linux-master/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 int lockref_get_not_zero(struct lockref *lockref)
73 	spin_lock(&lockref->lock);
75 	if (lockref->count > 0) {
76 		lockref->count++;
79 	spin_unlock(&lockref->lock);
86  * @lockref: pointer to lockref structure
89 int lockref_put_not_zero(struct lockref *lockref)
101 	spin_lock(&lockref->lock);
103 	if (lockref->count > 1) {
104 		lockref->count--;
107 	spin_unlock(&lockref->lock);
114  * @lockref: pointer to lockref structure
117  * If the lockref was dead or locked, return an error.
119 int lockref_put_return(struct lockref *lockref)
134  * @lockref: pointer to lockref structure
137 int lockref_put_or_lock(struct lockref *lockref)
147 	spin_lock(&lockref->lock);
148 	if (lockref->count <= 1)
150 	lockref->count--;
151 	spin_unlock(&lockref->lock);
157  * lockref_mark_dead - mark lockref dead
158  * @lockref: pointer to lockref structure
160 void lockref_mark_dead(struct lockref *lockref)
162 	assert_spin_locked(&lockref->lock);
163 	lockref->count = -128;
169  * @lockref: pointer to lockref structure
170  * Return: 1 if count updated successfully or 0 if lockref was dead
172 int lockref_get_not_dead(struct lockref *lockref)
184 	spin_lock(&lockref->lock);
186 	if (lockref->count >= 0) {
187 		lockref->count++;
190 	spin_unlock(&lockref->lock);