Btrfs: fix locking issue in btrfs_find_next_key

Browse source

When walking up the tree, btrfs_find_next_key assumes the upper level tree
block is properly locked. This isn't always true even path->keep_locks is 1.
This is because btrfs_find_next_key may advance path->slots[] several times
instead of only once.

When 'path->slots[level] >= btrfs_header_nritems(path->nodes[level])' is found,
we can't guarantee the original value of 'path->slots[level]' is
'btrfs_header_nritems(path->nodes[level]) - 1'. If it's not, the tree block at
'level + 1' isn't locked.

This patch fixes the issue by explicitly checking the locking state,
re-searching the tree if it's not locked.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

...

This commit is contained in:

Yan Zheng 2009-07-22 09:59:00 -04:00 • committed by Chris Mason

parent e457afec60

commit 33c66f430b

2 changed files with 65 additions and 33 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

95

fs/btrfs/ctree.c

View file

3

fs/btrfs/relocation.c

View file