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| author | Nikolay Borisov <nborisov@suse.com> | 2018-04-11 11:21:18 +0300 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2018-05-28 18:07:16 +0200 |
| commit | 1e7a14211bced7ac26f332b16338db88290e0ffd (patch) | |
| tree | 3570d5fac36a496a83b9ad27bd73ea748ecaa344 | |
| parent | b25f0d0012d11f2fb3df855fb62b86e5f63fdd68 (diff) | |
| download | lwn-1e7a14211bced7ac26f332b16338db88290e0ffd.tar.gz lwn-1e7a14211bced7ac26f332b16338db88290e0ffd.zip | |
btrfs: Fix lock release order
Locks should generally be released in the oppposite order they are
acquired. Generally lock acquisiton ordering is used to ensure
deadlocks don't happen. However, as becomes more complicated it's
best to also maintain proper unlock order so as to avoid possible dead
locks. This was found by code inspection and doesn't necessarily lead
to a deadlock scenario.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
| -rw-r--r-- | fs/btrfs/extent-tree.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 2f9432beb69c..cd2f5220577f 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -2597,8 +2597,8 @@ static int cleanup_ref_head(struct btrfs_trans_handle *trans, delayed_refs->num_heads--; rb_erase(&head->href_node, &delayed_refs->href_root); RB_CLEAR_NODE(&head->href_node); - spin_unlock(&delayed_refs->lock); spin_unlock(&head->lock); + spin_unlock(&delayed_refs->lock); atomic_dec(&delayed_refs->num_entries); trace_run_delayed_ref_head(fs_info, head, 0); |