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  * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
  25  * Copyright (c) 2012, 2016 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/zio_priority.h>
  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_SHA512,
  85         ZIO_CHECKSUM_SKEIN,
  86         ZIO_CHECKSUM_EDONR,
  87         ZIO_CHECKSUM_FUNCTIONS
  88 };
  89
  90 /*
  91  * The number of "legacy" compression functions which can be set on individual
  92  * objects.
  93  */
  94 #define ZIO_CHECKSUM_LEGACY_FUNCTIONS ZIO_CHECKSUM_ZILOG2
  95
  96 #define ZIO_CHECKSUM_ON_VALUE   ZIO_CHECKSUM_FLETCHER_4
  97 #define ZIO_CHECKSUM_DEFAULT    ZIO_CHECKSUM_ON
  98
  99 #define ZIO_CHECKSUM_MASK       0xffULL
 100 #define ZIO_CHECKSUM_VERIFY     (1 << 8)
 101
 102 #define ZIO_DEDUPCHECKSUM       ZIO_CHECKSUM_SHA256
 103 #define ZIO_DEDUPDITTO_MIN      100
 104
 105 /*
 106  * The number of "legacy" compression functions which can be set on individual
 107  * objects.
 108  */
 109 #define ZIO_COMPRESS_LEGACY_FUNCTIONS ZIO_COMPRESS_LZ4
 110
 111 /*
 112  * The meaning of "compress = on" selected by the compression features enabled
 113  * on a given pool.
 114  */
 115 #define ZIO_COMPRESS_LEGACY_ON_VALUE    ZIO_COMPRESS_LZJB
 116 #define ZIO_COMPRESS_LZ4_ON_VALUE       ZIO_COMPRESS_LZ4
 117
 118 #define ZIO_COMPRESS_DEFAULT            ZIO_COMPRESS_OFF
 119
 120 #define BOOTFS_COMPRESS_VALID(compress)                 \
 121         ((compress) == ZIO_COMPRESS_LZJB ||             \
 122         (compress) == ZIO_COMPRESS_LZ4 ||               \
 123         (compress) == ZIO_COMPRESS_ON ||                \
 124         (compress) == ZIO_COMPRESS_OFF)
 125
 126 /*
 127  * Default Linux timeout for a sd device.
 128  */
 129 #define ZIO_DELAY_MAX                   (30 * MILLISEC)
 130
 131 #define ZIO_FAILURE_MODE_WAIT           0
 132 #define ZIO_FAILURE_MODE_CONTINUE       1
 133 #define ZIO_FAILURE_MODE_PANIC          2
 134
 135 enum zio_flag {
 136         /*
 137          * Flags inherited by gang, ddt, and vdev children,
 138          * and that must be equal for two zios to aggregate
 139          */
 140         ZIO_FLAG_DONT_AGGREGATE = 1 << 0,
 141         ZIO_FLAG_IO_REPAIR      = 1 << 1,
 142         ZIO_FLAG_SELF_HEAL      = 1 << 2,
 143         ZIO_FLAG_RESILVER       = 1 << 3,
 144         ZIO_FLAG_SCRUB          = 1 << 4,
 145         ZIO_FLAG_SCAN_THREAD    = 1 << 5,
 146         ZIO_FLAG_PHYSICAL       = 1 << 6,
 147
 148 #define ZIO_FLAG_AGG_INHERIT    (ZIO_FLAG_CANFAIL - 1)
 149
 150         /*
 151          * Flags inherited by ddt, gang, and vdev children.
