From patchwork Thu Mar 19 18:53:16 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Max Reitz X-Patchwork-Id: 452151 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id CB6BD140083 for ; Fri, 20 Mar 2015 05:57:33 +1100 (AEDT) Received: from localhost ([::1]:40637 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YYfdM-0007B4-3u for incoming@patchwork.ozlabs.org; Thu, 19 Mar 2015 14:57:32 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43513) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YYfZT-0007x9-A5 for qemu-devel@nongnu.org; Thu, 19 Mar 2015 14:53:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YYfZP-0002JQ-VH for qemu-devel@nongnu.org; Thu, 19 Mar 2015 14:53:31 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51615) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YYfZI-0002Hn-2B; Thu, 19 Mar 2015 14:53:20 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t2JIrJdq016926 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 19 Mar 2015 14:53:19 -0400 Received: from localhost (dhcp-17-47.bos.redhat.com [10.18.17.47]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t2JIrI7E021087 (version=TLSv1/SSLv3 cipher=AES128-GCM-SHA256 bits=128 verify=NO); Thu, 19 Mar 2015 14:53:18 -0400 From: Max Reitz To: qemu-block@nongnu.org Date: Thu, 19 Mar 2015 14:53:16 -0400 Message-Id: <1426791197-7793-2-git-send-email-mreitz@redhat.com> In-Reply-To: <1426791197-7793-1-git-send-email-mreitz@redhat.com> References: <1426791197-7793-1-git-send-email-mreitz@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: Kevin Wolf , qemu-devel@nongnu.org, Stefan Hajnoczi , Max Reitz Subject: [Qemu-devel] [PATCH v2 1/2] block: driver should override flags in bdrv_open() X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org The BDRV_O_PROTOCOL flag should have an impact only if no driver is specified explicitly. Therefore, if bdrv_open() is called with an explicit block driver argument (either through the options QDict or through the drv parameter) and that block driver is a protocol block driver, BDRV_O_PROTOCOL should be set; if it is a format block driver, BDRV_O_PROTOCOL should be unset. While there was code to unset the flag in case a format block driver has been selected, it only followed the bdrv_fill_options() function call whereas the flag in fact needs to be adjusted before it is used there. With that change, BDRV_O_PROTOCOL will always be set if the BDS should be a protocol driver; if the driver has been specified explicitly, the new code will set it; and bdrv_fill_options() will only "probe" a protocol driver if BDRV_O_PROTOCOL is set. The probing after bdrv_fill_options() cannot select a protocol driver. Thus, bdrv_open_image() to open BDS.file is never called if a protocol BDS is about to be created. With that change in turn it is impossible to call bdrv_open_common() with a protocol drv and file != NULL, which allows us to remove the bdrv_swap() call. This change breaks a test case in qemu-iotest 051: "-drive file=t.qcow2,file.driver=qcow2" now works because the explicitly specified "qcow2" overrides the BDRV_O_PROTOCOL which is automatically set for the "file" BDS (and the filename is just passed down). Therefore, this patch removes that test case. Signed-off-by: Max Reitz --- block.c | 49 +++++++++++++++++++++++++++++----------------- tests/qemu-iotests/051 | 1 - tests/qemu-iotests/051.out | 3 --- 3 files changed, 31 insertions(+), 22 deletions(-) diff --git a/block.c b/block.c index 0fe97de..4c620b1 100644 --- a/block.c +++ b/block.c @@ -992,14 +992,6 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file, } qdict_del(options, "node-name"); - /* bdrv_open() with directly using a protocol as drv. This layer is already - * opened, so assign it to bs (while file becomes a closed BlockDriverState) - * and return immediately. */ - if (file != NULL && drv->bdrv_file_open) { - bdrv_swap(file, bs); - return 0; - } - bs->open_flags = flags; bs->guest_block_size = 512; bs->request_alignment = 512; @@ -1127,14 +1119,17 @@ static QDict *parse_json_filename(const char *filename, Error **errp) /* * Fills in default options for opening images and converts the legacy * filename/flags pair to option QDict entries. + * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a + * block driver has been specified explicitly. */ -static int bdrv_fill_options(QDict **options, const char **pfilename, int flags, - BlockDriver *drv, Error **errp) +static int bdrv_fill_options(QDict **options, const char **pfilename, + int *flags, BlockDriver *drv, Error **errp) { const char *filename = *pfilename; const char *drvname; - bool protocol = flags & BDRV_O_PROTOCOL; + bool protocol = *flags & BDRV_O_PROTOCOL; bool parse_filename = false; + BlockDriver *tmp_drv; Error *local_err = NULL; /* Parse json: pseudo-protocol */ @@ -1152,6 +1147,24 @@ static int bdrv_fill_options(QDict **options, const char **pfilename, int flags, *pfilename = filename = NULL; } + drvname = qdict_get_try_str(*options, "driver"); + + /* If the user has explicitly specified the driver, this choice should + * override the BDRV_O_PROTOCOL flag */ + tmp_drv = drv; + if (!tmp_drv && drvname) { + tmp_drv = bdrv_find_format(drvname); + } + if (tmp_drv) { + protocol = tmp_drv->bdrv_file_open; + } + + if (protocol) { + *flags |= BDRV_O_PROTOCOL; + } else { + *flags &= ~BDRV_O_PROTOCOL; + } + /* Fetch the file name from the options QDict if necessary */ if (protocol && filename) { if (!qdict_haskey(*options, "filename")) { @@ -1166,7 +1179,6 @@ static int bdrv_fill_options(QDict **options, const char **pfilename, int flags, /* Find the right block driver */ filename = qdict_get_try_str(*options, "filename"); - drvname = qdict_get_try_str(*options, "driver"); if (drv) { if (drvname) { @@ -1502,7 +1514,7 @@ int bdrv_open(BlockDriverState **pbs, const char *filename, options = qdict_new(); } - ret = bdrv_fill_options(&options, &filename, flags, drv, &local_err); + ret = bdrv_fill_options(&options, &filename, &flags, drv, &local_err); if (local_err) { goto fail; } @@ -1521,11 +1533,6 @@ int bdrv_open(BlockDriverState **pbs, const char *filename, } assert(drvname || !(flags & BDRV_O_PROTOCOL)); - if (drv && !drv->bdrv_file_open) { - /* If the user explicitly wants a format driver here, we'll need to add - * another layer for the protocol in bs->file */ - flags &= ~BDRV_O_PROTOCOL; - } bs->options = options; options = qdict_clone_shallow(options); @@ -1562,6 +1569,12 @@ int bdrv_open(BlockDriverState **pbs, const char *filename, goto fail; } + /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */ + assert(!!(flags & BDRV_O_PROTOCOL) == !!drv->bdrv_file_open); + /* file must be NULL if a protocol BDS is about to be created + * (the inverse results in an error message from bdrv_open_common()) */ + assert(!(flags & BDRV_O_PROTOCOL) || !file); + /* Open the image */ ret = bdrv_open_common(bs, file, options, flags, drv, &local_err); if (ret < 0) { diff --git a/tests/qemu-iotests/051 b/tests/qemu-iotests/051 index 0360f37..4a8055b 100755 --- a/tests/qemu-iotests/051 +++ b/tests/qemu-iotests/051 @@ -194,7 +194,6 @@ echo === Specifying the protocol layer === echo run_qemu -drive file="$TEST_IMG",file.driver=file -run_qemu -drive file="$TEST_IMG",file.driver=qcow2 echo echo === Leaving out required options === diff --git a/tests/qemu-iotests/051.out b/tests/qemu-iotests/051.out index 2890eac..652dd63 100644 --- a/tests/qemu-iotests/051.out +++ b/tests/qemu-iotests/051.out @@ -253,9 +253,6 @@ Testing: -drive file=TEST_DIR/t.qcow2,file.driver=file QEMU X.Y.Z monitor - type 'help' for more information (qemu) qququiquit -Testing: -drive file=TEST_DIR/t.qcow2,file.driver=qcow2 -QEMU_PROG: -drive file=TEST_DIR/t.qcow2,file.driver=qcow2: Block format 'qcow2' used by device '' doesn't support the option 'filename' - === Leaving out required options ===