2.6.18rc5: NFSd possible recursive locking

2.6.18rc5: NFSd possible recursive locking

[Krzysztof Halasa]

Hi,

another one (details available on request):

[ INFO: possible recursive locking detected ]
---------------------------------------------
nfsd/1566 is trying to acquire lock:
 (&inode->i_mutex){--..}, at: [<c0334e0c>] mutex_lock+0x1c/0x20

but task is already holding lock:
 (&inode->i_mutex){--..}, at: [<c0334e0c>] mutex_lock+0x1c/0x20

other info that might help us debug this:
2 locks held by nfsd/1566:
 #0:  (hash_sem){..--}, at: [<c01b292d>] exp_readlock+0xd/0x10
 #1:  (&inode->i_mutex){--..}, at: [<c0334e0c>] mutex_lock+0x1c/0x20

stack backtrace:
 [<c0103522>] show_trace+0x12/0x20
 [<c0103b79>] dump_stack+0x19/0x20
 [<c012dfab>] __lock_acquire+0x8db/0xd70
 [<c012e7b6>] lock_acquire+0x76/0xa0
 [<c0334c06>] __mutex_lock_slowpath+0x66/0x250
 [<c0334e0c>] mutex_lock+0x1c/0x20
 [<c01afd1d>] nfsd_setattr+0x46d/0x5b0
 [<c01b12da>] nfsd_create_v3+0x4da/0x540
 [<c01b6574>] nfsd3_proc_create+0x104/0x170
 [<c01ab7d8>] nfsd_dispatch+0x88/0x1e0
 [<c03248d4>] svc_process+0x3f4/0x6e0
 [<c01abce1>] nfsd+0x191/0x300
 [<c0100c85>] kernel_thread_helper+0x5/0x10
-- 
Krzysztof Halasa

-- 
VGER BF report: U 0.502044

Re: 2.6.18rc5: NFSd possible recursive locking

[Dave Jones]

On Sun, Sep 03, 2006 at 10:26:35PM +0200, Krzysztof Halasa wrote:
 > Hi,
 > 
 > another one (details available on request):
 > 
 > [ INFO: possible recursive locking detected ]
 > ---------------------------------------------
 > nfsd/1566 is trying to acquire lock:
 >  (&inode->i_mutex){--..}, at: [<c0334e0c>] mutex_lock+0x1c/0x20
 > 
 > but task is already holding lock:
 >  (&inode->i_mutex){--..}, at: [<c0334e0c>] mutex_lock+0x1c/0x20

This one has been there for a month or so..
http://bugme.osdl.org/show_bug.cgi?id=6918

	Dave
 

Re: 2.6.18rc5: NFSd possible recursive locking

[Peter Zijlstra]

On Sun, 2006-09-03 at 22:26 +0200, Krzysztof Halasa wrote:
> Hi,
> 
> another one (details available on request):
> 
> [ INFO: possible recursive locking detected ]
> ---------------------------------------------
> nfsd/1566 is trying to acquire lock:
>  (&inode->i_mutex){--..}, at: [<c0334e0c>] mutex_lock+0x1c/0x20
> 
> but task is already holding lock:
>  (&inode->i_mutex){--..}, at: [<c0334e0c>] mutex_lock+0x1c/0x20
> 
> other info that might help us debug this:
> 2 locks held by nfsd/1566:
>  #0:  (hash_sem){..--}, at: [<c01b292d>] exp_readlock+0xd/0x10
>  #1:  (&inode->i_mutex){--..}, at: [<c0334e0c>] mutex_lock+0x1c/0x20
> 
> stack backtrace:
>  [<c0103522>] show_trace+0x12/0x20
>  [<c0103b79>] dump_stack+0x19/0x20
>  [<c012dfab>] __lock_acquire+0x8db/0xd70
>  [<c012e7b6>] lock_acquire+0x76/0xa0
>  [<c0334c06>] __mutex_lock_slowpath+0x66/0x250
>  [<c0334e0c>] mutex_lock+0x1c/0x20
>  [<c01afd1d>] nfsd_setattr+0x46d/0x5b0
>  [<c01b12da>] nfsd_create_v3+0x4da/0x540
>  [<c01b6574>] nfsd3_proc_create+0x104/0x170
>  [<c01ab7d8>] nfsd_dispatch+0x88/0x1e0
>  [<c03248d4>] svc_process+0x3f4/0x6e0
>  [<c01abce1>] nfsd+0x191/0x300
>  [<c0100c85>] kernel_thread_helper+0x5/0x10

http://kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.18-rc5/2.6.18-rc5-mm1/broken-out/nfsd-lockdep-annotation.patch
http://kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.18-rc5/2.6.18-rc5-mm1/broken-out/knfsd-nfsd-lockdep-annotation-fix.patch

Do those patches fix it?

Re: 2.6.18rc5: NFSd possible recursive locking

[Krzysztof Halasa]

Peter Zijlstra <a.p.zijlstra@chello.nl> writes:

> http://kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.18-rc5/2.6.18-rc5-mm1/broken-out/nfsd-lockdep-annotation.patch
> http://kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.18-rc5/2.6.18-rc5-mm1/broken-out/knfsd-nfsd-lockdep-annotation-fix.patch
>
> Do those patches fix it?

I think so. And NFS server still works :-)
-- 
Krzysztof Halasa