diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/percpu-refcount.c | 28 |
1 files changed, 26 insertions, 2 deletions
diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c index 9f96fa7bc000..de10b8c0bff6 100644 --- a/lib/percpu-refcount.c +++ b/lib/percpu-refcount.c @@ -356,11 +356,35 @@ EXPORT_SYMBOL_GPL(percpu_ref_kill_and_confirm); */ void percpu_ref_reinit(struct percpu_ref *ref) { + WARN_ON_ONCE(!percpu_ref_is_zero(ref)); + + percpu_ref_resurrect(ref); +} +EXPORT_SYMBOL_GPL(percpu_ref_reinit); + +/** + * percpu_ref_resurrect - modify a percpu refcount from dead to live + * @ref: perpcu_ref to resurrect + * + * Modify @ref so that it's in the same state as before percpu_ref_kill() was + * called. @ref must be dead but must not yet have exited. + * + * If @ref->release() frees @ref then the caller is responsible for + * guaranteeing that @ref->release() does not get called while this + * function is in progress. + * + * Note that percpu_ref_tryget[_live]() are safe to perform on @ref while + * this function is in progress. + */ +void percpu_ref_resurrect(struct percpu_ref *ref) +{ + unsigned long __percpu *percpu_count; unsigned long flags; spin_lock_irqsave(&percpu_ref_switch_lock, flags); - WARN_ON_ONCE(!percpu_ref_is_zero(ref)); + WARN_ON_ONCE(!(ref->percpu_count_ptr & __PERCPU_REF_DEAD)); + WARN_ON_ONCE(__ref_is_percpu(ref, &percpu_count)); ref->percpu_count_ptr &= ~__PERCPU_REF_DEAD; percpu_ref_get(ref); @@ -368,4 +392,4 @@ void percpu_ref_reinit(struct percpu_ref *ref) spin_unlock_irqrestore(&percpu_ref_switch_lock, flags); } -EXPORT_SYMBOL_GPL(percpu_ref_reinit); +EXPORT_SYMBOL_GPL(percpu_ref_resurrect); |