super.c

这是Linux系统下的对UDF文件系统新增的功能

		if (UDF_MAX_WRITE_VERSION > le16_to_cpu(UDF_SB_LVIDIU(sb)->maxUDFWriteRev))
			UDF_SB_LVIDIU(sb)->maxUDFWriteRev = cpu_to_le16(UDF_MAX_WRITE_VERSION);
		if (UDF_SB_UDFREV(sb) > le16_to_cpu(UDF_SB_LVIDIU(sb)->minUDFReadRev))
			UDF_SB_LVIDIU(sb)->minUDFReadRev = cpu_to_le16(UDF_SB_UDFREV(sb));
		if (UDF_SB_UDFREV(sb) > le16_to_cpu(UDF_SB_LVIDIU(sb)->minUDFWriteRev))
			UDF_SB_LVIDIU(sb)->minUDFWriteRev = cpu_to_le16(UDF_SB_UDFREV(sb));
		UDF_SB_LVID(sb)->integrityType = LVID_INTEGRITY_TYPE_CLOSE;

		UDF_SB_LVID(sb)->descTag.descCRC =
			cpu_to_le16(udf_crc((char *)UDF_SB_LVID(sb) + sizeof(tag),
			le16_to_cpu(UDF_SB_LVID(sb)->descTag.descCRCLength), 0));

		UDF_SB_LVID(sb)->descTag.tagChecksum = 0;
		for (i=0; i<16; i++)
			if (i != 4)
				UDF_SB_LVID(sb)->descTag.tagChecksum +=
					((uint8_t *)&(UDF_SB_LVID(sb)->descTag))[i];

		mark_buffer_dirty(UDF_SB_LVIDBH(sb));
	}
}

/*
 * udf_read_super
 *
 * PURPOSE
 *	Complete the specified super block.
 *
 * PRE-CONDITIONS
 *	sb			Pointer to superblock to complete - never NULL.
 *	sb->s_dev		Device to read suberblock from.
 *	options			Pointer to mount options.
 *	silent			Silent flag.
 *
 * HISTORY
 *	July 1, 1997 - Andrew E. Mileski
 *	Written, tested, and released.
 */
static int udf_fill_super(struct super_block *sb, void *options, int silent)
{
	int i;
	struct inode *inode=NULL;
	struct udf_options uopt;
	lb_addr rootdir, fileset;
	struct udf_sb_info *sbi;

	uopt.flags = (1 << UDF_FLAG_USE_AD_IN_ICB) | (1 << UDF_FLAG_STRICT);
	uopt.uid = -1;
	uopt.gid = -1;
	uopt.umask = 0;

	sbi = kmalloc(sizeof(struct udf_sb_info), GFP_KERNEL);
	if (!sbi)
		return -ENOMEM;
	sb->s_fs_info = sbi;
	memset(UDF_SB(sb), 0x00, sizeof(struct udf_sb_info));

	if (!udf_parse_options((char *)options, &uopt))
		goto error_out;

	if (uopt.flags & (1 << UDF_FLAG_UTF8) &&
	    uopt.flags & (1 << UDF_FLAG_NLS_MAP))
	{
		udf_error(sb, "udf_read_super",
			"utf8 cannot be combined with iocharset\n");
		goto error_out;
	}
#if defined(CONFIG_NLS) || defined(CONFIG_NLS_MODULE)
	if ((uopt.flags & (1 << UDF_FLAG_NLS_MAP)) && !uopt.nls_map)
	{
		uopt.nls_map = load_nls_default();
		if (!uopt.nls_map)
			uopt.flags &= ~(1 << UDF_FLAG_NLS_MAP);
		else
			udf_debug("Using default NLS map\n");
	}
#endif
	if (!(uopt.flags & (1 << UDF_FLAG_NLS_MAP)))
		uopt.flags |= (1 << UDF_FLAG_UTF8);

	fileset.logicalBlockNum = 0xFFFFFFFF;
	fileset.partitionReferenceNum = 0xFFFF;

