tip/warning/request: Getting fsck.f2fs to run on root-fs

[hceline]

Was not quite sure where to put this, pleas mods move it as see fit.

At the moment fsck.f2fs will not ever run on the root mount if it is formatted f2fs. I discovered this when I got write errors after several power-failures/hangs that cumulatively error-ed out my root-fs to the point where when I finally got a initramfs with fsck.f2fs made; it was too late.
The issue is that a f2fs formatted root fails if you mount it read only, and you can not fsck a mounted f2fs filesystem. And since genkernel does not include fsck.f2fs, it does not get run in initramfs by default either.

That was the tip/warning, here comes the request;
I have reported this here: https://bugs.gentoo.org/666657 but it is still UNCONFIRMED, if you are running f2fs root, please verify my findings and report.

Thanks.

[Perfect Gentleman]

cannot confirm

[hceline]

Thank you, something must have changed since last I tried to boot with root mounted read-only (a very long time ago). I'll have to do some new tests, this is promising.

Edit: Did a test, and there is still one issue as far as I can understand, this line:

[hceline]

Did some more tests, and now I know why I could not boot with root ro before:
I have to remove rw from ROOTFLAGS on kernel command-line, NOT replace it with ro.
If I put ro in ROOTFLAGS i get kernel panic that says "shed: Unexpected reschedule of offline CPU". There are also more errors before that one but they scrolled off screen; I'll have to try hooking up a serial port to get the whole log...

Edit: Got serial hooked up, and the first error was:

[hceline]

Edit: Correction, the part about failing to open RO mounted partition proved to be user error in the end. The patch is not needed anyway. But the part about not fixing a RO mounted partition seems to be a correct assessment.

After a delay due to hardware issues, I finally got this reported to the f2fs-ml. I got a patch for the failed-to-open-RO-partition (attached to my https://bugs.gentoo.org/666657). And I got confirmation that fsck.f2fs does not fix an RO mounted partition, it only check it: https://sourceforge.net/p/linux-f2fs/mailman/message/36645996/

[NeddySeagoon]

hceline,

Being unable to fix a volume mounted read only is expected behaviour.

Looking at the filesystem metadata when files may be open is safe.
Changing it because its not self consistent can break the open files, so its not safe.

All fscks, guess what should be there and make the filesystem metadata self consistent. They do nothing for user data.
When they guess wrong, things go from bad to worse. That's what backups are for.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[hceline]