libc: add fallocate() and fallocate64()

We add the Linux-specific function fallocate() which allows the user to
directly manipulate allocate space for a file.  fallocate() can operate
in different modes, but the default mode is equivalent to posix_fallocate()
which is specified in POSIX.1.

Recent releases of e2fsprogs 1.42.11 and above expect fallocate64() to be
available.

Signed-off-by: Anthony G. Basile <blueness@gentoo.org>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

1 files changed, 42 insertions, 0 deletions

diff --git a/libc/sysdeps/linux/common/fallocate64.c b/libc/sysdeps/linux/common/fallocate64.c
new file mode 100644
index 000000000..cf75693d6
--- /dev/null
+++ b/libc/sysdeps/linux/common/fallocate64.c
@@ -0,0 +1,42 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * fallocate() for uClibc - based off posix_fallocate() by Erik Andersen
+ * http://www.opengroup.org/onlinepubs/9699919799/functions/posix_fallocate.html
+ *
+ * Copyright (C) 2000-2006 Erik Andersen <andersen@uclibc.org>
+ *
+ * Licensed under the LGPL v2.1 or later, see the file COPYING.LIB in this tarball.
+ */
+
+#include <sys/syscall.h>
+
+#include <fcntl.h>
+#include <bits/kernel-features.h>
+#include <stdint.h>
+
+#if defined __NR_fallocate
+
+# if __WORDSIZE == 64
+/* Can use normal fallocate() */
+# elif __WORDSIZE == 32
+extern __typeof(fallocate64) __libc_fallocate64 attribute_hidden;
+int attribute_hidden __libc_fallocate64(int fd, int mode, __off64_t offset,
+		__off64_t len)
+{
+	int ret;
+	INTERNAL_SYSCALL_DECL(err);
+	ret = (int) (INTERNAL_SYSCALL(fallocate, err, 6, fd, mode,
+		OFF64_HI_LO (offset), OFF64_HI_LO (len)));
+	if (unlikely(INTERNAL_SYSCALL_ERROR_P (ret, err)))
+		return INTERNAL_SYSCALL_ERRNO (ret, err);
+	return 0;
+}
+
+#  if defined __UCLIBC_LINUX_SPECIFIC__ && defined __USE_GNU
+strong_alias(__libc_fallocate64,fallocate64)
+#  endif
+
+# else
+# error your machine is neither 32 bit or 64 bit ... it must be magical
+# endif
+#endif