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/inttypes.h> 49 #include <sys/cred.h> 50 #include <sys/fs/zfs.h> 51 #include <sys/zio_priority.h> 52 53 #ifdef __cplusplus 54 extern "C" { 55 #endif 56 57 struct uio; 58 struct xuio; 59 struct page; 60 struct vnode; 61 struct spa; 62 struct zilog; 63 struct zio; 64 struct blkptr; 65 struct zap_cursor; 66 struct dsl_dataset; 67 struct dsl_pool; 68 struct dnode; 69 struct drr_begin; 70 struct drr_end; 71 struct zbookmark_phys; 72 struct spa; 73 struct nvlist; 74 struct arc_buf; 75 struct zio_prop; 76 struct sa_handle; 77 78 typedef struct objset objset_t; 79 typedef struct dmu_tx dmu_tx_t; 80 typedef struct dsl_dir dsl_dir_t; 81 82 typedef 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) 136 137 typedef 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; 231 232 typedef enum txg_how { 233 TXG_WAIT = 1, 234 TXG_NOWAIT, 235 TXG_WAITED, 236 } txg_how_t; 237 238 void byteswap_uint64_array(void *buf, size_t size); 239 void byteswap_uint32_array(void *buf, size_t size); 240 void byteswap_uint16_array(void *buf, size_t size); 241 void byteswap_uint8_array(void *buf, size_t size); 242 void zap_byteswap(void *buf, size_t size); 243 void zfs_oldacl_byteswap(void *buf, size_t size); 244 void zfs_acl_byteswap(void *buf, size_t size); 245 void 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 */ 269 int dmu_objset_hold(const char *name, void *tag, objset_t **osp); 270 int dmu_objset_own(const char *name, dmu_objset_type_t type, 271 boolean_t readonly, void *tag, objset_t **osp); 272 void dmu_objset_rele(objset_t *os, void *tag); 273 void dmu_objset_disown(objset_t *os, void *tag); 274 int dmu_objset_open_ds(struct dsl_dataset *ds, objset_t **osp); 275 276 void dmu_objset_evict_dbufs(objset_t *os); 277 int 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); 279 int dmu_objset_clone(const char *name, const char *origin); 280 int dsl_destroy_snapshots_nvl(struct nvlist *snaps, boolean_t defer, 281 struct nvlist *errlist); 282 int dmu_objset_snapshot_one(const char *fsname, const char *snapname); 283 int dmu_objset_snapshot_tmp(const char *, const char *, int); 284 int dmu_objset_find(char *name, int func(const char *, void *), void *arg, 285 int flags); 286 void dmu_objset_byteswap(void *buf, size_t size); 287 int dsl_dataset_rename_snapshot(const char *fsname, 288 const char *oldsnapname, const char *newsnapname, boolean_t recursive); 289 290 typedef struct dmu_buf { 291 uint64_t db_object; /* object that this buffer is part of */ 292 uint64_t db_offset; /* byte offset in this object */ 293 uint64_t db_size; /* size of buffer in bytes */ 294 void *db_data; /* data in buffer */ 295 } dmu_buf_t; 296 297 /* 298 * The names of zap entries in the DIRECTORY_OBJECT of the MOS. 299 */ 300 #define DMU_POOL_DIRECTORY_OBJECT 1 301 #define DMU_POOL_CONFIG "config" 302 #define DMU_POOL_FEATURES_FOR_WRITE "features_for_write" 303 #define DMU_POOL_FEATURES_FOR_READ "features_for_read" 304 #define DMU_POOL_FEATURE_DESCRIPTIONS "feature_descriptions" 305 #define DMU_POOL_FEATURE_ENABLED_TXG "feature_enabled_txg" 306 #define DMU_POOL_ROOT_DATASET "root_dataset" 307 #define DMU_POOL_SYNC_BPOBJ "sync_bplist" 308 #define DMU_POOL_ERRLOG_SCRUB "errlog_scrub" 309 #define DMU_POOL_ERRLOG_LAST "errlog_last" 310 #define DMU_POOL_SPARES "spares" 311 #define DMU_POOL_DEFLATE "deflate" 312 #define DMU_POOL_HISTORY "history" 313 #define DMU_POOL_PROPS "pool_props" 314 #define DMU_POOL_L2CACHE "l2cache" 315 #define DMU_POOL_TMP_USERREFS "tmp_userrefs" 316 #define DMU_POOL_DDT "DDT-%s-%s-%s" 317 #define DMU_POOL_DDT_STATS "DDT-statistics" 318 #define DMU_POOL_CREATION_VERSION "creation_version" 319 #define DMU_POOL_SCAN "scan" 320 #define DMU_POOL_FREE_BPOBJ "free_bpobj" 321 #define DMU_POOL_BPTREE_OBJ "bptree_obj" 322 #define DMU_POOL_EMPTY_BPOBJ "empty_bpobj" 323 #define DMU_POOL_CHECKSUM_SALT "org.illumos:checksum_salt" 324 325 /* 326 * Allocate an object from this objset. The range of object numbers 327 * available is (0, DN_MAX_OBJECT). Object 0 is the meta-dnode. 