sheepdog: Add trivial backing_fmt support

Sheepdog already requires that if backing_file is present, that it be
another sheepdog image (see sd_co_create).  Meanwhile, we want to move
towards always being explicit about the backing format for other
drivers where it matters.  So for convenience, make qemu-img create -F
sheepdog work, while rejecting all other explicit formats (note that
this is only for QemuOpts usage; there is no change to the QAPI to
allow a format through -blockdev).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200706203954.341758-4-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Eric Blake 2020-07-06 15:39:47 -05:00 committed by Kevin Wolf
parent 25956af3fe
commit 80fa43e7df

View File

@ -2151,13 +2151,21 @@ static int coroutine_fn sd_co_create_opts(BlockDriver *drv,
Error **errp)
{
BlockdevCreateOptions *create_options = NULL;
QDict *qdict, *location_qdict;
QDict *qdict = NULL, *location_qdict;
Visitor *v;
char *redundancy;
char *redundancy = NULL;
Error *local_err = NULL;
int ret;
char *backing_fmt = NULL;
redundancy = qemu_opt_get_del(opts, BLOCK_OPT_REDUNDANCY);
backing_fmt = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FMT);
if (backing_fmt && strcmp(backing_fmt, "sheepdog") != 0) {
error_setg(errp, "backing_file must be a sheepdog image");
ret = -EINVAL;
goto fail;
}
qdict = qemu_opts_to_qdict(opts, NULL);
qdict_put_str(qdict, "driver", "sheepdog");
@ -2220,6 +2228,7 @@ fail:
qapi_free_BlockdevCreateOptions(create_options);
qobject_unref(qdict);
g_free(redundancy);
g_free(backing_fmt);
return ret;
}
@ -3177,6 +3186,11 @@ static QemuOptsList sd_create_opts = {
.type = QEMU_OPT_STRING,
.help = "File name of a base image"
},
{
.name = BLOCK_OPT_BACKING_FMT,
.type = QEMU_OPT_STRING,
.help = "Must be 'sheepdog' if present",
},
{
.name = BLOCK_OPT_PREALLOC,
.type = QEMU_OPT_STRING,