111 lines
2.8 KiB
C
111 lines
2.8 KiB
C
/*-
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* Copyright (c) 2010 Isilon Systems, Inc.
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* Copyright (c) 2010 iX Systems, Inc.
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* Copyright (c) 2010 Panasas, Inc.
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* Copyright (c) 2013-2015 Mellanox Technologies, Ltd.
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* Copyright (c) 2013 François Tigeot
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice unmodified, this list of conditions, and the following
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* disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#ifndef _LINUX_KREF_H_
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#define _LINUX_KREF_H_
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#include <sys/types.h>
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#include <sys/refcount.h>
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#include <linux/compiler.h>
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#include <linux/kernel.h>
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#include <linux/mutex.h>
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#include <asm/atomic.h>
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struct kref {
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atomic_t refcount;
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};
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static inline void
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kref_init(struct kref *kref)
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{
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refcount_init(&kref->refcount.counter, 1);
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}
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static inline void
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kref_get(struct kref *kref)
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{
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refcount_acquire(&kref->refcount.counter);
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}
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static inline int
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kref_put(struct kref *kref, void (*rel)(struct kref *kref))
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{
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if (refcount_release(&kref->refcount.counter)) {
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rel(kref);
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return 1;
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}
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return 0;
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}
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static inline int
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kref_sub(struct kref *kref, unsigned int count,
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void (*rel)(struct kref *kref))
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{
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while (count--) {
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if (refcount_release(&kref->refcount.counter)) {
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rel(kref);
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return 1;
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}
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}
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return 0;
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}
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static inline int __must_check
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kref_get_unless_zero(struct kref *kref)
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{
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return atomic_add_unless(&kref->refcount, 1, 0);
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}
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static inline int kref_put_mutex(struct kref *kref,
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void (*release)(struct kref *kref), struct mutex *lock)
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{
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WARN_ON(release == NULL);
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if (unlikely(!atomic_add_unless(&kref->refcount, -1, 1))) {
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mutex_lock(lock);
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if (unlikely(!atomic_dec_and_test(&kref->refcount))) {
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mutex_unlock(lock);
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return 0;
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}
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release(kref);
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return 1;
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}
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return 0;
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}
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#endif /* _LINUX_KREF_H_ */
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