[SCSI] ibmvscsi: prevent scsi commands being sent in invalid state

There is a window where we can be re-enabling an adapter, but
still allow SCSI commands to be sent to the target.  This fix
sets our window (request_limit) to -1 as soon as we know the
adapter is being reenabled, and closes a very teeny tiny
window where we could set the window back to 1 before we
grab a lock.

Signed-off-by: Dave Boutcher <sleddog@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
index eaefedd..a279d0a 100644 (file)
--- a/drivers/scsi/ibmvscsi/ibmvscsi.c
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -853,14 +853,15 @@ static int send_srp_login(struct ibmvscsi_host_data *hostdata)
        login->max_requested_initiator_to_target_iulen = sizeof(union srp_iu);
        login->required_buffer_formats = 0x0006;
        
+       spin_lock_irqsave(hostdata->host->host_lock, flags);
        /* Start out with a request limit of 1, since this is negotiated in
         * the login request we are just sending
         */
        atomic_set(&hostdata->request_limit, 1);
 
-       spin_lock_irqsave(hostdata->host->host_lock, flags);
        rc = ibmvscsi_send_srp_event(evt_struct, hostdata);
        spin_unlock_irqrestore(hostdata->host->host_lock, flags);
+       printk("ibmvscsic: sent SRP login\n");
        return rc;
 };
 
@@ -1179,6 +1180,7 @@ void ibmvscsi_handle_crq(struct viosrp_crq *crq,
                        /* We need to re-setup the interpartition connection */
                        printk(KERN_INFO
                               "ibmvscsi: Re-enabling adapter!\n");
+                       atomic_set(&hostdata->request_limit, -1);
                        purge_requests(hostdata, DID_REQUEUE);
                        if (ibmvscsi_reenable_crq_queue(&hostdata->queue,
                                                        hostdata) == 0)