This commit was manufactured by cvs2svn to create branch 'vserver'.
[linux-2.6.git] / drivers / infiniband / ulp / iser / iscsi_iser.c
diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.c b/drivers/infiniband/ulp/iser/iscsi_iser.c
new file mode 100644 (file)
index 0000000..1437d7e
--- /dev/null
@@ -0,0 +1,667 @@
+/*
+ * iSCSI Initiator over iSER Data-Path
+ *
+ * Copyright (C) 2004 Dmitry Yusupov
+ * Copyright (C) 2004 Alex Aizman
+ * Copyright (C) 2005 Mike Christie
+ * Copyright (c) 2005, 2006 Voltaire, Inc. All rights reserved.
+ * maintained by openib-general@openib.org
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *     - Redistributions of source code must retain the above
+ *       copyright notice, this list of conditions and the following
+ *       disclaimer.
+ *
+ *     - Redistributions in binary form must reproduce the above
+ *       copyright notice, this list of conditions and the following
+ *       disclaimer in the documentation and/or other materials
+ *       provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Credits:
+ *     Christoph Hellwig
+ *     FUJITA Tomonori
+ *     Arne Redlich
+ *     Zhenyu Wang
+ * Modified by:
+ *      Erez Zilber
+ *
+ *
+ * $Id: iscsi_iser.c 6965 2006-05-07 11:36:20Z ogerlitz $
+ */
+
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/hardirq.h>
+#include <linux/kfifo.h>
+#include <linux/blkdev.h>
+#include <linux/init.h>
+#include <linux/ioctl.h>
+#include <linux/cdev.h>
+#include <linux/in.h>
+#include <linux/net.h>
+#include <linux/scatterlist.h>
+#include <linux/delay.h>
+
+#include <net/sock.h>
+
+#include <asm/uaccess.h>
+
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_eh.h>
+#include <scsi/scsi_tcq.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_transport_iscsi.h>
+
+#include "iscsi_iser.h"
+
+static unsigned int iscsi_max_lun = 512;
+module_param_named(max_lun, iscsi_max_lun, uint, S_IRUGO);
+
+int iser_debug_level = 0;
+
+MODULE_DESCRIPTION("iSER (iSCSI Extensions for RDMA) Datamover "
+                  "v" DRV_VER " (" DRV_DATE ")");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Alex Nezhinsky, Dan Bar Dov, Or Gerlitz");
+
+module_param_named(debug_level, iser_debug_level, int, 0644);
+MODULE_PARM_DESC(debug_level, "Enable debug tracing if > 0 (default:disabled)");
+
+struct iser_global ig;
+
+void
+iscsi_iser_recv(struct iscsi_conn *conn,
+               struct iscsi_hdr *hdr, char *rx_data, int rx_data_len)
+{
+       int rc = 0;
+       uint32_t ret_itt;
+       int datalen;
+       int ahslen;
+
+       /* verify PDU length */
+       datalen = ntoh24(hdr->dlength);
+       if (datalen != rx_data_len) {
+               printk(KERN_ERR "iscsi_iser: datalen %d (hdr) != %d (IB) \n",
+                      datalen, rx_data_len);
+               rc = ISCSI_ERR_DATALEN;
+               goto error;
+       }
+
+       /* read AHS */
+       ahslen = hdr->hlength * 4;
+
+       /* verify itt (itt encoding: age+cid+itt) */
+       rc = iscsi_verify_itt(conn, hdr, &ret_itt);
+
+       if (!rc)
+               rc = iscsi_complete_pdu(conn, hdr, rx_data, rx_data_len);
+
+       if (rc && rc != ISCSI_ERR_NO_SCSI_CMD)
+               goto error;
+
+       return;
+error:
+       iscsi_conn_failure(conn, rc);
+}
+
+
+/**
+ * iscsi_iser_cmd_init - Initialize iSCSI SCSI_READ or SCSI_WRITE commands
+ *
+ **/
+static void
+iscsi_iser_cmd_init(struct iscsi_cmd_task *ctask)
+{
+       struct iscsi_iser_conn     *iser_conn  = ctask->conn->dd_data;
+       struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
+       struct scsi_cmnd  *sc = ctask->sc;
+
+       iser_ctask->command_sent = 0;
+       iser_ctask->iser_conn    = iser_conn;
+
+       if (sc->sc_data_direction == DMA_TO_DEVICE) {
+               BUG_ON(ctask->total_length == 0);
+               /* bytes to be sent via RDMA operations */
+               iser_ctask->rdma_data_count = ctask->total_length -
+                                        ctask->imm_count -
+                                        ctask->unsol_count;
+
+               debug_scsi("cmd [itt %x total %d imm %d unsol_data %d "
+                          "rdma_data %d]\n",
+                          ctask->itt, ctask->total_length, ctask->imm_count,
+                          ctask->unsol_count, iser_ctask->rdma_data_count);
+       } else
+               /* bytes to be sent via RDMA operations */
+               iser_ctask->rdma_data_count = ctask->total_length;
+
+       iser_ctask_rdma_init(iser_ctask);
+}
+
+/**
+ * iscsi_mtask_xmit - xmit management(immediate) task
+ * @conn: iscsi connection
+ * @mtask: task management task
+ *
+ * Notes:
+ *     The function can return -EAGAIN in which case caller must
+ *     call it again later, or recover. '0' return code means successful
+ *     xmit.
+ *
+ **/
+static int
+iscsi_iser_mtask_xmit(struct iscsi_conn *conn,
+                     struct iscsi_mgmt_task *mtask)
+{
+       int error = 0;
+
+       debug_scsi("mtask deq [cid %d itt 0x%x]\n", conn->id, mtask->itt);
+
+       error = iser_send_control(conn, mtask);
+
+       /* since iser xmits control with zero copy, mtasks can not be recycled
+        * right after sending them.
+        * The recycling scheme is based on whether a response is expected
+        * - if yes, the mtask is recycled at iscsi_complete_pdu
+        * - if no,  the mtask is recycled at iser_snd_completion
+        */
+       if (error && error != -EAGAIN)
+               iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
+
+       return error;
+}
+
+static int
+iscsi_iser_ctask_xmit_unsol_data(struct iscsi_conn *conn,
+                                struct iscsi_cmd_task *ctask)
+{
+       struct iscsi_data  hdr;
+       int error = 0;
+       struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
+
+       /* Send data-out PDUs while there's still unsolicited data to send */
+       while (ctask->unsol_count > 0) {
+               iscsi_prep_unsolicit_data_pdu(ctask, &hdr,
+                                             iser_ctask->rdma_data_count);
+
+               debug_scsi("Sending data-out: itt 0x%x, data count %d\n",
+                          hdr.itt, ctask->data_count);
+
+               /* the buffer description has been passed with the command */
+               /* Send the command */
+               error = iser_send_data_out(conn, ctask, &hdr);
+               if (error) {
+                       ctask->unsol_datasn--;
+                       goto iscsi_iser_ctask_xmit_unsol_data_exit;
+               }
+               ctask->unsol_count -= ctask->data_count;
+               debug_scsi("Need to send %d more as data-out PDUs\n",
+                          ctask->unsol_count);
+       }
+
+iscsi_iser_ctask_xmit_unsol_data_exit:
+       return error;
+}
+
+static int
+iscsi_iser_ctask_xmit(struct iscsi_conn *conn,
+                     struct iscsi_cmd_task *ctask)
+{
+       struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
+       int error = 0;
+
+       debug_scsi("ctask deq [cid %d itt 0x%x]\n",
+                  conn->id, ctask->itt);
+
+       /*
+        * serialize with TMF AbortTask
+        */
+       if (ctask->mtask)
+               return error;
+
+       /* Send the cmd PDU */
+       if (!iser_ctask->command_sent) {
+               error = iser_send_command(conn, ctask);
+               if (error)
+                       goto iscsi_iser_ctask_xmit_exit;
+               iser_ctask->command_sent = 1;
+       }
+
+       /* Send unsolicited data-out PDU(s) if necessary */
+       if (ctask->unsol_count)
+               error = iscsi_iser_ctask_xmit_unsol_data(conn, ctask);
+
+ iscsi_iser_ctask_xmit_exit:
+       if (error && error != -EAGAIN)
+               iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
+       return error;
+}
+
+static void
+iscsi_iser_cleanup_ctask(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
+{
+       struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
+
+       if (iser_ctask->status == ISER_TASK_STATUS_STARTED) {
+               iser_ctask->status = ISER_TASK_STATUS_COMPLETED;
+               iser_ctask_rdma_finalize(iser_ctask);
+       }
+}
+
+static struct iser_conn *
+iscsi_iser_ib_conn_lookup(__u64 ep_handle)
+{
+       struct iser_conn *ib_conn;
+       struct iser_conn *uib_conn = (struct iser_conn *)(unsigned long)ep_handle;
+
+       mutex_lock(&ig.connlist_mutex);
+       list_for_each_entry(ib_conn, &ig.connlist, conn_list) {
+               if (ib_conn == uib_conn) {
+                       mutex_unlock(&ig.connlist_mutex);
+                       return ib_conn;
+               }
+       }
+       mutex_unlock(&ig.connlist_mutex);
+       iser_err("no conn exists for eph %llx\n",(unsigned long long)ep_handle);
+       return NULL;
+}
+
+static struct iscsi_cls_conn *
+iscsi_iser_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
+{
+       struct iscsi_conn *conn;
+       struct iscsi_cls_conn *cls_conn;
+       struct iscsi_iser_conn *iser_conn;
+
+       cls_conn = iscsi_conn_setup(cls_session, conn_idx);
+       if (!cls_conn)
+               return NULL;
+       conn = cls_conn->dd_data;
+
+       /*
+        * due to issues with the login code re iser sematics
+        * this not set in iscsi_conn_setup - FIXME
+        */
+       conn->max_recv_dlength = 128;
+
+       iser_conn = kzalloc(sizeof(*iser_conn), GFP_KERNEL);
+       if (!iser_conn)
+               goto conn_alloc_fail;
+
+       /* currently this is the only field which need to be initiated */
+       rwlock_init(&iser_conn->lock);
+
+       conn->dd_data = iser_conn;
+       iser_conn->iscsi_conn = conn;
+
+       return cls_conn;
+
+conn_alloc_fail:
+       iscsi_conn_teardown(cls_conn);
+       return NULL;
+}
+
+static void
+iscsi_iser_conn_destroy(struct iscsi_cls_conn *cls_conn)
+{
+       struct iscsi_conn *conn = cls_conn->dd_data;
+       struct iscsi_iser_conn *iser_conn = conn->dd_data;
+
+       iscsi_conn_teardown(cls_conn);
+       kfree(iser_conn);
+}
+
+static int
+iscsi_iser_conn_bind(struct iscsi_cls_session *cls_session,
+                    struct iscsi_cls_conn *cls_conn, uint64_t transport_eph,
+                    int is_leading)
+{
+       struct iscsi_conn *conn = cls_conn->dd_data;
+       struct iscsi_iser_conn *iser_conn;
+       struct iser_conn *ib_conn;
+       int error;
+
+       error = iscsi_conn_bind(cls_session, cls_conn, is_leading);
+       if (error)
+               return error;
+
+       /* the transport ep handle comes from user space so it must be
+        * verified against the global ib connections list */
+       ib_conn = iscsi_iser_ib_conn_lookup(transport_eph);
+       if (!ib_conn) {
+               iser_err("can't bind eph %llx\n",
+                        (unsigned long long)transport_eph);
