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-rw-r--r--lib/ext2fs/gen_bitmap.c650
1 files changed, 650 insertions, 0 deletions
diff --git a/lib/ext2fs/gen_bitmap.c b/lib/ext2fs/gen_bitmap.c
new file mode 100644
index 0000000..1536d4b
--- /dev/null
+++ b/lib/ext2fs/gen_bitmap.c
@@ -0,0 +1,650 @@
+/*
+ * 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 "config.h"
+#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"
+
+struct ext2fs_struct_generic_bitmap_32 {
+ errcode_t magic;
+ ext2_filsys fs;
+ __u32 start, end;
+ __u32 real_end;
+ char * description;
+ char * bitmap;
+ errcode_t base_error_code;
+ __u32 reserved[7];
+};
+
+typedef struct ext2fs_struct_generic_bitmap_32 *ext2fs_generic_bitmap_32;
+
+#define EXT2FS_IS_32_BITMAP(bmap) \
+ (((bmap)->magic == EXT2_ET_MAGIC_GENERIC_BITMAP) || \
+ ((bmap)->magic == EXT2_ET_MAGIC_BLOCK_BITMAP) || \
+ ((bmap)->magic == EXT2_ET_MAGIC_INODE_BITMAP))
+
+#define EXT2FS_IS_64_BITMAP(bmap) \
+ (((bmap)->magic == EXT2_ET_MAGIC_GENERIC_BITMAP64) || \
+ ((bmap)->magic == EXT2_ET_MAGIC_BLOCK_BITMAP64) || \
+ ((bmap)->magic == EXT2_ET_MAGIC_INODE_BITMAP64))
+
+/*
+ * Used by previously inlined function, so we have to export this and
+ * not change the function signature
+ */
+void ext2fs_warn_bitmap2(ext2fs_generic_bitmap gen_bitmap,
+ int code, unsigned long arg)
+{
+ ext2fs_generic_bitmap_32 bitmap = (ext2fs_generic_bitmap_32) gen_bitmap;
+
+#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_32 bitmap;
+ errcode_t retval;
+ size_t size;
+
+ retval = ext2fs_get_mem(sizeof(struct ext2fs_struct_generic_bitmap_32),
+ &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 = (ext2fs_generic_bitmap) 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 gen_src,
+ ext2fs_generic_bitmap *dest)
+{
+ ext2fs_generic_bitmap_32 src = (ext2fs_generic_bitmap_32) gen_src;
+
+ 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 gen_bitmap)
+{
+ ext2fs_generic_bitmap_32 bitmap = (ext2fs_generic_bitmap_32) gen_bitmap;
+
+ if (check_magic(gen_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)
+{
+ ext2fs_generic_bitmap_32 bitmap32 = (ext2fs_generic_bitmap_32) bitmap;
+
+ if (!EXT2FS_IS_32_BITMAP(bitmap)) {
+ if (EXT2FS_IS_64_BITMAP(bitmap)) {
+ ext2fs_warn_bitmap32(bitmap, __func__);
+ return ext2fs_test_generic_bmap(bitmap, bitno);
+ }
+#ifndef OMIT_COM_ERR
+ com_err(0, EXT2_ET_MAGIC_GENERIC_BITMAP,
+ "test_bitmap(%lu)", (unsigned long) bitno);
+#endif
+ return 0;
+ }
+
+ if ((bitno < bitmap32->start) || (bitno > bitmap32->end)) {
+ ext2fs_warn_bitmap2(bitmap, EXT2FS_TEST_ERROR, bitno);
+ return 0;
+ }
+ return ext2fs_test_bit(bitno - bitmap32->start, bitmap32->bitmap);
+}
+
+int ext2fs_mark_generic_bitmap(ext2fs_generic_bitmap bitmap,
+ __u32 bitno)
+{
+ ext2fs_generic_bitmap_32 bitmap32 = (ext2fs_generic_bitmap_32) bitmap;
+
+ if (!EXT2FS_IS_32_BITMAP(bitmap)) {
+ if (EXT2FS_IS_64_BITMAP(bitmap)) {
+ ext2fs_warn_bitmap32(bitmap, __func__);
+ return ext2fs_mark_generic_bmap(bitmap, bitno);
+ }
+#ifndef OMIT_COM_ERR
+ com_err(0, EXT2_ET_MAGIC_GENERIC_BITMAP,
+ "mark_bitmap(%lu)", (unsigned long) bitno);
+#endif
+ return 0;
+ }
+
+ if ((bitno < bitmap32->start) || (bitno > bitmap32->end)) {
+ ext2fs_warn_bitmap2(bitmap, EXT2FS_MARK_ERROR, bitno);
+ return 0;
+ }
+ return ext2fs_set_bit(bitno - bitmap32->start, bitmap32->bitmap);
+}
+
+int ext2fs_unmark_generic_bitmap(ext2fs_generic_bitmap bitmap,
+ blk_t bitno)
+{
+ ext2fs_generic_bitmap_32 bitmap32 = (ext2fs_generic_bitmap_32) bitmap;
