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/*
* truncate.c
*
* PURPOSE
* Truncate handling 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@hootie.lvld.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) 1999-2000 Ben Fennema
* (C) 1999 Stelias Computing Inc
*
* HISTORY
*
* 02/24/99 blf Created.
*
*/
#include "udfdecl.h"
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/udf_fs.h>
#include "udf_i.h"
#include "udf_sb.h"
static void extent_trunc(struct inode * inode, lb_addr bloc, int *extoffset,
lb_addr eloc, Uint8 etype, Uint32 elen, struct buffer_head **bh, Uint32 offset)
{
lb_addr neloc = { 0, 0 };
int nelen = 0;
int blocks = inode->i_sb->s_blocksize / 512;
int last_block = (elen + inode->i_sb->s_blocksize - 1) >> inode->i_sb->s_blocksize_bits;
if (offset)
{
nelen = (etype << 30) |
(((offset - 1) << inode->i_sb->s_blocksize_bits) +
(inode->i_size & (inode->i_sb->s_blocksize - 1)));
neloc = eloc;
}
if (etype == EXTENT_RECORDED_ALLOCATED)
inode->i_blocks -= (blocks * (last_block - offset));
udf_write_aext(inode, bloc, extoffset, neloc, nelen, bh, 1);
mark_inode_dirty(inode);
if (etype != EXTENT_NOT_RECORDED_NOT_ALLOCATED)
udf_free_blocks(inode, eloc, offset, last_block - offset);
}
void udf_trunc(struct inode * inode)
{
lb_addr bloc, eloc, neloc = { 0, 0 };
Uint32 extoffset, elen, offset, nelen = 0, lelen = 0, lenalloc;
int etype;
int first_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >> inode->i_sb->s_blocksize_bits;
struct buffer_head *bh = NULL;
int adsize;
if (UDF_I_ALLOCTYPE(inode) == ICB_FLAG_AD_SHORT)
adsize = sizeof(short_ad);
else if (UDF_I_ALLOCTYPE(inode) == ICB_FLAG_AD_LONG)
adsize = sizeof(long_ad);
else
adsize = 0;
if ((etype = inode_bmap(inode, first_block, &bloc, &extoffset, &eloc, &elen, &offset, &bh)) != -1)
{
extoffset -= adsize;
extent_trunc(inode, bloc, &extoffset, eloc, etype, elen, &bh, offset);
if (offset)
lenalloc = extoffset;
else
lenalloc = extoffset - adsize;
if (!memcmp(&UDF_I_LOCATION(inode), &bloc, sizeof(lb_addr)))
lenalloc -= udf_file_entry_alloc_offset(inode);
else
lenalloc -= sizeof(struct AllocExtDesc);
while ((etype = udf_current_aext(inode, &bloc, &extoffset, &eloc, &elen, &bh, 0)) != -1)
{
if (etype == EXTENT_NEXT_EXTENT_ALLOCDECS)
{
udf_write_aext(inode, bloc, &extoffset, neloc, nelen, &bh, 0);
extoffset = 0;
if (lelen)
{
if (!memcmp(&UDF_I_LOCATION(inode), &bloc, sizeof(lb_addr)))
memset(bh->b_data, 0x00, udf_file_entry_alloc_offset(inode));
else
memset(bh->b_data, 0x00, sizeof(struct AllocExtDesc));
udf_free_blocks(inode, bloc, 0, lelen);
}
else
{
if (!memcmp(&UDF_I_LOCATION(inode), &bloc, sizeof(lb_addr)))
UDF_I_LENALLOC(inode) = lenalloc;
else
{
struct AllocExtDesc *aed = (struct AllocExtDesc *)(bh->b_data);
aed->lengthAllocDescs = cpu_to_le32(lenalloc);
}
}
udf_release_data(bh);
bh = NULL;
bloc = eloc;
if (elen)
lelen = (elen + inode->i_sb->s_blocksize - 1) >>
inode->i_sb->s_blocksize_bits;
else
lelen = 1;
}
else
extent_trunc(inode, bloc, &extoffset, eloc, etype, elen, &bh, 0);
}
if (lelen)
{
if (!memcmp(&UDF_I_LOCATION(inode), &bloc, sizeof(lb_addr)))
memset(bh->b_data, 0x00, udf_file_entry_alloc_offset(inode));
else
memset(bh->b_data, 0x00, sizeof(struct AllocExtDesc));
udf_free_blocks(inode, bloc, 0, lelen);
}
else
{
if (!memcmp(&UDF_I_LOCATION(inode), &bloc, sizeof(lb_addr)))
UDF_I_LENALLOC(inode) = lenalloc;
else
{
struct AllocExtDesc *aed = (struct AllocExtDesc *)(bh->b_data);
aed->lengthAllocDescs = cpu_to_le32(lenalloc);
}
}
}
else if (inode->i_size)
{
char tetype;
if (offset)
{
extoffset -= adsize;
tetype = udf_next_aext(inode, &bloc, &extoffset, &eloc, &elen, &bh, 1);
if (tetype == EXTENT_NOT_RECORDED_NOT_ALLOCATED)
{
extoffset -= adsize;
elen = (EXTENT_NOT_RECORDED_NOT_ALLOCATED << 30) |
(elen + (offset << inode->i_sb->s_blocksize_bits));
udf_write_aext(inode, bloc, &extoffset, eloc, elen, &bh, 0);
}
else
{
if (elen & (inode->i_sb->s_blocksize - 1))
{
extoffset -= adsize;
elen = (EXTENT_RECORDED_ALLOCATED << 30) |
((elen + inode->i_sb->s_blocksize - 1) &
~(inode->i_sb->s_blocksize - 1));
udf_write_aext(inode, bloc, &extoffset, eloc, elen, &bh, 1);
}
memset(&eloc, 0x00, sizeof(lb_addr));
elen = (EXTENT_NOT_RECORDED_NOT_ALLOCATED << 30) |
(offset << inode->i_sb->s_blocksize_bits);
udf_add_aext(inode, &bloc, &extoffset, eloc, elen, &bh, 1);
}
}
}
udf_release_data(bh);
}
void udf_truncate(struct inode * inode)
{
if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
S_ISLNK(inode->i_mode)))
return;
if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
return;
if (UDF_I_ALLOCTYPE(inode) == ICB_FLAG_AD_IN_ICB)
UDF_I_LENALLOC(inode) = inode->i_size;
else
udf_trunc(inode);
inode->i_mtime = inode->i_ctime = CURRENT_TIME;
mark_inode_dirty(inode);
}
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