From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8D7B9C433F5 for ; Tue, 23 Nov 2021 23:28:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231185AbhKWXcD (ORCPT ); Tue, 23 Nov 2021 18:32:03 -0500 Received: from mail.kernel.org ([198.145.29.99]:38248 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229890AbhKWXcD (ORCPT ); Tue, 23 Nov 2021 18:32:03 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 561ED6023D; Tue, 23 Nov 2021 23:28:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1637710134; bh=C/zjaKaSiUPuwAqwNvwAXf3Qg3jd9jyIJJ9pqMhNkkc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=UTSo6knJdPeoyf0/2Oht9Py5FBZPHq/jiWOPxCpDro2uGvVgM6W+9m/+S91RL0a6Z 2wq+FMQUMSt4OQ9h4h2/qZdq99AymqlWuZlbBim4c1hpMOYl7dHJKXFzFvn+5/yFwj NG6GEJqpL4mFgFs45B4m2GrMQN2phq38ZDZzBalK2cO82qXY4YgjOes+phEob6voaE FTn41vu4nI+eZr4RJWsJO83AC45sXhJoB00NXvYNEIsfWyqbAUA8tY+2f72PMYhkhk KSrZ3pxcD8bvFmtWzb4i5NkCdtvAHYgjwQjyHXol4e1LKa5PecQRu6Sn7iJ3bCcF8x QFyqO1GvwJLNw== Date: Tue, 23 Nov 2021 15:28:53 -0800 From: "Darrick J. Wong" To: Allison Henderson Cc: linux-xfs@vger.kernel.org Subject: Re: [PATCH v25 02/12] xfs: don't commit the first deferred transaction without intents Message-ID: <20211123232853.GX266024@magnolia> References: <20211117041343.3050202-1-allison.henderson@oracle.com> <20211117041343.3050202-3-allison.henderson@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211117041343.3050202-3-allison.henderson@oracle.com> Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Tue, Nov 16, 2021 at 09:13:33PM -0700, Allison Henderson wrote: > If the first operation in a string of defer ops has no intents, > then there is no reason to commit it before running the first call > to xfs_defer_finish_one(). This allows the defer ops to be used > effectively for non-intent based operations without requiring an > unnecessary extra transaction commit when first called. > > This fixes a regression in per-attribute modification transaction > count when delayed attributes are not being used. > > Signed-off-by: Dave Chinner > Signed-off-by: Allison Henderson > --- > fs/xfs/libxfs/xfs_defer.c | 29 +++++++++++++++++------------ > 1 file changed, 17 insertions(+), 12 deletions(-) > > diff --git a/fs/xfs/libxfs/xfs_defer.c b/fs/xfs/libxfs/xfs_defer.c > index 6dac8d6b8c21..51574f0371b5 100644 > --- a/fs/xfs/libxfs/xfs_defer.c > +++ b/fs/xfs/libxfs/xfs_defer.c > @@ -187,7 +187,7 @@ static const struct xfs_defer_op_type *defer_op_types[] = { > [XFS_DEFER_OPS_TYPE_AGFL_FREE] = &xfs_agfl_free_defer_type, > }; > > -static void > +static bool > xfs_defer_create_intent( > struct xfs_trans *tp, > struct xfs_defer_pending *dfp, > @@ -198,6 +198,7 @@ xfs_defer_create_intent( > if (!dfp->dfp_intent) > dfp->dfp_intent = ops->create_intent(tp, &dfp->dfp_work, > dfp->dfp_count, sort); > + return dfp->dfp_intent; Nit: This ought to be "return dfp->dfp_intent != NULL" to reinforce that we're returning whether or not the dfp has an associated log item vs. returning the actual log item. > } > > /* > @@ -205,16 +206,18 @@ xfs_defer_create_intent( > * associated extents, then add the entire intake list to the end of > * the pending list. > */ > -STATIC void > +STATIC bool > xfs_defer_create_intents( > struct xfs_trans *tp) > { > struct xfs_defer_pending *dfp; > + bool ret = false; > > list_for_each_entry(dfp, &tp->t_dfops, dfp_list) { > trace_xfs_defer_create_intent(tp->t_mountp, dfp); > - xfs_defer_create_intent(tp, dfp, true); > + ret |= xfs_defer_create_intent(tp, dfp, true); > } > + return ret; > } > > /* Abort all the intents that were committed. */ > @@ -488,7 +491,7 @@ int > xfs_defer_finish_noroll( > struct xfs_trans **tp) > { > - struct xfs_defer_pending *dfp; > + struct xfs_defer_pending *dfp = NULL; > int error = 0; > LIST_HEAD(dop_pending); > > @@ -507,17 +510,19 @@ xfs_defer_finish_noroll( > * of time that any one intent item can stick around in memory, > * pinning the log tail. > */ > - xfs_defer_create_intents(*tp); > + bool has_intents = xfs_defer_create_intents(*tp); > list_splice_init(&(*tp)->t_dfops, &dop_pending); > > - error = xfs_defer_trans_roll(tp); > - if (error) > - goto out_shutdown; > + if (has_intents || dfp) { I can't help but wonder if it would be simpler to make the xattr code walk through the delattr state machine until there's actually an intent to log? I forget, which patch in this series actually sets up this situation? Atomic extent swapping sort of has a similar situation in that the first transaction logs the inode core update and the swapext intent item, and that's it. --D > + error = xfs_defer_trans_roll(tp); > + if (error) > + goto out_shutdown; > > - /* Possibly relog intent items to keep the log moving. */ > - error = xfs_defer_relog(tp, &dop_pending); > - if (error) > - goto out_shutdown; > + /* Possibly relog intent items to keep the log moving. */ > + error = xfs_defer_relog(tp, &dop_pending); > + if (error) > + goto out_shutdown; > + } > > dfp = list_first_entry(&dop_pending, struct xfs_defer_pending, > dfp_list); > -- > 2.25.1 >