[PATCH v2] scsi: RDMA/srpt: remove unnecessary assertion in srpt_queue_response

[PATCH v2] scsi: RDMA/srpt: remove unnecessary assertion in srpt_queue_response

[Aditya Pakki]

Currently, BUG_ON in srpt_queue_response, is used as an assertion for
empty rdma channel. However, if the channel is NULL, the call trace
on console is sufficient for diagnosis.

Signed-off-by: Aditya Pakki <pakki001@umn.edu>
---
v1: Avoid potential NULL pointer derefernce of ch. Current fix
suggested by Bart Van Assche
---
 drivers/infiniband/ulp/srpt/ib_srpt.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c
index 23c782e3d49a..98552749d71c 100644
--- a/drivers/infiniband/ulp/srpt/ib_srpt.c
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
@@ -2810,8 +2810,6 @@ static void srpt_queue_response(struct se_cmd *cmd)
 	int resp_len, ret, i;
 	u8 srp_tm_status;
 
-	BUG_ON(!ch);
-
 	state = ioctx->state;
 	switch (state) {
 	case SRPT_STATE_NEW:
-- 
2.20.1

Re: [PATCH v2] scsi: RDMA/srpt: remove unnecessary assertion in srpt_queue_response

[Bart Van Assche]

On 12/17/19 11:44 AM, Aditya Pakki wrote:
> Currently, BUG_ON in srpt_queue_response, is used as an assertion for
> empty rdma channel. However, if the channel is NULL, the call trace
> on console is sufficient for diagnosis.
> 
> Signed-off-by: Aditya Pakki <pakki001@umn.edu>
> ---
> v1: Avoid potential NULL pointer derefernce of ch. Current fix
> suggested by Bart Van Assche
> ---
>   drivers/infiniband/ulp/srpt/ib_srpt.c | 2 --
>   1 file changed, 2 deletions(-)
> 
> diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c
> index 23c782e3d49a..98552749d71c 100644
> --- a/drivers/infiniband/ulp/srpt/ib_srpt.c
> +++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
> @@ -2810,8 +2810,6 @@ static void srpt_queue_response(struct se_cmd *cmd)
>   	int resp_len, ret, i;
>   	u8 srp_tm_status;
>   
> -	BUG_ON(!ch);
> -
>   	state = ioctx->state;
>   	switch (state) {
>   	case SRPT_STATE_NEW:

I think the description of this patch should also mention that this 
patch removes a check of a pointer after it has already been 
dereferenced. Anyway:

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

Re: [PATCH v2] scsi: RDMA/srpt: remove unnecessary assertion in srpt_queue_response

[Jason Gunthorpe]

On Tue, Dec 17, 2019 at 01:44:37PM -0600, Aditya Pakki wrote:
> Currently, BUG_ON in srpt_queue_response, is used as an assertion for
> empty rdma channel. However, if the channel is NULL, the call trace
> on console is sufficient for diagnosis.
> 
> Signed-off-by: Aditya Pakki <pakki001@umn.edu>
> Reviewed-by: Bart Van Assche <bvanassche@acm.org>
> ---
> v1: Avoid potential NULL pointer derefernce of ch. Current fix
> suggested by Bart Van Assche
> ---
>  drivers/infiniband/ulp/srpt/ib_srpt.c | 2 --
>  1 file changed, 2 deletions(-)

Applied to for-next with the reworked commit message Bart suggested

Thanks,
Jason