328 * 329 * The transaction must be assigned to a txg. The newly allocated 330 * object will be "held" in the transaction (ie. you can modify the 331 * newly allocated object in this transaction). 332 * 333 * dmu_object_alloc() chooses an object and returns it in *objectp. 334 * 335 * dmu_object_claim() allocates a specific object number. If that 336 * number is already allocated, it fails and returns EEXIST. 337 * 338 * Return 0 on success, or ENOSPC or EEXIST as specified above. 339 */ 340 uint64_t dmu_object_alloc(objset_t *os, dmu_object_type_t ot, 341 int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx); 342 int dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot, 343 int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx); 344 int dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot, 345 int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *txp); 346 347 /* 348 * Free an object from this objset. 349 * 350 * The object's data will be freed as well (ie. you don't need to call 351 * dmu_free(object, 0, -1, tx)). 352 * 353 * The object need not be held in the transaction. 354 * 355 * If there are any holds on this object's buffers (via dmu_buf_hold()), 356 * or tx holds on the object (via dmu_tx_hold_object()), you can not 357 * free it; it fails and returns EBUSY. 358 * 359 * If the object is not allocated, it fails and returns ENOENT. 360 * 361 * Return 0 on success, or EBUSY or ENOENT as specified above. 362 */ 363 int dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx); 364 365 /* 366 * Find the next allocated or free object. 367 * 368 * The objectp parameter is in-out. It will be updated to be the next 369 * object which is allocated. Ignore objects which have not been 370 * modified since txg. 371 * 372 * XXX Can only be called on a objset with no dirty data. 373 * 374 * Returns 0 on success, or ENOENT if there are no more objects. 375 */ 376 int dmu_object_next(objset_t *os, uint64_t *objectp, 377 boolean_t hole, uint64_t txg); 378 379 /* 380 * Set the data blocksize for an object. 381 * 382 * The object cannot have any blocks allcated beyond the first. If 383 * the first block is allocated already, the new size must be greater 384 * than the current block size. If these conditions are not met, 385 * ENOTSUP will be returned. 386 * 387 * Returns 0 on success, or EBUSY if there are any holds on the object 388 * contents, or ENOTSUP as described above. 389 */ 390 int dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size, 391 int ibs, dmu_tx_t *tx); 392 393 /* 394 * Set the checksum property on a dnode. The new checksum algorithm will 395 * apply to all newly written blocks; existing blocks will not be affected. 396 */ 397 void dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum, 398 dmu_tx_t *tx); 399 400 /* 401 * Set the compress property on a dnode. The new compression algorithm will 402 * apply to all newly written blocks; existing blocks will not be affected. 403 */ 404 void dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress, 405 dmu_tx_t *tx); 406 407 void 408 dmu_write_embedded(objset_t *os, uint64_t object, uint64_t offset, 409 void *data, uint8_t etype, uint8_t comp, int uncompressed_size, 410 int compressed_size, int byteorder, dmu_tx_t *tx); 411 412 /* 413 * Decide how to write a block: checksum, compression, number of copies, etc. 414 */ 415 #define WP_NOFILL 0x1 416 #define WP_DMU_SYNC 0x2 417 #define WP_SPILL 0x4 418 419 void dmu_write_policy(objset_t *os, struct dnode *dn, int level, int wp, 420 struct zio_prop *zp); 421 /* 422 * The bonus data is accessed more or less like a regular buffer. 423 * You must dmu_bonus_hold() to get the buffer, which will give you a 424 * dmu_buf_t with db_offset==-1ULL, and db_size = the size of the bonus 425 * data. As with any normal buffer, you must call dmu_buf_read() to 426 * read db_data, dmu_buf_will_dirty() before modifying it, and the 427 * object must be held in an assigned transaction before calling 428 * dmu_buf_will_dirty. You may use dmu_buf_set_user() on the bonus 429 * buffer as well. You must release your hold with dmu_buf_rele(). 430 * 431 * Returns ENOENT, EIO, or 0. 432 */ 433 int dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **); 434 int dmu_bonus_max(void); 435 int dmu_set_bonus(dmu_buf_t *, int, dmu_tx_t *); 436 int dmu_set_bonustype(dmu_buf_t *, dmu_object_type_t, dmu_tx_t *); 437 dmu_object_type_t dmu_get_bonustype(dmu_buf_t *); 438 int dmu_rm_spill(objset_t *, uint64_t, dmu_tx_t *); 439 440 /* 441 * Special spill buffer support used by "SA" framework 442 */ 443 444 int dmu_spill_hold_by_bonus(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp); 445 int dmu_spill_hold_by_dnode(struct dnode *dn, uint32_t flags, 446 void *tag, dmu_buf_t **dbp); 447 int dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp); 448 449 /* 450 * Obtain the DMU buffer from the specified object which contains the 451 * specified offset. dmu_buf_hold() puts a "hold" on the buffer, so 452 * that it will remain in memory. You must release the hold with 453 * dmu_buf_rele(). You musn't access the dmu_buf_t after releasing your 454 * hold. You must have a hold on any dmu_buf_t* you pass to the DMU. 455 * 456 * You must call dmu_buf_read, dmu_buf_will_dirty, or dmu_buf_will_fill 457 * on the returned buffer before reading or writing the buffer's 458 * db_data. The comments for those routines describe what particular 459 * operations are valid after calling them. 460 * 461 * The object number must be a valid, allocated object number. 462 */ 463 int dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset, 464 void *tag, dmu_buf_t **, int flags); 465 466 /* 467 * Add a reference to a dmu buffer that has already been held via 468 * dmu_buf_hold() in the current context. 469 */ 470 void dmu_buf_add_ref(dmu_buf_t *db, void* tag); 471 472 /* 473 * Attempt to add a reference to a dmu buffer that is in an unknown state, 474 * using a pointer that may have been invalidated by eviction processing. 475 * The request will succeed if the passed in dbuf still represents the 476 * same os/object/blkid, is ineligible for eviction, and has at least 477 * one hold by a user other than the syncer. 478 */ 479 boolean_t dmu_buf_try_add_ref(dmu_buf_t *, objset_t *os, uint64_t object, 480 uint64_t blkid, void *tag); 481 482 void dmu_buf_rele(dmu_buf_t *db, void *tag); 483 uint64_t dmu_buf_refcount(dmu_buf_t *db); 484 485 /* 486 * dmu_buf_hold_array holds the DMU buffers which contain all bytes in a 487 * range of an object. A pointer to an array of dmu_buf_t*'s is 488 * returned (in *dbpp). 