Re: [PATCH v2 3/3] qla2xxx: Fix NVME cmd and LS cmd timeout race condition

[Bart Van Assche <bvanassche@xxxxxxx>]

On 6/18/19 11:10 AM, Himanshu Madhani wrote:
> diff --git a/drivers/scsi/qla2xxx/qla_nvme.h b/drivers/scsi/qla2xxx/qla_nvme.h
> index 2d088add7011..67bb4a2a3742 100644
> --- a/drivers/scsi/qla2xxx/qla_nvme.h
> +++ b/drivers/scsi/qla2xxx/qla_nvme.h
> @@ -34,6 +34,7 @@ struct nvme_private {
>   	struct work_struct ls_work;
>   	struct work_struct abort_work;
>   	int comp_status;
> +	spinlock_t cmd_lock;
>   };

Hi Himanshu and Quinn,

From the qla2xxx driver:

static struct nvme_fc_port_template qla_nvme_fc_transport = {
	[ ... ]
	.lsrqst_priv_sz = sizeof(struct nvme_private),
	.fcprqst_priv_sz = sizeof(struct nvme_private),
};
[ ... ]
struct nvme_private {
	struct srb	*sp;
	struct nvmefc_ls_req *fd;
	struct work_struct ls_work;
	struct work_struct abort_work;
	int comp_status;
};

Has it been considered to change "struct srb *sp" into "struct srb srb"? 
That would guarantee that the srb and nvme_private data structures have 
the same lifetime. As a result using the srb reference count would no 
longer be necessary for NVMe and no new locking would have to be 
introduced in the NVMe-FC completion paths.

I think a similar approach is possible for the SCSI-FC code.

Does this make sense to you?

Thanks,

Bart.