 152          */
 153         ZIO_FLAG_CANFAIL        = 1 << 7,       /* must be first for INHERIT */
 154         ZIO_FLAG_SPECULATIVE    = 1 << 8,
 155         ZIO_FLAG_CONFIG_WRITER  = 1 << 9,
 156         ZIO_FLAG_DONT_RETRY     = 1 << 10,
 157         ZIO_FLAG_DONT_CACHE     = 1 << 11,
 158         ZIO_FLAG_NODATA         = 1 << 12,
 159         ZIO_FLAG_INDUCE_DAMAGE  = 1 << 13,
 160         ZIO_FLAG_IO_ALLOCATING  = 1 << 14,
 161
 162 #define ZIO_FLAG_DDT_INHERIT    (ZIO_FLAG_IO_RETRY - 1)
 163 #define ZIO_FLAG_GANG_INHERIT   (ZIO_FLAG_IO_RETRY - 1)
 164
 165         /*
 166          * Flags inherited by vdev children.
 167          */
 168         ZIO_FLAG_IO_RETRY       = 1 << 15,      /* must be first for INHERIT */
 169         ZIO_FLAG_PROBE          = 1 << 16,
 170         ZIO_FLAG_TRYHARD        = 1 << 17,
 171         ZIO_FLAG_OPTIONAL       = 1 << 18,
 172
 173 #define ZIO_FLAG_VDEV_INHERIT   (ZIO_FLAG_DONT_QUEUE - 1)
 174
 175         /*
 176          * Flags not inherited by any children.
 177          */
 178         ZIO_FLAG_DONT_QUEUE     = 1 << 19,      /* must be first for INHERIT */
 179         ZIO_FLAG_DONT_PROPAGATE = 1 << 20,
 180         ZIO_FLAG_IO_BYPASS      = 1 << 21,
 181         ZIO_FLAG_IO_REWRITE     = 1 << 22,
 182         ZIO_FLAG_RAW            = 1 << 23,
 183         ZIO_FLAG_GANG_CHILD     = 1 << 24,
 184         ZIO_FLAG_DDT_CHILD      = 1 << 25,
 185         ZIO_FLAG_GODFATHER      = 1 << 26,
 186         ZIO_FLAG_NOPWRITE       = 1 << 27,
 187         ZIO_FLAG_REEXECUTED     = 1 << 28,
 188         ZIO_FLAG_DELEGATED      = 1 << 29,
 189         ZIO_FLAG_FASTWRITE      = 1 << 30
 190 };
 191
 192 #define ZIO_FLAG_MUSTSUCCEED            0
 193
 194 #define ZIO_DDT_CHILD_FLAGS(zio)                                \
 195         (((zio)->io_flags & ZIO_FLAG_DDT_INHERIT) |             \
 196         ZIO_FLAG_DDT_CHILD | ZIO_FLAG_CANFAIL)
 197
 198 #define ZIO_GANG_CHILD_FLAGS(zio)                               \
 199         (((zio)->io_flags & ZIO_FLAG_GANG_INHERIT) |            \
 200         ZIO_FLAG_GANG_CHILD | ZIO_FLAG_CANFAIL)
 201
 202 #define ZIO_VDEV_CHILD_FLAGS(zio)                               \
 203         (((zio)->io_flags & ZIO_FLAG_VDEV_INHERIT) |            \
 204         ZIO_FLAG_CANFAIL)
 205
 206 enum zio_child {
 207         ZIO_CHILD_VDEV = 0,
 208         ZIO_CHILD_GANG,
 209         ZIO_CHILD_DDT,
 210         ZIO_CHILD_LOGICAL,
 211         ZIO_CHILD_TYPES
 212 };
 213
 214 enum zio_wait_type {
 215         ZIO_WAIT_READY = 0,
 216         ZIO_WAIT_DONE,
 217         ZIO_WAIT_TYPES
 218 };
 219
 220 /*
 221  * We'll take the unused errnos, 'EBADE' and 'EBADR' (from the Convergent
 222  * graveyard) to indicate checksum errors and fragmentation.
