From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:59374 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727587AbfFNOHH (ORCPT ); Fri, 14 Jun 2019 10:07:07 -0400 Date: Fri, 14 Jun 2019 10:07:04 -0400 From: Brian Foster Subject: Re: [PATCH 14/14] xfs: poll waiting for quotacheck Message-ID: <20190614140704.GF26586@bfoster> References: <156032205136.3774243.15725828509940520561.stgit@magnolia> <156032214200.3774243.5594376006892480443.stgit@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <156032214200.3774243.5594376006892480443.stgit@magnolia> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: "Darrick J. Wong" Cc: linux-xfs@vger.kernel.org On Tue, Jun 11, 2019 at 11:49:02PM -0700, Darrick J. Wong wrote: > From: Darrick J. Wong > > Create a pwork destroy function that uses polling instead of > uninterruptible sleep to wait for work items to finish so that we can > touch the softlockup watchdog. IOWs, gross hack. > > Signed-off-by: Darrick J. Wong > --- > fs/xfs/xfs_iwalk.c | 3 +++ > fs/xfs/xfs_iwalk.h | 3 ++- > fs/xfs/xfs_pwork.c | 19 +++++++++++++++++++ > fs/xfs/xfs_pwork.h | 3 +++ > fs/xfs/xfs_qm.c | 2 +- > 5 files changed, 28 insertions(+), 2 deletions(-) > > ... > diff --git a/fs/xfs/xfs_pwork.c b/fs/xfs/xfs_pwork.c > index 8d0d5f130252..c2f02b710b8c 100644 > --- a/fs/xfs/xfs_pwork.c > +++ b/fs/xfs/xfs_pwork.c > @@ -13,6 +13,7 @@ > #include "xfs_trace.h" > #include "xfs_sysctl.h" > #include "xfs_pwork.h" > +#include > > /* > * Parallel Work Queue > @@ -46,6 +47,8 @@ xfs_pwork_work( > error = pctl->work_fn(pctl->mp, pwork); > if (error && !pctl->error) > pctl->error = error; > + atomic_dec(&pctl->nr_work); > + wake_up(&pctl->poll_wait); We could use atomic_dec_and_test() here to avoid some unnecessary wakeups. With that fixed up: Reviewed-by: Brian Foster > } > > /* > @@ -76,6 +79,8 @@ xfs_pwork_init( > pctl->work_fn = work_fn; > pctl->error = 0; > pctl->mp = mp; > + atomic_set(&pctl->nr_work, 0); > + init_waitqueue_head(&pctl->poll_wait); > > return 0; > } > @@ -88,6 +93,7 @@ xfs_pwork_queue( > { > INIT_WORK(&pwork->work, xfs_pwork_work); > pwork->pctl = pctl; > + atomic_inc(&pctl->nr_work); > queue_work(pctl->wq, &pwork->work); > } > > @@ -101,6 +107,19 @@ xfs_pwork_destroy( > return pctl->error; > } > > +/* > + * Wait for the work to finish by polling completion status and touch the soft > + * lockup watchdog. This is for callers such as mount which hold locks. > + */ > +void > +xfs_pwork_poll( > + struct xfs_pwork_ctl *pctl) > +{ > + while (wait_event_timeout(pctl->poll_wait, > + atomic_read(&pctl->nr_work) == 0, HZ) == 0) > + touch_softlockup_watchdog(); > +} > + > /* > * Return the amount of parallelism that the data device can handle, or 0 for > * no limit. > diff --git a/fs/xfs/xfs_pwork.h b/fs/xfs/xfs_pwork.h > index 4cf1a6f48237..ff93873df8d3 100644 > --- a/fs/xfs/xfs_pwork.h > +++ b/fs/xfs/xfs_pwork.h > @@ -18,6 +18,8 @@ struct xfs_pwork_ctl { > struct workqueue_struct *wq; > struct xfs_mount *mp; > xfs_pwork_work_fn work_fn; > + struct wait_queue_head poll_wait; > + atomic_t nr_work; > int error; > }; > > @@ -53,6 +55,7 @@ int xfs_pwork_init(struct xfs_mount *mp, struct xfs_pwork_ctl *pctl, > unsigned int nr_threads); > void xfs_pwork_queue(struct xfs_pwork_ctl *pctl, struct xfs_pwork *pwork); > int xfs_pwork_destroy(struct xfs_pwork_ctl *pctl); > +void xfs_pwork_poll(struct xfs_pwork_ctl *pctl); > unsigned int xfs_pwork_guess_datadev_parallelism(struct xfs_mount *mp); > > #endif /* __XFS_PWORK_H__ */ > diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c > index 8004c931c86e..8bb902125403 100644 > --- a/fs/xfs/xfs_qm.c > +++ b/fs/xfs/xfs_qm.c > @@ -1304,7 +1304,7 @@ xfs_qm_quotacheck( > flags |= XFS_PQUOTA_CHKD; > } > > - error = xfs_iwalk_threaded(mp, 0, xfs_qm_dqusage_adjust, 0, NULL); > + error = xfs_iwalk_threaded(mp, 0, xfs_qm_dqusage_adjust, 0, true, NULL); > if (error) > goto error_return; > >