From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53990) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WLIKD-00031l-F8 for qemu-devel@nongnu.org; Wed, 05 Mar 2014 15:22:02 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WLIK8-0002Lg-IV for qemu-devel@nongnu.org; Wed, 05 Mar 2014 15:21:57 -0500 Received: from mx1.redhat.com ([209.132.183.28]:59402) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WLIK8-0002LT-9p for qemu-devel@nongnu.org; Wed, 05 Mar 2014 15:21:52 -0500 Message-ID: <5317875A.7040007@redhat.com> Date: Wed, 05 Mar 2014 21:21:46 +0100 From: Max Reitz MIME-Version: 1.0 References: <1393860533-2063-1-git-send-email-mreitz@redhat.com> <1393860533-2063-3-git-send-email-mreitz@redhat.com> <20140305160455.GD1709@irqsave.net> <531781D4.40800@redhat.com> <20140305202047.GA4514@irqsave.net> In-Reply-To: <20140305202047.GA4514@irqsave.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH 02/10] block/json: Add JSON protocol driver List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: =?ISO-8859-1?Q?Beno=EEt_Canet?= Cc: Kevin Wolf , qemu-devel@nongnu.org, Stefan Hajnoczi On 05.03.2014 21:20, Beno=EEt Canet wrote: > The Wednesday 05 Mar 2014 =E0 20:58:12 (+0100), Max Reitz wrote : >> On 05.03.2014 17:04, Beno=EEt Canet wrote: >>> The Monday 03 Mar 2014 =E0 16:28:45 (+0100), Max Reitz wrote : >>>> Add a JSON protocol driver which allows supplying block driver optio= ns >>>> through the filename rather than separately. Other than that, it is = a >>>> pure passthrough driver which identifies itself as a filter. >>>> >>>> This patch implements the functions bdrv_parse_filename(), >>>> bdrv_file_open(), bdrv_close(), bdrv_aio_readv(), bdrv_aio_writev(), >>>> bdrv_getlength(), bdrv_refresh_limits() and bdrv_get_info(). >>>> >>>> Signed-off-by: Max Reitz >>>> --- >>>> block/Makefile.objs | 2 +- >>>> block/json.c | 136 ++++++++++++++++++++++++++++++++++++++++= ++++++++++++ >>>> 2 files changed, 137 insertions(+), 1 deletion(-) >>>> create mode 100644 block/json.c >>>> >>>> diff --git a/block/Makefile.objs b/block/Makefile.objs >>>> index fd88c03..d4b70f4 100644 >>>> --- a/block/Makefile.objs >>>> +++ b/block/Makefile.objs >>>> @@ -5,7 +5,7 @@ block-obj-y +=3D qed-check.o >>>> block-obj-$(CONFIG_VHDX) +=3D vhdx.o vhdx-endian.o vhdx-log.o >>>> block-obj-$(CONFIG_QUORUM) +=3D quorum.o >>>> block-obj-y +=3D parallels.o blkdebug.o blkverify.o >>>> -block-obj-y +=3D snapshot.o qapi.o >>>> +block-obj-y +=3D snapshot.o qapi.o json.o >>>> block-obj-$(CONFIG_WIN32) +=3D raw-win32.o win32-aio.o >>>> block-obj-$(CONFIG_POSIX) +=3D raw-posix.o >>>> block-obj-$(CONFIG_LINUX_AIO) +=3D linux-aio.o >>>> diff --git a/block/json.c b/block/json.c >>>> new file mode 100644 >>>> index 0000000..6d63cf6 >>>> --- /dev/null >>>> +++ b/block/json.c >>>> @@ -0,0 +1,136 @@ >>>> +/* >>>> + * JSON filename wrapper protocol driver >>>> + * >>>> + * Copyright (c) 2014 Red Hat Inc. >>>> + * >>>> + * This program is free software; you can redistribute it and/or mo= dify >>>> + * it under the terms of the GNU General Public License as publishe= d by >>>> + * the Free Software Foundation; either version 2 of the License, o= r >>>> + * (at your option) any later version. >>>> + * >>>> + * This program is distributed in the hope that it will be useful, >>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of >>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the >>>> + * GNU General Public License for more details. >>>> + * >>>> + * You should have received a copy of the GNU General Public Licens= e >>>> + * along with this program. If not, see . >>>> + */ >>>> + >>>> +#include "qemu-common.h" >>>> +#include "block/block_int.h" >>>> +#include "qapi/qmp/qdict.h" >>>> +#include "qapi/qmp/qjson.h" >>>> + >>>> +static void json_parse_filename(const char *filename, QDict *option= s, >>>> + Error **errp) >>>> +{ >>>> + QObject *file_options_obj; >>>> + QDict *full_options; >>>> + >>>> + if (!strstart(filename, "json:", &filename)) { >>>> + error_setg(errp, "Unknown protocol prefix for JSON block dr= iver"); >>>> + return; >>>> + } >>>> + >>>> + file_options_obj =3D qobject_from_json(filename); >>>> + if (!file_options_obj) { >>>> + error_setg(errp, "Could not parse the JSON options"); >>>> + return; >>>> + } >>>> + >>>> + if (qobject_type(file_options_obj) !