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/sched/mm.h>
 
 10#include "misc.h"
 11#include "ctree.h"
 12#include "transaction.h"
 13#include "btrfs_inode.h"
 14#include "extent_io.h"
 15#include "disk-io.h"
 16#include "compression.h"
 17#include "delalloc-space.h"
 18#include "qgroup.h"
 
 
 19
 20static struct kmem_cache *btrfs_ordered_extent_cache;
 21
 22static u64 entry_end(struct btrfs_ordered_extent *entry)
 23{
 24	if (entry->file_offset + entry->num_bytes < entry->file_offset)
 25		return (u64)-1;
 26	return entry->file_offset + entry->num_bytes;
 27}
 28
 29/* returns NULL if the insertion worked, or it returns the node it did find
 30 * in the tree
 31 */
 32static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
 33				   struct rb_node *node)
 34{
 35	struct rb_node **p = &root->rb_node;
 36	struct rb_node *parent = NULL;
 37	struct btrfs_ordered_extent *entry;
 38
 39	while (*p) {
 40		parent = *p;
 41		entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
 42
 43		if (file_offset < entry->file_offset)
 44			p = &(*p)->rb_left;
 45		else if (file_offset >= entry_end(entry))
 46			p = &(*p)->rb_right;
 47		else
 48			return parent;
 49	}
 50
 51	rb_link_node(node, parent, p);
 52	rb_insert_color(node, root);
 53	return NULL;
 54}
 55
 56/*
 57 * look for a given offset in the tree, and if it can't be found return the
 58 * first lesser offset
 59 */
 60static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
 61				     struct rb_node **prev_ret)
 62{
 63	struct rb_node *n = root->rb_node;
 64	struct rb_node *prev = NULL;
 65	struct rb_node *test;
 66	struct btrfs_ordered_extent *entry;
 67	struct btrfs_ordered_extent *prev_entry = NULL;
 68
 69	while (n) {
 70		entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
 71		prev = n;
 72		prev_entry = entry;
 73
 74		if (file_offset < entry->file_offset)
 75			n = n->rb_left;
 76		else if (file_offset >= entry_end(entry))
 77			n = n->rb_right;
 78		else
 79			return n;
 80	}
 81	if (!prev_ret)
 82		return NULL;
 83
 84	while (prev && file_offset >= entry_end(prev_entry)) {
 85		test = rb_next(prev);
 86		if (!test)
 87			break;
 88		prev_entry = rb_entry(test, struct btrfs_ordered_extent,
 89				      rb_node);
 90		if (file_offset < entry_end(prev_entry))
 91			break;
 92
 93		prev = test;
 94	}
 95	if (prev)
 96		prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
 97				      rb_node);
 98	while (prev && file_offset < entry_end(prev_entry)) {
 99		test = rb_prev(prev);
100		if (!test)
101			break;
102		prev_entry = rb_entry(test, struct btrfs_ordered_extent,
103				      rb_node);
104		prev = test;
105	}
106	*prev_ret = prev;
107	return NULL;
108}
109
110/*
111 * helper to check if a given offset is inside a given entry
112 */
113static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset)
114{
115	if (file_offset < entry->file_offset ||
116	    entry->file_offset + entry->num_bytes <= file_offset)
117		return 0;
118	return 1;
119}
120
121static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
122			  u64 len)
123{
124	if (file_offset + len <= entry->file_offset ||
125	    entry->file_offset + entry->num_bytes <= file_offset)
126		return 0;
127	return 1;
128}
129
130/*
131 * look find the first ordered struct that has this offset, otherwise
132 * the first one less than this offset
133 */
134static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
135					  u64 file_offset)
136{
137	struct rb_root *root = &tree->tree;
138	struct rb_node *prev = NULL;
139	struct rb_node *ret;
140	struct btrfs_ordered_extent *entry;
141
142	if (tree->last) {
143		entry = rb_entry(tree->last, struct btrfs_ordered_extent,
144				 rb_node);
145		if (offset_in_entry(entry, file_offset))
146			return tree->last;
147	}
148	ret = __tree_search(root, file_offset, &prev);
149	if (!ret)
150		ret = prev;
151	if (ret)
152		tree->last = ret;
153	return ret;
154}
155
156/*
157 * Allocate and add a new ordered_extent into the per-inode tree.
158 *
159 * The tree is given a single reference on the ordered extent that was
160 * inserted.
161 */
162static int __btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
163				      u64 disk_bytenr, u64 num_bytes,
164				      u64 disk_num_bytes, int type, int dio,
165				      int compress_type)
166{
167	struct btrfs_root *root = inode->root;
168	struct btrfs_fs_info *fs_info = root->fs_info;
169	struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
170	struct rb_node *node;
171	struct btrfs_ordered_extent *entry;
172	int ret;
 
173
174	if (type == BTRFS_ORDERED_NOCOW || type == BTRFS_ORDERED_PREALLOC) {
 
175		/* For nocow write, we can release the qgroup rsv right now */
176		ret = btrfs_qgroup_free_data(inode, NULL, file_offset, num_bytes);
177		if (ret < 0)
178			return ret;
179		ret = 0;
180	} else {
181		/*
182		 * The ordered extent has reserved qgroup space, release now
183		 * and pass the reserved number for qgroup_record to free.
184		 */
185		ret = btrfs_qgroup_release_data(inode, file_offset, num_bytes);
186		if (ret < 0)
187			return ret;
188	}
189	entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
190	if (!entry)
191		return -ENOMEM;
192
193	entry->file_offset = file_offset;
194	entry->disk_bytenr = disk_bytenr;
195	entry->num_bytes = num_bytes;
 
 
196	entry->disk_num_bytes = disk_num_bytes;
 
197	entry->bytes_left = num_bytes;
198	entry->inode = igrab(&inode->vfs_inode);
199	entry->compress_type = compress_type;
200	entry->truncated_len = (u64)-1;
201	entry->qgroup_rsv = ret;
202	if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
203		set_bit(type, &entry->flags);
204
205	if (dio) {
206		percpu_counter_add_batch(&fs_info->dio_bytes, num_bytes,
207					 fs_info->delalloc_batch);
208		set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
209	}
210
211	/* one ref for the tree */
212	refcount_set(&entry->refs, 1);
213	init_waitqueue_head(&entry->wait);
214	INIT_LIST_HEAD(&entry->list);
 
215	INIT_LIST_HEAD(&entry->root_extent_list);
216	INIT_LIST_HEAD(&entry->work_list);
 
217	init_completion(&entry->completion);
218
219	trace_btrfs_ordered_extent_add(&inode->vfs_inode, entry);
 
 
 
 
 
 
 
 
 
 
220
221	spin_lock_irq(&tree->lock);
222	node = tree_insert(&tree->tree, file_offset,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
223			   &entry->rb_node);
224	if (node)
225		btrfs_panic(fs_info, -EEXIST,
226				"inconsistency in ordered tree at offset %llu",
227				file_offset);
228	spin_unlock_irq(&tree->lock);
229
230	spin_lock(&root->ordered_extent_lock);
231	list_add_tail(&entry->root_extent_list,
232		      &root->ordered_extents);
233	root->nr_ordered_extents++;
234	if (root->nr_ordered_extents == 1) {
235		spin_lock(&fs_info->ordered_root_lock);
236		BUG_ON(!list_empty(&root->ordered_root));
237		list_add_tail(&root->ordered_root, &fs_info->ordered_roots);
238		spin_unlock(&fs_info->ordered_root_lock);
239	}
240	spin_unlock(&root->ordered_extent_lock);
241
242	/*
243	 * We don't need the count_max_extents here, we can assume that all of
244	 * that work has been done at higher layers, so this is truly the
245	 * smallest the extent is going to get.
246	 */
247	spin_lock(&inode->lock);
248	btrfs_mod_outstanding_extents(inode, 1);
249	spin_unlock(&inode->lock);
250
251	return 0;
252}
253
254int btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
255			     u64 disk_bytenr, u64 num_bytes, u64 disk_num_bytes,
256			     int type)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
257{
258	return __btrfs_add_ordered_extent(inode, file_offset, disk_bytenr,
259					  num_bytes, disk_num_bytes, type, 0,
260					  BTRFS_COMPRESS_NONE);
261}
262
263int btrfs_add_ordered_extent_dio(struct btrfs_inode *inode, u64 file_offset,
264				 u64 disk_bytenr, u64 num_bytes,
265				 u64 disk_num_bytes, int type)
266{
267	return __btrfs_add_ordered_extent(inode, file_offset, disk_bytenr,
268					  num_bytes, disk_num_bytes, type, 1,
269					  BTRFS_COMPRESS_NONE);
270}
271
272int btrfs_add_ordered_extent_compress(struct btrfs_inode *inode, u64 file_offset,
273				      u64 disk_bytenr, u64 num_bytes,
274				      u64 disk_num_bytes, int type,
275				      int compress_type)
276{
277	return __btrfs_add_ordered_extent(inode, file_offset, disk_bytenr,
278					  num_bytes, disk_num_bytes, type, 0,
279					  compress_type);
280}
281
282/*
283 * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
284 * when an ordered extent is finished.  If the list covers more than one
285 * ordered extent, it is split across multiples.
286 */
287void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
288			   struct btrfs_ordered_sum *sum)
289{
290	struct btrfs_ordered_inode_tree *tree;
291
292	tree = &BTRFS_I(entry->inode)->ordered_tree;
293	spin_lock_irq(&tree->lock);
294	list_add_tail(&sum->list, &entry->list);
295	spin_unlock_irq(&tree->lock);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
296}
297
298/*
299 * this is used to account for finished IO across a given range
300 * of the file.  The IO may span ordered extents.  If
301 * a given ordered_extent is completely done, 1 is returned, otherwise
302 * 0.
303 *
304 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
305 * to make sure this function only returns 1 once for a given ordered extent.
 
