From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 314C0C433DB for ; Mon, 18 Jan 2021 14:06:35 +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 B19D22225C for ; Mon, 18 Jan 2021 14:06:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B19D22225C 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+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:44660 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l1VAv-0004sA-PD for qemu-devel@archiver.kernel.org; Mon, 18 Jan 2021 09:06:33 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:46588) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l1V9v-0004DW-BS for qemu-devel@nongnu.org; Mon, 18 Jan 2021 09:05:31 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:35671) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1l1V9t-0001x8-JJ for qemu-devel@nongnu.org; Mon, 18 Jan 2021 09:05:31 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1610978728; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=OTvTJgfmES4Wjv0XY9isP6A8JyUlfby4PK9m1zZNous=; b=cS14qZOOKI521hwuzoHDWU48wKrrFPE2diIyeKjTjyx5vIvvOqbs7AUa/DgqF8nFITJ1Qc pajmLRxDa8poCKLztTP0QgLj9HNsnP3O6CGDWUijVGcj3EBeytG0hvLeUQcLUUpjtDvAca 6kpBMYMW19oKBoJAKhnIw8uHV938h5E= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-36-klh66MFrN6G6dDc-z2nFrA-1; Mon, 18 Jan 2021 09:05:25 -0500 X-MC-Unique: klh66MFrN6G6dDc-z2nFrA-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 24F9A190A7A1; Mon, 18 Jan 2021 14:05:24 +0000 (UTC) Received: from merkur.fritz.box (ovpn-115-75.ams2.redhat.com [10.36.115.75]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A888D1001E73; Mon, 18 Jan 2021 14:05:22 +0000 (UTC) Date: Mon, 18 Jan 2021 15:05:21 +0100 From: Kevin Wolf To: Vladimir Sementsov-Ogievskiy Subject: Re: [PATCH v2 02/36] tests/test-bdrv-graph-mod: add test_parallel_perm_update Message-ID: <20210118140521.GC11555@merkur.fritz.box> References: <20201127144522.29991-1-vsementsov@virtuozzo.com> <20201127144522.29991-3-vsementsov@virtuozzo.com> MIME-Version: 1.0 In-Reply-To: <20201127144522.29991-3-vsementsov@virtuozzo.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kwolf@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=63.128.21.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.175, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action 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: qemu-block@nongnu.org, armbru@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com, den@openvz.org, jsnow@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Am 27.11.2020 um 15:44 hat Vladimir Sementsov-Ogievskiy geschrieben: > Add test to show that simple DFS recursion order is not correct for > permission update. Correct order is topological-sort order, which will > be introduced later. > > Consider the block driver which has two filter children: one active > with exclusive write access and one inactive with no specific > permissions. > > And, these two children has a common base child, like this: > > ┌─────┐ ┌──────┐ > │ fl2 │ ◀── │ top │ > └─────┘ └──────┘ > │ │ > │ │ w > │ ▼ > │ ┌──────┐ > │ │ fl1 │ > │ └──────┘ > │ │ > │ │ w > │ ▼ > │ ┌──────┐ > └───────▶ │ base │ > └──────┘ > > So, exclusive write is propagated. > > Assume, we want to make fl2 active instead of fl1. > So, we set some option for top driver and do permission update. > > If permission update (remember, it's DFS) goes first through > top->fl1->base branch it will succeed: it firstly drop exclusive write > permissions and than apply them for another BdrvChildren. > But if permission update goes first through top->fl2->base branch it > will fail, as when we try to update fl2->base child, old not yet > updated fl1->base child will be in conflict. > > Now test fails, so it runs only with -d flag. To run do > > ./test-bdrv-graph-mod -d -p /bdrv-graph-mod/parallel-perm-update > > from /tests. > > Signed-off-by: Vladimir Sementsov-Ogievskiy > --- > tests/test-bdrv-graph-mod.c | 64 +++++++++++++++++++++++++++++++++++++ > 1 file changed, 64 insertions(+) > > diff --git a/tests/test-bdrv-graph-mod.c b/tests/test-bdrv-graph-mod.c > index 3b9e6f242f..27e3361a60 100644 > --- a/tests/test-bdrv-graph-mod.c > +++ b/tests/test-bdrv-graph-mod.c > @@ -232,6 +232,68 @@ static void test_parallel_exclusive_write(void) > bdrv_unref(top); > } > > +static void write_to_file_perms(BlockDriverState *bs, BdrvChild *c, > + BdrvChildRole role, > + BlockReopenQueue *reopen_queue, > + uint64_t perm, uint64_t shared, > + uint64_t *nperm, uint64_t *nshared) > +{ > + if (bs->file && c == bs->file) { > + *nperm = BLK_PERM_WRITE; > + *nshared = BLK_PERM_ALL & ~BLK_PERM_WRITE; > + } else { > + *nperm = 0; > + *nshared = BLK_PERM_ALL; > + } > +} > + > +static BlockDriver bdrv_write_to_file = { > + .format_name = "tricky-perm", > + .bdrv_child_perm = write_to_file_perms, > +}; > + > +static void test_parallel_perm_update(void) > +{ > + BlockDriverState *top = no_perm_node("top"); > + BlockDriverState *tricky = > + bdrv_new_open_driver(&bdrv_write_to_file, "tricky", BDRV_O_RDWR, > + &error_abort); > + BlockDriverState *base = no_perm_node("base"); > + BlockDriverState *fl1 = pass_through_node("fl1"); > + BlockDriverState *fl2 = pass_through_node("fl2"); > + BdrvChild *c_fl1, *c_fl2; > + > + bdrv_attach_child(top, tricky, "file", &child_of_bds, BDRV_CHILD_DATA, > + &error_abort); > + c_fl1 = bdrv_attach_child(tricky, fl1, "first", &child_of_bds, > + BDRV_CHILD_FILTERED, &error_abort); > + c_fl2 = bdrv_attach_child(tricky, fl2, "second", &child_of_bds, > + BDRV_CHILD_FILTERED, &error_abort); > + bdrv_attach_child(fl1, base, "backing", &child_of_bds, BDRV_CHILD_FILTERED, > + &error_abort); > + bdrv_attach_child(fl2, base, "backing", &child_of_bds, BDRV_CHILD_FILTERED, > + &error_abort); > + bdrv_ref(base); > + > + /* Select fl1 as first child to be active */ > + tricky->file = c_fl1; > + bdrv_child_refresh_perms(top, top->children.lh_first, &error_abort); > + > + assert(c_fl1->perm & BLK_PERM_WRITE); > + > + /* Now, try to switch active child and update permissions */ > + tricky->file = c_fl2; > + bdrv_child_refresh_perms(top, top->children.lh_first, &error_abort); > + > + assert(c_fl2->perm & BLK_PERM_WRITE); > + > + /* Switch once more, to not care about real child order in the list */ > + tricky->file = c_fl1; > + bdrv_child_refresh_perms(top, top->children.lh_first, &error_abort); > + > + assert(c_fl1->perm & BLK_PERM_WRITE); Should we also assert in each case that the we don't hole the write permission for the inactive child? Kevin