waterDataFluctuationCorrelation preliminaryDataProcessing.c 张婷 commit at 2021-03-04

waterDataFluctuationCorrelation/monitoringDataProcessing/preliminaryDataProcessing.c

@@ -2229,3 +2229,198 @@ struct request *blk_fetch_request(struct request_queue *q)
 
 	rq = blk_peek_request(q);
 	if (rq)
+		blk_start_request(rq);
+	return rq;
+}
+EXPORT_SYMBOL(blk_fetch_request);
+
+/**
+ * blk_update_request - Special helper function for request stacking drivers
+ * @req:      the request being processed
+ * @error:    %0 for success, < %0 for error
+ * @nr_bytes: number of bytes to complete @req
+ *
+ * Description:
+ *     Ends I/O on a number of bytes attached to @req, but doesn't complete
+ *     the request structure even if @req doesn't have leftover.
+ *     If @req has leftover, sets it up for the next range of segments.
+ *
+ *     This special helper function is only for request stacking drivers
+ *     (e.g. request-based dm) so that they can handle partial completion.
+ *     Actual device drivers should use blk_end_request instead.
+ *
+ *     Passing the result of blk_rq_bytes() as @nr_bytes guarantees
+ *     %false return from this function.
+ *
+ * Return:
+ *     %false - this request doesn't have any more data
+ *     %true  - this request has more data
+ **/
+bool blk_update_request(struct request *req, int error, unsigned int nr_bytes)
+{
+	int total_bytes, bio_nbytes, next_idx = 0;
+	struct bio *bio;
+
+	if (!req->bio)
+		return false;
+
+	trace_block_rq_complete(req->q, req);
+
+	/*
+	 * For fs requests, rq is just carrier of independent bio's
+	 * and each partial completion should be handled separately.
+	 * Reset per-request error on each partial completion.
+	 *
+	 * TODO: tj: This is too subtle.  It would be better to let
+	 * low level drivers do what they see fit.
+	 */
+	if (req->cmd_type == REQ_TYPE_FS)
+		req->errors = 0;
+
+	if (error && req->cmd_type == REQ_TYPE_FS &&
+	    !(req->cmd_flags & REQ_QUIET)) {
+		char *error_type;
+
+		switch (error) {
+		case -ENOLINK:
+			error_type = "recoverable transport";
+			break;
+		case -EREMOTEIO:
+			error_type = "critical target";
+			break;
+		case -EBADE:
+			error_type = "critical nexus";
+			break;
+		case -EIO:
+		default:
+			error_type = "I/O";
+			break;
+		}
+		printk_ratelimited(KERN_ERR "end_request: %s error, dev %s, sector %llu\n",
+				   error_type, req->rq_disk ?
+				   req->rq_disk->disk_name : "?",
+				   (unsigned long long)blk_rq_pos(req));
+
+	}
+
+	blk_account_io_completion(req, nr_bytes);
+
+	total_bytes = bio_nbytes = 0;
+	while ((bio = req->bio) != NULL) {
+		int nbytes;
+
+		if (nr_bytes >= bio->bi_size) {
+			req->bio = bio->bi_next;
+			nbytes = bio->bi_size;
+			req_bio_endio(req, bio, nbytes, error);
+			next_idx = 0;
+			bio_nbytes = 0;
+		} else {
+			int idx = bio->bi_idx + next_idx;
+
+			if (unlikely(idx >= bio->bi_vcnt)) {
+				blk_dump_rq_flags(req, "__end_that");
+				printk(KERN_ERR "%s: bio idx %d >= vcnt %d\n",
+				       __func__, idx, bio->bi_vcnt);
+				break;
+			}
+
+			nbytes = bio_iovec_idx(bio, idx)->bv_len;
+			BIO_BUG_ON(nbytes > bio->bi_size);
+
+			/*
+			 * not a complete bvec done
+			 */
+			if (unlikely(nbytes > nr_bytes)) {
+				bio_nbytes += nr_bytes;
+				total_bytes += nr_bytes;
+				break;
+			}
+
+			/*
+			 * advance to the next vector
+			 */
+			next_idx++;
+			bio_nbytes += nbytes;
+		}
+
+		total_bytes += nbytes;
+		nr_bytes -= nbytes;
+
+		bio = req->bio;
+		if (bio) {
+			/*
+			 * end more in this run, or just return 'not-done'
+			 */
+			if (unlikely(nr_bytes <= 0))
+				break;
+		}
+	}
+
+	/*
+	 * completely done
+	 */
+	if (!req->bio) {
+		/*
+		 * Reset counters so that the request stacking driver
+		 * can find how many bytes remain in the request
+		 * later.
+		 */
+		req->__data_len = 0;
+		return false;
+	}
+
+	/*
+	 * if the request wasn't completed, update state
+	 */
+	if (bio_nbytes) {
+		req_bio_endio(req, bio, bio_nbytes, error);
+		bio->bi_idx += next_idx;
+		bio_iovec(bio)->bv_offset += nr_bytes;
+		bio_iovec(bio)->bv_len -= nr_bytes;
+	}
+
+	req->__data_len -= total_bytes;
+	req->buffer = bio_data(req->bio);
+
+	/* update sector only for requests with clear definition of sector */
+	if (req->cmd_type == REQ_TYPE_FS)
+		req->__sector += total_bytes >> 9;
+
+	/* mixed attributes always follow the first bio */
+	if (req->cmd_flags & REQ_MIXED_MERGE) {
+		req->cmd_flags &= ~REQ_FAILFAST_MASK;
+		req->cmd_flags |= req->bio->bi_rw & REQ_FAILFAST_MASK;
+	}
+
+	/*
+	 * If total number of sectors is less than the first segment
+	 * size, something has gone terribly wrong.
+	 */
+	if (blk_rq_bytes(req) < blk_rq_cur_bytes(req)) {
+		blk_dump_rq_flags(req, "request botched");
+		req->__data_len = blk_rq_cur_bytes(req);
+	}
+
+	/* recalculate the number of segments */
+	blk_recalc_rq_segments(req);
+
+	return true;
+}
+EXPORT_SYMBOL_GPL(blk_update_request);
+
+static bool blk_update_bidi_request(struct request *rq, int error,
+				    unsigned int nr_bytes,
+				    unsigned int bidi_bytes)
+{
+	if (blk_update_request(rq, error, nr_bytes))
+		return true;
+
+	/* Bidi request must be completed as a whole */
+	if (unlikely(blk_bidi_rq(rq)) &&
+	    blk_update_request(rq->next_rq, error, bidi_bytes))
+		return true;
+
+	if (blk_queue_add_random(rq->q))
+		add_disk_randomness(rq->rq_disk);
+