sync_writers, 0);
9466 mutex_init(&ei->log_mutex);
9467 mutex_init(&ei->delalloc_mutex);
9468 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
9469 INIT_LIST_HEAD(&ei->delalloc_inodes);
9470 INIT_LIST_HEAD(&ei->delayed_iput);
9471 RB_CLEAR_NODE(&ei->rb_node);
9472 init_rwsem(&ei->dio_sem);
9473
9474 return inode;
9475}
9476
9477#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
9478void btrfs_test_destroy_inode(struct inode *inode)
9479{
9480 btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
9481 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9482}
9483#endif
9484
9485static void btrfs_i_callback(struct rcu_head *head)
9486{
9487 struct inode *inode = container_of(head, struct inode, i_rcu);
9488 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9489}
9490
9491void btrfs_destroy_inode(struct inode *inode)
9492{
9493 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9494 struct btrfs_ordered_extent *ordered;
9495 struct btrfs_root *root = BTRFS_I(inode)->root;
9496
9497 WARN_ON(!hlist_empty(&inode->i_dentry));
9498 WARN_ON(inode->i_data.nrpages);
9499 WARN_ON(BTRFS_I(inode)->block_rsv.reserved);
9500 WARN_ON(BTRFS_I(inode)->block_rsv.size);
9501 WARN_ON(BTRFS_I(inode)->outstanding_extents);
9502 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
9503 WARN_ON(BTRFS_I(inode)->new_delalloc_bytes);
9504 WARN_ON(BTRFS_I(inode)->csum_bytes);
9505 WARN_ON(BTRFS_I(inode)->defrag_bytes);
9506
9507 /*
9508 * This can happen where we create an inode, but somebody else also
9509 * created the same inode and we need to destroy the one we already
9510 * created.
9511 */
9512 if (!root)
9513 goto free;
9514
9515 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
9516 &BTRFS_I(inode)->runtime_flags)) {
9517 btrfs_info(fs_info, "inode %llu still on the orphan list",
9518 btrfs_ino(BTRFS_I(inode)));
9519 atomic_dec(&root->orphan_inodes);
9520 }
9521
9522 while (1) {
9523 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
9524 if (!ordered)
9525 break;
9526 else {
9527 btrfs_err(fs_info,
9528 "found ordered extent %llu %llu on inode cleanup",
9529 ordered->file_offset, ordered->len);
9530 btrfs_remove_ordered_extent(inode, ordered);
9531 btrfs_put_ordered_extent(ordered);
9532 btrfs_put_ordered_extent(ordered);
9533 }
9534 }
9535 btrfs_qgroup_check_reserved_leak(inode);
9536 inode_tree_del(inode);
9537 btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
9538free:
9539 call_rcu(&inode->i_rcu, btrfs_i_callback);
9540}
9541
9542int btrfs_drop_inode(struct inode *inode)
9543{
9544 struct btrfs_root *root = BTRFS_I(inode)->root;
9545
9546 if (root == NULL)
9547 return 1;
9548
9549 /* the snap/subvol tree is on deleting */
9550 if (btrfs_root_refs(&root->root_item) == 0)
9551 return 1;
9552 else
9553 return generic_drop_inode(inode);
9554}
9555
9556static void init_once(void *foo)
9557{
9558 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
9559
9560 inode_init_once(&ei->vfs_inode);
9561}
9562
9563void btrfs_destroy_cachep(void)
9564{
9565 /*
9566 * Make sure all delayed rcu free inodes are flushed before we
9567 * destroy cache.
9568 */
9569 rcu_barrier();
9570 kmem_cache_destroy(btrfs_inode_cachep);
9571 kmem_cache_destroy(btrfs_trans_handle_cachep);
9572 kmem_cache_destroy(btrfs_path_cachep);
9573 kmem_cache_destroy(btrfs_free_space_cachep);
9574}
9575
9576int btrfs_init_cachep(void)
9577{
9578 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
9579 sizeof(struct btrfs_inode), 0,
9580 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
9581 init_once);
9582 if (!btrfs_inode_cachep)
9583 goto fail;
9584
9585 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
9586 sizeof(struct btrfs_trans_handle), 0,
9587 SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
9588 if (!btrfs_trans_handle_cachep)
9589 goto fail;
9590
9591 btrfs_path_cachep = kmem_cache_create("btrfs_path",
9592 sizeof(struct btrfs_path), 0,
9593 SLAB_MEM_SPREAD, NULL);
9594 if (!btrfs_path_cachep)
9595 goto fail;
9596
9597 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
9598 sizeof(struct btrfs_free_space), 0,
9599 SLAB_MEM_SPREAD, NULL);
9600 if (!btrfs_free_space_cachep)
9601 goto fail;
9602
9603 return 0;
9604fail:
9605 btrfs_destroy_cachep();
9606 return -ENOMEM;
9607}
9608
9609static int btrfs_getattr(const struct path *path, struct kstat *stat,
9610 u32 request_mask, unsigned int flags)
9611{
9612 u64 delalloc_bytes;
9613 struct inode *inode = d_inode(path->dentry);
9614 u32 blocksize = inode->i_sb->s_blocksize;
9615 u32 bi_flags = BTRFS_I(inode)->flags;
9616
9617 stat->result_mask |= STATX_BTIME;
9618 stat->btime.tv_sec = BTRFS_I(inode)->i_otime.tv_sec;
9619 stat->btime.tv_nsec = BTRFS_I(inode)->i_otime.tv_nsec;
9620 if (bi_flags & BTRFS_INODE_APPEND)
9621 stat->attributes |= STATX_ATTR_APPEND;
9622 if (bi_flags & BTRFS_INODE_COMPRESS)
9623 stat->attributes |= STATX_ATTR_COMPRESSED;
9624 if (bi_flags & BTRFS_INODE_IMMUTABLE)
9625 stat->attributes |= STATX_ATTR_IMMUTABLE;
9626 if (bi_flags & BTRFS_INODE_NODUMP)
9627 stat->attributes |= STATX_ATTR_NODUMP;
9628
9629 stat->attributes_mask |= (STATX_ATTR_APPEND |
9630 STATX_ATTR_COMPRESSED |
9631 STATX_ATTR_IMMUTABLE |
9632 STATX_ATTR_NODUMP);
9633
9634 generic_fillattr(inode, stat);
9635 stat->dev = BTRFS_I(inode)->root->anon_dev;
9636
9637 spin_lock(&BTRFS_I(inode)->lock);
9638 delalloc_bytes = BTRFS_I(inode)->new_delalloc_bytes;
9639 spin_unlock(&BTRFS_I(inode)->lock);
9640 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9641 ALIGN(delalloc_bytes, blocksize)) >> 9;
9642 return 0;
9643}
9644
9645static int btrfs_rename_exchange(struct inode *old_dir,
9646 struct dentry *old_dentry,
