[PATCH 04/25] fs: Provide infrastructure for dynamic BDIs in filesystems

[Christoph Hellwig]

> +	if (sb->s_iflags & SB_I_DYNBDI) {
> +		bdi_put(sb->s_bdi);
> +		sb->s_bdi = &noop_backing_dev_info;

At some point I'd really like to get rid of noop_backing_dev_info and
have a NULL here..

Otherwise this looks fine..

Reviewed-by: Christoph Hellwig <hch at lst.de>