Re: Oops NFS Locking in 2.4.x

[Olivier Molteni <olivier@molteni.net>]

Trond Myklebust wrote:

>
> Looks like 2 processes are trying to free the same lock. The problem
> is that both processes can call filp_close() at the same
> time (by calling sys_close()).
>
> The bug boils down to:
>
>    -  locks_unlock_delete() assumes that the BKL (kernel_lock()) is
>       sufficient to protect against *thisfl_p from disappearing
>       beneath it due to some second process.
> BUT
>    -  The call to lock() in locks_unlock_delete() sleeps when the
>       underlying filesystem is NFS, hence 2 processes can race despite
>       the BKL assumption.
>
> Cheers,
>    Trond

Hi,
Thank for your help !!

I'm not a developper, but I would like to try to do something about
that...
Do you think that trying to replace the sleep by an other type of waiting
(at worst looping just to test the idea) could work ?

Cheers,
Olivier.