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) 246 247 /* 248 * The maximum number of bytes that can be accessed as part of one 249 * operation, including metadata. 250 */ 251 #define DMU_MAX_ACCESS (32 * 1024 * 1024) /* 32MB */ 252 #define DMU_MAX_DELETEBLKCNT (20480) /* ~5MB of indirect blocks */ 253 254 #define DMU_USERUSED_OBJECT (-1ULL) 255 #define DMU_GROUPUSED_OBJECT (-2ULL) 256 257 /* 258 * artificial blkids for bonus buffer and spill blocks 259 */ 260 #define DMU_BONUS_BLKID (-1ULL) 261 #define DMU_SPILL_BLKID (-2ULL) 262 /* 263 * Public routines to create, destroy, open, and close objsets. 264 */ 265 int dmu_objset_hold(const char *name, void *tag, objset_t **osp); 266 int dmu_objset_own(const char *name, dmu_objset_type_t type, 267 boolean_t readonly, void *tag, objset_t **osp); 268 void dmu_objset_rele(objset_t *os, void *tag); 269 void dmu_objset_disown(objset_t *os, void *tag); 270 int dmu_objset_open_ds(struct dsl_dataset *ds, objset_t **osp); 271 272 void dmu_objset_evict_dbufs(objset_t *os); 273 int dmu_objset_create(const char *name, dmu_objset_type_t type, uint64_t flags, 274 void (*func)(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx), void *arg); 275 int dmu_objset_clone(const char *name, const char *origin); 276 int dsl_destroy_snapshots_nvl(struct nvlist *snaps, boolean_t defer, 277 struct nvlist *errlist); 278 int dmu_objset_snapshot_one(const char *fsname, const char *snapname); 279 int dmu_objset_snapshot_tmp(const char *, const char *, int); 280 int dmu_objset_find(char *name, int func(const char *, void *), void *arg, 281 int flags); 282 void dmu_objset_byteswap(void *buf, size_t size); 283 int dsl_dataset_rename_snapshot(const char *fsname, 284 const char *oldsnapname, const char *newsnapname, boolean_t recursive); 285 286 typedef struct dmu_buf { 287 uint64_t db_object; /* object that this buffer is part of */ 288 uint64_t db_offset; /* byte offset in this object */ 289 uint64_t db_size; /* size of buffer in bytes */ 290 void *db_data; /* data in buffer */ 291 } dmu_buf_t; 292 293 /* 294 * The names of zap entries in the DIRECTORY_OBJECT of the MOS. 295 */ 296 #define DMU_POOL_DIRECTORY_OBJECT 1 297 #define DMU_POOL_CONFIG "config" 298 #define DMU_POOL_FEATURES_FOR_WRITE "features_for_write" 299 #define DMU_POOL_FEATURES_FOR_READ "features_for_read" 300 #define DMU_POOL_FEATURE_DESCRIPTIONS "feature_descriptions" 301 #define DMU_POOL_FEATURE_ENABLED_TXG "feature_enabled_txg" 302 #define DMU_POOL_ROOT_DATASET "root_dataset" 303 #define DMU_POOL_SYNC_BPOBJ "sync_bplist" 304 #define DMU_POOL_ERRLOG_SCRUB "errlog_scrub" 305 #define DMU_POOL_ERRLOG_LAST "errlog_last" 306 #define DMU_POOL_SPARES "spares" 307 #define DMU_POOL_DEFLATE "deflate" 308 #define DMU_POOL_HISTORY "history" 309 #define DMU_POOL_PROPS "pool_props" 310 #define DMU_POOL_L2CACHE "l2cache" 311 #define DMU_POOL_TMP_USERREFS "tmp_userrefs" 312 #define DMU_POOL_DDT "DDT-%s-%s-%s" 313 #define DMU_POOL_DDT_STATS "DDT-statistics" 314 #define DMU_POOL_CREATION_VERSION "creation_version" 315 #define DMU_POOL_SCAN "scan" 316 #define DMU_POOL_FREE_BPOBJ "free_bpobj" 317 #define DMU_POOL_BPTREE_OBJ "bptree_obj" 318 #define DMU_POOL_EMPTY_BPOBJ "empty_bpobj" 319 320 /* 321 * Allocate an object from this objset. The range of object numbers 322 * available is (0, DN_MAX_OBJECT). Object 0 is the meta-dnode. 323 * 324 * The transaction must be assigned to a txg. The newly allocated 325 * object will be "held" in the transaction (ie. you can modify the 326 * newly allocated object in this transaction). 327 * 328 * dmu_object_alloc() chooses an object and returns it in *objectp. 329 * 330 * dmu_object_claim() allocates a specific object number. If that 331 * number is already allocated, it fails and returns EEXIST. 332 * 333 * Return 0 on success, or ENOSPC or EEXIST as specified above. 