From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kay Sievers Date: Mon, 25 Feb 2013 23:04:15 +0000 Subject: Re: [PATCH] virtio-blk: emit udev event when device is resized Message-Id: List-Id: References: <1361473348-7660-1-git-send-email-milos.vyletel@sde.cz> <87y5ehfczy.fsf@rustcorp.com.au> <20130225221238.GA10575@kroah.com> <20130225224339.GA19153@kroah.com> In-Reply-To: <20130225224339.GA19153@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Greg KH Cc: Rusty Russell , Milos Vyletel , linux-kernel@vger.kernel.org, linux-hotplug@vger.kernel.org, virtualization@lists.linux-foundation.org, mst@redhat.com On Mon, Feb 25, 2013 at 11:43 PM, Greg KH wrote: > On Mon, Feb 25, 2013 at 11:39:52PM +0100, Kay Sievers wrote: >> On Mon, Feb 25, 2013 at 11:12 PM, Greg KH wrote: >> >> > Hm, I thought we were frowning apon running binaries from udev rules >> > these days, especially ones that might have big consequences (like >> > resizing a disk image) like this. >> > >> > Kay, am I right? >> >> We removed most of them from the default setups, yes. But there is >> nothing wrong if people want to ship that in some package or as custom >> rules. >> >> It looks fine to me, we would just not add such things to the default >> set of of rules these days. >> >> > We already emit KOBJECT_CHANGE events when block devices change, from >> > within the block core code. Why is the patch below needed instead of >> > using these events that are already generated? How are virtio block >> > devices special? >> >> I think we only do that for dm and md and a couple of special cases >> like loop and read-only settings. > > What about when we repartition a block device? I've seen the events > happen then. Right, from the common block code we send events for removable media changes like cdroms, sd cards, when a device is switched to read-only, and when we re-scan a partition table like on re-partitioning. Most of the other events are block subsystem-specific like this one. For things like device-mapper they are used pretty heavily. > Anyway, if you are ok with this, no objection from my side then Rusty. Looks fine to me, it should not do any harm if there are not heavy programs hooked up -- which is nothing the kernel could fix if people do that. :) Kay