[PATCH] MD RAID10: Fix oops when creating RAID10 arrays via dm-raid.c

[PATCH] MD RAID10: Fix oops when creating RAID10 arrays via dm-raid.c

[Jonathan Brassow]

Commit 2863b9eb didn't take into account the changes to add TRIM support to
RAID10 (commit 532a2a3fb).  That is, when using dm-raid.c to create the
RAID10 arrays, there is no mddev->gendisk or mddev->queue.  The code added
to support TRIM simply assumes that mddev->queue is available without
checking.  The result is an oops any time dm-raid.c attempts to create a
RAID10 device.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>

Index: linux-upstream/drivers/md/raid10.c
===================================================================
--- linux-upstream.orig/drivers/md/raid10.c
+++ linux-upstream/drivers/md/raid10.c
@@ -1783,7 +1783,7 @@ static int raid10_add_disk(struct mddev
 		clear_bit(Unmerged, &rdev->flags);
 	}
 	md_integrity_add_rdev(rdev, mddev);
-	if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
+	if (mddev->queue && blk_queue_discard(bdev_get_queue(rdev->bdev)))
 		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
 
 	print_conf(conf);
@@ -3613,11 +3613,14 @@ static int run(struct mddev *mddev)
 			discard_supported = true;
 	}
 
-	if (discard_supported)
-		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
-	else
-		queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
-
+	if (mddev->queue) {
+		if (discard_supported)
+			queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
+						mddev->queue);
+		else
+			queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD,
+						  mddev->queue);
+	}
 	/* need to check that every block has at least one working mirror */
 	if (!enough(conf, -1)) {
 		printk(KERN_ERR "md/raid10:%s: not enough operational mirrors.\n",

Re: [PATCH] MD RAID10: Fix oops when creating RAID10 arrays via dm-raid.c

[NeilBrown]

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On Thu, 25 Oct 2012 01:17:50 -0500 Jonathan Brassow <jbrassow@redhat.com>
wrote:

> Commit 2863b9eb didn't take into account the changes to add TRIM support to
> RAID10 (commit 532a2a3fb).  That is, when using dm-raid.c to create the
> RAID10 arrays, there is no mddev->gendisk or mddev->queue.  The code added
> to support TRIM simply assumes that mddev->queue is available without
> checking.  The result is an oops any time dm-raid.c attempts to create a
> RAID10 device.
> 
> Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
> 
> Index: linux-upstream/drivers/md/raid10.c
> ===================================================================
> --- linux-upstream.orig/drivers/md/raid10.c
> +++ linux-upstream/drivers/md/raid10.c
> @@ -1783,7 +1783,7 @@ static int raid10_add_disk(struct mddev
>  		clear_bit(Unmerged, &rdev->flags);
>  	}
>  	md_integrity_add_rdev(rdev, mddev);
> -	if (blk_queue_discard(bdev_get_queue(rdev->bdev)))
> +	if (mddev->queue && blk_queue_discard(bdev_get_queue(rdev->bdev)))
>  		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
>  
>  	print_conf(conf);
> @@ -3613,11 +3613,14 @@ static int run(struct mddev *mddev)
>  			discard_supported = true;
>  	}
>  
> -	if (discard_supported)
> -		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
> -	else
> -		queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue);
> -
> +	if (mddev->queue) {
> +		if (discard_supported)
> +			queue_flag_set_unlocked(QUEUE_FLAG_DISCARD,
> +						mddev->queue);
> +		else
> +			queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD,
> +						  mddev->queue);
> +	}
>  	/* need to check that every block has at least one working mirror */
>  	if (!enough(conf, -1)) {
>  		printk(KERN_ERR "md/raid10:%s: not enough operational mirrors.\n",
> 
> 
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Applied, thanks.

NeilBrown

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