From: Matthew Wilcox <willy@parisc-linux.org>
Date: Thu, 31 Dec 2020 22:05:08 +0000 (+0000)
Subject: Releasing resources with children
X-Git-Tag: howlett/maple_spf/20210104~74
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=450345ec8cf0f39957f8af3773f9eaeab36fc022;p=users%2Fjedix%2Flinux-maple.git

Releasing resources with children

What does it mean to release a resource with children?  Should the children
become children of the released resource's parent?  Should they be released
too?  Should we fail the release?

I bet we have no callers who expect this right now, but with
insert_resource() we may get some.  At the point where someone hits this
BUG we can figure out what semantics we want.

Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/kernel/resource.c b/kernel/resource.c
index 46c410dccb38..8d3ed6c0fd95 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -222,6 +222,8 @@ static int __release_resource(struct resource *old, bool release_child)
 		}
 	}
 
+	WARN_ON(old->child);
+
 	p = &old->parent->child;
 	for (;;) {
 		tmp = *p;