diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2012-08-17 20:10:46 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2012-08-22 10:24:41 -0400 |
| commit | 8ad5db8a8ddbe3bd33078863a027011e28f1f4ee (patch) | |
| tree | e54d9b3a0f6dba580dec882046b99e576c33387c | |
| parent | 934ad4c235f87dcb9206abdfa22922358999afab (diff) | |
introduce kref_put_mutex()
equivalent of
mutex_lock(mutex);
if (!kref_put(kref, release))
mutex_unlock(mutex);
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | include/linux/kref.h | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/include/linux/kref.h b/include/linux/kref.h index 9c07dcebded7..65af6887872f 100644 --- a/include/linux/kref.h +++ b/include/linux/kref.h @@ -18,6 +18,7 @@ #include <linux/bug.h> #include <linux/atomic.h> #include <linux/kernel.h> +#include <linux/mutex.h> struct kref { atomic_t refcount; @@ -93,4 +94,21 @@ static inline int kref_put(struct kref *kref, void (*release)(struct kref *kref) { return kref_sub(kref, 1, release); } + +static inline int kref_put_mutex(struct kref *kref, + void (*release)(struct kref *kref), + struct mutex *lock) +{ + WARN_ON(release == NULL); + if (unlikely(!atomic_add_unless(&kref->refcount, -1, 1))) { + mutex_lock(lock); + if (unlikely(!atomic_dec_and_test(&kref->refcount))) { + mutex_unlock(lock); + return 0; + } + release(kref); + return 1; + } + return 0; +} #endif /* _KREF_H_ */ |