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 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2011, 2018 by Delphix. All rights reserved. 24 * Copyright (c) 2017, Intel Corporation. 25 */ 26 27 #ifndef _SYS_VDEV_IMPL_H 28 #define _SYS_VDEV_IMPL_H 29 30 #include <sys/avl.h> 31 #include <sys/bpobj.h> 32 #include <sys/dmu.h> 33 #include <sys/metaslab.h> 34 #include <sys/nvpair.h> 35 #include <sys/space_map.h> 36 #include <sys/vdev.h> 37 #include <sys/dkio.h> 38 #include <sys/uberblock_impl.h> 39 #include <sys/vdev_indirect_mapping.h> 40 #include <sys/vdev_indirect_births.h> 41 #include <sys/vdev_removal.h> 42 43 #ifdef __cplusplus 44 extern "C" { 45 #endif 46 47 /* 48 * Virtual device descriptors. 49 * 50 * All storage pool operations go through the virtual device framework, 51 * which provides data replication and I/O scheduling. 52 */ 53 54 /* 55 * Forward declarations that lots of things need. 56 */ 57 typedef struct vdev_queue vdev_queue_t; 58 typedef struct vdev_cache vdev_cache_t; 59 typedef struct vdev_cache_entry vdev_cache_entry_t; 60 struct abd; 61 62 extern int zfs_vdev_queue_depth_pct; 63 extern int zfs_vdev_def_queue_depth; 64 extern uint32_t zfs_vdev_async_write_max_active; 65 66 /* 67 * Virtual device operations 68 */ 69 typedef int vdev_open_func_t(vdev_t *vd, uint64_t *size, uint64_t *max_size, 70 uint64_t *logical_ashift, uint64_t *physical_ashift); 71 typedef void vdev_close_func_t(vdev_t *vd); 72 typedef uint64_t vdev_asize_func_t(vdev_t *vd, uint64_t psize); 73 typedef void vdev_io_start_func_t(zio_t *zio); 74 typedef void vdev_io_done_func_t(zio_t *zio); 75 typedef void vdev_state_change_func_t(vdev_t *vd, int, int); 76 typedef boolean_t vdev_need_resilver_func_t(vdev_t *vd, uint64_t, size_t); 77 typedef void vdev_hold_func_t(vdev_t *vd); 78 typedef void vdev_rele_func_t(vdev_t *vd); 79 80 typedef void vdev_remap_cb_t(uint64_t inner_offset, vdev_t *vd, 81 uint64_t offset, uint64_t size, void *arg); 82 typedef void vdev_remap_func_t(vdev_t *vd, uint64_t offset, uint64_t size, 83 vdev_remap_cb_t callback, void *arg); 84 /* 85 * Given a target vdev, translates the logical range "in" to the physical 86 * range "res" 87 */ 88 typedef void vdev_xlation_func_t(vdev_t *cvd, const range_seg_t *in, 89 range_seg_t *res); 90 91 typedef struct vdev_ops { 92 vdev_open_func_t *vdev_op_open; 93 vdev_close_func_t *vdev_op_close; 94 vdev_asize_func_t *vdev_op_asize; 95 vdev_io_start_func_t *vdev_op_io_start; 96 vdev_io_done_func_t *vdev_op_io_done; 97 vdev_state_change_func_t *vdev_op_state_change; 98 vdev_need_resilver_func_t *vdev_op_need_resilver; 99 vdev_hold_func_t *vdev_op_hold; 100 vdev_rele_func_t *vdev_op_rele; 101 vdev_remap_func_t *vdev_op_remap; 102 /* 103 * For translating ranges from non-leaf vdevs (e.g. raidz) to leaves. 104 * Used when initializing vdevs. Isn't used by leaf ops. 105 */ 106 vdev_xlation_func_t *vdev_op_xlate; 107 char vdev_op_type[16]; 108 boolean_t vdev_op_leaf; 109 } vdev_ops_t; 110 111 /* 112 * Virtual device properties 113 */ 114 struct vdev_cache_entry { 115 struct abd *ve_abd; 116 uint64_t ve_offset; 117 uint64_t ve_lastused; 118 avl_node_t ve_offset_node; 119 avl_node_t ve_lastused_node; 120 uint32_t ve_hits; 121 uint16_t ve_missed_update; 122 zio_t *ve_fill_io; 123 }; 124 125 struct vdev_cache { 126 avl_tree_t vc_offset_tree; 127 avl_tree_t vc_lastused_tree; 128 kmutex_t vc_lock; 129 }; 130 131 typedef struct vdev_queue_class { 132 uint32_t vqc_active; 133 134 /* 135 * Sorted by offset or timestamp, depending on if the queue is 136 * LBA-ordered vs FIFO. 137 */ 138 avl_tree_t vqc_queued_tree; 139 } vdev_queue_class_t; 140 141 struct vdev_queue { 142 vdev_t *vq_vdev; 143 vdev_queue_class_t vq_class[ZIO_PRIORITY_NUM_QUEUEABLE]; 144 avl_tree_t vq_active_tree; 145 avl_tree_t vq_read_offset_tree; 146 avl_tree_t vq_write_offset_tree; 147 uint64_t vq_last_offset; 148 hrtime_t vq_io_complete_ts; /* time last i/o completed */ 149 kmutex_t vq_lock; 150 uint64_t vq_lastoffset; 151 }; 152 153 typedef enum vdev_alloc_bias { 154 VDEV_BIAS_NONE, 155 VDEV_BIAS_LOG, /* dedicated to ZIL data (SLOG) */ 156 VDEV_BIAS_SPECIAL, /* dedicated to ddt, metadata, and small blks */ 157 VDEV_BIAS_DEDUP /* dedicated to dedup metadata */ 158 } vdev_alloc_bias_t; 159 160 161 /* 162 * On-disk indirect vdev state. 163 * 164 * An indirect vdev is described exclusively in the MOS config of a pool. 165 * The config for an indirect vdev includes several fields, which are 166 * accessed in memory by a vdev_indirect_config_t. 167 */ 168 typedef struct vdev_indirect_config { 169 /* 170 * Object (in MOS) which contains the indirect mapping. This object 171 * contains an array of vdev_indirect_mapping_entry_phys_t ordered by 172 * vimep_src. The bonus buffer for this object is a 173 * vdev_indirect_mapping_phys_t. This object is allocated when a vdev 174 * removal is initiated. 175 * 176 * Note that this object can be empty if none of the data on the vdev 177 * has been copied yet. 178 */ 179 uint64_t vic_mapping_object; 180 181 /* 182 * Object (in MOS) which contains the birth times for the mapping 183 * entries. This object contains an array of 184 * vdev_indirect_birth_entry_phys_t sorted by vibe_offset. The bonus 185 * buffer for this object is a vdev_indirect_birth_phys_t. This object 186 * is allocated when a vdev removal is initiated. 187 * 188 * Note that this object can be empty if none of the vdev has yet been 189 * copied. 190 */ 191 uint64_t vic_births_object; 192 193 /* 194 * This is the vdev ID which was removed previous to this vdev, or 195 * UINT64_MAX if there are no previously removed vdevs. 196 */ 197 uint64_t vic_prev_indirect_vdev; 198 } vdev_indirect_config_t; 199 200 /* 201 * Virtual device descriptor 202 */ 203 struct vdev { 204 /* 205 * Common to all vdev types. 206 */ 207 uint64_t vdev_id; /* child number in vdev parent */ 208 uint64_t vdev_guid; /* unique ID for this vdev */ 209 uint64_t vdev_guid_sum; /* self guid + all child guids */ 210 uint64_t vdev_orig_guid; /* orig. guid prior to remove */ 211 uint64_t vdev_asize; /* allocatable device capacity */ 212 uint64_t vdev_min_asize; /* min acceptable asize */ 213 uint64_t vdev_max_asize; /* max acceptable asize */ 214 uint64_t vdev_ashift; /* block alignment shift */ 215 /* 216 * Logical block alignment shift 217 * 218 * The smallest sized/aligned I/O supported by the device. 