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=-6.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 C7868C11D05 for ; Thu, 20 Feb 2020 16:17:44 +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 915F920659 for ; Thu, 20 Feb 2020 16:17:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="B9o5mqZ2" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 915F920659 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]:45292 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j4oWF-0001nH-Lp for qemu-devel@archiver.kernel.org; Thu, 20 Feb 2020 11:17:43 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:55162) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j4oQ4-0008Ra-SX for qemu-devel@nongnu.org; Thu, 20 Feb 2020 11:11:22 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j4oQ3-00076o-G7 for qemu-devel@nongnu.org; Thu, 20 Feb 2020 11:11:20 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:47793 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1j4oQ3-00075O-CA for qemu-devel@nongnu.org; Thu, 20 Feb 2020 11:11:19 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582215077; 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=Y1j2F+uA43I/ghbVuJetmMh/0pWyi7QRriUjNOiBmpQ=; b=B9o5mqZ2Ynw64S0HyPzeBZvOu1qW0PTFz6SiSD4o4cx6kFiNloKYYqHCphfgP/St028BWi C4Ib0g+60IF+xz/0zhc9UpL+LvXVFj6A6sKRCrS87wXHvb9yM0IGTnTgxehJ14PP9e9xwX rk6uGlWUAJ1fPzR4zxEp4z22FFtJLRw= 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-211-i2eJYoZyPcqU61b1XfbvJw-1; Thu, 20 Feb 2020 11:11:13 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9E17E1085444; Thu, 20 Feb 2020 16:11:12 +0000 (UTC) Received: from localhost (unknown [10.36.118.38]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1E0155D9E2; Thu, 20 Feb 2020 16:11:05 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Subject: [PULL 11/18] block: Generic file creation fallback Date: Thu, 20 Feb 2020 17:07:03 +0100 Message-Id: <20200220160710.533297-12-mreitz@redhat.com> In-Reply-To: <20200220160710.533297-1-mreitz@redhat.com> References: <20200220160710.533297-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-MC-Unique: i2eJYoZyPcqU61b1XfbvJw-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.120 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 , Peter Maydell , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" If a protocol driver does not support image creation, we can see whether maybe the file exists already. If so, just truncating it will be sufficient. Signed-off-by: Max Reitz Message-Id: <20200122164532.178040-3-mreitz@redhat.com> Signed-off-by: Max Reitz --- block.c | 159 +++++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 147 insertions(+), 12 deletions(-) diff --git a/block.c b/block.c index 08372ced26..308a91c96b 100644 --- a/block.c +++ b/block.c @@ -532,20 +532,139 @@ out: return ret; } =20 -int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp) +/** + * Helper function for bdrv_create_file_fallback(): Resize @blk to at + * least the given @minimum_size. + * + * On success, return @blk's actual length. + * Otherwise, return -errno. + */ +static int64_t create_file_fallback_truncate(BlockBackend *blk, + int64_t minimum_size, Error *= *errp) { - BlockDriver *drv; + Error *local_err =3D NULL; + int64_t size; + int ret; + + ret =3D blk_truncate(blk, minimum_size, false, PREALLOC_MODE_OFF, &loc= al_err); + if (ret < 0 && ret !