rust-src: Clean up read_super bindings

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

rust-src/bch_bindgen/build.rs

@@ -52,6 +52,8 @@ fn main() {
         .allowlist_type("bch_sb_field_.*")
         .allowlist_type("bch_encrypted_key")
         .allowlist_type("nonce")
+        .allowlist_type("bch_errcode")
+        .allowlist_function("bch2_err_str")
         .newtype_enum("bch_kdf_types")
         .opaque_type("gendisk")
         .opaque_type("bkey")

rust-src/bch_bindgen/src/libbcachefs_wrapper.h

@@ -1,6 +1,7 @@
 #include "../libbcachefs/super-io.h"
 #include "../libbcachefs/checksum.h"
 #include "../libbcachefs/bcachefs_format.h"
+#include "../libbcachefs/errcode.h"
 #include "../libbcachefs/opts.h"
 #include "../libbcachefs.h"
 #include "../crypto.h"

rust-src/bch_bindgen/src/rs.rs

@@ -1,57 +1,37 @@
+use anyhow::anyhow;
 use crate::bcachefs;
-use crate::{error, info};
-use colored::Colorize;
+use crate::bcachefs::*;
+use std::ffi::CStr;
+use std::fmt;
 
-pub const SUPERBLOCK_MAGIC: uuid::Uuid =
-    uuid::Uuid::from_u128(0x_c68573f6_4e1a_45ca_8265_f57f48ba6d81);
-
-extern "C" {
-    pub static stdout: *mut libc::FILE;
+impl fmt::Display for bch_errcode {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let s = unsafe { CStr::from_ptr(bch2_err_str(*self as i32)) };
+        write!(f, "{:?}", s)
+    }
 }
 
-pub enum ReadSuperErr {
-    Io(std::io::Error),
-}
-
-type RResult<T> = std::io::Result<std::io::Result<T>>;
-
 pub fn read_super_opts(
     path: &std::path::Path,
-    mut opts: bcachefs::bch_opts,
-) -> RResult<bcachefs::bch_sb_handle> {
+    mut opts: bch_opts,
+) -> anyhow::Result<bch_sb_handle> {
     use std::os::unix::ffi::OsStrExt;
-    let path = std::ffi::CString::new(path.as_os_str().as_bytes())?;
+    let path = std::ffi::CString::new(path.as_os_str().as_bytes()).unwrap();
 
     let mut sb = std::mem::MaybeUninit::zeroed();
 
     let ret =
         unsafe { crate::bcachefs::bch2_read_super(path.as_ptr(), &mut opts, sb.as_mut_ptr()) };
-    println!("{}", ret);
 
-    info!("something");
-    error!("an error");
-    String::from("something").bright_black();
-    match -ret {
-        libc::EACCES => Err(std::io::Error::new(
-            std::io::ErrorKind::PermissionDenied,
-            "Access Permission Denied",
-        )),
-        0 => Ok(Ok(unsafe { sb.assume_init() })),
-        22 => Ok(Err(std::io::Error::new(
-            std::io::ErrorKind::InvalidData,
-            "Not a BCacheFS SuperBlock",
-        ))),
-        code => {
-            println!("BCacheFS return error code: {}", code);
-            Ok(Err(std::io::Error::new(
-                std::io::ErrorKind::Other,
-                "Failed to Read SuperBlock",
-            )))
-        }
+    if ret != 0 {
+        let err: bch_errcode = unsafe { ::std::mem::transmute(ret) };
+        Err(anyhow!(err))
+    } else {
+        Ok(unsafe { sb.assume_init() })
     }
 }
 
-pub fn read_super(path: &std::path::Path) -> RResult<bcachefs::bch_sb_handle> {
-    let opts = bcachefs::bch_opts::default(); //unsafe {std::mem::MaybeUninit::zeroed().assume_init()};
+pub fn read_super(path: &std::path::Path) -> anyhow::Result<bch_sb_handle> {
+    let opts = bcachefs::bch_opts::default();
     read_super_opts(path, opts)
 }

rust-src/src/cmd_mount.rs

@@ -101,11 +101,11 @@ fn mount(
     mount_inner(device, target, "bcachefs", mountflags, data)
 }
 
-fn read_super_silent(path: &std::path::PathBuf) -> std::io::Result<bch_sb_handle> {
+fn read_super_silent(path: &std::path::PathBuf) -> anyhow::Result<bch_sb_handle> {
     // Stop libbcachefs from spamming the output
     let _gag = gag::BufferRedirect::stdout().unwrap();
 
-    bch_bindgen::rs::read_super(&path)?
+    bch_bindgen::rs::read_super(&path)
 }
 
 fn get_devices_by_uuid(uuid: Uuid) -> anyhow::Result<Vec<(PathBuf, bch_sb_handle)>> {
@@ -182,7 +182,7 @@ fn cmd_mount_inner(opt: Cli) -> anyhow::Result<()> {
 
         for dev in opt.dev.split(':') {
             let dev = PathBuf::from(dev);
-            sbs.push(bch_bindgen::rs::read_super(&dev)??);
+            sbs.push(bch_bindgen::rs::read_super(&dev)?);
         }
 
         (opt.dev, sbs)