From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 E68BF22B8D2 for ; Fri, 21 Mar 2025 16:31:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742574685; cv=none; b=LyiMkl2AV/yb6SL6hZ4NKqV27twzRhb+ZBkNmJ0Sx1FdUvrTtcLyDz1Zy6VUDhGmkK0axaoUcQdemEgvo8zLUQubpTb11v22rThx65PQoO8f3Jx+pmBnOLAygOwkp3hLB7JmGA3rh2XYsIH6f8N887gNe1K0/irABbPlngt+AsQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742574685; c=relaxed/simple; bh=TTuTJrh7x9Bt4TSiLnCijMGPZZ4HvDdlyCy/gTUUm5s=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=dJoFtDkzsPz9PGafjG/0CZFg3rxtwo6V5Sd2vwDs0y8JnecidpEmRFqo0sDWSYCOV59fmcivvnFYqDwZIQrI2FV+19ro7xz1EawfEPonk6ozbfujZkkvYtLw2Bbk+olY+daCp14iHu5zgqOs5LkKG5Av+K56v1AdBQejyDx5Exw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=FfP7a2kB; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="FfP7a2kB" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1742574682; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rs+RwcS9h+V2ikhjyQECAnVV51IDsPepgkZ5ImH1XsI=; b=FfP7a2kBYhrvq/VhEVR6vO1LcX5Amfgf9YWa4O4emOoAyiE0vtSLK/oU3fJkQq/ZGdM8Bz Y7rBqdYsUD5YgESj8Q4YDhFXU1o0otcMXY4hgsdZge5suTQsVbYVkMGLoc3wJRKPoztVvY XScpJlhu6GgK20uLDInCCDvBn5tCCwU= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-149--T2C3q6jOmyk92l9EplpBA-1; Fri, 21 Mar 2025 12:31:21 -0400 X-MC-Unique: -T2C3q6jOmyk92l9EplpBA-1 X-Mimecast-MFC-AGG-ID: -T2C3q6jOmyk92l9EplpBA_1742574680 Received: by mail-wr1-f69.google.com with SMTP id ffacd0b85a97d-3912d9848a7so1660645f8f.0 for ; Fri, 21 Mar 2025 09:31:21 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1742574680; x=1743179480; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=rs+RwcS9h+V2ikhjyQECAnVV51IDsPepgkZ5ImH1XsI=; b=togEnvl3QrCOv+/BAhirKE7gCwAT2FAZXsX3f5sv3Cfi+hnTWp8EjEVusEIjmSAYFL JiomWWdxIAMAc23QjD4w+BiUWqoSSxdBJJ8FHFhkkVm2OFnwhHwYUdivQJ8erEIxyGyd TiIMTqR+Oa8M0G3gfWurxs/wt5jzl2+YMA90fwAYIUrS6WHuBsTPngF6Z1UOls/bbc8a 9Ri/1X0rFPG/wVnS8K5G1iAE/c5wsS/AD3AuMdo9AqbiKeKITucYHpx2AcaSbRROrN8H fBV3Il1vPwOmMzugw+mek7gqeXz0mvor13mVBsE8z1tcIqpLoA/vt2AfbyTIEuiBqjA9 n3pA== X-Gm-Message-State: AOJu0Yx5MqqYIHSLfFfFicwRA0clwxKU6J2wD/Znh+AvUhWRqtY9xhG5 NwYp0BrjggZGdf4eJ5vSZgNVSgTYs9QIcDv2eESZGldYxFfLTg0uGPyrUdsgsK3ilzJJkYmt64u cL+GYQAtHQSHnxhGSDrKdBIVPBN5RqJk+3KSCHSY2+0oTtRznnHMAyg== X-Gm-Gg: ASbGnctTYLlLvxmofLr9VRAYaWDY0li1qEzAsceSAJVQu4s/lEpy4TvqcaduvagaqCa khaA/zoJFAD1HpejubGslrVMCW7DqO6hVXADmIurJAariz2QRvjAfs4TIDDbn2DFY6mxKjuhQON KaWsIPLWgQOtv4wBPxqDxR1VBQK8MXQpVnSaVlPP2U2rx0DtfA3RMgGNffnsnSSjvl0GpLspHhO 0yjPvkc6UiRbULH4YbBEK6yhmHAVoRs4Do5P3I2QJRkkxPPbJxqp4vNgS48o+Asd+b31yhSKdEx uJOylX97pOlTz0ZPupDXPs/9EuVYQ3NAggaTWc5QrZY8dA== X-Received: by 2002:a5d:64ce:0:b0:38d:dc03:a3d6 with SMTP id ffacd0b85a97d-399795567f7mr7617675f8f.4.1742574680074; Fri, 21 Mar 2025 09:31:20 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHd4IZz5KXdcrX0+aF/TgGlXF2jzu4TiS7+n1daZwv+t8eYjf13W84OlRjl+h4tIxUwcH3iXA== X-Received: by 2002:a5d:64ce:0:b0:38d:dc03:a3d6 with SMTP id ffacd0b85a97d-399795567f7mr7617598f8f.4.1742574679564; Fri, 21 Mar 2025 09:31:19 -0700 (PDT) Received: from [192.168.88.253] (146-241-77-210.dyn.eolo.it. [146.241.77.210]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3997f9a3f6bsm2830317f8f.39.2025.03.21.09.31.17 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 21 Mar 2025 09:31:19 -0700 (PDT) Message-ID: Date: Fri, 21 Mar 2025 17:31:17 +0100 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net-next v3 1/7] net: ethtool: netlink: Allow per-netdevice DUMP operations To: Maxime Chevallier , davem@davemloft.net, Andrew Lunn , Jakub Kicinski , Eric Dumazet , Heiner Kallweit Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, thomas.petazzoni@bootlin.com, linux-arm-kernel@lists.infradead.org, Christophe Leroy , Herve Codina , Florian Fainelli , Russell King , Vladimir Oltean , =?UTF-8?Q?K=C3=B6ry_Maincent?= , Oleksij Rempel , Simon Horman , Romain Gantois , Piergiorgio Beruto References: <20250313182647.250007-1-maxime.chevallier@bootlin.com> <20250313182647.250007-2-maxime.chevallier@bootlin.com> Content-Language: en-US From: Paolo Abeni In-Reply-To: <20250313182647.250007-2-maxime.chevallier@bootlin.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 3/13/25 7:26 PM, Maxime Chevallier wrote: > We have a number of netlink commands in the ethnl family that may have > multiple objects to dump even for a single net_device, including : > > - PLCA, PSE-PD, phy: one message per PHY device > - tsinfo: one message per timestamp source (netdev + phys) > - rss: One per RSS context > > To get this behaviour, these netlink commands need to roll a custom > ->dumpit(). > > To prepare making per-netdev DUMP more generic in ethnl, introduce a > member in the ethnl ops to indicate if a given command may allow > pernetdev DUMPs (also referred to as filtered DUMPs). > > Signed-off-by: Maxime Chevallier > --- > net/ethtool/netlink.c | 45 +++++++++++++++++++++++++++++-------------- > net/ethtool/netlink.h | 2 ++ > 2 files changed, 33 insertions(+), 14 deletions(-) > > diff --git a/net/ethtool/netlink.c b/net/ethtool/netlink.c > index a163d40c6431..7adede5e4ff1 100644 > --- a/net/ethtool/netlink.c > +++ b/net/ethtool/netlink.c > @@ -587,21 +587,38 @@ static int ethnl_default_dumpit(struct sk_buff *skb, > int ret = 0; > > rcu_read_lock(); Maintain the RCU read lock here is IMHO confusing... > - for_each_netdev_dump(net, dev, ctx->pos_ifindex) { > - dev_hold(dev); > + if (ctx->req_info->dev) { > + dev = ctx->req_info->dev; .. as this is refcounted. I suggest to move the rcu_read_lock inside the if. > rcu_read_unlock(); > + /* Filtered DUMP request targeted to a single netdev. We already > + * hold a ref to the netdev from ->start() > + */ > + ret = ethnl_default_dump_one(skb, dev, ctx, > + genl_info_dump(cb)); > + rcu_read_lock(); > + netdev_put(ctx->req_info->dev, &ctx->req_info->dev_tracker); > > - ret = ethnl_default_dump_one(skb, dev, ctx, genl_info_dump(cb)); > + if (ret < 0 && ret != -EOPNOTSUPP && likely(skb->len)) > + ret = skb->len; > > - rcu_read_lock(); > - dev_put(dev); > + } else { > + for_each_netdev_dump(net, dev, ctx->pos_ifindex) { > + dev_hold(dev); > + rcu_read_unlock(); > + > + ret = ethnl_default_dump_one(skb, dev, ctx, > + genl_info_dump(cb)); > + > + rcu_read_lock(); > + dev_put(dev); > > - if (ret < 0 && ret != -EOPNOTSUPP) { > - if (likely(skb->len)) > - ret = skb->len; > - break; > + if (ret < 0 && ret != -EOPNOTSUPP) { > + if (likely(skb->len)) > + ret = skb->len; IMHO a bit too many levels of indentation. It's possibly better to move this code in a separate helper. Thanks, Paolo