* CDDL HEADER END
*/
/*
- * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
- * Use is subject to license terms.
+ * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Portions Copyright 2011 Martin Matuska
+ * Copyright (c) 2012, 2019 by Delphix. All rights reserved.
*/
#include <sys/zfs_context.h>
#include <sys/txg_impl.h>
#include <sys/dmu_impl.h>
+#include <sys/spa_impl.h>
+#include <sys/dmu_tx.h>
#include <sys/dsl_pool.h>
+#include <sys/dsl_scan.h>
+#include <sys/zil.h>
#include <sys/callb.h>
+#include <sys/trace_zfs.h>
/*
- * Pool-wide transaction groups.
+ * ZFS Transaction Groups
+ * ----------------------
+ *
+ * ZFS transaction groups are, as the name implies, groups of transactions
+ * that act on persistent state. ZFS asserts consistency at the granularity of
+ * these transaction groups. Each successive transaction group (txg) is
+ * assigned a 64-bit consecutive identifier. There are three active
+ * transaction group states: open, quiescing, or syncing. At any given time,
+ * there may be an active txg associated with each state; each active txg may
+ * either be processing, or blocked waiting to enter the next state. There may
+ * be up to three active txgs, and there is always a txg in the open state
+ * (though it may be blocked waiting to enter the quiescing state). In broad
+ * strokes, transactions -- operations that change in-memory structures -- are
+ * accepted into the txg in the open state, and are completed while the txg is
+ * in the open or quiescing states. The accumulated changes are written to
+ * disk in the syncing state.
+ *
+ * Open
+ *
+ * When a new txg becomes active, it first enters the open state. New
+ * transactions -- updates to in-memory structures -- are assigned to the
+ * currently open txg. There is always a txg in the open state so that ZFS can
+ * accept new changes (though the txg may refuse new changes if it has hit
+ * some limit). ZFS advances the open txg to the next state for a variety of
+ * reasons such as it hitting a time or size threshold, or the execution of an
+ * administrative action that must be completed in the syncing state.
+ *
+ * Quiescing
+ *
+ * After a txg exits the open state, it enters the quiescing state. The
+ * quiescing state is intended to provide a buffer between accepting new
+ * transactions in the open state and writing them out to stable storage in
+ * the syncing state. While quiescing, transactions can continue their
+ * operation without delaying either of the other states. Typically, a txg is
+ * in the quiescing state very briefly since the operations are bounded by
+ * software latencies rather than, say, slower I/O latencies. After all
+ * transactions complete, the txg is ready to enter the next state.
+ *
+ * Syncing
+ *
+ * In the syncing state, the in-memory state built up during the open and (to
+ * a lesser degree) the quiescing states is written to stable storage. The
+ * process of writing out modified data can, in turn modify more data. For
+ * example when we write new blocks, we need to allocate space for them; those
+ * allocations modify metadata (space maps)... which themselves must be
+ * written to stable storage. During the sync state, ZFS iterates, writing out
+ * data until it converges and all in-memory changes have been written out.
+ * The first such pass is the largest as it encompasses all the modified user
+ * data (as opposed to filesystem metadata). Subsequent passes typically have
+ * far less data to write as they consist exclusively of filesystem metadata.
+ *
+ * To ensure convergence, after a certain number of passes ZFS begins
+ * overwriting locations on stable storage that had been allocated earlier in
+ * the syncing state (and subsequently freed). ZFS usually allocates new
+ * blocks to optimize for large, continuous, writes. For the syncing state to
+ * converge however it must complete a pass where no new blocks are allocated
+ * since each allocation requires a modification of persistent metadata.
+ * Further, to hasten convergence, after a prescribed number of passes, ZFS
+ * also defers frees, and stops compressing.
+ *
+ * In addition to writing out user data, we must also execute synctasks during
+ * the syncing context. A synctask is the mechanism by which some
+ * administrative activities work such as creating and destroying snapshots or
+ * datasets. Note that when a synctask is initiated it enters the open txg,
+ * and ZFS then pushes that txg as quickly as possible to completion of the
+ * syncing state in order to reduce the latency of the administrative
+ * activity. To complete the syncing state, ZFS writes out a new uberblock,
+ * the root of the tree of blocks that comprise all state stored on the ZFS
+ * pool. Finally, if there is a quiesced txg waiting, we signal that it can
+ * now transition to the syncing state.
