usr/src/uts/common/fs/zfs/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  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
  25  * Copyright (c) 2012, 2014 by Delphix. All rights reserved.
  26  * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
  27  * Copyright (c) 2013, Joyent, Inc. All rights reserved.
  28  */
  29
  30 #ifndef _ZIO_H
  31 #define _ZIO_H
  32
  33 #include <sys/zfs_context.h>
  34 #include <sys/spa.h>
  35 #include <sys/txg.h>
  36 #include <sys/avl.h>
  37 #include <sys/fs/zfs.h>
  38 #include <sys/zio_impl.h>
  39
  40 #ifdef  __cplusplus
  41 extern "C" {
  42 #endif
  43
  44 /*
  45  * Embedded checksum
  46  */
  47 #define ZEC_MAGIC       0x210da7ab10c7a11ULL
  48
  49 typedef struct zio_eck {
  50         uint64_t        zec_magic;      /* for validation, endianness   */
  51         zio_cksum_t     zec_cksum;      /* 256-bit checksum             */
  52 } zio_eck_t;
  53
  54 /*
  55  * Gang block headers are self-checksumming and contain an array
  56  * of block pointers.
  57  */
  58 #define SPA_GANGBLOCKSIZE       SPA_MINBLOCKSIZE
  59 #define SPA_GBH_NBLKPTRS        ((SPA_GANGBLOCKSIZE - \
  60         sizeof (zio_eck_t)) / sizeof (blkptr_t))
  61 #define SPA_GBH_FILLER          ((SPA_GANGBLOCKSIZE - \
  62         sizeof (zio_eck_t) - \
  63         (SPA_GBH_NBLKPTRS * sizeof (blkptr_t))) /\
  64         sizeof (uint64_t))
  65
  66 typedef struct zio_gbh {
  67         blkptr_t                zg_blkptr[SPA_GBH_NBLKPTRS];
  68         uint64_t                zg_filler[SPA_GBH_FILLER];
  69         zio_eck_t               zg_tail;
  70 } zio_gbh_phys_t;
  71
  72 enum zio_checksum {
  73         ZIO_CHECKSUM_INHERIT = 0,
  74         ZIO_CHECKSUM_ON,
  75         ZIO_CHECKSUM_OFF,
  76         ZIO_CHECKSUM_LABEL,
  77         ZIO_CHECKSUM_GANG_HEADER,
  78         ZIO_CHECKSUM_ZILOG,
  79         ZIO_CHECKSUM_FLETCHER_2,
  80         ZIO_CHECKSUM_FLETCHER_4,
  81         ZIO_CHECKSUM_SHA256,
  82         ZIO_CHECKSUM_ZILOG2,
  83         ZIO_CHECKSUM_NOPARITY,
  84         ZIO_CHECKSUM_FUNCTIONS
  85 };
  86
  87 /*
  88  * The number of "legacy" compression functions which can be set on individual
  89  * objects.
  90  */
  91 #define ZIO_CHECKSUM_LEGACY_FUNCTIONS ZIO_CHECKSUM_ZILOG2
  92
  93 #define ZIO_CHECKSUM_ON_VALUE   ZIO_CHECKSUM_FLETCHER_4
  94 #define ZIO_CHECKSUM_DEFAULT    ZIO_CHECKSUM_ON
  95
  96 #define ZIO_CHECKSUM_MASK       0xffULL
  97 #define ZIO_CHECKSUM_VERIFY     (1 << 8)
  98
  99 #define ZIO_DEDUPCHECKSUM       ZIO_CHECKSUM_SHA256
 100 #define ZIO_DEDUPDITTO_MIN      100
 101
 102 enum zio_compress {
 103         ZIO_COMPRESS_INHERIT = 0,
 104         ZIO_COMPRESS_ON,
 105         ZIO_COMPRESS_OFF,
 106         ZIO_COMPRESS_LZJB,
 107         ZIO_COMPRESS_EMPTY,
 108         ZIO_COMPRESS_GZIP_1,
 109         ZIO_COMPRESS_GZIP_2,
 110         ZIO_COMPRESS_GZIP_3,
 111         ZIO_COMPRESS_GZIP_4,
 112         ZIO_COMPRESS_GZIP_5,
 113         ZIO_COMPRESS_GZIP_6,
 114         ZIO_COMPRESS_GZIP_7,
 115         ZIO_COMPRESS_GZIP_8,
 116         ZIO_COMPRESS_GZIP_9,
 117         ZIO_COMPRESS_ZLE,
 118         ZIO_COMPRESS_LZ4,
 119         ZIO_COMPRESS_FUNCTIONS
 120 };
 121
 122 /*
 123  * The number of "legacy" compression functions which can be set on individual
 124  * objects.
