From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:54900 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933224AbdJXN1Q (ORCPT ); Tue, 24 Oct 2017 09:27:16 -0400 Date: Tue, 24 Oct 2017 15:27:13 +0200 From: Jan Kara Subject: Re: [PATCH] mmap.2: Add description of MAP_SHARED_VALIDATE and MAP_SYNC Message-ID: <20171024132713.GD8556@quack2.suse.cz> References: <20171019125817.11580-1-jack@suse.cz> <20171019125817.11580-19-jack@suse.cz> <20171020214753.GA15733@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171020214753.GA15733@linux.intel.com> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Ross Zwisler Cc: Jan Kara , linux-fsdevel@vger.kernel.org, linux-nvdimm@lists.01.org, Dan Williams , linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, Christoph Hellwig , linux-api@vger.kernel.org On Fri 20-10-17 15:47:53, Ross Zwisler wrote: > On Thu, Oct 19, 2017 at 02:58:17PM +0200, Jan Kara wrote: > > Signed-off-by: Jan Kara > > --- > > man2/mmap.2 | 30 ++++++++++++++++++++++++++++++ > > 1 file changed, 30 insertions(+) > > > > diff --git a/man2/mmap.2 b/man2/mmap.2 > > index 47c3148653be..598ff0c64f7f 100644 > > --- a/man2/mmap.2 > > +++ b/man2/mmap.2 > > @@ -125,6 +125,21 @@ are carried through to the underlying file. > > to the underlying file requires the use of > > .BR msync (2).) > > .TP > > +.B MAP_SHARED_VALIDATE > > +The same as > > +.B MAP_SHARED > > +except that > > +.B MAP_SHARED > > +mappings ignore unknown flags in > > +.IR flags . > > +In contrast when creating mapping of > > +.B MAP_SHARED_VALIDATE > > +mapping type, the kernel verifies all passed flags are known and fails the > > +mapping with > > +.BR EOPNOTSUPP > > +otherwise. This mapping type is also required to be able to use some mapping > > +flags. > > +.TP > > Some small nits: > > I think you should maybe include a "(since Linux 4.15)" type note after the > MAP_SHARED_VALIDATE header. You also need to update the following line: > > Both of these flags are described in POSIX.1-2001 and POSIX.1-2008. > > Which used to refer to MAP_SYNC and MAP_PRIVATE. Thanks, I've fixed these. Honza -- Jan Kara SUSE Labs, CR