From patchwork Fri Sep 20 16:20:55 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 11154707 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AC15376 for ; Fri, 20 Sep 2019 16:39:17 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8DBA6208C3 for ; Fri, 20 Sep 2019 16:39:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8DBA6208C3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:33628 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iBLwC-0006TE-65 for patchwork-qemu-devel@patchwork.kernel.org; Fri, 20 Sep 2019 12:39:16 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:52898) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iBLel-0007fg-PZ for qemu-devel@nongnu.org; Fri, 20 Sep 2019 12:21:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iBLej-0008Cn-MF for qemu-devel@nongnu.org; Fri, 20 Sep 2019 12:21:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59744) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iBLed-00089B-P6; Fri, 20 Sep 2019 12:21:09 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id CCB823082E24; Fri, 20 Sep 2019 16:21:05 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-117-81.ams2.redhat.com [10.36.117.81]) by smtp.corp.redhat.com (Postfix) with ESMTP id C6003646A1; Fri, 20 Sep 2019 16:21:04 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Subject: [PULL 1/4] block/snapshot: Restrict set of snapshot nodes Date: Fri, 20 Sep 2019 18:20:55 +0200 Message-Id: <20190920162058.29743-2-kwolf@redhat.com> In-Reply-To: <20190920162058.29743-1-kwolf@redhat.com> References: <20190920162058.29743-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.46]); Fri, 20 Sep 2019 16:21:05 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, peter.maydell@linaro.org, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" Nodes involved in internal snapshots were those that were returned by bdrv_next(), inserted and not read-only. bdrv_next() in turn returns all nodes that are either the root node of a BlockBackend or monitor-owned nodes. With the typical -drive use, this worked well enough. However, in the typical -blockdev case, the user defines one node per option, making all nodes monitor-owned nodes. This includes protocol nodes etc. which often are not snapshottable, so "savevm" only returns an error. Change the conditions so that internal snapshot still include all nodes that have a BlockBackend attached (we definitely want to snapshot anything attached to a guest device and probably also the built-in NBD server; snapshotting block job BlockBackends is more of an accident, but a preexisting one), but other monitor-owned nodes are only included if they have no parents. This makes internal snapshots usable again with typical -blockdev configurations. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf Reviewed-by: Eric Blake Reviewed-by: Peter Krempa Tested-by: Peter Krempa --- block/snapshot.c | 26 +++++++++++++++++++------- 1 file changed, 19 insertions(+), 7 deletions(-) diff --git a/block/snapshot.c b/block/snapshot.c index f2f48f926a..8081616ae9 100644 --- a/block/snapshot.c +++ b/block/snapshot.c @@ -31,6 +31,7 @@ #include "qapi/qmp/qerror.h" #include "qapi/qmp/qstring.h" #include "qemu/option.h" +#include "sysemu/block-backend.h" QemuOptsList internal_snapshot_opts = { .name = "snapshot", @@ -384,6 +385,16 @@ int bdrv_snapshot_load_tmp_by_id_or_name(BlockDriverState *bs, return ret; } +static bool bdrv_all_snapshots_includes_bs(BlockDriverState *bs) +{ + if (!bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) { + return false; + } + + /* Include all nodes that are either in use by a BlockBackend, or that + * aren't attached to any node, but owned by the monitor. */ + return bdrv_has_blk(bs) || QLIST_EMPTY(&bs->parents); +} /* Group operations. All block drivers are involved. * These functions will properly handle dataplane (take aio_context_acquire @@ -399,7 +410,7 @@ bool bdrv_all_can_snapshot(BlockDriverState **first_bad_bs) AioContext *ctx = bdrv_get_aio_context(bs); aio_context_acquire(ctx); - if (bdrv_is_inserted(bs) && !bdrv_is_read_only(bs)) { + if (bdrv_all_snapshots_includes_bs(bs)) { ok = bdrv_can_snapshot(bs); } aio_context_release(ctx); @@ -426,8 +437,9 @@ int bdrv_all_delete_snapshot(const char *name, BlockDriverState **first_bad_bs, AioContext *ctx = bdrv_get_aio_context(bs); aio_context_acquire(ctx); - if (bdrv_can_snapshot(bs) && - bdrv_snapshot_find(bs, snapshot, name) >= 0) { + if (bdrv_all_snapshots_includes_bs(bs) && + bdrv_snapshot_find(bs, snapshot, name) >= 0) + { ret = bdrv_snapshot_delete(bs, snapshot->id_str, snapshot->name, err); } @@ -455,7 +467,7 @@ int bdrv_all_goto_snapshot(const char *name, BlockDriverState **first_bad_bs, AioContext *ctx = bdrv_get_aio_context(bs); aio_context_acquire(ctx); - if (bdrv_can_snapshot(bs)) { + if (bdrv_all_snapshots_includes_bs(bs)) { ret = bdrv_snapshot_goto(bs, name, errp); } aio_context_release(ctx); @@ -481,7 +493,7 @@ int bdrv_all_find_snapshot(const char *name, BlockDriverState **first_bad_bs) AioContext *ctx = bdrv_get_aio_context(bs); aio_context_acquire(ctx); - if (bdrv_can_snapshot(bs)) { + if (bdrv_all_snapshots_includes_bs(bs)) { err = bdrv_snapshot_find(bs, &sn, name); } aio_context_release(ctx); @@ -512,7 +524,7 @@ int bdrv_all_create_snapshot(QEMUSnapshotInfo *sn, if (bs == vm_state_bs) { sn->vm_state_size = vm_state_size; err = bdrv_snapshot_create(bs, sn); - } else if (bdrv_can_snapshot(bs)) { + } else if (bdrv_all_snapshots_includes_bs(bs)) { sn->vm_state_size = 0; err = bdrv_snapshot_create(bs, sn); } @@ -538,7 +550,7 @@ BlockDriverState *bdrv_all_find_vmstate_bs(void) bool found; aio_context_acquire(ctx); - found = bdrv_can_snapshot(bs); + found = bdrv_all_snapshots_includes_bs(bs) && bdrv_can_snapshot(bs); aio_context_release(ctx); if (found) {