blk-rq-qos: store a gendisk instead of request_queue in struct rq_qos

This is what about half of the users already want, and it's only going to
grow more.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230203150400.3199230-16-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-iocost.c

@@ -669,7 +669,7 @@ static struct ioc *q_to_ioc(struct request_queue *q)
 
 static const char __maybe_unused *ioc_name(struct ioc *ioc)
 {
-	struct gendisk *disk = ioc->rqos.q->disk;
+	struct gendisk *disk = ioc->rqos.disk;
 
 	if (!disk)
 		return "<unknown>";
@@ -808,11 +808,11 @@ static int ioc_autop_idx(struct ioc *ioc)
 	u64 now_ns;
 
 	/* rotational? */
-	if (!blk_queue_nonrot(ioc->rqos.q))
+	if (!blk_queue_nonrot(ioc->rqos.disk->queue))
 		return AUTOP_HDD;
 
 	/* handle SATA SSDs w/ broken NCQ */
-	if (blk_queue_depth(ioc->rqos.q) == 1)
+	if (blk_queue_depth(ioc->rqos.disk->queue) == 1)
 		return AUTOP_SSD_QD1;
 
 	/* use one of the normal ssd sets */
@@ -2649,7 +2649,7 @@ retry_lock:
 	if (use_debt) {
 		iocg_incur_debt(iocg, abs_cost, &now);
 		if (iocg_kick_delay(iocg, &now))
-			blkcg_schedule_throttle(rqos->q->disk,
+			blkcg_schedule_throttle(rqos->disk,
 					(bio->bi_opf & REQ_SWAP) == REQ_SWAP);
 		iocg_unlock(iocg, ioc_locked, &flags);
 		return;
@@ -2750,7 +2750,7 @@ static void ioc_rqos_merge(struct rq_qos *rqos, struct request *rq,
 	if (likely(!list_empty(&iocg->active_list))) {
 		iocg_incur_debt(iocg, abs_cost, &now);
 		if (iocg_kick_delay(iocg, &now))
-			blkcg_schedule_throttle(rqos->q->disk,
+			blkcg_schedule_throttle(rqos->disk,
 					(bio->bi_opf & REQ_SWAP) == REQ_SWAP);
 	} else {
 		iocg_commit_bio(iocg, bio, abs_cost, cost);
@@ -2821,7 +2821,7 @@ static void ioc_rqos_exit(struct rq_qos *rqos)
 {
 	struct ioc *ioc = rqos_to_ioc(rqos);
 
-	blkcg_deactivate_policy(rqos->q, &blkcg_policy_iocost);
+	blkcg_deactivate_policy(rqos->disk->queue, &blkcg_policy_iocost);
 
 	spin_lock_irq(&ioc->lock);
 	ioc->running = IOC_STOP;

block/blk-iolatency.c

@@ -292,7 +292,7 @@ static void __blkcg_iolatency_throttle(struct rq_qos *rqos,
 	unsigned use_delay = atomic_read(&lat_to_blkg(iolat)->use_delay);
 
 	if (use_delay)
-		blkcg_schedule_throttle(rqos->q->disk, use_memdelay);
+		blkcg_schedule_throttle(rqos->disk, use_memdelay);
 
 	/*
 	 * To avoid priority inversions we want to just take a slot if we are
@@ -330,7 +330,7 @@ static void scale_cookie_change(struct blk_iolatency *blkiolat,
 				struct child_latency_info *lat_info,
 				bool up)
 {
-	unsigned long qd = blkiolat->rqos.q->nr_requests;
+	unsigned long qd = blkiolat->rqos.disk->queue->nr_requests;
 	unsigned long scale = scale_amount(qd, up);
 	unsigned long old = atomic_read(&lat_info->scale_cookie);
 	unsigned long max_scale = qd << 1;
@@ -372,7 +372,7 @@ static void scale_cookie_change(struct blk_iolatency *blkiolat,
  */
 static void scale_change(struct iolatency_grp *iolat, bool up)
 {
-	unsigned long qd = iolat->blkiolat->rqos.q->nr_requests;
+	unsigned long qd = iolat->blkiolat->rqos.disk->queue->nr_requests;
 	unsigned long scale = scale_amount(qd, up);
 	unsigned long old = iolat->max_depth;
 
@@ -646,7 +646,7 @@ static void blkcg_iolatency_exit(struct rq_qos *rqos)
 
 	timer_shutdown_sync(&blkiolat->timer);
 	flush_work(&blkiolat->enable_work);
-	blkcg_deactivate_policy(rqos->q, &blkcg_policy_iolatency);
+	blkcg_deactivate_policy(rqos->disk->queue, &blkcg_policy_iolatency);
 	kfree(blkiolat);
 }
 
@@ -665,7 +665,7 @@ static void blkiolatency_timer_fn(struct timer_list *t)
 
 	rcu_read_lock();
 	blkg_for_each_descendant_pre(blkg, pos_css,
-				     blkiolat->rqos.q->root_blkg) {
+				     blkiolat->rqos.disk->queue->root_blkg) {
 		struct iolatency_grp *iolat;
 		struct child_latency_info *lat_info;
 		unsigned long flags;
@@ -749,9 +749,9 @@ static void blkiolatency_enable_work_fn(struct work_struct *work)
 	 */
 	enabled = atomic_read(&blkiolat->enable_cnt);
 	if (enabled != blkiolat->enabled) {
-		blk_mq_freeze_queue(blkiolat->rqos.q);
+		blk_mq_freeze_queue(blkiolat->rqos.disk->queue);
 		blkiolat->enabled = enabled;
-		blk_mq_unfreeze_queue(blkiolat->rqos.q);
+		blk_mq_unfreeze_queue(blkiolat->rqos.disk->queue);
 	}
 }
 

block/blk-mq-debugfs.c

@@ -813,9 +813,9 @@ static const char *rq_qos_id_to_name(enum rq_qos_id id)
 
 void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
 {
-	lockdep_assert_held(&rqos->q->debugfs_mutex);
+	lockdep_assert_held(&rqos->disk->queue->debugfs_mutex);
 
