Re: ext4: 3.17? problems

From: Jan Kara
Date: Wed Oct 01 2014 - 04:48:19 EST


On Tue 30-09-14 23:01:08, Pavel Machek wrote:
> > > On next boot to Debian stable, I got stacktrace, and messages about
> > > ext4 corruption. Back to Debian testing. systemd ran fsck, determined
> > It would be really good to get those messages... Ideally you could also
> > use
> > e2image -r <partition> | bzip2 -c
> > to store fs metadata before doing anything else with the fs to a usb stick.
> > That is invaluable for future analysis.
>
> Too late for that :-(.
OK, you can take a note for next time ;)

> > > it can't fix it, dropped me into emergency shell, _but mounted the
> > > filesstem, anyway_. Oops.
> > What kernel versions are you running in Debian testing and stable?
>
> Debian testing was 3.17-rc4, AFAICT. For debian stable -- not sure.
OK, there were some changes to orphan list locking in 3.17-rc1. If I
screwed up it could cause orphan list corruption. But for now I don't think
that's the issue.

> > My guess would be that kernel had problems only during orphan inode
> > recovery (i.e. when deleting already deleted files) and we let the mount
> > proceed if this fails because it's a relatively harmless problem.
>
> Is there some phase during shutdown where journalling no longer
> protects fs integrity?
No. We first finish all modifications to the fs and only after that clean
up the journal. So that makes all changes to the fs protected.

Honza
--
Jan Kara <jack@xxxxxxx>
SUSE Labs, CR
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