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

[Jens Axboe <jaxboe@fusionio.com>]

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?

diff --git a/block/blk-core.c b/block/blk-core.c
index 59b5c00..121df87 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1197,6 +1197,7 @@ static bool attempt_plug_merge(struct task_struct *tsk, struct request_queue *q,
 	if (!plug)
 		goto out;
 
+	preempt_disable();
 	list_for_each_entry_reverse(rq, &plug->list, queuelist) {
 		int el_ret;
 
@@ -1214,6 +1215,7 @@ static bool attempt_plug_merge(struct task_struct *tsk, struct request_queue *q,
 				break;
 		}
 	}
+	preempt_enable();
 out:
 	return ret;
 }
@@ -1322,7 +1324,9 @@ get_rq:
 		 * Debug flag, kill later
 		 */
 		req->cmd_flags |= REQ_ON_PLUG;
+		preempt_disable();
 		list_add_tail(&req->queuelist, &plug->list);
+		preempt_enable();
 		drive_stat_acct(req, 1);
 	} else {
 		spin_lock_irq(q->queue_lock);

-- 
Jens Axboe