9647 struct inode *new_dir,
9648 struct dentry *new_dentry)
9649{
9650 struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9651 struct btrfs_trans_handle *trans;
9652 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9653 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9654 struct inode *new_inode = new_dentry->d_inode;
9655 struct inode *old_inode = old_dentry->d_inode;
9656 struct timespec ctime = current_time(old_inode);
9657 struct dentry *parent;
9658 u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
9659 u64 new_ino = btrfs_ino(BTRFS_I(new_inode));
9660 u64 old_idx = 0;
9661 u64 new_idx = 0;
9662 u64 root_objectid;
9663 int ret;
9664 bool root_log_pinned = false;
9665 bool dest_log_pinned = false;
9666
9667 /* we only allow rename subvolume link between subvolumes */
9668 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9669 return -EXDEV;
9670
9671 /* close the race window with snapshot create/destroy ioctl */
9672 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9673 down_read(&fs_info->subvol_sem);
9674 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9675 down_read(&fs_info->subvol_sem);
9676
9677 /*
9678 * We want to reserve the absolute worst case amount of items. So if
9679 * both inodes are subvols and we need to unlink them then that would
9680 * require 4 item modifications, but if they are both normal inodes it
9681 * would require 5 item modifications, so we'll assume their normal
9682 * inodes. So 5 * 2 is 10, plus 2 for the new links, so 12 total items
9683 * should cover the worst case number of items we'll modify.
9684 */
9685 trans = btrfs_start_transaction(root, 12);
9686 if (IS_ERR(trans)) {
9687 ret = PTR_ERR(trans);
9688 goto out_notrans;
9689 }
9690
9691 /*
9692 * We need to find a free sequence number both in the source and
9693 * in the destination directory for the exchange.
9694 */
9695 ret = btrfs_set_inode_index(BTRFS_I(new_dir), &old_idx);
9696 if (ret)
9697 goto out_fail;
9698 ret = btrfs_set_inode_index(BTRFS_I(old_dir), &new_idx);
9699 if (ret)
9700 goto out_fail;
9701
9702 BTRFS_I(old_inode)->dir_index = 0ULL;
9703 BTRFS_I(new_inode)->dir_index = 0ULL;
9704
9705 /* Reference for the source. */
9706 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9707 /* force full log commit if subvolume involved. */
9708 btrfs_set_log_full_commit(fs_info, trans);
9709 } else {
9710 btrfs_pin_log_trans(root);
9711 root_log_pinned = true;
9712 ret = btrfs_insert_inode_ref(trans, dest,
9713 new_dentry->d_name.name,
9714 new_dentry->d_name.len,
9715 old_ino,
9716 btrfs_ino(BTRFS_I(new_dir)),
9717 old_idx);
9718 if (ret)
9719 goto out_fail;
9720 }
9721
9722 /* And now for the dest. */
9723 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9724 /* force full log commit if subvolume involved. */
9725 btrfs_set_log_full_commit(fs_info, trans);
9726 } else {
9727 btrfs_pin_log_trans(dest);
9728 dest_log_pinned = true;
9729 ret = btrfs_insert_inode_ref(trans, root,
9730 old_dentry->d_name.name,
9731 old_dentry->d_name.len,
9732 new_ino,
9733 btrfs_ino(BTRFS_I(old_dir)),
9734 new_idx);
9735 if (ret)
9736 goto out_fail;
9737 }
9738
9739 /* Update inode version and ctime/mtime. */
9740 inode_inc_iversion(old_dir);
9741 inode_inc_iversion(new_dir);
9742 inode_inc_iversion(old_inode);
9743 inode_inc_iversion(new_inode);
9744 old_dir->i_ctime = old_dir->i_mtime = ctime;
9745 new_dir->i_ctime = new_dir->i_mtime = ctime;
9746 old_inode->i_ctime = ctime;
9747 new_inode->i_ctime = ctime;
9748
9749 if (old_dentry->d_parent != new_dentry->d_parent) {
9750 btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
9751 BTRFS_I(old_inode), 1);
9752 btrfs_record_unlink_dir(trans, BTRFS_I(new_dir),
9753 BTRFS_I(new_inode), 1);
9754 }
9755
9756 /* src is a subvolume */
9757 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9758 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9759 ret = btrfs_unlink_subvol(trans, root, old_dir,
9760 root_objectid,
9761 old_dentry->d_name.name,
9762 old_dentry->d_name.len);
9763 } else { /* src is an inode */
9764 ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
9765 BTRFS_I(old_dentry->d_inode),
9766 old_dentry->d_name.name,
9767 old_dentry->d_name.len);
9768 if (!ret)
9769 ret = btrfs_update_inode(trans, root, old_inode);
9770 }
9771 if (ret) {
9772 btrfs_abort_transaction(trans, ret);
9773 goto out_fail;
9774 }
9775
9776 /* dest is a subvolume */
9777 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9778 root_objectid = BTRFS_I(new_inode)->root->root_key.objectid;
9779 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9780 root_objectid,
9781 new_dentry->d_name.name,
9782 new_dentry->d_name.len);
9783 } else { /* dest is an inode */
9784 ret = __btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
9785 BTRFS_I(new_dentry->d_inode),
9786 new_dentry->d_name.name,
9787 new_dentry->d_name.len);
9788 if (!ret)
9789 ret = btrfs_update_inode(trans, dest, new_inode);
9790 }
9791 if (ret) {
9792 btrfs_abort_transaction(trans, ret);
9793 goto out_fail;
9794 }
9795
9796 ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
9797 new_dentry->d_name.name,
9798 new_dentry->d_name.len, 0, old_idx);
9799 if (ret) {
9800 btrfs_abort_transaction(trans, ret);
9801 goto out_fail;
9802 }
9803
9804 ret = btrfs_add_link(trans, BTRFS_I(old_dir), BTRFS_I(new_inode),
9805 old_dentry->d_name.name,
9806 old_dentry->d_name.len, 0, new_idx);
9807 if (ret) {
9808 btrfs_abort_transaction(trans, ret);
9809 goto out_fail;
9810 }
9811
9812 if (old_inode->i_nlink == 1)
9813 BTRFS_I(old_inode)->dir_index = old_idx;
9814 if (new_inode->i_nlink == 1)
