linux.git/net/core/dev.c, branch v2.6.17

[NET]: dev.c comment fixes

2006-05-26T20:25:24+00:00

Noticed that dev_alloc_name() comment was incorrect, and more spellung
errors.

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

[NET]: Do sysfs registration as part of register_netdevice.

2006-05-10T20:21:17+00:00

The last step of netdevice registration was being done by a delayed
call, but because it was delayed, it was impossible to return any error
code if the class_device registration failed.

Side effects:
 * one state in registration process is unnecessary.
 * register_netdevice can sleep inside class_device registration/hotplug
 * code in netdev_run_todo only does unregistration so it is simpler.

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

[NET]: Make netdev_chain a raw notifier.

2006-05-09T22:23:03+00:00

From: Alan Stern 

This chain does it's own locking via the RTNL semaphore, and
can also run recursively so adding a new mutex here was causing
deadlocks.

Signed-off-by: David S. Miller

[NET]: Create netdev attribute_groups with class_device_add

2006-05-07T00:56:03+00:00

Atomically create attributes when class device is added. This avoids
the race between registering class_device (which generates hotplug
event), and the creation of attribute groups.

Signed-off-by: Stephen Hemminger 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: David S. Miller

[PATCH] wext: Fix IWENCODEEXT security permissions

2006-04-19T21:25:38+00:00

	Check the permissions when user-space try to read the
encryption parameters via SIOCGIWENCODEEXT. This is trivial and
probably should go in 2.6.17...
	Bug was found by Brian Eaton , thanks !

Signed-off-by: Jean Tourrilhes 
Signed-off-by: John W. Linville

[PATCH] for_each_possible_cpu: network codes

2006-04-11T13:18:31+00:00

for_each_cpu() actually iterates across all possible CPUs.  We've had mistakes
in the past where people were using for_each_cpu() where they should have been
iterating across only online or present CPUs.  This is inefficient and
possibly buggy.

We're renaming for_each_cpu() to for_each_possible_cpu() to avoid this in the
future.

This patch replaces for_each_cpu with for_each_possible_cpu under /net

Signed-off-by: KAMEZAWA Hiroyuki 
Acked-by: "David S. Miller" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[NET]: Fix hotplug race during device registration.

2006-04-10T05:32:48+00:00

From: Thomas de Grenier de Latour 

On Sun, 9 Apr 2006 21:56:59 +0400,
Sergey Vlasov  wrote:

> However, show_address() does not output anything unless
> dev->reg_state == NETREG_REGISTERED - and this state is set by
> netdev_run_todo() only after netdev_register_sysfs() returns, so in
> the meantime (while netdev_register_sysfs() is busy adding the
> "statistics" attribute group) some process may see an empty "address"
> attribute.

I've tried the attached patch, suggested by Sergey Vlasov on
hotplug-devel@, and as far as i can test it works just fine.

Signed-off-by: David S. Miller

[NET] kzalloc: use in alloc_netdev

2006-04-10T05:25:47+00:00

Noticed this use, fixed it.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso 
Signed-off-by: David S. Miller

[NET]: Deinline some larger functions from netdevice.h

2006-03-29T23:57:29+00:00

On a allyesconfig'ured kernel:

Size  Uses Wasted Name and definition
===== ==== ====== ================================================
   95  162  12075 netif_wake_queue      include/linux/netdevice.h
  129   86   9265 dev_kfree_skb_any     include/linux/netdevice.h
  127   56   5885 netif_device_attach   include/linux/netdevice.h
   73   86   4505 dev_kfree_skb_irq     include/linux/netdevice.h
   46   60   1534 netif_device_detach   include/linux/netdevice.h
  119   16   1485 __netif_rx_schedule   include/linux/netdevice.h
  143    5    492 netif_rx_schedule     include/linux/netdevice.h
   81    7    366 netif_schedule        include/linux/netdevice.h

netif_wake_queue is big because __netif_schedule is a big inline:

static inline void __netif_schedule(struct net_device *dev)
{
        if (!test_and_set_bit(__LINK_STATE_SCHED, &dev->state)) {
                unsigned long flags;
                struct softnet_data *sd;

                local_irq_save(flags);
                sd = &__get_cpu_var(softnet_data);
                dev->next_sched = sd->output_queue;
                sd->output_queue = dev;
                raise_softirq_irqoff(NET_TX_SOFTIRQ);
                local_irq_restore(flags);
        }
}

static inline void netif_wake_queue(struct net_device *dev)
{
#ifdef CONFIG_NETPOLL_TRAP
        if (netpoll_trap())
                return;
#endif
        if (test_and_clear_bit(__LINK_STATE_XOFF, &dev->state))
                __netif_schedule(dev);
}

By de-inlining __netif_schedule we are saving a lot of text
at each callsite of netif_wake_queue and netif_schedule.
__netif_rx_schedule is also big, and it makes more sense to keep
both of them out of line.

Patch also deinlines dev_kfree_skb_any. We can deinline dev_kfree_skb_irq
instead... oh well.

netif_device_attach/detach are not hot paths, we can deinline them too.