 
 
 
306 *
307 * file_offset is updated to one byte past the range that is recorded as
308 * complete.  This allows you to walk forward in the file.
309 */
310int btrfs_dec_test_first_ordered_pending(struct btrfs_inode *inode,
311				   struct btrfs_ordered_extent **cached,
312				   u64 *file_offset, u64 io_size, int uptodate)
313{
314	struct btrfs_fs_info *fs_info = inode->root->fs_info;
315	struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
316	struct rb_node *node;
317	struct btrfs_ordered_extent *entry = NULL;
318	int ret;
319	unsigned long flags;
320	u64 dec_end;
321	u64 dec_start;
322	u64 to_dec;
323
324	spin_lock_irqsave(&tree->lock, flags);
325	node = tree_search(tree, *file_offset);
326	if (!node) {
327		ret = 1;
328		goto out;
329	}
 
 
 
330
331	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
332	if (!offset_in_entry(entry, *file_offset)) {
333		ret = 1;
334		goto out;
335	}
336
337	dec_start = max(*file_offset, entry->file_offset);
338	dec_end = min(*file_offset + io_size,
339		      entry->file_offset + entry->num_bytes);
340	*file_offset = dec_end;
341	if (dec_start > dec_end) {
342		btrfs_crit(fs_info, "bad ordering dec_start %llu end %llu",
343			   dec_start, dec_end);
344	}
345	to_dec = dec_end - dec_start;
346	if (to_dec > entry->bytes_left) {
347		btrfs_crit(fs_info,
348			   "bad ordered accounting left %llu size %llu",
349			   entry->bytes_left, to_dec);
350	}
351	entry->bytes_left -= to_dec;
352	if (!uptodate)
353		set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
354
355	if (entry->bytes_left == 0) {
356		ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
357		/* test_and_set_bit implies a barrier */
358		cond_wake_up_nomb(&entry->wait);
359	} else {
360		ret = 1;
361	}
362out:
363	if (!ret && cached && entry) {
364		*cached = entry;
365		refcount_inc(&entry->refs);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
366	}
367	spin_unlock_irqrestore(&tree->lock, flags);
368	return ret == 0;
369}
370
371/*
372 * this is used to account for finished IO across a given range
373 * of the file.  The IO should not span ordered extents.  If
374 * a given ordered_extent is completely done, 1 is returned, otherwise
375 * 0.
376 *
377 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
378 * to make sure this function only returns 1 once for a given ordered extent.
 
