inode.c

这是Linux系统下的对UDF文件系统新增的功能

	udf_release_data(bh);
	return err;
}

/*
 * udf_iget
 *
 * PURPOSE
 *	Get an inode.
 *
 * DESCRIPTION
 *	This routine replaces iget() and read_inode().
 *
 * HISTORY
 *	October 3, 1997 - Andrew E. Mileski
 *	Written, tested, and released.
 *
 * 12/19/98 dgb  Added semaphore and changed to be a wrapper of iget
 */
struct inode *
udf_iget(struct super_block *sb, lb_addr ino)
{
	struct inode *inode;
	unsigned long block;

	block = udf_get_lb_pblock(sb, ino, 0);

	/* Get the inode */

	inode = iget(sb, block);
		/* calls udf_read_inode() ! */

	if (!inode)
	{
		printk(KERN_ERR "udf: iget() failed\n");
		return NULL;
	}
	else if (is_bad_inode(inode))
	{
		iput(inode);
		return NULL;
	}
	else if (UDF_I_LOCATION(inode).logicalBlockNum == 0xFFFFFFFF &&
		UDF_I_LOCATION(inode).partitionReferenceNum == 0xFFFF)
	{
		memcpy(&UDF_I_LOCATION(inode), &ino, sizeof(lb_addr));
		__udf_read_inode(inode);
		if (is_bad_inode(inode))
		{
			iput(inode);
			return NULL;
		}
	}

	if ( ino.logicalBlockNum >= UDF_SB_PARTLEN(sb, ino.partitionReferenceNum) )
	{
		udf_debug("block=%d, partition=%d out of range\n",
			ino.logicalBlockNum, ino.partitionReferenceNum);
		make_bad_inode(inode);
		iput(inode);
		return NULL;
 	}

	return inode;
}

int8_t udf_add_aext(struct inode *inode, lb_addr *bloc, int *extoffset,
	lb_addr eloc, uint32_t elen, struct buffer_head **bh, int inc)
{
	int adsize;
	short_ad *sad = NULL;
	long_ad *lad = NULL;
	struct allocExtDesc *aed;
	int8_t etype;
	uint8_t *ptr;

	if (!*bh)
		ptr = UDF_I_DATA(inode) + *extoffset - udf_file_entry_alloc_offset(inode) + UDF_I_LENEATTR(inode);
	else
		ptr = (*bh)->b_data + *extoffset;

	if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_SHORT)
		adsize = sizeof(short_ad);
	else if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_LONG)
		adsize = sizeof(long_ad);
	else
		return -1;

	if (*extoffset + (2 * adsize) > inode->i_sb->s_blocksize)
	{
		char *sptr, *dptr;
		struct buffer_head *nbh;
		int err, loffset;
		lb_addr obloc = *bloc;

		if (!(bloc->logicalBlockNum = udf_new_block(inode->i_sb, NULL,
			obloc.partitionReferenceNum, obloc.logicalBlockNum, &err)))
		{
			return -1;
		}
		if (!(nbh = udf_tgetblk(inode->i_sb, udf_get_lb_pblock(inode->i_sb,
			*bloc, 0))))
		{
			return -1;
		}
		lock_buffer(nbh);
		memset(nbh->b_data, 0x00, inode->i_sb->s_blocksize);
		set_buffer_uptodate(nbh);
		unlock_buffer(nbh);
		mark_buffer_dirty_inode(nbh, inode);

		aed = (struct allocExtDesc *)(nbh->b_data);
		if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT))
			aed->previousAllocExtLocation = cpu_to_le32(obloc.logicalBlockNum);
		if (*extoffset + adsize > inode->i_sb->s_blocksize)
		{
			loffset = *extoffset;
			aed->lengthAllocDescs = cpu_to_le32(adsize);
			sptr = ptr - adsize;
			dptr = nbh->b_data + sizeof(struct allocExtDesc);
			memcpy(dptr, sptr, adsize);
			*extoffset = sizeof(struct allocExtDesc) + adsize;
		}
		else
		{
			loffset = *extoffset + adsize;
			aed->lengthAllocDescs = cpu_to_le32(0);
			sptr = ptr;
			*extoffset = sizeof(struct allocExtDesc);

