From: Max Gurtovoy Date: Sun, 8 Mar 2020 10:55:03 +0000 (+0200) Subject: nvmet: Add get_mdts op for controllers X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=02cb00e233ade7c050e0f476902e63847e78114e;p=linux.git nvmet: Add get_mdts op for controllers Some transports, such as RDMA, would like to set the Maximum Data Transfer Size (MDTS) according to device/port/ctrl characteristics. This will enable the transport to set the optimal MDTS according to controller needs and device capabilities. Add a new nvmet transport op that is called during ctrl identification. This will not effect transports that don't implement this option. The return value of the new op is according to the NVMe spec definition for MDTS. Reviewed-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Signed-off-by: Max Gurtovoy Signed-off-by: Israel Rukshin --- diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c index c0aa9c34c6999..b9ec489dc7486 100644 --- a/drivers/nvme/target/admin-cmd.c +++ b/drivers/nvme/target/admin-cmd.c @@ -369,8 +369,12 @@ static void nvmet_execute_identify_ctrl(struct nvmet_req *req) /* we support multiple ports, multiples hosts and ANA: */ id->cmic = (1 << 0) | (1 << 1) | (1 << 3); - /* no limit on data transfer sizes for now */ - id->mdts = 0; + /* Limit MDTS according to transport capability */ + if (ctrl->ops->get_mdts) + id->mdts = ctrl->ops->get_mdts(ctrl); + else + id->mdts = 0; + id->cntlid = cpu_to_le16(ctrl->cntlid); id->ver = cpu_to_le32(ctrl->subsys->ver); diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h index 42ba2ddd9e963..421dff3ea1433 100644 --- a/drivers/nvme/target/nvmet.h +++ b/drivers/nvme/target/nvmet.h @@ -289,6 +289,7 @@ struct nvmet_fabrics_ops { struct nvmet_port *port, char *traddr); u16 (*install_queue)(struct nvmet_sq *nvme_sq); void (*discovery_chg)(struct nvmet_port *port); + u8 (*get_mdts)(const struct nvmet_ctrl *ctrl); }; #define NVMET_MAX_INLINE_BIOVEC 8