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author | Yossi Etigin <yossi.openib@gmail.com> | 2008-09-16 11:57:45 -0700 |
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committer | Roland Dreier <rolandd@cisco.com> | 2008-09-16 11:57:45 -0700 |
commit | e8224e4b804b4fd26723191c1891101a5959bb8a (patch) | |
tree | 94aa1274989fca8154bd3912d5f73239e705e7a3 /drivers | |
parent | 1941246dd98089dd637f44d3bd4f6cc1c61aa9e4 (diff) | |
download | kernel_samsung_smdk4412-e8224e4b804b4fd26723191c1891101a5959bb8a.zip kernel_samsung_smdk4412-e8224e4b804b4fd26723191c1891101a5959bb8a.tar.gz kernel_samsung_smdk4412-e8224e4b804b4fd26723191c1891101a5959bb8a.tar.bz2 |
IPoIB: Fix deadlock on RTNL between bcast join comp and ipoib_stop()
Taking rtnl_lock in ipoib_mcast_join_complete() causes a deadlock with
ipoib_stop(). We avoid it by scheduling the piece of code that takes
the lock on ipoib_workqueue instead of executing it directly. This
works because we only flush the ipoib_workqueue with the RTNL not held.
The deadlock happens because ipoib_stop() calls ipoib_ib_dev_down()
which calls ipoib_mcast_dev_flush(), which calls ipoib_mcast_free(),
which calls ipoib_mcast_leave(). The latter calls
ib_sa_free_multicast(), and this waits until the multicast completion
handler finishes. This handler is ipoib_mcast_join_complete(), which
waits for the rtnl_lock(), which was already taken by ipoib_stop().
This bug was introduced in commit a77a57a1 ("IPoIB: Fix deadlock on
RTNL in ipoib_stop()").
Signed-off-by: Yossi Etigin <yosefe@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/infiniband/ulp/ipoib/ipoib.h | 2 | ||||
-rw-r--r-- | drivers/infiniband/ulp/ipoib/ipoib_main.c | 1 | ||||
-rw-r--r-- | drivers/infiniband/ulp/ipoib/ipoib_multicast.c | 31 |
3 files changed, 24 insertions, 10 deletions
diff --git a/drivers/infiniband/ulp/ipoib/ipoib.h b/drivers/infiniband/ulp/ipoib/ipoib.h index b0ffc9a..05eb41b 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib.h +++ b/drivers/infiniband/ulp/ipoib/ipoib.h @@ -293,6 +293,7 @@ struct ipoib_dev_priv { struct delayed_work pkey_poll_task; struct delayed_work mcast_task; + struct work_struct carrier_on_task; struct work_struct flush_light; struct work_struct flush_normal; struct work_struct flush_heavy; @@ -464,6 +465,7 @@ int ipoib_dev_init(struct net_device *dev, struct ib_device *ca, int port); void ipoib_dev_cleanup(struct net_device *dev); void ipoib_mcast_join_task(struct work_struct *work); +void ipoib_mcast_carrier_on_task(struct work_struct *work); void ipoib_mcast_send(struct net_device *dev, void *mgid, struct sk_buff *skb); void ipoib_mcast_restart_task(struct work_struct *work); diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c index 7e9e218..1b1df5c 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_main.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c @@ -1075,6 +1075,7 @@ static void ipoib_setup(struct net_device *dev) INIT_DELAYED_WORK(&priv->pkey_poll_task, ipoib_pkey_poll); INIT_DELAYED_WORK(&priv->mcast_task, ipoib_mcast_join_task); + INIT_WORK(&priv->carrier_on_task, ipoib_mcast_carrier_on_task); INIT_WORK(&priv->flush_light, ipoib_ib_dev_flush_light); INIT_WORK(&priv->flush_normal, ipoib_ib_dev_flush_normal); INIT_WORK(&priv->flush_heavy, ipoib_ib_dev_flush_heavy); diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c index ac33c8f..aae2862 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c @@ -366,6 +366,21 @@ static int ipoib_mcast_sendonly_join(struct ipoib_mcast *mcast) return ret; } +void ipoib_mcast_carrier_on_task(struct work_struct *work) +{ + struct ipoib_dev_priv *priv = container_of(work, struct ipoib_dev_priv, + carrier_on_task); + + /* + * Take rtnl_lock to avoid racing with ipoib_stop() and + * turning the carrier back on while a device is being + * removed. + */ + rtnl_lock(); + netif_carrier_on(priv->dev); + rtnl_unlock(); +} + static int ipoib_mcast_join_complete(int status, struct ib_sa_multicast *multicast) { @@ -392,16 +407,12 @@ static int ipoib_mcast_join_complete(int status, &priv->mcast_task, 0); mutex_unlock(&mcast_mutex); - if (mcast == priv->broadcast) { - /* - * Take RTNL lock here to avoid racing with - * ipoib_stop() and turning the carrier back - * on while a device is being removed. - */ - rtnl_lock(); - netif_carrier_on(dev); - rtnl_unlock(); - } + /* + * Defer carrier on work to ipoib_workqueue to avoid a + * deadlock on rtnl_lock here. + */ + if (mcast == priv->broadcast) + queue_work(ipoib_workqueue, &priv->carrier_on_task); return 0; } |