2013-03-22 03:09:15

by Yanchuan Nian

[permalink] [raw]
Subject: nfsv4.1 client refuses to suspend

nfsv4.1 client suspending fails with such info

Freezing of tasks failed after 20.00 seconds (1 tasks refusing to freeze, wq_busy=0):
nfsv4.1-svc S ffff88007889f2e0 0 3191 2 0x00000080
ffff88007b2f3e28 0000000000000046 ffff88007b2f2010 00000000000127c0
ffff880079b08000 00000000000127c0 ffff88007b2f3fd8 00000000000127c0
ffff88007b2f3fd8 00000000000127c0 ffffffff81a14410 ffff880079b08000
Call Trace:
[<ffffffff81441396>] schedule+0x64/0x66
[<ffffffffa06a6892>] nfs41_callback_svc+0x100/0x129 [nfsv4]
[<ffffffff8104fdb8>] ? wake_up_bit+0x2a/0x2a
[<ffffffffa06a6792>] ? nfs_callback_up+0x548/0x548 [nfsv4]
[<ffffffff8104f7e0>] kthread+0xb5/0xbd
[<ffffffff8104f72b>] ? kthread_freezable_should_stop+0x65/0x65
[<ffffffff8144912c>] ret_from_fork+0x7c/0xb0
[<ffffffff8104f72b>] ? kthread_freezable_should_stop+0x65/0x65

I read such threads
[1] nfs/sunrpc: allow freezing of tasks with NFS calls in flight
[2] LOCKDEP: 3.9-rc1: mount.nfs/4272 still has locks held!
and then modify nfs41_callback_svc(). It works on my machine. I don't know
the details of freezing, so I'm not sure if the modification is reasonable.
This is not a formal patch. Thanks.

Signed-off-by: Yanchuan Nian <[email protected]>
---
fs/nfs/callback.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index 5088b57..8addb7b 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -138,7 +138,7 @@ nfs41_callback_svc(void *vrqstp)
error);
} else {
spin_unlock_bh(&serv->sv_cb_lock);
- schedule();
+ freezable_schedule();
}
finish_wait(&serv->sv_cb_waitq, &wq);
}
--
1.7.4.4



2013-03-25 12:01:10

by Jeff Layton

[permalink] [raw]
Subject: Re: nfsv4.1 client refuses to suspend

On Mon, 25 Mar 2013 17:27:40 +0800
root <[email protected]> wrote:

