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 A5F9390B84 for ; Fri, 23 Sep 2022 10:31:39 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 8EF822180E for ; Fri, 23 Sep 2022 10:31:39 +0200 (CEST) Received: from proxmox-new.maurer-it.com (proxmox-new.maurer-it.com [94.136.29.106]) (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 for ; Fri, 23 Sep 2022 10:31:38 +0200 (CEST) Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id 9214B40644 for ; Fri, 23 Sep 2022 10:31:38 +0200 (CEST) Date: Fri, 23 Sep 2022 10:31:37 +0200 From: Wolfgang Bumiller To: Dominik Csapak Cc: pve-devel@lists.proxmox.com Message-ID: <20220923083137.evlm3264dakglezg@wobu-vie.proxmox.com> References: <20220922141935.653179-1-d.csapak@proxmox.com> <20220922141935.653179-3-d.csapak@proxmox.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220922141935.653179-3-d.csapak@proxmox.com> X-SPAM-LEVEL: Spam detection results: 0 AWL 0.261 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% 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 Subject: Re: [pve-devel] [PATCH qemu-server v2 2/3] qmeventd: cancel 'forced cleanup' when normal cleanup succeeds X-BeenThere: pve-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox VE development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 23 Sep 2022 08:31:39 -0000 On Thu, Sep 22, 2022 at 04:19:34PM +0200, Dominik Csapak wrote: > instead of always sending a SIGKILL to the target pid. > It was not that much of a problem since the timeout previously was 5 > seconds and we used pifds where possible, thus the chance of killing the > wrong process was rather slim. > > Now we increased the timeout to 60s which makes the race a bit more likely > (when not using pidfds), so remove it from the 'forced_cleanups' list when > the normal cleanup succeeds. > > Signed-off-by: Dominik Csapak > --- > qmeventd/qmeventd.c | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > > diff --git a/qmeventd/qmeventd.c b/qmeventd/qmeventd.c > index 46bc7eb..eebc19d 100644 > --- a/qmeventd/qmeventd.c > +++ b/qmeventd/qmeventd.c > @@ -416,6 +416,22 @@ cleanup_qemu_client(struct Client *client) > } > } > > +static void > +remove_cleanup_data(struct CleanupData *data, struct Client *client) { > + if (data->pid == client->pid) { > + forced_cleanups = g_slist_remove(forced_cleanups, data); > + free(data); > + } > +} > + > +static void > +remove_from_forced_cleanup(struct Client *client) { > + if (g_slist_length(forced_cleanups) > 0) { > + VERBOSE_PRINT("removing %s from forced cleanups\n", client->qemu.vmid); > + g_slist_foreach(forced_cleanups, (GFunc)remove_cleanup_data, client); Foreach + remove feels awkward to me. Sure, it's a linked list and should be fine™, but I don't like the lack of documentation of interactions here as a non-glib user. (I mean, eg. for C++ iterator invalidation is *usually* documented...) Can't we just give `struct Client` a `struct CleanupData` pointer and call `g_slist_remove` right here without the iteration? Or better yet, your previous idea of dropping `CleanupData` sounds better. We should be able to just add `struct Client*` to the list, after all, according to the glib docs `g_slist_remove` should simply leave the list unchanged if the data is not part of the list, so when we free up the `Client` we could even call `g_slist_remove` unconditionally (though we'll know whether it's in there by having a timeout set then...) (or use `g_slist_find_custom`) > + } > +} > + > void > cleanup_client(struct Client *client) > { > @@ -442,6 +458,7 @@ cleanup_client(struct Client *client) > break; > } > > + remove_from_forced_cleanup(client); > free(client); > } > > -- > 2.30.2