29 #include <sys/dsl_prop.h>
30 #include <sys/dsl_dir.h>
31 #include <sys/dsl_synctask.h>
32 #include <sys/dsl_scan.h>
33 #include <sys/dnode.h>
34 #include <sys/dmu_tx.h>
35 #include <sys/dmu_objset.h>
36 #include <sys/arc.h>
37 #include <sys/zap.h>
38 #include <sys/zio.h>
39 #include <sys/zfs_context.h>
40 #include <sys/fs/zfs.h>
41 #include <sys/zfs_znode.h>
42 #include <sys/spa_impl.h>
43 #include <sys/dsl_deadlist.h>
44 #include <sys/bptree.h>
45 #include <sys/zfeature.h>
46 #include <sys/zil_impl.h>
47 #include <sys/dsl_userhold.h>
48
49 int zfs_no_write_throttle = 0;
50 int zfs_write_limit_shift = 3; /* 1/8th of physical memory */
51 int zfs_txg_synctime_ms = 1000; /* target millisecs to sync a txg */
52
53 uint64_t zfs_write_limit_min = 32 << 20; /* min write limit is 32MB */
54 uint64_t zfs_write_limit_max = 0; /* max data payload per txg */
55 uint64_t zfs_write_limit_inflated = 0;
56 uint64_t zfs_write_limit_override = 0;
57
58 kmutex_t zfs_write_limit_lock;
59
60 static pgcnt_t old_physmem = 0;
61
62 hrtime_t zfs_throttle_delay = MSEC2NSEC(10);
63 hrtime_t zfs_throttle_resolution = MSEC2NSEC(10);
64
65 int
66 dsl_pool_open_special_dir(dsl_pool_t *dp, const char *name, dsl_dir_t **ddp)
67 {
68 uint64_t obj;
69 int err;
70
71 err = zap_lookup(dp->dp_meta_objset,
72 dp->dp_root_dir->dd_phys->dd_child_dir_zapobj,
73 name, sizeof (obj), 1, &obj);
74 if (err)
75 return (err);
76
77 return (dsl_dir_hold_obj(dp, obj, name, dp, ddp));
78 }
79
80 static dsl_pool_t *
81 dsl_pool_open_impl(spa_t *spa, uint64_t txg)
82 {
83 dsl_pool_t *dp;
84 blkptr_t *bp = spa_get_rootblkptr(spa);
85
86 dp = kmem_zalloc(sizeof (dsl_pool_t), KM_SLEEP);
87 dp->dp_spa = spa;
88 dp->dp_meta_rootbp = *bp;
89 rrw_init(&dp->dp_config_rwlock, B_TRUE);
90 dp->dp_write_limit = zfs_write_limit_min;
91 txg_init(dp, txg);
92
93 txg_list_create(&dp->dp_dirty_datasets,
94 offsetof(dsl_dataset_t, ds_dirty_link));
95 txg_list_create(&dp->dp_dirty_zilogs,
96 offsetof(zilog_t, zl_dirty_link));
97 txg_list_create(&dp->dp_dirty_dirs,
98 offsetof(dsl_dir_t, dd_dirty_link));
99 txg_list_create(&dp->dp_sync_tasks,
100 offsetof(dsl_sync_task_t, dst_node));
101
102 mutex_init(&dp->dp_lock, NULL, MUTEX_DEFAULT, NULL);
103
104 dp->dp_vnrele_taskq = taskq_create("zfs_vn_rele_taskq", 1, minclsyspri,
105 1, 4, 0);
106
107 return (dp);
108 }
109
110 int
111 dsl_pool_init(spa_t *spa, uint64_t txg, dsl_pool_t **dpp)
112 {
113 int err;
114 dsl_pool_t *dp = dsl_pool_open_impl(spa, txg);
115
116 err = dmu_objset_open_impl(spa, NULL, &dp->dp_meta_rootbp,
117 &dp->dp_meta_objset);
118 if (err != 0)
119 dsl_pool_close(dp);
120 else
121 *dpp = dp;
122
197 }
198
199 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
200 DMU_POOL_TMP_USERREFS, sizeof (uint64_t), 1,
201 &dp->dp_tmp_userrefs_obj);
202 if (err == ENOENT)
203 err = 0;
204 if (err)
205 goto out;
206
207 err = dsl_scan_init(dp, dp->dp_tx.tx_open_txg);
208
209 out:
210 rrw_exit(&dp->dp_config_rwlock, FTAG);
211 return (err);
212 }
213
214 void
215 dsl_pool_close(dsl_pool_t *dp)
216 {
217 /* drop our references from dsl_pool_open() */
218
219 /*
220 * Since we held the origin_snap from "syncing" context (which
221 * includes pool-opening context), it actually only got a "ref"
222 * and not a hold, so just drop that here.
223 */
224 if (dp->dp_origin_snap)
225 dsl_dataset_rele(dp->dp_origin_snap, dp);
226 if (dp->dp_mos_dir)
227 dsl_dir_rele(dp->dp_mos_dir, dp);
228 if (dp->dp_free_dir)
229 dsl_dir_rele(dp->dp_free_dir, dp);
230 if (dp->dp_root_dir)
231 dsl_dir_rele(dp->dp_root_dir, dp);
232
233 bpobj_close(&dp->dp_free_bpobj);
234
235 /* undo the dmu_objset_open_impl(mos) from dsl_pool_open() */
236 if (dp->dp_meta_objset)
237 dmu_objset_evict(dp->dp_meta_objset);
238
239 txg_list_destroy(&dp->dp_dirty_datasets);
329 void
330 dsl_pool_mos_diduse_space(dsl_pool_t *dp,
331 int64_t used, int64_t comp, int64_t uncomp)
332 {
333 ASSERT3U(comp, ==, uncomp); /* it's all metadata */
334 mutex_enter(&dp->dp_lock);
335 dp->dp_mos_used_delta += used;
336 dp->dp_mos_compressed_delta += comp;
337 dp->dp_mos_uncompressed_delta += uncomp;
338 mutex_exit(&dp->dp_lock);
339 }
340
341 static int
342 deadlist_enqueue_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
343 {
344 dsl_deadlist_t *dl = arg;
345 dsl_deadlist_insert(dl, bp, tx);
346 return (0);
347 }
348
349 void
350 dsl_pool_sync(dsl_pool_t *dp, uint64_t txg)
351 {
352 zio_t *zio;
353 dmu_tx_t *tx;
354 dsl_dir_t *dd;
355 dsl_dataset_t *ds;
356 objset_t *mos = dp->dp_meta_objset;
357 hrtime_t start, write_time;
358 uint64_t data_written;
359 int err;
360 list_t synced_datasets;
361
362 list_create(&synced_datasets, sizeof (dsl_dataset_t),
363 offsetof(dsl_dataset_t, ds_synced_link));
364
365 /*
366 * We need to copy dp_space_towrite() before doing
367 * dsl_sync_task_sync(), because
368 * dsl_dataset_snapshot_reserve_space() will increase
369 * dp_space_towrite but not actually write anything.
370 */
371 data_written = dp->dp_space_towrite[txg & TXG_MASK];
372
373 tx = dmu_tx_create_assigned(dp, txg);
374
375 dp->dp_read_overhead = 0;
376 start = gethrtime();
377
378 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
379 while (ds = txg_list_remove(&dp->dp_dirty_datasets, txg)) {
380 /*
381 * We must not sync any non-MOS datasets twice, because
382 * we may have taken a snapshot of them. However, we
383 * may sync newly-created datasets on pass 2.
384 */
385 ASSERT(!list_link_active(&ds->ds_synced_link));
386 list_insert_tail(&synced_datasets, ds);
387 dsl_dataset_sync(ds, zio, tx);
388 }
389 DTRACE_PROBE(pool_sync__1setup);
390 err = zio_wait(zio);
391
392 write_time = gethrtime() - start;
393 ASSERT(err == 0);
394 DTRACE_PROBE(pool_sync__2rootzio);
395
396 /*
397 * After the data blocks have been written (ensured by the zio_wait()
398 * above), update the user/group space accounting.
399 */
400 for (ds = list_head(&synced_datasets); ds;
401 ds = list_next(&synced_datasets, ds))
402 dmu_objset_do_userquota_updates(ds->ds_objset, tx);
403
404 /*
405 * Sync the datasets again to push out the changes due to
406 * userspace updates. This must be done before we process the
407 * sync tasks, so that any snapshots will have the correct
408 * user accounting information (and we won't get confused
409 * about which blocks are part of the snapshot).
410 */
411 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
412 while (ds = txg_list_remove(&dp->dp_dirty_datasets, txg)) {
413 ASSERT(list_link_active(&ds->ds_synced_link));
414 dmu_buf_rele(ds->ds_dbuf, ds);
415 dsl_dataset_sync(ds, zio, tx);
416 }
417 err = zio_wait(zio);
418
419 /*
420 * Now that the datasets have been completely synced, we can
421 * clean up our in-memory structures accumulated while syncing:
422 *
423 * - move dead blocks from the pending deadlist to the on-disk deadlist
424 * - release hold from dsl_dataset_dirty()
425 */
426 while (ds = list_remove_head(&synced_datasets)) {
427 objset_t *os = ds->ds_objset;
428 bplist_iterate(&ds->ds_pending_deadlist,
429 deadlist_enqueue_cb, &ds->ds_deadlist, tx);
430 ASSERT(!dmu_objset_is_dirty(os, txg));
431 dmu_buf_rele(ds->ds_dbuf, ds);
432 }
433
434 start = gethrtime();
435 while (dd = txg_list_remove(&dp->dp_dirty_dirs, txg))
436 dsl_dir_sync(dd, tx);
437 write_time += gethrtime() - start;
438
439 /*
440 * The MOS's space is accounted for in the pool/$MOS
441 * (dp_mos_dir). We can't modify the mos while we're syncing
442 * it, so we remember the deltas and apply them here.
443 */
444 if (dp->dp_mos_used_delta != 0 || dp->dp_mos_compressed_delta != 0 ||
445 dp->dp_mos_uncompressed_delta != 0) {
446 dsl_dir_diduse_space(dp->dp_mos_dir, DD_USED_HEAD,
447 dp->dp_mos_used_delta,
448 dp->dp_mos_compressed_delta,
449 dp->dp_mos_uncompressed_delta, tx);
450 dp->dp_mos_used_delta = 0;
451 dp->dp_mos_compressed_delta = 0;
452 dp->dp_mos_uncompressed_delta = 0;
453 }
454
455 start = gethrtime();
456 if (list_head(&mos->os_dirty_dnodes[txg & TXG_MASK]) != NULL ||
457 list_head(&mos->os_free_dnodes[txg & TXG_MASK]) != NULL) {
458 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
459 dmu_objset_sync(mos, zio, tx);
460 err = zio_wait(zio);
461 ASSERT(err == 0);
462 dprintf_bp(&dp->dp_meta_rootbp, "meta objset rootbp is %s", "");
463 spa_set_rootblkptr(dp->dp_spa, &dp->dp_meta_rootbp);
464 }
465 write_time += gethrtime() - start;
466 DTRACE_PROBE2(pool_sync__4io, hrtime_t, write_time,
467 hrtime_t, dp->dp_read_overhead);
468 write_time -= dp->dp_read_overhead;
469
470 /*
471 * If we modify a dataset in the same txg that we want to destroy it,
472 * its dsl_dir's dd_dbuf will be dirty, and thus have a hold on it.
473 * dsl_dir_destroy_check() will fail if there are unexpected holds.
474 * Therefore, we want to sync the MOS (thus syncing the dd_dbuf
475 * and clearing the hold on it) before we process the sync_tasks.
476 * The MOS data dirtied by the sync_tasks will be synced on the next
477 * pass.
478 */
479 DTRACE_PROBE(pool_sync__3task);
480 if (!txg_list_empty(&dp->dp_sync_tasks, txg)) {
481 dsl_sync_task_t *dst;
482 /*
483 * No more sync tasks should have been added while we
484 * were syncing.
485 */
486 ASSERT(spa_sync_pass(dp->dp_spa) == 1);
487 while (dst = txg_list_remove(&dp->dp_sync_tasks, txg))
488 dsl_sync_task_sync(dst, tx);
489 }
490
491 dmu_tx_commit(tx);
492
493 dp->dp_space_towrite[txg & TXG_MASK] = 0;
494 ASSERT(dp->dp_tempreserved[txg & TXG_MASK] == 0);
495
496 /*
497 * If the write limit max has not been explicitly set, set it
498 * to a fraction of available physical memory (default 1/8th).
499 * Note that we must inflate the limit because the spa
500 * inflates write sizes to account for data replication.
501 * Check this each sync phase to catch changing memory size.
502 */
503 if (physmem != old_physmem && zfs_write_limit_shift) {
504 mutex_enter(&zfs_write_limit_lock);
505 old_physmem = physmem;
506 zfs_write_limit_max = ptob(physmem) >> zfs_write_limit_shift;
507 zfs_write_limit_inflated = MAX(zfs_write_limit_min,
508 spa_get_asize(dp->dp_spa, zfs_write_limit_max));
509 mutex_exit(&zfs_write_limit_lock);
510 }
511
512 /*
513 * Attempt to keep the sync time consistent by adjusting the
514 * amount of write traffic allowed into each transaction group.
515 * Weight the throughput calculation towards the current value:
516 * thru = 3/4 old_thru + 1/4 new_thru
517 *
518 * Note: write_time is in nanosecs while dp_throughput is expressed in
519 * bytes per millisecond.
520 */
521 ASSERT(zfs_write_limit_min > 0);
522 if (data_written > zfs_write_limit_min / 8 &&
523 write_time > MSEC2NSEC(1)) {
524 uint64_t throughput = data_written / NSEC2MSEC(write_time);
525
526 if (dp->dp_throughput)
527 dp->dp_throughput = throughput / 4 +
528 3 * dp->dp_throughput / 4;
529 else
530 dp->dp_throughput = throughput;
531 dp->dp_write_limit = MIN(zfs_write_limit_inflated,
532 MAX(zfs_write_limit_min,
533 dp->dp_throughput * zfs_txg_synctime_ms));
534 }
535 }
536
537 void
538 dsl_pool_sync_done(dsl_pool_t *dp, uint64_t txg)
539 {
540 zilog_t *zilog;
541 dsl_dataset_t *ds;
542
543 while (zilog = txg_list_remove(&dp->dp_dirty_zilogs, txg)) {
544 ds = dmu_objset_ds(zilog->zl_os);
545 zil_clean(zilog, txg);
546 ASSERT(!dmu_objset_is_dirty(zilog->zl_os, txg));
547 dmu_buf_rele(ds->ds_dbuf, zilog);
548 }
549 ASSERT(!dmu_objset_is_dirty(dp->dp_meta_objset, txg));
550 }
551
552 /*
553 * TRUE if the current thread is the tx_sync_thread or if we
554 * are being called from SPA context during pool initialization.
