/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
* Copyright 2011 Nexenta Systems, Inc. All rights reserved.
- * Copyright (c) 2012, 2015 by Delphix. 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/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;
- int dh_fail_sparse;
+ boolean_t dh_fail_sparse;
+ boolean_t dh_fail_uncached;
void *dh_tag;
dmu_buf_impl_t **dh_dbp;
/* Local variables */
};
static void __dbuf_hold_impl_init(struct dbuf_hold_impl_data *dh,
- dnode_t *dn, uint8_t level, uint64_t blkid, int fail_sparse,
- void *tag, dmu_buf_impl_t **dbp, int depth);
+ 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);
-/*
- * Number of times that zfs_free_range() took the slow path while doing
- * a zfs receive. A nonzero value indicates a potential performance problem.
- */
-uint64_t zfs_free_range_recv_miss;
+uint_t zfs_dbuf_evict_key;
-static void dbuf_destroy(dmu_buf_impl_t *db);
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);
-#ifndef __lint
extern inline void dmu_buf_init_user(dmu_buf_user_t *dbu,
- dmu_buf_evict_func_t *evict_func, dmu_buf_t **clear_on_evict_dbufp);
-#endif /* ! __lint */
+ 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
dbuf_cons(void *vdb, void *unused, int kmflag)
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) && \
uint64_t idx;
dmu_buf_impl_t *db;
- hv = DBUF_HASH(os, obj, level, blkid);
+ hv = dbuf_hash(os, obj, level, blkid);
idx = hv & h->hash_table_mask;
mutex_enter(DBUF_HASH_MUTEX(h, idx));
dmu_buf_impl_t *dbf;
blkid = db->db_blkid;
- hv = DBUF_HASH(os, obj, level, blkid);
+ hv = dbuf_hash(os, obj, level, blkid);
idx = hv & h->hash_table_mask;
mutex_enter(DBUF_HASH_MUTEX(h, idx));
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);
}
uint64_t hv, idx;
dmu_buf_impl_t *dbf, **dbp;
- hv = DBUF_HASH(db->db_objset, db->db.db_object,
+ 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 maintain 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
#endif
/*
- * Invoke the callback from a taskq to avoid lock order reversals
- * and limit stack depth.
+ * 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.
*/
- taskq_dispatch_ent(dbu_evict_taskq, dbu->dbu_evict_func, dbu, 0,
- &dbu->dbu_tqent);
+ boolean_t has_async = (dbu->dbu_evict_func_async != NULL);
+
+ if (dbu->dbu_evict_func_sync != NULL)
+ dbu->dbu_evict_func_sync(dbu);
+
+ if (has_async) {
+ taskq_dispatch_ent(dbu_evict_taskq, dbu->dbu_evict_func_async,
+ dbu, 0, &dbu->dbu_tqent);
+ }
}
boolean_t
}
}
-void
-dbuf_evict(dmu_buf_impl_t *db)
+
+/*
+ * 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)
{
- ASSERT(MUTEX_HELD(&db->db_mtx));
- ASSERT(db->db_buf == NULL);
- ASSERT(db->db_data_pending == NULL);
+ dmu_buf_impl_t *db = obj;
- dbuf_clear(db);
- dbuf_destroy(db);
+ /*
+ * 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 boolean_t
+dbuf_cache_above_hiwater(void)
+{
+ uint64_t dbuf_cache_hiwater_bytes =
+ (dbuf_cache_max_bytes * dbuf_cache_hiwater_pct) / 100;
+
+ return (refcount_count(&dbuf_cache_size) >
+ dbuf_cache_max_bytes + dbuf_cache_hiwater_bytes);
+}
+
+static inline boolean_t
+dbuf_cache_above_lowater(void)
+{
+ uint64_t dbuf_cache_lowater_bytes =
+ (dbuf_cache_max_bytes * dbuf_cache_lowater_pct) / 100;
+
+ return (refcount_count(&dbuf_cache_size) >
+ dbuf_cache_max_bytes - 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;
+
+ /*
+ * 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_max_bytes) {
+ if (dbuf_cache_above_hiwater())
+ dbuf_evict_one();
+ cv_signal(&dbuf_evict_cv);
+ }
+}
+
+
+
void
dbuf_init(void)
{
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);
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_max_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
#else
kmem_free(h->hash_table, (h->hash_table_mask + 1) * sizeof (void *));
#endif
- kmem_cache_destroy(dbuf_cache);
+ 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);
}
/*
ASSERT3U(db->db.db_offset, ==, DMU_BONUS_BLKID);
} else if (db->db_blkid == DMU_SPILL_BLKID) {
ASSERT(dn != NULL);
- ASSERT3U(db->db.db_size, >=, dn->dn_bonuslen);
ASSERT0(db->db.db_offset);
} else {
ASSERT3U(db->db.db_offset, ==, db->db_blkid * db->db.db_size);
} else {
/* db is pointed to by an indirect block */
ASSERTV(int epb = db->db_parent->db.db_size >>
- SPA_BLKPTRSHIFT);
+ SPA_BLKPTRSHIFT);
ASSERT3U(db->db_parent->db_level, ==, db->db_level+1);
ASSERT3U(db->db_parent->db.db_object, ==,
db->db.db_object);
* 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) {
- ASSERTV(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);
+ }
}
}
}
{
ASSERT(MUTEX_HELD(&db->db_mtx));
dbuf_evict_user(db);
- db->db_buf = NULL;
+ ASSERT3P(db->db_buf, ==, NULL);
db->db.db_data = NULL;
if (db->db_state != DB_NOFILL)
db->db_state = DB_UNCACHED;
db->db_buf = buf;
ASSERT(buf->b_data != NULL);
db->db.db_data = buf->b_data;
- if (!arc_released(buf))
- arc_set_callback(buf, dbuf_do_evict, 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, blksz);
+ abuf = arc_loan_buf(spa, B_FALSE, blksz);
bcopy(db->db.db_data, abuf->b_data, blksz);
} else {
abuf = db->db_buf;
arc_loan_inuse_buf(abuf, db);
+ db->db_buf = NULL;
dbuf_clear_data(db);
mutex_exit(&db->db_mtx);
}
return (abuf);
}
+/*
+ * Calculate which level n block references the data at the level 0 offset
+ * provided.
+ */
uint64_t
-dbuf_whichblock(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);
} else {
ASSERT(db->db_blkid != DMU_BONUS_BLKID);
ASSERT3P(db->db_buf, ==, NULL);
- VERIFY(arc_buf_remove_ref(buf, db));
+ arc_buf_destroy(buf, db);
db->db_state = DB_UNCACHED;
}
cv_broadcast(&db->db_changed);
}
static int
-dbuf_read_impl(dmu_buf_impl_t *db, zio_t *zio, uint32_t *flags)
+dbuf_read_impl(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags)
{
dnode_t *dn;
zbookmark_phys_t zb;
ASSERT(db->db_buf == NULL);
if (db->db_blkid == DMU_BONUS_BLKID) {
+ /*
+ * The bonus length stored in the dnode may be less than
+ * the maximum available space in the bonus buffer.
+ */
int bonuslen = MIN(dn->dn_bonuslen, dn->dn_phys->dn_bonuslen);
+ int max_bonuslen = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots);
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);
+ 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);
BP_IS_HOLE(db->db_blkptr)))) {
arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db);
- DB_DNODE_EXIT(db);
- dbuf_set_data(db, arc_buf_alloc(db->db_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 (0);
}
if (DBUF_IS_L2CACHEABLE(db))
aflags |= ARC_FLAG_L2CACHE;
- if (DBUF_IS_L2COMPRESSIBLE(db))
- aflags |= ARC_FLAG_L2COMPRESS;
SET_BOOKMARK(&zb, db->db_objset->os_dsl_dataset ?
db->db_objset->os_dsl_dataset->ds_object : DMU_META_OBJSET,
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_FLAG_CACHED)
- *flags |= DB_RF_CACHED;
- return (SET_ERROR(err));
+ 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;
- boolean_t havepzio = (zio != NULL);
boolean_t prefetch;
dnode_t *dn;
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(&dn->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(&dn->dn_struct_rwlock);
DB_DNODE_EXIT(db);
} else if (db->db_state == DB_UNCACHED) {
spa_t *spa = dn->dn_objset->os_spa;
+ boolean_t need_wait = B_FALSE;
- if (zio == NULL)
+ if (zio == NULL &&
+ db->db_blkptr != NULL && !BP_IS_HOLE(db->db_blkptr)) {
zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);
-
- err = dbuf_read_impl(db, zio, &flags);
+ need_wait = B_TRUE;
+ }
+ err = dbuf_read_impl(db, zio, flags);
/* dbuf_read_impl has dropped db_mtx for us */
if (!err && prefetch)
- dmu_zfetch(&dn->dn_zfetch, db->db.db_offset,
- db->db.db_size, flags & DB_RF_CACHED);
+ dmu_zfetch(&dn->dn_zfetch, db->db_blkid, 1, B_TRUE);
if ((flags & DB_RF_HAVESTRUCT) == 0)
rw_exit(&dn->dn_struct_rwlock);
DB_DNODE_EXIT(db);
- if (!err && !havepzio)
+ if (!err && need_wait)
err = zio_wait(zio);
} else {
/*
*/
mutex_exit(&db->db_mtx);
if (prefetch)
- dmu_zfetch(&dn->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(&dn->dn_struct_rwlock);
DB_DNODE_EXIT(db);
mutex_exit(&db->db_mtx);
}
- ASSERT(err || havepzio || db->db_state == DB_CACHED);
return (err);
}
ASSERT(db->db_buf == NULL);
ASSERT(db->db.db_data == NULL);
- dbuf_set_data(db, arc_buf_alloc(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_clear_data(db);
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 == 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) {
- /* 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);
- spa_t *spa = db->db_objset->os_spa;
-
- dr->dt.dl.dr_data = arc_buf_alloc(spa, size, db, type);
- bcopy(db->db.db_data, dr->dt.dl.dr_data->b_data, size);
- } else {
- dbuf_clear_data(db);
- }
-}
-
void
dbuf_unoverride(dbuf_dirty_record_t *dr)
{
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);
* 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.
- *
- * This is a no-op if the dataset is in the middle of an incremental
- * receive; see comment below for details.
*/
void
dbuf_free_range(dnode_t *dn, uint64_t start_blkid, uint64_t end_blkid,
dmu_buf_impl_t *db, *db_next;
uint64_t txg = tx->tx_txg;
avl_index_t where;
- boolean_t freespill =
- (start_blkid == DMU_SPILL_BLKID || end_blkid == DMU_SPILL_BLKID);
- if (end_blkid > dn->dn_maxblkid && !freespill)
+ 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->db_state = DB_SEARCH;
mutex_enter(&dn->dn_dbufs_mtx);
- if (start_blkid >= dn->dn_unlisted_l0_blkid && !freespill) {
- /* There can't be any dbufs in this range; no need to search. */
-#ifdef DEBUG
- db = avl_find(&dn->dn_dbufs, db_search, &where);
- ASSERT3P(db, ==, NULL);
- db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER);
- ASSERT(db == NULL || db->db_level > 0);
-#endif
- goto out;
- } else if (dmu_objset_is_receiving(dn->dn_objset)) {
- /*
- * If we are receiving, we expect there to be no dbufs in
- * the range to be freed, because receive modifies each
- * block at most once, and in offset order. If this is
- * not the case, it can lead to performance problems,
- * so note that we unexpectedly took the slow path.
- */
- atomic_inc_64(&zfs_free_range_recv_miss);
- }
-
db = avl_find(&dn->dn_dbufs, db_search, &where);
ASSERT3P(db, ==, NULL);
+
db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER);
for (; db != NULL; db = db_next) {
}
if (refcount_count(&db->db_holds) == 0) {
ASSERT(db->db_buf);
- dbuf_clear(db);
+ dbuf_destroy(db);
continue;
}
/* The dbuf is referenced */
mutex_exit(&db->db_mtx);
}
-out:
kmem_free(db_search, sizeof (dmu_buf_impl_t));
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.
- *
- * This logic ensures that only block births for
- * filled blocks are considered.
- */
- ASSERT(MUTEX_HELD(&db->db_mtx));
- if (db->db_last_dirty && (db->db_blkptr == NULL ||
- !BP_IS_HOLE(db->db_blkptr))) {
- birth_txg = db->db_last_dirty->dr_txg;
- } else if (db->db_blkptr != NULL && !BP_IS_HOLE(db->db_blkptr)) {
- birth_txg = db->db_blkptr->blk_birth;
- }
-
- /*
- * If this block don't exist or is in a snapshot, it can't be freed.
- * Don't pass the bp to dsl_dataset_block_freeable() since we
- * are holding the db_mtx lock and might deadlock if we are
- * prefetching a dedup-ed block.
- */
- if (birth_txg != 0)
- return (ds == NULL ||
- dsl_dataset_block_freeable(ds, NULL, birth_txg));
- else
- return (B_FALSE);
-}
-
void
dbuf_new_size(dmu_buf_impl_t *db, int size, dmu_tx_t *tx)
{
dmu_buf_will_dirty(&db->db, tx);
/* create the data buffer for the new block */
- buf = arc_buf_alloc(dn->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));
+ arc_buf_destroy(obuf, db);
db->db.db_size = size;
if (db->db_level == 0) {
}
mutex_exit(&db->db_mtx);
- dnode_willuse_space(dn, size-osize, tx);
+ dmu_objset_willuse_space(dn->dn_objset, size - osize, tx);
DB_DNODE_EXIT(db);
}
(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)
{
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);
* objects may be dirtied in syncing context, but only if they
* were already pre-dirtied in open context.
