convert main() from C to Rust

This moves the main() function from C to Rust. It also updates the name
of the Rust package from "bcachefs-rust" to "bcachefs-tools".

Signed-off-by: Thomas Bertschinger <tahbertschinger@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

.github/workflows/build-packages.yml

@@ -79,7 +79,7 @@ jobs:
       - name: Extract MSRV
         run: |
           MSRV=$(cargo metadata --format-version 1 --no-deps --manifest-path rust-src/Cargo.toml |
-                  jq -r '.packages[] | select(.name == "bcachefs-rust") | .rust_version')
+                  jq -r '.packages[] | select(.name == "bcachefs-tools") | .rust_version')
           echo "MSRV=$MSRV" >> $GITHUB_ENV
       - name: Install Rust ${{ env.MSRV }} toolchain
         run: |

Makefile

@@ -77,6 +77,7 @@ PKGCONFIG_LIBS="blkid uuid liburcu libsodium zlib liblz4 libzstd libudev libkeyu
 ifdef BCACHEFS_FUSE
 	PKGCONFIG_LIBS+="fuse3 >= 3.7"
 	CFLAGS+=-DBCACHEFS_FUSE
+	export RUSTFLAGS=--cfg fuse
 endif
 
 PKGCONFIG_CFLAGS:=$(shell $(PKG_CONFIG) --cflags $(PKGCONFIG_LIBS))
@@ -172,25 +173,15 @@ OBJS:=$(SRCS:.c=.o)
 	$(Q)$(CC) $(CPPFLAGS) $(CFLAGS) -c -o $@ $<
 
 BCACHEFS_DEPS=libbcachefs.a
+RUST_SRCS:=$(shell find rust-src/src rust-src/bch_bindgen/src -type f -iname '*.rs')
 
-ifndef NO_RUST
-	BCACHEFS_DEPS+=rust-src/target/release/libbcachefs_rust.a
-else
-	CFLAGS+=-DBCACHEFS_NO_RUST
-endif
-
-bcachefs: $(BCACHEFS_DEPS)
-	@echo "    [LD]     $@"
-	$(Q)$(CC) $(LDFLAGS) -Wl,--whole-archive $+ $(LOADLIBES) -Wl,--no-whole-archive $(LDLIBS) -o $@
+bcachefs: $(BCACHEFS_DEPS) $(RUST_SRCS)
+	$(CARGO_BUILD)
 
 libbcachefs.a: $(filter-out ./tests/%.o, $(OBJS))
 	@echo "    [AR]     $@"
 	$(Q)ar -rc $@ $+
 
-RUST_SRCS:=$(shell find rust-src/src rust-src/bch_bindgen/src -type f -iname '*.rs')
-rust-src/target/release/libbcachefs_rust.a: $(RUST_SRCS)
-	$(CARGO_BUILD)
-
 tests/test_helper: $(filter ./tests/%.o, $(OBJS))
 	@echo "    [LD]     $@"
 	$(Q)$(CC) $(LDFLAGS) $+ $(LOADLIBES) $(LDLIBS) -o $@
@@ -210,7 +201,7 @@ cmd_version.o : .version
 install: INITRAMFS_HOOK=$(INITRAMFS_DIR)/hooks/bcachefs
 install: INITRAMFS_SCRIPT=$(INITRAMFS_DIR)/scripts/local-premount/bcachefs
 install: bcachefs $(optional_install)
-	$(INSTALL) -m0755 -D bcachefs      -t $(DESTDIR)$(ROOT_SBINDIR)
+	$(INSTALL) -m0755 -D rust-src/target/release/bcachefs -t $(DESTDIR)$(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)
@@ -233,7 +224,7 @@ install_systemd: $(systemd_services) $(systemd_libexecfiles)
 .PHONY: clean
 clean:
 	@echo "Cleaning all"
-	$(Q)$(RM) bcachefs libbcachefs.a tests/test_helper .version *.tar.xz $(OBJS) $(DEPS) $(DOCGENERATED)
+	$(Q)$(RM) libbcachefs.a tests/test_helper .version *.tar.xz $(OBJS) $(DEPS) $(DOCGENERATED)
 	$(Q)$(CARGO_CLEAN)
 	$(Q)$(RM) -f $(built_scripts)
 

bcachefs.c

@@ -25,7 +25,7 @@
 
 #include "cmds.h"
 
