Remove fs.Handle, ramfs.Entry, and all the DeprecatedFileOperations.

More helper structs have been added to the fsutil package to make it easier to
implement fs.InodeOperations and fs.FileOperations.

PiperOrigin-RevId: 229305982
Change-Id: Ib6f8d3862f4216745116857913dbfa351530223b

1 files changed, 14 insertions, 15 deletions

diff --git a/pkg/sentry/fs/dev/dev.go b/pkg/sentry/fs/dev/dev.go
index 3e127bf04..f8e8099f7 100644
--- a/pkg/sentry/fs/dev/dev.go
+++ b/pkg/sentry/fs/dev/dev.go
@@ -16,6 +16,8 @@
 package dev
 
 import (
+	"math"
+
 	"gvisor.googlesource.com/gvisor/pkg/sentry/context"
 	"gvisor.googlesource.com/gvisor/pkg/sentry/fs"
 	"gvisor.googlesource.com/gvisor/pkg/sentry/fs/ashmem"
@@ -26,13 +28,6 @@ import (
 	"gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
 )
 
-// Dev is the root node.
-//
-// +stateify savable
-type Dev struct {
-	ramfs.Dir
-}
-
 func newCharacterDevice(iops fs.InodeOperations, msrc *fs.MountSource) *fs.Inode {
 	return fs.NewInode(iops, msrc, fs.StableAttr{
 		DeviceID:  devDevice.DeviceID(),
@@ -43,8 +38,7 @@ func newCharacterDevice(iops fs.InodeOperations, msrc *fs.MountSource) *fs.Inode
 }
 
 func newDirectory(ctx context.Context, msrc *fs.MountSource) *fs.Inode {
-	iops := &ramfs.Dir{}
-	iops.InitDir(ctx, map[string]*fs.Inode{}, fs.RootOwner, fs.FilePermsFromMode(0555))
+	iops := ramfs.NewDir(ctx, nil, fs.RootOwner, fs.FilePermsFromMode(0555))
 	return fs.NewInode(iops, msrc, fs.StableAttr{
 		DeviceID:  devDevice.DeviceID(),
 		InodeID:   devDevice.NextIno(),
@@ -54,8 +48,7 @@ func newDirectory(ctx context.Context, msrc *fs.MountSource) *fs.Inode {
 }
 
 func newSymlink(ctx context.Context, target string, msrc *fs.MountSource) *fs.Inode {
-	iops := &ramfs.Symlink{}
-	iops.InitSymlink(ctx, fs.RootOwner, target)
+	iops := ramfs.NewSymlink(ctx, fs.RootOwner, target)
 	return fs.NewInode(iops, msrc, fs.StableAttr{
 		DeviceID:  devDevice.DeviceID(),
 		InodeID:   devDevice.NextIno(),
@@ -66,8 +59,6 @@ func newSymlink(ctx context.Context, target string, msrc *fs.MountSource) *fs.In
 
 // New returns the root node of a device filesystem.
 func New(ctx context.Context, msrc *fs.MountSource, binderEnabled bool, ashmemEnabled bool) *fs.Inode {
-	d := &Dev{}
-
 	contents := map[string]*fs.Inode{
 		"fd":     newSymlink(ctx, "/proc/self/fd", msrc),
 		"stdin":  newSymlink(ctx, "/proc/self/fd/0", msrc),
@@ -114,11 +105,19 @@ func New(ctx context.Context, msrc *fs.MountSource, binderEnabled bool, ashmemEn
 		contents["ashmem"] = newCharacterDevice(ashmem, msrc)
 	}
 
-	d.InitDir(ctx, contents, fs.RootOwner, fs.FilePermsFromMode(0555))
-	return fs.NewInode(d, msrc, fs.StableAttr{
+	iops := ramfs.NewDir(ctx, contents, fs.RootOwner, fs.FilePermsFromMode(0555))
+	return fs.NewInode(iops, msrc, fs.StableAttr{
 		DeviceID:  devDevice.DeviceID(),
 		InodeID:   devDevice.NextIno(),
 		BlockSize: usermem.PageSize,
 		Type:      fs.Directory,
 	})
 }
+
+// readZeros implements fs.FileOperations.Read with infinite null bytes.
+type readZeros struct{}
+
+// Read implements fs.FileOperations.Read.
+func (readZeros) Read(ctx context.Context, file *fs.File, dst usermem.IOSequence, offset int64) (int64, error) {
+	return dst.ZeroOut(ctx, math.MaxInt64)
+}