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| author | Peter Zijlstra <peterz@infradead.org> | 2016-11-14 18:03:11 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-01-18 10:03:29 +0100 |
| commit | 0a13cd1a05e7a549259d4f803d2ec2efda07ed7c (patch) | |
| tree | 8d8799d8a46d827a689e9939d472654b307e16c8 | |
| parent | 23b19ec3377924eb8f303880102e056e9214ba72 (diff) | |
| download | linux-0a13cd1a05e7a549259d4f803d2ec2efda07ed7c.tar.bz2 | |
locking/atomic, kref: Implement kref_put_lock()
Because home-rolling your own is _awesome_, stop doing it. Provide
kref_put_lock(), just like kref_put_mutex() but for a spinlock.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | include/linux/kref.h | 22 | ||||
| -rw-r--r-- | net/sunrpc/svcauth.c | 15 |
2 files changed, 26 insertions, 11 deletions
diff --git a/include/linux/kref.h b/include/linux/kref.h index 31c49a64cdf9..9db9685fed84 100644 --- a/include/linux/kref.h +++ b/include/linux/kref.h @@ -19,6 +19,7 @@ #include <linux/atomic.h> #include <linux/kernel.h> #include <linux/mutex.h> +#include <linux/spinlock.h> struct kref { atomic_t refcount; @@ -86,12 +87,21 @@ static inline int kref_put_mutex(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; - } + + if (atomic_dec_and_mutex_lock(&kref->refcount, lock)) { + release(kref); + return 1; + } + return 0; +} + +static inline int kref_put_lock(struct kref *kref, + void (*release)(struct kref *kref), + spinlock_t *lock) +{ + WARN_ON(release == NULL); + + if (atomic_dec_and_lock(&kref->refcount, lock)) { release(kref); return 1; } diff --git a/net/sunrpc/svcauth.c b/net/sunrpc/svcauth.c index e112da8005b5..bb8db3cb8032 100644 --- a/net/sunrpc/svcauth.c +++ b/net/sunrpc/svcauth.c @@ -126,13 +126,18 @@ EXPORT_SYMBOL_GPL(svc_auth_unregister); static struct hlist_head auth_domain_table[DN_HASHMAX]; static DEFINE_SPINLOCK(auth_domain_lock); +static void auth_domain_release(struct kref *kref) +{ + struct auth_domain *dom = container_of(kref, struct auth_domain, ref); + + hlist_del(&dom->hash); + dom->flavour->domain_release(dom); + spin_unlock(&auth_domain_lock); +} + void auth_domain_put(struct auth_domain *dom) { - if (atomic_dec_and_lock(&dom->ref.refcount, &auth_domain_lock)) { - hlist_del(&dom->hash); - dom->flavour->domain_release(dom); - spin_unlock(&auth_domain_lock); - } + kref_put_lock(&dom->ref, auth_domain_release, &auth_domain_lock); } EXPORT_SYMBOL_GPL(auth_domain_put); |