Re: [PATCH V2] ublk: zoned: support REQ_OP_ZONE_RESET_ALL

[Niklas Cassel <Niklas.Cassel@wdc.com>]

On Thu, Aug 10, 2023 at 10:00:14PM +0800, Ming Lei wrote:
> On Thu, Aug 10, 2023 at 01:10:30PM +0000, Niklas Cassel wrote:
> > On Thu, Aug 10, 2023 at 08:43:26PM +0800, Ming Lei wrote:

(snip)
 
> UBLK_IO_OP_ZONE_* is part of ublk UAPI, but REQ_OP_ZONE_* is just kernel
> internal definition which may be changed time by time, so we can't use
> REQ_OP_ZONE_* directly.
> 
> Here you can think of UBLK_IO_OP_ZONE_* as interface between driver and
> hardware, so UBLK_IO_OP_ZONE_* has to be defined independently.
> 
> > but if you want to keep this pattern, then perhaps you want
> > to define UBLK_IO_OP_ZONE_RESET_ALL to 17.
> 
> Why do you think that 17 is better than 14?

I never said that it was better :)
I even said: "I don't see any obvious advantage of keeping them the same" :)

Just that it would follow the existing pattern of keeping
UBLK_IO_OP_ZONE_* in sync with REQ_OP_ZONE_*.


> 
> I'd rather use 14 to fill the hole, meantime the two ZONE_RESET OPs
> can be kept together.

Ok, but then, considering that UBLK_IO_OP_ZONE_* is not part of any official
kernel release, and that the highest UBLK_IO_OP is currently defined as 5:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/uapi/linux/ublk_cmd.h?h=v6.5-rc5#n237

why not define:
+#define		UBLK_IO_OP_ZONE_OPEN		6
+#define		UBLK_IO_OP_ZONE_CLOSE		7
+#define		UBLK_IO_OP_ZONE_FINISH		8
+#define		UBLK_IO_OP_ZONE_APPEND		9
+#define		UBLK_IO_OP_ZONE_RESET		10
+#define		UBLK_IO_OP_ZONE_RESET_ALL	11

instead of, like it currently is in linux-block/for-next (this patch included):

+#define		UBLK_IO_OP_ZONE_OPEN		10
+#define		UBLK_IO_OP_ZONE_CLOSE		11
+#define		UBLK_IO_OP_ZONE_FINISH		12
+#define		UBLK_IO_OP_ZONE_APPEND		13
+#define		UBLK_IO_OP_ZONE_RESET_ALL	14
+#define		UBLK_IO_OP_ZONE_RESET		15

Because, even after this patch, you would still have a hole between
UBLK_IO_OP_ value 5 and 10.


Kind regards,
Niklas