 
 
 
 
 
 
 
 
 
379 */
380int btrfs_dec_test_ordered_pending(struct inode *inode,
381				   struct btrfs_ordered_extent **cached,
382				   u64 file_offset, u64 io_size, int uptodate)
383{
384	struct btrfs_ordered_inode_tree *tree;
385	struct rb_node *node;
386	struct btrfs_ordered_extent *entry = NULL;
387	unsigned long flags;
388	int ret;
389
390	tree = &BTRFS_I(inode)->ordered_tree;
391	spin_lock_irqsave(&tree->lock, flags);
392	if (cached && *cached) {
393		entry = *cached;
394		goto have_entry;
395	}
396
397	node = tree_search(tree, file_offset);
398	if (!node) {
399		ret = 1;
400		goto out;
401	}
402
403	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
404have_entry:
405	if (!offset_in_entry(entry, file_offset)) {
406		ret = 1;
407		goto out;
408	}
409
410	if (io_size > entry->bytes_left) {
411		btrfs_crit(BTRFS_I(inode)->root->fs_info,
412			   "bad ordered accounting left %llu size %llu",
413		       entry->bytes_left, io_size);
414	}
415	entry->bytes_left -= io_size;
416	if (!uptodate)
417		set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
418
419	if (entry->bytes_left == 0) {
420		ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 
 
 
 
421		/* test_and_set_bit implies a barrier */
422		cond_wake_up_nomb(&entry->wait);
423	} else {
424		ret = 1;
425	}
426out:
427	if (!ret && cached && entry) {
428		*cached = entry;
429		refcount_inc(&entry->refs);
 
430	}
431	spin_unlock_irqrestore(&tree->lock, flags);
432	return ret == 0;
433}
434
435/*
436 * used to drop a reference on an ordered extent.  This will free
437 * the extent if the last reference is dropped
438 */
439void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
440{
441	struct list_head *cur;
442	struct btrfs_ordered_sum *sum;
443
444	trace_btrfs_ordered_extent_put(entry->inode, entry);
445
446	if (refcount_dec_and_test(&entry->refs)) {
447		ASSERT(list_empty(&entry->root_extent_list));
 
448		ASSERT(RB_EMPTY_NODE(&entry->rb_node));
449		if (entry->inode)
450			btrfs_add_delayed_iput(entry->inode);
451		while (!list_empty(&entry->list)) {
452			cur = entry->list.next;
453			sum = list_entry(cur, struct btrfs_ordered_sum, list);
454			list_del(&sum->list);
455			kvfree(sum);
456		}
457		kmem_cache_free(btrfs_ordered_extent_cache, entry);
458	}
459}
460
461/*
462 * remove an ordered extent from the tree.  No references are dropped
463 * and waiters are woken up.
464 */
465void btrfs_remove_ordered_extent(struct inode *inode,
466				 struct btrfs_ordered_extent *entry)
467{
468	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
469	struct btrfs_ordered_inode_tree *tree;
470	struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
471	struct btrfs_root *root = btrfs_inode->root;
 
472	struct rb_node *node;
 
 
 
 
 
 
 
 
473
474	/* This is paired with btrfs_add_ordered_extent. */
 
475	spin_lock(&btrfs_inode->lock);
476	btrfs_mod_outstanding_extents(btrfs_inode, -1);
477	spin_unlock(&btrfs_inode->lock);
478	if (root != fs_info->tree_root)
479		btrfs_delalloc_release_metadata(btrfs_inode, entry->num_bytes,
480						false);
481
482	if (test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
483		percpu_counter_add_batch(&fs_info->dio_bytes, -entry->num_bytes,
484					 fs_info->delalloc_batch);
 
 
 
 
485
486	tree = &btrfs_inode->ordered_tree;
487	spin_lock_irq(&tree->lock);
 
 
488	node = &entry->rb_node;
489	rb_erase(node, &tree->tree);
490	RB_CLEAR_NODE(node);
491	if (tree->last == node)
492		tree->last = NULL;
493	set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
494	spin_unlock_irq(&tree->lock);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
495
496	spin_lock(&root->ordered_extent_lock);
497	list_del_init(&entry->root_extent_list);
498	root->nr_ordered_extents--;
499
500	trace_btrfs_ordered_extent_remove(inode, entry);
501
502	if (!root->nr_ordered_extents) {
503		spin_lock(&fs_info->ordered_root_lock);
504		BUG_ON(list_empty(&root->ordered_root));
505		list_del_init(&root->ordered_root);
506		spin_unlock(&fs_info->ordered_root_lock);
507	}
508	spin_unlock(&root->ordered_extent_lock);
509	wake_up(&entry->wait);
 
