/*
 * 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 2011 Nexenta Systems, Inc.  All rights reserved.
 * Copyright (c) 2012, 2018 by Delphix. All rights reserved.
 * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
 * Copyright 2019, Joyent, Inc.
 * Copyright 2016 Toomas Soome <tsoome@me.com>
 */

#ifndef _ZIO_H
#define _ZIO_H

#include <sys/zio_priority.h>
#include <sys/zfs_context.h>
#include <sys/spa.h>
#include <sys/txg.h>
#include <sys/avl.h>
#include <sys/fs/zfs.h>
#include <sys/zio_impl.h>

#ifdef  __cplusplus
extern "C" {
#endif

/*
 * Embedded checksum
 */
#define ZEC_MAGIC       0x210da7ab10c7a11ULL

typedef struct zio_eck {
        uint64_t        zec_magic;      /* for validation, endianness   */
        zio_cksum_t     zec_cksum;      /* 256-bit checksum             */
} zio_eck_t;

/*
 * Gang block headers are self-checksumming and contain an array
 * of block pointers.
 */
#define SPA_GANGBLOCKSIZE       SPA_MINBLOCKSIZE
#define SPA_GBH_NBLKPTRS        ((SPA_GANGBLOCKSIZE - \
        sizeof (zio_eck_t)) / sizeof (blkptr_t))
#define SPA_GBH_FILLER          ((SPA_GANGBLOCKSIZE - \
        sizeof (zio_eck_t) - \
        (SPA_GBH_NBLKPTRS * sizeof (blkptr_t))) /\
        sizeof (uint64_t))

typedef struct zio_gbh {
        blkptr_t                zg_blkptr[SPA_GBH_NBLKPTRS];
        uint64_t                zg_filler[SPA_GBH_FILLER];
        zio_eck_t               zg_tail;
} zio_gbh_phys_t;

enum zio_checksum {
        ZIO_CHECKSUM_INHERIT = 0,
        ZIO_CHECKSUM_ON,
        ZIO_CHECKSUM_OFF,
        ZIO_CHECKSUM_LABEL,
        ZIO_CHECKSUM_GANG_HEADER,
        ZIO_CHECKSUM_ZILOG,
        ZIO_CHECKSUM_FLETCHER_2,
        ZIO_CHECKSUM_FLETCHER_4,
        ZIO_CHECKSUM_SHA256,
        ZIO_CHECKSUM_ZILOG2,
        ZIO_CHECKSUM_NOPARITY,
        ZIO_CHECKSUM_SHA512,
        ZIO_CHECKSUM_SKEIN,
        ZIO_CHECKSUM_EDONR,
        ZIO_CHECKSUM_FUNCTIONS
};

/*
 * The number of "legacy" compression functions which can be set on individual
 * objects.
 */
#define ZIO_CHECKSUM_LEGACY_FUNCTIONS ZIO_CHECKSUM_ZILOG2

#define ZIO_CHECKSUM_ON_VALUE   ZIO_CHECKSUM_FLETCHER_4
#define ZIO_CHECKSUM_DEFAULT    ZIO_CHECKSUM_ON

#define ZIO_CHECKSUM_MASK       0xffULL
#define ZIO_CHECKSUM_VERIFY     (1 << 8)

#define ZIO_DEDUPCHECKSUM       ZIO_CHECKSUM_SHA256
#define ZIO_DEDUPDITTO_MIN      100

#define ZIO_CRYPT_ON_VALUE      ZIO_CRYPT_AES_256_CCM
#define ZIO_CRYPT_DEFAULT       ZIO_CRYPT_OFF

/* macros defining encryption lengths */
#define ZIO_OBJSET_MAC_LEN              32
#define ZIO_DATA_IV_LEN                 12
#define ZIO_DATA_SALT_LEN               8
#define ZIO_DATA_MAC_LEN                16

/*
 * The number of "legacy" compression functions which can be set on individual
 * objects.
 */
#define ZIO_COMPRESS_LEGACY_FUNCTIONS ZIO_COMPRESS_LZ4

/*
 * The meaning of "compress = on" selected by the compression features enabled
 * on a given pool.
 */
#define ZIO_COMPRESS_LEGACY_ON_VALUE    ZIO_COMPRESS_LZJB
#define ZIO_COMPRESS_LZ4_ON_VALUE       ZIO_COMPRESS_LZ4

#define ZIO_COMPRESS_DEFAULT            ZIO_COMPRESS_OFF

#define BOOTFS_COMPRESS_VALID(compress)                 \
        ((compress) == ZIO_COMPRESS_LZJB ||             \
        (compress) == ZIO_COMPRESS_LZ4 ||               \
        (compress) == ZIO_COMPRESS_GZIP_1 ||            \
        (compress) == ZIO_COMPRESS_GZIP_2 ||            \
        (compress) == ZIO_COMPRESS_GZIP_3 ||            \
        (compress) == ZIO_COMPRESS_GZIP_4 ||            \
        (compress) == ZIO_COMPRESS_GZIP_5 ||            \
        (compress) == ZIO_COMPRESS_GZIP_6 ||            \
        (compress) == ZIO_COMPRESS_GZIP_7 ||            \
        (compress) == ZIO_COMPRESS_GZIP_8 ||            \
        (compress) == ZIO_COMPRESS_GZIP_9 ||            \
        (compress) == ZIO_COMPRESS_ON ||                \
        (compress) == ZIO_COMPRESS_OFF)

#define ZIO_FAILURE_MODE_WAIT           0
#define ZIO_FAILURE_MODE_CONTINUE       1
#define ZIO_FAILURE_MODE_PANIC          2

typedef enum zio_suspend_reason {
        ZIO_SUSPEND_NONE = 0,
        ZIO_SUSPEND_IOERR,
        ZIO_SUSPEND_MMP,
} zio_suspend_reason_t;

enum zio_flag {
        /*
         * Flags inherited by gang, ddt, and vdev children,
         * and that must be equal for two zios to aggregate
         */
        ZIO_FLAG_DONT_AGGREGATE = 1 << 0,
        ZIO_FLAG_IO_REPAIR      = 1 << 1,
        ZIO_FLAG_SELF_HEAL      = 1 << 2,
        ZIO_FLAG_RESILVER       = 1 << 3,
        ZIO_FLAG_SCRUB          = 1 << 4,
        ZIO_FLAG_SCAN_THREAD    = 1 << 5,
        ZIO_FLAG_PHYSICAL       = 1 << 6,

#define ZIO_FLAG_AGG_INHERIT    (ZIO_FLAG_CANFAIL - 1)

        /*
         * Flags inherited by ddt, gang, and vdev children.
         */
        ZIO_FLAG_CANFAIL        = 1 << 7,       /* must be first for INHERIT */
        ZIO_FLAG_SPECULATIVE    = 1 << 8,
        ZIO_FLAG_CONFIG_WRITER  = 1 << 9,
        ZIO_FLAG_DONT_RETRY     = 1 << 10,
        ZIO_FLAG_DONT_CACHE     = 1 << 11,
        ZIO_FLAG_NODATA         = 1 << 12,
        ZIO_FLAG_INDUCE_DAMAGE  = 1 << 13,
        ZIO_FLAG_IO_ALLOCATING  = 1 << 14,

#define ZIO_FLAG_DDT_INHERIT    (ZIO_FLAG_IO_RETRY - 1)
#define ZIO_FLAG_GANG_INHERIT   (ZIO_FLAG_IO_RETRY - 1)

        /*
         * Flags inherited by vdev children.
         */
        ZIO_FLAG_IO_RETRY       = 1 << 15,      /* must be first for INHERIT */
        ZIO_FLAG_PROBE          = 1 << 16,
        ZIO_FLAG_TRYHARD        = 1 << 17,
        ZIO_FLAG_OPTIONAL       = 1 << 18,

#define ZIO_FLAG_VDEV_INHERIT   (ZIO_FLAG_DONT_QUEUE - 1)

