From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (Postfix) with ESMTP id C163B7F7B for ; Thu, 5 Dec 2013 14:45:59 -0600 (CST) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay1.corp.sgi.com (Postfix) with ESMTP id A4D728F804B for ; Thu, 5 Dec 2013 12:45:59 -0800 (PST) Received: from ipmail04.adl6.internode.on.net (ipmail04.adl6.internode.on.net [150.101.137.141]) by cuda.sgi.com with ESMTP id 34HlYr1t0DEdWV5V for ; Thu, 05 Dec 2013 12:45:58 -0800 (PST) Date: Fri, 6 Dec 2013 07:45:38 +1100 From: Dave Chinner Subject: Re: [PATCH 3/5] xfs: use xfs_ilock_map_shared in xfs_qm_dqiterate Message-ID: <20131205204538.GC29897@dastard> References: <20131205155830.620826868@bombadil.infradead.org> <20131205155951.506063990@bombadil.infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20131205155951.506063990@bombadil.infradead.org> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Christoph Hellwig Cc: xfs@oss.sgi.com On Thu, Dec 05, 2013 at 07:58:33AM -0800, Christoph Hellwig wrote: > We might not have read in the extent list at this point, so make sure we > take the ilock exclusively if we have to do so. > > Signed-off-by: Christoph Hellwig > > Index: xfs/fs/xfs/xfs_qm.c > =================================================================== > --- xfs.orig/fs/xfs/xfs_qm.c 2013-11-18 14:39:01.967589998 +0100 > +++ xfs/fs/xfs/xfs_qm.c 2013-12-05 12:32:36.623617997 +0100 > @@ -1193,16 +1193,18 @@ xfs_qm_dqiterate( > lblkno = 0; > maxlblkcnt = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes); > do { > + uint lock_mode; > + > nmaps = XFS_DQITER_MAP_SIZE; > /* > * We aren't changing the inode itself. Just changing > * some of its data. No new blocks are added here, and > * the inode is never added to the transaction. > */ > - xfs_ilock(qip, XFS_ILOCK_SHARED); > + lock_mode = xfs_ilock_map_shared(qip); > error = xfs_bmapi_read(qip, lblkno, maxlblkcnt - lblkno, > map, &nmaps, 0); > - xfs_iunlock(qip, XFS_ILOCK_SHARED); > + xfs_iunlock_map_shared(qip, lock_mode); > if (error) > break; There's no bug here - this comes from quotacheck, which is guaranteed to have exclusive access to the filesystem at this point. Hence there's no-one to race with reading the extent list. Still, it doesn't hurt. Reviewed-by: Dave Chinner -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs