Move VFS2 file description status flags to vfs.FileDescription.

PiperOrigin-RevId: 286616668

7 files changed, 10 insertions, 77 deletions

diff --git a/pkg/sentry/fsimpl/ext/file_description.go b/pkg/sentry/fsimpl/ext/file_description.go
index 5eca2b83f..841274daf 100644
--- a/pkg/sentry/fsimpl/ext/file_description.go
+++ b/pkg/sentry/fsimpl/ext/file_description.go
@@ -26,13 +26,6 @@ import (
 type fileDescription struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
-
-	// flags is the same as vfs.OpenOptions.Flags which are passed to
-	// vfs.FilesystemImpl.OpenAt.
-	// TODO(b/134676337): syscalls like read(2), write(2), fchmod(2), fchown(2),
-	// fgetxattr(2), ioctl(2), mmap(2) should fail with EBADF if O_PATH is set.
-	// Only close(2), fstat(2), fstatfs(2) should work.
-	flags uint32
 }
 
 func (fd *fileDescription) filesystem() *filesystem {
@@ -43,18 +36,6 @@ func (fd *fileDescription) inode() *inode {
 	return fd.vfsfd.Dentry().Impl().(*dentry).inode
 }
 
-// StatusFlags implements vfs.FileDescriptionImpl.StatusFlags.
-func (fd *fileDescription) StatusFlags(ctx context.Context) (uint32, error) {
-	return fd.flags, nil
-}
-
-// SetStatusFlags implements vfs.FileDescriptionImpl.SetStatusFlags.
-func (fd *fileDescription) SetStatusFlags(ctx context.Context, flags uint32) error {
-	// None of the flags settable by fcntl(F_SETFL) are supported, so this is a
-	// no-op.
-	return nil
-}
-
 // Stat implements vfs.FileDescriptionImpl.Stat.
 func (fd *fileDescription) Stat(ctx context.Context, opts vfs.StatOptions) (linux.Statx, error) {
 	var stat linux.Statx
diff --git a/pkg/sentry/fsimpl/ext/inode.go b/pkg/sentry/fsimpl/ext/inode.go
index 24249525c..b2cc826c7 100644
--- a/pkg/sentry/fsimpl/ext/inode.go
+++ b/pkg/sentry/fsimpl/ext/inode.go
@@ -157,10 +157,9 @@ func (in *inode) open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, flags uint32) (*v
 	switch in.impl.(type) {
 	case *regularFile:
 		var fd regularFileFD
-		fd.flags = flags
 		mnt.IncRef()
 		vfsd.IncRef()
-		fd.vfsfd.Init(&fd, mnt, vfsd)
+		fd.vfsfd.Init(&fd, flags, mnt, vfsd, &vfs.FileDescriptionOptions{})
 		return &fd.vfsfd, nil
 	case *directory:
 		// Can't open directories writably. This check is not necessary for a read
@@ -169,10 +168,9 @@ func (in *inode) open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, flags uint32) (*v
 			return nil, syserror.EISDIR
 		}
 		var fd directoryFD
-		fd.flags = flags
 		mnt.IncRef()
 		vfsd.IncRef()
-		fd.vfsfd.Init(&fd, mnt, vfsd)
+		fd.vfsfd.Init(&fd, flags, mnt, vfsd, &vfs.FileDescriptionOptions{})
 		return &fd.vfsfd, nil
 	case *symlink:
 		if flags&linux.O_PATH == 0 {
@@ -180,10 +178,9 @@ func (in *inode) open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, flags uint32) (*v
 			return nil, syserror.ELOOP
 		}
 		var fd symlinkFD
-		fd.flags = flags
 		mnt.IncRef()
 		vfsd.IncRef()
-		fd.vfsfd.Init(&fd, mnt, vfsd)
+		fd.vfsfd.Init(&fd, flags, mnt, vfsd, &vfs.FileDescriptionOptions{})
 		return &fd.vfsfd, nil
 	default:
 		panic(fmt.Sprintf("unknown inode type: %T", in.impl))
diff --git a/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go b/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go
index 30c06baf0..51102ce48 100644
--- a/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go
+++ b/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go
@@ -65,17 +65,15 @@ type DynamicBytesFD struct {
 
