Linux Audio

Check our new training course

Loading...
v3.1
 
  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}
v4.17
   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
  17static struct kmem_cache *btrfs_ordered_extent_cache;
  18
  19static 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 */
  29static 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
  53static 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 */
  65static 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 */
 118static 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
 126static 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 */
 139static 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 */
 172static 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
 244int 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
 252int 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
 260int 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 */
 274void 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 */
 298int 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		/*
 347		 * Implicit memory barrier after test_and_set_bit
 348		 */
 349		if (waitqueue_active(&entry->wait))
 350			wake_up(&entry->wait);
 351	} else {
 352		ret = 1;
 353	}
 354out:
 355	if (!ret && cached && entry) {
 356		*cached = entry;
 357		refcount_inc(&entry->refs);
 358	}
 359	spin_unlock_irqrestore(&tree->lock, flags);
 360	return ret == 0;
 361}
 362
 363/*
 364 * this is used to account for finished IO across a given range
 365 * of the file.  The IO should not span ordered extents.  If
 366 * a given ordered_extent is completely done, 1 is returned, otherwise
 367 * 0.
 368 *
 369 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
 370 * to make sure this function only returns 1 once for a given ordered extent.
 371 */
 372int btrfs_dec_test_ordered_pending(struct inode *inode,
 373				   struct btrfs_ordered_extent **cached,
 374				   u64 file_offset, u64 io_size, int uptodate)
 375{
 376	struct btrfs_ordered_inode_tree *tree;
 377	struct rb_node *node;
 378	struct btrfs_ordered_extent *entry = NULL;
 379	unsigned long flags;
 380	int ret;
 381
 382	tree = &BTRFS_I(inode)->ordered_tree;
 383	spin_lock_irqsave(&tree->lock, flags);
 384	if (cached && *cached) {
 385		entry = *cached;
 386		goto have_entry;
 387	}
 388
 389	node = tree_search(tree, file_offset);
 390	if (!node) {
 391		ret = 1;
 392		goto out;
 393	}
 394
 395	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 396have_entry:
 397	if (!offset_in_entry(entry, file_offset)) {
 398		ret = 1;
 399		goto out;
 400	}
 401
 402	if (io_size > entry->bytes_left) {
 403		btrfs_crit(BTRFS_I(inode)->root->fs_info,
 404			   "bad ordered accounting left %llu size %llu",
 405		       entry->bytes_left, io_size);
 406	}
 407	entry->bytes_left -= io_size;
 408	if (!uptodate)
 409		set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
 410
 411	if (entry->bytes_left == 0) {
 412		ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 413		/*
 414		 * Implicit memory barrier after test_and_set_bit
 415		 */
 416		if (waitqueue_active(&entry->wait))
 417			wake_up(&entry->wait);
 418	} else {
 419		ret = 1;
 420	}
 421out:
 422	if (!ret && cached && entry) {
 423		*cached = entry;
 424		refcount_inc(&entry->refs);
 425	}
 426	spin_unlock_irqrestore(&tree->lock, flags);
 427	return ret == 0;
 428}
 429
 430/* Needs to either be called under a log transaction or the log_mutex */
 431void btrfs_get_logged_extents(struct btrfs_inode *inode,
 432			      struct list_head *logged_list,
 433			      const loff_t start,
 434			      const loff_t end)
 435{
 436	struct btrfs_ordered_inode_tree *tree;
 437	struct btrfs_ordered_extent *ordered;
 438	struct rb_node *n;
 439	struct rb_node *prev;
 440
 441	tree = &inode->ordered_tree;
 442	spin_lock_irq(&tree->lock);
 443	n = __tree_search(&tree->tree, end, &prev);
 444	if (!n)
 445		n = prev;
 446	for (; n; n = rb_prev(n)) {
 447		ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
 448		if (ordered->file_offset > end)
 449			continue;
 450		if (entry_end(ordered) <= start)
 451			break;
 452		if (test_and_set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
 453			continue;
 454		list_add(&ordered->log_list, logged_list);
 455		refcount_inc(&ordered->refs);
