waterDataFluctuationCorrelation preliminaryDataProcessing.c 张婷 commit at 2021-01-22

waterDataFluctuationCorrelation/monitoringDataProcessing/preliminaryDataProcessing.c

@@ -1766,3 +1766,104 @@ end_io:
 
 /**
  * generic_make_request - hand a buffer to its device driver for I/O
+ * @bio:  The bio describing the location in memory and on the device.
+ *
+ * generic_make_request() is used to make I/O requests of block
+ * devices. It is passed a &struct bio, which describes the I/O that needs
+ * to be done.
+ *
+ * generic_make_request() does not return any status.  The
+ * success/failure status of the request, along with notification of
+ * completion, is delivered asynchronously through the bio->bi_end_io
+ * function described (one day) else where.
+ *
+ * The caller of generic_make_request must make sure that bi_io_vec
+ * are set to describe the memory buffer, and that bi_dev and bi_sector are
+ * set to describe the device address, and the
+ * bi_end_io and optionally bi_private are set to describe how
+ * completion notification should be signaled.
+ *
+ * generic_make_request and the drivers it calls may use bi_next if this
+ * bio happens to be merged with someone else, and may resubmit the bio to
+ * a lower device by calling into generic_make_request recursively, which
+ * means the bio should NOT be touched after the call to ->make_request_fn.
+ */
+void generic_make_request(struct bio *bio)
+{
+	struct bio_list bio_list_on_stack;
+
+	if (!generic_make_request_checks(bio))
+		return;
+
+	/*
+	 * We only want one ->make_request_fn to be active at a time, else
+	 * stack usage with stacked devices could be a problem.  So use
+	 * current->bio_list to keep a list of requests submited by a
+	 * make_request_fn function.  current->bio_list is also used as a
+	 * flag to say if generic_make_request is currently active in this
+	 * task or not.  If it is NULL, then no make_request is active.  If
+	 * it is non-NULL, then a make_request is active, and new requests
+	 * should be added at the tail
+	 */
+	if (current->bio_list) {
+		bio_list_add(current->bio_list, bio);
+		return;
+	}
+
+	/* following loop may be a bit non-obvious, and so deserves some
+	 * explanation.
+	 * Before entering the loop, bio->bi_next is NULL (as all callers
+	 * ensure that) so we have a list with a single bio.
+	 * We pretend that we have just taken it off a longer list, so
+	 * we assign bio_list to a pointer to the bio_list_on_stack,
+	 * thus initialising the bio_list of new bios to be
+	 * added.  ->make_request() may indeed add some more bios
+	 * through a recursive call to generic_make_request.  If it
+	 * did, we find a non-NULL value in bio_list and re-enter the loop
+	 * from the top.  In this case we really did just take the bio
+	 * of the top of the list (no pretending) and so remove it from
+	 * bio_list, and call into ->make_request() again.
+	 */
+	BUG_ON(bio->bi_next);
+	bio_list_init(&bio_list_on_stack);
+	current->bio_list = &bio_list_on_stack;
+	do {
+		struct request_queue *q = bdev_get_queue(bio->bi_bdev);
+
+		q->make_request_fn(q, bio);
+
+		bio = bio_list_pop(current->bio_list);
+	} while (bio);
+	current->bio_list = NULL; /* deactivate */
+}
+EXPORT_SYMBOL(generic_make_request);
+
+/**
+ * submit_bio - submit a bio to the block device layer for I/O
+ * @rw: whether to %READ or %WRITE, or maybe to %READA (read ahead)
+ * @bio: The &struct bio which describes the I/O
+ *
+ * submit_bio() is very similar in purpose to generic_make_request(), and
+ * uses that function to do most of the work. Both are fairly rough
+ * interfaces; @bio must be presetup and ready for I/O.
+ *
+ */
+void submit_bio(int rw, struct bio *bio)
+{
+	bio->bi_rw |= rw;
+
+	/*
+	 * If it's a regular read/write or a barrier with data attached,
+	 * go through the normal accounting stuff before submission.
+	 */
+	if (bio_has_data(bio)) {
+		unsigned int count;
+
+		if (unlikely(rw & REQ_WRITE_SAME))
+			count = bdev_logical_block_size(bio->bi_bdev) >> 9;
+		else
+			count = bio_sectors(bio);
+
+		if (rw & WRITE) {
+			count_vm_events(PGPGOUT, count);
+		} else {