2e1a1694a33d1a7a51a0149015f48527a1044e38
[sfrench/cifs-2.6.git] / fs / btrfs / ordered-data.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2007 Oracle.  All rights reserved.
4  */
5
6 #include <linux/slab.h>
7 #include <linux/blkdev.h>
8 #include <linux/writeback.h>
9 #include <linux/pagevec.h>
10 #include "ctree.h"
11 #include "transaction.h"
12 #include "btrfs_inode.h"
13 #include "extent_io.h"
14 #include "disk-io.h"
15 #include "compression.h"
16
17 static struct kmem_cache *btrfs_ordered_extent_cache;
18
19 static u64 entry_end(struct btrfs_ordered_extent *entry)
20 {
21         if (entry->file_offset + entry->len < entry->file_offset)
22                 return (u64)-1;
23         return entry->file_offset + entry->len;
24 }
25
26 /* returns NULL if the insertion worked, or it returns the node it did find
27  * in the tree
28  */
29 static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
30                                    struct rb_node *node)
31 {
32         struct rb_node **p = &root->rb_node;
33         struct rb_node *parent = NULL;
34         struct btrfs_ordered_extent *entry;
35
36         while (*p) {
37                 parent = *p;
38                 entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
39
40                 if (file_offset < entry->file_offset)
41                         p = &(*p)->rb_left;
42                 else if (file_offset >= entry_end(entry))
43                         p = &(*p)->rb_right;
44                 else
45                         return parent;
46         }
47
48         rb_link_node(node, parent, p);
49         rb_insert_color(node, root);
50         return NULL;
51 }
52
53 static void ordered_data_tree_panic(struct inode *inode, int errno,
54                                                u64 offset)
55 {
56         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
57         btrfs_panic(fs_info, errno,
58                     "Inconsistency in ordered tree at offset %llu", offset);
59 }
60
61 /*
62  * look for a given offset in the tree, and if it can't be found return the
63  * first lesser offset
64  */
65 static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
66                                      struct rb_node **prev_ret)
67 {
68         struct rb_node *n = root->rb_node;
69         struct rb_node *prev = NULL;
70         struct rb_node *test;
71         struct btrfs_ordered_extent *entry;
72         struct btrfs_ordered_extent *prev_entry = NULL;
73
74         while (n) {
75                 entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
76                 prev = n;
77                 prev_entry = entry;
78
79                 if (file_offset < entry->file_offset)
80                         n = n->rb_left;
81                 else if (file_offset >= entry_end(entry))
82                         n = n->rb_right;
83                 else
84                         return n;
85         }
86         if (!prev_ret)
87                 return NULL;
88
89         while (prev && file_offset >= entry_end(prev_entry)) {
90                 test = rb_next(prev);
91                 if (!test)
92                         break;
93                 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
94                                       rb_node);
95                 if (file_offset < entry_end(prev_entry))
96                         break;
97
98                 prev = test;
99         }
100         if (prev)
101                 prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
102                                       rb_node);
103         while (prev && file_offset < entry_end(prev_entry)) {
104                 test = rb_prev(prev);
105                 if (!test)
106                         break;
107                 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
108                                       rb_node);
109                 prev = test;
110         }
111         *prev_ret = prev;
112         return NULL;
113 }
114
115 /*
116  * helper to check if a given offset is inside a given entry
117  */
118 static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset)
119 {
120         if (file_offset < entry->file_offset ||
121             entry->file_offset + entry->len <= file_offset)
122                 return 0;
123         return 1;
124 }
125
126 static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
127                           u64 len)
128 {
129         if (file_offset + len <= entry->file_offset ||
130             entry->file_offset + entry->len <= file_offset)
131                 return 0;
132         return 1;
133 }
134
135 /*
136  * look find the first ordered struct that has this offset, otherwise
137  * the first one less than this offset
138  */
139 static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
140                                           u64 file_offset)
141 {
142         struct rb_root *root = &tree->tree;
143         struct rb_node *prev = NULL;
144         struct rb_node *ret;
145         struct btrfs_ordered_extent *entry;
146
147         if (tree->last) {
148                 entry = rb_entry(tree->last, struct btrfs_ordered_extent,
149                                  rb_node);
150                 if (offset_in_entry(entry, file_offset))
151                         return tree->last;
152         }
153         ret = __tree_search(root, file_offset, &prev);
154         if (!ret)
155                 ret = prev;
156         if (ret)
157                 tree->last = ret;
158         return ret;
159 }
160
161 /* allocate and add a new ordered_extent into the per-inode tree.
