From 5124e00ec5b0be56155a11aec416fcc5125339f1 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Wed, 7 Nov 2012 13:44:13 -0500 Subject: [PATCH] Btrfs: only unlock and relock if we have to I noticed while doing fsync tests that we were always dropping the path and re-searching when we first cow the log root even though we've already gotten the write lock on the root. That's because we don't take into account that there might not be a parent node, so fix the check to make sure there is actually a parent node before we undo all of this work for nothing. Thanks, Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/ctree.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index e7bea1d..c7b67cf 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -2564,7 +2564,10 @@ again: * must have write locks on this node and the * parent */ - if (level + 1 > write_lock_level) { + if (level > write_lock_level || + (level + 1 > write_lock_level && + level + 1 < BTRFS_MAX_LEVEL && + p->nodes[level + 1])) { write_lock_level = level + 1; btrfs_release_path(p); goto again; -- 2.7.4