219 */ 220 uint64_t vdev_logical_ashift; 221 /* 222 * Physical block alignment shift 223 * 224 * The device supports logical I/Os with vdev_logical_ashift 225 * size/alignment, but optimum performance will be achieved by 226 * aligning/sizing requests to vdev_physical_ashift. Smaller 227 * requests may be inflated or incur device level read-modify-write 228 * operations. 229 * 230 * May be 0 to indicate no preference (i.e. use vdev_logical_ashift). 231 */ 232 uint64_t vdev_physical_ashift; 233 uint64_t vdev_state; /* see VDEV_STATE_* #defines */ 234 uint64_t vdev_prevstate; /* used when reopening a vdev */ 235 vdev_ops_t *vdev_ops; /* vdev operations */ 236 spa_t *vdev_spa; /* spa for this vdev */ 237 void *vdev_tsd; /* type-specific data */ 238 vnode_t *vdev_name_vp; /* vnode for pathname */ 239 vnode_t *vdev_devid_vp; /* vnode for devid */ 240 vdev_t *vdev_top; /* top-level vdev */ 241 vdev_t *vdev_parent; /* parent vdev */ 242 vdev_t **vdev_child; /* array of children */ 243 uint64_t vdev_children; /* number of children */ 244 vdev_stat_t vdev_stat; /* virtual device statistics */ 245 boolean_t vdev_expanding; /* expand the vdev? */ 246 boolean_t vdev_reopening; /* reopen in progress? */ 247 boolean_t vdev_nonrot; /* true if solid state */ 248 int vdev_open_error; /* error on last open */ 249 kthread_t *vdev_open_thread; /* thread opening children */ 250 uint64_t vdev_crtxg; /* txg when top-level was added */ 251 252 /* 253 * Top-level vdev state. 254 */ 255 uint64_t vdev_ms_array; /* metaslab array object */ 256 uint64_t vdev_ms_shift; /* metaslab size shift */ 257 uint64_t vdev_ms_count; /* number of metaslabs */ 258 metaslab_group_t *vdev_mg; /* metaslab group */ 259 metaslab_t **vdev_ms; /* metaslab array */ 260 txg_list_t vdev_ms_list; /* per-txg dirty metaslab lists */ 261 txg_list_t vdev_dtl_list; /* per-txg dirty DTL lists */ 262 txg_node_t vdev_txg_node; /* per-txg dirty vdev linkage */ 263 boolean_t vdev_remove_wanted; /* async remove wanted? */ 264 boolean_t vdev_probe_wanted; /* async probe wanted? */ 265 list_node_t vdev_config_dirty_node; /* config dirty list */ 266 list_node_t vdev_state_dirty_node; /* state dirty list */ 267 uint64_t vdev_deflate_ratio; /* deflation ratio (x512) */ 268 uint64_t vdev_islog; /* is an intent log device */ 269 uint64_t vdev_removing; /* device is being removed? */ 270 boolean_t vdev_ishole; /* is a hole in the namespace */ 271 uint64_t vdev_top_zap; 272 vdev_alloc_bias_t vdev_alloc_bias; /* metaslab allocation bias */ 273 274 /* pool checkpoint related */ 275 space_map_t *vdev_checkpoint_sm; /* contains reserved blocks */ 276 277 boolean_t vdev_initialize_exit_wanted; 278 vdev_initializing_state_t vdev_initialize_state; 279 kthread_t *vdev_initialize_thread; 280 /* Protects vdev_initialize_thread and vdev_initialize_state. */ 281 kmutex_t vdev_initialize_lock; 282 kcondvar_t vdev_initialize_cv; 283 uint64_t vdev_initialize_offset[TXG_SIZE]; 284 uint64_t vdev_initialize_last_offset; 285 range_tree_t *vdev_initialize_tree; /* valid while initializing */ 286 uint64_t vdev_initialize_bytes_est; 287 uint64_t vdev_initialize_bytes_done; 288 time_t vdev_initialize_action_time; /* start and end time */ 289 290 /* for limiting outstanding I/Os */ 291 kmutex_t vdev_initialize_io_lock; 292 kcondvar_t vdev_initialize_io_cv; 293 uint64_t vdev_initialize_inflight; 294 295 /* 296 * Values stored in the config for an indirect or removing vdev. 297 */ 298 vdev_indirect_config_t vdev_indirect_config; 299 300 /* 301 * The vdev_indirect_rwlock protects the vdev_indirect_mapping 302 * pointer from changing on indirect vdevs (when it is condensed). 303 * Note that removing (not yet indirect) vdevs have different 304 * access patterns (the mapping is not accessed from open context, 305 * e.g. from zio_read) and locking strategy (e.g. svr_lock). 306 */ 307 krwlock_t vdev_indirect_rwlock; 308 vdev_indirect_mapping_t *vdev_indirect_mapping; 309 vdev_indirect_births_t *vdev_indirect_births; 310 311 /* 312 * In memory data structures used to manage the obsolete sm, for 313 * indirect or removing vdevs. 314 * 315 * The vdev_obsolete_segments is the in-core record of the segments 316 * that are no longer referenced anywhere in the pool (due to 317 * being freed or remapped and not referenced by any snapshots). 318 * During a sync, segments are added to vdev_obsolete_segments 319 * via vdev_indirect_mark_obsolete(); at the end of each sync 320 * pass, this is appended to vdev_obsolete_sm via 321 * vdev_indirect_sync_obsolete(). The vdev_obsolete_lock 322 * protects against concurrent modifications of vdev_obsolete_segments 323 * from multiple zio threads. 324 */ 325 kmutex_t vdev_obsolete_lock; 326 range_tree_t *vdev_obsolete_segments; 327 space_map_t *vdev_obsolete_sm; 328 329 /* 330 * Protects the vdev_scan_io_queue field itself as well as the 331 * structure's contents (when present). 332 */ 333 kmutex_t vdev_scan_io_queue_lock; 334 struct dsl_scan_io_queue *vdev_scan_io_queue; 335 336 /* 337 * Leaf vdev state. 338 */ 339 range_tree_t *vdev_dtl[DTL_TYPES]; /* dirty time logs */ 340 space_map_t *vdev_dtl_sm; /* dirty time log space map */ 341 txg_node_t vdev_dtl_node; /* per-txg dirty DTL linkage */ 342 uint64_t vdev_dtl_object; /* DTL object */ 343 uint64_t vdev_psize; /* physical device capacity */ 344 uint64_t vdev_wholedisk; /* true if this is a whole disk */ 345 uint64_t vdev_offline; /* persistent offline state */ 346 uint64_t vdev_faulted; /* persistent faulted state */ 347 uint64_t vdev_degraded; /* persistent degraded state */ 348 uint64_t vdev_removed; /* persistent removed state */ 349 uint64_t vdev_resilver_txg; /* persistent resilvering state */ 350 uint64_t vdev_nparity; /* number of parity devices for raidz */ 351 char *vdev_path; /* vdev path (if any) */ 352 char *vdev_devid; /* vdev devid (if any) */ 353 char *vdev_physpath; /* vdev device path (if any) */ 354 char *vdev_fru; /* physical FRU location */ 355 uint64_t vdev_not_present; /* not present during import */ 356 uint64_t vdev_unspare; /* unspare when resilvering done */ 357 boolean_t vdev_nowritecache; /* true if flushwritecache failed */ 358 boolean_t vdev_notrim; /* true if trim failed */ 359 boolean_t vdev_checkremove; /* temporary online test */ 360 boolean_t vdev_forcefault; /* force online fault */ 361 boolean_t vdev_splitting; /* split or repair in progress */ 362 boolean_t vdev_delayed_close; /* delayed device close? */ 363 boolean_t vdev_tmpoffline; /* device taken offline temporarily? */ 364 boolean_t vdev_detached; /* device detached? */ 365 boolean_t vdev_cant_read; /* vdev is