 125  */
 126 #define ZIO_COMPRESS_LEGACY_FUNCTIONS ZIO_COMPRESS_LZ4
 127
 128 /* N.B. when altering this value, also change BOOTFS_COMPRESS_VALID below */
 129 #define ZIO_COMPRESS_ON_VALUE   ZIO_COMPRESS_LZJB
 130 #define ZIO_COMPRESS_DEFAULT    ZIO_COMPRESS_OFF
 131
 132 #define BOOTFS_COMPRESS_VALID(compress)                 \
 133         ((compress) == ZIO_COMPRESS_LZJB ||             \
 134         (compress) == ZIO_COMPRESS_LZ4 ||               \
 135         ((compress) == ZIO_COMPRESS_ON &&               \
 136         ZIO_COMPRESS_ON_VALUE == ZIO_COMPRESS_LZJB) ||  \
 137         (compress) == ZIO_COMPRESS_OFF)
 138
 139 #define ZIO_FAILURE_MODE_WAIT           0
 140 #define ZIO_FAILURE_MODE_CONTINUE       1
 141 #define ZIO_FAILURE_MODE_PANIC          2
 142
 143 typedef enum zio_priority {
 144         ZIO_PRIORITY_SYNC_READ,
 145         ZIO_PRIORITY_SYNC_WRITE,        /* ZIL */
 146         ZIO_PRIORITY_ASYNC_READ,        /* prefetch */
 147         ZIO_PRIORITY_ASYNC_WRITE,       /* spa_sync() */
 148         ZIO_PRIORITY_SCRUB,             /* asynchronous scrub/resilver reads */
 149         ZIO_PRIORITY_NUM_QUEUEABLE,
 150
 151         ZIO_PRIORITY_NOW                /* non-queued i/os (e.g. free) */
 152 } zio_priority_t;
 153
 154 enum zio_flag {
 155         /*
 156          * Flags inherited by gang, ddt, and vdev children,
 157          * and that must be equal for two zios to aggregate
 158          */
 159         ZIO_FLAG_DONT_AGGREGATE = 1 << 0,
 160         ZIO_FLAG_IO_REPAIR      = 1 << 1,
 161         ZIO_FLAG_SELF_HEAL      = 1 << 2,
 162         ZIO_FLAG_RESILVER       = 1 << 3,
 163         ZIO_FLAG_SCRUB          = 1 << 4,
 164         ZIO_FLAG_SCAN_THREAD    = 1 << 5,
 165         ZIO_FLAG_PHYSICAL       = 1 << 6,
 166
 167 #define ZIO_FLAG_AGG_INHERIT    (ZIO_FLAG_CANFAIL - 1)
 168
 169         /*
 170          * Flags inherited by ddt, gang, and vdev children.
 171          */
 172         ZIO_FLAG_CANFAIL        = 1 << 7,       /* must be first for INHERIT */
 173         ZIO_FLAG_SPECULATIVE    = 1 << 8,
 174         ZIO_FLAG_CONFIG_WRITER  = 1 << 9,
 175         ZIO_FLAG_DONT_RETRY     = 1 << 10,
 176         ZIO_FLAG_DONT_CACHE     = 1 << 11,
 177         ZIO_FLAG_NODATA         = 1 << 12,
 178         ZIO_FLAG_INDUCE_DAMAGE  = 1 << 13,
 179
 180 #define ZIO_FLAG_DDT_INHERIT    (ZIO_FLAG_IO_RETRY - 1)
 181 #define ZIO_FLAG_GANG_INHERIT   (ZIO_FLAG_IO_RETRY - 1)
 182
 183         /*
 184          * Flags inherited by vdev children.
 185          */
 186         ZIO_FLAG_IO_RETRY       = 1 << 14,      /* must be first for INHERIT */
 187         ZIO_FLAG_PROBE          = 1 << 15,
 188         ZIO_FLAG_TRYHARD        = 1 << 16,
 189         ZIO_FLAG_OPTIONAL       = 1 << 17,
 190
 191 #define ZIO_FLAG_VDEV_INHERIT   (ZIO_FLAG_DONT_QUEUE - 1)
 192
 193         /*
 194          * Flags not inherited by any children.
 195          */
 196         ZIO_FLAG_DONT_QUEUE     = 1 << 18,      /* must be first for INHERIT */
 197         ZIO_FLAG_DONT_PROPAGATE = 1 << 19,
 198         ZIO_FLAG_IO_BYPASS      = 1 << 20,
 199         ZIO_FLAG_IO_REWRITE     = 1 << 21,
 200         ZIO_FLAG_RAW            = 1 << 22,
 201         ZIO_FLAG_GANG_CHILD     = 1 << 23,
 202         ZIO_FLAG_DDT_CHILD      = 1 << 24,
 203         ZIO_FLAG_GODFATHER      = 1 << 25,
 204         ZIO_FLAG_NOPWRITE       = 1 << 26,
 205         ZIO_FLAG_REEXECUTED     = 1 << 27,
 206         ZIO_FLAG_DELEGATED      = 1 << 28,
 207 };
 208
 209 #define ZIO_FLAG_MUSTSUCCEED            0
 210
 211 #define ZIO_DDT_CHILD_FLAGS(zio)                                \
 212         (((zio)->io_flags & ZIO_FLAG_DDT_INHERIT) |             \
 213         ZIO_FLAG_DDT_CHILD | ZIO_FLAG_CANFAIL)
 214
 215 #define ZIO_GANG_CHILD_FLAGS(zio)                               \
 216         (((zio)->io_flags & ZIO_FLAG_GANG_INHERIT) |            \
 217         ZIO_FLAG_GANG_CHILD | ZIO_FLAG_CANFAIL)
 218
 219 #define ZIO_VDEV_CHILD_FLAGS(zio)                               \
 220         (((zio)->io_flags & ZIO_FLAG_VDEV_INHERIT) |            \
 221         ZIO_FLAG_CANFAIL)
 222
 223 enum zio_child {
 224         ZIO_CHILD_VDEV = 0,
 225         ZIO_CHILD_GANG,
 226         ZIO_CHILD_DDT,
 227         ZIO_CHILD_LOGICAL,
 228         ZIO_CHILD_TYPES
 229 };
 230
 231 enum zio_wait_type {
 232         ZIO_WAIT_READY = 0,
 233         ZIO_WAIT_DONE,
 234         ZIO_WAIT_TYPES
 235 };
 236
 237 /*
 238  * We'll take the unused errnos, 'EBADE' and 'EBADR' (from the Convergent
 239  * graveyard) to indicate checksum errors and fragmentation.
 240  */
 241 #define ECKSUM  EBADE
 242 #define EFRAGS  EBADR
 243
 244 typedef void zio_done_func_t(zio_t *zio);
 245
 246 extern const char *zio_type_name[ZIO_TYPES];
 247
 248 /*
 249  * A bookmark is a four-tuple <objset, object, level, blkid> that uniquely
 250  * identifies any block in the pool.  By convention, the meta-objset (MOS)
 251  * is objset 0, and the meta-dnode is object 0.  This covers all blocks
 252  * except root blocks and ZIL blocks, which are defined as follows:
 253  *
 254  * Root blocks (objset_phys_t) are object 0, level -1:  <objset, 0, -1, 0>.
