include/sys/dmu_impl.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 https://opensource.org/licenses/CDDL-1.0.
  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 2010 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25 /*
  26  * Copyright (c) 2012, Joyent, Inc. All rights reserved.
  27  * Copyright (c) 2013, 2018 by Delphix. All rights reserved.
  28  */
  29
  30 #ifndef _SYS_DMU_IMPL_H
  31 #define _SYS_DMU_IMPL_H
  32
  33 #include <sys/txg_impl.h>
  34 #include <sys/zio.h>
  35 #include <sys/dnode.h>
  36 #include <sys/zfs_context.h>
  37 #include <sys/zfs_ioctl.h>
  38
  39 #ifdef  __cplusplus
  40 extern "C" {
  41 #endif
  42
  43 /*
  44  * This is the locking strategy for the DMU.  Numbers in parenthesis are
  45  * cases that use that lock order, referenced below:
  46  *
  47  * ARC is self-contained
  48  * bplist is self-contained
  49  * refcount is self-contained
  50  * txg is self-contained (hopefully!)
  51  * zst_lock
  52  * zf_rwlock
  53  *
  54  * XXX try to improve evicting path?
  55  *
  56  * dp_config_rwlock > os_obj_lock > dn_struct_rwlock >
  57  *      dn_dbufs_mtx > hash_mutexes > db_mtx > dd_lock > leafs
  58  *
  59  * dp_config_rwlock
  60  *    must be held before: everything
  61  *    protects dd namespace changes
  62  *    protects property changes globally
  63  *    held from:
  64  *      dsl_dir_open/r:
  65  *      dsl_dir_create_sync/w:
  66  *      dsl_dir_sync_destroy/w:
  67  *      dsl_dir_rename_sync/w:
  68  *      dsl_prop_changed_notify/r:
  69  *
  70  * os_obj_lock
  71  *   must be held before:
  72  *      everything except dp_config_rwlock
  73  *   protects os_obj_next
  74  *   held from:
  75  *      dmu_object_alloc: dn_dbufs_mtx, db_mtx, hash_mutexes, dn_struct_rwlock
  76  *
  77  * dn_struct_rwlock
  78  *   must be held before:
  79  *      everything except dp_config_rwlock and os_obj_lock
  80  *   protects structure of dnode (eg. nlevels)
  81  *      db_blkptr can change when syncing out change to nlevels
  82  *      dn_maxblkid
  83  *      dn_nlevels
  84  *      dn_*blksz*
  85  *      phys nlevels, maxblkid, physical blkptr_t's (?)
  86  *   held from:
  87  *      callers of dbuf_read_impl, dbuf_hold[_impl], dbuf_prefetch
  88  *      dmu_object_info_from_dnode: dn_dirty_mtx (dn_datablksz)
  89  *      dbuf_read_impl: db_mtx, dmu_zfetch()
  90  *      dmu_zfetch: zf_rwlock/r, zst_lock, dbuf_prefetch()
  91  *      dbuf_new_size: db_mtx
  92  *      dbuf_dirty: db_mtx
  93  *      dbuf_findbp: (callers, phys? - the real need)
  94  *      dbuf_create: dn_dbufs_mtx, hash_mutexes, db_mtx (phys?)
  95  *      dbuf_prefetch: dn_dirty_mtx, hash_mutexes, db_mtx, dn_dbufs_mtx
  96  *      dbuf_hold_impl: hash_mutexes, db_mtx, dn_dbufs_mtx, dbuf_findbp()
  97  *      dnode_sync/w (increase_indirection): db_mtx (phys)
  98  *      dnode_set_blksz/w: dn_dbufs_mtx (dn_*blksz*)
  99  *      dnode_new_blkid/w: (dn_maxblkid)
 100  *      dnode_free_range/w: dn_dirty_mtx (dn_maxblkid)
 101  *      dnode_next_offset: (phys)
 102  *
 103  * dn_dbufs_mtx
 104  *    must be held before:
 105  *      db_mtx, hash_mutexes
 106  *    protects:
 107  *      dn_dbufs
 108  *      dn_evicted
 109  *    held from:
 110  *      dmu_evict_user: db_mtx (dn_dbufs)
 111  *      dbuf_free_range: db_mtx (dn_dbufs)
 112  *      dbuf_remove_ref: db_mtx, callees:
 113  *              dbuf_hash_remove: hash_mutexes, db_mtx
 114  *      dbuf_create: hash_mutexes, db_mtx (dn_dbufs)
 115  *      dnode_set_blksz: (dn_dbufs)
 116  *
 117  * hash_mutexes (global)
 118  *   must be held before:
 119  *      db_mtx
 120  *   protects dbuf_hash_table (global) and db_hash_next
 121  *   held from:
 122  *      dbuf_find: db_mtx
 123  *      dbuf_hash_insert: db_mtx
 124  *      dbuf_hash_remove: db_mtx
 125  *
 126  * db_mtx (meta-leaf)
 127  *   must be held before:
 128  *      dn_mtx, dn_dirty_mtx, dd_lock (leaf mutexes)
 129  *   protects:
 130  *      db_state
 131  *      db_holds
 132  *      db_buf
 133  *      db_changed
 134  *      db_data_pending
 135  *      db_dirtied
 136  *      db_link
 137  *      db_dirty_node (??)
