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         c->c_flags = 0;
  88         if (uuid)
  89                 strcpy(c->c_remote_uuid, uuid);
  90         INIT_LIST_HEAD(&c->c_delayed_head);
  91         INIT_LIST_HEAD(&c->c_sending_head);
  92         INIT_LIST_HEAD(&c->c_dying_head);
  93         INIT_LIST_HEAD(&c->c_imports);
  94         INIT_LIST_HEAD(&c->c_exports);
  95         INIT_LIST_HEAD(&c->c_sb_chain);
  96         atomic_set(&c->c_refcount, 0);
  97         ptlrpc_connection_addref(c);
  98         spin_lock_init(&c->c_lock);
  99
 100         memcpy(&c->c_peer, peer, sizeof(c->c_peer));
 101         list_add(&c->c_link, &conn_list);
 102
 103         EXIT;
 104  out:
 105         spin_unlock(&conn_lock);
 106         return c;
 107 }
 108
 109 int ptlrpc_put_connection(struct ptlrpc_connection *c)
 110 {
 111         int rc = 0;
 112         ENTRY;
 113
 114         if (c == NULL) {
 115                 CERROR("NULL connection\n");
 116                 RETURN(0);
 117         }
 118
 119         CDEBUG(D_INFO, "connection=%p refcount %d\n",
 120                c, atomic_read(&c->c_refcount) - 1);
 121         if (atomic_dec_and_test(&c->c_refcount)) {
 122                 spin_lock(&conn_lock);
 123                 list_del(&c->c_link);
 124                 list_add(&c->c_link, &conn_unused_list);
 125                 spin_unlock(&conn_lock);
 126                 rc = 1;
 127         }
 128         if (atomic_read(&c->c_refcount) < 0)
 129                 CERROR("connection %p refcount %d!\n",
 130                        c, atomic_read(&c->c_refcount));
 131
 132         RETURN(rc);
 133 }
 134
 135 struct ptlrpc_connection *ptlrpc_connection_addref(struct ptlrpc_connection *c)
 136 {
 137         ENTRY;
 138         CDEBUG(D_INFO, "connection=%p refcount %d\n",
 139                c, atomic_read(&c->c_refcount) + 1);
 140         atomic_inc(&c->c_refcount);
 141         RETURN(c);
 142 }
 143
 144 void ptlrpc_init_connection(void)
 145 {
 146         INIT_LIST_HEAD(&conn_list);
 147         INIT_LIST_HEAD(&conn_unused_list);
 148         conn_lock = SPIN_LOCK_UNLOCKED;
 149 }
 150
 151 void ptlrpc_cleanup_connection(void)
 152 {
 153         struct list_head *tmp, *pos;
 154         struct ptlrpc_connection *c;
 155
 156         spin_lock(&conn_lock);
 157         list_for_each_safe(tmp, pos, &conn_unused_list) {
 158                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
 159                 list_del(&c->c_link);
 160                 OBD_FREE(c, sizeof(*c));
 161         }
 162         list_for_each_safe(tmp, pos, &conn_list) {
 163                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
 164                 CERROR("Connection %p has refcount %d at cleanup (nid=%lu)!\n",
 165                        c, atomic_read(&c->c_refcount),
 166                        (unsigned long)c->c_peer.peer_nid);
 167                 list_del(&c->c_link);
 168                 OBD_FREE(c, sizeof(*c));
 169         }
 170         spin_unlock(&conn_lock);
 171 }