From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:38628 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727961AbfEKApv (ORCPT ); Fri, 10 May 2019 20:45:51 -0400 Date: Fri, 10 May 2019 20:45:49 -0400 (EDT) From: Pankaj Gupta Message-ID: <864186878.28040999.1557535549792.JavaMail.zimbra@redhat.com> In-Reply-To: References: <20190510155202.14737-1-pagupta@redhat.com> <20190510155202.14737-4-pagupta@redhat.com> Subject: Re: [PATCH v8 3/6] libnvdimm: add dax_dev sync flag MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Dan Williams Cc: linux-nvdimm , Linux Kernel Mailing List , virtualization@lists.linux-foundation.org, KVM list , linux-fsdevel , Linux ACPI , Qemu Developers , linux-ext4 , linux-xfs , Ross Zwisler , Vishal L Verma , Dave Jiang , "Michael S. Tsirkin" , Jason Wang , Matthew Wilcox , "Rafael J. Wysocki" , Christoph Hellwig , Len Brown , Jan Kara , Theodore Ts'o , Andreas Dilger , "Darrick J. Wong" , lcapitulino@redhat.com, Kevin Wolf , Igor Mammedov , jmoyer , Nitesh Narayan Lal , Rik van Riel , Stefan Hajnoczi , Andrea Arcangeli , David Hildenbrand , david , cohuck@redhat.com, Xiao Guangrong , Paolo Bonzini , Adam Borowski , yuval shaia , jstaron@google.com > > > > This patch adds 'DAXDEV_SYNC' flag which is set > > for nd_region doing synchronous flush. This later > > is used to disable MAP_SYNC functionality for > > ext4 & xfs filesystem for devices don't support > > synchronous flush. > > > > Signed-off-by: Pankaj Gupta > > --- > > drivers/dax/bus.c | 2 +- > > drivers/dax/super.c | 13 ++++++++++++- > > drivers/md/dm.c | 3 ++- > > drivers/nvdimm/pmem.c | 5 ++++- > > drivers/nvdimm/region_devs.c | 7 +++++++ > > include/linux/dax.h | 8 ++++++-- > > include/linux/libnvdimm.h | 1 + > > 7 files changed, 33 insertions(+), 6 deletions(-) > [..] > > diff --git a/drivers/md/dm.c b/drivers/md/dm.c > > index 043f0761e4a0..ee007b75d9fd 100644 > > --- a/drivers/md/dm.c > > +++ b/drivers/md/dm.c > > @@ -1969,7 +1969,8 @@ static struct mapped_device *alloc_dev(int minor) > > sprintf(md->disk->disk_name, "dm-%d", minor); > > > > if (IS_ENABLED(CONFIG_DAX_DRIVER)) { > > - dax_dev = alloc_dax(md, md->disk->disk_name, &dm_dax_ops); > > + dax_dev = alloc_dax(md, md->disk->disk_name, &dm_dax_ops, > > + DAXDEV_F_SYNC); > > Apologies for not realizing this until now, but this is broken. > Imaging a device-mapper configuration composed of both 'async' > virtio-pmem and 'sync' pmem. The 'sync' flag needs to be unified > across all members. I would change this argument to '0' and then > arrange for it to be set at dm_table_supports_dax() time after > validating that all components support synchronous dax. o.k. Need to set 'DAXDEV_F_SYNC' flag after verifying all the target components support synchronous DAX. Just a question, If device mapper configuration have composed of both virtio-pmem or pmem devices, we want to configure device mapper for async flush? Thank you, Pankaj >