 456	}
 457	spin_unlock_irq(&tree->lock);
 458}
 459
 460void btrfs_put_logged_extents(struct list_head *logged_list)
 461{
 462	struct btrfs_ordered_extent *ordered;
 463
 464	while (!list_empty(logged_list)) {
 465		ordered = list_first_entry(logged_list,
 466					   struct btrfs_ordered_extent,
 467					   log_list);
 468		list_del_init(&ordered->log_list);
 469		btrfs_put_ordered_extent(ordered);
 470	}
 471}
 472
 473void btrfs_submit_logged_extents(struct list_head *logged_list,
 474				 struct btrfs_root *log)
 475{
 476	int index = log->log_transid % 2;
 477
 478	spin_lock_irq(&log->log_extents_lock[index]);
 479	list_splice_tail(logged_list, &log->logged_list[index]);
 480	spin_unlock_irq(&log->log_extents_lock[index]);
 481}
 482
 483void btrfs_wait_logged_extents(struct btrfs_trans_handle *trans,
 484			       struct btrfs_root *log, u64 transid)
 485{
 486	struct btrfs_ordered_extent *ordered;
 487	int index = transid % 2;
 488
 489	spin_lock_irq(&log->log_extents_lock[index]);
 490	while (!list_empty(&log->logged_list[index])) {
 491		struct inode *inode;
 492		ordered = list_first_entry(&log->logged_list[index],
 493					   struct btrfs_ordered_extent,
 494					   log_list);
 495		list_del_init(&ordered->log_list);
 496		inode = ordered->inode;
 497		spin_unlock_irq(&log->log_extents_lock[index]);
 498
 499		if (!test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags) &&
 500		    !test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) {
 501			u64 start = ordered->file_offset;
 502			u64 end = ordered->file_offset + ordered->len - 1;
 503
 504			WARN_ON(!inode);
 505			filemap_fdatawrite_range(inode->i_mapping, start, end);
 506		}
 507		wait_event(ordered->wait, test_bit(BTRFS_ORDERED_IO_DONE,
 508						   &ordered->flags));
 509
 510		/*
 511		 * In order to keep us from losing our ordered extent
 512		 * information when committing the transaction we have to make
 513		 * sure that any logged extents are completed when we go to
 514		 * commit the transaction.  To do this we simply increase the
 515		 * current transactions pending_ordered counter and decrement it
 516		 * when the ordered extent completes.
 517		 */
 518		if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
 519			struct btrfs_ordered_inode_tree *tree;
 520
 521			tree = &BTRFS_I(inode)->ordered_tree;
 522			spin_lock_irq(&tree->lock);
 523			if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
 524				set_bit(BTRFS_ORDERED_PENDING, &ordered->flags);
 525				atomic_inc(&trans->transaction->pending_ordered);
 526			}
 527			spin_unlock_irq(&tree->lock);
 528		}
 529		btrfs_put_ordered_extent(ordered);
 530		spin_lock_irq(&log->log_extents_lock[index]);
 531	}
 532	spin_unlock_irq(&log->log_extents_lock[index]);
 533}
 534
 535void btrfs_free_logged_extents(struct btrfs_root *log, u64 transid)
 536{
 537	struct btrfs_ordered_extent *ordered;
 538	int index = transid % 2;
 539
 540	spin_lock_irq(&log->log_extents_lock[index]);
 541	while (!list_empty(&log->logged_list[index])) {
 542		ordered = list_first_entry(&log->logged_list[index],
 543					   struct btrfs_ordered_extent,
 544					   log_list);
 545		list_del_init(&ordered->log_list);
 546		spin_unlock_irq(&log->log_extents_lock[index]);
 547		btrfs_put_ordered_extent(ordered);
 548		spin_lock_irq(&log->log_extents_lock[index]);
 549	}
 550	spin_unlock_irq(&log->log_extents_lock[index]);
 551}
 552
 553/*
 554 * used to drop a reference on an ordered extent.  This will free
 555 * the extent if the last reference is dropped
 556 */
 557void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
 558{
 559	struct list_head *cur;
 560	struct btrfs_ordered_sum *sum;
 561
 562	trace_btrfs_ordered_extent_put(entry->inode, entry);
 563
 564	if (refcount_dec_and_test(&entry->refs)) {
 565		ASSERT(list_empty(&entry->log_list));
 566		ASSERT(list_empty(&entry->trans_list));
 567		ASSERT(list_empty(&entry->root_extent_list));
 568		ASSERT(RB_EMPTY_NODE(&entry->rb_node));
 569		if (entry->inode)
 570			btrfs_add_delayed_iput(entry->inode);
 571		while (!list_empty(&entry->list)) {
 572			cur = entry->list.next;
 573			sum = list_entry(cur, struct btrfs_ordered_sum, list);
 574			list_del(&sum->list);
 575			kfree(sum);
 576		}
 577		kmem_cache_free(btrfs_ordered_extent_cache, entry);
 578	}
 
