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|
/*
* rw_bitmaps.c --- routines to read and write the inode and block bitmaps.
*
* Copyright (C) 1993, 1994, 1994, 1996 Theodore Ts'o.
*
* %Begin-Header%
* This file may be redistributed under the terms of the GNU Public
* License.
* %End-Header%
*/
#include <stdio.h>
#include <string.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <fcntl.h>
#include <time.h>
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include "ext2_fs.h"
#include "ext2fs.h"
#include "e2image.h"
static errcode_t write_bitmaps(ext2_filsys fs, int do_inode, int do_block)
{
dgrp_t i;
unsigned int j;
int block_nbytes, inode_nbytes;
unsigned int nbits;
errcode_t retval;
char *block_buf, *inode_buf;
int csum_flag = 0;
blk_t blk;
blk64_t blk_itr = fs->super->s_first_data_block;
ext2_ino_t ino_itr = 1;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if (!(fs->flags & EXT2_FLAG_RW))
return EXT2_ET_RO_FILSYS;
if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
csum_flag = 1;
inode_nbytes = block_nbytes = 0;
if (do_block) {
block_nbytes = EXT2_BLOCKS_PER_GROUP(fs->super) / 8;
retval = ext2fs_get_mem(fs->blocksize, &block_buf);
if (retval)
return retval;
memset(block_buf, 0xff, fs->blocksize);
}
if (do_inode) {
inode_nbytes = (size_t)
((EXT2_INODES_PER_GROUP(fs->super)+7) / 8);
retval = ext2fs_get_mem(fs->blocksize, &inode_buf);
if (retval)
return retval;
memset(inode_buf, 0xff, fs->blocksize);
}
for (i = 0; i < fs->group_desc_count; i++) {
if (!do_block)
goto skip_block_bitmap;
if (csum_flag && ext2fs_bg_flags_test(fs, i, EXT2_BG_BLOCK_UNINIT)
)
goto skip_this_block_bitmap;
retval = ext2fs_get_block_bitmap_range2(fs->block_map,
blk_itr, block_nbytes << 3, block_buf);
if (retval)
return retval;
if (i == fs->group_desc_count - 1) {
/* Force bitmap padding for the last group */
nbits = ((ext2fs_blocks_count(fs->super)
- (__u64) fs->super->s_first_data_block)
% (__u64) EXT2_BLOCKS_PER_GROUP(fs->super));
if (nbits)
for (j = nbits; j < fs->blocksize * 8; j++)
ext2fs_set_bit(j, block_buf);
}
blk = fs->group_desc[i].bg_block_bitmap;
if (blk) {
retval = io_channel_write_blk64(fs->io, blk, 1,
block_buf);
if (retval)
return EXT2_ET_BLOCK_BITMAP_WRITE;
}
skip_this_block_bitmap:
blk_itr += block_nbytes << 3;
skip_block_bitmap:
if (!do_inode)
continue;
if (csum_flag && ext2fs_bg_flags_test(fs, i, EXT2_BG_INODE_UNINIT)
)
goto skip_this_inode_bitmap;
retval = ext2fs_get_inode_bitmap_range2(fs->inode_map,
ino_itr, inode_nbytes << 3, inode_buf);
if (retval)
return retval;
blk = fs->group_desc[i].bg_inode_bitmap;
if (blk) {
retval = io_channel_write_blk64(fs->io, blk, 1,
inode_buf);
if (retval)
return EXT2_ET_INODE_BITMAP_WRITE;
}
skip_this_inode_bitmap:
ino_itr += inode_nbytes << 3;
}
if (do_block) {
fs->flags &= ~EXT2_FLAG_BB_DIRTY;
ext2fs_free_mem(&block_buf);
}
if (do_inode) {
fs->flags &= ~EXT2_FLAG_IB_DIRTY;
ext2fs_free_mem(&inode_buf);
}
return 0;
}
static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block)
{
dgrp_t i;
char *block_bitmap = 0, *inode_bitmap = 0;
char *buf;
errcode_t retval;
int block_nbytes = EXT2_BLOCKS_PER_GROUP(fs->super) / 8;
int inode_nbytes = EXT2_INODES_PER_GROUP(fs->super) / 8;
int csum_flag = 0;
int do_image = fs->flags & EXT2_FLAG_IMAGE_FILE;
unsigned int cnt;
blk_t blk;
blk64_t blk_itr = fs->super->s_first_data_block;
blk_t blk_cnt;
ext2_ino_t ino_itr = 1;
ext2_ino_t ino_cnt;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
fs->write_bitmaps = ext2fs_write_bitmaps;
if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
csum_flag = 1;
retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf);
if (retval)
return retval;
if (do_block) {
if (fs->block_map)
ext2fs_free_block_bitmap(fs->block_map);
strcpy(buf, "block bitmap for ");
strcat(buf, fs->device_name);
retval = ext2fs_allocate_block_bitmap(fs, buf, &fs->block_map);
if (retval)
goto cleanup;