*/
+#ifdef DEBUG
+ if (dn->dn_objset->os_dsl_dataset != NULL) {
+ rrw_enter(&dn->dn_objset->os_dsl_dataset->ds_bp_rwlock,
+ RW_READER, FTAG);
+ }
ASSERT(!dmu_tx_is_syncing(tx) ||
BP_IS_HOLE(dn->dn_objset->os_rootbp) ||
DMU_OBJECT_IS_SPECIAL(dn->dn_object) ||
dn->dn_objset->os_dsl_dataset == NULL);
+ if (dn->dn_objset->os_dsl_dataset != NULL)
+ rrw_exit(&dn->dn_objset->os_dsl_dataset->ds_bp_rwlock, FTAG);
+#endif
/*
* We make this assert for private objects as well, but after we
* check if we're already dirty. They are allowed to re-dirty
* 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 (dr && dr->dr_txg == tx->tx_txg) {
DB_DNODE_EXIT(db);
- 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)
- arc_buf_thaw(db->db_buf);
- }
+ dbuf_redirty(dr);
mutex_exit(&db->db_mtx);
return (dr);
}
(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
* this assertion only if we're not already dirty.
*/
os = dn->dn_objset;
+ VERIFY3U(tx->tx_txg, <=, spa_final_dirty_txg(os->os_spa));
+#ifdef DEBUG
+ if (dn->dn_objset->os_dsl_dataset != NULL)
+ rrw_enter(&os->os_dsl_dataset->ds_bp_rwlock, RW_READER, FTAG);
ASSERT(!dmu_tx_is_syncing(tx) || DMU_OBJECT_IS_SPECIAL(dn->dn_object) ||
os->os_dsl_dataset == NULL || BP_IS_HOLE(os->os_rootbp));
+ if (dn->dn_objset->os_dsl_dataset != NULL)
+ rrw_exit(&os->os_dsl_dataset->ds_bp_rwlock, FTAG);
+#endif
ASSERT(db->db.db_size != 0);
dprintf_dbuf(db, "size=%llx\n", (u_longlong_t)db->db.db_size);
if (db->db_blkid != DMU_BONUS_BLKID) {
- /*
- * 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_dsize() while
- * also holding the db_mtx.
- */
- dnode_willuse_space(dn, db->db.db_size, tx);
- do_free_accounting = dbuf_block_freeable(db);
+ dmu_objset_willuse_space(os, db->db.db_size, tx);
}
/*
}
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));
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_dsize(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.
- */
- ddt_prefetch(os->os_spa, bp);
- 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);
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));
+ arc_buf_destroy(dr->dt.dl.dr_data, db);
}
kmem_free(dr, sizeof (dbuf_dirty_record_t));
db->db_dirtycnt -= 1;
if (refcount_remove(&db->db_holds, (void *)(uintptr_t)txg) == 0) {
- arc_buf_t *buf = db->db_buf;
-
- ASSERT(db->db_state == DB_NOFILL || arc_released(buf));
- dbuf_clear_data(db);
- VERIFY(arc_buf_remove_ref(buf, db));
- dbuf_evict(db);
+ ASSERT(db->db_state == DB_NOFILL || arc_released(db->db_buf));
+ dbuf_destroy(db);
return (B_TRUE);
}
{
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));
+ /*
+ * 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;
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);
ASSERT(!refcount_is_zero(&db->db_holds));
ASSERT(db->db_blkid != DMU_BONUS_BLKID);
ASSERT(db->db_level == 0);
- ASSERT(DBUF_GET_BUFC_TYPE(db) == ARC_BUFC_DATA);
+ ASSERT3U(dbuf_is_metadata(db), ==, arc_is_metadata(buf));
ASSERT(buf != NULL);
- ASSERT(arc_buf_size(buf) == db->db.db_size);
+ ASSERT(arc_buf_lsize(buf) == db->db.db_size);
ASSERT(tx->tx_txg != 0);
arc_return_buf(buf, db);
mutex_exit(&db->db_mtx);
(void) dbuf_dirty(db, tx);
bcopy(buf->b_data, db->db.db_data, db->db.db_size);
- VERIFY(arc_buf_remove_ref(buf, db));
+ arc_buf_destroy(buf, db);
xuio_stat_wbuf_copied();
return;
}
arc_release(db->db_buf, db);
}
dr->dt.dl.dr_data = buf;
- VERIFY(arc_buf_remove_ref(db->db_buf, db));
+ 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);
- VERIFY(arc_buf_remove_ref(db->db_buf, db));
+ arc_buf_destroy(db->db_buf, db);
}
db->db_buf = NULL;
}
dmu_buf_fill_done(&db->db, tx);
}
-/*
- * "Clear" the contents of this dbuf. This will mark the dbuf
- * EVICTING and clear *most* of its references. Unfortunately,
- * 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_clear_callback()->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_clear_callback()
- * ARC: dbuf_do_evict()->dbuf_destroy()
- *
- * This routine will dissociate the dbuf from the arc, by calling
- * arc_clear_callback(), but will not evict the data from the ARC.
- */
void
-dbuf_clear(dmu_buf_impl_t *db)
+dbuf_destroy(dmu_buf_impl_t *db)
{
dnode_t *dn;
dmu_buf_impl_t *parent = db->db_parent;
dmu_buf_impl_t *dndb;
- boolean_t dbuf_gone = B_FALSE;
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 == DMU_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;
+ /*
+ * 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 && MUTEX_HELD(&dn->dn_dbufs_mtx)) {
+ 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(),
*/
dnode_rele(dn, db);
db->db_dnode_handle = NULL;
+
+ dbuf_hash_remove(db);
} else {
DB_DNODE_EXIT(db);
}
- if (db->db_buf)
- dbuf_gone = arc_clear_callback(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 referenced from an indirect dbuf,
dbuf_rele(parent, db);
}
+/*
+ * 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,
mutex_enter(&dn->dn_mtx);
if (dn->dn_have_spill &&
(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR))
- *bpp = &dn->dn_phys->dn_spill;
+ *bpp = DN_SPILL_BLKPTR(dn->dn_phys);
else
*bpp = NULL;
dbuf_add_ref(dn->dn_dbuf, NULL);
return (0);
}
- if (dn->dn_phys->dn_nlevels == 0)
- nlevels = 1;
- else
- nlevels = dn->dn_phys->dn_nlevels;
-
+ 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 (SET_ERROR(ENOENT));
} else if (level < nlevels-1) {
/* this block is referenced from an indirect block */
int err;
if (dh == NULL) {
- err = dbuf_hold_impl(dn, level+1, blkid >> epbs,
- fail_sparse, NULL, parentp);
+ 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, NULL,
- parentp, dh->dh_depth + 1);
+ blkid >> epbs, fail_sparse, FALSE, NULL,
+ parentp, dh->dh_depth + 1);
err = __dbuf_hold_impl(dh + 1);
}
if (err)
}
*bpp = ((blkptr_t *)(*parentp)->db.db_data) +
(blkid & ((1ULL << epbs) - 1));
+ if (blkid > (dn->dn_phys->dn_maxblkid >> (level * epbs)))
+ ASSERT(BP_IS_HOLE(*bpp));
return (0);
} else {
/* the block is referenced from the dnode */
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;
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 = 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) ?
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);
}
avl_add(&dn->dn_dbufs, db);
- if (db->db_level == 0 && db->db_blkid >=
- dn->dn_unlisted_l0_blkid)
- dn->dn_unlisted_l0_blkid = db->db_blkid + 1;
+
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);
return (db);
}
-static int
-dbuf_do_evict(void *private)
-{
- dmu_buf_impl_t *db = 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));
+ dbuf_prefetch_arg_t *dpa = private;
+ uint64_t nextblkid;
+ blkptr_t *bp;
- if (db->db_blkid != DMU_BONUS_BLKID) {
- /*
- * If this dbuf is still on the dn_dbufs list,
- * remove it from that list.
- */
- if (db->db_dnode_handle != NULL) {
- dnode_t *dn;
+ ASSERT3S(dpa->dpa_zb.zb_level, <, dpa->dpa_curlevel);
+ ASSERT3S(dpa->dpa_curlevel, >, 0);
- DB_DNODE_ENTER(db);
- dn = DB_DNODE(db);
- mutex_enter(&dn->dn_dbufs_mtx);
- avl_remove(&dn->dn_dbufs, db);
- atomic_dec_32(&dn->dn_dbufs_count);
- mutex_exit(&dn->dn_dbufs_mtx);
- DB_DNODE_EXIT(db);
- /*
- * 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.
