In the smc_listen_work(), if smc_listen_prfx_check() failed,
the real reason: SMC_CLC_DECL_DIFFPREFIX was dropped, and
SMC_CLC_DECL_NOSMCDEV was returned.
Althrough this is also kind of SMC_CLC_DECL_NOSMCDEV, but return
the real reason is much friendly for debugging.
Fixes: e49300a6bf62 ("net/smc: add listen processing for SMC-Rv2")
Signed-off-by: Dust Li <[email protected]>
---
net/smc/af_smc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index bacdd971615e..21d4476b937b 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -2361,7 +2361,7 @@ static int smc_listen_find_device(struct smc_sock *new_smc,
smc_find_ism_store_rc(rc, ini);
return (!rc) ? 0 : ini->rc;
}
- return SMC_CLC_DECL_NOSMCDEV;
+ return prfx_rc;
}
/* listen worker: finish RDMA setup */
--
2.19.1.6.gb485710b
On 12.10.23 14:37, Dust Li wrote:
> In the smc_listen_work(), if smc_listen_prfx_check() failed,
> the real reason: SMC_CLC_DECL_DIFFPREFIX was dropped, and
> SMC_CLC_DECL_NOSMCDEV was returned.
>
> Althrough this is also kind of SMC_CLC_DECL_NOSMCDEV, but return
> the real reason is much friendly for debugging.
>
> Fixes: e49300a6bf62 ("net/smc: add listen processing for SMC-Rv2")
> Signed-off-by: Dust Li <[email protected]>
As you point out the current code is not really wrong. So I am not sure,
whether this should be a fix for net, or rather a debug improvement for
net-next.
> ---
> net/smc/af_smc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
> index bacdd971615e..21d4476b937b 100644
> --- a/net/smc/af_smc.c
> +++ b/net/smc/af_smc.c
> @@ -2361,7 +2361,7 @@ static int smc_listen_find_device(struct smc_sock *new_smc,
> smc_find_ism_store_rc(rc, ini);
> return (!rc) ? 0 : ini->rc;
> }
> - return SMC_CLC_DECL_NOSMCDEV;
> + return prfx_rc;
> }
>
> /* listen worker: finish RDMA setup */
For the code change:
Reviewed-by: Alexandra Winter <[email protected]>
On 12.10.23 15:05, Alexandra Winter wrote:
>
>
> On 12.10.23 14:37, Dust Li wrote:
>> In the smc_listen_work(), if smc_listen_prfx_check() failed,
>> the real reason: SMC_CLC_DECL_DIFFPREFIX was dropped, and
>> SMC_CLC_DECL_NOSMCDEV was returned.
>>
>> Althrough this is also kind of SMC_CLC_DECL_NOSMCDEV, but return
>> the real reason is much friendly for debugging.
>>
>> Fixes: e49300a6bf62 ("net/smc: add listen processing for SMC-Rv2")
>> Signed-off-by: Dust Li <[email protected]>
>
> As you point out the current code is not really wrong. So I am not sure,
> whether this should be a fix for net, or rather a debug improvement for
> net-next.
> The return code was not precise, and since we do have already a more
appropriate return code to use. IMO, it was wrong. I'm for net.
Reviewed-by: Wenjia Zhang <[email protected]>
On Thu, Oct 12, 2023 at 03:05:20PM +0200, Alexandra Winter wrote:
>
>
>On 12.10.23 14:37, Dust Li wrote:
>> In the smc_listen_work(), if smc_listen_prfx_check() failed,
>> the real reason: SMC_CLC_DECL_DIFFPREFIX was dropped, and
>> SMC_CLC_DECL_NOSMCDEV was returned.
>>
>> Althrough this is also kind of SMC_CLC_DECL_NOSMCDEV, but return
>> the real reason is much friendly for debugging.
>>
>> Fixes: e49300a6bf62 ("net/smc: add listen processing for SMC-Rv2")
>> Signed-off-by: Dust Li <[email protected]>
>
>As you point out the current code is not really wrong. So I am not sure,
>whether this should be a fix for net, or rather a debug improvement for
>net-next.
To be honest, I was a bit conflicted which branch should this go for.
But after checking the code before e49300a6bf62 ("net/smc: add listen
processing for SMC-Rv2"), I discovered the previous behavior was to return
SMC_CLC_DECL_DIFFPREFIX. Therefor, I have decided it should be
considered a fix.
I should have memtioned this in the commit message.
Best regards,
Dust
>
>> ---
>> net/smc/af_smc.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
>> index bacdd971615e..21d4476b937b 100644
>> --- a/net/smc/af_smc.c
>> +++ b/net/smc/af_smc.c
>> @@ -2361,7 +2361,7 @@ static int smc_listen_find_device(struct smc_sock *new_smc,
>> smc_find_ism_store_rc(rc, ini);
>> return (!rc) ? 0 : ini->rc;
>> }
>> - return SMC_CLC_DECL_NOSMCDEV;
>> + return prfx_rc;
>> }
>>
>> /* listen worker: finish RDMA setup */
>
>For the code change:
>Reviewed-by: Alexandra Winter <[email protected]>
On 2023/10/12 20:37, Dust Li wrote:
> In the smc_listen_work(), if smc_listen_prfx_check() failed,
> the real reason: SMC_CLC_DECL_DIFFPREFIX was dropped, and
> SMC_CLC_DECL_NOSMCDEV was returned.
