zfs-builds-mm/zfs-0.8.4/include/sys/space_map.h

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2020-07-19 16:21:53 +02:00
/*
* 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 */