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 & EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
  35                 b += ((long long) inode->osd2.linux2.l_i_blocks_hi) << 32;
  36
  37         if (!(fs->super->s_feature_ro_compat &
  38               EXT4_FEATURE_RO_COMPAT_HUGE_FILE) ||
  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 (fs->super->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
  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 (fs->super->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
  59                 b += ((long long) inode->osd2.linux2.l_i_blocks_hi) << 32;
  60
  61         if (!(fs->super->s_feature_ro_compat &
  62               EXT4_FEATURE_RO_COMPAT_HUGE_FILE) ||
  63             !(inode->i_flags & EXT4_HUGE_FILE_FL))
  64             num_blocks *= fs->blocksize / 512;
  65         num_blocks *= EXT2FS_CLUSTER_RATIO(fs);
  66
  67         if (num_blocks > b)
  68                 return EOVERFLOW;
  69
  70         b -= num_blocks;
  71
  72         if (fs->super->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
  73                 inode->osd2.linux2.l_i_blocks_hi = b >> 32;
  74         inode->i_blocks = b & 0xFFFFFFFF;
  75         return 0;
  76 }
  77
  78 errcode_t ext2fs_iblk_set(ext2_filsys fs, struct ext2_inode *inode, blk64_t b)
  79 {
  80         if (!(fs->super->s_feature_ro_compat &
  81               EXT4_FEATURE_RO_COMPAT_HUGE_FILE) ||
  82             !(inode->i_flags & EXT4_HUGE_FILE_FL))
  83                 b *= fs->blocksize / 512;
  84         b *= EXT2FS_CLUSTER_RATIO(fs);
  85
  86         inode->i_blocks = b & 0xFFFFFFFF;
  87         if (fs->super->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
  88                 inode->osd2.linux2.l_i_blocks_hi = b >> 32;
  89         else if (b >> 32)
  90                 return EOVERFLOW;
  91         return 0;
  92 }