mm/migration: fix potential page refcounts leak in migrate_pages

In -ENOMEM case, there might be some subpages of fail-to-migrate THPs left
in thp_split_pages list.  We should move them back to migration list so
that they could be put back to the right list by the caller otherwise the
page refcnt will be leaked here.  Also adjust nr_failed and nr_thp_failed
accordingly to make vm events account more accurate.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: b5bade978e9b ("mm: migrate: fix the return value of migrate_pages()")
Signed-off-by: Miaohe Lin <[email protected]>
Reviewed-by: Zi Yan <[email protected]>
Reviewed-by: "Huang, Ying" <[email protected]>
Reviewed-by: Baolin Wang <[email protected]>
Reviewed-by: Muchun Song <[email protected]>
Cc: Alistair Popple <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions