Merge branch 'linus' into perf/core, to refresh the branch
[cascardo/linux.git] / drivers / staging / lustre / lustre / obdclass / lustre_peer.c
1 /*
2  * GPL HEADER START
3  *
4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 only,
8  * as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful, but
11  * WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * General Public License version 2 for more details (a copy is included
14  * in the LICENSE file that accompanied this code).
15  *
16  * You should have received a copy of the GNU General Public License
17  * version 2 along with this program; If not, see
18  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
19  *
20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21  * CA 95054 USA or visit www.sun.com if you need additional information or
22  * have any questions.
23  *
24  * GPL HEADER END
25  */
26 /*
27  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
28  * Use is subject to license terms.
29  *
30  * Copyright (c) 2011, 2012, Intel Corporation.
31  */
32 /*
33  * This file is part of Lustre, http://www.lustre.org/
34  * Lustre is a trademark of Sun Microsystems, Inc.
35  */
36
37 #define DEBUG_SUBSYSTEM S_RPC
38
39 #include "../include/obd.h"
40 #include "../include/obd_support.h"
41 #include "../include/obd_class.h"
42 #include "../include/lustre_lib.h"
43 #include "../include/lustre_ha.h"
44 #include "../include/lustre_net.h"
45 #include "../include/lprocfs_status.h"
46
47 #define NIDS_MAX        32
48
49 struct uuid_nid_data {
50         struct list_head       un_list;
51         struct obd_uuid  un_uuid;
52         int           un_nid_count;
53         lnet_nid_t       un_nids[NIDS_MAX];
54 };
55
56 /* FIXME: This should probably become more elegant than a global linked list */
57 static struct list_head g_uuid_list;
58 static spinlock_t       g_uuid_lock;
59
60 void class_init_uuidlist(void)
61 {
62         INIT_LIST_HEAD(&g_uuid_list);
63         spin_lock_init(&g_uuid_lock);
64 }
65
66 void class_exit_uuidlist(void)
67 {
68         /* delete all */
69         class_del_uuid(NULL);
70 }
71
72 int lustre_uuid_to_peer(const char *uuid, lnet_nid_t *peer_nid, int index)
73 {
74         struct uuid_nid_data *data;
75         struct obd_uuid tmp;
76         int rc = -ENOENT;
77
78         obd_str2uuid(&tmp, uuid);
79         spin_lock(&g_uuid_lock);
80         list_for_each_entry(data, &g_uuid_list, un_list) {
81                 if (obd_uuid_equals(&data->un_uuid, &tmp)) {
82                         if (index >= data->un_nid_count)
83                                 break;
84
85                         rc = 0;
86                         *peer_nid = data->un_nids[index];
87                         break;
88                 }
89         }
90         spin_unlock(&g_uuid_lock);
91         return rc;
92 }
93 EXPORT_SYMBOL(lustre_uuid_to_peer);
94
95 /* Add a nid to a niduuid.  Multiple nids can be added to a single uuid;
96  * LNET will choose the best one.
97  */
98 int class_add_uuid(const char *uuid, __u64 nid)
99 {
100         struct uuid_nid_data *data, *entry;
101         int found = 0;
102
103         LASSERT(nid != 0);  /* valid newconfig NID is never zero */
104
105         if (strlen(uuid) > UUID_MAX - 1)
106                 return -EOVERFLOW;
107
108         data = kzalloc(sizeof(*data), GFP_NOFS);
109         if (!data)
110                 return -ENOMEM;
111
112         obd_str2uuid(&data->un_uuid, uuid);
113         data->un_nids[0] = nid;
114         data->un_nid_count = 1;
115
116         spin_lock(&g_uuid_lock);
117         list_for_each_entry(entry, &g_uuid_list, un_list) {
118                 if (obd_uuid_equals(&entry->un_uuid, &data->un_uuid)) {
119                         int i;
120
121                         found = 1;
122                         for (i = 0; i < entry->un_nid_count; i++)
123                                 if (nid == entry->un_nids[i])
124                                         break;
125
126                         if (i == entry->un_nid_count) {
127                                 LASSERT(entry->un_nid_count < NIDS_MAX);
128                                 entry->un_nids[entry->un_nid_count++] = nid;
129                         }
130                         break;
131                 }
132         }
133         if (!found)
134                 list_add(&data->un_list, &g_uuid_list);
135         spin_unlock(&g_uuid_lock);
136
137         if (found) {
138                 CDEBUG(D_INFO, "found uuid %s %s cnt=%d\n", uuid,
139                        libcfs_nid2str(nid), entry->un_nid_count);
140                 kfree(data);
141         } else {
142                 CDEBUG(D_INFO, "add uuid %s %s\n", uuid, libcfs_nid2str(nid));
143         }
144         return 0;
145 }
146 EXPORT_SYMBOL(class_add_uuid);
147
148 /* Delete the nids for one uuid if specified, otherwise delete all */
149 int class_del_uuid(const char *uuid)
150 {
151         LIST_HEAD(deathrow);
152         struct uuid_nid_data *data;
153         struct uuid_nid_data *temp;
154
155         spin_lock(&g_uuid_lock);
156         if (uuid) {
157                 struct obd_uuid tmp;
158
159                 obd_str2uuid(&tmp, uuid);
160                 list_for_each_entry(data, &g_uuid_list, un_list) {
161                         if (obd_uuid_equals(&data->un_uuid, &tmp)) {
162                                 list_move(&data->un_list, &deathrow);
163                                 break;
164                         }
165                 }
166         } else {
167                 list_splice_init(&g_uuid_list, &deathrow);
168         }
169         spin_unlock(&g_uuid_lock);
170
171         if (uuid && list_empty(&deathrow)) {
172                 CDEBUG(D_INFO, "Try to delete a non-existent uuid %s\n", uuid);
173                 return -EINVAL;
174         }
175
176         list_for_each_entry_safe(data, temp, &deathrow, un_list) {
177                 list_del(&data->un_list);
178
179                 CDEBUG(D_INFO, "del uuid %s %s/%d\n",
180                        obd_uuid2str(&data->un_uuid),
181                        libcfs_nid2str(data->un_nids[0]),
182                        data->un_nid_count);
183
184                 kfree(data);
185         }
186
187         return 0;
188 }
189
190 /* check if @nid exists in nid list of @uuid */
191 int class_check_uuid(struct obd_uuid *uuid, __u64 nid)
192 {
193         struct uuid_nid_data *entry;
194         int found = 0;
195
196         CDEBUG(D_INFO, "check if uuid %s has %s.\n",
197                obd_uuid2str(uuid), libcfs_nid2str(nid));
198
199         spin_lock(&g_uuid_lock);
200         list_for_each_entry(entry, &g_uuid_list, un_list) {
201                 int i;
202
203                 if (!obd_uuid_equals(&entry->un_uuid, uuid))
204                         continue;
205
206                 /* found the uuid, check if it has @nid */
207                 for (i = 0; i < entry->un_nid_count; i++) {
208                         if (entry->un_nids[i] == nid) {
209                                 found = 1;
210                                 break;
211                         }
212                 }
213                 break;
214         }
215         spin_unlock(&g_uuid_lock);
216         return found;
217 }
218 EXPORT_SYMBOL(class_check_uuid);