include/sys/zio.h

   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  */
  25 /*
  26  * Copyright 2011 Nexenta Systems, Inc. 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_FUNCTIONS
 111 };
 112
 113 #define ZIO_COMPRESS_ON_VALUE   ZIO_COMPRESS_LZJB
 114 #define ZIO_COMPRESS_DEFAULT    ZIO_COMPRESS_OFF
 115
 116 #define BOOTFS_COMPRESS_VALID(compress)                 \
 117         ((compress) == ZIO_COMPRESS_LZJB ||             \
 118         ((compress) == ZIO_COMPRESS_ON &&               \
 119         ZIO_COMPRESS_ON_VALUE == ZIO_COMPRESS_LZJB) ||  \
 120         (compress) == ZIO_COMPRESS_OFF)
 121
 122 /*
 123  * Default Linux timeout for a sd device.
 124  */
 125 #define ZIO_DELAY_MAX                   (30 * MILLISEC)
 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 };
 198
 199 #define ZIO_FLAG_MUSTSUCCEED            0
 200
 201 #define ZIO_DDT_CHILD_FLAGS(zio)                                \
 202         (((zio)->io_flags & ZIO_FLAG_DDT_INHERIT) |             \
 203         ZIO_FLAG_DDT_CHILD | ZIO_FLAG_CANFAIL)
 204
 205 #define ZIO_GANG_CHILD_FLAGS(zio)                               \
 206         (((zio)->io_flags & ZIO_FLAG_GANG_INHERIT) |            \
 207         ZIO_FLAG_GANG_CHILD | ZIO_FLAG_CANFAIL)
 208
 209 #define ZIO_VDEV_CHILD_FLAGS(zio)                               \
 210         (((zio)->io_flags & ZIO_FLAG_VDEV_INHERIT) |            \
 211         ZIO_FLAG_CANFAIL)
 212
 213 enum zio_child {
 214         ZIO_CHILD_VDEV = 0,
 215         ZIO_CHILD_GANG,
 216         ZIO_CHILD_DDT,
 217         ZIO_CHILD_LOGICAL,
 218         ZIO_CHILD_TYPES
 219 };
 220
 221 enum zio_wait_type {
 222         ZIO_WAIT_READY = 0,
 223         ZIO_WAIT_DONE,
 224         ZIO_WAIT_TYPES
 225 };
 226
 227 /*
 228  * We'll take the unused errnos, 'EBADE' and 'EBADR' (from the Convergent
 229  * graveyard) to indicate checksum errors and fragmentation.
 230  */
 231 #define ECKSUM  EBADE
 232 #define EFRAGS  EBADR
 233
 234 typedef void zio_done_func_t(zio_t *zio);
 235
 236 extern uint8_t zio_priority_table[ZIO_PRIORITY_TABLE_SIZE];
 237 extern char *zio_type_name[ZIO_TYPES];
 238
 239 /*
 240  * A bookmark is a four-tuple <objset, object, level, blkid> that uniquely
 241  * identifies any block in the pool.  By convention, the meta-objset (MOS)
 242  * is objset 0, and the meta-dnode is object 0.  This covers all blocks
 243  * except root blocks and ZIL blocks, which are defined as follows:
 244  *
 245  * Root blocks (objset_phys_t) are object 0, level -1:  <objset, 0, -1, 0>.
 246  * ZIL blocks are bookmarked <objset, 0, -2, blkid == ZIL sequence number>.
 247  * dmu_sync()ed ZIL data blocks are bookmarked <objset, object, -2, blkid>.
 248  *
 249  * Note: this structure is called a bookmark because its original purpose
 250  * was to remember where to resume a pool-wide traverse.
 251  *
 252  * Note: this structure is passed between userland and the kernel.
 253  * Therefore it must not change size or alignment between 32/64 bit
 254  * compilation options.
