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Diffstat (limited to 'include/sys/dbuf.h')
| -rw-r--r-- | include/sys/dbuf.h | 375 |
1 files changed, 375 insertions, 0 deletions
diff --git a/include/sys/dbuf.h b/include/sys/dbuf.h new file mode 100644 index 000000000..cf1bbc030 --- /dev/null +++ b/include/sys/dbuf.h @@ -0,0 +1,375 @@ +/* + * 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 http://www.opensolaris.org/os/licensing. + * 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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. + */ + +#ifndef _SYS_DBUF_H +#define _SYS_DBUF_H + +#include <sys/dmu.h> +#include <sys/spa.h> +#include <sys/txg.h> +#include <sys/zio.h> +#include <sys/arc.h> +#include <sys/zfs_context.h> +#include <sys/refcount.h> +#include <sys/zrlock.h> + +#ifdef __cplusplus +extern "C" { +#endif + +#define IN_DMU_SYNC 2 + +/* + * define flags for dbuf_read + */ + +#define DB_RF_MUST_SUCCEED (1 << 0) +#define DB_RF_CANFAIL (1 << 1) +#define DB_RF_HAVESTRUCT (1 << 2) +#define DB_RF_NOPREFETCH (1 << 3) +#define DB_RF_NEVERWAIT (1 << 4) +#define DB_RF_CACHED (1 << 5) + +/* + * The simplified state transition diagram for dbufs looks like: + * + * +----> READ ----+ + * | | + * | V + * (alloc)-->UNCACHED CACHED-->EVICTING-->(free) + * | ^ ^ + * | | | + * +----> FILL ----+ | + * | | + * | | + * +--------> NOFILL -------+ + */ +typedef enum dbuf_states { + DB_UNCACHED, + DB_FILL, + DB_NOFILL, + DB_READ, + DB_CACHED, + DB_EVICTING +} dbuf_states_t; + +struct dnode; +struct dmu_tx; + +/* + * level = 0 means the user data + * level = 1 means the single indirect block + * etc. + */ + +struct dmu_buf_impl; + +typedef enum override_states { + DR_NOT_OVERRIDDEN, + DR_IN_DMU_SYNC, + DR_OVERRIDDEN +} override_states_t; + +typedef struct dbuf_dirty_record { + /* link on our parents dirty list */ + list_node_t dr_dirty_node; + + /* transaction group this data will sync in */ + uint64_t dr_txg; + + /* zio of outstanding write IO */ + zio_t *dr_zio; + + /* pointer back to our dbuf */ + struct dmu_buf_impl *dr_dbuf; + + /* pointer to next dirty record */ + struct dbuf_dirty_record *dr_next; + + /* pointer to parent dirty record */ + struct dbuf_dirty_record *dr_parent; + + union dirty_types { + struct dirty_indirect { + + /* protect access to list */ + kmutex_t dr_mtx; + + /* Our list of dirty children */ + list_t dr_children; + } di; + struct dirty_leaf { + + /* + * dr_data is set when we dirty the buffer + * so that we can retain the pointer even if it + * gets COW'd in a subsequent transaction group. + */ + arc_buf_t *dr_data; + blkptr_t dr_overridden_by; + override_states_t dr_override_state; + uint8_t dr_copies; + } dl; + } dt; +} dbuf_dirty_record_t; + +typedef struct dmu_buf_impl { + /* + * The following members are immutable, with the exception of + * db.db_data, which is protected by db_mtx. + */ + + /* the publicly visible structure */ + dmu_buf_t db; + + /* the objset we belong to */ + struct objset *db_objset; + + /* + * handle to safely access the dnode we belong to (NULL when evicted) + */ + struct dnode_handle *db_dnode_handle; + + /* + * our parent buffer; if the dnode points to us directly, + * db_parent == db_dnode_handle->dnh_dnode->dn_dbuf + * only accessed by sync thread ??? + * (NULL when