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.
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
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]
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2012, 2018 by Delphix. All rights reserved.
24 * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
25 * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
36 #include <sys/zfs_context.h>
37 #include <sys/refcount.h>
38 #include <sys/zrlock.h>
39 #include <sys/multilist.h>
48 * define flags for dbuf_read
51 #define DB_RF_MUST_SUCCEED (1 << 0)
52 #define DB_RF_CANFAIL (1 << 1)
53 #define DB_RF_HAVESTRUCT (1 << 2)
54 #define DB_RF_NOPREFETCH (1 << 3)
55 #define DB_RF_NEVERWAIT (1 << 4)
56 #define DB_RF_CACHED (1 << 5)
59 * The simplified state transition diagram for dbufs looks like:
64 * (alloc)-->UNCACHED CACHED-->EVICTING-->(free)
70 * +--------> NOFILL -------+
72 * DB_SEARCH is an invalid state for a dbuf. It is used by dbuf_free_range
73 * to find all dbufs in a range of a dnode and must be less than any other
74 * dbuf_states_t (see comment on dn_dbufs in dnode.h).
76 typedef enum dbuf_states {
86 typedef enum dbuf_cached_state {
89 DB_DBUF_METADATA_CACHE,
91 } dbuf_cached_state_t;
97 * level = 0 means the user data
98 * level = 1 means the single indirect block
104 typedef enum override_states {
110 typedef struct dbuf_dirty_record {
111 /* link on our parents dirty list */
112 list_node_t dr_dirty_node;
114 /* transaction group this data will sync in */
117 /* zio of outstanding write IO */
120 /* pointer back to our dbuf */
121 struct dmu_buf_impl *dr_dbuf;
123 /* pointer to next dirty record */
124 struct dbuf_dirty_record *dr_next;
126 /* pointer to parent dirty record */
127 struct dbuf_dirty_record *dr_parent;
129 /* How much space was changed to dsl_pool_dirty_space() for this? */
130 unsigned int dr_accounted;
132 /* A copy of the bp that points to us */
136 struct dirty_indirect {
138 /* protect access to list */
141 /* Our list of dirty children */
147 * dr_data is set when we dirty the buffer
148 * so that we can retain the pointer even if it
149 * gets COW'd in a subsequent transaction group.
152 blkptr_t dr_overridden_by;
153 override_states_t dr_override_state;
155 boolean_t dr_nopwrite;
158 } dbuf_dirty_record_t;
160 typedef struct dmu_buf_impl {
162 * The following members are immutable, with the exception of
163 * db.db_data, which is protected by db_mtx.
166 /* the publicly visible structure */
169 /* the objset we belong to */
170 struct objset *db_objset;
173 * handle to safely access the dnode we belong to (NULL when evicted)
175 struct dnode_handle *db_dnode_handle;
178 * our parent buffer; if the dnode points to us directly,
179 * db_parent == db_dnode_handle->dnh_dnode->dn_dbuf
180 * only accessed by sync thread ???
181 * (NULL when evicted)
182 * May change from NULL to non-NULL under the protection of db_mtx
183 * (see dbuf_check_blkptr())
185 struct dmu_buf_impl *db_parent;
188 * link for hash table of all dmu_buf_impl_t's
190 struct dmu_buf_impl *db_hash_next;
192 /* our block number */
196 * Pointer to the blkptr_t which points to us. May be NULL if we
197 * don't have one yet. (NULL when evicted)
202 * Our indirection level. Data buffers have db_level==0.
203 * Indirect buffers which point to data buffers have
204 * db_level==1. etc. Buffers which contain dnodes have
205 * db_level==0, since the dnodes are stored in a file.
209 /* db_mtx protects the members below */
213 * Current state of the buffer
215 dbuf_states_t db_state;
218 * Refcount accessed by dmu_buf_{hold,rele}.
219 * If nonzero, the buffer can't be destroyed.
220 * Protected by db_mtx.
224 /* buffer holding our data */
227 kcondvar_t db_changed;
228 dbuf_dirty_record_t *db_data_pending;
230 /* pointer to most recent dirty record for this buffer */
231 dbuf_dirty_record_t *db_last_dirty;
234 * Our link on the owner dnodes's dn_dbufs list.
235 * Protected by its dn_dbufs_mtx.
