Rust now integrated into bcachefs binary

Rust is now required for building the bcachefs tool, and rust code is
now fully integrated with the C codebase - meaning it is possible to
call back and forth.

The mount helper is now a subcommand, 'mount.bcachefs' is now a small
shell wrapper that invokes 'bcachefs mount'.

This will make it easier to start rewriting other subcommands in rust,
and eventually the whole command line interface.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

13 files changed, 116 insertions, 139 deletions

diff --git a/rust-src/mount/.gitignore b/rust-src/.gitignore
index 644cd426..644cd426 100644
--- a/rust-src/mount/.gitignore
+++ b/rust-src/.gitignore
diff --git a/rust-src/mount/Cargo.lock b/rust-src/Cargo.lock
index 0b193360..9e5fd2a5 100644
--- a/rust-src/mount/Cargo.lock
+++ b/rust-src/Cargo.lock
@@ -44,7 +44,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
 
 [[package]]
-name = "bcachefs-mount"
+name = "bcachefs-rust"
 version = "0.3.1"
 dependencies = [
  "anyhow",
diff --git a/rust-src/mount/Cargo.toml b/rust-src/Cargo.toml
index 40113945..64b195ca 100644
--- a/rust-src/mount/Cargo.toml
+++ b/rust-src/Cargo.toml
@@ -1,10 +1,11 @@
 [package]
-name = "bcachefs-mount"
+name = "bcachefs-rust"
 version = "0.3.1"
 authors = ["Yuxuan Shui <yshuiv7@gmail.com>", "Kayla Firestack <dev@kaylafire.me>"]
 edition = "2018"
 
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+[lib]
+crate-type = ["staticlib"]
 
 [dependencies]
 atty = "0.2.14"
@@ -23,5 +24,5 @@ parse-display = "0.1"
 errno = "0.2"
 either = "1.5"
 rpassword = "4"
-bch_bindgen = { path = "../bch_bindgen" }
+bch_bindgen = { path = "bch_bindgen" }
 byteorder = "1.3"
diff --git a/rust-src/mount/README.md b/rust-src/README.md
index e4700f6b..e4700f6b 100644
--- a/rust-src/mount/README.md
+++ b/rust-src/README.md
diff --git a/rust-src/bch_bindgen/build.rs b/rust-src/bch_bindgen/build.rs
index da1541b1..a2cb8957 100644
--- a/rust-src/bch_bindgen/build.rs
+++ b/rust-src/bch_bindgen/build.rs
@@ -7,13 +7,8 @@ fn main() {
     let top_dir: PathBuf = std::env::var_os("CARGO_MANIFEST_DIR")
         .expect("ENV Var 'CARGO_MANIFEST_DIR' Expected")
         .into();
-    let libbcachefs_inc_dir = std::env::var("LIBBCACHEFS_INCLUDE")
-        .unwrap_or_else(|_| top_dir.join("libbcachefs").display().to_string());
-    let libbcachefs_inc_dir = std::path::Path::new(&libbcachefs_inc_dir);
-    println!("{}", libbcachefs_inc_dir.display());
 
-    println!("cargo:rustc-link-lib=dylib=bcachefs");
-    println!("cargo:rustc-link-search={}", env!("LIBBCACHEFS_LIB"));
+    let libbcachefs_inc_dir = std::path::Path::new("../..");
 
     let _libbcachefs_dir = top_dir.join("libbcachefs").join("libbcachefs");
     let bindings = bindgen::builder()
diff --git a/rust-src/mount/default.nix b/rust-src/default.nix
index 7cc4b956..7cc4b956 100644
--- a/rust-src/mount/default.nix
+++ b/rust-src/default.nix
diff --git a/rust-src/mount/module.nix b/rust-src/module.nix
index b62aa7dc..b62aa7dc 100644
--- a/rust-src/mount/module.nix
+++ b/rust-src/module.nix
diff --git a/rust-src/mount/src/main.rs b/rust-src/mount/src/main.rs
deleted file mode 100644
index 66ec8acc..00000000
--- a/rust-src/mount/src/main.rs
+++ /dev/null
@@ -1,53 +0,0 @@
-use bcachefs_mount::Cli;
-use bch_bindgen::{error, info};
-use clap::Parser;
-use colored::Colorize;
-
-fn main() {
-    let opt = Cli::parse();
-    bch_bindgen::log::set_verbose_level(opt.verbose + bch_bindgen::log::ERROR);
-    colored::control::set_override(opt.colorize);
-    if let Err(e) = crate::main_inner(opt) {
-        error!("Fatal error: {}", e);
-    }
-}
-
-pub fn main_inner(opt: Cli) -> anyhow::Result<()> {
-    use bcachefs_mount::{filesystem, key};
-    unsafe {
-        libc::setvbuf(filesystem::stdout, std::ptr::null_mut(), libc::_IONBF, 0);
-        // libc::fflush(filesystem::stdout);
-    }
-
-    let fss = filesystem::probe_filesystems()?;
-    let fs = fss
-        .get(&opt.uuid)
-        .ok_or_else(|| anyhow::anyhow!("filesystem was not found"))?;
-
-    info!("found filesystem {}", fs);
-    if fs.encrypted() {
-        let key = opt
-            .key_location
-            .0
-            .ok_or_else(|| anyhow::anyhow!("no keyoption specified for locked filesystem"))?;
-
-        key::prepare_key(&fs, key)?;
-    }
-
-    let mountpoint = opt
-        .mountpoint
-        .ok_or_else(|| anyhow::anyhow!("mountpoint option was not specified"))?;
-
-    fs.mount(&mountpoint, &opt.options)?;
-
-    Ok(())
-}
-
-#[cfg(test)]
-mod test {
-    // use insta::assert_debug_snapshot;
-    // #[test]
-    // fn snapshot_testing() {
-    //  insta::assert_debug_snapshot!();
-    // }
-}
diff --git a/rust-src/mount/rustfmt.toml b/rust-src/rustfmt.toml
index 42f2ad7c..42f2ad7c 100644
--- a/rust-src/mount/rustfmt.toml
+++ b/rust-src/rustfmt.toml
diff --git a/rust-src/mount/src/lib.rs b/rust-src/src/cmd_mount.rs
index 68acde03..7748b199 100644
--- a/rust-src/mount/src/lib.rs
+++ b/rust-src/src/cmd_mount.rs
@@ -1,66 +1,11 @@
-use anyhow::anyhow;
-use atty::Stream;
+use bch_bindgen::{error, info};
 use clap::Parser;
+use colored::Colorize;
+use atty::Stream;
 use uuid::Uuid;
-
-pub mod err {
-    pub enum GError {
-        Unknown {
-            message: std::borrow::Cow<'static, String>,
-        },
-    }
-    pub type GResult<T, E, OE> = ::core::result::Result<::core::result::Result<T, E>, OE>;
-    pub type Result<T, E> = GResult<T, E, GError>;
-}
-
-#[macro_export]
-macro_rules! c_str {
-    ($lit:expr) => {
-        unsafe {
-            std::ffi::CStr::from_ptr(concat!($lit, "\0").as_ptr() as *const std::os::raw::c_char)
-                .to_bytes_with_nul()
-                .as_ptr() as *const std::os::raw::c_char
-        }
-    };
-}
-
-#[derive(Debug)]
-struct ErrnoError(errno::Errno);
-impl std::fmt::Display for ErrnoError {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
-        self.0.fmt(f)
-    }
-}
-impl std::error::Error for ErrnoError {}
-
-#[derive(Clone, Debug)]
-pub enum KeyLocation {
-    Fail,
-    Wait,
-    Ask,
-}
-
-#[derive(Clone, Debug)]
-pub struct KeyLoc(pub Option<KeyLocation>);
-impl std::ops::Deref for KeyLoc {
-    type Target = Option<KeyLocation>;
-    fn deref(&self) -> &Self::Target {
-        &self.0
-    }
-}
-impl std::str::FromStr for KeyLoc {
-    type Err = anyhow::Error;
-    fn from_str(s: &str) -> anyhow::Result<Self> {
-        // use anyhow::anyhow;
-        match s {
-            "" => Ok(KeyLoc(None)),
-            "fail" => Ok(KeyLoc(Some(KeyLocation::Fail))),
-            "wait" => Ok(KeyLoc(Some(KeyLocation::Wait))),
-            "ask" => Ok(KeyLoc(Some(KeyLocation::Ask))),
-            _ => Err(anyhow!("invalid password option")),
-        }
-    }
-}
+use crate::filesystem;
+use crate::key;
+use crate::key::KeyLoc;
 
 fn parse_fstab_uuid(uuid_raw: &str) -> Result<Uuid, uuid::Error> {
     let mut uuid = String::from(uuid_raw);
@@ -114,12 +59,41 @@ pub struct Cli {
     pub verbose: u8,
 }
 
-pub mod filesystem;
-pub mod key;
-// pub fn mnt_in_use()
+pub fn cmd_mount_inner(opt: Cli) -> anyhow::Result<()> {
+    unsafe {
+        libc::setvbuf(filesystem::stdout, std::ptr::null_mut(), libc::_IONBF, 0);
+    }
 
