[2.6.21.4]: possible recursive locking detected

[Tomasz Kłoczko <kloczek@rudy.mif.pg.gda.pl>]

I found below call trace today morning in dmesg output on one of my test
computer:

=============================================
[ INFO: possible recursive locking detected ]
2.6.21.4-2.1 #1
---------------------------------------------
usb-storage/1806 is trying to acquire lock:
 (&(us->dev_mutex)){--..}, at: [<c05f28a2>] mutex_lock+0x1c/0x1f

but task is already holding lock:
 (&(us->dev_mutex)){--..}, at: [<c05f28a2>] mutex_lock+0x1c/0x1f

other info that might help us debug this:
1 lock held by usb-storage/1806:
 #0:  (&(us->dev_mutex)){--..}, at: [<c05f28a2>] mutex_lock+0x1c/0x1f

stack backtrace:
 [<c04064d4>] show_trace_log_lvl+0x1a/0x2f
 [<c0406a7f>] show_trace+0x12/0x14
 [<c0406afa>] dump_stack+0x16/0x18
 [<c043fb88>] __lock_acquire+0x116/0xb4b
 [<c044097e>] lock_acquire+0x56/0x6f
 [<c05f2721>] __mutex_lock_slowpath+0xe5/0x24a
 [<c05f28a2>] mutex_lock+0x1c/0x1f
 [<f89981d3>] storage_pre_reset+0xe/0x10 [usb_storage]
 [<c0552e3d>] usb_reset_composite_device+0x9c/0x124
 [<f8996888>] usb_stor_port_reset+0x34/0x57 [usb_storage]
 [<f899778e>] usb_stor_invoke_transport+0x255/0x293 [usb_storage]
 [<f89967b9>] usb_stor_transparent_scsi_command+0x8/0xa [usb_storage]
 [<f899833e>] usb_stor_control_thread+0x136/0x1b7 [usb_storage]
 [<c0435edf>] kthread+0xb3/0xdc
 [<c0406177>] kernel_thread_helper+0x7/0x10
 =======================
usb 1-1.2: reset high speed USB device using ehci_hcd and address 5

kloczek
--
-----------------------------------------------------------
*Ludzie nie mają problemów, tylko sobie sami je stwarzają*
-----------------------------------------------------------
Tomasz Kłoczko, sys adm @zie.pg.gda.pl|*e-mail: kloczek@rudy.mif.pg.gda.pl*