 255  * ZIL blocks are bookmarked <objset, 0, -2, blkid == ZIL sequence number>.
 256  * dmu_sync()ed ZIL data blocks are bookmarked <objset, object, -2, blkid>.
 257  *
 258  * Note: this structure is called a bookmark because its original purpose
 259  * was to remember where to resume a pool-wide traverse.
 260  *
 261  * Note: this structure is passed between userland and the kernel, and is
 262  * stored on disk (by virtue of being incorporated into other on-disk
 263  * structures, e.g. dsl_scan_phys_t).
 264  */
 265 typedef struct zbookmark_phys {
 266         uint64_t        zb_objset;
 267         uint64_t        zb_object;
 268         int64_t         zb_level;
 269         uint64_t        zb_blkid;
 270 } zbookmark_phys_t;
 271
 272 #define SET_BOOKMARK(zb, objset, object, level, blkid)  \
 273 {                                                       \
 274         (zb)->zb_objset = objset;                       \
 275         (zb)->zb_object = object;                       \
 276         (zb)->zb_level = level;                         \
 277         (zb)->zb_blkid = blkid;                         \
 278 }
 279
 280 #define ZB_DESTROYED_OBJSET     (-1ULL)
 281
 282 #define ZB_ROOT_OBJECT          (0ULL)
 283 #define ZB_ROOT_LEVEL           (-1LL)
 284 #define ZB_ROOT_BLKID           (0ULL)
 285
 286 #define ZB_ZIL_OBJECT           (0ULL)
 287 #define ZB_ZIL_LEVEL            (-2LL)
 288
 289 #define ZB_IS_ZERO(zb)                                          \
 290         ((zb)->zb_objset == 0 && (zb)->zb_object == 0 &&        \
 291         (zb)->zb_level == 0 && (zb)->zb_blkid == 0)
 292 #define ZB_IS_ROOT(zb)                          \
 293         ((zb)->zb_object == ZB_ROOT_OBJECT &&   \
 294         (zb)->zb_level == ZB_ROOT_LEVEL &&      \
 295         (zb)->zb_blkid == ZB_ROOT_BLKID)
 296
 297 typedef struct zio_prop {
 298         enum zio_checksum       zp_checksum;
 299         enum zio_compress       zp_compress;
 300         dmu_object_type_t       zp_type;
 301         uint8_t                 zp_level;
 302         uint8_t                 zp_copies;
 303         boolean_t               zp_dedup;
 304         boolean_t               zp_dedup_verify;
 305         boolean_t               zp_nopwrite;
 306 } zio_prop_t;
 307
 308 typedef struct zio_cksum_report zio_cksum_report_t;
 309
 310 typedef void zio_cksum_finish_f(zio_cksum_report_t *rep,
 311     const void *good_data);
 312 typedef void zio_cksum_free_f(void *cbdata, size_t size);
 313
 314 struct zio_bad_cksum;                           /* defined in zio_checksum.h */
 315 struct dnode_phys;
 316
 317 struct zio_cksum_report {
 318         struct zio_cksum_report *zcr_next;
 319         nvlist_t                *zcr_ereport;
 320         nvlist_t                *zcr_detector;
 321         void                    *zcr_cbdata;
 322         size_t                  zcr_cbinfo;     /* passed to zcr_free() */
 323         uint64_t                zcr_align;
 324         uint64_t                zcr_length;
 325         zio_cksum_finish_f      *zcr_finish;
 326         zio_cksum_free_f        *zcr_free;
 327
 328         /* internal use only */
 329         struct zio_bad_cksum    *zcr_ckinfo;    /* information from failure */
 330 };
 331
 332 typedef void zio_vsd_cksum_report_f(zio_t *zio, zio_cksum_report_t *zcr,
 333     void *arg);
 334
 335 zio_vsd_cksum_report_f  zio_vsd_default_cksum_report;
 336
 337 typedef struct zio_vsd_ops {
 338         zio_done_func_t         *vsd_free;
 339         zio_vsd_cksum_report_f  *vsd_cksum_report;
 340 } zio_vsd_ops_t;
