linux/lib/lockref.c

3 #include <linux/lockref.h>
13 	struct lockref old;							\
15 	old.lock_count = READ_ONCE(lockref->lock_count);			\
17 		struct lockref new = old;					\
19 		if (likely(try_cmpxchg64_relaxed(&lockref->lock_count,		\
37  * @lockref: pointer to lockref structure
42 void lockref_get(struct lockref *lockref)
50 	spin_lock(&lockref->lock);
51 	lockref->count++;
52 	spin_unlock(&lockref->lock);
58  * @lockref: pointer to lockref structure
61 bool lockref_get_not_zero(struct lockref *lockref)
73 	spin_lock(&lockref->lock);
74 	if (lockref->count > 0) {
75 		lockref->count++;
78 	spin_unlock(&lockref->lock);
85  * @lockref: pointer to lockref structure
88  * If the lockref was dead or locked, return -1.
90 int lockref_put_return(struct lockref *lockref)
105  * @lockref: pointer to lockref structure
108 bool lockref_put_or_lock(struct lockref *lockref)
118 	spin_lock(&lockref->lock);
119 	if (lockref->count <= 1)
121 	lockref->count--;
122 	spin_unlock(&lockref->lock);
128  * lockref_mark_dead - mark lockref dead
129  * @lockref: pointer to lockref structure
131 void lockref_mark_dead(struct lockref *lockref)
133 	assert_spin_locked(&lockref->lock);
134 	lockref->count = -128;
140  * @lockref: pointer to lockref structure
141  * Return: 1 if count updated successfully or 0 if lockref was dead
143 bool lockref_get_not_dead(struct lockref *lockref)
155 	spin_lock(&lockref->lock);
156 	if (lockref->count >= 0) {
157 		lockref->count++;
160 	spin_unlock(&lockref->lock);