https://github.com/tomlobato/hash_fs
Flat, hash based, Filesystem
https://github.com/tomlobato/hash_fs
c filesystem kernel-module linux
Last synced: about 1 month ago
JSON representation
Flat, hash based, Filesystem
- Host: GitHub
- URL: https://github.com/tomlobato/hash_fs
- Owner: tomlobato
- License: mit
- Created: 2018-01-29T02:53:00.000Z (over 8 years ago)
- Default Branch: master
- Last Pushed: 2018-03-18T15:51:19.000Z (about 8 years ago)
- Last Synced: 2025-02-14T17:57:27.446Z (over 1 year ago)
- Topics: c, filesystem, kernel-module, linux
- Language: C
- Homepage:
- Size: 226 KB
- Stars: 1
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
HashFs is a [flat filesystem](https://en.wikipedia.org/wiki/File_system#Flat_file_systems) written for learning purposes
with a specific workload in mind:
- Stores milions of files,
- High creat, low unlink rates,
- Fast file lookup.
#### It Uses... ####
- The ridiculously fast XXHash, borrowed from dev kernel to the currently stable 4.15.10 (https://lwn.net/Articles/726337/).
- A list of block Extents for file data, mapped in a array [(start, length), ...] stored at the end of the last data block.
#### Disk Layout
blk 0 / byte 1024
superblock -- hash keys bitmap -- hash keys -- inodes -- data
[metadata size calulations](https://docs.google.com/spreadsheets/d/1HkgOJFZwWhxS5sdxalrPe4urQfaviGriIXZLOjGbrfY/edit#gid=0)
#### Refs
- https://github.com/torvalds/linux/tree/master/fs/ext2
- https://github.com/torvalds/linux/blob/master/Documentation/kernel-hacking/hacking.rst
- https://github.com/torvalds/linux/blob/master/Documentation/kernel-hacking/hacking.rst#recipes-for-deadlock
- https://github.com/torvalds/linux/blob/master/Documentation/kernel-hacking/hacking.rst#common-routines
- https://stackoverflow.com/questions/16390004/change-default-console-loglevel-during-boot-up