From: Brian Behlendorf <behlendorf1@llnl.gov>
Date: Thu, 10 Mar 2011 21:34:17 +0000 (-0800)
Subject: Don't set I/O Scheduler for Partitions
X-Git-Tag: zfs-0.6.0-rc3~31
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=04516a45b27144cf42bec005ef2de6d505d236a5;p=zfs

Don't set I/O Scheduler for Partitions

ZFS should only change the i/o scheduler for a disk when it has
ownership of the whole disk.  This is basically the same logic as
adjusting the write cache behavior on a disk.  This change updates
the vdev disk code to skip partitions when setting the i/o scheduler.

Closes #152
---

diff --git a/module/zfs/vdev_disk.c b/module/zfs/vdev_disk.c
index 69bc53b4b..ec627a9c4 100644
--- a/module/zfs/vdev_disk.c
+++ b/module/zfs/vdev_disk.c
@@ -131,6 +131,10 @@ vdev_elevator_switch(vdev_t *v, char *elevator)
 	char *envp[] = { NULL };
 	int count = 0, error;
 
+	/* Skip devices which are not whole disks (partitions) */
+	if (!v->vdev_wholedisk)
+		return (0);
+
 	/* Skip devices without schedulers (loop, ram, dm, etc) */
 	if (!q->elevator || !blk_queue_stackable(q))
 		return (0);