Able to compile imgfs

Author: E4242

pkg/sentry/fs/imgfs/file.go

@@ -15,6 +15,7 @@
 package imgfs
 
 import (
+	"io"
 	"gvisor.dev/gvisor/pkg/sentry/context"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
@@ -28,13 +29,16 @@ import (
 //
 // +stateify savable
 type regularFileOperations struct {
-	waiter.AlwaysReady       `state:"nosave"`
-	fsutil.FileNoopRelease   `state:"nosave"`
-	fsutil.FileGenericSeek   `state:"nosave"`
-	fsutil.FileNotDirReaddir `state:"nosave"`
-	fsutil.FileNoopFsync     `state:"nosave"`
-	fsutil.FileNoopFlush     `state:"nosave"`
-	fsutil.FileNoIoctl       `state:"nosave"`
+	
+	fsutil.FileNoopRelease          `state:"nosave"`
+	fsutil.FileGenericSeek          `state:"nosave"`
+	fsutil.FileNotDirReaddir        `state:"nosave"`
+	fsutil.FileNoopFsync            `state:"nosave"`
+	fsutil.FileNoopFlush            `state:"nosave"`
+	fsutil.FileNoIoctl              `state:"nosave"`
+	fsutil.FileNoSplice             `state:"nosave"`
+	fsutil.FileUseInodeUnstableAttr `state:"nosave"`
+	waiter.AlwaysReady              `state:"nosave"`
 
 	// iops is the InodeOperations of a regular tmpfs file. It is
 	// guaranteed to be the same as file.Dirent.Inode.InodeOperations,
@@ -56,3 +60,8 @@ func (r *regularFileOperations) Write(ctx context.Context, file *fs.File, src us
 func (r *regularFileOperations) ConfigureMMap(ctx context.Context, file *fs.File, opts *memmap.MMapOpts) error {
 	return fsutil.GenericConfigureMMap(file, r.iops, opts)
 }
+
+// ReadFrom implements fs.FileOperations.ReadFrom.
+func (r *regularFileOperations) ReadFrom(context.Context, *fs.File, io.Reader, int64) (int64, error) {
+	return 0, syserror.ENOSYS
+}

pkg/sentry/fs/imgfs/fs.go

@@ -31,6 +31,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/fs/ramfs"
 	"gvisor.dev/gvisor/pkg/log"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	
 )
 
 // FilesystemName is the name under which Filesystem is registered.
@@ -121,7 +122,7 @@ func (f *Filesystem) Mount(ctx context.Context, _ string, flags fs.MountSourceFl
 	}
 
 	// Construct img file system mount and inode.
-	msrc := fs.NewCachingMountSource(f, flags)
+	msrc := fs.NewCachingMountSource(ctx, f, flags)
 
 	var s syscall.Stat_t
 	err := syscall.Fstat(int(f.packageFD), &s)
@@ -199,15 +200,15 @@ func MountImgRecursive(ctx context.Context, msrc *fs.MountSource, metadata []fil
 		}
 	}
 	d := ramfs.NewDir(ctx, contents, fs.RootOwner, fs.FilePermsFromMode(linux.FileMode(dirMode)))
-	newinode := fs.NewInode(d, msrc, fs.StableAttr{
+	newinode := fs.NewInode(ctx, d, msrc, fs.StableAttr{
 		DeviceID:  imgfsFileDevice.DeviceID(),
 		InodeID:   imgfsFileDevice.NextIno(),
 		BlockSize: usermem.PageSize,
 		Type:      fs.Directory,
 	})
 
 	for _, fn := range whitoutFiles {
-		newinode.InodeOperations.Setxattr(newinode, fs.XattrOverlayWhiteout(fn), []byte("y"))
+		newinode.InodeOperations.Setxattr(newinode, fs.XattrOverlayWhiteout(fn), string([]byte("y")))
 	}
 	return newinode, nil
 }

pkg/sentry/fs/imgfs/inode.go

@@ -18,8 +18,10 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"sync"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/log"
 	"gvisor.dev/gvisor/pkg/sentry/context"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
@@ -29,6 +31,8 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/safemem"
 	"gvisor.dev/gvisor/pkg/sentry/usermem"
 	"gvisor.dev/gvisor/pkg/syserror"
+	"gvisor.dev/gvisor/pkg/sentry/kernel"
+	"gvisor.dev/gvisor/pkg/sentry/usage"
 )
 // inodeOperations implements fs.InodeOperations for an fs.Inodes backed
 // by a host file descriptor.
@@ -41,6 +45,7 @@ type fileInodeOperations struct {
 	fsutil.InodeNotSocket      `state:"nosave"`
 	fsutil.InodeNotSymlink     `state:"nosave"`
 
+
 	fsutil.InodeSimpleExtendedAttributes
 
 	attr fs.UnstableAttr
@@ -52,6 +57,40 @@ type fileInodeOperations struct {
 	offsetEnd int64
 
 	packageFD int
+
+	// kernel is used to allocate memory that stores the file's contents.
+	kernel *kernel.Kernel
+
+	// memUsage is the default memory usage that will be reported by this file.
+	memUsage usage.MemoryKind
+
+	attrMu sync.Mutex `state:"nosave"`
+
+	mapsMu sync.Mutex `state:"nosave"`
+
+	// writableMappingPages tracks how many pages of virtual memory are mapped
+	// as potentially writable from this file. If a page has multiple mappings,
+	// each mapping is counted separately.
+	//
+	// This counter is susceptible to overflow as we can potentially count
+	// mappings from many VMAs. We count pages rather than bytes to slightly
+	// mitigate this.
+	//
+	// Protected by mapsMu.
+	writableMappingPages uint64
+
+	dataMu sync.RWMutex `state:"nosave"`
+
+	// data maps offsets into the file to offsets into platform.Memory() that
+	// store the file's data.
+	//
+	// data is protected by dataMu.
+	data fsutil.FileRangeSet
+
+	// seals represents file seals on this inode.
+	//
+	// Protected by dataMu.
+	seals uint32
 }
 
 type Symlink struct {
@@ -96,8 +135,14 @@ func (f *fileInodeOperations) Mappable(*fs.Inode) memmap.Mappable {
 }
 
 // Rename implements fs.InodeOperations.Rename.
-func (*fileInodeOperations) Rename(ctx context.Context, oldParent *fs.Inode, oldName string, newParent *fs.Inode, newName string, replacement bool) error {
-	return syserror.EPERM
+func (*fileInodeOperations) Rename(ctx context.Context, inode *fs.Inode, oldParent *fs.Inode, oldName string, newParent *fs.Inode, newName string, replacement bool) error {
+	return rename(ctx, oldParent, oldName, newParent, newName, replacement)
+}
+
+// rename implements fs.InodeOperations.Rename for tmpfs nodes.
+func rename(ctx context.Context, oldParent *fs.Inode, oldName string, newParent *fs.Inode, newName string, replacement bool) error {
+	log.Infof("Called rename, not supported in imgfs")
+	return syserror.EXDEV
 }
 
 // GetFile implements fs.InodeOperations.GetFile.
@@ -239,6 +284,12 @@ func (f *fileInodeOperations) MapInternal(fr platform.FileRange, at usermem.Acce
 	return seq, nil
 }
 
+// Allocate implements fs.InodeOperations.Allocate.
+func (f *fileInodeOperations) Allocate(ctx context.Context, _ *fs.Inode, offset, length int64) error {
+	log.Infof("Calling unimplemented method in imgfs")
+	return nil
+}
+
 // Translate implements memmap.Mappable.Translate.
 func (f *fileInodeOperations) Translate(ctx context.Context, required, optional memmap.MappableRange, at usermem.AccessType) ([]memmap.Translation, error) {
 	return []memmap.Translation{
@@ -267,13 +318,13 @@ func newInode(ctx context.Context, msrc *fs.MountSource, begin int64, end int64,
 		offsetEnd:		end,
 		packageFD:    packageFD,
 	}
-	return fs.NewInode(iops, msrc, sattr), nil
+	return fs.NewInode(ctx, iops, msrc, sattr), nil
 }
 
 // newSymlink returns a new fs.Inode
 func newSymlink(ctx context.Context, msrc *fs.MountSource, target string) *fs.Inode {
 	s := &Symlink{Symlink: *ramfs.NewSymlink(ctx, fs.RootOwner, target)}
-	return fs.NewInode(s, msrc, fs.StableAttr{
+	return fs.NewInode(ctx, s, msrc, fs.StableAttr{
 		DeviceID:  imgfsFileDevice.DeviceID(),
 		InodeID:   imgfsFileDevice.NextIno(),
 		BlockSize: usermem.PageSize,