[PATCH v2 22/27] hpsa: add discovery polling for PT RAID devices.

Don Brace
2015-11-04T21:56:02Z

From: Scott Teel <scott.teel@pmcs.com>

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>
---
drivers/scsi/hpsa.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++
drivers/scsi/hpsa.h | 2 ++
2 files changed, 70 insertions(+)

diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index c843dd2..acfbbb2 100644
--- 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
--- 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;