Re: [PATCH v2 16/16] xfs: add pre-content fsnotify hook for write faults

[Dave Chinner <david@fromorbit.com>]

On Thu, Aug 08, 2024 at 03:27:18PM -0400, Josef Bacik wrote:
> xfs has it's own handling for write faults, so we need to add the
> pre-content fsnotify hook for this case.  Reads go through filemap_fault
> so they're handled properly there.
> 
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> ---
>  fs/xfs/xfs_file.c | 20 +++++++++++++++++---
>  1 file changed, 17 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index 4cdc54dc9686..585a8c2eea0f 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -1325,14 +1325,28 @@ __xfs_filemap_fault(
>  	bool			write_fault)
>  {
>  	struct inode		*inode = file_inode(vmf->vma->vm_file);
> +	struct file		*fpin = NULL;
> +	vm_fault_t		ret;
>  
>  	trace_xfs_filemap_fault(XFS_I(inode), order, write_fault);
>  
> -	if (write_fault)
> -		return xfs_write_fault(vmf, order);
>  	if (IS_DAX(inode))
>  		return xfs_dax_read_fault(vmf, order);
> -	return filemap_fault(vmf);
> +
> +	if (!write_fault)
> +		return filemap_fault(vmf);

Doesn't this break DAX read faults? i.e. they have to go through
xfs_dax_read_fault(), not filemap_fault().

-Dave.
-- 
Dave Chinner
david@fromorbit.com