Commit c995e638 authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

locking/rwsem: Fold __down_{read,write}*() 



There's a lot needless duplication in __down_{read,write}*(), cure
that with a helper.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201207090243.GE3040@hirez.programming.kicks-ass.net
parent 285c61ae

kernel/locking/rwsem.c

+23 −22
Original line number Diff line number Diff line
@@ -1354,32 +1354,29 @@ static struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem) 
/*

 * lock for reading

 */

static inline void __down_read(struct rw_semaphore *sem)

static inline int __down_read_common(struct rw_semaphore *sem, int state)

{

	if (!rwsem_read_trylock(sem)) {

		rwsem_down_read_slowpath(sem, TASK_UNINTERRUPTIBLE);

		if (IS_ERR(rwsem_down_read_slowpath(sem, state)))

			return -EINTR;

		DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem);

	}

	return 0;

}



static inline int __down_read_interruptible(struct rw_semaphore *sem)

static inline void __down_read(struct rw_semaphore *sem)

{

	if (!rwsem_read_trylock(sem)) {

		if (IS_ERR(rwsem_down_read_slowpath(sem, TASK_INTERRUPTIBLE)))

			return -EINTR;

		DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem);

	__down_read_common(sem, TASK_UNINTERRUPTIBLE);

}

	return 0;



static inline int __down_read_interruptible(struct rw_semaphore *sem)

{

	return __down_read_common(sem, TASK_INTERRUPTIBLE);

}



static inline int __down_read_killable(struct rw_semaphore *sem)

{

	if (!rwsem_read_trylock(sem)) {

		if (IS_ERR(rwsem_down_read_slowpath(sem, TASK_KILLABLE)))

			return -EINTR;

		DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem);

	}

	return 0;

	return __down_read_common(sem, TASK_KILLABLE);

}



static inline int __down_read_trylock(struct rw_semaphore *sem)
@@ -1405,22 +1402,26 @@ static inline int __down_read_trylock(struct rw_semaphore *sem) 
/*

 * lock for writing

 */

static inline void __down_write(struct rw_semaphore *sem)

{

	if (unlikely(!rwsem_write_trylock(sem)))

		rwsem_down_write_slowpath(sem, TASK_UNINTERRUPTIBLE);

}



static inline int __down_write_killable(struct rw_semaphore *sem)

static inline int __down_write_common(struct rw_semaphore *sem, int state)

{

	if (unlikely(!rwsem_write_trylock(sem))) {

		if (IS_ERR(rwsem_down_write_slowpath(sem, TASK_KILLABLE)))

		if (IS_ERR(rwsem_down_write_slowpath(sem, state)))

			return -EINTR;

	}



	return 0;

}



static inline void __down_write(struct rw_semaphore *sem)

{

	__down_write_common(sem, TASK_UNINTERRUPTIBLE);

}



static inline int __down_write_killable(struct rw_semaphore *sem)

{

	return __down_write_common(sem, TASK_KILLABLE);

}



static inline int __down_write_trylock(struct rw_semaphore *sem)

{

	DEBUG_RWSEMS_WARN_ON(sem->magic != sem, sem);