For this project you’ll get some real file system programming experience by creating a file system checker.As in past projects, the details are on our textbook authors’ Github, in the ostep-projects repo
Write all your code in one file, xcheck.c. You can compile this
program with gcc, or use a Makefile. Try adapting a Makefile from a
previous project.
We will be using the x86 version of xv6, revision 8. You can find that version of the bok here.
You will also need the xv6 souce code. You should clone it from git, then checkout the revision that we are using. Something like this:
git clone https://github.com/mit-pdos/xv6-public xv6
git checkout tags/xv6-rev8
xv6 is an entire OS, so much of the code will be irrelevant. fs.h
and mkfs.c are most relevant, along with a few others.
fs.h defines the structures and parameters for xv6’s file system.
mkfs.c is the program that actually creates file system. You can
compile it by running gcc -Werror -Wall -std=gnu99 -o mkfs
mkfs.c. Alternative you can use the Makefile by running make mkfs,
but note that you’ll need to first modify the Makefile target by
adding the -std=gnu99 flag.
Once compiled, you can run ./mkfs fs.img to make an xv6 file system
image. This image should not have any errors. It is highly recommended
that you copy mkfs.c (possibly several times) and modify the code to
create corrupted file system images. Then you can check that your
program finds the errors.
Submit using handin on the department server:
$ handin comp345 proj4 xcheck.c
Due Wednesday, 05/03 by midnight.