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) 2012, 2018 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/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 59 /* 60 * The simplified state transition diagram for dbufs looks like: 61 * 62 * +----> READ ----+ 63 * | | 64 * | V 65 * (alloc)-->UNCACHED CACHED-->EVICTING-->(free) 66 * | ^ ^ 67 * | | | 68 * +----> FILL ----+ | 69 * | | 70 * | | 71 * +--------> NOFILL -------+ 72 * 73 * DB_SEARCH is an invalid state for a dbuf. It is used by dbuf_free_range 74 * to find all dbufs in a range of a dnode and must be less than any other 75 * dbuf_states_t (see comment on dn_dbufs in dnode.h). 76 */ 77 typedef enum dbuf_states { 78 DB_SEARCH = -1, 79 DB_UNCACHED, 80 DB_FILL, 81 DB_NOFILL, 82 DB_READ, 83 DB_CACHED, 84 DB_EVICTING 85 } dbuf_states_t; 86 87 typedef enum dbuf_cached_state { 88 DB_NO_CACHE = -1, 89 DB_DBUF_CACHE, 90 DB_DBUF_METADATA_CACHE, 91 DB_CACHE_MAX 92 } dbuf_cached_state_t; 93 94 struct dnode; 95 struct dmu_tx; 96 97 /* 98 * level = 0 means the user data 99 * level = 1 means the single indirect block 100 * etc. 101 */ 102 103 struct dmu_buf_impl; 104 105 typedef enum override_states { 106 DR_NOT_OVERRIDDEN, 107 DR_IN_DMU_SYNC, 108 DR_OVERRIDDEN 109 } override_states_t; 110 111 typedef enum db_lock_type { 112 DLT_NONE, 113 DLT_PARENT, 114 DLT_OBJSET 115 } db_lock_type_t; 116 117 typedef struct dbuf_dirty_record { 118 /* link on our parents dirty list */ 119 list_node_t dr_dirty_node; 120 121 /* transaction group this data will sync in */ 122 uint64_t dr_txg; 123 124 /* zio of outstanding write IO */ 125 zio_t *dr_zio; 126 127 /* pointer back to our dbuf */ 128 struct dmu_buf_impl *dr_dbuf; 129 130 /* pointer to next dirty record */ 131 struct dbuf_dirty_record *dr_next; 132 133 /* pointer to parent dirty record */ 134 struct dbuf_dirty_record *dr_parent; 135 136 /* How much space was changed to dsl_pool_dirty_space() for this? */ 137 unsigned int dr_accounted; 138 139 /* A copy of the bp that points to us */ 140 blkptr_t dr_bp_copy; 141 142 union dirty_types { 143 struct dirty_indirect { 144 145 /* protect access to list */ 146 kmutex_t dr_mtx; 147 148 /* Our list of dirty children */ 149 list_t dr_children; 150 } di; 151 struct dirty_leaf { 152 153 /* 154 * dr_data is set when we dirty the buffer 155 * so that we can retain the pointer even if it 156 * gets COW'd in a subsequent transaction group. 157 */ 158 arc_buf_t *dr_data; 159 blkptr_t dr_overridden_by; 160 override_states_t dr_override_state; 161 uint8_t dr_copies; 162 boolean_t dr_nopwrite; 163 boolean_t dr_has_raw_params; 164 165 /* 166 * If dr_has_raw_params is set, the following crypt 167 * params will be set on the BP that's written. 