* CDDL HEADER END
*/
/*
- * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
- * Use is subject to license terms.
+ * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
+ * Copyright (c) 2012, 2017 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/spa.h>
#include <sys/zio.h>
#include <sys/dmu_zfetch.h>
-
-static void dbuf_destroy(dmu_buf_impl_t *db);
-static int dbuf_undirty(dmu_buf_impl_t *db, dmu_tx_t *tx);
+#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>
+
+struct dbuf_hold_impl_data {
+ /* 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;
+ int dh_depth;
+};
+
+static void __dbuf_hold_impl_init(struct dbuf_hold_impl_data *dh,
+ dnode_t *dn, uint8_t level, uint64_t blkid, boolean_t fail_sparse,
+ boolean_t fail_uncached,
+ void *tag, dmu_buf_impl_t **dbp, int depth);
+static int __dbuf_hold_impl(struct dbuf_hold_impl_data *dh);
+
+uint_t zfs_dbuf_evict_key;
+
+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);
-static arc_done_func_t dbuf_write_ready;
-static arc_done_func_t dbuf_write_done;
-static zio_done_func_t dbuf_skip_write_ready;
-static zio_done_func_t dbuf_skip_write_done;
+
+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_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;
+
+/*
+ * 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 are added to the dbuf cache 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.
+ * Dbufs that are aged out of the cache will be immediately destroyed and
+ * become eligible for arc eviction.
+ */
+static multilist_t *dbuf_cache;
+static refcount_t dbuf_cache_size;
+unsigned long dbuf_cache_max_bytes = 100 * 1024 * 1024;
+
+/* Cap the size of the dbuf cache to log2 fraction of arc size. */
+int dbuf_cache_max_shift = 5;
+
+/*
+ * The 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
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);
refcount_create(&db->db_holds);
+ multilist_link_init(&db->db_cache_link);
+
return (0);
}
dmu_buf_impl_t *db = vdb;
mutex_destroy(&db->db_mtx);
cv_destroy(&db->db_changed);
+ ASSERT(!multilist_link_active(&db->db_cache_link));
refcount_destroy(&db->db_holds);
}
return (crc);
}
-#define DBUF_HASH(os, obj, level, blkid) dbuf_hash(os, obj, level, blkid);
-
#define DBUF_EQUAL(dbuf, os, obj, level, blkid) \
((dbuf)->db.db_object == (obj) && \
(dbuf)->db_objset == (os) && \
(dbuf)->db_blkid == (blkid))
dmu_buf_impl_t *
-dbuf_find(dnode_t *dn, uint8_t level, uint64_t blkid)
+dbuf_find(objset_t *os, uint64_t obj, uint8_t level, uint64_t blkid)
{
dbuf_hash_table_t *h = &dbuf_hash_table;
- objset_impl_t *os = dn->dn_objset;
- uint64_t obj = dn->dn_object;
- uint64_t hv = DBUF_HASH(os, obj, level, blkid);
- uint64_t idx = hv & h->hash_table_mask;
+ 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)) {
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
dbuf_hash_insert(dmu_buf_impl_t *db)
{
dbuf_hash_table_t *h = &dbuf_hash_table;
- objset_impl_t *os = db->db_objset;
+ objset_t *os = db->db_objset;
uint64_t obj = db->db.db_object;
int level = db->db_level;
- uint64_t blkid = db->db_blkid;
- uint64_t hv = DBUF_HASH(os, obj, level, blkid);
- uint64_t idx = hv & h->hash_table_mask;
+ uint64_t blkid, hv, idx;
dmu_buf_impl_t *dbf;
+ 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]; dbf != NULL; dbf = dbf->db_hash_next) {
if (DBUF_EQUAL(dbf, os, obj, level, blkid)) {
db->db_hash_next = h->hash_table[idx];
h->hash_table[idx] = db;
mutex_exit(DBUF_HASH_MUTEX(h, idx));
- atomic_add_64(&dbuf_hash_count, 1);
+ atomic_inc_64(&dbuf_hash_count);
return (NULL);
}
/*
- * Remove an entry from the hash table. This operation will
- * fail if there are any existing holds on the db.
+ * 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 = DBUF_HASH(db->db_objset, db->db.db_object,
- db->db_level, db->db_blkid);
- uint64_t idx = hv & h->hash_table_mask;
+ 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 musn't hold db_mtx to maintin lock ordering:
+ * We mustn't hold db_mtx to maintain lock ordering:
* DBUF_HASH_MUTEX > db_mtx.
*/
ASSERT(refcount_is_zero(&db->db_holds));
*dbp = db->db_hash_next;
db->db_hash_next = NULL;
mutex_exit(DBUF_HASH_MUTEX(h, idx));
- atomic_add_64(&dbuf_hash_count, -1);
+ atomic_dec_64(&dbuf_hash_count);
}
-static arc_evict_func_t dbuf_do_evict;
+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 = 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 (db->db_level != 0 || db->db_evict_func == NULL)
+ if (dbu == NULL)
return;
- if (db->db_user_data_ptr_ptr)
- *db->db_user_data_ptr_ptr = db->db.db_data;
- db->db_evict_func(&db->db, db->db_user_ptr);
- db->db_user_ptr = NULL;
- db->db_user_data_ptr_ptr = NULL;
- db->db_evict_func = NULL;
+ 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);
+ }
}
-void
-dbuf_evict(dmu_buf_impl_t *db)
+boolean_t
+dbuf_is_metadata(dmu_buf_impl_t *db)
{
- ASSERT(MUTEX_HELD(&db->db_mtx));
- ASSERT(db->db_buf == NULL);
- ASSERT(db->db_data_pending == NULL);
+ /*
+ * 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_max_shift);
+}
+
+static inline boolean_t
+dbuf_cache_above_hiwater(void)
+{
+ uint64_t dbuf_cache_target = dbuf_cache_target_bytes();
+
+ uint64_t dbuf_cache_hiwater_bytes =
+ (dbuf_cache_target * dbuf_cache_hiwater_pct) / 100;
+
+ return (refcount_count(&dbuf_cache_size) >
+ dbuf_cache_target + dbuf_cache_hiwater_bytes);
+}
+
+static inline boolean_t
+dbuf_cache_above_lowater(void)
+{
+ uint64_t dbuf_cache_target = dbuf_cache_target_bytes();
+
+ uint64_t dbuf_cache_lowater_bytes =
+ (dbuf_cache_target * dbuf_cache_lowater_pct) / 100;
+
+ return (refcount_count(&dbuf_cache_size) >
+ dbuf_cache_target - 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_cache);
+ multilist_sublist_t *mls = multilist_sublist_lock(dbuf_cache, idx);
+ dmu_buf_impl_t *db;
+ ASSERT(!MUTEX_HELD(&dbuf_evict_lock));
+
+ /*
+ * Set the thread's tsd to indicate that it's processing evictions.
+ * Once a thread stops evicting from the dbuf cache it will
+ * reset its tsd to NULL.
+ */
+ ASSERT3P(tsd_get(zfs_dbuf_evict_key), ==, NULL);
+ (void) tsd_set(zfs_dbuf_evict_key, (void *)B_TRUE);
+
+ 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) refcount_remove_many(&dbuf_cache_size,
+ db->db.db_size, db);
+ dbuf_destroy(db);
+ } else {
+ multilist_sublist_unlock(mls);
+ }
+ (void) tsd_set(zfs_dbuf_evict_key, NULL);
+}
+
+/*
+ * 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.
+ */
+static void
+dbuf_evict_thread(void)
+{
+ 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 use thread specific data to track when a thread has
+ * started processing evictions. 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()<--------+
+ *
+ * The dbuf_eviction_thread will always have its tsd set until
+ * that thread exits. All other threads will only set their tsd
+ * if they are participating in the eviction process. This only
+ * happens if the eviction thread is unable to process evictions
+ * fast enough. To keep the dbuf cache size in check, other threads
+ * can evict from the dbuf cache directly. Those threads will set
+ * their tsd values so that we ensure that they only evict one dbuf
+ * from the dbuf cache.
+ */
+ if (tsd_get(zfs_dbuf_evict_key) != NULL)
+ return;
- dbuf_clear(db);
- dbuf_destroy(db);
+ /*
+ * 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 (refcount_count(&dbuf_cache_size) > dbuf_cache_target_bytes()) {
+ if (dbuf_cache_above_hiwater())
+ dbuf_evict_one();
+ cv_signal(&dbuf_evict_cv);
+ }
}
+
+
void
dbuf_init(void)
{
/*
* The hash table is big enough to fill all of physical memory
- * with an average 4K block size. The table will take up
- * totalmem*sizeof(void*)/4K (i.e. 2MB/GB with 8-byte pointers).
+ * 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 * 4096 < physmem * PAGESIZE)
+ while (hsize * zfs_arc_average_blocksize < physmem * PAGESIZE)
hsize <<= 1;
retry:
h->hash_table_mask = hsize - 1;
+#if defined(_KERNEL) && defined(HAVE_SPL)
+ /*
+ * 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));
goto retry;
}
- dbuf_cache = kmem_cache_create("dmu_buf_impl_t",
+ 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 cache. We cap the size of the
+ * dbuf cache to 1/32nd (default) of the size of the ARC.
+ */
+ dbuf_cache_max_bytes = MIN(dbuf_cache_max_bytes,
+ arc_target_bytes() >> dbuf_cache_max_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);
+
+ dbuf_cache = multilist_create(sizeof (dmu_buf_impl_t),
+ offsetof(dmu_buf_impl_t, db_cache_link),
+ dbuf_cache_multilist_index_func);
+ refcount_create(&dbuf_cache_size);
+
+ tsd_create(&zfs_dbuf_evict_key, NULL);
+ 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);
}
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) && defined(HAVE_SPL)
+ /*
+ * 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 *));
- kmem_cache_destroy(dbuf_cache);
+#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);
+ tsd_destroy(&zfs_dbuf_evict_key);
+
+ mutex_destroy(&dbuf_evict_lock);
+ cv_destroy(&dbuf_evict_cv);
+
+ refcount_destroy(&dbuf_cache_size);
+ multilist_destroy(dbuf_cache);
}
/*
static void
dbuf_verify(dmu_buf_impl_t *db)
{
- dnode_t *dn = db->db_dnode;
+ dnode_t *dn;
+ dbuf_dirty_record_t *dr;
ASSERT(MUTEX_HELD(&db->db_mtx));
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);
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 == DB_BONUS_BLKID ||
- list_head(&dn->dn_dbufs));
+ ASSERT(db->db_blkid == DMU_BONUS_BLKID ||
+ db->db_blkid == DMU_SPILL_BLKID ||
+ !avl_is_empty(&dn->dn_dbufs));
}
- if (db->db_blkid == DB_BONUS_BLKID) {
+ if (db->db_blkid == DMU_BONUS_BLKID) {
ASSERT(dn != NULL);
ASSERT3U(db->db.db_size, >=, dn->dn_bonuslen);
- ASSERT3U(db->db.db_offset, ==, DB_BONUS_BLKID);
+ 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) {
- dbuf_dirty_record_t *dr = db->db_data_pending;
+ dr = db->db_data_pending;
/*
* It should only be modified in syncing context, so
* make sure we only have one copy of the data.
if (db->db_parent == dn->dn_dbuf) {
/* db is pointed to by the dnode */
/* ASSERT3U(db->db_blkid, <, dn->dn_nblkptr); */
- if (db->db.db_object == DMU_META_DNODE_OBJECT)
+ if (DMU_OBJECT_IS_SPECIAL(db->db.db_object))
ASSERT(db->db_parent == NULL);
else
ASSERT(db->db_parent != NULL);
- ASSERT3P(db->db_blkptr, ==,
- &dn->dn_phys->dn_blkptr[db->db_blkid]);
+ 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 */
- int epb = db->db_parent->db.db_size >> SPA_BLKPTRSHIFT;
+ 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);
* have the struct_rwlock. XXX indblksz no longer
* grows. safe to do this now?
*/
- if (RW_WRITE_HELD(&db->db_dnode->dn_struct_rwlock)) {
+ 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.db_data && db->db_blkid != DB_BONUS_BLKID &&
+ (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) {
- uint64_t *buf = db->db.db_data;
- int i;
+ 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);
+ for (i = 0; i < db->db.db_size >> 3; i++) {
+ ASSERT(buf[i] == 0);
+ }
+ } else {
+ int i;
+ 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 (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_update_data(dmu_buf_impl_t *db)
+dbuf_clear_data(dmu_buf_impl_t *db)
{
ASSERT(MUTEX_HELD(&db->db_mtx));
- if (db->db_level == 0 && db->db_user_data_ptr_ptr) {
- ASSERT(!refcount_is_zero(&db->db_holds));
- *db->db_user_data_ptr_ptr = db->db.db_data;
- }
+ 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(db->db_buf == NULL || !arc_has_callback(db->db_buf));
+ ASSERT(buf != NULL);
+
db->db_buf = buf;
- if (buf != NULL) {
- ASSERT(buf->b_data != NULL);
- db->db.db_data = buf->b_data;
- if (!arc_released(buf))
- arc_set_callback(buf, dbuf_do_evict, db);
- dbuf_update_data(db);
+ 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) || 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 {
- dbuf_evict_user(db);
- db->db.db_data = NULL;
- if (db->db_state != DB_NOFILL)
- db->db_state = DB_UNCACHED;
+ 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(dnode_t *dn, uint64_t offset)
+dbuf_whichblock(const dnode_t *dn, const int64_t level, const uint64_t offset)
{
- if (dn->dn_datablkshift) {
- return (offset >> dn->dn_datablkshift);
+ 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);
dbuf_set_data(db, buf);
db->db_state = DB_CACHED;
} else {
- ASSERT(db->db_blkid != DB_BONUS_BLKID);
+ ASSERT(db->db_blkid != DMU_BONUS_BLKID);
ASSERT3P(db->db_buf, ==, NULL);
- VERIFY(arc_buf_remove_ref(buf, db) == 1);
+ arc_buf_destroy(buf, db);
db->db_state = DB_UNCACHED;
}
cv_broadcast(&db->db_changed);
- mutex_exit(&db->db_mtx);
- dbuf_rele(db, NULL);
+ dbuf_rele_and_unlock(db, NULL);
}
-static void
-dbuf_read_impl(dmu_buf_impl_t *db, zio_t *zio, uint32_t *flags)
+static int
+dbuf_read_impl(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags)
{
- dnode_t *dn = db->db_dnode;
- zbookmark_t zb;
- uint32_t aflags = ARC_NOWAIT;
- arc_buf_t *pbuf;
+ dnode_t *dn;
+ zbookmark_phys_t zb;
+ uint32_t aflags = ARC_FLAG_NOWAIT;
+ int err;
+ DB_DNODE_ENTER(db);
+ dn = DB_DNODE(db);
ASSERT(!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(db->db_state == DB_UNCACHED);
ASSERT(db->db_buf == NULL);
- if (db->db_blkid == DB_BONUS_BLKID) {
- int bonuslen = dn->dn_bonuslen;
+ 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);
ASSERT3U(bonuslen, <=, db->db.db_size);
- db->db.db_data = zio_buf_alloc(DN_MAX_BONUSLEN);
- arc_space_consume(DN_MAX_BONUSLEN, ARC_SPACE_OTHER);
- if (bonuslen < DN_MAX_BONUSLEN)
- bzero(db->db.db_data, DN_MAX_BONUSLEN);
- bcopy(DN_BONUS(dn->dn_phys), db->db.db_data,
- bonuslen);
- dbuf_update_data(db);
+ 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;
+ return (0);
}
/*
BP_IS_HOLE(db->db_blkptr)))) {
arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
- dbuf_set_data(db, arc_buf_alloc(dn->dn_objset->os_spa,
- db->db.db_size, db, type));
+ 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;
+ int i;
+ for (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;
- *flags |= DB_RF_CACHED;
mutex_exit(&db->db_mtx);
- return;
+ return (0);
}
+ DB_DNODE_EXIT(db);
+
db->db_state = DB_READ;
mutex_exit(&db->db_mtx);
if (DBUF_IS_L2CACHEABLE(db))
- aflags |= ARC_L2CACHE;
+ aflags |= ARC_FLAG_L2CACHE;
- zb.zb_objset = db->db_objset->os_dsl_dataset ?
- db->db_objset->os_dsl_dataset->ds_object : 0;
- zb.zb_object = db->db.db_object;
- zb.zb_level = db->db_level;
- zb.zb_blkid = db->db_blkid;
+ SET_BOOKMARK(&zb, db->db_objset->os_dsl_dataset ?
+ db->db_objset->os_dsl_dataset->ds_object : DMU_META_OBJSET,
+ db->db.db_object, db->db_level, db->db_blkid);
dbuf_add_ref(db, NULL);
- /* ZIO_FLAG_CANFAIL callers have to check the parent zio's error */
-
- if (db->db_parent)
- pbuf = db->db_parent->db_buf;
- else
- pbuf = db->db_objset->os_phys_buf;
- (void) arc_read(zio, dn->dn_objset->os_spa, db->db_blkptr, pbuf,
+ err = arc_read(zio, db->db_objset->os_spa, db->db_blkptr,
dbuf_read_done, db, ZIO_PRIORITY_SYNC_READ,
- (*flags & DB_RF_CANFAIL) ? ZIO_FLAG_CANFAIL : ZIO_FLAG_MUSTSUCCEED,
+ (flags & DB_RF_CANFAIL) ? ZIO_FLAG_CANFAIL : ZIO_FLAG_MUSTSUCCEED,
&aflags, &zb);
- if (aflags & ARC_CACHED)
- *flags |= DB_RF_CACHED;
+
+ 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.
+ */
+ ASSERT(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 (refcount_count(&db->db_holds) > db->db_dirtycnt) {
+ 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 (compress_type == ZIO_COMPRESS_OFF) {
+ dr->dt.dl.dr_data = arc_alloc_buf(spa, db, type, size);
+ } else {
+ 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);
+ }
+ 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;
- int havepzio = (zio != NULL);
- int prefetch;
+ boolean_t prefetch;
+ dnode_t *dn;
/*
* We don't have to hold the mutex to check db_state because it
ASSERT(!refcount_is_zero(&db->db_holds));
if (db->db_state == DB_NOFILL)
- return (EIO);
+ return (SET_ERROR(EIO));
+ DB_DNODE_ENTER(db);
+ dn = DB_DNODE(db);
if ((flags & DB_RF_HAVESTRUCT) == 0)
- rw_enter(&db->db_dnode->dn_struct_rwlock, RW_READER);
+ rw_enter(&dn->dn_struct_rwlock, RW_READER);
- prefetch = db->db_level == 0 && db->db_blkid != DB_BONUS_BLKID &&
- (flags & DB_RF_NOPREFETCH) == 0 && db->db_dnode != NULL &&
+ 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) {
+ /*
+ * If the arc buf is compressed, we need to decompress it to
+ * read the data. This could happen during the "zfs receive" of
+ * a stream which is compressed and deduplicated.
