On Sat, Jun 5, 2021 at 9:07 AM Mina Almasry [off-list ref] wrote:

The alloc_huge_page_vma() doesn't return error pointers, it returns
NULL.

There is an existing migrate_page_copy() which not only copies the page
contents, but also page state/metadata.  People could get confused that
'migrate_page_copy' and 'migrate_copy_huge_page' do not have the same
functionality.  Rename to 'copy_huge_page()' to make it less likely
folks get confused.

Fixes: 6a0badc266df ("mm, hugetlb: fix racy resv_huge_pages underflow on
UFFDIO_COPY")

I think the commit id is not stable. So this really should squash
the commit of "mm, hugetlb: fix racy resv_huge_pages underflow
on UFFDIO_COPY". But anyway,

Reviewed-by: Muchun Song <redacted>

Signed-off-by: Mina Almasry <redacted>
Cc: linux-mm@kvack.org
Cc: Mike Kravetz <redacted>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org