From eeb74a9d45f781ec6f47b9e0a75a6a427b53f165 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?R=C3=A9mi=20Denis-Courmont?= Date: Wed, 18 Nov 2009 10:08:26 -0800 Subject: [PATCH] Phonet: convert devices list to RCU MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Rémi Denis-Courmont Signed-off-by: David S. Miller --- include/net/phonet/pn_dev.h | 2 +- net/phonet/pn_dev.c | 63 ++++++++++++++++++++++++------------- net/phonet/pn_netlink.c | 6 ++-- 3 files changed, 45 insertions(+), 26 deletions(-) diff --git a/include/net/phonet/pn_dev.h b/include/net/phonet/pn_dev.h index afa7defceb1..d7b989ca3d6 100644 --- a/include/net/phonet/pn_dev.h +++ b/include/net/phonet/pn_dev.h @@ -25,7 +25,7 @@ struct phonet_device_list { struct list_head list; - spinlock_t lock; + struct mutex lock; }; struct phonet_device_list *phonet_device_list(struct net *net); diff --git a/net/phonet/pn_dev.c b/net/phonet/pn_dev.c index d5ad7947d77..d87388c94b0 100644 --- a/net/phonet/pn_dev.c +++ b/net/phonet/pn_dev.c @@ -61,7 +61,8 @@ static struct phonet_device *__phonet_device_alloc(struct net_device *dev) pnd->netdev = dev; bitmap_zero(pnd->addrs, 64); - list_add(&pnd->list, &pndevs->list); + BUG_ON(!mutex_is_locked(&pndevs->lock)); + list_add_rcu(&pnd->list, &pndevs->list); return pnd; } @@ -70,6 +71,7 @@ static struct phonet_device *__phonet_get(struct net_device *dev) struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev)); struct phonet_device *pnd; + BUG_ON(!mutex_is_locked(&pndevs->lock)); list_for_each_entry(pnd, &pndevs->list, list) { if (pnd->netdev == dev) return pnd; @@ -77,6 +79,18 @@ static struct phonet_device *__phonet_get(struct net_device *dev) return NULL; } +static struct phonet_device *__phonet_get_rcu(struct net_device *dev) +{ + struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev)); + struct phonet_device *pnd; + + list_for_each_entry_rcu(pnd, &pndevs->list, list) { + if (pnd->netdev == dev) + return pnd; + } + return NULL; +} + static void phonet_device_destroy(struct net_device *dev) { struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev)); @@ -84,11 +98,11 @@ static void phonet_device_destroy(struct net_device *dev) ASSERT_RTNL(); - spin_lock_bh(&pndevs->lock); + mutex_lock(&pndevs->lock); pnd = __phonet_get(dev); if (pnd) - list_del(&pnd->list); - spin_unlock_bh(&pndevs->lock); + list_del_rcu(&pnd->list); + mutex_unlock(&pndevs->lock); if (pnd) { u8 addr; @@ -106,8 +120,8 @@ struct net_device *phonet_device_get(struct net *net) struct phonet_device *pnd; struct net_device *dev = NULL; - spin_lock_bh(&pndevs->lock); - list_for_each_entry(pnd, &pndevs->list, list) { + rcu_read_lock(); + list_for_each_entry_rcu(pnd, &pndevs->list, list) { dev = pnd->netdev; BUG_ON(!dev); @@ -118,7 +132,7 @@ struct net_device *phonet_device_get(struct net *net) } if (dev) dev_hold(dev); - spin_unlock_bh(&pndevs->lock); + rcu_read_unlock(); return dev; } @@ -128,7 +142,7 @@ int phonet_address_add(struct net_device *dev, u8 addr) struct phonet_device *pnd; int err = 0; - spin_lock_bh(&pndevs->lock); + mutex_lock(&pndevs->lock); /* Find or create Phonet-specific device data */ pnd = __phonet_get(dev); if (pnd == NULL) @@ -137,7 +151,7 @@ int phonet_address_add(struct net_device *dev, u8 addr) err = -ENOMEM; else if (test_and_set_bit(addr >> 2, pnd->addrs)) err = -EEXIST; - spin_unlock_bh(&pndevs->lock); + mutex_unlock(&pndevs->lock); return err; } @@ -147,27 +161,32 @@ int phonet_address_del(struct net_device *dev, u8 addr) struct phonet_device *pnd; int err = 0; - spin_lock_bh(&pndevs->lock); + mutex_lock(&pndevs->lock); pnd = __phonet_get(dev); - if (!pnd || !test_and_clear_bit(addr >> 2, pnd->addrs)) + if (!pnd || !test_and_clear_bit(addr >> 2, pnd->addrs)) { err = -EADDRNOTAVAIL; - else if (bitmap_empty(pnd->addrs, 64)) { - list_del(&pnd->list); + pnd = NULL; + } else if (bitmap_empty(pnd->addrs, 64)) + list_del_rcu(&pnd->list); + else + pnd = NULL; + mutex_unlock(&pndevs->lock); + + if (pnd) { + synchronize_rcu(); kfree(pnd); } - spin_unlock_bh(&pndevs->lock); return err; } /* Gets a source address toward a destination, through a interface. */ u8 phonet_address_get(struct net_device *dev, u8 daddr) { - struct phonet_device_list *pndevs = phonet_device_list(dev_net(dev)); struct phonet_device *pnd; u8 saddr; - spin_lock_bh(&pndevs->lock); - pnd = __phonet_get(dev); + rcu_read_lock(); + pnd = __phonet_get_rcu(dev); if (pnd) { BUG_ON(bitmap_empty(pnd->addrs, 64)); @@ -178,7 +197,7 @@ u8 phonet_address_get(struct net_device *dev, u8 daddr) saddr = find_first_bit(pnd->addrs, 64) << 2; } else saddr = PN_NO_ADDR; - spin_unlock_bh(&pndevs->lock); + rcu_read_unlock(); if (saddr == PN_NO_ADDR) { /* Fallback to another device */ @@ -200,8 +219,8 @@ int phonet_address_lookup(struct net *net, u8 addr) struct phonet_device *pnd; int err = -EADDRNOTAVAIL; - spin_lock_bh(&pndevs->lock); - list_for_each_entry(pnd, &pndevs->list, list) { + rcu_read_lock(); + list_for_each_entry_rcu(pnd, &pndevs->list, list) { /* Don't allow unregistering devices! */ if ((pnd->netdev->reg_state != NETREG_REGISTERED) || ((pnd->netdev->flags & IFF_UP)) != IFF_UP) @@ -213,7 +232,7 @@ int phonet_address_lookup(struct net *net, u8 addr) } } found: - spin_unlock_bh(&pndevs->lock); + rcu_read_unlock(); return err; } @@ -304,7 +323,7 @@ static int phonet_init_net(struct net *net) } INIT_LIST_HEAD(&pnn->pndevs.list); - spin_lock_init(&pnn->pndevs.lock); + mutex_init(&pnn->pndevs.lock); mutex_init(&pnn->routes.lock); net_assign_generic(net, phonet_net_id, pnn); return 0; diff --git a/net/phonet/pn_netlink.c b/net/phonet/pn_netlink.c index 609e509b369..2e6c7eb8e76 100644 --- a/net/phonet/pn_netlink.c +++ b/net/phonet/pn_netlink.c @@ -131,8 +131,8 @@ static int getaddr_dumpit(struct sk_buff *skb, struct netlink_callback *cb) int addr_idx = 0, addr_start_idx = cb->args[1]; pndevs = phonet_device_list(sock_net(skb->sk)); - spin_lock_bh(&pndevs->lock); - list_for_each_entry(pnd, &pndevs->list, list) { + rcu_read_lock(); + list_for_each_entry_rcu(pnd, &pndevs->list, list) { u8 addr; if (dev_idx > dev_start_idx) @@ -154,7 +154,7 @@ static int getaddr_dumpit(struct sk_buff *skb, struct netlink_callback *cb) } out: - spin_unlock_bh(&pndevs->lock); + rcu_read_unlock(); cb->args[0] = dev_idx; cb->args[1] = addr_idx;