From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:49140 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727305AbfDWP2a (ORCPT ); Tue, 23 Apr 2019 11:28:30 -0400 Date: Tue, 23 Apr 2019 11:28:27 -0400 From: Brian Foster Subject: Re: [PATCH] xfs: make tr_growdata a permanent transaction Message-ID: <20190423152827.GB10224@bfoster> References: <20190423150709.GG4676@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190423150709.GG4676@magnolia> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: "Darrick J. Wong" Cc: linux-xfs@vger.kernel.org, Christoph Hellwig On Tue, Apr 23, 2019 at 08:07:09AM -0700, Darrick J. Wong wrote: > From: Brian Foster > > The growdata transaction is used by growfs operations to increase > the data size of the filesystem. Part of this sequence involves > extending the size of the last preexisting AG in the fs, if > necessary. This is implemented by freeing the newly available > physical range to the AG. > > tr_growdata is not a permanent transaction, however, and block > allocation transactions must be permanent to handle deferred frees > of AGFL blocks. If the grow operation extends an existing AG that > requires AGFL fixing, assert failures occur due to a populated dfops > list on a non-permanent transaction and the AGFL free does not > occur. This is reproduced (rarely) by xfs/104. > > Change tr_growdata to a permanent transaction with a default log > count. This increases initial transaction reservation size, but > growfs is an infrequent and non-performance critical operation and > so should have minimal impact. Also add an assert in the block > allocation path to make this transaction requirement explicit and > obvious to future callers. > We should drop the last sentence from this commit log too if we push the assert to its own patch. Brian > Reported-by: Darrick J. Wong > Signed-off-by: Brian Foster > Reviewed-by: Darrick J. Wong > [darrick: add a comment to the assert] > Signed-off-by: Darrick J. Wong > --- > fs/xfs/libxfs/xfs_trans_resv.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/fs/xfs/libxfs/xfs_trans_resv.c b/fs/xfs/libxfs/xfs_trans_resv.c > index f99a7aefe418..83f4ee2afc49 100644 > --- a/fs/xfs/libxfs/xfs_trans_resv.c > +++ b/fs/xfs/libxfs/xfs_trans_resv.c > @@ -876,9 +876,13 @@ xfs_trans_resv_calc( > resp->tr_sb.tr_logres = xfs_calc_sb_reservation(mp); > resp->tr_sb.tr_logcount = XFS_DEFAULT_LOG_COUNT; > > + /* growdata requires permanent res; it can free space to the last AG */ > + resp->tr_growdata.tr_logres = xfs_calc_growdata_reservation(mp); > + resp->tr_growdata.tr_logcount = XFS_DEFAULT_PERM_LOG_COUNT; > + resp->tr_growdata.tr_logflags |= XFS_TRANS_PERM_LOG_RES; > + > /* The following transaction are logged in logical format */ > resp->tr_ichange.tr_logres = xfs_calc_ichange_reservation(mp); > - resp->tr_growdata.tr_logres = xfs_calc_growdata_reservation(mp); > resp->tr_fsyncts.tr_logres = xfs_calc_swrite_reservation(mp); > resp->tr_writeid.tr_logres = xfs_calc_writeid_reservation(mp); > resp->tr_attrsetrt.tr_logres = xfs_calc_attrsetrt_reservation(mp);