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, 2016 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 typedef struct dnode dnode_t; 82 83 typedef enum dmu_object_byteswap { 84 DMU_BSWAP_UINT8, 85 DMU_BSWAP_UINT16, 86 DMU_BSWAP_UINT32, 87 DMU_BSWAP_UINT64, 88 DMU_BSWAP_ZAP, 89 DMU_BSWAP_DNODE, 90 DMU_BSWAP_OBJSET, 91 DMU_BSWAP_ZNODE, 92 DMU_BSWAP_OLDACL, 93 DMU_BSWAP_ACL, 94 /* 95 * Allocating a new byteswap type number makes the on-disk format 96 * incompatible with any other format that uses the same number. 97 * 98 * Data can usually be structured to work with one of the 99 * DMU_BSWAP_UINT* or DMU_BSWAP_ZAP types. 100 */ 101 DMU_BSWAP_NUMFUNCS 102 } dmu_object_byteswap_t; 103 104 #define DMU_OT_NEWTYPE 0x80 105 #define DMU_OT_METADATA 0x40 106 #define DMU_OT_BYTESWAP_MASK 0x3f 107 108 /* 109 * Defines a uint8_t object type. Object types specify if the data 110 * in the object is metadata (boolean) and how to byteswap the data 111 * (dmu_object_byteswap_t). 112 */ 113 #define DMU_OT(byteswap, metadata) \ 114 (DMU_OT_NEWTYPE | \ 115 ((metadata) ? DMU_OT_METADATA : 0) | \ 116 ((byteswap) & DMU_OT_BYTESWAP_MASK)) 117 118 #define DMU_OT_IS_VALID(ot) (((ot) & DMU_OT_NEWTYPE) ? \ 119 ((ot) & DMU_OT_BYTESWAP_MASK) < DMU_BSWAP_NUMFUNCS : \ 120 (ot) < DMU_OT_NUMTYPES) 121 122 #define DMU_OT_IS_METADATA(ot) (((ot) & DMU_OT_NEWTYPE) ? \ 123 ((ot) & DMU_OT_METADATA) : \ 124 dmu_ot[(ot)].ot_metadata) 125 126 /* 127 * These object types use bp_fill != 1 for their L0 bp's. Therefore they can't 128 * have their data embedded (i.e. use a BP_IS_EMBEDDED() bp), because bp_fill 129 * is repurposed for embedded BPs. 130 */ 131 #define DMU_OT_HAS_FILL(ot) \ 132 ((ot) == DMU_OT_DNODE || (ot) == DMU_OT_OBJSET) 133 134 #define DMU_OT_BYTESWAP(ot) (((ot) & DMU_OT_NEWTYPE) ? \ 135 ((ot) & DMU_OT_BYTESWAP_MASK) : \ 136 dmu_ot[(ot)].ot_byteswap) 137 138 typedef enum dmu_object_type { 139 DMU_OT_NONE, 140 /* general: */ 141 DMU_OT_OBJECT_DIRECTORY, /* ZAP */ 142 DMU_OT_OBJECT_ARRAY, /* UINT64 */ 143 DMU_OT_PACKED_NVLIST, /* UINT8 (XDR by nvlist_pack/unpack) */ 144 DMU_OT_PACKED_NVLIST_SIZE, /* UINT64 */ 145 DMU_OT_BPOBJ, /* UINT64 */ 146 DMU_OT_BPOBJ_HDR, /* UINT64 */ 147 /* spa: */ 148 DMU_OT_SPACE_MAP_HEADER, /* UINT64 */ 149 DMU_OT_SPACE_MAP, /* UINT64 */ 150 /* zil: */ 151 DMU_OT_INTENT_LOG, /* UINT64 */ 152 /* dmu: */ 153 DMU_OT_DNODE, /* DNODE */ 154 DMU_OT_OBJSET, /* OBJSET */ 155 /* dsl: */ 156 DMU_OT_DSL_DIR, /* UINT64 */ 157 DMU_OT_DSL_DIR_CHILD_MAP, /* ZAP */ 158 DMU_OT_DSL_DS_SNAP_MAP, /* ZAP */ 159 DMU_OT_DSL_PROPS, /* ZAP */ 160 DMU_OT_DSL_DATASET, /* UINT64 */ 161 /* zpl: */ 162 DMU_OT_ZNODE, /* ZNODE */ 163 DMU_OT_OLDACL, /* Old ACL */ 164 DMU_OT_PLAIN_FILE_CONTENTS, /* UINT8 */ 165 DMU_OT_DIRECTORY_CONTENTS, /* ZAP */ 166 DMU_OT_MASTER_NODE, /* ZAP */ 167 DMU_OT_UNLINKED_SET, /* ZAP */ 168 /* zvol: */ 169 DMU_OT_ZVOL, /* UINT8 */ 170 DMU_OT_ZVOL_PROP, /* ZAP */ 171 /* other; for testing only! */ 172 DMU_OT_PLAIN_OTHER, /* UINT8 */ 173 DMU_OT_UINT64_OTHER, /* UINT64 */ 174 DMU_OT_ZAP_OTHER, /* ZAP */ 175 /* new object types: */ 176 DMU_OT_ERROR_LOG, /* ZAP */ 177 DMU_OT_SPA_HISTORY, /* UINT8 */ 178 DMU_OT_SPA_HISTORY_OFFSETS, /* spa_his_phys_t */ 179 DMU_OT_POOL_PROPS, /* ZAP */ 180 DMU_OT_DSL_PERMS, /* ZAP */ 181 DMU_OT_ACL, /* ACL */ 182 DMU_OT_SYSACL, /* SYSACL */ 183 DMU_OT_FUID, /* FUID table (Packed NVLIST UINT8) */ 184 DMU_OT_FUID_SIZE, /* FUID table size UINT64 */ 185 DMU_OT_NEXT_CLONES, /* ZAP */ 186 DMU_OT_SCAN_QUEUE, /* ZAP */ 187 DMU_OT_USERGROUP_USED, /* ZAP */ 188 DMU_OT_USERGROUP_QUOTA, /* ZAP */ 189 DMU_OT_USERREFS, /* ZAP */ 190 DMU_OT_DDT_ZAP, /* ZAP */ 191 DMU_OT_DDT_STATS, /* ZAP */ 192 DMU_OT_SA, /* System attr */ 193 DMU_OT_SA_MASTER_NODE, /* ZAP */ 194 DMU_OT_SA_ATTR_REGISTRATION, /* ZAP */ 195 DMU_OT_SA_ATTR_LAYOUTS, /* ZAP */ 196 DMU_OT_SCAN_XLATE, /* ZAP */ 197 DMU_OT_DEDUP, /* fake dedup BP from ddt_bp_create() */ 198 DMU_OT_DEADLIST, /* ZAP */ 199 DMU_OT_DEADLIST_HDR, /* UINT64 */ 200 DMU_OT_DSL_CLONES, /* ZAP */ 201 DMU_OT_BPOBJ_SUBOBJ, /* UINT64 */ 202 /* 203 * Do not allocate new object types here. Doing so makes the on-disk 204 * format incompatible with any other format that uses the same object 205 * type number. 