[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>

diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.c b/drivers/infiniband/ulp/iser/iscsi_iser.c
index 9782190..bed583c 100644 (file)
--- 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 8960196..e235370 100644 (file)
--- 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 3702e23..2044de1 100644 (file)
--- 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  |

diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 8edcfdd..eca4d61 100644 (file)
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -2114,6 +2114,7 @@ iscsi_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
 static struct iscsi_cls_session *
 iscsi_tcp_session_create(struct iscsi_transport *iscsit,
                         struct scsi_transport_template *scsit,
+                        uint16_t cmds_max, uint16_t qdepth,
                         uint32_t initial_cmdsn, uint32_t *hostno)
 {
        struct iscsi_cls_session *cls_session;
@@ -2121,7 +2122,7 @@ iscsi_tcp_session_create(struct iscsi_transport *iscsit,
        uint32_t hn;
        int cmd_i;
 
-       cls_session = iscsi_session_setup(iscsit, scsit,
+       cls_session = iscsi_session_setup(iscsit, scsit, cmds_max, qdepth,
                                         sizeof(struct iscsi_tcp_cmd_task),
                                         sizeof(struct iscsi_tcp_mgmt_task),
                                         initial_cmdsn, &hn);
@@ -2164,7 +2165,7 @@ static struct scsi_host_template iscsi_sht = {
        .name                   = "iSCSI Initiator over TCP/IP",
        .queuecommand           = iscsi_queuecommand,
        .change_queue_depth     = iscsi_change_queue_depth,
-       .can_queue              = ISCSI_XMIT_CMDS_MAX - 1,
+       .can_queue              = ISCSI_DEF_XMIT_CMDS_MAX - 1,
        .sg_tablesize           = ISCSI_SG_TABLESIZE,
        .max_sectors            = 0xFFFF,
        .cmd_per_lun            = ISCSI_DEF_CMD_PER_LUN,

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 938f527..1632866 100644 (file)
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -1330,6 +1330,10 @@ EXPORT_SYMBOL_GPL(iscsi_pool_free);
  * iscsi_session_setup - create iscsi cls session and host and session
  * @scsit: scsi transport template
  * @iscsit: iscsi transport template
+ * @cmds_max: scsi host can queue
+ * @qdepth: scsi host cmds per lun
+ * @cmd_task_size: LLD ctask private data size
+ * @mgmt_task_size: LLD mtask private data size
  * @initial_cmdsn: initial CmdSN
  * @hostno: host no allocated
  *
@@ -1339,6 +1343,7 @@ EXPORT_SYMBOL_GPL(iscsi_pool_free);
 struct iscsi_cls_session *
 iscsi_session_setup(struct iscsi_transport *iscsit,
                    struct scsi_transport_template *scsit,
+                   uint16_t cmds_max, uint16_t qdepth,
                    int cmd_task_size, int mgmt_task_size,
                    uint32_t initial_cmdsn, uint32_t *hostno)
 {
@@ -1347,11 +1352,32 @@ iscsi_session_setup(struct iscsi_transport *iscsit,
        struct iscsi_cls_session *cls_session;
        int cmd_i;
 
+       if (qdepth > ISCSI_MAX_CMD_PER_LUN || qdepth < 1) {
+               if (qdepth != 0)
+                       printk(KERN_ERR "iscsi: invalid queue depth of %d. "
+                             "Queue depth must be between 1 and %d.\n",
+                             qdepth, ISCSI_MAX_CMD_PER_LUN);
+               qdepth = ISCSI_DEF_CMD_PER_LUN;
+       }
+
+       if (cmds_max < 2 || (cmds_max & (cmds_max - 1)) ||
+           cmds_max >= ISCSI_MGMT_ITT_OFFSET) {
+               if (cmds_max != 0)
+                       printk(KERN_ERR "iscsi: invalid can_queue of %d. "
+                              "can_queue must be a power of 2 and between "
+                              "2 and %d - setting to %d.\n", cmds_max,
+                              ISCSI_MGMT_ITT_OFFSET, ISCSI_DEF_XMIT_CMDS_MAX);
+               cmds_max = ISCSI_DEF_XMIT_CMDS_MAX;
+       }
+
        shost = scsi_host_alloc(iscsit->host_template,
                                hostdata_privsize(sizeof(*session)));
        if (!shost)
                return NULL;
 
+       /* the iscsi layer takes one task for reserve */
+       shost->can_queue = cmds_max - 1;
+       shost->cmd_per_lun = qdepth;
        shost->max_id = 1;
        shost->max_channel = 0;
        shost->max_lun = iscsit->max_lun;
@@ -1365,7 +1391,7 @@ iscsi_session_setup(struct iscsi_transport *iscsit,
        session->host = shost;
        session->state = ISCSI_STATE_FREE;
        session->mgmtpool_max = ISCSI_MGMT_CMDS_MAX;
-       session->cmds_max = ISCSI_XMIT_CMDS_MAX;
+       session->cmds_max = cmds_max;
        session->cmdsn = initial_cmdsn;
        session->exp_cmdsn = initial_cmdsn + 1;
        session->max_cmdsn = initial_cmdsn + 1;

diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 341d4fb..859bd21 100644 (file)
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -814,6 +814,8 @@ iscsi_if_create_session(struct iscsi_internal *priv, struct iscsi_uevent *ev)
        uint32_t hostno;
 
        session = transport->create_session(transport, &priv->t,
+                                           ev->u.c_session.cmds_max,
+                                           ev->u.c_session.queue_depth,
                                            ev->u.c_session.initial_cmdsn,
                                            &hostno);
        if (!session)

diff --git a/include/scsi/iscsi_if.h b/include/scsi/iscsi_if.h
index 1a18196..a046a32 100644 (file)
--- a/include/scsi/iscsi_if.h
+++ b/include/scsi/iscsi_if.h
@@ -72,6 +72,8 @@ struct iscsi_uevent {
                /* messages u -> k */
                struct msg_create_session {
                        uint32_t        initial_cmdsn;
+                       uint16_t        cmds_max;
+                       uint16_t        queue_depth;
                } c_session;
                struct msg_destroy_session {
                        uint32_t        sid;

diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h
index 8d48cf8..2f303a3 100644 (file)
--- a/include/scsi/libiscsi.h
+++ b/include/scsi/libiscsi.h
@@ -48,9 +48,8 @@ struct iscsi_nopin;
 #define debug_scsi(fmt...)
 #endif
 
-#define ISCSI_XMIT_CMDS_MAX    128     /* must be power of 2 */
-#define ISCSI_MGMT_CMDS_MAX    32      /* must be power of 2 */
-#define ISCSI_CONN_MAX                 1
+#define ISCSI_DEF_XMIT_CMDS_MAX        128     /* must be power of 2 */
+#define ISCSI_MGMT_CMDS_MAX    16      /* must be power of 2 */
 
 #define ISCSI_MGMT_ITT_OFFSET  0xa00
 
@@ -268,7 +267,7 @@ extern int iscsi_host_get_param(struct Scsi_Host *shost,
  */
 extern struct iscsi_cls_session *
 iscsi_session_setup(struct iscsi_transport *, struct scsi_transport_template *,
-                   int, int, uint32_t, uint32_t *);
+                   uint16_t, uint16_t, int, int, uint32_t, uint32_t *);
 extern void iscsi_session_teardown(struct iscsi_cls_session *);
 extern struct iscsi_session *class_to_transport_session(struct iscsi_cls_session *);
 extern void iscsi_session_recovery_timedout(struct iscsi_cls_session *);

diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h
index abc4068..706c0cd 100644 (file)
--- a/include/scsi/scsi_transport_iscsi.h
+++ b/include/scsi/scsi_transport_iscsi.h
@@ -90,7 +90,8 @@ struct iscsi_transport {
        unsigned int max_conn;
        unsigned int max_cmd_len;
        struct iscsi_cls_session *(*create_session) (struct iscsi_transport *it,
-               struct scsi_transport_template *t, uint32_t sn, uint32_t *hn);
+               struct scsi_transport_template *t, uint16_t, uint16_t,
+               uint32_t sn, uint32_t *hn);
        void (*destroy_session) (struct iscsi_cls_session *session);
        struct iscsi_cls_conn *(*create_conn) (struct iscsi_cls_session *sess,
                                uint32_t cid);