334 */ 335 uint64_t dmu_object_alloc(objset_t *os, dmu_object_type_t ot, 336 int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx); 337 int dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot, 338 int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx); 339 int dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot, 340 int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *txp); 341 342 /* 343 * Free an object from this objset. 344 * 345 * The object's data will be freed as well (ie. you don't need to call 346 * dmu_free(object, 0, -1, tx)). 347 * 348 * The object need not be held in the transaction. 349 * 350 * If there are any holds on this object's buffers (via dmu_buf_hold()), 351 * or tx holds on the object (via dmu_tx_hold_object()), you can not 352 * free it; it fails and returns EBUSY. 353 * 354 * If the object is not allocated, it fails and returns ENOENT. 355 * 356 * Return 0 on success, or EBUSY or ENOENT as specified above. 357 */ 358 int dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx); 359 360 /* 361 * Find the next allocated or free object. 362 * 363 * The objectp parameter is in-out. It will be updated to be the next 364 * object which is allocated. Ignore objects which have not been 365 * modified since txg. 366 * 367 * XXX Can only be called on a objset with no dirty data. 368 * 369 * Returns 0 on success, or ENOENT if there are no more objects. 370 */ 371 int dmu_object_next(objset_t *os, uint64_t *objectp, 372 boolean_t hole, uint64_t txg); 373 374 /* 375 * Set the data blocksize for an object. 376 * 377 * The object cannot have any blocks allcated beyond the first. If 378 * the first block is allocated already, the new size must be greater 379 * than the current block size. If these conditions are not met, 380 * ENOTSUP will be returned. 381 * 382 * Returns 0 on success, or EBUSY if there are any holds on the object 383 * contents, or ENOTSUP as described above. 384 */ 385 int dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size, 386 int ibs, dmu_tx_t *tx); 387 388 /* 389 * Set the checksum property on a dnode. The new checksum algorithm will 390 * apply to all newly written blocks; existing blocks will not be affected. 391 */ 392 void dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum, 393 dmu_tx_t *tx); 394 395 /* 396 * Set the compress property on a dnode. The new compression algorithm will 397 * apply to all newly written blocks; existing blocks will not be affected. 398 */ 399 void dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress, 400 dmu_tx_t *tx); 401 402 void 403 dmu_write_embedded(objset_t *os, uint64_t object, uint64_t offset, 404 void *data, uint8_t etype, uint8_t comp, int uncompressed_size, 405 int compressed_size, int byteorder, dmu_tx_t *tx); 406 407 /* 408 * Decide how to write a block: checksum, compression, number of copies, etc. 409 */ 410 #define WP_NOFILL 0x1 411 #define WP_DMU_SYNC 0x2 412 #define WP_SPILL 0x4 413 414 void dmu_write_policy(objset_t *os, struct dnode *dn, int level, int wp, 415 struct zio_prop *zp); 416 /* 417 * The bonus data is accessed more or less like a regular buffer. 418 * You must dmu_bonus_hold() to get the buffer, which will give you a 419 * dmu_buf_t with db_offset==-1ULL, and db_size = the size of the bonus 420 * data. As with any normal buffer, you must call dmu_buf_read() to 421 * read db_data, dmu_buf_will_dirty() before modifying it, and the 422 * object must be held in an assigned transaction before calling 423 * dmu_buf_will_dirty. You may use dmu_buf_set_user() on the bonus 424 * buffer as well. You must release your hold with dmu_buf_rele(). 425 * 426 * Returns ENOENT, EIO, or 0. 