        /*
         * Flags not inherited by any children.
         */
        ZIO_FLAG_DONT_QUEUE     = 1 << 19,      /* must be first for INHERIT */
        ZIO_FLAG_DONT_PROPAGATE = 1 << 20,
        ZIO_FLAG_IO_BYPASS      = 1 << 21,
        ZIO_FLAG_IO_REWRITE     = 1 << 22,
        ZIO_FLAG_RAW_COMPRESS   = 1 << 23,
        ZIO_FLAG_RAW_ENCRYPT    = 1 << 24,
        ZIO_FLAG_GANG_CHILD     = 1 << 25,
        ZIO_FLAG_DDT_CHILD      = 1 << 26,
        ZIO_FLAG_GODFATHER      = 1 << 27,
        ZIO_FLAG_NOPWRITE       = 1 << 28,
        ZIO_FLAG_REEXECUTED     = 1 << 29,
        ZIO_FLAG_DELEGATED      = 1 << 30,
};

#define ZIO_FLAG_MUSTSUCCEED            0
#define ZIO_FLAG_RAW    (ZIO_FLAG_RAW_COMPRESS | ZIO_FLAG_RAW_ENCRYPT)

#define ZIO_DDT_CHILD_FLAGS(zio)                                \
        (((zio)->io_flags & ZIO_FLAG_DDT_INHERIT) |             \
        ZIO_FLAG_DDT_CHILD | ZIO_FLAG_CANFAIL)

#define ZIO_GANG_CHILD_FLAGS(zio)                               \
        (((zio)->io_flags & ZIO_FLAG_GANG_INHERIT) |            \
        ZIO_FLAG_GANG_CHILD | ZIO_FLAG_CANFAIL)

#define ZIO_VDEV_CHILD_FLAGS(zio)                               \
        (((zio)->io_flags & ZIO_FLAG_VDEV_INHERIT) |            \
        ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_CANFAIL)

#define ZIO_CHILD_BIT(x)                (1 << (x))
#define ZIO_CHILD_BIT_IS_SET(val, x)    ((val) & (1 << (x)))

enum zio_child {
        ZIO_CHILD_VDEV = 0,
        ZIO_CHILD_GANG,
        ZIO_CHILD_DDT,
        ZIO_CHILD_LOGICAL,
        ZIO_CHILD_TYPES
};

#define ZIO_CHILD_VDEV_BIT              ZIO_CHILD_BIT(ZIO_CHILD_VDEV)
#define ZIO_CHILD_GANG_BIT              ZIO_CHILD_BIT(ZIO_CHILD_GANG)
#define ZIO_CHILD_DDT_BIT               ZIO_CHILD_BIT(ZIO_CHILD_DDT)
#define ZIO_CHILD_LOGICAL_BIT           ZIO_CHILD_BIT(ZIO_CHILD_LOGICAL)
#define ZIO_CHILD_ALL_BITS                                      \
        (ZIO_CHILD_VDEV_BIT | ZIO_CHILD_GANG_BIT |              \
        ZIO_CHILD_DDT_BIT | ZIO_CHILD_LOGICAL_BIT)

enum zio_wait_type {
        ZIO_WAIT_READY = 0,
        ZIO_WAIT_DONE,
        ZIO_WAIT_TYPES
};

/*
 * We'll take the unused errnos, 'EBADE' and 'EBADR' (from the Convergent
 * graveyard) to indicate checksum errors and fragmentation.
 */
#define ECKSUM  EBADE
#define EFRAGS  EBADR

typedef void zio_done_func_t(zio_t *zio);

extern boolean_t zio_dva_throttle_enabled;
extern const char *zio_type_name[ZIO_TYPES];

/*
 * A bookmark is a four-tuple <objset, object, level, blkid> that uniquely
 * identifies any block in the pool.  By convention, the meta-objset (MOS)
 * is objset 0, and the meta-dnode is object 0.  This covers all blocks
 * except root blocks and ZIL blocks, which are defined as follows:
 *
 * Root blocks (objset_phys_t) are object 0, level -1:  <objset, 0, -1, 0>.
 * ZIL blocks are bookmarked <objset, 0, -2, blkid == ZIL sequence number>.
 * dmu_sync()ed ZIL data blocks are bookmarked <objset, object, -2, blkid>.
 * dnode visit bookmarks are <objset, object id of dnode, -3, 0>.
 *
 * Note: this structure is called a bookmark because its original purpose
 * was to remember where to resume a pool-wide traverse.
 *
 * Note: this structure is passed between userland and the kernel, and is
 * stored on disk (by virtue of being incorporated into other on-disk
 * structures, e.g. dsl_scan_phys_t).
 */
typedef struct zbookmark_phys {
        uint64_t        zb_objset;
        uint64_t        zb_object;
        int64_t         zb_level;
        uint64_t        zb_blkid;
} zbookmark_phys_t;

#define SET_BOOKMARK(zb, objset, object, level, blkid)  \
{                                                       \
        (zb)->zb_objset = objset;                       \
        (zb)->zb_object = object;                       \
        (zb)->zb_level = level;                         \
        (zb)->zb_blkid = blkid;                         \
}

#define ZB_DESTROYED_OBJSET     (-1ULL)

#define ZB_ROOT_OBJECT          (0ULL)
#define ZB_ROOT_LEVEL           (-1LL)
#define ZB_ROOT_BLKID           (0ULL)

#define ZB_ZIL_OBJECT           (0ULL)
#define ZB_ZIL_LEVEL            (-2LL)

#define ZB_DNODE_LEVEL          (-3LL)
#define ZB_DNODE_BLKID          (0ULL)

#define ZB_IS_ZERO(zb)                                          \
        ((zb)->zb_objset == 0 && (zb)->zb_object == 0 &&        \
        (zb)->zb_level == 0 && (zb)->zb_blkid == 0)
#define ZB_IS_ROOT(zb)                          \
        ((zb)->zb_object == ZB_ROOT_OBJECT &&   \
        (zb)->zb_level == ZB_ROOT_LEVEL &&      \
        (zb)->zb_blkid == ZB_ROOT_BLKID)

typedef struct zio_prop {
        enum zio_checksum       zp_checksum;
        enum zio_compress       zp_compress;
        dmu_object_type_t       zp_type;
        uint8_t                 zp_level;
        uint8_t                 zp_copies;
        boolean_t               zp_dedup;
        boolean_t               zp_dedup_verify;
        boolean_t               zp_nopwrite;
        uint32_t                zp_zpl_smallblk;
        boolean_t               zp_encrypt;
        boolean_t               zp_byteorder;
        uint8_t                 zp_salt[ZIO_DATA_SALT_LEN];
        uint8_t                 zp_iv[ZIO_DATA_IV_LEN];
        uint8_t                 zp_mac[ZIO_DATA_MAC_LEN];
} zio_prop_t;

typedef struct zio_cksum_report zio_cksum_report_t;

typedef void zio_cksum_finish_f(zio_cksum_report_t *rep,
    const abd_t *good_data);
typedef void zio_cksum_free_f(void *cbdata, size_t size);

struct zio_bad_cksum;                           /* defined in zio_checksum.h */
struct dnode_phys;
struct abd;

struct zio_cksum_report {
        struct zio_cksum_report *zcr_next;
        nvlist_t                *zcr_ereport;
        nvlist_t                *zcr_detector;
        void                    *zcr_cbdata;
        size_t                  zcr_cbinfo;     /* passed to zcr_free() */
        uint64_t                zcr_align;
        uint64_t                zcr_length;
        zio_cksum_finish_f      *zcr_finish;
        zio_cksum_free_f        *zcr_free;

        /* internal use only */
        struct zio_bad_cksum    *zcr_ckinfo;    /* information from failure */
};

typedef void zio_vsd_cksum_report_f(zio_t *zio, zio_cksum_report_t *zcr,
    void *arg);

zio_vsd_cksum_report_f  zio_vsd_default_cksum_report;

typedef struct zio_vsd_ops {
        zio_done_func_t         *vsd_free;
        zio_vsd_cksum_report_f  *vsd_cksum_report;
} zio_vsd_ops_t;

typedef struct zio_gang_node {
        zio_gbh_phys_t          *gn_gbh;
        struct zio_gang_node    *gn_child[SPA_GBH_NBLKPTRS];
} zio_gang_node_t;

typedef zio_t *zio_gang_issue_func_t(zio_t *zio, blkptr_t *bp,
    zio_gang_node_t *gn, struct abd *data, uint64_t offset);

typedef void zio_transform_func_t(zio_t *zio, struct abd *data, uint64_t size);

typedef struct zio_transform {
        struct abd              *zt_orig_abd;
        uint64_t                zt_orig_size;
        uint64_t                zt_bufsize;
        zio_transform_func_t    *zt_transform;
        struct zio_transform    *zt_next;
} zio_transform_t;

typedef int zio_pipe_stage_t(zio_t *zio);

/*
 * The io_reexecute flags are distinct from io_flags because the child must
 * be able to propagate them to the parent.  The normal io_flags are local
 * to the zio, not protected by any lock, and not modifiable by children;
 * the reexecute flags are protected by io_lock, modifiable by children,
 * and always propagated -- even when ZIO_FLAG_DONT_PROPAGATE is set.
 */
#define ZIO_REEXECUTE_NOW       0x01
#define ZIO_REEXECUTE_SUSPEND   0x02

/*
 * The io_trim flags are used to specify the type of TRIM to perform.  They
 * only apply to ZIO_TYPE_TRIM zios and are distinct from io_flags.
 */
enum trim_flag {
        ZIO_TRIM_SECURE         = 1 << 0,
};

typedef struct zio_alloc_list {
        list_t  zal_list;
        uint64_t zal_size;
} zio_alloc_list_t;

typedef struct zio_link {
        zio_t           *zl_parent;
        zio_t           *zl_child;
        list_node_t     zl_parent_node;
        list_node_t     zl_child_node;
} zio_link_t;

struct zio {
        /* Core information about this I/O */
        zbookmark_phys_t        io_bookmark;
        zio_prop_t      io_prop;
        zio_type_t      io_type;
        enum zio_child  io_child_type;
        enum trim_flag  io_trim_flags;
        int             io_cmd;
        zio_priority_t  io_priority;
        uint8_t         io_reexecute;
        uint8_t         io_state[ZIO_WAIT_TYPES];
        uint64_t        io_txg;
        spa_t           *io_spa;
        blkptr_t        *io_bp;
        blkptr_t        *io_bp_override;
        blkptr_t        io_bp_copy;
        list_t          io_parent_list;
        list_t          io_child_list;
        zio_t           *io_logical;
        zio_transform_t *io_transform_stack;

        /* Callback info */
        zio_done_func_t *io_ready;
        zio_done_func_t *io_children_ready;
        zio_done_func_t *io_physdone;
        zio_done_func_t *io_done;
        void            *io_private;
        int64_t         io_prev_space_delta;    /* DMU private */
        blkptr_t        io_bp_orig;

        /* Data represented by this I/O */
        struct abd      *io_abd;
        struct abd      *io_orig_abd;
        uint64_t        io_size;
        uint64_t        io_orig_size;
        /* io_lsize != io_orig_size iff this is a raw write */
        uint64_t        io_lsize;

        /* Stuff for the vdev stack */
        vdev_t          *io_vd;
        void            *io_vsd;
        const zio_vsd_ops_t *io_vsd_ops;
        metaslab_class_t *io_metaslab_class;    /* dva throttle class */

        uint64_t        io_offset;
        hrtime_t        io_timestamp;
        hrtime_t        io_queued_timestamp;
        hrtime_t        io_target_timestamp;
        hrtime_t        io_delta;       /* vdev queue service delta */
        hrtime_t        io_delay;       /* Device access time (disk or */
                                        /* file). */
        avl_node_t      io_queue_node;
        avl_node_t      io_offset_node;
        avl_node_t      io_alloc_node;
        zio_alloc_list_t        io_alloc_list;

        /* Internal pipeline state */
        enum zio_flag   io_flags;
        enum zio_stage  io_stage;
        enum zio_stage  io_pipeline;
        enum zio_flag   io_orig_flags;
        enum zio_stage  io_orig_stage;
        enum zio_stage  io_orig_pipeline;
        enum zio_stage  io_pipeline_trace;
        int             io_error;
        int             io_child_error[ZIO_CHILD_TYPES];
        uint64_t        io_children[ZIO_CHILD_TYPES][ZIO_WAIT_TYPES];
        uint64_t        io_child_count;
        uint64_t        io_phys_children;
        uint64_t        io_parent_count;
        uint64_t        *io_stall;
        zio_t           *io_gang_leader;
        zio_gang_node_t *io_gang_tree;
        void            *io_executor;
        void            *io_waiter;
        kmutex_t        io_lock;
        kcondvar_t      io_cv;
        int             io_allocator;

        /* FMA state */
        zio_cksum_report_t *io_cksum_report;
        uint64_t        io_ena;

        /* Taskq dispatching state */
        taskq_ent_t     io_tqent;
};

extern int zio_bookmark_compare(const void *, const void *);

extern zio_t *zio_null(zio_t *pio, spa_t *spa, vdev_t *vd,
    zio_done_func_t *done, void *private, enum zio_flag flags);

extern zio_t *zio_root(spa_t *spa,
    zio_done_func_t *done, void *private, enum zio_flag flags);

extern zio_t *zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
    struct abd *data, uint64_t lsize, zio_done_func_t *done, void *private,
    zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb);

extern zio_t *zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
    struct abd *data, uint64_t size, uint64_t psize, const zio_prop_t *zp,
    zio_done_func_t *ready, zio_done_func_t *children_ready,
    zio_done_func_t *physdone, zio_done_func_t *done,
    void *private, zio_priority_t priority, enum zio_flag flags,
    const zbookmark_phys_t *zb);

extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
    struct abd *data, uint64_t size, zio_done_func_t *done, void *private,
    zio_priority_t priority, enum zio_flag flags, zbookmark_phys_t *zb);

extern void zio_write_override(zio_t *zio, blkptr_t *bp, int copies,
    boolean_t nopwrite);

extern void zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp);

extern zio_t *zio_claim(zio_t *pio, spa_t *spa, uint64_t txg,
    const blkptr_t *bp,
    zio_done_func_t *done, void *private, enum zio_flag flags);

extern zio_t *zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
    zio_done_func_t *done, void *private, enum zio_flag flags);

extern zio_t *zio_trim(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size,
    zio_done_func_t *done, void *private, zio_priority_t priority,
    enum zio_flag flags, enum trim_flag trim_flags);

extern zio_t *zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
    uint64_t size, struct abd *data, int checksum,
    zio_done_func_t *done, void *private, zio_priority_t priority,
    enum zio_flag flags, boolean_t labels);

extern zio_t *zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
    uint64_t size, struct abd *data, int checksum,
    zio_done_func_t *done, void *private, zio_priority_t priority,
    enum zio_flag flags, boolean_t labels);

extern zio_t *zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg,
    const blkptr_t *bp, enum zio_flag flags);

extern int zio_alloc_zil(spa_t *spa, objset_t *os, uint64_t txg,
    blkptr_t *new_bp, blkptr_t *old_bp, uint64_t size, boolean_t *slog);
extern void zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp);
extern void zio_flush(zio_t *zio, vdev_t *vd);
extern void zio_shrink(zio_t *zio, uint64_t size);

extern int zio_wait(zio_t *zio);
extern void zio_nowait(zio_t *zio);
extern void zio_execute(zio_t *zio);
extern void zio_interrupt(zio_t *zio);
extern void zio_delay_init(zio_t *zio);
extern void zio_delay_interrupt(zio_t *zio);

extern zio_t *zio_walk_parents(zio_t *cio, zio_link_t **);
extern zio_t *zio_walk_children(zio_t *pio, zio_link_t **);
extern zio_t *zio_unique_parent(zio_t *cio);
extern void zio_add_child(zio_t *pio, zio_t *cio);

extern void *zio_buf_alloc(size_t size);
extern void zio_buf_free(void *buf, size_t size);
extern void *zio_data_buf_alloc(size_t size);
extern void zio_data_buf_free(void *buf, size_t size);

extern void zio_push_transform(zio_t *zio, struct abd *abd, uint64_t size,
    uint64_t bufsize, zio_transform_func_t *transform);
extern void zio_pop_transforms(zio_t *zio);

