summaryrefslogtreecommitdiff
path: root/include/zfs/uberblock_impl.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/zfs/uberblock_impl.h')
-rw-r--r--include/zfs/uberblock_impl.h57
1 files changed, 57 insertions, 0 deletions
diff --git a/include/zfs/uberblock_impl.h b/include/zfs/uberblock_impl.h
new file mode 100644
index 0000000..806da95
--- /dev/null
+++ b/include/zfs/uberblock_impl.h
@@ -0,0 +1,57 @@
+/*
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 1999,2000,2001,2002,2003,2004 Free Software Foundation, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+/*
+ * Copyright 2007 Sun Microsystems, Inc. All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#ifndef _SYS_UBERBLOCK_IMPL_H
+#define _SYS_UBERBLOCK_IMPL_H
+
+#define UBMAX(a, b) ((a) > (b) ? (a) : (b))
+
+/*
+ * The uberblock version is incremented whenever an incompatible on-disk
+ * format change is made to the SPA, DMU, or ZAP.
+ *
+ * Note: the first two fields should never be moved. When a storage pool
+ * is opened, the uberblock must be read off the disk before the version
+ * can be checked. If the ub_version field is moved, we may not detect
+ * version mismatch. If the ub_magic field is moved, applications that
+ * expect the magic number in the first word won't work.
+ */
+#define UBERBLOCK_MAGIC 0x00bab10c /* oo-ba-bloc! */
+#define UBERBLOCK_SHIFT 10 /* up to 1K */
+
+typedef struct uberblock {
+ uint64_t ub_magic; /* UBERBLOCK_MAGIC */
+ uint64_t ub_version; /* ZFS_VERSION */
+ uint64_t ub_txg; /* txg of last sync */
+ uint64_t ub_guid_sum; /* sum of all vdev guids */
+ uint64_t ub_timestamp; /* UTC time of last sync */
+ blkptr_t ub_rootbp; /* MOS objset_phys_t */
+} uberblock_t;
+
+#define VDEV_UBERBLOCK_SHIFT(as) UBMAX(as, UBERBLOCK_SHIFT)
+#define UBERBLOCK_SIZE(as) (1ULL << VDEV_UBERBLOCK_SHIFT(as))
+
+/* Number of uberblocks that can fit in the ring at a given ashift */
+#define UBERBLOCK_COUNT(as) (VDEV_UBERBLOCK_RING >> VDEV_UBERBLOCK_SHIFT(as))
+
+#endif /* _SYS_UBERBLOCK_IMPL_H */