Revision 1c1e093cbf6d3a7576ba0bd10363362a1c5c74ee authored by Stefan Weinhuber on 12 May 2010, 07:32:11 UTC, committed by Martin Schwidefsky on 12 May 2010, 07:32:26 UTC
The various dasd_sleep_on functions use a global wait queue when
waiting for a cqr. The wait condition checks the status and devlist
fields of the cqr to determine if it is safe to continue. This
evaluation may return true, although the tasklet has not finished
processing of the cqr and the callback function has not been called
yet. When the callback is finally called, the data in the cqr may
already be invalid. The sleep_on wait condition needs a safe way to
determine if the tasklet has finished processing. Use the
callback_data field of the cqr to store a token, which is set by
the callback function itself.

Cc: <stable@kernel.org>
Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
1 parent cea0d76
Raw File
mutex.h
/*
 * Mutexes: blocking mutual exclusion locks
 *
 * started by Ingo Molnar:
 *
 *  Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
 *
 * This file contains mutex debugging related internal prototypes, for the
 * !CONFIG_DEBUG_MUTEXES case. Most of them are NOPs:
 */

#define spin_lock_mutex(lock, flags) \
		do { spin_lock(lock); (void)(flags); } while (0)
#define spin_unlock_mutex(lock, flags) \
		do { spin_unlock(lock); (void)(flags); } while (0)
#define mutex_remove_waiter(lock, waiter, ti) \
		__list_del((waiter)->list.prev, (waiter)->list.next)

#ifdef CONFIG_SMP
static inline void mutex_set_owner(struct mutex *lock)
{
	lock->owner = current_thread_info();
}

static inline void mutex_clear_owner(struct mutex *lock)
{
	lock->owner = NULL;
}
#else
static inline void mutex_set_owner(struct mutex *lock)
{
}

static inline void mutex_clear_owner(struct mutex *lock)
{
}
#endif

#define debug_mutex_wake_waiter(lock, waiter)		do { } while (0)
#define debug_mutex_free_waiter(waiter)			do { } while (0)
#define debug_mutex_add_waiter(lock, waiter, ti)	do { } while (0)
#define debug_mutex_unlock(lock)			do { } while (0)
#define debug_mutex_init(lock, name, key)		do { } while (0)

static inline void
debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
{
}
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