+               return -EINVAL;
+       }
+       /* binds the iSER connection retrieved from the previously
+        * connected ep_handle to the iSCSI layer connection. exchanges
+        * connection pointers */
+       iser_err("binding iscsi conn %p to iser_conn %p\n",conn,ib_conn);
+       iser_conn = conn->dd_data;
+       ib_conn->iser_conn = iser_conn;
+       iser_conn->ib_conn  = ib_conn;
+
+       conn->recv_lock = &iser_conn->lock;
+
+       return 0;
+}
+
+static int
+iscsi_iser_conn_start(struct iscsi_cls_conn *cls_conn)
+{
+       struct iscsi_conn *conn = cls_conn->dd_data;
+       int err;
+
+       err = iscsi_conn_start(cls_conn);
+       if (err)
+               return err;
+
+       return iser_conn_set_full_featured_mode(conn);
+}
+
+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)
+{
+       struct iscsi_cls_session *cls_session;
+       struct iscsi_session *session;
+       int i;
+       uint32_t hn;
+       struct iscsi_cmd_task  *ctask;
+       struct iscsi_mgmt_task *mtask;
+       struct iscsi_iser_cmd_task *iser_ctask;
+       struct iser_desc *desc;
+
+       cls_session = iscsi_session_setup(iscsit, scsit,
+                                         sizeof(struct iscsi_iser_cmd_task),
+                                         sizeof(struct iser_desc),
+                                         initial_cmdsn, &hn);
+       if (!cls_session)
+       return NULL;
+
+       *hostno = hn;
+       session = class_to_transport_session(cls_session);
+
+       /* libiscsi setup itts, data and pool so just set desc fields */
+       for (i = 0; i < session->cmds_max; i++) {
+               ctask      = session->cmds[i];
+               iser_ctask = ctask->dd_data;
+               ctask->hdr = (struct iscsi_cmd *)&iser_ctask->desc.iscsi_header;
+       }
+
+       for (i = 0; i < session->mgmtpool_max; i++) {
+               mtask      = session->mgmt_cmds[i];
+               desc       = mtask->dd_data;
+               mtask->hdr = &desc->iscsi_header;
+               desc->data = mtask->data;
+       }
+
+       return cls_session;
+}
+
+static int
+iscsi_iser_set_param(struct iscsi_cls_conn *cls_conn,
+                    enum iscsi_param param, char *buf, int buflen)
+{
+       int value;
+
+       switch (param) {
+       case ISCSI_PARAM_MAX_RECV_DLENGTH:
+               /* TBD */
+               break;
+       case ISCSI_PARAM_HDRDGST_EN:
+               sscanf(buf, "%d", &value);
+               if (value) {
+                       printk(KERN_ERR "DataDigest wasn't negotiated to None");
+                       return -EPROTO;
+               }
+               break;
+       case ISCSI_PARAM_DATADGST_EN:
+               sscanf(buf, "%d", &value);
+               if (value) {
+                       printk(KERN_ERR "DataDigest wasn't negotiated to None");
+                       return -EPROTO;
+               }
+               break;
+       case ISCSI_PARAM_IFMARKER_EN:
+               sscanf(buf, "%d", &value);
+               if (value) {
+                       printk(KERN_ERR "IFMarker wasn't negotiated to No");
+                       return -EPROTO;
+               }
+               break;
+       case ISCSI_PARAM_OFMARKER_EN:
+               sscanf(buf, "%d", &value);
+               if (value) {
+                       printk(KERN_ERR "OFMarker wasn't negotiated to No");
+                       return -EPROTO;
+               }
+               break;
+       default:
+               return iscsi_set_param(cls_conn, param, buf, buflen);
+       }
+
+       return 0;
+}
+
+static void
+iscsi_iser_conn_get_stats(struct iscsi_cls_conn *cls_conn, struct iscsi_stats *stats)
+{
+       struct iscsi_conn *conn = cls_conn->dd_data;
+
+       stats->txdata_octets = conn->txdata_octets;
+       stats->rxdata_octets = conn->rxdata_octets;
+       stats->scsicmd_pdus = conn->scsicmd_pdus_cnt;
+       stats->dataout_pdus = conn->dataout_pdus_cnt;
+       stats->scsirsp_pdus = conn->scsirsp_pdus_cnt;
+       stats->datain_pdus = conn->datain_pdus_cnt; /* always 0 */
+       stats->r2t_pdus = conn->r2t_pdus_cnt; /* always 0 */
+       stats->tmfcmd_pdus = conn->tmfcmd_pdus_cnt;
+       stats->tmfrsp_pdus = conn->tmfrsp_pdus_cnt;
+       stats->custom_length = 3;
+       strcpy(stats->custom[0].desc, "qp_tx_queue_full");
+       stats->custom[0].value = 0; /* TB iser_conn->qp_tx_queue_full; */
+       strcpy(stats->custom[1].desc, "fmr_map_not_avail");
+       stats->custom[1].value = 0; /* TB iser_conn->fmr_map_not_avail */;
+       strcpy(stats->custom[2].desc, "eh_abort_cnt");
+       stats->custom[2].value = conn->eh_abort_cnt;
+}
+
+static int
+iscsi_iser_ep_connect(struct sockaddr *dst_addr, int non_blocking,
+                     __u64 *ep_handle)
+{
+       int err;
+       struct iser_conn *ib_conn;
+
+       err = iser_conn_init(&ib_conn);
+       if (err)
+               goto out;
+
+       err = iser_connect(ib_conn, NULL, (struct sockaddr_in *)dst_addr, non_blocking);
+       if (!err)
+               *ep_handle = (__u64)(unsigned long)ib_conn;
+
+out:
+       return err;
+}
+
+static int
+iscsi_iser_ep_poll(__u64 ep_handle, int timeout_ms)
+{
+       struct iser_conn *ib_conn = iscsi_iser_ib_conn_lookup(ep_handle);
+       int rc;
+
+       if (!ib_conn)
+               return -EINVAL;
+
+       rc = wait_event_interruptible_timeout(ib_conn->wait,
+                            ib_conn->state == ISER_CONN_UP,
+                            msecs_to_jiffies(timeout_ms));
+
+       /* if conn establishment failed, return error code to iscsi */
+       if (!rc &&
+           (ib_conn->state == ISER_CONN_TERMINATING ||
+            ib_conn->state == ISER_CONN_DOWN))
+               rc = -1;
+
+       iser_err("ib conn %p rc = %d\n", ib_conn, rc);
+
+       if (rc > 0)
+               return 1; /* success, this is the equivalent of POLLOUT */
+       else if (!rc)
+               return 0; /* timeout */
+       else
+               return rc; /* signal */
+}
+
+static void
+iscsi_iser_ep_disconnect(__u64 ep_handle)
+{
+       struct iser_conn *ib_conn;
+
+       ib_conn = iscsi_iser_ib_conn_lookup(ep_handle);
+       if (!ib_conn)
+               return;
+
+       iser_err("ib conn %p state %d\n",ib_conn, ib_conn->state);
+       iser_conn_terminate(ib_conn);
+}
+
+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,
+       .sg_tablesize           = ISCSI_ISER_SG_TABLESIZE,
+       .cmd_per_lun            = ISCSI_MAX_CMD_PER_LUN,
+       .eh_abort_handler       = iscsi_eh_abort,
+       .eh_host_reset_handler  = iscsi_eh_host_reset,
+       .use_clustering         = DISABLE_CLUSTERING,
+       .proc_name              = "iscsi_iser",
+       .this_id                = -1,
+};
+
+static struct iscsi_transport iscsi_iser_transport = {
+       .owner                  = THIS_MODULE,
+       .name                   = "iser",
+       .caps                   = CAP_RECOVERY_L0 | CAP_MULTI_R2T,
+       .param_mask             = ISCSI_MAX_RECV_DLENGTH |
+                                 ISCSI_MAX_XMIT_DLENGTH |
+                                 ISCSI_HDRDGST_EN |
+                                 ISCSI_DATADGST_EN |
+                                 ISCSI_INITIAL_R2T_EN |
