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

14 files changed, 1265 insertions, 131 deletions

diff --git a/lib/kernel/src/Makefile b/lib/kernel/src/Makefile
index 5946620f0f..4a713b2a99 100644
--- a/lib/kernel/src/Makefile
+++ b/lib/kernel/src/Makefile
@@ -120,6 +120,13 @@ MODULES = \
 	user \
 	user_drv \
 	user_sup \
+	raw_file_io \
+	raw_file_io_compressed \
+	raw_file_io_inflate \
+	raw_file_io_deflate \
+	raw_file_io_delayed \
+	raw_file_io_list \
+	raw_file_io_raw \
 	wrap_log_reader
 
 HRL_FILES= ../include/file.hrl ../include/inet.hrl ../include/inet_sctp.hrl \
@@ -226,7 +233,8 @@ $(EBIN)/disk_log_server.beam: disk_log.hrl
 $(EBIN)/dist_util.beam: ../include/dist_util.hrl ../include/dist.hrl
 $(EBIN)/erl_boot_server.beam: inet_boot.hrl
 $(EBIN)/erl_epmd.beam: inet_int.hrl erl_epmd.hrl
-$(EBIN)/file.beam: ../include/file.hrl
+$(EBIN)/file.beam: ../include/file.hrl file_int.hrl
+$(EBIN)/file_io_server.beam: ../include/file.hrl file_int.hrl
 $(EBIN)/gen_tcp.beam: inet_int.hrl
 $(EBIN)/gen_udp.beam: inet_int.hrl
 $(EBIN)/gen_sctp.beam: ../include/inet_sctp.hrl
@@ -254,3 +262,10 @@ $(EBIN)/net_kernel.beam: ../include/net_address.hrl
 $(EBIN)/os.beam: ../include/file.hrl
 $(EBIN)/ram_file.beam: ../include/file.hrl
 $(EBIN)/wrap_log_reader.beam: disk_log.hrl ../include/file.hrl
+$(EBIN)/raw_file_io.beam: ../include/file.hrl file_int.hrl
+$(EBIN)/raw_file_io_compressed.beam: ../include/file.hrl file_int.hrl
+$(EBIN)/raw_file_io_inflate.beam: ../include/file.hrl file_int.hrl
+$(EBIN)/raw_file_io_deflate.beam: ../include/file.hrl file_int.hrl
+$(EBIN)/raw_file_io_delayed.beam: ../include/file.hrl file_int.hrl
+$(EBIN)/raw_file_io_list.beam: ../include/file.hrl file_int.hrl
+$(EBIN)/raw_file_io_raw.beam: ../include/file.hrl file_int.hrl
diff --git a/lib/kernel/src/file.erl b/lib/kernel/src/file.erl
index 933f2d5f65..b5a51c3410 100644
--- a/lib/kernel/src/file.erl
+++ b/lib/kernel/src/file.erl
@@ -72,7 +72,7 @@
               io_device/0, name/0, name_all/0, posix/0]).
 
 %%% Includes and defines
--include("file.hrl").
+-include("file_int.hrl").
 
 -define(FILE_IO_SERVER_TABLE, file_io_servers).
 
@@ -454,41 +454,23 @@ raw_write_file_info(Name, #file_info{} = Info) ->
       Reason :: posix() | badarg | system_limit.
 
 open(Item, ModeList) when is_list(ModeList) ->
-    case lists:member(raw, ModeList) of
-	%% Raw file, use ?PRIM_FILE to handle this file
-	true ->
+    case {lists:member(raw, ModeList), lists:member(ram, ModeList)} of
+        {false, false} ->
+            %% File server file
             Args = [file_name(Item) | ModeList],
             case check_args(Args) of
                 ok ->
                     [FileName | _] = Args,
-                    %% We rely on the returned Handle (in {ok, Handle})
-                    %% being a pid() or a #file_descriptor{}
-                    ?PRIM_FILE:open(FileName, ModeList);
+                    call(open, [FileName, ModeList]);
                 Error ->
                     Error
-	    end;
-	false ->
-	    case lists:member(ram, ModeList) of
-		%% RAM file, use ?RAM_FILE to handle this file
-		true ->
-		    case check_args(ModeList) of
-			ok ->
-			    ?RAM_FILE:open(Item, ModeList);
-			Error ->
-			    Error
-		    end;
-		%% File server file
-		false ->
-		    Args = [file_name(Item) | ModeList],
-		    case check_args(Args) of 
-			ok ->
-			    [FileName | _] = Args,
-			    call(open, [FileName, ModeList]);
-			Error ->
-			    Error
-		    end
-	    end
+            end;
+        {true, _Either} ->
+            raw_file_io:open(file_name(Item), ModeList);
+        {false, true} ->
+            ram_file:open(Item, ModeList)
     end;
+
 %% Old obsolete mode specification in atom or 2-tuple format
 open(Item, Mode) ->
     open(Item, mode_list(Mode)).
diff --git a/lib/kernel/src/file_int.hrl b/lib/kernel/src/file_int.hrl
new file mode 100644
index 0000000000..bafc330c04
--- /dev/null
+++ b/lib/kernel/src/file_int.hrl
@@ -0,0 +1,33 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2017. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+
+%%
+%% Internal definitions for the 'file' module and friends.
+%%
+
+-ifndef(FILE_INTERNAL_HRL_).
+-define(FILE_INTERNAL_HRL_, 1).
+
+-include("file.hrl").
+
+-define(CALL_FD(Fd, Method, Args),
+    apply(Fd#file_descriptor.module, Method, [Fd | Args])).
+
+-endif.
diff --git a/lib/kernel/src/file_io_server.erl b/lib/kernel/src/file_io_server.erl
index deb7b315b1..2b35d2acfb 100644
--- a/lib/kernel/src/file_io_server.erl
+++ b/lib/kernel/src/file_io_server.erl
@@ -1,7 +1,7 @@
 %%
 %% %CopyrightBegin%
 %%
-%% Copyright Ericsson AB 2000-2015. All Rights Reserved.
+%% Copyright Ericsson AB 2000-2017. All Rights Reserved.
 %%
 %% Licensed under the Apache License, Version 2.0 (the "License");
 %% you may not use this file except in compliance with the License.
@@ -28,7 +28,8 @@
 
 -record(state, {handle,owner,mref,buf,read_mode,unic}).
 
--define(PRIM_FILE, prim_file).
+-include("file_int.hrl").
+
 -define(READ_SIZE_LIST, 128).
 -define(READ_SIZE_BINARY, (8*1024)).
 
@@ -68,7 +69,7 @@ do_start(Spawn, Owner, FileName, ModeList) ->
 		  %% process_flag(trap_exit, true),
 		  case parse_options(ModeList) of
 		      {ReadMode, UnicodeMode, Opts} ->
-			  case ?PRIM_FILE:open(FileName, Opts) of
+			  case raw_file_io:open(FileName, [raw | Opts]) of
 			      {error, Reason} = Error ->
 				  Self ! {Ref, Error},
 				  exit(Reason);
@@ -205,7 +206,7 @@ io_reply(From, ReplyAs, Reply) ->
 
 file_request({advise,Offset,Length,Advise},
          #state{handle=Handle}=State) ->
-    case ?PRIM_FILE:advise(Handle, Offset, Length, Advise) of
+    case ?CALL_FD(Handle, advise, [Offset, Length, Advise]) of
     {error,Reason}=Reply ->
         {stop,Reason,Reply,State};
     Reply ->
@@ -213,7 +214,7 @@ file_request({advise,Offset,Length,Advise},
     end;
 file_request({allocate, Offset, Length},
          #state{handle = Handle} = State) ->
-    Reply = ?PRIM_FILE:allocate(Handle, Offset, Length),
+    Reply = ?CALL_FD(Handle, allocate, [Offset, Length]),
     {reply, Reply, State};
 file_request({pread,At,Sz}, State)
   when At =:= cur;
@@ -256,7 +257,7 @@ file_request({pwrite,At,Data},
     end;
 file_request(datasync,
 	     #state{handle=Handle}=State) ->
-    case ?PRIM_FILE:datasync(Handle) of
+    case ?CALL_FD(Handle, datasync, []) of
 	{error,Reason}=Reply ->
 	    {stop,Reason,Reply,State};
 	Reply ->
@@ -264,7 +265,7 @@ file_request(datasync,
     end;
 file_request(sync, 
 	     #state{handle=Handle}=State) ->
-    case ?PRIM_FILE:sync(Handle) of
+    case ?CALL_FD(Handle, sync, []) of
 	{error,Reason}=Reply ->
 	    {stop,Reason,Reply,State};
 	Reply ->
@@ -272,7 +273,7 @@ file_request(sync,
     end;
 file_request(close, 
 	     #state{handle=Handle}=State) ->
-    case ?PRIM_FILE:close(Handle) of
+    case ?CALL_FD(Handle, close, []) of
 	{error,Reason}=Reply ->
 	    {stop,Reason,Reply,State#state{buf= <<>>}};
 	Reply ->
@@ -288,7 +289,7 @@ file_request({position,At},
     end;
 file_request(truncate, 
 	     #state{handle=Handle}=State) ->
-    case ?PRIM_FILE:truncate(Handle) of
+    case ?CALL_FD(Handle, truncate, []) of
 	{error,Reason}=Reply ->
 	    {stop,Reason,Reply,State#state{buf= <<>>}};
 	Reply ->
@@ -398,7 +399,7 @@ io_request_loop([Request|Tail],
 %%
 put_chars(Chars, latin1, #state{handle=Handle, unic=latin1}=State) ->
     NewState = State#state{buf = <<>>},
-    case ?PRIM_FILE:write(Handle, Chars) of
+    case ?CALL_FD(Handle, write, [Chars]) of
 	{error,Reason}=Reply ->
 	    {stop,Reason,Reply,NewState};
 	Reply ->
@@ -408,7 +409,7 @@ put_chars(Chars, InEncoding, #state{handle=Handle, unic=OutEncoding}=State) ->
     NewState = State#state{buf = <<>>},
     case unicode:characters_to_binary(Chars,InEncoding,OutEncoding) of
 	Bin when is_binary(Bin) ->
-	    case ?PRIM_FILE:write(Handle, Bin) of
+	    case ?CALL_FD(Handle, write, [Bin]) of
 		{error,Reason}=Reply ->
 		    {stop,Reason,Reply,NewState};
 		Reply ->
@@ -422,7 +423,7 @@ put_chars(Chars, InEncoding, #state{handle=Handle, unic=OutEncoding}=State) ->
 
 get_line(S, {<<>>, Cont}, OutEnc,
 	 #state{handle=Handle, read_mode=Mode, unic=InEnc}=State) ->
-    case ?PRIM_FILE:read(Handle, read_size(Mode)) of
+    case ?CALL_FD(Handle, read, [read_size(Mode)]) of
 	{ok,Bin} ->
 	    get_line(S, convert_enc([Cont, Bin], InEnc, OutEnc), OutEnc, State);
 	eof ->
@@ -472,7 +473,7 @@ get_chars(N, OutEnc,#state{handle=Handle,buf=Buf,read_mode=ReadMode,unic=latin1}
     BufSize = byte_size(Buf),
     NeedSize = N-BufSize,
     Size = erlang:max(NeedSize, ?READ_SIZE_BINARY),
-    case ?PRIM_FILE:read(Handle, Size) of
+    case ?CALL_FD(Handle, read, [Size]) of
 	{ok, B} ->
 	    if BufSize+byte_size(B) < N ->
 		    std_reply(cat(Buf, B, ReadMode,latin1,OutEnc), State);
@@ -504,7 +505,7 @@ get_chars(N, OutEnc,#state{handle=Handle,buf=Buf,read_mode=ReadMode,unic=InEncod
 		%% Need more, Try to read 4*needed in bytes...
 		NeedSize = (N - BufCount) * 4,
 		Size = erlang:max(NeedSize, ?READ_SIZE_BINARY),
-		case ?PRIM_FILE:read(Handle, Size) of
+		case ?CALL_FD(Handle, read, [Size]) of
 		    {ok, B} ->
 			NewBuf = list_to_binary([Buf,B]),
 			{NewCount,NewSplit} = count_and_find(NewBuf,N,InEncoding),
@@ -544,7 +545,7 @@ get_chars(Mod, Func, XtraArg, OutEnc, #state{buf=Buf}=State) ->
 
 get_chars_empty(Mod, Func, XtraArg, S, latin1,
 		#state{handle=Handle,read_mode=ReadMode, unic=latin1}=State) ->
-    case ?PRIM_FILE:read(Handle, read_size(ReadMode)) of
+    case ?CALL_FD(Handle, read, [read_size(ReadMode)]) of
 	{ok,Bin} ->
 	    get_chars_apply(Mod, Func, XtraArg, S, latin1, State, Bin);
 	eof ->
@@ -554,7 +555,7 @@ get_chars_empty(Mod, Func, XtraArg, S, latin1,
     end;
 get_chars_empty(Mod, Func, XtraArg, S, OutEnc,
 		#state{handle=Handle,read_mode=ReadMode}=State) ->
-    case ?PRIM_FILE:read(Handle, read_size(ReadMode)) of
+    case ?CALL_FD(Handle, read, [read_size(ReadMode)]) of
 	{ok,Bin} ->
 	    get_chars_apply(Mod, Func, XtraArg, S, OutEnc, State, Bin);
 	eof ->
@@ -564,7 +565,7 @@ get_chars_empty(Mod, Func, XtraArg, S, OutEnc,
     end.
 get_chars_notempty(Mod, Func, XtraArg, S, OutEnc,
 		   #state{handle=Handle,read_mode=ReadMode,buf = B}=State) ->
-    case ?PRIM_FILE:read(Handle, read_size(ReadMode)) of
+    case ?CALL_FD(Handle, read, [read_size(ReadMode)]) of
 	{ok,Bin} ->
 	    get_chars_apply(Mod, Func, XtraArg, S, OutEnc, State, list_to_binary([B,Bin]));
 	eof ->
@@ -918,13 +919,10 @@ cbv({utf32,little},_) ->
 %% Compensates ?PRIM_FILE:position/2 for the number of bytes 
 %% we have buffered
 position(Handle, At, Buf) ->
-    ?PRIM_FILE:position(
-       Handle,
-       case At of
-	   cur ->
-	       {cur, -byte_size(Buf)};
-	   {cur, Offs} ->
-	       {cur, Offs-byte_size(Buf)};
-	   _ ->
-	       At
-       end).
+    SeekTo =
+        case At of
+            {cur, Offs} -> {cur, Offs-byte_size(Buf)};
+            cur -> {cur, -byte_size(Buf)};
+            _ -> At
+        end,
+    ?CALL_FD(Handle, position, [SeekTo]).
diff --git a/lib/kernel/src/file_server.erl b/lib/kernel/src/file_server.erl
index 6e8f64d932..ecc1ffbdd6 100644
--- a/lib/kernel/src/file_server.erl
+++ b/lib/kernel/src/file_server.erl
@@ -63,7 +63,7 @@ stop() ->
 %%% Callback functions from gen_server
 %%%----------------------------------------------------------------------
 
--type state() :: port().	% Internal type
+-type state() :: term().	% Internal type
 
 %%----------------------------------------------------------------------
 %% Func: init/1
@@ -77,14 +77,8 @@ stop() ->
 
 init([]) ->
     process_flag(trap_exit, true),
-    case ?PRIM_FILE:start() of
-	{ok, Handle} ->
-	    ?FILE_IO_SERVER_TABLE =
-                ets:new(?FILE_IO_SERVER_TABLE, [named_table]),
-	    {ok, Handle};
-	{error, Reason} ->
-	    {stop, Reason}
-    end.
+    ?FILE_IO_SERVER_TABLE =  ets:new(?FILE_IO_SERVER_TABLE, [named_table]),
+    {ok, undefined}.
 
 %%----------------------------------------------------------------------
 %% Func: handle_call/3
@@ -101,7 +95,7 @@ init([]) ->
 	{'reply', 'eof' | 'ok' | {'error', term()} | {'ok', term()}, state()} |
 	{'stop', 'normal', 'stopped', state()}.
 
-handle_call({open, Name, ModeList}, {Pid, _Tag} = _From, Handle)
+handle_call({open, Name, ModeList}, {Pid, _Tag} = _From, State)
   when is_list(ModeList) ->
     Child = ?FILE_IO_SERVER:start_link(Pid, Name, ModeList),
     case Child of
@@ -110,78 +104,78 @@ handle_call({open, Name, ModeList}, {Pid, _Tag} = _From, Handle)
 	_ ->
 	    ok
     end,
-    {reply, Child, Handle};
+    {reply, Child, State};
 
-handle_call({open, _Name, _Mode}, _From, Handle) ->
-    {reply, {error, einval}, Handle};
+handle_call({open, _Name, _Mode}, _From, State) ->
+    {reply, {error, einval}, State};
 
-handle_call({read_file, Name}, _From, Handle) ->
-    {reply, ?PRIM_FILE:read_file(Name), Handle};
+handle_call({read_file, Name}, _From, State) ->
+    {reply, ?PRIM_FILE:read_file(Name), State};
 
-handle_call({write_file, Name, Bin}, _From, Handle) ->
-    {reply, ?PRIM_FILE:write_file(Name, Bin), Handle};
+handle_call({write_file, Name, Bin}, _From, State) ->
+    {reply, ?PRIM_FILE:write_file(Name, Bin), State};
 
-handle_call({set_cwd, Name}, _From, Handle) ->
-    {reply, ?PRIM_FILE:set_cwd(Handle, Name), Handle};
+handle_call({set_cwd, Name}, _From, State) ->
+    {reply, ?PRIM_FILE:set_cwd(Name), State};
 
-handle_call({delete, Name}, _From, Handle) ->
-    {reply, ?PRIM_FILE:delete(Handle, Name), Handle};
+handle_call({delete, Name}, _From, State) ->
+    {reply, ?PRIM_FILE:delete(Name), State};
 
-handle_call({rename, Fr, To}, _From, Handle) ->
-    {reply, ?PRIM_FILE:rename(Handle, Fr, To), Handle};
+handle_call({rename, Fr, To}, _From, State) ->
+    {reply, ?PRIM_FILE:rename(Fr, To), State};
 
-handle_call({make_dir, Name}, _From, Handle) ->
-    {reply, ?PRIM_FILE:make_dir(Handle, Name), Handle};
+handle_call({make_dir, Name}, _From, State) ->
+    {reply, ?PRIM_FILE:make_dir(Name), State};
 
-handle_call({del_dir, Name}, _From, Handle) ->
-    {reply, ?PRIM_FILE:del_dir(Handle, Name), Handle};
+handle_call({del_dir, Name}, _From, State) ->
+    {reply, ?PRIM_FILE:del_dir(Name), State};
 
-handle_call({list_dir, Name}, _From, Handle) ->
-    {reply, ?PRIM_FILE:list_dir(Handle, Name), Handle};
-handle_call({list_dir_all, Name}, _From, Handle) ->
-    {reply, ?PRIM_FILE:list_dir_all(Handle, Name), Handle};
+handle_call({list_dir, Name}, _From, State) ->
+    {reply, ?PRIM_FILE:list_dir(Name), State};
+handle_call({list_dir_all, Name}, _From, State) ->
+    {reply, ?PRIM_FILE:list_dir_all(Name), State};
 
-handle_call(get_cwd, _From, Handle) ->
-    {reply, ?PRIM_FILE:get_cwd(Handle), Handle};
-handle_call({get_cwd}, _From, Handle) ->
-    {reply, ?PRIM_FILE:get_cwd(Handle), Handle};
-handle_call({get_cwd, Name}, _From, Handle) ->
-    {reply, ?PRIM_FILE:get_cwd(Handle, Name), Handle};
+handle_call(get_cwd, _From, State) ->
+    {reply, ?PRIM_FILE:get_cwd(), State};
+handle_call({get_cwd}, _From, State) ->
+    {reply, ?PRIM_FILE:get_cwd(), State};
+handle_call({get_cwd, Name}, _From, State) ->
+    {reply, ?PRIM_FILE:get_cwd(Name), State};
 
-handle_call({read_file_info, Name}, _From, Handle) ->
-    {reply, ?PRIM_FILE:read_file_info(Handle, Name), Handle};
+handle_call({read_file_info, Name}, _From, State) ->
+    {reply, ?PRIM_FILE:read_file_info(Name), State};
 
-handle_call({read_file_info, Name, Opts}, _From, Handle) ->
-    {reply, ?PRIM_FILE:read_file_info(Handle, Name, Opts), Handle};
+handle_call({read_file_info, Name, Opts}, _From, State) ->
+    {reply, ?PRIM_FILE:read_file_info(Name, Opts), State};
 
-handle_call({altname, Name}, _From, Handle) ->
-    {reply, ?PRIM_FILE:altname(Handle, Name), Handle};
+handle_call({altname, Name}, _From, State) ->
+    {reply, ?PRIM_FILE:altname(Name), State};
 
-handle_call({write_file_info, Name, Info}, _From, Handle) ->
-    {reply, ?PRIM_FILE:write_file_info(Handle, Name, Info), Handle};
+handle_call({write_file_info, Name, Info}, _From, State) ->
+    {reply, ?PRIM_FILE:write_file_info(Name, Info), State};
 
-handle_call({write_file_info, Name, Info, Opts}, _From, Handle) ->
-    {reply, ?PRIM_FILE:write_file_info(Handle, Name, Info, Opts), Handle};
+handle_call({write_file_info, Name, Info, Opts}, _From, State) ->
+    {reply, ?PRIM_FILE:write_file_info(Name, Info, Opts), State};
 
-handle_call({read_link_info, Name}, _From, Handle) ->
-    {reply, ?PRIM_FILE:read_link_info(Handle, Name), Handle};
+handle_call({read_link_info, Name}, _From, State) ->
+    {reply, ?PRIM_FILE:read_link_info(Name), State};
 
-handle_call({read_link_info, Name, Opts}, _From, Handle) ->
-    {reply, ?PRIM_FILE:read_link_info(Handle, Name, Opts), Handle};
+handle_call({read_link_info, Name, Opts}, _From, State) ->
+    {reply, ?PRIM_FILE:read_link_info(Name, Opts), State};
 
-handle_call({read_link, Name}, _From, Handle) ->
-    {reply, ?PRIM_FILE:read_link(Handle, Name), Handle};
-handle_call({read_link_all, Name}, _From, Handle) ->
-    {reply, ?PRIM_FILE:read_link_all(Handle, Name), Handle};
+handle_call({read_link, Name}, _From, State) ->
+    {reply, ?PRIM_FILE:read_link(Name), State};
+handle_call({read_link_all, Name}, _From, State) ->
+    {reply, ?PRIM_FILE:read_link_all(Name), State};
 
-handle_call({make_link, Old, New}, _From, Handle) ->
-    {reply, ?PRIM_FILE:make_link(Handle, Old, New), Handle};
+handle_call({make_link, Old, New}, _From, State) ->
+    {reply, ?PRIM_FILE:make_link(Old, New), State};
 
-handle_call({make_symlink, Old, New}, _From, Handle) ->
-    {reply, ?PRIM_FILE:make_symlink(Handle, Old, New), Handle};
+handle_call({make_symlink, Old, New}, _From, State) ->
+    {reply, ?PRIM_FILE:make_symlink(Old, New), State};
 
 handle_call({copy, SourceName, SourceOpts, DestName, DestOpts, Length},
-	    _From, Handle) ->
+	    _From, State) ->
     Reply = 
 	case ?PRIM_FILE:open(SourceName, [read, binary | SourceOpts]) of
 	    {ok, Source} ->
@@ -201,14 +195,14 @@ handle_call({copy, SourceName, SourceOpts, DestName, DestOpts, Length},
 	    {error, _} = Error ->
 		Error
 	end,
-    {reply, Reply, Handle};
+    {reply, Reply, State};
 
-handle_call(stop, _From, Handle) ->
-    {stop, normal, stopped, Handle};
+handle_call(stop, _From, State) ->
+    {stop, normal, stopped, State};
 
-handle_call(Request, From, Handle) ->
+handle_call(Request, From, State) ->
     error_logger:error_msg("handle_call(~tp, ~tp, _)", [Request, From]),
-    {noreply, Handle}.
+    {noreply, State}.
 
 %%----------------------------------------------------------------------
 %% Func: handle_cast/2
@@ -233,14 +227,9 @@ handle_cast(Msg, State) ->
 -spec handle_info(term(), state()) ->
         {'noreply', state()} | {'stop', 'normal', state()}.
 
-handle_info({'EXIT', Pid, _Reason}, Handle) when is_pid(Pid) ->
+handle_info({'EXIT', Pid, _Reason}, State) when is_pid(Pid) ->
     ets:delete(?FILE_IO_SERVER_TABLE, Pid),
-    {noreply, Handle};
-
-handle_info({'EXIT', Handle, _Reason}, Handle) ->
-    error_logger:error_msg("Port controlling ~w terminated in ~w",
-			   [?FILE_SERVER, ?MODULE]),
-    {stop, normal, Handle};
+    {noreply, State};
 
 handle_info(Info, State) ->
     error_logger:error_msg("handle_Info(~tp, _)", [Info]),
@@ -254,8 +243,8 @@ handle_info(Info, State) ->
 
 -spec terminate(term(), state()) -> 'ok'.
 
-terminate(_Reason, Handle) ->
-    ?PRIM_FILE:stop(Handle).
+terminate(_Reason, _State) ->
+    ok.
 
