[mirror_zfs.git] / include / 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) 2013 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(sm)			\
	(sizeof ((sm)->sm_phys->smp_histogram) /	\
	sizeof ((sm)->sm_phys->smp_histogram[0]))

/*
 * 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 {
	uint64_t	smp_object;	/* on-disk space map object */
	uint64_t	smp_objsize;	/* size of the object */
	uint64_t	smp_alloc;	/* space allocated from the map */
	uint64_t	smp_pad[5];	/* reserved */

	/*
	 * 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[32]; /* histogram of free space */
} 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.
 */
typedef struct space_map {
	uint64_t	sm_start;	/* start of map */
	uint64_t	sm_size;	/* size of map */
	uint8_t		sm_shift;	/* unit shift */
	uint64_t	sm_length;	/* synced length */
	uint64_t	sm_alloc;	/* synced space allocated */
	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 */
	kmutex_t	*sm_lock;	/* pointer to lock that protects map */
} space_map_t;

/*
 * debug entry
 *
 *    1      3         10                     50
 *  ,---+--------+------------+---------------------------------.
 *  | 1 | action |  syncpass  |        txg (lower bits)         |
 *  `---+--------+------------+---------------------------------'
 *   63  62    60 59        50 49                               0
 *
 *
 * non-debug entry
 *
 *    1               47                   1           15
 *  ,-----------------------------------------------------------.
 *  | 0 |   offset (sm_shift units)    | type |       run       |
 *  `-----------------------------------------------------------'
 *   63  62                          17   16   15               0
 */

/* All this stuff takes and returns bytes */
#define	SM_RUN_DECODE(x)	(BF64_DECODE(x, 0, 15) + 1)
#define	SM_RUN_ENCODE(x)	BF64_ENCODE((x) - 1, 0, 15)
#define	SM_TYPE_DECODE(x)	BF64_DECODE(x, 15, 1)
#define	SM_TYPE_ENCODE(x)	BF64_ENCODE(x, 15, 1)
#define	SM_OFFSET_DECODE(x)	BF64_DECODE(x, 16, 47)
#define	SM_OFFSET_ENCODE(x)	BF64_ENCODE(x, 16, 47)
#define	SM_DEBUG_DECODE(x)	BF64_DECODE(x, 63, 1)
#define	SM_DEBUG_ENCODE(x)	BF64_ENCODE(x, 63, 1)

#define	SM_DEBUG_ACTION_DECODE(x)	BF64_DECODE(x, 60, 3)
#define	SM_DEBUG_ACTION_ENCODE(x)	BF64_ENCODE(x, 60, 3)

#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_RUN_MAX			SM_RUN_DECODE(~0ULL)

typedef enum {
	SM_ALLOC,
	SM_FREE
} maptype_t;

/*
 * The data for a given space map can be kept on blocks of any size.
 * Larger blocks entail fewer i/o operations, but they also cause the
 * DMU to keep more data in-core, and also to waste more i/o bandwidth
 * when only a few blocks have changed since the last transaction group.
 * Rather than having a fixed block size for all space maps the block size
 * can adjust as needed (see space_map_max_blksz). Set the initial block
 * size for the space map to 4k.
 */
#define	SPACE_MAP_INITIAL_BLOCKSIZE	(1ULL << 12)

int space_map_load(space_map_t *sm, range_tree_t *rt, maptype_t maptype);

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);

void space_map_update(space_map_t *sm);

uint64_t space_map_object(space_map_t *sm);
uint64_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,
    dmu_tx_t *tx);
void space_map_truncate(space_map_t *sm, dmu_tx_t *tx);
uint64_t space_map_alloc(objset_t *os, dmu_tx_t *tx);
void space_map_free(space_map_t *sm, 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, kmutex_t *lp);
void space_map_close(space_map_t *sm);

int64_t space_map_alloc_delta(space_map_t *sm);

