diff mbox

[v2,3/3] posix: Implement preadv2 and pwritev2

Message ID 1493735612-26045-3-git-send-email-adhemerval.zanella@linaro.org
State New
Headers show

Commit Message

Adhemerval Zanella May 2, 2017, 2:33 p.m. UTC
Changes from previous version:

  * Add preadv2 and pwritev2 documentation.

  * Define all new symbols under __USE_GNU instead fo __USE_MISC since
    they are Linux specific symbols only current provided by GLIBC.

  * Return -1 and set errno to EINVAL for flags different than 0 for
    sysdeps/posix implementation.

--

This patch adds support of preadv2 and pwritev2 which are similar to
preadv/pwritev but adds an extra flag argument.  As for preadv/pwritev
both interfaces are added a non-standard standard GNU API.

On default 'posix' implementation trying to emulate the Linux supported
flags is troublesome:

   * We can not temporary change the file state of the O_DSYNC and O_SYNC
     flags to emulate RWF_{D}SYNC (attempts to change the state of using
     fcntl are silently ignored).

   * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
     semantic not provided by any other flag (O_NONBLOCK for instance).

So default implementation just ignore the flag argument and calls generic
preadv/pwritev.

The Linux one uses the preadv2/pwritev2 syscall if defined, otherwise it
call preadv/writev.  Instead of using the previous __ASSUME_* to
unconditionally issue the syscall (and avoid building the fallback routine),
it call pread/write if the preadv2/pwritev2 syscalls fails.  The idea
is just avoid adding another __ASSUME_* and checking each architecture
on every kernel bump and simplify code conditionals.

Checked on x86_64-linux-gnu and on i686-linux-gnu and a check with
run-built-tests=no on aarch64-linux-gnu, alpha-linux-gnu, arm-linux-gnueabihf,
ia64-linux-gnu, m68k-linux-gnu, microblaze-linux-gnu, mips{64,64n32}-linux-gnu,
nios2-linux-gnu, powerpc{64,64le}-linux-gnu, s390{x}-linux-gnu,
sparc{64,v9}-linux-gnu, tile{gx,pro}-linux-gnu, and sh4-linux-gnu (all using
gcc 6.3).

	* misc/Makefile (routines): Add preadv2, preadv64v2, pwritev2, and
	pwritev64v2.
	(tests): Add tst-preadvwritev2 and tst-preadvwritev64v2.
	* misc/Versions (GLIBC_2.26): Add preadv2, preadv64v2, pwritev2, and
	pwritev64v2.
	* misc/preadv2.c: New file.
	* misc/preadv64v2.c: Likewise.
	* misc/pwritev2.c: Likewise.
	* misc/pwritev64v2.c: Likewise.
	* misc/tst-preadvwritev2.c: Likewise.
	* misc/tst-preadvwritev64v2.c: Likewise.
	* manual/llio.texi: Add preadv2 and pwritev2 documentation.
	* misc/sys/uio.h [__USE_GNU && !__USE_FILE_OFFSET64] (preadv2): New
	prototype.
	[__USE_GNU && !__USE_FILE_OFFSET64] (pwritev2):	Likewise.
	[__USE_GNU && __USE_FILE_OFFSET64] (preadv64v2): Likewise.
	[__USE_GNU && __USE_FILE_OFFSET64] (pwritev64v2): Likewise.
	* misc/tst-preadvwritev-common.c (PREADV): Define if not defined.
	(PWRITEV): Likewise.
	(do_test_with_offset): Use PREADV and PWRITEV macros and check for
	ENOSYS.
	* nptl/tst-cancel4.c (tf_pwritev2): New test.
	(tf_preadv2): Likewise.
	(tf_fsync): Add tf_pwritev2 and tf_preadv2.
	* sysdeps/posix/preadv2.c: Likewise.
	* sysdeps/posix/preadv64v2.c: Likewise.
	* sysdeps/posix/pwritev2.c: Likewise.
	* sysdeps/posix/pwritev64v2.c: Likewise.
	* sysdeps/unix/sysv/linux/preadv2.c: Likewise.
	* sysdeps/unix/sysv/linux/preadv64v2.c: Likewise.
	* sysdeps/unix/sysv/linux/pwritev2.c: Likewise.
	* sysdeps/unix/sysv/linux/pwritev64v2.c: Likewise.
	* sysdeps/unix/sysv/linux/preadv.c (preadv): Add libc_hidden_def.
	* sysdeps/unix/sysv/linux/preadv64.c (preadv64): Likewise.
	* sysdeps/unix/sysv/linux/pwritev.c (pwritev): Likewise.
	* sysdeps/unix/sysv/linux/pwritev64.c (pwritev64): Likewise.
	* sysdeps/unix/sysv/linux/bits/uio.h: Add supported preadv2/pwritev2
	support flags on Linux.
	* sysdeps/unix/sysv/linux/aarch64/libc.abilist (GLIBC_2.26): Add
	preadv2, preadv64v2, pwritev2, pwritev64v2.
	* sysdeps/unix/sysv/linux/alpha/libc.abilist (GLIBC_2.26): Likewise.
	* sysdeps/unix/sysv/linux/arm/libc.abilist (GLIBC_2.26): Likewise.
	* sysdeps/unix/sysv/linux/hppa/libc.abilist (GLIBC_2.26): Likewise.
	* sysdeps/unix/sysv/linux/i386/libc.abilist (GLIBC_2.26): Likewise.
	* sysdeps/unix/sysv/linux/ia64/libc.abilist (GLIBC_2.26): Likewise.
	* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/microblaze/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/nios2/libc.abilist (GLIBC_2.26): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
	(GLIBC_2.26): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
	(GLIBC_2.26): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
	(GLIBC_2.26): Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/sh/libc.abilist (GLIBC_2.26): Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/sysv/linux/tile/tilegx/tilegx32/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/sysv/linux/tile/tilegx/tilegx64/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist (GLIBC_2.26):
	Likewise.
	* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist (GLIBC_2.26):
	Likewise.

---
 ChangeLog                                          | 88 +++++++++++++++++++
 include/sys/uio.h                                  |  6 ++
 manual/llio.texi                                   | 98 ++++++++++++++++++++++
 misc/Makefile                                      |  5 +-
 misc/Versions                                      |  3 +
 misc/preadv2.c                                     | 30 +++++++
 misc/preadv64v2.c                                  | 30 +++++++
 misc/pwritev2.c                                    | 30 +++++++
 misc/pwritev64v2.c                                 | 30 +++++++
 misc/sys/uio.h                                     | 41 +++++++++
 misc/tst-preadvwritev-common.c                     | 19 ++++-
 misc/tst-preadvwritev2.c                           | 31 +++++++
 misc/tst-preadvwritev64v2.c                        | 33 ++++++++
 nptl/tst-cancel4.c                                 | 71 ++++++++++++++++
 sysdeps/posix/preadv2.c                            | 38 +++++++++
 sysdeps/posix/preadv64v2.c                         | 37 ++++++++
 sysdeps/posix/pwritev2.c                           | 38 +++++++++
 sysdeps/posix/pwritev64v2.c                        | 38 +++++++++
 sysdeps/unix/sysv/linux/aarch64/libc.abilist       |  5 ++
 sysdeps/unix/sysv/linux/alpha/libc.abilist         |  5 ++
 sysdeps/unix/sysv/linux/arm/libc.abilist           |  5 ++
 sysdeps/unix/sysv/linux/bits/uio.h                 |  6 ++
 sysdeps/unix/sysv/linux/hppa/libc.abilist          |  5 ++
 sysdeps/unix/sysv/linux/i386/libc.abilist          |  5 ++
 sysdeps/unix/sysv/linux/ia64/libc.abilist          |  5 ++
 sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist |  5 ++
 sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist   |  5 ++
 sysdeps/unix/sysv/linux/microblaze/libc.abilist    |  5 ++
 .../unix/sysv/linux/mips/mips32/fpu/libc.abilist   |  5 ++
 .../unix/sysv/linux/mips/mips32/nofpu/libc.abilist |  5 ++
 .../unix/sysv/linux/mips/mips64/n32/libc.abilist   |  5 ++
 .../unix/sysv/linux/mips/mips64/n64/libc.abilist   |  5 ++
 sysdeps/unix/sysv/linux/nios2/libc.abilist         |  5 ++
 .../sysv/linux/powerpc/powerpc32/fpu/libc.abilist  |  5 ++
 .../linux/powerpc/powerpc32/nofpu/libc.abilist     |  5 ++
 .../sysv/linux/powerpc/powerpc64/libc-le.abilist   |  5 ++
 .../unix/sysv/linux/powerpc/powerpc64/libc.abilist |  5 ++
 sysdeps/unix/sysv/linux/preadv.c                   |  2 +
 sysdeps/unix/sysv/linux/preadv2.c                  | 51 +++++++++++
 sysdeps/unix/sysv/linux/preadv64.c                 |  2 +
 sysdeps/unix/sysv/linux/preadv64v2.c               | 51 +++++++++++
 sysdeps/unix/sysv/linux/pwrite64.c                 |  1 +
 sysdeps/unix/sysv/linux/pwritev.c                  |  2 +
 sysdeps/unix/sysv/linux/pwritev2.c                 | 47 +++++++++++
 sysdeps/unix/sysv/linux/pwritev64.c                |  2 +
 sysdeps/unix/sysv/linux/pwritev64v2.c              | 51 +++++++++++
 sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist  |  5 ++
 sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist  |  5 ++
 sysdeps/unix/sysv/linux/sh/libc.abilist            |  5 ++
 sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist |  5 ++
 sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist |  5 ++
 .../sysv/linux/tile/tilegx/tilegx32/libc.abilist   |  5 ++
 .../sysv/linux/tile/tilegx/tilegx64/libc.abilist   |  5 ++
 sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist  |  5 ++
 sysdeps/unix/sysv/linux/x86_64/64/libc.abilist     |  5 ++
 sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist    |  5 ++
 56 files changed, 1016 insertions(+), 5 deletions(-)
 create mode 100644 misc/preadv2.c
 create mode 100644 misc/preadv64v2.c
 create mode 100644 misc/pwritev2.c
 create mode 100644 misc/pwritev64v2.c
 create mode 100644 misc/tst-preadvwritev2.c
 create mode 100644 misc/tst-preadvwritev64v2.c
 create mode 100644 sysdeps/posix/preadv2.c
 create mode 100644 sysdeps/posix/preadv64v2.c
 create mode 100644 sysdeps/posix/pwritev2.c
 create mode 100644 sysdeps/posix/pwritev64v2.c
 create mode 100644 sysdeps/unix/sysv/linux/preadv2.c
 create mode 100644 sysdeps/unix/sysv/linux/preadv64v2.c
 create mode 100644 sysdeps/unix/sysv/linux/pwritev2.c
 create mode 100644 sysdeps/unix/sysv/linux/pwritev64v2.c

Comments

Christoph Hellwig May 2, 2017, 2:37 p.m. UTC | #1
On Tue, May 02, 2017 at 11:33:32AM -0300, Adhemerval Zanella wrote:
> So default implementation just ignore the flag argument and calls generic
> preadv/pwritev.

Please don't do that, it's actively dangerous.  Just fail the call.
Adhemerval Zanella May 2, 2017, 5:37 p.m. UTC | #2
On 02/05/2017 11:37, Christoph Hellwig wrote:
> On Tue, May 02, 2017 at 11:33:32AM -0300, Adhemerval Zanella wrote:
>> So default implementation just ignore the flag argument and calls generic
>> preadv/pwritev.
> 
> Please don't do that, it's actively dangerous.  Just fail the call.
> 

This a misleading commit comment from my part (I forgot to actually update
the commit log).  In fact, I am following the suggestion from Zack and
returning EINVAL for unsupported flags in generic implementation (which
are currently none).  So the flags are not really ignored, but rather
it will make the default implementation fails.

[1] https://sourceware.org/ml/libc-alpha/2017-04/msg00565.html
Christoph Hellwig May 2, 2017, 6 p.m. UTC | #3
On Tue, May 02, 2017 at 02:37:47PM -0300, Adhemerval Zanella wrote:
> This a misleading commit comment from my part (I forgot to actually update
> the commit log).  In fact, I am following the suggestion from Zack and
> returning EINVAL for unsupported flags in generic implementation (which
> are currently none).  So the flags are not really ignored, but rather
> it will make the default implementation fails.

Note that the kernel returns -EOPNOTSUPP for not supported features,
it would be good to have the same behavior in glibc.
Zack Weinberg May 2, 2017, 6:01 p.m. UTC | #4
On Tue, May 2, 2017 at 1:37 PM, Adhemerval Zanella
<adhemerval.zanella@linaro.org> wrote:
> On 02/05/2017 11:37, Christoph Hellwig wrote:
>> On Tue, May 02, 2017 at 11:33:32AM -0300, Adhemerval Zanella wrote:
>>> So default implementation just ignore the flag argument and calls generic
>>> preadv/pwritev.
>>
>> Please don't do that, it's actively dangerous.  Just fail the call.
>
> This a misleading commit comment from my part (I forgot to actually update
> the commit log).  In fact, I am following the suggestion from Zack and
> returning EINVAL for unsupported flags in generic implementation (which
> are currently none).

This is true for the stub implementation (always returns -1/ENOSYS)
and the sysdeps/posix implementation (returns -1/EINVAL if flags is
nonzero, else calls preadv/pwritev, which is the Right Thing) ... but
the sysdeps/unix/sysv/linux implementation appears to do the wrong
thing when kernel support isn't available:

+ssize_t
+preadv2 (int fd, const struct iovec *vector, int count, off_t offset,
+ int flags)
+{
+# ifdef __NR_preadv2
+  ssize_t result = SYSCALL_CANCEL (preadv2, fd, vector, count,
+   LO_HI_LONG (offset), flags);
+  if (result >= 0 || errno != ENOSYS)
+    return result;
+# endif
+  /* Trying to emulate the preadv2 syscall flags is troublesome:
+
+     * We can not temporary change the file state of the O_DSYNC and O_SYNC
+       flags to emulate RWF_{D}SYNC (attempts to change the state of using
+       fcntl silently ignored).
+
+     * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
+       semantic not provided by any other flag (O_NONBLOCK for instance).
+
+     So for generic case just ignore the flags can call preadv directly.  */
+  return preadv (fd, vector, count, offset);
+}

The fallback logic needs to check whether flags is nonzero before
calling preadv.

(Relying on the kernel to reject unrecognized flags, when the syscall
*is* available, seems reasonable to me.)

zw
Adhemerval Zanella May 2, 2017, 6:24 p.m. UTC | #5
On 02/05/2017 15:01, Zack Weinberg wrote:
> On Tue, May 2, 2017 at 1:37 PM, Adhemerval Zanella
> <adhemerval.zanella@linaro.org> wrote:
>> On 02/05/2017 11:37, Christoph Hellwig wrote:
>>> On Tue, May 02, 2017 at 11:33:32AM -0300, Adhemerval Zanella wrote:
>>>> So default implementation just ignore the flag argument and calls generic
>>>> preadv/pwritev.
>>>
>>> Please don't do that, it's actively dangerous.  Just fail the call.
>>
>> This a misleading commit comment from my part (I forgot to actually update
>> the commit log).  In fact, I am following the suggestion from Zack and
>> returning EINVAL for unsupported flags in generic implementation (which
>> are currently none).
> 
> This is true for the stub implementation (always returns -1/ENOSYS)
> and the sysdeps/posix implementation (returns -1/EINVAL if flags is
> nonzero, else calls preadv/pwritev, which is the Right Thing) ... but
> the sysdeps/unix/sysv/linux implementation appears to do the wrong
> thing when kernel support isn't available:
> 
> +ssize_t
> +preadv2 (int fd, const struct iovec *vector, int count, off_t offset,
> + int flags)
> +{
> +# ifdef __NR_preadv2
> +  ssize_t result = SYSCALL_CANCEL (preadv2, fd, vector, count,
> +   LO_HI_LONG (offset), flags);
> +  if (result >= 0 || errno != ENOSYS)
> +    return result;
> +# endif
> +  /* Trying to emulate the preadv2 syscall flags is troublesome:
> +
> +     * We can not temporary change the file state of the O_DSYNC and O_SYNC
> +       flags to emulate RWF_{D}SYNC (attempts to change the state of using
> +       fcntl silently ignored).
> +
> +     * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
> +       semantic not provided by any other flag (O_NONBLOCK for instance).
> +
> +     So for generic case just ignore the flags can call preadv directly.  */
> +  return preadv (fd, vector, count, offset);
> +}
> 
> The fallback logic needs to check whether flags is nonzero before
> calling preadv.
> 
> (Relying on the kernel to reject unrecognized flags, when the syscall
> *is* available, seems reasonable to me.)
> 
> zw

Indeed, it needs update as for default sysdeps/posix one.  I will add, along
with a missing explanation about not using __ASSUME for this implementation
on kernel-features.h (as requested by Joseph).

> 
> Note that the kernel returns -EOPNOTSUPP for not supported features,
> it would be good to have the same behavior in glibc.

Alright, I think it is reasonable returning EOPNOTSUPP for non supported
flags.  I will change is as well and add on documentation.
diff mbox

Patch

diff --git a/include/sys/uio.h b/include/sys/uio.h
index f44ce18..20860bf 100644
--- a/include/sys/uio.h
+++ b/include/sys/uio.h
@@ -7,5 +7,11 @@  extern ssize_t __readv (int __fd, const struct iovec *__iovec,
 			int __count);
 extern ssize_t __writev (int __fd, const struct iovec *__iovec,
 			 int __count);
+
+/* Used for p{read,write}{v64}v2 implementation.  */
+libc_hidden_proto (preadv)
+libc_hidden_proto (preadv64)
+libc_hidden_proto (pwritev)
+libc_hidden_proto (pwritev64)
 #endif
 #endif
diff --git a/manual/llio.texi b/manual/llio.texi
index 6187329..c681a16 100644
--- a/manual/llio.texi
+++ b/manual/llio.texi
@@ -756,6 +756,104 @@  When the source file is compiled using @code{_FILE_OFFSET_BITS == 64} on a
 @code{pwritev} and so transparently replaces the 32 bit interface.
 @end deftypefun
 
+@comment sys/uio.h
+@comment GNU
+@deftypefun ssize_t preadv2 (int @var{fd}, const struct iovec *@var{iov}, int @var{iovcnt}, off_t @var{offset}, int @var{flags})
+@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
+@c This is a syscall for Linux v4.6.  The sysdeps/posix fallback emulation
+@c is also MT-Safe since it calls preadv.
+
+This function is similar to the @code{preadv} function, with the difference
+it adds an extra @var{flags} parameter of type @code{int}.  The supported
+@var{flags} are dependent of the underlying system.  For Linux it supports:
+
+@vtable @code
+@item RWF_HIPRI
+High priority request.  This adds a flag that tells the file system that
+this is a high priority request for which it is worth to poll the hardware.
+The flag is purely advisory and can be ignored if not supported.  The
+@var{fd} must be opened using @code{O_DIRECT}.
+
+@item RWF_DSYNC
+Per-IO synchronization as if the file was opened with @code{O_DSYNC} flag.
+
+@item RWF_SYNC
+Per-IO synchronization as if the file was opened with @code{O_SYNC} flag.
+@end vtable
+
+When the source file is compiled with @code{_FILE_OFFSET_BITS == 64} the
+@code{preadv2} function is in fact @code{preadv64v2} and the type
+@code{off_t} has 64 bits, which makes it possible to handle files up to
+@twoexp{63} bytes in length.
+
+The return value is a count of bytes (@emph{not} buffers) read, @math{0}
+indicating end-of-file, or @math{-1} indicating an error.  The possible
+errors are the same as in @code{preadv}.
+@end deftypefun
+
+@comment unistd.h
+@comment GNU
+@deftypefun ssize_t preadv64v2 (int @var{fd}, const struct iovec *@var{iov}, int @var{iovcnt}, off64_t @var{offset}, int @var{flags})
+@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
+@c This is a syscall for Linux v4.6.  The sysdeps/posix fallback emulation
+@c is also MT-Safe since it calls preadv.
+
+This function is similar to the @code{preadv2} function with the difference
+is that the @var{offset} parameter is of type @code{off64_t} instead of
+@code{off_t}.  It makes it possible on 32 bit machines to address
+files larger than @twoexp{31} bytes and up to @twoexp{63} bytes.  The
+file descriptor @code{filedes} must be opened using @code{open64} since
+otherwise the large offsets possible with @code{off64_t} will lead to
+errors with a descriptor in small file mode.
+
+When the source file is compiled using @code{_FILE_OFFSET_BITS == 64} on a
+32 bit machine this function is actually available under the name
+@code{preadv2} and so transparently replaces the 32 bit interface.
+@end deftypefun
+
+
+@comment sys/uio.h
+@comment GNU
+@deftypefun ssize_t pwritev2 (int @var{fd}, const struct iovec *@var{iov}, int @var{iovcnt}, off_t @var{offset}, int @var{flags})
+@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
+@c This is a syscall for Linux v4.6.  The sysdeps/posix fallback emulation
+@c is also MT-Safe since it calls pwritev.
+
+This function is similar to the @code{pwritev} function, with the difference
+it adds an extra @var{flags} parameter of type @code{int}.  The supported
+@var{flags} are dependent of the underlying system and for Linux it supports
+the same ones as for @code{preadv2}.
+
+When the source file is compiled with @code{_FILE_OFFSET_BITS == 64} the
+@code{pwritev2} function is in fact @code{pwritev64v2} and the type
+@code{off_t} has 64 bits, which makes it possible to handle files up to
+@twoexp{63} bytes in length.
+
+The return value is a count of bytes (@emph{not} buffers) write, @math{0}
+indicating end-of-file, or @math{-1} indicating an error.  The possible
+errors are the same as in @code{pwritev}.
+@end deftypefun
+
+@comment unistd.h
+@comment GNU
+@deftypefun ssize_t pwritev64v2 (int @var{fd}, const struct iovec *@var{iov}, int @var{iovcnt}, off64_t @var{offset}, int @var{flags})
+@safety{@prelim{}@mtsafe{}@assafe{}@acsafe{}}
+@c This is a syscall for Linux v4.6.  The sysdeps/posix fallback emulation
+@c is also MT-Safe since it calls pwritev.
+
+This function is similar to the @code{pwritev2} function with the difference
+is that the @var{offset} parameter is of type @code{off64_t} instead of
+@code{off_t}.  It makes it possible on 32 bit machines to address
+files larger than @twoexp{31} bytes and up to @twoexp{63} bytes.  The
+file descriptor @code{filedes} must be opened using @code{open64} since
+otherwise the large offsets possible with @code{off64_t} will lead to
+errors with a descriptor in small file mode.
+
+When the source file is compiled using @code{_FILE_OFFSET_BITS == 64} on a
+32 bit machine this function is actually available under the name
+@code{pwritev2} and so transparently replaces the 32 bit interface.
+@end deftypefun
+
 