extern void zio_resubmit_stage_async(void *);

extern zio_t *zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd,
    uint64_t offset, struct abd *data, uint64_t size, int type,
    zio_priority_t priority, enum zio_flag flags,
    zio_done_func_t *done, void *private);

extern zio_t *zio_vdev_delegated_io(vdev_t *vd, uint64_t offset,
    struct abd *data, uint64_t size, zio_type_t type, zio_priority_t priority,
    enum zio_flag flags, zio_done_func_t *done, void *private);

extern void zio_vdev_io_bypass(zio_t *zio);
extern void zio_vdev_io_reissue(zio_t *zio);
extern void zio_vdev_io_redone(zio_t *zio);

extern void zio_change_priority(zio_t *pio, zio_priority_t priority);

extern void zio_checksum_verified(zio_t *zio);
extern int zio_worst_error(int e1, int e2);

extern enum zio_checksum zio_checksum_select(enum zio_checksum child,
    enum zio_checksum parent);
extern enum zio_checksum zio_checksum_dedup_select(spa_t *spa,
    enum zio_checksum child, enum zio_checksum parent);
extern enum zio_compress zio_compress_select(spa_t *spa,
    enum zio_compress child, enum zio_compress parent);

extern void zio_suspend(spa_t *spa, zio_t *zio, zio_suspend_reason_t);
extern int zio_resume(spa_t *spa);
extern void zio_resume_wait(spa_t *spa);

/*
 * Initial setup and teardown.
 */
extern void zio_init(void);
extern void zio_fini(void);

/*
 * Fault injection
 */
struct zinject_record;
extern uint32_t zio_injection_enabled;
extern int zio_inject_fault(char *name, int flags, int *id,
    struct zinject_record *record);
extern int zio_inject_list_next(int *id, char *name, size_t buflen,
    struct zinject_record *record);
extern int zio_clear_fault(int id);
extern void zio_handle_panic_injection(spa_t *spa, char *tag, uint64_t type);
extern int zio_handle_decrypt_injection(spa_t *spa, const zbookmark_phys_t *zb,
    uint64_t type, int error);
extern int zio_handle_fault_injection(zio_t *zio, int error);
extern int zio_handle_device_injection(vdev_t *vd, zio_t *zio, int error);
extern int zio_handle_label_injection(zio_t *zio, int error);
extern void zio_handle_ignored_writes(zio_t *zio);
extern hrtime_t zio_handle_io_delay(zio_t *zio);

/*
 * Checksum ereport functions
 */
extern void zfs_ereport_start_checksum(spa_t *spa, vdev_t *vd,
    const zbookmark_phys_t *zb, struct zio *zio, uint64_t offset,
    uint64_t length, void *arg, struct zio_bad_cksum *info);
extern void zfs_ereport_finish_checksum(zio_cksum_report_t *report,
    const abd_t *good_data, const abd_t *bad_data, boolean_t drop_if_identical);

extern void zfs_ereport_send_interim_checksum(zio_cksum_report_t *report);
extern void zfs_ereport_free_checksum(zio_cksum_report_t *report);

/* If we have the good data in hand, this function can be used */
extern int zfs_ereport_post_checksum(spa_t *spa, vdev_t *vd,
    const zbookmark_phys_t *zb, struct zio *zio, uint64_t offset,
    uint64_t length, const abd_t *good_data, const abd_t *bad_data,
    struct zio_bad_cksum *info);

/* Called from spa_sync(), but primarily an injection handler */
extern void spa_handle_ignored_writes(spa_t *spa);

/* zbookmark_phys functions */
boolean_t zbookmark_subtree_completed(const struct dnode_phys *dnp,
    const zbookmark_phys_t *subtree_root, const zbookmark_phys_t *last_block);
int zbookmark_compare(uint16_t dbss1, uint8_t ibs1, uint16_t dbss2,
    uint8_t ibs2, const zbookmark_phys_t *zb1, const zbookmark_phys_t *zb2);

#ifdef  __cplusplus
}
#endif

#endif  /* _ZIO_H */