pfsync: Unconditionally push packets when requesting state updates

[kp]

Summary

When we request a bulk sync we need to ensure we actually send out that
request, not just buffer it until we have enough data to send a full
packet.

PR: 254236
Submitted by: topical AT gmx.net
MFC after: 2 weeks

[glebius]

I would suggest to change pfsync_request_update() to unconditionally make pfsync_push() on the bucket, regardless of request type (bulk or a single state). This will allow for some batching and shorten stuff executed from the callout context. After this change the call to pfsync_sendout() from the pfsync_request_update() can be changed to 0 in first arguemnt.

[kp]

In D29271#655463, @glebius wrote:

I would suggest to change pfsync_request_update() to unconditionally make pfsync_push() on the bucket, regardless of request type (bulk or a single state). This will allow for some batching and shorten stuff executed from the callout context. After this change the call to pfsync_sendout() from the pfsync_request_update() can be changed to 0 in first arguemnt.

Yeah, that makes sense too. Requesting state updates should be very rare anyway, so not buffering them should be safe.