1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2 * vim:expandtab:shiftwidth=8:tabstop=8:
6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 only,
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12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License version 2 for more details (a copy is included
16 * in the LICENSE file that accompanied this code).
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20 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
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23 * CA 95054 USA or visit www.sun.com if you need additional information or
29 * Copyright 2008 Sun Microsystems, Inc. All rights reserved
30 * Use is subject to license terms.
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
37 #define DEBUG_SUBSYSTEM S_RPC
39 #include <obd_support.h>
40 #include <obd_class.h>
41 #include <lustre_net.h>
43 #include <liblustre.h>
46 #include "ptlrpc_internal.h"
48 static cfs_hash_t *conn_hash = NULL;
49 static cfs_hash_ops_t conn_hash_ops;
51 struct ptlrpc_connection *
52 ptlrpc_connection_get(lnet_process_id_t peer, lnet_nid_t self,
53 struct obd_uuid *uuid)
55 struct ptlrpc_connection *conn, *conn2;
58 conn = cfs_hash_lookup(conn_hash, &peer);
68 INIT_HLIST_NODE(&conn->c_hash);
69 atomic_set(&conn->c_refcount, 1);
71 obd_str2uuid(&conn->c_remote_uuid, uuid->uuid);
74 * Add the newly created conn to the hash, on key collision we
75 * lost a racing addition and must destroy our newly allocated
76 * connection. The object which exists in the has will be
77 * returned and may be compared against out object.
79 conn2 = cfs_hash_findadd_unique(conn_hash, &peer, &conn->c_hash);
86 CDEBUG(D_INFO, "conn=%p refcount %d to %s\n",
87 conn, atomic_read(&conn->c_refcount),
88 libcfs_nid2str(conn->c_peer.nid));
92 int ptlrpc_connection_put(struct ptlrpc_connection *conn)
100 LASSERT(!hlist_unhashed(&conn->c_hash));
103 * We do not remove connection from hashtable and
104 * do not free it even if last caller released ref,
105 * as we want to have it cached for the case it is
108 * Deallocating it and later creating new connection
109 * again would be wastful. This way we also avoid
110 * expensive locking to protect things from get/put
111 * race when found cached connection is freed by
112 * ptlrpc_connection_put().
114 * It will be freed later in module unload time,
115 * when ptlrpc_connection_fini()->lh_exit->conn_exit()
118 if (atomic_dec_return(&conn->c_refcount) == 1)
121 CDEBUG(D_INFO, "PUT conn=%p refcount %d to %s\n",
122 conn, atomic_read(&conn->c_refcount),
123 libcfs_nid2str(conn->c_peer.nid));
128 struct ptlrpc_connection *
129 ptlrpc_connection_addref(struct ptlrpc_connection *conn)
133 atomic_inc(&conn->c_refcount);
134 CDEBUG(D_INFO, "conn=%p refcount %d to %s\n",
135 conn, atomic_read(&conn->c_refcount),
136 libcfs_nid2str(conn->c_peer.nid));
141 int ptlrpc_connection_init(void)
145 conn_hash = cfs_hash_create("CONN_HASH",
148 &conn_hash_ops, CFS_HASH_REHASH);
155 void ptlrpc_connection_fini(void) {
157 cfs_hash_destroy(conn_hash);
162 * Hash operations for net_peer<->connection
165 conn_hashfn(cfs_hash_t *hs, void *key, unsigned mask)
167 return cfs_hash_djb2_hash(key, sizeof(lnet_process_id_t), mask);
171 conn_compare(void *key, struct hlist_node *hnode)
173 struct ptlrpc_connection *conn;
174 lnet_process_id_t *conn_key;
176 LASSERT(key != NULL);
177 conn_key = (lnet_process_id_t*)key;
178 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
180 return conn_key->nid == conn->c_peer.nid &&
181 conn_key->pid == conn->c_peer.pid;
185 conn_key(struct hlist_node *hnode)
187 struct ptlrpc_connection *conn;
188 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
189 return &conn->c_peer;
193 conn_get(struct hlist_node *hnode)
195 struct ptlrpc_connection *conn;
197 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
198 atomic_inc(&conn->c_refcount);
204 conn_put(struct hlist_node *hnode)
206 struct ptlrpc_connection *conn;
208 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
209 atomic_dec(&conn->c_refcount);
215 conn_exit(struct hlist_node *hnode)
217 struct ptlrpc_connection *conn;
219 conn = hlist_entry(hnode, struct ptlrpc_connection, c_hash);
221 * Nothing should be left. Connection user put it and
222 * connection also was deleted from table by this time
223 * so we should have 0 refs.
225 LASSERTF(atomic_read(&conn->c_refcount) == 0,
226 "Busy connection with %d refs\n",
227 atomic_read(&conn->c_refcount));
231 static cfs_hash_ops_t conn_hash_ops = {
232 .hs_hash = conn_hashfn,
233 .hs_compare = conn_compare,
237 .hs_exit = conn_exit,