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, 2017 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 * Copyright (c) 2014 Integros [integros.com] 32 */ 33 34 /* Portions Copyright 2010 Robert Milkowski */ 35 36 #ifndef _SYS_DMU_H 37 #define _SYS_DMU_H 38 39 /* 40 * This file describes the interface that the DMU provides for its 41 * consumers. 42 * 43 * The DMU also interacts with the SPA. That interface is described in 44 * dmu_spa.h. 45 */ 46 47 #include <sys/zfs_context.h> 48 #include <sys/inttypes.h> 49 #include <sys/cred.h> 50 #include <sys/fs/zfs.h> 51 #include <sys/zio_compress.h> 52 #include <sys/zio_priority.h> 53 54 #ifdef __cplusplus 55 extern "C" { 56 #endif 57 58 struct uio; 59 struct xuio; 60 struct page; 61 struct vnode; 62 struct spa; 63 struct zilog; 64 struct zio; 65 struct blkptr; 66 struct zap_cursor; 67 struct dsl_dataset; 68 struct dsl_pool; 69 struct dnode; 70 struct drr_begin; 71 struct drr_end; 72 struct zbookmark_phys; 73 struct spa; 74 struct nvlist; 75 struct arc_buf; 76 struct zio_prop; 77 struct sa_handle; 78 79 typedef struct objset objset_t; 80 typedef struct dmu_tx dmu_tx_t; 81 typedef struct dsl_dir dsl_dir_t; 82 typedef struct dnode dnode_t; 83 84 typedef enum dmu_object_byteswap { 85 DMU_BSWAP_UINT8, 86 DMU_BSWAP_UINT16, 87 DMU_BSWAP_UINT32, 88 DMU_BSWAP_UINT64, 89 DMU_BSWAP_ZAP, 90 DMU_BSWAP_DNODE, 91 DMU_BSWAP_OBJSET, 92 DMU_BSWAP_ZNODE, 93 DMU_BSWAP_OLDACL, 94 DMU_BSWAP_ACL, 95 /* 96 * Allocating a new byteswap type number makes the on-disk format 97 * incompatible with any other format that uses the same number. 98 * 99 * Data can usually be structured to work with one of the 100 * DMU_BSWAP_UINT* or DMU_BSWAP_ZAP types. 101 */ 102 DMU_BSWAP_NUMFUNCS 103 } dmu_object_byteswap_t; 104 105 #define DMU_OT_NEWTYPE 0x80 106 #define DMU_OT_METADATA 0x40 107 #define DMU_OT_BYTESWAP_MASK 0x3f 108 109 /* 110 * Defines a uint8_t object type. Object types specify if the data 111 * in the object is metadata (boolean) and how to byteswap the data 112 * (dmu_object_byteswap_t). 113 */ 114 #define DMU_OT(byteswap, metadata) \ 115 (DMU_OT_NEWTYPE | \ 116 ((metadata) ? DMU_OT_METADATA : 0) | \ 117 ((byteswap) & DMU_OT_BYTESWAP_MASK)) 118 119 #define DMU_OT_IS_VALID(ot) (((ot) & DMU_OT_NEWTYPE) ? \ 120 ((ot) & DMU_OT_BYTESWAP_MASK) < DMU_BSWAP_NUMFUNCS : \ 121 (ot) < DMU_OT_NUMTYPES) 122 123 #define DMU_OT_IS_METADATA(ot) (((ot) & DMU_OT_NEWTYPE) ? \ 124 ((ot) & DMU_OT_METADATA) : \ 125 dmu_ot[(ot)].ot_metadata) 126 127 /* 128 * These object types use bp_fill != 1 for their L0 bp's. Therefore they can't 129 * have their data embedded (i.e. use a BP_IS_EMBEDDED() bp), because bp_fill 130 * is repurposed for embedded BPs. 131 */ 132 #define DMU_OT_HAS_FILL(ot) \ 133 ((ot) == DMU_OT_DNODE || (ot) == DMU_OT_OBJSET) 134 135 #define DMU_OT_BYTESWAP(ot) (((ot) & DMU_OT_NEWTYPE) ? \ 136 ((ot) & DMU_OT_BYTESWAP_MASK) : \ 137 dmu_ot[(ot)].ot_byteswap) 138 139 typedef enum dmu_object_type { 140 DMU_OT_NONE, 141 /* general: */ 142 DMU_OT_OBJECT_DIRECTORY, /* ZAP */ 143 DMU_OT_OBJECT_ARRAY, /* UINT64 */ 144 DMU_OT_PACKED_NVLIST, /* UINT8 (XDR by nvlist_pack/unpack) */ 145 DMU_OT_PACKED_NVLIST_SIZE, /* UINT64 */ 146 DMU_OT_BPOBJ, /* UINT64 */ 147 DMU_OT_BPOBJ_HDR, /* UINT64 */ 148 /* spa: */ 149 DMU_OT_SPACE_MAP_HEADER, /* UINT64 */ 150 DMU_OT_SPACE_MAP, /* UINT64 */ 151 /* zil: */ 152 DMU_OT_INTENT_LOG, /* UINT64 */ 153 /* dmu: */ 154 DMU_OT_DNODE, /* DNODE */ 155 DMU_OT_OBJSET, /* OBJSET */ 156 /* dsl: */ 157 DMU_OT_DSL_DIR, /* UINT64 */ 158 DMU_OT_DSL_DIR_CHILD_MAP, /* ZAP */ 159 DMU_OT_DSL_DS_SNAP_MAP, /* ZAP */ 160 DMU_OT_DSL_PROPS, /* ZAP */ 161 DMU_OT_DSL_DATASET, /* UINT64 */ 162 /* zpl: */ 163 DMU_OT_ZNODE, /* ZNODE */ 164 DMU_OT_OLDACL, /* Old ACL */ 165 DMU_OT_PLAIN_FILE_CONTENTS, /* UINT8 */ 166 DMU_OT_DIRECTORY_CONTENTS, /* ZAP */ 167 DMU_OT_MASTER_NODE, /* ZAP */ 168 DMU_OT_UNLINKED_SET, /* ZAP */ 169 /* zvol: */ 170 DMU_OT_ZVOL, /* UINT8 */ 171 DMU_OT_ZVOL_PROP, /* ZAP */ 172 /* other; for testing only! */ 173 DMU_OT_PLAIN_OTHER, /* UINT8 */ 174 DMU_OT_UINT64_OTHER, /* UINT64 */ 175 DMU_OT_ZAP_OTHER, /* ZAP */ 176 /* new object types: */ 177 DMU_OT_ERROR_LOG, /* ZAP */ 178 DMU_OT_SPA_HISTORY, /* UINT8 */ 179 DMU_OT_SPA_HISTORY_OFFSETS, /* spa_his_phys_t */ 180 DMU_OT_POOL_PROPS, /* ZAP */ 181 DMU_OT_DSL_PERMS, /* ZAP */ 182 DMU_OT_ACL, /* ACL */ 183 DMU_OT_SYSACL, /* SYSACL */ 184 DMU_OT_FUID, /* FUID table (Packed NVLIST UINT8) */ 185 DMU_OT_FUID_SIZE, /* FUID table size UINT64 */ 186 DMU_OT_NEXT_CLONES, /* ZAP */ 187 DMU_OT_SCAN_QUEUE, /* ZAP */ 188 DMU_OT_USERGROUP_USED, /* ZAP */ 189 DMU_OT_USERGROUP_QUOTA, /* ZAP */ 190 DMU_OT_USERREFS, /* ZAP */ 191 DMU_OT_DDT_ZAP, /* ZAP */ 192 DMU_OT_DDT_STATS, /* ZAP */ 193 DMU_OT_SA, /* System attr */ 194 DMU_OT_SA_MASTER_NODE, /* ZAP */ 195 DMU_OT_SA_ATTR_REGISTRATION, /* ZAP */ 196 DMU_OT_SA_ATTR_LAYOUTS, /* ZAP */ 197 DMU_OT_SCAN_XLATE, /* ZAP */ 198 DMU_OT_DEDUP, /* fake dedup BP from ddt_bp_create() */ 199 DMU_OT_DEADLIST, /* ZAP */ 200 DMU_OT_DEADLIST_HDR, /* UINT64 */ 201 DMU_OT_DSL_CLONES, /* ZAP */ 202 DMU_OT_BPOBJ_SUBOBJ, /* UINT64 */ 203 /* 204 * Do not allocate new object types here. Doing so makes the on-disk 205 * format incompatible with any other format that uses the same object 206 * type number. 207 * 208 * When creating an object which does not have one of the above types 209 * use the DMU_OTN_* type with the correct byteswap and metadata 210 * values. 211 * 212 * The DMU_OTN_* types do not have entries in the dmu_ot table, 213 * use the DMU_OT_IS_METDATA() and DMU_OT_BYTESWAP() macros instead 214 * of indexing into dmu_ot directly (this works for both DMU_OT_* types 215 * and DMU_OTN_* types). 216 */ 217 DMU_OT_NUMTYPES, 218 219 /* 220 * Names for valid types declared with DMU_OT(). 221 */ 222 DMU_OTN_UINT8_DATA = DMU_OT(DMU_BSWAP_UINT8, B_FALSE), 223 DMU_OTN_UINT8_METADATA = DMU_OT(DMU_BSWAP_UINT8, B_TRUE), 224 DMU_OTN_UINT16_DATA = DMU_OT(DMU_BSWAP_UINT16, B_FALSE), 225 DMU_OTN_UINT16_METADATA = DMU_OT(DMU_BSWAP_UINT16, B_TRUE), 226 DMU_OTN_UINT32_DATA = DMU_OT(DMU_BSWAP_UINT32, B_FALSE), 227 DMU_OTN_UINT32_METADATA = DMU_OT(DMU_BSWAP_UINT32, B_TRUE), 228 DMU_OTN_UINT64_DATA = DMU_OT(DMU_BSWAP_UINT64, B_FALSE), 229 DMU_OTN_UINT64_METADATA = DMU_OT(DMU_BSWAP_UINT64, B_TRUE), 230 DMU_OTN_ZAP_DATA = DMU_OT(DMU_BSWAP_ZAP, B_FALSE), 231 DMU_OTN_ZAP_METADATA = DMU_OT(DMU_BSWAP_ZAP, B_TRUE), 232 } dmu_object_type_t; 233 234 typedef enum txg_how { 235 TXG_WAIT = 1, 236 TXG_NOWAIT, 237 TXG_WAITED, 238 } txg_how_t; 239 240 void byteswap_uint64_array(void *buf, size_t size); 241 void byteswap_uint32_array(void *buf, size_t size); 242 void byteswap_uint16_array(void *buf, size_t size); 243 void byteswap_uint8_array(void *buf, size_t size); 244 void zap_byteswap(void *buf, size_t size); 245 void zfs_oldacl_byteswap(void *buf, size_t size); 246 void zfs_acl_byteswap(void *buf, size_t size); 247 void zfs_znode_byteswap(void *buf, size_t size); 248 249 #define DS_FIND_SNAPSHOTS (1<<0) 250 #define DS_FIND_CHILDREN (1<<1) 251 #define DS_FIND_SERIALIZE (1<<2) 252 253 /* 254 * The maximum number of bytes that can be accessed as part of one 255 * operation, including metadata. 256 */ 257 #define DMU_MAX_ACCESS (32 * 1024 * 1024) /* 32MB */ 258 #define DMU_MAX_DELETEBLKCNT (20480) /* ~5MB of indirect blocks */ 259 260 #define DMU_USERUSED_OBJECT (-1ULL) 261 #define DMU_GROUPUSED_OBJECT (-2ULL) 262 263 /* 264 * artificial blkids for bonus buffer and spill blocks 265 */ 266 #define DMU_BONUS_BLKID (-1ULL) 267 #define DMU_SPILL_BLKID (-2ULL) 268 /* 269 * Public routines to create, destroy, open, and close objsets. 270 */ 271 int dmu_objset_hold(const char *name, void *tag, objset_t **osp); 272 int dmu_objset_own(const char *name, dmu_objset_type_t type, 273 boolean_t readonly, void *tag, objset_t **osp); 274 void dmu_objset_rele(objset_t *os, void *tag); 275 void dmu_objset_disown(objset_t *os, void *tag); 276 int dmu_objset_open_ds(struct dsl_dataset *ds, objset_t **osp); 277 278 void dmu_objset_evict_dbufs(objset_t *os); 279 int dmu_objset_create(const char *name, dmu_objset_type_t type, uint64_t flags, 280 void (*func)(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx), void *arg); 281 int dmu_objset_clone(const char *name, const char *origin); 282 int dsl_destroy_snapshots_nvl(struct nvlist *snaps, boolean_t defer, 283 struct nvlist *errlist); 284 int dmu_objset_snapshot_one(const char *fsname, const char *snapname); 285 int dmu_objset_snapshot_tmp(const char *, const char *, int); 286 int dmu_objset_find(char *name, int func(const char *, void *), void *arg, 287 int flags); 288 void dmu_objset_byteswap(void *buf, size_t size); 289 int dsl_dataset_rename_snapshot(const char *fsname, 290 const char *oldsnapname, const char *newsnapname, boolean_t recursive); 291 int dmu_objset_remap_indirects(const char *fsname); 292 293 typedef struct dmu_buf { 294 uint64_t db_object; /* object that this buffer is part of */ 295 uint64_t db_offset; /* byte offset in this object */ 296 uint64_t db_size; /* size of buffer in bytes */ 297 void *db_data; /* data in buffer */ 298 } dmu_buf_t; 299 300 /* 301 * The names of zap entries in the DIRECTORY_OBJECT of the MOS. 302 */ 303 #define DMU_POOL_DIRECTORY_OBJECT 1 304 #define DMU_POOL_CONFIG "config" 305 #define DMU_POOL_FEATURES_FOR_WRITE "features_for_write" 306 #define DMU_POOL_FEATURES_FOR_READ "features_for_read" 307 #define DMU_POOL_FEATURE_DESCRIPTIONS "feature_descriptions" 308 #define DMU_POOL_FEATURE_ENABLED_TXG "feature_enabled_txg" 309 #define DMU_POOL_ROOT_DATASET "root_dataset" 310 #define DMU_POOL_SYNC_BPOBJ "sync_bplist" 311 #define DMU_POOL_ERRLOG_SCRUB "errlog_scrub" 312 #define DMU_POOL_ERRLOG_LAST "errlog_last" 313 #define DMU_POOL_SPARES "spares" 314 #define DMU_POOL_DEFLATE "deflate" 315 #define DMU_POOL_HISTORY "history" 316 #define DMU_POOL_PROPS "pool_props" 317 #define DMU_POOL_L2CACHE "l2cache" 318 #define DMU_POOL_TMP_USERREFS "tmp_userrefs" 319 #define DMU_POOL_DDT "DDT-%s-%s-%s" 320 #define DMU_POOL_DDT_STATS "DDT-statistics" 321 #define DMU_POOL_CREATION_VERSION "creation_version" 322 #define DMU_POOL_SCAN "scan" 323 #define DMU_POOL_FREE_BPOBJ "free_bpobj" 324 #define DMU_POOL_BPTREE_OBJ "bptree_obj" 325 #define DMU_POOL_EMPTY_BPOBJ "empty_bpobj" 326 #define DMU_POOL_CHECKSUM_SALT "org.illumos:checksum_salt" 327 #define DMU_POOL_VDEV_ZAP_MAP "com.delphix:vdev_zap_map" 328 #define DMU_POOL_REMOVING "com.delphix:removing" 329 #define DMU_POOL_OBSOLETE_BPOBJ "com.delphix:obsolete_bpobj" 330 #define DMU_POOL_CONDENSING_INDIRECT "com.delphix:condensing_indirect" 331 332 /* 333 * Allocate an object from this objset. The range of object numbers 334 * available is (0, DN_MAX_OBJECT). Object 0 is the meta-dnode. 335 * 336 * The transaction must be assigned to a txg. The newly allocated 337 * object will be "held" in the transaction (ie. you can modify the 338 * newly allocated object in this transaction). 339 * 340 * dmu_object_alloc() chooses an object and returns it in *objectp. 341 * 342 * dmu_object_claim() allocates a specific object number. If that 343 * number is already allocated, it fails and returns EEXIST. 344 * 345 * Return 0 on success, or ENOSPC or EEXIST as specified above. 346 */ 347 uint64_t dmu_object_alloc(objset_t *os, dmu_object_type_t ot, 348 int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx); 349 int dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot, 350 int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx); 351 int dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot, 352 int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *txp); 353 354 /* 355 * Free an object from this objset. 356 * 357 * The object's data will be freed as well (ie. you don't need to call 358 * dmu_free(object, 0, -1, tx)). 359 * 360 * The object need not be held in the transaction. 361 * 362 * If there are any holds on this object's buffers (via dmu_buf_hold()), 363 * or tx holds on the object (via dmu_tx_hold_object()), you can not 364 * free it; it fails and returns EBUSY. 365 * 366 * If the object is not allocated, it fails and returns ENOENT. 367 * 368 * Return 0 on success, or EBUSY or ENOENT as specified above. 369 */ 370 int dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx); 371 372 /* 373 * Find the next allocated or free object. 374 * 375 * The objectp parameter is in-out. It will be updated to be the next 376 * object which is allocated. Ignore objects which have not been 377 * modified since txg. 378 * 379 * XXX Can only be called on a objset with no dirty data. 380 * 381 * Returns 0 on success, or ENOENT if there are no more objects. 382 */ 383 int dmu_object_next(objset_t *os, uint64_t *objectp, 384 boolean_t hole, uint64_t txg); 385 386 /* 387 * Set the data blocksize for an object. 388 * 389 * The object cannot have any blocks allcated beyond the first. If 390 * the first block is allocated already, the new size must be greater 391 * than the current block size. If these conditions are not met, 392 * ENOTSUP will be returned. 393 * 394 * Returns 0 on success, or EBUSY if there are any holds on the object 395 * contents, or ENOTSUP as described above. 396 */ 397 int dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size, 398 int ibs, dmu_tx_t *tx); 399 400 /* 401 * Set the checksum property on a dnode. The new checksum algorithm will 402 * apply to all newly written blocks; existing blocks will not be affected. 403 */ 404 void dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum, 405 dmu_tx_t *tx); 406 407 /* 408 * Set the compress property on a dnode. The new compression algorithm will 409 * apply to all newly written blocks; existing blocks will not be affected. 