555 */
556 int
557 dsl_pool_sync_context(dsl_pool_t *dp)
558 {
559 return (curthread == dp->dp_tx.tx_sync_thread ||
560 spa_is_initializing(dp->dp_spa));
561 }
562
563 uint64_t
564 dsl_pool_adjustedsize(dsl_pool_t *dp, boolean_t netfree)
566 uint64_t space, resv;
567
568 /*
569 * Reserve about 1.6% (1/64), or at least 32MB, for allocation
570 * efficiency.
571 * XXX The intent log is not accounted for, so it must fit
572 * within this slop.
573 *
574 * If we're trying to assess whether it's OK to do a free,
575 * cut the reservation in half to allow forward progress
576 * (e.g. make it possible to rm(1) files from a full pool).
577 */
578 space = spa_get_dspace(dp->dp_spa);
579 resv = MAX(space >> 6, SPA_MINDEVSIZE >> 1);
580 if (netfree)
581 resv >>= 1;
582
583 return (space - resv);
584 }
585
586 int
587 dsl_pool_tempreserve_space(dsl_pool_t *dp, uint64_t space, dmu_tx_t *tx)
588 {
589 uint64_t reserved = 0;
590 uint64_t write_limit = (zfs_write_limit_override ?
591 zfs_write_limit_override : dp->dp_write_limit);
592
593 if (zfs_no_write_throttle) {
594 atomic_add_64(&dp->dp_tempreserved[tx->tx_txg & TXG_MASK],
595 space);
596 return (0);
597 }
598
599 /*
600 * Check to see if we have exceeded the maximum allowed IO for
601 * this transaction group. We can do this without locks since
602 * a little slop here is ok. Note that we do the reserved check
603 * with only half the requested reserve: this is because the
604 * reserve requests are worst-case, and we really don't want to
605 * throttle based off of worst-case estimates.
606 */
607 if (write_limit > 0) {
608 reserved = dp->dp_space_towrite[tx->tx_txg & TXG_MASK]
609 + dp->dp_tempreserved[tx->tx_txg & TXG_MASK] / 2;
610
611 if (reserved && reserved > write_limit)
612 return (SET_ERROR(ERESTART));
613 }
614
615 atomic_add_64(&dp->dp_tempreserved[tx->tx_txg & TXG_MASK], space);
616
617 /*
618 * If this transaction group is over 7/8ths capacity, delay
619 * the caller 1 clock tick. This will slow down the "fill"
620 * rate until the sync process can catch up with us.
621 */
622 if (reserved && reserved > (write_limit - (write_limit >> 3))) {
623 txg_delay(dp, tx->tx_txg, zfs_throttle_delay,
624 zfs_throttle_resolution);
625 }
626
627 return (0);
628 }
629
630 void
631 dsl_pool_tempreserve_clear(dsl_pool_t *dp, int64_t space, dmu_tx_t *tx)
632 {
633 ASSERT(dp->dp_tempreserved[tx->tx_txg & TXG_MASK] >= space);
634 atomic_add_64(&dp->dp_tempreserved[tx->tx_txg & TXG_MASK], -space);
635 }
636
637 void
638 dsl_pool_memory_pressure(dsl_pool_t *dp)
639 {
640 uint64_t space_inuse = 0;
641 int i;
642
643 if (dp->dp_write_limit == zfs_write_limit_min)
644 return;
645
646 for (i = 0; i < TXG_SIZE; i++) {
647 space_inuse += dp->dp_space_towrite[i];
648 space_inuse += dp->dp_tempreserved[i];
649 }
650 dp->dp_write_limit = MAX(zfs_write_limit_min,
651 MIN(dp->dp_write_limit, space_inuse / 4));
652 }
653
654 void
655 dsl_pool_willuse_space(dsl_pool_t *dp, int64_t space, dmu_tx_t *tx)
656 {
657 if (space > 0) {
658 mutex_enter(&dp->dp_lock);
659 dp->dp_space_towrite[tx->tx_txg & TXG_MASK] += space;
660 mutex_exit(&dp->dp_lock);
661 }
662 }
663
664 /* ARGSUSED */
665 static int
666 upgrade_clones_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg)
667 {
668 dmu_tx_t *tx = arg;
669 dsl_dataset_t *ds, *prev = NULL;
670 int err;
671
672 err = dsl_dataset_hold_obj(dp, hds->ds_object, FTAG, &ds);
673 if (err)
674 return (err);
675
676 while (ds->ds_phys->ds_prev_snap_obj != 0) {
677 err = dsl_dataset_hold_obj(dp, ds->ds_phys->ds_prev_snap_obj,
678 FTAG, &prev);
679 if (err) {
680 dsl_dataset_rele(ds, FTAG);
681 return (err);
|
29 #include <sys/dsl_prop.h>
30 #include <sys/dsl_dir.h>
31 #include <sys/dsl_synctask.h>
32 #include <sys/dsl_scan.h>
33 #include <sys/dnode.h>
34 #include <sys/dmu_tx.h>
35 #include <sys/dmu_objset.h>
36 #include <sys/arc.h>
37 #include <sys/zap.h>
38 #include <sys/zio.h>
39 #include <sys/zfs_context.h>
40 #include <sys/fs/zfs.h>
41 #include <sys/zfs_znode.h>
42 #include <sys/spa_impl.h>
43 #include <sys/dsl_deadlist.h>
44 #include <sys/bptree.h>
45 #include <sys/zfeature.h>
46 #include <sys/zil_impl.h>
47 #include <sys/dsl_userhold.h>
48
49 /*
50 * ZFS Write Throttle
51 * ------------------
52 *
53 * ZFS must limit the rate of incoming writes to the rate at which it is able
54 * to sync data modifications to the backend storage. Throttling by too much
55 * creates an artificial limit; throttling by too little can only be sustained
56 * for short periods and would lead to highly lumpy performance. On a per-pool
57 * basis, ZFS tracks the amount of modified (dirty) data. As operations change
58 * data, the amount of dirty data increases; as ZFS syncs out data, the amount
59 * of dirty data decreases. When the amount of dirty data exceeds a
60 * predetermined threshold further modifications are blocked until the amount
61 * of dirty data decreases (as data is synced out).
