sys/zio.h

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/*
 * 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 by Delphix. All rights reserved.
 */

#ifndef _ZIO_H
#define _ZIO_H

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

#ifdef  __cplusplus
extern "C" {
#endif

#define ZEC_MAGIC       0x210da7ab10c7a11ULL

typedef struct zio_eck {
        uint64_t        zec_magic;      
        zio_cksum_t     zec_cksum;      
} 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_FUNCTIONS
};

#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

enum zio_compress {
        ZIO_COMPRESS_INHERIT = 0,
        ZIO_COMPRESS_ON,
        ZIO_COMPRESS_OFF,
        ZIO_COMPRESS_LZJB,
        ZIO_COMPRESS_EMPTY,
        ZIO_COMPRESS_GZIP_1,
        ZIO_COMPRESS_GZIP_2,
        ZIO_COMPRESS_GZIP_3,
        ZIO_COMPRESS_GZIP_4,
        ZIO_COMPRESS_GZIP_5,
        ZIO_COMPRESS_GZIP_6,
        ZIO_COMPRESS_GZIP_7,
        ZIO_COMPRESS_GZIP_8,
        ZIO_COMPRESS_GZIP_9,
        ZIO_COMPRESS_ZLE,
        ZIO_COMPRESS_FUNCTIONS
};

#define ZIO_COMPRESS_ON_VALUE   ZIO_COMPRESS_LZJB
#define ZIO_COMPRESS_DEFAULT    ZIO_COMPRESS_OFF

#define BOOTFS_COMPRESS_VALID(compress)                 \
        ((compress) == ZIO_COMPRESS_LZJB ||             \
        ((compress) == ZIO_COMPRESS_ON &&               \
        ZIO_COMPRESS_ON_VALUE == ZIO_COMPRESS_LZJB) ||  \
        (compress) == ZIO_COMPRESS_OFF)

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

#define ZIO_PRIORITY_NOW                (zio_priority_table[0])
#define ZIO_PRIORITY_SYNC_READ          (zio_priority_table[1])
#define ZIO_PRIORITY_SYNC_WRITE         (zio_priority_table[2])
#define ZIO_PRIORITY_LOG_WRITE          (zio_priority_table[3])
#define ZIO_PRIORITY_CACHE_FILL         (zio_priority_table[4])
#define ZIO_PRIORITY_AGG                (zio_priority_table[5])
#define ZIO_PRIORITY_FREE               (zio_priority_table[6])
#define ZIO_PRIORITY_ASYNC_WRITE        (zio_priority_table[7])
#define ZIO_PRIORITY_ASYNC_READ         (zio_priority_table[8])
#define ZIO_PRIORITY_RESILVER           (zio_priority_table[9])
#define ZIO_PRIORITY_SCRUB              (zio_priority_table[10])
#define ZIO_PRIORITY_DDT_PREFETCH       (zio_priority_table[11])
#define ZIO_PRIORITY_TRIM               (zio_priority_table[12])
#define ZIO_PRIORITY_TABLE_SIZE         13

#define ZIO_PIPELINE_CONTINUE           0x100
#define ZIO_PIPELINE_STOP               0x101

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,

#define ZIO_FLAG_AGG_INHERIT    (ZIO_FLAG_CANFAIL - 1)

        /*
         * Flags inherited by ddt, gang, and vdev children.
         */
        ZIO_FLAG_CANFAIL        = 1 << 6,       /* must be first for INHERIT */
        ZIO_FLAG_SPECULATIVE    = 1 << 7,
        ZIO_FLAG_CONFIG_WRITER  = 1 << 8,
        ZIO_FLAG_DONT_RETRY     = 1 << 9,
        ZIO_FLAG_DONT_CACHE     = 1 << 10,
        ZIO_FLAG_NODATA         = 1 << 11,
        ZIO_FLAG_INDUCE_DAMAGE  = 1 << 12,

#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 << 13,      /* must be first for INHERIT */
        ZIO_FLAG_PROBE          = 1 << 14,
        ZIO_FLAG_TRYHARD        = 1 << 15,
        ZIO_FLAG_OPTIONAL       = 1 << 16,

#define ZIO_FLAG_VDEV_INHERIT   (ZIO_FLAG_DONT_QUEUE - 1)

        /*
         * Flags not inherited by any children.
         */
        ZIO_FLAG_DONT_QUEUE     = 1 << 17,      /* must be first for INHERIT */
        ZIO_FLAG_DONT_PROPAGATE = 1 << 18,
        ZIO_FLAG_IO_BYPASS      = 1 << 19,
        ZIO_FLAG_IO_REWRITE     = 1 << 20,
        ZIO_FLAG_RAW            = 1 << 21,
        ZIO_FLAG_GANG_CHILD     = 1 << 22,
        ZIO_FLAG_DDT_CHILD      = 1 << 23,
        ZIO_FLAG_GODFATHER      = 1 << 24
};

#define ZIO_FLAG_MUSTSUCCEED            0

#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_CANFAIL)

