cifs: release cached dentries only if mount is complete

[ Upstream commit d788e51636462e61c6883f7d96b07b06bc291650 ]

During cifs_kill_sb, we first dput all the dentries that we have cached.
However this function can also get called for mount failures.
So dput the cached dentries only if the filesystem mount is complete.
i.e. cifs_sb->root is populated.

Fixes: 5e9c89d43fa6 ("cifs: Grab a reference for the dentry of the cached directory during the lifetime of the cache")
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 6e5246122ee2cc46135d2da8e7319cf333cc4160..9f0f6bdb3a4dc8214d7ae21448460cf8a550f19d 100644 (file)
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -266,22 +266,24 @@ static void cifs_kill_sb(struct super_block *sb)
         * before we kill the sb.
         */
        if (cifs_sb->root) {
+               node = rb_first(root);
+               while (node != NULL) {
+                       tlink = rb_entry(node, struct tcon_link, tl_rbnode);
+                       tcon = tlink_tcon(tlink);
+                       cfid = &tcon->crfid;
+                       mutex_lock(&cfid->fid_mutex);
+                       if (cfid->dentry) {
+                               dput(cfid->dentry);
+                               cfid->dentry = NULL;
+                       }
+                       mutex_unlock(&cfid->fid_mutex);
+                       node = rb_next(node);
+               }
+
+               /* finally release root dentry */
                dput(cifs_sb->root);
                cifs_sb->root = NULL;
        }
-       node = rb_first(root);
-       while (node != NULL) {
-               tlink = rb_entry(node, struct tcon_link, tl_rbnode);
-               tcon = tlink_tcon(tlink);
-               cfid = &tcon->crfid;
-               mutex_lock(&cfid->fid_mutex);
-               if (cfid->dentry) {
-                       dput(cfid->dentry);
-                       cfid->dentry = NULL;
-               }
-               mutex_unlock(&cfid->fid_mutex);
-               node = rb_next(node);
-       }
 
        kill_anon_super(sb);
        cifs_umount(cifs_sb);