62 *
63 * The limit on dirty data is tunable, and should be adjusted according to
64 * both the IO capacity and available memory of the system. The larger the
65 * window, the more ZFS is able to aggregate and amortize metadata (and data)
66 * changes. However, memory is a limited resource, and allowing for more dirty
67 * data comes at the cost of keeping other useful data in memory (for example
68 * ZFS data cached by the ARC).
69 *
70 * Implementation
71 *
72 * As buffers are modified dsl_pool_willuse_space() increments both the per-
73 * txg (dp_dirty_pertxg[]) and poolwide (dp_dirty_total) accounting of
74 * dirty space used; dsl_pool_dirty_space() decrements those values as data
75 * is synced out from dsl_pool_sync(). While only the poolwide value is
76 * relevant, the per-txg value is useful for debugging. The tunable
77 * zfs_dirty_data_max determines the dirty space limit. Once that value is
78 * exceeded, new writes are halted until space frees up.
79 *
80 * The zfs_dirty_data_sync tunable dictates the threshold at which we
81 * ensure that there is a txg syncing (see the comment in txg.c for a full
82 * description of transaction group stages).
83 *
84 * The IO scheduler uses both the dirty space limit and current amount of
85 * dirty data as inputs. Those values affect the number of concurrent IOs ZFS
86 * issues. See the comment in vdev_queue.c for details of the IO scheduler.
87 *
88 * The delay is also calculated based on the amount of dirty data. See the
89 * comment above dmu_tx_delay() for details.
90 */
91
92 /*
93 * zfs_dirty_data_max will be set to zfs_dirty_data_max_percent% of all memory,
94 * capped at zfs_dirty_data_max_max. It can also be overridden in /etc/system.
95 */
96 uint64_t zfs_dirty_data_max;
97 uint64_t zfs_dirty_data_max_max = 4ULL * 1024 * 1024 * 1024;
98 int zfs_dirty_data_max_percent = 10;
99
100 /*
101 * If there is at least this much dirty data, push out a txg.
102 */
103 uint64_t zfs_dirty_data_sync = 64 * 1024 * 1024;
104
105 /*
106 * Once there is this amount of dirty data, the dmu_tx_delay() will kick in
107 * and delay each transaction.
108 * This value should be >= zfs_vdev_async_write_active_max_dirty_percent.
109 */
110 int zfs_delay_min_dirty_percent = 60;
111
112 /*
113 * This controls how quickly the delay approaches infinity.
114 * Larger values cause it to delay less for a given amount of dirty data.
115 * Therefore larger values will cause there to be more dirty data for a
116 * given throughput.
117 *
118 * For the smoothest delay, this value should be about 1 billion divided
119 * by the maximum number of operations per second. This will smoothly
120 * handle between 10x and 1/10th this number.
121 *
122 * Note: zfs_delay_scale * zfs_dirty_data_max must be < 2^64, due to the
123 * multiply in dmu_tx_delay().
124 */
125 uint64_t zfs_delay_scale = 1000 * 1000 * 1000 / 2000;
126
127
128 /*
129 * XXX someday maybe turn these into #defines, and you have to tune it on a
130 * per-pool basis using zfs.conf.
