2023-10-16 06:12:16

by Guangguan Wang

[permalink] [raw]
Subject: [PATCH net] net/smc: correct the reason code in smc_listen_find_device when fallback

The function smc_find_ism_store_rc is not only used for ism, so it is
reasonable to change the function name to smc_find_device_store_rc.

The ini->rc is used to store the last error happened when finding usable
ism or rdma device in smc_listen_find_device, and is set by calling smc_
find_device_store_rc. Once the ini->rc is assigned to an none-zero value,
the value can not be overwritten anymore. So the ini-rc should be set to
the error reason only when an error actually occurs.

When finding ISM/RDMA devices, device not found is not a real error, as
not all machine have ISM/RDMA devices. Failures after device found, when
initializing device or when initializing connection, is real errors, and
should be store in ini->rc.

SMC_CLC_DECL_DIFFPREFIX also is not a real error, as for SMC-RV2, it is
not require same prefix.

Signed-off-by: Guangguan Wang <[email protected]>
---
net/smc/af_smc.c | 23 +++++++++--------------
1 file changed, 9 insertions(+), 14 deletions(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index bacdd971615e..15d8ad7af75d 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -2121,7 +2121,7 @@ static void smc_check_ism_v2_match(struct smc_init_info *ini,
}
}

-static void smc_find_ism_store_rc(u32 rc, struct smc_init_info *ini)
+static void smc_find_device_store_rc(u32 rc, struct smc_init_info *ini)
{
if (!ini->rc)
ini->rc = rc;
@@ -2162,10 +2162,8 @@ static void smc_find_ism_v2_device_serv(struct smc_sock *new_smc,
}
mutex_unlock(&smcd_dev_list.mutex);

- if (!ini->ism_dev[0]) {
- smc_find_ism_store_rc(SMC_CLC_DECL_NOSMCD2DEV, ini);
+ if (!ini->ism_dev[0])
goto not_found;
- }

smc_ism_get_system_eid(&eid);
if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext,
@@ -2180,7 +2178,7 @@ static void smc_find_ism_v2_device_serv(struct smc_sock *new_smc,
ini->ism_selected = i;
rc = smc_listen_ism_init(new_smc, ini);
if (rc) {
- smc_find_ism_store_rc(rc, ini);
+ smc_find_device_store_rc(rc, ini);
/* try next active ISM device */
continue;
}
@@ -2213,11 +2211,12 @@ static void smc_find_ism_v1_device_serv(struct smc_sock *new_smc,
goto not_found;
ini->ism_selected = 0;
rc = smc_listen_ism_init(new_smc, ini);
- if (!rc)
+ if (!rc) {
+ smc_find_device_store_rc(rc, ini);
return; /* V1 ISM device found */
+ }

not_found:
- smc_find_ism_store_rc(rc, ini);
ini->smcd_version &= ~SMC_V1;
ini->ism_dev[0] = NULL;
ini->is_smcd = false;
@@ -2266,10 +2265,8 @@ static void smc_find_rdma_v2_device_serv(struct smc_sock *new_smc,
ini->smcrv2.saddr = new_smc->clcsock->sk->sk_rcv_saddr;
ini->smcrv2.daddr = smc_ib_gid_to_ipv4(smc_v2_ext->roce);
rc = smc_find_rdma_device(new_smc, ini);
- if (rc) {
- smc_find_ism_store_rc(rc, ini);
+ if (rc)
goto not_found;
- }
if (!ini->smcrv2.uses_gateway)
memcpy(ini->smcrv2.nexthop_mac, pclc->lcl.mac, ETH_ALEN);

@@ -2284,7 +2281,7 @@ static void smc_find_rdma_v2_device_serv(struct smc_sock *new_smc,
if (!rc)
return;
ini->smcr_version = smcr_version;
- smc_find_ism_store_rc(rc, ini);
+ smc_find_device_store_rc(rc, ini);

not_found:
ini->smcr_version &= ~SMC_V2;
@@ -2330,8 +2327,6 @@ static int smc_listen_find_device(struct smc_sock *new_smc,

/* check for matching IP prefix and subnet length (V1) */
prfx_rc = smc_listen_prfx_check(new_smc, pclc);
- if (prfx_rc)
- smc_find_ism_store_rc(prfx_rc, ini);

