zfs/lib/libzcommon/include/sys/dmu.h

   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  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #ifndef _SYS_DMU_H
  27 #define _SYS_DMU_H
  28
  29 #pragma ident   "@(#)dmu.h      1.38    08/04/27 SMI"
  30
  31 /*
  32  * This file describes the interface that the DMU provides for its
  33  * consumers.
  34  *
  35  * The DMU also interacts with the SPA.  That interface is described in
  36  * dmu_spa.h.
  37  */
  38
  39 #include <sys/inttypes.h>
  40 #include <sys/types.h>
  41 #include <sys/param.h>
  42 #include <sys/cred.h>
  43
  44 #ifdef  __cplusplus
  45 extern "C" {
  46 #endif
  47
  48 struct uio;
  49 struct page;
  50 struct vnode;
  51 struct spa;
  52 struct zilog;
  53 struct zio;
  54 struct blkptr;
  55 struct zap_cursor;
  56 struct dsl_dataset;
  57 struct dsl_pool;
  58 struct dnode;
  59 struct drr_begin;
  60 struct drr_end;
  61 struct zbookmark;
  62 struct spa;
  63 struct nvlist;
  64 struct objset_impl;
  65
  66 typedef struct objset objset_t;
  67 typedef struct dmu_tx dmu_tx_t;
  68 typedef struct dsl_dir dsl_dir_t;
  69
  70 typedef enum dmu_object_type {
  71         DMU_OT_NONE,
  72         /* general: */
  73         DMU_OT_OBJECT_DIRECTORY,        /* ZAP */
  74         DMU_OT_OBJECT_ARRAY,            /* UINT64 */
  75         DMU_OT_PACKED_NVLIST,           /* UINT8 (XDR by nvlist_pack/unpack) */
  76         DMU_OT_PACKED_NVLIST_SIZE,      /* UINT64 */
  77         DMU_OT_BPLIST,                  /* UINT64 */
  78         DMU_OT_BPLIST_HDR,              /* UINT64 */
  79         /* spa: */
  80         DMU_OT_SPACE_MAP_HEADER,        /* UINT64 */
  81         DMU_OT_SPACE_MAP,               /* UINT64 */
  82         /* zil: */
  83         DMU_OT_INTENT_LOG,              /* UINT64 */
  84         /* dmu: */
  85         DMU_OT_DNODE,                   /* DNODE */
  86         DMU_OT_OBJSET,                  /* OBJSET */
  87         /* dsl: */
  88         DMU_OT_DSL_DIR,                 /* UINT64 */
  89         DMU_OT_DSL_DIR_CHILD_MAP,       /* ZAP */
  90         DMU_OT_DSL_DS_SNAP_MAP,         /* ZAP */
  91         DMU_OT_DSL_PROPS,               /* ZAP */
  92         DMU_OT_DSL_DATASET,             /* UINT64 */
  93         /* zpl: */
  94         DMU_OT_ZNODE,                   /* ZNODE */
  95         DMU_OT_OLDACL,                  /* Old ACL */
  96         DMU_OT_PLAIN_FILE_CONTENTS,     /* UINT8 */
  97         DMU_OT_DIRECTORY_CONTENTS,      /* ZAP */
  98         DMU_OT_MASTER_NODE,             /* ZAP */
  99         DMU_OT_UNLINKED_SET,            /* ZAP */
 100         /* zvol: */
 101         DMU_OT_ZVOL,                    /* UINT8 */
 102         DMU_OT_ZVOL_PROP,               /* ZAP */
 103         /* other; for testing only! */
 104         DMU_OT_PLAIN_OTHER,             /* UINT8 */
 105         DMU_OT_UINT64_OTHER,            /* UINT64 */
 106         DMU_OT_ZAP_OTHER,               /* ZAP */
 107         /* new object types: */
 108         DMU_OT_ERROR_LOG,               /* ZAP */
 109         DMU_OT_SPA_HISTORY,             /* UINT8 */
 110         DMU_OT_SPA_HISTORY_OFFSETS,     /* spa_his_phys_t */
 111         DMU_OT_POOL_PROPS,              /* ZAP */
 112         DMU_OT_DSL_PERMS,               /* ZAP */
 113         DMU_OT_ACL,                     /* ACL */
 114         DMU_OT_SYSACL,                  /* SYSACL */
 115         DMU_OT_FUID,                    /* FUID table (Packed NVLIST UINT8) */
