hpsa: add discovery polling for PT RAID devices.

There are problems with getting configuration change notification
in pass-through RAID environments.  So, activate flag
h->discovery_polling when one of these devices is detected in
update_scsi_devices.

After discovery_polling is set, execute a report luns from
rescan_controller_worker (every 30 seconds).

If the data from report_luns is different than last
time (binary compare), execute a full rescan via update_scsi_devices.

Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Justin Lindley <justin.lindley@pmcs.com>
Reviewed-by: Kevin Barnett <kevin.barnett@pmcs.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index c843dd2..acfbbb2 100644 (file)
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -275,6 +275,7 @@ static int hpsa_scsi_ioaccel_queue_command(struct ctlr_info *h,
 static void hpsa_command_resubmit_worker(struct work_struct *work);
 static u32 lockup_detected(struct ctlr_info *h);
 static int detect_controller_lockup(struct ctlr_info *h);
+static int hpsa_luns_changed(struct ctlr_info *h);
 
 static inline struct ctlr_info *sdev_to_hba(struct scsi_device *sdev)
 {
@@ -3898,6 +3899,18 @@ static void hpsa_update_scsi_devices(struct ctlr_info *h)
                hpsa_update_device_supports_aborts(h, tmpdevice, lunaddrbytes);
                this_device = currentsd[ncurrent];
 
+               /* Turn on discovery_polling if there are ext target devices.
+                * Event-based change notification is unreliable for those.
+                */
+               if (!h->discovery_polling) {
+                       if (tmpdevice->external) {
+                               h->discovery_polling = 1;
+                               dev_info(&h->pdev->dev,
+                                       "External target, activate discovery polling.\n");
+                       }
+               }
+
+
                *this_device = *tmpdevice;
                this_device->physical_device = physical_device;
 
@@ -8016,6 +8029,41 @@ static int hpsa_offline_devices_ready(struct ctlr_info *h)
        return 0;
 }
 
+static int hpsa_luns_changed(struct ctlr_info *h)
+{
+       int rc = 1; /* assume there are changes */
+       struct ReportLUNdata *logdev = NULL;
+
+       /* if we can't find out if lun data has changed,
+        * assume that it has.
+        */
+
+       if (!h->lastlogicals)
+               goto out;
+
+       logdev = kzalloc(sizeof(*logdev), GFP_KERNEL);
+       if (!logdev) {
+               dev_warn(&h->pdev->dev,
+                       "Out of memory, can't track lun changes.\n");
+               goto out;
+       }
+       if (hpsa_scsi_do_report_luns(h, 1, logdev, sizeof(*logdev), 0)) {
+               dev_warn(&h->pdev->dev,
+                       "report luns failed, can't track lun changes.\n");
+               goto out;
+       }
+       if (memcmp(logdev, h->lastlogicals, sizeof(*logdev))) {
+               dev_info(&h->pdev->dev,
+                       "Lun changes detected.\n");
+               memcpy(h->lastlogicals, logdev, sizeof(*logdev));
+               goto out;
+       } else
+               rc = 0; /* no changes detected. */
+out:
+       kfree(logdev);
+       return rc;
+}
+
 static void hpsa_rescan_ctlr_worker(struct work_struct *work)
 {
        unsigned long flags;
@@ -8031,6 +8079,18 @@ static void hpsa_rescan_ctlr_worker(struct work_struct *work)
                hpsa_ack_ctlr_events(h);
                hpsa_scan_start(h->scsi_host);
                scsi_host_put(h->scsi_host);
+       } else if (h->discovery_polling) {
+               if (hpsa_luns_changed(h)) {
+                       struct Scsi_Host *sh = NULL;
+
+                       dev_info(&h->pdev->dev,
+                               "driver discovery polling rescan.\n");
+                       sh = scsi_host_get(h->scsi_host);
+                       if (sh != NULL) {
+                               hpsa_scan_start(sh);
+                               scsi_host_put(sh);
+                       }
+               }
        }
        spin_lock_irqsave(&h->lock, flags);
        if (!h->remove_in_progress)
@@ -8271,6 +8331,8 @@ reinit_after_soft_reset:
 
        /* Enable Accelerated IO path at driver layer */
        h->acciopath_status = 1;
+       /* Disable discovery polling.*/
+       h->discovery_polling = 0;
 
 
        /* Turn the interrupts on so we can service requests */
@@ -8278,6 +8340,11 @@ reinit_after_soft_reset:
 
        hpsa_hba_inquiry(h);
 
+       h->lastlogicals = kzalloc(sizeof(*(h->lastlogicals)), GFP_KERNEL);
+       if (!h->lastlogicals)
+               dev_info(&h->pdev->dev,
+                       "Can't track change to report lun data\n");
+
        /* Monitor the controller for firmware lockups */
        h->heartbeat_sample_interval = HEARTBEAT_SAMPLE_INTERVAL;
        INIT_DELAYED_WORK(&h->monitor_ctlr_work, hpsa_monitor_ctlr_worker);
@@ -8415,6 +8482,7 @@ static void hpsa_remove_one(struct pci_dev *pdev)
        hpsa_free_performant_mode(h);                   /* init_one 7 */
        hpsa_free_sg_chain_blocks(h);                   /* init_one 6 */
        hpsa_free_cmd_pool(h);                          /* init_one 5 */
+       kfree(h->lastlogicals);
 
        /* hpsa_free_irqs already called via hpsa_shutdown init_one 4 */
 

diff --git a/drivers/scsi/hpsa.h b/drivers/scsi/hpsa.h
index ffcd4cb..9c983a9 100644 (file)
--- a/drivers/scsi/hpsa.h
+++ b/drivers/scsi/hpsa.h
@@ -262,6 +262,8 @@ struct ctlr_info {
        int     acciopath_status;
        int     drv_req_rescan;
        int     raid_offload_debug;
+       int     discovery_polling;
+       struct  ReportLUNdata *lastlogicals;
        int     needs_abort_tags_swizzled;
        struct workqueue_struct *resubmit_wq;
        struct workqueue_struct *rescan_ctlr_wq;