[PATCH 5.10 217/406] scsi: RDMA/srp: Fix residual handling

Greg Kroah-Hartman
2023-09-17T19:33:14Z

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

[ Upstream commit 89e637c19b2441aabc8dbf22a8745b932fd6996e ]

Although the code for residual handling in the SRP initiator follows the
SCSI documentation, that documentation has never been correct. Because
scsi_finish_command() starts from the data buffer length and subtracts the
residual, scsi_set_resid() must not be called if a residual overflow
occurs. Hence remove the scsi_set_resid() calls from the SRP initiator if a
residual overflow occurrs.

Cc: Leon Romanovsky <leon@kernel.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Fixes: 9237f04e12cc ("scsi: core: Fix scsi_get/set_resid() interface")
Fixes: e714531a349f ("IB/srp: Fix residual handling")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230724200843.3376570-3-bvanassche@acm.org
Acked-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/infiniband/ulp/srp/ib_srp.c | 4 ----
1 file changed, 4 deletions(-)

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index adbd56af379ff..9b9b9557ae746 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -1990,12 +1990,8 @@ static void srp_process_rsp(struct srp_rdma_ch *ch, struct srp_rsp *rsp)

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(ch, req, scmnd,
be32_to_cpu(rsp->req_lim_delta));
--
2.40.1