			if (*bh)
			{
				aed = (struct allocExtDesc *)(*bh)->b_data;
				aed->lengthAllocDescs =
					cpu_to_le32(le32_to_cpu(aed->lengthAllocDescs) + adsize);
			}
			else
			{
				UDF_I_LENALLOC(inode) += adsize;
				mark_inode_dirty(inode);
			}
		}
		if (UDF_SB_UDFREV(inode->i_sb) >= 0x0200)
			udf_new_tag(nbh->b_data, TAG_IDENT_AED, 3, 1,
				bloc->logicalBlockNum, sizeof(tag));
		else
			udf_new_tag(nbh->b_data, TAG_IDENT_AED, 2, 1,
				bloc->logicalBlockNum, sizeof(tag));
		switch (UDF_I_ALLOCTYPE(inode))
		{
			case ICBTAG_FLAG_AD_SHORT:
			{
				sad = (short_ad *)sptr;
				sad->extLength = cpu_to_le32(
					EXT_NEXT_EXTENT_ALLOCDECS |
					inode->i_sb->s_blocksize);
				sad->extPosition = cpu_to_le32(bloc->logicalBlockNum);
				break;
			}
			case ICBTAG_FLAG_AD_LONG:
			{
				lad = (long_ad *)sptr;
				lad->extLength = cpu_to_le32(
					EXT_NEXT_EXTENT_ALLOCDECS |
					inode->i_sb->s_blocksize);
				lad->extLocation = cpu_to_lelb(*bloc);
				memset(lad->impUse, 0x00, sizeof(lad->impUse));
				break;
			}
		}
		if (*bh)
		{
			if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) || UDF_SB_UDFREV(inode->i_sb) >= 0x0201)
				udf_update_tag((*bh)->b_data, loffset);
			else
				udf_update_tag((*bh)->b_data, sizeof(struct allocExtDesc));
			mark_buffer_dirty_inode(*bh, inode);
			udf_release_data(*bh);
		}
		else
			mark_inode_dirty(inode);
		*bh = nbh;
	}

	etype = udf_write_aext(inode, *bloc, extoffset, eloc, elen, *bh, inc);

	if (!*bh)
	{
		UDF_I_LENALLOC(inode) += adsize;
		mark_inode_dirty(inode);
	}
	else
	{
		aed = (struct allocExtDesc *)(*bh)->b_data;
		aed->lengthAllocDescs =
			cpu_to_le32(le32_to_cpu(aed->lengthAllocDescs) + adsize);
		if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) || UDF_SB_UDFREV(inode->i_sb) >= 0x0201)
			udf_update_tag((*bh)->b_data, *extoffset + (inc ? 0 : adsize));
		else
			udf_update_tag((*bh)->b_data, sizeof(struct allocExtDesc));
		mark_buffer_dirty_inode(*bh, inode);
	}

	return etype;
}

int8_t udf_write_aext(struct inode *inode, lb_addr bloc, int *extoffset,
    lb_addr eloc, uint32_t elen, struct buffer_head *bh, int inc)
{
	int adsize;
	uint8_t *ptr;

	if (!bh)
		ptr = UDF_I_DATA(inode) + *extoffset - udf_file_entry_alloc_offset(inode) + UDF_I_LENEATTR(inode);
	else
	{
		ptr = bh->b_data + *extoffset;
		atomic_inc(&bh->b_count);
	}

	switch (UDF_I_ALLOCTYPE(inode))
	{
		case ICBTAG_FLAG_AD_SHORT:
		{
			short_ad *sad = (short_ad *)ptr;
			sad->extLength = cpu_to_le32(elen);
			sad->extPosition = cpu_to_le32(eloc.logicalBlockNum);
			adsize = sizeof(short_ad);
			break;
		}
		case ICBTAG_FLAG_AD_LONG:
		{
			long_ad *lad = (long_ad *)ptr;
			lad->extLength = cpu_to_le32(elen);
			lad->extLocation = cpu_to_lelb(eloc);
			memset(lad->impUse, 0x00, sizeof(lad->impUse));
			adsize = sizeof(long_ad);
			break;
		}
		default:
			return -1;
	}

	if (bh)
	{
		if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) || UDF_SB_UDFREV(inode->i_sb) >= 0x0201)
		{
			struct allocExtDesc *aed = (struct allocExtDesc *)(bh)->b_data;
			udf_update_tag((bh)->b_data,
				le32_to_cpu(aed->lengthAllocDescs) + sizeof(struct allocExtDesc));
		}
		mark_buffer_dirty_inode(bh, inode);
		udf_release_data(bh);
	}
	else
		mark_inode_dirty(inode);

