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From: Andreas Hindborg <a.hindborg@kernel.org>
To: "Peter Zijlstra" <peterz@infradead.org>,
	"Ingo Molnar" <mingo@redhat.com>, "Will Deacon" <will@kernel.org>,
	"Boqun Feng" <boqun.feng@gmail.com>,
	"Waiman Long" <longman@redhat.com>,
	"Miguel Ojeda" <ojeda@kernel.org>, "Gary Guo" <gary@garyguo.net>,
	"Björn Roy Baron" <bjorn3_gh@protonmail.com>,
	"Benno Lossin" <lossin@kernel.org>,
	"Alice Ryhl" <aliceryhl@google.com>,
	"Trevor Gross" <tmgross@umich.edu>,
	"Danilo Krummrich" <dakr@kernel.org>
Cc: linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org,
	 Andreas Hindborg <a.hindborg@kernel.org>
Subject: [PATCH] rust: sync: export lock::do_unlocked
Date: Sun, 15 Feb 2026 21:15:59 +0100	[thread overview]
Message-ID: <20260215-export-do-unlocked-v1-1-f5cd2203b20f@kernel.org> (raw)

Export lock::do_unlocked publicly. Add documentation for the method.

Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
---
 rust/kernel/sync/lock.rs | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/rust/kernel/sync/lock.rs b/rust/kernel/sync/lock.rs
index 46a57d1fc309d..f390cd7ba0762 100644
--- a/rust/kernel/sync/lock.rs
+++ b/rust/kernel/sync/lock.rs
@@ -235,7 +235,31 @@ pub fn lock_ref(&self) -> &'a Lock<T, B> {
         self.lock
     }
 
-    pub(crate) fn do_unlocked<U>(&mut self, cb: impl FnOnce() -> U) -> U {
+    /// Temporarily unlock the lock to execute the given closure.
+    ///
+    /// This method unlocks the lock before calling the closure `cb`, and re-locks it afterwards.
+    /// This is useful when you need to perform operations that are not allowed while holding
+    /// certain locks, such as allocating memory (which is prohibited while holding a spinlock).
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use kernel::{new_spinlock, prelude::*};
+    /// # use pin_init::stack_pin_init;
+    ///
+    /// stack_pin_init!{
+    ///     let lock = new_spinlock!(())
+    /// }
+    ///
+    /// let mut guard = lock.lock();
+    /// let mut buffer = KVec::new();
+    /// // Temporarily unlock to allocate memory, which should not be done while holding a spinlock.
+    ///  guard.do_unlocked(|| {
+    ///     buffer.push(5u32, GFP_KERNEL)
+    /// })?;
+    /// # Ok::<(), Error>(())
+    /// ```
+    pub fn do_unlocked<U>(&mut self, cb: impl FnOnce() -> U) -> U {
         // SAFETY: The caller owns the lock, so it is safe to unlock it.
         unsafe { B::unlock(self.lock.state.get(), &self.state) };
 

---
base-commit: 05f7e89ab9731565d8a62e3b5d1ec206485eeb0b
change-id: 20260215-export-do-unlocked-00a6ac9373d4

Best regards,
-- 
Andreas Hindborg <a.hindborg@kernel.org>



             reply	other threads:[~2026-02-15 20:16 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-02-15 20:15 Andreas Hindborg [this message]
2026-02-15 23:24 ` Benno Lossin
2026-02-16  7:14   ` Andreas Hindborg
2026-02-16  8:54     ` Alice Ryhl

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