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/lustre_net.h>
  26
  27 static spinlock_t conn_lock;
  28 static struct list_head conn_list;
  29 static struct list_head conn_unused_list;
  30
  31 struct ptlrpc_connection *ptlrpc_get_connection(struct lustre_peer *peer)
  32 {
  33         struct list_head *tmp, *pos;
  34         struct ptlrpc_connection *c;
  35         ENTRY;
  36
  37         spin_lock(&conn_lock);
  38         list_for_each(tmp, &conn_list) {
  39                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
  40                 if (memcmp(peer, &c->c_peer, sizeof(*peer)) == 0) {
  41                         ptlrpc_connection_addref(c);
  42                         GOTO(out, c);
  43                 }
  44         }
  45
  46         list_for_each_safe(tmp, pos, &conn_unused_list) {
  47                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
  48                 if (memcmp(peer, &c->c_peer, sizeof(*peer)) == 0) {
  49                         ptlrpc_connection_addref(c);
  50                         list_del(&c->c_link);
  51                         list_add(&c->c_link, &conn_list);
  52                         GOTO(out, c);
  53                 }
  54         }
  55
  56         /* FIXME: this should be a slab once we can validate slab addresses
  57          * without OOPSing */
  58         OBD_ALLOC(c, sizeof(*c));
  59         if (c == NULL)
  60                 GOTO(out, c);
  61
  62         c->c_level = LUSTRE_CONN_NEW;
  63         c->c_xid_in = 1;
  64         c->c_xid_out = 1;
  65         c->c_generation = 1;
  66         c->c_epoch = 1;
  67         c->c_bootcount = 0;
  68         atomic_set(&c->c_refcount, 0);
  69         ptlrpc_connection_addref(c);
  70         spin_lock_init(&c->c_lock);
  71
  72         memcpy(&c->c_peer, peer, sizeof(c->c_peer));
  73         list_add(&c->c_link, &conn_list);
  74
  75         EXIT;
  76  out:
  77         spin_unlock(&conn_lock);
  78         return c;
  79 }
  80
  81 int ptlrpc_put_connection(struct ptlrpc_connection *c)
  82 {
  83         int rc = 0;
  84         ENTRY;
  85
  86         CDEBUG(D_INFO, "connection=%p\n", c);
  87         if (atomic_dec_and_test(&c->c_refcount)) {
  88                 spin_lock(&conn_lock);
  89                 list_del(&c->c_link);
  90                 list_add(&c->c_link, &conn_unused_list);
  91                 spin_unlock(&conn_lock);
  92                 rc = 1;
  93         }
  94         if (atomic_read(&c->c_refcount) < 0)
  95                 CDEBUG(D_INFO, "refcount < 0 for connection %p!\n", c);
  96
  97         RETURN(rc);
  98 }
  99
 100 struct ptlrpc_connection *ptlrpc_connection_addref(struct ptlrpc_connection *c)
 101 {
 102         ENTRY;
 103         CDEBUG(D_INFO, "connection=%p\n", c);
 104         atomic_inc(&c->c_refcount);
 105         RETURN(c);
 106 }
 107
 108 void ptlrpc_init_connection(void)
 109 {
 110         INIT_LIST_HEAD(&conn_list);
 111         INIT_LIST_HEAD(&conn_unused_list);
 112         conn_lock = SPIN_LOCK_UNLOCKED;
 113 }
 114
 115 void ptlrpc_cleanup_connection(void)
 116 {
 117         struct list_head *tmp, *pos;
 118         struct ptlrpc_connection *c;
 119
 120         spin_lock(&conn_lock);
 121         list_for_each_safe(tmp, pos, &conn_unused_list) {
 122                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
 123                 list_del(&c->c_link);
 124                 OBD_FREE(c, sizeof(*c));
 125         }
 126         list_for_each_safe(tmp, pos, &conn_list) {
 127                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
 128                 CERROR("Connection %p has refcount %d at cleanup (nid=%lu)!\n",
 129                        c, atomic_read(&c->c_refcount),
 130                        (unsigned long)c->c_peer.peer_nid);
 131                 list_del(&c->c_link);
 132                 OBD_FREE(c, sizeof(*c));
 133         }
 134         spin_unlock(&conn_lock);
 135 }