*/
-static void txg_sync_thread(dsl_pool_t *dp);
-static void txg_quiesce_thread(dsl_pool_t *dp);
+static void txg_sync_thread(void *arg);
+static void txg_quiesce_thread(void *arg);
-int zfs_txg_timeout = 30; /* max seconds worth of delta per txg */
+int zfs_txg_timeout = 5; /* max seconds worth of delta per txg */
/*
* Prepare the txg subsystem.
int c;
bzero(tx, sizeof (tx_state_t));
- tx->tx_cpu = kmem_zalloc(max_ncpus * sizeof (tx_cpu_t), KM_SLEEP);
+ tx->tx_cpu = vmem_zalloc(max_ncpus * sizeof (tx_cpu_t), KM_SLEEP);
for (c = 0; c < max_ncpus; c++) {
int i;
mutex_init(&tx->tx_cpu[c].tc_lock, NULL, MUTEX_DEFAULT, NULL);
+ mutex_init(&tx->tx_cpu[c].tc_open_lock, NULL, MUTEX_NOLOCKDEP,
+ NULL);
for (i = 0; i < TXG_SIZE; i++) {
cv_init(&tx->tx_cpu[c].tc_cv[i], NULL, CV_DEFAULT,
NULL);
+ list_create(&tx->tx_cpu[c].tc_callbacks[i],
+ sizeof (dmu_tx_callback_t),
+ offsetof(dmu_tx_callback_t, dcb_node));
}
}
- rw_init(&tx->tx_suspend, NULL, RW_DEFAULT, NULL);
mutex_init(&tx->tx_sync_lock, NULL, MUTEX_DEFAULT, NULL);
cv_init(&tx->tx_sync_more_cv, NULL, CV_DEFAULT, NULL);
tx_state_t *tx = &dp->dp_tx;
int c;
- ASSERT(tx->tx_threads == 0);
+ ASSERT0(tx->tx_threads);
- rw_destroy(&tx->tx_suspend);
mutex_destroy(&tx->tx_sync_lock);
cv_destroy(&tx->tx_sync_more_cv);
for (c = 0; c < max_ncpus; c++) {
int i;
+ mutex_destroy(&tx->tx_cpu[c].tc_open_lock);
mutex_destroy(&tx->tx_cpu[c].tc_lock);
- for (i = 0; i < TXG_SIZE; i++)
+ for (i = 0; i < TXG_SIZE; i++) {
cv_destroy(&tx->tx_cpu[c].tc_cv[i]);
+ list_destroy(&tx->tx_cpu[c].tc_callbacks[i]);
+ }
}
- kmem_free(tx->tx_cpu, max_ncpus * sizeof (tx_cpu_t));
+ if (tx->tx_commit_cb_taskq != NULL)
+ taskq_destroy(tx->tx_commit_cb_taskq);
+
+ vmem_free(tx->tx_cpu, max_ncpus * sizeof (tx_cpu_t));
bzero(tx, sizeof (tx_state_t));
}
dprintf("pool %p\n", dp);
- ASSERT(tx->tx_threads == 0);
+ ASSERT0(tx->tx_threads);
tx->tx_threads = 2;
tx->tx_quiesce_thread = thread_create(NULL, 0, txg_quiesce_thread,
- dp, 0, &p0, TS_RUN, minclsyspri);
+ dp, 0, &p0, TS_RUN, defclsyspri);
/*
* The sync thread can need a larger-than-default stack size on
* 32-bit x86. This is due in part to nested pools and
* scrub_visitbp() recursion.
*/
- tx->tx_sync_thread = thread_create(NULL, 12<<10, txg_sync_thread,
- dp, 0, &p0, TS_RUN, minclsyspri);
+ tx->tx_sync_thread = thread_create(NULL, 0, txg_sync_thread,
+ dp, 0, &p0, TS_RUN, defclsyspri);
mutex_exit(&tx->tx_sync_lock);
}
}
static void
-txg_thread_wait(tx_state_t *tx, callb_cpr_t *cpr, kcondvar_t *cv, uint64_t time)
+txg_thread_wait(tx_state_t *tx, callb_cpr_t *cpr, kcondvar_t *cv, clock_t time)
{
CALLB_CPR_SAFE_BEGIN(cpr);
- if (time)
- (void) cv_timedwait(cv, &tx->tx_sync_lock, lbolt + time);
- else
- cv_wait(cv, &tx->tx_sync_lock);
+ if (time) {
+ (void) cv_timedwait_idle(cv, &tx->tx_sync_lock,
+ ddi_get_lbolt() + time);
+ } else {
+ cv_wait_idle(cv, &tx->tx_sync_lock);
+ }
CALLB_CPR_SAFE_END(cpr, &tx->tx_sync_lock);
}
/*
* Finish off any work in progress.
*/
- ASSERT(tx->tx_threads == 2);
- txg_wait_synced(dp, 0);
+ ASSERT3U(tx->tx_threads, ==, 2);
+
+ /*
+ * We need to ensure that we've vacated the deferred metaslab trees.
+ */
+ txg_wait_synced(dp, tx->tx_open_txg + TXG_DEFER_SIZE);
/*
* Wake all sync threads and wait for them to die.
