| Message ID | 1416911328-10979-10-git-send-email-jiri@resnulli.us |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
On 11/25/14 05:28, Jiri Pirko wrote: > From: Scott Feldman <sfeldma@gmail.com> > > When the swdev device learns a new mac/vlan on a port, it sends some async > notification to the driver and the driver installs an FDB in the device. > To give a holistic system view, the learned mac/vlan should be reflected > in the bridge's FBD table, so the user, using normal iproute2 cmds, can view > what is currently learned by the device. This API on the bridge driver gives > a way for the swdev driver to install an FBD entry in the bridge FBD table. > (And remove one). > > This is equivalent to the device running these cmds: > > bridge fdb [add|del] <mac> dev <dev> vid <vlan id> master > > This patch needs some extra eyeballs for review, in paricular around the > locking and contexts. > > Signed-off-by: Scott Feldman <sfeldma@gmail.com> > Signed-off-by: Jiri Pirko <jiri@resnulli.us> Like it (thanks for taking the earlier feedback) but I do not see other issue we discussed on policy attribute check that says "I need you to sync this from offload/chip to kernel" so for now only conditional Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> cheers, jamal -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Nov 25, 2014 at 11:28:40AM +0100, Jiri Pirko wrote: > From: Scott Feldman <sfeldma@gmail.com> > > When the swdev device learns a new mac/vlan on a port, it sends some async > notification to the driver and the driver installs an FDB in the device. > To give a holistic system view, the learned mac/vlan should be reflected > in the bridge's FBD table, so the user, using normal iproute2 cmds, can view > what is currently learned by the device. This API on the bridge driver gives > a way for the swdev driver to install an FBD entry in the bridge FBD table. > (And remove one). > > This is equivalent to the device running these cmds: > > bridge fdb [add|del] <mac> dev <dev> vid <vlan id> master > > This patch needs some extra eyeballs for review, in paricular around the > locking and contexts. > > Signed-off-by: Scott Feldman <sfeldma@gmail.com> > Signed-off-by: Jiri Pirko <jiri@resnulli.us> > --- > v2->v3: > -added "external" word into function names to emphasize fdbs are learned > externally > -added "added_by_external_learn" to fbd entry struct indicate the entry > was learned externaly and build some logic around that > -expose the fact that fdb entry was learned externally to userspace > v1->v2: > -no change > --- > include/linux/if_bridge.h | 18 +++++++++ > include/uapi/linux/neighbour.h | 1 + > net/bridge/br_fdb.c | 91 +++++++++++++++++++++++++++++++++++++++++- > net/bridge/br_private.h | 1 + > 4 files changed, 110 insertions(+), 1 deletion(-) > > diff --git a/include/linux/if_bridge.h b/include/linux/if_bridge.h > index 808dcb8..fa2eca6 100644 > --- a/include/linux/if_bridge.h > +++ b/include/linux/if_bridge.h > @@ -37,6 +37,24 @@ extern void brioctl_set(int (*ioctl_hook)(struct net *, unsigned int, void __use > typedef int br_should_route_hook_t(struct sk_buff *skb); > extern br_should_route_hook_t __rcu *br_should_route_hook; > > +#if IS_ENABLED(CONFIG_BRIDGE) > +int br_fdb_external_learn_add(struct net_device *dev, > + const unsigned char *addr, u16 vid); > +int br_fdb_external_learn_del(struct net_device *dev, > + const unsigned char *addr, u16 vid); > +#else > +static inline int br_fdb_external_learn_add(struct net_device *dev, > + const unsigned char *addr, u16 vid) > +{ > + return 0; > +} > +static inline int br_fdb_external_learn_del(struct net_device *dev, > + const unsigned char *addr, u16 vid) > +{ > + return 0; > +} > +#endif > + > #if IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_BRIDGE_IGMP_SNOOPING) > int br_multicast_list_adjacent(struct net_device *dev, > struct list_head *br_ip_list); > diff --git a/include/uapi/linux/neighbour.h b/include/uapi/linux/neighbour.h > index 4a1d7e9..3a9b0df 100644 > --- a/include/uapi/linux/neighbour.h > +++ b/include/uapi/linux/neighbour.h > @@ -40,6 +40,7 @@ enum { > > #define NTF_SELF 0x02 > #define NTF_MASTER 0x04 > +#define NTF_EXT_LEARNED 0x10 > > /* > * Neighbor Cache Entry States. > diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c > index b1be971..b42e71d 100644 > --- a/net/bridge/br_fdb.c > +++ b/net/bridge/br_fdb.c > @@ -481,6 +481,7 @@ static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head, > fdb->is_local = 0; > fdb->is_static = 0; > fdb->added_by_user = 0; > + fdb->added_by_external_learn = 0; > fdb->updated = fdb->used = jiffies; > hlist_add_head_rcu(&fdb->hlist, head); > } > @@ -613,7 +614,7 @@ static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br, > ndm->ndm_family = AF_BRIDGE; > ndm->ndm_pad1 = 0; > ndm->ndm_pad2 = 0; > - ndm->ndm_flags = 0; > + ndm->ndm_flags = fdb->added_by_external_learn ? NTF_EXT_LEARNED : 0; > ndm->ndm_type = 0; > ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex; > ndm->ndm_state = fdb_to_nud(fdb); > @@ -983,3 +984,91 @@ void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p) > } > } > } > + > +int br_fdb_external_learn_add(struct net_device *dev, > + const unsigned char *addr, u16 vid) > +{ > + struct net_bridge_port *p; > + struct net_bridge *br; > + struct hlist_head *head; > + struct net_bridge_fdb_entry *fdb; > + int err = 0; > + > + rtnl_lock(); > + > + p = br_port_get_rtnl(dev); > + if (!p) { > + pr_info("bridge: %s not a bridge port\n", dev->name); > + err = -EINVAL; > + goto err_rtnl_unlock; > + } > + > + br = p->br; > + > + spin_lock(&br->hash_lock); (Since you asked to check locking...) Most of the other fdb_add/delete/insert/update calls take this with spin_lock_bh. Did you try this with lockdep enabled just to see if that is needed here? I suspect that anytime br->hash_lock is taken it will need to be with softirqs disabled from this point forward. > + > + head = &br->hash[br_mac_hash(addr, vid)]; > + fdb = fdb_find(head, addr, vid); > + if (!fdb) { > + fdb = fdb_create(head, p, addr, vid); > + if (!fdb) { > + err = -ENOMEM; > + goto err_unlock; > + } > + fdb->added_by_external_learn = 1; > + fdb_notify(br, fdb, RTM_NEWNEIGH); > + } else if (fdb->added_by_external_learn) { > + /* Refresh entry */ > + fdb->updated = fdb->used = jiffies; > + } else if (!fdb->added_by_user) { > + /* Take over SW learned entry */ > + fdb->added_by_external_learn = 1; > + fdb->updated = jiffies; > + fdb_notify(br, fdb, RTM_NEWNEIGH); > + } > + > +err_unlock: > + spin_unlock(&br->hash_lock); > +err_rtnl_unlock: > + rtnl_unlock(); > + > + return err; > +} > +EXPORT_SYMBOL(br_fdb_external_learn_add); > + > +int br_fdb_external_learn_del(struct net_device *dev, > + const unsigned char *addr, u16 vid) > +{ > + struct net_bridge_port *p; > + struct net_bridge *br; > + struct hlist_head *head; > + struct net_bridge_fdb_entry *fdb; > + int err = 0; > + > + rtnl_lock(); > + > + p = br_port_get_rtnl(dev); > + if (!p) { > + pr_info("bridge: %s not a bridge port\n", dev->name); > + err = -EINVAL; > + goto err_rtnl_unlock; > + } > + > + br = p->br; > + > + spin_lock(&br->hash_lock); Same comment as above here. > + > + head = &br->hash[br_mac_hash(addr, vid)]; > + fdb = fdb_find(head, addr, vid); > + if (fdb && fdb->added_by_external_learn) > + fdb_delete(br, fdb); > + else > + err = -ENOENT; > + > + spin_unlock(&br->hash_lock); > +err_rtnl_unlock: > + rtnl_unlock(); > + > + return err; > +} > +EXPORT_SYMBOL(br_fdb_external_learn_del); > diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h > index 4f577c4..02cd63b 100644 > --- a/net/bridge/br_private.h > +++ b/net/bridge/br_private.h > @@ -101,6 +101,7 @@ struct net_bridge_fdb_entry > unsigned char is_local; > unsigned char is_static; > unsigned char added_by_user; > + unsigned char added_by_external_learn; > __u16 vlan_id; > }; > > -- > 1.9.3 > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 11/25/14 at 11:38am, Andy Gospodarek wrote: > On Tue, Nov 25, 2014 at 11:28:40AM +0100, Jiri Pirko wrote: > > From: Scott Feldman <sfeldma@gmail.com> > > > > When the swdev device learns a new mac/vlan on a port, it sends some async > > notification to the driver and the driver installs an FDB in the device. > > To give a holistic system view, the learned mac/vlan should be reflected > > in the bridge's FBD table, so the user, using normal iproute2 cmds, can view > > what is currently learned by the device. This API on the bridge driver gives > > a way for the swdev driver to install an FBD entry in the bridge FBD table. > > (And remove one). > > > > This is equivalent to the device running these cmds: > > > > bridge fdb [add|del] <mac> dev <dev> vid <vlan id> master > > > > This patch needs