refactor: casting-related clippy::pedantic fixes

Prefer using `ptr::addr_of!()` and `pointer::cast()` instead of raw `as`
where clippy complains and other type casting lints.

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

src/bcachefs.rs

@@ -28,7 +28,7 @@ fn handle_c_command(mut argv: Vec<String>, symlink_cmd: Option<&str>) -> i32 {
     let argv: Vec<_> = argv.into_iter().map(|s| CString::new(s).unwrap()).collect();
     let mut argv = argv
         .into_iter()
-        .map(|s| Box::into_raw(s.into_boxed_c_str()) as *mut c_char)
+        .map(|s| Box::into_raw(s.into_boxed_c_str()).cast::<c_char>())
         .collect::<Box<[*mut c_char]>>();
     let argv = argv.as_mut_ptr();
 

src/commands/mount.rs

@@ -1,9 +1,11 @@
 use std::{
     collections::HashMap,
-    ffi::{c_char, c_void, CString},
+    env,
+    ffi::CString,
+    fs,
     io::{stdout, IsTerminal},
     path::{Path, PathBuf},
-    {env, fs, str},
+    ptr, str,
 };
 
 use anyhow::{ensure, Result};
@@ -28,12 +30,10 @@ fn mount_inner(
     let fstype = CString::new(fstype)?;
 
     // convert to pointers for ffi
-    let src = src.as_c_str().to_bytes_with_nul().as_ptr() as *const c_char;
-    let target = target.as_c_str().to_bytes_with_nul().as_ptr() as *const c_char;
-    let data = data.as_ref().map_or(std::ptr::null(), |data| {
-        data.as_c_str().to_bytes_with_nul().as_ptr() as *const c_void
-    });
-    let fstype = fstype.as_c_str().to_bytes_with_nul().as_ptr() as *const c_char;
+    let src = src.as_ptr();
+    let target = target.as_ptr();
+    let data = data.map_or(ptr::null(), |data| data.as_ptr().cast());
+    let fstype = fstype.as_ptr();
 
     let ret = {
         info!("mounting filesystem");

src/key.rs

@@ -4,7 +4,7 @@ use std::{
     io::{stdin, IsTerminal},
     mem,
     path::Path,
-    thread,
+    ptr, thread,
     time::Duration,
 };
 
@@ -66,7 +66,7 @@ impl KeyHandle {
         let bch_key_magic = BCH_KEY_MAGIC.as_bytes().read_u64::<LittleEndian>().unwrap();
 
         let crypt = sb.sb().crypt().unwrap();
-        let crypt_ptr = crypt as *const _ as *mut _;
+        let crypt_ptr = ptr::addr_of!(*crypt).cast_mut();
 
         let mut output: bch_key =
             unsafe { bcachefs::derive_passphrase(crypt_ptr, passphrase.get().as_ptr()) };
@@ -75,9 +75,9 @@ impl KeyHandle {
 
         let ret = unsafe {
             bch2_chacha_encrypt_key(
-                &mut output as *mut _,
+                ptr::addr_of_mut!(output),
                 sb.sb().nonce(),
-                &mut key as *mut _ as *mut _,
+                ptr::addr_of_mut!(key).cast(),
                 mem::size_of_val(&key),
             )
         };
@@ -93,7 +93,7 @@ impl KeyHandle {
             keyutils::add_key(
                 key_type,
                 key_name,
-                &output as *const _ as *const _,
+                ptr::addr_of!(output).cast(),
                 mem::size_of_val(&output),
                 keyutils::KEY_SPEC_USER_KEYRING,
             )
@@ -103,7 +103,7 @@ impl KeyHandle {
             info!("Found key in keyring");
             Ok(KeyHandle {
                 _uuid: sb.sb().uuid(),
-                _id:   key_id as c_long,
+                _id:   c_long::from(key_id),
             })
         } else {
             Err(anyhow!("failed to add key to keyring: {}", errno::errno()))

src/wrappers/handle.rs

@@ -1,4 +1,4 @@
-use std::path::Path;
+use std::{path::Path, ptr};
 
 use bch_bindgen::c::{
     bcache_fs_close, bcache_fs_open, bch_ioctl_subvolume, bchfs_handle, BCH_IOCTL_SUBVOLUME_CREATE,
@@ -42,7 +42,7 @@ pub enum BcachefsIoctlPayload {
 impl From<&BcachefsIoctlPayload> for *const libc::c_void {
     fn from(value: &BcachefsIoctlPayload) -> Self {
         match value {
-            BcachefsIoctlPayload::Subvolume(p) => p as *const _ as *const libc::c_void,
+            BcachefsIoctlPayload::Subvolume(p) => ptr::addr_of!(p).cast(),
         }
     }
 }