Reimplement efile_drv as a dirty NIF

This improves the latency of file operations as dirty schedulers
are a bit more eager to run jobs than async threads, and use a
single global queue rather than per-thread queues, eliminating the
risk of a job stalling behind a long-running job on the same thread
while other async threads sit idle.

There's no such thing as a free lunch though; the lowered latency
comes at the cost of increased busy-waiting which may have an
adverse effect on some applications. This behavior can be tweaked
with the +sbwt flag, but unfortunately it affects all types of
schedulers and not just dirty ones. We plan to add type-specific
flags at a later stage.

sendfile has been moved to inet_drv to lessen the effect of a nasty
race; the cooperation between inet_drv and efile has never been
airtight and the socket dying at the wrong time (Regardless of
reason) could result in fd aliasing. Moving it to the inet driver
makes it impossible to trigger this by closing the socket in the
middle of a sendfile operation, while still allowing it to be
aborted -- something that can't be done if it stays in the file
driver.

The race still occurs if the controlling process dies in the short
window between dispatching the sendfile operation and the dup(2)
call in the driver, but it's much less likely to happen now.

A proper fix is in the works.

--

Notable functional differences:

* The use_threads option for file:sendfile/5 no longer has any
  effect.

* The file-specific DTrace probes have been removed. The same
  effect can be achieved with normal tracing together with the
  nif__entry/nif__return probes to track scheduling.

--

OTP-14256

bootstrap/lib/kernel/ebin/kernel.app

@@ -88,6 +88,13 @@
              inet_udp,
 	     inet_sctp,
              pg2,
+             raw_file_io,
+             raw_file_io_compressed,
+             raw_file_io_deflate,
+             raw_file_io_delayed,
+             raw_file_io_inflate,
+             raw_file_io_list,
+             raw_file_io_raw,
 	     seq_trace,
 	     standard_error,
 	     wrap_log_reader]},

erts/emulator/Makefile.in

@@ -634,6 +634,7 @@ GENERATE += $(TTF_DIR)/driver_tab.c
 PRELOAD_BEAM =		$(ERL_TOP)/erts/preloaded/ebin/otp_ring0.beam \
 			$(ERL_TOP)/erts/preloaded/ebin/erts_code_purger.beam \
 			$(ERL_TOP)/erts/preloaded/ebin/init.beam \
+			$(ERL_TOP)/erts/preloaded/ebin/prim_buffer.beam \
 			$(ERL_TOP)/erts/preloaded/ebin/prim_eval.beam \
 			$(ERL_TOP)/erts/preloaded/ebin/prim_inet.beam \
 			$(ERL_TOP)/erts/preloaded/ebin/prim_file.beam \
@@ -644,8 +645,7 @@ PRELOAD_BEAM =		$(ERL_TOP)/erts/preloaded/ebin/otp_ring0.beam \
 			$(ERL_TOP)/erts/preloaded/ebin/erts_internal.beam \
 			$(ERL_TOP)/erts/preloaded/ebin/erl_tracer.beam \
 			$(ERL_TOP)/erts/preloaded/ebin/erts_literal_area_collector.beam \
-			$(ERL_TOP)/erts/preloaded/ebin/erts_dirty_process_code_checker.beam \
-			$(ERL_TOP)/erts/preloaded/ebin/prim_buffer.beam
+			$(ERL_TOP)/erts/preloaded/ebin/erts_dirty_process_code_checker.beam
 
 ifeq ($(TARGET),win32)
 # On windows the preloaded objects are in a resource object.
@@ -786,6 +786,9 @@ $(OBJDIR)/%.o: drivers/$(ERLANG_OSTYPE)/%.c
 $(OBJDIR)/%.o: nifs/common/%.c
 	$(V_CC) $(CFLAGS) -DLIBSCTP=$(LIBSCTP) $(INCLUDES) -Inifs/common -Inifs/$(ERLANG_OSTYPE) -c $< -o $@
 
+$(OBJDIR)/%.o: nifs/$(ERLANG_OSTYPE)/%.c
+	$(V_CC) $(CFLAGS) $(INCLUDES) -Inifs/common -Inifs/$(ERLANG_OSTYPE) -I../etc/$(ERLANG_OSTYPE) -c $< -o $@
+
 # ----------------------------------------------------------------------
 # Specials
 #
@@ -874,18 +877,17 @@ RUN_OBJS += \
 LTTNG_OBJS = $(OBJDIR)/erlang_lttng.o
 NIF_OBJS = \
 	   $(OBJDIR)/erl_tracer_nif.o \
-	   $(OBJDIR)/zlib_nif.o \
-	   $(OBJDIR)/prim_buffer_nif.o
+	   $(OBJDIR)/prim_buffer_nif.o \
+	   $(OBJDIR)/prim_file_nif.o \
+	   $(OBJDIR)/zlib_nif.o
 
 ifeq ($(TARGET),win32)
 DRV_OBJS = \
 	$(OBJDIR)/registry_drv.o \
-	$(OBJDIR)/efile_drv.o \
 	$(OBJDIR)/inet_drv.o \
 	$(OBJDIR)/ram_file_drv.o \
 	$(OBJDIR)/ttsl_drv.o
 OS_OBJS = \
-	$(OBJDIR)/win_efile.o \
 	$(OBJDIR)/win_con.o \
 	$(OBJDIR)/dll_sys.o \
 	$(OBJDIR)/driver_tab.o \
@@ -894,22 +896,22 @@ OS_OBJS = \
 	$(OBJDIR)/sys_time.o \
 	$(OBJDIR)/sys_interrupt.o \
 	$(OBJDIR)/sys_env.o \
-	$(OBJDIR)/dosmap.o
+	$(OBJDIR)/dosmap.o \
+	$(OBJDIR)/win_prim_file.o
 
 else
 OS_OBJS = \
 	$(OBJDIR)/sys.o \
 	$(OBJDIR)/sys_drivers.o \
 	$(OBJDIR)/sys_uds.o \
 	$(OBJDIR)/driver_tab.o \
-	$(OBJDIR)/unix_efile.o \
+	$(OBJDIR)/elib_memmove.o \
 	$(OBJDIR)/gzio.o \
-	$(OBJDIR)/elib_memmove.o
+	$(OBJDIR)/unix_prim_file.o
 
 	OS_OBJS += $(OBJDIR)/sys_float.o \
                    $(OBJDIR)/sys_time.o
 DRV_OBJS = \
-	$(OBJDIR)/efile_drv.o \
 	$(OBJDIR)/inet_drv.o \
 	$(OBJDIR)/ram_file_drv.o \
 	$(OBJDIR)/ttsl_drv.o
@@ -1137,6 +1139,7 @@ BEAM_SRC=$(wildcard beam/*.c)
 DRV_COMMON_SRC=$(wildcard drivers/common/*.c)
 DRV_OSTYPE_SRC=$(wildcard drivers/$(ERLANG_OSTYPE)/*.c)
 NIF_COMMON_SRC=$(wildcard nifs/common/*.c)
+NIF_OSTYPE_SRC=$(wildcard nifs/$(ERLANG_OSTYPE)/*.c)
 ALL_SYS_SRC=$(wildcard sys/$(ERLANG_OSTYPE)/*.c) $(wildcard sys/common/*.c)
 # We use $(shell ls) here instead of wildcard as $(wildcard ) resolved at
 # loadtime of the makefile and at that time these files are not generated yet.
@@ -1149,7 +1152,10 @@ ifeq ($(TARGET),win32)
 
 #DEP_CC=$(EMU_CC)
 DEP_CC=$(CC)
-DEP_FLAGS=-MM  $(subst -O2,,$(CFLAGS)) $(INCLUDES) -I../etc/win32 -Idrivers/common -Idrivers/$(ERLANG_OSTYPE)
+DEP_FLAGS=-MM  $(subst -O2,,$(CFLAGS)) $(INCLUDES) -I../etc/win32 \
+	-Idrivers/common -Idrivers/$(ERLANG_OSTYPE) \
+	-Inifs/common -Inifs/$(ERLANG_OSTYPE)
+
 # ifeq (@MIXED_CYGWIN_VC@,yes)
 # VC++ used for compiling. If __GNUC__ is defined we will include
 # other headers then when compiling which will result in faulty
@@ -1169,7 +1175,9 @@ MG_FLAG=-MG
 endif
 
 DEP_CC=$(CC)
-DEP_FLAGS=-MM $(MG_FLAG) $(CFLAGS) $(INCLUDES) -Inifs/common -Idrivers/common -Idrivers/$(ERLANG_OSTYPE)
+DEP_FLAGS=-MM $(MG_FLAG) $(CFLAGS) $(INCLUDES) \
+	-Idrivers/common -Idrivers/$(ERLANG_OSTYPE) \
+	-Inifs/common -Inifs/$(ERLANG_OSTYPE)
 SYS_SRC=$(ALL_SYS_SRC)
 endif
 
@@ -1200,6 +1208,8 @@ $(TTF_DIR)/depend.mk: $(TTF_DIR)/GENERATED $(PRELOAD_SRC)
 		| $(SED_DEPEND) >> $(TTF_DIR)/depend.mk
 	$(V_at)$(DEP_CC) $(DEP_FLAGS) $(NIF_COMMON_SRC) \
 		| $(SED_DEPEND) >> $(TTF_DIR)/depend.mk
+	$(V_at)$(DEP_CC) $(DEP_FLAGS) -I../etc/$(ERLANG_OSTYPE) $(NIF_OSTYPE_SRC) \
+		| $(SED_DEPEND) >> $(TTF_DIR)/depend.mk
 	$(V_at)$(DEP_CC) $(DEP_FLAGS) $(SYS_SRC) \
 		| $(SED_DEPEND) >> $(TTF_DIR)/depend.mk
 	$(V_at)$(DEP_CC) $(DEP_FLAGS) $(TARGET_SRC) \

erts/emulator/beam/erl_lock_check.c

@@ -109,7 +109,6 @@ static erts_lc_lock_order_t erts_lock_order[] = {
     {	"fun_tab",				NULL			},
     {	"environ",				NULL			},
     {	"release_literal_areas",		NULL			},
-    {	"efile_drv",				"address"		},
     {	"drv_ev_state_grow",			NULL,   		},
     {	"drv_ev_state",				"address"		},
     {	"safe_hash",				"address"		},
@@ -169,9 +168,6 @@ static erts_lc_lock_order_t erts_lock_order[] = {
 #ifdef DEBUG
     {   "save_ops_lock",                        NULL                    },
 #endif
-#endif
-#ifdef	USE_VM_PROBES
-    {   "efile_drv dtrace mutex",               NULL                    },
 #endif
     {	"mtrace_buf",				NULL			},
     {	"os_monotonic_time",			NULL			},