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OpenCloudOS-Kernel/fs/udf/truncate.c

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/*
* truncate.c
*
* PURPOSE
* Truncate handling 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) 1999-2004 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 <linux/buffer_head.h>
#include "udf_i.h"
#include "udf_sb.h"
static void extent_trunc(struct inode * inode, kernel_lb_addr bloc, int extoffset,
kernel_lb_addr eloc, int8_t etype, uint32_t elen, struct buffer_head *bh, uint32_t nelen)
{
kernel_lb_addr neloc = { 0, 0 };
int last_block = (elen + inode->i_sb->s_blocksize - 1) >> inode->i_sb->s_blocksize_bits;
int first_block = (nelen + inode->i_sb->s_blocksize - 1) >> inode->i_sb->s_blocksize_bits;
if (nelen)
{
if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30))
{
udf_free_blocks(inode->i_sb, inode, eloc, 0, last_block);
etype = (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30);
}
else
neloc = eloc;
nelen = (etype << 30) | nelen;
}
if (elen != nelen)
{
udf_write_aext(inode, bloc, &extoffset, neloc, nelen, bh, 0);
if (last_block - first_block > 0)
{
if (etype == (EXT_RECORDED_ALLOCATED >> 30))
mark_inode_dirty(inode);
if (etype != (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
udf_free_blocks(inode->i_sb, inode, eloc, first_block, last_block - first_block);
}
}
}
void udf_discard_prealloc(struct inode * inode)
{
kernel_lb_addr bloc, eloc;
uint32_t extoffset = 0, elen, nelen;
uint64_t lbcount = 0;
int8_t etype = -1, netype;
struct buffer_head *bh = NULL;
int adsize;
if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB ||
inode->i_size == UDF_I_LENEXTENTS(inode))
{
return;
}
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;
bloc = UDF_I_LOCATION(inode);
while ((netype = udf_next_aext(inode, &bloc, &extoffset, &eloc, &elen, &bh, 1)) != -1)
{
etype = netype;
lbcount += elen;
if (lbcount > inode->i_size && lbcount - inode->i_size < inode->i_sb->s_blocksize)
{
nelen = elen - (lbcount - inode->i_size);
extent_trunc(inode, bloc, extoffset-adsize, eloc, etype, elen, bh, nelen);
lbcount = inode->i_size;
}
}
if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30))
{
extoffset -= adsize;
lbcount -= elen;
extent_trunc(inode, bloc, extoffset, eloc, etype, elen, bh, 0);
if (!bh)
{
UDF_I_LENALLOC(inode) = extoffset - udf_file_entry_alloc_offset(inode);
mark_inode_dirty(inode);
}
else
{
struct allocExtDesc *aed = (struct allocExtDesc *)(bh->b_data);
aed->lengthAllocDescs = cpu_to_le32(extoffset - sizeof(struct allocExtDesc));
if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) || UDF_SB_UDFREV(inode->i_sb) >= 0x0201)
udf_update_tag(bh->b_data, extoffset);
else
udf_update_tag(bh->b_data, sizeof(struct allocExtDesc));
mark_buffer_dirty_inode(bh, inode);
}
}
UDF_I_LENEXTENTS(inode) = lbcount;
udf_release_data(bh);
}
void udf_truncate_extents(struct inode * inode)
{
kernel_lb_addr bloc, eloc, neloc = { 0, 0 };
uint32_t extoffset, elen, offset, nelen = 0, lelen = 0, lenalloc;
int8_t etype;
int first_block = inode->i_size >> inode->i_sb->s_blocksize_bits;
struct buffer_head *bh = NULL;
int adsize;
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;
etype = inode_bmap(inode, first_block, &bloc, &extoffset, &eloc, &elen, &offset, &bh);
offset += (inode->i_size & (inode->i_sb->s_blocksize - 1));
if (etype != -1)
{
extoffset -= adsize;
extent_trunc(inode, bloc, extoffset, eloc, etype, elen, bh, offset);
extoffset += adsize;
if (offset)
lenalloc = extoffset;
else
lenalloc = extoffset - adsize;
if (!bh)
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 == (EXT_NEXT_EXTENT_ALLOCDECS >> 30))
{
udf_write_aext(inode, bloc, &extoffset, neloc, nelen, bh, 0);
extoffset = 0;
if (lelen)
{
if (!bh)
BUG();
else
memset(bh->b_data, 0x00, sizeof(struct allocExtDesc));
udf_free_blocks(inode->i_sb, inode, bloc, 0, lelen);
}
else
{
if (!bh)
{
UDF_I_LENALLOC(inode) = lenalloc;
mark_inode_dirty(inode);
}
else
{
struct allocExtDesc *aed = (struct allocExtDesc *)(bh->b_data);
aed->lengthAllocDescs = cpu_to_le32(lenalloc);
if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) || UDF_SB_UDFREV(inode->i_sb) >= 0x0201)
udf_update_tag(bh->b_data, lenalloc +
sizeof(struct allocExtDesc));
else
udf_update_tag(bh->b_data, sizeof(struct allocExtDesc));
mark_buffer_dirty_inode(bh, inode);
}
}
udf_release_data(bh);
extoffset = sizeof(struct allocExtDesc);
bloc = eloc;
bh = udf_tread(inode->i_sb, udf_get_lb_pblock(inode->i_sb, bloc, 0));
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);
extoffset += adsize;
}
}
if (lelen)
{
if (!bh)
BUG();
else
memset(bh->b_data, 0x00, sizeof(struct allocExtDesc));
udf_free_blocks(inode->i_sb, inode, bloc, 0, lelen);
}
else
{
if (!bh)
{
UDF_I_LENALLOC(inode) = lenalloc;
mark_inode_dirty(inode);
}
else
{
struct allocExtDesc *aed = (struct allocExtDesc *)(bh->b_data);
aed->lengthAllocDescs = cpu_to_le32(lenalloc);
if (!UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_STRICT) || UDF_SB_UDFREV(inode->i_sb) >= 0x0201)
udf_update_tag(bh->b_data, lenalloc +
sizeof(struct allocExtDesc));
else
udf_update_tag(bh->b_data, sizeof(struct allocExtDesc));
mark_buffer_dirty_inode(bh, inode);
}
}
}
else if (inode->i_size)
{
if (offset)
{
/*
* OK, there is not extent covering inode->i_size and
* no extent above inode->i_size => truncate is
* extending the file by 'offset'.
*/
if ((!bh && extoffset == udf_file_entry_alloc_offset(inode)) ||
(bh && extoffset == sizeof(struct allocExtDesc))) {
/* File has no extents at all! */
memset(&eloc, 0x00, sizeof(kernel_lb_addr));
elen = EXT_NOT_RECORDED_NOT_ALLOCATED | offset;
udf_add_aext(inode, &bloc, &extoffset, eloc, elen, &bh, 1);
}
else {
extoffset -= adsize;
etype = udf_next_aext(inode, &bloc, &extoffset, &eloc, &elen, &bh, 1);
if (etype == (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
{
extoffset -= adsize;
elen = EXT_NOT_RECORDED_NOT_ALLOCATED | (elen + offset);
udf_write_aext(inode, bloc, &extoffset, eloc, elen, bh, 0);
}
else if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30))
{
kernel_lb_addr neloc = { 0, 0 };
extoffset -= adsize;
nelen = EXT_NOT_RECORDED_NOT_ALLOCATED |
((elen + offset + inode->i_sb->s_blocksize - 1) &
~(inode->i_sb->s_blocksize - 1));
udf_write_aext(inode, bloc, &extoffset, neloc, nelen, bh, 1);
udf_add_aext(inode, &bloc, &extoffset, eloc, (etype << 30) | elen, &bh, 1);
}
else
{
if (elen & (inode->i_sb->s_blocksize - 1))
{
extoffset -= adsize;
elen = EXT_RECORDED_ALLOCATED |
((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(kernel_lb_addr));
elen = EXT_NOT_RECORDED_NOT_ALLOCATED | offset;
udf_add_aext(inode, &bloc, &extoffset, eloc, elen, &bh, 1);
}
}
}
}
UDF_I_LENEXTENTS(inode) = inode->i_size;
udf_release_data(bh);
}
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