summaryrefslogtreecommitdiffhomepage
path: root/pkg/sentry/fs/ext/inode.go
diff options
context:
space:
mode:
Diffstat (limited to 'pkg/sentry/fs/ext/inode.go')
-rw-r--r--pkg/sentry/fs/ext/inode.go159
1 files changed, 0 insertions, 159 deletions
diff --git a/pkg/sentry/fs/ext/inode.go b/pkg/sentry/fs/ext/inode.go
deleted file mode 100644
index 364980e4c..000000000
--- a/pkg/sentry/fs/ext/inode.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"
- "sync/atomic"
-
- "gvisor.dev/gvisor/pkg/abi/linux"
- "gvisor.dev/gvisor/pkg/sentry/context"
- "gvisor.dev/gvisor/pkg/sentry/fs/ext/disklayout"
- "gvisor.dev/gvisor/pkg/syserror"
-)
-
-// inode represents an ext inode.
-//
-// inode uses the same inheritance pattern that pkg/sentry/vfs structures use.
-// This has been done to increase memory locality.
-//
-// Implementations:
-// inode --
-// |-- pipe
-// |-- dir
-// |-- symlink
-// |-- regular--
-// |-- extent file
-// |-- block map file
-// |-- inline file
-type inode struct {
- // refs is a reference count. refs is accessed using atomic memory operations.
- refs int64
-
- // inodeNum is the inode number of this inode on disk. This is used to
- // identify inodes within the ext filesystem.
- inodeNum uint32
-
- // dev represents the underlying device. Same as filesystem.dev.
- dev io.ReaderAt
-
- // blkSize is the fs data block size. Same as filesystem.sb.BlockSize().
- blkSize uint64
-
- // diskInode gives us access to the inode struct on disk. Immutable.
- diskInode disklayout.Inode
-
- // This is immutable. The first field of the implementations must have inode
- // as the first field to ensure temporality.
- impl interface{}
-}
-
-// incRef increments the inode ref count.
-func (in *inode) incRef() {
- atomic.AddInt64(&in.refs, 1)
-}
-
-// tryIncRef tries to increment the ref count. Returns true if successful.
-func (in *inode) tryIncRef() bool {
- for {
- refs := atomic.LoadInt64(&in.refs)
- if refs == 0 {
- return false
- }
- if atomic.CompareAndSwapInt64(&in.refs, refs, refs+1) {
- return true
- }
- }
-}
-
-// decRef decrements the inode ref count and releases the inode resources if
-// the ref count hits 0.
-//
-// Precondition: Must have locked fs.mu.
-func (in *inode) decRef(fs *filesystem) {
- if refs := atomic.AddInt64(&in.refs, -1); refs == 0 {
- delete(fs.inodeCache, in.inodeNum)
- } else if refs < 0 {
- panic("ext.inode.decRef() called without holding a reference")
- }
-}
-
-// newInode is the inode constructor. Reads the inode off disk. Identifies
-// inodes based on the absolute inode number on disk.
-func newInode(ctx context.Context, fs *filesystem, inodeNum uint32) (*inode, error) {
- if inodeNum == 0 {
- panic("inode number 0 on ext filesystems is not possible")
- }
-
- inodeRecordSize := fs.sb.InodeSize()
- var diskInode disklayout.Inode
- if inodeRecordSize == disklayout.OldInodeSize {
- diskInode = &disklayout.InodeOld{}
- } else {
- diskInode = &disklayout.InodeNew{}
- }
-
- // Calculate where the inode is actually placed.
- inodesPerGrp := fs.sb.InodesPerGroup()
- blkSize := fs.sb.BlockSize()
- inodeTableOff := fs.bgs[getBGNum(inodeNum, inodesPerGrp)].InodeTable() * blkSize
- inodeOff := inodeTableOff + uint64(uint32(inodeRecordSize)*getBGOff(inodeNum, inodesPerGrp))
-
- if err := readFromDisk(fs.dev, int64(inodeOff), diskInode); err != nil {
- return nil, err
- }
-
- // Build the inode based on its type.
- inode := inode{
- refs: 1,
- inodeNum: inodeNum,
- dev: fs.dev,
- blkSize: blkSize,
- diskInode: diskInode,
- }
-
- switch diskInode.Mode().FileType() {
- case linux.ModeSymlink:
- f, err := newSymlink(inode)
- if err != nil {
- return nil, err
- }
- return &f.inode, nil
- case linux.ModeRegular:
- f, err := newRegularFile(inode)
- if err != nil {
- return nil, err
- }
- return &f.inode, nil
- case linux.ModeDirectory:
- return &newDirectroy(inode).inode, nil
- case linux.ModeNamedPipe:
- return &newNamedPipe(ctx, inode).inode, nil
- default:
- // TODO(b/134676337): Return appropriate errors for sockets and devices.
- return nil, syserror.EINVAL
- }
-}
-
-// getBGNum returns the block group number that a given inode belongs to.
-func getBGNum(inodeNum uint32, inodesPerGrp uint32) uint32 {
- return (inodeNum - 1) / inodesPerGrp
-}
-
-// getBGOff returns the offset at which the given inode lives in the block
-// group's inode table, i.e. the index of the inode in the inode table.
-func getBGOff(inodeNum uint32, inodesPerGrp uint32) uint32 {
- return (inodeNum - 1) % inodesPerGrp
-}