summaryrefslogtreecommitdiffstats
path: root/include/linux/rwsem.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/linux/rwsem.h')
-rw-r--r--include/linux/rwsem.h6
1 files changed, 6 insertions, 0 deletions
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);
OpenPOWER on IntegriCloud