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

5 files changed, 375 insertions, 5198 deletions

diff --git a/erts/emulator/drivers/common/efile_drv.c b/erts/emulator/drivers/common/efile_drv.c
deleted file mode 100644
index 4e1d2f0d7f..0000000000
--- a/erts/emulator/drivers/common/efile_drv.c
+++ /dev/null
@@ -1,4295 +0,0 @@
-/*
- * %CopyrightBegin%
- *
- * Copyright Ericsson AB 1996-2017. 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%
- */
-/*
- * Purpose: Provides file and directory operations.
- *
- * This file is generic, and does the work of decoding the commands
- * and encoding the responses.  System-specific functions are found in
- * the unix_efile.c and win_efile.c files.
- */
-
-/* Operations */
-
-#define FILE_OPEN		 1 /* Essential for startup */
-#define FILE_READ		 2
-#define FILE_LSEEK		 3
-#define FILE_WRITE		 4
-#define FILE_FSTAT		 5 /* Essential for startup */
-#define FILE_PWD                 6 /* Essential for startup */
-#define FILE_READDIR             7 /* Essential for startup */
-#define FILE_CHDIR               8
-#define FILE_FSYNC               9
-#define FILE_MKDIR              10
-#define FILE_DELETE             11
-#define FILE_RENAME             12
-#define FILE_RMDIR              13
-#define FILE_TRUNCATE           14
-#define FILE_READ_FILE          15 /* Essential for startup */
-#define FILE_WRITE_INFO		16
-#define FILE_LSTAT            	19
-#define FILE_READLINK        	20
-#define FILE_LINK             	21
-#define FILE_SYMLINK          	22
-#define FILE_CLOSE		23
-#define FILE_PWRITEV		24
-#define FILE_PREADV		25
-#define FILE_SETOPT		26
-#define FILE_IPREAD             27
-#define FILE_ALTNAME            28
-#define FILE_READ_LINE          29
-#define FILE_FDATASYNC          30
-#define FILE_FADVISE            31
-#define FILE_SENDFILE           32
-#define FILE_FALLOCATE          33
-#define FILE_CLOSE_ON_PORT_EXIT 34
-/* Return codes */
-
-#define FILE_RESP_OK         0
-#define FILE_RESP_ERROR      1
-#define FILE_RESP_DATA       2
-#define FILE_RESP_NUMBER     3
-#define FILE_RESP_INFO       4
-#define FILE_RESP_NUMERR     5
-#define FILE_RESP_LDATA      6
-#define FILE_RESP_N2DATA     7
-#define FILE_RESP_EOF        8
-#define FILE_RESP_FNAME      9
-#define FILE_RESP_ALL_DATA  10
-#define FILE_RESP_LFNAME    11
-
-/* Options */
-
-#define FILE_OPT_DELAYED_WRITE 0
-#define FILE_OPT_READ_AHEAD    1
-
-/* IPREAD variants */
-
-#define IPREAD_S32BU_P32BU 0
-
-/* Limits */
-
-#define FILE_SEGMENT_READ  (256*1024)
-#define FILE_SEGMENT_WRITE (256*1024)
-
-/* Internal */
-
-/* Set to 1 to test having read_ahead implicitly for read_line */ 
-#define ALWAYS_READ_LINE_AHEAD 0
-
-
-/* Must not be possible to get from malloc()! */
-#define FILE_FD_INVALID ((Sint)(-1))
-
-#ifdef HAVE_CONFIG_H
-#  include "config.h"
-#endif
-
-#include <ctype.h>
-#include <sys/types.h>
-#include <stdlib.h>
-
-/* Need (NON)BLOCKING macros for sendfile */
-#ifndef WANT_NONBLOCKING
-#define WANT_NONBLOCKING
-#endif
-
-#include "sys.h"
-
-#include "erl_driver.h"
-#include "erl_efile.h"
-#include "erl_threads.h"
-#include "gzio.h"
-#include "dtrace-wrapper.h" 
-
-
-static ErlDrvSysInfo sys_info;
-
-/* For explanation of this var, see comment for same var in erl_async.c */
-static unsigned gcc_optimizer_hack = 0;
-
-#ifdef  USE_VM_PROBES
-
-#define DTRACE_EFILE_BUFSIZ 128
-
-#define DTRACE_INVOKE_SETUP(op) \
-    do { DTRACE3(efile_drv_int_entry, d->sched_i1, d->sched_i2, op); } while (0)
-#define DTRACE_INVOKE_SETUP_BY_NAME(op) \
-    struct t_data *d = (struct t_data *) data ; \
-    DTRACE_INVOKE_SETUP(op)
-#define DTRACE_INVOKE_RETURN(op) \
-    do { DTRACE3(efile_drv_int_return, d->sched_i1, d->sched_i2, \
-                 op); } while (0) ; gcc_optimizer_hack++ ;
-
-/* Assign human-friendlier id numbers to scheduler & I/O worker threads */
-int             dt_driver_idnum = 0;
-int             dt_driver_io_worker_base = 5000;
-erts_mtx_t      dt_driver_mutex;
-pthread_key_t   dt_driver_key;
-
-typedef struct {
-    int         thread_num;
-    Uint64      tag;
-} dt_private;
-
-dt_private *get_dt_private(int);
-#else  /* USE_VM_PROBES */
-#define DTRACE_INVOKE_SETUP(op)            do {} while (0)
-#define DTRACE_INVOKE_SETUP_BY_NAME(op)    do {} while (0)
-#define DTRACE_INVOKE_RETURN(op)           do {} while (0)
-#endif  /* USE_VM_PROBES */
-
-/* #define TRACE 1 */
-#ifdef TRACE
-#    define TRACE_C(c) do { putchar(c); fflush(stdout); } while (0)
-#    define TRACE_S(s) do { fputs((s), stdout); fflush(stdout); } while (0)
-#    define TRACE_F(args) do { printf args ;fflush(stdout); } while (0)
-#else
-#    define TRACE_C(c) ((void)(0))
-#    define TRACE_S(s) ((void)(0))
-#    define TRACE_F(args) ((void)(0))
-#endif
-
-
-#define THRDS_AVAILABLE (sys_info.async_threads > 0)
-#ifdef HARDDEBUG /* HARDDEBUG in io.c is expected too */
-#define TRACE_DRIVER fprintf(stderr, "Efile: ")
-#else
-#define TRACE_DRIVER
-#endif
-#define MUTEX_INIT(m, p) do { IF_THRDS { TRACE_DRIVER; (m = driver_pdl_create(p)); } } while (0)
-#define MUTEX_LOCK(m)    do { IF_THRDS { TRACE_DRIVER; driver_pdl_lock(m);   } } while (0)
-#define MUTEX_UNLOCK(m)  do { IF_THRDS { TRACE_DRIVER; driver_pdl_unlock(m); } } while (0)
-#define IF_THRDS if (THRDS_AVAILABLE)
-
-
-#define SENDFILE_FLGS_USE_THREADS (1 << 0)
-/**
- * On DARWIN sendfile can deadlock with close if called in
- * different threads. So until Apple fixes so that sendfile
- * is not buggy we disable usage of the async pool for
- * DARWIN. The testcase t_sendfile_crashduring reproduces
- * this error when using +A 10 and enabling SENDFILE_FLGS_USE_THREADS.
- */
-#if defined(__APPLE__) && defined(__MACH__)
-#define USE_THRDS_FOR_SENDFILE(DATA) 0
-#else
-#define USE_THRDS_FOR_SENDFILE(DATA) (DATA->flags & SENDFILE_FLGS_USE_THREADS)
-#endif /* defined(__APPLE__) && defined(__MACH__) */
-
-
-
-#if 0
-/* Experimental, for forcing all file operations to use the same thread. */
-   static unsigned file_fixed_key = 1;
-#  define KEY(desc) (&file_fixed_key)
-#else
-#  define KEY(desc) (&(desc)->key)
-#endif
-
-#ifndef MAX
-#  define MAX(x, y) (((x) > (y)) ? (x) : (y))
-#endif
-
-#ifdef FILENAMES_16BIT
-#ifdef USE_VM_PROBES
-#error 16bit characters in filenames and dtrace in combination is not supported.
-#endif
-#  define FILENAME_BYTELEN(Str) filename_len_16bit(Str)
-#  define FILENAME_COPY(To,From) filename_cpy_16bit((To),(From)) 
-#  define FILENAME_CHARSIZE 2
-
-   static int filename_len_16bit(char *str) 
-   {
-       char *p = str;
-       while(*p != '\0' || p[1] != '\0') {
-	   p += 2;
-       }
-       return (p - str);
-   }
-
-   static void filename_cpy_16bit(char *to, char *from) 
-   {
-       while(*from != '\0' || from[1] != '\0') {
-	   *to++ = *from++;
-	   *to++ = *from++;
-       }
-       *to++ = *from++;
-       *to++ = *from++;
-   }
-
-#else
-#  define FILENAME_BYTELEN(Str) strlen(Str)
-#  define FILENAME_COPY(To,From) strcpy(To,From) 
-#  define FILENAME_CHARSIZE 1
-#endif
-
-#if     (MAXPATHLEN+1)*FILENAME_CHARSIZE+1 > BUFSIZ
-#  define    RESBUFSIZE  ((MAXPATHLEN+1)*FILENAME_CHARSIZE+1)
-#else
-#  define    RESBUFSIZE  BUFSIZ
-#endif
-
-#define READDIR_CHUNKS (5)
-
-
-
-#if ALWAYS_READ_LINE_AHEAD
-#define DEFAULT_LINEBUF_SIZE 2048
-#else
-#define DEFAULT_LINEBUF_SIZE 512 /* Small, it's usually discarded anyway */ 
-#endif
-
-typedef unsigned char uchar;
-
-static ErlDrvData file_start(ErlDrvPort port, char* command);
-static int file_init(void);
-static void file_stop(ErlDrvData);
-static void file_output(ErlDrvData, char* buf, ErlDrvSizeT len);
-static ErlDrvSSizeT file_control(ErlDrvData, unsigned int command,
-				 char* buf, ErlDrvSizeT len,
-				 char **rbuf, ErlDrvSizeT rlen);
-static void file_timeout(ErlDrvData);
-static void file_outputv(ErlDrvData, ErlIOVec*);
-static void file_async_ready(ErlDrvData, ErlDrvThreadData);
-static void file_flush(ErlDrvData);
-
-#ifdef HAVE_SENDFILE
-static void file_ready_output(ErlDrvData data, ErlDrvEvent event);
-static void file_stop_select(ErlDrvEvent event, void* _);
-#endif /* HAVE_SENDFILE */
-
-
-enum e_timer {timer_idle, timer_again, timer_write};
-#ifdef HAVE_SENDFILE
-enum e_sendfile {sending, not_sending};
-#define SENDFILE_USE_THREADS (1 << 0)
-#endif /* HAVE_SENDFILE */
-
-struct t_data;
-
-typedef struct {
-    SWord           fd;
-    ErlDrvPort      port;
-    unsigned int    key;      /* Async queue key */
-    unsigned        flags;    /* Original flags from FILE_OPEN. */
-    void          (*invoke)(void *);
-    struct t_data  *d;
-    void          (*free)(void *);
-    struct t_data  *cq_head;  /* Queue of incoming commands */
-    struct t_data  *cq_tail;  /* -""- */
-    enum e_timer    timer_state;
-#ifdef HAVE_SENDFILE
-    enum e_sendfile sendfile_state;
-#endif /* HAVE_SENDFILE */
-    size_t          read_bufsize;
-    ErlDrvBinary   *read_binp;
-    size_t          read_offset;
-    size_t          read_size;
-    size_t          write_bufsize;
-    unsigned long   write_delay;
-    int             write_error;
-    Efile_error     write_errInfo;
-    ErlDrvPDL       q_mtx;    /* Mutex for the driver queue, known by the emulator. Also used for
-				 mutual exclusion when accessing field(s) below. */
-    size_t          write_buffered;
-#ifdef USE_VM_PROBES
-    int             idnum;      /* Unique ID # for this driver thread/desc */
-    char            port_str[DTRACE_TERM_BUF_SIZE];
-#endif
-} file_descriptor;
-
-
-static int reply_error(file_descriptor*, Efile_error* errInfo);
-
-struct erl_drv_entry efile_driver_entry = {
-    file_init,
-    file_start,
-    file_stop,
-    file_output,
-    NULL,
-#ifdef HAVE_SENDFILE
-    file_ready_output,
-#else
-    NULL,
-#endif /* HAVE_SENDFILE */
-    "efile",
-    NULL,
-    NULL,
-    file_control,
-    file_timeout,
-    file_outputv,
-    file_async_ready,
-    file_flush,
-    NULL,
-    NULL,
-    ERL_DRV_EXTENDED_MARKER,
-    ERL_DRV_EXTENDED_MAJOR_VERSION,
-    ERL_DRV_EXTENDED_MINOR_VERSION,
-    ERL_DRV_FLAG_USE_PORT_LOCKING,
-    NULL,
-    NULL,
-#ifdef HAVE_SENDFILE
-    file_stop_select
-#else
-    NULL
-#endif /* HAVE_SENDFILE */
-};
-
-
-
-static int thread_short_circuit;
-
-#define DRIVER_ASYNC(level, desc, f_invoke, data, f_free) \
-if (thread_short_circuit >= (level)) { \
-    (*(f_invoke))(data); \
-    file_async_ready((ErlDrvData)(desc), (data)); \
-} else { \
-    driver_async((desc)->port, KEY(desc), (f_invoke), (data), (f_free)); \
-}
-
-
-
-struct t_pbuf_spec {
-    Sint64 offset;
-    size_t size;
-};
-
-struct t_pwritev {
-    ErlDrvPort         port;
-    ErlDrvPDL          q_mtx;
-    size_t             size;
-    unsigned           cnt;
-    unsigned           n;
-    struct t_pbuf_spec specs[1];
-};
-
-struct t_preadv {
-    ErlIOVec eiov;
-    unsigned n;
-    unsigned cnt;
-    size_t   size;
-    Sint64   offsets[1];
-};
-
-#define READDIR_BUFSIZE (8*1024)*READDIR_CHUNKS
-#if READDIR_BUFSIZE < (1 + (2 + MAXPATHLEN)*FILENAME_CHARSIZE*READDIR_CHUNKS)
-#  undef READDIR_BUFSIZE
-#  define READDIR_BUFSIZE (1 + (2 + MAXPATHLEN)*FILENAME_CHARSIZE*READDIR_CHUNKS)
-#endif
-
-struct t_readdir_buf {
-     struct t_readdir_buf *next;
-     size_t n;
-     char buf[READDIR_BUFSIZE];
-};
-
-struct t_data
-{
-    struct t_data *next;
-    int            command;
-    int            level;
-    void         (*invoke)(void *);
-    void         (*free)(void *);
-    void           *data_to_free; /* used by FILE_CLOSE_ON_PORT_EXIT only */
-    int            again;
-    int            reply;
-#ifdef  USE_VM_PROBES
-    int               sched_i1;
-    Uint64            sched_i2;
-    char              sched_utag[DTRACE_EFILE_BUFSIZ+1];
-#endif
-    int            result_ok;
-    Efile_error    errInfo;
-    int            flags;
-    SWord          fd;
-    int            is_fd_unused;
-    /**/
-    Efile_info        info;
-    EFILE_DIR_HANDLE  dir_handle; /* Handle to open directory. */
-    ErlDrvBinary     *bin;
-    int               drive;
-    size_t            n;
-    /*off_t             offset;*/
-    /*size_t            bytesRead; Bytes read from the file. */
-    /**/
-    union {
-	struct {
-	    Sint64 offset;
-	    int    origin;
-	    Sint64 location;
-	} lseek;
-	struct {
-	    ErlDrvPort    port;
-	    ErlDrvPDL     q_mtx;
-	    size_t        size;
-	    size_t        reply_size;
-	} writev;
-	struct t_pwritev pwritev;
-	struct t_preadv  preadv;
-	struct {
-	    ErlDrvBinary *binp;
-	    size_t        bin_offset;
-	    size_t        bin_size;
-	    size_t        size;
-	} read;
-	struct {
-	    ErlDrvBinary *binp; /* in - out */
-	    size_t        read_offset; /* in - out */
-	    size_t        read_size; /* in - out */
-	    size_t        nl_pos; /* out */
-	    short         nl_skip; /* out, 0 or 1 */
-#if !ALWAYS_READ_LINE_AHEAD
-	    short         read_ahead; /* in, bool */
-#endif
-	} read_line;
-	struct {
-	    ErlDrvBinary *binp;
-	    int           size;
-	    int           offset;
-	} read_file;
-	struct {
-	    struct t_readdir_buf *first_buf;
-	    struct t_readdir_buf *last_buf;
-	} read_dir;
-	struct {
-	    Sint64 offset;
-	    Sint64 length;
-	    int advise;
-	} fadvise;
-#ifdef HAVE_SENDFILE
-	struct {
-	    ErlDrvPort port;
-	    ErlDrvPDL q_mtx;
-	    int out_fd;
-	    off_t offset;
-	    Uint64 nbytes;
-	    Uint64 written;
-	} sendfile;
-#endif /* HAVE_SENDFILE */
-	struct {
-	    Sint64 offset;
-	    Sint64 length;
-	} fallocate;
-    } c;
-    char b[1];
-};
-
-#define EF_ALLOC(S)		driver_alloc((S))
-#define EF_REALLOC(P, S)	driver_realloc((P), (S))
-#define EF_SAFE_ALLOC(S)	ef_safe_alloc((S))
-#define EF_SAFE_REALLOC(P, S)	ef_safe_realloc((P), (S))
-#define EF_FREE(P)		do { if((P)) driver_free((P)); } while(0)
-
-static void *ef_safe_alloc(Uint s)
-{
-    void *p = EF_ALLOC(s);
-    if (!p) erts_exit(ERTS_ERROR_EXIT, "efile drv: Can't allocate %lu bytes of memory\n", (unsigned long)s);
-    return p;
-}
-
-/*********************************************************************
- * ErlIOVec manipulation functions.
- */
-
-/* char EV_CHAR_P(ErlIOVec *ev, int p, int q) */
-#define EV_CHAR_P(ev, p, q)			\
-    (((char *)(ev)->iov[q].iov_base) + (p))
-
-/* int EV_GET_CHAR(ErlIOVec *ev, char *p, int *pp, int *qp) */
-#define EV_GET_CHAR(ev, p, pp, qp) efile_ev_get_char(ev, p ,pp, qp)
-static int
-efile_ev_get_char(ErlIOVec *ev, char *p, size_t *pp, size_t *qp) {
-    if (*pp + 1 <= ev->iov[*qp].iov_len) {
-	*p = *EV_CHAR_P(ev, *pp, *qp);
-	if (*pp + 1 < ev->iov[*qp].iov_len)
-	    *pp += 1;
-	else {
-	    *qp += 1;
-	    *pp = 0;
-	}
-	return !0;
-    }
-    return 0;
-}
-
-/* Uint32 EV_UINT32(ErlIOVec *ev, int p, int q)*/
-#define EV_UINT32(ev, p, q)						\
-    ((Uint32) ((unsigned char *)(ev)->iov[q].iov_base)[p])
-
-/* int EV_GET_UINT32(ErlIOVec *ev, Uint32 *p, int *pp, int *qp) */
-#define EV_GET_UINT32(ev, p, pp, qp) efile_ev_get_uint32(ev, p, pp, qp)
-static int
-efile_ev_get_uint32(ErlIOVec *ev, Uint32 *p, size_t *pp, size_t *qp) {
-    if (*pp + 4 <= ev->iov[*qp].iov_len) {
-	*p = (EV_UINT32(ev, *pp,   *qp) << 24)
-	    | (EV_UINT32(ev, *pp + 1, *qp) << 16)
-	    | (EV_UINT32(ev, *pp + 2, *qp) << 8)
-	    | (EV_UINT32(ev, *pp + 3, *qp));
-	if (*pp + 4 < ev->iov[*qp].iov_len)
-	    *pp += 4;
-	else {
-	    *qp += 1;
-	    *pp = 0;
-	}
-	return !0;
-    }
-    return 0;
-}
-
-/* Uint64 EV_UINT64(ErlIOVec *ev, int p, int q)*/
-#define EV_UINT64(ev, p, q)						\
-    ((Uint64) ((unsigned char *)(ev)->iov[q].iov_base)[p])
-
-/* int EV_GET_UINT64(ErlIOVec *ev, Uint64 *p, int *pp, int *qp) */
-#define EV_GET_UINT64(ev, p, pp, qp) efile_ev_get_uint64(ev, p, pp, qp)
-static int
-efile_ev_get_uint64(ErlIOVec *ev, Uint64 *p, size_t *pp, size_t *qp) {
-    if (*pp + 8 <= ev->iov[*qp].iov_len) {
-	*p = (EV_UINT64(ev, *pp, *qp) << 56)
-	    | (EV_UINT64(ev, *pp + 1, *qp) << 48)
-	    | (EV_UINT64(ev, *pp + 2, *qp) << 40)
-	    | (EV_UINT64(ev, *pp + 3, *qp) << 32)
-	    | (EV_UINT64(ev, *pp + 4, *qp) << 24)
-	    | (EV_UINT64(ev, *pp + 5, *qp) << 16)
-	    | (EV_UINT64(ev, *pp + 6, *qp) << 8)
-	    | (EV_UINT64(ev, *pp + 7, *qp));
-	if (*pp + 8 < ev->iov[*qp].iov_len)
-	    *pp += 8;
-	else {
-	    *qp += 1;
-	    *pp = 0;
-	}
-	return !0;
-    }
-    return 0;
-}
-
-/* int EV_GET_SINT64(ErlIOVec *ev, Uint64 *p, int *pp, int *qp) */
-#define EV_GET_SINT64(ev, p, pp, qp) efile_ev_get_sint64(ev, p, pp, qp)
-static int
-efile_ev_get_sint64(ErlIOVec *ev, Sint64 *p, size_t *pp, size_t *qp) {
-    Uint64 *tmp = (Uint64*)p;
-    return EV_GET_UINT64(ev, tmp, pp, qp);
-}
-
-#if 0
-
-static void ev_clear(ErlIOVec *ev) {
-    ASSERT(ev);
-    ev->size = 0;
-    ev->vsize = 0;
-    ev->iov = NULL;
-    ev->binv = NULL;
-}
-
-/* Assumes that ->iov and ->binv were allocated with sys_alloc().
- */
-static void ev_free(ErlIOVec *ev) {
-    if (! ev) {
-	return;
-    }
-    if (ev->vsize > 0) {
-	int i;
-	ASSERT(ev->iov);
-	ASSERT(ev->binv);
-	for (i = 0; i < ev->vsize; i++) {
-	    if (ev->binv[i]) {
-		driver_free_binary(ev->binv[i]);
-	    }
-	}
-	EF_FREE(ev->iov);
-	EF_FREE(ev->binv);
-    }
-}
-
-/* Copy the contents from source to dest.
- * Data in binaries is not copied, just the pointers; 
- * and refc is incremented.
- */
-static ErlIOVec *ev_copy(ErlIOVec *dest, ErlIOVec *source) {
-    int *ip;
-    ASSERT(dest);
-    ASSERT(source);
-    if (source->vsize == 0) {
-	/* Empty source */
-	ev_clear(dest);
-	return dest;
-    }
-    /* Allocate ->iov and ->binv */
-    dest->iov = EF_ALLOC(sizeof(*dest->iov) * source->vsize);
-    if (! dest->iov) {
-	return NULL;
-    }
-    dest->binv = EF_ALLOC(sizeof(*dest->binv) * source->vsize);
-    if (! dest->binv) {
-	EF_FREE(dest->iov);
-	return NULL;
-    }
-    dest->size = source->size;
-    /* Copy one vector element at the time. 
-     * Use *ip as an alias for dest->vsize to improve readabiliy.
-     * Keep dest consistent in every iteration by using 
-     * dest->vsize==*ip as loop variable.
-     */
-    for (ip = &dest->vsize, *ip = 0;  *ip < source->vsize;  (*ip)++) {
-	if (source->iov[*ip].iov_len == 0) {
-	    /* Empty vector element */
-	    dest->iov[*ip].iov_len = 0;
-	    dest->iov[*ip].iov_base = NULL;
-	    dest->binv[*ip] = NULL;
-	} else {
-	    /* Non empty vector element */
-	    if (source->binv[*ip]) {
-		/* Contents in binary - copy pointers and increment refc */
-		dest->iov[*ip] = source->iov[*ip];
-		dest->binv[*ip] = source->binv[*ip];
-		driver_binary_inc_refc(source->binv[*ip]);
-	    } else {
-		/* Contents not in binary - allocate new binary and copy data */
-		if (! (dest->binv[*ip] = 
-		       driver_alloc_binary(source->iov[*ip].iov_len))) {
-		    goto failed;
-		}
-		sys_memcpy(dest->binv[*ip]->orig_bytes,
-			   source->iov[*ip].iov_base,
-			   source->iov[*ip].iov_len);
-		dest->iov[*ip].iov_base = dest->binv[*ip]->orig_bytes;
-		dest->iov[*ip].iov_len = source->iov[*ip].iov_len;
-	    }
-	}
-    }
-    return dest;
- failed:
-    ev_free(dest);
-    return NULL;
-}
-
-#endif
-
-
-
-/*********************************************************************
- * Command queue functions
- */
-
-static void cq_enq(file_descriptor *desc, struct t_data *d) {
-    ASSERT(d);
-    if (desc->cq_head) {
-	ASSERT(desc->cq_tail);
-	ASSERT(!desc->cq_tail->next);
-	desc->cq_tail = desc->cq_tail->next = d;
-    } else {
-	ASSERT(desc->cq_tail == NULL);
-	desc->cq_head = desc->cq_tail = d;
-    }
-    d->next = NULL;
-}
-
-static struct t_data *cq_deq(file_descriptor *desc) {
-    struct t_data *d = desc->cq_head;
-    ASSERT(d || (!d && !desc->cq_tail));
-    if (d) {
-	ASSERT(!d->next || (d->next && desc->cq_tail != d));
-	if ((desc->cq_head = d->next) == NULL) {
-	    ASSERT(desc->cq_tail == d);
-	    desc->cq_tail = NULL;
-	}
-    }	
-    return d;
-}
-
-
-/*********************************************************************
- * Driver entry point -> init
- */
-static int 
-file_init(void)
-{
-    char buf[21]; /* enough to hold any 64-bit integer */
-    size_t bufsz = sizeof(buf);
-    thread_short_circuit = (erl_drv_getenv("ERL_EFILE_THREAD_SHORT_CIRCUIT",
-					   buf,
-					   &bufsz) == 0
-			    ? atoi(buf)
-			    : 0);
-    driver_system_info(&sys_info, sizeof(ErlDrvSysInfo));
-
-    /* run initiation of efile_driver if needed */
-    efile_init();
-
-#ifdef  USE_VM_PROBES
-    erts_mtx_init(&dt_driver_mutex, "efile_drv dtrace mutex", NIL,
-        ERTS_LOCK_FLAGS_PROPERTY_STATIC | ERTS_LOCK_FLAGS_CATEGORY_IO);
-    pthread_key_create(&dt_driver_key, NULL);
-#endif  /* USE_VM_PROBES */
-
-    return 0;
-}
-
-
-/*********************************************************************
- * Driver entry point -> start
- */
-static ErlDrvData 
-file_start(ErlDrvPort port, char* command) 
-
-{
-    file_descriptor* desc;
-
-    if ((desc = (file_descriptor*) EF_ALLOC(sizeof(file_descriptor)))
-	== NULL) {
-	errno = ENOMEM;
-	return ERL_DRV_ERROR_ERRNO;
-    }
-    desc->fd = FILE_FD_INVALID;
-    desc->port = port;
-    desc->key = driver_async_port_key(port);
-    desc->flags = 0;
-    desc->invoke = NULL;
-    desc->d = NULL;
-    desc->free = NULL;
-    desc->cq_head = NULL;
-    desc->cq_tail = NULL;
-    desc->timer_state = timer_idle;
-#ifdef HAVE_SENDFILE
-    desc->sendfile_state = not_sending;
-#endif
-    desc->read_bufsize = 0;
-    desc->read_binp = NULL;
-    desc->read_offset = 0;
-    desc->read_size = 0;
-    desc->write_delay = 0L;
-    desc->write_bufsize = 0;
-    desc->write_error = 0;
-    MUTEX_INIT(desc->q_mtx, port); /* Refc is one, referenced by emulator now */
-    desc->write_buffered = 0;
-#ifdef  USE_VM_PROBES
-    dtrace_drvport_str(port, desc->port_str);
-    get_dt_private(0);           /* throw away return value */
-#endif  /* USE_VM_PROBES */
-    return (ErlDrvData) desc;
-}
-
-static void do_close(int flags, SWord fd) {
-    if (flags & EFILE_COMPRESSED) {
-	erts_gzclose((ErtsGzFile)(fd));
-    } else {
-	efile_closefile((int) fd);
-    }
-}
-
-static void invoke_close(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-    DTRACE_INVOKE_SETUP(FILE_CLOSE);
-    d->again = 0;
-    do_close(d->flags, d->fd);
-    DTRACE_INVOKE_RETURN(FILE_CLOSE);
-}
-
-static void free_data(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-
-    switch (d->command) {
-    case FILE_OPEN:
-        if (d->is_fd_unused && d->fd != FILE_FD_INVALID) {
-            /* This is OK to do in scheduler thread because there can be no async op
-               ongoing for this fd here, as we exited during async open.
-               Ideally, this close should happen in an async thread too, but that would
-               require a substantial rewrite, as we are here because of a dead port and
-               cannot schedule async jobs for that port any more... */
-            do_close(d->flags, d->fd);
-        }
-        break;
-    case FILE_CLOSE_ON_PORT_EXIT:
-        EF_FREE(d->data_to_free);
-        break;
-    }
-
-    EF_FREE(data);
-}
-
-
-/*
- * Sends back an error reply to Erlang.
- */
-
-static void reply_posix_error(file_descriptor *desc, int posix_errno) {
-    char response[256];		/* Response buffer. */
-    char* s;
-    char* t;
-    
-    /*
-     * Contents of buffer sent back:
-     *
-     * +-----------------------------------------+
-     * | FILE_RESP_ERROR | Posix error id string |
-     * +-----------------------------------------+
-     */
-
-    TRACE_C('E');
-
-    response[0] = FILE_RESP_ERROR;
-    for (s = erl_errno_id(posix_errno), t = response+1; *s; s++, t++)
-	*t = tolower(*s);
-    driver_output2(desc->port, response, t-response, NULL, 0);
-}
-
-static void reply_Uint_posix_error(file_descriptor *desc, Uint num, 
-				   int posix_errno) {
-    char response[256];		/* Response buffer. */
-    char* s;
-    char* t;
-    
-    /*
-     * Contents of buffer sent back:
-     *
-     * +----------------------------------------------------------------------+
-     * | FILE_RESP_NUMERR | 64-bit number (big-endian) | Posix error id string |
-     * +----------------------------------------------------------------------+
-     */
-
-    TRACE_C('N');
-
-    response[0] = FILE_RESP_NUMERR;
-#if SIZEOF_VOID_P == 4
-    put_int32(0, response+1);
-#else
-    put_int32(num>>32, response+1);
-#endif
-    put_int32((Uint32)num, response+1+4);
-    for (s = erl_errno_id(posix_errno), t = response+1+4+4; *s; s++, t++)
-	*t = tolower(*s);
-    driver_output2(desc->port, response, t-response, NULL, 0);
-}
-
-#ifdef HAVE_SENDFILE
-static void reply_string_error(file_descriptor *desc, char* str) {
-    char response[256];		/* Response buffer. */
-    char* s;
-    char* t;
-
-    response[0] = FILE_RESP_ERROR;
-    for (s = str, t = response+1; *s; s++, t++)
-	*t = tolower(*s);
-    driver_output2(desc->port, response, t-response, NULL, 0);
-}
-#endif
-
-static int reply_error(file_descriptor *desc, 
-		       Efile_error *errInfo) /* The error codes. */
-{
-    reply_posix_error(desc, errInfo->posix_errno);
-    return 0;
-}
-
-static int reply_Uint_error(file_descriptor *desc, Uint num, 
-			    Efile_error *errInfo) /* The error codes. */
-{
-    reply_Uint_posix_error(desc, num, errInfo->posix_errno);
-    return 0;
-}
-
-static int reply_ok(file_descriptor *desc) {
-    char c = FILE_RESP_OK;
-
-    driver_output2(desc->port, &c, 1, NULL, 0);
-    return 0;
-}
-
-static int reply(file_descriptor *desc, int ok, Efile_error *errInfo) {
-    if (!ok) {
-	reply_error(desc, errInfo);
-    } else {
-	TRACE_C('K');
-	reply_ok(desc);
-    }
-    return 0;
-}
-
-static int reply_Uint(file_descriptor *desc, Uint result) {
-    char tmp[1+4+4];
-
-    /*
-     * Contents of buffer sent back:
-     *
-     * +-----------------------------------------------+
-     * | FILE_RESP_NUMBER | 64-bit number (big-endian) |
-     * +-----------------------------------------------+
-     */
-
-    TRACE_C('R');
-
-    tmp[0] = FILE_RESP_NUMBER;
-#if SIZEOF_VOID_P == 4
-    put_int32(0, tmp+1);
-#else
-    put_int32(result>>32, tmp+1);
-#endif
-    put_int32((Uint32)result, tmp+1+4);
-    driver_output2(desc->port, tmp, sizeof(tmp), NULL, 0);
-    return 0;
-}
-
-static int reply_Sint64(file_descriptor *desc, Sint64 result) {
-    char tmp[1+4+4];
-
-    /*
-     * Contents of buffer sent back:
-     *
-     * +-----------------------------------------------+
-     * | FILE_RESP_NUMBER | 64-bit number (big-endian) |
-     * +-----------------------------------------------+
-     */
-
-    TRACE_C('R');
-
-    tmp[0] = FILE_RESP_NUMBER;
-    put_int64(result, tmp+1);
-    driver_output2(desc->port, tmp, sizeof(tmp), NULL, 0);
-    return 0;
-}
-
-#if 0
-static void reply_again(file_descriptor *desc) {
-    char tmp[1];
-    tmp[0] = FILE_RESP_AGAIN;
-    driver_output2(desc->port, tmp, sizeof(tmp), NULL, 0);
-}
-#endif
-
-static void reply_ev(file_descriptor *desc, char response, ErlIOVec *ev) {
-    char tmp[1];
-    /* Data arriving at the Erlang process:
-     * [Response, Binary0, Binary1, .... | BinaryN-1]
-     */
-    tmp[0] = response;
-    driver_outputv(desc->port, tmp, sizeof(tmp), ev, 0);
-}
-
-static void reply_data(file_descriptor *desc, 
-		       ErlDrvBinary *binp, size_t offset, size_t len) {
-    char header[1+4+4];
-    /* Data arriving at the Erlang process:
-     * [?FILE_RESP_DATA, 64-bit length (big-endian) | Data]
-     */
-    header[0] = FILE_RESP_DATA;
-#if SIZEOF_SIZE_T == 4
-    put_int32(0, header+1);
-#else
-    put_int32(len>>32, header+1);
-#endif
-    put_int32((Uint32)len, header+1+4);
-    driver_output_binary(desc->port, header, sizeof(header),
-			 binp, offset, len);
-}
-
-static void reply_buf(file_descriptor *desc, char *buf, size_t len) {
-    char header[1+4+4];
-    /* Data arriving at the Erlang process:
-     * [?FILE_RESP_DATA, 64-bit length (big-endian) | Data]
-     */
-    header[0] = FILE_RESP_DATA;
-#if SIZEOF_SIZE_T == 4
-    put_int32(0, header+1);
-#else
-    put_int32(len>>32, header+1);
-#endif
-    put_int32((Uint32)len, header+1+4);
-    driver_output2(desc->port, header, sizeof(header), buf, len);
-}
-
-static int reply_eof(file_descriptor *desc) {
-    char c = FILE_RESP_EOF;
-
-    driver_output2(desc->port, &c, 1, NULL, 0);
-    return 0;
-}
- 
-static void invoke_name(void *data, int (*f)(Efile_error *, char *))
-{
-    struct t_data *d = (struct t_data *) data;
-    char *name = (char *) d->b;
-
-    d->again = 0;
-    d->result_ok = (*f)(&d->errInfo, name);
-}
-
-static void invoke_mkdir(void *data)
-{
-    DTRACE_INVOKE_SETUP_BY_NAME(FILE_MKDIR);
-    invoke_name(data, efile_mkdir);
-    DTRACE_INVOKE_RETURN(FILE_MKDIR);
-}
-
-static void invoke_rmdir(void *data)
-{
-    DTRACE_INVOKE_SETUP_BY_NAME(FILE_RMDIR);
-    invoke_name(data, efile_rmdir);
-    DTRACE_INVOKE_RETURN(FILE_RMDIR);
-}
-
-static void invoke_delete_file(void *data)
-{
-    DTRACE_INVOKE_SETUP_BY_NAME(FILE_DELETE);
-    invoke_name(data, efile_delete_file);
-    DTRACE_INVOKE_RETURN(FILE_DELETE);
-}
-
-static void invoke_chdir(void *data)
-{
-    DTRACE_INVOKE_SETUP_BY_NAME(FILE_CHDIR);
-    invoke_name(data, efile_chdir);
-    DTRACE_INVOKE_RETURN(FILE_CHDIR);
-}
-
-static void invoke_fdatasync(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-    int fd = (int) d->fd;
-    DTRACE_INVOKE_SETUP(FILE_FDATASYNC);
-
-    d->again = 0;
-    d->result_ok = efile_fdatasync(&d->errInfo, fd);
-    DTRACE_INVOKE_RETURN(FILE_FDATASYNC);
-}
-
-static void invoke_fsync(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-    int fd = (int) d->fd;
-    DTRACE_INVOKE_SETUP(FILE_FSYNC);
-
-    d->again = 0;
-    d->result_ok = efile_fsync(&d->errInfo, fd);
-    DTRACE_INVOKE_RETURN(FILE_FSYNC);
-}
-
-static void invoke_truncate(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-    int fd = (int) d->fd;
-    DTRACE_INVOKE_SETUP(FILE_TRUNCATE);
-
-    d->again = 0;
-    d->result_ok = efile_truncate_file(&d->errInfo, &fd, d->flags);
-    DTRACE_INVOKE_RETURN(FILE_TRUNCATE);
-}
-
-static void invoke_read(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-    int status, segment;
-    size_t size, read_size;
-    DTRACE_INVOKE_SETUP(FILE_READ);
-
-    segment = d->again && d->c.read.bin_size >= 2*FILE_SEGMENT_READ;
-    if (segment) {
-	size = FILE_SEGMENT_READ;
-    } else {
-	size = d->c.read.bin_size;
-    }
-    read_size = size;
-    if (d->flags & EFILE_COMPRESSED) {
-	read_size = erts_gzread((ErtsGzFile)d->fd,
-				d->c.read.binp->orig_bytes + d->c.read.bin_offset,
-				size);
-	status = (read_size != (size_t) -1);
-	if (!status) {
-	    d->errInfo.posix_errno = EIO;
-	}
-    } else {
-	status = efile_read(&d->errInfo, d->flags, (int) d->fd,
-			    d->c.read.binp->orig_bytes + d->c.read.bin_offset,
-			    size,
-			    &read_size);
-    }
-    if ( (d->result_ok = status)) {
-	ASSERT(read_size <= size);
-	d->c.read.bin_offset += read_size;
-	if (read_size < size || !segment) {
-	    d->c.read.bin_size = 0;
-	    d->again = 0;
-	} else {
-	    d->c.read.bin_size -= read_size;
-	}
-    } else {
-	d->again = 0;
-    }
-    DTRACE_INVOKE_RETURN(FILE_READ);
-}
-
-static void free_read(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-
-    driver_free_binary(d->c.read.binp);
-    EF_FREE(d);
-}
-
-static void invoke_read_line(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-    int status;
-    size_t read_size = 0;
-    int local_loop = (d->again == 0);
-    DTRACE_INVOKE_SETUP(FILE_READ_LINE);
-
-    do {
-	size_t size = (d->c.read_line.binp)->orig_size - 
-	    d->c.read_line.read_offset - d->c.read_line.read_size;
-	if (size == 0) {
-	    /* Need more place */
-	    ErlDrvSizeT need = (d->c.read_line.read_size >= DEFAULT_LINEBUF_SIZE) ?
-		d->c.read_line.read_size + DEFAULT_LINEBUF_SIZE : DEFAULT_LINEBUF_SIZE;
-	    ErlDrvBinary   *newbin;
-#if !ALWAYS_READ_LINE_AHEAD
-	    /* Use read_ahead size if need does not exceed it */
-	    if (need < (d->c.read_line.binp)->orig_size && 
-		d->c.read_line.read_ahead)
-	      need = (d->c.read_line.binp)->orig_size;
-#endif
-	    newbin = driver_alloc_binary(need);
-	    if (newbin == NULL) {
-		d->result_ok = 0;
-		d->errInfo.posix_errno = ENOMEM;
-		d->again = 0;
-		break;
-	    }
-	    memcpy(newbin->orig_bytes, (d->c.read_line.binp)->orig_bytes + d->c.read_line.read_offset,  
-		   d->c.read_line.read_size);
-	    driver_free_binary(d->c.read_line.binp);
-	    d->c.read_line.binp = newbin;
-	    d->c.read_line.read_offset = 0;
-	    size = need - d->c.read_line.read_size;
-	}
-	if (d->flags & EFILE_COMPRESSED) {
-	    read_size = erts_gzread((ErtsGzFile)d->fd,
-				    d->c.read_line.binp->orig_bytes + 
-				    d->c.read_line.read_offset + d->c.read_line.read_size,
-				    size);
-	    status = (read_size != (size_t) -1);
-	    if (!status) {
-		d->errInfo.posix_errno = EIO;
-	    }
-	} else {
-	    status = efile_read(&d->errInfo, d->flags, (int) d->fd,
-				d->c.read_line.binp->orig_bytes + 
-				d->c.read_line.read_offset + d->c.read_line.read_size,
-				size,
-				&read_size);
-	}
-	if ( (d->result_ok = status)) {
-	    void *nl_ptr = memchr((d->c.read_line.binp)->orig_bytes + 
-				  d->c.read_line.read_offset + d->c.read_line.read_size,'\n',read_size);
-	    ASSERT(read_size <= size);
-	    d->c.read_line.read_size += read_size;
-	    if (nl_ptr != NULL) {
-		/* If found, we're done */
-		d->c.read_line.nl_pos = ((char *) nl_ptr) - 
-		    ((char *) ((d->c.read_line.binp)->orig_bytes)) + 1;
-		if (d->c.read_line.nl_pos > 1 &&
-		    *(((char *) nl_ptr) - 1) == '\r') {
-		    --d->c.read_line.nl_pos;
-		    *(((char *) nl_ptr) - 1) = '\n';
-		    d->c.read_line.nl_skip = 1;
-		} else {
-		    d->c.read_line.nl_skip = 0;
-		}
-		d->again = 0;
-#if !ALWAYS_READ_LINE_AHEAD
-		if (!(d->c.read_line.read_ahead)) {
-		    /* Ouch! Undo buffering... */
-		    size_t too_much = d->c.read_line.read_size - d->c.read_line.nl_skip - 
-			(d->c.read_line.nl_pos - d->c.read_line.read_offset);
-		    d->c.read_line.read_size -= too_much;
-		    ASSERT(d->c.read_line.read_size >= 0);
-		    if (d->flags & EFILE_COMPRESSED) {
-			Sint64 location = erts_gzseek((ErtsGzFile)d->fd,
-						      -((Sint64) too_much), EFILE_SEEK_CUR);
-			if (location == -1) {
-			    d->result_ok = 0;
-			    d->errInfo.posix_errno = errno;
-			}
-		    } else {
-			Sint64 location;
-			d->result_ok = efile_seek(&d->errInfo, (int) d->fd, 
-						-((Sint64) too_much), EFILE_SEEK_CUR,
-						&location);
-		    }
-		}
-#endif
-		break;
-	    } else if (read_size == 0) {
-		d->c.read_line.nl_pos = 
-		    d->c.read_line.read_offset + d->c.read_line.read_size;
-		d->c.read_line.nl_skip = 0;
-		d->again = 0;
-		break;
-	    }
-	} else {
-	    d->again = 0;
-	    break;
-	}
-    } while (local_loop);
-    DTRACE_INVOKE_RETURN(FILE_READ_LINE);
-}
-
-static void free_read_line(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-
-    driver_free_binary(d->c.read_line.binp);
-    EF_FREE(d);
-}
-
-void read_file_zero_size(struct t_data* d);
-#define ZERO_FILE_CHUNK (64 * 1024)
-
-/* [ERL-327] Some special files like /proc/... have reported size 0 */
-void read_file_zero_size(struct t_data* d) {
-    size_t total_read_size = 0;
-    size_t allocated_size = ZERO_FILE_CHUNK; /* allocd in invoke_read_file */
-    for (;;) {
-        size_t read_result;
-
-        /* Read until we hit EOF (read less than FILE_SEGMENT_READ) */
-        d->result_ok = efile_read(&d->errInfo,
-                                  EFILE_MODE_READ,
-                                  (int) d->fd,
-                                  (d->c.read_file.binp->orig_bytes +
-                                   total_read_size),
-                                  ZERO_FILE_CHUNK,
-                                  &read_result);
-        if (!d->result_ok) {
-            break;
-        }
-
-        total_read_size += read_result;
-        d->c.read_file.offset += read_result;
-        if (read_result < ZERO_FILE_CHUNK) {
-            break;
-        }
-
-        /* Grow before the next read call */
-        allocated_size = total_read_size + ZERO_FILE_CHUNK;
-        d->c.read_file.binp = driver_realloc_binary(d->c.read_file.binp,
-                                                    allocated_size);
-    }
-
-    /* Finalize the memory usage. Hopefully it was read fully on the first
-     * go, so the binary allocation overhead becomes:
-     * alloc ZERO_FILE_CHUNK (64kb) -> realloc real_size */
-    if (allocated_size != total_read_size) {
-        d->c.read_file.binp = driver_realloc_binary(d->c.read_file.binp,
-                                                    total_read_size);
-    }
-    d->again = 0;
-}
-
-static void invoke_read_file(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-    size_t read_size;
-    int chop;
-    DTRACE_INVOKE_SETUP(FILE_READ_FILE);
-    
-    if (! d->c.read_file.binp) { /* First invocation only */
-	int fd;
-	Sint64 size;
-	
-	if (! (d->result_ok = 
-	       efile_openfile(&d->errInfo, d->b, 
-			      EFILE_MODE_READ, &fd, &size))) {
-	    goto done;
-	}
-	d->fd = fd;
-	d->c.read_file.size = (int) size;
-
-        /* For zero sized files allocate a reasonable chunk to attempt reading
-         * anyway. Note: This will eat ZERO_FILE_CHUNK bytes for any 0 file
-         * and free them immediately after (if the file was empty). */
-        ERTS_ASSERT(size >= 0);
-        d->c.read_file.binp = driver_alloc_binary(size != 0 ? (size_t)size
-                                                            : ZERO_FILE_CHUNK);
-
-	if (size < 0 || size != d->c.read_file.size || !d->c.read_file.binp) {
-	    d->result_ok = 0;
-	    d->errInfo.posix_errno = ENOMEM;
-	    goto close;
-	}
-	d->c.read_file.offset = 0;
-    }
-    /* Invariant: d->c.read_file.size >= d->c.read_file.offset */
-    
-    if (d->c.read_file.size == 0) {
-        read_file_zero_size(d);
-        goto close;
-    }
-
-    read_size = (size_t) (d->c.read_file.size - d->c.read_file.offset);
-    if (! read_size) goto close;
-    chop = d->again && read_size >= FILE_SEGMENT_READ*2;
-    if (chop) read_size = FILE_SEGMENT_READ;
-    d->result_ok = 
-	efile_read(&d->errInfo, 
-		   EFILE_MODE_READ, 
-		   (int) d->fd, 
-		   d->c.read_file.binp->orig_bytes + d->c.read_file.offset,
-		   read_size, 
-		   &read_size);
-    if (d->result_ok) {
-	d->c.read_file.offset += read_size;
-	if (chop) goto chop_done; /* again */
-    }
- close:
-    efile_closefile((int) d->fd);
- done:
-    d->again = 0;
- chop_done:
-    DTRACE_INVOKE_RETURN(FILE_READ_FILE);
-}
-
-static void free_read_file(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-
-    if (d->c.read_file.binp) driver_free_binary(d->c.read_file.binp);
-    EF_FREE(d);
-}
-
-
-
-static void invoke_preadv(void *data)
-{
-    struct t_data   *d = (struct t_data *) data;
-    struct t_preadv *c = &d->c.preadv;
-    ErlIOVec        *ev = &c->eiov;
-    size_t           bytes_read_so_far = 0;
-    unsigned char   *p = (unsigned char *)ev->iov[0].iov_base + 4+4+8*c->cnt;
-    DTRACE_INVOKE_SETUP(FILE_PREADV);
-
-    while (c->cnt < c->n) {
-	size_t read_size = ev->iov[1 + c->cnt].iov_len - c->size;
-	size_t bytes_read = 0;
-	int chop = d->again 
-	    && bytes_read_so_far + read_size >= 2*FILE_SEGMENT_READ;
-	if (chop) {
-	    ASSERT(bytes_read_so_far < FILE_SEGMENT_READ);
-	    read_size = FILE_SEGMENT_READ + FILE_SEGMENT_READ/2
-		- bytes_read_so_far;
-	}
-	if ( (d->result_ok 
-	      = efile_pread(&d->errInfo, 
-			    (int) d->fd,
-			    c->offsets[c->cnt] + c->size,
-			    ((char *)ev->iov[1 + c->cnt].iov_base) + c->size,
-			    read_size,
-			    &bytes_read))) {
-	    bytes_read_so_far += bytes_read;
-	    if (chop && bytes_read == read_size) {
-		c->size += bytes_read;
-		goto done;
-	    }
-	    ASSERT(bytes_read <= read_size);
-	    ev->iov[1 + c->cnt].iov_len = bytes_read + c->size;
-	    ev->size += bytes_read + c->size;
-	    put_int64(bytes_read + c->size, p); p += 8;
-	    c->size = 0;
-	    c->cnt++;
-	    if (d->again 
-		&& bytes_read_so_far >= FILE_SEGMENT_READ
-		&& c->cnt < c->n) {
-		goto done;
-	    }
-	} else {
-	    /* In case of a read error, ev->size will not be correct,
-	     * which does not matter since no read data is returned
-	     * to Erlang.
-	     */
-	    break;
-	}
-    }					
-    d->again = 0;
- done:
-    DTRACE_INVOKE_RETURN(FILE_PREADV);
-}
-
-static void free_preadv(void *data) {
-    struct t_data *d = data;
-    int            i;
-    ErlIOVec      *ev = &d->c.preadv.eiov;
-    
-    for(i = 0; i < ev->vsize; i++) {
-	driver_free_binary(ev->binv[i]);
-    }
-    EF_FREE(d);
-}
-
-static void invoke_ipread(void *data)
-{
-    struct t_data   *d = data;
-    struct t_preadv *c = &d->c.preadv;
-    ErlIOVec        *ev = &c->eiov;
-    size_t bytes_read = 0;
-    char buf[2*sizeof(Uint32)];
-    Uint32 offset, size;
-    DTRACE_INVOKE_SETUP(FILE_IPREAD);
-    
-    /* Read indirection header */
-    if (! efile_pread(&d->errInfo, (int) d->fd, c->offsets[0], 
-		      buf, sizeof(buf), &bytes_read)) {
-	goto error;
-    }
-    if (bytes_read != sizeof(buf)) goto done; /* eof */
-    size = get_int32(buf);
-    offset = get_int32(buf+4);
-    if (size > c->size) goto done; /* eof */
-    c->n = 1;
-    c->cnt = 0;
-    c->size = 0;
-    c->offsets[0] = offset;
-    if (! (ev->binv[0] = driver_alloc_binary(3*8))) {
-	d->errInfo.posix_errno = ENOMEM;
-	goto error;
-    }
-    ev->vsize = 1;
-    ev->iov[0].iov_len = 3*8;
-    ev->iov[0].iov_base = ev->binv[0]->orig_bytes;
-    ev->size = ev->iov[0].iov_len;
