From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH 4/6] writeback: fix writeback_inodes_wb from writeback_inodes_sb Date: Wed, 9 Jun 2010 14:25:52 +0200 Message-ID: <20100609122552.GA23216@lst.de> References: <20100608161424.GA11735@lst.de> <20100608161458.GE11735@lst.de> <4C0E9F4B.7090204@kernel.dk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Christoph Hellwig , linux-fsdevel@vger.kernel.org To: Jens Axboe Return-path: Received: from verein.lst.de ([213.95.11.210]:36394 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755939Ab0FIM0A (ORCPT ); Wed, 9 Jun 2010 08:26:00 -0400 Content-Disposition: inline In-Reply-To: <4C0E9F4B.7090204@kernel.dk> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Tue, Jun 08, 2010 at 09:51:39PM +0200, Jens Axboe wrote: > On 08/06/10 18.14, Christoph Hellwig wrote: > > When we call writeback_inodes_wb from writeback_inodes_sb we always have > > s_umount held, which currently makes the whole operation a no-op. > > > > But if we are called to write out inodes for a specific superblock we always > > have s_umount held, so replace the incorrect logic checking for WB_SYNC_ALL > > which only worked by coincidence with the proper check for an explicit > > superblock argument. > > This is tons better than the pinning, I like it a lot. Unfortunately I accidentally removed the requeue_io call when we fail to pin the inode. This leads to softlockups after heavy I/O load. Please fold the patch below into this one, or if not possible add it to the end of the series. --- From: Christoph Hellwig Subject: [PATCH] writeback: add missing requeue_io in writeback_inodes_wb In "writeback: fix writeback_inodes_wb from writeback_inodes_sb" I accidentally removed the requeue_io if we need to skip a superblock because we can't pin it. Add it back, otherwise we're getting spurious lockups after multiple xfstests runs. Signed-off-by: Christoph Hellwig Index: linux-2.6/fs/fs-writeback.c =================================================================== --- linux-2.6.orig/fs/fs-writeback.c 2010-06-09 12:09:42.462024800 +0200 +++ linux-2.6/fs/fs-writeback.c 2010-06-09 12:09:47.830005523 +0200 @@ -643,8 +643,10 @@ static void writeback_inodes_wb(struct b ret = writeback_sb_inodes(sb, wb, wbc); } else { - if (!pin_sb_for_writeback(sb)) + if (!pin_sb_for_writeback(sb)) { + requeue_io(inode); continue; + } ret = writeback_sb_inodes(sb, wb, wbc); drop_super(sb); }