206 * 207 * When creating an object which does not have one of the above types 208 * use the DMU_OTN_* type with the correct byteswap and metadata 209 * values. 210 * 211 * The DMU_OTN_* types do not have entries in the dmu_ot table, 212 * use the DMU_OT_IS_METDATA() and DMU_OT_BYTESWAP() macros instead 213 * of indexing into dmu_ot directly (this works for both DMU_OT_* types 214 * and DMU_OTN_* types). 215 */ 216 DMU_OT_NUMTYPES, 217 218 /* 219 * Names for valid types declared with DMU_OT(). 220 */ 221 DMU_OTN_UINT8_DATA = DMU_OT(DMU_BSWAP_UINT8, B_FALSE), 222 DMU_OTN_UINT8_METADATA = DMU_OT(DMU_BSWAP_UINT8, B_TRUE), 223 DMU_OTN_UINT16_DATA = DMU_OT(DMU_BSWAP_UINT16, B_FALSE), 224 DMU_OTN_UINT16_METADATA = DMU_OT(DMU_BSWAP_UINT16, B_TRUE), 225 DMU_OTN_UINT32_DATA = DMU_OT(DMU_BSWAP_UINT32, B_FALSE), 226 DMU_OTN_UINT32_METADATA = DMU_OT(DMU_BSWAP_UINT32, B_TRUE), 227 DMU_OTN_UINT64_DATA = DMU_OT(DMU_BSWAP_UINT64, B_FALSE), 228 DMU_OTN_UINT64_METADATA = DMU_OT(DMU_BSWAP_UINT64, B_TRUE), 229 DMU_OTN_ZAP_DATA = DMU_OT(DMU_BSWAP_ZAP, B_FALSE), 230 DMU_OTN_ZAP_METADATA = DMU_OT(DMU_BSWAP_ZAP, B_TRUE), 231 } dmu_object_type_t; 232 233 typedef enum txg_how { 234 TXG_WAIT = 1, 235 TXG_NOWAIT, 236 TXG_WAITED, 237 } txg_how_t; 238 239 void byteswap_uint64_array(void *buf, size_t size); 240 void byteswap_uint32_array(void *buf, size_t size); 241 void byteswap_uint16_array(void *buf, size_t size); 242 void byteswap_uint8_array(void *buf, size_t size); 243 void zap_byteswap(void *buf, size_t size); 244 void zfs_oldacl_byteswap(void *buf, size_t size); 245 void zfs_acl_byteswap(void *buf, size_t size); 246 void zfs_znode_byteswap(void *buf, size_t size); 247 248 #define DS_FIND_SNAPSHOTS (1<<0) 249 #define DS_FIND_CHILDREN (1<<1) 250 #define DS_FIND_SERIALIZE (1<<2) 251 252 /* 253 * The maximum number of bytes that can be accessed as part of one 254 * operation, including metadata. 255 */ 256 #define DMU_MAX_ACCESS (32 * 1024 * 1024) /* 32MB */ 257 #define DMU_MAX_DELETEBLKCNT (20480) /* ~5MB of indirect blocks */ 258 259 #define DMU_USERUSED_OBJECT (-1ULL) 260 #define DMU_GROUPUSED_OBJECT (-2ULL) 261 262 /* 263 * artificial blkids for bonus buffer and spill blocks 264 */ 265 #define DMU_BONUS_BLKID (-1ULL) 266 #define DMU_SPILL_BLKID (-2ULL) 267 /* 268 * Public routines to create, destroy, open, and close objsets. 269 */ 270 int dmu_objset_hold(const char *name, void *tag, objset_t **osp); 271 int dmu_objset_own(const char *name, dmu_objset_type_t type, 272 boolean_t readonly, void *tag, objset_t **osp); 273 void dmu_objset_rele(objset_t *os, void *tag); 274 void dmu_objset_disown(objset_t *os, void *tag); 275 int dmu_objset_open_ds(struct dsl_dataset *ds, objset_t **osp); 276 277 void dmu_objset_evict_dbufs(objset_t *os); 278 int dmu_objset_create(const char *name, dmu_objset_type_t type, uint64_t flags, 279 void (*func)(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx), void *arg); 280 int dmu_objset_clone(const char *name, const char *origin); 281 int dsl_destroy_snapshots_nvl(struct nvlist *snaps, boolean_t defer, 282 struct nvlist *errlist); 283 int dmu_objset_snapshot_one(const char *fsname, const char *snapname); 284 int dmu_objset_snapshot_tmp(const char *, const char *, int); 285 int dmu_objset_find(char *name, int func(const