Summary
- Linux 7.0 may add xfs_scrub to repair filesystems live without rebooting.
- The kernel uses “fserror” to notify an xfs_healer daemon, which triggers fixes.
- The feature isn’t guaranteed for 7.0 and won’t fix user-file corruption or hardware failure.
As a long-time Windows user, I always dreaded the CHKDSK screen when I signed back in. I remember back in the late-90s to early-2000s, when it’d start up if you didn’t shut down properly, and it usually took an age to complete. These days, it’s not so intrusive, but you still need to reboot to actually repair your filesystem.
Fortunately, it seems that Linux 7.0 may get a new feature on the XFS filesystem that will automatically perform a similar task while you’re still using your PC, and while it’s not guaranteed to be in 7.0 just yet, it’s in the final stages and just waiting for Linus himself to give it a thumbs-up.
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Linux is a completely different beast than it was a decade ago.
Linux 7.0 may bring a new automatic mechanic, xfs_scrub, into the fray
They’ll keep your filesystem ticking over without needing to reboot it
As spotted by Linuxiac, a new pull request has appeared for Linux 7.0. If accepted, this change will introduce a new way for Linux filesystems to repair errors on the fly, instead of waiting for a reboot.
Right now, when something goes wrong in your Linux filesystem (such as metadata getting corrupted or issues with unmounts), the kernel can identify it, but it can’t do much about it. Instead, you need to run a scan on an unmounted drive to make sure everything is going okay and fix any problems.
This new feature will add a new warning system called “fserror.” Instead of just writing it down and waiting for a reboot, the kernel can use fserror to broadcast the error. This, in turn, notifies a daemon called “xfs_healer,” which makes a decision on whether a fix needs to roll out. If it decides something is wrong, xfs_healer sends out “xfs_scrub” to fix the issue.
The key thing to note here is that xfs_scrub will repair the problems even if the target drive is mounted and in-use. As such, if this tool ends up arriving in 7.0, we shouldn’t need to restart our PCs to check for errors anymore. Of course, xfs_scrub can only do so much; it can’t repair corrupted user files or fix a hard drive crash, for instance. However, it will be able to keep your filesystem in healthy, working order without you needing to lift a finger. It’s something my 2000s self would have appreciated before 20-minute CHKDSK scans were a thing, at least.
Again, it’s worth noting that this feature hasn’t been cemented in Linux 7.0 just yet. It’s still a request, and there’s still a chance that something goes wrong and it gets delayed for a future patch. And if it does get accepted, it’ll only work on XFS drives, and not EXT4 or Btrfs. However, it is a very exciting peek into the future of Linux, where, by the time you’ve noticed a disk error, the OS has already repaired it for you.