*/
mutex_enter(&tx->tx_sync_lock);
- ASSERT(tx->tx_threads == 2);
+ ASSERT3U(tx->tx_threads, ==, 2);
tx->tx_exiting = 1;
txg_hold_open(dsl_pool_t *dp, txg_handle_t *th)
{
tx_state_t *tx = &dp->dp_tx;
- tx_cpu_t *tc = &tx->tx_cpu[CPU_SEQID];
+ tx_cpu_t *tc;
uint64_t txg;
- mutex_enter(&tc->tc_lock);
+ /*
+ * It appears the processor id is simply used as a "random"
+ * number to index into the array, and there isn't any other
+ * significance to the chosen tx_cpu. Because.. Why not use
+ * the current cpu to index into the array?
+ */
+ tc = &tx->tx_cpu[CPU_SEQID_UNSTABLE];
+ mutex_enter(&tc->tc_open_lock);
txg = tx->tx_open_txg;
+
+ mutex_enter(&tc->tc_lock);
tc->tc_count[txg & TXG_MASK]++;
+ mutex_exit(&tc->tc_lock);
th->th_cpu = tc;
th->th_txg = txg;
{
tx_cpu_t *tc = th->th_cpu;
+ ASSERT(!MUTEX_HELD(&tc->tc_lock));
+ mutex_exit(&tc->tc_open_lock);
+}
+
+void
+txg_register_callbacks(txg_handle_t *th, list_t *tx_callbacks)
+{
+ tx_cpu_t *tc = th->th_cpu;
+ int g = th->th_txg & TXG_MASK;
+
+ mutex_enter(&tc->tc_lock);
+ list_move_tail(&tc->tc_callbacks[g], tx_callbacks);
mutex_exit(&tc->tc_lock);
}
th->th_cpu = NULL; /* defensive */
}
+/*
+ * Blocks until all transactions in the group are committed.
+ *
+ * On return, the transaction group has reached a stable state in which it can
+ * then be passed off to the syncing context.
+ */
static void
txg_quiesce(dsl_pool_t *dp, uint64_t txg)
{
tx_state_t *tx = &dp->dp_tx;
+ uint64_t tx_open_time;
int g = txg & TXG_MASK;
int c;
/*
- * Grab all tx_cpu locks so nobody else can get into this txg.
+ * Grab all tc_open_locks so nobody else can get into this txg.
*/
for (c = 0; c < max_ncpus; c++)
- mutex_enter(&tx->tx_cpu[c].tc_lock);
+ mutex_enter(&tx->tx_cpu[c].tc_open_lock);
ASSERT(txg == tx->tx_open_txg);
tx->tx_open_txg++;
+ tx->tx_open_time = tx_open_time = gethrtime();
+
+ DTRACE_PROBE2(txg__quiescing, dsl_pool_t *, dp, uint64_t, txg);
+ DTRACE_PROBE2(txg__opened, dsl_pool_t *, dp, uint64_t, tx->tx_open_txg);
/*
* Now that we've incremented tx_open_txg, we can let threads
* enter the next transaction group.
*/
for (c = 0; c < max_ncpus; c++)
- mutex_exit(&tx->tx_cpu[c].tc_lock);
+ mutex_exit(&tx->tx_cpu[c].tc_open_lock);
+
+ spa_txg_history_set(dp->dp_spa, txg, TXG_STATE_OPEN, tx_open_time);
+ spa_txg_history_add(dp->dp_spa, txg + 1, tx_open_time);
/*
* Quiesce the transaction group by waiting for everyone to txg_exit().
cv_wait(&tc->tc_cv[g], &tc->tc_lock);
mutex_exit(&tc->tc_lock);
}
+
+ spa_txg_history_set(dp->dp_spa, txg, TXG_STATE_QUIESCED, gethrtime());
+}
+
+static void
+txg_do_callbacks(list_t *cb_list)
+{
+ dmu_tx_do_callbacks(cb_list, 0);
+
+ list_destroy(cb_list);
+
+ kmem_free(cb_list, sizeof (list_t));
+}
+
+/*
+ * Dispatch the commit callbacks registered on this txg to worker threads.
+ *
+ * If no callbacks are registered for a given TXG, nothing happens.
+ * This function creates a taskq for the associated pool, if needed.
+ */
+static void
+txg_dispatch_callbacks(dsl_pool_t *dp, uint64_t txg)
+{
+ int c;
+ tx_state_t *tx = &dp->dp_tx;
+ list_t *cb_list;
+
+ for (c = 0; c < max_ncpus; c++) {
+ tx_cpu_t *tc = &tx->tx_cpu[c];
+ /*
+ * No need to lock tx_cpu_t at this point, since this can
+ * only be called once a txg has been synced.
+ */
+
+ int g = txg & TXG_MASK;
+
+ if (list_is_empty(&tc->tc_callbacks[g]))
+ continue;
+
+ if (tx->tx_commit_cb_taskq == NULL) {
+ /*
+ * Commit callback taskq hasn't been created yet.