evicted) + * May change from NULL to non-NULL under the protection of db_mtx + * (see dbuf_check_blkptr()) + */ + struct dmu_buf_impl *db_parent; + + /* + * link for hash table of all dmu_buf_impl_t's + */ + struct dmu_buf_impl *db_hash_next; + + /* our block number */ + uint64_t db_blkid; + + /* + * Pointer to the blkptr_t which points to us. May be NULL if we + * don't have one yet. (NULL when evicted) + */ + blkptr_t *db_blkptr; + + /* + * Our indirection level. Data buffers have db_level==0. + * Indirect buffers which point to data buffers have + * db_level==1. etc. Buffers which contain dnodes have + * db_level==0, since the dnodes are stored in a file. + */ + uint8_t db_level; + + /* db_mtx protects the members below */ + kmutex_t db_mtx; + + /* + * Current state of the buffer + */ + dbuf_states_t db_state; + + /* + * Refcount accessed by dmu_buf_{hold,rele}. + * If nonzero, the buffer can't be destroyed. + * Protected by db_mtx. + */ + refcount_t db_holds; + + /* buffer holding our data */ + arc_buf_t *db_buf; + + kcondvar_t db_changed; + dbuf_dirty_record_t *db_data_pending; + + /* pointer to most recent dirty record for this buffer */ + dbuf_dirty_record_t *db_last_dirty; + + /* + * Our link on the owner dnodes's dn_dbufs list. + * Protected by its dn_dbufs_mtx. + */ + list_node_t db_link; + + /* Data which is unique to data (leaf) blocks: */ + + /* stuff we store for the user (see dmu_buf_set_user) */ + void *db_user_ptr; + void **db_user_data_ptr_ptr; + dmu_buf_evict_func_t *db_evict_func; + + uint8_t db_immediate_evict; + uint8_t db_freed_in_flight; + + uint8_t db_dirtycnt; +} dmu_buf_impl_t; + +/* Note: the dbuf hash table is exposed only for the mdb module */ +#define DBUF_MUTEXES 256 +#define DBUF_HASH_MUTEX(h, idx) (&(h)->hash_mutexes[(idx) & (DBUF_MUTEXES-1)]) +typedef struct dbuf_hash_table { + uint64_t hash_table_mask; + dmu_buf_impl_t **hash_table; + kmutex_t hash_mutexes[DBUF_MUTEXES]; +} dbuf_hash_table_t; + + +uint64_t dbuf_whichblock(struct dnode *di, uint64_t offset); + +dmu_buf_impl_t *dbuf_create_tlib(struct dnode *dn, char *data); +void dbuf_create_bonus(struct dnode *dn); +int dbuf_spill_set_blksz(dmu_buf_t *db, uint64_t blksz, dmu_tx_t *tx); +void dbuf_spill_hold(struct dnode *dn, dmu_buf_impl_t **dbp, void *tag); + +void dbuf_rm_spill(struct dnode *dn, dmu_tx_t *tx); + +dmu_buf_impl_t *dbuf_hold(struct dnode *dn, uint64_t blkid, void *tag); +dmu_buf_impl_t *dbuf_hold_level(struct dnode *dn, int level, uint64_t blkid, + void *tag); +int dbuf_hold_impl(struct dnode *dn, uint8_t level, uint64_t blkid, int create, + void *tag, dmu_buf_impl_t **dbp); + +void dbuf_prefetch(struct dnode *dn, uint64_t blkid); + +void dbuf_add_ref(dmu_buf_impl_t *db, void *tag); +uint64_t dbuf_refcount(dmu_buf_impl_t *db); + +void dbuf_rele(dmu_buf_impl_t *db, void *tag); +void dbuf_rele_and_unlock(dmu_buf_impl_t *db, void *tag); + +dmu_buf_impl_t *dbuf_find(struct dnode *dn, uint8_t level, uint64_t blkid); + +int dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags); +void dbuf_will_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx); +void dbuf_fill_done(dmu_buf_impl_t *db, dmu_tx_t *tx); +void dmu_buf_will_not_fill(dmu_buf_t *db, dmu_tx_t *tx); +void dmu_buf_will_fill(dmu_buf_t *db, dmu_tx_t *tx); +void