xfs: Properly retry failed dquot items in case of error during buffer writeback

[ Upstream commit 373b0589dc8d58bc09c9a28d03611ae4fb216057 ]

Once the inode item writeback errors is already fixed, 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.

This patch aims to fix the same problem in dquot code, regarding failed buffers
being unable to be resubmitted once they are flush locked.

Tested with the recently test-case sent to fstests list by Hou Tao.

Orabug: 27609404
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: wen.gang.wang@oracle.com
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>

diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
index 34b9d71907435f2cd2e325ece0a61d47c9b11963..5517195c9f124a2d58f881d2c5c12aa5bcc953b2 100644 (file)
--- a/fs/xfs/xfs_dquot.c
+++ b/fs/xfs/xfs_dquot.c
@@ -901,14 +901,22 @@ 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 {
+                       /*
+                        * Clear the failed state since we are about to drop the
+                        * flush lock
+                        */
+                       if (lip->li_flags & XFS_LI_FAILED)
+                               xfs_clear_li_failed(lip);
                        spin_unlock(&ailp->xa_lock);
+               }
        }
 
        /*

diff --git a/fs/xfs/xfs_dquot_item.c b/fs/xfs/xfs_dquot_item.c
index 814cff94e78f6752bb9bf70d61697320c409f9e7..e7fae8fe18edbee81f0b7999d9c3a34aaea0ba15 100644 (file)
--- a/fs/xfs/xfs_dquot_item.c
+++ b/fs/xfs/xfs_dquot_item.c
@@ -137,6 +137,26 @@ 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)
+{
+       struct xfs_dquot        *dqp;
+
+       dqp = DQUOT_ITEM(lip)->qli_dquot;
+       ASSERT(!completion_done(&dqp->q_flush));
+       xfs_set_li_failed(lip, bp);
+}
+
 STATIC uint
 xfs_qm_dquot_logitem_push(
        struct xfs_log_item     *lip,
@@ -144,13 +164,28 @@ 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 +277,8 @@ 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
 };
 
 /*