blob: 5deca2c255797bc1fbb22f5f2f79f41e65b5a80d [file] [log] [blame]
/*
* 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 <stdlib.h>
#include <fcntl.h>
#include <time.h>
#include <sys/stat.h>
#include <sys/types.h>
#if HAVE_ERRNO_H
#include <errno.h>
#endif
#include <linux/ext2_fs.h>
#include "ext2fs.h"
errcode_t ext2fs_write_inode_bitmap(ext2_filsys fs)
{
int i;
size_t nbytes;
errcode_t retval;
char * inode_bitmap = fs->inode_map->bitmap;
char * bitmap_block = NULL;
blk_t blk;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if (!(fs->flags & EXT2_FLAG_RW))
return EXT2_ET_RO_FILSYS;
if (!inode_bitmap)
return 0;
nbytes = (size_t) ((EXT2_INODES_PER_GROUP(fs->super)+7) / 8);
bitmap_block = malloc(fs->blocksize);
if (!bitmap_block)
return ENOMEM;
memset(bitmap_block, 0xff, fs->blocksize);
for (i = 0; i < fs->group_desc_count; i++) {
memcpy(bitmap_block, inode_bitmap, nbytes);
blk = fs->group_desc[i].bg_inode_bitmap;
if (blk) {
retval = io_channel_write_blk(fs->io, blk, 1,
bitmap_block);
if (retval)
return EXT2_ET_INODE_BITMAP_WRITE;
}
inode_bitmap += nbytes;
}
fs->flags |= EXT2_FLAG_CHANGED;
fs->flags &= ~EXT2_FLAG_IB_DIRTY;
free(bitmap_block);
return 0;
}
errcode_t ext2fs_write_block_bitmap (ext2_filsys fs)
{
int i;
int j;
int nbytes;
int nbits;
errcode_t retval;
char * block_bitmap = fs->block_map->bitmap;
char * bitmap_block = NULL;
blk_t blk;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if (!(fs->flags & EXT2_FLAG_RW))
return EXT2_ET_RO_FILSYS;
if (!block_bitmap)
return 0;
nbytes = EXT2_BLOCKS_PER_GROUP(fs->super) / 8;
bitmap_block = malloc(fs->blocksize);
if (!bitmap_block)
return ENOMEM;
memset(bitmap_block, 0xff, fs->blocksize);
for (i = 0; i < fs->group_desc_count; i++) {
memcpy(bitmap_block, block_bitmap, nbytes);
if (i == fs->group_desc_count - 1) {
/* Force bitmap padding for the last group */
nbits = (int) ((fs->super->s_blocks_count
- fs->super->s_first_data_block)
% EXT2_BLOCKS_PER_GROUP(fs->super));
if (nbits)
for (j = nbits; j < fs->blocksize * 8; j++)
ext2fs_set_bit(j, bitmap_block);
}
blk = fs->group_desc[i].bg_block_bitmap;
if (blk) {
retval = io_channel_write_blk(fs->io, blk, 1,
bitmap_block);
if (retval)
return EXT2_ET_BLOCK_BITMAP_WRITE;
}
block_bitmap += nbytes;
}
fs->flags |= EXT2_FLAG_CHANGED;
fs->flags &= ~EXT2_FLAG_BB_DIRTY;
free(bitmap_block);
return 0;
}
static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block)
{
int i;
char *block_bitmap = 0, *inode_bitmap = 0;
char *buf;
errcode_t retval;
int block_nbytes = (int) EXT2_BLOCKS_PER_GROUP(fs->super) / 8;
int inode_nbytes = (int) EXT2_INODES_PER_GROUP(fs->super) / 8;
blk_t blk;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
fs->write_bitmaps = ext2fs_write_bitmaps;
buf = malloc(strlen(fs->device_name) + 80);
if (do_block) {
if (fs->block_map)
ext2fs_free_block_bitmap(fs->block_map);
sprintf(buf, "block bitmap for %s", fs->device_name);
retval = ext2fs_allocate_block_bitmap(fs, buf, &fs->block_map);
if (retval)
goto cleanup;
block_bitmap = fs->block_map->bitmap;
}
if (do_inode) {
if (fs->inode_map)
ext2fs_free_inode_bitmap(fs->inode_map);
sprintf(buf, "inode bitmap for %s", fs->device_name);
retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map);
if (retval)
goto cleanup;
inode_bitmap = fs->inode_map->bitmap;
}
free(buf);
for (i = 0; i < fs->group_desc_count; i++) {
if (block_bitmap) {
blk = fs->group_desc[i].bg_block_bitmap;
if (blk) {
retval = io_channel_read_blk(fs->io, blk,
-block_nbytes, block_bitmap);
if (retval) {
retval = EXT2_ET_BLOCK_BITMAP_READ;
goto cleanup;
}
} else
memset(block_bitmap, 0, block_nbytes);
block_bitmap += block_nbytes;
}
if (inode_bitmap) {
blk = fs->group_desc[i].bg_inode_bitmap;
if (blk) {
retval = io_channel_read_blk(fs->io, blk,
-inode_nbytes, inode_bitmap);
if (retval) {
retval = EXT2_ET_INODE_BITMAP_READ;
goto cleanup;
}
} else
memset(inode_bitmap, 0, inode_nbytes);
inode_bitmap += inode_nbytes;
}
}
return 0;
cleanup:
if (do_block) {
free(fs->block_map);
fs->block_map = 0;
}
if (do_inode) {
free(fs->inode_map);
fs->inode_map = 0;
}
if (buf)
free(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_read_bitmaps(ext2_filsys fs)
{
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
return read_bitmaps(fs, !fs->inode_map, !fs->block_map);
}
errcode_t ext2fs_write_bitmaps(ext2_filsys fs)
{
errcode_t retval;
EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
if (fs->block_map && ext2fs_test_bb_dirty(fs)) {
retval = ext2fs_write_block_bitmap(fs);
if (retval)
return retval;
}
if (fs->inode_map && ext2fs_test_ib_dirty(fs)) {
retval = ext2fs_write_inode_bitmap(fs);
if (retval)
return retval;
}
return 0;
}