dmu_buf_fill_done(dmu_buf_t *db, dmu_tx_t *tx); +void dbuf_assign_arcbuf(dmu_buf_impl_t *db, arc_buf_t *buf, dmu_tx_t *tx); +dbuf_dirty_record_t *dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx); +arc_buf_t *dbuf_loan_arcbuf(dmu_buf_impl_t *db); + +void dbuf_clear(dmu_buf_impl_t *db); +void dbuf_evict(dmu_buf_impl_t *db); + +void dbuf_setdirty(dmu_buf_impl_t *db, dmu_tx_t *tx); +void dbuf_unoverride(dbuf_dirty_record_t *dr); +void dbuf_sync_list(list_t *list, dmu_tx_t *tx); +void dbuf_release_bp(dmu_buf_impl_t *db); + +void dbuf_free_range(struct dnode *dn, uint64_t start, uint64_t end, + struct dmu_tx *); + +void dbuf_new_size(dmu_buf_impl_t *db, int size, dmu_tx_t *tx); + +#define DB_DNODE(_db) ((_db)->db_dnode_handle->dnh_dnode) +#define DB_DNODE_LOCK(_db) ((_db)->db_dnode_handle->dnh_zrlock) +#define DB_DNODE_ENTER(_db) (zrl_add(&DB_DNODE_LOCK(_db))) +#define DB_DNODE_EXIT(_db) (zrl_remove(&DB_DNODE_LOCK(_db))) +#define DB_DNODE_HELD(_db) (!zrl_is_zero(&DB_DNODE_LOCK(_db))) +#define DB_GET_SPA(_spa_p, _db) { \ + dnode_t *__dn; \ + DB_DNODE_ENTER(_db); \ + __dn = DB_DNODE(_db); \ + *(_spa_p) = __dn->dn_objset->os_spa; \ + DB_DNODE_EXIT(_db); \ +} +#define DB_GET_OBJSET(_os_p, _db) { \ + dnode_t *__dn; \ + DB_DNODE_ENTER(_db); \ + __dn = DB_DNODE(_db); \ + *(_os_p) = __dn->dn_objset; \ + DB_DNODE_EXIT(_db); \ +} + +void dbuf_init(void); +void dbuf_fini(void); + +boolean_t dbuf_is_metadata(dmu_buf_impl_t *db); + +#define DBUF_IS_METADATA(_db) \ + (dbuf_is_metadata(_db)) + +#define DBUF_GET_BUFC_TYPE(_db) \ + (DBUF_IS_METADATA(_db) ? ARC_BUFC_METADATA : ARC_BUFC_DATA) + +#define DBUF_IS_CACHEABLE(_db) \ + ((_db)->db_objset->os_primary_cache == ZFS_CACHE_ALL || \ + (DBUF_IS_METADATA(_db) && \ + ((_db)->db_objset->os_primary_cache == ZFS_CACHE_METADATA))) + +#define DBUF_IS_L2CACHEABLE(_db) \ + ((_db)->db_objset->os_secondary_cache == ZFS_CACHE_ALL || \ + (DBUF_IS_METADATA(_db) && \ + ((_db)->db_objset->os_secondary_cache == ZFS_CACHE_METADATA))) + +#ifdef ZFS_DEBUG + +/* + * There should be a ## between the string literal and fmt, to make it + * clear that we're joining two strings together, but gcc does not + * support that preprocessor token. + */ +#define dprintf_dbuf(dbuf, fmt, ...) do { \ + if (zfs_flags & ZFS_DEBUG_DPRINTF) { \ + char __db_buf[32]; \ + uint64_t __db_obj = (dbuf)->db.db_object; \ + if (__db_obj == DMU_META_DNODE_OBJECT) \ + (void) strcpy(__db_buf, "mdn"); \ + else \ + (void) snprintf(__db_buf, sizeof (__db_buf), "%lld", \ + (u_longlong_t)__db_obj); \ + dprintf_ds((dbuf)->db_objset->os_dsl_dataset, \ + "obj=%s lvl=%u blkid=%lld " fmt, \ + __db_buf, (dbuf)->db_level, \ + (u_longlong_t)(dbuf)->db_blkid, __VA_ARGS__); \ + } \ +_NOTE(CONSTCOND) } while (0) + +#define dprintf_dbuf_bp(db, bp, fmt, ...) do { \ + if (zfs_flags & ZFS_DEBUG_DPRINTF) { \ + char *__blkbuf = kmem_alloc(BP_SPRINTF_LEN, KM_SLEEP); \ + sprintf_blkptr(__blkbuf, bp); \ + dprintf_dbuf(db, fmt " %s\n", __VA_ARGS__, __blkbuf); \ + kmem_free(__blkbuf, BP_SPRINTF_LEN); \ + } \ +_NOTE(CONSTCOND) } while (0) + +#define DBUF_VERIFY(db) dbuf_verify(db) + +#else + +#define dprintf_dbuf(db, fmt, ...) +#define dprintf_dbuf_bp(db, bp, fmt, ...) +#define DBUF_VERIFY(db) + +#endif + + +#ifdef __cplusplus +} +#endif + +#endif /* _SYS_DBUF_H */ |