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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/slab.h>
20#include <linux/blkdev.h>
21#include <linux/writeback.h>
22#include <linux/pagevec.h>
23#include "ctree.h"
24#include "transaction.h"
25#include "btrfs_inode.h"
26#include "extent_io.h"
27
28static u64 entry_end(struct btrfs_ordered_extent *entry)
29{
30 if (entry->file_offset + entry->len < entry->file_offset)
31 return (u64)-1;
32 return entry->file_offset + entry->len;
33}
34
35/* returns NULL if the insertion worked, or it returns the node it did find
36 * in the tree
37 */
38static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
39 struct rb_node *node)
40{
41 struct rb_node **p = &root->rb_node;
42 struct rb_node *parent = NULL;
43 struct btrfs_ordered_extent *entry;
44
45 while (*p) {
46 parent = *p;
47 entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
48
49 if (file_offset < entry->file_offset)
50 p = &(*p)->rb_left;
51 else if (file_offset >= entry_end(entry))
52 p = &(*p)->rb_right;
53 else
54 return parent;
55 }
56
57 rb_link_node(node, parent, p);
58 rb_insert_color(node, root);
59 return NULL;
60}
61
62/*
63 * look for a given offset in the tree, and if it can't be found return the
64 * first lesser offset
65 */
66static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
67 struct rb_node **prev_ret)
68{
69 struct rb_node *n = root->rb_node;
70 struct rb_node *prev = NULL;
71 struct rb_node *test;
72 struct btrfs_ordered_extent *entry;
73 struct btrfs_ordered_extent *prev_entry = NULL;
74
75 while (n) {
76 entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
77 prev = n;
78 prev_entry = entry;
79
80 if (file_offset < entry->file_offset)
81 n = n->rb_left;
82 else if (file_offset >= entry_end(entry))
83 n = n->rb_right;
84 else
85 return n;
86 }
87 if (!prev_ret)
88 return NULL;
89
90 while (prev && file_offset >= entry_end(prev_entry)) {
91 test = rb_next(prev);
92 if (!test)
93 break;
94 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
95 rb_node);
96 if (file_offset < entry_end(prev_entry))
97 break;
98
99 prev = test;
100 }
101 if (prev)
102 prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
103 rb_node);
104 while (prev && file_offset < entry_end(prev_entry)) {
105 test = rb_prev(prev);
106 if (!test)
107 break;
108 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
109 rb_node);
110 prev = test;
111 }
112 *prev_ret = prev;
113 return NULL;
114}
115
116/*
117 * helper to check if a given offset is inside a given entry
118 */
119static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset)
120{
121 if (file_offset < entry->file_offset ||
122 entry->file_offset + entry->len <= file_offset)
123 return 0;
124 return 1;
125}
126
127static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
128 u64 len)
129{
130 if (file_offset + len <= entry->file_offset ||
131 entry->file_offset + entry->len <= file_offset)
132 return 0;
133 return 1;
134}
135
136/*
137 * look find the first ordered struct that has this offset, otherwise
138 * the first one less than this offset
139 */
140static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
141 u64 file_offset)
142{
143 struct rb_root *root = &tree->tree;
144 struct rb_node *prev = NULL;
145 struct rb_node *ret;
146 struct btrfs_ordered_extent *entry;
147
148 if (tree->last) {
149 entry = rb_entry(tree->last, struct btrfs_ordered_extent,
150 rb_node);
151 if (offset_in_entry(entry, file_offset))
152 return tree->last;
153 }
154 ret = __tree_search(root, file_offset, &prev);
155 if (!ret)
156 ret = prev;
157 if (ret)
158 tree->last = ret;
159 return ret;
160}
161
162/* allocate and add a new ordered_extent into the per-inode tree.
163 * file_offset is the logical offset in the file
164 *
165 * start is the disk block number of an extent already reserved in the
166 * extent allocation tree
167 *
168 * len is the length of the extent
169 *
170 * The tree is given a single reference on the ordered extent that was
171 * inserted.
172 */
173static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
174 u64 start, u64 len, u64 disk_len,
175 int type, int dio, int compress_type)
176{
177 struct btrfs_ordered_inode_tree *tree;
178 struct rb_node *node;
179 struct btrfs_ordered_extent *entry;
180
181 tree = &BTRFS_I(inode)->ordered_tree;
182 entry = kzalloc(sizeof(*entry), GFP_NOFS);
183 if (!entry)
184 return -ENOMEM;
185
186 entry->file_offset = file_offset;
187 entry->start = start;
188 entry->len = len;
189 entry->disk_len = disk_len;
190 entry->bytes_left = len;
191 entry->inode = inode;
192 entry->compress_type = compress_type;
193 if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
194 set_bit(type, &entry->flags);
195
196 if (dio)
197 set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
198
199 /* one ref for the tree */
200 atomic_set(&entry->refs, 1);
201 init_waitqueue_head(&entry->wait);
202 INIT_LIST_HEAD(&entry->list);
203 INIT_LIST_HEAD(&entry->root_extent_list);
204
205 trace_btrfs_ordered_extent_add(inode, entry);
206
207 spin_lock(&tree->lock);
208 node = tree_insert(&tree->tree, file_offset,
209 &entry->rb_node);
210 BUG_ON(node);
211 spin_unlock(&tree->lock);
212
213 spin_lock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
214 list_add_tail(&entry->root_extent_list,
215 &BTRFS_I(inode)->root->fs_info->ordered_extents);
216 spin_unlock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
217
218 BUG_ON(node);
219 return 0;
220}
221
222int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
223 u64 start, u64 len, u64 disk_len, int type)
224{
225 return __btrfs_add_ordered_extent(inode, file_offset, start, len,
226 disk_len, type, 0,
227 BTRFS_COMPRESS_NONE);
228}
229
230int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
231 u64 start, u64 len, u64 disk_len, int type)
232{
233 return __btrfs_add_ordered_extent(inode, file_offset, start, len,
234 disk_len, type, 1,
235 BTRFS_COMPRESS_NONE);
236}
237
238int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
239 u64 start, u64 len, u64 disk_len,
240 int type, int compress_type)
241{
242 return __btrfs_add_ordered_extent(inode, file_offset, start, len,
243 disk_len, type, 0,
244 compress_type);
245}
246
247/*
248 * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
249 * when an ordered extent is finished. If the list covers more than one
250 * ordered extent, it is split across multiples.
251 */
252int btrfs_add_ordered_sum(struct inode *inode,
253 struct btrfs_ordered_extent *entry,
254 struct btrfs_ordered_sum *sum)
255{
256 struct btrfs_ordered_inode_tree *tree;
257
258 tree = &BTRFS_I(inode)->ordered_tree;
259 spin_lock(&tree->lock);
260 list_add_tail(&sum->list, &entry->list);
261 spin_unlock(&tree->lock);
262 return 0;
263}
264
265/*
266 * this is used to account for finished IO across a given range
267 * of the file. The IO may span ordered extents. If
268 * a given ordered_extent is completely done, 1 is returned, otherwise
269 * 0.
270 *
271 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
272 * to make sure this function only returns 1 once for a given ordered extent.
273 *
274 * file_offset is updated to one byte past the range that is recorded as
275 * complete. This allows you to walk forward in the file.
