system/linux
system/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux synced 2024-09-20 11:07:02 +00:00
Code Issues Packages Projects Releases Wiki Activity

[NETPOLL]: allow multiple netpoll_clients to register against one interface

Browse source 
This patch provides support for registering multiple netpoll clients to the
same network device.  Only one of these clients may register an rx_hook,
however.  In practice, this restriction has not been problematic.  It is
worth mentioning, though, that the current design can be easily extended to
allow for the registration of multiple rx_hooks.

The basic idea of the patch is that the rx_np pointer in the netpoll_info
structure points to the struct netpoll that has rx_hook filled in.  Aside
from this one case, there is no need for a pointer from the struct
net_device to an individual struct netpoll.

A lock is introduced to protect the setting and clearing of the np_rx
pointer.  The pointer will only be cleared upon netpoll client module
removal, and the lock should be uncontested.

Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jeff Moyer 2005-06-22 22:05:59 -07:00 committed by David S. Miller
parent 115c1d6e61
commit fbeec2e155
2 changed files with 41 additions and 13 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

15
include/linux/netpoll.h
View file

@ -27,7 +27,8 @@ struct netpoll_info {
spinlock_t poll_lock; spinlock_t poll_lock;
int poll_owner; int poll_owner;
int rx_flags; int rx_flags;
struct netpoll *np; spinlock_t rx_lock;
struct netpoll *rx_np; /* netpoll that registered an rx_hook */
}; };
void netpoll_poll(struct netpoll *np); void netpoll_poll(struct netpoll *np);
@ -44,11 +45,19 @@ void netpoll_queue(struct sk_buff *skb);
static inline int netpoll_rx(struct sk_buff *skb) static inline int netpoll_rx(struct sk_buff *skb)
{ {
struct netpoll_info *npinfo = skb->dev->npinfo; struct netpoll_info *npinfo = skb->dev->npinfo;
unsigned long flags;
int ret = 0;
if (!npinfo || !npinfo->rx_flags) if (!npinfo || (!npinfo->rx_np && !npinfo->rx_flags))
return 0; return 0;
return npinfo->np && __netpoll_rx(skb); spin_lock_irqsave(&npinfo->rx_lock, flags);
/* check rx_flags again with the lock held */
if (npinfo->rx_flags && __netpoll_rx(skb))
ret = 1;
spin_unlock_irqrestore(&npinfo->rx_lock, flags);
return ret;
} }
static inline void netpoll_poll_lock(struct net_device *dev) static inline void netpoll_poll_lock(struct net_device *dev)

39
net/core/netpoll.c
View file

@ -349,11 +349,15 @@ static void arp_reply(struct sk_buff *skb)
unsigned char *arp_ptr; unsigned char *arp_ptr;
int size, type = ARPOP_REPLY, ptype = ETH_P_ARP; int size, type = ARPOP_REPLY, ptype = ETH_P_ARP;
u32 sip, tip; u32 sip, tip;
unsigned long flags;
struct sk_buff *send_skb; struct sk_buff *send_skb;
struct netpoll *np = NULL; struct netpoll *np = NULL;
if (npinfo) spin_lock_irqsave(&npinfo->rx_lock, flags);
np = npinfo->np; if (npinfo->rx_np && npinfo->rx_np->dev == skb->dev)
np = npinfo->rx_np;
spin_unlock_irqrestore(&npinfo->rx_lock, flags);
if (!np) if (!np)
return; return;
@ -436,9 +440,9 @@ int __netpoll_rx(struct sk_buff *skb)
int proto, len, ulen; int proto, len, ulen;
struct iphdr *iph; struct iphdr *iph;
struct udphdr *uh; struct udphdr *uh;
struct netpoll *np = skb->dev->npinfo->np; struct netpoll *np = skb->dev->npinfo->rx_np;
if (!np->rx_hook) if (!np)
goto out; goto out;
if (skb->dev->type != ARPHRD_ETHER) if (skb->dev->type != ARPHRD_ETHER)
goto out; goto out;
@ -619,6 +623,7 @@ int netpoll_setup(struct netpoll *np)
struct net_device *ndev = NULL; struct net_device *ndev = NULL;
struct in_device *in_dev; struct in_device *in_dev;
struct netpoll_info *npinfo; struct netpoll_info *npinfo;
unsigned long flags;
if (np->dev_name) if (np->dev_name)
ndev = dev_get_by_name(np->dev_name); ndev = dev_get_by_name(np->dev_name);
@ -634,9 +639,10 @@ int netpoll_setup(struct netpoll *np)
if (!npinfo) if (!npinfo)
goto release; goto release;
npinfo->np = NULL; npinfo->rx_np = NULL;
npinfo->poll_lock = SPIN_LOCK_UNLOCKED; npinfo->poll_lock = SPIN_LOCK_UNLOCKED;
npinfo->poll_owner = -1; npinfo->poll_owner = -1;
npinfo->rx_lock = SPIN_LOCK_UNLOCKED;
} else } else
npinfo = ndev->npinfo; npinfo = ndev->npinfo;
@ -706,9 +712,13 @@ int netpoll_setup(struct netpoll *np)
np->name, HIPQUAD(np->local_ip)); np->name, HIPQUAD(np->local_ip));
} }
if(np->rx_hook) if (np->rx_hook) {
npinfo->rx_flags = NETPOLL_RX_ENABLED; spin_lock_irqsave(&npinfo->rx_lock, flags);
npinfo->np = np; npinfo->rx_flags |= NETPOLL_RX_ENABLED;
npinfo->rx_np = np;
spin_unlock_irqrestore(&npinfo->rx_lock, flags);
}
/* last thing to do is link it to the net device structure */
ndev->npinfo = npinfo; ndev->npinfo = npinfo;
return 0; return 0;
@ -723,11 +733,20 @@ int netpoll_setup(struct netpoll *np)
void netpoll_cleanup(struct netpoll *np) void netpoll_cleanup(struct netpoll *np)
{ {
struct netpoll_info *npinfo;
unsigned long flags;
if (np->dev) { if (np->dev) {
if (np->dev->npinfo) npinfo = np->dev->npinfo;
np->dev->npinfo->np = NULL; if (npinfo && npinfo->rx_np == np) {
spin_lock_irqsave(&npinfo->rx_lock, flags);
npinfo->rx_np = NULL;
npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
spin_unlock_irqrestore(&npinfo->rx_lock, flags);
}
dev_put(np->dev); dev_put(np->dev);
} }
np->dev = NULL; np->dev = NULL;
} }