rust: task: Mark Task methods inline

When building the kernel using the llvm-18.1.3-rust-1.85.0-x86_64
toolchain provided by kernel.org, the following symbols are generated:

$ nm vmlinux | grep ' _R'.*Task | rustfilt
... T <kernel::task::Task>::get_pid_ns
... T <kernel::task::Task>::tgid_nr_ns
... T <kernel::task::Task>::current_pid_ns
... T <kernel::task::Task>::signal_pending
... T <kernel::task::Task>::uid
... T <kernel::task::Task>::euid
... T <kernel::task::Task>::current
... T <kernel::task::Task>::wake_up
... T <kernel::task::Task as kernel::types::AlwaysRefCounted>::dec_ref
... T <kernel::task::Task as kernel::types::AlwaysRefCounted>::inc_ref

These Rust symbols are trivial wrappers around the C functions. It
doesn't make sense to go through a trivial wrapper for these functions,
so mark them inline.

[boqun: Capitalize the title, reword a bit to avoid listing all the C
functions as the code already shows them and remove the addresses of the
symbols in the commit log as they are different from build to build.]

Link: https://github.com/Rust-for-Linux/linux/issues/1145
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Christian Schrefl <chrisi.schrefl@gmail.com>
Reviewed-by: Charalampos Mitrodimas <charmitro@posteo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Panagiotis Foliadis <pfoliadis@posteo.net>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20250315-inline-c-wrappers-v3-1-048e43fcef7d@posteo.net

rust/kernel/task.rs

@@ -173,6 +173,7 @@ impl Task {
     /// Callers must ensure that the returned object is only used to access a [`CurrentTask`]
     /// within the task context that was active when this function was called. For more details,
     /// see the invariants section for [`CurrentTask`].
+    #[inline]
     pub unsafe fn current() -> impl Deref<Target = CurrentTask> {
         struct TaskRef {
             task: *const CurrentTask,
@@ -222,24 +223,28 @@ impl Task {
     }
 
     /// Returns the UID of the given task.
+    #[inline]
     pub fn uid(&self) -> Kuid {
         // SAFETY: It's always safe to call `task_uid` on a valid task.
         Kuid::from_raw(unsafe { bindings::task_uid(self.as_ptr()) })
     }
 
     /// Returns the effective UID of the given task.
+    #[inline]
     pub fn euid(&self) -> Kuid {
         // SAFETY: It's always safe to call `task_euid` on a valid task.
         Kuid::from_raw(unsafe { bindings::task_euid(self.as_ptr()) })
     }
 
     /// Determines whether the given task has pending signals.
+    #[inline]
     pub fn signal_pending(&self) -> bool {
         // SAFETY: It's always safe to call `signal_pending` on a valid task.
         unsafe { bindings::signal_pending(self.as_ptr()) != 0 }
     }
 
     /// Returns task's pid namespace with elevated reference count
+    #[inline]
     pub fn get_pid_ns(&self) -> Option<ARef<PidNamespace>> {
         // SAFETY: By the type invariant, we know that `self.0` is valid.
         let ptr = unsafe { bindings::task_get_pid_ns(self.as_ptr()) };
@@ -255,6 +260,7 @@ impl Task {
 
     /// Returns the given task's pid in the provided pid namespace.
     #[doc(alias = "task_tgid_nr_ns")]
+    #[inline]
     pub fn tgid_nr_ns(&self, pidns: Option<&PidNamespace>) -> Pid {
         let pidns = match pidns {
             Some(pidns) => pidns.as_ptr(),
@@ -268,6 +274,7 @@ impl Task {
     }
 
     /// Wakes up the task.
+    #[inline]
     pub fn wake_up(&self) {
         // SAFETY: It's always safe to call `wake_up_process` on a valid task, even if the task
         // running.
@@ -341,11 +348,13 @@ impl CurrentTask {
 
 // SAFETY: The type invariants guarantee that `Task` is always refcounted.
 unsafe impl crate::types::AlwaysRefCounted for Task {
+    #[inline]
     fn inc_ref(&self) {
         // SAFETY: The existence of a shared reference means that the refcount is nonzero.
         unsafe { bindings::get_task_struct(self.as_ptr()) };
     }
 
+    #[inline]
     unsafe fn dec_ref(obj: ptr::NonNull<Self>) {
         // SAFETY: The safety requirements guarantee that the refcount is nonzero.
         unsafe { bindings::put_task_struct(obj.cast().as_ptr()) }