github.com/SagerNet/gvisor@v0.0.0-20210707092255-7731c139d75c/pkg/sentry/fs/host/descriptor_state.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 host
    16  
    17  // beforeSave is invoked by stateify.
    18  func (d *descriptor) beforeSave() {
    19  	if d.origFD < 0 {
    20  		panic("donated file descriptor cannot be saved")
    21  	}
    22  }
    23  
    24  // afterLoad is invoked by stateify.
    25  func (d *descriptor) afterLoad() {
    26  	// value must be manually restored by the descriptor's parent using
    27  	// initAfterLoad.
    28  	d.value = -1
    29  }