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Diffstat (limited to 'pkg/sentry/fsimpl/ext/directory.go')
-rw-r--r--pkg/sentry/fsimpl/ext/directory.go307
1 files changed, 0 insertions, 307 deletions
diff --git a/pkg/sentry/fsimpl/ext/directory.go b/pkg/sentry/fsimpl/ext/directory.go
deleted file mode 100644
index ebb72b75e..000000000
--- a/pkg/sentry/fsimpl/ext/directory.go
+++ /dev/null
@@ -1,307 +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 (
- "gvisor.dev/gvisor/pkg/abi/linux"
- "gvisor.dev/gvisor/pkg/binary"
- "gvisor.dev/gvisor/pkg/context"
- "gvisor.dev/gvisor/pkg/log"
- "gvisor.dev/gvisor/pkg/sentry/fs"
- "gvisor.dev/gvisor/pkg/sentry/fsimpl/ext/disklayout"
- "gvisor.dev/gvisor/pkg/sentry/memmap"
- "gvisor.dev/gvisor/pkg/sentry/vfs"
- "gvisor.dev/gvisor/pkg/sync"
- "gvisor.dev/gvisor/pkg/syserror"
-)
-
-// directory represents a directory inode. It holds the childList in memory.
-type directory struct {
- inode inode
-
- // mu serializes the changes to childList.
- // Lock Order (outermost locks must be taken first):
- // directory.mu
- // filesystem.mu
- mu sync.Mutex
-
- // childList is a list containing (1) child dirents and (2) fake dirents
- // (with diskDirent == nil) that represent the iteration position of
- // directoryFDs. childList is used to support directoryFD.IterDirents()
- // efficiently. childList is protected by mu.
- childList direntList
-
- // childMap maps the child's filename to the dirent structure stored in
- // childList. This adds some data replication but helps in faster path
- // traversal. For consistency, key == childMap[key].diskDirent.FileName().
- // Immutable.
- childMap map[string]*dirent
-}
-
-// newDirectroy is the directory constructor.
-func newDirectroy(inode inode, newDirent bool) (*directory, error) {
- file := &directory{inode: inode, childMap: make(map[string]*dirent)}
- file.inode.impl = file
-
- // Initialize childList by reading dirents from the underlying file.
- if inode.diskInode.Flags().Index {
- // TODO(b/134676337): Support hash tree directories. Currently only the '.'
- // and '..' entries are read in.
-
- // Users cannot navigate this hash tree directory yet.
- log.Warningf("hash tree directory being used which is unsupported")
- return file, nil
- }
-
- // The dirents are organized in a linear array in the file data.
- // Extract the file data and decode the dirents.
- regFile, err := newRegularFile(inode)
- if err != nil {
- return nil, err
- }
-
- // buf is used as scratch space for reading in dirents from disk and
- // unmarshalling them into dirent structs.
- buf := make([]byte, disklayout.DirentSize)
- size := inode.diskInode.Size()
- for off, inc := uint64(0), uint64(0); off < size; off += inc {
- toRead := size - off
- if toRead > disklayout.DirentSize {
- toRead = disklayout.DirentSize
- }
- if n, err := regFile.impl.ReadAt(buf[:toRead], int64(off)); uint64(n) < toRead {
- return nil, err
- }
-
- var curDirent dirent
- if newDirent {
- curDirent.diskDirent = &disklayout.DirentNew{}
- } else {
- curDirent.diskDirent = &disklayout.DirentOld{}
- }
- binary.Unmarshal(buf, binary.LittleEndian, curDirent.diskDirent)
-
- if curDirent.diskDirent.Inode() != 0 && len(curDirent.diskDirent.FileName()) != 0 {
- // Inode number and name length fields being set to 0 is used to indicate
- // an unused dirent.
- file.childList.PushBack(&curDirent)
- file.childMap[curDirent.diskDirent.FileName()] = &curDirent
- }
-
- // The next dirent is placed exactly after this dirent record on disk.
- inc = uint64(curDirent.diskDirent.RecordSize())
- }
-
- return file, nil
-}
-
-func (i *inode) isDir() bool {
- _, ok := i.impl.(*directory)
- return ok
-}
-
-// dirent is the directory.childList node.
-type dirent struct {
- diskDirent disklayout.Dirent
-
- // direntEntry links dirents into their parent directory.childList.
- direntEntry
-}
-
-// directoryFD represents a directory file description. It implements
-// vfs.FileDescriptionImpl.
-type directoryFD struct {
- fileDescription
- vfs.DirectoryFileDescriptionDefaultImpl
-
- // Protected by directory.mu.
- iter *dirent
- off int64
-}
-
-// Compiles only if directoryFD implements vfs.FileDescriptionImpl.
-var _ vfs.FileDescriptionImpl = (*directoryFD)(nil)
-
-// Release implements vfs.FileDescriptionImpl.Release.
