2 * Copyright (C) 2007 Oracle. All rights reserved.
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.
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.
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.
19 #include <linux/gfp.h>
20 #include <linux/slab.h>
21 #include <linux/blkdev.h>
23 #include "transaction.h"
24 #include "btrfs_inode.h"
25 #include "extent_io.h"
28 static u64 entry_end(struct btrfs_ordered_extent *entry)
30 if (entry->file_offset + entry->len < entry->file_offset)
32 return entry->file_offset + entry->len;
35 static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
38 struct rb_node ** p = &root->rb_node;
39 struct rb_node * parent = NULL;
40 struct btrfs_ordered_extent *entry;
44 entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
46 if (file_offset < entry->file_offset)
48 else if (file_offset >= entry_end(entry))
54 rb_link_node(node, parent, p);
55 rb_insert_color(node, root);
59 static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
60 struct rb_node **prev_ret)
62 struct rb_node * n = root->rb_node;
63 struct rb_node *prev = NULL;
65 struct btrfs_ordered_extent *entry;
66 struct btrfs_ordered_extent *prev_entry = NULL;
69 entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
73 if (file_offset < entry->file_offset)
75 else if (file_offset >= entry_end(entry))
83 while(prev && file_offset >= entry_end(prev_entry)) {
87 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
89 if (file_offset < entry_end(prev_entry))
95 prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
97 while(prev && file_offset < entry_end(prev_entry)) {
101 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
109 static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset)
111 if (file_offset < entry->file_offset ||
112 entry->file_offset + entry->len <= file_offset)
117 static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
120 struct rb_root *root = &tree->tree;
121 struct rb_node *prev;
123 struct btrfs_ordered_extent *entry;
126 entry = rb_entry(tree->last, struct btrfs_ordered_extent,
128 if (offset_in_entry(entry, file_offset))
131 ret = __tree_search(root, file_offset, &prev);
139 /* allocate and add a new ordered_extent into the per-inode tree.
140 * file_offset is the logical offset in the file
142 * start is the disk block number of an extent already reserved in the
143 * extent allocation tree
145 * len is the length of the extent
147 * This also sets the EXTENT_ORDERED bit on the range in the inode.
149 * The tree is given a single reference on the ordered extent that was
152 int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
155 struct btrfs_ordered_inode_tree *tree;
156 struct rb_node *node;
157 struct btrfs_ordered_extent *entry;
159 tree = &BTRFS_I(inode)->ordered_tree;
160 entry = kzalloc(sizeof(*entry), GFP_NOFS);
164 mutex_lock(&tree->mutex);
165 entry->file_offset = file_offset;
166 entry->start = start;
168 /* one ref for the tree */
169 atomic_set(&entry->refs, 1);
170 init_waitqueue_head(&entry->wait);
171 INIT_LIST_HEAD(&entry->list);
173 node = tree_insert(&tree->tree, file_offset,
176 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
177 atomic_inc(&entry->refs);
179 set_extent_ordered(&BTRFS_I(inode)->io_tree, file_offset,
180 entry_end(entry) - 1, GFP_NOFS);
182 mutex_unlock(&tree->mutex);
188 * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
189 * when an ordered extent is finished.
191 int btrfs_add_ordered_sum(struct inode *inode, struct btrfs_ordered_sum *sum)
193 struct btrfs_ordered_inode_tree *tree;
194 struct rb_node *node;
195 struct btrfs_ordered_extent *entry;
197 tree = &BTRFS_I(inode)->ordered_tree;
198 mutex_lock(&tree->mutex);
199 node = tree_search(tree, sum->file_offset);
202 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
203 BUG_ON(!offset_in_entry(entry, sum->file_offset));
205 list_add_tail(&sum->list, &entry->list);
206 mutex_unlock(&tree->mutex);
211 * this is used to account for finished IO across a given range
212 * of the file. The IO should not span ordered extents. If
213 * a given ordered_extent is completely done, 1 is returned, otherwise
216 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
217 * to make sure this function only returns 1 once for a given ordered extent.
