FUSED

Userspace driver for developing filesystems

Roadmap

• Basic FUSE driver
• Read functions
• Write functions
• IOCTL functions
• Startup functions
• Status functions
• ext2 demo
• Lazy loading
• Buffer cache emulation
• SSD Wear emulation

What is FUSED?

FUSED enables you to map any raw image and expose a device driver interface through 4 functions:

• read_disk
• write_disk
• ioctl_disk
• get_disk_status
• init_disk

How to test FUSED?

First create the build directory structure with make setup You can start by creating a test scenario by simply running make testsetup Then you may build the test program by runnin make fuse and running it by make run Or simply do the last two steps with make

How to use FUSED in your own project?

For this you will have to:

1. Set the config variables in config.h to your liking (comment them to disable) Note: LAZY MODE (EAGER COMMENTED) is unfinished

2. (Optional) modify the stubs in dependencies.h and dependencies.c to suit your environment (they start by __fuse_)

3. Start implementing your fs by including primitives.h

4. In the code used to test your fs implementation include bfuse.h and register the device to the driver by running:

   register_drive("./path/to/image.img", "mount point string", 512); // 512 is the sector size

5. After that, you are golden, now you can run call the driver in your fs, remember to identify the device throgh the mount string

Make targets

Setup and testing targets

• make setup - Creates the build directory structure
• make testsetup - Creates a test scenario with two files (empty and ext2 formatted)
• make demo - Creates a demo file that can be used to test the driver
• make reset - Resets the test scenario images
• make test - Runs the full test scenario
• make cleantest - Undo testsetup
• make cleansetup - Undo setup

Dev targets

• make pull - Refreshes the repository
• make upload - Uploads the repository to the remote

Build targets

• make - Cleans, builds and runs the test program
• make all - Same as above
• make fuse - Builds the program
• make clean - Deletes all compiled files

Run targets

• make run - Runs the program
• make debug - Launches GDB