	UDF_SB(sb)->s_flags = uopt.flags;
	UDF_SB(sb)->s_uid = uopt.uid;
	UDF_SB(sb)->s_gid = uopt.gid;
	UDF_SB(sb)->s_umask = uopt.umask;
	UDF_SB(sb)->s_nls_map = uopt.nls_map;

	/* Set the block size for all transfers */
	if (!udf_set_blocksize(sb, uopt.blocksize))
		goto error_out;

	if ( uopt.session == 0xFFFFFFFF )
		UDF_SB_SESSION(sb) = udf_get_last_session(sb);
	else
		UDF_SB_SESSION(sb) = uopt.session;

	udf_debug("Multi-session=%d\n", UDF_SB_SESSION(sb));

	UDF_SB_LASTBLOCK(sb) = uopt.lastblock;
	UDF_SB_ANCHOR(sb)[0] = UDF_SB_ANCHOR(sb)[1] = 0;
	UDF_SB_ANCHOR(sb)[2] = uopt.anchor;
	UDF_SB_ANCHOR(sb)[3] = 256;

	if (udf_check_valid(sb, uopt.novrs, silent)) /* read volume recognition sequences */
	{
		printk("UDF-fs: No VRS found\n");
 		goto error_out;
	}

	udf_find_anchor(sb);

	/* Fill in the rest of the superblock */
	sb->s_op = &udf_sb_ops;
	sb->dq_op = NULL;
	sb->s_dirt = 0;
	sb->s_magic = UDF_SUPER_MAGIC;

	if (udf_load_partition(sb, &fileset))
	{
		printk("UDF-fs: No partition found (1)\n");
		goto error_out;
	}

	udf_debug("Lastblock=%d\n", UDF_SB_LASTBLOCK(sb));

	if ( UDF_SB_LVIDBH(sb) )
	{
		uint16_t minUDFReadRev = le16_to_cpu(UDF_SB_LVIDIU(sb)->minUDFReadRev);
		uint16_t minUDFWriteRev = le16_to_cpu(UDF_SB_LVIDIU(sb)->minUDFWriteRev);
		/* uint16_t maxUDFWriteRev = le16_to_cpu(UDF_SB_LVIDIU(sb)->maxUDFWriteRev); */

		if (minUDFReadRev > UDF_MAX_READ_VERSION)
		{
			printk("UDF-fs: minUDFReadRev=%x (max is %x)\n",
				UDF_SB_LVIDIU(sb)->minUDFReadRev, UDF_MAX_READ_VERSION);
			goto error_out;
		}
		else if (minUDFWriteRev > UDF_MAX_WRITE_VERSION)
		{
			sb->s_flags |= MS_RDONLY;
		}

		UDF_SB_UDFREV(sb) = minUDFWriteRev;

		if (minUDFReadRev >= UDF_VERS_USE_EXTENDED_FE)
			UDF_SET_FLAG(sb, UDF_FLAG_USE_EXTENDED_FE);
		if (minUDFReadRev >= UDF_VERS_USE_STREAMS)
			UDF_SET_FLAG(sb, UDF_FLAG_USE_STREAMS);
	}

	if ( !UDF_SB_NUMPARTS(sb) )
	{
		printk("UDF-fs: No partition found (2)\n");
		goto error_out;
	}

	if ( udf_find_fileset(sb, &fileset, &rootdir) )
	{
		printk("UDF-fs: No fileset found\n");
		goto error_out;
	}

	if (!silent)
	{
		timestamp ts;
		udf_time_to_stamp(&ts, UDF_SB_RECORDTIME(sb));
		udf_info("UDF %s (%s) Mounting volume '%s', timestamp %04u/%02u/%02u %02u:%02u (%x)\n",
			UDFFS_VERSION, UDFFS_DATE,
			UDF_SB_VOLIDENT(sb), ts.year, ts.month, ts.day, ts.hour, ts.minute,
			ts.typeAndTimezone);
	}
	if (!(sb->s_flags & MS_RDONLY))
		udf_open_lvid(sb);

