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 /* 23 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 24 * Copyright (c) 2011, 2014 by Delphix. All rights reserved. 25 * Copyright 2011 Nexenta Systems, Inc. All rights reserved. 26 * Copyright (c) 2012, Joyent, Inc. All rights reserved. 27 * Copyright 2013 DEY Storage Systems, Inc. 28 * Copyright 2014 HybridCluster. All rights reserved. 29 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. 30 * Copyright 2013 Saso Kiselkov. All rights reserved. 31 */ 32 33 /* Portions Copyright 2010 Robert Milkowski */ 34 35 #ifndef _SYS_DMU_H 36 #define _SYS_DMU_H 37 38 /* 39 * This file describes the interface that the DMU provides for its 40 * consumers. 41 * 42 * The DMU also interacts with the SPA. That interface is described in 43 * dmu_spa.h. 44 */ 45 46 #include <sys/zfs_context.h> 47 #include <sys/inttypes.h> 48 #include <sys/cred.h> 49 #include <sys/fs/zfs.h> 50 #include <sys/zio_priority.h> 51 52 #ifdef __cplusplus 53 extern "C" { 54 #endif 55 56 struct uio; 57 struct xuio; 58 struct page; 59 struct vnode; 60 struct spa; 61 struct zilog; 62 struct zio; 63 struct blkptr; 64 struct zap_cursor; 65 struct dsl_dataset; 66 struct dsl_pool; 67 struct dnode; 68 struct drr_begin; 69 struct drr_end; 70 struct zbookmark_phys; 71 struct spa; 72 struct nvlist; 73 struct arc_buf; 74 struct zio_prop; 75 struct sa_handle; 76 77 typedef struct objset objset_t; 78 typedef struct dmu_tx dmu_tx_t; 79 typedef struct dsl_dir dsl_dir_t; 80 81 typedef enum dmu_object_byteswap { 82 DMU_BSWAP_UINT8, 83 DMU_BSWAP_UINT16, 84 DMU_BSWAP_UINT32, 85 DMU_BSWAP_UINT64, 86 DMU_BSWAP_ZAP, 87 DMU_BSWAP_DNODE, 88 DMU_BSWAP_OBJSET, 89 DMU_BSWAP_ZNODE, 90 DMU_BSWAP_OLDACL, 91 DMU_BSWAP_ACL, 92 /* 93 * Allocating a new byteswap type number makes the on-disk format 94 * incompatible with any other format that uses the same number. 95 * 96 * Data can usually be structured to work with one of the 97 * DMU_BSWAP_UINT* or DMU_BSWAP_ZAP types. 98 */ 99 DMU_BSWAP_NUMFUNCS 100 } dmu_object_byteswap_t; 101 102 #define DMU_OT_NEWTYPE 0x80 103 #define DMU_OT_METADATA 0x40 104 #define DMU_OT_BYTESWAP_MASK 0x3f 105 106 /* 107 * Defines a uint8_t object type. Object types specify if the data 108 * in the object is metadata (boolean) and how to byteswap the data 109 * (dmu_object_byteswap_t). 110 */ 111 #define DMU_OT(byteswap, metadata) \ 112 (DMU_OT_NEWTYPE | \ 113 ((metadata) ? DMU_OT_METADATA : 0) | \ 114 ((byteswap) & DMU_OT_BYTESWAP_MASK)) 115 116 #define DMU_OT_IS_VALID(ot) (((ot) & DMU_OT_NEWTYPE) ? \ 117 ((ot) & DMU_OT_BYTESWAP_MASK) < DMU_BSWAP_NUMFUNCS : \ 118 (ot) < DMU_OT_NUMTYPES) 119 120 #define DMU_OT_IS_METADATA(ot) (((ot) & DMU_OT_NEWTYPE) ? \ 121 ((ot) & DMU_OT_METADATA) : \ 122 dmu_ot[(ot)].ot_metadata) 123 124 /* 125 * These object types use bp_fill != 1 for their L0 bp's. Therefore they can't 126 * have their data embedded (i.e. use a BP_IS_EMBEDDED() bp), because bp_fill 127 * is repurposed for embedded BPs. 128 */ 129 #define DMU_OT_HAS_FILL(ot) \ 130 ((ot) == DMU_OT_DNODE || (ot) == DMU_OT_OBJSET) 131 132 #define DMU_OT_BYTESWAP(ot) (((ot) & DMU_OT_NEWTYPE) ? \ 133 ((ot) & DMU_OT_BYTESWAP_MASK) : \ 134 dmu_ot[(ot)].ot_byteswap) 135 136 typedef enum dmu_object_type { 137 DMU_OT_NONE, 138 /* general: */ 139 DMU_OT_OBJECT_DIRECTORY, /* ZAP */ 140 DMU_OT_OBJECT_ARRAY, /* UINT64 */ 141 DMU_OT_PACKED_NVLIST, /* UINT8 (XDR by nvlist_pack/unpack) */ 142 DMU_OT_PACKED_NVLIST_SIZE, /* UINT64 */ 143 DMU_OT_BPOBJ, /* UINT64 */ 144 DMU_OT_BPOBJ_HDR, /* UINT64 */ 145 /* spa: */ 146 DMU_OT_SPACE_MAP_HEADER, /* UINT64 */ 147 DMU_OT_SPACE_MAP, /* UINT64 */ 148 /* zil: */ 149 DMU_OT_INTENT_LOG, /* UINT64 */ 150 /* dmu: */ 151 DMU_OT_DNODE, /* DNODE */ 152 DMU_OT_OBJSET, /* OBJSET */ 153 /* dsl: */ 154 DMU_OT_DSL_DIR, /* UINT64 */ 155 DMU_OT_DSL_DIR_CHILD_MAP, /* ZAP */ 156 DMU_OT_DSL_DS_SNAP_MAP, /* ZAP */ 157 DMU_OT_DSL_PROPS, /* ZAP */ 158 DMU_OT_DSL_DATASET, /* UINT64 */ 159 /* zpl: */ 160 DMU_OT_ZNODE, /* ZNODE */ 161 DMU_OT_OLDACL, /* Old ACL */ 162 DMU_OT_PLAIN_FILE_CONTENTS, /* UINT8 */ 163 DMU_OT_DIRECTORY_CONTENTS, /* ZAP */ 164 DMU_OT_MASTER_NODE, /* ZAP */ 165 DMU_OT_UNLINKED_SET, /* ZAP */ 166 /* zvol: */ 167 DMU_OT_ZVOL, /* UINT8 */ 168 DMU_OT_ZVOL_PROP, /* ZAP */ 169 /* other; for testing only! */ 170 DMU_OT_PLAIN_OTHER, /* UINT8 */ 171 DMU_OT_UINT64_OTHER, /* UINT64 */ 172 DMU_OT_ZAP_OTHER, /* ZAP */ 173 /* new object