>
> Althrough this is also kind of SMC_CLC_DECL_NOSMCDEV, but return
> the real reason is much friendly for debugging.
>
> Fixes: e49300a6bf62 ("net/smc: add listen processing for SMC-Rv2")
> Signed-off-by: Dust Li <[email protected]>
> ---
> net/smc/af_smc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
> index bacdd971615e..21d4476b937b 100644
> --- a/net/smc/af_smc.c
> +++ b/net/smc/af_smc.c
> @@ -2361,7 +2361,7 @@ static int smc_listen_find_device(struct smc_sock *new_smc,
> smc_find_ism_store_rc(rc, ini);
> return (!rc) ? 0 : ini->rc;
> }
> - return SMC_CLC_DECL_NOSMCDEV;
> + return prfx_rc;
> }
>
> /* listen worker: finish RDMA setup */
Inspired by this fix, I am thinking that is it suitable to store the first
decline reason rather than real decline reason that caused the return of
smc_listen_find_device()?
For example, when running SMC between two peers with only RDMA devices. Then
in smc_listen_find_device():
1. call smc_find_ism_v2_device_serv() and find that no ISMv2 can be used.
the reason code will be stored as SMC_CLC_DECL_NOSMCD2DEV.
...
2. call smc_find_rdma_v1_device_serv() and find a RDMA device, but somehow
it failed to create buffers. It should inform users that SMC_CLC_DECL_MEM
occurs, but now the reason code returned SMC_CLC_DECL_NOSMCD2DEV.
I think users may be confused that why peer declines with this reason and
wonder what happens when trying to use SMC-R.
Thanks,
Wen Gu
On 2023/10/13 16:00, Wen Gu wrote:
>
>
> On 2023/10/12 20:37, Dust Li wrote:
>
>> In the smc_listen_work(), if smc_listen_prfx_check() failed,
>> the real reason: SMC_CLC_DECL_DIFFPREFIX was dropped, and
>> SMC_CLC_DECL_NOSMCDEV was returned.
>>
>> Althrough this is also kind of SMC_CLC_DECL_NOSMCDEV, but return
>> the real reason is much friendly for debugging.
>>
>> Fixes: e49300a6bf62 ("net/smc: add listen processing for SMC-Rv2")
>> Signed-off-by: Dust Li <[email protected]>
>> ---
>> net/smc/af_smc.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
>> index bacdd971615e..21d4476b937b 100644
>> --- a/net/smc/af_smc.c
>> +++ b/net/smc/af_smc.c
>> @@ -2361,7 +2361,7 @@ static int smc_listen_find_device(struct smc_sock *new_smc,
>> smc_find_ism_store_rc(rc, ini);
>> return (!rc) ? 0 : ini->rc;
>> }
>> - return SMC_CLC_DECL_NOSMCDEV;
>> + return prfx_rc;
>> }
>> /* listen worker: finish RDMA setup */
> Inspired by this fix, I am thinking that is it suitable to store the first
> decline reason rather than real decline reason that caused the return of
> smc_listen_find_device()?
>
> For example, when running SMC between two peers with only RDMA devices. Then
> in smc_listen_find_device():
>
> 1. call smc_find_ism_v2_device_serv() and find that no ISMv2 can be used.
> the reason code will be stored as SMC_CLC_DECL_NOSMCD2DEV.
>
> ...
>
> 2. call smc_find_rdma_v1_device_serv() and find a RDMA device, but somehow
> it failed to create buffers. It should inform users that SMC_CLC_DECL_MEM
> occurs, but now the reason code returned SMC_CLC_DECL_NOSMCD2DEV.
>
> I think users may be confused that why peer declines with this reason and
> wonder what happens when trying to use SMC-R.
Yes, the reason code here also makes me confused.
I think it is caused by not correctly using the function smc_find_ism_store_rc.
I'm working for the fix.
>
>
> Thanks,
> Wen Gu
>
Hello:
This patch was applied to netdev/net.git (main)
by Jakub Kicinski <[email protected]>:
On Thu, 12 Oct 2023 20:37:29 +0800 you wrote:
> In the smc_listen_work(), if smc_listen_prfx_check() failed,
> the real reason: SMC_CLC_DECL_DIFFPREFIX was dropped, and
> SMC_CLC_DECL_NOSMCDEV was returned.
>
> Althrough this is also kind of SMC_CLC_DECL_NOSMCDEV, but return
> the real reason is much friendly for debugging.
>
> [...]
Here is the summary with links:
- [net] net/smc: return the right falback reason when prefix checks fail
https://git.kernel.org/netdev/net/c/4abbd2e3c1db
You are awesome, thank you!
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