From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39098) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eCOtO-0007iD-9g for qemu-devel@nongnu.org; Wed, 08 Nov 2017 06:51:39 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eCOtN-0004Ee-Ie for qemu-devel@nongnu.org; Wed, 08 Nov 2017 06:51:38 -0500 Date: Wed, 8 Nov 2017 12:51:27 +0100 From: Kevin Wolf Message-ID: <20171108115127.GC30890@localhost.localdomain> References: <20171107172638.29942-1-kwolf@redhat.com> <20171107173920.GK3213@redhat.com> <357d61df-9bad-dc5a-1878-2fce4b2a93cc@redhat.com> <20171108104907.GN12670@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171108104907.GN12670@redhat.com> Subject: Re: [Qemu-devel] [PATCH] block: Deprecate bdrv_set_read_only() and users List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Daniel P. Berrange" Cc: Paolo Bonzini , mreitz@redhat.com, qemu-devel@nongnu.org, qemu-block@nongnu.org, armbru@redhat.com Am 08.11.2017 um 11:49 hat Daniel P. Berrange geschrieben: > On Wed, Nov 08, 2017 at 11:44:01AM +0100, Paolo Bonzini wrote: > > On 07/11/2017 18:39, Daniel P. Berrange wrote: > > > On Tue, Nov 07, 2017 at 06:26:38PM +0100, Kevin Wolf wrote: > > >> bdrv_set_read_only() is used by some block drivers to override the > > >> read-only option given by the user. This is not how read-only images > > >> generally work in QEMU: Instead of second guessing what the user really > > >> meant (which currently includes making an image read-only even if the > > >> user didn't only use the default, but explicitly said read-only=off), we > > >> should error out if we can't provide what the user requested. > > >> > > >> This adds deprecation warnings to all callers of bdrv_set_read_only() so > > >> that the behaviour can be corrected after the usual deprecation period. > > > > > > All deprecations should be listed in "Deprecated features" appendix > > > in qemu-doc.texi. This probably fits in the 'system emulator command > > > line arguments' section, even though its talking about the need for > > > the user to add something extra, rather than deleting something they > > > currently use. > > > > I am not sure this counts as deprecation, but it should go in the > > release notes as "future incompatible changes", and that section > > probably should go in qemu-doc.texi itself. > > Yeah, adding a "Incompatible changes" appendix to the qemu-doc.texi > would be useful, listing the planned change, and when it is actually > made. That way apps adding support for a feature have an indication > of any incompatiblities they might need to care about. You mean a section containing future incompatible changes as well as already implemented incompatible changes? What would we do with the existing "Deprecated features" section? Would it become a subsection of "Incompatible changes"? Or would we just rename it and the subsections would stay on the same level and get "deprecated" added to their title? Or a completely different structure? I'm okay with adding a little documentation in this patch if I know what it should look like, but if it turns into a major overhaul of the documentation on incompatible changes, it's probably out of scope for this patch. Kevin