168 */ 169 boolean_t dr_byteorder; 170 uint8_t dr_salt[ZIO_DATA_SALT_LEN]; 171 uint8_t dr_iv[ZIO_DATA_IV_LEN]; 172 uint8_t dr_mac[ZIO_DATA_MAC_LEN]; 173 } dl; 174 } dt; 175 } dbuf_dirty_record_t; 176 177 typedef struct dmu_buf_impl { 178 /* 179 * The following members are immutable, with the exception of 180 * db.db_data, which is protected by db_mtx. 181 */ 182 183 /* the publicly visible structure */ 184 dmu_buf_t db; 185 186 /* the objset we belong to */ 187 struct objset *db_objset; 188 189 /* 190 * handle to safely access the dnode we belong to (NULL when evicted) 191 */ 192 struct dnode_handle *db_dnode_handle; 193 194 /* 195 * our parent buffer; if the dnode points to us directly, 196 * db_parent == db_dnode_handle->dnh_dnode->dn_dbuf 197 * only accessed by sync thread ??? 198 * (NULL when evicted) 199 * May change from NULL to non-NULL under the protection of db_mtx 200 * (see dbuf_check_blkptr()) 201 */ 202 struct dmu_buf_impl *db_parent; 203 204 /* 205 * link for hash table of all dmu_buf_impl_t's 206 */ 207 struct dmu_buf_impl *db_hash_next; 208 209 /* our block number */ 210 uint64_t db_blkid; 211 212 /* 213 * Pointer to the blkptr_t which points to us. May be NULL if we 214 * don't have one yet. (NULL when evicted) 215 */ 216 blkptr_t *db_blkptr; 217 218 /* 219 * Our indirection level. Data buffers have db_level==0. 220 * Indirect buffers which point to data buffers have 221 * db_level==1. etc. Buffers which contain dnodes have 222 * db_level==0, since the dnodes are stored in a file. 223 */ 224 uint8_t db_level; 225 226 /* 227 * Protects db_buf's contents if they contain an indirect block or data 228 * block of the meta-dnode. We use this lock to protect the structure of 229 * the block tree. This means that when modifying this dbuf's data, we 230 * grab its rwlock. When modifying its parent's data (including the 231 * blkptr to this dbuf), we grab the parent's rwlock. The lock ordering 232 * for this lock is: 233 * 1) dn_struct_rwlock 234 * 2) db_rwlock 235 * We don't currently grab multiple dbufs' db_rwlocks at once. 236 */ 237 krwlock_t db_rwlock; 238 239 /* buffer holding our data */ 240 arc_buf_t *db_buf; 241 242 /* db_mtx protects the members below */ 243 kmutex_t db_mtx; 244 245 /* 246 * Current state of the buffer 247 */ 248 dbuf_states_t db_state; 249 250 /* 251 * Refcount accessed by dmu_buf_{hold,rele}. 252 * If nonzero, the buffer can't be destroyed. 253 * Protected by db_mtx. 254 */ 255 zfs_refcount_t db_holds; 256 257 kcondvar_t db_changed; 258 dbuf_dirty_record_t *db_data_pending; 259 260 /* pointer to most recent dirty record for this buffer */ 261 dbuf_dirty_record_t *db_last_dirty; 262 263 /* 264 * Our link on the owner dnodes's dn_dbufs list. 265 * Protected by its dn_dbufs_mtx. 266 */ 267 avl_node_t db_link; 268 269 /* Link in dbuf_cache or dbuf_metadata_cache */ 270 multilist_node_t db_cache_link; 271 272 /* Tells us which dbuf cache this dbuf is in, if any */ 273 dbuf_cached_state_t db_caching_status; 274 275 /* Data which is unique to data (leaf) blocks: */ 276 277 /* User callback information. */ 278 dmu_buf_user_t *db_user; 279 280 /* 281 * Evict user data as soon as the dirty and reference 282 * counts are equal. 283 */ 284 uint8_t db_user_immediate_evict; 285 286 /* 287 * This block was freed while a read or write was 288 * active. 