ceph: avoid useless dget/dput in encode_fh

Nothing we do here sleeps, so just do it under d_lock and avoid the dget/
dput entirely.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Sage Weil <sage@newdream.net>

diff --git a/fs/ceph/export.c b/fs/ceph/export.c
index 9fbcdec..fbb2a64 100644 (file)
--- a/fs/ceph/export.c
+++ b/fs/ceph/export.c
@@ -56,9 +56,7 @@ static int ceph_encode_fh(struct dentry *dentry, u32 *rawfh, int *max_len,
                return -EINVAL;
 
        spin_lock(&dentry->d_lock);
-       parent = dget(dentry->d_parent);
-       spin_unlock(&dentry->d_lock);
-
+       parent = dentry->d_parent;
        if (*max_len >= connected_handle_length) {
                dout("encode_fh %p connectable\n", dentry);
                cfh->ino = ceph_ino(dentry->d_inode);
@@ -81,7 +79,7 @@ static int ceph_encode_fh(struct dentry *dentry, u32 *rawfh, int *max_len,
                *max_len = handle_length;
                type = 255;
        }
-       dput(parent);
+       spin_unlock(&dentry->d_lock);
        return type;
 }