mm: mlock: avoid folio_within_range() on KSM pages

mainline inclusion
from mainline-v6.7-rc1
commit b1454b463c217e5bc553acc44b2389d9257c9708
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8YQMW

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b1454b463c217e5bc553acc44b2389d9257c9708

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

Since commit dc68badcede4 ("mm: mlock: update mlock_pte_range to handle
large folio") I've just occasionally seen VM_WARN_ON_FOLIO(folio_test_ksm)
warnings from folio_within_range(), in a splurge after testing with KSM
hyperactive.

folio_referenced_one()'s use of folio_within_vma() is safe because it
checks folio_test_large() first; but allow_mlock_munlock() needs to do the
same to avoid those warnings (or check !folio_test_ksm() itself?  Or move
either check into folio_within_range()?  Hard to tell without more
examples of its use).

Link: https://lkml.kernel.org/r/23852f6a-5bfa-1ffd-30db-30c5560ad426@google.com


Fixes: dc68badcede4 ("mm: mlock: update mlock_pte_range to handle large folio")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Stefan Roesch <shr@devkernel.io>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>