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Date: Thu, 13 Jul 2017 00:15:33 -0700
From: Christoph Hellwig <hch@infradead.org>
To: Jay Lan <jay.j.lan@nasa.gov>
Cc: linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH] export symbol mount_lock
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On Wed, Jul 12, 2017 at 02:40:11PM -0700, Jay Lan wrote:
> Hi all,
> 
> I was writing a livepatch patch, but compilation failed in creating the .ko
> because mount_lock is "undefined."
> 
> The mount_lock is defined globally in fs/namespace.c
> __cacheline_aligned_in_smp DEFINE_SEQLOCK(mount_lock);
> 
> and extern in fs/mount.h.
> extern seqlock_t mount_lock;
> 
> If there is a reason that mount_lock should not be EXPORT_SYMBOL_GPL, please
> advise; otherwise, I propose the patch to export this symbol.

Because there is no %$^$^ reason to use it from a module ever?