diff options
Diffstat (limited to 'net/core/dev.c')
| -rw-r--r-- | net/core/dev.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 7304ea8a1f1..2a5f5586642 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -203,6 +203,8 @@ static struct list_head offload_base __read_mostly; DEFINE_RWLOCK(dev_base_lock); EXPORT_SYMBOL(dev_base_lock); +DEFINE_SEQLOCK(devnet_rename_seq); + static inline void dev_base_seq_inc(struct net *net) { while (++net->dev_base_seq == 0); @@ -1091,22 +1093,31 @@ int dev_change_name(struct net_device *dev, const char *newname) if (dev->flags & IFF_UP) return -EBUSY; - if (strncmp(newname, dev->name, IFNAMSIZ) == 0) + write_seqlock(&devnet_rename_seq); + + if (strncmp(newname, dev->name, IFNAMSIZ) == 0) { + write_sequnlock(&devnet_rename_seq); return 0; + } memcpy(oldname, dev->name, IFNAMSIZ); err = dev_get_valid_name(net, dev, newname); - if (err < 0) + if (err < 0) { + write_sequnlock(&devnet_rename_seq); return err; + } rollback: ret = device_rename(&dev->dev, dev->name); if (ret) { memcpy(dev->name, oldname, IFNAMSIZ); + write_sequnlock(&devnet_rename_seq); return ret; } + write_sequnlock(&devnet_rename_seq); + write_lock_bh(&dev_base_lock); hlist_del_rcu(&dev->name_hlist); write_unlock_bh(&dev_base_lock); @@ -1124,6 +1135,7 @@ rollback: /* err >= 0 after dev_alloc_name() or stores the first errno */ if (err >= 0) { err = ret; + write_seqlock(&devnet_rename_seq); memcpy(dev->name, oldname, IFNAMSIZ); goto rollback; } else { @@ -4148,6 +4160,7 @@ static int dev_ifname(struct net *net, struct ifreq __user *arg) { struct net_device *dev; struct ifreq ifr; + unsigned seq; /* * Fetch the caller's info block. @@ -4156,6 +4169,8 @@ static int dev_ifname(struct net *net, struct ifreq __user *arg) if (copy_from_user(&ifr, arg, sizeof(struct ifreq))) return -EFAULT; +retry: + seq = read_seqbegin(&devnet_rename_seq); rcu_read_lock(); dev = dev_get_by_index_rcu(net, ifr.ifr_ifindex); if (!dev) { @@ -4165,6 +4180,8 @@ static int dev_ifname(struct net *net, struct ifreq __user *arg) strcpy(ifr.ifr_name, dev->name); rcu_read_unlock(); + if (read_seqretry(&devnet_rename_seq, seq)) + goto retry; if (copy_to_user(arg, &ifr, sizeof(struct ifreq))) return -EFAULT; |