219 int btrfs_dec_test_ordered_pending(struct inode *inode,
220 u64 file_offset, u64 io_size)
222 struct btrfs_ordered_inode_tree *tree;
223 struct rb_node *node;
224 struct btrfs_ordered_extent *entry;
225 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
228 tree = &BTRFS_I(inode)->ordered_tree;
229 mutex_lock(&tree->mutex);
230 clear_extent_ordered(io_tree, file_offset, file_offset + io_size - 1,
232 node = tree_search(tree, file_offset);
238 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
239 if (!offset_in_entry(entry, file_offset)) {
244 ret = test_range_bit(io_tree, entry->file_offset,
245 entry->file_offset + entry->len - 1,
248 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
250 mutex_unlock(&tree->mutex);
255 * used to drop a reference on an ordered extent. This will free
256 * the extent if the last reference is dropped
258 int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
260 struct list_head *cur;
261 struct btrfs_ordered_sum *sum;
263 if (atomic_dec_and_test(&entry->refs)) {
264 while(!list_empty(&entry->list)) {
265 cur = entry->list.next;
266 sum = list_entry(cur, struct btrfs_ordered_sum, list);
267 list_del(&sum->list);
276 * remove an ordered extent from the tree. No references are dropped
277 * but, anyone waiting on this extent is woken up.
279 int btrfs_remove_ordered_extent(struct inode *inode,
280 struct btrfs_ordered_extent *entry)
282 struct btrfs_ordered_inode_tree *tree;
283 struct rb_node *node;
285 tree = &BTRFS_I(inode)->ordered_tree;
286 mutex_lock(&tree->mutex);
287 node = &entry->rb_node;
288 rb_erase(node, &tree->tree);
290 set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
291 mutex_unlock(&tree->mutex);
292 wake_up(&entry->wait);
297 * Used to start IO or wait for a given ordered extent to finish.
299 * If wait is one, this effectively waits on page writeback for all the pages
300 * in the extent, and it waits on the io completion code to insert
301 * metadata into the btree corresponding to the extent
303 void btrfs_start_ordered_extent(struct inode *inode,
304 struct btrfs_ordered_extent *entry,
307 u64 start = entry->file_offset;
308 u64 end = start + entry->len - 1;
311 * pages in the range can be dirty, clean or writeback. We
312 * start IO on any dirty ones so the wait doesn't stall waiting
313 * for pdflush to find them
315 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
316 do_sync_file_range(file, start, end, SYNC_FILE_RANGE_WRITE);
318 do_sync_mapping_range(inode->i_mapping, start, end,
319 SYNC_FILE_RANGE_WRITE);
322 wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
327 * Used to wait on ordered extents across a large range of bytes.
329 void btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
332 struct btrfs_ordered_extent *ordered;
337 if (start + len < start)
340 end = start + len - 1;
343 ordered = btrfs_lookup_first_ordered_extent(inode, end);
347 if (ordered->file_offset >= start + len) {
348 btrfs_put_ordered_extent(ordered);
351 if (ordered->file_offset + ordered->len < start) {
352 btrfs_put_ordered_extent(ordered);
355 btrfs_start_ordered_extent(inode, ordered, should_wait);
357 end = ordered->file_offset;
358 btrfs_put_ordered_extent(ordered);
363 if (should_wait && found) {
371 * find an ordered extent corresponding to file_offset. return NULL if
372 * nothing is found, otherwise take a reference on the extent and return it
374 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
377 struct btrfs_ordered_inode_tree *tree;
378 struct rb_node *node;
379 struct btrfs_ordered_extent *entry = NULL;
381 tree = &BTRFS_I(inode)->ordered_tree;
382 mutex_lock(&tree->mutex);
383 node = tree_search(tree, file_offset);
387 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
388 if (!offset_in_entry(entry, file_offset))
391 atomic_inc(&entry->refs);
393 mutex_unlock(&tree->mutex);
398 * lookup and return any extent before 'file_offset'. NULL is returned
401 struct btrfs_ordered_extent *
402 btrfs_lookup_first_ordered_extent(struct inode * inode, u64 file_offset)
404 struct btrfs_ordered_inode_tree *tree;
405 struct rb_node *node;
406 struct btrfs_ordered_extent *entry = NULL;
408 tree = &BTRFS_I(inode)->ordered_tree;
409 mutex_lock(&tree->mutex);
410 node = tree_search(tree, file_offset);
414 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
415 atomic_inc(&entry->refs);
417 mutex_unlock(&tree->mutex);
422 * After an extent is done, call this to conditionally update the on disk
423 * i_size. i_size is updated to cover any fully written part of the file.
