zfs/include/sys/ddt_impl.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 https://opensource.org/licenses/CDDL-1.0.
 * 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 (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2016 by Delphix. All rights reserved.
 * Copyright (c) 2023, Klara Inc.
 */

#ifndef _SYS_DDT_IMPL_H
#define	_SYS_DDT_IMPL_H

#include <sys/ddt.h>
#include <sys/bitops.h>

#ifdef	__cplusplus
extern "C" {
#endif

/* DDT version numbers */
#define	DDT_VERSION_LEGACY		(0)
#define	DDT_VERSION_FDT			(1)

/* Dummy version to signal that configure is still necessary */
#define	DDT_VERSION_UNCONFIGURED	(UINT64_MAX)

/* Names of interesting objects in the DDT root dir */
#define	DDT_DIR_VERSION		"version"
#define	DDT_DIR_FLAGS		"flags"

/* Fill a lightweight entry from a live entry. */
#define	DDT_ENTRY_TO_LIGHTWEIGHT(ddt, dde, ddlwe) do {			\
	memset((ddlwe), 0, sizeof (*ddlwe));				\
	(ddlwe)->ddlwe_key = (dde)->dde_key;				\
	(ddlwe)->ddlwe_type = (dde)->dde_type;				\
	(ddlwe)->ddlwe_class = (dde)->dde_class;			\
	memcpy(&(ddlwe)->ddlwe_phys, (dde)->dde_phys, DDT_PHYS_SIZE(ddt)); \
} while (0)

#define	DDT_LOG_ENTRY_TO_LIGHTWEIGHT(ddt, ddle, ddlwe) do {             \
	memset((ddlwe), 0, sizeof (*ddlwe));                            \
	(ddlwe)->ddlwe_key = (ddle)->ddle_key;                          \
	(ddlwe)->ddlwe_type = (ddle)->ddle_type;                        \
	(ddlwe)->ddlwe_class = (ddle)->ddle_class;                      \
	memcpy(&(ddlwe)->ddlwe_phys, (ddle)->ddle_phys, DDT_PHYS_SIZE(ddt)); \
} while (0)

/*
 * An entry on the log tree. These are "frozen", and a record of what's in
 * the on-disk log. They can't be used in place, but can be "loaded" back into
 * the live tree.
 */
typedef struct {
	ddt_key_t	ddle_key;	/* ddt_log_tree key */
	avl_node_t	ddle_node;	/* ddt_log_tree node */

	ddt_type_t	ddle_type;	/* storage type */
	ddt_class_t	ddle_class;	/* storage class */

	/* extra allocation for flat/trad phys */
	ddt_univ_phys_t	ddle_phys[];
} ddt_log_entry_t;

/* On-disk log record types. */
typedef enum {
	DLR_INVALID	= 0,	/* end of block marker */
	DLR_ENTRY	= 1,	/* an entry to add or replace in the log tree */
} ddt_log_record_type_t;

/* On-disk log record header. */
typedef struct {
	/*
	 * dlr_info is a packed u64, use the DLR_GET/DLR_SET macros below to
	 * access it.
	 *
	 * bits 0-7:    record type (ddt_log_record_type_t)
	 * bits 8-15:  length of record header+payload
	 * bits 16-47:  reserved, all zero
	 * bits 48-55:   if type==DLR_ENTRY, storage type (ddt_type)
	 *                otherwise all zero
	 * bits 56-63:  if type==DLR_ENTRY, storage class (ddt_class)
	 *                otherwise all zero
	 */
	uint64_t	dlr_info;
	uint8_t		dlr_payload[];
} ddt_log_record_t;

#define	DLR_GET_TYPE(dlr)		BF64_GET((dlr)->dlr_info, 0, 8)
#define	DLR_SET_TYPE(dlr, v)		BF64_SET((dlr)->dlr_info, 0, 8, v)
#define	DLR_GET_RECLEN(dlr)		BF64_GET((dlr)->dlr_info, 8, 16)
#define	DLR_SET_RECLEN(dlr, v)		BF64_SET((dlr)->dlr_info, 8, 16, v)
#define	DLR_GET_ENTRY_TYPE(dlr)		BF64_GET((dlr)->dlr_info, 48, 8)
#define	DLR_SET_ENTRY_TYPE(dlr, v)	BF64_SET((dlr)->dlr_info, 48, 8, v)
#define	DLR_GET_ENTRY_CLASS(dlr)	BF64_GET((dlr)->dlr_info, 56, 8)
#define	DLR_SET_ENTRY_CLASS(dlr, v)	BF64_SET((dlr)->dlr_info, 56, 8, v)