 	vfsfd vfs.FileDescription
 	inode Inode
-	flags uint32
 }
 
 // Init initializes a DynamicBytesFD.
 func (fd *DynamicBytesFD) Init(m *vfs.Mount, d *vfs.Dentry, data vfs.DynamicBytesSource, flags uint32) {
 	m.IncRef() // DecRef in vfs.FileDescription.vd.DecRef on final ref.
 	d.IncRef() // DecRef in vfs.FileDescription.vd.DecRef on final ref.
-	fd.flags = flags
 	fd.inode = d.Impl().(*Dentry).inode
 	fd.SetDataSource(data)
-	fd.vfsfd.Init(fd, m, d)
+	fd.vfsfd.Init(fd, flags, m, d, &vfs.FileDescriptionOptions{})
 }
 
 // Seek implements vfs.FileDescriptionImpl.Seek.
@@ -117,15 +115,3 @@ func (fd *DynamicBytesFD) SetStat(context.Context, vfs.SetStatOptions) error {
 	// DynamicBytesFiles are immutable.
 	return syserror.EPERM
 }
-
-// StatusFlags implements vfs.FileDescriptionImpl.StatusFlags.
-func (fd *DynamicBytesFD) StatusFlags(ctx context.Context) (uint32, error) {
-	return fd.flags, nil
-}
-
-// SetStatusFlags implements vfs.FileDescriptionImpl.SetStatusFlags.
-func (fd *DynamicBytesFD) SetStatusFlags(ctx context.Context, flags uint32) error {
-	// None of the flags settable by fcntl(F_SETFL) are supported, so this is a
-	// no-op.
-	return nil
-}
diff --git a/pkg/sentry/fsimpl/kernfs/fd_impl_util.go b/pkg/sentry/fsimpl/kernfs/fd_impl_util.go
index d6c18937a..bd402330f 100644
--- a/pkg/sentry/fsimpl/kernfs/fd_impl_util.go
+++ b/pkg/sentry/fsimpl/kernfs/fd_impl_util.go
@@ -39,7 +39,6 @@ type GenericDirectoryFD struct {
 
 	vfsfd    vfs.FileDescription
 	children *OrderedChildren
-	flags    uint32
 	off      int64
 }
 
@@ -48,8 +47,7 @@ func (fd *GenericDirectoryFD) Init(m *vfs.Mount, d *vfs.Dentry, children *Ordere
 	m.IncRef() // DecRef in vfs.FileDescription.vd.DecRef on final ref.
 	d.IncRef() // DecRef in vfs.FileDescription.vd.DecRef on final ref.
 	fd.children = children
-	fd.flags = flags
-	fd.vfsfd.Init(fd, m, d)
+	fd.vfsfd.Init(fd, flags, m, d, &vfs.FileDescriptionOptions{})
 }
 
 // VFSFileDescription returns a pointer to the vfs.FileDescription representing
@@ -180,18 +178,6 @@ func (fd *GenericDirectoryFD) Seek(ctx context.Context, offset int64, whence int
 	return offset, nil
 }
 
-// StatusFlags implements vfs.FileDescriptionImpl.StatusFlags.
-func (fd *GenericDirectoryFD) StatusFlags(ctx context.Context) (uint32, error) {
-	return fd.flags, nil
-}
-
-// SetStatusFlags implements vfs.FileDescriptionImpl.SetStatusFlags.
-func (fd *GenericDirectoryFD) SetStatusFlags(ctx context.Context, flags uint32) error {
-	// None of the flags settable by fcntl(F_SETFL) are supported, so this is a
-	// no-op.
-	return nil
-}
-
 // Stat implements vfs.FileDescriptionImpl.Stat.
 func (fd *GenericDirectoryFD) Stat(ctx context.Context, opts vfs.StatOptions) (linux.Statx, error) {
 	fs := fd.filesystem()
diff --git a/pkg/sentry/fsimpl/memfs/filesystem.go b/pkg/sentry/fsimpl/memfs/filesystem.go
index 22f1e811f..af4389459 100644
--- a/pkg/sentry/fsimpl/memfs/filesystem.go
+++ b/pkg/sentry/fsimpl/memfs/filesystem.go
@@ -282,9 +282,8 @@ func (fs *filesystem) MknodAt(ctx context.Context, rp *vfs.ResolvingPath, opts v
 func (fs *filesystem) OpenAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
 	// Filter out flags that are not supported by memfs. O_DIRECTORY and
 	// O_NOFOLLOW have no effect here (they're handled by VFS by setting
-	// appropriate bits in rp), but are returned by
-	// FileDescriptionImpl.StatusFlags(). O_NONBLOCK is supported only by
-	// pipes.
+	// appropriate bits in rp), but are visible in FD status flags. O_NONBLOCK
+	// is supported only by pipes.
 	opts.Flags &= linux.O_ACCMODE | linux.O_CREAT | linux.O_EXCL | linux.O_TRUNC | linux.O_DIRECTORY | linux.O_NOFOLLOW | linux.O_NONBLOCK
 
 	if opts.Flags&linux.O_CREAT == 0 {
@@ -384,7 +383,6 @@ func (i *inode) open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentr
 	switch impl := i.impl.(type) {
 	case *regularFile:
 		var fd regularFileFD
-		fd.flags = flags
 		fd.readable = vfs.MayReadFileWithOpenFlags(flags)
 		fd.writable = vfs.MayWriteFileWithOpenFlags(flags)
 		if fd.writable {
@@ -395,7 +393,7 @@ func (i *inode) open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentr
 		}
 		mnt.IncRef()
 		vfsd.IncRef()
-		fd.vfsfd.Init(&fd, mnt, vfsd)
+		fd.vfsfd.Init(&fd, flags, mnt, vfsd, &vfs.FileDescriptionOptions{})
 		if flags&linux.O_TRUNC != 0 {
 			impl.mu.Lock()
 			impl.data = impl.data[:0]
@@ -411,8 +409,7 @@ func (i *inode) open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentr
 		var fd directoryFD
 		mnt.IncRef()
 		vfsd.IncRef()
-		fd.vfsfd.Init(&fd, mnt, vfsd)
-		fd.flags = flags
+		fd.vfsfd.Init(&fd, flags, mnt, vfsd, &vfs.FileDescriptionOptions{})
 		return &fd.vfsfd, nil
 	case *symlink:
 		// Can't open symlinks without O_PATH (which is unimplemented).
diff --git a/pkg/sentry/fsimpl/memfs/memfs.go b/pkg/sentry/fsimpl/memfs/memfs.go
index 4cb2a4e0f..9d509f6e4 100644
--- a/pkg/sentry/fsimpl/memfs/memfs.go
+++ b/pkg/sentry/fsimpl/memfs/memfs.go
@@ -261,8 +261,6 @@ func (i *inode) direntType() uint8 {
 type fileDescription struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
-
-	flags uint32 // status flags; immutable
 }
 
 func (fd *fileDescription) filesystem() *filesystem {
@@ -273,18 +271,6 @@ func (fd *fileDescription) inode() *inode {
 	return fd.vfsfd.Dentry().Impl().(*dentry).inode
 }
 
-// StatusFlags implements vfs.FileDescriptionImpl.StatusFlags.
-func (fd *fileDescription) StatusFlags(ctx context.Context) (uint32, error) {
-	return fd.flags, nil
-}
-
-// SetStatusFlags implements vfs.FileDescriptionImpl.SetStatusFlags.
-func (fd *fileDescription) SetStatusFlags(ctx context.Context, flags uint32) error {
-	// None of the flags settable by fcntl(F_SETFL) are supported, so this is a
-	// no-op.
-	return nil
-}
-
 // Stat implements vfs.FileDescriptionImpl.Stat.
 func (fd *fileDescription) Stat(ctx context.Context, opts vfs.StatOptions) (linux.Statx, error) {
 	var stat linux.Statx
diff --git a/pkg/sentry/fsimpl/memfs/named_pipe.go b/pkg/sentry/fsimpl/memfs/named_pipe.go
index 91cb4b1fc..d5060850e 100644
--- a/pkg/sentry/fsimpl/memfs/named_pipe.go
+++ b/pkg/sentry/fsimpl/memfs/named_pipe.go
@@ -57,6 +57,6 @@ func newNamedPipeFD(ctx context.Context, np *namedPipe, rp *vfs.ResolvingPath, v
 	mnt := rp.Mount()
 	mnt.IncRef()
 	vfsd.IncRef()
-	fd.vfsfd.Init(&fd, mnt, vfsd)
+	fd.vfsfd.Init(&fd, flags, mnt, vfsd, &vfs.FileDescriptionOptions{})
 	return &fd.vfsfd, nil
 }