fs/udf/misc.c - pub/scm/linux/kernel/git/joro/linux - Git at Google

 /*
  * misc.c
  *
  * PURPOSE
  *	Miscellaneous routines for the OSTA-UDF(tm) filesystem.
  *
  * CONTACTS
  *	E-mail regarding any portion of the Linux UDF file system should be
  *	directed to the development team mailing list (run by majordomo):
  *		linux_udf@hpesjro.fc.hp.com
  *
  * COPYRIGHT
  *	This file is distributed under the terms of the GNU General Public
  *	License (GPL). Copies of the GPL can be obtained from:
  *		ftp://prep.ai.mit.edu/pub/gnu/GPL
  *	Each contributing author retains all rights to their own work.
  *
  *  (C) 1998 Dave Boynton
  *  (C) 1998-2000 Ben Fennema
  *  (C) 1999-2000 Stelias Computing Inc
  *
  * HISTORY
  *
  *  04/19/99 blf  partial support for reading/writing specific EA's
  */

 #include "udfdecl.h"

 #if defined(__linux__) && defined(__KERNEL__)

 #include "udf_sb.h"
 #include "udf_i.h"

 #include <linux/fs.h>
 #include <linux/string.h>
 #include <linux/udf_fs.h>

 #else

 #include <sys/types.h>
 #include <stdio.h>
 #include <unistd.h>
 #include <string.h>

 int udf_blocksize=0;
 int udf_errno=0;

 void
 udf_setblocksize(int size)
 {
 	udf_blocksize=size;
 }
 #endif

 Uint32
 udf64_low32(Uint64 indat)
 {
 	return indat & 0x00000000FFFFFFFFULL;
 }

 Uint32
 udf64_high32(Uint64 indat)
 {
 	return indat >> 32;
 }

 #if defined(__linux__) && defined(__KERNEL__)

 extern struct buffer_head *
 udf_tgetblk(struct super_block *sb, int block)
 {
 	if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV))
 		return sb_getblk(sb, udf_fixed_to_variable(block));
 	else
 		return sb_getblk(sb, block);
 }

 extern struct buffer_head *
 udf_tread(struct super_block *sb, int block)
 {
 	if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV))
 		return sb_bread(sb, udf_fixed_to_variable(block));
 	else
 		return sb_bread(sb, block);
 }

 extern struct GenericAttrFormat *
 udf_add_extendedattr(struct inode * inode, Uint32 size, Uint32 type,
 	Uint8 loc, struct buffer_head **bh)
 {
 	Uint8 *ea = NULL, *ad = NULL;
 	long_ad eaicb;
 	int offset;

 	*bh = udf_tread(inode->i_sb, inode->i_ino);

 	if (UDF_I_EXTENDED_FE(inode) == 0)
 	{
 		struct FileEntry *fe;

 		fe = (struct FileEntry *)(*bh)->b_data;
 		eaicb = lela_to_cpu(fe->extendedAttrICB);
 		offset = sizeof(struct FileEntry);
 	}
 	else
 	{
 		struct ExtendedFileEntry *efe;

 		efe = (struct ExtendedFileEntry *)(*bh)->b_data;
 		eaicb = lela_to_cpu(efe->extendedAttrICB);
 		offset = sizeof(struct ExtendedFileEntry);
 	}

 	ea = &(*bh)->b_data[offset];
 	if (UDF_I_LENEATTR(inode))
 		offset += UDF_I_LENEATTR(inode);
 	else
 		size += sizeof(struct ExtendedAttrHeaderDesc);

 	ad = &(*bh)->b_data[offset];
 	if (UDF_I_LENALLOC(inode))
 		offset += UDF_I_LENALLOC(inode);

 	offset = inode->i_sb->s_blocksize - offset;

