From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay2.corp.sgi.com [137.38.102.29]) by oss.sgi.com (Postfix) with ESMTP id 5C0D57F53 for ; Thu, 8 May 2014 08:36:45 -0500 (CDT) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by relay2.corp.sgi.com (Postfix) with ESMTP id 2AE96304059 for ; Thu, 8 May 2014 06:36:42 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by cuda.sgi.com with ESMTP id RCSe8YdgCzo1UnZJ for ; Thu, 08 May 2014 06:36:41 -0700 (PDT) Date: Thu, 8 May 2014 09:36:37 -0400 From: Brian Foster Subject: Re: [PATCH] xfs: remove XFS_TRANS_RESERVE in collapse range Message-ID: <20140508133637.GB47272@bfoster.bfoster> References: <002601cf6aa2$c59cd670$50d68350$@samsung.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <002601cf6aa2$c59cd670$50d68350$@samsung.com> 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: Namjae Jeon Cc: xfs@oss.sgi.com On Thu, May 08, 2014 at 06:49:14PM +0900, Namjae Jeon wrote: > There is no need to dip into reserve pool. Reserve pool is used for much > more important things. And xfs_trans_reserve will never return ENOSPC > because punch hole is already done. If we get ENOSPC, collapse range > will be simply failed. > > Signed-off-by: Namjae Jeon > Signed-off-by: Ashish Sangwan > --- > fs/xfs/xfs_bmap_util.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c > index 296160b..91a43c5 100644 > --- a/fs/xfs/xfs_bmap_util.c > +++ b/fs/xfs/xfs_bmap_util.c > @@ -1519,7 +1519,6 @@ xfs_collapse_file_space( > > while (!error && !done) { > tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT); > - tp->t_flags |= XFS_TRANS_RESERVE; Makes sense. > /* > * We would need to reserve permanent block for transaction. > * This will come into picture when after shifting extent into > @@ -1529,7 +1528,7 @@ xfs_collapse_file_space( > error = xfs_trans_reserve(tp, &M_RES(mp)->tr_write, > XFS_DIOSTRAT_SPACE_RES(mp, 0), 0); > if (error) { > - ASSERT(error == ENOSPC || XFS_FORCED_SHUTDOWN(mp)); > + ASSERT(XFS_FORCED_SHUTDOWN(mp)); The xfs_trans_reserve() call still reserves XFS_DIOSTRAT_SPACE_RES() blocks, so therefore I think ENOSPC is still a possibility. The question is probably whether or not we need to reserve blocks for this transaction. Making a pass through the code... we have the possibility of deleting a btree record in xfs_bmap_shift_extents(). This in turn could potentially free a btree block, which frees space. I _think_ this could mean we want to keep the block reservation because we update the free space trees, but I suppose that could be handled by the freelist... Perhaps Dave can confirm which direction we should go here..? Brian > xfs_trans_cancel(tp, 0); > break; > } > -- > 1.7.11-rc0 > > _______________________________________________ > xfs mailing list > xfs@oss.sgi.com > http://oss.sgi.com/mailman/listinfo/xfs _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs