Re: [PATCH v3 3/6] bpf: add BPF_PROG_ATTACH and BPF_PROG_DETACH commands

On Mon, 2016-09-05 at 14:56 +0200, Daniel Mack wrote:

On 08/27/2016 02:08 AM, Alexei Starovoitov wrote:

[]

quoted

+	switch (attr->attach_type) {
+	case BPF_ATTACH_TYPE_CGROUP_INET_INGRESS:
+	case BPF_ATTACH_TYPE_CGROUP_INET_EGRESS: {
+		struct cgroup *cgrp;
+
+		prog = bpf_prog_get_type(attr->attach_bpf_fd,
+					 BPF_PROG_TYPE_CGROUP_SOCKET_FILTER);
+		if (IS_ERR(prog))
+			return PTR_ERR(prog);
+
+		cgrp = cgroup_get_from_fd(attr->target_fd);
+		if (IS_ERR(cgrp)) {
+			bpf_prog_put(prog);
+			return PTR_ERR(cgrp);
+		}
+
+		cgroup_bpf_update(cgrp, prog, attr->attach_type);
+		cgroup_put(cgrp);
+
+		break;
+	}

this } formatting style is confusing. The above } looks
like it matches 'switch () {'.
May be move 'struct cgroup *cgrp' to the top to avoid that?

This style of case statements that declare local variables
with an open brace after the case statement

	switch (bar) {
	[cases...]
	case foo: {
		local declarations;

		code...
	}
	[cases...]
	}

is used quite frequently in the kernel.
I think it's fine as is.