 	/* TODO - Check for FreeEASpace */

 	if (loc & 0x01 && offset >= size)
 	{
 		struct ExtendedAttrHeaderDesc *eahd;
 		eahd = (struct ExtendedAttrHeaderDesc *)ea;

 		if (UDF_I_LENALLOC(inode))
 		{
 			memmove(&ad[size], ad, UDF_I_LENALLOC(inode));
 		}

 		if (UDF_I_LENEATTR(inode))
 		{
 			/* check checksum/crc */
 			if (le16_to_cpu(eahd->descTag.tagIdent) != TID_EXTENDED_ATTRE_HEADER_DESC ||
 				le32_to_cpu(eahd->descTag.tagLocation) != UDF_I_LOCATION(inode).logicalBlockNum)
 			{
 				udf_release_data(*bh);
 				return NULL;
 			}
 		}
 		else
 		{
 			size -= sizeof(struct ExtendedAttrHeaderDesc);
 			UDF_I_LENEATTR(inode) += sizeof(struct ExtendedAttrHeaderDesc);
 			eahd->descTag.tagIdent = cpu_to_le16(TID_EXTENDED_ATTRE_HEADER_DESC);
 			eahd->descTag.descVersion = cpu_to_le16(2);
 			eahd->descTag.tagSerialNum = cpu_to_le16(1);
 			eahd->descTag.tagLocation = cpu_to_le32(UDF_I_LOCATION(inode).logicalBlockNum);
 			eahd->impAttrLocation = cpu_to_le32(0xFFFFFFFF);
 			eahd->appAttrLocation = cpu_to_le32(0xFFFFFFFF);
 		}

 		offset = UDF_I_LENEATTR(inode);
 		if (type < 2048)
 		{
 			if (le32_to_cpu(eahd->appAttrLocation) < UDF_I_LENEATTR(inode))
 			{
 				Uint32 aal = le32_to_cpu(eahd->appAttrLocation);
 				memmove(&ea[offset - aal + size],
 					&ea[aal], offset - aal);
 				offset -= aal;
 				eahd->appAttrLocation = cpu_to_le32(aal + size);
 			}
 			if (le32_to_cpu(eahd->impAttrLocation) < UDF_I_LENEATTR(inode))
 			{
 				Uint32 ial = le32_to_cpu(eahd->impAttrLocation);
 				memmove(&ea[offset - ial + size],
 					&ea[ial], offset - ial);
 				offset -= ial;
 				eahd->impAttrLocation = cpu_to_le32(ial + size);
 			}
 		}
 		else if (type < 65536)
 		{
 			if (le32_to_cpu(eahd->appAttrLocation) < UDF_I_LENEATTR(inode))
 			{
 				Uint32 aal = le32_to_cpu(eahd->appAttrLocation);
 				memmove(&ea[offset - aal + size],
 					&ea[aal], offset - aal);
 				offset -= aal;
 				eahd->appAttrLocation = cpu_to_le32(aal + size);
 			}
 		}
 		/* rewrite CRC + checksum of eahd */
 		UDF_I_LENEATTR(inode) += size;
 		return (struct GenericAttrFormat *)&ea[offset];
 	}
 	if (loc & 0x02)
 	{
 	}
 	udf_release_data(*bh);
 	return NULL;
 }

 extern struct GenericAttrFormat *
 udf_get_extendedattr(struct inode * inode, Uint32 type, Uint8 subtype,
 	struct buffer_head **bh)
 {
 	struct GenericAttrFormat *gaf;
 	Uint8 *ea = NULL;
 	long_ad eaicb;
 	Uint32 offset;

 	*bh = udf_tread(inode->i_sb, inode->i_ino);

 	if (UDF_I_EXTENDED_FE(inode) == 0)
 	{
 		struct FileEntry *fe;

 		fe = (struct FileEntry *)(*bh)->b_data;
 		eaicb = lela_to_cpu(fe->extendedAttrICB);
 		if (UDF_I_LENEATTR(inode))
 			ea = fe->extendedAttr;
 	}
 	else
 	{
 		struct ExtendedFileEntry *efe;

 		efe = (struct ExtendedFileEntry *)(*bh)->b_data;
 		eaicb = lela_to_cpu(efe->extendedAttrICB);
 		if (UDF_I_LENEATTR(inode))
 			ea = efe->extendedAttr;
 	}

 	if (UDF_I_LENEATTR(inode))
 	{
 		struct ExtendedAttrHeaderDesc *eahd;
 		eahd = (struct ExtendedAttrHeaderDesc *)ea;

