1 files changed, 63 insertions, 0 deletions
diff --git a/include/sys/mmp.h b/include/sys/mmp.h
new file mode 100644
index 000000000..4da612d6a
--- /dev/null
+++ b/include/sys/mmp.h
@@ -0,0 +1,63 @@
+/*
+ * CDDL HEADER START
+ *
+ * This file and its contents are supplied under the terms of the
+ * Common Development and Distribution License ("CDDL"), version 1.0.
+ * You may only use this file in accordance with the terms of version
+ * 1.0 of the CDDL.
+ *
+ * A full copy of the text of the CDDL should have accompanied this
+ * source.  A copy of the CDDL is also available via the Internet at
+ * http://www.illumos.org/license/CDDL.
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright (C) 2017 by Lawrence Livermore National Security, LLC.
+ */
+
+#ifndef _SYS_MMP_H
+#define	_SYS_MMP_H
+
+#include <sys/spa.h>
+#include <sys/zfs_context.h>
+#include <sys/uberblock_impl.h>
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+#define	MMP_MIN_INTERVAL		100	/* ms */
+#define	MMP_DEFAULT_INTERVAL		1000	/* ms */
+#define	MMP_DEFAULT_IMPORT_INTERVALS	10
+#define	MMP_DEFAULT_FAIL_INTERVALS	5
+
+typedef struct mmp_thread {
+	kmutex_t	mmp_thread_lock; /* protect thread mgmt fields */
+	kcondvar_t	mmp_thread_cv;
+	kthread_t	*mmp_thread;
+	uint8_t		mmp_thread_exiting;
+	kmutex_t	mmp_io_lock;	/* protect below */
+	hrtime_t	mmp_last_write;	/* last successful MMP write */
+	uint64_t	mmp_delay;	/* decaying avg ns between MMP writes */
+	uberblock_t	mmp_ub;		/* last ub written by sync */
+	zio_t		*mmp_zio_root;	/* root of mmp write zios */
+} mmp_thread_t;
+
+
+extern void mmp_init(struct spa *spa);
+extern void mmp_fini(struct spa *spa);
+extern void mmp_thread_start(struct spa *spa);
+extern void mmp_thread_stop(struct spa *spa);
+extern void mmp_update_uberblock(struct spa *spa, struct uberblock *ub);
+
+/* Global tuning */
+extern ulong_t zfs_multihost_interval;
+extern uint_t zfs_multihost_fail_intervals;
+extern uint_t zfs_multihost_import_intervals;
+
+#ifdef	__cplusplus
+}
+#endif
+
+#endif	/* _SYS_MMP_H */