linux-sg2042/fs/xfs/support/uuid.c

152 lines
3.8 KiB
C

/*
* 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);
}