+ */
+ if (db->db_buf != NULL &&
+ arc_get_compression(db->db_buf) != ZIO_COMPRESS_OFF) {
+ dbuf_fix_old_data(db,
+ spa_syncing_txg(dmu_objset_spa(db->db_objset)));
+ err = arc_decompress(db->db_buf);
+ dbuf_set_data(db, db->db_buf);
+ }
mutex_exit(&db->db_mtx);
if (prefetch)
- dmu_zfetch(&db->db_dnode->dn_zfetch, db->db.db_offset,
- db->db.db_size, TRUE);
+ dmu_zfetch(&dn->dn_zfetch, db->db_blkid, 1, B_TRUE);
if ((flags & DB_RF_HAVESTRUCT) == 0)
- rw_exit(&db->db_dnode->dn_struct_rwlock);
+ rw_exit(&dn->dn_struct_rwlock);
+ DB_DNODE_EXIT(db);
} else if (db->db_state == DB_UNCACHED) {
- if (zio == NULL) {
- zio = zio_root(db->db_dnode->dn_objset->os_spa,
- NULL, NULL, ZIO_FLAG_CANFAIL);
+ 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;
}
- dbuf_read_impl(db, zio, &flags);
+ err = dbuf_read_impl(db, zio, flags);
/* dbuf_read_impl has dropped db_mtx for us */
- if (prefetch)
- dmu_zfetch(&db->db_dnode->dn_zfetch, db->db.db_offset,
- db->db.db_size, flags & DB_RF_CACHED);
+ if (!err && prefetch)
+ dmu_zfetch(&dn->dn_zfetch, db->db_blkid, 1, B_TRUE);
if ((flags & DB_RF_HAVESTRUCT) == 0)
- rw_exit(&db->db_dnode->dn_struct_rwlock);
+ rw_exit(&dn->dn_struct_rwlock);
+ DB_DNODE_EXIT(db);
- if (!havepzio)
+ if (!err && need_wait)
err = 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(&db->db_dnode->dn_zfetch, db->db.db_offset,
- db->db.db_size, TRUE);
+ dmu_zfetch(&dn->dn_zfetch, db->db_blkid, 1, B_TRUE);
if ((flags & DB_RF_HAVESTRUCT) == 0)
- rw_exit(&db->db_dnode->dn_struct_rwlock);
+ rw_exit(&dn->dn_struct_rwlock);
+ DB_DNODE_EXIT(db);
+ /* 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 = EIO;
+ err = SET_ERROR(EIO);
}
mutex_exit(&db->db_mtx);
}
- ASSERT(err || havepzio || db->db_state == DB_CACHED);
return (err);
}
dbuf_noread(dmu_buf_impl_t *db)
{
ASSERT(!refcount_is_zero(&db->db_holds));
- ASSERT(db->db_blkid != DB_BONUS_BLKID);
+ 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_buf_alloc(db->db_dnode->dn_objset->os_spa,
- db->db.db_size, db, type));
+ 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_set_data(db, NULL);
+ dbuf_clear_data(db);
} else {
ASSERT3U(db->db_state, ==, DB_CACHED);
}
mutex_exit(&db->db_mtx);
}
-/*
- * 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 modify them in the current active group.
- *
- * This function is used in two places: when we are dirtying a
- * buffer for the first time in a txg, and when we are freeing
- * a range in a dnode that includes this buffer.
- *
- * 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 == DB_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.
- */
- ASSERT(dr->dr_txg >= txg - 2);
- if (db->db_blkid == DB_BONUS_BLKID) {
- /* Note that the data bufs here are zio_bufs */
- dr->dt.dl.dr_data = zio_buf_alloc(DN_MAX_BONUSLEN);
- arc_space_consume(DN_MAX_BONUSLEN, ARC_SPACE_OTHER);
- bcopy(db->db.db_data, dr->dt.dl.dr_data, DN_MAX_BONUSLEN);
- } else if (refcount_count(&db->db_holds) > db->db_dirtycnt) {
- int size = db->db.db_size;
- arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
- dr->dt.dl.dr_data = arc_buf_alloc(
- db->db_dnode->dn_objset->os_spa, size, db, type);
- bcopy(db->db.db_data, dr->dt.dl.dr_data->b_data, size);
- } else {
- dbuf_set_data(db, NULL);
- }
-}
-
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 == DB_BONUS_BLKID ||
+ 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(&dr->dt.dl.dr_overridden_by)) {
- /* XXX can get silent EIO here */
- (void) dsl_free(NULL,
- spa_get_dsl(db->db_dnode->dn_objset->os_spa),
- txg, &dr->dt.dl.dr_overridden_by, NULL, NULL, ARC_WAIT);
- }
+ 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;
+
/*
* Release the already-written buffer, so we leave it in
* a consistent dirty state. Note that all callers are
/*
* 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. Also, if we happen accross any level-1 dbufs in the
- * range that have not already been marked dirty, mark them dirty so
- * they stay in memory.
+ * empty blocks.
*/
void
-dbuf_free_range(dnode_t *dn, uint64_t start, uint64_t end, dmu_tx_t *tx)
+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;
- int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT;
- uint64_t first_l1 = start >> epbs;
- uint64_t last_l1 = end >> epbs;
+ 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;
- if (end > dn->dn_maxblkid) {
- end = dn->dn_maxblkid;
- last_l1 = end >> epbs;
- }
- dprintf_dnode(dn, "start=%llu end=%llu\n", start, end);
mutex_enter(&dn->dn_dbufs_mtx);
- for (db = list_head(&dn->dn_dbufs); db; db = db_next) {
- db_next = list_next(&dn->dn_dbufs, db);
- ASSERT(db->db_blkid != DB_BONUS_BLKID);
+ db = avl_find(&dn->dn_dbufs, db_search, &where);
+ ASSERT3P(db, ==, NULL);
- if (db->db_level == 1 &&
- db->db_blkid >= first_l1 && db->db_blkid <= last_l1) {
- mutex_enter(&db->db_mtx);
- if (db->db_last_dirty &&
- db->db_last_dirty->dr_txg < txg) {
- dbuf_add_ref(db, FTAG);
- mutex_exit(&db->db_mtx);
- dbuf_will_dirty(db, tx);
- dbuf_rele(db, FTAG);
- } else {
- mutex_exit(&db->db_mtx);
- }
- }
+ db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER);
- if (db->db_level != 0)
- continue;
- dprintf_dbuf(db, "found buf %s\n", "");
- if (db->db_blkid < start || db->db_blkid > end)
- continue;
+ 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 */
- if (dbuf_undirty(db, tx))
+ mutex_enter(&db->db_mtx);
+ if (dbuf_undirty(db, tx)) {
+ /* mutex has been dropped and dbuf destroyed */
continue;
+ }
- mutex_enter(&db->db_mtx);
if (db->db_state == DB_UNCACHED ||
db->db_state == DB_NOFILL ||
db->db_state == DB_EVICTING) {
}
if (refcount_count(&db->db_holds) == 0) {
ASSERT(db->db_buf);
- dbuf_clear(db);
+ dbuf_destroy(db);
continue;
}
/* The dbuf is referenced */
* size to reflect that this buffer may
* contain new data when we sync.
*/
- if (db->db_blkid > dn->dn_maxblkid)
+ if (db->db_blkid != DMU_SPILL_BLKID &&
+ db->db_blkid > dn->dn_maxblkid)
dn->dn_maxblkid = db->db_blkid;
dbuf_unoverride(dr);
} else {
mutex_exit(&db->db_mtx);
}
- mutex_exit(&dn->dn_dbufs_mtx);
-}
-static int
-dbuf_block_freeable(dmu_buf_impl_t *db)
-{
- dsl_dataset_t *ds = db->db_objset->os_dsl_dataset;
- uint64_t birth_txg = 0;
-
- /*
- * We don't need any locking to protect db_blkptr:
- * If it's syncing, then db_last_dirty will be set
- * so we'll ignore db_blkptr.
- */
- ASSERT(MUTEX_HELD(&db->db_mtx));
- if (db->db_last_dirty)
- birth_txg = db->db_last_dirty->dr_txg;
- else if (db->db_blkptr)
- birth_txg = db->db_blkptr->blk_birth;
-
- /* If we don't exist or are in a snapshot, we can't be freed */
- if (birth_txg)
- return (ds == NULL ||
- dsl_dataset_block_freeable(ds, birth_txg));
- else
- return (FALSE);
+ kmem_free(db_search, sizeof (dmu_buf_impl_t));
+ mutex_exit(&dn->dn_dbufs_mtx);
}
void
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 != DB_BONUS_BLKID);
+ 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(&db->db_dnode->dn_struct_rwlock));
+ ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
/*
- * This call to dbuf_will_dirty() with the dn_struct_rwlock held
+ * 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
*/
- dbuf_will_dirty(db, tx);
+ dmu_buf_will_dirty(&db->db, tx);
/* create the data buffer for the new block */
- buf = arc_buf_alloc(db->db_dnode->dn_objset->os_spa, size, db, type);
+ buf = arc_alloc_buf(dn->dn_objset->os_spa, db, type, size);
/* copy old block data to the new block */
obuf = db->db_buf;
mutex_enter(&db->db_mtx);
dbuf_set_data(db, buf);
- VERIFY(arc_buf_remove_ref(obuf, db) == 1);
+ arc_buf_destroy(obuf, db);
db->db.db_size = size;
if (db->db_level == 0) {
}
mutex_exit(&db->db_mtx);
- dnode_willuse_space(db->db_dnode, size-osize, tx);
+ 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 = db->db_dnode;
- objset_impl_t *os = dn->dn_objset;
+ dnode_t *dn;
+ objset_t *os;
dbuf_dirty_record_t **drp, *dr;
int drop_struct_lock = FALSE;
- boolean_t do_free_accounting = B_FALSE;
int txgoff = tx->tx_txg & TXG_MASK;
ASSERT(tx->tx_txg != 0);
ASSERT(!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.
- * XXX We may want to prohibit dirtying in syncing context even
- * if they did pre-dirty.
*/
+#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) ||
- dn->dn_object == DMU_META_DNODE_OBJECT ||
- dn->dn_objset->os_dsl_dataset == NULL ||
- dsl_dir_is_private(dn->dn_objset->os_dsl_dataset->ds_dir));
-
+ 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
* Don't set dirtyctx to SYNC if we're just modifying this as we
* initialize the objset.
*/
- if (dn->dn_dirtyctx == DN_UNDIRTIED &&
- !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_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);
+ }
}
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.
*/
while ((dr = *drp) != NULL && dr->dr_txg > tx->tx_txg)
drp = &dr->dr_next;
if (dr && dr->dr_txg == tx->tx_txg) {
- if (db->db_level == 0 && db->db_blkid != DB_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)
- arc_buf_thaw(db->db_buf);
- }
+ DB_DNODE_EXIT(db);
+
+ dbuf_redirty(dr);
mutex_exit(&db->db_mtx);
return (dr);
}
/*
* Only valid if not already dirty.
*/
- ASSERT(dn->dn_dirtyctx == DN_UNDIRTIED || dn->dn_dirtyctx ==
+ 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);
- 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);
/*
* We should only be dirtying in syncing context if it's the
- * mos, a spa os, or we're initializing the os. 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.
+ * 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.
*/
- ASSERT(!dmu_tx_is_syncing(tx) ||
- os->os_dsl_dataset == NULL ||
- !dsl_dir_is_private(os->os_dsl_dataset->ds_dir) ||
- !BP_IS_HOLE(os->os_rootbp));
+ 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 != DB_BONUS_BLKID) {
- /*
- * Update the accounting.
- * Note: we delay "free accounting" until after we drop
- * the db_mtx. This keeps us from grabbing other locks
- * (and possibly deadlocking) in bp_get_dasize() while
- * also holding the db_mtx.
- */
- dnode_willuse_space(dn, db->db.db_size, tx);
- do_free_accounting = dbuf_block_freeable(db);
+ if (db->db_blkid != DMU_BONUS_BLKID) {
+ dmu_objset_willuse_space(os, db->db.db_size, tx);
}
/*
* 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 == DB_BONUS_BLKID) {
+ 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) {
}
dr->dt.dl.dr_data = data_old;
} else {
- mutex_init(&dr->dt.di.dr_mtx, NULL, MUTEX_DEFAULT, NULL);
+ 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 && os->os_dsl_dataset != NULL)
+ dr->dr_accounted = db->db.db_size;
dr->dr_dbuf = db;
dr->dr_txg = tx->tx_txg;
dr->dr_next = *drp;
* and dbuf_dirty. We win, as though the dbuf_noread() had
* happened after the free.
*/
- if (db->db_level == 0 && db->db_blkid != DB_BONUS_BLKID) {
+ if (db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID &&
+ db->db_blkid != DMU_SPILL_BLKID) {
mutex_enter(&dn->dn_mtx);
- dnode_clear_range(dn, db->db_blkid, 1, tx);
+ 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;
}
mutex_exit(&db->db_mtx);
- if (db->db_blkid == DB_BONUS_BLKID) {
+ 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);
- } else if (do_free_accounting) {
- blkptr_t *bp = db->db_blkptr;
- int64_t willfree = (bp && !BP_IS_HOLE(bp)) ?
- bp_get_dasize(os->os_spa, bp) : db->db.db_size;
- /*
- * This is only a guess -- if the dbuf is dirty
- * in a previous txg, we don't know how much
- * space it will use on disk yet. We should
- * really have the struct_rwlock to access
- * db_blkptr, but since this is just a guess,
- * it's OK if we get an odd answer.
- */
- dnode_willuse_space(dn, -willfree, tx);
}
+ /*
+ * 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) {
dnode_new_blkid(dn, db->db_blkid, tx, drop_struct_lock);
ASSERT(dn->dn_maxblkid >= db->db_blkid);
parent = dbuf_hold_level(dn, db->db_level+1,
db->db_blkid >> epbs, FTAG);
+ ASSERT(parent != NULL);
parent_held = TRUE;
}
if (drop_struct_lock)
dbuf_rele(parent, FTAG);
mutex_enter(&db->db_mtx);
- /* possible race with dbuf_undirty() */
+ /*
+ * 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);
} else {
ASSERT(db->db_level+1 == dn->dn_nlevels);
ASSERT(db->db_blkid < dn->dn_nblkptr);
- ASSERT(db->db_parent == NULL ||
- db->db_parent == db->db_dnode->dn_dbuf);
+ 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);
}
dnode_setdirty(dn, tx);
+ DB_DNODE_EXIT(db);
return (dr);
}
-static int
+/*
+ * 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 = db->db_dnode;
+ dnode_t *dn;
uint64_t txg = tx->tx_txg;
dbuf_dirty_record_t *dr, **drp;
ASSERT(txg != 0);
- ASSERT(db->db_blkid != DB_BONUS_BLKID);
- mutex_enter(&db->db_mtx);
+ /*
+ * 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) {
- mutex_exit(&db->db_mtx);
- return (0);
- }
+ if (dr == NULL || dr->dr_txg < txg)
+ return (B_FALSE);
ASSERT(dr->dr_txg == txg);
+ ASSERT(dr->dr_dbuf == db);
- /*
- * If this buffer is currently held, we cannot undirty
- * it, since one of the current holders may be in the
- * middle of an update. Note that users of dbuf_undirty()
- * should not place a hold on the dbuf before the call.
- */
- if (refcount_count(&db->db_holds) > db->db_dirtycnt) {
- mutex_exit(&db->db_mtx);
- /* Make sure we don't toss this buffer at sync phase */
- mutex_enter(&dn->dn_mtx);
- dnode_clear_range(dn, db->db_blkid, 1, tx);
- mutex_exit(&dn->dn_mtx);
- return (0);
- }
+ 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);
- /* XXX would be nice to fix up dn_towrite_space[] */
+ 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_level+1 == dn->dn_nlevels) {
+ } 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_level == 0) {
- if (db->db_state != DB_NOFILL) {
- dbuf_unoverride(dr);
+ 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)
- VERIFY(arc_buf_remove_ref(dr->dt.dl.dr_data,
- db) == 1);
- }
- } else {
ASSERT(db->db_buf != NULL);
- ASSERT(list_head(&dr->dt.di.dr_children) == NULL);
- mutex_destroy(&dr->dt.di.dr_mtx);
- list_destroy(&dr->dt.di.dr_children);
+ 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 (refcount_remove(&db->db_holds, (void *)(uintptr_t)txg) == 0) {
- arc_buf_t *buf = db->db_buf;
-
- ASSERT(arc_released(buf));
- dbuf_set_data(db, NULL);
- VERIFY(arc_buf_remove_ref(buf, db) == 1);
- dbuf_evict(db);
- return (1);
+ ASSERT(db->db_state == DB_NOFILL || arc_released(db->db_buf));
+ dbuf_destroy(db);
+ return (B_TRUE);
}
- mutex_exit(&db->db_mtx);
- return (0);
+ return (B_FALSE);
}
-#pragma weak dmu_buf_will_dirty = dbuf_will_dirty
void
-dbuf_will_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx)
+dmu_buf_will_dirty(dmu_buf_t *db_fake, dmu_tx_t *tx)
{
+ dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
int rf = DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH;
+ dbuf_dirty_record_t *dr;
ASSERT(tx->tx_txg != 0);
ASSERT(!refcount_is_zero(&db->db_holds));
- if (RW_WRITE_HELD(&db->db_dnode->dn_struct_rwlock))
+ /*
+ * Quick check for dirtyness. 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);
+
+ 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))
rf |= DB_RF_HAVESTRUCT;
+ DB_DNODE_EXIT(db);
(void) dbuf_read(db, NULL, rf);
(void) dbuf_dirty(db, tx);
}
{
dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
- ASSERT(db->db_blkid != DB_BONUS_BLKID);
+ ASSERT(db->db_blkid != DMU_BONUS_BLKID);
ASSERT(tx->tx_txg != 0);
ASSERT(db->db_level == 0);
ASSERT(!refcount_is_zero(&db->db_holds));
if (db->db_state == DB_FILL) {
if (db->db_level == 0 && db->db_freed_in_flight) {
- ASSERT(db->db_blkid != DB_BONUS_BLKID);
+ ASSERT(db->db_blkid != DMU_BONUS_BLKID);
/* we were freed while filling */
/* XXX dbuf_undirty? */
bzero(db->db.db_data, db->db.db_size);
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;
+}
+
/*
- * "Clear" the contents of this dbuf. This will mark the dbuf
- * EVICTING and clear *most* of its references. Unfortunetely,
- * when we are not holding the dn_dbufs_mtx, we can't clear the
- * entry in the dn_dbufs list. We have to wait until dbuf_destroy()
- * in this case. For callers from the DMU we will usually see:
- * dbuf_clear()->arc_buf_evict()->dbuf_do_evict()->dbuf_destroy()
- * For the arc callback, we will usually see:
- * dbuf_do_evict()->dbuf_clear();dbuf_destroy()
- * Sometimes, though, we will get a mix of these two:
- * DMU: dbuf_clear()->arc_buf_evict()
- * ARC: dbuf_do_evict()->dbuf_destroy()
+ * 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_clear(dmu_buf_impl_t *db)
+dbuf_assign_arcbuf(dmu_buf_impl_t *db, arc_buf_t *buf, dmu_tx_t *tx)
+{
+ ASSERT(!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);
+ ASSERT(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 &&
+ refcount_count(&db->db_holds) - 1 > db->db_dirtycnt) {
+ 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 = db->db_dnode;
+ dnode_t *dn;
dmu_buf_impl_t *parent = db->db_parent;
- dmu_buf_impl_t *dndb = dn->dn_dbuf;
- int dbuf_gone = FALSE;
+ dmu_buf_impl_t *dndb;
ASSERT(MUTEX_HELD(&db->db_mtx));
ASSERT(refcount_is_zero(&db->db_holds));
- dbuf_evict_user(db);
+ if (db->db_buf != NULL) {
+ arc_buf_destroy(db->db_buf, db);
+ db->db_buf = NULL;
+ }
- if (db->db_state == DB_CACHED) {
+ if (db->db_blkid == DMU_BONUS_BLKID) {
+ int slots = DB_DNODE(db)->dn_num_slots;
+ int bonuslen = DN_SLOTS_TO_BONUSLEN(slots);
ASSERT(db->db.db_data != NULL);
- if (db->db_blkid == DB_BONUS_BLKID) {
- zio_buf_free(db->db.db_data, DN_MAX_BONUSLEN);
- arc_space_return(DN_MAX_BONUSLEN, ARC_SPACE_OTHER);
- }
- 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)) {
+ multilist_remove(dbuf_cache, db);
+ (void) refcount_remove_many(&dbuf_cache_size,
+ db->db.db_size, db);
+ }
+
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;
- if (db->db_blkid != DB_BONUS_BLKID && MUTEX_HELD(&dn->dn_dbufs_mtx)) {
- list_remove(&dn->dn_dbufs, db);
+ /*
+ * 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(&dn->dn_dbufs_mtx);
+ 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.
+ */
dnode_rele(dn, db);
- db->db_dnode = NULL;
+ db->db_dnode_handle = NULL;
+
+ dbuf_hash_remove(db);
+ } else {
+ DB_DNODE_EXIT(db);
}
- if (db->db_buf)
- dbuf_gone = arc_buf_evict(db->db_buf);
+ ASSERT(refcount_is_zero(&db->db_holds));
+
+ db->db_parent = NULL;
- if (!dbuf_gone)
- mutex_exit(&db->db_mtx);
+ 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);
+ 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 referened from an indirect dbuf,
+ * If this dbuf is referenced from an indirect dbuf,
* decrement the ref count on the indirect dbuf.
*/
if (parent && parent != dndb)
dbuf_rele(parent, db);
}
-static int
+/*
+ * 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 a userused or groupused
+ * 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)
+ dmu_buf_impl_t **parentp, blkptr_t **bpp, struct dbuf_hold_impl_data *dh)
{
int nlevels, epbs;
*parentp = NULL;
*bpp = NULL;
- ASSERT(blkid != DB_BONUS_BLKID);
+ ASSERT(blkid != DMU_BONUS_BLKID);
- if (dn->dn_phys->dn_nlevels == 0)
- nlevels = 1;
- else
- nlevels = dn->dn_phys->dn_nlevels;
+ 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);
+ }
+ nlevels =
+ (dn->dn_phys->dn_nlevels == 0) ? 1 : dn->dn_phys->dn_nlevels;
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 > (dn->dn_phys->dn_maxblkid >> (level * epbs)))) {
+ 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 (ENOENT);
+ return (SET_ERROR(ENOENT));
} else if (level < nlevels-1) {
/* this block is referenced from an indirect block */
- int err = dbuf_hold_impl(dn, level+1,
- blkid >> epbs, fail_sparse, NULL, parentp);
+ int err;
+ if (dh == NULL) {
+ err = dbuf_hold_impl(dn, level+1,
+ blkid >> epbs, fail_sparse, FALSE, NULL, parentp);
+ } else {
+ __dbuf_hold_impl_init(dh + 1, dn, dh->dh_level + 1,
+ blkid >> epbs, fail_sparse, FALSE, NULL,
+ parentp, dh->dh_depth + 1);
+ err = __dbuf_hold_impl(dh + 1);
+ }
if (err)
return (err);
err = dbuf_read(*parentp, NULL,
}
*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 */
dbuf_create(dnode_t *dn, uint8_t level, uint64_t blkid,
dmu_buf_impl_t *parent, blkptr_t *blkptr)
{
- objset_impl_t *os = dn->dn_objset;
+ 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_cache, KM_SLEEP);
+ db = kmem_cache_alloc(dbuf_kmem_cache, KM_SLEEP);
db->db_objset = os;
db->db.db_object = dn->dn_object;
db->db_blkid = blkid;
db->db_last_dirty = NULL;
db->db_dirtycnt = 0;
- db->db_dnode = dn;
+ db->db_dnode_handle = dn->dn_handle;
db->db_parent = parent;
db->db_blkptr = blkptr;
- db->db_user_ptr = NULL;
- db->db_user_data_ptr_ptr = NULL;
- db->db_evict_func = NULL;
- db->db_immediate_evict = 0;
- db->db_freed_in_flight = 0;
+ db->db_user = NULL;
+ db->db_user_immediate_evict = FALSE;
+ db->db_freed_in_flight = FALSE;
+ db->db_pending_evict = FALSE;
- if (blkid == DB_BONUS_BLKID) {
+ if (blkid == DMU_BONUS_BLKID) {
ASSERT3P(parent, ==, dn->dn_dbuf);
- db->db.db_size = DN_MAX_BONUSLEN -
+ 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 = DB_BONUS_BLKID;
+ db->db.db_offset = DMU_BONUS_BLKID;
db->db_state = DB_UNCACHED;
/* the bonus dbuf is not placed in the hash table */
- arc_space_consume(sizeof (dmu_buf_impl_t), ARC_SPACE_OTHER);
+ 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_level ? 1 << dn->dn_indblkshift : dn->dn_datablksz;
db->db.db_size = blocksize;
db->db.db_offset = db->db_blkid * blocksize;
}
db->db_state = DB_EVICTING;
if ((odb = dbuf_hash_insert(db)) != NULL) {
/* someone else inserted it first */
- kmem_cache_free(dbuf_cache, db);
+ kmem_cache_free(dbuf_kmem_cache, db);
mutex_exit(&dn->dn_dbufs_mtx);
return (odb);
}
- list_insert_head(&dn->dn_dbufs, db);
+ avl_add(&dn->dn_dbufs, db);
+
db->db_state = DB_UNCACHED;
mutex_exit(&dn->dn_dbufs_mtx);
- arc_space_consume(sizeof (dmu_buf_impl_t), ARC_SPACE_OTHER);
+ 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 ||
refcount_count(&dn->dn_holds) > 0);
(void) refcount_add(&dn->dn_holds, db);
+ atomic_inc_32(&dn->dn_dbufs_count);
dprintf_dbuf(db, "db=%p\n", db);
return (db);
}
-static int
-dbuf_do_evict(void *private)
-{
- arc_buf_t *buf = private;
- dmu_buf_impl_t *db = buf->b_private;
+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;
- if (!MUTEX_HELD(&db->db_mtx))
- mutex_enter(&db->db_mtx);
+/*
+ * Actually issue the prefetch read for the block given.
+ */
+static void
+dbuf_issue_final_prefetch(dbuf_prefetch_arg_t *dpa, blkptr_t *bp)
+{
+ arc_flags_t aflags;
+ if (BP_IS_HOLE(bp) || BP_IS_EMBEDDED(bp))
+ return;
- ASSERT(refcount_is_zero(&db->db_holds));
+ aflags = dpa->dpa_aflags | ARC_FLAG_NOWAIT | ARC_FLAG_PREFETCH;
- if (db->db_state != DB_EVICTING) {
- ASSERT(db->db_state == DB_CACHED);
- DBUF_VERIFY(db);
- db->db_buf = NULL;
- dbuf_evict(db);
- } else {
- mutex_exit(&db->db_mtx);
- dbuf_destroy(db);
- }
- return (0);
+ 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_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
+ &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_destroy(dmu_buf_impl_t *db)
+dbuf_prefetch_indirect_done(zio_t *zio, arc_buf_t *abuf, void *private)
{
- ASSERT(refcount_is_zero(&db->db_holds));
-
- if (db->db_blkid != DB_BONUS_BLKID) {
- /*
- * If this dbuf is still on the dn_dbufs list,
- * remove it from that list.
- */
- if (db->db_dnode) {
- dnode_t *dn = db->db_dnode;
+ dbuf_prefetch_arg_t *dpa = private;
+ uint64_t nextblkid;
+ blkptr_t *bp;
- mutex_enter(&dn->dn_dbufs_mtx);
- list_remove(&dn->dn_dbufs, db);
- mutex_exit(&dn->dn_dbufs_mtx);
+ ASSERT3S(dpa->dpa_zb.zb_level, <, dpa->dpa_curlevel);
+ ASSERT3S(dpa->dpa_curlevel, >, 0);
- dnode_rele(dn, db);
- db->db_dnode = NULL;
+ /*
+ * 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) {
+ ASSERT3U(BP_GET_PSIZE(zio->io_bp), ==, zio->io_size);
+ } else {
+ ASSERT3U(BP_GET_LSIZE(zio->io_bp), ==, zio->io_size);
}
- dbuf_hash_remove(db);
- }
- db->db_parent = NULL;
- db->db_buf = NULL;
+ 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);
+ (void) dbuf_read(db, NULL,
+ DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH | DB_RF_HAVESTRUCT);
+ dbuf_rele(db, FTAG);
+ }
+
+ dpa->dpa_curlevel--;
+
+ nextblkid = dpa->dpa_zb.zb_blkid >>
+ (dpa->dpa_epbs * (dpa->dpa_curlevel - dpa->dpa_zb.zb_level));
+ bp = ((blkptr_t *)abuf->b_data) +
+ P2PHASE(nextblkid, 1ULL << dpa->dpa_epbs);
+ if (BP_IS_HOLE(bp) || (zio != NULL && zio->io_error != 0)) {
+ 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;
- ASSERT(!list_link_active(&db->db_link));
- ASSERT(db->db.db_data == NULL);
- ASSERT(db->db_hash_next == NULL);
- ASSERT(db->db_blkptr == NULL);
- ASSERT(db->db_data_pending == NULL);
+ /* 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);
- kmem_cache_free(dbuf_cache, db);
- arc_space_return(sizeof (dmu_buf_impl_t), ARC_SPACE_OTHER);
+ (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.
