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 https://opensource.org/licenses/CDDL-1.0. 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) 2012, 2020 by Delphix. All rights reserved. 24 * Copyright (c) 2013 by Saso Kiselkov. All rights reserved. 25 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. 26 */ 27 28#ifndef _SYS_DBUF_H 29#define _SYS_DBUF_H 30 31#include <sys/dmu.h> 32#include <sys/spa.h> 33#include <sys/txg.h> 34#include <sys/zio.h> 35#include <sys/arc.h> 36#include <sys/zfs_context.h> 37#include <sys/zfs_refcount.h> 38#include <sys/zrlock.h> 39#include <sys/multilist.h> 40 41#ifdef __cplusplus 42extern "C" { 43#endif 44 45#define IN_DMU_SYNC 2 46 47/* 48 * define flags for dbuf_read 49 */ 50 51#define DB_RF_MUST_SUCCEED (1 << 0) 52#define DB_RF_CANFAIL (1 << 1) 53#define DB_RF_HAVESTRUCT (1 << 2) 54#define DB_RF_NOPREFETCH (1 << 3) 55#define DB_RF_NEVERWAIT (1 << 4) 56#define DB_RF_CACHED (1 << 5) 57#define DB_RF_NO_DECRYPT (1 << 6) 58#define DB_RF_PARTIAL_FIRST (1 << 7) 59#define DB_RF_PARTIAL_MORE (1 << 8) 60 61/* 62 * The simplified state transition diagram for dbufs looks like: 63 * 64 * +--> READ --+ 65 * | | 66 * | V 67 * (alloc)-->UNCACHED CACHED-->EVICTING-->(free) 68 * ^ | ^ ^ 69 * | | | | 70 * | +--> FILL --+ | 71 * | | | 72 * | | | 73 * | +------> NOFILL -----+ 74 * | | 75 * +---------------+ 76 * 77 * DB_SEARCH is an invalid state for a dbuf. It is used by dbuf_free_range 78 * to find all dbufs in a range of a dnode and must be less than any other 79 * dbuf_states_t (see comment on dn_dbufs in dnode.h). 80 */ 81typedef enum dbuf_states { 82 DB_MARKER = -2, 83 DB_SEARCH = -1, 84 DB_UNCACHED, 85 DB_FILL, 86 DB_NOFILL, 87 DB_READ, 88 DB_CACHED, 89 DB_EVICTING 90} dbuf_states_t; 91 92typedef enum dbuf_cached_state { 93 DB_NO_CACHE = -1, 94 DB_DBUF_CACHE, 95 DB_DBUF_METADATA_CACHE, 96 DB_CACHE_MAX 97} dbuf_cached_state_t; 98 99struct dnode; 100struct dmu_tx; 101 102/* 103 * level = 0 means the user data 104 * level = 1 means the single indirect block 105 * etc. 106 */ 107 108struct dmu_buf_impl; 109 110typedef enum override_states { 111 DR_NOT_OVERRIDDEN, 112 DR_IN_DMU_SYNC, 113 DR_OVERRIDDEN 114} override_states_t; 115 116typedef enum db_lock_type { 117 DLT_NONE, 118 DLT_PARENT, 119 DLT_OBJSET 120} db_lock_type_t; 121 122typedef struct dbuf_dirty_record { 123 /* link on our parents dirty list */ 124 list_node_t dr_dirty_node; 125 126 /* transaction group this data will sync in */ 127 uint64_t dr_txg; 128 129 /* zio of outstanding write IO */ 130 zio_t *dr_zio; 131 132 /* pointer back to our dbuf */ 133 struct dmu_buf_impl *dr_dbuf; 134 135 /* list link for dbuf dirty records */ 136 list_node_t dr_dbuf_node; 137 138 /* 139 * The dnode we are part of. Note that the dnode can not be moved or 140 * evicted due to the hold that's added by dnode_setdirty() or 141 * dmu_objset_sync_dnodes(), and released by dnode_rele_task() or 142 * userquota_updates_task(). This hold is necessary for 143 * dirty_lightweight_leaf-type dirty records, which don't have a hold 144 * on a dbuf. 145 */ 146 dnode_t *dr_dnode; 147 148 /* pointer to parent dirty record */ 149 struct dbuf_dirty_record *dr_parent; 150 151 /* How much space was changed to dsl_pool_dirty_space() for this? */ 152 unsigned int dr_accounted; 153 154 /* A copy of the bp that points to us */ 155 blkptr_t dr_bp_copy; 156 157 union dirty_types { 158 struct dirty_indirect { 159 160 /* protect access to list */ 161 kmutex_t dr_mtx; 162 163 /* Our list of dirty children */ 164 list_t dr_children; 165 } di; 166 struct dirty_leaf { 167 168 /* 169 * dr_data is set when we dirty the buffer 170 * so that we can retain the pointer even if it 171 * gets COW'd in a subsequent transaction group. 172 */ 173 arc_buf_t *dr_data; 174 blkptr_t dr_overridden_by; 175 override_states_t dr_override_state; 176 uint8_t dr_copies; 177 boolean_t dr_nopwrite; 178 boolean_t dr_brtwrite; 179 boolean_t dr_has_raw_params; 180 181 /* 182 * If dr_has_raw_params is set, the following crypt 183 * params will be set on the BP that's written. 184 */ 185 boolean_t dr_byteorder; 186 uint8_t dr_salt[ZIO_DATA_SALT_LEN]; 187 uint8_t dr_iv[ZIO_DATA_IV_LEN]; 188 uint8_t dr_mac[ZIO_DATA_MAC_LEN]; 189 } dl; 190 struct dirty_lightweight_leaf { 191 /* 192 * This dirty record refers to a leaf (level=0) 193 * block, whose dbuf has not been instantiated for 194 * performance reasons. 195 */ 196 uint64_t dr_blkid; 197 abd_t *dr_abd; 198 zio_prop_t dr_props; 199 zio_flag_t dr_flags; 200 } dll; 201 } dt; 202} dbuf_dirty_record_t; 203 204typedef struct dmu_buf_impl { 205 /* 206 * The following members are immutable, with the exception of 207 * db.db_data, which is protected by db_mtx. 208 */ 209 210 /* the publicly visible structure */ 211 dmu_buf_t db; 212 213 /* the objset we belong to */ 214 struct objset *db_objset; 215 216 /* 217 * handle to safely access the dnode we belong to (NULL when evicted) 218 */ 219 struct dnode_handle *db_dnode_handle; 220 221 /* 222 * our parent buffer; if the dnode points to us directly, 223 * db_parent == db_dnode_handle->dnh_dnode->dn_dbuf 224 * only accessed by sync thread ??? 225 * (NULL when evicted) 226 * May change from NULL to non-NULL under the protection of db_mtx 227 * (see dbuf_check_blkptr()) 228 */ 229 struct dmu_buf_impl *db_parent; 230 231 /* 232 * link for hash table of all dmu_buf_impl_t's 233 */ 234 struct dmu_buf_impl *db_hash_next; 235 236 /* 237 * Our link on the owner dnodes's dn_dbufs list. 238 * Protected by its dn_dbufs_mtx. Should be on the same cache line 239 * as db_level and db_blkid for the best avl_add() performance. 240 */ 241 avl_node_t db_link; 242 243 /* our block number */ 244 uint64_t db_blkid; 245 246 /* 247 * Pointer to the blkptr_t which points to us. May be NULL if we 248 * don't have one yet. (NULL when evicted) 249 */ 250 blkptr_t *db_blkptr; 251 252 /* 253 * Our indirection level. Data buffers have db_level==0. 