FreeBSD/Linux Kernel Cross Reference
sys/contrib/openzfs/include/sys/dmu_impl.h

     /*
      * 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 https://opensource.org/licenses/CDDL-1.0.
     * 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 2010 Sun Microsystems, Inc.  All rights reserved.
     * Use is subject to license terms.
     */
    /*
     * Copyright (c) 2012, Joyent, Inc. All rights reserved.
     * Copyright (c) 2013, 2018 by Delphix. All rights reserved.
     */
    
    #ifndef _SYS_DMU_IMPL_H
    #define _SYS_DMU_IMPL_H
    
    #include <sys/txg_impl.h>
    #include <sys/zio.h>
    #include <sys/dnode.h>
    #include <sys/zfs_context.h>
    #include <sys/zfs_ioctl.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 > dd_lock > 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)
     *      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
    *      dn_dirty_txg
    *      dd_assigned_tx
    *      dn_notxholds
    *      dn_nodnholds
    *      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
    *    must be held before:
    *      ds_lock
    *      ancestors' dd_lock
    *    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)
    *
    * 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
    *    protects:
    *      ds_objset
    *      ds_open_refcount
    *      ds_snapname
    *      ds_phys accounting
    *      ds_phys userrefs zapobj
    *      ds_reserved
    *    held from:
    *      dsl_dataset_*
    *
    * dr_mtx (leaf)
    *    protects:
    *      dr_children
    *    held from:
    *      dbuf_dirty
    *      dbuf_undirty
    *      dbuf_sync_indirect
    *      dnode_new_blkid
    */
   
   struct objset;
   struct dmu_pool;
   
   typedef struct dmu_sendstatus {
           list_node_t dss_link;
           int dss_outfd;
           proc_t *dss_proc;
           offset_t *dss_off;
           uint64_t dss_blocks; /* blocks visited during the sending process */
   } dmu_sendstatus_t;
   
   void dmu_object_zapify(objset_t *, uint64_t, dmu_object_type_t, dmu_tx_t *);
   void dmu_object_free_zapified(objset_t *, uint64_t, dmu_tx_t *);
   int dmu_buf_hold_noread(objset_t *, uint64_t, uint64_t,
       const void *, dmu_buf_t **);
   
   #ifdef  __cplusplus
   }
   #endif
   
   #endif  /* _SYS_DMU_IMPL_H */

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