Re: MPTSAS problems in 2.6.26-rc2-mm1

[Peter Zijlstra <a.p.zijlstra@chello.nl>]

On Wed, 2008-05-28 at 15:11 +0530, Balbir Singh wrote:
> I have 2.6.26-rc2-mm1 with Rik's splitvm patches. While booting the kernel, I
> ran into the following. I searched my email quickly to see that no one else has
> reported this problem. Lockdep seems to be complaining about the same lock being
> held at the same location (the message is a bit confusing to me).

looks like device_add() recursing - most likely with a different device
though.

> =============================================
> [ INFO: possible recursive locking detected ]
> 2.6.26-rc2-mm1 #2
> ---------------------------------------------
> insmod/1072 is trying to acquire lock:
>  (&cls->mutex){--..}, at: [<ffffffff803eb2cc>] device_add+0x46e/0x5d7
> 
> but task is already holding lock:
>  (&cls->mutex){--..}, at: [<ffffffff803eb2cc>] device_add+0x46e/0x5d7
> 
> other info that might help us debug this:
> 3 locks held by insmod/1072:
>  #0:  (&ioc->sas_discovery_mutex){--..}, at: [<ffffffffa003e7e9>]
> mptsas_probe+0x3a1/0x442 [mptsas]
>  #1:  (&shost->scan_mutex){--..}, at: [<ffffffff80466cbd>]
> scsi_scan_target+0x71/0xb0
>  #2:  (&cls->mutex){--..}, at: [<ffffffff803eb2cc>] device_add+0x46e/0x5d7
> 
> stack backtrace:
> Pid: 1072, comm: insmod Not tainted 2.6.26-rc2-mm1 #2
> 
> Call Trace:
>  [<ffffffff80254545>] __lock_acquire+0x911/0xc4c
>  [<ffffffff80254835>] ? __lock_acquire+0xc01/0xc4c
>  [<ffffffff803eb2cc>] ? device_add+0x46e/0x5d7
>  [<ffffffff8025490e>] lock_acquire+0x8e/0xb2
>  [<ffffffff803eb2cc>] ? device_add+0x46e/0x5d7
>  [<ffffffff8059e067>] mutex_lock_nested+0xf2/0x27f
>  [<ffffffff803eb2cc>] ? device_add+0x46e/0x5d7
>  [<ffffffff8059f80b>] ? _spin_unlock+0x26/0x2a
>  [<ffffffff803eb2cc>] device_add+0x46e/0x5d7
>  [<ffffffff803eb44e>] device_register+0x19/0x1d
>  [<ffffffff803eb531>] device_create+0xdf/0x110
>  [<ffffffff80253794>] ? trace_hardirqs_on_caller+0xf9/0x124
>  [<ffffffff802537cc>] ? trace_hardirqs_on+0xd/0xf
>  [<ffffffff8059df73>] ? mutex_unlock+0x9/0xb
>  [<ffffffff803eed13>] ? kobj_map+0x119/0x12e
>  [<ffffffff802a4488>] ? exact_lock+0x0/0x14
>  [<ffffffff802a4364>] ? exact_match+0x0/0x9
>  [<ffffffff80488bb4>] sg_add+0x262/0x394
>  [<ffffffff8059f80b>] ? _spin_unlock+0x26/0x2a
>  [<ffffffff803eb31b>] device_add+0x4bd/0x5d7
>  [<ffffffff80467d9b>] scsi_sysfs_add_sdev+0xde/0x200
>  [<ffffffff80465feb>] scsi_probe_and_add_lun+0x847/0x977
>  [<ffffffff8046639d>] __scsi_scan_target+0xbf/0x522
>  [<ffffffff80253794>] ? trace_hardirqs_on_caller+0xf9/0x124
>  [<ffffffff80250b9d>] ? debug_mutex_free_waiter+0x46/0x4a
>  [<ffffffff8059e1e5>] ? mutex_lock_nested+0x270/0x27f
>  [<ffffffff80466cbd>] ? scsi_scan_target+0x71/0xb0
>  [<ffffffff80466ce8>] scsi_scan_target+0x9c/0xb0
>  [<ffffffffa001ad60>] :scsi_transport_sas:sas_rphy_add+0x14c/0x15b
>  [<ffffffffa003cc17>] :mptsas:mptsas_probe_one_phy+0x364/0x3a9
>  [<ffffffffa003d651>] :mptsas:mptsas_probe_hba_phys+0x5bb/0x614
>  [<ffffffffa0028aeb>] ? :mptbase:mpt_timer_expired+0x0/0x2e
>  [<ffffffffa0028aeb>] ? :mptbase:mpt_timer_expired+0x0/0x2e
>  [<ffffffffa0028aeb>] ? :mptbase:mpt_timer_expired+0x0/0x2e
>  [<ffffffffa003e7f1>] :mptsas:mptsas_probe+0x3a9/0x442
>  [<ffffffff8039126a>] pci_device_probe+0xbd/0x116
>  [<ffffffff803ed1f0>] driver_probe_device+0xdb/0x162
>  [<ffffffff803ed2c6>] __driver_attach+0x4f/0x79
>  [<ffffffff803ed277>] ? __driver_attach+0x0/0x79
>  [<ffffffff803ec832>] bus_for_each_dev+0x4d/0x7e
>  [<ffffffff803ed01c>] driver_attach+0x1c/0x1e
>  [<ffffffff803eccc0>] bus_add_driver+0xba/0x212
>  [<ffffffff803ed4a6>] driver_register+0x93/0x10a
>  [<ffffffff80391526>] __pci_register_driver+0x73/0xad
>  [<ffffffffa00450e2>] :mptsas:mptsas_init+0xe2/0xfa
>  [<ffffffff8025c25e>] sys_init_module+0x9e/0x1b2
>  [<ffffffff8020b20b>] system_call_after_swapgs+0x7b/0x80
> 
> 
>