1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 24 * Copyright (c) 2011, 2017 by Delphix. All rights reserved. 25 * Copyright 2011 Nexenta Systems, Inc. All rights reserved. 26 * Copyright (c) 2012, Joyent, Inc. All rights reserved. 27 * Copyright 2013 DEY Storage Systems, Inc. 28 * Copyright 2014 HybridCluster. All rights reserved. 29 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. 30 * Copyright 2013 Saso Kiselkov. All rights reserved. 31 * Copyright (c) 2014 Integros [integros.com] 32 */ 33 34 /* Portions Copyright 2010 Robert Milkowski */ 35 36 #ifndef _SYS_DMU_H 37 #define _SYS_DMU_H 38 39 /* 40 * This file describes the interface that the DMU provides for its 41 * consumers. 42 * 43 * The DMU also interacts with the SPA. That interface is described in 44 * dmu_spa.h. 45 */ 46 47 #include <sys/zfs_context.h> 48 #include <sys/inttypes.h> 49 #include <sys/cred.h> 50 #include <sys/fs/zfs.h> 51 #include <sys/zio_compress.h> 52 #include <sys/zio_priority.h> 53 54 #ifdef __cplusplus 55 extern "C" { 56 #endif 57 58 struct uio; 59 struct xuio; 60 struct page; 61 struct vnode; 62 struct spa; 63 struct zilog; 64 struct zio; 65 struct blkptr; 66 struct zap_cursor; 67 struct dsl_dataset; 68 struct dsl_pool; 69 struct dnode; 70 struct drr_begin; 71 struct drr_end; 72 struct zbookmark_phys; 73 struct spa; 74 struct nvlist; 75 struct arc_buf; 76 struct zio_prop; 77 struct sa_handle; 78 79 typedef struct objset objset_t; 80 typedef struct dmu_tx dmu_tx_t; 81 typedef struct dsl_dir dsl_dir_t; 82 typedef struct dnode dnode_t; 83 84 typedef enum dmu_object_byteswap { 85 DMU_BSWAP_UINT8, 86 DMU_BSWAP_UINT16, 87 DMU_BSWAP_UINT32, 88 DMU_BSWAP_UINT64, 89 DMU_BSWAP_ZAP, 90 DMU_BSWAP_DNODE, 91 DMU_BSWAP_OBJSET, 92 DMU_BSWAP_ZNODE, 93 DMU_BSWAP_OLDACL, 94 DMU_BSWAP_ACL, 95 /* 96 * Allocating a new byteswap type number makes the on-disk format 97 * incompatible with any other format that uses the same number. 98 * 99 * Data can usually be structured to work with one of the 100 * DMU_BSWAP_UINT* or DMU_BSWAP_ZAP types. 101 */ 102 DMU_BSWAP_NUMFUNCS 103 } dmu_object_byteswap_t; 104 105 #define DMU_OT_NEWTYPE 0x80 106 #define DMU_OT_METADATA 0x40 107 #define DMU_OT_BYTESWAP_MASK 0x3f 108 109 /* 110 * Defines a uint8_t object type. Object types specify if the data 111 * in the object is metadata (boolean) and how to byteswap the data 112 * (dmu_object_byteswap_t). 113 */ 114 #define DMU_OT(byteswap, metadata) \ 115 (DMU_OT_NEWTYPE | \ 116 ((metadata) ? DMU_OT_METADATA : 0) | \ 117 ((byteswap) & DMU_OT_BYTESWAP_MASK)) 118 119 #define DMU_OT_IS_VALID(ot) (((ot) & DMU_OT_NEWTYPE) ? \ 120 ((ot) & DMU_OT_BYTESWAP_MASK) < DMU_BSWAP_NUMFUNCS : \ 121 (ot) < DMU_OT_NUMTYPES) 122 123 #define DMU_OT_IS_METADATA(ot) (((ot) & DMU_OT_NEWTYPE) ? \ 124 ((ot) & DMU_OT_METADATA) : \ 125 dmu_ot[(ot)].ot_metadata) 126 127 /* 128 * These object types use bp_fill != 1 for their L0 bp's. Therefore they can't 129 * have their data embedded (i.e. use a BP_IS_EMBEDDED() bp), because bp_fill 130 * is repurposed for embedded BPs. 131 */ 132 #define DMU_OT_HAS_FILL(ot) \ 133 ((ot) == DMU_OT_DNODE || (ot) == DMU_OT_OBJSET) 134 135 #define DMU_OT_BYTESWAP(ot) (((ot) & DMU_OT_NEWTYPE) ? \ 136 ((ot) & DMU_OT_BYTESWAP_MASK) : \ 137 dmu_ot[(ot)].ot_byteswap) 138 139 typedef enum dmu_object_type { 140 DMU_OT_NONE, 141 /* general: */ 142 DMU_OT_OBJECT_DIRECTORY, /* ZAP */ 143 DMU_OT_OBJECT_ARRAY, /* UINT64 */ 144 DMU_OT_PACKED_NVLIST, /* UINT8 (XDR by nvlist_pack/unpack) */ 145 DMU_OT_PACKED_NVLIST_SIZE, /* UINT64 */ 146 DMU_OT_BPOBJ, /* UINT64 */ 147 DMU_OT_BPOBJ_HDR, /* UINT64 */ 148 /* spa: */ 149 DMU_OT_SPACE_MAP_HEADER, /* UINT64 */ 150 DMU_OT_SPACE_MAP, /* UINT64 */ 151 /* zil: */ 152 DMU_OT_INTENT_LOG, /* UINT64 */ 153 /* dmu: */ 154 DMU_OT_DNODE, /* DNODE */ 155 DMU_OT_OBJSET, /* OBJSET */ 156 /* dsl: */ 157 DMU_OT_DSL_DIR, /* UINT64 */ 158 DMU_OT_DSL_DIR_CHILD_MAP, /* ZAP */ 159 DMU_OT_DSL_DS_SNAP_MAP, /* ZAP */ 160 DMU_OT_DSL_PROPS, /* ZAP */ 161 DMU_OT_DSL_DATASET, /* UINT64 */ 162 /* zpl: */ 163 DMU_OT_ZNODE, /* ZNODE */ 164 DMU_OT_OLDACL, /* Old ACL */ 165 DMU_OT_PLAIN_FILE_CONTENTS, /* UINT8 */ 166 DMU_OT_DIRECTORY_CONTENTS, /* ZAP */ 167 DMU_OT_MASTER_NODE, /* ZAP */ 168 DMU_OT_UNLINKED_SET, /* ZAP */ 169 /* zvol: */ 170 DMU_OT_ZVOL, /* UINT8 */ 171 DMU_OT_ZVOL_PROP, /* ZAP */ 172 /* other; for testing only! */ 173 DMU_OT_PLAIN_OTHER, /* UINT8 */ 174 DMU_OT_UINT64_OTHER, /* UINT64 */ 175 DMU_OT_ZAP_OTHER, /* ZAP */ 176 /* new object types: */ 177 DMU_OT_ERROR_LOG, /* ZAP */ 178 DMU_OT_SPA_HISTORY, /* UINT8 */ 179 DMU_OT_SPA_HISTORY_OFFSETS, /* spa_his_phys_t */ 180 DMU_OT_POOL_PROPS, /* ZAP */ 181 DMU_OT_DSL_PERMS, /* ZAP */ 182 DMU_OT_ACL, /* ACL */ 183 DMU_OT_SYSACL, /* SYSACL */ 184 DMU_OT_FUID, /* FUID table (Packed NVLIST UINT8) */ 185 DMU_OT_FUID_SIZE, /* FUID table size UINT64 */ 186 DMU_OT_NEXT_CLONES, /* ZAP */ 187 DMU_OT_SCAN_QUEUE, /* ZAP */ 188 DMU_OT_USERGROUP_USED, /* ZAP */ 189 DMU_OT_USERGROUP_QUOTA, /* ZAP */ 190 DMU_OT_USERREFS, /* ZAP */ 191 DMU_OT_DDT_ZAP, /* ZAP */ 192 DMU_OT_DDT_STATS, /* ZAP */ 193 DMU_OT_SA, /* System attr */ 194 DMU_OT_SA_MASTER_NODE, /* ZAP */ 195 DMU_OT_SA_ATTR_REGISTRATION, /* ZAP */ 196 DMU_OT_SA_ATTR_LAYOUTS, /* ZAP */ 197 DMU_OT_SCAN_XLATE, /* ZAP */ 198 DMU_OT_DEDUP, /* fake dedup BP from ddt_bp_create() */ 199 DMU_OT_DEADLIST, /* ZAP */ 200 DMU_OT_DEADLIST_HDR, /* UINT64 */ 201 DMU_OT_DSL_CLONES, /* ZAP */ 202 DMU_OT_BPOBJ_SUBOBJ, /* UINT64 */ 203 /* 204 * Do not allocate new object types here. Doing so makes the on-disk 205 * format incompatible with any other format that uses the same object 206 * type number. 207 * 208 * When creating an object which does not have one of the above types 209 * use the DMU_OTN_* type with the correct byteswap and metadata 210 * values. 211 * 212 * The DMU_OTN_* types do not have entries in the dmu_ot table, 213 * use the DMU_OT_IS_METDATA() and DMU_OT_BYTESWAP() macros instead 214 * of indexing into dmu_ot directly (this works for both DMU_OT_* types 215 * and DMU_OTN_* types). 216 */ 217 DMU_OT_NUMTYPES, 218 219 /* 220 * Names for valid types declared with DMU_OT(). 221 */ 222 DMU_OTN_UINT8_DATA = DMU_OT(DMU_BSWAP_UINT8, B_FALSE), 223 DMU_OTN_UINT8_METADATA = DMU_OT(DMU_BSWAP_UINT8, B_TRUE), 224 DMU_OTN_UINT16_DATA = DMU_OT(DMU_BSWAP_UINT16, B_FALSE), 225 DMU_OTN_UINT16_METADATA = DMU_OT(DMU_BSWAP_UINT16, B_TRUE), 226 DMU_OTN_UINT32_DATA = DMU_OT(DMU_BSWAP_UINT32, B_FALSE), 227 DMU_OTN_UINT32_METADATA = DMU_OT(DMU_BSWAP_UINT32, B_TRUE), 228 DMU_OTN_UINT64_DATA = DMU_OT(DMU_BSWAP_UINT64, B_FALSE), 229 DMU_OTN_UINT64_METADATA = DMU_OT(DMU_BSWAP_UINT64, B_TRUE), 230 DMU_OTN_ZAP_DATA = DMU_OT(DMU_BSWAP_ZAP, B_FALSE), 231 DMU_OTN_ZAP_METADATA = DMU_OT(DMU_BSWAP_ZAP, B_TRUE), 232 } dmu_object_type_t; 233 234 /* 235 * These flags are intended to be used to specify the "txg_how" 236 * parameter when calling the dmu_tx_assign() function. See the comment 237 * above dmu_tx_assign() for more details on the meaning of these flags. 238 */ 239 #define TXG_NOWAIT (0ULL) 240 #define TXG_WAIT (1ULL<<0) 241 #define TXG_NOTHROTTLE (1ULL<<1) 242 243 void byteswap_uint64_array(void *buf, size_t size); 244 void byteswap_uint32_array(void *buf, size_t size); 245 void byteswap_uint16_array(void *buf, size_t size); 246 void byteswap_uint8_array(void *buf, size_t size); 247 void zap_byteswap(void *buf, size_t size); 248 void zfs_oldacl_byteswap(void *buf, size_t size); 249 void zfs_acl_byteswap(void *buf, size_t size); 250 void zfs_znode_byteswap(void *buf, size_t size); 251 252 #define DS_FIND_SNAPSHOTS (1<<0) 253 #define DS_FIND_CHILDREN (1<<1) 254 #define DS_FIND_SERIALIZE (1<<2) 255 256 /* 257 * The maximum number of bytes that can be accessed as part of one 258 * operation, including metadata. 259 */ 260 #define DMU_MAX_ACCESS (32 * 1024 * 1024) /* 32MB */ 261 #define DMU_MAX_DELETEBLKCNT (20480) /* ~5MB of indirect blocks */ 262 263 #define DMU_USERUSED_OBJECT (-1ULL) 264 #define DMU_GROUPUSED_OBJECT (-2ULL) 265 266 /* 267 * artificial blkids for bonus buffer and spill blocks 268 */ 269 #define DMU_BONUS_BLKID (-1ULL) 270 #define DMU_SPILL_BLKID (-2ULL) 271 /* 272 * Public routines to create, destroy, open, and close objsets. 273 */ 274 int dmu_objset_hold(const char *name, void *tag, objset_t **osp); 275 int dmu_objset_own(const char *name, dmu_objset_type_t type, 276 boolean_t readonly, void *tag, objset_t **osp); 277 void dmu_objset_rele(objset_t *os, void *tag); 278 void dmu_objset_disown(objset_t *os, void *tag); 279 int dmu_objset_open_ds(struct dsl_dataset *ds, objset_t **osp); 280 281 void dmu_objset_evict_dbufs(objset_t *os); 282 int dmu_objset_create(const char *name, dmu_objset_type_t type, uint64_t flags, 283 void (*func)(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx), void *arg); 284 int dmu_objset_clone(const char *name, const char *origin); 285 int dsl_destroy_snapshots_nvl(struct nvlist *snaps, boolean_t defer, 286 struct nvlist *errlist); 287 int dmu_objset_snapshot_one(const char *fsname, const char *snapname); 288 int dmu_objset_snapshot_tmp(const char *, const char *, int); 289 int dmu_objset_find(char *name, int func(const char *, void *), void *arg, 290 int flags); 291 void dmu_objset_byteswap(void *buf, size_t size); 292 int