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>

18 files changed, 151 insertions, 173 deletions

diff --git a/.gitignore b/.gitignore
index 7ba6add8..15accd00 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,8 +6,6 @@ bcachefs.5
 *.so
 *.d
 *.a
-/rust-src/mount/result
-/rust-src/bch_bindgen/result
 tags
 TAGS
 cscope*
@@ -21,6 +19,4 @@ tests/__pycache__/
 !.travis.yml
 !.editorconfig
 
-mount/target
-mount.bcachefs
 bcachefs-principles-of-operation.*
diff --git a/Makefile b/Makefile
index bce10d5b..8846e127 100644
--- a/Makefile
+++ b/Makefile
@@ -90,10 +90,11 @@ else
 endif
 
 .PHONY: all
-all: bcachefs lib
+all: bcachefs
 
-.PHONY: lib
-lib: libbcachefs.so
+.PHONY: debug
+debug: CFLAGS+=-Werror -DCONFIG_BCACHEFS_DEBUG=y -DCONFIG_VALGRIND=y
+debug: bcachefs
 
 .PHONY: tests
 tests: tests/test_helper
@@ -123,30 +124,17 @@ OBJS=$(SRCS:.c=.o)
 	@echo "    [CC]     $@"
 	$(Q)$(CC) $(CPPFLAGS) $(CFLAGS) -c -o $@ $<
 
-bcachefs: $(filter-out ./tests/%.o, $(OBJS))
+bcachefs: libbcachefs.a rust-src/target/release/libbcachefs_rust.a
 	@echo "    [LD]     $@"
-	$(Q)$(CC) $(LDFLAGS) $+ $(LOADLIBES) $(LDLIBS) -o $@
-
-RUST_SRCS=$(shell find rust-src/ -type f -iname '*.rs')
-MOUNT_SRCS=$(filter %mount, $(RUST_SRCS))
-
-debug: CFLAGS+=-Werror -DCONFIG_BCACHEFS_DEBUG=y -DCONFIG_VALGRIND=y
-debug: bcachefs
-
-MOUNT_OBJ=$(filter-out ./bcachefs.o ./tests/%.o ./cmd_%.o , $(OBJS))
-libbcachefs.so: LDFLAGS+=-shared
-libbcachefs.so: $(MOUNT_OBJ)
-	@echo "    [CC]     $@"
-	$(Q)$(CC) $(LDFLAGS) $+ -o $@ $(LDLIBS)
-
-MOUNT_TOML=rust-src/mount/Cargo.toml
-mount.bcachefs: lib $(MOUNT_SRCS)
-	LIBBCACHEFS_LIB=$(CURDIR) \
-	LIBBCACHEFS_INCLUDE=$(CURDIR) \
-	$(CARGO_BUILD) --manifest-path $(MOUNT_TOML)
+	$(Q)$(CC) $(LDFLAGS) -Wl,--whole-archive $+ $(LOADLIBES) -Wl,--no-whole-archive $(LDLIBS) -o $@
 
-	ln -f rust-src/mount/target/$(CARGO_PROFILE)/bcachefs-mount $@
+libbcachefs.a: $(filter-out ./tests/%.o, $(OBJS))
+	@echo "    [AR]     $@"
+	$(Q)ar -rc $@ $+
 
+RUST_SRCS=$(shell find rust-src/ -type f -iname '*.rs')
+rust-src/target/release/libbcachefs_rust.a: libbcachefs.a $(RUST_SRCS)
+	$(CARGO_BUILD) --manifest-path rust-src/Cargo.toml
 
