mm: hwpoison: refactor refcount check handling

stable inclusion
from stable-v5.15.86
commit a62b1bc603a1ded739e7cf543da29a3eb93cc534
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6AR36
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a62b1bc603a1ded739e7cf543da29a3eb93cc534

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

commit dd0f230a upstream.

Memory failure will report failure if the page still has extra pinned
refcount other than from hwpoison after the handler is done.  Actually
the check is not necessary for all handlers, so move the check into
specific handlers.  This would make the following keeping shmem page in
page cache patch easier.

There may be expected extra pin for some cases, for example, when the
page is dirty and in swapcache.

Link: https://lkml.kernel.org/r/20211020210755.23964-5-shy828301@gmail.com


Signed-off-by: Yang Shi <shy828301@gmail.com>
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Suggested-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ze Zuo <zuoze1@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>