 223  */
 224 #define ECKSUM  EBADE
 225 #define EFRAGS  EBADR
 226
 227 typedef void zio_done_func_t(zio_t *zio);
 228
 229 extern int zio_dva_throttle_enabled;
 230 extern const char *zio_type_name[ZIO_TYPES];
 231
 232 /*
 233  * A bookmark is a four-tuple <objset, object, level, blkid> that uniquely
 234  * identifies any block in the pool.  By convention, the meta-objset (MOS)
 235  * is objset 0, and the meta-dnode is object 0.  This covers all blocks
 236  * except root blocks and ZIL blocks, which are defined as follows:
 237  *
 238  * Root blocks (objset_phys_t) are object 0, level -1:  <objset, 0, -1, 0>.
 239  * ZIL blocks are bookmarked <objset, 0, -2, blkid == ZIL sequence number>.
 240  * dmu_sync()ed ZIL data blocks are bookmarked <objset, object, -2, blkid>.
 241  * dnode visit bookmarks are <objset, object id of dnode, -3, 0>.
 242  *
 243  * Note: this structure is called a bookmark because its original purpose
 244  * was to remember where to resume a pool-wide traverse.
 245  *
 246  * Note: this structure is passed between userland and the kernel, and is
 247  * stored on disk (by virtue of being incorporated into other on-disk
 248  * structures, e.g. dsl_scan_phys_t).
 249  */
 250 struct zbookmark_phys {
 251         uint64_t        zb_objset;
 252         uint64_t        zb_object;
 253         int64_t         zb_level;
 254         uint64_t        zb_blkid;
 255 };
 256
 257 #define SET_BOOKMARK(zb, objset, object, level, blkid)  \
 258 {                                                       \
 259         (zb)->zb_objset = objset;                       \
 260         (zb)->zb_object = object;                       \
 261         (zb)->zb_level = level;                         \
 262         (zb)->zb_blkid = blkid;                         \
 263 }
 264
 265 #define ZB_DESTROYED_OBJSET     (-1ULL)
 266
 267 #define ZB_ROOT_OBJECT          (0ULL)
 268 #define ZB_ROOT_LEVEL           (-1LL)
 269 #define ZB_ROOT_BLKID           (0ULL)
 270
 271 #define ZB_ZIL_OBJECT           (0ULL)
 272 #define ZB_ZIL_LEVEL            (-2LL)
 273
 274 #define ZB_DNODE_LEVEL          (-3LL)
 275 #define ZB_DNODE_BLKID          (0ULL)
 276
 277 #define ZB_IS_ZERO(zb)                                          \
 278         ((zb)->zb_objset == 0 && (zb)->zb_object == 0 &&        \
 279         (zb)->zb_level == 0 && (zb)->zb_blkid == 0)
 280 #define ZB_IS_ROOT(zb)                          \
 281         ((zb)->zb_object == ZB_ROOT_OBJECT &&   \
 282         (zb)->zb_level == ZB_ROOT_LEVEL &&      \
 283         (zb)->zb_blkid == ZB_ROOT_BLKID)
 284
 285 typedef struct zio_prop {
 286         enum zio_checksum       zp_checksum;
 287         enum zio_compress       zp_compress;
 288         dmu_object_type_t       zp_type;
 289         uint8_t                 zp_level;
 290         uint8_t                 zp_copies;
 291         boolean_t               zp_dedup;
 292         boolean_t               zp_dedup_verify;
 293         boolean_t               zp_nopwrite;
 294 } zio_prop_t;
 295
 296 typedef struct zio_cksum_report zio_cksum_report_t;
 297
 298 typedef void zio_cksum_finish_f(zio_cksum_report_t *rep,
 299     const void *good_data);
 300 typedef void zio_cksum_free_f(void *cbdata, size_t size);
 301
 302 struct zio_bad_cksum;                           /* defined in zio_checksum.h */
 303 struct dnode_phys;
 304
 305 struct zio_cksum_report {
 306         struct zio_cksum_report *zcr_next;
 307         nvlist_t                *zcr_ereport;
 308         nvlist_t                *zcr_detector;
 309         void                    *zcr_cbdata;
