[PATCH] btrfs: add missing initialization in btrfs_check_shared

[Edmund Nadolski <enadolski@suse.com>]

btrfs_check_shared calls find_parent_nodes in a loop. In each
iteration it passes in a share_check struct to request a check for
a shared extent.  The share_check::share_count must be re-initialized
to zero for each iteration in order to avoid using a stale count
value from the previous iteration, thus causing a false
shared extent indication.

Signed-off-by: Edmund Nadolski <enadolski@suse.com>
---
 fs/btrfs/backref.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 4e89598..4a33448 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -1519,6 +1519,7 @@ int btrfs_check_shared(struct btrfs_root *root, u64 inum, u64 bytenr)
 		if (!node)
 			break;
 		bytenr = node->val;
+		shared.share_count = 0;
 		cond_resched();
 	}
 
-- 
2.10.2