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/lustre_net.h>
  27
  28 static spinlock_t conn_lock;
  29 static struct list_head conn_list;
  30 static struct list_head conn_unused_list;
  31
  32 /* If UUID is NULL, c->c_remote_uuid must be all zeroes
  33  * If UUID is non-NULL, c->c_remote_uuid must match. */
  34 static int match_connection_uuid(struct ptlrpc_connection *c, obd_uuid_t uuid)
  35 {
  36         obd_uuid_t zero_uuid = {0};
  37
  38         if (uuid)
  39                 return memcmp(c->c_remote_uuid, uuid, sizeof(uuid));
  40
  41         return memcmp(c->c_remote_uuid, zero_uuid, sizeof(zero_uuid));
  42 }
  43
  44 struct ptlrpc_connection *ptlrpc_get_connection(struct lustre_peer *peer,
  45                                                 obd_uuid_t uuid)
  46 {
  47         struct list_head *tmp, *pos;
  48         struct ptlrpc_connection *c;
  49         ENTRY;
  50
  51         CDEBUG(D_INFO, "peer is %08x %08lx %08lx\n",
  52                peer->peer_nid, peer->peer_ni.nal_idx, peer->peer_ni.handle_idx);
  53
  54         spin_lock(&conn_lock);
  55         list_for_each(tmp, &conn_list) {
  56                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
  57                 if (memcmp(peer, &c->c_peer, sizeof(*peer)) == 0 &&
  58                     !match_connection_uuid(c, uuid)) {
  59                         ptlrpc_connection_addref(c);
  60                         GOTO(out, c);
  61                 }
  62         }
  63
  64         list_for_each_safe(tmp, pos, &conn_unused_list) {
  65                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
  66                 if (memcmp(peer, &c->c_peer, sizeof(*peer)) == 0 &&
  67                     !match_connection_uuid(c, uuid)) {
  68                         ptlrpc_connection_addref(c);
  69                         list_del(&c->c_link);
  70                         list_add(&c->c_link, &conn_list);
  71                         GOTO(out, c);
  72                 }
  73         }
  74
  75         /* FIXME: this should be a slab once we can validate slab addresses
  76          * without OOPSing */
  77         OBD_ALLOC(c, sizeof(*c));
  78         if (c == NULL)
  79                 GOTO(out, c);
  80
  81         c->c_level = LUSTRE_CONN_NEW;
  82         c->c_xid_in = 1;
  83         c->c_xid_out = 1;
  84         c->c_generation = 1;
  85         c->c_epoch = 1;
  86         c->c_bootcount = 0;
  87         if (uuid)
  88                 strcpy(c->c_remote_uuid, uuid);
  89         INIT_LIST_HEAD(&c->c_delayed_head);
  90         INIT_LIST_HEAD(&c->c_sending_head);
  91         INIT_LIST_HEAD(&c->c_dying_head);
  92         INIT_LIST_HEAD(&c->c_imports);
  93         INIT_LIST_HEAD(&c->c_exports);
  94         atomic_set(&c->c_refcount, 0);
  95         ptlrpc_connection_addref(c);
  96         spin_lock_init(&c->c_lock);
  97
  98         memcpy(&c->c_peer, peer, sizeof(c->c_peer));
  99         list_add(&c->c_link, &conn_list);
 100
 101         EXIT;
 102  out:
 103         spin_unlock(&conn_lock);
 104         return c;
 105 }
 106
 107 int ptlrpc_put_connection(struct ptlrpc_connection *c)
 108 {
 109         int rc = 0;
 110         ENTRY;
 111
 112         if (c == NULL) {
 113                 CERROR("NULL connection\n");
 114                 RETURN(0);
 115         }
 116
 117         CDEBUG(D_INFO, "connection=%p refcount %d\n",
 118                c, atomic_read(&c->c_refcount) - 1);
 119         if (atomic_dec_and_test(&c->c_refcount)) {
 120                 spin_lock(&conn_lock);
 121                 list_del(&c->c_link);
 122                 list_add(&c->c_link, &conn_unused_list);
 123                 spin_unlock(&conn_lock);
 124                 rc = 1;
 125         }
 126         if (atomic_read(&c->c_refcount) < 0)
 127                 CERROR("connection %p refcount %d!\n",
 128                        c, atomic_read(&c->c_refcount));
 129
 130         RETURN(rc);
 131 }
 132
 133 struct ptlrpc_connection *ptlrpc_connection_addref(struct ptlrpc_connection *c)
 134 {
 135         ENTRY;
 136         CDEBUG(D_INFO, "connection=%p refcount %d\n",
 137                c, atomic_read(&c->c_refcount) + 1);
 138         atomic_inc(&c->c_refcount);
 139         RETURN(c);
 140 }
 141
 142 void ptlrpc_init_connection(void)
 143 {
 144         INIT_LIST_HEAD(&conn_list);
 145         INIT_LIST_HEAD(&conn_unused_list);
 146         conn_lock = SPIN_LOCK_UNLOCKED;
 147 }
 148
 149 void ptlrpc_cleanup_connection(void)
 150 {
 151         struct list_head *tmp, *pos;
 152         struct ptlrpc_connection *c;
 153
 154         spin_lock(&conn_lock);
 155         list_for_each_safe(tmp, pos, &conn_unused_list) {
 156                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
 157                 list_del(&c->c_link);
 158                 OBD_FREE(c, sizeof(*c));
 159         }
 160         list_for_each_safe(tmp, pos, &conn_list) {
 161                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
 162                 CERROR("Connection %p has refcount %d at cleanup (nid=%lu)!\n",
 163                        c, atomic_read(&c->c_refcount),
 164                        (unsigned long)c->c_peer.peer_nid);
 165                 list_del(&c->c_link);
 166                 OBD_FREE(c, sizeof(*c));
 167         }
 168         spin_unlock(&conn_lock);
 169 }