lib/ext2fs/rs_bitmap.c

   1 /*
   2  * rs_bitmap.c --- routine for changing the size of a bitmap
   3  *
   4  * Copyright (C) 1996, 1997 Theodore Ts'o.
   5  *
   6  * %Begin-Header%
   7  * This file may be redistributed under the terms of the GNU Public
   8  * License.
   9  * %End-Header%
  10  */
  11
  12 #include <stdio.h>
  13 #include <string.h>
  14 #if HAVE_UNISTD_H
  15 #include <unistd.h>
  16 #endif
  17 #include <fcntl.h>
  18 #include <time.h>
  19 #ifdef HAVE_SYS_STAT_H
  20 #include <sys/stat.h>
  21 #endif
  22 #ifdef HAVE_SYS_TYPES_H
  23 #include <sys/types.h>
  24 #endif
  25
  26 #include "ext2_fs.h"
  27 #include "ext2fs.h"
  28
  29 errcode_t ext2fs_resize_generic_bitmap(__u32 new_end, __u32 new_real_end,
  30                                        ext2fs_generic_bitmap bmap)
  31 {
  32         errcode_t       retval;
  33         size_t          size, new_size;
  34         __u32           bitno;
  35
  36         if (!bmap)
  37                 return EXT2_ET_INVALID_ARGUMENT;
  38
  39         EXT2_CHECK_MAGIC(bmap, EXT2_ET_MAGIC_GENERIC_BITMAP);
  40
  41         /*
  42          * If we're expanding the bitmap, make sure all of the new
  43          * parts of the bitmap are zero.
  44          */
  45         if (new_end > bmap->end) {
  46                 bitno = bmap->real_end;
  47                 if (bitno > new_end)
  48                         bitno = new_end;
  49                 for (; bitno > bmap->end; bitno--)
  50                         ext2fs_clear_bit(bitno - bmap->start, bmap->bitmap);
  51         }
  52         if (new_real_end == bmap->real_end) {
  53                 bmap->end = new_end;
  54                 return 0;
  55         }
  56
  57         size = ((bmap->real_end - bmap->start) / 8) + 1;
  58         new_size = ((new_real_end - bmap->start) / 8) + 1;
  59
  60         if (size != new_size) {
  61                 retval = ext2fs_resize_mem(size, new_size,
  62                                            (void **) &bmap->bitmap);
  63                 if (retval)
  64                         return retval;
  65         }
  66         if (new_size > size)
  67                 memset(bmap->bitmap + size, 0, new_size - size);
  68
  69         bmap->end = new_end;
  70         bmap->real_end = new_real_end;
  71         return 0;
  72 }
  73
  74 errcode_t ext2fs_resize_inode_bitmap(__u32 new_end, __u32 new_real_end,
  75                                      ext2fs_inode_bitmap bmap)
  76 {
  77         errcode_t       retval;
  78
  79         if (!bmap)
  80                 return EXT2_ET_INVALID_ARGUMENT;
  81
  82         EXT2_CHECK_MAGIC(bmap, EXT2_ET_MAGIC_INODE_BITMAP);
  83
  84         bmap->magic = EXT2_ET_MAGIC_GENERIC_BITMAP;
  85         retval = ext2fs_resize_generic_bitmap(new_end, new_real_end,
  86                                               bmap);
  87         bmap->magic = EXT2_ET_MAGIC_INODE_BITMAP;
  88         return retval;
  89 }
  90
  91 errcode_t ext2fs_resize_block_bitmap(__u32 new_end, __u32 new_real_end,
  92                                      ext2fs_block_bitmap bmap)
  93 {
  94         errcode_t       retval;
  95
  96         if (!bmap)
  97                 return EXT2_ET_INVALID_ARGUMENT;
  98
  99         EXT2_CHECK_MAGIC(bmap, EXT2_ET_MAGIC_BLOCK_BITMAP);
 100
 101         bmap->magic = EXT2_ET_MAGIC_GENERIC_BITMAP;
 102         retval = ext2fs_resize_generic_bitmap(new_end, new_real_end,
 103                                               bmap);
 104         bmap->magic = EXT2_ET_MAGIC_BLOCK_BITMAP;
 105         return retval;
 106 }
 107