dmu.h revision 297112
1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22/* 23 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 24 * Copyright (c) 2011, 2014 by Delphix. All rights reserved. 25 * Copyright 2011 Nexenta Systems, Inc. All rights reserved. 26 * Copyright (c) 2012, Joyent, Inc. All rights reserved. 27 * Copyright 2013 DEY Storage Systems, Inc. 28 * Copyright 2014 HybridCluster. All rights reserved. 29 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. 30 * Copyright 2013 Saso Kiselkov. All rights reserved. 31 * 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/cred.h> 49#include <sys/fs/zfs.h> 50#include <sys/zio_priority.h> 51 52#ifdef __cplusplus 53extern "C" { 54#endif 55 56struct uio; 57struct xuio; 58struct page; 59struct vnode; 60struct spa; 61struct zilog; 62struct zio; 63struct blkptr; 64struct zap_cursor; 65struct dsl_dataset; 66struct dsl_pool; 67struct dnode; 68struct drr_begin; 69struct drr_end; 70struct zbookmark_phys; 71struct spa; 72struct nvlist; 73struct arc_buf; 74struct zio_prop; 75struct sa_handle; 76struct file; 77 78typedef struct objset objset_t; 79typedef struct dmu_tx dmu_tx_t; 80typedef struct dsl_dir dsl_dir_t; 81 82typedef enum dmu_object_byteswap { 83 DMU_BSWAP_UINT8, 84 DMU_BSWAP_UINT16, 85 DMU_BSWAP_UINT32, 86 DMU_BSWAP_UINT64, 87 DMU_BSWAP_ZAP, 88 DMU_BSWAP_DNODE, 89 DMU_BSWAP_OBJSET, 90 DMU_BSWAP_ZNODE, 91 DMU_BSWAP_OLDACL, 92 DMU_BSWAP_ACL, 93 /* 94 * Allocating a new byteswap type number makes the on-disk format 95 * incompatible with any other format that uses the same number. 96 * 97 * Data can usually be structured to work with one of the 98 * DMU_BSWAP_UINT* or DMU_BSWAP_ZAP types. 99 */ 100 DMU_BSWAP_NUMFUNCS 101} dmu_object_byteswap_t; 102 103#define DMU_OT_NEWTYPE 0x80 104#define DMU_OT_METADATA 0x40 105#define DMU_OT_BYTESWAP_MASK 0x3f 106 107/* 108 * Defines a uint8_t object type. Object types specify if the data 109 * in the object is metadata (boolean) and how to byteswap the data 110 * (dmu_object_byteswap_t). 111 */ 112#define DMU_OT(byteswap, metadata) \ 113 (DMU_OT_NEWTYPE | \ 114 ((metadata) ? DMU_OT_METADATA : 0) | \ 115 ((byteswap) & DMU_OT_BYTESWAP_MASK)) 116 117#define DMU_OT_IS_VALID(ot) (((ot) & DMU_OT_NEWTYPE) ? \ 118 ((ot) & DMU_OT_BYTESWAP_MASK) < DMU_BSWAP_NUMFUNCS : \ 119 (ot) < DMU_OT_NUMTYPES) 120 121#define DMU_OT_IS_METADATA(ot) (((ot) & DMU_OT_NEWTYPE) ? \ 122 ((ot) & DMU_OT_METADATA) : \ 123 dmu_ot[(ot)].ot_metadata) 124 125/* 126 * These object types use bp_fill != 1 for their L0 bp's. Therefore they can't 127 * have their data embedded (i.e. use a BP_IS_EMBEDDED() bp), because bp_fill 128 * is repurposed for embedded BPs. 129 */ 130#define DMU_OT_HAS_FILL(ot) \ 131 ((ot) == DMU_OT_DNODE || (ot) == DMU_OT_OBJSET) 132 133#define DMU_OT_BYTESWAP(ot) (((ot) & DMU_OT_NEWTYPE) ? \ 134 ((ot) & DMU_OT_BYTESWAP_MASK) : \ 135 dmu_ot[(ot)].ot_byteswap) 136 137typedef enum dmu_object_type { 138 DMU_OT_NONE, 139 /* general: */ 140 DMU_OT_OBJECT_DIRECTORY, /* ZAP */ 141 DMU_OT_OBJECT_ARRAY, /* UINT64 */ 142 DMU_OT_PACKED_NVLIST, /* UINT8 (XDR by nvlist_pack/unpack) */ 143 DMU_OT_PACKED_NVLIST_SIZE, /* UINT64 */ 144 DMU_OT_BPOBJ, /* UINT64 */ 145 DMU_OT_BPOBJ_HDR, /* UINT64 */ 146 /* spa: */ 147 DMU_OT_SPACE_MAP_HEADER, /* UINT64 */ 148 DMU_OT_SPACE_MAP, /* UINT64 */ 149 /* zil: */ 150 DMU_OT_INTENT_LOG, /* UINT64 */ 151 /* dmu: */ 152 DMU_OT_DNODE, /* DNODE */ 153 DMU_OT_OBJSET, /* OBJSET */ 154 /* dsl: */ 155 DMU_OT_DSL_DIR, /* UINT64 */ 156 DMU_OT_DSL_DIR_CHILD_MAP, /* ZAP */ 157 DMU_OT_DSL_DS_SNAP_MAP, /* ZAP */ 158 DMU_OT_DSL_PROPS, /* ZAP */ 159 DMU_OT_DSL_DATASET, /* UINT64 */ 160 /* zpl: */ 161 DMU_OT_ZNODE, /* ZNODE */ 162 DMU_OT_OLDACL, /* Old ACL */ 163 DMU_OT_PLAIN_FILE_CONTENTS, /* UINT8 */ 164 DMU_OT_DIRECTORY_CONTENTS, /* ZAP */ 165 DMU_OT_MASTER_NODE, /* ZAP */ 166 DMU_OT_UNLINKED_SET, /* ZAP */ 167 /* zvol: */ 168 DMU_OT_ZVOL, /* UINT8 */ 169 DMU_OT_ZVOL_PROP, /* ZAP */ 170 /* other; for testing only! */ 171 DMU_OT_PLAIN_OTHER, /* UINT8 */ 172 DMU_OT_UINT64_OTHER, /* UINT64 */ 173 DMU_OT_ZAP_OTHER, /* ZAP */ 174 /* new object types: */ 175 DMU_OT_ERROR_LOG, /* ZAP */ 176 DMU_OT_SPA_HISTORY, /* UINT8 */ 177 DMU_OT_SPA_HISTORY_OFFSETS, /* spa_his_phys_t */ 178 DMU_OT_POOL_PROPS, /* ZAP */ 179 DMU_OT_DSL_PERMS, /* ZAP */ 180 DMU_OT_ACL, /* ACL */ 181 DMU_OT_SYSACL, /* SYSACL */ 182 DMU_OT_FUID, /* FUID table (Packed NVLIST UINT8) */ 183 DMU_OT_FUID_SIZE, /* FUID table size UINT64 */ 184 DMU_OT_NEXT_CLONES, /* ZAP */ 185 DMU_OT_SCAN_QUEUE, /* ZAP */ 186 DMU_OT_USERGROUP_USED, /* ZAP */ 187 DMU_OT_USERGROUP_QUOTA, /* ZAP */ 188 DMU_OT_USERREFS, /* ZAP */ 189 DMU_OT_DDT_ZAP, /* ZAP */ 190 DMU_OT_DDT_STATS, /* ZAP */ 191 DMU_OT_SA, /* System attr */ 192 DMU_OT_SA_MASTER_NODE, /* ZAP */ 193 DMU_OT_SA_ATTR_REGISTRATION, /* ZAP */ 194 DMU_OT_SA_ATTR_LAYOUTS, /* ZAP */ 195 DMU_OT_SCAN_XLATE, /* ZAP */ 196 DMU_OT_DEDUP, /* fake dedup BP from ddt_bp_create() */ 197 DMU_OT_DEADLIST, /* ZAP */ 198 DMU_OT_DEADLIST_HDR, /* UINT64 */ 199 DMU_OT_DSL_CLONES, /* ZAP */ 200 DMU_OT_BPOBJ_SUBOBJ, /* UINT64 */ 201 /* 202 * Do not allocate new object types here. Doing so makes the on-disk 203 * format incompatible with any other format that uses the same object 204 * type number. 205 * 206 * When creating an object which does not have one of the above types 207 * use the DMU_OTN_* type with the correct byteswap and metadata 208 * values. 209 * 210 * The DMU_OTN_* types do not have entries in the dmu_ot table, 211 * use the DMU_OT_IS_METDATA() and DMU_OT_BYTESWAP() macros instead 212 * of indexing into dmu_ot directly (this works for both DMU_OT_* types 213 * and DMU_OTN_* types). 214 */ 215 DMU_OT_NUMTYPES, 216 217 /* 218 * Names for valid types declared with DMU_OT(). 219 */ 220 DMU_OTN_UINT8_DATA = DMU_OT(DMU_BSWAP_UINT8, B_FALSE), 221 DMU_OTN_UINT8_METADATA = DMU_OT(DMU_BSWAP_UINT8, B_TRUE), 222 DMU_OTN_UINT16_DATA = DMU_OT(DMU_BSWAP_UINT16, B_FALSE), 223 DMU_OTN_UINT16_METADATA = DMU_OT(DMU_BSWAP_UINT16, B_TRUE), 224 DMU_OTN_UINT32_DATA = DMU_OT(DMU_BSWAP_UINT32, B_FALSE), 225 DMU_OTN_UINT32_METADATA = DMU_OT(DMU_BSWAP_UINT32, B_TRUE), 226 DMU_OTN_UINT64_DATA = DMU_OT(DMU_BSWAP_UINT64, B_FALSE), 227 DMU_OTN_UINT64_METADATA = DMU_OT(DMU_BSWAP_UINT64, B_TRUE), 228 DMU_OTN_ZAP_DATA = DMU_OT(DMU_BSWAP_ZAP, B_FALSE), 229 DMU_OTN_ZAP_METADATA = DMU_OT(DMU_BSWAP_ZAP, B_TRUE), 230} dmu_object_type_t; 231 232typedef enum txg_how { 233 TXG_WAIT = 1, 234 TXG_NOWAIT, 235 TXG_WAITED, 236} txg_how_t; 237 238void byteswap_uint64_array(void *buf, size_t size); 239void byteswap_uint32_array(void *buf, size_t size); 240void byteswap_uint16_array(void *buf, size_t size); 241void byteswap_uint8_array(void *buf, size_t size); 242void zap_byteswap(void *buf, size_t size); 243void zfs_oldacl_byteswap(void *buf, size_t size); 244void zfs_acl_byteswap(void *buf, size_t size); 245void zfs_znode_byteswap(void *buf, size_t size); 246 247#define DS_FIND_SNAPSHOTS (1<<0) 248#define DS_FIND_CHILDREN (1<<1) 249#define DS_FIND_SERIALIZE (1<<2) 250 251/* 252 * The maximum number of bytes that can be accessed as part of one 253 * operation, including metadata. 254 */ 255#define DMU_MAX_ACCESS (32 * 1024 * 1024) /* 32MB */ 256#define DMU_MAX_DELETEBLKCNT (20480) /* ~5MB of indirect blocks */ 257 258#define DMU_USERUSED_OBJECT (-1ULL) 259#define DMU_GROUPUSED_OBJECT (-2ULL) 260 261/* 262 * artificial blkids for bonus buffer and spill blocks 263 */ 264#define DMU_BONUS_BLKID (-1ULL) 265#define DMU_SPILL_BLKID (-2ULL) 266/* 267 * Public routines to create, destroy, open, and close objsets. 268 */ 269int dmu_objset_hold(const char *name, void *tag, objset_t **osp); 270int dmu_objset_own(const char *name, dmu_objset_type_t type, 271 boolean_t readonly, void *tag, objset_t **osp); 272void dmu_objset_rele(objset_t *os, void *tag); 273void dmu_objset_disown(objset_t *os, void *tag); 274int dmu_objset_open_ds(struct dsl_dataset *ds, objset_t **osp); 275 276void dmu_objset_evict_dbufs(objset_t *os); 277int dmu_objset_create(const char *name, dmu_objset_type_t type, uint64_t flags, 278 void (*func)(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx), void *arg); 279int dmu_get_recursive_snaps_nvl(char *fsname, const char *snapname, 280 struct nvlist *snaps); 281int dmu_objset_clone(const char *name, const char *origin); 282int dsl_destroy_snapshots_nvl(struct nvlist *snaps, boolean_t defer, 283 struct nvlist *errlist); 284int dmu_objset_snapshot_one(const char *fsname, const char *snapname); 285int dmu_objset_snapshot_tmp(const char *, const char *, int); 286int dmu_objset_find(char *name, int func(const char *, void *), void *arg, 287 int flags); 288void dmu_objset_byteswap(void *buf, size_t size); 289int dsl_dataset_rename_snapshot(const char *fsname, 290 const char *oldsnapname, const char *newsnapname, boolean_t recursive); 291 292typedef struct dmu_buf { 293 uint64_t db_object; /* object that this buffer is part of */ 294 uint64_t db_offset; /* byte offset in this object */ 295 uint64_t db_size; /* size of buffer in bytes */ 296 void *db_data; /* data in buffer */ 297} dmu_buf_t; 298 299/* 300 * The names of zap entries in the DIRECTORY_OBJECT of the MOS. 301 */ 302#define DMU_POOL_DIRECTORY_OBJECT 1 303#define DMU_POOL_CONFIG "config" 304#define DMU_POOL_FEATURES_FOR_WRITE "features_for_write" 305#define DMU_POOL_FEATURES_FOR_READ "features_for_read" 306#define DMU_POOL_FEATURE_DESCRIPTIONS "feature_descriptions" 307#define DMU_POOL_FEATURE_ENABLED_TXG "feature_enabled_txg" 308#define DMU_POOL_ROOT_DATASET "root_dataset" 309#define DMU_POOL_SYNC_BPOBJ "sync_bplist" 310#define DMU_POOL_ERRLOG_SCRUB "errlog_scrub" 311#define DMU_POOL_ERRLOG_LAST "errlog_last" 312#define DMU_POOL_SPARES "spares" 313#define DMU_POOL_DEFLATE "deflate" 314#define DMU_POOL_HISTORY "history" 315#define DMU_POOL_PROPS "pool_props" 316#define DMU_POOL_L2CACHE "l2cache" 317#define DMU_POOL_TMP_USERREFS "tmp_userrefs" 318#define DMU_POOL_DDT "DDT-%s-%s-%s" 319#define DMU_POOL_DDT_STATS "DDT-statistics" 320#define DMU_POOL_CREATION_VERSION "creation_version" 321#define DMU_POOL_SCAN "scan" 322#define DMU_POOL_FREE_BPOBJ "free_bpobj" 323#define DMU_POOL_BPTREE_OBJ "bptree_obj" 324#define DMU_POOL_EMPTY_BPOBJ "empty_bpobj" 325#define DMU_POOL_CHECKSUM_SALT "org.illumos:checksum_salt" 326 327/* 328 * Allocate an object from this objset. The range of object numbers 329 * available is (0, DN_MAX_OBJECT). Object 0 is the meta-dnode. 330 * 331 * The transaction must be assigned to a txg. The newly allocated 332 * object will be "held" in the transaction (ie. you can modify the 333 * newly allocated object in this transaction). 334 * 335 * dmu_object_alloc() chooses an object and returns it in *objectp. 336 * 337 * dmu_object_claim() allocates a specific object number. If that 338 * number is already allocated, it fails and returns EEXIST. 339 * 340 * Return 0 on success, or ENOSPC or EEXIST as specified above. 341 */ 342uint64_t dmu_object_alloc(objset_t *os, dmu_object_type_t ot, 343 int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx); 344int dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot, 345 int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx); 346int dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot, 347 int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *txp); 348 349/* 350 * Free an object from this objset. 351 * 352 * The object's data will be freed as well (ie. you don't need to call 353 * dmu_free(object, 0, -1, tx)). 354 * 355 * The object need not be held in the transaction. 356 * 357 * If there are any holds on this object's buffers (via dmu_buf_hold()), 358 * or tx holds on the object (via dmu_tx_hold_object()), you can not 359 * free it; it fails and returns EBUSY. 360 * 361 * If the object is not allocated, it fails and returns ENOENT. 362 * 363 * Return 0 on success, or EBUSY or ENOENT as specified above. 364 */ 365int dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx); 366 367/* 368 * Find the next allocated or free object. 369 * 370 * The objectp parameter is in-out. It will be updated to be the next 371 * object which is allocated. Ignore objects which have not been 372 * modified since txg. 373 * 374 * XXX Can only be called on a objset with no dirty data. 375 * 376 * Returns 0 on success, or ENOENT if there are no more objects. 377 */ 378int dmu_object_next(objset_t *os, uint64_t *objectp, 379 boolean_t hole, uint64_t txg); 380 381/* 382 * Set the data blocksize for an object. 383 * 384 * The object cannot have any blocks allcated beyond the first. If 385 * the first block is allocated already, the new size must be greater 386 * than the current block size. If these conditions are not met, 387 * ENOTSUP will be returned. 388 * 389 * Returns 0 on success, or EBUSY if there are any holds on the object 390 * contents, or ENOTSUP as described above. 391 */ 392int dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size, 393 int ibs, dmu_tx_t *tx); 394 395/* 396 * Set the checksum property on a dnode. The new checksum algorithm will 397 * apply to all newly written blocks; existing blocks will not be affected. 398 */ 399void dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum, 400 dmu_tx_t *tx); 401 402/* 403 * Set the compress property on a dnode. The new compression algorithm will 404 * apply to all newly written blocks; existing blocks will not be affected. 405 */ 406void dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress, 407 dmu_tx_t *tx); 408 409void 410dmu_write_embedded(objset_t *os, uint64_t object, uint64_t offset, 411 void *data, uint8_t etype, uint8_t comp, int uncompressed_size, 412 int compressed_size, int byteorder, dmu_tx_t *tx); 413 414/* 415 * Decide how to write a block: checksum, compression, number of copies, etc. 416 */ 417#define WP_NOFILL 0x1 418#define WP_DMU_SYNC 0x2 419#define WP_SPILL 0x4 420 421void dmu_write_policy(objset_t *os, struct dnode *dn, int level, int wp, 422 struct zio_prop *zp); 423/* 424 * The bonus data is accessed more or less like a regular buffer. 425 * You must dmu_bonus_hold() to get the buffer, which will give you a 426 * dmu_buf_t with db_offset==-1ULL, and db_size = the size of the bonus 427 * data. As with any normal buffer, you must call dmu_buf_read() to 428 * read db_data, dmu_buf_will_dirty() before modifying it, and the 429 * object must be held in an assigned transaction before calling 430 * dmu_buf_will_dirty. You may use dmu_buf_set_user() on the bonus 431 * buffer as well. You must release your hold with dmu_buf_rele(). 432 * 433 * Returns ENOENT, EIO, or 0. 434 */ 435int dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **); 436int dmu_bonus_max(void); 437int dmu_set_bonus(dmu_buf_t *, int, dmu_tx_t *); 438int dmu_set_bonustype(dmu_buf_t *, dmu_object_type_t, dmu_tx_t *); 439dmu_object_type_t dmu_get_bonustype(dmu_buf_t *); 440int dmu_rm_spill(objset_t *, uint64_t, dmu_tx_t *); 441 442/* 443 * Special spill buffer support used by "SA" framework 444 */ 445 446int dmu_spill_hold_by_bonus(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp); 447int dmu_spill_hold_by_dnode(struct dnode *dn, uint32_t flags, 448 void *tag, dmu_buf_t **dbp); 449int dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp); 450 451/* 452 * Obtain the DMU buffer from the specified object which contains the 453 * specified offset. dmu_buf_hold() puts a "hold" on the buffer, so 454 * that it will remain in memory. You must release the hold with 455 * dmu_buf_rele(). You musn't access the dmu_buf_t after releasing your 456 * hold. You must have a hold on any dmu_buf_t* you pass to the DMU. 457 * 458 * You must call dmu_buf_read, dmu_buf_will_dirty, or dmu_buf_will_fill 459 * on the returned buffer before reading or writing the buffer's 460 * db_data. The comments for those routines describe what particular 461 * operations are valid after calling them. 462 * 463 * The object number must be a valid, allocated object number. 464 */ 465int dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset, 466 void *tag, dmu_buf_t **, int flags); 467 468/* 469 * Add a reference to a dmu buffer that has already been held via 470 * dmu_buf_hold() in the current context. 471 */ 472void dmu_buf_add_ref(dmu_buf_t *db, void* tag); 473 474/* 475 * Attempt to add a reference to a dmu buffer that is in an unknown state, 476 * using a pointer that may have been invalidated by eviction processing. 477 * The request will succeed if the passed in dbuf still represents the 478 * same os/object/blkid, is ineligible for eviction, and has at least 479 * one hold by a user other than the syncer. 480 */ 481boolean_t dmu_buf_try_add_ref(dmu_buf_t *, objset_t *os, uint64_t object, 482 uint64_t blkid, void *tag); 483 484void dmu_buf_rele(dmu_buf_t *db, void *tag); 485uint64_t dmu_buf_refcount(dmu_buf_t *db); 486 487/* 488 * dmu_buf_hold_array holds the DMU buffers which contain all bytes in a 489 * range of an object. A pointer to an array of dmu_buf_t*'s is 490 * returned (in *dbpp). 