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/*****************************************************************************\
* Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
* Copyright (C) 2007 The Regents of the University of California.
* Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
* Written by Brian Behlendorf <behlendorf1@llnl.gov>.
* UCRL-CODE-235197
*
* This file is part of the SPL, Solaris Porting Layer.
* For details, see <http://github.com/behlendorf/spl/>.
*
* The SPL 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.
*
* The SPL 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 the SPL. If not, see <http://www.gnu.org/licenses/>.
\*****************************************************************************/
#ifndef _SPL_RWSEM_COMPAT_H
#define _SPL_RWSEM_COMPAT_H
#include <linux/rwsem.h>
#ifdef RWSEM_SPINLOCK_IS_RAW
#define spl_rwsem_lock_irqsave(lock, flags) \
({ \
raw_spin_lock_irqsave(lock, flags); \
})
#define spl_rwsem_unlock_irqrestore(lock, flags) \
({ \
raw_spin_unlock_irqrestore(lock, flags); \
})
#else
#define spl_rwsem_lock_irqsave(lock, flags) \
({ \
spin_lock_irqsave(lock, flags); \
})
#define spl_rwsem_unlock_irqrestore(lock, flags) \
({ \
spin_unlock_irqrestore(lock, flags); \
})
#endif /* RWSEM_SPINLOCK_IS_RAW */
#ifdef RWSEM_IS_LOCKED_TAKES_WAIT_LOCK
/*
* A race condition in rwsem_is_locked() was fixed in Linux 2.6.33 and the fix
* was backported to RHEL5 as of kernel 2.6.18-190.el5. Details can be found
* here:
*
* https://bugzilla.redhat.com/show_bug.cgi?id=526092
* The race condition was fixed in the kernel by acquiring the semaphore's
* wait_lock inside rwsem_is_locked(). The SPL worked around the race
* condition by acquiring the wait_lock before calling that function, but
* with the fix in place we must not do that.
*/
#define spl_rwsem_is_locked(rwsem) \
({ \
rwsem_is_locked(rwsem); \
})
#else
#define spl_rwsem_is_locked(rwsem) \
({ \
unsigned long _flags_; \
int _rc_; \
spl_rwsem_lock_irqsave(&rwsem->wait_lock, _flags_); \
_rc_ = rwsem_is_locked(rwsem); \
spl_rwsem_unlock_irqrestore(&rwsem->wait_lock, _flags_); \
_rc_; \
})
#endif /* RWSEM_IS_LOCKED_TAKES_WAIT_LOCK */
#endif /* _SPL_RWSEM_COMPAT_H */
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