Re: [GIT PULL] Core block IO bits for 2.6.39 - early Oops

Chris Mason
2011-03-25T14:19:24Z

Excerpts from Markus Trippelsdorf's message of 2011-03-25 10:14:13 -0400:
> On 2011.03.25 at 15:10 +0100, Jens Axboe wrote:
> > On 2011-03-25 14:09, Markus Trippelsdorf wrote:
> > > On 2011.03.25 at 13:44 +0100, Jens Axboe wrote:
> > >> On 2011-03-25 10:57, Markus Trippelsdorf wrote:
> > >>>
> > >>> Reverting it solves all problems here.
> > >>
> > >> Can you try this one?
> > >
> > > This one doesn't help; I still get the same BUG.
> > >
> > > BTW if you're having trouble reproducing this, here is the only non
> > > stock xfs option that I use on the affected partitions:
> > >
> > > noatime,logbsize=262144
> >
> > This?
>
> No.
>

I was able to reproduce it here. This is working for me:

diff --git a/block/blk-core.c b/block/blk-core.c
index 59b5c00..88f5f6a 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -271,7 +271,7 @@ EXPORT_SYMBOL(blk_start_queue);
**/
void blk_stop_queue(struct request_queue *q)
{
- cancel_delayed_work(&q->delay_work);
+ __cancel_delayed_work(&q->delay_work);
queue_flag_set(QUEUE_FLAG_STOPPED, q);
}
EXPORT_SYMBOL(blk_stop_queue);
@@ -1193,6 +1193,7 @@ static bool attempt_plug_merge(struct task_struct *tsk, struct request_queue *q,
struct request *rq;
bool ret = false;

+ preempt_disable();
plug = tsk->plug;
if (!plug)
goto out;
@@ -1215,6 +1216,7 @@ static bool attempt_plug_merge(struct task_struct *tsk, struct request_queue *q,
}
}
out:
+ preempt_enable();
return ret;
}

@@ -1309,6 +1311,7 @@ get_rq:
put_cpu();
}

+ preempt_disable();
plug = current->plug;
if (plug) {
if (!plug->should_sort && !list_empty(&plug->list)) {
@@ -1324,7 +1327,9 @@ get_rq:
req->cmd_flags |= REQ_ON_PLUG;
list_add_tail(&req->queuelist, &plug->list);
drive_stat_acct(req, 1);
+ preempt_enable();
} else {
+ preempt_enable();
spin_lock_irq(q->queue_lock);
add_acct_request(q, req, where);
__blk_run_queue(q, false);