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-rw-r--r--include/linux/percpu-rwsem.h6
-rw-r--r--include/linux/rwsem.h6
2 files changed, 11 insertions, 1 deletions
diff --git a/include/linux/percpu-rwsem.h b/include/linux/percpu-rwsem.h
index b1f37a89e368..79b99d653e03 100644
--- a/include/linux/percpu-rwsem.h
+++ b/include/linux/percpu-rwsem.h
@@ -133,7 +133,7 @@ static inline void percpu_rwsem_release(struct percpu_rw_semaphore *sem,
lock_release(&sem->rw_sem.dep_map, 1, ip);
#ifdef CONFIG_RWSEM_SPIN_ON_OWNER
if (!read)
- sem->rw_sem.owner = NULL;
+ sem->rw_sem.owner = RWSEM_OWNER_UNKNOWN;
#endif
}
@@ -141,6 +141,10 @@ static inline void percpu_rwsem_acquire(struct percpu_rw_semaphore *sem,
bool read, unsigned long ip)
{
lock_acquire(&sem->rw_sem.dep_map, 0, 1, read, 1, NULL, ip);
+#ifdef CONFIG_RWSEM_SPIN_ON_OWNER
+ if (!read)
+ sem->rw_sem.owner = current;
+#endif
}
#endif
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h
index 56707d5ff6ad..ab93b6eae696 100644
--- a/include/linux/rwsem.h
+++ b/include/linux/rwsem.h
@@ -44,6 +44,12 @@ struct rw_semaphore {
#endif
};
+/*
+ * Setting bit 0 of the owner field with other non-zero bits will indicate
+ * that the rwsem is writer-owned with an unknown owner.
+ */
+#define RWSEM_OWNER_UNKNOWN ((struct task_struct *)-1L)
+
extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_down_read_failed_killable(struct rw_semaphore *sem);
extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem);