X-Git-Url: https://git.camperquake.de/gitweb.cgi?a=blobdiff_plain;f=module%2Fzfs%2Fvdev_disk.c;h=5cb3fe279c9de21c01f0f1f4c5c6a35f1429fe3f;hb=e2448b0e62f73f8b9574d74c5b327707b67b703a;hp=aba3c4ab57ef284df3641bb3661312eef8cb2419;hpb=6839eed23e3c9d85cf0de767be32af0759e5bf2d;p=zfs.git

diff --git a/module/zfs/vdev_disk.c b/module/zfs/vdev_disk.c
index aba3c4a..5cb3fe2 100644
--- a/module/zfs/vdev_disk.c
+++ b/module/zfs/vdev_disk.c
@@ -118,25 +118,42 @@ vdev_disk_error(zio_t *zio)
  * automatically imported on module load so we must do this at device
  * open time from the kernel.
  */
+#define SET_SCHEDULER_CMD \
+	"exec 0</dev/null " \
+	"     1>/sys/block/%s/queue/scheduler " \
+	"     2>/dev/null; " \
+	"echo %s"
+
 static int
-vdev_elevator_switch(vdev_t *v, char *elevator, char *device)
+vdev_elevator_switch(vdev_t *v, char *elevator)
 {
-	char sh_path[] = "/bin/sh";
-	char sh_cmd[128];
-	char *argv[] = { sh_path, "-c", sh_cmd };
+	vdev_disk_t *vd = v->vdev_tsd;
+	struct block_device *bdev = vd->vd_bdev;
+	struct request_queue *q = bdev_get_queue(bdev);
+	char *device = bdev->bd_disk->disk_name;
+	char *argv[] = { "/bin/sh", "-c", NULL, NULL };
 	char *envp[] = { NULL };
 	int error;
 
-	if (!strncmp(elevator, "none", 4) && (strlen(elevator) == 4))
+	/* 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);
 
-	sprintf(sh_cmd, "%s \"%s\" >/sys/block/%s/queue/scheduler",
-	    "/bin/echo", elevator, device);
+	/* Leave existing scheduler when set to "none" */
+	if (!strncmp(elevator, "none", 4) && (strlen(elevator) == 4))
+		return (0);
 
-	error = call_usermodehelper(sh_path, argv, envp, 1);
+	argv[2] = kmem_asprintf(SET_SCHEDULER_CMD, device, elevator);
+	error = call_usermodehelper(argv[0], argv, envp, 1);
 	if (error)
 		printk("ZFS: Unable to set \"%s\" scheduler for %s (%s): %d\n",
-		    elevator, v->vdev_path, device, error);
+		       elevator, v->vdev_path, device, error);
+
+	strfree(argv[2]);
 
 	return (error);
 }
@@ -207,8 +224,7 @@ vdev_disk_open(vdev_t *v, uint64_t *psize, uint64_t *ashift)
 	*ashift = highbit(MAX(block_size, SPA_MINBLOCKSIZE)) - 1;
 
 	/* Try to set the io scheduler elevator algorithm */
-	(void) vdev_elevator_switch(v, zfs_vdev_scheduler,
-	    bdev->bd_disk->disk_name);
+	(void) vdev_elevator_switch(v, zfs_vdev_scheduler);
 
 	return 0;
 }