From 485ac57bc1238719b1508f91b0f9eeda4a3c84bb Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Thu, 30 Oct 2008 23:55:16 -0700 Subject: netns: add register_pernet_gen_subsys/unregister_pernet_gen_subsys netns ops which are registered with register_pernet_gen_device() are shutdown strictly before those which are registered with register_pernet_subsys(). Sometimes this leads to opposite (read: buggy) shutdown ordering between two modules. Add register_pernet_gen_subsys()/unregister_pernet_gen_subsys() for modules which aren't elite enough for entry in struct net, and which can't use register_pernet_gen_device(). PPTP conntracking module is such one. Signed-off-by: Alexey Dobriyan Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- net/core/net_namespace.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'net/core') diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index f1d07b5c1e17..1895a4ca9c4f 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -325,6 +325,38 @@ void unregister_pernet_subsys(struct pernet_operations *module) } EXPORT_SYMBOL_GPL(unregister_pernet_subsys); +int register_pernet_gen_subsys(int *id, struct pernet_operations *ops) +{ + int rv; + + mutex_lock(&net_mutex); +again: + rv = ida_get_new_above(&net_generic_ids, 1, id); + if (rv < 0) { + if (rv == -EAGAIN) { + ida_pre_get(&net_generic_ids, GFP_KERNEL); + goto again; + } + goto out; + } + rv = register_pernet_operations(first_device, ops); + if (rv < 0) + ida_remove(&net_generic_ids, *id); + mutex_unlock(&net_mutex); +out: + return rv; +} +EXPORT_SYMBOL_GPL(register_pernet_gen_subsys); + +void unregister_pernet_gen_subsys(int id, struct pernet_operations *ops) +{ + mutex_lock(&net_mutex); + unregister_pernet_operations(ops); + ida_remove(&net_generic_ids, id); + mutex_unlock(&net_mutex); +} +EXPORT_SYMBOL_GPL(unregister_pernet_gen_subsys); + /** * register_pernet_device - register a network namespace device * @ops: pernet operations structure for the subsystem -- cgit v1.2.2 From d1a203eac0ec13cd1c0ba610fe7a55c9bc40473b Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Sat, 1 Nov 2008 21:01:09 -0700 Subject: net: add documentation for skb recycling Commit 04a4bb55bcf35b63d40fd2725e58599ff8310dd7 ("net: add skb_recycle_check() to enable netdriver skb recycling") added a method for network drivers to recycle skbuffs, but while use of this mechanism was documented in the commit message, it should really have been added as a docbook comment as well -- this patch does that. Signed-off-by: Stephen Hemminger Signed-off-by: Lennert Buytenhek Signed-off-by: David S. Miller --- net/core/skbuff.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'net/core') diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 4e22e3a35359..ebb6b94f8af2 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -449,6 +449,18 @@ void kfree_skb(struct sk_buff *skb) __kfree_skb(skb); } +/** + * skb_recycle_check - check if skb can be reused for receive + * @skb: buffer + * @skb_size: minimum receive buffer size + * + * Checks that the skb passed in is not shared or cloned, and + * that it is linear and its head portion at least as large as + * skb_size so that it can be recycled as a receive buffer. + * If these conditions are met, this function does any necessary + * reference count dropping and cleans up the skbuff as if it + * just came from __alloc_skb(). + */ int skb_recycle_check(struct sk_buff *skb, int skb_size) { struct skb_shared_info *shinfo; -- cgit v1.2.2