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 2009 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #ifndef _ZIO_H 28 #define _ZIO_H 29 30 #include <sys/zfs_context.h> 31 #include <sys/spa.h> 32 #include <sys/txg.h> 33 #include <sys/avl.h> 34 #include <sys/fs/zfs.h> 35 #include <sys/zio_impl.h> 36 37 #ifdef __cplusplus 38 extern "C" { 39 #endif 40 41 #define ZBT_MAGIC 0x210da7ab10c7a11ULL /* zio data bloc tail */ 42 43 typedef struct zio_block_tail { 44 uint64_t zbt_magic; /* for validation, endianness */ 45 zio_cksum_t zbt_cksum; /* 256-bit checksum */ 46 } zio_block_tail_t; 47 48 /* 49 * Gang block headers are self-checksumming and contain an array 50 * of block pointers. 51 */ 52 #define SPA_GANGBLOCKSIZE SPA_MINBLOCKSIZE 53 #define SPA_GBH_NBLKPTRS ((SPA_GANGBLOCKSIZE - \ 54 sizeof (zio_block_tail_t)) / sizeof (blkptr_t)) 55 #define SPA_GBH_FILLER ((SPA_GANGBLOCKSIZE - \ 56 sizeof (zio_block_tail_t) - \ 57 (SPA_GBH_NBLKPTRS * sizeof (blkptr_t))) /\ 58 sizeof (uint64_t)) 59 60 typedef struct zio_gbh { 61 blkptr_t zg_blkptr[SPA_GBH_NBLKPTRS]; 62 uint64_t zg_filler[SPA_GBH_FILLER]; 63 zio_block_tail_t zg_tail; 64 } zio_gbh_phys_t; 65 66 enum zio_checksum { 67 ZIO_CHECKSUM_INHERIT = 0, 68 ZIO_CHECKSUM_ON, 69 ZIO_CHECKSUM_OFF, 70 ZIO_CHECKSUM_LABEL, 71 ZIO_CHECKSUM_GANG_HEADER, 72 ZIO_CHECKSUM_ZILOG, 73 ZIO_CHECKSUM_FLETCHER_2, 74 ZIO_CHECKSUM_FLETCHER_4, 75 ZIO_CHECKSUM_SHA256, 76 ZIO_CHECKSUM_FUNCTIONS 77 }; 78 79 #define ZIO_CHECKSUM_ON_VALUE ZIO_CHECKSUM_FLETCHER_4 80 #define ZIO_CHECKSUM_DEFAULT ZIO_CHECKSUM_ON 81 82 #define ZIO_CHECKSUM_MASK 0xffULL 83 #define ZIO_CHECKSUM_VERIFY (1 << 8) 84 85 #define ZIO_DEDUPCHECKSUM ZIO_CHECKSUM_SHA256 86 #define ZIO_DEDUPDITTO_MIN 100 87 88 enum zio_compress { 89 ZIO_COMPRESS_INHERIT = 0, 90 ZIO_COMPRESS_ON, 91 ZIO_COMPRESS_OFF, 92 ZIO_COMPRESS_LZJB, 93 ZIO_COMPRESS_EMPTY, 94 ZIO_COMPRESS_GZIP_1, 95 ZIO_COMPRESS_GZIP_2, 96 ZIO_COMPRESS_GZIP_3, 97 ZIO_COMPRESS_GZIP_4, 98 ZIO_COMPRESS_GZIP_5, 99 ZIO_COMPRESS_GZIP_6, 100 ZIO_COMPRESS_GZIP_7, 101 ZIO_COMPRESS_GZIP_8, 102 ZIO_COMPRESS_GZIP_9, 103 ZIO_COMPRESS_ZLE, 104 ZIO_COMPRESS_FUNCTIONS 105 }; 106 107 #define ZIO_COMPRESS_ON_VALUE ZIO_COMPRESS_LZJB 108 #define ZIO_COMPRESS_DEFAULT ZIO_COMPRESS_OFF 109 110 #define BOOTFS_COMPRESS_VALID(compress) \ 111 ((compress) == ZIO_COMPRESS_LZJB || \ 112 ((compress) == ZIO_COMPRESS_ON && \ 113 ZIO_COMPRESS_ON_VALUE == ZIO_COMPRESS_LZJB) || \ 114 (compress) == ZIO_COMPRESS_OFF) 115 116 #define ZIO_FAILURE_MODE_WAIT 0 117 #define ZIO_FAILURE_MODE_CONTINUE 1 118 #define ZIO_FAILURE_MODE_PANIC 2 119 120 #define ZIO_PRIORITY_NOW (zio_priority_table[0]) 121 #define ZIO_PRIORITY_SYNC_READ (zio_priority_table[1]) 122 #define ZIO_PRIORITY_SYNC_WRITE (zio_priority_table[2]) 123 #define ZIO_PRIORITY_ASYNC_READ (zio_priority_table[3]) 124 #define ZIO_PRIORITY_ASYNC_WRITE (zio_priority_table[4]) 125 #define ZIO_PRIORITY_FREE (zio_priority_table[5]) 126 #define ZIO_PRIORITY_CACHE_FILL (zio_priority_table[6]) 127 #define ZIO_PRIORITY_LOG_WRITE (zio_priority_table[7]) 128 #define ZIO_PRIORITY_RESILVER (zio_priority_table[8]) 129 #define ZIO_PRIORITY_SCRUB (zio_priority_table[9]) 130 #define ZIO_PRIORITY_TABLE_SIZE 10 131 132 #define ZIO_PIPELINE_CONTINUE 0x100 133 #define ZIO_PIPELINE_STOP 0x101 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_SCRUB_THREAD = 1 << 5, 146 147 #define ZIO_FLAG_AGG_INHERIT (ZIO_FLAG_CANFAIL - 1) 148 149 /* 150 * Flags inherited by ddt, gang, and vdev children. 151 */ 152 ZIO_FLAG_CANFAIL = 1 << 6, /* must be first for INHERIT */ 153 ZIO_FLAG_SPECULATIVE = 1 << 7, 154 ZIO_FLAG_CONFIG_WRITER = 1 << 8, 155 ZIO_FLAG_DONT_RETRY = 1 << 9, 156 ZIO_FLAG_DONT_CACHE = 1 << 10, 157 ZIO_FLAG_NODATA = 1 << 11, 158 ZIO_FLAG_INDUCE_DAMAGE = 1 << 12, 159 160 #define ZIO_FLAG_DDT_INHERIT (ZIO_FLAG_IO_RETRY - 1) 161 #define ZIO_FLAG_GANG_INHERIT (ZIO_FLAG_IO_RETRY - 1) 162 163 /* 164 * Flags inherited by vdev children. 165 */ 166 ZIO_FLAG_IO_RETRY = 1 << 13, /* must be first for INHERIT */ 167 ZIO_FLAG_PROBE = 1 << 14, 168 ZIO_FLAG_TRYHARD = 1 << 15, 169 ZIO_FLAG_OPTIONAL = 1 << 16, 170 171 #define ZIO_FLAG_VDEV_INHERIT (ZIO_FLAG_DONT_QUEUE - 1) 172 173 /* 174 * Flags not inherited by any children. 175 */ 176 ZIO_FLAG_DONT_QUEUE = 1 << 17, /* must be first for INHERIT */ 177 ZIO_FLAG_DONT_PROPAGATE = 1 << 18, 178 ZIO_FLAG_IO_BYPASS = 1 << 19, 179 ZIO_FLAG_IO_REWRITE = 1 << 20, 180 ZIO_FLAG_RAW = 1 << 21, 181 ZIO_FLAG_GANG_CHILD = 1 << 22, 182 ZIO_FLAG_DDT_CHILD = 1 << 23, 183 ZIO_FLAG_GODFATHER = 1 << 24 184 }; 185 186 #define ZIO_FLAG_MUSTSUCCEED 0 187 188 #define ZIO_DDT_CHILD_FLAGS(zio) \ 189 (((zio)->io_flags & ZIO_FLAG_DDT_INHERIT) | \ 190 ZIO_FLAG_DDT_CHILD | ZIO_FLAG_CANFAIL) 191 192 #define ZIO_GANG_CHILD_FLAGS(zio) \ 193 (((zio)->io_flags & ZIO_FLAG_GANG_INHERIT) | \ 194 ZIO_FLAG_GANG_CHILD | ZIO_FLAG_CANFAIL) 195 196 #define ZIO_VDEV_CHILD_FLAGS(zio) \ 197 (((zio)->io_flags & ZIO_FLAG_VDEV_INHERIT) | \ 198 ZIO_FLAG_CANFAIL) 199 200 enum zio_child { 201 ZIO_CHILD_VDEV = 0, 202 ZIO_CHILD_GANG, 203 ZIO_CHILD_DDT, 204 ZIO_CHILD_LOGICAL, 205 ZIO_CHILD_TYPES 206 }; 207 208 enum zio_wait_type { 209 ZIO_WAIT_READY = 0, 210 ZIO_WAIT_DONE, 211 ZIO_WAIT_TYPES 212 }; 213 214 /* 215 * We'll take the unused errnos, 'EBADE' and 'EBADR' (from the Convergent 216 * graveyard) to indicate checksum errors and fragmentation. 217 */ 218 #define ECKSUM EBADE 219 #define EFRAGS EBADR 220 221 typedef void zio_done_func_t(zio_t *zio); 222 223 extern uint8_t zio_priority_table[ZIO_PRIORITY_TABLE_SIZE]; 224 extern char *zio_type_name[ZIO_TYPES]; 225 226 /* 227 * A bookmark is a four-tuple <objset, object, level, blkid> that uniquely 228 * identifies any block in the pool. By convention, the meta-objset (MOS) 229 * is objset 0, and the meta-dnode is object 0. This covers all blocks 230 * except root blocks and ZIL blocks, which are defined as follows: 231 * 232 * Root blocks (objset_phys_t) are object 0, level -1: <objset, 0, -1, 0>. 233 * ZIL blocks are bookmarked <objset, 0, -2, blkid == ZIL sequence number>. 234 * dmu_sync()ed ZIL data blocks are bookmarked <objset, object, -2, blkid>. 235 * 236 * Note: this structure is called a bookmark because its original purpose 237 * was to remember where to resume a pool-wide traverse. 238 * 239 * Note: this structure is passed between userland and the kernel. 240 * Therefore it must not change size or alignment between 32/64 bit 241 * compilation options. 242 */ 243 typedef struct zbookmark { 244 uint64_t zb_objset; 245 uint64_t zb_object; 246 int64_t zb_level; 247 uint64_t zb_blkid; 248 } zbookmark_t; 249 250 #define SET_BOOKMARK(zb, objset, object, level, blkid) \ 251 { \ 252 (zb)->zb_objset = objset; \ 253 (zb)->zb_object = object; \ 254 (zb)->zb_level = level; \ 255 (zb)->zb_blkid = blkid; \ 256 } 257 258 #define ZB_DESTROYED_OBJSET (-1ULL) 259 260 #define ZB_ROOT_OBJECT (0ULL) 261 #define ZB_ROOT_LEVEL (-1LL) 262 #define ZB_ROOT_BLKID (0ULL) 263 264 #define ZB_ZIL_OBJECT (0ULL) 265 #define ZB_ZIL_LEVEL (-2LL) 266 267 typedef struct zio_prop { 268 enum zio_checksum zp_checksum; 269 enum zio_compress zp_compress; 270 dmu_object_type_t zp_type; 271 uint8_t zp_level; 272 uint8_t zp_copies; 273 uint8_t zp_dedup; 274 uint8_t zp_dedup_verify; 275 } zio_prop_t; 276 277 typedef struct zio_cksum_report zio_cksum_report_t; 278 279 typedef void zio_cksum_finish_f(zio_cksum_report_t *rep, 280 const void *good_data); 281 typedef void zio_cksum_free_f(void *cbdata, size_t size); 282 283 struct zio_bad_cksum; /* defined in zio_checksum.h */ 284 285 struct zio_cksum_report { 286 struct zio_cksum_report *zcr_next; 287 nvlist_t *zcr_ereport; 288 nvlist_t *zcr_detector; 289 void *zcr_cbdata; 290 size_t zcr_cbinfo; /* passed to zcr_free() */ 291 uint64_t zcr_align; 292 uint64_t zcr_length; 293 zio_cksum_finish_f *zcr_finish; 294 zio_cksum_free_f *zcr_free; 295 296 /* internal use only */ 297 struct zio_bad_cksum *zcr_ckinfo; /* information from failure */ 298 }; 299 300 typedef void zio_vsd_cksum_report_f(zio_t *zio, zio_cksum_report_t *zcr, 301 void *arg); 302 303 zio_vsd_cksum_report_f zio_vsd_default_cksum_report; 304 305 typedef struct zio_vsd_ops { 306 zio_done_func_t *vsd_free; 307 zio_vsd_cksum_report_f *vsd_cksum_report; 308 } zio_vsd_ops_t; 309 310 typedef struct zio_gang_node { 311 zio_gbh_phys_t *gn_gbh; 312 struct zio_gang_node *gn_child[SPA_GBH_NBLKPTRS]; 313 } zio_gang_node_t; 314 315 typedef zio_t *zio_gang_issue_func_t(zio_t *zio, blkptr_t *bp, 316 zio_gang_node_t *gn, void *data); 317 318 typedef void