IB/srp: Fix residual handling
From Documentation/scsi/scsi_mid_low_api.txt: "resid - an LLD should
set this signed integer to the requested transfer length (i.e.
'request_bufflen') less the number of bytes that are actually
transferred." This means that resid > 0 in case of an underrun and
also that resid < 0 in case of an overrun. Modify the SRP initiator
code such that it matches this requirement.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: David Dillow <dave@thedillows.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 7670008..7f5ee7f 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -1644,10 +1644,14 @@
SCSI_SENSE_BUFFERSIZE));
}
- if (rsp->flags & (SRP_RSP_FLAG_DOOVER | SRP_RSP_FLAG_DOUNDER))
- scsi_set_resid(scmnd, be32_to_cpu(rsp->data_out_res_cnt));
- else if (rsp->flags & (SRP_RSP_FLAG_DIOVER | SRP_RSP_FLAG_DIUNDER))
+ if (unlikely(rsp->flags & SRP_RSP_FLAG_DIUNDER))
scsi_set_resid(scmnd, be32_to_cpu(rsp->data_in_res_cnt));
+ else if (unlikely(rsp->flags & SRP_RSP_FLAG_DIOVER))
+ scsi_set_resid(scmnd, -be32_to_cpu(rsp->data_in_res_cnt));
+ else if (unlikely(rsp->flags & SRP_RSP_FLAG_DOUNDER))
+ scsi_set_resid(scmnd, be32_to_cpu(rsp->data_out_res_cnt));
+ else if (unlikely(rsp->flags & SRP_RSP_FLAG_DOOVER))
+ scsi_set_resid(scmnd, -be32_to_cpu(rsp->data_out_res_cnt));
srp_free_req(target, req, scmnd,
be32_to_cpu(rsp->req_lim_delta));