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 set this option.
Signed-off-by: Max Gurtovoy <maxg@xxxxxxxxxxxx>
Signed-off-by: Israel Rukshin <israelr@xxxxxxxxxxxx>
---
drivers/nvme/target/admin-cmd.c | 8 ++++++--
drivers/nvme/target/nvmet.h | 1 +
2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index d446813..c4ad0dd 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->set_mdts)
+ id->mdts = ctrl->ops->set_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 d2273c7..ff34d7a 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -292,6 +292,7 @@ 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 (*set_mdts)(struct nvmet_ctrl *ctrl);
};
#define NVMET_MAX_INLINE_BIOVEC 8
--
1.8.3.1
