Messages in this thread | | | Subject | Re: Changes to Linux/SCSI target mode infrastructure for v2.6.28 | From | "Nicholas A. Bellinger" <> | Date | Tue, 02 Dec 2008 00:30:46 -0800 |
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On Mon, 2008-12-01 at 22:40 -0800, Mike Anderson wrote: > Nicholas A. Bellinger <nab@linux-iscsi.org> wrote: > > On Tue, 2008-12-02 at 13:18 +0900, Tejun Heo wrote: > > > > > > >>> The other one is a BUG_ON in blk/blk-timeout.c:177 in blk_add_timeout() > > > >>> that happens after a few hundred MB of READ_10 traffic, which also > > > >>> appears to pass through elv_dequeue_request() at some point: > > > >>> > > > >>> http://linux-iscsi.org/builds/user/nab/2.6.28-rc6-oops-2.png > > > >>> http://linux-iscsi.org/builds/user/nab/2.6.28-rc6-oops-4.png > > > > > > Hmmm... this means blk_add_timer() is being called after the request > > > is already completed. > > or is it possible since elv_dequeue_request BUG_ON check of queuelist did > not trigger a request is on the queuelist with a timeout_list not empty. > > It would be interesting for a debug run to change the > "BUG_ON(!list_empty(&req->timeout_list))" in blk_add_timer to print out > the cmd_flags plus req->atomic_flags and also add a > "BUG_ON(!list_empty(&rq->timeout_list))" to elv_insert to ensure a request > is never added to the queuelist with a timeout_list not empty. >
Ok, so blk_dump_rq_flags() is now being called in block/blk-timeout.c:blk_add_timer() for the case BUG_ON(list_empty(&req->timeout_list)) case:
http://linux-iscsi.org/builds/user/nab/2.6.28-rc6-oops-6.png
Hmm, the outputted "sector " range is definately is bogus, as the only READ_10 that have been sent are at LBA offset 0 for 8 * 512 byte sectors for the partition table during Open/iSCSI LUN scanning.
--nab
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