zfs/include/sys/space_map.h - backupdr - Git at Google

 /*
  * CDDL HEADER START
  *
  * The contents of this file are subject to the terms of the
  * Common Development and Distribution License (the "License").
  * You may not use this file except in compliance with the License.
  *
  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  * or http://www.opensolaris.org/os/licensing.
  * See the License for the specific language governing permissions
  * and limitations under the License.
  *
  * When distributing Covered Code, include this CDDL HEADER in each
  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  * If applicable, add the following below this CDDL HEADER, with the
  * fields enclosed by brackets "[]" replaced with your own identifying
  * information: Portions Copyright [yyyy] [name of copyright owner]
  *
  * CDDL HEADER END
  */
 /*
  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */

 /*
  * Copyright (c) 2012, 2018 by Delphix. All rights reserved.
  */

 #ifndef _SYS_SPACE_MAP_H
 #define	_SYS_SPACE_MAP_H

 #include <sys/avl.h>
 #include <sys/range_tree.h>
 #include <sys/dmu.h>

 #ifdef	__cplusplus
 extern "C" {
 #endif

 /*
  * The size of the space map object has increased to include a histogram.
  * The SPACE_MAP_SIZE_V0 designates the original size and is used to
  * maintain backward compatibility.
  */
 #define	SPACE_MAP_SIZE_V0	(3 * sizeof (uint64_t))
 #define	SPACE_MAP_HISTOGRAM_SIZE	32

 /*
  * The space_map_phys is the on-disk representation of the space map.
  * Consumers of space maps should never reference any of the members of this
  * structure directly. These members may only be updated in syncing context.
  *
  * Note the smp_object is no longer used but remains in the structure
  * for backward compatibility.
  */
 typedef struct space_map_phys {
 	/* object number: not needed but kept for backwards compatibility */
 	uint64_t	smp_object;

 	/* length of the object in bytes */
 	uint64_t	smp_length;

 	/* space allocated from the map */
 	int64_t		smp_alloc;

 	/* reserved */
 	uint64_t	smp_pad[5];

 	/*
 	 * The smp_histogram maintains a histogram of free regions. Each
 	 * bucket, smp_histogram[i], contains the number of free regions
 	 * whose size is:
 	 * 2^(i+sm_shift) <= size of free region in bytes < 2^(i+sm_shift+1)
 	 */
 	uint64_t	smp_histogram[SPACE_MAP_HISTOGRAM_SIZE];
 } space_map_phys_t;

 /*
  * The space map object defines a region of space, its size, how much is
  * allocated, and the on-disk object that stores this information.
  * Consumers of space maps may only access the members of this structure.
  *
  * Note: the space_map may not be accessed concurrently; consumers
  * must provide external locking if required.
  */
 typedef struct space_map {
 	uint64_t	sm_start;	/* start of map */
 	uint64_t	sm_size;	/* size of map */
 	uint8_t		sm_shift;	/* unit shift */
 	objset_t	*sm_os;		/* objset for this map */
 	uint64_t	sm_object;	/* object id for this map */
 	uint32_t	sm_blksz;	/* block size for space map */
 	dmu_buf_t	*sm_dbuf;	/* space_map_phys_t dbuf */
 	space_map_phys_t *sm_phys;	/* on-disk space map */
 } space_map_t;

 /*
  * debug entry
  *
  *     2     2        10                     50
  *  +-----+-----+------------+----------------------------------+
  *  | 1 0 | act |  syncpass  |        txg (lower bits)          |
  *  +-----+-----+------------+----------------------------------+
  *   63 62 61 60 59        50 49                                0
  *
  *
  * one-word entry
  *
  *    1               47                   1           15
  *  +-----------------------------------------------------------+
  *  | 0 |   offset (sm_shift units)    | type |       run       |
  *  +-----------------------------------------------------------+
  *   63  62                          16   15   14               0
  *
  *
  * two-word entry
  *
  *     2     2               36                      24
  *  +-----+-----+---------------------------+-------------------+
  *  | 1 1 | pad |            run            |       vdev        |
  *  +-----+-----+---------------------------+-------------------+
  *   63 62 61 60 59                       24 23                 0
  *
  *     1                            63
  *  +------+----------------------------------------------------+
  *  | type |                      offset                        |
  *  +------+----------------------------------------------------+
  *     63   62                                                  0
  *
  * Note that a two-word entry will not straddle a block boundary.
  * If necessary, the last word of a block will be padded with a
  * debug entry (with act = syncpass = txg = 0).
  */

 typedef enum {
 	SM_ALLOC,
 	SM_FREE
 } maptype_t;

 typedef struct space_map_entry {
 	maptype_t sme_type;
 	uint32_t sme_vdev;	/* max is 2^24-1; SM_NO_VDEVID if not present */
 	uint64_t sme_offset;	/* max is 2^63-1; units of sm_shift */
 	uint64_t sme_run;	/* max is 2^36; units of sm_shift */
 } space_map_entry_t;

 #define	SM_NO_VDEVID	(1 << SPA_VDEVBITS)

 /* one-word entry constants */
 #define	SM_DEBUG_PREFIX	2
 #define	SM_OFFSET_BITS	47
 #define	SM_RUN_BITS	15

 /* two-word entry constants */
 #define	SM2_PREFIX	3
 #define	SM2_OFFSET_BITS	63
 #define	SM2_RUN_BITS	36

 #define	SM_PREFIX_DECODE(x)	BF64_DECODE(x, 62, 2)
 #define	SM_PREFIX_ENCODE(x)	BF64_ENCODE(x, 62, 2)

 #define	SM_DEBUG_ACTION_DECODE(x)	BF64_DECODE(x, 60, 2)
 #define	SM_DEBUG_ACTION_ENCODE(x)	BF64_ENCODE(x, 60, 2)
 #define	SM_DEBUG_SYNCPASS_DECODE(x)	BF64_DECODE(x, 50, 10)
 #define	SM_DEBUG_SYNCPASS_ENCODE(x)	BF64_ENCODE(x, 50, 10)
 #define	SM_DEBUG_TXG_DECODE(x)		BF64_DECODE(x, 0, 50)
 #define	SM_DEBUG_TXG_ENCODE(x)		BF64_ENCODE(x, 0, 50)

 #define	SM_OFFSET_DECODE(x)	BF64_DECODE(x, 16, SM_OFFSET_BITS)
 #define	SM_OFFSET_ENCODE(x)	BF64_ENCODE(x, 16, SM_OFFSET_BITS)
 #define	SM_TYPE_DECODE(x)	BF64_DECODE(x, 15, 1)
 #define	SM_TYPE_ENCODE(x)	BF64_ENCODE(x, 15, 1)
 #define	SM_RUN_DECODE(x)	(BF64_DECODE(x, 0, SM_RUN_BITS) + 1)
 #define	SM_RUN_ENCODE(x)	BF64_ENCODE((x) - 1, 0, SM_RUN_BITS)
 #define	SM_RUN_MAX		SM_RUN_DECODE(~0ULL)
 #define	SM_OFFSET_MAX		SM_OFFSET_DECODE(~0ULL)

 #define	SM2_RUN_DECODE(x)	(BF64_DECODE(x, SPA_VDEVBITS, SM2_RUN_BITS) + 1)
 #define	SM2_RUN_ENCODE(x)	BF64_ENCODE((x) - 1, SPA_VDEVBITS, SM2_RUN_BITS)
 #define	SM2_VDEV_DECODE(x)	BF64_DECODE(x, 0, SPA_VDEVBITS)
 #define	SM2_VDEV_ENCODE(x)	BF64_ENCODE(x, 0, SPA_VDEVBITS)
 #define	SM2_TYPE_DECODE(x)	BF64_DECODE(x, SM2_OFFSET_BITS, 1)
 #define	SM2_TYPE_ENCODE(x)	BF64_ENCODE(x, SM2_OFFSET_BITS, 1)
 #define	SM2_OFFSET_DECODE(x)	BF64_DECODE(x, 0, SM2_OFFSET_BITS)
 #define	SM2_OFFSET_ENCODE(x)	BF64_ENCODE(x, 0, SM2_OFFSET_BITS)
 #define	SM2_RUN_MAX		SM2_RUN_DECODE(~0ULL)
 #define	SM2_OFFSET_MAX		SM2_OFFSET_DECODE(~0ULL)

