1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 
  22 /*
  23  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
  25  * Copyright (c) 2012 by Delphix. All rights reserved.
  26  * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
  27  */
  28 
  29 #ifndef _ZIO_H
  30 #define _ZIO_H
  31 
  32 #include <sys/zfs_context.h>
  33 #include <sys/spa.h>
  34 #include <sys/txg.h>
  35 #include <sys/avl.h>
  36 #include <sys/fs/zfs.h>
  37 #include <sys/zio_impl.h>
  38 
  39 #ifdef  __cplusplus
  40 extern "C" {
  41 #endif
  42 
  43 /*
  44  * Embedded checksum
  45  */
  46 #define ZEC_MAGIC       0x210da7ab10c7a11ULL
  47 
  48 typedef struct zio_eck {
  49         uint64_t        zec_magic;      /* for validation, endianness   */
  50         zio_cksum_t     zec_cksum;      /* 256-bit checksum             */
  51 } zio_eck_t;
  52 
  53 /*
  54  * Gang block headers are self-checksumming and contain an array
  55  * of block pointers.
  56  */
  57 #define SPA_GANGBLOCKSIZE       SPA_MINBLOCKSIZE
  58 #define SPA_GBH_NBLKPTRS        ((SPA_GANGBLOCKSIZE - \
  59         sizeof (zio_eck_t)) / sizeof (blkptr_t))
  60 #define SPA_GBH_FILLER          ((SPA_GANGBLOCKSIZE - \
  61         sizeof (zio_eck_t) - \
  62         (SPA_GBH_NBLKPTRS * sizeof (blkptr_t))) /\
  63         sizeof (uint64_t))
  64 
  65 typedef struct zio_gbh {
  66         blkptr_t                zg_blkptr[SPA_GBH_NBLKPTRS];
  67         uint64_t                zg_filler[SPA_GBH_FILLER];
  68         zio_eck_t               zg_tail;
  69 } zio_gbh_phys_t;
  70 
  71 enum zio_checksum {
  72         ZIO_CHECKSUM_INHERIT = 0,
  73         ZIO_CHECKSUM_ON,
  74         ZIO_CHECKSUM_OFF,
  75         ZIO_CHECKSUM_LABEL,
  76         ZIO_CHECKSUM_GANG_HEADER,
  77         ZIO_CHECKSUM_ZILOG,
  78         ZIO_CHECKSUM_FLETCHER_2,
  79         ZIO_CHECKSUM_FLETCHER_4,
  80         ZIO_CHECKSUM_SHA256,
  81         ZIO_CHECKSUM_ZILOG2,
  82         ZIO_CHECKSUM_FUNCTIONS
  83 };
  84 
  85 #define ZIO_CHECKSUM_ON_VALUE   ZIO_CHECKSUM_FLETCHER_4
  86 #define ZIO_CHECKSUM_DEFAULT    ZIO_CHECKSUM_ON
  87 
  88 #define ZIO_CHECKSUM_MASK       0xffULL
  89 #define ZIO_CHECKSUM_VERIFY     (1 << 8)
  90 
  91 #define ZIO_DEDUPCHECKSUM       ZIO_CHECKSUM_SHA256
  92 #define ZIO_DEDUPDITTO_MIN      100
  93 
  94 enum zio_compress {
  95         ZIO_COMPRESS_INHERIT = 0,
  96         ZIO_COMPRESS_ON,
  97         ZIO_COMPRESS_OFF,
  98         ZIO_COMPRESS_LZJB,
  99         ZIO_COMPRESS_EMPTY,
 100         ZIO_COMPRESS_GZIP_1,
 101         ZIO_COMPRESS_GZIP_2,
 102         ZIO_COMPRESS_GZIP_3,
 103         ZIO_COMPRESS_GZIP_4,
 104         ZIO_COMPRESS_GZIP_5,