	if (inc)
		*extoffset += adsize;
	return (elen >> 30);
}

int8_t udf_next_aext(struct inode *inode, lb_addr *bloc, int *extoffset,
	lb_addr *eloc, uint32_t *elen, struct buffer_head **bh, int inc)
{
	int8_t etype;

	while ((etype = udf_current_aext(inode, bloc, extoffset, eloc, elen, bh, inc)) ==
		(EXT_NEXT_EXTENT_ALLOCDECS >> 30))
	{
		*bloc = *eloc;
		*extoffset = sizeof(struct allocExtDesc);
		udf_release_data(*bh);
		if (!(*bh = udf_tread(inode->i_sb, udf_get_lb_pblock(inode->i_sb, *bloc, 0))))
		{
			udf_debug("reading block %d failed!\n",
				udf_get_lb_pblock(inode->i_sb, *bloc, 0));
			return -1;
		}
	}

	return etype;
}

int8_t udf_current_aext(struct inode *inode, lb_addr *bloc, int *extoffset,
	lb_addr *eloc, uint32_t *elen, struct buffer_head **bh, int inc)
{
	int alen;
	int8_t etype;
	uint8_t *ptr;

	if (!*bh)
	{
		if (!(*extoffset))
			*extoffset = udf_file_entry_alloc_offset(inode);
		ptr = UDF_I_DATA(inode) + *extoffset - udf_file_entry_alloc_offset(inode) + UDF_I_LENEATTR(inode);
		alen = udf_file_entry_alloc_offset(inode) + UDF_I_LENALLOC(inode);
	}
	else
	{
		if (!(*extoffset))
			*extoffset = sizeof(struct allocExtDesc);
		ptr = (*bh)->b_data + *extoffset;
		alen = sizeof(struct allocExtDesc) + le32_to_cpu(((struct allocExtDesc *)(*bh)->b_data)->lengthAllocDescs);
	}

	switch (UDF_I_ALLOCTYPE(inode))
	{
		case ICBTAG_FLAG_AD_SHORT:
		{
			short_ad *sad;

			if (!(sad = udf_get_fileshortad(ptr, alen, extoffset, inc)))
				return -1;

			etype = le32_to_cpu(sad->extLength) >> 30;
			eloc->logicalBlockNum = le32_to_cpu(sad->extPosition);
			eloc->partitionReferenceNum = UDF_I_LOCATION(inode).partitionReferenceNum;
			*elen = le32_to_cpu(sad->extLength) & UDF_EXTENT_LENGTH_MASK;
			break;
		}
		case ICBTAG_FLAG_AD_LONG:
		{
			long_ad *lad;

			if (!(lad = udf_get_filelongad(ptr, alen, extoffset, inc)))
				return -1;

			etype = le32_to_cpu(lad->extLength) >> 30;
			*eloc = lelb_to_cpu(lad->extLocation);
			*elen = le32_to_cpu(lad->extLength) & UDF_EXTENT_LENGTH_MASK;
			break;
		}
		default:
		{
			udf_debug("alloc_type = %d unsupported\n", UDF_I_ALLOCTYPE(inode));
			return -1;
		}
	}

	return etype;
}

int8_t udf_insert_aext(struct inode *inode, lb_addr bloc, int extoffset,
	lb_addr neloc, uint32_t nelen, struct buffer_head *bh)
{
	lb_addr oeloc;
	uint32_t oelen;
	int8_t etype;

	if (bh)
		atomic_inc(&bh->b_count);

	while ((etype = udf_next_aext(inode, &bloc, &extoffset, &oeloc, &oelen, &bh, 0)) != -1)
	{
		udf_write_aext(inode, bloc, &extoffset, neloc, nelen, bh, 1);

		neloc = oeloc;
		nelen = (etype << 30) | oelen;
	}
	udf_add_aext(inode, &bloc, &extoffset, neloc, nelen, &bh, 1);
	udf_release_data(bh);
	return (nelen >> 30);
}

int8_t udf_delete_aext(struct inode *inode, lb_addr nbloc, int nextoffset,
	lb_addr eloc, uint32_t elen, struct buffer_head *nbh)
{
	struct buffer_head *obh;
	lb_addr obloc;
	int oextoffset, adsize;
	int8_t etype;
	struct allocExtDesc *aed;

	if (nbh)
	{
		atomic_inc(&nbh->b_count);
		atomic_inc(&nbh->b_count);
	}

	if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_SHORT)
		adsize = sizeof(short_ad);
	else if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_LONG)
		adsize = sizeof(long_ad);
	else
		adsize = 0;

