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Date:   Fri, 17 Jul 2020 11:22:43 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     ira.weiny@intel.com
Cc:     Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Andy Lutomirski <luto@kernel.org>, x86@kernel.org,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Vishal Verma <vishal.l.verma@intel.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Fenghua Yu <fenghua.yu@intel.com>, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org,
        linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
        linux-kselftest@vger.kernel.org
Subject: Re: [PATCH RFC V2 14/17] dax: Stray write protection for
 dax_direct_access()
Message-ID: <20200717092243.GD10769@hirez.programming.kicks-ass.net>
References: <20200717072056.73134-1-ira.weiny@intel.com>
 <20200717072056.73134-15-ira.weiny@intel.com>
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On Fri, Jul 17, 2020 at 12:20:53AM -0700, ira.weiny@intel.com wrote:

> --- a/drivers/dax/super.c
> +++ b/drivers/dax/super.c
> @@ -30,12 +30,14 @@ static DEFINE_SPINLOCK(dax_host_lock);
>  
>  int dax_read_lock(void)
>  {
> +	dev_access_enable();
>  	return srcu_read_lock(&dax_srcu);
>  }
>  EXPORT_SYMBOL_GPL(dax_read_lock);
>  
>  void dax_read_unlock(int id)
>  {
> +	dev_access_disable();
>  	srcu_read_unlock(&dax_srcu, id);
>  }
>  EXPORT_SYMBOL_GPL(dax_read_unlock);

This is inconsistently ordered.