char *, void *), void *arg, 286 int flags); 287 void dmu_objset_byteswap(void *buf, size_t size); 288 int dsl_dataset_rename_snapshot(const char *fsname, 289 const char *oldsnapname, const char *newsnapname, boolean_t recursive); 290 291 typedef struct dmu_buf { 292 uint64_t db_object; /* object that this buffer is part of */ 293 uint64_t db_offset; /* byte offset in this object */ 294 uint64_t db_size; /* size of buffer in bytes */ 295 void *db_data; /* data in buffer */ 296 } dmu_buf_t; 297 298 /* 299 * The names of zap entries in the DIRECTORY_OBJECT of the MOS. 300 */ 301 #define DMU_POOL_DIRECTORY_OBJECT 1 302 #define DMU_POOL_CONFIG "config" 303 #define DMU_POOL_FEATURES_FOR_WRITE "features_for_write" 304 #define DMU_POOL_FEATURES_FOR_READ "features_for_read" 305 #define DMU_POOL_FEATURE_DESCRIPTIONS "feature_descriptions" 306 #define DMU_POOL_FEATURE_ENABLED_TXG "feature_enabled_txg" 307 #define DMU_POOL_ROOT_DATASET "root_dataset" 308 #define DMU_POOL_SYNC_BPOBJ "sync_bplist" 309 #define DMU_POOL_ERRLOG_SCRUB "errlog_scrub" 310 #define DMU_POOL_ERRLOG_LAST "errlog_last" 311 #define DMU_POOL_SPARES "spares" 312 #define DMU_POOL_DEFLATE "deflate" 313 #define DMU_POOL_HISTORY "history" 314 #define DMU_POOL_PROPS "pool_props" 315 #define DMU_POOL_L2CACHE "l2cache" 316 #define DMU_POOL_TMP_USERREFS "tmp_userrefs" 317 #define DMU_POOL_DDT "DDT-%s-%s-%s" 318 #define DMU_POOL_DDT_STATS "DDT-statistics" 319 #define DMU_POOL_CREATION_VERSION "creation_version" 320 #define DMU_POOL_SCAN "scan" 321 #define DMU_POOL_FREE_BPOBJ "free_bpobj" 322 #define DMU_POOL_BPTREE_OBJ "bptree_obj" 323 #define DMU_POOL_EMPTY_BPOBJ "empty_bpobj" 324 #define DMU_POOL_CHECKSUM_SALT "org.illumos:checksum_salt" 325 #define DMU_POOL_VDEV_ZAP_MAP "com.delphix:vdev_zap_map" 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 */ 342 uint64_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); 344 int 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); 346 int 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 */ 365 int 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 */ 378 int 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 */ 392 int 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 */ 399 void 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 */ 406 void dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress, 407 dmu_tx_t *tx); 408 409 void 410 dmu_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 420 421 void dmu_write_policy(objset_t *os, dnode_t *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 */ 435 int dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **); 436 int dmu_bonus_max(void); 437 int dmu_set_bonus(dmu_buf_t *, int, dmu_tx_t *); 438 int dmu_set_bonustype(dmu_buf_t *, dmu_object_type_t, dmu_tx_t *); 439 dmu_object_type_t dmu_get_bonustype(dmu_buf_t *); 440 int dmu_rm_spill(objset_t *, uint64_t, dmu_tx_t *); 441 442 /* 443 * Special spill buffer support used by "SA" framework 444 */ 445 446 int dmu_spill_hold_by_bonus(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp); 447 int dmu_spill_hold_by_dnode(dnode_t *dn, uint32_t flags, 448 void *tag, dmu_buf_t **dbp); 449 int 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 */ 465 int dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset, 466 void *tag, dmu_buf_t **, int flags); 467 int dmu_buf_hold_by_dnode(dnode_t *dn, uint64_t offset, 468 void *tag, dmu_buf_t **dbp, int flags); 469 470 /* 471 * Add a reference to a dmu buffer that has already been held via 472 * dmu_buf_hold() in the current context. 473 */ 474 void dmu_buf_add_ref(dmu_buf_t *db, void* tag); 475 476 /* 477 * Attempt to add a reference to a dmu buffer that is in an unknown state, 478 * using a pointer that may have been invalidated by eviction processing. 