162  * file_offset is the logical offset in the file
163  *
164  * start is the disk block number of an extent already reserved in the
165  * extent allocation tree
166  *
167  * len is the length of the extent
168  *
169  * The tree is given a single reference on the ordered extent that was
170  * inserted.
171  */
172 static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
173                                       u64 start, u64 len, u64 disk_len,
174                                       int type, int dio, int compress_type)
175 {
176         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
177         struct btrfs_root *root = BTRFS_I(inode)->root;
178         struct btrfs_ordered_inode_tree *tree;
179         struct rb_node *node;
180         struct btrfs_ordered_extent *entry;
181
182         tree = &BTRFS_I(inode)->ordered_tree;
183         entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
184         if (!entry)
185                 return -ENOMEM;
186
187         entry->file_offset = file_offset;
188         entry->start = start;
189         entry->len = len;
190         entry->disk_len = disk_len;
191         entry->bytes_left = len;
192         entry->inode = igrab(inode);
193         entry->compress_type = compress_type;
194         entry->truncated_len = (u64)-1;
195         if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
196                 set_bit(type, &entry->flags);
197
198         if (dio)
199                 set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
200
201         /* one ref for the tree */
202         refcount_set(&entry->refs, 1);
203         init_waitqueue_head(&entry->wait);
204         INIT_LIST_HEAD(&entry->list);
205         INIT_LIST_HEAD(&entry->root_extent_list);
206         INIT_LIST_HEAD(&entry->work_list);
207         init_completion(&entry->completion);
208         INIT_LIST_HEAD(&entry->log_list);
209         INIT_LIST_HEAD(&entry->trans_list);
210
211         trace_btrfs_ordered_extent_add(inode, entry);
212
213         spin_lock_irq(&tree->lock);
214         node = tree_insert(&tree->tree, file_offset,
215                            &entry->rb_node);
216         if (node)
217                 ordered_data_tree_panic(inode, -EEXIST, file_offset);
218         spin_unlock_irq(&tree->lock);
219
220         spin_lock(&root->ordered_extent_lock);
221         list_add_tail(&entry->root_extent_list,
222                       &root->ordered_extents);
223         root->nr_ordered_extents++;
224         if (root->nr_ordered_extents == 1) {
225                 spin_lock(&fs_info->ordered_root_lock);
226                 BUG_ON(!list_empty(&root->ordered_root));
227                 list_add_tail(&root->ordered_root, &fs_info->ordered_roots);
228                 spin_unlock(&fs_info->ordered_root_lock);
229         }
230         spin_unlock(&root->ordered_extent_lock);
231
232         /*
233          * We don't need the count_max_extents here, we can assume that all of
234          * that work has been done at higher layers, so this is truly the
235          * smallest the extent is going to get.
236          */
237         spin_lock(&BTRFS_I(inode)->lock);
238         btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
239         spin_unlock(&BTRFS_I(inode)->lock);
240
241         return 0;
242 }
243
244 int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
245                              u64 start, u64 len, u64 disk_len, int type)
246 {
247         return __btrfs_add_ordered_extent(inode, file_offset, start, len,
248                                           disk_len, type, 0,
249                                           BTRFS_COMPRESS_NONE);
250 }
251
252 int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
253                                  u64 start, u64 len, u64 disk_len, int type)
254 {
255         return __btrfs_add_ordered_extent(inode, file_offset, start, len,
256                                           disk_len, type, 1,
257                                           BTRFS_COMPRESS_NONE);
258 }
259
260 int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
261                                       u64 start, u64 len, u64 disk_len,
262                                       int type, int compress_type)
263 {
264         return __btrfs_add_ordered_extent(inode, file_offset, start, len,
265                                           disk_len, type, 0,
266                                           compress_type);
267 }
268
269 /*
270  * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
271  * when an ordered extent is finished.  If the list covers more than one
272  * ordered extent, it is split across multiples.
273  */
274 void btrfs_add_ordered_sum(struct inode *inode,
275                            struct btrfs_ordered_extent *entry,
276                            struct btrfs_ordered_sum *sum)
277 {
278         struct btrfs_ordered_inode_tree *tree;
279
280         tree = &BTRFS_I(inode)->ordered_tree;
281         spin_lock_irq(&tree->lock);
282         list_add_tail(&sum->list, &entry->list);
283         spin_unlock_irq(&tree->lock);
284 }
285
286 /*
287  * this is used to account for finished IO across a given range
288  * of the file.  The IO may span ordered extents.  If
289  * a given ordered_extent is completely done, 1 is returned, otherwise
290  * 0.
291  *
292  * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
293  * to make sure this function only returns 1 once for a given ordered extent.
