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, 32 insertions, 0 deletions

diff --git a/c_src/include/linux/bsearch.h b/c_src/include/linux/bsearch.h
new file mode 100644
index 00000000..e66b711d
--- /dev/null
+++ b/c_src/include/linux/bsearch.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_BSEARCH_H
+#define _LINUX_BSEARCH_H
+
+#include <linux/types.h>
+
+static __always_inline
+void *__inline_bsearch(const void *key, const void *base, size_t num, size_t size, cmp_func_t cmp)
+{
+	const char *pivot;
+	int result;
+
+	while (num > 0) {
+		pivot = base + (num >> 1) * size;
+		result = cmp(key, pivot);
+
+		if (result == 0)
+			return (void *)pivot;
+
+		if (result > 0) {
+			base = pivot + size;
+			num--;
+		}
+		num >>= 1;
+	}
+
+	return NULL;
+}
+
+extern void *bsearch(const void *key, const void *base, size_t num, size_t size, cmp_func_t cmp);
+
+#endif /* _LINUX_BSEARCH_H */