Re: [Bug 211605] New: Re-mount XFS causes "noattr2 mount option is deprecated" warning

[Dave Chinner <david@fromorbit.com>]

On Sun, Feb 07, 2021 at 04:53:34PM -0600, Eric Sandeen wrote:
> On 2/7/21 4:15 PM, Dave Chinner wrote:
> > On Sun, Feb 07, 2021 at 05:06:36AM +0000, bugzilla-daemon@bugzilla.kernel.org wrote:
> >> https://bugzilla.kernel.org/show_bug.cgi?id=211605
> >>
> >>             Bug ID: 211605
> >>            Summary: Re-mount XFS causes "noattr2 mount option is
> >>                     deprecated" warning
> >>            Product: File System
> >>            Version: 2.5
> >>     Kernel Version: 5.10.13
> >>           Hardware: All
> >>                 OS: Linux
> >>               Tree: Mainline
> >>             Status: NEW
> >>           Severity: low
> >>           Priority: P1
> >>          Component: XFS
> >>           Assignee: filesystem_xfs@kernel-bugs.kernel.org
> >>           Reporter: cuihao.leo@gmail.com
> >>         Regression: No
> >>
> ...
> 
> > The kernel is warning about a mount option being specified that
> > isn't even in the set emitted in /proc/mounts. Nor is it on your
> > command line. Yet the kernel is warning about it, and that implies
> > that mount has passed it to the kernel incorrectly.
> 
> I am confused about how "noattr2" showed up.
> 
> But we do still emit "attr2" in /proc/mounts, and a remount will complain
> about /that/, so we do need to stop emitting deprecated options in /proc/mounts.

No, it does not warn on my systems about attr2, either. Like I said,
there are no warnings on remount at all because mount it not passing
the /proc/mounts information back into the kernel:

# strace -emount -v mount -o remount,ro /mnt/scratch
mount("/dev/vdc", "/mnt/scratch", 0x561f3b93c690, MS_RDONLY|MS_REMOUNT, NULL) = 0
#

This really looks like a mount version/distro issue, not a kernel
issue...

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com