Re: [PATCH v4 7/7] hfsplus: switch address_space_operations on iomap-based support

[Christoph Hellwig <hch@lst.de>]

On Mon, Sep 14, 2026 at 04:39:41PM -0700, Viacheslav Dubeyko wrote:
>  /* Compare two extents keys, returns 0 on same, pos/neg for difference */
>  int hfsplus_ext_cmp_key(const hfsplus_btree_key *k1,
> @@ -275,6 +276,8 @@ int hfsplus_map_extent(struct inode *inode, u32 ablock, int create,
>  		*max_blocks = hfsplus_ext_find_block(hip->first_extents,
>  						     ablock,
>  						     dblock);
> +		if (!*max_blocks)
> +			return -EIO;

What is this for?  It feels like something that should go into a
well-documented prep patch.

> @@ -342,7 +348,7 @@ int hfsplus_get_block(struct inode *inode, sector_t iblock,
>  
>  	if (create) {
>  		set_buffer_new(bh_result);
> -		hip->phys_size += sb->s_blocksize;
> +		hip->phys_size = (loff_t)(iblock + 1) << sb->s_blocksize_bits;

How is this change related to iomap?

>  	if (inode->i_size > hip->phys_size) {
> -		struct address_space *mapping = inode->i_mapping;
> -		struct folio *folio;
> -		void *fsdata = NULL;
> -		loff_t size = inode->i_size;
> +		if (S_ISREG(inode->i_mode)) {
> +			res = hfsplus_iomap_cont_expand(inode, hip->phys_size,
> +							inode->i_size);
> +			if (res)
> +				return;
> +
> +			mark_inode_dirty(inode);
> +		} else {
> +			struct address_space *mapping = inode->i_mapping;
> +			struct folio *folio;
> +			void *fsdata = NULL;
> +
> +			res = hfsplus_write_begin(NULL, mapping,
> +						  inode->i_size, 0,
> +						  &folio, &fsdata);
> +			if (res)
> +				return;
> +
> +			res = generic_write_end(NULL, mapping,
> +						inode->i_size, 0, 0,
> +						folio, fsdata);
> +			if (res < 0)
> +				return;
> +
> +			mark_inode_dirty(inode);
> +		}

Is this for symlinks?  Any reason you can't pull in

  iomap: add iomap_symlink_write

that has been posted on fsdevel and use iomap for symlinks as well?