	obh = nbh;
	obloc = nbloc;
	oextoffset = nextoffset;

	if (udf_next_aext(inode, &nbloc, &nextoffset, &eloc, &elen, &nbh, 1) == -1)
		return -1;

	while ((etype = udf_next_aext(inode, &nbloc, &nextoffset, &eloc, &elen, &nbh, 1)) != -1)
	{
		udf_write_aext(inode, obloc, &oextoffset, eloc, (etype << 30) | elen, obh, 1);
		if (obh != nbh)
		{
			obloc = nbloc;
			udf_release_data(obh);
			atomic_inc(&nbh->b_count);
			obh = nbh;
			oextoffset = nextoffset - adsize;
		}
	}
	memset(&eloc, 0x00, sizeof(lb_addr));
	elen = 0;

	if (nbh != obh)
	{
		udf_free_blocks(inode->i_sb, inode, nbloc, 0, 1);
		udf_write_aext(inode, obloc, &oextoffset, eloc, elen, obh, 1);
		udf_write_aext(inode, obloc, &oextoffset, eloc, elen, obh, 1);
		if (!obh)
		{
			UDF_I_LENALLOC(inode) -= (adsize * 2);
			mark_inode_dirty(inode);
		}
		else
		{
			aed = (struct allocExtDesc *)(obh)->b_data;
			aed->lengthAllocDescs =
				cpu_to_le32(le32_to_cpu(aed->lengthAllocDescs) - (2*adsize));
			if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) || UDF_SB_UDFREV(inode->i_sb) >= 0x0201)
				udf_update_tag((obh)->b_data, oextoffset - (2*adsize));
			else
				udf_update_tag((obh)->b_data, sizeof(struct allocExtDesc));
			mark_buffer_dirty_inode(obh, inode);
		}
	}
	else
	{
		udf_write_aext(inode, obloc, &oextoffset, eloc, elen, obh, 1);
		if (!obh)
		{
			UDF_I_LENALLOC(inode) -= adsize;
			mark_inode_dirty(inode);
		}
		else
		{
			aed = (struct allocExtDesc *)(obh)->b_data;
			aed->lengthAllocDescs =
				cpu_to_le32(le32_to_cpu(aed->lengthAllocDescs) - adsize);
			if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) || UDF_SB_UDFREV(inode->i_sb) >= 0x0201)
				udf_update_tag((obh)->b_data, oextoffset - adsize);
			else
				udf_update_tag((obh)->b_data, sizeof(struct allocExtDesc));
			mark_buffer_dirty_inode(obh, inode);
		}
	}
	
	udf_release_data(nbh);
	udf_release_data(obh);
	return (elen >> 30);
}

int8_t inode_bmap(struct inode *inode, int block, lb_addr *bloc, uint32_t *extoffset,
	lb_addr *eloc, uint32_t *elen, uint32_t *offset, struct buffer_head **bh)
{
	uint64_t lbcount = 0, bcount = (uint64_t)block << inode->i_sb->s_blocksize_bits;
	int8_t etype;

	if (block < 0)
	{
		printk(KERN_ERR "udf: inode_bmap: block < 0\n");
		return -1;
	}
	if (!inode)
	{
		printk(KERN_ERR "udf: inode_bmap: NULL inode\n");
		return -1;
	}

	*extoffset = 0;
	*elen = 0;
	*bloc = UDF_I_LOCATION(inode);

	do
	{
		if ((etype = udf_next_aext(inode, bloc, extoffset, eloc, elen, bh, 1)) == -1)
		{
			*offset = bcount - lbcount;
			UDF_I_LENEXTENTS(inode) = lbcount;
			return -1;
		}
		lbcount += *elen;
	} while (lbcount <= bcount);

	*offset = bcount + *elen - lbcount;

	return etype;
}

long udf_block_map(struct inode *inode, long block)
{
	lb_addr eloc, bloc;
	uint32_t offset, extoffset, elen;
	struct buffer_head *bh = NULL;
	int ret;

	lock_kernel();

	if (inode_bmap(inode, block, &bloc, &extoffset, &eloc, &elen, &offset, &bh) == (EXT_RECORDED_ALLOCATED >> 30))
		ret = udf_get_lb_pblock(inode->i_sb, eloc, offset >> inode->i_sb->s_blocksize_bits);
	else
		ret = 0;

	unlock_kernel();
	udf_release_data(bh);

	if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_VARCONV))
		return udf_fixed_to_variable(ret);
	else
		return ret;
}