 %%----------------------------------------------------------------------
 %% Func: code_change/3
diff --git a/lib/kernel/src/inet_int.hrl b/lib/kernel/src/inet_int.hrl
index bc5b67f7bf..357e27826c 100644
--- a/lib/kernel/src/inet_int.hrl
+++ b/lib/kernel/src/inet_int.hrl
@@ -100,6 +100,8 @@
 -define(TCP_REQ_RECV,           42).
 -define(TCP_REQ_UNRECV,         43).
 -define(TCP_REQ_SHUTDOWN,       44).
+-define(TCP_REQ_SENDFILE,       45).
+
 %% UDP and SCTP requests
 -define(PACKET_REQ_RECV,        60).
 %%-define(SCTP_REQ_LISTEN,        61). MERGED
@@ -319,6 +321,12 @@
 	[((X) bsr 24) band 16#ff, ((X) bsr 16) band 16#ff,
 	 ((X) bsr 8) band 16#ff, (X) band 16#ff]).
 
+-define(int64(X),
+	[((X) bsr 56) band 16#ff, ((X) bsr 48) band 16#ff,
+	 ((X) bsr 40) band 16#ff, ((X) bsr 32) band 16#ff,
+	 ((X) bsr 24) band 16#ff, ((X) bsr 16) band 16#ff,
+	 ((X) bsr 8) band 16#ff, (X) band 16#ff]).
+
 -define(intAID(X), % For SCTP AssocID
         ?int32(X)).
 
