[PATCH] xfs: add ->pfn_mkwrite support for DAX

[Boaz Harrosh]

On 09/02/2015 04:25 AM, Dave Chinner wrote:
> From: Dave Chinner <dchinner at redhat.com>
> 
> ->pfn_mkwrite support is needed so that when a page with allocated
> backing store first takes a write fault the timestamps on the
> file are updated. THis fixes a generic/080 failure.
> 
> Signed-off-by: Dave Chinner <dchinner at redhat.com>

Reviewed-by: Boaz Harrosh <boaz at plexistor.com>

I made a patch for this yesterday, but yours is better of-course
I feel guilty because I sent the patch for the pfn_mkwrite thing,
at the time xfs-dax was not yet in, but I forgot all about it when
reviewing the xfs-dax. My bad, sorry.

Thanks Dave
Boaz

> ---
>  fs/xfs/xfs_file.c  | 11 +++++++++++
>  fs/xfs/xfs_trace.h |  1 +
>  2 files changed, 12 insertions(+)
> 
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index de2c237..26535ba 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -1546,10 +1546,21 @@ xfs_filemap_fault(
>  	return ret;
>  }
>  
> +static int
> +xfs_filemap_pfn_mkwrite(
> +	struct vm_area_struct	*vma,
> +	struct vm_fault		*vmf)
> +{
> +	trace_xfs_filemap_pfn_mkwrite(XFS_I(file_inode(vma->vm_file)));
> +
> +	return dax_pfn_mkwrite(vma, vmf);
> +}
> +
>  static const struct vm_operations_struct xfs_file_vm_ops = {
>  	.fault		= xfs_filemap_fault,
>  	.map_pages	= filemap_map_pages,
>  	.page_mkwrite	= xfs_filemap_page_mkwrite,
> +	.pfn_mkwrite	= xfs_filemap_pfn_mkwrite,
>  };
>  
>  STATIC int
> diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
> index 8b5432e..63d87f2 100644
> --- a/fs/xfs/xfs_trace.h
> +++ b/fs/xfs/xfs_trace.h
> @@ -688,6 +688,7 @@ DEFINE_INODE_EVENT(xfs_inode_free_eofblocks_invalid);
>  
>  DEFINE_INODE_EVENT(xfs_filemap_fault);
>  DEFINE_INODE_EVENT(xfs_filemap_page_mkwrite);
> +DEFINE_INODE_EVENT(xfs_filemap_pfn_mkwrite);
>  
>  DECLARE_EVENT_CLASS(xfs_iref_class,
>  	TP_PROTO(struct xfs_inode *ip, unsigned long caller_ip),
>