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