diff --git a/garnet/bin/appmgr/component_controller_impl.cc b/garnet/bin/appmgr/component_controller_impl.cc
index 70d9ed50e6acc4be5831c3c939585a94f43990e4..8c69dbf8606b5867434ef05f076a429e8b47202d 100644
--- a/garnet/bin/appmgr/component_controller_impl.cc
+++ b/garnet/bin/appmgr/component_controller_impl.cc
@@ -9,7 +9,9 @@
 #include <fs/remote-dir.h>
 #include <fs/service.h>
 #include <lib/async/default.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fit/function.h>
 #include <trace/event.h>
 #include <cinttypes>
diff --git a/garnet/bin/appmgr/integration_tests/inspect/test.cc b/garnet/bin/appmgr/integration_tests/inspect/test.cc
index 65943228465a710c05e5e33047ff98a99b9a6d35..21a49d8d04131a0c097c4562fd4422cdb08a14e2 100644
--- a/garnet/bin/appmgr/integration_tests/inspect/test.cc
+++ b/garnet/bin/appmgr/integration_tests/inspect/test.cc
@@ -5,7 +5,9 @@
 #include <fuchsia/inspect/cpp/fidl.h>
 #include <fuchsia/sys/cpp/fidl.h>
 #include <lib/async/default.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 
 #include "gmock/gmock.h"
 #include "lib/component/cpp/environment_services_helper.h"
diff --git a/garnet/bin/appmgr/integration_tests/mock_runner/mock_runner.cc b/garnet/bin/appmgr/integration_tests/mock_runner/mock_runner.cc
index 3b92334d554ce85fc0f5e061d24b4ec6c17d0e10..b6324724a77415d2232d05c835e7d851a96f6941 100644
--- a/garnet/bin/appmgr/integration_tests/mock_runner/mock_runner.cc
+++ b/garnet/bin/appmgr/integration_tests/mock_runner/mock_runner.cc
@@ -6,7 +6,9 @@
 
 #include <memory>
 
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 
 #include "lib/fxl/logging.h"
 
diff --git a/garnet/bin/appmgr/integration_tests/realm_integration_test.cc b/garnet/bin/appmgr/integration_tests/realm_integration_test.cc
index 01a7110220e7d9b17a6cb8e7224795857c96528c..84ddc97f7dfe0fd3686d4462a13858a31f877283 100644
--- a/garnet/bin/appmgr/integration_tests/realm_integration_test.cc
+++ b/garnet/bin/appmgr/integration_tests/realm_integration_test.cc
@@ -18,7 +18,9 @@
 #include <fuchsia/sys/cpp/fidl.h>
 #include <lib/async-loop/cpp/loop.h>
 #include <lib/async/default.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/sys/cpp/file_descriptor.h>
 #include "garnet/bin/appmgr/util.h"
 #include "gmock/gmock.h"
diff --git a/garnet/bin/appmgr/namespace.cc b/garnet/bin/appmgr/namespace.cc
index 36452dae9f6eadea3329666afa7d95e68af5e7f5..bee1322db8df320ab1e45def4f08cbe3099b5f0d 100644
--- a/garnet/bin/appmgr/namespace.cc
+++ b/garnet/bin/appmgr/namespace.cc
@@ -7,7 +7,9 @@
 #include <fuchsia/process/cpp/fidl.h>
 #include <fuchsia/scheduler/cpp/fidl.h>
 #include <lib/async/default.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 
 #include <utility>
 
diff --git a/garnet/bin/appmgr/namespace_builder.cc b/garnet/bin/appmgr/namespace_builder.cc
index ce098ef45c2ff29c391175767dc525b34436c0ca..b73bbb3e6bf0f90478649d30b142a1c83c467c90 100644
--- a/garnet/bin/appmgr/namespace_builder.cc
+++ b/garnet/bin/appmgr/namespace_builder.cc
@@ -5,7 +5,9 @@
 #include "garnet/bin/appmgr/namespace_builder.h"
 
 #include <lib/fdio/limits.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <zircon/processargs.h>
 
 #include <fcntl.h>
diff --git a/garnet/bin/appmgr/namespace_unittest.cc b/garnet/bin/appmgr/namespace_unittest.cc
index 0cec1557d3be17bfd48170b70cbadcadb0e04a1b..6e3fd37a02623db067944088fe2fbe73273689b7 100644
--- a/garnet/bin/appmgr/namespace_unittest.cc
+++ b/garnet/bin/appmgr/namespace_unittest.cc
@@ -13,7 +13,9 @@
 #include <fs/pseudo-dir.h>
 #include <fs/synchronous-vfs.h>
 #include <fuchsia/sys/cpp/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <zircon/status.h>
 #include <zircon/errors.h>
diff --git a/garnet/bin/appmgr/realm.cc b/garnet/bin/appmgr/realm.cc
index b2bc9a51f5cdd2e218f82f21a6652655bbb25a57..c463e7f4b40684927f05261c1587ca9899c50114 100644
--- a/garnet/bin/appmgr/realm.cc
+++ b/garnet/bin/appmgr/realm.cc
@@ -8,7 +8,9 @@
 #include <lib/async/default.h>
 #include <lib/fdio/namespace.h>
 #include <lib/fdio/spawn.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/process.h>
 #include <trace/event.h>
 #include <unistd.h>
diff --git a/garnet/bin/appmgr/service_provider_dir_impl.cc b/garnet/bin/appmgr/service_provider_dir_impl.cc
index 467030fb91d571e4630188012ba03c1e401dff35..a9dfaad4fa720a9b79e3777b5629efddc6689764 100644
--- a/garnet/bin/appmgr/service_provider_dir_impl.cc
+++ b/garnet/bin/appmgr/service_provider_dir_impl.cc
@@ -5,7 +5,9 @@
 #include "garnet/bin/appmgr/service_provider_dir_impl.h"
 
 #include <lib/async/default.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <zircon/status.h>
 
 #include "lib/fxl/logging.h"
diff --git a/garnet/bin/cobalt/app/cobalt_main.cc b/garnet/bin/cobalt/app/cobalt_main.cc
index 0ede7b73eeabbc44e486192e9652fc4d60e16edc..45e81067f4a65d171e2c41e7ffd277c03fa5c40c 100644
--- a/garnet/bin/cobalt/app/cobalt_main.cc
+++ b/garnet/bin/cobalt/app/cobalt_main.cc
@@ -16,7 +16,9 @@
 #include <fuchsia/sysinfo/c/fidl.h>
 #include <lib/async-loop/cpp/loop.h>
 #include <lib/async/cpp/task.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <zircon/boot/image.h>
 
diff --git a/garnet/bin/cobalt/system-metrics/system_metrics_daemon.cc b/garnet/bin/cobalt/system-metrics/system_metrics_daemon.cc
index d063e207e6afc4252ed18ed3481c0efa9ff7b62f..da13fad632b91dad4ff37f70c4fbfdb442863108 100644
--- a/garnet/bin/cobalt/system-metrics/system_metrics_daemon.cc
+++ b/garnet/bin/cobalt/system-metrics/system_metrics_daemon.cc
@@ -14,7 +14,9 @@
 #include <fuchsia/cobalt/cpp/fidl.h>
 #include <fuchsia/sysinfo/c/fidl.h>
 #include <lib/async/cpp/task.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fxl/logging.h>
 #include <lib/zx/resource.h>
 
diff --git a/garnet/bin/crashpad/report_annotations.cc b/garnet/bin/crashpad/report_annotations.cc
index 68ee703fc3f98b002965b1ae6da512cbf2799dd0..d830ecda0bde07b5ffeef8040335b7002af168ef 100644
--- a/garnet/bin/crashpad/report_annotations.cc
+++ b/garnet/bin/crashpad/report_annotations.cc
@@ -10,7 +10,9 @@
 #include <string>
 
 #include <fuchsia/sysinfo/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fxl/files/file.h>
 #include <lib/fxl/strings/trim.h>
 #include <lib/syslog/cpp/logger.h>
diff --git a/garnet/bin/debug_agent/system_info.cc b/garnet/bin/debug_agent/system_info.cc
index 35750261950b222b5b074a13a21c9e3ffedfe903..b5325833bcf504fd51f775857d39cee6e84e6204 100644
--- a/garnet/bin/debug_agent/system_info.cc
+++ b/garnet/bin/debug_agent/system_info.cc
@@ -6,7 +6,9 @@
 
 #include <fcntl.h>
 #include <fuchsia/sysinfo/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <lib/zx/job.h>
 #include <lib/zx/process.h>
diff --git a/garnet/bin/developer/tiles_ctl/main.cc b/garnet/bin/developer/tiles_ctl/main.cc
index 92a69f65acf90687c087220c8d7b7289bc9f6034..927d1b83dc56c875453919c9905c2cb52c5d1031 100644
--- a/garnet/bin/developer/tiles_ctl/main.cc
+++ b/garnet/bin/developer/tiles_ctl/main.cc
@@ -10,7 +10,9 @@
 
 #include <string>
 
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 
 #include "fuchsia/developer/tiles/cpp/fidl.h"
 #include "lib/fsl/io/fd.h"
diff --git a/garnet/bin/display_manager/display.cc b/garnet/bin/display_manager/display.cc
index fbe75a091750b240d3d2b807ef3ca3eb7171f318..21299eb7bee88c621cfd440195a2c2e12d761c12 100644
--- a/garnet/bin/display_manager/display.cc
+++ b/garnet/bin/display_manager/display.cc
@@ -7,7 +7,9 @@
 
 #include <fcntl.h>
 #include <fuchsia/hardware/backlight/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 
 namespace display {
 
diff --git a/garnet/bin/guest/cli/serial.cc b/garnet/bin/guest/cli/serial.cc
index 2ec04c3fefd8a0ab456b7e67f70f6bc283781578..6e969d9053921ca34e292775ee4e023f31e24a08 100644
--- a/garnet/bin/guest/cli/serial.cc
+++ b/garnet/bin/guest/cli/serial.cc
@@ -9,7 +9,9 @@
 
 #include <fuchsia/guest/cpp/fidl.h>
 #include <lib/async/cpp/wait.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fit/function.h>
 
 #include "lib/fsl/socket/socket_drainer.h"
diff --git a/garnet/bin/guest/integration/virtio_block_tests.cc b/garnet/bin/guest/integration/virtio_block_tests.cc
index 9197b1c4de0e93931a6f1534d962b817e7a6e850..d7d6478cd0e83cd6a5b518db2a9ca721dbbb49bd 100644
--- a/garnet/bin/guest/integration/virtio_block_tests.cc
+++ b/garnet/bin/guest/integration/virtio_block_tests.cc
@@ -5,7 +5,9 @@
 #include <fbl/unique_fd.h>
 #include <fcntl.h>
 #include <gmock/gmock.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fxl/arraysize.h>
 #include <lib/fxl/logging.h>
 #include <lib/fxl/strings/string_printf.h>
diff --git a/garnet/bin/guest/pkg/biscotti_guest/bin/guest.cc b/garnet/bin/guest/pkg/biscotti_guest/bin/guest.cc
index 261ef034104ced372b0e8761ad4285b1ee45fca7..d487816cf1164b535eab96a31388c9694840c581 100644
--- a/garnet/bin/guest/pkg/biscotti_guest/bin/guest.cc
+++ b/garnet/bin/guest/pkg/biscotti_guest/bin/guest.cc
@@ -13,7 +13,9 @@
 #include <grpc++/grpc++.h>
 #include <grpc++/server_posix.h>
 #include <lib/async/default.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fidl/cpp/vector.h>
 #include <lib/fxl/logging.h>
 #include <lib/fzl/fdio.h>
diff --git a/garnet/bin/guest/vmm/arch/arm64/gic_distributor.cc b/garnet/bin/guest/vmm/arch/arm64/gic_distributor.cc
index deee517d241098d16adc25305ff544964c3c6c97..b52df6912b20ab0c1197ba56365c0576a355910b 100644
--- a/garnet/bin/guest/vmm/arch/arm64/gic_distributor.cc
+++ b/garnet/bin/guest/vmm/arch/arm64/gic_distributor.cc
@@ -9,7 +9,9 @@
 
 #include <fbl/unique_fd.h>
 #include <fuchsia/sysinfo/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <libzbi/zbi.h>
 #include <zircon/boot/driver-config.h>
diff --git a/garnet/bin/guest/vmm/device/virtio_block_test.cc b/garnet/bin/guest/vmm/device/virtio_block_test.cc
index 791d34532607680a91e731862fbe42a3a15bd453..c100364b8183581877aee7a30dd7459c2a5b2c3f 100644
--- a/garnet/bin/guest/vmm/device/virtio_block_test.cc
+++ b/garnet/bin/guest/vmm/device/virtio_block_test.cc
@@ -6,7 +6,9 @@
 #include <unistd.h>
 
 #include <fbl/unique_fd.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <virtio/block.h>
 
 #include "garnet/bin/guest/vmm/device/block.h"
diff --git a/garnet/bin/guest/vmm/guest.cc b/garnet/bin/guest/vmm/guest.cc
index 3e5b032ceff8df50de3380aea897a3c9e7210686..7396fbe742eb5c258f9015717c4cbd745a9985b6 100644
--- a/garnet/bin/guest/vmm/guest.cc
+++ b/garnet/bin/guest/vmm/guest.cc
@@ -10,7 +10,9 @@
 #include <unistd.h>
 
 #include <fuchsia/sysinfo/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fxl/logging.h>
 #include <lib/fxl/strings/string_printf.h>
 #include <lib/zx/channel.h>
diff --git a/garnet/bin/guest/vmm/main.cc b/garnet/bin/guest/vmm/main.cc
index cc6aece871803fbfde94a578cd583be63492121f..b5e4bdcbe908eeef31387b912ef8e670653e6ea7 100644
--- a/garnet/bin/guest/vmm/main.cc
+++ b/garnet/bin/guest/vmm/main.cc
@@ -21,7 +21,9 @@
 #include <lib/async/cpp/task.h>
 #include <lib/component/cpp/startup_context.h>
 #include <lib/fdio/namespace.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fxl/strings/string_printf.h>
 #include <trace-provider/provider.h>
 #include <zircon/process.h>
diff --git a/garnet/bin/guest/vmm/virtio_net_legacy.cc b/garnet/bin/guest/vmm/virtio_net_legacy.cc
index 5d007cc51b73253e97644916bac5dbd938fcdf6a..179f91eeb2385575b6d5b1dddfd6a9c580475583 100644
--- a/garnet/bin/guest/vmm/virtio_net_legacy.cc
+++ b/garnet/bin/guest/vmm/virtio_net_legacy.cc
@@ -10,7 +10,9 @@
 
 #include <fbl/unique_fd.h>
 #include <fuchsia/hardware/ethernet/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fxl/logging.h>
 #include <trace-engine/types.h>
 #include <trace/event.h>
diff --git a/garnet/bin/insntrace/control.cc b/garnet/bin/insntrace/control.cc
index 45b851f85f469d81d09a54d3df5668a084526467..30ad5837d317155d2e307917e9a656dcef22226c 100644
--- a/garnet/bin/insntrace/control.cc
+++ b/garnet/bin/insntrace/control.cc
@@ -19,7 +19,9 @@
 #include <zircon/device/ktrace.h>
 #include <zircon/syscalls.h>
 
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zircon-internal/ktrace.h>
 #include <lib/zx/handle.h>
 #include <lib/zx/vmo.h>
diff --git a/garnet/bin/insntrace/main.cc b/garnet/bin/insntrace/main.cc
index f0dcb4ce9ea821e78d6c5d224141f8476826c0da..9822d03c6e1c2d213985ceaa273747fe3aa91db5 100644
--- a/garnet/bin/insntrace/main.cc
+++ b/garnet/bin/insntrace/main.cc
@@ -13,7 +13,9 @@
 
 #include <iostream>
 
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 
 #include "lib/fxl/command_line.h"
 #include "lib/fxl/log_settings.h"
diff --git a/garnet/bin/iquery/modes.cc b/garnet/bin/iquery/modes.cc
index efab8b6ffbe3a2813b1ff59d85e6913b99ef7e06..46c029c1a5c078b7b7f37c82198a95c56eb6e829 100644
--- a/garnet/bin/iquery/modes.cc
+++ b/garnet/bin/iquery/modes.cc
@@ -7,7 +7,9 @@
 #include <stack>
 
 #include <fuchsia/io/cpp/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fit/defer.h>
 #include <lib/fxl/files/file.h>
 #include <lib/fxl/files/path.h>
diff --git a/garnet/bin/iquery/testing/test.cc b/garnet/bin/iquery/testing/test.cc
index c652dd5149d98e2056b838cb7fb3987a4147644e..c7cb86d8a3d2c7410e81958d7e219f7569d693fe 100644
--- a/garnet/bin/iquery/testing/test.cc
+++ b/garnet/bin/iquery/testing/test.cc
@@ -6,7 +6,9 @@
 #include <fuchsia/sys/cpp/fidl.h>
 #include <lib/async/default.h>
 #include <lib/fdio/spawn.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <regex>
 
 #include "gmock/gmock.h"
diff --git a/garnet/bin/kernel_crash_checker/main.cc b/garnet/bin/kernel_crash_checker/main.cc
index 3416cc1e160599d4bdeee29e82597485f0df1333..03b5f742d0ef38d83fc66101554665f3ef3afff6 100644
--- a/garnet/bin/kernel_crash_checker/main.cc
+++ b/garnet/bin/kernel_crash_checker/main.cc
@@ -13,7 +13,9 @@
 #include <fuchsia/net/cpp/fidl.h>
 #include <lib/async-loop/cpp/loop.h>
 #include <lib/component/cpp/startup_context.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fidl/cpp/synchronous_interface_ptr.h>
 #include <lib/fsl/vmo/file.h>
 #include <lib/fsl/vmo/strings.h>
diff --git a/garnet/bin/memory_monitor/monitor.cc b/garnet/bin/memory_monitor/monitor.cc
index 8453a2670f2b66d9ac3ea9e429d9cbf4730143f6..0ea74304b78160daa18d8619781106be930ed42e 100644
--- a/garnet/bin/memory_monitor/monitor.cc
+++ b/garnet/bin/memory_monitor/monitor.cc
@@ -12,7 +12,9 @@
 #include <fuchsia/sysinfo/c/fidl.h>
 #include <lib/async/default.h>
 #include <lib/async/cpp/time.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <trace/event.h>
 #include <zircon/status.h>
 
diff --git a/garnet/bin/netstack_tests/netstack_add_eth_test.cc b/garnet/bin/netstack_tests/netstack_add_eth_test.cc
index 3908e21773cdfd8182f546cefb5468723cf792fb..99051e7e795f579f04822e78b3db4e5ab784601c 100644
--- a/garnet/bin/netstack_tests/netstack_add_eth_test.cc
+++ b/garnet/bin/netstack_tests/netstack_add_eth_test.cc
@@ -7,7 +7,9 @@
 #include <fuchsia/hardware/ethernet/cpp/fidl.h>
 #include <fuchsia/net/stack/cpp/fidl.h>
 #include <fuchsia/netstack/cpp/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/watcher.h>
 #include <lib/fidl/cpp/interface_handle.h>
 #include <lib/sys/cpp/file_descriptor.h>
diff --git a/garnet/bin/netstack_tests/netstack_filter_test.cc b/garnet/bin/netstack_tests/netstack_filter_test.cc
index 51307bf6b649fa5bdebeac9757a74013872087e7..a8627108f9e1ff84fbf8069aa336976f10b726cb 100644
--- a/garnet/bin/netstack_tests/netstack_filter_test.cc
+++ b/garnet/bin/netstack_tests/netstack_filter_test.cc
@@ -8,7 +8,9 @@
 #include <fuchsia/net/filter/cpp/fidl.h>
 #include <fuchsia/netstack/cpp/fidl.h>
 #include <garnet/lib/inet/ip_address.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/watcher.h>
 #include <lib/fidl/cpp/interface_handle.h>
 #include <lib/sys/cpp/file_descriptor.h>
diff --git a/garnet/bin/netstack_tests/netstack_ioctl_test.cc b/garnet/bin/netstack_tests/netstack_ioctl_test.cc
index cfde3c337c1e7b3df66280c82f6e335d3f1e08bc..6f89a6672ce72819207adcd5afff9a636d6674d7 100644
--- a/garnet/bin/netstack_tests/netstack_ioctl_test.cc
+++ b/garnet/bin/netstack_tests/netstack_ioctl_test.cc
@@ -7,7 +7,9 @@
 #include <fuchsia/hardware/ethernet/cpp/fidl.h>
 #include <fuchsia/net/stack/cpp/fidl.h>
 #include <fuchsia/netstack/cpp/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/watcher.h>
 #include <lib/fidl/cpp/interface_handle.h>
 #include <lib/netstack/c/netconfig.h>
diff --git a/garnet/bin/network_time/test/system_time_updater_test.cc b/garnet/bin/network_time/test/system_time_updater_test.cc
index c39b501202b477b16ab96edaa0d718c24a654c19..a4190857a16b278531f4da426c84d58c4819d35d 100644
--- a/garnet/bin/network_time/test/system_time_updater_test.cc
+++ b/garnet/bin/network_time/test/system_time_updater_test.cc
@@ -14,7 +14,9 @@
 #include "gmock/gmock.h"
 #include "lib/component/cpp/testing/test_util.h"
 #include "lib/component/cpp/testing/test_with_environment.h"
-#include "lib/fdio/util.h"
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include "lib/fsl/io/fd.h"
 #include "lib/fxl/files/unique_fd.h"
 #include "lib/fxl/strings/string_printf.h"
diff --git a/garnet/bin/network_time/timezone.cc b/garnet/bin/network_time/timezone.cc
index 39bf6662f78f73040cdf88da474620b98625f53e..a6bc94200d51d5b09c2acc61f451aeb6b30fa6dd 100644
--- a/garnet/bin/network_time/timezone.cc
+++ b/garnet/bin/network_time/timezone.cc
@@ -14,7 +14,9 @@
 #include "garnet/bin/network_time/roughtime_server.h"
 #include "garnet/bin/network_time/time_server_config.h"
 #include "garnet/bin/network_time/time_util.h"
-#include "lib/fdio/util.h"
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include "lib/syslog/cpp/logger.h"
 #include "zircon/system/ulib/zx/include/lib/zx/channel.h"
 
diff --git a/garnet/bin/run_test_component/main.cc b/garnet/bin/run_test_component/main.cc
index 77e89c52e492245ecfd21f75bd86c270b4a60b20..fe0630c9b2cd7dcc1a752fc4dd75094dfef58407 100644
--- a/garnet/bin/run_test_component/main.cc
+++ b/garnet/bin/run_test_component/main.cc
@@ -7,7 +7,9 @@
 #include <fuchsia/logger/cpp/fidl.h>
 #include <fuchsia/sys/cpp/fidl.h>
 #include <lib/async-loop/cpp/loop.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/sys/cpp/file_descriptor.h>
 #include <lib/sys/cpp/termination_reason.h>
 
diff --git a/garnet/bin/scpi/app.cc b/garnet/bin/scpi/app.cc
index f4f5818ec279ed93d5b9f3b3e9e30b7aa2fd2a9b..f23202825dc95dab4baa6d03bb004c071ae70a92 100644
--- a/garnet/bin/scpi/app.cc
+++ b/garnet/bin/scpi/app.cc
@@ -5,7 +5,9 @@
 #include "garnet/bin/scpi/app.h"
 #include <ddk/protocol/scpi.h>
 #include <fuchsia/sysinfo/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/watcher.h>
 #include <stdio.h>
 #include <zircon/device/thermal.h>
diff --git a/garnet/bin/sshd-host/sshd-host.cc b/garnet/bin/sshd-host/sshd-host.cc
index 2caeb07b49bf7ba084d36af281649875c6d95e89..2dadb921616d11b52ac7681885d56d6ab2a7f75e 100644
--- a/garnet/bin/sshd-host/sshd-host.cc
+++ b/garnet/bin/sshd-host/sshd-host.cc
@@ -20,7 +20,9 @@
 #include <lib/async/default.h>
 #include <lib/fdio/io.h>
 #include <lib/fdio/spawn.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/job.h>
 #include <lib/zx/process.h>
 #include <zircon/process.h>
diff --git a/garnet/bin/sysmem-assistant/main.cc b/garnet/bin/sysmem-assistant/main.cc
index 4608c68e04fedf2a64f259cf3604d747bdd9ad85..8636d4c1c0589622d63a4e2116744a287fe1789e 100644
--- a/garnet/bin/sysmem-assistant/main.cc
+++ b/garnet/bin/sysmem-assistant/main.cc
@@ -6,7 +6,9 @@
 #include <fbl/unique_fd.h>
 #include <fcntl.h>
 #include <fuchsia/sysmem/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/watcher.h>
 #include <lib/fxl/logging.h>
 #include <stdio.h>
diff --git a/garnet/bin/sysmem_connector/test/sysmem_connector_test.cc b/garnet/bin/sysmem_connector/test/sysmem_connector_test.cc
index 8c96c5781ef49b7c6b3ef40808b834727338fb51..179cf9dd6d78b2e856121372ee010fbf4861160e 100644
--- a/garnet/bin/sysmem_connector/test/sysmem_connector_test.cc
+++ b/garnet/bin/sysmem_connector/test/sysmem_connector_test.cc
@@ -4,7 +4,9 @@
 
 #include <fuchsia/sysmem/cpp/fidl.h>
 #include <lib/async-loop/cpp/loop.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include "gtest/gtest.h"
 #include "lib/component/cpp/startup_context.h"
 #include "lib/fidl/cpp/interface_ptr.h"
diff --git a/garnet/bin/sysmgr/app.cc b/garnet/bin/sysmgr/app.cc
index f0cda9d535ff9d78b24fe677922f6f649e6cba2d..c6c323bb744249ebceb731dd37758870d324ed56 100644
--- a/garnet/bin/sysmgr/app.cc
+++ b/garnet/bin/sysmgr/app.cc
@@ -6,7 +6,9 @@
 
 #include <fs/managed-vfs.h>
 #include <lib/async/default.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <zircon/process.h>
 #include <zircon/processargs.h>
 #include "lib/component/cpp/connect.h"
diff --git a/garnet/bin/sysmgr/integration_tests/package_updating_loader_test.cc b/garnet/bin/sysmgr/integration_tests/package_updating_loader_test.cc
index b58376be121e3b79fcd990fb927f1dc4d801c22f..b115aac17aadbe8412e353f667763c3aa05622de 100644
--- a/garnet/bin/sysmgr/integration_tests/package_updating_loader_test.cc
+++ b/garnet/bin/sysmgr/integration_tests/package_updating_loader_test.cc
@@ -15,7 +15,9 @@
 #include <fuchsia/io/cpp/fidl.h>
 #include <fuchsia/pkg/cpp/fidl.h>
 #include <fuchsia/sys/cpp/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <lib/zx/time.h>
 #include <zircon/errors.h>
diff --git a/garnet/bin/sysmgr/integration_tests/service_startup_test.cc b/garnet/bin/sysmgr/integration_tests/service_startup_test.cc
index f4b634453ba8580c11143681658a4c9d2ec021ef..50695585b9d41a4206eacd7e2b753cbabe348449 100644
--- a/garnet/bin/sysmgr/integration_tests/service_startup_test.cc
+++ b/garnet/bin/sysmgr/integration_tests/service_startup_test.cc
@@ -2,7 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/gtest/real_loop_fixture.h>
 #include <test/sysmgr/cpp/fidl.h>
 #include "garnet/bin/appmgr/appmgr.h"
diff --git a/garnet/bin/system_monitor/harvester/harvester.cc b/garnet/bin/system_monitor/harvester/harvester.cc
index 6ed93ce982846b1e9200e5ee0f0a09dc1a4d19a9..ec5eb06f98329b22cc547f19e1bb22cfe1e57e4f 100644
--- a/garnet/bin/system_monitor/harvester/harvester.cc
+++ b/garnet/bin/system_monitor/harvester/harvester.cc
@@ -23,7 +23,9 @@
 