+ */
void
-dbuf_prefetch(dnode_t *dn, uint64_t blkid)
+dbuf_prefetch(dnode_t *dn, int64_t level, uint64_t blkid, zio_priority_t prio,
+ arc_flags_t aflags)
{
- dmu_buf_impl_t *db = NULL;
- blkptr_t *bp = NULL;
+ blkptr_t bp;
+ int epbs, nlevels, curlevel;
+ uint64_t curblkid;
+ dmu_buf_impl_t *db;
+ zio_t *pio;
+ dbuf_prefetch_arg_t *dpa;
+ dsl_dataset_t *ds;
- ASSERT(blkid != DB_BONUS_BLKID);
+ 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;
- /* dbuf_find() returns with db_mtx held */
- if (db = dbuf_find(dn, 0, blkid)) {
- if (refcount_count(&db->db_holds) > 0) {
- /*
- * This dbuf is active. We assume that it is
- * already CACHED, or else about to be either
- * read or filled.
- */
- mutex_exit(&db->db_mtx);
- 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;
+
+ db = dbuf_find(dn->dn_objset, dn->dn_object,
+ level, blkid);
+ if (db != NULL) {
mutex_exit(&db->db_mtx);
- db = NULL;
- }
-
- if (dbuf_findbp(dn, 0, blkid, TRUE, &db, &bp) == 0) {
- if (bp && !BP_IS_HOLE(bp)) {
- arc_buf_t *pbuf;
- uint32_t aflags = ARC_NOWAIT | ARC_PREFETCH;
- zbookmark_t zb;
- zb.zb_objset = dn->dn_objset->os_dsl_dataset ?
- dn->dn_objset->os_dsl_dataset->ds_object : 0;
- zb.zb_object = dn->dn_object;
- zb.zb_level = 0;
- zb.zb_blkid = blkid;
-
- if (db)
- pbuf = db->db_buf;
- else
- pbuf = dn->dn_objset->os_phys_buf;
+ /*
+ * This dbuf already exists. It is either CACHED, or
+ * (we assume) about to be read or filled.
+ */
+ return;
+ }
- (void) arc_read(NULL, dn->dn_objset->os_spa,
- bp, pbuf, NULL, NULL, ZIO_PRIORITY_ASYNC_READ,
- ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
- &aflags, &zb);
+ /*
+ * 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;
}
- if (db)
- dbuf_rele(db, NULL);
+
+ 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));
+
+ pio = zio_root(dmu_objset_spa(dn->dn_objset), NULL, NULL,
+ ZIO_FLAG_CANFAIL);
+
+ dpa = kmem_zalloc(sizeof (*dpa), KM_SLEEP);
+ 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() to copy a buffer. Handles
+ * the case of 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().
+ */
+noinline static void
+dbuf_hold_copy(struct dbuf_hold_impl_data *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 (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.
*/
-int
-dbuf_hold_impl(dnode_t *dn, uint8_t level, uint64_t blkid, int fail_sparse,
- void *tag, dmu_buf_impl_t **dbp)
+static int
+__dbuf_hold_impl(struct dbuf_hold_impl_data *dh)
{
- dmu_buf_impl_t *db, *parent = NULL;
-
- ASSERT(blkid != DB_BONUS_BLKID);
- ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
- ASSERT3U(dn->dn_nlevels, >, level);
+ ASSERT3S(dh->dh_depth, <, DBUF_HOLD_IMPL_MAX_DEPTH);
+ dh->dh_parent = NULL;
- *dbp = NULL;
-top:
- /* dbuf_find() returns with db_mtx held */
- db = dbuf_find(dn, level, blkid);
+ 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);
- if (db == NULL) {
- blkptr_t *bp = NULL;
- int err;
+ *(dh->dh_dbp) = NULL;
- ASSERT3P(parent, ==, NULL);
- err = dbuf_findbp(dn, level, blkid, fail_sparse, &parent, &bp);
- if (fail_sparse) {
- if (err == 0 && bp && BP_IS_HOLE(bp))
- err = ENOENT;
- if (err) {
- if (parent)
- dbuf_rele(parent, NULL);
- return (err);
+ /* 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, dh);
+ 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 (err && err != ENOENT)
- return (err);
- db = dbuf_create(dn, level, blkid, parent, bp);
+ 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 (db->db_buf && refcount_is_zero(&db->db_holds)) {
- arc_buf_add_ref(db->db_buf, db);
- if (db->db_buf->b_data == NULL) {
- dbuf_clear(db);
- if (parent) {
- dbuf_rele(parent, NULL);
- parent = NULL;
- }
- goto top;
- }
- ASSERT3P(db->db.db_data, ==, db->db_buf->b_data);
+ if (dh->dh_fail_uncached && dh->dh_db->db_state != DB_CACHED) {
+ mutex_exit(&dh->dh_db->db_mtx);
+ return (SET_ERROR(ENOENT));
}
- ASSERT(db->db_buf == NULL || arc_referenced(db->db_buf));
+ 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 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 (db->db_level == 0 && db->db_blkid != DB_BONUS_BLKID &&
- dn->dn_object != DMU_META_DNODE_OBJECT &&
- db->db_state == DB_CACHED && db->db_data_pending) {
- dbuf_dirty_record_t *dr = db->db_data_pending;
-
- if (dr->dt.dl.dr_data == db->db_buf) {
- arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
-
- dbuf_set_data(db,
- arc_buf_alloc(db->db_dnode->dn_objset->os_spa,
- db->db.db_size, db, type));
- bcopy(dr->dt.dl.dr_data->b_data, db->db.db_data,
- db->db.db_size);
- }
+ 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);
}
- (void) refcount_add(&db->db_holds, tag);
- dbuf_update_data(db);
- DBUF_VERIFY(db);
- mutex_exit(&db->db_mtx);
+ if (multilist_link_active(&dh->dh_db->db_cache_link)) {
+ ASSERT(refcount_is_zero(&dh->dh_db->db_holds));
+ multilist_remove(dbuf_cache, dh->dh_db);
+ (void) refcount_remove_many(&dbuf_cache_size,
+ dh->dh_db->db.db_size, dh->dh_db);
+ }
+ (void) 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 (parent)
- dbuf_rele(parent, NULL);
+ if (dh->dh_parent)
+ dbuf_rele(dh->dh_parent, NULL);
- ASSERT3P(db->db_dnode, ==, dn);
- ASSERT3U(db->db_blkid, ==, blkid);
- ASSERT3U(db->db_level, ==, level);
- *dbp = db;
+ 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);
}
+/*
+ * The following code preserves the recursive function dbuf_hold_impl()
+ * but moves the local variables AND function arguments to the heap to
+ * minimize the stack frame size. Enough space is initially allocated
+ * on the stack for 20 levels of recursion.
+ */
+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)
+{
+ struct dbuf_hold_impl_data *dh;
+ int error;
+
+ dh = kmem_alloc(sizeof (struct dbuf_hold_impl_data) *
+ DBUF_HOLD_IMPL_MAX_DEPTH, KM_SLEEP);
+ __dbuf_hold_impl_init(dh, dn, level, blkid, fail_sparse,
+ fail_uncached, tag, dbp, 0);
+
+ error = __dbuf_hold_impl(dh);
+
+ kmem_free(dh, sizeof (struct dbuf_hold_impl_data) *
+ DBUF_HOLD_IMPL_MAX_DEPTH);
+
+ return (error);
+}
+
+static void
+__dbuf_hold_impl_init(struct dbuf_hold_impl_data *dh,
+ dnode_t *dn, uint8_t level, uint64_t blkid,
+ boolean_t fail_sparse, boolean_t fail_uncached,
+ void *tag, dmu_buf_impl_t **dbp, int depth)
+{
+ 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;
+
+ dh->dh_depth = depth;
+}
+
dmu_buf_impl_t *
dbuf_hold(dnode_t *dn, uint64_t blkid, void *tag)
{
- dmu_buf_impl_t *db;
- int err = dbuf_hold_impl(dn, 0, blkid, FALSE, tag, &db);
- return (err ? NULL : db);
+ 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, tag, &db);
+ int err = dbuf_hold_impl(dn, level, blkid, FALSE, FALSE, tag, &db);
return (err ? NULL : db);
}
ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
ASSERT(dn->dn_bonus == NULL);
- dn->dn_bonus = dbuf_create(dn, 0, DB_BONUS_BLKID, dn->dn_dbuf, 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
dbuf_add_ref(dmu_buf_impl_t *db, void *tag)
{
int64_t holds = refcount_add(&db->db_holds, tag);
- ASSERT(holds > 1);
+ 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) refcount_add(&db->db_holds, tag);
+ result = B_TRUE;
+ }
+ mutex_exit(&found_db->db_mtx);
+ }
+ return (result);
}
-#pragma weak dmu_buf_rele = dbuf_rele
+/*
+ * 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);
+}
+
+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.
