diff options
Diffstat (limited to 'fs/xfs/support/uuid.c')
| -rw-r--r-- | fs/xfs/support/uuid.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/fs/xfs/support/uuid.c b/fs/xfs/support/uuid.c new file mode 100644 index 00000000000..81f40cfcb26 --- /dev/null +++ b/fs/xfs/support/uuid.c @@ -0,0 +1,151 @@ +/* + * Copyright (c) 2000-2003 Silicon Graphics, Inc. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it would be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + * + * Further, this software is distributed without any warranty that it is + * free of the rightful claim of any third person regarding infringement + * or the like. Any license provided herein, whether implied or + * otherwise, applies only to this software file. Patent licenses, if + * any, provided herein do not apply to combinations of this program with + * other software, or any other product whatsoever. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write the Free Software Foundation, Inc., 59 + * Temple Place - Suite 330, Boston MA 02111-1307, USA. + * + * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy, + * Mountain View, CA 94043, or: + * + * http://www.sgi.com + * + * For further information regarding this notice, see: + * + * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/ + */ + +#include <xfs.h> + +static mutex_t uuid_monitor; +static int uuid_table_size; +static uuid_t *uuid_table; + +void +uuid_init(void) +{ + mutex_init(&uuid_monitor, MUTEX_DEFAULT, "uuid_monitor"); +} + +/* + * uuid_getnodeuniq - obtain the node unique fields of a UUID. + * + * This is not in any way a standard or condoned UUID function; + * it just something that's needed for user-level file handles. + */ +void +uuid_getnodeuniq(uuid_t *uuid, int fsid [2]) +{ + char *uu = (char *)uuid; + + /* on IRIX, this function assumes big-endian fields within + * the uuid, so we use INT_GET to get the same result on + * little-endian systems + */ + + fsid[0] = (INT_GET(*(u_int16_t*)(uu+8), ARCH_CONVERT) << 16) + + INT_GET(*(u_int16_t*)(uu+4), ARCH_CONVERT); + fsid[1] = INT_GET(*(u_int32_t*)(uu ), ARCH_CONVERT); +} + +void +uuid_create_nil(uuid_t *uuid) +{ + memset(uuid, 0, sizeof(*uuid)); +} + +int +uuid_is_nil(uuid_t *uuid) +{ + int i; + char *cp = (char *)uuid; + + if (uuid == NULL) + return 0; + /* implied check of version number here... */ + for (i = 0; i < sizeof *uuid; i++) + if (*cp++) return 0; /* not nil */ + return 1; /* is nil */ +} + +int +uuid_equal(uuid_t *uuid1, uuid_t *uuid2) +{ + return memcmp(uuid1, uuid2, sizeof(uuid_t)) ? 0 : 1; +} + +/* + * Given a 128-bit uuid, return a 64-bit value by adding the top and bottom + * 64-bit words. NOTE: This function can not be changed EVER. Although + * brain-dead, some applications depend on this 64-bit value remaining + * persistent. Specifically, DMI vendors store the value as a persistent + * filehandle. + */ +__uint64_t +uuid_hash64(uuid_t *uuid) +{ + __uint64_t *sp = (__uint64_t *)uuid; + + return sp[0] + sp[1]; +} + +int +uuid_table_insert(uuid_t *uuid) +{ + int i, hole; + + mutex_lock(&uuid_monitor, PVFS); + for (i = 0, hole = -1; i < uuid_table_size; i++) { + if (uuid_is_nil(&uuid_table[i])) { + hole = i; + continue; + } + if (uuid_equal(uuid, &uuid_table[i])) { + mutex_unlock(&uuid_monitor); + return 0; + } + } + if (hole < 0) { + uuid_table = kmem_realloc(uuid_table, + (uuid_table_size + 1) * sizeof(*uuid_table), + uuid_table_size * sizeof(*uuid_table), + KM_SLEEP); + hole = uuid_table_size++; + } + uuid_table[hole] = *uuid; + mutex_unlock(&uuid_monitor); + return 1; +} + +void +uuid_table_remove(uuid_t *uuid) +{ + int i; + + mutex_lock(&uuid_monitor, PVFS); + for (i = 0; i < uuid_table_size; i++) { + if (uuid_is_nil(&uuid_table[i])) + continue; + if (!uuid_equal(uuid, &uuid_table[i])) + continue; + uuid_create_nil(&uuid_table[i]); + break; + } + ASSERT(i < uuid_table_size); + mutex_unlock(&uuid_monitor); +} |