 		/* check checksum/crc */
 		if (le16_to_cpu(eahd->descTag.tagIdent) != TID_EXTENDED_ATTRE_HEADER_DESC ||
 			le32_to_cpu(eahd->descTag.tagLocation) != UDF_I_LOCATION(inode).logicalBlockNum)
 		{
 			udf_release_data(*bh);
 			return NULL;
 		}

 		if (type < 2048)
 			offset = sizeof(struct ExtendedAttrHeaderDesc);
 		else if (type < 65536)
 			offset = le32_to_cpu(eahd->impAttrLocation);
 		else
 			offset = le32_to_cpu(eahd->appAttrLocation);

 		while (offset < UDF_I_LENEATTR(inode))
 		{
 			gaf = (struct GenericAttrFormat *)&ea[offset];
 			if (le32_to_cpu(gaf->attrType) == type && gaf->attrSubtype == subtype)
 				return gaf;
 			else
 				offset += le32_to_cpu(gaf->attrLength);
 		}
 	}

 	udf_release_data(*bh);
 	if (eaicb.extLength)
 	{
 		/* TODO */
 	}
 	return NULL;
 }

 extern struct buffer_head *
 udf_read_untagged(struct super_block *sb, Uint32 block, Uint32 offset)
 {
 	struct buffer_head *bh = NULL;

 	/* Read the block */
 	bh = udf_tread(sb, block+offset);
 	if (!bh)
 	{
 		printk(KERN_ERR "udf: udf_read_untagged(%p,%d,%d) failed\n",
 			sb, block, offset);
 		return NULL;
 	}
 	return bh;
 }

 /*
  * udf_read_tagged
  *
  * PURPOSE
  *	Read the first block of a tagged descriptor.
  *
  * HISTORY
  *	July 1, 1997 - Andrew E. Mileski
  *	Written, tested, and released.
  */
 extern struct buffer_head *
 udf_read_tagged(struct super_block *sb, Uint32 block, Uint32 location, Uint16 *ident)
 {
 	tag *tag_p;
 	struct buffer_head *bh = NULL;
 	register Uint8 checksum;
 	register int i;

 	/* Read the block */
 	if (block == 0xFFFFFFFF)
 		return NULL;

 	bh = udf_tread(sb, block);
 	if (!bh)
 	{
 		udf_debug("block=%d, location=%d: read failed\n", block, location);
 		return NULL;
 	}

 	tag_p = (tag *)(bh->b_data);

 	*ident = le16_to_cpu(tag_p->tagIdent);

 	if ( location != le32_to_cpu(tag_p->tagLocation) )
 	{
 		udf_debug("location mismatch block %u, tag %u != %u\n",
 			block, le32_to_cpu(tag_p->tagLocation), location);
 		goto error_out;
 	}

 	/* Verify the tag checksum */
 	checksum = 0U;
 	for (i = 0; i < 4; i++)
 		checksum += (Uint8)(bh->b_data[i]);
 	for (i = 5; i < 16; i++)
 		checksum += (Uint8)(bh->b_data[i]);
 	if (checksum != tag_p->tagChecksum) {
 		printk(KERN_ERR "udf: tag checksum failed block %d\n", block);
 		goto error_out;
 	}

 	/* Verify the tag version */
 	if (le16_to_cpu(tag_p->descVersion) != 0x0002U &&
 		le16_to_cpu(tag_p->descVersion) != 0x0003U)
 	{
 		udf_debug("tag version 0x%04x != 0x0002 || 0x0003 block %d\n",
 			le16_to_cpu(tag_p->descVersion), block);
 		goto error_out;
 	}