/* get vlan id from IP device */
if (smc_vlan_by_tcpsk(new_smc->clcsock, ini))
@@ -2358,7 +2353,7 @@ static int smc_listen_find_device(struct smc_sock *new_smc,
int rc;

rc = smc_find_rdma_v1_device_serv(new_smc, pclc, ini);
- smc_find_ism_store_rc(rc, ini);
+ smc_find_device_store_rc(rc, ini);
return (!rc) ? 0 : ini->rc;
}
return SMC_CLC_DECL_NOSMCDEV;
--
2.24.3 (Apple Git-128)


2023-10-17 08:08:12

by Dust Li

[permalink] [raw]
Subject: Re: [PATCH net] net/smc: correct the reason code in smc_listen_find_device when fallback

On Mon, Oct 16, 2023 at 02:11:53PM +0800, Guangguan Wang wrote:

Hi guangguan,

This patch doesn't apply clearly on net because it conflict with my
previous patch 4abbd2e3c1db(net/smc: return the right falback reason
when prefix checks fail), pls rebase.

>The function smc_find_ism_store_rc is not only used for ism, so it is
>reasonable to change the function name to smc_find_device_store_rc.
>
>The ini->rc is used to store the last error happened when finding usable
>ism or rdma device in smc_listen_find_device, and is set by calling smc_
>find_device_store_rc. Once the ini->rc is assigned to an none-zero value,
>the value can not be overwritten anymore. So the ini-rc should be set to
>the error reason only when an error actually occurs.
>
>When finding ISM/RDMA devices, device not found is not a real error, as
>not all machine have ISM/RDMA devices. Failures after device found, when
>initializing device or when initializing connection, is real errors, and
>should be store in ini->rc.
>
>SMC_CLC_DECL_DIFFPREFIX also is not a real error, as for SMC-RV2, it is
>not require same prefix.

I think it's better to seperate this patch into 2:
- one for changing the name from smc_find_ism_store_rc to smc_find_device_store_rc.
- one for fixing the return reason.

More comments below.

>
>Signed-off-by: Guangguan Wang <[email protected]>
>---
> net/smc/af_smc.c | 23 +++++++++--------------
> 1 file changed, 9 insertions(+), 14 deletions(-)
>
>diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
>index bacdd971615e..15d8ad7af75d 100644
>--- a/net/smc/af_smc.c
>+++ b/net/smc/af_smc.c
>@@ -2121,7 +2121,7 @@ static void smc_check_ism_v2_match(struct smc_init_info *ini,
> }
> }
>
>-static void smc_find_ism_store_rc(u32 rc, struct smc_init_info *ini)
>+static void smc_find_device_store_rc(u32 rc, struct smc_init_info *ini)
> {
> if (!ini->rc)
> ini->rc = rc;
>@@ -2162,10 +2162,8 @@ static void smc_find_ism_v2_device_serv(struct smc_sock *new_smc,
> }
> mutex_unlock(&smcd_dev_list.mutex);
>
>- if (!ini->ism_dev[0]) {
>- smc_find_ism_store_rc(SMC_CLC_DECL_NOSMCD2DEV, ini);
>+ if (!ini->ism_dev[0])
> goto not_found;
>- }
>
> smc_ism_get_system_eid(&eid);
> if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext,
>@@ -2180,7 +2178,7 @@ static void smc_find_ism_v2_device_serv(struct smc_sock *new_smc,
> ini->ism_selected = i;
> rc = smc_listen_ism_init(new_smc, ini);
> if (rc) {
>- smc_find_ism_store_rc(rc, ini);
>+ smc_find_device_store_rc(rc, ini);
> /* try next active ISM device */
> continue;
> }
>@@ -2213,11 +2211,12 @@ static void smc_find_ism_v1_device_serv(struct smc_sock *new_smc,
> goto not_found;
> ini->ism_selected = 0;
> rc = smc_listen_ism_init(new_smc, ini);
>- if (!rc)
>+ if (!rc) {
>+ smc_find_device_store_rc(rc, ini);

This smc_find_device_store_rc() seems useless when rc == 0 here ?

