mm/swapfile: skip HugeTLB pages for unuse_vma

stable inclusion
from stable-v5.10.228
commit 417d5838ca73c6331ae2fe692fab6c25c00d9a0b
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IAXWWM

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=417d5838ca73c6331ae2fe692fab6c25c00d9a0b

--------------------------------

commit 7528c4fb1237512ee18049f852f014eba80bbe8d upstream.

I got a bad pud error and lost a 1GB HugeTLB when calling swapoff.  The
problem can be reproduced by the following steps:

 1. Allocate an anonymous 1GB HugeTLB and some other anonymous memory.
 2. Swapout the above anonymous memory.
 3. run swapoff and we will get a bad pud error in kernel message:

  mm/pgtable-generic.c:42: bad pud 00000000743d215d(84000001400000e7)

We can tell that pud_clear_bad is called by pud_none_or_clear_bad in
unuse_pud_range() by ftrace.  And therefore the HugeTLB pages will never
be freed because we lost it from page table.  We can skip HugeTLB pages
for unuse_vma to fix it.

Link: https://lkml.kernel.org/r/20241015014521.570237-1-liushixin2@huawei.com


Fixes: 0fe6e20b ("hugetlb, rmap: add reverse mapping for hugepage")
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Acked-by: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Liu Shixin <liushixin2@huawei.com>