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(a)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.