diff options
Diffstat (limited to 'fs/xfs/mrlock.h')
| -rw-r--r-- | fs/xfs/mrlock.h | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/fs/xfs/mrlock.h b/fs/xfs/mrlock.h new file mode 100644 index 0000000000..79155eec34 --- /dev/null +++ b/fs/xfs/mrlock.h @@ -0,0 +1,78 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2000-2006 Silicon Graphics, Inc. + * All Rights Reserved. + */ +#ifndef __XFS_SUPPORT_MRLOCK_H__ +#define __XFS_SUPPORT_MRLOCK_H__ + +#include <linux/rwsem.h> + +typedef struct { + struct rw_semaphore mr_lock; +#if defined(DEBUG) || defined(XFS_WARN) + int mr_writer; +#endif +} mrlock_t; + +#if defined(DEBUG) || defined(XFS_WARN) +#define mrinit(mrp, name) \ + do { (mrp)->mr_writer = 0; init_rwsem(&(mrp)->mr_lock); } while (0) +#else +#define mrinit(mrp, name) \ + do { init_rwsem(&(mrp)->mr_lock); } while (0) +#endif + +#define mrlock_init(mrp, t,n,s) mrinit(mrp, n) +#define mrfree(mrp) do { } while (0) + +static inline void mraccess_nested(mrlock_t *mrp, int subclass) +{ + down_read_nested(&mrp->mr_lock, subclass); +} + +static inline void mrupdate_nested(mrlock_t *mrp, int subclass) +{ + down_write_nested(&mrp->mr_lock, subclass); +#if defined(DEBUG) || defined(XFS_WARN) + mrp->mr_writer = 1; +#endif +} + +static inline int mrtryaccess(mrlock_t *mrp) +{ + return down_read_trylock(&mrp->mr_lock); +} + +static inline int mrtryupdate(mrlock_t *mrp) +{ + if (!down_write_trylock(&mrp->mr_lock)) + return 0; +#if defined(DEBUG) || defined(XFS_WARN) + mrp->mr_writer = 1; +#endif + return 1; +} + +static inline void mrunlock_excl(mrlock_t *mrp) +{ +#if defined(DEBUG) || defined(XFS_WARN) + mrp->mr_writer = 0; +#endif + up_write(&mrp->mr_lock); +} + +static inline void mrunlock_shared(mrlock_t *mrp) +{ + up_read(&mrp->mr_lock); +} + +static inline void mrdemote(mrlock_t *mrp) +{ +#if defined(DEBUG) || defined(XFS_WARN) + mrp->mr_writer = 0; +#endif + downgrade_write(&mrp->mr_lock); +} + +#endif /* __XFS_SUPPORT_MRLOCK_H__ */ |