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78 lines
1.6 KiB
78 lines
1.6 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright (c) 2000-2006 Silicon Graphics, Inc. |
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* All Rights Reserved. |
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*/ |
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#ifndef __XFS_SUPPORT_MRLOCK_H__ |
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#define __XFS_SUPPORT_MRLOCK_H__ |
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#include <linux/rwsem.h> |
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typedef struct { |
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struct rw_semaphore mr_lock; |
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#if defined(DEBUG) || defined(XFS_WARN) |
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int mr_writer; |
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#endif |
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} mrlock_t; |
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#if defined(DEBUG) || defined(XFS_WARN) |
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#define mrinit(mrp, name) \ |
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do { (mrp)->mr_writer = 0; init_rwsem(&(mrp)->mr_lock); } while (0) |
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#else |
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#define mrinit(mrp, name) \ |
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do { init_rwsem(&(mrp)->mr_lock); } while (0) |
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#endif |
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#define mrlock_init(mrp, t,n,s) mrinit(mrp, n) |
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#define mrfree(mrp) do { } while (0) |
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static inline void mraccess_nested(mrlock_t *mrp, int subclass) |
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{ |
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down_read_nested(&mrp->mr_lock, subclass); |
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} |
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static inline void mrupdate_nested(mrlock_t *mrp, int subclass) |
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{ |
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down_write_nested(&mrp->mr_lock, subclass); |
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#if defined(DEBUG) || defined(XFS_WARN) |
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mrp->mr_writer = 1; |
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#endif |
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} |
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static inline int mrtryaccess(mrlock_t *mrp) |
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{ |
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return down_read_trylock(&mrp->mr_lock); |
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} |
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static inline int mrtryupdate(mrlock_t *mrp) |
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{ |
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if (!down_write_trylock(&mrp->mr_lock)) |
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return 0; |
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#if defined(DEBUG) || defined(XFS_WARN) |
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mrp->mr_writer = 1; |
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#endif |
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return 1; |
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} |
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static inline void mrunlock_excl(mrlock_t *mrp) |
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{ |
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#if defined(DEBUG) || defined(XFS_WARN) |
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mrp->mr_writer = 0; |
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#endif |
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up_write(&mrp->mr_lock); |
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} |
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static inline void mrunlock_shared(mrlock_t *mrp) |
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{ |
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up_read(&mrp->mr_lock); |
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} |
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static inline void mrdemote(mrlock_t *mrp) |
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{ |
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#if defined(DEBUG) || defined(XFS_WARN) |
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mrp->mr_writer = 0; |
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#endif |
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downgrade_write(&mrp->mr_lock); |
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} |
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#endif /* __XFS_SUPPORT_MRLOCK_H__ */
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