[BUG] 2.6.24-rc2-mm1 - kernel bug on nfs v4

[Torsten Kaiser]

On Nov 17, 2007 7:58 PM, Trond Myklebust <trond.myklebust at fys.uio.no> wrote:
>
> On Sat, 2007-11-17 at 18:53 +0100, Torsten Kaiser wrote:
> > On Nov 16, 2007 3:15 PM, Kamalesh Babulal <kamalesh at linux.vnet.ibm.com> wrote:
> > > Hi Andrew,
> > >
> > > The kernel enters the xmon state while running the file system
> > > stress on nfs v4 mounted partition.
> > [snip]
> > > 0:mon> t
> > > [c0000000dbd4fb50] c000000000069768 .__wake_up+0x54/0x88
> > > [c0000000dbd4fc00] d00000000086b890 .nfs_sb_deactive+0x44/0x58 [nfs]
> > > [c0000000dbd4fc80] d000000000872658 .nfs_free_unlinkdata+0x2c/0x74 [nfs]
> > > [c0000000dbd4fd10] d000000000598510 .rpc_release_calldata+0x50/0x74 [sunrpc]
> > > [c0000000dbd4fda0] c00000000008d960 .run_workqueue+0x10c/0x1f4
> > > [c0000000dbd4fe50] c00000000008ec70 .worker_thread+0x118/0x138
> > > [c0000000dbd4ff00] c0000000000939f4 .kthread+0x78/0xc4
> > > [c0000000dbd4ff90] c00000000002b060 .kernel_thread+0x4c/0x68
>
> Could you try with the attached patch.
[snip]
> Fix is to move the call to nfs_sb_deactive() into
> nfs_async_unlink_release().

I realley doubt that will fix it.

My stacktrace was like:
run_workqueue
called: rpc_async_schedule
  that called: rpc_release_calldata
    which points to: nfs_async_unlink_release
       that called: nfs_free_unlinkdata

So it does not matter for me if nfs_sb_deactive is called one step earlier.

Currently building with SLAB instead SLUB to see if lockdep tells something...

Torsten