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Fri, 17 Jul 2020 09:22:44 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 759913003D8; Fri, 17 Jul 2020 11:22:43 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 6588829CF6F4C; Fri, 17 Jul 2020 11:22:43 +0200 (CEST) Date: Fri, 17 Jul 2020 11:22:43 +0200 From: Peter Zijlstra To: ira.weiny@intel.com Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Andy Lutomirski , x86@kernel.org, Dave Hansen , Dan Williams , Vishal Verma , Andrew Morton , Fenghua Yu , 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200717072056.73134-15-ira.weiny@intel.com> X-Rspamd-Queue-Id: 7D65F2D4C5 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam01 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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.