patch-2.4.25 linux-2.4.25/fs/xfs/support/uuid.c

• Lines: 152
• Date: 2004-02-18 05:36:32.000000000 -0800
• Orig file: linux-2.4.24/fs/xfs/support/uuid.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.24/fs/xfs/support/uuid.c linux-2.4.25/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);
+}