Commit 010a2c65 authored by Stephen Hemminger's avatar Stephen Hemminger

[VLAN]: Use RCU for group operations.

Signed-off-by: default avatarStephen Hemminger <shemminger@osdl.org>
Signed-off-by: default avatarDavid S. Miller <davem@redhat.com>
parent 2c06f076
...@@ -22,6 +22,7 @@ struct sk_buff; ...@@ -22,6 +22,7 @@ struct sk_buff;
struct packet_type; struct packet_type;
struct vlan_collection; struct vlan_collection;
struct vlan_dev_info; struct vlan_dev_info;
struct hlist_node;
#include <linux/proc_fs.h> /* for proc_dir_entry */ #include <linux/proc_fs.h> /* for proc_dir_entry */
#include <linux/netdevice.h> #include <linux/netdevice.h>
...@@ -67,9 +68,9 @@ extern void vlan_ioctl_set(int (*hook)(void __user *)); ...@@ -67,9 +68,9 @@ extern void vlan_ioctl_set(int (*hook)(void __user *));
struct vlan_group { struct vlan_group {
int real_dev_ifindex; /* The ifindex of the ethernet(like) device the vlan is attached to. */ int real_dev_ifindex; /* The ifindex of the ethernet(like) device the vlan is attached to. */
struct hlist_node hlist; /* linked list */
struct net_device *vlan_devices[VLAN_GROUP_ARRAY_LEN]; struct net_device *vlan_devices[VLAN_GROUP_ARRAY_LEN];
struct rcu_head rcu;
struct vlan_group *next; /* the next in the list */
}; };
struct vlan_priority_tci_mapping { struct vlan_priority_tci_mapping {
......
...@@ -38,8 +38,7 @@ ...@@ -38,8 +38,7 @@
/* Global VLAN variables */ /* Global VLAN variables */
/* Our listing of VLAN group(s) */ /* Our listing of VLAN group(s) */
struct vlan_group *vlan_group_hash[VLAN_GRP_HASH_SIZE]; struct hlist_head vlan_group_hash[VLAN_GRP_HASH_SIZE];
spinlock_t vlan_group_lock = SPIN_LOCK_UNLOCKED;
#define vlan_grp_hashfn(IDX) ((((IDX) >> VLAN_GRP_HASH_SHIFT) ^ (IDX)) & VLAN_GRP_HASH_MASK) #define vlan_grp_hashfn(IDX) ((((IDX) >> VLAN_GRP_HASH_SHIFT) ^ (IDX)) & VLAN_GRP_HASH_MASK)
static char vlan_fullname[] = "802.1Q VLAN Support"; static char vlan_fullname[] = "802.1Q VLAN Support";
...@@ -150,8 +149,7 @@ static void __exit vlan_cleanup_module(void) ...@@ -150,8 +149,7 @@ static void __exit vlan_cleanup_module(void)
* references left. * references left.
*/ */
for (i = 0; i < VLAN_GRP_HASH_SIZE; i++) { for (i = 0; i < VLAN_GRP_HASH_SIZE; i++) {
if (vlan_group_hash[i] != NULL) BUG_ON(!hlist_empty(&vlan_group_hash[i]));
BUG();
} }
vlan_proc_cleanup(); vlan_proc_cleanup();
...@@ -161,48 +159,24 @@ static void __exit vlan_cleanup_module(void) ...@@ -161,48 +159,24 @@ static void __exit vlan_cleanup_module(void)
module_init(vlan_proto_init); module_init(vlan_proto_init);
module_exit(vlan_cleanup_module); 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) static struct vlan_group *__vlan_find_group(int real_dev_ifindex)
{ {
struct vlan_group *grp; 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)]; hlist_for_each_entry_rcu(grp, n, &vlan_group_hash[hash], hlist) {
grp != NULL;
grp = grp->next) {
if (grp->real_dev_ifindex == real_dev_ifindex) if (grp->real_dev_ifindex == real_dev_ifindex)
break; return grp;
} }
return grp; return NULL;
}
/* 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;
} }
/* Find the protocol handler. Assumes VID < VLAN_VID_MASK. /* 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, struct net_device *__find_vlan_dev(struct net_device *real_dev,
unsigned short VID) unsigned short VID)
...@@ -215,6 +189,12 @@ struct net_device *__find_vlan_dev(struct net_device *real_dev, ...@@ -215,6 +189,12 @@ struct net_device *__find_vlan_dev(struct net_device *real_dev,
return NULL; 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. /* This returns 0 if everything went fine.
* It will return 1 if the group was killed as a result. * It will return 1 if the group was killed as a result.
* A negative return indicates failure. * A negative return indicates failure.