410 */ 411 void dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress, 412 dmu_tx_t *tx); 413 414 int dmu_object_remap_indirects(objset_t *os, uint64_t object, uint64_t txg); 415 416 void 417 dmu_write_embedded(objset_t *os, uint64_t object, uint64_t offset, 418 void *data, uint8_t etype, uint8_t comp, int uncompressed_size, 419 int compressed_size, int byteorder, dmu_tx_t *tx); 420 421 /* 422 * Decide how to write a block: checksum, compression, number of copies, etc. 423 */ 424 #define WP_NOFILL 0x1 425 #define WP_DMU_SYNC 0x2 426 #define WP_SPILL 0x4 427 428 void dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp, 429 struct zio_prop *zp); 430 /* 431 * The bonus data is accessed more or less like a regular buffer. 432 * You must dmu_bonus_hold() to get the buffer, which will give you a 433 * dmu_buf_t with db_offset==-1ULL, and db_size = the size of the bonus 434 * data. As with any normal buffer, you must call dmu_buf_will_dirty() 435 * before modifying it, and the 436 * object must be held in an assigned transaction before calling 437 * dmu_buf_will_dirty. You may use dmu_buf_set_user() on the bonus 438 * buffer as well. You must release your hold with dmu_buf_rele(). 439 * 440 * Returns ENOENT, EIO, or 0. 441 */ 442 int dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **); 443 int dmu_bonus_max(void); 444 int dmu_set_bonus(dmu_buf_t *, int, dmu_tx_t *); 445 int dmu_set_bonustype(dmu_buf_t *, dmu_object_type_t, dmu_tx_t *); 446 dmu_object_type_t dmu_get_bonustype(dmu_buf_t *); 447 int dmu_rm_spill(objset_t *, uint64_t, dmu_tx_t *); 448 449 /* 450 * Special spill buffer support used by "SA" framework 451 */ 452 453 int dmu_spill_hold_by_bonus(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp); 454 int dmu_spill_hold_by_dnode(dnode_t *dn, uint32_t flags, 455 void *tag, dmu_buf_t **dbp); 456 int dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp); 457 458 /* 459 * Obtain the DMU buffer from the specified object which contains the 460 * specified offset. dmu_buf_hold() puts a "hold" on the buffer, so 461 * that it will remain in memory. You must release the hold with 462 * dmu_buf_rele(). You musn't access the dmu_buf_t after releasing your 463 * hold. You must have a hold on any dmu_buf_t* you pass to the DMU. 464 * 465 * You must call dmu_buf_read, dmu_buf_will_dirty, or dmu_buf_will_fill 466 * on the returned buffer before reading or writing the buffer's 467 * db_data. The comments for those routines describe what particular 468 * operations are valid after calling them. 469 * 470 * The object number must be a valid, allocated object number. 471 */ 472 int dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset, 473 void *tag, dmu_buf_t **, int flags); 474 int dmu_buf_hold_by_dnode(dnode_t *dn, uint64_t offset, 475 void *tag, dmu_buf_t **dbp, int flags); 476 477 /* 478 * Add a reference to a dmu buffer that has already been held via 479 * dmu_buf_hold() in the current context. 480 */ 481 void dmu_buf_add_ref(dmu_buf_t *db, void* tag); 482 483 /* 484 * Attempt to add a reference to a dmu buffer that is in an unknown state, 485 * using a pointer that may have been invalidated by eviction processing. 486 * The request will succeed if the passed in dbuf still represents the 487 * same os/object/blkid, is ineligible for eviction, and has at least 488 * one hold by a user other than the syncer. 489 */ 490 boolean_t dmu_buf_try_add_ref(dmu_buf_t *, objset_t *os, uint64_t object, 491 uint64_t blkid, void *tag); 492 493 void dmu_buf_rele(dmu_buf_t *db, void *tag); 494 uint64_t dmu_buf_refcount(dmu_buf_t *db); 495 496 /* 497 * dmu_buf_hold_array holds the DMU buffers which contain all bytes in a 498 * range of an object. A pointer to an array of dmu_buf_t*'s is 499 * returned (in *dbpp). 500 * 501 * dmu_buf_rele_array releases the hold on an array of dmu_buf_t*'s, and 502 * frees the array. The hold on the array of buffers MUST be released 503 * with dmu_buf_rele_array. You can NOT release the hold on each buffer 504 * individually with dmu_buf_rele. 505 */ 506 int dmu_buf_hold_array_by_bonus(dmu_buf_t *db, uint64_t offset, 507 uint64_t length, boolean_t read, void *tag, 508 int *numbufsp, dmu_buf_t ***dbpp); 509 void dmu_buf_rele_array(dmu_buf_t **, int numbufs, void *tag); 510 511 typedef void dmu_buf_evict_func_t(void *user_ptr); 512 513 /* 514 * A DMU buffer user object may be associated with a dbuf for the 515 * duration of its lifetime. This allows the user of a dbuf (client) 516 * to attach