> On Fri, Mar 22, 2013 at 07:40:03AM -0400, Jeff Layton wrote:
> > On Fri, 22 Mar 2013 10:57:21 +0800
> > [email protected] wrote:
> >
> > > nfsv4.1 client suspending fails with such info
> > >
> > > Freezing of tasks failed after 20.00 seconds (1 tasks refusing to freeze, wq_busy=0):
> > > nfsv4.1-svc S ffff88007889f2e0 0 3191 2 0x00000080
> > > ffff88007b2f3e28 0000000000000046 ffff88007b2f2010 00000000000127c0
> > > ffff880079b08000 00000000000127c0 ffff88007b2f3fd8 00000000000127c0
> > > ffff88007b2f3fd8 00000000000127c0 ffffffff81a14410 ffff880079b08000
> > > Call Trace:
> > > [<ffffffff81441396>] schedule+0x64/0x66
> > > [<ffffffffa06a6892>] nfs41_callback_svc+0x100/0x129 [nfsv4]
> > > [<ffffffff8104fdb8>] ? wake_up_bit+0x2a/0x2a
> > > [<ffffffffa06a6792>] ? nfs_callback_up+0x548/0x548 [nfsv4]
> > > [<ffffffff8104f7e0>] kthread+0xb5/0xbd
> > > [<ffffffff8104f72b>] ? kthread_freezable_should_stop+0x65/0x65
> > > [<ffffffff8144912c>] ret_from_fork+0x7c/0xb0
> > > [<ffffffff8104f72b>] ? kthread_freezable_should_stop+0x65/0x65
> > >
> > > I read such threads
> > > [1] nfs/sunrpc: allow freezing of tasks with NFS calls in flight
> > > [2] LOCKDEP: 3.9-rc1: mount.nfs/4272 still has locks held!
> > > and then modify nfs41_callback_svc(). It works on my machine. I don't know
> > > the details of freezing, so I'm not sure if the modification is reasonable.
> > > This is not a formal patch. Thanks.
> > >
> > > Signed-off-by: Yanchuan Nian <[email protected]>
> > > ---
> > > fs/nfs/callback.c | 2 +-
> > > 1 files changed, 1 insertions(+), 1 deletions(-)
> > >
> > > diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
> > > index 5088b57..8addb7b 100644
> > > --- a/fs/nfs/callback.c
> > > +++ b/fs/nfs/callback.c
> > > @@ -138,7 +138,7 @@ nfs41_callback_svc(void *vrqstp)
> > > error);
> > > } else {
> > > spin_unlock_bh(&serv->sv_cb_lock);
> > > - schedule();
> > > + freezable_schedule();
> > > }
> > > finish_wait(&serv->sv_cb_waitq, &wq);
> > > }
> >
> > I think it'd be better to have that thread call try_to_freeze()
> > directly instead of doing this. There are some problems with
> > freezable_schedule() that still need to be resolved and I suspect that
> > it will eventually go away entirely.
> >
> > It's may be sufficient to simply call try_to_freeze() at the top of
> > the loop, but that would need to be tested.
>
> Thanks, I tried it as follow
> echo 'mem' > /sys/power/state
> and it works ok. No further tests.
> >

I'm a little unclear on what patch you tested...

I just sent one that I think should fix this though. Would you be able
to test it and let me know if it helps?

Thanks,
--
Jeff Layton <[email protected]>

2013-03-25 09:38:58

by Yanchuan Nian

[permalink] [raw]
Subject: Re: nfsv4.1 client refuses to suspend

On Fri, Mar 22, 2013 at 07:40:03AM -0400, Jeff Layton wrote:
> On Fri, 22 Mar 2013 10:57:21 +0800
> [email protected] wrote:
>
> > nfsv4.1 client suspending fails with such info
> >
> > Freezing of tasks failed after 20.00 seconds (1 tasks refusing to freeze, wq_busy=0):
> > nfsv4.1-svc S ffff88007889f2e0 0 3191 2 0x00000080
> > ffff88007b2f3e28 0000000000000046 ffff88007b2f2010 00000000000127c0
> > ffff880079b08000 00000000000127c0 ffff88007b2f3fd8 00000000000127c0
> > ffff88007b2f3fd8 00000000000127c0 ffffffff81a14410 ffff880079b08000
> > Call Trace:
> > [<ffffffff81441396>] schedule+0x64/0x66
> > [<ffffffffa06a6892>] nfs41_callback_svc+0x100/0x129 [nfsv4]
> > [<ffffffff8104fdb8>] ? wake_up_bit+0x2a/0x2a
> > [<ffffffffa06a6792>] ? nfs_callback_up+0x548/0x548 [nfsv4]
> > [<ffffffff8104f7e0>] kthread+0xb5/0xbd
> > [<ffffffff8104f72b>] ? kthread_freezable_should_stop+0x65/0x65
> > [<ffffffff8144912c>] ret_from_fork+0x7c/0xb0
> > [<ffffffff8104f72b>] ? kthread_freezable_should_stop+0x65/0x65
> >
> > I read such threads
> > [1] nfs/sunrpc: allow freezing of tasks with NFS calls in flight
> > [2] LOCKDEP: 3.9-rc1: mount.nfs/4272 still has locks held!
> > and then modify nfs41_callback_svc(). It works on my machine. I don't know
> > the details of freezing, so I'm not sure if the modification is reasonable.
> > This is not a formal patch. Thanks.
> >
> > Signed-off-by: Yanchuan Nian <[email protected]>
> > ---
> > fs/nfs/callback.c | 2 +-
> > 1 files changed, 1 insertions(+), 1 deletions(-)
> >
> > diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
> > index 5088b57..8addb7b 100644
> > --- a/fs/nfs/callback.c
> > +++ b/fs/nfs/callback.c
> > @@ -138,7 +138,7 @@ nfs41_callback_svc(void *vrqstp)
> > error);
> > } else {
> > spin_unlock_bh(&serv->sv_cb_lock);
> > - schedule();
> > + freezable_schedule();
> > }
> > finish_wait(&serv->sv_cb_waitq, &wq);
> > }
>
> I think it'd be better to have that thread call try_to_freeze()
> directly instead of doing this. There are some problems with
> freezable_schedule() that still need to be resolved and I suspect that
> it will eventually go away entirely.
>
> It's may be sufficient to simply call try_to_freeze() at the top of
> the loop, but that would need to be tested.

Thanks, I tried it as follow
echo 'mem' > /sys/power/state
and it works ok. No further tests.
>
> --
> Jeff Layton <[email protected]>

2013-03-22 12:23:58

by Jeff Layton

[permalink] [raw]
Subject: Re: nfsv4.1 client refuses to suspend

On Fri, 22 Mar 2013 10:57:21 +0800
[email protected] wrote:

> nfsv4.1 client suspending fails with such info
>
> Freezing of tasks failed after 20.00 seconds (1 tasks refusing to freeze, wq_busy=0):
> nfsv4.1-svc S ffff88007889f2e0 0 3191 2 0x00000080
> ffff88007b2f3e28 0000000000000046 ffff88007b2f2010 00000000000127c0
> ffff880079b08000 00000000000127c0 ffff88007b2f3fd8 00000000000127c0
> ffff88007b2f3fd8 00000000000127c0 ffffffff81a14410 ffff880079b08000
> Call Trace:
> [<ffffffff81441396>] schedule+0x64/0x66
> [<ffffffffa06a6892>] nfs41_callback_svc+0x100/0x129 [nfsv4]
> [<ffffffff8104fdb8>] ? wake_up_bit+0x2a/0x2a
> [<ffffffffa06a6792>] ? nfs_callback_up+0x548/0x548 [nfsv4]
> [<ffffffff8104f7e0>] kthread+0xb5/0xbd
> [<ffffffff8104f72b>] ? kthread_freezable_should_stop+0x65/0x65
> [<ffffffff8144912c>] ret_from_fork+0x7c/0xb0
> [<ffffffff8104f72b>] ? kthread_freezable_should_stop+0x65/0x65
>
> I read such threads
> [1] nfs/sunrpc: allow freezing of tasks with NFS calls in flight
> [2] LOCKDEP: 3.9-rc1: mount.nfs/4272 still has locks held!
> and then modify nfs41_callback_svc(). It works on my machine. I don't know
> the details of freezing, so I'm not sure if the modification is reasonable.
> This is not a formal patch. Thanks.
>
> Signed-off-by: Yanchuan Nian <[email protected]>
> ---
> fs/nfs/callback.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
> index 5088b57..8addb7b 100644
> --- a/fs/nfs/callback.c
> +++ b/fs/nfs/callback.c
> @@ -138,7 +138,7 @@ nfs41_callback_svc(void *vrqstp)
> error);
> } else {
> spin_unlock_bh(&serv->sv_cb_lock);
> - schedule();
> + freezable_schedule();
> }
> finish_wait(&serv->sv_cb_waitq, &wq);
> }

I think it'd be better to have that thread call try_to_freeze()
directly instead of doing this. There are some problems with
freezable_schedule() that still need to be resolved and I suspect that
it will eventually go away entirely.

It's may be sufficient to simply call try_to_freeze() at the top of
the loop, but that would need to be tested.

--
Jeff Layton <[email protected]>