zdb: temporarily work around dedup log object leak detection

zdb doesn't yet understand the new dedup log objects, and decides they
are leaked blocks. This prevents ztest from working correctly.

This patch notices leaks when dedup log objects are in play, and ignores
them. This is a temporary patch until zdb is fixed, and should not be
merged.

Co-authored-by: Don Brady <don.brady@klarasystems.com>
Signed-off-by: Allan Jude <allan@klarasystems.com>
Sponsored-by: iXsystems, Inc.
Sponsored-By: Klara Inc.

cmd/zdb/zdb.c

@@ -5450,6 +5450,7 @@ typedef struct zdb_cb {
 	uint32_t	**zcb_vd_obsolete_counts;
 	avl_tree_t	zcb_brt;
 	boolean_t	zcb_brt_is_active;
+	boolean_t	zcb_active_ddt_logs;
 } zdb_cb_t;
 
 /* test if two DVA offsets from same vdev are within the same metaslab */
@@ -6127,7 +6128,30 @@ zdb_ddt_leak_init(spa_t *spa, zdb_cb_t *zcb)
 	int error;
 
 	ASSERT(!dump_opt['L']);
+#if 1
+	/*
+	 * XXX - need to account for entries in the ddt logs
+	 * For now we only detect that logs are not empty
+	 */
+	for (enum zio_checksum c = 0; c < ZIO_CHECKSUM_FUNCTIONS; c++) {
+		ddt_t *ddt = spa->spa_ddt[c];
+		if (ddt == NULL)
+			continue;
 
+		if (avl_numnodes(&ddt->ddt_log_active->ddl_tree) > 0 ||
+		    avl_numnodes(&ddt->ddt_log_flushing->ddl_tree) > 0) {
+			printf("zdb_ddt_leak_init: has active ddt logs\n");
+			zcb->zcb_active_ddt_logs = B_TRUE;
+			break;
+		}
+		if (ddt->ddt_log_active->ddl_object != 0 ||
+		    ddt->ddt_log_flushing->ddl_object != 0) {
+			printf("zdb_ddt_leak_init: has ddt log objects\n");
+			zcb->zcb_active_ddt_logs = B_TRUE;
+			break;
+		}
+	}
+#endif
 	while ((error = ddt_walk(spa, &ddb, &ddlwe)) == 0) {
 		blkptr_t blk;
 
@@ -6938,7 +6962,14 @@ dump_block_stats(spa_t *spa)
 		    (u_longlong_t)total_alloc,
 		    (dump_opt['L']) ? "unreachable" : "leaked",
 		    (longlong_t)(total_alloc - total_found));
+#if 1
+		/* XXX - need to account for entries in the ddt logs */
+		if (zcb->zcb_active_ddt_logs)
+			(void) printf("DDT log causing false positive leaks\n");
+		leaks = zcb->zcb_active_ddt_logs ? B_FALSE : B_TRUE;
+#else
 		leaks = B_TRUE;
+#endif
 	}
 
 	if (tzb->zb_count == 0) {
@@ -8031,6 +8062,21 @@ dump_mos_leaks(spa_t *spa)
 			}
 		}
 	}
+#if 1
+	/* Account for FDT objects */
+	for (uint64_t cksum = 0; cksum < ZIO_CHECKSUM_FUNCTIONS; cksum++) {
+		ddt_t *ddt = spa->spa_ddt[cksum];
+		if (!ddt)
+			continue;
+		if (ddt->ddt_dir_object > 0)
+			mos_obj_refd(ddt->ddt_dir_object);
+
+		for (int log = 0; log < 2; log++) {
+			if (ddt->ddt_log[log].ddl_object > 0)
+				mos_obj_refd(ddt->ddt_log[log].ddl_object);
+		}
+	}
+#endif
 
 	if (spa->spa_brt != NULL) {
 		brt_t *brt = spa->spa_brt;