427 */ 428 int dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **); 429 int dmu_bonus_max(void); 430 int dmu_set_bonus(dmu_buf_t *, int, dmu_tx_t *); 431 int dmu_set_bonustype(dmu_buf_t *, dmu_object_type_t, dmu_tx_t *); 432 dmu_object_type_t dmu_get_bonustype(dmu_buf_t *); 433 int dmu_rm_spill(objset_t *, uint64_t, dmu_tx_t *); 434 435 /* 436 * Special spill buffer support used by "SA" framework 437 */ 438 439 int dmu_spill_hold_by_bonus(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp); 440 int dmu_spill_hold_by_dnode(struct dnode *dn, uint32_t flags, 441 void *tag, dmu_buf_t **dbp); 442 int dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp); 443 444 /* 445 * Obtain the DMU buffer from the specified object which contains the 446 * specified offset. dmu_buf_hold() puts a "hold" on the buffer, so 447 * that it will remain in memory. You must release the hold with 448 * dmu_buf_rele(). You musn't access the dmu_buf_t after releasing your 449 * hold. You must have a hold on any dmu_buf_t* you pass to the DMU. 450 * 451 * You must call dmu_buf_read, dmu_buf_will_dirty, or dmu_buf_will_fill 452 * on the returned buffer before reading or writing the buffer's 453 * db_data. The comments for those routines describe what particular 454 * operations are valid after calling them. 455 * 456 * The object number must be a valid, allocated object number. 457 */ 458 int dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset, 459 void *tag, dmu_buf_t **, int flags); 460 461 /* 462 * Add a reference to a dmu buffer that has already been held via 463 * dmu_buf_hold() in the current context. 464 */ 465 void dmu_buf_add_ref(dmu_buf_t *db, void* tag); 466 467 /* 468 * Attempt to add a reference to a dmu buffer that is in an unknown state, 469 * using a pointer that may have been invalidated by eviction processing. 470 * The request will succeed if the passed in dbuf still represents the 471 * same os/object/blkid, is ineligible for eviction, and has at least 472 * one hold by a user other than the syncer. 473 */ 474 boolean_t dmu_buf_try_add_ref(dmu_buf_t *, objset_t *os, uint64_t object, 475 uint64_t blkid, void *tag); 476 477 void dmu_buf_rele(dmu_buf_t *db, void *tag); 478 uint64_t dmu_buf_refcount(dmu_buf_t *db); 479 480 /* 481 * dmu_buf_hold_array holds the DMU buffers which contain all bytes in a 482 * range of an object. A pointer to an array of dmu_buf_t*'s is 483 * returned (in *dbpp). 484 * 485 * dmu_buf_rele_array releases the hold on an array of dmu_buf_t*'s, and 486 * frees the array. The hold on the array of buffers MUST be released 487 * with dmu_buf_rele_array. You can NOT release the hold on each buffer 488 * individually with dmu_buf_rele. 489 */ 490 int dmu_buf_hold_array_by_bonus(dmu_buf_t *db, uint64_t offset, 491 uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp); 492 void dmu_buf_rele_array(dmu_buf_t **, int numbufs, void *tag); 493 494 typedef void dmu_buf_evict_func_t(void *user_ptr); 495 496 /* 497 * A DMU buffer user object may be associated with a dbuf for the 498 * duration of its lifetime. This allows the user of a dbuf (client) 499 * to attach private data to a dbuf (e.g. in-core only data such as a 500 * dnode_children_t, zap_t, or zap_leaf_t) and be optionally notified 501 * when that dbuf has been evicted. Clients typically respond to the 502 * eviction notification by freeing their private data, thus ensuring 503 * the same lifetime for both dbuf and private data. 504 * 505 * The mapping from a dmu_buf_user_t to any client private data is the 506 * client's responsibility. All current consumers of the API with private 507 * data embed a dmu_buf_user_t as the first member of the structure for 508 * their private data. This allows conversions between the two types 509 * with a simple cast. Since the DMU buf user API never needs access 510 * to the private data, other strategies can be employed if necessary 511 * or convenient for the client (e.g. using container_of() to do the 512 * conversion for private data that cannot have the dmu_buf_user_t as 513 * its first member). 514 * 515 * Eviction callbacks are executed without the dbuf mutex held or any 516 * other type of mechanism to guarantee that the dbuf is still available. 517 * For this reason, users must assume the dbuf has already been freed 518 * and not reference the dbuf from the callback context. 519 * 520 * Users requesting "immediate eviction" are notified as soon as the dbuf 521 * is only referenced by dirty records (dirties == holds). Otherwise the 522 * notification occurs after eviction processing for the dbuf begins. 523 */ 524 typedef struct dmu_buf_user { 525 /* 526 * Asynchronous user eviction callback state. 527 */ 528 taskq_ent_t dbu_tqent; 529 530 /* This instance's eviction function pointer. */ 531 dmu_buf_evict_func_t *dbu_evict_func; 532 #ifdef ZFS_DEBUG 533 /* 534 * Pointer to user's dbuf pointer. NULL for clients that do 535 * not associate a dbuf with their user data. 536 * 537 * The dbuf pointer is cleared upon eviction so as to catch 538 * use-after-evict bugs in clients. 539 */ 540 dmu_buf_t **dbu_clear_on_evict_dbufp; 541 #endif 542 } dmu_buf_user_t; 543 544 /* 545 * Initialize the given dmu_buf_user_t instance with the eviction function 546 * evict_func, to be called when the user is evicted. 547 * 548 * NOTE: This function should only be called once on a given dmu_buf_user_t. 549 * To allow enforcement of this, dbu must already be zeroed on entry. 550 */ 551 #ifdef __lint 552 /* Very ugly, but it beats issuing suppression directives in many Makefiles. */ 553 extern void 554 dmu_buf_init_user(dmu_buf_user_t *dbu, dmu_buf_evict_func_t *evict_func, 555 dmu_buf_t **clear_on_evict_dbufp); 556 #else /* __lint */ 557 inline void 558 dmu_buf_init_user(dmu_buf_user_t *dbu, dmu_buf_evict_func_t *evict_func, 559 dmu_buf_t **clear_on_evict_dbufp) 560 { 561 ASSERT(dbu->dbu_evict_func == NULL); 562 ASSERT(evict_func != NULL); 563 dbu->dbu_evict_func = evict_func; 564 #ifdef ZFS_DEBUG 565 dbu->dbu_clear_on_evict_dbufp = clear_on_evict_dbufp; 566 #endif 567 } 568 #endif /* __lint */ 569 570 /* 571 * Attach user data to a dbuf and mark it for normal (when the dbuf's 572 * data is cleared or its reference count goes to zero) eviction processing. 573 * 574 * Returns NULL on success, or the existing user if another user currently 575 * owns the buffer. 576 */ 577 void *dmu_buf_set_user(dmu_buf_t *db, dmu_buf_user_t *user); 578 579 /* 580 * Attach user data to a dbuf and mark it for immediate (its dirty and 581 * reference counts are equal) eviction processing. 582 * 583 * Returns NULL on success, or the existing user if another user currently 584 * owns the buffer. 585 */ 586 void *dmu_buf_set_user_ie(dmu_buf_t *db, dmu_buf_user_t *user); 587 588 /* 589 * Replace the current user of a dbuf. 590 * 591 * If given the current user of a dbuf, replaces the dbuf's user with 592 * "new_user" and returns the user data pointer that was replaced. 593 * Otherwise returns the current, and unmodified, dbuf user pointer. 594 */ 595 void *dmu_buf_replace_user(dmu_buf_t *db, 596 dmu_buf_user_t *old_user, dmu_buf_user_t *new_user); 597 598 /* 599 * Remove the specified user data for a DMU buffer. 600 * 601 * Returns the user that was removed on success, or the current user if 602 * another user currently owns the buffer. 603 */ 604 void *dmu_buf_remove_user(dmu_buf_t *db, dmu_buf_user_t *user); 605 606 /* 607 * Returns the user data (dmu_buf_user_t *) associated with this dbuf. 608 */ 609 void *dmu_buf_get_user(dmu_buf_t *db); 610 611 /* Block until any in-progress dmu buf user evictions complete. */ 612 void dmu_buf_user_evict_wait(void); 613 614 /* 615 * Returns the blkptr associated with this dbuf, or NULL if not set. 616 */ 617 struct blkptr *dmu_buf_get_blkptr(dmu_buf_t *db); 618 619 /* 620 * Indicate that you are going to modify the buffer's data (db_data). 621 * 622 * The transaction (tx) must be assigned to a txg (ie. you've called 623 * dmu_tx_assign()). The buffer's object must be held in the tx 624 * (ie. you've called dmu_tx_hold_object(tx, db->db_object)). 625 */ 626 void dmu_buf_will_dirty(dmu_buf_t *db, dmu_tx_t *tx); 627 628 /* 629 * Tells if the given dbuf is freeable. 630 */ 631 boolean_t dmu_buf_freeable(dmu_buf_t *); 632 633 /* 634 * You must create a transaction, then hold the objects which you will 635 * (or might) modify as part of this transaction. Then you must assign 636 * the transaction to a transaction group. Once the transaction has 637 * been assigned, you can modify buffers which belong to held objects as 638 * part of this transaction. You can't modify buffers before the 639 * transaction has been assigned; you can't modify buffers which don't 640 * belong to objects which this transaction holds; you can't hold 641 * objects once the transaction has been assigned. You may hold an 642 * object which you are going to free (with dmu_object_free()), but you 643 * don't have to. 644 * 645 * You can abort the transaction before it has been assigned. 646 * 647 * Note that you may hold buffers (with dmu_buf_hold) at any time, 648 * regardless of transaction state. 649 */ 650 651 #define DMU_NEW_OBJECT (-1ULL) 652 #define DMU_OBJECT_END (-1ULL) 653 654 dmu_tx_t *dmu_tx_create(objset_t *os); 655 void dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len); 656 void dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off, 657 uint64_t len); 658 void dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name); 659 void dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object); 660 void dmu_tx_hold_spill(dmu_tx_t *tx, uint64_t object); 661 void dmu_tx_hold_sa(dmu_tx_t *tx, struct sa_handle *hdl, boolean_t may_grow); 662 void dmu_tx_hold_sa_create(dmu_tx_t *tx, int total_size); 663 void dmu_tx_abort(dmu_tx_t *tx); 664 int dmu_tx_assign(dmu_tx_t *tx, enum txg_how txg_how); 665 void dmu_tx_wait(dmu_tx_t *tx); 666 void dmu_tx_commit(dmu_tx_t *tx); 667 void dmu_tx_mark_netfree(dmu_tx_t *tx); 668 669 /* 670 * To register a commit callback, dmu_tx_callback_register() must be called. 671 * 672 * dcb_data is a pointer to caller private data that is passed on as a 673 * callback parameter. The caller is responsible for properly allocating and 674 * freeing it. 675 * 676 * When registering a callback, the transaction must be already created, but 677 * it cannot be committed or aborted. It can be assigned to a txg or not. 678 * 679 * The callback will be called after the transaction has been safely written 680 * to stable storage and will also be called if the dmu_tx is aborted. 681 * If there is any error which prevents the transaction from being committed to 682 * disk, the callback will be called with a value of error != 0. 683 */ 684 typedef void dmu_tx_callback_func_t(void *dcb_data, int error); 685 686 void dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *dcb_func, 687 void *dcb_data); 688 689 /* 690 * Free up the data blocks for a defined range of a file. If size is 691 * -1, the range from offset to end-of-file is freed. 692 */ 693 int dmu_free_range(objset_t *os, uint64_t object, uint64_t offset, 694 uint64_t size, dmu_tx_t *tx); 695 int dmu_free_long_range(objset_t *os, uint64_t object, uint64_t offset, 696 uint64_t size); 697 int dmu_free_long_object(objset_t *os, uint64_t object); 698 699 /* 700 * Convenience functions. 701 * 702 * Canfail routines will return 0 on success, or an errno if there is a 703 * nonrecoverable I/O error. 704 */ 705 #define DMU_READ_PREFETCH 0 /* prefetch */ 706 #define DMU_READ_NO_PREFETCH 1 /* don't prefetch */ 707 int dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 708 void *buf, uint32_t flags); 709 void dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 710 const void *buf, dmu_tx_t *tx); 711 void dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 712 dmu_tx_t *tx); 713 int dmu_read_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size); 714 int dmu_read_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size); 715 int dmu_write_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size, 716 dmu_tx_t *tx); 717 int dmu_write_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size, 718 dmu_tx_t *tx); 719 int dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset, 720 uint64_t size, struct page *pp, dmu_tx_t *tx); 721 struct arc_buf *dmu_request_arcbuf(dmu_buf_t *handle, int size); 722 void dmu_return_arcbuf(struct arc_buf *buf); 723 void dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, struct arc_buf *buf, 724 dmu_tx_t *tx); 725 int dmu_xuio_init(struct xuio *uio, int niov); 726 void dmu_xuio_fini(struct xuio *uio); 727 int dmu_xuio_add(struct xuio *uio, struct arc_buf *abuf, offset_t off, 728 size_t n); 729 int dmu_xuio_cnt(struct xuio *uio); 730 struct arc_buf *dmu_xuio_arcbuf(struct xuio *uio, int i); 731 void dmu_xuio_clear(struct xuio *uio, int i); 732 void xuio_stat_wbuf_copied(); 733 void xuio_stat_wbuf_nocopy(); 734 735 extern int zfs_prefetch_disable; 736 extern int zfs_max_recordsize; 737 738 /* 739 * Asynchronously try to read in the data. 740 */ 741 void dmu_prefetch(objset_t *os, uint64_t object, uint64_t offset, 742 uint64_t len); 743 744 typedef struct dmu_object_info { 745 /* All sizes are in bytes unless otherwise indicated. */ 746 uint32_t doi_data_block_size; 747 uint32_t doi_metadata_block_size; 748 dmu_object_type_t doi_type; 749 dmu_object_type_t doi_bonus_type; 750 uint64_t doi_bonus_size; 751 uint8_t doi_indirection; /* 2 = dnode->indirect->data */ 752 uint8_t doi_checksum; 753 uint8_t doi_compress; 754 uint8_t doi_nblkptr; 755 uint8_t doi_pad[4]; 756 uint64_t doi_physical_blocks_512; /* data + metadata, 512b blks */ 757 uint64_t doi_max_offset; 758 uint64_t doi_fill_count; /* number of non-empty blocks */ 759 } dmu_object_info_t; 760 761 typedef void arc_byteswap_func_t(void *buf, size_t size); 762 763 typedef struct dmu_object_type_info { 764 dmu_object_byteswap_t ot_byteswap; 765 boolean_t ot_metadata; 766 char *ot_name; 767 } dmu_object_type_info_t; 768 769 typedef struct dmu_object_byteswap_info { 770 arc_byteswap_func_t *ob_func; 771 char *ob_name; 772 } dmu_object_byteswap_info_t; 773 774 extern const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES]; 775 extern const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS]; 776 777 /* 778 * Get information on a DMU object. 779 * 780 * Return 0 on success or ENOENT if object is not allocated. 781 * 782 * If doi is NULL, just indicates whether the object exists. 783 */ 784 int dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi); 785 /* Like dmu_object_info, but faster if you have a held dnode in hand. */ 786 void dmu_object_info_from_dnode(struct dnode *dn, dmu_object_info_t *doi); 787 /* Like dmu_object_info, but faster if you have a held dbuf in hand. */ 788 void dmu_object_info_from_db(dmu_buf_t *db, dmu_object_info_t *doi); 789 /* 790 * Like dmu_object_info_from_db, but faster still when you only care about 791 * the size. This is specifically optimized for zfs_getattr(). 792 */ 793 void dmu_object_size_from_db(dmu_buf_t *db, uint32_t *blksize, 794 u_longlong_t *nblk512); 795 796 typedef struct dmu_objset_stats { 797 uint64_t dds_num_clones; /* number of clones of this */ 798 uint64_t dds_creation_txg; 799 uint64_t dds_guid; 800 dmu_objset_type_t dds_type; 801 uint8_t dds_is_snapshot; 802 uint8_t dds_inconsistent; 803 char dds_origin[MAXNAMELEN]; 804 } dmu_objset_stats_t; 805 806 /* 807 * Get stats on a dataset. 808 */ 809 void dmu_objset_fast_stat(objset_t *os, dmu_objset_stats_t *stat); 810 811 /* 812 * Add entries to the nvlist for all the objset's properties. See 813 * zfs_prop_table[] and zfs(1m) for details on the properties. 814 */ 815 void dmu_objset_stats(objset_t *os, struct nvlist *nv); 816 817 /* 818 * Get the space usage statistics for statvfs(). 819 * 820 * refdbytes is the amount of space "referenced" by this objset. 821 * availbytes is the amount of space available to this objset, taking 822 * into account quotas & reservations, assuming that no other objsets 823 * use the space first. These values correspond to the 'referenced' and 824 * 'available' properties, described in the zfs(1m) manpage. 825 * 826 * usedobjs and availobjs are the number of objects currently allocated, 827 * and available. 828 */ 829 void dmu_objset_space(objset_t *os, uint64_t *refdbytesp, uint64_t *availbytesp, 830 uint64_t *usedobjsp, uint64_t *availobjsp); 831 832 /* 833 * The fsid_guid is a 56-bit ID that can change to avoid collisions. 