lar locking dependency detected ]
2.6.33.1linux-stable-2.6.33 #1
-------------------------------------------------------
fcoemon/18823 is trying to acquire lock:
(fcoe_config_mutex){+.+.+.}, at: [<ffffffffa02ba5fc>] fcoe_create+0x27/0x4f7
[fcoe]

but task is already holding lock:
(s_active){++++.+}, at: [<ffffffff8115ef93>] sysfs_get_active_two+0x31/0x48

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (s_active){++++.+}:
   [<ffffffff81077bdb>] __lock_acquire+0xb73/0xd2b
   [<ffffffff81077e60>] lock_acquire+0xcd/0xf1
   [<ffffffff8115e5df>] sysfs_deactivate+0x8b/0xe0
   [<ffffffff8115edfb>] sysfs_addrm_finish+0x36/0x55
   [<ffffffff8115d0cc>] sysfs_hash_and_remove+0x53/0x6a
   [<ffffffff8115f353>] sysfs_remove_link+0x21/0x23
   [<ffffffff812b6c93>] device_rename+0x99/0xcb
   [<ffffffff8138dbf0>] dev_change_name+0xd5/0x1d2
   [<ffffffff8138deee>] dev_ifsioc+0x201/0x2ac
   [<ffffffff8138e4ba>] dev_ioctl+0x521/0x632
   [<ffffffff81379e43>] sock_do_ioctl+0x3d/0x47
   [<ffffffff8137a254>] sock_ioctl+0x213/0x222
   [<ffffffff81114614>] vfs_ioctl+0x32/0xa6
   [<ffffffff81114b94>] do_vfs_ioctl+0x490/0x4d6
   [<ffffffff81114c30>] sys_ioctl+0x56/0x79
   [<ffffffff81009b42>] system_call_fastpath+0x16/0x1b

-> #1 (rtnl_mutex){+.+.+.}:
   [<ffffffff81077bdb>] __lock_acquire+0xb73/0xd2b
   [<ffffffff81077e60>] lock_acquire+0xcd/0xf1
   [<ffffffff8142f343>] __mutex_lock_common+0x4b/0x383
   [<ffffffff8142f73f>] mutex_lock_nested+0x3e/0x43
   [<ffffffff813959f9>] rtnl_lock+0x17/0x19
   [<ffffffff8138ccae>] register_netdevice_notifier+0x1e/0x19b
   [<ffffffffa02580c1>] 0xffffffffa02580c1
   [<ffffffff81002069>] do_one_initcall+0x5e/0x15e
   [<ffffffff81084094>] sys_init_module+0xd8/0x23a
   [<ffffffff81009b42>] system_call_fastpath+0x16/0x1b

-> #0 (fcoe_config_mutex){+.+.+.}:
   [<ffffffff81077a85>] __lock_acquire+0xa1d/0xd2b
   [<ffffffff81077e60>] lock_acquire+0xcd/0xf1
   [<ffffffff8142f343>] __mutex_lock_common+0x4b/0x383
   [<ffffffff8142f73f>] mutex_lock_nested+0x3e/0x43
   [<ffffffffa02ba5fc>] fcoe_create+0x27/0x4f7 [fcoe]
   [<ffffffff810635b1>] param_attr_store+0x27/0x35
   [<ffffffff81063619>] module_attr_store+0x26/0x2a
   [<ffffffff8115dae3>] sysfs_write_file+0x108/0x144
   [<ffffffff81107bd1>] vfs_write+0xae/0x10b
   [<ffffffff81107cee>] sys_write+0x4a/0x6e
   [<ffffffff81009b42>] system_call_fastpath+0x16/0x1b

other info that might help us debug this:

3 locks held by fcoemon/18823:
#0:  (&buffer->mutex){+.+.+.}, at: [<ffffffff8115da17>]
sysfs_write_file+0x3c/0x144
#1:  (s_active){++++.+}, at: [<ffffffff8115ef86>]
sysfs_get_active_two+0x24/0x48
#2:  (s_active){++++.+}, at: [<ffffffff8115ef93>]
sysfs_get_active_two+0x31/0x48

stack backtrace:
Pid: 18823, comm: fcoemon Tainted: G        W  2.6.33.1linux-stable-2.6.33 #1
Call Trace:
[<ffffffff81076c38>] print_circular_bug+0xa8/0xb6
[<ffffffff81077a85>] __lock_acquire+0xa1d/0xd2b
[<ffffffffa02ba5fc>] ? fcoe_create+0x27/0x4f7 [fcoe]
[<ffffffff81077e60>] lock_acquire+0xcd/0xf1
[<ffffffffa02ba5fc>] ? fcoe_create+0x27/0x4f7 [fcoe]
[<ffffffffa02ba5fc>] ? fcoe_create+0x27/0x4f7 [fcoe]
[<ffffffff8142f343>] __mutex_lock_common+0x4b/0x383
[<ffffffffa02ba5fc>] ? fcoe_create+0x27/0x4f7 [fcoe]
[<ffffffff8106ac70>] ? cpu_clock+0x43/0x5e
[<ffffffff81074e12>] ? lockstat_clock+0x11/0x13
[<ffffffff81074e40>] ? lock_release_holdtime+0x2c/0x127
[<ffffffff8115ef93>] ? sysfs_get_active_two+0x31/0x48
[<ffffffff8142f73f>] mutex_lock_nested+0x3e/0x43
[<ffffffffa02ba5fc>] fcoe_create+0x27/0x4f7 [fcoe]
[<ffffffff810635b1>] param_attr_store+0x27/0x35
[<ffffffff81063619>] module_attr_store+0x26/0x2a
[<ffffffff8115dae3>] sysfs_write_file+0x108/0x144
[<ffffffff81107bd1>] vfs_write+0xae/0x10b
[<ffffffff81076596>] ? trace_hardirqs_on_caller+0x125/0x150
[<ffffffff81107cee>] sys_write+0x4a/0x6e
[<ffffffff81009b42>] system_call_fastpath+0x16/0x1b

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
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