xfs: free the item in xfs_mru_cache_insert on failure

Call the provided free_func when xfs_mru_cache_insert as that's what
the callers need to do anyway.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

Author: Christoph Hellwig

fs/xfs/xfs_filestream.c

@@ -304,26 +304,19 @@ xfs_filestream_create_association(
 	 * for us, so all we need to do here is take another active reference to
 	 * the perag for the cached association.
 	 *
-	 * If we fail to store the association, we need to drop the fstrms
-	 * counter as well as drop the perag reference we take here for the
-	 * item. We do not need to return an error for this failure - as long as
-	 * we return a referenced AG, the allocation can still go ahead just
-	 * fine.
+	 * If we fail to store the association, we do not need to return an
+	 * error for this failure - as long as we return a referenced AG, the
+	 * allocation can still go ahead just fine.
 	 */
 	item = kmalloc(sizeof(*item), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
 	if (!item)
 		goto out_put_fstrms;
 
 	atomic_inc(&pag_group(args->pag)->xg_active_ref);
 	item->pag = args->pag;
-	error = xfs_mru_cache_insert(mp->m_filestream, pino, &item->mru);
-	if (error)
-		goto out_free_item;
+	xfs_mru_cache_insert(mp->m_filestream, pino, &item->mru);
 	return 0;
 
-out_free_item:
-	xfs_perag_rele(item->pag);
-	kfree(item);
 out_put_fstrms:
 	atomic_dec(&args->pag->pagf_fstrms);
 	return 0;

fs/xfs/xfs_mru_cache.c

@@ -414,21 +414,24 @@ xfs_mru_cache_destroy(
  * To insert an element, call xfs_mru_cache_insert() with the data store, the
  * element's key and the client data pointer.  This function returns 0 on
  * success or ENOMEM if memory for the data element couldn't be allocated.
+ *
+ * The passed in elem is freed through the per-cache free_func on failure.
  */
 int
 xfs_mru_cache_insert(
 	struct xfs_mru_cache	*mru,
 	unsigned long		key,
 	struct xfs_mru_cache_elem *elem)
 {
-	int			error;
+	int			error = -EINVAL;
 
 	ASSERT(mru && mru->lists);
 	if (!mru || !mru->lists)
-		return -EINVAL;
+		goto out_free;
 
+	error = -ENOMEM;
 	if (radix_tree_preload(GFP_KERNEL))
-		return -ENOMEM;
+		goto out_free;
 
 	INIT_LIST_HEAD(&elem->list_node);
 	elem->key = key;
@@ -440,6 +443,12 @@ xfs_mru_cache_insert(
 		_xfs_mru_cache_list_insert(mru, elem);
 	spin_unlock(&mru->lock);
 
+	if (error)
+		goto out_free;
+	return 0;
+
+out_free:
+	mru->free_func(mru->data, elem);
 	return error;
 }