276 */
277int btrfs_dec_test_first_ordered_pending(struct inode *inode,
278 struct btrfs_ordered_extent **cached,
279 u64 *file_offset, u64 io_size)
280{
281 struct btrfs_ordered_inode_tree *tree;
282 struct rb_node *node;
283 struct btrfs_ordered_extent *entry = NULL;
284 int ret;
285 u64 dec_end;
286 u64 dec_start;
287 u64 to_dec;
288
289 tree = &BTRFS_I(inode)->ordered_tree;
290 spin_lock(&tree->lock);
291 node = tree_search(tree, *file_offset);
292 if (!node) {
293 ret = 1;
294 goto out;
295 }
296
297 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
298 if (!offset_in_entry(entry, *file_offset)) {
299 ret = 1;
300 goto out;
301 }
302
303 dec_start = max(*file_offset, entry->file_offset);
304 dec_end = min(*file_offset + io_size, entry->file_offset +
305 entry->len);
306 *file_offset = dec_end;
307 if (dec_start > dec_end) {
308 printk(KERN_CRIT "bad ordering dec_start %llu end %llu\n",
309 (unsigned long long)dec_start,
310 (unsigned long long)dec_end);
311 }
312 to_dec = dec_end - dec_start;
313 if (to_dec > entry->bytes_left) {
314 printk(KERN_CRIT "bad ordered accounting left %llu size %llu\n",
315 (unsigned long long)entry->bytes_left,
316 (unsigned long long)to_dec);
317 }
318 entry->bytes_left -= to_dec;
319 if (entry->bytes_left == 0)
320 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
321 else
322 ret = 1;
323out:
324 if (!ret && cached && entry) {
325 *cached = entry;
326 atomic_inc(&entry->refs);
327 }
328 spin_unlock(&tree->lock);
329 return ret == 0;
330}
331
332/*
333 * this is used to account for finished IO across a given range
334 * of the file. The IO should not span ordered extents. If
335 * a given ordered_extent is completely done, 1 is returned, otherwise
336 * 0.
337 *
338 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
339 * to make sure this function only returns 1 once for a given ordered extent.
340 */
341int btrfs_dec_test_ordered_pending(struct inode *inode,
342 struct btrfs_ordered_extent **cached,
343 u64 file_offset, u64 io_size)
344{
345 struct btrfs_ordered_inode_tree *tree;
346 struct rb_node *node;
347 struct btrfs_ordered_extent *entry = NULL;
348 int ret;
349
350 tree = &BTRFS_I(inode)->ordered_tree;
351 spin_lock(&tree->lock);
352 node = tree_search(tree, file_offset);
353 if (!node) {
354 ret = 1;
355 goto out;
356 }
357
358 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
359 if (!offset_in_entry(entry, file_offset)) {
360 ret = 1;
361 goto out;
362 }
363
364 if (io_size > entry->bytes_left) {
365 printk(KERN_CRIT "bad ordered accounting left %llu size %llu\n",
366 (unsigned long long)entry->bytes_left,
367 (unsigned long long)io_size);
368 }
369 entry->bytes_left -= io_size;
370 if (entry->bytes_left == 0)
371 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
372 else
373 ret = 1;
374out:
375 if (!ret && cached && entry) {
376 *cached = entry;
377 atomic_inc(&entry->refs);
378 }
379 spin_unlock(&tree->lock);
380 return ret == 0;
381}
382
383/*
384 * used to drop a reference on an ordered extent. This will free
385 * the extent if the last reference is dropped
386 */
387int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
388{
389 struct list_head *cur;
390 struct btrfs_ordered_sum *sum;
391
392 trace_btrfs_ordered_extent_put(entry->inode, entry);
393
394 if (atomic_dec_and_test(&entry->refs)) {
395 while (!list_empty(&entry->list)) {
396 cur = entry->list.next;
397 sum = list_entry(cur, struct btrfs_ordered_sum, list);
398 list_del(&sum->list);
399 kfree(sum);
400 }
401 kfree(entry);
402 }
403 return 0;
404}
405
406/*
407 * remove an ordered extent from the tree. No references are dropped
408 * and you must wake_up entry->wait. You must hold the tree lock
409 * while you call this function.
410 */
411static int __btrfs_remove_ordered_extent(struct inode *inode,
412 struct btrfs_ordered_extent *entry)
413{
414 struct btrfs_ordered_inode_tree *tree;
415 struct btrfs_root *root = BTRFS_I(inode)->root;
416 struct rb_node *node;
417
418 tree = &BTRFS_I(inode)->ordered_tree;
419 node = &entry->rb_node;
420 rb_erase(node, &tree->tree);
421 tree->last = NULL;
422 set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
423
424 spin_lock(&root->fs_info->ordered_extent_lock);
425 list_del_init(&entry->root_extent_list);
426
427 trace_btrfs_ordered_extent_remove(inode, entry);
428
429 /*
430 * we have no more ordered extents for this inode and
431 * no dirty pages. We can safely remove it from the
432 * list of ordered extents
433 */
434 if (RB_EMPTY_ROOT(&tree->tree) &&
435 !mapping_tagged(inode->i_mapping, PAGECACHE_TAG_DIRTY)) {
436 list_del_init(&BTRFS_I(inode)->ordered_operations);
437 }
438 spin_unlock(&root->fs_info->ordered_extent_lock);
439
440 return 0;
441}
442
443/*
444 * remove an ordered extent from the tree. No references are dropped
445 * but any waiters are woken.
446 */
447int btrfs_remove_ordered_extent(struct inode *inode,
448 struct btrfs_ordered_extent *entry)
449{
450 struct btrfs_ordered_inode_tree *tree;
451 int ret;
452
453 tree = &BTRFS_I(inode)->ordered_tree;
454 spin_lock(&tree->lock);
455 ret = __btrfs_remove_ordered_extent(inode, entry);
456 spin_unlock(&tree->lock);
457 wake_up(&entry->wait);
458
459 return ret;
460}
461
462/*
463 * wait for all the ordered extents in a root. This is done when balancing
464 * space between drives.
465 */
466int btrfs_wait_ordered_extents(struct btrfs_root *root,
467 int nocow_only, int delay_iput)
468{
469 struct list_head splice;
470 struct list_head *cur;
471 struct btrfs_ordered_extent *ordered;
472 struct inode *inode;
473
474 INIT_LIST_HEAD(&splice);
475
476 spin_lock(&root->fs_info->ordered_extent_lock);
477 list_splice_init(&root->fs_info->ordered_extents, &splice);
478 while (!list_empty(&splice)) {
479 cur = splice.next;
480 ordered = list_entry(cur, struct btrfs_ordered_extent,
481 root_extent_list);
482 if (nocow_only &&
483 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags) &&
484 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags)) {
485 list_move(&ordered->root_extent_list,
486 &root->fs_info->ordered_extents);
487 cond_resched_lock(&root->fs_info->ordered_extent_lock);
488 continue;
489 }
490
491 list_del_init(&ordered->root_extent_list);
492 atomic_inc(&ordered->refs);
493
494 /*
495 * the inode may be getting freed (in sys_unlink path).
496 */
497 inode = igrab(ordered->inode);
498
499 spin_unlock(&root->fs_info->ordered_extent_lock);
500
501 if (inode) {
502 btrfs_start_ordered_extent(inode, ordered, 1);
503 btrfs_put_ordered_extent(ordered);
504 if (delay_iput)
505 btrfs_add_delayed_iput(inode);
506 else
507 iput(inode);
508 } else {
509 btrfs_put_ordered_extent(ordered);
510 }
511
512 spin_lock(&root->fs_info->ordered_extent_lock);
513 }
514 spin_unlock(&root->fs_info->ordered_extent_lock);
515 return 0;
516}
517
518/*
519 * this is used during transaction commit to write all the inodes
520 * added to the ordered operation list. These files must be fully on
521 * disk before the transaction commits.
522 *
523 * we have two modes here, one is to just start the IO via filemap_flush
524 * and the other is to wait for all the io. When we wait, we have an
525 * extra check to make sure the ordered operation list really is empty
526 * before we return
527 */
528int btrfs_run_ordered_operations(struct btrfs_root *root, int wait)
529{
530 struct btrfs_inode *btrfs_inode;
531 struct inode *inode;
532 struct list_head splice;
533
534 INIT_LIST_HEAD(&splice);
535
536 mutex_lock(&root->fs_info->ordered_operations_mutex);
537 spin_lock(&root->fs_info->ordered_extent_lock);
538again:
539 list_splice_init(&root->fs_info->ordered_operations, &splice);
540
541 while (!list_empty(&splice)) {
542 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
543 ordered_operations);
544
545 inode = &btrfs_inode->vfs_inode;
546
547 list_del_init(&btrfs_inode->ordered_operations);
548
549 /*
550 * the inode may be getting freed (in sys_unlink path).
