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author | David S. Miller <davem@davemloft.net> | 2010-01-22 22:45:46 -0800 |
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committer | David S. Miller <davem@davemloft.net> | 2010-01-22 22:45:46 -0800 |
commit | 6be325719b3e54624397e413efd4b33a997e55a3 (patch) | |
tree | 57f321a56794cab2222e179b16731e0d76a4a68a /lib/rwsem-spinlock.c | |
parent | 26d92f9276a56d55511a427fb70bd70886af647a (diff) | |
parent | 92dcffb916d309aa01778bf8963a6932e4014d07 (diff) | |
download | op-kernel-dev-6be325719b3e54624397e413efd4b33a997e55a3.zip op-kernel-dev-6be325719b3e54624397e413efd4b33a997e55a3.tar.gz |
Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Diffstat (limited to 'lib/rwsem-spinlock.c')
-rw-r--r-- | lib/rwsem-spinlock.c | 23 |
1 files changed, 14 insertions, 9 deletions
diff --git a/lib/rwsem-spinlock.c b/lib/rwsem-spinlock.c index 9df3ca5..ccf95bf 100644 --- a/lib/rwsem-spinlock.c +++ b/lib/rwsem-spinlock.c @@ -17,6 +17,19 @@ struct rwsem_waiter { #define RWSEM_WAITING_FOR_WRITE 0x00000002 }; +int rwsem_is_locked(struct rw_semaphore *sem) +{ + int ret = 1; + unsigned long flags; + + if (spin_trylock_irqsave(&sem->wait_lock, flags)) { + ret = (sem->activity != 0); + spin_unlock_irqrestore(&sem->wait_lock, flags); + } + return ret; +} +EXPORT_SYMBOL(rwsem_is_locked); + /* * initialise the semaphore */ @@ -34,6 +47,7 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name, spin_lock_init(&sem->wait_lock); INIT_LIST_HEAD(&sem->wait_list); } +EXPORT_SYMBOL(__init_rwsem); /* * handle the lock release when processes blocked on it that can now run @@ -305,12 +319,3 @@ void __downgrade_write(struct rw_semaphore *sem) spin_unlock_irqrestore(&sem->wait_lock, flags); } -EXPORT_SYMBOL(__init_rwsem); -EXPORT_SYMBOL(__down_read); -EXPORT_SYMBOL(__down_read_trylock); -EXPORT_SYMBOL(__down_write_nested); -EXPORT_SYMBOL(__down_write); -EXPORT_SYMBOL(__down_write_trylock); -EXPORT_SYMBOL(__up_read); -EXPORT_SYMBOL(__up_write); -EXPORT_SYMBOL(__downgrade_write); |