> return; /* V1 ISM device found */
>+ }
>
> not_found:
>- smc_find_ism_store_rc(rc, ini);
> ini->smcd_version &= ~SMC_V1;
> ini->ism_dev[0] = NULL;
> ini->is_smcd = false;
>@@ -2266,10 +2265,8 @@ static void smc_find_rdma_v2_device_serv(struct smc_sock *new_smc,
> ini->smcrv2.saddr = new_smc->clcsock->sk->sk_rcv_saddr;
> ini->smcrv2.daddr = smc_ib_gid_to_ipv4(smc_v2_ext->roce);
> rc = smc_find_rdma_device(new_smc, ini);
>- if (rc) {
>- smc_find_ism_store_rc(rc, ini);
>+ if (rc)
> goto not_found;
>- }
> if (!ini->smcrv2.uses_gateway)
> memcpy(ini->smcrv2.nexthop_mac, pclc->lcl.mac, ETH_ALEN);
>
>@@ -2284,7 +2281,7 @@ static void smc_find_rdma_v2_device_serv(struct smc_sock *new_smc,
> if (!rc)
> return;
> ini->smcr_version = smcr_version;
>- smc_find_ism_store_rc(rc, ini);
>+ smc_find_device_store_rc(rc, ini);
>
> not_found:
> ini->smcr_version &= ~SMC_V2;
>@@ -2330,8 +2327,6 @@ static int smc_listen_find_device(struct smc_sock *new_smc,
>
> /* check for matching IP prefix and subnet length (V1) */
> prfx_rc = smc_listen_prfx_check(new_smc, pclc);
>- if (prfx_rc)
>- smc_find_ism_store_rc(prfx_rc, ini);
>
> /* get vlan id from IP device */
> if (smc_vlan_by_tcpsk(new_smc->clcsock, ini))
>@@ -2358,7 +2353,7 @@ static int smc_listen_find_device(struct smc_sock *new_smc,
> int rc;
>
> rc = smc_find_rdma_v1_device_serv(new_smc, pclc, ini);
>- smc_find_ism_store_rc(rc, ini);
>+ smc_find_device_store_rc(rc, ini);
> return (!rc) ? 0 : ini->rc;
> }
> return SMC_CLC_DECL_NOSMCDEV;
>--
>2.24.3 (Apple Git-128)

2023-10-17 08:52:47

by Guangguan Wang

[permalink] [raw]
Subject: Re: [PATCH net] net/smc: correct the reason code in smc_listen_find_device when fallback



On 2023/10/17 15:37, Dust Li wrote:
> On Mon, Oct 16, 2023 at 02:11:53PM +0800, Guangguan Wang wrote:
>
> Hi guangguan,
>
> This patch doesn't apply clearly on net because it conflict with my
> previous patch 4abbd2e3c1db(net/smc: return the right falback reason
> when prefix checks fail), pls rebase.
>

This patch sent before the patch 4abbd2e3c1db applied. I will rebase it
in the next version.

>> The function smc_find_ism_store_rc is not only used for ism, so it is
>> reasonable to change the function name to smc_find_device_store_rc.
>>
>> The ini->rc is used to store the last error happened when finding usable
>> ism or rdma device in smc_listen_find_device, and is set by calling smc_
>> find_device_store_rc. Once the ini->rc is assigned to an none-zero value,
>> the value can not be overwritten anymore. So the ini-rc should be set to
>> the error reason only when an error actually occurs.
>>
>> When finding ISM/RDMA devices, device not found is not a real error, as
>> not all machine have ISM/RDMA devices. Failures after device found, when
>> initializing device or when initializing connection, is real errors, and
>> should be store in ini->rc.
>>
>> SMC_CLC_DECL_DIFFPREFIX also is not a real error, as for SMC-RV2, it is
>> not require same prefix.
>
> I think it's better to seperate this patch into 2:
> - one for changing the name from smc_find_ism_store_rc to smc_find_device_store_rc.
> - one for fixing the return reason.
>
> More comments below.
>
OK, I will seperate it.
>>
>> Signed-off-by: Guangguan Wang <[email protected]>

>> @@ -2213,11 +2211,12 @@ static void smc_find_ism_v1_device_serv(struct smc_sock *new_smc,
>> goto not_found;
>> ini->ism_selected = 0;
>> rc = smc_listen_ism_init(new_smc, ini);
>> - if (!rc)
>> + if (!rc) {
>> + smc_find_device_store_rc(rc, ini);
>
> This smc_find_device_store_rc() seems useless when rc == 0 here ?

Oh, I see. The code here should be:

rc = smc_listen_ism_init(new_smc, ini);
if (!rc)
return;
smc_find_device_store_rc(rc, ini);

not_found:
ini->smcd_version &= ~SMC_V1;
ini->ism_dev[0] = NULL;
ini->is_smcd = false;


Thanks,
Guangguan Wang.
>
>> return; /* V1 ISM device found */
>> + }
>>
>> not_found:
>> - smc_find_ism_store_rc(rc, ini);
>> ini->smcd_version &= ~SMC_V1;
>> ini->ism_dev[0] = NULL;
>> ini->is_smcd = false;