2 files changed, 34 insertions, 0 deletions

diff --git a/Documentation/slow-work.txt b/Documentation/slow-work.txt
index f120238e70fe..0169c9d9dd16 100644
--- a/Documentation/slow-work.txt
+++ b/Documentation/slow-work.txt
@@ -144,6 +144,21 @@ from being taken away before it completes.  module should almost certainly be
 THIS_MODULE.
 
 
+================
+HELPER FUNCTIONS
+================
+
+The slow-work facility provides a function by which it can be determined
+whether or not an item is queued for later execution:
+
+        bool queued = slow_work_is_queued(struct slow_work *work);
+
+If it returns false, then the item is not on the queue (it may be executing
+with a requeue pending).  This can be used to work out whether an item on which
+another depends is on the queue, thus allowing a dependent item to be queued
+after it.
+
+
 ===============
 ITEM OPERATIONS
 ===============
diff --git a/include/linux/slow-work.h b/include/linux/slow-work.h
index f41485145ed1..bfd3ab4c8898 100644
--- a/include/linux/slow-work.h
+++ b/include/linux/slow-work.h
@@ -120,6 +120,25 @@ static inline void vslow_work_init(struct slow_work *work,
         INIT_LIST_HEAD(&work->link);
 }
 
+/**
+ * slow_work_is_queued - Determine if a slow work item is on the work queue
+ * work: The work item to test
+ *
+ * Determine if the specified slow-work item is on the work queue.  This
+ * returns true if it is actually on the queue.
+ *
+ * If the item is executing and has been marked for requeue when execution
+ * finishes, then false will be returned.
+ *
+ * Anyone wishing to wait for completion of execution can wait on the
+ * SLOW_WORK_EXECUTING bit.
+ */
+static inline bool slow_work_is_queued(struct slow_work *work)
+{
+        unsigned long flags = work->flags;
+        return flags & SLOW_WORK_PENDING && !(flags & SLOW_WORK_EXECUTING);
+}
+
 extern int slow_work_enqueue(struct slow_work *work);
 extern void slow_work_cancel(struct slow_work *work);
 extern int slow_work_register_user(struct module *owner);