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Date: Fri, 18 Nov 2005 20:32:59 +0500
From: "Alexander E. Patrakov" <patrakov@ums.usu.ru>
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To: Alasdair G Kergon <agk@redhat.com>
Cc: linux-kernel@vger.kernel.org, jblunck@suse.de
Subject: Re: [PATCH] device-mapper snapshot: bio_list fix
References: <20051118145547.GK11878@agk.surrey.redhat.com>
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Alasdair G Kergon wrote:
> bio_list_merge() should do nothing if the second list is empty - not oops.
> 
> From: jblunck@suse.de
> Signed-Off-By: Alasdair G Kergon <agk@redhat.com>
> 
> Index: linux-2.6.14/drivers/md/dm-bio-list.h
> ===================================================================
> --- linux-2.6.14.orig/drivers/md/dm-bio-list.h	2005-10-28 01:02:08.000000000 +0100
> +++ linux-2.6.14/drivers/md/dm-bio-list.h	2005-11-15 15:59:20.000000000 +0000
> @@ -33,6 +33,9 @@ static inline void bio_list_add(struct b
>  
>  static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
>  {
> +	if (!bl2->head)
> +		return;
> +
>  	if (bl->tail)
>  		bl->tail->bi_next = bl2->head;
>  	else

Could you please tell how to reproduce this oops using e.g. loop 
devices? This patch looks relevant to my Live CD (although no oops has 
been reported yet).

-- 
Alexander E. Patrakov