diff options
author | Stephen Hemminger <shemminger@osdl.org> | 2004-08-09 02:35:43 -0700 |
---|---|---|
committer | Stephen Hemminger <shemminger@osdl.org> | 2004-08-09 02:35:43 -0700 |
commit | 010a2c6560603b1297d22680a5dab9fb2413fb9e (patch) | |
tree | 69c6a0462da1a3046e318d94c1f5dd90a9e00ae5 /net | |
parent | 2c06f076af1afb7ee41957cf7a26ef8649a2c2cc (diff) | |
download | history-010a2c6560603b1297d22680a5dab9fb2413fb9e.tar.gz |
[VLAN]: Use RCU for group operations.
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@redhat.com>
Diffstat (limited to 'net')
-rw-r--r-- | net/8021q/vlan.c | 89 | ||||
-rw-r--r-- | net/8021q/vlan.h | 9 | ||||
-rw-r--r-- | net/8021q/vlan_dev.c | 14 |
3 files changed, 36 insertions, 76 deletions
diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c index dc89b4563c5cb2..ba7c638668fcde 100644 --- a/net/8021q/vlan.c +++ b/net/8021q/vlan.c @@ -38,8 +38,7 @@ /* Global VLAN variables */ /* Our listing of VLAN group(s) */ -struct vlan_group *vlan_group_hash[VLAN_GRP_HASH_SIZE]; -spinlock_t vlan_group_lock = SPIN_LOCK_UNLOCKED; +struct hlist_head vlan_group_hash[VLAN_GRP_HASH_SIZE]; #define vlan_grp_hashfn(IDX) ((((IDX) >> VLAN_GRP_HASH_SHIFT) ^ (IDX)) & VLAN_GRP_HASH_MASK) static char vlan_fullname[] = "802.1Q VLAN Support"; @@ -150,8 +149,7 @@ static void __exit vlan_cleanup_module(void) * references left. */ for (i = 0; i < VLAN_GRP_HASH_SIZE; i++) { - if (vlan_group_hash[i] != NULL) - BUG(); + BUG_ON(!hlist_empty(&vlan_group_hash[i])); } vlan_proc_cleanup(); @@ -161,48 +159,24 @@ static void __exit vlan_cleanup_module(void) module_init(vlan_proto_init); module_exit(vlan_cleanup_module); -/* Must be invoked with vlan_group_lock held. */ +/* Must be invoked with RCU read lock (no preempt) */ static struct vlan_group *__vlan_find_group(int real_dev_ifindex) { struct vlan_group *grp; + struct hlist_node *n; + int hash = vlan_grp_hashfn(real_dev_ifindex); - for (grp = vlan_group_hash[vlan_grp_hashfn(real_dev_ifindex)]; - grp != NULL; - grp = grp->next) { + hlist_for_each_entry_rcu(grp, n, &vlan_group_hash[hash], hlist) { if (grp->real_dev_ifindex == real_dev_ifindex) - break; + return grp; } - return grp; -} - -/* Must hold vlan_group_lock. */ -static void __grp_hash(struct vlan_group *grp) -{ - struct vlan_group **head; - - head = &vlan_group_hash[vlan_grp_hashfn(grp->real_dev_ifindex)]; - grp->next = *head; - *head = grp; -} - -/* Must hold vlan_group_lock. */ -static void __grp_unhash(struct vlan_group *grp) -{ - struct vlan_group *next, **pprev; - - pprev = &vlan_group_hash[vlan_grp_hashfn(grp->real_dev_ifindex)]; - next = *pprev; - while (next != grp) { - pprev = &next->next; - next = *pprev; - } - *pprev = grp->next; + return NULL; } /* Find the protocol handler. Assumes VID < VLAN_VID_MASK. * - * Must be invoked with vlan_group_lock held. + * Must be invoked with RCU read lock (no preempt) */ struct net_device *__find_vlan_dev(struct net_device *real_dev, unsigned short VID) @@ -215,6 +189,12 @@ struct net_device *__find_vlan_dev(struct net_device *real_dev, return NULL; } +static void vlan_rcu_free(struct rcu_head *rcu) +{ + kfree(container_of(rcu, struct vlan_group, rcu)); +} + + /* This returns 0 if everything went fine. * It will return 1 if the group was killed as a result. * A negative return indicates failure. @@ -237,9 +217,8 @@ static int unregister_vlan_dev(struct net_device *real_dev, if (vlan_id >= VLAN_VID_MASK) return -EINVAL; - spin_lock_bh(&vlan_group_lock); + ASSERT_RTNL(); grp = __vlan_find_group(real_dev_ifindex); - spin_unlock_bh(&vlan_group_lock); ret = 0; @@ -279,16 +258,12 @@ static int unregister_vlan_dev(struct net_device *real_dev, if (real_dev->features & NETIF_F_HW_VLAN_RX) real_dev->vlan_rx_register(real_dev, NULL); - spin_lock_bh(&vlan_group_lock); - __grp_unhash(grp); - spin_unlock_bh(&vlan_group_lock); + hlist_del_rcu(&grp->hlist); - /* Free the group, after we have removed it - * from the hash. - */ - kfree(grp); - grp = NULL; + /* Free the group, after all cpu's are done. */ + call_rcu(&grp->rcu, vlan_rcu_free); + grp = NULL; ret = 1; } } @@ -375,7 +350,6 @@ static struct net_device *register_vlan_device(const char *eth_IF_name, struct vlan_group *grp; struct net_device *new_dev; struct net_device *real_dev; /* the ethernet device */ - int r; char name[IFNAMSIZ]; #ifdef VLAN_DEBUG @@ -424,11 +398,7 @@ static struct net_device *register_vlan_device(const char *eth_IF_name, if (!(real_dev->flags & IFF_UP)) goto out_unlock; - spin_lock_bh(&vlan_group_lock); - r = (__find_vlan_dev(real_dev, VLAN_ID) != NULL); - spin_unlock_bh(&vlan_group_lock); - - if (r) { + if (__find_vlan_dev(real_dev, VLAN_ID) != NULL) { /* was already registered. */ printk(VLAN_DBG "%s: ALREADY had VLAN registered\n", __FUNCTION__); goto out_unlock; @@ -527,9 +497,7 @@ static struct net_device *register_vlan_device(const char *eth_IF_name, /* So, got the sucker initialized, now lets place * it into our local structure. */ - spin_lock_bh(&vlan_group_lock); grp = __vlan_find_group(real_dev->ifindex); - spin_unlock_bh(&vlan_group_lock); /* Note, we are running under the RTNL semaphore * so it cannot "appear" on us. @@ -543,9 +511,8 @@ static struct net_device *register_vlan_device(const char *eth_IF_name, memset(grp, 0, sizeof(struct vlan_group)); grp->real_dev_ifindex = real_dev->ifindex; - spin_lock_bh(&vlan_group_lock); - __grp_hash(grp); - spin_unlock_bh(&vlan_group_lock); + hlist_add_head_rcu(&grp->hlist, + &vlan_group_hash[vlan_grp_hashfn(real_dev->ifindex)]); if (real_dev->features & NETIF_F_HW_VLAN_RX) real_dev->vlan_rx_register(real_dev, grp); @@ -587,14 +554,10 @@ out_ret_null: static int vlan_device_event(struct notifier_block *unused, unsigned long event, void *ptr) { - struct net_device *dev = (struct net_device *)(ptr); - struct vlan_group *grp = NULL; + struct net_device *dev = ptr; + struct vlan_group *grp = __vlan_find_group(dev->ifindex); int i, flgs; - struct net_device *vlandev = NULL; - - spin_lock_bh(&vlan_group_lock); - grp = __vlan_find_group(dev->ifindex); - spin_unlock_bh(&vlan_group_lock); + struct net_device *vlandev; if (!grp) goto out; diff --git a/net/8021q/vlan.h b/net/8021q/vlan.h index 5d9b7a1d2a8b1c..830282e6fc486a 100644 --- a/net/8021q/vlan.h +++ b/net/8021q/vlan.h @@ -33,8 +33,7 @@ extern unsigned short vlan_name_type; #define VLAN_GRP_HASH_SHIFT 5 #define VLAN_GRP_HASH_SIZE (1 << VLAN_GRP_HASH_SHIFT) #define VLAN_GRP_HASH_MASK (VLAN_GRP_HASH_SIZE - 1) -extern struct vlan_group *vlan_group_hash[VLAN_GRP_HASH_SIZE]; -extern spinlock_t vlan_group_lock; +extern struct hlist_head vlan_group_hash[VLAN_GRP_HASH_SIZE]; /* Find a VLAN device by the MAC address of its Ethernet device, and * it's VLAN ID. The default configuration is to have VLAN's scope @@ -44,10 +43,8 @@ extern spinlock_t vlan_group_lock; * NOT follow the spec for VLANs, but may be useful for doing very * large quantities of VLAN MUX/DEMUX onto FrameRelay or ATM PVCs. * - * Must be invoked with vlan_group_lock held and that lock MUST NOT - * be dropped until a reference is obtained on the returned device. - * You may drop the lock earlier if you are running under the RTNL - * semaphore, however. + * Must be invoked with rcu_read_lock (ie preempt disabled) + * or with RTNL. */ struct net_device *__find_vlan_dev(struct net_device* real_dev, unsigned short VID); /* vlan.c */ diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c index 9dfce1bc7d0a12..460aabc09d2967 100644 --- a/net/8021q/vlan_dev.c +++ b/net/8021q/vlan_dev.c @@ -138,15 +138,15 @@ int vlan_skb_recv(struct sk_buff *skb, struct net_device *dev, /* We have 12 bits of vlan ID. * - * We must not drop the vlan_group_lock until we hold a + * We must not drop allow preempt until we hold a * reference to the device (netif_rx does that) or we * fail. */ - spin_lock_bh(&vlan_group_lock); + rcu_read_lock(); skb->dev = __find_vlan_dev(dev, vid); if (!skb->dev) { - spin_unlock_bh(&vlan_group_lock); + rcu_read_unlock(); #ifdef VLAN_DEBUG printk(VLAN_DBG "%s: ERROR: No net_device for VID: %i on dev: %s [%i]\n", @@ -170,7 +170,7 @@ int vlan_skb_recv(struct sk_buff *skb, struct net_device *dev, */ if (dev != VLAN_DEV_INFO(skb->dev)->real_dev) { - spin_unlock_bh(&vlan_group_lock); + rcu_read_unlock(); #ifdef VLAN_DEBUG printk(VLAN_DBG "%s: dropping skb: %p because came in on wrong device, dev: %s real_dev: %s, skb_dev: %s\n", @@ -244,7 +244,7 @@ int vlan_skb_recv(struct sk_buff *skb, struct net_device *dev, /* TODO: Add a more specific counter here. */ stats->rx_errors++; } - spin_unlock_bh(&vlan_group_lock); + rcu_read_lock(); return 0; } @@ -273,7 +273,7 @@ int vlan_skb_recv(struct sk_buff *skb, struct net_device *dev, /* TODO: Add a more specific counter here. */ stats->rx_errors++; } - spin_unlock_bh(&vlan_group_lock); + rcu_read_unlock(); return 0; } @@ -296,7 +296,7 @@ int vlan_skb_recv(struct sk_buff *skb, struct net_device *dev, /* TODO: Add a more specific counter here. */ stats->rx_errors++; } - spin_unlock_bh(&vlan_group_lock); + rcu_read_unlock(); return 0; } |