+ */
+ tx->tx_commit_cb_taskq = taskq_create("tx_commit_cb",
+ 100, defclsyspri, boot_ncpus, boot_ncpus * 2,
+ TASKQ_PREPOPULATE | TASKQ_DYNAMIC |
+ TASKQ_THREADS_CPU_PCT);
+ }
+
+ cb_list = kmem_alloc(sizeof (list_t), KM_SLEEP);
+ list_create(cb_list, sizeof (dmu_tx_callback_t),
+ offsetof(dmu_tx_callback_t, dcb_node));
+
+ list_move_tail(cb_list, &tc->tc_callbacks[g]);
+
+ (void) taskq_dispatch(tx->tx_commit_cb_taskq, (task_func_t *)
+ txg_do_callbacks, cb_list, TQ_SLEEP);
+ }
+}
+
+/*
+ * Wait for pending commit callbacks of already-synced transactions to finish
+ * processing.
+ * Calling this function from within a commit callback will deadlock.
+ */
+void
+txg_wait_callbacks(dsl_pool_t *dp)
+{
+ tx_state_t *tx = &dp->dp_tx;
+
+ if (tx->tx_commit_cb_taskq != NULL)
+ taskq_wait_outstanding(tx->tx_commit_cb_taskq, 0);
+}
+
+static boolean_t
+txg_is_syncing(dsl_pool_t *dp)
+{
+ tx_state_t *tx = &dp->dp_tx;
+ ASSERT(MUTEX_HELD(&tx->tx_sync_lock));
+ return (tx->tx_syncing_txg != 0);
+}
+
+static boolean_t
+txg_is_quiescing(dsl_pool_t *dp)
+{
+ tx_state_t *tx = &dp->dp_tx;
+ ASSERT(MUTEX_HELD(&tx->tx_sync_lock));
+ return (tx->tx_quiescing_txg != 0);
+}
+
+static boolean_t
+txg_has_quiesced_to_sync(dsl_pool_t *dp)
+{
+ tx_state_t *tx = &dp->dp_tx;
+ ASSERT(MUTEX_HELD(&tx->tx_sync_lock));
+ return (tx->tx_quiesced_txg != 0);
}
static void
-txg_sync_thread(dsl_pool_t *dp)
+txg_sync_thread(void *arg)
{
+ dsl_pool_t *dp = arg;
+ spa_t *spa = dp->dp_spa;
tx_state_t *tx = &dp->dp_tx;
callb_cpr_t cpr;
- uint64_t start, delta;
+ clock_t start, delta;
+ (void) spl_fstrans_mark();
txg_thread_enter(tx, &cpr);
start = delta = 0;
for (;;) {
- uint64_t timer, timeout = zfs_txg_timeout * hz;
+ clock_t timeout = zfs_txg_timeout * hz;
+ clock_t timer;
uint64_t txg;
+ uint64_t dirty_min_bytes =
+ zfs_dirty_data_max * zfs_dirty_data_sync_percent / 100;
/*
- * We sync when we're scrubbing, there's someone waiting
+ * We sync when we're scanning, there's someone waiting
* on us, or the quiesce thread has handed off a txg to
* us, or we have reached our timeout.
*/
timer = (delta >= timeout ? 0 : timeout - delta);
- while ((dp->dp_scrub_func == SCRUB_FUNC_NONE ||
- spa_shutting_down(dp->dp_spa)) &&
+ while (!dsl_scan_active(dp->dp_scan) &&
!tx->tx_exiting && timer > 0 &&
tx->tx_synced_txg >= tx->tx_sync_txg_waiting &&
- tx->tx_quiesced_txg == 0) {
+ !txg_has_quiesced_to_sync(dp) &&
+ dp->dp_dirty_total < dirty_min_bytes) {
dprintf("waiting; tx_synced=%llu waiting=%llu dp=%p\n",
tx->tx_synced_txg, tx->tx_sync_txg_waiting, dp);
txg_thread_wait(tx, &cpr, &tx->tx_sync_more_cv, timer);
- delta = lbolt - start;
+ delta = ddi_get_lbolt() - start;
timer = (delta > timeout ? 0 : timeout - delta);
}
* Wait until the quiesce thread hands off a txg to us,
* prompting it to do so if necessary.
*/
- while (!tx->tx_exiting && tx->tx_quiesced_txg == 0) {
+ while (!tx->tx_exiting && !txg_has_quiesced_to_sync(dp)) {
if (tx->tx_quiesce_txg_waiting < tx->tx_open_txg+1)
tx->tx_quiesce_txg_waiting = tx->tx_open_txg+1;
cv_broadcast(&tx->tx_quiesce_more_cv);
if (tx->tx_exiting)
txg_thread_exit(tx, &cpr, &tx->tx_sync_thread);
- rw_enter(&tx->tx_suspend, RW_WRITER);
-
/*
* Consume the quiesced txg which has been handed off to
* us. This may cause the quiescing thread to now be
* able to quiesce another txg, so we must signal it.
