From: Richard Weinberger <richard.weinberger@gmail.com>
To: Lars Persson <lists@bofh.nu>
Cc: linux-mtd@lists.infradead.org
Subject: Re: UBIFS file-system corruption (missing inode) after power-cut on 4.14.96
Date: Thu, 28 Mar 2019 18:31:22 +0100 [thread overview]
Message-ID: <CAFLxGvye+F5hB+1DUUhDzjaHB5ajC_M+W3fyt5x840sO68RgUQ@mail.gmail.com> (raw)
In-Reply-To: <CADnJP=svNQ_LRq1OWbCMNNeTHs_-fAe1kmU1+G4GZ2BV0Jvo2w@mail.gmail.com>
On Thu, Mar 28, 2019 at 12:54 PM Lars Persson <lists@bofh.nu> wrote:
>
> On Tue, Mar 26, 2019 at 10:21 AM Lars Persson <lists@bofh.nu> wrote:
> >
> > On Thu, Mar 21, 2019 at 11:02 AM Lars Persson <lists@bofh.nu> wrote:
> > >
> > > The missing inode is always triggered on those two particular files
> > > emotiond.conf and tampering.conf that share the same write pattern at startup:
> > >
> > > cp file file.tmp
> > > echo some data > file.tmp
> > > mv file.tmp file
> > > fsync file
> > >
> >
> > A closer look at that script shows that the atomic file update part
> > was bypassed. It only performs a chown operation on that file.
> > That simple chown will trigger an overlayfs copyup operation.
> >
> > With a proper unmount after the system has finished writing to /etc I
> > cannot reproduce any corruption. An unclean shutdown triggers
> > corruption in about 1/3 of the attempts, also when I cut power tens of
> > seconds after the problematic script has executed.
>
> OK I think I have found the bug.
Thanks for hunting this down!
> Commit 32fe905c17f0 ("Fix O_TMPFILE corner case in ubifs_link()")
> tried to fix the use of O_TMPFILE by removing an inode from the orphan
> list when it is relinked.
>
> Unfortunately the removal never gets committed to flash because the
> removal of an orphan does not trigger a commit. The condition for
> committing is that new_orphans > 0, but in our case it is zero after
> the call to ubifs_delete_orphan().
Can you please share me your corrupted fs?
I'm not so sure what is really the root cause.
The thing is, ubifs_delete_orphan() does not need to tigger a commit.
Ff something depends on a commit, we have another problem, I fear.
--
Thanks,
//richard
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next prev parent reply other threads:[~2019-03-28 17:31 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-21 10:02 UBIFS file-system corruption (missing inode) after power-cut on 4.14.96 Lars Persson
2019-03-25 10:21 ` Lars Persson
2019-03-26 9:21 ` Lars Persson
2019-03-28 11:54 ` Lars Persson
2019-03-28 17:31 ` Richard Weinberger [this message]
2019-03-29 9:43 ` Lars Persson
2019-04-04 21:31 ` Richard Weinberger
2019-04-04 21:53 ` Richard Weinberger
2019-04-05 13:19 ` Lars Persson
2019-04-05 13:23 ` Richard Weinberger
2019-07-10 7:14 ` Lars Persson
2019-07-10 9:02 ` Richard Weinberger
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