551 */
552 inode = igrab(inode);
553
554 if (!wait && inode) {
555 list_add_tail(&BTRFS_I(inode)->ordered_operations,
556 &root->fs_info->ordered_operations);
557 }
558 spin_unlock(&root->fs_info->ordered_extent_lock);
559
560 if (inode) {
561 if (wait)
562 btrfs_wait_ordered_range(inode, 0, (u64)-1);
563 else
564 filemap_flush(inode->i_mapping);
565 btrfs_add_delayed_iput(inode);
566 }
567
568 cond_resched();
569 spin_lock(&root->fs_info->ordered_extent_lock);
570 }
571 if (wait && !list_empty(&root->fs_info->ordered_operations))
572 goto again;
573
574 spin_unlock(&root->fs_info->ordered_extent_lock);
575 mutex_unlock(&root->fs_info->ordered_operations_mutex);
576
577 return 0;
578}
579
580/*
581 * Used to start IO or wait for a given ordered extent to finish.
582 *
583 * If wait is one, this effectively waits on page writeback for all the pages
584 * in the extent, and it waits on the io completion code to insert
585 * metadata into the btree corresponding to the extent
586 */
587void btrfs_start_ordered_extent(struct inode *inode,
588 struct btrfs_ordered_extent *entry,
589 int wait)
590{
591 u64 start = entry->file_offset;
592 u64 end = start + entry->len - 1;
593
594 trace_btrfs_ordered_extent_start(inode, entry);
595
596 /*
597 * pages in the range can be dirty, clean or writeback. We
598 * start IO on any dirty ones so the wait doesn't stall waiting
599 * for pdflush to find them
600 */
601 if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
602 filemap_fdatawrite_range(inode->i_mapping, start, end);
603 if (wait) {
604 wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
605 &entry->flags));
606 }
607}
608
609/*
610 * Used to wait on ordered extents across a large range of bytes.
611 */
612int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
613{
614 u64 end;
615 u64 orig_end;
616 struct btrfs_ordered_extent *ordered;
617 int found;
618
619 if (start + len < start) {
620 orig_end = INT_LIMIT(loff_t);
621 } else {
622 orig_end = start + len - 1;
623 if (orig_end > INT_LIMIT(loff_t))
624 orig_end = INT_LIMIT(loff_t);
625 }
626again:
627 /* start IO across the range first to instantiate any delalloc
628 * extents
629 */
630 filemap_fdatawrite_range(inode->i_mapping, start, orig_end);
631
632 /* The compression code will leave pages locked but return from
633 * writepage without setting the page writeback. Starting again
634 * with WB_SYNC_ALL will end up waiting for the IO to actually start.
635 */
636 filemap_fdatawrite_range(inode->i_mapping, start, orig_end);
637
638 filemap_fdatawait_range(inode->i_mapping, start, orig_end);
639
640 end = orig_end;
641 found = 0;
642 while (1) {
643 ordered = btrfs_lookup_first_ordered_extent(inode, end);
644 if (!ordered)
645 break;
646 if (ordered->file_offset > orig_end) {
647 btrfs_put_ordered_extent(ordered);
648 break;
649 }
650 if (ordered->file_offset + ordered->len < start) {
651 btrfs_put_ordered_extent(ordered);
652 break;
653 }
654 found++;
655 btrfs_start_ordered_extent(inode, ordered, 1);
656 end = ordered->file_offset;
657 btrfs_put_ordered_extent(ordered);
658 if (end == 0 || end == start)
659 break;
660 end--;
661 }
662 if (found || test_range_bit(&BTRFS_I(inode)->io_tree, start, orig_end,
663 EXTENT_DELALLOC, 0, NULL)) {
664 schedule_timeout(1);
665 goto again;
666 }
667 return 0;
668}
669
670/*
671 * find an ordered extent corresponding to file_offset. return NULL if
672 * nothing is found, otherwise take a reference on the extent and return it
673 */
674struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
675 u64 file_offset)
676{
677 struct btrfs_ordered_inode_tree *tree;
678 struct rb_node *node;
679 struct btrfs_ordered_extent *entry = NULL;
680
681 tree = &BTRFS_I(inode)->ordered_tree;
682 spin_lock(&tree->lock);
683 node = tree_search(tree, file_offset);
684 if (!node)
685 goto out;
686
687 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
688 if (!offset_in_entry(entry, file_offset))
689 entry = NULL;
690 if (entry)
691 atomic_inc(&entry->refs);
692out:
693 spin_unlock(&tree->lock);
694 return entry;
695}
696
697/* Since the DIO code tries to lock a wide area we need to look for any ordered
698 * extents that exist in the range, rather than just the start of the range.
699 */
700struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode,
701 u64 file_offset,
702 u64 len)
703{
704 struct btrfs_ordered_inode_tree *tree;
705 struct rb_node *node;
706 struct btrfs_ordered_extent *entry = NULL;
707
708 tree = &BTRFS_I(inode)->ordered_tree;
709 spin_lock(&tree->lock);
710 node = tree_search(tree, file_offset);
711 if (!node) {
712 node = tree_search(tree, file_offset + len);
713 if (!node)
714 goto out;
715 }
716
717 while (1) {
718 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
719 if (range_overlaps(entry, file_offset, len))
720 break;
721
722 if (entry->file_offset >= file_offset + len) {
723 entry = NULL;
724 break;
725 }
726 entry = NULL;
727 node = rb_next(node);
728 if (!node)
729 break;
730 }
731out:
732 if (entry)
733 atomic_inc(&entry->refs);
734 spin_unlock(&tree->lock);
735 return entry;
736}
737
738/*
739 * lookup and return any extent before 'file_offset'. NULL is returned
740 * if none is found
741 */
742struct btrfs_ordered_extent *
743btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset)
744{
745 struct btrfs_ordered_inode_tree *tree;
746 struct rb_node *node;
747 struct btrfs_ordered_extent *entry = NULL;
748
749 tree = &BTRFS_I(inode)->ordered_tree;
750 spin_lock(&tree->lock);
751 node = tree_search(tree, file_offset);
752 if (!node)
753 goto out;
754
755 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
756 atomic_inc(&entry->refs);
757out:
758 spin_unlock(&tree->lock);
759 return entry;
760}
761
762/*
763 * After an extent is done, call this to conditionally update the on disk
764 * i_size. i_size is updated to cover any fully written part of the file.
765 */
766int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
767 struct btrfs_ordered_extent *ordered)
768{
769 struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
770 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
771 u64 disk_i_size;
772 u64 new_i_size;
773 u64 i_size_test;
774 u64 i_size = i_size_read(inode);
775 struct rb_node *node;
776 struct rb_node *prev = NULL;
777 struct btrfs_ordered_extent *test;
778 int ret = 1;
779
780 if (ordered)
781 offset = entry_end(ordered);
782 else
783 offset = ALIGN(offset, BTRFS_I(inode)->root->sectorsize);
784
785 spin_lock(&tree->lock);
786 disk_i_size = BTRFS_I(inode)->disk_i_size;
787
788 /* truncate file */
789 if (disk_i_size > i_size) {
790 BTRFS_I(inode)->disk_i_size = i_size;
791 ret = 0;
792 goto out;
793 }
794
795 /*
796 * if the disk i_size is already at the inode->i_size, or
797 * this ordered extent is inside the disk i_size, we're done
798 */
799 if (disk_i_size == i_size || offset <= disk_i_size) {
800 goto out;
801 }
802
803 /*
804 * we can't update the disk_isize if there are delalloc bytes
805 * between disk_i_size and this ordered extent
806 */
807 if (test_range_bit(io_tree, disk_i_size, offset - 1,
808 EXTENT_DELALLOC, 0, NULL)) {
809 goto out;
810 }
811 /*
812 * walk backward from this ordered extent to disk_i_size.
