Re: [PATCH 1/3] xfs: set ip->i_diflags directly in xfs_inode_inherit_flags

[Dave Chinner <david@fromorbit.com>]

On Mon, May 31, 2021 at 03:40:38PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@kernel.org>
> 
> Remove the unnecessary convenience variable.
> 
> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> ---
>  fs/xfs/xfs_inode.c |   25 +++++++++++--------------
>  1 file changed, 11 insertions(+), 14 deletions(-)
> 
> 
> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> index e4c2da4566f1..1e28997c6f78 100644
> --- a/fs/xfs/xfs_inode.c
> +++ b/fs/xfs/xfs_inode.c
> @@ -689,47 +689,44 @@ xfs_inode_inherit_flags(
>  	struct xfs_inode	*ip,
>  	const struct xfs_inode	*pip)
>  {
> -	unsigned int		di_flags = 0;
>  	xfs_failaddr_t		failaddr;
>  	umode_t			mode = VFS_I(ip)->i_mode;
>  
>  	if (S_ISDIR(mode)) {
>  		if (pip->i_diflags & XFS_DIFLAG_RTINHERIT)
> -			di_flags |= XFS_DIFLAG_RTINHERIT;
> +			ip->i_diflags |= XFS_DIFLAG_RTINHERIT;
>  		if (pip->i_diflags & XFS_DIFLAG_EXTSZINHERIT) {
> -			di_flags |= XFS_DIFLAG_EXTSZINHERIT;
> +			ip->i_diflags |= XFS_DIFLAG_EXTSZINHERIT;
>  			ip->i_extsize = pip->i_extsize;
>  		}

Hmmmm.

IIRC, these functions were originally written this way because the
compiler generated much better code using a local variable than when
writing directly to the ip->i_d.di_flags. Is this still true now?
I think it's worth checking, because we have changed the structure
of the xfs_inode (removed the i_d structure) so maybe this isn't a
concern anymore?

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com