_____ _   _ _____ _____        _____                 _          
|  ___| \_/ |_   _|___  \      |_   _|               | |
| |___ \   /  | |   __) |        | |  _____  ___  ___| |_____ 
|  ___| | |   | |  / ___/        | | |  _  \/ _ \/  _  |  __ \
| |___ / _ \  | | / /___        _| |_| | | | (_) | (_| |  ___/
|_____|_/ \_| |_| |_____|      |_____|_| |_|\___/\_____|_____|

Reference (All these are absolute block numbers):
[P] Direct pointer
[S] Single indirect
[D] Double indirect
[T] Triple indirect

Amount of block pointers (32 bit numbers) per block:
bn_per_block = block_size / sizeof(uint32_t)

fs_file fields:
single_index (0 means there is no single indirect block loaded)
double_index (0 means there is no double indirect block loaded)

There is no triple_index because there is only one

Inode block fields:
[P] block_index = 0
[P] block_index = 1
[P] block_index = 2
[P] block_index = 3
[P] block_index = 4
[P] block_index = 5
[P] block_index = 6
[P] block_index = 7
[P] block_index = 8
[P] block_index = 9
[P] block_index = 10
[P] block_index = 11
[S] single_index = 1 -------> [P] block_index = 12
[D] double_index = 1 ---.     [P] block_index = 13
[T] (Only one) ----.    |     [P] block_index = 14
                   |    |     [P] block_index = 15
   .---------------'    |     ...
   |                    |     [P] block_index = 12 + bn_per_block - 1
   |  .-----------------'   
   |  |   
   |  |                      .- This is why is doubly_indirect[single_index - 2]
   |  |                      |  in ext2_seek
   |  |                      |
   |  |                      v
   |  '-> [S] single_index = 2 --> [P] block_index = (12 + bn_per_block) 
   |      [S] single_index = 3     [P] block_index = (12 + bn_per_block) + 1
   |      [S] single_index = 4     [P] block_index = (12 + bn_per_block) + 2
   |      [S] single_index = 5     ...
   |      [S] single_index = 6     [P] block_index = 12 + (2 * bn_per_block) - 1
   |      ...
   |      [S] single_index = 1 + bn_per_block
   |
   |
   |                      .- This is why is triply_indirect[double_index - 2]
   |                      |  in ext2_seek
   |                      |
   |                      v
   '-> [D] double_index = 2 --> [S] single_index = (1 + bn_per_block) + 1 ----.
       [D] double_index = 3     [S] single_index = (1 + bn_per_block) + 2     |
       [D] double_index = 4     ...                                           |
       [D] double_index = 5     [S] single_index = 1 + (2 * bn_per_block) + 1 |
       ...                                                                    |
       [D] double_index = 1 + bn_per_block                                    |
                                                                              |
   .--------------------------------------------------------------------------'
   |
   '-> [P] block_index = 12 + bn_per_block + bn_per_block * bn_per_block
       [P] block_index = 12 + bn_per_block + bn_per_block * bn_per_block + 1
       [P] block_index = 12 + bn_per_block + bn_per_block * bn_per_block + 2
       ...
       [P] block_index = 12 + 2 * bn_per_block + bn_per_block * bn_per_block - 1