2010-04-15 21:02:26

by Alexander Beregalov

Subject: reiserfs locking

Hi Frederic!

[ INFO: possible circular locking dependency detected ]
2.6.34-rc3-00410-gd620a7c #1
-------------------------------------------------------
conftest/3639 is trying to acquire lock:
(&sb->s_type->i_mutex_key#5){+.+.+.}, at: [<c10f08fc>]
reiserfs_file_release+0x4c/0x3c0

but task is already holding lock:
(&mm->mmap_sem){++++++}, at: [<c10818e2>] sys_munmap+0x22/0x50

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&mm->mmap_sem){++++++}:
[<c104fcb3>] validate_chain+0xa23/0xf70
[<c10506d0>] __lock_acquire+0x4d0/0xa40
[<c1050cba>] lock_acquire+0x7a/0xa0
[<c107b90b>] might_fault+0x7b/0xa0
[<c11d6866>] copy_to_user+0x36/0x130
[<c10a05fc>] filldir+0x6c/0xd0
[<c10f14d1>] reiserfs_readdir_dentry+0x331/0x720
[<c10f18d7>] reiserfs_readdir+0x17/0x20
[<c10a07c5>] vfs_readdir+0x85/0xa0
[<c10a08f8>] sys_getdents+0x68/0xc0
[<c1002a90>] sysenter_do_call+0x12/0x36

-> #0 (&sb->s_type->i_mutex_key#5){+.+.+.}:
[<c10501f8>] validate_chain+0xf68/0xf70
[<c10506d0>] __lock_acquire+0x4d0/0xa40
[<c1050cba>] lock_acquire+0x7a/0xa0
[<c135765f>] mutex_lock_nested+0x5f/0x2b0
[<c10f08fc>] reiserfs_file_release+0x4c/0x3c0
[<c1094136>] __fput+0xf6/0x230
[<c1094285>] fput+0x15/0x20
[<c108092e>] remove_vma+0x3e/0x70
[<c10817f8>] do_munmap+0x228/0x2f0
[<c10818ef>] sys_munmap+0x2f/0x50
[<c1002a90>] sysenter_do_call+0x12/0x36

other info that might help us debug this:

1 lock held by conftest/3639:
#0: (&mm->mmap_sem){++++++}, at: [<c10818e2>] sys_munmap+0x22/0x50

stack backtrace:
Pid: 3639, comm: conftest Not tainted 2.6.34-rc3-00410-gd620a7c #1
Call Trace:
[<c1356147>] ? printk+0x18/0x21
[<c104ed20>] print_circular_bug+0xc0/0xd0
[<c10501f8>] validate_chain+0xf68/0xf70
[<c10425a5>] ? sched_clock_cpu+0x95/0x110
[<c104ca6b>] ? trace_hardirqs_off+0xb/0x10
[<c10506d0>] __lock_acquire+0x4d0/0xa40
[<c1050cba>] lock_acquire+0x7a/0xa0
[<c10f08fc>] ? reiserfs_file_release+0x4c/0x3c0
[<c135765f>] mutex_lock_nested+0x5f/0x2b0
[<c10f08fc>] ? reiserfs_file_release+0x4c/0x3c0
[<c10f08fc>] ? reiserfs_file_release+0x4c/0x3c0
[<c10f08fc>] reiserfs_file_release+0x4c/0x3c0
[<c1080d0e>] ? unlink_file_vma+0x3e/0x50
[<c135923d>] ? _raw_spin_unlock+0x1d/0x20
[<c1094136>] __fput+0xf6/0x230
[<c1094285>] fput+0x15/0x20
[<c108092e>] remove_vma+0x3e/0x70
[<c10817f8>] do_munmap+0x228/0x2f0
[<c10818ef>] sys_munmap+0x2f/0x50
[<c1002a90>] sysenter_do_call+0x12/0x36

2010-04-15 21:18:32

by Frederic Weisbecker

Subject: Re: reiserfs locking

On Fri, Apr 16, 2010 at 01:02:22AM +0400, Alexander Beregalov wrote:
> Hi Frederic!
>
> [ INFO: possible circular locking dependency detected ]
> 2.6.34-rc3-00410-gd620a7c #1


Thanks!

I'm going to look at this.