479 * The request will succeed if the passed in dbuf still represents the 480 * same os/object/blkid, is ineligible for eviction, and has at least 481 * one hold by a user other than the syncer. 482 */ 483 boolean_t dmu_buf_try_add_ref(dmu_buf_t *, objset_t *os, uint64_t object, 484 uint64_t blkid, void *tag); 485 486 void dmu_buf_rele(dmu_buf_t *db, void *tag); 487 uint64_t dmu_buf_refcount(dmu_buf_t *db); 488 489 /* 490 * dmu_buf_hold_array holds the DMU buffers which contain all bytes in a 491 * range of an object. A pointer to an array of dmu_buf_t*'s is 492 * returned (in *dbpp). 493 * 494 * dmu_buf_rele_array releases the hold on an array of dmu_buf_t*'s, and 495 * frees the array. The hold on the array of buffers MUST be released 496 * with dmu_buf_rele_array. You can NOT release the hold on each buffer 497 * individually with dmu_buf_rele. 498 */ 499 int dmu_buf_hold_array_by_bonus(dmu_buf_t *db, uint64_t offset, 500 uint64_t length, boolean_t read, void *tag, 501 int *numbufsp, dmu_buf_t ***dbpp); 502 void dmu_buf_rele_array(dmu_buf_t **, int numbufs, void *tag); 503 504 typedef void dmu_buf_evict_func_t(void *user_ptr); 505 506 /* 507 * A DMU buffer user object may be associated with a dbuf for the 508 * duration of its lifetime. This allows the user of a dbuf (client) 509 * to attach private data to a dbuf (e.g. in-core only data such as a 510 * dnode_children_t, zap_t, or zap_leaf_t) and be optionally notified 511 * when that dbuf has been evicted. Clients typically respond to the 512 * eviction notification by freeing their private data, thus ensuring 513 * the same lifetime for both dbuf and private data. 514 * 515 * The mapping from a dmu_buf_user_t to any client private data is the 516 * client's responsibility. All current consumers of the API with private 517 * data embed a dmu_buf_user_t as the first member of the structure for 518 * their private data. This allows conversions between the two types 519 * with a simple cast. Since the DMU buf user API never needs access 520 * to the private data, other strategies can be employed if necessary 521 * or convenient for the client (e.g. using container_of() to do the 522 * conversion for private data that cannot have the dmu_buf_user_t as 523 * its first member). 524 * 525 * Eviction callbacks are executed without the dbuf mutex held or any 526 * other type of mechanism to guarantee that the dbuf is still available. 527 * For this reason, users must assume the dbuf has already been freed 528 * and not reference the dbuf from the callback context. 529 * 530 * Users requesting "immediate eviction" are notified as soon as the dbuf 531 * is only referenced by dirty records (dirties == holds). Otherwise the 532 * notification occurs after eviction processing for the dbuf begins. 533 */ 534 typedef struct dmu_buf_user { 535 /* 536 * Asynchronous user eviction callback state. 537 */ 538 taskq_ent_t dbu_tqent; 539 540 /* This instance's eviction function pointer. */ 541 dmu_buf_evict_func_t *dbu_evict_func; 542 #ifdef ZFS_DEBUG 543 /* 544 * Pointer to user's dbuf pointer. NULL for clients that do 545 * not associate a dbuf with their user data. 546 * 547 * The dbuf pointer is cleared upon eviction so as to catch 548 * use-after-evict bugs in clients. 549 */ 550 dmu_buf_t **dbu_clear_on_evict_dbufp; 551 #endif 552 } dmu_buf_user_t; 553 554 /* 555 * Initialize the given dmu_buf_user_t instance with the eviction function 556 * evict_func, to be called when the user is evicted. 557 * 558 * NOTE: This function should only be called once on a given dmu_buf_user_t. 559 * To allow enforcement of this, dbu must already be zeroed on entry. 