waterDataFluctuationCorrelation preliminaryDataProcessing.c 张婷 commit at 2020-12-07

waterDataFluctuationCorrelation/monitoringDataProcessing/preliminaryDataProcessing.c

@@ -978,3 +978,144 @@ static struct request *__get_request(struct request_list *rl, int rw_flags,
 			icq = ioc_lookup_icq(ioc, q);
 	}
 
+	if (blk_queue_io_stat(q))
+		rw_flags |= REQ_IO_STAT;
+	spin_unlock_irq(q->queue_lock);
+
+	/* allocate and init request */
+	rq = mempool_alloc(rl->rq_pool, gfp_mask);
+	if (!rq)
+		goto fail_alloc;
+
+	blk_rq_init(q, rq);
+	blk_rq_set_rl(rq, rl);
+	rq->cmd_flags = rw_flags | REQ_ALLOCED;
+
+	/* init elvpriv */
+	if (rw_flags & REQ_ELVPRIV) {
+		if (unlikely(et->icq_cache && !icq)) {
+			if (ioc)
+				icq = ioc_create_icq(ioc, q, gfp_mask);
+			if (!icq)
+				goto fail_elvpriv;
+		}
+
+		rq->elv.icq = icq;
+		if (unlikely(elv_set_request(q, rq, bio, gfp_mask)))
+			goto fail_elvpriv;
+
+		/* @rq->elv.icq holds io_context until @rq is freed */
+		if (icq)
+			get_io_context(icq->ioc);
+	}
+out:
+	/*
+	 * ioc may be NULL here, and ioc_batching will be false. That's
+	 * OK, if the queue is under the request limit then requests need
+	 * not count toward the nr_batch_requests limit. There will always
+	 * be some limit enforced by BLK_BATCH_TIME.
+	 */
+	if (ioc_batching(q, ioc))
+		ioc->nr_batch_requests--;
+
+	trace_block_getrq(q, bio, rw_flags & 1);
+	return rq;
+
+fail_elvpriv:
+	/*
+	 * elvpriv init failed.  ioc, icq and elvpriv aren't mempool backed
+	 * and may fail indefinitely under memory pressure and thus
+	 * shouldn't stall IO.  Treat this request as !elvpriv.  This will
+	 * disturb iosched and blkcg but weird is bettern than dead.
+	 */
+	printk_ratelimited(KERN_WARNING "%s: request aux data allocation failed, iosched may be disturbed\n",
+			   dev_name(q->backing_dev_info.dev));
+
+	rq->cmd_flags &= ~REQ_ELVPRIV;
+	rq->elv.icq = NULL;
+
+	spin_lock_irq(q->queue_lock);
+	q->nr_rqs_elvpriv--;
+	spin_unlock_irq(q->queue_lock);
+	goto out;
+
+fail_alloc:
+	/*
+	 * Allocation failed presumably due to memory. Undo anything we
+	 * might have messed up.
+	 *
+	 * Allocating task should really be put onto the front of the wait
+	 * queue, but this is pretty rare.
+	 */
+	spin_lock_irq(q->queue_lock);
+	freed_request(rl, rw_flags);
+
+	/*
+	 * in the very unlikely event that allocation failed and no
+	 * requests for this direction was pending, mark us starved so that
+	 * freeing of a request in the other direction will notice
+	 * us. another possible fix would be to split the rq mempool into
+	 * READ and WRITE
+	 */
+rq_starved:
+	if (unlikely(rl->count[is_sync] == 0))
+		rl->starved[is_sync] = 1;
+	return NULL;
+}
+
+/**
+ * get_request - get a free request
+ * @q: request_queue to allocate request from
+ * @rw_flags: RW and SYNC flags
+ * @bio: bio to allocate request for (can be %NULL)
+ * @gfp_mask: allocation mask
+ *
+ * Get a free request from @q.  If %__GFP_WAIT is set in @gfp_mask, this
+ * function keeps retrying under memory pressure and fails iff @q is dead.
+ *
+ * Must be callled with @q->queue_lock held and,
+ * Returns %NULL on failure, with @q->queue_lock held.
+ * Returns !%NULL on success, with @q->queue_lock *not held*.
+ */
+static struct request *get_request(struct request_queue *q, int rw_flags,
+				   struct bio *bio, gfp_t gfp_mask)
+{
+	const bool is_sync = rw_is_sync(rw_flags) != 0;
+	DEFINE_WAIT(wait);
+	struct request_list *rl;
+	struct request *rq;
+
+	rl = blk_get_rl(q, bio);	/* transferred to @rq on success */
+retry:
+	rq = __get_request(rl, rw_flags, bio, gfp_mask);
+	if (rq)
+		return rq;
+
+	if (!(gfp_mask & __GFP_WAIT) || unlikely(blk_queue_dying(q))) {
+		blk_put_rl(rl);
+		return NULL;
+	}
+
+	/* wait on @rl and retry */
+	prepare_to_wait_exclusive(&rl->wait[is_sync], &wait,
+				  TASK_UNINTERRUPTIBLE);
+
+	trace_block_sleeprq(q, bio, rw_flags & 1);
+
+	spin_unlock_irq(q->queue_lock);
+	io_schedule();
+
+	/*
+	 * After sleeping, we become a "batching" process and will be able
+	 * to allocate at least one request, and up to a big batch of them
+	 * for a small period time.  See ioc_batching, ioc_set_batching
+	 */
+	ioc_set_batching(q, current->io_context);
+
+	spin_lock_irq(q->queue_lock);
+	finish_wait(&rl->wait[is_sync], &wait);
+
+	goto retry;
+}
+
+struct request *blk_get_request(struct request_queue *q, int rw, gfp_t gfp_mask)