Re: [PATCH 6.5 159/241] net/smc: support smc release version negotiation in clc handshake

Hi, Greg.

[PATCH 6.5 159/241] net/smc: support smc release version negotiation in clc handshake [PATCH 6.5 160/241] net/smc: support smc v2.x features validate

The above two patches should not backport to stable tree 6.5, which may result in unexpected fallback if communication between 6.6 and 6.5(with these two patch) via SMC-R v2.1. The above two patches should not exist individually without the patch 7f0620b9(net/smc: support max connections per lgr negotiation) and the patch 69b888e3(net/smc: support max links per lgr negotiation in clc handshake).

The patch c68681ae46ea ("net/smc: fix smc clc failed issue when netdevice not in init_net") does not rely the feature SMC-R v2.1. But I think it may have conflict here when backport to stable tree 6.5:

@@ -1201,6 +1201,7 @@ static int smc_connect_rdma_v2_prepare(struct smc_sock *smc, (struct smc_clc_msg_accept_confirm_v2 *)aclc; struct smc_clc_first_contact_ext *fce = smc_get_clc_first_contact_ext(clc_v2, false); --conflict here + struct net *net = sock_net(&smc->sk);

I think it is better to resolve the confilict rather than backport more patches. The resolution of the conflict should be like:

@@ -1201,6 +1201,7 @@ static int smc_connect_rdma_v2_prepare(struct smc_sock *smc, (struct smc_clc_msg_accept_confirm_v2 *)aclc; struct smc_clc_first_contact_ext *fce = (struct smc_clc_first_contact_ext *) (((u8 *)clc_v2) + sizeof(*clc_v2)); --replace the line smc_get_clc_first_contact_ext(clc_v2, false); + struct net *net = sock_net(&smc->sk);

Thanks, Guangguan Wang

On 2023/10/23 18:55, Greg Kroah-Hartman wrote:

6.5-stable review patch. If anyone has any objections, please let me know.

---

From: Guangguan Wang guangguan.wang@linux.alibaba.com

[ Upstream commit 1e700948c9db0d09f691f715e8f4b947e51e35b5 ]

Support smc release version negotiation in clc handshake based on SMC v2, where no negotiation process for different releases, but for different versions. The latest smc release version was updated to v2.1. And currently there are two release versions of SMCv2, v2.0 and v2.1. In the release version negotiation, client sends the preferred release version by CLC Proposal Message, server makes decision for which release version to use based on the client preferred release version and self-supported release version (here choose the minimum release version of the client preferred and server latest supported), then the decision returns to client by CLC Accept Message. Client confirms the decision by CLC Confirm Message.

Client Server Proposal(preferred release version) ------------------------------------>

  Accept(accpeted release version)

min(client preferred, server latest supported) <------------------------------------

  Confirm(accpeted release version)
 ------------------------------------>

Signed-off-by: Guangguan Wang guangguan.wang@linux.alibaba.com Reviewed-by: Tony Lu tonylu@linux.alibaba.com Reviewed-by: Jan Karcher jaka@linux.ibm.com Signed-off-by: David S. Miller davem@davemloft.net Stable-dep-of: c68681ae46ea ("net/smc: fix smc clc failed issue when netdevice not in init_net") Signed-off-by: Sasha Levin sashal@kernel.org

---

net/smc/af_smc.c | 21 +++++++++++++++++---- net/smc/smc.h | 5 ++++- net/smc/smc_clc.c | 14 +++++++------- net/smc/smc_clc.h | 23 ++++++++++++++++++++++- net/smc/smc_core.h | 1 + 5 files changed, 51 insertions(+), 13 deletions(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index c0e4e587b4994..077e5864fc441 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -1198,8 +1198,7 @@ static int smc_connect_rdma_v2_prepare(struct smc_sock *smc, struct smc_clc_msg_accept_confirm_v2 *clc_v2 = (struct smc_clc_msg_accept_confirm_v2 *)aclc; struct smc_clc_first_contact_ext *fce =

• (struct smc_clc_first_contact_ext *)
  

• 	(((u8 *)clc_v2) + sizeof(*clc_v2));
  