-static void usage(void)
+void bcachefs_usage(void)
 {
 	puts("bcachefs - tool for managing bcachefs filesystems\n"
 	     "usage: bcachefs <command> [<args>]\n"
@@ -36,11 +36,9 @@ static void usage(void)
 	     "  set-option               Set a filesystem option\n"
 	     "  reset-counters           Reset all counters on an unmounted device\n"
 	     "\n"
-#ifndef BCACHEFS_NO_RUST
 	     "Mount:\n"
 	     "  mount                    Mount a filesystem\n"
 	     "\n"
-#endif
 	     "Repair:\n"
 	     "  fsck                     Check an existing filesystem for errors\n"
 	     "\n"
@@ -89,18 +87,14 @@ static void usage(void)
 	     "Debug:\n"
 	     "These commands work on offline, unmounted filesystems\n"
 	     "  dump                     Dump filesystem metadata to a qcow2 image\n"
-#ifndef BCACHEFS_NO_RUST
 	     "  list                     List filesystem metadata in textual form\n"
-#endif
 	     "  list_journal             List contents of journal\n"
 	     "\n"
 	     "FUSE:\n"
 	     "  fusemount                Mount a filesystem via FUSE\n"
 	     "\n"
 	     "Miscellaneous:\n"
-#ifndef BCACHEFS_NO_RUST
          "  completions              Generate shell completions\n"
-#endif
 	     "  version                  Display the version of the invoked bcachefs tool\n");
 }
 
@@ -115,12 +109,12 @@ static char *pop_cmd(int *argc, char *argv[])
 	return cmd;
 }
 
-static int fs_cmds(int argc, char *argv[])
+int fs_cmds(int argc, char *argv[])
 {
 	char *cmd = pop_cmd(&argc, argv);
 
 	if (argc < 1) {
-		usage();
+		bcachefs_usage();
 		exit(EXIT_FAILURE);
 	}
 	if (!strcmp(cmd, "usage"))
@@ -129,7 +123,7 @@ static int fs_cmds(int argc, char *argv[])
 	return 0;
 }
 
-static int device_cmds(int argc, char *argv[])
+int device_cmds(int argc, char *argv[])
 {
 	char *cmd = pop_cmd(&argc, argv);
 
@@ -155,7 +149,7 @@ static int device_cmds(int argc, char *argv[])
 	return 0;
 }
 
-static int data_cmds(int argc, char *argv[])
+int data_cmds(int argc, char *argv[])
 {
 	char *cmd = pop_cmd(&argc, argv);
 
@@ -169,7 +163,7 @@ static int data_cmds(int argc, char *argv[])
 	return 0;
 }
 
-static int subvolume_cmds(int argc, char *argv[])
+int subvolume_cmds(int argc, char *argv[])
 {
 	char *cmd = pop_cmd(&argc, argv);
 	if (argc < 1)
@@ -183,112 +177,3 @@ static int subvolume_cmds(int argc, char *argv[])
 
 	return 0;
 }
-
-int main(int argc, char *argv[])
-{
-	raid_init();
-
-	char *full_cmd = argv[0];
-
-	/* Are we being called via a symlink? */
-
-	if (strstr(full_cmd, "mkfs"))
-		return cmd_format(argc, argv);
-
-	if (strstr(full_cmd, "fsck"))
-		return cmd_fsck(argc, argv);
-
-#ifdef BCACHEFS_FUSE
-	if (strstr(full_cmd, "mount.fuse"))
-		return cmd_fusemount(argc, argv);
-#endif
-
-#ifndef BCACHEFS_NO_RUST
-	if (strstr(full_cmd, "mount"))
-		return rust_main(argc, argv, "mount");
-#endif
-
-	setvbuf(stdout, NULL, _IOLBF, 0);
-
-	char *cmd = pop_cmd(&argc, argv);
-	if (!cmd) {
-		puts("missing command\n");
-		goto usage;
-	}
-
-	/* these subcommands display usage when argc < 2 */
-	if (!strcmp(cmd, "device"))
-		return device_cmds(argc, argv);
-	if (!strcmp(cmd, "fs"))
-		return fs_cmds(argc, argv);
-	if (!strcmp(cmd, "data"))
-		return data_cmds(argc, argv);
-	if (!strcmp(cmd, "subvolume"))
-		return subvolume_cmds(argc, argv);
-	if (!strcmp(cmd, "format"))
-		return cmd_format(argc, argv);
-	if (!strcmp(cmd, "fsck"))
-		return cmd_fsck(argc, argv);
-	if (!strcmp(cmd, "version"))
-		return cmd_version(argc, argv);
-	if (!strcmp(cmd, "show-super"))
-		return cmd_show_super(argc, argv);
-	if (!strcmp(cmd, "set-option"))
-		return cmd_set_option(argc, argv);
-	if (!strcmp(cmd, "reset-counters"))
-		return cmd_reset_counters(argc, argv);
-
-#if 0
-	if (!strcmp(cmd, "assemble"))
-		return cmd_assemble(argc, argv);
-	if (!strcmp(cmd, "incremental"))
-		return cmd_incremental(argc, argv);
-	if (!strcmp(cmd, "run"))
-		return cmd_run(argc, argv);
-	if (!strcmp(cmd, "stop"))
-		return cmd_stop(argc, argv);
-#endif
-
-	if (!strcmp(cmd, "unlock"))
-		return cmd_unlock(argc, argv);
-	if (!strcmp(cmd, "set-passphrase"))
-		return cmd_set_passphrase(argc, argv);
-	if (!strcmp(cmd, "remove-passphrase"))
-		return cmd_remove_passphrase(argc, argv);
-
-	if (!strcmp(cmd, "migrate"))
-		return cmd_migrate(argc, argv);
-	if (!strcmp(cmd, "migrate-superblock"))
-		return cmd_migrate_superblock(argc, argv);
-
-	if (!strcmp(cmd, "dump"))
-		return cmd_dump(argc, argv);
-	if (!strcmp(cmd, "list_journal"))
-		return cmd_list_journal(argc, argv);
-	if (!strcmp(cmd, "kill_btree_node"))
-		return cmd_kill_btree_node(argc, argv);
-
-	if (!strcmp(cmd, "setattr"))
-		return cmd_setattr(argc, argv);
-#ifndef BCACHEFS_NO_RUST
-	if (!strcmp(cmd, "list") ||
-	    !strcmp(cmd, "mount") ||
-	    !strcmp(cmd, "completions"))
-		return rust_main(argc, argv, cmd);
-#endif
-
-#ifdef BCACHEFS_FUSE
-	if (!strcmp(cmd, "fusemount"))
-		return cmd_fusemount(argc, argv);
-#endif
-
-	if (!strcmp(cmd, "--help")) {
-		usage();
-		return 0;
-	}
-
-	printf("Unknown command %s\n", cmd);
-usage:
-	usage();
-	exit(EXIT_FAILURE);
-}