 boolean_t sm_entry_is_debug(uint64_t e);
 boolean_t sm_entry_is_single_word(uint64_t e);
 boolean_t sm_entry_is_double_word(uint64_t e);

 typedef int (*sm_cb_t)(space_map_entry_t *sme, void *arg);

 int space_map_load(space_map_t *sm, range_tree_t *rt, maptype_t maptype);
 int space_map_load_length(space_map_t *sm, range_tree_t *rt, maptype_t maptype,
     uint64_t length);
 int space_map_iterate(space_map_t *sm, uint64_t length,
     sm_cb_t callback, void *arg);
 int space_map_incremental_destroy(space_map_t *sm, sm_cb_t callback, void *arg,
     dmu_tx_t *tx);

 boolean_t space_map_histogram_verify(space_map_t *sm, range_tree_t *rt);
 void space_map_histogram_clear(space_map_t *sm);
 void space_map_histogram_add(space_map_t *sm, range_tree_t *rt,
     dmu_tx_t *tx);

 uint64_t space_map_object(space_map_t *sm);
 int64_t space_map_allocated(space_map_t *sm);
 uint64_t space_map_length(space_map_t *sm);

 void space_map_write(space_map_t *sm, range_tree_t *rt, maptype_t maptype,
     uint64_t vdev_id, dmu_tx_t *tx);
 uint64_t space_map_estimate_optimal_size(space_map_t *sm, range_tree_t *rt,
     uint64_t vdev_id);
 void space_map_truncate(space_map_t *sm, int blocksize, dmu_tx_t *tx);
 uint64_t space_map_alloc(objset_t *os, int blocksize, dmu_tx_t *tx);
 void space_map_free(space_map_t *sm, dmu_tx_t *tx);
 void space_map_free_obj(objset_t *os, uint64_t smobj, dmu_tx_t *tx);

 int space_map_open(space_map_t **smp, objset_t *os, uint64_t object,
     uint64_t start, uint64_t size, uint8_t shift);
 void space_map_close(space_map_t *sm);

 #ifdef	__cplusplus
 }
 #endif

 #endif	/* _SYS_SPACE_MAP_H */
	/*
	* CDDL HEADER START
	*
	* The contents of this file are subject to the terms of the
	* Common Development and Distribution License (the "License").
	* You may not use this file except in compliance with the License.
	*
	* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
	* or http://www.opensolaris.org/os/licensing.
	* See the License for the specific language governing permissions
	* and limitations under the License.
	*
	* When distributing Covered Code, include this CDDL HEADER in each
	* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
	* If applicable, add the following below this CDDL HEADER, with the
	* fields enclosed by brackets "[]" replaced with your own identifying
	* information: Portions Copyright [yyyy] [name of copyright owner]
	*
	* CDDL HEADER END
	*/
	/*
	* Copyright 2009 Sun Microsystems, Inc. All rights reserved.
	* Use is subject to license terms.
	*/

	/*
	* Copyright (c) 2012, 2018 by Delphix. All rights reserved.
	*/

	#ifndef _SYS_SPACE_MAP_H
	#define _SYS_SPACE_MAP_H

	#include <sys/avl.h>
	#include <sys/range_tree.h>
	#include <sys/dmu.h>

	#ifdef __cplusplus
	extern "C" {
	#endif

	/*
	* The size of the space map object has increased to include a histogram.
	* The SPACE_MAP_SIZE_V0 designates the original size and is used to
	* maintain backward compatibility.
	*/
	#define SPACE_MAP_SIZE_V0 (3 * sizeof (uint64_t))
	#define SPACE_MAP_HISTOGRAM_SIZE 32

	/*
	* The space_map_phys is the on-disk representation of the space map.
	* Consumers of space maps should never reference any of the members of this
	* structure directly. These members may only be updated in syncing context.
	*
	* Note the smp_object is no longer used but remains in the structure
	* for backward compatibility.
	*/
	typedef struct space_map_phys {
	/* object number: not needed but kept for backwards compatibility */
	uint64_t smp_object;

	/* length of the object in bytes */
	uint64_t smp_length;

	/* space allocated from the map */
	int64_t smp_alloc;

	/* reserved */
	uint64_t smp_pad[5];

	/*
	* The smp_histogram maintains a histogram of free regions. Each
	* bucket, smp_histogram[i], contains the number of free regions
	* whose size is:
	* 2^(i+sm_shift) <= size of free region in bytes < 2^(i+sm_shift+1)
	*/
	uint64_t smp_histogram[SPACE_MAP_HISTOGRAM_SIZE];
	} space_map_phys_t;

	/*
	* The space map object defines a region of space, its size, how much is
	* allocated, and the on-disk object that stores this information.
	* Consumers of space maps may only access the members of this structure.
	*
	* Note: the space_map may not be accessed concurrently; consumers
	* must provide external locking if required.
	*/
	typedef struct space_map {
	uint64_t sm_start; /* start of map */
	uint64_t sm_size; /* size of map */
	uint8_t sm_shift; /* unit shift */
	objset_t sm_os; / objset for this map */
	uint64_t sm_object; /* object id for this map */
	uint32_t sm_blksz; /* block size for space map */
	dmu_buf_t sm_dbuf; / space_map_phys_t dbuf */
	space_map_phys_t sm_phys; / on-disk space map */
	} space_map_t;

	/*
	* debug entry
	*
	* 2 2 10 50
	* +-----+-----+------------+----------------------------------+
	* \| 1 0 \| act \| syncpass \| txg (lower bits) \|
	* +-----+-----+------------+----------------------------------+
	* 63 62 61 60 59 50 49 0
	*
	*
	* one-word entry
	*
	* 1 47 1 15
	* +-----------------------------------------------------------+
	* \| 0 \| offset (sm_shift units) \| type \| run \|
	* +-----------------------------------------------------------+
	* 63 62 16 15 14 0
	*
	*
	* two-word entry
	*
	* 2 2 36 24
	* +-----+-----+---------------------------+-------------------+
	* \| 1 1 \| pad \| run \| vdev \|
	* +-----+-----+---------------------------+-------------------+
	* 63 62 61 60 59 24 23 0
	*
	* 1 63
	* +------+----------------------------------------------------+
	* \| type \| offset \|
	* +------+----------------------------------------------------+
	* 63 62 0
	*
	* Note that a two-word entry will not straddle a block boundary.
	* If necessary, the last word of a block will be padded with a
	* debug entry (with act = syncpass = txg = 0).
	*/

	typedef enum {
	SM_ALLOC,
	SM_FREE
	} maptype_t;

	typedef struct space_map_entry {
	maptype_t sme_type;
	uint32_t sme_vdev; /* max is 2^24-1; SM_NO_VDEVID if not present */
	uint64_t sme_offset; /* max is 2^63-1; units of sm_shift */
	uint64_t sme_run; /* max is 2^36; units of sm_shift */
	} space_map_entry_t;

	#define SM_NO_VDEVID (1 << SPA_VDEVBITS)

	/* one-word entry constants */
	#define SM_DEBUG_PREFIX 2
	#define SM_OFFSET_BITS 47
	#define SM_RUN_BITS 15

	/* two-word entry constants */
	#define SM2_PREFIX 3
	#define SM2_OFFSET_BITS 63
	#define SM2_RUN_BITS 36

	#define SM_PREFIX_DECODE(x) BF64_DECODE(x, 62, 2)
	#define SM_PREFIX_ENCODE(x) BF64_ENCODE(x, 62, 2)

	#define SM_DEBUG_ACTION_DECODE(x) BF64_DECODE(x, 60, 2)
	#define SM_DEBUG_ACTION_ENCODE(x) BF64_ENCODE(x, 60, 2)
	#define SM_DEBUG_SYNCPASS_DECODE(x) BF64_DECODE(x, 50, 10)
	#define SM_DEBUG_SYNCPASS_ENCODE(x) BF64_ENCODE(x, 50, 10)
	#define SM_DEBUG_TXG_DECODE(x) BF64_DECODE(x, 0, 50)
	#define SM_DEBUG_TXG_ENCODE(x) BF64_ENCODE(x, 0, 50)