Signed-off-by: Denis Vlasenko 
Signed-off-by: Andrew Morton 
Signed-off-by: David S. Miller

[PATCH] Notifier chain update: API changes

2006-03-27T16:44:50+00:00

The kernel's implementation of notifier chains is unsafe.  There is no
protection against entries being added to or removed from a chain while the
chain is in use.  The issues were discussed in this thread:

    http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2

We noticed that notifier chains in the kernel fall into two basic usage
classes:

	"Blocking" chains are always called from a process context
	and the callout routines are allowed to sleep;

	"Atomic" chains can be called from an atomic context and
	the callout routines are not allowed to sleep.

We decided to codify this distinction and make it part of the API.  Therefore
this set of patches introduces three new, parallel APIs: one for blocking
notifiers, one for atomic notifiers, and one for "raw" notifiers (which is
really just the old API under a new name).  New kinds of data structures are
used for the heads of the chains, and new routines are defined for
registration, unregistration, and calling a chain.  The three APIs are
explained in include/linux/notifier.h and their implementation is in
kernel/sys.c.

With atomic and blocking chains, the implementation guarantees that the chain
links will not be corrupted and that chain callers will not get messed up by
entries being added or removed.  For raw chains the implementation provides no
guarantees at all; users of this API must provide their own protections.  (The
idea was that situations may come up where the assumptions of the atomic and
blocking APIs are not appropriate, so it should be possible for users to
handle these things in their own way.)

There are some limitations, which should not be too hard to live with.  For
atomic/blocking chains, registration and unregistration must always be done in
a process context since the chain is protected by a mutex/rwsem.  Also, a
callout routine for a non-raw chain must not try to register or unregister
entries on its own chain.  (This did happen in a couple of places and the code
had to be changed to avoid it.)

Since atomic chains may be called from within an NMI handler, they cannot use
spinlocks for synchronization.  Instead we use RCU.  The overhead falls almost
entirely in the unregister routine, which is okay since unregistration is much
less frequent that calling a chain.

Here is the list of chains that we adjusted and their classifications.  None
of them use the raw API, so for the moment it is only a placeholder.

  ATOMIC CHAINS
  -------------
arch/i386/kernel/traps.c:		i386die_chain
arch/ia64/kernel/traps.c:		ia64die_chain
arch/powerpc/kernel/traps.c:		powerpc_die_chain
arch/sparc64/kernel/traps.c:		sparc64die_chain
arch/x86_64/kernel/traps.c:		die_chain
drivers/char/ipmi/ipmi_si_intf.c:	xaction_notifier_list
kernel/panic.c:				panic_notifier_list
kernel/profile.c:			task_free_notifier
net/bluetooth/hci_core.c:		hci_notifier
net/ipv4/netfilter/ip_conntrack_core.c:	ip_conntrack_chain
net/ipv4/netfilter/ip_conntrack_core.c:	ip_conntrack_expect_chain
net/ipv6/addrconf.c:			inet6addr_chain
net/netfilter/nf_conntrack_core.c:	nf_conntrack_chain
net/netfilter/nf_conntrack_core.c:	nf_conntrack_expect_chain
net/netlink/af_netlink.c:		netlink_chain

  BLOCKING CHAINS
  ---------------
arch/powerpc/platforms/pseries/reconfig.c:	pSeries_reconfig_chain
arch/s390/kernel/process.c:		idle_chain
arch/x86_64/kernel/process.c		idle_notifier
drivers/base/memory.c:			memory_chain
drivers/cpufreq/cpufreq.c		cpufreq_policy_notifier_list
drivers/cpufreq/cpufreq.c		cpufreq_transition_notifier_list
drivers/macintosh/adb.c:		adb_client_list
drivers/macintosh/via-pmu.c		sleep_notifier_list
drivers/macintosh/via-pmu68k.c		sleep_notifier_list
drivers/macintosh/windfarm_core.c	wf_client_list
drivers/usb/core/notify.c		usb_notifier_list
drivers/video/fbmem.c			fb_notifier_list
kernel/cpu.c				cpu_chain
kernel/module.c				module_notify_list
kernel/profile.c			munmap_notifier
kernel/profile.c			task_exit_notifier
kernel/sys.c				reboot_notifier_list
net/core/dev.c				netdev_chain
net/decnet/dn_dev.c:			dnaddr_chain
net/ipv4/devinet.c:			inetaddr_chain

It's possible that some of these classifications are wrong.  If they are,
please let us know or submit a patch to fix them.  Note that any chain that
gets called very frequently should be atomic, because the rwsem read-locking
used for blocking chains is very likely to incur cache misses on SMP systems.
(However, if the chain's callout routines may sleep then the chain cannot be
atomic.)

The patch set was written by Alan Stern and Chandra Seetharaman, incorporating
material written by Keith Owens and suggestions from Paul McKenney and Andrew
Morton.

[jes@sgi.com: restructure the notifier chain initialization macros]
Signed-off-by: Alan Stern 
Signed-off-by: Chandra Seetharaman 
Signed-off-by: Jes Sorensen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds