[PATCH v3 3/5] rust: block: gen_disk: use DropGuard

[Mohamed Osama]

Replace the ScopeGuard instances in the Rust block layer generic disk
implementation with DropGuard.

DropGuard provides the same scope-exit cleanup behavior while using the
new Rust kernel memory API.

Signed-off-by: Mohamed Osama <mohamed.osama189110@xxxxxxxxx>
---
 rust/kernel/block/mq/gen_disk.rs | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/rust/kernel/block/mq/gen_disk.rs b/rust/kernel/block/mq/gen_disk.rs
index fc97dd873974..d9019fbbb361 100644
--- a/rust/kernel/block/mq/gen_disk.rs
+++ b/rust/kernel/block/mq/gen_disk.rs
@@ -10,11 +10,12 @@
     block::mq::{Operations, TagSet},
     error::{self, from_err_ptr, Result},
     fmt::{self, Write},
+    mem::DropGuard,
     prelude::*,
     static_lock_class,
     str::NullTerminatedFormatter,
     sync::Arc,
-    types::{ForeignOwnable, ScopeGuard},
+    types::ForeignOwnable,
 };
 
 /// A builder for [`GenDisk`].
@@ -102,7 +103,7 @@ pub fn build<T: Operations>(
         queue_data: T::QueueData,
     ) -> Result<GenDisk<T>> {
         let data = queue_data.into_foreign();
-        let recover_data = ScopeGuard::new(|| {
+        let recover_data = DropGuard::new((), |_| {
             // SAFETY: T::QueueData was created by the call to `into_foreign()` above
             drop(unsafe { T::QueueData::from_foreign(data) });
         });
@@ -150,7 +151,7 @@ pub fn build<T: Operations>(
         // SAFETY: `gendisk` is a valid pointer as we initialized it above
         unsafe { (*gendisk).fops = &TABLE };
 
-        let cleanup_failure = ScopeGuard::new_with_data((gendisk, data), |(gendisk, data)| {
+        let cleanup_failure = DropGuard::new((gendisk, data), |(gendisk, data)| {
             // SAFETY: `gendisk` came from `__blk_mq_alloc_disk()` above and
             // has not been added to the VFS on this cleanup path.
             unsafe { bindings::put_disk(gendisk) };
@@ -161,7 +162,7 @@ pub fn build<T: Operations>(
 
         // The failure guard now owns both pieces of cleanup; the early guard
         // must not run on this path anymore.
-        recover_data.dismiss();
+        DropGuard::dismiss(recover_data);
 
         let mut writer = NullTerminatedFormatter::new(
             // SAFETY: `gendisk` points to a valid and initialized instance. We
@@ -185,7 +186,7 @@ pub fn build<T: Operations>(
             },
         )?;
 
-        cleanup_failure.dismiss();
+        DropGuard::dismiss(cleanup_failure);
 
         // INVARIANT: `gendisk` was initialized above.
         // INVARIANT: `gendisk` was added to the VFS via `device_add_disk` above.
-- 
2.43.0