294  *
295  * file_offset is updated to one byte past the range that is recorded as
296  * complete.  This allows you to walk forward in the file.
297  */
298 int btrfs_dec_test_first_ordered_pending(struct inode *inode,
299                                    struct btrfs_ordered_extent **cached,
300                                    u64 *file_offset, u64 io_size, int uptodate)
301 {
302         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
303         struct btrfs_ordered_inode_tree *tree;
304         struct rb_node *node;
305         struct btrfs_ordered_extent *entry = NULL;
306         int ret;
307         unsigned long flags;
308         u64 dec_end;
309         u64 dec_start;
310         u64 to_dec;
311
312         tree = &BTRFS_I(inode)->ordered_tree;
313         spin_lock_irqsave(&tree->lock, flags);
314         node = tree_search(tree, *file_offset);
315         if (!node) {
316                 ret = 1;
317                 goto out;
318         }
319
320         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
321         if (!offset_in_entry(entry, *file_offset)) {
322                 ret = 1;
323                 goto out;
324         }
325
326         dec_start = max(*file_offset, entry->file_offset);
327         dec_end = min(*file_offset + io_size, entry->file_offset +
328                       entry->len);
329         *file_offset = dec_end;
330         if (dec_start > dec_end) {
331                 btrfs_crit(fs_info, "bad ordering dec_start %llu end %llu",
332                            dec_start, dec_end);
333         }
334         to_dec = dec_end - dec_start;
335         if (to_dec > entry->bytes_left) {
336                 btrfs_crit(fs_info,
337                            "bad ordered accounting left %llu size %llu",
338                            entry->bytes_left, to_dec);
339         }
340         entry->bytes_left -= to_dec;
341         if (!uptodate)
342                 set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
343
344         if (entry->bytes_left == 0) {
345                 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
346                 /* test_and_set_bit implies a barrier */
347                 cond_wake_up_nomb(&entry->wait);
348         } else {
349                 ret = 1;
350         }
351 out:
352         if (!ret && cached && entry) {
353                 *cached = entry;
354                 refcount_inc(&entry->refs);
355         }
356         spin_unlock_irqrestore(&tree->lock, flags);
357         return ret == 0;
358 }
359
360 /*
361  * this is used to account for finished IO across a given range
362  * of the file.  The IO should not span ordered extents.  If
363  * a given ordered_extent is completely done, 1 is returned, otherwise
364  * 0.
365  *
366  * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
367  * to make sure this function only returns 1 once for a given ordered extent.
368  */
369 int btrfs_dec_test_ordered_pending(struct inode *inode,
370                                    struct btrfs_ordered_extent **cached,
371                                    u64 file_offset, u64 io_size, int uptodate)
372 {
373         struct btrfs_ordered_inode_tree *tree;
374         struct rb_node *node;
375         struct btrfs_ordered_extent *entry = NULL;
376         unsigned long flags;
377         int ret;
378
379         tree = &BTRFS_I(inode)->ordered_tree;
380         spin_lock_irqsave(&tree->lock, flags);
381         if (cached && *cached) {
382                 entry = *cached;
383                 goto have_entry;
384         }
385
386         node = tree_search(tree, file_offset);
387         if (!node) {
388                 ret = 1;
389                 goto out;
390         }
391
392         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
393 have_entry:
394         if (!offset_in_entry(entry, file_offset)) {
395                 ret = 1;
396                 goto out;
397         }
398
399         if (io_size > entry->bytes_left) {
400                 btrfs_crit(BTRFS_I(inode)->root->fs_info,
401                            "bad ordered accounting left %llu size %llu",
402                        entry->bytes_left, io_size);
403         }
404         entry->bytes_left -= io_size;
405         if (!uptodate)
406                 set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
407
408         if (entry->bytes_left == 0) {
409                 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
410                 /* test_and_set_bit implies a barrier */
411                 cond_wake_up_nomb(&entry->wait);
412         } else {
413                 ret = 1;
414         }
415 out:
416         if (!ret && cached && entry) {
417                 *cached = entry;
418                 refcount_inc(&entry->refs);
419         }
420         spin_unlock_irqrestore(&tree->lock, flags);
421         return ret == 0;
422 }
423
424 /* Needs to either be called under a log transaction or the log_mutex */
425 void btrfs_get_logged_extents(struct btrfs_inode *inode,
426                               struct list_head *logged_list,
427                               const loff_t start,
428                               const loff_t end)
429 {
430         struct btrfs_ordered_inode_tree *tree;
431         struct btrfs_ordered_extent *ordered;
432         struct rb_node *n;
433         struct rb_node *prev;
434
435         tree = &inode->ordered_tree;
436         spin_lock_irq(&tree->lock);
437         n = __tree_search(&tree->tree, end, &prev);
438         if (!n)
439                 n = prev;
440         for (; n; n = rb_prev(n)) {
441                 ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
442                 if (ordered->file_offset > end)
443                         continue;
444                 if (entry_end(ordered) <= start)
445                         break;
446                 if (test_and_set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
