On Wed, Jul 22, 2020 at 01:02:14PM +0000, Damien Le Moal wrote:

That is the general idea. But Christoph point was that reporting the effective
write offset back to user space can be done not only for zone append, but also
for regular FS/files that are open with O_APPEND and being written with AIOs,
legacy or io_uring. Since for this case, the aio->aio_offset field is ignored
and the kiocb pos is initialized with the file size, then incremented with size
for the next AIO, the user never actually sees the actual write offset of its
AIOs. Reporting that back for regular files too can be useful, even though
current application can do without this (or do not use O_APPEND because it is
lacking).

Christoph, please loudly shout at me if I misunderstood you :)

I'd never shout at you :)  But yes, this is correct.