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 <stdio.h>
  13 #if HAVE_UNISTD_H
  14 #include <unistd.h>
  15 #endif
  16 #include <time.h>
  17 #include <string.h>
  18 #if HAVE_SYS_STAT_H
  19 #include <sys/stat.h>
  20 #endif
  21 #if HAVE_SYS_TYPES_H
  22 #include <sys/types.h>
  23 #endif
  24 #include <errno.h>
  25
  26 #include "ext2_fs.h"
  27 #include "ext2fs.h"
  28
  29 errcode_t ext2fs_iblk_add_blocks(ext2_filsys fs, struct ext2_inode *inode,
  30                                  blk64_t num_blocks)
  31 {
  32         unsigned long long b = inode->i_blocks;
  33
  34         if (!(fs->super->s_feature_ro_compat &
  35               EXT4_FEATURE_RO_COMPAT_HUGE_FILE) ||
  36             !(inode->i_flags & EXT4_HUGE_FILE_FL))
  37             num_blocks *= fs->blocksize / 512;
  38
  39         b += num_blocks;
  40
  41         if (fs->super->s_feature_ro_compat &
  42             EXT4_FEATURE_RO_COMPAT_HUGE_FILE) {
  43                 b += ((long long) inode->osd2.linux2.l_i_blocks_hi) << 32;
  44                 inode->osd2.linux2.l_i_blocks_hi = b >> 32;
  45         } else if (b > 0xFFFFFFFF)
  46                 return EOVERFLOW;
  47         inode->i_blocks = b & 0xFFFFFFFF;
  48         return 0;
  49 }
  50
  51 errcode_t ext2fs_iblk_sub_blocks(ext2_filsys fs, struct ext2_inode *inode,
  52                                  blk64_t num_blocks)
  53 {
  54         unsigned long long b = inode->i_blocks;
  55
  56         if (!(fs->super->s_feature_ro_compat &
  57               EXT4_FEATURE_RO_COMPAT_HUGE_FILE) ||
  58             !(inode->i_flags & EXT4_HUGE_FILE_FL))
  59             num_blocks *= fs->blocksize / 512;
  60
  61         if (num_blocks > b)
  62                 return EOVERFLOW;
  63
  64         b -= num_blocks;
  65
  66         if (fs->super->s_feature_ro_compat &
  67             EXT4_FEATURE_RO_COMPAT_HUGE_FILE) {
  68                 b += ((long long) inode->osd2.linux2.l_i_blocks_hi) << 32;
  69                 inode->osd2.linux2.l_i_blocks_hi = b >> 32;
  70         }
  71         inode->i_blocks = b & 0xFFFFFFFF;
  72         return 0;
  73 }
  74
  75 errcode_t ext2fs_iblk_set(ext2_filsys fs, struct ext2_inode *inode, blk64_t b)
  76 {
  77         if (!(fs->super->s_feature_ro_compat &
  78               EXT4_FEATURE_RO_COMPAT_HUGE_FILE) ||
  79             !(inode->i_flags & EXT4_HUGE_FILE_FL))
  80                 b *= fs->blocksize / 512;
  81
  82         inode->i_blocks = b & 0xFFFFFFFF;
  83         if (fs->super->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
  84                 inode->osd2.linux2.l_i_blocks_hi = b >> 32;
  85         else if (b >> 32)
  86                 return EOVERFLOW;
  87         return 0;
  88 }