 255  */
 256 typedef struct zbookmark {
 257         uint64_t        zb_objset;
 258         uint64_t        zb_object;
 259         int64_t         zb_level;
 260         uint64_t        zb_blkid;
 261 } zbookmark_t;
 262
 263 #define SET_BOOKMARK(zb, objset, object, level, blkid)  \
 264 {                                                       \
 265         (zb)->zb_objset = objset;                       \
 266         (zb)->zb_object = object;                       \
 267         (zb)->zb_level = level;                         \
 268         (zb)->zb_blkid = blkid;                         \
 269 }
 270
 271 #define ZB_DESTROYED_OBJSET     (-1ULL)
 272
 273 #define ZB_ROOT_OBJECT          (0ULL)
 274 #define ZB_ROOT_LEVEL           (-1LL)
 275 #define ZB_ROOT_BLKID           (0ULL)
 276
 277 #define ZB_ZIL_OBJECT           (0ULL)
 278 #define ZB_ZIL_LEVEL            (-2LL)
 279
 280 typedef struct zio_prop {
 281         enum zio_checksum       zp_checksum;
 282         enum zio_compress       zp_compress;
 283         dmu_object_type_t       zp_type;
 284         uint8_t                 zp_level;
 285         uint8_t                 zp_copies;
 286         uint8_t                 zp_dedup;
 287         uint8_t                 zp_dedup_verify;
 288 } zio_prop_t;
 289
 290 typedef struct zio_cksum_report zio_cksum_report_t;
 291
 292 typedef void zio_cksum_finish_f(zio_cksum_report_t *rep,
 293     const void *good_data);
 294 typedef void zio_cksum_free_f(void *cbdata, size_t size);
 295
 296 struct zio_bad_cksum;                           /* defined in zio_checksum.h */
 297
 298 struct zio_cksum_report {
 299         struct zio_cksum_report *zcr_next;
 300         nvlist_t                *zcr_ereport;
 301         nvlist_t                *zcr_detector;
 302         void                    *zcr_cbdata;
 303         size_t                  zcr_cbinfo;     /* passed to zcr_free() */
 304         uint64_t                zcr_align;
 305         uint64_t                zcr_length;
 306         zio_cksum_finish_f      *zcr_finish;
 307         zio_cksum_free_f        *zcr_free;
 308
 309         /* internal use only */
 310         struct zio_bad_cksum    *zcr_ckinfo;    /* information from failure */
 311 };
 312
 313 typedef void zio_vsd_cksum_report_f(zio_t *zio, zio_cksum_report_t *zcr,
 314     void *arg);
 315
 316 zio_vsd_cksum_report_f  zio_vsd_default_cksum_report;
 317
 318 typedef struct zio_vsd_ops {
 319         zio_done_func_t         *vsd_free;
 320         zio_vsd_cksum_report_f  *vsd_cksum_report;
 321 } zio_vsd_ops_t;
 322
 323 typedef struct zio_gang_node {
 324         zio_gbh_phys_t          *gn_gbh;
 325         struct zio_gang_node    *gn_child[SPA_GBH_NBLKPTRS];
 326 } zio_gang_node_t;
 327
 328 typedef zio_t *zio_gang_issue_func_t(zio_t *zio, blkptr_t *bp,
 329     zio_gang_node_t *gn, void *data);
 330
 331 typedef void zio_transform_func_t(zio_t *zio, void *data, uint64_t size);
 332
 333 typedef struct zio_transform {
 334         void                    *zt_orig_data;
 335         uint64_t                zt_orig_size;
 336         uint64_t                zt_bufsize;
 337         zio_transform_func_t    *zt_transform;
 338         struct zio_transform    *zt_next;
 339 } zio_transform_t;
 340
 341 typedef int zio_pipe_stage_t(zio_t *zio);
 342
 343 /*
 344  * The io_reexecute flags are distinct from io_flags because the child must
 345  * be able to propagate them to the parent.  The normal io_flags are local
 346  * to the zio, not protected by any lock, and not modifiable by children;
 347  * the reexecute flags are protected by io_lock, modifiable by children,
 348  * and always propagated -- even when ZIO_FLAG_DONT_PROPAGATE is set.
