From patchwork Sat Apr 12 16:39:12 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andreas Gruenbacher X-Patchwork-Id: 14049059 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 AAD4B1C5F18 for ; Sat, 12 Apr 2025 16:39:30 +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=1744475972; cv=none; b=NzZvLaJ9NW/osjciVAjbhUpf57locxUlavtAjN0xDehdRtgieBesYV/s5pdz02PZaa6wjysQ5K94iijeXPJfSGxMgX6P3qXAbrAqmsNFZgaHSTHqSGy7+syFEaG6e06ATZLlmcclrowoey+QHk4BA799vRw9reUM309h1dOa0rw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744475972; c=relaxed/simple; bh=KrifTKNbtTOpZjVsriJwHelBy/tOyNLz7rJCylrYNzo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Lj17fFx5KVeOzTc95XOdazzp7jbJWXsnN90Z0dH20v3aYDZhKNlYMeGBDX4PdwWY398EiZYbK0Sl1DTo4wFCnm794qM6eVnHMBbJEZNpGXA24W8IFyswvgf2dwkYz/iLn4OYILeq3sbzuNX/8FJSEHGbmUAOb0T4bohs7kyTD8g= 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=YBLJeNkw; 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="YBLJeNkw" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1744475969; 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=as4CGAakZQuKhDm6Y+wA6IfY1weX2O0DARSrhX57YeI=; b=YBLJeNkwB+himribu+l/sVJyOhZz0Y+grHua4xPgaG6OlRtbLrqtqf7kFhbE3nFRj3Qm72 Twkum9ArTze/6Y5swXhHML/oi0niI0jqk4BIzJBtZlzBvm2RmdkrinjJB/tw1bBeYiWobH yqvcQKHyfBWAJXnVebeJKhxaXiy7mS4= 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-640-xbQKs-d4M3a2WxYTFrA6YA-1; Sat, 12 Apr 2025 12:39:28 -0400 X-MC-Unique: xbQKs-d4M3a2WxYTFrA6YA-1 X-Mimecast-MFC-AGG-ID: xbQKs-d4M3a2WxYTFrA6YA_1744475966 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (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 7D6A3180049D; Sat, 12 Apr 2025 16:39:26 +0000 (UTC) Received: from pasta.fast.eng.rdu2.dc.redhat.com (unknown [10.45.224.37]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 69ACE180174E; Sat, 12 Apr 2025 16:39:23 +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: [PATCH v3 2/2] writeback: Fix false warning in inode_to_wb() Date: Sat, 12 Apr 2025 18:39:12 +0200 Message-ID: <20250412163914.3773459-3-agruenba@redhat.com> In-Reply-To: <20250412163914.3773459-1-agruenba@redhat.com> References: <20250412163914.3773459-1-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 10.30.177.111 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 signed-off-by:Andreas somewhere. I made that change to the mm.git copy --- include/linux/backing-dev.h | 1 + 1 file changed, 1 insertion(+) diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 8e7af9a03b41..e721148c95d0 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -249,6 +249,7 @@ static inline struct bdi_writeback *inode_to_wb(const struct inode *inode) { #ifdef CONFIG_LOCKDEP WARN_ON_ONCE(debug_locks && + (inode->i_sb->s_iflags & SB_I_CGROUPWB) && (!lockdep_is_held(&inode->i_lock) && !lockdep_is_held(&inode->i_mapping->i_pages.xa_lock) && !lockdep_is_held(&inode->i_wb->list_lock)));