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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2010-03-01 02:55:20 -0500
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2010-03-01 02:55:20 -0500
commit35858adbfca13678af99fb31618ef4428d6dedb0 (patch)
tree3336feaa61324486945816cb52c347733e7c0821 /lib/rwsem-spinlock.c
parent197d4db752e67160d79fed09968c2140376a80a3 (diff)
parent4b70858ba8d4537daf782defebe5f2ff80ccef2b (diff)
Merge branch 'next' into for-linus
Diffstat (limited to 'lib/rwsem-spinlock.c')
-rw-r--r--lib/rwsem-spinlock.c23
1 files changed, 14 insertions, 9 deletions
diff --git a/lib/rwsem-spinlock.c b/lib/rwsem-spinlock.c
index 9df3ca56db11..ccf95bff7984 100644
--- a/lib/rwsem-spinlock.c
+++ b/lib/rwsem-spinlock.c
@@ -17,6 +17,19 @@ struct rwsem_waiter {
17#define RWSEM_WAITING_FOR_WRITE 0x00000002 17#define RWSEM_WAITING_FOR_WRITE 0x00000002
18}; 18};
19 19
20int rwsem_is_locked(struct rw_semaphore *sem)
21{
22 int ret = 1;
23 unsigned long flags;
24
25 if (spin_trylock_irqsave(&sem->wait_lock, flags)) {
26 ret = (sem->activity != 0);
27 spin_unlock_irqrestore(&sem->wait_lock, flags);
28 }
29 return ret;
30}
31EXPORT_SYMBOL(rwsem_is_locked);
32
20/* 33/*
21 * initialise the semaphore 34 * initialise the semaphore
22 */ 35 */
@@ -34,6 +47,7 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name,
34 spin_lock_init(&sem->wait_lock); 47 spin_lock_init(&sem->wait_lock);
35 INIT_LIST_HEAD(&sem->wait_list); 48 INIT_LIST_HEAD(&sem->wait_list);
36} 49}
50EXPORT_SYMBOL(__init_rwsem);
37 51
38/* 52/*
39 * handle the lock release when processes blocked on it that can now run 53 * handle the lock release when processes blocked on it that can now run
@@ -305,12 +319,3 @@ void __downgrade_write(struct rw_semaphore *sem)
305 spin_unlock_irqrestore(&sem->wait_lock, flags); 319 spin_unlock_irqrestore(&sem->wait_lock, flags);
306} 320}
307 321
308EXPORT_SYMBOL(__init_rwsem);
309EXPORT_SYMBOL(__down_read);
310EXPORT_SYMBOL(__down_read_trylock);
311EXPORT_SYMBOL(__down_write_nested);
312EXPORT_SYMBOL(__down_write);
313EXPORT_SYMBOL(__down_write_trylock);
314EXPORT_SYMBOL(__up_read);
315EXPORT_SYMBOL(__up_write);
316EXPORT_SYMBOL(__downgrade_write);