[PATCH 26/29] xfs: return -EAGAIN when nowait meets sync in transaction commit

[Hao Xu]

From: Hao Xu <howeyxu at tencent.com>

if the log transaction is a sync one, let's fail the nowait try and
return -EAGAIN directly since sync transaction means blocked by IO.

Signed-off-by: Hao Xu <howeyxu at tencent.com>
---
 fs/xfs/xfs_trans.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index 7988b4c7f36e..f1f84a3dd456 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -968,12 +968,24 @@ __xfs_trans_commit(
 	xfs_csn_t		commit_seq = 0;
 	int			error = 0;
 	int			sync = tp->t_flags & XFS_TRANS_SYNC;
+	bool			nowait = tp->t_flags & XFS_TRANS_NOWAIT;
+	bool			perm_log = tp->t_flags & XFS_TRANS_PERM_LOG_RES;
 
 	trace_xfs_trans_commit(tp, _RET_IP_);
 
+	if (nowait && sync) {
+		/*
+		 * Currently nowait is only from xfs_vn_update_time()
+		 * so perm_log is always false here, but let's make
+		 * code general.
+		 */
+		if (perm_log)
+			xfs_defer_cancel(tp);
+		goto out_unreserve;
+	}
 	error = xfs_trans_run_precommits(tp);
 	if (error) {
-		if (tp->t_flags & XFS_TRANS_PERM_LOG_RES)
+		if (perm_log)
 			xfs_defer_cancel(tp);
 		goto out_unreserve;
 	}
-- 
2.25.1