| Message ID | 20220512143314.235604-12-miquel.raynal@bootlin.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | ieee802154: Synchronous Tx support | expand |
Hi, On Thu, May 12, 2022 at 10:34 AM Miquel Raynal <miquel.raynal@bootlin.com> wrote: > > In order to be able to detect possible conflicts between the net > interface core and the ieee802154 core, let's add a warning in the slow > path: we want to be sure that whenever we start an asynchronous MLME > transmission (which can be fully asynchronous) the net core somehow > agrees that this transmission is possible, ie. the device was not > stopped. Warning in this case would allow us to track down more easily > possible issues with the MLME logic if we ever get reports. > > Unlike in the hot path, such a situation cannot be handled. > > Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> > --- > net/mac802154/tx.c | 25 +++++++++++++++++++++++++ > 1 file changed, 25 insertions(+) > > diff --git a/net/mac802154/tx.c b/net/mac802154/tx.c > index a3c9f194c025..d61b076239c3 100644 > --- a/net/mac802154/tx.c > +++ b/net/mac802154/tx.c > @@ -132,6 +132,25 @@ int ieee802154_sync_and_hold_queue(struct ieee802154_local *local) > return ret; > } > > +static bool ieee802154_netif_is_down(struct ieee802154_local *local) > +{ > + struct ieee802154_sub_if_data *sdata; > + bool is_down = false; > + > + rcu_read_lock(); > + list_for_each_entry_rcu(sdata, &local->interfaces, list) { > + if (!sdata->dev) > + continue; > + > + is_down = !(sdata->dev->flags & IFF_UP); Is there not a helper for this flag? - Alex
Hi Alexander, aahringo@redhat.com wrote on Sun, 15 May 2022 18:30:28 -0400: > Hi, > > On Thu, May 12, 2022 at 10:34 AM Miquel Raynal > <miquel.raynal@bootlin.com> wrote: > > > > In order to be able to detect possible conflicts between the net > > interface core and the ieee802154 core, let's add a warning in the slow > > path: we want to be sure that whenever we start an asynchronous MLME > > transmission (which can be fully asynchronous) the net core somehow > > agrees that this transmission is possible, ie. the device was not > > stopped. Warning in this case would allow us to track down more easily > > possible issues with the MLME logic if we ever get reports. > > > > Unlike in the hot path, such a situation cannot be handled. > > > > Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> > > --- > > net/mac802154/tx.c | 25 +++++++++++++++++++++++++ > > 1 file changed, 25 insertions(+) > > > > diff --git a/net/mac802154/tx.c b/net/mac802154/tx.c > > index a3c9f194c025..d61b076239c3 100644 > > --- a/net/mac802154/tx.c > > +++ b/net/mac802154/tx.c > > @@ -132,6 +132,25 @@ int ieee802154_sync_and_hold_queue(struct ieee802154_local *local) > > return ret; > > } > > > > +static bool ieee802154_netif_is_down(struct ieee802154_local *local) > > +{ > > + struct ieee802154_sub_if_data *sdata; > > + bool is_down = false; > > + > > + rcu_read_lock(); > > + list_for_each_entry_rcu(sdata, &local->interfaces, list) { > > + if (!sdata->dev) > > + continue; > > + > > + is_down = !(sdata->dev->flags & IFF_UP); > > Is there not a helper for this flag? I was surprised that nobody cared enough about that information to create a helper. Then I grepped and figured out I was not the first to to do that... $ git grep "flags & IFF_UP" | wc -l 289
diff --git a/net/mac802154/tx.c b/net/mac802154/tx.c index a3c9f194c025..d61b076239c3 100644 --- a/net/mac802154/tx.c +++ b/net/mac802154/tx.c @@ -132,6 +132,25 @@ int ieee802154_sync_and_hold_queue(struct ieee802154_local *local) return ret; } +static bool ieee802154_netif_is_down(struct ieee802154_local *local) +{ + struct ieee802154_sub_if_data *sdata; + bool is_down = false; + + rcu_read_lock(); + list_for_each_entry_rcu(sdata, &local->interfaces, list) { + if (!sdata->dev) + continue; + + is_down = !(sdata->dev->flags & IFF_UP); + if (is_down) + break; + } + rcu_read_unlock(); + + return is_down; +} + int ieee802154_mlme_tx(struct ieee802154_local *local, struct sk_buff *skb) { int ret; @@ -145,6 +164,12 @@ int ieee802154_mlme_tx(struct ieee802154_local *local, struct sk_buff *skb) if (!local->open_count) return -EBUSY; + /* Warn if the ieee802154 core thinks MLME frames can be sent while the + * net interface expects this cannot happen. + */ + if (WARN_ON_ONCE(ieee802154_netif_is_down(local))) + return -EHOSTDOWN; + ieee802154_sync_and_hold_queue(local); ieee802154_tx(local, skb);
In order to be able to detect possible conflicts between the net interface core and the ieee802154 core, let's add a warning in the slow path: we want to be sure that whenever we start an asynchronous MLME transmission (which can be fully asynchronous) the net core somehow agrees that this transmission is possible, ie. the device was not stopped. Warning in this case would allow us to track down more easily possible issues with the MLME logic if we ever get reports. Unlike in the hot path, such a situation cannot be handled. Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> --- net/mac802154/tx.c | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+)