 #include <fuchsia/memory/cpp/fidl.h>
 #include <fuchsia/sysinfo/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <zircon/status.h>
 
 #include "lib/fxl/command_line.h"
diff --git a/garnet/bin/thermd/thermd.cc b/garnet/bin/thermd/thermd.cc
index 7fb405bf43b790daec06424bd84979156964c588..b7a470eb09f20665d5e00a3d1fa54b9a1fae4185 100644
--- a/garnet/bin/thermd/thermd.cc
+++ b/garnet/bin/thermd/thermd.cc
@@ -10,7 +10,9 @@
 #include <lib/async-loop/cpp/loop.h>
 
 #include <lib/fdio/watcher.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <trace-provider/provider.h>
 #include <trace/event.h>
diff --git a/garnet/bin/thermd/thermd_arm.cc b/garnet/bin/thermd/thermd_arm.cc
index c060c972c50ba77ec03b2dfe1d471b89de21b93f..ccb3ef39b7ce885bd30dc8664a72e5d7ce33e9e6 100644
--- a/garnet/bin/thermd/thermd_arm.cc
+++ b/garnet/bin/thermd/thermd_arm.cc
@@ -6,7 +6,9 @@
 #include <fcntl.h>
 #include <fuchsia/hardware/gpu/clock/c/fidl.h>
 #include <inttypes.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/watcher.h>
 #include <stdio.h>
 #include <string.h>
diff --git a/garnet/examples/bluetooth/bt-le-heart-rate-peripheral/system_load_heart_model.cc b/garnet/examples/bluetooth/bt-le-heart-rate-peripheral/system_load_heart_model.cc
index 64802d7822f4fd3766c626bf9a242e5608574ec6..16b73d3f46de8ab22e9e1874709801b45e3bb032 100644
--- a/garnet/examples/bluetooth/bt-le-heart-rate-peripheral/system_load_heart_model.cc
+++ b/garnet/examples/bluetooth/bt-le-heart-rate-peripheral/system_load_heart_model.cc
@@ -14,7 +14,9 @@
 #include <unistd.h>
 
 #include <fuchsia/sysinfo/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <zircon/status.h>
 #include <zircon/syscalls/object.h>
 
diff --git a/garnet/examples/fidl/echo_server_c/echo_server.c b/garnet/examples/fidl/echo_server_c/echo_server.c
index 6e41355c0c468b4aa55b002f3ed4b297b67d3d4e..231e5a45b2436f30864d2a693e5c637e41d75514 100644
--- a/garnet/examples/fidl/echo_server_c/echo_server.c
+++ b/garnet/examples/fidl/echo_server_c/echo_server.c
@@ -3,7 +3,9 @@
 // found in the LICENSE file.
 
 #include <lib/async-loop/loop.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/svc/dir.h>
 #include <stdio.h>
 #include <zircon/process.h>
diff --git a/garnet/examples/intl/test/intl_wisdom_test.cc b/garnet/examples/intl/test/intl_wisdom_test.cc
index d75f84748963c13960dbab86e8652b6d84a98968..a5c7112817fb5f81eb3770e1bb2b3a2787825558 100644
--- a/garnet/examples/intl/test/intl_wisdom_test.cc
+++ b/garnet/examples/intl/test/intl_wisdom_test.cc
@@ -13,7 +13,9 @@
 #include "gtest/gtest.h"
 #include "lib/component/cpp/testing/test_util.h"
 #include "lib/component/cpp/testing/test_with_environment.h"
-#include "lib/fdio/util.h"
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include "lib/fxl/files/file.h"
 #include "lib/fxl/files/scoped_temp_dir.h"
 #include <lib/sys/cpp/file_descriptor.h>
diff --git a/garnet/examples/media/use_media_decoder/test/use_aac_decoder_test.cc b/garnet/examples/media/use_media_decoder/test/use_aac_decoder_test.cc
index 724eca886e206f87d87d0dbff6f1a5d80727d064..f3e8b95f20c19d3562d17e05bff9d9fc386d99cd 100644
--- a/garnet/examples/media/use_media_decoder/test/use_aac_decoder_test.cc
+++ b/garnet/examples/media/use_media_decoder/test/use_aac_decoder_test.cc
@@ -19,7 +19,9 @@
 
 #include <fuchsia/mediacodec/cpp/fidl.h>
 #include <lib/async-loop/cpp/loop.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include "gtest/gtest.h"
 #include "lib/component/cpp/startup_context.h"
 #include "lib/fidl/cpp/interface_ptr.h"
diff --git a/garnet/examples/ui/hello_pose_buffer_provider/app.cc b/garnet/examples/ui/hello_pose_buffer_provider/app.cc
index badfaa8eacd21dc4d952a6bd5122c803c482c229..466de48b8173ea0e009b391e3878b86460a1cb18 100644
--- a/garnet/examples/ui/hello_pose_buffer_provider/app.cc
+++ b/garnet/examples/ui/hello_pose_buffer_provider/app.cc
@@ -12,7 +12,9 @@
 #include <fuchsia/ui/gfx/cpp/fidl.h>
 #include <lib/async-loop/cpp/loop.h>
 #include <lib/async/cpp/task.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <glm/gtc/type_ptr.hpp>
 #include <glm/gtx/quaternion.hpp>
 #include <glm/gtx/string_cast.hpp>
diff --git a/garnet/examples/ui/hello_views/app.cc b/garnet/examples/ui/hello_views/app.cc
index f0e4eda477f645def72188910b39212eeab25c44..a500a353b5631e9356e24b99eb676d705aa03408 100644
--- a/garnet/examples/ui/hello_views/app.cc
+++ b/garnet/examples/ui/hello_views/app.cc
@@ -8,7 +8,9 @@
 #include <fuchsia/ui/app/cpp/fidl.h>
 #include <fuchsia/ui/scenic/cpp/fidl.h>
 #include <lib/fdio/limits.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/sys/cpp/file_descriptor.h>
 #include <lib/zx/eventpair.h>
 #include <lib/zx/time.h>
diff --git a/garnet/examples/ui/tile/tile_view.cc b/garnet/examples/ui/tile/tile_view.cc
index d5b9e0c07f6798861aad60a3577635f98db76f64..be4a95ca202477e592940de545035b204f46b832 100644
--- a/garnet/examples/ui/tile/tile_view.cc
+++ b/garnet/examples/ui/tile/tile_view.cc
@@ -6,7 +6,9 @@
 
 #include <fuchsia/ui/viewsv1/cpp/fidl.h>
 #include <lib/async/default.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fidl/cpp/optional.h>
 #include <lib/fxl/logging.h>
 #include <lib/fxl/strings/split_string.h>
diff --git a/garnet/go/src/netstack/tests/automated/netstack_loopback_test/loopbacktest.cc b/garnet/go/src/netstack/tests/automated/netstack_loopback_test/loopbacktest.cc
index 4682b7496215a40bf7b4627e9a6e2ab7b045b87b..3bebad326e5233d074b61d7dab3ab10b04ca9308 100644
--- a/garnet/go/src/netstack/tests/automated/netstack_loopback_test/loopbacktest.cc
+++ b/garnet/go/src/netstack/tests/automated/netstack_loopback_test/loopbacktest.cc
@@ -17,7 +17,9 @@
 
 #include <lib/fdio/io.h>
 #include <lib/fdio/unsafe.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 
 #include <zircon/syscalls.h>
 
diff --git a/garnet/go/src/netstack/tests/manual/closetest.c b/garnet/go/src/netstack/tests/manual/closetest.c
index 306deb9594579e9fbe01ce19c3f06bb19395ee97..5791e9e2b18888b3c05bd76809830ec1e1098923 100644
--- a/garnet/go/src/netstack/tests/manual/closetest.c
+++ b/garnet/go/src/netstack/tests/manual/closetest.c
@@ -4,7 +4,9 @@
 
 #include <arpa/inet.h>
 #include <errno.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <netdb.h>
 #include <netinet/in.h>
 #include <stdio.h>
diff --git a/garnet/lib/chrealm/chrealm.cc b/garnet/lib/chrealm/chrealm.cc
index 54abb303884b02db897f5e6f57018c4024fc4790..5e14347cc12ad4a954a414b74c7f22f59a177885 100644
--- a/garnet/lib/chrealm/chrealm.cc
+++ b/garnet/lib/chrealm/chrealm.cc
@@ -13,7 +13,9 @@
 #include <fuchsia/sys/cpp/fidl.h>
 #include <lib/fdio/namespace.h>
 #include <lib/fdio/spawn.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fit/defer.h>
 #include <lib/zx/job.h>
 #include <zircon/compiler.h>
diff --git a/garnet/lib/debugger_utils/sysinfo.cc b/garnet/lib/debugger_utils/sysinfo.cc
index e6cd7d3f2eec9360cf6b0fd07131398a37d38fe9..e2e5aea0edafa9364cb834f0eedb2bcb1ae8d5ae 100644
--- a/garnet/lib/debugger_utils/sysinfo.cc
+++ b/garnet/lib/debugger_utils/sysinfo.cc
@@ -5,7 +5,9 @@
 #include "garnet/lib/debugger_utils/sysinfo.h"
 
 #include <fcntl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <lib/zx/job.h>
 #include <unistd.h>
diff --git a/garnet/lib/magma/src/magma_util/platform/zircon/zircon_platform_sysmem_connection.cc b/garnet/lib/magma/src/magma_util/platform/zircon/zircon_platform_sysmem_connection.cc
index fd3b02467f36b908db73bdd2dd8388900f3650ed..f56905ddbb3891477836126fe4f8aac897ac2fb7 100644
--- a/garnet/lib/magma/src/magma_util/platform/zircon/zircon_platform_sysmem_connection.cc
+++ b/garnet/lib/magma/src/magma_util/platform/zircon/zircon_platform_sysmem_connection.cc
@@ -6,7 +6,9 @@
 
 #include <fuchsia/sysmem/cpp/fidl.h>
 #include <lib/fdio/io.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 
 #include <limits>
diff --git a/garnet/public/lib/component/cpp/environment_services_helper.cc b/garnet/public/lib/component/cpp/environment_services_helper.cc
index 863ad45bae9128cd6e0dd59641dc72389cb758ce..23ff4018eeaeb8bf5d7620b5fc9c7c569be428d2 100644
--- a/garnet/public/lib/component/cpp/environment_services_helper.cc
+++ b/garnet/public/lib/component/cpp/environment_services_helper.cc
@@ -4,7 +4,9 @@
 
 #include "lib/component/cpp/environment_services_helper.h"
 
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 
 #include "lib/component/cpp/startup_context.h"
 
diff --git a/garnet/public/lib/component/cpp/outgoing.cc b/garnet/public/lib/component/cpp/outgoing.cc
index 3160fd946d5936a1a2aa295ffc6b58889dca8b28..4bda543f6b04e4c7d4ce8e7277e0a1deee4d1ca1 100644
--- a/garnet/public/lib/component/cpp/outgoing.cc
+++ b/garnet/public/lib/component/cpp/outgoing.cc
@@ -6,7 +6,9 @@
 
 #include <fuchsia/inspect/cpp/fidl.h>
 #include <lib/async/default.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <zircon/process.h>
 #include <zircon/processargs.h>
 
diff --git a/garnet/public/lib/component/cpp/startup_context.cc b/garnet/public/lib/component/cpp/startup_context.cc
index 3cf04a10df1d661a8a0efb4ac4facccc0c12b9ce..6540f12453822ef2db06290c4242e4942e74fac2 100644
--- a/garnet/public/lib/component/cpp/startup_context.cc
+++ b/garnet/public/lib/component/cpp/startup_context.cc
@@ -5,7 +5,9 @@
 #include "lib/component/cpp/startup_context.h"
 
 #include <lib/async/default.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <zircon/process.h>
 #include <zircon/processargs.h>
 
diff --git a/garnet/public/lib/component/cpp/testing/startup_context_for_test.cc b/garnet/public/lib/component/cpp/testing/startup_context_for_test.cc
index 297559cb65da086578273041aba68131aa3eee04..bc187cb1738153b6d45976485c59e2d1987e301d 100644
--- a/garnet/public/lib/component/cpp/testing/startup_context_for_test.cc
+++ b/garnet/public/lib/component/cpp/testing/startup_context_for_test.cc
@@ -5,7 +5,9 @@
 #include "lib/component/cpp/testing/startup_context_for_test.h"
 
 #include <lib/async/default.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 
 namespace component {
 namespace testing {
diff --git a/garnet/public/lib/component/cpp/testing/test_util.cc b/garnet/public/lib/component/cpp/testing/test_util.cc
index 776953402388ec7b20c22c8dbeb477b4af732966..7a9cbeda1c5598c7cdee10efa99c0a1fab40f751 100644
--- a/garnet/public/lib/component/cpp/testing/test_util.cc
+++ b/garnet/public/lib/component/cpp/testing/test_util.cc
@@ -5,7 +5,9 @@
 #include "lib/component/cpp/testing/test_util.h"
 
 #include <lib/fdio/limits.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 
 namespace component {
 namespace testing {
diff --git a/garnet/public/lib/fsl/io/fd.cc b/garnet/public/lib/fsl/io/fd.cc
index 0cc863386a5b3464cbcd68c8b7287cf6ba6b1596..83e1864de99418962c88bb4fe84eb45f66293d31 100644
--- a/garnet/public/lib/fsl/io/fd.cc
+++ b/garnet/public/lib/fsl/io/fd.cc
@@ -5,7 +5,9 @@
 #include "lib/fsl/io/fd.h"
 
 #include <lib/fdio/limits.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <zircon/processargs.h>
 #include <zircon/syscalls.h>
 
diff --git a/garnet/public/lib/netemul/network/endpoint.cc b/garnet/public/lib/netemul/network/endpoint.cc
index b7276a8a5de9b41ae97291ba1926f5679fa9a75f..ca02a2b5ab223e92afb08b7db618a63f5845de1c 100644
--- a/garnet/public/lib/netemul/network/endpoint.cc
+++ b/garnet/public/lib/netemul/network/endpoint.cc
@@ -4,7 +4,9 @@
 
