From: Jan Kara <jack@suse.cz>
Date: Wed, 13 May 2020 18:02:23 +0200
Subject: [PATCH] blktrace: Report pid with note messages
Git-commit: 870c153cf0e6df1b8b5226af41b19945e8e0d143
Patch-mainline: v5.8-rc1
References: bsc#1175995,jsc#SLE-15608

Currently informational messages within block trace do not have PID
information of the process reporting the message included. With BFQ it
is sometimes useful to have the information and there's no good reason
to omit the information from the trace. So just fill in pid information
when generating note message.

Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Acked-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.com>
---
 kernel/trace/blktrace.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index ca39dc3230cb..ea47f2084087 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -170,10 +170,10 @@ void __trace_note_message(struct blk_trace *bt, struct blkcg *blkcg,
 	if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP))
 		blkcg = NULL;
 #ifdef CONFIG_BLK_CGROUP
-	trace_note(bt, 0, BLK_TN_MESSAGE, buf, n,
+	trace_note(bt, current->pid, BLK_TN_MESSAGE, buf, n,
 		   blkcg ? cgroup_id(blkcg->css.cgroup) : 1);
 #else
-	trace_note(bt, 0, BLK_TN_MESSAGE, buf, n, 0);
+	trace_note(bt, current->pid, BLK_TN_MESSAGE, buf, n, 0);
 #endif
 	local_irq_restore(flags);
 }
-- 
2.16.4