=3D -ENOTSUP) { + error_propagate(errp, local_err); + return ret; + } + + size =3D blk_getlength(blk); + if (size < 0) { + error_free(local_err); + error_setg_errno(errp, -size, + "Failed to inquire the new image file's length"); + return size; + } + + if (size < minimum_size) { + /* Need to grow the image, but we failed to do that */ + error_propagate(errp, local_err); + return -ENOTSUP; + } + + error_free(local_err); + local_err =3D NULL; + + return size; +} + +/** + * Helper function for bdrv_create_file_fallback(): Zero the first + * sector to remove any potentially pre-existing image header. + */ +static int create_file_fallback_zero_first_sector(BlockBackend *blk, + int64_t current_size, + Error **errp) +{ + int64_t bytes_to_clear; + int ret; + + bytes_to_clear =3D MIN(current_size, BDRV_SECTOR_SIZE); + if (bytes_to_clear) { + ret =3D blk_pwrite_zeroes(blk, 0, bytes_to_clear, BDRV_REQ_MAY_UNM= AP); + if (ret < 0) { + error_setg_errno(errp, -ret, + "Failed to clear the new image's first sector= "); + return ret; + } + } + + return 0; +} + +static int bdrv_create_file_fallback(const char *filename, BlockDriver *dr= v, + QemuOpts *opts, Error **errp) +{ + BlockBackend *blk; + QDict *options =3D qdict_new(); + int64_t size =3D 0; + char *buf =3D NULL; + PreallocMode prealloc; Error *local_err =3D NULL; int ret; =20 + size =3D qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0); + buf =3D qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC); + prealloc =3D qapi_enum_parse(&PreallocMode_lookup, buf, + PREALLOC_MODE_OFF, &local_err); + g_free(buf); + if (local_err) { + error_propagate(errp, local_err); + return -EINVAL; + } + + if (prealloc !=3D PREALLOC_MODE_OFF) { + error_setg(errp, "Unsupported preallocation mode '%s'", + PreallocMode_str(prealloc)); + return -ENOTSUP; + } + + qdict_put_str(options, "driver", drv->format_name); + + blk =3D blk_new_open(filename, NULL, options, + BDRV_O_RDWR | BDRV_O_RESIZE, errp); + if (!blk) { + error_prepend(errp, "Protocol driver '%s' does not support image " + "creation, and opening the image failed: ", + drv->format_name); + return -EINVAL; + } + + size =3D create_file_fallback_truncate(blk, size, errp); + if (size < 0) { + ret =3D size; + goto out; + } + + ret =3D create_file_fallback_zero_first_sector(blk, size, errp); + if (ret < 0) { + goto out; + } + + ret =3D 0; +out: + blk_unref(blk); + return ret; +} + +int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp) +{ + BlockDriver *drv; + drv =3D bdrv_find_protocol(filename, true, errp); if (drv =3D=3D NULL) { return -ENOENT; } =20 - ret =3D bdrv_create(drv, filename, opts, &local_err); - error_propagate(errp, local_err); - return ret; + if (drv->bdrv_co_create_opts) { + return bdrv_create(drv, filename, opts, errp); + } else { + return bdrv_create_file_fallback(filename, drv, opts, errp); + } } =20 /** @@ -1444,6 +1563,24 @@ QemuOptsList bdrv_runtime_opts =3D { }, }; =20 +static QemuOptsList fallback_create_opts =3D { + .name =3D "fallback-create-opts", + .head =3D QTAILQ_HEAD_INITIALIZER(fallback_create_opts.head), + .desc =3D { + { + .name =3D BLOCK_OPT_SIZE, + .type =3D QEMU_OPT_SIZE, + .help =3D "Virtual disk size" + }, + { + .name =3D BLOCK_OPT_PREALLOC, + .type =3D QEMU_OPT_STRING, + .help =3D "Preallocation mode (allowed values: off)" + }, + { /* end of list */ } + } +}; + /* * Common part for opening disk images and files * @@ -5772,15 +5909,13 @@ void bdrv_img_create(const char *filename, const ch= ar *fmt, return; } =20 - if (!proto_drv->create_opts) { - error_setg(errp, "Protocol driver '%s' does not support image crea= tion", - proto_drv->format_name); - return; - } - /* Create parameter list */ create_opts =3D qemu_opts_append(create_opts, drv->create_opts); - create_opts =3D qemu_opts_append(create_opts, proto_drv->create_opts); + if (proto_drv->create_opts) { + create_opts =3D qemu_opts_append(create_opts, proto_drv->create_op= ts); + } else { + create_opts =3D qemu_opts_append(create_opts, &fallback_create_opt= s); + } =20 opts =3D qemu_opts_create(create_opts, NULL, 0, &error_abort); =20 --=20 2.24.1