Re: [PATCH 4/6] IB/srp: Fix indirect data buffer rkey endianness

[Bart Van Assche <bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>]

On 12/01/2015 10:37 AM, Sagi Grimberg wrote:
> On 01/12/2015 20:18, Bart Van Assche wrote:
>> Detected by sparse.
>>
>> Fixes: commit 330179f2fa93 ("IB/srp: Register the indirect data buffer
>> descriptor")
>> Signed-off-by: Bart Van Assche <bart.vanassche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>
>> Cc: stable <stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org> # v4.3+
>> Cc: Sagi Grimberg <sagig-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
>> Cc: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
>> Cc: Sebastian Parschauer <sebastian.riemer-EIkl63zCoXaH+58JC4qpiA@public.gmane.org>
>> ---
>>   drivers/infiniband/ulp/srp/ib_srp.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/infiniband/ulp/srp/ib_srp.c
>> b/drivers/infiniband/ulp/srp/ib_srp.c
>> index 72fac20..fac1423 100644
>> --- a/drivers/infiniband/ulp/srp/ib_srp.c
>> +++ b/drivers/infiniband/ulp/srp/ib_srp.c
>> @@ -1662,7 +1662,7 @@ static int srp_map_data(struct scsi_cmnd *scmnd,
>> struct srp_rdma_ch *ch,
>>               return ret;
>>           req->nmdesc++;
>>       } else {
>> -        idb_rkey = target->global_mr->rkey;
>> +        idb_rkey = cpu_to_be32(target->global_mr->rkey);
>>       }
>
> Wouldn't it make more sense to define idb_rkey to be u32 and change
> endianness when assigning it to the indirect desc?

Hello Sagi,

That's possible, but that would cause the endianness of the indirect 
data buffer rkey to be changed three times - a first time in 
srp_map_desc(), a second time in srp_map_idb() and a third time in 
srp_map_data(). Hence the choice to fix the IDB rkey via the above patch.

Bart.
--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html