489 * 490 * dmu_buf_rele_array releases the hold on an array of dmu_buf_t*'s, and 491 * frees the array. The hold on the array of buffers MUST be released 492 * with dmu_buf_rele_array. You can NOT release the hold on each buffer 493 * individually with dmu_buf_rele. 494 */ 495 int dmu_buf_hold_array_by_bonus(dmu_buf_t *db, uint64_t offset, 496 uint64_t length, boolean_t read, void *tag, 497 int *numbufsp, dmu_buf_t ***dbpp); 498 void dmu_buf_rele_array(dmu_buf_t **, int numbufs, void *tag); 499 500 typedef void dmu_buf_evict_func_t(void *user_ptr); 501 502 /* 503 * A DMU buffer user object may be associated with a dbuf for the 504 * duration of its lifetime. This allows the user of a dbuf (client) 505 * to attach private data to a dbuf (e.g. in-core only data such as a 506 * dnode_children_t, zap_t, or zap_leaf_t) and be optionally notified 507 * when that dbuf has been evicted. Clients typically respond to the 508 * eviction notification by freeing their private data, thus ensuring 509 * the same lifetime for both dbuf and private data. 510 * 511 * The mapping from a dmu_buf_user_t to any client private data is the 512 * client's responsibility. All current consumers of the API with private 513 * data embed a dmu_buf_user_t as the first member of the structure for 514 * their private data. This allows conversions between the two types 515 * with a simple cast. Since the DMU buf user API never needs access 516 * to the private data, other strategies can be employed if necessary 517 * or convenient for the client (e.g. using container_of() to do the 518 * conversion for private data that cannot have the dmu_buf_user_t as 519 * its first member). 520 * 521 * Eviction callbacks are executed without the dbuf mutex held or any 522 * other type of mechanism to guarantee that the dbuf is still available. 523 * For this reason, users must assume the dbuf has already been freed 524 * and not reference the dbuf from the callback context. 525 * 526 * Users requesting "immediate eviction" are notified as soon as the dbuf 527 * is only referenced by dirty records (dirties == holds). Otherwise the 528 * notification occurs after eviction processing for the dbuf begins. 529 */ 530 typedef struct dmu_buf_user { 531 /* 532 * Asynchronous user eviction callback state. 533 */ 534 taskq_ent_t dbu_tqent; 535 536 /* This instance's eviction function pointer. */ 537 dmu_buf_evict_func_t *dbu_evict_func; 538 #ifdef ZFS_DEBUG 539 /* 540 * Pointer to user's dbuf pointer. NULL for clients that do 541 * not associate a dbuf with their user data. 542 * 543 * The dbuf pointer is cleared upon eviction so as to catch 544 * use-after-evict bugs in clients. 545 */ 546 dmu_buf_t **dbu_clear_on_evict_dbufp; 547 #endif 548 } dmu_buf_user_t; 549 550 /* 551 * Initialize the given dmu_buf_user_t instance with the eviction function 552 * evict_func, to be called when the user is evicted. 553 * 554 * NOTE: This function should only be called once on a given dmu_buf_user_t. 555 * To allow enforcement of this, dbu must already be zeroed on entry. 556 */ 557 #ifdef __lint 558 /* Very ugly, but it beats issuing suppression directives in many Makefiles. */ 559 extern void 560 dmu_buf_init_user(dmu_buf_user_t *dbu, dmu_buf_evict_func_t *evict_func, 561 dmu_buf_t **clear_on_evict_dbufp); 562 #else /* __lint */ 563 inline void 564 dmu_buf_init_user(dmu_buf_user_t *dbu, dmu_buf_evict_func_t *evict_func, 565 dmu_buf_t **clear_on_evict_dbufp) 566 { 567 ASSERT(dbu->dbu_evict_func == NULL); 568 ASSERT(evict_func != NULL); 569 dbu->dbu_evict_func = evict_func; 570 #ifdef ZFS_DEBUG 571 dbu->dbu_clear_on_evict_dbufp = clear_on_evict_dbufp; 572 #endif 573 } 574 #endif /* __lint */ 575 576 /* 577 * Attach user data to a dbuf and mark it for normal (when the dbuf's 578 * data is cleared or its reference count goes to zero) eviction processing. 