Re: [RFC]md: using GFP_NOIO to allocate bio for flush request

[Shaohua Li <shli@kernel.org>]

On Mon, Apr 16, 2012 at 01:32:06PM +0800, Shaohua Li wrote:
> 
> flush request is issued in transaction commit code path usually, so
> looks using
> GFP_KERNEL to allocate memory for flush request bio falls into the classic
> deadlock issue. dm already gets it right.
ping!


> Signed-off-by: Shaohua Li <shli@fusionio.com>
> ---
>  drivers/md/md.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> Index: linux/drivers/md/md.c
> ===================================================================
> --- linux.orig/drivers/md/md.c	2012-04-13 10:03:58.395497650 +0800
> +++ linux/drivers/md/md.c	2012-04-13 10:04:37.445497882 +0800
> @@ -450,7 +450,7 @@ static void submit_flushes(struct work_s
>  			atomic_inc(&rdev->nr_pending);
>  			atomic_inc(&rdev->nr_pending);
>  			rcu_read_unlock();
> -			bi = bio_alloc_mddev(GFP_KERNEL, 0, mddev);
> +			bi = bio_alloc_mddev(GFP_NOIO, 0, mddev);
>  			bi->bi_end_io = md_end_flush;
>  			bi->bi_private = rdev;
>  			bi->bi_bdev = rdev->bdev;