]> git.proxmox.com Git - mirror_zfs.git/blobdiff - module/zfs/spa.c
zpool import progress kstat
[mirror_zfs.git] / module / zfs / spa.c
index a1851bca25abeb34cb4694935e06103db770ecaf..eb3ff91a073c8af8c3365d8beb5ff4154abc8f52 100644 (file)
@@ -21,7 +21,7 @@
 
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2011, 2017 by Delphix. All rights reserved.
+ * Copyright (c) 2011, 2019 by Delphix. All rights reserved.
  * Copyright (c) 2018, Nexenta Systems, Inc.  All rights reserved.
  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
  * Copyright 2013 Saso Kiselkov. All rights reserved.
@@ -56,6 +56,8 @@
 #include <sys/vdev_removal.h>
 #include <sys/vdev_indirect_mapping.h>
 #include <sys/vdev_indirect_births.h>
+#include <sys/vdev_initialize.h>
+#include <sys/vdev_trim.h>
 #include <sys/vdev_disk.h>
 #include <sys/metaslab.h>
 #include <sys/metaslab_impl.h>
@@ -131,7 +133,7 @@ static const char *const zio_taskq_types[ZIO_TASKQ_TYPES] = {
  * number of threads assigned to their taskqs using the ZTI_N(#) or ZTI_ONE
  * macros. Other operations process a large amount of data; the ZTI_BATCH
  * macro causes us to create a taskq oriented for throughput. Some operations
- * are so high frequency and short-lived that the taskq itself can become a a
+ * are so high frequency and short-lived that the taskq itself can become a
  * point of lock contention. The ZTI_P(#, #) macro indicates that we need an
  * additional degree of parallelism specified by the number of threads per-
  * taskq and the number of taskqs; when dispatching an event in this case, the
@@ -149,6 +151,7 @@ const zio_taskq_info_t zio_taskqs[ZIO_TYPES][ZIO_TASKQ_TYPES] = {
        { ZTI_P(12, 8), ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* FREE */
        { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* CLAIM */
        { ZTI_ONE,      ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* IOCTL */
+       { ZTI_N(4),     ZTI_NULL,       ZTI_ONE,        ZTI_NULL }, /* TRIM */
 };
 
 static void spa_sync_version(void *arg, dmu_tx_t *tx);
@@ -434,8 +437,9 @@ spa_prop_get(spa_t *spa, nvlist_t **nvp)
 
                                dp = spa_get_dsl(spa);
                                dsl_pool_config_enter(dp, FTAG);
-                               if ((err = dsl_dataset_hold_obj(dp,
-                                   za.za_first_integer, FTAG, &ds))) {
+                               err = dsl_dataset_hold_obj(dp,
+                                   za.za_first_integer, FTAG, &ds);
+                               if (err != 0) {
                                        dsl_pool_config_exit(dp, FTAG);
                                        break;
                                }
@@ -552,6 +556,7 @@ spa_prop_validate(spa_t *spa, nvlist_t *props)
                case ZPOOL_PROP_AUTOREPLACE:
                case ZPOOL_PROP_LISTSNAPS:
                case ZPOOL_PROP_AUTOEXPAND:
+               case ZPOOL_PROP_AUTOTRIM:
                        error = nvpair_value_uint64(elem, &intval);
                        if (!error && intval > 1)
                                error = SET_ERROR(EINVAL);
@@ -601,14 +606,14 @@ spa_prop_validate(spa_t *spa, nvlist_t *props)
                                }
 
                                error = dmu_objset_hold(strval, FTAG, &os);
-                               if (error)
+                               if (error != 0)
                                        break;
 
                                /*
                                 * Must be ZPL, and its property settings
                                 * must be supported by GRUB (compression
-                                * is not gzip, and large blocks or large
-                                * dnodes are not used).
+                                * is not gzip, and large dnodes are not
+                                * used).
                                 */
 
                                if (dmu_objset_type(os) != DMU_OST_ZFS) {
@@ -1218,8 +1223,10 @@ spa_activate(spa_t *spa, int mode)
                spa_create_zio_taskqs(spa);
        }
 
-       for (size_t i = 0; i < TXG_SIZE; i++)
-               spa->spa_txg_zio[i] = zio_root(spa, NULL, NULL, 0);
+       for (size_t i = 0; i < TXG_SIZE; i++) {
+               spa->spa_txg_zio[i] = zio_root(spa, NULL, NULL,
+                   ZIO_FLAG_CANFAIL);
+       }
 
        list_create(&spa->spa_config_dirty_list, sizeof (vdev_t),
            offsetof(vdev_t, vdev_config_dirty_node));
@@ -1430,6 +1437,7 @@ spa_unload(spa_t *spa)
 
        ASSERT(MUTEX_HELD(&spa_namespace_lock));
 
+       spa_import_progress_remove(spa_guid(spa));
        spa_load_note(spa, "UNLOADING");
 
        /*
@@ -1437,6 +1445,13 @@ spa_unload(spa_t *spa)
         */
        spa_async_suspend(spa);
 
+       if (spa->spa_root_vdev) {
+               vdev_t *root_vdev = spa->spa_root_vdev;
+               vdev_initialize_stop_all(root_vdev, VDEV_INITIALIZE_ACTIVE);
+               vdev_trim_stop_all(root_vdev, VDEV_TRIM_ACTIVE);
+               vdev_autotrim_stop_all(spa);
+       }
+
        /*
         * Stop syncing.
         */
@@ -1452,10 +1467,10 @@ spa_unload(spa_t *spa)
         * calling taskq_wait(mg_taskq).
         */
        if (spa->spa_root_vdev != NULL) {
-               spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
+               spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
                for (int c = 0; c < spa->spa_root_vdev->vdev_children; c++)
                        vdev_metaslab_fini(spa->spa_root_vdev->vdev_child[c]);
-               spa_config_exit(spa, SCL_ALL, FTAG);
+               spa_config_exit(spa, SCL_ALL, spa);
        }
 
        if (spa->spa_mmp.mmp_thread)
@@ -1477,13 +1492,11 @@ spa_unload(spa_t *spa)
        }
 
        if (spa->spa_condense_zthr != NULL) {
-               ASSERT(!zthr_isrunning(spa->spa_condense_zthr));
                zthr_destroy(spa->spa_condense_zthr);
                spa->spa_condense_zthr = NULL;
        }
 
        if (spa->spa_checkpoint_discard_zthr != NULL) {
-               ASSERT(!zthr_isrunning(spa->spa_checkpoint_discard_zthr));
                zthr_destroy(spa->spa_checkpoint_discard_zthr);
                spa->spa_checkpoint_discard_zthr = NULL;
        }
@@ -1492,7 +1505,7 @@ spa_unload(spa_t *spa)
 
        bpobj_close(&spa->spa_deferred_bpobj);
 
-       spa_config_enter(spa, SCL_ALL, FTAG, RW_WRITER);
+       spa_config_enter(spa, SCL_ALL, spa, RW_WRITER);
 
        /*
         * Close all vdevs.
@@ -1554,7 +1567,7 @@ spa_unload(spa_t *spa)
                spa->spa_comment = NULL;
        }
 
-       spa_config_exit(spa, SCL_ALL, FTAG);
+       spa_config_exit(spa, SCL_ALL, spa);
 }
 
 /*
@@ -2363,6 +2376,8 @@ spa_load(spa_t *spa, spa_load_state_t state, spa_import_type_t type)
        int error;
 
        spa->spa_load_state = state;
+       (void) spa_import_progress_set_state(spa_guid(spa),
+           spa_load_state(spa));
 
        gethrestime(&spa->spa_loaded_ts);
        error = spa_load_impl(spa, type, &ereport);
@@ -2385,6 +2400,9 @@ spa_load(spa_t *spa, spa_load_state_t state, spa_import_type_t type)
        spa->spa_load_state = error ? SPA_LOAD_ERROR : SPA_LOAD_NONE;
        spa->spa_ena = 0;
 
+       (void) spa_import_progress_set_state(spa_guid(spa),
+           spa_load_state(spa));
+
        return (error);
 }
 
@@ -2430,6 +2448,7 @@ spa_activity_check_required(spa_t *spa, uberblock_t *ub, nvlist_t *label,
        uint64_t hostid = 0;
        uint64_t tryconfig_txg = 0;
        uint64_t tryconfig_timestamp = 0;
+       uint16_t tryconfig_mmp_seq = 0;
        nvlist_t *nvinfo;
 
        if (nvlist_exists(config, ZPOOL_CONFIG_LOAD_INFO)) {
@@ -2438,6 +2457,8 @@ spa_activity_check_required(spa_t *spa, uberblock_t *ub, nvlist_t *label,
                    &tryconfig_txg);
                (void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_TIMESTAMP,
                    &tryconfig_timestamp);
+               (void) nvlist_lookup_uint16(nvinfo, ZPOOL_CONFIG_MMP_SEQ,
+                   &tryconfig_mmp_seq);
        }
 
        (void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_STATE, &state);
@@ -2454,14 +2475,17 @@ spa_activity_check_required(spa_t *spa, uberblock_t *ub, nvlist_t *label,
         */
        if (ub->ub_mmp_magic == MMP_MAGIC && ub->ub_mmp_delay == 0)
                return (B_FALSE);
+
        /*
-        * If the tryconfig_* values are nonzero, they are the results of an
-        * earlier tryimport.  If they match the uberblock we just found, then
-        * the pool has not changed and we return false so we do not test a
-        * second time.
+        * If the tryconfig_ values are nonzero, they are the results of an
+        * earlier tryimport.  If they all match the uberblock we just found,
+        * then the pool has not changed and we return false so we do not test
+        * second time.
         */
        if (tryconfig_txg && tryconfig_txg == ub->ub_txg &&
-           tryconfig_timestamp && tryconfig_timestamp == ub->ub_timestamp)
+           tryconfig_timestamp && tryconfig_timestamp == ub->ub_timestamp &&
+           tryconfig_mmp_seq && tryconfig_mmp_seq ==
+           (MMP_SEQ_VALID(ub) ? MMP_SEQ(ub) : 0))
                return (B_FALSE);
 
        /*
@@ -2484,6 +2508,76 @@ spa_activity_check_required(spa_t *spa, uberblock_t *ub, nvlist_t *label,
        return (B_TRUE);
 }
 
+/*
+ * Nanoseconds the activity check must watch for changes on-disk.
+ */
+static uint64_t
+spa_activity_check_duration(spa_t *spa, uberblock_t *ub)
+{
+       uint64_t import_intervals = MAX(zfs_multihost_import_intervals, 1);
+       uint64_t multihost_interval = MSEC2NSEC(
+           MMP_INTERVAL_OK(zfs_multihost_interval));
+       uint64_t import_delay = MAX(NANOSEC, import_intervals *
+           multihost_interval);
+
+       /*
+        * Local tunables determine a minimum duration except for the case
+        * where we know when the remote host will suspend the pool if MMP
+        * writes do not land.
+        *
+        * See Big Theory comment at the top of mmp.c for the reasoning behind
+        * these cases and times.
+        */
+
+       ASSERT(MMP_IMPORT_SAFETY_FACTOR >= 100);
+
+       if (MMP_INTERVAL_VALID(ub) && MMP_FAIL_INT_VALID(ub) &&
+           MMP_FAIL_INT(ub) > 0) {
+
+               /* MMP on remote host will suspend pool after failed writes */
+               import_delay = MMP_FAIL_INT(ub) * MSEC2NSEC(MMP_INTERVAL(ub)) *
+                   MMP_IMPORT_SAFETY_FACTOR / 100;
+
+               zfs_dbgmsg("fail_intvals>0 import_delay=%llu ub_mmp "
+                   "mmp_fails=%llu ub_mmp mmp_interval=%llu "
+                   "import_intervals=%u", import_delay, MMP_FAIL_INT(ub),
+                   MMP_INTERVAL(ub), import_intervals);
+
+       } else if (MMP_INTERVAL_VALID(ub) && MMP_FAIL_INT_VALID(ub) &&
+           MMP_FAIL_INT(ub) == 0) {
+
+               /* MMP on remote host will never suspend pool */
+               import_delay = MAX(import_delay, (MSEC2NSEC(MMP_INTERVAL(ub)) +
+                   ub->ub_mmp_delay) * import_intervals);
+
+               zfs_dbgmsg("fail_intvals=0 import_delay=%llu ub_mmp "
+                   "mmp_interval=%llu ub_mmp_delay=%llu "
+                   "import_intervals=%u", import_delay, MMP_INTERVAL(ub),
+                   ub->ub_mmp_delay, import_intervals);
+
+       } else if (MMP_VALID(ub)) {
+               /*
+                * zfs-0.7 compatability case
+                */
+
+               import_delay = MAX(import_delay, (multihost_interval +
+                   ub->ub_mmp_delay) * import_intervals);
+
+               zfs_dbgmsg("import_delay=%llu ub_mmp_delay=%llu "
+                   "import_intervals=%u leaves=%u", import_delay,
+                   ub->ub_mmp_delay, import_intervals,
+                   vdev_count_leaves(spa));
+       } else {
+               /* Using local tunings is the only reasonable option */
+               zfs_dbgmsg("pool last imported on non-MMP aware "
+                   "host using import_delay=%llu multihost_interval=%llu "
+                   "import_intervals=%u", import_delay, multihost_interval,
+                   import_intervals);
+       }
+
+       return (import_delay);
+}
+
 /*
  * Perform the import activity check.  If the user canceled the import or
  * we detected activity then fail.
@@ -2491,10 +2585,11 @@ spa_activity_check_required(spa_t *spa, uberblock_t *ub, nvlist_t *label,
 static int
 spa_activity_check(spa_t *spa, uberblock_t *ub, nvlist_t *config)
 {
-       uint64_t import_intervals = MAX(zfs_multihost_import_intervals, 1);
        uint64_t txg = ub->ub_txg;
        uint64_t timestamp = ub->ub_timestamp;
-       uint64_t import_delay = NANOSEC;
+       uint64_t mmp_config = ub->ub_mmp_config;
+       uint16_t mmp_seq = MMP_SEQ_VALID(ub) ? MMP_SEQ(ub) : 0;
+       uint64_t import_delay;
        hrtime_t import_expire;
        nvlist_t *mmp_label = NULL;
        vdev_t *rvd = spa->spa_root_vdev;
@@ -2511,7 +2606,7 @@ spa_activity_check(spa_t *spa, uberblock_t *ub, nvlist_t *config)
         * during the earlier tryimport.  If the txg recorded there is 0 then
         * the pool is known to be active on another host.
         *
-        * Otherwise, the pool might be in use on another node.  Check for
+        * Otherwise, the pool might be in use on another host.  Check for
         * changes in the uberblocks on disk if necessary.
         */
        if (nvlist_exists(config, ZPOOL_CONFIG_LOAD_INFO)) {
@@ -2526,32 +2621,28 @@ spa_activity_check(spa_t *spa, uberblock_t *ub, nvlist_t *config)
                }
        }
 
-       /*
-        * Preferentially use the zfs_multihost_interval from the node which
-        * last imported the pool.  This value is stored in an MMP uberblock as.
-        *
-        * ub_mmp_delay * vdev_count_leaves() == zfs_multihost_interval
-        */
-       if (ub->ub_mmp_magic == MMP_MAGIC && ub->ub_mmp_delay)
-               import_delay = MAX(import_delay, import_intervals *
-                   ub->ub_mmp_delay * MAX(vdev_count_leaves(spa), 1));
-
-       /* Apply a floor using the local default values. */
-       import_delay = MAX(import_delay, import_intervals *
-           MSEC2NSEC(MAX(zfs_multihost_interval, MMP_MIN_INTERVAL)));
-
-       zfs_dbgmsg("import_delay=%llu ub_mmp_delay=%llu import_intervals=%u "
-           "leaves=%u", import_delay, ub->ub_mmp_delay, import_intervals,
-           vdev_count_leaves(spa));
+       import_delay = spa_activity_check_duration(spa, ub);
 
