From 18b14b17c854d56b1f952bb6e18a1e0ff1e8b813 Mon Sep 17 00:00:00 2001
From: George Wilson <george.wilson@delphix.com>
Date: Fri, 2 Nov 2018 17:49:40 -0600
Subject: [PATCH] OpenZFS 9993 - zil writes can get delayed in zio pipeline

Authored by: George Wilson <george.wilson@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Brad Lewis <brad.lewis@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Tom Caputi <tcaputi@datto.com>
Reviewed by: George Melikov <mail@gmelikov.ru>
Approved by: Dan McDonald <danmcd@joyent.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/9993
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/2258ad0b
Closes #8185
---
 module/zfs/zio.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/module/zfs/zio.c b/module/zfs/zio.c
index 6f1aa640d..86788b33f 100644
--- a/module/zfs/zio.c
+++ b/module/zfs/zio.c
@@ -1738,7 +1738,8 @@ zio_taskq_dispatch(zio_t *zio, zio_taskq_type_t q, boolean_t cutinline)
 	 * If this is a high priority I/O, then use the high priority taskq if
 	 * available.
 	 */
-	if (zio->io_priority == ZIO_PRIORITY_NOW &&
+	if ((zio->io_priority == ZIO_PRIORITY_NOW ||
+	    zio->io_priority == ZIO_PRIORITY_SYNC_WRITE) &&
 	    spa->spa_zio_taskq[t][q + 1].stqs_count != 0)
 		q++;