 @node File Position Primitive
 @section Setting the File Position of a Descriptor
diff --git a/misc/Makefile b/misc/Makefile
index 622da67..bed46d7 100644
--- a/misc/Makefile
+++ b/misc/Makefile
@@ -39,6 +39,7 @@  headers	:= sys/uio.h bits/uio.h sys/ioctl.h bits/ioctls.h bits/ioctl-types.h \
 
 routines := brk sbrk sstk ioctl \
 	    readv writev preadv preadv64 pwritev pwritev64 \
+	    preadv2 preadv64v2 pwritev2 pwritev64v2 \
 	    setreuid setregid \
 	    seteuid setegid \
 	    getpagesize \
@@ -79,7 +80,9 @@  gpl2lgpl := error.c error.h
 tests := tst-dirname tst-tsearch tst-fdset tst-efgcvt tst-mntent tst-hsearch \
 	 tst-error1 tst-pselect tst-insremque tst-mntent2 bug-hsearch1 \
 	 tst-mntent-blank-corrupt tst-mntent-blank-passno bug18240 \
-	 tst-preadvwritev tst-preadvwritev64 tst-makedev tst-empty \
+	 tst-preadvwritev tst-preadvwritev64 tst-preadvwritev2 \
+	 tst-preadvwritev64v2 \
+	 tst-makedev tst-empty \
 	 tst-atomic tst-atomic-long
 tests-static := tst-empty
 
diff --git a/misc/Versions b/misc/Versions
index f2c90ff..bafda78 100644
--- a/misc/Versions
+++ b/misc/Versions
@@ -155,6 +155,9 @@  libc {
   GLIBC_2.25 {
     gnu_dev_major; gnu_dev_minor; gnu_dev_makedev;
   }
+  GLIBC_2.26 {
+    preadv2; preadv64v2; pwritev2; pwritev64v2;
+  }
   GLIBC_PRIVATE {
     __madvise;
     __mktemp;
diff --git a/misc/preadv2.c b/misc/preadv2.c
new file mode 100644
index 0000000..a62dcaa
--- /dev/null
+++ b/misc/preadv2.c
@@ -0,0 +1,30 @@ 
+/* Default implementation of preadv2.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sys/uio.h>
+
+/* Same as preadv but with an additional flags argument.  */
+ssize_t
+preadv2 (int fd, const struct iovec *vector, int count, off_t offset,
+	 int flags)
+{
+  __set_errno (ENOSYS);
+  return -1;
+}
+
+stub_warning (preadv2)
diff --git a/misc/preadv64v2.c b/misc/preadv64v2.c
new file mode 100644
index 0000000..a802c2f
--- /dev/null
+++ b/misc/preadv64v2.c
@@ -0,0 +1,30 @@ 
+/* Default implementation of preadv2 (LFS version).
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sys/uio.h>
+
+/* Same as preadv64 but with an addional flag argument.  */
+ssize_t
+preadv64v2 (int fd, const struct iovec *vector, int count, off64_t offset,
+	    int flags)
+{
+  __set_errno (ENOSYS);
+  return -1;
+}
+
+stub_warning (preadv64v2)
diff --git a/misc/pwritev2.c b/misc/pwritev2.c
new file mode 100644
index 0000000..b9e0727
--- /dev/null
+++ b/misc/pwritev2.c
@@ -0,0 +1,30 @@ 
+/* Default implementation of pwritev2.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sys/uio.h>
+
+/* Same as pwritev but with an additional flags argument.  */
+ssize_t
+pwritev2 (int fd, const struct iovec *vector, int count, off_t offset,
+	  int flags)
+{
+  __set_errno (ENOSYS);
+  return -1;
+}
+
+stub_warning (pwritev2)
diff --git a/misc/pwritev64v2.c b/misc/pwritev64v2.c
new file mode 100644
index 0000000..1f874f0
--- /dev/null
+++ b/misc/pwritev64v2.c
@@ -0,0 +1,30 @@ 
+/* Default implementation of pwritev2 (LFS version).
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sys/uio.h>
+
+/* Same as preadv64 but with an addional flag argument.  */
+ssize_t
+pwritev64v2 (int fd, const struct iovec *vector, int count, off64_t offset,
+	     int flags)
+{
+  __set_errno (ENOSYS);
+  return -1;
+}
+
+stub_warning (pwritev64v2)
diff --git a/misc/sys/uio.h b/misc/sys/uio.h
index e80f013..66c22f0 100644
--- a/misc/sys/uio.h
+++ b/misc/sys/uio.h
@@ -76,6 +76,7 @@  extern ssize_t preadv (int __fd, const struct iovec *__iovec, int __count,
    __THROW.  */
 extern ssize_t pwritev (int __fd, const struct iovec *__iovec, int __count,
 			__off_t __offset) __wur;
+
 # else
 #  ifdef __REDIRECT
 extern ssize_t __REDIRECT (preadv, (int __fd, const struct iovec *__iovec,
@@ -117,6 +118,46 @@  extern ssize_t pwritev64 (int __fd, const struct iovec *__iovec, int __count,
 # endif
 #endif	/* Use misc.  */
 
+
+#ifdef __USE_GNU
+# ifndef __USE_FILE_OFFSET64
+/* Same as preadv but with an additional flag argumenti defined at uio.h.  */
+extern ssize_t preadv2 (int __fp, const struct iovec *__iovec, int __count,
+			__off_t __offset, int ___flags) __wur;
+
+/* Same as preadv but with an additional flag argument defined at uio.h.  */
+extern ssize_t pwritev2 (int __fd, const struct iovec *__iodev, int __count,
+			 __off_t __offset, int __flags) __wur;
+
+# else
+#  ifdef __REDIRECT
+extern ssize_t __REDIRECT (pwritev2, (int __fd, const struct iovec *__iovec,
+				      int __count, __off64_t __offset,
+				      int __flags),
+			   pwritev64v2) __wur;
+extern ssize_t __REDIRECT (preadv2, (int __fd, const struct iovec *__iovec,
+				     int __count, __off64_t __offset,
+				     int __flags),
+			   preadv64v2) __wur;
+#  else
+#   define preadv2 preadv64v2
+#   define pwritev2 pwritev64v2
+#  endif
+# endif
+
+# ifdef __USE_LARGEFILE64
+/* Same as preadv but with an additional flag argumenti defined at uio.h.  */
+extern ssize_t preadv64v2 (int __fp, const struct iovec *__iovec,
+			   int __count, __off64_t __offset,
+			   int ___flags) __wur;
+
+/* Same as preadv but with an additional flag argument defined at uio.h.  */
+extern ssize_t pwritev64v2 (int __fd, const struct iovec *__iodev,
+			    int __count, __off64_t __offset,
+			    int __flags) __wur;
+# endif
+#endif /* Use GNU.  */
+
 __END_DECLS
 
 #endif /* sys/uio.h */
diff --git a/misc/tst-preadvwritev-common.c b/misc/tst-preadvwritev-common.c
index 5540dfb..676d495 100644
--- a/misc/tst-preadvwritev-common.c
+++ b/misc/tst-preadvwritev-common.c
@@ -18,6 +18,7 @@ 
 
 #include <stdio.h>
 #include <stdint.h>
+#include <errno.h>
 #include <string.h>
 #include <sys/uio.h>
 #include <sys/stat.h>
@@ -39,6 +40,16 @@  do_prepare (int argc, char **argv)
 }
 #define PREPARE do_prepare
 
+#ifndef PREADV
+# define PREADV(__fd, __iov, __iovcnt, __offset) \
+  preadv (__fd, __iov, __iovcnt, __offset)
+#endif
+
+#ifndef PWRITEV
+# define PWRITEV(__fd, __iov, __iovcnt, __offset) \
+  pwritev (__fd, __iov, __iovcnt, __offset)
+#endif
+
 static int
 do_test_with_offset (off_t offset)
 {
@@ -58,13 +69,13 @@  do_test_with_offset (off_t offset)
   iov[1].iov_base = buf2;
   iov[1].iov_len = sizeof buf2;
 
-  ret = pwritev (temp_fd, iov, 2, offset);
+  ret = PWRITEV (temp_fd, iov, 2, offset);
   if (ret == -1)
     FAIL_RET ("first pwritev returned -1");
   if (ret != (sizeof buf1 + sizeof buf2))
     FAIL_RET ("first pwritev returned an unexpected value");
 
-  ret = pwritev (temp_fd, iov, 2, sizeof buf1 + sizeof buf2 + offset);
+  ret = PWRITEV (temp_fd, iov, 2, sizeof buf1 + sizeof buf2 + offset);
   if (ret == -1)
     FAIL_RET ("second pwritev returned -1");
   if (ret != (sizeof buf1 + sizeof buf2))
@@ -82,7 +93,7 @@  do_test_with_offset (off_t offset)
   iov[1].iov_len = sizeof buf4;
 
   /* Now read two buffer with 32 and 64 bytes respectively.  */
-  ret = preadv (temp_fd, iov, 2, offset);
+  ret = PREADV (temp_fd, iov, 2, offset);
   if (ret == -1)
     FAIL_RET ("first preadv returned -1");
   if (ret != (sizeof buf3 + sizeof buf4))
@@ -93,7 +104,7 @@  do_test_with_offset (off_t offset)
   if (memcmp (buf2, buf4, sizeof buf2) != 0)
     FAIL_RET ("second buffer from first preadv different than expected");
 
-  ret = preadv (temp_fd, iov, 2, sizeof buf3 + sizeof buf4 + offset);
+  ret = PREADV (temp_fd, iov, 2, sizeof buf3 + sizeof buf4 + offset);
   if (ret == -1)
     FAIL_RET ("second preadv returned -1");
   if (ret != (sizeof buf3 + sizeof buf4))
diff --git a/misc/tst-preadvwritev2.c b/misc/tst-preadvwritev2.c
new file mode 100644
index 0000000..cf36272
--- /dev/null
+++ b/misc/tst-preadvwritev2.c
@@ -0,0 +1,31 @@ 
+/* Tests for preadv2 and pwritev2.
+   Copyright (C) 2016-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define PREADV(__fd, __iov, __iovcnt, __offset) \
+  preadv2 (__fd, __iov, __iovcnt, __offset, 0)
+
+#define PWRITEV(__fd, __iov, __iovcnt, __offset) \
+  pwritev2 (__fd, __iov, __iovcnt, __offset, 0)
+
+#include "tst-preadvwritev-common.c"
+
+static int
+do_test (void)
+{
+  return do_test_with_offset (0);
+}
diff --git a/misc/tst-preadvwritev64v2.c b/misc/tst-preadvwritev64v2.c
new file mode 100644
index 0000000..8d0c48e
--- /dev/null
+++ b/misc/tst-preadvwritev64v2.c
@@ -0,0 +1,33 @@ 
+/* Tests for preadv2 and pwritev2 (LFS version).
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define _FILE_OFFSET_BITS 64
+
+#define PREADV(__fd, __iov, __iovcnt, __offset) \
+  preadv2 (__fd, __iov, __iovcnt, __offset, 0)
+
+#define PWRITEV(__fd, __iov, __iovcnt, __offset) \
+  pwritev2 (__fd, __iov, __iovcnt, __offset, 0)
+
+#include "tst-preadvwritev-common.c"
+
+static int
+do_test (void)
+{
+  return do_test_with_offset (0);
+}
diff --git a/nptl/tst-cancel4.c b/nptl/tst-cancel4.c
index e66961f..7a560a1 100644
--- a/nptl/tst-cancel4.c
+++ b/nptl/tst-cancel4.c
@@ -1079,6 +1079,75 @@  tf_pwritev (void *arg)
 }
 
 static void *
+tf_pwritev2 (void *arg)
+{
+  int fd;
+
+  if (arg == NULL)
+    /* XXX If somebody can provide a portable test case in which pwritev2
+       blocks we can enable this test to run in both rounds.  */
+    abort ();
+
+  errno = 0;
+
+  char fname[] = "/tmp/tst-cancel4-fd-XXXXXX";
+  tempfd = fd = mkstemp (fname);
+  if (fd == -1)
+    FAIL_EXIT1 ("mkstemp: %m");
+  unlink (fname);
+
+  xpthread_barrier_wait (&b2);
+
+  xpthread_barrier_wait (&b2);
+
+  ssize_t s;
+  pthread_cleanup_push (cl, NULL);
+
+  char buf[WRITE_BUFFER_SIZE];
+  memset (buf, '\0', sizeof (buf));
+  struct iovec iov[1] = { [0] = { .iov_base = buf, .iov_len = sizeof (buf) } };
+  s = pwritev2 (fd, iov, 1, 0, 0);
+
+  pthread_cleanup_pop (0);
+
+  FAIL_EXIT1 ("pwritev2 returns with %zd", s);
+}
+
+static void *
+tf_preadv2 (void *arg)
+{
+  int fd;
+
+  if (arg == NULL)
+    /* XXX If somebody can provide a portable test case in which preadv2
+       blocks we can enable this test to run in both rounds.  */
+    abort ();
+
+  errno = 0;
+
+  char fname[] = "/tmp/tst-cancel4-fd-XXXXXX";
+  tempfd = fd = mkstemp (fname);
+  if (fd == -1)
+    FAIL_EXIT1 ("mkstemp failed: %m");
+  unlink (fname);
+
+  xpthread_barrier_wait (&b2);
+
+  xpthread_barrier_wait (&b2);
+
+  ssize_t s;
+  pthread_cleanup_push (cl, NULL);
+
+  char buf[100];
+  struct iovec iov[1] = { [0] = { .iov_base = buf, .iov_len = sizeof (buf) } };
+  s = preadv2 (fd, iov, 1, 0, 0);
+
+  pthread_cleanup_pop (0);
+
+  FAIL_EXIT1 ("preadv2 returns with %zd", s);
+}
+
+static void *
 tf_fsync (void *arg)
 {
   if (arg == NULL)
@@ -1473,7 +1542,9 @@  struct cancel_tests tests[] =
   ADD_TEST (recvfrom, 2, 0),
   ADD_TEST (recvmsg, 2, 0),
   ADD_TEST (preadv, 2, 1),
+  ADD_TEST (preadv2, 2, 1),
   ADD_TEST (pwritev, 2, 1),
+  ADD_TEST (pwritev2, 2, 1),
   ADD_TEST (open, 2, 1),
   ADD_TEST (close, 2, 1),
   ADD_TEST (pread, 2, 1),
diff --git a/sysdeps/posix/preadv2.c b/sysdeps/posix/preadv2.c
new file mode 100644
index 0000000..814b6d0
--- /dev/null
+++ b/sysdeps/posix/preadv2.c
@@ -0,0 +1,38 @@ 
+/* Generic version of preadv2.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <unistd.h>
+#include <sys/uio.h>
+
+#ifndef __OFF_T_MATCHES_OFF64_T
+
+/* Since we define no flags for preadv2 just route to preadv.  */
+ssize_t
+preadv2 (int fd, const struct iovec *vector, int count, OFF_T offset,
+	 int flags)
+{
+  if (flags != 0)
+    {
+      __set_errno (EINVAL);
+      return -1;
+    }
+
+  return preadv (fd, vector, count, offset);
+}
+
+#endif
diff --git a/sysdeps/posix/preadv64v2.c b/sysdeps/posix/preadv64v2.c
new file mode 100644
index 0000000..74a8a90
--- /dev/null
+++ b/sysdeps/posix/preadv64v2.c
@@ -0,0 +1,37 @@ 
+/* Generic version of preadv2.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <unistd.>
+#include <sys/uio.h>
+
+ssize_t
+preadv64v2 (int fd, const struct iovec *vector, int count, OFF_T offset,
+	    int flags)
+{
+  if (flags != 0)
+    {
+      __set_errno (EINVAL);
+      return -1;
+    }
+
+  return preadv64 (fd, vector, count, offset);
+}
+
+#ifdef __OFF_T_MATCHES_OFF64_T
+strong_alias (preadv64v2, preadv2)
+#endif
diff --git a/sysdeps/posix/pwritev2.c b/sysdeps/posix/pwritev2.c
new file mode 100644
index 0000000..e6b3768
--- /dev/null
+++ b/sysdeps/posix/pwritev2.c
@@ -0,0 +1,38 @@ 
+/* Generic version of pwritev2.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <unistd.h>
+#include <sys/uio.h>
+
+#ifndef __OFF_T_MATCHES_OFF64_T
+
+/* Since we define no flags for pwritev2 just route to pwritev.  */
+ssize_t
+pwritev2 (int fd, const struct iovec *vector, int count, OFF_T offset,
+	 int flags)
+{
+  if (flags != 0)
+    {
+      __set_errno (EINVAL);
+      return -1;
+    }
+
+  return pwritev (fd, vector, count, offset);
+}
+
+#endif
diff --git a/sysdeps/posix/pwritev64v2.c b/sysdeps/posix/pwritev64v2.c
new file mode 100644
index 0000000..6a55ebf
--- /dev/null
+++ b/sysdeps/posix/pwritev64v2.c
@@ -0,0 +1,38 @@ 
+/* Generic version of pwritev2.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <unistd.h>
+#include <sys/uio.h>
+
+/* Since we define no flags for pwritev2 just route to pwritev.  */ 
+ssize_t
+pwritev64v2 (int fd, const struct iovec *vector, int count, OFF_T offset,
+	     int flags)
+{
+  if (flags != 0)
+    {
+      __set_errno (EINVAL);
+      return -1;
+    }
+
+  return pwritev64 (fd, vector, count, offset);
+}
+
+#ifdef __OFF_T_MATCHES_OFF64_T
+strong_alias (pwritev64v2, pwritev2)
+#endif
diff --git a/sysdeps/unix/sysv/linux/aarch64/libc.abilist b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
index 58d768c..296f2a5 100644
--- a/sysdeps/unix/sysv/linux/aarch64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
@@ -2097,3 +2097,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
diff --git a/sysdeps/unix/sysv/linux/alpha/libc.abilist b/sysdeps/unix/sysv/linux/alpha/libc.abilist
index 906050d..8006e72 100644
--- a/sysdeps/unix/sysv/linux/alpha/libc.abilist
+++ b/sysdeps/unix/sysv/linux/alpha/libc.abilist
@@ -2008,6 +2008,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/arm/libc.abilist b/sysdeps/unix/sysv/linux/arm/libc.abilist
index 66112dd..29f9688 100644
--- a/sysdeps/unix/sysv/linux/arm/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/libc.abilist
@@ -98,6 +98,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.4 GLIBC_2.4 A
 GLIBC_2.4 _Exit F
 GLIBC_2.4 _IO_2_1_stderr_ D 0xa0
diff --git a/sysdeps/unix/sysv/linux/bits/uio.h b/sysdeps/unix/sysv/linux/bits/uio.h
index 1583f04..d5701f8 100644
--- a/sysdeps/unix/sysv/linux/bits/uio.h
+++ b/sysdeps/unix/sysv/linux/bits/uio.h
@@ -69,4 +69,10 @@  extern ssize_t process_vm_writev (pid_t __pid, const struct iovec *__lvec,
 __END_DECLS
 
