From: Miaohe Lin <linmiaohe@xxxxxxxxxx> Subject: shmem: include header file to declare swap_info It's bad to extern swap_info[] in .c. Include corresponding header file instead. Link: https://lkml.kernel.org/r/20210812120350.49801-5-linmiaohe@xxxxxxxxxx Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/shmem.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/mm/shmem.c~shmem-include-header-file-to-declare-swap_info +++ a/mm/shmem.c @@ -38,6 +38,7 @@ #include <linux/hugetlb.h> #include <linux/frontswap.h> #include <linux/fs_parser.h> +#include <linux/swapfile.h> static struct vfsmount *shm_mnt; @@ -1152,8 +1153,6 @@ static void shmem_evict_inode(struct ino clear_inode(inode); } -extern struct swap_info_struct *swap_info[]; - static int shmem_find_swap_entries(struct address_space *mapping, pgoff_t start, unsigned int nr_entries, struct page **entries, pgoff_t *indices, _