dmu.h revision 0b69c2f001a429251e2d38f25aca860396551214
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#ifndef _SYS_DMU_H
#define _SYS_DMU_H
#pragma ident "%Z%%M% %I% %E% SMI"
/*
* This file describes the interface that the DMU provides for its
* consumers.
*
* The DMU also interacts with the SPA. That interface is described in
* dmu_spa.h.
*/
#include <sys/inttypes.h>
#include <sys/types.h>
#include <sys/param.h>
#ifdef __cplusplus
extern "C" {
#endif
struct uio;
struct vnode;
struct spa;
struct zilog;
struct zio;
struct blkptr;
struct zap_cursor;
struct dsl_dataset;
struct dsl_pool;
struct dnode;
struct drr_begin;
struct drr_end;
struct zbookmark;
struct spa;
typedef struct objset objset_t;
typedef struct dmu_tx dmu_tx_t;
typedef struct dsl_dir dsl_dir_t;
typedef enum dmu_object_type {
DMU_OT_NONE,
/* general: */
DMU_OT_OBJECT_DIRECTORY, /* ZAP */
DMU_OT_OBJECT_ARRAY, /* UINT64 */
DMU_OT_PACKED_NVLIST, /* UINT8 (XDR by nvlist_pack/unpack) */
DMU_OT_PACKED_NVLIST_SIZE, /* UINT64 */
DMU_OT_BPLIST, /* UINT64 */
DMU_OT_BPLIST_HDR, /* UINT64 */
/* spa: */
DMU_OT_SPACE_MAP_HEADER, /* UINT64 */
DMU_OT_SPACE_MAP, /* UINT64 */
/* zil: */
DMU_OT_INTENT_LOG, /* UINT64 */
/* dmu: */
DMU_OT_DNODE, /* DNODE */
DMU_OT_OBJSET, /* OBJSET */
/* dsl: */
DMU_OT_DSL_DIR, /* UINT64 */
DMU_OT_DSL_DIR_CHILD_MAP, /* ZAP */
DMU_OT_DSL_DS_SNAP_MAP, /* ZAP */
DMU_OT_DSL_PROPS, /* ZAP */
DMU_OT_DSL_DATASET, /* UINT64 */
/* zpl: */
DMU_OT_ZNODE, /* ZNODE */
DMU_OT_ACL, /* ACL */
DMU_OT_PLAIN_FILE_CONTENTS, /* UINT8 */
DMU_OT_DIRECTORY_CONTENTS, /* ZAP */
DMU_OT_MASTER_NODE, /* ZAP */
DMU_OT_DELETE_QUEUE, /* ZAP */
/* zvol: */
DMU_OT_ZVOL, /* UINT8 */
DMU_OT_ZVOL_PROP, /* ZAP */
/* other; for testing only! */
DMU_OT_PLAIN_OTHER, /* UINT8 */
DMU_OT_UINT64_OTHER, /* UINT64 */
DMU_OT_ZAP_OTHER, /* ZAP */
/* new object types: */
DMU_OT_ERROR_LOG, /* ZAP */
DMU_OT_NUMTYPES
} dmu_object_type_t;
typedef enum dmu_objset_type {
DMU_OST_NONE,
DMU_OST_META,
DMU_OST_ZFS,
DMU_OST_ZVOL,
DMU_OST_OTHER, /* For testing only! */
DMU_OST_ANY, /* Be careful! */
DMU_OST_NUMTYPES
} dmu_objset_type_t;
void byteswap_uint64_array(void *buf, size_t size);
void byteswap_uint32_array(void *buf, size_t size);
void byteswap_uint16_array(void *buf, size_t size);
void byteswap_uint8_array(void *buf, size_t size);
void zap_byteswap(void *buf, size_t size);
void zfs_acl_byteswap(void *buf, size_t size);
void zfs_znode_byteswap(void *buf, size_t size);
#define DS_MODE_NONE 0 /* invalid, to aid debugging */
#define DS_MODE_STANDARD 1 /* normal access, no special needs */
#define DS_MODE_PRIMARY 2 /* the "main" access, e.g. a mount */
#define DS_MODE_EXCLUSIVE 3 /* exclusive access, e.g. to destroy */
#define DS_MODE_LEVELS 4
#define DS_MODE_LEVEL(x) ((x) & (DS_MODE_LEVELS - 1))
#define DS_MODE_READONLY 0x8
#define DS_MODE_IS_READONLY(x) ((x) & DS_MODE_READONLY)
#define DS_MODE_INCONSISTENT 0x10
#define DS_MODE_IS_INCONSISTENT(x) ((x) & DS_MODE_INCONSISTENT)
#define DS_FIND_SNAPSHOTS (1<<0)
#define DS_FIND_CHILDREN (1<<1)
/*
* The maximum number of bytes that can be accessed as part of one
* operation, including metadata.
*/
#define DMU_MAX_ACCESS (10<<20) /* 10MB */
/*
* Public routines to create, destroy, open, and close objsets.
*/
int dmu_objset_open(const char *name, dmu_objset_type_t type, int mode,
objset_t **osp);
void dmu_objset_close(objset_t *os);
int dmu_objset_evict_dbufs(objset_t *os, int try);
int dmu_objset_create(const char *name, dmu_objset_type_t type,
objset_t *clone_parent,
void (*func)(objset_t *os, void *arg, dmu_tx_t *tx), void *arg);
int dmu_objset_destroy(const char *name);
int dmu_snapshots_destroy(char *fsname, char *snapname);
int dmu_objset_rollback(const char *name);
int dmu_objset_snapshot(char *fsname, char *snapname, boolean_t recursive);
int dmu_objset_rename(const char *name, const char *newname);
void dmu_objset_set_quota(objset_t *os, uint64_t quota);
uint64_t dmu_objset_get_quota(objset_t *os);
int dmu_objset_request_reservation(objset_t *os, uint64_t reservation);
int dmu_objset_find(char *name, int func(char *, void *), void *arg,
int flags);
void dmu_objset_byteswap(void *buf, size_t size);
typedef struct dmu_buf {
uint64_t db_object; /* object that this buffer is part of */
uint64_t db_offset; /* byte offset in this object */
uint64_t db_size; /* size of buffer in bytes */
void *db_data; /* data in buffer */
} dmu_buf_t;
typedef void dmu_buf_evict_func_t(struct dmu_buf *db, void *user_ptr);
/*
* Callback function to perform byte swapping on a block.
*/
typedef void dmu_byteswap_func_t(void *buf, size_t size);
/*
* The names of zap entries in the DIRECTORY_OBJECT of the MOS.
*/
#define DMU_POOL_DIRECTORY_OBJECT 1
#define DMU_POOL_CONFIG "config"
#define DMU_POOL_ROOT_DATASET "root_dataset"
#define DMU_POOL_SYNC_BPLIST "sync_bplist"
#define DMU_POOL_ERRLOG_SCRUB "errlog_scrub"
#define DMU_POOL_ERRLOG_LAST "errlog_last"
#define DMU_POOL_SPARES "spares"
#define DMU_POOL_DEFLATE "deflate"
/*
* Allocate an object from this objset. The range of object numbers
* available is (0, DN_MAX_OBJECT). Object 0 is the meta-dnode.
*
* The transaction must be assigned to a txg. The newly allocated
* object will be "held" in the transaction (ie. you can modify the
* newly allocated object in this transaction).
*
* dmu_object_alloc() chooses an object and returns it in *objectp.
*
* dmu_object_claim() allocates a specific object number. If that
* number is already allocated, it fails and returns EEXIST.
*
* Return 0 on success, or ENOSPC or EEXIST as specified above.
*/
uint64_t dmu_object_alloc(objset_t *os, dmu_object_type_t ot,
int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx);
int dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot,
int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx);
int dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot,
int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
/*
* Free an object from this objset.
*
* The object's data will be freed as well (ie. you don't need to call
* dmu_free(object, 0, -1, tx)).
*
* The object need not be held in the transaction.
*
* If there are any holds on this object's buffers (via dmu_buf_hold()),
* or tx holds on the object (via dmu_tx_hold_object()), you can not
* free it; it fails and returns EBUSY.
*
* If the object is not allocated, it fails and returns ENOENT.
*
* Return 0 on success, or EBUSY or ENOENT as specified above.
*/
int dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx);
/*
* Find the next allocated or free object.
*
* The objectp parameter is in-out. It will be updated to be the next
* object which is allocated.
*
* XXX Can only be called on a objset with no dirty data.
*
* Returns 0 on success, or ENOENT if there are no more objects.
*/
int dmu_object_next(objset_t *os, uint64_t *objectp, boolean_t hole);
/*
* Set the data blocksize for an object.
*
* The object cannot have any blocks allcated beyond the first. If
* the first block is allocated already, the new size must be greater
* than the current block size. If these conditions are not met,
* ENOTSUP will be returned.
*
* Returns 0 on success, or EBUSY if there are any holds on the object
* contents, or ENOTSUP as described above.
*/
int dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size,
int ibs, dmu_tx_t *tx);
/*
* Set the checksum property on a dnode. The new checksum algorithm will
* apply to all newly written blocks; existing blocks will not be affected.
*/
void dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum,
dmu_tx_t *tx);
/*
* Set the compress property on a dnode. The new compression algorithm will
* apply to all newly written blocks; existing blocks will not be affected.
*/
void dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress,
dmu_tx_t *tx);
/*
* Decide how many copies of a given block we should make. Can be from
* 1 to SPA_DVAS_PER_BP.
*/
int dmu_get_replication_level(struct spa *spa, struct zbookmark *zb,
dmu_object_type_t ot);
/*
* The bonus data is accessed more or less like a regular buffer.
* You must dmu_bonus_hold() to get the buffer, which will give you a
* dmu_buf_t with db_offset==-1ULL, and db_size = the size of the bonus
* data. As with any normal buffer, you must call dmu_buf_read() to
* read db_data, dmu_buf_will_dirty() before modifying it, and the
* object must be held in an assigned transaction before calling
* dmu_buf_will_dirty. You may use dmu_buf_set_user() on the bonus
* buffer as well. You must release your hold with dmu_buf_rele().
*/
int dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **);
int dmu_bonus_max(void);
/*
* Obtain the DMU buffer from the specified object which contains the
* specified offset. dmu_buf_hold() puts a "hold" on the buffer, so
* that it will remain in memory. You must release the hold with
* dmu_buf_rele(). You musn't access the dmu_buf_t after releasing your
* hold. You must have a hold on any dmu_buf_t* you pass to the DMU.
*
* You must call dmu_buf_read, dmu_buf_will_dirty, or dmu_buf_will_fill
* on the returned buffer before reading or writing the buffer's
* db_data. The comments for those routines describe what particular
* operations are valid after calling them.
*
* The object number must be a valid, allocated object number.
*/
int dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset,
void *tag, dmu_buf_t **);
void dmu_buf_add_ref(dmu_buf_t *db, void* tag);
void dmu_buf_rele(dmu_buf_t *db, void *tag);
uint64_t dmu_buf_refcount(dmu_buf_t *db);
/*
* dmu_buf_hold_array holds the DMU buffers which contain all bytes in a
* range of an object. A pointer to an array of dmu_buf_t*'s is
* returned (in *dbpp).
*
* dmu_buf_rele_array releases the hold on an array of dmu_buf_t*'s, and
* frees the array. The hold on the array of buffers MUST be released
* with dmu_buf_rele_array. You can NOT release the hold on each buffer
* individually with dmu_buf_rele.
*/
int dmu_buf_hold_array(objset_t *os, uint64_t object, uint64_t offset,
uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp);
int dmu_buf_hold_array_by_bonus(dmu_buf_t *db, uint64_t offset,
uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp);
void dmu_buf_rele_array(dmu_buf_t **, int numbufs, void *tag);
/*
* Returns NULL on success, or the existing user ptr if it's already
* been set.
*
* user_ptr is for use by the user and can be obtained via dmu_buf_get_user().
*
* user_data_ptr_ptr should be NULL, or a pointer to a pointer which
* will be set to db->db_data when you are allowed to access it. Note
* that db->db_data (the pointer) can change when you do dmu_buf_read(),
* dmu_buf_tryupgrade(), dmu_buf_will_dirty(), or dmu_buf_will_fill().
* *user_data_ptr_ptr will be set to the new value when it changes.
*
* If non-NULL, pageout func will be called when this buffer is being
* excised from the cache, so that you can clean up the data structure
* pointed to by user_ptr.
*
* dmu_evict_user() will call the pageout func for all buffers in a
* objset with a given pageout func.
*/
void *dmu_buf_set_user(dmu_buf_t *db, void *user_ptr, void *user_data_ptr_ptr,
dmu_buf_evict_func_t *pageout_func);
/*
* set_user_ie is the same as set_user, but request immediate eviction
* when hold count goes to zero.
*/
void *dmu_buf_set_user_ie(dmu_buf_t *db, void *user_ptr,
void *user_data_ptr_ptr, dmu_buf_evict_func_t *pageout_func);
void *dmu_buf_update_user(dmu_buf_t *db_fake, void *old_user_ptr,
void *user_ptr, void *user_data_ptr_ptr,
dmu_buf_evict_func_t *pageout_func);
void dmu_evict_user(objset_t *os, dmu_buf_evict_func_t *func);
void dmu_buf_hold_data(dmu_buf_t *db);
void dmu_buf_rele_data(dmu_buf_t *db);
/*
* Returns the user_ptr set with dmu_buf_set_user(), or NULL if not set.
