ocfs2: Add missing iput() during error handling in ocfs2_dentry_attach_lock()

In ocfs2_dentry_attach_lock(), if unable to get the dentry lock, we need to
call iput(inode) because a failure here means no d_instantiate(), which means
the normally matching iput() will not be called during dput(dentry).

This patch fixes the oops that accompanies the following message:
(3996,1):dlm_empty_lockres:2708 ERROR: lockres W00000000000000000a1046b06a4382 still has local locks!
kernel BUG in dlm_empty_lockres at /rpmbuild/smushran/BUILD/ocfs2-1.4.2/fs/ocfs2/dlm/dlmmaster.c:2709!

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/fs/ocfs2/dcache.c b/fs/ocfs2/dcache.c
index 7d604480557a..b574431a031d 100644
--- a/fs/ocfs2/dcache.c
+++ b/fs/ocfs2/dcache.c
@@ -290,6 +290,21 @@ out_attach:
         else
                 mlog_errno(ret);
 
+        /*
+         * In case of error, manually free the allocation and do the iput().
+         * We need to do this because error here means no d_instantiate(),
+         * which means iput() will not be called during dput(dentry).
+         */
+        if (ret < 0 && !alias) {
+                ocfs2_lock_res_free(&dl->dl_lockres);
+                BUG_ON(dl->dl_count != 1);
+                spin_lock(&dentry_attach_lock);
+                dentry->d_fsdata = NULL;
+                spin_unlock(&dentry_attach_lock);
+                kfree(dl);
+                iput(inode);
+        }
+
         dput(alias);
 
         return ret;