[PATCH 1/3] shmem: fix tmpfs to handle the huge= option properly

[Hugh Dickins]

From: Toshi Kani <toshi.kani@xxxxxxx>

shmem_get_unmapped_area() checks SHMEM_SB(sb)->huge incorrectly,
which leads to a reversed effect of "huge=" mount option.

Fix the check in shmem_get_unmapped_area().

Note, the default value of SHMEM_SB(sb)->huge remains as
SHMEM_HUGE_NEVER.  User will need to specify "huge=" option to
enable huge page mappings.

Reported-by: Hillf Danton <hillf.zj@xxxxxxxxxxxxxxx>
Signed-off-by: Toshi Kani <toshi.kani@xxxxxxx>
Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
---

 mm/shmem.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- 4.8-rc7/mm/shmem.c	2016-08-14 20:17:02.388843463 -0700
+++ linux/mm/shmem.c	2016-09-22 19:41:29.057848626 -0700
@@ -1980,7 +1980,7 @@ unsigned long shmem_get_unmapped_area(st
 				return addr;
 			sb = shm_mnt->mnt_sb;
 		}
-		if (SHMEM_SB(sb)->huge != SHMEM_HUGE_NEVER)
+		if (SHMEM_SB(sb)->huge == SHMEM_HUGE_NEVER)
 			return addr;
 	}