firewire: convert to idr_alloc()

Convert to the much saner new idr interface.

v2: Stefan pointed out that add_client_resource() may be called from
non-process context. Preload iff @gfp_mask contains __GFP_WAIT.
Also updated to include minor upper limit check.

[[e-mail]: fix accidentally orphaned 'minor'[
Signed-off-by: Tejun Heo <[e-mail]>
Acked-by: Stefan Richter <[e-mail]>
Signed-off-by: Tim Gardner <[e-mail]>
Signed-off-by: Stefan Richter <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/firewire/core-cdev.c

···
 static int add_client_resource(struct client *client,
 			       struct client_resource *resource, gfp_t gfp_mask)
 {
+	bool preload = gfp_mask & __GFP_WAIT;
 	unsigned long flags;
 	int ret;
 
- retry:
-	if (idr_pre_get(&client->resource_idr, gfp_mask) == 0)
-		return -ENOMEM;
-
+	if (preload)
+		idr_preload(gfp_mask);
 	spin_lock_irqsave(&client->lock, flags);
+
 	if (client->in_shutdown)
 		ret = -ECANCELED;
 	else
-		ret = idr_get_new(&client->resource_idr, resource,
-				  &resource->handle);
+		ret = idr_alloc(&client->resource_idr, resource, 0, 0,
+				GFP_NOWAIT);
 	if (ret >= 0) {
+		resource->handle = ret;
 		client_get(client);
 		schedule_if_iso_resource(resource);
 	}
-	spin_unlock_irqrestore(&client->lock, flags);
 
-	if (ret == -EAGAIN)
-		goto retry;
+	spin_unlock_irqrestore(&client->lock, flags);
+	if (preload)
+		idr_preload_end();
 
 	return ret < 0 ? ret : 0;
 }

drivers/firewire/core-device.c

···
 
 	fw_device_get(device);
 	down_write(&fw_device_rwsem);
-	ret = idr_pre_get(&fw_device_idr, GFP_KERNEL) ?
-	      idr_get_new(&fw_device_idr, device, &minor) :
-	      -ENOMEM;
-	if (minor >= 1 << MINORBITS) {
-		idr_remove(&fw_device_idr, minor);
-		minor = -ENOSPC;
-	}
+	minor = idr_alloc(&fw_device_idr, device, 0, 1 << MINORBITS,
+			GFP_KERNEL);
 	up_write(&fw_device_rwsem);
 
-	if (ret < 0)
+	if (minor < 0)
 		goto error;
 
 	device->device.bus = &fw_bus_type;