 579}
 580
 581/*
 582 * remove an ordered extent from the tree.  No references are dropped
 583 * and waiters are woken up.
 
 584 */
 585void btrfs_remove_ordered_extent(struct inode *inode,
 586				 struct btrfs_ordered_extent *entry)
 587{
 588	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 589	struct btrfs_ordered_inode_tree *tree;
 590	struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
 591	struct btrfs_root *root = btrfs_inode->root;
 592	struct rb_node *node;
 593	bool dec_pending_ordered = false;
 594
 595	/* This is paired with btrfs_add_ordered_extent. */
 596	spin_lock(&btrfs_inode->lock);
 597	btrfs_mod_outstanding_extents(btrfs_inode, -1);
 598	spin_unlock(&btrfs_inode->lock);
 599	if (root != fs_info->tree_root)
 600		btrfs_delalloc_release_metadata(btrfs_inode, entry->len, false);
 601
 602	tree = &btrfs_inode->ordered_tree;
 603	spin_lock_irq(&tree->lock);
 604	node = &entry->rb_node;
 605	rb_erase(node, &tree->tree);
 606	RB_CLEAR_NODE(node);
 607	if (tree->last == node)
 608		tree->last = NULL;
 609	set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
 610	if (test_and_clear_bit(BTRFS_ORDERED_PENDING, &entry->flags))
 611		dec_pending_ordered = true;
 612	spin_unlock_irq(&tree->lock);
 613
 614	/*
 615	 * The current running transaction is waiting on us, we need to let it
 616	 * know that we're complete and wake it up.
 617	 */
 618	if (dec_pending_ordered) {
 619		struct btrfs_transaction *trans;
 620
 621		/*
 622		 * The checks for trans are just a formality, it should be set,
 623		 * but if it isn't we don't want to deref/assert under the spin
 624		 * lock, so be nice and check if trans is set, but ASSERT() so
 625		 * if it isn't set a developer will notice.
 626		 */
 627		spin_lock(&fs_info->trans_lock);
 628		trans = fs_info->running_transaction;
 629		if (trans)
 630			refcount_inc(&trans->use_count);
 631		spin_unlock(&fs_info->trans_lock);
 632
 633		ASSERT(trans);
 634		if (trans) {
 635			if (atomic_dec_and_test(&trans->pending_ordered))
 636				wake_up(&trans->pending_wait);
 637			btrfs_put_transaction(trans);
 638		}
 639	}
 640
 641	spin_lock(&root->ordered_extent_lock);
 642	list_del_init(&entry->root_extent_list);
 643	root->nr_ordered_extents--;
 644
 645	trace_btrfs_ordered_extent_remove(inode, entry);
 646
 647	if (!root->nr_ordered_extents) {
 648		spin_lock(&fs_info->ordered_root_lock);
 649		BUG_ON(list_empty(&root->ordered_root));
 650		list_del_init(&root->ordered_root);
 651		spin_unlock(&fs_info->ordered_root_lock);
 
 
 
 652	}
 653	spin_unlock(&root->ordered_extent_lock);
 654	wake_up(&entry->wait);
 
 655}
 656
 657static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
 
 
 
 
 
 658{
 659	struct btrfs_ordered_extent *ordered;
 
 
 
 
 
 
 
