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 155e7c9bd89fe6474a8a3022454d0285887e660e..424d5cf48893a1befc1023bcff6a46ea0a9a6843 100644 (file)
--- 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))