From: Dave Chinner <david@fromorbit.com>
To: Eric Sandeen <sandeen@redhat.com>
Cc: xfs-oss <xfs@oss.sgi.com>
Subject: Re: [PATCH] xfs: disallow rw remount on fs with unknown ro-compat features
Date: Wed, 30 Mar 2016 11:16:08 +1100 [thread overview]
Message-ID: <20160330001608.GG30721@dastard> (raw)
In-Reply-To: <56FAD75C.80502@redhat.com>
On Tue, Mar 29, 2016 at 02:28:28PM -0500, Eric Sandeen wrote:
> Today, a kernel which refuses to mount a filesystem read-write
> due to unknown ro-compat features can still transition to read-write
> via the remount path. The old kernel is most likely none the wiser,
> because it's unaware of the new feature, and isn't using it. However,
> writing to the filesystem may well corrupt metadata related to that
> new feature, and moving to a newer kernel which understand the feature
> will have problems.
>
> Right now the only ro-compat feature we have is the free inode btree,
> which showed up in v3.16. It would be good to push this back to
> all the active stable kernels, I think, so that if anyone is using
> newer mkfs (which enables the finobt feature) with older kernel
> releases, they'll be protected.
Ok, so the bug was introduced with the original extended feature
masks in commit e721f50 ("xfs: implement extended feature masks"),
which was introduced in 3.10. So it will need to go back to stable
kernels all the way back to 3.10, right?
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs
next prev parent reply other threads:[~2016-03-30 0:22 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-29 19:28 [PATCH] xfs: disallow rw remount on fs with unknown ro-compat features Eric Sandeen
2016-03-29 20:40 ` Bill O'Donnell
2016-03-30 0:16 ` Dave Chinner [this message]
2016-03-30 0:27 ` Eric Sandeen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20160330001608.GG30721@dastard \
--to=david@fromorbit.com \
--cc=sandeen@redhat.com \
--cc=xfs@oss.sgi.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox