[SCSI] libiscsi: make can_queue configurable

This patch allows us to set can_queue and cmds_per_lun from userspace
when we create the session/host. From there we can set it on a per
target basis. The patch fully converts iscsi_tcp, but only hooks
up ib_iser for cmd_per_lun since it currently has a lots of preallocations
based on can_queue.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Cc: Roland Dreier <rdreier@cisco.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

3 files changed, 13 insertions, 6 deletions

diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.c b/drivers/infiniband/ulp/iser/iscsi_iser.c
index 9782190a9ee..bed583c426e 100644
--- a/drivers/infiniband/ulp/iser/iscsi_iser.c
+++ b/drivers/infiniband/ulp/iser/iscsi_iser.c
@@ -373,7 +373,8 @@ static struct iscsi_transport iscsi_iser_transport;
 static struct iscsi_cls_session *
 iscsi_iser_session_create(struct iscsi_transport *iscsit,
                          struct scsi_transport_template *scsit,
-                          uint32_t initial_cmdsn, uint32_t *hostno)
+                         uint16_t cmds_max, uint16_t qdepth,
+                         uint32_t initial_cmdsn, uint32_t *hostno)
 {
         struct iscsi_cls_session *cls_session;
         struct iscsi_session *session;
@@ -384,7 +385,13 @@ iscsi_iser_session_create(struct iscsi_transport *iscsit,
         struct iscsi_iser_cmd_task *iser_ctask;
         struct iser_desc *desc;
 
+        /*
+         * we do not support setting can_queue cmd_per_lun from userspace yet
+         * because we preallocate so many resources
+         */
         cls_session = iscsi_session_setup(iscsit, scsit,
+                                          ISCSI_DEF_XMIT_CMDS_MAX,
+                                          ISCSI_MAX_CMD_PER_LUN,
                                           sizeof(struct iscsi_iser_cmd_task),
                                           sizeof(struct iser_desc),
                                           initial_cmdsn, &hn);
@@ -543,7 +550,7 @@ iscsi_iser_ep_disconnect(__u64 ep_handle)
 static struct scsi_host_template iscsi_iser_sht = {
         .name                   = "iSCSI Initiator over iSER, v." DRV_VER,
         .queuecommand           = iscsi_queuecommand,
-        .can_queue              = ISCSI_XMIT_CMDS_MAX - 1,
+        .can_queue              = ISCSI_DEF_XMIT_CMDS_MAX - 1,
         .sg_tablesize           = ISCSI_ISER_SG_TABLESIZE,
         .max_sectors            = 1024,
         .cmd_per_lun            = ISCSI_MAX_CMD_PER_LUN,
diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.h b/drivers/infiniband/ulp/iser/iscsi_iser.h
index 8960196ffb0..e2353701e8b 100644
--- a/drivers/infiniband/ulp/iser/iscsi_iser.h
+++ b/drivers/infiniband/ulp/iser/iscsi_iser.h
@@ -98,7 +98,7 @@
 #define ISER_MAX_TX_MISC_PDUS           6 /* NOOP_OUT(2), TEXT(1),         *
                                            * SCSI_TMFUNC(2), LOGOUT(1) */
 
-#define ISER_QP_MAX_RECV_DTOS           (ISCSI_XMIT_CMDS_MAX + \
+#define ISER_QP_MAX_RECV_DTOS           (ISCSI_DEF_XMIT_CMDS_MAX + \
                                         ISER_MAX_RX_MISC_PDUS    +  \
                                         ISER_MAX_TX_MISC_PDUS)
 
@@ -110,7 +110,7 @@
 
 #define ISER_INFLIGHT_DATAOUTS          8
 
-#define ISER_QP_MAX_REQ_DTOS            (ISCSI_XMIT_CMDS_MAX *    \
+#define ISER_QP_MAX_REQ_DTOS            (ISCSI_DEF_XMIT_CMDS_MAX *    \
                                         (1 + ISER_INFLIGHT_DATAOUTS) + \
                                         ISER_MAX_TX_MISC_PDUS        + \
                                         ISER_MAX_RX_MISC_PDUS)
diff --git a/drivers/infiniband/ulp/iser/iser_verbs.c b/drivers/infiniband/ulp/iser/iser_verbs.c
index 3702e237555..2044de1164a 100644
--- a/drivers/infiniband/ulp/iser/iser_verbs.c
+++ b/drivers/infiniband/ulp/iser/iser_verbs.c
@@ -155,8 +155,8 @@ static int iser_create_ib_conn_res(struct iser_conn *ib_conn)
         params.max_pages_per_fmr = ISCSI_ISER_SG_TABLESIZE + 1;
         /* make the pool size twice the max number of SCSI commands *
          * the ML is expected to queue, watermark for unmap at 50%  */
-        params.pool_size         = ISCSI_XMIT_CMDS_MAX * 2;
-        params.dirty_watermark   = ISCSI_XMIT_CMDS_MAX;
+        params.pool_size         = ISCSI_DEF_XMIT_CMDS_MAX * 2;
+        params.dirty_watermark   = ISCSI_DEF_XMIT_CMDS_MAX;
         params.cache             = 0;
         params.flush_function    = NULL;
         params.access            = (IB_ACCESS_LOCAL_WRITE  |