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1da177e4 | 1 | /* |
7b718769 NS |
2 | * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc. |
3 | * All Rights Reserved. | |
1da177e4 | 4 | * |
7b718769 NS |
5 | * This program is free software; you can redistribute it and/or |
6 | * modify it under the terms of the GNU General Public License as | |
1da177e4 LT |
7 | * published by the Free Software Foundation. |
8 | * | |
7b718769 NS |
9 | * This program is distributed in the hope that it would be useful, |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
1da177e4 | 13 | * |
7b718769 NS |
14 | * You should have received a copy of the GNU General Public License |
15 | * along with this program; if not, write the Free Software Foundation, | |
16 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
1da177e4 | 17 | */ |
1da177e4 LT |
18 | #include <xfs.h> |
19 | ||
20 | static mutex_t uuid_monitor; | |
21 | static int uuid_table_size; | |
22 | static uuid_t *uuid_table; | |
23 | ||
24 | void | |
25 | uuid_init(void) | |
26 | { | |
794ee1ba | 27 | mutex_init(&uuid_monitor); |
1da177e4 LT |
28 | } |
29 | ||
794fe2dc CH |
30 | |
31 | /* IRIX interpretation of an uuid_t */ | |
32 | typedef struct { | |
33 | __be32 uu_timelow; | |
34 | __be16 uu_timemid; | |
35 | __be16 uu_timehi; | |
36 | __be16 uu_clockseq; | |
37 | __be16 uu_node[3]; | |
38 | } xfs_uu_t; | |
39 | ||
1da177e4 LT |
40 | /* |
41 | * uuid_getnodeuniq - obtain the node unique fields of a UUID. | |
42 | * | |
43 | * This is not in any way a standard or condoned UUID function; | |
44 | * it just something that's needed for user-level file handles. | |
45 | */ | |
46 | void | |
47 | uuid_getnodeuniq(uuid_t *uuid, int fsid [2]) | |
48 | { | |
794fe2dc | 49 | xfs_uu_t *uup = (xfs_uu_t *)uuid; |
1da177e4 | 50 | |
794fe2dc CH |
51 | fsid[0] = (be16_to_cpu(uup->uu_clockseq) << 16) | |
52 | be16_to_cpu(uup->uu_timemid); | |
53 | fsid[1] = be16_to_cpu(uup->uu_timelow); | |
1da177e4 LT |
54 | } |
55 | ||
56 | void | |
57 | uuid_create_nil(uuid_t *uuid) | |
58 | { | |
59 | memset(uuid, 0, sizeof(*uuid)); | |
60 | } | |
61 | ||
62 | int | |
63 | uuid_is_nil(uuid_t *uuid) | |
64 | { | |
65 | int i; | |
66 | char *cp = (char *)uuid; | |
67 | ||
68 | if (uuid == NULL) | |
69 | return 0; | |
70 | /* implied check of version number here... */ | |
71 | for (i = 0; i < sizeof *uuid; i++) | |
72 | if (*cp++) return 0; /* not nil */ | |
73 | return 1; /* is nil */ | |
74 | } | |
75 | ||
76 | int | |
77 | uuid_equal(uuid_t *uuid1, uuid_t *uuid2) | |
78 | { | |
79 | return memcmp(uuid1, uuid2, sizeof(uuid_t)) ? 0 : 1; | |
80 | } | |
81 | ||
82 | /* | |
83 | * Given a 128-bit uuid, return a 64-bit value by adding the top and bottom | |
84 | * 64-bit words. NOTE: This function can not be changed EVER. Although | |
85 | * brain-dead, some applications depend on this 64-bit value remaining | |
86 | * persistent. Specifically, DMI vendors store the value as a persistent | |
87 | * filehandle. | |
88 | */ | |
89 | __uint64_t | |
90 | uuid_hash64(uuid_t *uuid) | |
91 | { | |
92 | __uint64_t *sp = (__uint64_t *)uuid; | |
93 | ||
94 | return sp[0] + sp[1]; | |
95 | } | |
96 | ||
97 | int | |
98 | uuid_table_insert(uuid_t *uuid) | |
99 | { | |
100 | int i, hole; | |
101 | ||
794ee1ba | 102 | mutex_lock(&uuid_monitor); |
1da177e4 LT |
103 | for (i = 0, hole = -1; i < uuid_table_size; i++) { |
104 | if (uuid_is_nil(&uuid_table[i])) { | |
105 | hole = i; | |
106 | continue; | |
107 | } | |
108 | if (uuid_equal(uuid, &uuid_table[i])) { | |
109 | mutex_unlock(&uuid_monitor); | |
110 | return 0; | |
111 | } | |
112 | } | |
113 | if (hole < 0) { | |
114 | uuid_table = kmem_realloc(uuid_table, | |
115 | (uuid_table_size + 1) * sizeof(*uuid_table), | |
116 | uuid_table_size * sizeof(*uuid_table), | |
117 | KM_SLEEP); | |
118 | hole = uuid_table_size++; | |
119 | } | |
120 | uuid_table[hole] = *uuid; | |
121 | mutex_unlock(&uuid_monitor); | |
122 | return 1; | |
123 | } | |
124 | ||
125 | void | |
126 | uuid_table_remove(uuid_t *uuid) | |
127 | { | |
128 | int i; | |
129 | ||
794ee1ba | 130 | mutex_lock(&uuid_monitor); |
1da177e4 LT |
131 | for (i = 0; i < uuid_table_size; i++) { |
132 | if (uuid_is_nil(&uuid_table[i])) | |
133 | continue; | |
134 | if (!uuid_equal(uuid, &uuid_table[i])) | |
135 | continue; | |
136 | uuid_create_nil(&uuid_table[i]); | |
137 | break; | |
138 | } | |
139 | ASSERT(i < uuid_table_size); | |
140 | mutex_unlock(&uuid_monitor); | |
141 | } |