 	/* Verify the descriptor CRC */
 	if (le16_to_cpu(tag_p->descCRCLength) + sizeof(tag) > sb->s_blocksize ||
 		le16_to_cpu(tag_p->descCRC) == udf_crc(bh->b_data + sizeof(tag),
 			le16_to_cpu(tag_p->descCRCLength), 0))
 	{
 		return bh;
 	}
 	udf_debug("Crc failure block %d: crc = %d, crclen = %d\n",
 		block, le16_to_cpu(tag_p->descCRC), le16_to_cpu(tag_p->descCRCLength));

 error_out:
 	brelse(bh);
 	return NULL;
 }

 extern struct buffer_head *
 udf_read_ptagged(struct super_block *sb, lb_addr loc, Uint32 offset, Uint16 *ident)
 {
 	return udf_read_tagged(sb, udf_get_lb_pblock(sb, loc, offset),
 		loc.logicalBlockNum + offset, ident);
 }

 void udf_release_data(struct buffer_head *bh)
 {
 	if (bh)
 		brelse(bh);
 }

 #endif

 void udf_update_tag(char *data, int length)
 {
 	tag *tptr = (tag *)data;
 	int i;

 	length -= sizeof(tag);

 	tptr->tagChecksum = 0;
 	tptr->descCRCLength = le16_to_cpu(length);
 	tptr->descCRC = le16_to_cpu(udf_crc(data + sizeof(tag), length, 0));

 	for (i=0; i<16; i++)
 		if (i != 4)
 			tptr->tagChecksum += (Uint8)(data[i]);
 }

 void udf_new_tag(char *data, Uint16 ident, Uint16 version, Uint16 snum,
 	Uint32 loc, int length)
 {
 	tag *tptr = (tag *)data;
 	tptr->tagIdent = le16_to_cpu(ident);
 	tptr->descVersion = le16_to_cpu(version);
 	tptr->tagSerialNum = le16_to_cpu(snum);
 	tptr->tagLocation = le32_to_cpu(loc);
 	udf_update_tag(data, length);
 }

 #ifndef __KERNEL__
 /*
  * udf_read_tagged_data
  *
  * PURPOSE
  *	Read the first block of a tagged descriptor.
  *	Usable from user-land.
  *
  * HISTORY
  *	  10/4/98 dgb: written
  */
 int
 udf_read_tagged_data(char *buffer, int size, int fd, int block, int offset)
 {
 	tag *tag_p;
 	register Uint8 checksum;
 	register int i;
 	unsigned long offs;

 	if (!buffer)
 	{
 		udf_errno = 1;
 		return -1;
 	}

 	if ( !udf_blocksize )
 	{
 		udf_errno = 2;
 		return -1;
 	}

 	if ( size < udf_blocksize )
 	{
 		udf_errno = 3;
 		return -1;
 	}
 	udf_errno = 0;

 	offs = (long)block * udf_blocksize;
 	if ( lseek(fd, offs, SEEK_SET) != offs )
 	{
 		udf_errno = 4;
 		return -1;
 	}

 	i = read(fd, buffer, udf_blocksize);
 	if ( i < udf_blocksize )
 	{
 		udf_errno = 5;
 		return -1;
 	}

 	tag_p = (tag *)(buffer);

 	/* Verify the tag location */
 	if ((block-offset) != tag_p->tagLocation)
 	{
 #ifdef __KERNEL__
 		printk(KERN_ERR "udf: location mismatch block %d, tag %d\n",
 			block, tag_p->tagLocation);
 #else
 		udf_errno = 6;
 #endif
 		goto error_out;
 	}

 	/* Verify the tag checksum */
 	checksum = 0U;
 	for (i = 0; i < 4; i++)
 		checksum += (Uint8)(buffer[i]);
 	for (i = 5; i < 16; i++)
 		checksum += (Uint8)(buffer[i]);
 	if (checksum != tag_p->tagChecksum)
 	{
 #ifdef __KERNEL__
 		printk(KERN_ERR "udf: tag checksum failed\n");
 #else
 		udf_errno = 7;
 #endif
 		goto error_out;
 	}

 	/* Verify the tag version */
 	if (tag_p->descVersion != 0x0002U)
 	{
 #ifdef __KERNEL__
 		printk(KERN_ERR "udf: tag version 0x%04x != 0x0002U\n",
 			tag_p->descVersion);
 #else
 		udf_errno = 8;
 #endif
 		goto error_out;
 	}

