On Mon, Feb 11 2008 at 17:43 +0200, Pete Wyckoff <pw@xxxxxxx> wrote:
> bharrosh@xxxxxxxxxxx wrote on Thu, 31 Jan 2008 22:29 +0200:
>> iscsi bidi support at the generic libiscsi level
>> - prepare the additional bidi_read rlength header.
>> - access the right scsi_in() and/or scsi_out() side of things.
>> also for resid.
>> - Handle BIDI underflow overflow from target
>>
>> Signed-off-by: Boaz Harrosh <bharrosh@xxxxxxxxxxx>
>
> I see you do this a bit differently than in your previous patch set.
> In particular, the residual handling in libiscsi.c. (I'm editing in
> a bit more context to the patch below.)
>
>> + if (scsi_bidi_cmnd(sc) &&
>> + (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
>> + ISCSI_FLAG_CMD_BIDI_OVERFLOW))) {
>> + int res_count = be32_to_cpu(rhdr->bi_residual_count);
>> +
>> + if (res_count > 0 &&
>> + (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
>> + res_count <= scsi_in(sc)->length))
>> + scsi_in(sc)->resid = res_count;
>> + else
>> + sc->result =
>> + (DID_BAD_TARGET << 16) | rhdr->cmd_status;
>> + }
>> +
>> if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
>> ISCSI_FLAG_CMD_OVERFLOW)) {
>> int res_count = be32_to_cpu(rhdr->residual_count);
>>
>> if (res_count > 0 &&
>> (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
>> res_count <= scsi_bufflen(sc)))
>> + /* write side for bidi or uni-io set_resid */
>> scsi_set_resid(sc, res_count);
>> else
>> sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
>> } else if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
>> ISCSI_FLAG_CMD_BIDI_OVERFLOW))
>> sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
>
> I haven't tested this, but, consider a bidi command that results in
> an overflow on the read part, and no overflow on the write part.
> E.g., the user supplied a data-in buffer that wasn't big enough to
> hold the returned data from the target, but the data-out buffer was
> just right.
>
> Then this code will set scsi_in(sc)->resid properly, informing the
> caller that there were extra bytes that were not transferred. But
> the "else" clause at the bottom will also set sc->result to be bad.
> I don't think we want this.
>
> Your earlier patch got rid of the second bidi_overflow handler and
> just did all the logic for both bidi and non-bidi cases in a single
> if clause. Seemed better.
>
> -- Pete
You are most probably right I will investigate what happened. It looks
like I went back to some old version right? or a merge fallout
Thanks for reviewing.
Please also test latest head-of-line code if possible + iscsi patches
+ last varlen I sent.
Is there any new patches I need for 2.6.24 or head-of-line for my
osd-dev tree?
Boaz
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