 
510}
511
512static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
513{
514	struct btrfs_ordered_extent *ordered;
515
516	ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
517	btrfs_start_ordered_extent(ordered->inode, ordered, 1);
518	complete(&ordered->completion);
519}
520
521/*
522 * wait for all the ordered extents in a root.  This is done when balancing
523 * space between drives.
524 */
525u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
526			       const u64 range_start, const u64 range_len)
527{
528	struct btrfs_fs_info *fs_info = root->fs_info;
529	LIST_HEAD(splice);
530	LIST_HEAD(skipped);
531	LIST_HEAD(works);
532	struct btrfs_ordered_extent *ordered, *next;
533	u64 count = 0;
534	const u64 range_end = range_start + range_len;
535
536	mutex_lock(&root->ordered_extent_mutex);
537	spin_lock(&root->ordered_extent_lock);
538	list_splice_init(&root->ordered_extents, &splice);
539	while (!list_empty(&splice) && nr) {
540		ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
541					   root_extent_list);
542
543		if (range_end <= ordered->disk_bytenr ||
544		    ordered->disk_bytenr + ordered->disk_num_bytes <= range_start) {
545			list_move_tail(&ordered->root_extent_list, &skipped);
546			cond_resched_lock(&root->ordered_extent_lock);
547			continue;
548		}
549
550		list_move_tail(&ordered->root_extent_list,
551			       &root->ordered_extents);
552		refcount_inc(&ordered->refs);
553		spin_unlock(&root->ordered_extent_lock);
554
555		btrfs_init_work(&ordered->flush_work,
556				btrfs_run_ordered_extent_work, NULL, NULL);
557		list_add_tail(&ordered->work_list, &works);
558		btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work);
559
560		cond_resched();
561		spin_lock(&root->ordered_extent_lock);
562		if (nr != U64_MAX)
563			nr--;
564		count++;
565	}
566	list_splice_tail(&skipped, &root->ordered_extents);
567	list_splice_tail(&splice, &root->ordered_extents);
568	spin_unlock(&root->ordered_extent_lock);
569
570	list_for_each_entry_safe(ordered, next, &works, work_list) {
571		list_del_init(&ordered->work_list);
572		wait_for_completion(&ordered->completion);
573		btrfs_put_ordered_extent(ordered);
574		cond_resched();
575	}
576	mutex_unlock(&root->ordered_extent_mutex);
577
578	return count;
579}
580
581void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
582			     const u64 range_start, const u64 range_len)
583{
584	struct btrfs_root *root;
585	struct list_head splice;
586	u64 done;
587
588	INIT_LIST_HEAD(&splice);
589
590	mutex_lock(&fs_info->ordered_operations_mutex);
591	spin_lock(&fs_info->ordered_root_lock);
592	list_splice_init(&fs_info->ordered_roots, &splice);
593	while (!list_empty(&splice) && nr) {
594		root = list_first_entry(&splice, struct btrfs_root,
595					ordered_root);
596		root = btrfs_grab_root(root);
597		BUG_ON(!root);
598		list_move_tail(&root->ordered_root,
599			       &fs_info->ordered_roots);
600		spin_unlock(&fs_info->ordered_root_lock);
601
602		done = btrfs_wait_ordered_extents(root, nr,
603						  range_start, range_len);
604		btrfs_put_root(root);
605
606		spin_lock(&fs_info->ordered_root_lock);
607		if (nr != U64_MAX) {
608			nr -= done;
609		}
610	}
611	list_splice_tail(&splice, &fs_info->ordered_roots);
612	spin_unlock(&fs_info->ordered_root_lock);
613	mutex_unlock(&fs_info->ordered_operations_mutex);
614}
615
616/*
617 * Used to start IO or wait for a given ordered extent to finish.
618 *
619 * If wait is one, this effectively waits on page writeback for all the pages
620 * in the extent, and it waits on the io completion code to insert
621 * metadata into the btree corresponding to the extent
622 */
623void btrfs_start_ordered_extent(struct inode *inode,
624				       struct btrfs_ordered_extent *entry,
625				       int wait)
626{
627	u64 start = entry->file_offset;
628	u64 end = start + entry->num_bytes - 1;
 
 
629
630	trace_btrfs_ordered_extent_start(inode, entry);
631
632	/*
 
 
 
 
 
