// Copyright 2020 The gVisor Authors. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. package fuse import ( "gvisor.dev/gvisor/pkg/abi/linux" "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sentry/vfs" "gvisor.dev/gvisor/pkg/usermem" ) // fileDescription implements vfs.FileDescriptionImpl for fuse. type fileDescription struct { vfsfd vfs.FileDescription vfs.FileDescriptionDefaultImpl vfs.DentryMetadataFileDescriptionImpl vfs.NoLockFD // the file handle used in userspace. Fh uint64 // Nonseekable is indicate cannot perform seek on a file. Nonseekable bool // DirectIO suggest fuse to use direct io operation. DirectIO bool // OpenFlag is the flag returned by open. OpenFlag uint32 // off is the file offset. off int64 } func (fd *fileDescription) dentry() *kernfs.Dentry { return fd.vfsfd.Dentry().Impl().(*kernfs.Dentry) } func (fd *fileDescription) inode() *inode { return fd.dentry().Inode().(*inode) } func (fd *fileDescription) filesystem() *vfs.Filesystem { return fd.vfsfd.VirtualDentry().Mount().Filesystem() } func (fd *fileDescription) statusFlags() uint32 { return fd.vfsfd.StatusFlags() } // Release implements vfs.FileDescriptionImpl.Release. func (fd *fileDescription) Release(ctx context.Context) { // no need to release if FUSE server doesn't implement Open. conn := fd.inode().fs.conn if conn.noOpen { return } in := linux.FUSEReleaseIn{ Fh: fd.Fh, Flags: fd.statusFlags(), } // TODO(gvisor.dev/issue/3245): add logic when we support file lock owner. var opcode linux.FUSEOpcode if fd.inode().Mode().IsDir() { opcode = linux.FUSE_RELEASEDIR } else { opcode = linux.FUSE_RELEASE } kernelTask := kernel.TaskFromContext(ctx) // ignoring errors and FUSE server reply is analogous to Linux's behavior. req, _ := conn.NewRequest(auth.CredentialsFromContext(ctx), uint32(kernelTask.ThreadID()), fd.inode().NodeID, opcode, &in) conn.CallAsync(kernelTask, req) } // PRead implements vfs.FileDescriptionImpl.PRead. func (fd *fileDescription) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) { return 0, nil } // Read implements vfs.FileDescriptionImpl.Read. func (fd *fileDescription) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) { return 0, nil } // PWrite implements vfs.FileDescriptionImpl.PWrite. func (fd *fileDescription) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) { return 0, nil } // Write implements vfs.FileDescriptionImpl.Write. func (fd *fileDescription) Write(ctx context.Context, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) { return 0, nil } // Seek implements vfs.FileDescriptionImpl.Seek. func (fd *fileDescription) Seek(ctx context.Context, offset int64, whence int32) (int64, error) { return 0, nil } // Stat implements vfs.FileDescriptionImpl.Stat. func (fd *fileDescription) Stat(ctx context.Context, opts vfs.StatOptions) (linux.Statx, error) { fs := fd.filesystem() inode := fd.inode() return inode.Stat(ctx, fs, opts) } // SetStat implements FileDescriptionImpl.SetStat. func (fd *fileDescription) SetStat(ctx context.Context, opts vfs.SetStatOptions) error { creds := auth.CredentialsFromContext(ctx) return fd.inode().SetStat(ctx, fd.inode().fs.VFSFilesystem(), creds, opts) }