mm: split free page with properly free memory accounting and without race

In isolate_single_pageblock(), free pages are checked without holding zone
lock, but they can go away in split_free_page() when zone lock is held.
Check the free page and its order again in split_free_page() when zone lock
is held. Recheck the page if the free page is gone under zone lock.

In addition, in split_free_page(), the free page was deleted from the page
list without changing free page accounting. Add the missing free page
accounting code.

Fix the type of order parameter in split_free_page().

Link: https://lore.kernel.org/lkml/[email protected]/
Link: https://lkml.kernel.org/r/[email protected]
Fixes: b2c9e2fbba32 ("mm: make alloc_contig_range work at pageblock granularity")
Signed-off-by: Zi Yan <[email protected]>
Reported-by: Doug Berger <[email protected]>
  Link: https://lore.kernel.org/linux-mm/[email protected]/
Cc: David Hildenbrand <[email protected]>
Cc: Qian Cai <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Eric Ren <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Christophe Leroy <[email protected]>
Cc: Marek Szyprowski <[email protected]>
Cc: Michael Walle <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions