On 03/13/2018 08:47 AM, Eric Blake wrote:
On 03/12/2018 10:21 AM, Vladimir Sementsov-Ogievskiy wrote:
Minimal realization: only one extent in server answer is supported.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
---
+/* nbd_negotiate_meta_queries
+ * Handle NBD_OPT_LIST_META_CONTEXT and NBD_OPT_SET_META_CONTEXT
+ *
+ * @meta may be NULL, if caller isn't interested in selected contexts
(for
+ * NBD_OPT_LIST_META_CONTEXT)
+ *
+ * Return -errno on I/O error, 0 if option was completely handled by
+ * sending a reply about inconsistent lengths, or 1 on success. */
Comment is wrong - this function never returns 1 (nor should it, as
nbd_negotiate_options() expects a return of 1 only from NBD_OPT_ABORT).
+static int nbd_negotiate_meta_queries(NBDClient *client,
+ NBDExportMetaContexts *meta,
Error **errp)
+{
+ int ret;
+ NBDExport *exp;
+ NBDExportMetaContexts local_meta;
+ uint32_t nb_queries;
+ int i;
+
+ assert(client->structured_reply);
Perhaps worth a comment that this is safe because we already filtered it
out at the caller.
+
+ if (!meta) {
+ meta = &local_meta;
+ }
Or, we could check here, and even base our decision on whether to change
'meta' due to client->opt...
@@ -856,6 +1064,22 @@ static int nbd_negotiate_options(NBDClient
*client, uint16_t myflags,
}
break;
+ case NBD_OPT_LIST_META_CONTEXT:
+ case NBD_OPT_SET_META_CONTEXT:
+ if (!client->structured_reply) {
+ ret = nbd_opt_invalid(
+ client, errp,
+ "request option '%s' when structured reply "
+ "is not negotiated",
nbd_opt_lookup(option));
+ } else if (option == NBD_OPT_LIST_META_CONTEXT) {
+ ret = nbd_negotiate_meta_queries(client, NULL,
errp);
+ } else {
+ ret = nbd_negotiate_meta_queries(client,
+
&client->export_meta,
+ errp);
+ }
Then here, we just do a single ret = nbd_negotiate_meta_queries().
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org