types: */ 174 DMU_OT_ERROR_LOG, /* ZAP */ 175 DMU_OT_SPA_HISTORY, /* UINT8 */ 176 DMU_OT_SPA_HISTORY_OFFSETS, /* spa_his_phys_t */ 177 DMU_OT_POOL_PROPS, /* ZAP */ 178 DMU_OT_DSL_PERMS, /* ZAP */ 179 DMU_OT_ACL, /* ACL */ 180 DMU_OT_SYSACL, /* SYSACL */ 181 DMU_OT_FUID, /* FUID table (Packed NVLIST UINT8) */ 182 DMU_OT_FUID_SIZE, /* FUID table size UINT64 */ 183 DMU_OT_NEXT_CLONES, /* ZAP */ 184 DMU_OT_SCAN_QUEUE, /* ZAP */ 185 DMU_OT_USERGROUP_USED, /* ZAP */ 186 DMU_OT_USERGROUP_QUOTA, /* ZAP */ 187 DMU_OT_USERREFS, /* ZAP */ 188 DMU_OT_DDT_ZAP, /* ZAP */ 189 DMU_OT_DDT_STATS, /* ZAP */ 190 DMU_OT_SA, /* System attr */ 191 DMU_OT_SA_MASTER_NODE, /* ZAP */ 192 DMU_OT_SA_ATTR_REGISTRATION, /* ZAP */ 193 DMU_OT_SA_ATTR_LAYOUTS, /* ZAP */ 194 DMU_OT_SCAN_XLATE, /* ZAP */ 195 DMU_OT_DEDUP, /* fake dedup BP from ddt_bp_create() */ 196 DMU_OT_DEADLIST, /* ZAP */ 197 DMU_OT_DEADLIST_HDR, /* UINT64 */ 198 DMU_OT_DSL_CLONES, /* ZAP */ 199 DMU_OT_BPOBJ_SUBOBJ, /* UINT64 */ 200 /* 201 * Do not allocate new object types here. Doing so makes the on-disk 202 * format incompatible with any other format that uses the same object 203 * type number. 204 * 205 * When creating an object which does not have one of the above types 206 * use the DMU_OTN_* type with the correct byteswap and metadata 207 * values. 208 * 209 * The DMU_OTN_* types do not have entries in the dmu_ot table, 210 * use the DMU_OT_IS_METDATA() and DMU_OT_BYTESWAP() macros instead 211 * of indexing into dmu_ot directly (this works for both DMU_OT_* types 212 * and DMU_OTN_* types). 213 */ 214 DMU_OT_NUMTYPES, 215 216 /* 217 * Names for valid types declared with DMU_OT(). 218 */ 219 DMU_OTN_UINT8_DATA = DMU_OT(DMU_BSWAP_UINT8, B_FALSE), 220 DMU_OTN_UINT8_METADATA = DMU_OT(DMU_BSWAP_UINT8, B_TRUE), 221 DMU_OTN_UINT16_DATA = DMU_OT(DMU_BSWAP_UINT16, B_FALSE), 222 DMU_OTN_UINT16_METADATA = DMU_OT(DMU_BSWAP_UINT16, B_TRUE), 223 DMU_OTN_UINT32_DATA = DMU_OT(DMU_BSWAP_UINT32, B_FALSE), 224 DMU_OTN_UINT32_METADATA = DMU_OT(DMU_BSWAP_UINT32, B_TRUE), 225 DMU_OTN_UINT64_DATA = DMU_OT(DMU_BSWAP_UINT64, B_FALSE), 226 DMU_OTN_UINT64_METADATA = DMU_OT(DMU_BSWAP_UINT64, B_TRUE), 227 DMU_OTN_ZAP_DATA = DMU_OT(DMU_BSWAP_ZAP, B_FALSE), 228 DMU_OTN_ZAP_METADATA = DMU_OT(DMU_BSWAP_ZAP, B_TRUE), 229 } dmu_object_type_t; 230 231 typedef enum txg_how { 232 TXG_WAIT = 1, 233 TXG_NOWAIT, 234 TXG_WAITED, 235 } txg_how_t; 236 237 void byteswap_uint64_array(void *buf, size_t size); 238 void byteswap_uint32_array(void *buf, size_t size); 239 void byteswap_uint16_array(void *buf, size_t size); 240 void byteswap_uint8_array(void *buf, size_t size); 241 void zap_byteswap(void *buf, size_t size); 242 void zfs_oldacl_byteswap(void *buf, size_t size); 243 void zfs_acl_byteswap(void *buf, size_t size); 244 void zfs_znode_byteswap(void *buf, size_t size); 245 246 #define DS_FIND_SNAPSHOTS (1<<0) 247 #define DS_FIND_CHILDREN (1<<1) 248 #define DS_FIND_SERIALIZE (1<<2) 249 250 /* 251 * The maximum number of bytes that can be accessed as part of one 252 * operation, including metadata. 253 */ 254 #define DMU_MAX_ACCESS (32 * 1024 * 1024) /* 32MB */ 255 #define DMU_MAX_DELETEBLKCNT (20480) /* ~5MB of indirect blocks */ 256 257 #define DMU_USERUSED_OBJECT (-1ULL) 258 #define DMU_GROUPUSED_OBJECT (-2ULL) 259 260 /* 261 * artificial blkids for bonus buffer and spill blocks 262 */ 263 #define DMU_BONUS_BLKID (-1ULL) 264 #define DMU_SPILL_BLKID (-2ULL) 265 /* 266 * Public routines to create, destroy, open, and close objsets. 267 */ 268 int dmu_objset_hold(const char *name, void *tag, objset_t **osp); 269 int dmu_objset_own(const char *name, dmu_objset_type_t type, 270 boolean_t readonly, void *tag, objset_t **osp); 271 void dmu_objset_rele(objset_t *os, void *tag); 272 void dmu_objset_disown(objset_t *os, void *tag); 273 int dmu_objset_open_ds(struct dsl_dataset *ds, objset_t **osp); 274 275 void dmu_objset_evict_dbufs(objset_t *os); 276 int dmu_objset_create(const char *name, dmu_objset_type_t type, uint64_t flags, 277 void (*func)(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx), void *arg); 278 int dmu_objset_clone(const char *name, const char *origin); 279 int dsl_destroy_snapshots_nvl(struct nvlist *snaps, boolean_t defer, 280 struct nvlist *errlist); 281 int dmu_objset_snapshot_one(const char *fsname, const char *snapname); 282 int dmu_objset_snapshot_tmp(const char *, const char *, int); 283 int dmu_objset_find(char *name, int