=3D QTYPE_QDICT) { >>>> + qobject_decref(file_options_obj); >>>> + error_setg(errp, "Invalid JSON object"); >>>> + return; >>>> + } >>>> + >>>> + full_options =3D qdict_new(); >>>> + qdict_put_obj(full_options, "x-options", file_options_obj); >>>> + qdict_flatten(full_options); >>>> + >>>> + qdict_join(options, full_options, true); >>>> + assert(qdict_size(full_options) =3D=3D 0); >>>> + QDECREF(full_options); >>>> +} >>>> + >>>> +static int json_open(BlockDriverState *bs, QDict *options, int flag= s, >>>> + Error **errp) >>>> +{ >>>> + int ret; >>>> + >>>> + assert(bs->file =3D=3D NULL); >>>> + ret =3D bdrv_open_image(&bs->file, NULL, options, "x-options", = flags, false, >>>> + errp); >>>> + if (ret < 0) { >>>> + return ret; >>>> + } >>>> + >>>> + return 0; >>> Why not ? >>> return ret; >>> } >>> >>> Do you plan to enrich this code path later ? >> You're right, that'd be shorter. It's just that I'm so in the habit >> of writing "ret =3D foo(); if (ret < 0) { return ret; / goto fail; }" >> that I didn't notice. ;-) >> >>>> +} >>>> + >>>> +static void json_close(BlockDriverState *bs) >>>> +{ >>>> +} >>>> + >>>> +static BlockDriverAIOCB *json_aio_readv(BlockDriverState *bs, >>>> + int64_t sector_num, QEMUIOV= ector *qiov, >>>> + int nb_sectors, >>>> + BlockDriverCompletionFunc *= cb, >>>> + void *opaque) >>>> +{ >>>> + return bdrv_aio_readv(bs->file, sector_num, qiov, nb_sectors, c= b, opaque); >>>> +} >>>> + >>>> +static BlockDriverAIOCB *json_aio_writev(BlockDriverState *bs, >>>> + int64_t sector_num, QEMUIO= Vector *qiov, >>>> + int nb_sectors, >>>> + BlockDriverCompletionFunc = *cb, >>>> + void *opaque) >>>> +{ >>>> + return bdrv_aio_writev(bs->file, sector_num, qiov, nb_sectors, = cb, opaque); >>>> +} >>>> + >>>> +static int64_t json_getlength(BlockDriverState *bs) >>>> +{ >>>> + return bdrv_getlength(bs->file); >>>> +} >>>> + >>>> +static int json_refresh_limits(BlockDriverState *bs) >>>> +{ >>>> + bs->bl =3D bs->file->bl; >>>> + return 0; >>>> +} >>>> + >>>> +static int json_get_info(BlockDriverState *bs, BlockDriverInfo *bdi= ) >>>> +{ >>>> + return bdrv_get_info(bs->file, bdi); >>>> +} >>>> + >>>> +static BlockDriver bdrv_json =3D { >>>> + .format_name =3D "json", >>>> + .protocol_name =3D "json", >>>> + .instance_size =3D 0, >>>> + >>>> + .bdrv_parse_filename =3D json_parse_filename, >>>> + .bdrv_file_open =3D json_open, >>>> + .bdrv_close =3D json_close, >>>> + >>>> + .bdrv_aio_readv =3D json_aio_readv, >>>> + .bdrv_aio_writev =3D json_aio_writev, >>>> + >>>> + .has_variable_length =3D true, >>>> + .bdrv_getlength =3D json_getlength, >>>> + >>>> + .bdrv_refresh_limits =3D json_refresh_limits, >>>> + .bdrv_get_info =3D json_get_info, >>>> + >>>> + .authorizations =3D { true, true }, >>> Paolo make rewrite the snapshot authorization code. >>> In the new version you need >>> .is_filter =3D true; >>> .bdrv_recurse_is_first_children =3D your_implementation; >>> >>> I don't know when these patchset will be reviewed and merged so maybe= this >>> version is correct. >> I'll just rebase on top of Paolo's series then. > It's a sugestion made by Paolo. I wrote the actual code. > The series is : > "[PATCH] Rewrite block filter snapshot authorization mechanism" Okay, thank you again. :-) Max >> >> Thanks, >> >> Max >> >>>> +}; >>>> + >>>> +static void bdrv_json_init(void) >>>> +{ >>>> + bdrv_register(&bdrv_json); >>>> +} >>>> + >>>> +block_init(bdrv_json_init); >>>> --=20 >>>> 1.9.0 >>>> >>>> >>