131 */
132
133
134 hrtime_t zfs_throttle_delay = MSEC2NSEC(10);
135 hrtime_t zfs_throttle_resolution = MSEC2NSEC(10);
136
137 int
138 dsl_pool_open_special_dir(dsl_pool_t *dp, const char *name, dsl_dir_t **ddp)
139 {
140 uint64_t obj;
141 int err;
142
143 err = zap_lookup(dp->dp_meta_objset,
144 dp->dp_root_dir->dd_phys->dd_child_dir_zapobj,
145 name, sizeof (obj), 1, &obj);
146 if (err)
147 return (err);
148
149 return (dsl_dir_hold_obj(dp, obj, name, dp, ddp));
150 }
151
152 static dsl_pool_t *
153 dsl_pool_open_impl(spa_t *spa, uint64_t txg)
154 {
155 dsl_pool_t *dp;
156 blkptr_t *bp = spa_get_rootblkptr(spa);
157
158 dp = kmem_zalloc(sizeof (dsl_pool_t), KM_SLEEP);
159 dp->dp_spa = spa;
160 dp->dp_meta_rootbp = *bp;
161 rrw_init(&dp->dp_config_rwlock, B_TRUE);
162 txg_init(dp, txg);
163
164 txg_list_create(&dp->dp_dirty_datasets,
165 offsetof(dsl_dataset_t, ds_dirty_link));
166 txg_list_create(&dp->dp_dirty_zilogs,
167 offsetof(zilog_t, zl_dirty_link));
168 txg_list_create(&dp->dp_dirty_dirs,
169 offsetof(dsl_dir_t, dd_dirty_link));
170 txg_list_create(&dp->dp_sync_tasks,
171 offsetof(dsl_sync_task_t, dst_node));
172
173 mutex_init(&dp->dp_lock, NULL, MUTEX_DEFAULT, NULL);
174 cv_init(&dp->dp_spaceavail_cv, NULL, CV_DEFAULT, NULL);
175
176 dp->dp_vnrele_taskq = taskq_create("zfs_vn_rele_taskq", 1, minclsyspri,
177 1, 4, 0);
178
179 return (dp);
180 }
181
182 int
183 dsl_pool_init(spa_t *spa, uint64_t txg, dsl_pool_t **dpp)
184 {
185 int err;
186 dsl_pool_t *dp = dsl_pool_open_impl(spa, txg);
187
188 err = dmu_objset_open_impl(spa, NULL, &dp->dp_meta_rootbp,
189 &dp->dp_meta_objset);
190 if (err != 0)
191 dsl_pool_close(dp);
192 else
193 *dpp = dp;
194
269 }
270
271 err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT,
272 DMU_POOL_TMP_USERREFS, sizeof (uint64_t), 1,
273 &dp->dp_tmp_userrefs_obj);
274 if (err == ENOENT)
275 err = 0;
276 if (err)
277 goto out;
278
279 err = dsl_scan_init(dp, dp->dp_tx.tx_open_txg);
280
281 out:
282 rrw_exit(&dp->dp_config_rwlock, FTAG);
283 return (err);
284 }
285
286 void
287 dsl_pool_close(dsl_pool_t *dp)
288 {
289 /*
290 * Drop our references from dsl_pool_open().
291 *
292 * Since we held the origin_snap from "syncing" context (which
293 * includes pool-opening context), it actually only got a "ref"
294 * and not a hold, so just drop that here.
295 */
296 if (dp->dp_origin_snap)
297 dsl_dataset_rele(dp->dp_origin_snap, dp);
298 if (dp->dp_mos_dir)
299 dsl_dir_rele(dp->dp_mos_dir, dp);
300 if (dp->dp_free_dir)
301 dsl_dir_rele(dp->dp_free_dir, dp);
302 if (dp->dp_root_dir)
303 dsl_dir_rele(dp->dp_root_dir, dp);
304
305 bpobj_close(&dp->dp_free_bpobj);
306
307 /* undo the dmu_objset_open_impl(mos) from dsl_pool_open() */
308 if (dp->dp_meta_objset)
309 dmu_objset_evict(dp->dp_meta_objset);
310
311 txg_list_destroy(&dp->dp_dirty_datasets);
401 void
402 dsl_pool_mos_diduse_space(dsl_pool_t *dp,
403 int64_t used, int64_t comp, int64_t uncomp)
404 {
405 ASSERT3U(comp, ==, uncomp); /* it's all metadata */
406 mutex_enter(&dp->dp_lock);
407 dp->dp_mos_used_delta += used;
408 dp->dp_mos_compressed_delta += comp;
409 dp->dp_mos_uncompressed_delta += uncomp;
410 mutex_exit(&dp->dp_lock);
411 }
412
413 static int
414 deadlist_enqueue_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
415 {
416 dsl_deadlist_t *dl = arg;
417 dsl_deadlist_insert(dl, bp, tx);
418 return (0);
419 }
420
421 static void
422 dsl_pool_sync_mos(dsl_pool_t *dp, dmu_tx_t *tx)
423 {
424 zio_t *zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
425 dmu_objset_sync(dp->dp_meta_objset, zio, tx);
426 VERIFY0(zio_wait(zio));
427 dprintf_bp(&dp->dp_meta_rootbp, "meta objset rootbp is %s", "");
428 spa_set_rootblkptr(dp->dp_spa, &dp->dp_meta_rootbp);
429 }
430
431 static void
432 dsl_pool_dirty_delta(dsl_pool_t *dp, int64_t delta)
433 {
434 ASSERT(MUTEX_HELD(&dp->dp_lock));
435
436 if (delta < 0)
437 ASSERT3U(-delta, <=, dp->dp_dirty_total);
438
439 dp->dp_dirty_total += delta;
440
441 /*
442 * Note: we signal even when increasing dp_dirty_total.
