From dc8450b5676d4c4ac9bcfa23cabd862e0060527d Mon Sep 17 00:00:00 2001 From: Nicolas Lacasse Date: Mon, 14 Jan 2019 20:33:29 -0800 Subject: 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 --- pkg/sentry/fs/dev/BUILD | 1 + pkg/sentry/fs/dev/dev.go | 29 ++++++++------- pkg/sentry/fs/dev/fs.go | 2 ++ pkg/sentry/fs/dev/full.go | 55 +++++++++++++++++++--------- pkg/sentry/fs/dev/null.go | 88 +++++++++++++++++++++++++++++---------------- pkg/sentry/fs/dev/random.go | 55 +++++++++++++++++++--------- 6 files changed, 151 insertions(+), 79 deletions(-) (limited to 'pkg/sentry/fs/dev') diff --git a/pkg/sentry/fs/dev/BUILD b/pkg/sentry/fs/dev/BUILD index b17b5202c..b9cfae05f 100644 --- a/pkg/sentry/fs/dev/BUILD +++ b/pkg/sentry/fs/dev/BUILD @@ -32,5 +32,6 @@ go_library( "//pkg/sentry/safemem", "//pkg/sentry/usermem", "//pkg/syserror", + "//pkg/waiter", ], ) 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) +} diff --git a/pkg/sentry/fs/dev/fs.go b/pkg/sentry/fs/dev/fs.go index d96f4f423..abfe689f0 100644 --- a/pkg/sentry/fs/dev/fs.go +++ b/pkg/sentry/fs/dev/fs.go @@ -33,6 +33,8 @@ const ashmemEnabledKey = "ashmem_enabled" // +stateify savable type filesystem struct{} +var _ fs.Filesystem = (*filesystem)(nil) + func init() { fs.RegisterFilesystem(&filesystem{}) } diff --git a/pkg/sentry/fs/dev/full.go b/pkg/sentry/fs/dev/full.go index eeda646ab..cbdd40161 100644 --- a/pkg/sentry/fs/dev/full.go +++ b/pkg/sentry/fs/dev/full.go @@ -15,41 +15,64 @@ package dev import ( - "math" - "gvisor.googlesource.com/gvisor/pkg/abi/linux" "gvisor.googlesource.com/gvisor/pkg/sentry/context" "gvisor.googlesource.com/gvisor/pkg/sentry/fs" - "gvisor.googlesource.com/gvisor/pkg/sentry/fs/ramfs" + "gvisor.googlesource.com/gvisor/pkg/sentry/fs/fsutil" "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" "gvisor.googlesource.com/gvisor/pkg/syserror" + "gvisor.googlesource.com/gvisor/pkg/waiter" ) // fullDevice is used to implement /dev/full. // // +stateify savable type fullDevice struct { - ramfs.Entry + fsutil.InodeGenericChecker `state:"nosave"` + fsutil.InodeNoExtendedAttributes `state:"nosave"` + fsutil.InodeNoopRelease `state:"nosave"` + fsutil.InodeNoopTruncate `state:"nosave"` + fsutil.InodeNoopWriteOut `state:"nosave"` + fsutil.InodeNotDirectory `state:"nosave"` + fsutil.InodeNotMappable `state:"nosave"` + fsutil.InodeNotSocket `state:"nosave"` + fsutil.InodeNotSymlink `state:"nosave"` + fsutil.InodeVirtual `state:"nosave"` + + fsutil.InodeSimpleAttributes } +var _ fs.InodeOperations = (*fullDevice)(nil) + func newFullDevice(ctx context.Context, owner fs.FileOwner, mode linux.FileMode) *fullDevice { - f := &fullDevice{} - f.InitEntry(ctx, owner, fs.FilePermsFromMode(mode)) + f := &fullDevice{ + InodeSimpleAttributes: fsutil.NewInodeSimpleAttributes(ctx, owner, fs.FilePermsFromMode(mode), linux.TMPFS_MAGIC), + } return f } -// DeprecatedPwritev implements fs.InodeOperations.DeprecatedPwritev by -// returining ENOSPC. -func (f *fullDevice) DeprecatedPwritev(_ context.Context, _ usermem.IOSequence, _ int64) (int64, error) { - return 0, syserror.ENOSPC +// GetFile implements fs.InodeOperations.GetFile. +func (f *fullDevice) GetFile(ctx context.Context, dirent *fs.Dirent, flags fs.FileFlags) (*fs.File, error) { + flags.Pread = true + return fs.NewFile(ctx, dirent, flags, &fullFileOperations{}), nil } -// DeprecatedPreadv implements fs.InodeOperations.DeprecatedPreadv. -func (f *fullDevice) DeprecatedPreadv(ctx context.Context, dst usermem.IOSequence, _ int64) (int64, error) { - return dst.ZeroOut(ctx, math.MaxInt64) +// +stateify