	/* Assign the root inode */
	/* assign inodes by physical block number */
	/* perhaps it's not extensible enough, but for now ... */
	inode = udf_iget(sb, rootdir); 
	if (!inode)
	{
		printk("UDF-fs: Error in udf_iget, block=%d, partition=%d\n",
			rootdir.logicalBlockNum, rootdir.partitionReferenceNum);
		goto error_out;
	}

	/* Allocate a dentry for the root inode */
	sb->s_root = d_alloc_root(inode);
	if (!sb->s_root)
	{
		printk("UDF-fs: Couldn't allocate root dentry\n");
		iput(inode);
		goto error_out;
	}
	sb->s_maxbytes = MAX_LFS_FILESIZE;
	return 0;

error_out:
	if (UDF_SB_VAT(sb))
		iput(UDF_SB_VAT(sb));
	if (UDF_SB_NUMPARTS(sb))
	{
		if (UDF_SB_PARTFLAGS(sb, UDF_SB_PARTITION(sb)) & UDF_PART_FLAG_UNALLOC_TABLE)
			iput(UDF_SB_PARTMAPS(sb)[UDF_SB_PARTITION(sb)].s_uspace.s_table);
		if (UDF_SB_PARTFLAGS(sb, UDF_SB_PARTITION(sb)) & UDF_PART_FLAG_FREED_TABLE)
			iput(UDF_SB_PARTMAPS(sb)[UDF_SB_PARTITION(sb)].s_fspace.s_table);
		if (UDF_SB_PARTFLAGS(sb, UDF_SB_PARTITION(sb)) & UDF_PART_FLAG_UNALLOC_BITMAP)
			UDF_SB_FREE_BITMAP(sb,UDF_SB_PARTITION(sb),s_uspace);
		if (UDF_SB_PARTFLAGS(sb, UDF_SB_PARTITION(sb)) & UDF_PART_FLAG_FREED_BITMAP)
			UDF_SB_FREE_BITMAP(sb,UDF_SB_PARTITION(sb),s_fspace);
		if (UDF_SB_PARTTYPE(sb, UDF_SB_PARTITION(sb)) == UDF_SPARABLE_MAP15)
		{
			for (i=0; i<4; i++)
				udf_release_data(UDF_SB_TYPESPAR(sb, UDF_SB_PARTITION(sb)).s_spar_map[i]);
		}
	}
#if defined(CONFIG_NLS) || defined(CONFIG_NLS_MODULE)
	if (UDF_QUERY_FLAG(sb, UDF_FLAG_NLS_MAP))
		unload_nls(UDF_SB(sb)->s_nls_map);
#endif
	if (!(sb->s_flags & MS_RDONLY))
		udf_close_lvid(sb);
	udf_release_data(UDF_SB_LVIDBH(sb));
	UDF_SB_FREE(sb);
	kfree(sbi);
	sb->s_fs_info = NULL;
	return -EINVAL;
}

void udf_error(struct super_block *sb, const char *function,
	const char *fmt, ...)
{
	va_list args;

	if (!(sb->s_flags & MS_RDONLY))
	{
		/* mark sb error */
		sb->s_dirt = 1;
	}
	va_start(args, fmt);
	vsprintf(error_buf, fmt, args);
	va_end(args);
	printk (KERN_CRIT "UDF-fs error (device %s): %s: %s\n",
		sb->s_id, function, error_buf);
}

void udf_warning(struct super_block *sb, const char *function,
	const char *fmt, ...)
{
	va_list args;

	va_start (args, fmt);
	vsprintf(error_buf, fmt, args);
	va_end(args);
	printk(KERN_WARNING "UDF-fs warning (device %s): %s: %s\n",
		sb->s_id, function, error_buf);
}

