On 10/25/2016 07:51 PM, Chris Leech wrote:
> On Mon, Oct 24, 2016 at 04:37:59PM +0200, Hannes Reinecke wrote:
>> On 10/21/2016 11:10 PM, Chris Leech wrote:
>>> With the error message I added in "libfc: sanity check cpu number
>>> extracted from xid" I didn't account for the fact that fc_exch_find is
>>> called with FC_XID_UNKNOWN at the start of a new exchange if we are the
>>> responder.
>>>
>>> It doesn't come up with the initiator much, but that's basically every
>>> exchange for a target. By checking the xid for FC_XID_UNKNOWN first, we
>>> not only prevent the erroneous error message, but skip the unnecessary
>>> lookup attempt as well.
>>>
>>> Signed-off-by: Chris Leech <cleech@xxxxxxxxxx>
>>> ---
>>> drivers/scsi/libfc/fc_exch.c | 3 +++
>>> 1 file changed, 3 insertions(+)
>>>
>>> diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c
>>> index 16ca31a..42cc403 100644
>>> --- a/drivers/scsi/libfc/fc_exch.c
>>> +++ b/drivers/scsi/libfc/fc_exch.c
>>> @@ -910,6 +910,9 @@ static struct fc_exch *fc_exch_find(struct fc_exch_mgr *mp, u16 xid)
>>> struct fc_exch *ep = NULL;
>>> u16 cpu = xid & fc_cpu_mask;
>>>
>>> + if (xid == FC_XID_UNKNOWN)
>>> + return NULL;
>>> +
>>> if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) {
>>> printk_ratelimited(KERN_ERR
>>> "libfc: lookup request for XID = %d, "
>>>
>> Does that still apply with my libfc patchset?
>> I was under the impression I've fixed it already ...
>
> I believe so, although it might need refreshing to fix up the context
> change.
>
> It looks like you made a change specifically for REC, but in target mode
> with tcm_fc the first frame every new exchange comes in with RX_ID
> unknown until we assign one.
>
Indeed; looks you're right.
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@xxxxxxx +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)
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