579 * 580 * Returns NULL on success, or the existing user if another user currently 581 * owns the buffer. 582 */ 583 void *dmu_buf_set_user(dmu_buf_t *db, dmu_buf_user_t *user); 584 585 /* 586 * Attach user data to a dbuf and mark it for immediate (its dirty and 587 * reference counts are equal) eviction processing. 588 * 589 * Returns NULL on success, or the existing user if another user currently 590 * owns the buffer. 591 */ 592 void *dmu_buf_set_user_ie(dmu_buf_t *db, dmu_buf_user_t *user); 593 594 /* 595 * Replace the current user of a dbuf. 596 * 597 * If given the current user of a dbuf, replaces the dbuf's user with 598 * "new_user" and returns the user data pointer that was replaced. 599 * Otherwise returns the current, and unmodified, dbuf user pointer. 600 */ 601 void *dmu_buf_replace_user(dmu_buf_t *db, 602 dmu_buf_user_t *old_user, dmu_buf_user_t *new_user); 603 604 /* 605 * Remove the specified user data for a DMU buffer. 606 * 607 * Returns the user that was removed on success, or the current user if 608 * another user currently owns the buffer. 609 */ 610 void *dmu_buf_remove_user(dmu_buf_t *db, dmu_buf_user_t *user); 611 612 /* 613 * Returns the user data (dmu_buf_user_t *) associated with this dbuf. 614 */ 615 void *dmu_buf_get_user(dmu_buf_t *db); 616 617 /* Block until any in-progress dmu buf user evictions complete. */ 618 void dmu_buf_user_evict_wait(void); 619 620 /* 621 * Returns the blkptr associated with this dbuf, or NULL if not set. 622 */ 623 struct blkptr *dmu_buf_get_blkptr(dmu_buf_t *db); 624 625 /* 626 * Indicate that you are going to modify the buffer's data (db_data). 627 * 628 * The transaction (tx) must be assigned to a txg (ie. you've called 629 * dmu_tx_assign()). The buffer's object must be held in the tx 630 * (ie. you've called dmu_tx_hold_object(tx, db->db_object)). 631 */ 632 void dmu_buf_will_dirty(dmu_buf_t *db, dmu_tx_t *tx); 633 634 /* 635 * Tells if the given dbuf is freeable. 636 */ 637 boolean_t dmu_buf_freeable(dmu_buf_t *); 638 639 /* 640 * You must create a transaction, then hold the objects which you will 641 * (or might) modify as part of this transaction. Then you must assign 642 * the transaction to a transaction group. Once the transaction has 643 * been assigned, you can modify buffers which belong to held objects as 644 * part of this transaction. You can't modify buffers before the 645 * transaction has been assigned; you can't modify buffers which don't 646 * belong to objects which this transaction holds; you can't hold 647 * objects once the transaction has been assigned. You may hold an 648 * object which you are going to free (with dmu_object_free()), but you 649 * don't have to. 650 * 651 * You can abort the transaction before it has been assigned. 652 * 653 * Note that you may hold buffers (with dmu_buf_hold) at any time, 654 * regardless of transaction state. 655 */ 656 657 #define DMU_NEW_OBJECT (-1ULL) 658 #define DMU_OBJECT_END (-1ULL) 659 660 dmu_tx_t *dmu_tx_create(objset_t *os); 661 void dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len); 662 void dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off, 663 uint64_t len); 664 void dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name); 665 void dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object); 666 void dmu_tx_hold_spill(dmu_tx_t *tx, uint64_t object); 667 void dmu_tx_hold_sa(dmu_tx_t *tx, struct sa_handle *hdl, boolean_t may_grow); 668 void dmu_tx_hold_sa_create(dmu_tx_t *tx, int total_size); 669 void dmu_tx_abort(dmu_tx_t *tx); 670 int dmu_tx_assign(dmu_tx_t *tx, enum txg_how txg_how); 671 void dmu_tx_wait(dmu_tx_t *tx); 672 void dmu_tx_commit(dmu_tx_t *tx); 673 void dmu_tx_mark_netfree(dmu_tx_t *tx); 674 675 /* 676 * To register a commit callback, dmu_tx_callback_register() must be called. 