239 /* Link in dbuf_cache or dbuf_metadata_cache */
240 multilist_node_t db_cache_link;
242 /* Tells us which dbuf cache this dbuf is in, if any */
243 dbuf_cached_state_t db_caching_status;
245 /* Data which is unique to data (leaf) blocks: */
247 /* User callback information. */
248 dmu_buf_user_t *db_user;
251 * Evict user data as soon as the dirty and reference
254 uint8_t db_user_immediate_evict;
257 * This block was freed while a read or write was
260 uint8_t db_freed_in_flight;
263 * dnode_evict_dbufs() or dnode_evict_bonus() tried to
264 * evict this dbuf, but couldn't due to outstanding
265 * references. Evict once the refcount drops to 0.
267 uint8_t db_pending_evict;
272 /* Note: the dbuf hash table is exposed only for the mdb module */
273 #define DBUF_MUTEXES 256
274 #define DBUF_HASH_MUTEX(h, idx) (&(h)->hash_mutexes[(idx) & (DBUF_MUTEXES-1)])
275 typedef struct dbuf_hash_table {
276 uint64_t hash_table_mask;
277 dmu_buf_impl_t **hash_table;
278 kmutex_t hash_mutexes[DBUF_MUTEXES];
281 uint64_t dbuf_whichblock(struct dnode *di, int64_t level, uint64_t offset);
283 dmu_buf_impl_t *dbuf_create_tlib(struct dnode *dn, char *data);
284 void dbuf_create_bonus(struct dnode *dn);
285 int dbuf_spill_set_blksz(dmu_buf_t *db, uint64_t blksz, dmu_tx_t *tx);
286 void dbuf_spill_hold(struct dnode *dn, dmu_buf_impl_t **dbp, void *tag);
288 void dbuf_rm_spill(struct dnode *dn, dmu_tx_t *tx);
290 dmu_buf_impl_t *dbuf_hold(struct dnode *dn, uint64_t blkid, void *tag);
291 dmu_buf_impl_t *dbuf_hold_level(struct dnode *dn, int level, uint64_t blkid,
293 int dbuf_hold_impl(struct dnode *dn, uint8_t level, uint64_t blkid,
294 boolean_t fail_sparse, boolean_t fail_uncached,
295 void *tag, dmu_buf_impl_t **dbp);
297 void dbuf_prefetch(struct dnode *dn, int64_t level, uint64_t blkid,
298 zio_priority_t prio, arc_flags_t aflags);
300 void dbuf_add_ref(dmu_buf_impl_t *db, void *tag);
301 boolean_t dbuf_try_add_ref(dmu_buf_t *db, objset_t *os, uint64_t obj,
302 uint64_t blkid, void *tag);
303 uint64_t dbuf_refcount(dmu_buf_impl_t *db);
305 void dbuf_rele(dmu_buf_impl_t *db, void *tag);
306 void dbuf_rele_and_unlock(dmu_buf_impl_t *db, void *tag, boolean_t evicting);
308 dmu_buf_impl_t *dbuf_find(struct objset *os, uint64_t object, uint8_t level,
311 int dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags);
312 void dmu_buf_will_not_fill(dmu_buf_t *db, dmu_tx_t *tx);
313 void dmu_buf_will_fill(dmu_buf_t *db, dmu_tx_t *tx);
314 void dmu_buf_fill_done(dmu_buf_t *db, dmu_tx_t *tx);
315 void dbuf_assign_arcbuf(dmu_buf_impl_t *db, arc_buf_t *buf, dmu_tx_t *tx);
316 dbuf_dirty_record_t *dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx);
317 arc_buf_t *dbuf_loan_arcbuf(dmu_buf_impl_t *db);
318 void dmu_buf_write_embedded(dmu_buf_t *dbuf, void *data,
319 bp_embedded_type_t etype, enum zio_compress comp,
320 int uncompressed_size, int compressed_size, int byteorder, dmu_tx_t *tx);