+                                 ISCSI_MAX_R2T |
+                                 ISCSI_IMM_DATA_EN |
+                                 ISCSI_FIRST_BURST |
+                                 ISCSI_MAX_BURST |
+                                 ISCSI_PDU_INORDER_EN |
+                                 ISCSI_DATASEQ_INORDER_EN |
+                                 ISCSI_EXP_STATSN |
+                                 ISCSI_PERSISTENT_PORT |
+                                 ISCSI_PERSISTENT_ADDRESS |
+                                 ISCSI_TARGET_NAME |
+                                 ISCSI_TPGT,
+       .host_template          = &iscsi_iser_sht,
+       .conndata_size          = sizeof(struct iscsi_conn),
+       .max_lun                = ISCSI_ISER_MAX_LUN,
+       .max_cmd_len            = ISCSI_ISER_MAX_CMD_LEN,
+       /* session management */
+       .create_session         = iscsi_iser_session_create,
+       .destroy_session        = iscsi_session_teardown,
+       /* connection management */
+       .create_conn            = iscsi_iser_conn_create,
+       .bind_conn              = iscsi_iser_conn_bind,
+       .destroy_conn           = iscsi_iser_conn_destroy,
+       .set_param              = iscsi_iser_set_param,
+       .get_conn_param         = iscsi_conn_get_param,
+       .get_session_param      = iscsi_session_get_param,
+       .start_conn             = iscsi_iser_conn_start,
+       .stop_conn              = iscsi_conn_stop,
+       /* IO */
+       .send_pdu               = iscsi_conn_send_pdu,
+       .get_stats              = iscsi_iser_conn_get_stats,
+       .init_cmd_task          = iscsi_iser_cmd_init,
+       .xmit_cmd_task          = iscsi_iser_ctask_xmit,
+       .xmit_mgmt_task         = iscsi_iser_mtask_xmit,
+       .cleanup_cmd_task       = iscsi_iser_cleanup_ctask,
+       /* recovery */
+       .session_recovery_timedout = iscsi_session_recovery_timedout,
+
+       .ep_connect             = iscsi_iser_ep_connect,
+       .ep_poll                = iscsi_iser_ep_poll,
+       .ep_disconnect          = iscsi_iser_ep_disconnect
+};
+
+static int __init iser_init(void)
+{
+       int err;
+
+       iser_dbg("Starting iSER datamover...\n");
+
+       if (iscsi_max_lun < 1) {
+               printk(KERN_ERR "Invalid max_lun value of %u\n", iscsi_max_lun);
+               return -EINVAL;
+       }
+
+       iscsi_iser_transport.max_lun = iscsi_max_lun;
+
+       memset(&ig, 0, sizeof(struct iser_global));
+
+       ig.desc_cache = kmem_cache_create("iser_descriptors",
+                                         sizeof (struct iser_desc),
+                                         0, SLAB_HWCACHE_ALIGN,
+                                         NULL, NULL);
+       if (ig.desc_cache == NULL)
+               return -ENOMEM;
+
+       /* device init is called only after the first addr resolution */
+       mutex_init(&ig.device_list_mutex);
+       INIT_LIST_HEAD(&ig.device_list);
+       mutex_init(&ig.connlist_mutex);
+       INIT_LIST_HEAD(&ig.connlist);
+
+       if (!iscsi_register_transport(&iscsi_iser_transport)) {
+               iser_err("iscsi_register_transport failed\n");
+               err = -EINVAL;
+               goto register_transport_failure;
+       }
+
+       return 0;
+
+register_transport_failure:
+       kmem_cache_destroy(ig.desc_cache);
+
+       return err;
+}
+
+static void __exit iser_exit(void)
+{
+       iser_dbg("Removing iSER datamover...\n");
+       iscsi_unregister_transport(&iscsi_iser_transport);
+       kmem_cache_destroy(ig.desc_cache);
+}
+
+module_init(iser_init);
+module_exit(iser_exit);