677 * 678 * dcb_data is a pointer to caller private data that is passed on as a 679 * callback parameter. The caller is responsible for properly allocating and 680 * freeing it. 681 * 682 * When registering a callback, the transaction must be already created, but 683 * it cannot be committed or aborted. It can be assigned to a txg or not. 684 * 685 * The callback will be called after the transaction has been safely written 686 * to stable storage and will also be called if the dmu_tx is aborted. 687 * If there is any error which prevents the transaction from being committed to 688 * disk, the callback will be called with a value of error != 0. 689 */ 690 typedef void dmu_tx_callback_func_t(void *dcb_data, int error); 691 692 void dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *dcb_func, 693 void *dcb_data); 694 695 /* 696 * Free up the data blocks for a defined range of a file. If size is 697 * -1, the range from offset to end-of-file is freed. 698 */ 699 int dmu_free_range(objset_t *os, uint64_t object, uint64_t offset, 700 uint64_t size, dmu_tx_t *tx); 701 int dmu_free_long_range(objset_t *os, uint64_t object, uint64_t offset, 702 uint64_t size); 703 int dmu_free_long_object(objset_t *os, uint64_t object); 704 705 /* 706 * Convenience functions. 707 * 708 * Canfail routines will return 0 on success, or an errno if there is a 709 * nonrecoverable I/O error. 710 */ 711 #define DMU_READ_PREFETCH 0 /* prefetch */ 712 #define DMU_READ_NO_PREFETCH 1 /* don't prefetch */ 713 int dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 714 void *buf, uint32_t flags); 715 void dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 716 const void *buf, dmu_tx_t *tx); 717 void dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 718 dmu_tx_t *tx); 719 int dmu_read_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size); 720 int dmu_read_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size); 721 int dmu_write_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size, 722 dmu_tx_t *tx); 723 int dmu_write_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size, 724 dmu_tx_t *tx); 725 int dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset, 726 uint64_t size, struct page *pp, dmu_tx_t *tx); 727 struct arc_buf *dmu_request_arcbuf(dmu_buf_t *handle, int size); 728 void dmu_return_arcbuf(struct arc_buf *buf); 729 void dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, struct arc_buf *buf, 730 dmu_tx_t *tx); 731 int dmu_xuio_init(struct xuio *uio, int niov); 732 void dmu_xuio_fini(struct xuio *uio); 733 int dmu_xuio_add(struct xuio *uio, struct arc_buf *abuf, offset_t off, 734 size_t n); 735 int dmu_xuio_cnt(struct xuio *uio); 736 struct arc_buf *dmu_xuio_arcbuf(struct xuio *uio, int i); 737 void dmu_xuio_clear(struct xuio *uio, int i); 738 void xuio_stat_wbuf_copied(); 739 void xuio_stat_wbuf_nocopy(); 740 741 extern boolean_t zfs_prefetch_disable; 742 extern int zfs_max_recordsize; 743 744 /* 745 * Asynchronously try to read in the data. 746 */ 747 void dmu_prefetch(objset_t *os, uint64_t object, int64_t level, uint64_t offset, 748 uint64_t len, enum zio_priority pri); 749 750 typedef struct dmu_object_info { 751 /* All sizes are in bytes unless otherwise