From nobody Wed Nov 5 14:57:46 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1497360966934221.14511069434673; Tue, 13 Jun 2017 06:36:06 -0700 (PDT) Received: from localhost ([::1]:43314 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dKlzF-0002kt-IH for importer@patchew.org; Tue, 13 Jun 2017 09:36:01 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48316) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dKlwz-0001Fs-7J for qemu-devel@nongnu.org; Tue, 13 Jun 2017 09:33:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dKlww-0000Rw-Mf for qemu-devel@nongnu.org; Tue, 13 Jun 2017 09:33:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54172) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dKlww-0000Rf-Dp for qemu-devel@nongnu.org; Tue, 13 Jun 2017 09:33:38 -0400 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4860FC0272DA; Tue, 13 Jun 2017 13:33:37 +0000 (UTC) Received: from localhost (ovpn-117-200.ams2.redhat.com [10.36.117.200]) by smtp.corp.redhat.com (Postfix) with ESMTP id CC25C8C58B; Tue, 13 Jun 2017 13:33:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 4860FC0272DA Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=stefanha@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 4860FC0272DA From: Stefan Hajnoczi To: qemu-devel@nongnu.org Date: Tue, 13 Jun 2017 14:33:21 +0100 Message-Id: <20170613133329.23653-2-stefanha@redhat.com> In-Reply-To: <20170613133329.23653-1-stefanha@redhat.com> References: <20170613133329.23653-1-stefanha@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Tue, 13 Jun 2017 13:33:37 +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 Subject: [Qemu-devel] [PATCH v7 1/9] block: add bdrv_measure() API 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: Kevin Wolf , John Snow , Nir Soffer , Maor Lipchuk , Stefan Hajnoczi , Alberto Garcia Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" bdrv_measure() provides a conservative maximum for the size of a new image. This information is handy if storage needs to be allocated (e.g. a SAN or an LVM volume) ahead of time. Signed-off-by: Stefan Hajnoczi Reviewed-by: Alberto Garcia --- v6: * Change bdrv_measure() return type to BlockMeasureInfo * [Eric] * Clarify that holes in sparse POSIX files are still counted [Eric] --- qapi/block-core.json | 25 +++++++++++++++++++++++++ include/block/block.h | 2 ++ include/block/block_int.h | 2 ++ block.c | 35 +++++++++++++++++++++++++++++++++++ 4 files changed, 64 insertions(+) diff --git a/qapi/block-core.json b/qapi/block-core.json index f85c223..7973f24 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -464,6 +464,31 @@ '*dirty-bitmaps': ['BlockDirtyInfo'] } } =20 ## +# @BlockMeasureInfo: +# +# Image file size calculation information. This structure describes the s= ize +# requirements for creating a new image file. +# +# The size requirements depend on the new image file format. File size al= ways +# equals virtual disk size for the 'raw' format, even for sparse POSIX fil= es. +# Compact formats such as 'qcow2' represent unallocated and zero regions +# efficiently so file size may be smaller than virtual disk size. +# +# The values are upper bounds that are guaranteed to fit the new image fil= e. +# Subsequent modification, such as internal snapshot or bitmap creation, m= ay +# require additional space and is not covered here. +# +# @required: Size required for a new image file, in bytes. +# +# @fully-allocated: Image file size, in bytes, once data has been written +# to all sectors. +# +# Since: 2.10 +## +{ 'struct': 'BlockMeasureInfo', + 'data': {'required': 'int', 'fully-allocated': 'int'} } + +## # @query-block: # # Get a list of BlockInfo for all virtual block devices. diff --git a/include/block/block.h b/include/block/block.h index 9b355e9..e2c6a0d 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -304,6 +304,8 @@ int bdrv_truncate(BdrvChild *child, int64_t offset, Err= or **errp); int64_t bdrv_nb_sectors(BlockDriverState *bs); int64_t bdrv_getlength(BlockDriverState *bs); int64_t bdrv_get_allocated_file_size(BlockDriverState *bs); +BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts, + BlockDriverState *in_bs, Error **errp); void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr); void bdrv_refresh_limits(BlockDriverState *bs, Error **errp); int bdrv_commit(BlockDriverState *bs); diff --git a/include/block/block_int.h b/include/block/block_int.h index cb78c4f..614cec9 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -208,6 +208,8 @@ struct BlockDriver { int64_t (*bdrv_getlength)(BlockDriverState *bs); bool has_variable_length; int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs); + BlockMeasureInfo *(*bdrv_measure)(QemuOpts *opts, BlockDriverState *in= _bs, + Error **errp); =20 int coroutine_fn (*bdrv_co_pwritev_compressed)(BlockDriverState *bs, uint64_t offset, uint64_t bytes, QEMUIOVector *qiov); diff --git a/block.c b/block.c index fa1d06d..056400a 100644 --- a/block.c +++ b/block.c @@ -3446,6 +3446,41 @@ int64_t bdrv_get_allocated_file_size(BlockDriverStat= e *bs) return -ENOTSUP; } =20 +/* + * bdrv_measure: + * @drv: Format driver + * @opts: Creation options for new image + * @in_bs: Existing image containing data for new image (may be NULL) + * @errp: Error object + * Returns: A #BlockMeasureInfo (free using qapi_free_BlockMeasureInfo()) + * or NULL on error + * + * Calculate file size required to create a new image. + * + * If @in_bs is given then space for allocated clusters and zero clusters + * from that image are included in the calculation. If @opts contains a + * backing file that is shared by @in_bs then backing clusters are omitted + * from the calculation. + * + * If @in_bs is NULL then the calculation includes no allocated clusters + * unless a preallocation option is given in @opts. + * + * Note that @in_bs may use a different BlockDriver from @drv. + * + * If an error occurs the @errp pointer is set. + */ +BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts, + BlockDriverState *in_bs, Error **errp) +{ + if (!drv->bdrv_measure) { + error_setg(errp, "Block driver '%s' does not support size measurem= ent", + drv->format_name); + return NULL; + } + + return drv->bdrv_measure(opts, in_bs, errp); +} + /** * Return number of sectors on success, -errno on error. */ --=20 2.9.4