diff --git a/lib/kernel/src/kernel.app.src b/lib/kernel/src/kernel.app.src
index 080b11fc4d..e4852a6e75 100644
--- a/lib/kernel/src/kernel.app.src
+++ b/lib/kernel/src/kernel.app.src
@@ -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]},
diff --git a/lib/kernel/src/raw_file_io.erl b/lib/kernel/src/raw_file_io.erl
new file mode 100644
index 0000000000..e3c07c8f78
--- /dev/null
+++ b/lib/kernel/src/raw_file_io.erl
@@ -0,0 +1,75 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2017. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+-module(raw_file_io).
+
+-export([open/2]).
+
+open(Filename, Modes) ->
+    %% Layers are applied in this order, and the listed modules will call this
+    %% function again as necessary. eg. a raw compressed delayed file in list
+    %% mode will walk through [_list -> _compressed -> _delayed -> _raw].
+    ModuleOrder = [{raw_file_io_list, fun match_list/1},
+                   {raw_file_io_compressed, fun match_compressed/1},
+                   {raw_file_io_delayed, fun match_delayed/1},
+                   {raw_file_io_raw, fun match_raw/1}],
+    open_1(ModuleOrder, Filename, add_implicit_modes(Modes)).
+open_1([], _Filename, _Modes) ->
+    error(badarg);
+open_1([{Module, Match} | Rest], Filename, Modes) ->
+    case lists:any(Match, Modes) of
+        true ->
+            {Options, ChildModes} =
+                lists:partition(fun(Mode) -> Match(Mode) end, Modes),
+            Module:open_layer(Filename, ChildModes, Options);
+        false ->
+            open_1(Rest, Filename, Modes)
+    end.
+
+%% 'read' and 'list' mode are enabled unless disabled by another option, so
+%% we'll explicitly add them to avoid duplicating this logic in child layers.
+add_implicit_modes(Modes0) ->
+    Modes1 = add_unless_matched(Modes0, fun match_writable/1, read),
+    add_unless_matched(Modes1, fun match_binary/1, list).
+add_unless_matched(Modes, Match, Default) ->
+    case lists:any(Match, Modes) of
+        false -> [Default | Modes];
+        true -> Modes
+    end.
+
+match_list(list) -> true;
+match_list(_Other) -> false.
+
+match_compressed(compressed) -> true;
+match_compressed(_Other) -> false.
+
+match_delayed({delayed_write, _Size, _Timeout}) -> true;
+match_delayed(delayed_write) -> true;
+match_delayed(_Other) -> false.
+
+match_raw(raw) -> true;
+match_raw(_Other) -> false.
+
+match_writable(write) -> true;
+match_writable(append) -> true;
+match_writable(exclusive) -> true;
+match_writable(_Other) -> false.
+
+match_binary(binary) -> true;
+match_binary(_Other) -> false.
diff --git a/lib/kernel/src/raw_file_io_compressed.erl b/lib/kernel/src/raw_file_io_compressed.erl
new file mode 100644
index 0000000000..d5ab042d25
--- /dev/null
+++ b/lib/kernel/src/raw_file_io_compressed.erl
@@ -0,0 +1,134 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2017. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+-module(raw_file_io_compressed).
+
+-export([close/1, sync/1, datasync/1, truncate/1, advise/4, allocate/3,
+         position/2, write/2, pwrite/2, pwrite/3,
+         read_line/1, read/2, pread/2, pread/3]).
+
+%% OTP internal.
+-export([ipread_s32bu_p32bu/3, sendfile/8]).
+
+-export([open_layer/3]).
+
+-include("file_int.hrl").
+
+open_layer(Filename, Modes, Options) ->
+    IsAppend = lists:member(append, Modes),
+    IsDeflate = lists:member(write, Modes),
+    IsInflate = lists:member(read, Modes),
+    if
+        IsDeflate, IsInflate; IsAppend ->
+            {error, einval};
+        IsDeflate, not IsInflate ->
+            start_server_module(raw_file_io_deflate, Filename, Modes, Options);
+        IsInflate ->
+            start_server_module(raw_file_io_inflate, Filename, Modes, Options)
+    end.
+
+start_server_module(Module, Filename, Modes, Options) ->
+    Secret = make_ref(),
+    case gen_statem:start(Module, {self(), Secret, Options}, []) of
+        {ok, Pid} -> open_next_layer(Pid, Secret, Filename, Modes);
+        Other -> Other
+    end.
+
+open_next_layer(Pid, Secret, Filename, Modes) ->
+    case gen_statem:call(Pid, {'$open', Secret, Filename, Modes}, infinity) of
+        ok ->
+            PublicFd = #file_descriptor{
+                module = raw_file_io_compressed, data = {self(), Pid} },
+            {ok, PublicFd};
+        Other -> Other
+    end.
+
+close(Fd) ->
+    wrap_call(Fd, [close]).
+
+sync(Fd) ->
+    wrap_call(Fd, [sync]).
+datasync(Fd) ->
+    wrap_call(Fd, [datasync]).
+
+truncate(Fd) ->
+    wrap_call(Fd, [truncate]).
+
+advise(Fd, Offset, Length, Advise) ->
+    wrap_call(Fd, [advise, Offset, Length, Advise]).
+allocate(Fd, Offset, Length) ->
+    wrap_call(Fd, [allocate, Offset, Length]).
+
+position(Fd, Mark) ->
+    wrap_call(Fd, [position, Mark]).
+
+write(Fd, IOData) ->
+    try
+        CompactedData = erlang:iolist_to_iovec(IOData),
+        wrap_call(Fd, [write, CompactedData])
+    catch
+        error:badarg -> {error, badarg}
+    end.
+
+pwrite(Fd, Offset, IOData) ->
+    try
+        CompactedData = erlang:iolist_to_iovec(IOData),
+        wrap_call(Fd, [pwrite, Offset, CompactedData])
+    catch
+        error:badarg -> {error, badarg}
+    end.
+pwrite(Fd, LocBytes) ->
+    try
+        CompactedLocBytes =
+            [ {Offset, erlang:iolist_to_iovec(IOData)} ||
+              {Offset, IOData} <- LocBytes ],
+        wrap_call(Fd, [pwrite, CompactedLocBytes])
+    catch
+        error:badarg -> {error, badarg}
+    end.
+
+read_line(Fd) ->
+    wrap_call(Fd, [read_line]).
+read(Fd, Size) ->
+    wrap_call(Fd, [read, Size]).
+pread(Fd, Offset, Size) ->
+    wrap_call(Fd, [pread, Offset, Size]).
+pread(Fd, LocNums) ->
+    wrap_call(Fd, [pread, LocNums]).
+
+ipread_s32bu_p32bu(Fd, Offset, MaxSize) ->
+    wrap_call(Fd, [ipread_s32bu_p32bu, Offset, MaxSize]).
+
+sendfile(_,_,_,_,_,_,_,_) ->
+    {error, enotsup}.
+
+wrap_call(Fd, Command) ->
+    {_Owner, Pid} = get_fd_data(Fd),
+    try gen_statem:call(Pid, Command, infinity) of
+        Result -> Result
+    catch
+        exit:{noproc, _StackTrace} -> {error, einval}
+    end.
+
+get_fd_data(#file_descriptor{ data = Data }) ->
+    {Owner, _ServerPid} = Data,
+    case self() of
+        Owner -> Data;
+        _ -> error(not_on_controlling_process)
+    end.
diff --git a/lib/kernel/src/raw_file_io_deflate.erl b/lib/kernel/src/raw_file_io_deflate.erl
new file mode 100644
index 0000000000..acfc546743
--- /dev/null
+++ b/lib/kernel/src/raw_file_io_deflate.erl
@@ -0,0 +1,159 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2017. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+-module(raw_file_io_deflate).
+
+-behavior(gen_statem).
+
+-export([init/1, callback_mode/0, terminate/3]).
+-export([opening/3, opened/3]).
+
+-include("file_int.hrl").
+
+-define(GZIP_WBITS, 16 + 15).
+
+callback_mode() -> state_functions.
+
+init({Owner, Secret, [compressed]}) ->
+    Monitor = monitor(process, Owner),
+    Z = zlib:open(),
+    ok = zlib:deflateInit(Z, default, deflated, ?GZIP_WBITS, 8, default),
+    Data =
+        #{ owner => Owner,
+           monitor => Monitor,
+           secret => Secret,
+           position => 0,
+           zlib => Z },
+    {ok, opening, Data}.
+
+opening({call, From}, {'$open', Secret, Filename, Modes}, #{ secret := Secret } = Data) ->
+    case raw_file_io:open(Filename, Modes) of
+        {ok, PrivateFd} ->
+            NewData = Data#{ handle => PrivateFd },
+            {next_state, opened, NewData, [{reply, From, ok}]};
+        Other ->
+            {stop_and_reply, normal, [{reply, From, Other}]}
+    end;
+opening(_Event, _Contents, _Data) ->
+    {keep_state_and_data, [postpone]}.
+
+%%
+
+opened(info, {'DOWN', Monitor, process, _Owner, Reason}, #{ monitor := Monitor } = Data) ->
+    if
+        Reason =/= kill -> flush_deflate_state(Data);
+        Reason =:= kill -> ignored
+    end,
+    {stop, shutdown};
+
+opened(info, _Message, _Data) ->
+    keep_state_and_data;
+
+opened({call, {Owner, _Tag} = From}, [close], #{ owner := Owner } = Data) ->
+    #{ handle := PrivateFd } = Data,
+    Response =
+        case flush_deflate_state(Data) of
+            ok -> ?CALL_FD(PrivateFd, close, []);
+            Other -> Other
+        end,
+    {stop_and_reply, normal, [{reply, From, Response}]};
+
+opened({call, {Owner, _Tag} = From}, [position, Mark], #{ owner := Owner } = Data) ->
+    case position(Data, Mark) of
+        {ok, NewData, Result} ->
+            Response = {ok, Result},
+            {keep_state, NewData, [{reply, From, Response}]};
+        Other ->
+            {keep_state_and_data, [{reply, From, Other}]}
+    end;
+
+opened({call, {Owner, _Tag} = From}, [write, IOVec], #{ owner := Owner } = Data) ->
+    case write(Data, IOVec) of
+        {ok, NewData} -> {keep_state, NewData, [{reply, From, ok}]};
+        Other -> {keep_state_and_data, [{reply, From, Other}]}
+    end;
+
+opened({call, {Owner, _Tag} = From}, [read, _Size], #{ owner := Owner }) ->
+    Response = {error, ebadf},
+    {keep_state_and_data, [{reply, From, Response}]};
+
+opened({call, {Owner, _Tag} = From}, [read_line], #{ owner := Owner }) ->
+    Response = {error, ebadf},
+    {keep_state_and_data, [{reply, From, Response}]};
+
+opened({call, {Owner, _Tag} = From}, _Command, #{ owner := Owner }) ->
+    Response = {error, enotsup},
+    {keep_state_and_data, [{reply, From, Response}]};
+
+opened({call, _From}, _Command, _Data) ->
+    %% The client functions filter this out, so we'll crash if the user does
+    %% anything stupid on purpose.
+    {shutdown, protocol_violation};
+
+opened(_Event, _Request, _Data) ->
+    keep_state_and_data.
+
+write(Data, IOVec) ->
+    #{ handle := PrivateFd, position := Position, zlib := Z } = Data,
+    UncompressedSize = iolist_size(IOVec),
+    case ?CALL_FD(PrivateFd, write, [zlib:deflate(Z, IOVec)]) of
+        ok -> {ok, Data#{ position := (Position + UncompressedSize) }};
+        Other -> Other
+    end.
+
+%%
+%% We support "seeking" forward as long as it isn't relative to EOF.
+%%
+%% Seeking is a bit of a misnomer as it's really just compressing zeroes until
+%% we reach the desired point, but it has always behaved like this.
+%%
+
+position(Data, Mark) when is_atom(Mark) ->
+    position(Data, {Mark, 0});
+position(Data, Offset) when is_integer(Offset) ->
+    position(Data, {bof, Offset});
+position(Data, {bof, Offset}) when is_integer(Offset) ->
+    position_1(Data, Offset);
+position(Data, {cur, Offset}) when is_integer(Offset) ->
+    #{ position := Position } = Data,
+    position_1(Data, Position + Offset);
+position(_Data, {eof, Offset}) when is_integer(Offset) ->
+    {error, einval};
+position(_Data, _Any) ->
+    {error, badarg}.
+
+position_1(#{ position := Desired } = Data, Desired) ->
+    {ok, Data, Desired};
+position_1(#{ position := Current } = Data, Desired) when Current < Desired ->
+    BytesToWrite = min(Desired - Current, 4 bsl 20),
+    case write(Data, <<0:(BytesToWrite)/unit:8>>) of
+        {ok, NewData} -> position_1(NewData, Desired);
+        Other -> Other
+    end;
+position_1(#{ position := Current }, Desired) when Current > Desired ->
+    {error, einval}.
+
+flush_deflate_state(#{ handle := PrivateFd, zlib := Z }) ->
+    case ?CALL_FD(PrivateFd, write, [zlib:deflate(Z, [], finish)]) of
+        ok -> ok;
+        Other -> Other
+    end.
+
+terminate(_Reason, _State, _Data) ->
+    ok.
diff --git a/lib/kernel/src/raw_file_io_delayed.erl b/lib/kernel/src/raw_file_io_delayed.erl
new file mode 100644
index 0000000000..d2ad7550a1
--- /dev/null
+++ b/lib/kernel/src/raw_file_io_delayed.erl
@@ -0,0 +1,320 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2017. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+-module(raw_file_io_delayed).
+
+-behavior(gen_statem).
+
+-export([close/1, sync/1, datasync/1, truncate/1, advise/4, allocate/3,
+         position/2, write/2, pwrite/2, pwrite/3,
+         read_line/1, read/2, pread/2, pread/3]).
+
+%% OTP internal.
+-export([ipread_s32bu_p32bu/3, sendfile/8]).
+
+-export([open_layer/3]).
+
+-export([init/1, callback_mode/0, terminate/3]).
+-export([opening/3, opened/3]).
+
+-include("file_int.hrl").
+
+open_layer(Filename, Modes, Options) ->
+    Secret = make_ref(),
+    case gen_statem:start(?MODULE, {self(), Secret, Options}, []) of
+        {ok, Pid} ->
+            gen_statem:call(Pid, {'$open', Secret, Filename, Modes}, infinity);
+        Other ->
+            Other
+    end.
+
+callback_mode() -> state_functions.
+
+init({Owner, Secret, Options}) ->
+    Monitor = monitor(process, Owner),
+    Defaults =
+        #{ owner => Owner,
+           monitor => Monitor,
+           secret => Secret,
+           timer => none,
+           pid => self(),
+           buffer => prim_buffer:new(),
+           delay_size => 64 bsl 10,
+           delay_time => 2000 },
+    Data = fill_delay_values(Defaults, Options),
+    {ok, opening, Data}.
+
+fill_delay_values(Data, []) ->
+    Data;
+fill_delay_values(Data, [{delayed_write, Size, Time} | Options]) ->
+    fill_delay_values(Data#{ delay_size => Size, delay_time => Time }, Options);
+fill_delay_values(Data, [_ | Options]) ->
+    fill_delay_values(Data, Options).
+
+opening({call, From}, {'$open', Secret, Filename, Modes}, #{ secret := Secret } = Data) ->
+    case raw_file_io:open(Filename, Modes) of
+        {ok, PrivateFd} ->
+            PublicData = maps:with([owner, buffer, delay_size, pid], Data),
+            PublicFd = #file_descriptor{ module = ?MODULE, data = PublicData },
+
+            NewData = Data#{ handle => PrivateFd },
+            Response = {ok, PublicFd},
+            {next_state, opened, NewData, [{reply, From, Response}]};
+        Other ->
+            {stop_and_reply, normal, [{reply, From, Other}]}
+    end;
+opening(_Event, _Contents, _Data) ->
+    {keep_state_and_data, [postpone]}.
+
+%%
+
+opened(info, {'$timed_out', Secret}, #{ secret := Secret } = Data) ->
+    %% If the user writes something at this exact moment, the flush will fail
+    %% and the timer won't reset on the next write since the buffer won't be
+    %% empty (Unless we collided on a flush). We therefore reset the timeout to
+    %% ensure that data won't sit idle for extended periods of time.
+    case try_flush_write_buffer(Data) of
+        busy -> gen_statem:cast(self(), '$reset_timeout');
+        ok -> ok
+    end,
+    {keep_state, Data#{ timer => none }, []};
+
+opened(info, {'DOWN', Monitor, process, _Owner, Reason}, #{ monitor := Monitor } = Data) ->
+    if
+        Reason =/= kill -> try_flush_write_buffer(Data);
+        Reason =:= kill -> ignored
+    end,
+    {stop, shutdown};
+
+opened(info, _Message, _Data) ->
+    keep_state_and_data;
+
+opened({call, {Owner, _Tag} = From}, [close], #{ owner := Owner } = Data) ->
+    case flush_write_buffer(Data) of
+        ok ->
+            #{ handle := PrivateFd } = Data,
+            Response = ?CALL_FD(PrivateFd, close, []),
+            {stop_and_reply, normal, [{reply, From, Response}]};
+        Other ->
+            {stop_and_reply, normal, [{reply, From, Other}]}
+    end;
+
+opened({call, {Owner, _Tag} = From}, '$wait', #{ owner := Owner }) ->
+    %% Used in write/2 to synchronize writes on lock conflicts.
+    {keep_state_and_data, [{reply, From, ok}]};
+
+opened({call, {Owner, _Tag} = From}, '$synchronous_flush', #{ owner := Owner } = Data) ->
+    cancel_flush_timeout(Data),
+    Response = flush_write_buffer(Data),
+    {keep_state_and_data, [{reply, From, Response}]};
+
+opened({call, {Owner, _Tag} = From}, Command, #{ owner := Owner } = Data) ->
+    Response =
+        case flush_write_buffer(Data) of
+            ok -> dispatch_command(Data, Command);
+            Other -> Other
+        end,
+    {keep_state_and_data, [{reply, From, Response}]};
+
+opened({call, _From}, _Command, _Data) ->
+    %% The client functions filter this out, so we'll crash if the user does
+    %% anything stupid on purpose.
+    {shutdown, protocol_violation};
+
+opened(cast, '$reset_timeout', #{ delay_time := Timeout, secret := Secret } = Data) ->
+    cancel_flush_timeout(Data),
+    Timer = erlang:send_after(Timeout, self(), {'$timed_out', Secret}),
+    {keep_state, Data#{ timer => Timer }, []};
+
+opened(cast, _Message, _Data) ->
+    {keep_state_and_data, []}.
+
+dispatch_command(Data, [Function | Args]) ->
+    #{ handle := Handle } = Data,
+    Module = Handle#file_descriptor.module,
+    apply(Module, Function, [Handle | Args]).
+
+cancel_flush_timeout(#{ timer := none }) ->
+    ok;
+cancel_flush_timeout(#{ timer := Timer }) ->
+    _ = erlang:cancel_timer(Timer, [{async, true}]),
+    ok.
+
+try_flush_write_buffer(#{ buffer := Buffer, handle := PrivateFd }) ->
+    case prim_buffer:try_lock(Buffer) of
+        acquired ->
+            flush_write_buffer_1(Buffer, PrivateFd),
+            prim_buffer:unlock(Buffer),
+            ok;
+        busy ->
+            busy
+    end.
+
+%% This is only safe to use when there is no chance of conflict with the owner
+%% process, or in other words, "during synchronous calls outside of the locked
+%% section of write/2"
+flush_write_buffer(#{ buffer := Buffer, handle := PrivateFd }) ->
+    acquired = prim_buffer:try_lock(Buffer),
+    Result = flush_write_buffer_1(Buffer, PrivateFd),
+    prim_buffer:unlock(Buffer),
+    Result.
+
+flush_write_buffer_1(Buffer, PrivateFd) ->
+    case prim_buffer:size(Buffer) of
+        Size when Size > 0 ->
+            ?CALL_FD(PrivateFd, write, [prim_buffer:read_iovec(Buffer, Size)]);
+        0 ->
+            ok
+    end.
+
+terminate(_Reason, _State, _Data) ->
+    ok.
+
+%% Client functions
+
+write(Fd, IOData) ->
+    try
+        enqueue_write(Fd, erlang:iolist_to_iovec(IOData))
+    catch
+        error:badarg -> {error, badarg}
+    end.
+enqueue_write(_Fd, []) ->
+    ok;
+enqueue_write(Fd, IOVec) ->
+    %% get_fd_data will reject everyone except the process that opened the Fd,
+    %% so we can't race with anyone except the wrapper process.
+    #{ delay_size := DelaySize,
+       buffer := Buffer,
+       pid := Pid } = get_fd_data(Fd),
+    case prim_buffer:try_lock(Buffer) of
+        acquired ->
+            %% (The wrapper process will exit without flushing if we're killed
+            %% while holding the lock).
+            enqueue_write_locked(Pid, Buffer, DelaySize, IOVec);
+        busy ->
+            %% This can only happen while we're processing a timeout in the
+            %% wrapper process, so we perform a bogus call to get a completion
+            %% notification before trying again.
+            gen_statem:call(Pid, '$wait'),
+            enqueue_write(Fd, IOVec)
+    end.
+enqueue_write_locked(Pid, Buffer, DelaySize, IOVec) ->
+    %% The synchronous operations (write, forced flush) are safe since we're
+    %% running on the only process that can fill the buffer; a timeout being
+    %% processed just before $synchronous_flush will cause the flush to nop,
+    %% and a timeout sneaking in just before a synchronous write won't do
+    %% anything since the buffer is guaranteed to be empty at that point.
+    BufSize = prim_buffer:size(Buffer),
+    case is_iovec_smaller_than(IOVec, DelaySize - BufSize) of
+        true when BufSize > 0 ->
+            prim_buffer:write(Buffer, IOVec),
+            prim_buffer:unlock(Buffer);
+        true ->
+            prim_buffer:write(Buffer, IOVec),
+            prim_buffer:unlock(Buffer),
+            gen_statem:cast(Pid, '$reset_timeout');
+        false when BufSize > 0 ->
+            prim_buffer:write(Buffer, IOVec),
+            prim_buffer:unlock(Buffer),
+            gen_statem:call(Pid, '$synchronous_flush');
+        false ->
+            prim_buffer:unlock(Buffer),
+            gen_statem:call(Pid, [write, IOVec])
+    end.
+
+%% iolist_size/1 will always look through the entire list to get a precise
+%% amount, which is pretty inefficient since we only need to know whether we've
+%% hit the buffer threshold or not.
+%%
+%% We only handle the binary case since write/2 forcibly translates input to
+%% erlang:iovec().
+is_iovec_smaller_than(IOVec, Max) ->
+    is_iovec_smaller_than_1(IOVec, Max, 0).
+is_iovec_smaller_than_1(_IOVec, Max, Acc) when Acc >= Max ->
+    false;
+is_iovec_smaller_than_1([], _Max, _Acc) ->
+    true;
+is_iovec_smaller_than_1([Binary | Rest], Max, Acc) when is_binary(Binary) ->
+    is_iovec_smaller_than_1(Rest, Max, Acc + byte_size(Binary)).
+
+close(Fd) ->
+    wrap_call(Fd, [close]).
+
+sync(Fd) ->
+    wrap_call(Fd, [sync]).
+datasync(Fd) ->
+    wrap_call(Fd, [datasync]).
+
+truncate(Fd) ->
+    wrap_call(Fd, [truncate]).
+
+advise(Fd, Offset, Length, Advise) ->
+    wrap_call(Fd, [advise, Offset, Length, Advise]).
+allocate(Fd, Offset, Length) ->
+    wrap_call(Fd, [allocate, Offset, Length]).
+
+position(Fd, Mark) ->
+    wrap_call(Fd, [position, Mark]).
+
+pwrite(Fd, Offset, IOData) ->
+    try
+        CompactedData = erlang:iolist_to_iovec(IOData),
+        wrap_call(Fd, [pwrite, Offset, CompactedData])
+    catch
+        error:badarg -> {error, badarg}
+    end.
+pwrite(Fd, LocBytes) ->
+    try
+        CompactedLocBytes =
+            [ {Offset, erlang:iolist_to_iovec(IOData)} ||
+              {Offset, IOData} <- LocBytes ],
+        wrap_call(Fd, [pwrite, CompactedLocBytes])
+    catch
+        error:badarg -> {error, badarg}
+    end.
+
+read_line(Fd) ->
+    wrap_call(Fd, [read_line]).
+read(Fd, Size) ->
+    wrap_call(Fd, [read, Size]).
+pread(Fd, Offset, Size) ->
+    wrap_call(Fd, [pread, Offset, Size]).
+pread(Fd, LocNums) ->
+    wrap_call(Fd, [pread, LocNums]).
+
+ipread_s32bu_p32bu(Fd, Offset, MaxSize) ->
+    wrap_call(Fd, [ipread_s32bu_p32bu, Offset, MaxSize]).
+
+sendfile(_,_,_,_,_,_,_,_) ->
+    {error, enotsup}.
+
+wrap_call(Fd, Command) ->
+    #{ pid := Pid } = get_fd_data(Fd),
+    try gen_statem:call(Pid, Command, infinity) of
+        Result -> Result
+    catch
+        exit:{noproc, _StackTrace} -> {error, einval}
+    end.
+
+get_fd_data(#file_descriptor{ data = Data }) ->
+    #{ owner := Owner } = Data,
+    case self() of
+        Owner -> Data;
+        _ -> error(not_on_controlling_process)
+    end.
diff --git a/lib/kernel/src/raw_file_io_inflate.erl b/lib/kernel/src/raw_file_io_inflate.erl
new file mode 100644
index 0000000000..7e9780310c
--- /dev/null
+++ b/lib/kernel/src/raw_file_io_inflate.erl
@@ -0,0 +1,261 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2017. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+-module(raw_file_io_inflate).
+
+-behavior(gen_statem).
+
+-export([init/1, callback_mode/0, terminate/3]).
+-export([opening/3, opened_gzip/3, opened_passthrough/3]).
+
+-include("file_int.hrl").
+
+-define(INFLATE_CHUNK_SIZE, (1 bsl 10)).
+-define(GZIP_WBITS, (16 + 15)).
+
+callback_mode() -> state_functions.
+
+init({Owner, Secret, [compressed]}) ->
+    Monitor = monitor(process, Owner),
+    %% We're using the undocumented inflateInit/3 to open the stream in
+    %% 'reset mode', which resets the inflate state at the end of every stream,
+    %% allowing us to read concatenated gzip files.
+    Z = zlib:open(),
+    ok = zlib:inflateInit(Z, ?GZIP_WBITS, reset),
+    Data =
+        #{ owner => Owner,
+           monitor => Monitor,
+           secret => Secret,
+           position => 0,
+           buffer => prim_buffer:new(),
+           zlib => Z },
+    {ok, opening, Data}.
+
+%% The old driver fell back to plain reads if the file didn't start with the
+%% magic gzip bytes.
+choose_decompression_state(PrivateFd) ->
+    State =
+        case ?CALL_FD(PrivateFd, read, [2]) of
+            {ok, <<16#1F, 16#8B>>} -> opened_gzip;
+            _Other -> opened_passthrough
+        end,
+    {ok, 0} = ?CALL_FD(PrivateFd, position, [0]),
+    State.
+
+opening({call, From}, {'$open', Secret, Filename, Modes}, #{ secret := Secret } = Data) ->
+    case raw_file_io:open(Filename, Modes) of
+        {ok, PrivateFd} ->
+            NextState = choose_decompression_state(PrivateFd),
+            NewData = Data#{ handle => PrivateFd },
+            {next_state, NextState, NewData, [{reply, From, ok}]};
+        Other ->
+            {stop_and_reply, normal, [{reply, From, Other}]}
+    end;
+opening(_Event, _Contents, _Data) ->
+    {keep_state_and_data, [postpone]}.
+
+internal_close(From, Data) ->
+    #{ handle := PrivateFd } = Data,
+    Response = ?CALL_FD(PrivateFd, close, []),
+    {stop_and_reply, normal, [{reply, From, Response}]}.
+
+opened_passthrough(info, {'DOWN', Monitor, process, _Owner, _Reason}, #{ monitor := Monitor }) ->
+    {stop, shutdown};
+
+opened_passthrough(info, _Message, _Data) ->
+    keep_state_and_data;
+
+opened_passthrough({call, {Owner, _Tag} = From}, [close], #{ owner := Owner } = Data) ->
+    internal_close(From, Data);
+
+opened_passthrough({call, {Owner, _Tag} = From}, [Method | Args], #{ owner := Owner } = Data) ->
+    #{ handle := PrivateFd } = Data,
+    Response = ?CALL_FD(PrivateFd, Method, Args),
+    {keep_state_and_data, [{reply, From, Response}]};
+
+opened_passthrough({call, _From}, _Command, _Data) ->
+    %% The client functions filter this out, so we'll crash if the user does
+    %% anything stupid on purpose.
+    {shutdown, protocol_violation};
+
+opened_passthrough(_Event, _Request, _Data) ->
+    keep_state_and_data.
+
+%%
+
+opened_gzip(info, {'DOWN', Monitor, process, _Owner, _Reason}, #{ monitor := Monitor }) ->
+    {stop, shutdown};
+
+opened_gzip(info, _Message, _Data) ->
+    keep_state_and_data;
+
+opened_gzip({call, {Owner, _Tag} = From}, [close], #{ owner := Owner } = Data) ->
+    internal_close(From, Data);
+
+opened_gzip({call, {Owner, _Tag} = From}, [position, Mark], #{ owner := Owner } = Data) ->
+    case position(Data, Mark) of
+        {ok, NewData, Result} ->
+            Response = {ok, Result},
+            {keep_state, NewData, [{reply, From, Response}]};
+        Other ->
+            {keep_state_and_data, [{reply, From, Other}]}
+    end;
+
+opened_gzip({call, {Owner, _Tag} = From}, [read, Size], #{ owner := Owner } = Data) ->
+    case read(Data, Size) of
+        {ok, NewData, Result} ->
+            Response = {ok, Result},
+            {keep_state, NewData, [{reply, From, Response}]};
+        Other ->
+            {keep_state_and_data, [{reply, From, Other}]}
+    end;
+
+opened_gzip({call, {Owner, _Tag} = From}, [read_line], #{ owner := Owner } = Data) ->
+    case read_line(Data) of
+        {ok, NewData, Result} ->
+            Response = {ok, Result},
+            {keep_state, NewData, [{reply, From, Response}]};
+        Other ->
+            {keep_state_and_data, [{reply, From, Other}]}
+    end;
+
+opened_gzip({call, {Owner, _Tag} = From}, [write, _IOData], #{ owner := Owner }) ->
+    Response = {error, ebadf},
+    {keep_state_and_data, [{reply, From, Response}]};
+
+opened_gzip({call, {Owner, _Tag} = From}, _Request, #{ owner := Owner }) ->
+    Response = {error, enotsup},
