Re: [PATCH v8 02/11] block: allow blk-zoned devices to have non-power-of-2 zone size

From: Bart Van Assche
Date: Thu Jul 28 2022 - 09:29:18 EST


On 7/28/22 05:11, Pankaj Raghav wrote:
On 2022-07-28 01:16, Bart Van Assche wrote:
The bdev_is_zone_start() name seems more clear to me than
bdev_is_zone_aligned(). Has there already been a discussion about which
name to use for this function?

The reason I did s/bdev_is_zone_start/bdev_is_zone_aligned is that this
name makes more sense for also checking if a given size is a multiple of
zone sectors for e.g., used in PATCH 9:

- if (len & (zone_sectors - 1)) {
+ if (!bdev_is_zone_aligned(bdev, len)) {

I felt `bdev_is_zone_aligned` fits the use case of checking if the
sector starts at the start of a zone and also check if a given length of
sectors also align with the zone sectors. bdev_is_zone_start does not
make the intention clear for the latter use case IMO.

But I am fine with going back to bdev_is_zone_start if you and Damien
feel strongly otherwise.
The "zone start LBA" terminology occurs in ZBC-1, ZBC-2 and ZNS but "zone aligned" not. I prefer "zone start" because it is clear, unambiguous and because it has the same meaning as in the corresponding standards documents. I propose to proceed as follows for checking whether a number of LBAs is a multiple of the zone length:
* Either use bdev_is_zone_start() directly.
* Or introduce a synonym for bdev_is_zone_start() with an appropriate name, e.g. bdev_is_zone_len_multiple().

Thanks,

Bart.