failing all reads */ 366 boolean_t vdev_cant_write; /* vdev is failing all writes */ 367 boolean_t vdev_isspare; /* was a hot spare */ 368 boolean_t vdev_isl2cache; /* was a l2cache device */ 369 vdev_queue_t vdev_queue; /* I/O deadline schedule queue */ 370 vdev_cache_t vdev_cache; /* physical block cache */ 371 spa_aux_vdev_t *vdev_aux; /* for l2cache and spares vdevs */ 372 zio_t *vdev_probe_zio; /* root of current probe */ 373 vdev_aux_t vdev_label_aux; /* on-disk aux state */ 374 struct trim_map *vdev_trimmap; /* map on outstanding trims */ 375 uint64_t vdev_leaf_zap; 376 hrtime_t vdev_mmp_pending; /* 0 if write finished */ 377 uint64_t vdev_mmp_kstat_id; /* to find kstat entry */ 378 list_node_t vdev_leaf_node; /* leaf vdev list */ 379 380 /* 381 * For DTrace to work in userland (libzpool) context, these fields must 382 * remain at the end of the structure. DTrace will use the kernel's 383 * CTF definition for 'struct vdev', and since the size of a kmutex_t is 384 * larger in userland, the offsets for the rest of the fields would be 385 * incorrect. 386 */ 387 kmutex_t vdev_dtl_lock; /* vdev_dtl_{map,resilver} */ 388 kmutex_t vdev_stat_lock; /* vdev_stat */ 389 kmutex_t vdev_probe_lock; /* protects vdev_probe_zio */ 390 }; 391 392 #define VDEV_RAIDZ_MAXPARITY 3 393 394 #define VDEV_PAD_SIZE (8 << 10) 395 /* 2 padding areas (vl_pad1 and vl_pad2) to skip */ 396 #define VDEV_SKIP_SIZE VDEV_PAD_SIZE * 2 397 #define VDEV_PHYS_SIZE (112 << 10) 398 #define VDEV_UBERBLOCK_RING (128 << 10) 399 400 /* 401 * MMP blocks occupy the last MMP_BLOCKS_PER_LABEL slots in the uberblock 402 * ring when MMP is enabled. 403 */ 404 #define MMP_BLOCKS_PER_LABEL 1 405 406 /* The largest uberblock we support is 8k. */ 407 #define MAX_UBERBLOCK_SHIFT (13) 408 #define VDEV_UBERBLOCK_SHIFT(vd) \ 409 MIN(MAX((vd)->vdev_top->vdev_ashift, UBERBLOCK_SHIFT), \ 410 MAX_UBERBLOCK_SHIFT) 411 #define VDEV_UBERBLOCK_COUNT(vd) \ 412 (VDEV_UBERBLOCK_RING >> VDEV_UBERBLOCK_SHIFT(vd)) 413 #define VDEV_UBERBLOCK_OFFSET(vd, n) \ 414 offsetof(vdev_label_t, vl_uberblock[(n) << VDEV_UBERBLOCK_SHIFT(vd)]) 415 #define VDEV_UBERBLOCK_SIZE(vd) (1ULL << VDEV_UBERBLOCK_SHIFT(vd)) 416 417 typedef struct vdev_phys { 418 char vp_nvlist[VDEV_PHYS_SIZE - sizeof (zio_eck_t)]; 419 zio_eck_t vp_zbt; 420 } vdev_phys_t; 421 422 typedef struct vdev_label { 423 char vl_pad1[VDEV_PAD_SIZE]; /* 8K */ 424 char vl_pad2[VDEV_PAD_SIZE]; /* 8K */ 425 vdev_phys_t vl_vdev_phys; /* 112K */ 426 char vl_uberblock[VDEV_UBERBLOCK_RING]; /* 128K */ 427 } vdev_label_t; /* 256K total */ 428 429 /* 430 * vdev_dirty() flags 431 */ 432 #define VDD_METASLAB 0x01 433 #define VDD_DTL 0x02 434 435 /* Offset of embedded boot loader region on each label */ 436 #define VDEV_BOOT_OFFSET (2 * sizeof (vdev_label_t)) 437 /* 438 * Size of embedded boot loader region on each label. 439 * The total size of the first two labels plus the boot area is 4MB. 440 */ 441 #define VDEV_BOOT_SIZE (7ULL << 19) /* 3.5M */ 442 443 /* 444 * Size of label regions at the start and end of each leaf device. 