[PATCH net-next 14/14] net/smc: CLC decline - V2 enhancements

Karsten Graul
2020-09-26T10:44:56Z

This patch covers the small SMCD version 2 changes for CLC decline.

Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
---
net/smc/af_smc.c | 27 +++++++++++++++++----------
net/smc/smc_clc.c | 5 +++--
net/smc/smc_clc.h | 13 ++++++++++---
3 files changed, 30 insertions(+), 15 deletions(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 3007f9c36d2c..ec933565d912 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -531,7 +531,8 @@ static int smc_connect_fallback(struct smc_sock *smc, int reason_code)
}

/* decline and fall back during connect */
-static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code)
+static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code,
+ u8 version)
{
int rc;

@@ -541,7 +542,7 @@ static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code)
return reason_code;
}
if (reason_code != SMC_CLC_DECL_PEERDECL) {
- rc = smc_clc_send_decline(smc, reason_code);
+ rc = smc_clc_send_decline(smc, reason_code, version);
if (rc < 0) {
if (smc->sk.sk_state == SMC_INIT)
sock_put(&smc->sk); /* passive closing */
@@ -901,6 +902,7 @@ static int smc_connect_check_aclc(struct smc_init_info *ini,
/* perform steps before actually connecting */
static int __smc_connect(struct smc_sock *smc)
{
+ u8 version = smc_ism_v2_capable ? SMC_V2 : SMC_V1;
struct smc_clc_msg_accept_confirm_v2 *aclc2;
struct smc_clc_msg_accept_confirm *aclc;
struct smc_init_info *ini = NULL;
@@ -914,13 +916,15 @@ static int __smc_connect(struct smc_sock *smc)
if (!tcp_sk(smc->clcsock->sk)->syn_smc)
return smc_connect_fallback(smc, SMC_CLC_DECL_PEERNOSMC);

- /* IPSec connections opt out of SMC-R optimizations */
+ /* IPSec connections opt out of SMC optimizations */
if (using_ipsec(smc))
- return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC);
+ return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC,
+ version);

ini = kzalloc(sizeof(*ini), GFP_KERNEL);
if (!ini)
- return smc_connect_decline_fallback(smc, SMC_CLC_DECL_MEM);
+ return smc_connect_decline_fallback(smc, SMC_CLC_DECL_MEM,
+ version);

ini->smcd_version = SMC_V1;
ini->smcd_version |= smc_ism_v2_capable ? SMC_V2 : 0;
@@ -956,6 +960,7 @@ static int __smc_connect(struct smc_sock *smc)

/* check if smc modes and versions of CLC proposal and accept match */
rc = smc_connect_check_aclc(ini, aclc);
+ version = aclc->hdr.version == SMC_V1 ? SMC_V1 : version;
if (rc)
goto vlan_cleanup;

@@ -977,7 +982,7 @@ static int __smc_connect(struct smc_sock *smc)
kfree(buf);
fallback:
kfree(ini);
- return smc_connect_decline_fallback(smc, rc);
+ return smc_connect_decline_fallback(smc, rc, version);
}

static void smc_connect_work(struct work_struct *work)
@@ -1293,7 +1298,7 @@ static void smc_listen_out_err(struct smc_sock *new_smc)

/* listen worker: decline and fall back if possible */
static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
- struct smc_init_info *ini)
+ struct smc_init_info *ini, u8 version)
{
/* RDMA setup failed, switch back to TCP */
if (ini->first_contact_local)
@@ -1307,7 +1312,7 @@ static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
smc_switch_to_fallback(new_smc);
new_smc->fallback_rsn = reason_code;
if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) {
- if (smc_clc_send_decline(new_smc, reason_code) < 0) {
+ if (smc_clc_send_decline(new_smc, reason_code, version) < 0) {
smc_listen_out_err(new_smc);
return;
}
@@ -1638,6 +1643,7 @@ static void smc_listen_work(struct work_struct *work)
{
struct smc_sock *new_smc = container_of(work, struct smc_sock,
smc_listen_work);
+ u8 version = smc_ism_v2_capable ? SMC_V2 : SMC_V1;
struct socket *newclcsock = new_smc->clcsock;
struct smc_clc_msg_accept_confirm_v2 *cclc2;
struct smc_clc_msg_accept_confirm *cclc;
@@ -1675,8 +1681,9 @@ static void smc_listen_work(struct work_struct *work)
SMC_CLC_PROPOSAL, CLC_WAIT_TIME);
if (rc)
goto out_decl;
+ version = pclc->hdr.version == SMC_V1 ? SMC_V1 : version;

- /* IPSec connections opt out of SMC-R optimizations */
+ /* IPSec connections opt out of SMC optimizations */
if (using_ipsec(new_smc)) {
rc = SMC_CLC_DECL_IPSEC;
goto out_decl;
@@ -1741,7 +1748,7 @@ static void smc_listen_work(struct work_struct *work)
out_unlock:
mutex_unlock(&smc_server_lgr_pending);
out_decl:
- smc_listen_decline(new_smc, rc, ini);
+ smc_listen_decline(new_smc, rc, ini, version);
out_free:
kfree(ini);
kfree(buf);
diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index 6762291b3940..09e36462ec0d 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -443,7 +443,7 @@ int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
}

/* send CLC DECLINE message across internal TCP socket */
-int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info)
+int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info, u8 version)
{
struct smc_clc_msg_decline dclc;
struct msghdr msg;
@@ -454,7 +454,8 @@ int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info)
memcpy(dclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
dclc.hdr.type = SMC_CLC_DECLINE;
dclc.hdr.length = htons(sizeof(struct smc_clc_msg_decline));
- dclc.hdr.version = SMC_V1;
+ dclc.hdr.version = version;
+ dclc.os_type = version == SMC_V1 ? 0 : SMC_CLC_OS_LINUX;
dclc.hdr.typev2 = (peer_diag_info == SMC_CLC_DECL_SYNCERR) ?
SMC_FIRST_CONTACT_MASK : 0;
if ((!smc->conn.lgr || !smc->conn.lgr->is_smcd) &&
diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index 92179d955f59..b3f46ab79e47 100644
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -244,8 +244,15 @@ struct smc_clc_msg_decline { /* clc decline message */
struct smc_clc_msg_hdr hdr;
u8 id_for_peer[SMC_SYSTEMID_LEN]; /* sender peer_id */
__be32 peer_diagnosis; /* diagnosis information */
- u8 reserved2[4];
- struct smc_clc_msg_trail trl; /* eye catcher "SMCR" EBCDIC */
+#if defined(__BIG_ENDIAN_BITFIELD)
+ u8 os_type : 4,
+ reserved : 4;
+#elif defined(__LITTLE_ENDIAN_BITFIELD)
+ u8 reserved : 4,
+ os_type : 4;
+#endif
+ u8 reserved2[3];
+ struct smc_clc_msg_trail trl; /* eye catcher "SMCD" or "SMCR" EBCDIC */
} __aligned(4);

/* determine start of the prefix area within the proposal message */
@@ -315,7 +322,7 @@ int smc_clc_prfx_match(struct socket *clcsock,
struct smc_clc_msg_proposal_prefix *prop);
int smc_clc_wait_msg(struct smc_sock *smc, void *buf, int buflen,
u8 expected_type, unsigned long timeout);
-int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info);
+int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info, u8 version);
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);
--
2.17.1