443 * This ensures forward progress -- each thread wakes the next waiter.
444 */
445 if (dp->dp_dirty_total <= zfs_dirty_data_max)
446 cv_signal(&dp->dp_spaceavail_cv);
447 }
448
449 void
450 dsl_pool_sync(dsl_pool_t *dp, uint64_t txg)
451 {
452 zio_t *zio;
453 dmu_tx_t *tx;
454 dsl_dir_t *dd;
455 dsl_dataset_t *ds;
456 objset_t *mos = dp->dp_meta_objset;
457 list_t synced_datasets;
458
459 list_create(&synced_datasets, sizeof (dsl_dataset_t),
460 offsetof(dsl_dataset_t, ds_synced_link));
461
462 tx = dmu_tx_create_assigned(dp, txg);
463
464 /*
465 * Write out all dirty blocks of dirty datasets.
466 */
467 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
468 while ((ds = txg_list_remove(&dp->dp_dirty_datasets, txg)) != NULL) {
469 /*
470 * We must not sync any non-MOS datasets twice, because
471 * we may have taken a snapshot of them. However, we
472 * may sync newly-created datasets on pass 2.
473 */
474 ASSERT(!list_link_active(&ds->ds_synced_link));
475 list_insert_tail(&synced_datasets, ds);
476 dsl_dataset_sync(ds, zio, tx);
477 }
478 VERIFY0(zio_wait(zio));
479
480 /*
481 * We have written all of the accounted dirty data, so our
482 * dp_space_towrite should now be zero. However, some seldom-used
483 * code paths do not adhere to this (e.g. dbuf_undirty(), also
484 * rounding error in dbuf_write_physdone).
485 * Shore up the accounting of any dirtied space now.
486 */
487 dsl_pool_undirty_space(dp, dp->dp_dirty_pertxg[txg & TXG_MASK], txg);
488
489 /*
490 * After the data blocks have been written (ensured by the zio_wait()
491 * above), update the user/group space accounting.
492 */
493 for (ds = list_head(&synced_datasets); ds != NULL;
494 ds = list_next(&synced_datasets, ds)) {
495 dmu_objset_do_userquota_updates(ds->ds_objset, tx);
496 }
497
498 /*
499 * Sync the datasets again to push out the changes due to
500 * userspace updates. This must be done before we process the
501 * sync tasks, so that any snapshots will have the correct
502 * user accounting information (and we won't get confused
503 * about which blocks are part of the snapshot).
504 */
505 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
506 while ((ds = txg_list_remove(&dp->dp_dirty_datasets, txg)) != NULL) {
507 ASSERT(list_link_active(&ds->ds_synced_link));
508 dmu_buf_rele(ds->ds_dbuf, ds);
509 dsl_dataset_sync(ds, zio, tx);
510 }
511 VERIFY0(zio_wait(zio));
512
513 /*
514 * Now that the datasets have been completely synced, we can
515 * clean up our in-memory structures accumulated while syncing:
516 *
517 * - move dead blocks from the pending deadlist to the on-disk deadlist
518 * - release hold from dsl_dataset_dirty()
519 */
520 while ((ds = list_remove_head(&synced_datasets)) != NULL) {
521 objset_t *os = ds->ds_objset;
522 bplist_iterate(&ds->ds_pending_deadlist,
523 deadlist_enqueue_cb, &ds->ds_deadlist, tx);
524 ASSERT(!dmu_objset_is_dirty(os, txg));
525 dmu_buf_rele(ds->ds_dbuf, ds);
526 }
527 while ((dd = txg_list_remove(&dp->dp_dirty_dirs, txg)) != NULL) {
528 dsl_dir_sync(dd, tx);
529 }
530
531 /*
532 * The MOS's space is accounted for in the pool/$MOS
533 * (dp_mos_dir). We can't modify the mos while we're syncing
534 * it, so we remember the deltas and apply them here.
535 */
536 if (dp->dp_mos_used_delta != 0 || dp->dp_mos_compressed_delta != 0 ||
537 dp->dp_mos_uncompressed_delta != 0) {
538 dsl_dir_diduse_space(dp->dp_mos_dir, DD_USED_HEAD,
539 dp->dp_mos_used_delta,
540 dp->dp_mos_compressed_delta,
541 dp->dp_mos_uncompressed_delta, tx);
542 dp->dp_mos_used_delta = 0;
543 dp->dp_mos_compressed_delta = 0;
544 dp->dp_mos_uncompressed_delta = 0;
545 }
546
547 if (list_head(&mos->os_dirty_dnodes[txg & TXG_MASK]) != NULL ||
548 list_head(&mos->os_free_dnodes[txg & TXG_MASK]) != NULL) {
549 dsl_pool_sync_mos(dp, tx);
550 }
551
552 /*
553 * If we modify a dataset in the same txg that we want to destroy it,
554 * its dsl_dir's dd_dbuf will be dirty, and thus have a hold on it.
555 * dsl_dir_destroy_check() will fail if there are unexpected holds.
556 * Therefore, we want to sync the MOS (thus syncing the dd_dbuf
557 * and clearing the hold on it) before we process the sync_tasks.
558 * The MOS data dirtied by the sync_tasks will be synced on the next
559 * pass.
560 */
561 if (!txg_list_empty(&dp->dp_sync_tasks, txg)) {
562 dsl_sync_task_t *dst;
563 /*
564 * No more sync tasks should have been added while we
565 * were syncing.
566 */
567 ASSERT3U(spa_sync_pass(dp->dp_spa), ==, 1);
568 while ((dst = txg_list_remove(&dp->dp_sync_tasks, txg)) != NULL)
569 dsl_sync_task_sync(dst, tx);
570 }
571
572 dmu_tx_commit(tx);
573
574 DTRACE_PROBE2(dsl_pool_sync__done, dsl_pool_t *dp, dp, uint64_t, txg);
575 }
576
577 void
578 dsl_pool_sync_done(dsl_pool_t *dp, uint64_t txg)
579 {
580 zilog_t *zilog;
581
582 while (zilog = txg_list_remove(&dp->dp_dirty_zilogs, txg)) {
583 dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os);
584 zil_clean(zilog, txg);
585 ASSERT(!dmu_objset_is_dirty(zilog->zl_os, txg));
586 dmu_buf_rele(ds->ds_dbuf, zilog);
587 }
588 ASSERT(!dmu_objset_is_dirty(dp->dp_meta_objset, txg));
589 }
590
591 /*
592 * TRUE if the current thread is the tx_sync_thread or if we
593 * are being called from SPA context during pool initialization.
594 */
595 int
596 dsl_pool_sync_context(dsl_pool_t *dp)
597 {
598 return (curthread == dp->dp_tx.tx_sync_thread ||
599 spa_is_initializing(dp->dp_spa));
600 }
601
602 uint64_t
603 dsl_pool_adjustedsize(dsl_pool_t *dp, boolean_t netfree)
605 uint64_t space, resv;
606
607 /*
608 * Reserve about 1.6% (1/64), or at least 32MB, for allocation
609 * efficiency.
610 * XXX The intent log is not accounted for, so it must fit
611 * within this slop.
612 *
613 * If we're trying to assess whether it's OK to do a free,
614 * cut the reservation in half to allow forward progress
615 * (e.g. make it possible to rm(1) files from a full pool).
616 */
617 space = spa_get_dspace(dp->dp_spa);
618 resv = MAX(space >> 6, SPA_MINDEVSIZE >> 1);
619 if (netfree)
620 resv >>= 1;
621
622 return (space - resv);
623 }
624
625 boolean_t
626 dsl_pool_need_dirty_delay(dsl_pool_t *dp)
627 {
628 uint64_t delay_min_bytes =
629 zfs_dirty_data_max * zfs_delay_min_dirty_percent / 100;
630 boolean_t rv;
631
632 mutex_enter(&dp->dp_lock);
633 if (dp->dp_dirty_total > zfs_dirty_data_sync)
634 txg_kick(dp);
635 rv = (dp->dp_dirty_total > delay_min_bytes);
636 mutex_exit(&dp->dp_lock);
637 return (rv);
638 }
639
640 void
641 dsl_pool_dirty_space(dsl_pool_t *dp, int64_t space, dmu_tx_t *tx)
642 {
643 if (space > 0) {
644 mutex_enter(&dp->dp_lock);
645 dp->dp_dirty_pertxg[tx->tx_txg & TXG_MASK] += space;
646 dsl_pool_dirty_delta(dp, space);
647 mutex_exit(&dp->dp_lock);
648 }
649 }
650
651 void
652 dsl_pool_undirty_space(dsl_pool_t *dp, int64_t space, uint64_t txg) {
653 ASSERT3S(space, >=, 0);
654 if (space == 0)
655 return;
656 mutex_enter(&dp->dp_lock);
657 if (dp->dp_dirty_pertxg[txg & TXG_MASK] < space) {
658 /* XXX writing something we didn't dirty? */
659 space = dp->dp_dirty_pertxg[txg & TXG_MASK];
660 }
661 ASSERT3U(dp->dp_dirty_pertxg[txg & TXG_MASK], >=, space);
662 dp->dp_dirty_pertxg[txg & TXG_MASK] -= space;
663 ASSERT3U(dp->dp_dirty_total, >=, space);
664 dsl_pool_dirty_delta(dp, -space);
665 mutex_exit(&dp->dp_lock);
666 }
667
668 /* ARGSUSED */
669 static int
670 upgrade_clones_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg)
671 {
672 dmu_tx_t *tx = arg;
673 dsl_dataset_t *ds, *prev = NULL;
674 int err;
675
676 err = dsl_dataset_hold_obj(dp, hds->ds_object, FTAG, &ds);
677 if (err)
678 return (err);
679
680 while (ds->ds_phys->ds_prev_snap_obj != 0) {
681 err = dsl_dataset_hold_obj(dp, ds->ds_phys->ds_prev_snap_obj,
682 FTAG, &prev);
683 if (err) {
684 dsl_dataset_rele(ds, FTAG);
685 return (err);
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