813 * if we find an ordered extent then we can't update disk i_size
814 * yet
815 */
816 if (ordered) {
817 node = rb_prev(&ordered->rb_node);
818 } else {
819 prev = tree_search(tree, offset);
820 /*
821 * we insert file extents without involving ordered struct,
822 * so there should be no ordered struct cover this offset
823 */
824 if (prev) {
825 test = rb_entry(prev, struct btrfs_ordered_extent,
826 rb_node);
827 BUG_ON(offset_in_entry(test, offset));
828 }
829 node = prev;
830 }
831 while (node) {
832 test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
833 if (test->file_offset + test->len <= disk_i_size)
834 break;
835 if (test->file_offset >= i_size)
836 break;
837 if (test->file_offset >= disk_i_size)
838 goto out;
839 node = rb_prev(node);
840 }
841 new_i_size = min_t(u64, offset, i_size);
842
843 /*
844 * at this point, we know we can safely update i_size to at least
845 * the offset from this ordered extent. But, we need to
846 * walk forward and see if ios from higher up in the file have
847 * finished.
848 */
849 if (ordered) {
850 node = rb_next(&ordered->rb_node);
851 } else {
852 if (prev)
853 node = rb_next(prev);
854 else
855 node = rb_first(&tree->tree);
856 }
857 i_size_test = 0;
858 if (node) {
859 /*
860 * do we have an area where IO might have finished
861 * between our ordered extent and the next one.
862 */
863 test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
864 if (test->file_offset > offset)
865 i_size_test = test->file_offset;
866 } else {
867 i_size_test = i_size;
868 }
869
870 /*
871 * i_size_test is the end of a region after this ordered
872 * extent where there are no ordered extents. As long as there
873 * are no delalloc bytes in this area, it is safe to update
874 * disk_i_size to the end of the region.
875 */
876 if (i_size_test > offset &&
877 !test_range_bit(io_tree, offset, i_size_test - 1,
878 EXTENT_DELALLOC, 0, NULL)) {
879 new_i_size = min_t(u64, i_size_test, i_size);
880 }
881 BTRFS_I(inode)->disk_i_size = new_i_size;
882 ret = 0;
883out:
884 /*
885 * we need to remove the ordered extent with the tree lock held
886 * so that other people calling this function don't find our fully
887 * processed ordered entry and skip updating the i_size
888 */
889 if (ordered)
890 __btrfs_remove_ordered_extent(inode, ordered);
891 spin_unlock(&tree->lock);
892 if (ordered)
893 wake_up(&ordered->wait);
894 return ret;
895}
896
897/*
898 * search the ordered extents for one corresponding to 'offset' and
899 * try to find a checksum. This is used because we allow pages to
900 * be reclaimed before their checksum is actually put into the btree
901 */
902int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
903 u32 *sum)
904{
905 struct btrfs_ordered_sum *ordered_sum;
906 struct btrfs_sector_sum *sector_sums;
907 struct btrfs_ordered_extent *ordered;
908 struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
909 unsigned long num_sectors;
910 unsigned long i;
911 u32 sectorsize = BTRFS_I(inode)->root->sectorsize;
912 int ret = 1;
913
914 ordered = btrfs_lookup_ordered_extent(inode, offset);
915 if (!ordered)
916 return 1;
917
918 spin_lock(&tree->lock);
919 list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
920 if (disk_bytenr >= ordered_sum->bytenr) {
921 num_sectors = ordered_sum->len / sectorsize;
922 sector_sums = ordered_sum->sums;
923 for (i = 0; i < num_sectors; i++) {
924 if (sector_sums[i].bytenr == disk_bytenr) {
925 *sum = sector_sums[i].sum;
926 ret = 0;
927 goto out;
928 }
929 }
930 }
931 }
932out:
933 spin_unlock(&tree->lock);
934 btrfs_put_ordered_extent(ordered);
935 return ret;
936}
937
938
939/*
940 * add a given inode to the list of inodes that must be fully on
941 * disk before a transaction commit finishes.
942 *
943 * This basically gives us the ext3 style data=ordered mode, and it is mostly
944 * used to make sure renamed files are fully on disk.
945 *
946 * It is a noop if the inode is already fully on disk.
947 *
948 * If trans is not null, we'll do a friendly check for a transaction that
949 * is already flushing things and force the IO down ourselves.
950 */
951int btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
952 struct btrfs_root *root,
953 struct inode *inode)
954{
955 u64 last_mod;
956
957 last_mod = max(BTRFS_I(inode)->generation, BTRFS_I(inode)->last_trans);
958
959 /*
960 * if this file hasn't been changed since the last transaction
961 * commit, we can safely return without doing anything
962 */
963 if (last_mod < root->fs_info->last_trans_committed)
964 return 0;
965
966 /*
967 * the transaction is already committing. Just start the IO and
968 * don't bother with all of this list nonsense
969 */
970 if (trans && root->fs_info->running_transaction->blocked) {
971 btrfs_wait_ordered_range(inode, 0, (u64)-1);
972 return 0;
973 }
974
975 spin_lock(&root->fs_info->ordered_extent_lock);
976 if (list_empty(&BTRFS_I(inode)->ordered_operations)) {
977 list_add_tail(&BTRFS_I(inode)->ordered_operations,
978 &root->fs_info->ordered_operations);
979 }
980 spin_unlock(&root->fs_info->ordered_extent_lock);
981
982 return 0;
983}
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/slab.h>
20#include <linux/blkdev.h>
21#include <linux/writeback.h>
22#include <linux/pagevec.h>
23#include "ctree.h"
24#include "transaction.h"
25#include "btrfs_inode.h"
26#include "extent_io.h"
27#include "disk-io.h"
28#include "compression.h"
29
30static struct kmem_cache *btrfs_ordered_extent_cache;
31
32static u64 entry_end(struct btrfs_ordered_extent *entry)
33{
34 if (entry->file_offset + entry->len < entry->file_offset)
35 return (u64)-1;
36 return entry->file_offset + entry->len;
37}
38
39/* returns NULL if the insertion worked, or it returns the node it did find
40 * in the tree
41 */
42static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
43 struct rb_node *node)
44{
45 struct rb_node **p = &root->rb_node;
46 struct rb_node *parent = NULL;
47 struct btrfs_ordered_extent *entry;
48
49 while (*p) {
50 parent = *p;
51 entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
52
53 if (file_offset < entry->file_offset)
54 p = &(*p)->rb_left;
55 else if (file_offset >= entry_end(entry))
56 p = &(*p)->rb_right;
57 else
58 return parent;
59 }
60
61 rb_link_node(node, parent, p);
62 rb_insert_color(node, root);
63 return NULL;
64}
65
66static void ordered_data_tree_panic(struct inode *inode, int errno,
67 u64 offset)
68{
69 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
70 btrfs_panic(fs_info, errno, "Inconsistency in ordered tree at offset "
71 "%llu", offset);
72}
73
74/*
75 * look for a given offset in the tree, and if it can't be found return the
76 * first lesser offset
77 */
78static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
79 struct rb_node **prev_ret)
80{
81 struct rb_node *n = root->rb_node;
82 struct rb_node *prev = NULL;
83 struct rb_node *test;
84 struct btrfs_ordered_extent *entry;
85 struct btrfs_ordered_extent *prev_entry = NULL;
86
87 while (n) {
88 entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
89 prev = n;
90 prev_entry = entry;
91
92 if (file_offset < entry->file_offset)
93 n = n->rb_left;
94 else if (file_offset >= entry_end(entry))
95 n = n->rb_right;
96 else
97 return n;
98 }
99 if (!prev_ret)
100 return NULL;
101
102 while (prev && file_offset >= entry_end(prev_entry)) {
103 test = rb_next(prev);
104 if (!test)
105 break;
106 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
107 rb_node);
108 if (file_offset < entry_end(prev_entry))
109 break;
110
111 prev = test;
112 }
113 if (prev)
114 prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
115 rb_node);
116 while (prev && file_offset < entry_end(prev_entry)) {
117 test = rb_prev(prev);
118 if (!test)
119 break;
120 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
121 rb_node);
122 prev = test;
123 }
124 *prev_ret = prev;
125 return NULL;
126}
127
128/*
129 * helper to check if a given offset is inside a given entry
130 */
131static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset)
132{
133 if (file_offset < entry->file_offset ||
134 entry->file_offset + entry->len <= file_offset)
135 return 0;
136 return 1;
137}
138
139static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
140 u64 len)
141{
142 if (file_offset + len <= entry->file_offset ||
143 entry->file_offset + entry->len <= file_offset)
144 return 0;
145 return 1;
146}
147
148/*
149 * look find the first ordered struct that has this offset, otherwise
150 * the first one less than this offset
151 */
152static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
153 u64 file_offset)
154{
155 struct rb_root *root = &tree->tree;
156 struct rb_node *prev = NULL;
157 struct rb_node *ret;
158 struct btrfs_ordered_extent *entry;
159
160 if (tree->last) {
161 entry = rb_entry(tree->last, struct btrfs_ordered_extent,
162 rb_node);
163 if (offset_in_entry(entry, file_offset))
164 return tree->last;
165 }
166 ret = __tree_search(root, file_offset, &prev);
167 if (!ret)
168 ret = prev;
169 if (ret)
170 tree->last = ret;
171 return ret;
172}
173
174/* allocate and add a new ordered_extent into the per-inode tree.
175 * file_offset is the logical offset in the file
176 *
177 * start is the disk block number of an extent already reserved in the
178 * extent allocation tree
179 *
180 * len is the length of the extent
181 *
182 * The tree is given a single reference on the ordered extent that was
183 * inserted.
184 */
185static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
186 u64 start, u64 len, u64 disk_len,
187 int type, int dio, int compress_type)
188{
189 struct btrfs_root *root = BTRFS_I(inode)->root;
190 struct btrfs_ordered_inode_tree *tree;
191 struct rb_node *node;
192 struct btrfs_ordered_extent *entry;
193
194 tree = &BTRFS_I(inode)->ordered_tree;
195 entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
196 if (!entry)
197 return -ENOMEM;
198
199 entry->file_offset = file_offset;
200 entry->start = start;
201 entry->len = len;
202 entry->disk_len = disk_len;
203 entry->bytes_left = len;
204 entry->inode = igrab(inode);
205 entry->compress_type = compress_type;
206 entry->truncated_len = (u64)-1;
207 if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
208 set_bit(type, &entry->flags);
209
210 if (dio)
211 set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
212
213 /* one ref for the tree */
214 atomic_set(&entry->refs, 1);
215 init_waitqueue_head(&entry->wait);
216 INIT_LIST_HEAD(&entry->list);
217 INIT_LIST_HEAD(&entry->root_extent_list);
218 INIT_LIST_HEAD(&entry->work_list);
219 init_completion(&entry->completion);
220 INIT_LIST_HEAD(&entry->log_list);
221 INIT_LIST_HEAD(&entry->trans_list);
222
223 trace_btrfs_ordered_extent_add(inode, entry);
224
225 spin_lock_irq(&tree->lock);
226 node = tree_insert(&tree->tree, file_offset,
227 &entry->rb_node);
228 if (node)
229 ordered_data_tree_panic(inode, -EEXIST, file_offset);
230 spin_unlock_irq(&tree->lock);
231
232 spin_lock(&root->ordered_extent_lock);
233 list_add_tail(&entry->root_extent_list,
234 &root->ordered_extents);
235 root->nr_ordered_extents++;
236 if (root->nr_ordered_extents == 1) {
237 spin_lock(&root->fs_info->ordered_root_lock);
238 BUG_ON(!list_empty(&root->ordered_root));
239 list_add_tail(&root->ordered_root,
240 &root->fs_info->ordered_roots);
241 spin_unlock(&root->fs_info->ordered_root_lock);
242 }
243 spin_unlock(&root->ordered_extent_lock);
244
245 return 0;
246}
247
248int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
249 u64 start, u64 len, u64 disk_len, int type)
250{
251 return __btrfs_add_ordered_extent(inode, file_offset, start, len,
252 disk_len, type, 0,
253 BTRFS_COMPRESS_NONE);
254}
255
256int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
257 u64 start, u64 len, u64 disk_len, int type)
258{
259 return __btrfs_add_ordered_extent(inode, file_offset, start, len,
260 disk_len, type, 1,
261 BTRFS_COMPRESS_NONE);
262}
263
264int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
265 u64 start, u64 len, u64 disk_len,
266 int type, int compress_type)
267{
268 return __btrfs_add_ordered_extent(inode, file_offset, start, len,
269 disk_len, type, 0,
270 compress_type);
271}
272
273/*
274 * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
275 * when an ordered extent is finished. If the list covers more than one
276 * ordered extent, it is split across multiples.
277 */
278void btrfs_add_ordered_sum(struct inode *inode,
279 struct btrfs_ordered_extent *entry,
280 struct btrfs_ordered_sum *sum)
281{
282 struct btrfs_ordered_inode_tree *tree;
283
284 tree = &BTRFS_I(inode)->ordered_tree;
285 spin_lock_irq(&tree->lock);
286 list_add_tail(&sum->list, &entry->list);
287 spin_unlock_irq(&tree->lock);
288}
289
290/*
291 * this is used to account for finished IO across a given range
292 * of the file. The IO may span ordered extents. If
293 * a given ordered_extent is completely done, 1 is returned, otherwise
294 * 0.
295 *
296 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
297 * to make sure this function only returns 1 once for a given ordered extent.
298 *
299 * file_offset is updated to one byte past the range that is recorded as
300 * complete. This allows you to walk forward in the file.
301 */
302int btrfs_dec_test_first_ordered_pending(struct inode *inode,
303 struct btrfs_ordered_extent **cached,
304 u64 *file_offset, u64 io_size, int uptodate)
305{
306 struct btrfs_ordered_inode_tree *tree;
307 struct rb_node *node;
308 struct btrfs_ordered_extent *entry = NULL;
309 int ret;
310 unsigned long flags;
311 u64 dec_end;
312 u64 dec_start;
313 u64 to_dec;
314
315 tree = &BTRFS_I(inode)->ordered_tree;
316 spin_lock_irqsave(&tree->lock, flags);
317 node = tree_search(tree, *file_offset);
318 if (!node) {
319 ret = 1;
320 goto out;
321 }
322
323 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
324 if (!offset_in_entry(entry, *file_offset)) {
325 ret = 1;
326 goto out;
327 }
328
329 dec_start = max(*file_offset, entry->file_offset);
330 dec_end = min(*file_offset + io_size, entry->file_offset +
331 entry->len);
332 *file_offset = dec_end;
333 if (dec_start > dec_end) {
334 btrfs_crit(BTRFS_I(inode)->root->fs_info,
335 "bad ordering dec_start %llu end %llu", dec_start, dec_end);
336 }
337 to_dec = dec_end - dec_start;
338 if (to_dec > entry->bytes_left) {
339 btrfs_crit(BTRFS_I(inode)->root->fs_info,
340 "bad ordered accounting left %llu size %llu",
341 entry->bytes_left, to_dec);
342 }
343 entry->bytes_left -= to_dec;
344 if (!uptodate)
345 set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
346
347 if (entry->bytes_left == 0) {
348 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
349 /*
350 * Implicit memory barrier after test_and_set_bit
351 */
352 if (waitqueue_active(&entry->wait))
353 wake_up(&entry->wait);
354 } else {
355 ret = 1;
356 }
357out:
358 if (!ret && cached && entry) {
359 *cached = entry;
360 atomic_inc(&entry->refs);
361 }
362 spin_unlock_irqrestore(&tree->lock, flags);
363 return ret == 0;
364}
365
366/*
367 * this is used to account for finished IO across a given range
368 * of the file. The IO should not span ordered extents. If
369 * a given ordered_extent is completely done, 1 is returned, otherwise
370 * 0.
371 *
372 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
373 * to make sure this function only returns 1 once for a given ordered extent.