 105         ZIO_COMPRESS_GZIP_6,
 106         ZIO_COMPRESS_GZIP_7,
 107         ZIO_COMPRESS_GZIP_8,
 108         ZIO_COMPRESS_GZIP_9,
 109         ZIO_COMPRESS_ZLE,
 110         ZIO_COMPRESS_LZ4,
 111         ZIO_COMPRESS_LZ4HC,
 112         ZIO_COMPRESS_FUNCTIONS
 113 };
 114 
 115 /* N.B. when altering this value, also change BOOTFS_COMPRESS_VALID below */
 116 #define ZIO_COMPRESS_ON_VALUE   ZIO_COMPRESS_LZJB
 117 #define ZIO_COMPRESS_DEFAULT    ZIO_COMPRESS_OFF
 118 
 119 #define BOOTFS_COMPRESS_VALID(compress)                 \
 120         ((compress) == ZIO_COMPRESS_LZJB ||             \
 121         (compress) == ZIO_COMPRESS_LZ4HC ||             \
 122         (compress) == ZIO_COMPRESS_LZ4 ||               \
 123         ((compress) == ZIO_COMPRESS_ON &&               \
 124         ZIO_COMPRESS_ON_VALUE == ZIO_COMPRESS_LZJB) ||  \
 125         (compress) == ZIO_COMPRESS_OFF)
 126 
 127 #define ZIO_FAILURE_MODE_WAIT           0
 128 #define ZIO_FAILURE_MODE_CONTINUE       1
 129 #define ZIO_FAILURE_MODE_PANIC          2
 130 
 131 #define ZIO_PRIORITY_NOW                (zio_priority_table[0])
 132 #define ZIO_PRIORITY_SYNC_READ          (zio_priority_table[1])
 133 #define ZIO_PRIORITY_SYNC_WRITE         (zio_priority_table[2])
 134 #define ZIO_PRIORITY_LOG_WRITE          (zio_priority_table[3])
 135 #define ZIO_PRIORITY_CACHE_FILL         (zio_priority_table[4])
 136 #define ZIO_PRIORITY_AGG                (zio_priority_table[5])
 137 #define ZIO_PRIORITY_FREE               (zio_priority_table[6])
 138 #define ZIO_PRIORITY_ASYNC_WRITE        (zio_priority_table[7])
 139 #define ZIO_PRIORITY_ASYNC_READ         (zio_priority_table[8])
 140 #define ZIO_PRIORITY_RESILVER           (zio_priority_table[9])
 141 #define ZIO_PRIORITY_SCRUB              (zio_priority_table[10])
 142 #define ZIO_PRIORITY_DDT_PREFETCH       (zio_priority_table[11])
 143 #define ZIO_PRIORITY_TABLE_SIZE         12
 144 
 145 #define ZIO_PIPELINE_CONTINUE           0x100
 146 #define ZIO_PIPELINE_STOP               0x101
 147 
 148 enum zio_flag {
 149         /*
 150          * Flags inherited by gang, ddt, and vdev children,
 151          * and that must be equal for two zios to aggregate
 152          */
 153         ZIO_FLAG_DONT_AGGREGATE = 1 << 0,
 154         ZIO_FLAG_IO_REPAIR      = 1 << 1,
 155         ZIO_FLAG_SELF_HEAL      = 1 << 2,
 156         ZIO_FLAG_RESILVER       = 1 << 3,
 157         ZIO_FLAG_SCRUB          = 1 << 4,
 158         ZIO_FLAG_SCAN_THREAD    = 1 << 5,
 159 
 160 #define ZIO_FLAG_AGG_INHERIT    (ZIO_FLAG_CANFAIL - 1)
 161 
 162         /*
 163          * Flags inherited by ddt, gang, and vdev children.
