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, 2014 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_FUNCTIONS
  84 };
  85
  86 /*
  87  * The number of "legacy" compression functions which can be set on individual
  88  * objects.
  89  */
  90 #define ZIO_CHECKSUM_LEGACY_FUNCTIONS ZIO_CHECKSUM_ZILOG2
  91
  92 #define ZIO_CHECKSUM_ON_VALUE   ZIO_CHECKSUM_FLETCHER_4
  93 #define ZIO_CHECKSUM_DEFAULT    ZIO_CHECKSUM_ON
  94
  95 #define ZIO_CHECKSUM_MASK       0xffULL
  96 #define ZIO_CHECKSUM_VERIFY     (1 << 8)
  97
  98 #define ZIO_DEDUPCHECKSUM       ZIO_CHECKSUM_SHA256
  99 #define ZIO_DEDUPDITTO_MIN      100
 100
 101 enum zio_compress {
 102         ZIO_COMPRESS_INHERIT = 0,
 103         ZIO_COMPRESS_ON,
 104         ZIO_COMPRESS_OFF,
 105         ZIO_COMPRESS_LZJB,
 106         ZIO_COMPRESS_EMPTY,
 107         ZIO_COMPRESS_GZIP_1,
 108         ZIO_COMPRESS_GZIP_2,
 109         ZIO_COMPRESS_GZIP_3,
 110         ZIO_COMPRESS_GZIP_4,
 111         ZIO_COMPRESS_GZIP_5,
 112         ZIO_COMPRESS_GZIP_6,
 113         ZIO_COMPRESS_GZIP_7,
 114         ZIO_COMPRESS_GZIP_8,
 115         ZIO_COMPRESS_GZIP_9,
 116         ZIO_COMPRESS_ZLE,
 117         ZIO_COMPRESS_LZ4,
 118         ZIO_COMPRESS_FUNCTIONS
 119 };
 120
 121 /*
 122  * The number of "legacy" compression functions which can be set on individual
 123  * objects.
 124  */
 125 #define ZIO_COMPRESS_LEGACY_FUNCTIONS ZIO_COMPRESS_LZ4
 126
 127 /*
 128  * The meaning of "compress = on" selected by the compression features enabled
 129  * on a given pool.
 130  */
 131 #define ZIO_COMPRESS_LEGACY_ON_VALUE    ZIO_COMPRESS_LZJB
 132 #define ZIO_COMPRESS_LZ4_ON_VALUE       ZIO_COMPRESS_LZ4
 133
 134 #define ZIO_COMPRESS_DEFAULT            ZIO_COMPRESS_OFF
 135
 136 #define BOOTFS_COMPRESS_VALID(compress)                 \
 137         ((compress) == ZIO_COMPRESS_LZJB ||             \
 138         (compress) == ZIO_COMPRESS_LZ4 ||               \
 139         (compress) == ZIO_COMPRESS_ON ||                \
 140         (compress) == ZIO_COMPRESS_OFF)
 141
 142 /*
 143  * Default Linux timeout for a sd device.
 144  */
 145 #define ZIO_DELAY_MAX                   (30 * MILLISEC)
 146
 147 #define ZIO_FAILURE_MODE_WAIT           0
 148 #define ZIO_FAILURE_MODE_CONTINUE       1
 149 #define ZIO_FAILURE_MODE_PANIC          2
 150
 151 enum zio_flag {
 152         /*
 153          * Flags inherited by gang, ddt, and vdev children,
 154          * and that must be equal for two zios to aggregate
 155          */
 156         ZIO_FLAG_DONT_AGGREGATE = 1 << 0,
 157         ZIO_FLAG_IO_REPAIR      = 1 << 1,
 158         ZIO_FLAG_SELF_HEAL      = 1 << 2,
 159         ZIO_FLAG_RESILVER       = 1 << 3,
 160         ZIO_FLAG_SCRUB          = 1 << 4,
 161         ZIO_FLAG_SCAN_THREAD    = 1 << 5,
 162         ZIO_FLAG_PHYSICAL       = 1 << 6,
 163
 164 #define ZIO_FLAG_AGG_INHERIT    (ZIO_FLAG_CANFAIL - 1)
 165
 166         /*
 167          * Flags inherited by ddt, gang, and vdev children.
 168          */
 169         ZIO_FLAG_CANFAIL        = 1 << 7,       /* must be first for INHERIT */
 170         ZIO_FLAG_SPECULATIVE    = 1 << 8,
 171         ZIO_FLAG_CONFIG_WRITER  = 1 << 9,
 172         ZIO_FLAG_DONT_RETRY     = 1 << 10,
 173         ZIO_FLAG_DONT_CACHE     = 1 << 11,
 174         ZIO_FLAG_NODATA         = 1 << 12,
 175         ZIO_FLAG_INDUCE_DAMAGE  = 1 << 13,
 176
 177 #define ZIO_FLAG_DDT_INHERIT    (ZIO_FLAG_IO_RETRY - 1)
 178 #define ZIO_FLAG_GANG_INHERIT   (ZIO_FLAG_IO_RETRY - 1)
 179
 180         /*
 181          * Flags inherited by vdev children.
 182          */
 183         ZIO_FLAG_IO_RETRY       = 1 << 14,      /* must be first for INHERIT */
 184         ZIO_FLAG_PROBE          = 1 << 15,
 185         ZIO_FLAG_TRYHARD        = 1 << 16,
 186         ZIO_FLAG_OPTIONAL       = 1 << 17,
 187
 188 #define ZIO_FLAG_VDEV_INHERIT   (ZIO_FLAG_DONT_QUEUE - 1)
 189
 190         /*
 191          * Flags not inherited by any children.
 192          */
 193         ZIO_FLAG_DONT_QUEUE     = 1 << 18,      /* must be first for INHERIT */
 194         ZIO_FLAG_DONT_PROPAGATE = 1 << 19,
 195         ZIO_FLAG_IO_BYPASS      = 1 << 20,
 196         ZIO_FLAG_IO_REWRITE     = 1 << 21,
 197         ZIO_FLAG_RAW            = 1 << 22,
 198         ZIO_FLAG_GANG_CHILD     = 1 << 23,
 199         ZIO_FLAG_DDT_CHILD      = 1 << 24,
 200         ZIO_FLAG_GODFATHER      = 1 << 25,
 201         ZIO_FLAG_NOPWRITE       = 1 << 26,
 202         ZIO_FLAG_REEXECUTED     = 1 << 27,
 203         ZIO_FLAG_DELEGATED      = 1 << 28,
 204         ZIO_FLAG_FASTWRITE      = 1 << 29,
 205 };
 206
 207 #define ZIO_FLAG_MUSTSUCCEED            0
 208
 209 #define ZIO_DDT_CHILD_FLAGS(zio)                                \
 210         (((zio)->io_flags & ZIO_FLAG_DDT_INHERIT) |             \
 211         ZIO_FLAG_DDT_CHILD | ZIO_FLAG_CANFAIL)
 212
 213 #define ZIO_GANG_CHILD_FLAGS(zio)                               \
 214         (((zio)->io_flags & ZIO_FLAG_GANG_INHERIT) |            \
 215         ZIO_FLAG_GANG_CHILD | ZIO_FLAG_CANFAIL)
 216
 217 #define ZIO_VDEV_CHILD_FLAGS(zio)                               \
 218         (((zio)->io_flags & ZIO_FLAG_VDEV_INHERIT) |            \
 219         ZIO_FLAG_CANFAIL)
 220
 221 enum zio_child {
 222         ZIO_CHILD_VDEV = 0,
 223         ZIO_CHILD_GANG,
 224         ZIO_CHILD_DDT,
 225         ZIO_CHILD_LOGICAL,
 226         ZIO_CHILD_TYPES
 227 };
 228
 229 enum zio_wait_type {
 230         ZIO_WAIT_READY = 0,
 231         ZIO_WAIT_DONE,
 232         ZIO_WAIT_TYPES
 233 };
 234
 235 /*
 236  * We'll take the unused errnos, 'EBADE' and 'EBADR' (from the Convergent
 237  * graveyard) to indicate checksum errors and fragmentation.
