xfsr: A C repository from sandyskies

xfsr is a set of crude, alpha-quality tools to read files from a damaged XFS partition for GNU/Linux.

What do you need to rescue a file?

First of all, somewhat healthy superblock fields: sb_blocksize sb_agblocks, sb_inodesize, sb_inopblock, sb_blocklog, sb_inodelog, sb_inopblog, sb_agblklog. If you haven't run mkfs with any special options, re-running mkfs would restore these values back, BUT be aware that this will format your drive. xfs_repair might also help you to restore them. You need

A healty inode
A healty data block.

They usually hold the contents of files, so even if they're corrupted, you'll still be able to dump your file, but the contents would be corrupted. If it's a data block of a directory, then bad news, contents of the directory will be corrupted. If the superblock is corrupted and you want your disk remain intact, you can pass these options from commandline.

How do you rescue a file with these bag of tools?

There's no simple way to locate a file on a partition without a root inode, so one good idea is to try to climb back at top dir. To do this, one can search for directories with xfsr-dirfind (or xfsr-rawsearch along with xfsr-ls, if you can remember the name of the directory you're looking for), list their contents with xfsr-ls, and keep climbing to upper directory. You'll eventually bump into a dead end since inode of the root directory doesn't exist. This is the furthest you can go with these tools; run xfsr-ls with the inode number/address of the last "healthy" dir.

Is it safe to use these tools?

These tools can be considered safe, in the sense that the partiton is opened read-only, so you don't need to work on a copy of it --as long as you don't explicitly output the files to your damaged partiton!

The license is GNU GPL v3+, which means there's no guarantee whatsoever. Don't ever come crying to me if you screw things up.

Will they work for me?

I hope so. I only tested it on my GNU/Linux machine, and they did their job well. I haven't heard of any tests under different archs/unices yet.

Known bugs?

First of, the whole program might be a bug itself. It is dirty, obfuscated to an extent ---the whole thing was writting in a bad mood: the mood of immense data loss. And whole thing was not written with release in mind. I'm publishing the code, because there are no alternatives yet and there might be people who desperately need such a tool out there. It's not even alpha quality, but it's better than nothing. I saved more than 99% of my 750GB data with this tool, but again, there might be serious bugs, and the program can fail.

Having said that, I don't know of any bugs, but there are certain things that were left out, because I though they were of little importance in an average FS: B+ directories and symlinks with extents are not handled yet.

Final notes