static void msb_io_work()

in core/ms_block.c [1876:1941]

• 52 lines of code
• 10 McCabe index (conditional complexity)

static void msb_io_work(struct work_struct *work)
{
	struct msb_data *msb = container_of(work, struct msb_data, io_work);
	int page, error, len;
	sector_t lba;
	struct scatterlist *sg = msb->prealloc_sg;
	struct request *req;

	dbg_verbose("IO: work started");

	while (1) {
		spin_lock_irq(&msb->q_lock);

		if (msb->need_flush_cache) {
			msb->need_flush_cache = false;
			spin_unlock_irq(&msb->q_lock);
			msb_cache_flush(msb);
			continue;
		}

		req = msb->req;
		if (!req) {
			dbg_verbose("IO: no more requests exiting");
			spin_unlock_irq(&msb->q_lock);
			return;
		}

		spin_unlock_irq(&msb->q_lock);

		/* process the request */
		dbg_verbose("IO: processing new request");
		blk_rq_map_sg(msb->queue, req, sg);

		lba = blk_rq_pos(req);

		sector_div(lba, msb->page_size / 512);
		page = sector_div(lba, msb->pages_in_block);

		if (rq_data_dir(msb->req) == READ)
			error = msb_do_read_request(msb, lba, page, sg,
				blk_rq_bytes(req), &len);
		else
			error = msb_do_write_request(msb, lba, page, sg,
				blk_rq_bytes(req), &len);

		if (len && !blk_update_request(req, BLK_STS_OK, len)) {
			__blk_mq_end_request(req, BLK_STS_OK);
			spin_lock_irq(&msb->q_lock);
			msb->req = NULL;
			spin_unlock_irq(&msb->q_lock);
		}

		if (error && msb->req) {
			blk_status_t ret = errno_to_blk_status(error);

			dbg_verbose("IO: ending one sector of the request with error");
			blk_mq_end_request(req, ret);
			spin_lock_irq(&msb->q_lock);
			msb->req = NULL;
			spin_unlock_irq(&msb->q_lock);
		}

		if (msb->req)
			dbg_verbose("IO: request still pending");
	}
}