[mirror_ubuntu-focal-kernel.git] / fs / aufs / rwsem.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (C) 2005-2020 Junjiro R. Okajima
 *
 * This program, aufs is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/*
 * simple read-write semaphore wrappers
 */

#ifndef __AUFS_RWSEM_H__
#define __AUFS_RWSEM_H__

#ifdef __KERNEL__

#include "debug.h"

/* in the future, the name 'au_rwsem' will be totally gone */
#define au_rwsem	rw_semaphore

/* to debug easier, do not make them inlined functions */
#define AuRwMustNoWaiters(rw)	AuDebugOn(rwsem_is_contended(rw))
/* rwsem_is_locked() is unusable */
#define AuRwMustReadLock(rw)	AuDebugOn(!lockdep_recursing(current) \
					  && debug_locks \
					  && !lockdep_is_held_type(rw, 1))
#define AuRwMustWriteLock(rw)	AuDebugOn(!lockdep_recursing(current) \
					  && debug_locks \
					  && !lockdep_is_held_type(rw, 0))
#define AuRwMustAnyLock(rw)	AuDebugOn(!lockdep_recursing(current) \
					  && debug_locks \
					  && !lockdep_is_held(rw))
#define AuRwDestroy(rw)		AuDebugOn(!lockdep_recursing(current) \
					  && debug_locks \
					  && lockdep_is_held(rw))

#define au_rw_init(rw)	init_rwsem(rw)

#define au_rw_init_wlock(rw) do {		\
		au_rw_init(rw);			\
		down_write(rw);			\
	} while (0)

#define au_rw_init_wlock_nested(rw, lsc) do {	\
		au_rw_init(rw);			\
		down_write_nested(rw, lsc);	\
	} while (0)

#define au_rw_read_lock(rw)		down_read(rw)
#define au_rw_read_lock_nested(rw, lsc)	down_read_nested(rw, lsc)
#define au_rw_read_unlock(rw)		up_read(rw)
#define au_rw_dgrade_lock(rw)		downgrade_write(rw)
#define au_rw_write_lock(rw)		down_write(rw)
#define au_rw_write_lock_nested(rw, lsc) down_write_nested(rw, lsc)
#define au_rw_write_unlock(rw)		up_write(rw)
/* why is not _nested version defined? */
#define au_rw_read_trylock(rw)		down_read_trylock(rw)
#define au_rw_write_trylock(rw)		down_write_trylock(rw)

#endif /* __KERNEL__ */
#endif /* __AUFS_RWSEM_H__ */
Commit	Line	Data
a3a49a17 SF	1	/* SPDX-License-Identifier: GPL-2.0 */
a3a49a17 SF	2	/*
e4a3f096	3	* Copyright (C) 2005-2020 Junjiro R. Okajima
a3a49a17 SF	4	*
	5	* This program, aufs is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License as published by
	7	* the Free Software Foundation; either version 2 of the License, or
	8	* (at your option) any later version.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	17	*/
	18
	19	/*
	20	* simple read-write semaphore wrappers
	21	*/
	22
	23	#ifndef __AUFS_RWSEM_H__
	24	#define __AUFS_RWSEM_H__
	25
	26	#ifdef __KERNEL__
	27
	28	#include "debug.h"
	29
	30	/* in the future, the name 'au_rwsem' will be totally gone */
	31	#define au_rwsem rw_semaphore
	32
	33	/* to debug easier, do not make them inlined functions */
	34	#define AuRwMustNoWaiters(rw) AuDebugOn(rwsem_is_contended(rw))
	35	/* rwsem_is_locked() is unusable */
	36	#define AuRwMustReadLock(rw) AuDebugOn(!lockdep_recursing(current) \
	37	&& debug_locks \
	38	&& !lockdep_is_held_type(rw, 1))
	39	#define AuRwMustWriteLock(rw) AuDebugOn(!lockdep_recursing(current) \
	40	&& debug_locks \
	41	&& !lockdep_is_held_type(rw, 0))
	42	#define AuRwMustAnyLock(rw) AuDebugOn(!lockdep_recursing(current) \
	43	&& debug_locks \
	44	&& !lockdep_is_held(rw))
	45	#define AuRwDestroy(rw) AuDebugOn(!lockdep_recursing(current) \
	46	&& debug_locks \
	47	&& lockdep_is_held(rw))
	48
	49	#define au_rw_init(rw) init_rwsem(rw)
	50
	51	#define au_rw_init_wlock(rw) do { \
	52	au_rw_init(rw); \
	53	down_write(rw); \
	54	} while (0)
	55
	56	#define au_rw_init_wlock_nested(rw, lsc) do { \
	57	au_rw_init(rw); \
	58	down_write_nested(rw, lsc); \
	59	} while (0)
	60
	61	#define au_rw_read_lock(rw) down_read(rw)
	62	#define au_rw_read_lock_nested(rw, lsc) down_read_nested(rw, lsc)
	63	#define au_rw_read_unlock(rw) up_read(rw)
	64	#define au_rw_dgrade_lock(rw) downgrade_write(rw)
	65	#define au_rw_write_lock(rw) down_write(rw)
	66	#define au_rw_write_lock_nested(rw, lsc) down_write_nested(rw, lsc)
	67	#define au_rw_write_unlock(rw) up_write(rw)
68	/* why is not _nested version defined? */
69	#define au_rw_read_trylock(rw) down_read_trylock(rw)
70	#define au_rw_write_trylock(rw) down_write_trylock(rw)
71
72	#endif /* __KERNEL__ */
73	#endif /* __AUFS_RWSEM_H__ */