This is a note to let you know that I've just added the patch titled
xfs: trylock underlying buffer on dquot flush
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
xfs-trylock-underlying-buffer-on-dquot-flush.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Wed Oct 26 04:49:40 PM CEST 2022
From: Chandan Babu R <chandan.babu@xxxxxxxxxx>
Date: Wed, 26 Oct 2022 11:58:39 +0530
Subject: xfs: trylock underlying buffer on dquot flush
To: gregkh@xxxxxxxxxxxxxxxxxxx
Cc: sashal@xxxxxxxxxx, mcgrof@xxxxxxxxxx, linux-xfs@xxxxxxxxxxxxxxx, stable@xxxxxxxxxxxxxxx, djwong@xxxxxxxxxx, chandan.babu@xxxxxxxxxx, amir73il@xxxxxxxxx, leah.rumancik@xxxxxxxxx
Message-ID: <20221026062843.927600-23-chandan.babu@xxxxxxxxxx>
From: Brian Foster <bfoster@xxxxxxxxxx>
commit 8d3d7e2b35ea7d91d6e085c93b5efecfb0fba307 upstream.
A dquot flush currently blocks on the buffer lock for the underlying
dquot buffer. In turn, this causes xfsaild to block rather than
continue processing other items in the meantime. Update
xfs_qm_dqflush() to trylock the buffer, similar to how inode buffers
are handled, and return -EAGAIN if the lock fails. Fix up any
callers that don't currently handle the error properly.
Signed-off-by: Brian Foster <bfoster@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
Acked-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Signed-off-by: Chandan Babu R <chandan.babu@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/xfs/xfs_dquot.c | 6 +++---
fs/xfs/xfs_dquot_item.c | 3 ++-
fs/xfs/xfs_qm.c | 14 +++++++++-----
3 files changed, 14 insertions(+), 9 deletions(-)
--- a/fs/xfs/xfs_dquot.c
+++ b/fs/xfs/xfs_dquot.c
@@ -1105,8 +1105,8 @@ xfs_qm_dqflush(
* Get the buffer containing the on-disk dquot
*/
error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp, dqp->q_blkno,
- mp->m_quotainfo->qi_dqchunklen, 0, &bp,
- &xfs_dquot_buf_ops);
+ mp->m_quotainfo->qi_dqchunklen, XBF_TRYLOCK,
+ &bp, &xfs_dquot_buf_ops);
if (error)
goto out_unlock;
@@ -1176,7 +1176,7 @@ xfs_qm_dqflush(
out_unlock:
xfs_dqfunlock(dqp);
- return -EIO;
+ return error;
}
/*
--- a/fs/xfs/xfs_dquot_item.c
+++ b/fs/xfs/xfs_dquot_item.c
@@ -189,7 +189,8 @@ xfs_qm_dquot_logitem_push(
if (!xfs_buf_delwri_queue(bp, buffer_list))
rval = XFS_ITEM_FLUSHING;
xfs_buf_relse(bp);
- }
+ } else if (error == -EAGAIN)
+ rval = XFS_ITEM_LOCKED;
spin_lock(&lip->li_ailp->ail_lock);
out_unlock:
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -121,12 +121,11 @@ xfs_qm_dqpurge(
{
struct xfs_mount *mp = dqp->q_mount;
struct xfs_quotainfo *qi = mp->m_quotainfo;
+ int error = -EAGAIN;
xfs_dqlock(dqp);
- if ((dqp->dq_flags & XFS_DQ_FREEING) || dqp->q_nrefs != 0) {
- xfs_dqunlock(dqp);
- return -EAGAIN;
- }
+ if ((dqp->dq_flags & XFS_DQ_FREEING) || dqp->q_nrefs != 0)
+ goto out_unlock;
dqp->dq_flags |= XFS_DQ_FREEING;
@@ -139,7 +138,6 @@ xfs_qm_dqpurge(
*/
if (XFS_DQ_IS_DIRTY(dqp)) {
struct xfs_buf *bp = NULL;
- int error;
/*
* We don't care about getting disk errors here. We need
@@ -149,6 +147,8 @@ xfs_qm_dqpurge(
if (!error) {
error = xfs_bwrite(bp);
xfs_buf_relse(bp);
+ } else if (error == -EAGAIN) {
+ goto out_unlock;
}
xfs_dqflock(dqp);
}
@@ -174,6 +174,10 @@ xfs_qm_dqpurge(
xfs_qm_dqdestroy(dqp);
return 0;
+
+out_unlock:
+ xfs_dqunlock(dqp);
+ return error;
}
/*
Patches currently in stable-queue which might be from chandan.babu@xxxxxxxxxx are
queue-5.4/xfs-check-owner-of-dir3-blocks.patch
queue-5.4/xfs-throttle-commits-on-delayed-background-cil-push.patch
queue-5.4/xfs-factor-common-ail-item-deletion-code.patch
queue-5.4/xfs-remove-the-xfs_dq_logitem_t-typedef.patch
queue-5.4/xfs-fix-buffer-corruption-reporting-when-xfs_dir3_free_header_check-fails.patch
queue-5.4/xfs-xfs_buf_corruption_error-should-take-__this_address.patch
queue-5.4/xfs-open-code-insert-range-extent-split-helper.patch
queue-5.4/xfs-don-t-write-a-corrupt-unmount-record-to-force-summary-counter-recalc.patch
queue-5.4/xfs-check-owner-of-dir3-data-blocks.patch
queue-5.4/xfs-factor-out-quotaoff-intent-ail-removal-and-memory-free.patch
queue-5.4/xfs-trylock-underlying-buffer-on-dquot-flush.patch
queue-5.4/xfs-remove-the-xfs_disk_dquot_t-and-xfs_dquot_t.patch
queue-5.4/xfs-add-a-function-to-deal-with-corrupt-buffers-post-verifiers.patch
queue-5.4/xfs-fix-use-after-free-on-cil-context-on-shutdown.patch
queue-5.4/xfs-tail-updates-only-need-to-occur-when-lsn-changes.patch
queue-5.4/xfs-use-scnprintf-for-avoiding-potential-buffer-overflow.patch
queue-5.4/xfs-move-inode-flush-to-the-sync-workqueue.patch
queue-5.4/xfs-lower-cil-flush-limit-for-large-logs.patch
queue-5.4/xfs-rework-collapse-range-into-an-atomic-operation.patch
queue-5.4/xfs-remove-the-xfs_qoff_logitem_t-typedef.patch
queue-5.4/xfs-fix-unmount-hang-and-memory-leak-on-shutdown-during-quotaoff.patch
queue-5.4/xfs-preserve-default-grace-interval-during-quotacheck.patch
queue-5.4/xfs-replace-function-declaration-by-actual-definition.patch
queue-5.4/xfs-rework-insert-range-into-an-atomic-operation.patch
queue-5.4/xfs-factor-out-a-new-xfs_log_force_inode-helper.patch
queue-5.4/xfs-reflink-should-force-the-log-out-if-mounted-with-wsync.patch