*/
void *dmu_buf_get_user(dmu_buf_t *db);
/*
* Indicate that you are going to modify the buffer's data (db_data).
*
* The transaction (tx) must be assigned to a txg (ie. you've called
* dmu_tx_assign()). The buffer's object must be held in the tx
* (ie. you've called dmu_tx_hold_object(tx, db->db_object)).
*/
void dmu_buf_will_dirty(dmu_buf_t *db, dmu_tx_t *tx);
/*
* You must create a transaction, then hold the objects which you will
* (or might) modify as part of this transaction. Then you must assign
* the transaction to a transaction group. Once the transaction has
* been assigned, you can modify buffers which belong to held objects as
* part of this transaction. You can't modify buffers before the
* transaction has been assigned; you can't modify buffers which don't
* belong to objects which this transaction holds; you can't hold
* objects once the transaction has been assigned. You may hold an
* object which you are going to free (with dmu_object_free()), but you
* don't have to.
*
* You can abort the transaction before it has been assigned.
*
* Note that you may hold buffers (with dmu_buf_hold) at any time,
* regardless of transaction state.
*/
#define DMU_NEW_OBJECT (-1ULL)
#define DMU_OBJECT_END (-1ULL)
dmu_tx_t *dmu_tx_create(objset_t *os);
void dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len);
void dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off,
uint64_t len);
void dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, char *name);
void dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object);
void dmu_tx_abort(dmu_tx_t *tx);
int dmu_tx_assign(dmu_tx_t *tx, uint64_t txg_how);
void dmu_tx_wait(dmu_tx_t *tx);
void dmu_tx_commit(dmu_tx_t *tx);
/*
* Free up the data blocks for a defined range of a file. If size is
* zero, the range from offset to end-of-file is freed.
*/
int dmu_free_range(objset_t *os, uint64_t object, uint64_t offset,
uint64_t size, dmu_tx_t *tx);
/*
* Convenience functions.
*
* Canfail routines will return 0 on success, or an errno if there is a
* nonrecoverable I/O error.
*/
int dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
void *buf);
void dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
const void *buf, dmu_tx_t *tx);
int dmu_write_uio(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
struct uio *uio, dmu_tx_t *tx);
/*
* Asynchronously try to read in the data.
*/
void dmu_prefetch(objset_t *os, uint64_t object, uint64_t offset,
uint64_t len);
typedef struct dmu_object_info {
/* All sizes are in bytes. */
uint32_t doi_data_block_size;
uint32_t doi_metadata_block_size;
uint64_t doi_bonus_size;
dmu_object_type_t doi_type;
dmu_object_type_t doi_bonus_type;
uint8_t doi_indirection; /* 2 = dnode->indirect->data */
uint8_t doi_checksum;
uint8_t doi_compress;
uint8_t doi_pad[5];
/* Values below are number of 512-byte blocks. */
uint64_t doi_physical_blks; /* data + metadata */
uint64_t doi_max_block_offset;
} dmu_object_info_t;
typedef struct dmu_object_type_info {
dmu_byteswap_func_t *ot_byteswap;
boolean_t ot_metadata;
char *ot_name;
} dmu_object_type_info_t;
extern const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES];
/*
* Get information on a DMU object.
*
* Return 0 on success or ENOENT if object is not allocated.
*
* If doi is NULL, just indicates whether the object exists.
*/
int dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi);
void dmu_object_info_from_dnode(struct dnode *dn, dmu_object_info_t *doi);
void dmu_object_info_from_db(dmu_buf_t *db, dmu_object_info_t *doi);
void dmu_object_size_from_db(dmu_buf_t *db, uint32_t *blksize,
u_longlong_t *nblk512);
/*
* Get the maximum nonzero offset in the object (ie. this offset and all
* offsets following are zero).
*
* XXX Perhaps integrate this with dmu_object_info(), although that
* would then have to bring in the indirect blocks.