 310         size_t                  zcr_cbinfo;     /* passed to zcr_free() */
 311         uint64_t                zcr_align;
 312         uint64_t                zcr_length;
 313         zio_cksum_finish_f      *zcr_finish;
 314         zio_cksum_free_f        *zcr_free;
 315
 316         /* internal use only */
 317         struct zio_bad_cksum    *zcr_ckinfo;    /* information from failure */
 318 };
 319
 320 typedef void zio_vsd_cksum_report_f(zio_t *zio, zio_cksum_report_t *zcr,
 321     void *arg);
 322
 323 zio_vsd_cksum_report_f  zio_vsd_default_cksum_report;
 324
 325 typedef struct zio_vsd_ops {
 326         zio_done_func_t         *vsd_free;
 327         zio_vsd_cksum_report_f  *vsd_cksum_report;
 328 } zio_vsd_ops_t;
 329
 330 typedef struct zio_gang_node {
 331         zio_gbh_phys_t          *gn_gbh;
 332         struct zio_gang_node    *gn_child[SPA_GBH_NBLKPTRS];
 333 } zio_gang_node_t;
 334
 335 typedef zio_t *zio_gang_issue_func_t(zio_t *zio, blkptr_t *bp,
 336     zio_gang_node_t *gn, void *data);
 337
 338 typedef void zio_transform_func_t(zio_t *zio, void *data, uint64_t size);
 339
 340 typedef struct zio_transform {
 341         void                    *zt_orig_data;
 342         uint64_t                zt_orig_size;
 343         uint64_t                zt_bufsize;
 344         zio_transform_func_t    *zt_transform;
 345         struct zio_transform    *zt_next;
 346 } zio_transform_t;
 347
 348 typedef int zio_pipe_stage_t(zio_t *zio);
 349
 350 /*
 351  * The io_reexecute flags are distinct from io_flags because the child must
 352  * be able to propagate them to the parent.  The normal io_flags are local
 353  * to the zio, not protected by any lock, and not modifiable by children;
 354  * the reexecute flags are protected by io_lock, modifiable by children,
 355  * and always propagated -- even when ZIO_FLAG_DONT_PROPAGATE is set.
 356  */
 357 #define ZIO_REEXECUTE_NOW       0x01
 358 #define ZIO_REEXECUTE_SUSPEND   0x02
 359
 360 typedef struct zio_link {
 361         zio_t           *zl_parent;
 362         zio_t           *zl_child;
 363         list_node_t     zl_parent_node;
 364         list_node_t     zl_child_node;
 365 } zio_link_t;
 366
 367 struct zio {
 368         /* Core information about this I/O */
 369         zbookmark_phys_t        io_bookmark;
 370         zio_prop_t      io_prop;
 371         zio_type_t      io_type;
 372         enum zio_child  io_child_type;
 373         int             io_cmd;
 374         zio_priority_t  io_priority;
 375         uint8_t         io_reexecute;
 376         uint8_t         io_state[ZIO_WAIT_TYPES];
 377         uint64_t        io_txg;
 378         spa_t           *io_spa;
 379         blkptr_t        *io_bp;
 380         blkptr_t        *io_bp_override;
 381         blkptr_t        io_bp_copy;
 382         list_t          io_parent_list;
 383         list_t          io_child_list;
 384         zio_t           *io_logical;
 385         zio_transform_t *io_transform_stack;
 386
 387         /* Callback info */
 388         zio_done_func_t *io_ready;
 389         zio_done_func_t *io_children_ready;
 390         zio_done_func_t *io_physdone;
 391         zio_done_func_t *io_done;
 392         void            *io_private;
 393         int64_t         io_prev_space_delta;    /* DMU private */
 394         blkptr_t        io_bp_orig;
 395         /* io_lsize != io_orig_size iff this is a raw write */
 396         uint64_t        io_lsize;
 397
 398         /* Data represented by this I/O */
 399         void            *io_data;
 400         void            *io_orig_data;
 401         uint64_t        io_size;
