From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.proxmox.com (Postfix) with ESMTPS id 5B04761816 for ; Thu, 17 Dec 2020 17:17:33 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 5138028C60 for ; Thu, 17 Dec 2020 17:17:03 +0100 (CET) Received: from proxmox-new.maurer-it.com (proxmox-new.maurer-it.com [212.186.127.180]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by firstgate.proxmox.com (Proxmox) with ESMTPS id AF2B128C53 for ; Thu, 17 Dec 2020 17:17:02 +0100 (CET) Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id 74DE945259 for ; Thu, 17 Dec 2020 17:17:02 +0100 (CET) To: Proxmox Backup Server development discussion , Dominik Csapak , Fabian Ebner References: <20201217145018.2902-1-d.csapak@proxmox.com> From: Thomas Lamprecht Message-ID: <68cad25d-5e78-8cf9-261e-f130205bd1f9@proxmox.com> Date: Thu, 17 Dec 2020 17:17:00 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:82.0) Gecko/20100101 Thunderbird/82.0 MIME-Version: 1.0 In-Reply-To: <20201217145018.2902-1-d.csapak@proxmox.com> Content-Type: text/plain; charset=UTF-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit X-SPAM-LEVEL: Spam detection results: 0 AWL -0.065 Adjusted score from AWL reputation of From: address KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment NICE_REPLY_A -0.001 Looks like a legit reply (A) RCVD_IN_DNSWL_MED -2.3 Sender listed at https://www.dnswl.org/, medium trust SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record URIBL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to URIBL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [daemon.rs] Subject: Re: [pbs-devel] [PATCH proxmox-backup v2] tools/daemon: improve reload behaviour X-BeenThere: pbs-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox Backup Server development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 17 Dec 2020 16:17:33 -0000 On 17/12/2020 15:50, Dominik Csapak wrote: > it seems that sometimes, the child process signal gets handled > before the parent process signal. Systemd then ignores the > childs signal (finished reloading) and only after going into > reloading state because of the parent. this will never finish. > > Instead, wait for the state to change to 'reloading' after sending > that signal in the parent, an only fork afterwards. This way > we ensure that systemd knows about the reloading before actually trying > to do it. > > Signed-off-by: Dominik Csapak > --- > changes from v1: > * introduce wait_service_is_(not_)state > it is a bit more generic > has a better name > * factor the common code out into get_service_state > that seems much nicer, thanks! @Fabian can you please redo your testing (1.5k is maybe a bit much in light of the changes between v1 and v2 I'm happy with 100 ^^ too) I'm quite confident in the patch, but this is not something I'd like to touch again soon, so better we check it a bit to much than to less :) > src/tools/daemon.rs | 45 ++++++++++++++++++++++++++++----------------- > 1 file changed, 28 insertions(+), 17 deletions(-) > > diff --git a/src/tools/daemon.rs b/src/tools/daemon.rs > index 6bb4a41b..0e3a174a 100644 > --- a/src/tools/daemon.rs > +++ b/src/tools/daemon.rs > @@ -291,6 +291,7 @@ where > if let Err(e) = systemd_notify(SystemdNotify::Reloading) { > log::error!("failed to notify systemd about the state change: {}", e); > } > + wait_service_is_state(service_name, "reloading").await?; > if let Err(e) = reloader.take().unwrap().fork_restart() { > log::error!("error during reload: {}", e); > let _ = systemd_notify(SystemdNotify::Status("error during reload".to_string())); > @@ -305,7 +306,7 @@ where > > // FIXME: this is a hack, replace with sd_notify_barrier when available > if server::is_reload_request() { > - wait_service_is_active(service_name).await?; > + wait_service_is_not_state(service_name, "reloading").await?; > } > > log::info!("daemon shut down..."); > @@ -313,26 +314,36 @@ where > } > > // hack, do not use if unsure! > -async fn wait_service_is_active(service: &str) -> Result<(), Error> { > +async fn get_service_state(service: &str) -> Result { > + let text = match tokio::process::Command::new("systemctl") > + .args(&["is-active", service]) > + .output() > + .await > + { > + Ok(output) => match String::from_utf8(output.stdout) { > + Ok(text) => text, > + Err(err) => bail!("output of 'systemctl is-active' not valid UTF-8 - {}", err), > + }, > + Err(err) => bail!("executing 'systemctl is-active' failed - {}", err), > + }; > + > + Ok(text.trim().trim_start().to_string()) > +} > + > +async fn wait_service_is_state(service: &str, state: &str) -> Result<(), Error> { > tokio::time::delay_for(std::time::Duration::new(1, 0)).await; > - loop { > - let text = match tokio::process::Command::new("systemctl") > - .args(&["is-active", service]) > - .output() > - .await > - { > - Ok(output) => match String::from_utf8(output.stdout) { > - Ok(text) => text, > - Err(err) => bail!("output of 'systemctl is-active' not valid UTF-8 - {}", err), > - }, > - Err(err) => bail!("executing 'systemctl is-active' failed - {}", err), > - }; > + while get_service_state(service).await? != state { > + tokio::time::delay_for(std::time::Duration::new(5, 0)).await; > + } > + Ok(()) > +} > > - if text.trim().trim_start() != "reloading" { > - return Ok(()); > - } > +async fn wait_service_is_not_state(service: &str, state: &str) -> Result<(), Error> { > + tokio::time::delay_for(std::time::Duration::new(1, 0)).await; > + while get_service_state(service).await? == state { > tokio::time::delay_for(std::time::Duration::new(5, 0)).await; > } > + Ok(()) > } > > #[link(name = "systemd")] >