 116         DMU_OT_FUID_SIZE,               /* FUID table size UINT64 */
 117         DMU_OT_NUMTYPES
 118 } dmu_object_type_t;
 119
 120 typedef enum dmu_objset_type {
 121         DMU_OST_NONE,
 122         DMU_OST_META,
 123         DMU_OST_ZFS,
 124         DMU_OST_ZVOL,
 125         DMU_OST_OTHER,                  /* For testing only! */
 126         DMU_OST_ANY,                    /* Be careful! */
 127         DMU_OST_NUMTYPES
 128 } dmu_objset_type_t;
 129
 130 void byteswap_uint64_array(void *buf, size_t size);
 131 void byteswap_uint32_array(void *buf, size_t size);
 132 void byteswap_uint16_array(void *buf, size_t size);
 133 void byteswap_uint8_array(void *buf, size_t size);
 134 void zap_byteswap(void *buf, size_t size);
 135 void zfs_oldacl_byteswap(void *buf, size_t size);
 136 void zfs_acl_byteswap(void *buf, size_t size);
 137 void zfs_znode_byteswap(void *buf, size_t size);
 138
 139 #define DS_MODE_NONE            0       /* invalid, to aid debugging */
 140 #define DS_MODE_STANDARD        1       /* normal access, no special needs */
 141 #define DS_MODE_PRIMARY         2       /* the "main" access, e.g. a mount */
 142 #define DS_MODE_EXCLUSIVE       3       /* exclusive access, e.g. to destroy */
 143 #define DS_MODE_LEVELS          4
 144 #define DS_MODE_LEVEL(x)        ((x) & (DS_MODE_LEVELS - 1))
 145 #define DS_MODE_READONLY        0x8
 146 #define DS_MODE_IS_READONLY(x)  ((x) & DS_MODE_READONLY)
 147 #define DS_MODE_INCONSISTENT    0x10
 148 #define DS_MODE_IS_INCONSISTENT(x)      ((x) & DS_MODE_INCONSISTENT)
 149
 150 #define DS_FIND_SNAPSHOTS       (1<<0)
 151 #define DS_FIND_CHILDREN        (1<<1)
 152
 153 /*
 154  * The maximum number of bytes that can be accessed as part of one
 155  * operation, including metadata.
 156  */
 157 #define DMU_MAX_ACCESS (10<<20) /* 10MB */
 158
 159 /*
 160  * Public routines to create, destroy, open, and close objsets.
 161  */
 162 int dmu_objset_open(const char *name, dmu_objset_type_t type, int mode,
 163     objset_t **osp);
 164 int dmu_objset_open_ds(struct dsl_dataset *ds, dmu_objset_type_t type,
 165     objset_t **osp);
 166 void dmu_objset_close(objset_t *os);
 167 int dmu_objset_evict_dbufs(objset_t *os);
 168 int dmu_objset_create(const char *name, dmu_objset_type_t type,
 169     objset_t *clone_parent, uint64_t flags,
 170     void (*func)(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx), void *arg);
 171 int dmu_objset_destroy(const char *name);
 172 int dmu_snapshots_destroy(char *fsname, char *snapname);
 173 int dmu_objset_rollback(objset_t *os);
 174 int dmu_objset_snapshot(char *fsname, char *snapname, boolean_t recursive);
 175 int dmu_objset_rename(const char *name, const char *newname,
 176     boolean_t recursive);
 177 int dmu_objset_find(char *name, int func(char *, void *), void *arg,
 178     int flags);
 179 void dmu_objset_byteswap(void *buf, size_t size);
 180
 181 typedef struct dmu_buf {
 182         uint64_t db_object;             /* object that this buffer is part of */
 183         uint64_t db_offset;             /* byte offset in this object */
 184         uint64_t db_size;               /* size of buffer in bytes */
 185         void *db_data;                  /* data in buffer */
 186 } dmu_buf_t;
 187
 188 typedef void dmu_buf_evict_func_t(struct dmu_buf *db, void *user_ptr);
 189
 190 /*
 191  * The names of zap entries in the DIRECTORY_OBJECT of the MOS.
 192  */
 193 #define DMU_POOL_DIRECTORY_OBJECT       1
 194 #define DMU_POOL_CONFIG                 "config"
 195 #define DMU_POOL_ROOT_DATASET           "root_dataset"
 196 #define DMU_POOL_SYNC_BPLIST            "sync_bplist"
 197 #define DMU_POOL_ERRLOG_SCRUB           "errlog_scrub"
 198 #define DMU_POOL_ERRLOG_LAST            "errlog_last"
 199 #define DMU_POOL_SPARES                 "spares"
 200 #define DMU_POOL_DEFLATE                "deflate"
 201 #define DMU_POOL_HISTORY                "history"
 202 #define DMU_POOL_PROPS                  "pool_props"
 203 #define DMU_POOL_L2CACHE                "l2cache"
 204
 205 /*
 206  * Allocate an object from this objset.  The range of object numbers
 207  * available is (0, DN_MAX_OBJECT).  Object 0 is the meta-dnode.
 208  *
 209  * The transaction must be assigned to a txg.  The newly allocated
 210  * object will be "held" in the transaction (ie. you can modify the
 211  * newly allocated object in this transaction).
 212  *
 213  * dmu_object_alloc() chooses an object and returns it in *objectp.
 214  *
 215  * dmu_object_claim() allocates a specific object number.  If that
 216  * number is already allocated, it fails and returns EEXIST.
 217  *
 218  * Return 0 on success, or ENOSPC or EEXIST as specified above.
 219  */
 220 uint64_t dmu_object_alloc(objset_t *os, dmu_object_type_t ot,
 221     int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx);
 222 int dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot,
 223     int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx);
 224 int dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot,
 225     int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
 226
 227 /*
 228  * Free an object from this objset.
 229  *
 230  * The object's data will be freed as well (ie. you don't need to call
 231  * dmu_free(object, 0, -1, tx)).
 232  *
 233  * The object need not be held in the transaction.
 234  *
 235  * If there are any holds on this object's buffers (via dmu_buf_hold()),
 236  * or tx holds on the object (via dmu_tx_hold_object()), you can not
 237  * free it; it fails and returns EBUSY.
 238  *
 239  * If the object is not allocated, it fails and returns ENOENT.
 240  *
 241  * Return 0 on success, or EBUSY or ENOENT as specified above.
 242  */
 243 int dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx);
 244
 245 /*
 246  * Find the next allocated or free object.
 247  *
 248  * The objectp parameter is in-out.  It will be updated to be the next
 249  * object which is allocated.  Ignore objects which have not been
 250  * modified since txg.
 251  *
 252  * XXX Can only be called on a objset with no dirty data.
 253  *
 254  * Returns 0 on success, or ENOENT if there are no more objects.
 255  */
 256 int dmu_object_next(objset_t *os, uint64_t *objectp,
 257     boolean_t hole, uint64_t txg);
 258
 259 /*
 260  * Set the data blocksize for an object.
 261  *
 262  * The object cannot have any blocks allcated beyond the first.  If
 263  * the first block is allocated already, the new size must be greater
 264  * than the current block size.  If these conditions are not met,
 265  * ENOTSUP will be returned.
 266  *
 267  * Returns 0 on success, or EBUSY if there are any holds on the object
 268  * contents, or ENOTSUP as described above.
 269  */
 270 int dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size,
 271     int ibs, dmu_tx_t *tx);
 272
 273 /*
 274  * Set the checksum property on a dnode.  The new checksum algorithm will
 275  * apply to all newly written blocks; existing blocks will not be affected.
