Trace zone management operations on block devices.

As tracing of zoned block commands needs the upper 32bit of the widened
64bit action, only add traces to blktrace if user-space has requested
version 2 of the blktrace protocol.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
---
 include/uapi/linux/blktrace_api.h |  2 ++
 kernel/trace/blktrace.c           | 20 ++++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/include/uapi/linux/blktrace_api.h b/include/uapi/linux/blktrace_api.h
index c75ae82b2dbc..074c4de62c3e 100644
--- a/include/uapi/linux/blktrace_api.h
+++ b/include/uapi/linux/blktrace_api.h
@@ -64,6 +64,7 @@ enum blktrace_act {
 	__BLK_TA_REMAP,			/* bio was remapped */
 	__BLK_TA_ABORT,			/* request aborted */
 	__BLK_TA_DRV_DATA,		/* driver-specific binary data */
+	__BLK_TA_ZONE_MGMT,		/* zone management command was issued */
 	__BLK_TA_CGROUP = 1 << 8,	/* from a cgroup*/
 };
 
@@ -101,6 +102,7 @@ enum blktrace_notify {
 
 #define BLK_TA_ZONE_APPEND	(__BLK_TA_COMPLETE |\
 				 BLK_TC_ACT2(BLK_TC_ZONE_APPEND))
+#define BLK_TA_ZONE_MGMT	__BLK_TA_ZONE_MGMT
 
 #define BLK_TN_PROCESS		(__BLK_TN_PROCESS | BLK_TC_ACT(BLK_TC_NOTIFY))
 #define BLK_TN_TIMESTAMP	(__BLK_TN_TIMESTAMP | BLK_TC_ACT(BLK_TC_NOTIFY))
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index fea6e63ee27c..13424efbb2f6 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -1046,6 +1046,22 @@ static void blk_add_trace_getrq(void *ignore, struct bio *bio)
 	blk_add_trace_bio(bio->bi_bdev->bd_disk->queue, bio, BLK_TA_GETRQ, 0);
 }
 
+static void blk_add_trace_blkdev_zone_mgmt(void *ignore, struct bio *bio,
+					   sector_t nr_sectors)
+{
+	struct request_queue *q = bio->bi_bdev->bd_disk->queue;
+	struct blk_trace *bt;
+
+	rcu_read_lock();
+	bt = rcu_dereference(q->blk_trace);
+	if (unlikely(!bt) || bt->version < 2) {
+		rcu_read_unlock();
+		return;
+	}
+	rcu_read_unlock();
+	blk_add_trace_bio(q, bio, BLK_TA_ZONE_MGMT, 0);
+}
+
 static void blk_add_trace_plug(void *ignore, struct request_queue *q)
 {
 	struct blk_trace *bt;
@@ -1221,6 +1237,9 @@ static void blk_register_tracepoints(void)
 	ret = register_trace_blk_zone_append_update_request_bio(
 		blk_add_trace_zone_update_request, NULL);
 	WARN_ON(ret);
+	ret = register_trace_blkdev_zone_mgmt(blk_add_trace_blkdev_zone_mgmt,
+					      NULL);
+	WARN_ON(ret);
 	ret = register_trace_block_plug(blk_add_trace_plug, NULL);
 	WARN_ON(ret);
 	ret = register_trace_block_unplug(blk_add_trace_unplug, NULL);
@@ -1240,6 +1259,7 @@ static void blk_unregister_tracepoints(void)
 	unregister_trace_block_split(blk_add_trace_split, NULL);
 	unregister_trace_block_unplug(blk_add_trace_unplug, NULL);
 	unregister_trace_block_plug(blk_add_trace_plug, NULL);
+	unregister_trace_blkdev_zone_mgmt(blk_add_trace_blkdev_zone_mgmt, NULL);
 	unregister_trace_blk_zone_append_update_request_bio(
 		blk_add_trace_zone_update_request, NULL);
 	unregister_trace_block_getrq(blk_add_trace_getrq, NULL);
-- 
2.51.0