EXPORT_SYMBOL(lockref_get);
/**
- * lockref_get_not_zero - Increments count unless the count is 0
+ * lockref_get_not_zero - Increments count unless the count is 0 or dead
* @lockref: pointer to lockref structure
* Return: 1 if count updated successfully or 0 if count was zero
*/
CMPXCHG_LOOP(
new.count++;
- if (!old.count)
+ if (old.count <= 0)
return 0;
,
return 1;
spin_lock(&lockref->lock);
retval = 0;
- if (lockref->count) {
+ if (lockref->count > 0) {
lockref->count++;
retval = 1;
}
EXPORT_SYMBOL(lockref_get_not_zero);
/**
- * lockref_get_or_lock - Increments count unless the count is 0
+ * lockref_get_or_lock - Increments count unless the count is 0 or dead
* @lockref: pointer to lockref structure
* Return: 1 if count updated successfully or 0 if count was zero
* and we got the lock instead.
{
CMPXCHG_LOOP(
new.count++;
- if (!old.count)
+ if (old.count <= 0)
break;
,
return 1;
);
spin_lock(&lockref->lock);
- if (!lockref->count)
+ if (lockref->count <= 0)
return 0;
lockref->count++;
spin_unlock(&lockref->lock);
}
EXPORT_SYMBOL(lockref_get_or_lock);
+/**
+ * lockref_put_return - Decrement reference count if possible
+ * @lockref: pointer to lockref structure
+ *
+ * Decrement the reference count and return the new value.
+ * If the lockref was dead or locked, return an error.
+ */
+int lockref_put_return(struct lockref *lockref)
+{
+ CMPXCHG_LOOP(
+ new.count--;
+ if (old.count <= 0)
+ return -1;
+ ,
+ return new.count;
+ );
+ return -1;
+}
+EXPORT_SYMBOL(lockref_put_return);
+
/**
* lockref_put_or_lock - decrements count unless count <= 1 before decrement
* @lockref: pointer to lockref structure
CMPXCHG_LOOP(
new.count++;
- if ((int)old.count < 0)
+ if (old.count < 0)
return 0;
,
return 1;
spin_lock(&lockref->lock);
retval = 0;
- if ((int) lockref->count >= 0) {
+ if (lockref->count >= 0) {
lockref->count++;
retval = 1;
}