Extern or forward variable declaration arch/arm/include/asm/io.h, line 460 [usage...] arch/arm64/include/asm/io.h, line 208 [usage...] arch/x86/include/asm/io.h, line 332 [usage...] include/linux/blkdev.h, line 217 [usage...] include/linux/device-mapper.h, line 20 [usage...] Structure include/linux/blk_types.h, line 23 [usage...] Local variable drivers/block/floppy.c, line 3796 [usage...] fs/logfs/dev_bdev.c, line 20 [usage...] net/ceph/messenger.c, line 840 [usage...] net/ceph/messenger.c, line 865 [usage...] Class, struct, or union member drivers/md/dm-bufio.c, line 152 [usage...]