private data to a dbuf (e.g. in-core only data such as a 517 * dnode_children_t, zap_t, or zap_leaf_t) and be optionally notified 518 * when that dbuf has been evicted. Clients typically respond to the 519 * eviction notification by freeing their private data, thus ensuring 520 * the same lifetime for both dbuf and private data. 521 * 522 * The mapping from a dmu_buf_user_t to any client private data is the 523 * client's responsibility. All current consumers of the API with private 524 * data embed a dmu_buf_user_t as the first member of the structure for 525 * their private data. This allows conversions between the two types 526 * with a simple cast. Since the DMU buf user API never needs access 527 * to the private data, other strategies can be employed if necessary 528 * or convenient for the client (e.g. using container_of() to do the 529 * conversion for private data that cannot have the dmu_buf_user_t as 530 * its first member). 531 * 532 * Eviction callbacks are executed without the dbuf mutex held or any 533 * other type of mechanism to guarantee that the dbuf is still available. 534 * For this reason, users must assume the dbuf has already been freed 535 * and not reference the dbuf from the callback context. 536 * 537 * Users requesting "immediate eviction" are notified as soon as the dbuf 538 * is only referenced by dirty records (dirties == holds). Otherwise the 539 * notification occurs after eviction processing for the dbuf begins. 540 */ 541 typedef struct dmu_buf_user { 542 /* 543 * Asynchronous user eviction callback state. 544 */ 545 taskq_ent_t dbu_tqent; 546 547 /* 548 * This instance's eviction function pointers. 549 * 550 * dbu_evict_func_sync is called synchronously and then 551 * dbu_evict_func_async is executed asynchronously on a taskq. 552 */ 553 dmu_buf_evict_func_t *dbu_evict_func_sync; 554 dmu_buf_evict_func_t *dbu_evict_func_async; 555 #ifdef ZFS_DEBUG 556 /* 557 * Pointer to user's dbuf pointer. NULL for clients that do 558 * not associate a dbuf with their user data. 559 * 560 * The dbuf pointer is cleared upon eviction so as to catch 561 * use-after-evict bugs in clients. 562 */ 563 dmu_buf_t **dbu_clear_on_evict_dbufp; 564 #endif 565 } dmu_buf_user_t; 566 567 /* 568 * Initialize the given dmu_buf_user_t instance with the eviction function 569 * evict_func, to be called when the user is evicted. 570 * 571 * NOTE: This function should only be called once on a given dmu_buf_user_t. 572 * To allow enforcement of this, dbu must already be zeroed on entry. 573 */ 574 /*ARGSUSED*/ 575 inline void 576 dmu_buf_init_user(dmu_buf_user_t *dbu, dmu_buf_evict_func_t *evict_func_sync, 577 dmu_buf_evict_func_t *evict_func_async, dmu_buf_t **clear_on_evict_dbufp) 578 { 579 ASSERT(dbu->dbu_evict_func_sync == NULL); 580 ASSERT(dbu->dbu_evict_func_async == NULL); 581 582 /* must have at least one evict func */ 583 IMPLY(evict_func_sync == NULL, evict_func_async != NULL); 584 dbu->dbu_evict_func_sync = evict_func_sync; 585 dbu->dbu_evict_func_async = evict_func_async; 586 #ifdef ZFS_DEBUG 587 dbu->dbu_clear_on_evict_dbufp = clear_on_evict_dbufp; 588 #endif 589 } 590 591 /* 592 * Attach user data to a dbuf and mark it for normal (when the dbuf's 593 * data is cleared or its reference count goes to zero) eviction processing. 594 * 595 * Returns NULL on success, or the existing user if another user currently 596 * owns the buffer. 597 */ 598 void *dmu_buf_set_user(dmu_buf_t *db, dmu_buf_user_t *user); 599 600 /* 601 * Attach user data to a dbuf and mark it for immediate (its dirty and 602 * reference counts are equal) eviction processing. 603 * 604 * Returns NULL on success, or the existing user if another user currently 605 * owns the buffer. 606 */ 607 void *dmu_buf_set_user_ie(dmu_buf_t *db, dmu_buf_user_t *user); 608 609 /* 610 * Replace the current user of a dbuf. 611 * 612 * If given the current user of a dbuf, replaces the dbuf's user with 613 * "new_user" and returns the user data pointer that was replaced. 614 * Otherwise returns the current, and unmodified, dbuf user pointer. 615 */ 616 void *dmu_buf_replace_user(dmu_buf_t *db, 617 dmu_buf_user_t *old_user, dmu_buf_user_t *new_user); 618 619 /* 620 * Remove the specified user data for a DMU buffer. 621 * 622 * Returns the user that was removed on success, or the current user if 623 * another user currently owns the buffer. 