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iscsi_iser.c

/*
 * 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;

      iser_ctask->command_sent = 0;
      iser_ctask->iser_conn    = iser_conn;
      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 != -ENOBUFS)
            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;

      /* Send data-out PDUs while there's still unsolicited data to send */
      while (ctask->unsol_count > 0) {
            iscsi_prep_unsolicit_data_pdu(ctask, &hdr);
            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;

      if (ctask->sc->sc_data_direction == DMA_TO_DEVICE) {
            BUG_ON(scsi_bufflen(ctask->sc) == 0);

            debug_scsi("cmd [itt %x total %d imm %d unsol_data %d\n",
                     ctask->itt, scsi_bufflen(ctask->sc),
                     ctask->imm_count, ctask->unsol_count);
      }

      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 != -ENOBUFS)
            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);
      if (iser_conn->ib_conn)
            iser_conn->ib_conn->iser_conn = NULL;
      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 = iser_conn_set_full_featured_mode(conn);
      if (err)
            return err;

      return iscsi_conn_start(cls_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,
                   uint16_t cmds_max, uint16_t qdepth,
                   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;

      /*
       * 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);
      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 = {
      .module                 = THIS_MODULE,
      .name                   = "iSCSI Initiator over iSER, v." DRV_VER,
      .queuecommand           = iscsi_queuecommand,
      .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,
      .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 |
                          ISCSI_USERNAME | ISCSI_PASSWORD |
                          ISCSI_USERNAME_IN | ISCSI_PASSWORD_IN,
      .host_param_mask  = ISCSI_HOST_HWADDRESS |
                          ISCSI_HOST_NETDEV_NAME |
                          ISCSI_HOST_INITIATOR_NAME,
      .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,
      /* iscsi host params */
      .get_host_param         = iscsi_host_get_param,
      .set_host_param         = iscsi_host_set_param,
      /* 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);
      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);

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