289 */ 290 uint8_t db_freed_in_flight; 291 292 /* 293 * dnode_evict_dbufs() or dnode_evict_bonus() tried to 294 * evict this dbuf, but couldn't due to outstanding 295 * references. Evict once the refcount drops to 0. 296 */ 297 uint8_t db_pending_evict; 298 299 uint8_t db_dirtycnt; 300 } dmu_buf_impl_t; 301 302 /* Note: the dbuf hash table is exposed only for the mdb module */ 303 #define DBUF_MUTEXES 256 304 #define DBUF_HASH_MUTEX(h, idx) (&(h)->hash_mutexes[(idx) & (DBUF_MUTEXES-1)]) 305 typedef struct dbuf_hash_table { 306 uint64_t hash_table_mask; 307 dmu_buf_impl_t **hash_table; 308 kmutex_t hash_mutexes[DBUF_MUTEXES]; 309 } dbuf_hash_table_t; 310 311 uint64_t dbuf_whichblock(struct dnode *di, int64_t level, uint64_t offset); 312 313 dmu_buf_impl_t *dbuf_create_tlib(struct dnode *dn, char *data); 314 void dbuf_create_bonus(struct dnode *dn); 315 int dbuf_spill_set_blksz(dmu_buf_t *db, uint64_t blksz, dmu_tx_t *tx); 316 void dbuf_spill_hold(struct dnode *dn, dmu_buf_impl_t **dbp, void *tag); 317 318 void dbuf_rm_spill(struct dnode *dn, dmu_tx_t *tx); 319 320 dmu_buf_impl_t *dbuf_hold(struct dnode *dn, uint64_t blkid, void *tag); 321 dmu_buf_impl_t *dbuf_hold_level(struct dnode *dn, int level, uint64_t blkid, 322 void *tag); 323 int dbuf_hold_impl(struct dnode *dn, uint8_t level, uint64_t blkid, 324 boolean_t fail_sparse, boolean_t fail_uncached, 325 void *tag, dmu_buf_impl_t **dbp); 326 327 void dbuf_prefetch(struct dnode *dn, int64_t level, uint64_t blkid, 328 zio_priority_t prio, arc_flags_t aflags); 329 330 void dbuf_add_ref(dmu_buf_impl_t *db, void *tag); 331 boolean_t dbuf_try_add_ref(dmu_buf_t *db, objset_t *os, uint64_t obj, 332 uint64_t blkid, void *tag); 333 uint64_t dbuf_refcount(dmu_buf_impl_t *db); 334 335 void dbuf_rele(dmu_buf_impl_t *db, void *tag); 336 void dbuf_rele_and_unlock(dmu_buf_impl_t *db, void *tag, boolean_t evicting); 337 338 dmu_buf_impl_t *dbuf_find(struct objset *os, uint64_t object, uint8_t level, 339 uint64_t blkid); 340 341 int dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags); 342 void dmu_buf_will_not_fill(dmu_buf_t *db, dmu_tx_t *tx); 343 void dmu_buf_will_fill(dmu_buf_t *db, dmu_tx_t *tx); 344 void dmu_buf_fill_done(dmu_buf_t *db, dmu_tx_t *tx); 345 void dbuf_assign_arcbuf(dmu_buf_impl_t *db, arc_buf_t *buf, dmu_tx_t *tx); 346 dbuf_dirty_record_t *dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx); 347 arc_buf_t *dbuf_loan_arcbuf(dmu_buf_impl_t *db); 348 void dmu_buf_write_embedded(dmu_buf_t *dbuf, void *data, 349 bp_embedded_type_t etype, enum zio_compress comp, 350 int uncompressed_size, int compressed_size, int byteorder, dmu_tx_t *tx); 351 352 void dbuf_destroy(dmu_buf_impl_t *db); 353 354 void dbuf_setdirty(dmu_buf_impl_t *db, dmu_tx_t *tx); 355 void dbuf_unoverride(dbuf_dirty_record_t *dr); 356 void dbuf_sync_list(list_t *list, int level, dmu_tx_t *tx); 357 void dbuf_release_bp(dmu_buf_impl_t *db); 358 db_lock_type_t dmu_buf_lock_parent(dmu_buf_impl_t *db, krw_t rw, void *tag); 359 void dmu_buf_unlock_parent(dmu_buf_impl_t *db, db_lock_type_t type, void *tag); 360 361 boolean_t dbuf_can_remap(const dmu_buf_impl_t *buf); 362 363 void dbuf_free_range(struct dnode *dn, uint64_t start, uint64_t end, 364 struct dmu_tx *); 365 366 void dbuf_new_size(dmu_buf_impl_t *db, int size, dmu_tx_t *tx); 367 368 #define DB_DNODE(_db) ((_db)->db_dnode_handle->dnh_dnode) 369 #define DB_DNODE_LOCK(_db) ((_db)->db_dnode_handle->dnh_zrlock) 370 #define DB_DNODE_ENTER(_db) (zrl_add(&DB_DNODE_LOCK(_db))) 371 #define DB_DNODE_EXIT(_db) (zrl_remove(&DB_DNODE_LOCK(_db))) 372 #define DB_DNODE_HELD(_db) (!zrl_is_zero(&DB_DNODE_LOCK(_db))) 373 374 void dbuf_init(void); 375 void dbuf_fini(void); 376 377 boolean_t dbuf_is_metadata(dmu_buf_impl_t *db); 378 379 #define DBUF_GET_BUFC_TYPE(_db) \ 380 (dbuf_is_metadata(_db) ? ARC_BUFC_METADATA : ARC_BUFC_DATA) 381 382 #define DBUF_IS_CACHEABLE(_db) \ 383 ((_db)->db_objset->os_primary_cache == ZFS_CACHE_ALL || \ 384 (dbuf_is_metadata(_db) && \ 385 ((_db)->db_objset->os_primary_cache == ZFS_CACHE_METADATA))) 386 387 #define DBUF_IS_L2CACHEABLE(_db) \ 388 ((_db)->db_objset->os_secondary_cache == ZFS_CACHE_ALL || \ 389 (dbuf_is_metadata(_db) && \ 390 ((_db)->db_objset->os_secondary_cache == ZFS_CACHE_METADATA))) 391 392 #define DNODE_LEVEL_IS_L2CACHEABLE(_dn, _level) \ 393 ((_dn)->dn_objset->os_secondary_cache == ZFS_CACHE_ALL || \ 394 (((_level) > 0 || \ 395 DMU_OT_IS_METADATA((_dn)->dn_handle->dnh_dnode->dn_type)) && \ 396 ((_dn)->dn_objset->os_secondary_cache == ZFS_CACHE_METADATA))) 397 398 #ifdef ZFS_DEBUG 399 400 /* 401 * There should be a ## between the string literal and fmt, to make it 402 * clear that we're joining two strings together, but gcc does not 403 * support that preprocessor token. 404 */ 405 #define dprintf_dbuf(dbuf, fmt, ...) do { \ 406 if (zfs_flags & ZFS_DEBUG_DPRINTF) { \ 407 char __db_buf[32]; \ 408 uint64_t __db_obj = (dbuf)->db.db_object; \ 409 if (__db_obj == DMU_META_DNODE_OBJECT) \ 410 (void) strcpy(__db_buf, "mdn"); \ 411 else \ 412 (void) snprintf(__db_buf, sizeof (__db_buf), "%lld", \ 413 (u_longlong_t)__db_obj); \ 414 dprintf_ds((dbuf)->db_objset->os_dsl_dataset, \ 415 "obj=%s lvl=%u blkid=%lld " fmt, \ 416 __db_buf, (dbuf)->db_level, \ 417 (u_longlong_t)(dbuf)->db_blkid, __VA_ARGS__); \ 418 } \ 419 _NOTE(CONSTCOND) } while (0) 420 421 #define dprintf_dbuf_bp(db, bp, fmt, ...) do { \ 422 if (zfs_flags & ZFS_DEBUG_DPRINTF) { \ 423 char *__blkbuf = kmem_alloc(BP_SPRINTF_LEN, KM_SLEEP); \ 424 snprintf_blkptr(__blkbuf, BP_SPRINTF_LEN, bp); \ 425 dprintf_dbuf(db, fmt " %s\n", __VA_ARGS__, __blkbuf); \ 426 kmem_free(__blkbuf, BP_SPRINTF_LEN); \ 427 } \ 428 _NOTE(CONSTCOND) } while (0) 429 430 #define DBUF_VERIFY(db) dbuf_verify(db) 431 432 #else 433 434 #define dprintf_dbuf(db, fmt, ...) 435 #define dprintf_dbuf_bp(db, bp, fmt, ...) 436 #define DBUF_VERIFY(db) 437 438 #endif 439 440 441 #ifdef __cplusplus 442 } 443 #endif 444 445 #endif /* _SYS_DBUF_H */ 446