 660
 661	ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
 662	btrfs_start_ordered_extent(ordered->inode, ordered, 1);
 663	complete(&ordered->completion);
 664}
 665
 666/*
 667 * wait for all the ordered extents in a root.  This is done when balancing
 668 * space between drives.
 669 */
 670u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
 671			       const u64 range_start, const u64 range_len)
 672{
 673	struct btrfs_fs_info *fs_info = root->fs_info;
 674	LIST_HEAD(splice);
 675	LIST_HEAD(skipped);
 676	LIST_HEAD(works);
 677	struct btrfs_ordered_extent *ordered, *next;
 678	u64 count = 0;
 679	const u64 range_end = range_start + range_len;
 680
 681	mutex_lock(&root->ordered_extent_mutex);
 682	spin_lock(&root->ordered_extent_lock);
 683	list_splice_init(&root->ordered_extents, &splice);
 684	while (!list_empty(&splice) && nr) {
 685		ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
 686					   root_extent_list);
 687
 688		if (range_end <= ordered->start ||
 689		    ordered->start + ordered->disk_len <= range_start) {
 690			list_move_tail(&ordered->root_extent_list, &skipped);
 691			cond_resched_lock(&root->ordered_extent_lock);
 692			continue;
 693		}
 694
 695		list_move_tail(&ordered->root_extent_list,
 696			       &root->ordered_extents);
 697		refcount_inc(&ordered->refs);
 698		spin_unlock(&root->ordered_extent_lock);
 699
 700		btrfs_init_work(&ordered->flush_work,
 701				btrfs_flush_delalloc_helper,
 702				btrfs_run_ordered_extent_work, NULL, NULL);
 703		list_add_tail(&ordered->work_list, &works);
 704		btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work);
 
 
 
 
 
 
 
 
 
 
 705
 706		cond_resched();
 707		spin_lock(&root->ordered_extent_lock);
 708		if (nr != U64_MAX)
 709			nr--;
 710		count++;
 711	}
 712	list_splice_tail(&skipped, &root->ordered_extents);
 713	list_splice_tail(&splice, &root->ordered_extents);
 714	spin_unlock(&root->ordered_extent_lock);
 715
 716	list_for_each_entry_safe(ordered, next, &works, work_list) {
 717		list_del_init(&ordered->work_list);
 718		wait_for_completion(&ordered->completion);
 719		btrfs_put_ordered_extent(ordered);
 720		cond_resched();
 721	}
 722	mutex_unlock(&root->ordered_extent_mutex);
 723
 724	return count;
 725}
 726
 727u64 btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
 728			     const u64 range_start, const u64 range_len)
 
 
 
 
 
 
 
 
 
 729{
 730	struct btrfs_root *root;
 
 731	struct list_head splice;
 732	u64 total_done = 0;
 733	u64 done;
 734
 735	INIT_LIST_HEAD(&splice);
 736
 737	mutex_lock(&fs_info->ordered_operations_mutex);
 738	spin_lock(&fs_info->ordered_root_lock);
 739	list_splice_init(&fs_info->ordered_roots, &splice);
 740	while (!list_empty(&splice) && nr) {
 741		root = list_first_entry(&splice, struct btrfs_root,
 742					ordered_root);
 743		root = btrfs_grab_fs_root(root);
 744		BUG_ON(!root);
 745		list_move_tail(&root->ordered_root,
 746			       &fs_info->ordered_roots);
 747		spin_unlock(&fs_info->ordered_root_lock);
 748
 749		done = btrfs_wait_ordered_extents(root, nr,
 750						  range_start, range_len);
 751		btrfs_put_fs_root(root);
 752		total_done += done;
 753
 754		spin_lock(&fs_info->ordered_root_lock);
 755		if (nr != U64_MAX) {
 756			nr -= done;
 
 
 
 
 
 
 
 
 
 
 757		}
 
 
 
 758	}
 759	list_splice_tail(&splice, &fs_info->ordered_roots);
 760	spin_unlock(&fs_info->ordered_root_lock);
 761	mutex_unlock(&fs_info->ordered_operations_mutex);
 
