Re: [PATCH] csiostor: Fix backwards locking in the function __csio_unreg_rnode

[Julian Calaby]

Hi Bastien,

On Wed, Apr 6, 2016 at 7:19 AM, Bastien Philbert
<bastienphilbert@xxxxxxxxx> wrote:
> This fixes backwards locking in the function __csio_unreg_rnode to
> properly lock before the call to the function csio_unreg_rnode and
> not unlock with spin_unlock_irq as this would not allow the proper
> protection for concurrent access on the shared csio_hw structure
> pointer hw. In addition switch the locking after the critical region
> function call to properly unlock instead with spin_unlock_irq on
>
> Signed-off-by: Bastien Philbert <bastienphilbert@xxxxxxxxx>
> ---
>  drivers/scsi/csiostor/csio_rnode.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/csiostor/csio_rnode.c b/drivers/scsi/csiostor/csio_rnode.c
> index e9c3b04..029a09e 100644
> --- a/drivers/scsi/csiostor/csio_rnode.c
> +++ b/drivers/scsi/csiostor/csio_rnode.c
> @@ -580,9 +580,9 @@ __csio_unreg_rnode(struct csio_rnode *rn)
>                 ln->last_scan_ntgts--;
>         }
>
> -       spin_unlock_irq(&hw->lock);
> -       csio_unreg_rnode(rn);
>         spin_lock_irq(&hw->lock);
> +       csio_unreg_rnode(rn);
> +       spin_unlock_irq(&hw->lock);

Are you _certain_ this is correct? This construct usually appears when
a function has a particular lock held, then needs to unlock it to call
some other function. Are you _certain_ that this isn't the case?

Thanks,

-- 
Julian Calaby

Email: julian.calaby@xxxxxxxxx
Profile: http://www.google.com/profiles/julian.calaby/