624 */ 625 void *dmu_buf_remove_user(dmu_buf_t *db, dmu_buf_user_t *user); 626 627 /* 628 * Returns the user data (dmu_buf_user_t *) associated with this dbuf. 629 */ 630 void *dmu_buf_get_user(dmu_buf_t *db); 631 632 objset_t *dmu_buf_get_objset(dmu_buf_t *db); 633 dnode_t *dmu_buf_dnode_enter(dmu_buf_t *db); 634 void dmu_buf_dnode_exit(dmu_buf_t *db); 635 636 /* Block until any in-progress dmu buf user evictions complete. */ 637 void dmu_buf_user_evict_wait(void); 638 639 /* 640 * Returns the blkptr associated with this dbuf, or NULL if not set. 641 */ 642 struct blkptr *dmu_buf_get_blkptr(dmu_buf_t *db); 643 644 /* 645 * Indicate that you are going to modify the buffer's data (db_data). 646 * 647 * The transaction (tx) must be assigned to a txg (ie. you've called 648 * dmu_tx_assign()). The buffer's object must be held in the tx 649 * (ie. you've called dmu_tx_hold_object(tx, db->db_object)). 650 */ 651 void dmu_buf_will_dirty(dmu_buf_t *db, dmu_tx_t *tx); 652 653 /* 654 * You must create a transaction, then hold the objects which you will 655 * (or might) modify as part of this transaction. Then you must assign 656 * the transaction to a transaction group. Once the transaction has 657 * been assigned, you can modify buffers which belong to held objects as 658 * part of this transaction. You can't modify buffers before the 659 * transaction has been assigned; you can't modify buffers which don't 660 * belong to objects which this transaction holds; you can't hold 661 * objects once the transaction has been assigned. You may hold an 662 * object which you are going to free (with dmu_object_free()), but you 663 * don't have to. 664 * 665 * You can abort the transaction before it has been assigned. 666 * 667 * Note that you may hold buffers (with dmu_buf_hold) at any time, 668 * regardless of transaction state. 669 */ 670 671 #define DMU_NEW_OBJECT (-1ULL) 672 #define DMU_OBJECT_END (-1ULL) 673 674 dmu_tx_t *dmu_tx_create(objset_t *os); 675 void dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len); 676 void dmu_tx_hold_write_by_dnode(dmu_tx_t *tx, dnode_t *dn, uint64_t off, 677 int len); 678 void dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off, 679 uint64_t len); 680 void dmu_tx_hold_free_by_dnode(dmu_tx_t *tx, dnode_t *dn, uint64_t off, 681 uint64_t len); 682 void dmu_tx_hold_remap_l1indirect(dmu_tx_t *tx, uint64_t object); 683 void dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name); 684 void dmu_tx_hold_zap_by_dnode(dmu_tx_t *tx, dnode_t *dn, int add, 685 const char *name); 686 void dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object); 687 void dmu_tx_hold_bonus_by_dnode(dmu_tx_t *tx, dnode_t *dn); 688 void dmu_tx_hold_spill(dmu_tx_t *tx, uint64_t object); 689 void dmu_tx_hold_sa(dmu_tx_t *tx, struct sa_handle *hdl, boolean_t may_grow); 690 void dmu_tx_hold_sa_create(dmu_tx_t *tx, int total_size); 691 void dmu_tx_abort(dmu_tx_t *tx); 692 int dmu_tx_assign(dmu_tx_t *tx, enum txg_how txg_how); 693 void dmu_tx_wait(dmu_tx_t *tx); 694 void dmu_tx_commit(dmu_tx_t *tx); 695 void dmu_tx_mark_netfree(dmu_tx_t *tx); 696 697 /* 698 * To register a commit callback, dmu_tx_callback_register() must be called. 699 * 700 * dcb_data is a pointer to caller private data that is passed on as a 701 * callback parameter. The caller is responsible for properly allocating and 702 * freeing it. 703 * 704 * When registering a callback, the transaction must be already created, but 705 * it cannot be committed or aborted. It can be assigned to a txg or not. 706 * 707 * The callback will be called after the transaction has been safely written 708 * to stable storage and will also be called if the dmu_tx is aborted. 709 * If there is any error which prevents the transaction from being committed to 710 * disk, the callback will be called with a value of error != 0. 711 */ 712 typedef void dmu_tx_callback_func_t(void *dcb_data, int error); 713 714 void dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *dcb_func, 715 void *dcb_data); 716 717 /* 718 * Free up the data blocks for a defined range of a file. If size is 719 * -1, the range from offset to end-of-file is freed. 720 */ 721 int dmu_free_range(objset_t *os, uint64_t object, uint64_t offset, 722 uint64_t size, dmu_tx_t *tx); 723 int dmu_free_long_range(objset_t *os, uint64_t object, uint64_t offset, 724 uint64_t size); 725 int dmu_free_long_object(objset_t *os, uint64_t object); 726 727 /* 728 * Convenience functions. 729 * 730 * Canfail routines will return 0 on success, or an errno if there is a 731 * nonrecoverable I/O error. 