 349  */
 350 #define ZIO_REEXECUTE_NOW       0x01
 351 #define ZIO_REEXECUTE_SUSPEND   0x02
 352
 353 typedef struct zio_link {
 354         zio_t           *zl_parent;
 355         zio_t           *zl_child;
 356         list_node_t     zl_parent_node;
 357         list_node_t     zl_child_node;
 358 } zio_link_t;
 359
 360 struct zio {
 361         /* Core information about this I/O */
 362         zbookmark_t     io_bookmark;
 363         zio_prop_t      io_prop;
 364         zio_type_t      io_type;
 365         enum zio_child  io_child_type;
 366         int             io_cmd;
 367         uint8_t         io_priority;
 368         uint8_t         io_reexecute;
 369         uint8_t         io_state[ZIO_WAIT_TYPES];
 370         uint64_t        io_txg;
 371         spa_t           *io_spa;
 372         blkptr_t        *io_bp;
 373         blkptr_t        *io_bp_override;
 374         blkptr_t        io_bp_copy;
 375         list_t          io_parent_list;
 376         list_t          io_child_list;
 377         zio_link_t      *io_walk_link;
 378         zio_t           *io_logical;
 379         zio_transform_t *io_transform_stack;
 380
 381         /* Callback info */
 382         zio_done_func_t *io_ready;
 383         zio_done_func_t *io_done;
 384         void            *io_private;
 385         int64_t         io_prev_space_delta;    /* DMU private */
 386         blkptr_t        io_bp_orig;
 387
 388         /* Data represented by this I/O */
 389         void            *io_data;
 390         void            *io_orig_data;
 391         uint64_t        io_size;
 392         uint64_t        io_orig_size;
 393
 394         /* Stuff for the vdev stack */
 395         vdev_t          *io_vd;
 396         void            *io_vsd;
 397         const zio_vsd_ops_t *io_vsd_ops;
 398
 399         uint64_t        io_offset;
 400         uint64_t        io_deadline;
 401         avl_node_t      io_offset_node;
 402         avl_node_t      io_deadline_node;
 403         avl_tree_t      *io_vdev_tree;
 404
 405         /* Internal pipeline state */
 406         enum zio_flag   io_flags;
 407         enum zio_stage  io_stage;
 408         enum zio_stage  io_pipeline;
 409         enum zio_flag   io_orig_flags;
 410         enum zio_stage  io_orig_stage;
 411         enum zio_stage  io_orig_pipeline;
 412         uint64_t        io_delay;
 413         int             io_error;
 414         int             io_child_error[ZIO_CHILD_TYPES];
 415         uint64_t        io_children[ZIO_CHILD_TYPES][ZIO_WAIT_TYPES];
 416         uint64_t        io_child_count;
 417         uint64_t        io_parent_count;
 418         uint64_t        *io_stall;
 419         zio_t           *io_gang_leader;
 420         zio_gang_node_t *io_gang_tree;
 421         void            *io_executor;
 422         void            *io_waiter;
 423         kmutex_t        io_lock;
 424         kcondvar_t      io_cv;
 425
 426         /* FMA state */
 427         zio_cksum_report_t *io_cksum_report;
 428         uint64_t        io_ena;
 429
 430         /* Taskq dispatching state */
 431         taskq_ent_t     io_tqent;
 432 };
 433
 434 extern zio_t *zio_null(zio_t *pio, spa_t *spa, vdev_t *vd,
 435     zio_done_func_t *done, void *private, enum zio_flag flags);
 436
 437 extern zio_t *zio_root(spa_t *spa,
 438     zio_done_func_t *done, void *private, enum zio_flag flags);
 439
 440 extern zio_t *zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, void *data,
 441     uint64_t size, zio_done_func_t *done, void *private,
 442     int priority, enum zio_flag flags, const zbookmark_t *zb);
 443
 444 extern zio_t *zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
 445     void *data, uint64_t size, const zio_prop_t *zp,
 446     zio_done_func_t *ready, zio_done_func_t *done, void *private,
 447     int priority, enum zio_flag flags, const zbookmark_t *zb);
 448
 449 extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
 450     void *data, uint64_t size, zio_done_func_t *done, void *private,
 451     int priority, enum zio_flag flags, zbookmark_t *zb);
 452
 453 extern void zio_write_override(zio_t *zio, blkptr_t *bp, int copies);
 454
 455 extern void zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp);
 456
 457 extern zio_t *zio_claim(zio_t *pio, spa_t *spa, uint64_t txg,
 458     const blkptr_t *bp,
 459     zio_done_func_t *done, void *private, enum zio_flag flags);
 460
 461 extern zio_t *zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
 462     zio_done_func_t *done, void *private, int priority, enum zio_flag flags);
 463
 464 extern zio_t *zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
