docs-add-new-ext4-superblock-time-extension-fields

   1 docs: add new ext4 superblock time extension fields
   2
   3 From: Darrick J. Wong <darrick.wong@oracle.com>
   4
   5 The superblock timestamp fields were enlarged by u8 to be 40 bits wide.
   6 Update the documentation to reflect this.
   7
   8 Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
   9 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
  10 ---
  11  Documentation/filesystems/ext4/ondisk/super.rst |   32 ++++++++++++++++++++++-
  12  1 file changed, 30 insertions(+), 2 deletions(-)
  13
  14
  15 diff --git a/Documentation/filesystems/ext4/ondisk/super.rst b/Documentation/filesystems/ext4/ondisk/super.rst
  16 index 1f5ac9ab6f0c..5f81dd87e0b9 100644
  17 --- a/Documentation/filesystems/ext4/ondisk/super.rst
  18 +++ b/Documentation/filesystems/ext4/ondisk/super.rst
  19 @@ -442,8 +442,36 @@ The ext4 superblock is laid out as follows in
  20       - Checksum seed used for metadata\_csum calculations. This value is
  21         crc32c(~0, $orig\_fs\_uuid).
  22     * - 0x274
  23 -     - \_\_le32
  24 -     - s\_reserved[98]
  25 +     - \_\_u8
  26 +     - s\_wtime_hi
  27 +     - Upper 8 bits of the s_wtime field.
  28 +   * - 0x275
  29 +     - \_\_u8
  30 +     - s\_wtime_hi
  31 +     - Upper 8 bits of the s_mtime field.
  32 +   * - 0x276
  33 +     - \_\_u8
  34 +     - s\_mkfs_time_hi
  35 +     - Upper 8 bits of the s_mkfs_time field.
  36 +   * - 0x277
  37 +     - \_\_u8
  38 +     - s\_lastcheck_hi
  39 +     - Upper 8 bits of the s_lastcheck_hi field.
  40 +   * - 0x278
  41 +     - \_\_u8
  42 +     - s\_first_error_time_hi
  43 +     - Upper 8 bits of the s_first_error_time_hi field.
  44 +   * - 0x279
  45 +     - \_\_u8
  46 +     - s\_last_error_time_hi
  47 +     - Upper 8 bits of the s_last_error_time_hi field.
  48 +   * - 0x27A
  49 +     - \_\_u8[2]
  50 +     - s\_pad
  51 +     - Zero padding.
  52 +   * - 0x27C
  53 +     - \_\_le32
  54 +     - s\_reserved[96]
  55       - Padding to the end of the block.
  56     * - 0x3FC
  57       - \_\_le32
  58
  59