/* * 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. * Copyright (c) 2012, 2015 by Delphix. All rights reserved. * Copyright (c) 2013 by Saso Kiselkov. All rights reserved. * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. */ #ifndef _SYS_DBUF_H #define _SYS_DBUF_H #include #include #include #include #include #include #include #include #include #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 -------+ * * DB_SEARCH is an invalid state for a dbuf. It is used by dbuf_free_range * to find all dbufs in a range of a dnode and must be less than any other * dbuf_states_t (see comment on dn_dbufs in dnode.h). */ typedef enum dbuf_states { DB_SEARCH = -1, 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; /* How much space was changed to dsl_pool_dirty_space() for this? */ unsigned int dr_accounted; /* A copy of the bp that points to us */ blkptr_t dr_bp_copy; 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; boolean_t dr_nopwrite; } 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. */ zfs_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. */ avl_node_t db_link; /* * Link in dbuf_cache. */ multilist_node_t db_cache_link; /* Data which is unique to data (leaf) blocks: */ /* User callback information. */ dmu_buf_user_t *db_user; /* * Evict user data as soon as the dirty and reference * counts are equal. */ uint8_t db_user_immediate_evict; /* * This block was freed while a read or write was * active. */ uint8_t db_freed_in_flight; /* * dnode_evict_dbufs() or dnode_evict_bonus() tried to * evict this dbuf, but couldn't due to outstanding * references. Evict once the refcount drops to 0. */ uint8_t db_pending_evict; uint8_t db_dirtycnt; } dmu_buf_impl_t; /* Note: the dbuf hash table is exposed only for the mdb module */ #define DBUF_MUTEXES 8192 #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(const struct dnode *di, const int64_t level, const uint64_t offset); 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_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, boolean_t fail_sparse, boolean_t fail_uncached, void *tag, dmu_buf_impl_t **dbp); void dbuf_prefetch(struct dnode *dn, int64_t level, uint64_t blkid, zio_priority_t prio, arc_flags_t aflags); void dbuf_add_ref(dmu_buf_impl_t *db, void *tag); boolean_t dbuf_try_add_ref(dmu_buf_t *db, objset_t *os, uint64_t obj, uint64_t blkid, 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 objset *os, uint64_t object, uint8_t level, uint64_t blkid); int dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags); 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 dmu_buf_write_embedded(dmu_buf_t *dbuf, void *data, bp_embedded_type_t etype, enum zio_compress comp, int uncompressed_size, int compressed_size, int byteorder, dmu_tx_t *tx); void dbuf_destroy(dmu_buf_impl_t *db); void dbuf_unoverride(dbuf_dirty_record_t *dr); void dbuf_sync_list(list_t *list, int level, 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); void dbuf_stats_init(dbuf_hash_table_t *hash); void dbuf_stats_destroy(void); #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))) void dbuf_init(void); void dbuf_fini(void); boolean_t dbuf_is_metadata(dmu_buf_impl_t *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))) #define DNODE_LEVEL_IS_L2CACHEABLE(_dn, _level) \ ((_dn)->dn_objset->os_secondary_cache == ZFS_CACHE_ALL || \ (((_level) > 0 || \ DMU_OT_IS_METADATA((_dn)->dn_handle->dnh_dnode->dn_type)) && \ ((_dn)->dn_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); \ snprintf_blkptr(__blkbuf, BP_SPRINTF_LEN, 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 */