diff options
Diffstat (limited to 'fs/aufs/rwsem.h')
-rw-r--r-- | fs/aufs/rwsem.h | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/fs/aufs/rwsem.h b/fs/aufs/rwsem.h new file mode 100644 index 000000000000..22ff55e6c644 --- /dev/null +++ b/fs/aufs/rwsem.h @@ -0,0 +1,73 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2005-2018 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 futre, 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__ */ |