 276  */
 277 void dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum,
 278     dmu_tx_t *tx);
 279
 280 /*
 281  * Set the compress property on a dnode.  The new compression algorithm will
 282  * apply to all newly written blocks; existing blocks will not be affected.
 283  */
 284 void dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress,
 285     dmu_tx_t *tx);
 286
 287 /*
 288  * Decide how many copies of a given block we should make.  Can be from
 289  * 1 to SPA_DVAS_PER_BP.
 290  */
 291 int dmu_get_replication_level(struct objset_impl *, struct zbookmark *zb,
 292     dmu_object_type_t ot);
 293 /*
 294  * The bonus data is accessed more or less like a regular buffer.
 295  * You must dmu_bonus_hold() to get the buffer, which will give you a
 296  * dmu_buf_t with db_offset==-1ULL, and db_size = the size of the bonus
 297  * data.  As with any normal buffer, you must call dmu_buf_read() to
 298  * read db_data, dmu_buf_will_dirty() before modifying it, and the
 299  * object must be held in an assigned transaction before calling
 300  * dmu_buf_will_dirty.  You may use dmu_buf_set_user() on the bonus
 301  * buffer as well.  You must release your hold with dmu_buf_rele().
 302  */
 303 int dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **);
 304 int dmu_bonus_max(void);
 305 int dmu_set_bonus(dmu_buf_t *, int, dmu_tx_t *);
 306
 307 /*
 308  * Obtain the DMU buffer from the specified object which contains the
 309  * specified offset.  dmu_buf_hold() puts a "hold" on the buffer, so
 310  * that it will remain in memory.  You must release the hold with
 311  * dmu_buf_rele().  You musn't access the dmu_buf_t after releasing your
 312  * hold.  You must have a hold on any dmu_buf_t* you pass to the DMU.
 313  *
 314  * You must call dmu_buf_read, dmu_buf_will_dirty, or dmu_buf_will_fill
 315  * on the returned buffer before reading or writing the buffer's
 316  * db_data.  The comments for those routines describe what particular
 317  * operations are valid after calling them.
 318  *
 319  * The object number must be a valid, allocated object number.
 320  */
 321 int dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset,
 322     void *tag, dmu_buf_t **);
 323 void dmu_buf_add_ref(dmu_buf_t *db, void* tag);
 324 void dmu_buf_rele(dmu_buf_t *db, void *tag);
 325 uint64_t dmu_buf_refcount(dmu_buf_t *db);
 326
 327 /*
 328  * dmu_buf_hold_array holds the DMU buffers which contain all bytes in a
 329  * range of an object.  A pointer to an array of dmu_buf_t*'s is
 330  * returned (in *dbpp).
 331  *
 332  * dmu_buf_rele_array releases the hold on an array of dmu_buf_t*'s, and
 333  * frees the array.  The hold on the array of buffers MUST be released
 334  * with dmu_buf_rele_array.  You can NOT release the hold on each buffer
 335  * individually with dmu_buf_rele.
 336  */
 337 int dmu_buf_hold_array_by_bonus(dmu_buf_t *db, uint64_t offset,
 338     uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp);
 339 void dmu_buf_rele_array(dmu_buf_t **, int numbufs, void *tag);
 340
 341 /*
 342  * Returns NULL on success, or the existing user ptr if it's already
 343  * been set.
 344  *
 345  * user_ptr is for use by the user and can be obtained via dmu_buf_get_user().
 346  *
 347  * user_data_ptr_ptr should be NULL, or a pointer to a pointer which
 348  * will be set to db->db_data when you are allowed to access it.  Note
 349  * that db->db_data (the pointer) can change when you do dmu_buf_read(),
 350  * dmu_buf_tryupgrade(), dmu_buf_will_dirty(), or dmu_buf_will_fill().
 351  * *user_data_ptr_ptr will be set to the new value when it changes.
 352  *
 353  * If non-NULL, pageout func will be called when this buffer is being
 354  * excised from the cache, so that you can clean up the data structure
 355  * pointed to by user_ptr.