        /* Add a small random factor in case of simultaneous imports (0-25%) */
-       import_expire = gethrtime() + import_delay +
-           (import_delay * spa_get_random(250) / 1000);
+       import_delay += import_delay * spa_get_random(250) / 1000;
+
+       import_expire = gethrtime() + import_delay;
 
        while (gethrtime() < import_expire) {
+               (void) spa_import_progress_set_mmp_check(spa_guid(spa),
+                   NSEC2SEC(import_expire - gethrtime()));
+
                vdev_uberblock_load(rvd, ub, &mmp_label);
 
-               if (txg != ub->ub_txg || timestamp != ub->ub_timestamp) {
+               if (txg != ub->ub_txg || timestamp != ub->ub_timestamp ||
+                   mmp_seq != (MMP_SEQ_VALID(ub) ? MMP_SEQ(ub) : 0)) {
+                       zfs_dbgmsg("multihost activity detected "
+                           "txg %llu ub_txg  %llu "
+                           "timestamp %llu ub_timestamp  %llu "
+                           "mmp_config %#llx ub_mmp_config %#llx",
+                           txg, ub->ub_txg, timestamp, ub->ub_timestamp,
+                           mmp_config, ub->ub_mmp_config);
+
                        error = SET_ERROR(EREMOTEIO);
                        break;
                }
@@ -2907,6 +2998,10 @@ spa_ld_select_uberblock(spa_t *spa, spa_import_type_t type)
                return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, ENXIO));
        }
 
+       if (spa->spa_load_max_txg != UINT64_MAX) {
+               (void) spa_import_progress_set_max_txg(spa_guid(spa),
+                   (u_longlong_t)spa->spa_load_max_txg);
+       }
        spa_load_note(spa, "using uberblock with txg=%llu",
            (u_longlong_t)ub->ub_txg);
 
@@ -2937,6 +3032,9 @@ spa_ld_select_uberblock(spa_t *spa, spa_import_type_t type)
                    ZPOOL_CONFIG_MMP_STATE, MMP_STATE_INACTIVE);
                fnvlist_add_uint64(spa->spa_load_info,
                    ZPOOL_CONFIG_MMP_TXG, ub->ub_txg);
+               fnvlist_add_uint16(spa->spa_load_info,
+                   ZPOOL_CONFIG_MMP_SEQ,
+                   (MMP_SEQ_VALID(ub) ? MMP_SEQ(ub) : 0));
        }
 
        /*
@@ -3353,6 +3451,16 @@ spa_ld_check_features(spa_t *spa, boolean_t *missing_feat_writep)
                        return (spa_vdev_err(rvd, VDEV_AUX_CORRUPT_DATA, EIO));
        }
 
+       /*
+        * Encryption was added before bookmark_v2, even though bookmark_v2
+        * is now a dependency. If this pool has encryption enabled without
+        * bookmark_v2, trigger an errata message.
+        */
+       if (spa_feature_is_enabled(spa, SPA_FEATURE_ENCRYPTION) &&
+           !spa_feature_is_enabled(spa, SPA_FEATURE_BOOKMARK_V2)) {
+               spa->spa_errata = ZPOOL_ERRATA_ZOL_8308_ENCRYPTION;
+       }
+
        return (0);
 }
 
@@ -3497,7 +3605,7 @@ spa_ld_get_props(spa_t *spa)
                spa_prop_find(spa, ZPOOL_PROP_MULTIHOST, &spa->spa_multihost);
                spa_prop_find(spa, ZPOOL_PROP_DEDUPDITTO,
                    &spa->spa_dedup_ditto);
-
+               spa_prop_find(spa, ZPOOL_PROP_AUTOTRIM, &spa->spa_autotrim);
                spa->spa_autoreplace = (autoreplace != 0);
        }
 
@@ -3823,6 +3931,8 @@ spa_ld_mos_init(spa_t *spa, spa_import_type_t type)
        if (error != 0)
                return (error);
 
+       spa_import_progress_add(spa);
+
        /*
         * Now that we have the vdev tree, try to open each vdev. This involves
         * opening the underlying physical device, retrieving its geometry and
@@ -4226,8 +4336,17 @@ spa_load_impl(spa_t *spa, spa_import_type_t type, char **ereport)
                 */
                spa_history_log_version(spa, "open", NULL);
 
+               spa_restart_removal(spa);
+               spa_spawn_aux_threads(spa);
+
                /*
                 * Delete any inconsistent datasets.
+                *
+                * Note:
+                * Since we may be issuing deletes for clones here,
+                * we make sure to do so after we've spawned all the
+                * auxiliary threads above (from which the livelist
+                * deletion zthr is part of).
                 */
                (void) dmu_objset_find(spa_name(spa),
                    dsl_destroy_inconsistent, NULL, DS_FIND_CHILDREN);
@@ -4237,11 +4356,14 @@ spa_load_impl(spa_t *spa, spa_import_type_t type, char **ereport)
                 */
                dsl_pool_clean_tmp_userrefs(spa->spa_dsl_pool);
 
-               spa_restart_removal(spa);
-
-               spa_spawn_aux_threads(spa);
+               spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
+               vdev_initialize_restart(spa->spa_root_vdev);
+               vdev_trim_restart(spa->spa_root_vdev);
+               vdev_autotrim_restart(spa);
+               spa_config_exit(spa, SCL_CONFIG, FTAG);
        }
 
+       spa_import_progress_remove(spa_guid(spa));
        spa_load_note(spa, "LOADED");
 
        return (0);
@@ -4302,6 +4424,7 @@ spa_load_best(spa_t *spa, spa_load_state_t state, uint64_t max_request,
                 * from previous txgs when spa_load fails.
                 */
                ASSERT(spa->spa_import_flags & ZFS_IMPORT_CHECKPOINT);
+               spa_import_progress_remove(spa_guid(spa));
                return (load_error);
        }
 
@@ -4313,6 +4436,7 @@ spa_load_best(spa_t *spa, spa_load_state_t state, uint64_t max_request,
 
        if (rewind_flags & ZPOOL_NEVER_REWIND) {
                nvlist_free(config);
+               spa_import_progress_remove(spa_guid(spa));
                return (load_error);
        }
 
@@ -4355,6 +4479,7 @@ spa_load_best(spa_t *spa, spa_load_state_t state, uint64_t max_request,
 
        if (state == SPA_LOAD_RECOVER) {
                ASSERT3P(loadinfo, ==, NULL);
+               spa_import_progress_remove(spa_guid(spa));
                return (rewind_error);
        } else {
                /* Store the rewind info as part of the initial load info */
@@ -4365,6 +4490,7 @@ spa_load_best(spa_t *spa, spa_load_state_t state, uint64_t max_request,
                fnvlist_free(spa->spa_load_info);
                spa->spa_load_info = loadinfo;
 
+               spa_import_progress_remove(spa_guid(spa));
                return (load_error);
        }
 }
@@ -5079,6 +5205,7 @@ spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props,
        spa->spa_removing_phys.sr_state = DSS_NONE;
        spa->spa_removing_phys.sr_removing_vdev = -1;
        spa->spa_removing_phys.sr_prev_indirect_vdev = -1;
+       spa->spa_indirect_vdevs_loaded = B_TRUE;
 
        /*
         * Create "The Godfather" zio to hold all async IOs
@@ -5241,6 +5368,7 @@ spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props,
        spa->spa_failmode = zpool_prop_default_numeric(ZPOOL_PROP_FAILUREMODE);
        spa->spa_autoexpand = zpool_prop_default_numeric(ZPOOL_PROP_AUTOEXPAND);
        spa->spa_multihost = zpool_prop_default_numeric(ZPOOL_PROP_MULTIHOST);
+       spa->spa_autotrim = zpool_prop_default_numeric(ZPOOL_PROP_AUTOTRIM);
 
        if (props != NULL) {
                spa_configfile_set(spa, props, B_FALSE);
@@ -5647,6 +5775,20 @@ spa_export_common(char *pool, int new_state, nvlist_t **oldconfig,
                        return (SET_ERROR(EXDEV));
                }
 
