support for mount by label (not yet tested)
Also adds findfs applet. Closes bug 1143.

diff --git a/util-linux/volume_id/udf.c b/util-linux/volume_id/udf.c
new file mode 100644
index 0000000..5cdb49c
--- /dev/null
+++ b/util-linux/volume_id/udf.c
@@ -0,0 +1,172 @@
+/*
+ * volume_id - reads filesystem label and uuid
+ *
+ * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
+ *
+ *	This library is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU Lesser General Public
+ *	License as published by the Free Software Foundation; either
+ *	version 2.1 of the License, or (at your option) any later version.
+ *
+ *	This library is distributed in the hope that it will be useful,
+ *	but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ *	Lesser General Public License for more details.
+ *
+ *	You should have received a copy of the GNU Lesser General Public
+ *	License along with this library; if not, write to the Free Software
+ *	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "volume_id_internal.h"
+
+struct volume_descriptor {
+	struct descriptor_tag {
+		uint16_t	id;
+		uint16_t	version;
+		uint8_t		checksum;
+		uint8_t		reserved;
+		uint16_t	serial;
+		uint16_t	crc;
+		uint16_t	crc_len;
+		uint32_t	location;
+	} __attribute__((__packed__)) tag;
+	union {
+		struct anchor_descriptor {
+			uint32_t	length;
+			uint32_t	location;
+		} __attribute__((__packed__)) anchor;
+		struct primary_descriptor {
+			uint32_t	seq_num;
+			uint32_t	desc_num;
+			struct dstring {
+				uint8_t	clen;
+				uint8_t	c[31];
+			} __attribute__((__packed__)) ident;
+		} __attribute__((__packed__)) primary;
+	} __attribute__((__packed__)) type;
+} __attribute__((__packed__));
+
+struct volume_structure_descriptor {
+	uint8_t		type;
+	uint8_t		id[5];
+	uint8_t		version;
+} __attribute__((__packed__));
+
+#define UDF_VSD_OFFSET			0x8000
+
+int volume_id_probe_udf(struct volume_id *id, uint64_t off)
+{
+	struct volume_descriptor *vd;
+	struct volume_structure_descriptor *vsd;
+	unsigned bs;
+	unsigned b;
+	unsigned type;
+	unsigned count;
+	unsigned loc;
+	unsigned clen;
+
+	dbg("probing at offset 0x%llx", (unsigned long long) off);
+
+	vsd = volume_id_get_buffer(id, off + UDF_VSD_OFFSET, 0x200);
+	if (vsd == NULL)
+		return -1;
+
+	if (memcmp(vsd->id, "NSR02", 5) == 0)
+		goto blocksize;
+	if (memcmp(vsd->id, "NSR03", 5) == 0)
+		goto blocksize;
+	if (memcmp(vsd->id, "BEA01", 5) == 0)
+		goto blocksize;
+	if (memcmp(vsd->id, "BOOT2", 5) == 0)
+		goto blocksize;
+	if (memcmp(vsd->id, "CD001", 5) == 0)
+		goto blocksize;
+	if (memcmp(vsd->id, "CDW02", 5) == 0)
+		goto blocksize;
+	if (memcmp(vsd->id, "TEA03", 5) == 0)
+		goto blocksize;
+	return -1;
+
+blocksize:
+	/* search the next VSD to get the logical block size of the volume */
+	for (bs = 0x800; bs < 0x8000; bs += 0x800) {
+		vsd = volume_id_get_buffer(id, off + UDF_VSD_OFFSET + bs, 0x800);
+		if (vsd == NULL)
+			return -1;
+		dbg("test for blocksize: 0x%x", bs);
+		if (vsd->id[0] != '\0')
+			goto nsr;
+	}
+	return -1;
+
+nsr:
+	/* search the list of VSDs for a NSR descriptor */
+	for (b = 0; b < 64; b++) {
+		vsd = volume_id_get_buffer(id, off + UDF_VSD_OFFSET + (b * bs), 0x800);
+		if (vsd == NULL)
+			return -1;
+
+		dbg("vsd: %c%c%c%c%c",
+		    vsd->id[0], vsd->id[1], vsd->id[2], vsd->id[3], vsd->id[4]);
+
+		if (vsd->id[0] == '\0')
+			return -1;
+		if (memcmp(vsd->id, "NSR02", 5) == 0)
+			goto anchor;
+		if (memcmp(vsd->id, "NSR03", 5) == 0)
+			goto anchor;
+	}
+	return -1;
+
+anchor:
+	/* read anchor volume descriptor */
+	vd = volume_id_get_buffer(id, off + (256 * bs), 0x200);
+	if (vd == NULL)
+		return -1;
+
+	type = le16_to_cpu(vd->tag.id);
+	if (type != 2) /* TAG_ID_AVDP */
+		goto found;
+
+	/* get desriptor list address and block count */
+	count = le32_to_cpu(vd->type.anchor.length) / bs;
+	loc = le32_to_cpu(vd->type.anchor.location);
+	dbg("0x%x descriptors starting at logical secor 0x%x", count, loc);
+
+	/* pick the primary descriptor from the list */
+	for (b = 0; b < count; b++) {
+		vd = volume_id_get_buffer(id, off + ((loc + b) * bs), 0x200);
+		if (vd == NULL)
+			return -1;
+
+		type = le16_to_cpu(vd->tag.id);
+		dbg("descriptor type %i", type);
+
+		/* check validity */
+		if (type == 0)
+			goto found;
+		if (le32_to_cpu(vd->tag.location) != loc + b)
+			goto found;
+
+		if (type == 1) /* TAG_ID_PVD */
+			goto pvd;
+	}
+	goto found;
+
+ pvd:
+	volume_id_set_label_raw(id, &(vd->type.primary.ident.clen), 32);
+
+	clen = vd->type.primary.ident.clen;
+	dbg("label string charsize=%i bit", clen);
+	if (clen == 8)
+		volume_id_set_label_string(id, vd->type.primary.ident.c, 31);
+	else if (clen == 16)
+		volume_id_set_label_unicode16(id, vd->type.primary.ident.c, BE, 31);
+
+ found:
+	volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
+	id->type = "udf";
+
+	return 0;
+}