This patch should be squashed into "BPF packet scheduler" v3.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
---
 include/net/mptcp.h                           |  7 +---
 net/mptcp/bpf.c                               | 34 +++++++++----------
 net/mptcp/protocol.h                          |  1 +
 net/mptcp/sched.c                             | 21 +++++-------
 tools/testing/selftests/bpf/bpf_tcp_helpers.h |  8 ++---
 .../selftests/bpf/progs/mptcp_bpf_backup.c    |  6 ++--
 .../selftests/bpf/progs/mptcp_bpf_first.c     |  2 +-
 .../selftests/bpf/progs/mptcp_bpf_rr.c        |  8 ++---
 8 files changed, 36 insertions(+), 51 deletions(-)

diff --git a/include/net/mptcp.h b/include/net/mptcp.h
index 8a53583a9745..7af7fd48acc7 100644
--- a/include/net/mptcp.h
+++ b/include/net/mptcp.h
@@ -99,14 +99,9 @@ struct mptcp_out_options {
 #define MPTCP_SCHED_NAME_MAX	16
 #define MPTCP_SUBFLOWS_MAX	8
 
-struct mptcp_sched_subflow {
-	struct mptcp_subflow_context *context;
-	bool	is_scheduled;
-};
-
 struct mptcp_sched_data {
 	bool	reinject;
-	struct mptcp_sched_subflow subflows[MPTCP_SUBFLOWS_MAX];
+	struct mptcp_subflow_context *contexts[MPTCP_SUBFLOWS_MAX];
 };
 
 struct mptcp_sched_ops {
diff --git a/net/mptcp/bpf.c b/net/mptcp/bpf.c
index 4f4559d37f9e..0529e70d53b1 100644
--- a/net/mptcp/bpf.c
+++ b/net/mptcp/bpf.c
@@ -33,12 +33,6 @@ bpf_mptcp_sched_get_func_proto(enum bpf_func_id func_id,
 	return bpf_base_func_proto(func_id);
 }
 
-static size_t subflow_offset(int i)
-{
-	return offsetof(struct mptcp_sched_data, subflows) +
-	       i * sizeof(struct mptcp_sched_subflow);
-}
-
 static int bpf_mptcp_sched_btf_struct_access(struct bpf_verifier_log *log,
 					     const struct btf *btf,
 					     const struct btf_type *t, int off,
@@ -46,8 +40,7 @@ static int bpf_mptcp_sched_btf_struct_access(struct bpf_verifier_log *log,
 					     u32 *next_btf_id,
 					     enum bpf_type_flag *flag)
 {
-	size_t start, end, soff;
-	int i;
+	size_t end;
 
 	if (atype == BPF_READ) {
 		return btf_struct_access(log, btf, t, off, size, atype,
@@ -55,21 +48,26 @@ static int bpf_mptcp_sched_btf_struct_access(struct bpf_verifier_log *log,
 	}
 
 	if (t != mptcp_sched_type) {
-		bpf_log(log, "only access to mptcp_sched_data is supported\n");
+		bpf_log(log, "only access to mptcp_subflow_context is supported\n");
 		return -EACCES;
 	}
 
-	start = offsetof(struct mptcp_sched_subflow, is_scheduled);
-	end = offsetofend(struct mptcp_sched_subflow, is_scheduled);
+	switch (off) {
+	case offsetof(struct mptcp_subflow_context, scheduled):
+		end = offsetofend(struct mptcp_subflow_context, scheduled);
+		break;
+	default:
+		bpf_log(log, "no write support to mptcp_subflow_context at off %d\n", off);
+		return -EACCES;
+	}
 
-	for (i = 0; i < MPTCP_SUBFLOWS_MAX; i++) {
-		soff = subflow_offset(i);
-		if (off == soff + start && off + size <= soff + end)
-			return NOT_INIT; /* offsets match up with is_scheduled */
+	if (off + size > end) {
+		bpf_log(log, "access beyond mptcp_subflow_context at off %u size %u ended at %zu",
+			off, size, end);
+		return -EACCES;
 	}
 
-	bpf_log(log, "no write support to mptcp_sched_data at off %d\n", off);
-	return -EACCES;
+	return NOT_INIT;
 }
 
 static const struct bpf_verifier_ops bpf_mptcp_sched_verifier_ops = {
@@ -144,7 +142,7 @@ static int bpf_mptcp_sched_init(struct btf *btf)
 {
 	s32 type_id;
 