/* Payload for DLR_ENTRY. */
typedef struct {
	ddt_key_t	dlre_key;
	ddt_univ_phys_t	dlre_phys[];
} ddt_log_record_entry_t;

/* Log flags (ddl_flags, dlh_flags) */
#define	DDL_FLAG_FLUSHING	(1 << 0)	/* this log is being flushed */
#define	DDL_FLAG_CHECKPOINT	(1 << 1)	/* header has a checkpoint */

/* On-disk log header, stored in the bonus buffer. */
typedef struct {
	/*
	 * dlh_info is a packed u64, use the DLH_GET/DLH_SET macros below to
	 * access it.
	 *
	 * bits 0-7:   log version
	 * bits 8-15:  log flags
	 * bits 16-63: reserved, all zero
	 */
	uint64_t	dlh_info;

	uint64_t	dlh_length;	/* log size in bytes */
	uint64_t	dlh_first_txg;	/* txg this log went active */
	ddt_key_t	dlh_checkpoint;	/* last checkpoint */
} ddt_log_header_t;

#define	DLH_GET_VERSION(dlh)	BF64_GET((dlh)->dlh_info, 0, 8)
#define	DLH_SET_VERSION(dlh, v)	BF64_SET((dlh)->dlh_info, 0, 8, v)
#define	DLH_GET_FLAGS(dlh)	BF64_GET((dlh)->dlh_info, 8, 8)
#define	DLH_SET_FLAGS(dlh, v)	BF64_SET((dlh)->dlh_info, 8, 8, v)

/* DDT log update state */
typedef struct {
	dmu_tx_t	*dlu_tx;	/* tx the update is being applied to */
	dnode_t		*dlu_dn;	/* log object dnode */
	dmu_buf_t	**dlu_dbp;	/* array of block buffer pointers */
	int		dlu_ndbp;	/* number of block buffer pointers */
	uint16_t	dlu_reclen;	/* cached length of record */
	uint64_t	dlu_block;	/* block for next entry */
	uint64_t	dlu_offset;	/* offset for next entry */
} ddt_log_update_t;

/*
 * Ops vector to access a specific DDT object type.
 */
typedef struct {
	char ddt_op_name[32];
	int (*ddt_op_create)(objset_t *os, uint64_t *object, dmu_tx_t *tx,
	    boolean_t prehash);
	int (*ddt_op_destroy)(objset_t *os, uint64_t object, dmu_tx_t *tx);
	int (*ddt_op_lookup)(objset_t *os, uint64_t object,
	    const ddt_key_t *ddk, void *phys, size_t psize);
	int (*ddt_op_contains)(objset_t *os, uint64_t object,
	    const ddt_key_t *ddk);
	void (*ddt_op_prefetch)(objset_t *os, uint64_t object,
	    const ddt_key_t *ddk);
	void (*ddt_op_prefetch_all)(objset_t *os, uint64_t object);
	int (*ddt_op_update)(objset_t *os, uint64_t object,
	    const ddt_key_t *ddk, const void *phys, size_t psize,
	    dmu_tx_t *tx);
	int (*ddt_op_remove)(objset_t *os, uint64_t object,
	    const ddt_key_t *ddk, dmu_tx_t *tx);
	int (*ddt_op_walk)(objset_t *os, uint64_t object, uint64_t *walk,
	    ddt_key_t *ddk, void *phys, size_t psize);
	int (*ddt_op_count)(objset_t *os, uint64_t object, uint64_t *count);
} ddt_ops_t;

extern const ddt_ops_t ddt_zap_ops;

