From patchwork Wed Feb 7 14:26:24 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Dumazet X-Patchwork-Id: 13548584 X-Patchwork-Delegate: kuba@kernel.org Received: from mail-yb1-f202.google.com (mail-yb1-f202.google.com [209.85.219.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6A7837E567 for ; Wed, 7 Feb 2024 14:26:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707316009; cv=none; b=QZ8msfTMt5KxOVBHLUr2GjElEQ7Yyzg2EIdgmxLhWEAJ7i/EQhn5PR3xSuC96NM5rmpfHKxSkkkhzNGhoZXym+B58pCSrdzI6qR1+nEh9gJvZ3SGbNBKUYWiOG+CFMC0dee7HnEuIQ+ReDZT9g3PUEPgeF50CuoDpKkgfwQJ9RQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707316009; c=relaxed/simple; bh=25ClL7WoqH767H4g7uyDndpTdLFT1mSh66swzGoqCYQ=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=SvMex+WuM/IoQmeKvxEv56CrHW0V0LLNwLyeeRo1/0ER4qR+Zcj37d/MSG8nGq6kHW3HtVamz9RhGPChi/EQ1HbpIqpwFVGa4FwvNK16j5K5L/s3Atiw8QMHOuOWLnJymwzkJBdTtfX/SXi8KPRK9RNPaDo7UhNkWQGyIki91d0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=lsxmVct2; arc=none smtp.client-ip=209.85.219.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="lsxmVct2" Received: by mail-yb1-f202.google.com with SMTP id 3f1490d57ef6-dc6df2b2d1aso854745276.1 for ; Wed, 07 Feb 2024 06:26:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1707316007; x=1707920807; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=W0IAsWsB1rkkDQSBmIH07o3Uzv0VcNGVc215KBSmS+E=; b=lsxmVct2mqJVDJbIcTwfNqyme+DNirGycn4bweXFuDMWx9bp2/BO3zEiGs+K5OO1op ZXYe8wigYxY5g09qxx8D2NCvh//jgXvAR17NFb2th+zEypzapNkE1w9e8XCy4CqicEP0 SknIcRHKctRbmGWOxfEUL7wNlj6FniNxlbMf260ynpecNgPUh3AlpBW+ps8diLNpjjN5 nfQTdtJAchESnbTKManpg+TaPKLhrHrMg2r2g7+KE0QUzSeZaCVRDKk1bxmzHbrsgsP/ vw2n3vqMnXYJhf188VQf1UPKPPEtXFP+ulBglGAW/Ubxjmp0q2UxOCfeFYg8dBGHaxpd OTyw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1707316007; x=1707920807; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=W0IAsWsB1rkkDQSBmIH07o3Uzv0VcNGVc215KBSmS+E=; b=qq7vOhiewPGk8Hv8RBbGkpAIvSOgg6P1JGKkS9hW9FJGFY0mUBpAsOhKEPdpOGxOAJ 2qcV03SMVhagS7dyz9+y42CQnBgeWhIoXqstvdNmov4Q39a3ldzideggF6jSxVeFqXqB aCx7euiKXy15uVYzX8EHXz6wybqMW7Sr2Ea6B54Mwh720v5ThgS46L8WK3i6BbLJ0Pkf WlJkkPWb+LHSqvkU0AM04rC7lg/J2Pch11kggIm/FWP5wXphKOA20tbCSt4FR9APW80m bTcLBGdMpDHrszFRamS78z96Dtd6dVueDzk1N9d6vX/0EU3fxBUdMFBZxDf+Oy7A5nbe hDfw== X-Gm-Message-State: AOJu0YyFvk6c3rb40E8vT+zVBugCDQAMAQKvnKCo/8dNk6TMXEAmRIyN /WyPIgo7luKxc+ThjAXuAnghukUmOa7lIfvDSoPSQxvHFKaeoBETCEbs2KGwUNPIovH23m1DiT8 DDcjYAb1+GA== X-Google-Smtp-Source: AGHT+IEfU9i8Dic/6/T5TTaK5E65VIFzt/ENU/4yZzR634OYNlGv6k4n1lH1pggLE+kEaEjeqizG9bPCNusv4w== X-Received: from edumazet1.c.googlers.com ([fda3:e722:ac3:cc00:2b:7d90:c0a8:395a]) (user=edumazet job=sendgmr) by 2002:a05:6902:178f:b0:dc1:f6f0:1708 with SMTP id ca15-20020a056902178f00b00dc1f6f01708mr178870ybb.7.1707316007420; Wed, 07 Feb 2024 06:26:47 -0800 (PST) Date: Wed, 7 Feb 2024 14:26:24 +0000 In-Reply-To: <20240207142629.3456570-1-edumazet@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240207142629.3456570-1-edumazet@google.com> X-Mailer: git-send-email 2.43.0.594.gd9cf4e227d-goog Message-ID: <20240207142629.3456570-9-edumazet@google.com> Subject: [PATCH net-next 08/13] net-sysfs: convert netstat_show() to RCU From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com, Eric Dumazet X-Patchwork-Delegate: kuba@kernel.org dev_get_stats() can be called from RCU, there is no need to acquire dev_base_lock. Change dev_isalive() comment to reflect we no longer use dev_base_lock from net/core/net-sysfs.c Signed-off-by: Eric Dumazet --- net/core/net-sysfs.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index c5d164b8c6bfb53793f8422063c6281d6339b36e..946caefdd9599f631a73487e950305c978f8bc66 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -34,7 +34,7 @@ static const char fmt_dec[] = "%d\n"; static const char fmt_ulong[] = "%lu\n"; static const char fmt_u64[] = "%llu\n"; -/* Caller holds RTNL, RCU or dev_base_lock */ +/* Caller holds RTNL or RCU */ static inline int dev_isalive(const struct net_device *dev) { return READ_ONCE(dev->reg_state) <= NETREG_REGISTERED; @@ -685,14 +685,14 @@ static ssize_t netstat_show(const struct device *d, WARN_ON(offset > sizeof(struct rtnl_link_stats64) || offset % sizeof(u64) != 0); - read_lock(&dev_base_lock); + rcu_read_lock(); if (dev_isalive(dev)) { struct rtnl_link_stats64 temp; const struct rtnl_link_stats64 *stats = dev_get_stats(dev, &temp); ret = sysfs_emit(buf, fmt_u64, *(u64 *)(((u8 *)stats) + offset)); } - read_unlock(&dev_base_lock); + rcu_read_unlock(); return ret; }