-	if (!rqos->q->debugfs_dir)
+	if (!rqos->disk->queue->debugfs_dir)
 		return;
 	debugfs_remove_recursive(rqos->debugfs_dir);
 	rqos->debugfs_dir = NULL;
@@ -823,7 +823,7 @@ void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
 
 void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
 {
-	struct request_queue *q = rqos->q;
+	struct request_queue *q = rqos->disk->queue;
 	const char *dir_name = rq_qos_id_to_name(rqos->id);
 
 	lockdep_assert_held(&q->debugfs_mutex);
@@ -835,9 +835,7 @@ void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
 		q->rqos_debugfs_dir = debugfs_create_dir("rqos",
 							 q->debugfs_dir);
 
-	rqos->debugfs_dir = debugfs_create_dir(dir_name,
-					       rqos->q->rqos_debugfs_dir);
-
+	rqos->debugfs_dir = debugfs_create_dir(dir_name, q->rqos_debugfs_dir);
 	debugfs_create_files(rqos->debugfs_dir, rqos, rqos->ops->debugfs_attrs);
 }
 

block/blk-rq-qos.c

@@ -300,7 +300,7 @@ int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id,
 {
 	struct request_queue *q = disk->queue;
 
-	rqos->q = q;
+	rqos->disk = disk;
 	rqos->id = id;
 	rqos->ops = ops;
 
@@ -337,7 +337,7 @@ ebusy:
 
 void rq_qos_del(struct rq_qos *rqos)
 {
-	struct request_queue *q = rqos->q;
+	struct request_queue *q = rqos->disk->queue;
 	struct rq_qos **cur;
 
 	/*

block/blk-rq-qos.h

@@ -26,7 +26,7 @@ struct rq_wait {
 
 struct rq_qos {
 	const struct rq_qos_ops *ops;
-	struct request_queue *q;
+	struct gendisk *disk;
 	enum rq_qos_id id;
 	struct rq_qos *next;
 #ifdef CONFIG_BLK_DEBUG_FS

block/blk-wbt.c

@@ -165,7 +165,7 @@ static void wb_timestamp(struct rq_wb *rwb, unsigned long *var)
  */
 static bool wb_recent_wait(struct rq_wb *rwb)
 {
-	struct bdi_writeback *wb = &rwb->rqos.q->disk->bdi->wb;
+	struct bdi_writeback *wb = &rwb->rqos.disk->bdi->wb;
 
 	return time_before(jiffies, wb->dirty_sleep + HZ);
 }
@@ -312,7 +312,7 @@ enum {
 
 static int latency_exceeded(struct rq_wb *rwb, struct blk_rq_stat *stat)
 {
-	struct backing_dev_info *bdi = rwb->rqos.q->disk->bdi;
+	struct backing_dev_info *bdi = rwb->rqos.disk->bdi;
 	struct rq_depth *rqd = &rwb->rq_depth;
 	u64 thislat;
 
@@ -365,7 +365,7 @@ static int latency_exceeded(struct rq_wb *rwb, struct blk_rq_stat *stat)
 
 static void rwb_trace_step(struct rq_wb *rwb, const char *msg)
 {
-	struct backing_dev_info *bdi = rwb->rqos.q->disk->bdi;
+	struct backing_dev_info *bdi = rwb->rqos.disk->bdi;
 	struct rq_depth *rqd = &rwb->rq_depth;
 
 	trace_wbt_step(bdi, msg, rqd->scale_step, rwb->cur_win_nsec,
@@ -435,13 +435,12 @@ static void wb_timer_fn(struct blk_stat_callback *cb)
 	unsigned int inflight = wbt_inflight(rwb);
 	int status;
 
-	if (!rwb->rqos.q->disk)
+	if (!rwb->rqos.disk)
 		return;
 
 	status = latency_exceeded(rwb, cb->stat);
 
-	trace_wbt_timer(rwb->rqos.q->disk->bdi, status, rqd->scale_step,
-			inflight);
+	trace_wbt_timer(rwb->rqos.disk->bdi, status, rqd->scale_step, inflight);
 
 	/*
 	 * If we exceeded the latency target, step down. If we did not,
@@ -779,16 +778,15 @@ static int wbt_data_dir(const struct request *rq)
 
 static void wbt_queue_depth_changed(struct rq_qos *rqos)
 {
-	RQWB(rqos)->rq_depth.queue_depth = blk_queue_depth(rqos->q);
+	RQWB(rqos)->rq_depth.queue_depth = blk_queue_depth(rqos->disk->queue);
 	wbt_update_limits(RQWB(rqos));
 }
 
 static void wbt_exit(struct rq_qos *rqos)
 {
 	struct rq_wb *rwb = RQWB(rqos);
-	struct request_queue *q = rqos->q;
 
-	blk_stat_remove_callback(q, rwb->cb);
+	blk_stat_remove_callback(rqos->disk->queue, rwb->cb);
 	blk_stat_free_callback(rwb->cb);
 	kfree(rwb);
 }