 341
 342 typedef struct zio_gang_node {
 343         zio_gbh_phys_t          *gn_gbh;
 344         struct zio_gang_node    *gn_child[SPA_GBH_NBLKPTRS];
 345 } zio_gang_node_t;
 346
 347 typedef zio_t *zio_gang_issue_func_t(zio_t *zio, blkptr_t *bp,
 348     zio_gang_node_t *gn, void *data);
 349
 350 typedef void zio_transform_func_t(zio_t *zio, void *data, uint64_t size);
 351
 352 typedef struct zio_transform {
 353         void                    *zt_orig_data;
 354         uint64_t                zt_orig_size;
 355         uint64_t                zt_bufsize;
 356         zio_transform_func_t    *zt_transform;
 357         struct zio_transform    *zt_next;
 358 } zio_transform_t;
 359
 360 typedef int zio_pipe_stage_t(zio_t *zio);
 361
 362 /*
 363  * The io_reexecute flags are distinct from io_flags because the child must
 364  * be able to propagate them to the parent.  The normal io_flags are local
 365  * to the zio, not protected by any lock, and not modifiable by children;
 366  * the reexecute flags are protected by io_lock, modifiable by children,
 367  * and always propagated -- even when ZIO_FLAG_DONT_PROPAGATE is set.
 368  */
 369 #define ZIO_REEXECUTE_NOW       0x01
 370 #define ZIO_REEXECUTE_SUSPEND   0x02
 371
 372 typedef struct zio_link {
 373         zio_t           *zl_parent;
 374         zio_t           *zl_child;
 375         list_node_t     zl_parent_node;
 376         list_node_t     zl_child_node;
 377 } zio_link_t;
 378
 379 struct zio {
 380         /* Core information about this I/O */
 381         zbookmark_phys_t        io_bookmark;
 382         zio_prop_t      io_prop;
 383         zio_type_t      io_type;
 384         enum zio_child  io_child_type;
 385         int             io_cmd;
 386         zio_priority_t  io_priority;
 387         uint8_t         io_reexecute;
 388         uint8_t         io_state[ZIO_WAIT_TYPES];
 389         uint64_t        io_txg;
 390         spa_t           *io_spa;
 391         blkptr_t        *io_bp;
 392         blkptr_t        *io_bp_override;
 393         blkptr_t        io_bp_copy;
 394         list_t          io_parent_list;
 395         list_t          io_child_list;
 396         zio_link_t      *io_walk_link;
 397         zio_t           *io_logical;
 398         zio_transform_t *io_transform_stack;
 399
 400         /* Callback info */
 401         zio_done_func_t *io_ready;
 402         zio_done_func_t *io_physdone;
 403         zio_done_func_t *io_done;
 404         void            *io_private;
 405         int64_t         io_prev_space_delta;    /* DMU private */
 406         blkptr_t        io_bp_orig;
 407
 408         /* Data represented by this I/O */
 409         void            *io_data;
 410         void            *io_orig_data;
 411         uint64_t        io_size;
 412         uint64_t        io_orig_size;
 413
 414         /* Stuff for the vdev stack */
 415         vdev_t          *io_vd;
 416         void            *io_vsd;
 417         const zio_vsd_ops_t *io_vsd_ops;
 418
 419         uint64_t        io_offset;
 420         hrtime_t        io_timestamp;
 421         avl_node_t      io_queue_node;
 422         avl_node_t      io_offset_node;
 423
 424         /* Internal pipeline state */
 425         enum zio_flag   io_flags;
 426         enum zio_stage  io_stage;
 427         enum zio_stage  io_pipeline;
 428         enum zio_flag   io_orig_flags;
 429         enum zio_stage  io_orig_stage;
 430         enum zio_stage  io_orig_pipeline;
 431         int             io_error;
 432         int             io_child_error[ZIO_CHILD_TYPES];
