From 1e7a14211bced7ac26f332b16338db88290e0ffd Mon Sep 17 00:00:00 2001 From: Nikolay Borisov Date: Wed, 11 Apr 2018 11:21:18 +0300 Subject: [PATCH] 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 Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/extent-tree.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) 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);