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

From: Stephen Rothwell <[email-masked]>
Date: Mon, 11 Dec 2023 13:50:52 +1100

Hi all,

On Mon, 20 Nov 2023 15:22:27 +1100 Stephen Rothwell <[email-masked]> wrote:
>
> After merging the kvm tree, today's linux-next build (x86_64 allmodconfig)
> failed like this:
> 
> arch/x86/kvm/../../../virt/kvm/guest_memfd.c:306:10: error: 'const struct address_space_operations' has no member named 'error_remove_page'; did you mean 'error_remove_folio'?
>   306 |         .error_remove_page = kvm_gmem_error_page,
>       |          ^~~~~~~~~~~~~~~~~
>       |          error_remove_folio
> arch/x86/kvm/../../../virt/kvm/guest_memfd.c:306:30: error: initialization of 'int (*)(struct folio *)' from incompatible pointer type 'int (*)(struct address_space *, struct page *)' [-Werror=incompatible-pointer-types]
>   306 |         .error_remove_page = kvm_gmem_error_page,
>       |                              ^~~~~~~~~~~~~~~~~~~
> arch/x86/kvm/../../../virt/kvm/guest_memfd.c:306:30: note: (near initialization for 'kvm_gmem_aops.launder_folio')
> 
> Caused by commit
> 
>   640be5bc564f ("fs: convert error_remove_page to error_remove_folio")
> 
> from the mm tree intercting with commit
> 
>   a7800aa80ea4 ("KVM: Add KVM_CREATE_GUEST_MEMFD ioctl() for guest-specific backing memory")
> 
> I have applied the following supplied merge fix patch (thanks Andrew).
> 
> From: Andrew Morton <[email-masked]>
> Date: Fri, 17 Nov 2023 09:28:33 -0800
> Subject: [PATCH] fs: Convert error_remove_page to error_remove_folio
> 
> On Fri, 17 Nov 2023 16:14:47 +0000 "Matthew Wilcox (Oracle)" <[email-masked]> wrote:
> 
> > There were already assertions that we were not passing a tail page
> > to error_remove_page(), so make the compiler enforce that by converting
> > everything to pass and use a folio.
> >
> > Signed-off-by: Matthew Wilcox (Oracle) <[email-masked]>
> > ---
> >  Documentation/filesystems/locking.rst |  4 ++--
> >  Documentation/filesystems/vfs.rst     |  6 +++---
> >  block/fops.c                          |  2 +-
> >  fs/afs/write.c                        |  2 +-
> >  fs/bcachefs/fs.c                      |  2 +-
> >  fs/btrfs/inode.c                      |  2 +-
> >  fs/ceph/addr.c                        |  4 ++--
> >  fs/ext2/inode.c                       |  2 +-
> >  fs/ext4/inode.c                       |  6 +++---
> >  fs/f2fs/compress.c                    |  2 +-
> >  fs/f2fs/inode.c                       |  2 +-
> >  fs/gfs2/aops.c                        |  4 ++--
> >  fs/hugetlbfs/inode.c                  |  6 +++---
> >  fs/nfs/file.c                         |  2 +-
> >  fs/ntfs/aops.c                        |  6 +++---
> >  fs/ocfs2/aops.c                       |  2 +-
> >  fs/xfs/xfs_aops.c                     |  2 +-
> >  fs/zonefs/file.c                      |  2 +-
> >  include/linux/fs.h                    |  2 +-
> >  include/linux/mm.h                    |  3 ++-
> >  mm/memory-failure.c                   | 10 +++++-----
> >  mm/shmem.c                            |  6 +++---
> >  mm/truncate.c                         |  9 ++++-----
> >  virt/kvm/guest_memfd.c                |  9 +++++----  
> 
> virt/kvm/guest_memfd.c exists only in the KVM tree (and hence
> linux-next).  So I assume Stephen will use the change from this patch
> when doing his resolution.
> 
> This:
> ---
Now this:

 virt/kvm/guest_memfd.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c
index c2e2371720a9..c23ce219e21c 100644
--- a/virt/kvm/guest_memfd.c
+++ b/virt/kvm/guest_memfd.c
@@ -267,7 +267,8 @@ static int kvm_gmem_migrate_folio(struct address_space *mapping,
 	return -EINVAL;
 }
 
-static int kvm_gmem_error_page(struct address_space *mapping, struct page *page)
+static int kvm_gmem_error_folio(struct address_space *mapping,
+		struct folio *folio)
 {
 	struct list_head *gmem_list = &mapping->private_list;
 	struct kvm_gmem *gmem;
@@ -275,8 +276,8 @@ static int kvm_gmem_error_page(struct address_space *mapping, struct page *page)
 
 	filemap_invalidate_lock_shared(mapping);
 
-	start = page->index;
-	end = start + thp_nr_pages(page);
+	start = folio->index;
+	end = start + folio_nr_pages(folio);
 
 	list_for_each_entry(gmem, gmem_list, entry)
 		kvm_gmem_invalidate_begin(gmem, start, end);
@@ -301,7 +302,7 @@ static int kvm_gmem_error_page(struct address_space *mapping, struct page *page)
 static const struct address_space_operations kvm_gmem_aops = {
 	.dirty_folio = noop_dirty_folio,
 	.migrate_folio	= kvm_gmem_migrate_folio,
-	.error_remove_page = kvm_gmem_error_page,
+	.error_remove_folio = kvm_gmem_error_folio,
 };
 
 static int kvm_gmem_getattr(struct mnt_idmap *idmap, const struct path *path,

-- 
Cheers,
Stephen Rothwell