 tests/test_helper: $(filter ./tests/%.o, $(OBJS))
 	@echo "    [LD]     $@"
@@ -166,15 +154,14 @@ cmd_version.o : .version
 .PHONY: install
 install: INITRAMFS_HOOK=$(INITRAMFS_DIR)/hooks/bcachefs
 install: INITRAMFS_SCRIPT=$(INITRAMFS_DIR)/scripts/local-premount/bcachefs
-install: bcachefs lib
+install: bcachefs
 	$(INSTALL) -m0755 -D bcachefs      -t $(DESTDIR)$(ROOT_SBINDIR)
 	$(INSTALL) -m0755    fsck.bcachefs    $(DESTDIR)$(ROOT_SBINDIR)
 	$(INSTALL) -m0755    mkfs.bcachefs    $(DESTDIR)$(ROOT_SBINDIR)
+	$(INSTALL) -m0755    mount.bcachefs   $(DESTDIR)$(ROOT_SBINDIR)
 	$(INSTALL) -m0644 -D bcachefs.8    -t $(DESTDIR)$(PREFIX)/share/man/man8/
 	$(INSTALL) -m0755 -D initramfs/script $(DESTDIR)$(INITRAMFS_SCRIPT)
 	$(INSTALL) -m0755 -D initramfs/hook   $(DESTDIR)$(INITRAMFS_HOOK)
-	$(INSTALL) -m0755 -D mount.bcachefs.sh $(DESTDIR)$(ROOT_SBINDIR)
-	$(INSTALL) -m0755 -D libbcachefs.so -t $(DESTDIR)$(PREFIX)/lib/
 
 	sed -i '/^# Note: make install replaces/,$$d' $(DESTDIR)$(INITRAMFS_HOOK)
 	echo "copy_exec $(ROOT_SBINDIR)/bcachefs /sbin/bcachefs" >> $(DESTDIR)$(INITRAMFS_HOOK)
@@ -182,7 +169,7 @@ install: bcachefs lib
 .PHONY: clean
 clean:
 	@echo "Cleaning all"
-	$(Q)$(RM) bcachefs mount.bcachefs libbcachefs.so libbcachefs_mount.a tests/test_helper .version *.tar.xz $(OBJS) $(DEPS) $(DOCGENERATED)
+	$(Q)$(RM) bcachefs libbcachefs.a tests/test_helper .version *.tar.xz $(OBJS) $(DEPS) $(DOCGENERATED)
 	$(Q)$(RM) -rf rust-src/*/target
 
 .PHONY: deb
diff --git a/bcachefs.c b/bcachefs.c
index 31d96287..1876823c 100644
--- a/bcachefs.c
+++ b/bcachefs.c
@@ -177,8 +177,21 @@ int main(int argc, char *argv[])
 
 	setvbuf(stdout, NULL, _IOLBF, 0);
 
-	char *cmd = pop_cmd(&argc, argv);
-	if (argc < 1) {
+	if (argc < 2) {
+		puts("missing command\n");
+		goto usage;
+	}
+
+	/* Rust commands first - rust can't handle us mutating argv */
+	char *cmd = argv[1];
+
+	if (!strcmp(cmd, "mount")) {
+		cmd_mount();
+		return 0;
+	}
+
+	cmd = pop_cmd(&argc, argv);
+	if (!cmd) {
 		puts("missing command\n");
 		goto usage;
 	}
diff --git a/cmds.h b/cmds.h
index c18a87fd..52b6e0bb 100644
--- a/cmds.h
+++ b/cmds.h
@@ -61,5 +61,6 @@ int cmd_subvolume_delete(int argc, char *argv[]);
 int cmd_subvolume_snapshot(int argc, char *argv[]);
 
 int cmd_fusemount(int argc, char *argv[]);
+void cmd_mount(void);
 
 #endif /* _CMDS_H */
diff --git a/mount.bcachefs b/mount.bcachefs
new file mode 100755
index 00000000..59002328
--- /dev/null
+++ b/mount.bcachefs
@@ -0,0 +1,4 @@
+#!/bin/sh
+
+SDIR="$(readlink -f "$0")"
+exec "${SDIR%/*}/bcachefs" mount "$@"
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 {}