zio_transform_func_t(zio_t *zio, void *data, uint64_t size); 319 320 typedef struct zio_transform { 321 void *zt_orig_data; 322 uint64_t zt_orig_size; 323 uint64_t zt_bufsize; 324 zio_transform_func_t *zt_transform; 325 struct zio_transform *zt_next; 326 } zio_transform_t; 327 328 typedef int zio_pipe_stage_t(zio_t *zio); 329 330 /* 331 * The io_reexecute flags are distinct from io_flags because the child must 332 * be able to propagate them to the parent. The normal io_flags are local 333 * to the zio, not protected by any lock, and not modifiable by children; 334 * the reexecute flags are protected by io_lock, modifiable by children, 335 * and always propagated -- even when ZIO_FLAG_DONT_PROPAGATE is set. 336 */ 337 #define ZIO_REEXECUTE_NOW 0x01 338 #define ZIO_REEXECUTE_SUSPEND 0x02 339 340 typedef struct zio_link { 341 zio_t *zl_parent; 342 zio_t *zl_child; 343 list_node_t zl_parent_node; 344 list_node_t zl_child_node; 345 } zio_link_t; 346 347 struct zio { 348 /* Core information about this I/O */ 349 zbookmark_t io_bookmark; 350 zio_prop_t io_prop; 351 zio_type_t io_type; 352 enum zio_child io_child_type; 353 int io_cmd; 354 uint8_t io_priority; 355 uint8_t io_reexecute; 356 uint8_t io_state[ZIO_WAIT_TYPES]; 357 uint64_t io_txg; 358 spa_t *io_spa; 359 blkptr_t *io_bp; 360 blkptr_t *io_bp_override; 361 blkptr_t io_bp_copy; 362 list_t io_parent_list; 363 list_t io_child_list; 364 zio_link_t *io_walk_link; 365 zio_t *io_logical; 366 zio_transform_t *io_transform_stack; 367 368 /* Callback info */ 369 zio_done_func_t *io_ready; 370 zio_done_func_t *io_done; 371 void *io_private; 372 int64_t io_prev_space_delta; /* DMU private */ 373 blkptr_t io_bp_orig; 374 375 /* Data represented by this I/O */ 376 void *io_data; 377 void *io_orig_data; 378 uint64_t io_size; 379 uint64_t io_orig_size; 380 381 /* Stuff for the vdev stack */ 382 vdev_t *io_vd; 383 void *io_vsd; 384 const zio_vsd_ops_t *io_vsd_ops; 385 386 uint64_t io_offset; 387 uint64_t io_deadline; 388 avl_node_t io_offset_node; 389 avl_node_t io_deadline_node; 390 avl_tree_t *io_vdev_tree; 391 392 /* Internal pipeline state */ 393 enum zio_flag io_flags; 394 enum zio_stage io_stage; 395 enum zio_stage io_pipeline; 396 enum zio_flag io_orig_flags; 397 enum zio_stage io_orig_stage; 398 enum zio_stage io_orig_pipeline; 399 int io_error; 400 int io_child_error[ZIO_CHILD_TYPES]; 401 uint64_t io_children[ZIO_CHILD_TYPES][ZIO_WAIT_TYPES]; 402 uint64_t io_child_count; 403 uint64_t io_parent_count; 404 uint64_t *io_stall; 405 zio_t *io_gang_leader; 406 zio_gang_node_t *io_gang_tree; 407 void *io_executor; 408 void *io_waiter; 409 kmutex_t io_lock; 410 kcondvar_t io_cv; 411 412 /* FMA state */ 413 zio_cksum_report_t *io_cksum_report; 414 uint64_t io_ena; 415 }; 416 417 extern zio_t *zio_null(zio_t *pio, spa_t *spa, vdev_t *vd, 418 zio_done_func_t *done, void *private, enum zio_flag flags); 419 420 extern zio_t *zio_root(spa_t *spa, 421 zio_done_func_t *done, void *private, enum zio_flag flags); 422 423 extern zio_t *zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, void *data, 424 uint64_t size, zio_done_func_t *done, void *private, 425 int priority, enum zio_flag flags, const zbookmark_t *zb); 426 427 extern zio_t *zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, 428 void *data, uint64_t size, const zio_prop_t *zp, 429 zio_done_func_t *ready, zio_done_func_t *done, void *private, 430 int priority, enum zio_flag flags, const zbookmark_t *zb); 431 432 extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, 433 void *data, uint64_t size, zio_done_func_t *done, void *private, 434 int priority, enum zio_flag flags, zbookmark_t *zb); 435 436 extern void zio_write_override(zio_t *zio, blkptr_t *bp, int copies); 437 438 extern void zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp); 439 440 extern zio_t *zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, 441 const blkptr_t *bp, 442 zio_done_func_t *done, void *private, enum zio_flag flags); 443 444 extern zio_t *zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd, 445 zio_done_func_t *done, void *private, int priority, enum zio_flag flags); 446 447 extern zio_t *zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset, 448 uint64_t size, void *data, int checksum, 449 zio_done_func_t *done, void *private, int priority, enum zio_flag flags, 450 boolean_t labels); 451 452 extern zio_t *zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset, 453 uint64_t size, void *data, int checksum, 454 zio_done_func_t *done, void *private, int priority, enum zio_flag flags, 455 boolean_t labels); 456 457 extern zio_t *zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, 458 const blkptr_t *bp, enum zio_flag flags); 459 460 extern int zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp, 461 blkptr_t *old_bp, uint64_t size, boolean_t use_slog); 462 extern void zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp); 463 extern void zio_flush(zio_t *zio, vdev_t *vd); 464 465 extern int zio_wait(zio_t *zio); 466 extern void zio_nowait(zio_t *zio); 467 extern void zio_execute(zio_t *zio); 468 extern void zio_interrupt(zio_t *zio); 469 470 extern zio_t *zio_walk_parents(zio_t *cio); 471 extern zio_t *zio_walk_children(zio_t *pio); 472 extern zio_t *zio_unique_parent(zio_t *cio); 473 extern void zio_add_child(zio_t *pio, zio_t *cio); 474 475 extern void *zio_buf_alloc(size_t size); 476 extern void zio_buf_free(void *buf, size_t size); 477 extern void *zio_data_buf_alloc(size_t size); 478 extern void zio_data_buf_free(void *buf, size_t size); 479 480 extern void zio_resubmit_stage_async(void *); 481 482 extern zio_t *zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd, 483 uint64_t