On Tue, 9 Mar 2010 05:27:51 -0600
Sarang Radke <sarang.radke@xxxxxxxxxx> wrote:
> A panic is seen when an ELS BSG request is send for rport which is online, but goes offline before the request is processed.
>
> Here are the details of the issue and the fix.
>
> . The request handler routine fc_bsg_handler checks if the rport is not online and tries to end the request by calling blk_end_request.
> . blk_end_request does not finish the request because it calls bidi_end_bidi_request with bidi_bytes = 0.
> . After 60 sec. the timeout handler, fc_bsg_job_timeout is invoked for this unfinished command.
> . A panic is seen in fc_bsg_job_timeout because req->special is NULL.
> . req->special would have been set by function fc_req_to_bsgjob, if the rport was online.
> . The patch uses blk_end_request_all instead of blk_end_request which finishes the bidi request and timeout never happens.
>
>
> -Thanks,
> Sarang
>
> Signed-off-by: Lalit Chandivade <lalit.chandivade@xxxxxxxxxx>
> ---
> drivers/scsi/scsi_transport_fc.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c
> index 79660ee..304e710 100644
> --- a/drivers/scsi/scsi_transport_fc.c
> +++ b/drivers/scsi/scsi_transport_fc.c
> @@ -3852,7 +3852,7 @@ fc_bsg_request_handler(struct request_queue *q, struct Scsi_Host *shost,
> if (rport && (rport->port_state != FC_PORTSTATE_ONLINE)) {
> req->errors = -ENXIO;
> spin_unlock_irq(q->queue_lock);
> - blk_end_request(req, -ENXIO, blk_rq_bytes(req));
> + blk_end_request_all(req, -ENXIO);
> spin_lock_irq(q->queue_lock);
Yeah, looks fine to me. What we want to do here is just finishing the
request by force. But as James Smart pointed out, we need to replace
another blk_end_request too, I think.
--
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
