blob: 42c9c7e41b42c84c71442e25ac1eaa9724a3d3b5 [file] [log] [blame]
/*
* gen_bitmap.c --- Generic (32-bit) bitmap routines
*
* Copyright (C) 2001 Theodore Ts'o.
*
* %Begin-Header%
* This file may be redistributed under the terms of the GNU Library
* General Public License, version 2.
* %End-Header%
*/
#include <stdio.h>
#include <string.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <fcntl.h>
#include <time.h>
#if HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include "ext2_fs.h"
#include "ext2fs.h"
struct ext2fs_struct_generic_bitmap {
errcode_t magic;
ext2_filsys fs;
__u32 start, end;
__u32 real_end;
char * description;
char * bitmap;
errcode_t base_error_code;
__u32 reserved[7];
};
/*
* Used by previously inlined function, so we have to export this and
* not change the function signature
*/
void ext2fs_warn_bitmap2(ext2fs_generic_bitmap bitmap,
int code, unsigned long arg)
{
#ifndef OMIT_COM_ERR
if (bitmap->description)
com_err(0, bitmap->base_error_code+code,
"#%lu for %s", arg, bitmap->description);
else
com_err(0, bitmap->base_error_code + code, "#%lu", arg);
#endif
}
static errcode_t check_magic(ext2fs_generic_bitmap bitmap)
{
if (!bitmap || !((bitmap->magic == EXT2_ET_MAGIC_GENERIC_BITMAP) ||
(bitmap->magic == EXT2_ET_MAGIC_INODE_BITMAP) ||
(bitmap->magic == EXT2_ET_MAGIC_BLOCK_BITMAP)))
return EXT2_ET_MAGIC_GENERIC_BITMAP;
return 0;
}
errcode_t ext2fs_make_generic_bitmap(errcode_t magic, ext2_filsys fs,
__u32 start, __u32 end, __u32 real_end,
const char *descr, char *init_map,
ext2fs_generic_bitmap *ret)
{
ext2fs_generic_bitmap bitmap;
errcode_t retval;
size_t size;
retval = ext2fs_get_mem(sizeof(struct ext2fs_struct_generic_bitmap),
&bitmap);
if (retval)
return retval;
bitmap->magic = magic;
bitmap->fs = fs;
bitmap->start = start;
bitmap->end = end;
bitmap->real_end = real_end;
switch (magic) {
case EXT2_ET_MAGIC_INODE_BITMAP:
bitmap->base_error_code = EXT2_ET_BAD_INODE_MARK;
break;
case EXT2_ET_MAGIC_BLOCK_BITMAP:
bitmap->base_error_code = EXT2_ET_BAD_BLOCK_MARK;
break;
default:
bitmap->base_error_code = EXT2_ET_BAD_GENERIC_MARK;
}
if (descr) {
retval = ext2fs_get_mem(strlen(descr)+1, &bitmap->description);
if (retval) {
ext2fs_free_mem(&bitmap);
return retval;
}
strcpy(bitmap->description, descr);
} else
bitmap->description = 0;
size = (size_t) (((bitmap->real_end - bitmap->start) / 8) + 1);
/* Round up to allow for the BT x86 instruction */
size = (size + 7) & ~3;
retval = ext2fs_get_mem(size, &bitmap->bitmap);
if (retval) {
ext2fs_free_mem(&bitmap->description);
ext2fs_free_mem(&bitmap);
return retval;
}
if (init_map)
memcpy(bitmap->bitmap, init_map, size);
else
memset(bitmap->bitmap, 0, size);
*ret = bitmap;
return 0;
}
errcode_t ext2fs_allocate_generic_bitmap(__u32 start,
__u32 end,
__u32 real_end,
const char *descr,
ext2fs_generic_bitmap *ret)
{
return ext2fs_make_generic_bitmap(EXT2_ET_MAGIC_GENERIC_BITMAP, 0,
start, end, real_end, descr, 0, ret);
}
errcode_t ext2fs_copy_generic_bitmap(ext2fs_generic_bitmap src,
ext2fs_generic_bitmap *dest)
{
return (ext2fs_make_generic_bitmap(src->magic, src->fs,
src->start, src->end,
src->real_end,
src->description, src->bitmap,
dest));
}
void ext2fs_free_generic_bitmap(ext2fs_inode_bitmap bitmap)
{
if (check_magic(bitmap))
return;
bitmap->magic = 0;
if (bitmap->description) {
ext2fs_free_mem(&bitmap->description);
bitmap->description = 0;
}
if (bitmap->bitmap) {
ext2fs_free_mem(&bitmap->bitmap);
bitmap->bitmap = 0;
}
ext2fs_free_mem(&bitmap);
}
int ext2fs_test_generic_bitmap(ext2fs_generic_bitmap bitmap,
blk_t bitno)
{
if ((bitno < bitmap->start) || (bitno > bitmap->end)) {
ext2fs_warn_bitmap2(bitmap, EXT2FS_TEST_ERROR, bitno);
return 0;
}