/* Dedup log API */
extern void ddt_log_begin(ddt_t *ddt, size_t nentries, dmu_tx_t *tx,
    ddt_log_update_t *dlu);
extern void ddt_log_entry(ddt_t *ddt, ddt_lightweight_entry_t *dde,
    ddt_log_update_t *dlu);
extern void ddt_log_commit(ddt_t *ddt, ddt_log_update_t *dlu);

extern boolean_t ddt_log_take_first(ddt_t *ddt, ddt_log_t *ddl,
    ddt_lightweight_entry_t *ddlwe);

extern boolean_t ddt_log_find_key(ddt_t *ddt, const ddt_key_t *ddk,
    ddt_lightweight_entry_t *ddlwe);
extern boolean_t ddt_log_remove_key(ddt_t *ddt, ddt_log_t *ddl,
    const ddt_key_t *ddk);

extern void ddt_log_checkpoint(ddt_t *ddt, ddt_lightweight_entry_t *ddlwe,
    dmu_tx_t *tx);
extern void ddt_log_truncate(ddt_t *ddt, dmu_tx_t *tx);

extern boolean_t ddt_log_swap(ddt_t *ddt, dmu_tx_t *tx);

extern void ddt_log_destroy(ddt_t *ddt, dmu_tx_t *tx);

extern int ddt_log_load(ddt_t *ddt);
extern void ddt_log_alloc(ddt_t *ddt);
extern void ddt_log_free(ddt_t *ddt);

extern void ddt_log_init(void);
extern void ddt_log_fini(void);

/*
 * These are only exposed so that zdb can access them. Try not to use them
 * outside of the DDT implementation proper, and if you do, consider moving
 * them up.
 */

/*
 * We use a histogram to convert a percentage request into a
 * cutoff value where entries older than the cutoff get pruned.
 *
 * The histogram bins represent hours in power-of-two increments.
 * 16 bins covers up to four years.
 */
#define	HIST_BINS 16

typedef struct ddt_age_histo {
	uint64_t dah_entries;
	uint64_t dah_age_histo[HIST_BINS];
} ddt_age_histo_t;

void ddt_prune_walk(spa_t *spa, uint64_t cutoff, ddt_age_histo_t *histogram);

#if defined(_KERNEL) || !defined(ZFS_DEBUG)
#define	ddt_dump_age_histogram(histo, cutoff)	((void)0)
#else
static inline void
ddt_dump_age_histogram(ddt_age_histo_t *histogram, uint64_t cutoff)
{
	if (histogram->dah_entries == 0)
		return;

	(void) printf("DDT prune unique class age, %llu hour cutoff\n",
	    (u_longlong_t)(gethrestime_sec() - cutoff)/3600);
	(void) printf("%5s  %9s  %4s\n", "age", "blocks", "amnt");
	(void) printf("%5s  %9s  %4s\n", "-----", "---------", "----");
	for (int i = 0; i < HIST_BINS; i++) {
		(void) printf("%5d  %9llu %4d%%\n", 1<<i,
		    (u_longlong_t)histogram->dah_age_histo[i],
		    (int)((histogram->dah_age_histo[i] * 100) /
		    histogram->dah_entries));
	}
}
#endif

/*
 * Enough room to expand DMU_POOL_DDT format for all possible DDT
 * checksum/class/type combinations.
 */
#define	DDT_NAMELEN	32

extern uint64_t ddt_phys_total_refcnt(const ddt_t *ddt,
    const ddt_univ_phys_t *ddp);

extern void ddt_key_fill(ddt_key_t *ddk, const blkptr_t *bp);

extern void ddt_object_name(ddt_t *ddt, ddt_type_t type, ddt_class_t clazz,
    char *name);
extern int ddt_object_walk(ddt_t *ddt, ddt_type_t type, ddt_class_t clazz,
    uint64_t *walk, ddt_lightweight_entry_t *ddlwe);
extern int ddt_object_count(ddt_t *ddt, ddt_type_t type, ddt_class_t clazz,
    uint64_t *count);
extern int ddt_object_info(ddt_t *ddt, ddt_type_t type, ddt_class_t clazz,
    dmu_object_info_t *);

#ifdef	__cplusplus
}
#endif

#endif	/* _SYS_DDT_H */