From patchwork Fri Apr 22 17:42:30 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 8914741 Return-Path: X-Original-To: patchwork-qemu-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id EA225BF29F for ; Fri, 22 Apr 2016 17:45:09 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 46906202BE for ; Fri, 22 Apr 2016 17:45:09 +0000 (UTC) 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.kernel.org (Postfix) with ESMTPS id A0BC4201F2 for ; Fri, 22 Apr 2016 17:45:07 +0000 (UTC) Received: from localhost ([::1]:36976 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1atf8c-0007pj-Tm for patchwork-qemu-devel@patchwork.kernel.org; Fri, 22 Apr 2016 13:45:06 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38235) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1atf6U-0002Ux-31 for qemu-devel@nongnu.org; Fri, 22 Apr 2016 13:42:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1atf6T-0006V5-3R for qemu-devel@nongnu.org; Fri, 22 Apr 2016 13:42:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59038) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1atf6P-0006SV-PC; Fri, 22 Apr 2016 13:42:49 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 64AF3C04B307; Fri, 22 Apr 2016 17:42:49 +0000 (UTC) Received: from noname.redhat.com (ovpn-116-64.ams2.redhat.com [10.36.116.64]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u3MHgiPO021616; Fri, 22 Apr 2016 13:42:47 -0400 From: Kevin Wolf To: qemu-block@nongnu.org Date: Fri, 22 Apr 2016 19:42:30 +0200 Message-Id: <1461346962-4676-2-git-send-email-kwolf@redhat.com> In-Reply-To: <1461346962-4676-1-git-send-email-kwolf@redhat.com> References: <1461346962-4676-1-git-send-email-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v2 01/13] block: Make sure throttled BDSes always have a BB 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, berto@igalia.com, qemu-devel@nongnu.org, mreitz@redhat.com, stefanha@redhat.com, pbonzini@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP It was already true in principle that a throttled BDS always has a BB attached, except that the order of operations while attaching or detaching a BDS to/from a BB wasn't careful enough. This commit breaks graph manipulations while I/O throttling is enabled. It would have been possible to keep things working with some temporary hacks, but quite cumbersome, so it's not worth the hassle. We'll fix things again in a minute. Signed-off-by: Kevin Wolf Reviewed-by: Eric Blake Reviewed-by: Alberto Garcia --- block.c | 14 ++++++++++++++ block/block-backend.c | 3 +++ blockdev.c | 4 ++-- tests/test-throttle.c | 11 ++++++++--- 4 files changed, 27 insertions(+), 5 deletions(-) diff --git a/block.c b/block.c index 6cbad0e..5e907e7 100644 --- a/block.c +++ b/block.c @@ -2261,8 +2261,22 @@ static void swap_feature_fields(BlockDriverState *bs_top, assert(!bs_new->throttle_state); if (bs_top->throttle_state) { + /* + * FIXME Need to break I/O throttling with graph manipulations + * temporarily because of conflicting invariants (3. will go away when + * throttling is fully converted to work on BlockBackends): + * + * 1. Every BlockBackend has a single root BDS + * 2. I/O throttling functions require an attached BlockBackend + * 3. We need to first enable throttling on the new BDS and then + * disable it on the old one (because of throttle group refcounts) + */ +#if 0 bdrv_io_limits_enable(bs_new, throttle_group_get_name(bs_top)); bdrv_io_limits_disable(bs_top); +#else + abort(); +#endif } } diff --git a/block/block-backend.c b/block/block-backend.c index 9538e79..e4839ca 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -420,6 +420,9 @@ void blk_remove_bs(BlockBackend *blk) notifier_list_notify(&blk->remove_bs_notifiers, blk); blk_update_root_state(blk); + if (blk->root->bs->throttle_state) { + bdrv_io_limits_disable(blk->root->bs); + } blk->root->bs->blk = NULL; bdrv_root_unref_child(blk->root); diff --git a/blockdev.c b/blockdev.c index f1f520a..29ded1b 100644 --- a/blockdev.c +++ b/blockdev.c @@ -2570,8 +2570,6 @@ void qmp_blockdev_change_medium(const char *device, const char *filename, goto fail; } - blk_apply_root_state(blk, medium_bs); - bdrv_add_key(medium_bs, NULL, &err); if (err) { error_propagate(errp, err); @@ -2596,6 +2594,8 @@ void qmp_blockdev_change_medium(const char *device, const char *filename, goto fail; } + blk_apply_root_state(blk, medium_bs); + qmp_blockdev_close_tray(device, errp); fail: diff --git a/tests/test-throttle.c b/tests/test-throttle.c index 744a524..77b95d6 100644 --- a/tests/test-throttle.c +++ b/tests/test-throttle.c @@ -574,11 +574,16 @@ static void test_accounting(void) static void test_groups(void) { ThrottleConfig cfg1, cfg2; + BlockBackend *blk1, *blk2, *blk3; BlockDriverState *bdrv1, *bdrv2, *bdrv3; - bdrv1 = bdrv_new(); - bdrv2 = bdrv_new(); - bdrv3 = bdrv_new(); + blk1 = blk_new_with_bs(&error_abort); + blk2 = blk_new_with_bs(&error_abort); + blk3 = blk_new_with_bs(&error_abort); + + bdrv1 = blk_bs(blk1); + bdrv2 = blk_bs(blk2); + bdrv3 = blk_bs(blk3); g_assert(bdrv1->throttle_state == NULL); g_assert(bdrv2->throttle_state == NULL);