- */
- dnode_rele(dn, db);
- db->db_dnode_handle = 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(db->db.db_data == NULL);
- ASSERT(db->db_hash_next == NULL);
- ASSERT(db->db_blkptr == NULL);
- ASSERT(db->db_data_pending == NULL);
+ ASSERT3U(dpa->dpa_curlevel, ==, BP_GET_LEVEL(bp));
+
+ SET_BOOKMARK(&zb, dpa->dpa_zb.zb_objset,
+ dpa->dpa_zb.zb_object, dpa->dpa_curlevel, nextblkid);
+
+ (void) arc_read(dpa->dpa_zio, dpa->dpa_spa,
+ bp, dbuf_prefetch_indirect_done, dpa, dpa->dpa_prio,
+ ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
+ &iter_aflags, &zb);
+ }
- kmem_cache_free(dbuf_cache, db);
- arc_space_return(sizeof (dmu_buf_impl_t), ARC_SPACE_OTHER);
+ 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, zio_priority_t prio)
+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 != 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->dn_objset, dn->dn_object, 0, blkid))) {
+ /*
+ * 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);
/*
- * This dbuf is already in the cache. We assume that
- * it is already CACHED, or else about to be either
- * read or filled.
+ * This dbuf already exists. It is either CACHED, or
+ * (we assume) about to be read or filled.
*/
- mutex_exit(&db->db_mtx);
return;
}
- if (dbuf_findbp(dn, 0, blkid, TRUE, &db, &bp, NULL) == 0) {
- if (bp && !BP_IS_HOLE(bp) && !BP_IS_EMBEDDED(bp)) {
- dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset;
- arc_flags_t aflags =
- ARC_FLAG_NOWAIT | ARC_FLAG_PREFETCH;
- zbookmark_phys_t 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;
+ }
+
+ curlevel = parent_level;
+ curblkid = parent_blkid;
+ }
- SET_BOOKMARK(&zb, ds ? ds->ds_object : DMU_META_OBJSET,
- dn->dn_object, 0, 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;
- (void) arc_read(NULL, dn->dn_objset->os_spa,
- bp, NULL, NULL, prio,
- ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
- &aflags, &zb);
- }
- if (db)
- dbuf_rele(db, NULL);
+ 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;
+
+ /*
+ * 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;
+
+ 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
ASSERT3U(dh->dh_dn->dn_nlevels, >, dh->dh_level);
*(dh->dh_dbp) = NULL;
-top:
+
/* 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);
+ 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))
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);
+ dh->dh_parent, dh->dh_bp);
}
- if (dh->dh_db->db_buf && refcount_is_zero(&dh->dh_db->db_holds)) {
- arc_buf_add_ref(dh->dh_db->db_buf, dh->dh_db);
- if (dh->dh_db->db_buf->b_data == NULL) {
- dbuf_clear(dh->dh_db);
- if (dh->dh_parent) {
- dbuf_rele(dh->dh_parent, NULL);
- dh->dh_parent = NULL;
- }
- goto top;
- }
- ASSERT3P(dh->dh_db->db.db_data, ==, dh->dh_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));
}
+ if (dh->dh_db->db_buf != NULL)
+ 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));
/*
dh->dh_type = DBUF_GET_BUFC_TYPE(dh->dh_db);
dbuf_set_data(dh->dh_db,
- arc_buf_alloc(dh->dh_dn->dn_objset->os_spa,
- dh->dh_db->db.db_size, dh->dh_db, dh->dh_type));
+ arc_alloc_buf(dh->dh_dn->dn_objset->os_spa,
+ dh->dh_db, dh->dh_type, dh->dh_db->db.db_size));
bcopy(dh->dh_dr->dt.dl.dr_data->b_data,
dh->dh_db->db.db_data, dh->dh_db->db.db_size);
}
}
+ 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);
* on the stack for 20 levels of recursion.
*/
int
-dbuf_hold_impl(dnode_t *dn, uint8_t level, uint64_t blkid, int fail_sparse,
+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_zalloc(sizeof (struct dbuf_hold_impl_data) *
+ 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, tag, dbp, 0);
+ __dbuf_hold_impl_init(dh, dn, level, blkid, fail_sparse,
+ fail_uncached, tag, dbp, 0);
error = __dbuf_hold_impl(dh);
static void
__dbuf_hold_impl_init(struct dbuf_hold_impl_data *dh,
- dnode_t *dn, uint8_t level, uint64_t blkid, int fail_sparse,
+ 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_type = 0;
+
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);
}
void
dbuf_add_ref(dmu_buf_impl_t *db, void *tag)
{
- VERIFY(refcount_add(&db->db_holds, tag) > 1);
+ int64_t holds = refcount_add(&db->db_holds, tag);
+ VERIFY3S(holds, >, 1);
}
#pragma weak dmu_buf_try_add_ref = dbuf_try_add_ref
* 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_user_immediate_evict)
*/
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_clear_data(db);
- VERIFY(arc_buf_remove_ref(buf, db));
- dbuf_evict(db);
+ dbuf_destroy(db);
} else {
- VERIFY(!arc_buf_remove_ref(db->db_buf, db));
+ 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;
+ }
- /*
- * A dbuf will be eligible for eviction if either the
- * 'primarycache' property is set or a duplicate
- * copy of this buffer is already cached in the arc.
