Re: [dm-devel] [PATCH 06/11] block: Introduce BLKGETZONESZ ioctl

Bart Van Assche <bvanassche@xxxxxxx> · Wed, 10 Oct 2018 09:53:26 -0700

On Wed, 2018-10-10 at 10:52 +-0900, Damien Le Moal wrote:
+AD4  +ACM-define BLKREPORTZONE	+AF8-IOWR(0x12, 130, struct blk+AF8-zone+AF8-report)
+AD4  +ACM-define BLKRESETZONE	+AF8-IOW(0x12, 131, struct blk+AF8-zone+AF8-range)
+AD4 +-+ACM-define BLKGETZONESZ	+AF8-IOW(0x12, 132, unsigned int)

>From Documentation/ioctl/botching-up-ioctls.txt, a collection of lessons learned
the hard way about ioctls:

 +ACo Only use fixed sized integers. To avoid conflicts with typedefs in userspace
   the kernel has special types like +AF8AXw-u32, +AF8AXw-s64. Use them.

Please follow that advice.

Thanks,

Bart.