tree a4453cebc62e97905c538b90f6a919dcecd64c48
parent 640e253698b1016f115552d1d5bbb81e5263377d
author Willy Tarreau <w@1wt.eu> 1673866021 +0100
committer Willy Tarreau <w@1wt.eu> 1673874050 +0100
encoding latin1

BUG/MINOR: listeners: fix suspend/resume of inherited FDs

FDs inherited from a parent process do not deal well with suspend/resume
since commit 59b5da487 ("BUG/MEDIUM: listener: never suspend inherited
sockets") introduced in 2.3. The problem is that we now report that they
cannot be suspended at all, and they return a failure. As such, if a new
process fails to bind and sends SIGTTOU to the previous process, that
one will notice the failure and instantly switch to soft-stop, leaving
no chance to the new process to give up later and signal its failure.

What we need to do, however, is to stop receiving new connections from
such inherited FDs, which just means that the FD must be unsubscribed
from the poller (and resubscribed later if finally it has to stay).
With this a new process can start on the already bound FD without
problem thanks to the absence of polling, and when the old process
stops the new process will be alone on it.

This may be backported as far as 2.4.