Messages in this thread Patch in this message | | | Date | Mon, 7 Dec 2009 13:15:47 -0500 | From | Vivek Goyal <> | Subject | [PATCH] cfq-iosched: Do not access cfqq after freeing it |
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Fix a crash during boot reported by Jeff Moyer. Fix the issue of accessing cfqq after freeing it.
Reported-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Index: linux-2.6-block/block/cfq-iosched.c =================================================================== --- linux-2.6-block.orig/block/cfq-iosched.c +++ linux-2.6-block/block/cfq-iosched.c @@ -2368,7 +2368,7 @@ static int cfq_dispatch_requests(struct static void cfq_put_queue(struct cfq_queue *cfqq) { struct cfq_data *cfqd = cfqq->cfqd; - struct cfq_group *cfqg; + struct cfq_group *cfqg, *orig_cfqg; BUG_ON(atomic_read(&cfqq->ref) <= 0); @@ -2379,6 +2379,7 @@ static void cfq_put_queue(struct cfq_que BUG_ON(rb_first(&cfqq->sort_list)); BUG_ON(cfqq->allocated[READ] + cfqq->allocated[WRITE]); cfqg = cfqq->cfqg; + orig_cfqg = cfqq->orig_cfqg; if (unlikely(cfqd->active_queue == cfqq)) { __cfq_slice_expired(cfqd, cfqq, 0); @@ -2388,8 +2389,8 @@ static void cfq_put_queue(struct cfq_que BUG_ON(cfq_cfqq_on_rr(cfqq)); kmem_cache_free(cfq_pool, cfqq); cfq_put_cfqg(cfqg); - if (cfqq->orig_cfqg) - cfq_put_cfqg(cfqq->orig_cfqg); + if (orig_cfqg) + cfq_put_cfqg(orig_cfqg); } /*
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