On 11/06/2021 14:40, Qu Wenruo wrote:

On 2021/6/11 下午4:19, Johannes Thumshirn wrote:

quoted

On 11/06/2021 10:16, Qu Wenruo wrote:

quoted

Did you mean that for the bio_add_zone_append_page(), it may return less
bytes than we expected?
Even if our compressed write is ensured to be smaller than 128K?

No it either adds the number of requested pages or it fails (I think there's
and effort going on to make bio_add_page() and friends return bool so this is
less confusing).

BTW, I have a question about the add or not at all behavior.

One of my concern is, if we're at the zone boundary (or what's the
proper term?), and we want to add 4 sectors, but the zone boundary can
only add one sector, and if we just submit current bio, wouldn't it
cause some problem?

E.g. we leave a one sector gap for the current zone.
Will that be a problem?

The zoned allocator will take care of it. It'll fill the zone as good as possible
or move the allocation to a new block group on a new zone.