return ext2fs_test_bit(bitno - bitmap->start, bitmap->bitmap);
}
int ext2fs_mark_generic_bitmap(ext2fs_generic_bitmap bitmap,
__u32 bitno)
{
if ((bitno < bitmap->start) || (bitno > bitmap->end)) {
ext2fs_warn_bitmap2(bitmap, EXT2FS_MARK_ERROR, bitno);
return 0;
}
return ext2fs_set_bit(bitno - bitmap->start, bitmap->bitmap);
}
int ext2fs_unmark_generic_bitmap(ext2fs_generic_bitmap bitmap,
blk_t bitno)
{
if ((bitno < bitmap->start) || (bitno > bitmap->end)) {
ext2fs_warn_bitmap2(bitmap, EXT2FS_UNMARK_ERROR, bitno);
return 0;
}
return ext2fs_clear_bit(bitno - bitmap->start, bitmap->bitmap);
}
__u32 ext2fs_get_generic_bitmap_start(ext2fs_generic_bitmap bitmap)
{
return bitmap->start;
}
__u32 ext2fs_get_generic_bitmap_end(ext2fs_generic_bitmap bitmap)
{
return bitmap->end;
}
void ext2fs_clear_generic_bitmap(ext2fs_generic_bitmap bitmap)
{
if (check_magic(bitmap))
return;
memset(bitmap->bitmap, 0,
(size_t) (((bitmap->real_end - bitmap->start) / 8) + 1));
}
errcode_t ext2fs_fudge_generic_bitmap_end(ext2fs_inode_bitmap bitmap,
errcode_t magic, errcode_t neq,
ext2_ino_t end, ext2_ino_t *oend)
{
EXT2_CHECK_MAGIC(bitmap, magic);
if (end > bitmap->real_end)
return neq;
if (oend)
*oend = bitmap->end;
bitmap->end = end;
return 0;
}
errcode_t ext2fs_resize_generic_bitmap(errcode_t magic,
__u32 new_end, __u32 new_real_end,
ext2fs_generic_bitmap bmap)
{
errcode_t retval;
size_t size, new_size;
__u32 bitno;
if (!bmap || (bmap->magic != magic))
return magic;
/*
* If we're expanding the bitmap, make sure all of the new
* parts of the bitmap are zero.
*/
if (new_end > bmap->end) {
bitno = bmap->real_end;
if (bitno > new_end)
bitno = new_end;
for (; bitno > bmap->end; bitno--)
ext2fs_clear_bit(bitno - bmap->start, bmap->bitmap);
}
if (new_real_end == bmap->real_end) {
bmap->end = new_end;
return 0;
}
size = ((bmap->real_end - bmap->start) / 8) + 1;
new_size = ((new_real_end - bmap->start) / 8) + 1;
if (size != new_size) {
retval = ext2fs_resize_mem(size, new_size, &bmap->bitmap);
if (retval)
return retval;
}
if (new_size > size)
memset(bmap->bitmap + size, 0, new_size - size);
bmap->end = new_end;
bmap->real_end = new_real_end;
return 0;
}
errcode_t ext2fs_compare_generic_bitmap(errcode_t magic, errcode_t neq,
ext2fs_generic_bitmap bm1,
ext2fs_generic_bitmap bm2)
{
blk_t i;
if (!bm1 || bm1->magic != magic)
return magic;
if (!bm2 || bm2->magic != magic)
return magic;
if ((bm1->start != bm2->start) ||
(bm1->end != bm2->end) ||
(memcmp(bm1->bitmap, bm2->bitmap,
(size_t) (bm1->end - bm1->start)/8)))
return neq;
for (i = bm1->end - ((bm1->end - bm1->start) % 8); i <= bm1->end; i++)
if (ext2fs_fast_test_block_bitmap(bm1, i) !=
ext2fs_fast_test_block_bitmap(bm2, i))
return neq;
return 0;
}
void ext2fs_set_generic_bitmap_padding(ext2fs_generic_bitmap map)
{
__u32 i, j;
/* Protect loop from wrap-around if map->real_end is maxed */
for (i=map->end+1, j = i - map->start;
i <= map->real_end && i > map->end;
i++, j++)
ext2fs_set_bit(j, map->bitmap);
}
errcode_t ext2fs_get_generic_bitmap_range(ext2fs_generic_bitmap bmap,
errcode_t magic,
__u32 start, __u32 num,
void *out)
{
if (!bmap || (bmap->magic != magic))
return magic;
if ((start < bmap->start) || (start+num-1 > bmap->real_end))
return EXT2_ET_INVALID_ARGUMENT;
memcpy(out, bmap->bitmap + (start >> 3), (num+7) >> 3);
return 0;
}
errcode_t ext2fs_set_generic_bitmap_range(ext2fs_generic_bitmap bmap,
errcode_t magic,
__u32 start, __u32 num,
void *in)
{
if (!bmap || (bmap->magic != magic))
return magic;
if ((start < bmap->start) || (start+num-1 > bmap->real_end))
return EXT2_ET_INVALID_ARGUMENT;
memcpy(bmap->bitmap + (start >> 3), in, (num+7) >> 3);
return 0;
}
/*
* Compare @mem to zero buffer by 256 bytes.
