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-rw-r--r--pkg/sentry/fsimpl/gofer/BUILD89
-rw-r--r--pkg/sentry/fsimpl/gofer/dentry_list.go193
-rw-r--r--pkg/sentry/fsimpl/gofer/fstree.go46
-rw-r--r--pkg/sentry/fsimpl/gofer/gofer_state_autogen.go64
-rw-r--r--pkg/sentry/fsimpl/gofer/gofer_test.go63
5 files changed, 303 insertions, 152 deletions
diff --git a/pkg/sentry/fsimpl/gofer/BUILD b/pkg/sentry/fsimpl/gofer/BUILD
deleted file mode 100644
index 4a800dcf9..000000000
--- a/pkg/sentry/fsimpl/gofer/BUILD
+++ /dev/null
@@ -1,89 +0,0 @@
-load("//tools:defs.bzl", "go_library", "go_test")
-load("//tools/go_generics:defs.bzl", "go_template_instance")
-
-licenses(["notice"])
-
-go_template_instance(
- name = "dentry_list",
- out = "dentry_list.go",
- package = "gofer",
- prefix = "dentry",
- template = "//pkg/ilist:generic_list",
- types = {
- "Element": "*dentry",
- "Linker": "*dentry",
- },
-)
-
-go_template_instance(
- name = "fstree",
- out = "fstree.go",
- package = "gofer",
- prefix = "generic",
- template = "//pkg/sentry/vfs/genericfstree:generic_fstree",
- types = {
- "Dentry": "dentry",
- },
-)
-
-go_library(
- name = "gofer",
- srcs = [
- "dentry_list.go",
- "directory.go",
- "filesystem.go",
- "fstree.go",
- "gofer.go",
- "handle.go",
- "host_named_pipe.go",
- "p9file.go",
- "regular_file.go",
- "socket.go",
- "special_file.go",
- "symlink.go",
- "time.go",
- ],
- visibility = ["//pkg/sentry:internal"],
- deps = [
- "//pkg/abi/linux",
- "//pkg/context",
- "//pkg/fd",
- "//pkg/fdnotifier",
- "//pkg/fspath",
- "//pkg/log",
- "//pkg/p9",
- "//pkg/safemem",
- "//pkg/sentry/fs/fsutil",
- "//pkg/sentry/fs/lock",
- "//pkg/sentry/fsimpl/host",
- "//pkg/sentry/hostfd",
- "//pkg/sentry/kernel",
- "//pkg/sentry/kernel/auth",
- "//pkg/sentry/kernel/pipe",
- "//pkg/sentry/kernel/time",
- "//pkg/sentry/memmap",
- "//pkg/sentry/pgalloc",
- "//pkg/sentry/platform",
- "//pkg/sentry/socket/control",
- "//pkg/sentry/socket/unix",
- "//pkg/sentry/socket/unix/transport",
- "//pkg/sentry/usage",
- "//pkg/sentry/vfs",
- "//pkg/syserr",
- "//pkg/syserror",
- "//pkg/unet",
- "//pkg/usermem",
- "//pkg/waiter",
- "@org_golang_x_sys//unix:go_default_library",
- ],
-)
-
-go_test(
- name = "gofer_test",
- srcs = ["gofer_test.go"],
- library = ":gofer",
- deps = [
- "//pkg/p9",
- "//pkg/sentry/contexttest",
- ],
-)
diff --git a/pkg/sentry/fsimpl/gofer/dentry_list.go b/pkg/sentry/fsimpl/gofer/dentry_list.go
new file mode 100644
index 000000000..84f839e3a
--- /dev/null
+++ b/pkg/sentry/fsimpl/gofer/dentry_list.go
@@ -0,0 +1,193 @@
+package gofer
+
+// ElementMapper provides an identity mapping by default.
+//
+// This can be replaced to provide a struct that maps elements to linker
+// objects, if they are not the same. An ElementMapper is not typically
+// required if: Linker is left as is, Element is left as is, or Linker and
+// Element are the same type.
+type dentryElementMapper struct{}
+
+// linkerFor maps an Element to a Linker.
+//
+// This default implementation should be inlined.
+//
+//go:nosplit
+func (dentryElementMapper) linkerFor(elem *dentry) *dentry { return elem }
+
+// List is an intrusive list. Entries can be added to or removed from the list
+// in O(1) time and with no additional memory allocations.
+//
+// The zero value for List is an empty list ready to use.
+//
+// To iterate over a list (where l is a List):
+// for e := l.Front(); e != nil; e = e.Next() {
+// // do something with e.
+// }
+//
+// +stateify savable
+type dentryList struct {
+ head *dentry
+ tail *dentry
+}
+
+// Reset resets list l to the empty state.
+func (l *dentryList) Reset() {
+ l.head = nil
+ l.tail = nil
+}
+
+// Empty returns true iff the list is empty.
+func (l *dentryList) Empty() bool {
+ return l.head == nil
+}
+
+// Front returns the first element of list l or nil.
+func (l *dentryList) Front() *dentry {
+ return l.head
+}
+
+// Back returns the last element of list l or nil.