+               /*
+                * We're about to export or destroy this pool. Make sure
+                * we stop all initialization and trim activity here before
+                * we set the spa_final_txg. This will ensure that all
+                * dirty data resulting from the initialization is
+                * committed to disk before we unload the pool.
+                */
+               if (spa->spa_root_vdev != NULL) {
+                       vdev_t *rvd = spa->spa_root_vdev;
+                       vdev_initialize_stop_all(rvd, VDEV_INITIALIZE_ACTIVE);
+                       vdev_trim_stop_all(rvd, VDEV_TRIM_ACTIVE);
+                       vdev_autotrim_stop_all(spa);
+               }
+
                /*
                 * We want this to be reflected on every label,
                 * so mark them all dirty.  spa_unload() will do the
@@ -6059,9 +6201,14 @@ spa_vdev_attach(spa_t *spa, uint64_t guid, nvlist_t *nvroot, int replacing)
        /*
         * Schedule the resilver to restart in the future. We do this to
         * ensure that dmu_sync-ed blocks have been stitched into the
-        * respective datasets.
+        * respective datasets. We do not do this if resilvers have been
+        * deferred.
         */
-       dsl_resilver_restart(spa->spa_dsl_pool, dtl_max_txg);
+       if (dsl_scan_resilvering(spa_get_dsl(spa)) &&
+           spa_feature_is_enabled(spa, SPA_FEATURE_RESILVER_DEFER))
+               vdev_set_deferred_resilver(spa, newvd);
+       else
+               dsl_resilver_restart(spa->spa_dsl_pool, dtl_max_txg);
 
        if (spa->spa_bootfs)
                spa_event_notify(spa, newvd, NULL, ESC_ZFS_BOOTFS_VDEV_ATTACH);
@@ -6262,7 +6409,6 @@ spa_vdev_detach(spa_t *spa, uint64_t guid, uint64_t pguid, int replace_done)
                vdev_remove_parent(cvd);
        }
 
-
        /*
         * We don't set tvd until now because the parent we just removed
         * may have been the previous top-level vdev.
@@ -6346,6 +6492,237 @@ spa_vdev_detach(spa_t *spa, uint64_t guid, uint64_t pguid, int replace_done)
        return (error);
 }
 
+static int
+spa_vdev_initialize_impl(spa_t *spa, uint64_t guid, uint64_t cmd_type,
+    list_t *vd_list)
+{
+       ASSERT(MUTEX_HELD(&spa_namespace_lock));
+
+       spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
+
+       /* Look up vdev and ensure it's a leaf. */
+       vdev_t *vd = spa_lookup_by_guid(spa, guid, B_FALSE);
+       if (vd == NULL || vd->vdev_detached) {
+               spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
+               return (SET_ERROR(ENODEV));
+       } else if (!vd->vdev_ops->vdev_op_leaf || !vdev_is_concrete(vd)) {
+               spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
+               return (SET_ERROR(EINVAL));
+       } else if (!vdev_writeable(vd)) {
+               spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
+               return (SET_ERROR(EROFS));
+       }
+       mutex_enter(&vd->vdev_initialize_lock);
+       spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
+
+       /*
+        * When we activate an initialize action we check to see
+        * if the vdev_initialize_thread is NULL. We do this instead
+        * of using the vdev_initialize_state since there might be
+        * a previous initialization process which has completed but
+        * the thread is not exited.
+        */
+       if (cmd_type == POOL_INITIALIZE_START &&
+           (vd->vdev_initialize_thread != NULL ||
+           vd->vdev_top->vdev_removing)) {
+               mutex_exit(&vd->vdev_initialize_lock);
+               return (SET_ERROR(EBUSY));
+       } else if (cmd_type == POOL_INITIALIZE_CANCEL &&
+           (vd->vdev_initialize_state != VDEV_INITIALIZE_ACTIVE &&
+           vd->vdev_initialize_state != VDEV_INITIALIZE_SUSPENDED)) {
+               mutex_exit(&vd->vdev_initialize_lock);
+               return (SET_ERROR(ESRCH));
+       } else if (cmd_type == POOL_INITIALIZE_SUSPEND &&
+           vd->vdev_initialize_state != VDEV_INITIALIZE_ACTIVE) {
+               mutex_exit(&vd->vdev_initialize_lock);
+               return (SET_ERROR(ESRCH));
+       }
+
+       switch (cmd_type) {
+       case POOL_INITIALIZE_START:
+               vdev_initialize(vd);
+               break;
+       case POOL_INITIALIZE_CANCEL:
+               vdev_initialize_stop(vd, VDEV_INITIALIZE_CANCELED, vd_list);
+               break;
+       case POOL_INITIALIZE_SUSPEND:
+               vdev_initialize_stop(vd, VDEV_INITIALIZE_SUSPENDED, vd_list);
+               break;
+       default:
+               panic("invalid cmd_type %llu", (unsigned long long)cmd_type);
+       }
+       mutex_exit(&vd->vdev_initialize_lock);
+
+       return (0);
+}
+
+int
+spa_vdev_initialize(spa_t *spa, nvlist_t *nv, uint64_t cmd_type,
+    nvlist_t *vdev_errlist)
+{
+       int total_errors = 0;
+       list_t vd_list;
+
+       list_create(&vd_list, sizeof (vdev_t),
+           offsetof(vdev_t, vdev_initialize_node));
+
+       /*
+        * We hold the namespace lock through the whole function
+        * to prevent any changes to the pool while we're starting or
+        * stopping initialization. The config and state locks are held so that
+        * we can properly assess the vdev state before we commit to
+        * the initializing operation.
+        */
+       mutex_enter(&spa_namespace_lock);
+
+       for (nvpair_t *pair = nvlist_next_nvpair(nv, NULL);
+           pair != NULL; pair = nvlist_next_nvpair(nv, pair)) {
+               uint64_t vdev_guid = fnvpair_value_uint64(pair);
+
+               int error = spa_vdev_initialize_impl(spa, vdev_guid, cmd_type,
+                   &vd_list);
+               if (error != 0) {
+                       char guid_as_str[MAXNAMELEN];
+
+                       (void) snprintf(guid_as_str, sizeof (guid_as_str),
+                           "%llu", (unsigned long long)vdev_guid);
+                       fnvlist_add_int64(vdev_errlist, guid_as_str, error);
+                       total_errors++;
+               }
+       }
+
+       /* Wait for all initialize threads to stop. */
+       vdev_initialize_stop_wait(spa, &vd_list);
+
+       /* Sync out the initializing state */
+       txg_wait_synced(spa->spa_dsl_pool, 0);
+       mutex_exit(&spa_namespace_lock);
+
+       list_destroy(&vd_list);
+
+       return (total_errors);
+}
+
+static int
+spa_vdev_trim_impl(spa_t *spa, uint64_t guid, uint64_t cmd_type,
+    uint64_t rate, boolean_t partial, boolean_t secure, list_t *vd_list)
+{
+       ASSERT(MUTEX_HELD(&spa_namespace_lock));
+
+       spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
+
+       /* Look up vdev and ensure it's a leaf. */
+       vdev_t *vd = spa_lookup_by_guid(spa, guid, B_FALSE);
+       if (vd == NULL || vd->vdev_detached) {
+               spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
+               return (SET_ERROR(ENODEV));
+       } else if (!vd->vdev_ops->vdev_op_leaf || !vdev_is_concrete(vd)) {
+               spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
+               return (SET_ERROR(EINVAL));
+       } else if (!vdev_writeable(vd)) {
+               spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
+               return (SET_ERROR(EROFS));
+       } else if (!vd->vdev_has_trim) {
+               spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
+               return (SET_ERROR(EOPNOTSUPP));
+       } else if (secure && !vd->vdev_has_securetrim) {
+               spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
+               return (SET_ERROR(EOPNOTSUPP));
+       }
+       mutex_enter(&vd->vdev_trim_lock);
+       spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
+
+       /*
+        * When we activate a TRIM action we check to see if the
+        * vdev_trim_thread is NULL. We do this instead of using the
+        * vdev_trim_state since there might be a previous TRIM process
+        * which has completed but the thread is not exited.
+        */
+       if (cmd_type == POOL_TRIM_START &&
+           (vd->vdev_trim_thread != NULL || vd->vdev_top->vdev_removing)) {
+               mutex_exit(&vd->vdev_trim_lock);
+               return (SET_ERROR(EBUSY));
+       } else if (cmd_type == POOL_TRIM_CANCEL &&
+           (vd->vdev_trim_state != VDEV_TRIM_ACTIVE &&
+           vd->vdev_trim_state != VDEV_TRIM_SUSPENDED)) {
+               mutex_exit(&vd->vdev_trim_lock);
+               return (SET_ERROR(ESRCH));
+       } else if (cmd_type == POOL_TRIM_SUSPEND &&
+           vd->vdev_trim_state != VDEV_TRIM_ACTIVE) {
+               mutex_exit(&vd->vdev_trim_lock);
+               return (SET_ERROR(ESRCH));
+       }
+
+       switch (cmd_type) {
+       case POOL_TRIM_START:
+               vdev_trim(vd, rate, partial, secure);
+               break;
+       case POOL_TRIM_CANCEL:
+               vdev_trim_stop(vd, VDEV_TRIM_CANCELED, vd_list);
+               break;
+       case POOL_TRIM_SUSPEND:
+               vdev_trim_stop(vd, VDEV_TRIM_SUSPENDED, vd_list);
+               break;
+       default:
+               panic("invalid cmd_type %llu", (unsigned long long)cmd_type);
+       }
+       mutex_exit(&vd->vdev_trim_lock);
+
+       return (0);
+}
+
+/*
+ * Initiates a manual TRIM for the requested vdevs. This kicks off individual
+ * TRIM threads for each child vdev.  These threads pass over all of the free
+ * space in the vdev's metaslabs and issues TRIM commands for that space.
+ */
+int
+spa_vdev_trim(spa_t *spa, nvlist_t *nv, uint64_t cmd_type, uint64_t rate,
+    boolean_t partial, boolean_t secure, nvlist_t *vdev_errlist)
+{
+       int total_errors = 0;
+       list_t vd_list;
+
+       list_create(&vd_list, sizeof (vdev_t),
+           offsetof(vdev_t, vdev_trim_node));
+
+       /*
+        * We hold the namespace lock through the whole function
+        * to prevent any changes to the pool while we're starting or
+        * stopping TRIM. The config and state locks are held so that
+        * we can properly assess the vdev state before we commit to
+        * the TRIM operation.
+        */
+       mutex_enter(&spa_namespace_lock);
+
+       for (nvpair_t *pair = nvlist_next_nvpair(nv, NULL);
+           pair != NULL; pair = nvlist_next_nvpair(nv, pair)) {
+               uint64_t vdev_guid = fnvpair_value_uint64(pair);
+
+               int error = spa_vdev_trim_impl(spa, vdev_guid, cmd_type,
+                   rate, partial, secure, &vd_list);
+               if (error != 0) {
+                       char guid_as_str[MAXNAMELEN];
+
+                       (void) snprintf(guid_as_str, sizeof (guid_as_str),
+                           "%llu", (unsigned long long)vdev_guid);
+                       fnvlist_add_int64(vdev_errlist, guid_as_str, error);
+                       total_errors++;
+               }
+       }
+
+       /* Wait for all TRIM threads to stop. */
+       vdev_trim_stop_wait(spa, &vd_list);
+
+       /* Sync out the TRIM state */
+       txg_wait_synced(spa->spa_dsl_pool, 0);
+       mutex_exit(&spa_namespace_lock);
+
+       list_destroy(&vd_list);
+
+       return (total_errors);
+}
+
 /*
  * Split a set of devices from their mirrors, and create a new pool from them.
  */
@@ -6554,6 +6931,38 @@ spa_vdev_split_mirror(spa_t *spa, char *newname, nvlist_t *config,
        spa_activate(newspa, spa_mode_global);
        spa_async_suspend(newspa);
 