dsl_dataset_rename_snapshot(const char *fsname, 293 const char *oldsnapname, const char *newsnapname, boolean_t recursive); 294 int dmu_objset_remap_indirects(const char *fsname); 295 296 typedef struct dmu_buf { 297 uint64_t db_object; /* object that this buffer is part of */ 298 uint64_t db_offset; /* byte offset in this object */ 299 uint64_t db_size; /* size of buffer in bytes */ 300 void *db_data; /* data in buffer */ 301 } dmu_buf_t; 302 303 /* 304 * The names of zap entries in the DIRECTORY_OBJECT of the MOS. 305 */ 306 #define DMU_POOL_DIRECTORY_OBJECT 1 307 #define DMU_POOL_CONFIG "config" 308 #define DMU_POOL_FEATURES_FOR_WRITE "features_for_write" 309 #define DMU_POOL_FEATURES_FOR_READ "features_for_read" 310 #define DMU_POOL_FEATURE_DESCRIPTIONS "feature_descriptions" 311 #define DMU_POOL_FEATURE_ENABLED_TXG "feature_enabled_txg" 312 #define DMU_POOL_ROOT_DATASET "root_dataset" 313 #define DMU_POOL_SYNC_BPOBJ "sync_bplist" 314 #define DMU_POOL_ERRLOG_SCRUB "errlog_scrub" 315 #define DMU_POOL_ERRLOG_LAST "errlog_last" 316 #define DMU_POOL_SPARES "spares" 317 #define DMU_POOL_DEFLATE "deflate" 318 #define DMU_POOL_HISTORY "history" 319 #define DMU_POOL_PROPS "pool_props" 320 #define DMU_POOL_L2CACHE "l2cache" 321 #define DMU_POOL_TMP_USERREFS "tmp_userrefs" 322 #define DMU_POOL_DDT "DDT-%s-%s-%s" 323 #define DMU_POOL_DDT_STATS "DDT-statistics" 324 #define DMU_POOL_CREATION_VERSION "creation_version" 325 #define DMU_POOL_SCAN "scan" 326 #define DMU_POOL_FREE_BPOBJ "free_bpobj" 327 #define DMU_POOL_BPTREE_OBJ "bptree_obj" 328 #define DMU_POOL_EMPTY_BPOBJ "empty_bpobj" 329 #define DMU_POOL_CHECKSUM_SALT "org.illumos:checksum_salt" 330 #define DMU_POOL_VDEV_ZAP_MAP "com.delphix:vdev_zap_map" 331 #define DMU_POOL_REMOVING "com.delphix:removing" 332 #define DMU_POOL_OBSOLETE_BPOBJ "com.delphix:obsolete_bpobj" 333 #define DMU_POOL_CONDENSING_INDIRECT "com.delphix:condensing_indirect" 334 #define DMU_POOL_ZPOOL_CHECKPOINT "com.delphix:zpool_checkpoint" 335 336 /* 337 * Allocate an object from this objset. The range of object numbers 338 * available is (0, DN_MAX_OBJECT). Object 0 is the meta-dnode. 339 * 340 * The transaction must be assigned to a txg. The newly allocated 341 * object will be "held" in the transaction (ie. you can modify the 342 * newly allocated object in this transaction). 343 * 344 * dmu_object_alloc() chooses an object and returns it in *objectp. 345 * 346 * dmu_object_claim() allocates a specific object number. If that 347 * number is already allocated, it fails and returns EEXIST. 348 * 349 * Return 0 on success, or ENOSPC or EEXIST as specified above. 350 */ 351 uint64_t dmu_object_alloc(objset_t *os, dmu_object_type_t ot, 352 int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx); 353 int dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot, 354 int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx); 355 int dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot, 356 int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *txp); 357 358 /* 359 * Free an object from this objset. 360 * 361 * The object's data will be freed as well (ie. you don't need to call 362 * dmu_free(object, 0, -1, tx)). 363 * 364 * The object need not be held in the transaction. 365 * 366 * If there are any holds on this object's buffers (via dmu_buf_hold()), 367 * or tx holds on the object (via dmu_tx_hold_object()), you can not 368 * free it; it fails and returns EBUSY. 369 * 370 * If the object is not allocated, it fails and returns ENOENT. 371 * 372 * Return 0 on success, or EBUSY or ENOENT as specified above. 373 */ 374 int dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx); 375 376 /* 377 * Find the next allocated or free object. 378 * 379 * The objectp parameter is in-out. It will be updated to be the next 380 * object which is allocated. Ignore objects which have not been 381 * modified since txg. 382 * 383 * XXX Can only be called on a objset with no dirty data. 384 * 385 * Returns 0 on success, or ENOENT if there are no more objects. 386 */ 387 int dmu_object_next(objset_t *os, uint64_t *objectp, 388 boolean_t hole, uint64_t txg); 389 390 /* 391 * Set the data blocksize for an object. 392 * 393 * The object cannot have any blocks allcated beyond the first. If 394 * the first block is allocated already, the new size must be greater 395 * than the current block size. If these conditions are not met, 396 * ENOTSUP will be returned. 397 * 398 * Returns 0 on success, or EBUSY if there are any holds on the object 399 * contents, or ENOTSUP as described above. 