block: add trace messages to zone write plugging

Add tracepoints to zone write plugging plug and unplug events.

Examples for these events are:

  kworker/u10:4-393  [001] d..1. 282.991660: disk_zone_wplug_add_bio: 8,0 zone 16, BIO 8388608 + 128
  kworker/0:1H-58    [ [000] d..1. 283.083294: blk_zone_wplug_bio: 8,0 zone 15, BIO 7864320 + 128

Reviewed-by: Chaitanya Kulkarni <[email protected]>
Signed-off-by: Johannes Thumshirn <[email protected]>

Author: morbidrsa

block/blk-zoned.c

@@ -822,6 +822,8 @@ static inline void disk_zone_wplug_add_bio(struct gendisk *disk,
 	 * at the tail of the list to preserve the sequential write order.
 	 */
 	bio_list_add(&zwplug->bio_list, bio);
+	trace_disk_zone_wplug_add_bio(zwplug->disk->queue, zwplug->zone_no,
+				      bio->bi_iter.bi_sector, bio_sectors(bio));
 
 	zwplug->flags |= BLK_ZONE_WPLUG_PLUGGED;
 
@@ -1317,6 +1319,9 @@ static void blk_zone_wplug_bio_work(struct work_struct *work)
 		goto put_zwplug;
 	}
 
+	trace_blk_zone_wplug_bio(zwplug->disk->queue, zwplug->zone_no,
+				 bio->bi_iter.bi_sector, bio_sectors(bio));
+
 	if (!blk_zone_wplug_prepare_bio(zwplug, bio)) {
 		blk_zone_wplug_bio_io_error(zwplug, bio);
 		goto again;

include/trace/events/block.h

@@ -633,6 +633,50 @@ TRACE_EVENT(blkdev_zone_mgmt,
 		  (unsigned long long)__entry->sector,
 		  __entry->nr_sectors)
 );
+
+DECLARE_EVENT_CLASS(block_zwplug,
+
+	TP_PROTO(struct request_queue *q, unsigned int zno, sector_t sector,
+		 unsigned int nr_sectors),
+
+	TP_ARGS(q, zno, sector, nr_sectors),
+
+	TP_STRUCT__entry(
+		__field( dev_t,		dev		)
+		__field( unsigned int,	zno		)
+		__field( sector_t,	sector		)
+		__field( unsigned int,	nr_sectors	)
+	),
+
+	TP_fast_assign(
+		__entry->dev		= disk_devt(q->disk);
+		__entry->zno		= zno;
+		__entry->sector		= sector;
+		__entry->nr_sectors	= nr_sectors;
+	),
+
+	TP_printk("%d,%d zone %u, BIO %llu + %u",
+		  MAJOR(__entry->dev), MINOR(__entry->dev), __entry->zno,
+		  (unsigned long long)__entry->sector,
+		  __entry->nr_sectors)
+);
+
+DEFINE_EVENT(block_zwplug, disk_zone_wplug_add_bio,
+
+	TP_PROTO(struct request_queue *q, unsigned int zno, sector_t sector,
+		 unsigned int nr_sectors),
+
+	TP_ARGS(q, zno, sector, nr_sectors)
+);
+
+DEFINE_EVENT(block_zwplug, blk_zone_wplug_bio,
+
+	TP_PROTO(struct request_queue *q, unsigned int zno, sector_t sector,
+		 unsigned int nr_sectors),
+
+	TP_ARGS(q, zno, sector, nr_sectors)
+);
+
 #endif /* _TRACE_BLOCK_H */
 
 /* This part must be outside protection */