func(const char *, void *), void *arg, 284 int flags); 285 void dmu_objset_byteswap(void *buf, size_t size); 286 int dsl_dataset_rename_snapshot(const char *fsname, 287 const char *oldsnapname, const char *newsnapname, boolean_t recursive); 288 289 typedef struct dmu_buf { 290 uint64_t db_object; /* object that this buffer is part of */ 291 uint64_t db_offset; /* byte offset in this object */ 292 uint64_t db_size; /* size of buffer in bytes */ 293 void *db_data; /* data in buffer */ 294 } dmu_buf_t; 295 296 /* 297 * The names of zap entries in the DIRECTORY_OBJECT of the MOS. 298 */ 299 #define DMU_POOL_DIRECTORY_OBJECT 1 300 #define DMU_POOL_CONFIG "config" 301 #define DMU_POOL_FEATURES_FOR_WRITE "features_for_write" 302 #define DMU_POOL_FEATURES_FOR_READ "features_for_read" 303 #define DMU_POOL_FEATURE_DESCRIPTIONS "feature_descriptions" 304 #define DMU_POOL_FEATURE_ENABLED_TXG "feature_enabled_txg" 305 #define DMU_POOL_ROOT_DATASET "root_dataset" 306 #define DMU_POOL_SYNC_BPOBJ "sync_bplist" 307 #define DMU_POOL_ERRLOG_SCRUB "errlog_scrub" 308 #define DMU_POOL_ERRLOG_LAST "errlog_last" 309 #define DMU_POOL_SPARES "spares" 310 #define DMU_POOL_DEFLATE "deflate" 311 #define DMU_POOL_HISTORY "history" 312 #define DMU_POOL_PROPS "pool_props" 313 #define DMU_POOL_L2CACHE "l2cache" 314 #define DMU_POOL_TMP_USERREFS "tmp_userrefs" 315 #define DMU_POOL_DDT "DDT-%s-%s-%s" 316 #define DMU_POOL_DDT_STATS "DDT-statistics" 317 #define DMU_POOL_CREATION_VERSION "creation_version" 318 #define DMU_POOL_SCAN "scan" 319 #define DMU_POOL_FREE_BPOBJ "free_bpobj" 320 #define DMU_POOL_BPTREE_OBJ "bptree_obj" 321 #define DMU_POOL_EMPTY_BPOBJ "empty_bpobj" 322 #define DMU_POOL_CHECKSUM_SALT "org.illumos:checksum_salt" 323 324 /* 325 * Allocate an object from this objset. The range of object numbers 326 * available is (0, DN_MAX_OBJECT). Object 0 is the meta-dnode. 327 * 328 * The transaction must be assigned to a txg. The newly allocated 329 * object will be "held" in the transaction (ie. you can modify the 330 * newly allocated object in this transaction). 331 * 332 * dmu_object_alloc() chooses an object and returns it in *objectp. 333 * 334 * dmu_object_claim() allocates a specific object number. If that 335 * number is already allocated, it fails and returns EEXIST. 336 * 337 * Return 0 on success, or ENOSPC or EEXIST as specified above. 338 */ 339 uint64_t dmu_object_alloc(objset_t *os, dmu_object_type_t ot, 340 int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx); 341 int dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot, 342 int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx); 343 int dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot, 344 int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *txp); 345 346 /* 347 * Free an object from this objset. 348 * 349 * The object's data will be freed as well (ie. you don't need to call 350 * dmu_free(object, 0, -1, tx)). 351 * 352 * The object need not be held in the transaction. 353 * 354 * If there are any holds on this object's buffers (via dmu_buf_hold()), 355 * or tx holds on the object (via dmu_tx_hold_object()), you can not 356 * free it; it fails and returns EBUSY. 357 * 358 * If the object is not allocated, it fails and returns ENOENT. 359 * 360 * Return 0 on success, or EBUSY or ENOENT as specified above. 361 */ 362 int dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx); 363 364 /* 365 * Find the next allocated or free object. 366 * 367 * The objectp parameter is in-out. It will be updated to be the next 368 * object which is allocated. Ignore objects which have not been 369 * modified since txg. 370 * 371 * XXX Can only be called on a objset with no dirty data. 372 * 373 * Returns 0 on success, or ENOENT if there are no more objects. 374 */ 375 int dmu_object_next(objset_t *os, uint64_t *objectp, 376 boolean_t hole, uint64_t txg); 377 378 /* 379 * Set the data blocksize for an object. 380 * 381 * The object cannot have any blocks allcated beyond the first. If 382 * the first block is allocated already, the new size must be greater 383 * than the current block size. If these conditions are not met, 384 * ENOTSUP will be returned. 385 * 386 * Returns 0 on success, or EBUSY if there are any holds on the object 387 * contents, or ENOTSUP as described above. 