Re: VFS_MOUNT reverses sense of IMNT_MPSAFE test?

Rhialto <[email protected]> Fri, 8 May 2026 12:06:06 +0200

Newsgroups	gmane.os.netbsd.devel.kernel
Message-ID	<[email protected]>

On Thu 07 May 2026 at 07:41:54 -0700, Konrad Schroder wrote:
> While hunting down a deadlock involving mount_null, I ran into a reversed
> test for IMNT_MPSAFE in VFS_MOUNT().  I'm not sure if this is what's causing
> my problem, but it's almost certainly wrong.  Is there something I'm
> missing, or should I commit?

The pattern you spotted indeed looks wrong compared to the other cases
in the same file.

I also had some deadlock when playing with bob some time ago. It does a
lot of null mounts, and if they should have locking but do not (because
of this bug) then this could definitely explain it. (But I don't know if
null mounts are supposed to be MPSAFE or not, so it could still be a
red herring).

-Olaf.
-- 
___ Olaf 'Rhialto' Seibert                            <rhialto/at/falu.nl>
\X/ There is no AI. There is just someone else's work.           --I. Rose

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