From patchwork Mon Apr 7 18:21:02 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andreas Gruenbacher X-Patchwork-Id: 14041495 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 A3DE9259C9E for ; Mon, 7 Apr 2025 18:21:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744050085; cv=none; b=uo6alPFcu0WYmE3Y2peqWydB/jFtwssi7nGPfkYZV6pw721wTBuN8VT/zlDXpfuHRmaOb5uDgZR6dFh750sJblItmNpVDve8e2J+MRN/iQgYIxkC3RHVt5fyShpTv2qtQayZpM4rbI72euC1TfMN0UJjbRS4i5GiRc71nO67Zrw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744050085; c=relaxed/simple; bh=sBuyu8GDFSBAh8ocfuIg/uvXdPS+I0GpOEiqMXd2lww=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UwdivalyF+KieEuO0aEXONm7dibPwcGOP/X0ibpQuJfAAbtqFYsdVX9znyGirLKDctJreB3FuxYZd4mmJL1H8ErRaPYYxjupYaw0Ct/IJB/3sCxRvc4mjXNq/u/Oyg/1Ck108nfZp2+CX6Rjsifw1tfSk0QEmWeJ3HuTIUxn+ZM= 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=ARTtZ2RD; arc=none smtp.client-ip=170.10.133.124 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="ARTtZ2RD" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1744050082; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=r207ou57TRn4Q0BVpY2sMaqzJuM7STz+41u9bkzpKR4=; b=ARTtZ2RDpvXQeWIE77O1yzU0JJm5dD8OXCeGGTaKmCMNkNlr+RVhZZoCx9HfDiObh4+QDD +JyZ2H2tMa7WR7Hrl2nb2Aat3px4b29y4L9gnF8yB62RKOe9AowVeG74RuxMeNIhPV5t6U XlNv3nmfcLfDobKF+R2Ap97c//BSKGo= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-662-K0TaAE15OlaiLMNeZtQo6Q-1; Mon, 07 Apr 2025 14:21:18 -0400 X-MC-Unique: K0TaAE15OlaiLMNeZtQo6Q-1 X-Mimecast-MFC-AGG-ID: K0TaAE15OlaiLMNeZtQo6Q_1744050076 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7899318001F6; Mon, 7 Apr 2025 18:21:16 +0000 (UTC) Received: from pasta.fast.eng.rdu2.dc.redhat.com (unknown [10.45.224.15]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 352CB1828AA8; Mon, 7 Apr 2025 18:21:12 +0000 (UTC) From: Andreas Gruenbacher To: cgroups@vger.kernel.org Cc: Jan Kara , Tetsuo Handa , Rafael Aquini , gfs2@lists.linux.dev, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Andreas Gruenbacher Subject: [RFC 2/2] writeback: Fix false warning in inode_to_wb() Date: Mon, 7 Apr 2025 20:21:02 +0200 Message-ID: <20250407182104.716631-3-agruenba@redhat.com> In-Reply-To: <20250407182104.716631-1-agruenba@redhat.com> References: <20250407182104.716631-1-agruenba@redhat.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 From: Jan Kara inode_to_wb() is used also for filesystems that don't support cgroup writeback. For these filesystems inode->i_wb is stable during the lifetime of the inode (it points to bdi->wb) and there's no need to hold locks protecting the inode->i_wb dereference. Improve the warning in inode_to_wb() to not trigger for these filesystems. Signed-off-by: Jan Kara Reviewed-by: Andreas Gruenbacher --- include/linux/backing-dev.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 8e7af9a03b41..4069a027582f 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -245,10 +245,11 @@ wb_get_create_current(struct backing_dev_info *bdi, gfp_t gfp) * holding either @inode->i_lock, the i_pages lock, or the * associated wb's list_lock. */ -static inline struct bdi_writeback *inode_to_wb(const struct inode *inode) +static inline struct bdi_writeback *inode_to_wb(struct inode *inode) { #ifdef CONFIG_LOCKDEP WARN_ON_ONCE(debug_locks && + inode_cgwb_enabled(inode) && (!lockdep_is_held(&inode->i_lock) && !lockdep_is_held(&inode->i_mapping->i_pages.xa_lock) && !lockdep_is_held(&inode->i_wb->list_lock)));