[prev in list] [next in list] [prev in thread] [next in thread] 

List:       linux-xfs
Subject:    Re: xfs_fsr: circular dependency under 2.6.24-rc6
From:       Lachlan McIlroy <lachlan () sgi ! com>
Date:       2008-01-14 0:18:59
Message-ID: 478AAA73.3080008 () sgi ! com
[Download RAW message or body]

Christopher,

This is a known dependency and is actually a false alarm.  The inode
that is being reclaimed (thread #2) cannot have writes in progress
(thread #0) since they cannot involve the same i_iolock.  We cannot
change the code to work around this nor can we add lockdep annotations
to avoid this case.  You can safely ignore this lockdep report.

Lachlan

Christopher Layne wrote:
> =======================================================
> [ INFO: possible circular locking dependency detected ]
> 2.6.24-rc6 #1
> -------------------------------------------------------
> xfs_fsr/5694 is trying to acquire lock:
>  (&mm->mmap_sem){----}, at: [<ffffffff802a9f8f>] dio_get_page+0x4b/0x184
> 
> but task is already holding lock:
>  (&(&ip->i_iolock)->mr_lock){----}, at: [<ffffffff802f4c5f>] xfs_ilock+0x4d/0x8d
> 
> which lock already depends on the new lock.
> 
> 
> the existing dependency chain (in reverse order) is:
> 
> -> #2 (&(&ip->i_iolock)->mr_lock){----}:
>        [<ffffffff80250f04>] __lock_acquire+0xb2b/0xd3f
>        [<ffffffff802f4c38>] xfs_ilock+0x26/0x8d
>        [<ffffffff8025119c>] lock_acquire+0x84/0xa8
>        [<ffffffff802f4c38>] xfs_ilock+0x26/0x8d
>        [<ffffffff8024fd51>] mark_held_locks+0x58/0x72
>        [<ffffffff802497c2>] down_write_nested+0x39/0x45
>        [<ffffffff802f4c38>] xfs_ilock+0x26/0x8d
>        [<ffffffff802f4e39>] xfs_ireclaim+0x37/0x7a
>        [<ffffffff8030ec2b>] xfs_finish_reclaim+0x15d/0x16b
>        [<ffffffff8031b671>] xfs_fs_clear_inode+0xca/0xeb
>        [<ffffffff80298535>] clear_inode+0x94/0xeb
>        [<ffffffff80298835>] dispose_list+0x58/0xfa
>        [<ffffffff80298bc4>] invalidate_inodes+0xd9/0xf7
>        [<ffffffff80288381>] generic_shutdown_super+0x39/0xf3
>        [<ffffffff80288448>] kill_block_super+0xd/0x1e
>        [<ffffffff802884f3>] deactivate_super+0x49/0x61
>        [<ffffffff8029addc>] sys_umount+0x1f5/0x206
>        [<ffffffff80477917>] trace_hardirqs_on_thunk+0x35/0x3a
>        [<ffffffff8024ff40>] trace_hardirqs_on+0x121/0x14c
>        [<ffffffff80477917>] trace_hardirqs_on_thunk+0x35/0x3a
>        [<ffffffff8020b6ce>] system_call+0x7e/0x83
>        [<ffffffffffffffff>] 0xffffffffffffffff
> 
> -> #1 (iprune_mutex){--..}:
>        [<ffffffff80250f04>] __lock_acquire+0xb2b/0xd3f
>        [<ffffffff80298919>] shrink_icache_memory+0x42/0x214
>        [<ffffffff8025119c>] lock_acquire+0x84/0xa8
>        [<ffffffff80298919>] shrink_icache_memory+0x42/0x214
>        [<ffffffff802510f7>] __lock_acquire+0xd1e/0xd3f
>        [<ffffffff80298919>] shrink_icache_memory+0x42/0x214
>        [<ffffffff80476bba>] mutex_lock_nested+0xfd/0x297
>        [<ffffffff80295968>] prune_dcache+0xd8/0x184
>        [<ffffffff80298919>] shrink_icache_memory+0x42/0x214
>        [<ffffffff802694ff>] shrink_slab+0xe7/0x15a
>        [<ffffffff8026a1eb>] try_to_free_pages+0x17a/0x24b
>        [<ffffffff80264c7b>] __alloc_pages+0x208/0x34e
>        [<ffffffff8026dcd0>] handle_mm_fault+0x211/0x66d
>        [<ffffffff80479eda>] do_page_fault+0x3bd/0x743
>        [<ffffffff80333ecb>] __up_write+0x21/0x112
>        [<ffffffff80333ecb>] __up_write+0x21/0x112
