[patch for-4.11] mm, thp: fix setting of defer+madvise thp defrag mode

[David Rientjes]

Setting thp defrag mode of "defer+madvise" actually sets "defer" in the 
kernel due to the name similarity and the out-of-order way the string is 
checked in defrag_store().

Check the string in the correct order so that 
TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG is set appropriately for 
"defer+madvise".

Fixes: 21440d7eb904 ("mm, thp: add new defer+madvise defrag option") 
Signed-off-by: David Rientjes <rient...@google.com>
---
 mm/huge_memory.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -240,18 +240,18 @@ static ssize_t defrag_store(struct kobject *kobj,
                clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, 
&transparent_hugepage_flags);
                clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, 
&transparent_hugepage_flags);
                set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, 
&transparent_hugepage_flags);
-       } else if (!memcmp("defer", buf,
-                   min(sizeof("defer")-1, count))) {
-               clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, 
&transparent_hugepage_flags);
-               clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, 
&transparent_hugepage_flags);
-               clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, 
&transparent_hugepage_flags);
-               set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, 
&transparent_hugepage_flags);
        } else if (!memcmp("defer+madvise", buf,
                    min(sizeof("defer+madvise")-1, count))) {
                clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, 
&transparent_hugepage_flags);
                clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, 
&transparent_hugepage_flags);
                clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, 
&transparent_hugepage_flags);
                set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, 
&transparent_hugepage_flags);
+       } else if (!memcmp("defer", buf,
+                   min(sizeof("defer")-1, count))) {
+               clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, 
&transparent_hugepage_flags);
+               clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, 
&transparent_hugepage_flags);
+               clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, 
&transparent_hugepage_flags);
+               set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, 
&transparent_hugepage_flags);
        } else if (!memcmp("madvise", buf,
                           min(sizeof("madvise")-1, count))) {
                clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, 
&transparent_hugepage_flags);