Re: [PATCH v6 6/6] xfs: disable map_sync for async flush

Pankaj Gupta
2019-04-24T04:55:46Z

>
> On Tue, Apr 23, 2019 at 01:36:12PM +0530, Pankaj Gupta wrote:
> > Dont support 'MAP_SYNC' with non-DAX files and DAX files
> > with asynchronous dax_device. Virtio pmem provides
> > asynchronous host page cache flush mechanism. We don't
> > support 'MAP_SYNC' with virtio pmem and xfs.
> >
> > Signed-off-by: Pankaj Gupta <pagupta@redhat.com>
> > ---
> > fs/xfs/xfs_file.c | 10 ++++++----
> > 1 file changed, 6 insertions(+), 4 deletions(-)
> >
> > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> > index 1f2e2845eb76..0e59be018511 100644
> > --- a/fs/xfs/xfs_file.c
> > +++ b/fs/xfs/xfs_file.c
> > @@ -1196,11 +1196,13 @@ xfs_file_mmap(
> > struct file *filp,
> > struct vm_area_struct *vma)
> > {
> > - /*
> > - * We don't support synchronous mappings for non-DAX files. At least
> > - * until someone comes with a sensible use case.
> > + struct dax_device *dax_dev = xfs_find_daxdev_for_inode
> > + (file_inode(filp));
> > +
> > + /* We don't support synchronous mappings for non-DAX files and
> > + * for DAX files if underneath dax_device is not synchronous.
> > */
>
> /*
> * This is the correct multi-line comment format. Please
> * update the patch to maintain the existing comment format.
> */

Sure. Will correct this for both xfs & ext4.

Thanks,
Pankaj

>
> Cheers,
>
> Dave.
> --
> Dave Chinner
> david@fromorbit.com
>