* Re: [PATCH 2/4] net/smc: Add netlink net namespace support [not found] ` <20211228130611.19124-3-tonylu@linux.alibaba.com> @ 2022-01-31 0:24 ` Dmitry V. Levin 2022-01-31 13:49 ` Karsten Graul 0 siblings, 1 reply; 5+ messages in thread From: Dmitry V. Levin @ 2022-01-31 0:24 UTC (permalink / raw) To: Tony Lu; +Cc: kgraul, kuba, davem, netdev, linux-s390, linux-rdma, linux-api On Tue, Dec 28, 2021 at 09:06:10PM +0800, Tony Lu wrote: > This adds net namespace ID to diag of linkgroup, helps us to distinguish > different namespaces, and net_cookie is unique in the whole system. > > Signed-off-by: Tony Lu <tonylu@linux.alibaba.com> > --- > include/uapi/linux/smc.h | 2 ++ > include/uapi/linux/smc_diag.h | 11 ++++++----- > net/smc/smc_core.c | 3 +++ > net/smc/smc_diag.c | 16 +++++++++------- > 4 files changed, 20 insertions(+), 12 deletions(-) > > diff --git a/include/uapi/linux/smc.h b/include/uapi/linux/smc.h > index 20f33b27787f..6c2874fd2c00 100644 > --- a/include/uapi/linux/smc.h > +++ b/include/uapi/linux/smc.h > @@ -119,6 +119,8 @@ enum { > SMC_NLA_LGR_R_CONNS_NUM, /* u32 */ > SMC_NLA_LGR_R_V2_COMMON, /* nest */ > SMC_NLA_LGR_R_V2, /* nest */ > + SMC_NLA_LGR_R_NET_COOKIE, /* u64 */ > + SMC_NLA_LGR_R_PAD, /* flag */ > __SMC_NLA_LGR_R_MAX, > SMC_NLA_LGR_R_MAX = __SMC_NLA_LGR_R_MAX - 1 > }; > diff --git a/include/uapi/linux/smc_diag.h b/include/uapi/linux/smc_diag.h > index 8cb3a6fef553..c7008d87f1a4 100644 > --- a/include/uapi/linux/smc_diag.h > +++ b/include/uapi/linux/smc_diag.h > @@ -84,11 +84,12 @@ struct smc_diag_conninfo { > /* SMC_DIAG_LINKINFO */ > > struct smc_diag_linkinfo { > - __u8 link_id; /* link identifier */ > - __u8 ibname[IB_DEVICE_NAME_MAX]; /* name of the RDMA device */ > - __u8 ibport; /* RDMA device port number */ > - __u8 gid[40]; /* local GID */ > - __u8 peer_gid[40]; /* peer GID */ > + __u8 link_id; /* link identifier */ > + __u8 ibname[IB_DEVICE_NAME_MAX]; /* name of the RDMA device */ > + __u8 ibport; /* RDMA device port number */ > + __u8 gid[40]; /* local GID */ > + __u8 peer_gid[40]; /* peer GID */ > + __aligned_u64 net_cookie; /* RDMA device net namespace */ > }; > > struct smc_diag_lgrinfo { I'm sorry but this is an ABI regression. Since struct smc_diag_lgrinfo contains an object of type "struct smc_diag_linkinfo", offset of all subsequent members of struct smc_diag_lgrinfo is changed by this patch. As result, applications compiled with the old version of struct smc_diag_linkinfo will receive garbage in struct smc_diag_lgrinfo.role if the kernel implements this new version of struct smc_diag_linkinfo. -- ldv ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH 2/4] net/smc: Add netlink net namespace support 2022-01-31 0:24 ` [PATCH 2/4] net/smc: Add netlink net namespace support Dmitry V. Levin @ 2022-01-31 13:49 ` Karsten Graul 2022-02-02 3:09 ` [PATCH] Partially revert "net/smc: Add netlink net namespace support" Dmitry V. Levin 0 siblings, 1 reply; 5+ messages in thread From: Karsten Graul @ 2022-01-31 13:49 UTC (permalink / raw) To: Dmitry V. Levin, Tony Lu Cc: kuba, davem, netdev, linux-s390, linux-rdma, linux-api On 31/01/2022 01:24, Dmitry V. Levin wrote: > On Tue, Dec 28, 2021 at 09:06:10PM +0800, Tony Lu wrote: >> This adds net namespace ID to diag of linkgroup, helps us to distinguish >> different namespaces, and net_cookie is unique in the whole system. >> > > I'm sorry but this is an ABI regression. > > Since struct smc_diag_lgrinfo contains an object of type "struct smc_diag_linkinfo", > offset of all subsequent members of struct smc_diag_lgrinfo is changed by > this patch. > > As result, applications compiled with the old version of struct smc_diag_linkinfo > will receive garbage in struct smc_diag_lgrinfo.role if the kernel implements > this new version of struct smc_diag_linkinfo. > Good catch! This patch adds 2 ways to provide the net_cookie to user space, one is over the new netlink interface, and the other is using the old smc_diag way. Imho to use the new netlink interface is good enough, there is no need to touch the smc_diag ABI. We already started adding new fields to the netlink interface only, this flexibility is the reason why we added this interface initially. So a patch that removes __aligned_u64 net_cookie; and .lnk[0].net_cookie = net->net_cookie, should solve the issue. Thoughts? ^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH] Partially revert "net/smc: Add netlink net namespace support" 2022-01-31 13:49 ` Karsten Graul @ 2022-02-02 3:09 ` Dmitry V. Levin 2022-02-02 7:26 ` Karsten Graul 2022-02-09 9:43 ` Tony Lu 0 siblings, 2 replies; 5+ messages in thread From: Dmitry V. Levin @ 2022-02-02 3:09 UTC (permalink / raw) To: Karsten Graul Cc: Tony Lu, kuba, davem, netdev, linux-s390, linux-rdma, linux-api The change of sizeof(struct smc_diag_linkinfo) by commit 79d39fc503b4 ("net/smc: Add netlink net namespace support") introduced an ABI regression: since struct smc_diag_lgrinfo contains an object of type "struct smc_diag_linkinfo", offset of all subsequent members of struct smc_diag_lgrinfo was changed by that change. As result, applications compiled with the old version of struct smc_diag_linkinfo will receive garbage in struct smc_diag_lgrinfo.role if the kernel implements this new version of struct smc_diag_linkinfo. Fix this regression by reverting the part of commit 79d39fc503b4 that changes struct smc_diag_linkinfo. After all, there is SMC_GEN_NETLINK interface which is good enough, so there is probably no need to touch the smc_diag ABI in the first place. Fixes: 79d39fc503b4 ("net/smc: Add netlink net namespace support") Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> --- include/uapi/linux/smc_diag.h | 11 +++++------ net/smc/smc_diag.c | 2 -- 2 files changed, 5 insertions(+), 8 deletions(-) diff --git a/include/uapi/linux/smc_diag.h b/include/uapi/linux/smc_diag.h index c7008d87f1a4..8cb3a6fef553 100644 --- a/include/uapi/linux/smc_diag.h +++ b/include/uapi/linux/smc_diag.h @@ -84,12 +84,11 @@ struct smc_diag_conninfo { /* SMC_DIAG_LINKINFO */ struct smc_diag_linkinfo { - __u8 link_id; /* link identifier */ - __u8 ibname[IB_DEVICE_NAME_MAX]; /* name of the RDMA device */ - __u8 ibport; /* RDMA device port number */ - __u8 gid[40]; /* local GID */ - __u8 peer_gid[40]; /* peer GID */ - __aligned_u64 net_cookie; /* RDMA device net namespace */ + __u8 link_id; /* link identifier */ + __u8 ibname[IB_DEVICE_NAME_MAX]; /* name of the RDMA device */ + __u8 ibport; /* RDMA device port number */ + __u8 gid[40]; /* local GID */ + __u8 peer_gid[40]; /* peer GID */ }; struct smc_diag_lgrinfo { diff --git a/net/smc/smc_diag.c b/net/smc/smc_diag.c index b8898c787d23..1fca2f90a9c7 100644 --- a/net/smc/smc_diag.c +++ b/net/smc/smc_diag.c @@ -146,13 +146,11 @@ static int __smc_diag_dump(struct sock *sk, struct sk_buff *skb, (req->diag_ext & (1 << (SMC_DIAG_LGRINFO - 1))) && !list_empty(&smc->conn.lgr->list)) { struct smc_link *link = smc->conn.lnk; - struct net *net = read_pnet(&link->smcibdev->ibdev->coredev.rdma_net); struct smc_diag_lgrinfo linfo = { .role = smc->conn.lgr->role, .lnk[0].ibport = link->ibport, .lnk[0].link_id = link->link_id, - .lnk[0].net_cookie = net->net_cookie, }; memcpy(linfo.lnk[0].ibname, -- ldv ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] Partially revert "net/smc: Add netlink net namespace support" 2022-02-02 3:09 ` [PATCH] Partially revert "net/smc: Add netlink net namespace support" Dmitry V. Levin @ 2022-02-02 7:26 ` Karsten Graul 2022-02-09 9:43 ` Tony Lu 1 sibling, 0 replies; 5+ messages in thread From: Karsten Graul @ 2022-02-02 7:26 UTC (permalink / raw) To: Dmitry V. Levin Cc: Tony Lu, kuba, davem, netdev, linux-s390, linux-rdma, linux-api On 02/02/2022 04:09, Dmitry V. Levin wrote: > The change of sizeof(struct smc_diag_linkinfo) by commit 79d39fc503b4 > ("net/smc: Add netlink net namespace support") introduced an ABI > regression: since struct smc_diag_lgrinfo contains an object of > type "struct smc_diag_linkinfo", offset of all subsequent members > of struct smc_diag_lgrinfo was changed by that change. > > As result, applications compiled with the old version > of struct smc_diag_linkinfo will receive garbage in > struct smc_diag_lgrinfo.role if the kernel implements > this new version of struct smc_diag_linkinfo. > > Fix this regression by reverting the part of commit 79d39fc503b4 that > changes struct smc_diag_linkinfo. After all, there is SMC_GEN_NETLINK > interface which is good enough, so there is probably no need to touch > the smc_diag ABI in the first place. Reviewed-by: Karsten Graul <kgraul@linux.ibm.com> Thank you Dmitry. ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] Partially revert "net/smc: Add netlink net namespace support" 2022-02-02 3:09 ` [PATCH] Partially revert "net/smc: Add netlink net namespace support" Dmitry V. Levin 2022-02-02 7:26 ` Karsten Graul @ 2022-02-09 9:43 ` Tony Lu 1 sibling, 0 replies; 5+ messages in thread From: Tony Lu @ 2022-02-09 9:43 UTC (permalink / raw) To: Dmitry V. Levin Cc: Karsten Graul, kuba, davem, netdev, linux-s390, linux-rdma, linux-api On Wed, Feb 02, 2022 at 06:09:04AM +0300, Dmitry V. Levin wrote: > The change of sizeof(struct smc_diag_linkinfo) by commit 79d39fc503b4 > ("net/smc: Add netlink net namespace support") introduced an ABI > regression: since struct smc_diag_lgrinfo contains an object of > type "struct smc_diag_linkinfo", offset of all subsequent members > of struct smc_diag_lgrinfo was changed by that change. > > As result, applications compiled with the old version > of struct smc_diag_linkinfo will receive garbage in > struct smc_diag_lgrinfo.role if the kernel implements > this new version of struct smc_diag_linkinfo. > > Fix this regression by reverting the part of commit 79d39fc503b4 that > changes struct smc_diag_linkinfo. After all, there is SMC_GEN_NETLINK > interface which is good enough, so there is probably no need to touch > the smc_diag ABI in the first place. > > Fixes: 79d39fc503b4 ("net/smc: Add netlink net namespace support") > Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> Thank you and Karsten. It was my negligence that caused the ABI incompatibility issue. I will consider to fix it completely. And we are starting to build smc-tools and other userspace test for potential ABI modifications. Best regards, Tony Lu ^ permalink raw reply [flat|nested] 5+ messages in thread
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2022-01-31 0:24 ` [PATCH 2/4] net/smc: Add netlink net namespace support Dmitry V. Levin
2022-01-31 13:49 ` Karsten Graul
2022-02-02 3:09 ` [PATCH] Partially revert "net/smc: Add netlink net namespace support" Dmitry V. Levin
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2022-02-09 9:43 ` Tony Lu
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