834 * (Contrast with the ds_guid which is a 64-bit ID that will never 835 * change, so there is a small probability that it will collide.) 836 */ 837 uint64_t dmu_objset_fsid_guid(objset_t *os); 838 839 /* 840 * Get the [cm]time for an objset's snapshot dir 841 */ 842 timestruc_t dmu_objset_snap_cmtime(objset_t *os); 843 844 int dmu_objset_is_snapshot(objset_t *os); 845 846 extern struct spa *dmu_objset_spa(objset_t *os); 847 extern struct zilog *dmu_objset_zil(objset_t *os); 848 extern struct dsl_pool *dmu_objset_pool(objset_t *os); 849 extern struct dsl_dataset *dmu_objset_ds(objset_t *os); 850 extern void dmu_objset_name(objset_t *os, char *buf); 851 extern dmu_objset_type_t dmu_objset_type(objset_t *os); 852 extern uint64_t dmu_objset_id(objset_t *os); 853 extern zfs_sync_type_t dmu_objset_syncprop(objset_t *os); 854 extern zfs_logbias_op_t dmu_objset_logbias(objset_t *os); 855 extern int dmu_snapshot_list_next(objset_t *os, int namelen, char *name, 856 uint64_t *id, uint64_t *offp, boolean_t *case_conflict); 857 extern int dmu_snapshot_realname(objset_t *os, char *name, char *real, 858 int maxlen, boolean_t *conflict); 859 extern int dmu_dir_list_next(objset_t *os, int namelen, char *name, 860 uint64_t *idp, uint64_t *offp); 861 862 typedef int objset_used_cb_t(dmu_object_type_t bonustype, 863 void *bonus, uint64_t *userp, uint64_t *groupp); 864 extern void dmu_objset_register_type(dmu_objset_type_t ost, 865 objset_used_cb_t *cb); 866 extern void dmu_objset_set_user(objset_t *os, void *user_ptr); 867 extern void *dmu_objset_get_user(objset_t *os); 868 869 /* 870 * Return the txg number for the given assigned transaction. 871 */ 872 uint64_t dmu_tx_get_txg(dmu_tx_t *tx); 873 874 /* 875 * Synchronous write. 876 * If a parent zio is provided this function initiates a write on the 877 * provided buffer as a child of the parent zio. 878 * In the absence of a parent zio, the write is completed synchronously. 879 * At write completion, blk is filled with the bp of the written block. 880 * Note that while the data covered by this function will be on stable 881 * storage when the write completes this new data does not become a 882 * permanent part of the file until the associated transaction commits. 883 */ 884 885 /* 886 * {zfs,zvol,ztest}_get_done() args 887 */ 888 typedef struct zgd { 889 struct zilog *zgd_zilog; 890 struct blkptr *zgd_bp; 891 dmu_buf_t *zgd_db; 892 struct rl *zgd_rl; 893 void *zgd_private; 894 } zgd_t; 895 896 typedef void dmu_sync_cb_t(zgd_t *arg, int error); 897 int dmu_sync(struct zio *zio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd); 898 899 /* 900 * Find the next hole or data block in file starting at *off 901 * Return found offset in *off. Return ESRCH for end of file. 902 */ 903 int dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole, 904 uint64_t *off); 905 906 /* 907 * Check if a DMU object has any dirty blocks. If so, sync out 908 * all pending transaction groups. Otherwise, this function 909 * does not alter DMU state. This could be improved to only sync 910 * out the necessary transaction groups for this particular 911 * object. 912 */ 913 int dmu_object_wait_synced(objset_t *os, uint64_t object); 914 915 /* 916 * Initial setup and final teardown. 917 */ 918 extern void dmu_init(void); 919 extern void dmu_fini(void); 920 921 typedef void (*dmu_traverse_cb_t)(objset_t *os, void *arg, struct blkptr *bp, 922 uint64_t object, uint64_t offset, int len); 923 void dmu_traverse_objset(objset_t *os, uint64_t txg_start, 924 dmu_traverse_cb_t cb, void *arg); 925 926 int dmu_diff(const char *tosnap_name, const char *fromsnap_name, 927 struct vnode *vp, offset_t *offp); 928 929 /* CRC64 table */ 930 #define ZFS_CRC64_POLY 0xC96C5795D7870F42ULL /* ECMA-182, reflected form */ 931 extern uint64_t zfs_crc64_table[256]; 932 933 extern int zfs_mdcomp_disable; 934 935 #ifdef __cplusplus 936 } 937 #endif 938 939 #endif /* _SYS_DMU_H */ 940