From patchwork Wed Oct 31 16:47:18 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Shinkevich X-Patchwork-Id: 10662997 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7C8DF13BF for ; Wed, 31 Oct 2018 17:13:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6B0672851B for ; Wed, 31 Oct 2018 17:13:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5E8972859F; Wed, 31 Oct 2018 17:13:35 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 16D052851B for ; Wed, 31 Oct 2018 17:13:34 +0000 (UTC) Received: from localhost ([::1]:60904 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gHu3i-00007u-2z for patchwork-qemu-devel@patchwork.kernel.org; Wed, 31 Oct 2018 13:13:34 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53952) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gHter-0006j2-7e for qemu-devel@nongnu.org; Wed, 31 Oct 2018 12:47:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gHtem-0004dU-Vn for qemu-devel@nongnu.org; Wed, 31 Oct 2018 12:47:53 -0400 Received: from relay.sw.ru ([185.231.240.75]:55770) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gHtem-0004cL-NF; Wed, 31 Oct 2018 12:47:48 -0400 Received: from [172.16.25.136] (helo=localhost.sw.ru) by relay.sw.ru with esmtp (Exim 4.90_1) (envelope-from ) id 1gHteQ-0005jc-Ec; Wed, 31 Oct 2018 19:47:26 +0300 From: Andrey Shinkevich To: qemu-devel@nongnu.org, qemu-block@nongnu.org Date: Wed, 31 Oct 2018 19:47:18 +0300 Message-Id: <1541004440-182262-1-git-send-email-andrey.shinkevich@virtuozzo.com> X-Mailer: git-send-email 1.8.3.1 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 185.231.240.75 X-Mailman-Approved-At: Wed, 31 Oct 2018 13:12:12 -0400 Subject: [Qemu-devel] [PATCH 0/2] Discrad blocks during block-stream operation X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, vsementsov@virtuozzo.com, jcody@redhat.com, armbru@redhat.com, dgilbert@redhat.com, andrey.shinkevich@virtuozzo.com, den@openvz.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Hello everyone! The given feature discards blocks with copy-on-read operation while the streaming process runs. Adding the 'discard' argument to the QMP block-stream command allows dropping a block in the backing chain after it has been copied to the active layer. That will elude the block duplication in the intermediate backing file. It saves the disk space while external snapshots are being merged. The method involves the filter insertion above the active layer to allow write operation in the backing chain. The method is similar to that in the 'commit active' command (mirror.c). Andrey Shinkevich (2): The discard flag for block stream operation Discard blocks while copy-on-read block/stream.c | 402 ++++++++++++++++++++++++++++++++++++++++++++-- blockdev.c | 8 +- hmp-commands.hx | 4 +- hmp.c | 4 +- include/block/block_int.h | 2 +- qapi/block-core.json | 5 +- 6 files changed, 407 insertions(+), 18 deletions(-)