9815 BTRFS_I(new_inode)->dir_index = new_idx;
9816
9817 if (root_log_pinned) {
9818 parent = new_dentry->d_parent;
9819 btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir),
9820 parent);
9821 btrfs_end_log_trans(root);
9822 root_log_pinned = false;
9823 }
9824 if (dest_log_pinned) {
9825 parent = old_dentry->d_parent;
9826 btrfs_log_new_name(trans, BTRFS_I(new_inode), BTRFS_I(new_dir),
9827 parent);
9828 btrfs_end_log_trans(dest);
9829 dest_log_pinned = false;
9830 }
9831out_fail:
9832 /*
9833 * If we have pinned a log and an error happened, we unpin tasks
9834 * trying to sync the log and force them to fallback to a transaction
9835 * commit if the log currently contains any of the inodes involved in
9836 * this rename operation (to ensure we do not persist a log with an
9837 * inconsistent state for any of these inodes or leading to any
9838 * inconsistencies when replayed). If the transaction was aborted, the
9839 * abortion reason is propagated to userspace when attempting to commit
9840 * the transaction. If the log does not contain any of these inodes, we
9841 * allow the tasks to sync it.
9842 */
9843 if (ret && (root_log_pinned || dest_log_pinned)) {
9844 if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
9845 btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
9846 btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
9847 (new_inode &&
9848 btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
9849 btrfs_set_log_full_commit(fs_info, trans);
9850
9851 if (root_log_pinned) {
9852 btrfs_end_log_trans(root);
9853 root_log_pinned = false;
9854 }
9855 if (dest_log_pinned) {
9856 btrfs_end_log_trans(dest);
9857 dest_log_pinned = false;
9858 }
9859 }
9860 ret = btrfs_end_transaction(trans);
9861out_notrans:
9862 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9863 up_read(&fs_info->subvol_sem);
9864 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9865 up_read(&fs_info->subvol_sem);
9866
9867 return ret;
9868}
9869
9870static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans,
9871 struct btrfs_root *root,
9872 struct inode *dir,
9873 struct dentry *dentry)
9874{
9875 int ret;
9876 struct inode *inode;
9877 u64 objectid;
9878 u64 index;
9879
9880 ret = btrfs_find_free_ino(root, &objectid);
9881 if (ret)
9882 return ret;
9883
9884 inode = btrfs_new_inode(trans, root, dir,
9885 dentry->d_name.name,
9886 dentry->d_name.len,
9887 btrfs_ino(BTRFS_I(dir)),
9888 objectid,
9889 S_IFCHR | WHITEOUT_MODE,
9890 &index);
9891
9892 if (IS_ERR(inode)) {
9893 ret = PTR_ERR(inode);
9894 return ret;
9895 }
9896
9897 inode->i_op = &btrfs_special_inode_operations;
9898 init_special_inode(inode, inode->i_mode,
9899 WHITEOUT_DEV);
9900
9901 ret = btrfs_init_inode_security(trans, inode, dir,
9902 &dentry->d_name);
9903 if (ret)
9904 goto out;
9905
9906 ret = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
9907 BTRFS_I(inode), 0, index);
9908 if (ret)
9909 goto out;
9910
9911 ret = btrfs_update_inode(trans, root, inode);
9912out:
9913 unlock_new_inode(inode);
9914 if (ret)
9915 inode_dec_link_count(inode);
9916 iput(inode);
9917
9918 return ret;
9919}
9920
9921static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9922 struct inode *new_dir, struct dentry *new_dentry,
9923 unsigned int flags)
9924{
9925 struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9926 struct btrfs_trans_handle *trans;
9927 unsigned int trans_num_items;
9928 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9929 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9930 struct inode *new_inode = d_inode(new_dentry);
9931 struct inode *old_inode = d_inode(old_dentry);
9932 u64 index = 0;
9933 u64 root_objectid;
9934 int ret;
9935 u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
9936 bool log_pinned = false;
9937
9938 if (btrfs_ino(BTRFS_I(new_dir)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9939 return -EPERM;
9940
9941 /* we only allow rename subvolume link between subvolumes */
9942 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9943 return -EXDEV;
9944
9945 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9946 (new_inode && btrfs_ino(BTRFS_I(new_inode)) == BTRFS_FIRST_FREE_OBJECTID))
9947 return -ENOTEMPTY;
9948
9949 if (S_ISDIR(old_inode->i_mode) && new_inode &&
9950 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9951 return -ENOTEMPTY;
9952
9953
9954 /* check for collisions, even if the name isn't there */
9955 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9956 new_dentry->d_name.name,
9957 new_dentry->d_name.len);
9958
9959 if (ret) {
9960 if (ret == -EEXIST) {
9961 /* we shouldn't get
9962 * eexist without a new_inode */
9963 if (WARN_ON(!new_inode)) {
9964 return ret;
9965 }
9966 } else {
9967 /* maybe -EOVERFLOW */
9968 return ret;
9969 }
9970 }
9971 ret = 0;
9972
9973 /*
9974 * we're using rename to replace one file with another. Start IO on it
9975 * now so we don't add too much work to the end of the transaction
9976 */
9977 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9978 filemap_flush(old_inode->i_mapping);
9979
9980 /* close the racy window with snapshot create/destroy ioctl */
9981 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9982 down_read(&fs_info->subvol_sem);
9983 /*
9984 * We want to reserve the absolute worst case amount of items. So if
9985 * both inodes are subvols and we need to unlink them then that would
9986 * require 4 item modifications, but if they are both normal inodes it
9987 * would require 5 item modifications, so we'll assume they are normal
9988 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
9989 * should cover the worst case number of items we'll modify.