cmds.h

@@ -54,6 +54,10 @@ int cmd_subvolume_snapshot(int argc, char *argv[]);
 
 int cmd_fusemount(int argc, char *argv[]);
 
-int rust_main(int argc, char *argv[], char *cmd);
+void bcachefs_usage(void);
+int device_cmds(int argc, char *argv[]);
+int fs_cmds(int argc, char *argv[]);
+int data_cmds(int argc, char *argv[]);
+int subvolume_cmds(int argc, char *argv[]);
 
 #endif /* _CMDS_H */

rust-src/Cargo.toml

@@ -1,12 +1,16 @@
 [package]
-name = "bcachefs-rust"
+name = "bcachefs-tools"
 version = "0.3.1"
 authors = ["Yuxuan Shui <yshuiv7@gmail.com>", "Kayla Firestack <dev@kaylafire.me>", "Kent Overstreet <kent.overstreet@linux.dev>" ]
 edition = "2021"
 rust-version = "1.65"
 
+[[bin]]
+name = "bcachefs"
+path = "src/bcachefs.rs"
+
 [lib]
-crate-type = ["staticlib"]
+name = "bcachefs"
 
 [dependencies]
 atty = "0.2.14"

rust-src/bch_bindgen/build.rs

@@ -10,6 +10,8 @@ impl bindgen::callbacks::ParseCallbacks for Fix753 {
 fn main() {
     use std::path::PathBuf;
 
+    println!("cargo:rerun-if-changed=src/libbcachefs_wrapper.h");
+
     let out_dir: PathBuf = std::env::var_os("OUT_DIR")
         .expect("ENV Var 'OUT_DIR' Expected")
         .into();
@@ -44,6 +46,10 @@ fn main() {
         .default_enum_style(bindgen::EnumVariation::Rust {
             non_exhaustive: true,
         })
+        .allowlist_function("bcachefs_usage")
+        .allowlist_function("raid_init")
+        .allowlist_function("cmd_.*")
+        .allowlist_function(".*_cmds")
         .allowlist_function(".*bch2_.*")
         .allowlist_function("bio_.*")
         .allowlist_function("derive_passphrase")

rust-src/bch_bindgen/src/libbcachefs_wrapper.h

@@ -11,6 +11,8 @@
 #include "../crypto.h"
 #include "../include/linux/bio.h"
 #include "../include/linux/blkdev.h"
+#include "../cmds.h"
+#include "../raid/raid.h"
 
 
 #define MARK_FIX_753(req_name) const blk_mode_t Fix753_##req_name = req_name;

rust-src/build.rs

@@ -0,0 +1,21 @@
+fn main() {
+    println!("cargo:rustc-link-search=..");
+    println!("cargo:rerun-if-changed=../libbcachefs.a");
+    println!("cargo:rustc-link-lib=static:+whole-archive=bcachefs");
+
+    println!("cargo:rustc-link-lib=urcu");
+    println!("cargo:rustc-link-lib=zstd");
+    println!("cargo:rustc-link-lib=blkid");
+    println!("cargo:rustc-link-lib=uuid");
+    println!("cargo:rustc-link-lib=sodium");
+    println!("cargo:rustc-link-lib=z");
+    println!("cargo:rustc-link-lib=lz4");
+    println!("cargo:rustc-link-lib=zstd");
+    println!("cargo:rustc-link-lib=udev");
+    println!("cargo:rustc-link-lib=keyutils");
+    println!("cargo:rustc-link-lib=aio");
+
+    if std::env::var("BCACHEFS_FUSE").is_ok() {
+        println!("cargo:rustc-link-lib=fuse3");
+    }
+}