560 */ 561 #ifdef __lint 562 /* Very ugly, but it beats issuing suppression directives in many Makefiles. */ 563 extern 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 #else /* __lint */ 567 inline void 568 dmu_buf_init_user(dmu_buf_user_t *dbu, dmu_buf_evict_func_t *evict_func, 569 dmu_buf_t **clear_on_evict_dbufp) 570 { 571 ASSERT(dbu->dbu_evict_func == NULL); 572 ASSERT(evict_func != NULL); 573 dbu->dbu_evict_func = evict_func; 574 #ifdef ZFS_DEBUG 575 dbu->dbu_clear_on_evict_dbufp = clear_on_evict_dbufp; 576 #endif 577 } 578 #endif /* __lint */ 579 580 /* 581 * Attach user data to a dbuf and mark it for normal (when the dbuf's 582 * data is cleared or its reference count goes to zero) eviction processing. 583 * 584 * Returns NULL on success, or the existing user if another user currently 585 * owns the buffer. 586 */ 587 void *dmu_buf_set_user(dmu_buf_t *db, dmu_buf_user_t *user); 588 589 /* 590 * Attach user data to a dbuf and mark it for immediate (its dirty and 591 * reference counts are equal) eviction processing. 592 * 593 * Returns NULL on success, or the existing user if another user currently 594 * owns the buffer. 595 */ 596 void *dmu_buf_set_user_ie(dmu_buf_t *db, dmu_buf_user_t *user); 597 598 /* 599 * Replace the current user of a dbuf. 600 * 601 * If given the current user of a dbuf, replaces the dbuf's user with 602 * "new_user" and returns the user data pointer that was replaced. 603 * Otherwise returns the current, and unmodified, dbuf user pointer. 604 */ 605 void *dmu_buf_replace_user(dmu_buf_t *db, 606 dmu_buf_user_t *old_user, dmu_buf_user_t *new_user); 607 608 /* 609 * Remove the specified user data for a DMU buffer. 610 * 611 * Returns the user that was removed on success, or the current user if 612 * another user currently owns the buffer. 613 */ 614 void *dmu_buf_remove_user(dmu_buf_t *db, dmu_buf_user_t *user); 615 616 /* 617 * Returns the user data (dmu_buf_user_t *) associated with this dbuf. 618 */ 619 void *dmu_buf_get_user(dmu_buf_t *db); 620 621 objset_t *dmu_buf_get_objset(dmu_buf_t *db); 622 dnode_t *dmu_buf_dnode_enter(dmu_buf_t *db); 623 void dmu_buf_dnode_exit(dmu_buf_t *db); 624 625 /* Block until any in-progress dmu buf user evictions complete. */ 626 void dmu_buf_user_evict_wait(void); 627 628 /* 629 * Returns the blkptr associated with this dbuf, or NULL if not set. 630 */ 631 struct blkptr *dmu_buf_get_blkptr(dmu_buf_t *db); 632 633 /* 634 * Indicate that you are going to modify the buffer's data (db_data). 635 * 636 * The transaction (tx) must be assigned to a txg (ie. you've called 637 * dmu_tx_assign()). The buffer's object must be held in the tx 638 * (ie. you've called dmu_tx_hold_object(tx, db->db_object)). 639 */ 640 void dmu_buf_will_dirty(dmu_buf_t *db, dmu_tx_t *tx); 641 642 /* 643 * Tells if the given dbuf is freeable. 644 */ 645 boolean_t dmu_buf_freeable(dmu_buf_t *); 646 647 /* 648 * You must create a transaction, then hold the objects which you will 649 * (or might) modify as part of this transaction. Then you must assign 650 * the transaction to a transaction group. Once the transaction has 651 * been assigned, you can modify buffers which belong to held objects as 652 * part of this transaction. You can't modify buffers before the 653 * transaction has been assigned; you can't modify buffers which don't 654 * belong to objects which this transaction holds; you can't hold 655 * objects once the transaction has been assigned. You may hold an 656 * object which you are going to free (with dmu_object_free()), but you 657 * don't have to. 658 * 659 * You can abort the transaction before it has been assigned. 660 * 661 * Note that you may hold buffers (with dmu_buf_hold) at any time, 662 * regardless of transaction state. 