Date:   Thu, 4 Apr 2019 06:52:16 -0400 (EDT)
From:   Pankaj Gupta <pagupta@redhat.com>
To:     Adam Borowski <kilobyte@angband.pl>
Cc:     Dave Chinner <david@fromorbit.com>,
        darrick wong <darrick.wong@oracle.com>,
        linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org,
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        linux-fsdevel@vger.kernel.org, linux-acpi@vger.kernel.org,
        qemu-devel@nongnu.org, linux-ext4@vger.kernel.org,
        linux-xfs@vger.kernel.org,
        dan j williams <dan.j.williams@intel.com>,
        zwisler@kernel.org, vishal l verma <vishal.l.verma@intel.com>,
        dave jiang <dave.jiang@intel.com>, mst@redhat.com,
        jasowang@redhat.com, willy@infradead.org, rjw@rjwysocki.net,
        hch@infradead.org, lenb@kernel.org, jack@suse.cz, tytso@mit.edu,
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        stefanha@redhat.com, aarcange@redhat.com, david@redhat.com,
        cohuck@redhat.com,
        xiaoguangrong eric <xiaoguangrong.eric@gmail.com>
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Subject: Re: [PATCH v4 5/5] xfs: disable map_sync for async flush
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> 
> 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?
> ⠈⠳⣄⠀⠀⠀⠀
>