block: add end_queued_request() and end_dequeued_request() helpers
We can use this helper in the elevator core for BLKPREP_KILL, and it'll
also be useful for the empty barrier patch.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 0fa5d3d..8904f8b 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -3630,15 +3630,83 @@
EXPORT_SYMBOL(end_that_request_last);
-void end_request(struct request *req, int uptodate)
+static inline void __end_request(struct request *rq, int uptodate,
+ unsigned int nr_bytes, int dequeue)
{
- if (!end_that_request_first(req, uptodate, req->hard_cur_sectors)) {
- add_disk_randomness(req->rq_disk);
- blkdev_dequeue_request(req);
- end_that_request_last(req, uptodate);
+ if (!end_that_request_chunk(rq, uptodate, nr_bytes)) {
+ if (dequeue)
+ blkdev_dequeue_request(rq);
+ add_disk_randomness(rq->rq_disk);
+ end_that_request_last(rq, uptodate);
}
}
+static unsigned int rq_byte_size(struct request *rq)
+{
+ if (blk_fs_request(rq))
+ return rq->hard_nr_sectors << 9;
+
+ return rq->data_len;
+}
+
+/**
+ * end_queued_request - end all I/O on a queued request
+ * @rq: the request being processed
+ * @uptodate: error value or 0/1 uptodate flag
+ *
+ * Description:
+ * Ends all I/O on a request, and removes it from the block layer queues.
+ * Not suitable for normal IO completion, unless the driver still has
+ * the request attached to the block layer.
+ *
+ **/
+void end_queued_request(struct request *rq, int uptodate)
+{
+ __end_request(rq, uptodate, rq_byte_size(rq), 1);
+}
+EXPORT_SYMBOL(end_queued_request);
+
+/**
+ * end_dequeued_request - end all I/O on a dequeued request
+ * @rq: the request being processed
+ * @uptodate: error value or 0/1 uptodate flag
+ *
+ * Description:
+ * Ends all I/O on a request. The request must already have been
+ * dequeued using blkdev_dequeue_request(), as is normally the case
+ * for most drivers.
+ *
+ **/
+void end_dequeued_request(struct request *rq, int uptodate)
+{
+ __end_request(rq, uptodate, rq_byte_size(rq), 0);
+}
+EXPORT_SYMBOL(end_dequeued_request);
+
+
+/**
+ * end_request - end I/O on the current segment of the request
+ * @rq: the request being processed
+ * @uptodate: error value or 0/1 uptodate flag
+ *
+ * Description:
+ * Ends I/O on the current segment of a request. If that is the only
+ * remaining segment, the request is also completed and freed.
+ *
+ * This is a remnant of how older block drivers handled IO completions.
+ * Modern drivers typically end IO on the full request in one go, unless
+ * they have a residual value to account for. For that case this function
+ * isn't really useful, unless the residual just happens to be the
+ * full current segment. In other words, don't use this function in new
+ * code. Either use end_request_completely(), or the
+ * end_that_request_chunk() (along with end_that_request_last()) for
+ * partial completions.
+ *
+ **/
+void end_request(struct request *req, int uptodate)
+{
+ __end_request(req, uptodate, req->hard_cur_sectors << 9, 1);
+}
EXPORT_SYMBOL(end_request);
static void blk_rq_bio_prep(struct request_queue *q, struct request *rq,