	#define SM_OFFSET_DECODE(x) BF64_DECODE(x, 16, SM_OFFSET_BITS)
	#define SM_OFFSET_ENCODE(x) BF64_ENCODE(x, 16, SM_OFFSET_BITS)
	#define SM_TYPE_DECODE(x) BF64_DECODE(x, 15, 1)
	#define SM_TYPE_ENCODE(x) BF64_ENCODE(x, 15, 1)
	#define SM_RUN_DECODE(x) (BF64_DECODE(x, 0, SM_RUN_BITS) + 1)
	#define SM_RUN_ENCODE(x) BF64_ENCODE((x) - 1, 0, SM_RUN_BITS)
	#define SM_RUN_MAX SM_RUN_DECODE(~0ULL)
	#define SM_OFFSET_MAX SM_OFFSET_DECODE(~0ULL)

	#define SM2_RUN_DECODE(x) (BF64_DECODE(x, SPA_VDEVBITS, SM2_RUN_BITS) + 1)
	#define SM2_RUN_ENCODE(x) BF64_ENCODE((x) - 1, SPA_VDEVBITS, SM2_RUN_BITS)
	#define SM2_VDEV_DECODE(x) BF64_DECODE(x, 0, SPA_VDEVBITS)
	#define SM2_VDEV_ENCODE(x) BF64_ENCODE(x, 0, SPA_VDEVBITS)
	#define SM2_TYPE_DECODE(x) BF64_DECODE(x, SM2_OFFSET_BITS, 1)
	#define SM2_TYPE_ENCODE(x) BF64_ENCODE(x, SM2_OFFSET_BITS, 1)
	#define SM2_OFFSET_DECODE(x) BF64_DECODE(x, 0, SM2_OFFSET_BITS)
	#define SM2_OFFSET_ENCODE(x) BF64_ENCODE(x, 0, SM2_OFFSET_BITS)
	#define SM2_RUN_MAX SM2_RUN_DECODE(~0ULL)
	#define SM2_OFFSET_MAX SM2_OFFSET_DECODE(~0ULL)

	boolean_t sm_entry_is_debug(uint64_t e);
	boolean_t sm_entry_is_single_word(uint64_t e);
	boolean_t sm_entry_is_double_word(uint64_t e);

	typedef int (sm_cb_t)(space_map_entry_t sme, void *arg);

	int space_map_load(space_map_t sm, range_tree_t rt, maptype_t maptype);
	int space_map_load_length(space_map_t sm, range_tree_t rt, maptype_t maptype,
	uint64_t length);
	int space_map_iterate(space_map_t *sm, uint64_t length,
	sm_cb_t callback, void *arg);
	int space_map_incremental_destroy(space_map_t sm, sm_cb_t callback, void arg,
	dmu_tx_t *tx);

	boolean_t space_map_histogram_verify(space_map_t sm, range_tree_t rt);
	void space_map_histogram_clear(space_map_t *sm);
	void space_map_histogram_add(space_map_t sm, range_tree_t rt,
	dmu_tx_t *tx);

	uint64_t space_map_object(space_map_t *sm);
	int64_t space_map_allocated(space_map_t *sm);
	uint64_t space_map_length(space_map_t *sm);

	void space_map_write(space_map_t sm, range_tree_t rt, maptype_t maptype,
	uint64_t vdev_id, dmu_tx_t *tx);
	uint64_t space_map_estimate_optimal_size(space_map_t sm, range_tree_t rt,
	uint64_t vdev_id);
	void space_map_truncate(space_map_t sm, int blocksize, dmu_tx_t tx);
	uint64_t space_map_alloc(objset_t os, int blocksize, dmu_tx_t tx);
	void space_map_free(space_map_t sm, dmu_tx_t tx);
	void space_map_free_obj(objset_t os, uint64_t smobj, dmu_tx_t tx);

	int space_map_open(space_map_t *smp, objset_t os, uint64_t object,
	uint64_t start, uint64_t size, uint8_t shift);
	void space_map_close(space_map_t *sm);

	#ifdef __cplusplus
	}
	#endif

	#endif /* _SYS_SPACE_MAP_H */