- *
- * In the case of the 'primarycache' a buffer
- * is considered for eviction if it matches the
- * criteria set in the property.
- *
- * To decide if our buffer is considered a
- * duplicate, we must call into the arc to determine
- * if multiple buffers are referencing the same
- * block on-disk. If so, then we simply evict
- * ourselves.
- */
- if (!DBUF_IS_CACHEABLE(db)) {
- if (db->db_blkptr != NULL &&
- !BP_IS_HOLE(db->db_blkptr) &&
- !BP_IS_EMBEDDED(db->db_blkptr)) {
- spa_t *spa =
- dmu_objset_spa(db->db_objset);
- blkptr_t bp = *db->db_blkptr;
- dbuf_clear(db);
- arc_freed(spa, &bp);
- } else {
- dbuf_clear(db);
- }
- } else if (db->db_pending_evict ||
- arc_buf_eviction_needed(db->db_buf)) {
- dbuf_clear(db);
- } else {
+ 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
taskq_wait(dbu_evict_taskq);
}
-boolean_t
-dmu_buf_freeable(dmu_buf_t *dbuf)
+blkptr_t *
+dmu_buf_get_blkptr(dmu_buf_t *db)
{
- boolean_t res = B_FALSE;
- dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbuf;
+ dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
+ return (dbi->db_blkptr);
+}
- if (db->db_blkptr)
- res = dsl_dataset_block_freeable(db->db_objset->os_dsl_dataset,
- db->db_blkptr, db->db_blkptr->blk_birth);
+objset_t *
+dmu_buf_get_objset(dmu_buf_t *db)
+{
+ dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
+ return (dbi->db_objset);
+}
- return (res);
+dnode_t *
+dmu_buf_dnode_enter(dmu_buf_t *db)
+{
+ dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
+ DB_DNODE_ENTER(dbi);
+ return (DB_DNODE(dbi));
}
-blkptr_t *
-dmu_buf_get_blkptr(dmu_buf_t *db)
+void
+dmu_buf_dnode_exit(dmu_buf_t *db)
{
dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db;
- return (dbi->db_blkptr);
+ DB_DNODE_EXIT(dbi);
}
static void
return;
if (db->db_blkid == DMU_SPILL_BLKID) {
- db->db_blkptr = &dn->dn_phys->dn_spill;
+ db->db_blkptr = DN_SPILL_BLKPTR(dn->dn_phys);
BP_ZERO(db->db_blkptr);
return;
}
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;
ASSERT(*datap != NULL);
ASSERT0(db->db_level);
- ASSERT3U(dn->dn_phys->dn_bonuslen, <=, DN_MAX_BONUSLEN);
+ 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;
* objects only modified in the syncing context (e.g.
* DNONE_DNODE blocks).
*/
- int blksz = arc_buf_size(*datap);
+ int psize = arc_buf_size(*datap);
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);
+ enum zio_compress compress_type = arc_get_compression(*datap);
+
+ 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);
+ }
+ bcopy(db->db.db_data, (*datap)->b_data, psize);
}
db->db_data_pending = dr;
uint64_t fill = 0;
int i;
- ASSERT3P(db->db_blkptr, ==, bp);
+ ASSERT3P(db->db_blkptr, !=, NULL);
+ ASSERT3P(&db->db_data_pending->dr_bp_copy, ==, bp);
DB_DNODE_ENTER(db);
dn = DB_DNODE(db);
#ifdef ZFS_DEBUG
if (db->db_blkid == DMU_SPILL_BLKID) {
ASSERT(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR);
- ASSERT(!(BP_IS_HOLE(db->db_blkptr)) &&
- db->db_blkptr == &dn->dn_phys->dn_spill);
+ ASSERT(!(BP_IS_HOLE(bp)) &&
+ db->db_blkptr == DN_SPILL_BLKPTR(dn->dn_phys));
}
#endif
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 {
if (BP_IS_HOLE(bp)) {
bp->blk_fill = fill;
mutex_exit(&db->db_mtx);
+
+ rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
+ *db->db_blkptr = *bp;
+ rw_exit(&dn->dn_struct_rwlock);
+}
+
+/* ARGSUSED */
+/*
+ * This function gets called just prior to running through the compression
+ * stage of the zio pipeline. If we're an indirect block comprised of only
+ * holes, then we want this indirect to be compressed away to a hole. In
+ * order to do that we must zero out any information about the holes that
+ * this indirect points to prior to before we try to compress it.