 #include "endpoint.h"
 #include <fcntl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <zircon/status.h>
 #include <zircon/types.h>
 #include <unordered_set>
diff --git a/garnet/public/lib/netemul/network/ethernet_client.cc b/garnet/public/lib/netemul/network/ethernet_client.cc
index d5c91c0462f545d0f9f16630d4e33a0159479ff6..526b2f7cfedc755dc7dfcec5631848d27c844d87 100644
--- a/garnet/public/lib/netemul/network/ethernet_client.cc
+++ b/garnet/public/lib/netemul/network/ethernet_client.cc
@@ -8,7 +8,9 @@
 #include <fuchsia/hardware/ethernet/cpp/fidl.h>
 #include <lib/async/cpp/wait.h>
 #include <lib/async/default.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/watcher.h>
 #include <lib/fzl/fifo.h>
 #include <zircon/status.h>
diff --git a/garnet/public/lib/svc/cpp/service_namespace.cc b/garnet/public/lib/svc/cpp/service_namespace.cc
index bf81f6328610191a993c3ef135e6cad42ff04e8c..755e26dba83eba862cabbfb568acab3e77d2b4ab 100644
--- a/garnet/public/lib/svc/cpp/service_namespace.cc
+++ b/garnet/public/lib/svc/cpp/service_namespace.cc
@@ -7,7 +7,9 @@
 #include <fcntl.h>
 #include <fs/service.h>
 #include <lib/async/default.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <zircon/device/vfs.h>
 
 #include <utility>
diff --git a/garnet/public/lib/svc/cpp/service_provider_bridge.cc b/garnet/public/lib/svc/cpp/service_provider_bridge.cc
index 07ecdfd2c38218b2aff14f64fcb75f7174e69a6a..8fe662b544c482a8d9c8f87f58aba2925c840175 100644
--- a/garnet/public/lib/svc/cpp/service_provider_bridge.cc
+++ b/garnet/public/lib/svc/cpp/service_provider_bridge.cc
@@ -7,7 +7,9 @@
 #include <fcntl.h>
 #include <fs/service.h>
 #include <lib/async/default.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <zircon/device/vfs.h>
 
 #include <utility>
diff --git a/garnet/public/lib/svc/cpp/services.cc b/garnet/public/lib/svc/cpp/services.cc
index e35859aef71ca15cbb490ff25f0cdfcd5ec11939..27bd67e44c5135e6ffbf642b34132462cff25d07 100644
--- a/garnet/public/lib/svc/cpp/services.cc
+++ b/garnet/public/lib/svc/cpp/services.cc
@@ -4,7 +4,9 @@
 
 #include "lib/svc/cpp/services.h"
 
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 
 #include "lib/fxl/logging.h"
 
diff --git a/garnet/tests/zircon/libdriver-integration-test/integration-test.cc b/garnet/tests/zircon/libdriver-integration-test/integration-test.cc
index f70b9f93f86d71991401949579d7a09bc33c722a..2bde76aca5e5548f9766cbd57166da564b75b1d1 100644
--- a/garnet/tests/zircon/libdriver-integration-test/integration-test.cc
+++ b/garnet/tests/zircon/libdriver-integration-test/integration-test.cc
@@ -8,7 +8,9 @@
 
 #include <lib/async_promise/executor.h>
 #include <lib/fdio/unsafe.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fit/bridge.h>
 #include <zircon/status.h>
 
diff --git a/garnet/tests/zircon/libdriver-integration-test/root-mock-device.cc b/garnet/tests/zircon/libdriver-integration-test/root-mock-device.cc
index 29205b608ed5520545172392705a237af956d9e9..3109043c5963b6533c053d07be93029123e9ad81 100644
--- a/garnet/tests/zircon/libdriver-integration-test/root-mock-device.cc
+++ b/garnet/tests/zircon/libdriver-integration-test/root-mock-device.cc
@@ -15,7 +15,9 @@
 #include <fuchsia/device/test/c/fidl.h>
 #include <lib/devmgr-integration-test/fixture.h>
 #include <lib/fdio/unsafe.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <zircon/assert.h>
 
 #define DRIVER_TEST_DIR "/boot/driver/test"
diff --git a/peridot/bin/ledger/app/ledger_repository_factory_impl.cc b/peridot/bin/ledger/app/ledger_repository_factory_impl.cc
index 02e711dc2cf81e5053e4ed17171b42059554bc9b..ca6cebd4170eb6d332c7be9f246bdb3479da745e 100644
--- a/peridot/bin/ledger/app/ledger_repository_factory_impl.cc
+++ b/peridot/bin/ledger/app/ledger_repository_factory_impl.cc
@@ -12,7 +12,9 @@
 #include <lib/backoff/exponential_backoff.h>
 #include <lib/component/cpp/expose.h>
 #include <lib/component/cpp/object_dir.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fit/function.h>
 #include <lib/fsl/io/fd.h>
 #include <lib/fxl/files/directory.h>
diff --git a/peridot/bin/module_resolver/module_package_indexer/main.cc b/peridot/bin/module_resolver/module_package_indexer/main.cc
index 83a5cdca4dab01cbb3656a368cfd3c8621295f5a..e68151ebc1870a30e9426c840fc9a13c9c8eb8d7 100644
--- a/peridot/bin/module_resolver/module_package_indexer/main.cc
+++ b/peridot/bin/module_resolver/module_package_indexer/main.cc
@@ -11,7 +11,9 @@
 
 #include <fuchsia/maxwell/internal/cpp/fidl.h>
 #include <lib/async-loop/cpp/loop.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fxl/command_line.h>
 #include <lib/fxl/files/file.h>
 #include <lib/fxl/log_settings_command_line.h>
diff --git a/peridot/bin/sessionctl/main.cc b/peridot/bin/sessionctl/main.cc
index c863ec564c700b04998f9985a70fe18399ab6817..06f1e81f30c248403ca3cb809066e05a278b34b4 100644
--- a/peridot/bin/sessionctl/main.cc
+++ b/peridot/bin/sessionctl/main.cc
@@ -17,7 +17,9 @@
 #include <lib/async-loop/cpp/loop.h>
 #include <lib/async/cpp/future.h>
 #include <lib/async/cpp/task.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fxl/command_line.h>
 #include <lib/fxl/files/file.h>
 #include <lib/fxl/log_settings_command_line.h>
diff --git a/peridot/bin/test_driver/test_driver_module.cc b/peridot/bin/test_driver/test_driver_module.cc
index 2580de3f67ce2c322ab0eb62d149c71dbac38eda..2e6cac232bafacc7616771436484406058a93e75 100644
--- a/peridot/bin/test_driver/test_driver_module.cc
+++ b/peridot/bin/test_driver/test_driver_module.cc
@@ -8,7 +8,9 @@
 #include <lib/component/cpp/connect.h>
 #include <lib/component/cpp/startup_context.h>
 #include <lib/fdio/limits.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fsl/vmo/strings.h>
 
 #include "peridot/lib/rapidjson/rapidjson.h"
diff --git a/peridot/lib/fidl/app_client.cc b/peridot/lib/fidl/app_client.cc
index bd0c12205f84d349ba38b6e081935e1fe88aa60b..c29226a3f07eea7c977d74aa53e2cecbd5b6a678 100644
--- a/peridot/lib/fidl/app_client.cc
+++ b/peridot/lib/fidl/app_client.cc
@@ -8,7 +8,9 @@
 
 #include <fuchsia/sys/cpp/fidl.h>
 #include <lib/fdio/limits.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fsl/io/fd.h>
 #include <lib/fxl/files/directory.h>
 #include <lib/fxl/files/unique_fd.h>
diff --git a/peridot/lib/scoped_tmpfs/scoped_tmpfs.cc b/peridot/lib/scoped_tmpfs/scoped_tmpfs.cc
index 33a5f0f5e34256be2ba4f70548a9a4105f303211..3ed0aa628872d1bd9dc166a33478c4bf6f344ed9 100644
--- a/peridot/lib/scoped_tmpfs/scoped_tmpfs.cc
+++ b/peridot/lib/scoped_tmpfs/scoped_tmpfs.cc
@@ -4,7 +4,9 @@
 
 #include "peridot/lib/scoped_tmpfs/scoped_tmpfs.h"
 
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fsl/io/fd.h>
 #include <lib/fxl/logging.h>
 #include <lib/sync/completion.h>
diff --git a/sdk/lib/svc/dir_unittest.cc b/sdk/lib/svc/dir_unittest.cc
index 487f32e4ba0771841352419ed525316cbb6525f9..71644501c48b8c1ebb3c55c29bccf4b9715adced 100644
--- a/sdk/lib/svc/dir_unittest.cc
+++ b/sdk/lib/svc/dir_unittest.cc
@@ -4,7 +4,9 @@
 
 #include "lib/svc/dir.h"
 
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 
 #include <thread>
diff --git a/sdk/lib/vfs/cpp/file_unittest.cc b/sdk/lib/vfs/cpp/file_unittest.cc
index 8a10c208909e3c89394f19dee62adcdc024e0d04..b1a25de1b324eded6b54bf3ccf2b8ce85afdc01f 100644
--- a/sdk/lib/vfs/cpp/file_unittest.cc
+++ b/sdk/lib/vfs/cpp/file_unittest.cc
@@ -4,7 +4,9 @@
 
 #include <lib/async-loop/cpp/loop.h>
 #include <lib/fdio/limits.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <unistd.h>
 #include <zircon/processargs.h>
 
diff --git a/sdk/lib/vfs/cpp/pseudo_file_unittest.cc b/sdk/lib/vfs/cpp/pseudo_file_unittest.cc
index f0019ec141cf1340f5e7ba8159ea4f610c5158e2..3364155a06033f2f1bc13636a800359df27067ff 100644
--- a/sdk/lib/vfs/cpp/pseudo_file_unittest.cc
+++ b/sdk/lib/vfs/cpp/pseudo_file_unittest.cc
@@ -4,7 +4,9 @@
 
 #include <lib/async-loop/cpp/loop.h>
 #include <lib/fdio/limits.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <unistd.h>
 #include <zircon/processargs.h>
 
diff --git a/zircon/docs/ddk/simple.md b/zircon/docs/ddk/simple.md
index b48200a5ee431c054596d18cb677c2cbb756d6b4..2867e933cce205092f16fbca762890fb0739a517 100644
--- a/zircon/docs/ddk/simple.md
+++ b/zircon/docs/ddk/simple.md
@@ -656,7 +656,7 @@ The complete program is as follows:
 #include <ctype.h>
 
 #include <zircon/syscalls.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fdio.h>
 
 // (1) include the generated definition file
 #include <zircon/sample/number/c/fidl.h>
diff --git a/zircon/system/core/bootsvc/main.cpp b/zircon/system/core/bootsvc/main.cpp
index d352f1850de1f634ed42fbeb09d8806b81262418..3d07603be411925e95e3fe23150238d1ae7563b4 100644
--- a/zircon/system/core/bootsvc/main.cpp
+++ b/zircon/system/core/bootsvc/main.cpp
@@ -11,7 +11,7 @@
 #include <launchpad/launchpad.h>
 #include <lib/async-loop/cpp/loop.h>
 #include <lib/bootsvc-protocol/processargs.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fdio.h>
 #include <lib/zx/debuglog.h>
 #include <zircon/boot/bootdata.h>
 #include <zircon/dlfcn.h>
diff --git a/zircon/system/core/devmgr/devhost/devhost.cpp b/zircon/system/core/devmgr/devhost/devhost.cpp
index c678c11eb491ae253bab53e0e1e18719f4fcccf6..47e9030100172e7b4dbe0bc87fa340467011042c 100644
--- a/zircon/system/core/devmgr/devhost/devhost.cpp
+++ b/zircon/system/core/devmgr/devhost/devhost.cpp
@@ -33,7 +33,7 @@
 #include <lib/async-loop/cpp/loop.h>
 #include <lib/async/cpp/receiver.h>
 #include <lib/async/cpp/wait.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fdio.h>
 #include <lib/fidl/coding.h>
 #include <lib/zx/debuglog.h>
 #include <lib/zx/resource.h>
@@ -41,11 +41,11 @@
 #include <lib/zxio/null.h>
 
 #include "../shared/async-loop-owned-rpc-handler.h"
-#include "main.h"
-#include "tracing.h"
 #include "../shared/env.h"
 #include "../shared/fidl_txn.h"
 #include "../shared/log.h"
+#include "main.h"
+#include "tracing.h"
 
 zx_status_t zx_driver::Create(fbl::RefPtr<zx_driver>* out_driver) {
     *out_driver = fbl::AdoptRef(new zx_driver());
diff --git a/zircon/system/core/devmgr/devmgr/devfs.cpp b/zircon/system/core/devmgr/devmgr/devfs.cpp
index 4c779f5a99173b81a44c5e92832179451eaba0eb..b10c18882791d791bfa2205d79e4814e9c5985fb 100644
--- a/zircon/system/core/devmgr/devmgr/devfs.cpp
+++ b/zircon/system/core/devmgr/devmgr/devfs.cpp
@@ -19,7 +19,7 @@
 #include <fs/handler.h>
 #include <fuchsia/io/c/fidl.h>
 #include <lib/async/cpp/wait.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/directory.h>
 #include <lib/fidl/coding.h>
 #include <lib/memfs/cpp/vnode.h>
 
diff --git a/zircon/system/core/devmgr/devmgr/main.cpp b/zircon/system/core/devmgr/devmgr/main.cpp
index b105bcc3287982f78c391a419060a9f74d66dd6d..a7d26da9a3aed5040fdcac2c1b674dc3ebc552bd 100644
--- a/zircon/system/core/devmgr/devmgr/main.cpp
+++ b/zircon/system/core/devmgr/devmgr/main.cpp
@@ -33,7 +33,9 @@
 #include <lib/fdio/io.h>
 #include <lib/fdio/namespace.h>
 #include <lib/fdio/spawn.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/watcher.h>
 #include <lib/zx/debuglog.h>
 #include <lib/zx/event.h>
diff --git a/zircon/system/core/devmgr/fshost/block-watcher.cpp b/zircon/system/core/devmgr/fshost/block-watcher.cpp
index 24ce6419f6bee2beeb6c5d972860d49e70c36aea..c429c273bde4d8c3f6af74ea70a4f0f6b4adf55c 100644
--- a/zircon/system/core/devmgr/fshost/block-watcher.cpp
+++ b/zircon/system/core/devmgr/fshost/block-watcher.cpp
@@ -15,7 +15,9 @@
 #include <fuchsia/device/c/fidl.h>
 #include <gpt/gpt.h>
 #include <lib/fdio/unsafe.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/watcher.h>
 #include <lib/zx/channel.h>
 #include <lib/zx/process.h>
diff --git a/zircon/system/core/devmgr/fshost/main.cpp b/zircon/system/core/devmgr/fshost/main.cpp
index 17221a71676cb5974c94cffe52701d36292150aa..9f20f105eafe1be78ee5cf952a5961ddb9044abe 100644
--- a/zircon/system/core/devmgr/fshost/main.cpp
+++ b/zircon/system/core/devmgr/fshost/main.cpp
@@ -9,7 +9,9 @@
 #include <fbl/unique_fd.h>
 #include <lib/bootfs/parser.h>
 #include <lib/fdio/namespace.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/watcher.h>
 #include <lib/fit/defer.h>
 #include <lib/zx/channel.h>
diff --git a/zircon/system/core/devmgr/shared/fdio.cpp b/zircon/system/core/devmgr/shared/fdio.cpp
index 1dc0807d4378c44ea831bcbd6a227724f7387973..0e3da25005ee6926a7a563a0f4940ac997853c8d 100644
--- a/zircon/system/core/devmgr/shared/fdio.cpp
+++ b/zircon/system/core/devmgr/shared/fdio.cpp
@@ -7,7 +7,9 @@
 #include <fbl/vector.h>
 #include <lib/fdio/io.h>
 #include <lib/fdio/spawn.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <lib/zx/debuglog.h>
 #include <lib/zx/job.h>
diff --git a/zircon/system/core/netsvc/netboot.cpp b/zircon/system/core/netsvc/netboot.cpp
index 766827e3441bf1b337d660d09b6999ca83d46bcd..c6df12574c340bdcf0d1c82d29e1fb9faf9a8dc0 100644
--- a/zircon/system/core/netsvc/netboot.cpp
+++ b/zircon/system/core/netsvc/netboot.cpp
@@ -18,7 +18,9 @@
 #include <fuchsia/device/manager/c/fidl.h>
 #include <inet6/inet6.h>
 #include <inet6/netifc.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <zircon/boot/netboot.h>
 #include <zircon/process.h>
 #include <zircon/processargs.h>
diff --git a/zircon/system/core/pwrbtn-monitor/pwrbtn-monitor.cpp b/zircon/system/core/pwrbtn-monitor/pwrbtn-monitor.cpp
index baa306877de6267a5aa9ad2a68f9eadeb454a14e..beb4798f24af94063e21bc112820418364e5e3bf 100644
--- a/zircon/system/core/pwrbtn-monitor/pwrbtn-monitor.cpp
+++ b/zircon/system/core/pwrbtn-monitor/pwrbtn-monitor.cpp
@@ -15,7 +15,9 @@
 #include <fuchsia/hardware/input/c/fidl.h>
 #include <hid-parser/parser.h>
 #include <hid-parser/usages.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/watcher.h>
 #include <lib/fzl/fdio.h>
 #include <zircon/processargs.h>
diff --git a/zircon/system/core/svchost/crashsvc.cpp b/zircon/system/core/svchost/crashsvc.cpp
index 156584f85f69a9bf54a19b4c37ce750471b01ff4..04e8f43262f774692138cccbfba2fa4c1301db94 100644
--- a/zircon/system/core/svchost/crashsvc.cpp
+++ b/zircon/system/core/svchost/crashsvc.cpp
@@ -10,7 +10,9 @@
 #include <fuchsia/crash/c/fidl.h>
 #include <inspector/inspector.h>
 
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <lib/zx/handle.h>
 #include <lib/zx/job.h>
diff --git a/zircon/system/core/svchost/svchost.cpp b/zircon/system/core/svchost/svchost.cpp
index c69fe89a334939b13d31bbf5d8c67ff1ecddae6f..34576cbee765491ec9ce829a65e07793705ce243 100644
--- a/zircon/system/core/svchost/svchost.cpp
+++ b/zircon/system/core/svchost/svchost.cpp
@@ -7,7 +7,9 @@
 #include <fbl/algorithm.h>
 #include <fuchsia/net/c/fidl.h>
 #include <lib/async-loop/cpp/loop.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/logger/provider.h>
 #include <lib/process-launcher/launcher.h>
 #include <lib/profile/profile.h>
diff --git a/zircon/system/core/virtcon/main.cpp b/zircon/system/core/virtcon/main.cpp
index a82ff8cc13ca2d26707b231a014b591ea98f5e3c..67ad269a52a34d2f8dab732d957a8a69c27fccfb 100644
--- a/zircon/system/core/virtcon/main.cpp
+++ b/zircon/system/core/virtcon/main.cpp
@@ -15,7 +15,9 @@
 #include <fuchsia/io/c/fidl.h>
 #include <lib/fdio/io.h>
 #include <lib/fdio/spawn.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/watcher.h>
 #include <lib/fzl/fdio.h>
 #include <lib/zx/channel.h>
diff --git a/zircon/system/uapp/clock/clock.c b/zircon/system/uapp/clock/clock.c
index 4826450cdcc7118d30e26761a1659360a8a61d68..2ebcfc3752e2c677be404d1046a5968b78014538 100644
--- a/zircon/system/uapp/clock/clock.c
+++ b/zircon/system/uapp/clock/clock.c
@@ -3,7 +3,9 @@
 // found in the LICENSE file.
 
 #include <fuchsia/hardware/rtc/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 
 #include <ctype.h>
 #include <dirent.h>
diff --git a/zircon/system/uapp/dd/main.c b/zircon/system/uapp/dd/main.c
index 164b5eabd88cfec1c5b3bd4c03b9844a3740feaa..2d2dc40a4a62c9d345ea710f06078cd274d5694f 100644
--- a/zircon/system/uapp/dd/main.c
+++ b/zircon/system/uapp/dd/main.c
@@ -15,7 +15,9 @@
 #include <unistd.h>
 
 #include <fuchsia/hardware/skipblock/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <zircon/process.h>
 #include <zircon/syscalls.h>
 
diff --git a/zircon/system/uapp/disk-pave/device-partitioner.cpp b/zircon/system/uapp/disk-pave/device-partitioner.cpp
index 867c81f93ba9b8bf10d07be29fc13e8cee519c88..741c1bcd22b79e9d0c7745771e143fd3506ff5cc 100644
--- a/zircon/system/uapp/disk-pave/device-partitioner.cpp
+++ b/zircon/system/uapp/disk-pave/device-partitioner.cpp
@@ -16,7 +16,9 @@
 #include <fuchsia/hardware/skipblock/c/fidl.h>
 #include <gpt/cros.h>
 #include <lib/fdio/unsafe.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/watcher.h>
 #include <lib/fzl/fdio.h>
 #include <zircon/status.h>
diff --git a/zircon/system/uapp/display-test/image.cpp b/zircon/system/uapp/display-test/image.cpp
index d07a6fa1869856cfae13f6cf51a6f1d81089f43e..2e6582211ac59ca0570ff9992b6891fe9060745b 100644
--- a/zircon/system/uapp/display-test/image.cpp
+++ b/zircon/system/uapp/display-test/image.cpp
@@ -4,7 +4,9 @@
 
 #include <fbl/algorithm.h>
 #include <lib/fdio/unsafe.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <lib/zx/event.h>
 #include <lib/zx/vmar.h>
diff --git a/zircon/system/uapp/ethtool/ethtool.c b/zircon/system/uapp/ethtool/ethtool.c
index 6352d67d89701ed94ae4580ec28c2bcdd7c9b50b..b7e04656371d3876832054df43e13a54161bb12c 100644
--- a/zircon/system/uapp/ethtool/ethtool.c
+++ b/zircon/system/uapp/ethtool/ethtool.c
@@ -4,7 +4,9 @@
 
 #include <fuchsia/hardware/ethernet/c/fidl.h>
 #include <inet6/inet6.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <zircon/assert.h>
 #include <zircon/boot/netboot.h>
 #include <zircon/process.h>
diff --git a/zircon/system/uapp/fs-fsck/main.c b/zircon/system/uapp/fs-fsck/main.c
index f20d4046631efcfee453bad91dbeb0273b90bbf3..1c662c9607e26d3bdf41aa34bbca7825b79ea4dc 100644
--- a/zircon/system/uapp/fs-fsck/main.c
+++ b/zircon/system/uapp/fs-fsck/main.c
@@ -16,7 +16,9 @@
 #include <zircon/compiler.h>
 #include <zircon/processargs.h>
 #include <zircon/syscalls.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 
 struct {
     const char* name;
diff --git a/zircon/system/uapp/fs-mkfs/main.c b/zircon/system/uapp/fs-mkfs/main.c
index e739babdd1adc49fe137835c9e06881a12360552..ca6b51b06029fe4c9cc8cd3590aaa51302c37ed3 100644
--- a/zircon/system/uapp/fs-mkfs/main.c
+++ b/zircon/system/uapp/fs-mkfs/main.c
@@ -14,7 +14,9 @@
 #include <unistd.h>
 
 #include <fs-management/mount.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <zircon/compiler.h>
 #include <zircon/processargs.h>
 #include <zircon/syscalls.h>
diff --git a/zircon/system/uapp/fs-mount/main.c b/zircon/system/uapp/fs-mount/main.c
index 0adab20cc65ae69de092cd8e5397116bf1af3c30..001d50ecf66d754fb5fbfe9d00e9534cd363735c 100644
--- a/zircon/system/uapp/fs-mount/main.c
+++ b/zircon/system/uapp/fs-mount/main.c
@@ -16,7 +16,9 @@
 #include <fs-management/mount.h>
 #include <zircon/processargs.h>
 #include <zircon/syscalls.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 
 
 int usage(void) {
diff --git a/zircon/system/uapp/i2c/i2c.c b/zircon/system/uapp/i2c/i2c.c
index d79ee5b1b0d2cf29c5e9b0b3ff2088a609d43e2b..76550a320326f00970c7be6b8a9f7ca921a8e827 100644
--- a/zircon/system/uapp/i2c/i2c.c
+++ b/zircon/system/uapp/i2c/i2c.c
@@ -6,7 +6,9 @@
 #include <fcntl.h>
 #include <fuchsia/hardware/i2c/c/fidl.h>
 #include <lib/fdio/unsafe.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/zircon/system/uapp/kstress/main.cpp b/zircon/system/uapp/kstress/main.cpp
index 5841fec5d2de785f023757cfa58675fdc8547bb2..cb5483d6f02247919f1a71ad9f9fc536427d2b30 100644
--- a/zircon/system/uapp/kstress/main.cpp
+++ b/zircon/system/uapp/kstress/main.cpp
@@ -5,7 +5,9 @@
 #include <fbl/unique_ptr.h>
 #include <fbl/vector.h>
 #include <fuchsia/sysinfo/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <lib/zx/resource.h>
 #include <zircon/status.h>
diff --git a/zircon/system/uapp/light/light.cpp b/zircon/system/uapp/light/light.cpp
index cdadd31fa651792e9b9ab4eec83c07196795f0b6..27acc80e28f10a97c79a75c124a7f1251daf60c7 100644
--- a/zircon/system/uapp/light/light.cpp
+++ b/zircon/system/uapp/light/light.cpp
@@ -10,7 +10,9 @@
 
 #include <fbl/auto_call.h>
 #include <fuchsia/hardware/light/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <zircon/status.h>
 #include <zircon/syscalls.h>
 #include <zircon/types.h>
diff --git a/zircon/system/uapp/lsdev/lsdev.c b/zircon/system/uapp/lsdev/lsdev.c
index 8ea103f3dd7d784bc26ff87019e0afb370314dbc..4d89cd0e45fd777f46e5017d543a4c5c0e800ebe 100644
--- a/zircon/system/uapp/lsdev/lsdev.c
+++ b/zircon/system/uapp/lsdev/lsdev.c
@@ -3,7 +3,9 @@
 // found in the LICENSE file.
 
