This is a basic file system checker written in C language. Its job is to detect errors in a file system image provided to it as a binary. It is not targeted towards any of mainstream in-use filesystems out there (eg ext3/4, FAT etc), but an imaginary filesystem that has many of the important features of real-world file systems. As a result, this checker solves many of the same problems as any other real-world file system checker out there. For details on the types of sanity checks it performs refer to project requirements at Prof. Remzi's (U. Wisconsin) github repository. At this time, it has not been thoroughly tested, as for that I would need carefully generated "bad image" test cases, which I did not have, so this code has been run against a single "good image". Therefore, I can say with some confidence that it does not generate false error detections.
Overall, this is work in progress, and I hope to add more thorough testing in future. Here are the instructions to use it.
- Clone the repository
> git clone https://github.com/kasliwalr/filesystem-checker.git # this will create a filesystem-checker repository folder
- Repository tree
> cd filesytem-checker
> tree -L 1 ./
./
├── docs
│ └── README.md
├── LICENSE
├── Makefile
├── README.md
├── src
│ ├── fileio.c
│ ├── fileio.h
│ ├── fs.h
│ └── xcheck.c
├── test
│ └── fs.img
└── TODO.md
The above shows the organization of the project. src directory contains all the src code (.c, .h files). xcheck.c contains the main() function. fileio.h contains function declartions for helper functions. To easily build the binary, you will need the Makefile
You will find sufficient comment in the src code, to understand what is going on. test directory contains the good file system image fs.img. Note that fs.h contains some useful data structure definitions, this file has been copied from MIT's xv6 code repository
- Installing & running
> cd filesystem-checker
> ls
docs LICENSE Makefile README.md src test TODO.md
> make all # builds the executable named "xcheck"
> ls
docs fileio.o LICENSE Makefile README.md src test TODO.md xcheck xcheck.o
> ./xcheck test/fs.img # run file system checker by passing the fs image to it
done # ran successfully without any errors
This file system checker is targeted towards more traditional file systems such as ext2/ext3 and not the more recent variety of log-structured filesystems. It also does not handle network file systems. This is a work in progress, ultimately, I intend to build a full fledged filesystem checker and recovery tool targted toward one of the mainstream filesystems