+func (l *dentryList) Back() *dentry {
+ return l.tail
+}
+
+// Len returns the number of elements in the list.
+//
+// NOTE: This is an O(n) operation.
+func (l *dentryList) Len() (count int) {
+ for e := l.Front(); e != nil; e = (dentryElementMapper{}.linkerFor(e)).Next() {
+ count++
+ }
+ return count
+}
+
+// PushFront inserts the element e at the front of list l.
+func (l *dentryList) PushFront(e *dentry) {
+ linker := dentryElementMapper{}.linkerFor(e)
+ linker.SetNext(l.head)
+ linker.SetPrev(nil)
+ if l.head != nil {
+ dentryElementMapper{}.linkerFor(l.head).SetPrev(e)
+ } else {
+ l.tail = e
+ }
+
+ l.head = e
+}
+
+// PushBack inserts the element e at the back of list l.
+func (l *dentryList) PushBack(e *dentry) {
+ linker := dentryElementMapper{}.linkerFor(e)
+ linker.SetNext(nil)
+ linker.SetPrev(l.tail)
+ if l.tail != nil {
+ dentryElementMapper{}.linkerFor(l.tail).SetNext(e)
+ } else {
+ l.head = e
+ }
+
+ l.tail = e
+}
+
+// PushBackList inserts list m at the end of list l, emptying m.
+func (l *dentryList) PushBackList(m *dentryList) {
+ if l.head == nil {
+ l.head = m.head
+ l.tail = m.tail
+ } else if m.head != nil {
+ dentryElementMapper{}.linkerFor(l.tail).SetNext(m.head)
+ dentryElementMapper{}.linkerFor(m.head).SetPrev(l.tail)
+
+ l.tail = m.tail
+ }
+ m.head = nil
+ m.tail = nil
+}
+
+// InsertAfter inserts e after b.
+func (l *dentryList) InsertAfter(b, e *dentry) {
+ bLinker := dentryElementMapper{}.linkerFor(b)
+ eLinker := dentryElementMapper{}.linkerFor(e)
+
+ a := bLinker.Next()
+
+ eLinker.SetNext(a)
+ eLinker.SetPrev(b)
+ bLinker.SetNext(e)
+
+ if a != nil {
+ dentryElementMapper{}.linkerFor(a).SetPrev(e)
+ } else {
+ l.tail = e
+ }
+}
+
+// InsertBefore inserts e before a.
+func (l *dentryList) InsertBefore(a, e *dentry) {
+ aLinker := dentryElementMapper{}.linkerFor(a)
+ eLinker := dentryElementMapper{}.linkerFor(e)
+
+ b := aLinker.Prev()
+ eLinker.SetNext(a)
+ eLinker.SetPrev(b)
+ aLinker.SetPrev(e)
+
+ if b != nil {
+ dentryElementMapper{}.linkerFor(b).SetNext(e)
+ } else {
+ l.head = e
+ }
+}
+
+// Remove removes e from l.
+func (l *dentryList) Remove(e *dentry) {
+ linker := dentryElementMapper{}.linkerFor(e)
+ prev := linker.Prev()
+ next := linker.Next()
+
+ if prev != nil {
+ dentryElementMapper{}.linkerFor(prev).SetNext(next)
+ } else if l.head == e {
+ l.head = next
+ }
+
+ if next != nil {
+ dentryElementMapper{}.linkerFor(next).SetPrev(prev)
+ } else if l.tail == e {
+ l.tail = prev
+ }
+
+ linker.SetNext(nil)
+ linker.SetPrev(nil)
+}
+
+// Entry is a default implementation of Linker. Users can add anonymous fields
+// of this type to their structs to make them automatically implement the
+// methods needed by List.
+//
+// +stateify savable
+type dentryEntry struct {
+ next *dentry
+ prev *dentry
+}
+
+// Next returns the entry that follows e in the list.
+func (e *dentryEntry) Next() *dentry {
+ return e.next
+}
+
+// Prev returns the entry that precedes e in the list.
+func (e *dentryEntry) Prev() *dentry {
+ return e.prev
+}
+
+// SetNext assigns 'entry' as the entry that follows e in the list.
+func (e *dentryEntry) SetNext(elem *dentry) {
+ e.next = elem
+}
+
+// SetPrev assigns 'entry' as the entry that precedes e in the list.
+func (e *dentryEntry) SetPrev(elem *dentry) {
+ e.prev = elem
+}
diff --git a/pkg/sentry/fsimpl/gofer/fstree.go b/pkg/sentry/fsimpl/gofer/fstree.go
new file mode 100644
index 000000000..507dc82e6
--- /dev/null
+++ b/pkg/sentry/fsimpl/gofer/fstree.go
@@ -0,0 +1,46 @@
+package gofer
+
+import (
+ "gvisor.dev/gvisor/pkg/fspath"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+)
+
+// IsAncestorDentry returns true if d is an ancestor of d2; that is, d is
+// either d2's parent or an ancestor of d2's parent.
