| /* |
| * 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 2011 Nexenta Systems, Inc. All rights reserved. |
| * Copyright (c) 2012, 2018 by Delphix. All rights reserved. |
| * Copyright (c) 2013 by Saso Kiselkov. All rights reserved. |
| * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. |
| */ |
| |
| #include <sys/zfs_context.h> |
| #include <sys/arc.h> |
| #include <sys/dmu.h> |
| #include <sys/dmu_send.h> |
| #include <sys/dmu_impl.h> |
| #include <sys/dbuf.h> |
| #include <sys/dmu_objset.h> |
| #include <sys/dsl_dataset.h> |
| #include <sys/dsl_dir.h> |
| #include <sys/dmu_tx.h> |
| #include <sys/spa.h> |
| #include <sys/zio.h> |
| #include <sys/dmu_zfetch.h> |
| #include <sys/sa.h> |
| #include <sys/sa_impl.h> |
| #include <sys/zfeature.h> |
| #include <sys/blkptr.h> |
| #include <sys/range_tree.h> |
| #include <sys/trace_dbuf.h> |
| #include <sys/callb.h> |
| #include <sys/abd.h> |
| #include <sys/vdev.h> |
| #include <sys/cityhash.h> |
| #include <sys/spa_impl.h> |
| |
| kstat_t *dbuf_ksp; |
| |
| typedef struct dbuf_stats { |
| /* |
| * Various statistics about the size of the dbuf cache. |
| */ |
| kstat_named_t cache_count; |
| kstat_named_t cache_size_bytes; |
| kstat_named_t cache_size_bytes_max; |
| /* |
| * Statistics regarding the bounds on the dbuf cache size. |
| */ |
| kstat_named_t cache_target_bytes; |
| kstat_named_t cache_lowater_bytes; |
| kstat_named_t cache_hiwater_bytes; |
| /* |
| * Total number of dbuf cache evictions that have occurred. |
| */ |
| kstat_named_t cache_total_evicts; |
| /* |
| * The distribution of dbuf levels in the dbuf cache and |
| * the total size of all dbufs at each level. |
| */ |
| kstat_named_t cache_levels[DN_MAX_LEVELS]; |
| kstat_named_t cache_levels_bytes[DN_MAX_LEVELS]; |
| /* |
| * Statistics about the dbuf hash table. |
| */ |
| kstat_named_t hash_hits; |
| kstat_named_t hash_misses; |
| kstat_named_t hash_collisions; |
| kstat_named_t hash_elements; |
| kstat_named_t hash_elements_max; |
| /* |
| * Number of sublists containing more than one dbuf in the dbuf |
| * hash table. Keep track of the longest hash chain. |
| */ |
| kstat_named_t hash_chains; |
| kstat_named_t hash_chain_max; |
| /* |
| * Number of times a dbuf_create() discovers that a dbuf was |
| * already created and in the dbuf hash table. |
| */ |
| kstat_named_t hash_insert_race; |
| /* |
| * Statistics about the size of the metadata dbuf cache. |
| */ |
| kstat_named_t metadata_cache_count; |
| kstat_named_t metadata_cache_size_bytes; |
| kstat_named_t metadata_cache_size_bytes_max; |
| /* |
| * For diagnostic purposes, this is incremented whenever we can't add |
| * something to the metadata cache because it's full, and instead put |
| * the data in the regular dbuf cache. |
| */ |
| kstat_named_t metadata_cache_overflow; |
| } dbuf_stats_t; |
| |
| dbuf_stats_t dbuf_stats = { |
| { "cache_count", KSTAT_DATA_UINT64 }, |
| { "cache_size_bytes", KSTAT_DATA_UINT64 }, |
| { "cache_size_bytes_max", KSTAT_DATA_UINT64 }, |
| { "cache_target_bytes", KSTAT_DATA_UINT64 }, |
| { "cache_lowater_bytes", KSTAT_DATA_UINT64 }, |
| { "cache_hiwater_bytes", KSTAT_DATA_UINT64 }, |
| { "cache_total_evicts", KSTAT_DATA_UINT64 }, |
| { { "cache_levels_N", KSTAT_DATA_UINT64 } }, |
| { { "cache_levels_bytes_N", KSTAT_DATA_UINT64 } }, |
| { "hash_hits", KSTAT_DATA_UINT64 }, |
| { "hash_misses", KSTAT_DATA_UINT64 }, |
| { "hash_collisions", KSTAT_DATA_UINT64 }, |
| { "hash_elements", KSTAT_DATA_UINT64 }, |
| { "hash_elements_max", KSTAT_DATA_UINT64 }, |
| { "hash_chains", KSTAT_DATA_UINT64 }, |
| { "hash_chain_max", KSTAT_DATA_UINT64 }, |
| { "hash_insert_race", KSTAT_DATA_UINT64 }, |
| { "metadata_cache_count", KSTAT_DATA_UINT64 }, |
| { "metadata_cache_size_bytes", KSTAT_DATA_UINT64 }, |
| { "metadata_cache_size_bytes_max", KSTAT_DATA_UINT64 }, |
| { "metadata_cache_overflow", KSTAT_DATA_UINT64 } |
| }; |
| |
| #define DBUF_STAT_INCR(stat, val) \ |
| atomic_add_64(&dbuf_stats.stat.value.ui64, (val)); |
| #define DBUF_STAT_DECR(stat, val) \ |
| DBUF_STAT_INCR(stat, -(val)); |
| #define DBUF_STAT_BUMP(stat) \ |
| DBUF_STAT_INCR(stat, 1); |
| #define DBUF_STAT_BUMPDOWN(stat) \ |
| DBUF_STAT_INCR(stat, -1); |
| #define DBUF_STAT_MAX(stat, v) { \ |
| uint64_t _m; \ |
| while ((v) > (_m = dbuf_stats.stat.value.ui64) && \ |
| (_m != atomic_cas_64(&dbuf_stats.stat.value.ui64, _m, (v))))\ |
| continue; \ |
| } |
| |
| typedef struct dbuf_hold_arg { |
| /* Function arguments */ |
| dnode_t *dh_dn; |
| uint8_t dh_level; |
| uint64_t dh_blkid; |
| boolean_t dh_fail_sparse; |
| boolean_t dh_fail_uncached; |
| void *dh_tag; |
| dmu_buf_impl_t **dh_dbp; |
| /* Local variables */ |
| dmu_buf_impl_t *dh_db; |
| dmu_buf_impl_t *dh_parent; |
| blkptr_t *dh_bp; |
| int dh_err; |
| dbuf_dirty_record_t *dh_dr; |
| } dbuf_hold_arg_t; |
| |
| static dbuf_hold_arg_t *dbuf_hold_arg_create(dnode_t *dn, uint8_t level, |
| uint64_t blkid, boolean_t fail_sparse, boolean_t fail_uncached, |
| void *tag, dmu_buf_impl_t **dbp); |
| static int dbuf_hold_impl_arg(dbuf_hold_arg_t *dh); |
| static void dbuf_hold_arg_destroy(dbuf_hold_arg_t *dh); |
| |
| static boolean_t dbuf_undirty(dmu_buf_impl_t *db, dmu_tx_t *tx); |
| static void dbuf_write(dbuf_dirty_record_t *dr, arc_buf_t *data, dmu_tx_t *tx); |
| |
| extern inline void dmu_buf_init_user(dmu_buf_user_t *dbu, |
| dmu_buf_evict_func_t *evict_func_sync, |
| dmu_buf_evict_func_t *evict_func_async, |
| dmu_buf_t **clear_on_evict_dbufp); |
| |
| /* |
| * Global data structures and functions for the dbuf cache. |
| */ |
| static kmem_cache_t *dbuf_kmem_cache; |
| static taskq_t *dbu_evict_taskq; |
| |
| static kthread_t *dbuf_cache_evict_thread; |
| static kmutex_t dbuf_evict_lock; |
| static kcondvar_t dbuf_evict_cv; |
| static boolean_t dbuf_evict_thread_exit; |
| |
| /* |
| * There are two dbuf caches; each dbuf can only be in one of them at a time. |
| * |
| * 1. Cache of metadata dbufs, to help make read-heavy administrative commands |
| * from /sbin/zfs run faster. The "metadata cache" specifically stores dbufs |
| * that represent the metadata that describes filesystems/snapshots/ |
| * bookmarks/properties/etc. We only evict from this cache when we export a |
| * pool, to short-circuit as much I/O as possible for all administrative |
| * commands that need the metadata. There is no eviction policy for this |
| * cache, because we try to only include types in it which would occupy a |
| * very small amount of space per object but create a large impact on the |
| * performance of these commands. Instead, after it reaches a maximum size |
| * (which should only happen on very small memory systems with a very large |
| * number of filesystem objects), we stop taking new dbufs into the |
| * metadata cache, instead putting them in the normal dbuf cache. |
| * |
| * 2. LRU cache of dbufs. The dbuf cache maintains a list of dbufs that |
| * are not currently held but have been recently released. These dbufs |
| * are not eligible for arc eviction until they are aged out of the cache. |
| * Dbufs that are aged out of the cache will be immediately destroyed and |
| * become eligible for arc eviction. |
| * |
| * Dbufs are added to these caches once the last hold is released. If a dbuf is |
| * later accessed and still exists in the dbuf cache, then it will be removed |
| * from the cache and later re-added to the head of the cache. |
| * |
| * If a given dbuf meets the requirements for the metadata cache, it will go |
| * there, otherwise it will be considered for the generic LRU dbuf cache. The |
| * caches and the refcounts tracking their sizes are stored in an array indexed |
| * by those caches' matching enum values (from dbuf_cached_state_t). |
| */ |
| typedef struct dbuf_cache { |
| multilist_t *cache; |
| zfs_refcount_t size; |
| } dbuf_cache_t; |
| dbuf_cache_t dbuf_caches[DB_CACHE_MAX]; |
| |
| /* Size limits for the caches */ |
| unsigned long dbuf_cache_max_bytes = 0; |
| unsigned long dbuf_metadata_cache_max_bytes = 0; |
| /* Set the default sizes of the caches to log2 fraction of arc size */ |
| int dbuf_cache_shift = 5; |
| int dbuf_metadata_cache_shift = 6; |
| |
| /* |
| * The LRU dbuf cache uses a three-stage eviction policy: |
| * - A low water marker designates when the dbuf eviction thread |
| * should stop evicting from the dbuf cache. |
| * - When we reach the maximum size (aka mid water mark), we |
| * signal the eviction thread to run. |
| * - The high water mark indicates when the eviction thread |
| * is unable to keep up with the incoming load and eviction must |
| * happen in the context of the calling thread. |
| * |
| * The dbuf cache: |
| * (max size) |
| * low water mid water hi water |
| * +----------------------------------------+----------+----------+ |
| * | | | | |
| * | | | | |
| * | | | | |
| * | | | | |
| * +----------------------------------------+----------+----------+ |
| * stop signal evict |
| * evicting eviction directly |
| * thread |
| * |
| * The high and low water marks indicate the operating range for the eviction |
| * thread. The low water mark is, by default, 90% of the total size of the |
| * cache and the high water mark is at 110% (both of these percentages can be |
| * changed by setting dbuf_cache_lowater_pct and dbuf_cache_hiwater_pct, |
| * respectively). The eviction thread will try to ensure that the cache remains |
| * within this range by waking up every second and checking if the cache is |
| * above the low water mark. The thread can also be woken up by callers adding |
| * elements into the cache if the cache is larger than the mid water (i.e max |
| * cache size). Once the eviction thread is woken up and eviction is required, |
| * it will continue evicting buffers until it's able to reduce the cache size |
| * to the low water mark. If the cache size continues to grow and hits the high |
| * water mark, then callers adding elements to the cache will begin to evict |
| * directly from the cache until the cache is no longer above the high water |
| * mark. |
| */ |
| |
| /* |
| * The percentage above and below the maximum cache size. |
| */ |
| uint_t dbuf_cache_hiwater_pct = 10; |
| uint_t dbuf_cache_lowater_pct = 10; |
| |
| /* ARGSUSED */ |
| static int |
| dbuf_cons(void *vdb, void *unused, int kmflag) |
| { |
| dmu_buf_impl_t *db = vdb; |
| bzero(db, sizeof (dmu_buf_impl_t)); |
| |
| mutex_init(&db->db_mtx, NULL, MUTEX_DEFAULT, NULL); |
| cv_init(&db->db_changed, NULL, CV_DEFAULT, NULL); |
| multilist_link_init(&db->db_cache_link); |
| zfs_refcount_create(&db->db_holds); |
| |
| return (0); |
| } |
| |
| /* ARGSUSED */ |
| static void |
| dbuf_dest(void *vdb, void *unused) |
| { |
| dmu_buf_impl_t *db = vdb; |
| mutex_destroy(&db->db_mtx); |
| cv_destroy(&db->db_changed); |
| ASSERT(!multilist_link_active(&db->db_cache_link)); |
| zfs_refcount_destroy(&db->db_holds); |
| } |
| |
| /* |
| * dbuf hash table routines |
| */ |
| static dbuf_hash_table_t dbuf_hash_table; |
| |
| static uint64_t dbuf_hash_count; |
| |
| /* |
| * We use Cityhash for this. It's fast, and has good hash properties without |
| * requiring any large static buffers. |
| */ |
| static uint64_t |
| dbuf_hash(void *os, uint64_t obj, uint8_t lvl, uint64_t blkid) |
| { |
| return (cityhash4((uintptr_t)os, obj, (uint64_t)lvl, blkid)); |
| } |
| |
| #define DBUF_EQUAL(dbuf, os, obj, level, blkid) \ |
| ((dbuf)->db.db_object == (obj) && \ |
| (dbuf)->db_objset == (os) && \ |
| (dbuf)->db_level == (level) && \ |
| (dbuf)->db_blkid == (blkid)) |
| |
| dmu_buf_impl_t * |
| dbuf_find(objset_t *os, uint64_t obj, uint8_t level, uint64_t blkid) |
| { |
| dbuf_hash_table_t *h = &dbuf_hash_table; |
| uint64_t hv; |
| uint64_t idx; |
| dmu_buf_impl_t *db; |
| |
| hv = dbuf_hash(os, obj, level, blkid); |
| idx = hv & h->hash_table_mask; |
| |
| mutex_enter(DBUF_HASH_MUTEX(h, idx)); |
| for (db = h->hash_table[idx]; db != NULL; db = db->db_hash_next) { |
| if (DBUF_EQUAL(db, os, obj, level, blkid)) { |
| mutex_enter(&db->db_mtx); |
| if (db->db_state != DB_EVICTING) { |
| mutex_exit(DBUF_HASH_MUTEX(h, idx)); |
| return (db); |
| } |
| mutex_exit(&db->db_mtx); |
| } |
| } |
| mutex_exit(DBUF_HASH_MUTEX(h, idx)); |
| return (NULL); |
| } |
| |
| static dmu_buf_impl_t * |
| dbuf_find_bonus(objset_t *os, uint64_t object) |
| { |
| dnode_t *dn; |
| dmu_buf_impl_t *db = NULL; |
| |
| if (dnode_hold(os, object, FTAG, &dn) == 0) { |
| rw_enter(&dn->dn_struct_rwlock, RW_READER); |
| if (dn->dn_bonus != NULL) { |
| db = dn->dn_bonus; |
| mutex_enter(&db->db_mtx); |
| } |
| rw_exit(&dn->dn_struct_rwlock); |
| dnode_rele(dn, FTAG); |
| } |
| return (db); |
| } |
| |
| /* |
| * Insert an entry into the hash table. If there is already an element |
| * equal to elem in the hash table, then the already existing element |
| * will be returned and the new element will not be inserted. |
| * Otherwise returns NULL. |
| */ |
| static dmu_buf_impl_t * |
| dbuf_hash_insert(dmu_buf_impl_t *db) |
| { |
| dbuf_hash_table_t *h = &dbuf_hash_table; |
| objset_t *os = db->db_objset; |
| uint64_t obj = db->db.db_object; |
| int level = db->db_level; |
| uint64_t blkid, hv, idx; |
| dmu_buf_impl_t *dbf; |
| uint32_t i; |
| |
| blkid = db->db_blkid; |
| hv = dbuf_hash(os, obj, level, blkid); |
| idx = hv & h->hash_table_mask; |
| |
| mutex_enter(DBUF_HASH_MUTEX(h, idx)); |
| for (dbf = h->hash_table[idx], i = 0; dbf != NULL; |
| dbf = dbf->db_hash_next, i++) { |
| if (DBUF_EQUAL(dbf, os, obj, level, blkid)) { |
| mutex_enter(&dbf->db_mtx); |
| if (dbf->db_state != DB_EVICTING) { |
| mutex_exit(DBUF_HASH_MUTEX(h, idx)); |
| return (dbf); |
| } |
| mutex_exit(&dbf->db_mtx); |
| } |
| } |
| |
| if (i > 0) { |
| DBUF_STAT_BUMP(hash_collisions); |
| if (i == 1) |
| DBUF_STAT_BUMP(hash_chains); |
| |
| DBUF_STAT_MAX(hash_chain_max, i); |
| } |
| |
| mutex_enter(&db->db_mtx); |
| db->db_hash_next = h->hash_table[idx]; |
| h->hash_table[idx] = db; |
| mutex_exit(DBUF_HASH_MUTEX(h, idx)); |
| atomic_inc_64(&dbuf_hash_count); |
| DBUF_STAT_MAX(hash_elements_max, dbuf_hash_count); |
| |
| return (NULL); |
| } |
| |
| /* |
| * This returns whether this dbuf should be stored in the metadata cache, which |
| * is based on whether it's from one of the dnode types that store data related |
| * to traversing dataset hierarchies. |
| */ |
| static boolean_t |
| dbuf_include_in_metadata_cache(dmu_buf_impl_t *db) |
| { |
| DB_DNODE_ENTER(db); |
| dmu_object_type_t type = DB_DNODE(db)->dn_type; |
| DB_DNODE_EXIT(db); |
| |
| /* Check if this dbuf is one of the types we care about */ |
| if (DMU_OT_IS_METADATA_CACHED(type)) { |
| /* If we hit this, then we set something up wrong in dmu_ot */ |
| ASSERT(DMU_OT_IS_METADATA(type)); |
| |
| /* |
| * Sanity check for small-memory systems: don't allocate too |
| * much memory for this purpose. |
| */ |
| if (zfs_refcount_count( |
| &dbuf_caches[DB_DBUF_METADATA_CACHE].size) > |
| dbuf_metadata_cache_max_bytes) { |
| DBUF_STAT_BUMP(metadata_cache_overflow); |
| return (B_FALSE); |
| } |
| |
| return (B_TRUE); |
| } |
| |
| return (B_FALSE); |
| } |
| |
| /* |
| * Remove an entry from the hash table. It must be in the EVICTING state. |
| */ |
| static void |
| dbuf_hash_remove(dmu_buf_impl_t *db) |
| { |
| dbuf_hash_table_t *h = &dbuf_hash_table; |
| uint64_t hv, idx; |
| dmu_buf_impl_t *dbf, **dbp; |
| |
| hv = dbuf_hash(db->db_objset, db->db.db_object, |
| db->db_level, db->db_blkid); |
| idx = hv & h->hash_table_mask; |
| |
| /* |
| * We mustn't hold db_mtx to maintain lock ordering: |
| * DBUF_HASH_MUTEX > db_mtx. |
| */ |
| ASSERT(zfs_refcount_is_zero(&db->db_holds)); |
| ASSERT(db->db_state == DB_EVICTING); |
| ASSERT(!MUTEX_HELD(&db->db_mtx)); |
| |
| mutex_enter(DBUF_HASH_MUTEX(h, idx)); |
| dbp = &h->hash_table[idx]; |
| while ((dbf = *dbp) != db) { |
| dbp = &dbf->db_hash_next; |
| ASSERT(dbf != NULL); |
| } |
| *dbp = db->db_hash_next; |
| db->db_hash_next = NULL; |
| if (h->hash_table[idx] && |
| h->hash_table[idx]->db_hash_next == NULL) |
| DBUF_STAT_BUMPDOWN(hash_chains); |
| mutex_exit(DBUF_HASH_MUTEX(h, idx)); |
| atomic_dec_64(&dbuf_hash_count); |
| } |
| |
| typedef enum { |
| DBVU_EVICTING, |
| DBVU_NOT_EVICTING |
| } dbvu_verify_type_t; |
| |
| static void |
| dbuf_verify_user(dmu_buf_impl_t *db, dbvu_verify_type_t verify_type) |
| { |
| #ifdef ZFS_DEBUG |
| int64_t holds; |
| |
| if (db->db_user == NULL) |
| return; |
| |
| /* Only data blocks support the attachment of user data. */ |
| ASSERT(db->db_level == 0); |
| |
| /* Clients must resolve a dbuf before attaching user data. */ |
| ASSERT(db->db.db_data != NULL); |
| ASSERT3U(db->db_state, ==, DB_CACHED); |
| |
| holds = zfs_refcount_count(&db->db_holds); |
| if (verify_type == DBVU_EVICTING) { |
| /* |
| * Immediate eviction occurs when holds == dirtycnt. |
| * For normal eviction buffers, holds is zero on |
| * eviction, except when dbuf_fix_old_data() calls |
| * dbuf_clear_data(). However, the hold count can grow |
| * during eviction even though db_mtx is held (see |
| * dmu_bonus_hold() for an example), so we can only |
| * test the generic invariant that holds >= dirtycnt. |
| */ |
| ASSERT3U(holds, >=, db->db_dirtycnt); |
| } else { |
| if (db->db_user_immediate_evict == TRUE) |
| ASSERT3U(holds, >=, db->db_dirtycnt); |
| else |
| ASSERT3U(holds, >, 0); |
| } |
| #endif |
| } |
| |
| static void |
| dbuf_evict_user(dmu_buf_impl_t *db) |
| { |
| dmu_buf_user_t *dbu = db->db_user; |
| |
| ASSERT(MUTEX_HELD(&db->db_mtx)); |
| |
| if (dbu == NULL) |
| return; |
| |
| dbuf_verify_user(db, DBVU_EVICTING); |
| db->db_user = NULL; |
| |
| #ifdef ZFS_DEBUG |
| if (dbu->dbu_clear_on_evict_dbufp != NULL) |
| *dbu->dbu_clear_on_evict_dbufp = NULL; |
| #endif |
| |
| /* |
| * There are two eviction callbacks - one that we call synchronously |
| * and one that we invoke via a taskq. The async one is useful for |
| * avoiding lock order reversals and limiting stack depth. |
| * |
| * Note that if we have a sync callback but no async callback, |
| * it's likely that the sync callback will free the structure |
| * containing the dbu. In that case we need to take care to not |
| * dereference dbu after calling the sync evict func. |
| */ |
| boolean_t has_async = (dbu->dbu_evict_func_async != NULL); |
| |
| if (dbu->dbu_evict_func_sync != NULL) |
| dbu->dbu_evict_func_sync(dbu); |
| |
| if (has_async) { |
| taskq_dispatch_ent(dbu_evict_taskq, dbu->dbu_evict_func_async, |