some extra eyeballs for review, in paricular around the > > locking and contexts. > > > > Signed-off-by: Scott Feldman <sfeldma@gmail.com> > > Signed-off-by: Jiri Pirko <jiri@resnulli.us> I like the simplicity of this. That said, given we'll have multiple users of swdev including OVS, shouldn't this be a notifier or a callback that depends on who is controlling the device? > > + spin_lock(&br->hash_lock); > (Since you asked to check locking...) > > Most of the other fdb_add/delete/insert/update calls take this with > spin_lock_bh. Did you try this with lockdep enabled just to see if that > is needed here? I suspect that anytime br->hash_lock is taken it will > need to be with softirqs disabled from this point forward. At least br_fdb_update() seems to be called from BH context so I would agree and argue the lock in br_fdb_cleanup() and br_fdb_update() need a fix too. I'll send a patch. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 25/11/14 02:28, Jiri Pirko wrote: > From: Scott Feldman <sfeldma@gmail.com> > > When the swdev device learns a new mac/vlan on a port, it sends some async > notification to the driver and the driver installs an FDB in the device. > To give a holistic system view, the learned mac/vlan should be reflected > in the bridge's FBD table, so the user, using normal iproute2 cmds, can view > what is currently learned by the device. This API on the bridge driver gives > a way for the swdev driver to install an FBD entry in the bridge FBD table. > (And remove one). > > This is equivalent to the device running these cmds: > > bridge fdb [add|del] <mac> dev <dev> vid <vlan id> master > > This patch needs some extra eyeballs for review, in paricular around the > locking and contexts. > > Signed-off-by: Scott Feldman <sfeldma@gmail.com> > Signed-off-by: Jiri Pirko <jiri@resnulli.us> > --- [snip] > diff --git a/include/uapi/linux/neighbour.h b/include/uapi/linux/neighbour.h > index 4a1d7e9..3a9b0df 100644 > --- a/include/uapi/linux/neighbour.h > +++ b/include/uapi/linux/neighbour.h > @@ -40,6 +40,7 @@ enum { > > #define NTF_SELF 0x02 > #define NTF_MASTER 0x04 > +#define NTF_EXT_LEARNED 0x10 This file could use some re-ordering to have the constants in ascending order. [snip] > + head = &br->hash[br_mac_hash(addr, vid)]; > + fdb = fdb_find(head, addr, vid); > + if (!fdb) { > + fdb = fdb_create(head, p, addr, vid); > + if (!fdb) { > + err = -ENOMEM; > + goto err_unlock; > + } > + fdb->added_by_external_learn = 1; > + fdb_notify(br, fdb, RTM_NEWNEIGH); > + } else if (fdb->added_by_external_learn) { > + /* Refresh entry */ > + fdb->updated = fdb->used = jiffies; > + } else if (!fdb->added_by_user) { > + /* Take over SW learned entry */ > + fdb->added_by_external_learn = 1; > + fdb->updated = jiffies; > + fdb_notify(br, fdb, RTM_NEWNEIGH); > + } Is there any case where this fdb entry gets re-used and is no longer added by an external learning? Should we clear this flag somewhere? [snip] > +EXPORT_SYMBOL(br_fdb_external_learn_del); > diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h > index 4f577c4..02cd63b 100644 > --- a/net/bridge/br_private.h > +++ b/net/bridge/br_private.h > @@ -101,6 +101,7 @@ struct net_bridge_fdb_entry > unsigned char is_local; > unsigned char is_static; > unsigned char added_by_user; > + unsigned char added_by_external_learn; Pheww, we could be saving some memory footprint here by using different types here ;) -- Florian -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Nov 25, 2014 at 12:36 PM, Thomas Graf <tgraf@suug.ch> wrote: > On 11/25/14 at 11:38am, Andy Gospodarek wrote: >> On Tue, Nov 25, 2014 at 11:28:40AM +0100, Jiri Pirko wrote: >> > From: Scott Feldman <sfeldma@gmail.com> >> > >> > When the swdev device learns a new mac/vlan on a port, it sends some async >> > notification to the driver and the driver installs an FDB in the device. >> > To give a holistic system view, the learned mac/vlan should be reflected >> > in the bridge's FBD table, so the user, using normal iproute2 cmds, can view >> > what is currently learned by the device. This API on the bridge driver gives >> > a way for the swdev driver to install an FBD entry in the bridge FBD table. >> > (And remove one). >> > >> > This is equivalent to the device running these cmds: >> > >> > bridge fdb [add|del] <mac> dev <dev> vid <vlan id> master >> > >> > This patch needs some extra eyeballs for review, in paricular around the >> > locking and contexts. >> > >> > Signed-off-by: Scott Feldman <sfeldma@gmail.com> >> > Signed-off-by: Jiri Pirko <jiri@resnulli.us> > > I like the simplicity of this. That said, given we'll have multiple > users of swdev including OVS, shouldn't this be a notifier or a > callback that depends on who is controlling the device? I like the idea. When the switch port joins Linux bridge or OVS datapath, a callback is registered with the driver. That way the driver doesn't really care if the port is a bridge member or an OVS vport in a datapath. It's just passing up the FDB entry (port/mac/vlan) details to the container device. Can we hold this idea until this patchset sticks? I think once OVS support comes back into the swdev model would be the time to address this. > >> > + spin_lock(&br->hash_lock); >> (Since you asked to check locking...) >> >> Most of the other fdb_add/delete/insert/update calls take this with >> spin_lock_bh. Did you try this with lockdep enabled just to see if that >> is needed here? I suspect that anytime br->hash_lock is taken it will >> need to be with softirqs disabled from this point forward. > > At least br_fdb_update() seems to be called from BH context so I would > agree and argue the lock in br_fdb_cleanup() and br_fdb_update() need a > fix too. I'll send a patch. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Nov 25, 2014 at 12:44 PM, Florian Fainelli <f.fainelli@gmail.com> wrote: > On 25/11/14 02:28, Jiri Pirko wrote: >> From: Scott Feldman <sfeldma@gmail.com> >> >> When the swdev device learns a new mac/vlan on a port, it sends some async >> notification to the driver and the driver installs an FDB in the device. >> To give a holistic system view, the learned mac/vlan should be reflected >> in the bridge's FBD table, so the user, using normal iproute2 cmds, can view >> what is currently learned by the device. This API on the bridge driver gives >> a way for the swdev driver to install an FBD entry in the bridge FBD table. >> (And remove one). >> >> This is equivalent to the device running these cmds: >> >> bridge fdb [add|del] <mac> dev <dev> vid <vlan id> master >> >> This patch needs some extra eyeballs for review, in paricular around the >> locking and contexts. >> >> Signed-off-by: Scott Feldman <sfeldma@gmail.com> >> Signed-off-by: Jiri Pirko <jiri@resnulli.us> >> --- > > [snip] > >> + head = &br->hash[br_mac_hash(addr, vid)]; >> + fdb = fdb_find(head, addr, vid); >> + if (!fdb) { >> + fdb = fdb_create(head, p, addr, vid); >> + if (!fdb) { >> + err = -ENOMEM; >> + goto err_unlock; >> + } >> + fdb->added_by_external_learn = 1; >> + fdb_notify(br, fdb, RTM_NEWNEIGH); >> + } else if (fdb->added_by_external_learn) { >> + /* Refresh entry */ >> + fdb->updated = fdb->used = jiffies; >> + } else if (!fdb->added_by_user) { >> + /* Take over SW learned entry */ >> + fdb->added_by_external_learn = 1; >> + fdb->updated = jiffies; >> + fdb_notify(br, fdb, RTM_NEWNEIGH); >> + } > > Is there any case where this fdb entry gets re-used and is no longer > added by an external learning? Should we clear this flag somewhere? Once the FDB entry is marked "added_by_external_learn" it stays marked as such until removed by aging cleanup process (or flushed due to interface down, etc). If aged out (and now deleted), the FDB entry may come back either by SW learn or by HW learn. If SW learn comes first, and then HW learn, HW learn will override and mark the existing FDB entry "added_by_external_learn". So there is take-over by HW but no give-back to SW. And there is no explicit clearing of the mark short of deleting the FDB entry. The mark is mostly for letting user's know which FDB entries where learned by HW and synced to the bridge's FDB. > [snip] > >> +EXPORT_SYMBOL(br_fdb_external_learn_del); >> diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h >> index 4f577c4..02cd63b 100644 >> --- a/net/bridge/br_private.h >> +++ b/net/bridge/br_private.h >> @@ -101,6 +101,7 @@ struct net_bridge_fdb_entry >> unsigned char is_local; >> unsigned char is_static; >> unsigned char added_by_user; >> + unsigned char added_by_external_learn; > > Pheww, we could be saving some memory footprint here by using different > types here ;) > -- > Florian -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 25/11/14 18:03, Scott