+func genericIsAncestorDentry(d, d2 *dentry) bool {
+ for d2 != nil {
+ if d2.parent == d {
+ return true
+ }
+ if d2.parent == d2 {
+ return false
+ }
+ d2 = d2.parent
+ }
+ return false
+}
+
+// ParentOrSelf returns d.parent. If d.parent is nil, ParentOrSelf returns d.
+func genericParentOrSelf(d *dentry) *dentry {
+ if d.parent != nil {
+ return d.parent
+ }
+ return d
+}
+
+// PrependPath is a generic implementation of FilesystemImpl.PrependPath().
+func genericPrependPath(vfsroot vfs.VirtualDentry, mnt *vfs.Mount, d *dentry, b *fspath.Builder) error {
+ for {
+ if mnt == vfsroot.Mount() && &d.vfsd == vfsroot.Dentry() {
+ return vfs.PrependPathAtVFSRootError{}
+ }
+ if &d.vfsd == mnt.Root() {
+ return nil
+ }
+ if d.parent == nil {
+ return vfs.PrependPathAtNonMountRootError{}
+ }
+ b.PrependComponent(d.name)
+ d = d.parent
+ }
+}
diff --git a/pkg/sentry/fsimpl/gofer/gofer_state_autogen.go b/pkg/sentry/fsimpl/gofer/gofer_state_autogen.go
new file mode 100644
index 000000000..19b1eef9e
--- /dev/null
+++ b/pkg/sentry/fsimpl/gofer/gofer_state_autogen.go
@@ -0,0 +1,64 @@
+// automatically generated by stateify.
+
+package gofer
+
+import (
+ "gvisor.dev/gvisor/pkg/state"
+)
+
+func (x *dentryList) StateTypeName() string {
+ return "pkg/sentry/fsimpl/gofer.dentryList"
+}
+
+func (x *dentryList) StateFields() []string {
+ return []string{
+ "head",
+ "tail",
+ }
+}
+
+func (x *dentryList) beforeSave() {}
+
+func (x *dentryList) StateSave(m state.Sink) {
+ x.beforeSave()
+ m.Save(0, &x.head)
+ m.Save(1, &x.tail)
+}
+
+func (x *dentryList) afterLoad() {}
+
+func (x *dentryList) StateLoad(m state.Source) {
+ m.Load(0, &x.head)
+ m.Load(1, &x.tail)
+}
+
+func (x *dentryEntry) StateTypeName() string {
+ return "pkg/sentry/fsimpl/gofer.dentryEntry"
+}
+
+func (x *dentryEntry) StateFields() []string {
+ return []string{
+ "next",
+ "prev",
+ }
+}
+
+func (x *dentryEntry) beforeSave() {}
+
+func (x *dentryEntry) StateSave(m state.Sink) {
+ x.beforeSave()
+ m.Save(0, &x.next)
+ m.Save(1, &x.prev)
+}
+
+func (x *dentryEntry) afterLoad() {}
+
+func (x *dentryEntry) StateLoad(m state.Source) {
+ m.Load(0, &x.next)
+ m.Load(1, &x.prev)
+}
+
+func init() {
+ state.Register((*dentryList)(nil))
+ state.Register((*dentryEntry)(nil))
+}
diff --git a/pkg/sentry/fsimpl/gofer/gofer_test.go b/pkg/sentry/fsimpl/gofer/gofer_test.go
deleted file mode 100644
index 56d80bcf8..000000000
--- a/pkg/sentry/fsimpl/gofer/gofer_test.go
+++ /dev/null
@@ -1,63 +0,0 @@
-// Copyright 2020 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 gofer
-
-import (
- "sync/atomic"
- "testing"
-
- "gvisor.dev/gvisor/pkg/p9"
- "gvisor.dev/gvisor/pkg/sentry/contexttest"
-)
-
-func TestDestroyIdempotent(t *testing.T) {
- fs := filesystem{
- syncableDentries: make(map[*dentry]struct{}),
- opts: filesystemOptions{
- // Test relies on no dentry being held in the cache.
- maxCachedDentries: 0,
- },
- }
-
- ctx := contexttest.Context(t)
- attr := &p9.Attr{
- Mode: p9.ModeRegular,
- }
- mask := p9.AttrMask{
- Mode: true,
- Size: true,
- }
- parent, err := fs.newDentry(ctx, p9file{}, p9.QID{}, mask, attr)
- if err != nil {
- t.Fatalf("fs.newDentry(): %v", err)
- }
-
- child, err := fs.newDentry(ctx, p9file{}, p9.QID{}, mask, attr)
- if err != nil {
- t.Fatalf("fs.newDentry(): %v", err)
- }
- parent.cacheNewChildLocked(child, "child")
-
- child.checkCachingLocked(ctx)
- if got := atomic.LoadInt64(&child.refs); got != -1 {
- t.Fatalf("child.refs=%d, want: -1", got)
- }
- // Parent will also be destroyed when child reference is removed.
- if got := atomic.LoadInt64(&parent.refs); got != -1 {
- t.Fatalf("parent.refs=%d, want: -1", got)
- }
- child.checkCachingLocked(ctx)
- child.checkCachingLocked(ctx)
-}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-06 16:26:58 +0000