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