[SCSI] ibmvscsi: treat busy and error conditions separately

This patch fixes a condition where ibmvscsi treats a transport error as a
"busy" condition, so no errors were returned to the scsi mid-layer.
In a RAID environment this means that I/O hung rather than failing
over.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
index 944fc12..669ea4f 100644 (file)
--- a/drivers/scsi/ibmvscsi/ibmvscsi.c
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -535,6 +535,7 @@ static int ibmvscsi_send_srp_event(struct srp_event_struct *evt_struct,
                                   struct ibmvscsi_host_data *hostdata)
 {
        u64 *crq_as_u64 = (u64 *) &evt_struct->crq;
+       int request_status;
        int rc;
 
        /* If we have exhausted our request limit, just fail this request.
@@ -542,9 +543,18 @@ static int ibmvscsi_send_srp_event(struct srp_event_struct *evt_struct,
         * (such as task management requests) that the mid layer may think we
         * can handle more requests (can_queue) when we actually can't
         */
-       if ((evt_struct->crq.format == VIOSRP_SRP_FORMAT) &&
-           (atomic_dec_if_positive(&hostdata->request_limit) < 0))
-               goto send_error;
+       if (evt_struct->crq.format == VIOSRP_SRP_FORMAT) {
+               request_status =
+                       atomic_dec_if_positive(&hostdata->request_limit);
+               /* If request limit was -1 when we started, it is now even
+                * less than that
+                */
+               if (request_status < -1)
+                       goto send_error;
+               /* Otherwise, if we have run out of requests */
+               else if (request_status < 0)
+                       goto send_busy;
+       }
 
        /* Copy the IU into the transfer area */
        *evt_struct->xfer_iu = evt_struct->iu;
@@ -567,11 +577,23 @@ static int ibmvscsi_send_srp_event(struct srp_event_struct *evt_struct,
 
        return 0;
 
- send_error:
+ send_busy:
        unmap_cmd_data(&evt_struct->iu.srp.cmd, evt_struct, hostdata->dev);
 
        free_event_struct(&hostdata->pool, evt_struct);
        return SCSI_MLQUEUE_HOST_BUSY;
+
+ send_error:
+       unmap_cmd_data(&evt_struct->iu.srp.cmd, evt_struct, hostdata->dev);
+
+       if (evt_struct->cmnd != NULL) {
+               evt_struct->cmnd->result = DID_ERROR << 16;
+               evt_struct->cmnd_done(evt_struct->cmnd);
+       } else if (evt_struct->done)
+               evt_struct->done(evt_struct);
+
+       free_event_struct(&hostdata->pool, evt_struct);
+       return 0;
 }
 
 /**
@@ -1184,27 +1206,37 @@ void ibmvscsi_handle_crq(struct viosrp_crq *crq,
                return;
        case 0xFF:      /* Hypervisor telling us the connection is closed */
                scsi_block_requests(hostdata->host);
+               atomic_set(&hostdata->request_limit, 0);
                if (crq->format == 0x06) {
                        /* 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)
-                               if (ibmvscsi_send_crq(hostdata,
-                                                     0xC001000000000000LL, 0))
+                       if ((ibmvscsi_reenable_crq_queue(&hostdata->queue,
+                                                       hostdata) == 0) ||
+                           (ibmvscsi_send_crq(hostdata,
+                                              0xC001000000000000LL, 0))) {
+                                       atomic_set(&hostdata->request_limit,
+                                                  -1);
                                        printk(KERN_ERR
-                                              "ibmvscsi: transmit error after"
+                                              "ibmvscsi: error after"
                                               " enable\n");
+                       }
                } else {
                        printk(KERN_INFO
                               "ibmvscsi: Virtual adapter failed rc %d!\n",
                               crq->format);
 
-                       atomic_set(&hostdata->request_limit, -1);
                        purge_requests(hostdata, DID_ERROR);
-                       ibmvscsi_reset_crq_queue(&hostdata->queue, hostdata);
+                       if ((ibmvscsi_reset_crq_queue(&hostdata->queue,
+                                                       hostdata)) ||
+                           (ibmvscsi_send_crq(hostdata,
+                                              0xC001000000000000LL, 0))) {
+                                       atomic_set(&hostdata->request_limit,
+                                                  -1);
+                                       printk(KERN_ERR
+                                              "ibmvscsi: error after reset\n");
+                       }
                }
                scsi_unblock_requests(hostdata->host);
                return;
@@ -1467,6 +1499,7 @@ static int ibmvscsi_probe(struct vio_dev *vdev, const struct vio_device_id *id)
        struct Scsi_Host *host;
        struct device *dev = &vdev->dev;
        unsigned long wait_switch = 0;
+       int rc;
 
        vdev->dev.driver_data = NULL;
 
@@ -1484,8 +1517,8 @@ static int ibmvscsi_probe(struct vio_dev *vdev, const struct vio_device_id *id)
        atomic_set(&hostdata->request_limit, -1);
        hostdata->host->max_sectors = 32 * 8; /* default max I/O 32 pages */
 
-       if (ibmvscsi_init_crq_queue(&hostdata->queue, hostdata,
-                                   max_requests) != 0) {
+       rc = ibmvscsi_init_crq_queue(&hostdata->queue, hostdata, max_requests);
+       if (rc != 0 && rc != H_RESOURCE) {
                printk(KERN_ERR "ibmvscsi: couldn't initialize crq\n");
                goto init_crq_failed;
        }
@@ -1505,7 +1538,8 @@ static int ibmvscsi_probe(struct vio_dev *vdev, const struct vio_device_id *id)
         * to fail if the other end is not acive.  In that case we don't
         * want to scan
         */
-       if (ibmvscsi_send_crq(hostdata, 0xC001000000000000LL, 0) == 0) {
+       if (ibmvscsi_send_crq(hostdata, 0xC001000000000000LL, 0) == 0
+           || rc == H_RESOURCE) {
                /*
                 * Wait around max init_timeout secs for the adapter to finish
                 * initializing. When we are done initializing, we will have a

diff --git a/drivers/scsi/ibmvscsi/rpa_vscsi.c b/drivers/scsi/ibmvscsi/rpa_vscsi.c
index 1a9992b..242b887 100644 (file)
--- a/drivers/scsi/ibmvscsi/rpa_vscsi.c
+++ b/drivers/scsi/ibmvscsi/rpa_vscsi.c
@@ -208,6 +208,7 @@ int ibmvscsi_init_crq_queue(struct crq_queue *queue,
                            int max_requests)
 {
        int rc;
+       int retrc;
        struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 
        queue->msgs = (struct viosrp_crq *)get_zeroed_page(GFP_KERNEL);
@@ -226,7 +227,7 @@ int ibmvscsi_init_crq_queue(struct crq_queue *queue,
        gather_partition_info();
        set_adapter_info(hostdata);
 
-       rc = plpar_hcall_norets(H_REG_CRQ,
+       retrc = rc = plpar_hcall_norets(H_REG_CRQ,
                                vdev->unit_address,
                                queue->msg_token, PAGE_SIZE);
        if (rc == H_RESOURCE)
@@ -263,7 +264,7 @@ int ibmvscsi_init_crq_queue(struct crq_queue *queue,
        tasklet_init(&hostdata->srp_task, (void *)ibmvscsi_task,
                     (unsigned long)hostdata);
 
-       return 0;
+       return retrc;
 
       req_irq_failed:
        do {