lib/ext2fs/bitmaps.c

   1 /*
   2  * bitmaps.c --- routines to read, write, and manipulate the inode and
   3  * block bitmaps.
   4  *
   5  * Copyright (C) 1993 Theodore Ts'o.  This file may be redistributed
   6  * under the terms of the GNU Public License.
   7  */
   8
   9 #include <stdio.h>
  10 #include <string.h>
  11 #include <unistd.h>
  12 #include <stdlib.h>
  13 #include <fcntl.h>
  14 #include <time.h>
  15 #include <sys/stat.h>
  16 #include <sys/types.h>
  17
  18 #include <linux/ext2_fs.h>
  19
  20 #include "ext2fs.h"
  21
  22 errcode_t ext2fs_allocate_inode_bitmap(ext2_filsys fs,
  23                                        const char *descr,
  24                                        ext2fs_inode_bitmap *ret)
  25 {
  26         ext2fs_inode_bitmap bitmap;
  27         int     size;
  28
  29         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
  30
  31         fs->write_bitmaps = ext2fs_write_bitmaps;
  32
  33         bitmap = malloc(sizeof(struct ext2fs_struct_inode_bitmap));
  34         if (!bitmap)
  35                 return ENOMEM;
  36
  37         bitmap->magic = EXT2_ET_MAGIC_INODE_BITMAP;
  38         bitmap->fs = fs;
  39         bitmap->start = 1;
  40         bitmap->end = fs->super->s_inodes_count;
  41         bitmap->real_end = (EXT2_INODES_PER_GROUP(fs->super)
  42                             * fs->group_desc_count);
  43         if (descr) {
  44                 bitmap->description = malloc(strlen(descr)+1);
  45                 if (!bitmap->description) {
  46                         free(bitmap);
  47                         return ENOMEM;
  48                 }
  49                 strcpy(bitmap->description, descr);
  50         } else
  51                 bitmap->description = 0;
  52
  53         size = ((bitmap->real_end - bitmap->start) / 8) + 1;
  54         bitmap->bitmap = malloc(size);
  55         if (!bitmap->bitmap) {
  56                 free(bitmap->description);
  57                 free(bitmap);
  58                 return ENOMEM;
  59         }
  60
  61         memset(bitmap->bitmap, 0, size);
  62         *ret = bitmap;
  63         return 0;
  64 }
  65
  66 errcode_t ext2fs_allocate_block_bitmap(ext2_filsys fs,
  67                                        const char *descr,
  68                                        ext2fs_block_bitmap *ret)
  69 {
  70         ext2fs_block_bitmap bitmap;
  71         int     size;
  72
  73         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
  74
  75         fs->write_bitmaps = ext2fs_write_bitmaps;
  76
  77         bitmap = malloc(sizeof(struct ext2fs_struct_inode_bitmap));
  78         if (!bitmap)
  79                 return ENOMEM;
  80
  81         bitmap->magic = EXT2_ET_MAGIC_BLOCK_BITMAP;
  82         bitmap->fs = fs;
  83         bitmap->start = fs->super->s_first_data_block;
  84         bitmap->end = fs->super->s_blocks_count-1;
  85         bitmap->real_end = (EXT2_BLOCKS_PER_GROUP(fs->super)
  86                             * fs->group_desc_count)-1 + bitmap->start;
  87         if (descr) {
  88                 bitmap->description = malloc(strlen(descr)+1);
  89                 if (!bitmap->description) {
  90                         free(bitmap);
  91                         return ENOMEM;
  92                 }
  93                 strcpy(bitmap->description, descr);
  94         } else
  95                 bitmap->description = 0;
  96
  97         size = ((bitmap->real_end - bitmap->start) / 8) + 1;
  98         bitmap->bitmap = malloc(size);
  99         if (!bitmap->bitmap) {
 100                 free(bitmap->description);
 101                 free(bitmap);
 102                 return ENOMEM;
 103         }
 104
 105         memset(bitmap->bitmap, 0, size);
 106         *ret = bitmap;
 107         return 0;
 108 }
 109
 110 errcode_t ext2fs_fudge_inode_bitmap_end(ext2fs_inode_bitmap bitmap,
 111                                         ino_t end, ino_t *oend)
 112 {
 113         EXT2_CHECK_MAGIC(bitmap, EXT2_ET_MAGIC_INODE_BITMAP);
 114
 115         if (end > bitmap->real_end)
 116                 return EXT2_ET_FUDGE_INODE_BITMAP_END;
 117         if (oend)
 118                 *oend = bitmap->end;
 119         bitmap->end = end;
 120         return 0;
 121 }
 122
 123 errcode_t ext2fs_fudge_block_bitmap_end(ext2fs_block_bitmap bitmap,
 124                                         blk_t end, blk_t *oend)
 125 {
 126         EXT2_CHECK_MAGIC(bitmap, EXT2_ET_MAGIC_BLOCK_BITMAP);
 127
 128         if (end > bitmap->real_end)
 129                 return EXT2_ET_FUDGE_BLOCK_BITMAP_END;
 130         if (oend)
 131                 *oend = bitmap->end;
 132         bitmap->end = end;
 133         return 0;
 134 }
 135
 136 void ext2fs_clear_inode_bitmap(ext2fs_inode_bitmap bitmap)
 137 {
 138         if (!bitmap || (bitmap->magic != EXT2_ET_MAGIC_INODE_BITMAP))
 139                 return;
 140
 141         memset(bitmap->bitmap, 0,
 142                ((bitmap->real_end - bitmap->start) / 8) + 1);
 143 }
 144
 145 void ext2fs_clear_block_bitmap(ext2fs_block_bitmap bitmap)
 146 {
 147         if (!bitmap || (bitmap->magic != EXT2_ET_MAGIC_BLOCK_BITMAP))
 148                 return;
 149
 150         memset(bitmap->bitmap, 0,
 151                ((bitmap->real_end - bitmap->start) / 8) + 1);
 152 }
 153
 154 void ext2fs_free_inode_bitmap(ext2fs_inode_bitmap bitmap)
 155 {
 156         if (!bitmap || (bitmap->magic != EXT2_ET_MAGIC_INODE_BITMAP))
 157                 return;
 158
 159         bitmap->magic = 0;
 160         if (bitmap->description) {
 161                 free(bitmap->description);
 162                 bitmap->description = 0;
 163         }
 164         if (bitmap->bitmap) {
 165                 free(bitmap->bitmap);
 166                 bitmap->bitmap = 0;
 167         }
 168         free(bitmap);
 169 }
 170
 171 void ext2fs_free_block_bitmap(ext2fs_block_bitmap bitmap)
 172 {
 173         if (!bitmap || (bitmap->magic != EXT2_ET_MAGIC_BLOCK_BITMAP))
 174                 return;
 175
 176         bitmap->magic = 0;
 177         if (bitmap->description) {
 178                 free(bitmap->description);
 179                 bitmap->description = 0;
 180         }
 181         if (bitmap->bitmap) {
 182                 free(bitmap->bitmap);
 183                 bitmap->bitmap = 0;
 184         }
 185         free(bitmap);
 186 }
 187