 356  *
 357  * dmu_evict_user() will call the pageout func for all buffers in a
 358  * objset with a given pageout func.
 359  */
 360 void *dmu_buf_set_user(dmu_buf_t *db, void *user_ptr, void *user_data_ptr_ptr,
 361     dmu_buf_evict_func_t *pageout_func);
 362 /*
 363  * set_user_ie is the same as set_user, but request immediate eviction
 364  * when hold count goes to zero.
 365  */
 366 void *dmu_buf_set_user_ie(dmu_buf_t *db, void *user_ptr,
 367     void *user_data_ptr_ptr, dmu_buf_evict_func_t *pageout_func);
 368 void *dmu_buf_update_user(dmu_buf_t *db_fake, void *old_user_ptr,
 369     void *user_ptr, void *user_data_ptr_ptr,
 370     dmu_buf_evict_func_t *pageout_func);
 371 void dmu_evict_user(objset_t *os, dmu_buf_evict_func_t *func);
 372
 373 /*
 374  * Returns the user_ptr set with dmu_buf_set_user(), or NULL if not set.
 375  */
 376 void *dmu_buf_get_user(dmu_buf_t *db);
 377
 378 /*
 379  * Indicate that you are going to modify the buffer's data (db_data).
 380  *
 381  * The transaction (tx) must be assigned to a txg (ie. you've called
 382  * dmu_tx_assign()).  The buffer's object must be held in the tx
 383  * (ie. you've called dmu_tx_hold_object(tx, db->db_object)).
 384  */
 385 void dmu_buf_will_dirty(dmu_buf_t *db, dmu_tx_t *tx);
 386
 387 /*
 388  * You must create a transaction, then hold the objects which you will
 389  * (or might) modify as part of this transaction.  Then you must assign
 390  * the transaction to a transaction group.  Once the transaction has
 391  * been assigned, you can modify buffers which belong to held objects as
 392  * part of this transaction.  You can't modify buffers before the
 393  * transaction has been assigned; you can't modify buffers which don't
 394  * belong to objects which this transaction holds; you can't hold
 395  * objects once the transaction has been assigned.  You may hold an
 396  * object which you are going to free (with dmu_object_free()), but you
 397  * don't have to.
 398  *
 399  * You can abort the transaction before it has been assigned.
 400  *
 401  * Note that you may hold buffers (with dmu_buf_hold) at any time,
 402  * regardless of transaction state.
 403  */
 404
 405 #define DMU_NEW_OBJECT  (-1ULL)
 406 #define DMU_OBJECT_END  (-1ULL)
 407
 408 dmu_tx_t *dmu_tx_create(objset_t *os);
 409 void dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len);
 410 void dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off,
 411     uint64_t len);
 412 void dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, char *name);
 413 void dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object);
 414 void dmu_tx_abort(dmu_tx_t *tx);
 415 int dmu_tx_assign(dmu_tx_t *tx, uint64_t txg_how);
 416 void dmu_tx_wait(dmu_tx_t *tx);
 417 void dmu_tx_commit(dmu_tx_t *tx);
 418
 419 /*
 420  * Free up the data blocks for a defined range of a file.  If size is
 421  * zero, the range from offset to end-of-file is freed.
 422  */
 423 int dmu_free_range(objset_t *os, uint64_t object, uint64_t offset,
 424         uint64_t size, dmu_tx_t *tx);
 425
 426 /*
 427  * Convenience functions.
 428  *
 429  * Canfail routines will return 0 on success, or an errno if there is a
 430  * nonrecoverable I/O error.
 431  */
 432 int dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
 433         void *buf);
 434 void dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
 435         const void *buf, dmu_tx_t *tx);
 436 int dmu_read_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size);
 437 int dmu_write_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size,
 438     dmu_tx_t *tx);
 439 int dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset,
 440     uint64_t size, struct page *pp, dmu_tx_t *tx);
 441
 442 extern int zfs_prefetch_disable;
 443
 444 /*
 445  * Asynchronously try to read in the data.
