From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Add a forward declaration for struct gendisk when CONFIG_BLOCK is not set/enabled to prevent multiple (30 - 50) build warnings. In file included from ../kernel/sched/sched.h:39:0, from ../kernel/sched/core.c:9: ../include/linux/blkdev.h:1895:41: warning: 'struct gendisk' declared inside parameter list will not be visible outside of this definition or declaration unsigned long disk_start_io_acct(struct gendisk *disk, unsigned int sectors, ^~~~~~~ Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> Cc: linux-block@xxxxxxxxxxxxxxx --- include/linux/blkdev.h | 1 + 1 file changed, 1 insertion(+) --- linux-next-20200528.orig/include/linux/blkdev.h +++ linux-next-20200528/include/linux/blkdev.h @@ -1836,6 +1836,7 @@ static inline bool blk_req_can_dispatch_ #else /* CONFIG_BLOCK */ struct block_device; +struct gendisk; /* * stubs for when the block layer is configured out