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From: Attilio Rao <attilio@freebsd.org>
To: Konstantin Belousov <kib@freebsd.org>
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Subject: Re: svn commit: r204470 - head/sys/fs/msdosfs
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2010/2/28 Konstantin Belousov <kib@freebsd.org>:
> Author: kib
> Date: Sun Feb 28 17:13:07 2010
> New Revision: 204470
> URL: http://svn.freebsd.org/changeset/base/204470
>
> Log:
> =C2=A0Add per-mountpoint lockmgr lock for msdosfs. It is intended to be u=
sed
> =C2=A0as fat bitmap lock and to replace global mutex protecting fileno rb=
tree.

Looking at this patch, it seems you can safely use a sx lock here and
I would prefer that as we don't want to encourage more lockmgr to get
in.
If you are concerned about writer starvation in any way here,
probabilly the right solution is to implement it in sx and remove
lockmgr also from the export code.

Attilio


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