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blockmap.rst

blockmap.rst 11 KB
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  1. .. SPDX-License-Identifier: GPL-2.0
    2. 

  2. 

  3. +---------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
    4. 

  4. | i.i_block Offset    | Where It Points                                                                                                                                                                                                              |
    5. 

  5. +=====================+==============================================================================================================================================================================================================================+
    6. 

  6. | 0 to 11             | Direct map to file blocks 0 to 11.                                                                                                                                                                                           |
    7. 

  7. +---------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
    8. 

  8. | 12                  | Indirect block: (file blocks 12 to (``$block_size`` / 4) + 11, or 12 to 1035 if 4KiB blocks)                                                                                                                                 |
    9. 

  9. |                     |                                                                                                                                                                                                                              |
    10. 

  10. |                     | +------------------------------+--------------------------------------------------------------------+                                                                                                                        |
    11. 

  11. |                     | | Indirect Block Offset        | Where It Points                                                    |                                                                                                                        |
    12. 

  12. |                     | +==============================+====================================================================+                                                                                                                        |
    13. 

  13. |                     | | 0 to (``$block_size`` / 4)   | Direct map to (``$block_size`` / 4) blocks (1024 if 4KiB blocks)   |                                                                                                                        |
    14. 

  14. |                     | +------------------------------+--------------------------------------------------------------------+                                                                                                                        |
    15. 

  15. +---------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
    16. 

  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. 

  17. |                     |                                                                                                                                                                                                                              |
    18. 

  18. |                     | +--------------------------------+---------------------------------------------------------------------------------------------------------+                                                                                 |
    19. 

  19. |                     | | Double Indirect Block Offset   | Where It Points                                                                                         |                                                                                 |
    20. 

  20. |                     | +================================+=========================================================================================================+                                                                                 |
    21. 

  21. |                     | | 0 to (``$block_size`` / 4)     | Map to (``$block_size`` / 4) indirect blocks (1024 if 4KiB blocks)                                      |                                                                                 |
    22. 

  22. |                     | |                                |                                                                                                         |                                                                                 |
    23. 

  23. |                     | |                                | +------------------------------+--------------------------------------------------------------------+   |                                                                                 |
    24. 

  24. |                     | |                                | | Indirect Block Offset        | Where It Points                                                    |   |                                                                                 |
    25. 

  25. |                     | |                                | +==============================+====================================================================+   |                                                                                 |
    26. 

  26. |                     | |                                | | 0 to (``$block_size`` / 4)   | Direct map to (``$block_size`` / 4) blocks (1024 if 4KiB blocks)   |   |                                                                                 |
    27. 

  27. |                     | |                                | +------------------------------+--------------------------------------------------------------------+   |                                                                                 |
    28. 

  28. |                     | +--------------------------------+---------------------------------------------------------------------------------------------------------+                                                                                 |
    29. 

  29. +---------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
    30. 

  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. 

  31. |                     |                                                                                                                                                                                                                              |
    32. 

  32. |                     | +--------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------+                                          |
    33. 

  33. |                     | | Triple Indirect Block Offset   | Where It Points                                                                                                                                |                                          |
    34. 

  34. |                     | +================================+================================================================================================================================================+                                          |
    35. 

  35. |                     | | 0 to (``$block_size`` / 4)     | Map to (``$block_size`` / 4) double indirect blocks (1024 if 4KiB blocks)                                                                      |                                          |
    36. 

  36. |                     | |                                |                                                                                                                                                |                                          |
    37. 

  37. |                     | |                                | +--------------------------------+---------------------------------------------------------------------------------------------------------+   |                                          |
    38. 

  38. |                     | |                                | | Double Indirect Block Offset   | Where It Points                                                                                         |   |                                          |
    39. 

  39. |                     | |                                | +================================+=========================================================================================================+   |                                          |
    40. 

  40. |                     | |                                | | 0 to (``$block_size`` / 4)     | Map to (``$block_size`` / 4) indirect blocks (1024 if 4KiB blocks)                                      |   |                                          |
    41. 

  41. |                     | |                                | |                                |                                                                                                         |   |                                          |
    42. 

  42. |                     | |                                | |                                | +------------------------------+--------------------------------------------------------------------+   |   |                                          |
    43. 

  43. |                     | |                                | |                                | | Indirect Block Offset        | Where It Points                                                    |   |   |                                          |
    44. 

  44. |                     | |                                | |                                | +==============================+====================================================================+   |   |                                          |
    45. 

  45. |                     | |                                | |                                | | 0 to (``$block_size`` / 4)   | Direct map to (``$block_size`` / 4) blocks (1024 if 4KiB blocks)   |   |   |                                          |
    46. 

  46. |                     | |                                | |                                | +------------------------------+--------------------------------------------------------------------+   |   |                                          |
    47. 

  47. |                     | |                                | +--------------------------------+---------------------------------------------------------------------------------------------------------+   |                                          |
    48. 

  48. |                     | +--------------------------------+------------------------------------------------------------------------------------------------------------------------------------------------+                                          |
    49. 

  49. +---------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
    50.