+       /*
+        * Temporarily stop the initializing and TRIM activity.  We set the
+        * state to ACTIVE so that we know to resume initializing or TRIM
+        * once the split has completed.
+        */
+       list_t vd_initialize_list;
+       list_create(&vd_initialize_list, sizeof (vdev_t),
+           offsetof(vdev_t, vdev_initialize_node));
+
+       list_t vd_trim_list;
+       list_create(&vd_trim_list, sizeof (vdev_t),
+           offsetof(vdev_t, vdev_trim_node));
+
+       for (c = 0; c < children; c++) {
+               if (vml[c] != NULL) {
+                       mutex_enter(&vml[c]->vdev_initialize_lock);
+                       vdev_initialize_stop(vml[c],
+                           VDEV_INITIALIZE_ACTIVE, &vd_initialize_list);
+                       mutex_exit(&vml[c]->vdev_initialize_lock);
+
+                       mutex_enter(&vml[c]->vdev_trim_lock);
+                       vdev_trim_stop(vml[c], VDEV_TRIM_ACTIVE, &vd_trim_list);
+                       mutex_exit(&vml[c]->vdev_trim_lock);
+               }
+       }
+
+       vdev_initialize_stop_wait(spa, &vd_initialize_list);
+       vdev_trim_stop_wait(spa, &vd_trim_list);
+
+       list_destroy(&vd_initialize_list);
+       list_destroy(&vd_trim_list);
+
        newspa->spa_config_source = SPA_CONFIG_SRC_SPLIT;
 
        /* create the new pool from the disks of the original pool */
@@ -6597,6 +7006,18 @@ spa_vdev_split_mirror(spa_t *spa, char *newname, nvlist_t *config,
                dmu_tx_abort(tx);
        for (c = 0; c < children; c++) {
                if (vml[c] != NULL) {
+                       vdev_t *tvd = vml[c]->vdev_top;
+
+                       /*
+                        * Need to be sure the detachable VDEV is not
+                        * on any *other* txg's DTL list to prevent it
+                        * from being accessed after it's freed.
+                        */
+                       for (int t = 0; t < TXG_SIZE; t++) {
+                               (void) txg_list_remove_this(
+                                   &tvd->vdev_dtl_list, vml[c], t);
+                       }
+
                        vdev_split(vml[c]);
                        if (error == 0)
                                spa_history_log_internal(spa, "detach", tx,
@@ -6641,6 +7062,12 @@ out:
                if (vml[c] != NULL)
                        vml[c]->vdev_offline = B_FALSE;
        }
+
+       /* restart initializing or trimming disks as necessary */
+       spa_async_request(spa, SPA_ASYNC_INITIALIZE_RESTART);
+       spa_async_request(spa, SPA_ASYNC_TRIM_RESTART);
+       spa_async_request(spa, SPA_ASYNC_AUTOTRIM_RESTART);
+
        vdev_reopen(spa->spa_root_vdev);
 
        nvlist_free(spa->spa_config_splitting);
@@ -6856,6 +7283,10 @@ spa_scan(spa_t *spa, pool_scan_func_t func)
        if (func >= POOL_SCAN_FUNCS || func == POOL_SCAN_NONE)
                return (SET_ERROR(ENOTSUP));
 
+       if (func == POOL_SCAN_RESILVER &&
+           !spa_feature_is_enabled(spa, SPA_FEATURE_RESILVER_DEFER))
+               return (SET_ERROR(ENOTSUP));
+
        /*
         * If a resilver was requested, but there is no DTL on a
         * writeable leaf device, we have nothing to do.
@@ -6933,6 +7364,7 @@ static void
 spa_async_thread(void *arg)
 {
        spa_t *spa = (spa_t *)arg;
+       dsl_pool_t *dp = spa->spa_dsl_pool;
        int tasks;
 
        ASSERT(spa->spa_sync_on);
@@ -7008,8 +7440,34 @@ spa_async_thread(void *arg)
        /*
         * Kick off a resilver.
         */
-       if (tasks & SPA_ASYNC_RESILVER)
-               dsl_resilver_restart(spa->spa_dsl_pool, 0);
+       if (tasks & SPA_ASYNC_RESILVER &&
+           (!dsl_scan_resilvering(dp) ||
+           !spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_RESILVER_DEFER)))
+               dsl_resilver_restart(dp, 0);
+
+       if (tasks & SPA_ASYNC_INITIALIZE_RESTART) {
+               mutex_enter(&spa_namespace_lock);
+               spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
+               vdev_initialize_restart(spa->spa_root_vdev);
+               spa_config_exit(spa, SCL_CONFIG, FTAG);
+               mutex_exit(&spa_namespace_lock);
+       }
+
+       if (tasks & SPA_ASYNC_TRIM_RESTART) {
+               mutex_enter(&spa_namespace_lock);
+               spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
+               vdev_trim_restart(spa->spa_root_vdev);
+               spa_config_exit(spa, SCL_CONFIG, FTAG);
+               mutex_exit(&spa_namespace_lock);
+       }
+
+       if (tasks & SPA_ASYNC_AUTOTRIM_RESTART) {
+               mutex_enter(&spa_namespace_lock);
+               spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
+               vdev_autotrim_restart(spa);
+               spa_config_exit(spa, SCL_CONFIG, FTAG);
+               mutex_exit(&spa_namespace_lock);
+       }
 
        /*
         * Let the world know that we're done.
@@ -7033,12 +7491,12 @@ spa_async_suspend(spa_t *spa)
        spa_vdev_remove_suspend(spa);
 
        zthr_t *condense_thread = spa->spa_condense_zthr;
-       if (condense_thread != NULL && zthr_isrunning(condense_thread))
-               VERIFY0(zthr_cancel(condense_thread));
+       if (condense_thread != NULL)
+               zthr_cancel(condense_thread);
 
        zthr_t *discard_thread = spa->spa_checkpoint_discard_zthr;
-       if (discard_thread != NULL && zthr_isrunning(discard_thread))
-               VERIFY0(zthr_cancel(discard_thread));
+       if (discard_thread != NULL)
+               zthr_cancel(discard_thread);
 }
 
 void
@@ -7051,11 +7509,11 @@ spa_async_resume(spa_t *spa)
        spa_restart_removal(spa);
 
        zthr_t *condense_thread = spa->spa_condense_zthr;
-       if (condense_thread != NULL && !zthr_isrunning(condense_thread))
+       if (condense_thread != NULL)
                zthr_resume(condense_thread);
 
        zthr_t *discard_thread = spa->spa_checkpoint_discard_zthr;
-       if (discard_thread != NULL && !zthr_isrunning(discard_thread))
+       if (discard_thread != NULL)
                zthr_resume(discard_thread);
 }
 
@@ -7144,6 +7602,9 @@ spa_sync_frees(spa_t *spa, bplist_t *bpl, dmu_tx_t *tx)
 static void
 spa_sync_deferred_frees(spa_t *spa, dmu_tx_t *tx)
 {
+       if (spa_sync_pass(spa) != 1)
+               return;
+
        zio_t *zio = zio_root(spa, NULL, NULL, 0);
        VERIFY3U(bpobj_iterate(&spa->spa_deferred_bpobj,
            spa_free_sync_cb, zio, tx), ==, 0);
@@ -7507,6 +7968,11 @@ spa_sync_props(void *arg, dmu_tx_t *tx)
                        case ZPOOL_PROP_FAILUREMODE:
                                spa->spa_failmode = intval;
                                break;
+                       case ZPOOL_PROP_AUTOTRIM:
+                               spa->spa_autotrim = intval;
+                               spa_async_request(spa,
+                                   SPA_ASYNC_AUTOTRIM_RESTART);
+                               break;
                        case ZPOOL_PROP_AUTOEXPAND:
                                spa->spa_autoexpand = intval;
                                if (tx->tx_txg != TXG_INITIAL)
@@ -7539,10 +8005,10 @@ spa_sync_props(void *arg, dmu_tx_t *tx)
 static void
 spa_sync_upgrades(spa_t *spa, dmu_tx_t *tx)
 {
-       dsl_pool_t *dp = spa->spa_dsl_pool;
-
-       ASSERT(spa->spa_sync_pass == 1);
+       if (spa_sync_pass(spa) != 1)
+               return;
 
+       dsl_pool_t *dp = spa->spa_dsl_pool;
        rrw_enter(&dp->dp_config_rwlock, RW_WRITER, FTAG);
 
        if (spa->spa_ubsync.ub_version < SPA_VERSION_ORIGIN &&
@@ -7614,14 +8080,15 @@ vdev_indirect_state_sync_verify(vdev_t *vd)
                ASSERT(vib != NULL);
        }
 
-       if (vdev_obsolete_sm_object(vd) != 0) {
+       uint64_t obsolete_sm_object = 0;
+       ASSERT0(vdev_obsolete_sm_object(vd, &obsolete_sm_object));
+       if (obsolete_sm_object != 0) {
                ASSERT(vd->vdev_obsolete_sm != NULL);
                ASSERT(vd->vdev_removing ||
                    vd->vdev_ops == &vdev_indirect_ops);
                ASSERT(vdev_indirect_mapping_num_entries(vim) > 0);
                ASSERT(vdev_indirect_mapping_bytes_mapped(vim) > 0);
-
-               ASSERT3U(vdev_obsolete_sm_object(vd), ==,
+               ASSERT3U(obsolete_sm_object, ==,
                    space_map_object(vd->vdev_obsolete_sm));
                ASSERT3U(vdev_indirect_mapping_bytes_mapped(vim), >=,
                    space_map_allocated(vd->vdev_obsolete_sm));
@@ -7637,117 +8104,31 @@ vdev_indirect_state_sync_verify(vdev_t *vd)
 }
 
 /*
- * Sync the specified transaction group.  New blocks may be dirtied as
- * part of the process, so we iterate until it converges.
+ * Set the top-level vdev's max queue depth. Evaluate each top-level's
+ * async write queue depth in case it changed. The max queue depth will
+ * not change in the middle of syncing out this txg.
  */
-void
-spa_sync(spa_t *spa, uint64_t txg)
+static void
+spa_sync_adjust_vdev_max_queue_depth(spa_t *spa)
 {
-       dsl_pool_t *dp = spa->spa_dsl_pool;
-       objset_t *mos = spa->spa_meta_objset;
-       bplist_t *free_bpl = &spa->spa_free_bplist[txg & TXG_MASK];
-       metaslab_class_t *normal = spa_normal_class(spa);
-       metaslab_class_t *special = spa_special_class(spa);
-       metaslab_class_t *dedup = spa_dedup_class(spa);
+       ASSERT(spa_writeable(spa));
+
        vdev_t *rvd = spa->spa_root_vdev;
-       vdev_t *vd;
-       dmu_tx_t *tx;
-       int error;
        uint32_t max_queue_depth = zfs_vdev_async_write_max_active *
            zfs_vdev_queue_depth_pct / 100;
+       metaslab_class_t *normal = spa_normal_class(spa);
+       metaslab_class_t *special = spa_special_class(spa);
+       metaslab_class_t *dedup = spa_dedup_class(spa);
 