732 */ 733 #define DMU_READ_PREFETCH 0 /* prefetch */ 734 #define DMU_READ_NO_PREFETCH 1 /* don't prefetch */ 735 int dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 736 void *buf, uint32_t flags); 737 int dmu_read_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size, void *buf, 738 uint32_t flags); 739 void dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 740 const void *buf, dmu_tx_t *tx); 741 void dmu_write_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size, 742 const void *buf, dmu_tx_t *tx); 743 void dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 744 dmu_tx_t *tx); 745 int dmu_read_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size); 746 int dmu_read_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size); 747 int dmu_write_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size, 748 dmu_tx_t *tx); 749 int dmu_write_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size, 750 dmu_tx_t *tx); 751 int dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset, 752 uint64_t size, struct page *pp, dmu_tx_t *tx); 753 struct arc_buf *dmu_request_arcbuf(dmu_buf_t *handle, int size); 754 void dmu_return_arcbuf(struct arc_buf *buf); 755 void dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, struct arc_buf *buf, 756 dmu_tx_t *tx); 757 int dmu_xuio_init(struct xuio *uio, int niov); 758 void dmu_xuio_fini(struct xuio *uio); 759 int dmu_xuio_add(struct xuio *uio, struct arc_buf *abuf, offset_t off, 760 size_t n); 761 int dmu_xuio_cnt(struct xuio *uio); 762 struct arc_buf *dmu_xuio_arcbuf(struct xuio *uio, int i); 763 void dmu_xuio_clear(struct xuio *uio, int i); 764 void xuio_stat_wbuf_copied(void); 765 void xuio_stat_wbuf_nocopy(void); 766 767 extern boolean_t zfs_prefetch_disable; 768 extern int zfs_max_recordsize; 769 770 /* 771 * Asynchronously try to read in the data. 772 */ 773 void dmu_prefetch(objset_t *os, uint64_t object, int64_t level, uint64_t offset, 774 uint64_t len, enum zio_priority pri); 775 776 typedef struct dmu_object_info { 777 /* All sizes are in bytes unless otherwise indicated. */ 778 uint32_t doi_data_block_size; 779 uint32_t doi_metadata_block_size; 780 dmu_object_type_t doi_type; 781 dmu_object_type_t doi_bonus_type; 782 uint64_t doi_bonus_size; 783 uint8_t doi_indirection; /* 2 = dnode->indirect->data */ 784 uint8_t doi_checksum; 785 uint8_t doi_compress; 786 uint8_t doi_nblkptr; 787 uint8_t doi_pad[4]; 788 uint64_t doi_physical_blocks_512; /* data + metadata, 512b blks */ 789 uint64_t doi_max_offset; 790 uint64_t doi_fill_count; /* number of non-empty blocks */ 791 } dmu_object_info_t; 792 793 typedef void arc_byteswap_func_t(void *buf, size_t size); 794 795 typedef struct dmu_object_type_info { 796 dmu_object_byteswap_t ot_byteswap; 797 boolean_t ot_metadata; 798 char *ot_name; 799 } dmu_object_type_info_t; 800 801 typedef struct dmu_object_byteswap_info { 802 arc_byteswap_func_t *ob_func; 803 char *ob_name; 804 } dmu_object_byteswap_info_t; 805 806 extern const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES]; 807 extern const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS]; 808 809 /* 810 * Get information on a DMU object. 811 * 812 * Return 0 on success or ENOENT if object is not allocated. 813 * 814 * If doi is NULL, just indicates whether the object exists. 815 */ 816 int dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi); 817 /* Like dmu_object_info, but faster if you have a held dnode in hand. */ 818 void dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi); 819 /* Like dmu_object_info, but faster if you have a held dbuf in hand. */ 820 void dmu_object_info_from_db(dmu_buf_t *db, dmu_object_info_t *doi); 821 /* 822 * Like dmu_object_info_from_db, but faster still when you only care about 823 * the size. This is specifically optimized for zfs_getattr(). 824 */ 825 void dmu_object_size_from_db(dmu_buf_t *db, uint32_t *blksize, 826 u_longlong_t *nblk512); 827 828 typedef struct dmu_objset_stats { 829 uint64_t dds_num_clones; /* number of clones of this */ 830 uint64_t dds_creation_txg; 831 uint64_t dds_guid; 832 dmu_objset_type_t dds_type; 833 uint8_t dds_is_snapshot; 834 uint8_t dds_inconsistent; 835 char dds_origin[ZFS_MAX_DATASET_NAME_LEN]; 836 } dmu_objset_stats_t; 837 838 /* 839 * Get stats on a dataset. 840 */ 841 void dmu_objset_fast_stat(objset_t *os, dmu_objset_stats_t *stat); 842 843 /* 844 * Add entries to the nvlist for all the objset's properties. See 845 * zfs_prop_table[] and zfs(1m) for details on the properties. 846 */ 847 void dmu_objset_stats(objset_t *os, struct nvlist *nv); 848 849 /* 850 * Get the space usage statistics for statvfs(). 851 * 852 * refdbytes is the amount of space "referenced" by this objset. 