*/
+ ASSERT(tx->tx_quiesced_txg != 0);
txg = tx->tx_quiesced_txg;
tx->tx_quiesced_txg = 0;
tx->tx_syncing_txg = txg;
+ DTRACE_PROBE2(txg__syncing, dsl_pool_t *, dp, uint64_t, txg);
cv_broadcast(&tx->tx_quiesce_more_cv);
- rw_exit(&tx->tx_suspend);
dprintf("txg=%llu quiesce_txg=%llu sync_txg=%llu\n",
txg, tx->tx_quiesce_txg_waiting, tx->tx_sync_txg_waiting);
mutex_exit(&tx->tx_sync_lock);
- start = lbolt;
- spa_sync(dp->dp_spa, txg);
- delta = lbolt - start;
+ txg_stat_t *ts = spa_txg_history_init_io(spa, txg, dp);
+ start = ddi_get_lbolt();
+ spa_sync(spa, txg);
+ delta = ddi_get_lbolt() - start;
+ spa_txg_history_fini_io(spa, ts);
mutex_enter(&tx->tx_sync_lock);
- rw_enter(&tx->tx_suspend, RW_WRITER);
tx->tx_synced_txg = txg;
tx->tx_syncing_txg = 0;
- rw_exit(&tx->tx_suspend);
+ DTRACE_PROBE2(txg__synced, dsl_pool_t *, dp, uint64_t, txg);
cv_broadcast(&tx->tx_sync_done_cv);
+
+ /*
+ * Dispatch commit callbacks to worker threads.
+ */
+ txg_dispatch_callbacks(dp, txg);
}
}
static void
-txg_quiesce_thread(dsl_pool_t *dp)
+txg_quiesce_thread(void *arg)
{
+ dsl_pool_t *dp = arg;
tx_state_t *tx = &dp->dp_tx;
callb_cpr_t cpr;
*/
while (!tx->tx_exiting &&
(tx->tx_open_txg >= tx->tx_quiesce_txg_waiting ||
- tx->tx_quiesced_txg != 0))
+ txg_has_quiesced_to_sync(dp)))
txg_thread_wait(tx, &cpr, &tx->tx_quiesce_more_cv, 0);
if (tx->tx_exiting)
dprintf("txg=%llu quiesce_txg=%llu sync_txg=%llu\n",
txg, tx->tx_quiesce_txg_waiting,
tx->tx_sync_txg_waiting);
+ tx->tx_quiescing_txg = txg;
+
mutex_exit(&tx->tx_sync_lock);
txg_quiesce(dp, txg);
mutex_enter(&tx->tx_sync_lock);
* Hand this txg off to the sync thread.
*/
dprintf("quiesce done, handing off txg %llu\n", txg);
+ tx->tx_quiescing_txg = 0;
tx->tx_quiesced_txg = txg;
+ DTRACE_PROBE2(txg__quiesced, dsl_pool_t *, dp, uint64_t, txg);
cv_broadcast(&tx->tx_sync_more_cv);
cv_broadcast(&tx->tx_quiesce_done_cv);
}
}
/*
- * Delay this thread by 'ticks' if we are still in the open transaction
- * group and there is already a waiting txg quiesing or quiesced. Abort
- * the delay if this txg stalls or enters the quiesing state.
+ * Delay this thread by delay nanoseconds if we are still in the open
+ * transaction group and there is already a waiting txg quiescing or quiesced.
+ * Abort the delay if this txg stalls or enters the quiescing state.
