diff options
Diffstat (limited to 'net/atm/br2684.c')
| -rw-r--r-- | net/atm/br2684.c | 91 |
1 files changed, 71 insertions, 20 deletions
diff --git a/net/atm/br2684.c b/net/atm/br2684.c index 4819d31533e0..403e71fa88fe 100644 --- a/net/atm/br2684.c +++ b/net/atm/br2684.c @@ -68,12 +68,15 @@ struct br2684_vcc { /* keep old push, pop functions for chaining */ void (*old_push)(struct atm_vcc *vcc, struct sk_buff *skb); void (*old_pop)(struct atm_vcc *vcc, struct sk_buff *skb); + void (*old_release_cb)(struct atm_vcc *vcc); + struct module *old_owner; enum br2684_encaps encaps; struct list_head brvccs; #ifdef CONFIG_ATM_BR2684_IPFILTER struct br2684_filter filter; #endif /* CONFIG_ATM_BR2684_IPFILTER */ unsigned int copies_needed, copies_failed; + atomic_t qspace; }; struct br2684_dev { @@ -181,18 +184,15 @@ static struct notifier_block atm_dev_notifier = { static void br2684_pop(struct atm_vcc *vcc, struct sk_buff *skb) { struct br2684_vcc *brvcc = BR2684_VCC(vcc); - struct net_device *net_dev = skb->dev; - pr_debug("(vcc %p ; net_dev %p )\n", vcc, net_dev); + pr_debug("(vcc %p ; net_dev %p )\n", vcc, brvcc->device); brvcc->old_pop(vcc, skb); - if (!net_dev) - return; - - if (atm_may_send(vcc, 0)) - netif_wake_queue(net_dev); - + /* If the queue space just went up from zero, wake */ + if (atomic_inc_return(&brvcc->qspace) == 1) + netif_wake_queue(brvcc->device); } + /* * Send a packet out a particular vcc. Not to useful right now, but paves * the way for multiple vcc's per itf. Returns true if we can send, @@ -256,16 +256,30 @@ static int br2684_xmit_vcc(struct sk_buff *skb, struct net_device *dev, ATM_SKB(skb)->atm_options = atmvcc->atm_options; dev->stats.tx_packets++; dev->stats.tx_bytes += skb->len; - atmvcc->send(atmvcc, skb); - if (!atm_may_send(atmvcc, 0)) { + if (atomic_dec_return(&brvcc->qspace) < 1) { + /* No more please! */ netif_stop_queue(brvcc->device); - /*check for race with br2684_pop*/ - if (atm_may_send(atmvcc, 0)) - netif_start_queue(brvcc->device); + /* We might have raced with br2684_pop() */ + if (unlikely(atomic_read(&brvcc->qspace) > 0)) + netif_wake_queue(brvcc->device); } - return 1; + /* If this fails immediately, the skb will be freed and br2684_pop() + will wake the queue if appropriate. Just return an error so that + the stats are updated correctly */ + return !atmvcc->send(atmvcc, skb); +} + +static void br2684_release_cb(struct atm_vcc *atmvcc) +{ + struct br2684_vcc *brvcc = BR2684_VCC(atmvcc); + + if (atomic_read(&brvcc->qspace) > 0) + netif_wake_queue(brvcc->device); + + if (brvcc->old_release_cb) + brvcc->old_release_cb(atmvcc); } static inline struct br2684_vcc *pick_outgoing_vcc(const struct sk_buff *skb, @@ -279,6 +293,8 @@ static netdev_tx_t br2684_start_xmit(struct sk_buff *skb, { struct br2684_dev *brdev = BRPRIV(dev); struct br2684_vcc *brvcc; + struct atm_vcc *atmvcc; + netdev_tx_t ret = NETDEV_TX_OK; pr_debug("skb_dst(skb)=%p\n", skb_dst(skb)); read_lock(&devs_lock); @@ -289,9 +305,26 @@ static netdev_tx_t br2684_start_xmit(struct sk_buff *skb, dev->stats.tx_carrier_errors++; /* netif_stop_queue(dev); */ dev_kfree_skb(skb); - read_unlock(&devs_lock); - return NETDEV_TX_OK; + goto out_devs; } + atmvcc = brvcc->atmvcc; + + bh_lock_sock(sk_atm(atmvcc)); + + if (test_bit(ATM_VF_RELEASED, &atmvcc->flags) || + test_bit(ATM_VF_CLOSE, &atmvcc->flags) || + !test_bit(ATM_VF_READY, &atmvcc->flags)) { + dev->stats.tx_dropped++; + dev_kfree_skb(skb); + goto out; + } + + if (sock_owned_by_user(sk_atm(atmvcc))) { + netif_stop_queue(brvcc->device); + ret = NETDEV_TX_BUSY; + goto out; + } + if (!br2684_xmit_vcc(skb, dev, brvcc)) { /* * We should probably use netif_*_queue() here, but that @@ -303,8 +336,11 @@ static netdev_tx_t br2684_start_xmit(struct sk_buff *skb, dev->stats.tx_errors++; dev->stats.tx_fifo_errors++; } + out: + bh_unlock_sock(sk_atm(atmvcc)); + out_devs: read_unlock(&devs_lock); - return NETDEV_TX_OK; + return ret; } /* @@ -377,9 +413,10 @@ static void br2684_close_vcc(struct br2684_vcc *brvcc) list_del(&brvcc->brvccs); write_unlock_irq(&devs_lock); brvcc->atmvcc->user_back = NULL; /* what about vcc->recvq ??? */ + brvcc->atmvcc->release_cb = brvcc->old_release_cb; brvcc->old_push(brvcc->atmvcc, NULL); /* pass on the bad news */ + module_put(brvcc->old_owner); kfree(brvcc); - module_put(THIS_MODULE); } /* when AAL5 PDU comes in: */ @@ -504,6 +541,13 @@ static int br2684_regvcc(struct atm_vcc *atmvcc, void __user * arg) brvcc = kzalloc(sizeof(struct br2684_vcc), GFP_KERNEL); if (!brvcc) return -ENOMEM; + /* + * Allow two packets in the ATM queue. One actually being sent, and one + * for the ATM 'TX done' handler to send. It shouldn't take long to get + * the next one from the netdev queue, when we need it. More than that + * would be bufferbloat. + */ + atomic_set(&brvcc->qspace, 2); write_lock_irq(&devs_lock); net_dev = br2684_find_dev(&be.ifspec); if (net_dev == NULL) { @@ -546,9 +590,13 @@ static int br2684_regvcc(struct atm_vcc *atmvcc, void __user * arg) brvcc->encaps = (enum br2684_encaps)be.encaps; brvcc->old_push = atmvcc->push; brvcc->old_pop = atmvcc->pop; + brvcc->old_release_cb = atmvcc->release_cb; + brvcc->old_owner = atmvcc->owner; barrier(); atmvcc->push = br2684_push; atmvcc->pop = br2684_pop; + atmvcc->release_cb = br2684_release_cb; + atmvcc->owner = THIS_MODULE; /* initialize netdev carrier state */ if (atmvcc->dev->signal == ATM_PHY_SIG_LOST) @@ -687,10 +735,13 @@ static int br2684_ioctl(struct socket *sock, unsigned int cmd, return -ENOIOCTLCMD; if (!capable(CAP_NET_ADMIN)) return -EPERM; - if (cmd == ATM_SETBACKEND) + if (cmd == ATM_SETBACKEND) { + if (sock->state != SS_CONNECTED) + return -EINVAL; return br2684_regvcc(atmvcc, argp); - else + } else { return br2684_create(argp); + } #ifdef CONFIG_ATM_BR2684_IPFILTER case BR2684_SETFILT: if (atmvcc->push != br2684_push) |