indicated. */ 752 uint32_t doi_data_block_size; 753 uint32_t doi_metadata_block_size; 754 dmu_object_type_t doi_type; 755 dmu_object_type_t doi_bonus_type; 756 uint64_t doi_bonus_size; 757 uint8_t doi_indirection; /* 2 = dnode->indirect->data */ 758 uint8_t doi_checksum; 759 uint8_t doi_compress; 760 uint8_t doi_nblkptr; 761 uint8_t doi_pad[4]; 762 uint64_t doi_physical_blocks_512; /* data + metadata, 512b blks */ 763 uint64_t doi_max_offset; 764 uint64_t doi_fill_count; /* number of non-empty blocks */ 765 } dmu_object_info_t; 766 767 typedef void arc_byteswap_func_t(void *buf, size_t size); 768 769 typedef struct dmu_object_type_info { 770 dmu_object_byteswap_t ot_byteswap; 771 boolean_t ot_metadata; 772 char *ot_name; 773 } dmu_object_type_info_t; 774 775 typedef struct dmu_object_byteswap_info { 776 arc_byteswap_func_t *ob_func; 777 char *ob_name; 778 } dmu_object_byteswap_info_t; 779 780 extern const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES]; 781 extern const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS]; 782 783 /* 784 * Get information on a DMU object. 785 * 786 * Return 0 on success or ENOENT if object is not allocated. 787 * 788 * If doi is NULL, just indicates whether the object exists. 789 */ 790 int dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi); 791 /* Like dmu_object_info, but faster if you have a held dnode in hand. */ 792 void dmu_object_info_from_dnode(struct dnode *dn, dmu_object_info_t *doi); 793 /* Like dmu_object_info, but faster if you have a held dbuf in hand. */ 794 void dmu_object_info_from_db(dmu_buf_t *db, dmu_object_info_t *doi); 795 /* 796 * Like dmu_object_info_from_db, but faster still when you only care about 797 * the size. This is specifically optimized for zfs_getattr(). 798 */ 799 void dmu_object_size_from_db(dmu_buf_t *db, uint32_t *blksize, 800 u_longlong_t *nblk512); 801 802 typedef struct dmu_objset_stats { 803 uint64_t dds_num_clones; /* number of clones of this */ 804 uint64_t dds_creation_txg; 805 uint64_t dds_guid; 806 dmu_objset_type_t dds_type; 807 uint8_t dds_is_snapshot; 808 uint8_t dds_inconsistent; 809 char dds_origin[MAXNAMELEN]; 810 } dmu_objset_stats_t; 811 812 /* 813 * Get stats on a dataset. 814 */ 815 void dmu_objset_fast_stat(objset_t *os, dmu_objset_stats_t *stat); 816 817 /* 818 * Add entries to the nvlist for all the objset's properties. See 819 * zfs_prop_table[] and zfs(1m) for details on the properties. 820 */ 821 void dmu_objset_stats(objset_t *os, struct nvlist *nv); 822 823 /* 824 * Get the space usage statistics for statvfs(). 825 * 826 * refdbytes is the amount of space "referenced" by this objset. 827 * availbytes is the amount of space available to this objset, taking 828 * into account quotas & reservations, assuming that no other objsets 829 * use the space first. These values correspond to the 'referenced' and 830 * 'available' properties, described in the zfs(1m) manpage. 831 * 832 * usedobjs and availobjs are the number of objects currently allocated, 833 * and available. 834 */ 835 void dmu_objset_space(objset_t *os, uint64_t *refdbytesp, uint64_t *availbytesp, 836 uint64_t *usedobjsp, uint64_t *availobjsp); 837 838 /* 839 * The fsid_guid is a 56-bit ID that can change to avoid collisions. 840 * (Contrast with the ds_guid which is a 64-bit ID that will never 841 * change, so there is a small probability that it will collide.) 842 */ 843 uint64_t dmu_objset_fsid_guid(objset_t *os); 844 845 /* 846 * Get the [cm]time for an objset's snapshot dir 847 */ 848 timestruc_t dmu_objset_snap_cmtime(objset_t *os); 849 850 int dmu_objset_is_snapshot(objset_t *os); 851 852 extern struct spa *dmu_objset_spa(objset_t *os); 853 extern struct zilog *dmu_objset_zil(objset_t *os); 854 extern struct dsl_pool *dmu_objset_pool(objset_t *os); 855 extern struct dsl_dataset *dmu_objset_ds(objset_t *os); 856 extern void dmu_objset_name(objset_t *os, char *buf); 857 extern dmu_objset_type_t dmu_objset_type(objset_t *os); 858 extern uint64_t dmu_objset_id(objset_t *os); 859 extern zfs_sync_type_t dmu_objset_syncprop(objset_t *os); 860 extern zfs_logbias_op_t dmu_objset_logbias(objset_t *os); 861 extern int dmu_snapshot_list_next(objset_t *os, int namelen, char *name, 862 uint64_t *id, uint64_t *offp, boolean_t *case_conflict); 863 extern int dmu_snapshot_realname(objset_t *os, char *name, char *real, 864 int maxlen, boolean_t *conflict); 865 extern int dmu_dir_list_next(objset_t *os, int namelen, char *name, 866 uint64_t *idp, uint64_t *offp); 867 868 typedef int objset_used_cb_t(dmu_object_type_t bonustype, 869 void *bonus, uint64_t *userp, uint64_t *groupp); 870 extern void dmu_objset_register_type(dmu_objset_type_t ost, 871 objset_used_cb_t *cb); 872 extern void dmu_objset_set_user(objset_t *os, void *user_ptr); 873 extern void *dmu_objset_get_user(objset_t *os); 874 875 /* 876 * Return the txg number for the given assigned transaction. 877 */ 878 uint64_t dmu_tx_get_txg(dmu_tx_t *tx); 879 880 /* 881 * Synchronous write. 882 * If a parent zio is provided this function initiates a write on the 883 * provided buffer as a child of the parent zio. 884 * In the absence of a parent zio, the write is completed synchronously. 885 * At write completion, blk is filled with the bp of the written block. 886 * Note that while the data covered by this function will be on stable 887 * storage when the write completes this new data does not become a 888 * permanent part of the file until the associated transaction commits. 889 */ 890 891 /* 892 * {zfs,zvol,ztest}_get_done() args 893 */ 894 typedef struct zgd { 895 struct zilog *zgd_zilog; 896 struct blkptr *zgd_bp; 897 dmu_buf_t *zgd_db; 898 struct rl *zgd_rl; 899 void *zgd_private; 900 } zgd_t; 901 902 typedef void dmu_sync_cb_t(zgd_t *arg, int error); 903 int dmu_sync(struct zio *zio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd); 904 905 /* 906 * Find the next hole or data block in file starting at *off 907 * Return found offset in *off. Return ESRCH for end of file. 908 */ 909 int dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole, 910 uint64_t *off); 911 912 /* 913 * Check if a DMU object has any dirty blocks. If so, sync out 914 * all pending transaction groups. Otherwise, this function 915 * does not alter DMU state. This could be improved to only sync 916 * out the necessary transaction groups for this particular 917 * object. 918 */ 919 int dmu_object_wait_synced(objset_t *os, uint64_t object); 920 921 /* 922 * Initial setup and final teardown. 923 */ 924 extern void dmu_init(void); 925 extern void dmu_fini(void); 926 927 typedef void (*dmu_traverse_cb_t)(objset_t *os, void *arg, struct blkptr *bp, 928 uint64_t object, uint64_t offset, int len); 929 void dmu_traverse_objset(objset_t *os, uint64_t txg_start, 930 dmu_traverse_cb_t cb, void *arg); 931 932 int dmu_diff(const char *tosnap_name, const char *fromsnap_name, 933 struct vnode *vp, offset_t *offp); 934 935 /* CRC64 table */ 936 #define ZFS_CRC64_POLY 0xC96C5795D7870F42ULL /* ECMA-182, reflected form */ 937 extern uint64_t zfs_crc64_table[256]; 938 939 extern int zfs_mdcomp_disable; 940 941 #ifdef __cplusplus 942 } 943 #endif 944 945 #endif /* _SYS_DMU_H */ 946