388 */ 389 int dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size, 390 int ibs, dmu_tx_t *tx); 391 392 /* 393 * Set the checksum property on a dnode. The new checksum algorithm will 394 * apply to all newly written blocks; existing blocks will not be affected. 395 */ 396 void dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum, 397 dmu_tx_t *tx); 398 399 /* 400 * Set the compress property on a dnode. The new compression algorithm will 401 * apply to all newly written blocks; existing blocks will not be affected. 402 */ 403 void dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress, 404 dmu_tx_t *tx); 405 406 void 407 dmu_write_embedded(objset_t *os, uint64_t object, uint64_t offset, 408 void *data, uint8_t etype, uint8_t comp, int uncompressed_size, 409 int compressed_size, int byteorder, dmu_tx_t *tx); 410 411 /* 412 * Decide how to write a block: checksum, compression, number of copies, etc. 413 */ 414 #define WP_NOFILL 0x1 415 #define WP_DMU_SYNC 0x2 416 #define WP_SPILL 0x4 417 418 void dmu_write_policy(objset_t *os, struct dnode *dn, int level, int wp, 419 struct zio_prop *zp); 420 /* 421 * The bonus data is accessed more or less like a regular buffer. 422 * You must dmu_bonus_hold() to get the buffer, which will give you a 423 * dmu_buf_t with db_offset==-1ULL, and db_size = the size of the bonus 424 * data. As with any normal buffer, you must call dmu_buf_read() to 425 * read db_data, dmu_buf_will_dirty() before modifying it, and the 426 * object must be held in an assigned transaction before calling 427 * dmu_buf_will_dirty. You may use dmu_buf_set_user() on the bonus 428 * buffer as well. You must release your hold with dmu_buf_rele(). 429 * 430 * Returns ENOENT, EIO, or 0. 431 */ 432 int dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **); 433 int dmu_bonus_max(void); 434 int dmu_set_bonus(dmu_buf_t *, int, dmu_tx_t *); 435 int dmu_set_bonustype(dmu_buf_t *, dmu_object_type_t, dmu_tx_t *); 436 dmu_object_type_t dmu_get_bonustype(dmu_buf_t *); 437 int dmu_rm_spill(objset_t *, uint64_t, dmu_tx_t *); 438 439 /* 440 * Special spill buffer support used by "SA" framework 441 */ 442 443 int dmu_spill_hold_by_bonus(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp); 444 int dmu_spill_hold_by_dnode(struct dnode *dn, uint32_t flags, 445 void *tag, dmu_buf_t **dbp); 446 int dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp); 447 448 /* 449 * Obtain the DMU buffer from the specified object which contains the 450 * specified offset. dmu_buf_hold() puts a "hold" on the buffer, so 451 * that it will remain in memory. You must release the hold with 452 * dmu_buf_rele(). You musn't access the dmu_buf_t after releasing your 453 * hold. You must have a hold on any dmu_buf_t* you pass to the DMU. 454 * 455 * You must call dmu_buf_read, dmu_buf_will_dirty, or dmu_buf_will_fill 456 * on the returned buffer before reading or writing the buffer's 457 * db_data. The comments for those routines describe what particular 458 * operations are valid after calling them. 459 * 460 * The object number must be a valid, allocated object number. 461 */ 462 int dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset, 463 void *tag, dmu_buf_t **, int flags); 464 465 /* 466 * Add a reference to a dmu buffer that has already been held via 467 * dmu_buf_hold() in the current context. 468 */ 469 void dmu_buf_add_ref(dmu_buf_t *db, void* tag); 470 471 /* 472 * Attempt to add a reference to a dmu buffer that is in an unknown state, 473 * using a pointer that may have been invalidated by eviction processing. 474 * The request will succeed if the passed in dbuf still represents the 475 * same os/object/blkid, is ineligible for eviction, and has at least 476 * one hold by a user other than the syncer. 477 */ 478 boolean_t dmu_buf_try_add_ref(dmu_buf_t *, objset_t *os, uint64_t object, 479 uint64_t blkid, void *tag); 480 481 void dmu_buf_rele(dmu_buf_t *db, void *tag); 482 uint64_t dmu_buf_refcount(dmu_buf_t *db); 483 484 /* 485 * dmu_buf_hold_array holds the DMU buffers which contain all bytes in a 486 * range of an object. A pointer to an array of dmu_buf_t*'s is 487 * returned (in *dbpp). 