853 * availbytes is the amount of space available to this objset, taking 854 * into account quotas & reservations, assuming that no other objsets 855 * use the space first. These values correspond to the 'referenced' and 856 * 'available' properties, described in the zfs(1m) manpage. 857 * 858 * usedobjs and availobjs are the number of objects currently allocated, 859 * and available. 860 */ 861 void dmu_objset_space(objset_t *os, uint64_t *refdbytesp, uint64_t *availbytesp, 862 uint64_t *usedobjsp, uint64_t *availobjsp); 863 864 /* 865 * The fsid_guid is a 56-bit ID that can change to avoid collisions. 866 * (Contrast with the ds_guid which is a 64-bit ID that will never 867 * change, so there is a small probability that it will collide.) 868 */ 869 uint64_t dmu_objset_fsid_guid(objset_t *os); 870 871 /* 872 * Get the [cm]time for an objset's snapshot dir 873 */ 874 timestruc_t dmu_objset_snap_cmtime(objset_t *os); 875 876 int dmu_objset_is_snapshot(objset_t *os); 877 878 extern struct spa *dmu_objset_spa(objset_t *os); 879 extern struct zilog *dmu_objset_zil(objset_t *os); 880 extern struct dsl_pool *dmu_objset_pool(objset_t *os); 881 extern struct dsl_dataset *dmu_objset_ds(objset_t *os); 882 extern void dmu_objset_name(objset_t *os, char *buf); 883 extern dmu_objset_type_t dmu_objset_type(objset_t *os); 884 extern uint64_t dmu_objset_id(objset_t *os); 885 extern zfs_sync_type_t dmu_objset_syncprop(objset_t *os); 886 extern zfs_logbias_op_t dmu_objset_logbias(objset_t *os); 887 extern int dmu_snapshot_list_next(objset_t *os, int namelen, char *name, 888 uint64_t *id, uint64_t *offp, boolean_t *case_conflict); 889 extern int dmu_snapshot_realname(objset_t *os, char *name, char *real, 890 int maxlen, boolean_t *conflict); 891 extern int dmu_dir_list_next(objset_t *os, int namelen, char *name, 892 uint64_t *idp, uint64_t *offp); 893 894 typedef int objset_used_cb_t(dmu_object_type_t bonustype, 895 void *bonus, uint64_t *userp, uint64_t *groupp); 896 extern void dmu_objset_register_type(dmu_objset_type_t ost, 897 objset_used_cb_t *cb); 898 extern void dmu_objset_set_user(objset_t *os, void *user_ptr); 899 extern void *dmu_objset_get_user(objset_t *os); 900 901 /* 902 * Return the txg number for the given assigned transaction. 903 */ 904 uint64_t dmu_tx_get_txg(dmu_tx_t *tx); 905 906 /* 907 * Synchronous write. 908 * If a parent zio is provided this function initiates a write on the 909 * provided buffer as a child of the parent zio. 910 * In the absence of a parent zio, the write is completed synchronously. 911 * At write completion, blk is filled with the bp of the written block. 912 * Note that while the data covered by this function will be on stable 913 * storage when the write completes this new data does not become a 914 * permanent part of the file until the associated transaction commits. 915 */ 916 917 /* 918 * {zfs,zvol,ztest}_get_done() args 919 */ 920 typedef struct zgd { 921 struct lwb *zgd_lwb; 922 struct blkptr *zgd_bp; 923 dmu_buf_t *zgd_db; 924 struct rl *zgd_rl; 925 void *zgd_private; 926 } zgd_t; 927 928 typedef void dmu_sync_cb_t(zgd_t *arg, int error); 929 int dmu_sync(struct zio *zio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd); 930 931 /* 932 * Find the next hole or data block in file starting at *off 933 * Return found offset in *off. Return ESRCH for end of file. 934 */ 935 int dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole, 936 uint64_t *off); 937 938 /* 939 * Check if a DMU object has any dirty blocks. If so, sync out 940 * all pending transaction groups. Otherwise, this function 941 * does not alter DMU state. This could be improved to only sync 942 * out the necessary transaction groups for this particular 943 * object. 944 */ 945 int dmu_object_wait_synced(objset_t *os, uint64_t object); 946 947 /* 948 * Initial setup and final teardown. 949 */ 950 extern void dmu_init(void); 951 extern void dmu_fini(void); 952 953 typedef void (*dmu_traverse_cb_t)(objset_t *os, void *arg, struct blkptr *bp, 954 uint64_t object, uint64_t offset, int len); 955 void dmu_traverse_objset(objset_t *os, uint64_t txg_start, 956 dmu_traverse_cb_t cb, void *arg); 957 958 int dmu_diff(const char *tosnap_name, const char *fromsnap_name, 959 struct vnode *vp, offset_t *offp); 960 961 /* CRC64 table */ 962 #define ZFS_CRC64_POLY 0xC96C5795D7870F42ULL /* ECMA-182, reflected form */ 963 extern uint64_t zfs_crc64_table[256]; 964 965 extern int zfs_mdcomp_disable; 966 967 #ifdef __cplusplus 968 } 969 #endif 970 971 #endif /* _SYS_DMU_H */ 972