ext4_sb.c

   1 /*
   2  * Copyright (C) 2014 The Android Open Source Project
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *      http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include <errno.h>
  18
  19 #include "ext4_sb.h"
  20
  21 int ext4_parse_sb(struct ext4_super_block *sb, struct fs_info *info)
  22 {
  23         uint64_t len_blocks;
  24
  25         if (sb->s_magic != EXT4_SUPER_MAGIC)
  26                 return -EINVAL;
  27
  28         if ((sb->s_state & EXT4_VALID_FS) != EXT4_VALID_FS)
  29                 return -EINVAL;
  30
  31         info->block_size = 1024 << sb->s_log_block_size;
  32         info->blocks_per_group = sb->s_blocks_per_group;
  33         info->inodes_per_group = sb->s_inodes_per_group;
  34         info->inode_size = sb->s_inode_size;
  35         info->inodes = sb->s_inodes_count;
  36         info->feat_ro_compat = sb->s_feature_ro_compat;
  37         info->feat_compat = sb->s_feature_compat;
  38         info->feat_incompat = sb->s_feature_incompat;
  39         info->bg_desc_reserve_blocks = sb->s_reserved_gdt_blocks;
  40         info->label = sb->s_volume_name;
  41
  42         len_blocks = ((uint64_t)sb->s_blocks_count_hi << 32) +
  43                 sb->s_blocks_count_lo;
  44         info->len = (uint64_t)info->block_size * len_blocks;
  45
  46         return 0;
  47 }