summaryrefslogtreecommitdiffhomepage
path: root/pkg/sentry/fsimpl/memfs/regular_file.go
diff options
context:
space:
mode:
Diffstat (limited to 'pkg/sentry/fsimpl/memfs/regular_file.go')
-rw-r--r--pkg/sentry/fsimpl/memfs/regular_file.go154
1 files changed, 0 insertions, 154 deletions
diff --git a/pkg/sentry/fsimpl/memfs/regular_file.go b/pkg/sentry/fsimpl/memfs/regular_file.go
deleted file mode 100644
index b7f4853b3..000000000
--- a/pkg/sentry/fsimpl/memfs/regular_file.go
+++ /dev/null
@@ -1,154 +0,0 @@
-// Copyright 2019 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 memfs
-
-import (
- "io"
- "sync"
- "sync/atomic"
-
- "gvisor.dev/gvisor/pkg/abi/linux"
- "gvisor.dev/gvisor/pkg/sentry/context"
- "gvisor.dev/gvisor/pkg/sentry/kernel/auth"
- "gvisor.dev/gvisor/pkg/sentry/usermem"
- "gvisor.dev/gvisor/pkg/sentry/vfs"
- "gvisor.dev/gvisor/pkg/syserror"
-)
-
-type regularFile struct {
- inode inode
-
- mu sync.RWMutex
- data []byte
- // dataLen is len(data), but accessed using atomic memory operations to
- // avoid locking in inode.stat().
- dataLen int64
-}
-
-func (fs *filesystem) newRegularFile(creds *auth.Credentials, mode linux.FileMode) *inode {
- file := &regularFile{}
- file.inode.init(file, fs, creds, mode)
- file.inode.nlink = 1 // from parent directory
- return &file.inode
-}
-
-type regularFileFD struct {
- fileDescription
-
- // These are immutable.
- readable bool
- writable bool
-
- // off is the file offset. off is accessed using atomic memory operations.
- // offMu serializes operations that may mutate off.
- off int64
- offMu sync.Mutex
-}
-
-// Release implements vfs.FileDescriptionImpl.Release.
-func (fd *regularFileFD) Release() {
- if fd.writable {
- fd.vfsfd.VirtualDentry().Mount().EndWrite()
- }
-}
-
-// PRead implements vfs.FileDescriptionImpl.PRead.
-func (fd *regularFileFD) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) {
- if !fd.readable {
- return 0, syserror.EINVAL
- }
- f := fd.inode().impl.(*regularFile)
- f.mu.RLock()
- if offset >= int64(len(f.data)) {
- f.mu.RUnlock()
- return 0, io.EOF
- }
- n, err := dst.CopyOut(ctx, f.data[offset:])
- f.mu.RUnlock()
- return int64(n), err
-}
-
-// Read implements vfs.FileDescriptionImpl.Read.
-func (fd *regularFileFD) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) {
- fd.offMu.Lock()
- n, err := fd.PRead(ctx, dst, fd.off, opts)
- fd.off += n
- fd.offMu.Unlock()
- return n, err
-}
-
-// PWrite implements vfs.FileDescriptionImpl.PWrite.
-func (fd *regularFileFD) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) {
- if !fd.writable {
- return 0, syserror.EINVAL
- }
- if offset < 0 {
- return 0, syserror.EINVAL
- }
- srclen := src.NumBytes()
- if srclen == 0 {
- return 0, nil
- }
- f := fd.inode().impl.(*regularFile)
- f.mu.Lock()
- end := offset + srclen
- if end < offset {
- // Overflow.
- f.mu.Unlock()
- return 0, syserror.EFBIG
- }
- if end > f.dataLen {
- f.data = append(f.data, make([]byte, end-f.dataLen)...)
- atomic.StoreInt64(&f.dataLen, end)
- }
- n, err := src.CopyIn(ctx, f.data[offset:end])
- f.mu.Unlock()
- return int64(n), err
-}
-
-// Write implements vfs.FileDescriptionImpl.Write.
-func (fd *regularFileFD) Write(ctx context.Context, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) {
- fd.offMu.Lock()
- n, err := fd.PWrite(ctx, src, fd.off, opts)
- fd.off += n
- fd.offMu.Unlock()
- return n, err
-}
-
-// Seek implements vfs.FileDescriptionImpl.Seek.
-func (fd *regularFileFD) Seek(ctx context.Context, offset int64, whence int32) (int64, error) {
- fd.offMu.Lock()
- defer fd.offMu.Unlock()
- switch whence {
- case linux.SEEK_SET:
- // use offset as specified
- case linux.SEEK_CUR:
- offset += fd.off
- case linux.SEEK_END:
- offset += atomic.LoadInt64(&fd.inode().impl.(*regularFile).dataLen)
- default:
- return 0, syserror.EINVAL
- }
- if offset < 0 {
- return 0, syserror.EINVAL
- }
- fd.off = offset
- return offset, nil
-}
-
-// Sync implements vfs.FileDescriptionImpl.Sync.
-func (fd *regularFileFD) Sync(ctx context.Context) error {
- return nil
-}