+ */
+void
+dbuf_rele_and_unlock(dmu_buf_impl_t *db, void *tag)
{
int64_t holds;
- mutex_enter(&db->db_mtx);
+ 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 = 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 && holds == (db->db_level == 0 ? db->db_dirtycnt : 0))
+ 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_immediate_evict)
+ db->db_level == 0 && db->db_user_immediate_evict)
dbuf_evict_user(db);
if (holds == 0) {
- if (db->db_blkid == DB_BONUS_BLKID) {
+ 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);
- dnode_rele(db->db_dnode, db);
+
+ 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
*/
ASSERT(db->db_state == DB_UNCACHED ||
db->db_state == DB_NOFILL);
- dbuf_evict(db);
+ dbuf_destroy(db);
} else if (arc_released(db->db_buf)) {
- arc_buf_t *buf = db->db_buf;
/*
* This dbuf has anonymous data associated with it.
*/
- dbuf_set_data(db, NULL);
- VERIFY(arc_buf_remove_ref(buf, db) == 1);
- dbuf_evict(db);
+ dbuf_destroy(db);
} else {
- VERIFY(arc_buf_remove_ref(db->db_buf, db) == 0);
- if (!DBUF_IS_CACHEABLE(db))
- dbuf_clear(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)) {
+ multilist_insert(dbuf_cache, db);
+ (void) refcount_add_many(&dbuf_cache_size,
+ db->db.db_size, db);
mutex_exit(&db->db_mtx);
+
+ dbuf_evict_notify();
+ }
+
+ if (do_arc_evict)
+ arc_freed(spa, &bp);
}
} else {
mutex_exit(&db->db_mtx);
}
+
}
#pragma weak dmu_buf_refcount = dbuf_refcount
}
void *
-dmu_buf_set_user(dmu_buf_t *db_fake, void *user_ptr, void *user_data_ptr_ptr,
- dmu_buf_evict_func_t *evict_func)
+dmu_buf_replace_user(dmu_buf_t *db_fake, dmu_buf_user_t *old_user,
+ dmu_buf_user_t *new_user)
{
- return (dmu_buf_update_user(db_fake, NULL, user_ptr,
- user_data_ptr_ptr, evict_func));
+ 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_ie(dmu_buf_t *db_fake, void *user_ptr, void *user_data_ptr_ptr,
- dmu_buf_evict_func_t *evict_func)
+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_immediate_evict = TRUE;
- return (dmu_buf_update_user(db_fake, NULL, user_ptr,
- user_data_ptr_ptr, evict_func));
+ db->db_user_immediate_evict = TRUE;
+ return (dmu_buf_set_user(db_fake, user));
}
void *
-dmu_buf_update_user(dmu_buf_t *db_fake, void *old_user_ptr, void *user_ptr,
- void *user_data_ptr_ptr, dmu_buf_evict_func_t *evict_func)
+dmu_buf_remove_user(dmu_buf_t *db_fake, dmu_buf_user_t *user)
{
- dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
- ASSERT(db->db_level == 0);
+ return (dmu_buf_replace_user(db_fake, user, NULL));
+}
- ASSERT((user_ptr == NULL) == (evict_func == NULL));
+void *
+dmu_buf_get_user(dmu_buf_t *db_fake)
+{
+ dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
- mutex_enter(&db->db_mtx);
+ dbuf_verify_user(db, DBVU_NOT_EVICTING);
+ return (db->db_user);
+}
- if (db->db_user_ptr == old_user_ptr) {
- db->db_user_ptr = user_ptr;
- db->db_user_data_ptr_ptr = user_data_ptr_ptr;
- db->db_evict_func = evict_func;
+void
+dmu_buf_user_evict_wait()
+{
+ taskq_wait(dbu_evict_taskq);
+}
- dbuf_update_data(db);
- } else {
- old_user_ptr = db->db_user_ptr;
- }
+blkptr_t *
+dmu_buf_get_blkptr(dmu_buf_t *db)
+{
+ dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
+ return (dbi->db_blkptr);
+}
- mutex_exit(&db->db_mtx);
- return (old_user_ptr);
+objset_t *
+dmu_buf_get_objset(dmu_buf_t *db)
+{
+ dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
+ return (dbi->db_objset);
}
-void *
-dmu_buf_get_user(dmu_buf_t *db_fake)
+dnode_t *
+dmu_buf_dnode_enter(dmu_buf_t *db)
{
- dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake;
- ASSERT(!refcount_is_zero(&db->db_holds));
+ dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
+ DB_DNODE_ENTER(dbi);
+ return (DB_DNODE(dbi));
+}
- return (db->db_user_ptr);
+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
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
if (parent == NULL) {
mutex_exit(&db->db_mtx);
rw_enter(&dn->dn_struct_rwlock, RW_READER);
- (void) dbuf_hold_impl(dn, db->db_level+1,
- db->db_blkid >> epbs, FALSE, db, &parent);
+ 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;
}
}
-static void
+/*
+ * 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 = db->db_dnode;
+ dnode_t *dn;
zio_t *zio;
ASSERT(dmu_tx_is_syncing(tx));
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);
- ASSERT3U(db->db.db_size, ==, 1<<dn->dn_phys->dn_indblkshift);
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);
zio = dr->dr_zio;
mutex_enter(&dr->dt.di.dr_mtx);
- dbuf_sync_list(&dr->dt.di.dr_children, tx);
+ 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);
}
-static void
+/*
+ * 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 = db->db_dnode;
- objset_impl_t *os = dn->dn_objset;
+ dnode_t *dn;
+ objset_t *os;
uint64_t txg = tx->tx_txg;
- int blksz;
ASSERT(dmu_tx_is_syncing(tx));
}
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 == DB_BONUS_BLKID) {
+ if (db->db_blkid == DMU_BONUS_BLKID) {
dbuf_dirty_record_t **drp;
ASSERT(*datap != NULL);
- ASSERT3U(db->db_level, ==, 0);
- ASSERT3U(dn->dn_phys->dn_bonuslen, <=, DN_MAX_BONUSLEN);
+ ASSERT0(db->db_level);
+ ASSERT3U(dn->dn_phys->dn_bonuslen, <=,
+ DN_SLOTS_TO_BONUSLEN(dn->dn_phys->dn_extra_slots + 1));
bcopy(*datap, DN_BONUS(dn->dn_phys), dn->dn_phys->dn_bonuslen);
+ DB_DNODE_EXIT(db);
+
if (*datap != db->db.db_data) {
- zio_buf_free(*datap, DN_MAX_BONUSLEN);
- arc_space_return(DN_MAX_BONUSLEN, ARC_SPACE_OTHER);
+ 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;
- mutex_exit(&db->db_mtx);
- dbuf_rele(db, (void *)(uintptr_t)txg);
+ dbuf_rele_and_unlock(db, (void *)(uintptr_t)txg);
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
dbuf_check_blkptr(dn, db);
/*
- * If this buffer is in the middle of an immdiate write,
+ * 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(dr->dt.dl.dr_override_state != DR_NOT_OVERRIDDEN);
}
- /*
- * If this dbuf has already been written out via an immediate write,
- * just complete the write by copying over the new block pointer and
- * updating the accounting via the write-completion functions.
- */
- if (dr->dt.dl.dr_override_state == DR_OVERRIDDEN) {
- zio_t zio_fake;
-
- zio_fake.io_private = &db;
- zio_fake.io_error = 0;
- zio_fake.io_bp = db->db_blkptr;
- zio_fake.io_bp_orig = *db->db_blkptr;
- zio_fake.io_txg = txg;
- zio_fake.io_flags = 0;
-
- *db->db_blkptr = dr->dt.dl.dr_overridden_by;
- dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN;
- db->db_data_pending = dr;
- dr->dr_zio = &zio_fake;
- mutex_exit(&db->db_mtx);
-
- ASSERT(!DVA_EQUAL(BP_IDENTITY(zio_fake.io_bp),
- BP_IDENTITY(&zio_fake.io_bp_orig)) ||
- BP_IS_HOLE(zio_fake.io_bp));
-
- if (BP_IS_OLDER(&zio_fake.io_bp_orig, txg))
- (void) dsl_dataset_block_kill(os->os_dsl_dataset,
- &zio_fake.io_bp_orig, dn->dn_zio, tx);
-
- dbuf_write_ready(&zio_fake, db->db_buf, db);
- dbuf_write_done(&zio_fake, db->db_buf, db);
-
- return;
- }
-
- if (db->db_state != DB_NOFILL) {
- blksz = arc_buf_size(*datap);
+ if (db->db_state != DB_NOFILL &&
+ dn->dn_object != DMU_META_DNODE_OBJECT &&
+ 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);
+ arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
+ enum zio_compress compress_type = arc_get_compression(*datap);
- if (dn->dn_object != DMU_META_DNODE_OBJECT) {
- /*
- * 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).
