[patch net-next 2/2] net: introduce netif_addr_lock_nested() and call if when appropriate
From: Jiri Pirko <hidden>
Date: 2012-01-09 16:18:42
Subsystem:
networking drivers, networking [general], the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
dev_uc_sync() and dev_mc_sync() are acquiring netif_addr_lock for destination device of synchronization. Since netif_addr_lock is already held at the time for source device, this triggers depmod deathlock warning. There's no way this deathlock can happen so use spin_lock_nested() to silence the warning. Signed-off-by: Jiri Pirko <redacted> --- include/linux/netdevice.h | 5 +++++ net/core/dev_addr_lists.c | 12 ++++++------ 2 files changed, 11 insertions(+), 6 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index a1d1095..656fade 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h@@ -2450,6 +2450,11 @@ static inline void netif_addr_lock(struct net_device *dev) spin_lock(&dev->addr_list_lock); } +static inline void netif_addr_lock_nested(struct net_device *dev) +{ + spin_lock_nested(&dev->addr_list_lock, DENTRY_D_LOCK_NESTED); +} + static inline void netif_addr_lock_bh(struct net_device *dev) { spin_lock_bh(&dev->addr_list_lock);
diff --git a/net/core/dev_addr_lists.c b/net/core/dev_addr_lists.c
index c34ce9f..29c07fe 100644
--- a/net/core/dev_addr_lists.c
+++ b/net/core/dev_addr_lists.c@@ -439,11 +439,11 @@ int dev_uc_sync(struct net_device *to, struct net_device *from) if (to->addr_len != from->addr_len) return -EINVAL; - netif_addr_lock_bh(to); + netif_addr_lock_nested(to); err = __hw_addr_sync(&to->uc, &from->uc, to->addr_len); if (!err) __dev_set_rx_mode(to); - netif_addr_unlock_bh(to); + netif_addr_unlock(to); return err; } EXPORT_SYMBOL(dev_uc_sync);
@@ -463,7 +463,7 @@ void dev_uc_unsync(struct net_device *to, struct net_device *from) return; netif_addr_lock_bh(from); - netif_addr_lock(to); + netif_addr_lock_nested(to); __hw_addr_unsync(&to->uc, &from->uc, to->addr_len); __dev_set_rx_mode(to); netif_addr_unlock(to);
@@ -602,11 +602,11 @@ int dev_mc_sync(struct net_device *to, struct net_device *from) if (to->addr_len != from->addr_len) return -EINVAL; - netif_addr_lock_bh(to); + netif_addr_lock_nested(to); err = __hw_addr_sync(&to->mc, &from->mc, to->addr_len); if (!err) __dev_set_rx_mode(to); - netif_addr_unlock_bh(to); + netif_addr_unlock(to); return err; } EXPORT_SYMBOL(dev_mc_sync);
@@ -626,7 +626,7 @@ void dev_mc_unsync(struct net_device *to, struct net_device *from) return; netif_addr_lock_bh(from); - netif_addr_lock(to); + netif_addr_lock_nested(to); __hw_addr_unsync(&to->mc, &from->mc, to->addr_len); __dev_set_rx_mode(to); netif_addr_unlock(to);
--
1.7.6