400 */ 401 int dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size, 402 int ibs, dmu_tx_t *tx); 403 404 /* 405 * Set the checksum property on a dnode. The new checksum algorithm will 406 * apply to all newly written blocks; existing blocks will not be affected. 407 */ 408 void dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum, 409 dmu_tx_t *tx); 410 411 /* 412 * Set the compress property on a dnode. The new compression algorithm will 413 * apply to all newly written blocks; existing blocks will not be affected. 414 */ 415 void dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress, 416 dmu_tx_t *tx); 417 418 int dmu_object_remap_indirects(objset_t *os, uint64_t object, uint64_t txg); 419 420 void 421 dmu_write_embedded(objset_t *os, uint64_t object, uint64_t offset, 422 void *data, uint8_t etype, uint8_t comp, int uncompressed_size, 423 int compressed_size, int byteorder, dmu_tx_t *tx); 424 425 /* 426 * Decide how to write a block: checksum, compression, number of copies, etc. 427 */ 428 #define WP_NOFILL 0x1 429 #define WP_DMU_SYNC 0x2 430 #define WP_SPILL 0x4 431 432 void dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp, 433 struct zio_prop *zp); 434 /* 435 * The bonus data is accessed more or less like a regular buffer. 436 * You must dmu_bonus_hold() to get the buffer, which will give you a 437 * dmu_buf_t with db_offset==-1ULL, and db_size = the size of the bonus 438 * data. As with any normal buffer, you must call dmu_buf_will_dirty() 439 * before modifying it, and the 440 * object must be held in an assigned transaction before calling 441 * dmu_buf_will_dirty. You may use dmu_buf_set_user() on the bonus 442 * buffer as well. You must release your hold with dmu_buf_rele(). 443 * 444 * Returns ENOENT, EIO, or 0. 445 */ 446 int dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **); 447 int dmu_bonus_max(void); 448 int dmu_set_bonus(dmu_buf_t *, int, dmu_tx_t *); 449 int dmu_set_bonustype(dmu_buf_t *, dmu_object_type_t, dmu_tx_t *); 450 dmu_object_type_t dmu_get_bonustype(dmu_buf_t *); 451 int dmu_rm_spill(objset_t *, uint64_t, dmu_tx_t *); 452 453 /* 454 * Special spill buffer support used by "SA" framework 455 */ 456 457 int dmu_spill_hold_by_bonus(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp); 458 int dmu_spill_hold_by_dnode(dnode_t *dn, uint32_t flags, 459 void *tag, dmu_buf_t **dbp); 460 int dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp); 461 462 /* 463 * Obtain the DMU buffer from the specified object which contains the 464 * specified offset. dmu_buf_hold() puts a "hold" on the buffer, so 465 * that it will remain in memory. You must release the hold with 466 * dmu_buf_rele(). You musn't access the dmu_buf_t after releasing your 467 * hold. You must have a hold on any dmu_buf_t* you pass to the DMU. 468 * 469 * You must call dmu_buf_read, dmu_buf_will_dirty, or dmu_buf_will_fill 470 * on the returned buffer before reading or writing the buffer's 471 * db_data. The comments for those routines describe what particular 472 * operations are valid after calling them. 473 * 474 * The object number must be a valid, allocated object number. 475 */ 476 int dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset, 477 void *tag, dmu_buf_t **, int flags); 478 int dmu_buf_hold_by_dnode(dnode_t *dn, uint64_t offset, 479 void *tag, dmu_buf_t **dbp, int flags); 480 481 /* 482 * Add a reference to a dmu buffer that has already been held via 483 * dmu_buf_hold() in the current context. 484 */ 485 void dmu_buf_add_ref(dmu_buf_t *db, void* tag); 486 487 /* 488 * Attempt to add a reference to a dmu buffer that is in an unknown state, 489 * using a pointer that may have been invalidated by eviction processing. 490 * The request will succeed if the passed in dbuf still represents the 491 * same os/object/blkid, is ineligible for eviction, and has at least 492 * one hold by a user other than the syncer. 493 */ 494 boolean_t dmu_buf_try_add_ref(dmu_buf_t *, objset_t *os, uint64_t object, 495 uint64_t blkid, void *tag); 496 497 void dmu_buf_rele(dmu_buf_t *db, void *tag); 498 uint64_t dmu_buf_refcount(dmu_buf_t *db); 499 500 /* 501 * dmu_buf_hold_array holds the DMU buffers which contain all bytes in a 502 * range of an object. A pointer to an array of dmu_buf_t*'s is 503 * returned (in *dbpp). 