dmu_impl.h revision fa9e4066f08beec538e775443c5be79dd423fcab
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (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
* 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 2005 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#ifndef _SYS_DMU_IMPL_H
#define _SYS_DMU_IMPL_H
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sys/txg_impl.h>
#include <sys/zfs_context.h>
#ifdef __cplusplus
extern "C" {
#endif
/*
* This is the locking strategy for the DMU. Numbers in parenthesis are
* cases that use that lock order, referenced below:
*
* ARC is self-contained
* bplist is self-contained
* refcount is self-contained
* txg is self-contained (hopefully!)
* zst_lock
* zf_rwlock
*
* XXX try to improve evicting path?
*
* dp_config_rwlock > os_obj_lock > dn_struct_rwlock >
* dn_dbufs_mtx > hash_mutexes > db_mtx > leafs
*
* dp_config_rwlock
* must be held before: everything
* protects dd namespace changes
* protects property changes globally
* held from:
* dsl_dir_open/r:
* dsl_dir_create_sync/w:
* dsl_dir_sync_destroy/w:
* dsl_dir_rename_sync/w:
* dsl_prop_changed_notify/r:
*
* os_obj_lock
* must be held before:
* everything except dp_config_rwlock
* protects os_obj_next
* held from:
* dmu_object_alloc: dn_dbufs_mtx, db_mtx, hash_mutexes, dn_struct_rwlock
*
* dn_struct_rwlock
* must be held before:
* everything except dp_config_rwlock and os_obj_lock
* protects structure of dnode (eg. nlevels)
* db_blkptr can change when syncing out change to nlevels
* dn_maxblkid
* dn_nlevels
* dn_*blksz*
* phys nlevels, maxblkid, physical blkptr_t's (?)
* held from:
* callers of dbuf_read_impl, dbuf_hold[_impl], dbuf_prefetch
* dmu_object_info_from_dnode: dn_dirty_mtx (dn_datablksz)
* dmu_tx_count_free:
* dbuf_read_impl: db_mtx, dmu_zfetch()
* dmu_zfetch: zf_rwlock/r, zst_lock, dbuf_prefetch()
* dbuf_new_size: db_mtx
* dbuf_dirty: db_mtx
* dbuf_findbp: (callers, phys? - the real need)
* dbuf_create: dn_dbufs_mtx, hash_mutexes, db_mtx (phys?)
* dbuf_prefetch: dn_dirty_mtx, hash_mutexes, db_mtx, dn_dbufs_mtx
* dbuf_hold_impl: hash_mutexes, db_mtx, dn_dbufs_mtx, dbuf_findbp()
* dnode_sync/w (increase_indirection): db_mtx (phys)
* dnode_set_blksz/w: dn_dbufs_mtx (dn_*blksz*)
* dnode_new_blkid/w: (dn_maxblkid)
* dnode_free_range/w: dn_dirty_mtx (dn_maxblkid)
* dnode_next_offset: (phys)
*
* dn_dbufs_mtx
* must be held before:
* db_mtx, hash_mutexes
* protects:
* dn_dbufs
* dn_evicted
* held from:
* dmu_evict_user: db_mtx (dn_dbufs)
* dbuf_free_range: db_mtx (dn_dbufs)
* dbuf_remove_ref: db_mtx, callees:
* dbuf_hash_remove: hash_mutexes, db_mtx
* dbuf_create: hash_mutexes, db_mtx (dn_dbufs)
* dnode_set_blksz: (dn_dbufs)
*
* hash_mutexes (global)
* must be held before:
* db_mtx
* protects dbuf_hash_table (global) and db_hash_next
* held from:
* dbuf_find: db_mtx
* dbuf_hash_insert: db_mtx
* dbuf_hash_remove: db_mtx
*
* db_mtx (meta-leaf)
* must be held before:
* dn_mtx, dn_dirty_mtx, dd_lock (leaf mutexes)
* protects:
* db_state
* db_holds
* db_buf
* db_changed
* db_data_pending
* db_dirtied
* db_link
* db_dirty_node (??)
* db_dirtycnt
* db_d.*
* db.*
* held from:
* dbuf_dirty: dn_mtx, dn_dirty_mtx
* dbuf_dirty->dsl_dir_willuse_space: dd_lock
* dbuf_dirty->dbuf_new_block->dsl_dataset_block_freeable: dd_lock
* dbuf_undirty: dn_dirty_mtx (db_d)
* dbuf_write_done: dn_dirty_mtx (db_state)
* dbuf_*
* dmu_buf_update_user: none (db_d)
* dmu_evict_user: none (db_d) (maybe can eliminate)
* dbuf_find: none (db_holds)
* dbuf_hash_insert: none (db_holds)
* dmu_buf_read_array_impl: none (db_state, db_changed)
* dmu_sync: none (db_dirty_node, db_d)
* dnode_reallocate: none (db)
*
* dn_mtx (leaf)
* protects:
* dn_dirty_dbufs
* dn_ranges
* phys accounting
* dn_allocated_txg
* dn_free_txg
* dn_assigned_txg
* dd_assigned_tx
* dn_notxholds
* dn_dirtyctx
* dn_dirtyctx_firstset
* (dn_phys copy fields?)
* (dn_phys contents?)
* held from:
* dnode_*
* dbuf_dirty: none
* dbuf_sync: none (phys accounting)
* dbuf_undirty: none (dn_ranges, dn_dirty_dbufs)
* dbuf_write_done: none (phys accounting)
* dmu_object_info_from_dnode: none (accounting)
* dmu_tx_commit: none
* dmu_tx_hold_object_impl: none
* dmu_tx_try_assign: dn_notxholds(cv)
* dmu_tx_unassign: none
*
* dd_lock (leaf)
* protects:
* dd_prop_cbs
* dd_sync_*
* dd_used_bytes
* dd_tempreserved
* dd_space_towrite
* dd_myname
* dd_phys accounting?
* held from:
* dsl_dir_*
* dsl_prop_changed_notify: none (dd_prop_cbs)
* dsl_prop_register: none (dd_prop_cbs)
* dsl_prop_unregister: none (dd_prop_cbs)
* dsl_dataset_block_freeable: none (dd_sync_*)
*
* os_lock (leaf)
* protects:
* os_dirty_dnodes
* os_free_dnodes
* os_dnodes
* os_downgraded_dbufs
* dn_dirtyblksz
* dn_dirty_link
* held from:
* dnode_create: none (os_dnodes)
* dnode_destroy: none (os_dnodes)
* dnode_setdirty: none (dn_dirtyblksz, os_*_dnodes)
* dnode_free: none (dn_dirtyblksz, os_*_dnodes)
*
* ds_lock (leaf)
* protects:
* ds_user_ptr
* ds_user_evice_func
* ds_open_refcount
* ds_snapname
* ds_phys accounting
* held from:
* dsl_dataset_*
*
*/
struct objset;
struct dmu_pool;
#ifdef __cplusplus
}
#endif
#endif /* _SYS_DMU_IMPL_H */