lib/ext2fs/i_block.c

   1 /*
   2  * i_block.c --- Manage the i_block field for i_blocks
   3  *
   4  * Copyright (C) 2008 Theodore Ts'o.
   5  *
   6  * %Begin-Header%
   7  * This file may be redistributed under the terms of the GNU Library
   8  * General Public License, version 2.
   9  * %End-Header%
  10  */
  11
  12 #include "config.h"
  13 #include <stdio.h>
  14 #if HAVE_UNISTD_H
  15 #include <unistd.h>
  16 #endif
  17 #include <time.h>
  18 #include <string.h>
  19 #if HAVE_SYS_STAT_H
  20 #include <sys/stat.h>
  21 #endif
  22 #if HAVE_SYS_TYPES_H
  23 #include <sys/types.h>
  24 #endif
  25 #include <errno.h>
  26
  27 #include "ext2_fs.h"
  28 #include "ext2fs.h"
  29
  30 errcode_t ext2fs_iblk_add_blocks(ext2_filsys fs, struct ext2_inode *inode,
  31                                  blk64_t num_blocks)
  32 {
  33         unsigned long long b = inode->i_blocks;
  34
  35         if (ext2fs_has_feature_huge_file(fs->super))
  36                 b += ((long long) inode->osd2.linux2.l_i_blocks_hi) << 32;
  37
  38         if (!ext2fs_has_feature_huge_file(fs->super) ||
  39             !(inode->i_flags & EXT4_HUGE_FILE_FL))
  40             num_blocks *= fs->blocksize / 512;
  41         num_blocks *= EXT2FS_CLUSTER_RATIO(fs);
  42
  43         b += num_blocks;
  44
  45         if (ext2fs_has_feature_huge_file(fs->super))
  46                 inode->osd2.linux2.l_i_blocks_hi = b >> 32;
  47         else if (b > 0xFFFFFFFF)
  48                 return EOVERFLOW;
  49         inode->i_blocks = b & 0xFFFFFFFF;
  50         return 0;
  51 }
  52
  53 errcode_t ext2fs_iblk_sub_blocks(ext2_filsys fs, struct ext2_inode *inode,
  54                                  blk64_t num_blocks)
  55 {
  56         unsigned long long b = inode->i_blocks;
  57
  58         if (ext2fs_has_feature_huge_file(fs->super))
  59                 b += ((long long) inode->osd2.linux2.l_i_blocks_hi) << 32;
  60
  61         if (!ext2fs_has_feature_huge_file(fs->super) ||
  62             !(inode->i_flags & EXT4_HUGE_FILE_FL))
  63             num_blocks *= fs->blocksize / 512;
  64         num_blocks *= EXT2FS_CLUSTER_RATIO(fs);
  65
  66         if (num_blocks > b)
  67                 return EOVERFLOW;
  68
  69         b -= num_blocks;
  70
  71         if (ext2fs_has_feature_huge_file(fs->super))
  72                 inode->osd2.linux2.l_i_blocks_hi = b >> 32;
  73         inode->i_blocks = b & 0xFFFFFFFF;
  74         return 0;
  75 }
  76
  77 errcode_t ext2fs_iblk_set(ext2_filsys fs, struct ext2_inode *inode, blk64_t b)
  78 {
  79         if (!ext2fs_has_feature_huge_file(fs->super) ||
  80             !(inode->i_flags & EXT4_HUGE_FILE_FL))
  81                 b *= fs->blocksize / 512;
  82         b *= EXT2FS_CLUSTER_RATIO(fs);
  83
  84         inode->i_blocks = b & 0xFFFFFFFF;
  85         if (ext2fs_has_feature_huge_file(fs->super))
  86                 inode->osd2.linux2.l_i_blocks_hi = b >> 32;
  87         else if (b >> 32)
  88                 return EOVERFLOW;
  89         return 0;
  90 }