From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) by lore.proxmox.com (Postfix) with ESMTPS id 4BE111FF140 for ; Fri, 24 Apr 2026 10:54:57 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 27A2710589; Fri, 24 Apr 2026 10:54:57 +0200 (CEST) Date: Fri, 24 Apr 2026 10:54:52 +0200 From: Arthur Bied-Charreton To: Shannon Sterz Subject: Re: [PATCH proxmox v4 03/24] notify: smtp: Introduce state management Message-ID: References: <20260421115957.402589-1-a.bied-charreton@proxmox.com> <20260421115957.402589-4-a.bied-charreton@proxmox.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1777020803018 X-SPAM-LEVEL: Spam detection results: 0 AWL 0.767 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Message-ID-Hash: QU5XIJRPEQCE34YMDZXHGDMVCHQM57AY X-Message-ID-Hash: QU5XIJRPEQCE34YMDZXHGDMVCHQM57AY X-MailFrom: a.bied-charreton@proxmox.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: pbs-devel@lists.proxmox.com, pve-devel@lists.proxmox.com X-Mailman-Version: 3.3.10 Precedence: list List-Id: Proxmox VE development discussion List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On Fri, Apr 24, 2026 at 10:04:49AM +0200, Shannon Sterz wrote: > On Fri Apr 24, 2026 at 9:47 AM CEST, Arthur Bied-Charreton wrote: > > On Thu, Apr 23, 2026 at 02:24:37PM +0200, Shannon Sterz wrote: > >> On Tue Apr 21, 2026 at 1:59 PM CEST, Arthur Bied-Charreton wrote: > > -->8 snip 8<-- > > >> > + /// The state file does not need to be locked, it is okay to just let the faster node "win" > >> > + /// as long as the invariants documented by [`smtp::xoauth2::get_microsoft_token`] and > >> > + /// [`smtp::xoauth2::get_google_token`] hold, see those functions' doc comments for details. > >> > + #[cfg(feature = "smtp")] > >> > + fn save_oauth_state(&self, endpoint_name: &str, state: Option) -> Result<(), Error>; > >> > >> i'm not sure the no-locking approach here works. if i understand > >> correctly, the following example is possible: > >> > >> A: calls `trigger_state_refresh`, does not lock the notification config > >> B: calls `delete_smtp_endpoint`, locks the notification config > >> A: reads the refresh token > >> B: removes the endpoint and state file > >> A: finishes refreshing the token and safes it out > >> > >> if we extend that example with a C that adds an endpoint with the same > >> name after B finishes, then it would suddenly be left with a state file > >> from the previous endpoint. similar examples can also happen when > >> calling `build_transport` since that also includes a read & write cycle > >> of the state file. > >> > > Yes you are right, I may have been too focused on refresh token validity > > and overlooked this - thanks a lot for catching it! > > > >> if the state file were locked properly, B would fail to acquire the lock > >> when trying to delete it (or have to wait until A finishes). > >> > >> if this behaviour is fine, maybe this would benefit from some > >> documentation. > >> > > I will add locks in v5, I don't think we are gaining that much from a > > lock-free approach here, per-endpoint locking will be pretty cheap > > anyway. > > > > just to be sure, since i realized this is misleadingly phrased in my > initial message: make sure not to lock the state files themselves. > rather keep around a lock file that won't be removed if the state file > is removed. otherwise, you can run into a different kind of race between > deleting and writing threads. > That was clear, but thanks for the clarification still :) > we do this already for almost all other config files. if you are worried > about "polluting" the state directory here, you can consider putting > these lock files in a sub-directory on `/run`. though, this would > require extra care to integrate it with all products. hope that makes > sense and thanks for tackling this! > Yes, we already have the Context trait in proxmox-notify, will add a lock_oauth_state method that allows to handle this on a per-product basis. I was thinking of putting them into /run for PBS and PDM, but for PVE they should be in /etc/pve right? > -->8 snip 8<--