q3k/linux
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity
linux/fs/udf/misc.c
Sebastian Manciulea f4bcbbd92e udf: Fix handling of multisession media 
According to OSTA UDF specification, only anchor blocks and primary volume
descriptors are placed on media relative to the last session. All other block
numbers are absolute (in the partition or the whole media). This seems to be
confirmed by multisession media created by other systems.

Signed-off-by: Sebastian Manciulea <manciuleas@yahoo.com>
Signed-off-by: Jan Kara <jack@suse.cz>
2008-04-17 14:28:33 +02:00

293 lines
7.5 KiB
C
Raw Blame History

/*
* misc.c
*
* PURPOSE
* Miscellaneous routines for the OSTA-UDF(tm) filesystem.
*
* 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) 1998-2004 Ben Fennema
* (C) 1999-2000 Stelias Computing Inc
*
* HISTORY
*
* 04/19/99 blf partial support for reading/writing specific EA's
*/
#include "udfdecl.h"
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/buffer_head.h>
#include "udf_i.h"
#include "udf_sb.h"
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);
}
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);
}
struct genericFormat *udf_add_extendedattr(struct inode *inode, uint32_t size,
uint32_t type, uint8_t loc)
{
uint8_t *ea = NULL, *ad = NULL;
int offset;
uint16_t crclen;
struct udf_inode_info *iinfo = UDF_I(inode);
ea = iinfo->i_ext.i_data;
if (iinfo->i_lenEAttr) {
ad = iinfo->i_ext.i_data + iinfo->i_lenEAttr;
} else {
ad = ea;
size += sizeof(struct extendedAttrHeaderDesc);
}
offset = inode->i_sb->s_blocksize - udf_file_entry_alloc_offset(inode) -
iinfo->i_lenAlloc;
/* TODO - Check for FreeEASpace */
if (loc & 0x01 && offset >= size) {
struct extendedAttrHeaderDesc *eahd;
eahd = (struct extendedAttrHeaderDesc *)ea;
if (iinfo->i_lenAlloc)
memmove(&ad[size], ad, iinfo->i_lenAlloc);
if (iinfo->i_lenEAttr) {
/* check checksum/crc */
if (eahd->descTag.tagIdent !=
cpu_to_le16(TAG_IDENT_EAHD) ||
le32_to_cpu(eahd->descTag.tagLocation) !=
iinfo->i_location.logicalBlockNum)
return NULL;
} else {
struct udf_sb_info *sbi = UDF_SB(inode->i_sb);
size -= sizeof(struct extendedAttrHeaderDesc);
iinfo->i_lenEAttr +=
sizeof(struct extendedAttrHeaderDesc);
eahd->descTag.tagIdent = cpu_to_le16(TAG_IDENT_EAHD);
if (sbi->s_udfrev >= 0x0200)
eahd->descTag.descVersion = cpu_to_le16(3);
else
eahd->descTag.descVersion = cpu_to_le16(2);
eahd->descTag.tagSerialNum =
cpu_to_le16(sbi->s_serial_number);
eahd->descTag.tagLocation = cpu_to_le32(
iinfo->i_location.logicalBlockNum);
eahd->impAttrLocation = cpu_to_le32(0xFFFFFFFF);
eahd->appAttrLocation = cpu_to_le32(0xFFFFFFFF);
}
offset = iinfo->i_lenEAttr;
if (type < 2048) {
if (le32_to_cpu(eahd->appAttrLocation) <
iinfo->i_lenEAttr) {
uint32_t 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) <
iinfo->i_lenEAttr) {
uint32_t 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) <
iinfo->i_lenEAttr) {
uint32_t 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 */
crclen = sizeof(struct extendedAttrHeaderDesc) - sizeof(tag);
eahd->descTag.descCRCLength = cpu_to_le16(crclen);
eahd->descTag.descCRC = cpu_to_le16(udf_crc((char *)eahd +
sizeof(tag), crclen, 0));
eahd->descTag.tagChecksum = udf_tag_checksum(&eahd->descTag);
iinfo->i_lenEAttr += size;
return (struct genericFormat *)&ea[offset];
}
if (loc & 0x02)
;
return NULL;
}
struct genericFormat *udf_get_extendedattr(struct inode *inode, uint32_t type,
uint8_t subtype)
{
struct genericFormat *gaf;
uint8_t *ea = NULL;
uint32_t offset;
struct udf_inode_info *iinfo = UDF_I(inode);
ea = iinfo->i_ext.i_data;
if (iinfo->i_lenEAttr) {
struct extendedAttrHeaderDesc *eahd;
eahd = (struct extendedAttrHeaderDesc *)ea;
/* check checksum/crc */
if (eahd->descTag.tagIdent !=
cpu_to_le16(TAG_IDENT_EAHD) ||
le32_to_cpu(eahd->descTag.tagLocation) !=
iinfo->i_location.logicalBlockNum)
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 < iinfo->i_lenEAttr) {
gaf = (struct genericFormat *)&ea[offset];
if (le32_to_cpu(gaf->attrType) == type &&
gaf->attrSubtype == subtype)
return gaf;
else
offset += le32_to_cpu(gaf->attrLength);
}
}
return NULL;
}
/*
* udf_read_tagged
*
* PURPOSE
* Read the first block of a tagged descriptor.
*
* HISTORY
* July 1, 1997 - Andrew E. Mileski
* Written, tested, and released.
*/
struct buffer_head *udf_read_tagged(struct super_block *sb, uint32_t block,
uint32_t location, uint16_t *ident)
{
tag *tag_p;
struct buffer_head *bh = NULL;
/* 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 */
if (udf_tag_checksum(tag_p) != tag_p->tagChecksum) {
printk(KERN_ERR "udf: tag checksum failed block %d\n", block);
goto error_out;
}
/* Verify the tag version */
if (tag_p->descVersion != cpu_to_le16(0x0002U) &&
tag_p->descVersion != cpu_to_le16(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;
}
struct buffer_head *udf_read_ptagged(struct super_block *sb, kernel_lb_addr loc,
uint32_t offset, uint16_t *ident)
{
return udf_read_tagged(sb, udf_get_lb_pblock(sb, loc, offset),
loc.logicalBlockNum + offset, ident);
}
void udf_update_tag(char *data, int length)
{
tag *tptr = (tag *)data;
length -= sizeof(tag);
tptr->descCRCLength = cpu_to_le16(length);
tptr->descCRC = cpu_to_le16(udf_crc(data + sizeof(tag), length, 0));
tptr->tagChecksum = udf_tag_checksum(tptr);
}
void udf_new_tag(char *data, uint16_t ident, uint16_t version, uint16_t snum,
uint32_t loc, int length)
{
tag *tptr = (tag *)data;
tptr->tagIdent = cpu_to_le16(ident);
tptr->descVersion = cpu_to_le16(version);
tptr->tagSerialNum = cpu_to_le16(snum);
tptr->tagLocation = cpu_to_le32(loc);
udf_update_tag(data, length);
}
u8 udf_tag_checksum(const tag *t)
{
u8 *data = (u8 *)t;
u8 checksum = 0;
int i;
for (i = 0; i < sizeof(tag); ++i)
if (i != 4) /* position of checksum */
checksum += data[i];
return checksum;
}
Reference in a new issue View git blame Copy permalink