^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Copyright (c) 2000-2006 Silicon Graphics, Inc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * All Rights Reserved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) #ifndef __XFS_SUPPORT_MRLOCK_H__
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #define __XFS_SUPPORT_MRLOCK_H__
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/rwsem.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) typedef struct {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) struct rw_semaphore mr_lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #if defined(DEBUG) || defined(XFS_WARN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) int mr_writer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) } mrlock_t;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #if defined(DEBUG) || defined(XFS_WARN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #define mrinit(mrp, name) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) do { (mrp)->mr_writer = 0; init_rwsem(&(mrp)->mr_lock); } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #define mrinit(mrp, name) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) do { init_rwsem(&(mrp)->mr_lock); } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #define mrlock_init(mrp, t,n,s) mrinit(mrp, n)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #define mrfree(mrp) do { } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) static inline void mraccess_nested(mrlock_t *mrp, int subclass)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) down_read_nested(&mrp->mr_lock, subclass);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) static inline void mrupdate_nested(mrlock_t *mrp, int subclass)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) down_write_nested(&mrp->mr_lock, subclass);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) #if defined(DEBUG) || defined(XFS_WARN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) mrp->mr_writer = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) static inline int mrtryaccess(mrlock_t *mrp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) return down_read_trylock(&mrp->mr_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) static inline int mrtryupdate(mrlock_t *mrp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) if (!down_write_trylock(&mrp->mr_lock))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) #if defined(DEBUG) || defined(XFS_WARN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) mrp->mr_writer = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) static inline void mrunlock_excl(mrlock_t *mrp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) #if defined(DEBUG) || defined(XFS_WARN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) mrp->mr_writer = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) up_write(&mrp->mr_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) static inline void mrunlock_shared(mrlock_t *mrp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) up_read(&mrp->mr_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) static inline void mrdemote(mrlock_t *mrp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) #if defined(DEBUG) || defined(XFS_WARN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) mrp->mr_writer = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) downgrade_write(&mrp->mr_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) #endif /* __XFS_SUPPORT_MRLOCK_H__ */