Re: [syzbot] [block?] [trace?] INFO: task hung in blk_trace_remove (2)

From: Edward Adam Davis
Date: Wed Jan 31 2024 - 05:24:59 EST


please test task hung in blk_trace_remove

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index d5d94510afd3..eede951d198a 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -381,8 +381,10 @@ static void blk_trace_cleanup(struct request_queue *q, struct blk_trace *bt)
{
blk_trace_stop(bt);
synchronize_rcu();
+ mutex_unlock(&q->debugfs_mutex);
blk_trace_free(q, bt);
put_probe_ref();
+ mutex_lock(&q->debugfs_mutex);
}

static int __blk_trace_remove(struct request_queue *q)