| dbu, 0, &dbu->dbu_tqent); |
| } |
| } |
| |
| boolean_t |
| dbuf_is_metadata(dmu_buf_impl_t *db) |
| { |
| /* |
| * Consider indirect blocks and spill blocks to be meta data. |
| */ |
| if (db->db_level > 0 || db->db_blkid == DMU_SPILL_BLKID) { |
| return (B_TRUE); |
| } else { |
| boolean_t is_metadata; |
| |
| DB_DNODE_ENTER(db); |
| is_metadata = DMU_OT_IS_METADATA(DB_DNODE(db)->dn_type); |
| DB_DNODE_EXIT(db); |
| |
| return (is_metadata); |
| } |
| } |
| |
| |
| /* |
| * This function *must* return indices evenly distributed between all |
| * sublists of the multilist. This is needed due to how the dbuf eviction |
| * code is laid out; dbuf_evict_thread() assumes dbufs are evenly |
| * distributed between all sublists and uses this assumption when |
| * deciding which sublist to evict from and how much to evict from it. |
| */ |
| unsigned int |
| dbuf_cache_multilist_index_func(multilist_t *ml, void *obj) |
| { |
| dmu_buf_impl_t *db = obj; |
| |
| /* |
| * The assumption here, is the hash value for a given |
| * dmu_buf_impl_t will remain constant throughout it's lifetime |
| * (i.e. it's objset, object, level and blkid fields don't change). |
| * Thus, we don't need to store the dbuf's sublist index |
| * on insertion, as this index can be recalculated on removal. |
| * |
| * Also, the low order bits of the hash value are thought to be |
| * distributed evenly. Otherwise, in the case that the multilist |
| * has a power of two number of sublists, each sublists' usage |
| * would not be evenly distributed. |
| */ |
| return (dbuf_hash(db->db_objset, db->db.db_object, |
| db->db_level, db->db_blkid) % |
| multilist_get_num_sublists(ml)); |
| } |
| |
| static inline unsigned long |
| dbuf_cache_target_bytes(void) |
| { |
| return MIN(dbuf_cache_max_bytes, |
| arc_target_bytes() >> dbuf_cache_shift); |
| } |
| |
| static inline uint64_t |
| dbuf_cache_hiwater_bytes(void) |
| { |
| uint64_t dbuf_cache_target = dbuf_cache_target_bytes(); |
| return (dbuf_cache_target + |
| (dbuf_cache_target * dbuf_cache_hiwater_pct) / 100); |
| } |
| |
| static inline uint64_t |
| dbuf_cache_lowater_bytes(void) |
| { |
| uint64_t dbuf_cache_target = dbuf_cache_target_bytes(); |
| return (dbuf_cache_target - |
| (dbuf_cache_target * dbuf_cache_lowater_pct) / 100); |
| } |
| |
| static inline boolean_t |
| dbuf_cache_above_hiwater(void) |
| { |
| return (zfs_refcount_count(&dbuf_caches[DB_DBUF_CACHE].size) > |
| dbuf_cache_hiwater_bytes()); |
| } |
| |
| static inline boolean_t |
| dbuf_cache_above_lowater(void) |
| { |
| return (zfs_refcount_count(&dbuf_caches[DB_DBUF_CACHE].size) > |
| dbuf_cache_lowater_bytes()); |
| } |
| |
| /* |
| * Evict the oldest eligible dbuf from the dbuf cache. |
| */ |
| static void |
| dbuf_evict_one(void) |
| { |
| int idx = multilist_get_random_index(dbuf_caches[DB_DBUF_CACHE].cache); |
| multilist_sublist_t *mls = multilist_sublist_lock( |
| dbuf_caches[DB_DBUF_CACHE].cache, idx); |
| |
| ASSERT(!MUTEX_HELD(&dbuf_evict_lock)); |
| |
| dmu_buf_impl_t *db = multilist_sublist_tail(mls); |
| while (db != NULL && mutex_tryenter(&db->db_mtx) == 0) { |
| db = multilist_sublist_prev(mls, db); |
| } |
| |
| DTRACE_PROBE2(dbuf__evict__one, dmu_buf_impl_t *, db, |
| multilist_sublist_t *, mls); |
| |
| if (db != NULL) { |
| multilist_sublist_remove(mls, db); |
| multilist_sublist_unlock(mls); |
| (void) zfs_refcount_remove_many( |
| &dbuf_caches[DB_DBUF_CACHE].size, db->db.db_size, db); |
| DBUF_STAT_BUMPDOWN(cache_levels[db->db_level]); |
| DBUF_STAT_BUMPDOWN(cache_count); |
| DBUF_STAT_DECR(cache_levels_bytes[db->db_level], |
| db->db.db_size); |
| ASSERT3U(db->db_caching_status, ==, DB_DBUF_CACHE); |
| db->db_caching_status = DB_NO_CACHE; |
| dbuf_destroy(db); |
| DBUF_STAT_MAX(cache_size_bytes_max, |
| zfs_refcount_count(&dbuf_caches[DB_DBUF_CACHE].size)); |
| DBUF_STAT_BUMP(cache_total_evicts); |
| } else { |
| multilist_sublist_unlock(mls); |
| } |
| } |
| |
| /* |
| * The dbuf evict thread is responsible for aging out dbufs from the |
| * cache. Once the cache has reached it's maximum size, dbufs are removed |
| * and destroyed. The eviction thread will continue running until the size |
| * of the dbuf cache is at or below the maximum size. Once the dbuf is aged |
| * out of the cache it is destroyed and becomes eligible for arc eviction. |
| */ |
| /* ARGSUSED */ |
| static void |
| dbuf_evict_thread(void *unused) |
| { |
| callb_cpr_t cpr; |
| |
| CALLB_CPR_INIT(&cpr, &dbuf_evict_lock, callb_generic_cpr, FTAG); |
| |
| mutex_enter(&dbuf_evict_lock); |
| while (!dbuf_evict_thread_exit) { |
| while (!dbuf_cache_above_lowater() && !dbuf_evict_thread_exit) { |
| CALLB_CPR_SAFE_BEGIN(&cpr); |
| (void) cv_timedwait_sig_hires(&dbuf_evict_cv, |
| &dbuf_evict_lock, SEC2NSEC(1), MSEC2NSEC(1), 0); |
| CALLB_CPR_SAFE_END(&cpr, &dbuf_evict_lock); |
| } |
| mutex_exit(&dbuf_evict_lock); |
| |
| /* |
| * Keep evicting as long as we're above the low water mark |
| * for the cache. We do this without holding the locks to |
| * minimize lock contention. |
| */ |
| while (dbuf_cache_above_lowater() && !dbuf_evict_thread_exit) { |
| dbuf_evict_one(); |
| } |
| |
| mutex_enter(&dbuf_evict_lock); |
| } |
| |
| dbuf_evict_thread_exit = B_FALSE; |
| cv_broadcast(&dbuf_evict_cv); |
| CALLB_CPR_EXIT(&cpr); /* drops dbuf_evict_lock */ |
| thread_exit(); |
| } |
| |
| /* |
| * Wake up the dbuf eviction thread if the dbuf cache is at its max size. |
| * If the dbuf cache is at its high water mark, then evict a dbuf from the |
| * dbuf cache using the callers context. |
| */ |
| static void |
| dbuf_evict_notify(void) |
| { |
| /* |
| * We check if we should evict without holding the dbuf_evict_lock, |
| * because it's OK to occasionally make the wrong decision here, |
| * and grabbing the lock results in massive lock contention. |
| */ |
| if (zfs_refcount_count(&dbuf_caches[DB_DBUF_CACHE].size) > |
| dbuf_cache_target_bytes()) { |
| if (dbuf_cache_above_hiwater()) |
| dbuf_evict_one(); |
| cv_signal(&dbuf_evict_cv); |
| } |
| } |
| |
| static int |
| dbuf_kstat_update(kstat_t *ksp, int rw) |
| { |
| dbuf_stats_t *ds = ksp->ks_data; |
| |
| if (rw == KSTAT_WRITE) { |
| return (SET_ERROR(EACCES)); |
| } else { |
| ds->metadata_cache_size_bytes.value.ui64 = zfs_refcount_count( |
| &dbuf_caches[DB_DBUF_METADATA_CACHE].size); |
| ds->cache_size_bytes.value.ui64 = |
| zfs_refcount_count(&dbuf_caches[DB_DBUF_CACHE].size); |
| ds->cache_target_bytes.value.ui64 = dbuf_cache_target_bytes(); |
| ds->cache_hiwater_bytes.value.ui64 = dbuf_cache_hiwater_bytes(); |
| ds->cache_lowater_bytes.value.ui64 = dbuf_cache_lowater_bytes(); |
| ds->hash_elements.value.ui64 = dbuf_hash_count; |
| } |
| |
| return (0); |
| } |
| |
| void |
| dbuf_init(void) |
| { |
| uint64_t hsize = 1ULL << 16; |
| dbuf_hash_table_t *h = &dbuf_hash_table; |
| int i; |
| |
| /* |
| * The hash table is big enough to fill all of physical memory |
| * with an average block size of zfs_arc_average_blocksize (default 8K). |
| * By default, the table will take up |
| * totalmem * sizeof(void*) / 8K (1MB per GB with 8-byte pointers). |
| */ |
| while (hsize * zfs_arc_average_blocksize < physmem * PAGESIZE) |
| hsize <<= 1; |
| |
| retry: |
| h->hash_table_mask = hsize - 1; |
| #if defined(_KERNEL) |
| /* |
| * Large allocations which do not require contiguous pages |
| * should be using vmem_alloc() in the linux kernel |
| */ |
| h->hash_table = vmem_zalloc(hsize * sizeof (void *), KM_SLEEP); |
| #else |
| h->hash_table = kmem_zalloc(hsize * sizeof (void *), KM_NOSLEEP); |
| #endif |
| if (h->hash_table == NULL) { |
| /* XXX - we should really return an error instead of assert */ |
| ASSERT(hsize > (1ULL << 10)); |
| hsize >>= 1; |
| goto retry; |
| } |
| |
| dbuf_kmem_cache = kmem_cache_create("dmu_buf_impl_t", |
| sizeof (dmu_buf_impl_t), |
| 0, dbuf_cons, dbuf_dest, NULL, NULL, NULL, 0); |
| |
| for (i = 0; i < DBUF_MUTEXES; i++) |
| mutex_init(&h->hash_mutexes[i], NULL, MUTEX_DEFAULT, NULL); |
| |
| dbuf_stats_init(h); |
| |
| /* |
| * Setup the parameters for the dbuf caches. We set the sizes of the |
| * dbuf cache and the metadata cache to 1/32nd and 1/16th (default) |
| * of the target size of the ARC. If the values has been specified as |
| * a module option and they're not greater than the target size of the |
| * ARC, then we honor that value. |
| */ |
| if (dbuf_cache_max_bytes == 0 || |
| dbuf_cache_max_bytes >= arc_target_bytes()) { |
| dbuf_cache_max_bytes = arc_target_bytes() >> dbuf_cache_shift; |
| } |
| if (dbuf_metadata_cache_max_bytes == 0 || |
| dbuf_metadata_cache_max_bytes >= arc_target_bytes()) { |
| dbuf_metadata_cache_max_bytes = |
| arc_target_bytes() >> dbuf_metadata_cache_shift; |
| } |
| |
| /* |
| * All entries are queued via taskq_dispatch_ent(), so min/maxalloc |
| * configuration is not required. |
| */ |
| dbu_evict_taskq = taskq_create("dbu_evict", 1, defclsyspri, 0, 0, 0); |
| |
| for (dbuf_cached_state_t dcs = 0; dcs < DB_CACHE_MAX; dcs++) { |
| dbuf_caches[dcs].cache = |
| multilist_create(sizeof (dmu_buf_impl_t), |
| offsetof(dmu_buf_impl_t, db_cache_link), |
| dbuf_cache_multilist_index_func); |
| zfs_refcount_create(&dbuf_caches[dcs].size); |
| } |
| |
| dbuf_evict_thread_exit = B_FALSE; |
| mutex_init(&dbuf_evict_lock, NULL, MUTEX_DEFAULT, NULL); |
| cv_init(&dbuf_evict_cv, NULL, CV_DEFAULT, NULL); |
| dbuf_cache_evict_thread = thread_create(NULL, 0, dbuf_evict_thread, |
| NULL, 0, &p0, TS_RUN, minclsyspri); |
| |
| dbuf_ksp = kstat_create("zfs", 0, "dbufstats", "misc", |
| KSTAT_TYPE_NAMED, sizeof (dbuf_stats) / sizeof (kstat_named_t), |
| KSTAT_FLAG_VIRTUAL); |
| if (dbuf_ksp != NULL) { |
| dbuf_ksp->ks_data = &dbuf_stats; |
| dbuf_ksp->ks_update = dbuf_kstat_update; |
| kstat_install(dbuf_ksp); |
| |
| for (i = 0; i < DN_MAX_LEVELS; i++) { |
| snprintf(dbuf_stats.cache_levels[i].name, |
| KSTAT_STRLEN, "cache_level_%d", i); |
| dbuf_stats.cache_levels[i].data_type = |
| KSTAT_DATA_UINT64; |
| snprintf(dbuf_stats.cache_levels_bytes[i].name, |
| KSTAT_STRLEN, "cache_level_%d_bytes", i); |
| dbuf_stats.cache_levels_bytes[i].data_type = |
| KSTAT_DATA_UINT64; |
| } |
| } |
| } |
| |
| void |
| dbuf_fini(void) |
| { |
| dbuf_hash_table_t *h = &dbuf_hash_table; |
| int i; |
| |
| dbuf_stats_destroy(); |
| |
| for (i = 0; i < DBUF_MUTEXES; i++) |
| mutex_destroy(&h->hash_mutexes[i]); |
| #if defined(_KERNEL) |
| /* |
| * Large allocations which do not require contiguous pages |
| * should be using vmem_free() in the linux kernel |
| */ |
| vmem_free(h->hash_table, (h->hash_table_mask + 1) * sizeof (void *)); |
| #else |
| kmem_free(h->hash_table, (h->hash_table_mask + 1) * sizeof (void *)); |
| #endif |
| kmem_cache_destroy(dbuf_kmem_cache); |
| taskq_destroy(dbu_evict_taskq); |
| |
| mutex_enter(&dbuf_evict_lock); |
| dbuf_evict_thread_exit = B_TRUE; |
| while (dbuf_evict_thread_exit) { |
| cv_signal(&dbuf_evict_cv); |
| cv_wait(&dbuf_evict_cv, &dbuf_evict_lock); |
| } |
| mutex_exit(&dbuf_evict_lock); |
| |
| mutex_destroy(&dbuf_evict_lock); |
| cv_destroy(&dbuf_evict_cv); |
| |
| for (dbuf_cached_state_t dcs = 0; dcs < DB_CACHE_MAX; dcs++) { |
| zfs_refcount_destroy(&dbuf_caches[dcs].size); |
| multilist_destroy(dbuf_caches[dcs].cache); |
| } |
| |
| if (dbuf_ksp != NULL) { |
| kstat_delete(dbuf_ksp); |
| dbuf_ksp = NULL; |
| } |
| } |
| |
| /* |
| * Other stuff. |
| */ |
| |
| #ifdef ZFS_DEBUG |
| static void |
| dbuf_verify(dmu_buf_impl_t *db) |
| { |
| dnode_t *dn; |
| dbuf_dirty_record_t *dr; |
| |
| ASSERT(MUTEX_HELD(&db->db_mtx)); |
| |
| if (!(zfs_flags & ZFS_DEBUG_DBUF_VERIFY)) |
| return; |
| |
| ASSERT(db->db_objset != NULL); |
| DB_DNODE_ENTER(db); |
| dn = DB_DNODE(db); |
| if (dn == NULL) { |
| ASSERT(db->db_parent == NULL); |
| ASSERT(db->db_blkptr == NULL); |
| } else { |
| ASSERT3U(db->db.db_object, ==, dn->dn_object); |
| ASSERT3P(db->db_objset, ==, dn->dn_objset); |
| ASSERT3U(db->db_level, <, dn->dn_nlevels); |
| ASSERT(db->db_blkid == DMU_BONUS_BLKID || |
| db->db_blkid == DMU_SPILL_BLKID || |
| !avl_is_empty(&dn->dn_dbufs)); |
| } |
| if (db->db_blkid == DMU_BONUS_BLKID) { |
| ASSERT(dn != NULL); |
| ASSERT3U(db->db.db_size, >=, dn->dn_bonuslen); |
| ASSERT3U(db->db.db_offset, ==, DMU_BONUS_BLKID); |
| } else if (db->db_blkid == DMU_SPILL_BLKID) { |
| ASSERT(dn != NULL); |
| ASSERT0(db->db.db_offset); |
| } else { |
| ASSERT3U(db->db.db_offset, ==, db->db_blkid * db->db.db_size); |
| } |
| |
| for (dr = db->db_data_pending; dr != NULL; dr = dr->dr_next) |
| ASSERT(dr->dr_dbuf == db); |
| |
| for (dr = db->db_last_dirty; dr != NULL; dr = dr->dr_next) |
| ASSERT(dr->dr_dbuf == db); |
| |
| /* |
| * We can't assert that db_size matches dn_datablksz because it |
| * can be momentarily different when another thread is doing |
| * dnode_set_blksz(). |
| */ |
| if (db->db_level == 0 && db->db.db_object == DMU_META_DNODE_OBJECT) { |
| dr = db->db_data_pending; |
| /* |
| * It should only be modified in syncing context, so |
| * make sure we only have one copy of the data. |
| */ |
| ASSERT(dr == NULL || dr->dt.dl.dr_data == db->db_buf); |
| } |
| |
| /* verify db->db_blkptr */ |
| if (db->db_blkptr) { |
| if (db->db_parent == dn->dn_dbuf) { |
| /* db is pointed to by the dnode */ |
| /* ASSERT3U(db->db_blkid, <, dn->dn_nblkptr); */ |
| if (DMU_OBJECT_IS_SPECIAL(db->db.db_object)) |
| ASSERT(db->db_parent == NULL); |
| else |
| ASSERT(db->db_parent != NULL); |
| if (db->db_blkid != DMU_SPILL_BLKID) |
| ASSERT3P(db->db_blkptr, ==, |
| &dn->dn_phys->dn_blkptr[db->db_blkid]); |
| } else { |
| /* db is pointed to by an indirect block */ |
| ASSERTV(int epb = db->db_parent->db.db_size >> |
| SPA_BLKPTRSHIFT); |
| ASSERT3U(db->db_parent->db_level, ==, db->db_level+1); |
| ASSERT3U(db->db_parent->db.db_object, ==, |
| db->db.db_object); |
| /* |
| * dnode_grow_indblksz() can make this fail if we don't |
| * have the struct_rwlock. XXX indblksz no longer |
| * grows. safe to do this now? |
| */ |
| if (RW_WRITE_HELD(&dn->dn_struct_rwlock)) { |
| ASSERT3P(db->db_blkptr, ==, |
| ((blkptr_t *)db->db_parent->db.db_data + |
| db->db_blkid % epb)); |
| } |
| } |
| } |
| if ((db->db_blkptr == NULL || BP_IS_HOLE(db->db_blkptr)) && |
| (db->db_buf == NULL || db->db_buf->b_data) && |
| db->db.db_data && db->db_blkid != DMU_BONUS_BLKID && |
| db->db_state != DB_FILL && !dn->dn_free_txg) { |
| /* |
| * If the blkptr isn't set but they have nonzero data, |
| * it had better be dirty, otherwise we'll lose that |
| * data when we evict this buffer. |
| * |
| * There is an exception to this rule for indirect blocks; in |
| * this case, if the indirect block is a hole, we fill in a few |
| * fields on each of the child blocks (importantly, birth time) |
| * to prevent hole birth times from being lost when you |
| * partially fill in a hole. |
| */ |
| if (db->db_dirtycnt == 0) { |
| if (db->db_level == 0) { |
| uint64_t *buf = db->db.db_data; |
| int i; |
| |
| for (i = 0; i < db->db.db_size >> 3; i++) { |
| ASSERT(buf[i] == 0); |
| } |
| } else { |
| blkptr_t *bps = db->db.db_data; |
| ASSERT3U(1 << DB_DNODE(db)->dn_indblkshift, ==, |
| db->db.db_size); |
| /* |
| * We want to verify that all the blkptrs in the |
| * indirect block are holes, but we may have |
| * automatically set up a few fields for them. |
| * We iterate through each blkptr and verify |
| * they only have those fields set. |
| */ |
| for (int i = 0; |
| i < db->db.db_size / sizeof (blkptr_t); |
| i++) { |
| blkptr_t *bp = &bps[i]; |
| ASSERT(ZIO_CHECKSUM_IS_ZERO( |
| &bp->blk_cksum)); |
| ASSERT( |
| DVA_IS_EMPTY(&bp->blk_dva[0]) && |
| DVA_IS_EMPTY(&bp->blk_dva[1]) && |
| DVA_IS_EMPTY(&bp->blk_dva[2])); |
| ASSERT0(bp->blk_fill); |
| ASSERT0(bp->blk_pad[0]); |
| ASSERT0(bp->blk_pad[1]); |
| ASSERT(!BP_IS_EMBEDDED(bp)); |
| ASSERT(BP_IS_HOLE(bp)); |
| ASSERT0(bp->blk_phys_birth); |
| } |
| } |
| } |
| } |
| DB_DNODE_EXIT(db); |
| } |
| #endif |
| |
| static void |
| dbuf_clear_data(dmu_buf_impl_t *db) |
| { |
| ASSERT(MUTEX_HELD(&db->db_mtx)); |
| dbuf_evict_user(db); |
| ASSERT3P(db->db_buf, ==, NULL); |
| db->db.db_data = NULL; |
| if (db->db_state != DB_NOFILL) |
| db->db_state = DB_UNCACHED; |
| } |
| |
| static void |
| dbuf_set_data(dmu_buf_impl_t *db, arc_buf_t *buf) |
| { |
| ASSERT(MUTEX_HELD(&db->db_mtx)); |
| ASSERT(buf != NULL); |
| |
| db->db_buf = buf; |
| ASSERT(buf->b_data != NULL); |
| db->db.db_data = buf->b_data; |
| } |
| |
| /* |
| * Loan out an arc_buf for read. Return the loaned arc_buf. |
| */ |
| arc_buf_t * |
| dbuf_loan_arcbuf(dmu_buf_impl_t *db) |
| { |
| arc_buf_t *abuf; |
| |
| ASSERT(db->db_blkid != DMU_BONUS_BLKID); |
| mutex_enter(&db->db_mtx); |
| if (arc_released(db->db_buf) || zfs_refcount_count(&db->db_holds) > 1) { |
| int blksz = db->db.db_size; |
| spa_t *spa = db->db_objset->os_spa; |
| |
| mutex_exit(&db->db_mtx); |
| abuf = arc_loan_buf(spa, B_FALSE, blksz); |
| bcopy(db->db.db_data, abuf->b_data, blksz); |
| } else { |
| abuf = db->db_buf; |
| arc_loan_inuse_buf(abuf, db); |
| db->db_buf = NULL; |
| dbuf_clear_data(db); |
| mutex_exit(&db->db_mtx); |
| } |
| return (abuf); |
| } |
| |
| /* |
| * Calculate which level n block references the data at the level 0 offset |
| * provided. |
| */ |
| uint64_t |
| dbuf_whichblock(const dnode_t *dn, const int64_t level, const uint64_t offset) |
| { |
| if (dn->dn_datablkshift != 0 && dn->dn_indblkshift != 0) { |
| /* |
| * The level n blkid is equal to the level 0 blkid divided by |
| * the number of level 0s in a level n block. |
| * |
| * The level 0 blkid is offset >> datablkshift = |
| * offset / 2^datablkshift. |
| * |
| * The number of level 0s in a level n is the number of block |
| * pointers in an indirect block, raised to the power of level. |
| * This is 2^(indblkshift - SPA_BLKPTRSHIFT)^level = |
| * 2^(level*(indblkshift - SPA_BLKPTRSHIFT)). |
| * |
| * Thus, the level n blkid is: offset / |
| * ((2^datablkshift)*(2^(level*(indblkshift-SPA_BLKPTRSHIFT)))) |
| * = offset / 2^(datablkshift + level * |
| * (indblkshift - SPA_BLKPTRSHIFT)) |
| * = offset >> (datablkshift + level * |
| * (indblkshift - SPA_BLKPTRSHIFT)) |
| */ |
| |
| const unsigned exp = dn->dn_datablkshift + |
| level * (dn->dn_indblkshift - SPA_BLKPTRSHIFT); |
| |
| if (exp >= 8 * sizeof (offset)) { |
| /* This only happens on the highest indirection level */ |
| ASSERT3U(level, ==, dn->dn_nlevels - 1); |
| return (0); |
| } |
| |
| ASSERT3U(exp, <, 8 * sizeof (offset)); |
| |