*/
void
-txg_delay(dsl_pool_t *dp, uint64_t txg, int ticks)
+txg_delay(dsl_pool_t *dp, uint64_t txg, hrtime_t delay, hrtime_t resolution)
{
tx_state_t *tx = &dp->dp_tx;
- int timeout = lbolt + ticks;
+ hrtime_t start = gethrtime();
- /* don't delay if this txg could transition to quiesing immediately */
+ /* don't delay if this txg could transition to quiescing immediately */
if (tx->tx_open_txg > txg ||
tx->tx_syncing_txg == txg-1 || tx->tx_synced_txg == txg-1)
return;
return;
}
- while (lbolt < timeout &&
- tx->tx_syncing_txg < txg-1 && !txg_stalled(dp))
- (void) cv_timedwait(&tx->tx_quiesce_more_cv, &tx->tx_sync_lock,
- timeout);
+ while (gethrtime() - start < delay &&
+ tx->tx_syncing_txg < txg-1 && !txg_stalled(dp)) {
+ (void) cv_timedwait_hires(&tx->tx_quiesce_more_cv,
+ &tx->tx_sync_lock, delay, resolution, 0);
+ }
+
+ DMU_TX_STAT_BUMP(dmu_tx_delay);
mutex_exit(&tx->tx_sync_lock);
}
-void
-txg_wait_synced(dsl_pool_t *dp, uint64_t txg)
+static boolean_t
+txg_wait_synced_impl(dsl_pool_t *dp, uint64_t txg, boolean_t wait_sig)
{
tx_state_t *tx = &dp->dp_tx;
+ ASSERT(!dsl_pool_config_held(dp));
+
mutex_enter(&tx->tx_sync_lock);
- ASSERT(tx->tx_threads == 2);
+ ASSERT3U(tx->tx_threads, ==, 2);
if (txg == 0)
- txg = tx->tx_open_txg;
+ txg = tx->tx_open_txg + TXG_DEFER_SIZE;
if (tx->tx_sync_txg_waiting < txg)
tx->tx_sync_txg_waiting = txg;
dprintf("txg=%llu quiesce_txg=%llu sync_txg=%llu\n",
txg, tx->tx_quiesce_txg_waiting, tx->tx_sync_txg_waiting);
while (tx->tx_synced_txg < txg) {
dprintf("broadcasting sync more "
- "tx_synced=%llu waiting=%llu dp=%p\n",
+ "tx_synced=%llu waiting=%llu dp=%px\n",
tx->tx_synced_txg, tx->tx_sync_txg_waiting, dp);
cv_broadcast(&tx->tx_sync_more_cv);
- cv_wait(&tx->tx_sync_done_cv, &tx->tx_sync_lock);
+ if (wait_sig) {
+ /*
+ * Condition wait here but stop if the thread receives a
+ * signal. The caller may call txg_wait_synced*() again
+ * to resume waiting for this txg.
+ */
+ if (cv_wait_io_sig(&tx->tx_sync_done_cv,
+ &tx->tx_sync_lock) == 0) {
+ mutex_exit(&tx->tx_sync_lock);
+ return (B_TRUE);
+ }
+ } else {
+ cv_wait_io(&tx->tx_sync_done_cv, &tx->tx_sync_lock);
+ }
}
mutex_exit(&tx->tx_sync_lock);
+ return (B_FALSE);
+}
+
+void
+txg_wait_synced(dsl_pool_t *dp, uint64_t txg)
+{
+ VERIFY0(txg_wait_synced_impl(dp, txg, B_FALSE));
+}
+
+/*
+ * Similar to a txg_wait_synced but it can be interrupted from a signal.
+ * Returns B_TRUE if the thread was signaled while waiting.
+ */
+boolean_t
+txg_wait_synced_sig(dsl_pool_t *dp, uint64_t txg)
+{
+ return (txg_wait_synced_impl(dp, txg, B_TRUE));
}
+/*
+ * Wait for the specified open transaction group. Set should_quiesce
+ * when the current open txg should be quiesced immediately.
+ */
void
-txg_wait_open(dsl_pool_t *dp, uint64_t txg)
+txg_wait_open(dsl_pool_t *dp, uint64_t txg, boolean_t should_quiesce)
{
tx_state_t *tx = &dp->dp_tx;
+ ASSERT(!dsl_pool_config_held(dp));
+
mutex_enter(&tx->tx_sync_lock);
- ASSERT(tx->tx_threads == 2);
+ ASSERT3U(tx->tx_threads, ==, 2);
if (txg == 0)
txg = tx->tx_open_txg + 1;
- if (tx->tx_quiesce_txg_waiting < txg)
+ if (tx->tx_quiesce_txg_waiting < txg && should_quiesce)
tx->tx_quiesce_txg_waiting = txg;
dprintf("txg=%llu quiesce_txg=%llu sync_txg=%llu\n",
txg, tx->tx_quiesce_txg_waiting, tx->tx_sync_txg_waiting);
while (tx->tx_open_txg < txg) {
cv_broadcast(&tx->tx_quiesce_more_cv);
- cv_wait(&tx->tx_quiesce_done_cv, &tx->tx_sync_lock);
+ /*
+ * Callers setting should_quiesce will use cv_wait_io() and
+ * be accounted for as iowait time. Otherwise, the caller is
+ * understood to be idle and cv_wait_sig() is used to prevent
+ * incorrectly inflating the system load average.
+ */
+ if (should_quiesce == B_TRUE) {
+ cv_wait_io(&tx->tx_quiesce_done_cv, &tx->tx_sync_lock);
+ } else {
+ cv_wait_idle(&tx->tx_quiesce_done_cv,
+ &tx->tx_sync_lock);
+ }
+ }
+ mutex_exit(&tx->tx_sync_lock);
+}
+
+/*
+ * If there isn't a txg syncing or in the pipeline, push another txg through
+ * the pipeline by quiescing the open txg.
