From patchwork Thu Oct 5 12:36:35 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Breno Leitao X-Patchwork-Id: 13409993 X-Patchwork-Delegate: kuba@kernel.org Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 58B0315E90 for ; Thu, 5 Oct 2023 12:37:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from mail-ej1-x629.google.com (mail-ej1-x629.google.com [IPv6:2a00:1450:4864:20::629]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9E6C826A51; Thu, 5 Oct 2023 05:37:16 -0700 (PDT) Received: by mail-ej1-x629.google.com with SMTP id a640c23a62f3a-9adb9fa7200so215884166b.0; Thu, 05 Oct 2023 05:37:16 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696509432; x=1697114232; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=F6QrB9RE51dC06x5LjgJq6wybwojSHDaqDVY2rSdCIs=; b=iGxfy14qA05uTpqb9YJkv7Vxr0ty/W16zgd+iVXaK7toGF8Yv3a07AOpEe/cYV01Sq uBkElF1Q/FIYD6wd6vW1R8Nz7OevBPokb8R6cK644Vtba1JjFtAzRAtsEah9c6mrH93B iTcS1w+sbWFtygL6oJjeRA/FqOPalXGnUEJi1G8aRlQQhSD3di07z0+YcpYKO8VfByrD VDP3irpOaOybuhXQrfnm4/teKgzeb/RlQtbAwkJJng+P9s9BLduUtILQsxScD9fqAAS/ ZszPhf6e0z5JRpdoPq6WchI0138caR+XWvib6MvIfF+PsG7jC/p0eF/jqpy+9W3ALIQw w3/Q== X-Gm-Message-State: AOJu0Ywu1Ts0/9VnVu0q2fl8xqlm+lGwngddYAxSkjjTghnKiwk8AvAo Vb8EOyo3k8GhHVNjfL3SBiQ= X-Google-Smtp-Source: AGHT+IFeBpi+mOpyWz8jhMoXfirHjtAIoCHN0b4tObYTv8RAt8ztsIhfOElTM+r6sPQD4GiuGgh6Dw== X-Received: by 2002:a17:907:3f9a:b0:9ae:6648:9b53 with SMTP id hr26-20020a1709073f9a00b009ae66489b53mr1175352ejc.23.1696509431770; Thu, 05 Oct 2023 05:37:11 -0700 (PDT) Received: from localhost (fwdproxy-cln-001.fbsv.net. [2a03:2880:31ff:1::face:b00c]) by smtp.gmail.com with ESMTPSA id op13-20020a170906bced00b009a13fdc139fsm1129726ejb.183.2023.10.05.05.37.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 05 Oct 2023 05:37:11 -0700 (PDT) From: Breno Leitao To: jlbec@evilplan.org, kuba@kernel.org, davem@davemloft.net, pabeni@redhat.com, Eric Dumazet Cc: hch@lst.de, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, horms@kernel.org Subject: [PATCH net-next v2 2/3] netconsole: Attach cmdline target to dynamic target Date: Thu, 5 Oct 2023 05:36:35 -0700 Message-Id: <20231005123637.2685334-3-leitao@debian.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231005123637.2685334-1-leitao@debian.org> References: <20231005123637.2685334-1-leitao@debian.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-1.4 required=5.0 tests=BAYES_00, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: kuba@kernel.org Enable the attachment of a dynamic target to the target created during boot time. The boot-time targets are named as "cmdline\d", where "\d" is a number starting at 0. If the user creates a dynamic target named "cmdline0", it will attach to the first target created at boot time (as defined in the `netconsole=...` command line argument). `cmdline1` will attach to the second target and so forth. If there is no netconsole target created at boot time, then, the target name could be reused. Relevant design discussion: https://lore.kernel.org/all/ZRWRal5bW93px4km@gmail.com/ Suggested-by: Joel Becker Signed-off-by: Breno Leitao --- drivers/net/netconsole.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c index 7c46cf1c923e..4aa40e2e4c86 100644 --- a/drivers/net/netconsole.c +++ b/drivers/net/netconsole.c @@ -685,6 +685,23 @@ static const struct config_item_type netconsole_target_type = { .ct_owner = THIS_MODULE, }; +static struct netconsole_target *find_cmdline_target(const char *name) +{ + struct netconsole_target *nt, *ret = NULL; + unsigned long flags; + + spin_lock_irqsave(&target_list_lock, flags); + list_for_each_entry(nt, &target_list, list) { + if (!strcmp(nt->item.ci_name, name)) { + ret = nt; + break; + } + } + spin_unlock_irqrestore(&target_list_lock, flags); + + return ret; +} + /* * Group operations and type for netconsole_subsys. */ @@ -695,6 +712,17 @@ static struct config_item *make_netconsole_target(struct config_group *group, struct netconsole_target *nt; unsigned long flags; + /* Checking if a target by this name was created at boot time. If so, + * attach a configfs entry to that target. This enables dynamic + * control. + */ + if (!strncmp(name, NETCONSOLE_PARAM_TARGET_NAME, + strlen(NETCONSOLE_PARAM_TARGET_NAME))) { + nt = find_cmdline_target(name); + if (nt) + return &nt->item; + } + nt = alloc_and_init(); if (!nt) return ERR_PTR(-ENOMEM);