From: NeilBrown <neilb@suse.de>
To: Jianpeng Ma <majianpeng@gmail.com>
Cc: linux-raid <linux-raid@vger.kernel.org>
Subject: Re: [PATCH] raid5: fix possible oops in add_stripe_bio when enable pr_debug
Date: Thu, 20 Sep 2012 16:47:44 +1000 [thread overview]
Message-ID: <20120920164744.1aab090c@notabene.brown> (raw)
In-Reply-To: <2012092014334148441317@gmail.com>
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On Thu, 20 Sep 2012 14:34:00 +0800 "Jianpeng Ma" <majianpeng@gmail.com> wrote:
> In func add_stripe_bio:
> >> .....
> >> bip = &sh->dev[dd_idx].toread;
> >> ......
> >>spin_unlock_irq(&sh->stripe_lock);
>
> >> pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
> >> (unsigned long long)(*bip)->bi_sector,
> >> (unsigned long long)sh->sector, dd_idx);
> After spin_unlock_irq, this thread scheded and toread may become null.
> So it will be oops.
>
> Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
> ---
> drivers/md/raid5.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
> index adda94d..f172b1e 100644
> --- a/drivers/md/raid5.c
> +++ b/drivers/md/raid5.c
> @@ -2356,6 +2356,7 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, in
> struct bio **bip;
> struct r5conf *conf = sh->raid_conf;
> int firstwrite=0;
> + sector_t sector = bi->bi_sector;
>
> pr_debug("adding bi b#%llu to stripe s#%llu\n",
> (unsigned long long)bi->bi_sector,
> @@ -2406,7 +2407,7 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, in
> spin_unlock_irq(&sh->stripe_lock);
>
> pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
> - (unsigned long long)(*bip)->bi_sector,
> + (unsigned long long)sector,
> (unsigned long long)sh->sector, dd_idx);
>
> if (conf->mddev->bitmap && firstwrite) {
how about we just move the spin_unlock_irq after the pr_debug??
NeilBrown
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next prev parent reply other threads:[~2012-09-20 6:47 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-20 6:34 [PATCH] raid5: fix possible oops in add_stripe_bio when enable pr_debug Jianpeng Ma
2012-09-20 6:47 ` NeilBrown [this message]
2012-09-20 7:17 ` Jianpeng Ma
2012-09-25 6:45 ` NeilBrown
2012-09-25 6:50 ` Jianpeng Ma
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