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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable 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 4B18DC3F68F for ; Thu, 12 Dec 2019 09:54:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2C6C4214AF for ; Thu, 12 Dec 2019 09:54:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728431AbfLLJye (ORCPT ); Thu, 12 Dec 2019 04:54:34 -0500 Received: from verein.lst.de ([213.95.11.211]:32911 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728282AbfLLJye (ORCPT ); Thu, 12 Dec 2019 04:54:34 -0500 Received: by verein.lst.de (Postfix, from userid 2407) id 59FF468B05; Thu, 12 Dec 2019 10:54:31 +0100 (CET) Date: Thu, 12 Dec 2019 10:54:31 +0100 From: Christoph Hellwig To: Balbir Singh Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, axboe@kernel.dk, mst@redhat.com, jejb@linux.ibm.com, hch@lst.de, linux-nvme@lists.infradead.org, Someswarudu Sangaraju Subject: Re: [RFC PATCH] block/genhd: Notify udev about capacity change Message-ID: <20191212095431.GA3720@lst.de> References: <20191210030131.4198-1-sblbir@amazon.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191210030131.4198-1-sblbir@amazon.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 10, 2019 at 03:01:31AM +0000, Balbir Singh wrote: > Allow block/genhd to notify user space (via udev) about disk size changes > using a new helper disk_set_capacity(), which is a wrapper on top > of set_capacity(). disk_set_capacity() will only notify via udev if > the current capacity or the target capacity is not zero. > > disk_set_capacity() is not enabled for all devices, just virtio block, > xen-blockfront, nvme and sd. Owners of other block disk devices can > easily move over by changing set_capacity() to disk_set_capacity() > > Background: > > As a part of a patch to allow sending the RESIZE event on disk capacity > change, Christoph (hch@lst.de) requested that the patch be made generic > and the hacks for virtio block and xen block devices be removed and > merged via a generic helper. > > Testing: > 1. I did some basic testing with an NVME device, by resizing it in > the backend and ensured that udevd received the event. > > Suggested-by: Christoph Hellwig > Signed-off-by: Balbir Singh > Signed-off-by: Someswarudu Sangaraju > --- > block/genhd.c | 19 +++++++++++++++++++ > drivers/block/virtio_blk.c | 4 +--- > drivers/block/xen-blkfront.c | 5 +---- > drivers/nvme/host/core.c | 2 +- > drivers/scsi/sd.c | 2 +- > include/linux/genhd.h | 1 + > 6 files changed, 24 insertions(+), 9 deletions(-) > > diff --git a/block/genhd.c b/block/genhd.c > index ff6268970ddc..94faec98607b 100644 > --- a/block/genhd.c > +++ b/block/genhd.c > @@ -46,6 +46,25 @@ static void disk_add_events(struct gendisk *disk); > static void disk_del_events(struct gendisk *disk); > static void disk_release_events(struct gendisk *disk); > > +/* > + * Set disk capacity and notify if the size is not currently > + * zero and will not be set to zero Nit: Use up all the 80 chars per line. Also maybe turn this into a kerneldoc comment. I think you also want to mention the notification as well. > +EXPORT_SYMBOL_GPL(disk_set_capacity); > + > + > void part_inc_in_flight(struct request_queue *q, struct hd_struct *part, int rw) No need for the double empty line. > { > if (queue_is_mq(q)) > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > index 7ffd719d89de..869cd3c31529 100644 > --- a/drivers/block/virtio_blk.c > +++ b/drivers/block/virtio_blk.c And you probably want to turn this into a series with patch 1 adding the infrastructure, and then one patch per driver switched over.