retval = ext2fs_get_mem(do_image ? fs->blocksize :
(unsigned) block_nbytes, &block_bitmap);
if (retval)
goto cleanup;
} else
block_nbytes = 0;
if (do_inode) {
if (fs->inode_map)
ext2fs_free_inode_bitmap(fs->inode_map);
strcpy(buf, "inode bitmap for ");
strcat(buf, fs->device_name);
retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map);
if (retval)
goto cleanup;
retval = ext2fs_get_mem(do_image ? fs->blocksize :
(unsigned) inode_nbytes, &inode_bitmap);
if (retval)
goto cleanup;
} else
inode_nbytes = 0;
ext2fs_free_mem(&buf);
if (fs->flags & EXT2_FLAG_IMAGE_FILE) {
blk = (fs->image_header->offset_inodemap / fs->blocksize);
ino_cnt = fs->super->s_inodes_count;
while (inode_nbytes > 0) {
retval = io_channel_read_blk64(fs->image_io, blk++,
1, inode_bitmap);
if (retval)
goto cleanup;
cnt = fs->blocksize << 3;
if (cnt > ino_cnt)
cnt = ino_cnt;
retval = ext2fs_set_inode_bitmap_range2(fs->inode_map,
ino_itr, cnt, inode_bitmap);
if (retval)
goto cleanup;
ino_itr += fs->blocksize << 3;
ino_cnt -= fs->blocksize << 3;
inode_nbytes -= fs->blocksize;
}
blk = (fs->image_header->offset_blockmap /
fs->blocksize);
blk_cnt = (blk64_t)EXT2_BLOCKS_PER_GROUP(fs->super) *
fs->group_desc_count;
while (block_nbytes > 0) {
retval = io_channel_read_blk64(fs->image_io, blk++,
1, block_bitmap);
if (retval)
goto cleanup;
cnt = fs->blocksize << 3;
if (cnt > blk_cnt)
cnt = blk_cnt;
retval = ext2fs_set_block_bitmap_range2(fs->block_map,
blk_itr, cnt, block_bitmap);
if (retval)
goto cleanup;
blk_itr += fs->blocksize << 3;
blk_cnt -= fs->blocksize << 3;
block_nbytes -= fs->blocksize;
}
goto success_cleanup;
}
for (i = 0; i < fs->group_desc_count; i++) {
if (block_bitmap) {
blk = fs->group_desc[i].bg_block_bitmap;
if (csum_flag &&
ext2fs_bg_flags_test(fs, i, EXT2_BG_BLOCK_UNINIT) &&
ext2fs_group_desc_csum_verify(fs, i))
blk = 0;
if (blk) {
retval = io_channel_read_blk64(fs->io, blk,
-block_nbytes, block_bitmap);
if (retval) {
retval = EXT2_ET_BLOCK_BITMAP_READ;
goto cleanup;
}
} else
memset(block_bitmap, 0, block_nbytes);
cnt = block_nbytes << 3;
retval = ext2fs_set_block_bitmap_range2(fs->block_map,
blk_itr, cnt, block_bitmap);
if (retval)
goto cleanup;
blk_itr += block_nbytes << 3;
}
if (inode_bitmap) {
blk = fs->group_desc[i].bg_inode_bitmap;
if (csum_flag &&
ext2fs_bg_flags_test(fs, i, EXT2_BG_INODE_UNINIT) &&
ext2fs_group_desc_csum_verify(fs, i))
blk = 0;
if (blk) {
retval = io_channel_read_blk64(fs->io, blk,
-inode_nbytes, inode_bitmap);
if (retval) {
retval = EXT2_ET_INODE_BITMAP_READ;
goto cleanup;
}
} else
memset(inode_bitmap, 0, inode_nbytes);
cnt = inode_nbytes << 3;
retval = ext2fs_set_inode_bitmap_range2(fs->inode_map,
ino_itr, cnt, inode_bitmap);
if (retval)
goto cleanup;
ino_itr += inode_nbytes << 3;
}
}
success_cleanup:
if (inode_bitmap)
ext2fs_free_mem(&inode_bitmap);
if (block_bitmap)
ext2fs_free_mem(&block_bitmap);
return 0;
cleanup:
if (do_block) {
ext2fs_free_mem(&fs->block_map);
fs->block_map = 0;
}
if (do_inode) {
ext2fs_free_mem(&fs->inode_map);
fs->inode_map = 0;
}
if (inode_bitmap)
ext2fs_free_mem(&inode_bitmap);
if (block_bitmap)
ext2fs_free_mem(&block_bitmap);
if (buf)
ext2fs_free_mem(&buf);
return retval;
}
errcode_t ext2fs_read_inode_bitmap(ext2_filsys fs)
{
return read_bitmaps(fs, 1, 0);
}
errcode_t ext2fs_read_block_bitmap(ext2_filsys fs)
{
return read_bitmaps(fs, 0, 1);
}
errcode_t ext2fs_write_inode_bitmap(ext2_filsys fs)
{
return write_bitmaps(fs, 1, 0);
}
errcode_t ext2fs_write_block_bitmap (ext2_filsys fs)
{
return write_bitmaps(fs, 0, 1);
}
errcode_t ext2fs_read_bitmaps(ext2_filsys fs)
{
if (fs->inode_map && fs->block_map)
return 0;
return read_bitmaps(fs, !fs->inode_map, !fs->block_map);
}
errcode_t ext2fs_write_bitmaps(ext2_filsys fs)
{
int do_inode = fs->inode_map && ext2fs_test_ib_dirty(fs);
int do_block = fs->block_map && ext2fs_test_bb_dirty(fs);
if (!do_inode && !do_block)
return 0;
return write_bitmaps(fs, do_inode, do_block);
}
|
