// 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__ */