public inbox for pbs-devel@lists.proxmox.com
 help / color / mirror / Atom feed
From: Dominik Csapak <d.csapak@proxmox.com>
To: pbs-devel@lists.proxmox.com
Subject: [pbs-devel] [PATCH proxmox] daemon: clean up middle process of double fork
Date: Fri, 29 Nov 2024 16:37:44 +0100	[thread overview]
Message-ID: <20241129153744.4128441-1-d.csapak@proxmox.com> (raw)

so we don't leave around a zombie process when the old daemon still
needs to run, because of e.g. a running task.

Since this is mostly a cosmetic issue though, only try a clean up
once, so we don't unnecessarily block or run into other issues here.
(It could happen that it didn't exit at that point, but it's very
unlikely.)

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
---
maybe the comment could be improved, but i tried to be not overly
verbose there, since it's not really an issue anyway

 proxmox-daemon/src/server.rs | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/proxmox-daemon/src/server.rs b/proxmox-daemon/src/server.rs
index efea9078..edc64795 100644
--- a/proxmox-daemon/src/server.rs
+++ b/proxmox-daemon/src/server.rs
@@ -165,10 +165,12 @@ impl Reloader {
                 // No matter how we managed to get here, this is the time where we bail out quickly:
                 unsafe { libc::_exit(-1) }
             }
-            Ok(ForkResult::Parent { child }) => {
+            Ok(ForkResult::Parent {
+                child: middle_child,
+            }) => {
                 log::debug!(
                     "forked off a new server (first pid: {}), waiting for 2nd pid",
-                    child
+                    middle_child
                 );
                 std::mem::drop(pnew);
                 let mut pold = std::fs::File::from(pold);
@@ -211,6 +213,13 @@ impl Reloader {
                     log::error!("child vanished during reload: {}", e);
                 }
 
+                // try exactly once to get rid of the zombie process of middle_child, but
+                // non blocking and without error handling, since it's just cosmetic
+                let _ = nix::sys::wait::waitpid(
+                    middle_child,
+                    Some(nix::sys::wait::WaitPidFlag::WNOHANG),
+                );
+
                 Ok(())
             }
             Err(e) => {
-- 
2.39.5



_______________________________________________
pbs-devel mailing list
pbs-devel@lists.proxmox.com
https://lists.proxmox.com/cgi-bin/mailman/listinfo/pbs-devel


             reply	other threads:[~2024-11-29 15:38 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-11-29 15:37 Dominik Csapak [this message]
2024-12-02  9:04 ` Fabian Grünbichler
2024-12-02 16:47 ` Thomas Lamprecht
2024-12-03  9:14   ` Dominik Csapak
2024-12-03  9:29     ` Thomas Lamprecht

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20241129153744.4128441-1-d.csapak@proxmox.com \
    --to=d.csapak@proxmox.com \
    --cc=pbs-devel@lists.proxmox.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
Service provided by Proxmox Server Solutions GmbH | Privacy | Legal