[PATCH 13/16] blktrace: expose ZONE APPEND completions to blktrace

[Johannes Thumshirn]

Expose ZONE APPEND completions as a block trace completion action to
blktrace.

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.thumsh...@wdc.com>
---
 include/uapi/linux/blktrace_api.h |  3 +++
 kernel/trace/blktrace.c           | 21 +++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/include/uapi/linux/blktrace_api.h 
b/include/uapi/linux/blktrace_api.h
index d5047467c8ee..c75ae82b2dbc 100644
--- a/include/uapi/linux/blktrace_api.h
+++ b/include/uapi/linux/blktrace_api.h
@@ -99,6 +99,9 @@ enum blktrace_notify {
 #define BLK_TA_ABORT           (__BLK_TA_ABORT | BLK_TC_ACT(BLK_TC_QUEUE))
 #define BLK_TA_DRV_DATA        (__BLK_TA_DRV_DATA | 
BLK_TC_ACT(BLK_TC_DRV_DATA))
 
+#define BLK_TA_ZONE_APPEND     (__BLK_TA_COMPLETE |\
+                                BLK_TC_ACT2(BLK_TC_ZONE_APPEND))
+
 #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))
 #define BLK_TN_MESSAGE         (__BLK_TN_MESSAGE | BLK_TC_ACT(BLK_TC_NOTIFY))
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 62f6cfcee4f6..fea6e63ee27c 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -972,6 +972,22 @@ static void blk_add_trace_rq_complete(void *ignore, struct 
request *rq,
                         blk_trace_request_get_cgid(rq));
 }
 
+static void blk_add_trace_zone_update_request(void *ignore, struct request *rq)
+{
+       struct blk_trace *bt;
+
+       rcu_read_lock();
+       bt = rcu_dereference(rq->q->blk_trace);
+       if (likely(!bt) || bt->version < 2) {
+               rcu_read_unlock();
+               return;
+       }
+       rcu_read_unlock();
+
+       blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_ZONE_APPEND,
+                        blk_trace_request_get_cgid(rq));
+}
+
 /**
  * blk_add_trace_bio - Add a trace for a bio oriented action
  * @q:         queue the io is for
@@ -1202,6 +1218,9 @@ static void blk_register_tracepoints(void)
        WARN_ON(ret);
        ret = register_trace_block_getrq(blk_add_trace_getrq, NULL);
        WARN_ON(ret);
+       ret = register_trace_blk_zone_append_update_request_bio(
+               blk_add_trace_zone_update_request, 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);
@@ -1221,6 +1240,8 @@ 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_blk_zone_append_update_request_bio(
+               blk_add_trace_zone_update_request, NULL);
        unregister_trace_block_getrq(blk_add_trace_getrq, NULL);
        unregister_trace_block_bio_queue(blk_add_trace_bio_queue, NULL);
        unregister_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge, 
NULL);
-- 
2.51.0