Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

[firefly-linux-kernel-4.4.55.git] / block / blk-core.c

diff --git a/block/blk-core.c b/block/blk-core.c
index dd134d834d589468fe1794c71a8325920ee5ac34..4b4dbdfbca89fe5769fd4b2f6826f305fca18e26 100644 (file)
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -2909,23 +2909,47 @@ static void queue_unplugged(struct request_queue *q, unsigned int depth,
 
 }
 
-static void flush_plug_callbacks(struct blk_plug *plug)
+static void flush_plug_callbacks(struct blk_plug *plug, bool from_schedule)
 {
        LIST_HEAD(callbacks);
 
-       if (list_empty(&plug->cb_list))
-               return;
-
-       list_splice_init(&plug->cb_list, &callbacks);
+       while (!list_empty(&plug->cb_list)) {
+               list_splice_init(&plug->cb_list, &callbacks);
 
-       while (!list_empty(&callbacks)) {
-               struct blk_plug_cb *cb = list_first_entry(&callbacks,
+               while (!list_empty(&callbacks)) {
+                       struct blk_plug_cb *cb = list_first_entry(&callbacks,
                                                          struct blk_plug_cb,
                                                          list);
-               list_del(&cb->list);
-               cb->callback(cb);
+                       list_del(&cb->list);
+                       cb->callback(cb, from_schedule);
+               }
+       }
+}
+
+struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug, void *data,
+                                     int size)
+{
+       struct blk_plug *plug = current->plug;
+       struct blk_plug_cb *cb;
+
+       if (!plug)
+               return NULL;
+
+       list_for_each_entry(cb, &plug->cb_list, list)
+               if (cb->callback == unplug && cb->data == data)
+                       return cb;
+
+       /* Not currently on the callback list */
+       BUG_ON(size < sizeof(*cb));
+       cb = kzalloc(size, GFP_ATOMIC);
+       if (cb) {
+               cb->data = data;
+               cb->callback = unplug;
+               list_add(&cb->list, &plug->cb_list);
        }
+       return cb;
 }
+EXPORT_SYMBOL(blk_check_plugged);
 
 void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
 {
@@ -2937,7 +2961,7 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
 
        BUG_ON(plug->magic != PLUG_MAGIC);
 
-       flush_plug_callbacks(plug);
+       flush_plug_callbacks(plug, from_schedule);
        if (list_empty(&plug->list))
                return;