Re: [PATCH] bnx2fc:Add proper locking protection in bnx2fc_ctrlr_enabled

[Chad Dupuis <chad.dupuis@qlogic.com>]

On Sat, 12 Dec 2015, Nicholas Krause wrote:

> This adds proper locking protection in bnx2fc_ctrl_enabled around
> the calls to the functions, _bnx2fc_enable and _bnx2fc_disable in
> order to avoid concurrent access on these functions accessing global
> referenced data structures in their internal intended work.
>
> Signed-off-by: Nicholas Krause <xerofoify@gmail.com>
> ---
> drivers/scsi/bnx2fc/bnx2fc_fcoe.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c
> index 67405c6..e43648f 100644
> --- a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c
> +++ b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c
> @@ -2177,13 +2177,21 @@ static int bnx2fc_ctlr_enabled(struct fcoe_ctlr_device *cdev)
> {
> 	struct fcoe_ctlr *ctlr = fcoe_ctlr_device_priv(cdev);
>
> +	rtnl_lock();
> +	mutex_lock(&bnx2fc_dev_lock);
> 	switch (cdev->enabled) {
> 	case FCOE_CTLR_ENABLED:
> +		rtnl_unlock();
> +		mutex_unlock(&bnx2fc_dev_lock);
> 		return __bnx2fc_enable(ctlr);
> 	case FCOE_CTLR_DISABLED:
> +		rtnl_unlock();
> +		mutex_unlock(&bnx2fc_dev_lock);
> 		return __bnx2fc_disable(ctlr);
> 	case FCOE_CTLR_UNUSED:
> 	default:
> +		rtnl_unlock();
> +		mutex_unlock(&bnx2fc_dev_lock);
> 		return -ENOTSUPP;
> 	};
> }
>

Nack.  All we end up protecting is the check of cdev->enabled and I do not 
believe taking two mutexes is required for that.