From c2ac1bee92ddb6f76ca9d43a1a6be9bc8e6221ca Mon Sep 17 00:00:00 2001
From: Petr Rockai <prokai@redhat.com>
Date: Fri, 13 May 2011 08:17:26 +0000
Subject: [PATCH] First go at the lvmetad client-side interface.

---
 daemons/lvmetad/lvmetad-client.h | 81 ++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 daemons/lvmetad/lvmetad-client.h

diff --git a/daemons/lvmetad/lvmetad-client.h b/daemons/lvmetad/lvmetad-client.h
new file mode 100644
index 000000000..3282dab81
--- /dev/null
+++ b/daemons/lvmetad/lvmetad-client.h
@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2011 Red Hat, Inc. All rights reserved.
+ *
+ * This file is part of LVM2.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU Lesser General Public License v.2.1.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#ifndef _LVM_LVMETAD_CLIENT_H
+#define _LVM_LVMETAD_CLIENT_H
+
+#include "daemon-client.h"
+
+/* Different types of replies we may get from lvmetad. */
+
+typedef struct {
+	daemon_reply r;
+	const char **uuids; /* NULL terminated array */
+} lvmetad_uuidlist;
+
+typedef struct {
+	daemon_reply r;
+	struct config_tree *cft;
+} lvmetad_vg;
+
+static inline daemon_handle lvmetad_open();
+static inline void lvmetad_close(daemon_handle h);
+
+/* Get a list of VG UUIDs that match a given VG name. */
+lvmetad_uuidlist lvmetad_lookup_vgname(daemon_handle h, const char *name);
+
+/* Get the metadata of a single VG, identified by UUID. */
+lvmetad_vg lvmetad_get_vg(daemon_handle h, const char *uuid);
+
+/*
+ * Add and remove PVs on demand. Udev-driven systems will use this interface
+ * instead of scanning.
+ */
+daemon_reply lvmetad_add_pv(daemon_handle h, const char *pv_uuid, const char *mda_content);
+daemon_reply lvmetad_remove_pv(daemon_handle h, const char *pv_uuid);
+
+/* Trigger a full disk scan, throwing away all caches. XXX do we eventually want
+ * this? Probalby not yet, anyway.
+ *     daemon_reply lvmetad_rescan(daemon_handle h);
+ */
+
+/*
+ * Update the version of metadata of a volume group. The VG has to be locked for
+ * writing for this, and the VG metadata here has to match whatever has been
+ * written to the disk (under this lock). This initially avoids the requirement
+ * for lvmetad to write to disk (in later revisions, lvmetad_supersede_vg may
+ * also do the writing, or we probably add another function to do that).
+ */
+daemon_reply lvmetad_supersede_vg(daemon_handle h, struct volume_group *vg);
+
+/* Implementation of inline functions */
+
+static inline daemon_handle lvmetad_open()
+{
+	/* TODO configurable */
+	daemon_info lvmetad_info = {
+		.path = "lvmetad",
+		.socket = "/var/run/lvmetad.socket",
+		.autostart = 1
+	};
+
+	return daemon_open(lvmetad_info);
+}
+
+static inline void lvmetad_close(daemon_handle h)
+{
+	return daemon_close(h);
+}
+
+#endif