Illumos #734: Use taskq_dispatch_ent() interface

[zfs.git] / module / zfs / zio.c

diff --git a/module/zfs/zio.c b/module/zfs/zio.c
index 6b03be6..c96442d 100644 (file)
--- a/module/zfs/zio.c
+++ b/module/zfs/zio.c
@@ -21,6 +21,7 @@
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2011 by Delphix. All rights reserved.
+ * Copyright (c) 2011 Nexenta Systems, Inc. All rights reserved.
  */
 
 #include <sys/zfs_context.h>
@@ -570,6 +571,8 @@ zio_create(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp,
                zio_add_child(pio, zio);
        }
 
+       taskq_init_ent(&zio->io_tqent);
+
        return (zio);
 }
 
@@ -1073,7 +1076,7 @@ zio_taskq_dispatch(zio_t *zio, enum zio_taskq_type q, boolean_t cutinline)
 {
        spa_t *spa = zio->io_spa;
        zio_type_t t = zio->io_type;
-       int flags = TQ_NOSLEEP | (cutinline ? TQ_FRONT : 0);
+       int flags = (cutinline ? TQ_FRONT : 0);
 
        /*
         * If we're a config writer or a probe, the normal issue and
@@ -1098,8 +1101,14 @@ zio_taskq_dispatch(zio_t *zio, enum zio_taskq_type q, boolean_t cutinline)
 
        ASSERT3U(q, <, ZIO_TASKQ_TYPES);
 
-       while (taskq_dispatch(spa->spa_zio_taskq[t][q],
-           (task_func_t *)zio_execute, zio, flags) == 0); /* do nothing */
+       /*
+        * NB: We are assuming that the zio can only be dispatched
+        * to a single taskq at a time.  It would be a grievous error
+        * to dispatch the zio to another taskq at the same time.
+        */
+       ASSERT(taskq_empty_ent(&zio->io_tqent));
+       taskq_dispatch_ent(spa->spa_zio_taskq[t][q],
+           (task_func_t *)zio_execute, zio, flags, &zio->io_tqent);
 }
 
 static boolean_t
@@ -2947,9 +2956,11 @@ zio_done(zio_t *zio)
                         * Reexecution is potentially a huge amount of work.
                         * Hand it off to the otherwise-unused claim taskq.
                         */
-                       (void) taskq_dispatch(
+                       ASSERT(taskq_empty_ent(&zio->io_tqent));
+                       (void) taskq_dispatch_ent(
                            zio->io_spa->spa_zio_taskq[ZIO_TYPE_CLAIM][ZIO_TASKQ_ISSUE],
-                           (task_func_t *)zio_reexecute, zio, TQ_SLEEP);
+                           (task_func_t *)zio_reexecute, zio, 0,
+                           &zio->io_tqent);
                }
                return (ZIO_PIPELINE_STOP);
        }