• smc_get_clc_first_contact_ext(clc_v2, false);
  

if (!ini->first_contact_peer || aclc->hdr.version == SMC_V1) return 0; @@ -1218,6 +1217,9 @@ static int smc_connect_rdma_v2_prepare(struct smc_sock *smc, return SMC_CLC_DECL_NOINDIRECT; } }

• ini->release_nr = fce->release;
• return 0;

} @@ -1386,6 +1388,13 @@ static int smc_connect_ism(struct smc_sock *smc, struct smc_clc_msg_accept_confirm_v2 *aclc_v2 = (struct smc_clc_msg_accept_confirm_v2 *)aclc;

• if (ini->first_contact_peer) {
  

• 	struct smc_clc_first_contact_ext *fce =
  

• 		smc_get_clc_first_contact_ext(aclc_v2, true);
  

• 	ini->release_nr = fce->release;
  

• }
  

• rc = smc_v2_determine_accepted_chid(aclc_v2, ini); if (rc) return rc;

@@ -1420,7 +1429,7 @@ static int smc_connect_ism(struct smc_sock *smc, } rc = smc_clc_send_confirm(smc, ini->first_contact_local,

• 		  aclc->hdr.version, eid, NULL);
  

• 		  aclc->hdr.version, eid, ini);
  

  if (rc) goto connect_abort; mutex_unlock(&smc_server_lgr_pending);

@@ -1996,6 +2005,10 @@ static int smc_listen_v2_check(struct smc_sock *new_smc, } }

• ini->release_nr = pclc_v2_ext->hdr.flag.release;
• if (pclc_v2_ext->hdr.flag.release > SMC_RELEASE)

• ini->release_nr = SMC_RELEASE;
  

out: if (!ini->smcd_version && !ini->smcr_version) return rc; @@ -2443,7 +2456,7 @@ static void smc_listen_work(struct work_struct *work) /* send SMC Accept CLC message */ accept_version = ini->is_smcd ? ini->smcd_version : ini->smcr_version; rc = smc_clc_send_accept(new_smc, ini->first_contact_local,

• 		 accept_version, ini->negotiated_eid);
  

• 		 accept_version, ini->negotiated_eid, ini);
  

  if (rc) goto out_unlock;

diff --git a/net/smc/smc.h b/net/smc/smc.h index 1f2b912c43d10..24745fde4ac26 100644 --- a/net/smc/smc.h +++ b/net/smc/smc.h @@ -21,7 +21,10 @@ #define SMC_V1 1 /* SMC version V1 */ #define SMC_V2 2 /* SMC version V2 */ -#define SMC_RELEASE 0

+#define SMC_RELEASE_0 0 +#define SMC_RELEASE_1 1 +#define SMC_RELEASE SMC_RELEASE_1 /* the latest release version */ #define SMCPROTO_SMC 0 /* SMC protocol, IPv4 */ #define SMCPROTO_SMC6 1 /* SMC protocol, IPv6 */ diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c index c90d9e5dda540..fb0be0817e8a5 100644 --- a/net/smc/smc_clc.c +++ b/net/smc/smc_clc.c @@ -420,11 +420,11 @@ smc_clc_msg_decl_valid(struct smc_clc_msg_decline *dclc) return true; } -static void smc_clc_fill_fce(struct smc_clc_first_contact_ext *fce, int *len) +static void smc_clc_fill_fce(struct smc_clc_first_contact_ext *fce, int *len, int release_nr) { memset(fce, 0, sizeof(*fce)); fce->os_type = SMC_CLC_OS_LINUX;

• fce->release = SMC_RELEASE;

• fce->release = release_nr; memcpy(fce->hostname, smc_hostname, sizeof(smc_hostname)); (*len) += sizeof(*fce);

} @@ -1019,7 +1019,7 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc, memcpy(clc_v2->d1.eid, eid, SMC_MAX_EID_LEN); len = SMCD_CLC_ACCEPT_CONFIRM_LEN_V2; if (first_contact)

• 		smc_clc_fill_fce(&fce, &len);
  

• 		smc_clc_fill_fce(&fce, &len, ini->release_nr);
  clc_v2->hdr.length = htons(len);
  