 465     uint64_t size, void *data, int checksum,
 466     zio_done_func_t *done, void *private, int priority, enum zio_flag flags,
 467     boolean_t labels);
 468
 469 extern zio_t *zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
 470     uint64_t size, void *data, int checksum,
 471     zio_done_func_t *done, void *private, int priority, enum zio_flag flags,
 472     boolean_t labels);
 473
 474 extern zio_t *zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg,
 475     const blkptr_t *bp, enum zio_flag flags);
 476
 477 extern int zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp,
 478     blkptr_t *old_bp, uint64_t size, boolean_t use_slog);
 479 extern void zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp);
 480 extern void zio_flush(zio_t *zio, vdev_t *vd);
 481 extern void zio_shrink(zio_t *zio, uint64_t size);
 482
 483 extern int zio_wait(zio_t *zio);
 484 extern void zio_nowait(zio_t *zio);
 485 extern void zio_execute(zio_t *zio);
 486 extern void zio_interrupt(zio_t *zio);
 487
 488 extern zio_t *zio_walk_parents(zio_t *cio);
 489 extern zio_t *zio_walk_children(zio_t *pio);
 490 extern zio_t *zio_unique_parent(zio_t *cio);
 491 extern void zio_add_child(zio_t *pio, zio_t *cio);
 492
 493 extern void *zio_buf_alloc(size_t size);
 494 extern void zio_buf_free(void *buf, size_t size);
 495 extern void *zio_data_buf_alloc(size_t size);
 496 extern void zio_data_buf_free(void *buf, size_t size);
 497 extern void *zio_vdev_alloc(void);
 498 extern void zio_vdev_free(void *buf);
 499
 500 extern void zio_resubmit_stage_async(void *);
 501
 502 extern zio_t *zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd,
 503     uint64_t offset, void *data, uint64_t size, int type, int priority,
 504     enum zio_flag flags, zio_done_func_t *done, void *private);
 505
 506 extern zio_t *zio_vdev_delegated_io(vdev_t *vd, uint64_t offset,
 507     void *data, uint64_t size, int type, int priority,
 508     enum zio_flag flags, zio_done_func_t *done, void *private);
 509
 510 extern void zio_vdev_io_bypass(zio_t *zio);
 511 extern void zio_vdev_io_reissue(zio_t *zio);
 512 extern void zio_vdev_io_redone(zio_t *zio);
 513
 514 extern void zio_checksum_verified(zio_t *zio);
 515 extern int zio_worst_error(int e1, int e2);
 516
 517 extern enum zio_checksum zio_checksum_select(enum zio_checksum child,
 518     enum zio_checksum parent);
 519 extern enum zio_checksum zio_checksum_dedup_select(spa_t *spa,
 520     enum zio_checksum child, enum zio_checksum parent);
 521 extern enum zio_compress zio_compress_select(enum zio_compress child,
 522     enum zio_compress parent);
 523
 524 extern void zio_suspend(spa_t *spa, zio_t *zio);
 525 extern int zio_resume(spa_t *spa);
 526 extern void zio_resume_wait(spa_t *spa);
 527
 528 /*
 529  * Initial setup and teardown.
 530  */
 531 extern void zio_init(void);
 532 extern void zio_fini(void);
 533
 534 /*
 535  * Fault injection
 536  */
 537 struct zinject_record;
 538 extern uint32_t zio_injection_enabled;
 539 extern int zio_inject_fault(char *name, int flags, int *id,
 540     struct zinject_record *record);
 541 extern int zio_inject_list_next(int *id, char *name, size_t buflen,
 542     struct zinject_record *record);
 543 extern int zio_clear_fault(int id);
 544 extern void zio_handle_panic_injection(spa_t *spa, char *tag, uint64_t type);
 545 extern int zio_handle_fault_injection(zio_t *zio, int error);
 546 extern int zio_handle_device_injection(vdev_t *vd, zio_t *zio, int error);
 547 extern int zio_handle_label_injection(zio_t *zio, int error);
 548 extern void zio_handle_ignored_writes(zio_t *zio);
 549
 550 /*
 551  * Checksum ereport functions
 552  */
 553 extern void zfs_ereport_start_checksum(spa_t *spa, vdev_t *vd, struct zio *zio,
 554     uint64_t offset, uint64_t length, void *arg, struct zio_bad_cksum *info);
 555 extern void zfs_ereport_finish_checksum(zio_cksum_report_t *report,
 556     const void *good_data, const void *bad_data, boolean_t drop_if_identical);
 557
 558 extern void zfs_ereport_send_interim_checksum(zio_cksum_report_t *report);
 559 extern void zfs_ereport_free_checksum(zio_cksum_report_t *report);
 560
 561 /* If we have the good data in hand, this function can be used */
 562 extern void zfs_ereport_post_checksum(spa_t *spa, vdev_t *vd,
 563     struct zio *zio, uint64_t offset, uint64_t length,
 564     const void *good_data, const void *bad_data, struct zio_bad_cksum *info);
 565
 566 /* Called from spa_sync(), but primarily an injection handler */
 567 extern void spa_handle_ignored_writes(spa_t *spa);
 568
 569 #ifdef  __cplusplus
 570 }
 571 #endif
 572
 573 #endif  /* _ZIO_H */