[RFC PATCH 4/4] xfs: allow linkat() on O_TMPFILE files

[Christoph Hellwig]

> -	ASSERT(ip->i_d.di_nlink > 0);
> +	if ((VFS_I(ip)->i_nlink == 0) &&
> +	    !(VFS_I(ip)->i_state & I_LINKABLE))
> +		ASSERT(ip->i_d.di_nlink > 0);

	ASSERT(ip->i_d.di_nlink > 0 || (VFS_I(ip)->i_state & I_LINKABLE));

> @@ -1498,7 +1503,14 @@ xfs_link(
>  	tp = xfs_trans_alloc(mp, XFS_TRANS_LINK);
>  	cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
>  	resblks = XFS_LINK_SPACE_RES(mp, target_name->len);
> -	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_link, resblks, 0);
> +
> +	if ((VFS_I(sip)->i_nlink == 0) &&
> +	    (VFS_I(sip)->i_state & I_LINKABLE))
> +		tres = &M_RES(mp)->tr_link_tmpfile;
> +	else
> +		tres = &M_RES(mp)->tr_link;

Just check i_nlink, and for consistency it might make sense to just use
the xfs_inode one.  The VFS already made sure we don't inodes with
I_LINKABLE and a zero link count.

> +	if ((VFS_I(sip)->i_nlink == 0) &&
> +	    (VFS_I(sip)->i_state & I_LINKABLE)) {

Same here.