447                         continue;
448                 list_add(&ordered->log_list, logged_list);
449                 refcount_inc(&ordered->refs);
450         }
451         spin_unlock_irq(&tree->lock);
452 }
453
454 void btrfs_put_logged_extents(struct list_head *logged_list)
455 {
456         struct btrfs_ordered_extent *ordered;
457
458         while (!list_empty(logged_list)) {
459                 ordered = list_first_entry(logged_list,
460                                            struct btrfs_ordered_extent,
461                                            log_list);
462                 list_del_init(&ordered->log_list);
463                 btrfs_put_ordered_extent(ordered);
464         }
465 }
466
467 void btrfs_submit_logged_extents(struct list_head *logged_list,
468                                  struct btrfs_root *log)
469 {
470         int index = log->log_transid % 2;
471
472         spin_lock_irq(&log->log_extents_lock[index]);
473         list_splice_tail(logged_list, &log->logged_list[index]);
474         spin_unlock_irq(&log->log_extents_lock[index]);
475 }
476
477 void btrfs_wait_logged_extents(struct btrfs_trans_handle *trans,
478                                struct btrfs_root *log, u64 transid)
479 {
480         struct btrfs_ordered_extent *ordered;
481         int index = transid % 2;
482
483         spin_lock_irq(&log->log_extents_lock[index]);
484         while (!list_empty(&log->logged_list[index])) {
485                 struct inode *inode;
486                 ordered = list_first_entry(&log->logged_list[index],
487                                            struct btrfs_ordered_extent,
488                                            log_list);
489                 list_del_init(&ordered->log_list);
490                 inode = ordered->inode;
491                 spin_unlock_irq(&log->log_extents_lock[index]);
492
493                 if (!test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags) &&
494                     !test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) {
495                         u64 start = ordered->file_offset;
496                         u64 end = ordered->file_offset + ordered->len - 1;
497
498                         WARN_ON(!inode);
499                         filemap_fdatawrite_range(inode->i_mapping, start, end);
500                 }
501                 wait_event(ordered->wait, test_bit(BTRFS_ORDERED_IO_DONE,
502                                                    &ordered->flags));
503
504                 /*
505                  * In order to keep us from losing our ordered extent
506                  * information when committing the transaction we have to make
507                  * sure that any logged extents are completed when we go to
508                  * commit the transaction.  To do this we simply increase the
509                  * current transactions pending_ordered counter and decrement it
510                  * when the ordered extent completes.
511                  */
512                 if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
513                         struct btrfs_ordered_inode_tree *tree;
514
515                         tree = &BTRFS_I(inode)->ordered_tree;
516                         spin_lock_irq(&tree->lock);
517                         if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
518                                 set_bit(BTRFS_ORDERED_PENDING, &ordered->flags);
519                                 atomic_inc(&trans->transaction->pending_ordered);
520                         }
521                         spin_unlock_irq(&tree->lock);
522                 }
523                 btrfs_put_ordered_extent(ordered);
524                 spin_lock_irq(&log->log_extents_lock[index]);
525         }
526         spin_unlock_irq(&log->log_extents_lock[index]);
527 }
528
529 void btrfs_free_logged_extents(struct btrfs_root *log, u64 transid)
530 {
531         struct btrfs_ordered_extent *ordered;
532         int index = transid % 2;
533
534         spin_lock_irq(&log->log_extents_lock[index]);
535         while (!list_empty(&log->logged_list[index])) {
536                 ordered = list_first_entry(&log->logged_list[index],
537                                            struct btrfs_ordered_extent,
538                                            log_list);
539                 list_del_init(&ordered->log_list);
540                 spin_unlock_irq(&log->log_extents_lock[index]);
541                 btrfs_put_ordered_extent(ordered);
542                 spin_lock_irq(&log->log_extents_lock[index]);
543         }
544         spin_unlock_irq(&log->log_extents_lock[index]);
545 }
546
547 /*
548  * used to drop a reference on an ordered extent.  This will free
549  * the extent if the last reference is dropped
550  */
551 void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
552 {
553         struct list_head *cur;
554         struct btrfs_ordered_sum *sum;
555
556         trace_btrfs_ordered_extent_put(entry->inode, entry);
557
558         if (refcount_dec_and_test(&entry->refs)) {
559                 ASSERT(list_empty(&entry->log_list));
560                 ASSERT(list_empty(&entry->trans_list));
561                 ASSERT(list_empty(&entry->root_extent_list));
562                 ASSERT(RB_EMPTY_NODE(&entry->rb_node));
563                 if (entry->inode)
564                         btrfs_add_delayed_iput(entry->inode);
565                 while (!list_empty(&entry->list)) {
566                         cur = entry->list.next;
567                         sum = list_entry(cur, struct btrfs_ordered_sum, list);
568                         list_del(&sum->list);
569                         kfree(sum);
570                 }
571                 kmem_cache_free(btrfs_ordered_extent_cache, entry);
572         }
573 }
574
575 /*
576  * remove an ordered extent from the tree.  No references are dropped
577  * and waiters are woken up.