 402         uint64_t        io_orig_size;
 403
 404         /* Stuff for the vdev stack */
 405         vdev_t          *io_vd;
 406         void            *io_vsd;
 407         const zio_vsd_ops_t *io_vsd_ops;
 408
 409         uint64_t        io_offset;
 410         hrtime_t        io_timestamp;   /* submitted at */
 411         hrtime_t        io_queued_timestamp;
 412         hrtime_t        io_target_timestamp;
 413         hrtime_t        io_delta;       /* vdev queue service delta */
 414         hrtime_t        io_delay;       /* Device access time (disk or */
 415                                         /* file). */
 416         avl_node_t      io_queue_node;
 417         avl_node_t      io_offset_node;
 418         avl_node_t      io_alloc_node;
 419
 420         /* Internal pipeline state */
 421         enum zio_flag   io_flags;
 422         enum zio_stage  io_stage;
 423         enum zio_stage  io_pipeline;
 424         enum zio_flag   io_orig_flags;
 425         enum zio_stage  io_orig_stage;
 426         enum zio_stage  io_orig_pipeline;
 427         enum zio_stage  io_pipeline_trace;
 428         int             io_error;
 429         int             io_child_error[ZIO_CHILD_TYPES];
 430         uint64_t        io_children[ZIO_CHILD_TYPES][ZIO_WAIT_TYPES];
 431         uint64_t        io_child_count;
 432         uint64_t        io_phys_children;
 433         uint64_t        io_parent_count;
 434         uint64_t        *io_stall;
 435         zio_t           *io_gang_leader;
 436         zio_gang_node_t *io_gang_tree;
 437         void            *io_executor;
 438         void            *io_waiter;
 439         kmutex_t        io_lock;
 440         kcondvar_t      io_cv;
 441
 442         /* FMA state */
 443         zio_cksum_report_t *io_cksum_report;
 444         uint64_t        io_ena;
 445
 446         /* Taskq dispatching state */
 447         taskq_ent_t     io_tqent;
 448 };
 449
 450 extern int zio_timestamp_compare(const void *, const void *);
 451
 452 extern zio_t *zio_null(zio_t *pio, spa_t *spa, vdev_t *vd,
 453     zio_done_func_t *done, void *private, enum zio_flag flags);
 454
 455 extern zio_t *zio_root(spa_t *spa,
 456     zio_done_func_t *done, void *private, enum zio_flag flags);
 457
 458 extern zio_t *zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, void *data,
 459     uint64_t lsize, zio_done_func_t *done, void *private,
 460     zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb);
 461
 462 extern zio_t *zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
 463     void *data, uint64_t size, uint64_t psize, const zio_prop_t *zp,
 464     zio_done_func_t *ready, zio_done_func_t *children_ready,
 465     zio_done_func_t *physdone, zio_done_func_t *done,
 466     void *private, zio_priority_t priority, enum zio_flag flags,
 467     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     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 extern void zio_delay_init(zio_t *zio);
 509 extern void zio_delay_interrupt(zio_t *zio);
 510
 511 extern zio_t *zio_walk_parents(zio_t *cio, zio_link_t **);
 512 extern zio_t *zio_walk_children(zio_t *pio, zio_link_t **);
 513 extern zio_t *zio_unique_parent(zio_t *cio);
 514 extern void zio_add_child(zio_t *pio, zio_t *cio);
 515
 516 extern void *zio_buf_alloc(size_t size);
 517 extern void zio_buf_free(void *buf, size_t size);
 518 extern void *zio_data_buf_alloc(size_t size);
 519 extern void zio_data_buf_free(void *buf, size_t size);
 520 extern void *zio_buf_alloc_flags(size_t size, int flags);
 521
 522 extern void zio_push_transform(zio_t *zio, void *data, uint64_t size,