* Return 1 if @mem is zeroed memory, otherwise return 0.
*/
static int mem_is_zero(const char *mem, size_t len)
{
static const char zero_buf[256];
while (len >= sizeof(zero_buf)) {
if (memcmp(mem, zero_buf, sizeof(zero_buf)))
return 0;
len -= sizeof(zero_buf);
mem += sizeof(zero_buf);
}
/* Deal with leftover bytes. */
if (len)
return !memcmp(mem, zero_buf, len);
return 1;
}
/*
* Return true if all of the bits in a specified range are clear
*/
static int ext2fs_test_clear_generic_bitmap_range(ext2fs_generic_bitmap bitmap,
unsigned int start,
unsigned int len)
{
size_t start_byte, len_byte = len >> 3;
unsigned int start_bit, len_bit = len % 8;
int first_bit = 0;
int last_bit = 0;
int mark_count = 0;
int mark_bit = 0;
int i;
const char *ADDR = bitmap->bitmap;
start -= bitmap->start;
start_byte = start >> 3;
start_bit = start % 8;
if (start_bit != 0) {
/*
* The compared start block number or start inode number
* is not the first bit in a byte.
*/
mark_count = 8 - start_bit;
if (len < 8 - start_bit) {
mark_count = (int)len;
mark_bit = len + start_bit - 1;
} else
mark_bit = 7;
for (i = mark_count; i > 0; i--, mark_bit--)
first_bit |= 1 << mark_bit;
/*
* Compare blocks or inodes in the first byte.
* If there is any marked bit, this function returns 0.
*/
if (first_bit & ADDR[start_byte])
return 0;
else if (len <= 8 - start_bit)
return 1;
start_byte++;
len_bit = (len - mark_count) % 8;
len_byte = (len - mark_count) >> 3;
}
/*
* The compared start block number or start inode number is
* the first bit in a byte.
*/
if (len_bit != 0) {
/*
* The compared end block number or end inode number is
* not the last bit in a byte.
*/
for (mark_bit = len_bit - 1; mark_bit >= 0; mark_bit--)
last_bit |= 1 << mark_bit;
/*
* Compare blocks or inodes in the last byte.
* If there is any marked bit, this function returns 0.
*/
if (last_bit & ADDR[start_byte + len_byte])
return 0;
else if (len_byte == 0)
return 1;
}
/* Check whether all bytes are 0 */
return mem_is_zero(ADDR + start_byte, len_byte);
}
int ext2fs_test_block_bitmap_range(ext2fs_block_bitmap bitmap,
blk_t block, int num)
{
EXT2_CHECK_MAGIC(bitmap, EXT2_ET_MAGIC_BLOCK_BITMAP);
if ((block < bitmap->start) || (block+num-1 > bitmap->real_end)) {
ext2fs_warn_bitmap(EXT2_ET_BAD_BLOCK_TEST,
block, bitmap->description);
return 0;
}
return ext2fs_test_clear_generic_bitmap_range((ext2fs_generic_bitmap)
bitmap, block, num);
}
int ext2fs_test_inode_bitmap_range(ext2fs_inode_bitmap bitmap,
ino_t inode, int num)
{
EXT2_CHECK_MAGIC(bitmap, EXT2_ET_MAGIC_INODE_BITMAP);
if ((inode < bitmap->start) || (inode+num-1 > bitmap->real_end)) {
ext2fs_warn_bitmap(EXT2_ET_BAD_INODE_TEST,
inode, bitmap->description);
return 0;
}
return ext2fs_test_clear_generic_bitmap_range((ext2fs_generic_bitmap)
bitmap, inode, num);
}
void ext2fs_mark_block_bitmap_range(ext2fs_block_bitmap bitmap,
blk_t block, int num)
{
int i;
if ((block < bitmap->start) || (block+num-1 > bitmap->end)) {
ext2fs_warn_bitmap(EXT2_ET_BAD_BLOCK_MARK, block,
bitmap->description);
return;
}
for (i=0; i < num; i++)
ext2fs_fast_set_bit(block + i - bitmap->start, bitmap->bitmap);
}
void ext2fs_unmark_block_bitmap_range(ext2fs_block_bitmap bitmap,
blk_t block, int num)
{
int i;
if ((block < bitmap->start) || (block+num-1 > bitmap->end)) {
ext2fs_warn_bitmap(EXT2_ET_BAD_BLOCK_UNMARK, block,
bitmap->description);
return;
}
for (i=0; i < num; i++)
ext2fs_fast_clear_bit(block + i - bitmap->start,
bitmap->bitmap);
}