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Diffstat (limited to 'include/sys/space_map.h')
| -rw-r--r-- | include/sys/space_map.h | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/include/sys/space_map.h b/include/sys/space_map.h new file mode 100644 index 000000000000..cb81e710bd1e --- /dev/null +++ b/include/sys/space_map.h @@ -0,0 +1,246 @@ +/* + * 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, 2019 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) + * + * Note that, if log space map feature is enabled, histograms of + * space maps that belong to metaslabs will take into account any + * unflushed changes for their metaslabs, even though the actual + * space map doesn't have entries for these changes. + */ + 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 */ + + /* + * The following fields are not part of the actual space map entry + * on-disk and they are populated with the values from the debug + * entry most recently visited starting from the beginning to the + * end of the space map. + */ + uint64_t sme_txg; + uint64_t sme_sync_pass; +} 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); +uint64_t space_map_entries(space_map_t *sm, range_tree_t *rt); +uint64_t space_map_nblocks(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 */ |