-	type_id = btf_find_by_name_kind(btf, "mptcp_sched_data",
+	type_id = btf_find_by_name_kind(btf, "mptcp_subflow_context",
 					BTF_KIND_STRUCT);
 	if (type_id < 0)
 		return -EINVAL;
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 8739794166d8..48c5261b7b15 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -469,6 +469,7 @@ struct mptcp_subflow_context {
 		valid_csum_seen : 1;        /* at least one csum validated */
 	enum mptcp_data_avail data_avail;
 	bool	mp_fail_response_expect;
+	bool	scheduled;
 	u32	remote_nonce;
 	u64	thmac;
 	u32	local_nonce;
diff --git a/net/mptcp/sched.c b/net/mptcp/sched.c
index 46396eed62d0..613b7005938c 100644
--- a/net/mptcp/sched.c
+++ b/net/mptcp/sched.c
@@ -101,15 +101,12 @@ static int mptcp_sched_data_init(struct mptcp_sock *msk, bool reinject,
 			pr_warn_once("too many subflows");
 			break;
 		}
-		data->subflows[i].context = subflow;
-		data->subflows[i].is_scheduled = 0;
-		i++;
+		WRITE_ONCE(subflow->scheduled, false);
+		data->contexts[i++] = subflow;
 	}
 
-	for (; i < MPTCP_SUBFLOWS_MAX; i++) {
-		data->subflows[i].context = NULL;
-		data->subflows[i].is_scheduled = 0;
-	}
+	for (; i < MPTCP_SUBFLOWS_MAX; i++)
+		data->contexts[i] = NULL;
 
 	return 0;
 }
@@ -136,9 +133,8 @@ struct sock *mptcp_sched_get_send(struct mptcp_sock *msk)
 	msk->sched->get_subflow(msk, &data);
 
 	for (i = 0; i < MPTCP_SUBFLOWS_MAX; i++) {
-		if (data.subflows[i].is_scheduled &&
-		    data.subflows[i].context) {
-			ssk = data.subflows[i].context->tcp_sock;
+		if (data.contexts[i] && READ_ONCE(data.contexts[i]->scheduled)) {
+			ssk = data.contexts[i]->tcp_sock;
 			msk->last_snd = ssk;
 			break;
 		}
@@ -166,9 +162,8 @@ struct sock *mptcp_sched_get_retrans(struct mptcp_sock *msk)
 	msk->sched->get_subflow(msk, &data);
 
 	for (i = 0; i < MPTCP_SUBFLOWS_MAX; i++) {
-		if (data.subflows[i].is_scheduled &&
-		    data.subflows[i].context) {
-			ssk = data.subflows[i].context->tcp_sock;
+		if (data.contexts[i] && READ_ONCE(data.contexts[i]->scheduled)) {
+			ssk = data.contexts[i]->tcp_sock;
 			msk->last_snd = ssk;
 			break;
 		}
diff --git a/tools/testing/selftests/bpf/bpf_tcp_helpers.h b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
index 480be2ea7d59..915f5735ebbd 100644
--- a/tools/testing/selftests/bpf/bpf_tcp_helpers.h
+++ b/tools/testing/selftests/bpf/bpf_tcp_helpers.h
@@ -237,17 +237,13 @@ struct mptcp_subflow_context {
 	__u32	token;
 	__u32	padding : 12,
 		backup : 1;
+	bool	scheduled;
 	struct	sock *tcp_sock;	    /* tcp sk backpointer */
 } __attribute__((preserve_access_index));
 
-struct mptcp_sched_subflow {
-	struct mptcp_subflow_context *context;
-	bool	is_scheduled;
-};
-
 struct mptcp_sched_data {
 	bool	reinject;
-	struct mptcp_sched_subflow subflows[MPTCP_SUBFLOWS_MAX];
+	struct mptcp_subflow_context *contexts[MPTCP_SUBFLOWS_MAX];
 };
 
 struct mptcp_sched_ops {
diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf_backup.c b/tools/testing/selftests/bpf/progs/mptcp_bpf_backup.c
index 4f394e971c03..088dbc4be99a 100644
--- a/tools/testing/selftests/bpf/progs/mptcp_bpf_backup.c
+++ b/tools/testing/selftests/bpf/progs/mptcp_bpf_backup.c
@@ -22,16 +22,16 @@ void BPF_STRUCT_OPS(bpf_backup_get_subflow, const struct mptcp_sock *msk,
 	int nr = 0;
 
 	for (int i = 0; i < MPTCP_SUBFLOWS_MAX; i++) {
-		if (!data->subflows[i].context)
+		if (!data->contexts[i])
 			break;
 
-		if (!data->subflows[i].context->backup) {
+		if (!data->contexts[i]->backup) {
 			nr = i;
 			break;
 		}
 	}
 
-	data->subflows[nr].is_scheduled = 1;
+	data->contexts[nr]->scheduled = 1;
 }
 
 SEC(".struct_ops")
diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf_first.c b/tools/testing/selftests/bpf/progs/mptcp_bpf_first.c
index 0baacd8b6426..5f866f51ac70 100644
--- a/tools/testing/selftests/bpf/progs/mptcp_bpf_first.c
+++ b/tools/testing/selftests/bpf/progs/mptcp_bpf_first.c
@@ -19,7 +19,7 @@ void BPF_PROG(mptcp_sched_first_release, const struct mptcp_sock *msk)
 void BPF_STRUCT_OPS(bpf_first_get_subflow, const struct mptcp_sock *msk,
 		    struct mptcp_sched_data *data)
 {
-	data->subflows[0].is_scheduled = 1;
+	data->contexts[0]->scheduled = 1;
 }
 
 SEC(".struct_ops")
diff --git a/tools/testing/selftests/bpf/progs/mptcp_bpf_rr.c b/tools/testing/selftests/bpf/progs/mptcp_bpf_rr.c
index de0d893e08b4..03c1032bc31a 100644
--- a/tools/testing/selftests/bpf/progs/mptcp_bpf_rr.c
+++ b/tools/testing/selftests/bpf/progs/mptcp_bpf_rr.c
@@ -22,11 +22,11 @@ void BPF_STRUCT_OPS(bpf_rr_get_subflow, const struct mptcp_sock *msk,
 	int nr = 0;
 
 	for (int i = 0; i < MPTCP_SUBFLOWS_MAX; i++) {
-		if (!msk->last_snd || !data->subflows[i].context)
+		if (!msk->last_snd || !data->contexts[i])
 			break;
 
-		if (data->subflows[i].context->tcp_sock == msk->last_snd) {
-			if (i + 1 == MPTCP_SUBFLOWS_MAX || !data->subflows[i + 1].context)
+		if (data->contexts[i]->tcp_sock == msk->last_snd) {
+			if (i + 1 == MPTCP_SUBFLOWS_MAX || !data->contexts[i + 1])
 				break;
 
 			nr = i + 1;
@@ -34,7 +34,7 @@ void BPF_STRUCT_OPS(bpf_rr_get_subflow, const struct mptcp_sock *msk,
 		}
 	}
 
-	data->subflows[nr].is_scheduled = 1;
+	data->contexts[nr]->scheduled = 1;
 }
 
 SEC(".struct_ops")
-- 
2.34.1

Hello,

On Sun, 2022-05-29 at 10:21 +0800, Geliang Tang wrote:
> This patch should be squashed into "BPF packet scheduler" v3.
> 
> Signed-off-by: Geliang Tang <geliang.tang@suse.com>

It looks like this patch should be squashed into several existing ones.
perhaps is simpler if you provied a git tree to pull the new revision
for this series ???

Thanks!

Paolo

> Hello,
>
> On Sun, 2022-05-29 at 10:21 +0800, Geliang Tang wrote:
> > This patch should be squashed into "BPF packet scheduler" v3.
> >
> > Signed-off-by: Geliang Tang <geliang.tang@suse.com>
>
> It looks like this patch should be squashed into several existing ones.
> perhaps is simpler if you provied a git tree to pull the new revision
> for this series ???

Thanks Paolo, I merged it in v4, and here's my git tree with full patches:
https://github.com/geliangtang/mptcp_net-next.

-Geliang

>
> Thanks!
>
> Paolo
>
>