| return (offset >> exp); |
| } else { |
| ASSERT3U(offset, <, dn->dn_datablksz); |
| return (0); |
| } |
| } |
| |
| static void |
| dbuf_read_done(zio_t *zio, const zbookmark_phys_t *zb, const blkptr_t *bp, |
| arc_buf_t *buf, void *vdb) |
| { |
| dmu_buf_impl_t *db = vdb; |
| |
| mutex_enter(&db->db_mtx); |
| ASSERT3U(db->db_state, ==, DB_READ); |
| /* |
| * All reads are synchronous, so we must have a hold on the dbuf |
| */ |
| ASSERT(zfs_refcount_count(&db->db_holds) > 0); |
| ASSERT(db->db_buf == NULL); |
| ASSERT(db->db.db_data == NULL); |
| if (buf == NULL) { |
| /* i/o error */ |
| ASSERT(zio == NULL || zio->io_error != 0); |
| ASSERT(db->db_blkid != DMU_BONUS_BLKID); |
| ASSERT3P(db->db_buf, ==, NULL); |
| db->db_state = DB_UNCACHED; |
| } else if (db->db_level == 0 && db->db_freed_in_flight) { |
| /* freed in flight */ |
| ASSERT(zio == NULL || zio->io_error == 0); |
| arc_release(buf, db); |
| bzero(buf->b_data, db->db.db_size); |
| arc_buf_freeze(buf); |
| db->db_freed_in_flight = FALSE; |
| dbuf_set_data(db, buf); |
| db->db_state = DB_CACHED; |
| } else { |
| /* success */ |
| ASSERT(zio == NULL || zio->io_error == 0); |
| dbuf_set_data(db, buf); |
| db->db_state = DB_CACHED; |
| } |
| cv_broadcast(&db->db_changed); |
| dbuf_rele_and_unlock(db, NULL, B_FALSE); |
| } |
| |
| |
| /* |
| * This function ensures that, when doing a decrypting read of a block, |
| * we make sure we have decrypted the dnode associated with it. We must do |
| * this so that we ensure we are fully authenticating the checksum-of-MACs |
| * tree from the root of the objset down to this block. Indirect blocks are |
| * always verified against their secure checksum-of-MACs assuming that the |
| * dnode containing them is correct. Now that we are doing a decrypting read, |
| * we can be sure that the key is loaded and verify that assumption. This is |
| * especially important considering that we always read encrypted dnode |
| * blocks as raw data (without verifying their MACs) to start, and |
| * decrypt / authenticate them when we need to read an encrypted bonus buffer. |
| */ |
| static int |
| dbuf_read_verify_dnode_crypt(dmu_buf_impl_t *db, uint32_t flags) |
| { |
| int err = 0; |
| objset_t *os = db->db_objset; |
| arc_buf_t *dnode_abuf; |
| dnode_t *dn; |
| zbookmark_phys_t zb; |
| |
| ASSERT(MUTEX_HELD(&db->db_mtx)); |
| |
| if (!os->os_encrypted || os->os_raw_receive || |
| (flags & DB_RF_NO_DECRYPT) != 0) |
| return (0); |
| |
| DB_DNODE_ENTER(db); |
| dn = DB_DNODE(db); |
| dnode_abuf = (dn->dn_dbuf != NULL) ? dn->dn_dbuf->db_buf : NULL; |
| |
| if (dnode_abuf == NULL || !arc_is_encrypted(dnode_abuf)) { |
| DB_DNODE_EXIT(db); |
| return (0); |
| } |
| |
| SET_BOOKMARK(&zb, dmu_objset_id(os), |
| DMU_META_DNODE_OBJECT, 0, dn->dn_dbuf->db_blkid); |
| err = arc_untransform(dnode_abuf, os->os_spa, &zb, B_TRUE); |
| |
| /* |
| * An error code of EACCES tells us that the key is still not |
| * available. This is ok if we are only reading authenticated |
| * (and therefore non-encrypted) blocks. |
| */ |
| if (err == EACCES && ((db->db_blkid != DMU_BONUS_BLKID && |
| !DMU_OT_IS_ENCRYPTED(dn->dn_type)) || |
| (db->db_blkid == DMU_BONUS_BLKID && |
| !DMU_OT_IS_ENCRYPTED(dn->dn_bonustype)))) |
| err = 0; |
| |
| DB_DNODE_EXIT(db); |
| |
| return (err); |
| } |
| |
| static int |
| dbuf_read_impl(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags) |
| { |
| dnode_t *dn; |
| zbookmark_phys_t zb; |
| uint32_t aflags = ARC_FLAG_NOWAIT; |
| int err, zio_flags = 0; |
| |
| DB_DNODE_ENTER(db); |
| dn = DB_DNODE(db); |
| ASSERT(!zfs_refcount_is_zero(&db->db_holds)); |
| /* We need the struct_rwlock to prevent db_blkptr from changing. */ |
| ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock)); |
| ASSERT(MUTEX_HELD(&db->db_mtx)); |
| ASSERT(db->db_state == DB_UNCACHED); |
| ASSERT(db->db_buf == NULL); |
| |
| if (db->db_blkid == DMU_BONUS_BLKID) { |
| /* |
| * The bonus length stored in the dnode may be less than |
| * the maximum available space in the bonus buffer. |
| */ |
| int bonuslen = MIN(dn->dn_bonuslen, dn->dn_phys->dn_bonuslen); |
| int max_bonuslen = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots); |
| |
| /* if the underlying dnode block is encrypted, decrypt it */ |
| err = dbuf_read_verify_dnode_crypt(db, flags); |
| if (err != 0) { |
| DB_DNODE_EXIT(db); |
| mutex_exit(&db->db_mtx); |
| return (err); |
| } |
| |
| ASSERT3U(bonuslen, <=, db->db.db_size); |
| db->db.db_data = kmem_alloc(max_bonuslen, KM_SLEEP); |
| arc_space_consume(max_bonuslen, ARC_SPACE_BONUS); |
| if (bonuslen < max_bonuslen) |
| bzero(db->db.db_data, max_bonuslen); |
| if (bonuslen) |
| bcopy(DN_BONUS(dn->dn_phys), db->db.db_data, bonuslen); |
| DB_DNODE_EXIT(db); |
| db->db_state = DB_CACHED; |
| mutex_exit(&db->db_mtx); |
| return (0); |
| } |
| |
| /* |
| * Recheck BP_IS_HOLE() after dnode_block_freed() in case dnode_sync() |
| * processes the delete record and clears the bp while we are waiting |
| * for the dn_mtx (resulting in a "no" from block_freed). |
| */ |
| if (db->db_blkptr == NULL || BP_IS_HOLE(db->db_blkptr) || |
| (db->db_level == 0 && (dnode_block_freed(dn, db->db_blkid) || |
| BP_IS_HOLE(db->db_blkptr)))) { |
| arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db); |
| |
| dbuf_set_data(db, arc_alloc_buf(db->db_objset->os_spa, db, type, |
| db->db.db_size)); |
| bzero(db->db.db_data, db->db.db_size); |
| |
| if (db->db_blkptr != NULL && db->db_level > 0 && |
| BP_IS_HOLE(db->db_blkptr) && |
| db->db_blkptr->blk_birth != 0) { |
| blkptr_t *bps = db->db.db_data; |
| for (int i = 0; i < ((1 << |
| DB_DNODE(db)->dn_indblkshift) / sizeof (blkptr_t)); |
| i++) { |
| blkptr_t *bp = &bps[i]; |
| ASSERT3U(BP_GET_LSIZE(db->db_blkptr), ==, |
| 1 << dn->dn_indblkshift); |
| BP_SET_LSIZE(bp, |
| BP_GET_LEVEL(db->db_blkptr) == 1 ? |
| dn->dn_datablksz : |
| BP_GET_LSIZE(db->db_blkptr)); |
| BP_SET_TYPE(bp, BP_GET_TYPE(db->db_blkptr)); |
| BP_SET_LEVEL(bp, |
| BP_GET_LEVEL(db->db_blkptr) - 1); |
| BP_SET_BIRTH(bp, db->db_blkptr->blk_birth, 0); |
| } |
| } |
| DB_DNODE_EXIT(db); |
| db->db_state = DB_CACHED; |
| mutex_exit(&db->db_mtx); |
| return (0); |
| } |
| |
| |
| SET_BOOKMARK(&zb, dmu_objset_id(db->db_objset), |
| db->db.db_object, db->db_level, db->db_blkid); |
| |
| /* |
| * All bps of an encrypted os should have the encryption bit set. |
| * If this is not true it indicates tampering and we report an error. |
| */ |
| if (db->db_objset->os_encrypted && !BP_USES_CRYPT(db->db_blkptr)) { |
| spa_log_error(db->db_objset->os_spa, &zb); |
| zfs_panic_recover("unencrypted block in encrypted " |
| "object set %llu", dmu_objset_id(db->db_objset)); |
| DB_DNODE_EXIT(db); |
| mutex_exit(&db->db_mtx); |
| return (SET_ERROR(EIO)); |
| } |
| |
| err = dbuf_read_verify_dnode_crypt(db, flags); |
| if (err != 0) { |
| DB_DNODE_EXIT(db); |
| mutex_exit(&db->db_mtx); |
| return (err); |
| } |
| |
| DB_DNODE_EXIT(db); |
| |
| db->db_state = DB_READ; |
| mutex_exit(&db->db_mtx); |
| |
| if (DBUF_IS_L2CACHEABLE(db)) |
| aflags |= ARC_FLAG_L2CACHE; |
| |
| dbuf_add_ref(db, NULL); |
| |
| zio_flags = (flags & DB_RF_CANFAIL) ? |
| ZIO_FLAG_CANFAIL : ZIO_FLAG_MUSTSUCCEED; |
| |
| if ((flags & DB_RF_NO_DECRYPT) && BP_IS_PROTECTED(db->db_blkptr)) |
| zio_flags |= ZIO_FLAG_RAW; |
| |
| err = arc_read(zio, db->db_objset->os_spa, db->db_blkptr, |
| dbuf_read_done, db, ZIO_PRIORITY_SYNC_READ, zio_flags, |
| &aflags, &zb); |
| |
| return (err); |
| } |
| |
| /* |
| * This is our just-in-time copy function. It makes a copy of buffers that |
| * have been modified in a previous transaction group before we access them in |
| * the current active group. |
| * |
| * This function is used in three places: when we are dirtying a buffer for the |
| * first time in a txg, when we are freeing a range in a dnode that includes |
| * this buffer, and when we are accessing a buffer which was received compressed |
| * and later referenced in a WRITE_BYREF record. |
| * |
| * Note that when we are called from dbuf_free_range() we do not put a hold on |
| * the buffer, we just traverse the active dbuf list for the dnode. |
| */ |
| static void |
| dbuf_fix_old_data(dmu_buf_impl_t *db, uint64_t txg) |
| { |
| dbuf_dirty_record_t *dr = db->db_last_dirty; |
| |
| ASSERT(MUTEX_HELD(&db->db_mtx)); |
| ASSERT(db->db.db_data != NULL); |
| ASSERT(db->db_level == 0); |
| ASSERT(db->db.db_object != DMU_META_DNODE_OBJECT); |
| |
| if (dr == NULL || |
| (dr->dt.dl.dr_data != |
| ((db->db_blkid == DMU_BONUS_BLKID) ? db->db.db_data : db->db_buf))) |
| return; |
| |
| /* |
| * If the last dirty record for this dbuf has not yet synced |
| * and its referencing the dbuf data, either: |
| * reset the reference to point to a new copy, |
| * or (if there a no active holders) |
| * just null out the current db_data pointer. |
| */ |
| ASSERT3U(dr->dr_txg, >=, txg - 2); |
| if (db->db_blkid == DMU_BONUS_BLKID) { |
| dnode_t *dn = DB_DNODE(db); |
| int bonuslen = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots); |
| dr->dt.dl.dr_data = kmem_alloc(bonuslen, KM_SLEEP); |
| arc_space_consume(bonuslen, ARC_SPACE_BONUS); |
| bcopy(db->db.db_data, dr->dt.dl.dr_data, bonuslen); |
| } else if (zfs_refcount_count(&db->db_holds) > db->db_dirtycnt) { |
| dnode_t *dn = DB_DNODE(db); |
| int size = arc_buf_size(db->db_buf); |
| arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db); |
| spa_t *spa = db->db_objset->os_spa; |
| enum zio_compress compress_type = |
| arc_get_compression(db->db_buf); |
| |
| if (arc_is_encrypted(db->db_buf)) { |
| boolean_t byteorder; |
| uint8_t salt[ZIO_DATA_SALT_LEN]; |
| uint8_t iv[ZIO_DATA_IV_LEN]; |
| uint8_t mac[ZIO_DATA_MAC_LEN]; |
| |
| arc_get_raw_params(db->db_buf, &byteorder, salt, |
| iv, mac); |
| dr->dt.dl.dr_data = arc_alloc_raw_buf(spa, db, |
| dmu_objset_id(dn->dn_objset), byteorder, salt, iv, |
| mac, dn->dn_type, size, arc_buf_lsize(db->db_buf), |
| compress_type); |
| } else if (compress_type != ZIO_COMPRESS_OFF) { |
| ASSERT3U(type, ==, ARC_BUFC_DATA); |
| dr->dt.dl.dr_data = arc_alloc_compressed_buf(spa, db, |
| size, arc_buf_lsize(db->db_buf), compress_type); |
| } else { |
| dr->dt.dl.dr_data = arc_alloc_buf(spa, db, type, size); |
| } |
| bcopy(db->db.db_data, dr->dt.dl.dr_data->b_data, size); |
| } else { |
| db->db_buf = NULL; |
| dbuf_clear_data(db); |
| } |
| } |
| |
| int |
| dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags) |
| { |
| int err = 0; |
| boolean_t prefetch; |
| dnode_t *dn; |
| |
| /* |
| * We don't have to hold the mutex to check db_state because it |
| * can't be freed while we have a hold on the buffer. |
| */ |
| ASSERT(!zfs_refcount_is_zero(&db->db_holds)); |
| |
| if (db->db_state == DB_NOFILL) |
| return (SET_ERROR(EIO)); |
| |
| DB_DNODE_ENTER(db); |
| dn = DB_DNODE(db); |
| if ((flags & DB_RF_HAVESTRUCT) == 0) |
| rw_enter(&dn->dn_struct_rwlock, RW_READER); |
| |
| prefetch = db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID && |
| (flags & DB_RF_NOPREFETCH) == 0 && dn != NULL && |
| DBUF_IS_CACHEABLE(db); |
| |
| mutex_enter(&db->db_mtx); |
| if (db->db_state == DB_CACHED) { |
| spa_t *spa = dn->dn_objset->os_spa; |
| |
| /* |
| * Ensure that this block's dnode has been decrypted if |
| * the caller has requested decrypted data. |
| */ |
| err = dbuf_read_verify_dnode_crypt(db, flags); |
| |
| /* |
| * If the arc buf is compressed or encrypted and the caller |
| * requested uncompressed data, we need to untransform it |
| * before returning. We also call arc_untransform() on any |
| * unauthenticated blocks, which will verify their MAC if |
| * the key is now available. |
| */ |
| if (err == 0 && db->db_buf != NULL && |
| (flags & DB_RF_NO_DECRYPT) == 0 && |
| (arc_is_encrypted(db->db_buf) || |
| arc_is_unauthenticated(db->db_buf) || |
| arc_get_compression(db->db_buf) != ZIO_COMPRESS_OFF)) { |
| zbookmark_phys_t zb; |
| |
| SET_BOOKMARK(&zb, dmu_objset_id(db->db_objset), |
| db->db.db_object, db->db_level, db->db_blkid); |
| dbuf_fix_old_data(db, spa_syncing_txg(spa)); |
| err = arc_untransform(db->db_buf, spa, &zb, B_FALSE); |
| dbuf_set_data(db, db->db_buf); |
| } |
| mutex_exit(&db->db_mtx); |
| if (err == 0 && prefetch) |
| dmu_zfetch(&dn->dn_zfetch, db->db_blkid, 1, B_TRUE); |
| if ((flags & DB_RF_HAVESTRUCT) == 0) |
| rw_exit(&dn->dn_struct_rwlock); |
| DB_DNODE_EXIT(db); |
| DBUF_STAT_BUMP(hash_hits); |
| } else if (db->db_state == DB_UNCACHED) { |
| spa_t *spa = dn->dn_objset->os_spa; |
| boolean_t need_wait = B_FALSE; |
| |
| if (zio == NULL && |
| db->db_blkptr != NULL && !BP_IS_HOLE(db->db_blkptr)) { |
| zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL); |
| need_wait = B_TRUE; |
| } |
| err = dbuf_read_impl(db, zio, flags); |
| |
| /* dbuf_read_impl has dropped db_mtx for us */ |
| |
| if (!err && prefetch) |
| dmu_zfetch(&dn->dn_zfetch, db->db_blkid, 1, B_TRUE); |
| |
| if ((flags & DB_RF_HAVESTRUCT) == 0) |
| rw_exit(&dn->dn_struct_rwlock); |
| DB_DNODE_EXIT(db); |
| DBUF_STAT_BUMP(hash_misses); |
| |
| /* |
| * If we created a zio_root we must execute it to avoid |
| * leaking it, even if it isn't attached to any work due |
| * to an error in dbuf_read_impl(). |
| */ |
| if (need_wait) { |
| if (err == 0) |
| err = zio_wait(zio); |
| else |
| VERIFY0(zio_wait(zio)); |
| } |
| } else { |
| /* |
| * Another reader came in while the dbuf was in flight |
| * between UNCACHED and CACHED. Either a writer will finish |
| * writing the buffer (sending the dbuf to CACHED) or the |
| * first reader's request will reach the read_done callback |
| * and send the dbuf to CACHED. Otherwise, a failure |
| * occurred and the dbuf went to UNCACHED. |
| */ |
| mutex_exit(&db->db_mtx); |
| if (prefetch) |
| dmu_zfetch(&dn->dn_zfetch, db->db_blkid, 1, B_TRUE); |
| if ((flags & DB_RF_HAVESTRUCT) == 0) |
| rw_exit(&dn->dn_struct_rwlock); |
| DB_DNODE_EXIT(db); |
| DBUF_STAT_BUMP(hash_misses); |
| |
| /* Skip the wait per the caller's request. */ |
| mutex_enter(&db->db_mtx); |
| if ((flags & DB_RF_NEVERWAIT) == 0) { |
| while (db->db_state == DB_READ || |
| db->db_state == DB_FILL) { |
| ASSERT(db->db_state == DB_READ || |
| (flags & DB_RF_HAVESTRUCT) == 0); |
| DTRACE_PROBE2(blocked__read, dmu_buf_impl_t *, |
| db, zio_t *, zio); |
| cv_wait(&db->db_changed, &db->db_mtx); |
| } |
| if (db->db_state == DB_UNCACHED) |
| err = SET_ERROR(EIO); |
| } |
| mutex_exit(&db->db_mtx); |
| } |
| |
| return (err); |
| } |
| |
| static void |
| dbuf_noread(dmu_buf_impl_t *db) |
| { |
| ASSERT(!zfs_refcount_is_zero(&db->db_holds)); |
| ASSERT(db->db_blkid != DMU_BONUS_BLKID); |
| mutex_enter(&db->db_mtx); |
| while (db->db_state == DB_READ || db->db_state == DB_FILL) |
| cv_wait(&db->db_changed, &db->db_mtx); |
| if (db->db_state == DB_UNCACHED) { |
| arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db); |
| spa_t *spa = db->db_objset->os_spa; |
| |
| ASSERT(db->db_buf == NULL); |
| ASSERT(db->db.db_data == NULL); |
| dbuf_set_data(db, arc_alloc_buf(spa, db, type, db->db.db_size)); |
| db->db_state = DB_FILL; |
| } else if (db->db_state == DB_NOFILL) { |
| dbuf_clear_data(db); |
| } else { |
| ASSERT3U(db->db_state, ==, DB_CACHED); |
| } |
| mutex_exit(&db->db_mtx); |
| } |
| |
| void |
| dbuf_unoverride(dbuf_dirty_record_t *dr) |
| { |
| dmu_buf_impl_t *db = dr->dr_dbuf; |
| blkptr_t *bp = &dr->dt.dl.dr_overridden_by; |
| uint64_t txg = dr->dr_txg; |
| |
| ASSERT(MUTEX_HELD(&db->db_mtx)); |
| /* |
| * This assert is valid because dmu_sync() expects to be called by |
| * a zilog's get_data while holding a range lock. This call only |
| * comes from dbuf_dirty() callers who must also hold a range lock. |
| */ |
| ASSERT(dr->dt.dl.dr_override_state != DR_IN_DMU_SYNC); |
| ASSERT(db->db_level == 0); |
| |
| if (db->db_blkid == DMU_BONUS_BLKID || |
| dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN) |
| return; |
| |
| ASSERT(db->db_data_pending != dr); |
| |
| /* free this block */ |
| if (!BP_IS_HOLE(bp) && !dr->dt.dl.dr_nopwrite) |
| zio_free(db->db_objset->os_spa, txg, bp); |
| |
| dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN; |
| dr->dt.dl.dr_nopwrite = B_FALSE; |
| dr->dt.dl.dr_has_raw_params = B_FALSE; |
| |
| /* |
| * Release the already-written buffer, so we leave it in |
| * a consistent dirty state. Note that all callers are |
| * modifying the buffer, so they will immediately do |
| * another (redundant) arc_release(). Therefore, leave |
| * the buf thawed to save the effort of freezing & |
| * immediately re-thawing it. |
| */ |
| arc_release(dr->dt.dl.dr_data, db); |
| } |
| |
| /* |
| * Evict (if its unreferenced) or clear (if its referenced) any level-0 |
| * data blocks in the free range, so that any future readers will find |
| * empty blocks. |
| */ |
| void |
| dbuf_free_range(dnode_t *dn, uint64_t start_blkid, uint64_t end_blkid, |
| dmu_tx_t *tx) |
| { |
| dmu_buf_impl_t *db_search; |
| dmu_buf_impl_t *db, *db_next; |
| uint64_t txg = tx->tx_txg; |
| avl_index_t where; |
| |
| if (end_blkid > dn->dn_maxblkid && |
| !(start_blkid == DMU_SPILL_BLKID || end_blkid == DMU_SPILL_BLKID)) |
| end_blkid = dn->dn_maxblkid; |
| dprintf_dnode(dn, "start=%llu end=%llu\n", start_blkid, end_blkid); |
| |
| db_search = kmem_alloc(sizeof (dmu_buf_impl_t), KM_SLEEP); |
| db_search->db_level = 0; |
| db_search->db_blkid = start_blkid; |
| db_search->db_state = DB_SEARCH; |
| |
| mutex_enter(&dn->dn_dbufs_mtx); |
| db = avl_find(&dn->dn_dbufs, db_search, &where); |
| ASSERT3P(db, ==, NULL); |
| |
| db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER); |
| |
| for (; db != NULL; db = db_next) { |
| db_next = AVL_NEXT(&dn->dn_dbufs, db); |
| ASSERT(db->db_blkid != DMU_BONUS_BLKID); |
| |
| if (db->db_level != 0 || db->db_blkid > end_blkid) { |
| break; |
| } |
| ASSERT3U(db->db_blkid, >=, start_blkid); |
| |
| /* found a level 0 buffer in the range */ |
| mutex_enter(&db->db_mtx); |
| if (dbuf_undirty(db, tx)) { |
| /* mutex has been dropped and dbuf destroyed */ |
| continue; |
| } |
| |
| if (db->db_state == DB_UNCACHED || |
| db->db_state == DB_NOFILL || |
| db->db_state == DB_EVICTING) { |
| ASSERT(db->db.db_data == NULL); |
| mutex_exit(&db->db_mtx); |
| continue; |
| } |
| if (db->db_state == DB_READ || db->db_state == DB_FILL) { |
| /* will be handled in dbuf_read_done or dbuf_rele */ |
| db->db_freed_in_flight = TRUE; |
| mutex_exit(&db->db_mtx); |
| continue; |
| } |
| if (zfs_refcount_count(&db->db_holds) == 0) { |
| ASSERT(db->db_buf); |
| dbuf_destroy(db); |
| continue; |
| } |
| /* The dbuf is referenced */ |
| |
| if (db->db_last_dirty != NULL) { |
| dbuf_dirty_record_t *dr = db->db_last_dirty; |
| |
| if (dr->dr_txg == txg) { |
| /* |
| * This buffer is "in-use", re-adjust the file |
| * size to reflect that this buffer may |
| * contain new data when we sync. |
| */ |
| if (db->db_blkid != DMU_SPILL_BLKID && |
| db->db_blkid > dn->dn_maxblkid) |
| dn->dn_maxblkid = db->db_blkid; |
| dbuf_unoverride(dr); |
| } else { |
| /* |
| * This dbuf is not dirty in the open context. |
| * Either uncache it (if its not referenced in |
| * the open context) or reset its contents to |
| * empty. |
| */ |
| dbuf_fix_old_data(db, txg); |
| } |
| } |
| /* clear the contents if its cached */ |
| if (db->db_state == DB_CACHED) { |
| ASSERT(db->db.db_data != NULL); |
| arc_release(db->db_buf, db); |
| bzero(db->db.db_data, db->db.db_size); |
| arc_buf_freeze(db->db_buf); |
| } |
| |
| mutex_exit(&db->db_mtx); |
| } |
| |
| kmem_free(db_search, sizeof (dmu_buf_impl_t)); |
| mutex_exit(&dn->dn_dbufs_mtx); |
| } |
| |
| void |
| dbuf_new_size(dmu_buf_impl_t *db, int size, dmu_tx_t *tx) |
| { |
| arc_buf_t *buf, *obuf; |
| int osize = db->db.db_size; |
| arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db); |
| dnode_t *dn; |
| |
| ASSERT(db->db_blkid != DMU_BONUS_BLKID); |
| |
| DB_DNODE_ENTER(db); |
| dn = DB_DNODE(db); |
| |
| /* XXX does *this* func really need the lock? */ |
| ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock)); |
| |
| /* |
| * This call to dmu_buf_will_dirty() with the dn_struct_rwlock held |
| * is OK, because there can be no other references to the db |
| * when we are changing its size, so no concurrent DB_FILL can |
| * be happening. |
| */ |
| /* |
| * XXX we should be doing a dbuf_read, checking the return |
| * value and returning that up to our callers |
| */ |
| dmu_buf_will_dirty(&db->db, tx); |
| |
| /* create the data buffer for the new block */ |
| buf = arc_alloc_buf(dn->dn_objset->os_spa, db, type, size); |
| |
| /* copy old block data to the new block */ |
| obuf = db->db_buf; |
| bcopy(obuf->b_data, buf->b_data, MIN(osize, size)); |
| /* zero the remainder */ |
| if (size > osize) |
| bzero((uint8_t *)buf->b_data + osize, size - osize); |
| |
| mutex_enter(&db->db_mtx); |
| dbuf_set_data(db, buf); |
| arc_buf_destroy(obuf, db); |
| db->db.db_size = size; |
| |
| if (db->db_level == 0) { |
| db->db_last_dirty->dt.dl.dr_data = buf; |
| } |
| ASSERT3U(db->db_last_dirty->dr_txg, ==, tx->tx_txg); |
| ASSERT3U(db->db_last_dirty->dr_accounted, ==, osize); |
| db->db_last_dirty->dr_accounted = size; |
| mutex_exit(&db->db_mtx); |
| |
| dmu_objset_willuse_space(dn->dn_objset, size - osize, tx); |
| DB_DNODE_EXIT(db); |
| } |
| |
| void |
| dbuf_release_bp(dmu_buf_impl_t *db) |
| { |
| ASSERTV(objset_t *os = db->db_objset); |
| |
| ASSERT(dsl_pool_sync_context(dmu_objset_pool(os))); |
| ASSERT(arc_released(os->os_phys_buf) || |
| list_link_active(&os->os_dsl_dataset->ds_synced_link)); |
| ASSERT(db->db_parent == NULL || arc_released(db->db_parent->db_buf)); |
| |
| (void) arc_release(db->db_buf, db); |
| } |
| |
| /* |
| * We already have a dirty record for this TXG, and we are being |
| * dirtied again. |
| */ |
| static void |
| dbuf_redirty(dbuf_dirty_record_t *dr) |
| { |
| dmu_buf_impl_t *db = dr->dr_dbuf; |
| |
| ASSERT(MUTEX_HELD(&db->db_mtx)); |
| |
| if (db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID) { |
| /* |
| * If this buffer has already been written out, |
| * we now need to reset its state. |
| */ |
| dbuf_unoverride(dr); |
| if (db->db.db_object != DMU_META_DNODE_OBJECT && |
| db->db_state != DB_NOFILL) { |
| /* Already released on initial dirty, so just thaw. */ |
| ASSERT(arc_released(db->db_buf)); |
| arc_buf_thaw(db->db_buf); |
| } |
| } |
| } |
| |
| dbuf_dirty_record_t * |
| dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx) |
| { |
| dnode_t *dn; |
| objset_t *os; |
| dbuf_dirty_record_t **drp, *dr; |
| int drop_struct_lock = FALSE; |
| int txgoff = tx->tx_txg & TXG_MASK; |
| |
| ASSERT(tx->tx_txg != 0); |
| ASSERT(!zfs_refcount_is_zero(&db->db_holds)); |
| DMU_TX_DIRTY_BUF(tx, db); |
| |
| DB_DNODE_ENTER(db); |
| dn = DB_DNODE(db); |
| /* |
| * Shouldn't dirty a regular buffer in syncing context. Private |
| * objects may be dirtied in syncing context, but only if they |
| * were already pre-dirtied in open context. |
| */ |
| #ifdef DEBUG |
| if (dn->dn_objset->os_dsl_dataset != NULL) { |
| rrw_enter(&dn->dn_objset->os_dsl_dataset->ds_bp_rwlock, |
| RW_READER, FTAG); |
| } |
| ASSERT(!dmu_tx_is_syncing(tx) || |
| BP_IS_HOLE(dn->dn_objset->os_rootbp) || |
| DMU_OBJECT_IS_SPECIAL(dn->dn_object) || |
| dn->dn_objset->os_dsl_dataset == NULL); |
| if (dn->dn_objset->os_dsl_dataset != NULL) |
| rrw_exit(&dn->dn_objset->os_dsl_dataset->ds_bp_rwlock, FTAG); |
| #endif |
| /* |
| * We make this assert for private objects as well, but after we |
| * check if we're already dirty. They are allowed to re-dirty |
| * in syncing context. |
| */ |
| ASSERT(dn->dn_object == DMU_META_DNODE_OBJECT || |
| dn->dn_dirtyctx == DN_UNDIRTIED || dn->dn_dirtyctx == |
| (dmu_tx_is_syncing(tx) ? DN_DIRTY_SYNC : DN_DIRTY_OPEN)); |
| |
| mutex_enter(&db->db_mtx); |
| /* |
| * XXX make this true for indirects too? The problem is that |
| * transactions created with dmu_tx_create_assigned() from |
| * syncing context don't bother holding ahead. |
| */ |
| ASSERT(db->db_level != 0 || |
| db->db_state == DB_CACHED || db->db_state == DB_FILL || |
| db->db_state == DB_NOFILL); |
| |
| mutex_enter(&dn->dn_mtx); |
| /* |
| * Don't set dirtyctx to SYNC if we're just modifying this as we |
| * initialize the objset. |
| */ |
| if (dn->dn_dirtyctx == DN_UNDIRTIED) { |
| if (dn->dn_objset->os_dsl_dataset != NULL) { |
| rrw_enter(&dn->dn_objset->os_dsl_dataset->ds_bp_rwlock, |
| RW_READER, FTAG); |
| } |
| if (!BP_IS_HOLE(dn->dn_objset->os_rootbp)) { |
| dn->dn_dirtyctx = (dmu_tx_is_syncing(tx) ? |
| DN_DIRTY_SYNC : DN_DIRTY_OPEN); |
| ASSERT(dn->dn_dirtyctx_firstset == NULL); |
| dn->dn_dirtyctx_firstset = kmem_alloc(1, KM_SLEEP); |
| } |
| if (dn->dn_objset->os_dsl_dataset != NULL) { |
| rrw_exit(&dn->dn_objset->os_dsl_dataset->ds_bp_rwlock, |
| FTAG); |
| } |
| } |
| |
| if (tx->tx_txg > dn->dn_dirty_txg) |
| dn->dn_dirty_txg = tx->tx_txg; |
| mutex_exit(&dn->dn_mtx); |
| |
| if (db->db_blkid == DMU_SPILL_BLKID) |
| dn->dn_have_spill = B_TRUE; |
| |
| /* |
| * If this buffer is already dirty, we're done. |
| */ |
| drp = &db->db_last_dirty; |
| ASSERT(*drp == NULL || (*drp)->dr_txg <= tx->tx_txg || |
| db->db.db_object == DMU_META_DNODE_OBJECT); |
| while ((dr = *drp) != NULL && dr->dr_txg > tx->tx_txg) |
| drp = &dr->dr_next; |
| if (dr && dr->dr_txg == tx->tx_txg) { |
| DB_DNODE_EXIT(db); |
| |
| dbuf_redirty(dr); |
| mutex_exit(&db->db_mtx); |
| return (dr); |
| } |
| |
| /* |
| * Only valid if not already dirty. |
| */ |
| ASSERT(dn->dn_object == 0 || |
| dn->dn_dirtyctx == DN_UNDIRTIED || dn->dn_dirtyctx == |
| (dmu_tx_is_syncing(tx) ? DN_DIRTY_SYNC : DN_DIRTY_OPEN)); |
| |
| ASSERT3U(dn->dn_nlevels, >, db->db_level); |
| |
| /* |
| * We should only be dirtying in syncing context if it's the |
| * mos or we're initializing the os or it's a special object. |
| * However, we are allowed to dirty in syncing context provided |
| * we already dirtied it in open context. Hence we must make |
| * this assertion only if we're not already dirty. |
| */ |
| os = dn->dn_objset; |
| VERIFY3U(tx->tx_txg, <=, spa_final_dirty_txg(os->os_spa)); |
| #ifdef DEBUG |
| if (dn->dn_objset->os_dsl_dataset != NULL) |
| rrw_enter(&os->os_dsl_dataset->ds_bp_rwlock, RW_READER, FTAG); |
| ASSERT(!dmu_tx_is_syncing(tx) || DMU_OBJECT_IS_SPECIAL(dn->dn_object) || |
| os->os_dsl_dataset == NULL || BP_IS_HOLE(os->os_rootbp)); |
| if (dn->dn_objset->os_dsl_dataset != NULL) |
| rrw_exit(&os->os_dsl_dataset->ds_bp_rwlock, FTAG); |
| #endif |
| ASSERT(db->db.db_size != 0); |
| |
| dprintf_dbuf(db, "size=%llx\n", (u_longlong_t)db->db.db_size); |
| |
| if (db->db_blkid != DMU_BONUS_BLKID) { |
| dmu_objset_willuse_space(os, db->db.db_size, tx); |
| } |
| |
| /* |
| * If this buffer is dirty in an old transaction group we need |
| * to make a copy of it so that the changes we make in this |
| * transaction group won't leak out when we sync the older txg. |
| */ |
| dr = kmem_zalloc(sizeof (dbuf_dirty_record_t), KM_SLEEP); |
| list_link_init(&dr->dr_dirty_node); |
| if (db->db_level == 0) { |
| void *data_old = db->db_buf; |
| |
| if (db->db_state != DB_NOFILL) { |
| if (db->db_blkid == DMU_BONUS_BLKID) { |
| dbuf_fix_old_data(db, tx->tx_txg); |
| data_old = db->db.db_data; |
| } else if (db->db.db_object != DMU_META_DNODE_OBJECT) { |
| /* |
| * Release the data buffer from the cache so |
| * that we can modify it without impacting |
| * possible other users of this cached data |
| * block. Note that indirect blocks and |
| * private objects are not released until the |
| * syncing state (since they are only modified |
| * then). |
| */ |
| arc_release(db->db_buf, db); |
| dbuf_fix_old_data(db, tx->tx_txg); |
| data_old = db->db_buf; |
| } |
| ASSERT(data_old != NULL); |
| } |
| dr->dt.dl.dr_data = data_old; |
| } else { |
| mutex_init(&dr->dt.di.dr_mtx, NULL, MUTEX_NOLOCKDEP, NULL); |
| list_create(&dr->dt.di.dr_children, |
| sizeof (dbuf_dirty_record_t), |
| offsetof(dbuf_dirty_record_t, dr_dirty_node)); |
| } |
| if (db->db_blkid != DMU_BONUS_BLKID) |
| dr->dr_accounted = db->db.db_size; |
| dr->dr_dbuf = db; |
| dr->dr_txg = tx->tx_txg; |
| dr->dr_next = *drp; |
| *drp = dr; |
| |
| /* |
| * We could have been freed_in_flight between the dbuf_noread |
| * and dbuf_dirty. We win, as though the dbuf_noread() had |
| * happened after the free. |
| */ |
| if (db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID && |
| db->db_blkid != DMU_SPILL_BLKID) { |
| mutex_enter(&dn->dn_mtx); |
| if (dn->dn_free_ranges[txgoff] != NULL) { |
| range_tree_clear(dn->dn_free_ranges[txgoff], |
| db->db_blkid, 1); |
| } |
| mutex_exit(&dn->dn_mtx); |
| db->db_freed_in_flight = FALSE; |
| } |
| |
| /* |
| * This buffer is now part of this txg |
| */ |
| dbuf_add_ref(db, (void *)(uintptr_t)tx->tx_txg); |
| db->db_dirtycnt += 1; |
| ASSERT3U(db->db_dirtycnt, <=, 3); |
| |
| mutex_exit(&db->db_mtx); |
| |
| if (db->db_blkid == DMU_BONUS_BLKID || |
| db->db_blkid == DMU_SPILL_BLKID) { |
| mutex_enter(&dn->dn_mtx); |
| ASSERT(!list_link_active(&dr->dr_dirty_node)); |
| list_insert_tail(&dn->dn_dirty_records[txgoff], dr); |
| mutex_exit(&dn->dn_mtx); |
| dnode_setdirty(dn, tx); |
| DB_DNODE_EXIT(db); |
| return (dr); |
| } |
| |
| /* |
| * The dn_struct_rwlock prevents db_blkptr from changing |
| * due to a write from syncing context completing |
| * while we are running, so we want to acquire it before |
| * looking at db_blkptr. |
| */ |
| if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) { |
| rw_enter(&dn->dn_struct_rwlock, RW_READER); |
| drop_struct_lock = TRUE; |
| } |
| |
| /* |
| * We need to hold the dn_struct_rwlock to make this assertion, |
| * because it protects dn_phys / dn_next_nlevels from changing. |
| */ |
| ASSERT((dn->dn_phys->dn_nlevels == 0 && db->db_level == 0) || |
| dn->dn_phys->dn_nlevels > db->db_level || |
| dn->dn_next_nlevels[txgoff] > db->db_level || |
| dn->dn_next_nlevels[(tx->tx_txg-1) & TXG_MASK] > db->db_level || |
| dn->dn_next_nlevels[(tx->tx_txg-2) & TXG_MASK] > db->db_level); |
| |
| /* |
| * If we are overwriting a dedup BP, then unless it is snapshotted, |
| * when we get to syncing context we will need to decrement its |
| * refcount in the DDT. Prefetch the relevant DDT block so that |
| * syncing context won't have to wait for the i/o. |
| */ |
| ddt_prefetch(os->os_spa, db->db_blkptr); |
| |
| if (db->db_level == 0) { |
| ASSERT(!db->db_objset->os_raw_receive || |
| dn->dn_maxblkid >= db->db_blkid); |
| dnode_new_blkid(dn, db->db_blkid, tx, |
| drop_struct_lock, B_FALSE); |
| ASSERT(dn->dn_maxblkid >= db->db_blkid); |
| } |
| |
| if (db->db_level+1 < dn->dn_nlevels) { |
| dmu_buf_impl_t *parent = db->db_parent; |
| dbuf_dirty_record_t *di; |
| int parent_held = FALSE; |
| |
| if (db->db_parent == NULL || db->db_parent == dn->dn_dbuf) { |
| int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; |
| |
| parent = dbuf_hold_level(dn, db->db_level+1, |
| db->db_blkid >> epbs, FTAG); |
| ASSERT(parent != NULL); |
| parent_held = TRUE; |
| } |
| if (drop_struct_lock) |
| rw_exit(&dn->dn_struct_rwlock); |
| ASSERT3U(db->db_level+1, ==, parent->db_level); |
| di = dbuf_dirty(parent, tx); |
| if (parent_held) |
| dbuf_rele(parent, FTAG); |
| |
| mutex_enter(&db->db_mtx); |
| /* |
| * Since we've dropped the mutex, it's possible that |
| * dbuf_undirty() might have changed this out from under us. |
| */ |
| if (db->db_last_dirty == dr || |
| dn->dn_object == DMU_META_DNODE_OBJECT) { |
| mutex_enter(&di->dt.di.dr_mtx); |
| ASSERT3U(di->dr_txg, ==, tx->tx_txg); |
| ASSERT(!list_link_active(&dr->dr_dirty_node)); |
| list_insert_tail(&di->dt.di.dr_children, dr); |
| mutex_exit(&di->dt.di.dr_mtx); |
| dr->dr_parent = di; |
| } |
| mutex_exit(&db->db_mtx); |
| } else { |
| ASSERT(db->db_level+1 == dn->dn_nlevels); |
| ASSERT(db->db_blkid < dn->dn_nblkptr); |
| ASSERT(db->db_parent == NULL || db->db_parent == dn->dn_dbuf); |
| mutex_enter(&dn->dn_mtx); |
| ASSERT(!list_link_active(&dr->dr_dirty_node)); |
| list_insert_tail(&dn->dn_dirty_records[txgoff], dr); |
| mutex_exit(&dn->dn_mtx); |
| if (drop_struct_lock) |
| rw_exit(&dn->dn_struct_rwlock); |
| } |
| |
| dnode_setdirty(dn, tx); |
| DB_DNODE_EXIT(db); |
| return (dr); |
| } |
| |
| /* |
| * Undirty a buffer in the transaction group referenced by the given |
| * transaction. Return whether this evicted the dbuf. |
| */ |
| static boolean_t |
| dbuf_undirty(dmu_buf_impl_t *db, dmu_tx_t *tx) |
| { |
| dnode_t *dn; |
| uint64_t txg = tx->tx_txg; |
| dbuf_dirty_record_t *dr, **drp; |
| |
| ASSERT(txg != 0); |
| |
| /* |
| * Due to our use of dn_nlevels below, this can only be called |
| * in open context, unless we are operating on the MOS. |
| * From syncing context, dn_nlevels may be different from the |
| * dn_nlevels used when dbuf was dirtied. |
| */ |
| ASSERT(db->db_objset == |
| dmu_objset_pool(db->db_objset)->dp_meta_objset || |
| txg != spa_syncing_txg(dmu_objset_spa(db->db_objset))); |
| ASSERT(db->db_blkid != DMU_BONUS_BLKID); |
| ASSERT0(db->db_level); |
| ASSERT(MUTEX_HELD(&db->db_mtx)); |
| |
| /* |
| * If this buffer is not dirty, we're done. |
| */ |
| for (drp = &db->db_last_dirty; (dr = *drp) != NULL; drp = &dr->dr_next) |
| if (dr->dr_txg <= txg) |
| break; |
| if (dr == NULL || dr->dr_txg < txg) |
| return (B_FALSE); |
| ASSERT(dr->dr_txg == txg); |
| ASSERT(dr->dr_dbuf == db); |
| |
| DB_DNODE_ENTER(db); |
| dn = DB_DNODE(db); |
| |
| dprintf_dbuf(db, "size=%llx\n", (u_longlong_t)db->db.db_size); |
| |
| ASSERT(db->db.db_size != 0); |
| |
| dsl_pool_undirty_space(dmu_objset_pool(dn->dn_objset), |
| dr->dr_accounted, txg); |
| |
| *drp = dr->dr_next; |
| |
| /* |
| * Note that there are three places in dbuf_dirty() |
| * where this dirty record may be put on a list. |
| * Make sure to do a list_remove corresponding to |
| * every one of those list_insert calls. |
| */ |
| if (dr->dr_parent) { |
| mutex_enter(&dr->dr_parent->dt.di.dr_mtx); |
| list_remove(&dr->dr_parent->dt.di.dr_children, dr); |
| mutex_exit(&dr->dr_parent->dt.di.dr_mtx); |
| } else if (db->db_blkid == DMU_SPILL_BLKID || |
| db->db_level + 1 == dn->dn_nlevels) { |
| ASSERT(db->db_blkptr == NULL || db->db_parent == dn->dn_dbuf); |
| mutex_enter(&dn->dn_mtx); |
| list_remove(&dn->dn_dirty_records[txg & TXG_MASK], dr); |
| mutex_exit(&dn->dn_mtx); |
| } |
| DB_DNODE_EXIT(db); |
| |
| if (db->db_state != DB_NOFILL) { |
| dbuf_unoverride(dr); |
| |
| ASSERT(db->db_buf != NULL); |
| ASSERT(dr->dt.dl.dr_data != NULL); |
| if (dr->dt.dl.dr_data != db->db_buf) |
| arc_buf_destroy(dr->dt.dl.dr_data, db); |
| } |
| |
| kmem_free(dr, sizeof (dbuf_dirty_record_t)); |
| |
| ASSERT(db->db_dirtycnt > 0); |
| db->db_dirtycnt -= 1; |
| |
| if (zfs_refcount_remove(&db->db_holds, (void *)(uintptr_t)txg) == 0) { |
| ASSERT(db->db_state == DB_NOFILL || arc_released(db->db_buf)); |
| dbuf_destroy(db); |
| return (B_TRUE); |
| } |
| |
| return (B_FALSE); |
| } |
| |
| static void |
| dmu_buf_will_dirty_impl(dmu_buf_t *db_fake, int flags, dmu_tx_t *tx) |
| { |
| dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; |
| |
| ASSERT(tx->tx_txg != 0); |
| ASSERT(!zfs_refcount_is_zero(&db->db_holds)); |
| |
| /* |
| * Quick check for dirtiness. For already dirty blocks, this |
| * reduces runtime of this function by >90%, and overall performance |
| * by 50% for some workloads (e.g. file deletion with indirect blocks |
| * cached). |
| */ |
| mutex_enter(&db->db_mtx); |
| |
| dbuf_dirty_record_t *dr; |
| for (dr = db->db_last_dirty; |
| dr != NULL && dr->dr_txg >= tx->tx_txg; dr = dr->dr_next) { |
| /* |
| * It's possible that it is already dirty but not cached, |
| * because there are some calls to dbuf_dirty() that don't |
| * go through dmu_buf_will_dirty(). |
| */ |
| if (dr->dr_txg == tx->tx_txg && db->db_state == DB_CACHED) { |
| /* This dbuf is already dirty and cached. */ |
| dbuf_redirty(dr); |
| mutex_exit(&db->db_mtx); |
| return; |
| } |
| } |
| mutex_exit(&db->db_mtx); |
| |
| DB_DNODE_ENTER(db); |
| if (RW_WRITE_HELD(&DB_DNODE(db)->dn_struct_rwlock)) |
| flags |= DB_RF_HAVESTRUCT; |
| DB_DNODE_EXIT(db); |
| (void) dbuf_read(db, NULL, flags); |
| (void) dbuf_dirty(db, tx); |
| } |
| |
| void |
| dmu_buf_will_dirty(dmu_buf_t *db_fake, dmu_tx_t *tx) |
| { |
| dmu_buf_will_dirty_impl(db_fake, |
| DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH, tx); |
| } |
| |
| boolean_t |
| dmu_buf_is_dirty(dmu_buf_t *db_fake, dmu_tx_t *tx) |
| { |
| dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; |
| |
| mutex_enter(&db->db_mtx); |
| for (dbuf_dirty_record_t *dr = db->db_last_dirty; |
| dr != NULL && dr->dr_txg >= tx->tx_txg; dr = dr->dr_next) { |
| if (dr->dr_txg == tx->tx_txg) { |
| mutex_exit(&db->db_mtx); |
| return (B_TRUE); |
| } |
| } |
| mutex_exit(&db->db_mtx); |
| return (B_FALSE); |
| } |
| |
| void |
| dmu_buf_will_not_fill(dmu_buf_t *db_fake, dmu_tx_t *tx) |
| { |
| dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; |
| |
| db->db_state = DB_NOFILL; |
| |
| dmu_buf_will_fill(db_fake, tx); |
| } |
| |
| void |
| dmu_buf_will_fill(dmu_buf_t *db_fake, dmu_tx_t *tx) |
| { |
| dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; |
| |
| ASSERT(db->db_blkid != DMU_BONUS_BLKID); |
| ASSERT(tx->tx_txg != 0); |
| ASSERT(db->db_level == 0); |
| ASSERT(!zfs_refcount_is_zero(&db->db_holds)); |
| |
| ASSERT(db->db.db_object != DMU_META_DNODE_OBJECT || |
| dmu_tx_private_ok(tx)); |
| |
| dbuf_noread(db); |
| (void) dbuf_dirty(db, tx); |
| } |
| |
| /* |
| * This function is effectively the same as dmu_buf_will_dirty(), but |
| * indicates the caller expects raw encrypted data in the db, and provides |
| * the crypt params (byteorder, salt, iv, mac) which should be stored in the |
| * blkptr_t when this dbuf is written. This is only used for blocks of |
| * dnodes, during raw receive. |
| */ |
| void |
| dmu_buf_set_crypt_params(dmu_buf_t *db_fake, boolean_t byteorder, |
| const uint8_t *salt, const uint8_t *iv, const uint8_t *mac, dmu_tx_t *tx) |
| { |
| dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; |
| dbuf_dirty_record_t *dr; |
| |
| /* |
| * dr_has_raw_params is only processed for blocks of dnodes |
| * (see dbuf_sync_dnode_leaf_crypt()). |
| */ |
| ASSERT3U(db->db.db_object, ==, DMU_META_DNODE_OBJECT); |
| ASSERT3U(db->db_level, ==, 0); |
| ASSERT(db->db_objset->os_raw_receive); |
| |
| dmu_buf_will_dirty_impl(db_fake, |
| DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH | DB_RF_NO_DECRYPT, tx); |
| |
| dr = db->db_last_dirty; |
| while (dr != NULL && dr->dr_txg > tx->tx_txg) |
| dr = dr->dr_next; |
| |
| ASSERT3P(dr, !=, NULL); |
| ASSERT3U(dr->dr_txg, ==, tx->tx_txg); |
| |
| dr->dt.dl.dr_has_raw_params = B_TRUE; |
| dr->dt.dl.dr_byteorder = byteorder; |
| bcopy(salt, dr->dt.dl.dr_salt, ZIO_DATA_SALT_LEN); |
| bcopy(iv, dr->dt.dl.dr_iv, ZIO_DATA_IV_LEN); |
| bcopy(mac, dr->dt.dl.dr_mac, ZIO_DATA_MAC_LEN); |
| } |
| |
| #pragma weak dmu_buf_fill_done = dbuf_fill_done |
| /* ARGSUSED */ |
| void |
| dbuf_fill_done(dmu_buf_impl_t *db, dmu_tx_t *tx) |
| { |
| mutex_enter(&db->db_mtx); |
| DBUF_VERIFY(db); |
| |
| if (db->db_state == DB_FILL) { |
| if (db->db_level == 0 && db->db_freed_in_flight) { |
| ASSERT(db->db_blkid != DMU_BONUS_BLKID); |
| /* we were freed while filling */ |
| /* XXX dbuf_undirty? */ |
| bzero(db->db.db_data, db->db.db_size); |
| db->db_freed_in_flight = FALSE; |
| } |
| db->db_state = DB_CACHED; |
| cv_broadcast(&db->db_changed); |
| } |
| mutex_exit(&db->db_mtx); |
| } |
| |
| 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) |
| { |
| dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbuf; |
| struct dirty_leaf *dl; |
| dmu_object_type_t type; |
| |
| if (etype == BP_EMBEDDED_TYPE_DATA) { |
| ASSERT(spa_feature_is_active(dmu_objset_spa(db->db_objset), |
| SPA_FEATURE_EMBEDDED_DATA)); |
| } |
| |
| DB_DNODE_ENTER(db); |
| type = DB_DNODE(db)->dn_type; |
| DB_DNODE_EXIT(db); |
| |
| ASSERT0(db->db_level); |
| ASSERT(db->db_blkid != DMU_BONUS_BLKID); |
| |
| dmu_buf_will_not_fill(dbuf, tx); |
| |
| ASSERT3U(db->db_last_dirty->dr_txg, ==, tx->tx_txg); |
| dl = &db->db_last_dirty->dt.dl; |
| encode_embedded_bp_compressed(&dl->dr_overridden_by, |
| data, comp, uncompressed_size, compressed_size); |
| BPE_SET_ETYPE(&dl->dr_overridden_by, etype); |
| BP_SET_TYPE(&dl->dr_overridden_by, type); |
| BP_SET_LEVEL(&dl->dr_overridden_by, 0); |
| BP_SET_BYTEORDER(&dl->dr_overridden_by, byteorder); |
| |
| dl->dr_override_state = DR_OVERRIDDEN; |
| dl->dr_overridden_by.blk_birth = db->db_last_dirty->dr_txg; |
| } |
| |
| /* |
| * Directly assign a provided arc buf to a given dbuf if it's not referenced |
| * by anybody except our caller. Otherwise copy arcbuf's contents to dbuf. |
| */ |
| void |
| dbuf_assign_arcbuf(dmu_buf_impl_t *db, arc_buf_t *buf, dmu_tx_t *tx) |
| { |
| ASSERT(!zfs_refcount_is_zero(&db->db_holds)); |
| ASSERT(db->db_blkid != DMU_BONUS_BLKID); |
| ASSERT(db->db_level == 0); |
| ASSERT3U(dbuf_is_metadata(db), ==, arc_is_metadata(buf)); |
| ASSERT(buf != NULL); |
| ASSERT3U(arc_buf_lsize(buf), ==, db->db.db_size); |
| ASSERT(tx->tx_txg != 0); |
| |
| arc_return_buf(buf, db); |
| ASSERT(arc_released(buf)); |
| |
| mutex_enter(&db->db_mtx); |
| |
| while (db->db_state == DB_READ || db->db_state == DB_FILL) |
| cv_wait(&db->db_changed, &db->db_mtx); |
| |
| ASSERT(db->db_state == DB_CACHED || db->db_state == DB_UNCACHED); |
| |
| if (db->db_state == DB_CACHED && |
| zfs_refcount_count(&db->db_holds) - 1 > db->db_dirtycnt) { |
| /* |
| * In practice, we will never have a case where we have an |
| * encrypted arc buffer while additional holds exist on the |
| * dbuf. We don't handle this here so we simply assert that |
| * fact instead. |
| */ |
| ASSERT(!arc_is_encrypted(buf)); |
| mutex_exit(&db->db_mtx); |
| (void) dbuf_dirty(db, tx); |
| bcopy(buf->b_data, db->db.db_data, db->db.db_size); |
| arc_buf_destroy(buf, db); |
| xuio_stat_wbuf_copied(); |
| return; |
| } |
| |
| xuio_stat_wbuf_nocopy(); |
| if (db->db_state == DB_CACHED) { |
| dbuf_dirty_record_t *dr = db->db_last_dirty; |
| |
| ASSERT(db->db_buf != NULL); |
| if (dr != NULL && dr->dr_txg == tx->tx_txg) { |
| ASSERT(dr->dt.dl.dr_data == db->db_buf); |
| |
| if (!arc_released(db->db_buf)) { |
| ASSERT(dr->dt.dl.dr_override_state == |
| DR_OVERRIDDEN); |
| arc_release(db->db_buf, db); |
| } |
| dr->dt.dl.dr_data = buf; |
| arc_buf_destroy(db->db_buf, db); |
| } else if (dr == NULL || dr->dt.dl.dr_data != db->db_buf) { |
| arc_release(db->db_buf, db); |
| arc_buf_destroy(db->db_buf, db); |
| } |
| db->db_buf = NULL; |
| } |
| ASSERT(db->db_buf == NULL); |
| dbuf_set_data(db, buf); |
| db->db_state = DB_FILL; |
| mutex_exit(&db->db_mtx); |
| (void) dbuf_dirty(db, tx); |
| dmu_buf_fill_done(&db->db, tx); |
| } |
| |
| void |
| dbuf_destroy(dmu_buf_impl_t *db) |
| { |
| dnode_t *dn; |
| dmu_buf_impl_t *parent = db->db_parent; |
| dmu_buf_impl_t *dndb; |
| |
| ASSERT(MUTEX_HELD(&db->db_mtx)); |
| ASSERT(zfs_refcount_is_zero(&db->db_holds)); |
| |
| if (db->db_buf != NULL) { |
| arc_buf_destroy(db->db_buf, db); |
| db->db_buf = NULL; |
| } |
| |
| if (db->db_blkid == DMU_BONUS_BLKID) { |
| int slots = DB_DNODE(db)->dn_num_slots; |
| int bonuslen = DN_SLOTS_TO_BONUSLEN(slots); |
| if (db->db.db_data != NULL) { |
| kmem_free(db->db.db_data, bonuslen); |
| arc_space_return(bonuslen, ARC_SPACE_BONUS); |
| db->db_state = DB_UNCACHED; |
| } |
| } |
| |
| dbuf_clear_data(db); |
| |
| if (multilist_link_active(&db->db_cache_link)) { |
| ASSERT(db->db_caching_status == DB_DBUF_CACHE || |
| db->db_caching_status == DB_DBUF_METADATA_CACHE); |
| |
| multilist_remove(dbuf_caches[db->db_caching_status].cache, db); |
| (void) zfs_refcount_remove_many( |
| &dbuf_caches[db->db_caching_status].size, |
| db->db.db_size, db); |
| |
| if (db->db_caching_status == DB_DBUF_METADATA_CACHE) { |
| DBUF_STAT_BUMPDOWN(metadata_cache_count); |
| } else { |
| DBUF_STAT_BUMPDOWN(cache_levels[db->db_level]); |
| DBUF_STAT_BUMPDOWN(cache_count); |
| DBUF_STAT_DECR(cache_levels_bytes[db->db_level], |
| db->db.db_size); |
| } |
| db->db_caching_status = DB_NO_CACHE; |
| } |
| |
| ASSERT(db->db_state == DB_UNCACHED || db->db_state == DB_NOFILL); |
| ASSERT(db->db_data_pending == NULL); |
| |
| db->db_state = DB_EVICTING; |
| db->db_blkptr = NULL; |
| |
| /* |
| * Now that db_state is DB_EVICTING, nobody else can find this via |
| * the hash table. We can now drop db_mtx, which allows us to |
| * acquire the dn_dbufs_mtx. |
| */ |
| mutex_exit(&db->db_mtx); |
| |
| DB_DNODE_ENTER(db); |
| dn = DB_DNODE(db); |
| dndb = dn->dn_dbuf; |
| if (db->db_blkid != DMU_BONUS_BLKID) { |
| boolean_t needlock = !MUTEX_HELD(&dn->dn_dbufs_mtx); |
| if (needlock) |
| mutex_enter_nested(&dn->dn_dbufs_mtx, |
| NESTED_SINGLE); |
| avl_remove(&dn->dn_dbufs, db); |
| atomic_dec_32(&dn->dn_dbufs_count); |
| membar_producer(); |
| DB_DNODE_EXIT(db); |
| if (needlock) |
| mutex_exit(&dn->dn_dbufs_mtx); |
| /* |
| * Decrementing the dbuf count means that the hold corresponding |
| * to the removed dbuf is no longer discounted in dnode_move(), |
| * so the dnode cannot be moved until after we release the hold. |
| * The membar_producer() ensures visibility of the decremented |
| * value in dnode_move(), since DB_DNODE_EXIT doesn't actually |
| * release any lock. |
| */ |
| mutex_enter(&dn->dn_mtx); |
| dnode_rele_and_unlock(dn, db, B_TRUE); |
| db->db_dnode_handle = NULL; |
| |
| dbuf_hash_remove(db); |
| } else { |
| DB_DNODE_EXIT(db); |
| } |
| |
| ASSERT(zfs_refcount_is_zero(&db->db_holds)); |
| |
| db->db_parent = NULL; |
| |
| ASSERT(db->db_buf == NULL); |
| ASSERT(db->db.db_data == NULL); |
| ASSERT(db->db_hash_next == NULL); |
| ASSERT(db->db_blkptr == NULL); |
| ASSERT(db->db_data_pending == NULL); |
| ASSERT3U(db->db_caching_status, ==, DB_NO_CACHE); |
| ASSERT(!multilist_link_active(&db->db_cache_link)); |
| |
| kmem_cache_free(dbuf_kmem_cache, db); |
| arc_space_return(sizeof (dmu_buf_impl_t), ARC_SPACE_DBUF); |
| |
| /* |
| * If this dbuf is referenced from an indirect dbuf, |
| * decrement the ref count on the indirect dbuf. |
| */ |
| if (parent && parent != dndb) { |
| mutex_enter(&parent->db_mtx); |
| dbuf_rele_and_unlock(parent, db, B_TRUE); |
| } |
| } |
| |
| /* |
| * Note: While bpp will always be updated if the function returns success, |
| * parentp will not be updated if the dnode does not have dn_dbuf filled in; |
| * this happens when the dnode is the meta-dnode, or {user|group|project}used |
| * object. |
| */ |
| __attribute__((always_inline)) |
| static inline int |
| dbuf_findbp(dnode_t *dn, int level, uint64_t blkid, int fail_sparse, |
| dmu_buf_impl_t **parentp, blkptr_t **bpp) |
| { |
| *parentp = NULL; |
| *bpp = NULL; |
| |
| ASSERT(blkid != DMU_BONUS_BLKID); |
| |
| if (blkid == DMU_SPILL_BLKID) { |
| mutex_enter(&dn->dn_mtx); |
| if (dn->dn_have_spill && |
| (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR)) |
| *bpp = DN_SPILL_BLKPTR(dn->dn_phys); |
| else |
| *bpp = NULL; |
| dbuf_add_ref(dn->dn_dbuf, NULL); |
| *parentp = dn->dn_dbuf; |
| mutex_exit(&dn->dn_mtx); |
| return (0); |
| } |
| |
| int nlevels = |
| (dn->dn_phys->dn_nlevels == 0) ? 1 : dn->dn_phys->dn_nlevels; |
| int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; |
| |
| ASSERT3U(level * epbs, <, 64); |
| ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock)); |
| /* |
| * This assertion shouldn't trip as long as the max indirect block size |
| * is less than 1M. The reason for this is that up to that point, |
| * the number of levels required to address an entire object with blocks |
| * of size SPA_MINBLOCKSIZE satisfies nlevels * epbs + 1 <= 64. In |
| * other words, if N * epbs + 1 > 64, then if (N-1) * epbs + 1 > 55 |
| * (i.e. we can address the entire object), objects will all use at most |
| * N-1 levels and the assertion won't overflow. However, once epbs is |
| * 13, 4 * 13 + 1 = 53, but 5 * 13 + 1 = 66. Then, 4 levels will not be |
| * enough to address an entire object, so objects will have 5 levels, |
| * but then this assertion will overflow. |
| * |
| * All this is to say that if we ever increase DN_MAX_INDBLKSHIFT, we |
| * need to redo this logic to handle overflows. |
| */ |
| ASSERT(level >= nlevels || |
| ((nlevels - level - 1) * epbs) + |
| highbit64(dn->dn_phys->dn_nblkptr) <= 64); |
| if (level >= nlevels || |
| blkid >= ((uint64_t)dn->dn_phys->dn_nblkptr << |
| ((nlevels - level - 1) * epbs)) || |
| (fail_sparse && |
| blkid > (dn->dn_phys->dn_maxblkid >> (level * epbs)))) { |
| /* the buffer has no parent yet */ |
| return (SET_ERROR(ENOENT)); |
| } else if (level < nlevels-1) { |
| /* this block is referenced from an indirect block */ |
| int err; |
| dbuf_hold_arg_t *dh = dbuf_hold_arg_create(dn, level + 1, |
| blkid >> epbs, fail_sparse, FALSE, NULL, parentp); |
| err = dbuf_hold_impl_arg(dh); |
| dbuf_hold_arg_destroy(dh); |
| if (err) |
| return (err); |
| err = dbuf_read(*parentp, NULL, |
| (DB_RF_HAVESTRUCT | DB_RF_NOPREFETCH | DB_RF_CANFAIL)); |
| if (err) { |
| dbuf_rele(*parentp, NULL); |
| *parentp = NULL; |
| return (err); |
| } |
| *bpp = ((blkptr_t *)(*parentp)->db.db_data) + |
| (blkid & ((1ULL << epbs) - 1)); |
| if (blkid > (dn->dn_phys->dn_maxblkid >> (level * epbs))) |
| ASSERT(BP_IS_HOLE(*bpp)); |
| return (0); |
| } else { |
| /* the block is referenced from the dnode */ |
| ASSERT3U(level, ==, nlevels-1); |
| ASSERT(dn->dn_phys->dn_nblkptr == 0 || |
| blkid < dn->dn_phys->dn_nblkptr); |
| if (dn->dn_dbuf) { |
| dbuf_add_ref(dn->dn_dbuf, NULL); |
| *parentp = dn->dn_dbuf; |
| } |
| *bpp = &dn->dn_phys->dn_blkptr[blkid]; |
| return (0); |
| } |
| } |
| |
| static dmu_buf_impl_t * |
| dbuf_create(dnode_t *dn, uint8_t level, uint64_t blkid, |
| dmu_buf_impl_t *parent, blkptr_t *blkptr) |
| { |
| objset_t *os = dn->dn_objset; |
| dmu_buf_impl_t *db, *odb; |
| |
| ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock)); |
| ASSERT(dn->dn_type != DMU_OT_NONE); |
| |
| db = kmem_cache_alloc(dbuf_kmem_cache, KM_SLEEP); |
| |
| db->db_objset = os; |
| db->db.db_object = dn->dn_object; |
| db->db_level = level; |
| db->db_blkid = blkid; |
| db->db_last_dirty = NULL; |
| db->db_dirtycnt = 0; |
| db->db_dnode_handle = dn->dn_handle; |
| db->db_parent = parent; |
| db->db_blkptr = blkptr; |
| |
| db->db_user = NULL; |
| db->db_user_immediate_evict = FALSE; |
| db->db_freed_in_flight = FALSE; |
| db->db_pending_evict = FALSE; |
| |
| if (blkid == DMU_BONUS_BLKID) { |
| ASSERT3P(parent, ==, dn->dn_dbuf); |
| db->db.db_size = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots) - |
| (dn->dn_nblkptr-1) * sizeof (blkptr_t); |
| ASSERT3U(db->db.db_size, >=, dn->dn_bonuslen); |
| db->db.db_offset = DMU_BONUS_BLKID; |
| db->db_state = DB_UNCACHED; |
| db->db_caching_status = DB_NO_CACHE; |
| /* the bonus dbuf is not placed in the hash table */ |
| arc_space_consume(sizeof (dmu_buf_impl_t), ARC_SPACE_DBUF); |
| return (db); |
| } else if (blkid == DMU_SPILL_BLKID) { |
| db->db.db_size = (blkptr != NULL) ? |
| BP_GET_LSIZE(blkptr) : SPA_MINBLOCKSIZE; |
| db->db.db_offset = 0; |
| } else { |
| int blocksize = |
| db->db_level ? 1 << dn->dn_indblkshift : dn->dn_datablksz; |
| db->db.db_size = blocksize; |
| db->db.db_offset = db->db_blkid * blocksize; |
| } |
| |
| /* |
| * Hold the dn_dbufs_mtx while we get the new dbuf |
| * in the hash table *and* added to the dbufs list. |
| * This prevents a possible deadlock with someone |
| * trying to look up this dbuf before it's added to the |
| * dn_dbufs list. |
| */ |
| mutex_enter(&dn->dn_dbufs_mtx); |
| db->db_state = DB_EVICTING; |
| if ((odb = dbuf_hash_insert(db)) != NULL) { |
| /* someone else inserted it first */ |
| kmem_cache_free(dbuf_kmem_cache, db); |
| mutex_exit(&dn->dn_dbufs_mtx); |
| DBUF_STAT_BUMP(hash_insert_race); |
| return (odb); |
| } |
| avl_add(&dn->dn_dbufs, db); |
| |
| db->db_state = DB_UNCACHED; |
| db->db_caching_status = DB_NO_CACHE; |
| mutex_exit(&dn->dn_dbufs_mtx); |
| arc_space_consume(sizeof (dmu_buf_impl_t), ARC_SPACE_DBUF); |
| |
| if (parent && parent != dn->dn_dbuf) |
| dbuf_add_ref(parent, db); |
| |
| ASSERT(dn->dn_object == DMU_META_DNODE_OBJECT || |
| zfs_refcount_count(&dn->dn_holds) > 0); |
| (void) zfs_refcount_add(&dn->dn_holds, db); |
| atomic_inc_32(&dn->dn_dbufs_count); |
| |
| dprintf_dbuf(db, "db=%p\n", db); |
| |
| return (db); |
| } |
| |
| typedef struct dbuf_prefetch_arg { |
| spa_t *dpa_spa; /* The spa to issue the prefetch in. */ |
| zbookmark_phys_t dpa_zb; /* The target block to prefetch. */ |
| int dpa_epbs; /* Entries (blkptr_t's) Per Block Shift. */ |
| int dpa_curlevel; /* The current level that we're reading */ |
| dnode_t *dpa_dnode; /* The dnode associated with the prefetch */ |
| zio_priority_t dpa_prio; /* The priority I/Os should be issued at. */ |
| zio_t *dpa_zio; /* The parent zio_t for all prefetches. */ |
| arc_flags_t dpa_aflags; /* Flags to pass to the final prefetch. */ |
| } dbuf_prefetch_arg_t; |
| |
| /* |
| * Actually issue the prefetch read for the block given. |
| */ |
| static void |
| dbuf_issue_final_prefetch(dbuf_prefetch_arg_t *dpa, blkptr_t *bp) |
| { |
| if (BP_IS_HOLE(bp) || BP_IS_EMBEDDED(bp)) |
| return; |
| |
| int zio_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE; |
| arc_flags_t aflags = |
| dpa->dpa_aflags | ARC_FLAG_NOWAIT | ARC_FLAG_PREFETCH; |
| |
| /* dnodes are always read as raw and then converted later */ |
| if (BP_GET_TYPE(bp) == DMU_OT_DNODE && BP_IS_PROTECTED(bp) && |
| dpa->dpa_curlevel == 0) |
| zio_flags |= ZIO_FLAG_RAW; |
| |
| ASSERT3U(dpa->dpa_curlevel, ==, BP_GET_LEVEL(bp)); |
| ASSERT3U(dpa->dpa_curlevel, ==, dpa->dpa_zb.zb_level); |
| ASSERT(dpa->dpa_zio != NULL); |
| (void) arc_read(dpa->dpa_zio, dpa->dpa_spa, bp, NULL, NULL, |
| dpa->dpa_prio, zio_flags, &aflags, &dpa->dpa_zb); |
| } |
| |
| /* |
| * Called when an indirect block above our prefetch target is read in. This |
| * will either read in the next indirect block down the tree or issue the actual |
| * prefetch if the next block down is our target. |
| */ |
| static void |
| dbuf_prefetch_indirect_done(zio_t *zio, const zbookmark_phys_t *zb, |
| const blkptr_t *iobp, arc_buf_t *abuf, void *private) |
| { |
| dbuf_prefetch_arg_t *dpa = private; |
| |
| ASSERT3S(dpa->dpa_zb.zb_level, <, dpa->dpa_curlevel); |
| ASSERT3S(dpa->dpa_curlevel, >, 0); |
| |
| if (abuf == NULL) { |
| ASSERT(zio == NULL || zio->io_error != 0); |
| kmem_free(dpa, sizeof (*dpa)); |
| return; |
| } |
| ASSERT(zio == NULL || zio->io_error == 0); |
| |
| /* |
| * The dpa_dnode is only valid if we are called with a NULL |
| * zio. This indicates that the arc_read() returned without |
| * first calling zio_read() to issue a physical read. Once |
| * a physical read is made the dpa_dnode must be invalidated |
| * as the locks guarding it may have been dropped. If the |
| * dpa_dnode is still valid, then we want to add it to the dbuf |
| * cache. To do so, we must hold the dbuf associated with the block |
| * we just prefetched, read its contents so that we associate it |
| * with an arc_buf_t, and then release it. |
| */ |
| if (zio != NULL) { |
| ASSERT3S(BP_GET_LEVEL(zio->io_bp), ==, dpa->dpa_curlevel); |
| if (zio->io_flags & ZIO_FLAG_RAW_COMPRESS) { |
| ASSERT3U(BP_GET_PSIZE(zio->io_bp), ==, zio->io_size); |
| } else { |
| ASSERT3U(BP_GET_LSIZE(zio->io_bp), ==, zio->io_size); |
| } |
| ASSERT3P(zio->io_spa, ==, dpa->dpa_spa); |
| |