+ */
+void
+txg_kick(dsl_pool_t *dp)
+{
+ tx_state_t *tx = &dp->dp_tx;
+
+ ASSERT(!dsl_pool_config_held(dp));
+
+ mutex_enter(&tx->tx_sync_lock);
+ if (!txg_is_syncing(dp) &&
+ !txg_is_quiescing(dp) &&
+ tx->tx_quiesce_txg_waiting <= tx->tx_open_txg &&
+ tx->tx_sync_txg_waiting <= tx->tx_synced_txg &&
+ tx->tx_quiesced_txg <= tx->tx_synced_txg) {
+ tx->tx_quiesce_txg_waiting = tx->tx_open_txg + 1;
+ cv_broadcast(&tx->tx_quiesce_more_cv);
}
mutex_exit(&tx->tx_sync_lock);
}
tx->tx_quiesced_txg != 0);
}
+/*
+ * Verify that this txg is active (open, quiescing, syncing). Non-active
+ * txg's should not be manipulated.
+ */
+#ifdef ZFS_DEBUG
void
-txg_suspend(dsl_pool_t *dp)
-{
- tx_state_t *tx = &dp->dp_tx;
- /* XXX some code paths suspend when they are already suspended! */
- rw_enter(&tx->tx_suspend, RW_READER);
-}
-
-void
-txg_resume(dsl_pool_t *dp)
+txg_verify(spa_t *spa, uint64_t txg)
{
- tx_state_t *tx = &dp->dp_tx;
- rw_exit(&tx->tx_suspend);
+ dsl_pool_t *dp __maybe_unused = spa_get_dsl(spa);
+ if (txg <= TXG_INITIAL || txg == ZILTEST_TXG)
+ return;
+ ASSERT3U(txg, <=, dp->dp_tx.tx_open_txg);
+ ASSERT3U(txg, >=, dp->dp_tx.tx_synced_txg);
+ ASSERT3U(txg, >=, dp->dp_tx.tx_open_txg - TXG_CONCURRENT_STATES);
}
+#endif
/*
* Per-txg object lists.
*/
void
-txg_list_create(txg_list_t *tl, size_t offset)
+txg_list_create(txg_list_t *tl, spa_t *spa, size_t offset)
{
int t;
mutex_init(&tl->tl_lock, NULL, MUTEX_DEFAULT, NULL);
tl->tl_offset = offset;
+ tl->tl_spa = spa;
for (t = 0; t < TXG_SIZE; t++)
tl->tl_head[t] = NULL;
}
+static boolean_t
+txg_list_empty_impl(txg_list_t *tl, uint64_t txg)
+{
+ ASSERT(MUTEX_HELD(&tl->tl_lock));
+ TXG_VERIFY(tl->tl_spa, txg);
+ return (tl->tl_head[txg & TXG_MASK] == NULL);
+}
+
+boolean_t
+txg_list_empty(txg_list_t *tl, uint64_t txg)
+{
+ mutex_enter(&tl->tl_lock);
+ boolean_t ret = txg_list_empty_impl(tl, txg);
+ mutex_exit(&tl->tl_lock);
+
+ return (ret);
+}
+
void
txg_list_destroy(txg_list_t *tl)
{
int t;
+ mutex_enter(&tl->tl_lock);
for (t = 0; t < TXG_SIZE; t++)
- ASSERT(txg_list_empty(tl, t));
+ ASSERT(txg_list_empty_impl(tl, t));
+ mutex_exit(&tl->tl_lock);
mutex_destroy(&tl->tl_lock);
}
-int
-txg_list_empty(txg_list_t *tl, uint64_t txg)
+/*
+ * Returns true if all txg lists are empty.
+ *
+ * Warning: this is inherently racy (an item could be added immediately
+ * after this function returns).
+ */
+boolean_t
+txg_all_lists_empty(txg_list_t *tl)
{
- return (tl->tl_head[txg & TXG_MASK] == NULL);
+ mutex_enter(&tl->tl_lock);
+ for (int i = 0; i < TXG_SIZE; i++) {
+ if (!txg_list_empty_impl(tl, i)) {
+ mutex_exit(&tl->tl_lock);
+ return (B_FALSE);
+ }
+ }
+ mutex_exit(&tl->tl_lock);
+ return (B_TRUE);
}
/*
- * Add an entry to the list.
- * Returns 0 if it's a new entry, 1 if it's already there.
+ * Add an entry to the list (unless it's already on the list).
+ * Returns B_TRUE if it was actually added.
