mtip32xx: Fix for rmmod crash when drive is in FTL rebuild

commit 59cf70e2 upstream.

When FTL rebuild is in progress, alloc_disk() initializes the disk
but device node will be created by add_disk() only after successful
completion of FTL rebuild. So, skip deletion of device node in
removal path when FTL rebuild is in progress.
Signed-off-by: Selvan Mani <smani@micron.com>
Signed-off-by: Asai Thambi S P <asamymuthupa@micron.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

drivers/block/mtip32xx/mtip32xx.c

@@ -2975,10 +2975,8 @@ static int mtip_service_thread(void *data)
 		}
 
 		if (test_bit(MTIP_PF_REBUILD_BIT, &port->flags)) {
-			if (mtip_ftl_rebuild_poll(dd) < 0)
-				set_bit(MTIP_DDF_REBUILD_FAILED_BIT,
-							&dd->dd_flag);
-			clear_bit(MTIP_PF_REBUILD_BIT, &port->flags);
+			if (mtip_ftl_rebuild_poll(dd) == 0)
+				clear_bit(MTIP_PF_REBUILD_BIT, &port->flags);
 		}
 	}
 
@@ -3859,7 +3857,6 @@ static int mtip_block_initialize(struct driver_data *dd)
 
 	mtip_hw_debugfs_init(dd);
 
-skip_create_disk:
 	memset(&dd->tags, 0, sizeof(dd->tags));
 	dd->tags.ops = &mtip_mq_ops;
 	dd->tags.nr_hw_queues = 1;
@@ -3889,6 +3886,7 @@ static int mtip_block_initialize(struct driver_data *dd)
 	dd->disk->queue		= dd->queue;
 	dd->queue->queuedata	= dd;
 
+skip_create_disk:
 	/* Initialize the protocol layer. */
 	wait_for_rebuild = mtip_hw_get_identify(dd);
 	if (wait_for_rebuild < 0) {
@@ -4050,7 +4048,8 @@ static int mtip_block_remove(struct driver_data *dd)
 		dd->bdev = NULL;
 	}
 	if (dd->disk) {
-		del_gendisk(dd->disk);
+		if (test_bit(MTIP_DDF_INIT_DONE_BIT, &dd->dd_flag))
+			del_gendisk(dd->disk);
 		if (dd->disk->queue) {
 			blk_cleanup_queue(dd->queue);
 			blk_mq_free_tag_set(&dd->tags);
@@ -4091,7 +4090,8 @@ static int mtip_block_shutdown(struct driver_data *dd)
 		dev_info(&dd->pdev->dev,
 			"Shutting down %s ...\n", dd->disk->disk_name);
 
-		del_gendisk(dd->disk);
+		if (test_bit(MTIP_DDF_INIT_DONE_BIT, &dd->dd_flag))
+			del_gendisk(dd->disk);
 		if (dd->disk->queue) {
 			blk_cleanup_queue(dd->queue);
 			blk_mq_free_tag_set(&dd->tags);