/*
 * 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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2012, 2017 by Delphix. All rights reserved.
 * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
 * Copyright 2024 Bill Sommerfeld <sommerfeld@hamachi.org>
 */

#ifndef _SYS_ARC_H
#define _SYS_ARC_H

#include <sys/zfs_context.h>

#ifdef  __cplusplus
extern "C" {
#endif

#include <sys/zio.h>
#include <sys/dmu.h>
#include <sys/spa.h>

/*
 * Used by arc_flush() to inform arc_evict_state() that it should evict
 * all available buffers from the arc state being passed in.
 */
#define ARC_EVICT_ALL   -1ULL

#define HDR_SET_LSIZE(hdr, x) do { \
        ASSERT(IS_P2ALIGNED(x, 1U << SPA_MINBLOCKSHIFT)); \
        (hdr)->b_lsize = ((x) >> SPA_MINBLOCKSHIFT); \
_NOTE(CONSTCOND) } while (0)

#define HDR_SET_PSIZE(hdr, x) do { \
        ASSERT(IS_P2ALIGNED((x), 1U << SPA_MINBLOCKSHIFT)); \
        (hdr)->b_psize = ((x) >> SPA_MINBLOCKSHIFT); \
_NOTE(CONSTCOND) } while (0)

#define HDR_GET_LSIZE(hdr)      ((hdr)->b_lsize << SPA_MINBLOCKSHIFT)
#define HDR_GET_PSIZE(hdr)      ((hdr)->b_psize << SPA_MINBLOCKSHIFT)

typedef struct arc_buf_hdr arc_buf_hdr_t;
typedef struct arc_buf arc_buf_t;

/*
 * Because the ARC can store encrypted data, errors (not due to bugs) may arise
 * while transforming data into its desired format - specifically, when
 * decrypting, the key may not be present, or the HMAC may not be correct
 * which signifies deliberate tampering with the on-disk state
 * (assuming that the checksum was correct). The "error" parameter will be
 * nonzero in this case, even if there is no associated zio.
 */
typedef void arc_read_done_func_t(zio_t *zio, const zbookmark_phys_t *zb,
    const blkptr_t *bp, arc_buf_t *buf, void *priv);
typedef void arc_write_done_func_t(zio_t *zio, arc_buf_t *buf, void *priv);

/* generic arc_done_func_t's which you can use */
arc_read_done_func_t arc_bcopy_func;
arc_read_done_func_t arc_getbuf_func;

typedef enum arc_flags
{
        /*
         * Public flags that can be passed into the ARC by external consumers.
         */
        ARC_FLAG_WAIT                   = 1 << 0,       /* perform sync I/O */
        ARC_FLAG_NOWAIT                 = 1 << 1,       /* perform async I/O */
        ARC_FLAG_PREFETCH               = 1 << 2,       /* I/O is a prefetch */
        ARC_FLAG_CACHED                 = 1 << 3,       /* I/O was in cache */
        ARC_FLAG_L2CACHE                = 1 << 4,       /* cache in L2ARC */
        ARC_FLAG_PREDICTIVE_PREFETCH    = 1 << 5,       /* I/O from zfetch */
        ARC_FLAG_PRESCIENT_PREFETCH     = 1 << 6,       /* long min lifespan */

        /*
         * Private ARC flags.  These flags are private ARC only flags that
         * will show up in b_flags in the arc_hdr_buf_t. These flags should
         * only be set by ARC code.
         */
        ARC_FLAG_IN_HASH_TABLE          = 1 << 7,       /* buffer is hashed */
        ARC_FLAG_IO_IN_PROGRESS         = 1 << 8,       /* I/O in progress */
        ARC_FLAG_IO_ERROR               = 1 << 9,       /* I/O failed for buf */
        ARC_FLAG_INDIRECT               = 1 << 10,      /* indirect block */
        /* Indicates that block was read with ASYNC priority. */
        ARC_FLAG_PRIO_ASYNC_READ        = 1 << 11,
        ARC_FLAG_L2_WRITING             = 1 << 12,      /* write in progress */
        ARC_FLAG_L2_EVICTED             = 1 << 13,      /* evicted during I/O */
        ARC_FLAG_L2_WRITE_HEAD          = 1 << 14,      /* head of write list */
        /*
         * Encrypted or authenticated on disk (may be plaintext in memory).
         * This header has b_crypt_hdr allocated. Does not include indirect
         * blocks with checksums of MACs which will also have their X
         * (encrypted) bit set in the bp.
         */
        ARC_FLAG_PROTECTED              = 1 << 15,
        /* data has not been authenticated yet */
        ARC_FLAG_NOAUTH                 = 1 << 16,
        /* indicates that the buffer contains metadata (otherwise, data) */
        ARC_FLAG_BUFC_METADATA          = 1 << 17,

