github.com/SagerNet/gvisor@v0.0.0-20210707092255-7731c139d75c/pkg/sentry/device/device_test.go (about)

     1  // Copyright 2018 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package device
    16  
    17  import (
    18  	"testing"
    19  )
    20  
    21  func TestMultiDevice(t *testing.T) {
    22  	device := &MultiDevice{}
    23  
    24  	// Check that Load fails to install virtual inodes that are
    25  	// uninitialized.
    26  	if device.Load(MultiDeviceKey{}, 0) {
    27  		t.Fatalf("got load of invalid virtual inode 0, want unsuccessful")
    28  	}
    29  
    30  	inode := device.Map(MultiDeviceKey{})
    31  
    32  	// Assert that the same raw device and inode map to
    33  	// a consistent virtual inode.
    34  	if i := device.Map(MultiDeviceKey{}); i != inode {
    35  		t.Fatalf("got inode %d, want %d in %s", i, inode, device)
    36  	}
    37  
    38  	// Assert that a new inode or new device does not conflict.
    39  	if i := device.Map(MultiDeviceKey{Device: 0, Inode: 1}); i == inode {
    40  		t.Fatalf("got reused inode %d, want new distinct inode in %s", i, device)
    41  	}
    42  	last := device.Map(MultiDeviceKey{Device: 1, Inode: 0})
    43  	if last == inode {
    44  		t.Fatalf("got reused inode %d, want new distinct inode in %s", last, device)
    45  	}
    46  
    47  	// Virtual is the virtual inode we want to load.
    48  	virtual := last + 1
    49  
    50  	// Assert that we can load a virtual inode at a new place.
    51  	if !device.Load(MultiDeviceKey{Device: 0, Inode: 2}, virtual) {
    52  		t.Fatalf("got load of virtual inode %d failed, want success in %s", virtual, device)
    53  	}
    54  
    55  	// Assert that the next inode skips over the loaded one.
    56  	if i := device.Map(MultiDeviceKey{Device: 0, Inode: 3}); i != virtual+1 {
    57  		t.Fatalf("got inode %d, want %d in %s", i, virtual+1, device)
    58  	}
    59  }