commit a67549c8e568627290234e9fbe833cb9dfd36b55
author Luis Chamberlain <mcgrof@kernel.org> Fri Jun 19 20:47:26 2020 +0000
committer Jens Axboe <axboe@kernel.dk> Wed Jun 24 09:15:58 2020 -0600
tree ac319553d06643c219235dc5d2951ae8e8ac3c2f
parent e8c7d14ac6c37c173ec606907d38802b00302988

blktrace: annotate required lock on do_blk_trace_setup()

Ensure it is clear which lock is required on do_blk_trace_setup().

Suggested-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

kernel/trace/blktrace.c

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 5ef0484..5a88a6b 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -483,6 +483,8 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
 	struct dentry *dir = NULL;
 	int ret;
 
+	lockdep_assert_held(&q->blk_trace_mutex);
+
 	if (!buts->buf_size || !buts->buf_nr)
 		return -EINVAL;