 138  *      db_dirtycnt
 139  *      db_d.*
 140  *      db.*
 141  *   held from:
 142  *      dbuf_dirty: dn_mtx, dn_dirty_mtx
 143  *      dbuf_dirty->dsl_dir_willuse_space: dd_lock
 144  *      dbuf_dirty->dbuf_new_block->dsl_dataset_block_freeable: dd_lock
 145  *      dbuf_undirty: dn_dirty_mtx (db_d)
 146  *      dbuf_write_done: dn_dirty_mtx (db_state)
 147  *      dbuf_*
 148  *      dmu_buf_update_user: none (db_d)
 149  *      dmu_evict_user: none (db_d) (maybe can eliminate)
 150  *      dbuf_find: none (db_holds)
 151  *      dbuf_hash_insert: none (db_holds)
 152  *      dmu_buf_read_array_impl: none (db_state, db_changed)
 153  *      dmu_sync: none (db_dirty_node, db_d)
 154  *      dnode_reallocate: none (db)
 155  *
 156  * dn_mtx (leaf)
 157  *   protects:
 158  *      dn_dirty_dbufs
 159  *      dn_ranges
 160  *      phys accounting
 161  *      dn_allocated_txg
 162  *      dn_free_txg
 163  *      dn_assigned_txg
 164  *      dn_dirty_txg
 165  *      dd_assigned_tx
 166  *      dn_notxholds
 167  *      dn_nodnholds
 168  *      dn_dirtyctx
 169  *      dn_dirtyctx_firstset
 170  *      (dn_phys copy fields?)
 171  *      (dn_phys contents?)
 172  *   held from:
 173  *      dnode_*
 174  *      dbuf_dirty: none
 175  *      dbuf_sync: none (phys accounting)
 176  *      dbuf_undirty: none (dn_ranges, dn_dirty_dbufs)
 177  *      dbuf_write_done: none (phys accounting)
 178  *      dmu_object_info_from_dnode: none (accounting)
 179  *      dmu_tx_commit: none
 180  *      dmu_tx_hold_object_impl: none
 181  *      dmu_tx_try_assign: dn_notxholds(cv)
 182  *      dmu_tx_unassign: none
 183  *
 184  * dd_lock
 185  *    must be held before:
 186  *      ds_lock
 187  *      ancestors' dd_lock
 188  *    protects:
 189  *      dd_prop_cbs
 190  *      dd_sync_*
 191  *      dd_used_bytes
 192  *      dd_tempreserved
 193  *      dd_space_towrite
 194  *      dd_myname
 195  *      dd_phys accounting?
 196  *    held from:
 197  *      dsl_dir_*
 198  *      dsl_prop_changed_notify: none (dd_prop_cbs)
 199  *      dsl_prop_register: none (dd_prop_cbs)
 200  *      dsl_prop_unregister: none (dd_prop_cbs)
 201  *
 202  * os_lock (leaf)
 203  *   protects:
 204  *      os_dirty_dnodes
 205  *      os_free_dnodes
 206  *      os_dnodes
 207  *      os_downgraded_dbufs
 208  *      dn_dirtyblksz
 209  *      dn_dirty_link
 210  *   held from:
 211  *      dnode_create: none (os_dnodes)
 212  *      dnode_destroy: none (os_dnodes)
 213  *      dnode_setdirty: none (dn_dirtyblksz, os_*_dnodes)
 214  *      dnode_free: none (dn_dirtyblksz, os_*_dnodes)
 215  *
 216  * ds_lock
 217  *    protects:
 218  *      ds_objset
 219  *      ds_open_refcount
 220  *      ds_snapname
 221  *      ds_phys accounting
 222  *      ds_phys userrefs zapobj
 223  *      ds_reserved
 224  *    held from:
 225  *      dsl_dataset_*
 226  *
 227  * dr_mtx (leaf)
 228  *    protects:
 229  *      dr_children
 230  *    held from:
 231  *      dbuf_dirty
 232  *      dbuf_undirty
 233  *      dbuf_sync_indirect
 234  *      dnode_new_blkid
 235  */
 236
 237 struct objset;
 238 struct dmu_pool;
 239
 240 typedef struct dmu_sendstatus {
 241         list_node_t dss_link;
 242         int dss_outfd;
 243         proc_t *dss_proc;
 244         offset_t *dss_off;
 245         uint64_t dss_blocks; /* blocks visited during the sending process */
 246 } dmu_sendstatus_t;
 247
 248 void dmu_object_zapify(objset_t *, uint64_t, dmu_object_type_t, dmu_tx_t *);
 249 void dmu_object_free_zapified(objset_t *, uint64_t, dmu_tx_t *);
 250 int dmu_buf_hold_noread(objset_t *, uint64_t, uint64_t,
 251     const void *, dmu_buf_t **);
 252
 253 #ifdef  __cplusplus
 254 }
 255 #endif
 256
 257 #endif  /* _SYS_DMU_IMPL_H */