        /* Flags specifying whether optional hdr struct fields are defined */
        ARC_FLAG_HAS_L1HDR              = 1 << 18,
        ARC_FLAG_HAS_L2HDR              = 1 << 19,

        /*
         * Indicates the arc_buf_hdr_t's b_pdata matches the on-disk data.
         * This allows the l2arc to use the blkptr's checksum to verify
         * the data without having to store the checksum in the hdr.
         */
        ARC_FLAG_COMPRESSED_ARC         = 1 << 20,
        ARC_FLAG_SHARED_DATA            = 1 << 21,

        /*
         * The arc buffer's compression mode is stored in the top 7 bits of the
         * flags field, so these dummy flags are included so that MDB can
         * interpret the enum properly.
         */
        ARC_FLAG_COMPRESS_0             = 1 << 24,
        ARC_FLAG_COMPRESS_1             = 1 << 25,
        ARC_FLAG_COMPRESS_2             = 1 << 26,
        ARC_FLAG_COMPRESS_3             = 1 << 27,
        ARC_FLAG_COMPRESS_4             = 1 << 28,
        ARC_FLAG_COMPRESS_5             = 1 << 29,
        ARC_FLAG_COMPRESS_6             = 1 << 30

} arc_flags_t;

typedef enum arc_buf_flags {
        ARC_BUF_FLAG_SHARED             = 1 << 0,
        ARC_BUF_FLAG_COMPRESSED         = 1 << 1,
        /*
         * indicates whether this arc_buf_t is encrypted, regardless of
         * state on-disk
         */
        ARC_BUF_FLAG_ENCRYPTED          = 1 << 2
} arc_buf_flags_t;

struct arc_buf {
        arc_buf_hdr_t           *b_hdr;
        arc_buf_t               *b_next;
        kmutex_t                b_evict_lock;
        void                    *b_data;
        arc_buf_flags_t         b_flags;
};

typedef enum arc_buf_contents {
        ARC_BUFC_INVALID,                       /* invalid type */
        ARC_BUFC_DATA,                          /* buffer contains data */
        ARC_BUFC_METADATA,                      /* buffer contains metadata */
        ARC_BUFC_NUMTYPES
} arc_buf_contents_t;

/*
 * The following breakdows of arc_size exist for kstat only.
 */
typedef enum arc_space_type {
        ARC_SPACE_DATA,
        ARC_SPACE_META,
        ARC_SPACE_HDRS,
        ARC_SPACE_L2HDRS,
        ARC_SPACE_OTHER,
        ARC_SPACE_BONUS,
        ARC_SPACE_NUMTYPES
} arc_space_type_t;

typedef enum arc_state_type {
        ARC_STATE_ANON,
        ARC_STATE_MRU,
        ARC_STATE_MRU_GHOST,
        ARC_STATE_MFU,
        ARC_STATE_MFU_GHOST,
        ARC_STATE_L2C_ONLY,
        ARC_STATE_NUMTYPES
} arc_state_type_t;