 238  */
 239 #define ECKSUM  EBADE
 240 #define EFRAGS  EBADR
 241
 242 typedef void zio_done_func_t(zio_t *zio);
 243
 244 extern const char *zio_type_name[ZIO_TYPES];
 245
 246 /*
 247  * A bookmark is a four-tuple <objset, object, level, blkid> that uniquely
 248  * identifies any block in the pool.  By convention, the meta-objset (MOS)
 249  * is objset 0, and the meta-dnode is object 0.  This covers all blocks
 250  * except root blocks and ZIL blocks, which are defined as follows:
 251  *
 252  * Root blocks (objset_phys_t) are object 0, level -1:  <objset, 0, -1, 0>.
 253  * ZIL blocks are bookmarked <objset, 0, -2, blkid == ZIL sequence number>.
 254  * dmu_sync()ed ZIL data blocks are bookmarked <objset, object, -2, blkid>.
 255  * dnode visit bookmarks are <objset, object id of dnode, -3, 0>.
 256  *
 257  * Note: this structure is called a bookmark because its original purpose
 258  * was to remember where to resume a pool-wide traverse.
 259  *
 260  * Note: this structure is passed between userland and the kernel, and is
 261  * stored on disk (by virtue of being incorporated into other on-disk
 262  * structures, e.g. dsl_scan_phys_t).
 263  */
 264 struct zbookmark_phys {
 265         uint64_t        zb_objset;
 266         uint64_t        zb_object;
 267         int64_t         zb_level;
 268         uint64_t        zb_blkid;
 269 };
 270
 271 #define SET_BOOKMARK(zb, objset, object, level, blkid)  \
 272 {                                                       \
 273         (zb)->zb_objset = objset;                       \
 274         (zb)->zb_object = object;                       \
 275         (zb)->zb_level = level;                         \
 276         (zb)->zb_blkid = blkid;                         \
 277 }
 278
 279 #define ZB_DESTROYED_OBJSET     (-1ULL)
 280
 281 #define ZB_ROOT_OBJECT          (0ULL)
 282 #define ZB_ROOT_LEVEL           (-1LL)
 283 #define ZB_ROOT_BLKID           (0ULL)
 284
 285 #define ZB_ZIL_OBJECT           (0ULL)
 286 #define ZB_ZIL_LEVEL            (-2LL)
 287
 288 #define ZB_DNODE_LEVEL          (-3LL)
 289 #define ZB_DNODE_BLKID          (0ULL)
 290
 291 #define ZB_IS_ZERO(zb)                                          \
 292         ((zb)->zb_objset == 0 && (zb)->zb_object == 0 &&        \
 293         (zb)->zb_level == 0 && (zb)->zb_blkid == 0)
 294 #define ZB_IS_ROOT(zb)                          \
 295         ((zb)->zb_object == ZB_ROOT_OBJECT &&   \
 296         (zb)->zb_level == ZB_ROOT_LEVEL &&      \
 297         (zb)->zb_blkid == ZB_ROOT_BLKID)
 298
 299 typedef struct zio_prop {
 300         enum zio_checksum       zp_checksum;
 301         enum zio_compress       zp_compress;
 302         dmu_object_type_t       zp_type;
 303         uint8_t                 zp_level;
 304         uint8_t                 zp_copies;
 305         boolean_t               zp_dedup;
 306         boolean_t               zp_dedup_verify;
 307         boolean_t               zp_nopwrite;
 308 } zio_prop_t;
 309
 310 typedef struct zio_cksum_report zio_cksum_report_t;
 311
 312 typedef void zio_cksum_finish_f(zio_cksum_report_t *rep,
 313     const void *good_data);
 314 typedef void zio_cksum_free_f(void *cbdata, size_t size);
 315
 316 struct zio_bad_cksum;                           /* defined in zio_checksum.h */
 317 struct dnode_phys;
 318
 319 struct zio_cksum_report {
 320         struct zio_cksum_report *zcr_next;
 321         nvlist_t                *zcr_ereport;
 322         nvlist_t                *zcr_detector;
 323         void                    *zcr_cbdata;
 324         size_t                  zcr_cbinfo;     /* passed to zcr_free() */
 325         uint64_t                zcr_align;
 326         uint64_t                zcr_length;
 327         zio_cksum_finish_f      *zcr_finish;
 328         zio_cksum_free_f        *zcr_free;
 329
 330         /* internal use only */
