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, 12 insertions, 0 deletions

diff --git a/c_src/include/linux/dcache.h b/c_src/include/linux/dcache.h
new file mode 100644
index 00000000..7637854d
--- /dev/null
+++ b/c_src/include/linux/dcache.h
@@ -0,0 +1,12 @@
+#ifndef __LINUX_DCACHE_H
+#define __LINUX_DCACHE_H
+
+struct super_block;
+struct inode;
+
+struct dentry {
+	struct super_block *d_sb;
+	struct inode *d_inode;
+};
+
+#endif	/* __LINUX_DCACHE_H */