From: Steven Rostedt <rostedt@goodmis.org>
Date: Mon, 22 Aug 2011 03:52:28 +0000 (+0800)
Subject: autofs4 - fix lockdep splat in autofs
X-Git-Tag: firefly_0821_release~3680^2~3506^2~5
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=1d6f2097865e64963e90cce04980dce2f9fc023f;p=firefly-linux-kernel-4.4.55.git

autofs4 - fix lockdep splat in autofs

When recursing down the locks when traversing a tree/list in
get_next_positive_dentry() or get_next_positive_subdir() a lock can
change from being nested to being a parent which breaks lockdep. This
patch tells lockdep about what we did.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Ian Kent <raven@themaw.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---

diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c
index 450f529a4eae..1feb68ecef95 100644
--- a/fs/autofs4/expire.c
+++ b/fs/autofs4/expire.c
@@ -124,6 +124,7 @@ start:
 	/* Negative dentry - try next */
 	if (!simple_positive(q)) {
 		spin_unlock(&p->d_lock);
+		lock_set_subclass(&q->d_lock.dep_map, 0, _RET_IP_);
 		p = q;
 		goto again;
 	}
@@ -186,6 +187,7 @@ again:
 	/* Negative dentry - try next */
 	if (!simple_positive(ret)) {
 		spin_unlock(&p->d_lock);
+		lock_set_subclass(&ret->d_lock.dep_map, 0, _RET_IP_);
 		p = ret;
 		goto again;
 	}