374 */
375int btrfs_dec_test_ordered_pending(struct inode *inode,
376 struct btrfs_ordered_extent **cached,
377 u64 file_offset, u64 io_size, int uptodate)
378{
379 struct btrfs_ordered_inode_tree *tree;
380 struct rb_node *node;
381 struct btrfs_ordered_extent *entry = NULL;
382 unsigned long flags;
383 int ret;
384
385 tree = &BTRFS_I(inode)->ordered_tree;
386 spin_lock_irqsave(&tree->lock, flags);
387 if (cached && *cached) {
388 entry = *cached;
389 goto have_entry;
390 }
391
392 node = tree_search(tree, file_offset);
393 if (!node) {
394 ret = 1;
395 goto out;
396 }
397
398 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
399have_entry:
400 if (!offset_in_entry(entry, file_offset)) {
401 ret = 1;
402 goto out;
403 }
404
405 if (io_size > entry->bytes_left) {
406 btrfs_crit(BTRFS_I(inode)->root->fs_info,
407 "bad ordered accounting left %llu size %llu",
408 entry->bytes_left, io_size);
409 }
410 entry->bytes_left -= io_size;
411 if (!uptodate)
412 set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
413
414 if (entry->bytes_left == 0) {
415 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
416 /*
417 * Implicit memory barrier after test_and_set_bit
418 */
419 if (waitqueue_active(&entry->wait))
420 wake_up(&entry->wait);
421 } else {
422 ret = 1;
423 }
424out:
425 if (!ret && cached && entry) {
426 *cached = entry;
427 atomic_inc(&entry->refs);
428 }
429 spin_unlock_irqrestore(&tree->lock, flags);
430 return ret == 0;
431}
432
433/* Needs to either be called under a log transaction or the log_mutex */
434void btrfs_get_logged_extents(struct inode *inode,
435 struct list_head *logged_list,
436 const loff_t start,
437 const loff_t end)
438{
439 struct btrfs_ordered_inode_tree *tree;
440 struct btrfs_ordered_extent *ordered;
441 struct rb_node *n;
442 struct rb_node *prev;
443
444 tree = &BTRFS_I(inode)->ordered_tree;
445 spin_lock_irq(&tree->lock);
446 n = __tree_search(&tree->tree, end, &prev);
447 if (!n)
448 n = prev;
449 for (; n; n = rb_prev(n)) {
450 ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
451 if (ordered->file_offset > end)
452 continue;
453 if (entry_end(ordered) <= start)
454 break;
455 if (test_and_set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
456 continue;
457 list_add(&ordered->log_list, logged_list);
458 atomic_inc(&ordered->refs);
459 }
460 spin_unlock_irq(&tree->lock);
461}
462
463void btrfs_put_logged_extents(struct list_head *logged_list)
464{
465 struct btrfs_ordered_extent *ordered;
466
467 while (!list_empty(logged_list)) {
468 ordered = list_first_entry(logged_list,
469 struct btrfs_ordered_extent,
470 log_list);
471 list_del_init(&ordered->log_list);
472 btrfs_put_ordered_extent(ordered);
473 }
474}
475
476void btrfs_submit_logged_extents(struct list_head *logged_list,
477 struct btrfs_root *log)
478{
479 int index = log->log_transid % 2;
480
481 spin_lock_irq(&log->log_extents_lock[index]);
482 list_splice_tail(logged_list, &log->logged_list[index]);
483 spin_unlock_irq(&log->log_extents_lock[index]);
484}
485
486void btrfs_wait_logged_extents(struct btrfs_trans_handle *trans,
487 struct btrfs_root *log, u64 transid)
488{
489 struct btrfs_ordered_extent *ordered;
490 int index = transid % 2;
491
492 spin_lock_irq(&log->log_extents_lock[index]);
493 while (!list_empty(&log->logged_list[index])) {
494 struct inode *inode;
495 ordered = list_first_entry(&log->logged_list[index],
496 struct btrfs_ordered_extent,
497 log_list);
498 list_del_init(&ordered->log_list);
499 inode = ordered->inode;
500 spin_unlock_irq(&log->log_extents_lock[index]);
501
502 if (!test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags) &&
503 !test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) {
504 u64 start = ordered->file_offset;
505 u64 end = ordered->file_offset + ordered->len - 1;
506
507 WARN_ON(!inode);
508 filemap_fdatawrite_range(inode->i_mapping, start, end);
509 }
510 wait_event(ordered->wait, test_bit(BTRFS_ORDERED_IO_DONE,
511 &ordered->flags));
512
513 /*
514 * In order to keep us from losing our ordered extent
515 * information when committing the transaction we have to make
516 * sure that any logged extents are completed when we go to
517 * commit the transaction. To do this we simply increase the
518 * current transactions pending_ordered counter and decrement it
519 * when the ordered extent completes.
520 */
521 if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
522 struct btrfs_ordered_inode_tree *tree;
523
524 tree = &BTRFS_I(inode)->ordered_tree;
525 spin_lock_irq(&tree->lock);
526 if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
527 set_bit(BTRFS_ORDERED_PENDING, &ordered->flags);
528 atomic_inc(&trans->transaction->pending_ordered);
529 }
530 spin_unlock_irq(&tree->lock);
531 }
532 btrfs_put_ordered_extent(ordered);
533 spin_lock_irq(&log->log_extents_lock[index]);
534 }
535 spin_unlock_irq(&log->log_extents_lock[index]);
536}
537
538void btrfs_free_logged_extents(struct btrfs_root *log, u64 transid)
539{
540 struct btrfs_ordered_extent *ordered;
541 int index = transid % 2;
542
543 spin_lock_irq(&log->log_extents_lock[index]);
544 while (!list_empty(&log->logged_list[index])) {
545 ordered = list_first_entry(&log->logged_list[index],
546 struct btrfs_ordered_extent,
547 log_list);
548 list_del_init(&ordered->log_list);
549 spin_unlock_irq(&log->log_extents_lock[index]);
550 btrfs_put_ordered_extent(ordered);
551 spin_lock_irq(&log->log_extents_lock[index]);
552 }
553 spin_unlock_irq(&log->log_extents_lock[index]);
554}
555
556/*
557 * used to drop a reference on an ordered extent. This will free
558 * the extent if the last reference is dropped
559 */
560void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
561{
562 struct list_head *cur;
563 struct btrfs_ordered_sum *sum;
564
565 trace_btrfs_ordered_extent_put(entry->inode, entry);
566
567 if (atomic_dec_and_test(&entry->refs)) {
568 ASSERT(list_empty(&entry->log_list));
569 ASSERT(list_empty(&entry->trans_list));
570 ASSERT(list_empty(&entry->root_extent_list));
571 ASSERT(RB_EMPTY_NODE(&entry->rb_node));
572 if (entry->inode)
573 btrfs_add_delayed_iput(entry->inode);
574 while (!list_empty(&entry->list)) {
575 cur = entry->list.next;
576 sum = list_entry(cur, struct btrfs_ordered_sum, list);
577 list_del(&sum->list);
578 kfree(sum);
579 }
580 kmem_cache_free(btrfs_ordered_extent_cache, entry);
581 }
582}
583
584/*
585 * remove an ordered extent from the tree. No references are dropped
586 * and waiters are woken up.
587 */
588void btrfs_remove_ordered_extent(struct inode *inode,
589 struct btrfs_ordered_extent *entry)
590{
591 struct btrfs_ordered_inode_tree *tree;
592 struct btrfs_root *root = BTRFS_I(inode)->root;
593 struct rb_node *node;
594 bool dec_pending_ordered = false;
595
596 tree = &BTRFS_I(inode)->ordered_tree;
597 spin_lock_irq(&tree->lock);
598 node = &entry->rb_node;
599 rb_erase(node, &tree->tree);
600 RB_CLEAR_NODE(node);
601 if (tree->last == node)
602 tree->last = NULL;
603 set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
604 if (test_and_clear_bit(BTRFS_ORDERED_PENDING, &entry->flags))
605 dec_pending_ordered = true;
606 spin_unlock_irq(&tree->lock);
607
608 /*
609 * The current running transaction is waiting on us, we need to let it
610 * know that we're complete and wake it up.
611 */
612 if (dec_pending_ordered) {
613 struct btrfs_transaction *trans;
614
615 /*
616 * The checks for trans are just a formality, it should be set,
617 * but if it isn't we don't want to deref/assert under the spin
618 * lock, so be nice and check if trans is set, but ASSERT() so
619 * if it isn't set a developer will notice.
