IB/iser: Accept session->cmds_max from user space
Use cmds_max passed from user space to be the number of PDUs to be
supported for the session instead of hard-coded ISCSI_DEF_XMIT_CMDS_MAX.
This allow controlling the max number of SCSI commands for the session.
Also don't ignore the qdepth passed from user space.
Derive from session->cmds_max the actual number of RX buffers and FMR
pool size to allocate during the connection bind phase.
Since the iser transport connection is established before the iscsi
session/connection are created and bound, we still use one hard-coded
quantity ISER_DEF_XMIT_CMDS_MAX to compute the maximum number of
work-requests to be supported by the RC QP used for the connection.
The above quantity is made to be a power of two between ISCSI_TOTAL_CMDS_MIN
(16) and ISER_DEF_XMIT_CMDS_MAX (512) inclusive.
Signed-off-by: Shlomo Pongratz <shlomop@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.c b/drivers/infiniband/ulp/iser/iscsi_iser.c
index 2e84ef8..705de7b 100644
--- a/drivers/infiniband/ulp/iser/iscsi_iser.c
+++ b/drivers/infiniband/ulp/iser/iscsi_iser.c
@@ -347,6 +347,7 @@
{
struct iscsi_conn *conn = cls_conn->dd_data;
struct iscsi_iser_conn *iser_conn;
+ struct iscsi_session *session;
struct iser_conn *ib_conn;
struct iscsi_endpoint *ep;
int error;
@@ -365,7 +366,8 @@
}
ib_conn = ep->dd_data;
- if (iser_alloc_rx_descriptors(ib_conn))
+ session = conn->session;
+ if (iser_alloc_rx_descriptors(ib_conn, session))
return -ENOMEM;
/* binds the iSER connection retrieved from the previously
@@ -419,12 +421,13 @@
struct iscsi_cls_session *cls_session;
struct iscsi_session *session;
struct Scsi_Host *shost;
- struct iser_conn *ib_conn;
+ struct iser_conn *ib_conn = NULL;
shost = iscsi_host_alloc(&iscsi_iser_sht, 0, 0);
if (!shost)
return NULL;
shost->transportt = iscsi_iser_scsi_transport;
+ shost->cmd_per_lun = qdepth;
shost->max_lun = iscsi_max_lun;
shost->max_id = 0;
shost->max_channel = 0;
@@ -441,12 +444,14 @@
ep ? ib_conn->device->ib_device->dma_device : NULL))
goto free_host;
- /*
- * we do not support setting can_queue cmd_per_lun from userspace yet
- * because we preallocate so many resources
- */
+ if (cmds_max > ISER_DEF_XMIT_CMDS_MAX) {
+ iser_info("cmds_max changed from %u to %u\n",
+ cmds_max, ISER_DEF_XMIT_CMDS_MAX);
+ cmds_max = ISER_DEF_XMIT_CMDS_MAX;
+ }
+
cls_session = iscsi_session_setup(&iscsi_iser_transport, shost,
- ISCSI_DEF_XMIT_CMDS_MAX, 0,
+ cmds_max, 0,
sizeof(struct iscsi_iser_task),
initial_cmdsn, 0);
if (!cls_session)