On Thu, Nov 30, 2023 at 8:37 AM Simon Horman [off-list ref] wrote:

On Mon, Nov 27, 2023 at 11:03:54AM -0800, Andrii Nakryiko wrote:

...

quoted

@@ -764,7 +817,10 @@ static int bpf_get_tree(struct fs_context *fc)

 static void bpf_free_fc(struct fs_context *fc)
 {
-     kfree(fc->fs_private);
+     struct bpf_mount_opts *opts = fc->s_fs_info;
+
+     if (opts)
+             kfree(opts);
 }

Hi Andrii,

as it looks like there will be a v12, I have a minor nit to report: There
is no need to check if opts is non-NULL because kfree() is basically a
no-op if it's argument is NULL.

So perhaps this can become (completely untested!):

static void bpf_free_fc(struct fs_context *fc)
{
        kfree(fc->s_fs_info);
}

sure, I can drop the check, I wasn't sure if it's canonical or not to
check the argument for NULL before calling kfree(). For user-space
it's definitely quite expected to not have to check for null before
calling free().

...