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Diffstat (limited to 'pkg/sentry/fs/ext/extent_file.go')
-rw-r--r--pkg/sentry/fs/ext/extent_file.go147
1 files changed, 0 insertions, 147 deletions
diff --git a/pkg/sentry/fs/ext/extent_file.go b/pkg/sentry/fs/ext/extent_file.go
deleted file mode 100644
index 86583881d..000000000
--- a/pkg/sentry/fs/ext/extent_file.go
+++ /dev/null
@@ -1,147 +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/binary"
- "gvisor.dev/gvisor/pkg/sentry/fs/ext/disklayout"
- "gvisor.dev/gvisor/pkg/syserror"
-)
-
-// extentFile is a type of regular file which uses extents to store file data.
-type extentFile struct {
- regFile regularFile
-
- // root is the root extent node. This lives in the 60 byte diskInode.Data().
- // Immutable.
- root disklayout.ExtentNode
-}
-
-// Compiles only if extentFile implements fileReader.
-var _ fileReader = (*extentFile)(nil)
-
-// Read implements fileReader.getFileReader.
-func (f *extentFile) getFileReader(dev io.ReadSeeker, blkSize uint64, offset uint64) io.Reader {
- panic("unimplemented")
-}
-
-// newExtentFile is the extent file constructor. It reads the entire extent
-// tree into memory.
-//
-// Preconditions: Must hold the mutex of the filesystem containing dev.
-// TODO(b/134676337): Build extent tree on demand to reduce memory usage.
-func newExtentFile(dev io.ReadSeeker, blkSize uint64, regFile regularFile) (*extentFile, error) {
- file := &extentFile{regFile: regFile}
- file.regFile.impl = file
- err := file.buildExtTree(dev, blkSize)
- if err != nil {
- return nil, err
- }
- return file, nil
-}
-
-// buildExtTree builds the extent tree by reading it from disk by doing
-// running a simple DFS. It first reads the root node from the inode struct in
-// memory. Then it recursively builds the rest of the tree by reading it off
-// disk.
-//
-// Preconditions:
-// - Must hold the mutex of the filesystem containing dev.
-// - Inode flag InExtents must be set.
-func (f *extentFile) buildExtTree(dev io.ReadSeeker, blkSize uint64) error {
- rootNodeData := f.regFile.inode.diskInode.Data()
-
- binary.Unmarshal(rootNodeData[:disklayout.ExtentStructsSize], binary.LittleEndian, &f.root.Header)
-
- // Root node can not have more than 4 entries: 60 bytes = 1 header + 4 entries.
- if f.root.Header.NumEntries > 4 {
- // read(2) specifies that EINVAL should be returned if the file is unsuitable
- // for reading.
- return syserror.EINVAL
- }
-
- f.root.Entries = make([]disklayout.ExtentEntryPair, f.root.Header.NumEntries)
- for i, off := uint16(0), disklayout.ExtentStructsSize; i < f.root.Header.NumEntries; i, off = i+1, off+disklayout.ExtentStructsSize {
- var curEntry disklayout.ExtentEntry
- if f.root.Header.Height == 0 {
- // Leaf node.
- curEntry = &disklayout.Extent{}
- } else {
- // Internal node.
- curEntry = &disklayout.ExtentIdx{}
- }
- binary.Unmarshal(rootNodeData[off:off+disklayout.ExtentStructsSize], binary.LittleEndian, curEntry)
- f.root.Entries[i].Entry = curEntry
- }
-
- // If this node is internal, perform DFS.
- if f.root.Header.Height > 0 {
- for i := uint16(0); i < f.root.Header.NumEntries; i++ {
- var err error
- if f.root.Entries[i].Node, err = buildExtTreeFromDisk(dev, f.root.Entries[i].Entry, blkSize); err != nil {
- return err
- }
- }
- }
-
- return nil
-}
-
-// buildExtTreeFromDisk reads the extent tree nodes from disk and recursively
-// builds the tree. Performs a simple DFS. It returns the ExtentNode pointed to
-// by the ExtentEntry.
-//
-// Preconditions: Must hold the mutex of the filesystem containing dev.
-func buildExtTreeFromDisk(dev io.ReadSeeker, entry disklayout.ExtentEntry, blkSize uint64) (*disklayout.ExtentNode, error) {
- var header disklayout.ExtentHeader
- off := entry.PhysicalBlock() * blkSize
- err := readFromDisk(dev, int64(off), &header)
- if err != nil {
- return nil, err
- }
-
- entries := make([]disklayout.ExtentEntryPair, header.NumEntries)
- for i, off := uint16(0), off+disklayout.ExtentStructsSize; i < header.NumEntries; i, off = i+1, off+disklayout.ExtentStructsSize {
- var curEntry disklayout.ExtentEntry
- if header.Height == 0 {
- // Leaf node.
- curEntry = &disklayout.Extent{}
- } else {
- // Internal node.
- curEntry = &disklayout.ExtentIdx{}
- }
-
- err := readFromDisk(dev, int64(off), curEntry)
- if err != nil {
- return nil, err
- }
- entries[i].Entry = curEntry
- }
-
- // If this node is internal, perform DFS.
- if header.Height > 0 {
- for i := uint16(0); i < header.NumEntries; i++ {
- var err error
- entries[i].Node, err = buildExtTreeFromDisk(dev, entries[i].Entry, blkSize)
- if err != nil {
- return nil, err
- }
- }
- }
-
- return &disklayout.ExtentNode{header, entries}, nil
-}