+
+ if (!EXT2FS_IS_32_BITMAP(bitmap)) {
+ if (EXT2FS_IS_64_BITMAP(bitmap)) {
+ ext2fs_warn_bitmap32(bitmap, __func__);
+ return ext2fs_unmark_generic_bmap(bitmap, bitno);
+ }
+#ifndef OMIT_COM_ERR
+ com_err(0, EXT2_ET_MAGIC_GENERIC_BITMAP,
+ "mark_bitmap(%lu)", (unsigned long) bitno);
+#endif
+ return 0;
+ }
+
+ if ((bitno < bitmap32->start) || (bitno > bitmap32->end)) {
+ ext2fs_warn_bitmap2(bitmap, EXT2FS_UNMARK_ERROR, bitno);
+ return 0;
+ }
+ return ext2fs_clear_bit(bitno - bitmap32->start, bitmap32->bitmap);
+}
+
+__u32 ext2fs_get_generic_bitmap_start(ext2fs_generic_bitmap bitmap)
+{
+ ext2fs_generic_bitmap_32 bitmap32 = (ext2fs_generic_bitmap_32) bitmap;
+
+ if (!EXT2FS_IS_32_BITMAP(bitmap)) {
+ if (EXT2FS_IS_64_BITMAP(bitmap)) {
+ ext2fs_warn_bitmap32(bitmap, __func__);
+ return ext2fs_get_generic_bmap_start(bitmap);
+ }
+#ifndef OMIT_COM_ERR
+ com_err(0, EXT2_ET_MAGIC_GENERIC_BITMAP,
+ "get_bitmap_start");
+#endif
+ return 0;
+ }
+
+ return bitmap32->start;
+}
+
+__u32 ext2fs_get_generic_bitmap_end(ext2fs_generic_bitmap bitmap)
+{
+ ext2fs_generic_bitmap_32 bitmap32 = (ext2fs_generic_bitmap_32) bitmap;
+
+ if (!EXT2FS_IS_32_BITMAP(bitmap)) {
+ if (EXT2FS_IS_64_BITMAP(bitmap)) {
+ ext2fs_warn_bitmap32(bitmap, __func__);
+ return ext2fs_get_generic_bmap_end(bitmap);
+ }
+#ifndef OMIT_COM_ERR
+ com_err(0, EXT2_ET_MAGIC_GENERIC_BITMAP,
+ "get_bitmap_end");
+#endif
+ return 0;
+ }
+ return bitmap32->end;
+}
+
+void ext2fs_clear_generic_bitmap(ext2fs_generic_bitmap bitmap)
+{
+ ext2fs_generic_bitmap_32 bitmap32 = (ext2fs_generic_bitmap_32) bitmap;
+
+ if (!EXT2FS_IS_32_BITMAP(bitmap)) {
+ if (EXT2FS_IS_64_BITMAP(bitmap)) {
+ ext2fs_warn_bitmap32(bitmap, __func__);
+ ext2fs_clear_generic_bmap(bitmap);
+ return;
+ }
+#ifndef OMIT_COM_ERR
+ com_err(0, EXT2_ET_MAGIC_GENERIC_BITMAP,
+ "clear_generic_bitmap");
+#endif
+ return;
+ }
+
+ memset(bitmap32->bitmap, 0,
+ (size_t) (((bitmap32->real_end - bitmap32->start) / 8) + 1));
+}
+
+errcode_t ext2fs_fudge_generic_bitmap_end(ext2fs_inode_bitmap gen_bitmap,
+ errcode_t magic, errcode_t neq,
+ ext2_ino_t end, ext2_ino_t *oend)
+{
+ ext2fs_generic_bitmap_32 bitmap = (ext2fs_generic_bitmap_32) gen_bitmap;
+
+ 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 gen_bmap)
+{
+ ext2fs_generic_bitmap_32 bmap = (ext2fs_generic_bitmap_32) gen_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 gen_bm1,
+ ext2fs_generic_bitmap gen_bm2)
+{
+ ext2fs_generic_bitmap_32 bm1 = (ext2fs_generic_bitmap_32) gen_bm1;
+ ext2fs_generic_bitmap_32 bm2 = (ext2fs_generic_bitmap_32) gen_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(gen_bm1, i) !=
+ ext2fs_fast_test_block_bitmap(gen_bm2, i))
+ return neq;
+
+ return 0;
+}
+
+void ext2fs_set_generic_bitmap_padding(ext2fs_generic_bitmap gen_map)
+{
+ ext2fs_generic_bitmap_32 map = (ext2fs_generic_bitmap_32) gen_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 gen_bmap,
+ errcode_t magic,
+ __u32 start, __u32 num,
+ void *out)
+{
+ ext2fs_generic_bitmap_32 bmap = (ext2fs_generic_bitmap_32) gen_bmap;
+
+ 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 - bmap->start) >> 3), (num+7) >> 3);
+ return 0;
+}
+
+errcode_t ext2fs_set_generic_bitmap_range(ext2fs_generic_bitmap gen_bmap,
+ errcode_t magic,
+ __u32 start, __u32 num,
+ void *in)
+{
+ ext2fs_generic_bitmap_32 bmap = (ext2fs_generic_bitmap_32) gen_bmap;
+
+ 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 - bmap->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.
