Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965787AbcCPIHS (ORCPT ); Wed, 16 Mar 2016 04:07:18 -0400 Received: from mail.kernel.org ([198.145.29.136]:58968 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965457AbcCPIHK (ORCPT ); Wed, 16 Mar 2016 04:07:10 -0400 From: lizf@kernel.org To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Michal Hocko , "Theodore Ts'o" , Zefan Li Subject: [PATCH 3.4 005/107] ext4: replace open coded nofail allocation in ext4_free_blocks() Date: Wed, 16 Mar 2016 16:04:59 +0800 Message-Id: <1458115601-5762-5-git-send-email-lizf@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1458115541-5712-1-git-send-email-lizf@kernel.org> References: <1458115541-5712-1-git-send-email-lizf@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1601 Lines: 52 From: Michal Hocko 3.4.111-rc1 review patch. If anyone has any objections, please let me know. ------------------ commit 7444a072c387a93ebee7066e8aee776954ab0e41 upstream. ext4_free_blocks is looping around the allocation request and mimics __GFP_NOFAIL behavior without any allocation fallback strategy. Let's remove the open coded loop and replace it with __GFP_NOFAIL. Without the flag the allocator has no way to find out never-fail requirement and cannot help in any way. Signed-off-by: Michal Hocko Signed-off-by: Theodore Ts'o Signed-off-by: Zefan Li --- fs/ext4/mballoc.c | 16 +++++----------- 1 file changed, 5 insertions(+), 11 deletions(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index cdfc763..46e6562 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4643,18 +4643,12 @@ do_more: /* * blocks being freed are metadata. these blocks shouldn't * be used until this transaction is committed + * + * We use __GFP_NOFAIL because ext4_free_blocks() is not allowed + * to fail. */ - retry: - new_entry = kmem_cache_alloc(ext4_free_data_cachep, GFP_NOFS); - if (!new_entry) { - /* - * We use a retry loop because - * ext4_free_blocks() is not allowed to fail. - */ - cond_resched(); - congestion_wait(BLK_RW_ASYNC, HZ/50); - goto retry; - } + new_entry = kmem_cache_alloc(ext4_free_data_cachep, + GFP_NOFS|__GFP_NOFAIL); new_entry->efd_start_cluster = bit; new_entry->efd_group = block_group; new_entry->efd_count = count_clusters; -- 1.9.1