 
633	 * pages in the range can be dirty, clean or writeback.  We
634	 * start IO on any dirty ones so the wait doesn't stall waiting
635	 * for the flusher thread to find them
636	 */
637	if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
638		filemap_fdatawrite_range(inode->i_mapping, start, end);
639	if (wait) {
640		wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
641						 &entry->flags));
642	}
643}
644
645/*
646 * Used to wait on ordered extents across a large range of bytes.
647 */
648int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
649{
650	int ret = 0;
651	int ret_wb = 0;
652	u64 end;
653	u64 orig_end;
654	struct btrfs_ordered_extent *ordered;
655
656	if (start + len < start) {
657		orig_end = INT_LIMIT(loff_t);
658	} else {
659		orig_end = start + len - 1;
660		if (orig_end > INT_LIMIT(loff_t))
661			orig_end = INT_LIMIT(loff_t);
662	}
663
664	/* start IO across the range first to instantiate any delalloc
665	 * extents
666	 */
667	ret = btrfs_fdatawrite_range(inode, start, orig_end);
668	if (ret)
669		return ret;
670
671	/*
672	 * If we have a writeback error don't return immediately. Wait first
673	 * for any ordered extents that haven't completed yet. This is to make
674	 * sure no one can dirty the same page ranges and call writepages()
675	 * before the ordered extents complete - to avoid failures (-EEXIST)
676	 * when adding the new ordered extents to the ordered tree.
677	 */
678	ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
679
680	end = orig_end;
681	while (1) {
682		ordered = btrfs_lookup_first_ordered_extent(inode, end);
683		if (!ordered)
684			break;
685		if (ordered->file_offset > orig_end) {
686			btrfs_put_ordered_extent(ordered);
687			break;
688		}
689		if (ordered->file_offset + ordered->num_bytes <= start) {
690			btrfs_put_ordered_extent(ordered);
691			break;
692		}
693		btrfs_start_ordered_extent(inode, ordered, 1);
694		end = ordered->file_offset;
695		/*
696		 * If the ordered extent had an error save the error but don't
697		 * exit without waiting first for all other ordered extents in
698		 * the range to complete.
699		 */
700		if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
701			ret = -EIO;
702		btrfs_put_ordered_extent(ordered);
703		if (end == 0 || end == start)
704			break;
705		end--;
706	}
707	return ret_wb ? ret_wb : ret;
708}
709
710/*
711 * find an ordered extent corresponding to file_offset.  return NULL if
712 * nothing is found, otherwise take a reference on the extent and return it
713 */
714struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct btrfs_inode *inode,
715							 u64 file_offset)
716{
717	struct btrfs_ordered_inode_tree *tree;
718	struct rb_node *node;
719	struct btrfs_ordered_extent *entry = NULL;
 
720
721	tree = &inode->ordered_tree;
722	spin_lock_irq(&tree->lock);
723	node = tree_search(tree, file_offset);
724	if (!node)
725		goto out;
726
727	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
728	if (!offset_in_entry(entry, file_offset))
729		entry = NULL;
730	if (entry)
731		refcount_inc(&entry->refs);
 
 
732out:
733	spin_unlock_irq(&tree->lock);
734	return entry;
735}
736
737/* Since the DIO code tries to lock a wide area we need to look for any ordered
738 * extents that exist in the range, rather than just the start of the range.
739 */
740struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
741		struct btrfs_inode *inode, u64 file_offset, u64 len)
742{
743	struct btrfs_ordered_inode_tree *tree;
744	struct rb_node *node;
745	struct btrfs_ordered_extent *entry = NULL;
746
747	tree = &inode->ordered_tree;
748	spin_lock_irq(&tree->lock);
749	node = tree_search(tree, file_offset);
750	if (!node) {
751		node = tree_search(tree, file_offset + len);
752		if (!node)
753			goto out;
754	}
755
756	while (1) {
757		entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
758		if (range_overlaps(entry, file_offset, len))
759			break;
760
761		if (entry->file_offset >= file_offset + len) {
762			entry = NULL;
763			break;
764		}
765		entry = NULL;
766		node = rb_next(node);
767		if (!node)
768			break;
769	}
770out:
771	if (entry)
772		refcount_inc(&entry->refs);
773	spin_unlock_irq(&tree->lock);
 
