Re: [PATCH 1/4] vfs: add file_dentry()

[Al Viro]

On Mon, Mar 21, 2016 at 01:02:15AM -0400, Theodore Ts'o wrote:

> I have this patch in the ext4.git tree, but I'd like to get an
> Acked-by from Al before I send a pull request to Linus.
> 
> Al?  Any objections to my sending in this change via the ext4 tree?
> 						- Ted

FWIW, I would rather add DCACHE_OP_REAL (set at d_set_d_op()
time) and turned that into

static inline struct dentry *d_real(const struct dentry *dentry)
{
	if (unlikely(dentry->d_flags & DCACHE_OP_NATIVE_DENTRY))
		returd dentry->d_op->d_real(dentry);
	else
		return dentry;
}
static inline struct dentry *file_dentry(const struct file *file)
{
	return d_real(file->f_path.dentry);
}

and used ovl_dentry_real as ->d_real for overlayfs.  Miklos, do you
see any problems with that variant?