According to the documentation in include/uapi/asm-generic/ioctl.h, _IOW means userspace is writing and kernel is reading, and _IOR means userspace is reading and kernel is writing.
In case of these two ioctls, kernel is writing and userspace is reading, so they have to be _IOR instead of _IOW. Fixes: 72cd87576d1d8 ("block: Introduce BLKGETZONESZ ioctl") Fixes: 65e4e3eee83d7 ("block: Introduce BLKGETNRZONES ioctl") Signed-off-by: Dmitry V. Levin <l...@altlinux.org> --- Since both ioctls were introduced after 4.19, please make sure they are fixed in 4.20. Thanks. include/uapi/linux/blkzoned.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/uapi/linux/blkzoned.h b/include/uapi/linux/blkzoned.h index 8f08ff9bdea0..6fa38d001d84 100644 --- a/include/uapi/linux/blkzoned.h +++ b/include/uapi/linux/blkzoned.h @@ -141,7 +141,7 @@ struct blk_zone_range { */ #define BLKREPORTZONE _IOWR(0x12, 130, struct blk_zone_report) #define BLKRESETZONE _IOW(0x12, 131, struct blk_zone_range) -#define BLKGETZONESZ _IOW(0x12, 132, __u32) -#define BLKGETNRZONES _IOW(0x12, 133, __u32) +#define BLKGETZONESZ _IOR(0x12, 132, __u32) +#define BLKGETNRZONES _IOR(0x12, 133, __u32) #endif /* _UAPI_BLKZONED_H */ -- ldv