block: add completion handler for fast path

The batched completions only deal with non-partial requests anyway,
and it doesn't deal with any requests that have errors. Add a completion
handler that assumes it's a full request and that it's all being ended
successfully.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 103c0f5..75154cc 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -709,6 +709,47 @@ static void blk_print_req_error(struct request *req, blk_status_t status)
                IOPRIO_PRIO_CLASS(req->ioprio));
 }
 
+/*
+ * Fully end IO on a request. Does not support partial completions, or
+ * errors.
+ */
+static void blk_complete_request(struct request *req)
+{
+       const bool is_flush = (req->rq_flags & RQF_FLUSH_SEQ) != 0;
+       int total_bytes = blk_rq_bytes(req);
+       struct bio *bio = req->bio;
+
+       trace_block_rq_complete(req, BLK_STS_OK, total_bytes);
+
+       if (!bio)
+               return;
+
+#ifdef CONFIG_BLK_DEV_INTEGRITY
+       if (blk_integrity_rq(req) && req_op(req) == REQ_OP_READ)
+               req->q->integrity.profile->complete_fn(req, total_bytes);
+#endif
+
+       blk_account_io_completion(req, total_bytes);
+
+       do {
+               struct bio *next = bio->bi_next;
+
+               /* Completion has already been traced */
+               bio_clear_flag(bio, BIO_TRACE_COMPLETION);
+               if (!is_flush)
+                       bio_endio(bio);
+               bio = next;
+       } while (bio);
+
+       /*
+        * Reset counters so that the request stacking driver
+        * can find how many bytes remain in the request
+        * later.
+        */
+       req->bio = NULL;
+       req->__data_len = 0;
+}
+
 /**
  * blk_update_request - Complete multiple bytes without completing the request
  * @req:      the request being processed
@@ -922,7 +963,7 @@ void blk_mq_end_request_batch(struct io_comp_batch *iob)
                prefetch(rq->bio);
                prefetch(rq->rq_next);
 
-               blk_update_request(rq, BLK_STS_OK, blk_rq_bytes(rq));
+               blk_complete_request(rq);
                if (iob->need_ts)
                        __blk_mq_end_request_acct(rq, now);