From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_MUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0379DC282E1 for ; Thu, 23 May 2019 16:19:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CD3FE2175B for ; Thu, 23 May 2019 16:19:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731419AbfEWQTW (ORCPT ); Thu, 23 May 2019 12:19:22 -0400 Received: from tartarus.angband.pl ([54.37.238.230]:38484 "EHLO tartarus.angband.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731117AbfEWQTV (ORCPT ); Thu, 23 May 2019 12:19:21 -0400 Received: from kilobyte by tartarus.angband.pl with local (Exim 4.92) (envelope-from ) id 1hTqQv-0002uo-JE; Thu, 23 May 2019 18:19:09 +0200 Date: Thu, 23 May 2019 18:19:09 +0200 From: Adam Borowski To: Jan Kara Cc: Goldwyn Rodrigues , linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, david@fromorbit.com, willy@infradead.org, hch@lst.de, darrick.wong@oracle.com, dsterba@suse.cz, nborisov@suse.com, linux-nvdimm@lists.01.org, Goldwyn Rodrigues Subject: Re: [PATCH 12/18] btrfs: allow MAP_SYNC mmap Message-ID: <20190523161909.GA10771@angband.pl> References: <20190429172649.8288-1-rgoldwyn@suse.de> <20190429172649.8288-13-rgoldwyn@suse.de> <20190523134449.GC2949@quack2.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20190523134449.GC2949@quack2.suse.cz> X-Junkbait: aaron@angband.pl, zzyx@angband.pl User-Agent: Mutt/1.10.1 (2018-07-13) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: kilobyte@angband.pl X-SA-Exim-Scanned: No (on tartarus.angband.pl); SAEximRunCond expanded to false Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Thu, May 23, 2019 at 03:44:49PM +0200, Jan Kara wrote: > On Mon 29-04-19 12:26:43, Goldwyn Rodrigues wrote: > > From: Adam Borowski > > > > Used by userspace to detect DAX. > > [rgoldwyn@suse.com: Added CONFIG_FS_DAX around mmap_supported_flags] > > Why the CONFIG_FS_DAX bit? Your mmap(2) implementation understands > implications of MAP_SYNC flag and that's all that's needed to set > .mmap_supported_flags. Good point. Also, that check will need to be updated when the pmem-virtio patchset goes in. > > Signed-off-by: Adam Borowski > > Signed-off-by: Goldwyn Rodrigues > > --- > > fs/btrfs/file.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c > > index 9d5a3c99a6b9..362a9cf9dcb2 100644 > > --- a/fs/btrfs/file.c > > +++ b/fs/btrfs/file.c > > @@ -16,6 +16,7 @@ > > #include > > #include > > #include > > +#include > > #include "ctree.h" > > #include "disk-io.h" > > #include "transaction.h" > > @@ -3319,6 +3320,9 @@ const struct file_operations btrfs_file_operations = { > > .splice_read = generic_file_splice_read, > > .write_iter = btrfs_file_write_iter, > > .mmap = btrfs_file_mmap, > > +#ifdef CONFIG_FS_DAX > > + .mmap_supported_flags = MAP_SYNC, > > +#endif > > .open = btrfs_file_open, > > .release = btrfs_release_file, > > .fsync = btrfs_sync_file, > > -- > > 2.16.4 > > > -- > Jan Kara > SUSE Labs, CR > -- ⢀⣴⠾⠻⢶⣦⠀ Latin: meow 4 characters, 4 columns, 4 bytes ⣾⠁⢠⠒⠀⣿⡁ Greek: μεου 4 characters, 4 columns, 8 bytes ⢿⡄⠘⠷⠚⠋ Runes: ᛗᛖᛟᚹ 4 characters, 4 columns, 12 bytes ⠈⠳⣄⠀⠀⠀⠀ Chinese: 喵 1 character, 2 columns, 3 bytes <-- best!