From bb69ae049fcc986fcd742eb90ca0d44a7a49c9f1 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 7 Jun 2010 11:42:13 +0000 Subject: anycast: Some RCU conversions - dev_get_by_flags() changed to dev_get_by_flags_rcu() - ipv6_sock_ac_join() dont touch dev & idev refcounts - ipv6_sock_ac_drop() dont touch dev & idev refcounts - ipv6_sock_ac_close() dont touch dev & idev refcounts - ipv6_dev_ac_dec() dount touch idev refcount - ipv6_chk_acast_addr() dont touch idev refcount Signed-off-by: Eric Dumazet CC: Hideaki YOSHIFUJI Signed-off-by: David S. Miller --- include/linux/netdevice.h | 4 +-- net/core/dev.c | 14 +++----- net/ipv6/anycast.c | 90 ++++++++++++++++++++++------------------------- 3 files changed, 49 insertions(+), 59 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 5156b806924..c319f28d699 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1271,8 +1271,8 @@ extern void dev_add_pack(struct packet_type *pt); extern void dev_remove_pack(struct packet_type *pt); extern void __dev_remove_pack(struct packet_type *pt); -extern struct net_device *dev_get_by_flags(struct net *net, unsigned short flags, - unsigned short mask); +extern struct net_device *dev_get_by_flags_rcu(struct net *net, unsigned short flags, + unsigned short mask); extern struct net_device *dev_get_by_name(struct net *net, const char *name); extern struct net_device *dev_get_by_name_rcu(struct net *net, const char *name); extern struct net_device *__dev_get_by_name(struct net *net, const char *name); diff --git a/net/core/dev.c b/net/core/dev.c index c8d127718ff..6f330cee79a 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -803,35 +803,31 @@ struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type) EXPORT_SYMBOL(dev_getfirstbyhwtype); /** - * dev_get_by_flags - find any device with given flags + * dev_get_by_flags_rcu - find any device with given flags * @net: the applicable net namespace * @if_flags: IFF_* values * @mask: bitmask of bits in if_flags to check * * Search for any interface with the given flags. Returns NULL if a device - * is not found or a pointer to the device. The device returned has - * had a reference added and the pointer is safe until the user calls - * dev_put to indicate they have finished with it. + * is not found or a pointer to the device. Must be called inside + * rcu_read_lock(), and result refcount is unchanged. */ -struct net_device *dev_get_by_flags(struct net *net, unsigned short if_flags, +struct net_device *dev_get_by_flags_rcu(struct net *net, unsigned short if_flags, unsigned short mask) { struct net_device *dev, *ret; ret = NULL; - rcu_read_lock(); for_each_netdev_rcu(net, dev) { if (((dev->flags ^ if_flags) & mask) == 0) { - dev_hold(dev); ret = dev; break; } } - rcu_read_unlock(); return ret; } -EXPORT_SYMBOL(dev_get_by_flags); +EXPORT_SYMBOL(dev_get_by_flags_rcu); /** * dev_valid_name - check if name is okay for network device diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c index b5b07054508..f058fbd808c 100644 --- a/net/ipv6/anycast.c +++ b/net/ipv6/anycast.c @@ -77,41 +77,40 @@ int ipv6_sock_ac_join(struct sock *sk, int ifindex, struct in6_addr *addr) pac->acl_next = NULL; ipv6_addr_copy(&pac->acl_addr, addr); + rcu_read_lock(); if (ifindex == 0) { struct rt6_info *rt; rt = rt6_lookup(net, addr, NULL, 0, 0); if (rt) { dev = rt->rt6i_dev; - dev_hold(dev); dst_release(&rt->u.dst); } else if (ishost) { err = -EADDRNOTAVAIL; - goto out_free_pac; + goto error; } else { /* router, no matching interface: just pick one */ - - dev = dev_get_by_flags(net, IFF_UP, IFF_UP|IFF_LOOPBACK); + dev = dev_get_by_flags_rcu(net, IFF_UP, + IFF_UP | IFF_LOOPBACK); } } else - dev = dev_get_by_index(net, ifindex); + dev = dev_get_by_index_rcu(net, ifindex); if (dev == NULL) { err = -ENODEV; - goto out_free_pac; + goto error; } - idev = in6_dev_get(dev); + idev = __in6_dev_get(dev); if (!idev) { if (ifindex) err = -ENODEV; else err = -EADDRNOTAVAIL; - goto out_dev_put; + goto error; } /* reset ishost, now that we have a specific device */ ishost = !idev->cnf.forwarding; - in6_dev_put(idev); pac->acl_ifindex = dev->ifindex; @@ -124,26 +123,22 @@ int ipv6_sock_ac_join(struct sock *sk, int ifindex, struct in6_addr *addr) if (ishost) err = -EADDRNOTAVAIL; if (err) - goto out_dev_put; + goto error; } err = ipv6_dev_ac_inc(dev, addr); - if (err) - goto out_dev_put; - - write_lock_bh(&ipv6_sk_ac_lock); - pac->acl_next = np->ipv6_ac_list; - np->ipv6_ac_list = pac; - write_unlock_bh(&ipv6_sk_ac_lock); - - dev_put(dev); - - return 0; + if (!err) { + write_lock_bh(&ipv6_sk_ac_lock); + pac->acl_next = np->ipv6_ac_list; + np->ipv6_ac_list = pac; + write_unlock_bh(&ipv6_sk_ac_lock); + pac = NULL; + } -out_dev_put: - dev_put(dev); -out_free_pac: - sock_kfree_s(sk, pac, sizeof(*pac)); +error: + rcu_read_unlock(); + if (pac) + sock_kfree_s(sk, pac, sizeof(*pac)); return err; } @@ -176,11 +171,12 @@ int ipv6_sock_ac_drop(struct sock *sk, int ifindex, struct in6_addr *addr) write_unlock_bh(&ipv6_sk_ac_lock); - dev = dev_get_by_index(net, pac->acl_ifindex); - if (dev) { + rcu_read_lock(); + dev = dev_get_by_index_rcu(net, pac->acl_ifindex); + if (dev) ipv6_dev_ac_dec(dev, &pac->acl_addr); - dev_put(dev); - } + rcu_read_unlock(); + sock_kfree_s(sk, pac, sizeof(*pac)); return 0; } @@ -199,13 +195,12 @@ void ipv6_sock_ac_close(struct sock *sk) write_unlock_bh(&ipv6_sk_ac_lock); prev_index = 0; + rcu_read_lock(); while (pac) { struct ipv6_ac_socklist *next = pac->acl_next; if (pac->acl_ifindex != prev_index) { - if (dev) - dev_put(dev); - dev = dev_get_by_index(net, pac->acl_ifindex); + dev = dev_get_by_index_rcu(net, pac->acl_ifindex); prev_index = pac->acl_ifindex; } if (dev) @@ -213,8 +208,7 @@ void ipv6_sock_ac_close(struct sock *sk) sock_kfree_s(sk, pac, sizeof(*pac)); pac = next; } - if (dev) - dev_put(dev); + rcu_read_unlock(); } #if 0 @@ -363,33 +357,32 @@ int __ipv6_dev_ac_dec(struct inet6_dev *idev, struct in6_addr *addr) return 0; } +/* called with rcu_read_lock() */ static int ipv6_dev_ac_dec(struct net_device *dev, struct in6_addr *addr) { - int ret; - struct inet6_dev *idev = in6_dev_get(dev); + struct inet6_dev *idev = __in6_dev_get(dev); + if (idev == NULL) return -ENODEV; - ret = __ipv6_dev_ac_dec(idev, addr); - in6_dev_put(idev); - return ret; + return __ipv6_dev_ac_dec(idev, addr); } /* * check if the interface has this anycast address + * called with rcu_read_lock() */ static int ipv6_chk_acast_dev(struct net_device *dev, struct in6_addr *addr) { struct inet6_dev *idev; struct ifacaddr6 *aca; - idev = in6_dev_get(dev); + idev = __in6_dev_get(dev); if (idev) { read_lock_bh(&idev->lock); for (aca = idev->ac_list; aca; aca = aca->aca_next) if (ipv6_addr_equal(&aca->aca_addr, addr)) break; read_unlock_bh(&idev->lock); - in6_dev_put(idev); return aca != NULL; } return 0; @@ -403,14 +396,15 @@ int ipv6_chk_acast_addr(struct net *net, struct net_device *dev, { int found = 0; - if (dev) - return ipv6_chk_acast_dev(dev, addr); rcu_read_lock(); - for_each_netdev_rcu(net, dev) - if (ipv6_chk_acast_dev(dev, addr)) { - found = 1; - break; - } + if (dev) + found = ipv6_chk_acast_dev(dev, addr); + else + for_each_netdev_rcu(net, dev) + if (ipv6_chk_acast_dev(dev, addr)) { + found = 1; + break; + } rcu_read_unlock(); return found; } -- cgit v1.2.3-70-g09d2