 433         uint64_t        io_children[ZIO_CHILD_TYPES][ZIO_WAIT_TYPES];
 434         uint64_t        io_child_count;
 435         uint64_t        io_phys_children;
 436         uint64_t        io_parent_count;
 437         uint64_t        *io_stall;
 438         zio_t           *io_gang_leader;
 439         zio_gang_node_t *io_gang_tree;
 440         void            *io_executor;
 441         void            *io_waiter;
 442         kmutex_t        io_lock;
 443         kcondvar_t      io_cv;
 444
 445         /* FMA state */
 446         zio_cksum_report_t *io_cksum_report;
 447         uint64_t        io_ena;
 448
 449         /* Taskq dispatching state */
 450         taskq_ent_t     io_tqent;
 451 };
 452
 453 extern zio_t *zio_null(zio_t *pio, spa_t *spa, vdev_t *vd,
 454     zio_done_func_t *done, void *private, enum zio_flag flags);
 455
 456 extern zio_t *zio_root(spa_t *spa,
 457     zio_done_func_t *done, void *private, enum zio_flag flags);
 458
 459 extern zio_t *zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, void *data,
 460     uint64_t size, zio_done_func_t *done, void *private,
 461     zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb);
 462
 463 extern zio_t *zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
 464     void *data, uint64_t size, const zio_prop_t *zp,
 465     zio_done_func_t *ready, zio_done_func_t *physdone, zio_done_func_t *done,
 466     void *private,
 467     zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb);
 468
 469 extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
 470     void *data, uint64_t size, zio_done_func_t *done, void *private,
 471     zio_priority_t priority, enum zio_flag flags, zbookmark_phys_t *zb);
 472
 473 extern void zio_write_override(zio_t *zio, blkptr_t *bp, int copies,
 474     boolean_t nopwrite);
 475
 476 extern void zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp);
 477
 478 extern zio_t *zio_claim(zio_t *pio, spa_t *spa, uint64_t txg,
 479     const blkptr_t *bp,
 480     zio_done_func_t *done, void *private, enum zio_flag flags);
 481
 482 extern zio_t *zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
 483     zio_done_func_t *done, void *private, enum zio_flag flags);
 484
 485 extern zio_t *zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
 486     uint64_t size, void *data, int checksum,
 487     zio_done_func_t *done, void *private, zio_priority_t priority,
 488     enum zio_flag flags, boolean_t labels);
 489
 490 extern zio_t *zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
 491     uint64_t size, void *data, int checksum,
 492     zio_done_func_t *done, void *private, zio_priority_t priority,
 493     enum zio_flag flags, boolean_t labels);
 494
 495 extern zio_t *zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg,
 496     const blkptr_t *bp, enum zio_flag flags);
 497
 498 extern int zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp,
 499     blkptr_t *old_bp, uint64_t size, boolean_t use_slog);
 500 extern void zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp);
 501 extern void zio_flush(zio_t *zio, vdev_t *vd);
 502 extern void zio_shrink(zio_t *zio, uint64_t size);
 503
 504 extern int zio_wait(zio_t *zio);
 505 extern void zio_nowait(zio_t *zio);
 506 extern void zio_execute(zio_t *zio);
 507 extern void zio_interrupt(zio_t *zio);
 508
 509 extern zio_t *zio_walk_parents(zio_t *cio);
 510 extern zio_t *zio_walk_children(zio_t *pio);
 511 extern zio_t *zio_unique_parent(zio_t *cio);
 512 extern void zio_add_child(zio_t *pio, zio_t *cio);
 513
