zfs/sys/zio.h

	zio.h revision e09fa4dacfb671e707d50a55ae9b5cc191e1b8cb
/*
 * 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.
 */

#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/fs/zfs.h>
#include <sys/zio_impl.h>

#ifdef  __cplusplus
extern "C" {
#endif

#define ZBT_MAGIC   0x210da7ab10c7a11ULL    /* zio data bloc tail */

typedef struct zio_block_tail {
    uint64_t    zbt_magic;  /* for validation, endianness   */
    zio_cksum_t zbt_cksum;  /* 256-bit checksum     */
} zio_block_tail_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_block_tail_t)) / sizeof (blkptr_t))
#define SPA_GBH_FILLER      ((SPA_GANGBLOCKSIZE - \
    sizeof (zio_block_tail_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_block_tail_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_FUNCTIONS
};

#define ZIO_CHECKSUM_ON_VALUE   ZIO_CHECKSUM_FLETCHER_4
#define ZIO_CHECKSUM_DEFAULT    ZIO_CHECKSUM_ON

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_FUNCTIONS
};

#define ZIO_COMPRESS_ON_VALUE   ZIO_COMPRESS_LZJB
#define ZIO_COMPRESS_DEFAULT    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_ASYNC_READ     (zio_priority_table[3])
#define ZIO_PRIORITY_ASYNC_WRITE    (zio_priority_table[4])
#define ZIO_PRIORITY_FREE       (zio_priority_table[5])
#define ZIO_PRIORITY_CACHE_FILL     (zio_priority_table[6])
#define ZIO_PRIORITY_LOG_WRITE      (zio_priority_table[7])
#define ZIO_PRIORITY_RESILVER       (zio_priority_table[8])
#define ZIO_PRIORITY_SCRUB      (zio_priority_table[9])
#define ZIO_PRIORITY_TABLE_SIZE     10

#define ZIO_FLAG_MUSTSUCCEED        0x000000
#define ZIO_FLAG_CANFAIL        0x000001
#define ZIO_FLAG_SPECULATIVE        0x000002
#define ZIO_FLAG_CONFIG_WRITER      0x000004
#define ZIO_FLAG_DONT_RETRY     0x000008

#define ZIO_FLAG_DONT_CACHE     0x000010
#define ZIO_FLAG_DONT_QUEUE     0x000020
#define ZIO_FLAG_DONT_AGGREGATE     0x000040
#define ZIO_FLAG_DONT_PROPAGATE     0x000080

#define ZIO_FLAG_IO_BYPASS      0x000100
#define ZIO_FLAG_IO_REPAIR      0x000200
#define ZIO_FLAG_IO_RETRY       0x000400
#define ZIO_FLAG_IO_REWRITE     0x000800

#define ZIO_FLAG_SELF_HEAL      0x001000
#define ZIO_FLAG_RESILVER       0x002000
#define ZIO_FLAG_SCRUB          0x004000
#define ZIO_FLAG_SCRUB_THREAD       0x008000

#define ZIO_FLAG_PROBE          0x010000
#define ZIO_FLAG_GANG_CHILD     0x020000
#define ZIO_FLAG_RAW            0x040000
#define ZIO_FLAG_GODFATHER      0x080000

#define ZIO_FLAG_TRYHARD        0x100000
#define ZIO_FLAG_NODATA         0x200000
#define ZIO_FLAG_OPTIONAL       0x400000

#define ZIO_FLAG_GANG_INHERIT       \
    (ZIO_FLAG_CANFAIL |     \
    ZIO_FLAG_SPECULATIVE |      \
    ZIO_FLAG_CONFIG_WRITER |    \
    ZIO_FLAG_DONT_RETRY |       \
    ZIO_FLAG_DONT_CACHE |       \
    ZIO_FLAG_DONT_AGGREGATE |   \
    ZIO_FLAG_SELF_HEAL |        \
    ZIO_FLAG_RESILVER |     \
    ZIO_FLAG_SCRUB |        \
    ZIO_FLAG_SCRUB_THREAD)