 # endif
+
+/* Flags for preadv2/pwritev2: */
+#define RWF_HIPRI	0x00000001 /* High priority request.  */
+#define RWF_DSYNC	0x00000002 /* per-IO O_DSYNC.  */
+#define RWF_SYNC	0x00000004 /* per-IO O_SYNC.  */
+
 #endif
diff --git a/sysdeps/unix/sysv/linux/hppa/libc.abilist b/sysdeps/unix/sysv/linux/hppa/libc.abilist
index 3ddadd2..e9cfbaf 100644
--- a/sysdeps/unix/sysv/linux/hppa/libc.abilist
+++ b/sysdeps/unix/sysv/linux/hppa/libc.abilist
@@ -1862,6 +1862,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/i386/libc.abilist b/sysdeps/unix/sysv/linux/i386/libc.abilist
index 977ab90..c6ad3c3 100644
--- a/sysdeps/unix/sysv/linux/i386/libc.abilist
+++ b/sysdeps/unix/sysv/linux/i386/libc.abilist
@@ -2020,6 +2020,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/ia64/libc.abilist b/sysdeps/unix/sysv/linux/ia64/libc.abilist
index c7edb9a..d0055a2 100644
--- a/sysdeps/unix/sysv/linux/ia64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/ia64/libc.abilist
@@ -1884,6 +1884,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
index 450be4e..3777676 100644
--- a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
@@ -99,6 +99,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.4 GLIBC_2.4 A
 GLIBC_2.4 _Exit F
 GLIBC_2.4 _IO_2_1_stderr_ D 0x98
diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
index 9e016bd..8b1f80c 100644
--- a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
@@ -1976,6 +1976,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/microblaze/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/libc.abilist
index 1a455be..d4db9a8 100644
--- a/sysdeps/unix/sysv/linux/microblaze/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/libc.abilist
@@ -2097,3 +2097,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
index 8eb5e66..f430bdb 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
@@ -1951,6 +1951,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
index 416d9ac..a4dca19 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
@@ -1949,6 +1949,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
index f4949e5..0814fa8 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
@@ -1947,6 +1947,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
index c7375ae..a0bdeff 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
@@ -1942,6 +1942,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/nios2/libc.abilist b/sysdeps/unix/sysv/linux/nios2/libc.abilist
index 724a0e3..b201290 100644
--- a/sysdeps/unix/sysv/linux/nios2/libc.abilist
+++ b/sysdeps/unix/sysv/linux/nios2/libc.abilist
@@ -2138,3 +2138,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
index 2dc32b6..6e7ff24 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
@@ -1980,6 +1980,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
index 5658109..19c7c7d 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
@@ -1985,6 +1985,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
index c761221..e94ce38 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
@@ -2185,3 +2185,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
index 265c769..f3daa33 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
@@ -99,6 +99,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 _Exit F
 GLIBC_2.3 _IO_2_1_stderr_ D 0xe0
diff --git a/sysdeps/unix/sysv/linux/preadv.c b/sysdeps/unix/sysv/linux/preadv.c
index ccfe763..a3c8aec 100644
--- a/sysdeps/unix/sysv/linux/preadv.c
+++ b/sysdeps/unix/sysv/linux/preadv.c
@@ -50,4 +50,6 @@  preadv (int fd, const struct iovec *vector, int count, off_t offset)
 #  define OFF_T off_t
 #  include <sysdeps/posix/preadv.c>
 # endif /* __ASSUME_PREADV  */
+
+libc_hidden_def (preadv)
 #endif
diff --git a/sysdeps/unix/sysv/linux/preadv2.c b/sysdeps/unix/sysv/linux/preadv2.c
new file mode 100644
index 0000000..0e28015
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/preadv2.c
@@ -0,0 +1,51 @@ 
+/* Linux implementation of preadv2.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sys/uio.h>
+#include <sysdep-cancel.h>
+
+#ifndef __OFF_T_MATCHES_OFF64_T
+
+# if !defined (__NR_preadv2) && defined (__NR_pread64v2)
+#  define __NR_preadv2 __NR_pread64v2
+# endif
+
+ssize_t
+preadv2 (int fd, const struct iovec *vector, int count, off_t offset,
+	 int flags)
+{
+# ifdef __NR_preadv2
+  ssize_t result = SYSCALL_CANCEL (preadv2, fd, vector, count,
+				   LO_HI_LONG (offset), flags);
+  if (result >= 0 || errno != ENOSYS)
+    return result;
+# endif
+  /* Trying to emulate the preadv2 syscall flags is troublesome:
+
+     * We can not temporary change the file state of the O_DSYNC and O_SYNC
+       flags to emulate RWF_{D}SYNC (attempts to change the state of using
+       fcntl silently ignored).
+
+     * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
+       semantic not provided by any other flag (O_NONBLOCK for instance).
+
+     So for generic case just ignore the flags can call preadv directly.  */
+  return preadv (fd, vector, count, offset);
+}
+
+#endif
diff --git a/sysdeps/unix/sysv/linux/preadv64.c b/sysdeps/unix/sysv/linux/preadv64.c
index 979db95..448dc17 100644
--- a/sysdeps/unix/sysv/linux/preadv64.c
+++ b/sysdeps/unix/sysv/linux/preadv64.c
@@ -48,7 +48,9 @@  preadv64 (int fd, const struct iovec *vector, int count, off64_t offset)
 # define OFF_T off64_t
 # include <sysdeps/posix/preadv.c>
 #endif
+libc_hidden_def (preadv64)
 