| dpa->dpa_dnode = NULL; |
| } else if (dpa->dpa_dnode != NULL) { |
| uint64_t curblkid = dpa->dpa_zb.zb_blkid >> |
| (dpa->dpa_epbs * (dpa->dpa_curlevel - |
| dpa->dpa_zb.zb_level)); |
| dmu_buf_impl_t *db = dbuf_hold_level(dpa->dpa_dnode, |
| dpa->dpa_curlevel, curblkid, FTAG); |
| if (db == NULL) { |
| kmem_free(dpa, sizeof (*dpa)); |
| arc_buf_destroy(abuf, private); |
| return; |
| } |
| |
| (void) dbuf_read(db, NULL, |
| DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH | DB_RF_HAVESTRUCT); |
| dbuf_rele(db, FTAG); |
| } |
| |
| dpa->dpa_curlevel--; |
| uint64_t nextblkid = dpa->dpa_zb.zb_blkid >> |
| (dpa->dpa_epbs * (dpa->dpa_curlevel - dpa->dpa_zb.zb_level)); |
| blkptr_t *bp = ((blkptr_t *)abuf->b_data) + |
| P2PHASE(nextblkid, 1ULL << dpa->dpa_epbs); |
| |
| if (BP_IS_HOLE(bp)) { |
| kmem_free(dpa, sizeof (*dpa)); |
| } else if (dpa->dpa_curlevel == dpa->dpa_zb.zb_level) { |
| ASSERT3U(nextblkid, ==, dpa->dpa_zb.zb_blkid); |
| dbuf_issue_final_prefetch(dpa, bp); |
| kmem_free(dpa, sizeof (*dpa)); |
| } else { |
| arc_flags_t iter_aflags = ARC_FLAG_NOWAIT; |
| zbookmark_phys_t zb; |
| |
| /* flag if L2ARC eligible, l2arc_noprefetch then decides */ |
| if (dpa->dpa_aflags & ARC_FLAG_L2CACHE) |
| iter_aflags |= ARC_FLAG_L2CACHE; |
| |
| ASSERT3U(dpa->dpa_curlevel, ==, BP_GET_LEVEL(bp)); |
| |
| SET_BOOKMARK(&zb, dpa->dpa_zb.zb_objset, |
| dpa->dpa_zb.zb_object, dpa->dpa_curlevel, nextblkid); |
| |
| (void) arc_read(dpa->dpa_zio, dpa->dpa_spa, |
| bp, dbuf_prefetch_indirect_done, dpa, dpa->dpa_prio, |
| ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, |
| &iter_aflags, &zb); |
| } |
| |
| arc_buf_destroy(abuf, private); |
| } |
| |
| /* |
| * Issue prefetch reads for the given block on the given level. If the indirect |
| * blocks above that block are not in memory, we will read them in |
| * asynchronously. As a result, this call never blocks waiting for a read to |
| * complete. Note that the prefetch might fail if the dataset is encrypted and |
| * the encryption key is unmapped before the IO completes. |
| */ |
| void |
| dbuf_prefetch(dnode_t *dn, int64_t level, uint64_t blkid, zio_priority_t prio, |
| arc_flags_t aflags) |
| { |
| blkptr_t bp; |
| int epbs, nlevels, curlevel; |
| uint64_t curblkid; |
| |
| ASSERT(blkid != DMU_BONUS_BLKID); |
| ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock)); |
| |
| if (blkid > dn->dn_maxblkid) |
| return; |
| |
| if (dnode_block_freed(dn, blkid)) |
| return; |
| |
| /* |
| * This dnode hasn't been written to disk yet, so there's nothing to |
| * prefetch. |
| */ |
| nlevels = dn->dn_phys->dn_nlevels; |
| if (level >= nlevels || dn->dn_phys->dn_nblkptr == 0) |
| return; |
| |
| epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; |
| if (dn->dn_phys->dn_maxblkid < blkid << (epbs * level)) |
| return; |
| |
| dmu_buf_impl_t *db = dbuf_find(dn->dn_objset, dn->dn_object, |
| level, blkid); |
| if (db != NULL) { |
| mutex_exit(&db->db_mtx); |
| /* |
| * This dbuf already exists. It is either CACHED, or |
| * (we assume) about to be read or filled. |
| */ |
| return; |
| } |
| |
| /* |
| * Find the closest ancestor (indirect block) of the target block |
| * that is present in the cache. In this indirect block, we will |
| * find the bp that is at curlevel, curblkid. |
| */ |
| curlevel = level; |
| curblkid = blkid; |
| while (curlevel < nlevels - 1) { |
| int parent_level = curlevel + 1; |
| uint64_t parent_blkid = curblkid >> epbs; |
| dmu_buf_impl_t *db; |
| |
| if (dbuf_hold_impl(dn, parent_level, parent_blkid, |
| FALSE, TRUE, FTAG, &db) == 0) { |
| blkptr_t *bpp = db->db_buf->b_data; |
| bp = bpp[P2PHASE(curblkid, 1 << epbs)]; |
| dbuf_rele(db, FTAG); |
| break; |
| } |
| |
| curlevel = parent_level; |
| curblkid = parent_blkid; |
| } |
| |
| if (curlevel == nlevels - 1) { |
| /* No cached indirect blocks found. */ |
| ASSERT3U(curblkid, <, dn->dn_phys->dn_nblkptr); |
| bp = dn->dn_phys->dn_blkptr[curblkid]; |
| } |
| if (BP_IS_HOLE(&bp)) |
| return; |
| |
| ASSERT3U(curlevel, ==, BP_GET_LEVEL(&bp)); |
| |
| zio_t *pio = zio_root(dmu_objset_spa(dn->dn_objset), NULL, NULL, |
| ZIO_FLAG_CANFAIL); |
| |
| dbuf_prefetch_arg_t *dpa = kmem_zalloc(sizeof (*dpa), KM_SLEEP); |
| dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset; |
| SET_BOOKMARK(&dpa->dpa_zb, ds != NULL ? ds->ds_object : DMU_META_OBJSET, |
| dn->dn_object, level, blkid); |
| dpa->dpa_curlevel = curlevel; |
| dpa->dpa_prio = prio; |
| dpa->dpa_aflags = aflags; |
| dpa->dpa_spa = dn->dn_objset->os_spa; |
| dpa->dpa_dnode = dn; |
| dpa->dpa_epbs = epbs; |
| dpa->dpa_zio = pio; |
| |
| /* flag if L2ARC eligible, l2arc_noprefetch then decides */ |
| if (DNODE_LEVEL_IS_L2CACHEABLE(dn, level)) |
| dpa->dpa_aflags |= ARC_FLAG_L2CACHE; |
| |
| /* |
| * If we have the indirect just above us, no need to do the asynchronous |
| * prefetch chain; we'll just run the last step ourselves. If we're at |
| * a higher level, though, we want to issue the prefetches for all the |
| * indirect blocks asynchronously, so we can go on with whatever we were |
| * doing. |
| */ |
| if (curlevel == level) { |
| ASSERT3U(curblkid, ==, blkid); |
| dbuf_issue_final_prefetch(dpa, &bp); |
| kmem_free(dpa, sizeof (*dpa)); |
| } else { |
| arc_flags_t iter_aflags = ARC_FLAG_NOWAIT; |
| zbookmark_phys_t zb; |
| |
| /* flag if L2ARC eligible, l2arc_noprefetch then decides */ |
| if (DNODE_LEVEL_IS_L2CACHEABLE(dn, level)) |
| iter_aflags |= ARC_FLAG_L2CACHE; |
| |
| SET_BOOKMARK(&zb, ds != NULL ? ds->ds_object : DMU_META_OBJSET, |
| dn->dn_object, curlevel, curblkid); |
| (void) arc_read(dpa->dpa_zio, dpa->dpa_spa, |
| &bp, dbuf_prefetch_indirect_done, dpa, prio, |
| ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, |
| &iter_aflags, &zb); |
| } |
| /* |
| * We use pio here instead of dpa_zio since it's possible that |
| * dpa may have already been freed. |
| */ |
| zio_nowait(pio); |
| } |
| |
| #define DBUF_HOLD_IMPL_MAX_DEPTH 20 |
| |
| /* |
| * Helper function for dbuf_hold_impl_arg() to copy a buffer. Handles |
| * the case of encrypted, compressed and uncompressed buffers by |
| * allocating the new buffer, respectively, with arc_alloc_raw_buf(), |
| * arc_alloc_compressed_buf() or arc_alloc_buf().* |
| * |
| * NOTE: Declared noinline to avoid stack bloat in dbuf_hold_impl_arg(). |
| */ |
| noinline static void |
| dbuf_hold_copy(struct dbuf_hold_arg *dh) |
| { |
| dnode_t *dn = dh->dh_dn; |
| dmu_buf_impl_t *db = dh->dh_db; |
| dbuf_dirty_record_t *dr = dh->dh_dr; |
| arc_buf_t *data = dr->dt.dl.dr_data; |
| |
| enum zio_compress compress_type = arc_get_compression(data); |
| |
| if (arc_is_encrypted(data)) { |
| boolean_t byteorder; |
| uint8_t salt[ZIO_DATA_SALT_LEN]; |
| uint8_t iv[ZIO_DATA_IV_LEN]; |
| uint8_t mac[ZIO_DATA_MAC_LEN]; |
| |
| arc_get_raw_params(data, &byteorder, salt, iv, mac); |
| dbuf_set_data(db, arc_alloc_raw_buf(dn->dn_objset->os_spa, db, |
| dmu_objset_id(dn->dn_objset), byteorder, salt, iv, mac, |
| dn->dn_type, arc_buf_size(data), arc_buf_lsize(data), |
| compress_type)); |
| } else if (compress_type != ZIO_COMPRESS_OFF) { |
| dbuf_set_data(db, arc_alloc_compressed_buf( |
| dn->dn_objset->os_spa, db, arc_buf_size(data), |
| arc_buf_lsize(data), compress_type)); |
| } else { |
| dbuf_set_data(db, arc_alloc_buf(dn->dn_objset->os_spa, db, |
| DBUF_GET_BUFC_TYPE(db), db->db.db_size)); |
| } |
| |
| bcopy(data->b_data, db->db.db_data, arc_buf_size(data)); |
| } |
| |
| /* |
| * Returns with db_holds incremented, and db_mtx not held. |
| * Note: dn_struct_rwlock must be held. |
| */ |
| static int |
| dbuf_hold_impl_arg(struct dbuf_hold_arg *dh) |
| { |
| dh->dh_parent = NULL; |
| |
| ASSERT(dh->dh_blkid != DMU_BONUS_BLKID); |
| ASSERT(RW_LOCK_HELD(&dh->dh_dn->dn_struct_rwlock)); |
| ASSERT3U(dh->dh_dn->dn_nlevels, >, dh->dh_level); |
| |
| *(dh->dh_dbp) = NULL; |
| |
| /* dbuf_find() returns with db_mtx held */ |
| dh->dh_db = dbuf_find(dh->dh_dn->dn_objset, dh->dh_dn->dn_object, |
| dh->dh_level, dh->dh_blkid); |
| |
| if (dh->dh_db == NULL) { |
| dh->dh_bp = NULL; |
| |
| if (dh->dh_fail_uncached) |
| return (SET_ERROR(ENOENT)); |
| |
| ASSERT3P(dh->dh_parent, ==, NULL); |
| dh->dh_err = dbuf_findbp(dh->dh_dn, dh->dh_level, dh->dh_blkid, |
| dh->dh_fail_sparse, &dh->dh_parent, &dh->dh_bp); |
| if (dh->dh_fail_sparse) { |
| if (dh->dh_err == 0 && |
| dh->dh_bp && BP_IS_HOLE(dh->dh_bp)) |
| dh->dh_err = SET_ERROR(ENOENT); |
| if (dh->dh_err) { |
| if (dh->dh_parent) |
| dbuf_rele(dh->dh_parent, NULL); |
| return (dh->dh_err); |
| } |
| } |
| if (dh->dh_err && dh->dh_err != ENOENT) |
| return (dh->dh_err); |
| dh->dh_db = dbuf_create(dh->dh_dn, dh->dh_level, dh->dh_blkid, |
| dh->dh_parent, dh->dh_bp); |
| } |
| |
| if (dh->dh_fail_uncached && dh->dh_db->db_state != DB_CACHED) { |
| mutex_exit(&dh->dh_db->db_mtx); |
| return (SET_ERROR(ENOENT)); |
| } |
| |
| if (dh->dh_db->db_buf != NULL) { |
| arc_buf_access(dh->dh_db->db_buf); |
| ASSERT3P(dh->dh_db->db.db_data, ==, dh->dh_db->db_buf->b_data); |
| } |
| |
| ASSERT(dh->dh_db->db_buf == NULL || arc_referenced(dh->dh_db->db_buf)); |
| |
| /* |
| * If this buffer is currently syncing out, and we are |
| * still referencing it from db_data, we need to make a copy |
| * of it in case we decide we want to dirty it again in this txg. |
| */ |
| if (dh->dh_db->db_level == 0 && |
| dh->dh_db->db_blkid != DMU_BONUS_BLKID && |
| dh->dh_dn->dn_object != DMU_META_DNODE_OBJECT && |
| dh->dh_db->db_state == DB_CACHED && dh->dh_db->db_data_pending) { |
| dh->dh_dr = dh->dh_db->db_data_pending; |
| if (dh->dh_dr->dt.dl.dr_data == dh->dh_db->db_buf) |
| dbuf_hold_copy(dh); |
| } |
| |
| if (multilist_link_active(&dh->dh_db->db_cache_link)) { |
| ASSERT(zfs_refcount_is_zero(&dh->dh_db->db_holds)); |
| ASSERT(dh->dh_db->db_caching_status == DB_DBUF_CACHE || |
| dh->dh_db->db_caching_status == DB_DBUF_METADATA_CACHE); |
| |
| multilist_remove( |
| dbuf_caches[dh->dh_db->db_caching_status].cache, |
| dh->dh_db); |
| (void) zfs_refcount_remove_many( |
| &dbuf_caches[dh->dh_db->db_caching_status].size, |
| dh->dh_db->db.db_size, dh->dh_db); |
| |
| if (dh->dh_db->db_caching_status == DB_DBUF_METADATA_CACHE) { |
| DBUF_STAT_BUMPDOWN(metadata_cache_count); |
| } else { |
| DBUF_STAT_BUMPDOWN(cache_levels[dh->dh_db->db_level]); |
| DBUF_STAT_BUMPDOWN(cache_count); |
| DBUF_STAT_DECR(cache_levels_bytes[dh->dh_db->db_level], |
| dh->dh_db->db.db_size); |
| } |
| dh->dh_db->db_caching_status = DB_NO_CACHE; |
| } |
| (void) zfs_refcount_add(&dh->dh_db->db_holds, dh->dh_tag); |
| DBUF_VERIFY(dh->dh_db); |
| mutex_exit(&dh->dh_db->db_mtx); |
| |
| /* NOTE: we can't rele the parent until after we drop the db_mtx */ |
| if (dh->dh_parent) |
| dbuf_rele(dh->dh_parent, NULL); |
| |
| ASSERT3P(DB_DNODE(dh->dh_db), ==, dh->dh_dn); |
| ASSERT3U(dh->dh_db->db_blkid, ==, dh->dh_blkid); |
| ASSERT3U(dh->dh_db->db_level, ==, dh->dh_level); |
| *(dh->dh_dbp) = dh->dh_db; |
| |
| return (0); |
| } |
| |
| /* |
| * dbuf_hold_impl_arg() is called recursively, via dbuf_findbp(). There can |
| * be as many recursive calls as there are levels of on-disk indirect blocks, |
| * but typically only 0-2 recursive calls. To minimize the stack frame size, |
| * the recursive function's arguments and "local variables" are allocated on |
| * the heap as the dbuf_hold_arg_t. |
| */ |
| int |
| dbuf_hold_impl(dnode_t *dn, uint8_t level, uint64_t blkid, |
| boolean_t fail_sparse, boolean_t fail_uncached, |
| void *tag, dmu_buf_impl_t **dbp) |
| { |
| dbuf_hold_arg_t *dh = dbuf_hold_arg_create(dn, level, blkid, |
| fail_sparse, fail_uncached, tag, dbp); |
| |
| int error = dbuf_hold_impl_arg(dh); |
| |
| dbuf_hold_arg_destroy(dh); |
| |
| return (error); |
| } |
| |
| static dbuf_hold_arg_t * |
| dbuf_hold_arg_create(dnode_t *dn, uint8_t level, uint64_t blkid, |
| boolean_t fail_sparse, boolean_t fail_uncached, |
| void *tag, dmu_buf_impl_t **dbp) |
| { |
| dbuf_hold_arg_t *dh = kmem_alloc(sizeof (*dh), KM_SLEEP); |
| dh->dh_dn = dn; |
| dh->dh_level = level; |
| dh->dh_blkid = blkid; |
| |
| dh->dh_fail_sparse = fail_sparse; |
| dh->dh_fail_uncached = fail_uncached; |
| |
| dh->dh_tag = tag; |
| dh->dh_dbp = dbp; |
| |
| dh->dh_db = NULL; |
| dh->dh_parent = NULL; |
| dh->dh_bp = NULL; |
| dh->dh_err = 0; |
| dh->dh_dr = NULL; |
| |
| return (dh); |
| } |
| |
| static void |
| dbuf_hold_arg_destroy(dbuf_hold_arg_t *dh) |
| { |
| kmem_free(dh, sizeof (*dh)); |
| } |
| |
| dmu_buf_impl_t * |
| dbuf_hold(dnode_t *dn, uint64_t blkid, void *tag) |
| { |
| return (dbuf_hold_level(dn, 0, blkid, tag)); |
| } |
| |
| dmu_buf_impl_t * |
| dbuf_hold_level(dnode_t *dn, int level, uint64_t blkid, void *tag) |
| { |
| dmu_buf_impl_t *db; |
| int err = dbuf_hold_impl(dn, level, blkid, FALSE, FALSE, tag, &db); |
| return (err ? NULL : db); |
| } |
| |
| void |
| dbuf_create_bonus(dnode_t *dn) |
| { |
| ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock)); |
| |
| ASSERT(dn->dn_bonus == NULL); |
| dn->dn_bonus = dbuf_create(dn, 0, DMU_BONUS_BLKID, dn->dn_dbuf, NULL); |
| } |
| |
| int |
| dbuf_spill_set_blksz(dmu_buf_t *db_fake, uint64_t blksz, dmu_tx_t *tx) |
| { |
| dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; |
| dnode_t *dn; |
| |
| if (db->db_blkid != DMU_SPILL_BLKID) |
| return (SET_ERROR(ENOTSUP)); |
| if (blksz == 0) |
| blksz = SPA_MINBLOCKSIZE; |
| ASSERT3U(blksz, <=, spa_maxblocksize(dmu_objset_spa(db->db_objset))); |
| blksz = P2ROUNDUP(blksz, SPA_MINBLOCKSIZE); |
| |
| DB_DNODE_ENTER(db); |
| dn = DB_DNODE(db); |
| rw_enter(&dn->dn_struct_rwlock, RW_WRITER); |
| dbuf_new_size(db, blksz, tx); |
| rw_exit(&dn->dn_struct_rwlock); |
| DB_DNODE_EXIT(db); |
| |
| return (0); |
| } |
| |
| void |
| dbuf_rm_spill(dnode_t *dn, dmu_tx_t *tx) |
| { |
| dbuf_free_range(dn, DMU_SPILL_BLKID, DMU_SPILL_BLKID, tx); |
| } |
| |
| #pragma weak dmu_buf_add_ref = dbuf_add_ref |
| void |
| dbuf_add_ref(dmu_buf_impl_t *db, void *tag) |
| { |
| int64_t holds = zfs_refcount_add(&db->db_holds, tag); |
| VERIFY3S(holds, >, 1); |
| } |
| |
| #pragma weak dmu_buf_try_add_ref = dbuf_try_add_ref |
| boolean_t |
| dbuf_try_add_ref(dmu_buf_t *db_fake, objset_t *os, uint64_t obj, uint64_t blkid, |
| void *tag) |
| { |
| dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; |
| dmu_buf_impl_t *found_db; |
| boolean_t result = B_FALSE; |
| |
| if (blkid == DMU_BONUS_BLKID) |
| found_db = dbuf_find_bonus(os, obj); |
| else |
| found_db = dbuf_find(os, obj, 0, blkid); |
| |
| if (found_db != NULL) { |
| if (db == found_db && dbuf_refcount(db) > db->db_dirtycnt) { |
| (void) zfs_refcount_add(&db->db_holds, tag); |
| result = B_TRUE; |
| } |
| mutex_exit(&found_db->db_mtx); |
| } |
| return (result); |
| } |
| |
| /* |
| * If you call dbuf_rele() you had better not be referencing the dnode handle |
| * unless you have some other direct or indirect hold on the dnode. (An indirect |
| * hold is a hold on one of the dnode's dbufs, including the bonus buffer.) |
| * Without that, the dbuf_rele() could lead to a dnode_rele() followed by the |
| * dnode's parent dbuf evicting its dnode handles. |
| */ |
| void |
| dbuf_rele(dmu_buf_impl_t *db, void *tag) |
| { |
| mutex_enter(&db->db_mtx); |
| dbuf_rele_and_unlock(db, tag, B_FALSE); |
| } |
| |
| void |
| dmu_buf_rele(dmu_buf_t *db, void *tag) |
| { |
| dbuf_rele((dmu_buf_impl_t *)db, tag); |
| } |
| |
| /* |
| * dbuf_rele() for an already-locked dbuf. This is necessary to allow |
| * db_dirtycnt and db_holds to be updated atomically. The 'evicting' |
| * argument should be set if we are already in the dbuf-evicting code |
| * path, in which case we don't want to recursively evict. This allows us to |
| * avoid deeply nested stacks that would have a call flow similar to this: |
| * |
| * dbuf_rele()-->dbuf_rele_and_unlock()-->dbuf_evict_notify() |
| * ^ | |
| * | | |
| * +-----dbuf_destroy()<--dbuf_evict_one()<--------+ |
| * |
| */ |
| void |
| dbuf_rele_and_unlock(dmu_buf_impl_t *db, void *tag, boolean_t evicting) |
| { |
| int64_t holds; |
| |
| ASSERT(MUTEX_HELD(&db->db_mtx)); |
| DBUF_VERIFY(db); |
| |
| /* |
| * Remove the reference to the dbuf before removing its hold on the |
| * dnode so we can guarantee in dnode_move() that a referenced bonus |
| * buffer has a corresponding dnode hold. |
| */ |
| holds = zfs_refcount_remove(&db->db_holds, tag); |
| ASSERT(holds >= 0); |
| |
| /* |
| * We can't freeze indirects if there is a possibility that they |
| * may be modified in the current syncing context. |
| */ |
| if (db->db_buf != NULL && |
| holds == (db->db_level == 0 ? db->db_dirtycnt : 0)) { |
| arc_buf_freeze(db->db_buf); |
| } |
| |
| if (holds == db->db_dirtycnt && |
| db->db_level == 0 && db->db_user_immediate_evict) |
| dbuf_evict_user(db); |
| |
| if (holds == 0) { |
| if (db->db_blkid == DMU_BONUS_BLKID) { |
| dnode_t *dn; |
| boolean_t evict_dbuf = db->db_pending_evict; |
| |
| /* |
| * If the dnode moves here, we cannot cross this |
| * barrier until the move completes. |
| */ |
| DB_DNODE_ENTER(db); |
| |
| dn = DB_DNODE(db); |
| atomic_dec_32(&dn->dn_dbufs_count); |
| |
| /* |
| * Decrementing the dbuf count means that the bonus |
| * buffer's dnode hold is no longer discounted in |
| * dnode_move(). The dnode cannot move until after |
| * the dnode_rele() below. |
| */ |
| DB_DNODE_EXIT(db); |
| |
| /* |
| * Do not reference db after its lock is dropped. |
| * Another thread may evict it. |
| */ |
| mutex_exit(&db->db_mtx); |
| |
| if (evict_dbuf) |
| dnode_evict_bonus(dn); |
| |
| dnode_rele(dn, db); |
| } else if (db->db_buf == NULL) { |
| /* |
| * This is a special case: we never associated this |
| * dbuf with any data allocated from the ARC. |
| */ |
| ASSERT(db->db_state == DB_UNCACHED || |
| db->db_state == DB_NOFILL); |
| dbuf_destroy(db); |
| } else if (arc_released(db->db_buf)) { |
| /* |
| * This dbuf has anonymous data associated with it. |
| */ |
| dbuf_destroy(db); |
| } else { |
| boolean_t do_arc_evict = B_FALSE; |
| blkptr_t bp; |
| spa_t *spa = dmu_objset_spa(db->db_objset); |
| |
| if (!DBUF_IS_CACHEABLE(db) && |
| db->db_blkptr != NULL && |
| !BP_IS_HOLE(db->db_blkptr) && |
| !BP_IS_EMBEDDED(db->db_blkptr)) { |
| do_arc_evict = B_TRUE; |
| bp = *db->db_blkptr; |
| } |
| |
| if (!DBUF_IS_CACHEABLE(db) || |
| db->db_pending_evict) { |
| dbuf_destroy(db); |
| } else if (!multilist_link_active(&db->db_cache_link)) { |
| ASSERT3U(db->db_caching_status, ==, |
| DB_NO_CACHE); |
| |
| dbuf_cached_state_t dcs = |