 331         struct zio_bad_cksum    *zcr_ckinfo;    /* information from failure */
 332 };
 333
 334 typedef void zio_vsd_cksum_report_f(zio_t *zio, zio_cksum_report_t *zcr,
 335     void *arg);
 336
 337 zio_vsd_cksum_report_f  zio_vsd_default_cksum_report;
 338
 339 typedef struct zio_vsd_ops {
 340         zio_done_func_t         *vsd_free;
 341         zio_vsd_cksum_report_f  *vsd_cksum_report;
 342 } zio_vsd_ops_t;
 343
 344 typedef struct zio_gang_node {
 345         zio_gbh_phys_t          *gn_gbh;
 346         struct zio_gang_node    *gn_child[SPA_GBH_NBLKPTRS];
 347 } zio_gang_node_t;
 348
 349 typedef zio_t *zio_gang_issue_func_t(zio_t *zio, blkptr_t *bp,
 350     zio_gang_node_t *gn, void *data);
 351
 352 typedef void zio_transform_func_t(zio_t *zio, void *data, uint64_t size);
 353
 354 typedef struct zio_transform {
 355         void                    *zt_orig_data;
 356         uint64_t                zt_orig_size;
 357         uint64_t                zt_bufsize;
 358         zio_transform_func_t    *zt_transform;
 359         struct zio_transform    *zt_next;
 360 } zio_transform_t;
 361
 362 typedef int zio_pipe_stage_t(zio_t *zio);
 363
 364 /*
 365  * The io_reexecute flags are distinct from io_flags because the child must
 366  * be able to propagate them to the parent.  The normal io_flags are local
 367  * to the zio, not protected by any lock, and not modifiable by children;
 368  * the reexecute flags are protected by io_lock, modifiable by children,
 369  * and always propagated -- even when ZIO_FLAG_DONT_PROPAGATE is set.
 370  */
 371 #define ZIO_REEXECUTE_NOW       0x01
 372 #define ZIO_REEXECUTE_SUSPEND   0x02
 373
 374 typedef struct zio_link {
 375         zio_t           *zl_parent;
 376         zio_t           *zl_child;
 377         list_node_t     zl_parent_node;
 378         list_node_t     zl_child_node;
 379 } zio_link_t;
 380
 381 struct zio {
 382         /* Core information about this I/O */
 383         zbookmark_phys_t        io_bookmark;
 384         zio_prop_t      io_prop;
 385         zio_type_t      io_type;
 386         enum zio_child  io_child_type;
 387         int             io_cmd;
 388         zio_priority_t  io_priority;
 389         uint8_t         io_reexecute;
 390         uint8_t         io_state[ZIO_WAIT_TYPES];
 391         uint64_t        io_txg;
 392         spa_t           *io_spa;
 393         blkptr_t        *io_bp;
 394         blkptr_t        *io_bp_override;
 395         blkptr_t        io_bp_copy;
 396         list_t          io_parent_list;
 397         list_t          io_child_list;
 398         zio_link_t      *io_walk_link;
 399         zio_t           *io_logical;
 400         zio_transform_t *io_transform_stack;
 401
 402         /* Callback info */
 403         zio_done_func_t *io_ready;
 404         zio_done_func_t *io_physdone;
 405         zio_done_func_t *io_done;
 406         void            *io_private;
 407         int64_t         io_prev_space_delta;    /* DMU private */
 408         blkptr_t        io_bp_orig;
 409
 410         /* Data represented by this I/O */
 411         void            *io_data;
 412         void            *io_orig_data;
 413         uint64_t        io_size;
 414         uint64_t        io_orig_size;
 415
 416         /* Stuff for the vdev stack */
 417         vdev_t          *io_vd;
 418         void            *io_vsd;
 419         const zio_vsd_ops_t *io_vsd_ops;
 420
 421         uint64_t        io_offset;
 422         hrtime_t        io_timestamp;   /* submitted at */
 423         hrtime_t        io_delta;       /* vdev queue service delta */
 424         uint64_t        io_delay;       /* vdev disk service delta (ticks) */
 425         avl_node_t      io_queue_node;
 426         avl_node_t      io_offset_node;
 427
 428         /* Internal pipeline state */
 429         enum zio_flag   io_flags;
 430         enum zio_stage  io_stage;
 431         enum zio_stage  io_pipeline;
 432         enum zio_flag   io_orig_flags;
 433         enum zio_stage  io_orig_stage;
 434         enum zio_stage  io_orig_pipeline;
 435         int             io_error;
 436         int             io_child_error[ZIO_CHILD_TYPES];
 437         uint64_t        io_children[ZIO_CHILD_TYPES][ZIO_WAIT_TYPES];
 438         uint64_t        io_child_count;
 439         uint64_t        io_phys_children;
 440         uint64_t        io_parent_count;
 441         uint64_t        *io_stall;
 442         zio_t           *io_gang_leader;
 443         zio_gang_node_t *io_gang_tree;
 444         void            *io_executor;
 445         void            *io_waiter;
 446         kmutex_t        io_lock;
 447         kcondvar_t      io_cv;
 448
 449         /* FMA state */
 450         zio_cksum_report_t *io_cksum_report;
 451         uint64_t        io_ena;
 452
 453         /* Taskq dispatching state */
 454         taskq_ent_t     io_tqent;
 455 };
 456
 457 extern zio_t *zio_null(zio_t *pio, spa_t *spa, vdev_t *vd,
 458     zio_done_func_t *done, void *private, enum zio_flag flags);
 459
 460 extern zio_t *zio_root(spa_t *spa,
 461     zio_done_func_t *done, void *private, enum zio_flag flags);
 462
 463 extern zio_t *zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, void *data,
 464     uint64_t size, zio_done_func_t *done, void *private,
 465     zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb);
 466
 467 extern zio_t *zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
 468     void *data, uint64_t size, const zio_prop_t *zp,
 469     zio_done_func_t *ready, zio_done_func_t *physdone, zio_done_func_t *done,
 470     void *private,
 471     zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb);
 472
 473 extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
 474     void *data, uint64_t size, zio_done_func_t *done, void *private,
 475     zio_priority_t priority, enum zio_flag flags, zbookmark_phys_t *zb);
 476
 477 extern void zio_write_override(zio_t *zio, blkptr_t *bp, int copies,
 478     boolean_t nopwrite);
 479
 480 extern void zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp);
 481
 482 extern zio_t *zio_claim(zio_t *pio, spa_t *spa, uint64_t txg,
 483     const blkptr_t *bp,
 484     zio_done_func_t *done, void *private, enum zio_flag flags);
 485
 486 extern zio_t *zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
 487     zio_done_func_t *done, void *private, enum zio_flag flags);
 488
 489 extern zio_t *zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
 490     uint64_t size, void *data, int checksum,
 491     zio_done_func_t *done, void *private, zio_priority_t priority,
 492     enum zio_flag flags, boolean_t labels);
 493
 494 extern zio_t *zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
 495     uint64_t size, void *data, int checksum,
 496     zio_done_func_t *done, void *private, zio_priority_t priority,
 497     enum zio_flag flags, boolean_t labels);
 498
 499 extern zio_t *zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg,
 500     const blkptr_t *bp, enum zio_flag flags);
 501
 502 extern int zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp,
 503     uint64_t size, boolean_t use_slog);
 504 extern void zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp);
 505 extern void zio_flush(zio_t *zio, vdev_t *vd);
 506 extern void zio_shrink(zio_t *zio, uint64_t size);
 507
 508 extern int zio_wait(zio_t *zio);
 509 extern void zio_nowait(zio_t *zio);
 510 extern void zio_execute(zio_t *zio);
 511 extern void zio_interrupt(zio_t *zio);
 512
 513 extern zio_t *zio_walk_parents(zio_t *cio);
 514 extern zio_t *zio_walk_children(zio_t *pio);
 515 extern zio_t *zio_unique_parent(zio_t *cio);
 516 extern void zio_add_child(zio_t *pio, zio_t *cio);
 517
 518 extern void *zio_buf_alloc(size_t size);
 519 extern void zio_buf_free(void *buf, size_t size);
 520 extern void *zio_data_buf_alloc(size_t size);
 521 extern void zio_data_buf_free(void *buf, size_t size);
 522 extern void *zio_buf_alloc_flags(size_t size, int flags);
 523
 524 extern void zio_resubmit_stage_async(void *);
 525
 526 extern zio_t *zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd,
 527     uint64_t offset, void *data, uint64_t size, int type,
 528     zio_priority_t priority, enum zio_flag flags,
 529     zio_done_func_t *done, void *private);
 530
 531 extern zio_t *zio_vdev_delegated_io(vdev_t *vd, uint64_t offset,
 532     void *data, uint64_t size, int type, zio_priority_t priority,
 533     enum zio_flag flags, zio_done_func_t *done, void *private);
 534
 535 extern void zio_vdev_io_bypass(zio_t *zio);
 536 extern void zio_vdev_io_reissue(zio_t *zio);
 537 extern void zio_vdev_io_redone(zio_t *zio);
 538
 539 extern void zio_checksum_verified(zio_t *zio);
 540 extern int zio_worst_error(int e1, int e2);
 541
 542 extern enum zio_checksum zio_checksum_select(enum zio_checksum child,
 543     enum zio_checksum parent);
 544 extern enum zio_checksum zio_checksum_dedup_select(spa_t *spa,
 545     enum zio_checksum child, enum zio_checksum parent);
 546 extern enum zio_compress zio_compress_select(spa_t *spa,
 547     enum zio_compress child, enum zio_compress parent);
 548
 549 extern void zio_suspend(spa_t *spa, zio_t *zio);
 550 extern int zio_resume(spa_t *spa);
 551 extern void zio_resume_wait(spa_t *spa);
 552
 553 /*
 554  * Initial setup and teardown.
 555  */
 556 extern void zio_init(void);
 557 extern void zio_fini(void);
 558
 559 /*
 560  * Fault injection
 561  */
 562 struct zinject_record;
 563 extern uint32_t zio_injection_enabled;
 564 extern int zio_inject_fault(char *name, int flags, int *id,
 565     struct zinject_record *record);
 566 extern int zio_inject_list_next(int *id, char *name, size_t buflen,
 567     struct zinject_record *record);
 568 extern int zio_clear_fault(int id);
 569 extern void zio_handle_panic_injection(spa_t *spa, char *tag, uint64_t type);
 570 extern int zio_handle_fault_injection(zio_t *zio, int error);
 571 extern int zio_handle_device_injection(vdev_t *vd, zio_t *zio, int error);
 572 extern int zio_handle_label_injection(zio_t *zio, int error);
 573 extern void zio_handle_ignored_writes(zio_t *zio);
 574 extern uint64_t zio_handle_io_delay(zio_t *zio);
 575
 576 /*
 577  * Checksum ereport functions
 578  */
 579 extern void zfs_ereport_start_checksum(spa_t *spa, vdev_t *vd, struct zio *zio,
 580     uint64_t offset, uint64_t length, void *arg, struct zio_bad_cksum *info);
 581 extern void zfs_ereport_finish_checksum(zio_cksum_report_t *report,
 582     const void *good_data, const void *bad_data, boolean_t drop_if_identical);
 583
 584 extern void zfs_ereport_send_interim_checksum(zio_cksum_report_t *report);
 585 extern void zfs_ereport_free_checksum(zio_cksum_report_t *report);
 586
 587 /* If we have the good data in hand, this function can be used */
 588 extern void zfs_ereport_post_checksum(spa_t *spa, vdev_t *vd,
 589     struct zio *zio, uint64_t offset, uint64_t length,
 590     const void *good_data, const void *bad_data, struct zio_bad_cksum *info);
 591
 592 /* Called from spa_sync(), but primarily an injection handler */
 593 extern void spa_handle_ignored_writes(spa_t *spa);
 594
 595 /* zbookmark_phys functions */
 596 boolean_t zbookmark_subtree_completed(const struct dnode_phys *dnp,
 597     const zbookmark_phys_t *subtree_root, const zbookmark_phys_t *last_block);
 598 int zbookmark_compare(uint16_t dbss1, uint8_t ibs1, uint16_t dbss2,
 599     uint8_t ibs2, const zbookmark_phys_t *zb1, const zbookmark_phys_t *zb2);
 600
 601 #ifdef  __cplusplus
 602 }
 603 #endif
 604
 605 #endif  /* _ZIO_H */