From e1d8c966dbf11afcac1d115f3fca5a29060bba18 Mon Sep 17 00:00:00 2001 From: Miaohe Lin Date: Fri, 5 Nov 2021 13:42:16 -0700 Subject: mm/page_isolation: fix potential missing call to unset_migratetype_isolate() In start_isolate_page_range() undo path, pfn_to_online_page() just checks the first pfn in a pageblock while __first_valid_page() will traverse the pageblock until the first online pfn is found. So we may miss the call to unset_migratetype_isolate() in undo path and pages will remain isolated unexpectedly. Fix this by calling undo_isolate_page_range() and this will also help to simplify the code further. Note we shouldn't ever trigger it because MAX_ORDER-1 aligned pfn ranges shouldn't contain memory holes now. Link: https://lkml.kernel.org/r/20210914114348.15569-1-linmiaohe@huawei.com Fixes: 2ce13640b3f4 ("mm: __first_valid_page skip over offline pages") Signed-off-by: Miaohe Lin Reviewed-by: David Hildenbrand Cc: Michal Hocko Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_isolation.c | 20 +++----------------- 1 file changed, 3 insertions(+), 17 deletions(-) (limited to 'mm/page_isolation.c') diff --git a/mm/page_isolation.c b/mm/page_isolation.c index a95c2c6562d0..f93cc63d8fa1 100644 --- a/mm/page_isolation.c +++ b/mm/page_isolation.c @@ -183,7 +183,6 @@ int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn, unsigned migratetype, int flags) { unsigned long pfn; - unsigned long undo_pfn; struct page *page; BUG_ON(!IS_ALIGNED(start_pfn, pageblock_nr_pages)); @@ -193,25 +192,12 @@ int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn, pfn < end_pfn; pfn += pageblock_nr_pages) { page = __first_valid_page(pfn, pageblock_nr_pages); - if (page) { - if (set_migratetype_isolate(page, migratetype, flags)) { - undo_pfn = pfn; - goto undo; - } + if (page && set_migratetype_isolate(page, migratetype, flags)) { + undo_isolate_page_range(start_pfn, pfn, migratetype); + return -EBUSY; } } return 0; -undo: - for (pfn = start_pfn; - pfn < undo_pfn; - pfn += pageblock_nr_pages) { - struct page *page = pfn_to_online_page(pfn); - if (!page) - continue; - unset_migratetype_isolate(page, migratetype); - } - - return -EBUSY; } /* -- cgit