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 (fs->super->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
  36                 b += ((long long) inode->osd2.linux2.l_i_blocks_hi) << 32;
  37
  38         if (!(fs->super->s_feature_ro_compat &
  39               EXT4_FEATURE_RO_COMPAT_HUGE_FILE) ||
  40             !(inode->i_flags & EXT4_HUGE_FILE_FL))
  41             num_blocks *= fs->blocksize / 512;
  42         num_blocks *= EXT2FS_CLUSTER_RATIO(fs);
  43
  44         b += num_blocks;
  45
  46         if (fs->super->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
  47                 inode->osd2.linux2.l_i_blocks_hi = b >> 32;
  48         else if (b > 0xFFFFFFFF)
  49                 return EOVERFLOW;
  50         inode->i_blocks = b & 0xFFFFFFFF;
  51         return 0;
  52 }
  53
  54 errcode_t ext2fs_iblk_sub_blocks(ext2_filsys fs, struct ext2_inode *inode,
  55                                  blk64_t num_blocks)
  56 {
  57         unsigned long long b = inode->i_blocks;
  58
  59         if (fs->super->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
  60                 b += ((long long) inode->osd2.linux2.l_i_blocks_hi) << 32;
  61
  62         if (!(fs->super->s_feature_ro_compat &
  63               EXT4_FEATURE_RO_COMPAT_HUGE_FILE) ||
  64             !(inode->i_flags & EXT4_HUGE_FILE_FL))
  65             num_blocks *= fs->blocksize / 512;
  66         num_blocks *= EXT2FS_CLUSTER_RATIO(fs);
  67
  68         if (num_blocks > b)
  69                 return EOVERFLOW;
  70
  71         b -= num_blocks;
  72
  73         if (fs->super->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
  74                 inode->osd2.linux2.l_i_blocks_hi = b >> 32;
  75         inode->i_blocks = b & 0xFFFFFFFF;
  76         return 0;
  77 }
  78
  79 errcode_t ext2fs_iblk_set(ext2_filsys fs, struct ext2_inode *inode, blk64_t b)
  80 {
  81         if (!(fs->super->s_feature_ro_compat &
  82               EXT4_FEATURE_RO_COMPAT_HUGE_FILE) ||
  83             !(inode->i_flags & EXT4_HUGE_FILE_FL))
  84                 b *= fs->blocksize / 512;
  85         b *= EXT2FS_CLUSTER_RATIO(fs);
  86
  87         inode->i_blocks = b & 0xFFFFFFFF;
  88         if (fs->super->s_feature_ro_compat & EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
  89                 inode->osd2.linux2.l_i_blocks_hi = b >> 32;
  90         else if (b >> 32)
  91                 return EOVERFLOW;
  92         return 0;
  93 }