github.com/SagerNet/gvisor@v0.0.0-20210707092255-7731c139d75c/pkg/sentry/fsimpl/ext/file_description.go (about)

     1  // Copyright 2019 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 ext
    16  
    17  import (
    18  	"github.com/SagerNet/gvisor/pkg/abi/linux"
    19  	"github.com/SagerNet/gvisor/pkg/context"
    20  	"github.com/SagerNet/gvisor/pkg/errors/linuxerr"
    21  	"github.com/SagerNet/gvisor/pkg/sentry/vfs"
    22  )
    23  
    24  // fileDescription is embedded by ext implementations of
    25  // vfs.FileDescriptionImpl.
    26  type fileDescription struct {
    27  	vfsfd vfs.FileDescription
    28  	vfs.FileDescriptionDefaultImpl
    29  	vfs.LockFD
    30  }
    31  
    32  func (fd *fileDescription) filesystem() *filesystem {
    33  	return fd.vfsfd.Mount().Filesystem().Impl().(*filesystem)
    34  }
    35  
    36  func (fd *fileDescription) inode() *inode {
    37  	return fd.vfsfd.Dentry().Impl().(*dentry).inode
    38  }
    39  
    40  // Stat implements vfs.FileDescriptionImpl.Stat.
    41  func (fd *fileDescription) Stat(ctx context.Context, opts vfs.StatOptions) (linux.Statx, error) {
    42  	var stat linux.Statx
    43  	fd.inode().statTo(&stat)
    44  	return stat, nil
    45  }
    46  
    47  // SetStat implements vfs.FileDescriptionImpl.SetStat.
    48  func (fd *fileDescription) SetStat(ctx context.Context, opts vfs.SetStatOptions) error {
    49  	if opts.Stat.Mask == 0 {
    50  		return nil
    51  	}
    52  	return linuxerr.EPERM
    53  }
    54  
    55  // SetStat implements vfs.FileDescriptionImpl.StatFS.
    56  func (fd *fileDescription) StatFS(ctx context.Context) (linux.Statfs, error) {
    57  	var stat linux.Statfs
    58  	fd.filesystem().statTo(&stat)
    59  	return stat, nil
    60  }
    61  
    62  // Sync implements vfs.FileDescriptionImpl.Sync.
    63  func (fd *fileDescription) Sync(ctx context.Context) error {
    64  	return nil
    65  }