1/* 2 * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc. 3 * All Rights Reserved. 4 * 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 7 * published by the Free Software Foundation. 8 * 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. 13 * 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 17 */ 18#include <xfs.h> 19 20static mutex_t uuid_monitor; 21static int uuid_table_size; 22static uuid_t *uuid_table; 23 24/* IRIX interpretation of an uuid_t */ 25typedef struct { 26 __be32 uu_timelow; 27 __be16 uu_timemid; 28 __be16 uu_timehi; 29 __be16 uu_clockseq; 30 __be16 uu_node[3]; 31} xfs_uu_t; 32 33/* 34 * uuid_getnodeuniq - obtain the node unique fields of a UUID. 35 * 36 * This is not in any way a standard or condoned UUID function; 37 * it just something that's needed for user-level file handles. 38 */ 39void 40uuid_getnodeuniq(uuid_t *uuid, int fsid [2]) 41{ 42 xfs_uu_t *uup = (xfs_uu_t *)uuid; 43 44 fsid[0] = (be16_to_cpu(uup->uu_clockseq) << 16) | 45 be16_to_cpu(uup->uu_timemid); 46 fsid[1] = be32_to_cpu(uup->uu_timelow); 47} 48 49void 50uuid_create_nil(uuid_t *uuid) 51{ 52 memset(uuid, 0, sizeof(*uuid)); 53} 54 55int 56uuid_is_nil(uuid_t *uuid) 57{ 58 int i; 59 char *cp = (char *)uuid; 60 61 if (uuid == NULL) 62 return 0; 63 /* implied check of version number here... */ 64 for (i = 0; i < sizeof *uuid; i++) 65 if (*cp++) return 0; /* not nil */ 66 return 1; /* is nil */ 67} 68 69int 70uuid_equal(uuid_t *uuid1, uuid_t *uuid2) 71{ 72 return memcmp(uuid1, uuid2, sizeof(uuid_t)) ? 0 : 1; 73} 74 75/* 76 * Given a 128-bit uuid, return a 64-bit value by adding the top and bottom 77 * 64-bit words. NOTE: This function can not be changed EVER. Although 78 * brain-dead, some applications depend on this 64-bit value remaining 79 * persistent. Specifically, DMI vendors store the value as a persistent 80 * filehandle. 81 */ 82__uint64_t 83uuid_hash64(uuid_t *uuid) 84{ 85 __uint64_t *sp = (__uint64_t *)uuid; 86 87 return sp[0] + sp[1]; 88} 89 90int 91uuid_table_insert(uuid_t *uuid) 92{ 93 int i, hole; 94 95 mutex_lock(&uuid_monitor); 96 for (i = 0, hole = -1; i < uuid_table_size; i++) { 97 if (uuid_is_nil(&uuid_table[i])) { 98 hole = i; 99 continue; 100 } 101 if (uuid_equal(uuid, &uuid_table[i])) { 102 mutex_unlock(&uuid_monitor); 103 return 0; 104 } 105 } 106 if (hole < 0) { 107 uuid_table = kmem_realloc(uuid_table, 108 (uuid_table_size + 1) * sizeof(*uuid_table), 109 uuid_table_size * sizeof(*uuid_table), 110 KM_SLEEP); 111 hole = uuid_table_size++; 112 } 113 uuid_table[hole] = *uuid; 114 mutex_unlock(&uuid_monitor); 115 return 1; 116} 117 118void 119uuid_table_remove(uuid_t *uuid) 120{ 121 int i; 122 123 mutex_lock(&uuid_monitor); 124 for (i = 0; i < uuid_table_size; i++) { 125 if (uuid_is_nil(&uuid_table[i])) 126 continue; 127 if (!uuid_equal(uuid, &uuid_table[i])) 128 continue; 129 uuid_create_nil(&uuid_table[i]); 130 break; 131 } 132 ASSERT(i < uuid_table_size); 133 mutex_unlock(&uuid_monitor); 134} 135 136void 137uuid_init(void) 138{ 139 mutex_init(&uuid_monitor); 140} 141