445 */ 446 #define VDEV_LABEL_START_SIZE (2 * sizeof (vdev_label_t) + VDEV_BOOT_SIZE) 447 #define VDEV_LABEL_END_SIZE (2 * sizeof (vdev_label_t)) 448 #define VDEV_LABELS 4 449 #define VDEV_BEST_LABEL VDEV_LABELS 450 451 #define VDEV_ALLOC_LOAD 0 452 #define VDEV_ALLOC_ADD 1 453 #define VDEV_ALLOC_SPARE 2 454 #define VDEV_ALLOC_L2CACHE 3 455 #define VDEV_ALLOC_ROOTPOOL 4 456 #define VDEV_ALLOC_SPLIT 5 457 #define VDEV_ALLOC_ATTACH 6 458 459 /* 460 * Allocate or free a vdev 461 */ 462 extern vdev_t *vdev_alloc_common(spa_t *spa, uint_t id, uint64_t guid, 463 vdev_ops_t *ops); 464 extern int vdev_alloc(spa_t *spa, vdev_t **vdp, nvlist_t *config, 465 vdev_t *parent, uint_t id, int alloctype); 466 extern void vdev_free(vdev_t *vd); 467 468 /* 469 * Add or remove children and parents 470 */ 471 extern void vdev_add_child(vdev_t *pvd, vdev_t *cvd); 472 extern void vdev_remove_child(vdev_t *pvd, vdev_t *cvd); 473 extern void vdev_compact_children(vdev_t *pvd); 474 extern vdev_t *vdev_add_parent(vdev_t *cvd, vdev_ops_t *ops); 475 extern void vdev_remove_parent(vdev_t *cvd); 476 477 /* 478 * vdev sync load and sync 479 */ 480 extern boolean_t vdev_log_state_valid(vdev_t *vd); 481 extern int vdev_load(vdev_t *vd); 482 extern int vdev_dtl_load(vdev_t *vd); 483 extern void vdev_sync(vdev_t *vd, uint64_t txg); 484 extern void vdev_sync_done(vdev_t *vd, uint64_t txg); 485 extern void vdev_dirty(vdev_t *vd, int flags, void *arg, uint64_t txg); 486 extern void vdev_dirty_leaves(vdev_t *vd, int flags, uint64_t txg); 487 488 /* 489 * Available vdev types. 490 */ 491 extern vdev_ops_t vdev_root_ops; 492 extern vdev_ops_t vdev_mirror_ops; 493 extern vdev_ops_t vdev_replacing_ops; 494 extern vdev_ops_t vdev_raidz_ops; 495 #ifdef _KERNEL 496 extern vdev_ops_t vdev_geom_ops; 497 #else 498 extern vdev_ops_t vdev_disk_ops; 499 #endif 500 extern vdev_ops_t vdev_file_ops; 501 extern vdev_ops_t vdev_missing_ops; 502 extern vdev_ops_t vdev_hole_ops; 503 extern vdev_ops_t vdev_spare_ops; 504 extern vdev_ops_t vdev_indirect_ops; 505 506 /* 507 * Common size functions 508 */ 509 extern void vdev_default_xlate(vdev_t *vd, const range_seg_t *in, 510 range_seg_t *out); 511 extern uint64_t vdev_default_asize(vdev_t *vd, uint64_t psize); 512 extern uint64_t vdev_get_min_asize(vdev_t *vd); 513 extern void vdev_set_min_asize(vdev_t *vd); 514 515 /* 516 * Global variables 517 */ 518 extern int vdev_standard_sm_blksz; 519 /* zdb uses this tunable, so it must be declared here to make lint happy. */ 520 extern int zfs_vdev_cache_size; 521 extern uint_t zfs_geom_probe_vdev_key; 522 523 /* 524 * Functions from vdev_indirect.c 525 */ 526 extern void vdev_indirect_sync_obsolete(vdev_t *vd, dmu_tx_t *tx); 527 extern boolean_t vdev_indirect_should_condense(vdev_t *vd); 528 extern void spa_condense_indirect_start_sync(vdev_t *vd, dmu_tx_t *tx); 529 extern int vdev_obsolete_sm_object(vdev_t *vd); 530 extern boolean_t vdev_obsolete_counts_are_precise(vdev_t *vd); 531 532 #ifdef illumos 533 /* 534 * Other miscellaneous functions 535 */ 536 int vdev_checkpoint_sm_object(vdev_t *vd); 537 538 /* 539 * The vdev_buf_t is used to translate between zio_t and buf_t, and back again. 540 */ 541 typedef struct vdev_buf { 542 buf_t vb_buf; /* buffer that describes the io */ 543 zio_t *vb_io; /* pointer back to the original zio_t */ 544 } vdev_buf_t; 545 #endif 546 547 #ifdef __cplusplus 548 } 549 #endif 550 551 #endif /* _SYS_VDEV_IMPL_H */ 552