| dbuf_include_in_metadata_cache(db) ? |
| DB_DBUF_METADATA_CACHE : DB_DBUF_CACHE; |
| db->db_caching_status = dcs; |
| |
| multilist_insert(dbuf_caches[dcs].cache, db); |
| (void) zfs_refcount_add_many( |
| &dbuf_caches[dcs].size, |
| db->db.db_size, db); |
| |
| if (dcs == DB_DBUF_METADATA_CACHE) { |
| DBUF_STAT_BUMP(metadata_cache_count); |
| DBUF_STAT_MAX( |
| metadata_cache_size_bytes_max, |
| zfs_refcount_count( |
| &dbuf_caches[dcs].size)); |
| } else { |
| DBUF_STAT_BUMP( |
| cache_levels[db->db_level]); |
| DBUF_STAT_BUMP(cache_count); |
| DBUF_STAT_INCR( |
| cache_levels_bytes[db->db_level], |
| db->db.db_size); |
| DBUF_STAT_MAX(cache_size_bytes_max, |
| zfs_refcount_count( |
| &dbuf_caches[dcs].size)); |
| } |
| mutex_exit(&db->db_mtx); |
| |
| if (db->db_caching_status == DB_DBUF_CACHE && |
| !evicting) { |
| dbuf_evict_notify(); |
| } |
| } |
| |
| if (do_arc_evict) |
| arc_freed(spa, &bp); |
| } |
| } else { |
| mutex_exit(&db->db_mtx); |
| } |
| |
| } |
| |
| #pragma weak dmu_buf_refcount = dbuf_refcount |
| uint64_t |
| dbuf_refcount(dmu_buf_impl_t *db) |
| { |
| return (zfs_refcount_count(&db->db_holds)); |
| } |
| |
| uint64_t |
| dmu_buf_user_refcount(dmu_buf_t *db_fake) |
| { |
| uint64_t holds; |
| dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; |
| |
| mutex_enter(&db->db_mtx); |
| ASSERT3U(zfs_refcount_count(&db->db_holds), >=, db->db_dirtycnt); |
| holds = zfs_refcount_count(&db->db_holds) - db->db_dirtycnt; |
| mutex_exit(&db->db_mtx); |
| |
| return (holds); |
| } |
| |
| void * |
| dmu_buf_replace_user(dmu_buf_t *db_fake, dmu_buf_user_t *old_user, |
| dmu_buf_user_t *new_user) |
| { |
| dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; |
| |
| mutex_enter(&db->db_mtx); |
| dbuf_verify_user(db, DBVU_NOT_EVICTING); |
| if (db->db_user == old_user) |
| db->db_user = new_user; |
| else |
| old_user = db->db_user; |
| dbuf_verify_user(db, DBVU_NOT_EVICTING); |
| mutex_exit(&db->db_mtx); |
| |
| return (old_user); |
| } |
| |
| void * |
| dmu_buf_set_user(dmu_buf_t *db_fake, dmu_buf_user_t *user) |
| { |
| return (dmu_buf_replace_user(db_fake, NULL, user)); |
| } |
| |
| void * |
| dmu_buf_set_user_ie(dmu_buf_t *db_fake, dmu_buf_user_t *user) |
| { |
| dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; |
| |
| db->db_user_immediate_evict = TRUE; |
| return (dmu_buf_set_user(db_fake, user)); |
| } |
| |
| void * |
| dmu_buf_remove_user(dmu_buf_t *db_fake, dmu_buf_user_t *user) |
| { |
| return (dmu_buf_replace_user(db_fake, user, NULL)); |
| } |
| |
| void * |
| dmu_buf_get_user(dmu_buf_t *db_fake) |
| { |
| dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; |
| |
| dbuf_verify_user(db, DBVU_NOT_EVICTING); |
| return (db->db_user); |
| } |
| |
| void |
| dmu_buf_user_evict_wait() |
| { |
| taskq_wait(dbu_evict_taskq); |
| } |
| |
| blkptr_t * |
| dmu_buf_get_blkptr(dmu_buf_t *db) |
| { |
| dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db; |
| return (dbi->db_blkptr); |
| } |
| |
| objset_t * |
| dmu_buf_get_objset(dmu_buf_t *db) |
| { |
| dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db; |
| return (dbi->db_objset); |
| } |
| |
| dnode_t * |
| dmu_buf_dnode_enter(dmu_buf_t *db) |
| { |
| dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db; |
| DB_DNODE_ENTER(dbi); |
| return (DB_DNODE(dbi)); |
| } |
| |
| void |
| dmu_buf_dnode_exit(dmu_buf_t *db) |
| { |
| dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db; |
| DB_DNODE_EXIT(dbi); |
| } |
| |
| static void |
| dbuf_check_blkptr(dnode_t *dn, dmu_buf_impl_t *db) |
| { |
| /* ASSERT(dmu_tx_is_syncing(tx) */ |
| ASSERT(MUTEX_HELD(&db->db_mtx)); |
| |
| if (db->db_blkptr != NULL) |
| return; |
| |
| if (db->db_blkid == DMU_SPILL_BLKID) { |
| db->db_blkptr = DN_SPILL_BLKPTR(dn->dn_phys); |
| BP_ZERO(db->db_blkptr); |
| return; |
| } |
| if (db->db_level == dn->dn_phys->dn_nlevels-1) { |
| /* |
| * This buffer was allocated at a time when there was |
| * no available blkptrs from the dnode, or it was |
| * inappropriate to hook it in (i.e., nlevels mismatch). |
| */ |
| ASSERT(db->db_blkid < dn->dn_phys->dn_nblkptr); |
| ASSERT(db->db_parent == NULL); |
| db->db_parent = dn->dn_dbuf; |
| db->db_blkptr = &dn->dn_phys->dn_blkptr[db->db_blkid]; |
| DBUF_VERIFY(db); |
| } else { |
| dmu_buf_impl_t *parent = db->db_parent; |
| int epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; |
| |
| ASSERT(dn->dn_phys->dn_nlevels > 1); |
| if (parent == NULL) { |
| mutex_exit(&db->db_mtx); |
| rw_enter(&dn->dn_struct_rwlock, RW_READER); |
| parent = dbuf_hold_level(dn, db->db_level + 1, |
| db->db_blkid >> epbs, db); |
| rw_exit(&dn->dn_struct_rwlock); |
| mutex_enter(&db->db_mtx); |
| db->db_parent = parent; |
| } |
| db->db_blkptr = (blkptr_t *)parent->db.db_data + |
| (db->db_blkid & ((1ULL << epbs) - 1)); |
| DBUF_VERIFY(db); |
| } |
| } |
| |
| /* |
| * When syncing out a blocks of dnodes, adjust the block to deal with |
| * encryption. Normally, we make sure the block is decrypted before writing |
| * it. If we have crypt params, then we are writing a raw (encrypted) block, |
| * from a raw receive. In this case, set the ARC buf's crypt params so |
| * that the BP will be filled with the correct byteorder, salt, iv, and mac. |
| */ |
| static void |
| dbuf_prepare_encrypted_dnode_leaf(dbuf_dirty_record_t *dr) |
| { |
| int err; |
| dmu_buf_impl_t *db = dr->dr_dbuf; |
| |
| ASSERT(MUTEX_HELD(&db->db_mtx)); |
| ASSERT3U(db->db.db_object, ==, DMU_META_DNODE_OBJECT); |
| ASSERT3U(db->db_level, ==, 0); |
| |
| if (!db->db_objset->os_raw_receive && arc_is_encrypted(db->db_buf)) { |
| zbookmark_phys_t zb; |
| |
| /* |
| * Unfortunately, there is currently no mechanism for |
| * syncing context to handle decryption errors. An error |
| * here is only possible if an attacker maliciously |
| * changed a dnode block and updated the associated |
| * checksums going up the block tree. |
| */ |
| SET_BOOKMARK(&zb, dmu_objset_id(db->db_objset), |
| db->db.db_object, db->db_level, db->db_blkid); |
| err = arc_untransform(db->db_buf, db->db_objset->os_spa, |
| &zb, B_TRUE); |
| if (err) |
| panic("Invalid dnode block MAC"); |
| } else if (dr->dt.dl.dr_has_raw_params) { |
| (void) arc_release(dr->dt.dl.dr_data, db); |
| arc_convert_to_raw(dr->dt.dl.dr_data, |
| dmu_objset_id(db->db_objset), |
| dr->dt.dl.dr_byteorder, DMU_OT_DNODE, |
| dr->dt.dl.dr_salt, dr->dt.dl.dr_iv, dr->dt.dl.dr_mac); |
| } |
| } |
| |
| /* |
| * dbuf_sync_indirect() is called recursively from dbuf_sync_list() so it |
| * is critical the we not allow the compiler to inline this function in to |
| * dbuf_sync_list() thereby drastically bloating the stack usage. |
| */ |
| noinline static void |
| dbuf_sync_indirect(dbuf_dirty_record_t *dr, dmu_tx_t *tx) |
| { |
| dmu_buf_impl_t *db = dr->dr_dbuf; |
| dnode_t *dn; |
| zio_t *zio; |
| |
| ASSERT(dmu_tx_is_syncing(tx)); |
| |
| dprintf_dbuf_bp(db, db->db_blkptr, "blkptr=%p", db->db_blkptr); |
| |
| mutex_enter(&db->db_mtx); |
| |
| ASSERT(db->db_level > 0); |
| DBUF_VERIFY(db); |
| |
| /* Read the block if it hasn't been read yet. */ |
| if (db->db_buf == NULL) { |
| mutex_exit(&db->db_mtx); |
| (void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED); |
| mutex_enter(&db->db_mtx); |
| } |
| ASSERT3U(db->db_state, ==, DB_CACHED); |
| ASSERT(db->db_buf != NULL); |
| |
| DB_DNODE_ENTER(db); |
| dn = DB_DNODE(db); |
| /* Indirect block size must match what the dnode thinks it is. */ |
| ASSERT3U(db->db.db_size, ==, 1<<dn->dn_phys->dn_indblkshift); |
| dbuf_check_blkptr(dn, db); |
| DB_DNODE_EXIT(db); |
| |
| /* Provide the pending dirty record to child dbufs */ |
| db->db_data_pending = dr; |
| |
| mutex_exit(&db->db_mtx); |
| |
| dbuf_write(dr, db->db_buf, tx); |
| |
| zio = dr->dr_zio; |
| mutex_enter(&dr->dt.di.dr_mtx); |
| dbuf_sync_list(&dr->dt.di.dr_children, db->db_level - 1, tx); |
| ASSERT(list_head(&dr->dt.di.dr_children) == NULL); |
| mutex_exit(&dr->dt.di.dr_mtx); |
| zio_nowait(zio); |
| } |
| |
| #ifdef ZFS_DEBUG |
| /* |
| * Verify that the size of the data in our bonus buffer does not exceed |
| * its recorded size. |
| * |
| * The purpose of this verification is to catch any cases in development |
| * where the size of a phys structure (i.e space_map_phys_t) grows and, |
| * due to incorrect feature management, older pools expect to read more |
| * data even though they didn't actually write it to begin with. |
| * |
| * For a example, this would catch an error in the feature logic where we |
| * open an older pool and we expect to write the space map histogram of |
| * a space map with size SPACE_MAP_SIZE_V0. |
| */ |
| static void |
| dbuf_sync_leaf_verify_bonus_dnode(dbuf_dirty_record_t *dr) |
| { |
| dnode_t *dn = DB_DNODE(dr->dr_dbuf); |
| |
| /* |
| * Encrypted bonus buffers can have data past their bonuslen. |
| * Skip the verification of these blocks. |
| */ |
| if (DMU_OT_IS_ENCRYPTED(dn->dn_bonustype)) |
| return; |
| |
| uint16_t bonuslen = dn->dn_phys->dn_bonuslen; |
| uint16_t maxbonuslen = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots); |
| ASSERT3U(bonuslen, <=, maxbonuslen); |
| |
| arc_buf_t *datap = dr->dt.dl.dr_data; |
| char *datap_end = ((char *)datap) + bonuslen; |
| char *datap_max = ((char *)datap) + maxbonuslen; |
| |
| /* ensure that everything is zero after our data */ |
| for (; datap_end < datap_max; datap_end++) |
| ASSERT(*datap_end == 0); |
| } |
| #endif |
| |
| /* |
| * dbuf_sync_leaf() is called recursively from dbuf_sync_list() so it is |
| * critical the we not allow the compiler to inline this function in to |
| * dbuf_sync_list() thereby drastically bloating the stack usage. |
| */ |
| noinline static void |
| dbuf_sync_leaf(dbuf_dirty_record_t *dr, dmu_tx_t *tx) |
| { |
| arc_buf_t **datap = &dr->dt.dl.dr_data; |
| dmu_buf_impl_t *db = dr->dr_dbuf; |
| dnode_t *dn; |
| objset_t *os; |
| uint64_t txg = tx->tx_txg; |
| |
| ASSERT(dmu_tx_is_syncing(tx)); |
| |
| dprintf_dbuf_bp(db, db->db_blkptr, "blkptr=%p", db->db_blkptr); |
| |
| mutex_enter(&db->db_mtx); |
| /* |
| * To be synced, we must be dirtied. But we |
| * might have been freed after the dirty. |
| */ |
| if (db->db_state == DB_UNCACHED) { |
| /* This buffer has been freed since it was dirtied */ |
| ASSERT(db->db.db_data == NULL); |
| } else if (db->db_state == DB_FILL) { |
| /* This buffer was freed and is now being re-filled */ |
| ASSERT(db->db.db_data != dr->dt.dl.dr_data); |
| } else { |
| ASSERT(db->db_state == DB_CACHED || db->db_state == DB_NOFILL); |
| } |
| DBUF_VERIFY(db); |
| |
| DB_DNODE_ENTER(db); |
| dn = DB_DNODE(db); |
| |
| if (db->db_blkid == DMU_SPILL_BLKID) { |
| mutex_enter(&dn->dn_mtx); |
| if (!(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR)) { |
| /* |
| * In the previous transaction group, the bonus buffer |
| * was entirely used to store the attributes for the |
| * dnode which overrode the dn_spill field. However, |
| * when adding more attributes to the file a spill |
| * block was required to hold the extra attributes. |
| * |
| * Make sure to clear the garbage left in the dn_spill |
| * field from the previous attributes in the bonus |
| * buffer. Otherwise, after writing out the spill |
| * block to the new allocated dva, it will free |
| * the old block pointed to by the invalid dn_spill. |
| */ |
| db->db_blkptr = NULL; |
| } |
| dn->dn_phys->dn_flags |= DNODE_FLAG_SPILL_BLKPTR; |
| mutex_exit(&dn->dn_mtx); |
| } |
| |
| /* |
| * If this is a bonus buffer, simply copy the bonus data into the |
| * dnode. It will be written out when the dnode is synced (and it |
| * will be synced, since it must have been dirty for dbuf_sync to |
| * be called). |
| */ |
| if (db->db_blkid == DMU_BONUS_BLKID) { |
| dbuf_dirty_record_t **drp; |
| |
| ASSERT(*datap != NULL); |
| ASSERT0(db->db_level); |
| ASSERT3U(DN_MAX_BONUS_LEN(dn->dn_phys), <=, |
| DN_SLOTS_TO_BONUSLEN(dn->dn_phys->dn_extra_slots + 1)); |
| bcopy(*datap, DN_BONUS(dn->dn_phys), |
| DN_MAX_BONUS_LEN(dn->dn_phys)); |
| DB_DNODE_EXIT(db); |
| |
| #ifdef ZFS_DEBUG |
| dbuf_sync_leaf_verify_bonus_dnode(dr); |
| #endif |
| |
| if (*datap != db->db.db_data) { |
| int slots = DB_DNODE(db)->dn_num_slots; |
| int bonuslen = DN_SLOTS_TO_BONUSLEN(slots); |
| kmem_free(*datap, bonuslen); |
| arc_space_return(bonuslen, ARC_SPACE_BONUS); |
| } |
| db->db_data_pending = NULL; |
| drp = &db->db_last_dirty; |
| while (*drp != dr) |
| drp = &(*drp)->dr_next; |
| ASSERT(dr->dr_next == NULL); |
| ASSERT(dr->dr_dbuf == db); |
| *drp = dr->dr_next; |
| if (dr->dr_dbuf->db_level != 0) { |
| mutex_destroy(&dr->dt.di.dr_mtx); |
| list_destroy(&dr->dt.di.dr_children); |
| } |
| kmem_free(dr, sizeof (dbuf_dirty_record_t)); |
| ASSERT(db->db_dirtycnt > 0); |
| db->db_dirtycnt -= 1; |
| dbuf_rele_and_unlock(db, (void *)(uintptr_t)txg, B_FALSE); |
| return; |
| } |
| |
| os = dn->dn_objset; |
| |
| /* |
| * This function may have dropped the db_mtx lock allowing a dmu_sync |
| * operation to sneak in. As a result, we need to ensure that we |
| * don't check the dr_override_state until we have returned from |
| * dbuf_check_blkptr. |
| */ |
| dbuf_check_blkptr(dn, db); |
| |
| /* |
| * If this buffer is in the middle of an immediate write, |
| * wait for the synchronous IO to complete. |
| */ |
| while (dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC) { |
| ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT); |
| cv_wait(&db->db_changed, &db->db_mtx); |
| ASSERT(dr->dt.dl.dr_override_state != DR_NOT_OVERRIDDEN); |
| } |
| |
| /* |
| * If this is a dnode block, ensure it is appropriately encrypted |
| * or decrypted, depending on what we are writing to it this txg. |
| */ |
| if (os->os_encrypted && dn->dn_object == DMU_META_DNODE_OBJECT) |
| dbuf_prepare_encrypted_dnode_leaf(dr); |
| |
| if (db->db_state != DB_NOFILL && |
| dn->dn_object != DMU_META_DNODE_OBJECT && |
| zfs_refcount_count(&db->db_holds) > 1 && |
| dr->dt.dl.dr_override_state != DR_OVERRIDDEN && |
| *datap == db->db_buf) { |
| /* |
| * If this buffer is currently "in use" (i.e., there |
| * are active holds and db_data still references it), |
| * then make a copy before we start the write so that |
| * any modifications from the open txg will not leak |
| * into this write. |
| * |
| * NOTE: this copy does not need to be made for |
| * objects only modified in the syncing context (e.g. |
| * DNONE_DNODE blocks). |
| */ |
| int psize = arc_buf_size(*datap); |
| int lsize = arc_buf_lsize(*datap); |
| arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db); |
| enum zio_compress compress_type = arc_get_compression(*datap); |
| |
| if (arc_is_encrypted(*datap)) { |
| boolean_t byteorder; |
| uint8_t salt[ZIO_DATA_SALT_LEN]; |
| uint8_t iv[ZIO_DATA_IV_LEN]; |
| uint8_t mac[ZIO_DATA_MAC_LEN]; |
| |
| arc_get_raw_params(*datap, &byteorder, salt, iv, mac); |
| *datap = arc_alloc_raw_buf(os->os_spa, db, |
| dmu_objset_id(os), byteorder, salt, iv, mac, |
| dn->dn_type, psize, lsize, compress_type); |
| } else if (compress_type != ZIO_COMPRESS_OFF) { |
| ASSERT3U(type, ==, ARC_BUFC_DATA); |
| *datap = arc_alloc_compressed_buf(os->os_spa, db, |
| psize, lsize, compress_type); |
| } else { |
| *datap = arc_alloc_buf(os->os_spa, db, type, psize); |
| } |
| bcopy(db->db.db_data, (*datap)->b_data, psize); |
| } |
| db->db_data_pending = dr; |
| |
| mutex_exit(&db->db_mtx); |
| |
| dbuf_write(dr, *datap, tx); |
| |
| ASSERT(!list_link_active(&dr->dr_dirty_node)); |
| if (dn->dn_object == DMU_META_DNODE_OBJECT) { |
| list_insert_tail(&dn->dn_dirty_records[txg & TXG_MASK], dr); |
| DB_DNODE_EXIT(db); |
| } else { |
| /* |
| * Although zio_nowait() does not "wait for an IO", it does |
| * initiate the IO. If this is an empty write it seems plausible |
| * that the IO could actually be completed before the nowait |
| * returns. We need to DB_DNODE_EXIT() first in case |
| * zio_nowait() invalidates the dbuf. |
| */ |
| DB_DNODE_EXIT(db); |
| zio_nowait(dr->dr_zio); |
| } |
| } |
| |
| void |
| dbuf_sync_list(list_t *list, int level, dmu_tx_t *tx) |
| { |
| dbuf_dirty_record_t *dr; |
| |
| while ((dr = list_head(list))) { |
| if (dr->dr_zio != NULL) { |
| /* |
| * If we find an already initialized zio then we |
| * are processing the meta-dnode, and we have finished. |
| * The dbufs for all dnodes are put back on the list |
| * during processing, so that we can zio_wait() |
| * these IOs after initiating all child IOs. |
| */ |
| ASSERT3U(dr->dr_dbuf->db.db_object, ==, |
| DMU_META_DNODE_OBJECT); |
| break; |
| } |
| if (dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID && |
| dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) { |
| VERIFY3U(dr->dr_dbuf->db_level, ==, level); |
| } |
| list_remove(list, dr); |
| if (dr->dr_dbuf->db_level > 0) |
| dbuf_sync_indirect(dr, tx); |
| else |
| dbuf_sync_leaf(dr, tx); |
| } |
| } |
| |
| /* ARGSUSED */ |
| static void |
| dbuf_write_ready(zio_t *zio, arc_buf_t *buf, void *vdb) |
| { |
| dmu_buf_impl_t *db = vdb; |
| dnode_t *dn; |
| blkptr_t *bp = zio->io_bp; |
| blkptr_t *bp_orig = &zio->io_bp_orig; |
| spa_t *spa = zio->io_spa; |
| int64_t delta; |
| uint64_t fill = 0; |
| int i; |
| |
| ASSERT3P(db->db_blkptr, !=, NULL); |
| ASSERT3P(&db->db_data_pending->dr_bp_copy, ==, bp); |
| |
| DB_DNODE_ENTER(db); |
| dn = DB_DNODE(db); |
| delta = bp_get_dsize_sync(spa, bp) - bp_get_dsize_sync(spa, bp_orig); |
| dnode_diduse_space(dn, delta - zio->io_prev_space_delta); |
| zio->io_prev_space_delta = delta; |
| |
| if (bp->blk_birth != 0) { |
| ASSERT((db->db_blkid != DMU_SPILL_BLKID && |
| BP_GET_TYPE(bp) == dn->dn_type) || |
| (db->db_blkid == DMU_SPILL_BLKID && |
| BP_GET_TYPE(bp) == dn->dn_bonustype) || |
| BP_IS_EMBEDDED(bp)); |
| ASSERT(BP_GET_LEVEL(bp) == db->db_level); |
| } |
| |
| mutex_enter(&db->db_mtx); |
| |
| #ifdef ZFS_DEBUG |
| if (db->db_blkid == DMU_SPILL_BLKID) { |
| ASSERT(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR); |
| ASSERT(!(BP_IS_HOLE(bp)) && |
| db->db_blkptr == DN_SPILL_BLKPTR(dn->dn_phys)); |
| } |
| #endif |
| |
| if (db->db_level == 0) { |
| mutex_enter(&dn->dn_mtx); |
| if (db->db_blkid > dn->dn_phys->dn_maxblkid && |
| db->db_blkid != DMU_SPILL_BLKID) { |
| ASSERT0(db->db_objset->os_raw_receive); |
| dn->dn_phys->dn_maxblkid = db->db_blkid; |
| } |
| mutex_exit(&dn->dn_mtx); |
| |
| if (dn->dn_type == DMU_OT_DNODE) { |
| i = 0; |
| while (i < db->db.db_size) { |
| dnode_phys_t *dnp = |
| (void *)(((char *)db->db.db_data) + i); |