-func (fd *directoryFD) Release() {
- if fd.iter == nil {
- return
- }
-
- dir := fd.inode().impl.(*directory)
- dir.mu.Lock()
- dir.childList.Remove(fd.iter)
- dir.mu.Unlock()
- fd.iter = nil
-}
-
-// IterDirents implements vfs.FileDescriptionImpl.IterDirents.
-func (fd *directoryFD) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback) error {
- extfs := fd.filesystem()
- dir := fd.inode().impl.(*directory)
-
- dir.mu.Lock()
- defer dir.mu.Unlock()
-
- // Ensure that fd.iter exists and is not linked into dir.childList.
- var child *dirent
- if fd.iter == nil {
- // Start iteration at the beginning of dir.
- child = dir.childList.Front()
- fd.iter = &dirent{}
- } else {
- // Continue iteration from where we left off.
- child = fd.iter.Next()
- dir.childList.Remove(fd.iter)
- }
- for ; child != nil; child = child.Next() {
- // Skip other directoryFD iterators.
- if child.diskDirent != nil {
- childType, ok := child.diskDirent.FileType()
- if !ok {
- // We will need to read the inode off disk. Do not increment
- // ref count here because this inode is not being added to the
- // dentry tree.
- extfs.mu.Lock()
- childInode, err := extfs.getOrCreateInodeLocked(child.diskDirent.Inode())
- extfs.mu.Unlock()
- if err != nil {
- // Usage of the file description after the error is
- // undefined. This implementation would continue reading
- // from the next dirent.
- fd.off++
- dir.childList.InsertAfter(child, fd.iter)
- return err
- }
- childType = fs.ToInodeType(childInode.diskInode.Mode().FileType())
- }
-
- if !cb.Handle(vfs.Dirent{
- Name: child.diskDirent.FileName(),
- Type: fs.ToDirentType(childType),
- Ino: uint64(child.diskDirent.Inode()),
- NextOff: fd.off + 1,
- }) {
- dir.childList.InsertBefore(child, fd.iter)
- return nil
- }
- fd.off++
- }
- }
- dir.childList.PushBack(fd.iter)
- return nil
-}
-
-// Seek implements vfs.FileDescriptionImpl.Seek.
-func (fd *directoryFD) Seek(ctx context.Context, offset int64, whence int32) (int64, error) {
- if whence != linux.SEEK_SET && whence != linux.SEEK_CUR {
- return 0, syserror.EINVAL
- }
-
- dir := fd.inode().impl.(*directory)
-
- dir.mu.Lock()
- defer dir.mu.Unlock()
-
- // Find resulting offset.
- if whence == linux.SEEK_CUR {
- offset += fd.off
- }
-
- if offset < 0 {
- // lseek(2) specifies that EINVAL should be returned if the resulting offset
- // is negative.
- return 0, syserror.EINVAL
- }
-
- n := int64(len(dir.childMap))
- realWantOff := offset
- if realWantOff > n {
- realWantOff = n
- }
- realCurOff := fd.off
- if realCurOff > n {
- realCurOff = n
- }
-
- // Ensure that fd.iter exists and is linked into dir.childList so we can
- // intelligently seek from the optimal position.
- if fd.iter == nil {
- fd.iter = &dirent{}
- dir.childList.PushFront(fd.iter)
- }
-
- // Guess that iterating from the current position is optimal.
- child := fd.iter
- diff := realWantOff - realCurOff // Shows direction and magnitude of travel.
-
- // See if starting from the beginning or end is better.
- abDiff := diff
- if diff < 0 {
- abDiff = -diff
- }
- if abDiff > realWantOff {
- // Starting from the beginning is best.
- child = dir.childList.Front()
- diff = realWantOff
- } else if abDiff > (n - realWantOff) {
- // Starting from the end is best.
- child = dir.childList.Back()
- // (n - 1) because the last non-nil dirent represents the (n-1)th offset.
- diff = realWantOff - (n - 1)
- }
-
- for child != nil {
- // Skip other directoryFD iterators.
- if child.diskDirent != nil {
- if diff == 0 {
- if child != fd.iter {
- dir.childList.Remove(fd.iter)
- dir.childList.InsertBefore(child, fd.iter)
- }
-
- fd.off = offset
- return offset, nil
- }
-
- if diff < 0 {
- diff++
- child = child.Prev()
- } else {
- diff--
- child = child.Next()
- }
- continue
- }
-
- if diff < 0 {
- child = child.Prev()
- } else {
- child = child.Next()
- }
- }
-
- // Reaching here indicates that the offset is beyond the end of the childList.
- dir.childList.Remove(fd.iter)
- dir.childList.PushBack(fd.iter)
- fd.off = offset
- return offset, nil
-}
-
-// ConfigureMMap implements vfs.FileDescriptionImpl.ConfigureMMap.
-func (fd *directoryFD) ConfigureMMap(ctx context.Context, opts *memmap.MMapOpts) error {
- // mmap(2) specifies that EACCESS should be returned for non-regular file fds.
- return syserror.EACCES
-}