620 */
621 spin_lock(&root->fs_info->trans_lock);
622 trans = root->fs_info->running_transaction;
623 if (trans)
624 atomic_inc(&trans->use_count);
625 spin_unlock(&root->fs_info->trans_lock);
626
627 ASSERT(trans);
628 if (trans) {
629 if (atomic_dec_and_test(&trans->pending_ordered))
630 wake_up(&trans->pending_wait);
631 btrfs_put_transaction(trans);
632 }
633 }
634
635 spin_lock(&root->ordered_extent_lock);
636 list_del_init(&entry->root_extent_list);
637 root->nr_ordered_extents--;
638
639 trace_btrfs_ordered_extent_remove(inode, entry);
640
641 if (!root->nr_ordered_extents) {
642 spin_lock(&root->fs_info->ordered_root_lock);
643 BUG_ON(list_empty(&root->ordered_root));
644 list_del_init(&root->ordered_root);
645 spin_unlock(&root->fs_info->ordered_root_lock);
646 }
647 spin_unlock(&root->ordered_extent_lock);
648 wake_up(&entry->wait);
649}
650
651static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
652{
653 struct btrfs_ordered_extent *ordered;
654
655 ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
656 btrfs_start_ordered_extent(ordered->inode, ordered, 1);
657 complete(&ordered->completion);
658}
659
660/*
661 * wait for all the ordered extents in a root. This is done when balancing
662 * space between drives.
663 */
664int btrfs_wait_ordered_extents(struct btrfs_root *root, int nr)
665{
666 struct list_head splice, works;
667 struct btrfs_ordered_extent *ordered, *next;
668 int count = 0;
669
670 INIT_LIST_HEAD(&splice);
671 INIT_LIST_HEAD(&works);
672
673 mutex_lock(&root->ordered_extent_mutex);
674 spin_lock(&root->ordered_extent_lock);
675 list_splice_init(&root->ordered_extents, &splice);
676 while (!list_empty(&splice) && nr) {
677 ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
678 root_extent_list);
679 list_move_tail(&ordered->root_extent_list,
680 &root->ordered_extents);
681 atomic_inc(&ordered->refs);
682 spin_unlock(&root->ordered_extent_lock);
683
684 btrfs_init_work(&ordered->flush_work,
685 btrfs_flush_delalloc_helper,
686 btrfs_run_ordered_extent_work, NULL, NULL);
687 list_add_tail(&ordered->work_list, &works);
688 btrfs_queue_work(root->fs_info->flush_workers,
689 &ordered->flush_work);
690
691 cond_resched();
692 spin_lock(&root->ordered_extent_lock);
693 if (nr != -1)
694 nr--;
695 count++;
696 }
697 list_splice_tail(&splice, &root->ordered_extents);
698 spin_unlock(&root->ordered_extent_lock);
699
700 list_for_each_entry_safe(ordered, next, &works, work_list) {
701 list_del_init(&ordered->work_list);
702 wait_for_completion(&ordered->completion);
703 btrfs_put_ordered_extent(ordered);
704 cond_resched();
705 }
706 mutex_unlock(&root->ordered_extent_mutex);
707
708 return count;
709}
710
711void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, int nr)
712{
713 struct btrfs_root *root;
714 struct list_head splice;
715 int done;
716
717 INIT_LIST_HEAD(&splice);
718
719 mutex_lock(&fs_info->ordered_operations_mutex);
720 spin_lock(&fs_info->ordered_root_lock);
721 list_splice_init(&fs_info->ordered_roots, &splice);
722 while (!list_empty(&splice) && nr) {
723 root = list_first_entry(&splice, struct btrfs_root,
724 ordered_root);
725 root = btrfs_grab_fs_root(root);
726 BUG_ON(!root);
727 list_move_tail(&root->ordered_root,
728 &fs_info->ordered_roots);
729 spin_unlock(&fs_info->ordered_root_lock);
730
731 done = btrfs_wait_ordered_extents(root, nr);
732 btrfs_put_fs_root(root);
733
734 spin_lock(&fs_info->ordered_root_lock);
735 if (nr != -1) {
736 nr -= done;
737 WARN_ON(nr < 0);
738 }
739 }
740 list_splice_tail(&splice, &fs_info->ordered_roots);
741 spin_unlock(&fs_info->ordered_root_lock);
742 mutex_unlock(&fs_info->ordered_operations_mutex);
743}
744
745/*
746 * Used to start IO or wait for a given ordered extent to finish.
747 *
748 * If wait is one, this effectively waits on page writeback for all the pages
749 * in the extent, and it waits on the io completion code to insert
750 * metadata into the btree corresponding to the extent
751 */
752void btrfs_start_ordered_extent(struct inode *inode,
753 struct btrfs_ordered_extent *entry,
754 int wait)
755{
756 u64 start = entry->file_offset;
757 u64 end = start + entry->len - 1;
758
759 trace_btrfs_ordered_extent_start(inode, entry);
760
761 /*
762 * pages in the range can be dirty, clean or writeback. We
763 * start IO on any dirty ones so the wait doesn't stall waiting
764 * for the flusher thread to find them
765 */
766 if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
767 filemap_fdatawrite_range(inode->i_mapping, start, end);
768 if (wait) {
769 wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
770 &entry->flags));
771 }
772}
773
774/*
775 * Used to wait on ordered extents across a large range of bytes.
776 */
777int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
778{
779 int ret = 0;
780 int ret_wb = 0;
781 u64 end;
782 u64 orig_end;
783 struct btrfs_ordered_extent *ordered;
784
785 if (start + len < start) {
786 orig_end = INT_LIMIT(loff_t);
787 } else {
788 orig_end = start + len - 1;
789 if (orig_end > INT_LIMIT(loff_t))
790 orig_end = INT_LIMIT(loff_t);
791 }
792
793 /* start IO across the range first to instantiate any delalloc
794 * extents
795 */
796 ret = btrfs_fdatawrite_range(inode, start, orig_end);
797 if (ret)
798 return ret;
799
800 /*
801 * If we have a writeback error don't return immediately. Wait first
802 * for any ordered extents that haven't completed yet. This is to make
803 * sure no one can dirty the same page ranges and call writepages()
804 * before the ordered extents complete - to avoid failures (-EEXIST)
805 * when adding the new ordered extents to the ordered tree.
806 */
807 ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
808
809 end = orig_end;
810 while (1) {
811 ordered = btrfs_lookup_first_ordered_extent(inode, end);
812 if (!ordered)
813 break;
814 if (ordered->file_offset > orig_end) {
815 btrfs_put_ordered_extent(ordered);
816 break;
817 }
818 if (ordered->file_offset + ordered->len <= start) {
819 btrfs_put_ordered_extent(ordered);
820 break;
821 }
822 btrfs_start_ordered_extent(inode, ordered, 1);
823 end = ordered->file_offset;
824 if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
825 ret = -EIO;
826 btrfs_put_ordered_extent(ordered);
827 if (ret || end == 0 || end == start)
828 break;
829 end--;
830 }
831 return ret_wb ? ret_wb : ret;
832}
833
834/*
835 * find an ordered extent corresponding to file_offset. return NULL if
836 * nothing is found, otherwise take a reference on the extent and return it
837 */
838struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
839 u64 file_offset)
840{
841 struct btrfs_ordered_inode_tree *tree;
842 struct rb_node *node;
843 struct btrfs_ordered_extent *entry = NULL;
844
845 tree = &BTRFS_I(inode)->ordered_tree;
846 spin_lock_irq(&tree->lock);
847 node = tree_search(tree, file_offset);
848 if (!node)
849 goto out;
850
851 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
852 if (!offset_in_entry(entry, file_offset))
853 entry = NULL;
854 if (entry)
855 atomic_inc(&entry->refs);
856out:
857 spin_unlock_irq(&tree->lock);
858 return entry;
859}
860
861/* Since the DIO code tries to lock a wide area we need to look for any ordered
862 * extents that exist in the range, rather than just the start of the range.