488 * 489 * dmu_buf_rele_array releases the hold on an array of dmu_buf_t*'s, and 490 * frees the array. The hold on the array of buffers MUST be released 491 * with dmu_buf_rele_array. You can NOT release the hold on each buffer 492 * individually with dmu_buf_rele. 493 */ 494 int dmu_buf_hold_array_by_bonus(dmu_buf_t *db, uint64_t offset, 495 uint64_t length, boolean_t read, void *tag, 496 int *numbufsp, dmu_buf_t ***dbpp); 497 void dmu_buf_rele_array(dmu_buf_t **, int numbufs, void *tag); 498 499 typedef void dmu_buf_evict_func_t(void *user_ptr); 500 501 /* 502 * A DMU buffer user object may be associated with a dbuf for the 503 * duration of its lifetime. This allows the user of a dbuf (client) 504 * to attach private data to a dbuf (e.g. in-core only data such as a 505 * dnode_children_t, zap_t, or zap_leaf_t) and be optionally notified 506 * when that dbuf has been evicted. Clients typically respond to the 507 * eviction notification by freeing their private data, thus ensuring 508 * the same lifetime for both dbuf and private data. 509 * 510 * The mapping from a dmu_buf_user_t to any client private data is the 511 * client's responsibility. All current consumers of the API with private 512 * data embed a dmu_buf_user_t as the first member of the structure for 513 * their private data. This allows conversions between the two types 514 * with a simple cast. Since the DMU buf user API never needs access 515 * to the private data, other strategies can be employed if necessary 516 * or convenient for the client (e.g. using container_of() to do the 517 * conversion for private data that cannot have the dmu_buf_user_t as 518 * its first member). 519 * 520 * Eviction callbacks are executed without the dbuf mutex held or any 521 * other type of mechanism to guarantee that the dbuf is still available. 522 * For this reason, users must assume the dbuf has already been freed 523 * and not reference the dbuf from the callback context. 524 * 525 * Users requesting "immediate eviction" are notified as soon as the dbuf 526 * is only referenced by dirty records (dirties == holds). Otherwise the 527 * notification occurs after eviction processing for the dbuf begins. 528 */ 529 typedef struct dmu_buf_user { 530 /* 531 * Asynchronous user eviction callback state. 532 */ 533 taskq_ent_t dbu_tqent; 534 535 /* This instance's eviction function pointer. */ 536 dmu_buf_evict_func_t *dbu_evict_func; 537 #ifdef ZFS_DEBUG 538 /* 539 * Pointer to user's dbuf pointer. NULL for clients that do 540 * not associate a dbuf with their user data. 541 * 542 * The dbuf pointer is cleared upon eviction so as to catch 543 * use-after-evict bugs in clients. 544 */ 545 dmu_buf_t **dbu_clear_on_evict_dbufp; 546 #endif 547 } dmu_buf_user_t; 548 549 /* 550 * Initialize the given dmu_buf_user_t instance with the eviction function 551 * evict_func, to be called when the user is evicted. 552 * 553 * NOTE: This function should only be called once on a given dmu_buf_user_t. 554 * To allow enforcement of this, dbu must already be zeroed on entry. 555 */ 556 #ifdef __lint 557 /* Very ugly, but it beats issuing suppression directives in many Makefiles. */ 558 extern void 559 dmu_buf_init_user(dmu_buf_user_t *dbu, dmu_buf_evict_func_t *evict_func, 560 dmu_buf_t **clear_on_evict_dbufp); 561 #else /* __lint */ 562 inline void 563 dmu_buf_init_user(dmu_buf_user_t *dbu, dmu_buf_evict_func_t *evict_func, 564 dmu_buf_t **clear_on_evict_dbufp) 565 { 566 ASSERT(dbu->dbu_evict_func == NULL); 567 ASSERT(evict_func != NULL); 568 dbu->dbu_evict_func = evict_func; 569 #ifdef ZFS_DEBUG 570 dbu->dbu_clear_on_evict_dbufp = clear_on_evict_dbufp; 571 #endif 572 } 573 #endif /* __lint */ 574 575 /* 576 * Attach user data to a dbuf and mark it for normal (when the dbuf's 577 * data is cleared or its reference count goes to zero) eviction processing. 578 * 579 * Returns NULL on success, or the existing user if another user currently 580 * owns the buffer. 581 */ 582 void *dmu_buf_set_user(dmu_buf_t *db, dmu_buf_user_t *user); 583 584 /* 585 * Attach user data to a dbuf and mark it for immediate (its dirty and 586 * reference counts are equal) eviction processing. 587 * 588 * Returns NULL on success, or the existing user if another user currently 589 * owns the buffer. 590 */ 591 void *dmu_buf_set_user_ie(dmu_buf_t *db, dmu_buf_user_t *user); 592 593 /* 594 * Replace the current user of a dbuf. 595 * 596 * If given the current user of a dbuf, replaces the dbuf's user with 597 * "new_user" and returns the user data pointer that was replaced. 598 * Otherwise returns the current, and unmodified, dbuf user pointer. 599 */ 600 void *dmu_buf_replace_user(dmu_buf_t *db, 601 dmu_buf_user_t *old_user, dmu_buf_user_t *new_user); 602 603 /* 604 * Remove the specified user data for a DMU buffer. 