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[fs/lustre-release.git] / 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 the Lustre file system, http://www.lustre.org
7  *   Lustre is a trademark of Cluster File Systems, Inc.
8  *
9  *   You may have signed or agreed to another license before downloading
10  *   this software.  If so, you are bound by the terms and conditions
11  *   of that agreement, and the following does not apply to you.  See the
12  *   LICENSE file included with this distribution for more information.
13  *
14  *   If you did not agree to a different license, then this copy of Lustre
15  *   is open source software; you can redistribute it and/or modify it
16  *   under the terms of version 2 of the GNU General Public License as
17  *   published by the Free Software Foundation.
18  *
19  *   In either case, Lustre is distributed in the hope that it will be
20  *   useful, but WITHOUT ANY WARRANTY; without even the implied warranty
21  *   of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
22  *   license text for more details.
23  *
24  */
25
26 #define DEBUG_SUBSYSTEM S_RPC
27 #ifdef __KERNEL__
28 #include <obd_support.h>
29 #include <obd_class.h>
30 #include <lustre_net.h>
31 #else
32 #include <liblustre.h>
33 #endif
34
35 #include "ptlrpc_internal.h"
36 #include <class_hash.h>
37
38 static spinlock_t conn_lock;
39 static struct list_head conn_list;
40 static struct list_head conn_unused_list;
41 static struct lustre_class_hash_body *conn_hash_body;
42 static struct lustre_class_hash_body *conn_unused_hash_body;
43
44 extern struct lustre_hash_operations conn_hash_operations;
45
46 void ptlrpc_dump_connections(void)
47 {
48         struct list_head *tmp;
49         struct ptlrpc_connection *c;
50         ENTRY;
51
52         list_for_each(tmp, &conn_list) {
53                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
54                 CERROR("Connection %p/%s has refcount %d (nid=%s->%s)\n",
55                        c, c->c_remote_uuid.uuid, atomic_read(&c->c_refcount),
56                        libcfs_nid2str(c->c_self), 
57                        libcfs_nid2str(c->c_peer.nid));
58         }
59         EXIT;
60 }
61
62 struct ptlrpc_connection*
63 ptlrpc_lookup_conn_locked (lnet_process_id_t peer)
64 {
65         struct ptlrpc_connection *c;
66
67         c = lustre_hash_get_object_by_key(conn_hash_body, &peer);
68         if (c != NULL)
69                 return c;
70
71         c = lustre_hash_get_object_by_key(conn_unused_hash_body, &peer);
72         if (c != NULL)
73                 return c;
74
75         return NULL;
76 }
77
78
79 struct ptlrpc_connection *ptlrpc_get_connection(lnet_process_id_t peer,
80                                                 lnet_nid_t self, struct obd_uuid *uuid)
81 {
82         struct ptlrpc_connection *c;
83         struct ptlrpc_connection *c2;
84         int rc = 0;
85         ENTRY;
86
87         CDEBUG(D_INFO, "self %s peer %s\n", 
88                libcfs_nid2str(self), libcfs_id2str(peer));
89
90         spin_lock(&conn_lock);
91
92         c = ptlrpc_lookup_conn_locked(peer);
93         
94         spin_unlock(&conn_lock);
95
96         if (c != NULL)
97                 RETURN (c);
98         
99         OBD_ALLOC(c, sizeof(*c));
100         if (c == NULL)
101                 RETURN (NULL);
102
103         atomic_set(&c->c_refcount, 1);
104         c->c_peer = peer;
105         c->c_self = self;
106         if (uuid != NULL)
107                 obd_str2uuid(&c->c_remote_uuid, uuid->uuid);
108
109         spin_lock(&conn_lock);
110
111         c2 = ptlrpc_lookup_conn_locked(peer);
112         if (c2 == NULL) {
113                 list_add(&c->c_link, &conn_list);
114                 rc = lustre_hash_additem_unique(conn_hash_body, &peer, 
115                                                 &c->c_hash);
116                 if (rc != 0) {
117                         list_del(&c->c_link);
118                         CERROR("Cannot add connection to conn_hash_body\n");
