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15 * If applicable, add the following below this CDDL HEADER, with the
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22 * Copyright 2010 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
26 #ifndef _SYS_DMU_IMPL_H
27 #define _SYS_DMU_IMPL_H
29 #include <sys/txg_impl.h>
31 #include <sys/dnode.h>
32 #include <sys/kstat.h>
33 #include <sys/zfs_context.h>
40 * This is the locking strategy for the DMU. Numbers in parenthesis are
41 * cases that use that lock order, referenced below:
43 * ARC is self-contained
44 * bplist is self-contained
45 * refcount is self-contained
46 * txg is self-contained (hopefully!)
50 * XXX try to improve evicting path?
52 * dp_config_rwlock > os_obj_lock > dn_struct_rwlock >
53 * dn_dbufs_mtx > hash_mutexes > db_mtx > dd_lock > leafs
56 * must be held before: everything
57 * protects dd namespace changes
58 * protects property changes globally
61 * dsl_dir_create_sync/w:
62 * dsl_dir_sync_destroy/w:
63 * dsl_dir_rename_sync/w:
64 * dsl_prop_changed_notify/r:
67 * must be held before:
68 * everything except dp_config_rwlock
69 * protects os_obj_next
71 * dmu_object_alloc: dn_dbufs_mtx, db_mtx, hash_mutexes, dn_struct_rwlock
74 * must be held before:
75 * everything except dp_config_rwlock and os_obj_lock
76 * protects structure of dnode (eg. nlevels)
77 * db_blkptr can change when syncing out change to nlevels
81 * phys nlevels, maxblkid, physical blkptr_t's (?)
83 * callers of dbuf_read_impl, dbuf_hold[_impl], dbuf_prefetch
84 * dmu_object_info_from_dnode: dn_dirty_mtx (dn_datablksz)
86 * dbuf_read_impl: db_mtx, dmu_zfetch()
87 * dmu_zfetch: zf_rwlock/r, zst_lock, dbuf_prefetch()
88 * dbuf_new_size: db_mtx
90 * dbuf_findbp: (callers, phys? - the real need)
91 * dbuf_create: dn_dbufs_mtx, hash_mutexes, db_mtx (phys?)
92 * dbuf_prefetch: dn_dirty_mtx, hash_mutexes, db_mtx, dn_dbufs_mtx
93 * dbuf_hold_impl: hash_mutexes, db_mtx, dn_dbufs_mtx, dbuf_findbp()
94 * dnode_sync/w (increase_indirection): db_mtx (phys)
95 * dnode_set_blksz/w: dn_dbufs_mtx (dn_*blksz*)
96 * dnode_new_blkid/w: (dn_maxblkid)
97 * dnode_free_range/w: dn_dirty_mtx (dn_maxblkid)
98 * dnode_next_offset: (phys)
101 * must be held before:
102 * db_mtx, hash_mutexes
107 * dmu_evict_user: db_mtx (dn_dbufs)
108 * dbuf_free_range: db_mtx (dn_dbufs)
109 * dbuf_remove_ref: db_mtx, callees:
110 * dbuf_hash_remove: hash_mutexes, db_mtx
111 * dbuf_create: hash_mutexes, db_mtx (dn_dbufs)
112 * dnode_set_blksz: (dn_dbufs)
114 * hash_mutexes (global)
115 * must be held before:
117 * protects dbuf_hash_table (global) and db_hash_next
120 * dbuf_hash_insert: db_mtx
121 * dbuf_hash_remove: db_mtx
124 * must be held before:
125 * dn_mtx, dn_dirty_mtx, dd_lock (leaf mutexes)
139 * dbuf_dirty: dn_mtx, dn_dirty_mtx
140 * dbuf_dirty->dsl_dir_willuse_space: dd_lock
141 * dbuf_dirty->dbuf_new_block->dsl_dataset_block_freeable: dd_lock
142 * dbuf_undirty: dn_dirty_mtx (db_d)
143 * dbuf_write_done: dn_dirty_mtx (db_state)
145 * dmu_buf_update_user: none (db_d)
146 * dmu_evict_user: none (db_d) (maybe can eliminate)
147 * dbuf_find: none (db_holds)
148 * dbuf_hash_insert: none (db_holds)
149 * dmu_buf_read_array_impl: none (db_state, db_changed)
150 * dmu_sync: none (db_dirty_node, db_d)
151 * dnode_reallocate: none (db)
164 * dn_dirtyctx_firstset
165 * (dn_phys copy fields?)
166 * (dn_phys contents?)
170 * dbuf_sync: none (phys accounting)
171 * dbuf_undirty: none (dn_ranges, dn_dirty_dbufs)
172 * dbuf_write_done: none (phys accounting)
173 * dmu_object_info_from_dnode: none (accounting)
174 * dmu_tx_commit: none
175 * dmu_tx_hold_object_impl: none
176 * dmu_tx_try_assign: dn_notxholds(cv)
177 * dmu_tx_unassign: none
180 * must be held before:
190 * dd_phys accounting?
193 * dsl_prop_changed_notify: none (dd_prop_cbs)
194 * dsl_prop_register: none (dd_prop_cbs)
195 * dsl_prop_unregister: none (dd_prop_cbs)
196 * dsl_dataset_block_freeable: none (dd_sync_*)
203 * os_downgraded_dbufs
207 * dnode_create: none (os_dnodes)
208 * dnode_destroy: none (os_dnodes)
209 * dnode_setdirty: none (dn_dirtyblksz, os_*_dnodes)
210 * dnode_free: none (dn_dirtyblksz, os_*_dnodes)
218 * ds_phys userrefs zapobj
236 typedef struct dmu_xuio {
239 struct arc_buf **bufs;
243 typedef struct xuio_stats {
244 /* loaned yet not returned arc_buf */
245 kstat_named_t xuiostat_onloan_rbuf;
246 kstat_named_t xuiostat_onloan_wbuf;
247 /* whether a copy is made when loaning out a read buffer */
248 kstat_named_t xuiostat_rbuf_copied;
249 kstat_named_t xuiostat_rbuf_nocopy;
250 /* whether a copy is made when assigning a write buffer */
251 kstat_named_t xuiostat_wbuf_copied;
252 kstat_named_t xuiostat_wbuf_nocopy;
255 static xuio_stats_t xuio_stats = {
256 { "onloan_read_buf", KSTAT_DATA_UINT64 },
257 { "onloan_write_buf", KSTAT_DATA_UINT64 },
258 { "read_buf_copied", KSTAT_DATA_UINT64 },
259 { "read_buf_nocopy", KSTAT_DATA_UINT64 },
260 { "write_buf_copied", KSTAT_DATA_UINT64 },
261 { "write_buf_nocopy", KSTAT_DATA_UINT64 }
264 #define XUIOSTAT_INCR(stat, val) \
265 atomic_add_64(&xuio_stats.stat.value.ui64, (val))
266 #define XUIOSTAT_BUMP(stat) XUIOSTAT_INCR(stat, 1)
273 #endif /* _SYS_DMU_IMPL_H */