- */
- if (refcount_count(&db->db_holds) > 1 &&
- *datap == db->db_buf) {
- arc_buf_contents_t type =
- DBUF_GET_BUFC_TYPE(db);
- *datap =
- arc_buf_alloc(os->os_spa, blksz, db, type);
- bcopy(db->db.db_data, (*datap)->b_data, blksz);
- }
+ if (compress_type == ZIO_COMPRESS_OFF) {
+ *datap = arc_alloc_buf(os->os_spa, db, type, psize);
+ } else {
+ ASSERT3U(type, ==, ARC_BUFC_DATA);
+ int lsize = arc_buf_lsize(*datap);
+ *datap = arc_alloc_compressed_buf(os->os_spa, db,
+ psize, lsize, compress_type);
}
-
- ASSERT(*datap != NULL);
+ bcopy(db->db.db_data, (*datap)->b_data, psize);
}
db->db_data_pending = dr;
dbuf_write(dr, *datap, tx);
ASSERT(!list_link_active(&dr->dr_dirty_node));
- if (dn->dn_object == DMU_META_DNODE_OBJECT)
+ if (dn->dn_object == DMU_META_DNODE_OBJECT) {
list_insert_tail(&dn->dn_dirty_records[txg&TXG_MASK], dr);
- else
+ 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, dmu_tx_t *tx)
+dbuf_sync_list(list_t *list, int level, dmu_tx_t *tx)
{
dbuf_dirty_record_t *dr;
- while (dr = list_head(list)) {
+ while ((dr = list_head(list))) {
if (dr->dr_zio != NULL) {
/*
* If we find an already initialized zio then we
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);
}
}
-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 = db->db_dnode;
- objset_impl_t *os = dn->dn_objset;
- dmu_buf_impl_t *parent = db->db_parent;
- uint64_t txg = tx->tx_txg;
- zbookmark_t zb;
- writeprops_t wp = { 0 };
- zio_t *zio;
-
- if (!BP_IS_HOLE(db->db_blkptr) &&
- (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.
- */
- arc_release(data, db);
- } else if (db->db_state != DB_NOFILL) {
- ASSERT(arc_released(data));
- /* XXX why do we need to thaw here? */
- arc_buf_thaw(data);
- }
-
- if (parent != dn->dn_dbuf) {
- ASSERT(parent && parent->db_data_pending);
- ASSERT(db->db_level == parent->db_level-1);
- ASSERT(arc_released(parent->db_buf));
- zio = parent->db_data_pending->dr_zio;
- } else {
- ASSERT(db->db_level == dn->dn_phys->dn_nlevels-1);
- 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);
-
- zb.zb_objset = os->os_dsl_dataset ? os->os_dsl_dataset->ds_object : 0;
- zb.zb_object = db->db.db_object;
- zb.zb_level = db->db_level;
- zb.zb_blkid = db->db_blkid;
-
- wp.wp_type = dn->dn_type;
- wp.wp_level = db->db_level;
- wp.wp_copies = os->os_copies;
- wp.wp_dncompress = dn->dn_compress;
- wp.wp_oscompress = os->os_compress;
- wp.wp_dnchecksum = dn->dn_checksum;
- wp.wp_oschecksum = os->os_checksum;
-
- if (BP_IS_OLDER(db->db_blkptr, txg))
- (void) dsl_dataset_block_kill(
- os->os_dsl_dataset, db->db_blkptr, zio, tx);
-
- if (db->db_state == DB_NOFILL) {
- zio_prop_t zp = { 0 };
-
- write_policy(os->os_spa, &wp, &zp);
- dr->dr_zio = zio_write(zio, os->os_spa,
- txg, db->db_blkptr, NULL,
- db->db.db_size, &zp, dbuf_skip_write_ready,
- dbuf_skip_write_done, db, ZIO_PRIORITY_ASYNC_WRITE,
- ZIO_FLAG_MUSTSUCCEED, &zb);
- } else {
- dr->dr_zio = arc_write(zio, os->os_spa, &wp,
- DBUF_IS_L2CACHEABLE(db), txg, db->db_blkptr,
- data, dbuf_write_ready, dbuf_write_done, db,
- ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_MUSTSUCCEED, &zb);
- }
-}
-
-/* wrapper function for dbuf_write_ready bypassing ARC */
-static void
-dbuf_skip_write_ready(zio_t *zio)
-{
- blkptr_t *bp = zio->io_bp;
-
- if (!BP_IS_GANG(bp))
- zio_skip_write(zio);
-
- dbuf_write_ready(zio, NULL, zio->io_private);
-}
-
-/* wrapper function for dbuf_write_done bypassing ARC */
-static void
-dbuf_skip_write_done(zio_t *zio)
-{
- dbuf_write_done(zio, NULL, zio->io_private);
-}
-
/* ARGSUSED */
static void
dbuf_write_ready(zio_t *zio, arc_buf_t *buf, void *vdb)
{
dmu_buf_impl_t *db = vdb;
- dnode_t *dn = db->db_dnode;
- objset_impl_t *os = dn->dn_objset;
+ 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 old_size, new_size, i;
-
- ASSERT(db->db_blkptr == bp);
-
- dprintf_dbuf_bp(db, bp_orig, "bp_orig: %s", "");
-
- old_size = bp_get_dasize(os->os_spa, bp_orig);
- new_size = bp_get_dasize(os->os_spa, bp);
+ int i;
- dnode_diduse_space(dn, new_size - old_size);
+ ASSERT3P(db->db_blkptr, !=, NULL);
+ ASSERT3P(&db->db_data_pending->dr_bp_copy, ==, bp);
- if (BP_IS_HOLE(bp)) {
- dsl_dataset_t *ds = os->os_dsl_dataset;
- dmu_tx_t *tx = os->os_synctx;
+ 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_orig->blk_birth == tx->tx_txg)
- (void) dsl_dataset_block_kill(ds, bp_orig, zio, tx);
- ASSERT3U(bp->blk_fill, ==, 0);
- return;
+ 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);
}
- ASSERT(BP_GET_TYPE(bp) == dn->dn_type);
- 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)
+ if (db->db_blkid > dn->dn_phys->dn_maxblkid &&
+ db->db_blkid != DMU_SPILL_BLKID)
dn->dn_phys->dn_maxblkid = db->db_blkid;
mutex_exit(&dn->dn_mtx);
if (dn->dn_type == DMU_OT_DNODE) {
- dnode_phys_t *dnp = db->db.db_data;
- for (i = db->db.db_size >> DNODE_SHIFT; i > 0;
- i--, dnp++) {
- if (dnp->dn_type != DMU_OT_NONE)
+ 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 {
- fill = 1;
+ if (BP_IS_HOLE(bp)) {
+ fill = 0;
+ } else {
+ fill = 1;
+ }
}
} else {
blkptr_t *ibp = db->db.db_data;
for (i = db->db.db_size >> SPA_BLKPTRSHIFT; i > 0; i--, ibp++) {
if (BP_IS_HOLE(ibp))
continue;
- ASSERT3U(BP_GET_LSIZE(ibp), ==,
- db->db_level == 1 ? dn->dn_datablksz :
- (1<<dn->dn_phys->dn_indblkshift));
- fill += ibp->blk_fill;
+ fill += BP_GET_FILL(ibp);
}
}
+ DB_DNODE_EXIT(db);
- bp->blk_fill = fill;
+ if (!BP_IS_EMBEDDED(bp))
+ bp->blk_fill = fill;
mutex_exit(&db->db_mtx);
- if (zio->io_flags & ZIO_FLAG_IO_REWRITE) {
- ASSERT(DVA_EQUAL(BP_IDENTITY(bp), BP_IDENTITY(bp_orig)));
- } else {
- dsl_dataset_t *ds = os->os_dsl_dataset;
- dmu_tx_t *tx = os->os_synctx;
+ rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
+ *db->db_blkptr = *bp;
+ rw_exit(&dn->dn_struct_rwlock);
+}
- if (bp_orig->blk_birth == tx->tx_txg)
- (void) dsl_dataset_block_kill(ds, bp_orig, zio, tx);
- dsl_dataset_block_born(ds, bp, tx);
+/* 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 dsl_pool_sync()'s call to
+ * dsl_pool_undirty_space().
+ */
+ delta = dr->dr_accounted / zio->io_phys_children;
+ dsl_pool_undirty_space(dp, delta, zio->io_txg);
}
/* ARGSUSED */
dbuf_write_done(zio_t *zio, arc_buf_t *buf, void *vdb)
{
dmu_buf_impl_t *db = vdb;
- uint64_t txg = zio->io_txg;
+ 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;
- ASSERT3U(zio->io_error, ==, 0);
+ 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_txg == txg);
+ 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 != DB_BONUS_BLKID);
+ 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)
- VERIFY(arc_buf_remove_ref(dr->dt.dl.dr_data,
- db) == 1);
- else if (!BP_IS_HOLE(db->db_blkptr))
- arc_set_callback(db->db_buf, dbuf_do_evict, db);
- else
- ASSERT(arc_released(db->db_buf));
+ arc_buf_destroy(dr->dt.dl.dr_data, db);
}
} else {
- dnode_t *dn = db->db_dnode;
+ 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);
+ ASSERT3U(db->db.db_size, ==, 1 << dn->dn_phys->dn_indblkshift);
if (!BP_IS_HOLE(db->db_blkptr)) {
- int epbs =
- dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
+ 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);
- ASSERT3U(dn->dn_phys->dn_maxblkid
- >> (db->db_level * epbs), >=, db->db_blkid);
- arc_set_callback(db->db_buf, dbuf_do_evict, db);
}
+ DB_DNODE_EXIT(db);
mutex_destroy(&dr->dt.di.dr_mtx);
list_destroy(&dr->dt.di.dr_children);
}
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);
+}
+
+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);
- dprintf_dbuf_bp(db, zio->io_bp, "bp: %s", "");
+ dbuf_write_done(zio, NULL, db);
- dbuf_rele(db, (void *)(uintptr_t)txg);
+ if (zio->io_abd != NULL)
+ abd_put(zio->io_abd);
}
+
+/* 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);
+ }
+ }
+ }
+
+ 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 {
+ arc_done_func_t *children_ready_cb = NULL;
+ 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.
+ */
+ 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) && defined(HAVE_SPL)
+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_will_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_cache_max_shift, int, 0644);
+MODULE_PARM_DESC(dbuf_cache_max_shift,
+ "Cap the size of the dbuf cache to a log2 fraction of arc size.");
+/* END CSTYLED */
+#endif