void arc_space_consume(uint64_t space, arc_space_type_t type);
void arc_space_return(uint64_t space, arc_space_type_t type);
boolean_t arc_is_metadata(arc_buf_t *buf);
boolean_t arc_is_encrypted(arc_buf_t *buf);
boolean_t arc_is_unauthenticated(arc_buf_t *buf);
enum zio_compress arc_get_compression(arc_buf_t *buf);
void arc_get_raw_params(arc_buf_t *buf, boolean_t *byteorder, uint8_t *salt,
    uint8_t *iv, uint8_t *mac);
int arc_untransform(arc_buf_t *buf, spa_t *spa, const zbookmark_phys_t *zb,
    boolean_t in_place);
void arc_convert_to_raw(arc_buf_t *buf, uint64_t dsobj, boolean_t byteorder,
    dmu_object_type_t ot, const uint8_t *salt, const uint8_t *iv,
    const uint8_t *mac);
arc_buf_t *arc_alloc_buf(spa_t *spa, void *tag, arc_buf_contents_t type,
    int32_t size);
arc_buf_t *arc_alloc_compressed_buf(spa_t *spa, void *tag,
    uint64_t psize, uint64_t lsize, enum zio_compress compression_type);
arc_buf_t *arc_alloc_raw_buf(spa_t *spa, void *tag, uint64_t dsobj,
    boolean_t byteorder, const uint8_t *salt, const uint8_t *iv,
    const uint8_t *mac, dmu_object_type_t ot, uint64_t psize, uint64_t lsize,
    enum zio_compress compression_type);
arc_buf_t *arc_loan_buf(spa_t *spa, boolean_t is_metadata, int size);
arc_buf_t *arc_loan_compressed_buf(spa_t *spa, uint64_t psize, uint64_t lsize,
    enum zio_compress compression_type);
arc_buf_t *arc_loan_raw_buf(spa_t *spa, uint64_t dsobj, boolean_t byteorder,
    const uint8_t *salt, const uint8_t *iv, const uint8_t *mac,
    dmu_object_type_t ot, uint64_t psize, uint64_t lsize,
    enum zio_compress compression_type);
void arc_return_buf(arc_buf_t *buf, void *tag);
void arc_loan_inuse_buf(arc_buf_t *buf, void *tag);
void arc_buf_destroy(arc_buf_t *buf, void *tag);
int arc_buf_size(arc_buf_t *buf);
int arc_buf_lsize(arc_buf_t *buf);
void arc_buf_access(arc_buf_t *buf);
void arc_release(arc_buf_t *buf, void *tag);
int arc_released(arc_buf_t *buf);
void arc_buf_freeze(arc_buf_t *buf);
void arc_buf_thaw(arc_buf_t *buf);
#ifdef ZFS_DEBUG
int arc_referenced(arc_buf_t *buf);
#endif

int arc_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
    arc_read_done_func_t *done, void *private, zio_priority_t priority,
    int flags, arc_flags_t *arc_flags, const zbookmark_phys_t *zb);
zio_t *arc_write(zio_t *pio, spa_t *spa, uint64_t txg,
    blkptr_t *bp, arc_buf_t *buf, boolean_t l2arc, const zio_prop_t *zp,
    arc_write_done_func_t *ready, arc_write_done_func_t *child_ready,
    arc_write_done_func_t *physdone, arc_write_done_func_t *done,
    void *private, zio_priority_t priority, int zio_flags,
    const zbookmark_phys_t *zb);
void arc_freed(spa_t *spa, const blkptr_t *bp);

void arc_flush(spa_t *spa, boolean_t retry);
void arc_tempreserve_clear(uint64_t reserve);
int arc_tempreserve_space(spa_t *spa, uint64_t reserve, uint64_t txg);

boolean_t arc_memory_is_low(void);
uint64_t arc_all_memory(void);
uint64_t arc_max_bytes(void);
void arc_init(void);
void arc_fini(void);

/*
 * Level 2 ARC
 */

void l2arc_add_vdev(spa_t *spa, vdev_t *vd);
void l2arc_remove_vdev(vdev_t *vd);
boolean_t l2arc_vdev_present(vdev_t *vd);
void l2arc_rebuild_vdev(vdev_t *vd, boolean_t reopen);
boolean_t l2arc_range_check_overlap(uint64_t bottom, uint64_t top,
    uint64_t check);
void l2arc_init(void);
void l2arc_fini(void);
void l2arc_start(void);
void l2arc_stop(void);
void l2arc_spa_rebuild_start(spa_t *spa);

#ifndef _KERNEL
extern boolean_t arc_watch;
extern int arc_procfd;
#endif

#ifdef  __cplusplus
}
#endif

#endif /* _SYS_ARC_H */