 164          */
 165         ZIO_FLAG_CANFAIL        = 1 << 6, /* must be first for INHERIT */
 166         ZIO_FLAG_SPECULATIVE    = 1 << 7,
 167         ZIO_FLAG_CONFIG_WRITER  = 1 << 8,
 168         ZIO_FLAG_DONT_RETRY     = 1 << 9,
 169         ZIO_FLAG_DONT_CACHE     = 1 << 10,
 170         ZIO_FLAG_NODATA         = 1 << 11,
 171         ZIO_FLAG_INDUCE_DAMAGE  = 1 << 12,
 172 
 173 #define ZIO_FLAG_DDT_INHERIT    (ZIO_FLAG_IO_RETRY - 1)
 174 #define ZIO_FLAG_GANG_INHERIT   (ZIO_FLAG_IO_RETRY - 1)
 175 
 176         /*
 177          * Flags inherited by vdev children.
 178          */
 179         ZIO_FLAG_IO_RETRY       = 1 << 13,        /* must be first for INHERIT */
 180         ZIO_FLAG_PROBE          = 1 << 14,
 181         ZIO_FLAG_TRYHARD        = 1 << 15,
 182         ZIO_FLAG_OPTIONAL       = 1 << 16,
 183 
 184 #define ZIO_FLAG_VDEV_INHERIT   (ZIO_FLAG_DONT_QUEUE - 1)
 185 
 186         /*
 187          * Flags not inherited by any children.
 188          */
 189         ZIO_FLAG_DONT_QUEUE     = 1 << 17,        /* must be first for INHERIT */
 190         ZIO_FLAG_DONT_PROPAGATE = 1 << 18,
 191         ZIO_FLAG_IO_BYPASS      = 1 << 19,
 192         ZIO_FLAG_IO_REWRITE     = 1 << 20,
 193         ZIO_FLAG_RAW            = 1 << 21,
 194         ZIO_FLAG_GANG_CHILD     = 1 << 22,
 195         ZIO_FLAG_DDT_CHILD      = 1 << 23,
 196         ZIO_FLAG_GODFATHER      = 1 << 24,
 197         ZIO_FLAG_NOPWRITE       = 1 << 25,
 198         ZIO_FLAG_REEXECUTED     = 1 << 26,
 199 };
 200 
 201 #define ZIO_FLAG_MUSTSUCCEED            0
 202 
 203 #define ZIO_DDT_CHILD_FLAGS(zio)                                \
 204         (((zio)->io_flags & ZIO_FLAG_DDT_INHERIT) |              \
 205         ZIO_FLAG_DDT_CHILD | ZIO_FLAG_CANFAIL)
 206 
 207 #define ZIO_GANG_CHILD_FLAGS(zio)                               \
 208         (((zio)->io_flags & ZIO_FLAG_GANG_INHERIT) |             \
 209         ZIO_FLAG_GANG_CHILD | ZIO_FLAG_CANFAIL)
 210 
 211 #define ZIO_VDEV_CHILD_FLAGS(zio)                               \
 212         (((zio)->io_flags & ZIO_FLAG_VDEV_INHERIT) |             \
 213         ZIO_FLAG_CANFAIL)
 214 
 215 enum zio_child {
 216         ZIO_CHILD_VDEV = 0,
 217         ZIO_CHILD_GANG,
 218         ZIO_CHILD_DDT,
 219         ZIO_CHILD_LOGICAL,
 220         ZIO_CHILD_TYPES
 221 };
 222 
 223 enum zio_wait_type {
 224         ZIO_WAIT_READY = 0,
 225         ZIO_WAIT_DONE,
 226         ZIO_WAIT_TYPES
 227 };
 228 
 229 /*
 230  * We'll take the unused errnos, 'EBADE' and 'EBADR' (from the Convergent
 231  * graveyard) to indicate checksum errors and fragmentation.
 232  */
 233 #define ECKSUM  EBADE
 234 #define EFRAGS  EBADR
 235 
 236 typedef void zio_done_func_t(zio_t *zio);
 237 
 238 extern uint8_t zio_priority_table[ZIO_PRIORITY_TABLE_SIZE];
 239 extern char *zio_type_name[ZIO_TYPES];
 240 
 241 /*
 242  * A bookmark is a four-tuple <objset, object, level, blkid> that uniquely
 243  * identifies any block in the pool.  By convention, the meta-objset (MOS)
 244  * is objset 0, and the meta-dnode is object 0.  This covers all blocks
 245  * except root blocks and ZIL blocks, which are defined as follows:
 246  *
 247  * Root blocks (objset_phys_t) are object 0, level -1:  <objset, 0, -1, 0>.
