ceph: avoid d_parent in ceph_dentry_hash; fix ceph_encode_fh() hashing bug

Have caller pass in a safely-obtained reference to the parent directory
for calculating a dentry's hash valud.

While we're here, simpify the flow through ceph_encode_fh() so that there
is a single exit point and cleanup.

Also fix a bug with the dentry hash calculation: calculate the hash for the
dentry we were given, not its parent.

Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>

1 files changed, 1 insertions, 2 deletions

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 31d27f8f8261..33a19df72288 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -1244,9 +1244,8 @@ void ceph_dentry_lru_del(struct dentry *dn)
  * Return name hash for a given dentry.  This is dependent on
  * the parent directory's hash function.
  */
-unsigned ceph_dentry_hash(struct dentry *dn)
+unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn)
 {
-        struct inode *dir = dn->d_parent->d_inode;
         struct ceph_inode_info *dci = ceph_inode(dir);
 
         switch (dci->i_dir_layout.dl_dir_hash) {