605 * 606 * Returns the user that was removed on success, or the current user if 607 * another user currently owns the buffer. 608 */ 609 void *dmu_buf_remove_user(dmu_buf_t *db, dmu_buf_user_t *user); 610 611 /* 612 * Returns the user data (dmu_buf_user_t *) associated with this dbuf. 613 */ 614 void *dmu_buf_get_user(dmu_buf_t *db); 615 616 /* Block until any in-progress dmu buf user evictions complete. */ 617 void dmu_buf_user_evict_wait(void); 618 619 /* 620 * Returns the blkptr associated with this dbuf, or NULL if not set. 621 */ 622 struct blkptr *dmu_buf_get_blkptr(dmu_buf_t *db); 623 624 /* 625 * Indicate that you are going to modify the buffer's data (db_data). 626 * 627 * The transaction (tx) must be assigned to a txg (ie. you've called 628 * dmu_tx_assign()). The buffer's object must be held in the tx 629 * (ie. you've called dmu_tx_hold_object(tx, db->db_object)). 630 */ 631 void dmu_buf_will_dirty(dmu_buf_t *db, dmu_tx_t *tx); 632 633 /* 634 * Tells if the given dbuf is freeable. 635 */ 636 boolean_t dmu_buf_freeable(dmu_buf_t *); 637 638 /* 639 * You must create a transaction, then hold the objects which you will 640 * (or might) modify as part of this transaction. Then you must assign 641 * the transaction to a transaction group. Once the transaction has 642 * been assigned, you can modify buffers which belong to held objects as 643 * part of this transaction. You can't modify buffers before the 644 * transaction has been assigned; you can't modify buffers which don't 645 * belong to objects which this transaction holds; you can't hold 646 * objects once the transaction has been assigned. You may hold an 647 * object which you are going to free (with dmu_object_free()), but you 648 * don't have to. 649 * 650 * You can abort the transaction before it has been assigned. 651 * 652 * Note that you may hold buffers (with dmu_buf_hold) at any time, 653 * regardless of transaction state. 654 */ 655 656 #define DMU_NEW_OBJECT (-1ULL) 657 #define DMU_OBJECT_END (-1ULL) 658 659 dmu_tx_t *dmu_tx_create(objset_t *os); 660 void dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len); 661 void dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off, 662 uint64_t len); 663 void dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name); 664 void dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object); 665 void dmu_tx_hold_spill(dmu_tx_t *tx, uint64_t object); 666 void dmu_tx_hold_sa(dmu_tx_t *tx, struct sa_handle *hdl, boolean_t may_grow); 667 void dmu_tx_hold_sa_create(dmu_tx_t *tx, int total_size); 668 void dmu_tx_abort(dmu_tx_t *tx); 669 int dmu_tx_assign(dmu_tx_t *tx, enum txg_how txg_how); 670 void dmu_tx_wait(dmu_tx_t *tx); 671 void dmu_tx_commit(dmu_tx_t *tx); 672 void dmu_tx_mark_netfree(dmu_tx_t *tx); 673 674 /* 675 * To register a commit callback, dmu_tx_callback_register() must be called. 676 * 677 * dcb_data is a pointer to caller private data that is passed on as a 678 * callback parameter. The caller is responsible for properly allocating and 679 * freeing it. 680 * 681 * When registering a callback, the transaction must be already created, but 682 * it cannot be committed or aborted. It can be assigned to a txg or not. 683 * 684 * The callback will be called after the transaction has been safely written 685 * to stable storage and will also be called if the dmu_tx is aborted. 686 * If there is any error which prevents the transaction from being committed to 687 * disk, the callback will be called with a value of error != 0. 688 */ 689 typedef void dmu_tx_callback_func_t(void *dcb_data, int error); 690 691 void dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *dcb_func, 692 void *dcb_data); 693 694 /* 695 * Free up the data blocks for a defined range of a file. If size is 696 * -1, the range from offset to end-of-file is freed. 697 */ 698 int dmu_free_range(objset_t *os, uint64_t object, uint64_t offset, 699 uint64_t size, dmu_tx_t *tx); 700 int dmu_free_long_range(objset_t *os, uint64_t object, uint64_t offset, 701 uint64_t size); 702 int dmu_free_long_object(objset_t *os, uint64_t object); 703 704 /* 705 * Convenience functions. 706 * 707 * Canfail routines will return 0 on success, or an errno if there is a 708 * nonrecoverable I/O error. 