feat: use ExitCode over std::process:exit()

Should provide us with better outputs on process failure, also makes
unwinding better and is generally recommended over `exit()`.

Signed-off-by: Thomas Mühlbacher <tmuehlbacher@posteo.net>

src/bcachefs.rs

@@ -3,7 +3,10 @@ mod key;
 mod logging;
 mod wrappers;
 
-use std::ffi::{c_char, CString};
+use std::{
+    ffi::{c_char, CString},
+    process::{ExitCode, Termination},
+};
 
 use bch_bindgen::c;
 
@@ -71,7 +74,7 @@ fn handle_c_command(mut argv: Vec<String>, symlink_cmd: Option<&str>) -> i32 {
     }
 }
 
-fn main() {
+fn main() -> ExitCode {
     let args: Vec<String> = std::env::args().collect();
 
     let symlink_cmd: Option<&str> = if args[0].contains("mkfs") {
@@ -89,7 +92,7 @@ fn main() {
     if symlink_cmd.is_none() && args.len() < 2 {
         println!("missing command");
         unsafe { c::bcachefs_usage() };
-        std::process::exit(1);
+        return ExitCode::from(1);
     }
 
     unsafe { c::raid_init() };
@@ -99,15 +102,14 @@ fn main() {
         None => args[1].as_str(),
     };
 
-    let ret = match cmd {
-        "completions" => commands::completions(args[1..].to_vec()),
-        "list" => commands::list(args[1..].to_vec()),
-        "mount" => commands::mount(args, symlink_cmd),
-        "subvolume" => commands::subvolume(args[1..].to_vec()),
-        _ => handle_c_command(args, symlink_cmd),
-    };
-
-    if ret != 0 {
-        std::process::exit(1);
+    match cmd {
+        "completions" => {
+            commands::completions(args[1..].to_vec());
+            ExitCode::SUCCESS
+        }
+        "list" => commands::list(args[1..].to_vec()).report(),
+        "mount" => commands::mount(args, symlink_cmd).report(),
+        "subvolume" => commands::subvolume(args[1..].to_vec()).report(),
+        _ => ExitCode::from(u8::try_from(handle_c_command(args, symlink_cmd)).unwrap()),
     }
 }

src/commands/completions.rs

@@ -12,8 +12,7 @@ fn print_completions<G: Generator>(gen: G, cmd: &mut Command) {
     generate(gen, cmd, cmd.get_name().to_string(), &mut io::stdout());
 }
 
-pub fn completions(argv: Vec<String>) -> i32 {
+pub fn completions(argv: Vec<String>) {
     let cli = Cli::parse_from(argv);
     print_completions(cli.shell, &mut super::Cli::command());
-    0
 }

src/commands/list.rs

@@ -1,3 +1,4 @@
+use anyhow::Result;
 use bch_bindgen::bcachefs;
 use bch_bindgen::bkey::BkeySC;
 use bch_bindgen::btree::BtreeIter;
@@ -7,7 +8,6 @@ use bch_bindgen::btree::BtreeTrans;
 use bch_bindgen::fs::Fs;
 use bch_bindgen::opt_set;
 use clap::Parser;
-use log::error;
 use std::io::{stdout, IsTerminal};
 
 use crate::logging;
@@ -201,16 +201,11 @@ fn cmd_list_inner(opt: &Cli) -> anyhow::Result<()> {
     }
 }
 
-pub fn list(argv: Vec<String>) -> i32 {
+pub fn list(argv: Vec<String>) -> Result<()> {
     let opt = Cli::parse_from(argv);
 
     // TODO: centralize this on the top level CLI
     logging::setup(opt.quiet, opt.verbose, opt.colorize);
 
-    if let Err(e) = cmd_list_inner(&opt) {
-        error!("Fatal error: {}", e);
-        1
-    } else {
-        0
-    }
+    cmd_list_inner(&opt)
 }

src/commands/mount.rs

@@ -11,7 +11,7 @@ use std::{
 use anyhow::{ensure, Result};
 use bch_bindgen::{bcachefs, bcachefs::bch_sb_handle, opt_set, path_to_cstr};
 use clap::Parser;
-use log::{debug, error, info};
+use log::{debug, info};
 use uuid::Uuid;
 
 use crate::{
@@ -372,7 +372,7 @@ fn cmd_mount_inner(cli: &Cli) -> Result<()> {
     }
 }
 
-pub fn mount(mut argv: Vec<String>, symlink_cmd: Option<&str>) -> i32 {
+pub fn mount(mut argv: Vec<String>, symlink_cmd: Option<&str>) -> Result<()> {
     // If the bcachefs tool is being called as "bcachefs mount dev ..." (as opposed to via a
     // symlink like "/usr/sbin/mount.bcachefs dev ...", then we need to pop the 0th argument
     // ("bcachefs") since the CLI parser here expects the device at position 1.
@@ -385,11 +385,5 @@ pub fn mount(mut argv: Vec<String>, symlink_cmd: Option<&str>) -> i32 {
     // TODO: centralize this on the top level CLI
     logging::setup(cli.quiet, cli.verbose, cli.colorize);
 
-    if let Err(e) = cmd_mount_inner(&cli) {
-        error!("Fatal error: {}", e);
-        1
-    } else {
-        info!("Successfully mounted");
-        0
-    }
+    cmd_mount_inner(&cli)
 }

src/commands/subvolume.rs

@@ -1,5 +1,6 @@
 use std::{env, path::PathBuf};
 
+use anyhow::{Context, Result};
 use bch_bindgen::c::BCH_SUBVOL_SNAPSHOT_RO;
 use clap::{Parser, Subcommand};
 
@@ -36,7 +37,7 @@ enum Subcommands {
     },
 }
 
-pub fn subvolume(argv: Vec<String>) -> i32 {
+pub fn subvolume(argv: Vec<String>) -> Result<()> {
     let cli = Cli::parse_from(argv);
 
     match cli.subcommands {
@@ -47,25 +48,25 @@ pub fn subvolume(argv: Vec<String>) -> i32 {
                 } else {
                     env::current_dir()
                         .map(|p| p.join(target))
-                        .expect("unable to get current directory")
+                        .context("unable to get current directory")?
                 };
 
                 if let Some(dirname) = target.parent() {
                     let fs = unsafe { BcachefsHandle::open(dirname) };
                     fs.create_subvolume(target)
-                        .expect("Failed to create the subvolume");
+                        .context("Failed to create the subvolume")?;
                 }
             }
         }
         Subcommands::Delete { target } => {
             let target = target
                 .canonicalize()
-                .expect("subvolume path does not exist or can not be canonicalized");
+                .context("subvolume path does not exist or can not be canonicalized")?;
 
             if let Some(dirname) = target.parent() {
                 let fs = unsafe { BcachefsHandle::open(dirname) };
                 fs.delete_subvolume(target)
-                    .expect("Failed to delete the subvolume");
+                    .context("Failed to delete the subvolume")?;
             }
         }
         Subcommands::Snapshot {
@@ -91,10 +92,10 @@ pub fn subvolume(argv: Vec<String>) -> i32 {
                     source,
                     dest,
                 )
-                .expect("Failed to snapshot the subvolume");
+                .context("Failed to snapshot the subvolume")?;
             }
         }
     }
 
-    0
+    Ok(())
 }