#ifdef	__cplusplus
}
#endif

#endif	/* _SYS_SPACE_MAP_H */
Commit	Line	Data
34dc7c2f BB	1	/*
	2	* CDDL HEADER START
	3	*
	4	* The contents of this file are subject to the terms of the
	5	* Common Development and Distribution License (the "License").
	6	* You may not use this file except in compliance with the License.
	7	*
	8	* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
	9	* or http://www.opensolaris.org/os/licensing.
	10	* See the License for the specific language governing permissions
	11	* and limitations under the License.
	12	*
	13	* When distributing Covered Code, include this CDDL HEADER in each
	14	* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
	15	* If applicable, add the following below this CDDL HEADER, with the
	16	* fields enclosed by brackets "[]" replaced with your own identifying
	17	* information: Portions Copyright [yyyy] [name of copyright owner]
	18	*
	19	* CDDL HEADER END
	20	*/
	21	/*
9babb374	22	* Copyright 2009 Sun Microsystems, Inc. All rights reserved.
34dc7c2f BB	23	* Use is subject to license terms.
	24	*/
	25
55d85d5a	26	/*
93cf2076	27	* Copyright (c) 2013 by Delphix. All rights reserved.
55d85d5a GW	28	*/
55d85d5a GW	29
34dc7c2f BB	30	#ifndef _SYS_SPACE_MAP_H
	31	#define _SYS_SPACE_MAP_H
	32
34dc7c2f	33	#include <sys/avl.h>
93cf2076	34	#include <sys/range_tree.h>
34dc7c2f BB	35	#include <sys/dmu.h>
	36
	37	#ifdef __cplusplus
	38	extern "C" {
	39	#endif
	40
93cf2076 GW	41	/*
	42	* The size of the space map object has increased to include a histogram.
	43	* The SPACE_MAP_SIZE_V0 designates the original size and is used to
	44	* maintain backward compatibility.
	45	*/
	46	#define SPACE_MAP_SIZE_V0 (3 * sizeof (uint64_t))
	47	#define SPACE_MAP_HISTOGRAM_SIZE(sm) \
	48	(sizeof ((sm)->sm_phys->smp_histogram) / \
	49	sizeof ((sm)->sm_phys->smp_histogram[0]))
	50
	51	/*
	52	* The space_map_phys is the on-disk representation of the space map.
	53	* Consumers of space maps should never reference any of the members of this
	54	* structure directly. These members may only be updated in syncing context.
	55	*
	56	* Note the smp_object is no longer used but remains in the structure
	57	* for backward compatibility.
	58	*/
	59	typedef struct space_map_phys {
	60	uint64_t smp_object; /* on-disk space map object */
	61	uint64_t smp_objsize; /* size of the object */
	62	uint64_t smp_alloc; /* space allocated from the map */
	63	uint64_t smp_pad[5]; /* reserved */
	64
	65	/*
	66	* The smp_histogram maintains a histogram of free regions. Each
	67	* bucket, smp_histogram[i], contains the number of free regions
	68	* whose size is:
	69	* 2^(i+sm_shift) <= size of free region in bytes < 2^(i+sm_shift+1)
	70	*/
	71	uint64_t smp_histogram[32]; /* histogram of free space */
	72	} space_map_phys_t;
34dc7c2f	73
93cf2076 GW	74	/*
	75	* The space map object defines a region of space, its size, how much is
	76	* allocated, and the on-disk object that stores this information.
	77	* Consumers of space maps may only access the members of this structure.
	78	*/
34dc7c2f	79	typedef struct space_map {
34dc7c2f BB	80	uint64_t sm_start; /* start of map */
	81	uint64_t sm_size; /* size of map */
	82	uint8_t sm_shift; /* unit shift */
93cf2076 GW	83	uint64_t sm_length; /* synced length */
	84	uint64_t sm_alloc; /* synced space allocated */
	85	objset_t sm_os; / objset for this map */
	86	uint64_t sm_object; /* object id for this map */
	87	uint32_t sm_blksz; /* block size for space map */