578  */
579 void btrfs_remove_ordered_extent(struct inode *inode,
580                                  struct btrfs_ordered_extent *entry)
581 {
582         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
583         struct btrfs_ordered_inode_tree *tree;
584         struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
585         struct btrfs_root *root = btrfs_inode->root;
586         struct rb_node *node;
587         bool dec_pending_ordered = false;
588
589         /* This is paired with btrfs_add_ordered_extent. */
590         spin_lock(&btrfs_inode->lock);
591         btrfs_mod_outstanding_extents(btrfs_inode, -1);
592         spin_unlock(&btrfs_inode->lock);
593         if (root != fs_info->tree_root)
594                 btrfs_delalloc_release_metadata(btrfs_inode, entry->len, false);
595
596         tree = &btrfs_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(&fs_info->trans_lock);
622                 trans = fs_info->running_transaction;
623                 if (trans)
624                         refcount_inc(&trans->use_count);
625                 spin_unlock(&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(&fs_info->ordered_root_lock);
643                 BUG_ON(list_empty(&root->ordered_root));
644                 list_del_init(&root->ordered_root);
645                 spin_unlock(&fs_info->ordered_root_lock);
646         }
647         spin_unlock(&root->ordered_extent_lock);
648         wake_up(&entry->wait);
649 }
650
651 static 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  */
664 u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
665                                const u64 range_start, const u64 range_len)
666 {
667         struct btrfs_fs_info *fs_info = root->fs_info;
668         LIST_HEAD(splice);
669         LIST_HEAD(skipped);
670         LIST_HEAD(works);
671         struct btrfs_ordered_extent *ordered, *next;
672         u64 count = 0;
673         const u64 range_end = range_start + range_len;
674
675         mutex_lock(&root->ordered_extent_mutex);
676         spin_lock(&root->ordered_extent_lock);
677         list_splice_init(&root->ordered_extents, &splice);
678         while (!list_empty(&splice) && nr) {
679                 ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
680                                            root_extent_list);
681
682                 if (range_end <= ordered->start ||
683                     ordered->start + ordered->disk_len <= range_start) {
684                         list_move_tail(&ordered->root_extent_list, &skipped);
685                         cond_resched_lock(&root->ordered_extent_lock);
686                         continue;
687                 }
688
689                 list_move_tail(&ordered->root_extent_list,
690                                &root->ordered_extents);
691                 refcount_inc(&ordered->refs);
692                 spin_unlock(&root->ordered_extent_lock);
693
694                 btrfs_init_work(&ordered->flush_work,
695                                 btrfs_flush_delalloc_helper,
696                                 btrfs_run_ordered_extent_work, NULL, NULL);
697                 list_add_tail(&ordered->work_list, &works);
698                 btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work);
699
700                 cond_resched();
701                 spin_lock(&root->ordered_extent_lock);
702                 if (nr != U64_MAX)
703                         nr--;
704                 count++;
705         }
706         list_splice_tail(&skipped, &root->ordered_extents);
707         list_splice_tail(&splice, &root->ordered_extents);
708         spin_unlock(&root->ordered_extent_lock);
709
710         list_for_each_entry_safe(ordered, next, &works, work_list) {
711                 list_del_init(&ordered->work_list);
712                 wait_for_completion(&ordered->completion);
713                 btrfs_put_ordered_extent(ordered);
714                 cond_resched();
715         }
716         mutex_unlock(&root->ordered_extent_mutex);
717
718         return count;
719 }
720
721 u64 btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
722                              const u64 range_start, const u64 range_len)
723 {
724         struct btrfs_root *root;
725         struct list_head splice;
726         u64 total_done = 0;
727         u64 done;
728
729         INIT_LIST_HEAD(&splice);
730
731         mutex_lock(&fs_info->ordered_operations_mutex);
732         spin_lock(&fs_info->ordered_root_lock);
733         list_splice_init(&fs_info->ordered_roots, &splice);
734         while (!list_empty(&splice) && nr) {
735                 root = list_first_entry(&splice, struct btrfs_root,
736                                         ordered_root);
737                 root = btrfs_grab_fs_root(root);
738                 BUG_ON(!root);
739                 list_move_tail(&root->ordered_root,
740                                &fs_info->ordered_roots);
741                 spin_unlock(&fs_info->ordered_root_lock);
742
743                 done = btrfs_wait_ordered_extents(root, nr,
744                                                   range_start, range_len);
745                 btrfs_put_fs_root(root);
746                 total_done += done;
747
748                 spin_lock(&fs_info->ordered_root_lock);
749                 if (nr != U64_MAX) {
750                         nr -= done;
751                 }
752         }
753         list_splice_tail(&splice, &fs_info->ordered_roots);
754         spin_unlock(&fs_info->ordered_root_lock);
755         mutex_unlock(&fs_info->ordered_operations_mutex);
756
757         return total_done;
758 }
759
760 /*
761  * Used to start IO or wait for a given ordered extent to finish.
