[PATCH v2 13/15] blktrace: trace zone management operations

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 <[email protected]>
---
 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 ddc9fedf4955..e4b6fbbc40ee 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