CfgUSBLoader/lib/libext2fs/orig/blkmap64_ba.c
2015-01-17 10:11:08 +00:00

328 lines
7.7 KiB
C

/*
* blkmap64_ba.c --- Simple bitarray implementation for bitmaps
*
* Copyright (C) 2008 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>
#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 "ext2fsP.h"
#include "bmap64.h"
/*
* Private data for bit array implementation of bitmap ops.
* Currently, this is just a pointer to our big flat hunk of memory,
* exactly equivalent to the old-skool char * bitmap member.
*/
struct ext2fs_ba_private_struct {
char *bitarray;
};
typedef struct ext2fs_ba_private_struct *ext2fs_ba_private;
static errcode_t ba_alloc_private_data (ext2fs_generic_bitmap bitmap)
{
ext2fs_ba_private bp;
errcode_t retval;
size_t size;
/*
* Since we only have the one pointer, we could just shove our
* private data in the void *private field itself, but then
* we'd have to do a fair bit of rewriting if we ever added a
* field. I'm agnostic.
*/
retval = ext2fs_get_mem(sizeof (ext2fs_ba_private), &bp);
if (retval)
return retval;
size = (size_t) (((bitmap->real_end - bitmap->start) / 8) + 1);
retval = ext2fs_get_mem(size, &bp->bitarray);
if (retval) {
ext2fs_free_mem(&bp);
bp = 0;
return retval;
}
bitmap->private = (void *) bp;
return 0;
}
static errcode_t ba_new_bmap(ext2_filsys fs EXT2FS_ATTR((unused)),
ext2fs_generic_bitmap bitmap)
{
ext2fs_ba_private bp;
errcode_t retval;
size_t size;
retval = ba_alloc_private_data (bitmap);
if (retval)
return retval;
bp = (ext2fs_ba_private) bitmap->private;
size = (size_t) (((bitmap->real_end - bitmap->start) / 8) + 1);
memset(bp->bitarray, 0, size);
return 0;
}
static void ba_free_bmap(ext2fs_generic_bitmap bitmap)
{
ext2fs_ba_private bp = (ext2fs_ba_private) bitmap->private;
if (!bp)
return;
if (bp->bitarray) {
ext2fs_free_mem (&bp->bitarray);
bp->bitarray = 0;
}
ext2fs_free_mem (&bp);
bp = 0;
}
static errcode_t ba_copy_bmap(ext2fs_generic_bitmap src,
ext2fs_generic_bitmap dest)
{
ext2fs_ba_private src_bp = (ext2fs_ba_private) src->private;
ext2fs_ba_private dest_bp;
errcode_t retval;
size_t size;
retval = ba_alloc_private_data (dest);
if (retval)
return retval;
dest_bp = (ext2fs_ba_private) dest->private;
size = (size_t) (((src->real_end - src->start) / 8) + 1);
memcpy (dest_bp->bitarray, src_bp->bitarray, size);
return 0;
}
static errcode_t ba_resize_bmap(ext2fs_generic_bitmap bmap,
__u64 new_end, __u64 new_real_end)
{
ext2fs_ba_private bp = (ext2fs_ba_private) bmap->private;
errcode_t retval;
size_t size, new_size;
__u64 bitno;
/*
* 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_bit64(bitno - bmap->start, bp->bitarray);
}
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, &bp->bitarray);
if (retval)
return retval;
}
if (new_size > size)
memset(bp->bitarray + size, 0, new_size - size);
bmap->end = new_end;
bmap->real_end = new_real_end;
return 0;
}
static int ba_mark_bmap(ext2fs_generic_bitmap bitmap, __u64 arg)
{
ext2fs_ba_private bp = (ext2fs_ba_private) bitmap->private;
blk64_t bitno = (blk64_t) arg;
return ext2fs_set_bit64(bitno - bitmap->start, bp->bitarray);
}
static int ba_unmark_bmap(ext2fs_generic_bitmap bitmap, __u64 arg)
{
ext2fs_ba_private bp = (ext2fs_ba_private) bitmap->private;
blk64_t bitno = (blk64_t) arg;
return ext2fs_clear_bit64(bitno - bitmap->start, bp->bitarray);
}
static int ba_test_bmap(ext2fs_generic_bitmap bitmap, __u64 arg)
{
ext2fs_ba_private bp = (ext2fs_ba_private) bitmap->private;
blk64_t bitno = (blk64_t) arg;
return ext2fs_test_bit64(bitno - bitmap->start, bp->bitarray);
}
static void ba_mark_bmap_extent(ext2fs_generic_bitmap bitmap, __u64 arg,
unsigned int num)
{
ext2fs_ba_private bp = (ext2fs_ba_private) bitmap->private;
blk64_t bitno = (blk64_t) arg;
unsigned int i;
for (i = 0; i < num; i++)
ext2fs_fast_set_bit64(bitno + i - bitmap->start, bp->bitarray);
}
static void ba_unmark_bmap_extent(ext2fs_generic_bitmap bitmap, __u64 arg,
unsigned int num)
{
ext2fs_ba_private bp = (ext2fs_ba_private) bitmap->private;
blk64_t bitno = (blk64_t) arg;
unsigned int i;
for (i = 0; i < num; i++)
ext2fs_fast_clear_bit64(bitno + i - bitmap->start, bp->bitarray);
}
static int ba_test_clear_bmap_extent(ext2fs_generic_bitmap bitmap,
__u64 start, unsigned int len)
{
ext2fs_ba_private bp = (ext2fs_ba_private) bitmap->private;
__u64 start_byte, len_byte = len >> 3;
unsigned int start_bit, len_bit = len % 8;
unsigned int first_bit = 0;
unsigned int last_bit = 0;
int mark_count = 0;
int mark_bit = 0;
int i;
const char *ADDR;
ADDR = bp->bitarray;
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 ext2fs_mem_is_zero(ADDR + start_byte, len_byte);
}
static errcode_t ba_set_bmap_range(ext2fs_generic_bitmap bitmap,
__u64 start, size_t num, void *in)
{
ext2fs_ba_private bp = (ext2fs_ba_private) bitmap->private;
memcpy (bp->bitarray + (start >> 3), in, (num + 7) >> 3);
return 0;
}
static errcode_t ba_get_bmap_range(ext2fs_generic_bitmap bitmap,
__u64 start, size_t num, void *out)
{
ext2fs_ba_private bp = (ext2fs_ba_private) bitmap->private;
memcpy (out, bp->bitarray + (start >> 3), (num + 7) >> 3);
return 0;
}
static void ba_clear_bmap(ext2fs_generic_bitmap bitmap)
{
ext2fs_ba_private bp = (ext2fs_ba_private) bitmap->private;
memset(bp->bitarray, 0,
(size_t) (((bitmap->real_end - bitmap->start) / 8) + 1));
}
struct ext2_bitmap_ops ext2fs_blkmap64_bitarray = {
.type = EXT2FS_BMAP64_BITARRAY,
.new_bmap = ba_new_bmap,
.free_bmap = ba_free_bmap,
.copy_bmap = ba_copy_bmap,
.resize_bmap = ba_resize_bmap,
.mark_bmap = ba_mark_bmap,
.unmark_bmap = ba_unmark_bmap,
.test_bmap = ba_test_bmap,
.test_clear_bmap_extent = ba_test_clear_bmap_extent,
.mark_bmap_extent = ba_mark_bmap_extent,
.unmark_bmap_extent = ba_unmark_bmap_extent,
.set_bmap_range = ba_set_bmap_range,
.get_bmap_range = ba_get_bmap_range,
.clear_bmap = ba_clear_bmap,
};