lustre/ptlrpc/connection.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  *  Copyright (C) 2002 Cluster File Systems, Inc.
   5  *
   6  *   This file is part of Lustre, http://www.lustre.org.
   7  *
   8  *   Lustre is free software; you can redistribute it and/or
   9  *   modify it under the terms of version 2 of the GNU General Public
  10  *   License as published by the Free Software Foundation.
  11  *
  12  *   Lustre is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *   GNU General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU General Public License
  18  *   along with Lustre; if not, write to the Free Software
  19  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  *
  21  */
  22
  23 #define DEBUG_SUBSYSTEM S_RPC
  24
  25 #include <linux/obd_support.h>
  26 #include <linux/obd_class.h>
  27 #include <linux/lustre_net.h>
  28
  29 static spinlock_t conn_lock;
  30 static struct list_head conn_list;
  31 static struct list_head conn_unused_list;
  32
  33 /* If UUID is NULL, c->c_remote_uuid must be all zeroes
  34  * If UUID is non-NULL, c->c_remote_uuid must match. */
  35 static int match_connection_uuid(struct ptlrpc_connection *c, obd_uuid_t uuid)
  36 {
  37         obd_uuid_t zero_uuid = {0};
  38
  39         if (uuid)
  40                 return memcmp(c->c_remote_uuid, uuid, sizeof(uuid));
  41
  42         return memcmp(c->c_remote_uuid, zero_uuid, sizeof(zero_uuid));
  43 }
  44
  45 struct ptlrpc_connection *ptlrpc_get_connection(struct lustre_peer *peer,
  46                                                 obd_uuid_t uuid)
  47 {
  48         struct list_head *tmp, *pos;
  49         struct ptlrpc_connection *c;
  50         ENTRY;
  51
  52         CDEBUG(D_INFO, "peer is %08x %08lx %08lx\n",
  53                peer->peer_nid, peer->peer_ni.nal_idx, peer->peer_ni.handle_idx);
  54
  55         spin_lock(&conn_lock);
  56         list_for_each(tmp, &conn_list) {
  57                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
  58                 if (memcmp(peer, &c->c_peer, sizeof(*peer)) == 0 &&
  59                     !match_connection_uuid(c, uuid)) {
  60                         ptlrpc_connection_addref(c);
  61                         GOTO(out, c);
  62                 }
  63         }
  64
  65         list_for_each_safe(tmp, pos, &conn_unused_list) {
  66                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
  67                 if (memcmp(peer, &c->c_peer, sizeof(*peer)) == 0 &&
  68                     !match_connection_uuid(c, uuid)) {
  69                         ptlrpc_connection_addref(c);
  70                         list_del(&c->c_link);
  71                         list_add(&c->c_link, &conn_list);
  72                         GOTO(out, c);
  73                 }
  74         }
  75
  76         /* FIXME: this should be a slab once we can validate slab addresses
  77          * without OOPSing */
  78         OBD_ALLOC(c, sizeof(*c));
  79         if (c == NULL)
  80                 GOTO(out, c);
  81
  82         c->c_level = LUSTRE_CONN_NEW;
  83         c->c_xid_in = 1;
  84         c->c_xid_out = 1;
  85         c->c_generation = 1;
  86         c->c_epoch = 1;
  87         c->c_bootcount = 0;
  88         c->c_flags = 0;
  89         if (uuid)
  90                 strcpy(c->c_remote_uuid, uuid);
  91         INIT_LIST_HEAD(&c->c_delayed_head);
  92         INIT_LIST_HEAD(&c->c_sending_head);
  93         INIT_LIST_HEAD(&c->c_dying_head);
  94         INIT_LIST_HEAD(&c->c_imports);
  95         INIT_LIST_HEAD(&c->c_exports);
  96         INIT_LIST_HEAD(&c->c_sb_chain);
  97         INIT_LIST_HEAD(&c->c_recovd_data.rd_managed_chain);
  98         atomic_set(&c->c_refcount, 0);
  99         ptlrpc_connection_addref(c);
 100         spin_lock_init(&c->c_lock);
 101
 102         memcpy(&c->c_peer, peer, sizeof(c->c_peer));
 103         list_add(&c->c_link, &conn_list);
 104
 105         EXIT;
 106  out:
 107         spin_unlock(&conn_lock);
 108         return c;
 109 }
 110
 111 int ptlrpc_put_connection(struct ptlrpc_connection *c)
 112 {
 113         int rc = 0;
 114         ENTRY;
 115
 116         if (c == NULL) {
 117                 CERROR("NULL connection\n");
 118                 RETURN(0);
 119         }
 120
 121         CDEBUG(D_INFO, "connection=%p refcount %d\n",
 122                c, atomic_read(&c->c_refcount) - 1);
 123         if (atomic_dec_and_test(&c->c_refcount)) {
 124                 spin_lock(&conn_lock);
 125                 list_del(&c->c_link);
 126                 list_add(&c->c_link, &conn_unused_list);
 127                 spin_unlock(&conn_lock);
 128                 rc = 1;
 129         }
 130         if (atomic_read(&c->c_refcount) < 0)
 131                 CERROR("connection %p refcount %d!\n",
 132                        c, atomic_read(&c->c_refcount));
 133
 134         RETURN(rc);
 135 }
 136
 137 struct ptlrpc_connection *ptlrpc_connection_addref(struct ptlrpc_connection *c)
 138 {
 139         ENTRY;
 140         CDEBUG(D_INFO, "connection=%p refcount %d\n",
 141                c, atomic_read(&c->c_refcount) + 1);
 142         atomic_inc(&c->c_refcount);
 143         RETURN(c);
 144 }
 145
 146 void ptlrpc_init_connection(void)
 147 {
 148         INIT_LIST_HEAD(&conn_list);
 149         INIT_LIST_HEAD(&conn_unused_list);
 150         conn_lock = SPIN_LOCK_UNLOCKED;
 151 }
 152
 153 void ptlrpc_cleanup_connection(void)
 154 {
 155         struct list_head *tmp, *pos;
 156         struct ptlrpc_connection *c;
 157
 158         spin_lock(&conn_lock);
 159         list_for_each_safe(tmp, pos, &conn_unused_list) {
 160                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
 161                 list_del(&c->c_link);
 162                 OBD_FREE(c, sizeof(*c));
 163         }
 164         list_for_each_safe(tmp, pos, &conn_list) {
 165                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
 166                 CERROR("Connection %p has refcount %d at cleanup (nid=%lu)!\n",
 167                        c, atomic_read(&c->c_refcount),
 168                        (unsigned long)c->c_peer.peer_nid);
 169                 list_del(&c->c_link);
 170                 OBD_FREE(c, sizeof(*c));
 171         }
 172         spin_unlock(&conn_lock);
 173 }