-       VERIFY(spa_writeable(spa));
-
-       /*
-        * Wait for i/os issued in open context that need to complete
-        * before this txg syncs.
-        */
-       VERIFY0(zio_wait(spa->spa_txg_zio[txg & TXG_MASK]));
-       spa->spa_txg_zio[txg & TXG_MASK] = zio_root(spa, NULL, NULL, 0);
-
-       /*
-        * Lock out configuration changes.
-        */
-       spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
-
-       spa->spa_syncing_txg = txg;
-       spa->spa_sync_pass = 0;
-
-       for (int i = 0; i < spa->spa_alloc_count; i++) {
-               mutex_enter(&spa->spa_alloc_locks[i]);
-               VERIFY0(avl_numnodes(&spa->spa_alloc_trees[i]));
-               mutex_exit(&spa->spa_alloc_locks[i]);
-       }
-
-       /*
-        * If there are any pending vdev state changes, convert them
-        * into config changes that go out with this transaction group.
-        */
-       spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
-       while (list_head(&spa->spa_state_dirty_list) != NULL) {
-               /*
-                * We need the write lock here because, for aux vdevs,
-                * calling vdev_config_dirty() modifies sav_config.
-                * This is ugly and will become unnecessary when we
-                * eliminate the aux vdev wart by integrating all vdevs
-                * into the root vdev tree.
-                */
-               spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
-               spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_WRITER);
-               while ((vd = list_head(&spa->spa_state_dirty_list)) != NULL) {
-                       vdev_state_clean(vd);
-                       vdev_config_dirty(vd);
-               }
-               spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
-               spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
-       }
-       spa_config_exit(spa, SCL_STATE, FTAG);
-
-       tx = dmu_tx_create_assigned(dp, txg);
-
-       spa->spa_sync_starttime = gethrtime();
-       taskq_cancel_id(system_delay_taskq, spa->spa_deadman_tqid);
-       spa->spa_deadman_tqid = taskq_dispatch_delay(system_delay_taskq,
-           spa_deadman, spa, TQ_SLEEP, ddi_get_lbolt() +
-           NSEC_TO_TICK(spa->spa_deadman_synctime));
-
-       /*
-        * If we are upgrading to SPA_VERSION_RAIDZ_DEFLATE this txg,
-        * set spa_deflate if we have no raid-z vdevs.
-        */
-       if (spa->spa_ubsync.ub_version < SPA_VERSION_RAIDZ_DEFLATE &&
-           spa->spa_uberblock.ub_version >= SPA_VERSION_RAIDZ_DEFLATE) {
-               int i;
-
-               for (i = 0; i < rvd->vdev_children; i++) {
-                       vd = rvd->vdev_child[i];
-                       if (vd->vdev_deflate_ratio != SPA_MINBLOCKSIZE)
-                               break;
-               }
-               if (i == rvd->vdev_children) {
-                       spa->spa_deflate = TRUE;
-                       VERIFY(0 == zap_add(spa->spa_meta_objset,
-                           DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
-                           sizeof (uint64_t), 1, &spa->spa_deflate, tx));
-               }
-       }
-
-       /*
-        * Set the top-level vdev's max queue depth. Evaluate each
-        * top-level's async write queue depth in case it changed.
-        * The max queue depth will not change in the middle of syncing
-        * out this txg.
-        */
        uint64_t slots_per_allocator = 0;
        for (int c = 0; c < rvd->vdev_children; c++) {
                vdev_t *tvd = rvd->vdev_child[c];
-               metaslab_group_t *mg = tvd->vdev_mg;
-               metaslab_class_t *mc;
 
+               metaslab_group_t *mg = tvd->vdev_mg;
                if (mg == NULL || !metaslab_group_initialized(mg))
                        continue;
 
-               mc = mg->mg_class;
+               metaslab_class_t *mc = mg->mg_class;
                if (mc != normal && mc != special && mc != dedup)
                        continue;
 
@@ -7779,7 +8160,14 @@ spa_sync(spa_t *spa, uint64_t txg)
        normal->mc_alloc_throttle_enabled = zio_dva_throttle_enabled;
        special->mc_alloc_throttle_enabled = zio_dva_throttle_enabled;
        dedup->mc_alloc_throttle_enabled = zio_dva_throttle_enabled;
+}
+
+static void
+spa_sync_condense_indirect(spa_t *spa, dmu_tx_t *tx)
+{
+       ASSERT(spa_writeable(spa));
 
+       vdev_t *rvd = spa->spa_root_vdev;
        for (int c = 0; c < rvd->vdev_children; c++) {
                vdev_t *vd = rvd->vdev_child[c];
                vdev_indirect_state_sync_verify(vd);
@@ -7789,10 +8177,16 @@ spa_sync(spa_t *spa, uint64_t txg)
                        break;
                }
        }
+}
+
+static void
+spa_sync_iterate_to_convergence(spa_t *spa, dmu_tx_t *tx)
+{
+       objset_t *mos = spa->spa_meta_objset;
+       dsl_pool_t *dp = spa->spa_dsl_pool;
+       uint64_t txg = tx->tx_txg;
+       bplist_t *free_bpl = &spa->spa_free_bplist[txg & TXG_MASK];
 
-       /*
-        * Iterate to convergence.
-        */
        do {
                int pass = ++spa->spa_sync_pass;
 
@@ -7818,81 +8212,60 @@ spa_sync(spa_t *spa, uint64_t txg)
 
                ddt_sync(spa, txg);
                dsl_scan_sync(dp, tx);
+               svr_sync(spa, tx);
+               spa_sync_upgrades(spa, tx);
 
-               if (spa->spa_vdev_removal != NULL)
-                       svr_sync(spa, tx);
-
+               vdev_t *vd = NULL;
                while ((vd = txg_list_remove(&spa->spa_vdev_txg_list, txg))
                    != NULL)
                        vdev_sync(vd, txg);
 
-               if (pass == 1) {
-                       spa_sync_upgrades(spa, tx);
-                       ASSERT3U(txg, >=,
-                           spa->spa_uberblock.ub_rootbp.blk_birth);
+               /*
+                * Note: We need to check if the MOS is dirty because we could
+                * have marked the MOS dirty without updating the uberblock
+                * (e.g. if we have sync tasks but no dirty user data). We need
+                * to check the uberblock's rootbp because it is updated if we
+                * have synced out dirty data (though in this case the MOS will
+                * most likely also be dirty due to second order effects, we
+                * don't want to rely on that here).
+                */
+               if (pass == 1 &&
+                   spa->spa_uberblock.ub_rootbp.blk_birth < txg &&
+                   !dmu_objset_is_dirty(mos, txg)) {
                        /*
-                        * Note: We need to check if the MOS is dirty
-                        * because we could have marked the MOS dirty
-                        * without updating the uberblock (e.g. if we
-                        * have sync tasks but no dirty user data).  We
-                        * need to check the uberblock's rootbp because
-                        * it is updated if we have synced out dirty
-                        * data (though in this case the MOS will most
-                        * likely also be dirty due to second order
-                        * effects, we don't want to rely on that here).
+                        * Nothing changed on the first pass, therefore this
+                        * TXG is a no-op. Avoid syncing deferred frees, so
+                        * that we can keep this TXG as a no-op.
                         */
-                       if (spa->spa_uberblock.ub_rootbp.blk_birth < txg &&
-                           !dmu_objset_is_dirty(mos, txg)) {
-                               /*
-                                * Nothing changed on the first pass,
-                                * therefore this TXG is a no-op.  Avoid
-                                * syncing deferred frees, so that we
-                                * can keep this TXG as a no-op.
-                                */
-                               ASSERT(txg_list_empty(&dp->dp_dirty_datasets,
-                                   txg));
-                               ASSERT(txg_list_empty(&dp->dp_dirty_dirs, txg));
-                               ASSERT(txg_list_empty(&dp->dp_sync_tasks, txg));
-                               ASSERT(txg_list_empty(&dp->dp_early_sync_tasks,
-                                   txg));
-                               break;
-                       }
-                       spa_sync_deferred_frees(spa, tx);
+                       ASSERT(txg_list_empty(&dp->dp_dirty_datasets, txg));
+                       ASSERT(txg_list_empty(&dp->dp_dirty_dirs, txg));
+                       ASSERT(txg_list_empty(&dp->dp_sync_tasks, txg));
+                       ASSERT(txg_list_empty(&dp->dp_early_sync_tasks, txg));
+                       break;
                }
 
+               spa_sync_deferred_frees(spa, tx);
        } while (dmu_objset_is_dirty(mos, txg));
+}
 