+    {keep_state_and_data, [{reply, From, Response}]};
+
+opened_gzip({call, _From}, _Request, _Data) ->
+    %% The client functions filter this out, so we'll crash if the user does
+    %% anything stupid on purpose.
+    {shutdown, protocol_violation};
+
+opened_gzip(_Event, _Request, _Data) ->
+    keep_state_and_data.
+
+%%
+
+read(#{ buffer := Buffer } = Data, Size) ->
+    try read_1(Data, Buffer, prim_buffer:size(Buffer), Size) of
+        Result -> Result
+    catch
+        error:badarg -> {error, badarg};
+        error:_ -> {error, eio}
+    end.
+read_1(Data, Buffer, BufferSize, ReadSize) when BufferSize >= ReadSize ->
+    #{ position := Position } = Data,
+    Decompressed = prim_buffer:read(Buffer, ReadSize),
+    {ok, Data#{ position => (Position + ReadSize) }, Decompressed};
+read_1(Data, Buffer, BufferSize, ReadSize) when BufferSize < ReadSize ->
+    #{ handle := PrivateFd } = Data,
+    case ?CALL_FD(PrivateFd, read, [?INFLATE_CHUNK_SIZE]) of
+        {ok, Compressed} ->
+            #{ zlib := Z } = Data,
+            Uncompressed = erlang:iolist_to_iovec(zlib:inflate(Z, Compressed)),
+            prim_buffer:write(Buffer, Uncompressed),
+            read_1(Data, Buffer, prim_buffer:size(Buffer), ReadSize);
+        eof when BufferSize > 0 ->
+            read_1(Data, Buffer, BufferSize, BufferSize);
+        Other ->
+            Other
+    end.
+
+read_line(#{ buffer := Buffer } = Data) ->
+    try read_line_1(Data, Buffer, prim_buffer:find_byte_index(Buffer, $\n)) of
+        {ok, NewData, Decompressed} -> {ok, NewData, Decompressed};
+        Other -> Other
+    catch
+        error:badarg -> {error, badarg};
+        error:_ -> {error, eio}
+    end.
+
+read_line_1(Data, Buffer, not_found) ->
+    #{ handle := PrivateFd, zlib := Z } = Data,
+    case ?CALL_FD(PrivateFd, read, [?INFLATE_CHUNK_SIZE]) of
+        {ok, Compressed} ->
+            Uncompressed = erlang:iolist_to_iovec(zlib:inflate(Z, Compressed)),
+            prim_buffer:write(Buffer, Uncompressed),
+            read_line_1(Data, Buffer, prim_buffer:find_byte_index(Buffer, $\n));
+        eof ->
+            case prim_buffer:size(Buffer) of
+                Size when Size > 0 -> {ok, prim_buffer:read(Buffer, Size)};
+                Size when Size =:= 0 -> eof
+            end;
+        Error ->
+            Error
+    end;
+read_line_1(Data, Buffer, {ok, LFIndex}) ->
+    %% Translate CRLF into just LF, completely ignoring which encoding is used,
+    %% but treat the file position as including CR.
+    #{ position := Position } = Data,
+    NewData = Data#{ position => (Position + LFIndex + 1) },
+    CRIndex = (LFIndex - 1),
+    TranslatedLine =
+        case prim_buffer:read(Buffer, LFIndex + 1) of
+            <<Line:CRIndex/binary, "\r\n">> -> <<Line/binary, "\n">>;
+            Line -> Line
+        end,
+    {ok, NewData, TranslatedLine}.
+
+%%
+%% We support seeking in both directions as long as it isn't relative to EOF.
+%%
+%% Seeking backwards is extremely inefficient since we have to seek to the very
+%% beginning and then decompress up to the desired point.
+%%
+
+position(Data, Mark) when is_atom(Mark) ->
+    position(Data, {Mark, 0});
+position(Data, Offset) when is_integer(Offset) ->
+    position(Data, {bof, Offset});
+position(Data, {bof, Offset}) when is_integer(Offset) ->
+    position_1(Data, Offset);
+position(Data, {cur, Offset}) when is_integer(Offset) ->
+    #{ position := Position } = Data,
+    position_1(Data, Position + Offset);
+position(_Data, {eof, Offset}) when is_integer(Offset) ->
+    {error, einval};
+position(_Data, _Other) ->
+    {error, badarg}.
+
+position_1(_Data, Desired) when Desired < 0 ->
+    {error, einval};
+position_1(#{ position := Desired } = Data, Desired) ->
+    {ok, Data, Desired};
+position_1(#{ position := Current } = Data, Desired) when Current < Desired ->
+    case read(Data, min(Desired - Current, ?INFLATE_CHUNK_SIZE)) of
+        {ok, NewData, _Data} -> position_1(NewData, Desired);
+        eof -> {ok, Data, Current};
+        Other -> Other
+    end;
+position_1(#{ position := Current } = Data, Desired) when Current > Desired ->
+    #{ handle := PrivateFd, buffer := Buffer, zlib := Z } = Data,
+    case ?CALL_FD(PrivateFd, position, [bof]) of
+        {ok, 0} ->
+            ok = zlib:inflateReset(Z),
+            prim_buffer:wipe(Buffer),
+            position_1(Data#{ position => 0 }, Desired);
+        Other ->
+            Other
+    end.
+
+terminate(_Reason, _State, _Data) ->
+    ok.
diff --git a/lib/kernel/src/raw_file_io_list.erl b/lib/kernel/src/raw_file_io_list.erl
new file mode 100644
index 0000000000..2e16e63f0e
--- /dev/null
+++ b/lib/kernel/src/raw_file_io_list.erl
@@ -0,0 +1,128 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2017. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+-module(raw_file_io_list).
+
+-export([close/1, sync/1, datasync/1, truncate/1, advise/4, allocate/3,
+         position/2, write/2, pwrite/2, pwrite/3,
+         read_line/1, read/2, pread/2, pread/3]).
+
+%% OTP internal.
+-export([ipread_s32bu_p32bu/3, sendfile/8]).
+
+-export([open_layer/3]).
+
+-include("file_int.hrl").
+
+open_layer(Filename, Modes, [list]) ->
+    case raw_file_io:open(Filename, [binary | Modes]) of
+        {ok, PrivateFd} -> {ok, make_public_fd(PrivateFd, Modes)};
+        Other -> Other
+    end.
+
+%% We can skip wrapping the file if it's write-only since only read operations
+%% are affected by list mode. Since raw_file_io fills in all implicit options
+%% for us, all we need to do is check whether 'read' is among them.
+make_public_fd(PrivateFd, Modes) ->
+    case lists:member(read, Modes) of
+        true -> #file_descriptor{ module = ?MODULE, data = PrivateFd };
+        false -> PrivateFd
+    end.
+
+close(Fd) ->
+    PrivateFd = Fd#file_descriptor.data,
+    ?CALL_FD(PrivateFd, close, []).
+
+sync(Fd) ->
+    PrivateFd = Fd#file_descriptor.data,
+    ?CALL_FD(PrivateFd, sync, []).
+datasync(Fd) ->
+    PrivateFd = Fd#file_descriptor.data,
+    ?CALL_FD(PrivateFd, datasync, []).
+
+truncate(Fd) ->
+    PrivateFd = Fd#file_descriptor.data,
+    ?CALL_FD(PrivateFd, truncate, []).
+
+advise(Fd, Offset, Length, Advise) ->
+    PrivateFd = Fd#file_descriptor.data,
+    ?CALL_FD(PrivateFd, advise, [Offset, Length, Advise]).
+allocate(Fd, Offset, Length) ->
+    PrivateFd = Fd#file_descriptor.data,
+    ?CALL_FD(PrivateFd, allocate, [Offset, Length]).
+
+position(Fd, Mark) ->
+    PrivateFd = Fd#file_descriptor.data,
+    ?CALL_FD(PrivateFd, position, [Mark]).
+
+write(Fd, IOData) ->
+    PrivateFd = Fd#file_descriptor.data,
+    ?CALL_FD(PrivateFd, write, [IOData]).
+
+pwrite(Fd, Offset, IOData) ->
+    PrivateFd = Fd#file_descriptor.data,
+    ?CALL_FD(PrivateFd, pwrite, [Offset, IOData]).
+pwrite(Fd, LocBytes) ->
+    PrivateFd = Fd#file_descriptor.data,
+    ?CALL_FD(PrivateFd, pwrite, [LocBytes]).
+
+read_line(Fd) ->
+    PrivateFd = Fd#file_descriptor.data,
+    case ?CALL_FD(PrivateFd, read_line, []) of
+        {ok, Binary} -> {ok, binary_to_list(Binary)};
+        Other -> Other
+    end.
+read(Fd, Size) ->
+    PrivateFd = Fd#file_descriptor.data,
+    case ?CALL_FD(PrivateFd, read, [Size]) of
+        {ok, Binary} -> {ok, binary_to_list(Binary)};
+        Other -> Other
+    end.
+pread(Fd, Offset, Size) ->
+    PrivateFd = Fd#file_descriptor.data,
+    case ?CALL_FD(PrivateFd, pread, [Offset, Size]) of
+        {ok, Binary} -> {ok, binary_to_list(Binary)};
+        Other -> Other
+    end.
+pread(Fd, LocNums) ->
+    PrivateFd = Fd#file_descriptor.data,
+    case ?CALL_FD(PrivateFd, pread, [LocNums]) of
+        {ok, LocResults} ->
+            TranslatedResults =
+                [ case Result of
+                      Result when is_binary(Result) -> binary_to_list(Result);
+                      eof -> eof
+                  end || Result <- LocResults ],
+            {ok, TranslatedResults};
+        Other -> Other
+    end.
+
+ipread_s32bu_p32bu(Fd, Offset, MaxSize) ->
+    PrivateFd = Fd#file_descriptor.data,
+    case ?CALL_FD(PrivateFd, ipread_s32bu_p32bu, [Offset, MaxSize]) of
+        {ok, {Size, Pointer, Binary}} when is_binary(Binary) ->
+            {ok, {Size, Pointer, binary_to_list(Binary)}};
+        Other ->
+            Other
+    end.
+
+sendfile(Fd, Dest, Offset, Bytes, ChunkSize, Headers, Trailers, Flags) ->
+    Args = [Dest, Offset, Bytes, ChunkSize, Headers, Trailers, Flags],
+    PrivateFd = Fd#file_descriptor.data,
+    ?CALL_FD(PrivateFd, sendfile, Args).
diff --git a/lib/kernel/src/raw_file_io_raw.erl b/lib/kernel/src/raw_file_io_raw.erl
new file mode 100644
index 0000000000..9a9fe78eb1
--- /dev/null
+++ b/lib/kernel/src/raw_file_io_raw.erl
@@ -0,0 +1,25 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2017. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+-module(raw_file_io_raw).
+
+-export([open_layer/3]).
+
+open_layer(Filename, Modes, [raw]) ->
+    prim_file:open(Filename, [raw | Modes]).