[PATCH 1/4] nvme-fc: Add new routine nvme_fc_io_getuuid

[Himanshu Madhani]

> On May 10, 2022, at 1:00 PM, James Smart <jsmart2021 at gmail.com> wrote:
> 
> From: Muneendra <muneendra.kumar at broadcom.com>
> 
> Add nvme_fc_io_getuuid() to the nvme-fc transport.
> The routine is invoked by the fc LLDD on a per-io request basis.
> The routine translates from the fc-specific request structure to
> the bio and the cgroup structure in order to obtain the fc appid
> stored in the cgroup structure. If a value is not set or a bio
> is not found, a NULL appid (aka uuid) will be returned to the LLDD.
> 
> Signed-off-by: Muneendra <muneendra.kumar at broadcom.com>
> Signed-off-by: James Smart <jsmart2021 at gmail.com>
> ---
> drivers/nvme/host/fc.c         | 16 ++++++++++++++++
> include/linux/nvme-fc-driver.h | 14 ++++++++++++++
> 2 files changed, 30 insertions(+)
> 
> diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
> index 080f85f4105f..a484fe228cd5 100644
> --- a/drivers/nvme/host/fc.c
> +++ b/drivers/nvme/host/fc.c
> @@ -1899,6 +1899,22 @@ nvme_fc_ctrl_ioerr_work(struct work_struct *work)
> 	nvme_fc_error_recovery(ctrl, "transport detected io error");
> }
> 
> +/*
> + * nvme_fc_io_getuuid - Routine called to get the appid field
> + * associated with request by the lldd
> + * @req:IO request from nvme fc to driver
> + * Returns: UUID if there is an appid associated with VM or
> + * NULL if the user/libvirt has not set the appid to VM
> + */
> +char *nvme_fc_io_getuuid(struct nvmefc_fcp_req *req)
> +{
> +	struct nvme_fc_fcp_op *op = fcp_req_to_fcp_op(req);
> +	struct request *rq = op->rq;
> +
> +	return rq->bio ? blkcg_get_fc_appid(rq->bio) : NULL;
> +}
> +EXPORT_SYMBOL_GPL(nvme_fc_io_getuuid);
> +
> static void
> nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
> {
> diff --git a/include/linux/nvme-fc-driver.h b/include/linux/nvme-fc-driver.h
> index 5358a5facdee..fa092b9be2fd 100644
> --- a/include/linux/nvme-fc-driver.h
> +++ b/include/linux/nvme-fc-driver.h
> @@ -564,6 +564,15 @@ int nvme_fc_rcv_ls_req(struct nvme_fc_remote_port *remoteport,
> 			void *lsreqbuf, u32 lsreqbuf_len);
> 
> 
> +/*
> + * Routine called to get the appid field associated with request by the lldd
> + *
> + * If the return value is NULL : the user/libvirt has not set the appid to VM
> + * If the return value is non-zero: Returns the appid associated with VM
> + *
> + * @req: IO request from nvme fc to driver
> + */
> +char *nvme_fc_io_getuuid(struct nvmefc_fcp_req *req);
> 
> /*
>  * ***************  LLDD FC-NVME Target/Subsystem API ***************
> @@ -1048,5 +1057,10 @@ int nvmet_fc_rcv_fcp_req(struct nvmet_fc_target_port *tgtport,
> 
> void nvmet_fc_rcv_fcp_abort(struct nvmet_fc_target_port *tgtport,
> 			struct nvmefc_tgt_fcp_req *fcpreq);
> +/*
> + * add a define, visible to the compiler, that indicates support
> + * for feature. Allows for conditional compilation in LLDDs.
> + */
> +#define NVME_FC_FEAT_UUID	0x0001
> 
> #endif /* _NVME_FC_DRIVER_H */
> -- 
> 2.26.2
> 

Reviewed-by: Himanshu Madhani <himanshu.madhani at oracle.com>

--
Himanshu Madhani	Oracle Linux Engineering