CMA: make putback_lru_pages() call conditional

As per documentation and other places calling putback_lru_pages(),
putback_lru_pages() is called on error only.  Make the CMA code behave
consistently.

[akpm@linux-foundation.org: remove a test-n-branch in the wrapup code]
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 3 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index d1107adf174a..804cc62ab72f 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5806,9 +5806,11 @@ static int __alloc_contig_migrate_range(struct compact_control *cc,
                                     0, false, MIGRATE_SYNC,
                                     MR_CMA);
         }
-
-        putback_movable_pages(&cc->migratepages);
-        return ret > 0 ? 0 : ret;
+        if (ret < 0) {
+                putback_movable_pages(&cc->migratepages);
+                return ret;
+        }
+        return 0;
 }
 
 /**