From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52264) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eFkIb-0000Rx-3U for qemu-devel@nongnu.org; Fri, 17 Nov 2017 12:19:29 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eFkIa-0002ze-Bd for qemu-devel@nongnu.org; Fri, 17 Nov 2017 12:19:29 -0500 Date: Fri, 17 Nov 2017 18:19:20 +0100 From: Kevin Wolf Message-ID: <20171117171920.GI4795@localhost.localdomain> References: <20171117164747.11525-1-eblake@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171117164747.11525-1-eblake@redhat.com> Subject: Re: [Qemu-devel] [PATCH for-2.11] qcow2: fix image corruption on commit with persistent snapshot List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake Cc: qemu-devel@nongnu.org, qemu-block@nongnu.org, vsementsov@virtuozzo.com, Max Reitz Am 17.11.2017 um 17:47 hat Eric Blake geschrieben: > If an image contains persistent snapshots, we cannot use the > fast path of bdrv_make_empty() to clear the image during > qemu-img commit, because that will lose the clusters related > to the bitmaps. > > Also leave a comment in qcow2_read_extensions to remind future > feature additions to think about fast-path removal, since we > just barely fixed the same bug for LUKS encryption. > > It's a pain that qemu-img has not yet been taught to manipulate, > or even at a very minimum display, information about persistent > bitmaps; instead, we have to use QMP commands. It's also a > pain that only qeury-block and x-debug-block-dirty-bitmap-sha256 s/qeury/query/ > will allow bitmap introspection; but the former requires the > node to be hooked to a block device, and the latter is experimental. > > Signed-off-by: Eric Blake Thanks, fixed the typo above and applied to the block branch. Kevin