Commit c7a6d35e authored Apr 15, 2014 by Shaohua Li Committed by NeilBrown Apr 17, 2014

raid5: fix a race of stripe count check



I hit another BUG_ON with e240c183. In __get_priority_stripe(),
stripe count equals to 0 initially. Between atomic_inc and BUG_ON,
get_active_stripe() finds the stripe. So the stripe count isn't 1 any more.

V2: keeps the BUG_ON suggested by Neil.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: NeilBrown <neilb@suse.de>

parent e240c183

drivers/md/raid5.c

+1 −2

Original line number	Original line	Diff line number	Diff line
	@@ -4370,8 +4370,7 @@ static struct stripe_head __get_priority_stripe(struct r5conf conf, int group)
	sh->group = NULL;		sh->group = NULL;
	}		}
	list_del_init(&sh->lru);		list_del_init(&sh->lru);
	atomic_inc(&sh->count);		BUG_ON(atomic_inc_return(&sh->count) != 1);
	BUG_ON(atomic_read(&sh->count) != 1);
	return sh;		return sh;
	}		}