/*
 * udf_put_super
 *
 * PURPOSE
 *	Prepare for destruction of the superblock.
 *
 * DESCRIPTION
 *	Called before the filesystem is unmounted.
 *
 * HISTORY
 *	July 1, 1997 - Andrew E. Mileski
 *	Written, tested, and released.
 */
static void
udf_put_super(struct super_block *sb)
{
	int i;

	if (UDF_SB_VAT(sb))
		iput(UDF_SB_VAT(sb));
	if (UDF_SB_NUMPARTS(sb))
	{
		if (UDF_SB_PARTFLAGS(sb, UDF_SB_PARTITION(sb)) & UDF_PART_FLAG_UNALLOC_TABLE)
			iput(UDF_SB_PARTMAPS(sb)[UDF_SB_PARTITION(sb)].s_uspace.s_table);
		if (UDF_SB_PARTFLAGS(sb, UDF_SB_PARTITION(sb)) & UDF_PART_FLAG_FREED_TABLE)
			iput(UDF_SB_PARTMAPS(sb)[UDF_SB_PARTITION(sb)].s_fspace.s_table);
		if (UDF_SB_PARTFLAGS(sb, UDF_SB_PARTITION(sb)) & UDF_PART_FLAG_UNALLOC_BITMAP)
			UDF_SB_FREE_BITMAP(sb,UDF_SB_PARTITION(sb),s_uspace);
		if (UDF_SB_PARTFLAGS(sb, UDF_SB_PARTITION(sb)) & UDF_PART_FLAG_FREED_BITMAP)
			UDF_SB_FREE_BITMAP(sb,UDF_SB_PARTITION(sb),s_fspace);
		if (UDF_SB_PARTTYPE(sb, UDF_SB_PARTITION(sb)) == UDF_SPARABLE_MAP15)
		{
			for (i=0; i<4; i++)
				udf_release_data(UDF_SB_TYPESPAR(sb, UDF_SB_PARTITION(sb)).s_spar_map[i]);
		}
	}
#if defined(CONFIG_NLS) || defined(CONFIG_NLS_MODULE)
	if (UDF_QUERY_FLAG(sb, UDF_FLAG_NLS_MAP))
		unload_nls(UDF_SB(sb)->s_nls_map);
#endif
	if (!(sb->s_flags & MS_RDONLY))
		udf_close_lvid(sb);
	udf_release_data(UDF_SB_LVIDBH(sb));
	UDF_SB_FREE(sb);
	kfree(sb->s_fs_info);
	sb->s_fs_info = NULL;
}

/*
 * udf_stat_fs
 *
 * PURPOSE
 *	Return info about the filesystem.
 *
 * DESCRIPTION
 *	Called by sys_statfs()
 *
 * HISTORY
 *	July 1, 1997 - Andrew E. Mileski
 *	Written, tested, and released.
 */
static int
udf_statfs(struct super_block *sb, struct kstatfs *buf)
{
	buf->f_type = UDF_SUPER_MAGIC;
	buf->f_bsize = sb->s_blocksize;
	buf->f_blocks = UDF_SB_PARTLEN(sb, UDF_SB_PARTITION(sb));
	buf->f_bfree = udf_count_free(sb);
	buf->f_bavail = buf->f_bfree;
	buf->f_files = (UDF_SB_LVIDBH(sb) ?
		(le32_to_cpu(UDF_SB_LVIDIU(sb)->numFiles) +
		le32_to_cpu(UDF_SB_LVIDIU(sb)->numDirs)) : 0) + buf->f_bfree;
	buf->f_ffree = buf->f_bfree;
	/* __kernel_fsid_t f_fsid */
	buf->f_namelen = UDF_NAME_LEN-2;

	return 0;
}

static unsigned char udf_bitmap_lookup[16] = {
	0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4
};

static unsigned int
udf_count_free_bitmap(struct super_block *sb, struct udf_bitmap *bitmap)
{
	struct buffer_head *bh = NULL;
	unsigned int accum = 0;
	int index;
	int block = 0, newblock;
	lb_addr loc;
	uint32_t bytes;
	uint8_t value;
	uint8_t *ptr;
	uint16_t ident;
	struct spaceBitmapDesc *bm;

	lock_kernel();

	loc.logicalBlockNum = bitmap->s_extPosition;
	loc.partitionReferenceNum = UDF_SB_PARTITION(sb);
	bh = udf_read_ptagged(sb, loc, 0, &ident);