*/
uint64_t dmu_object_max_nonzero_offset(objset_t *os, uint64_t object);
typedef struct dmu_objset_stats {
dmu_objset_type_t dds_type;
uint8_t dds_is_snapshot;
uint8_t dds_inconsistent;
uint8_t dds_pad[2];
uint64_t dds_creation_time;
uint64_t dds_creation_txg;
char dds_clone_of[MAXNAMELEN];
/* How much data is there in this objset? */
/*
* Space referenced, taking into account pending writes and
* frees. Only relavent to filesystems and snapshots (not
* collections).
*/
uint64_t dds_space_refd;
/*
* Space "used", taking into account pending writes and frees, and
* children's reservations (in bytes). This is the amount of
* space that will be freed if this and all dependent items are
* destroyed (eg. child datasets, objsets, and snapshots). So
* for snapshots, this is the amount of space unique to this
* snapshot.
*/
uint64_t dds_space_used;
/*
* Compressed and uncompressed bytes consumed. Does not take
* into account reservations. Used for computing compression
* ratio.
*/
uint64_t dds_compressed_bytes;
uint64_t dds_uncompressed_bytes;
/*
* The ds_fsid_guid is a 56-bit ID that can change to avoid
* collisions. The ds_guid is a 64-bit ID that will never
* change, so there is a small probability that it will collide.
*/
uint64_t dds_fsid_guid;
uint64_t dds_objects_used; /* number of objects used */
uint64_t dds_objects_avail; /* number of objects available */
uint64_t dds_num_clones; /* number of clones of this */
/* The dataset's administratively-set quota, in bytes. */
uint64_t dds_quota;
/* The dataset's administratively-set reservation, in bytes */
uint64_t dds_reserved;
/*
* The amount of additional space that this dataset can consume.
* Takes into account quotas & reservations.
* (Assuming that no other datasets consume it first.)
*/
uint64_t dds_available;
/*
* Used for debugging purposes
*/
uint64_t dds_last_txg;
} dmu_objset_stats_t;
/*
* Get stats on a dataset.
*/
void dmu_objset_stats(objset_t *os, dmu_objset_stats_t *dds);
int dmu_objset_is_snapshot(objset_t *os);
extern struct spa *dmu_objset_spa(objset_t *os);
extern struct zilog *dmu_objset_zil(objset_t *os);
extern struct dsl_pool *dmu_objset_pool(objset_t *os);
extern struct dsl_dataset *dmu_objset_ds(objset_t *os);
extern void dmu_objset_name(objset_t *os, char *buf);
extern dmu_objset_type_t dmu_objset_type(objset_t *os);
extern uint64_t dmu_objset_id(objset_t *os);
extern int dmu_snapshot_list_next(objset_t *os, int namelen, char *name,
uint64_t *id, uint64_t *offp);
extern int dmu_dir_list_next(objset_t *os, int namelen, char *name,
uint64_t *idp, uint64_t *offp);
/*
* Return the txg number for the given assigned transaction.
*/
uint64_t dmu_tx_get_txg(dmu_tx_t *tx);
/*
* Synchronous write.
* If a parent zio is provided this function initiates a write on the
* provided buffer as a child of the parent zio.
* In the absense of a parent zio, the write is completed synchronously.
* At write completion, blk is filled with the bp of the written block.
* Note that while the data covered by this function will be on stable
* storage when the write completes this new data does not become a
* permanent part of the file until the associated transaction commits.
*/
typedef void dmu_sync_cb_t(dmu_buf_t *db, void *arg);
int dmu_sync(struct zio *zio, dmu_buf_t *db,
struct blkptr *bp, uint64_t txg, dmu_sync_cb_t *done, void *arg);
/*
* Find the next hole or data block in file starting at *off
* Return found offset in *off. Return ESRCH for end of file.
*/
int dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole,
uint64_t *off);
/*
* Initial setup and final teardown.
*/
extern void dmu_init(void);
extern void dmu_fini(void);
typedef void (*dmu_traverse_cb_t)(objset_t *os, void *arg, struct blkptr *bp,
uint64_t object, uint64_t offset, int len);
void dmu_traverse_objset(objset_t *os, uint64_t txg_start,
dmu_traverse_cb_t cb, void *arg);
int dmu_sendbackup(objset_t *tosnap, objset_t *fromsnap, struct vnode *vp);
int dmu_recvbackup(char *tosnap, struct drr_begin *drrb, uint64_t *sizep,
struct vnode *vp, uint64_t voffset);
/* CRC64 table */
#define ZFS_CRC64_POLY 0xC96C5795D7870F42ULL /* ECMA-182, reflected form */
extern uint64_t zfs_crc64_table[256];
#ifdef __cplusplus
}
#endif
#endif /* _SYS_DMU_H */