[PATCH 05/21] hpsa: fix hpsa_adjust_hpsa_scsi_table

[Don Brace <don.brace@pmcs.com>]

Fix a NULL pointer issue in the driver when devices are removed
during a reset.

Signed-off-by: Don Brace <don.brace@pmcs.com>
---
 drivers/block/cciss.h |    1 +
 drivers/scsi/hpsa.c   |   16 ++++++++++++++++
 drivers/scsi/hpsa.h   |    1 +
 3 files changed, 18 insertions(+)

diff --git a/drivers/block/cciss.h b/drivers/block/cciss.h
index 7fda30e..036fb0f 100644
--- a/drivers/block/cciss.h
+++ b/drivers/block/cciss.h
@@ -155,6 +155,7 @@ struct ctlr_info
 	size_t reply_pool_size;
 	unsigned char reply_pool_wraparound;
 	u32 *blockFetchTable;
+	atomic_t reset_in_progress;
 };
 
 /*  Defining the diffent access_methods
diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 3520d75..714bb76 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -1656,6 +1656,11 @@ static void adjust_hpsa_scsi_table(struct ctlr_info *h, int hostno,
 	int nadded, nremoved;
 	struct Scsi_Host *sh = NULL;
 
+	if (atomic_read(&h->reset_in_progress)) {
+		h->drv_req_rescan = 1;
+		return;
+	}
+
 	added = kzalloc(sizeof(*added) * HPSA_MAX_DEVICES, GFP_KERNEL);
 	removed = kzalloc(sizeof(*removed) * HPSA_MAX_DEVICES, GFP_KERNEL);
 
@@ -1764,8 +1769,14 @@ static void adjust_hpsa_scsi_table(struct ctlr_info *h, int hostno,
 		goto free_and_out;
 
 	sh = h->scsi_host;
+	if (sh == NULL) {
+		dev_warn(&h->pdev->dev, "%s: scsi_host is null\n", __func__);
+		return;
+	}
 	/* Notify scsi mid layer of any removed devices */
 	for (i = 0; i < nremoved; i++) {
+		if (!removed[i])
+			continue;
 		if (removed[i]->expose_state & HPSA_SCSI_ADD) {
 			struct scsi_device *sdev =
 				scsi_device_lookup(sh, removed[i]->bus,
@@ -1790,6 +1801,8 @@ static void adjust_hpsa_scsi_table(struct ctlr_info *h, int hostno,
 
 	/* Notify scsi mid layer of any added devices */
 	for (i = 0; i < nadded; i++) {
+		if (!added[i])
+			continue;
 		if (!(added[i]->expose_state & HPSA_SCSI_ADD))
 			continue;
 		if (scsi_add_device(sh, added[i]->bus,
@@ -5227,12 +5240,15 @@ static int hpsa_eh_device_reset_handler(struct scsi_cmnd *scsicmd)
 
 	hpsa_show_dev_msg(__stringify(KERN_WARNING), h, dev, "resetting");
 
+	atomic_set(&h->reset_in_progress, 1);
+
 	/* send a reset to the SCSI LUN which the command was sent to */
 	rc = hpsa_do_reset(h, dev, dev->scsi3addr, HPSA_RESET_TYPE_LUN,
 			   DEFAULT_REPLY_QUEUE);
 	snprintf(msg, sizeof(msg), "reset %s",
 		 rc == 0 ? "completed successfully" : "failed");
 	hpsa_show_dev_msg(__stringify(KERN_WARNING), h, dev, msg);
+	atomic_set(&h->reset_in_progress, 0);
 	return rc == 0 ? SUCCESS : FAILED;
 }
 
diff --git a/drivers/scsi/hpsa.h b/drivers/scsi/hpsa.h
index 642c8ce..c7c1697 100644
--- a/drivers/scsi/hpsa.h
+++ b/drivers/scsi/hpsa.h
@@ -271,6 +271,7 @@ struct ctlr_info {
 	wait_queue_head_t abort_cmd_wait_queue;
 	wait_queue_head_t event_sync_wait_queue;
 	struct mutex reset_mutex;
+	atomic_t reset_in_progress;
 };
 
 struct offline_device_entry {