 #ifdef __OFF_T_MATCHES_OFF64_T
 strong_alias (preadv64, preadv)
+libc_hidden_def (preadv)
 #endif
diff --git a/sysdeps/unix/sysv/linux/preadv64v2.c b/sysdeps/unix/sysv/linux/preadv64v2.c
new file mode 100644
index 0000000..64afb05
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/preadv64v2.c
@@ -0,0 +1,51 @@ 
+/* Linux implementation of preadv2 (LFS version).
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sys/uio.h>
+#include <sysdep-cancel.h>
+
+#if !defined(__NR_preadv64v2) && defined(__NR_preadv2)
+# define __NR_preadv64v2 __NR_preadv2
+#endif
+
+ssize_t
+preadv64v2 (int fd, const struct iovec *vector, int count, off64_t offset,
+	    int flags)
+{
+#ifdef __NR_preadv64v2
+  ssize_t result = SYSCALL_CANCEL (preadv64v2, fd, vector, count,
+				   LO_HI_LONG (offset), flags);
+  if (result >= 0 || errno != ENOSYS)
+    return result;
+#endif
+  /* Trying to emulate the preadv2 syscall flags is troublesome:
+
+     * We can not temporary change the file state of the O_DSYNC and O_SYNC
+       flags to emulate RWF_{D}SYNC (attempts to change the state of using
+       fcntl silently ignored).
+
+     * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
+       semantic not provided by any other flag (O_NONBLOCK for instance).
+
+     So for generic case just ignore the flags can call preadv directly.  */
+  return preadv64 (fd, vector, count, offset);
+}
+
+#ifdef __OFF_T_MATCHES_OFF64_T
+strong_alias (preadv64v2, preadv2)
+#endif
diff --git a/sysdeps/unix/sysv/linux/pwrite64.c b/sysdeps/unix/sysv/linux/pwrite64.c
index 57e5d20..71959c0 100644
--- a/sysdeps/unix/sysv/linux/pwrite64.c
+++ b/sysdeps/unix/sysv/linux/pwrite64.c
@@ -28,6 +28,7 @@  __libc_pwrite64 (int fd, const void *buf, size_t count, off64_t offset)
 {
   return SYSCALL_CANCEL (pwrite64, fd, buf, count, SYSCALL_LL64_PRW (offset));
 }
+
 weak_alias (__libc_pwrite64, __pwrite64)
 libc_hidden_weak (__pwrite64)
 weak_alias (__libc_pwrite64, pwrite64)
diff --git a/sysdeps/unix/sysv/linux/pwritev.c b/sysdeps/unix/sysv/linux/pwritev.c
index 2789943..c91c248 100644
--- a/sysdeps/unix/sysv/linux/pwritev.c
+++ b/sysdeps/unix/sysv/linux/pwritev.c
@@ -50,4 +50,6 @@  pwritev (int fd, const struct iovec *vector, int count, off_t offset)
 #  define OFF_T off_t
 #  include <sysdeps/posix/pwritev.c>
 # endif /* __ASSUME_PREADV  */
+
+libc_hidden_def (pwritev)
 #endif
diff --git a/sysdeps/unix/sysv/linux/pwritev2.c b/sysdeps/unix/sysv/linux/pwritev2.c
new file mode 100644
index 0000000..176c038
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/pwritev2.c
@@ -0,0 +1,47 @@ 
+/* Linux implementation of pwritev2.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sys/uio.h>
+#include <sysdep-cancel.h>
+
+#ifndef __OFF_T_MATCHES_OFF64_T
+
+ssize_t
+pwritev2 (int fd, const struct iovec *vector, int count, off_t offset,
+	  int flags)
+{
+# ifdef __NR_pwritev2
+  ssize_t result = SYSCALL_CANCEL (pwritev2, fd, vector, count,
+				   LO_HI_LONG (offset), flags);
+  if (result >= 0 || errno != ENOSYS)
+    return result;
+# endif
+  /* Trying to emulate the pwritev2 syscall flags is troublesome:
+
+     * We can not temporary change the file state of the O_DSYNC and O_SYNC
+       flags to emulate RWF_{D}SYNC (attempts to change the state of using
+       fcntl silently ignored).
+
+     * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
+       semantic not provided by any other flag (O_NONBLOCK for instance).
+
+     So for generic case just ignore the flags can call pwritev directly.  */
+  return pwritev (fd, vector, count, offset);
+}
+
+#endif
diff --git a/sysdeps/unix/sysv/linux/pwritev64.c b/sysdeps/unix/sysv/linux/pwritev64.c
index 1e3a36c..b236df3 100644
--- a/sysdeps/unix/sysv/linux/pwritev64.c
+++ b/sysdeps/unix/sysv/linux/pwritev64.c
@@ -48,7 +48,9 @@  pwritev64 (int fd, const struct iovec *vector, int count, off64_t offset)
 # define OFF_T off64_t
 # include <sysdeps/posix/pwritev.c>
 #endif
+libc_hidden_def (pwritev64)
 
 #ifdef __OFF_T_MATCHES_OFF64_T
 strong_alias (pwritev64, pwritev)
+libc_hidden_def (pwritev)
 #endif
diff --git a/sysdeps/unix/sysv/linux/pwritev64v2.c b/sysdeps/unix/sysv/linux/pwritev64v2.c
new file mode 100644
index 0000000..01d0c89
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/pwritev64v2.c
@@ -0,0 +1,51 @@ 
+/* Linux implementation of pwritev2 (LFS version).
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sys/uio.h>
+#include <sysdep-cancel.h>
+
+#if !defined(__NR_pwritev64v2) && defined(__NR_pwritev2)
+# define __NR_pwritev64v2 __NR_pwritev2
+#endif
+
+ssize_t
+pwritev64v2 (int fd, const struct iovec *vector, int count, off64_t offset,
+	     int flags)
+{
+#ifdef __NR_pwritev64v2
+  ssize_t result = SYSCALL_CANCEL (pwritev64v2, fd, vector, count,
+				   LO_HI_LONG (offset), flags);
+  if (result >= 0 || errno != ENOSYS)
+    return result;
+#endif
+  /* Trying to emulate the pwritev2 syscall flags is troublesome:
+
+     * We can not temporary change the file state of the O_DSYNC and O_SYNC
+       flags to emulate RWF_{D}SYNC (attempts to change the state of using
+       fcntl silently ignored).
+
+     * IOCB_HIPRI requires the file opened in O_DIRECT and uses an internal
+       semantic not provided by any other flag (O_NONBLOCK for instance).
+
+     So for generic case just ignore the flags can call pwritev directly.  */
+  return pwritev64 (fd, vector, count, offset);
+}
+
+#ifdef __OFF_T_MATCHES_OFF64_T
+strong_alias (pwritev64v2, pwritev2)
+#endif
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
index ed1b6bf..eb9e72f 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
@@ -1980,6 +1980,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
index 2e75d29..1402959 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
@@ -1881,6 +1881,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/sh/libc.abilist b/sysdeps/unix/sysv/linux/sh/libc.abilist
index bd74c0c..e9eefcb 100644
--- a/sysdeps/unix/sysv/linux/sh/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/libc.abilist
@@ -1866,6 +1866,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
index 5584838..967699e 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
@@ -1972,6 +1972,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
index efedbe2..9dd938a 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
@@ -1910,6 +1910,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
index ffd988a..68c9887 100644
--- a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist
@@ -2104,3 +2104,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
diff --git a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
index f0c13ce..97aa0f7 100644
--- a/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist
@@ -2104,3 +2104,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
diff --git a/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist b/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
index ffd988a..68c9887 100644
--- a/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
+++ b/sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist
@@ -2104,3 +2104,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
diff --git a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
index f57004c..2032659 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
@@ -1861,6 +1861,11 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F
 GLIBC_2.3 GLIBC_2.3 A
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
index 05629e1..11a278c 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
@@ -2104,3 +2104,8 @@  GLIBC_2.25 getrandom F
 GLIBC_2.25 strfromd F
 GLIBC_2.25 strfromf F
 GLIBC_2.25 strfroml F
+GLIBC_2.26 GLIBC_2.26 A
+GLIBC_2.26 preadv2 F
+GLIBC_2.26 preadv64v2 F
+GLIBC_2.26 pwritev2 F
+GLIBC_2.26 pwritev64v2 F