diff mbox

Btrfs: avoid unnecessary switch of path locks to blocking mode

Message ID 1406572637-13766-1-git-send-email-fdmanana@suse.com (mailing list archive)
State Accepted
Headers show

Commit Message

Filipe Manana July 28, 2014, 6:37 p.m. UTC
If we need to cow a node, increase the write lock level and retry the
tree search, there's no point of changing the node locks in our path
to blocking mode, as we only waste time and unnecessarily wake up other
tasks waiting on the spinning locks (just to block them again shortly
after) because we release our path before repeating the tree search.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
---
 fs/btrfs/ctree.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
diff mbox

Patch

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index bd0ae3e..783ea3b 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -2792,8 +2792,6 @@  again:
 			if (!should_cow_block(trans, root, b))
 				goto cow_done;
 
-			btrfs_set_path_blocking(p);
-
 			/*
 			 * must have write locks on this node and the
 			 * parent
@@ -2807,6 +2805,7 @@  again:
 				goto again;
 			}
 
+			btrfs_set_path_blocking(p);
 			err = btrfs_cow_block(trans, root, b,
 					      p->nodes[level + 1],
 					      p->slots[level + 1], &b);