From nobody Tue Nov 4 15:26:28 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.zohomail.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; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 153014500402310.252752351063009; Wed, 27 Jun 2018 17:16:44 -0700 (PDT) Received: from localhost ([::1]:33805 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fYKc7-0002ci-4x for importer@patchew.org; Wed, 27 Jun 2018 20:16:43 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57788) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fYKTw-0004eI-Ni for qemu-devel@nongnu.org; Wed, 27 Jun 2018 20:08:18 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fYKTv-000475-9E for qemu-devel@nongnu.org; Wed, 27 Jun 2018 20:08:16 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:55548 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fYKTn-0003wY-Ag; Wed, 27 Jun 2018 20:08:07 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id F39A04078B9E; Thu, 28 Jun 2018 00:08:06 +0000 (UTC) Received: from localhost (unknown [10.40.205.153]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7C7681C5B9; Thu, 28 Jun 2018 00:08:06 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Date: Thu, 28 Jun 2018 02:07:24 +0200 Message-Id: <20180628000745.4477-11-mreitz@redhat.com> In-Reply-To: <20180628000745.4477-1-mreitz@redhat.com> References: <20180628000745.4477-1-mreitz@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Thu, 28 Jun 2018 00:08:07 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Thu, 28 Jun 2018 00:08:07 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'mreitz@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH v9 10/31] block: bdrv_get_full_backing_filename_from_...'s ret. val. 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 , qemu-devel@nongnu.org, Max Reitz 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" Make bdrv_get_full_backing_filename_from_filename() return an allocated string instead of placing the result in a caller-provided buffer. Signed-off-by: Max Reitz Reviewed-by: Alberto Garcia --- include/block/block.h | 7 +++--- block.c | 53 ++++++++++++++++++++++++++++++------------- block/vmdk.c | 9 ++++---- qemu-img.c | 12 ++++------ 4 files changed, 48 insertions(+), 33 deletions(-) diff --git a/include/block/block.h b/include/block/block.h index f72ab30408..5f9c32b0f6 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -459,10 +459,9 @@ void bdrv_get_backing_filename(BlockDriverState *bs, char *filename, int filename_size); void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz, Error **errp); -void bdrv_get_full_backing_filename_from_filename(const char *backed, - const char *backing, - char *dest, size_t sz, - Error **errp); +char *bdrv_get_full_backing_filename_from_filename(const char *backed, + const char *backing, + Error **errp); =20 int path_has_protocol(const char *path); int path_is_absolute(const char *path); diff --git a/block.c b/block.c index be0a8475aa..fbec6680c8 100644 --- a/block.c +++ b/block.c @@ -293,20 +293,29 @@ int bdrv_set_read_only(BlockDriverState *bs, bool rea= d_only, Error **errp) return 0; } =20 -void bdrv_get_full_backing_filename_from_filename(const char *backed, - const char *backing, - char *dest, size_t sz, - Error **errp) +/* + * If @backing is empty, this function returns NULL without setting + * @errp. In all other cases, NULL will only be returned with @errp + * set. + * + * Therefore, a return value of NULL without @errp set means that + * there is no backing file; if @errp is set, there is one but its + * absolute filename cannot be generated. + */ +char *bdrv_get_full_backing_filename_from_filename(const char *backed, + const char *backing, + Error **errp) { - if (backing[0] =3D=3D '\0' || path_has_protocol(backing) || - path_is_absolute(backing)) - { - pstrcpy(dest, sz, backing); + if (backing[0] =3D=3D '\0') { + return NULL; + } else if (path_has_protocol(backing) || path_is_absolute(backing)) { + return g_strdup(backing); } else if (backed[0] =3D=3D '\0' || strstart(backed, "json:", NULL)) { error_setg(errp, "Cannot use relative backing file names for '%s'", backed); + return NULL; } else { - path_combine_deprecated(dest, sz, backed, backing); + return path_combine(backed, backing); } } =20 @@ -314,12 +323,24 @@ void bdrv_get_full_backing_filename(BlockDriverState = *bs, char *dest, size_t sz, Error **errp) { char *backed; + char *full_name; + Error *local_error =3D NULL; =20 bdrv_refresh_filename(bs); =20 backed =3D bs->exact_filename[0] ? bs->exact_filename : bs->filename; - bdrv_get_full_backing_filename_from_filename(backed, bs->backing_file, - dest, sz, errp); + + full_name =3D bdrv_get_full_backing_filename_from_filename(backed, + bs->backing_f= ile, + &local_error); + if (full_name) { + pstrcpy(dest, sz, full_name); + g_free(full_name); + } else if (local_error) { + error_propagate(errp, local_error); + } else if (sz > 0) { + *dest =3D '\0'; + } } =20 void bdrv_register(BlockDriver *bdrv) @@ -4802,17 +4823,17 @@ void bdrv_img_create(const char *filename, const ch= ar *fmt, size =3D qemu_opt_get_size(opts, BLOCK_OPT_SIZE, img_size); if (backing_file && !(flags & BDRV_O_NO_BACKING)) { BlockDriverState *bs; - char *full_backing =3D g_new0(char, PATH_MAX); + char *full_backing; int back_flags; QDict *backing_options =3D NULL; =20 - bdrv_get_full_backing_filename_from_filename(filename, backing_fil= e, - full_backing, PATH_MA= X, - &local_err); + full_backing =3D + bdrv_get_full_backing_filename_from_filename(filename, backing= _file, + &local_err); if (local_err) { - g_free(full_backing); goto out; } + assert(full_backing); =20 /* backing files always opened read-only */ back_flags =3D flags; diff --git a/block/vmdk.c b/block/vmdk.c index bec4a222e3..de8580042c 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -2022,16 +2022,15 @@ static int coroutine_fn vmdk_co_create_opts(const c= har *filename, QemuOpts *opts } if (backing_file) { BlockBackend *blk; - char *full_backing =3D g_new0(char, PATH_MAX); - bdrv_get_full_backing_filename_from_filename(filename, backing_fil= e, - full_backing, PATH_MA= X, - &local_err); + char *full_backing =3D + bdrv_get_full_backing_filename_from_filename(filename, backing= _file, + &local_err); if (local_err) { - g_free(full_backing); error_propagate(errp, local_err); ret =3D -ENOENT; goto exit; } + assert(full_backing); =20 blk =3D blk_new_open(full_backing, NULL, NULL, BDRV_O_NO_BACKING, errp); diff --git a/qemu-img.c b/qemu-img.c index e1a506f7f6..496bc6b756 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -3283,18 +3283,14 @@ static int img_rebase(int argc, char **argv) =20 overlay_filename =3D bs->exact_filename[0] ? bs->exact_filename : bs->filename; - out_real_path =3D g_malloc(PATH_MAX); - - bdrv_get_full_backing_filename_from_filename(overlay_filename, - out_baseimg, - out_real_path, - PATH_MAX, - &local_err); + out_real_path =3D + bdrv_get_full_backing_filename_from_filename(overlay_filen= ame, + out_baseimg, + &local_err); if (local_err) { error_reportf_err(local_err, "Could not resolve backing filename: "); ret =3D -1; - g_free(out_real_path); goto out; } =20 --=20 2.17.1