On 2021-04-19 2:45 a.m., Christoph Hellwig wrote:

On Sat, Apr 17, 2021 at 11:33:23AM +0900, Damien Le Moal wrote:

quoted

Synchronous writes to sequential zone files cannot use zone append
operations if the underlying zoned device queue limit
max_zone_append_sectors is 0, indicating that the device does not
support this operation. In this case, fall back to using regular write
operations.

Zone append is a mandatory feature of the zoned device API.

So a hack required for ZNS and not needed by ZBC and ZAC becomes
a "mandatory feature" in a Linux API. Like many hacks, that one might
come back to bite you :-)

Doug Gilbert