[PATCH v5 1/7] 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(a)redhat.com>
---
block/sheepdog.c | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/block/sheepdog.c b/block/sheepdog.c
index 59f7ebb1710f..8f558367d2d5 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -2163,13 +2163,21 @@ 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");
@@ -2234,6 +2242,7 @@ fail:
qapi_free_BlockdevCreateOptions(create_options);
qobject_unref(qdict);
g_free(redundancy);
+ g_free(backing_fmt);
return ret;
}
@@ -3191,6 +3200,11 @@ 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,
--
2.26.0.rc2