322 void dbuf_destroy(dmu_buf_impl_t *db);
324 void dbuf_setdirty(dmu_buf_impl_t *db, dmu_tx_t *tx);
325 void dbuf_unoverride(dbuf_dirty_record_t *dr);
326 void dbuf_sync_list(list_t *list, int level, dmu_tx_t *tx);
327 void dbuf_release_bp(dmu_buf_impl_t *db);
329 boolean_t dbuf_can_remap(const dmu_buf_impl_t *buf);
331 void dbuf_free_range(struct dnode *dn, uint64_t start, uint64_t end,
334 void dbuf_new_size(dmu_buf_impl_t *db, int size, dmu_tx_t *tx);
336 void dbuf_stats_init(dbuf_hash_table_t *hash);
337 void dbuf_stats_destroy(void);
339 #define DB_DNODE(_db) ((_db)->db_dnode_handle->dnh_dnode)
340 #define DB_DNODE_LOCK(_db) ((_db)->db_dnode_handle->dnh_zrlock)
341 #define DB_DNODE_ENTER(_db) (zrl_add(&DB_DNODE_LOCK(_db)))
342 #define DB_DNODE_EXIT(_db) (zrl_remove(&DB_DNODE_LOCK(_db)))
343 #define DB_DNODE_HELD(_db) (!zrl_is_zero(&DB_DNODE_LOCK(_db)))
345 void dbuf_init(void);
346 void dbuf_fini(void);
348 boolean_t dbuf_is_metadata(dmu_buf_impl_t *db);
350 #define DBUF_GET_BUFC_TYPE(_db) \
351 (dbuf_is_metadata(_db) ? ARC_BUFC_METADATA : ARC_BUFC_DATA)
353 #define DBUF_IS_CACHEABLE(_db) \
354 ((_db)->db_objset->os_primary_cache == ZFS_CACHE_ALL || \
355 (dbuf_is_metadata(_db) && \
356 ((_db)->db_objset->os_primary_cache == ZFS_CACHE_METADATA)))
358 #define DBUF_IS_L2CACHEABLE(_db) \
359 ((_db)->db_objset->os_secondary_cache == ZFS_CACHE_ALL || \
360 (dbuf_is_metadata(_db) && \
361 ((_db)->db_objset->os_secondary_cache == ZFS_CACHE_METADATA)))
363 #define DNODE_LEVEL_IS_L2CACHEABLE(_dn, _level) \
364 ((_dn)->dn_objset->os_secondary_cache == ZFS_CACHE_ALL || \
366 DMU_OT_IS_METADATA((_dn)->dn_handle->dnh_dnode->dn_type)) && \
367 ((_dn)->dn_objset->os_secondary_cache == ZFS_CACHE_METADATA)))
372 * There should be a ## between the string literal and fmt, to make it
373 * clear that we're joining two strings together, but gcc does not
374 * support that preprocessor token.
376 #define dprintf_dbuf(dbuf, fmt, ...) do { \
377 if (zfs_flags & ZFS_DEBUG_DPRINTF) { \
379 uint64_t __db_obj = (dbuf)->db.db_object; \
380 if (__db_obj == DMU_META_DNODE_OBJECT) \
381 (void) strcpy(__db_buf, "mdn"); \
383 (void) snprintf(__db_buf, sizeof (__db_buf), "%lld", \
384 (u_longlong_t)__db_obj); \
385 dprintf_ds((dbuf)->db_objset->os_dsl_dataset, \
386 "obj=%s lvl=%u blkid=%lld " fmt, \
387 __db_buf, (dbuf)->db_level, \
388 (u_longlong_t)(dbuf)->db_blkid, __VA_ARGS__); \
390 _NOTE(CONSTCOND) } while (0)
392 #define dprintf_dbuf_bp(db, bp, fmt, ...) do { \
393 if (zfs_flags & ZFS_DEBUG_DPRINTF) { \
394 char *__blkbuf = kmem_alloc(BP_SPRINTF_LEN, KM_SLEEP); \
395 snprintf_blkptr(__blkbuf, BP_SPRINTF_LEN, bp); \
396 dprintf_dbuf(db, fmt " %s\n", __VA_ARGS__, __blkbuf); \
397 kmem_free(__blkbuf, BP_SPRINTF_LEN); \
399 _NOTE(CONSTCOND) } while (0)
401 #define DBUF_VERIFY(db) dbuf_verify(db)
405 #define dprintf_dbuf(db, fmt, ...)
406 #define dprintf_dbuf_bp(db, bp, fmt, ...)
407 #define DBUF_VERIFY(db)
416 #endif /* _SYS_DBUF_H */