On 09/20/2011 09:32 AM, Jun'ichi Nomura wrote: > On 09/19/11 08:00, Ben Hutchings wrote: [ .. ] >> >> There have been reports of this in Debian going back to 2.6.39: >> >> http://bugs.debian.org/631187 >> http://bugs.debian.org/636263 >> http://bugs.debian.org/642043 >> >> Plus possibly related crashes in elv_put_request after CD-ROM removal: >> >> http://bugs.debian.org/633890 >> http://bugs.debian.org/634681 >> http://bugs.debian.org/636103 >> >> The former was also reported in Ubuntu since their 2.6.38-10: >> >> https://bugs.launchpad.net/debian/+source/linux-2.6/+bug/793796 >> >> The result of the discussion there was that it appeared to be a >> regression due to commit 86cbfb5607d4b81b1a993ff689bbd2addd5d3a9b >> ("[SCSI] put stricter guards on queue dead checks") which was also >> included in a stable update for 2.6.38. >> >> There was also a report on bugzilla.kernel.org, though no-one can see >> quite what that says now: >> >> https://bugzilla.kernel.org/show_bug.cgi?id=38842 >> >> I also reported most of the above to James Bottomley and linux-scsi >> nearly 2 months ago, to no response. > > I've reported a similar oops related to the above commit: > [BUG] Oops when SCSI device under multipath is removed > https://lkml.org/lkml/2011/8/10/11 > > Elevator being removed is the core of the problem. > And the essential issue seems 2 different models of queue/driver relation > implied by queue_lock. > > If reverting the commit is not an option, > until somebody comes up to fix the essential issue, > the patch below should close the regressions introduced by the commit. > Why do you have to do it that complicated? Couldn't we just state that any external lock is being disconnected from queue_lock after blk_cleanup_queue()? Then something like this should suffice here: diff --git a/block/blk-core.c b/block/blk-core.c index 90e1ffd..a4ac005 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -367,10 +367,8 @@ void blk_cleanup_queue(struct request_queue *q) queue_flag_set_unlocked(QUEUE_FLAG_DEAD, q); mutex_unlock(&q->sysfs_lock); - if (q->elevator) - elevator_exit(q->elevator); - - blk_throtl_exit(q); + if (q->queue_lock != q->__queue_lock) + q->queue_lock = q->__queue_lock; blk_put_queue(q); } diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 0ee17b5..a5a756b 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -477,6 +477,11 @@ static void blk_release_queue(struct kobject *kobj) blk_sync_queue(q); + if (q->elevator) + elevator_exit(q->elevator); + + blk_throtl_exit(q); + if (rl->rq_pool) mempool_destroy(rl->rq_pool); And yeah, I find it pretty annoying, too. Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@xxxxxxx +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Markus Rex, HRB 16746 (AG Nürnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