491 * 492 * dmu_buf_rele_array releases the hold on an array of dmu_buf_t*'s, and 493 * frees the array. The hold on the array of buffers MUST be released 494 * with dmu_buf_rele_array. You can NOT release the hold on each buffer 495 * individually with dmu_buf_rele. 496 */ 497int dmu_buf_hold_array_by_bonus(dmu_buf_t *db, uint64_t offset, 498 uint64_t length, boolean_t read, void *tag, 499 int *numbufsp, dmu_buf_t ***dbpp); 500void dmu_buf_rele_array(dmu_buf_t **, int numbufs, void *tag); 501 502typedef void dmu_buf_evict_func_t(void *user_ptr); 503 504/* 505 * A DMU buffer user object may be associated with a dbuf for the 506 * duration of its lifetime. This allows the user of a dbuf (client) 507 * to attach private data to a dbuf (e.g. in-core only data such as a 508 * dnode_children_t, zap_t, or zap_leaf_t) and be optionally notified 509 * when that dbuf has been evicted. Clients typically respond to the 510 * eviction notification by freeing their private data, thus ensuring 511 * the same lifetime for both dbuf and private data. 512 * 513 * The mapping from a dmu_buf_user_t to any client private data is the 514 * client's responsibility. All current consumers of the API with private 515 * data embed a dmu_buf_user_t as the first member of the structure for 516 * their private data. This allows conversions between the two types 517 * with a simple cast. Since the DMU buf user API never needs access 518 * to the private data, other strategies can be employed if necessary 519 * or convenient for the client (e.g. using container_of() to do the 520 * conversion for private data that cannot have the dmu_buf_user_t as 521 * its first member). 522 * 523 * Eviction callbacks are executed without the dbuf mutex held or any 524 * other type of mechanism to guarantee that the dbuf is still available. 525 * For this reason, users must assume the dbuf has already been freed 526 * and not reference the dbuf from the callback context. 527 * 528 * Users requesting "immediate eviction" are notified as soon as the dbuf 529 * is only referenced by dirty records (dirties == holds). Otherwise the 530 * notification occurs after eviction processing for the dbuf begins. 531 */ 532typedef struct dmu_buf_user { 533 /* 534 * Asynchronous user eviction callback state. 535 */ 536 taskq_ent_t dbu_tqent; 537 538 /* This instance's eviction function pointer. */ 539 dmu_buf_evict_func_t *dbu_evict_func; 540#ifdef ZFS_DEBUG 541 /* 542 * Pointer to user's dbuf pointer. NULL for clients that do 543 * not associate a dbuf with their user data. 544 * 545 * The dbuf pointer is cleared upon eviction so as to catch 546 * use-after-evict bugs in clients. 547 */ 548 dmu_buf_t **dbu_clear_on_evict_dbufp; 549#endif 550} dmu_buf_user_t; 551 552/* 553 * Initialize the given dmu_buf_user_t instance with the eviction function 554 * evict_func, to be called when the user is evicted. 555 * 556 * NOTE: This function should only be called once on a given dmu_buf_user_t. 557 * To allow enforcement of this, dbu must already be zeroed on entry. 558 */ 559#ifdef __lint 560/* Very ugly, but it beats issuing suppression directives in many Makefiles. */ 561extern void 562dmu_buf_init_user(dmu_buf_user_t *dbu, dmu_buf_evict_func_t *evict_func, 563 dmu_buf_t **clear_on_evict_dbufp); 564#else /* __lint */ 565static inline void 566dmu_buf_init_user(dmu_buf_user_t *dbu, dmu_buf_evict_func_t *evict_func, 567 dmu_buf_t **clear_on_evict_dbufp) 568{ 569 ASSERT(dbu->dbu_evict_func == NULL); 570 ASSERT(evict_func != NULL); 571 dbu->dbu_evict_func = evict_func; 572#ifdef ZFS_DEBUG 573 dbu->dbu_clear_on_evict_dbufp = clear_on_evict_dbufp; 574#endif 575} 576#endif /* __lint */ 577 578/* 579 * Attach user data to a dbuf and mark it for normal (when the dbuf's 580 * data is cleared or its reference count goes to zero) eviction processing. 581 * 582 * Returns NULL on success, or the existing user if another user currently 583 * owns the buffer. 584 */ 585void *dmu_buf_set_user(dmu_buf_t *db, dmu_buf_user_t *user); 586 587/* 588 * Attach user data to a dbuf and mark it for immediate (its dirty and 589 * reference counts are equal) eviction processing. 590 * 591 * Returns NULL on success, or the existing user if another user currently 592 * owns the buffer. 593 */ 594void *dmu_buf_set_user_ie(dmu_buf_t *db, dmu_buf_user_t *user); 595 596/* 597 * Replace the current user of a dbuf. 598 * 599 * If given the current user of a dbuf, replaces the dbuf's user with 600 * "new_user" and returns the user data pointer that was replaced. 601 * Otherwise returns the current, and unmodified, dbuf user pointer. 602 */ 603void *dmu_buf_replace_user(dmu_buf_t *db, 604 dmu_buf_user_t *old_user, dmu_buf_user_t *new_user); 605 606/* 607 * Remove the specified user data for a DMU buffer. 608 * 609 * Returns the user that was removed on success, or the current user if 610 * another user currently owns the buffer. 