linux/Documentation/filesystems/ext4/blockmap.rst
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   1.. SPDX-License-Identifier: GPL-2.0
   2
   3+---------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   4| i.i\_block Offset   | Where It Points                                                                                                                                                                                                              |
   5+=====================+==============================================================================================================================================================================================================================+
   6| 0 to 11             | Direct map to file blocks 0 to 11.                                                                                                                                                                                           |
   7+---------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   8| 12                  | Indirect block: (file blocks 12 to (``$block_size`` / 4) + 11, or 12 to 1035 if 4KiB blocks)                                                                                                                                 |
   9|                     |                                                                                                                                                                                                                              |
  10|                     | +------------------------------+--------------------------------------------------------------------+                                                                                                                        |
  11|                     | | Indirect Block Offset        | Where It Points                                                    |                                                                                                                        |
  12|                     | +==============================+====================================================================+                                                                                                                        |
  13|                     | | 0 to (``$block_size`` / 4)   | Direct map to (``$block_size`` / 4) blocks (1024 if 4KiB blocks)   |                                                                                                                        |
  14|                     | +------------------------------+--------------------------------------------------------------------+                                                                                                                        |
  15+---------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
  16| 13                  | Double-indirect block: (file blocks ``$block_size``/4 + 12 to (``$block_size`` / 4) ^ 2 + (``$block_size`` / 4) + 11, or 1036 to 1049611 if 4KiB blocks)                                                                     |
  17|                     |                                                                                                                                                                                                                              |
  18|                     | +--------------------------------+---------------------------------------------------------------------------------------------------------+                                                                                 |
  19|                     | | Double Indirect Block Offset   | Where It Points                                                                                         |                                                                                 |
  20|                     | +================================+=========================================================================================================+                                                                                 |
  21|                     | | 0 to (``$block_size`` / 4)     | Map to (``$block_size`` / 4) indirect blocks (1024 if 4KiB blocks)                                      |                                                                                 |
  22|                     | |                                |                                                                                                         |                                                                                 |
  23|                     | |                                | +------------------------------+--------------------------------------------------------------------+   |                                                                                 |
  24|                     | |                                | | Indirect Block Offset        | Where It Points                                                    |   |                                                                                 |
  25|                     | |                                | +==============================+====================================================================+   |                                                                                 |
  26|                     | |                                | | 0 to (``$block_size`` / 4)   | Direct map to (``$block_size`` / 4) blocks (1024 if 4KiB blocks)   |   |                                                                                 |
  27|                     | |                                | +------------------------------+--------------------------------------------------------------------+   |                                                                                 |
  28|                     | +--------------------------------+---------------------------------------------------------------------------------------------------------+                                                                                 |
  29+---------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
  30| 14                  | Triple-indirect block: (file blocks (``$block_size`` / 4) ^ 2 + (``$block_size`` / 4) + 12 to (``$block_size`` / 4) ^ 3 + (``$block_size`` / 4) ^ 2 + (``$block_size`` / 4) + 12, or 1049612 to 1074791436 if 4KiB blocks)   |
  31|                     |                                                                                                                                                                                                                              |
  32|                     | +--------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------+                                          |
  33|                     | | Triple Indirect Block Offset   | Where It Points                                                                                                                                |                                          |
  34|                     | +================================+================================================================================================================================================+                                          |
  35|                     | | 0 to (``$block_size`` / 4)     | Map to (``$block_size`` / 4) double indirect blocks (1024 if 4KiB blocks)                                                                      |                                          |
  36|                     | |                                |                                                                                                                                                |                                          |
  37|                     | |                                | +--------------------------------+---------------------------------------------------------------------------------------------------------+   |                                          |
  38|                     | |                                | | Double Indirect Block Offset   | Where It Points                                                                                         |   |                                          |
  39|                     | |                                | +================================+=========================================================================================================+   |                                          |
  40|                     | |                                | | 0 to (``$block_size`` / 4)     | Map to (``$block_size`` / 4) indirect blocks (1024 if 4KiB blocks)                                      |   |                                          |
  41|                     | |                                | |                                |                                                                                                         |   |                                          |
  42|                     | |                                | |                                | +------------------------------+--------------------------------------------------------------------+   |   |                                          |
  43|                     | |                                | |                                | | Indirect Block Offset        | Where It Points                                                    |   |   |                                          |
  44|                     | |                                | |                                | +==============================+====================================================================+   |   |                                          |
  45|                     | |                                | |                                | | 0 to (``$block_size`` / 4)   | Direct map to (``$block_size`` / 4) blocks (1024 if 4KiB blocks)   |   |   |                                          |
  46|                     | |                                | |                                | +------------------------------+--------------------------------------------------------------------+   |   |                                          |
  47|                     | |                                | +--------------------------------+---------------------------------------------------------------------------------------------------------+   |                                          |
  48|                     | +--------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------+                                          |
  49+---------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
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