 
774	return entry;
775}
776
777/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
778 * lookup and return any extent before 'file_offset'.  NULL is returned
779 * if none is found
780 */
781struct btrfs_ordered_extent *
782btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset)
783{
784	struct btrfs_ordered_inode_tree *tree;
785	struct rb_node *node;
786	struct btrfs_ordered_extent *entry = NULL;
787
788	tree = &BTRFS_I(inode)->ordered_tree;
789	spin_lock_irq(&tree->lock);
790	node = tree_search(tree, file_offset);
791	if (!node)
792		goto out;
793
794	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
795	refcount_inc(&entry->refs);
 
796out:
797	spin_unlock_irq(&tree->lock);
798	return entry;
799}
800
801/*
802 * search the ordered extents for one corresponding to 'offset' and
803 * try to find a checksum.  This is used because we allow pages to
804 * be reclaimed before their checksum is actually put into the btree
 
 
 
 
805 */
806int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
807			   u8 *sum, int len)
808{
809	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
810	struct btrfs_ordered_sum *ordered_sum;
811	struct btrfs_ordered_extent *ordered;
812	struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
813	unsigned long num_sectors;
814	unsigned long i;
815	u32 sectorsize = btrfs_inode_sectorsize(inode);
816	const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
817	int index = 0;
818
819	ordered = btrfs_lookup_ordered_extent(BTRFS_I(inode), offset);
820	if (!ordered)
821		return 0;
 
 
 
 
 
 
 
822
823	spin_lock_irq(&tree->lock);
824	list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
825		if (disk_bytenr >= ordered_sum->bytenr &&
826		    disk_bytenr < ordered_sum->bytenr + ordered_sum->len) {
827			i = (disk_bytenr - ordered_sum->bytenr) >>
828			    inode->i_sb->s_blocksize_bits;
829			num_sectors = ordered_sum->len >>
830				      inode->i_sb->s_blocksize_bits;
831			num_sectors = min_t(int, len - index, num_sectors - i);
832			memcpy(sum + index, ordered_sum->sums + i * csum_size,
833			       num_sectors * csum_size);
834
835			index += (int)num_sectors * csum_size;
836			if (index == len)
837				goto out;
838			disk_bytenr += num_sectors * sectorsize;
839		}
840	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
841out:
842	spin_unlock_irq(&tree->lock);
843	btrfs_put_ordered_extent(ordered);
844	return index;
 
 
 
 
845}
846
847/*
848 * btrfs_flush_ordered_range - Lock the passed range and ensures all pending
849 * ordered extents in it are run to completion.
850 *
851 * @inode:        Inode whose ordered tree is to be searched
852 * @start:        Beginning of range to flush
853 * @end:          Last byte of range to lock
854 * @cached_state: If passed, will return the extent state responsible for the
855 * locked range. It's the caller's responsibility to free the cached state.
 
856 *
857 * This function always returns with the given range locked, ensuring after it's
858 * called no order extent can be pending.
859 */
860void btrfs_lock_and_flush_ordered_range(struct btrfs_inode *inode, u64 start,
861					u64 end,
862					struct extent_state **cached_state)
863{
864	struct btrfs_ordered_extent *ordered;
865	struct extent_state *cache = NULL;
866	struct extent_state **cachedp = &cache;
867
868	if (cached_state)
869		cachedp = cached_state;
870
871	while (1) {
872		lock_extent_bits(&inode->io_tree, start, end, cachedp);
873		ordered = btrfs_lookup_ordered_range(inode, start,
874						     end - start + 1);
875		if (!ordered) {
876			/*
877			 * If no external cached_state has been passed then
878			 * decrement the extra ref taken for cachedp since we
879			 * aren't exposing it outside of this function
880			 */
881			if (!cached_state)
882				refcount_dec(&cache->refs);
883			break;
884		}
885		unlock_extent_cached(&inode->io_tree, start, end, cachedp);
886		btrfs_start_ordered_extent(&inode->vfs_inode, ordered, 1);
887		btrfs_put_ordered_extent(ordered);
888	}
889}
890
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
891int __init ordered_data_init(void)
892{
893	btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
894				     sizeof(struct btrfs_ordered_extent), 0,
895				     SLAB_MEM_SPREAD,
896				     NULL);
897	if (!btrfs_ordered_extent_cache)
898		return -ENOMEM;
899
900	return 0;
901}
902
903void __cold ordered_data_exit(void)
904{
905	kmem_cache_destroy(btrfs_ordered_extent_cache);
906}