	88	dmu_buf_t sm_dbuf; / space_map_phys_t dbuf */
	89	space_map_phys_t sm_phys; / on-disk space map */
34dc7c2f BB	90	kmutex_t sm_lock; / pointer to lock that protects map */
	91	} space_map_t;
	92
34dc7c2f BB	93	/*
	94	* debug entry
	95	*
	96	* 1 3 10 50
	97	* ,---+--------+------------+---------------------------------.
	98	* \| 1 \| action \| syncpass \| txg (lower bits) \|
	99	* `---+--------+------------+---------------------------------'
	100	* 63 62 60 59 50 49 0
	101	*
	102	*
34dc7c2f BB	103	* non-debug entry
	104	*
	105	* 1 47 1 15
	106	* ,-----------------------------------------------------------.
	107	* \| 0 \| offset (sm_shift units) \| type \| run \|
	108	* `-----------------------------------------------------------'
	109	* 63 62 17 16 15 0
	110	*/
	111
	112	/* All this stuff takes and returns bytes */
	113	#define SM_RUN_DECODE(x) (BF64_DECODE(x, 0, 15) + 1)
	114	#define SM_RUN_ENCODE(x) BF64_ENCODE((x) - 1, 0, 15)
	115	#define SM_TYPE_DECODE(x) BF64_DECODE(x, 15, 1)
	116	#define SM_TYPE_ENCODE(x) BF64_ENCODE(x, 15, 1)
	117	#define SM_OFFSET_DECODE(x) BF64_DECODE(x, 16, 47)
	118	#define SM_OFFSET_ENCODE(x) BF64_ENCODE(x, 16, 47)
	119	#define SM_DEBUG_DECODE(x) BF64_DECODE(x, 63, 1)
	120	#define SM_DEBUG_ENCODE(x) BF64_ENCODE(x, 63, 1)
	121
	122	#define SM_DEBUG_ACTION_DECODE(x) BF64_DECODE(x, 60, 3)
	123	#define SM_DEBUG_ACTION_ENCODE(x) BF64_ENCODE(x, 60, 3)
	124
	125	#define SM_DEBUG_SYNCPASS_DECODE(x) BF64_DECODE(x, 50, 10)
	126	#define SM_DEBUG_SYNCPASS_ENCODE(x) BF64_ENCODE(x, 50, 10)
	127
	128	#define SM_DEBUG_TXG_DECODE(x) BF64_DECODE(x, 0, 50)
	129	#define SM_DEBUG_TXG_ENCODE(x) BF64_ENCODE(x, 0, 50)
	130
	131	#define SM_RUN_MAX SM_RUN_DECODE(~0ULL)
	132
93cf2076 GW	133	typedef enum {
	134	SM_ALLOC,
	135	SM_FREE
	136	} maptype_t;
34dc7c2f BB	137
	138	/*
	139	* The data for a given space map can be kept on blocks of any size.
	140	* Larger blocks entail fewer i/o operations, but they also cause the
	141	* DMU to keep more data in-core, and also to waste more i/o bandwidth
	142	* when only a few blocks have changed since the last transaction group.
93cf2076 GW	143	* Rather than having a fixed block size for all space maps the block size
	144	* can adjust as needed (see space_map_max_blksz). Set the initial block
	145	* size for the space map to 4k.
34dc7c2f	146	*/
93cf2076 GW	147	#define SPACE_MAP_INITIAL_BLOCKSIZE (1ULL << 12)
	148
	149	int space_map_load(space_map_t sm, range_tree_t rt, maptype_t maptype);
	150
	151	void space_map_histogram_clear(space_map_t *sm);
	152	void space_map_histogram_add(space_map_t sm, range_tree_t rt,
	153	dmu_tx_t *tx);
	154
	155	void space_map_update(space_map_t *sm);
	156
	157	uint64_t space_map_object(space_map_t *sm);
	158	uint64_t space_map_allocated(space_map_t *sm);
	159	uint64_t space_map_length(space_map_t *sm);
	160
	161	void space_map_write(space_map_t sm, range_tree_t rt, maptype_t maptype,
	162	dmu_tx_t *tx);
	163	void space_map_truncate(space_map_t sm, dmu_tx_t tx);
	164	uint64_t space_map_alloc(objset_t os, dmu_tx_t tx);
	165	void space_map_free(space_map_t sm, dmu_tx_t tx);
	166
	167	int space_map_open(space_map_t *smp, objset_t os, uint64_t object,
	168	uint64_t start, uint64_t size, uint8_t shift, kmutex_t *lp);
	169	void space_map_close(space_map_t *sm);
	170
	171	int64_t space_map_alloc_delta(space_map_t *sm);
fb5f0bc8	172
34dc7c2f BB	173	#ifdef __cplusplus
	174	}
	175	#endif
	176
	177	#endif /* _SYS_SPACE_MAP_H */