 	/* Verify the descriptor CRC */
 	if (tag_p->descCRC == udf_crc(buffer + 16, tag_p->descCRCLength, 0))
 	{
 		udf_errno = 0;
 		return 0;
 	}
 #ifdef __KERNEL__
 	printk(KERN_ERR "udf: crc failure in udf_read_tagged\n");
 #else
 	udf_errno = 9;
 #endif

 error_out:
 	return -1;
 }
 #endif
	/*
	* misc.c
	*
	* PURPOSE
	* Miscellaneous routines for the OSTA-UDF(tm) filesystem.
	*
	* CONTACTS
	* E-mail regarding any portion of the Linux UDF file system should be
	* directed to the development team mailing list (run by majordomo):
	* linux_udf@hpesjro.fc.hp.com
	*
	* COPYRIGHT
	* This file is distributed under the terms of the GNU General Public
	* License (GPL). Copies of the GPL can be obtained from:
	* ftp://prep.ai.mit.edu/pub/gnu/GPL
	* Each contributing author retains all rights to their own work.
	*
	* (C) 1998 Dave Boynton
	* (C) 1998-2000 Ben Fennema
	* (C) 1999-2000 Stelias Computing Inc
	*
	* HISTORY
	*
	* 04/19/99 blf partial support for reading/writing specific EA's
	*/

	#include "udfdecl.h"

	#if defined(__linux__) && defined(__KERNEL__)

	#include "udf_sb.h"
	#include "udf_i.h"

	#include <linux/fs.h>
	#include <linux/string.h>
	#include <linux/udf_fs.h>

	#else

	#include <sys/types.h>
	#include <stdio.h>
	#include <unistd.h>
	#include <string.h>

	int udf_blocksize=0;
	int udf_errno=0;

	void
	udf_setblocksize(int size)
	{
	udf_blocksize=size;
	}
	#endif

	Uint32
	udf64_low32(Uint64 indat)
	{
	return indat & 0x00000000FFFFFFFFULL;
	}

	Uint32
	udf64_high32(Uint64 indat)
	{
	return indat >> 32;
	}

	#if defined(__linux__) && defined(__KERNEL__)

	extern struct buffer_head *
	udf_tgetblk(struct super_block *sb, int block)
	{
	if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV))
	return sb_getblk(sb, udf_fixed_to_variable(block));
	else
	return sb_getblk(sb, block);
	}

	extern struct buffer_head *
	udf_tread(struct super_block *sb, int block)
	{
	if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV))
	return sb_bread(sb, udf_fixed_to_variable(block));
	else
	return sb_bread(sb, block);
	}

	extern struct GenericAttrFormat *
	udf_add_extendedattr(struct inode * inode, Uint32 size, Uint32 type,
	Uint8 loc, struct buffer_head **bh)
	{
	Uint8 ea = NULL, ad = NULL;
	long_ad eaicb;
	int offset;

	*bh = udf_tread(inode->i_sb, inode->i_ino);

	if (UDF_I_EXTENDED_FE(inode) == 0)
	{
	struct FileEntry *fe;

	fe = (struct FileEntry )(bh)->b_data;
	eaicb = lela_to_cpu(fe->extendedAttrICB);
	offset = sizeof(struct FileEntry);
	}
	else
	{
	struct ExtendedFileEntry *efe;

	efe = (struct ExtendedFileEntry )(bh)->b_data;
	eaicb = lela_to_cpu(efe->extendedAttrICB);
	offset = sizeof(struct ExtendedFileEntry);
	}

	ea = &(*bh)->b_data[offset];
	if (UDF_I_LENEATTR(inode))
	offset += UDF_I_LENEATTR(inode);
	else
	size += sizeof(struct ExtendedAttrHeaderDesc);

	ad = &(*bh)->b_data[offset];
	if (UDF_I_LENALLOC(inode))
	offset += UDF_I_LENALLOC(inode);

	offset = inode->i_sb->s_blocksize - offset;