#define ZIO_FLAG_VDEV_INHERIT       \
    (ZIO_FLAG_GANG_INHERIT |    \
    ZIO_FLAG_IO_REPAIR |        \
    ZIO_FLAG_IO_RETRY |     \
    ZIO_FLAG_PROBE |        \
    ZIO_FLAG_TRYHARD |      \
    ZIO_FLAG_NODATA |       \
    ZIO_FLAG_OPTIONAL)

#define ZIO_FLAG_AGG_INHERIT        \
    (ZIO_FLAG_DONT_AGGREGATE |  \
    ZIO_FLAG_IO_REPAIR |        \
    ZIO_FLAG_SELF_HEAL |        \
    ZIO_FLAG_RESILVER |     \
    ZIO_FLAG_SCRUB |        \
    ZIO_FLAG_SCRUB_THREAD)

#define ZIO_PIPELINE_CONTINUE       0x100
#define ZIO_PIPELINE_STOP       0x101

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

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

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 struct zio zio_t;
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];

/*
 * 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, the meta-dnode is object 0, the root block (osphys_t) is
 * level -1 of the meta-dnode, and intent log blocks (which are chained
 * off the root block) have blkid == sequence number.  In summary:
 *
 *  mos is objset 0
 *  meta-dnode is object 0
 *  root block is <objset, 0, -1, 0>
 *  intent log is <objset, 0, -1, ZIL sequence number>
 *
 * Note: this structure is called a bookmark because its first purpose was
 * to remember where to resume a pool-wide traverse.  The absolute ordering
 * for block visitation during traversal is defined in compare_bookmark().
 *
 * Note: this structure is passed between userland and the kernel.
 * Therefore it must not change size or alignment between 32/64 bit
 * compilation options.
 */
typedef struct zbookmark {
    uint64_t    zb_objset;
    uint64_t    zb_object;
    int64_t     zb_level;
    uint64_t    zb_blkid;
} zbookmark_t;

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_ndvas;
} zio_prop_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);

/*
 * 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

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_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_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;

    /* Callback info */
    zio_done_func_t *io_ready;
    zio_done_func_t *io_done;
    void        *io_private;
    blkptr_t    io_bp_orig;

    /* Data represented by this I/O */
    void        *io_data;
    uint64_t    io_size;

    /* Stuff for the vdev stack */
    vdev_t      *io_vd;
    void        *io_vsd;
    zio_done_func_t *io_vsd_free;
    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;

    /* Internal pipeline state */
    int     io_flags;
    zio_stage_t io_stage;
    uint32_t    io_pipeline;
    int     io_orig_flags;
    zio_stage_t io_orig_stage;
    uint32_t    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_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;

    /* FMA state */
    uint64_t    io_ena;
};

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

extern zio_t *zio_root(spa_t *spa,
    zio_done_func_t *done, void *private, int 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 *private,
    int priority, int 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, zio_prop_t *zp,
    zio_done_func_t *ready, zio_done_func_t *done, void *private,
    int priority, int 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 *private,
    int priority, int flags, zbookmark_t *zb);

extern void zio_skip_write(zio_t *zio);

extern zio_t *zio_free(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
    zio_done_func_t *done, void *private, int flags);

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

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

extern int zio_alloc_blk(spa_t *spa, uint64_t size, blkptr_t *new_bp,
    blkptr_t *old_bp, uint64_t txg, boolean_t bypass_slog);
extern void zio_free_blk(spa_t *spa, blkptr_t *bp, uint64_t txg);
extern void zio_flush(zio_t *zio, vdev_t *vd);

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,
    int flags, zio_done_func_t *done, void *private);

extern zio_t *zio_vdev_delegated_io(vdev_t *vd, uint64_t offset,
    void *data, uint64_t size, int type, int priority,
    int 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_checksum_verified(zio_t *zio);
extern int zio_worst_error(int e1, int e2);

extern uint8_t zio_checksum_select(uint8_t child, uint8_t parent);
extern uint8_t zio_compress_select(uint8_t child, uint8_t 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 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);

#ifdef  __cplusplus
}
#endif

#endif  /* _ZIO_H */