[patch] brd: support barriers

[patch] brd: support barriers

[Nick Piggin]

Hi Jens,
Do you have a tree I can send this though? Is this the right way to
do what I want?

--

brd is always ordered (not that it matters, as it is defined not to
survive when the system goes down). So tell the block layer it is
ordered, which might be of help with testing filesystems.

Signed-off-by: Nick Piggin <npiggin@suse.de>
---
 drivers/block/brd.c |    1 +
 1 file changed, 1 insertion(+)

Index: linux-2.6/drivers/block/brd.c
===================================================================
--- linux-2.6.orig/drivers/block/brd.c
+++ linux-2.6/drivers/block/brd.c
@@ -436,6 +436,7 @@ static struct brd_device *brd_alloc(int
 	if (!brd->brd_queue)
 		goto out_free_dev;
 	blk_queue_make_request(brd->brd_queue, brd_make_request);
+	blk_queue_ordered(brd->brd_queue, QUEUE_ORDERED_TAG, NULL);
 	blk_queue_max_sectors(brd->brd_queue, 1024);
 	blk_queue_bounce_limit(brd->brd_queue, BLK_BOUNCE_ANY);
 

Re: [patch] brd: support barriers

[Jens Axboe]

On Wed, Apr 15 2009, Nick Piggin wrote:
> Hi Jens,
> Do you have a tree I can send this though? Is this the right way to
> do what I want?

It'll let the barriers through, so I think it does what you want :-)
I can put it in the block tree.

> 
> --
> 
> brd is always ordered (not that it matters, as it is defined not to
> survive when the system goes down). So tell the block layer it is
> ordered, which might be of help with testing filesystems.
> 
> Signed-off-by: Nick Piggin <npiggin@suse.de>
> ---
>  drivers/block/brd.c |    1 +
>  1 file changed, 1 insertion(+)
> 
> Index: linux-2.6/drivers/block/brd.c
> ===================================================================
> --- linux-2.6.orig/drivers/block/brd.c
> +++ linux-2.6/drivers/block/brd.c
> @@ -436,6 +436,7 @@ static struct brd_device *brd_alloc(int
>  	if (!brd->brd_queue)
>  		goto out_free_dev;
>  	blk_queue_make_request(brd->brd_queue, brd_make_request);
> +	blk_queue_ordered(brd->brd_queue, QUEUE_ORDERED_TAG, NULL);
>  	blk_queue_max_sectors(brd->brd_queue, 1024);
>  	blk_queue_bounce_limit(brd->brd_queue, BLK_BOUNCE_ANY);
>  

-- 
Jens Axboe