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authorHaggai Eran <haggaie@mellanox.com>2015-07-07 17:45:13 +0300
committerDoug Ledford <dledford@redhat.com>2015-07-14 13:20:12 -0400
commit8b7cce0dae956b329d09099f8739821936cf7c0f (patch)
tree255b75ae43adcb94c269eebc76d70bc9ab6bc556
parent31b57b87fddf547bf3e98306b41bc82e111396fa (diff)
downloadlinux-8b7cce0dae956b329d09099f8739821936cf7c0f.tar.bz2
IB/ipoib: Prevent lockdep warning in __ipoib_ib_dev_flush
__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 <haggaie@mellanox.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
-rw-r--r--drivers/infiniband/ulp/ipoib/ipoib_ib.c13
1 files 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)