 #include <fuchsia/device/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <zircon/syscalls.h>
 #include <zircon/status.h>
 #include <zircon/types.h>
diff --git a/zircon/system/uapp/lspwr/lspwr.cpp b/zircon/system/uapp/lspwr/lspwr.cpp
index 1babe782aaaa63d1b6d7ba01bc13cdf2fdb5a4f0..636b37d13a2199f108a147973075960dbddf9df2 100644
--- a/zircon/system/uapp/lspwr/lspwr.cpp
+++ b/zircon/system/uapp/lspwr/lspwr.cpp
@@ -9,7 +9,9 @@
 #include <fcntl.h>
 #include <fuchsia/hardware/power/c/fidl.h>
 #include <lib/fdio/unsafe.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/zircon/system/uapp/lsusb/lsusb.c b/zircon/system/uapp/lsusb/lsusb.c
index af1a78dcc9262c0b0d7395973cab4c8522647bc1..1b380084ee776700b4bd6180a692c9ad9b05ec1a 100644
--- a/zircon/system/uapp/lsusb/lsusb.c
+++ b/zircon/system/uapp/lsusb/lsusb.c
@@ -4,7 +4,9 @@
 
 #include <zircon/types.h>
 #include <lib/fdio/io.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <dirent.h>
 #include <endian.h>
 #include <fcntl.h>
diff --git a/zircon/system/uapp/nand-util/nand-broker.cpp b/zircon/system/uapp/nand-util/nand-broker.cpp
index f2b2f7bbc7842463e81a7d41d01822caeac07255..1c1a2dd8d20721398464cd430c1f95b1e70688dd 100644
--- a/zircon/system/uapp/nand-util/nand-broker.cpp
+++ b/zircon/system/uapp/nand-util/nand-broker.cpp
@@ -11,7 +11,9 @@
 
 #include <fuchsia/device/c/fidl.h>
 #include <fuchsia/nand/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/unsafe.h>
 #include <lib/fdio/watcher.h>
 #include <lib/zx/vmo.h>
diff --git a/zircon/system/uapp/netdump/netdump.c b/zircon/system/uapp/netdump/netdump.c
index dce81fefdb5fcc7d9fc1813eaa028e3c914b54e3..5c29c0a8049ad7cb37343954de7403759d8018ef 100644
--- a/zircon/system/uapp/netdump/netdump.c
+++ b/zircon/system/uapp/netdump/netdump.c
@@ -4,7 +4,9 @@
 
 #include <fuchsia/hardware/ethernet/c/fidl.h>
 #include <inet6/inet6.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <pretty/hexdump.h>
 #include <zircon/assert.h>
 #include <zircon/boot/netboot.h>
diff --git a/zircon/system/uapp/psutils/resources.c b/zircon/system/uapp/psutils/resources.c
index 02bda7bef6efc1450abd7367f35e210bc6b4456d..3737f79c971accf92f026f128065dad2ddd21085 100644
--- a/zircon/system/uapp/psutils/resources.c
+++ b/zircon/system/uapp/psutils/resources.c
@@ -5,7 +5,9 @@
 #include "resources.h"
 
 #include <fuchsia/sysinfo/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <zircon/status.h>
 #include <zircon/syscalls.h>
 
diff --git a/zircon/system/uapp/run-vc/main.c b/zircon/system/uapp/run-vc/main.c
index 209fd84510c0429df4aa9e0c6326f6281babd01c..782e568019c947d168c559bc482394804d2cdf6b 100644
--- a/zircon/system/uapp/run-vc/main.c
+++ b/zircon/system/uapp/run-vc/main.c
@@ -6,7 +6,9 @@
 #include <fuchsia/device/manager/c/fidl.h>
 #include <lib/fdio/io.h>
 #include <lib/fdio/spawn.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/watcher.h>
 #include <limits.h>
 #include <stdbool.h>
diff --git a/zircon/system/uapp/suspendtest/suspendtest.c b/zircon/system/uapp/suspendtest/suspendtest.c
index 4db58f6ffe6c414d5361f9c5040cde72b0378a1e..3deda3d4757cd8d581809614de55abb74e09c5ff 100644
--- a/zircon/system/uapp/suspendtest/suspendtest.c
+++ b/zircon/system/uapp/suspendtest/suspendtest.c
@@ -3,7 +3,9 @@
 // found in the LICENSE file.
 
 #include <fuchsia/device/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <zircon/syscalls.h>
 #include <zircon/status.h>
 #include <zircon/types.h>
diff --git a/zircon/system/uapp/unbind/main.cpp b/zircon/system/uapp/unbind/main.cpp
index a0dfcbc41d7622bf96c7293d7491c18dbe9aa49a..a3570d588435fed3370d4d31039339cbd9af41db 100644
--- a/zircon/system/uapp/unbind/main.cpp
+++ b/zircon/system/uapp/unbind/main.cpp
@@ -8,7 +8,9 @@
 #include <stdlib.h>
 
 #include <fuchsia/device/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 
 namespace {
diff --git a/zircon/system/uapp/usb-fwloader/usb-fwloader.cpp b/zircon/system/uapp/usb-fwloader/usb-fwloader.cpp
index 18d36d8fc54ef4d5d92f2e03f4754b33f5ec8866..554262e16f75d03eec807638801019440feea4a5 100644
--- a/zircon/system/uapp/usb-fwloader/usb-fwloader.cpp
+++ b/zircon/system/uapp/usb-fwloader/usb-fwloader.cpp
@@ -10,7 +10,9 @@
 #include <fuchsia/hardware/usb/fwloader/c/fidl.h>
 #include <fuchsia/mem/c/fidl.h>
 #include <lib/fdio/unsafe.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/watcher.h>
 #include <lib/fzl/fdio.h>
 #include <lib/zx/channel.h>
diff --git a/zircon/system/uapp/usbctl/usbctl.c b/zircon/system/uapp/usbctl/usbctl.c
index 2a3b88f6b9f033c3481a03cfe106dd97dd6fb406..68b6114d1bc536c3f0a9321804228225232ab29f 100644
--- a/zircon/system/uapp/usbctl/usbctl.c
+++ b/zircon/system/uapp/usbctl/usbctl.c
@@ -5,13 +5,17 @@
 #include <dirent.h>
 #include <fcntl.h>
 #include <fuchsia/hardware/usb/peripheral/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <ddk/protocol/usb/modeswitch.h>
 #include <fuchsia/usb/virtualbus/c/fidl.h>
 
diff --git a/zircon/system/ulib/cobalt-client/cobalt_logger.cpp b/zircon/system/ulib/cobalt-client/cobalt_logger.cpp
index 4f89680ba4813c628b0f64d21159684400a32ea6..39fd39bdac6efb68dc477e4d4e1f5abea1031daf 100644
--- a/zircon/system/ulib/cobalt-client/cobalt_logger.cpp
+++ b/zircon/system/ulib/cobalt-client/cobalt_logger.cpp
@@ -4,7 +4,9 @@
 
 #include <cobalt-client/cpp/collector-internal.h>
 #include <fuchsia/cobalt/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fidl/coding.h>
 #include <lib/fidl/cpp/vector_view.h>
 
diff --git a/zircon/system/ulib/cobalt-client/collector.cpp b/zircon/system/ulib/cobalt-client/collector.cpp
index fc707bbe92506d097580f2ed7b6a6d3836919ba6..ee8251f5f300a24beb47bae9bfb9d1964a945bc4 100644
--- a/zircon/system/ulib/cobalt-client/collector.cpp
+++ b/zircon/system/ulib/cobalt-client/collector.cpp
@@ -12,7 +12,9 @@
 #include <cobalt-client/cpp/collector-internal.h>
 
 #include <fuchsia/cobalt/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fidl/cpp/vector_view.h>
 #include <lib/zx/channel.h>
 #endif
diff --git a/zircon/system/ulib/devmgr-integration-test/launcher.cpp b/zircon/system/ulib/devmgr-integration-test/launcher.cpp
index 2d2d745d67cd43e6a886bb8c22df1b7dec4e6893..ea49a7f1ed17c480876af9bc0c69b5edb876dfda 100644
--- a/zircon/system/ulib/devmgr-integration-test/launcher.cpp
+++ b/zircon/system/ulib/devmgr-integration-test/launcher.cpp
@@ -9,7 +9,9 @@
 
 #include <fbl/algorithm.h>
 #include <lib/devmgr-launcher/launch.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <zircon/processargs.h>
 #include <zircon/status.h>
diff --git a/zircon/system/ulib/devmgr-launcher/launcher.cpp b/zircon/system/ulib/devmgr-launcher/launcher.cpp
index 7a3fe3ceafc9bab286c0ae5968fc147cf68791bf..cd1e87fac6bc16cb310f24ff4a3aaa254045f9f9 100644
--- a/zircon/system/ulib/devmgr-launcher/launcher.cpp
+++ b/zircon/system/ulib/devmgr-launcher/launcher.cpp
@@ -10,7 +10,9 @@
 #include <fbl/algorithm.h>
 #include <lib/fdio/namespace.h>
 #include <lib/fdio/spawn.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <lib/zx/process.h>
 #include <zircon/assert.h>
diff --git a/zircon/system/ulib/fdio/bsdsocket.c b/zircon/system/ulib/fdio/bsdsocket.c
index 9a646545a96d972180736caf72f656c9e3b6711f..c4af6c5331bdd9346469bc2d9fb2e6e548403f88 100644
--- a/zircon/system/ulib/fdio/bsdsocket.c
+++ b/zircon/system/ulib/fdio/bsdsocket.c
@@ -22,7 +22,9 @@
 
 #include <lib/fdio/debug.h>
 #include <lib/fdio/io.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zxs/protocol.h>
 #include <lib/zxs/zxs.h>
 
diff --git a/zircon/system/ulib/fdio/namespace/local-filesystem.cpp b/zircon/system/ulib/fdio/namespace/local-filesystem.cpp
index a5f35dd64a7ac8456688b4e37cd23d636f1c2737..7c96d3792eaa61910c47b3f472e65d3e8ff036e0 100644
--- a/zircon/system/ulib/fdio/namespace/local-filesystem.cpp
+++ b/zircon/system/ulib/fdio/namespace/local-filesystem.cpp
@@ -17,7 +17,9 @@
 #include <fbl/string_buffer.h>
 #include <fbl/string_piece.h>
 #include <lib/fdio/namespace.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <zircon/device/vfs.h>
 #include <zircon/processargs.h>
diff --git a/zircon/system/ulib/fdio/namespace/namespace.cpp b/zircon/system/ulib/fdio/namespace/namespace.cpp
index 632ffb42d45681d8c4662070ce77181bbce56096..ddb3a6240be819651f3255ebf5dd181f1637785a 100644
--- a/zircon/system/ulib/fdio/namespace/namespace.cpp
+++ b/zircon/system/ulib/fdio/namespace/namespace.cpp
@@ -8,7 +8,9 @@
 #include <fbl/ref_counted.h>
 #include <fbl/ref_ptr.h>
 #include <lib/fdio/namespace.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <zircon/types.h>
 #include <zircon/processargs.h>
diff --git a/zircon/system/ulib/fdio/remoteio.c b/zircon/system/ulib/fdio/remoteio.c
index 3525df352bb6ece3c7a34d9e9cdc8dad422bfee1..04bf6f55bf1207218c056ee8eefb03c21e68374a 100644
--- a/zircon/system/ulib/fdio/remoteio.c
+++ b/zircon/system/ulib/fdio/remoteio.c
@@ -6,6 +6,9 @@
 #include <fuchsia/io/c/fidl.h>
 #include <lib/fdio/io.h>
 #include <lib/fdio/namespace.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/util.h>
 #include <string.h>
 #include <zircon/device/vfs.h>
diff --git a/zircon/system/ulib/fdio/socket.c b/zircon/system/ulib/fdio/socket.c
index b9ab0fecff562441f862f653c28aeefc4dd74c86..5627bccc0b79ebbf67f99ce65348f8c813394b48 100644
--- a/zircon/system/ulib/fdio/socket.c
+++ b/zircon/system/ulib/fdio/socket.c
@@ -3,7 +3,9 @@
 // found in the LICENSE file.
 
 #include <lib/fdio/io.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zxio/inception.h>
 #include <lib/zxs/protocol.h>
 #include <poll.h>
diff --git a/zircon/system/ulib/fdio/spawn.c b/zircon/system/ulib/fdio/spawn.c
index bccf653d6ee8d910b2701e9bc3dbc26a8342144e..ee51af22838dc251e9b9e84c4f0a5dfb0e74c3fd 100644
--- a/zircon/system/ulib/fdio/spawn.c
+++ b/zircon/system/ulib/fdio/spawn.c
@@ -9,7 +9,9 @@
 #include <lib/fdio/io.h>
 #include <lib/fdio/limits.h>
 #include <lib/fdio/namespace.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <string.h>
diff --git a/zircon/system/ulib/fdio/unistd.c b/zircon/system/ulib/fdio/unistd.c
index f51e0ad8b899a79cccabcbeb58ce93bd08f6d7b0..2a646036fad58627d661114570a97e3c65805c42 100644
--- a/zircon/system/ulib/fdio/unistd.c
+++ b/zircon/system/ulib/fdio/unistd.c
@@ -38,7 +38,9 @@
 #include <lib/fdio/namespace.h>
 #include <lib/fdio/private.h>
 #include <lib/fdio/unsafe.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/vfs.h>
 
 #include "private.h"
diff --git a/zircon/system/ulib/fdio/waitable.cpp b/zircon/system/ulib/fdio/waitable.cpp
index 0e3b5251f29fdb024667f0a6d90a4dde15bdfad6..ce7aba1e49328b1854b519178cbc9e0c6eadf72b 100644
--- a/zircon/system/ulib/fdio/waitable.cpp
+++ b/zircon/system/ulib/fdio/waitable.cpp
@@ -2,7 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zxio/null.h>
 #include <lib/zxio/ops.h>
 #include <string.h>
diff --git a/zircon/system/ulib/fdio/zxio.c b/zircon/system/ulib/fdio/zxio.c
index 9666721162ee41661bb27d91c6c6d2bf09910ca0..3778a47957e59f03c3fbb110f064f3563bd1b31d 100644
--- a/zircon/system/ulib/fdio/zxio.c
+++ b/zircon/system/ulib/fdio/zxio.c
@@ -2,7 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zxio/inception.h>
 #include <lib/zxio/null.h>
 #include <lib/zxio/zxio.h>
diff --git a/zircon/system/ulib/fs-management/fsck.cpp b/zircon/system/ulib/fs-management/fsck.cpp
index bf002bf3cf519228546e8bfd61a024122bd5fe2f..67b6451beca28fe7816ac44da9e0e4dd2d1c640b 100644
--- a/zircon/system/ulib/fs-management/fsck.cpp
+++ b/zircon/system/ulib/fs-management/fsck.cpp
@@ -12,7 +12,9 @@
 
