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 EXPORT_SYMTAB
  24
  25 #define DEBUG_SUBSYSTEM S_RPC
  26
  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 struct ptlrpc_connection *ptlrpc_get_connection(struct lustre_peer *peer)
  34 {
  35         struct list_head *tmp, *pos;
  36         struct ptlrpc_connection *c;
  37         ENTRY;
  38
  39         spin_lock(&conn_lock);
  40         list_for_each(tmp, &conn_list) {
  41                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
  42                 if (memcmp(peer, &c->c_peer, sizeof(*peer)) == 0) {
  43                         atomic_inc(&c->c_refcount);
  44                         GOTO(out, c);
  45                 }
  46         }
  47
  48         list_for_each_safe(tmp, pos, &conn_unused_list) {
  49                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
  50                 if (memcmp(peer, &c->c_peer, sizeof(*peer)) == 0) {
  51                         atomic_inc(&c->c_refcount);
  52                         list_del(&c->c_link);
  53                         list_add(&c->c_link, &conn_list);
  54                         GOTO(out, c);
  55                 }
  56         }
  57
  58         /* FIXME: this should be a slab once we can validate slab addresses
  59          * without OOPSing */
  60         OBD_ALLOC(c, sizeof(*c));
  61         if (c == NULL)
  62                 GOTO(out, c);
  63
  64         c->c_xid_in = 1;
  65         c->c_xid_out = 1;
  66         c->c_generation = 1;
  67         c->c_epoch = 1;
  68         c->c_bootcount = 0;
  69         atomic_set(&c->c_refcount, 1);
  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
  85         if (atomic_dec_and_test(&c->c_refcount)) {
  86                 spin_lock(&conn_lock);
  87                 list_del(&c->c_link);
  88                 list_add(&c->c_link, &conn_unused_list);
  89                 spin_unlock(&conn_lock);
  90                 rc = 1;
  91         }
  92
  93         return rc;
  94 }
  95
  96 struct ptlrpc_connection *ptlrpc_connection_addref(struct ptlrpc_connection *c)
  97 {
  98         atomic_inc(&c->c_refcount);
  99         return c;
 100 }
 101
 102 void ptlrpc_init_connection(void)
 103 {
 104         INIT_LIST_HEAD(&conn_list);
 105         INIT_LIST_HEAD(&conn_unused_list);
 106         conn_lock = SPIN_LOCK_UNLOCKED;
 107 }
 108
 109 void ptlrpc_cleanup_connection(void)
 110 {
 111         struct list_head *tmp, *pos;
 112         struct ptlrpc_connection *c;
 113
 114         spin_lock(&conn_lock);
 115         list_for_each_safe(tmp, pos, &conn_unused_list) {
 116                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
 117                 list_del(&c->c_link);
 118                 OBD_FREE(c, sizeof(*c));
 119         }
 120         list_for_each_safe(tmp, pos, &conn_list) {
 121                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
 122                 CERROR("Connection %p has refcount %d at cleanup (nid=%lu)!\n",
 123                        c, atomic_read(&c->c_refcount),
 124                        (unsigned long)c->c_peer.peer_nid);
 125                 list_del(&c->c_link);
 126                 OBD_FREE(c, sizeof(*c));
 127         }
 128         spin_unlock(&conn_lock);
 129 }