offset, void *data, uint64_t size, int type, int priority, 484 enum zio_flag flags, zio_done_func_t *done, void *private); 485 486 extern zio_t *zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, 487 void *data, uint64_t size, int type, int priority, 488 enum zio_flag flags, zio_done_func_t *done, void *private); 489 490 extern void zio_vdev_io_bypass(zio_t *zio); 491 extern void zio_vdev_io_reissue(zio_t *zio); 492 extern void zio_vdev_io_redone(zio_t *zio); 493 494 extern void zio_checksum_verified(zio_t *zio); 495 extern int zio_worst_error(int e1, int e2); 496 497 extern enum zio_checksum zio_checksum_select(enum zio_checksum child, 498 enum zio_checksum parent); 499 extern enum zio_checksum zio_checksum_dedup_select(spa_t *spa, 500 enum zio_checksum child, enum zio_checksum parent); 501 extern enum zio_compress zio_compress_select(enum zio_compress child, 502 enum zio_compress parent); 503 504 extern void zio_suspend(spa_t *spa, zio_t *zio); 505 extern int zio_resume(spa_t *spa); 506 extern void zio_resume_wait(spa_t *spa); 507 508 /* 509 * Initial setup and teardown. 510 */ 511 extern void zio_init(void); 512 extern void zio_fini(void); 513 514 /* 515 * Fault injection 516 */ 517 struct zinject_record; 518 extern uint32_t zio_injection_enabled; 519 extern int zio_inject_fault(char *name, int flags, int *id, 520 struct zinject_record *record); 521 extern int zio_inject_list_next(int *id, char *name, size_t buflen, 522 struct zinject_record *record); 523 extern int zio_clear_fault(int id); 524 extern void zio_handle_panic_injection(spa_t *spa, char *tag); 525 extern int zio_handle_fault_injection(zio_t *zio, int error); 526 extern int zio_handle_device_injection(vdev_t *vd, zio_t *zio, int error); 527 extern int zio_handle_label_injection(zio_t *zio, int error); 528 extern void zio_handle_ignored_writes(zio_t *zio); 529 530 /* 531 * Checksum ereport functions 532 */ 533 extern void zfs_ereport_start_checksum(spa_t *spa, vdev_t *vd, struct zio *zio, 534 uint64_t offset, uint64_t length, void *arg, struct zio_bad_cksum *info); 535 extern void zfs_ereport_finish_checksum(zio_cksum_report_t *report, 536 const void *good_data, const void *bad_data, boolean_t drop_if_identical); 537 538 extern void zfs_ereport_send_interim_checksum(zio_cksum_report_t *report); 539 extern void zfs_ereport_free_checksum(zio_cksum_report_t *report); 540 541 /* If we have the good data in hand, this function can be used */ 542 extern void zfs_ereport_post_checksum(spa_t *spa, vdev_t *vd, 543 struct zio *zio, uint64_t offset, uint64_t length, 544 const void *good_data, const void *bad_data, struct zio_bad_cksum *info); 545 546 /* Called from spa_sync(), but primarily an injection handler */ 547 extern void spa_handle_ignored_writes(spa_t *spa); 548 549 #ifdef __cplusplus 550 } 551 #endif 552 553 #endif /* _ZIO_H */ 554