mutex: add atomic_dec_and_mutex_lock(), fix

include/linux/mutex.h:136: warning: 'mutex_lock' declared inline after being called
 include/linux/mutex.h:136: warning: previous declaration of 'mutex_lock' was here

uninline it.

[ Impact: clean up and uninline, address compiler warning ]

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Eric Paris <eparis@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <200904292318.n3TNIsi6028340@imap1.linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/include/linux/mutex.h b/include/linux/mutex.h
index 93054fc..878cab4 100644 (file)
--- a/include/linux/mutex.h
+++ b/include/linux/mutex.h
@@ -150,28 +150,6 @@ extern int __must_check mutex_lock_killable(struct mutex *lock);
  */
 extern int mutex_trylock(struct mutex *lock);
 extern void mutex_unlock(struct mutex *lock);
-
-/**
- * atomic_dec_and_mutex_lock - return holding mutex if we dec to 0
- * @cnt: the atomic which we are to dec
- * @lock: the mutex to return holding if we dec to 0
- *
- * return true and hold lock if we dec to 0, return false otherwise
- */
-static inline int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock)
-{
-       /* dec if we can't possibly hit 0 */
-       if (atomic_add_unless(cnt, -1, 1))
-               return 0;
-       /* we might hit 0, so take the lock */
-       mutex_lock(lock);
-       if (!atomic_dec_and_test(cnt)) {
-               /* when we actually did the dec, we didn't hit 0 */
-               mutex_unlock(lock);
-               return 0;
-       }
-       /* we hit 0, and we hold the lock */
-       return 1;
-}
+extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock);
 
 #endif

diff --git a/kernel/mutex.c b/kernel/mutex.c
index 507cf2b..e2d25e9 100644 (file)
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -471,5 +471,28 @@ int __sched mutex_trylock(struct mutex *lock)
 
        return ret;
 }
-
 EXPORT_SYMBOL(mutex_trylock);
+
+/**
+ * atomic_dec_and_mutex_lock - return holding mutex if we dec to 0
+ * @cnt: the atomic which we are to dec
+ * @lock: the mutex to return holding if we dec to 0
+ *
+ * return true and hold lock if we dec to 0, return false otherwise
+ */
+int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock)
+{
+       /* dec if we can't possibly hit 0 */
+       if (atomic_add_unless(cnt, -1, 1))
+               return 0;
+       /* we might hit 0, so take the lock */
+       mutex_lock(lock);
+       if (!atomic_dec_and_test(cnt)) {
+               /* when we actually did the dec, we didn't hit 0 */
+               mutex_unlock(lock);
+               return 0;
+       }
+       /* we hit 0, and we hold the lock */
+       return 1;
+}
+EXPORT_SYMBOL(atomic_dec_and_mutex_lock);