 
 762
 763	return total_done;
 764}
 765
 766/*
 767 * Used to start IO or wait for a given ordered extent to finish.
 768 *
 769 * If wait is one, this effectively waits on page writeback for all the pages
 770 * in the extent, and it waits on the io completion code to insert
 771 * metadata into the btree corresponding to the extent
 772 */
 773void btrfs_start_ordered_extent(struct inode *inode,
 774				       struct btrfs_ordered_extent *entry,
 775				       int wait)
 776{
 777	u64 start = entry->file_offset;
 778	u64 end = start + entry->len - 1;
 779
 780	trace_btrfs_ordered_extent_start(inode, entry);
 781
 782	/*
 783	 * pages in the range can be dirty, clean or writeback.  We
 784	 * start IO on any dirty ones so the wait doesn't stall waiting
 785	 * for the flusher thread to find them
 786	 */
 787	if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
 788		filemap_fdatawrite_range(inode->i_mapping, start, end);
 789	if (wait) {
 790		wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
 791						 &entry->flags));
 792	}
 793}
 794
 795/*
 796 * Used to wait on ordered extents across a large range of bytes.
 797 */
 798int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
 799{
 800	int ret = 0;
 801	int ret_wb = 0;
 802	u64 end;
 803	u64 orig_end;
 804	struct btrfs_ordered_extent *ordered;
 
 805
 806	if (start + len < start) {
 807		orig_end = INT_LIMIT(loff_t);
 808	} else {
 809		orig_end = start + len - 1;
 810		if (orig_end > INT_LIMIT(loff_t))
 811			orig_end = INT_LIMIT(loff_t);
 812	}
 813
 814	/* start IO across the range first to instantiate any delalloc
 815	 * extents
 816	 */
 817	ret = btrfs_fdatawrite_range(inode, start, orig_end);
 818	if (ret)
 819		return ret;
 820
 821	/*
 822	 * If we have a writeback error don't return immediately. Wait first
 823	 * for any ordered extents that haven't completed yet. This is to make
 824	 * sure no one can dirty the same page ranges and call writepages()
 825	 * before the ordered extents complete - to avoid failures (-EEXIST)
 826	 * when adding the new ordered extents to the ordered tree.
 827	 */
 828	ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
 
 
 829
 830	end = orig_end;
 
 831	while (1) {
 832		ordered = btrfs_lookup_first_ordered_extent(inode, end);
 833		if (!ordered)
 834			break;
 835		if (ordered->file_offset > orig_end) {
 836			btrfs_put_ordered_extent(ordered);
 837			break;
 838		}
 839		if (ordered->file_offset + ordered->len <= start) {
 840			btrfs_put_ordered_extent(ordered);
 841			break;
 842		}
 
 843		btrfs_start_ordered_extent(inode, ordered, 1);
 844		end = ordered->file_offset;
 845		if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
 846			ret = -EIO;
 847		btrfs_put_ordered_extent(ordered);
 848		if (ret || end == 0 || end == start)
 849			break;
 850		end--;
 851	}
 852	return ret_wb ? ret_wb : ret;
 
 
 
 
 
 853}
 854
 855/*
 856 * find an ordered extent corresponding to file_offset.  return NULL if
 857 * nothing is found, otherwise take a reference on the extent and return it
 858 */
 859struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
 860							 u64 file_offset)
 861{
 862	struct btrfs_ordered_inode_tree *tree;
 863	struct rb_node *node;
 864	struct btrfs_ordered_extent *entry = NULL;
 865
 866	tree = &BTRFS_I(inode)->ordered_tree;
 867	spin_lock_irq(&tree->lock);
 868	node = tree_search(tree, file_offset);
 869	if (!node)
 870		goto out;
 871
 872	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 873	if (!offset_in_entry(entry, file_offset))
 874		entry = NULL;
 875	if (entry)
 876		refcount_inc(&entry->refs);
 877out:
 878	spin_unlock_irq(&tree->lock);
 879	return entry;
 880}
 881
 882/* Since the DIO code tries to lock a wide area we need to look for any ordered
 883 * extents that exist in the range, rather than just the start of the range.
 884 */
 885struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
 886		struct btrfs_inode *inode, u64 file_offset, u64 len)
 
