Re: [PATCH 5/6] xfs: merge xfs_reclaim_inodes_ag into xfs_inode_walk_ag

[Christoph Hellwig <hch@infradead.org>]

On Thu, Mar 25, 2021 at 05:21:40PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@kernel.org>
> 
> Merge these two inode walk loops together, since they're pretty similar
> now.  Get rid of XFS_ICI_NO_TAG since nobody uses it.

The laster user of XFS_ICI_NO_TAG was quotoff, and the last reference
was removed in "xfs: remove indirect calls from xfs_inode_walk{,_ag}".
So I think it should be dropped there, or even better in a prep patch
removing all the XFS_ICI_NO_TAG code before that one.

> +static inline bool
> +selected_for_walk(
> +	unsigned int		tag,
> +	struct xfs_inode	*ip)
> +{
> +	switch (tag) {
> +	case XFS_ICI_BLOCKGC_TAG:
> +		return xfs_blockgc_grab(ip);
> +	case XFS_ICI_RECLAIM_TAG:
> +		return xfs_reclaim_inode_grab(ip);
> +	default:
> +		return false;
> +	}
> +}

Maybe name ths something that starts with xfs_ and ends with _grab?

>   * and release all incore inodes with the given radix tree @tag.
> @@ -786,12 +803,14 @@ xfs_inode_walk_ag(
>  	bool			done;
>  	int			nr_found;
>  
> -	ASSERT(tag == XFS_ICI_BLOCKGC_TAG);
> +	ASSERT(tag < RADIX_TREE_MAX_TAGS);
>  
>  restart:
>  	done = false;
>  	skipped = 0;
>  	first_index = 0;
> +	if (tag == XFS_ICI_RECLAIM_TAG)
> +		first_index = READ_ONCE(pag->pag_ici_reclaim_cursor);

if / else to make this clear?

>  		for (i = 0; i < nr_found; i++) {
>  			if (!batch[i])
>  				continue;
> -			error = xfs_blockgc_scan_inode(batch[i], eofb);
> -			xfs_irele(batch[i]);
> +			switch (tag) {
> +			case XFS_ICI_BLOCKGC_TAG:
> +				error = xfs_blockgc_scan_inode(batch[i], eofb);
> +				xfs_irele(batch[i]);
> +				break;
> +			case XFS_ICI_RECLAIM_TAG:
> +				xfs_reclaim_inode(batch[i], pag);
> +				error = 0;

Maybe move the irele into xfs_blockgc_scan_inode to make the calling
conventions more similar?