119                         goto out_conn;
120                 }
121         }
122
123 out_conn:
124
125         spin_unlock(&conn_lock);
126
127         if (c2 == NULL && rc == 0)
128                 RETURN (c);
129
130         if (c != NULL) 
131                 OBD_FREE(c, sizeof(*c));
132         RETURN (c2);
133 }
134
135 int ptlrpc_put_connection(struct ptlrpc_connection *c)
136 {
137         int rc = 0;
138         lnet_process_id_t peer;
139         ENTRY;
140
141         if (c == NULL) {
142                 CERROR("NULL connection\n");
143                 RETURN(0);
144         }
145
146         peer = c->c_peer;
147
148         CDEBUG (D_INFO, "connection=%p refcount %d to %s\n",
149                 c, atomic_read(&c->c_refcount) - 1, 
150                 libcfs_nid2str(c->c_peer.nid));
151
152         spin_lock(&conn_lock);
153         LASSERT(!hlist_unhashed(&c->c_hash));
154         spin_unlock(&conn_lock);
155
156         if (atomic_dec_return(&c->c_refcount) == 1) {
157
158                 spin_lock(&conn_lock);
159
160                 lustre_hash_delitem(conn_hash_body, &peer, &c->c_hash);
161                 list_del(&c->c_link);
162
163                 list_add(&c->c_link, &conn_unused_list);
164                 rc = lustre_hash_additem_unique(conn_unused_hash_body, &peer, 
165                                                 &c->c_hash);
166                 if (rc != 0) {
167                         spin_unlock(&conn_lock);
168                         CERROR("Cannot hash connection to conn_hash_body\n");
169                         GOTO(ret, rc);
170                 }
171
172                 spin_unlock(&conn_lock);
173                 rc = 1;
174  
175         } 
176
177         if (atomic_read(&c->c_refcount) < 0)
178                 CERROR("connection %p refcount %d!\n",
179                        c, atomic_read(&c->c_refcount));
180 ret :
181
182         RETURN(rc);
183 }
184
185 struct ptlrpc_connection *ptlrpc_connection_addref(struct ptlrpc_connection *c)
186 {
187         ENTRY;
188         atomic_inc(&c->c_refcount);
189         CDEBUG (D_INFO, "connection=%p refcount %d to %s\n",
190                 c, atomic_read(&c->c_refcount),
191                 libcfs_nid2str(c->c_peer.nid));
192         RETURN(c);
193 }
194
195 int ptlrpc_init_connection(void)
196 {
197         int rc = 0;
198         CFS_INIT_LIST_HEAD(&conn_list);
199         rc = lustre_hash_init(&conn_hash_body, "CONN_HASH", 
200                               128, &conn_hash_operations);
201         if (rc)
202                 GOTO(ret, rc);
203
204         CFS_INIT_LIST_HEAD(&conn_unused_list);
205         rc = lustre_hash_init(&conn_unused_hash_body, "CONN_UNUSED_HASH", 
206                               128, &conn_hash_operations);
207         if (rc)
208                 GOTO(ret, rc);
209
210         spin_lock_init(&conn_lock);
211 ret:
212         if (rc) {
213                 lustre_hash_exit(&conn_hash_body);
214                 lustre_hash_exit(&conn_unused_hash_body);
215         }
216         RETURN(rc);
217 }
218
219 void ptlrpc_cleanup_connection(void)
220 {
221         struct list_head *tmp, *pos;
222         struct ptlrpc_connection *c;
223
224         spin_lock(&conn_lock);
225
226         lustre_hash_exit(&conn_unused_hash_body);
227         list_for_each_safe(tmp, pos, &conn_unused_list) {
228                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
229                 list_del(&c->c_link);
230                 OBD_FREE(c, sizeof(*c));
231         }
232
233         lustre_hash_exit(&conn_hash_body);
234         list_for_each_safe(tmp, pos, &conn_list) {
235                 c = list_entry(tmp, struct ptlrpc_connection, c_link);
236                 CERROR("Connection %p/%s has refcount %d (nid=%s)\n",
237                        c, c->c_remote_uuid.uuid, atomic_read(&c->c_refcount),
238                        libcfs_nid2str(c->c_peer.nid));
239                 list_del(&c->c_link);
240                 OBD_FREE(c, sizeof(*c));
241         }
242         spin_unlock(&conn_lock);
243 }