1 files changed, 71 insertions, 0 deletions
diff --git a/sysdeps/posix/posix_fallocate.c b/sysdeps/posix/posix_fallocate.c
new file mode 100644
index 0000000000..cd0f96113e
--- /dev/null
+++ b/sysdeps/posix/posix_fallocate.c
@@ -0,0 +1,71 @@
+/* Copyright (C) 2000 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 Library General Public License as
+   published by the Free Software Foundation; either version 2 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+
+/* Reserve storage for the data of the file associated with FD.  */
+
+int
+posix_fallocate (int fd, __off_t offset, size_t len)
+{
+  struct stat st;
+  struct statfs f;
+  size_t step;
+
+  /* `off_t� is a signed type.  Therefore we can determine whether
+     OFFSET + LEN is too large if it is a negative value.  */
+  if (offset < 0 || len == 0)
+    return EINVAL;
+  if (offset + len < 0)
+    return EFBIG;
+
+  /* First thing we have to make sure is that this is really a regular
+     file.  */
+  if (__fxstat (_STAT_VER, fd, &st) != 0)
+    return EBADF;
+  if (S_ISFIFO (st.st_mode))
+    return ESPIPE;
+  if (! S_ISREG (st.st_mode))
+    return ENODEV;
+
+  /* We have to know the block size of the filesystem to get at least some
+     sort of performance.  */
+  if (__fstatfs (fd, &f) != 0)
+    return errno;
+
+  /* Align OFFSET to block size and adjust LEN.  */
+  step = (offset + f.f_bsize - 1) % ~f.f_bsize;
+  offset += step;
+
+  /* Write something to every block.  */
+  while (len > step)
+    {
+      len -= step;
+
+      if (pwrite (fd, "", 1, offset) != 1)
+	return errno;
+
+      offset += step;
+    }
+
+  return 0;
+}