	/* TODO - Check for FreeEASpace */

	if (loc & 0x01 && offset >= size)
	{
	struct ExtendedAttrHeaderDesc *eahd;
	eahd = (struct ExtendedAttrHeaderDesc *)ea;

	if (UDF_I_LENALLOC(inode))
	{
	memmove(&ad[size], ad, UDF_I_LENALLOC(inode));
	}

	if (UDF_I_LENEATTR(inode))
	{
	/* check checksum/crc */
	if (le16_to_cpu(eahd->descTag.tagIdent) != TID_EXTENDED_ATTRE_HEADER_DESC \|\|
	le32_to_cpu(eahd->descTag.tagLocation) != UDF_I_LOCATION(inode).logicalBlockNum)
	{
	udf_release_data(*bh);
	return NULL;
	}
	}
	else
	{
	size -= sizeof(struct ExtendedAttrHeaderDesc);
	UDF_I_LENEATTR(inode) += sizeof(struct ExtendedAttrHeaderDesc);
	eahd->descTag.tagIdent = cpu_to_le16(TID_EXTENDED_ATTRE_HEADER_DESC);
	eahd->descTag.descVersion = cpu_to_le16(2);
	eahd->descTag.tagSerialNum = cpu_to_le16(1);
	eahd->descTag.tagLocation = cpu_to_le32(UDF_I_LOCATION(inode).logicalBlockNum);
	eahd->impAttrLocation = cpu_to_le32(0xFFFFFFFF);
	eahd->appAttrLocation = cpu_to_le32(0xFFFFFFFF);
	}

	offset = UDF_I_LENEATTR(inode);
	if (type < 2048)
	{
	if (le32_to_cpu(eahd->appAttrLocation) < UDF_I_LENEATTR(inode))
	{
	Uint32 aal = le32_to_cpu(eahd->appAttrLocation);
	memmove(&ea[offset - aal + size],
	&ea[aal], offset - aal);
	offset -= aal;
	eahd->appAttrLocation = cpu_to_le32(aal + size);
	}
	if (le32_to_cpu(eahd->impAttrLocation) < UDF_I_LENEATTR(inode))
	{
	Uint32 ial = le32_to_cpu(eahd->impAttrLocation);
	memmove(&ea[offset - ial + size],
	&ea[ial], offset - ial);
	offset -= ial;
	eahd->impAttrLocation = cpu_to_le32(ial + size);
	}
	}
	else if (type < 65536)
	{
	if (le32_to_cpu(eahd->appAttrLocation) < UDF_I_LENEATTR(inode))
	{
	Uint32 aal = le32_to_cpu(eahd->appAttrLocation);
	memmove(&ea[offset - aal + size],
	&ea[aal], offset - aal);
	offset -= aal;
	eahd->appAttrLocation = cpu_to_le32(aal + size);
	}
	}
	/* rewrite CRC + checksum of eahd */
	UDF_I_LENEATTR(inode) += size;
	return (struct GenericAttrFormat *)&ea[offset];
	}
	if (loc & 0x02)
	{
	}
	udf_release_data(*bh);
	return NULL;
	}

	extern struct GenericAttrFormat *
	udf_get_extendedattr(struct inode * inode, Uint32 type, Uint8 subtype,
	struct buffer_head **bh)
	{
	struct GenericAttrFormat *gaf;
	Uint8 *ea = NULL;
	long_ad eaicb;
	Uint32 offset;

	*bh = udf_tread(inode->i_sb, inode->i_ino);

	if (UDF_I_EXTENDED_FE(inode) == 0)
	{
	struct FileEntry *fe;

	fe = (struct FileEntry )(bh)->b_data;
	eaicb = lela_to_cpu(fe->extendedAttrICB);
	if (UDF_I_LENEATTR(inode))
	ea = fe->extendedAttr;
	}
	else
	{
	struct ExtendedFileEntry *efe;

	efe = (struct ExtendedFileEntry )(bh)->b_data;
	eaicb = lela_to_cpu(efe->extendedAttrICB);
	if (UDF_I_LENEATTR(inode))
	ea = efe->extendedAttr;
	}

	if (UDF_I_LENEATTR(inode))
	{
	struct ExtendedAttrHeaderDesc *eahd;
	eahd = (struct ExtendedAttrHeaderDesc *)ea;