254 * Indirect buffers which point to data buffers have 255 * db_level==1. etc. Buffers which contain dnodes have 256 * db_level==0, since the dnodes are stored in a file. 257 */ 258 uint8_t db_level; 259 260 /* 261 * Protects db_buf's contents if they contain an indirect block or data 262 * block of the meta-dnode. We use this lock to protect the structure of 263 * the block tree. This means that when modifying this dbuf's data, we 264 * grab its rwlock. When modifying its parent's data (including the 265 * blkptr to this dbuf), we grab the parent's rwlock. The lock ordering 266 * for this lock is: 267 * 1) dn_struct_rwlock 268 * 2) db_rwlock 269 * We don't currently grab multiple dbufs' db_rwlocks at once. 270 */ 271 krwlock_t db_rwlock; 272 273 /* buffer holding our data */ 274 arc_buf_t *db_buf; 275 276 /* db_mtx protects the members below */ 277 kmutex_t db_mtx; 278 279 /* 280 * Current state of the buffer 281 */ 282 dbuf_states_t db_state; 283 284 /* 285 * Refcount accessed by dmu_buf_{hold,rele}. 286 * If nonzero, the buffer can't be destroyed. 287 * Protected by db_mtx. 288 */ 289 zfs_refcount_t db_holds; 290 291 kcondvar_t db_changed; 292 dbuf_dirty_record_t *db_data_pending; 293 294 /* List of dirty records for the buffer sorted newest to oldest. */ 295 list_t db_dirty_records; 296 297 /* Link in dbuf_cache or dbuf_metadata_cache */ 298 multilist_node_t db_cache_link; 299 300 /* Tells us which dbuf cache this dbuf is in, if any */ 301 dbuf_cached_state_t db_caching_status; 302 303 uint64_t db_hash; 304 305 /* Data which is unique to data (leaf) blocks: */ 306 307 /* User callback information. */ 308 dmu_buf_user_t *db_user; 309 310 /* 311 * Evict user data as soon as the dirty and reference 312 * counts are equal. 313 */ 314 uint8_t db_user_immediate_evict; 315 316 /* 317 * This block was freed while a read or write was 318 * active. 319 */ 320 uint8_t db_freed_in_flight; 321 322 /* 323 * dnode_evict_dbufs() or dnode_evict_bonus() tried to 324 * evict this dbuf, but couldn't due to outstanding 325 * references. Evict once the refcount drops to 0. 326 */ 327 uint8_t db_pending_evict; 328 329 uint8_t db_dirtycnt; 330 331 /* The buffer was partially read. More reads may follow. */ 332 uint8_t db_partial_read; 333} dmu_buf_impl_t; 334 335#define DBUF_HASH_MUTEX(h, idx) \ 336 (&(h)->hash_mutexes[(idx) & ((h)->hash_mutex_mask)]) 337 338typedef struct dbuf_hash_table { 339 uint64_t hash_table_mask; 340 uint64_t hash_mutex_mask; 341 dmu_buf_impl_t **hash_table; 342 kmutex_t *hash_mutexes; 343} dbuf_hash_table_t; 344 345typedef void (*dbuf_prefetch_fn)(void *, uint64_t, uint64_t, boolean_t); 346 347uint64_t dbuf_whichblock(const struct dnode *di, const int64_t level, 348 const uint64_t offset); 349 350void dbuf_create_bonus(struct dnode *dn); 351int dbuf_spill_set_blksz(dmu_buf_t *db, uint64_t