| stpdfs.inc | |
| Stupid Filesystem | |
| Constants and Enumerations | |
| STPDFS_SB_MAGIC | Superblock magic number, MUST BE `0x44505453` (STPD) |
| STPDFS_SB_REV | StupidFS revision, currently `0x1` |
| STPDFS_BSIZE | StupidFS block size (512) |
| STPDFS_BADINO | StupidFS bad inode |
| STPDFS_ROOTINO | StupidFS root inode number |
| STPDFS_NDIRECT | Number of direct block (7) |
| STPDFS_INDIRECT_PER_BLOCK | |
| STPDFS_NAME_MAX | Max file name length (28) |
| StupidFS State | |
| StupidFS i-node flags | |
| STPDFS_INODE_PER_BLOCK | I-node per block |
| STPDFS_DIRENT_PER_BLOCK | Directory entry per block |
| Structs | |
| StpdFS_FreeList | |
| StpdFS_Sb | |
| StpdFS_Inode | StupidFS on disk i-node |
| StpdFS_Dirent | StupidFS directory entry |
| Implementation |
┌──────────┬───────────┬──────┬───┬──────┬────┬───┬────┐ │Boot block│Super block│Inodes│...│Inodes│Data│...│Data│ └──────────┴───────────┴──────┴───┴──────┴────┴───┴────┘
| Constants and Enumerations | |
| STPDFS_SB_MAGIC | Superblock magic number, MUST BE `0x44505453` (STPD) |
| STPDFS_SB_REV | StupidFS revision, currently `0x1` |
| STPDFS_BSIZE | StupidFS block size (512) |
| STPDFS_BADINO | StupidFS bad inode |
| STPDFS_ROOTINO | StupidFS root inode number |
| STPDFS_NDIRECT | Number of direct block (7) |
| STPDFS_INDIRECT_PER_BLOCK | |
| STPDFS_NAME_MAX | Max file name length (28) |
| StupidFS State | |
| StupidFS i-node flags | |
| STPDFS_INODE_PER_BLOCK | I-node per block |
| STPDFS_DIRENT_PER_BLOCK | Directory entry per block |
| Structs | |
| StpdFS_FreeList | |
| StpdFS_Sb | |
| StpdFS_Inode | StupidFS on disk i-node |
| StpdFS_Dirent | StupidFS directory entry |
| STPDFS_INO_FLAG_ALOC | I-node is allocated |
| STPDFS_INO_FLAG_LZP | I-node data is compressed using LZP algorithm (see lzp.asm) |
| STPDFS_INO_FLAG_ENC | I-node data is encrypted with XChaCha12 (see xchacha.asm) |
| .free | List of free block (0-99), index 0 point to next freelist |
| .nfree | Index |
┌──────────┐
│ block 99 │
├──────────┤
│ block 98 │
├──────────┤
│ ... │
├──────────┤
│ block 2 │
├──────────┤
│ block 1 │
├──────────┤ ┌──────────┐
│ block 0 ├───►│ block 99 │
└──────────┘ ├──────────┤
│ ... │
├──────────┤ ┌──────────┐
│ block 0 ├───►│ block 99 │
└──────────┘ ├──────────┤
│ ... │
├──────────┤
│ block 0 │
└──────────┘| .magic | See STPDFS_SB_MAGIC |
| .isize | Size in block of the i-node list |
| .fsize | Size in block of the entire volume |
| .freelist | See StpdFS_FreeList |
| .rev | See STPDFS_SB_REV |
| .state | See StupidFS State |
| .time | Last mod time (64bit UNIX timestamp) |
StupidFS on disk i-node
| .mode | File mode |
| .nlink | Links count |
| .uid | Owner Uid |
| .gid | Group Id |
| .flags | File flags, see StupidFS i-node flags |
| .size | Data size in byte |
| .zone | See bellow |
| .actime | Access time (64-bit UNIX timestamp) |
| .modtime | Modification time (64-bit UNIX timestamp) |
Zone 0-6 are direct, zone 7 indirect, zone 8 double indirect, zone 9 triple indirect
┌────────┐
│ │
┌───────►│Data │
│ │ │
┌──────┐ Direct│ └────────┘
│zone 0├───────┘
├──────┤
│... │
├──────┤ ┌────────┐ ┌────────┐
│zone 6│ │ ├─────►│ │
├──────┤ Indirect │ │ │ Data │
│zone 7├─────────►│ │ │ │
├──────┤ └────────┘ └────────┘
│zone 8├───────┐
├──────┤ │Double indirect┌────────┐ ┌────────┐ ┌────────┐
│zone 9│ └──────────────►│ ├───►│ ├───►│ │
└──┬───┘ │ │ │ │ │ Data │
│ │ │ │ │ │ │
│ └────────┘ └────────┘ └────────┘
│ Triple indirect ┌────────┐
└────────────────►│ │ ┌────────┐ ┌────────┐ ┌────────┐
│ ├───►│ │ │ │ │ │
│ │ │ ├─────►│ ├─────►│ Data │
└────────┘ │ │ │ │ │ │
└────────┘ └────────┘ └────────┘StupidFS directory entry
| .inode | address of i-node |
| .name | null terminated file name (see STPDFS_NAME_MAX) |