From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33515) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gZ1ce-00077D-Nj for qemu-devel@nongnu.org; Mon, 17 Dec 2018 17:44:25 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gZ1cd-0006Cj-IA for qemu-devel@nongnu.org; Mon, 17 Dec 2018 17:44:24 -0500 From: Max Reitz Date: Mon, 17 Dec 2018 23:43:27 +0100 Message-Id: <20181217224348.14922-11-mreitz@redhat.com> In-Reply-To: <20181217224348.14922-1-mreitz@redhat.com> References: <20181217224348.14922-1-mreitz@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PATCH v12 10/31] block: bdrv_get_full_backing_filename_from_...'s ret. val. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: qemu-devel@nongnu.org, Max Reitz , Kevin Wolf , Alberto Garcia , Eric Blake 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 c69b08bef9..9dd573351b 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -487,10 +487,9 @@ 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 933a43c989..0cd4412725 100644 --- a/block.c +++ b/block.c @@ -312,20 +312,29 @@ fail: return -EACCES; } =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 @@ -333,12 +342,24 @@ void bdrv_get_full_backing_filename(BlockDriverStat= e *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_fil= e, - dest, sz, errp); + + full_name =3D bdrv_get_full_backing_filename_from_filename(backed, + bs->backing= _file, + &local_erro= r); + 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) @@ -4965,17 +4986,17 @@ void bdrv_img_create(const char *filename, const = char *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_f= ile, - full_backing, PATH_= MAX, - &local_err); + full_backing =3D + bdrv_get_full_backing_filename_from_filename(filename, backi= ng_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 3d3273e65b..b3fc3b9e12 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -2049,16 +2049,15 @@ static int coroutine_fn vmdk_co_create_opts(const= char *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_f= ile, - full_backing, PATH_= MAX, - &local_err); + char *full_backing =3D + bdrv_get_full_backing_filename_from_filename(filename, backi= ng_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 da14ec0bb5..cd81621554 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -3336,18 +3336,14 @@ static int img_rebase(int argc, char **argv) bdrv_refresh_filename(bs); overlay_filename =3D bs->exact_filename[0] ? bs->exact_filen= ame : bs->filename; - out_real_path =3D g_malloc(PATH_MAX); - - bdrv_get_full_backing_filename_from_filename(overlay_filenam= e, - out_baseimg, - out_real_path, - PATH_MAX, - &local_err); + out_real_path =3D + bdrv_get_full_backing_filename_from_filename(overlay_fil= ename, + 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 2.19.2