 #include <fbl/unique_ptr.h>
 #include <lib/fdio/limits.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/vfs.h>
 #include <zircon/compiler.h>
 #include <zircon/device/vfs.h>
diff --git a/zircon/system/ulib/fs-management/fvm.cpp b/zircon/system/ulib/fs-management/fvm.cpp
index 6a378ad116c0fa5d982aa96d051fbe36a4333664..bb1e6eaac6aec54375023a6d041705b70c0f7952 100644
--- a/zircon/system/ulib/fs-management/fvm.cpp
+++ b/zircon/system/ulib/fs-management/fvm.cpp
@@ -17,7 +17,9 @@
 #include <fs-management/fvm.h>
 #include <fvm/format.h>
 #include <lib/fdio/limits.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/vfs.h>
 #include <lib/fdio/watcher.h>
 #include <lib/fzl/fdio.h>
diff --git a/zircon/system/ulib/fs-management/launch.cpp b/zircon/system/ulib/fs-management/launch.cpp
index bd7cac125145c8cd81f7c378ac41975bc16bcbca..7ed7536046d62eaccc47dfbdcb7507cfbe99271c 100644
--- a/zircon/system/ulib/fs-management/launch.cpp
+++ b/zircon/system/ulib/fs-management/launch.cpp
@@ -15,7 +15,9 @@
 #include <fs-management/mount.h>
 #include <lib/fdio/io.h>
 #include <lib/fdio/spawn.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/process.h>
 #include <zircon/compiler.h>
 #include <zircon/processargs.h>
diff --git a/zircon/system/ulib/fs-management/mkfs.cpp b/zircon/system/ulib/fs-management/mkfs.cpp
index b954b42ff205462c7ff6398bca3641f0efdd2bef..72fa2032ab7bde28927d86464dd33d3f3c3115d3 100644
--- a/zircon/system/ulib/fs-management/mkfs.cpp
+++ b/zircon/system/ulib/fs-management/mkfs.cpp
@@ -15,7 +15,9 @@
 #include <fbl/unique_ptr.h>
 #include <fbl/vector.h>
 #include <lib/fdio/limits.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/vfs.h>
 #include <zircon/compiler.h>
 #include <zircon/device/vfs.h>
diff --git a/zircon/system/ulib/fs-management/mount.cpp b/zircon/system/ulib/fs-management/mount.cpp
index 3763ec57bead7fcc7103f6956e3127d492bbf1a8..511243f583cff754f610c2b2335c60cd3178cbcb 100644
--- a/zircon/system/ulib/fs-management/mount.cpp
+++ b/zircon/system/ulib/fs-management/mount.cpp
@@ -17,7 +17,9 @@
 #include <fs/client.h>
 #include <fuchsia/io/c/fidl.h>
 #include <lib/fdio/limits.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/vfs.h>
 #include <lib/fzl/fdio.h>
 #include <lib/zx/channel.h>
diff --git a/zircon/system/ulib/inet6/netifc.c b/zircon/system/ulib/inet6/netifc.c
index 4a676e3bcab8c97f4a684abab7756b4d3c043ed0..c6a97aefa5731402b9c689aa77eab04e2cbd7ec6 100644
--- a/zircon/system/ulib/inet6/netifc.c
+++ b/zircon/system/ulib/inet6/netifc.c
@@ -27,7 +27,9 @@
 #include <inet6/netifc.h>
 
 #include <lib/fdio/io.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/watcher.h>
 
 #define ALIGN(n, a) (((n) + ((a) - 1)) & ~((a) - 1))
diff --git a/zircon/system/ulib/launchpad/fdio.c b/zircon/system/ulib/launchpad/fdio.c
index 0eef82270c23a6407d79752e5bfe49efa4364025..48fa18bcfccb6f39e729d28e4b55bd5b859cd415 100644
--- a/zircon/system/ulib/launchpad/fdio.c
+++ b/zircon/system/ulib/launchpad/fdio.c
@@ -10,7 +10,9 @@
 #include <zircon/syscalls.h>
 #include <lib/fdio/io.h>
 #include <lib/fdio/namespace.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 
 #include <stdlib.h>
 #include <unistd.h>
diff --git a/zircon/system/ulib/log/log.cpp b/zircon/system/ulib/log/log.cpp
index b810e978e49da5f193af9dbf3808fbf651103b97..45bc07b578a1f42bf784e20b9505fa123846c07c 100644
--- a/zircon/system/ulib/log/log.cpp
+++ b/zircon/system/ulib/log/log.cpp
@@ -5,7 +5,9 @@
 #include <fbl/algorithm.h>
 #include <fbl/string.h>
 #include <fbl/vector.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/log/log.h>
 #include <lib/log/log_writer.h>
 #include <memory>
diff --git a/zircon/system/ulib/ramdevice-client/ramdisk.cpp b/zircon/system/ulib/ramdevice-client/ramdisk.cpp
index e8af2334fc8d436ff385a109763f225989dcefa9..62ae9d99280ed5cb32e2a95d0c7ab95f74e69793 100644
--- a/zircon/system/ulib/ramdevice-client/ramdisk.cpp
+++ b/zircon/system/ulib/ramdevice-client/ramdisk.cpp
@@ -22,7 +22,9 @@
 #include <fbl/unique_fd.h>
 #include <fuchsia/device/c/fidl.h>
 #include <fuchsia/hardware/ramdisk/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/watcher.h>
 #include <lib/zx/channel.h>
 #include <lib/zx/time.h>
diff --git a/zircon/system/ulib/ramdevice-client/ramnand.cpp b/zircon/system/ulib/ramdevice-client/ramnand.cpp
index a237e2bd6d08cc9d17210294d9dee65f6e4ba2e7..3f74b1b1e80402fea5a776182c2036069edb96d7 100644
--- a/zircon/system/ulib/ramdevice-client/ramnand.cpp
+++ b/zircon/system/ulib/ramdevice-client/ramnand.cpp
@@ -14,7 +14,9 @@
 #include <fbl/unique_fd.h>
 #include <fuchsia/device/c/fidl.h>
 #include <fuchsia/hardware/nand/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fzl/fdio.h>
 #include <zircon/types.h>
 
diff --git a/zircon/system/ulib/runtests-utils/log-exporter.cpp b/zircon/system/ulib/runtests-utils/log-exporter.cpp
index 781d30ffb0219292960e9b6f531198a97e991272..d0ef6bee6654c518bd7dec0955ca4129ea670919 100644
--- a/zircon/system/ulib/runtests-utils/log-exporter.cpp
+++ b/zircon/system/ulib/runtests-utils/log-exporter.cpp
@@ -8,7 +8,9 @@
 #include <stdint.h>
 
 #include <fuchsia/logger/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fidl/cpp/message_buffer.h>
 #include <lib/zx/channel.h>
 #include <zircon/status.h>
diff --git a/zircon/system/ulib/syslog/logger.cpp b/zircon/system/ulib/syslog/logger.cpp
index 523fad6065b9b6968eaa056d3f57a251d1d88a21..534f555ef12e27e6795605f4ec950a4bd38695f3 100644
--- a/zircon/system/ulib/syslog/logger.cpp
+++ b/zircon/system/ulib/syslog/logger.cpp
@@ -2,7 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <lib/zx/socket.h>
 #include <lib/syslog/logger.h>
diff --git a/zircon/system/ulib/sysmem-connector/sysmem-connector.cpp b/zircon/system/ulib/sysmem-connector/sysmem-connector.cpp
index e572566506c4ba8bac779a4ffcd277aca42bdb80..f61ecf88b1797b62035e1889fd425559b57b2378 100644
--- a/zircon/system/ulib/sysmem-connector/sysmem-connector.cpp
+++ b/zircon/system/ulib/sysmem-connector/sysmem-connector.cpp
@@ -12,7 +12,9 @@
 #include <lib/async/cpp/task.h>
 #include <lib/async-loop/cpp/loop.h>
 #include <lib/fdio/watcher.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fzl/fdio.h>
 #include <lib/zx/channel.h>
 
diff --git a/zircon/system/ulib/task-utils/walker.cpp b/zircon/system/ulib/task-utils/walker.cpp
index e76229bf26993491c5fa4e049af3a0e32f9f8230..3a2cf12215d0bee0a5e8002f1dd4235fbef3879c 100644
--- a/zircon/system/ulib/task-utils/walker.cpp
+++ b/zircon/system/ulib/task-utils/walker.cpp
@@ -12,7 +12,9 @@
 #include <unistd.h>
 
 #include <fuchsia/sysinfo/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <zircon/status.h>
 #include <zircon/syscalls.h>
diff --git a/zircon/system/ulib/tee-client-api/tee-client-api.c b/zircon/system/ulib/tee-client-api/tee-client-api.c
index 94ac5f4db28d86a9a26bb98f9e37597de398a27e..4e6f3623ca17ebaaa417a4c5980d3c045efea343 100644
--- a/zircon/system/ulib/tee-client-api/tee-client-api.c
+++ b/zircon/system/ulib/tee-client-api/tee-client-api.c
@@ -12,7 +12,9 @@
 #include <zircon/syscalls.h>
 
 #include <fuchsia/hardware/tee/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 
 #include <tee-client-api/tee_client_api.h>
 
diff --git a/zircon/system/ulib/trace-provider/fdio_connect.cpp b/zircon/system/ulib/trace-provider/fdio_connect.cpp
index 2411ee94534004619801a5195f86ea12f1855754..d1033d755f574c3850a91ab7a3d6af4e752d385d 100644
--- a/zircon/system/ulib/trace-provider/fdio_connect.cpp
+++ b/zircon/system/ulib/trace-provider/fdio_connect.cpp
@@ -4,7 +4,9 @@
 
 // A helper library for connecting to the trace manager via fdio.
 
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <trace-provider/fdio_connect.h>
 
diff --git a/zircon/system/utest/chromeos-disk-setup/chromeos-disk-setup.cpp b/zircon/system/utest/chromeos-disk-setup/chromeos-disk-setup.cpp
index be4cdac041e744f3840dce51b2385b605f64c3e2..d4c7e42640b8e986ed6f28170062d3c93c50d4ab 100644
--- a/zircon/system/utest/chromeos-disk-setup/chromeos-disk-setup.cpp
+++ b/zircon/system/utest/chromeos-disk-setup/chromeos-disk-setup.cpp
@@ -11,7 +11,9 @@
 #include <unistd.h>
 
 #include <fbl/unique_fd.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/vmo.h>
 #include <zircon/device/block.h>
 #include <zircon/syscalls.h>
diff --git a/zircon/system/utest/devfs/fdio-tests.cpp b/zircon/system/utest/devfs/fdio-tests.cpp
index 5513b357ebf87e3a8196f48fc79c2ac8ba775b0a..5190c0b5f61fad51d10d62e467f02ccda6628294 100644
--- a/zircon/system/utest/devfs/fdio-tests.cpp
+++ b/zircon/system/utest/devfs/fdio-tests.cpp
@@ -8,7 +8,9 @@
 #include <fbl/unique_fd.h>
 #include <fuchsia/io/c/fidl.h>
 #include <lib/fdio/limits.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <unittest/unittest.h>
 #include <zircon/processargs.h>
 #include <zircon/syscalls.h>
diff --git a/zircon/system/utest/devfs/fidl-tests.cpp b/zircon/system/utest/devfs/fidl-tests.cpp
index a59db22b8f4e3df0f223891c4b7fd3c1875449cf..64d09fc69a3f3729fe490cf0ff9881cb3823855e 100644
--- a/zircon/system/utest/devfs/fidl-tests.cpp
+++ b/zircon/system/utest/devfs/fidl-tests.cpp
@@ -6,7 +6,9 @@
 #include <fs/connection.h>
 #include <fuchsia/io/c/fidl.h>
 #include <lib/fdio/namespace.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <unittest/unittest.h>
 #include <zircon/device/vfs.h>
diff --git a/zircon/system/utest/device-enumeration/main.cpp b/zircon/system/utest/device-enumeration/main.cpp
index e95130a297fb5d46d217d89290aa51ced7135d02..f8243f40692c0dfaad607acf51705401b9c56673 100644
--- a/zircon/system/utest/device-enumeration/main.cpp
+++ b/zircon/system/utest/device-enumeration/main.cpp
@@ -11,7 +11,9 @@
 #include <fbl/unique_fd.h>
 #include <fuchsia/sysinfo/c/fidl.h>
 #include <lib/devmgr-integration-test/fixture.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <unittest/unittest.h>
 #include <zircon/status.h>
 
diff --git a/zircon/system/utest/driver-test/main.cpp b/zircon/system/utest/driver-test/main.cpp
index 39d95e036b0427f752e56490473844241dfcc1c6..6e0ad8a51ecb1c9718b3e45afd35f0a6756e461d 100644
--- a/zircon/system/utest/driver-test/main.cpp
+++ b/zircon/system/utest/driver-test/main.cpp
@@ -17,7 +17,9 @@
 #include <fuchsia/device/c/fidl.h>
 #include <fuchsia/device/test/c/fidl.h>
 #include <lib/devmgr-integration-test/fixture.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <lib/zx/socket.h>
 #include <lib/zx/time.h>
diff --git a/zircon/system/utest/ethernet/ethernet.cpp b/zircon/system/utest/ethernet/ethernet.cpp
index cb2069c2eab786490feb66585d9fe10608ac29a8..b31ab9de1feab55005af0c8125676d031dc0bbfb 100644
--- a/zircon/system/utest/ethernet/ethernet.cpp
+++ b/zircon/system/utest/ethernet/ethernet.cpp
@@ -9,7 +9,9 @@
 #include <fbl/unique_ptr.h>
 #include <fbl/vector.h>
 #include <fuchsia/hardware/ethernet/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fdio/watcher.h>
 #include <lib/fzl/fdio.h>
 #include <lib/fzl/fifo.h>
diff --git a/zircon/system/utest/fdio/fdio_handle_fd.c b/zircon/system/utest/fdio/fdio_handle_fd.c
index 972a46e394c1d7dabe2980c25143cc70fd2501d3..17e76126d2cdb0231585564904096012cf17b58d 100644
--- a/zircon/system/utest/fdio/fdio_handle_fd.c
+++ b/zircon/system/utest/fdio/fdio_handle_fd.c
@@ -14,7 +14,9 @@
 #include <unistd.h>
 
 #include <lib/fdio/io.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <unittest/unittest.h>
 #include <zircon/processargs.h>
 #include <zircon/syscalls.h>
diff --git a/zircon/system/utest/fdio/fdio_socket.c b/zircon/system/utest/fdio/fdio_socket.c
index b226a12be4231daf419c546d7ae492e43cdb6d67..f56c1b40c81e420242daefd631e0d3e4761b8447 100644
--- a/zircon/system/utest/fdio/fdio_socket.c
+++ b/zircon/system/utest/fdio/fdio_socket.c
@@ -6,7 +6,9 @@
 #include <sys/socket.h>
 #include <unistd.h>
 
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <unittest/unittest.h>
 #include <zircon/processargs.h>
 #include <zircon/syscalls.h>
diff --git a/zircon/system/utest/fdio/fdio_socketpair.c b/zircon/system/utest/fdio/fdio_socketpair.c
index d1dac6dc4edec2fc079c647f16b42d133ffdecae..0fc195b2d04b31e93864761588e6e5ee5d194b7b 100644
--- a/zircon/system/utest/fdio/fdio_socketpair.c
+++ b/zircon/system/utest/fdio/fdio_socketpair.c
@@ -14,7 +14,9 @@
 
 #include <lib/fdio/limits.h>
 #include <lib/fdio/unsafe.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <zircon/processargs.h>
 #include <zircon/syscalls.h>
 
diff --git a/zircon/system/utest/fs-vnode/service-tests.cpp b/zircon/system/utest/fs-vnode/service-tests.cpp
index d7407a9e5a82e4423c09b5cbc6ba1dd8e1f6d016..ca546f9f6714dc4a8ef7cd1b6d762bd6a8885def 100644
--- a/zircon/system/utest/fs-vnode/service-tests.cpp
+++ b/zircon/system/utest/fs-vnode/service-tests.cpp
@@ -3,7 +3,9 @@
 // found in the LICENSE file.
 