+ */
+int ext2fs_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 gen_bitmap,
+ unsigned int start,
+ unsigned int len)
+{
+ ext2fs_generic_bitmap_32 bitmap = (ext2fs_generic_bitmap_32) gen_bitmap;
+ 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 ext2fs_mem_is_zero(ADDR + start_byte, len_byte);
+}
+
+errcode_t ext2fs_find_first_zero_generic_bitmap(ext2fs_generic_bitmap gen_bitmap,
+ __u32 start, __u32 end,
+ __u32 *out)
+{
+ ext2fs_generic_bitmap_32 bitmap = (ext2fs_generic_bitmap_32) gen_bitmap;
+ blk_t b;
+
+ if (start < bitmap->start || end > bitmap->end || start > end) {
+ ext2fs_warn_bitmap2(gen_bitmap, EXT2FS_TEST_ERROR, start);
+ return EINVAL;
+ }
+
+ while (start <= end) {
+ b = ext2fs_test_bit(start - bitmap->start, bitmap->bitmap);
+ if (!b) {
+ *out = start;
+ return 0;
+ }
+ start++;
+ }
+
+ return ENOENT;
+}
+
+errcode_t ext2fs_find_first_set_generic_bitmap(ext2fs_generic_bitmap gen_bitmap,
+ __u32 start, __u32 end,
+ __u32 *out)
+{
+ ext2fs_generic_bitmap_32 bitmap = (ext2fs_generic_bitmap_32) gen_bitmap;
+ blk_t b;
+
+ if (start < bitmap->start || end > bitmap->end || start > end) {
+ ext2fs_warn_bitmap2(gen_bitmap, EXT2FS_TEST_ERROR, start);
+ return EINVAL;
+ }
+
+ while (start <= end) {
+ b = ext2fs_test_bit(start - bitmap->start, bitmap->bitmap);
+ if (b) {
+ *out = start;
+ return 0;
+ }
+ start++;
+ }
+
+ return ENOENT;
+}
+
+int ext2fs_test_block_bitmap_range(ext2fs_block_bitmap gen_bitmap,
+ blk_t block, int num)
+{
+ ext2fs_generic_bitmap_32 bitmap = (ext2fs_generic_bitmap_32) gen_bitmap;
+
+ EXT2_CHECK_MAGIC(bitmap, EXT2_ET_MAGIC_BLOCK_BITMAP);
+ if ((block < bitmap->start) || (block > bitmap->real_end) ||
+ (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 gen_bitmap,
+ ext2_ino_t inode, int num)
+{
+ ext2fs_generic_bitmap_32 bitmap = (ext2fs_generic_bitmap_32) gen_bitmap;
+
+ EXT2_CHECK_MAGIC(bitmap, EXT2_ET_MAGIC_INODE_BITMAP);
+ if ((inode < bitmap->start) || (inode > bitmap->real_end) ||
+ (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 gen_bitmap,
+ blk_t block, int num)
+{
+ ext2fs_generic_bitmap_32 bitmap = (ext2fs_generic_bitmap_32) gen_bitmap;
+ int i;
+
+ if ((block < bitmap->start) || (block > bitmap->end) ||
+ (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 gen_bitmap,
+ blk_t block, int num)
+{
+ ext2fs_generic_bitmap_32 bitmap = (ext2fs_generic_bitmap_32) gen_bitmap;
+ int i;
+
+ if ((block < bitmap->start) || (block > bitmap->end) ||
+ (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);
+}
+