MFp4 r186485, r186859:

Fix a race by defining two tasks in the zio structure
as we can still be returning from issue task when interrupt task is used.

Tested by:	pjd
Approved by:	pjd, delphij (mentor)
MFC after:	3 days

2 files changed, 28 insertions, 3 deletions

diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zio.h b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zio.h
index 4a4d286..049c122 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zio.h
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zio.h
@@ -340,7 +340,8 @@ struct zio {
 
 #ifdef _KERNEL
 	/* FreeBSD only. */
-	struct ostask	io_task;
+	struct ostask	io_task_issue;
+	struct ostask	io_task_interrupt;
 #endif
 };
 
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c
index b477563..32f15e9 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c
@@ -947,6 +947,18 @@ zio_taskq_dispatch(zio_t *zio, enum zio_taskq_type q)
 {
 	spa_t *spa = zio->io_spa;
 	zio_type_t t = zio->io_type;
+#ifdef _KERNEL
+	struct ostask *task;
+#endif
+
+	ASSERT(q == ZIO_TASKQ_ISSUE || q == ZIO_TASKQ_INTERRUPT);
+
+#ifdef _KERNEL
+	if (q == ZIO_TASKQ_ISSUE)
+		task = &zio->io_task_issue;
+	else /* if (q == ZIO_TASKQ_INTERRUPT) */
+		task = &zio->io_task_interrupt;
+#endif
 
 	/*
 	 * If we're a config writer or a probe, the normal issue and
@@ -970,8 +982,13 @@ zio_taskq_dispatch(zio_t *zio, enum zio_taskq_type q)
 		q++;
 
 	ASSERT3U(q, <, ZIO_TASKQ_TYPES);
+#ifdef _KERNEL
 	(void) taskq_dispatch_safe(spa->spa_zio_taskq[t][q],
-	    (task_func_t *)zio_execute, zio, &zio->io_task);
+	    (task_func_t *)zio_execute, zio, task);
+#else
+	(void) taskq_dispatch(spa->spa_zio_taskq[t][q],
+	    (task_func_t *)zio_execute, zio, TQ_SLEEP);
+#endif
 }
 
 static boolean_t
@@ -2300,9 +2317,16 @@ zio_done(zio_t *zio)
 			 * Reexecution is potentially a huge amount of work.
 			 * Hand it off to the otherwise-unused claim taskq.
 			 */
+#ifdef _KERNEL
 			(void) taskq_dispatch_safe(
 			    spa->spa_zio_taskq[ZIO_TYPE_CLAIM][ZIO_TASKQ_ISSUE],
-			    (task_func_t *)zio_reexecute, zio, &zio->io_task);
+			    (task_func_t *)zio_reexecute, zio,
+				&zio->io_task_issue);
+#else
+			(void) taskq_dispatch(
+			    spa->spa_zio_taskq[ZIO_TYPE_CLAIM][ZIO_TASKQ_ISSUE],
+				(task_func_t *)zio_reexecute, zio, TQ_SLEEP);
+#endif
 		}
 		return (ZIO_PIPELINE_STOP);
 	}