Simplify log vdev removal code

Get rid of the majority metaslab metadata when removing log vdevs
in spa_vdev_remove_log() with a call to metaslab_fini() instead
of duplicating a lot of that in vdev_remove_empty_log().

Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes #8347

diff --git a/module/zfs/vdev.c b/module/zfs/vdev.c
index def98ad136f10a2e4c6949db85ae056c4036f2ed..7add0d6e6cb1c778d2bc6a708b7a2938759736f2 100644 (file)
--- a/module/zfs/vdev.c
+++ b/module/zfs/vdev.c
@@ -3179,47 +3179,6 @@ vdev_remove_empty_log(vdev_t *vd, uint64_t txg)
        ASSERT(vd == vd->vdev_top);
        ASSERT3U(txg, ==, spa_syncing_txg(spa));
 
-       if (vd->vdev_ms != NULL) {
-               metaslab_group_t *mg = vd->vdev_mg;
-
-               metaslab_group_histogram_verify(mg);
-               metaslab_class_histogram_verify(mg->mg_class);
-
-               for (int m = 0; m < vd->vdev_ms_count; m++) {
-                       metaslab_t *msp = vd->vdev_ms[m];
-
-                       if (msp == NULL || msp->ms_sm == NULL)
-                               continue;
-
-                       mutex_enter(&msp->ms_lock);
-                       /*
-                        * If the metaslab was not loaded when the vdev
-                        * was removed then the histogram accounting may
-                        * not be accurate. Update the histogram information
-                        * here so that we ensure that the metaslab group
-                        * and metaslab class are up-to-date.
-                        */
-                       metaslab_group_histogram_remove(mg, msp);
-
-                       VERIFY0(space_map_allocated(msp->ms_sm));
-                       space_map_close(msp->ms_sm);
-                       msp->ms_sm = NULL;
-                       mutex_exit(&msp->ms_lock);
-               }
-
-               if (vd->vdev_checkpoint_sm != NULL) {
-                       ASSERT(spa_has_checkpoint(spa));
-                       space_map_close(vd->vdev_checkpoint_sm);
-                       vd->vdev_checkpoint_sm = NULL;
-               }
-
-               metaslab_group_histogram_verify(mg);
-               metaslab_class_histogram_verify(mg->mg_class);
-
-               for (int i = 0; i < RANGE_TREE_HISTOGRAM_SIZE; i++)
-                       ASSERT0(mg->mg_histogram[i]);
-       }
-
        dmu_tx_t *tx = dmu_tx_create_assigned(spa_get_dsl(spa), txg);
 
        vdev_destroy_spacemaps(vd, tx);
@@ -3253,17 +3212,14 @@ vdev_sync(vdev_t *vd, uint64_t txg)
        spa_t *spa = vd->vdev_spa;
        vdev_t *lvd;
        metaslab_t *msp;
-       dmu_tx_t *tx;
 
+       ASSERT3U(txg, ==, spa->spa_syncing_txg);
+       dmu_tx_t *tx = dmu_tx_create_assigned(spa->spa_dsl_pool, txg);
        if (range_tree_space(vd->vdev_obsolete_segments) > 0) {
-               dmu_tx_t *tx;
-
                ASSERT(vd->vdev_removing ||
                    vd->vdev_ops == &vdev_indirect_ops);
 
-               tx = dmu_tx_create_assigned(spa->spa_dsl_pool, txg);
                vdev_indirect_sync_obsolete(vd, tx);
-               dmu_tx_commit(tx);
 
                /*
                 * If the vdev is indirect, it can't have dirty
@@ -3272,6 +3228,7 @@ vdev_sync(vdev_t *vd, uint64_t txg)
                if (vd->vdev_ops == &vdev_indirect_ops) {
                        ASSERT(txg_list_empty(&vd->vdev_ms_list, txg));
                        ASSERT(txg_list_empty(&vd->vdev_dtl_list, txg));
+                       dmu_tx_commit(tx);
                        return;
                }
        }
@@ -3282,12 +3239,10 @@ vdev_sync(vdev_t *vd, uint64_t txg)
            !vd->vdev_removing) {
                ASSERT(vd == vd->vdev_top);
                ASSERT0(vd->vdev_indirect_config.vic_mapping_object);
-               tx = dmu_tx_create_assigned(spa->spa_dsl_pool, txg);
                vd->vdev_ms_array = dmu_object_alloc(spa->spa_meta_objset,
                    DMU_OT_OBJECT_ARRAY, 0, DMU_OT_NONE, 0, tx);
                ASSERT(vd->vdev_ms_array != 0);
                vdev_config_dirty(vd);
-               dmu_tx_commit(tx);
        }
 
        while ((msp = txg_list_remove(&vd->vdev_ms_list, txg)) != NULL) {
@@ -3306,6 +3261,7 @@ vdev_sync(vdev_t *vd, uint64_t txg)
                vdev_remove_empty_log(vd, txg);
 
        (void) txg_list_add(&spa->spa_vdev_txg_list, vd, TXG_CLEAN(txg));
+       dmu_tx_commit(tx);
 }
 
 uint64_t

diff --git a/module/zfs/vdev_removal.c b/module/zfs/vdev_removal.c
index 8d89007872f8a912b1299621ffd4dac60a476d5c..70620499756c871d3a87f0766e248209564364f7 100644 (file)
--- a/module/zfs/vdev_removal.c
+++ b/module/zfs/vdev_removal.c
@@ -1858,6 +1858,7 @@ spa_vdev_remove_log(vdev_t *vd, uint64_t *txg)
 
        ASSERT(vd->vdev_islog);
        ASSERT(vd == vd->vdev_top);
+       ASSERT(MUTEX_HELD(&spa_namespace_lock));
 
        /*
         * Stop allocating from this vdev.
@@ -1872,15 +1873,14 @@ spa_vdev_remove_log(vdev_t *vd, uint64_t *txg)
            *txg + TXG_CONCURRENT_STATES + TXG_DEFER_SIZE, 0, FTAG);
 
        /*
-        * Evacuate the device.  We don't hold the config lock as writer
-        * since we need to do I/O but we do keep the
+        * Evacuate the device.  We don't hold the config lock as
+        * writer since we need to do I/O but we do keep the
         * spa_namespace_lock held.  Once this completes the device
         * should no longer have any blocks allocated on it.
         */
-       if (vd->vdev_islog) {
-               if (vd->vdev_stat.vs_alloc != 0)
-                       error = spa_reset_logs(spa);
-       }
+       ASSERT(MUTEX_HELD(&spa_namespace_lock));
+       if (vd->vdev_stat.vs_alloc != 0)
+               error = spa_reset_logs(spa);
 
        *txg = spa_vdev_config_enter(spa);
 
@@ -1899,6 +1899,8 @@ spa_vdev_remove_log(vdev_t *vd, uint64_t *txg)
        vdev_dirty_leaves(vd, VDD_DTL, *txg);
        vdev_config_dirty(vd);
 
+       vdev_metaslab_fini(vd);
+
        spa_vdev_config_exit(spa, NULL, *txg, 0, FTAG);
 
        /* Stop initializing */
@@ -1923,6 +1925,8 @@ spa_vdev_remove_log(vdev_t *vd, uint64_t *txg)
        if (list_link_active(&vd->vdev_config_dirty_node))
                vdev_config_clean(vd);
 
+       ASSERT0(vd->vdev_stat.vs_alloc);
+
        /*
         * Clean up the vdev namespace.
         */