waterDataFluctuationCorrelation analysisOfLiquidLevelDataOperation.c 薛梅子 commit at 2021-02-22

waterDataFluctuationCorrelation/fluctuationCorrelationOfSprayEnd/analysisOfLiquidLevelDataOperation.c

@@ -13,3 +13,64 @@
  * blk_queue_find_tag - find a request by its tag and queue
  * @q:	 The request queue for the device
  * @tag: The tag of the request
+ *
+ * Notes:
+ *    Should be used when a device returns a tag and you want to match
+ *    it with a request.
+ *
+ *    no locks need be held.
+ **/
+struct request *blk_queue_find_tag(struct request_queue *q, int tag)
+{
+	return blk_map_queue_find_tag(q->queue_tags, tag);
+}
+EXPORT_SYMBOL(blk_queue_find_tag);
+
+/**
+ * __blk_free_tags - release a given set of tag maintenance info
+ * @bqt:	the tag map to free
+ *
+ * Tries to free the specified @bqt.  Returns true if it was
+ * actually freed and false if there are still references using it
+ */
+static int __blk_free_tags(struct blk_queue_tag *bqt)
+{
+	int retval;
+
+	retval = atomic_dec_and_test(&bqt->refcnt);
+	if (retval) {
+		BUG_ON(find_first_bit(bqt->tag_map, bqt->max_depth) <
+							bqt->max_depth);
+
+		kfree(bqt->tag_index);
+		bqt->tag_index = NULL;
+
+		kfree(bqt->tag_map);
+		bqt->tag_map = NULL;
+
+		kfree(bqt);
+	}
+
+	return retval;
+}
+
+/**
+ * __blk_queue_free_tags - release tag maintenance info
+ * @q:  the request queue for the device
+ *
+ *  Notes:
+ *    blk_cleanup_queue() will take care of calling this function, if tagging
+ *    has been used. So there's no need to call this directly.
+ **/
+void __blk_queue_free_tags(struct request_queue *q)
+{
+	struct blk_queue_tag *bqt = q->queue_tags;
+
+	if (!bqt)
+		return;
+
+	__blk_free_tags(bqt);
+
+	q->queue_tags = NULL;
+	queue_flag_clear_unlocked(QUEUE_FLAG_QUEUED, q);
+}