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.

[tim.gardner@canonical.com: fix accidentally orphaned 'minor'[
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/firewire/core-cdev.c

@@ -487,27 +487,28 @@ static int ioctl_get_info(struct client *client, union ioctl_arg *arg)
 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

@@ -1017,16 +1017,11 @@ static void fw_device_init(struct work_struct *work)
 
 	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;