From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp1040.oracle.com ([141.146.126.69]:17516 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754410AbdHYREF (ORCPT ); Fri, 25 Aug 2017 13:04:05 -0400 Date: Fri, 25 Aug 2017 10:04:01 -0700 From: "Darrick J. Wong" Subject: Re: [RFC PATCH] xfs: Properly retry failed dquot items in case of error during buffer writeback Message-ID: <20170825170400.GS4796@magnolia> References: <20170825120752.22553-1-cmaiolino@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170825120752.22553-1-cmaiolino@redhat.com> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Carlos Maiolino Cc: linux-xfs@vger.kernel.org On Fri, Aug 25, 2017 at 02:07:52PM +0200, Carlos Maiolino wrote: > Hi, > > Once the fix for inode item writeback errors is already queued > (d3a304b62), I believe it's time to fix the same problem in dquot code. > > Although there were no reports of users hitting this bug in dquot code > (at least none I've seen), the bug is there and I was already planning > to fix it when the correct approach to fix the inodes part was decided. > > So, this is an RFC patch to fix the same problem in dquot code, > regarding failed buffers being unable to be resubmitted once they are > flush locked. > > The semantics are quite similar to inode items path, although during > xfs_qm_dqflush_done(), I'm not sure if the changes I made are correct. > > Comments much appreciated :) > > > BTW, This patch should be applied only over branch xfs-4.14-merge, it requires > my previous patches, which are not in the master branch yet. Looks ok, but is there an xfstests case to cover this? --D > > Cheers. > > Signed-off-by: Carlos Maiolino > --- > fs/xfs/xfs_dquot.c | 11 ++++++++--- > fs/xfs/xfs_dquot_item.c | 37 +++++++++++++++++++++++++++++++++++-- > 2 files changed, 43 insertions(+), 5 deletions(-) > > diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c > index fd2ef8c2c9a7..8198c20212a2 100644 > --- a/fs/xfs/xfs_dquot.c > +++ b/fs/xfs/xfs_dquot.c > @@ -987,14 +987,19 @@ xfs_qm_dqflush_done( > * holding the lock before removing the dquot from the AIL. > */ > if ((lip->li_flags & XFS_LI_IN_AIL) && > - lip->li_lsn == qip->qli_flush_lsn) { > + (lip->li_lsn == qip->qli_flush_lsn) || > + lip->li_flags & XFS_LI_FAILED) { > > /* xfs_trans_ail_delete() drops the AIL lock. */ > spin_lock(&ailp->xa_lock); > - if (lip->li_lsn == qip->qli_flush_lsn) > + if (lip->li_lsn == qip->qli_flush_lsn) { > xfs_trans_ail_delete(ailp, lip, SHUTDOWN_CORRUPT_INCORE); > - else > + } else if (lip->li_flags & XFS_LI_FAILED) { > + xfs_clear_li_failed(lip); > spin_unlock(&ailp->xa_lock); > + } else { > + spin_unlock(&ailp->xa_lock); > + } > } > > /* > diff --git a/fs/xfs/xfs_dquot_item.c b/fs/xfs/xfs_dquot_item.c > index 2c7a1629e064..35fd6d71bc42 100644 > --- a/fs/xfs/xfs_dquot_item.c > +++ b/fs/xfs/xfs_dquot_item.c > @@ -137,6 +137,23 @@ xfs_qm_dqunpin_wait( > wait_event(dqp->q_pinwait, (atomic_read(&dqp->q_pincount) == 0)); > } > > +/* > + * Callback used to mark a buffer with XFS_LI_FAILED when items in the buffer > + * have been failed during writeback > + * > + * this informs the AIL that the dquot is already flush locked on the next push, > + * and acquires a hold on the buffer to ensure that it isn't reclaimed before > + * dirty data makes it to disk. > + */ > +STATIC void > +xfs_dquot_item_error( > + struct xfs_log_item *lip, > + struct xfs_buf *bp) > +{ > + ASSERT(XFS_DQ_IS_LOCKED(DQUOT_ITEM(lip)->qli_item)); > + xfs_set_li_failed(lip, bp); > +} > + > STATIC uint > xfs_qm_dquot_logitem_push( > struct xfs_log_item *lip, > @@ -144,13 +161,28 @@ xfs_qm_dquot_logitem_push( > __acquires(&lip->li_ailp->xa_lock) > { > struct xfs_dquot *dqp = DQUOT_ITEM(lip)->qli_dquot; > - struct xfs_buf *bp = NULL; > + struct xfs_buf *bp = lip->li_buf; > uint rval = XFS_ITEM_SUCCESS; > int error; > > if (atomic_read(&dqp->q_pincount) > 0) > return XFS_ITEM_PINNED; > > + /* > + * The buffer containing this item failed to be written back > + * previously. Resubmit the buffer for IO > + */ > + if (lip->li_flags & XFS_LI_FAILED) { > + if (!xfs_buf_trylock(bp)) > + return XFS_ITEM_LOCKED; > + > + if (!xfs_buf_resubmit_failed_buffers(bp, lip, buffer_list)) > + rval = XFS_ITEM_FLUSHING; > + > + xfs_buf_unlock(bp); > + return rval; > + } > + > if (!xfs_dqlock_nowait(dqp)) > return XFS_ITEM_LOCKED; > > @@ -242,7 +274,8 @@ static const struct xfs_item_ops xfs_dquot_item_ops = { > .iop_unlock = xfs_qm_dquot_logitem_unlock, > .iop_committed = xfs_qm_dquot_logitem_committed, > .iop_push = xfs_qm_dquot_logitem_push, > - .iop_committing = xfs_qm_dquot_logitem_committing > + .iop_committing = xfs_qm_dquot_logitem_committing, > + .iop_error = xfs_dquot_item_error > }; > > /* > -- > 2.13.5 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html