Fix available space accounting for special/dedup (#18222)

Currently, spa_dspace (base to calculate dataset AVAIL) only includes
the normal allocation class capacity, but dd_used_bytes tracks space
allocated across all classes.  Since we don't want to report free
space of other classes as available (we can't promise new allocations
will be able to use it), report only allocated space, similar to how
we report space saved by dedup and block cloning.

Since we need deflated space here, make allocation classes track
deflated allocated space also.  While here, make mc_deferred also
deflated, matching its use contexts.  Also while there, use
atomic_load() to read the allocation class stats.

Reviewed-by: Rob Norris <robn@despairlabs.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <alexander.motin@TrueNAS.com>
Closes #18190
Closes #18222

module/zfs/metaslab.c

@@ -457,7 +457,9 @@ metaslab_class_destroy(metaslab_class_t *mc)
 	spa_t *spa = mc->mc_spa;
 
 	ASSERT0(mc->mc_alloc);
+	ASSERT0(mc->mc_dalloc);
 	ASSERT0(mc->mc_deferred);
+	ASSERT0(mc->mc_ddeferred);
 	ASSERT0(mc->mc_space);
 	ASSERT0(mc->mc_dspace);
 
@@ -573,8 +575,10 @@ metaslab_class_balance(metaslab_class_t *mc, boolean_t onsync)
 		 * relative to average.  Bigger vdevs should get more to
 		 * fill up at the same time as smaller ones.
 		 */
-		if (mc->mc_space > 0 && vs->vs_space > 0) {
-			ratio = vs->vs_space / (mc->mc_space / (mc->mc_groups *
+		uint64_t mc_space = atomic_load_64(&mc->mc_space);
+		uint64_t vs_space = atomic_load_64(&vs->vs_space);
+		if (mc_space > 0 && vs_space > 0) {
+			ratio = vs_space / (mc_space / (mc->mc_groups *
 			    256) + 1);
 			mg_aliquot = mg_aliquot * ratio / 256;
 		}
@@ -595,18 +599,20 @@ metaslab_class_balance(metaslab_class_t *mc, boolean_t onsync)
 		 * queue depth, stronger enforcing the free space balance.
 		 */
 		if (metaslab_bias_enabled &&
-		    mc->mc_space > 0 && vs->vs_space > 0) {
-			uint64_t vs_free = vs->vs_space > vs->vs_alloc ?
-			    vs->vs_space - vs->vs_alloc : 0;
-			uint64_t mc_free = mc->mc_space > mc->mc_alloc ?
-			    mc->mc_space - mc->mc_alloc : 0;
+		    mc_space > 0 && vs_space > 0) {
+			uint64_t mc_alloc = atomic_load_64(&mc->mc_alloc);
+			uint64_t vs_alloc = atomic_load_64(&vs->vs_alloc);
+			uint64_t vs_free = vs_space > vs_alloc ?
+			    vs_space - vs_alloc : 0;
+			uint64_t mc_free = mc_space > mc_alloc ?
+			    mc_space - mc_alloc : 0;
 			/*
 			 * vs_fr is 16 bit fixed-point free space fraction.
 			 * mc_fr is 8 bit fixed-point free space fraction.
 			 * ratio as their quotient is 8 bit fixed-point.
 			 */
-			uint_t vs_fr = vs_free / (vs->vs_space / 65536 + 1);
-			uint_t mc_fr = mc_free / (mc->mc_space / 256 + 1);
+			uint_t vs_fr = vs_free / (vs_space / 65536 + 1);
+			uint_t mc_fr = mc_free / (mc_space / 256 + 1);
 			ratio = vs_fr / (mc_fr + 1);
 			mg->mg_aliquot = mg_aliquot * ratio / 256;
 			/* From 2.5x at 25% full to 1x at 75%. */
@@ -693,10 +699,13 @@ rotate:
 
