From: Luis Chamberlain <mcgrof@kernel.org>
Date: Fri, 19 Jun 2020 20:47:26 +0000 (+0000)
Subject: blktrace: annotate required lock on do_blk_trace_setup()
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=a67549c8e568627290234e9fbe833cb9dfd36b55;p=uclinux-h8%2Flinux.git

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>
---

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 5ef0484513ec..5a88a6b55933 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;