| |
| i += DNODE_MIN_SIZE; |
| if (dnp->dn_type != DMU_OT_NONE) { |
| fill++; |
| i += dnp->dn_extra_slots * |
| DNODE_MIN_SIZE; |
| } |
| } |
| } else { |
| if (BP_IS_HOLE(bp)) { |
| fill = 0; |
| } else { |
| fill = 1; |
| } |
| } |
| } else { |
| blkptr_t *ibp = db->db.db_data; |
| ASSERT3U(db->db.db_size, ==, 1<<dn->dn_phys->dn_indblkshift); |
| for (i = db->db.db_size >> SPA_BLKPTRSHIFT; i > 0; i--, ibp++) { |
| if (BP_IS_HOLE(ibp)) |
| continue; |
| fill += BP_GET_FILL(ibp); |
| } |
| } |
| DB_DNODE_EXIT(db); |
| |
| if (!BP_IS_EMBEDDED(bp)) |
| BP_SET_FILL(bp, fill); |
| |
| mutex_exit(&db->db_mtx); |
| |
| rw_enter(&dn->dn_struct_rwlock, RW_WRITER); |
| *db->db_blkptr = *bp; |
| rw_exit(&dn->dn_struct_rwlock); |
| } |
| |
| /* ARGSUSED */ |
| /* |
| * This function gets called just prior to running through the compression |
| * stage of the zio pipeline. If we're an indirect block comprised of only |
| * holes, then we want this indirect to be compressed away to a hole. In |
| * order to do that we must zero out any information about the holes that |
| * this indirect points to prior to before we try to compress it. |
| */ |
| static void |
| dbuf_write_children_ready(zio_t *zio, arc_buf_t *buf, void *vdb) |
| { |
| dmu_buf_impl_t *db = vdb; |
| dnode_t *dn; |
| blkptr_t *bp; |
| unsigned int epbs, i; |
| |
| ASSERT3U(db->db_level, >, 0); |
| DB_DNODE_ENTER(db); |
| dn = DB_DNODE(db); |
| epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; |
| ASSERT3U(epbs, <, 31); |
| |
| /* Determine if all our children are holes */ |
| for (i = 0, bp = db->db.db_data; i < 1ULL << epbs; i++, bp++) { |
| if (!BP_IS_HOLE(bp)) |
| break; |
| } |
| |
| /* |
| * If all the children are holes, then zero them all out so that |
| * we may get compressed away. |
| */ |
| if (i == 1ULL << epbs) { |
| /* |
| * We only found holes. Grab the rwlock to prevent |
| * anybody from reading the blocks we're about to |
| * zero out. |
| */ |
| rw_enter(&dn->dn_struct_rwlock, RW_WRITER); |
| bzero(db->db.db_data, db->db.db_size); |
| rw_exit(&dn->dn_struct_rwlock); |
| } |
| DB_DNODE_EXIT(db); |
| } |
| |
| /* |
| * The SPA will call this callback several times for each zio - once |
| * for every physical child i/o (zio->io_phys_children times). This |
| * allows the DMU to monitor the progress of each logical i/o. For example, |
| * there may be 2 copies of an indirect block, or many fragments of a RAID-Z |
| * block. There may be a long delay before all copies/fragments are completed, |
| * so this callback allows us to retire dirty space gradually, as the physical |
| * i/os complete. |
| */ |
| /* ARGSUSED */ |
| static void |
| dbuf_write_physdone(zio_t *zio, arc_buf_t *buf, void *arg) |
| { |
| dmu_buf_impl_t *db = arg; |
| objset_t *os = db->db_objset; |
| dsl_pool_t *dp = dmu_objset_pool(os); |
| dbuf_dirty_record_t *dr; |
| int delta = 0; |
| |
| dr = db->db_data_pending; |
| ASSERT3U(dr->dr_txg, ==, zio->io_txg); |
| |
| /* |
| * The callback will be called io_phys_children times. Retire one |
| * portion of our dirty space each time we are called. Any rounding |
| * error will be cleaned up by dbuf_write_done(). |
| */ |
| delta = dr->dr_accounted / zio->io_phys_children; |
| dsl_pool_undirty_space(dp, delta, zio->io_txg); |
| } |
| |
| /* ARGSUSED */ |
| static void |
| dbuf_write_done(zio_t *zio, arc_buf_t *buf, void *vdb) |
| { |
| dmu_buf_impl_t *db = vdb; |
| blkptr_t *bp_orig = &zio->io_bp_orig; |
| blkptr_t *bp = db->db_blkptr; |
| objset_t *os = db->db_objset; |
| dmu_tx_t *tx = os->os_synctx; |
| dbuf_dirty_record_t **drp, *dr; |
| |
| ASSERT0(zio->io_error); |
| ASSERT(db->db_blkptr == bp); |
| |
| /* |
| * For nopwrites and rewrites we ensure that the bp matches our |
| * original and bypass all the accounting. |
| */ |
| if (zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE)) { |
| ASSERT(BP_EQUAL(bp, bp_orig)); |
| } else { |
| dsl_dataset_t *ds = os->os_dsl_dataset; |
| (void) dsl_dataset_block_kill(ds, bp_orig, tx, B_TRUE); |
| dsl_dataset_block_born(ds, bp, tx); |
| } |
| |
| mutex_enter(&db->db_mtx); |
| |
| DBUF_VERIFY(db); |
| |
| drp = &db->db_last_dirty; |
| while ((dr = *drp) != db->db_data_pending) |
| drp = &dr->dr_next; |
| ASSERT(!list_link_active(&dr->dr_dirty_node)); |
| ASSERT(dr->dr_dbuf == db); |
| ASSERT(dr->dr_next == NULL); |
| *drp = dr->dr_next; |
| |
| #ifdef ZFS_DEBUG |
| if (db->db_blkid == DMU_SPILL_BLKID) { |
| dnode_t *dn; |
| |
| DB_DNODE_ENTER(db); |
| dn = DB_DNODE(db); |
| ASSERT(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR); |
| ASSERT(!(BP_IS_HOLE(db->db_blkptr)) && |
| db->db_blkptr == DN_SPILL_BLKPTR(dn->dn_phys)); |
| DB_DNODE_EXIT(db); |
| } |
| #endif |
| |
| if (db->db_level == 0) { |
| ASSERT(db->db_blkid != DMU_BONUS_BLKID); |
| ASSERT(dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN); |
| if (db->db_state != DB_NOFILL) { |
| if (dr->dt.dl.dr_data != db->db_buf) |
| arc_buf_destroy(dr->dt.dl.dr_data, db); |
| } |
| } else { |
| dnode_t *dn; |
| |
| DB_DNODE_ENTER(db); |
| dn = DB_DNODE(db); |
| ASSERT(list_head(&dr->dt.di.dr_children) == NULL); |
| ASSERT3U(db->db.db_size, ==, 1 << dn->dn_phys->dn_indblkshift); |
| if (!BP_IS_HOLE(db->db_blkptr)) { |
| ASSERTV(int epbs = dn->dn_phys->dn_indblkshift - |
| SPA_BLKPTRSHIFT); |
| ASSERT3U(db->db_blkid, <=, |
| dn->dn_phys->dn_maxblkid >> (db->db_level * epbs)); |
| ASSERT3U(BP_GET_LSIZE(db->db_blkptr), ==, |
| db->db.db_size); |
| } |
| DB_DNODE_EXIT(db); |
| mutex_destroy(&dr->dt.di.dr_mtx); |
| list_destroy(&dr->dt.di.dr_children); |
| } |
| |
| cv_broadcast(&db->db_changed); |
| ASSERT(db->db_dirtycnt > 0); |
| db->db_dirtycnt -= 1; |
| db->db_data_pending = NULL; |
| dbuf_rele_and_unlock(db, (void *)(uintptr_t)tx->tx_txg, B_FALSE); |
| |
| /* |
| * If we didn't do a physical write in this ZIO and we |
| * still ended up here, it means that the space of the |
| * dbuf that we just released (and undirtied) above hasn't |
| * been marked as undirtied in the pool's accounting. |
| * |
| * Thus, we undirty that space in the pool's view of the |
| * world here. For physical writes this type of update |
| * happens in dbuf_write_physdone(). |
| * |
| * If we did a physical write, cleanup any rounding errors |
| * that came up due to writing multiple copies of a block |
| * on disk [see dbuf_write_physdone()]. |
| */ |
| if (zio->io_phys_children == 0) { |
| dsl_pool_undirty_space(dmu_objset_pool(os), |
| dr->dr_accounted, zio->io_txg); |
| } else { |
| dsl_pool_undirty_space(dmu_objset_pool(os), |
| dr->dr_accounted % zio->io_phys_children, zio->io_txg); |
| } |
| |
| kmem_free(dr, sizeof (dbuf_dirty_record_t)); |
| } |
| |
| static void |
| dbuf_write_nofill_ready(zio_t *zio) |
| { |
| dbuf_write_ready(zio, NULL, zio->io_private); |
| } |
| |
| static void |
| dbuf_write_nofill_done(zio_t *zio) |
| { |
| dbuf_write_done(zio, NULL, zio->io_private); |
| } |
| |
| static void |
| dbuf_write_override_ready(zio_t *zio) |
| { |
| dbuf_dirty_record_t *dr = zio->io_private; |
| dmu_buf_impl_t *db = dr->dr_dbuf; |
| |
| dbuf_write_ready(zio, NULL, db); |
| } |
| |
| static void |
| dbuf_write_override_done(zio_t *zio) |
| { |
| dbuf_dirty_record_t *dr = zio->io_private; |
| dmu_buf_impl_t *db = dr->dr_dbuf; |
| blkptr_t *obp = &dr->dt.dl.dr_overridden_by; |
| |
| mutex_enter(&db->db_mtx); |
| if (!BP_EQUAL(zio->io_bp, obp)) { |
| if (!BP_IS_HOLE(obp)) |
| dsl_free(spa_get_dsl(zio->io_spa), zio->io_txg, obp); |
| arc_release(dr->dt.dl.dr_data, db); |
| } |
| mutex_exit(&db->db_mtx); |
| |
| dbuf_write_done(zio, NULL, db); |
| |
| if (zio->io_abd != NULL) |
| abd_put(zio->io_abd); |
| } |
| |
| typedef struct dbuf_remap_impl_callback_arg { |
| objset_t *drica_os; |
| uint64_t drica_blk_birth; |
| dmu_tx_t *drica_tx; |
| } dbuf_remap_impl_callback_arg_t; |
| |
| static void |
| dbuf_remap_impl_callback(uint64_t vdev, uint64_t offset, uint64_t size, |
| void *arg) |
| { |
| dbuf_remap_impl_callback_arg_t *drica = arg; |
| objset_t *os = drica->drica_os; |
| spa_t *spa = dmu_objset_spa(os); |
| dmu_tx_t *tx = drica->drica_tx; |
| |
| ASSERT(dsl_pool_sync_context(spa_get_dsl(spa))); |
| |
| if (os == spa_meta_objset(spa)) { |
| spa_vdev_indirect_mark_obsolete(spa, vdev, offset, size, tx); |
| } else { |
| dsl_dataset_block_remapped(dmu_objset_ds(os), vdev, offset, |
| size, drica->drica_blk_birth, tx); |
| } |
| } |
| |
| static void |
| dbuf_remap_impl(dnode_t *dn, blkptr_t *bp, dmu_tx_t *tx) |
| { |
| blkptr_t bp_copy = *bp; |
| spa_t *spa = dmu_objset_spa(dn->dn_objset); |
| dbuf_remap_impl_callback_arg_t drica; |
| |
| ASSERT(dsl_pool_sync_context(spa_get_dsl(spa))); |
| |
| drica.drica_os = dn->dn_objset; |
| drica.drica_blk_birth = bp->blk_birth; |
| drica.drica_tx = tx; |
| if (spa_remap_blkptr(spa, &bp_copy, dbuf_remap_impl_callback, |
| &drica)) { |
| /* |
| * The struct_rwlock prevents dbuf_read_impl() from |
| * dereferencing the BP while we are changing it. To |
| * avoid lock contention, only grab it when we are actually |
| * changing the BP. |
| */ |
| rw_enter(&dn->dn_struct_rwlock, RW_WRITER); |
| *bp = bp_copy; |
| rw_exit(&dn->dn_struct_rwlock); |
| } |
| } |
| |
| /* |
| * Returns true if a dbuf_remap would modify the dbuf. We do this by attempting |
| * to remap a copy of every bp in the dbuf. |
| */ |
| boolean_t |
| dbuf_can_remap(const dmu_buf_impl_t *db) |
| { |
| spa_t *spa = dmu_objset_spa(db->db_objset); |
| blkptr_t *bp = db->db.db_data; |
| boolean_t ret = B_FALSE; |
| |
| ASSERT3U(db->db_level, >, 0); |
| ASSERT3S(db->db_state, ==, DB_CACHED); |
| |
| ASSERT(spa_feature_is_active(spa, SPA_FEATURE_DEVICE_REMOVAL)); |
| |
| spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER); |
| for (int i = 0; i < db->db.db_size >> SPA_BLKPTRSHIFT; i++) { |
| blkptr_t bp_copy = bp[i]; |
| if (spa_remap_blkptr(spa, &bp_copy, NULL, NULL)) { |
| ret = B_TRUE; |
| break; |
| } |
| } |
| spa_config_exit(spa, SCL_VDEV, FTAG); |
| |
| return (ret); |
| } |
| |
| boolean_t |
| dnode_needs_remap(const dnode_t *dn) |
| { |
| spa_t *spa = dmu_objset_spa(dn->dn_objset); |
| boolean_t ret = B_FALSE; |
| |
| if (dn->dn_phys->dn_nlevels == 0) { |
| return (B_FALSE); |
| } |
| |
| ASSERT(spa_feature_is_active(spa, SPA_FEATURE_DEVICE_REMOVAL)); |
| |
| spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER); |
| for (int j = 0; j < dn->dn_phys->dn_nblkptr; j++) { |
| blkptr_t bp_copy = dn->dn_phys->dn_blkptr[j]; |
| if (spa_remap_blkptr(spa, &bp_copy, NULL, NULL)) { |
| ret = B_TRUE; |
| break; |
| } |
| } |
| spa_config_exit(spa, SCL_VDEV, FTAG); |
| |
| return (ret); |
| } |
| |
| /* |
| * Remap any existing BP's to concrete vdevs, if possible. |
| */ |
| static void |
| dbuf_remap(dnode_t *dn, dmu_buf_impl_t *db, dmu_tx_t *tx) |
| { |
| spa_t *spa = dmu_objset_spa(db->db_objset); |
| ASSERT(dsl_pool_sync_context(spa_get_dsl(spa))); |
| |
| if (!spa_feature_is_active(spa, SPA_FEATURE_DEVICE_REMOVAL)) |
| return; |
| |
| if (db->db_level > 0) { |
| blkptr_t *bp = db->db.db_data; |
| for (int i = 0; i < db->db.db_size >> SPA_BLKPTRSHIFT; i++) { |
| dbuf_remap_impl(dn, &bp[i], tx); |
| } |
| } else if (db->db.db_object == DMU_META_DNODE_OBJECT) { |
| dnode_phys_t *dnp = db->db.db_data; |
| ASSERT3U(db->db_dnode_handle->dnh_dnode->dn_type, ==, |
| DMU_OT_DNODE); |
| for (int i = 0; i < db->db.db_size >> DNODE_SHIFT; |
| i += dnp[i].dn_extra_slots + 1) { |
| for (int j = 0; j < dnp[i].dn_nblkptr; j++) { |
| dbuf_remap_impl(dn, &dnp[i].dn_blkptr[j], tx); |
| } |
| } |
| } |
| } |
| |
| |
| /* Issue I/O to commit a dirty buffer to disk. */ |
| static void |
| dbuf_write(dbuf_dirty_record_t *dr, arc_buf_t *data, dmu_tx_t *tx) |
| { |
| dmu_buf_impl_t *db = dr->dr_dbuf; |
| dnode_t *dn; |
| objset_t *os; |
| dmu_buf_impl_t *parent = db->db_parent; |
| uint64_t txg = tx->tx_txg; |
| zbookmark_phys_t zb; |
| zio_prop_t zp; |
| zio_t *zio; |
| int wp_flag = 0; |
| |
| ASSERT(dmu_tx_is_syncing(tx)); |
| |
| DB_DNODE_ENTER(db); |
| dn = DB_DNODE(db); |
| os = dn->dn_objset; |
| |
| if (db->db_state != DB_NOFILL) { |
| if (db->db_level > 0 || dn->dn_type == DMU_OT_DNODE) { |
| /* |
| * Private object buffers are released here rather |
| * than in dbuf_dirty() since they are only modified |
| * in the syncing context and we don't want the |
| * overhead of making multiple copies of the data. |
| */ |
| if (BP_IS_HOLE(db->db_blkptr)) { |
| arc_buf_thaw(data); |
| } else { |
| dbuf_release_bp(db); |
| } |
| dbuf_remap(dn, db, tx); |
| } |
| } |
| |
| if (parent != dn->dn_dbuf) { |
| /* Our parent is an indirect block. */ |
| /* We have a dirty parent that has been scheduled for write. */ |
| ASSERT(parent && parent->db_data_pending); |
| /* Our parent's buffer is one level closer to the dnode. */ |
| ASSERT(db->db_level == parent->db_level-1); |
| /* |
| * We're about to modify our parent's db_data by modifying |
| * our block pointer, so the parent must be released. |
| */ |
| ASSERT(arc_released(parent->db_buf)); |
| zio = parent->db_data_pending->dr_zio; |
| } else { |
| /* Our parent is the dnode itself. */ |
| ASSERT((db->db_level == dn->dn_phys->dn_nlevels-1 && |
| db->db_blkid != DMU_SPILL_BLKID) || |
| (db->db_blkid == DMU_SPILL_BLKID && db->db_level == 0)); |
| if (db->db_blkid != DMU_SPILL_BLKID) |
| ASSERT3P(db->db_blkptr, ==, |
| &dn->dn_phys->dn_blkptr[db->db_blkid]); |
| zio = dn->dn_zio; |
| } |
| |
| ASSERT(db->db_level == 0 || data == db->db_buf); |
| ASSERT3U(db->db_blkptr->blk_birth, <=, txg); |
| ASSERT(zio); |
| |
| SET_BOOKMARK(&zb, os->os_dsl_dataset ? |
| os->os_dsl_dataset->ds_object : DMU_META_OBJSET, |
| db->db.db_object, db->db_level, db->db_blkid); |
| |
| if (db->db_blkid == DMU_SPILL_BLKID) |
| wp_flag = WP_SPILL; |
| wp_flag |= (db->db_state == DB_NOFILL) ? WP_NOFILL : 0; |
| |
| dmu_write_policy(os, dn, db->db_level, wp_flag, &zp); |
| DB_DNODE_EXIT(db); |
| |
| /* |
| * We copy the blkptr now (rather than when we instantiate the dirty |
| * record), because its value can change between open context and |
| * syncing context. We do not need to hold dn_struct_rwlock to read |
| * db_blkptr because we are in syncing context. |
| */ |
| dr->dr_bp_copy = *db->db_blkptr; |
| |
| if (db->db_level == 0 && |
| dr->dt.dl.dr_override_state == DR_OVERRIDDEN) { |
| /* |
| * The BP for this block has been provided by open context |
| * (by dmu_sync() or dmu_buf_write_embedded()). |
| */ |
| abd_t *contents = (data != NULL) ? |
| abd_get_from_buf(data->b_data, arc_buf_size(data)) : NULL; |
| |
| dr->dr_zio = zio_write(zio, os->os_spa, txg, |
| &dr->dr_bp_copy, contents, db->db.db_size, db->db.db_size, |
| &zp, dbuf_write_override_ready, NULL, NULL, |
| dbuf_write_override_done, |
| dr, ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_MUSTSUCCEED, &zb); |
| mutex_enter(&db->db_mtx); |
| dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN; |
| zio_write_override(dr->dr_zio, &dr->dt.dl.dr_overridden_by, |
| dr->dt.dl.dr_copies, dr->dt.dl.dr_nopwrite); |
| mutex_exit(&db->db_mtx); |
| } else if (db->db_state == DB_NOFILL) { |
| ASSERT(zp.zp_checksum == ZIO_CHECKSUM_OFF || |
| zp.zp_checksum == ZIO_CHECKSUM_NOPARITY); |
| dr->dr_zio = zio_write(zio, os->os_spa, txg, |
| &dr->dr_bp_copy, NULL, db->db.db_size, db->db.db_size, &zp, |
| dbuf_write_nofill_ready, NULL, NULL, |
| dbuf_write_nofill_done, db, |
| ZIO_PRIORITY_ASYNC_WRITE, |
| ZIO_FLAG_MUSTSUCCEED | ZIO_FLAG_NODATA, &zb); |
| } else { |
| ASSERT(arc_released(data)); |
| |
| /* |
| * For indirect blocks, we want to setup the children |
| * ready callback so that we can properly handle an indirect |
| * block that only contains holes. |
| */ |
| arc_write_done_func_t *children_ready_cb = NULL; |
| if (db->db_level != 0) |
| children_ready_cb = dbuf_write_children_ready; |
| |
| dr->dr_zio = arc_write(zio, os->os_spa, txg, |
| &dr->dr_bp_copy, data, DBUF_IS_L2CACHEABLE(db), |
| &zp, dbuf_write_ready, |
| children_ready_cb, dbuf_write_physdone, |
| dbuf_write_done, db, ZIO_PRIORITY_ASYNC_WRITE, |
| ZIO_FLAG_MUSTSUCCEED, &zb); |
| } |
| } |
| |
| #if defined(_KERNEL) |
| EXPORT_SYMBOL(dbuf_find); |
| EXPORT_SYMBOL(dbuf_is_metadata); |
| EXPORT_SYMBOL(dbuf_destroy); |
| EXPORT_SYMBOL(dbuf_loan_arcbuf); |
| EXPORT_SYMBOL(dbuf_whichblock); |
| EXPORT_SYMBOL(dbuf_read); |
| EXPORT_SYMBOL(dbuf_unoverride); |
| EXPORT_SYMBOL(dbuf_free_range); |
| EXPORT_SYMBOL(dbuf_new_size); |
| EXPORT_SYMBOL(dbuf_release_bp); |
| EXPORT_SYMBOL(dbuf_dirty); |
| EXPORT_SYMBOL(dmu_buf_set_crypt_params); |
| EXPORT_SYMBOL(dmu_buf_will_dirty); |
| EXPORT_SYMBOL(dmu_buf_is_dirty); |
| EXPORT_SYMBOL(dmu_buf_will_not_fill); |
| EXPORT_SYMBOL(dmu_buf_will_fill); |
| EXPORT_SYMBOL(dmu_buf_fill_done); |
| EXPORT_SYMBOL(dmu_buf_rele); |
| EXPORT_SYMBOL(dbuf_assign_arcbuf); |
| EXPORT_SYMBOL(dbuf_prefetch); |
| EXPORT_SYMBOL(dbuf_hold_impl); |
| EXPORT_SYMBOL(dbuf_hold); |
| EXPORT_SYMBOL(dbuf_hold_level); |
| EXPORT_SYMBOL(dbuf_create_bonus); |
| EXPORT_SYMBOL(dbuf_spill_set_blksz); |
| EXPORT_SYMBOL(dbuf_rm_spill); |
| EXPORT_SYMBOL(dbuf_add_ref); |
| EXPORT_SYMBOL(dbuf_rele); |
| EXPORT_SYMBOL(dbuf_rele_and_unlock); |
| EXPORT_SYMBOL(dbuf_refcount); |
| EXPORT_SYMBOL(dbuf_sync_list); |
| EXPORT_SYMBOL(dmu_buf_set_user); |
| EXPORT_SYMBOL(dmu_buf_set_user_ie); |
| EXPORT_SYMBOL(dmu_buf_get_user); |
| EXPORT_SYMBOL(dmu_buf_get_blkptr); |
| |
| /* BEGIN CSTYLED */ |
| module_param(dbuf_cache_max_bytes, ulong, 0644); |
| MODULE_PARM_DESC(dbuf_cache_max_bytes, |
| "Maximum size in bytes of the dbuf cache."); |
| |
| module_param(dbuf_cache_hiwater_pct, uint, 0644); |
| MODULE_PARM_DESC(dbuf_cache_hiwater_pct, |
| "Percentage over dbuf_cache_max_bytes when dbufs must be evicted " |
| "directly."); |
| |
| module_param(dbuf_cache_lowater_pct, uint, 0644); |
| MODULE_PARM_DESC(dbuf_cache_lowater_pct, |
| "Percentage below dbuf_cache_max_bytes when the evict thread stops " |
| "evicting dbufs."); |
| |
| module_param(dbuf_metadata_cache_max_bytes, ulong, 0644); |
| MODULE_PARM_DESC(dbuf_metadata_cache_max_bytes, |
| "Maximum size in bytes of the dbuf metadata cache."); |
| |
| module_param(dbuf_cache_shift, int, 0644); |
| MODULE_PARM_DESC(dbuf_cache_shift, |
| "Set the size of the dbuf cache to a log2 fraction of arc size."); |
| |
| module_param(dbuf_metadata_cache_shift, int, 0644); |
| MODULE_PARM_DESC(dbuf_cache_shift, |
| "Set the size of the dbuf metadata cache to a log2 fraction of " |
| "arc size."); |
| /* END CSTYLED */ |
| #endif |