9990 * If our rename has the whiteout flag, we need more 5 units for the
9991 * new inode (1 inode item, 1 inode ref, 2 dir items and 1 xattr item
9992 * when selinux is enabled).
9993 */
9994 trans_num_items = 11;
9995 if (flags & RENAME_WHITEOUT)
9996 trans_num_items += 5;
9997 trans = btrfs_start_transaction(root, trans_num_items);
9998 if (IS_ERR(trans)) {
9999 ret = PTR_ERR(trans);
10000 goto out_notrans;
10001 }
10002
10003 if (dest != root)
10004 btrfs_record_root_in_trans(trans, dest);
10005
10006 ret = btrfs_set_inode_index(BTRFS_I(new_dir), &index);
10007 if (ret)
10008 goto out_fail;
10009
10010 BTRFS_I(old_inode)->dir_index = 0ULL;
10011 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
10012 /* force full log commit if subvolume involved. */
10013 btrfs_set_log_full_commit(fs_info, trans);
10014 } else {
10015 btrfs_pin_log_trans(root);
10016 log_pinned = true;
10017 ret = btrfs_insert_inode_ref(trans, dest,
10018 new_dentry->d_name.name,
10019 new_dentry->d_name.len,
10020 old_ino,
10021 btrfs_ino(BTRFS_I(new_dir)), index);
10022 if (ret)
10023 goto out_fail;
10024 }
10025
10026 inode_inc_iversion(old_dir);
10027 inode_inc_iversion(new_dir);
10028 inode_inc_iversion(old_inode);
10029 old_dir->i_ctime = old_dir->i_mtime =
10030 new_dir->i_ctime = new_dir->i_mtime =
10031 old_inode->i_ctime = current_time(old_dir);
10032
10033 if (old_dentry->d_parent != new_dentry->d_parent)
10034 btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
10035 BTRFS_I(old_inode), 1);
10036
10037 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
10038 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
10039 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
10040 old_dentry->d_name.name,
10041 old_dentry->d_name.len);
10042 } else {
10043 ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
10044 BTRFS_I(d_inode(old_dentry)),
10045 old_dentry->d_name.name,
10046 old_dentry->d_name.len);
10047 if (!ret)
10048 ret = btrfs_update_inode(trans, root, old_inode);
10049 }
10050 if (ret) {
10051 btrfs_abort_transaction(trans, ret);
10052 goto out_fail;
10053 }
10054
10055 if (new_inode) {
10056 inode_inc_iversion(new_inode);
10057 new_inode->i_ctime = current_time(new_inode);
10058 if (unlikely(btrfs_ino(BTRFS_I(new_inode)) ==
10059 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
10060 root_objectid = BTRFS_I(new_inode)->location.objectid;
10061 ret = btrfs_unlink_subvol(trans, dest, new_dir,
10062 root_objectid,
10063 new_dentry->d_name.name,
10064 new_dentry->d_name.len);
10065 BUG_ON(new_inode->i_nlink == 0);
10066 } else {
10067 ret = btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
10068 BTRFS_I(d_inode(new_dentry)),
10069 new_dentry->d_name.name,
10070 new_dentry->d_name.len);
10071 }
10072 if (!ret && new_inode->i_nlink == 0)
10073 ret = btrfs_orphan_add(trans,
10074 BTRFS_I(d_inode(new_dentry)));
10075 if (ret) {
10076 btrfs_abort_transaction(trans, ret);
10077 goto out_fail;
10078 }
10079 }
10080
10081 ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
10082 new_dentry->d_name.name,
10083 new_dentry->d_name.len, 0, index);
10084 if (ret) {
10085 btrfs_abort_transaction(trans, ret);
10086 goto out_fail;
10087 }
10088
10089 if (old_inode->i_nlink == 1)
10090 BTRFS_I(old_inode)->dir_index = index;
10091
10092 if (log_pinned) {
10093 struct dentry *parent = new_dentry->d_parent;
10094
10095 btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir),
10096 parent);
10097 btrfs_end_log_trans(root);
10098 log_pinned = false;
10099 }
10100
10101 if (flags & RENAME_WHITEOUT) {
10102 ret = btrfs_whiteout_for_rename(trans, root, old_dir,
10103 old_dentry);
10104
10105 if (ret) {
10106 btrfs_abort_transaction(trans, ret);
10107 goto out_fail;
10108 }
10109 }
10110out_fail:
10111 /*
10112 * If we have pinned the log and an error happened, we unpin tasks
10113 * trying to sync the log and force them to fallback to a transaction
10114 * commit if the log currently contains any of the inodes involved in
10115 * this rename operation (to ensure we do not persist a log with an
10116 * inconsistent state for any of these inodes or leading to any
10117 * inconsistencies when replayed). If the transaction was aborted, the
10118 * abortion reason is propagated to userspace when attempting to commit
10119 * the transaction. If the log does not contain any of these inodes, we
10120 * allow the tasks to sync it.