 static void
 metaslab_class_space_update(metaslab_class_t *mc, int64_t alloc_delta,
-    int64_t defer_delta, int64_t space_delta, int64_t dspace_delta)
+    int64_t dalloc_delta, int64_t deferred_delta, int64_t ddeferred_delta,
+    int64_t space_delta, int64_t dspace_delta)
 {
 	atomic_add_64(&mc->mc_alloc, alloc_delta);
-	atomic_add_64(&mc->mc_deferred, defer_delta);
+	atomic_add_64(&mc->mc_dalloc, dalloc_delta);
+	atomic_add_64(&mc->mc_deferred, deferred_delta);
+	atomic_add_64(&mc->mc_ddeferred, ddeferred_delta);
 	atomic_add_64(&mc->mc_space, space_delta);
 	atomic_add_64(&mc->mc_dspace, dspace_delta);
 }
@@ -710,25 +719,34 @@ metaslab_class_get_name(metaslab_class_t *mc)
 uint64_t
 metaslab_class_get_alloc(metaslab_class_t *mc)
 {
-	return (mc->mc_alloc);
+	return (atomic_load_64(&mc->mc_alloc));
+}
+
+uint64_t
+metaslab_class_get_dalloc(metaslab_class_t *mc)
+{
+	return (spa_deflate(mc->mc_spa) ? atomic_load_64(&mc->mc_dalloc) :
+	    atomic_load_64(&mc->mc_alloc));
 }
 
 uint64_t
 metaslab_class_get_deferred(metaslab_class_t *mc)
 {
-	return (mc->mc_deferred);
+	return (spa_deflate(mc->mc_spa) ? atomic_load_64(&mc->mc_ddeferred) :
+	    atomic_load_64(&mc->mc_deferred));
 }
 
 uint64_t
 metaslab_class_get_space(metaslab_class_t *mc)
 {
-	return (mc->mc_space);
+	return (atomic_load_64(&mc->mc_space));
 }
 
 uint64_t
 metaslab_class_get_dspace(metaslab_class_t *mc)
 {
-	return (spa_deflate(mc->mc_spa) ? mc->mc_dspace : mc->mc_space);
+	return (spa_deflate(mc->mc_spa) ? atomic_load_64(&mc->mc_dspace) :
+	    atomic_load_64(&mc->mc_space));
 }
 
 void
@@ -2841,16 +2859,21 @@ metaslab_set_selected_txg(metaslab_t *msp, uint64_t txg)
 }
 
 void
-metaslab_space_update(vdev_t *vd, metaslab_class_t *mc, int64_t alloc_delta,
+metaslab_space_update(metaslab_group_t *mg, int64_t alloc_delta,
     int64_t defer_delta, int64_t space_delta)
 {
+	vdev_t *vd = mg->mg_vd;
+	int64_t dalloc_delta = vdev_deflated_space(vd, alloc_delta);
+	int64_t ddefer_delta = vdev_deflated_space(vd, defer_delta);
+	int64_t dspace_delta = vdev_deflated_space(vd, space_delta);
+
 	vdev_space_update(vd, alloc_delta, defer_delta, space_delta);
 
 	ASSERT3P(vd->vdev_spa->spa_root_vdev, ==, vd->vdev_parent);
 	ASSERT(vd->vdev_ms_count != 0);
 
-	metaslab_class_space_update(mc, alloc_delta, defer_delta, space_delta,
-	    vdev_deflated_space(vd, space_delta));
+	metaslab_class_space_update(mg->mg_class, alloc_delta, dalloc_delta,
+	    defer_delta, ddefer_delta, space_delta, dspace_delta);
 }
 
 int
@@ -2962,8 +2985,7 @@ metaslab_init(metaslab_group_t *mg, uint64_t id, uint64_t object,
 	 */
 	if (txg <= TXG_INITIAL) {
 		metaslab_sync_done(ms, 0);
-		metaslab_space_update(vd, mg->mg_class,
-		    metaslab_allocated_space(ms), 0, 0);
+		metaslab_space_update(mg, metaslab_allocated_space(ms), 0, 0);
 	}
 