blksz, dmu_tx_t *tx); 352 353void dbuf_rm_spill(struct dnode *dn, dmu_tx_t *tx); 354 355dmu_buf_impl_t *dbuf_hold(struct dnode *dn, uint64_t blkid, const void *tag); 356dmu_buf_impl_t *dbuf_hold_level(struct dnode *dn, int level, uint64_t blkid, 357 const void *tag); 358int dbuf_hold_impl(struct dnode *dn, uint8_t level, uint64_t blkid, 359 boolean_t fail_sparse, boolean_t fail_uncached, 360 const void *tag, dmu_buf_impl_t **dbp); 361 362int dbuf_prefetch_impl(struct dnode *dn, int64_t level, uint64_t blkid, 363 zio_priority_t prio, arc_flags_t aflags, dbuf_prefetch_fn cb, 364 void *arg); 365int dbuf_prefetch(struct dnode *dn, int64_t level, uint64_t blkid, 366 zio_priority_t prio, arc_flags_t aflags); 367 368void dbuf_add_ref(dmu_buf_impl_t *db, const void *tag); 369boolean_t dbuf_try_add_ref(dmu_buf_t *db, objset_t *os, uint64_t obj, 370 uint64_t blkid, const void *tag); 371uint64_t dbuf_refcount(dmu_buf_impl_t *db); 372 373void dbuf_rele(dmu_buf_impl_t *db, const void *tag); 374void dbuf_rele_and_unlock(dmu_buf_impl_t *db, const void *tag, 375 boolean_t evicting); 376 377dmu_buf_impl_t *dbuf_find(struct objset *os, uint64_t object, uint8_t level, 378 uint64_t blkid, uint64_t *hash_out); 379 380int dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags); 381void dmu_buf_will_clone(dmu_buf_t *db, dmu_tx_t *tx); 382void dmu_buf_will_not_fill(dmu_buf_t *db, dmu_tx_t *tx); 383void dmu_buf_will_fill(dmu_buf_t *db, dmu_tx_t *tx, boolean_t canfail); 384boolean_t dmu_buf_fill_done(dmu_buf_t *db, dmu_tx_t *tx, boolean_t failed); 385void dbuf_assign_arcbuf(dmu_buf_impl_t *db, arc_buf_t *buf, dmu_tx_t *tx); 386dbuf_dirty_record_t *dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx); 387dbuf_dirty_record_t *dbuf_dirty_lightweight(dnode_t *dn, uint64_t blkid, 388 dmu_tx_t *tx); 389boolean_t dbuf_undirty(dmu_buf_impl_t *db, dmu_tx_t *tx); 390arc_buf_t *dbuf_loan_arcbuf(dmu_buf_impl_t *db); 391void dmu_buf_write_embedded(dmu_buf_t *dbuf, void *data, 392 bp_embedded_type_t etype, enum zio_compress comp, 393 int uncompressed_size, int compressed_size, int byteorder, dmu_tx_t *tx); 394 395int dmu_lightweight_write_by_dnode(dnode_t *dn, uint64_t offset, abd_t *abd, 396 const struct zio_prop *zp, zio_flag_t flags, dmu_tx_t *tx); 397 398void dmu_buf_redact(dmu_buf_t *dbuf, dmu_tx_t *tx); 399void dbuf_destroy(dmu_buf_impl_t *db); 400 401void dbuf_unoverride(dbuf_dirty_record_t *dr); 402void dbuf_sync_list(list_t *list, int level, dmu_tx_t *tx); 403void dbuf_release_bp(dmu_buf_impl_t *db); 404db_lock_type_t dmu_buf_lock_parent(dmu_buf_impl_t *db, krw_t rw, 405 const void *tag); 406void dmu_buf_unlock_parent(dmu_buf_impl_t *db, db_lock_type_t type, 407 const void *tag); 408 409void dbuf_free_range(struct dnode *dn, uint64_t start, uint64_t end, 410 struct dmu_tx *); 411 412void dbuf_new_size(dmu_buf_impl_t *db, int size, dmu_tx_t *tx); 413 414void dbuf_stats_init(dbuf_hash_table_t *hash); 415void dbuf_stats_destroy(void); 416 417int dbuf_dnode_findbp(dnode_t *dn, uint64_t level, uint64_t blkid, 418 blkptr_t *bp, uint16_t *datablkszsec, uint8_t *indblkshift); 419 420#define DB_DNODE(_db) ((_db)->db_dnode_handle->dnh_dnode) 421#define DB_DNODE_LOCK(_db) ((_db)->db_dnode_handle->dnh_zrlock) 422#define DB_DNODE_ENTER(_db) (zrl_add(&DB_DNODE_LOCK(_db))) 423#define DB_DNODE_EXIT(_db) (zrl_remove(&DB_DNODE_LOCK(_db))) 424#define DB_DNODE_HELD(_db) (!zrl_is_zero(&DB_DNODE_LOCK(_db))) 425 426void dbuf_init(void); 427void dbuf_fini(void); 428 429boolean_t dbuf_is_metadata(dmu_buf_impl_t *db); 430 431static inline dbuf_dirty_record_t * 432dbuf_find_dirty_lte(dmu_buf_impl_t *db, uint64_t txg) 433{ 434 dbuf_dirty_record_t *dr; 435 436 for (dr = list_head(&db->db_dirty_records); 437 dr != NULL && dr->dr_txg > txg; 438 dr = list_next(&db->db_dirty_records, dr)) 439 continue; 440 return (dr); 441} 442 443static inline dbuf_dirty_record_t * 444dbuf_find_dirty_eq(dmu_buf_impl_t *db, uint64_t txg) 445{ 446 dbuf_dirty_record_t *dr; 447 448 dr = dbuf_find_dirty_lte(db, txg); 449 if (dr && dr->dr_txg == txg) 450 return (dr); 451 return (NULL); 452} 453 454#define DBUF_GET_BUFC_TYPE(_db) \ 455 (dbuf_is_metadata(_db) ? ARC_BUFC_METADATA : ARC_BUFC_DATA) 456 457#define DBUF_IS_CACHEABLE(_db) \ 458 ((_db)->db_objset->os_primary_cache == ZFS_CACHE_ALL || \ 459 (dbuf_is_metadata(_db) && \ 460 ((_db)->db_objset->os_primary_cache == ZFS_CACHE_METADATA))) 461 462boolean_t dbuf_is_l2cacheable(dmu_buf_impl_t *db); 463 464#ifdef ZFS_DEBUG 465 466/* 467 * There should be a ## between the string literal and fmt, to make it 468 * clear that we're joining two strings together, but gcc does not 469 * support that preprocessor token. 470 */ 471#define dprintf_dbuf(dbuf, fmt, ...) do { \ 472 if (zfs_flags & ZFS_DEBUG_DPRINTF) { \ 473 char __db_buf[32]; \ 474 uint64_t __db_obj = (dbuf)->db.db_object; \ 475 if (__db_obj == DMU_META_DNODE_OBJECT) \ 476 (void) strlcpy(__db_buf, "mdn", sizeof (__db_buf)); \ 477 else \ 478 (void) snprintf(__db_buf, sizeof (__db_buf), "%lld", \ 479 (u_longlong_t)__db_obj); \ 480 dprintf_ds((dbuf)->db_objset->os_dsl_dataset, \ 481 "obj=%s lvl=%u blkid=%lld " fmt, \ 482 __db_buf, (dbuf)->db_level, \ 483 (u_longlong_t)(dbuf)->db_blkid, __VA_ARGS__); \ 484 } \ 485} while (0) 486 487#define dprintf_dbuf_bp(db, bp, fmt, ...) do { \ 488 if (zfs_flags & ZFS_DEBUG_DPRINTF) { \ 489 char *__blkbuf = kmem_alloc(BP_SPRINTF_LEN, KM_SLEEP); \ 490 snprintf_blkptr(__blkbuf, BP_SPRINTF_LEN, bp); \ 491 dprintf_dbuf(db, fmt " %s\n", __VA_ARGS__, __blkbuf); \ 492 kmem_free(__blkbuf, BP_SPRINTF_LEN); \ 493 } \ 494} while (0) 495 496#define DBUF_VERIFY(db) dbuf_verify(db) 497 498#else 499 500#define dprintf_dbuf(db, fmt, ...) 501#define dprintf_dbuf_bp(db, bp, fmt, ...) 502#define DBUF_VERIFY(db) 503 504#endif 505 506 507#ifdef __cplusplus 508} 509#endif 510 511#endif /* _SYS_DBUF_H */ 512