When iterating a list, a particular request may need to be moved for
special handling. Provide a helper function to achieve that so drivers
don't need to reimplement rqlist manipulation.
Signed-off-by: Keith Busch <kbusch@xxxxxxxxxx>
---
include/linux/blk-mq.h | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 550996cf419c..0efa25abcc1c 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -216,6 +216,25 @@ static inline unsigned short req_get_ioprio(struct request *req)
#define rq_dma_dir(rq) \
(op_is_write(req_op(rq)) ? DMA_TO_DEVICE : DMA_FROM_DEVICE)
+/**
+ * rq_list_move() - move a struct request from one list to another
+ * @src: The source list @rq is currently in
+ * @dst: The destination list that @rq will be appended to
+ * @rq: The request to move
+ * @prv: The request preceding @rq in @src (NULL if @rq is the head)
+ * @nxt: The request following @rq in @src (NULL if @rq is the tail)
+ */
+static void inline rq_list_move(struct request **src, struct request **dst,
+ struct request *rq, struct request *prv,
+ struct request *nxt)
+{
+ if (prv)
+ prv->rq_next = nxt;
+ else
+ *src = nxt;
+ rq_list_add(dst, rq);
+}
+
enum blk_eh_timer_return {
BLK_EH_DONE, /* drivers has completed the command */
BLK_EH_RESET_TIMER, /* reset timer and try again */
--
2.25.4