 248  * ZIL blocks are bookmarked <objset, 0, -2, blkid == ZIL sequence number>.
 249  * dmu_sync()ed ZIL data blocks are bookmarked <objset, object, -2, blkid>.
 250  *
 251  * Note: this structure is called a bookmark because its original purpose
 252  * was to remember where to resume a pool-wide traverse.
 253  *
 254  * Note: this structure is passed between userland and the kernel.
 255  * Therefore it must not change size or alignment between 32/64 bit
 256  * compilation options.
 257  */
 258 typedef struct zbookmark {
 259         uint64_t        zb_objset;
 260         uint64_t        zb_object;
 261         int64_t         zb_level;
 262         uint64_t        zb_blkid;
 263 } zbookmark_t;
 264 
 265 #define SET_BOOKMARK(zb, objset, object, level, blkid)  \
 266 {                                                       \
 267         (zb)->zb_objset = objset;                       \
 268         (zb)->zb_object = object;                       \
 269         (zb)->zb_level = level;                         \
 270         (zb)->zb_blkid = blkid;                         \
 271 }
 272 
 273 #define ZB_DESTROYED_OBJSET     (-1ULL)
 274 
 275 #define ZB_ROOT_OBJECT          (0ULL)
 276 #define ZB_ROOT_LEVEL           (-1LL)
 277 #define ZB_ROOT_BLKID           (0ULL)
 278 
 279 #define ZB_ZIL_OBJECT           (0ULL)
 280 #define ZB_ZIL_LEVEL            (-2LL)
 281 
 282 #define ZB_IS_ZERO(zb)                                          \
 283         ((zb)->zb_objset == 0 && (zb)->zb_object == 0 &&  \
 284         (zb)->zb_level == 0 && (zb)->zb_blkid == 0)
 285 #define ZB_IS_ROOT(zb)                          \
 286         ((zb)->zb_object == ZB_ROOT_OBJECT &&        \
 287         (zb)->zb_level == ZB_ROOT_LEVEL &&   \
 288         (zb)->zb_blkid == ZB_ROOT_BLKID)
 289 
 290 typedef struct zio_prop {
 291         enum zio_checksum       zp_checksum;
 292         enum zio_compress       zp_compress;
 293         dmu_object_type_t       zp_type;
 294         uint8_t                 zp_level;
 295         uint8_t                 zp_copies;
 296         boolean_t               zp_dedup;
 297         boolean_t               zp_dedup_verify;
 298         boolean_t               zp_nopwrite;
 299 } zio_prop_t;
 300 
 301 typedef struct zio_cksum_report zio_cksum_report_t;
 302 
 303 typedef void zio_cksum_finish_f(zio_cksum_report_t *rep,
 304     const void *good_data);
 305 typedef void zio_cksum_free_f(void *cbdata, size_t size);
 306 
 307 struct zio_bad_cksum;                           /* defined in zio_checksum.h */
 308 struct dnode_phys;
 309 
 310 struct zio_cksum_report {
 311         struct zio_cksum_report *zcr_next;
 312         nvlist_t                *zcr_ereport;
 313         nvlist_t                *zcr_detector;
 314         void                    *zcr_cbdata;
 315         size_t                  zcr_cbinfo;     /* passed to zcr_free() */
 316         uint64_t                zcr_align;
 317         uint64_t                zcr_length;
 318         zio_cksum_finish_f      *zcr_finish;
 319         zio_cksum_free_f        *zcr_free;
 320 
 321         /* internal use only */
 322         struct zio_bad_cksum    *zcr_ckinfo;    /* information from failure */
 323 };
 324 
 325 typedef void zio_vsd_cksum_report_f(zio_t *zio, zio_cksum_report_t *zcr,
 326     void *arg);
 327 
 328 zio_vsd_cksum_report_f  zio_vsd_default_cksum_report;
 329 
 330 typedef struct zio_vsd_ops {
 331         zio_done_func_t         *vsd_free;
 332         zio_vsd_cksum_report_f  *vsd_cksum_report;
 333 } zio_vsd_ops_t;
 334 
 335 typedef struct zio_gang_node {
 336         zio_gbh_phys_t          *gn_gbh;
 337         struct zio_gang_node    *gn_child[SPA_GBH_NBLKPTRS];
 338 } zio_gang_node_t;
 339 
 340 typedef zio_t *zio_gang_issue_func_t(zio_t *zio, blkptr_t *bp,
 341     zio_gang_node_t *gn, void *data);
 342 
 343 typedef void zio_transform_func_t(zio_t *zio, void *data, uint64_t size);
 344 
 345 typedef struct zio_transform {
 346         void                    *zt_orig_data;
 347         uint64_t                zt_orig_size;
 348         uint64_t                zt_bufsize;
 349         zio_transform_func_t    *zt_transform;
 350         struct zio_transform    *zt_next;
 351 } zio_transform_t;
 352 
 353 typedef int zio_pipe_stage_t(zio_t *zio);
 354 
 355 /*
 356  * The io_reexecute flags are distinct from io_flags because the child must
 357  * be able to propagate them to the parent.  The normal io_flags are local
 358  * to the zio, not protected by any lock, and not modifiable by children;
 359  * the reexecute flags are protected by io_lock, modifiable by children,
 360  * and always propagated -- even when ZIO_FLAG_DONT_PROPAGATE is set.
 361  */
 362 #define ZIO_REEXECUTE_NOW       0x01
 363 #define ZIO_REEXECUTE_SUSPEND   0x02
 364 
 365 typedef struct zio_link {
 366         zio_t           *zl_parent;
 367         zio_t           *zl_child;
 368         list_node_t     zl_parent_node;
 369         list_node_t     zl_child_node;
 370 } zio_link_t;
 371 
 372 struct zio {
 373         /* Core information about this I/O */
 374         zbookmark_t     io_bookmark;
 375         zio_prop_t      io_prop;
 376         zio_type_t      io_type;
 377         enum zio_child  io_child_type;
 378         int             io_cmd;
 379         uint8_t         io_priority;
 380         uint8_t         io_reexecute;
 381         uint8_t         io_state[ZIO_WAIT_TYPES];
 382         uint64_t        io_txg;
 383         spa_t           *io_spa;
 384         blkptr_t        *io_bp;
 385         blkptr_t        *io_bp_override;
 386         blkptr_t        io_bp_copy;
 387         list_t          io_parent_list;
 388         list_t          io_child_list;
 389         zio_link_t      *io_walk_link;
 390         zio_t           *io_logical;
 391         zio_transform_t *io_transform_stack;
 392 
 393         /* Callback info */
 394         zio_done_func_t *io_ready;
 395         zio_done_func_t *io_done;
 396         void            *io_private;
 397         int64_t         io_prev_space_delta;    /* DMU private */
 398         blkptr_t        io_bp_orig;
 399 
 400         /* Data represented by this I/O */
 401         void            *io_data;
 402         void            *io_orig_data;
 403         uint64_t        io_size;
 404         uint64_t        io_orig_size;
 405 
 406         /* Stuff for the vdev stack */
 407         vdev_t          *io_vd;
 408         void            *io_vsd;
 409         const zio_vsd_ops_t *io_vsd_ops;
 410 
 411         uint64_t        io_offset;
 412         uint64_t        io_deadline;
 413         uint64_t        io_timestamp;
 414         avl_node_t      io_offset_node;
 415         avl_node_t      io_deadline_node;
 416         avl_tree_t      *io_vdev_tree;
 417 
 418         /* Internal pipeline state */
 419         enum zio_flag   io_flags;
 420         enum zio_stage  io_stage;
 421         enum zio_stage  io_pipeline;
 422         enum zio_flag   io_orig_flags;
 423         enum zio_stage  io_orig_stage;
 424         enum zio_stage  io_orig_pipeline;
 425         int             io_error;
 426         int             io_child_error[ZIO_CHILD_TYPES];
 427         uint64_t        io_children[ZIO_CHILD_TYPES][ZIO_WAIT_TYPES];
 428         uint64_t        io_child_count;
 429         uint64_t        io_parent_count;
 430         uint64_t        *io_stall;
 431         zio_t           *io_gang_leader;
 432         zio_gang_node_t *io_gang_tree;
 433         void            *io_executor;
 434         void            *io_waiter;
 435         kmutex_t        io_lock;
 436         kcondvar_t      io_cv;
 437 
 438         /* FMA state */
 439         zio_cksum_report_t *io_cksum_report;
 440         uint64_t        io_ena;
 441 
 442         /* Taskq dispatching state */
 443         taskq_ent_t     io_tqent;
 444 };
 445 
 446 extern zio_t *zio_null(zio_t *pio, spa_t *spa, vdev_t *vd,
 447     zio_done_func_t *done, void *private, enum zio_flag flags);
 448 
 449 extern zio_t *zio_root(spa_t *spa,
 450     zio_done_func_t *done, void *private, enum zio_flag flags);
 451 
 452 extern zio_t *zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, void *data,
 453     uint64_t size, zio_done_func_t *done, void *private,
 454     int priority, enum zio_flag flags, const zbookmark_t *zb);
 455 
 456 extern zio_t *zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
 457     void *data, uint64_t size, const zio_prop_t *zp,
 458     zio_done_func_t *ready, zio_done_func_t *done, void *private,
 459     int priority, enum zio_flag flags, const zbookmark_t *zb);
 460 
 461 extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
 462     void *data, uint64_t size, zio_done_func_t *done, void *private,
 463     int priority, enum zio_flag flags, zbookmark_t *zb);
 464 
 465 extern void zio_write_override(zio_t *zio, blkptr_t *bp, int copies,
 466     boolean_t nopwrite);
 467 
 468 extern void zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp);
 469 
 470 extern zio_t *zio_claim(zio_t *pio, spa_t *spa, uint64_t txg,
 471     const blkptr_t *bp,
 472     zio_done_func_t *done, void *private, enum zio_flag flags);
 473 
 474 extern zio_t *zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
 475     zio_done_func_t *done, void *private, int priority, enum zio_flag flags);
 476 
 477 extern zio_t *zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
 478     uint64_t size, void *data, int checksum,
 479     zio_done_func_t *done, void *private, int priority, enum zio_flag flags,
 480     boolean_t labels);
 481 
 482 extern zio_t *zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
 483     uint64_t size, void *data, int checksum,
 484     zio_done_func_t *done, void *private, int priority, enum zio_flag flags,
 485     boolean_t labels);
 486 
 487 extern zio_t *zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg,
 488     const blkptr_t *bp, enum zio_flag flags);
 489 
 490 extern int zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp,
 491     blkptr_t *old_bp, uint64_t size, boolean_t use_slog);
 492 extern void zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp);
 493 extern void zio_flush(zio_t *zio, vdev_t *vd);
 494 extern void zio_shrink(zio_t *zio, uint64_t size);
 495 
 496 extern int zio_wait(zio_t *zio);
 497 extern void zio_nowait(zio_t *zio);
 498 extern void zio_execute(zio_t *zio);
 499 extern void zio_interrupt(zio_t *zio);
 500 
 501 extern zio_t *zio_walk_parents(zio_t *cio);
 502 extern zio_t *zio_walk_children(zio_t *pio);
 503 extern zio_t *zio_unique_parent(zio_t *cio);
 504 extern void zio_add_child(zio_t *pio, zio_t *cio);
 505 
 506 extern void *zio_buf_alloc(size_t size);
 507 extern void zio_buf_free(void *buf, size_t size);
 508 extern void *zio_data_buf_alloc(size_t size);
 509 extern void zio_data_buf_free(void *buf, size_t size);
 510 
 511 extern void zio_resubmit_stage_async(void *);
 512 
 513 extern zio_t *zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd,
 514     uint64_t offset, void *data, uint64_t size, int type, int priority,
 515     enum zio_flag flags, zio_done_func_t *done, void *private);
 516 
 517 extern zio_t *zio_vdev_delegated_io(vdev_t *vd, uint64_t offset,
 518     void *data, uint64_t size, int type, int priority,
 519     enum zio_flag flags, zio_done_func_t *done, void *private);
 520 
 521 extern void zio_vdev_io_bypass(zio_t *zio);
 522 extern void zio_vdev_io_reissue(zio_t *zio);
 523 extern void zio_vdev_io_redone(zio_t *zio);
 524 
 525 extern void zio_checksum_verified(zio_t *zio);
 526 extern int zio_worst_error(int e1, int e2);
 527 
 528 extern enum zio_checksum zio_checksum_select(enum zio_checksum child,
 529     enum zio_checksum parent);
 530 extern enum zio_checksum zio_checksum_dedup_select(spa_t *spa,
 531     enum zio_checksum child, enum zio_checksum parent);
 532 extern enum zio_compress zio_compress_select(enum zio_compress child,
 533     enum zio_compress parent);
 534 
 535 extern void zio_suspend(spa_t *spa, zio_t *zio);
 536 extern int zio_resume(spa_t *spa);
 537 extern void zio_resume_wait(spa_t *spa);
 538 
 539 /*
 540  * Initial setup and teardown.
 541  */
 542 extern void zio_init(void);
 543 extern void zio_fini(void);
 544 
 545 /*
 546  * Fault injection
 547  */
 548 struct zinject_record;
 549 extern uint32_t zio_injection_enabled;
 550 extern int zio_inject_fault(char *name, int flags, int *id,
 551     struct zinject_record *record);
 552 extern int zio_inject_list_next(int *id, char *name, size_t buflen,
 553     struct zinject_record *record);
 554 extern int zio_clear_fault(int id);
 555 extern void zio_handle_panic_injection(spa_t *spa, char *tag, uint64_t type);
 556 extern int zio_handle_fault_injection(zio_t *zio, int error);
 557 extern int zio_handle_device_injection(vdev_t *vd, zio_t *zio, int error);
 558 extern int zio_handle_label_injection(zio_t *zio, int error);
 559 extern void zio_handle_ignored_writes(zio_t *zio);
 560 extern uint64_t zio_handle_io_delay(zio_t *zio);
 561 
 562 /*
 563  * Checksum ereport functions
 564  */
 565 extern void zfs_ereport_start_checksum(spa_t *spa, vdev_t *vd, struct zio *zio,
 566     uint64_t offset, uint64_t length, void *arg, struct zio_bad_cksum *info);
 567 extern void zfs_ereport_finish_checksum(zio_cksum_report_t *report,
 568     const void *good_data, const void *bad_data, boolean_t drop_if_identical);
 569 
 570 extern void zfs_ereport_send_interim_checksum(zio_cksum_report_t *report);
 571 extern void zfs_ereport_free_checksum(zio_cksum_report_t *report);
 572 
 573 /* If we have the good data in hand, this function can be used */
 574 extern void zfs_ereport_post_checksum(spa_t *spa, vdev_t *vd,
 575     struct zio *zio, uint64_t offset, uint64_t length,
 576     const void *good_data, const void *bad_data, struct zio_bad_cksum *info);
 577 
 578 /* Called from spa_sync(), but primarily an injection handler */
 579 extern void spa_handle_ignored_writes(spa_t *spa);
 580 
 581 /* zbookmark functions */
 582 boolean_t zbookmark_is_before(const struct dnode_phys *dnp,
 583     const zbookmark_t *zb1, const zbookmark_t *zb2);
 584 
 585 #ifdef  __cplusplus
 586 }
 587 #endif
 588 
 589 #endif  /* _ZIO_H */