	if (!bh)
	{
		printk(KERN_ERR "udf: udf_count_free failed\n");
		goto out;
	}
	else if (ident != TAG_IDENT_SBD)
	{
		udf_release_data(bh);
		printk(KERN_ERR "udf: udf_count_free failed\n");
		goto out;
	}

	bm = (struct spaceBitmapDesc *)bh->b_data;
	bytes = bm->numOfBytes;
	index = sizeof(struct spaceBitmapDesc); /* offset in first block only */
	ptr = (uint8_t *)bh->b_data;

	while ( bytes > 0 )
	{
		while ((bytes > 0) && (index < sb->s_blocksize))
		{
			value = ptr[index];
			accum += udf_bitmap_lookup[ value & 0x0f ];
			accum += udf_bitmap_lookup[ value >> 4 ];
			index++;
			bytes--;
		}
		if ( bytes )
		{
			udf_release_data(bh);
			newblock = udf_get_lb_pblock(sb, loc, ++block);
			bh = udf_tread(sb, newblock);
			if (!bh)
			{
				udf_debug("read failed\n");
				goto out;
			}
			index = 0;
			ptr = (uint8_t *)bh->b_data;
		}
	}
	udf_release_data(bh);

out:
	unlock_kernel();

	return accum;
}

static unsigned int
udf_count_free_table(struct super_block *sb, struct inode * table)
{
	unsigned int accum = 0;
	uint32_t extoffset, elen;
	lb_addr bloc, eloc;
	int8_t etype;
	struct buffer_head *bh = NULL;

	lock_kernel();

	bloc = UDF_I_LOCATION(table);
	extoffset = sizeof(struct unallocSpaceEntry);

	while ((etype = udf_next_aext(table, &bloc, &extoffset, &eloc, &elen, &bh, 1)) != -1)
	{
		accum += (elen >> table->i_sb->s_blocksize_bits);
	}
	udf_release_data(bh);

	unlock_kernel();

	return accum;
}
	
static unsigned int
udf_count_free(struct super_block *sb)
{
	unsigned int accum = 0;

	if (UDF_SB_LVIDBH(sb))
	{
		if (le32_to_cpu(UDF_SB_LVID(sb)->numOfPartitions) > UDF_SB_PARTITION(sb))
		{
			accum = le32_to_cpu(UDF_SB_LVID(sb)->freeSpaceTable[UDF_SB_PARTITION(sb)]);

			if (accum == 0xFFFFFFFF)
				accum = 0;
		}
	}

	if (accum)
		return accum;

	if (UDF_SB_PARTFLAGS(sb,UDF_SB_PARTITION(sb)) & UDF_PART_FLAG_UNALLOC_BITMAP)
	{
		accum += udf_count_free_bitmap(sb,
			UDF_SB_PARTMAPS(sb)[UDF_SB_PARTITION(sb)].s_uspace.s_bitmap);
	}
	if (UDF_SB_PARTFLAGS(sb,UDF_SB_PARTITION(sb)) & UDF_PART_FLAG_FREED_BITMAP)
	{
		accum += udf_count_free_bitmap(sb,
			UDF_SB_PARTMAPS(sb)[UDF_SB_PARTITION(sb)].s_fspace.s_bitmap);
	}
	if (accum)
		return accum;

	if (UDF_SB_PARTFLAGS(sb,UDF_SB_PARTITION(sb)) & UDF_PART_FLAG_UNALLOC_TABLE)
	{
		accum += udf_count_free_table(sb,
			UDF_SB_PARTMAPS(sb)[UDF_SB_PARTITION(sb)].s_uspace.s_table);
	}
	if (UDF_SB_PARTFLAGS(sb,UDF_SB_PARTITION(sb)) & UDF_PART_FLAG_FREED_TABLE)
	{
		accum += udf_count_free_table(sb,
			UDF_SB_PARTMAPS(sb)[UDF_SB_PARTITION(sb)].s_fspace.s_table);
	}

	return accum;
}