When the test function is not defined in sget_fc(), we always need to allocate a new superblock. So there is no point in acquiring the sb_lock twice in this case. Optimize the !test case by pre-allocating the superblock first before acquring the lock. Signed-off-by: Waiman Long <longman@xxxxxxxxxx> --- fs/super.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/super.c b/fs/super.c index a6405d44d4ca..c2bd5c34a826 100644 --- a/fs/super.c +++ b/fs/super.c @@ -520,6 +520,8 @@ struct super_block *sget_fc(struct fs_context *fc, struct user_namespace *user_ns = fc->global ? &init_user_ns : fc->user_ns; int err; + if (!test) + s = alloc_super(fc->fs_type, fc->sb_flags, user_ns); retry: spin_lock(&sb_lock); if (test) { -- 2.27.0