762  *
763  * If wait is one, this effectively waits on page writeback for all the pages
764  * in the extent, and it waits on the io completion code to insert
765  * metadata into the btree corresponding to the extent
766  */
767 void btrfs_start_ordered_extent(struct inode *inode,
768                                        struct btrfs_ordered_extent *entry,
769                                        int wait)
770 {
771         u64 start = entry->file_offset;
772         u64 end = start + entry->len - 1;
773
774         trace_btrfs_ordered_extent_start(inode, entry);
775
776         /*
777          * pages in the range can be dirty, clean or writeback.  We
778          * start IO on any dirty ones so the wait doesn't stall waiting
779          * for the flusher thread to find them
780          */
781         if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
782                 filemap_fdatawrite_range(inode->i_mapping, start, end);
783         if (wait) {
784                 wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
785                                                  &entry->flags));
786         }
787 }
788
789 /*
790  * Used to wait on ordered extents across a large range of bytes.
791  */
792 int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
793 {
794         int ret = 0;
795         int ret_wb = 0;
796         u64 end;
797         u64 orig_end;
798         struct btrfs_ordered_extent *ordered;
799
800         if (start + len < start) {
801                 orig_end = INT_LIMIT(loff_t);
802         } else {
803                 orig_end = start + len - 1;
804                 if (orig_end > INT_LIMIT(loff_t))
805                         orig_end = INT_LIMIT(loff_t);
806         }
807
808         /* start IO across the range first to instantiate any delalloc
809          * extents
810          */
811         ret = btrfs_fdatawrite_range(inode, start, orig_end);
812         if (ret)
813                 return ret;
814
815         /*
816          * If we have a writeback error don't return immediately. Wait first
817          * for any ordered extents that haven't completed yet. This is to make
818          * sure no one can dirty the same page ranges and call writepages()
819          * before the ordered extents complete - to avoid failures (-EEXIST)
820          * when adding the new ordered extents to the ordered tree.
821          */
822         ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
823
824         end = orig_end;
825         while (1) {
826                 ordered = btrfs_lookup_first_ordered_extent(inode, end);
827                 if (!ordered)
828                         break;
829                 if (ordered->file_offset > orig_end) {
830                         btrfs_put_ordered_extent(ordered);
831                         break;
832                 }
833                 if (ordered->file_offset + ordered->len <= start) {
834                         btrfs_put_ordered_extent(ordered);
835                         break;
836                 }
837                 btrfs_start_ordered_extent(inode, ordered, 1);
838                 end = ordered->file_offset;
839                 if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
840                         ret = -EIO;
841                 btrfs_put_ordered_extent(ordered);
842                 if (ret || end == 0 || end == start)
843                         break;
844                 end--;
845         }
846         return ret_wb ? ret_wb : ret;
847 }
848
849 /*
850  * find an ordered extent corresponding to file_offset.  return NULL if
851  * nothing is found, otherwise take a reference on the extent and return it
852  */
853 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
854                                                          u64 file_offset)
855 {
856         struct btrfs_ordered_inode_tree *tree;
857         struct rb_node *node;
858         struct btrfs_ordered_extent *entry = NULL;
859
860         tree = &BTRFS_I(inode)->ordered_tree;
861         spin_lock_irq(&tree->lock);
862         node = tree_search(tree, file_offset);
863         if (!node)
864                 goto out;
865
866         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
867         if (!offset_in_entry(entry, file_offset))
868                 entry = NULL;
869         if (entry)
870                 refcount_inc(&entry->refs);
871 out:
872         spin_unlock_irq(&tree->lock);
873         return entry;
874 }
875
876 /* Since the DIO code tries to lock a wide area we need to look for any ordered
877  * extents that exist in the range, rather than just the start of the range.