	/* check checksum/crc */
	if (le16_to_cpu(eahd->descTag.tagIdent) != TID_EXTENDED_ATTRE_HEADER_DESC \|\|
	le32_to_cpu(eahd->descTag.tagLocation) != UDF_I_LOCATION(inode).logicalBlockNum)
	{
	udf_release_data(*bh);
	return NULL;
	}

	if (type < 2048)
	offset = sizeof(struct ExtendedAttrHeaderDesc);
	else if (type < 65536)
	offset = le32_to_cpu(eahd->impAttrLocation);
	else
	offset = le32_to_cpu(eahd->appAttrLocation);

	while (offset < UDF_I_LENEATTR(inode))
	{
	gaf = (struct GenericAttrFormat *)&ea[offset];
	if (le32_to_cpu(gaf->attrType) == type && gaf->attrSubtype == subtype)
	return gaf;
	else
	offset += le32_to_cpu(gaf->attrLength);
	}
	}

	udf_release_data(*bh);
	if (eaicb.extLength)
	{
	/* TODO */
	}
	return NULL;
	}

	extern struct buffer_head *
	udf_read_untagged(struct super_block *sb, Uint32 block, Uint32 offset)
	{
	struct buffer_head *bh = NULL;

	/* Read the block */
	bh = udf_tread(sb, block+offset);
	if (!bh)
	{
	printk(KERN_ERR "udf: udf_read_untagged(%p,%d,%d) failed\n",
	sb, block, offset);
	return NULL;
	}
	return bh;
	}

	/*
	* udf_read_tagged
	*
	* PURPOSE
	* Read the first block of a tagged descriptor.
	*
	* HISTORY
	* July 1, 1997 - Andrew E. Mileski
	* Written, tested, and released.
	*/
	extern struct buffer_head *
	udf_read_tagged(struct super_block sb, Uint32 block, Uint32 location, Uint16 ident)
	{
	tag *tag_p;
	struct buffer_head *bh = NULL;
	register Uint8 checksum;
	register int i;

	/* Read the block */
	if (block == 0xFFFFFFFF)
	return NULL;

	bh = udf_tread(sb, block);
	if (!bh)
	{
	udf_debug("block=%d, location=%d: read failed\n", block, location);
	return NULL;
	}

	tag_p = (tag *)(bh->b_data);

	*ident = le16_to_cpu(tag_p->tagIdent);

	if ( location != le32_to_cpu(tag_p->tagLocation) )
	{
	udf_debug("location mismatch block %u, tag %u != %u\n",
	block, le32_to_cpu(tag_p->tagLocation), location);
	goto error_out;
	}

	/* Verify the tag checksum */
	checksum = 0U;
	for (i = 0; i < 4; i++)
	checksum += (Uint8)(bh->b_data[i]);
	for (i = 5; i < 16; i++)
	checksum += (Uint8)(bh->b_data[i]);
	if (checksum != tag_p->tagChecksum) {
	printk(KERN_ERR "udf: tag checksum failed block %d\n", block);
	goto error_out;
	}

	/* Verify the tag version */
	if (le16_to_cpu(tag_p->descVersion) != 0x0002U &&
	le16_to_cpu(tag_p->descVersion) != 0x0003U)
	{
	udf_debug("tag version 0x%04x != 0x0002 \|\| 0x0003 block %d\n",
	le16_to_cpu(tag_p->descVersion), block);
	goto error_out;
	}

	/* Verify the descriptor CRC */
	if (le16_to_cpu(tag_p->descCRCLength) + sizeof(tag) > sb->s_blocksize \|\|
	le16_to_cpu(tag_p->descCRC) == udf_crc(bh->b_data + sizeof(tag),
	le16_to_cpu(tag_p->descCRCLength), 0))
	{
	return bh;
	}
	udf_debug("Crc failure block %d: crc = %d, crclen = %d\n",
	block, le16_to_cpu(tag_p->descCRC), le16_to_cpu(tag_p->descCRCLength));

	error_out:
	brelse(bh);
	return NULL;
	}

	extern struct buffer_head *
	udf_read_ptagged(struct super_block sb, lb_addr loc, Uint32 offset, Uint16 ident)
	{
	return udf_read_tagged(sb, udf_get_lb_pblock(sb, loc, offset),
	loc.logicalBlockNum + offset, ident);
	}

	void udf_release_data(struct buffer_head *bh)
	{
	if (bh)
	brelse(bh);
	}

	#endif

	void udf_update_tag(char *data, int length)
	{
	tag tptr = (tag )data;
	int i;

	length -= sizeof(tag);

	tptr->tagChecksum = 0;
	tptr->descCRCLength = le16_to_cpu(length);
	tptr->descCRC = le16_to_cpu(udf_crc(data + sizeof(tag), length, 0));

	for (i=0; i<16; i++)
	if (i != 4)
	tptr->tagChecksum += (Uint8)(data[i]);
	}

	void udf_new_tag(char *data, Uint16 ident, Uint16 version, Uint16 snum,
	Uint32 loc, int length)
	{
	tag tptr = (tag )data;
	tptr->tagIdent = le16_to_cpu(ident);
	tptr->descVersion = le16_to_cpu(version);
	tptr->tagSerialNum = le16_to_cpu(snum);
	tptr->tagLocation = le32_to_cpu(loc);
	udf_update_tag(data, length);
	}

	#ifndef __KERNEL__
	/*
	* udf_read_tagged_data
	*
	* PURPOSE
	* Read the first block of a tagged descriptor.
	* Usable from user-land.
	*
	* HISTORY
	* 10/4/98 dgb: written
	*/
	int
	udf_read_tagged_data(char *buffer, int size, int fd, int block, int offset)
	{
	tag *tag_p;
	register Uint8 checksum;
	register int i;
	unsigned long offs;

	if (!buffer)
	{
	udf_errno = 1;
	return -1;
	}

	if ( !udf_blocksize )
	{
	udf_errno = 2;
	return -1;
	}

	if ( size < udf_blocksize )
	{
	udf_errno = 3;
	return -1;
	}
	udf_errno = 0;

	offs = (long)block * udf_blocksize;
	if ( lseek(fd, offs, SEEK_SET) != offs )
	{
	udf_errno = 4;
	return -1;
	}

	i = read(fd, buffer, udf_blocksize);
	if ( i < udf_blocksize )
	{
	udf_errno = 5;
	return -1;
	}

	tag_p = (tag *)(buffer);

	/* Verify the tag location */
	if ((block-offset) != tag_p->tagLocation)
	{
	#ifdef __KERNEL__
	printk(KERN_ERR "udf: location mismatch block %d, tag %d\n",
	block, tag_p->tagLocation);
	#else
	udf_errno = 6;
	#endif
	goto error_out;
	}

	/* Verify the tag checksum */
	checksum = 0U;
	for (i = 0; i < 4; i++)
	checksum += (Uint8)(buffer[i]);
	for (i = 5; i < 16; i++)
	checksum += (Uint8)(buffer[i]);
	if (checksum != tag_p->tagChecksum)
	{
	#ifdef __KERNEL__
	printk(KERN_ERR "udf: tag checksum failed\n");
	#else
	udf_errno = 7;
	#endif
	goto error_out;
	}

	/* Verify the tag version */
	if (tag_p->descVersion != 0x0002U)
	{
	#ifdef __KERNEL__
	printk(KERN_ERR "udf: tag version 0x%04x != 0x0002U\n",
	tag_p->descVersion);
	#else
	udf_errno = 8;
	#endif
	goto error_out;
	}

	/* Verify the descriptor CRC */
	if (tag_p->descCRC == udf_crc(buffer + 16, tag_p->descCRCLength, 0))
	{
	udf_errno = 0;
	return 0;
	}
	#ifdef __KERNEL__
	printk(KERN_ERR "udf: crc failure in udf_read_tagged\n");
	#else
	udf_errno = 9;
	#endif

	error_out:
	return -1;
	}
	#endif