tree b15695f003f5a9b3bee306ddd5047d190aaf8321
parent d6646dddccb1aae08f60717b5b6743c513c37299
author Amaury Denoyelle <adenoyelle@haproxy.com> 1682518332 +0200
committer Amaury Denoyelle <adenoyelle@haproxy.com> 1682524222 +0200

BUG/MINOR: quic: fix race on quic_conns list during affinity rebind

Each quic_conn are attached in a global thread-local quic_conns list
used for "show quic" command. During thread rebinding, a connection is
detached from its local list instance and moved to its new thread list.
However this operation is not thread-safe and may cause a race
condition.

To fix this, only remove the connection from its list inside
qc_set_tid_affinity(). The connection is inserted only after in
qc_finalize_affinity_rebind() on the new thread instance thus prevented
a race condition. One impact of this is that a connection will be
invisible during rebinding for "show quic".

A connection must not transition to closing state in between this two
steps or else cleanup via quic_handle_stopping() may not miss it. To
ensure this, this patch relies on the previous commit :
  commit d6646dddccb1aae08f60717b5b6743c513c37299
  MINOR: quic: finalize affinity change as soon as possible

This should be backported up to 2.7.