__ipoib_ib_dev_flush calls itself recursively on child devices, and lockdep
complains about locking vlan_rwsem twice (see below). Use down_read_nested
instead of down_read to prevent the warning.
=============================================
[ INFO: possible recursive locking detected ]
4.1.0-rc4+ #36 Tainted: G O
---------------------------------------------
kworker/u20:2/261 is trying to acquire lock:
(&priv->vlan_rwsem){.+.+..}, at: [<ffffffffa0791e2a>]
__ipoib_ib_dev_flush+0x3a/0x2b0 [ib_ipoib]
but task is already holding lock:
(&priv->vlan_rwsem){.+.+..}, at: [<ffffffffa0791e2a>]
__ipoib_ib_dev_flush+0x3a/0x2b0 [ib_ipoib]
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&priv->vlan_rwsem);
lock(&priv->vlan_rwsem);
*** DEADLOCK ***
May be due to missing lock nesting notation
3 locks held by kworker/u20:2/261:
#0: ("%s""ipoib_flush"){.+.+..}, at: [<ffffffff810827cc>]
process_one_work+0x15c/0x760
#1: ((&priv->flush_heavy)){+.+...}, at: [<ffffffff810827cc>]
process_one_work+0x15c/0x760
#2: (&priv->vlan_rwsem){.+.+..}, at: [<ffffffffa0791e2a>]
__ipoib_ib_dev_flush+0x3a/0x2b0 [ib_ipoib]
stack backtrace:
CPU: 3 PID: 261 Comm: kworker/u20:2 Tainted: G O 4.1.0-rc4+ #36
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2007
Workqueue: ipoib_flush ipoib_ib_dev_flush_heavy [ib_ipoib]
ffff8801c6c54790 ffff8801c9927af8 ffffffff81665238 0000000000000001
ffffffff825b5b30 ffff8801c9927bd8 ffffffff810bba51 ffff880100000000
ffffffff00000001 ffff880100000001 ffff8801c6c55428 ffff8801c6c54790
Call Trace:
[<ffffffff81665238>] dump_stack+0x4f/0x6f
[<ffffffff810bba51>] __lock_acquire+0x741/0x1820
[<ffffffff810bcbf8>] lock_acquire+0xc8/0x240
[<ffffffffa0791e2a>] ? __ipoib_ib_dev_flush+0x3a/0x2b0 [ib_ipoib]
[<ffffffff81669d2c>] down_read+0x4c/0x70
[<ffffffffa0791e2a>] ? __ipoib_ib_dev_flush+0x3a/0x2b0 [ib_ipoib]
[<ffffffffa0791e2a>] __ipoib_ib_dev_flush+0x3a/0x2b0 [ib_ipoib]
[<ffffffffa0791e4a>] __ipoib_ib_dev_flush+0x5a/0x2b0 [ib_ipoib]
[<ffffffffa07920ba>] ipoib_ib_dev_flush_heavy+0x1a/0x20 [ib_ipoib]
[<ffffffff81082871>] process_one_work+0x201/0x760
[<ffffffff810827cc>] ? process_one_work+0x15c/0x760
[<ffffffff81082ef0>] worker_thread+0x120/0x4d0
[<ffffffff81082dd0>] ? process_one_work+0x760/0x760
[<ffffffff81082dd0>] ? process_one_work+0x760/0x760
[<ffffffff81088b7e>] kthread+0xfe/0x120
[<ffffffff81088a80>] ? __init_kthread_worker+0x70/0x70
[<ffffffff8166c6e2>] ret_from_fork+0x42/0x70
[<ffffffff81088a80>] ? __init_kthread_worker+0x70/0x70
Signed-off-by: Haggai Eran <[email protected]>
---
drivers/infiniband/ulp/ipoib/ipoib_ib.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_ib.c
b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
index 63b92cbb29ad..058150ff5aa1 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_ib.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
@@ -985,20 +985,21 @@ static inline int update_child_pkey(struct ipoib_dev_priv
*priv)
}
static void __ipoib_ib_dev_flush(struct ipoib_dev_priv *priv,
- enum ipoib_flush_level level)
+ enum ipoib_flush_level level,
+ int nesting)
{
struct ipoib_dev_priv *cpriv;
struct net_device *dev = priv->dev;
int result;
- down_read(&priv->vlan_rwsem);
+ down_read_nested(&priv->vlan_rwsem, nesting);
/*
* Flush any child interfaces too -- they might be up even if
* the parent is down.
*/
list_for_each_entry(cpriv, &priv->child_intfs, list)
- __ipoib_ib_dev_flush(cpriv, level);
+ __ipoib_ib_dev_flush(cpriv, level, nesting + 1);
up_read(&priv->vlan_rwsem);
@@ -1076,7 +1077,7 @@ void ipoib_ib_dev_flush_light(struct work_struct *work)
struct ipoib_dev_priv *priv =
container_of(work, struct ipoib_dev_priv, flush_light);
- __ipoib_ib_dev_flush(priv, IPOIB_FLUSH_LIGHT);
+ __ipoib_ib_dev_flush(priv, IPOIB_FLUSH_LIGHT, 0);
}
void ipoib_ib_dev_flush_normal(struct work_struct *work)
@@ -1084,7 +1085,7 @@ void ipoib_ib_dev_flush_normal(struct work_struct *work)
struct ipoib_dev_priv *priv =
container_of(work, struct ipoib_dev_priv, flush_normal);
- __ipoib_ib_dev_flush(priv, IPOIB_FLUSH_NORMAL);
+ __ipoib_ib_dev_flush(priv, IPOIB_FLUSH_NORMAL, 0);
}
void ipoib_ib_dev_flush_heavy(struct work_struct *work)
@@ -1092,7 +1093,7 @@ void ipoib_ib_dev_flush_heavy(struct work_struct *work)
struct ipoib_dev_priv *priv =
container_of(work, struct ipoib_dev_priv, flush_heavy);
- __ipoib_ib_dev_flush(priv, IPOIB_FLUSH_HEAVY);
+ __ipoib_ib_dev_flush(priv, IPOIB_FLUSH_HEAVY, 0);
}
void ipoib_ib_dev_cleanup(struct net_device *dev)
--
1.7.11.2
--
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