+ */
+static void
+dbuf_write_children_ready(zio_t *zio, arc_buf_t *buf, void *vdb)
+{
+ dmu_buf_impl_t *db = vdb;
+ dnode_t *dn;
+ blkptr_t *bp;
+ unsigned int epbs, i;
+
+ ASSERT3U(db->db_level, >, 0);
+ DB_DNODE_ENTER(db);
+ dn = DB_DNODE(db);
+ epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT;
+ ASSERT3U(epbs, <, 31);
+
+ /* Determine if all our children are holes */
+ for (i = 0, bp = db->db.db_data; i < 1ULL << epbs; i++, bp++) {
+ if (!BP_IS_HOLE(bp))
+ break;
+ }
+
+ /*
+ * If all the children are holes, then zero them all out so that
+ * we may get compressed away.
+ */
+ if (i == 1ULL << epbs) {
+ /*
+ * We only found holes. Grab the rwlock to prevent
+ * anybody from reading the blocks we're about to
+ * zero out.
+ */
+ rw_enter(&dn->dn_struct_rwlock, RW_WRITER);
+ bzero(db->db.db_data, db->db.db_size);
+ rw_exit(&dn->dn_struct_rwlock);
+ }
+ DB_DNODE_EXIT(db);
}
/*
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->dn_phys->dn_spill);
+ db->db_blkptr == DN_SPILL_BLKPTR(dn->dn_phys));
DB_DNODE_EXIT(db);
}
#endif
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));
- else if (!arc_released(db->db_buf))
- arc_set_callback(db->db_buf, dbuf_do_evict, db);
+ arc_buf_destroy(dr->dt.dl.dr_data, db);
}
} else {
dnode_t *dn;
dn->dn_phys->dn_maxblkid >> (db->db_level * epbs));
ASSERT3U(BP_GET_LSIZE(db->db_blkptr), ==,
db->db.db_size);
- if (!arc_released(db->db_buf))
- arc_set_callback(db->db_buf, dbuf_do_evict, db);
}
DB_DNODE_EXIT(db);
mutex_destroy(&dr->dt.di.dr_mtx);
mutex_exit(&db->db_mtx);
dbuf_write_done(zio, NULL, db);
+
+ if (zio->io_abd != NULL)
+ abd_put(zio->io_abd);
}
/* Issue I/O to commit a dirty buffer to disk. */
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;
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()).
*/
- void *contents = (data != NULL) ? data->b_data : NULL;
+ 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,
- db->db_blkptr, contents, db->db.db_size, &zp,
- dbuf_write_override_ready, NULL, dbuf_write_override_done,
+ &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;
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);
+ ASSERT(zp.zp_checksum == ZIO_CHECKSUM_OFF ||
+ zp.zp_checksum == ZIO_CHECKSUM_NOPARITY);
dr->dr_zio = zio_write(zio, os->os_spa, txg,
- db->db_blkptr, NULL, db->db.db_size, &zp,
- dbuf_write_nofill_ready, NULL, dbuf_write_nofill_done, db,
+ &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,
- db->db_blkptr, data, DBUF_IS_L2CACHEABLE(db),
- DBUF_IS_L2COMPRESSIBLE(db), &zp, dbuf_write_ready,
- dbuf_write_physdone, dbuf_write_done, db,
- ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_MUSTSUCCEED, &zb);
+ &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_evict);
+EXPORT_SYMBOL(dbuf_destroy);
EXPORT_SYMBOL(dbuf_loan_arcbuf);
EXPORT_SYMBOL(dbuf_whichblock);
EXPORT_SYMBOL(dbuf_read);
EXPORT_SYMBOL(dmu_buf_fill_done);
EXPORT_SYMBOL(dmu_buf_rele);
EXPORT_SYMBOL(dbuf_assign_arcbuf);
-EXPORT_SYMBOL(dbuf_clear);
EXPORT_SYMBOL(dbuf_prefetch);
EXPORT_SYMBOL(dbuf_hold_impl);
EXPORT_SYMBOL(dbuf_hold);
EXPORT_SYMBOL(dmu_buf_set_user);
EXPORT_SYMBOL(dmu_buf_set_user_ie);
EXPORT_SYMBOL(dmu_buf_get_user);
-EXPORT_SYMBOL(dmu_buf_freeable);
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
projects / mirror_zfs-debian.git / blobdiff