 	if (txg != 0) {
@@ -3025,9 +3047,8 @@ metaslab_fini(metaslab_t *msp)
 	 * subtracted.
 	 */
 	if (!msp->ms_new) {
-		metaslab_space_update(vd, mg->mg_class,
-		    -metaslab_allocated_space(msp), 0, -msp->ms_size);
-
+		metaslab_space_update(mg, -metaslab_allocated_space(msp), 0,
+		    -msp->ms_size);
 	}
 	space_map_close(msp->ms_sm);
 	msp->ms_sm = NULL;
@@ -4537,7 +4558,7 @@ metaslab_sync_done(metaslab_t *msp, uint64_t txg)
 
 	if (msp->ms_new) {
 		/* this is a new metaslab, add its capacity to the vdev */
-		metaslab_space_update(vd, mg->mg_class, 0, 0, msp->ms_size);
+		metaslab_space_update(mg, 0, 0, msp->ms_size);
 
 		/* there should be no allocations nor frees at this point */
 		VERIFY0(msp->ms_allocated_this_txg);
@@ -4566,8 +4587,7 @@ metaslab_sync_done(metaslab_t *msp, uint64_t txg)
 	} else {
 		defer_delta -= zfs_range_tree_space(*defer_tree);
 	}
-	metaslab_space_update(vd, mg->mg_class, alloc_delta + defer_delta,
-	    defer_delta, 0);
+	metaslab_space_update(mg, alloc_delta + defer_delta, defer_delta, 0);
 
 	if (spa_syncing_log_sm(spa) == NULL) {
 		/*

module/zfs/spa.c

@@ -7120,6 +7120,7 @@ spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props,
 	spa->spa_removing_phys.sr_removing_vdev = -1;
 	spa->spa_removing_phys.sr_prev_indirect_vdev = -1;
 	spa->spa_indirect_vdevs_loaded = B_TRUE;
+	spa->spa_deflate = (version >= SPA_VERSION_RAIDZ_DEFLATE);
 
 	/*
 	 * Create "The Godfather" zio to hold all async IOs
@@ -7249,7 +7250,6 @@ spa_create(const char *pool, nvlist_t *nvroot, nvlist_t *props,
 
 	/* Newly created pools with the right version are always deflated. */
 	if (version >= SPA_VERSION_RAIDZ_DEFLATE) {
-		spa->spa_deflate = TRUE;
 		if (zap_add(spa->spa_meta_objset,
 		    DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_DEFLATE,
 		    sizeof (uint64_t), 1, &spa->spa_deflate, tx) != 0) {

module/zfs/spa_log_spacemap.c

@@ -1255,10 +1255,9 @@ out:
 		    zfs_range_tree_space(m->ms_unflushed_allocs) -
 		    zfs_range_tree_space(m->ms_unflushed_frees);
 
-		vdev_t *vd = m->ms_group->mg_vd;
-		metaslab_space_update(vd, m->ms_group->mg_class,
+		metaslab_space_update(m->ms_group,
 		    zfs_range_tree_space(m->ms_unflushed_allocs), 0, 0);
-		metaslab_space_update(vd, m->ms_group->mg_class,
+		metaslab_space_update(m->ms_group,
 		    -zfs_range_tree_space(m->ms_unflushed_frees), 0, 0);
 
 		ASSERT0(m->ms_weight & METASLAB_ACTIVE_MASK);

module/zfs/spa_misc.c

@@ -2031,7 +2031,10 @@ spa_update_dspace(spa_t *spa)
 		ASSERT3U(spa->spa_rdspace, >=, spa->spa_nonallocating_dspace);
 		spa->spa_rdspace -= spa->spa_nonallocating_dspace;
 	}
-	spa->spa_dspace = spa->spa_rdspace + ddt_get_dedup_dspace(spa) +
+	spa->spa_dspace = spa->spa_rdspace +
+	    metaslab_class_get_dalloc(spa_special_class(spa)) +
+	    metaslab_class_get_dalloc(spa_dedup_class(spa)) +
+	    ddt_get_dedup_dspace(spa) +
 	    brt_get_dspace(spa);
 }