10121 */
10122 if (ret && log_pinned) {
10123 if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
10124 btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
10125 btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
10126 (new_inode &&
10127 btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
10128 btrfs_set_log_full_commit(fs_info, trans);
10129
10130 btrfs_end_log_trans(root);
10131 log_pinned = false;
10132 }
10133 btrfs_end_transaction(trans);
10134out_notrans:
10135 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
10136 up_read(&fs_info->subvol_sem);
10137
10138 return ret;
10139}
10140
10141static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
10142 struct inode *new_dir, struct dentry *new_dentry,
10143 unsigned int flags)
10144{
10145 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
10146 return -EINVAL;
10147
10148 if (flags & RENAME_EXCHANGE)
10149 return btrfs_rename_exchange(old_dir, old_dentry, new_dir,
10150 new_dentry);
10151
10152 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
10153}
10154
10155static void btrfs_run_delalloc_work(struct btrfs_work *work)
10156{
10157 struct btrfs_delalloc_work *delalloc_work;
10158 struct inode *inode;
10159
10160 delalloc_work = container_of(work, struct btrfs_delalloc_work,
10161 work);
10162 inode = delalloc_work->inode;
10163 filemap_flush(inode->i_mapping);
10164 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
10165 &BTRFS_I(inode)->runtime_flags))
10166 filemap_flush(inode->i_mapping);
10167
10168 if (delalloc_work->delay_iput)
10169 btrfs_add_delayed_iput(inode);
10170 else
10171 iput(inode);
10172 complete(&delalloc_work->completion);
10173}
10174
10175struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
10176 int delay_iput)
10177{
10178 struct btrfs_delalloc_work *work;
10179
10180 work = kmalloc(sizeof(*work), GFP_NOFS);
10181 if (!work)
10182 return NULL;
10183
10184 init_completion(&work->completion);
10185 INIT_LIST_HEAD(&work->list);
10186 work->inode = inode;
10187 work->delay_iput = delay_iput;
10188 WARN_ON_ONCE(!inode);
10189 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
10190 btrfs_run_delalloc_work, NULL, NULL);
10191
10192 return work;
10193}
10194
10195void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
10196{
10197 wait_for_completion(&work->completion);
10198 kfree(work);
10199}
10200
10201/*
10202 * some fairly slow code that needs optimization. This walks the list
10203 * of all the inodes with pending delalloc and forces them to disk.
10204 */
10205static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
10206 int nr)
10207{
10208 struct btrfs_inode *binode;
10209 struct inode *inode;
10210 struct btrfs_delalloc_work *work, *next;
10211 struct list_head works;
10212 struct list_head splice;
10213 int ret = 0;
10214
10215 INIT_LIST_HEAD(&works);
10216 INIT_LIST_HEAD(&splice);
10217
10218 mutex_lock(&root->delalloc_mutex);
10219 spin_lock(&root->delalloc_lock);
10220 list_splice_init(&root->delalloc_inodes, &splice);
10221 while (!list_empty(&splice)) {
10222 binode = list_entry(splice.next, struct btrfs_inode,
10223 delalloc_inodes);
10224
10225 list_move_tail(&binode->delalloc_inodes,
10226 &root->delalloc_inodes);
10227 inode = igrab(&binode->vfs_inode);
10228 if (!inode) {
10229 cond_resched_lock(&root->delalloc_lock);
10230 continue;
10231 }
10232 spin_unlock(&root->delalloc_lock);
10233
10234 work = btrfs_alloc_delalloc_work(inode, delay_iput);
10235 if (!work) {
10236 if (delay_iput)
10237 btrfs_add_delayed_iput(inode);
10238 else
10239 iput(inode);
10240 ret = -ENOMEM;
10241 goto out;
10242 }
10243 list_add_tail(&work->list, &works);
10244 btrfs_queue_work(root->fs_info->flush_workers,
10245 &work->work);
10246 ret++;
10247 if (nr != -1 && ret >= nr)
10248 goto out;
10249 cond_resched();
10250 spin_lock(&root->delalloc_lock);
10251 }
10252 spin_unlock(&root->delalloc_lock);
10253
10254out:
10255 list_for_each_entry_safe(work, next, &works, list) {
10256 list_del_init(&work->list);
10257 btrfs_wait_and_free_delalloc_work(work);
10258 }
10259
10260 if (!list_empty_careful(&splice)) {
10261 spin_lock(&root->delalloc_lock);
10262 list_splice_tail(&splice, &root->delalloc_inodes);
10263 spin_unlock(&root->delalloc_lock);
10264 }
10265 mutex_unlock(&root->delalloc_mutex);
10266 return ret;
10267}
10268
10269int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
10270{
10271 struct btrfs_fs_info *fs_info = root->fs_info;
10272 int ret;
10273
10274 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10275 return -EROFS;
10276
10277 ret = __start_delalloc_inodes(root, delay_iput, -1);
10278 if (ret > 0)
10279 ret = 0;
10280 return ret;
10281}
10282
10283int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
10284 int nr)
10285{
10286 struct btrfs_root *root;
10287 struct list_head splice;
10288 int ret;
10289
10290 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10291 return -EROFS;
10292
10293 INIT_LIST_HEAD(&splice);
10294
10295 mutex_lock(&fs_info->delalloc_root_mutex);
10296 spin_lock(&fs_info->delalloc_root_lock);
10297 list_splice_init(&fs_info->delalloc_roots, &splice);
10298 while (!list_empty(&splice) && nr) {
10299 root = list_first_entry(&splice, struct btrfs_root,
10300 delalloc_root);
10301 root = btrfs_grab_fs_root(root);
10302 BUG_ON(!root);
10303 list_move_tail(&root->delalloc_root,
10304 &fs_info->delalloc_roots);
10305 spin_unlock(&fs_info->delalloc_root_lock);
10306
10307 ret = __start_delalloc_inodes(root, delay_iput, nr);
10308 btrfs_put_fs_root(root);
10309 if (ret < 0)
10310 goto out;
10311
10312 if (nr != -1) {
10313 nr -= ret;
10314 WARN_ON(nr < 0);
10315 }
10316 spin_lock(&fs_info->delalloc_root_lock);
10317 }
10318 spin_unlock(&fs_info->delalloc_root_lock);
10319
10320 ret = 0;
10321out:
10322 if (!list_empty_careful(&splice)) {
10323 spin_lock(&fs_info->delalloc_root_lock);
10324 list_splice_tail(&splice, &fs_info->delalloc_roots);
10325 spin_unlock(&fs_info->delalloc_root_lock);
10326 }
10327 mutex_unlock(&fs_info->delalloc_root_mutex);
10328 return ret;
10329}
10330
10331static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
10332 const char *symname)
10333{
10334 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
10335 struct btrfs_trans_handle *trans;
10336 struct btrfs_root *root = BTRFS_I(dir)->root;
10337 struct btrfs_path *path;
10338 struct btrfs_key key;
10339 struct inode *inode = NULL;
10340 int err;
10341 int drop_inode = 0;
10342 u64 objectid;
10343 u64 index = 0;
10344 int name_len;
10345 int datasize;
10346 unsigned long ptr;
10347 struct btrfs_file_extent_item *ei;
10348 struct extent_buffer *leaf;
10349
10350 name_len = strlen(symname);
10351 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info))
10352 return -ENAMETOOLONG;
10353
10354 /*
10355 * 2 items for inode item and ref
10356 * 2 items for dir items
10357 * 1 item for updating parent inode item
10358 * 1 item for the inline extent item
10359 * 1 item for xattr if selinux is on
10360 */
10361 trans = btrfs_start_transaction(root, 7);
10362 if (IS_ERR(trans))
10363 return PTR_ERR(trans);
10364
10365 err = btrfs_find_free_ino(root, &objectid);
10366 if (err)
10367 goto out_unlock;
10368
10369 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
10370 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)),
10371 objectid, S_IFLNK|S_IRWXUGO, &index);
10372 if (IS_ERR(inode)) {
10373 err = PTR_ERR(inode);
10374 goto out_unlock;
10375 }
10376
10377 /*
10378 * If the active LSM wants to access the inode during
10379 * d_instantiate it needs these. Smack checks to see
10380 * if the filesystem supports xattrs by looking at the
10381 * ops vector.
