1 files changed, 55 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/preadv2.c b/sysdeps/unix/sysv/linux/preadv2.c
new file mode 100644
index 0000000000..11fe85eaa8
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/preadv2.c
@@ -0,0 +1,55 @@
+/* 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 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).  */
+
+  if (flags != 0)
+    {
+      __set_errno (EOPNOTSUPP);
+      return -1;
+    }
+  return preadv (fd, vector, count, offset);
+}
+
+#endif