 887{
 888	struct btrfs_ordered_inode_tree *tree;
 889	struct rb_node *node;
 890	struct btrfs_ordered_extent *entry = NULL;
 891
 892	tree = &inode->ordered_tree;
 893	spin_lock_irq(&tree->lock);
 894	node = tree_search(tree, file_offset);
 895	if (!node) {
 896		node = tree_search(tree, file_offset + len);
 897		if (!node)
 898			goto out;
 899	}
 900
 901	while (1) {
 902		entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 903		if (range_overlaps(entry, file_offset, len))
 904			break;
 905
 906		if (entry->file_offset >= file_offset + len) {
 907			entry = NULL;
 908			break;
 909		}
 910		entry = NULL;
 911		node = rb_next(node);
 912		if (!node)
 913			break;
 914	}
 915out:
 916	if (entry)
 917		refcount_inc(&entry->refs);
 918	spin_unlock_irq(&tree->lock);
 919	return entry;
 920}
 921
 922bool btrfs_have_ordered_extents_in_range(struct inode *inode,
 923					 u64 file_offset,
 924					 u64 len)
 925{
 926	struct btrfs_ordered_extent *oe;
 927
 928	oe = btrfs_lookup_ordered_range(BTRFS_I(inode), file_offset, len);
 929	if (oe) {
 930		btrfs_put_ordered_extent(oe);
 931		return true;
 932	}
 933	return false;
 934}
 935
 936/*
 937 * lookup and return any extent before 'file_offset'.  NULL is returned
 938 * if none is found
 939 */
 940struct btrfs_ordered_extent *
 941btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset)
 942{
 943	struct btrfs_ordered_inode_tree *tree;
 944	struct rb_node *node;
 945	struct btrfs_ordered_extent *entry = NULL;
 946
 947	tree = &BTRFS_I(inode)->ordered_tree;
 948	spin_lock_irq(&tree->lock);
 949	node = tree_search(tree, file_offset);
 950	if (!node)
 951		goto out;
 952
 953	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 954	refcount_inc(&entry->refs);
 955out:
 956	spin_unlock_irq(&tree->lock);
 957	return entry;
 958}
 959
 960/*
 961 * After an extent is done, call this to conditionally update the on disk
 962 * i_size.  i_size is updated to cover any fully written part of the file.
 963 */
 964int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
 965				struct btrfs_ordered_extent *ordered)
 966{
 967	struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
 
 968	u64 disk_i_size;
 969	u64 new_i_size;
 
 970	u64 i_size = i_size_read(inode);
 971	struct rb_node *node;
 972	struct rb_node *prev = NULL;
 973	struct btrfs_ordered_extent *test;
 974	int ret = 1;
 975	u64 orig_offset = offset;
 976
 977	spin_lock_irq(&tree->lock);
 978	if (ordered) {
 979		offset = entry_end(ordered);
 980		if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags))
 981			offset = min(offset,
 982				     ordered->file_offset +
 983				     ordered->truncated_len);
 984	} else {
 985		offset = ALIGN(offset, btrfs_inode_sectorsize(inode));
 986	}
 987	disk_i_size = BTRFS_I(inode)->disk_i_size;
 988
 989	/*
 990	 * truncate file.
 991	 * If ordered is not NULL, then this is called from endio and
 992	 * disk_i_size will be updated by either truncate itself or any
 993	 * in-flight IOs which are inside the disk_i_size.
 994	 *
 995	 * Because btrfs_setsize() may set i_size with disk_i_size if truncate
 996	 * fails somehow, we need to make sure we have a precise disk_i_size by
 997	 * updating it as usual.
 998	 *
 999	 */
1000	if (!ordered && disk_i_size > i_size) {
1001		BTRFS_I(inode)->disk_i_size = orig_offset;
1002		ret = 0;
1003		goto out;
1004	}
1005
1006	/*
1007	 * if the disk i_size is already at the inode->i_size, or
1008	 * this ordered extent is inside the disk i_size, we're done
1009	 */
1010	if (disk_i_size == i_size)
1011		goto out;
 
1012
1013	/*
1014	 * We still need to update disk_i_size if outstanding_isize is greater
1015	 * than disk_i_size.
1016	 */
1017	if (offset <= disk_i_size &&
1018	    (!ordered || ordered->outstanding_isize <= disk_i_size))
1019		goto out;
1020
1021	/*
1022	 * walk backward from this ordered extent to disk_i_size.
1023	 * if we find an ordered extent then we can't update disk i_size
1024	 * yet
1025	 */
1026	if (ordered) {
1027		node = rb_prev(&ordered->rb_node);
1028	} else {
1029		prev = tree_search(tree, offset);
1030		/*
1031		 * we insert file extents without involving ordered struct,
1032		 * so there should be no ordered struct cover this offset
1033		 */
1034		if (prev) {
1035			test = rb_entry(prev, struct btrfs_ordered_extent,
1036					rb_node);
1037			BUG_ON(offset_in_entry(test, offset));
1038		}
1039		node = prev;
1040	}
1041	for (; node; node = rb_prev(node)) {
1042		test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
1043
1044		/* We treat this entry as if it doesn't exist */
1045		if (test_bit(BTRFS_ORDERED_UPDATED_ISIZE, &test->flags))
1046			continue;
1047
1048		if (entry_end(test) <= disk_i_size)
1049			break;
1050		if (test->file_offset >= i_size)
1051			break;
 
 
 
 
 
1052
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1053		/*
1054		 * We don't update disk_i_size now, so record this undealt
1055		 * i_size. Or we will not know the real i_size.
1056		 */
1057		if (test->outstanding_isize < offset)
1058			test->outstanding_isize = offset;
1059		if (ordered &&
1060		    ordered->outstanding_isize > test->outstanding_isize)
1061			test->outstanding_isize = ordered->outstanding_isize;
1062		goto out;
1063	}
1064	new_i_size = min_t(u64, offset, i_size);
1065
1066	/*
1067	 * Some ordered extents may completed before the current one, and
1068	 * we hold the real i_size in ->outstanding_isize.
1069	 */
1070	if (ordered && ordered->outstanding_isize > new_i_size)
1071		new_i_size = min_t(u64, ordered->outstanding_isize, i_size);
 
 
 
 
 
1072	BTRFS_I(inode)->disk_i_size = new_i_size;
1073	ret = 0;
1074out:
1075	/*
1076	 * We need to do this because we can't remove ordered extents until
1077	 * after the i_disk_size has been updated and then the inode has been
1078	 * updated to reflect the change, so we need to tell anybody who finds
1079	 * this ordered extent that we've already done all the real work, we
1080	 * just haven't completed all the other work.
1081	 */
1082	if (ordered)
1083		set_bit(BTRFS_ORDERED_UPDATED_ISIZE, &ordered->flags);
1084	spin_unlock_irq(&tree->lock);
 
 
1085	return ret;
1086}
1087
1088/*
1089 * search the ordered extents for one corresponding to 'offset' and
1090 * try to find a checksum.  This is used because we allow pages to
1091 * be reclaimed before their checksum is actually put into the btree
1092 */
1093int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
1094			   u32 *sum, int len)
1095{
1096	struct btrfs_ordered_sum *ordered_sum;
 
1097	struct btrfs_ordered_extent *ordered;
1098	struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
1099	unsigned long num_sectors;
1100	unsigned long i;
1101	u32 sectorsize = btrfs_inode_sectorsize(inode);
1102	int index = 0;
1103
1104	ordered = btrfs_lookup_ordered_extent(inode, offset);
1105	if (!ordered)
1106		return 0;
1107
1108	spin_lock_irq(&tree->lock);
1109	list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
1110		if (disk_bytenr >= ordered_sum->bytenr &&
1111		    disk_bytenr < ordered_sum->bytenr + ordered_sum->len) {
1112			i = (disk_bytenr - ordered_sum->bytenr) >>
1113			    inode->i_sb->s_blocksize_bits;
1114			num_sectors = ordered_sum->len >>
1115				      inode->i_sb->s_blocksize_bits;
1116			num_sectors = min_t(int, len - index, num_sectors - i);
1117			memcpy(sum + index, ordered_sum->sums + i,
1118			       num_sectors);
1119
1120			index += (int)num_sectors;
1121			if (index == len)
1122				goto out;
1123			disk_bytenr += num_sectors * sectorsize;
1124		}
1125	}
1126out:
1127	spin_unlock_irq(&tree->lock);
1128	btrfs_put_ordered_extent(ordered);
1129	return index;
1130}
1131
1132int __init ordered_data_init(void)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1133{
1134	btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
1135				     sizeof(struct btrfs_ordered_extent), 0,
1136				     SLAB_MEM_SPREAD,
1137				     NULL);
1138	if (!btrfs_ordered_extent_cache)
1139		return -ENOMEM;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1140
1141	return 0;
1142}
1143
1144void __cold ordered_data_exit(void)
1145{
1146	kmem_cache_destroy(btrfs_ordered_extent_cache);
1147}