>        [<ffffffff80478124>] _spin_unlock_irqrestore+0x3e/0x44
>        [<ffffffff80477917>] trace_hardirqs_on_thunk+0x35/0x3a
>        [<ffffffff8024ff40>] trace_hardirqs_on+0x121/0x14c
>        [<ffffffff8047834d>] error_exit+0x0/0xa9
>        [<ffffffffffffffff>] 0xffffffffffffffff
> 
> -> #0 (&mm->mmap_sem){----}:
>        [<ffffffff80250e09>] __lock_acquire+0xa30/0xd3f
>        [<ffffffff802a9f8f>] dio_get_page+0x4b/0x184
>        [<ffffffff8025119c>] lock_acquire+0x84/0xa8
>        [<ffffffff802a9f8f>] dio_get_page+0x4b/0x184
>        [<ffffffff80476ed4>] down_read+0x32/0x3b
>        [<ffffffff802a9f8f>] dio_get_page+0x4b/0x184
>        [<ffffffff80338b47>] __spin_lock_init+0x29/0x47
>        [<ffffffff802aaa7c>] __blockdev_direct_IO+0x3fc/0x9c6
>        [<ffffffff8024e2f5>] lockdep_init_map+0x8f/0x460
>        [<ffffffff803143de>] xfs_vm_direct_IO+0x101/0x134
>        [<ffffffff803146ee>] xfs_get_blocks_direct+0x0/0x11
>        [<ffffffff80313e95>] xfs_end_io_direct+0x0/0x82
>        [<ffffffff80333ecb>] __up_write+0x21/0x112
>        [<ffffffff8026022f>] generic_file_direct_IO+0xcd/0x103
>        [<ffffffff802602c5>] generic_file_direct_write+0x60/0xfd
>        [<ffffffff8031b1f9>] xfs_write+0x4ed/0x760
>        [<ffffffff802f4bbf>] xfs_iunlock+0x37/0x85
>        [<ffffffff8031aced>] xfs_read+0x1f1/0x210
>        [<ffffffff8028637d>] do_sync_write+0xd1/0x118
>        [<ffffffff802510f7>] __lock_acquire+0xd1e/0xd3f
>        [<ffffffff80246df0>] autoremove_wake_function+0x0/0x2e
>        [<ffffffff802b7cc5>] dnotify_parent+0x1f/0x6d
>        [<ffffffff80286ace>] vfs_write+0xad/0x136
>        [<ffffffff80287005>] sys_write+0x45/0x6e
>        [<ffffffff8020b6ce>] system_call+0x7e/0x83
>        [<ffffffffffffffff>] 0xffffffffffffffff
> 
> other info that might help us debug this:
> 
> 1 lock held by xfs_fsr/5694:
>  #0:  (&(&ip->i_iolock)->mr_lock){----}, at: [<ffffffff802f4c5f>] xfs_ilock+0x4d/0x8d
> 
> stack backtrace:
> Pid: 5694, comm: xfs_fsr Not tainted 2.6.24-rc6 #1
> 
> Call Trace:
>  [<ffffffff8024f0b3>] print_circular_bug_tail+0x69/0x72
>  [<ffffffff80250e09>] __lock_acquire+0xa30/0xd3f
>  [<ffffffff802a9f8f>] dio_get_page+0x4b/0x184
>  [<ffffffff8025119c>] lock_acquire+0x84/0xa8
>  [<ffffffff802a9f8f>] dio_get_page+0x4b/0x184
>  [<ffffffff80476ed4>] down_read+0x32/0x3b
>  [<ffffffff802a9f8f>] dio_get_page+0x4b/0x184
>  [<ffffffff80338b47>] __spin_lock_init+0x29/0x47
>  [<ffffffff802aaa7c>] __blockdev_direct_IO+0x3fc/0x9c6
>  [<ffffffff8024e2f5>] lockdep_init_map+0x8f/0x460
>  [<ffffffff803143de>] xfs_vm_direct_IO+0x101/0x134
>  [<ffffffff803146ee>] xfs_get_blocks_direct+0x0/0x11
>  [<ffffffff80313e95>] xfs_end_io_direct+0x0/0x82
>  [<ffffffff80333ecb>] __up_write+0x21/0x112
>  [<ffffffff8026022f>] generic_file_direct_IO+0xcd/0x103
>  [<ffffffff802602c5>] generic_file_direct_write+0x60/0xfd
>  [<ffffffff8031b1f9>] xfs_write+0x4ed/0x760
>  [<ffffffff802f4bbf>] xfs_iunlock+0x37/0x85
>  [<ffffffff8031aced>] xfs_read+0x1f1/0x210
>  [<ffffffff8028637d>] do_sync_write+0xd1/0x118
>  [<ffffffff802510f7>] __lock_acquire+0xd1e/0xd3f
>  [<ffffffff80246df0>] autoremove_wake_function+0x0/0x2e
>  [<ffffffff802b7cc5>] dnotify_parent+0x1f/0x6d
>  [<ffffffff80286ace>] vfs_write+0xad/0x136
>  [<ffffffff80287005>] sys_write+0x45/0x6e
>  [<ffffffff8020b6ce>] system_call+0x7e/0x83
> 
> 
> --
> 
> xfs issue or kernel issue?
> 
> -cl
> 
> 
> 


[prev in list] [next in list] [prev in thread] [next in thread]