mm/compaction: correctly return failure with bogus compound_order in strict mode

In strict mode, we should return 0 if there is any hole in pageblock.  If
we successfully isolated pages at beginning at pageblock and then have a
bogus compound_order outside pageblock in next page.  We will abort search
loop with blockpfn > end_pfn.  Although we will limit blockpfn to end_pfn,
we will treat it as a successful isolation in strict mode as blockpfn is
not < end_pfn and return partial isolated pages.  Then
isolate_freepages_range may success unexpectly with hole in isolated
range.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 9fcd6d2e052e ("mm, compaction: skip compound pages by order in free scanner")
Signed-off-by: Kemeng Shi <[email protected]>
Reviewed-by: Baolin Wang <[email protected]>
Acked-by: Mel Gorman <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions