libc: add posix_fallocate()

Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

1 files changed, 43 insertions, 0 deletions

diff --git a/libc/sysdeps/linux/common/posix_fallocate.c b/libc/sysdeps/linux/common/posix_fallocate.c
new file mode 100644
index 000000000..9aaa6ce15
--- /dev/null
+++ b/libc/sysdeps/linux/common/posix_fallocate.c
@@ -0,0 +1,43 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * posix_fallocate() for uClibc
+ * 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
+int posix_fallocate(int fd, __off_t offset, __off_t len)
+{
+	int ret;
+
+# if __WORDSIZE == 32
+	uint32_t off_low = offset;
+	uint32_t len_low = len;
+	/* may assert that these >>31 are 0 */
+	uint32_t zero = 0;
+	INTERNAL_SYSCALL_DECL(err);
+	ret = (int) (INTERNAL_SYSCALL(fallocate, err, 6, fd, 0,
+		__LONG_LONG_PAIR (zero, off_low),
+		__LONG_LONG_PAIR (zero, len_low)));
+# elif __WORDSIZE == 64
+	INTERNAL_SYSCALL_DECL(err);
+	ret = (int) (INTERNAL_SYSCALL(fallocate, err, 4, fd, 0, offset, len));
+# else
+# error your machine is neither 32 bit or 64 bit ... it must be magical
+#endif
+    if (unlikely(INTERNAL_SYSCALL_ERROR_P (ret, err)))
+      return INTERNAL_SYSCALL_ERRNO (ret, err);
+    return 0;
+}
+# if defined __UCLIBC_HAS_LFS__ && __WORDSIZE == 64
+strong_alias(posix_fallocate,posix_fallocate64)
+# endif
+#endif