xref: /openbmc/u-boot/include/zfs/uberblock_impl.h (revision 83d290c56fab2d38cd1ab4c4cc7099559c1d5046)
1*83d290c5STom Rini /* SPDX-License-Identifier: GPL-2.0+ */
24d3c95f5SJorgen Lundman /*
34d3c95f5SJorgen Lundman  *  GRUB  --  GRand Unified Bootloader
44d3c95f5SJorgen Lundman  *  Copyright (C) 1999,2000,2001,2002,2003,2004  Free Software Foundation, Inc.
54d3c95f5SJorgen Lundman  */
64d3c95f5SJorgen Lundman /*
74d3c95f5SJorgen Lundman  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
84d3c95f5SJorgen Lundman  * Use is subject to license terms.
94d3c95f5SJorgen Lundman  */
104d3c95f5SJorgen Lundman 
114d3c95f5SJorgen Lundman #ifndef _SYS_UBERBLOCK_IMPL_H
124d3c95f5SJorgen Lundman #define	_SYS_UBERBLOCK_IMPL_H
134d3c95f5SJorgen Lundman 
144d3c95f5SJorgen Lundman #define UBMAX(a, b) ((a) > (b) ? (a) : (b))
154d3c95f5SJorgen Lundman 
164d3c95f5SJorgen Lundman /*
174d3c95f5SJorgen Lundman  * The uberblock version is incremented whenever an incompatible on-disk
184d3c95f5SJorgen Lundman  * format change is made to the SPA, DMU, or ZAP.
194d3c95f5SJorgen Lundman  *
204d3c95f5SJorgen Lundman  * Note: the first two fields should never be moved.  When a storage pool
214d3c95f5SJorgen Lundman  * is opened, the uberblock must be read off the disk before the version
224d3c95f5SJorgen Lundman  * can be checked.	If the ub_version field is moved, we may not detect
234d3c95f5SJorgen Lundman  * version mismatch.  If the ub_magic field is moved, applications that
244d3c95f5SJorgen Lundman  * expect the magic number in the first word won't work.
254d3c95f5SJorgen Lundman  */
264d3c95f5SJorgen Lundman #define	UBERBLOCK_MAGIC		0x00bab10c		/* oo-ba-bloc!	*/
274d3c95f5SJorgen Lundman #define	UBERBLOCK_SHIFT		10			/* up to 1K	*/
284d3c95f5SJorgen Lundman 
294d3c95f5SJorgen Lundman typedef struct uberblock {
304d3c95f5SJorgen Lundman 	uint64_t	ub_magic;	/* UBERBLOCK_MAGIC		*/
314d3c95f5SJorgen Lundman 	uint64_t	ub_version;	/* ZFS_VERSION			*/
324d3c95f5SJorgen Lundman 	uint64_t	ub_txg;		/* txg of last sync		*/
334d3c95f5SJorgen Lundman 	uint64_t	ub_guid_sum;	/* sum of all vdev guids	*/
344d3c95f5SJorgen Lundman 	uint64_t	ub_timestamp;	/* UTC time of last sync	*/
354d3c95f5SJorgen Lundman 	blkptr_t	ub_rootbp;	/* MOS objset_phys_t		*/
364d3c95f5SJorgen Lundman } uberblock_t;
374d3c95f5SJorgen Lundman 
384d3c95f5SJorgen Lundman #define	VDEV_UBERBLOCK_SHIFT(as)	UBMAX(as, UBERBLOCK_SHIFT)
394d3c95f5SJorgen Lundman #define	UBERBLOCK_SIZE(as)		(1ULL << VDEV_UBERBLOCK_SHIFT(as))
404d3c95f5SJorgen Lundman 
414d3c95f5SJorgen Lundman /* Number of uberblocks that can fit in the ring at a given ashift */
424d3c95f5SJorgen Lundman #define UBERBLOCK_COUNT(as) (VDEV_UBERBLOCK_RING >> VDEV_UBERBLOCK_SHIFT(as))
434d3c95f5SJorgen Lundman 
444d3c95f5SJorgen Lundman #endif	/* _SYS_UBERBLOCK_IMPL_H */
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