Btrfs: fix resize a readonly device

We should not resize a readonly device, fix it.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

fs/btrfs/ioctl.c

@@ -1362,6 +1362,7 @@ static noinline int btrfs_ioctl_resize(struct file *file,
 		printk(KERN_INFO "btrfs: resizing devid %llu\n",
 		       (unsigned long long)devid);
 	}
+
 	device = btrfs_find_device(root->fs_info, devid, NULL, NULL);
 	if (!device) {
 		printk(KERN_INFO "btrfs: resizer unable to find device %llu\n",
@@ -1369,9 +1370,10 @@ static noinline int btrfs_ioctl_resize(struct file *file,
 		ret = -EINVAL;
 		goto out_free;
 	}
-	if (device->fs_devices && device->fs_devices->seeding) {
+
+	if (!device->writeable) {
 		printk(KERN_INFO "btrfs: resizer unable to apply on "
-		       "seeding device %llu\n",
+		       "readonly device %llu\n",
 		       (unsigned long long)devid);
 		ret = -EINVAL;
 		goto out_free;