...@@ -237,9 +217,8 @@ static int unregister_vlan_dev(struct net_device *real_dev, ...@@ -237,9 +217,8 @@ static int unregister_vlan_dev(struct net_device *real_dev,
if (vlan_id >= VLAN_VID_MASK) if (vlan_id >= VLAN_VID_MASK)
return -EINVAL; return -EINVAL;
spin_lock_bh(&vlan_group_lock); ASSERT_RTNL();
grp = __vlan_find_group(real_dev_ifindex); grp = __vlan_find_group(real_dev_ifindex);
spin_unlock_bh(&vlan_group_lock);
ret = 0; ret = 0;
...@@ -279,16 +258,12 @@ static int unregister_vlan_dev(struct net_device *real_dev, ...@@ -279,16 +258,12 @@ static int unregister_vlan_dev(struct net_device *real_dev,
if (real_dev->features & NETIF_F_HW_VLAN_RX) if (real_dev->features & NETIF_F_HW_VLAN_RX)
real_dev->vlan_rx_register(real_dev, NULL); real_dev->vlan_rx_register(real_dev, NULL);
spin_lock_bh(&vlan_group_lock); hlist_del_rcu(&grp->hlist);
__grp_unhash(grp);
spin_unlock_bh(&vlan_group_lock);
/* Free the group, after we have removed it /* Free the group, after all cpu's are done. */
* from the hash. call_rcu(&grp->rcu, vlan_rcu_free);
*/
kfree(grp);
grp = NULL;
grp = NULL;
ret = 1; ret = 1;
} }
} }
...@@ -375,7 +350,6 @@ static struct net_device *register_vlan_device(const char *eth_IF_name, ...@@ -375,7 +350,6 @@ static struct net_device *register_vlan_device(const char *eth_IF_name,
struct vlan_group *grp; struct vlan_group *grp;
struct net_device *new_dev; struct net_device *new_dev;
struct net_device *real_dev; /* the ethernet device */ struct net_device *real_dev; /* the ethernet device */
int r;
char name[IFNAMSIZ]; char name[IFNAMSIZ];
#ifdef VLAN_DEBUG #ifdef VLAN_DEBUG
...@@ -424,11 +398,7 @@ static struct net_device *register_vlan_device(const char *eth_IF_name, ...@@ -424,11 +398,7 @@ static struct net_device *register_vlan_device(const char *eth_IF_name,
if (!(real_dev->flags & IFF_UP)) if (!(real_dev->flags & IFF_UP))
goto out_unlock; goto out_unlock;
spin_lock_bh(&vlan_group_lock); if (__find_vlan_dev(real_dev, VLAN_ID) != NULL) {
r = (__find_vlan_dev(real_dev, VLAN_ID) != NULL);
spin_unlock_bh(&vlan_group_lock);
if (r) {
/* was already registered. */ /* was already registered. */
printk(VLAN_DBG "%s: ALREADY had VLAN registered\n", __FUNCTION__); printk(VLAN_DBG "%s: ALREADY had VLAN registered\n", __FUNCTION__);
goto out_unlock; goto out_unlock;
...@@ -527,9 +497,7 @@ static struct net_device *register_vlan_device(const char *eth_IF_name, ...@@ -527,9 +497,7 @@ static struct net_device *register_vlan_device(const char *eth_IF_name,
/* So, got the sucker initialized, now lets place /* So, got the sucker initialized, now lets place
* it into our local structure. * it into our local structure.
*/ */
spin_lock_bh(&vlan_group_lock);
grp = __vlan_find_group(real_dev->ifindex); grp = __vlan_find_group(real_dev->ifindex);
spin_unlock_bh(&vlan_group_lock);
/* Note, we are running under the RTNL semaphore /* Note, we are running under the RTNL semaphore
* so it cannot "appear" on us. * so it cannot "appear" on us.
...@@ -543,9 +511,8 @@ static struct net_device *register_vlan_device(const char *eth_IF_name, ...@@ -543,9 +511,8 @@ static struct net_device *register_vlan_device(const char *eth_IF_name,
memset(grp, 0, sizeof(struct vlan_group)); memset(grp, 0, sizeof(struct vlan_group));
grp->real_dev_ifindex = real_dev->ifindex; grp->real_dev_ifindex = real_dev->ifindex;
spin_lock_bh(&vlan_group_lock); hlist_add_head_rcu(&grp->hlist,
__grp_hash(grp); &vlan_group_hash[vlan_grp_hashfn(real_dev->ifindex)]);
spin_unlock_bh(&vlan_group_lock);
if (real_dev->features & NETIF_F_HW_VLAN_RX) if (real_dev->features & NETIF_F_HW_VLAN_RX)
real_dev->vlan_rx_register(real_dev, grp); real_dev->vlan_rx_register(real_dev, grp);
...@@ -587,14 +554,10 @@ static struct net_device *register_vlan_device(const char *eth_IF_name, ...@@ -587,14 +554,10 @@ static struct net_device *register_vlan_device(const char *eth_IF_name,
static int vlan_device_event(struct notifier_block *unused, unsigned long event, void *ptr) static int vlan_device_event(struct notifier_block *unused, unsigned long event, void *ptr)
{ {
struct net_device *dev = (struct net_device *)(ptr); struct net_device *dev = ptr;
struct vlan_group *grp = NULL; struct vlan_group *grp = __vlan_find_group(dev->ifindex);
int i, flgs; int i, flgs;
struct net_device *vlandev = NULL; struct net_device *vlandev;
spin_lock_bh(&vlan_group_lock);
grp = __vlan_find_group(dev->ifindex);
spin_unlock_bh(&vlan_group_lock);
if (!grp) if (!grp)
goto out; goto out;
......
...@@ -33,8 +33,7 @@ extern unsigned short vlan_name_type; ...@@ -33,8 +33,7 @@ extern unsigned short vlan_name_type;
#define VLAN_GRP_HASH_SHIFT 5 #define VLAN_GRP_HASH_SHIFT 5
#define VLAN_GRP_HASH_SIZE (1 << VLAN_GRP_HASH_SHIFT) #define VLAN_GRP_HASH_SIZE (1 << VLAN_GRP_HASH_SHIFT)
#define VLAN_GRP_HASH_MASK (VLAN_GRP_HASH_SIZE - 1) #define VLAN_GRP_HASH_MASK (VLAN_GRP_HASH_SIZE - 1)
extern struct vlan_group *vlan_group_hash[VLAN_GRP_HASH_SIZE]; extern struct hlist_head vlan_group_hash[VLAN_GRP_HASH_SIZE];
extern spinlock_t vlan_group_lock;
/* Find a VLAN device by the MAC address of its Ethernet device, and /* 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 * it's VLAN ID. The default configuration is to have VLAN's scope
...@@ -44,10 +43,8 @@ extern spinlock_t vlan_group_lock; ...@@ -44,10 +43,8 @@ extern spinlock_t vlan_group_lock;
* NOT follow the spec for VLANs, but may be useful for doing very * NOT follow the spec for VLANs, but may be useful for doing very
* large quantities of VLAN MUX/DEMUX onto FrameRelay or ATM PVCs. * large quantities of VLAN MUX/DEMUX onto FrameRelay or ATM PVCs.
* *
* Must be invoked with vlan_group_lock held and that lock MUST NOT * Must be invoked with rcu_read_lock (ie preempt disabled)
* be dropped until a reference is obtained on the returned device. * or with RTNL.
* You may drop the lock earlier if you are running under the RTNL
* semaphore, however.
*/ */
struct net_device *__find_vlan_dev(struct net_device* real_dev, struct net_device *__find_vlan_dev(struct net_device* real_dev,
unsigned short VID); /* vlan.c */ unsigned short VID); /* vlan.c */
......
...@@ -138,15 +138,15 @@ int vlan_skb_recv(struct sk_buff *skb, struct net_device *dev, ...@@ -138,15 +138,15 @@ int vlan_skb_recv(struct sk_buff *skb, struct net_device *dev,
/* We have 12 bits of vlan ID. /* 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 * reference to the device (netif_rx does that) or we
* fail. * fail.
*/ */
spin_lock_bh(&vlan_group_lock); rcu_read_lock();
skb->dev = __find_vlan_dev(dev, vid); skb->dev = __find_vlan_dev(dev, vid);
if (!skb->dev) { if (!skb->dev) {
spin_unlock_bh(&vlan_group_lock); rcu_read_unlock();
#ifdef VLAN_DEBUG #ifdef VLAN_DEBUG
printk(VLAN_DBG "%s: ERROR: No net_device for VID: %i on dev: %s [%i]\n", 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, ...@@ -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) { if (dev != VLAN_DEV_INFO(skb->dev)->real_dev) {
spin_unlock_bh(&vlan_group_lock); rcu_read_unlock();
#ifdef VLAN_DEBUG #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", 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, ...@@ -244,7 +244,7 @@ int vlan_skb_recv(struct sk_buff *skb, struct net_device *dev,
/* TODO: Add a more specific counter here. */ /* TODO: Add a more specific counter here. */
stats->rx_errors++; stats->rx_errors++;
} }
spin_unlock_bh(&vlan_group_lock); rcu_read_lock();
return 0; return 0;
} }
...@@ -273,7 +273,7 @@ int vlan_skb_recv(struct sk_buff *skb, struct net_device *dev, ...@@ -273,7 +273,7 @@ int vlan_skb_recv(struct sk_buff *skb, struct net_device *dev,
/* TODO: Add a more specific counter here. */ /* TODO: Add a more specific counter here. */
stats->rx_errors++; stats->rx_errors++;
} }
spin_unlock_bh(&vlan_group_lock); rcu_read_unlock();
return 0; return 0;
} }
...@@ -296,7 +296,7 @@ int vlan_skb_recv(struct sk_buff *skb, struct net_device *dev, ...@@ -296,7 +296,7 @@ int vlan_skb_recv(struct sk_buff *skb, struct net_device *dev,
/* TODO: Add a more specific counter here. */ /* TODO: Add a more specific counter here. */
stats->rx_errors++; stats->rx_errors++;
} }
spin_unlock_bh(&vlan_group_lock); rcu_read_unlock();
return 0; return 0;
} }
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment