ncpfs: fix rename over directory with dangling references

ncpfs does not handle references to unlinked directories (or so it would
seem given the ncp_rmdir check).  Since it is also possible to rename over
an empty directory, perform the same check here.

CC: Petr Vandrovec <petr@vandrovec.name>
CC: linux-kernel@vger.kernel.org
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 9 insertions, 1 deletions

diff --git a/fs/ncpfs/dir.c b/fs/ncpfs/dir.c
index 81c287d105d5..9c51f621e901 100644
--- a/fs/ncpfs/dir.c
+++ b/fs/ncpfs/dir.c
@@ -1144,8 +1144,16 @@ static int ncp_rename(struct inode *old_dir, struct dentry *old_dentry,
                 old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
                 new_dentry->d_parent->d_name.name, new_dentry->d_name.name);
 
-        if (new_dentry->d_inode && S_ISDIR(new_dentry->d_inode->i_mode))
+        if (new_dentry->d_inode && S_ISDIR(new_dentry->d_inode->i_mode)) {
+                /*
+                 * fail with EBUSY if there are still references to this
+                 * directory.
+                 */
                 dentry_unhash(new_dentry);
+                error = -EBUSY;
+                if (!d_unhashed(new_dentry))
+                        goto out;
+        }
 
         ncp_age_dentry(server, old_dentry);
         ncp_age_dentry(server, new_dentry);