move Rust sources to top level, C sources into c_src

This moves the Rust sources out of rust_src/ and into the top level.
Running the bcachefs executable out of the development tree is now:

$ ./target/release/bcachefs command
or
$ cargo run --profile release -- command

instead of "./bcachefs command".

Building and installing is still:

$ make && make install

Signed-off-by: Thomas Bertschinger <tahbertschinger@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

1 files changed, 33 insertions, 0 deletions

diff --git a/c_src/include/linux/prandom.h b/c_src/include/linux/prandom.h
new file mode 100644
index 00000000..9aea22dc
--- /dev/null
+++ b/c_src/include/linux/prandom.h
@@ -0,0 +1,33 @@
+#ifndef _LINUX_PRANDOM_H
+#define _LINUX_PRANDOM_H
+
+#include <linux/random.h>
+
+static inline void prandom_bytes(void *buf, int nbytes)
+{
+	return get_random_bytes(buf, nbytes);
+}
+
+#define prandom_type(type)				\
+static inline type prandom_##type(void)			\
+{							\
+	type v;						\
+							\
+	prandom_bytes(&v, sizeof(v));			\
+	return v;					\
+}
+
+prandom_type(int);
+prandom_type(long);
+prandom_type(u32);
+prandom_type(u64);
+#undef prandom_type
+
+static inline u32 prandom_u32_max(u32 max)
+{
+	return prandom_u32() % max;
+
+}
+
+#endif /* _LINUX_PRANDOM_H */
+