[PATCH] liveupdate: use scoped_guard for mutex in session operations

[PATCH] liveupdate: use scoped_guard for mutex in session operations

[Chenghao Duan]

Replace manually paired mutex_lock/unlock with scoped_guard to align
with the coding style of the rest of the codebase and simplify locking
paths.

Signed-off-by: Chenghao Duan <duanchenghao@kylinos.cn>
---
 kernel/liveupdate/luo_session.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/kernel/liveupdate/luo_session.c b/kernel/liveupdate/luo_session.c
index f38b5b18f3f8..06307868a44e 100644
--- a/kernel/liveupdate/luo_session.c
+++ b/kernel/liveupdate/luo_session.c
@@ -290,9 +290,8 @@ static int luo_session_retrieve_fd(struct luo_session *session,
 	if (argp->fd < 0)
 		return argp->fd;
 
-	mutex_lock(&session->mutex);
-	err = luo_retrieve_file(&session->file_set, argp->token, &file);
-	mutex_unlock(&session->mutex);
+	scoped_guard(mutex, &session->mutex)
+		err = luo_retrieve_file(&session->file_set, argp->token, &file);
 	if (err < 0)
 		goto err_put_fd;
 
@@ -478,9 +477,8 @@ int luo_session_create(const char *name, struct file **filep)
 	if (err)
 		goto err_free;
 
-	mutex_lock(&session->mutex);
-	err = luo_session_getfile(session, filep);
-	mutex_unlock(&session->mutex);
+	scoped_guard(mutex, &session->mutex)
+		err = luo_session_getfile(session, filep);
 	if (err)
 		goto err_remove;
 	up_read(&luo_session_serialize_rwsem);
-- 
2.25.1

Re: [PATCH] liveupdate: use scoped_guard for mutex in session operations

[Pratyush Yadav]

On Fri, Aug 14 2026, Chenghao Duan wrote:

> Replace manually paired mutex_lock/unlock with scoped_guard to align
> with the coding style of the rest of the codebase and simplify locking
> paths.

No. This is done explicitly because we don't want to mix gotos with the
automatic cleanup-style locking. I don't think we should change this.

[...]

-- 
Regards,
Pratyush Yadav

Re: [PATCH] liveupdate: use scoped_guard for mutex in session operations

[Chenghao Duan]

On Fri, Aug 14, 2026 at 04:10:34PM +0200, Pratyush Yadav wrote:
> On Fri, Aug 14 2026, Chenghao Duan wrote:
> 
> > Replace manually paired mutex_lock/unlock with scoped_guard to align
> > with the coding style of the rest of the codebase and simplify locking
> > paths.
> 
> No. This is done explicitly because we don't want to mix gotos with the
> automatic cleanup-style locking. I don't think we should change this.
> 

Thank you for the clarification. I understand your concern about mixing
`goto`-based error handling with automatic cleanup-style locking.

I was wondering if these particular cases might still be suitable for
using `scoped_guard()`. The patch only changes two manually paired mutex
lock/unlock instances, and in both cases, the guard scope is limited to
the operation that requires the mutex. The lock is released before the
subsequent error-handling logic is executed, so the `goto` paths do not
cross the scope of the guard.

We could also use an explicit `scoped_guard { ... }` scope to make the
lifetime of the guard more obvious and easier to review.

Of course, I may be missing some broader considerations. If there are
other reasons why these cases should retain the explicit lock/unlock
pattern, I would be happy to follow your guidance.

Regards,
Chenghao

> [...]
> 
> -- 
> Regards,
> Pratyush Yadav