[XFS] Check for dquot flush errors

xfs_qm_dqflush() can fail, but the return is not checked anywhere. Hence
we never know if we've failed to flush a dquot to disk. Propagate the
error and warn to the syslog if a flush ever fails.

SGI-PV: 980084
SGI-Modid: xfs-linux-melb:xfs-kern:30787a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Niv Sardi <xaiki@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

fs/xfs/quota/xfs_dquot.c

@@ -1439,9 +1439,7 @@ xfs_qm_dqpurge(
 	uint		flags)
 {
 	xfs_dqhash_t	*thishash;
-	xfs_mount_t	*mp;
-
-	mp = dqp->q_mount;
+	xfs_mount_t	*mp = dqp->q_mount;
 
 	ASSERT(XFS_QM_IS_MPLIST_LOCKED(mp));
 	ASSERT(XFS_DQ_IS_HASH_LOCKED(dqp->q_hash));
@@ -1485,6 +1483,7 @@ xfs_qm_dqpurge(
 	 * we're unmounting, we do care, so we flush it and wait.
 	 */
 	if (XFS_DQ_IS_DIRTY(dqp)) {
+		int	error;
 		xfs_dqtrace_entry(dqp, "DQPURGE ->DQFLUSH: DQDIRTY");
 		/* dqflush unlocks dqflock */
 		/*
@@ -1495,7 +1494,10 @@ xfs_qm_dqpurge(
 		 * We don't care about getting disk errors here. We need
 		 * to purge this dquot anyway, so we go ahead regardless.
 		 */
-		(void) xfs_qm_dqflush(dqp, XFS_QMOPT_SYNC);
+		error = xfs_qm_dqflush(dqp, XFS_QMOPT_SYNC);
+		if (error)
+			xfs_fs_cmn_err(CE_WARN, mp,
+				"xfs_qm_dqpurge: dquot %p flush failed", dqp);
 		xfs_dqflock(dqp);
 	}
 	ASSERT(dqp->q_pincount == 0);

fs/xfs/quota/xfs_dquot_item.c

@@ -146,6 +146,7 @@ xfs_qm_dquot_logitem_push(
 	xfs_dq_logitem_t	*logitem)
 {
 	xfs_dquot_t	*dqp;
+	int		error;
 
 	dqp = logitem->qli_dquot;
 
@@ -161,7 +162,11 @@ xfs_qm_dquot_logitem_push(
 	 * lock without sleeping, then there must not have been
 	 * anyone in the process of flushing the dquot.
 	 */
-	xfs_qm_dqflush(dqp, XFS_B_DELWRI);
+	error = xfs_qm_dqflush(dqp, XFS_QMOPT_DELWRI);
+	if (error)
+		xfs_fs_cmn_err(CE_WARN, dqp->q_mount,
+			"xfs_qm_dquot_logitem_push: push error %d on dqp %p",
+			error, dqp);
 	xfs_dqunlock(dqp);
 }
 

fs/xfs/quota/xfs_qm.c

@@ -2094,12 +2094,17 @@ xfs_qm_shake_freelist(
 		 * dirty dquots.
 		 */
 		if (XFS_DQ_IS_DIRTY(dqp)) {
+			int	error;
 			xfs_dqtrace_entry(dqp, "DQSHAKE: DQDIRTY");
 			/*
 			 * We flush it delayed write, so don't bother
 			 * releasing the mplock.
 			 */
-			(void) xfs_qm_dqflush(dqp, XFS_QMOPT_DELWRI);
+			error = xfs_qm_dqflush(dqp, XFS_QMOPT_DELWRI);
+			if (error) {
+				xfs_fs_cmn_err(CE_WARN, dqp->q_mount,
+			"xfs_qm_dqflush_all: dquot %p flush failed", dqp);
+			}
 			xfs_dqunlock(dqp); /* dqflush unlocks dqflock */
 			dqp = dqp->dq_flnext;
 			continue;
@@ -2266,12 +2271,17 @@ xfs_qm_dqreclaim_one(void)
 		 * dirty dquots.
 		 */
 		if (XFS_DQ_IS_DIRTY(dqp)) {
+			int	error;
 			xfs_dqtrace_entry(dqp, "DQRECLAIM: DQDIRTY");
 			/*
 			 * We flush it delayed write, so don't bother
 			 * releasing the freelist lock.
 			 */
-			(void) xfs_qm_dqflush(dqp, XFS_QMOPT_DELWRI);
+			error = xfs_qm_dqflush(dqp, XFS_QMOPT_DELWRI);
+			if (error) {
+				xfs_fs_cmn_err(CE_WARN, dqp->q_mount,
+			"xfs_qm_dqreclaim: dquot %p flush failed", dqp);
+			}
 			xfs_dqunlock(dqp); /* dqflush unlocks dqflock */
 			continue;
 		}