gfs2_atomic_open(): skip lookups on hashed dentry

hashed dentry can be passed to ->atomic_open() only if
a) it has just passed revalidation and
b) it's negative

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index fc8ac2e..8108b4f 100644 (file)
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -1244,6 +1244,9 @@ static int gfs2_atomic_open(struct inode *dir, struct dentry *dentry,
        struct dentry *d;
        bool excl = !!(flags & O_EXCL);
 
+       if (!d_unhashed(dentry))
+               goto skip_lookup;
+
        d = __gfs2_lookup(dir, dentry, file, opened);
        if (IS_ERR(d))
                return PTR_ERR(d);
@@ -1260,6 +1263,8 @@ static int gfs2_atomic_open(struct inode *dir, struct dentry *dentry,
        }
 
        BUG_ON(d != NULL);
+
+skip_lookup:
        if (!(flags & O_CREAT))
                return -ENOENT;