Btrfs: skip locking when searching commit root
We won't change commit root, skip locking dance with commit root
when walking backrefs, this can speed up btrfs send operations.
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index a88da72..860f4f2 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -873,8 +873,10 @@
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
- if (!trans)
+ if (!trans) {
path->search_commit_root = 1;
+ path->skip_locking = 1;
+ }
/*
* grab both a lock on the path and a lock on the delayed ref head.