From patchwork Mon Oct 14 15:39:29 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 11188977 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 3F81117D4 for ; Mon, 14 Oct 2019 15:41:05 +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 1E8C320873 for ; Mon, 14 Oct 2019 15:41:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1E8C320873 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]:51648 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iK2T2-0007jj-1p for patchwork-qemu-devel@patchwork.kernel.org; Mon, 14 Oct 2019 11:41:04 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60979) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iK2Rx-00063D-3f for qemu-devel@nongnu.org; Mon, 14 Oct 2019 11:39:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iK2Rv-0004Jc-LU for qemu-devel@nongnu.org; Mon, 14 Oct 2019 11:39:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51540) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iK2Rs-0004FP-Gb; Mon, 14 Oct 2019 11:39:52 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id AC51B30A7B9A; Mon, 14 Oct 2019 15:39:51 +0000 (UTC) Received: from localhost (ovpn-117-165.ams2.redhat.com [10.36.117.165]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7B9FF67268; Mon, 14 Oct 2019 15:39:47 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Subject: [PATCH v3 2/4] blkdebug: Allow taking/unsharing permissions Date: Mon, 14 Oct 2019 17:39:29 +0200 Message-Id: <20191014153931.20699-3-mreitz@redhat.com> In-Reply-To: <20191014153931.20699-1-mreitz@redhat.com> References: <20191014153931.20699-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.47]); Mon, 14 Oct 2019 15:39:51 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] 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: Kevin Wolf , Vladimir Sementsov-Ogievskiy , John Snow , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" Sometimes it is useful to be able to add a node to the block graph that takes or unshare a certain set of permissions for debugging purposes. This patch adds this capability to blkdebug. (Note that you cannot make blkdebug release or share permissions that it needs to take or cannot share, because this might result in assertion failures in the block layer. But if the blkdebug node has no parents, it will not take any permissions and share everything by default, so you can then freely choose what permissions to take and share.) Signed-off-by: Max Reitz --- qapi/block-core.json | 14 ++++++- block/blkdebug.c | 91 +++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 103 insertions(+), 2 deletions(-) diff --git a/qapi/block-core.json b/qapi/block-core.json index f66553aac7..054ce651de 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -3453,6 +3453,16 @@ # # @set-state: array of state-change descriptions # +# @take-child-perms: Permissions to take on @image in addition to what +# is necessary anyway (which depends on how the +# blkdebug node is used). Defaults to none. +# (since 4.2) +# +# @unshare-child-perms: Permissions not to share on @image in addition +# to what cannot be shared anyway (which depends +# on how the blkdebug node is used). Defaults +# to none. (since 4.2) +# # Since: 2.9 ## { 'struct': 'BlockdevOptionsBlkdebug', @@ -3462,7 +3472,9 @@ '*opt-write-zero': 'int32', '*max-write-zero': 'int32', '*opt-discard': 'int32', '*max-discard': 'int32', '*inject-error': ['BlkdebugInjectErrorOptions'], - '*set-state': ['BlkdebugSetStateOptions'] } } + '*set-state': ['BlkdebugSetStateOptions'], + '*take-child-perms': ['BlockPermission'], + '*unshare-child-perms': ['BlockPermission'] } } ## # @BlockdevOptionsBlklogwrites: diff --git a/block/blkdebug.c b/block/blkdebug.c index 5ae96c52b0..6807c03065 100644 --- a/block/blkdebug.c +++ b/block/blkdebug.c @@ -28,10 +28,14 @@ #include "qemu/cutils.h" #include "qemu/config-file.h" #include "block/block_int.h" +#include "block/qdict.h" #include "qemu/module.h" #include "qemu/option.h" +#include "qapi/qapi-visit-block-core.h" #include "qapi/qmp/qdict.h" +#include "qapi/qmp/qlist.h" #include "qapi/qmp/qstring.h" +#include "qapi/qobject-input-visitor.h" #include "sysemu/qtest.h" typedef struct BDRVBlkdebugState { @@ -44,6 +48,9 @@ typedef struct BDRVBlkdebugState { uint64_t opt_discard; uint64_t max_discard; + uint64_t take_child_perms; + uint64_t unshare_child_perms; + /* For blkdebug_refresh_filename() */ char *config_file; @@ -344,6 +351,67 @@ static void blkdebug_parse_filename(const char *filename, QDict *options, qdict_put_str(options, "x-image", filename); } +static int blkdebug_parse_perm_list(uint64_t *dest, QDict *options, + const char *prefix, Error **errp) +{ + int ret = 0; + QDict *subqdict = NULL; + QObject *crumpled_subqdict = NULL; + Visitor *v = NULL; + BlockPermissionList *perm_list = NULL, *element; + Error *local_err = NULL; + + qdict_extract_subqdict(options, &subqdict, prefix); + if (!qdict_size(subqdict)) { + goto out; + } + + crumpled_subqdict = qdict_crumple(subqdict, errp); + if (!crumpled_subqdict) { + ret = -EINVAL; + goto out; + } + + v = qobject_input_visitor_new(crumpled_subqdict); + visit_type_BlockPermissionList(v, NULL, &perm_list, &local_err); + if (local_err) { + error_propagate(errp, local_err); + ret = -EINVAL; + goto out; + } + + for (element = perm_list; element; element = element->next) { + *dest |= UINT64_C(1) << element->value; + } + +out: + qapi_free_BlockPermissionList(perm_list); + visit_free(v); + qobject_unref(subqdict); + qobject_unref(crumpled_subqdict); + return ret; +} + +static int blkdebug_parse_perms(BDRVBlkdebugState *s, QDict *options, + Error **errp) +{ + int ret; + + ret = blkdebug_parse_perm_list(&s->take_child_perms, options, + "take-child-perms.", errp); + if (ret < 0) { + return ret; + } + + ret = blkdebug_parse_perm_list(&s->unshare_child_perms, options, + "unshare-child-perms.", errp); + if (ret < 0) { + return ret; + } + + return 0; +} + static QemuOptsList runtime_opts = { .name = "blkdebug", .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head), @@ -419,6 +487,12 @@ static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags, /* Set initial state */ s->state = 1; + /* Parse permissions modifiers before opening the image file */ + ret = blkdebug_parse_perms(s, options, errp); + if (ret < 0) { + goto out; + } + /* Open the image file */ bs->file = bdrv_open_child(qemu_opt_get(opts, "x-image"), options, "image", bs, &child_file, false, &local_err); @@ -916,6 +990,21 @@ static int blkdebug_reopen_prepare(BDRVReopenState *reopen_state, return 0; } +static void blkdebug_child_perm(BlockDriverState *bs, BdrvChild *c, + const BdrvChildRole *role, + BlockReopenQueue *reopen_queue, + uint64_t perm, uint64_t shared, + uint64_t *nperm, uint64_t *nshared) +{ + BDRVBlkdebugState *s = bs->opaque; + + bdrv_filter_default_perms(bs, c, role, reopen_queue, perm, shared, + nperm, nshared); + + *nperm |= s->take_child_perms; + *nshared &= ~s->unshare_child_perms; +} + static const char *const blkdebug_strong_runtime_opts[] = { "config", "inject-error.", @@ -940,7 +1029,7 @@ static BlockDriver bdrv_blkdebug = { .bdrv_file_open = blkdebug_open, .bdrv_close = blkdebug_close, .bdrv_reopen_prepare = blkdebug_reopen_prepare, - .bdrv_child_perm = bdrv_filter_default_perms, + .bdrv_child_perm = blkdebug_child_perm, .bdrv_getlength = blkdebug_getlength, .bdrv_refresh_filename = blkdebug_refresh_filename,