misc: Fix allocation 'borrowed' by vhost_net

[safe/jmp/linux-2.6] / lib / rwsem.c

diff --git a/lib/rwsem.c b/lib/rwsem.c
index 62fa4eb..ceba8e2 100644 (file)
--- a/lib/rwsem.c
+++ b/lib/rwsem.c
@@ -8,6 +8,26 @@
 #include <linux/init.h>
 #include <linux/module.h>
 
+/*
+ * Initialize an rwsem:
+ */
+void __init_rwsem(struct rw_semaphore *sem, const char *name,
+                 struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+       /*
+        * Make sure we are not reinitializing a held semaphore:
+        */
+       debug_check_no_locks_freed((void *)sem, sizeof(*sem));
+       lockdep_init_map(&sem->dep_map, name, key, 0);
+#endif
+       sem->count = RWSEM_UNLOCKED_VALUE;
+       spin_lock_init(&sem->wait_lock);
+       INIT_LIST_HEAD(&sem->wait_list);
+}
+
+EXPORT_SYMBOL(__init_rwsem);
+
 struct rwsem_waiter {
        struct list_head list;
        struct task_struct *task;
@@ -16,17 +36,6 @@ struct rwsem_waiter {
 #define RWSEM_WAITING_FOR_WRITE        0x00000002
 };
 
-#if RWSEM_DEBUG
-#undef rwsemtrace
-void rwsemtrace(struct rw_semaphore *sem, const char *str)
-{
-       printk("sem=%p\n", sem);
-       printk("(sem)=%08lx\n", sem->count);
-       if (sem->debug)
-               printk("[%d] %s({%08lx})\n", current->pid, str, sem->count);
-}
-#endif
-
 /*
  * handle the lock release when processes blocked on it that can now run
  * - if we come here from up_xxxx(), then:
@@ -45,8 +54,6 @@ __rwsem_do_wake(struct rw_semaphore *sem, int downgrading)
        struct list_head *next;
        signed long oldcount, woken, loop;
 
-       rwsemtrace(sem, "Entering __rwsem_do_wake");
-
        if (downgrading)
                goto dont_wake_writers;
 
@@ -127,12 +134,12 @@ __rwsem_do_wake(struct rw_semaphore *sem, int downgrading)
        next->prev = &sem->wait_list;
 
  out:
-       rwsemtrace(sem, "Leaving __rwsem_do_wake");
        return sem;
 
-       /* undo the change to count, but check for a transition 1->0 */
+       /* undo the change to the active count, but check for a transition
+        * 1->0 */
  undo:
-       if (rwsem_atomic_update(-RWSEM_ACTIVE_BIAS, sem) != 0)
+       if (rwsem_atomic_update(-RWSEM_ACTIVE_BIAS, sem) & RWSEM_ACTIVE_MASK)
                goto out;
        goto try_again;
 }
@@ -140,7 +147,7 @@ __rwsem_do_wake(struct rw_semaphore *sem, int downgrading)
 /*
  * wait for a lock to be granted
  */
-static inline struct rw_semaphore *
+static struct rw_semaphore __sched *
 rwsem_down_failed_common(struct rw_semaphore *sem,
                        struct rwsem_waiter *waiter, signed long adjustment)
 {
@@ -181,35 +188,28 @@ rwsem_down_failed_common(struct rw_semaphore *sem,
 /*
  * wait for the read lock to be granted
  */
-struct rw_semaphore fastcall __sched *
+asmregparm struct rw_semaphore __sched *
 rwsem_down_read_failed(struct rw_semaphore *sem)
 {
        struct rwsem_waiter waiter;
 
-       rwsemtrace(sem, "Entering rwsem_down_read_failed");
-
        waiter.flags = RWSEM_WAITING_FOR_READ;
        rwsem_down_failed_common(sem, &waiter,
                                RWSEM_WAITING_BIAS - RWSEM_ACTIVE_BIAS);
-
-       rwsemtrace(sem, "Leaving rwsem_down_read_failed");
        return sem;
 }
 
 /*
  * wait for the write lock to be granted
  */
-struct rw_semaphore fastcall __sched *
+asmregparm struct rw_semaphore __sched *
 rwsem_down_write_failed(struct rw_semaphore *sem)
 {
        struct rwsem_waiter waiter;
 
-       rwsemtrace(sem, "Entering rwsem_down_write_failed");
-
        waiter.flags = RWSEM_WAITING_FOR_WRITE;
        rwsem_down_failed_common(sem, &waiter, -RWSEM_ACTIVE_BIAS);
 
-       rwsemtrace(sem, "Leaving rwsem_down_write_failed");
        return sem;
 }
 
@@ -217,12 +217,10 @@ rwsem_down_write_failed(struct rw_semaphore *sem)
  * handle waking up a waiter on the semaphore
  * - up_read/up_write has decremented the active part of count if we come here
  */
-struct rw_semaphore fastcall *rwsem_wake(struct rw_semaphore *sem)
+asmregparm struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem)
 {
        unsigned long flags;
 
-       rwsemtrace(sem, "Entering rwsem_wake");
-
        spin_lock_irqsave(&sem->wait_lock, flags);
 
        /* do nothing if list empty */
@@ -231,8 +229,6 @@ struct rw_semaphore fastcall *rwsem_wake(struct rw_semaphore *sem)
 
        spin_unlock_irqrestore(&sem->wait_lock, flags);
 
-       rwsemtrace(sem, "Leaving rwsem_wake");
-
        return sem;
 }
 
@@ -241,12 +237,10 @@ struct rw_semaphore fastcall *rwsem_wake(struct rw_semaphore *sem)
  * - caller incremented waiting part of count and discovered it still negative
  * - just wake up any readers at the front of the queue
  */
-struct rw_semaphore fastcall *rwsem_downgrade_wake(struct rw_semaphore *sem)
+asmregparm struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem)
 {
        unsigned long flags;
 
-       rwsemtrace(sem, "Entering rwsem_downgrade_wake");
-
        spin_lock_irqsave(&sem->wait_lock, flags);
 
        /* do nothing if list empty */
@@ -255,7 +249,6 @@ struct rw_semaphore fastcall *rwsem_downgrade_wake(struct rw_semaphore *sem)
 
        spin_unlock_irqrestore(&sem->wait_lock, flags);
 
-       rwsemtrace(sem, "Leaving rwsem_downgrade_wake");
        return sem;
 }
 
@@ -263,6 +256,3 @@ EXPORT_SYMBOL(rwsem_down_read_failed);
 EXPORT_SYMBOL(rwsem_down_write_failed);
 EXPORT_SYMBOL(rwsem_wake);
 EXPORT_SYMBOL(rwsem_downgrade_wake);
-#if RWSEM_DEBUG
-EXPORT_SYMBOL(rwsemtrace);
-#endif