  } memcpy(trl.eyecatcher, SMCD_EYECATCHER,

@@ -1063,10 +1063,10 @@ static int smc_clc_send_confirm_accept(struct smc_sock *smc, memcpy(clc_v2->r1.eid, eid, SMC_MAX_EID_LEN); len = SMCR_CLC_ACCEPT_CONFIRM_LEN_V2; if (first_contact) {

• 		smc_clc_fill_fce(&fce, &len);
  

• 		smc_clc_fill_fce(&fce, &len, ini->release_nr);
  	fce.v2_direct = !link->lgr->uses_gateway;
  	memset(&gle, 0, sizeof(gle));
  

• 		if (ini && clc->hdr.type == SMC_CLC_CONFIRM) {
  

• 		if (clc->hdr.type == SMC_CLC_CONFIRM) {
  		gle.gid_cnt = ini->smcrv2.gidlist.len;
  		len += sizeof(gle);
  		len += gle.gid_cnt * sizeof(gle.gid[0]);
  

@@ -1141,7 +1141,7 @@ int smc_clc_send_confirm(struct smc_sock *smc, bool clnt_first_contact, /* send CLC ACCEPT message across internal TCP socket */ int smc_clc_send_accept(struct smc_sock *new_smc, bool srv_first_contact,

• 	u8 version, u8 *negotiated_eid)
  

• 	u8 version, u8 *negotiated_eid, struct smc_init_info *ini)
  

{ struct smc_clc_msg_accept_confirm_v2 aclc_v2; int len; @@ -1149,7 +1149,7 @@ int smc_clc_send_accept(struct smc_sock *new_smc, bool srv_first_contact, memset(&aclc_v2, 0, sizeof(aclc_v2)); aclc_v2.hdr.type = SMC_CLC_ACCEPT; len = smc_clc_send_confirm_accept(new_smc, &aclc_v2, srv_first_contact,

• 			  version, negotiated_eid, NULL);
  

• 			  version, negotiated_eid, ini);
  

  if (len < ntohs(aclc_v2.hdr.length)) len = len >= 0 ? -EPROTO : -new_smc->clcsock->sk->sk_err;

diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h index 5fee545c9a109..b923e89acafb0 100644 --- a/net/smc/smc_clc.h +++ b/net/smc/smc_clc.h @@ -370,6 +370,27 @@ smc_get_clc_smcd_v2_ext(struct smc_clc_v2_extension *prop_v2ext) ntohs(prop_v2ext->hdr.smcd_v2_ext_offset)); } +static inline struct smc_clc_first_contact_ext * +smc_get_clc_first_contact_ext(struct smc_clc_msg_accept_confirm_v2 *clc_v2,

• 	      bool is_smcd)
  

+{

• int clc_v2_len;
• if (clc_v2->hdr.version == SMC_V1 ||

•    !(clc_v2->hdr.typev2 & SMC_FIRST_CONTACT_MASK))
  

• return NULL;
  

• if (is_smcd)

• clc_v2_len =
  

• 	offsetofend(struct smc_clc_msg_accept_confirm_v2, d1);
  

• else

• clc_v2_len =
  

• 	offsetofend(struct smc_clc_msg_accept_confirm_v2, r1);
  

• return (struct smc_clc_first_contact_ext *)(((u8 *)clc_v2) +

• 				    clc_v2_len);
  

+}

struct smcd_dev; struct smc_init_info; @@ -382,7 +403,7 @@ int smc_clc_send_proposal(struct smc_sock *smc, struct smc_init_info *ini); int smc_clc_send_confirm(struct smc_sock *smc, bool clnt_first_contact, u8 version, u8 *eid, struct smc_init_info *ini); int smc_clc_send_accept(struct smc_sock *smc, bool srv_first_contact,

• 	u8 version, u8 *negotiated_eid);
  

• 	u8 version, u8 *negotiated_eid, struct smc_init_info *ini);
  

void smc_clc_init(void) __init; void smc_clc_exit(void); void smc_clc_get_hostname(u8 **host); diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h index 1645fba0d2d38..5bbc16f851e05 100644 --- a/net/smc/smc_core.h +++ b/net/smc/smc_core.h @@ -374,6 +374,7 @@ struct smc_init_info { u8 is_smcd; u8 smc_type_v1; u8 smc_type_v2;

• u8 release_nr; u8 first_contact_peer; u8 first_contact_local; unsigned short vlan_id;