From: Kent Overstreet <kent.overstreet@linux.dev>
Date: Wed, 25 Jan 2023 15:18:32 +0000 (-0500)
Subject: bcachefs: Use trylock in bch2_prt_backtrace()
X-Git-Tag: io_uring-6.7-2023-11-10~119^2~583
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=3e57db65cdd93bee55d1ecf53ff4ab895e05c40e;p=linux-block.git

bcachefs: Use trylock in bch2_prt_backtrace()

Easy workaround for a lockdep splat - and since bch2_prt_backtrace() is
only used in debug code this is fine.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
---

diff --git a/fs/bcachefs/util.c b/fs/bcachefs/util.c
index 31934f7a6436..e6672b67ae32 100644
--- a/fs/bcachefs/util.c
+++ b/fs/bcachefs/util.c
@@ -270,11 +270,9 @@ int bch2_prt_backtrace(struct printbuf *out, struct task_struct *task)
 {
 	unsigned long entries[32];
 	unsigned i, nr_entries;
-	int ret;
 
-	ret = down_read_killable(&task->signal->exec_update_lock);
-	if (ret)
-		return ret;
+	if (!down_read_trylock(&task->signal->exec_update_lock))
+		return 0;
 
 	nr_entries = stack_trace_save_tsk(task, entries, ARRAY_SIZE(entries), 0);
 	for (i = 0; i < nr_entries; i++) {