From: Kent Overstreet <kent.overstreet@gmail.com>
Date: Wed, 2 Oct 2019 13:14:32 +0000 (-0400)
Subject: bcachefs: Fix undefined behaviour
X-Git-Tag: v6.7-rc1~201^2~2321
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=618b9e575b40c862a62764043c961646f3ebc6dc;p=thirdparty%2Flinux.git

bcachefs: Fix undefined behaviour

roundup_pow_of_two(0) is undefined

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

diff --git a/fs/bcachefs/ec.c b/fs/bcachefs/ec.c
index 155e7c9bd89fe..424d5cf48893a 100644
--- a/fs/bcachefs/ec.c
+++ b/fs/bcachefs/ec.c
@@ -1351,6 +1351,9 @@ int bch2_ec_mem_alloc(struct bch_fs *c, bool gc)
 	if (ret)
 		return ret;
 
+	if (!idx)
+		return 0;
+
 	if (!gc &&
 	    !init_heap(&c->ec_stripes_heap, roundup_pow_of_two(idx),
 		       GFP_KERNEL))