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Diffstat (limited to 'pkg/sentry/fsimpl/ext/regular_file.go')
-rw-r--r-- | pkg/sentry/fsimpl/ext/regular_file.go | 159 |
1 files changed, 0 insertions, 159 deletions
diff --git a/pkg/sentry/fsimpl/ext/regular_file.go b/pkg/sentry/fsimpl/ext/regular_file.go deleted file mode 100644 index 30135ddb0..000000000 --- a/pkg/sentry/fsimpl/ext/regular_file.go +++ /dev/null @@ -1,159 +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 ext - -import ( - "io" - - "gvisor.dev/gvisor/pkg/abi/linux" - "gvisor.dev/gvisor/pkg/context" - "gvisor.dev/gvisor/pkg/safemem" - "gvisor.dev/gvisor/pkg/sentry/memmap" - "gvisor.dev/gvisor/pkg/sentry/vfs" - "gvisor.dev/gvisor/pkg/sync" - "gvisor.dev/gvisor/pkg/syserror" - "gvisor.dev/gvisor/pkg/usermem" -) - -// regularFile represents a regular file's inode. This too follows the -// inheritance pattern prevelant in the vfs layer described in -// pkg/sentry/vfs/README.md. -type regularFile struct { - inode inode - - // This is immutable. The first field of fileReader implementations must be - // regularFile to ensure temporality. - // io.ReaderAt is more strict than io.Reader in the sense that a partial read - // is always accompanied by an error. If a read spans past the end of file, a - // partial read (within file range) is done and io.EOF is returned. - impl io.ReaderAt -} - -// newRegularFile is the regularFile constructor. It figures out what kind of -// file this is and initializes the fileReader. -func newRegularFile(inode inode) (*regularFile, error) { - regFile := regularFile{ - inode: inode, - } - - inodeFlags := inode.diskInode.Flags() - - if inodeFlags.Extents { - file, err := newExtentFile(regFile) - if err != nil { - return nil, err - } - - file.regFile.inode.impl = &file.regFile - return &file.regFile, nil - } - - file, err := newBlockMapFile(regFile) - if err != nil { - return nil, err - } - file.regFile.inode.impl = &file.regFile - return &file.regFile, nil -} - -func (in *inode) isRegular() bool { - _, ok := in.impl.(*regularFile) - return ok -} - -// directoryFD represents a directory file description. It implements -// vfs.FileDescriptionImpl. -type regularFileFD struct { - fileDescription - - // off is the file offset. off is accessed using atomic memory operations. - off int64 - - // offMu serializes operations that may mutate off. - offMu sync.Mutex -} - -// Release implements vfs.FileDescriptionImpl.Release. -func (fd *regularFileFD) Release() {} - -// PRead implements vfs.FileDescriptionImpl.PRead. -func (fd *regularFileFD) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) { - safeReader := safemem.FromIOReaderAt{ - ReaderAt: fd.inode().impl.(*regularFile).impl, - Offset: offset, - } - - // Copies data from disk directly into usermem without any intermediate - // allocations (if dst is converted into BlockSeq such that it does not need - // safe copying). - return dst.CopyOutFrom(ctx, safeReader) -} - -// Read implements vfs.FileDescriptionImpl.Read. -func (fd *regularFileFD) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) { - n, err := fd.PRead(ctx, dst, fd.off, opts) - fd.offMu.Lock() - 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) { - // write(2) specifies that EBADF must be returned if the fd is not open for - // writing. - return 0, syserror.EBADF -} - -// Write implements vfs.FileDescriptionImpl.Write. -func (fd *regularFileFD) Write(ctx context.Context, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) { - n, err := fd.PWrite(ctx, src, fd.off, opts) - fd.offMu.Lock() - fd.off += n - fd.offMu.Unlock() - return n, err -} - -// IterDirents implements vfs.FileDescriptionImpl.IterDirents. -func (fd *regularFileFD) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback) error { - return syserror.ENOTDIR -} - -// 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 += int64(fd.inode().diskInode.Size()) - default: - return 0, syserror.EINVAL - } - if offset < 0 { - return 0, syserror.EINVAL - } - fd.off = offset - return offset, nil -} - -// ConfigureMMap implements vfs.FileDescriptionImpl.ConfigureMMap. -func (fd *regularFileFD) ConfigureMMap(ctx context.Context, opts *memmap.MMapOpts) error { - // TODO(b/134676337): Implement mmap(2). - return syserror.ENODEV -} |