878  */
879 struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
880                 struct btrfs_inode *inode, u64 file_offset, u64 len)
881 {
882         struct btrfs_ordered_inode_tree *tree;
883         struct rb_node *node;
884         struct btrfs_ordered_extent *entry = NULL;
885
886         tree = &inode->ordered_tree;
887         spin_lock_irq(&tree->lock);
888         node = tree_search(tree, file_offset);
889         if (!node) {
890                 node = tree_search(tree, file_offset + len);
891                 if (!node)
892                         goto out;
893         }
894
895         while (1) {
896                 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
897                 if (range_overlaps(entry, file_offset, len))
898                         break;
899
900                 if (entry->file_offset >= file_offset + len) {
901                         entry = NULL;
902                         break;
903                 }
904                 entry = NULL;
905                 node = rb_next(node);
906                 if (!node)
907                         break;
908         }
909 out:
910         if (entry)
911                 refcount_inc(&entry->refs);
912         spin_unlock_irq(&tree->lock);
913         return entry;
914 }
915
916 bool btrfs_have_ordered_extents_in_range(struct inode *inode,
917                                          u64 file_offset,
918                                          u64 len)
919 {
920         struct btrfs_ordered_extent *oe;
921
922         oe = btrfs_lookup_ordered_range(BTRFS_I(inode), file_offset, len);
923         if (oe) {
924                 btrfs_put_ordered_extent(oe);
925                 return true;
926         }
927         return false;
928 }
929
930 /*
931  * lookup and return any extent before 'file_offset'.  NULL is returned
932  * if none is found
933  */
934 struct btrfs_ordered_extent *
935 btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset)
936 {
937         struct btrfs_ordered_inode_tree *tree;
938         struct rb_node *node;
939         struct btrfs_ordered_extent *entry = NULL;
940
941         tree = &BTRFS_I(inode)->ordered_tree;
942         spin_lock_irq(&tree->lock);
943         node = tree_search(tree, file_offset);
944         if (!node)
945                 goto out;
946
947         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
948         refcount_inc(&entry->refs);
949 out:
950         spin_unlock_irq(&tree->lock);
951         return entry;
952 }
953
954 /*
955  * After an extent is done, call this to conditionally update the on disk
956  * i_size.  i_size is updated to cover any fully written part of the file.
957  */
958 int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
959                                 struct btrfs_ordered_extent *ordered)
960 {
961         struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
962         u64 disk_i_size;
963         u64 new_i_size;
964         u64 i_size = i_size_read(inode);
965         struct rb_node *node;
966         struct rb_node *prev = NULL;
967         struct btrfs_ordered_extent *test;
968         int ret = 1;
969         u64 orig_offset = offset;
970
971         spin_lock_irq(&tree->lock);
972         if (ordered) {
973                 offset = entry_end(ordered);
974                 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags))
975                         offset = min(offset,
976                                      ordered->file_offset +
977                                      ordered->truncated_len);
978         } else {
979                 offset = ALIGN(offset, btrfs_inode_sectorsize(inode));
980         }
981         disk_i_size = BTRFS_I(inode)->disk_i_size;
982
983         /*
984          * truncate file.
985          * If ordered is not NULL, then this is called from endio and
986          * disk_i_size will be updated by either truncate itself or any
987          * in-flight IOs which are inside the disk_i_size.
988          *
989          * Because btrfs_setsize() may set i_size with disk_i_size if truncate
990          * fails somehow, we need to make sure we have a precise disk_i_size by
991          * updating it as usual.
992          *
993          */
994         if (!ordered && disk_i_size > i_size) {
995                 BTRFS_I(inode)->disk_i_size = orig_offset;
996                 ret = 0;
997                 goto out;
998         }
999
1000         /*
1001          * if the disk i_size is already at the inode->i_size, or
1002          * this ordered extent is inside the disk i_size, we're done
1003          */
1004         if (disk_i_size == i_size)
1005                 goto out;
1006
1007         /*
1008          * We still need to update disk_i_size if outstanding_isize is greater
1009          * than disk_i_size.
1010          */
1011         if (offset <= disk_i_size &&
1012             (!ordered || ordered->outstanding_isize <= disk_i_size))
1013                 goto out;
1014
1015         /*
1016          * walk backward from this ordered extent to disk_i_size.