 514 extern void *zio_buf_alloc(size_t size);
 515 extern void zio_buf_free(void *buf, size_t size);
 516 extern void *zio_data_buf_alloc(size_t size);
 517 extern void zio_data_buf_free(void *buf, size_t size);
 518
 519 extern void zio_resubmit_stage_async(void *);
 520
 521 extern zio_t *zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd,
 522     uint64_t offset, void *data, uint64_t size, int type,
 523     zio_priority_t priority, enum zio_flag flags,
 524     zio_done_func_t *done, void *private);
 525
 526 extern zio_t *zio_vdev_delegated_io(vdev_t *vd, uint64_t offset,
 527     void *data, uint64_t size, int type, zio_priority_t priority,
 528     enum zio_flag flags, zio_done_func_t *done, void *private);
 529
 530 extern void zio_vdev_io_bypass(zio_t *zio);
 531 extern void zio_vdev_io_reissue(zio_t *zio);
 532 extern void zio_vdev_io_redone(zio_t *zio);
 533
 534 extern void zio_checksum_verified(zio_t *zio);
 535 extern int zio_worst_error(int e1, int e2);
 536
 537 extern enum zio_checksum zio_checksum_select(enum zio_checksum child,
 538     enum zio_checksum parent);
 539 extern enum zio_checksum zio_checksum_dedup_select(spa_t *spa,
 540     enum zio_checksum child, enum zio_checksum parent);
 541 extern enum zio_compress zio_compress_select(enum zio_compress child,
 542     enum zio_compress parent);
 543
 544 extern void zio_suspend(spa_t *spa, zio_t *zio);
 545 extern int zio_resume(spa_t *spa);
 546 extern void zio_resume_wait(spa_t *spa);
 547
 548 /*
 549  * Initial setup and teardown.
 550  */
 551 extern void zio_init(void);
 552 extern void zio_fini(void);
 553
 554 /*
 555  * Fault injection
 556  */
 557 struct zinject_record;
 558 extern uint32_t zio_injection_enabled;
 559 extern int zio_inject_fault(char *name, int flags, int *id,
 560     struct zinject_record *record);
 561 extern int zio_inject_list_next(int *id, char *name, size_t buflen,
 562     struct zinject_record *record);
 563 extern int zio_clear_fault(int id);
 564 extern void zio_handle_panic_injection(spa_t *spa, char *tag, uint64_t type);
 565 extern int zio_handle_fault_injection(zio_t *zio, int error);
 566 extern int zio_handle_device_injection(vdev_t *vd, zio_t *zio, int error);
 567 extern int zio_handle_label_injection(zio_t *zio, int error);
 568 extern void zio_handle_ignored_writes(zio_t *zio);
 569 extern uint64_t zio_handle_io_delay(zio_t *zio);
 570
 571 /*
 572  * Checksum ereport functions
 573  */
 574 extern void zfs_ereport_start_checksum(spa_t *spa, vdev_t *vd, struct zio *zio,
 575     uint64_t offset, uint64_t length, void *arg, struct zio_bad_cksum *info);
 576 extern void zfs_ereport_finish_checksum(zio_cksum_report_t *report,
 577     const void *good_data, const void *bad_data, boolean_t drop_if_identical);
 578
 579 extern void zfs_ereport_send_interim_checksum(zio_cksum_report_t *report);
 580 extern void zfs_ereport_free_checksum(zio_cksum_report_t *report);
 581
 582 /* If we have the good data in hand, this function can be used */
 583 extern void zfs_ereport_post_checksum(spa_t *spa, vdev_t *vd,
 584     struct zio *zio, uint64_t offset, uint64_t length,
 585     const void *good_data, const void *bad_data, struct zio_bad_cksum *info);
 586
 587 /* Called from spa_sync(), but primarily an injection handler */
 588 extern void spa_handle_ignored_writes(spa_t *spa);
 589
 590 /* zbookmark_phys functions */
 591 boolean_t zbookmark_is_before(const struct dnode_phys *dnp,
 592     const zbookmark_phys_t *zb1, const zbookmark_phys_t *zb2);
 593
 594 #ifdef  __cplusplus
 595 }
 596 #endif
 597
 598 #endif  /* _ZIO_H */