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authorCong Wang <amwang@redhat.com>2013-01-14 23:34:06 +0000
committerDavid S. Miller <davem@davemloft.net>2013-01-16 15:26:03 -0500
commitf92d318023ff70a273690a91568597168ac32f05 (patch)
tree91d64d43a5111cfbc689956e27017c144c9205ba /net/core/netpoll.c
parent7db11f7596e0e54f982b1897f8233056e5c67a7d (diff)
netpoll: fix a rtnl lock assertion failure
v4: hold rtnl lock for the whole netpoll_setup() v3: remove the comment v2: use RCU read lock This patch fixes the following warning: [ 72.013864] RTNL: assertion failed at net/core/dev.c (4955) [ 72.017758] Pid: 668, comm: netpoll-prep-v6 Not tainted 3.8.0-rc1+ #474 [ 72.019582] Call Trace: [ 72.020295] [<ffffffff8176653d>] netdev_master_upper_dev_get+0x35/0x58 [ 72.022545] [<ffffffff81784edd>] netpoll_setup+0x61/0x340 [ 72.024846] [<ffffffff815d837e>] store_enabled+0x82/0xc3 [ 72.027466] [<ffffffff815d7e51>] netconsole_target_attr_store+0x35/0x37 [ 72.029348] [<ffffffff811c3479>] configfs_write_file+0xe2/0x10c [ 72.030959] [<ffffffff8115d239>] vfs_write+0xaf/0xf6 [ 72.032359] [<ffffffff81978a05>] ? sysret_check+0x22/0x5d [ 72.033824] [<ffffffff8115d453>] sys_write+0x5c/0x84 [ 72.035328] [<ffffffff819789d9>] system_call_fastpath+0x16/0x1b In case of other races, hold rtnl lock for the entire netpoll_setup() function. Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Jiri Pirko <jiri@resnulli.us> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Cong Wang <amwang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/netpoll.c')
-rw-r--r--net/core/netpoll.c24
1 files changed, 10 insertions, 14 deletions
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index 9f0506726101..a5ad1c1c4b18 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -1048,11 +1048,13 @@ int netpoll_setup(struct netpoll *np)
struct in_device *in_dev;
int err;
+ rtnl_lock();
if (np->dev_name)
- ndev = dev_get_by_name(&init_net, np->dev_name);
+ ndev = __dev_get_by_name(&init_net, np->dev_name);
if (!ndev) {
np_err(np, "%s doesn't exist, aborting\n", np->dev_name);
- return -ENODEV;
+ err = -ENODEV;
+ goto unlock;
}
if (netdev_master_upper_dev_get(ndev)) {
@@ -1066,15 +1068,14 @@ int netpoll_setup(struct netpoll *np)
np_info(np, "device %s not up yet, forcing it\n", np->dev_name);
- rtnl_lock();
err = dev_open(ndev);
- rtnl_unlock();
if (err) {
np_err(np, "failed to open %s\n", ndev->name);
goto put;
}
+ rtnl_unlock();
atleast = jiffies + HZ/10;
atmost = jiffies + carrier_timeout * HZ;
while (!netif_carrier_ok(ndev)) {
@@ -1094,16 +1095,14 @@ int netpoll_setup(struct netpoll *np)
np_notice(np, "carrier detect appears untrustworthy, waiting 4 seconds\n");
msleep(4000);
}
+ rtnl_lock();
}
if (!np->local_ip.ip) {
if (!np->ipv6) {
- rcu_read_lock();
- in_dev = __in_dev_get_rcu(ndev);
-
+ in_dev = __in_dev_get_rtnl(ndev);
if (!in_dev || !in_dev->ifa_list) {
- rcu_read_unlock();
np_err(np, "no IP address for %s, aborting\n",
np->dev_name);
err = -EDESTADDRREQ;
@@ -1111,14 +1110,12 @@ int netpoll_setup(struct netpoll *np)
}
np->local_ip.ip = in_dev->ifa_list->ifa_local;
- rcu_read_unlock();
np_info(np, "local IP %pI4\n", &np->local_ip.ip);
} else {
#if IS_ENABLED(CONFIG_IPV6)
struct inet6_dev *idev;
err = -EDESTADDRREQ;
- rcu_read_lock();
idev = __in6_dev_get(ndev);
if (idev) {
struct inet6_ifaddr *ifp;
@@ -1133,7 +1130,6 @@ int netpoll_setup(struct netpoll *np)
}
read_unlock_bh(&idev->lock);
}
- rcu_read_unlock();
if (err) {
np_err(np, "no IPv6 address for %s, aborting\n",
np->dev_name);
@@ -1151,17 +1147,17 @@ int netpoll_setup(struct netpoll *np)
/* fill up the skb queue */
refill_skbs();
- rtnl_lock();
err = __netpoll_setup(np, ndev, GFP_KERNEL);
- rtnl_unlock();
-
if (err)
goto put;
+ rtnl_unlock();
return 0;
put:
dev_put(ndev);
+unlock:
+ rtnl_unlock();
return err;
}
EXPORT_SYMBOL(netpoll_setup);