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

From: Anish Bhatt
Date: Fri Sep 04 2015 - 18:44:37 EST



> -----Original Message-----
> From: Nicholas Krause [mailto:xerofoify@xxxxxxxxx]
> Sent: Thursday, September 3, 2015 10:09 AM
> To: JBottomley@xxxxxxxx
> Cc: hare@xxxxxxx; michaelc@xxxxxxxxxxx; davem@xxxxxxxxxxxxx; Anish
> Bhatt; Hariprasad S; linux-scsi@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx
> Subject: [PATCH] csiostor:Fix backwards locking in the function
> __csio_unreg_rnode
>
> 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 the shared structure pointer.
>
> Signed-off-by: Nicholas Krause <xerofoify@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);
>
> /* Cleanup I/Os that were waiting for rnode to unregister */
> if (cmpl)
> --
> 2.1.4

NACK, function is called with lock held.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/