From: Pedro M. López on
=================================
[ INFO: inconsistent lock state ]
2.6.34 #1
---------------------------------
inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage.
kswapd0/227 [HC0[0]:SC0[0]:HE1:SE1] takes:
(&(&ip->i_iolock)->mr_lock#2){++++?+}, at: [<ffffffff8112c11f>]
xfs_ilock+0x27/0x79 {RECLAIM_FS-ON-W} state was registered at:
[<ffffffff810510f5>] mark_held_locks+0x52/0x70
[<ffffffff81051198>] lockdep_trace_alloc+0x85/0x9f
[<ffffffff81073db2>] __alloc_pages_nodemask+0x7b/0x5b5
[<ffffffff8106f1e2>] grab_cache_page_write_begin+0x65/0xaa
[<ffffffff810bfaaa>] block_write_begin+0x38/0xcd
[<ffffffff81146f1f>] xfs_vm_write_begin+0x25/0x27
[<ffffffff8106e140>] generic_file_buffered_write+0x114/0x271
[<ffffffff8114aa31>] xfs_file_aio_write+0x4e1/0x70c
[<ffffffff8109d187>] do_sync_write+0xc6/0x103
[<ffffffff8109db5f>] vfs_write+0xad/0x172
[<ffffffff8109dcdd>] sys_write+0x45/0x6c
[<ffffffff81001f2b>] system_call_fastpath+0x16/0x1b
irq event stamp: 62175
hardirqs last enabled at (62175): [<ffffffff8126fb03>]
_raw_spin_unlock_irqrestore+0x3a/0x60 hardirqs last disabled at
(62174): [<ffffffff8126f3a9>] _raw_spin_lock_irqsave+0x17/0x58 softirqs
last enabled at (61572): [<ffffffff8103398d>] __do_softirq+0x127/0x13e
softirqs last disabled at (61543): [<ffffffff81002dcc>]
call_softirq+0x1c/0x28

other info that might help us debug this:
2 locks held by kswapd0/227:
#0: (shrinker_rwsem){++++..}, at: [<ffffffff810797f0>]
shrink_slab+0x38/0x144 #1: (&xfs_mount_list_lock){++++.-}, at:
[<ffffffff811503fc>] xfs_reclaim_inode_shrink+0x35/0x128

stack backtrace:
Pid: 227, comm: kswapd0 Not tainted 2.6.34 #1
Call Trace:
[<ffffffff81050b72>] print_usage_bug+0x1a4/0x1b5
[<ffffffff8100c995>] ? save_stack_trace+0x2a/0x47
[<ffffffff810516bc>] ? check_usage_forwards+0x0/0xcf
[<ffffffff81050e6d>] mark_lock+0x2ea/0x520
[<ffffffff81052b8a>] __lock_acquire+0x6c1/0x1607
[<ffffffff8116820b>] ? radix_tree_delete+0xd1/0x1d0
[<ffffffff81053b27>] lock_acquire+0x57/0x6d
[<ffffffff8112c11f>] ? xfs_ilock+0x27/0x79
[<ffffffff81046939>] down_write_nested+0x2a/0x4d
[<ffffffff8112c11f>] ? xfs_ilock+0x27/0x79
[<ffffffff8112c11f>] xfs_ilock+0x27/0x79
[<ffffffff8112c2eb>] xfs_ireclaim+0x93/0xb1
[<ffffffff8114f949>] xfs_reclaim_inode+0x1de/0x20a
[<ffffffff81150299>] xfs_inode_ag_walk+0x8b/0xe6
[<ffffffff8114f76b>] ? xfs_reclaim_inode+0x0/0x20a
[<ffffffff81150374>] xfs_inode_ag_iterator+0x80/0xd3
[<ffffffff8114f76b>] ? xfs_reclaim_inode+0x0/0x20a
[<ffffffff81150428>] xfs_reclaim_inode_shrink+0x61/0x128
[<ffffffff8107988b>] shrink_slab+0xd3/0x144
[<ffffffff81079c61>] balance_pgdat+0x365/0x59b
[<ffffffff81077908>] ? isolate_pages_global+0x0/0x212
[<ffffffff8107a089>] kswapd+0x1f2/0x20f
[<ffffffff81042e89>] ? autoremove_wake_function+0x0/0x34
[<ffffffff8126fb24>] ? _raw_spin_unlock_irqrestore+0x5b/0x60
[<ffffffff81079e97>] ? kswapd+0x0/0x20f
[<ffffffff81042ac7>] kthread+0x7a/0x82
[<ffffffff81002cd4>] kernel_thread_helper+0x4/0x10
[<ffffffff8126ff40>] ? restore_args+0x0/0x30
[<ffffffff81042a4d>] ? kthread+0x0/0x82
[<ffffffff81002cd0>] ? kernel_thread_helper+0x0/0x10