504 * 505 * dmu_buf_rele_array releases the hold on an array of dmu_buf_t*'s, and 506 * frees the array. The hold on the array of buffers MUST be released 507 * with dmu_buf_rele_array. You can NOT release the hold on each buffer 508 * individually with dmu_buf_rele. 509 */ 510 int dmu_buf_hold_array_by_bonus(dmu_buf_t *db, uint64_t offset, 511 uint64_t length, boolean_t read, void *tag, 512 int *numbufsp, dmu_buf_t ***dbpp); 513 void dmu_buf_rele_array(dmu_buf_t **, int numbufs, void *tag); 514 515 typedef void dmu_buf_evict_func_t(void *user_ptr); 516 517 /* 518 * A DMU buffer user object may be associated with a dbuf for the 519 * duration of its lifetime. This allows the user of a dbuf (client) 520 * to attach private data to a dbuf (e.g. in-core only data such as a 521 * dnode_children_t, zap_t, or zap_leaf_t) and be optionally notified 522 * when that dbuf has been evicted. Clients typically respond to the 523 * eviction notification by freeing their private data, thus ensuring 524 * the same lifetime for both dbuf and private data. 525 * 526 * The mapping from a dmu_buf_user_t to any client private data is the 527 * client's responsibility. All current consumers of the API with private 528 * data embed a dmu_buf_user_t as the first member of the structure for 529 * their private data. This allows conversions between the two types 530 * with a simple cast. Since the DMU buf user API never needs access 531 * to the private data, other strategies can be employed if necessary 532 * or convenient for the client (e.g. using container_of() to do the 533 * conversion for private data that cannot have the dmu_buf_user_t as 534 * its first member). 535 * 536 * Eviction callbacks are executed without the dbuf mutex held or any 537 * other type of mechanism to guarantee that the dbuf is still available. 538 * For this reason, users must assume the dbuf has already been freed 539 * and not reference the dbuf from the callback context. 540 * 541 * Users requesting "immediate eviction" are notified as soon as the dbuf 542 * is only referenced by dirty records (dirties == holds). Otherwise the 543 * notification occurs after eviction processing for the dbuf begins. 544 */ 545 typedef struct dmu_buf_user { 546 /* 547 * Asynchronous user eviction callback state. 548 */ 549 taskq_ent_t dbu_tqent; 550 551 /* 552 * This instance's eviction function pointers. 553 * 554 * dbu_evict_func_sync is called synchronously and then 555 * dbu_evict_func_async is executed asynchronously on a taskq. 556 */ 557 dmu_buf_evict_func_t *dbu_evict_func_sync; 558 dmu_buf_evict_func_t *dbu_evict_func_async; 559 #ifdef ZFS_DEBUG 560 /* 561 * Pointer to user's dbuf pointer. NULL for clients that do 562 * not associate a dbuf with their user data. 563 * 564 * The dbuf pointer is cleared upon eviction so as to catch 565 * use-after-evict bugs in clients. 566 */ 567 dmu_buf_t **dbu_clear_on_evict_dbufp; 568 #endif 569 } dmu_buf_user_t; 570 571 /* 572 * Initialize the given dmu_buf_user_t instance with the eviction function 573 * evict_func, to be called when the user is evicted. 574 * 575 * NOTE: This function should only be called once on a given dmu_buf_user_t. 576 * To allow enforcement of this, dbu must already be zeroed on entry. 577 */ 578 /*ARGSUSED*/ 579 inline void 580 dmu_buf_init_user(dmu_buf_user_t *dbu, dmu_buf_evict_func_t *evict_func_sync, 581 dmu_buf_evict_func_t *evict_func_async, dmu_buf_t **clear_on_evict_dbufp) 582 { 583 ASSERT(dbu->dbu_evict_func_sync == NULL); 584 ASSERT(dbu->dbu_evict_func_async == NULL); 585 586 /* must have at least one evict func */ 587 IMPLY(evict_func_sync == NULL, evict_func_async != NULL); 588 dbu->dbu_evict_func_sync = evict_func_sync; 589 dbu->dbu_evict_func_async = evict_func_async; 590 #ifdef ZFS_DEBUG 591 dbu->dbu_clear_on_evict_dbufp = clear_on_evict_dbufp; 592 #endif 593 } 594 595 /* 596 * Attach user data to a dbuf and mark it for normal (when the dbuf's 597 * data is cleared or its reference count goes to zero) eviction processing. 598 * 599 * Returns NULL on success, or the existing user if another user currently 600 * owns the buffer. 601 */ 602 void *dmu_buf_set_user(dmu_buf_t *db, dmu_buf_user_t *user); 603 604 /* 605 * Attach user data to a dbuf and mark it for immediate (its dirty and 606 * reference counts are equal) eviction processing. 607 * 608 * Returns NULL on success, or the existing user if another user currently 609 * owns the buffer. 610 */ 611 void *dmu_buf_set_user_ie(dmu_buf_t *db, dmu_buf_user_t *user); 612 613 /* 614 * Replace the current user of a dbuf. 615 * 616 * If given the current user of a dbuf, replaces the dbuf's user with 617 * "new_user" and returns the user data pointer that was replaced. 618 * Otherwise returns the current, and unmodified, dbuf user pointer. 619 */ 620 void *dmu_buf_replace_user(dmu_buf_t *db, 621 dmu_buf_user_t *old_user, dmu_buf_user_t *new_user); 622 623 /* 624 * Remove the specified user data for a DMU buffer. 625 * 626 * Returns the user that was removed on success, or the current user if 627 * another user currently owns the buffer. 628 */ 629 void *dmu_buf_remove_user(dmu_buf_t *db, dmu_buf_user_t *user); 630 631 /* 632 * Returns the user data (dmu_buf_user_t *) associated with this dbuf. 633 */ 634 void *dmu_buf_get_user(dmu_buf_t *db); 635 636 objset_t *dmu_buf_get_objset(dmu_buf_t *db); 637 dnode_t *dmu_buf_dnode_enter(dmu_buf_t *db); 638 void dmu_buf_dnode_exit(dmu_buf_t *db); 639 640 /* Block until any in-progress dmu buf user evictions complete. */ 641 void dmu_buf_user_evict_wait(void); 642 643 /* 644 * Returns the blkptr associated with this dbuf, or NULL if not set. 645 */ 646 struct blkptr *dmu_buf_get_blkptr(dmu_buf_t *db); 647 648 /* 649 * Indicate that you are going to modify the buffer's data (db_data). 650 * 651 * The transaction (tx) must be assigned to a txg (ie. you've called 652 * dmu_tx_assign()). The buffer's object must be held in the tx 653 * (ie. you've called dmu_tx_hold_object(tx, db->db_object)). 654 */ 655 void dmu_buf_will_dirty(dmu_buf_t *db, dmu_tx_t *tx); 656 657 /* 658 * You must create a transaction, then hold the objects which you will 659 * (or might) modify as part of this transaction. Then you must assign 660 * the transaction to a transaction group. Once the transaction has 661 * been assigned, you can modify buffers which belong to held objects as 662 * part of this transaction. You can't modify buffers before the 663 * transaction has been assigned; you can't modify buffers which don't 664 * belong to objects which this transaction holds; you can't hold 665 * objects once the transaction has been assigned. You may hold an 666 * object which you are going to free (with dmu_object_free()), but you 667 * don't have to. 668 * 669 * You can abort the transaction before it has been assigned. 670 * 671 * Note that you may hold buffers (with dmu_buf_hold) at any time, 672 * regardless of transaction state. 673 */ 674 675 #define DMU_NEW_OBJECT (-1ULL) 676 #define DMU_OBJECT_END (-1ULL) 677 678 dmu_tx_t *dmu_tx_create(objset_t *os); 679 void dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len); 680 void dmu_tx_hold_write_by_dnode(dmu_tx_t *tx, dnode_t *dn, uint64_t off, 681 int len); 682 void dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off, 683 uint64_t len); 684 void dmu_tx_hold_free_by_dnode(dmu_tx_t *tx, dnode_t *dn, uint64_t off, 685 uint64_t len); 686 void dmu_tx_hold_remap_l1indirect(dmu_tx_t *tx, uint64_t object); 687 void dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, const char *name); 688 void dmu_tx_hold_zap_by_dnode(dmu_tx_t *tx, dnode_t *dn, int add, 689 const char *name); 690 void dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object); 691 void dmu_tx_hold_bonus_by_dnode(dmu_tx_t *tx, dnode_t *dn); 692 void dmu_tx_hold_spill(dmu_tx_t *tx, uint64_t object); 693 void dmu_tx_hold_sa(dmu_tx_t *tx, struct sa_handle *hdl, boolean_t may_grow); 694 void dmu_tx_hold_sa_create(dmu_tx_t *tx, int total_size); 695 void dmu_tx_abort(dmu_tx_t *tx); 696 int dmu_tx_assign(dmu_tx_t *tx, uint64_t txg_how); 697 void dmu_tx_wait(dmu_tx_t *tx); 698 void dmu_tx_commit(dmu_tx_t *tx); 699 void dmu_tx_mark_netfree(dmu_tx_t *tx); 700 701 /* 702 * To register a commit callback, dmu_tx_callback_register() must be called. 703 * 704 * dcb_data is a pointer to caller private data that is passed on as a 705 * callback parameter. The caller is responsible for properly allocating and 706 * freeing it. 707 * 708 * When registering a callback, the transaction must be already created, but 709 * it cannot be committed or aborted. It can be assigned to a txg or not. 710 * 711 * The callback will be called after the transaction has been safely written 712 * to stable storage and will also be called if the dmu_tx is aborted. 713 * If there is any error which prevents the transaction from being committed to 714 * disk, the callback will be called with a value of error != 0. 715 */ 716 typedef void dmu_tx_callback_func_t(void *dcb_data, int error); 717 718 void dmu_tx_callback_register(dmu_tx_t *tx, dmu_tx_callback_func_t *dcb_func, 719 void *dcb_data); 720 721 /* 722 * Free up the data blocks for a defined range of a file. If size is 723 * -1, the range from offset to end-of-file is freed. 724 */ 725 int dmu_free_range(objset_t *os, uint64_t object, uint64_t offset, 726 uint64_t size, dmu_tx_t *tx); 727 int dmu_free_long_range(objset_t *os, uint64_t object, uint64_t offset, 728 uint64_t size); 729 int dmu_free_long_object(objset_t *os, uint64_t object); 730 731 /* 732 * Convenience functions. 733 * 734 * Canfail routines will return 0 on success, or an errno if there is a 735 * nonrecoverable I/O error. 736 */ 737 #define DMU_READ_PREFETCH 0 /* prefetch */ 738 #define DMU_READ_NO_PREFETCH 1 /* don't prefetch */ 739 int dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 740 void *buf, uint32_t flags); 741 int dmu_read_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size, void *buf, 742 uint32_t flags); 743 void dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 744 const void *buf, dmu_tx_t *tx); 745 void dmu_write_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size, 746 const void *buf, dmu_tx_t *tx); 747 void dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, 748 dmu_tx_t *tx); 749 int dmu_read_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size); 750 int dmu_read_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size); 751 int dmu_write_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size, 752 dmu_tx_t *tx); 753 int dmu_write_uio_dbuf(dmu_buf_t *zdb, struct uio *uio, uint64_t size, 754 dmu_tx_t *tx); 755 int dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset, 756 uint64_t size, struct page *pp, dmu_tx_t *tx); 757 struct arc_buf *dmu_request_arcbuf(dmu_buf_t *handle, int size); 758 void dmu_return_arcbuf(struct arc_buf *buf); 759 void dmu_assign_arcbuf(dmu_buf_t *handle, uint64_t offset, struct arc_buf *buf, 760 dmu_tx_t *tx); 761 int dmu_xuio_init(struct xuio *uio, int niov); 762 void dmu_xuio_fini(struct xuio *uio); 763 int dmu_xuio_add(struct xuio *uio, struct arc_buf *abuf, offset_t off, 764 size_t n); 765 int dmu_xuio_cnt(struct xuio *uio); 766 struct arc_buf *dmu_xuio_arcbuf(struct xuio *uio, int i); 767 void dmu_xuio_clear(struct xuio *uio, int i); 768 void xuio_stat_wbuf_copied(void); 769 void xuio_stat_wbuf_nocopy(void); 770 771 extern boolean_t zfs_prefetch_disable; 772 extern int zfs_max_recordsize; 773 774 /* 775 * Asynchronously try to read in the data. 776 */ 777 void dmu_prefetch(objset_t *os, uint64_t object, int64_t level, uint64_t offset, 778 uint64_t len, enum zio_priority pri); 779 780 typedef struct dmu_object_info { 781 /* All sizes are in bytes unless otherwise indicated. */ 782 uint32_t doi_data_block_size; 783 uint32_t doi_metadata_block_size; 784 dmu_object_type_t doi_type; 785 dmu_object_type_t doi_bonus_type; 786 uint64_t doi_bonus_size; 787 uint8_t doi_indirection; /* 2 = dnode->indirect->data */ 788 uint8_t doi_checksum; 789 uint8_t doi_compress; 790 uint8_t doi_nblkptr; 791 uint8_t doi_pad[4]; 792 uint64_t doi_physical_blocks_512; /* data + metadata, 512b blks */ 793 uint64_t doi_max_offset; 794 uint64_t doi_fill_count; /* number of non-empty blocks */ 795 } dmu_object_info_t; 796 797 typedef void arc_byteswap_func_t(void *buf, size_t size); 798 799 typedef struct dmu_object_type_info { 800 dmu_object_byteswap_t ot_byteswap; 801 boolean_t ot_metadata; 802 char *ot_name; 803 } dmu_object_type_info_t; 804 805 typedef struct dmu_object_byteswap_info { 806 arc_byteswap_func_t *ob_func; 807 char *ob_name; 808 } dmu_object_byteswap_info_t; 809 810 extern const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES]; 811 extern const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS]; 812 813 /* 814 * Get information on a DMU object. 815 * 816 * Return 0 on success or ENOENT if object is not allocated. 817 * 818 * If doi is NULL, just indicates whether the object exists. 819 */ 820 int dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi); 821 /* Like dmu_object_info, but faster if you have a held dnode in hand. */ 822 void dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi); 823 /* Like dmu_object_info, but faster if you have a held dbuf in hand. */ 824 void dmu_object_info_from_db(dmu_buf_t *db, dmu_object_info_t *doi); 825 /* 826 * Like dmu_object_info_from_db, but faster still when you only care about 827 * the size. This is specifically optimized for zfs_getattr(). 828 */ 829 void dmu_object_size_from_db(dmu_buf_t *db, uint32_t *blksize, 830 u_longlong_t *nblk512); 831 832 typedef struct dmu_objset_stats { 833 uint64_t dds_num_clones; /* number of clones of this */ 834 uint64_t dds_creation_txg; 835 uint64_t dds_guid; 836 dmu_objset_type_t dds_type; 837 uint8_t dds_is_snapshot; 838 uint8_t dds_inconsistent; 839 char dds_origin[ZFS_MAX_DATASET_NAME_LEN]; 840 } dmu_objset_stats_t; 841 842 /* 843 * Get stats on a dataset. 844 */ 845 void dmu_objset_fast_stat(objset_t *os, dmu_objset_stats_t *stat); 846 847 /* 848 * Add entries to the nvlist for all the objset's properties. See 849 * zfs_prop_table[] and zfs(1m) for details on the properties. 850 */ 851 void dmu_objset_stats(objset_t *os, struct nvlist *nv); 852 853 /* 854 * Get the space usage statistics for statvfs(). 855 * 856 * refdbytes is the amount of space "referenced" by this objset. 857 * availbytes is the amount of space available to this objset, taking 858 * into account quotas & reservations, assuming that no other objsets 859 * use the space first. These values correspond to the 'referenced' and 860 * 'available' properties, described in the zfs(1m) manpage. 861 * 862 * usedobjs and availobjs are the number of objects currently allocated, 863 * and available. 864 */ 865 void dmu_objset_space(objset_t *os, uint64_t *refdbytesp, uint64_t *availbytesp, 866 uint64_t *usedobjsp, uint64_t *availobjsp); 867 868 /* 869 * The fsid_guid is a 56-bit ID that can change to avoid collisions. 870 * (Contrast with the ds_guid which is a 64-bit ID that will never 871 * change, so there is a small probability that it will collide.) 872 */ 873 uint64_t dmu_objset_fsid_guid(objset_t *os); 874 875 /* 876 * Get the [cm]time for an objset's snapshot dir 877 */ 878 timestruc_t dmu_objset_snap_cmtime(objset_t *os); 879 880 int dmu_objset_is_snapshot(objset_t *os); 881 882 extern struct spa *dmu_objset_spa(objset_t *os); 883 extern struct zilog *dmu_objset_zil(objset_t *os); 884 extern struct dsl_pool *dmu_objset_pool(objset_t *os); 885 extern struct dsl_dataset *dmu_objset_ds(objset_t *os); 886 extern void dmu_objset_name(objset_t *os, char *buf); 887 extern dmu_objset_type_t dmu_objset_type(objset_t *os); 888 extern uint64_t dmu_objset_id(objset_t *os); 889 extern zfs_sync_type_t dmu_objset_syncprop(objset_t *os); 890 extern zfs_logbias_op_t dmu_objset_logbias(objset_t *os); 891 extern int dmu_snapshot_list_next(objset_t *os, int namelen, char *name, 892 uint64_t *id, uint64_t *offp, boolean_t *case_conflict); 893 extern int dmu_snapshot_realname(objset_t *os, char *name, char *real, 894 int maxlen, boolean_t *conflict); 895 extern int dmu_dir_list_next(objset_t *os, int namelen, char *name, 896 uint64_t *idp, uint64_t *offp); 897 898 typedef int objset_used_cb_t(dmu_object_type_t bonustype, 899 void *bonus, uint64_t *userp, uint64_t *groupp); 900 extern void dmu_objset_register_type(dmu_objset_type_t ost, 901 objset_used_cb_t *cb); 902 extern void dmu_objset_set_user(objset_t *os, void *user_ptr); 903 extern void *dmu_objset_get_user(objset_t *os); 904 905 /* 906 * Return the txg number for the given assigned transaction. 907 */ 908 uint64_t dmu_tx_get_txg(dmu_tx_t *tx); 909 910 /* 911 * Synchronous write. 912 * If a parent zio is provided this function initiates a write on the 913 * provided buffer as a child of the parent zio. 914 * In the absence of a parent zio, the write is completed synchronously. 915 * At write completion, blk is filled with the bp of the written block. 916 * Note that while the data covered by this function will be on stable 917 * storage when the write completes this new data does not become a 918 * permanent part of the file until the associated transaction commits. 919 */ 920 921 /* 922 * {zfs,zvol,ztest}_get_done() args 923 */ 924 typedef struct zgd { 925 struct lwb *zgd_lwb; 926 struct blkptr *zgd_bp; 927 dmu_buf_t *zgd_db; 928 struct rl *zgd_rl; 929 void *zgd_private; 930 } zgd_t; 931 932 typedef void dmu_sync_cb_t(zgd_t *arg, int error); 933 int dmu_sync(struct zio *zio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd); 934 935 /* 936 * Find the next hole or data block in file starting at *off 937 * Return found offset in *off. Return ESRCH for end of file. 938 */ 939 int dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole, 940 uint64_t *off); 941 942 /* 943 * Check if a DMU object has any dirty blocks. If so, sync out 944 * all pending transaction groups. Otherwise, this function 945 * does not alter DMU state. This could be improved to only sync 946 * out the necessary transaction groups for this particular 947 * object. 948 */ 949 int dmu_object_wait_synced(objset_t *os, uint64_t object); 950 951 /* 952 * Initial setup and final teardown. 953 */ 954 extern void dmu_init(void); 955 extern void dmu_fini(void); 956 957 typedef void (*dmu_traverse_cb_t)(objset_t *os, void *arg, struct blkptr *bp, 958 uint64_t object, uint64_t offset, int len); 959 void dmu_traverse_objset(objset_t *os, uint64_t txg_start, 960 dmu_traverse_cb_t cb, void *arg); 961 962 int dmu_diff(const char *tosnap_name, const char *fromsnap_name, 963 struct vnode *vp, offset_t *offp); 964 965 /* CRC64 table */ 966 #define ZFS_CRC64_POLY 0xC96C5795D7870F42ULL /* ECMA-182, reflected form */ 967 extern uint64_t zfs_crc64_table[256]; 968 969 extern int zfs_mdcomp_disable; 970 971 #ifdef __cplusplus 972 } 973 #endif 974 975 #endif /* _SYS_DMU_H */ 976