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

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

/*
 * We'll take the number 122 and 123 to indicate checksum errors and
 * fragmentation. Those doesn't collide with any errno values as they
 * are greater than ELAST.
 */
#define ECKSUM  122
#define EFRAGS  123

typedef void zio_done_func_t(zio_t *zio);

extern uint8_t zio_priority_table[ZIO_PRIORITY_TABLE_SIZE];
extern char *zio_type_name[ZIO_TYPES];

typedef struct zbookmark {
        uint64_t        zb_objset;
        uint64_t        zb_object;
        int64_t         zb_level;
        uint64_t        zb_blkid;
} zbookmark_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_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;
        uint8_t                 zp_dedup;
        uint8_t                 zp_dedup_verify;
} zio_prop_t;

typedef struct zio_cksum_report zio_cksum_report_t;

typedef void zio_cksum_finish_f(zio_cksum_report_t *rep,
    const void *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 zio_cksum_report {
        struct zio_cksum_report *zcr_next;
        nvlist_t                *zcr_ereport;
        nvlist_t                *zcr_detector;
        void                    *zcr_cbdata;
        size_t                  zcr_cbinfo;     
        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;    
};

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, void *data);

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

typedef struct zio_transform {
        void                    *zt_orig_data;
        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);

#define ZIO_REEXECUTE_NOW       0x01
#define ZIO_REEXECUTE_SUSPEND   0x02

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;

/*
 * Used for TRIM kstat.
 */
typedef struct zio_trim_stats {
        /*
         * Number of bytes successfully TRIMmed.
         */
        kstat_named_t zio_trim_bytes;

        /*
         * Number of successful TRIM requests.
         */
        kstat_named_t zio_trim_success;

        /*
         * Number of TRIM requests that failed because TRIM is not
         * supported.
         */
        kstat_named_t zio_trim_unsupported;

        /*
         * Number of TRIM requests that failed for other reasons.
         */
        kstat_named_t zio_trim_failed;
} zio_trim_stats_t;

extern zio_trim_stats_t zio_trim_stats;

#define ZIO_TRIM_STAT_INCR(stat, val) \
        atomic_add_64(&zio_trim_stats.stat.value.ui64, (val));
#define ZIO_TRIM_STAT_BUMP(stat) \
        ZIO_TRIM_STAT_INCR(stat, 1);

struct zio {
        zbookmark_t     io_bookmark;
        zio_prop_t      io_prop;
        zio_type_t      io_type;
        enum zio_child  io_child_type;
        int             io_cmd;
        uint8_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_link_t      *io_walk_link;
        zio_t           *io_logical;
        zio_transform_t *io_transform_stack;

        zio_done_func_t *io_ready;
        zio_done_func_t *io_done;
        void            *io_private;
        int64_t         io_prev_space_delta;    
        blkptr_t        io_bp_orig;

        void            *io_data;
        void            *io_orig_data;
        uint64_t        io_size;
        uint64_t        io_orig_size;

        vdev_t          *io_vd;
        void            *io_vsd;
        const zio_vsd_ops_t *io_vsd_ops;

        uint64_t        io_offset;
        uint64_t        io_deadline;
        avl_node_t      io_offset_node;
        avl_node_t      io_deadline_node;
        avl_tree_t      *io_vdev_tree;

        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;
        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_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;

        zio_cksum_report_t *io_cksum_report;
        uint64_t        io_ena;
#ifdef _KERNEL

        struct ostask   io_task;
#endif
        avl_node_t      io_trim_node;
        list_node_t     io_trim_link;
};

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

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

extern zio_t *zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, void *data,
    uint64_t size, zio_done_func_t *done, void *priv,
    int priority, enum zio_flag flags, const zbookmark_t *zb);

extern zio_t *zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
    void *data, uint64_t size, const zio_prop_t *zp,
    zio_done_func_t *ready, zio_done_func_t *done, void *priv,
    int priority, enum zio_flag flags, const zbookmark_t *zb);

extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
    void *data, uint64_t size, zio_done_func_t *done, void *priv,
    int priority, enum zio_flag flags, zbookmark_t *zb);

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

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 *priv, enum zio_flag flags);

extern zio_t *zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
    uint64_t offset, uint64_t size, zio_done_func_t *done, void *priv,
    int priority, enum zio_flag flags);

extern zio_t *zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
    uint64_t size, void *data, int checksum,
    zio_done_func_t *done, void *priv, int 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, void *data, int checksum,
    zio_done_func_t *done, void *priv, int 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, uint64_t size, enum zio_flag flags);

extern int zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp,
    blkptr_t *old_bp, uint64_t size, boolean_t use_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 zio_t *zio_trim(zio_t *zio, spa_t *spa, vdev_t *vd, uint64_t offset,
    uint64_t size);
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 zio_t *zio_walk_parents(zio_t *cio);
extern zio_t *zio_walk_children(zio_t *pio);
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_resubmit_stage_async(void *);

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

extern zio_t *zio_vdev_delegated_io(vdev_t *vd, uint64_t offset,
    void *data, uint64_t size, int type, int priority,
    enum zio_flag flags, zio_done_func_t *done, void *priv);

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_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(enum zio_compress child,
    enum zio_compress parent);

extern void zio_suspend(spa_t *spa, zio_t *zio);
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_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);

/*
 * Checksum ereport functions
 */
extern void zfs_ereport_start_checksum(spa_t *spa, vdev_t *vd, 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 void *good_data, const void *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);

extern void zfs_ereport_post_checksum(spa_t *spa, vdev_t *vd,
    struct zio *zio, uint64_t offset, uint64_t length,
    const void *good_data, const void *bad_data, struct zio_bad_cksum *info);

extern void spa_handle_ignored_writes(spa_t *spa);

/* zbookmark functions */
boolean_t zbookmark_is_before(const struct dnode_phys *dnp,
    const zbookmark_t *zb1, const zbookmark_t *zb2);

#ifdef  __cplusplus
}
#endif

#endif  /* _ZIO_H */