-#[test]
-fn verify_cli() {
-    use clap::CommandFactory;
-    Cli::command().debug_assert()
+    let fss = filesystem::probe_filesystems()?;
+    let fs = fss
+        .get(&opt.uuid)
+        .ok_or_else(|| anyhow::anyhow!("filesystem was not found"))?;
+
+    info!("found filesystem {}", fs);
+    if fs.encrypted() {
+        let key = opt
+            .key_location
+            .0
+            .ok_or_else(|| anyhow::anyhow!("no keyoption specified for locked filesystem"))?;
+
+        key::prepare_key(&fs, key)?;
+    }
+
+    let mountpoint = opt
+        .mountpoint
+        .ok_or_else(|| anyhow::anyhow!("mountpoint option was not specified"))?;
+
+    fs.mount(&mountpoint, &opt.options)?;
+
+    Ok(())
+}
+
+#[no_mangle]
+pub extern "C" fn cmd_mount() {
+    let opt = Cli::parse();
+    bch_bindgen::log::set_verbose_level(opt.verbose + bch_bindgen::log::ERROR);
+    colored::control::set_override(opt.colorize);
+    if let Err(e) = cmd_mount_inner(opt) {
+        error!("Fatal error: {}", e);
+    }
 }
diff --git a/rust-src/mount/src/filesystem.rs b/rust-src/src/filesystem.rs
index 28a2ab9e..28a2ab9e 100644
--- a/rust-src/mount/src/filesystem.rs
+++ b/rust-src/src/filesystem.rs
diff --git a/rust-src/mount/src/key.rs b/rust-src/src/key.rs
index a49baa68..e2d0e4c0 100644
--- a/rust-src/mount/src/key.rs
+++ b/rust-src/src/key.rs
@@ -1,5 +1,36 @@
 use bch_bindgen::info;
 use colored::Colorize;
+use crate::c_str;
+use anyhow::anyhow;
+
+#[derive(Clone, Debug)]
+pub enum KeyLocation {
+    Fail,
+    Wait,
+    Ask,
+}
+
+#[derive(Clone, Debug)]
+pub struct KeyLoc(pub Option<KeyLocation>);
+impl std::ops::Deref for KeyLoc {
+    type Target = Option<KeyLocation>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl std::str::FromStr for KeyLoc {
+    type Err = anyhow::Error;
+    fn from_str(s: &str) -> anyhow::Result<Self> {
+        match s {
+            "" => Ok(KeyLoc(None)),
+            "fail" => Ok(KeyLoc(Some(KeyLocation::Fail))),
+            "wait" => Ok(KeyLoc(Some(KeyLocation::Wait))),
+            "ask" => Ok(KeyLoc(Some(KeyLocation::Ask))),
+            _ => Err(anyhow!("invalid password option")),
+        }
+    }
+}
 
 fn check_for_key(key_name: &std::ffi::CStr) -> anyhow::Result<bool> {
     use bch_bindgen::keyutils::{self, keyctl_search};
@@ -31,7 +62,6 @@ fn wait_for_key(uuid: &uuid::Uuid) -> anyhow::Result<()> {
 const BCH_KEY_MAGIC: &str = "bch**key";
 use crate::filesystem::FileSystem;
 fn ask_for_key(fs: &FileSystem) -> anyhow::Result<()> {
-    use anyhow::anyhow;
     use bch_bindgen::bcachefs::{self, bch2_chacha_encrypt_key, bch_encrypted_key, bch_key};
     use byteorder::{LittleEndian, ReadBytesExt};
     use std::os::raw::c_char;
@@ -84,14 +114,11 @@ fn ask_for_key(fs: &FileSystem) -> anyhow::Result<()> {
     }
 }
 
-pub fn prepare_key(fs: &FileSystem, password: crate::KeyLocation) -> anyhow::Result<()> {
-    use crate::KeyLocation::*;
-    use anyhow::anyhow;
-
+pub fn prepare_key(fs: &FileSystem, password: KeyLocation) -> anyhow::Result<()> {
     info!("checking if key exists for filesystem {}", fs.uuid());
     match password {
-        Fail => Err(anyhow!("no key available")),
-        Wait => Ok(wait_for_key(fs.uuid())?),
-        Ask => ask_for_key(fs),
+        KeyLocation::Fail => Err(anyhow!("no key available")),
+        KeyLocation::Wait => Ok(wait_for_key(fs.uuid())?),
+        KeyLocation::Ask => ask_for_key(fs),
     }
 }
diff --git a/rust-src/src/lib.rs b/rust-src/src/lib.rs
new file mode 100644
index 00000000..b2f0aaa7
--- /dev/null
+++ b/rust-src/src/lib.rs
@@ -0,0 +1,33 @@
+pub mod filesystem;
+pub mod key;
+pub mod cmd_mount;
+
+pub mod err {
+    pub enum GError {
+        Unknown {
+            message: std::borrow::Cow<'static, String>,
+        },
+    }
+    pub type GResult<T, E, OE> = ::core::result::Result<::core::result::Result<T, E>, OE>;
+    pub type Result<T, E> = GResult<T, E, GError>;
+}
+
+#[macro_export]
+macro_rules! c_str {
+    ($lit:expr) => {
+        unsafe {
+            std::ffi::CStr::from_ptr(concat!($lit, "\0").as_ptr() as *const std::os::raw::c_char)
+                .to_bytes_with_nul()
+                .as_ptr() as *const std::os::raw::c_char
+        }
+    };
+}
+
+#[derive(Debug)]
+struct ErrnoError(errno::Errno);
+impl std::fmt::Display for ErrnoError {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> Result<(), std::fmt::Error> {
+        self.0.fmt(f)
+    }
+}
+impl std::error::Error for ErrnoError {}