diff options
| author | Josef Bacik <jbacik@fusionio.com> | 2013-09-24 14:09:34 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-12-20 07:49:08 -0800 |
| commit | 794d0e92d22e8dd6495d22674272e17fd3cc33fa (patch) | |
| tree | 43dab278ba9718b882a20d3c5ad27f6cdd030f87 | |
| parent | dd1bb90a43e858e478d71079877f5df1d6758f08 (diff) | |
Btrfs: do a full search everytime in btrfs_search_old_slot
commit d4b4087c43cc00a196c5be57fac41f41309f1d56 upstream.
While running some snashot aware defrag tests I noticed I was panicing every
once and a while in key_search. This is because of the optimization that says
if we find a key at slot 0 it will be at slot 0 all the way down the rest of the
tree. This isn't the case for btrfs_search_old_slot since it will likely replay
changes to a buffer if something has changed since we took our sequence number.
So short circuit this optimization by setting prev_cmp to -1 every time we call
key_search so we will do our normal binary search. With this patch I am no
longer seeing the panics I was seeing before. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/btrfs/ctree.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 61b5bcd57b7e..b544a44d696e 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -2758,7 +2758,7 @@ int btrfs_search_old_slot(struct btrfs_root *root, struct btrfs_key *key, int level; int lowest_unlock = 1; u8 lowest_level = 0; - int prev_cmp; + int prev_cmp = -1; lowest_level = p->lowest_level; WARN_ON(p->nodes[0] != NULL); @@ -2769,7 +2769,6 @@ int btrfs_search_old_slot(struct btrfs_root *root, struct btrfs_key *key, } again: - prev_cmp = -1; b = get_old_root(root, time_seq); level = btrfs_header_level(b); p->locks[level] = BTRFS_READ_LOCK; @@ -2787,6 +2786,11 @@ again: */ btrfs_unlock_up_safe(p, level + 1); + /* + * Since we can unwind eb's we want to do a real search every + * time. + */ + prev_cmp = -1; ret = key_search(b, key, level, &prev_cmp, &slot); if (level != 0) { |