1 files changed, 6 insertions, 0 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index 2d35772..fa4fa6c 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1068,6 +1068,12 @@ int shmem_lock(struct file *file, int lock, struct user_struct *user)
 		user_shm_unlock(inode->i_size, user);
 		info->flags &= ~VM_LOCKED;
 		mapping_clear_unevictable(file->f_mapping);
+		/*
+		 * Ensure that a racing putback_lru_page() can see
+		 * the pages of this mapping are evictable when we
+		 * skip them due to !PageLRU during the scan.
+		 */
+		smp_mb__after_clear_bit();
 		scan_mapping_unevictable_pages(file->f_mapping);
 	}
 	retval = 0;