10382 */
10383 inode->i_fop = &btrfs_file_operations;
10384 inode->i_op = &btrfs_file_inode_operations;
10385 inode->i_mapping->a_ops = &btrfs_aops;
10386 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10387
10388 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
10389 if (err)
10390 goto out_unlock_inode;
10391
10392 path = btrfs_alloc_path();
10393 if (!path) {
10394 err = -ENOMEM;
10395 goto out_unlock_inode;
10396 }
10397 key.objectid = btrfs_ino(BTRFS_I(inode));
10398 key.offset = 0;
10399 key.type = BTRFS_EXTENT_DATA_KEY;
10400 datasize = btrfs_file_extent_calc_inline_size(name_len);
10401 err = btrfs_insert_empty_item(trans, root, path, &key,
10402 datasize);
10403 if (err) {
10404 btrfs_free_path(path);
10405 goto out_unlock_inode;
10406 }
10407 leaf = path->nodes[0];
10408 ei = btrfs_item_ptr(leaf, path->slots[0],
10409 struct btrfs_file_extent_item);
10410 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
10411 btrfs_set_file_extent_type(leaf, ei,
10412 BTRFS_FILE_EXTENT_INLINE);
10413 btrfs_set_file_extent_encryption(leaf, ei, 0);
10414 btrfs_set_file_extent_compression(leaf, ei, 0);
10415 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
10416 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
10417
10418 ptr = btrfs_file_extent_inline_start(ei);
10419 write_extent_buffer(leaf, symname, ptr, name_len);
10420 btrfs_mark_buffer_dirty(leaf);
10421 btrfs_free_path(path);
10422
10423 inode->i_op = &btrfs_symlink_inode_operations;
10424 inode_nohighmem(inode);
10425 inode->i_mapping->a_ops = &btrfs_symlink_aops;
10426 inode_set_bytes(inode, name_len);
10427 btrfs_i_size_write(BTRFS_I(inode), name_len);
10428 err = btrfs_update_inode(trans, root, inode);
10429 /*
10430 * Last step, add directory indexes for our symlink inode. This is the
10431 * last step to avoid extra cleanup of these indexes if an error happens
10432 * elsewhere above.
10433 */
10434 if (!err)
10435 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
10436 BTRFS_I(inode), 0, index);
10437 if (err) {
10438 drop_inode = 1;
10439 goto out_unlock_inode;
10440 }
10441
10442 unlock_new_inode(inode);
10443 d_instantiate(dentry, inode);
10444
10445out_unlock:
10446 btrfs_end_transaction(trans);
10447 if (drop_inode) {
10448 inode_dec_link_count(inode);
10449 iput(inode);
10450 }
10451 btrfs_btree_balance_dirty(fs_info);
10452 return err;
10453
10454out_unlock_inode:
10455 drop_inode = 1;
10456 unlock_new_inode(inode);
10457 goto out_unlock;
10458}
10459
10460static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
10461 u64 start, u64 num_bytes, u64 min_size,
10462 loff_t actual_len, u64 *alloc_hint,
10463 struct btrfs_trans_handle *trans)
10464{
10465 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
10466 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
10467 struct extent_map *em;
10468 struct btrfs_root *root = BTRFS_I(inode)->root;
10469 struct btrfs_key ins;
10470 u64 cur_offset = start;
10471 u64 i_size;
10472 u64 cur_bytes;
10473 u64 last_alloc = (u64)-1;
10474 int ret = 0;
10475 bool own_trans = true;
10476 u64 end = start + num_bytes - 1;
10477
10478 if (trans)
10479 own_trans = false;
10480 while (num_bytes > 0) {
10481 if (own_trans) {
10482 trans = btrfs_start_transaction(root, 3);
10483 if (IS_ERR(trans)) {
10484 ret = PTR_ERR(trans);
10485 break;
10486 }
10487 }
10488
10489 cur_bytes = min_t(u64, num_bytes, SZ_256M);
10490 cur_bytes = max(cur_bytes, min_size);
10491 /*
10492 * If we are severely fragmented we could end up with really
10493 * small allocations, so if the allocator is returning small
10494 * chunks lets make its job easier by only searching for those
10495 * sized chunks.
10496 */
10497 cur_bytes = min(cur_bytes, last_alloc);
10498 ret = btrfs_reserve_extent(root, cur_bytes, cur_bytes,
10499 min_size, 0, *alloc_hint, &ins, 1, 0);
10500 if (ret) {
10501 if (own_trans)
10502 btrfs_end_transaction(trans);
10503 break;
10504 }
10505 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
10506
10507 last_alloc = ins.offset;
10508 ret = insert_reserved_file_extent(trans, inode,
10509 cur_offset, ins.objectid,
10510 ins.offset, ins.offset,
10511 ins.offset, 0, 0, 0,
10512 BTRFS_FILE_EXTENT_PREALLOC);
10513 if (ret) {
10514 btrfs_free_reserved_extent(fs_info, ins.objectid,
10515 ins.offset, 0);
10516 btrfs_abort_transaction(trans, ret);
10517 if (own_trans)
10518 btrfs_end_transaction(trans);
10519 break;
10520 }
10521
10522 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
10523 cur_offset + ins.offset -1, 0);
10524
10525 em = alloc_extent_map();
10526 if (!em) {
10527 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
10528 &BTRFS_I(inode)->runtime_flags);
10529 goto next;
10530 }
10531
10532 em->start = cur_offset;
10533 em->orig_start = cur_offset;
10534 em->len = ins.offset;
10535 em->block_start = ins.objectid;
10536 em->block_len = ins.offset;
10537 em->orig_block_len = ins.offset;
10538 em->ram_bytes = ins.offset;
10539 em->bdev = fs_info->fs_devices->latest_bdev;
10540 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
10541 em->generation = trans->transid;
10542
10543 while (1) {
10544 write_lock(&em_tree->lock);
10545 ret = add_extent_mapping(em_tree, em, 1);
10546 write_unlock(&em_tree->lock);
10547 if (ret != -EEXIST)
10548 break;
10549 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
10550 cur_offset + ins.offset - 1,
10551 0);
10552 }
10553 free_extent_map(em);
10554next:
10555 num_bytes -= ins.offset;
10556 cur_offset += ins.offset;
10557 *alloc_hint = ins.objectid + ins.offset;
10558
10559 inode_inc_iversion(inode);
10560 inode->i_ctime = current_time(inode);
10561 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
10562 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
10563 (actual_len > inode->i_size) &&
10564 (cur_offset > inode->i_size)) {
10565 if (cur_offset > actual_len)
10566 i_size = actual_len;
10567 else
10568 i_size = cur_offset;
10569 i_size_write(inode, i_size);
10570 btrfs_ordered_update_i_size(inode, i_size, NULL);
10571 }
10572
10573 ret = btrfs_update_inode(trans, root, inode);
10574
10575 if (ret) {
10576 btrfs_abort_transaction(trans, ret);
10577 if (own_trans)
10578 btrfs_end_transaction(trans);
10579 break;
10580 }
10581
10582 if (own_trans)
10583 btrfs_end_transaction(trans);
10584 }
10585 if (cur_offset < end)
10586 btrfs_free_reserved_data_space(inode, NULL, cur_offset,
10587 end - cur_offset + 1);
10588 return ret;
10589}
10590
10591int btrfs_prealloc_file_range(struct inode *inode, int mode,
10592 u64 start, u64 num_bytes, u64 min_size,
10593 loff_t actual_len, u64 *alloc_hint)
10594{
10595 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10596 min_size, actual_len, alloc_hint,
10597 NULL);
10598}
10599
10600int btrfs_prealloc_file_range_trans(struct inode *inode,
10601 struct btrfs_trans_handle *trans, int mode,
10602 u64 start, u64 num_bytes, u64 min_size,
10603 loff_t actual_len, u64 *alloc_hint)
10604{
10605 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10606 min_size, actual_len, alloc_hint, trans);
10607}
10608
10609static int btrfs_set_page_dirty(struct page *page)
10610{
10611 return __set_page_dirty_nobuffers(page);
10612}
10613
10614static int btrfs_permission(struct inode *inode, int mask)
10615{
10616 struct btrfs_root *root = BTRFS_I(inode)->root;
10617 umode_t mode = inode->i_mode;
10618
10619 if (mask & MAY_WRITE &&
10620 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
10621 if (btrfs_root_readonly(root))
10622 return -EROFS;
10623 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
10624 return -EACCES;
10625 }
10626 return generic_permission(inode, mask);
10627}
10628
10629static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
10630{
10631 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
10632 struct btrfs_trans_handle *trans;
10633 struct btrfs_root *root = BTRFS_I(dir)->root;
10634 struct inode *inode = NULL;
10635 u64 objectid;
10636 u64 index;
10637 int ret = 0;
10638
10639 /*
10640 * 5 units required for adding orphan entry
10641 */
10642 trans = btrfs_start_transaction(root, 5);
10643 if (IS_ERR(trans))
10644 return PTR_ERR(trans);
10645
10646 ret = btrfs_find_free_ino(root, &objectid);
10647 if (ret)
10648 goto out;
10649
10650 inode = btrfs_new_inode(trans, root, dir, NULL, 0,
10651 btrfs_ino(BTRFS_I(dir)), objectid, mode, &index);
10652 if (IS_ERR(inode)) {
10653 ret = PTR_ERR(inode);
10654 inode = NULL;
10655 goto out;
10656 }
10657
10658 inode->i_fop = &btrfs_file_operations;
10659 inode->i_op = &btrfs_file_inode_operations;
10660
10661 inode->i_mapping->a_ops = &btrfs_aops;
10662 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10663
10664 ret = btrfs_init_inode_security(trans, inode, dir, NULL);
10665 if (ret)
10666 goto out_inode;
10667
10668 ret = btrfs_update_inode(trans, root, inode);
10669 if (ret)
10670 goto out_inode;
10671 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
10672 if (ret)
10673 goto out_inode;
10674
10675 /*
10676 * We set number of links to 0 in btrfs_new_inode(), and here we set
10677 * it to 1 because d_tmpfile() will issue a warning if the count is 0,
10678 * through:
10679 *
10680 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
10681 */
10682 set_nlink(inode, 1);
10683 unlock_new_inode(inode);
10684 d_tmpfile(dentry, inode);
10685 mark_inode_dirty(inode);
10686
10687out:
10688 btrfs_end_transaction(trans);
10689 if (ret)
10690 iput(inode);
10691 btrfs_balance_delayed_items(fs_info);
10692 btrfs_btree_balance_dirty(fs_info);
10693 return ret;
10694
10695out_inode:
