configfs: add missing mutex_unlock()

d_alloc() failure in configfs_register_subsystem() would fail to unlock
the mutex taken above.  Reorganize the exit path to ensure the unlock
happens.

Reported-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

1 files changed, 12 insertions, 15 deletions

diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index 34750d5e4ff2..5e6e37e58f36 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -1141,25 +1141,22 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys)
 
         err = -ENOMEM;
         dentry = d_alloc(configfs_sb->s_root, &name);
-        if (!dentry)
-                goto out_release;
-
-        d_add(dentry, NULL);
+        if (dentry) {
+                d_add(dentry, NULL);
 
-        err = configfs_attach_group(sd->s_element, &group->cg_item,
-                                    dentry);
-        if (!err)
-                dentry = NULL;
-        else
-                d_delete(dentry);
+                err = configfs_attach_group(sd->s_element, &group->cg_item,
+                                            dentry);
+                if (err) {
+                        d_delete(dentry);
+                        dput(dentry);
+                }
+        }
 
         mutex_unlock(&configfs_sb->s_root->d_inode->i_mutex);
 
-        if (dentry) {
-            dput(dentry);
-out_release:
-            unlink_group(group);
-            configfs_release_fs();
+        if (err) {
+                unlink_group(group);
+                configfs_release_fs();
         }
 
         return err;