Btrfs: add pinned extents to on-disk free space cache correctly

I got this while running xfstests:

[24256.836098] block group 317849600 has an wrong amount of free space
[24256.836100] btrfs: failed to load free space cache for block group 317849600

We should clamp the extent returned by find_first_extent_bit(),
so the start of the extent won't smaller than the start of the
block group.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
This commit is contained in:
Li Zefan 2012-01-10 16:41:01 +08:00
parent d25223a0d2
commit db804f23a7

View File

@ -838,7 +838,7 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
struct io_ctl io_ctl;
struct list_head bitmap_list;
struct btrfs_key key;
u64 start, end, len;
u64 start, extent_start, extent_end, len;
int entries = 0;
int bitmaps = 0;
int ret;
@ -857,25 +857,12 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
struct btrfs_free_cluster,
block_group_list);
/*
* We shouldn't have switched the pinned extents yet so this is the
* right one
*/
unpin = root->fs_info->pinned_extents;
/* Lock all pages first so we can lock the extent safely. */
io_ctl_prepare_pages(&io_ctl, inode, 0);
lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
0, &cached_state, GFP_NOFS);
/*
* When searching for pinned extents, we need to start at our start
* offset.
*/
if (block_group)
start = block_group->key.objectid;
node = rb_first(&ctl->free_space_offset);
if (!node && cluster) {
node = rb_first(&cluster->root);
@ -918,9 +905,20 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
* We want to add any pinned extents to our free space cache
* so we don't leak the space
*/
/*
* We shouldn't have switched the pinned extents yet so this is the
* right one
*/
unpin = root->fs_info->pinned_extents;
if (block_group)
start = block_group->key.objectid;
while (block_group && (start < block_group->key.objectid +
block_group->key.offset)) {
ret = find_first_extent_bit(unpin, start, &start, &end,
ret = find_first_extent_bit(unpin, start,
&extent_start, &extent_end,
EXTENT_DIRTY);
if (ret) {
ret = 0;
@ -928,20 +926,21 @@ int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
}
/* This pinned extent is out of our range */
if (start >= block_group->key.objectid +
if (extent_start >= block_group->key.objectid +
block_group->key.offset)
break;
len = block_group->key.objectid +
block_group->key.offset - start;
len = min(len, end + 1 - start);
extent_start = max(extent_start, start);
extent_end = min(block_group->key.objectid +
block_group->key.offset, extent_end + 1);
len = extent_end - extent_start;
entries++;
ret = io_ctl_add_entry(&io_ctl, start, len, NULL);
ret = io_ctl_add_entry(&io_ctl, extent_start, len, NULL);
if (ret)
goto out_nospc;
start = end + 1;
start = extent_end;
}
/* Write out the bitmaps */