Feldman wrote: > On Tue, Nov 25, 2014 at 12:44 PM, Florian Fainelli <f.fainelli@gmail.com> wrote: >> On 25/11/14 02:28, Jiri Pirko wrote: >>> From: Scott Feldman <sfeldma@gmail.com> >>> >>> When the swdev device learns a new mac/vlan on a port, it sends some async >>> notification to the driver and the driver installs an FDB in the device. >>> To give a holistic system view, the learned mac/vlan should be reflected >>> in the bridge's FBD table, so the user, using normal iproute2 cmds, can view >>> what is currently learned by the device. This API on the bridge driver gives >>> a way for the swdev driver to install an FBD entry in the bridge FBD table. >>> (And remove one). >>> >>> This is equivalent to the device running these cmds: >>> >>> bridge fdb [add|del] <mac> dev <dev> vid <vlan id> master >>> >>> This patch needs some extra eyeballs for review, in paricular around the >>> locking and contexts. >>> >>> Signed-off-by: Scott Feldman <sfeldma@gmail.com> >>> Signed-off-by: Jiri Pirko <jiri@resnulli.us> >>> --- >> >> [snip] >> >>> + head = &br->hash[br_mac_hash(addr, vid)]; >>> + fdb = fdb_find(head, addr, vid); >>> + if (!fdb) { >>> + fdb = fdb_create(head, p, addr, vid); >>> + if (!fdb) { >>> + err = -ENOMEM; >>> + goto err_unlock; >>> + } >>> + fdb->added_by_external_learn = 1; >>> + fdb_notify(br, fdb, RTM_NEWNEIGH); >>> + } else if (fdb->added_by_external_learn) { >>> + /* Refresh entry */ >>> + fdb->updated = fdb->used = jiffies; >>> + } else if (!fdb->added_by_user) { >>> + /* Take over SW learned entry */ >>> + fdb->added_by_external_learn = 1; >>> + fdb->updated = jiffies; >>> + fdb_notify(br, fdb, RTM_NEWNEIGH); >>> + } >> >> Is there any case where this fdb entry gets re-used and is no longer >> added by an external learning? Should we clear this flag somewhere? > > Once the FDB entry is marked "added_by_external_learn" it stays marked > as such until removed by aging cleanup process (or flushed due to > interface down, etc). If aged out (and now deleted), the FDB entry > may come back either by SW learn or by HW learn. If SW learn comes > first, and then HW learn, HW learn will override and mark the existing > FDB entry "added_by_external_learn". So there is take-over by HW but > no give-back to SW. And there is no explicit clearing of the mark > short of deleting the FDB entry. The mark is mostly for letting > user's know which FDB entries where learned by HW and synced to the > bridge's FDB. Thanks, makes sense now. This is probably obvious in this context, but maybe it would not hurt to come up with a documentation that describe the offload API, FDB entry lifetime and HW/SW ownership etc... > >> [snip] >> >>> +EXPORT_SYMBOL(br_fdb_external_learn_del); >>> diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h >>> index 4f577c4..02cd63b 100644 >>> --- a/net/bridge/br_private.h >>> +++ b/net/bridge/br_private.h >>> @@ -101,6 +101,7 @@ struct net_bridge_fdb_entry >>> unsigned char is_local; >>> unsigned char is_static; >>> unsigned char added_by_user; >>> + unsigned char added_by_external_learn; >> >> Pheww, we could be saving some memory footprint here by using different >> types here ;) >> -- >> Florian -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Nov 25, 2014 at 4:34 PM, Florian Fainelli <f.fainelli@gmail.com> wrote: > On 25/11/14 18:03, Scott Feldman wrote: >> On Tue, Nov 25, 2014 at 12:44 PM, Florian Fainelli <f.fainelli@gmail.com> wrote: >>> On 25/11/14 02:28, Jiri Pirko wrote: >>>> From: Scott Feldman <sfeldma@gmail.com> >>>> >>>> When the swdev device learns a new mac/vlan on a port, it sends some async >>>> notification to the driver and the driver installs an FDB in the device. >>>> To give a holistic system view, the learned mac/vlan should be reflected >>>> in the bridge's FBD table, so the user, using normal iproute2 cmds, can view >>>> what is currently learned by the device. This API on the bridge driver gives >>>> a way for the swdev driver to install an FBD entry in the bridge FBD table. >>>> (And remove one). >>>> >>>> This is equivalent to the device running these cmds: >>>> >>>> bridge fdb [add|del] <mac> dev <dev> vid <vlan id> master >>>> >>>> This patch needs some extra eyeballs for review, in paricular around the >>>> locking and contexts. >>>> >>>> Signed-off-by: Scott Feldman <sfeldma@gmail.com> >>>> Signed-off-by: Jiri Pirko <jiri@resnulli.us> >>>> --- >>> >>> [snip] >>> >>>> + head = &br->hash[br_mac_hash(addr, vid)]; >>>> + fdb = fdb_find(head, addr, vid); >>>> + if (!fdb) { >>>> + fdb = fdb_create(head, p, addr, vid); >>>> + if (!fdb) { >>>> + err = -ENOMEM; >>>> + goto err_unlock; >>>> + } >>>> + fdb->added_by_external_learn = 1; >>>> + fdb_notify(br, fdb, RTM_NEWNEIGH); >>>> + } else if (fdb->added_by_external_learn) { >>>> + /* Refresh entry */ >>>> + fdb->updated = fdb->used = jiffies; >>>> + } else if (!fdb->added_by_user) { >>>> + /* Take over SW learned entry */ >>>> + fdb->added_by_external_learn = 1; >>>> + fdb->updated = jiffies; >>>> + fdb_notify(br, fdb, RTM_NEWNEIGH); >>>> + } >>> >>> Is there any case where this fdb entry gets re-used and is no longer >>> added by an external learning? Should we clear this flag somewhere? >> >> Once the FDB entry is marked "added_by_external_learn" it stays marked >> as such until removed by aging cleanup process (or flushed due to >> interface down, etc). If aged out (and now deleted), the FDB entry >> may come back either by SW learn or by HW learn. If SW learn comes >> first, and then HW learn, HW learn will override and mark the existing >> FDB entry "added_by_external_learn". So there is take-over by HW but >> no give-back to SW. And there is no explicit clearing of the mark >> short of deleting the FDB entry. The mark is mostly for letting >> user's know which FDB entries where learned by HW and synced to the >> bridge's FDB. > > Thanks, makes sense now. This is probably obvious in this context, but > maybe it would not hurt to come up with a documentation that describe > the offload API, FDB entry lifetime and HW/SW ownership etc... I have an updated Documentation/networking/switchdev.txt that covers the swdev APIs and usage and notes, but Jiri is being stingy with it. Will get this out, either in v4 or follow-on patches. There is enough going on just with L2 offload that we're going to need some good documentation to guide implementers. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 11/25/14 17:44, Florian Fainelli wrote: > On 25/11/14 02:28, Jiri Pirko wrote: >> @@ -101,6 +101,7 @@ struct net_bridge_fdb_entry >> unsigned char is_local; >> unsigned char is_static; >> unsigned char added_by_user; >> + unsigned char added_by_external_learn; > > Pheww, we could be saving some memory footprint here by using different > types here ;) I tried to bring up this issue earlier. Unfortuately about 15 different things being transfered over bridge netlink use 8 bits for representing a bit of information. A bitmap selector would be a lot more efficient. Not unusual to have a few hundred thousand entries. cheers, jamal > -- > Florian > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Wed, Nov 26, 2014 at 03:40:59AM CET, sfeldma@gmail.com wrote: >On Tue, Nov 25, 2014 at 4:34 PM, Florian Fainelli <f.fainelli@gmail.com> wrote: >> On 25/11/14 18:03, Scott Feldman wrote: >>> On Tue, Nov 25, 2014 at 12:44 PM, Florian Fainelli <f.fainelli@gmail.com> wrote: >>>> On 25/11/14 02:28, Jiri Pirko wrote: >>>>> From: Scott Feldman <sfeldma@gmail.com> >>>>> >>>>> When the swdev device learns a new mac/vlan on a port, it sends some async >>>>> notification to the driver and the driver installs an FDB in the device. >>>>> To give a holistic system view, the learned mac/vlan should be reflected >>>>> in the bridge's FBD table, so the user, using normal iproute2 cmds, can view >>>>> what is currently learned by the device. This API on the bridge driver gives >>>>> a way for the swdev driver to install an FBD entry in the bridge FBD table. >>>>> (And remove one). >>>>> >>>>> This is equivalent to the device running these cmds: >>>>> >>>>> bridge fdb [add|del] <mac> dev <dev> vid <vlan id> master >>>>> >>>>> This patch needs some extra eyeballs for review, in paricular around the >>>>> locking and contexts. >>>>> >>>>> Signed-off-by: Scott Feldman <sfeldma@gmail.com> >>>>> Signed-off-by: Jiri Pirko <jiri@resnulli.us> >>>>> --- >>>> >>>> [snip] >>>> >>>>> + head = &br->hash[br_mac_hash(addr, vid)]; >>>>> + fdb = fdb_find(head, addr, vid); >>>>> + if (!fdb) { >>>>> + fdb = fdb_create(head, p, addr, vid); >>>>> + if (!fdb) { >>>>> + err = -ENOMEM; >>>>> + goto err_unlock; >>>>> + } >>>>> + fdb->added_by_external_learn = 1; >>>>> + fdb_notify(br, fdb, RTM_NEWNEIGH); >>>>> + } else if (fdb->added_by_external_learn) { >>>>> + /* Refresh entry */ >>>>> + fdb->updated = fdb->used = jiffies; >>>>> + } else if (!fdb->added_by_user) { >>>>> + /* Take over SW learned entry */ >>>>> + fdb->added_by_external_learn = 1; >>>>> + fdb->updated = jiffies; >>>>> + fdb_notify(br, fdb, RTM_NEWNEIGH); >>>>> + } >>>> >>>> Is there any case where this fdb entry gets re-used and is no longer >>>> added by an external learning? Should we clear this flag somewhere? >>> >>> Once the FDB entry is marked "added_by_external_learn" it stays marked >>> as such until removed by aging cleanup process (or flushed due to >>> interface down, etc). If aged out (and now deleted), the FDB entry >>> may come back either by SW learn or by HW learn. If SW learn comes >>> first, and then HW learn, HW learn will override and mark the existing >>> FDB entry "added_by_external_learn". So there is take-over by HW but >>> no give-back to SW. And there is no explicit clearing of the mark >>> short of deleting the FDB entry. The mark is mostly for letting >>> user's know which FDB entries where learned by HW and synced to the >>> bridge's FDB. >> >> Thanks, makes sense now. This is probably obvious in this context, but >> maybe it would not hurt to come up with a documentation that describe >> the offload API, FDB entry lifetime and HW/SW ownership etc... > >I have an updated Documentation/networking/switchdev.txt that covers >the swdev APIs and usage and notes, but Jiri is being stingy with it. The doc update you mention includes also fib offload which we are not pushing now. I have that patches in queue. >Will get this out, either in v4 or follow-on patches. There is enough >going on just with L2 offload that we're going to need some good >documentation to guide implementers. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Wed, Nov 26, 2014 at 02:48:04AM CET, sfeldma@gmail.com wrote: >On Tue, Nov 25, 2014 at 12:36 PM, Thomas Graf <tgraf@suug.ch> wrote: >> On 11/25/14 at 11:38am, Andy Gospodarek wrote: >>> On Tue, Nov 25, 2014 at 11:28:40AM +0100, Jiri Pirko wrote: >>> > From: Scott Feldman <sfeldma@gmail.com> >>> > >>> > When the swdev device learns a new mac/vlan on a port, it sends some async >>> > notification to the driver and the driver installs an FDB in the device. >>> > To give a holistic system view, the learned mac/vlan should be reflected >>> > in the bridge's FBD table, so the user, using normal iproute2 cmds, can view >>> > what is currently learned by the device. This API on the bridge driver gives >>> > a way for the swdev driver to install an FBD entry in the bridge FBD table. >>> > (And remove one). >>> > >>> > This is equivalent to the device running these cmds: >>> > >>> > bridge fdb [add|del] <mac> dev <dev> vid <vlan id> master >>> > >>> > This patch needs some extra eyeballs for review, in paricular around the >>> > locking and contexts. >>> > >>> > Signed-off-by: Scott Feldman <sfeldma@gmail.com> >>> > Signed-off-by: Jiri Pirko <jiri@resnulli.us> >> >> I like the simplicity of this. That said, given we'll have multiple >> users of swdev including OVS, shouldn't this be a notifier or a >> callback that depends on who is controlling the device? > >I like the idea. When the switch port joins Linux bridge or OVS >datapath, a callback is registered with the driver. That way the >driver doesn't really care if the port is a bridge member or an OVS >vport in a datapath. It's just passing up the FDB entry >(port/mac/vlan) details to the container device. Can we hold this >idea until this patchset sticks? I think once OVS support comes back >into the swdev model would be the time to address this. Yep, I agree this is a good idea and I also vote for implemeting this as a follow-up. Thanks. > >> >>> > + spin_lock(&br->hash_lock); >>> (Since you asked to check locking...) >>> >>> Most of the other fdb_add/delete/insert/update calls take this with >>> spin_lock_bh. Did you try this with lockdep enabled just to see if that >>> is needed here? I suspect that anytime br->hash_lock is taken it will >>> need to be with softirqs disabled from this point forward. >> >> At least br_fdb_update() seems to be called from BH context so I would >> agree and argue the lock in br_fdb_cleanup() and br_fdb_update() need a >> fix too. I'll send a patch. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/linux/if_bridge.h b/include/linux/if_bridge.h index 808dcb8..fa2eca6 100644 --- a/include/linux/if_bridge.h +++ b/include/linux/if_bridge.h @@ -37,6 +37,24 @@ extern void brioctl_set(int (*ioctl_hook)(struct net *, unsigned int, void __use typedef int br_should_route_hook_t(struct sk_buff *skb); extern br_should_route_hook_t __rcu *br_should_route_hook; +#if IS_ENABLED(CONFIG_BRIDGE) +int br_fdb_external_learn_add(struct net_device *dev, + const unsigned char *addr, u16 vid); +int br_fdb_external_learn_del(struct net_device *dev, + const unsigned char *addr, u16 vid); +#else +static inline int br_fdb_external_learn_add(struct net_device *dev, + const unsigned char *addr, u16 vid) +{ + return 0; +} +static inline int br_fdb_external_learn_del(struct net_device *dev, + const unsigned char *addr, u16 vid) +{ + return 0; +} +#endif + #if IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_BRIDGE_IGMP_SNOOPING) int br_multicast_list_adjacent(struct net_device *dev, struct list_head *br_ip_list); diff --git a/include/uapi/linux/neighbour.h b/include/uapi/linux/neighbour.h index 4a1d7e9..3a9b0df 100644 --- a/include/uapi/linux/neighbour.h +++ b/include/uapi/linux/neighbour.h @@ -40,6 +40,7 @@ enum { #define NTF_SELF 0x02 #define NTF_MASTER 0x04 +#define NTF_EXT_LEARNED 0x10 /* * Neighbor Cache Entry States. diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c index b1be971..b42e71d 100644 --- a/net/bridge/br_fdb.c +++ b/net/bridge/br_fdb.c @@ -481,6 +481,7 @@ static struct net_bridge_fdb_entry *fdb_create(struct hlist_head *head, fdb->is_local = 0; fdb->is_static = 0; fdb->added_by_user = 0; + fdb->added_by_external_learn = 0; fdb->updated = fdb->used = jiffies; hlist_add_head_rcu(&fdb->hlist, head); } @@ -613,7 +614,7 @@ static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br, ndm->ndm_family = AF_BRIDGE; ndm->ndm_pad1 = 0; ndm->ndm_pad2 = 0; - ndm->ndm_flags = 0; + ndm->ndm_flags = fdb->added_by_external_learn ? NTF_EXT_LEARNED : 0; ndm->ndm_type = 0; ndm->ndm_ifindex = fdb->dst ? fdb->dst->dev->ifindex : br->dev->ifindex; ndm->ndm_state = fdb_to_nud(fdb); @@ -983,3 +984,91 @@ void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p) } } } + +int br_fdb_external_learn_add(struct net_device *dev, + const unsigned char *addr, u16 vid) +{ + struct net_bridge_port *p; + struct net_bridge *br; + struct hlist_head *head; + struct net_bridge_fdb_entry *fdb; + int err = 0; + + rtnl_lock(); + + p = br_port_get_rtnl(dev); + if (!p) { + pr_info("bridge: %s not a bridge port\n", dev->name); + err = -EINVAL; + goto err_rtnl_unlock; + } + + br = p->br; + + spin_lock(&br->hash_lock); + + head = &br->hash[br_mac_hash(addr, vid)]; + fdb = fdb_find(head, addr, vid); + if (!fdb) { + fdb = fdb_create(head, p, addr, vid); + if (!fdb) { + err = -ENOMEM; + goto err_unlock; + } + fdb->added_by_external_learn = 1; + fdb_notify(br, fdb, RTM_NEWNEIGH); + } else if (fdb->added_by_external_learn) { + /* Refresh entry */ + fdb->updated = fdb->used = jiffies; + } else if (!fdb->added_by_user) { + /* Take over SW learned entry */ + fdb->added_by_external_learn = 1; + fdb->updated = jiffies; + fdb_notify(br, fdb, RTM_NEWNEIGH); + } + +err_unlock: + spin_unlock(&br->hash_lock); +err_rtnl_unlock: + rtnl_unlock(); + + return err; +} +EXPORT_SYMBOL(br_fdb_external_learn_add); + +int br_fdb_external_learn_del(struct net_device *dev, + const unsigned char *addr, u16 vid) +{ + struct net_bridge_port *p; + struct net_bridge *br; + struct hlist_head *head; + struct net_bridge_fdb_entry *fdb; + int err = 0; + + rtnl_lock(); + + p = br_port_get_rtnl(dev); + if (!p) { + pr_info("bridge: %s not a bridge port\n", dev->name); + err = -EINVAL; + goto err_rtnl_unlock; + } + + br = p->br; + + spin_lock(&br->hash_lock); + + head = &br->hash[br_mac_hash(addr, vid)]; + fdb = fdb_find(head, addr, vid); + if (fdb && fdb->added_by_external_learn) + fdb_delete(br, fdb); + else + err = -ENOENT; + + spin_unlock(&br->hash_lock); +err_rtnl_unlock: + rtnl_unlock(); + + return err; +} +EXPORT_SYMBOL(br_fdb_external_learn_del); diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index 4f577c4..02cd63b 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -101,6 +101,7 @@ struct net_bridge_fdb_entry unsigned char is_local; unsigned char is_static; unsigned char added_by_user; + unsigned char added_by_external_learn; __u16 vlan_id; };