bindgen: implement Drop for bch_sb_handle

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

bch_bindgen/build.rs

@@ -91,6 +91,7 @@ fn main() {
         .allowlist_type("sb_names")
         .no_copy("btree_trans")
         .no_copy("printbuf")
+        .no_copy("bch_sb_handle")
         .no_partialeq("bkey")
         .no_partialeq("bpos")
         .generate_inline_functions(true)

bch_bindgen/src/bcachefs.rs

@@ -91,6 +91,12 @@ impl bch_sb_handle {
     }
 }
 
+impl Drop for bch_sb_handle {
+    fn drop(&mut self) {
+        unsafe { bch2_free_super(&mut *self); }
+    }
+}
+
 // #[repr(u8)]
 pub enum rhash_lock_head {}
 pub enum srcu_struct {}

src/commands/mount.rs

@@ -141,7 +141,7 @@ fn cmd_mount_inner(cli: &Cli) -> Result<()> {
     let opts = bch_bindgen::opts::parse_mount_opts(None, optstr.as_deref(), true)
         .unwrap_or_default();
 
-    let mut sbs = device_scan::scan_sbs(&cli.dev, &opts)?;
+    let sbs = device_scan::scan_sbs(&cli.dev, &opts)?;
 
     ensure!(!sbs.is_empty(), "No device(s) to mount specified");
 
@@ -152,11 +152,6 @@ fn cmd_mount_inner(cli: &Cli) -> Result<()> {
         handle_unlock(cli, first_sb)?;
     }
 
-    for sb in &mut sbs {
-        unsafe {
-            bch_bindgen::sb_io::bch2_free_super(&mut sb.1);
-        }
-    }
     drop(sbs);
 
     if let Some(mountpoint) = cli.mountpoint.as_deref() {

src/device_scan.rs

@@ -172,13 +172,7 @@ pub fn joined_device_str(sbs: &Vec<(PathBuf, bch_sb_handle)>) -> OsString {
 }
 
 pub fn scan_devices(device: &String, opts: &bch_opts) -> Result<OsString> {
-    let mut sbs = scan_sbs(device, opts)?;
-
-    for sb in &mut sbs {
-        unsafe {
-            bch_bindgen::sb_io::bch2_free_super(&mut sb.1);
-        }
-    }
+    let sbs = scan_sbs(device, opts)?;
 
     Ok(joined_device_str(&sbs))
 }