709 */ 710 #define DMU_READ_PREFETCH 0 /* prefetch */ 711 #define DMU_READ_NO_PREFETCH 1 /* don't prefetch */ 712 int dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 713 void *buf, uint32_t flags); 714 void dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 715 const void *buf, dmu_tx_t *tx); 716 void dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 717 dmu_tx_t *tx); 718 int dmu_read_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size); 719 int dmu_read_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size); 720 int dmu_write_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size, 721 dmu_tx_t *tx); 722 int dmu_write_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size, 723 dmu_tx_t *tx); 724 int dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset, 725 uint64_t size, struct page *pp, dmu_tx_t *tx); 726 struct arc_buf *dmu_request_arcbuf(dmu_buf_t *handle, int size); 727 void dmu_return_arcbuf(struct arc_buf *buf); 728 void dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, struct arc_buf *buf, 729 dmu_tx_t *tx); 730 int dmu_xuio_init(struct xuio *uio, int niov); 731 void dmu_xuio_fini(struct xuio *uio); 732 int dmu_xuio_add(struct xuio *uio, struct arc_buf *abuf, offset_t off, 733 size_t n); 734 int dmu_xuio_cnt(struct xuio *uio); 735 struct arc_buf *dmu_xuio_arcbuf(struct xuio *uio, int i); 736 void dmu_xuio_clear(struct xuio *uio, int i); 737 void xuio_stat_wbuf_copied(); 738 void xuio_stat_wbuf_nocopy(); 739 740 extern boolean_t zfs_prefetch_disable; 741 extern int zfs_max_recordsize; 742 743 /* 744 * Asynchronously try to read in the data. 745 */ 746 void dmu_prefetch(objset_t *os, uint64_t object, int64_t level, uint64_t offset, 747 uint64_t len, enum zio_priority pri); 748 749 typedef struct dmu_object_info { 750 /* All sizes are in bytes unless otherwise indicated. */ 751 uint32_t doi_data_block_size; 752 uint32_t doi_metadata_block_size; 753 dmu_object_type_t doi_type; 754 dmu_object_type_t doi_bonus_type; 755 uint64_t doi_bonus_size; 756 uint8_t doi_indirection; /* 2 = dnode->indirect->data */ 757 uint8_t doi_checksum; 758 uint8_t doi_compress; 759 uint8_t doi_nblkptr; 760 uint8_t doi_pad[4]; 761 uint64_t doi_physical_blocks_512; /* data + metadata, 512b blks */ 762 uint64_t doi_max_offset; 763 uint64_t doi_fill_count; /* number of non-empty blocks */ 764 } dmu_object_info_t; 765 766 typedef void arc_byteswap_func_t(void *buf, size_t size); 767 768 typedef struct dmu_object_type_info { 769 dmu_object_byteswap_t ot_byteswap; 770 boolean_t ot_metadata; 771 char *ot_name; 772 } dmu_object_type_info_t; 773 774 typedef struct dmu_object_byteswap_info { 775 arc_byteswap_func_t *ob_func; 776 char *ob_name; 777 } dmu_object_byteswap_info_t; 778 779 extern const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES]; 780 extern const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS]; 781 782 /* 783 * Get information on a DMU object. 784 * 785 * Return 0 on success or ENOENT if object is not allocated. 786 * 787 * If doi is NULL, just indicates whether the object exists. 788 */ 789 int dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi); 790 /* Like dmu_object_info, but faster if you have a held dnode in hand. */ 791 void dmu_object_info_from_dnode(struct dnode *dn, dmu_object_info_t *doi); 792 /* Like dmu_object_info, but faster if you have a held dbuf in hand. */ 793 void dmu_object_info_from_db(dmu_buf_t *db, dmu_object_info_t *doi); 794 /* 795 * Like dmu_object_info_from_db, but faster still when you only care about 796 * the size. This is specifically optimized for zfs_getattr(). 797 */ 798 void dmu_object_size_from_db(dmu_buf_t *db, uint32_t *blksize, 799 u_longlong_t *nblk512); 800 801 typedef struct dmu_objset_stats { 802 uint64_t dds_num_clones; /* number of clones of this */ 803 uint64_t dds_creation_txg; 804 uint64_t dds_guid; 805 dmu_objset_type_t dds_type; 806 uint8_t dds_is_snapshot; 807 uint8_t dds_inconsistent; 808 char dds_origin[MAXNAMELEN]; 809 } dmu_objset_stats_t; 810 811 /* 812 * Get stats on a dataset. 813 */ 814 void dmu_objset_fast_stat(objset_t *os, dmu_objset_stats_t *stat); 815 816 /* 817 * Add entries to the nvlist for all the objset's properties. See 818 * zfs_prop_table[] and zfs(1m) for details on the properties. 819 */ 820 void dmu_objset_stats(objset_t *os, struct nvlist *nv); 821 822 /* 823 * Get the space usage statistics for statvfs(). 824 * 825 * refdbytes is the amount of space "referenced" by this objset. 