10696 unlock_new_inode(inode);
10697 goto out;
10698
10699}
10700
10701__attribute__((const))
10702static int btrfs_readpage_io_failed_hook(struct page *page, int failed_mirror)
10703{
10704 return -EAGAIN;
10705}
10706
10707static struct btrfs_fs_info *iotree_fs_info(void *private_data)
10708{
10709 struct inode *inode = private_data;
10710 return btrfs_sb(inode->i_sb);
10711}
10712
10713static void btrfs_check_extent_io_range(void *private_data, const char *caller,
10714 u64 start, u64 end)
10715{
10716 struct inode *inode = private_data;
10717 u64 isize;
10718
10719 isize = i_size_read(inode);
10720 if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) {
10721 btrfs_debug_rl(BTRFS_I(inode)->root->fs_info,
10722 "%s: ino %llu isize %llu odd range [%llu,%llu]",
10723 caller, btrfs_ino(BTRFS_I(inode)), isize, start, end);
10724 }
10725}
10726
10727void btrfs_set_range_writeback(void *private_data, u64 start, u64 end)
10728{
10729 struct inode *inode = private_data;
10730 unsigned long index = start >> PAGE_SHIFT;
10731 unsigned long end_index = end >> PAGE_SHIFT;
10732 struct page *page;
10733
10734 while (index <= end_index) {
10735 page = find_get_page(inode->i_mapping, index);
10736 ASSERT(page); /* Pages should be in the extent_io_tree */
10737 set_page_writeback(page);
10738 put_page(page);
10739 index++;
10740 }
10741}
10742
10743static const struct inode_operations btrfs_dir_inode_operations = {
10744 .getattr = btrfs_getattr,
10745 .lookup = btrfs_lookup,
10746 .create = btrfs_create,
10747 .unlink = btrfs_unlink,
10748 .link = btrfs_link,
10749 .mkdir = btrfs_mkdir,
10750 .rmdir = btrfs_rmdir,
10751 .rename = btrfs_rename2,
10752 .symlink = btrfs_symlink,
10753 .setattr = btrfs_setattr,
10754 .mknod = btrfs_mknod,
10755 .listxattr = btrfs_listxattr,
10756 .permission = btrfs_permission,
10757 .get_acl = btrfs_get_acl,
10758 .set_acl = btrfs_set_acl,
10759 .update_time = btrfs_update_time,
10760 .tmpfile = btrfs_tmpfile,
10761};
10762static const struct inode_operations btrfs_dir_ro_inode_operations = {
10763 .lookup = btrfs_lookup,
10764 .permission = btrfs_permission,
10765 .update_time = btrfs_update_time,
10766};
10767
10768static const struct file_operations btrfs_dir_file_operations = {
10769 .llseek = generic_file_llseek,
10770 .read = generic_read_dir,
10771 .iterate_shared = btrfs_real_readdir,
10772 .open = btrfs_opendir,
10773 .unlocked_ioctl = btrfs_ioctl,
10774#ifdef CONFIG_COMPAT
10775 .compat_ioctl = btrfs_compat_ioctl,
10776#endif
10777 .release = btrfs_release_file,
10778 .fsync = btrfs_sync_file,
10779};
10780
10781static const struct extent_io_ops btrfs_extent_io_ops = {
10782 /* mandatory callbacks */
10783 .submit_bio_hook = btrfs_submit_bio_hook,
10784 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
10785 .merge_bio_hook = btrfs_merge_bio_hook,
10786 .readpage_io_failed_hook = btrfs_readpage_io_failed_hook,
10787 .tree_fs_info = iotree_fs_info,
10788 .set_range_writeback = btrfs_set_range_writeback,
10789
10790 /* optional callbacks */
10791 .fill_delalloc = run_delalloc_range,
10792 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
10793 .writepage_start_hook = btrfs_writepage_start_hook,
10794 .set_bit_hook = btrfs_set_bit_hook,
10795 .clear_bit_hook = btrfs_clear_bit_hook,
10796 .merge_extent_hook = btrfs_merge_extent_hook,
10797 .split_extent_hook = btrfs_split_extent_hook,
10798 .check_extent_io_range = btrfs_check_extent_io_range,
10799};
10800
10801/*
10802 * btrfs doesn't support the bmap operation because swapfiles
10803 * use bmap to make a mapping of extents in the file. They assume
10804 * these extents won't change over the life of the file and they
10805 * use the bmap result to do IO directly to the drive.
10806 *
10807 * the btrfs bmap call would return logical addresses that aren't
10808 * suitable for IO and they also will change frequently as COW
10809 * operations happen. So, swapfile + btrfs == corruption.
10810 *
10811 * For now we're avoiding this by dropping bmap.
10812 */
10813static const struct address_space_operations btrfs_aops = {
10814 .readpage = btrfs_readpage,
10815 .writepage = btrfs_writepage,
10816 .writepages = btrfs_writepages,
10817 .readpages = btrfs_readpages,
10818 .direct_IO = btrfs_direct_IO,
10819 .invalidatepage = btrfs_invalidatepage,
10820 .releasepage = btrfs_releasepage,
10821 .set_page_dirty = btrfs_set_page_dirty,
10822 .error_remove_page = generic_error_remove_page,
10823};
10824
10825static const struct address_space_operations btrfs_symlink_aops = {
10826 .readpage = btrfs_readpage,
10827 .writepage = btrfs_writepage,
10828 .invalidatepage = btrfs_invalidatepage,
10829 .releasepage = btrfs_releasepage,
10830};
10831
10832static const struct inode_operations btrfs_file_inode_operations = {
10833 .getattr = btrfs_getattr,
10834 .setattr = btrfs_setattr,
10835 .listxattr = btrfs_listxattr,
10836 .permission = btrfs_permission,
10837 .fiemap = btrfs_fiemap,
10838 .get_acl = btrfs_get_acl,
10839 .set_acl = btrfs_set_acl,
10840 .update_time = btrfs_update_time,
10841};
10842static const struct inode_operations btrfs_special_inode_operations = {
10843 .getattr = btrfs_getattr,
10844 .setattr = btrfs_setattr,
10845 .permission = btrfs_permission,
10846 .listxattr = btrfs_listxattr,
10847 .get_acl = btrfs_get_acl,
10848 .set_acl = btrfs_set_acl,
10849 .update_time = btrfs_update_time,
10850};
10851static const struct inode_operations btrfs_symlink_inode_operations = {
10852 .get_link = page_get_link,
10853 .getattr = btrfs_getattr,
10854 .setattr = btrfs_setattr,
10855 .permission = btrfs_permission,
10856 .listxattr = btrfs_listxattr,
10857 .update_time = btrfs_update_time,
10858};
10859
10860const struct dentry_operations btrfs_dentry_operations = {
10861 .d_delete = btrfs_dentry_delete,
10862 .d_release = btrfs_dentry_release,
10863};
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