bpf: udp: Get rid of st_bucket_done

Get rid of the st_bucket_done field to simplify UDP iterator state and
logic. Before, st_bucket_done could be false if bpf_iter_udp_batch
returned a partial batch; however, with the last patch ("bpf: udp: Make
sure iter->batch always contains a full bucket snapshot"),
st_bucket_done == true is equivalent to iter->cur_sk == iter->end_sk.

Signed-off-by: Jordan Rife <[email protected]>

Author: jrife

net/ipv4/udp.c

@@ -3397,7 +3397,6 @@ struct bpf_udp_iter_state {
 	unsigned int max_sk;
 	int offset;
 	struct sock **batch;
-	bool st_bucket_done;
 };
 
 static int bpf_iter_udp_realloc_batch(struct bpf_udp_iter_state *iter,
@@ -3418,7 +3417,7 @@ static struct sock *bpf_iter_udp_batch(struct seq_file *seq)
 	resume_offset = iter->offset;
 
 	/* The current batch is done, so advance the bucket. */
-	if (iter->st_bucket_done)
+	if (iter->cur_sk == iter->end_sk)
 		state->bucket++;
 
 	udptable = udp_get_table_seq(seq, net);
@@ -3433,7 +3432,6 @@ static struct sock *bpf_iter_udp_batch(struct seq_file *seq)
 	 */
 	iter->cur_sk = 0;
 	iter->end_sk = 0;
-	iter->st_bucket_done = true;
 	batch_sks = 0;
 
 	for (; state->bucket <= udptable->mask; state->bucket++) {
@@ -3596,8 +3594,10 @@ static int bpf_iter_udp_seq_show(struct seq_file *seq, void *v)
 
 static void bpf_iter_udp_put_batch(struct bpf_udp_iter_state *iter)
 {
-	while (iter->cur_sk < iter->end_sk)
-		sock_put(iter->batch[iter->cur_sk++]);
+	unsigned int cur_sk = iter->cur_sk;
+
+	while (cur_sk < iter->end_sk)
+		sock_put(iter->batch[cur_sk++]);
 }
 
 static void bpf_iter_udp_seq_stop(struct seq_file *seq, void *v)
@@ -3613,10 +3613,8 @@ static void bpf_iter_udp_seq_stop(struct seq_file *seq, void *v)
 			(void)udp_prog_seq_show(prog, &meta, v, 0, 0);
 	}
 
-	if (iter->cur_sk < iter->end_sk) {
+	if (iter->cur_sk < iter->end_sk)
 		bpf_iter_udp_put_batch(iter);
-		iter->st_bucket_done = false;
-	}
 }
 
 static const struct seq_operations bpf_iter_udp_seq_ops = {
@@ -3893,6 +3891,8 @@ static int bpf_iter_init_udp(void *priv_data, struct bpf_iter_aux_info *aux)
 	if (ret)
 		bpf_iter_fini_seq_net(priv_data);
 
+	iter->state.bucket = -1;
+
 	return ret;
 }