611 */ 612void *dmu_buf_remove_user(dmu_buf_t *db, dmu_buf_user_t *user); 613 614/* 615 * Returns the user data (dmu_buf_user_t *) associated with this dbuf. 616 */ 617void *dmu_buf_get_user(dmu_buf_t *db); 618 619/* Block until any in-progress dmu buf user evictions complete. */ 620void dmu_buf_user_evict_wait(void); 621 622/* 623 * Returns the blkptr associated with this dbuf, or NULL if not set. 624 */ 625struct blkptr *dmu_buf_get_blkptr(dmu_buf_t *db); 626 627/* 628 * Indicate that you are going to modify the buffer's data (db_data). 629 * 630 * The transaction (tx) must be assigned to a txg (ie. you've called 631 * dmu_tx_assign()). The buffer's object must be held in the tx 632 * (ie. you've called dmu_tx_hold_object(tx, db->db_object)). 633 */ 634void dmu_buf_will_dirty(dmu_buf_t *db, dmu_tx_t *tx); 635 636/* 637 * Tells if the given dbuf is freeable. 638 */ 639boolean_t dmu_buf_freeable(dmu_buf_t *); 640 641/* 642 * You must create a transaction, then hold the objects which you will 643 * (or might) modify as part of this transaction. Then you must assign 644 * the transaction to a transaction group. Once the transaction has 645 * been assigned, you can modify buffers which belong to held objects as 646 * part of this transaction. You can't modify buffers before the 647 * transaction has been assigned; you can't modify buffers which don't 648 * belong to objects which this transaction holds; you can't hold 649 * objects once the transaction has been assigned. You may hold an 650 * object which you are going to free (with dmu_object_free()), but you 651 * don't have to. 652 * 653 * You can abort the transaction before it has been assigned. 654 * 655 * Note that you may hold buffers (with dmu_buf_hold) at any time, 656 * regardless of transaction state. 657 */ 658 659#define DMU_NEW_OBJECT (-1ULL) 660#define DMU_OBJECT_END (-1ULL) 661 662dmu_tx_t *dmu_tx_create(objset_t *os); 663void dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len); 664void dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off, 665 uint64_t len); 666void dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name); 667void dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object); 668void dmu_tx_hold_spill(dmu_tx_t *tx, uint64_t object); 669void dmu_tx_hold_sa(dmu_tx_t *tx, struct sa_handle *hdl, boolean_t may_grow); 670void dmu_tx_hold_sa_create(dmu_tx_t *tx, int total_size); 671void dmu_tx_abort(dmu_tx_t *tx); 672int dmu_tx_assign(dmu_tx_t *tx, enum txg_how txg_how); 673void dmu_tx_wait(dmu_tx_t *tx); 674void dmu_tx_commit(dmu_tx_t *tx); 675void dmu_tx_mark_netfree(dmu_tx_t *tx); 676 677/* 678 * To register a commit callback, dmu_tx_callback_register() must be called. 679 * 680 * dcb_data is a pointer to caller private data that is passed on as a 681 * callback parameter. The caller is responsible for properly allocating and 682 * freeing it. 683 * 684 * When registering a callback, the transaction must be already created, but 685 * it cannot be committed or aborted. It can be assigned to a txg or not. 686 * 687 * The callback will be called after the transaction has been safely written 688 * to stable storage and will also be called if the dmu_tx is aborted. 689 * If there is any error which prevents the transaction from being committed to 690 * disk, the callback will be called with a value of error != 0. 691 */ 692typedef void dmu_tx_callback_func_t(void *dcb_data, int error); 693 694void dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *dcb_func, 695 void *dcb_data); 696 697/* 698 * Free up the data blocks for a defined range of a file. If size is 699 * -1, the range from offset to end-of-file is freed. 700 */ 701int dmu_free_range(objset_t *os, uint64_t object, uint64_t offset, 702 uint64_t size, dmu_tx_t *tx); 703int dmu_free_long_range(objset_t *os, uint64_t object, uint64_t offset, 704 uint64_t size); 705int dmu_free_long_object(objset_t *os, uint64_t object); 706 707/* 708 * Convenience functions. 709 * 710 * Canfail routines will return 0 on success, or an errno if there is a 711 * nonrecoverable I/O error. 712 */ 713#define DMU_READ_PREFETCH 0 /* prefetch */ 714#define DMU_READ_NO_PREFETCH 1 /* don't prefetch */ 715int dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 716 void *buf, uint32_t flags); 717void dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 718 const void *buf, dmu_tx_t *tx); 719void dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 720 dmu_tx_t *tx); 721int dmu_read_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size); 722int dmu_read_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size); 723int dmu_write_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size, 724 dmu_tx_t *tx); 725int dmu_write_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size, 726 dmu_tx_t *tx); 727#ifdef _KERNEL 728#ifdef illumos 729int dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset, 730 uint64_t size, struct page *pp, dmu_tx_t *tx); 731#else 732int dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset, 733 uint64_t size, struct vm_page **ppa, dmu_tx_t *tx); 734#endif 735#endif 736struct arc_buf *dmu_request_arcbuf(dmu_buf_t *handle, int size); 737void dmu_return_arcbuf(struct arc_buf *buf); 738void dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, struct arc_buf *buf, 739 dmu_tx_t *tx); 740int dmu_xuio_init(struct xuio *uio, int niov); 741void dmu_xuio_fini(struct xuio *uio); 742int dmu_xuio_add(struct xuio *uio, struct arc_buf *abuf, offset_t off, 743 size_t n); 744int dmu_xuio_cnt(struct xuio *uio); 745struct arc_buf *dmu_xuio_arcbuf(struct xuio *uio, int i); 746void dmu_xuio_clear(struct xuio *uio, int i); 747void xuio_stat_wbuf_copied(); 748void xuio_stat_wbuf_nocopy(); 749 750extern boolean_t zfs_prefetch_disable; 751extern int zfs_max_recordsize; 752 753/* 754 * Asynchronously try to read in the data. 755 */ 756void dmu_prefetch(objset_t *os, uint64_t object, int64_t level, uint64_t offset, 757 uint64_t len, enum zio_priority pri); 758 759typedef struct dmu_object_info { 760 /* All sizes are in bytes unless otherwise indicated. */ 761 uint32_t doi_data_block_size; 762 uint32_t doi_metadata_block_size; 763 dmu_object_type_t doi_type; 764 dmu_object_type_t doi_bonus_type; 765 uint64_t doi_bonus_size; 766 uint8_t doi_indirection; /* 2 = dnode->indirect->data */ 767 uint8_t doi_checksum; 768 uint8_t doi_compress; 769 uint8_t doi_nblkptr; 770 uint8_t doi_pad[4]; 771 uint64_t doi_physical_blocks_512; /* data + metadata, 512b blks */ 772 uint64_t doi_max_offset; 773 uint64_t doi_fill_count; /* number of non-empty blocks */ 774} dmu_object_info_t; 775 776typedef void arc_byteswap_func_t(void *buf, size_t size); 777 778typedef struct dmu_object_type_info { 779 dmu_object_byteswap_t ot_byteswap; 780 boolean_t ot_metadata; 781 char *ot_name; 782} dmu_object_type_info_t; 783 784typedef struct dmu_object_byteswap_info { 785 arc_byteswap_func_t *ob_func; 786 char *ob_name; 787} dmu_object_byteswap_info_t; 788 789extern const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES]; 790extern const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS]; 791 792/* 793 * Get information on a DMU object. 794 * 795 * Return 0 on success or ENOENT if object is not allocated. 796 * 797 * If doi is NULL, just indicates whether the object exists. 798 */ 799int dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi); 800/* Like dmu_object_info, but faster if you have a held dnode in hand. */ 801void dmu_object_info_from_dnode(struct dnode *dn, dmu_object_info_t *doi); 802/* Like dmu_object_info, but faster if you have a held dbuf in hand. */ 803void dmu_object_info_from_db(dmu_buf_t *db, dmu_object_info_t *doi); 804/* 805 * Like dmu_object_info_from_db, but faster still when you only care about 806 * the size. This is specifically optimized for zfs_getattr(). 807 */ 808void dmu_object_size_from_db(dmu_buf_t *db, uint32_t *blksize, 809 u_longlong_t *nblk512); 810 811typedef struct dmu_objset_stats { 812 uint64_t dds_num_clones; /* number of clones of this */ 813 uint64_t dds_creation_txg; 814 uint64_t dds_guid; 815 dmu_objset_type_t dds_type; 816 uint8_t dds_is_snapshot; 817 uint8_t dds_inconsistent; 818 char dds_origin[MAXNAMELEN]; 819} dmu_objset_stats_t; 820 821/* 822 * Get stats on a dataset. 823 */ 824void dmu_objset_fast_stat(objset_t *os, dmu_objset_stats_t *stat); 825 826/* 827 * Add entries to the nvlist for all the objset's properties. See 828 * zfs_prop_table[] and zfs(1m) for details on the properties. 829 */ 830void dmu_objset_stats(objset_t *os, struct nvlist *nv); 831 832/* 833 * Get the space usage statistics for statvfs(). 834 * 835 * refdbytes is the amount of space "referenced" by this objset. 836 * availbytes is the amount of space available to this objset, taking 837 * into account quotas & reservations, assuming that no other objsets 838 * use the space first. These values correspond to the 'referenced' and 839 * 'available' properties, described in the zfs(1m) manpage. 840 * 841 * usedobjs and availobjs are the number of objects currently allocated, 842 * and available. 843 */ 844void dmu_objset_space(objset_t *os, uint64_t *refdbytesp, uint64_t *availbytesp, 845 uint64_t *usedobjsp, uint64_t *availobjsp); 846 847/* 848 * The fsid_guid is a 56-bit ID that can change to avoid collisions. 849 * (Contrast with the ds_guid which is a 64-bit ID that will never 850 * change, so there is a small probability that it will collide.) 851 */ 852uint64_t dmu_objset_fsid_guid(objset_t *os); 853 854/* 855 * Get the [cm]time for an objset's snapshot dir 856 */ 857timestruc_t dmu_objset_snap_cmtime(objset_t *os); 858 859int dmu_objset_is_snapshot(objset_t *os); 860 861extern struct spa *dmu_objset_spa(objset_t *os); 862extern struct zilog *dmu_objset_zil(objset_t *os); 863extern struct dsl_pool *dmu_objset_pool(objset_t *os); 864extern struct dsl_dataset *dmu_objset_ds(objset_t *os); 865extern void dmu_objset_name(objset_t *os, char *buf); 866extern dmu_objset_type_t dmu_objset_type(objset_t *os); 867extern uint64_t dmu_objset_id(objset_t *os); 868extern zfs_sync_type_t dmu_objset_syncprop(objset_t *os); 869extern zfs_logbias_op_t dmu_objset_logbias(objset_t *os); 870extern int dmu_snapshot_list_next(objset_t *os, int namelen, char *name, 871 uint64_t *id, uint64_t *offp, boolean_t *case_conflict); 872extern int dmu_snapshot_realname(objset_t *os, char *name, char *real, 873 int maxlen, boolean_t *conflict); 874extern int dmu_dir_list_next(objset_t *os, int namelen, char *name, 875 uint64_t *idp, uint64_t *offp); 876 877typedef int objset_used_cb_t(dmu_object_type_t bonustype, 878 void *bonus, uint64_t *userp, uint64_t *groupp); 879extern void dmu_objset_register_type(dmu_objset_type_t ost, 880 objset_used_cb_t *cb); 881extern void dmu_objset_set_user(objset_t *os, void *user_ptr); 882extern void *dmu_objset_get_user(objset_t *os); 883 884/* 885 * Return the txg number for the given assigned transaction. 886 */ 887uint64_t dmu_tx_get_txg(dmu_tx_t *tx); 888 889/* 890 * Synchronous write. 891 * If a parent zio is provided this function initiates a write on the 892 * provided buffer as a child of the parent zio. 893 * In the absence of a parent zio, the write is completed synchronously. 894 * At write completion, blk is filled with the bp of the written block. 895 * Note that while the data covered by this function will be on stable 896 * storage when the write completes this new data does not become a 897 * permanent part of the file until the associated transaction commits. 898 */ 899 900/* 901 * {zfs,zvol,ztest}_get_done() args 902 */ 903typedef struct zgd { 904 struct zilog *zgd_zilog; 905 struct blkptr *zgd_bp; 906 dmu_buf_t *zgd_db; 907 struct rl *zgd_rl; 908 void *zgd_private; 909} zgd_t; 910 911typedef void dmu_sync_cb_t(zgd_t *arg, int error); 912int dmu_sync(struct zio *zio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd); 913 914/* 915 * Find the next hole or data block in file starting at *off 916 * Return found offset in *off. Return ESRCH for end of file. 917 */ 918int dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole, 919 uint64_t *off); 920 921/* 922 * Check if a DMU object has any dirty blocks. If so, sync out 923 * all pending transaction groups. Otherwise, this function 924 * does not alter DMU state. This could be improved to only sync 925 * out the necessary transaction groups for this particular 926 * object. 927 */ 928int dmu_object_wait_synced(objset_t *os, uint64_t object); 929 930/* 931 * Initial setup and final teardown. 932 */ 933extern void dmu_init(void); 934extern void dmu_fini(void); 935 936typedef void (*dmu_traverse_cb_t)(objset_t *os, void *arg, struct blkptr *bp, 937 uint64_t object, uint64_t offset, int len); 938void dmu_traverse_objset(objset_t *os, uint64_t txg_start, 939 dmu_traverse_cb_t cb, void *arg); 940int dmu_diff(const char *tosnap_name, const char *fromsnap_name, 941 struct file *fp, offset_t *offp); 942 943/* CRC64 table */ 944#define ZFS_CRC64_POLY 0xC96C5795D7870F42ULL /* ECMA-182, reflected form */ 945extern uint64_t zfs_crc64_table[256]; 946 947extern int zfs_mdcomp_disable; 948 949#ifdef __cplusplus 950} 951#endif 952 953#endif /* _SYS_DMU_H */ 954