 446  */
 447 void dmu_prefetch(objset_t *os, uint64_t object, uint64_t offset,
 448     uint64_t len);
 449
 450 typedef struct dmu_object_info {
 451         /* All sizes are in bytes. */
 452         uint32_t doi_data_block_size;
 453         uint32_t doi_metadata_block_size;
 454         uint64_t doi_bonus_size;
 455         dmu_object_type_t doi_type;
 456         dmu_object_type_t doi_bonus_type;
 457         uint8_t doi_indirection;                /* 2 = dnode->indirect->data */
 458         uint8_t doi_checksum;
 459         uint8_t doi_compress;
 460         uint8_t doi_pad[5];
 461         /* Values below are number of 512-byte blocks. */
 462         uint64_t doi_physical_blks;             /* data + metadata */
 463         uint64_t doi_max_block_offset;
 464 } dmu_object_info_t;
 465
 466 typedef void arc_byteswap_func_t(void *buf, size_t size);
 467
 468 typedef struct dmu_object_type_info {
 469         arc_byteswap_func_t     *ot_byteswap;
 470         boolean_t               ot_metadata;
 471         char                    *ot_name;
 472 } dmu_object_type_info_t;
 473
 474 extern const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES];
 475
 476 /*
 477  * Get information on a DMU object.
 478  *
 479  * Return 0 on success or ENOENT if object is not allocated.
 480  *
 481  * If doi is NULL, just indicates whether the object exists.
 482  */
 483 int dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi);
 484 void dmu_object_info_from_dnode(struct dnode *dn, dmu_object_info_t *doi);
 485 void dmu_object_info_from_db(dmu_buf_t *db, dmu_object_info_t *doi);
 486 void dmu_object_size_from_db(dmu_buf_t *db, uint32_t *blksize,
 487     u_longlong_t *nblk512);
 488
 489 typedef struct dmu_objset_stats {
 490         uint64_t dds_num_clones; /* number of clones of this */
 491         uint64_t dds_creation_txg;
 492         uint64_t dds_guid;
 493         dmu_objset_type_t dds_type;
 494         uint8_t dds_is_snapshot;
 495         uint8_t dds_inconsistent;
 496         char dds_origin[MAXNAMELEN];
 497 } dmu_objset_stats_t;
 498
 499 /*
 500  * Get stats on a dataset.
 501  */
 502 void dmu_objset_fast_stat(objset_t *os, dmu_objset_stats_t *stat);
 503
 504 /*
 505  * Add entries to the nvlist for all the objset's properties.  See
 506  * zfs_prop_table[] and zfs(1m) for details on the properties.
 507  */
 508 void dmu_objset_stats(objset_t *os, struct nvlist *nv);
 509
 510 /*
 511  * Get the space usage statistics for statvfs().
 512  *
 513  * refdbytes is the amount of space "referenced" by this objset.
 514  * availbytes is the amount of space available to this objset, taking
 515  * into account quotas & reservations, assuming that no other objsets
 516  * use the space first.  These values correspond to the 'referenced' and
 517  * 'available' properties, described in the zfs(1m) manpage.
 518  *
 519  * usedobjs and availobjs are the number of objects currently allocated,
 520  * and available.
 521  */
 522 void dmu_objset_space(objset_t *os, uint64_t *refdbytesp, uint64_t *availbytesp,
 523     uint64_t *usedobjsp, uint64_t *availobjsp);
 524
 525 /*
 526  * The fsid_guid is a 56-bit ID that can change to avoid collisions.
 527  * (Contrast with the ds_guid which is a 64-bit ID that will never
 528  * change, so there is a small probability that it will collide.)
 529  */
 530 uint64_t dmu_objset_fsid_guid(objset_t *os);
 531
 532 int dmu_objset_is_snapshot(objset_t *os);
 533
 534 extern struct spa *dmu_objset_spa(objset_t *os);
 535 extern struct zilog *dmu_objset_zil(objset_t *os);
 536 extern struct dsl_pool *dmu_objset_pool(objset_t *os);
 537 extern struct dsl_dataset *dmu_objset_ds(objset_t *os);
 538 extern void dmu_objset_name(objset_t *os, char *buf);
 539 extern dmu_objset_type_t dmu_objset_type(objset_t *os);
 540 extern uint64_t dmu_objset_id(objset_t *os);
 541 extern int dmu_snapshot_list_next(objset_t *os, int namelen, char *name,
 542     uint64_t *id, uint64_t *offp, boolean_t *case_conflict);
 543 extern int dmu_snapshot_realname(objset_t *os, char *name, char *real,
 544     int maxlen, boolean_t *conflict);
 545 extern int dmu_dir_list_next(objset_t *os, int namelen, char *name,
 546     uint64_t *idp, uint64_t *offp);
 547 extern void dmu_objset_set_user(objset_t *os, void *user_ptr);
 548 extern void *dmu_objset_get_user(objset_t *os);
 549
 550 /*
 551  * Return the txg number for the given assigned transaction.
 552  */
 553 uint64_t dmu_tx_get_txg(dmu_tx_t *tx);
 554
 555 /*
 556  * Synchronous write.
 557  * If a parent zio is provided this function initiates a write on the
 558  * provided buffer as a child of the parent zio.
 559  * In the absence of a parent zio, the write is completed synchronously.
 560  * At write completion, blk is filled with the bp of the written block.
 561  * Note that while the data covered by this function will be on stable
 562  * storage when the write completes this new data does not become a
 563  * permanent part of the file until the associated transaction commits.
 564  */
 565 typedef void dmu_sync_cb_t(dmu_buf_t *db, void *arg);
 566 int dmu_sync(struct zio *zio, dmu_buf_t *db,
 567     struct blkptr *bp, uint64_t txg, dmu_sync_cb_t *done, void *arg);
 568
 569 /*
 570  * Find the next hole or data block in file starting at *off
 571  * Return found offset in *off. Return ESRCH for end of file.
 572  */
 573 int dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole,
 574     uint64_t *off);
 575
 576 /*
 577  * Initial setup and final teardown.
 578  */
 579 extern void dmu_init(void);
 580 extern void dmu_fini(void);
 581
 582 typedef void (*dmu_traverse_cb_t)(objset_t *os, void *arg, struct blkptr *bp,
 583     uint64_t object, uint64_t offset, int len);
 584 void dmu_traverse_objset(objset_t *os, uint64_t txg_start,
 585     dmu_traverse_cb_t cb, void *arg);
 586
 587 int dmu_sendbackup(objset_t *tosnap, objset_t *fromsnap, boolean_t fromorigin,
 588     struct vnode *vp, offset_t *off);
 589
 590 typedef struct dmu_recv_cookie {
 591         /*
 592          * This structure is opaque!
 593          *
 594          * If logical and real are different, we are recving the stream
 595          * into the "real" temporary clone, and then switching it with
 596          * the "logical" target.
 597          */
 598         struct dsl_dataset *drc_logical_ds;
 599         struct dsl_dataset *drc_real_ds;
 600         struct drr_begin *drc_drrb;
 601         char *drc_tosnap;
 602         boolean_t drc_newfs;
 603         boolean_t drc_force;
 604 } dmu_recv_cookie_t;
 605
 606 int dmu_recv_begin(char *tofs, char *tosnap, struct drr_begin *,
 607     boolean_t force, objset_t *origin, boolean_t online, dmu_recv_cookie_t *);
 608 int dmu_recv_stream(dmu_recv_cookie_t *drc, struct vnode *vp, offset_t *voffp);
 609 int dmu_recv_end(dmu_recv_cookie_t *drc);
 610 void dmu_recv_abort_cleanup(dmu_recv_cookie_t *drc);
 611
 612 /* CRC64 table */
 613 #define ZFS_CRC64_POLY  0xC96C5795D7870F42ULL   /* ECMA-182, reflected form */
 614 extern uint64_t zfs_crc64_table[256];
 615
 616 #ifdef  __cplusplus
 617 }
 618 #endif
 619
 620 #endif  /* _SYS_DMU_H */