configfs: Fix a reference leak in configfs_mkdir().

configfs_mkdir() failed to release the working parent reference in most
exit paths.  Also changed the exit path for readability.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

1 files changed, 26 insertions, 11 deletions

diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index 5638c8f9362..810c1395d6b 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -704,13 +704,18 @@ static int configfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
         struct module *owner;
         char *name;
 
-        if (dentry->d_parent == configfs_sb->s_root)
-                return -EPERM;
+        if (dentry->d_parent == configfs_sb->s_root) {
+                ret = -EPERM;
+                goto out;
+        }
 
         sd = dentry->d_parent->d_fsdata;
-        if (!(sd->s_type & CONFIGFS_USET_DIR))
-                return -EPERM;
+        if (!(sd->s_type & CONFIGFS_USET_DIR)) {
+                ret = -EPERM;
+                goto out;
+        }
 
+        /* Get a working ref for the duration of this function */
         parent_item = configfs_get_config_item(dentry->d_parent);
         type = parent_item->ci_type;
         subsys = to_config_group(parent_item)->cg_subsys;
@@ -719,15 +724,16 @@ static int configfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
         if (!type || !type->ct_group_ops ||
             (!type->ct_group_ops->make_group &&
              !type->ct_group_ops->make_item)) {
-                config_item_put(parent_item);
-                return -EPERM;  /* What lack-of-mkdir returns */
+                ret = -EPERM;  /* Lack-of-mkdir returns -EPERM */
+                goto out_put;
         }
 
         name = kmalloc(dentry->d_name.len + 1, GFP_KERNEL);
         if (!name) {
-                config_item_put(parent_item);
-                return -ENOMEM;
+                ret = -ENOMEM;
+                goto out_put;
         }
+
         snprintf(name, dentry->d_name.len + 1, "%s", dentry->d_name.name);
 
         down(&subsys->su_sem);
@@ -748,8 +754,8 @@ static int configfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 
         kfree(name);
         if (!item) {
-                config_item_put(parent_item);
-                return -ENOMEM;
+                ret = -ENOMEM;
+                goto out_put;
         }
 
         ret = -EINVAL;
@@ -776,12 +782,19 @@ static int configfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
                                 client_drop_item(parent_item, item);
                                 up(&subsys->su_sem);
 
-                                config_item_put(parent_item);
                                 module_put(owner);
                         }
                 }
         }
 
+out_put:
+        /*
+         * link_obj()/link_group() took a reference from child->parent.
+         * Drop our working ref
+         */
+        config_item_put(parent_item);
+
+out:
         return ret;
 }
 
@@ -801,6 +814,7 @@ static int configfs_rmdir(struct inode *dir, struct dentry *dentry)
         if (sd->s_type & CONFIGFS_USET_DEFAULT)
                 return -EPERM;
 
+        /* Get a working ref until we have the child */
         parent_item = configfs_get_config_item(dentry->d_parent);
         subsys = to_config_group(parent_item)->cg_subsys;
         BUG_ON(!subsys);
@@ -817,6 +831,7 @@ static int configfs_rmdir(struct inode *dir, struct dentry *dentry)
                 return ret;
         }
 
+        /* Get a working ref for the duration of this function */
         item = configfs_get_config_item(dentry);
 
         /* Drop reference from above, item already holds one. */