[PATCH 4.4 23/76] RDMA/srpt: Report the SCSI residual to the initiator

Greg Kroah-Hartman
2020-01-22T09:31:08Z

From: Bart Van Assche <bvanassche@acm.org>

commit e88982ad1bb12db699de96fbc07096359ef6176c upstream.

The code added by this patch is similar to the code that already exists in
ibmvscsis_determine_resid(). This patch has been tested by running the
following command:

strace sg_raw -r 1k /dev/sdb 12 00 00 00 60 00 -o inquiry.bin |&
grep resid=

Link: https://lore.kernel.org/r/20191105214632.183302-1-bvanassche@acm.org
Fixes: a42d985bd5b2 ("ib_srpt: Initial SRP Target merge for v3.3-rc1")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Honggang Li <honli@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/infiniband/ulp/srpt/ib_srpt.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)

--- a/drivers/infiniband/ulp/srpt/ib_srpt.c
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
@@ -1513,9 +1513,11 @@ static int srpt_build_cmd_rsp(struct srp
struct srpt_send_ioctx *ioctx, u64 tag,
int status)
{
+ struct se_cmd *cmd = &ioctx->cmd;
struct srp_rsp *srp_rsp;
const u8 *sense_data;
int sense_data_len, max_sense_len;
+ u32 resid = cmd->residual_count;

/*
* The lowest bit of all SAM-3 status codes is zero (see also
@@ -1537,6 +1539,28 @@ static int srpt_build_cmd_rsp(struct srp
srp_rsp->tag = tag;
srp_rsp->status = status;

+ if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
+ if (cmd->data_direction == DMA_TO_DEVICE) {
+ /* residual data from an underflow write */
+ srp_rsp->flags = SRP_RSP_FLAG_DOUNDER;
+ srp_rsp->data_out_res_cnt = cpu_to_be32(resid);
+ } else if (cmd->data_direction == DMA_FROM_DEVICE) {
+ /* residual data from an underflow read */
+ srp_rsp->flags = SRP_RSP_FLAG_DIUNDER;
+ srp_rsp->data_in_res_cnt = cpu_to_be32(resid);
+ }
+ } else if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
+ if (cmd->data_direction == DMA_TO_DEVICE) {
+ /* residual data from an overflow write */
+ srp_rsp->flags = SRP_RSP_FLAG_DOOVER;
+ srp_rsp->data_out_res_cnt = cpu_to_be32(resid);
+ } else if (cmd->data_direction == DMA_FROM_DEVICE) {
+ /* residual data from an overflow read */
+ srp_rsp->flags = SRP_RSP_FLAG_DIOVER;
+ srp_rsp->data_in_res_cnt = cpu_to_be32(resid);
+ }
+ }
+
if (sense_data_len) {
BUILD_BUG_ON(MIN_MAX_RSP_SIZE <= sizeof(*srp_rsp));
max_sense_len = ch->max_ti_iu_len - sizeof(*srp_rsp);