826 * availbytes is the amount of space available to this objset, taking 827 * into account quotas & reservations, assuming that no other objsets 828 * use the space first. These values correspond to the 'referenced' and 829 * 'available' properties, described in the zfs(1m) manpage. 830 * 831 * usedobjs and availobjs are the number of objects currently allocated, 832 * and available. 833 */ 834 void dmu_objset_space(objset_t *os, uint64_t *refdbytesp, uint64_t *availbytesp, 835 uint64_t *usedobjsp, uint64_t *availobjsp); 836 837 /* 838 * The fsid_guid is a 56-bit ID that can change to avoid collisions. 839 * (Contrast with the ds_guid which is a 64-bit ID that will never 840 * change, so there is a small probability that it will collide.) 841 */ 842 uint64_t dmu_objset_fsid_guid(objset_t *os); 843 844 /* 845 * Get the [cm]time for an objset's snapshot dir 846 */ 847 timestruc_t dmu_objset_snap_cmtime(objset_t *os); 848 849 int dmu_objset_is_snapshot(objset_t *os); 850 851 extern struct spa *dmu_objset_spa(objset_t *os); 852 extern struct zilog *dmu_objset_zil(objset_t *os); 853 extern struct dsl_pool *dmu_objset_pool(objset_t *os); 854 extern struct dsl_dataset *dmu_objset_ds(objset_t *os); 855 extern void dmu_objset_name(objset_t *os, char *buf); 856 extern dmu_objset_type_t dmu_objset_type(objset_t *os); 857 extern uint64_t dmu_objset_id(objset_t *os); 858 extern zfs_sync_type_t dmu_objset_syncprop(objset_t *os); 859 extern zfs_logbias_op_t dmu_objset_logbias(objset_t *os); 860 extern int dmu_snapshot_list_next(objset_t *os, int namelen, char *name, 861 uint64_t *id, uint64_t *offp, boolean_t *case_conflict); 862 extern int dmu_snapshot_realname(objset_t *os, char *name, char *real, 863 int maxlen, boolean_t *conflict); 864 extern int dmu_dir_list_next(objset_t *os, int namelen, char *name, 865 uint64_t *idp, uint64_t *offp); 866 867 typedef int objset_used_cb_t(dmu_object_type_t bonustype, 868 void *bonus, uint64_t *userp, uint64_t *groupp); 869 extern void dmu_objset_register_type(dmu_objset_type_t ost, 870 objset_used_cb_t *cb); 871 extern void dmu_objset_set_user(objset_t *os, void *user_ptr); 872 extern void *dmu_objset_get_user(objset_t *os); 873 874 /* 875 * Return the txg number for the given assigned transaction. 876 */ 877 uint64_t dmu_tx_get_txg(dmu_tx_t *tx); 878 879 /* 880 * Synchronous write. 881 * If a parent zio is provided this function initiates a write on the 882 * provided buffer as a child of the parent zio. 883 * In the absence of a parent zio, the write is completed synchronously. 884 * At write completion, blk is filled with the bp of the written block. 885 * Note that while the data covered by this function will be on stable 886 * storage when the write completes this new data does not become a 887 * permanent part of the file until the associated transaction commits. 888 */ 889 890 /* 891 * {zfs,zvol,ztest}_get_done() args 892 */ 893 typedef struct zgd { 894 struct zilog *zgd_zilog; 895 struct blkptr *zgd_bp; 896 dmu_buf_t *zgd_db; 897 struct rl *zgd_rl; 898 void *zgd_private; 899 } zgd_t; 900 901 typedef void dmu_sync_cb_t(zgd_t *arg, int error); 902 int dmu_sync(struct zio *zio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd); 903 904 /* 905 * Find the next hole or data block in file starting at *off 906 * Return found offset in *off. Return ESRCH for end of file. 907 */ 908 int dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole, 909 uint64_t *off); 910 911 /* 912 * Check if a DMU object has any dirty blocks. If so, sync out 913 * all pending transaction groups. Otherwise, this function 914 * does not alter DMU state. This could be improved to only sync 915 * out the necessary transaction groups for this particular 916 * object. 917 */ 918 int dmu_object_wait_synced(objset_t *os, uint64_t object); 919 920 /* 921 * Initial setup and final teardown. 922 */ 923 extern void dmu_init(void); 924 extern void dmu_fini(void); 925 926 typedef void (*dmu_traverse_cb_t)(objset_t *os, void *arg, struct blkptr *bp, 927 uint64_t object, uint64_t offset, int len); 928 void dmu_traverse_objset(objset_t *os, uint64_t txg_start, 929 dmu_traverse_cb_t cb, void *arg); 930 931 int dmu_diff(const char *tosnap_name, const char *fromsnap_name, 932 struct vnode *vp, offset_t *offp); 933 934 /* CRC64 table */ 935 #define ZFS_CRC64_POLY 0xC96C5795D7870F42ULL /* ECMA-182, reflected form */ 936 extern uint64_t zfs_crc64_table[256]; 937 938 extern int zfs_mdcomp_disable; 939 940 #ifdef __cplusplus 941 } 942 #endif 943 944 #endif /* _SYS_DMU_H */ 945