663 */ 664 665 #define DMU_NEW_OBJECT (-1ULL) 666 #define DMU_OBJECT_END (-1ULL) 667 668 dmu_tx_t *dmu_tx_create(objset_t *os); 669 void dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len); 670 void dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off, 671 uint64_t len); 672 void dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name); 673 void dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object); 674 void dmu_tx_hold_spill(dmu_tx_t *tx, uint64_t object); 675 void dmu_tx_hold_sa(dmu_tx_t *tx, struct sa_handle *hdl, boolean_t may_grow); 676 void dmu_tx_hold_sa_create(dmu_tx_t *tx, int total_size); 677 void dmu_tx_abort(dmu_tx_t *tx); 678 int dmu_tx_assign(dmu_tx_t *tx, enum txg_how txg_how); 679 void dmu_tx_wait(dmu_tx_t *tx); 680 void dmu_tx_commit(dmu_tx_t *tx); 681 void dmu_tx_mark_netfree(dmu_tx_t *tx); 682 683 /* 684 * To register a commit callback, dmu_tx_callback_register() must be called. 685 * 686 * dcb_data is a pointer to caller private data that is passed on as a 687 * callback parameter. The caller is responsible for properly allocating and 688 * freeing it. 689 * 690 * When registering a callback, the transaction must be already created, but 691 * it cannot be committed or aborted. It can be assigned to a txg or not. 692 * 693 * The callback will be called after the transaction has been safely written 694 * to stable storage and will also be called if the dmu_tx is aborted. 695 * If there is any error which prevents the transaction from being committed to 696 * disk, the callback will be called with a value of error != 0. 697 */ 698 typedef void dmu_tx_callback_func_t(void *dcb_data, int error); 699 700 void dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *dcb_func, 701 void *dcb_data); 702 703 /* 704 * Free up the data blocks for a defined range of a file. If size is 705 * -1, the range from offset to end-of-file is freed. 706 */ 707 int dmu_free_range(objset_t *os, uint64_t object, uint64_t offset, 708 uint64_t size, dmu_tx_t *tx); 709 int dmu_free_long_range(objset_t *os, uint64_t object, uint64_t offset, 710 uint64_t size); 711 int dmu_free_long_object(objset_t *os, uint64_t object); 712 713 /* 714 * Convenience functions. 715 * 716 * Canfail routines will return 0 on success, or an errno if there is a 717 * nonrecoverable I/O error. 718 */ 719 #define DMU_READ_PREFETCH 0 /* prefetch */ 720 #define DMU_READ_NO_PREFETCH 1 /* don't prefetch */ 721 int dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 722 void *buf, uint32_t flags); 723 void dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 724 const void *buf, dmu_tx_t *tx); 725 void dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 726 dmu_tx_t *tx); 727 int dmu_read_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size); 728 int dmu_read_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size); 729 int dmu_write_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size, 730 dmu_tx_t *tx); 731 int dmu_write_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size, 732 dmu_tx_t *tx); 733 int dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset, 734 uint64_t size, struct page *pp, dmu_tx_t *tx); 735 struct arc_buf *dmu_request_arcbuf(dmu_buf_t *handle, int size); 736 void dmu_return_arcbuf(struct arc_buf *buf); 737 void dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, struct arc_buf *buf, 738 dmu_tx_t *tx); 739 int dmu_xuio_init(struct xuio *uio, int niov); 740 void dmu_xuio_fini(struct xuio *uio); 741 int dmu_xuio_add(struct xuio *uio, struct arc_buf *abuf, offset_t off, 742 size_t n); 743 int dmu_xuio_cnt(struct xuio *uio); 744 struct arc_buf *dmu_xuio_arcbuf(struct xuio *uio, int i); 745 void dmu_xuio_clear(struct xuio *uio, int i); 746 void xuio_stat_wbuf_copied(); 747 void xuio_stat_wbuf_nocopy(); 748 749 extern boolean_t zfs_prefetch_disable; 