863 */
864struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode,
865 u64 file_offset,
866 u64 len)
867{
868 struct btrfs_ordered_inode_tree *tree;
869 struct rb_node *node;
870 struct btrfs_ordered_extent *entry = NULL;
871
872 tree = &BTRFS_I(inode)->ordered_tree;
873 spin_lock_irq(&tree->lock);
874 node = tree_search(tree, file_offset);
875 if (!node) {
876 node = tree_search(tree, file_offset + len);
877 if (!node)
878 goto out;
879 }
880
881 while (1) {
882 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
883 if (range_overlaps(entry, file_offset, len))
884 break;
885
886 if (entry->file_offset >= file_offset + len) {
887 entry = NULL;
888 break;
889 }
890 entry = NULL;
891 node = rb_next(node);
892 if (!node)
893 break;
894 }
895out:
896 if (entry)
897 atomic_inc(&entry->refs);
898 spin_unlock_irq(&tree->lock);
899 return entry;
900}
901
902bool btrfs_have_ordered_extents_in_range(struct inode *inode,
903 u64 file_offset,
904 u64 len)
905{
906 struct btrfs_ordered_extent *oe;
907
908 oe = btrfs_lookup_ordered_range(inode, file_offset, len);
909 if (oe) {
910 btrfs_put_ordered_extent(oe);
911 return true;
912 }
913 return false;
914}
915
916/*
917 * lookup and return any extent before 'file_offset'. NULL is returned
918 * if none is found
919 */
920struct btrfs_ordered_extent *
921btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset)
922{
923 struct btrfs_ordered_inode_tree *tree;
924 struct rb_node *node;
925 struct btrfs_ordered_extent *entry = NULL;
926
927 tree = &BTRFS_I(inode)->ordered_tree;
928 spin_lock_irq(&tree->lock);
929 node = tree_search(tree, file_offset);
930 if (!node)
931 goto out;
932
933 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
934 atomic_inc(&entry->refs);
935out:
936 spin_unlock_irq(&tree->lock);
937 return entry;
938}
939
940/*
941 * After an extent is done, call this to conditionally update the on disk
942 * i_size. i_size is updated to cover any fully written part of the file.
943 */
944int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
945 struct btrfs_ordered_extent *ordered)
946{
947 struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
948 u64 disk_i_size;
949 u64 new_i_size;
950 u64 i_size = i_size_read(inode);
951 struct rb_node *node;
952 struct rb_node *prev = NULL;
953 struct btrfs_ordered_extent *test;
954 int ret = 1;
955
956 spin_lock_irq(&tree->lock);
957 if (ordered) {
958 offset = entry_end(ordered);
959 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags))
960 offset = min(offset,
961 ordered->file_offset +
962 ordered->truncated_len);
963 } else {
964 offset = ALIGN(offset, BTRFS_I(inode)->root->sectorsize);
965 }
966 disk_i_size = BTRFS_I(inode)->disk_i_size;
967
968 /* truncate file */
969 if (disk_i_size > i_size) {
970 BTRFS_I(inode)->disk_i_size = i_size;
971 ret = 0;
972 goto out;
973 }
974
975 /*
976 * if the disk i_size is already at the inode->i_size, or
977 * this ordered extent is inside the disk i_size, we're done
978 */
979 if (disk_i_size == i_size)
980 goto out;
981
982 /*
983 * We still need to update disk_i_size if outstanding_isize is greater
984 * than disk_i_size.
985 */
986 if (offset <= disk_i_size &&
987 (!ordered || ordered->outstanding_isize <= disk_i_size))
988 goto out;
989
990 /*
991 * walk backward from this ordered extent to disk_i_size.
992 * if we find an ordered extent then we can't update disk i_size
993 * yet
994 */
995 if (ordered) {
996 node = rb_prev(&ordered->rb_node);
997 } else {
998 prev = tree_search(tree, offset);
999 /*
1000 * we insert file extents without involving ordered struct,
1001 * so there should be no ordered struct cover this offset
1002 */
1003 if (prev) {
1004 test = rb_entry(prev, struct btrfs_ordered_extent,
1005 rb_node);
1006 BUG_ON(offset_in_entry(test, offset));
1007 }
1008 node = prev;
1009 }
1010 for (; node; node = rb_prev(node)) {
1011 test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
1012
1013 /* We treat this entry as if it doesn't exist */
1014 if (test_bit(BTRFS_ORDERED_UPDATED_ISIZE, &test->flags))
1015 continue;
1016 if (test->file_offset + test->len <= disk_i_size)
1017 break;
1018 if (test->file_offset >= i_size)
1019 break;
1020 if (entry_end(test) > disk_i_size) {
1021 /*
1022 * we don't update disk_i_size now, so record this
1023 * undealt i_size. Or we will not know the real
1024 * i_size.
1025 */
1026 if (test->outstanding_isize < offset)
1027 test->outstanding_isize = offset;
1028 if (ordered &&
1029 ordered->outstanding_isize >
1030 test->outstanding_isize)
1031 test->outstanding_isize =
1032 ordered->outstanding_isize;
1033 goto out;
1034 }
1035 }
1036 new_i_size = min_t(u64, offset, i_size);
1037
1038 /*
1039 * Some ordered extents may completed before the current one, and
1040 * we hold the real i_size in ->outstanding_isize.
1041 */
1042 if (ordered && ordered->outstanding_isize > new_i_size)
1043 new_i_size = min_t(u64, ordered->outstanding_isize, i_size);
1044 BTRFS_I(inode)->disk_i_size = new_i_size;
1045 ret = 0;
1046out:
1047 /*
1048 * We need to do this because we can't remove ordered extents until
1049 * after the i_disk_size has been updated and then the inode has been
1050 * updated to reflect the change, so we need to tell anybody who finds
1051 * this ordered extent that we've already done all the real work, we
1052 * just haven't completed all the other work.
1053 */
1054 if (ordered)
1055 set_bit(BTRFS_ORDERED_UPDATED_ISIZE, &ordered->flags);
1056 spin_unlock_irq(&tree->lock);
1057 return ret;
1058}
1059
1060/*
1061 * search the ordered extents for one corresponding to 'offset' and
1062 * try to find a checksum. This is used because we allow pages to
1063 * be reclaimed before their checksum is actually put into the btree
1064 */
1065int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
1066 u32 *sum, int len)
1067{
1068 struct btrfs_ordered_sum *ordered_sum;
1069 struct btrfs_ordered_extent *ordered;
1070 struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
1071 unsigned long num_sectors;
1072 unsigned long i;
1073 u32 sectorsize = BTRFS_I(inode)->root->sectorsize;
1074 int index = 0;
1075
1076 ordered = btrfs_lookup_ordered_extent(inode, offset);
1077 if (!ordered)
1078 return 0;
1079
1080 spin_lock_irq(&tree->lock);
1081 list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
1082 if (disk_bytenr >= ordered_sum->bytenr &&
1083 disk_bytenr < ordered_sum->bytenr + ordered_sum->len) {
1084 i = (disk_bytenr - ordered_sum->bytenr) >>
1085 inode->i_sb->s_blocksize_bits;
1086 num_sectors = ordered_sum->len >>
1087 inode->i_sb->s_blocksize_bits;
1088 num_sectors = min_t(int, len - index, num_sectors - i);
1089 memcpy(sum + index, ordered_sum->sums + i,
1090 num_sectors);
1091
1092 index += (int)num_sectors;
1093 if (index == len)
1094 goto out;
1095 disk_bytenr += num_sectors * sectorsize;
1096 }
1097 }
1098out:
1099 spin_unlock_irq(&tree->lock);
1100 btrfs_put_ordered_extent(ordered);
1101 return index;
1102}
1103
1104int __init ordered_data_init(void)
1105{
1106 btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
1107 sizeof(struct btrfs_ordered_extent), 0,
1108 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
1109 NULL);
1110 if (!btrfs_ordered_extent_cache)
1111 return -ENOMEM;
1112
1113 return 0;
1114}
1115
1116void ordered_data_exit(void)
1117{
1118 kmem_cache_destroy(btrfs_ordered_extent_cache);
1119}