Subject: linux-next: build failure after merge of the folio tree

From: Stephen Rothwell <[email-masked]>
Date: Tue, 4 Jan 2022 18:29:25 +1100

Hi all,

After merging the folio tree, today's linux-next build (powerpc
ppc64_defconfig) failed like this:

In file included from include/linux/socket.h:8,
                 from include/linux/compat.h:15,
                 from arch/powerpc/kernel/asm-offsets.c:12:
include/linux/uio.h: In function 'copy_folio_to_iter':
include/linux/uio.h:153:33: error: invalid use of undefined type 'struct folio'
  153 |  return copy_page_to_iter(&folio->page, offset, bytes, i);
      |                                 ^~

Caused by commit

  442f739136ee ("iov_iter: Add copy_folio_to_iter()")

struct folio is only forward declared in uio.h.  Presumably other builds
include mm_types.h indirectly.

I have used the folio tree from next-20211224 for today.

-- 
Cheers,
Stephen Rothwell