750 extern int zfs_max_recordsize; 751 752 /* 753 * Asynchronously try to read in the data. 754 */ 755 void dmu_prefetch(objset_t *os, uint64_t object, int64_t level, uint64_t offset, 756 uint64_t len, enum zio_priority pri); 757 758 typedef struct dmu_object_info { 759 /* All sizes are in bytes unless otherwise indicated. */ 760 uint32_t doi_data_block_size; 761 uint32_t doi_metadata_block_size; 762 dmu_object_type_t doi_type; 763 dmu_object_type_t doi_bonus_type; 764 uint64_t doi_bonus_size; 765 uint8_t doi_indirection; /* 2 = dnode->indirect->data */ 766 uint8_t doi_checksum; 767 uint8_t doi_compress; 768 uint8_t doi_nblkptr; 769 uint8_t doi_pad[4]; 770 uint64_t doi_physical_blocks_512; /* data + metadata, 512b blks */ 771 uint64_t doi_max_offset; 772 uint64_t doi_fill_count; /* number of non-empty blocks */ 773 } dmu_object_info_t; 774 775 typedef void arc_byteswap_func_t(void *buf, size_t size); 776 777 typedef struct dmu_object_type_info { 778 dmu_object_byteswap_t ot_byteswap; 779 boolean_t ot_metadata; 780 char *ot_name; 781 } dmu_object_type_info_t; 782 783 typedef struct dmu_object_byteswap_info { 784 arc_byteswap_func_t *ob_func; 785 char *ob_name; 786 } dmu_object_byteswap_info_t; 787 788 extern const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES]; 789 extern const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS]; 790 791 /* 792 * Get information on a DMU object. 793 * 794 * Return 0 on success or ENOENT if object is not allocated. 795 * 796 * If doi is NULL, just indicates whether the object exists. 797 */ 798 int dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi); 799 /* Like dmu_object_info, but faster if you have a held dnode in hand. */ 800 void dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi); 801 /* Like dmu_object_info, but faster if you have a held dbuf in hand. */ 802 void dmu_object_info_from_db(dmu_buf_t *db, dmu_object_info_t *doi); 803 /* 804 * Like dmu_object_info_from_db, but faster still when you only care about 805 * the size. This is specifically optimized for zfs_getattr(). 806 */ 807 void dmu_object_size_from_db(dmu_buf_t *db, uint32_t *blksize, 808 u_longlong_t *nblk512); 809 810 typedef struct dmu_objset_stats { 811 uint64_t dds_num_clones; /* number of clones of this */ 812 uint64_t dds_creation_txg; 813 uint64_t dds_guid; 814 dmu_objset_type_t dds_type; 815 uint8_t dds_is_snapshot; 816 uint8_t dds_inconsistent; 817 char dds_origin[ZFS_MAX_DATASET_NAME_LEN]; 818 } dmu_objset_stats_t; 819 820 /* 821 * Get stats on a dataset. 822 */ 823 void dmu_objset_fast_stat(objset_t *os, dmu_objset_stats_t *stat); 824 825 /* 826 * Add entries to the nvlist for all the objset's properties. See 827 * zfs_prop_table[] and zfs(1m) for details on the properties. 828 */ 829 void dmu_objset_stats(objset_t *os, struct nvlist *nv); 830 831 /* 832 * Get the space usage statistics for statvfs(). 833 * 834 * refdbytes is the amount of space "referenced" by this objset. 835 * availbytes is the amount of space available to this objset, taking 836 * into account quotas & reservations, assuming that no other objsets 837 * use the space first. These values correspond to the 'referenced' and 838 * 'available' properties, described in the zfs(1m) manpage. 839 * 840 * usedobjs and availobjs are the number of objects currently allocated, 841 * and available. 842 */ 843 void dmu_objset_space(objset_t *os, uint64_t *refdbytesp, uint64_t *availbytesp, 844 uint64_t *usedobjsp, uint64_t *availobjsp); 845 846 /* 847 * The fsid_guid is a 56-bit ID that can change to avoid collisions. 848 * (Contrast with the ds_guid which is a 64-bit ID that will never 849 * change, so there is a small probability that it will collide.) 