425 int btrfs_ordered_update_i_size(struct inode *inode,
426 struct btrfs_ordered_extent *ordered)
428 struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
429 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
433 struct rb_node *node;
434 struct btrfs_ordered_extent *test;
436 mutex_lock(&tree->mutex);
437 disk_i_size = BTRFS_I(inode)->disk_i_size;
440 * if the disk i_size is already at the inode->i_size, or
441 * this ordered extent is inside the disk i_size, we're done
443 if (disk_i_size >= inode->i_size ||
444 ordered->file_offset + ordered->len <= disk_i_size) {
449 * we can't update the disk_isize if there are delalloc bytes
450 * between disk_i_size and this ordered extent
452 if (test_range_bit(io_tree, disk_i_size,
453 ordered->file_offset + ordered->len - 1,
454 EXTENT_DELALLOC, 0)) {
458 * walk backward from this ordered extent to disk_i_size.
459 * if we find an ordered extent then we can't update disk i_size
462 node = &ordered->rb_node;
464 node = rb_prev(node);
467 test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
468 if (test->file_offset + test->len <= disk_i_size)
470 if (test->file_offset >= inode->i_size)
472 if (test->file_offset >= disk_i_size)
475 new_i_size = min_t(u64, entry_end(ordered), i_size_read(inode));
478 * at this point, we know we can safely update i_size to at least
479 * the offset from this ordered extent. But, we need to
480 * walk forward and see if ios from higher up in the file have
483 node = rb_next(&ordered->rb_node);
487 * do we have an area where IO might have finished
488 * between our ordered extent and the next one.
490 test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
491 if (test->file_offset > entry_end(ordered)) {
492 i_size_test = test->file_offset - 1;
495 i_size_test = i_size_read(inode);
499 * i_size_test is the end of a region after this ordered
500 * extent where there are no ordered extents. As long as there
501 * are no delalloc bytes in this area, it is safe to update
502 * disk_i_size to the end of the region.
504 if (i_size_test > entry_end(ordered) &&
505 !test_range_bit(io_tree, entry_end(ordered), i_size_test,
506 EXTENT_DELALLOC, 0)) {
507 new_i_size = min_t(u64, i_size_test, i_size_read(inode));
509 BTRFS_I(inode)->disk_i_size = new_i_size;
511 mutex_unlock(&tree->mutex);
516 * search the ordered extents for one corresponding to 'offset' and
517 * try to find a checksum. This is used because we allow pages to
518 * be reclaimed before their checksum is actually put into the btree
520 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u32 *sum)
522 struct btrfs_ordered_sum *ordered_sum;
523 struct btrfs_sector_sum *sector_sums;
524 struct btrfs_ordered_extent *ordered;
525 struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
526 struct list_head *cur;
530 ordered = btrfs_lookup_ordered_extent(inode, offset);
534 mutex_lock(&tree->mutex);
535 list_for_each_prev(cur, &ordered->list) {
536 ordered_sum = list_entry(cur, struct btrfs_ordered_sum, list);
537 if (offset >= ordered_sum->file_offset &&
538 offset < ordered_sum->file_offset + ordered_sum->len) {
539 index = (offset - ordered_sum->file_offset) /
540 BTRFS_I(inode)->root->sectorsize;;
541 sector_sums = &ordered_sum->sums;
542 *sum = sector_sums[index].sum;
548 mutex_unlock(&tree->mutex);