Re: [PATCH v4 5/5] xfs: disable map_sync for async flush

From: Pankaj Gupta <pagupta@redhat.com>
To: Adam Borowski <kilobyte@angband.pl>
Cc: cohuck@redhat.com, jack@suse.cz, kvm@vger.kernel.org,
	mst@redhat.com, Dave Chinner <david@fromorbit.com>,
	qemu-devel@nongnu.org, virtualization@lists.linux-foundation.org,
	adilger kernel <adilger.kernel@dilger.ca>,
	zwisler@kernel.org, aarcange@redhat.com,
	dave jiang <dave.jiang@intel.com>,
	linux-nvdimm@lists.01.org,
	vishal l verma <vishal.l.verma@intel.com>,
	willy@infradead.org, hch@infradead.org,
	linux-acpi@vger.kernel.org, jmoyer@redhat.com,
	linux-ext4@vger.kernel.org, lenb@kernel.org, riel@surriel.com,
	stefanha@redhat.com, dan j williams <dan.j.williams@intel.com>,
	lcapitulino@redhat.com, nilal@redhat.com, tytso@mit.edu,
	xiaoguangrong eric <xiaoguangrong.eric@gmail.com>,
	darrick wong <darrick.wong@oracle.com>,
	rjw@rjwysocki.net, linux-kernel@vger.kernel.org,
	linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	imammedo@redhat.com
Subject: Re: [PATCH v4 5/5] xfs: disable map_sync for async flush
Date: Thu, 4 Apr 2019 06:52:16 -0400 (EDT)	[thread overview]
Message-ID: <511760533.17430856.1554375136102.JavaMail.zimbra__48980.6520681427$1554375153$gmane$org@redhat.com> (raw)
In-Reply-To: <20190404095649.GB8738@angband.pl>

> 
> On Thu, Apr 04, 2019 at 02:12:30AM -0400, Pankaj Gupta wrote:
> > > All this ad hoc IS_DAX conditional logic is getting pretty nasty.
> > > 
> > > xfs_file_mmap(
> > > ....
> > > {
> > > 	struct inode	*inode = file_inode(filp);
> > > 
> > > 	if (vma->vm_flags & VM_SYNC) {
> > > 		if (!IS_DAX(inode))
> > > 			return -EOPNOTSUPP;
> > > 		if (!dax_synchronous(xfs_find_daxdev_for_inode(inode))
> > > 			return -EOPNOTSUPP;
> > > 	}
> > > 
> > > 	file_accessed(filp);
> > > 	vma->vm_ops = &xfs_file_vm_ops;
> > > 	if (IS_DAX(inode))
> > > 		vma->vm_flags |= VM_HUGEPAGE;
> > > 	return 0;
> > > }
> > 
> > Sure, this is better.
> 
> > > Even better, factor out all the "MAP_SYNC supported" checks into a
> > > helper so that the filesystem code just doesn't have to care about
> > > the details of checking for DAX+MAP_SYNC support....
> > 
> > o.k. Will add one common helper function for both ext4 & xfs filesystems.
> 
> Note this pending patch for Goldwyn Rodrigues' patchset for btrfs:
> 
> https://lore.kernel.org/linux-btrfs/20190328102418.5466-1-kilobyte@angband.pl/
> 
> We might want to coordinate.

Sure. Good to know.

Thanks for the pointer. Will have a look.

Best regards,
Pankaj 

> 
> 
> Meow!
> --
> ⢀⣴⠾⠻⢶⣦⠀
> ⣾⠁⢠⠒⠀⣿⡁ Did ya know that typing "test -j8" instead of "ctest -j8"
> ⢿⡄⠘⠷⠚⠋⠀ will make your testsuite pass much faster, and fix bugs?
> ⠈⠳⣄⠀⠀⠀⠀
> 
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