LXR linux/net/rds/rdma

   1/*
   2 * Copyright (c) 2009 Oracle.  All rights reserved.
   3 *
   4 * This software is available to you under a choice of one of two
   5 * licenses.  You may choose to be licensed under the terms of the GNU
   6 * General Public License (GPL) Version 2, available from the file
   7 * COPYING in the main directory of this source tree, or the
   8 * OpenIB.org BSD license below:
   9 *
  10 *     Redistribution and use in source and binary forms, with or
  11 *     without modification, are permitted provided that the following
  12 *     conditions are met:
  13 *
  14 *      - Redistributions of source code must retain the above
  15 *        copyright notice, this list of conditions and the following
  16 *        disclaimer.
  17 *
  18 *      - Redistributions in binary form must reproduce the above
  19 *        copyright notice, this list of conditions and the following
  20 *        disclaimer in the documentation and/or other materials
  21 *        provided with the distribution.
  22 *
  23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30 * SOFTWARE.
  31 *
  32 */
  33#include <linux/module.h>
  34#include <rdma/rdma_cm.h>
  35
  36#include "rds_single_path.h"
  37#include "rdma_transport.h"
  38#include "ib.h"
  39
  40static struct rdma_cm_id *rds_rdma_listen_id;
  41
  42int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
  43                              struct rdma_cm_event *event)
  44{
  45        /* this can be null in the listening path */
  46        struct rds_connection *conn = cm_id->context;
  47        struct rds_transport *trans;
  48        int ret = 0;
  49
  50        rdsdebug("conn %p id %p handling event %u (%s)\n", conn, cm_id,
  51                 event->event, rdma_event_msg(event->event));
  52
  53        if (cm_id->device->node_type == RDMA_NODE_IB_CA)
  54                trans = &rds_ib_transport;
  55
  56        /* Prevent shutdown from tearing down the connection
  57         * while we're executing. */
  58        if (conn) {
  59                mutex_lock(&conn->c_cm_lock);
  60
  61                /* If the connection is being shut down, bail out
  62                 * right away. We return 0 so cm_id doesn't get
  63                 * destroyed prematurely */
  64                if (rds_conn_state(conn) == RDS_CONN_DISCONNECTING) {
  65                        /* Reject incoming connections while we're tearing
  66                         * down an existing one. */
  67                        if (event->event == RDMA_CM_EVENT_CONNECT_REQUEST)
  68                                ret = 1;
  69                        goto out;
  70                }
  71        }
  72
  73        switch (event->event) {
  74        case RDMA_CM_EVENT_CONNECT_REQUEST:
  75                ret = trans->cm_handle_connect(cm_id, event);
  76                break;
  77
  78        case RDMA_CM_EVENT_ADDR_RESOLVED:
  79                /* XXX do we need to clean up if this fails? */
  80                ret = rdma_resolve_route(cm_id,
  81                                         RDS_RDMA_RESOLVE_TIMEOUT_MS);
  82                break;
  83
  84        case RDMA_CM_EVENT_ROUTE_RESOLVED:
  85                /* Connection could have been dropped so make sure the
  86                 * cm_id is valid before proceeding
  87                 */
  88                if (conn) {
  89                        struct rds_ib_connection *ibic;
  90
  91                        ibic = conn->c_transport_data;
  92                        if (ibic && ibic->i_cm_id == cm_id)
  93                                ret = trans->cm_initiate_connect(cm_id);
  94                        else
  95                                rds_conn_drop(conn);
  96                }
  97                break;
  98
  99        case RDMA_CM_EVENT_ESTABLISHED:
 100                trans->cm_connect_complete(conn, event);
 101                break;
 102
 103        case RDMA_CM_EVENT_REJECTED:
 104                rdsdebug("Connection rejected: %s\n",
 105                         rdma_reject_msg(cm_id, event->status));
 106                /* FALLTHROUGH */
 107        case RDMA_CM_EVENT_ADDR_ERROR:
 108        case RDMA_CM_EVENT_ROUTE_ERROR:
 109        case RDMA_CM_EVENT_CONNECT_ERROR:
 110        case RDMA_CM_EVENT_UNREACHABLE:
 111        case RDMA_CM_EVENT_DEVICE_REMOVAL:
 112        case RDMA_CM_EVENT_ADDR_CHANGE:
 113                if (conn)
 114                        rds_conn_drop(conn);
 115                break;
 116
 117        case RDMA_CM_EVENT_DISCONNECTED:
 118                rdsdebug("DISCONNECT event - dropping connection "
 119                        "%pI4->%pI4\n", &conn->c_laddr,
 120                         &conn->c_faddr);
 121                rds_conn_drop(conn);
 122                break;
 123
 124        case RDMA_CM_EVENT_TIMEWAIT_EXIT:
 125                if (conn) {
 126                        pr_info("RDS: RDMA_CM_EVENT_TIMEWAIT_EXIT event: dropping connection %pI4->%pI4\n",
 127                                &conn->c_laddr, &conn->c_faddr);
 128                        rds_conn_drop(conn);
 129                }
 130                break;
 131
 132        default:
 133                /* things like device disconnect? */
 134                printk(KERN_ERR "RDS: unknown event %u (%s)!\n",
 135                       event->event, rdma_event_msg(event->event));
 136                break;
 137        }
 138
 139out:
 140        if (conn)
 141                mutex_unlock(&conn->c_cm_lock);
 142
 143        rdsdebug("id %p event %u (%s) handling ret %d\n", cm_id, event->event,
 144                 rdma_event_msg(event->event), ret);
 145
 146        return ret;
 147}
 148
 149static int rds_rdma_listen_init(void)
 150{
 151        struct sockaddr_in sin;
 152        struct rdma_cm_id *cm_id;
 153        int ret;
 154
 155        cm_id = rdma_create_id(&init_net, rds_rdma_cm_event_handler, NULL,
 156                               RDMA_PS_TCP, IB_QPT_RC);
 157        if (IS_ERR(cm_id)) {
 158                ret = PTR_ERR(cm_id);
 159                printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 160                       "rdma_create_id() returned %d\n", ret);
 161                return ret;
 162        }
 163
 164        sin.sin_family = AF_INET;
 165        sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
 166        sin.sin_port = (__force u16)htons(RDS_PORT);
 167
 168        /*
 169         * XXX I bet this binds the cm_id to a device.  If we want to support
 170         * fail-over we'll have to take this into consideration.
 171         */
 172        ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
 173        if (ret) {
 174                printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 175                       "rdma_bind_addr() returned %d\n", ret);
 176                goto out;
 177        }
 178
 179        ret = rdma_listen(cm_id, 128);
 180        if (ret) {
 181                printk(KERN_ERR "RDS/RDMA: failed to setup listener, "
 182                       "rdma_listen() returned %d\n", ret);
 183                goto out;
 184        }
 185
 186        rdsdebug("cm %p listening on port %u\n", cm_id, RDS_PORT);
 187
 188        rds_rdma_listen_id = cm_id;
 189        cm_id = NULL;
 190out:
 191        if (cm_id)
 192                rdma_destroy_id(cm_id);
 193        return ret;
 194}
 195
 196static void rds_rdma_listen_stop(void)
 197{
 198        if (rds_rdma_listen_id) {
 199                rdsdebug("cm %p\n", rds_rdma_listen_id);
 200                rdma_destroy_id(rds_rdma_listen_id);
 201                rds_rdma_listen_id = NULL;
 202        }
 203}
 204
 205static int rds_rdma_init(void)
 206{
 207        int ret;
 208
 209        ret = rds_ib_init();
 210        if (ret)
 211                goto out;
 212
 213        ret = rds_rdma_listen_init();
 214        if (ret)
 215                rds_ib_exit();
 216out:
 217        return ret;
 218}
 219module_init(rds_rdma_init);
 220
 221static void rds_rdma_exit(void)
 222{
 223        /* stop listening first to ensure no new connections are attempted */
 224        rds_rdma_listen_stop();
 225        rds_ib_exit();
 226}
 227module_exit(rds_rdma_exit);
 228
 229MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
 230MODULE_DESCRIPTION("RDS: IB transport");
 231MODULE_LICENSE("Dual BSD/GPL");
 232
 233