850 */ 851 uint64_t dmu_objset_fsid_guid(objset_t *os); 852 853 /* 854 * Get the [cm]time for an objset's snapshot dir 855 */ 856 timestruc_t dmu_objset_snap_cmtime(objset_t *os); 857 858 int dmu_objset_is_snapshot(objset_t *os); 859 860 extern struct spa *dmu_objset_spa(objset_t *os); 861 extern struct zilog *dmu_objset_zil(objset_t *os); 862 extern struct dsl_pool *dmu_objset_pool(objset_t *os); 863 extern struct dsl_dataset *dmu_objset_ds(objset_t *os); 864 extern void dmu_objset_name(objset_t *os, char *buf); 865 extern dmu_objset_type_t dmu_objset_type(objset_t *os); 866 extern uint64_t dmu_objset_id(objset_t *os); 867 extern zfs_sync_type_t dmu_objset_syncprop(objset_t *os); 868 extern zfs_logbias_op_t dmu_objset_logbias(objset_t *os); 869 extern int dmu_snapshot_list_next(objset_t *os, int namelen, char *name, 870 uint64_t *id, uint64_t *offp, boolean_t *case_conflict); 871 extern int dmu_snapshot_realname(objset_t *os, char *name, char *real, 872 int maxlen, boolean_t *conflict); 873 extern int dmu_dir_list_next(objset_t *os, int namelen, char *name, 874 uint64_t *idp, uint64_t *offp); 875 876 typedef int objset_used_cb_t(dmu_object_type_t bonustype, 877 void *bonus, uint64_t *userp, uint64_t *groupp); 878 extern void dmu_objset_register_type(dmu_objset_type_t ost, 879 objset_used_cb_t *cb); 880 extern void dmu_objset_set_user(objset_t *os, void *user_ptr); 881 extern void *dmu_objset_get_user(objset_t *os); 882 883 /* 884 * Return the txg number for the given assigned transaction. 885 */ 886 uint64_t dmu_tx_get_txg(dmu_tx_t *tx); 887 888 /* 889 * Synchronous write. 890 * If a parent zio is provided this function initiates a write on the 891 * provided buffer as a child of the parent zio. 892 * In the absence of a parent zio, the write is completed synchronously. 893 * At write completion, blk is filled with the bp of the written block. 894 * Note that while the data covered by this function will be on stable 895 * storage when the write completes this new data does not become a 896 * permanent part of the file until the associated transaction commits. 897 */ 898 899 /* 900 * {zfs,zvol,ztest}_get_done() args 901 */ 902 typedef struct zgd { 903 struct zilog *zgd_zilog; 904 struct blkptr *zgd_bp; 905 dmu_buf_t *zgd_db; 906 struct rl *zgd_rl; 907 void *zgd_private; 908 } zgd_t; 909 910 typedef void dmu_sync_cb_t(zgd_t *arg, int error); 911 int dmu_sync(struct zio *zio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd); 912 913 /* 914 * Find the next hole or data block in file starting at *off 915 * Return found offset in *off. Return ESRCH for end of file. 916 */ 917 int dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole, 918 uint64_t *off); 919 920 /* 921 * Check if a DMU object has any dirty blocks. If so, sync out 922 * all pending transaction groups. Otherwise, this function 923 * does not alter DMU state. This could be improved to only sync 924 * out the necessary transaction groups for this particular 925 * object. 926 */ 927 int dmu_object_wait_synced(objset_t *os, uint64_t object); 928 929 /* 930 * Initial setup and final teardown. 931 */ 932 extern void dmu_init(void); 933 extern void dmu_fini(void); 934 935 typedef void (*dmu_traverse_cb_t)(objset_t *os, void *arg, struct blkptr *bp, 936 uint64_t object, uint64_t offset, int len); 937 void dmu_traverse_objset(objset_t *os, uint64_t txg_start, 938 dmu_traverse_cb_t cb, void *arg); 939 940 int dmu_diff(const char *tosnap_name, const char *fromsnap_name, 941 struct vnode *vp, offset_t *offp); 942 943 /* CRC64 table */ 944 #define ZFS_CRC64_POLY 0xC96C5795D7870F42ULL /* ECMA-182, reflected form */ 945 extern uint64_t zfs_crc64_table[256]; 946 947 extern int zfs_mdcomp_disable; 948 949 #ifdef __cplusplus 950 } 951 #endif 952 953 #endif /* _SYS_DMU_H */ 954