2023年12月22日发(作者：)

93. snapshot's future use */

94. __le32 s_snapshot_list; /* inode number of the head of the

95. on-disk snapshot list */

96. #define EXT4_S_ERR_START offsetof(structext4_super_block, s_error_count)

97. __le32 s_error_count; /* number of fs errors */

98. __le32 s_first_error_time; /* first time an error happened */

99. __le32 s_first_error_ino; /* inode involved in first error */

100. __le64 s_first_error_block; /* block involved of first error */

101. __u8 s_first_error_func[32]; /*function where the error happened */

102. __le32 s_first_error_line; /* line number where error happened */

103. __le32 s_last_error_time; /* most recent time of an error */

104. __le32 s_last_error_ino; /* inode involved in last error */

105. __le32 s_last_error_line; /* line number where error happened */

106. __le64 s_last_error_block; /* block involved of last error */

107. __u8 s_last_error_func[32]; /*function where the error happened */

108. #define EXT4_S_ERR_END offsetof(structext4_super_block, s_mount_opts)

109. __u8 s_mount_opts[64];

110. __le32 s_reserved[112]; /* Padding to the end of the block */

111. };

group descriptor块组描述信息。包含了blockbitmap、inode bitmap、inode table等存放的块地址。结构体如下：

root@ubuntu:/home/user1# dumpe2fs -h 4dumpe2fs 1.42.9 (4-Feb-2014)Filesystem volume name: Last mounted on: Filesystem UUID: 57f8f4bc-abf4-655f-bf67-946fc0f9f25bFilesystem magic number: 0xEF53Filesystem revision #: 1 (dynamic)Filesystem features: has_journal resize_inode filetype needs_recovery extent sparse_super large_file uninit_bgDefault mount options: (none)Filesystem state: cleanErrors behavior: Remount read-onlyFilesystem OS type: LinuxInode count: 46080Block count: 184320Reserved block count: 0Free blocks: 3382Free inodes: 44404First block: 0Block size: 4096Fragment size: 4096Reserved GDT blocks: 47Blocks per group: 32768Fragments per group: 32768Inodes per group: 7680Inode blocks per group: 480Last mount time: Tue Jul 19 07:59:31 2016Last write time: Tue Jul 19 07:59:31 2016Mount count: 2Maximum mount count: -1Last checked: Wed Dec 31 16:00:00 1969Check interval: 0 ()Reserved blocks uid: 0 (user root)Reserved blocks gid: 0 (group root)First inode: 11Inode size: 256Required extra isize: 28Desired extra isize: 28Journal inode: 8Default directory hash: teaJournal backup: inode blocksJournal features: (none)Journal size: 11MJournal length: 2880Journal sequence: 0x00000004Journal start: 0Reserved GDT blocks: 609Blocks per group: 32768Fragments per group: 32768Inodes per group: 8128Inode blocks per group: 508Flex block group size: 16Filesystem created: Mon May 14 13:30:51 2012Last mount time: Sun Jan 6 18:51:16 2013Last write time: Sun Jan 6 18:51:16 2013Mount count: 282