 523     uint64_t bufsize, zio_transform_func_t *transform);
 524 extern void zio_pop_transforms(zio_t *zio);
 525
 526 extern void zio_resubmit_stage_async(void *);
 527
 528 extern zio_t *zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd,
 529     uint64_t offset, void *data, uint64_t size, int type,
 530     zio_priority_t priority, enum zio_flag flags,
 531     zio_done_func_t *done, void *private);
 532
 533 extern zio_t *zio_vdev_delegated_io(vdev_t *vd, uint64_t offset,
 534     void *data, uint64_t size, int type, zio_priority_t priority,
 535     enum zio_flag flags, zio_done_func_t *done, void *private);
 536
 537 extern void zio_vdev_io_bypass(zio_t *zio);
 538 extern void zio_vdev_io_reissue(zio_t *zio);
 539 extern void zio_vdev_io_redone(zio_t *zio);
 540
 541 extern void zio_checksum_verified(zio_t *zio);
 542 extern int zio_worst_error(int e1, int e2);
 543
 544 extern enum zio_checksum zio_checksum_select(enum zio_checksum child,
 545     enum zio_checksum parent);
 546 extern enum zio_checksum zio_checksum_dedup_select(spa_t *spa,
 547     enum zio_checksum child, enum zio_checksum parent);
 548 extern enum zio_compress zio_compress_select(spa_t *spa,
 549     enum zio_compress child, enum zio_compress parent);
 550
 551 extern void zio_suspend(spa_t *spa, zio_t *zio);
 552 extern int zio_resume(spa_t *spa);
 553 extern void zio_resume_wait(spa_t *spa);
 554
 555 /*
 556  * Initial setup and teardown.
 557  */
 558 extern void zio_init(void);
 559 extern void zio_fini(void);
 560
 561 /*
 562  * Fault injection
 563  */
 564 struct zinject_record;
 565 extern uint32_t zio_injection_enabled;
 566 extern int zio_inject_fault(char *name, int flags, int *id,
 567     struct zinject_record *record);
 568 extern int zio_inject_list_next(int *id, char *name, size_t buflen,
 569     struct zinject_record *record);
 570 extern int zio_clear_fault(int id);
 571 extern void zio_handle_panic_injection(spa_t *spa, char *tag, uint64_t type);
 572 extern int zio_handle_fault_injection(zio_t *zio, int error);
 573 extern int zio_handle_device_injection(vdev_t *vd, zio_t *zio, int error);
 574 extern int zio_handle_label_injection(zio_t *zio, int error);
 575 extern void zio_handle_ignored_writes(zio_t *zio);
 576 extern hrtime_t zio_handle_io_delay(zio_t *zio);
 577
 578 /*
 579  * Checksum ereport functions
 580  */
 581 extern void zfs_ereport_start_checksum(spa_t *spa, vdev_t *vd, struct zio *zio,
 582     uint64_t offset, uint64_t length, void *arg, struct zio_bad_cksum *info);
 583 extern void zfs_ereport_finish_checksum(zio_cksum_report_t *report,
 584     const void *good_data, const void *bad_data, boolean_t drop_if_identical);
 585
 586 extern void zfs_ereport_free_checksum(zio_cksum_report_t *report);
 587
 588 /* If we have the good data in hand, this function can be used */
 589 extern void zfs_ereport_post_checksum(spa_t *spa, vdev_t *vd,
 590     struct zio *zio, uint64_t offset, uint64_t length,
 591     const void *good_data, const void *bad_data, struct zio_bad_cksum *info);
 592
 593 /* Called from spa_sync(), but primarily an injection handler */
 594 extern void spa_handle_ignored_writes(spa_t *spa);
 595
 596 /* zbookmark_phys functions */
 597 boolean_t zbookmark_subtree_completed(const struct dnode_phys *dnp,
 598     const zbookmark_phys_t *subtree_root, const zbookmark_phys_t *last_block);
 599 int zbookmark_compare(uint16_t dbss1, uint8_t ibs1, uint16_t dbss2,
 600     uint8_t ibs2, const zbookmark_phys_t *zb1, const zbookmark_phys_t *zb2);
 601
 602 #ifdef  __cplusplus
 603 }
 604 #endif
 605
 606 #endif  /* _ZIO_H */