From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6714DC433E0 for ; Wed, 12 Aug 2020 17:50:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 52BD72076C for ; Wed, 12 Aug 2020 17:50:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726477AbgHLRuR (ORCPT ); Wed, 12 Aug 2020 13:50:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49200 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726013AbgHLRuR (ORCPT ); Wed, 12 Aug 2020 13:50:17 -0400 Received: from ms.lwn.net (ms.lwn.net [IPv6:2600:3c01:e000:3a1::42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 574CCC061383; Wed, 12 Aug 2020 10:50:17 -0700 (PDT) Received: from lwn.net (localhost [127.0.0.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ms.lwn.net (Postfix) with ESMTPSA id 988AD221; Wed, 12 Aug 2020 17:50:12 +0000 (UTC) Date: Wed, 12 Aug 2020 11:50:11 -0600 From: Jonathan Corbet To: Leah Rumancik Cc: bpf@vger.kernel.org, linux-block@vger.kernel.org, orbekk@google.com, harshads@google.com, jasiu@google.com, saranyamohan@google.com, tytso@google.com, bvanassche@google.com Subject: Re: [RFC PATCH 3/4] bpf: add eBPF IO filter documentation Message-ID: <20200812115011.337c0099@lwn.net> In-Reply-To: <20200812163305.545447-4-leah.rumancik@gmail.com> References: <20200812163305.545447-1-leah.rumancik@gmail.com> <20200812163305.545447-4-leah.rumancik@gmail.com> Organization: LWN.net MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Wed, 12 Aug 2020 16:33:04 +0000 Leah Rumancik wrote: Thanks for documenting this stuff, but... > +====================== > +IO Filtering with eBPF > +====================== > + > +Bio requests can be filtered with the eBPF IO filter program type (BPF_PROG_TYPE_IO_FILTER). To use this program type, the kernel must be compiled with CONFIG_BPF_IO_FILTER. > + > +Attachment > +========== > + > +IO filter programs can be attached to disks using the BPF_BIO_SUBMIT attach type. Up to 64 filter programs can be attached to a single disk. References to the attached programs are stored in the gendisk struct as a bpf_prog_array. Please wrap your text to a reasonable column width just like with any other kernel file. Thanks, jon