Hi Or,

I saw below warning when enable CONFIG_DEBUG_MUTEXES


> 1893 May 21 08:56:32 ib2 kernel: [   44.738725] =============================================
>  1894 May 21 08:56:32 ib2 kernel: [   44.738782] [ INFO: possible recursive locking detected ]
>  1895 May 21 08:56:32 ib2 kernel: [   44.738841] 3.9.0-rc7-pserver #4 Tainted: G           O
>  1896 May 21 08:56:32 ib2 kernel: [   44.738896] ---------------------------------------------
>  1897 May 21 08:56:32 ib2 kernel: [   44.738953] kworker/u:5/238 is trying to acquire lock:
>  1898 May 21 08:56:32 ib2 kernel: [   44.739008]  (&priv->vlan_mutex){+.+.+.}, at: [<ffffffffa073f36c>] __ipoib_ib_dev_flush+0x3c/0x230 [ib_ipoib]
>  1899 May 21 08:56:32 ib2 kernel: [   44.739218]
>  1900 May 21 08:56:32 ib2 kernel: [   44.739218] but task is already holding lock:
>  1901 May 21 08:56:32 ib2 kernel: [   44.739328]  (&priv->vlan_mutex){+.+.+.}, at: [<ffffffffa073f36c>] __ipoib_ib_dev_flush+0x3c/0x230 [ib_ipoib]
>  1902 May 21 08:56:32 ib2 kernel: [   44.739537]
>  1903 May 21 08:56:32 ib2 kernel: [   44.739537] other info that might help us debug this:
>  1904 May 21 08:56:32 ib2 kernel: [   44.739613]  Possible unsafe locking scenario:
>  1905 May 21 08:56:32 ib2 kernel: [   44.739613]
>  1906 May 21 08:56:32 ib2 kernel: [   44.739688]        CPU0
>  1907 May 21 08:56:32 ib2 kernel: [   44.739741]        ----
>  1908 May 21 08:56:32 ib2 kernel: [   44.739791]   lock(&priv->vlan_mutex);
>  1909 May 21 08:56:32 ib2 kernel: [   44.739902]   lock(&priv->vlan_mutex);
>  1910 May 21 08:56:32 ib2 kernel: [   44.740014]
>  1911 May 21 08:56:32 ib2 kernel: [   44.740014]  *** DEADLOCK ***
>  1912 May 21 08:56:32 ib2 kernel: [   44.740014]
>  1913 May 21 08:56:32 ib2 kernel: [   44.740103]  May be due to missing lock nesting notation
>  1914 May 21 08:56:32 ib2 kernel: [   44.740103]
>  1915 May 21 08:56:32 ib2 kernel: [   44.740213] 3 locks held by kworker/u:5/238:
>  1916 May 21 08:56:32 ib2 kernel: [   44.740266]  #0:  (ipoib){.+.+.+}, at: [<ffffffff81067755>] process_one_work+0x165/0x560
>  1917 May 21 08:56:32 ib2 kernel: [   44.740495]  #1:  ((&priv->flush_heavy)){+.+...}, at: [<ffffffff81067755>] process_one_work+0x165/0x560
>  1918 May 21 08:56:32 ib2 kernel: [   44.740725]  #2:  (&priv->vlan_mutex){+.+.+.}, at: [<ffffffffa073f36c>] __ipoib_ib_dev_flush+0x3c/0x230 [ib_ipoib]
>  1919 May 21 08:56:32 ib2 kernel: [   44.740961]
>  1920 May 21 08:56:32 ib2 kernel: [   44.740961] stack backtrace:
>  1921 May 21 08:56:32 ib2 kernel: [   44.741035] Pid: 238, comm: kworker/u:5 Tainted: G           O 3.9.0-rc7-pserver #4
>  1922 May 21 08:56:32 ib2 kernel: [   44.741111] Call Trace:
>  1923 May 21 08:56:32 ib2 kernel: [   44.741170]  [<ffffffff81046430>] ? vprintk_emit+0x280/0x520
>  1924 May 21 08:56:32 ib2 kernel: [   44.741233]  [<ffffffff810ac473>] __lock_acquire+0x6c3/0x17c0
>  1925 May 21 08:56:32 ib2 kernel: [   44.741295]  [<ffffffff810aca3c>] ? __lock_acquire+0xc8c/0x17c0
>  1926 May 21 08:56:32 ib2 kernel: [   44.741357]  [<ffffffff810047a7>] ? dump_trace+0x177/0x2f0
>  1927 May 21 08:56:32 ib2 kernel: [   44.741418]  [<ffffffff810ad612>] lock_acquire+0xa2/0x180
>  1928 May 21 08:56:32 ib2 kernel: [   44.741483]  [<ffffffffa073f36c>] ? __ipoib_ib_dev_flush+0x3c/0x230 [ib_ipoib]
>  1929 May 21 08:56:32 ib2 kernel: [   44.741563]  [<ffffffff8101090f>] ? save_stack_trace+0x2f/0x50
>  1930 May 21 08:56:32 ib2 kernel: [   44.741626]  [<ffffffff817bb0cb>] __mutex_lock_common+0x5b/0x3e0
>  1931 May 21 08:56:32 ib2 kernel: [   44.741693]  [<ffffffffa073f36c>] ? __ipoib_ib_dev_flush+0x3c/0x230 [ib_ipoib]
>  1932 May 21 08:56:32 ib2 kernel: [   44.741777]  [<ffffffffa073f36c>] ? __ipoib_ib_dev_flush+0x3c/0x230 [ib_ipoib]
>  1933 May 21 08:56:32 ib2 kernel: [   44.741855]  [<ffffffff817bb585>] mutex_lock_nested+0x45/0x50
>  1934 May 21 08:56:32 ib2 kernel: [   44.741922]  [<ffffffffa073f36c>] __ipoib_ib_dev_flush+0x3c/0x230 [ib_ipoib]
>  1935 May 21 08:56:32 ib2 kernel: [   44.741991]  [<ffffffffa073f38a>] __ipoib_ib_dev_flush+0x5a/0x230 [ib_ipoib]
>  1936 May 21 08:56:32 ib2 kernel: [   44.742060]  [<ffffffffa073f57a>] ipoib_ib_dev_flush_heavy+0x1a/0x20 [ib_ipoib]
> 1937 May 21 08:56:32 ib2 kernel: [   44.742138]  [<ffffffff810677c6>] process_one_work+0x1d6/0x560
>  1938 May 21 08:56:32 ib2 kernel: [   44.742199]  [<ffffffff81067755>] ? process_one_work+0x165/0x560
>  1939 May 21 08:56:32 ib2 kernel: [   44.742262]  [<ffffffff81068e29>] worker_thread+0x119/0x370
>  1940 May 21 08:56:32 ib2 kernel: [   44.742324]  [<ffffffff81068d10>] ? manage_workers+0x340/0x340
>  1941 May 21 08:56:32 ib2 kernel: [   44.742388]  [<ffffffff8106e846>] kthread+0xe6/0xf0
>  1942 May 21 08:56:32 ib2 kernel: [   44.742450]  [<ffffffff8106e760>] ? __init_kthread_worker+0x70/0x70
>  1943 May 21 08:56:32 ib2 kernel: [   44.742513]  [<ffffffff817c842c>] ret_from_fork+0x7c/0xb0
>  1944 May 21 08:56:32 ib2 kernel: [   44.742575]  [<ffffffff8106e760>] ? __init_kthread_worker+0x70/0x70
>  1945 May 21 08:56:32 ib2 kernel: [   44.744467] IPv6: ADDRCONF(NETDEV_CHANGE): ib1: link becomes ready
>  1946 May 21 08:56:45 ib2 kernel: [   57.700823] IPv6: ADDRCONF(NETDEV_CHANGE): ib0: link becomes ready

And I found attached patch you submitted long time ago, I tried that
patch, it fixed the warning, I wonder why the patch was not accepted,
anything wrong?

Regards,
Jack