On Wed, 28 Oct 2020 12:00:39 +0100 Karsten Graul wrote:
> To allow better problem diagnosis the return codes for SMC-Dv2 are
> improved by this patch. A few more CLC DECLINE codes are defined and
> sent to the peer when an SMC connection cannot be established.
> There are now multiple SMC variations that are offered by the client and
> the server may encounter problems to initialize all of them.
> Because only one diagnosis code can be sent to the client the decision
> was made to send the first code that was encountered. Because the server
> tries the variations in the order of importance (SMC-Dv2, SMC-D, SMC-R)
> this makes sure that the diagnosis code of the most important variation
> is sent.
>
> Signed-off-by: Karsten Graul <kgr...@linux.ibm.com>
> ---
> net/smc/af_smc.c | 61 +++++++++++++++++++++++++++++++---------------
> net/smc/smc_clc.h | 5 ++++
> net/smc/smc_core.h | 1 +
> 3 files changed, 47 insertions(+), 20 deletions(-)
>
> diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
> index 82be0bd0f6e8..5414704f4cac 100644
> --- a/net/smc/af_smc.c
> +++ b/net/smc/af_smc.c
> @@ -1346,6 +1346,7 @@ static int smc_listen_v2_check(struct smc_sock *new_smc,
> {
> struct smc_clc_smcd_v2_extension *pclc_smcd_v2_ext;
> struct smc_clc_v2_extension *pclc_v2_ext;
> + int rc;
>
> ini->smc_type_v1 = pclc->hdr.typev1;
> ini->smc_type_v2 = pclc->hdr.typev2;
> @@ -1353,29 +1354,30 @@ static int smc_listen_v2_check(struct smc_sock
> *new_smc,
> if (pclc->hdr.version > SMC_V1)
> ini->smcd_version |=
> ini->smc_type_v2 != SMC_TYPE_N ? SMC_V2 : 0;
> + if (!(ini->smcd_version & SMC_V2)) {
> + rc = SMC_CLC_DECL_PEERNOSMC;
> + goto out;
> + }
> if (!smc_ism_v2_capable) {
> ini->smcd_version &= ~SMC_V2;
> + rc = SMC_CLC_DECL_NOISM2SUPP;
> goto out;
> }
> pclc_v2_ext = smc_get_clc_v2_ext(pclc);
> if (!pclc_v2_ext) {
> ini->smcd_version &= ~SMC_V2;
> + rc = SMC_CLC_DECL_NOV2EXT;
> goto out;
> }
> pclc_smcd_v2_ext = smc_get_clc_smcd_v2_ext(pclc_v2_ext);
> - if (!pclc_smcd_v2_ext)
> + if (!pclc_smcd_v2_ext) {
> ini->smcd_version &= ~SMC_V2;
> + rc = SMC_CLC_DECL_NOV2DEXT;
> + }
>
> out:
> - if (!ini->smcd_version) {
> - if (pclc->hdr.typev1 == SMC_TYPE_B ||
> - pclc->hdr.typev2 == SMC_TYPE_B)
> - return SMC_CLC_DECL_NOSMCDEV;
> - if (pclc->hdr.typev1 == SMC_TYPE_D ||
> - pclc->hdr.typev2 == SMC_TYPE_D)
> - return SMC_CLC_DECL_NOSMCDDEV;
> - return SMC_CLC_DECL_NOSMCRDEV;
> - }
> + if (!ini->smcd_version)
> + return rc;
Is rc guaranteed to be initialized? Looks like ini->smcd_version could
possibly start out as 0, no?
>
> return 0;
> }
> @@ -1473,6 +1475,12 @@ static void smc_check_ism_v2_match(struct
> smc_init_info *ini,
> }
> }
> @@ -1630,10 +1647,14 @@ static int smc_listen_find_device(struct smc_sock
> *new_smc,
> return 0;
>
> if (pclc->hdr.typev1 == SMC_TYPE_D)
> - return SMC_CLC_DECL_NOSMCDDEV; /* skip RDMA and decline */
> + /* skip RDMA and decline */
> + return ini->rc ?: SMC_CLC_DECL_NOSMCDDEV;
>
> /* check if RDMA is available */
> - return smc_find_rdma_v1_device_serv(new_smc, pclc, ini);
> + rc = smc_find_rdma_v1_device_serv(new_smc, pclc, ini);
> + smc_find_ism_store_rc(rc, ini);
> +
> + return (!rc) ? 0 : ini->rc;
Since I'm asking questions anyway - isn't this equivalent to
return ini->rc;
since there's call to
smc_find_ism_store_rc(rc, ini);
right above?
