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