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, 42 insertions, 0 deletions

diff --git a/c_src/include/linux/key.h b/c_src/include/linux/key.h
new file mode 100644
index 00000000..cc6859a9
--- /dev/null
+++ b/c_src/include/linux/key.h
@@ -0,0 +1,42 @@
+#ifndef _LINUX_KEY_H
+#define _LINUX_KEY_H
+
+#include <linux/types.h>
+#include <linux/atomic.h>
+#include <keyutils.h>
+
+struct user_key_payload {
+	size_t		datalen;	/* length of this data */
+	char		data[0];	/* actual data */
+};
+
+struct key {
+	atomic_t		usage;		/* number of references */
+	key_serial_t		serial;		/* key serial number */
+	struct rw_semaphore	sem;		/* change vs change sem */
+	struct user_key_payload	payload;
+};
+
+static inline const struct user_key_payload *user_key_payload(const struct key *key)
+{
+	return &key->payload;
+}
+
+static inline void key_put(struct key *key)
+{
+	if (atomic_dec_and_test(&key->usage))
+		free(key);
+}
+
+static inline struct key *__key_get(struct key *key)
+{
+	atomic_inc(&key->usage);
+	return key;
+}
+
+static inline struct key *key_get(struct key *key)
+{
+	return key ? __key_get(key) : key;
+}
+
+#endif /* _LINUX_KEY_H */