1017          * if we find an ordered extent then we can't update disk i_size
1018          * yet
1019          */
1020         if (ordered) {
1021                 node = rb_prev(&ordered->rb_node);
1022         } else {
1023                 prev = tree_search(tree, offset);
1024                 /*
1025                  * we insert file extents without involving ordered struct,
1026                  * so there should be no ordered struct cover this offset
1027                  */
1028                 if (prev) {
1029                         test = rb_entry(prev, struct btrfs_ordered_extent,
1030                                         rb_node);
1031                         BUG_ON(offset_in_entry(test, offset));
1032                 }
1033                 node = prev;
1034         }
1035         for (; node; node = rb_prev(node)) {
1036                 test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
1037
1038                 /* We treat this entry as if it doesn't exist */
1039                 if (test_bit(BTRFS_ORDERED_UPDATED_ISIZE, &test->flags))
1040                         continue;
1041
1042                 if (entry_end(test) <= disk_i_size)
1043                         break;
1044                 if (test->file_offset >= i_size)
1045                         break;
1046
1047                 /*
1048                  * We don't update disk_i_size now, so record this undealt
1049                  * i_size. Or we will not know the real i_size.
1050                  */
1051                 if (test->outstanding_isize < offset)
1052                         test->outstanding_isize = offset;
1053                 if (ordered &&
1054                     ordered->outstanding_isize > test->outstanding_isize)
1055                         test->outstanding_isize = ordered->outstanding_isize;
1056                 goto out;
1057         }
1058         new_i_size = min_t(u64, offset, i_size);
1059
1060         /*
1061          * Some ordered extents may completed before the current one, and
1062          * we hold the real i_size in ->outstanding_isize.
1063          */
1064         if (ordered && ordered->outstanding_isize > new_i_size)
1065                 new_i_size = min_t(u64, ordered->outstanding_isize, i_size);
1066         BTRFS_I(inode)->disk_i_size = new_i_size;
1067         ret = 0;
1068 out:
1069         /*
1070          * We need to do this because we can't remove ordered extents until
1071          * after the i_disk_size has been updated and then the inode has been
1072          * updated to reflect the change, so we need to tell anybody who finds
1073          * this ordered extent that we've already done all the real work, we
1074          * just haven't completed all the other work.
1075          */
1076         if (ordered)
1077                 set_bit(BTRFS_ORDERED_UPDATED_ISIZE, &ordered->flags);
1078         spin_unlock_irq(&tree->lock);
1079         return ret;
1080 }
1081
1082 /*
1083  * search the ordered extents for one corresponding to 'offset' and
1084  * try to find a checksum.  This is used because we allow pages to
1085  * be reclaimed before their checksum is actually put into the btree
1086  */
1087 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
1088                            u32 *sum, int len)
1089 {
1090         struct btrfs_ordered_sum *ordered_sum;
1091         struct btrfs_ordered_extent *ordered;
1092         struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
1093         unsigned long num_sectors;
1094         unsigned long i;
1095         u32 sectorsize = btrfs_inode_sectorsize(inode);
1096         int index = 0;
1097
1098         ordered = btrfs_lookup_ordered_extent(inode, offset);
1099         if (!ordered)
1100                 return 0;
1101
1102         spin_lock_irq(&tree->lock);
1103         list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
1104                 if (disk_bytenr >= ordered_sum->bytenr &&
1105                     disk_bytenr < ordered_sum->bytenr + ordered_sum->len) {
1106                         i = (disk_bytenr - ordered_sum->bytenr) >>
1107                             inode->i_sb->s_blocksize_bits;
1108                         num_sectors = ordered_sum->len >>
1109                                       inode->i_sb->s_blocksize_bits;
1110                         num_sectors = min_t(int, len - index, num_sectors - i);
1111                         memcpy(sum + index, ordered_sum->sums + i,
1112                                num_sectors);
1113
1114                         index += (int)num_sectors;
1115                         if (index == len)
1116                                 goto out;
1117                         disk_bytenr += num_sectors * sectorsize;
1118                 }
1119         }
1120 out:
1121         spin_unlock_irq(&tree->lock);
1122         btrfs_put_ordered_extent(ordered);
1123         return index;
1124 }
1125
1126 int __init ordered_data_init(void)
1127 {
1128         btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
1129                                      sizeof(struct btrfs_ordered_extent), 0,
1130                                      SLAB_MEM_SPREAD,
1131                                      NULL);
1132         if (!btrfs_ordered_extent_cache)
1133                 return -ENOMEM;
1134
1135         return 0;
1136 }
1137
1138 void __cold ordered_data_exit(void)
1139 {
1140         kmem_cache_destroy(btrfs_ordered_extent_cache);
1141 }