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 #ifdef __KERNEL__
  25 #include <linux/obd_support.h>
  26 #include <linux/obd_class.h>
  27 #include <linux/lustre_net.h>
  28 #else
  29 #include <liblustre.h>
  30 #endif
  31
  32 static spinlock_t conn_lock;
  33 static struct list_head conn_list;
  34 static struct list_head conn_unused_list;
  35
  36 /* If UUID is NULL, c->c_remote_uuid must be all zeroes
  37  * If UUID is non-NULL, c->c_remote_uuid must match. */
  38 static int match_connection_uuid(struct ptlrpc_connection *c,
  39                                  struct obd_uuid *uuid)
  40 {
  41         struct obd_uuid zero_uuid;
  42         memset(&zero_uuid, 0, sizeof(zero_uuid));
  43
  44         if (uuid)
  45                 return memcmp(c->c_remote_uuid.uuid, uuid->uuid,
  46                               sizeof(uuid->uuid));
  47
  48         return memcmp(c->c_remote_uuid.uuid, &zero_uuid, sizeof(zero_uuid));
  49 }
  50
  51 struct ptlrpc_connection *ptlrpc_get_connection(struct ptlrpc_peer *peer,
  52                                                 struct obd_uuid *uuid)
  53 {
  54         struct list_head *tmp, *pos;
  55         struct ptlrpc_connection *c;
  56         ENTRY;
  57
  58         CDEBUG(D_INFO, "peer is "LPX64" on %s\n",
  59                peer->peer_nid, peer->peer_ni->pni_name);
  60
  61         spin_lock(&conn_lock);
  62         list_for_each(tmp, &conn_list) {
  63                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
  64                 if (peer->peer_nid == c->c_peer.peer_nid &&
  65                     peer->peer_ni == c->c_peer.peer_ni &&
  66                     !match_connection_uuid(c, uuid)) {
  67                         ptlrpc_connection_addref(c);
  68                         GOTO(out, c);
  69                 }
  70         }
  71
  72         list_for_each_safe(tmp, pos, &conn_unused_list) {
  73                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
  74                 if (peer->peer_nid == c->c_peer.peer_nid &&
  75                     peer->peer_ni == c->c_peer.peer_ni &&
  76                     !match_connection_uuid(c, uuid)) {
  77                         ptlrpc_connection_addref(c);
  78                         list_del(&c->c_link);
  79                         list_add(&c->c_link, &conn_list);
  80                         GOTO(out, c);
  81                 }
  82         }
  83
  84         /* FIXME: this should be a slab once we can validate slab addresses
  85          * without OOPSing */
  86         OBD_ALLOC(c, sizeof(*c));
  87         if (c == NULL)
  88                 GOTO(out, c);
  89
  90         c->c_generation = 1;
  91         c->c_epoch = 1;
  92         c->c_bootcount = 0;
  93         c->c_flags = 0;
  94         if (uuid->uuid)
  95                 obd_str2uuid(&c->c_remote_uuid, uuid->uuid);
  96         INIT_LIST_HEAD(&c->c_imports);
  97         INIT_LIST_HEAD(&c->c_exports);
  98         INIT_LIST_HEAD(&c->c_sb_chain);
  99         INIT_LIST_HEAD(&c->c_recovd_data.rd_managed_chain);
 100         INIT_LIST_HEAD(&c->c_delayed_head);
 101         atomic_set(&c->c_refcount, 0);
 102         memcpy(&c->c_peer, peer, sizeof(c->c_peer));
 103         spin_lock_init(&c->c_lock);
 104
 105         ptlrpc_connection_addref(c);
 106
 107         list_add(&c->c_link, &conn_list);
 108
 109         EXIT;
 110  out:
 111         spin_unlock(&conn_lock);
 112         return c;
 113 }
 114
 115 int ptlrpc_put_connection(struct ptlrpc_connection *c)
 116 {
 117         int rc = 0;
 118         ENTRY;
 119
 120         if (c == NULL) {
 121                 CERROR("NULL connection\n");
 122                 RETURN(0);
 123         }
 124
 125         CDEBUG (D_INFO, "connection=%p refcount %d to "LPX64" on %s\n",
 126                 c, atomic_read(&c->c_refcount), c->c_peer.peer_nid,
 127                 c->c_peer.peer_ni->pni_name);
 128
 129         if (atomic_dec_and_test(&c->c_refcount)) {
 130                 recovd_conn_unmanage(c);
 131                 spin_lock(&conn_lock);
 132                 list_del(&c->c_link);
 133                 list_add(&c->c_link, &conn_unused_list);
 134                 spin_unlock(&conn_lock);
 135                 rc = 1;
 136         }
 137         if (atomic_read(&c->c_refcount) < 0)
 138                 CERROR("connection %p refcount %d!\n",
 139                        c, atomic_read(&c->c_refcount));
 140
 141         RETURN(rc);
 142 }
 143
 144 struct ptlrpc_connection *ptlrpc_connection_addref(struct ptlrpc_connection *c)
 145 {
 146         ENTRY;
 147         atomic_inc(&c->c_refcount);
 148         CDEBUG (D_INFO, "connection=%p refcount %d to "LPX64" on %s\n",
 149                 c, atomic_read(&c->c_refcount), c->c_peer.peer_nid,
 150                 c->c_peer.peer_ni->pni_name);
 151         RETURN(c);
 152 }
 153
 154 void ptlrpc_init_connection(void)
 155 {
 156         INIT_LIST_HEAD(&conn_list);
 157         INIT_LIST_HEAD(&conn_unused_list);
 158         conn_lock = SPIN_LOCK_UNLOCKED;
 159 }
 160
 161 void ptlrpc_cleanup_connection(void)
 162 {
 163         struct list_head *tmp, *pos;
 164         struct ptlrpc_connection *c;
 165
 166         spin_lock(&conn_lock);
 167         list_for_each_safe(tmp, pos, &conn_unused_list) {
 168                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
 169                 list_del(&c->c_link);
 170                 OBD_FREE(c, sizeof(*c));
 171         }
 172         list_for_each_safe(tmp, pos, &conn_list) {
 173                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
 174                 CERROR("Connection %p/%s has refcount %d (nid="LPX64" on %s)\n",
 175                        c, c->c_remote_uuid.uuid, atomic_read(&c->c_refcount),
 176                        c->c_peer.peer_nid, c->c_peer.peer_ni->pni_name);
 177                 list_del(&c->c_link);
 178                 OBD_FREE(c, sizeof(*c));
 179         }
 180         spin_unlock(&conn_lock);
 181 }