Merge branch 'for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu

[sfrench/cifs-2.6.git] / lib / percpu-refcount.c

diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c
index 071a76c7bac079d421840ad4c708c5e66d02ea8c..4f6c6ebbbbdea8c311d30eda388b29c2f02893b6 100644 (file)
--- a/lib/percpu-refcount.c
+++ b/lib/percpu-refcount.c
@@ -70,11 +70,14 @@ int percpu_ref_init(struct percpu_ref *ref, percpu_ref_func_t *release,
                return -ENOMEM;
 
        ref->force_atomic = flags & PERCPU_REF_INIT_ATOMIC;
+       ref->allow_reinit = flags & PERCPU_REF_ALLOW_REINIT;
 
-       if (flags & (PERCPU_REF_INIT_ATOMIC | PERCPU_REF_INIT_DEAD))
+       if (flags & (PERCPU_REF_INIT_ATOMIC | PERCPU_REF_INIT_DEAD)) {
                ref->percpu_count_ptr |= __PERCPU_REF_ATOMIC;
-       else
+               ref->allow_reinit = true;
+       } else {
                start_count += PERCPU_COUNT_BIAS;
+       }
 
        if (flags & PERCPU_REF_INIT_DEAD)
                ref->percpu_count_ptr |= __PERCPU_REF_DEAD;
@@ -120,6 +123,9 @@ static void percpu_ref_call_confirm_rcu(struct rcu_head *rcu)
        ref->confirm_switch = NULL;
        wake_up_all(&percpu_ref_switch_waitq);
 
+       if (!ref->allow_reinit)
+               percpu_ref_exit(ref);
+
        /* drop ref from percpu_ref_switch_to_atomic() */
        percpu_ref_put(ref);
 }
@@ -195,6 +201,9 @@ static void __percpu_ref_switch_to_percpu(struct percpu_ref *ref)
        if (!(ref->percpu_count_ptr & __PERCPU_REF_ATOMIC))
                return;
 
+       if (WARN_ON_ONCE(!ref->allow_reinit))
+               return;
+
        atomic_long_add(PERCPU_COUNT_BIAS, &ref->count);
 
        /*