*/
-int
+boolean_t
txg_list_add(txg_list_t *tl, void *p, uint64_t txg)
{
int t = txg & TXG_MASK;
txg_node_t *tn = (txg_node_t *)((char *)p + tl->tl_offset);
- int already_on_list;
+ boolean_t add;
+ TXG_VERIFY(tl->tl_spa, txg);
mutex_enter(&tl->tl_lock);
- already_on_list = tn->tn_member[t];
- if (!already_on_list) {
+ add = (tn->tn_member[t] == 0);
+ if (add) {
tn->tn_member[t] = 1;
tn->tn_next[t] = tl->tl_head[t];
tl->tl_head[t] = tn;
}
mutex_exit(&tl->tl_lock);
- return (already_on_list);
+ return (add);
+}
+
+/*
+ * Add an entry to the end of the list, unless it's already on the list.
+ * (walks list to find end)
+ * Returns B_TRUE if it was actually added.
+ */
+boolean_t
+txg_list_add_tail(txg_list_t *tl, void *p, uint64_t txg)
+{
+ int t = txg & TXG_MASK;
+ txg_node_t *tn = (txg_node_t *)((char *)p + tl->tl_offset);
+ boolean_t add;
+
+ TXG_VERIFY(tl->tl_spa, txg);
+ mutex_enter(&tl->tl_lock);
+ add = (tn->tn_member[t] == 0);
+ if (add) {
+ txg_node_t **tp;
+
+ for (tp = &tl->tl_head[t]; *tp != NULL; tp = &(*tp)->tn_next[t])
+ continue;
+
+ tn->tn_member[t] = 1;
+ tn->tn_next[t] = NULL;
+ *tp = tn;
+ }
+ mutex_exit(&tl->tl_lock);
+
+ return (add);
}
/*
txg_node_t *tn;
void *p = NULL;
+ TXG_VERIFY(tl->tl_spa, txg);
mutex_enter(&tl->tl_lock);
if ((tn = tl->tl_head[t]) != NULL) {
+ ASSERT(tn->tn_member[t]);
+ ASSERT(tn->tn_next[t] == NULL || tn->tn_next[t]->tn_member[t]);
p = (char *)tn - tl->tl_offset;
tl->tl_head[t] = tn->tn_next[t];
tn->tn_next[t] = NULL;
int t = txg & TXG_MASK;
txg_node_t *tn, **tp;
+ TXG_VERIFY(tl->tl_spa, txg);
mutex_enter(&tl->tl_lock);
for (tp = &tl->tl_head[t]; (tn = *tp) != NULL; tp = &tn->tn_next[t]) {
return (NULL);
}
-int
+boolean_t
txg_list_member(txg_list_t *tl, void *p, uint64_t txg)
{
int t = txg & TXG_MASK;
txg_node_t *tn = (txg_node_t *)((char *)p + tl->tl_offset);
- return (tn->tn_member[t]);
+ TXG_VERIFY(tl->tl_spa, txg);
+ return (tn->tn_member[t] != 0);
}
/*
- * Walk a txg list -- only safe if you know it's not changing.
+ * Walk a txg list
*/
void *
txg_list_head(txg_list_t *tl, uint64_t txg)
{
int t = txg & TXG_MASK;
- txg_node_t *tn = tl->tl_head[t];
+ txg_node_t *tn;
+ mutex_enter(&tl->tl_lock);
+ tn = tl->tl_head[t];
+ mutex_exit(&tl->tl_lock);
+
+ TXG_VERIFY(tl->tl_spa, txg);
return (tn == NULL ? NULL : (char *)tn - tl->tl_offset);
}
int t = txg & TXG_MASK;
txg_node_t *tn = (txg_node_t *)((char *)p + tl->tl_offset);
+ TXG_VERIFY(tl->tl_spa, txg);
+
+ mutex_enter(&tl->tl_lock);
tn = tn->tn_next[t];
+ mutex_exit(&tl->tl_lock);
return (tn == NULL ? NULL : (char *)tn - tl->tl_offset);
}
+
+EXPORT_SYMBOL(txg_init);
+EXPORT_SYMBOL(txg_fini);
+EXPORT_SYMBOL(txg_sync_start);
+EXPORT_SYMBOL(txg_sync_stop);
+EXPORT_SYMBOL(txg_hold_open);
+EXPORT_SYMBOL(txg_rele_to_quiesce);
+EXPORT_SYMBOL(txg_rele_to_sync);
+EXPORT_SYMBOL(txg_register_callbacks);
+EXPORT_SYMBOL(txg_delay);
+EXPORT_SYMBOL(txg_wait_synced);
+EXPORT_SYMBOL(txg_wait_open);
+EXPORT_SYMBOL(txg_wait_callbacks);
+EXPORT_SYMBOL(txg_stalled);
+EXPORT_SYMBOL(txg_sync_waiting);
+
+/* BEGIN CSTYLED */
+ZFS_MODULE_PARAM(zfs_txg, zfs_txg_, timeout, INT, ZMOD_RW,
+ "Max seconds worth of delta per txg");
+/* END CSTYLED */
projects / mirror_zfs.git / blobdiff