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 struct ptlrpc_connection *ptlrpc_get_connection(struct lustre_peer *peer)
  33 {
  34         struct list_head *tmp, *pos;
  35         struct ptlrpc_connection *c;
  36         ENTRY;
  37
  38         spin_lock(&conn_lock);
  39         list_for_each(tmp, &conn_list) {
  40                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
  41                 if (memcmp(peer, &c->c_peer, sizeof(*peer)) == 0) {
  42                         ptlrpc_connection_addref(c);
  43                         GOTO(out, c);
  44                 }
  45         }
  46
  47         list_for_each_safe(tmp, pos, &conn_unused_list) {
  48                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
  49                 if (memcmp(peer, &c->c_peer, sizeof(*peer)) == 0) {
  50                         ptlrpc_connection_addref(c);
  51                         list_del(&c->c_link);
  52                         list_add(&c->c_link, &conn_list);
  53                         GOTO(out, c);
  54                 }
  55         }
  56
  57         /* FIXME: this should be a slab once we can validate slab addresses
  58          * without OOPSing */
  59         OBD_ALLOC(c, sizeof(*c));
  60         if (c == NULL)
  61                 GOTO(out, c);
  62
  63         c->c_level = LUSTRE_CONN_NEW;
  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, 0);
  70         ptlrpc_connection_addref(c);
  71         spin_lock_init(&c->c_lock);
  72
  73         memcpy(&c->c_peer, peer, sizeof(c->c_peer));
  74         list_add(&c->c_link, &conn_list);
  75
  76         EXIT;
  77  out:
  78         spin_unlock(&conn_lock);
  79         return c;
  80 }
  81
  82 int ptlrpc_put_connection(struct ptlrpc_connection *c)
  83 {
  84         int rc = 0;
  85         ENTRY;
  86
  87         CDEBUG(D_INFO, "connection=%p\n", c);
  88         if (atomic_dec_and_test(&c->c_refcount)) {
  89                 spin_lock(&conn_lock);
  90                 list_del(&c->c_link);
  91                 list_add(&c->c_link, &conn_unused_list);
  92                 spin_unlock(&conn_lock);
  93                 rc = 1;
  94         }
  95         if (atomic_read(&c->c_refcount) < 0)
  96                 CDEBUG(D_INFO, "refcount < 0 for connection %p!\n", c);
  97
  98         RETURN(rc);
  99 }
 100
 101 struct ptlrpc_connection *ptlrpc_connection_addref(struct ptlrpc_connection *c)
 102 {
 103         ENTRY;
 104         CDEBUG(D_INFO, "connection=%p\n", c);
 105         atomic_inc(&c->c_refcount);
 106         RETURN(c);
 107 }
 108
 109 void ptlrpc_init_connection(void)
 110 {
 111         INIT_LIST_HEAD(&conn_list);
 112         INIT_LIST_HEAD(&conn_unused_list);
 113         conn_lock = SPIN_LOCK_UNLOCKED;
 114 }
 115
 116 void ptlrpc_cleanup_connection(void)
 117 {
 118         struct list_head *tmp, *pos;
 119         struct ptlrpc_connection *c;
 120
 121         spin_lock(&conn_lock);
 122         list_for_each_safe(tmp, pos, &conn_unused_list) {
 123                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
 124                 list_del(&c->c_link);
 125                 OBD_FREE(c, sizeof(*c));
 126         }
 127         list_for_each_safe(tmp, pos, &conn_list) {
 128                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
 129                 CERROR("Connection %p has refcount %d at cleanup (nid=%lu)!\n",
 130                        c, atomic_read(&c->c_refcount),
 131                        (unsigned long)c->c_peer.peer_nid);
 132                 list_del(&c->c_link);
 133                 OBD_FREE(c, sizeof(*c));
 134         }
 135         spin_unlock(&conn_lock);
 136 }