-#ifdef ZFS_DEBUG
-       if (!list_is_empty(&spa->spa_config_dirty_list)) {
-               /*
-                * Make sure that the number of ZAPs for all the vdevs matches
-                * the number of ZAPs in the per-vdev ZAP list. This only gets
-                * called if the config is dirty; otherwise there may be
-                * outstanding AVZ operations that weren't completed in
-                * spa_sync_config_object.
-                */
-               uint64_t all_vdev_zap_entry_count;
-               ASSERT0(zap_count(spa->spa_meta_objset,
-                   spa->spa_all_vdev_zaps, &all_vdev_zap_entry_count));
-               ASSERT3U(vdev_count_verify_zaps(spa->spa_root_vdev), ==,
-                   all_vdev_zap_entry_count);
-       }
-#endif
-
-       if (spa->spa_vdev_removal != NULL) {
-               ASSERT0(spa->spa_vdev_removal->svr_bytes_done[txg & TXG_MASK]);
-       }
+/*
+ * Rewrite the vdev configuration (which includes the uberblock) to
+ * commit the transaction group.
+ *
+ * If there are no dirty vdevs, we sync the uberblock to a few random
+ * top-level vdevs that are known to be visible in the config cache
+ * (see spa_vdev_add() for a complete description). If there *are* dirty
+ * vdevs, sync the uberblock to all vdevs.
+ */
+static void
+spa_sync_rewrite_vdev_config(spa_t *spa, dmu_tx_t *tx)
+{
+       vdev_t *rvd = spa->spa_root_vdev;
+       uint64_t txg = tx->tx_txg;
 
-       /*
-        * Rewrite the vdev configuration (which includes the uberblock)
-        * to commit the transaction group.
-        *
-        * If there are no dirty vdevs, we sync the uberblock to a few
-        * random top-level vdevs that are known to be visible in the
-        * config cache (see spa_vdev_add() for a complete description).
-        * If there *are* dirty vdevs, sync the uberblock to all vdevs.
-        */
        for (;;) {
+               int error = 0;
+
                /*
                 * We hold SCL_STATE to prevent vdev open/close/etc.
                 * while we're attempting to write the vdev labels.
@@ -7906,13 +8279,15 @@ spa_sync(spa_t *spa, uint64_t txg)
                        int c0 = spa_get_random(children);
 
                        for (int c = 0; c < children; c++) {
-                               vd = rvd->vdev_child[(c0 + c) % children];
+                               vdev_t *vd =
+                                   rvd->vdev_child[(c0 + c) % children];
 
                                /* Stop when revisiting the first vdev */
                                if (c > 0 && svd[0] == vd)
                                        break;
 
-                               if (vd->vdev_ms_array == 0 || vd->vdev_islog ||
+                               if (vd->vdev_ms_array == 0 ||
+                                   vd->vdev_islog ||
                                    !vdev_is_concrete(vd))
                                        continue;
 
@@ -7936,6 +8311,124 @@ spa_sync(spa_t *spa, uint64_t txg)
                zio_suspend(spa, NULL, ZIO_SUSPEND_IOERR);
                zio_resume_wait(spa);
        }
+}
+
+/*
+ * Sync the specified transaction group.  New blocks may be dirtied as
+ * part of the process, so we iterate until it converges.
+ */
+void
+spa_sync(spa_t *spa, uint64_t txg)
+{
+       vdev_t *vd = NULL;
+
+       VERIFY(spa_writeable(spa));
+
+       /*
+        * Wait for i/os issued in open context that need to complete
+        * before this txg syncs.
+        */
+       (void) zio_wait(spa->spa_txg_zio[txg & TXG_MASK]);
+       spa->spa_txg_zio[txg & TXG_MASK] = zio_root(spa, NULL, NULL,
+           ZIO_FLAG_CANFAIL);
+
+       /*
+        * Lock out configuration changes.
+        */
+       spa_config_enter(spa, SCL_CONFIG, FTAG, RW_READER);
+
+       spa->spa_syncing_txg = txg;
+       spa->spa_sync_pass = 0;
+
+       for (int i = 0; i < spa->spa_alloc_count; i++) {
+               mutex_enter(&spa->spa_alloc_locks[i]);
+               VERIFY0(avl_numnodes(&spa->spa_alloc_trees[i]));
+               mutex_exit(&spa->spa_alloc_locks[i]);
+       }
+
+       /*
+        * If there are any pending vdev state changes, convert them
+        * into config changes that go out with this transaction group.
+        */
+       spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
+       while (list_head(&spa->spa_state_dirty_list) != NULL) {
+               /*
+                * We need the write lock here because, for aux vdevs,
+                * calling vdev_config_dirty() modifies sav_config.
+                * This is ugly and will become unnecessary when we
+                * eliminate the aux vdev wart by integrating all vdevs
+                * into the root vdev tree.
+                */
+               spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
+               spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_WRITER);
+               while ((vd = list_head(&spa->spa_state_dirty_list)) != NULL) {
+                       vdev_state_clean(vd);
+                       vdev_config_dirty(vd);
+               }
+               spa_config_exit(spa, SCL_CONFIG | SCL_STATE, FTAG);
+               spa_config_enter(spa, SCL_CONFIG | SCL_STATE, FTAG, RW_READER);
+       }
+       spa_config_exit(spa, SCL_STATE, FTAG);
+
+       dsl_pool_t *dp = spa->spa_dsl_pool;
+       dmu_tx_t *tx = dmu_tx_create_assigned(dp, txg);
+
+       spa->spa_sync_starttime = gethrtime();
+       taskq_cancel_id(system_delay_taskq, spa->spa_deadman_tqid);
+       spa->spa_deadman_tqid = taskq_dispatch_delay(system_delay_taskq,
+           spa_deadman, spa, TQ_SLEEP, ddi_get_lbolt() +
+           NSEC_TO_TICK(spa->spa_deadman_synctime));
+
+       /*
+        * If we are upgrading to SPA_VERSION_RAIDZ_DEFLATE this txg,
+        * set spa_deflate if we have no raid-z vdevs.
+        */
+       if (spa->spa_ubsync.ub_version < SPA_VERSION_RAIDZ_DEFLATE &&
+           spa->spa_uberblock.ub_version >= SPA_VERSION_RAIDZ_DEFLATE) {
+               vdev_t *rvd = spa->spa_root_vdev;
+
+               int i;
+               for (i = 0; i < rvd->vdev_children; i++) {
+                       vd = rvd->vdev_child[i];
+                       if (vd->vdev_deflate_ratio != SPA_MINBLOCKSIZE)
+                               break;
+               }
+               if (i == rvd->vdev_children) {
+                       spa->spa_deflate = TRUE;
+                       VERIFY0(zap_add(spa->spa_meta_objset,
+                           DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
+                           sizeof (uint64_t), 1, &spa->spa_deflate, tx));
+               }
+       }
+
+       spa_sync_adjust_vdev_max_queue_depth(spa);
+
+       spa_sync_condense_indirect(spa, tx);
+
+       spa_sync_iterate_to_convergence(spa, tx);
+
+#ifdef ZFS_DEBUG
+       if (!list_is_empty(&spa->spa_config_dirty_list)) {
+       /*
+        * Make sure that the number of ZAPs for all the vdevs matches
+        * the number of ZAPs in the per-vdev ZAP list. This only gets
+        * called if the config is dirty; otherwise there may be
+        * outstanding AVZ operations that weren't completed in
+        * spa_sync_config_object.
+        */
+               uint64_t all_vdev_zap_entry_count;
+               ASSERT0(zap_count(spa->spa_meta_objset,
+                   spa->spa_all_vdev_zaps, &all_vdev_zap_entry_count));
+               ASSERT3U(vdev_count_verify_zaps(spa->spa_root_vdev), ==,
+                   all_vdev_zap_entry_count);
+       }
+#endif
+
+       if (spa->spa_vdev_removal != NULL) {
+               ASSERT0(spa->spa_vdev_removal->svr_bytes_done[txg & TXG_MASK]);
+       }
+
+       spa_sync_rewrite_vdev_config(spa, tx);
        dmu_tx_commit(tx);
 
        taskq_cancel_id(system_delay_taskq, spa->spa_deadman_tqid);
@@ -7968,7 +8461,8 @@ spa_sync(spa_t *spa, uint64_t txg)
        /*
         * Update usable space statistics.
         */
-       while ((vd = txg_list_remove(&spa->spa_vdev_txg_list, TXG_CLEAN(txg))))
+       while ((vd = txg_list_remove(&spa->spa_vdev_txg_list, TXG_CLEAN(txg)))
+           != NULL)
                vdev_sync_done(vd, txg);
 
        spa_update_dspace(spa);