 #include <lib/async-loop/cpp/loop.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <fs/synchronous-vfs.h>
 #include <fs/pseudo-dir.h>
 #include <fs/service.h>
diff --git a/zircon/system/utest/fs/test-access.cpp b/zircon/system/utest/fs/test-access.cpp
index 338a7cdacdf36309010307dcdaf2f4afb0cb76eb..663d29a35f62f8e8893725b1b9b47124712aa7ea 100644
--- a/zircon/system/utest/fs/test-access.cpp
+++ b/zircon/system/utest/fs/test-access.cpp
@@ -13,7 +13,9 @@
 #include <unistd.h>
 
 #include <lib/fdio/limits.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <unittest/unittest.h>
 #include <zircon/syscalls.h>
 
diff --git a/zircon/system/utest/fs/test-append.cpp b/zircon/system/utest/fs/test-append.cpp
index 16ef138ec4d097cb2dfdddcdeb370d00505eef6a..ff4869eecf5cd1eb76a3fa60da4d5b351d802264 100644
--- a/zircon/system/utest/fs/test-append.cpp
+++ b/zircon/system/utest/fs/test-append.cpp
@@ -14,7 +14,9 @@
 #include <fbl/algorithm.h>
 #include <fbl/unique_fd.h>
 #include <lib/fdio/limits.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 
 #include "filesystems.h"
 #include "misc.h"
diff --git a/zircon/system/utest/fs/test-basic.c b/zircon/system/utest/fs/test-basic.c
index 65d5c616891796c843f444a5972fcab6055a7e7c..6753df92972e4ab99c77a3741abb92e3a3d11ff6 100644
--- a/zircon/system/utest/fs/test-basic.c
+++ b/zircon/system/utest/fs/test-basic.c
@@ -10,7 +10,9 @@
 #include <unistd.h>
 
 #include <lib/fdio/limits.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <unittest/unittest.h>
 #include <zircon/syscalls.h>
 
diff --git a/zircon/system/utest/fs/test-clone.cpp b/zircon/system/utest/fs/test-clone.cpp
index 8780ec9e2690ce254f24213128cadcef3f7c62ef..6da8d499d1f74fd3c6178603754689f66ee58b90 100644
--- a/zircon/system/utest/fs/test-clone.cpp
+++ b/zircon/system/utest/fs/test-clone.cpp
@@ -11,7 +11,9 @@
 #include <unistd.h>
 
 #include <lib/fdio/limits.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <unittest/unittest.h>
 #include <zircon/syscalls.h>
 
diff --git a/zircon/system/utest/hypervisor/guest.cpp b/zircon/system/utest/hypervisor/guest.cpp
index ab6cda97f0c844a67a09ff956660e2468366bc99..5e1933273d720e481c0df6a74e1d780acd3801b3 100644
--- a/zircon/system/utest/hypervisor/guest.cpp
+++ b/zircon/system/utest/hypervisor/guest.cpp
@@ -8,7 +8,9 @@
 
 #include <fbl/unique_fd.h>
 #include <fuchsia/sysinfo/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <lib/zx/guest.h>
 #include <lib/zx/port.h>
diff --git a/zircon/system/utest/kernel-unittests/kernel-unittests.cpp b/zircon/system/utest/kernel-unittests/kernel-unittests.cpp
index d93e162fccc963d87b77a203ef6367bbf035728d..320618f6b935bbdd04662f4ac68e191ed0b35752 100644
--- a/zircon/system/utest/kernel-unittests/kernel-unittests.cpp
+++ b/zircon/system/utest/kernel-unittests/kernel-unittests.cpp
@@ -6,7 +6,9 @@
 #include <unistd.h>
 
 #include <fuchsia/kernel/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <unittest/unittest.h>
 #include <zircon/syscalls.h>
diff --git a/zircon/system/utest/launchpad/launchpad.cpp b/zircon/system/utest/launchpad/launchpad.cpp
index c46060a7e775404160432648cfdb5689e6f782d6..bc15cdbdf471ba16368dcb080f7505668aee5d69 100644
--- a/zircon/system/utest/launchpad/launchpad.cpp
+++ b/zircon/system/utest/launchpad/launchpad.cpp
@@ -20,7 +20,9 @@
 #include <fbl/array.h>
 #include <fbl/auto_call.h>
 
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/handle.h>
 #include <lib/zx/vmo.h>
 
diff --git a/zircon/system/utest/memfs/fidl-tests.cpp b/zircon/system/utest/memfs/fidl-tests.cpp
index 1830bc2933772ea5cb8c894671ccc9895bcf1068..124d027fcff418ff633f5d6833389a31230193aa 100644
--- a/zircon/system/utest/memfs/fidl-tests.cpp
+++ b/zircon/system/utest/memfs/fidl-tests.cpp
@@ -14,7 +14,9 @@
 #include <fbl/unique_fd.h>
 #include <fuchsia/io/c/fidl.h>
 #include <lib/async-loop/cpp/loop.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fzl/fdio.h>
 #include <lib/memfs/memfs.h>
 #include <unittest/unittest.h>
diff --git a/zircon/system/utest/memfs/memfs-tests.cpp b/zircon/system/utest/memfs/memfs-tests.cpp
index 587f10600026ddc3890b808c132ee03beed08169..e94d24b56dbd28a3c3124471bae795291febaf37 100644
--- a/zircon/system/utest/memfs/memfs-tests.cpp
+++ b/zircon/system/utest/memfs/memfs-tests.cpp
@@ -14,7 +14,9 @@
 #include <fbl/unique_ptr.h>
 #include <fbl/unique_fd.h>
 #include <fbl/vector.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/async-loop/cpp/loop.h>
 #include <lib/memfs/memfs.h>
 #include <unittest/unittest.h>
diff --git a/zircon/system/utest/memfs/vmofile-tests.cpp b/zircon/system/utest/memfs/vmofile-tests.cpp
index f01c3db73a3ae1a0796d7f3392c69b24fc80df89..b9d255cd9020c75b74bfbd4fb662f813d2030146 100644
--- a/zircon/system/utest/memfs/vmofile-tests.cpp
+++ b/zircon/system/utest/memfs/vmofile-tests.cpp
@@ -13,7 +13,9 @@
 #include <fbl/unique_fd.h>
 #include <fuchsia/io/c/fidl.h>
 #include <lib/async-loop/cpp/loop.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/memfs/cpp/vnode.h>
 #include <lib/memfs/memfs.h>
 #include <lib/zx/channel.h>
diff --git a/zircon/system/utest/profile/profile.cpp b/zircon/system/utest/profile/profile.cpp
index b713fbb4561f6fb3fc070a70fa64a9a897afd37b..8c6b518f8bb9b9a5c29ce78d8906e1167d2ab05f 100644
--- a/zircon/system/utest/profile/profile.cpp
+++ b/zircon/system/utest/profile/profile.cpp
@@ -7,7 +7,9 @@
 #include <stdio.h>
 
 #include <lib/fdio/io.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 
 #include <unittest/unittest.h>
 
diff --git a/zircon/system/utest/property/property.c b/zircon/system/utest/property/property.c
index 632f5b8e90d0685dc2acad5ecd6831c5154bfbb0..5112031efd428de5a0dbd47db83eb2435b5630bd 100644
--- a/zircon/system/utest/property/property.c
+++ b/zircon/system/utest/property/property.c
@@ -9,7 +9,9 @@
 #include <string.h>
 #include <threads.h>
 
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <test-utils/test-utils.h>
 #include <unittest/unittest.h>
 #include <zircon/compiler.h>
diff --git a/zircon/system/utest/spawn/child.c b/zircon/system/utest/spawn/child.c
index eda8586abbaf1efef076794a8de8b3c540f4bf93..f2a83b87e1ce1c996368639cb90278d34656528f 100644
--- a/zircon/system/utest/spawn/child.c
+++ b/zircon/system/utest/spawn/child.c
@@ -6,7 +6,9 @@
 #include <lib/fdio/limits.h>
 #include <lib/fdio/namespace.h>
 #include <lib/fdio/spawn.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
diff --git a/zircon/system/utest/spawn/spawn.cpp b/zircon/system/utest/spawn/spawn.cpp
index 03996bf575e972b7db2d60d0c6da99bc44a4ac8b..6190501a377a772883c8a7f9d2a16894fe64c113 100644
--- a/zircon/system/utest/spawn/spawn.cpp
+++ b/zircon/system/utest/spawn/spawn.cpp
@@ -7,7 +7,9 @@
 #include <fcntl.h>
 #include <lib/fdio/io.h>
 #include <lib/fdio/spawn.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <lib/zx/job.h>
 #include <lib/zx/process.h>
diff --git a/zircon/system/utest/stdio/stdio.c b/zircon/system/utest/stdio/stdio.c
index 229872fe98735aa9ff29224a1d61de2ed6c882a1..33bfc3dc243ae91fd382f9110a1bf80ff43b0373 100644
--- a/zircon/system/utest/stdio/stdio.c
+++ b/zircon/system/utest/stdio/stdio.c
@@ -20,7 +20,9 @@
 #include <zircon/syscalls.h>
 #include <zircon/syscalls/object.h>
 
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 
 #include <unittest/unittest.h>
 
diff --git a/zircon/system/utest/sysinfo/main.cpp b/zircon/system/utest/sysinfo/main.cpp
index c76b25622e8182aa7eb49651f4f4cb419705bc98..6bf706c8a2a87e0759b7d7aa37cfbcd97825d60a 100644
--- a/zircon/system/utest/sysinfo/main.cpp
+++ b/zircon/system/utest/sysinfo/main.cpp
@@ -6,7 +6,9 @@
 #include <unistd.h>
 
 #include <fuchsia/sysinfo/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <zircon/boot/image.h>
 #include <zircon/syscalls.h>
diff --git a/zircon/system/utest/sysmem/sysmem_tests.cpp b/zircon/system/utest/sysmem/sysmem_tests.cpp
index 01cf4c365ae3259e4d2807e7c477dea57c851797..ef8d67d434dcde800c1e5016cba41bf74d470dc5 100644
--- a/zircon/system/utest/sysmem/sysmem_tests.cpp
+++ b/zircon/system/utest/sysmem/sysmem_tests.cpp
@@ -7,7 +7,9 @@
 #include <fcntl.h>
 #include <fuchsia/sysmem/c/fidl.h>
 #include <lib/fdio/unsafe.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/fidl-async-2/fidl_struct.h>
 #include <lib/zx/channel.h>
 #include <lib/zx/event.h>
diff --git a/zircon/system/utest/thread-state/thread-state.cpp b/zircon/system/utest/thread-state/thread-state.cpp
index 881cbd680df5e278fb216bef53dd915b5b8f7c67..ceabc672fe12495bdc948a00a9fa0a93df289da9 100644
--- a/zircon/system/utest/thread-state/thread-state.cpp
+++ b/zircon/system/utest/thread-state/thread-state.cpp
@@ -12,7 +12,9 @@
 
 #include <fbl/algorithm.h>
 #include <fuchsia/sysinfo/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <lib/zx/channel.h>
 #include <zircon/process.h>
 #include <zircon/processargs.h>
diff --git a/zircon/system/utest/usb/usb-test.c b/zircon/system/utest/usb/usb-test.c
index 27f8bad564d73bfc0f6a376e8da6d4b078743757..a115cb7165df0b3447f969c63b92873020e723cb 100644
--- a/zircon/system/utest/usb/usb-test.c
+++ b/zircon/system/utest/usb/usb-test.c
@@ -3,7 +3,9 @@
 // found in the LICENSE file.
 
 #include <fuchsia/hardware/usb/tester/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <unittest/unittest.h>
 
 #include <dirent.h>
diff --git a/zircon/system/utest/vdso-base/vdso-base.c b/zircon/system/utest/vdso-base/vdso-base.c
index 1c0ddba74f989fcfc6ea41cc9fefbe2300ddb822..8e60e390b210cc69b1f719f35210d620c3528095 100644
--- a/zircon/system/utest/vdso-base/vdso-base.c
+++ b/zircon/system/utest/vdso-base/vdso-base.c
@@ -8,7 +8,9 @@
 #include <zircon/process.h>
 #include <zircon/processargs.h>
 #include <zircon/syscalls.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/fd.h>
+#include <lib/fdio/fdio.h>
+#include <lib/fdio/directory.h>
 #include <stdio.h>
 #include <sys/param.h>
 #include <string.h>
diff --git a/zircon/third_party/uapp/dash/src/bltin/zircon.c b/zircon/third_party/uapp/dash/src/bltin/zircon.c
index 6aef889064b7c30d3e3a634c7d1dc33c43e444de..3bdb9abbf307361e2253873690da1746f5d67184 100644
--- a/zircon/third_party/uapp/dash/src/bltin/zircon.c
+++ b/zircon/third_party/uapp/dash/src/bltin/zircon.c
@@ -17,7 +17,7 @@
 
 #include <fuchsia/device/manager/c/fidl.h>
 #include <fuchsia/kernel/c/fidl.h>
-#include <lib/fdio/util.h>
+#include <lib/fdio/directory.h>
 #include <pretty/hexdump.h>
 #include <zircon/syscalls.h>