-    put_int64(offset, ev->iov[0].iov_base);
-    put_int64(size, ((char *)ev->iov[0].iov_base) + 2*8);
-    if (size == 0) {
-	put_int64(size, ((char *)ev->iov[0].iov_base) + 8);
-	goto done;
-    }
-    if (! (ev->binv[1] = driver_alloc_binary(size))) {
-	d->errInfo.posix_errno = ENOMEM;
-	goto error;
-    }
-    ev->vsize = 2;
-    ev->iov[1].iov_len = size;
-    ev->iov[1].iov_base = ev->binv[1]->orig_bytes;
-    /* Read data block */
-    d->invoke = invoke_preadv;
-    invoke_preadv(data);
-    DTRACE_INVOKE_RETURN(FILE_IPREAD);
-    return;
- error:
-    d->result_ok = 0;
-    d->again = 0;
-    DTRACE_INVOKE_RETURN(FILE_IPREAD);
-    return;
- done:
-    d->result_ok = !0;
-    d->again = 0;
-    DTRACE_INVOKE_RETURN(FILE_IPREAD);
-}
-
-/* invoke_writev and invoke_pwritev are the only thread functions that
- * access non-thread data i.e the port queue and a mutex in the port
- * structure that is used to lock the port queue.
- *
- * The port will normally not be terminated until the port queue is
- * empty, but if the port is killed, i.e., exit(Port, kill) is called,
- * it will terminate regardless of the port queue state. When the
- * port is invalid driver_peekq() returns NULL and set the size to -1,
- * and driver_sizeq() returns -1.
- */
-
-static void invoke_writev(void *data) {
-    struct t_data *d = (struct t_data *) data;
-    SysIOVec      *iov0;
-    SysIOVec      *iov;
-    int            iovlen;
-    int            iovcnt;
-    size_t         size;
-    size_t         p;
-    int            segment;
-    DTRACE_INVOKE_SETUP(FILE_WRITE);
-
-    segment = d->again && d->c.writev.size >= 2*FILE_SEGMENT_WRITE;
-    if (segment) {
-	size = FILE_SEGMENT_WRITE;
-    } else {
-	size = d->c.writev.size;
-    }
-
-    /* Copy the io vector to avoid locking the port que while writing,
-     * also, both we and efile_writev might/will change the SysIOVec
-     * when segmenting or due to partial write and we do not want to
-     * tamper with the actual queue that we get from driver_peekq
-     */
-    MUTEX_LOCK(d->c.writev.q_mtx); /* Lock before accessing the port queue */
-    iov0 = driver_peekq(d->c.writev.port, &iovlen);
-
-    /* Calculate iovcnt */
-    for (p = 0, iovcnt = 0;
-	 p < size && iovcnt < iovlen;
-	 p += iov0[iovcnt++].iov_len)
-	;
-    iov = EF_SAFE_ALLOC(sizeof(SysIOVec)*iovcnt);
-    memcpy(iov,iov0,iovcnt*sizeof(SysIOVec));
-    MUTEX_UNLOCK(d->c.writev.q_mtx);
-    /* Let go of lock until we deque from original vector */
-
-    if (iovlen > 0) {
-	ASSERT(iov[iovcnt-1].iov_len > p - size);
-	iov[iovcnt-1].iov_len -= p - size;
-	if (d->flags & EFILE_COMPRESSED) {
-	    int i, status = 1;
-	    for (i = 0; i < iovcnt; i++) {
-		if (iov[i].iov_base && iov[i].iov_len > 0) {
-		    /* Just in case, I do not know what gzwrite does
-		     * with errno.
-		     */
-		    errno = EINVAL; 
-		    status = erts_gzwrite((ErtsGzFile)d->fd,
-					  iov[i].iov_base,
-					  iov[i].iov_len) == iov[i].iov_len;
-		    if (! status) {
-			d->errInfo.posix_errno =
-			    d->errInfo.os_errno = errno; /* XXX Correct? */
-			break;
-		    }
-		}
-	    }
-	    d->result_ok = status;
-	} else {
-	    d->result_ok = efile_writev(&d->errInfo, 
-					d->flags, (int) d->fd,
-					iov, iovcnt);
-	}
-    } else if (iovlen == 0) {
-	d->result_ok = 1;
-    }
-    else { /* Port has terminated */
-	d->result_ok = 0;
-	d->errInfo.posix_errno = d->errInfo.os_errno = EINVAL;
-    }
-    EF_FREE(iov);
-
-    if (! d->result_ok) {
-	d->again = 0;
-	MUTEX_LOCK(d->c.writev.q_mtx);
-	driver_deq(d->c.writev.port, d->c.writev.size);
-	MUTEX_UNLOCK(d->c.writev.q_mtx);
-    } else {
-	if (! segment) {
-	    d->again = 0;
-	}
-	d->c.writev.size -= size;
-	TRACE_F(("w%lu", (unsigned long)size));
-	MUTEX_LOCK(d->c.writev.q_mtx);
-	driver_deq(d->c.writev.port, size);
-	MUTEX_UNLOCK(d->c.writev.q_mtx);
-    }
-
-
-    DTRACE_INVOKE_RETURN(FILE_WRITE);
-}
-
-static void invoke_pwd(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-    DTRACE_INVOKE_SETUP(FILE_PWD);
-
-    d->again = 0;
-    d->result_ok = efile_getdcwd(&d->errInfo,d->drive, d->b+1,
-				 RESBUFSIZE-1);
-    DTRACE_INVOKE_RETURN(FILE_PWD);
-}
-
-static void invoke_readlink(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-    char resbuf[RESBUFSIZE];	/* Result buffer. */
-    DTRACE_INVOKE_SETUP(FILE_READLINK);
-
-    d->again = 0;
-    d->result_ok = efile_readlink(&d->errInfo, d->b, resbuf+1,
-				  RESBUFSIZE-1);
-    if (d->result_ok != 0)
-	FILENAME_COPY((char *) d->b + 1, resbuf+1);
-    DTRACE_INVOKE_RETURN(FILE_READLINK);
-}
-
-static void invoke_altname(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-    char resbuf[RESBUFSIZE];	/* Result buffer. */
-    DTRACE_INVOKE_SETUP(FILE_ALTNAME);
-
-    d->again = 0;
-    d->result_ok = efile_altname(&d->errInfo, d->b, resbuf+1,
-				  RESBUFSIZE-1);
-    if (d->result_ok != 0)
-	FILENAME_COPY((char *) d->b + 1, resbuf+1);
-    DTRACE_INVOKE_RETURN(FILE_ALTNAME);
-}
-
-static void invoke_pwritev(void *data) {
-    struct t_data* const d = (struct t_data *) data;
-    struct t_pwritev * const c = &d->c.pwritev;
-    SysIOVec         *iov0;
-    SysIOVec         *iov;
-    int               iovlen;
-    int               iovcnt;
-    size_t            p;
-    int               segment;
-    size_t            size, write_size, written;
-    DTRACE_INVOKE_SETUP(FILE_PWRITEV);
-
-    segment = d->again && c->size >= 2*FILE_SEGMENT_WRITE;
-    if (segment) {
-	size = FILE_SEGMENT_WRITE;
-    } else {
-	size = c->size;
-    }
-    d->result_ok = !0;
-    p = 0;
-    /* Lock the queue just for a while, we don't want it locked during write */
-    MUTEX_LOCK(c->q_mtx);
-    iov0 = driver_peekq(c->port, &iovlen);
-    iov = EF_SAFE_ALLOC(sizeof(SysIOVec)*iovlen);
-    memcpy(iov,iov0,sizeof(SysIOVec)*iovlen);
-    MUTEX_UNLOCK(c->q_mtx);
-
-    if (iovlen < 0)
-	goto error; /* Port terminated */
-    for (iovcnt = 0, written = 0;
-	 c->cnt < c->n && iovcnt < iovlen && written < size;
-	 c->cnt++) {
-	int chop;
-	write_size = c->specs[c->cnt].size;
-	if (iov[iovcnt].iov_len - p < write_size) {
-	    goto error;
-	}
-	chop = segment && written + write_size >= 2*FILE_SEGMENT_WRITE;
-	if (chop) {
-	    ASSERT(written < FILE_SEGMENT_WRITE);
-	    write_size = FILE_SEGMENT_WRITE + FILE_SEGMENT_WRITE/2 
-		- written;
-	}
-	d->result_ok = efile_pwrite(&d->errInfo, (int) d->fd,
-				    (char *)(iov[iovcnt].iov_base) + p,
-				    write_size,
-				    c->specs[c->cnt].offset);
-	if (! d->result_ok) {
-	    d->again = 0;
-	    goto deq_error;
-	}
-	written += write_size; 
-	c->size -= write_size;
-	if (chop) { 
-	    c->specs[c->cnt].offset += write_size;
-	    c->specs[c->cnt].size -= write_size;
-	    /* Schedule out (d->again != 0) */
-	    break;
-	}
-	/* Move forward in buffer */
-	p += write_size;
-	ASSERT(iov[iovcnt].iov_len >= p);
-	if (iov[iovcnt].iov_len == p) {
-	    /* Move to next iov[], we trust that it is not a 
-	     * zero length vector, and thereby depend on that
-	     * such are not queued.
-	     */
-	    iovcnt++; p = 0;
-	}
-    }
-    if (! segment) {
-	if (c->cnt != c->n) {
-	    /* Mismatch between number of 
-	     * pos/size specs vs number of queued buffers .
-	     */
-	error:
-	    d->errInfo.posix_errno = EINVAL;
-	    d->result_ok = 0;
-	    d->again = 0;
-	deq_error:
-	    MUTEX_LOCK(c->q_mtx);
-	    driver_deq(c->port, c->size);
-	    MUTEX_UNLOCK(c->q_mtx);
-
-	    goto done;
-	} else {
-	    ASSERT(written == size);
-	    d->again = 0;
-	}
-    } else {
-      ASSERT(written >= FILE_SEGMENT_WRITE);
-    }
-      
-    MUTEX_LOCK(c->q_mtx);
-    driver_deq(c->port, written);
-    MUTEX_UNLOCK(c->q_mtx);
- done:
-    EF_FREE(iov); /* Free our copy of the vector, nothing to restore */
-    
-    DTRACE_INVOKE_RETURN(FILE_PWRITEV);
-}
-
-static void invoke_flstat(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-
-    DTRACE3(efile_drv_int_entry, d->sched_i1, d->sched_i2,
-            d->command == FILE_LSTAT ? FILE_LSTAT : FILE_FSTAT);
-    d->again = 0;
-    d->result_ok = efile_fileinfo(&d->errInfo, &d->info,
-				  d->b, d->command == FILE_LSTAT);
-    DTRACE3(efile_drv_int_entry, d->sched_i1, d->sched_i2,
-            d->command == FILE_LSTAT ? FILE_LSTAT : FILE_FSTAT);
-    gcc_optimizer_hack++;
-}
-
-static void invoke_link(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-    char *name = d->b;
-    char *new_name;
-    DTRACE_INVOKE_SETUP(FILE_LINK);
-
-    d->again = 0;
-    new_name = name+FILENAME_BYTELEN(name)+FILENAME_CHARSIZE;
-    d->result_ok = efile_link(&d->errInfo, name, new_name);
-    DTRACE_INVOKE_RETURN(FILE_LINK);
-}
-
-static void invoke_symlink(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-    char *name = d->b;
-    char *new_name;
-    DTRACE_INVOKE_SETUP(FILE_SYMLINK);
-
-    d->again = 0;
-    new_name = name+FILENAME_BYTELEN(name)+FILENAME_CHARSIZE;
-    d->result_ok = efile_symlink(&d->errInfo, name, new_name);
-    DTRACE_INVOKE_RETURN(FILE_SYMLINK);
-}
-
-static void invoke_rename(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-    char *name = d->b;
-    char *new_name;
-    DTRACE_INVOKE_SETUP(FILE_RENAME);
-
-    d->again = 0;
-    new_name = name+FILENAME_BYTELEN(name)+FILENAME_CHARSIZE;
-    d->result_ok = efile_rename(&d->errInfo, name, new_name);
-    DTRACE_INVOKE_RETURN(FILE_RENAME);
-}
-
-static void invoke_write_info(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-    DTRACE_INVOKE_SETUP(FILE_WRITE_INFO);
-
-    d->again = 0;
-    d->result_ok = efile_write_info(&d->errInfo, &d->info, d->b);
-    DTRACE_INVOKE_RETURN(FILE_WRITE_INFO);
-}
-
-static void invoke_lseek(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-    int status;
-    DTRACE_INVOKE_SETUP(FILE_LSEEK);
-
-    d->again = 0;
-    if (d->flags & EFILE_COMPRESSED) {
-	int offset = (int) d->c.lseek.offset;
-	
-	if (offset != d->c.lseek.offset) {
-	    d->errInfo.posix_errno = EINVAL;
-	    status = 0;
-	} else {
-	    d->c.lseek.location = erts_gzseek((ErtsGzFile)d->fd,
-					      offset, d->c.lseek.origin);
-	    if (d->c.lseek.location == -1) {
-		d->errInfo.posix_errno = errno;
-		status = 0;
-	    } else {
-		status = 1;
-	    }
-	}
-    } else {
-	status = efile_seek(&d->errInfo, (int) d->fd, 
-			    d->c.lseek.offset, d->c.lseek.origin,
-			    &d->c.lseek.location);
-    }
-    d->result_ok = status;
-    DTRACE_INVOKE_RETURN(FILE_LSEEK);
-}
-
-static void invoke_readdir(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-    char *p = NULL;
-    size_t file_bs;
-    size_t n = 0, total = 0;
-    struct t_readdir_buf *b = NULL;
-    int res = 0;
-    DTRACE_INVOKE_SETUP(FILE_READDIR);
-
-    d->again = 0;
-    d->errInfo.posix_errno = 0;
-
-    do {
-	total   = READDIR_BUFSIZE;
-	n       = 1;
-	b       = EF_SAFE_ALLOC(sizeof(struct t_readdir_buf));
-	b->next = NULL;
-	
-	if (d->c.read_dir.last_buf) {
-	    d->c.read_dir.last_buf->next = b;
-	} else {
-	    d->c.read_dir.first_buf = b;
-	}
-	d->c.read_dir.last_buf = b;
-
-	p       = &b->buf[0];
-	p[0]    = FILE_RESP_LFNAME;
-	file_bs = READDIR_BUFSIZE - n;
-
-	do {
-	    res = efile_readdir(&d->errInfo, d->b, &d->dir_handle, p + n + 2, &file_bs);
-
-	    if (res) {
-		put_int16((Uint16)file_bs, p + n);
-		n += 2 + file_bs;
-		file_bs = READDIR_BUFSIZE - n;
-	    }
-	} while( res && ((total - n - 2) >= MAXPATHLEN*FILENAME_CHARSIZE));
-
-	b->n = n;
-    } while(res);
-
-    d->result_ok = (d->errInfo.posix_errno == 0);
-    DTRACE_INVOKE_RETURN(FILE_READDIR);
-}
-
-static void invoke_open(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-    int status = 1;		/* Status of open call. */
-    DTRACE_INVOKE_SETUP(FILE_OPEN);
-
-    d->again = 0;
-    if ((d->flags & EFILE_COMPRESSED) == 0) {
-	int fd;
-	status = efile_openfile(&d->errInfo, d->b, d->flags, &fd, NULL);
-	d->fd = fd;
-    } else {
-	char* mode = NULL;
-
-	if (((d->flags & (EFILE_MODE_READ_WRITE)) == EFILE_MODE_READ_WRITE) ||
-	    (d->flags & EFILE_MODE_APPEND)) {
-	    status = 0;
-	    d->errInfo.posix_errno = EINVAL;
-	} else {
-	    status = efile_may_openfile(&d->errInfo, d->b);
-	    if (status || (d->errInfo.posix_errno != EISDIR)) {
-		mode = (d->flags & EFILE_MODE_READ) ? "rb" : "wb";
-		d->fd = (SWord) erts_gzopen(d->b, mode);
-		if ((ErtsGzFile)d->fd) {
-		    status = 1;
-		} else {
-		    if (errno == 0) {
-			errno = ENOMEM;
-		    }
-		    d->errInfo.posix_errno = errno;
-		    status = 0;
-		}
-	    }
-	}
-    }
-
-    d->result_ok = status;
-    if (!status) {
-        d->fd = FILE_FD_INVALID;
-    }
-    DTRACE_INVOKE_RETURN(FILE_OPEN);
-}
-
-static void invoke_fadvise(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-    int fd = (int) d->fd;
-    off_t offset = (off_t) d->c.fadvise.offset;
-    off_t length = (off_t) d->c.fadvise.length;
-    int advise = (int) d->c.fadvise.advise;
-    DTRACE_INVOKE_SETUP(FILE_FADVISE);
-
-    d->again = 0;
-    d->result_ok = efile_fadvise(&d->errInfo, fd, offset, length, advise);
-    DTRACE_INVOKE_RETURN(FILE_FADVISE);
-}
-
-#ifdef HAVE_SENDFILE
-static void invoke_sendfile(void *data)
-{
-    struct t_data *d = (struct t_data *)data;
-    int fd = d->fd;
-    int out_fd = (int)d->c.sendfile.out_fd;
-    Uint64 nbytes = d->c.sendfile.nbytes;
-    int result = 0;
-    d->again = 0;
-
-    result = efile_sendfile(&d->errInfo, fd, out_fd, &d->c.sendfile.offset, &nbytes, NULL);
-
-    d->c.sendfile.written += nbytes;
-
-    if (result == 1 || (result == 0 && USE_THRDS_FOR_SENDFILE(d))) {
-      d->result_ok = 0;
-    } else if (result == 0 && (d->errInfo.posix_errno == EAGAIN
-				 || d->errInfo.posix_errno == EINTR)) {
-      if ((d->c.sendfile.nbytes - nbytes) != 0) {
-	d->result_ok = 1;
-	if (d->c.sendfile.nbytes != 0)
-	  d->c.sendfile.nbytes -= nbytes;
-      } else if (nbytes == 0 && d->c.sendfile.nbytes == 0) {
-	d->result_ok = 1;
-      } else
-	d->result_ok = 0;
-    } else {
-	d->result_ok = -1;
-    }
-}
-
-static void free_sendfile(void *data) {
-    struct t_data *d = (struct t_data *)data;
-    if (USE_THRDS_FOR_SENDFILE(d)) {
-	SET_NONBLOCKING(d->c.sendfile.out_fd);
-    } else {
-	MUTEX_LOCK(d->c.sendfile.q_mtx);
-	driver_deq(d->c.sendfile.port,1);
-	MUTEX_UNLOCK(d->c.sendfile.q_mtx);
-	driver_select(d->c.sendfile.port, (ErlDrvEvent)(long)d->c.sendfile.out_fd,
-                      ERL_DRV_USE_NO_CALLBACK|ERL_DRV_WRITE, 0);
-    }
-    EF_FREE(data);
-}
-
-static void file_ready_output(ErlDrvData data, ErlDrvEvent event)
-{
-    file_descriptor* fd = (file_descriptor*) data;
-
-    switch (fd->d->command) {
-    case FILE_SENDFILE:
-	driver_select(fd->d->c.sendfile.port, event,
-		      (int)ERL_DRV_WRITE,(int) 0);
-	invoke_sendfile((void *)fd->d);
-	file_async_ready(data, (ErlDrvThreadData)fd->d);
-	break;
-    default:
-	break;
-    }
-}
-
-static void file_stop_select(ErlDrvEvent event, void* _)
-{
-
-}
-
-static int flush_sendfile(file_descriptor *desc,void *_) {
-    if (desc->sendfile_state == sending) {
-	desc->d->result_ok = -1;
-	desc->d->errInfo.posix_errno = ECONNABORTED;
-	file_async_ready((ErlDrvData)desc,(ErlDrvThreadData)desc->d);
-    }
-    return 1;
-}
-#endif /* HAVE_SENDFILE */
-
-
-static void invoke_fallocate(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-    int fd = (int) d->fd;
-    Sint64 offset = d->c.fallocate.offset;
-    Sint64 length = d->c.fallocate.length;
-
-    d->again = 0;
-    d->result_ok = efile_fallocate(&d->errInfo, fd, offset, length);
-}
-
-static void free_readdir(void *data)
-{
-    struct t_data *d = (struct t_data *) data;
-    struct t_readdir_buf *b1 = d->c.read_dir.first_buf;
-
-    while (b1) {
-	struct t_readdir_buf *b2 = b1;
-	b1 = b1->next;
-	EF_FREE(b2);
-    }
-    EF_FREE(d);
-}
-
-
-
-static void try_free_read_bin(file_descriptor *desc) {
-    if ((desc->read_size == 0)
-	&& (desc->read_offset >= desc->read_binp->orig_size)) {
-	ASSERT(desc->read_offset == desc->read_binp->orig_size);
-	driver_free_binary(desc->read_binp);
-	desc->read_binp = NULL;
-	desc->read_offset = 0;
-	desc->read_size = 0;
-    }
-}
-
-
-
-static int try_again(file_descriptor *desc, struct t_data *d) {
-    if (! d->again)
-	return 0;
-    if (desc->timer_state != timer_idle) {
-	driver_cancel_timer(desc->port);
-    }
-    desc->timer_state = timer_again;
-    desc->invoke = d->invoke;
-    desc->d = d;
-    desc->free = d->free;
-    driver_set_timer(desc->port, 0L);
-    return !0;
-}
-
-
-
-static void cq_execute(file_descriptor *desc) {
-    struct t_data *d;
-    register void *void_ptr; /* Soft cast variable */
-    if (desc->timer_state == timer_again)
-	return;
-#ifdef HAVE_SENDFILE
-    if (desc->sendfile_state == sending)
-	return;
-#endif
-    if (! (d = cq_deq(desc)))
-	return;
-    TRACE_F(("x%i", (int) d->command));
-    d->again = sys_info.async_threads == 0;
-    DRIVER_ASYNC(d->level, desc, d->invoke, void_ptr=d, d->free);
-}
-
-static struct t_data *async_write(file_descriptor *desc, int *errp,
-		       int reply, Uint32 reply_size
-#ifdef USE_VM_PROBES
-		       ,Sint64 *dt_i1, Sint64 *dt_i2, Sint64 *dt_i3
-#endif
-) {
-    struct t_data *d;
-    if (! (d = EF_ALLOC(sizeof(struct t_data) - 1))) {
-	if (errp) *errp = ENOMEM;
-	return NULL;
-    }
-    TRACE_F(("w%lu", (unsigned long)desc->write_buffered));
-    d->command = FILE_WRITE;
-    d->fd = desc->fd;
-    d->flags = desc->flags;
-    d->c.writev.port = desc->port;
-    d->c.writev.q_mtx = desc->q_mtx;
-    d->c.writev.size = desc->write_buffered;
-#ifdef USE_VM_PROBES
-    if (dt_i1 != NULL) {
-        *dt_i1 = d->fd;
-        *dt_i2 = d->flags;
-        *dt_i3 = d->c.writev.size;
-    }
-#endif
-    d->reply = reply;
-    d->c.writev.reply_size = reply_size;
-    d->invoke = invoke_writev;
-    d->free = free_data;
-    d->level = 1;
-    cq_enq(desc, d);
-    desc->write_buffered = 0;
-    return d;
-}
-
-static int flush_write(file_descriptor *desc, int *errp
-#ifdef USE_VM_PROBES
-                       , dt_private *dt_priv, char *dt_utag
-#endif
-) {
-    int    result = 0;
-#ifdef USE_VM_PROBES
-    Sint64 dt_i1 = 0, dt_i2 = 0, dt_i3 = 0;
-#endif
-    struct t_data *d = NULL;
-
-    MUTEX_LOCK(desc->q_mtx);
-    if (desc->write_buffered > 0) {
-	if ((d = async_write(desc, errp, 0, 0
-#ifdef USE_VM_PROBES
-			     ,&dt_i1, &dt_i2, &dt_i3
-#endif
-			     )) == NULL) {
-            result = -1;
-        }
-    }
-    MUTEX_UNLOCK(desc->q_mtx);
-#ifdef USE_VM_PROBES
-    if (d != NULL) {
-        d->sched_i1 = dt_priv->thread_num;
-        d->sched_i2 = dt_priv->tag;
-        d->sched_utag[0] = '\0';
-        if (dt_utag != NULL) {
-            if (dt_utag[0] == '\0') {
-                dt_utag = NULL;
-            } else {
-                strncpy(d->sched_utag, dt_utag, sizeof(d->sched_utag) - 1);
-                d->sched_utag[sizeof(d->sched_utag) - 1] = '\0';
-            }
-        }
-        DTRACE11(efile_drv_entry, dt_priv->thread_num, dt_priv->tag++,
-                 dt_utag, FILE_WRITE,
-                 NULL, NULL, dt_i1, dt_i2, dt_i3, 0, desc->port_str);
-    }
-#endif /* USE_VM_PROBES */
-    return result;
-}
-
-static int check_write_error(file_descriptor *desc, int *errp) {
-    if (desc->write_error) {
-	if (errp) *errp = desc->write_errInfo.posix_errno;
-	desc->write_error = 0;
-	return -1;
-    }
-    return 0;
-}
-
-static int flush_write_check_error(file_descriptor *desc, int *errp
-#ifdef USE_VM_PROBES
-                                   , dt_private *dt_priv, char *dt_utag
-#endif
-				   ) {
-    int r;
-    if ( (r = flush_write(desc, errp
-#ifdef USE_VM_PROBES
-			  , dt_priv, dt_utag
-#endif
-			  )) != 0) {
-	check_write_error(desc, NULL);
-	return r;
-    } else {
-	return check_write_error(desc, errp);
-    }
-}
-
-static struct t_data *async_lseek(file_descriptor *desc, int *errp, int reply,
-				  Sint64 offset, int origin
-#ifdef USE_VM_PROBES
-				  , Sint64 *dt_i1, Sint64 *dt_i2, Sint64 *dt_i3
-#endif
-				  ) {
-    struct t_data *d;
-    if (! (d = EF_ALLOC(sizeof(struct t_data)))) {
-	*errp = ENOMEM;
-	return NULL;
-    }
-    d->flags = desc->flags;
-    d->fd = desc->fd;
-    d->command = FILE_LSEEK;
-    d->reply = reply;
-    d->c.lseek.offset = offset;
-    d->c.lseek.origin = origin;
-#ifdef USE_VM_PROBES
-    if (dt_i1 != NULL) {
-        *dt_i1 = d->fd;
-        *dt_i2 = d->c.lseek.offset;
-        *dt_i3 = d->c.lseek.origin;
-    }
-#endif
-    d->invoke = invoke_lseek;
-    d->free = free_data;
-    d->level = 1;
-    cq_enq(desc, d);
-    return d;
-}
-
-static void flush_read(file_descriptor *desc) {
-    desc->read_offset = 0;
-    desc->read_size = 0;
-    if (desc->read_binp) {
-	driver_free_binary(desc->read_binp);
-	desc->read_binp = NULL;
-    }
-}
-
-static int lseek_flush_read(file_descriptor *desc, int *errp
-#ifdef USE_VM_PROBES
-			    ,dt_private *dt_priv, char *dt_utag
-#endif
-			    ) {
-    int r = 0;
-    size_t read_size = desc->read_size;
-#ifdef USE_VM_PROBES
-    Sint64 dt_i1 = 0, dt_i2 = 0, dt_i3 = 0;
-#endif
-    struct t_data *d;
-
-    flush_read(desc);
-    if (read_size != 0) {
-	if ((d = async_lseek(desc, errp, 0,
-                             -((ssize_t)read_size), EFILE_SEEK_CUR
-#ifdef USE_VM_PROBES
-			     , &dt_i1, &dt_i2, &dt_i3
-#endif
-			     )) == NULL) {
-            r = -1;
-        } else {
-#ifdef USE_VM_PROBES
-            d->sched_i1 = dt_priv->thread_num;
-            d->sched_i2 = dt_priv->tag;
-            d->sched_utag[0] = '\0';
-            if (dt_utag != NULL) {
-                if (dt_utag[0] == '\0') {
-                    dt_utag = NULL;
-                } else {
-                    strncpy(d->sched_utag, dt_utag, sizeof(d->sched_utag) - 1);
-                    d->sched_utag[sizeof(d->sched_utag) - 1] = '\0';
-                }
-            }
-            DTRACE11(efile_drv_entry, dt_priv->thread_num, dt_priv->tag++,
-                     dt_utag, FILE_LSEEK,
-                     NULL, NULL, dt_i1, dt_i2, dt_i3, 0, desc->port_str);
-#endif /* USE_VM_PROBES */
-        }
-    }
-    return r;
-}
-
-
-/*********************************************************************
- * Driver entry point -> stop
- * The close has to be scheduled on async thread, so that currently active
- * async operation does not suddenly have the ground disappearing under their feet...
- */
-static void 
-file_stop(ErlDrvData e)
-{
-    file_descriptor* desc = (file_descriptor*)e;
-
-    TRACE_C('p');
-
-    IF_THRDS {
-	flush_read(desc);
-	if (desc->fd != FILE_FD_INVALID) {
-	    struct t_data *d = EF_SAFE_ALLOC(sizeof(struct t_data));
-	    d->command = FILE_CLOSE_ON_PORT_EXIT;
-	    d->reply = !0;
-	    d->fd = desc->fd;
-	    d->flags = desc->flags;
-	    d->invoke = invoke_close;
-	    d->free = free_data;
-	    d->level = 2;
-	    d->data_to_free = (void *) desc;
-	    cq_enq(desc, d);
-	    desc->fd = FILE_FD_INVALID;
-	    desc->flags = 0;
-	    cq_execute(desc);
-	} else {
-	    EF_FREE(desc);
-	}
-    } else {
-	if (desc->fd != FILE_FD_INVALID) {
-	    do_close(desc->flags, desc->fd);
-	    desc->fd = FILE_FD_INVALID;
-	    desc->flags = 0;
-	}
-	if (desc->read_binp) {
-	    driver_free_binary(desc->read_binp);
-	}
-	EF_FREE(desc);
-    }
-}
-
-/*********************************************************************
- * Driver entry point -> ready_async
- */
-static void 
-file_async_ready(ErlDrvData e, ErlDrvThreadData data)
-{
-    file_descriptor *desc = (file_descriptor*)e;
-    struct t_data *d = (struct t_data *) data;
-    char header[5];		/* result code + count */
-    char resbuf[RESBUFSIZE];	/* Result buffer. */
-#ifdef  USE_VM_PROBES
-    int sched_i1 = d->sched_i1, sched_i2 = d->sched_i2, command = d->command,
-        result_ok = d->result_ok,
-        posix_errno = d->result_ok ? 0 : d->errInfo.posix_errno;
-    DTRACE_CHARBUF(sched_utag, DTRACE_EFILE_BUFSIZ+1);
-
-    sched_utag[0] = '\0';
-    if (DTRACE_ENABLED(efile_drv_return)) {
-        strncpy(sched_utag, d->sched_utag, DTRACE_EFILE_BUFSIZ);
-        sched_utag[DTRACE_EFILE_BUFSIZ] = '\0';
-    }
-#endif  /* USE_VM_PROBES */
-
-    TRACE_C('r');
-
-    if (try_again(desc, d)) {
-        /* DTRACE TODO: what kind of probe makes sense here? */
-	return;
-    }
-
-    switch (d->command)
-    {
-    case FILE_READ:
-	if (!d->result_ok) {
-	    reply_error(desc, &d->errInfo);
-	} else {
-	    size_t available_bytes = 
-		d->c.read.bin_offset + d->c.read.bin_size - desc->read_offset;
-	    if (available_bytes < d->c.read.size) {
-		d->c.read.size = available_bytes;
-	    }
-	    TRACE_C('D');
-	    reply_data(desc, d->c.read.binp, 
-		       desc->read_offset, d->c.read.size);
-	    desc->read_offset += d->c.read.size;
-	    desc->read_size = 
-		d->c.read.bin_offset + d->c.read.bin_size - desc->read_offset;
-	    try_free_read_bin(desc);
-	}
-	free_read(data);
-	break;
-      case FILE_READ_LINE:
-	  /* The read_line structure differs from the read structure.
-	     The data->read_offset and d->c.read_line.read_offset are copies, as are
-	     data->read_size and d->c.read_line.read_size
-             The read_line function does not kniow in advance how large the binary has to be,
-	     why new allocation (but not reallocation of the old binary, for obvious reasons) 
-	     may happen in the worker thread. */
-	if (!d->result_ok) {
-	    reply_error(desc, &d->errInfo);
-	} else {
-	    size_t len = d->c.read_line.nl_pos - d->c.read_line.read_offset;
-	    TRACE_C('L');
-	    reply_data(desc, d->c.read_line.binp, 
-		       d->c.read_line.read_offset, len);
-	    desc->read_offset = d->c.read_line.read_offset + d->c.read_line.nl_skip + len;
-	    desc->read_size = 
-		d->c.read_line.read_size - d->c.read_line.nl_skip - len;
-	    if (desc->read_binp != d->c.read_line.binp) { /* New binary allocated */
-		driver_free_binary(desc->read_binp);
-		desc->read_binp =  d->c.read_line.binp;
-		driver_binary_inc_refc(desc->read_binp);
-	    }
-#if !ALWAYS_READ_LINE_AHEAD
-	    ASSERT(desc->read_bufsize > 0 || desc->read_size == 0);
-	    if (desc->read_bufsize == 0) {
-		desc->read_offset = desc->read_binp->orig_size; /* triggers cleanup */
-	    }
-#endif
-	    try_free_read_bin(desc);
-	}
-	free_read_line(data);
-	break;
-      case FILE_READ_FILE:
-	if (!d->result_ok)
-	    reply_error(desc, &d->errInfo);
-	else {
-	    header[0] = FILE_RESP_ALL_DATA;
-	    TRACE_C('R');
-	    driver_output_binary(desc->port, header, 1,
-				 d->c.read_file.binp,
-				 0, d->c.read_file.offset);
-	}
-	free_read_file(data);
-	break;
-      case FILE_WRITE:
-	  if (d->reply) {
-	      if (! d->result_ok) {
-		  reply_error(desc, &d->errInfo);
-	      } else {
-		  reply_Uint(desc, d->c.writev.reply_size);
-	      }
-	  } else {
-	      if (! d->result_ok) {
-		  desc->write_error = !0;
-		  desc->write_errInfo = d->errInfo;
-	      }
-	  }
-	  free_data(data);
-	  break;
-      case FILE_LSEEK:
-	  if (d->reply) {
-	      if (d->result_ok)
-		  reply_Sint64(desc, d->c.lseek.location);
-	      else
-		  reply_error(desc, &d->errInfo);
-	  }
-	  free_data(data);
-	  break;
-      case FILE_MKDIR:
-      case FILE_RMDIR:
-      case FILE_CHDIR:
-      case FILE_DELETE:
-      case FILE_FDATASYNC:
-      case FILE_FSYNC:
-      case FILE_TRUNCATE:
-      case FILE_LINK:
-      case FILE_SYMLINK:
-      case FILE_RENAME:
-      case FILE_WRITE_INFO:
-      case FILE_FADVISE:
-      case FILE_FALLOCATE:
-	reply(desc, d->result_ok, &d->errInfo);
-	free_data(data);
-	break;
-      case FILE_ALTNAME:
-      case FILE_PWD:
-      case FILE_READLINK:
-        {
-	    int length;
-	    char *resbuf = d->b;
-
-	    if (!d->result_ok)
-		reply_error(desc, &d->errInfo);
-	    else {
-		resbuf[0] = FILE_RESP_FNAME;
-		length = 1+FILENAME_BYTELEN((char*) resbuf+1);
-		TRACE_C('R');
-		driver_output2(desc->port, resbuf, 1, resbuf+1, length-1);
-	    }
-	    free_data(data);
-	    break;
-	}
-      case FILE_OPEN:
-	if (!d->result_ok) {
-	    reply_error(desc, &d->errInfo);
-	} else {
-	    ASSERT(d->is_fd_unused);
-	    desc->fd = d->fd;
-	    desc->flags = d->flags;
-	    d->is_fd_unused = 0;
-	    reply_Uint(desc, d->fd);
-	}
-	free_data(data);
-	break;
-      case FILE_FSTAT:
-      case FILE_LSTAT:
-        {
-	    if (d->result_ok) {
-		resbuf[0] = FILE_RESP_INFO;
-
-		put_int32(d->info.size_high,         &resbuf[1 + ( 0 * 4)]);
-		put_int32(d->info.size_low,          &resbuf[1 + ( 1 * 4)]);
-		put_int32(d->info.type,              &resbuf[1 + ( 2 * 4)]);
-
-		/* Note 64 bit indexing in resbuf here */
-		put_int64(d->info.accessTime,        &resbuf[1 + ( 3 * 4)]);
-		put_int64(d->info.modifyTime,        &resbuf[1 + ( 5 * 4)]);
-		put_int64(d->info.cTime,             &resbuf[1 + ( 7 * 4)]);
-
-		put_int32(d->info.mode,              &resbuf[1 + ( 9 * 4)]);
-		put_int32(d->info.links,             &resbuf[1 + (10 * 4)]);
-		put_int32(d->info.major_device,      &resbuf[1 + (11 * 4)]);
-		put_int32(d->info.minor_device,      &resbuf[1 + (12 * 4)]);
-		put_int32(d->info.inode,             &resbuf[1 + (13 * 4)]);
-		put_int32(d->info.uid,               &resbuf[1 + (14 * 4)]);
-		put_int32(d->info.gid,               &resbuf[1 + (15 * 4)]);
-		put_int32(d->info.access,            &resbuf[1 + (16 * 4)]);
-
-#define RESULT_SIZE (1 + (17 * 4))
-		TRACE_C('R');
-		driver_output2(desc->port, resbuf, RESULT_SIZE, NULL, 0);
-#undef RESULT_SIZE
-	    } else
-		reply_error(desc, &d->errInfo);
-	}
-	free_data(data);
-	break;
-      case FILE_READDIR:
-	if (!d->result_ok) {
-	    reply_error(desc, &d->errInfo);
-	} else {
-	    struct t_readdir_buf *b1 = d->c.read_dir.first_buf;
-	    char   op = FILE_RESP_LFNAME;
-
-	    TRACE_C('R');
-	    ASSERT(b1);
-
-	    while (b1) {
-		struct t_readdir_buf *b2 = b1;
-		char *p = &b1->buf[0];
-		driver_output2(desc->port, p, 1, p + 1, b1->n - 1);
-		b1 = b1->next;
-		EF_FREE(b2);
-	    }
-	    driver_output2(desc->port, &op, 1, NULL, 0);
-    
-	    d->c.read_dir.first_buf = NULL;
-	    d->c.read_dir.last_buf = NULL;
-	}
-	free_readdir(data);
-	break;
-      case FILE_CLOSE:
-	  if (d->reply) {
-	      TRACE_C('K');
-	      reply_ok(desc);
-#ifdef USE_VM_PROBES
-              result_ok = 1;
-#endif
-	  }
-	  free_data(data);
-	  break;
-      case FILE_PWRITEV:
-	  if (!d->result_ok) {
-	      reply_Uint_error(desc, d->c.pwritev.cnt, &d->errInfo);
-	  } else {
-	      reply_Uint(desc, d->c.pwritev.n);
-	  }
-	  free_data(data);
-	  break;
-      case FILE_PREADV:
-	  if (!d->result_ok) {
-	      reply_error(desc, &d->errInfo);
-	  } else {
-	      reply_ev(desc, FILE_RESP_LDATA, &d->c.preadv.eiov);
-	  }
-	  free_preadv(data);
-	  break;
-      case FILE_IPREAD:
-	  if (!d->result_ok) {
-	      reply_error(desc, &d->errInfo);
-	  } else if (!d->c.preadv.eiov.vsize) {
-	      reply_eof(desc);
-	  } else {
-	      reply_ev(desc, FILE_RESP_N2DATA, &d->c.preadv.eiov);
-	  }
-	  free_preadv(data);
-	  break;
-#ifdef HAVE_SENDFILE
-      case FILE_SENDFILE:
-	  if (d->result_ok == -1) {
-	      if (d->errInfo.posix_errno == ECONNRESET ||
-		  d->errInfo.posix_errno == ENOTCONN ||
-		  d->errInfo.posix_errno == EPIPE)
-		  reply_string_error(desc,"closed");
-	      else
-		  reply_error(desc, &d->errInfo);
-	      desc->sendfile_state = not_sending;
-	      free_sendfile(data);
-	  } else if (d->result_ok == 0) {
-	      reply_Sint64(desc, d->c.sendfile.written);
-	      desc->sendfile_state = not_sending;
-	      free_sendfile(data);
-	  } else if (d->result_ok == 1) { /* If we are using select to send the rest of the data */
-	      desc->sendfile_state = sending;
-	      desc->d = d;
-	      driver_select(desc->port, (ErlDrvEvent)(long)d->c.sendfile.out_fd,
-			    ERL_DRV_USE|ERL_DRV_WRITE, 1);
-	  }
-	  break;
-#endif
-      case FILE_CLOSE_ON_PORT_EXIT:
-	  /* See file_stop. However this is never invoked after the port is killed. */
-	  free_data(data);
-	  desc = NULL;
-	  /* This is it for this port, so just send dtrace and return, avoid doing anything to the freed data */
-	  DTRACE6(efile_drv_return, sched_i1, sched_i2, sched_utag,
-		  command, result_ok, posix_errno);
-	  return;
-      default:
-	abort();
-    }
-    DTRACE6(efile_drv_return, sched_i1, sched_i2, sched_utag,
-            command, result_ok, posix_errno);
-    if (desc->write_buffered != 0 && desc->timer_state == timer_idle ) {
-	desc->timer_state = timer_write;
-	driver_set_timer(desc->port, desc->write_delay);
-    }
-    cq_execute(desc);
-
-}
-
-
-/*********************************************************************
- * Driver entry point -> output
- */
-static void 
-file_output(ErlDrvData e, char* buf, ErlDrvSizeT count)
-{
-    file_descriptor* desc = (file_descriptor*)e;
-    Efile_error errInfo;	/* The error codes for the last operation. */
-    Sint fd;			/* The file descriptor for this port, if any,
-				 * -1 if none.
-				 */
-    char* name;			/* Points to the filename in buf. */
-    int command;
-    struct t_data *d = NULL;
-#ifdef  USE_VM_PROBES
-    char *dt_utag = NULL;
-    char *dt_s1 = NULL, *dt_s2 = NULL;
-    Sint64 dt_i1 = 0;
-    Sint64 dt_i2 = 0;
-    Sint64 dt_i3 = 0;
-    Sint64 dt_i4 = 0;
-    dt_private *dt_priv = get_dt_private(0);
-#endif  /* USE_VM_PROBES */
-
-    TRACE_C('o');
-
-    fd  = desc->fd;
-    name = buf+1;
-    command = *(uchar*)buf++;
-
-    switch(command) {
-
-    case FILE_MKDIR:
-    {
-	d = EF_SAFE_ALLOC(sizeof(struct t_data) - 1 + FILENAME_BYTELEN(name) + FILENAME_CHARSIZE);
-	
-	FILENAME_COPY(d->b, name);
-#ifdef USE_VM_PROBES
-	dt_s1 = d->b;
-	dt_utag = name + FILENAME_BYTELEN(name) + FILENAME_CHARSIZE;
-#endif
-	d->command = command;
-	d->invoke = invoke_mkdir;
-	d->free = free_data;
-	d->level = 2;
-	goto done;
-    }
-    case FILE_RMDIR:
-    {
-	d = EF_SAFE_ALLOC(sizeof(struct t_data) - 1 + FILENAME_BYTELEN(name) + FILENAME_CHARSIZE);
-	
-	FILENAME_COPY(d->b, name);
-#ifdef USE_VM_PROBES
-	dt_s1 = d->b;
-	dt_utag = name + FILENAME_BYTELEN(name) + FILENAME_CHARSIZE;
-#endif
-	d->command = command;
-	d->invoke = invoke_rmdir;
-	d->free = free_data;
-	d->level = 2;
-	goto done;
-    }
-    case FILE_DELETE:
-    {
-	d = EF_SAFE_ALLOC(sizeof(struct t_data) - 1 + FILENAME_BYTELEN(name) + FILENAME_CHARSIZE);
-	
-	FILENAME_COPY(d->b, name);
-#ifdef USE_VM_PROBES
-	dt_s1 = d->b;
-	dt_utag = name + FILENAME_BYTELEN(name) + FILENAME_CHARSIZE;
-#endif
-	d->command = command;
-	d->invoke = invoke_delete_file;
-	d->free = free_data;
-	d->level = 2;
-	goto done;
-    }
-    case FILE_RENAME:
-	{
-	    char* new_name;
-	    int namelen = FILENAME_BYTELEN(name)+FILENAME_CHARSIZE;
-	    new_name = name+namelen;
-	    d = EF_SAFE_ALLOC(sizeof(struct t_data) - 1
-			      + namelen
-			      + FILENAME_BYTELEN(new_name) + FILENAME_CHARSIZE);
-	
-	    FILENAME_COPY(d->b, name);
-	    FILENAME_COPY(d->b + namelen, new_name);
-#ifdef USE_VM_PROBES
-	    dt_s1 = d->b;
-	    dt_s2 = d->b + namelen;
-	    dt_utag = buf + namelen + FILENAME_BYTELEN(new_name) + FILENAME_CHARSIZE;
-#endif
-	    d->flags = desc->flags;
-	    d->fd = fd;
-	    d->command = command;
-	    d->invoke = invoke_rename;
-	    d->free = free_data;
-	    d->level = 2;
-	    goto done;
-	}
-    case FILE_CHDIR:
-    {
-	d = EF_SAFE_ALLOC(sizeof(struct t_data) - 1 + FILENAME_BYTELEN(name) + FILENAME_CHARSIZE);
-	
-	FILENAME_COPY(d->b, name);
-#ifdef USE_VM_PROBES
-	dt_s1 = d->b;
-	dt_utag = name + FILENAME_BYTELEN(name) + FILENAME_CHARSIZE;
-#endif
-	d->command = command;
-	d->invoke = invoke_chdir;
-	d->free = free_data;
-	d->level = 2;
-	goto done;
-    }
-    case FILE_PWD:
-        {
-	    d = EF_SAFE_ALLOC(sizeof(struct t_data) - 1 + RESBUFSIZE + 1);
-	
-	    d->drive = *(uchar*)buf;
-#ifdef USE_VM_PROBES
-	    dt_utag = buf + 1;
-#endif
-	    d->command = command;
-	    d->invoke = invoke_pwd;
-	    d->free = free_data;
-	    d->level = 2;
-	    goto done;
-	}
-
-    case FILE_READDIR: 
-	if (sys_info.async_threads > 0)
-	{
-	    d = EF_SAFE_ALLOC(sizeof(struct t_data) - 1 + FILENAME_BYTELEN(name) + 
-			      FILENAME_CHARSIZE);
-	
-	    FILENAME_COPY(d->b, name);
-#ifdef USE_VM_PROBES
-	    dt_s1 = d->b;
-	    dt_utag = name + FILENAME_BYTELEN(name) + FILENAME_CHARSIZE;
-#endif
-	    d->dir_handle = NULL;
-	    d->command = command;
-	    d->invoke = invoke_readdir;
-	    d->free = free_readdir;
-	    d->level = 2;
-	    d->c.read_dir.first_buf = NULL;
-	    d->c.read_dir.last_buf = NULL;
-	    goto done;
-	}
-	else   
-	{
-	    size_t resbufsize;
-	    size_t n = 0, total = 0;
-	    int res = 0;
-	    char resbuf[READDIR_BUFSIZE];
-
-	    EFILE_DIR_HANDLE dir_handle; /* Handle to open directory. */
-
-	    total               = READDIR_BUFSIZE;
-	    errInfo.posix_errno = 0;
-	    dir_handle          = NULL;
-	    resbuf[0]           = FILE_RESP_LFNAME;
-
-#ifdef USE_VM_PROBES
-	    dt_s1 = name;
-	    dt_utag = name + FILENAME_BYTELEN(name) + FILENAME_CHARSIZE;
-#endif
-	    /* Fill the buffer with multiple directory listings before sending it to the
-	     * receiving process. READDIR_CHUNKS is minimum number of files sent to the
-	     * receiver.
-	     * Format for each driver_output2:
-	     * ------------------------------------
-	     * | Type   | Len     | Filename  | ...
-	     * | 1 byte | 2 bytes | Len bytes | ...
-	     * ------------------------------------
-	     */
-
-	    do {
-		n = 1;
-		resbufsize = READDIR_BUFSIZE - n;
-
-		do {
-		    res = efile_readdir(&errInfo, name, &dir_handle, resbuf + n + 2, &resbufsize);
-
-		    if (res) {
-			put_int16((Uint16)resbufsize, resbuf + n);
-			n += 2 + resbufsize;
-			resbufsize = READDIR_BUFSIZE - n;
-		    }
-		} while( res && ((total - n - 2) >= MAXPATHLEN*FILENAME_CHARSIZE));
-
-		if (n > 1) {
-		    driver_output2(desc->port, resbuf, 1, resbuf + 1, n - 1);
-		}
-	    } while(res);
-
-	    if (errInfo.posix_errno != 0) {
-		reply_error(desc, &errInfo);
-		return;
-	    }
-#ifdef USE_VM_PROBES
-	    if (dt_utag != NULL && dt_utag[0] == '\0') {
-                dt_utag = NULL;
-            } 
-
-	    DTRACE11(efile_drv_entry, dt_priv->thread_num, dt_priv->tag,
-		     dt_utag, command, name, dt_s2,
-		     dt_i1, dt_i2, dt_i3, dt_i4, desc->port_str);
-	    DTRACE6(efile_drv_return, dt_priv->thread_num, dt_priv->tag++, 
-		    dt_utag, command, 1, 0);
-#endif
-	    TRACE_C('R');
-	    driver_output2(desc->port, resbuf, 1, NULL, 0);
-	    return;
-	}
-    case FILE_OPEN:
-	{
-	    d = EF_SAFE_ALLOC(sizeof(struct t_data) - 1 + FILENAME_BYTELEN(buf+4) + 
-			      FILENAME_CHARSIZE);
-	
-	    d->flags = get_int32((uchar*)buf);
-	    name = buf+4;
-	    FILENAME_COPY(d->b, name);
-#ifdef USE_VM_PROBES
-	    dt_i1 = d->flags;
-	    dt_s1 = d->b;
-	    dt_utag = name + FILENAME_BYTELEN(d->b) + FILENAME_CHARSIZE;
-#endif
-	    d->command = command;
-	    d->invoke = invoke_open;
-	    d->free = free_data;
-	    d->level = 2;
-	    d->is_fd_unused = 1;
-	    goto done;
-	}
-
-    case FILE_FDATASYNC:
-	{
-	    d = EF_SAFE_ALLOC(sizeof(struct t_data));
-	    
-	    d->fd = fd;
-#ifdef USE_VM_PROBES
-	    dt_utag = name;
-	    dt_i1 = fd;
-#endif
-	    d->command = command;
-	    d->invoke = invoke_fdatasync;
-	    d->free = free_data;
-	    d->level = 2;
-	    goto done;
-	}
-
-    case FILE_FSYNC:
-	{
-	    d = EF_SAFE_ALLOC(sizeof(struct t_data));
-	    
-	    d->fd = fd;
-#ifdef USE_VM_PROBES
-	    dt_utag = name;
-	    dt_i1 = fd;
-#endif
-	    d->command = command;
-	    d->invoke = invoke_fsync;
-	    d->free = free_data;
-	    d->level = 2;
-	    goto done;
-	}
-
-
-    case FILE_FSTAT: 
-    case FILE_LSTAT:
-	{
-	    d = EF_SAFE_ALLOC(sizeof(struct t_data) - 1 + FILENAME_BYTELEN(name) + 
-			      FILENAME_CHARSIZE);
-	    
-	    FILENAME_COPY(d->b, name);
-	    d->fd = fd;
-#ifdef USE_VM_PROBES
-	    dt_utag = name + FILENAME_BYTELEN(d->b) + FILENAME_CHARSIZE;
-	    if (command == FILE_LSTAT) {
-		dt_s1 = d->b;
-	    } else {
-		dt_i1 = fd;
-	    }
-#endif
-	    d->command = command;
-	    d->invoke = invoke_flstat;
-	    d->free = free_data;
-	    d->level = 2;
-	    goto done;
-	}
-	
-    case FILE_TRUNCATE:
-        {
-	    d = EF_SAFE_ALLOC(sizeof(struct t_data));
-	    
-	    d->flags = desc->flags;
-	    d->fd = fd;
-#ifdef USE_VM_PROBES
-	    dt_utag = name;
-	    dt_i1 = fd;
-	    dt_i2 = d->flags;
-#endif
-	    d->command = command;
-	    d->invoke = invoke_truncate;
-	    d->free = free_data;
-	    d->level = 2;
-	    goto done;
-	}
-
-    case FILE_WRITE_INFO:
-	{
-	    d = EF_SAFE_ALLOC(sizeof(struct t_data) - 1
-			      + FILENAME_BYTELEN(buf + 9*4) + FILENAME_CHARSIZE);
-	    
-	    d->info.mode       = get_int32(buf + 0 * 4);
-	    d->info.uid        = get_int32(buf + 1 * 4);
-	    d->info.gid        = get_int32(buf + 2 * 4);
-	    d->info.accessTime = get_int64(buf + 3 * 4);
-	    d->info.modifyTime = get_int64(buf + 5 * 4);
-	    d->info.cTime      = get_int64(buf + 7 * 4);
-
-	    FILENAME_COPY(d->b, buf + 9*4);
-#ifdef USE_VM_PROBES
-	    dt_i1              = d->info.mode;
-	    dt_i2              = d->info.uid;
-	    dt_i3              = d->info.gid;
-	    dt_s1 = d->b;
-	    dt_utag = buf + 9 * 4 + FILENAME_BYTELEN(d->b) + FILENAME_CHARSIZE;
-#endif
-	    d->command = command;
-	    d->invoke = invoke_write_info;
-	    d->free = free_data;
-	    d->level = 2;
-	    goto done;
-	}
-
-    case FILE_READLINK:
-	{
-	    d = EF_SAFE_ALLOC(sizeof(struct t_data) - 1 + 
-			      MAX(RESBUFSIZE, (FILENAME_BYTELEN(name) +  
-					       FILENAME_CHARSIZE))  + 1);
-	    FILENAME_COPY(d->b, name);
-#ifdef USE_VM_PROBES
-	    dt_s1 = d->b;
-	    dt_utag = name + FILENAME_BYTELEN(d->b) + FILENAME_CHARSIZE;
-#endif
-	    d->command = command;
-	    d->invoke = invoke_readlink;
-	    d->free = free_data;
-	    d->level = 2;
-	    goto done;
-	}
-
-    case FILE_ALTNAME:
-	{
-	     d = EF_SAFE_ALLOC(sizeof(struct t_data) - 1 + 
-			       MAX(RESBUFSIZE, (FILENAME_BYTELEN(name) +  
-						FILENAME_CHARSIZE))  + 1);
-	    FILENAME_COPY(d->b, name);
-#ifdef USE_VM_PROBES
-	    dt_s1 = d->b;
-	    dt_utag = name + FILENAME_BYTELEN(d->b) + FILENAME_CHARSIZE;
-#endif
-	    d->command = command;
-	    d->invoke = invoke_altname;
-	    d->free = free_data;
-	    d->level = 2;
-	    goto done;
-	}
-
-
-    case FILE_LINK:
-	{
-	    char* new_name;
-	    int namelen = FILENAME_BYTELEN(name) + FILENAME_CHARSIZE;
-
-	    new_name = name+namelen;
-	    d = EF_SAFE_ALLOC(sizeof(struct t_data) - 1
-			      + namelen
-			      + FILENAME_BYTELEN(new_name) + FILENAME_CHARSIZE);
-	
-	    FILENAME_COPY(d->b, name);
-	    FILENAME_COPY(d->b + namelen, new_name);
-#ifdef USE_VM_PROBES
-	    dt_s1 = d->b;
-	    dt_s2 = d->b + namelen;
-	    dt_utag = buf + namelen + FILENAME_BYTELEN(dt_s2) + FILENAME_CHARSIZE;
-#endif
-	    d->flags = desc->flags;
-	    d->fd = fd;
-	    d->command = command;
-	    d->invoke = invoke_link;
-	    d->free = free_data;
-	    d->level = 2;
-	    goto done;
-	}
-
-    case FILE_SYMLINK:
-	{
-	    char* new_name;
-	    int namelen = FILENAME_BYTELEN(name) + FILENAME_CHARSIZE;
-
-	    new_name = name+namelen;
-	    d = EF_SAFE_ALLOC(sizeof(struct t_data) - 1
-			      + namelen
-			      + FILENAME_BYTELEN(new_name) + FILENAME_CHARSIZE);
-	
-	    FILENAME_COPY(d->b, name);
-	    FILENAME_COPY(d->b + namelen, new_name);
-#ifdef USE_VM_PROBES
-	    dt_s1 = d->b;
-	    dt_s2 = d->b + namelen;
-	    dt_utag = buf + namelen + FILENAME_BYTELEN(dt_s2) + FILENAME_CHARSIZE;
-#endif
-	    d->flags = desc->flags;
-	    d->fd = fd;
-	    d->command = command;
-	    d->invoke = invoke_symlink;
-	    d->free = free_data;
-	    d->level = 2;
-	    goto done;
-	}
-
-    case FILE_FADVISE:
-    {
-        d = EF_SAFE_ALLOC(sizeof(struct t_data));
-
-        d->fd = fd;
-        d->command = command;
-        d->invoke = invoke_fadvise;
-        d->free = free_data;
-        d->level = 2;
-        d->c.fadvise.offset = get_int64((uchar*) buf);
-        d->c.fadvise.length = get_int64(((uchar*) buf) + sizeof(Sint64));
-        d->c.fadvise.advise = get_int32(((uchar*) buf) + 2 * sizeof(Sint64));
-#ifdef USE_VM_PROBES
-        dt_i1 = d->fd;
-        dt_i2 = d->c.fadvise.offset;
-        dt_i3 = d->c.fadvise.length;
-        dt_i4 = d->c.fadvise.advise;
-        dt_utag = buf + 3 * sizeof(Sint64);
-#endif
-        goto done;
-    }
-
-    case FILE_FALLOCATE:
-    {
-        d = EF_SAFE_ALLOC(sizeof(struct t_data));
-
-        d->fd = fd;
-        d->command = command;
-        d->invoke = invoke_fallocate;
-        d->free = free_data;
-        d->level = 2;
-        d->c.fallocate.offset = get_int64((uchar*) buf);
-        d->c.fallocate.length = get_int64(((uchar*) buf) + sizeof(Sint64));
-        goto done;
-    }
-
-    }
-
-    /*
-     * Ignore anything else -- let the caller hang.
-     */
-     
-    return;
-
- done:
-    if (d) {
-#ifdef USE_VM_PROBES
-	d->sched_i1 = dt_priv->thread_num;
-	d->sched_i2 = dt_priv->tag;
-	d->sched_utag[0] = '\0';
-	if (dt_utag != NULL) {
-	    if (dt_utag[0] == '\0') {
-		dt_utag = NULL;
-	    } else {
-		strncpy(d->sched_utag, dt_utag, sizeof(d->sched_utag) - 1);
-		d->sched_utag[sizeof(d->sched_utag) - 1] = '\0';
-	    }
-	}
-	DTRACE11(efile_drv_entry, dt_priv->thread_num, dt_priv->tag++,
-		 dt_utag, command, dt_s1, dt_s2,
-		 dt_i1, dt_i2, dt_i3, dt_i4, desc->port_str);
-#endif
-	cq_enq(desc, d);
-    }
-}
-
-/*********************************************************************
- * Driver entry point -> flush
- */
-static void 
-file_flush(ErlDrvData e) {
-    file_descriptor *desc = (file_descriptor *)e;
-#ifdef DEBUG
-    int r;
-#endif
-#ifdef  USE_VM_PROBES
-    dt_private *dt_priv = get_dt_private(dt_driver_io_worker_base);
-#endif
-
-    TRACE_C('f');
-
-#ifdef HAVE_SENDFILE
-    flush_sendfile(desc, NULL);
-#endif
-
-#ifdef DEBUG
-    r = 
-#endif
-         flush_write(desc, NULL
-#ifdef USE_VM_PROBES
-		     , dt_priv, (desc->d == NULL) ? NULL : desc->d->sched_utag
-#endif
-		     );
-    /* Only possible reason for bad return value is ENOMEM, and 
-     * there is nobody to tell...
-     */
-#ifdef DEBUG
-    ASSERT(r == 0); 
-#endif
-    cq_execute(desc);
-}
-
-
-
-/*********************************************************************
- * Driver entry point -> control
- * Only debug functionality...
- */
-static ErlDrvSSizeT
-file_control(ErlDrvData e, unsigned int command, 
-	     char* buf, ErlDrvSizeT len, char **rbuf, ErlDrvSizeT rlen) {
-    file_descriptor *desc = (file_descriptor *)e;
-    switch (command) {
-    case 'K' :
-	if (rlen < 4) {
-	    *rbuf = EF_ALLOC(4);
-	}
-	(*rbuf)[0] = ((desc->key) >> 24) & 0xFF;
-	(*rbuf)[1] = ((desc->key) >> 16) & 0xFF;
-	(*rbuf)[2] = ((desc->key) >> 8) & 0xFF;
-	(*rbuf)[3] = (desc->key) & 0xFF;
-	return 4;
-    default:
-	return 0;
-    }
-}
-
-/*********************************************************************
- * Driver entry point -> timeout
- */
-static void 
-file_timeout(ErlDrvData e) {
-    file_descriptor *desc = (file_descriptor *)e;
-    enum e_timer timer_state = desc->timer_state;
-#ifdef  USE_VM_PROBES
-    dt_private *dt_priv = get_dt_private(dt_driver_io_worker_base);
-#endif
-
-    TRACE_C('t');
-
-    desc->timer_state = timer_idle;
-    switch (timer_state) {
-    case timer_idle:
-	ASSERT(0);
-	break;
-    case timer_again:
-	ASSERT(desc->invoke);
-	ASSERT(desc->free);
-	driver_async(desc->port, KEY(desc), desc->invoke, desc->d, desc->free);
-	break;
-    case timer_write: {
-#ifdef DEBUG
-	int r = 
-#endif
-	         flush_write(desc, NULL
-#ifdef USE_VM_PROBES
-			     , dt_priv, (desc->d == NULL) ? NULL : desc->d->sched_utag
-#endif
-			     );
-	/* Only possible reason for bad return value is ENOMEM, and 
-	 * there is nobody to tell...
-	 */
-	ASSERT(r == 0); 
-	cq_execute(desc);
-    } break;
-    } /* case */
-}
-
-
-
-/*********************************************************************
- * Driver entry point -> outputv
- */
-static void 
-file_outputv(ErlDrvData e, ErlIOVec *ev) {
-    file_descriptor* desc = (file_descriptor*)e;
-    char command;
-    size_t p, q;
-    int err;
-    struct t_data *d = NULL;
-#ifdef USE_VM_PROBES
-    Sint64 dt_i1 = 0, dt_i2 = 0, dt_i3 = 0;
-    Sint64 dt_i4 = 0;
-    char *dt_utag = NULL;
-    char *dt_s1 = NULL;
-    dt_private *dt_priv = get_dt_private(dt_driver_io_worker_base);
-#endif
-
-    TRACE_C('v');
-
-    p = 0; q = 1;
-    if (! EV_GET_CHAR(ev, &command, &p, &q)) {
-	/* Empty command */
-	reply_posix_error(desc, EINVAL);
-	goto done;
-    }
-    /* 'command' contains the decoded command number,
-     * 'p' and 'q' point out the next byte in the command:
-     * ((char *)ev->iov[q].iov_base) + p;
-     */
-    
-    TRACE_F(("%i", (int) command));
-
-    switch (command) {
-
-    case FILE_CLOSE: {
-#ifdef USE_VM_PROBES
-	dt_utag = EV_CHAR_P(ev, p, q);
-#endif
-	flush_read(desc);
-	if (flush_write_check_error(desc, &err
-#ifdef USE_VM_PROBES
-				    , dt_priv, dt_utag
-#endif
-				    ) < 0) {
-	    reply_posix_error(desc, err);
-	    goto done;
-	}
-	if (desc->fd != FILE_FD_INVALID) {
-	    if (! (d = EF_ALLOC(sizeof(struct t_data)))) {
-		reply_posix_error(desc, ENOMEM);
-	    } else {
-		d->command = command;
-		d->reply = !0;
-		d->fd = desc->fd;
-		d->flags = desc->flags;
-#ifdef USE_VM_PROBES
-		dt_i1 = d->fd;
-		dt_i2 = d->flags;
-#endif
-		d->invoke = invoke_close;
-		d->free = free_data;
-		d->level = 2;
-		cq_enq(desc, d);
-		desc->fd = FILE_FD_INVALID;
-		desc->flags = 0;
-	    }
-	} else {
-	    reply_posix_error(desc, EBADF);
-	}
-    } goto done;
-
-    case FILE_READ: {
-	Uint32 sizeH, sizeL;
-	size_t size, alloc_size;
-
-	if (!EV_GET_UINT32(ev, &sizeH, &p, &q)
-	    || !EV_GET_UINT32(ev, &sizeL, &p, &q)) {
-	    /* Wrong buffer length to contain the read count */
-	    reply_posix_error(desc, EINVAL);
-	    goto done;
-	}
-#ifdef USE_VM_PROBES
-	dt_utag = EV_CHAR_P(ev, p, q);
-#endif
-	if (flush_write_check_error(desc, &err
-#ifdef USE_VM_PROBES
-				    , dt_priv, dt_utag
-#endif
-				    ) < 0) {
-	    reply_posix_error(desc, err);
-	    goto done;
-	}
-#if ALWAYS_READ_LINE_AHEAD
-	if (desc->read_bufsize == 0 && desc->read_binp != NULL && desc->read_size > 0) {
-	    /* We have allocated a buffer for line mode but should not really have a 
-	       read-ahead buffer... */
-	    if (lseek_flush_read(desc, &err
-#ifdef USE_VM_PROBES
-				 , dt_priv, dt_utag
-#endif
-				 ) < 0) {
-		reply_posix_error(desc, err);
-		goto done;
-	    }
-	}
-#endif
-#if SIZEOF_SIZE_T == 4
-	if (sizeH != 0) {
-	    reply_posix_error(desc, EINVAL);
-	    goto done;
-	}
-	size = sizeL;
-#else
-	size = ((size_t)sizeH << 32) | sizeL;
-#endif
-	if ((desc->fd == FILE_FD_INVALID)
-	    || (! (desc->flags & EFILE_MODE_READ)) ) {
-	    reply_posix_error(desc, EBADF);
-	    goto done;
-	}
-	if (size == 0) {
-	    reply_buf(desc, &command, 0);
-	    goto done;
-	}
-	if (desc->read_size >= size) {
-	    /* We already have all data */
-	    TRACE_C('D');
-	    reply_data(desc, desc->read_binp, desc->read_offset, size);
-	    desc->read_offset += size;
-	    desc->read_size -= size;
-	    try_free_read_bin(desc);
-	    goto done;
-	}
-	/* We may have some of the data 
-	 */
-	/* Justification for the following strange formula:
-	 * If the read request is for such a large block as more than 
-	 * half the buffer size it may lead to a lot of unnecessary copying, 
-	 * since the tail of the old buffer is copied to the head of the
-	 * new, and if the tail is almost half the buffer it is a lot
-	 * to copy. Therefore allocate the exact amount needed in 
-	 * this case, giving no lingering tail. */
-	alloc_size = 
-	    size > (desc->read_bufsize>>1) ? 
-	    size : desc->read_bufsize;
-	if (! desc->read_binp) {
-	    /* Need to allocate a new binary for the result */
-	    if (! (desc->read_binp = driver_alloc_binary(alloc_size))) {
-		reply_posix_error(desc, ENOMEM);
-		goto done;
-	    }
-	} else {
-	    /* We already have a buffer */
-	    if (desc->read_binp->orig_size - desc->read_offset < size) {
-		/* Need to allocate a new binary for the result */
-		ErlDrvBinary *binp;
-		if (! (binp = driver_alloc_binary(alloc_size))) {
-		    reply_posix_error(desc, ENOMEM);
-		    goto done;
-		}
-		/* Move data we already have to the new binary */
-		sys_memcpy(binp->orig_bytes, 
-			   desc->read_binp->orig_bytes + desc->read_offset,
-			   desc->read_size);
-		driver_free_binary(desc->read_binp);
-		desc->read_offset = 0;
-		desc->read_binp = binp;
-	    }
-	} 
-	if (! (d = EF_ALLOC(sizeof(struct t_data)))) {
-	    reply_posix_error(desc, ENOMEM);
-	    goto done;
-	}
-	d->command = command;
-	d->reply = !0;
-	d->fd = desc->fd;
-	d->flags = desc->flags;
-	d->c.read.binp = desc->read_binp;
-	d->c.read.bin_offset = desc->read_offset + desc->read_size;
-	d->c.read.bin_size = desc->read_binp->orig_size - d->c.read.bin_offset;
-	d->c.read.size = size;
-#ifdef USE_VM_PROBES
-	dt_i1 = d->fd;
-	dt_i2 = d->flags;
-	dt_i3 = d->c.read.size;
-#endif
-	driver_binary_inc_refc(d->c.read.binp);
-	d->invoke = invoke_read;
-	d->free = free_read;
-	d->level = 1;
-	cq_enq(desc, d);
-    } goto done; /* case FILE_READ: */
-
-    case FILE_READ_LINE: {
-	/*
-	 * Icky little creature... We do mostly as ordinary file read, but with a few differences.
-	 * 1) We have to scan for proper newline sequence if there is a buffer already, we cannot know 
-	 *    in advance if the buffer contains a whole line without scanning.
-	 * 2) We do not know how large the buffer needs to be in advance. We give a default buffer,
-	 *    but the worker may need to allocate a new one. Freeing the old and rereferencing a newly 
-	 *    allocated binary + dealing with offsets and lengts are done in file_async ready
-	 *    for this OP.
-	 */
-#ifdef USE_VM_PROBES
-	dt_utag = EV_CHAR_P(ev, p, q);
-#endif
-	if (flush_write_check_error(desc, &err
-#ifdef USE_VM_PROBES
-				    , dt_priv, dt_utag
-#endif
-				    ) < 0) {
-	    reply_posix_error(desc, err);
-	    goto done;
-	}
-	if (ev->size != 1
-#ifdef USE_VM_PROBES
-	    + FILENAME_BYTELEN(dt_utag) + FILENAME_CHARSIZE
-#endif
-	    ) {
-	    /* Wrong command length */
-	    reply_posix_error(desc, EINVAL);
-	    goto done;
-	}
-	if ((desc->fd == FILE_FD_INVALID)
-	    || (! (desc->flags & EFILE_MODE_READ)) ) {
-	    reply_posix_error(desc, EBADF);
-	    goto done;
-	}
-	if (desc->read_size > 0) {
-	    /* look for '\n' in what we'we already got */
-	    void *nl_ptr = memchr(desc->read_binp->orig_bytes + desc->read_offset,'\n',desc->read_size);
-	    if (nl_ptr != NULL) {
-		/* If found, we're done */
-		int skip = 0;
-		size_t size = ((char *) nl_ptr) - 
-		    ((char *) (desc->read_binp->orig_bytes + desc->read_offset)) + 1;
-		if (size > 1 &&
-		    *(((char *) nl_ptr) - 1) == '\r') {
-		    *(((char *) nl_ptr) - 1) = '\n';		    
-		    skip = 1;
-		    --size;
-		} 
-		reply_data(desc, desc->read_binp, desc->read_offset, size);
-		desc->read_offset += (size + skip);
-		desc->read_size -= (size + skip);
-		try_free_read_bin(desc);
-		goto done;
-	    }
-	}
-	/* Now, it's up to the thread to work out the need for more buffers and such, it's
-	   no use doing it in this thread as we do not have the information required anyway. 
-	   Even a NULL buffer could be handled by the thread, but code is simplified by us 
-	   allocating it */
-	if (! desc->read_binp) {
-	    int alloc_size = (desc->read_bufsize > DEFAULT_LINEBUF_SIZE) ? desc->read_bufsize : 
-		DEFAULT_LINEBUF_SIZE;
-	    /* Allocate a new binary for the result */
-	    if (! (desc->read_binp = driver_alloc_binary(alloc_size))) {
-		reply_posix_error(desc, ENOMEM);
-		goto done;
-	    }
-	}	
-	if (! (d = EF_ALLOC(sizeof(struct t_data)))) {
-	    reply_posix_error(desc, ENOMEM);
-	    goto done;
-	}
-
-	d->command = command;
-	d->reply = !0;
-	d->fd = desc->fd;
-	d->flags = desc->flags;
-	d->c.read_line.binp = desc->read_binp;
-	d->c.read_line.read_offset = desc->read_offset;
-	d->c.read_line.read_size = desc->read_size;
-#ifdef USE_VM_PROBES
-	dt_i1 = d->fd;
-	dt_i2 = d->flags;
-	dt_i3 = d->c.read_line.read_offset;
-#endif
-#if !ALWAYS_READ_LINE_AHEAD
-	d->c.read_line.read_ahead = (desc->read_bufsize > 0);
-#ifdef USE_VM_PROBES
-	dt_i4 = d->c.read_line.read_ahead;
-#endif
-#endif 
-	driver_binary_inc_refc(d->c.read.binp);
-	d->invoke = invoke_read_line;
-	d->free = free_read_line;
-	d->level = 1;
-	cq_enq(desc, d);
-    } goto done;
-    case FILE_WRITE: { /* Dtrace: The dtrace user tag is not last in message, 
-			  but follows the message tag directly. 
-			  This is handled specially in prim_file.erl */
-	ErlDrvSizeT skip = 1;
-	ErlDrvSizeT size = ev->size - skip;
-
-#ifdef USE_VM_PROBES
-	dt_utag = EV_CHAR_P(ev, p, q);
-	skip += FILENAME_BYTELEN(dt_utag) + FILENAME_CHARSIZE;
-	size = ev->size - skip;
-#endif
-	if (lseek_flush_read(desc, &err
-#ifdef USE_VM_PROBES
-			     , dt_priv, dt_utag
-#endif
-			     ) < 0) {
-	    reply_posix_error(desc, err);
-	    goto done;
-	}
-	if (! (desc->flags & EFILE_MODE_WRITE)) {
-	    reply_posix_error(desc, EBADF);
-	    goto done;
-	}
-	if (size == 0) {
-	    reply_Uint(desc, size);
-	    goto done;
-	}
-	MUTEX_LOCK(desc->q_mtx);
-	if (driver_enqv(desc->port, ev, skip)) {
-	    MUTEX_UNLOCK(desc->q_mtx);
-	    reply_posix_error(desc, ENOMEM);
-	    goto done;
-	}
-	desc->write_buffered += size;
-	if (desc->write_buffered < desc->write_bufsize) {
-	    MUTEX_UNLOCK(desc->q_mtx);
-	    reply_Uint(desc, size);
-	    if (desc->timer_state == timer_idle) {
-		desc->timer_state = timer_write;
-		driver_set_timer(desc->port, desc->write_delay);
-	    }
-	} else {
-	    if ((d = async_write(desc, &err, !0, size
-#ifdef USE_VM_PROBES
-				 , &dt_i1, &dt_i2, &dt_i3
-#endif
-				 )) == NULL) {
-		MUTEX_UNLOCK(desc->q_mtx);
-		reply_posix_error(desc, err);
-		goto done;
-	    } else {
-		MUTEX_UNLOCK(desc->q_mtx);
-	    }
-	}
-    } goto done; /* case FILE_WRITE */
-
-    case FILE_PWRITEV: { /* Dtrace: The dtrace user tag is not last in message, 
-			   but follows the message tag directly. 
-			   This is handled specially in prim_file.erl */
-	Uint32 i, j, n; 
-	size_t total;
-#ifdef USE_VM_PROBES
-	char dt_tmp;
-	int dt_utag_bytes = 1;
-
-	dt_utag = EV_CHAR_P(ev, p, q);
-	/* This will work for UTF-8, but not for UTF-16 - extra reminder here */
-#ifdef FILENAMES_16BIT 
-#error 16bit characters in filenames and dtrace in combination is not supported.
-#endif
-	while (EV_GET_CHAR(ev, &dt_tmp, &p, &q) && dt_tmp != '\0') {
-	    dt_utag_bytes++;
-	}
-#endif
-	if (ev->size < 1+4
-#ifdef USE_VM_PROBES
-	    + dt_utag_bytes
-#endif
-	    || !EV_GET_UINT32(ev, &n, &p, &q)) {
-	    /* Buffer too short to contain even the number of pos/size specs */
-	    reply_Uint_posix_error(desc, 0, EINVAL);
-	    goto done;
-	}
-	if (lseek_flush_read(desc, &err
-#ifdef USE_VM_PROBES
-			     , dt_priv, dt_utag
-#endif
-			     ) < 0) {
-	    reply_Uint_posix_error(desc, 0, err);
-	    goto done;
-	}
-	if (flush_write_check_error(desc, &err
-#ifdef USE_VM_PROBES
-				    , dt_priv, dt_utag
-#endif
-				    ) < 0) {
-	    reply_Uint_posix_error(desc, 0, err);
-	    goto done;
-	}
-	if (n == 0) {
-	    /* Trivial case - nothing to write */
-	    if (ev->size != 1+4) {
-		reply_posix_error(desc, err);
-	    } else {
-		reply_Uint(desc, 0);
-	    }
-	    goto done;
-	}
-	if (ev->size < 1+4+8*(2*n)
-#ifdef USE_VM_PROBES
-	    + dt_utag_bytes
-#endif
-	    ) {
-	    /* Buffer too short to contain even the pos/size specs */
-	    reply_Uint_posix_error(desc, 0, EINVAL);
-	    goto done;
-	}
-	d = EF_ALLOC(sizeof(struct t_data) 
-		     + (n * sizeof(struct t_pbuf_spec)));
-	if (! d) {
-	    reply_Uint_posix_error(desc, 0, ENOMEM);
-	    goto done;
-	}
-	d->command = command;
-	d->reply = !0;
-	d->fd = desc->fd;
-	d->flags = desc->flags;
-#ifdef USE_VM_PROBES
-	dt_i1 = d->fd;
-	dt_i2 = d->flags;
-#endif
-	d->c.pwritev.port = desc->port;
-	d->c.pwritev.q_mtx = desc->q_mtx;
-	d->c.pwritev.n = n;
-	d->c.pwritev.cnt = 0;
-	total = 0;
-	j = 0;
-	/* Create pos/size specs in the thread data structure
-	 * for all non-zero size binaries. Calculate total size.
-	 */
-	for(i = 0; i < n; i++) {
-	    Uint32 sizeH, sizeL;
-	    size_t size;
-	    if (   !EV_GET_SINT64(ev, &d->c.pwritev.specs[i].offset, &p, &q)
-		|| !EV_GET_UINT32(ev, &sizeH, &p, &q)
-		|| !EV_GET_UINT32(ev, &sizeL, &p, &q)) {
-		/* Misalignment in buffer */
-		reply_Uint_posix_error(desc, 0, EINVAL);
-		EF_FREE(d);
-		goto done;
-	    }
-#if SIZEOF_SIZE_T == 4
-	    if (sizeH != 0) {
-		reply_Uint_posix_error(desc, 0, EINVAL);
-		EF_FREE(d);
-		goto done;
-	    }
-	    size = sizeL;
-#else
-	    size = ((size_t)sizeH<<32) | sizeL;
-#endif
-	    if (size > 0) {
-		total += size;
-		d->c.pwritev.specs[j].size = size;
-		j++;
-	    }
-	}
-	d->c.pwritev.size = total;
-#ifdef USE_VM_PROBES
-	dt_i3 = d->c.pwritev.size;
-#endif
-	if (j == 0) {
-	    /* Trivial case - nothing to write */
-	    EF_FREE(d);
-	    reply_Uint(desc, 0);
-	} else {
-	    ErlDrvSizeT skip = 1 + 4 + 8 * (2*n) 
-#ifdef USE_VM_PROBES
-		+ dt_utag_bytes
-#endif
-		;
-	    if (skip + total != ev->size) {
-		/* Actual amount of data does not match 
-		 * total of all pos/size specs
-		 */
-		EF_FREE(d);
-		reply_Uint_posix_error(desc, 0, EINVAL);
-	    } else {
-		/* Enqueue the data */
-		MUTEX_LOCK(desc->q_mtx);
-		driver_enqv(desc->port, ev, skip);
-		MUTEX_UNLOCK(desc->q_mtx);
-		/* Execute the command */
-		d->invoke = invoke_pwritev;
-		d->free = free_data;
-		d->level = 1;
-		cq_enq(desc, d);
-	    }
-	}
-    } goto done; /* case FILE_PWRITEV: */
-
-    case FILE_PREADV: { /* Dtrace: The dtrace user tag is not last in message, 
-			   but follows the message tag directly. 
-			   This is handled specially in prim_file.erl */
-	register void * void_ptr;
-	Uint32 i, n;
-	ErlIOVec *res_ev;
-#ifdef USE_VM_PROBES
-	char dt_tmp;
-	int dt_utag_bytes = 1;
-	/* This will work for UTF-8, but not for UTF-16 - extra reminder here */
-#ifdef FILENAMES_16BIT 
-#error 16bit characters in filenames and dtrace in combination is not supported.
-#endif
-	dt_utag = EV_CHAR_P(ev, p, q);
-	while (EV_GET_CHAR(ev, &dt_tmp, &p, &q) && dt_tmp != '\0') {
-	    dt_utag_bytes++;
-	}
-#endif
-	if (lseek_flush_read(desc, &err
-#ifdef USE_VM_PROBES
-			     , dt_priv, dt_utag
-#endif
-			     ) < 0) {
-	    reply_posix_error(desc, err);
-	    goto done;
-	}
-	if (flush_write_check_error(desc, &err
-#ifdef USE_VM_PROBES
-				    , dt_priv, dt_utag
-#endif
-				    ) < 0) {
-	    reply_posix_error(desc, err);
-	    goto done;
-	}
-	if (ev->size < 1+8
-#ifdef USE_VM_PROBES
-	    + dt_utag_bytes
-#endif
-	    || !EV_GET_UINT32(ev, &n, &p, &q)
-	    || !EV_GET_UINT32(ev, &n, &p, &q)) {
-	    /* Buffer too short to contain even the number of pos/size specs */
-	    reply_posix_error(desc, EINVAL);
-	    goto done;
-	}
-	if (ev->size < 1+8+8*(2*n)
-#ifdef USE_VM_PROBES
-	    + dt_utag_bytes
-#endif
-	    ) {
-	    /* Buffer wrong length to contain the pos/size specs */
-	    reply_posix_error(desc, EINVAL);
-	    goto done;
-	}
-	/* Create the thread data structure with the contained ErlIOVec 
-	 * and corresponding binaries for the response 
-	 */
-	d = EF_ALLOC(sizeof(*d)
-		     + (n * sizeof(*d->c.preadv.offsets))
-		     + ((1+n) * (sizeof(*res_ev->iov)
-				 + sizeof(*res_ev->binv))));
-	if (! d) {
-	    reply_posix_error(desc, ENOMEM);
-	    goto done;
-	}
-	d->command = command;
-	d->reply = !0;
-	d->fd = desc->fd;
-	d->flags = desc->flags;
-#ifdef USE_VM_PROBES
-	dt_i1 = d->fd;
-	dt_i2 = d->flags;
-#endif
-	d->c.preadv.n = n;
-	d->c.preadv.cnt = 0;
-	d->c.preadv.size = 0;
-	res_ev = &d->c.preadv.eiov;
-	/* XXX possible alignment problems here for weird machines */
-	res_ev->vsize = 1+d->c.preadv.n;
-	res_ev->iov = void_ptr = &d->c.preadv.offsets[d->c.preadv.n];
-	res_ev->binv = void_ptr = &res_ev->iov[res_ev->vsize];
-	/* Read in the pos/size specs and allocate binaries for the results */
-	for (i = 1; i < 1+n; i++) {
-	    Uint32 sizeH, sizeL;
-	    size_t size;
-	    if (   !EV_GET_SINT64(ev, &d->c.preadv.offsets[i-1], &p, &q)
-		|| !EV_GET_UINT32(ev, &sizeH, &p, &q)
-		|| !EV_GET_UINT32(ev, &sizeL, &p, &q)) {
-		reply_posix_error(desc, EINVAL);
-		break;
-	    }
-#if SIZEOF_SIZE_T == 4
-	    if (sizeH != 0) {
-		reply_posix_error(desc, EINVAL);
-		break;
-	    }
-	    size = sizeL;
-#else
-	    size = ((size_t)sizeH<<32) | sizeL;
-#endif
-#ifdef USE_VM_PROBES
-	    dt_i3 += size;
-#endif
-	    if (! (res_ev->binv[i] = driver_alloc_binary(size))) {
-		reply_posix_error(desc, ENOMEM);
-		break;
-	    } else {
-		res_ev->iov[i].iov_len  = size;
-		res_ev->iov[i].iov_base = res_ev->binv[i]->orig_bytes;
-	    }
-	}
-	if (i < 1+n) {
-	    for (i--; i > 0; i--) {
-		driver_free_binary(res_ev->binv[i]);
-	    }
-	    EF_FREE(d);
-	    goto done;
-	}
-	/* Allocate the header binary (index 0) */
-	res_ev->binv[0] = driver_alloc_binary(4+4+8*n);
-	if (! res_ev->binv[0]) {
-	    reply_posix_error(desc, ENOMEM);
-	    for (i = 1; i < 1+n; i++) {
-		driver_free_binary(res_ev->binv[i]);
-	    }
-	    EF_FREE(d);
-	    goto done;
-	}
-	res_ev->iov[0].iov_len = 4+4+8*n;
-	res_ev->iov[0].iov_base = res_ev->binv[0]->orig_bytes;
-	/* Fill in the number of buffers in the header */
-	put_int32(0, res_ev->iov[0].iov_base);
-	put_int32(n, (char *)(res_ev->iov[0].iov_base) + 4);
-	/**/
-	res_ev->size = res_ev->iov[0].iov_len;
-	if (n == 0) {
-	    /* Trivial case - nothing to read */
-	    reply_ev(desc, FILE_RESP_LDATA, res_ev);
-	    free_preadv(d);
-	    goto done;
-	} else {
-	    d->invoke = invoke_preadv;
-	    d->free = free_preadv;
-	    d->level = 1;
-	    cq_enq(desc, d);
-	}
-    } goto done; /* case FILE_PREADV: */
-
-    case FILE_LSEEK: {
-	Sint64 offset;		/* Offset for seek */
-	Uint32 origin;		/* Origin of seek. */
-
-	if (ev->size < 1+8+4
-	    || !EV_GET_SINT64(ev, &offset, &p, &q)
-	    || !EV_GET_UINT32(ev, &origin, &p, &q)) {
-	    /* Wrong length of buffer to contain offset and origin */
-	    reply_posix_error(desc, EINVAL);
-	    goto done;
-	}
-#ifdef USE_VM_PROBES
-	dt_utag = EV_CHAR_P(ev, p, q);
-#endif
-	if (lseek_flush_read(desc, &err
-#ifdef USE_VM_PROBES
-			     , dt_priv, dt_utag
-#endif
-			     ) < 0) {
-	    reply_posix_error(desc, err);
-	    goto done;
-	}
-	if (flush_write_check_error(desc, &err
-#ifdef USE_VM_PROBES
-				    , dt_priv, dt_utag
-#endif
-				    ) < 0) {
-	    reply_posix_error(desc, err);
-	    goto done;
-	}
-	if ((d = async_lseek(desc, &err, !0, offset, origin
-#ifdef USE_VM_PROBES
-			     , &dt_i1, &dt_i2, &dt_i3
-#endif
-			     )) == NULL) {
-	    reply_posix_error(desc, err);
-	    goto done;
-	}
-    } goto done;
-
-    case FILE_READ_FILE: {
-	char *filename;
-	if (ev->size < 1+1) {
-	    /* Buffer contains empty name */
-	    reply_posix_error(desc, ENOENT);
-	    goto done;
-	}
-#ifndef USE_VM_PROBES
-	/* In the dtrace case, the iov has an extra element, the dtrace utag - we will need 
-	   another test to see that
-	   the filename is in a single buffer: */
-	if (ev->size-1 != ev->iov[q].iov_len-p) {
-	    /* Name not in one single buffer */
-	    reply_posix_error(desc, EINVAL);
-	    goto done;
-	}
-#else
-	if (((byte *)ev->iov[q].iov_base)[ev->iov[q].iov_len-1] != '\0') {
-	    /* Name not in one single buffer */
-	    reply_posix_error(desc, EINVAL);
-	    goto done;
-	}	
-#endif
-	filename = EV_CHAR_P(ev, p, q);
-	d = EF_ALLOC(sizeof(struct t_data) -1 + FILENAME_BYTELEN(filename) + FILENAME_CHARSIZE);
-	if (! d) {
-	    reply_posix_error(desc, ENOMEM);
-	    goto done;
-	}
-	d->command = command;
-	d->reply = !0;
-	/* Copy name */
-	FILENAME_COPY(d->b, filename);
-#ifdef USE_VM_PROBES
-	{
-	    char dt_tmp;
-
-	    /* This will work for UTF-8, but not for UTF-16 - extra reminder here */
-#ifdef FILENAMES_16BIT 
-#error 16bit characters in filenames and dtrace in combination is not supported.
-#endif
-	    while (EV_GET_CHAR(ev, &dt_tmp, &p, &q) && dt_tmp != '\0') 
-		;
-	    dt_s1 = d->b;
-	    dt_utag = EV_CHAR_P(ev, p, q);
-	}
-#endif
-	d->c.read_file.binp = NULL;
-	d->invoke = invoke_read_file;
-	d->free = free_read_file;
-	d->level = 2;
-	cq_enq(desc, d);
-    } goto done;
-
-    case FILE_IPREAD: {
-	/* This operation cheets by using invoke_preadv() and free_preadv()
-	 * plus its own invoke_ipread. Therefore the result format is 
-	 * a bit awkward - the header binary contains one extra 64 bit
-	 * field that invoke_preadv() fortunately ignores,
-	 * and the first 64 bit field does not contain the number of 
-	 * data binaries which invoke_preadv() also ignores.
-	 */
-	register void * void_ptr;
-	char mode;
-	Sint64 hdr_offset;
-	Uint32 max_size;
-	ErlIOVec *res_ev;
-	int vsize;
-	if (! EV_GET_CHAR(ev, &mode, &p, &q)) {
-	    /* Empty command */
-	    reply_posix_error(desc, EINVAL);
-	    goto done;
-	}
-	if (mode != IPREAD_S32BU_P32BU) {
-	    reply_posix_error(desc, EINVAL);
-	    goto done;
-	}
-	if (ev->size < 1+1+8+4
-	    || !EV_GET_SINT64(ev, &hdr_offset, &p, &q)
-	    || !EV_GET_UINT32(ev, &max_size, &p, &q)) {
-	    /* Buffer too short to contain 
-	     * the header offset and max size spec */
-	    reply_posix_error(desc, EINVAL);
-	    goto done;
-	}
-#ifdef USE_VM_PROBES
-	dt_utag = EV_CHAR_P(ev, p, q);
-#endif
-	if (lseek_flush_read(desc, &err
-#ifdef USE_VM_PROBES
-			     , dt_priv, dt_utag
-#endif
-			     ) < 0) {
-	    reply_posix_error(desc, err);
-	    goto done;
-	}
-	if (flush_write_check_error(desc, &err
-#ifdef USE_VM_PROBES
-				    , dt_priv, dt_utag
-#endif
-				    ) < 0) {
-	    reply_posix_error(desc, err);
-	    goto done;
-	}
-	/* Create the thread data structure with the contained ErlIOVec 
-	 * and corresponding binaries for the response 
-	 */
-	vsize = 2;
-	d = EF_ALLOC(sizeof(*d) + 
-		     vsize*(sizeof(*res_ev->iov) + sizeof(*res_ev->binv)));
-	if (! d) {
-	    reply_posix_error(desc, ENOMEM);
-	    goto done;
-	}
-	d->command = command;
-	d->reply = !0;
-	d->fd = desc->fd;
-	d->flags = desc->flags;
-	d->c.preadv.offsets[0] = hdr_offset;
-	d->c.preadv.size = max_size;
-#ifdef USE_VM_PROBES
-	dt_i1 = d->fd;
-	dt_i2 = d->flags;
-	dt_i3 = d->c.preadv.offsets[0];
-	dt_i4 = d->c.preadv.size;
-#endif
-	res_ev = &d->c.preadv.eiov;
-	/* XXX possible alignment problems here for weird machines */
-	res_ev->iov = void_ptr = d + 1;
-	res_ev->binv = void_ptr = res_ev->iov + vsize;
-	res_ev->size = 0;
-	res_ev->vsize = 0;
-	d->invoke = invoke_ipread;
-	d->free = free_preadv;
-	d->level = 1;
-	cq_enq(desc, d);
-    } goto done; /* case FILE_IPREAD: */
-
-    case FILE_SETOPT: {
-	char opt;
-
-	if (ev->size < 1+1
-	    || !EV_GET_CHAR(ev, &opt, &p, &q)) {
-	    /* Buffer too short to contain even the option type */
-	    reply_posix_error(desc, EINVAL);
-	    goto done;
-	}
-#ifdef USE_VM_PROBES
-	dt_i1 = opt;
-	dt_utag = EV_CHAR_P(ev, p, q);
-#endif
-	switch (opt) {
-	case FILE_OPT_DELAYED_WRITE: {
-	    Uint32 sizeH, sizeL, delayH, delayL;
-	    if (ev->size != 1+1+4*sizeof(Uint32)
-#ifdef USE_VM_PROBES
-		+ FILENAME_BYTELEN(dt_utag) + FILENAME_CHARSIZE
-#endif
-		|| !EV_GET_UINT32(ev, &sizeH, &p, &q)
-		|| !EV_GET_UINT32(ev, &sizeL, &p, &q)
-		|| !EV_GET_UINT32(ev, &delayH, &p, &q)
-		|| !EV_GET_UINT32(ev, &delayL, &p, &q)) {
-		/* Buffer has wrong length to contain the option values */
-		reply_posix_error(desc, EINVAL);
-		goto done;
-	    }
-#if SIZEOF_SIZE_T == 4
-	    if (sizeH != 0) {
-		reply_posix_error(desc, EINVAL);
-		goto done;
-	    }
-	    desc->write_bufsize = sizeL;
-#else
-	    desc->write_bufsize = ((size_t)sizeH << 32) | sizeL;
-#endif
-#if SIZEOF_LONG == 4
-	    if (delayH != 0) {
-		reply_posix_error(desc, EINVAL);
-		goto done;
-	    }
-	    desc->write_delay = delayL;
-#else
-	    desc->write_delay = ((unsigned long)delayH << 32) | delayL;
-#endif
-#ifdef USE_VM_PROBES
-	    dt_i2 = desc->write_delay;
-#endif
-	    TRACE_C('K');
-	    reply_ok(desc);
-	} goto done;
-	case FILE_OPT_READ_AHEAD: {
-	    Uint32 sizeH, sizeL;
-	    if (ev->size != 1+1+2*sizeof(Uint32)
-#ifdef USE_VM_PROBES
-		+ FILENAME_BYTELEN(dt_utag)+FILENAME_CHARSIZE
-#endif
-		|| !EV_GET_UINT32(ev, &sizeH, &p, &q)
-		|| !EV_GET_UINT32(ev, &sizeL, &p, &q)) {
-		/* Buffer has wrong length to contain the option values */
-		reply_posix_error(desc, EINVAL);
-		goto done;
-	    }
-#if SIZEOF_SIZE_T == 4
-	    if (sizeH != 0) {
-		reply_posix_error(desc, EINVAL);
-		goto done;
-	    }
-	    desc->read_bufsize = sizeL;
-#else
-	    desc->read_bufsize = ((size_t)sizeH << 32) | sizeL;
-#endif
-#ifdef USE_VM_PROBES
-	    dt_i2 = desc->read_bufsize;
-#endif
-	    TRACE_C('K');
-	    reply_ok(desc);
-	} goto done;
-	default:
-	    reply_posix_error(desc, EINVAL);
-	    goto done;
-	} /* case FILE_OPT_DELAYED_WRITE: */
-    } ASSERT(0); goto done; /* case FILE_SETOPT: */
-
-    case FILE_SENDFILE: {
-
-#ifdef HAVE_SENDFILE
-        struct t_data *d;
-	Uint32 out_fd, offsetH, offsetL, hd_len, tl_len;
-	Uint64 nbytes;
-	char flags;
-
-	if (ev->size < 1 + 7 * sizeof(Uint32) + sizeof(char)
-		|| !EV_GET_UINT32(ev, &out_fd, &p, &q)
-		|| !EV_GET_CHAR(ev, &flags, &p, &q)
-		|| !EV_GET_UINT32(ev, &offsetH, &p, &q)
-		|| !EV_GET_UINT32(ev, &offsetL, &p, &q)
-		|| !EV_GET_UINT64(ev, &nbytes, &p, &q)
-		|| !EV_GET_UINT32(ev, &hd_len, &p, &q)
-		|| !EV_GET_UINT32(ev, &tl_len, &p, &q)) {
-	    /* Buffer has wrong length to contain all the needed values */
-	    reply_posix_error(desc, EINVAL);
-	    goto done;
-	}
-
-	if (hd_len != 0 || tl_len != 0) {
-	    /* We do not allow header, trailers */
-	    reply_posix_error(desc, EINVAL);
-	    goto done;
-	}
-
-	
-	if (flags & SENDFILE_FLGS_USE_THREADS && !THRDS_AVAILABLE) {
-	    /* We do not allow use_threads flag on a system where
-	       no threads are available. */
-	    reply_posix_error(desc, EINVAL);
-	    goto done;
-	}
-
-	d = EF_SAFE_ALLOC(sizeof(struct t_data));
-	d->fd = desc->fd;
-	d->command = command;
-	d->invoke = invoke_sendfile;
-	d->free = free_sendfile;
-	d->flags = flags;
-	d->level = 2;
-
-	d->c.sendfile.out_fd = (int) out_fd;
-	d->c.sendfile.written = 0;
-	d->c.sendfile.port = desc->port;
-	d->c.sendfile.q_mtx = desc->q_mtx;
-
-    #if SIZEOF_OFF_T == 4
-	if (offsetH != 0) {
-	    reply_posix_error(desc, EINVAL);
-	    goto done;
-	}
-	d->c.sendfile.offset = (off_t) offsetL;
-    #else
-	d->c.sendfile.offset = ((off_t) offsetH << 32) | offsetL;
-    #endif
-
-	d->c.sendfile.nbytes = nbytes;
-
-	if (USE_THRDS_FOR_SENDFILE(d)) {
-	    SET_BLOCKING(d->c.sendfile.out_fd);
-	} else {
-	    /**
-	     * Write a place holder to queue in order to force file_flush
-	     * to be called before the driver is closed.
-	     */
-	    char tmp[1] = "";
-	    MUTEX_LOCK(d->c.sendfile.q_mtx);
-	    if (driver_enq(d->c.sendfile.port, tmp, 1)) {
-	        MUTEX_UNLOCK(d->c.sendfile.q_mtx);
-		reply_posix_error(desc, ENOMEM);
-		goto done;
-	    }
-	    MUTEX_UNLOCK(d->c.sendfile.q_mtx);
-	}
-
-	cq_enq(desc, d);
-#else
-	reply_posix_error(desc, ENOTSUP);
-#endif
-	goto done;
-        } /* case FILE_SENDFILE: */
-
-    } /* switch(command) */
-
-    if (lseek_flush_read(desc, &err
-#ifdef USE_VM_PROBES
-			 , dt_priv, dt_utag
-#endif
-			 ) < 0) {
-	reply_posix_error(desc, err);
-	goto done;
-    }
-    if (flush_write_check_error(desc, &err
-#ifdef USE_VM_PROBES
-				, dt_priv, dt_utag
-#endif
-				) < 0) {
-	reply_posix_error(desc, err);
-	goto done;
-    } else {
-	/* Flatten buffer and send it to file_output(desc, buf, len) */
-	int len = ev->size;
-	char *buf = EF_ALLOC(len);
-	if (! buf) {
-	    reply_posix_error(desc, ENOMEM);
-	    goto done;
-	}
-	driver_vec_to_buf(ev, buf, len);
-	file_output((ErlDrvData) desc, buf, len);
-	EF_FREE(buf);
-	goto done;
-    }
-
- done:
-    if (d != NULL) {
-#ifdef USE_VM_PROBES
-	/*
-	 * If d == NULL, then either:
-	 *    1). There was an error of some sort, or
-	 *    2). The command given to us is actually implemented
-	 *	  by file_output() instead.
-	 *
-	 * Case #1 is probably a TODO item, perhaps?
-	 * Case #2 we definitely don't want to activate a probe.
-	 */
-	d->sched_i1 = dt_priv->thread_num;
-	d->sched_i2 = dt_priv->tag;
-	d->sched_utag[0] = '\0';
-	if (dt_utag != NULL) {
-	    if (dt_utag[0] == '\0') {
-                dt_utag = NULL;
-            } else {
-		strncpy(d->sched_utag, dt_utag, sizeof(d->sched_utag) - 1);
-		d->sched_utag[sizeof(d->sched_utag) - 1] = '\0';
-	    }
-	}
-	DTRACE11(efile_drv_entry, dt_priv->thread_num, dt_priv->tag++,
-		 dt_utag, command, dt_s1, NULL, dt_i1, dt_i2, dt_i3, dt_i4,
-		 desc->port_str);
-#endif
-    }
-    cq_execute(desc);
-}
-
-#ifdef  USE_VM_PROBES
-dt_private *
-get_dt_private(int base)
-{
-    dt_private *dt_priv = (dt_private *) pthread_getspecific(dt_driver_key);
-
-    if (dt_priv == NULL) {
-	dt_priv = EF_SAFE_ALLOC(sizeof(dt_private));
-	erts_mtx_lock(&dt_driver_mutex);
-	dt_priv->thread_num = (base + dt_driver_idnum++);
-	erts_mtx_unlock(&dt_driver_mutex);
-	dt_priv->tag = 0;
-	pthread_setspecific(dt_driver_key, dt_priv);
-    }
-    return dt_priv;
-}
-#endif  /* USE_VM_PROBES */
diff --git a/erts/emulator/drivers/common/erl_efile.h b/erts/emulator/drivers/common/erl_efile.h
deleted file mode 100644
index b7f063b4f2..0000000000
--- a/erts/emulator/drivers/common/erl_efile.h
+++ /dev/null
@@ -1,176 +0,0 @@
-/*
- * %CopyrightBegin%
- *
- * Copyright Ericsson AB 1997-2016. 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%
- */
-/*
- * Defines the interfaces between the generic efile driver and its
- * operating-system dependent helpers.
- */
-
-#include "sys.h"
-#include "erl_driver.h"
-
-/*
- * Open modes for efile_openfile().
- */
-#define EFILE_MODE_READ 1
-#define EFILE_MODE_WRITE 2	/* Implies truncating file when used alone. */
-#define EFILE_MODE_READ_WRITE 	3
-#define EFILE_MODE_APPEND	4
-#define EFILE_COMPRESSED 	8
-#define EFILE_MODE_EXCL        16
-#define EFILE_NO_TRUNCATE      32 /* Special for reopening on VxWorks */
-#define EFILE_MODE_SYNC        64
-
-/*
- * Seek modes for efile_seek().
- */
-#define	EFILE_SEEK_SET	0
-#define	EFILE_SEEK_CUR	1
-#define	EFILE_SEEK_END	2
-
-/*
- * File types returned by efile_fileinfo().
- */
-#define FT_DEVICE 	1
-#define FT_DIRECTORY 	2
-#define FT_REGULAR	3
-#define FT_SYMLINK	4
-#define FT_OTHER	5
-
-/*
- * Access attributes returned by efile_fileinfo() (the bits can be ORed
- * together).
- */
-#define FA_NONE    	0
-#define FA_WRITE 	1
-#define FA_READ		2
-
-/* Some OS'es (i.e. Windows) has filenames in wide charaqcters. That requires special handling */
-/* Note that we do *not* honor alignment in the communication to the OS specific driver, */
-/* which is not a problem on x86, but might be on other platforms. The OS specific efile */
-/* implementation is expected to align if needed */
-#ifdef __WIN32__
-#define FILENAMES_16BIT 1
-#endif
-
-/* We use sendfilev if it exist on solaris */
-#if !defined(HAVE_SENDFILE) && defined(HAVE_SENDFILEV)
-#define HAVE_SENDFILE
-#endif
-
-/*
- * An handle to an open directory.  To be cast to the correct type
- * in the system-dependent directory functions.
- */
-
-typedef struct _Efile_Dir_Handle* EFILE_DIR_HANDLE;
-
-/*
- * Error information from the last call.
- */  
-typedef struct _Efile_error {
-    int posix_errno;		/* Posix error number, as in <errno.h>. */
-    int os_errno;		/* Os-dependent error number (not used). */
-} Efile_error;
-
-/*
- * Describes what is returned by file:file_info/1.
- */
-
-typedef struct _Efile_info {
-    Uint32 size_low;		/* Size of file, lower 32 bits.. */
-    Uint32 size_high;		/* Size of file, higher 32 bits. */
-    Uint32 type;		/* Type of file -- one of FT_*. */
-    Uint32 access;		/* Access to file -- one of FA_*. */
-    Uint32 mode;		/* Access permissions -- bit field. */
-    Uint32 links;		/* Number of links to file. */
-    Uint32 major_device;	/* Major device or file system. */
-    Uint32 minor_device;	/* Minor device (for devices). */
-    Uint32 inode;		/* Inode number. */
-    Uint32 uid;			/* User id of owner. */
-    Uint32 gid;			/* Group id of owner. */
-    Sint64 accessTime;		/* Last time the file was accessed. */
-    Sint64 modifyTime;		/* Last time the file was modified. */
-    Sint64 cTime;		/* Creation time (Windows) or last
-				 * inode change (Unix).
-				 */
-} Efile_info;
-
-
-#ifdef HAVE_SENDFILE
-/*
- * Describes the structure of headers/trailers for sendfile
- */
-struct t_sendfile_hdtl {
-    SysIOVec *headers;
-    int hdr_cnt;
-    SysIOVec *trailers;
-    int trl_cnt;
-};
-#endif /* HAVE_SENDFILE */
-
-/*
- * Functions.
- */
-int efile_init(void);
-int efile_mkdir(Efile_error* errInfo, char* name);
-int efile_rmdir(Efile_error* errInfo, char* name);
-int efile_delete_file(Efile_error* errInfo, char* name);
-int efile_rename(Efile_error* errInfo, char* src, char* dst);
-int efile_chdir(Efile_error* errInfo, char* name);
-int efile_getdcwd(Efile_error* errInfo, int drive,
-		  char* buffer, size_t size);
-int efile_readdir(Efile_error* errInfo, char* name, 
-		  EFILE_DIR_HANDLE* dir_handle,
-		  char* buffer, size_t *size);
-int efile_openfile(Efile_error* errInfo, char* name, int flags,
-		   int* pfd, Sint64* pSize);
-void efile_closefile(int fd);
-int efile_fdatasync(Efile_error* errInfo, int fd);
-int efile_fsync(Efile_error* errInfo, int fd);
-int efile_fileinfo(Efile_error* errInfo, Efile_info* pInfo,
-		   char *name, int info_for_link);
-int efile_write_info(Efile_error* errInfo, Efile_info* pInfo, char *name);
-int efile_write(Efile_error* errInfo, int flags, int fd, 
-		char* buf, size_t count);
-int efile_writev(Efile_error* errInfo, int flags, int fd, 
-		 SysIOVec* iov, int iovcnt);
-int efile_read(Efile_error* errInfo, int flags, int fd, 
-	       char* buf, size_t count, size_t* pBytesRead);
-int efile_seek(Efile_error* errInfo, int fd, 
-	       Sint64 offset, int origin, Sint64* new_location);
-int efile_truncate_file(Efile_error* errInfo, int *fd, int flags);
-int efile_pwrite(Efile_error* errInfo, int fd, 
-		 char* buf, size_t count, Sint64 offset);
-int efile_pread(Efile_error* errInfo, int fd, 
-		Sint64 offset, char* buf, size_t count, size_t* pBytesRead);
-int efile_readlink(Efile_error* errInfo, char *name, 
-		   char* buffer, size_t size);
-int efile_altname(Efile_error* errInfo, char *name, 
-		  char* buffer, size_t size);
-int efile_link(Efile_error* errInfo, char* old, char* new);
-int efile_symlink(Efile_error* errInfo, char* old, char* new);
-int efile_may_openfile(Efile_error* errInfo, char *name);
-int efile_fadvise(Efile_error* errInfo, int fd, Sint64 offset, Sint64 length,
-		  int advise);
-#ifdef HAVE_SENDFILE
-int efile_sendfile(Efile_error* errInfo, int in_fd, int out_fd,
-		      off_t *offset, Uint64 *nbytes, struct t_sendfile_hdtl *hdtl);
-#endif /* HAVE_SENDFILE */
-int efile_fallocate(Efile_error* errInfo, int fd, Sint64 offset, Sint64 length);
diff --git a/erts/emulator/drivers/common/gzio.c b/erts/emulator/drivers/common/gzio.c
index f60c781894..86c3b07cea 100644
--- a/erts/emulator/drivers/common/gzio.c
+++ b/erts/emulator/drivers/common/gzio.c
@@ -19,726 +19,16 @@
 #include <unistd.h>
 #endif
 #include <ctype.h>
+
 #include "erl_driver.h"
-#include "erl_efile.h"
 #include "sys.h"
 
-#ifdef __WIN32__
-#ifndef HAVE_CONFLICTING_FREAD_DECLARATION
-#define HAVE_CONFLICTING_FREAD_DECLARATION
-#endif
-#define FILENAMES_16BIT 1
-#endif
-
-#ifdef STDC
-#  define zstrerror(errnum) strerror(errnum)
-#else
-#  define zstrerror(errnum) ""
-#endif
-
 #include "gzio_zutil.h"
 #include "erl_zlib.h"
 #include "gzio.h"
 
-/********struct internal_state {int dummy;}; / * for buggy compilers */
-
-#define Z_BUFSIZE 4096
-
-#define ALLOC(size) driver_alloc(size)
-#define TRYFREE(p) {if (p) driver_free(p);}
-
 static int gz_magic[2] = {0x1f, 0x8b}; /* gzip magic header */
 
-/* gzip flag byte */
-#define ASCII_FLAG   0x01 /* bit 0 set: file probably ascii text */
-#define HEAD_CRC     0x02 /* bit 1 set: header CRC present */
-#define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
-#define ORIG_NAME    0x08 /* bit 3 set: original file name present */
-#define COMMENT      0x10 /* bit 4 set: file comment present */
-#define RESERVED     0xE0 /* bits 5..7: reserved */
-
-typedef struct gz_stream {
-    z_stream stream;
-    int      z_err;   /* error code for last stream operation */
-    int      z_eof;   /* set if end of input file */
-#ifdef UNIX
-    int      file;    /* .gz file descriptor */
-#else
-    FILE     *file;   /* .gz file */
-#endif
-    Byte     *inbuf;  /* input buffer */
-    Byte     *outbuf; /* output buffer */
-    uLong    crc;     /* crc32 of uncompressed data */
-    char     *msg;    /* error message */
-    char     *path;   /* path name for debugging only */
-    int      transparent; /* 1 if input file is not a .gz file */
-    char     mode;    /* 'w' or 'r' */
-    int      position; /* Position (for seek) */
-    int (*destroy)(struct gz_stream*); /* Function to destroy
-					    *  this structure. */
-} gz_stream;
-
-local ErtsGzFile gz_open      (const char *path, const char *mode);
-local int    get_byte     (gz_stream *s);
-local void   check_header (gz_stream *s);
-local int    destroy      (gz_stream *s);
-local uLong  getLong      (gz_stream *s);
-
-#ifdef UNIX
-/*
- * In Solaris 8 and earlier, fopen() and its friends cannot handle 
- * file descriptors larger than 255. Therefore, we use read()/write()
- * on all Unix systems.
- */
-# define ERTS_GZWRITE(File, Buf, Count) write((File), (Buf), (Count))
-# define ERTS_GZREAD(File, Buf, Count) read((File), (Buf), (Count))
-#else
-/*
- * On all other operating systems, using fopen(), fread()/fwrite(), since
- * there is not guaranteed to exist any read()/write() (not part of
- * ANSI/ISO-C).
- */
-# define ERTS_GZWRITE(File, Buf, Count) fwrite((Buf), 1, (Count), (File))
-# define ERTS_GZREAD(File, Buf, Count) fread((Buf), 1, (Count), (File))
-#endif
-
-/*
- * Ripped from efile_drv.c
- */
-
-#ifdef FILENAMES_16BIT
-#  define FILENAME_BYTELEN(Str) filename_len_16bit(Str)
-#  define FILENAME_COPY(To,From) filename_cpy_16bit((To),(From)) 
-#  define FILENAME_CHARSIZE 2
-
-   static int filename_len_16bit(const char *str) 
-   {
-       const char *p = str;
-       while(*p != '\0' || p[1] != '\0') {
-	   p += 2;
-       }
-       return (p - str);
-   }
-
-   static void filename_cpy_16bit(char *to, const char *from) 
-   {
-       while(*from != '\0' || from[1] != '\0') {
-	   *to++ = *from++;
-	   *to++ = *from++;
-       }
-       *to++ = *from++;
-       *to++ = *from++;
-   }
-
-#else
-#  define FILENAME_BYTELEN(Str) strlen(Str)
-#  define FILENAME_COPY(To,From) strcpy(To,From) 
-#  define FILENAME_CHARSIZE 1
-#endif
-
-/* ===========================================================================
-     Opens a gzip (.gz) file for reading or writing. The mode parameter
-   is as in fopen ("rb" or "wb"). The file is given either by file descriptor
-   or path name (if fd == -1).
-     gz_open return NULL if the file could not be opened or if there was
-   insufficient memory to allocate the (de)compression state; errno
-   can be checked to distinguish the two cases (if errno is zero, the
-   zlib error is Z_MEM_ERROR).
-*/
-local ErtsGzFile gz_open (path, mode)
-    const char *path;
-    const char *mode;
-{
-    int err;
-    int level = Z_DEFAULT_COMPRESSION; /* compression level */
-    char *p = (char*)mode;
-    gz_stream *s;
-    char fmode[80]; /* copy of mode, without the compression level */
-    char *m = fmode;
-
-    if (!path || !mode) return Z_NULL;
-
-    s = (gz_stream *)ALLOC(sizeof(gz_stream));
-    if (!s) return Z_NULL;
-
-    erl_zlib_alloc_init(&s->stream);
-    s->stream.next_in = s->inbuf = Z_NULL;
-    s->stream.next_out = s->outbuf = Z_NULL;
-    s->stream.avail_in = s->stream.avail_out = 0;
-#ifdef UNIX
-    s->file = -1;
-#else
-    s->file = NULL;
-#endif
-    s->z_err = Z_OK;
-    s->z_eof = 0;
-    s->crc = crc32(0L, Z_NULL, 0);
-    s->msg = NULL;
-    s->transparent = 0;
-    s->position = 0;
-    s->destroy = destroy;
-
-    s->path = (char*)ALLOC(FILENAME_BYTELEN(path)+FILENAME_CHARSIZE);
-    if (s->path == NULL) {
-        return s->destroy(s), (ErtsGzFile)Z_NULL;
-    }
-    FILENAME_COPY(s->path, path); /* do this early for debugging */
-
-    s->mode = '\0';
-    do {
-        if (*p == 'r')
-	    s->mode = 'r';
-	if (*p == 'w' || *p == 'a')
-	    s->mode = 'w';
-	if (isdigit((int)*p)) {
-	    level = *p - '0';
-	} else {
-	    *m++ = *p;		/* Copy the mode */
-	}
-    } while (*p++ && m < fmode + sizeof(fmode) - 1);
-    *m = '\0';
-    if (s->mode == '\0')
-	return s->destroy(s), (ErtsGzFile)Z_NULL;
-    
-    if (s->mode == 'w') {
-        err = deflateInit2(&(s->stream), level,
-                           Z_DEFLATED, MAX_WBITS+16, DEF_MEM_LEVEL, 0);
-        /* windowBits is passed < 0 to suppress zlib header */
-
-        s->stream.next_out = s->outbuf = (Byte*)ALLOC(Z_BUFSIZE);
-
-        if (err != Z_OK || s->outbuf == Z_NULL) {
-            return s->destroy(s), (ErtsGzFile)Z_NULL;
-        }
-    } else {
-	/*
-	 * It is tempting to use the built-in support in zlib
-	 * for handling GZIP headers, but unfortunately it
-	 * cannot handle multiple GZIP headers (which occur when
-	 * several GZIP files have been concatenated).
-	 */
-
-	err = inflateInit2(&(s->stream), -MAX_WBITS);
-        s->stream.next_in  = s->inbuf = (Byte*)ALLOC(Z_BUFSIZE);
-
-        if (err != Z_OK || s->inbuf == Z_NULL) {
-            return s->destroy(s), (ErtsGzFile)Z_NULL;
-        }
-    }
-    s->stream.avail_out = Z_BUFSIZE;
-
-    errno = 0;
-#if defined(FILENAMES_16BIT)
-    {
-	FILE* efile_wfopen(const WCHAR* name, const WCHAR* mode);
-	WCHAR wfmode[80];
-	int i = 0;
-	int j;
-	for(j = 0; fmode[j] != '\0'; ++j) {
-	    wfmode[i++] = (WCHAR) fmode[j];
-	}
-	wfmode[i++] = L'\0';
-	s->file = efile_wfopen((WCHAR *)path, wfmode);
-	if (s->file == NULL) {
-	    return s->destroy(s), (ErtsGzFile)Z_NULL;
-	}
-    }
-#elif defined(UNIX)
-    if (s->mode == 'r') {
-	s->file = open(path, O_RDONLY);
-    } else {
-	s->file = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0666);
-    }
-    if (s->file == -1) {
-        return s->destroy(s), (ErtsGzFile)Z_NULL;
-    }
-#else
-    s->file = fopen(path, fmode);
-    if (s->file == NULL) {
-        return s->destroy(s), (ErtsGzFile)Z_NULL;
-    }
-#endif
-    if (s->mode == 'r') {
-	check_header(s); /* skip the .gz header */
-    }
-    return (ErtsGzFile)s;
-}
-
-/* ===========================================================================
-   Rewind a gzfile back to the beginning.
-*/
-
-local int gz_rewind (gz_stream *s)
-{
-    TRYFREE(s->msg);
-
-#ifdef UNIX
-    lseek(s->file, 0L, SEEK_SET);
-#else
-    fseek(s->file, 0L, SEEK_SET);
-#endif
-    inflateReset(&(s->stream));
-    s->stream.next_in = Z_NULL;
-    s->stream.next_out = Z_NULL;
-    s->stream.avail_in = s->stream.avail_out = 0;
-    s->z_err = Z_OK;
-    s->z_eof = 0;
-    s->crc = crc32(0L, Z_NULL, 0);
-    s->msg = NULL;
-    s->position = 0;
-    s->stream.next_in = s->inbuf;
-
-    s->stream.avail_out = Z_BUFSIZE;
-
-    check_header(s);		/* skip the .gz header */
-    return 1;
-}
-
-/* ===========================================================================
-     Opens a gzip (.gz) file for reading or writing.
-*/
-ErtsGzFile erts_gzopen (path, mode)
-    const char *path;
-    const char *mode;
-{
-    return gz_open (path, mode);
-}
-
-
-/* ===========================================================================
-     Read a byte from a gz_stream; update next_in and avail_in. Return EOF
-   for end of file.
-   IN assertion: the stream s has been successfully opened for reading.
-*/
-local int get_byte(s)
-    gz_stream *s;
-{
-    if (s->z_eof) return EOF;
-    if (s->stream.avail_in == 0) {
-#ifdef UNIX
-	ssize_t res;
-	errno = 0;
-	res = ERTS_GZREAD(s->file, s->inbuf, Z_BUFSIZE);
-	if (res == 0) {
-	    s->stream.avail_in = 0;
-	    s->z_eof = 1;
-	    return EOF;
-	} else if (res < 0) {
-	    s->stream.avail_in = 0;
-	    s->z_eof = 1;
-	    s->z_err = Z_ERRNO;
-	    return EOF;
-	} else {
-	    s->stream.avail_in = (uInt) res;
-	}
-#else
-	errno = 0;
-	s->stream.avail_in = ERTS_GZREAD(s->file, s->inbuf, Z_BUFSIZE);
-	if (s->stream.avail_in == 0) {
-	    s->z_eof = 1;
-	    if (s->file && ferror(s->file))
-		s->z_err = Z_ERRNO;
-	    return EOF;
-	}
-#endif
-	s->stream.next_in = s->inbuf;
-    }
-    s->stream.avail_in--;
-    return *(s->stream.next_in)++;
-}
-
-/* ===========================================================================
-      Check the gzip header of a gz_stream opened for reading. Set the stream
-    mode to transparent if the gzip magic header is not present; set s->err
-    to Z_DATA_ERROR if the magic header is present but the rest of the header
-    is incorrect.
-    IN assertion: the stream s has already been created sucessfully;
-       s->stream.avail_in is zero for the first time, but may be non-zero
-       for concatenated .gz files.
-*/
-local void check_header(s)
-    gz_stream *s;
-{
-    int method; /* method byte */
-    int flags;  /* flags byte */
-    uInt len;
-    int c;
-
-    /* Check the gzip magic header */
-    for (len = 0; len < 2; len++) {
-	c = get_byte(s);
-	if (c != gz_magic[len]) {
-	    if (len != 0) s->stream.avail_in++, s->stream.next_in--;
-	    if (c != EOF) {
-		s->stream.avail_in++, s->stream.next_in--;
-		s->transparent = 1;
-	    }
-	    s->z_err = s->stream.avail_in != 0 ? Z_OK : Z_STREAM_END;
-	    return;
-	}
-    }
-    method = get_byte(s);
-    flags = get_byte(s);
-    if (method != Z_DEFLATED || (flags & RESERVED) != 0) {
-	s->z_err = Z_DATA_ERROR;
-	return;
-    }
-
-    /* Discard time, xflags and OS code: */
-    for (len = 0; len < 6; len++) (void)get_byte(s);
-
-    if ((flags & EXTRA_FIELD) != 0) { /* skip the extra field */
-	len  =  (uInt)get_byte(s);
-	len += ((uInt)get_byte(s))<<8;
-	/* len is garbage if EOF but the loop below will quit anyway */
-	while (len-- != 0 && get_byte(s) != EOF) ;
-    }
-    if ((flags & ORIG_NAME) != 0) { /* skip the original file name */
-	while ((c = get_byte(s)) != 0 && c != EOF) ;
-    }
-    if ((flags & COMMENT) != 0) {   /* skip the .gz file comment */
-	while ((c = get_byte(s)) != 0 && c != EOF) ;
-    }
-    if ((flags & HEAD_CRC) != 0) {  /* skip the header crc */
-	for (len = 0; len < 2; len++) (void)get_byte(s);
-    }
-    s->z_err = s->z_eof ? Z_DATA_ERROR : Z_OK;
-}
-
- /* ===========================================================================
- * Cleanup then free the given gz_stream. Return a zlib error code.
-   Try freeing in the reverse order of allocations.
- */
-local int destroy (s)
-    gz_stream *s;
-{
-    int err = Z_OK;
-
-    if (!s) return Z_STREAM_ERROR;
-
-    TRYFREE(s->msg);
-
-    if (s->stream.state != NULL) {
-       if (s->mode == 'w') {
-           err = deflateEnd(&(s->stream));
-       } else if (s->mode == 'r') {
-           err = inflateEnd(&(s->stream));
-       }
-    }
-#ifdef UNIX
-    if (s->file != -1 && close(s->file)) {
-        err = Z_ERRNO;
-    }
-#else
-    if (s->file != NULL && fclose(s->file)) {
-        err = Z_ERRNO;
-    }
-#endif
-    if (s->z_err < 0) err = s->z_err;
-
-    TRYFREE(s->inbuf);
-    TRYFREE(s->outbuf);
-    TRYFREE(s->path);
-    TRYFREE(s);
-    return err;
-}
-
-/* ===========================================================================
-     Reads the given number of uncompressed bytes from the compressed file.
-   gzread returns the number of bytes actually read (0 for end of file).
-*/
-int
-erts_gzread(ErtsGzFile file, voidp buf, unsigned len)
-{
-    gz_stream *s = (gz_stream*)file;
-    Bytef *start = buf; /* starting point for crc computation */
-    Byte  *next_out; /* == stream.next_out but not forced far (for MSDOS) */
-
-    if (s == NULL || s->mode != 'r') return Z_STREAM_ERROR;
-
-    if (s->z_err == Z_DATA_ERROR || s->z_err == Z_ERRNO) return -1;
-    if (s->z_err == Z_STREAM_END) return 0;  /* EOF */
-
-    s->stream.next_out = next_out = buf;
-    s->stream.avail_out = len;
-
-    while (s->stream.avail_out != 0) {
-
-	if (s->transparent) {
-	    /* Copy first the lookahead bytes: */
-	    uInt n = s->stream.avail_in;
-	    if (n > s->stream.avail_out) n = s->stream.avail_out;
-	    if (n > 0) {
-		zmemcpy(s->stream.next_out, s->stream.next_in, n);
-		next_out += n;
-		s->stream.next_out = next_out;
-		s->stream.next_in   += n;
-		s->stream.avail_out -= n;
-		s->stream.avail_in  -= n;
-	    }
-	    if (s->stream.avail_out > 0) {
-		s->stream.avail_out -= ERTS_GZREAD(s->file, next_out,
-						   s->stream.avail_out);
-	    }
-	    len -= s->stream.avail_out;
-	    s->stream.total_in  += (uLong)len;
-	    s->stream.total_out += (uLong)len;
-            if (len == 0) s->z_eof = 1;
-	    s->position += (int)len;
-	    return (int)len;
-	}
-        if (s->stream.avail_in == 0 && !s->z_eof) {
-#ifdef UNIX
-	    ssize_t res;
-	    errno = 0;
-	    res = ERTS_GZREAD(s->file, s->inbuf, Z_BUFSIZE);
-	    if (res == 0) {
-		s->stream.avail_in = 0;
-		s->z_eof = 1;
-		return EOF;
-	    } else if (res < 0) {
-		s->stream.avail_in = 0;
-		s->z_eof = 1;
-		s->z_err = Z_ERRNO;
-		return EOF;
-	    } else {
-		s->stream.avail_in = (uInt) res;
-	    }
-#else
-	    errno = 0;
-            s->stream.avail_in = ERTS_GZREAD(s->file, s->inbuf, Z_BUFSIZE);
-            if (s->stream.avail_in == 0) {
-                s->z_eof = 1;
-		if (s->file && ferror(s->file)) {
-		    s->z_err = Z_ERRNO;
-		    break;
-		}
-            }
-#endif
-            s->stream.next_in = s->inbuf;
-        }
-        s->z_err = inflate(&(s->stream), Z_NO_FLUSH);
-
-	if (s->z_err == Z_STREAM_END) {
-	    /* Check CRC and original size */
-	    s->crc = crc32(s->crc, start, (uInt)(s->stream.next_out - start));
-	    start = s->stream.next_out;
-
-	    if (getLong(s) != s->crc) {
-		s->z_err = Z_DATA_ERROR;
-	    } else {
-	        (void)getLong(s);
-                /* The uncompressed length returned by above getlong() may
-                 * be different from s->stream.total_out) in case of
-		 * concatenated .gz files. Check for such files:
-		 */
-		check_header(s);
-		if (s->z_err == Z_OK) {
-		    uLong total_in = s->stream.total_in;
-		    uLong total_out = s->stream.total_out;
-
-		    inflateReset(&(s->stream));
-		    s->stream.total_in = total_in;
-		    s->stream.total_out = total_out;
-		    s->crc = crc32(0L, Z_NULL, 0);
-		}
-	    }
-	}
-	if (s->z_err != Z_OK || s->z_eof) break;
-    }
-    s->crc = crc32(s->crc, start, (uInt)(s->stream.next_out - start));
-
-    s->position += (int)(len - s->stream.avail_out);
-
-    return (int)(len - s->stream.avail_out);
-}
-
-/* ===========================================================================
-     Writes the given number of uncompressed bytes into the compressed file.
-   gzwrite returns the number of bytes actually written (0 in case of error).
-*/
-int
-erts_gzwrite(ErtsGzFile file, voidp buf, unsigned len)
-{
-    gz_stream *s = (gz_stream*)file;
-
-    if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR;
-
-    s->stream.next_in = buf;
-    s->stream.avail_in = len;
-
-    while (s->stream.avail_in != 0) {
-
-        if (s->stream.avail_out == 0) {
-
-            s->stream.next_out = s->outbuf;
-            if (ERTS_GZWRITE(s->file, s->outbuf, Z_BUFSIZE) != Z_BUFSIZE) {
-                s->z_err = Z_ERRNO;
-                break;
-            }
-            s->stream.avail_out = Z_BUFSIZE;
-        }
-        s->z_err = deflate(&(s->stream), Z_NO_FLUSH);
-        if (s->z_err != Z_OK) break;
-    }
-    s->position += (int)(len - s->stream.avail_in);
-    return (int)(len - s->stream.avail_in);
-}
-
-/*
- * For use by Erlang file driver.
- *
- * XXX Limitations:
- *  - SEEK_END is not allowed (length of file is not known).
- *  - When writing, only forward seek is supported.
- */
-
-int
-erts_gzseek(ErtsGzFile file, int offset, int whence)
-{
-    int pos;
-    gz_stream* s = (gz_stream *) file;
-
-    switch (whence) {
-    case EFILE_SEEK_SET: whence = SEEK_SET; break;
-    case EFILE_SEEK_CUR: whence = SEEK_CUR; break;
-    case EFILE_SEEK_END: whence = SEEK_END; break;
-    default:
-	errno = EINVAL;
-	return -1;
-    }
-
-    if (s == NULL) {
-	errno = EINVAL;
-	return -1;
-    }
-    if (s->z_err == Z_DATA_ERROR || s->z_err == Z_ERRNO) {
-	errno = EIO;
-	return -1;
-    }
-
-    switch (whence) {
-    case SEEK_SET: pos = offset; break;
-    case SEEK_CUR: pos = s->position+offset; break;
-    case SEEK_END: 
-    default:
-      errno = EINVAL; return -1;
-    }
-
-    if (pos == s->position) {
-	return pos;
-    }
-
-    if (pos < s->position) {
-	if (s->mode == 'w') {
-	    errno = EINVAL;
-	    return -1;
-	}
-	gz_rewind(s);
-    }
-
-    while (s->position < pos) {
-	char buf[512];
-	int n;
-	int save_pos = s->position;
-
-	n = pos - s->position;
-	if (n > sizeof(buf))
-	    n = sizeof(buf);
-
-	if (s->mode == 'r') {
-	    erts_gzread(file, buf, n);
-	} else {
-	    memset(buf, '\0', n);
-	    erts_gzwrite(file, buf, n);
-	}
-	if (save_pos == s->position) break;
-    }
-
-    return s->position;
-}
-
-/* ===========================================================================
-     Flushes all pending output into the compressed file. The parameter
-   flush is as in the deflate() function.
-     gzflush should be called only when strictly necessary because it can
-   degrade compression.
-*/
-int
-erts_gzflush(ErtsGzFile file, int flush)
-{
-    uInt len;
-    int done = 0;
-    gz_stream *s = (gz_stream*)file;
-
-    if (s == NULL || s->mode != 'w') return Z_STREAM_ERROR;
-
-    s->stream.avail_in = 0; /* should be zero already anyway */
-
-    for (;;) {
-        len = Z_BUFSIZE - s->stream.avail_out;
-
-        if (len != 0) {
-            if ((uInt)ERTS_GZWRITE(s->file, s->outbuf, len) != len) {
-                s->z_err = Z_ERRNO;
-                return Z_ERRNO;
-            }
-            s->stream.next_out = s->outbuf;
-            s->stream.avail_out = Z_BUFSIZE;
-        }
-        if (done) break;
-        s->z_err = deflate(&(s->stream), flush);
-
-        /* deflate has finished flushing only when it hasn't used up
-         * all the available space in the output buffer: 
-         */
-        done = (s->stream.avail_out != 0 || s->z_err == Z_STREAM_END);
- 
-        if (s->z_err != Z_OK && s->z_err != Z_STREAM_END) break;
-    }
-#ifndef UNIX
-    fflush(s->file);
-#endif
-    return  s->z_err == Z_STREAM_END ? Z_OK : s->z_err;
-}
-
-/* ===========================================================================
-   Reads a long in LSB order from the given gz_stream. Sets 
-*/
-local uLong getLong (s)
-    gz_stream *s;
-{
-    uLong x = (uLong)get_byte(s);
-    int c;
-
-    x += ((uLong)get_byte(s))<<8;
-    x += ((uLong)get_byte(s))<<16;
-    c = get_byte(s);
-    if (c == EOF) s->z_err = Z_DATA_ERROR;
-    x += ((uLong)c)<<24;
-    return x;
-}
-
-/* ===========================================================================
-     Flushes all pending output if necessary, closes the compressed file
-   and deallocates all the (de)compression state.
-*/
-int
-erts_gzclose(ErtsGzFile file)
-{
-    int err;
-    gz_stream *s = (gz_stream*)file;
-
-    if (s == NULL) return Z_STREAM_ERROR;
-
-    if (s->mode == 'w') {
-        err = erts_gzflush (file, Z_FINISH);
-        if (err != Z_OK) return s->destroy(s);
-    }
-    return s->destroy(s);
-}
-
-
 /* ===========================================================================
    Uncompresses the buffer given and returns a pointer to a binary.
    If the buffer was not compressed with gzip, the buffer contents
diff --git a/erts/emulator/drivers/common/gzio.h b/erts/emulator/drivers/common/gzio.h
index ee0ebe7bd8..e331b5208b 100644
--- a/erts/emulator/drivers/common/gzio.h
+++ b/erts/emulator/drivers/common/gzio.h
@@ -20,13 +20,5 @@
 
 #include "zlib.h"
 
-typedef struct erts_gzFile* ErtsGzFile;
-
-ErtsGzFile erts_gzopen (const char *path, const char *mode);
-int erts_gzread(ErtsGzFile file, voidp buf, unsigned len);
-int erts_gzwrite(ErtsGzFile file, voidp buf, unsigned len);
-int erts_gzseek(ErtsGzFile, int, int);
-int erts_gzflush(ErtsGzFile file, int flush);
-int erts_gzclose(ErtsGzFile file);
 ErlDrvBinary* erts_gzinflate_buffer(char*, uLong);
 ErlDrvBinary* erts_gzdeflate_buffer(char*, uLong);
diff --git a/erts/emulator/drivers/common/inet_drv.c b/erts/emulator/drivers/common/inet_drv.c
index 95d61fcc5d..4294fb4f46 100644
--- a/erts/emulator/drivers/common/inet_drv.c
+++ b/erts/emulator/drivers/common/inet_drv.c
@@ -63,6 +63,20 @@
 #include <sys/un.h>
 #endif
 
+#ifdef HAVE_SENDFILE
+#if defined(__linux__) || (defined(__sun) && defined(__SVR4))
+    #include <sys/sendfile.h>
+#elif defined(__FreeBSD__) || defined(__DragonFly__)
+    /* Need to define __BSD_VISIBLE in order to expose prototype of sendfile */
+    #define __BSD_VISIBLE 1
+    #include <sys/socket.h>
+#endif
+#endif
+
+#if defined(__APPLE__) && defined(__MACH__) && !defined(__DARWIN__)
+    #define __DARWIN__ 1
+#endif
+
 /* All platforms fail on malloc errors. */
 #define FATAL_MALLOC
 
@@ -701,6 +715,7 @@ static size_t my_strnlen(const char *s, size_t maxlen)
 #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 /* Common for UDP and SCTP         */
 /* #define SCTP_REQ_LISTEN       61 MERGED Different from TCP; not for UDP */
@@ -723,6 +738,7 @@ static size_t my_strnlen(const char *s, size_t maxlen)
 #define TCP_ADDF_DELAYED_ECONNRESET 128 /* An ECONNRESET error occurred on send or shutdown */
 #define TCP_ADDF_SHUTDOWN_WR_DONE 256 /* A shutdown(sock, SHUT_WR) or SHUT_RDWR was made */
 #define TCP_ADDF_LINGER_ZERO 	  512 /* Discard driver queue on port close */
+#define TCP_ADDF_SENDFILE         1024 /* Send from an fd instead of the driver queue */
 
 /* *_REQ_* replies */
 #define INET_REP_ERROR       0
@@ -1235,6 +1251,21 @@ typedef struct {
     inet_async_multi_op *multi_first;/* NULL == no multi-accept-queue, op is in ordinary queue */
     inet_async_multi_op *multi_last;
     MultiTimerData *mtd;        /* Timer structures for multiple accept */
+#ifdef HAVE_SENDFILE
+    struct {
+        ErlDrvSizeT ioq_skip;   /* The number of bytes in the queue at the time
+                                 * sendfile was issued, which must be sent
+                                 * before issuing the sendfile call itself. */
+        int dup_file_fd;        /* The file handle to send from; this is
+                                 * duplicated when sendfile is issued to
+                                 * reduce (but not eliminate) the impact of a
+                                 * nasty race, so we have to remember to close
+                                 * it. */
+        Uint64 bytes_sent;
+        Uint64 offset;
+        Uint64 length;
+    } sendfile;
+#endif
 } tcp_descriptor;
 
 /* send function */
@@ -1245,6 +1276,8 @@ static int tcp_deliver(tcp_descriptor* desc, int len);
 
 static int tcp_shutdown_error(tcp_descriptor* desc, int err);
 
+static int tcp_inet_sendfile(tcp_descriptor* desc);
+
 static int tcp_inet_output(tcp_descriptor* desc, HANDLE event);
 static int tcp_inet_input(tcp_descriptor* desc, HANDLE event);
 
@@ -1329,6 +1362,9 @@ static ErlDrvTermData am_ipv6_v6only;
 static ErlDrvTermData am_netns;
 static ErlDrvTermData am_bind_to_device;
 #endif
+#ifdef HAVE_SENDFILE
+static ErlDrvTermData am_sendfile;
+#endif
 
 static char str_eafnosupport[] = "eafnosupport";
 static char str_einval[] = "einval";
@@ -3875,6 +3911,10 @@ static int inet_init()
     INIT_ATOM(https);
     INIT_ATOM(scheme);
 
+#ifdef HAVE_SENDFILE
+    INIT_ATOM(sendfile);
+#endif
+
     /* add TCP, UDP and SCTP drivers */
     add_driver_entry(&tcp_inet_driver_entry);
 #ifdef HAVE_UDP
@@ -9270,6 +9310,13 @@ static void tcp_inet_stop(ErlDrvData e)
  * will be freed through tcp_inet_stop later on. */
 static void tcp_desc_close(tcp_descriptor* desc)
 {
+#ifdef HAVE_SENDFILE
+    if(desc->tcp_add_flags & TCP_ADDF_SENDFILE) {
+        desc->tcp_add_flags &= ~TCP_ADDF_SENDFILE;
+        close(desc->sendfile.dup_file_fd);
+    }
+#endif
+
     tcp_clear_input(desc);
     tcp_clear_output(desc);
 
@@ -9608,6 +9655,60 @@ static ErlDrvSSizeT tcp_inet_ctl(ErlDrvData e, unsigned int cmd,
 	    return ctl_reply(INET_REP_OK, NULL, 0, rbuf, rsize);
 	}
     }
+
+    case TCP_REQ_SENDFILE: {
+#ifdef HAVE_SENDFILE
+        const ErlDrvSizeT required_len =
+            sizeof(desc->sendfile.dup_file_fd) +
+            sizeof(Uint64) * 2;
+
+        int raw_file_fd;
+
+        DEBUGF(("tcp_inet_ctl(%ld): SENDFILE\r\n", (long)desc->inet.port));
+
+        if (len != required_len) {
+            return ctl_error(EINVAL, rbuf, rsize);
+        } else if (!IS_CONNECTED(INETP(desc))) {
+            return ctl_error(ENOTCONN, rbuf, rsize);
+        }
+
+        sys_memcpy(&raw_file_fd, buf, sizeof(raw_file_fd));
+        buf += sizeof(raw_file_fd);
+
+        desc->sendfile.dup_file_fd = dup(raw_file_fd);
+
+        if(desc->sendfile.dup_file_fd == -1) {
+            return ctl_error(errno, rbuf, rsize);
+        }
+
+        desc->sendfile.offset = get_int64(buf);
+        buf += sizeof(Uint64);
+
+        desc->sendfile.length = get_int64(buf);
+        buf += sizeof(Uint64);
+
+        ASSERT(desc->sendfile.offset >= 0);
+        ASSERT(desc->sendfile.length >= 0);
+
+        desc->sendfile.ioq_skip = driver_sizeq(desc->inet.port);
+        desc->sendfile.bytes_sent = 0;
+
+        desc->inet.caller = driver_caller(desc->inet.port);
+        desc->tcp_add_flags |= TCP_ADDF_SENDFILE;
+
+        /* See if we can finish sending without selecting & rescheduling. */
+        tcp_inet_sendfile(desc);
+
+        if(desc->sendfile.length > 0) {
+            sock_select(INETP(desc), FD_WRITE, 1);
+        }
+
+        return ctl_reply(INET_REP_OK, NULL, 0, rbuf, rsize);
+#else
+        return ctl_error(ENOTSUP, rbuf, rsize);
+#endif
+    }
+
     default:
 	DEBUGF(("tcp_inet_ctl(%ld): %u\r\n", (long)desc->inet.port, cmd)); 
 	return inet_ctl(INETP(desc), cmd, buf, len, rbuf, rsize);
@@ -9747,12 +9848,27 @@ static void tcp_inet_commandv(ErlDrvData e, ErlIOVec* ev)
 static void tcp_inet_flush(ErlDrvData e)
 {
     tcp_descriptor* desc = (tcp_descriptor*)e;
-    if (!(desc->inet.event_mask & FD_WRITE)) {
-	/* Discard send queue to avoid hanging port (OTP-7615) */
-	tcp_clear_output(desc);
+    int discard_output;
+
+    /* Discard send queue to avoid hanging port (OTP-7615) */
+    discard_output = !(desc->inet.event_mask & FD_WRITE);
+
+    discard_output |= desc->tcp_add_flags & TCP_ADDF_LINGER_ZERO;
+
+#ifdef HAVE_SENDFILE
+    /* The old file driver aborted when it was stopped during sendfile, so
+     * we'll clear the flag and discard all output. */
+    if(desc->tcp_add_flags & TCP_ADDF_SENDFILE) {
+        desc->tcp_add_flags &= ~TCP_ADDF_SENDFILE;
+        close(desc->sendfile.dup_file_fd);
+
+        discard_output = 1;
+    }
+#endif
+
+    if (discard_output) {
+        tcp_clear_output(desc);
     }
-    if (desc->tcp_add_flags & TCP_ADDF_LINGER_ZERO)
-	tcp_clear_output(desc);
 }
 
 static void tcp_inet_process_exit(ErlDrvData e, ErlDrvMonitor *monitorp) 
@@ -10647,7 +10763,9 @@ static int tcp_sendv(tcp_descriptor* desc, ErlIOVec* ev)
 	ev->size += h_len;
     }
 
-    if ((sz = driver_sizeq(ix)) > 0) {
+    sz = driver_sizeq(ix);
+
+    if ((desc->tcp_add_flags & TCP_ADDF_SENDFILE) || sz > 0) {
 	driver_enqv(ix, ev, 0);
 	if (sz+ev->size >= desc->high) {
 	    DEBUGF(("tcp_sendv(%ld): s=%d, sender forced busy\r\n",
@@ -10741,8 +10859,9 @@ static int tcp_send(tcp_descriptor* desc, char* ptr, ErlDrvSizeT len)
 
     inet_output_count(INETP(desc), len+h_len);
 
+    sz = driver_sizeq(ix);
 
-    if ((sz = driver_sizeq(ix)) > 0) {
+    if ((desc->tcp_add_flags & TCP_ADDF_SENDFILE) || sz > 0) {
 	if (h_len > 0)
 	    driver_enq(ix, buf, h_len);
 	driver_enq(ix, ptr, len);
@@ -10832,6 +10951,246 @@ static void tcp_inet_drv_input(ErlDrvData data, ErlDrvEvent event)
     (void)tcp_inet_input((tcp_descriptor*)data, (HANDLE)event);
 }
 
+#ifdef HAVE_SENDFILE
+static int tcp_sendfile_completed(tcp_descriptor* desc) {
+    ErlDrvTermData spec[LOAD_PORT_CNT + LOAD_TUPLE_CNT * 2 +
+        LOAD_ATOM_CNT * 2 + LOAD_UINT_CNT * 2];
+    Uint32 sent_low, sent_high;
+    int i;
+
+    desc->tcp_add_flags &= ~TCP_ADDF_SENDFILE;
+    close(desc->sendfile.dup_file_fd);
+
+    /* While we flushed the output queue prior to sending the file, we've
+     * deferred clearing busy status until now as there's no point in doing so
+     * while we still have a file to send.
+     *
+     * The watermark is checked since more data may have been added while we
+     * were sending the file. */
+
+    if (driver_sizeq(desc->inet.port) <= desc->low) {
+        if (IS_BUSY(INETP(desc))) {
+            desc->inet.caller = desc->inet.busy_caller;
+            desc->inet.state &= ~INET_F_BUSY;
+
+            set_busy_port(desc->inet.port, 0);
+
+            /* if we have a timer then cancel and send ok to client */
+            if (desc->busy_on_send) {
+                driver_cancel_timer(desc->inet.port);
+                desc->busy_on_send = 0;
+            }
+
+            inet_reply_ok(INETP(desc));
+        }
+    }
+
+    if (driver_sizeq(desc->inet.port) == 0) {
+        sock_select(INETP(desc), FD_WRITE, 0);
+        send_empty_out_q_msgs(INETP(desc));
+
+        if (desc->tcp_add_flags & TCP_ADDF_PENDING_SHUTDOWN) {
+            tcp_shutdown_async(desc);
+        }
+    }
+
+    sent_low = ((Uint64)desc->sendfile.bytes_sent >> 0) & 0xFFFFFFFF;
+    sent_high = ((Uint64)desc->sendfile.bytes_sent >> 32) & 0xFFFFFFFF;
+
+    i = LOAD_ATOM(spec, 0, am_sendfile);
+    i = LOAD_PORT(spec, i, desc->inet.dport);
+    i = LOAD_ATOM(spec, i, am_ok);
+    i = LOAD_UINT(spec, i, sent_low);
+    i = LOAD_UINT(spec, i, sent_high);
+    i = LOAD_TUPLE(spec, i, 3);
+    i = LOAD_TUPLE(spec, i, 3);
+
+    ASSERT(i == sizeof(spec)/sizeof(*spec));
+
+    return erl_drv_output_term(desc->inet.dport, spec, i);
+}
+
+static int tcp_sendfile_aborted(tcp_descriptor* desc, int socket_error) {
+    ErlDrvTermData spec[LOAD_PORT_CNT + LOAD_TUPLE_CNT * 2 + LOAD_ATOM_CNT * 3];
+    int i;
+
+    /* We don't clean up sendfile state here, as that's done in tcp_desc_close
+     * following normal error handling. All we do here is report the failure. */
+
+    i = LOAD_ATOM(spec, 0, am_sendfile);
+    i = LOAD_PORT(spec, i, desc->inet.dport);
+    i = LOAD_ATOM(spec, i, am_error);
+
+    switch (socket_error) {
+    case ECONNRESET:
+    case ENOTCONN:
+    case EPIPE:
+        i = LOAD_ATOM(spec, i, am_closed);
+        break;
+    default:
+        i = LOAD_ATOM(spec, i, error_atom(socket_error));
+    }
+
+    i = LOAD_TUPLE(spec, i, 2);
+    i = LOAD_TUPLE(spec, i, 3);
+
+    ASSERT(i == sizeof(spec)/sizeof(*spec));
+
+    return erl_drv_output_term(desc->inet.dport, spec, i);
+}
+
+static int tcp_inet_sendfile(tcp_descriptor* desc) {
+    ErlDrvPort ix = desc->inet.port;
+    int result = 0;
+    ssize_t n;
+
+    DEBUGF(("tcp_inet_sendfile(%ld) {s=%d\r\n", (long)ix, desc->inet.s));
+
+    /* If there was any data in the queue by the time sendfile was issued,
+     * we'll need to skip it first. Note that we don't clear busy status until
+     * we're finished sending the file. */
+    while (desc->sendfile.ioq_skip > 0) {
+        ssize_t bytes_to_send;
+        SysIOVec* iov;
+        int vsize;
+
+        ASSERT(driver_sizeq(ix) >= desc->sendfile.ioq_skip);
+
+        if ((iov = driver_peekq(ix, &vsize)) == NULL) {
+            ERTS_INTERNAL_ERROR("ioq empty when sendfile.ioq_skip > 0");
+        }
+
+        bytes_to_send = MIN(desc->sendfile.ioq_skip, iov[0].iov_len);
+        n = sock_send(desc->inet.s, iov[0].iov_base, bytes_to_send, 0);
+
+        if (!IS_SOCKET_ERROR(n)) {
+            desc->sendfile.ioq_skip -= n;
+            driver_deq(ix, n);
+        } else if (sock_errno() == ERRNO_BLOCK) {
+#ifdef __WIN32__
+            desc->inet.send_would_block = 1;
+#endif
+            goto done;
+        } else if (sock_errno() != EINTR) {
+            goto socket_error;
+        }
+    }
+
+    while (desc->sendfile.length > 0) {
+        /* For some reason the maximum ssize_t cannot be used as the max size.
+         * 1GB seems to work on all platforms */
+        const Sint64 SENDFILE_CHUNK_SIZE = ((1UL << 30) - 1);
+
+        ssize_t bytes_to_send = MIN(SENDFILE_CHUNK_SIZE, desc->sendfile.length);
+        off_t offset = desc->sendfile.offset;
+
+#if defined(__linux__)
+        n = sendfile(desc->inet.s, desc->sendfile.dup_file_fd, &offset,
+            bytes_to_send);
+#elif defined(__FreeBSD__) || defined(__DragonFly__) || defined(__DARWIN__)
+        {
+            off_t bytes_sent;
+            int error;
+
+    #if defined(__DARWIN__)
+            bytes_sent = bytes_to_send;
+
+            error = sendfile(desc->sendfile.dup_file_fd, desc->inet.s, offset,
+                &bytes_sent, NULL, 0);
+            n = bytes_sent;
+    #else
+            error = sendfile(desc->sendfile.dup_file_fd, desc->inet.s, offset,
+                bytes_to_send, NULL, &bytes_sent, 0);
+            n = bytes_sent;
+    #endif
+
+            if(error < 0) {
+                /* EAGAIN/EINTR report partial success by setting bytes_sent,
+                 * so we have to skip error handling if nonzero, and skip EOF
+                 * handling if zero, as it's possible that we didn't manage to
+                 * send anything at all before being interrupted by a
+                 * signal. */
+                if((errno != EAGAIN && errno != EINTR) || bytes_sent == 0) {
+                    n = -1;
+                }
+            }
+        }
+#elif defined(__sun) && defined(__SVR4) && defined(HAVE_SENDFILEV)
+        {
+            sendfilevec_t sfvec[1];
+            size_t bytes_sent;
+            ssize_t error;
+
+            sfvec[0].sfv_fd = desc->sendfile.dup_file_fd;
+            sfvec[0].sfv_len = bytes_to_send;
+            sfvec[0].sfv_off = offset;
+            sfvec[0].sfv_flag = 0;
+
+            error = sendfilev(desc->inet.s, sfvec, 1, &bytes_sent);
+            n = bytes_sent;
+
+            if(error < 0) {
+                if(errno == EINVAL) {
+                    /* On some solaris versions (I've seen it on SunOS 5.10),
+                     * using a sfv_len larger than the filesize will result in
+                     * a (-1 && errno == EINVAL). We translate this to a
+                     * successful send of the data.*/
+                } else {
+                    /* EAGAIN/EINTR behavior is identical to *BSD. */
+                    if((errno != EAGAIN && errno != EINTR) || bytes_sent == 0) {
+                        n = -1;
+                    }
+                }
+            }
+        }
+#else
+        #error "Unsupported sendfile syscall; update configure test."
+#endif
+
+        if (n > 0) {
+            desc->sendfile.bytes_sent += n;
+            desc->sendfile.offset += n;
+            desc->sendfile.length -= n;
+        } else if (n == 0) {
+            /* EOF. */
+            desc->sendfile.length = 0;
+            break;
+        } else if (IS_SOCKET_ERROR(n) && sock_errno() != EINTR) {
+            if (sock_errno() != ERRNO_BLOCK) {
+                goto socket_error;
+            }
+
+#ifdef __WIN32__
+            desc->inet.send_would_block = 1;
+#endif
+            break;
+        }
+    }
+
+    if (desc->sendfile.length == 0) {
+        tcp_sendfile_completed(desc);
+    }
+
+    goto done;
+
+socket_error: {
+        int socket_errno = sock_errno();
+
+        DEBUGF(("tcp_inet_sendfile(%ld): send errno = %d (errno %d)\r\n",
+            (long)desc->inet.port, socket_errno, errno));
+
+        result = tcp_send_error(desc, socket_errno);
+        tcp_sendfile_aborted(desc, socket_errno);
+
+        goto done;
+    }
+
+done:
+    DEBUGF(("tcp_inet_sendfile(%ld) }\r\n", (long)desc->inet.port));
+    return result;
+}
+#endif /* HAVE_SENDFILE */
+
 /* socket ready for ouput:
 ** 1. INET_STATE_CONNECTING => non block connect ?
 ** 2. INET_STATE_CONNECTED  => write output
@@ -10892,7 +11251,14 @@ static int tcp_inet_output(tcp_descriptor* desc, HANDLE event)
 	async_ok(INETP(desc));
     }
     else if (IS_CONNECTED(INETP(desc))) {
-	for (;;) {
+
+#ifdef HAVE_SENDFILE
+        if(desc->tcp_add_flags & TCP_ADDF_SENDFILE) {
+            return tcp_inet_sendfile(desc);
+        }
+#endif
+
+        for (;;) {
 	    int vsize;
 	    ssize_t n;
 	    SysIOVec* iov;