savable +type fullFileOperations struct { + waiter.AlwaysReady `state:"nosave"` + fsutil.FileGenericSeek `state:"nosave"` + fsutil.FileNoIoctl `state:"nosave"` + fsutil.FileNoMMap `state:"nosave"` + fsutil.FileNoopFlush `state:"nosave"` + fsutil.FileNoopFsync `state:"nosave"` + fsutil.FileNoopRelease `state:"nosave"` + fsutil.FileNotDirReaddir `state:"nosave"` + readZeros `state:"nosave"` } -// Truncate should be simply ignored for character devices on linux. -func (f *fullDevice) Truncate(context.Context, *fs.Inode, int64) error { - return nil +var _ fs.FileOperations = (*fullFileOperations)(nil) + +// Write implements FileOperations.Write. +func (fullFileOperations) Write(context.Context, *fs.File, usermem.IOSequence, int64) (int64, error) { + return 0, syserror.ENOSPC } diff --git a/pkg/sentry/fs/dev/null.go b/pkg/sentry/fs/dev/null.go index 68090f353..73fd09058 100644 --- a/pkg/sentry/fs/dev/null.go +++ b/pkg/sentry/fs/dev/null.go @@ -15,78 +15,104 @@ package dev import ( - "io" - "math" - "gvisor.googlesource.com/gvisor/pkg/abi/linux" "gvisor.googlesource.com/gvisor/pkg/sentry/context" "gvisor.googlesource.com/gvisor/pkg/sentry/fs" "gvisor.googlesource.com/gvisor/pkg/sentry/fs/fsutil" - "gvisor.googlesource.com/gvisor/pkg/sentry/fs/ramfs" "gvisor.googlesource.com/gvisor/pkg/sentry/memmap" "gvisor.googlesource.com/gvisor/pkg/sentry/mm" "gvisor.googlesource.com/gvisor/pkg/sentry/platform" - "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" + "gvisor.googlesource.com/gvisor/pkg/waiter" ) // +stateify savable type nullDevice struct { - ramfs.Entry + fsutil.InodeGenericChecker `state:"nosave"` + fsutil.InodeNoExtendedAttributes `state:"nosave"` + fsutil.InodeNoopRelease `state:"nosave"` + fsutil.InodeNoopTruncate `state:"nosave"` + fsutil.InodeNoopWriteOut `state:"nosave"` + fsutil.InodeNotDirectory `state:"nosave"` + fsutil.InodeNotMappable `state:"nosave"` + fsutil.InodeNotSocket `state:"nosave"` + fsutil.InodeNotSymlink `state:"nosave"` + fsutil.InodeVirtual `state:"nosave"` + + fsutil.InodeSimpleAttributes } +var _ fs.InodeOperations = (*nullDevice)(nil) + func newNullDevice(ctx context.Context, owner fs.FileOwner, mode linux.FileMode) *nullDevice { - n := &nullDevice{} - n.InitEntry(ctx, owner, fs.FilePermsFromMode(mode)) + n := &nullDevice{ + InodeSimpleAttributes: fsutil.NewInodeSimpleAttributes(ctx, owner, fs.FilePermsFromMode(mode), linux.TMPFS_MAGIC), + } return n } -// DeprecatedPreadv reads data from the device. -func (n *nullDevice) DeprecatedPreadv(ctx context.Context, dst usermem.IOSequence, offset int64) (int64, error) { - return 0, io.EOF -} +// GetFile implements fs.FileOperations.GetFile. +func (n *nullDevice) GetFile(ctx context.Context, dirent *fs.Dirent, flags fs.FileFlags) (*fs.File, error) { + flags.Pread = true + flags.Pwrite = true -// DeprecatedPwritev discards writes. -func (n *nullDevice) DeprecatedPwritev(_ context.Context, src usermem.IOSequence, offset int64) (int64, error) { - return src.NumBytes(), nil + return fs.NewFile(ctx, dirent, flags, &nullFileOperations{}), nil } -// Truncate should be simply ignored for character devices on linux. -func (n *nullDevice) Truncate(context.Context, *fs.Inode, int64) error { - return nil +// +stateify savable +type nullFileOperations struct { + waiter.AlwaysReady `state:"nosave"` + fsutil.FileGenericSeek `state:"nosave"` + fsutil.FileNoIoctl `state:"nosave"` + fsutil.FileNoMMap `state:"nosave"` + fsutil.FileNoopFlush `state:"nosave"` + fsutil.FileNoopFsync `state:"nosave"` + fsutil.FileNoopRead `state:"nosave"` + fsutil.FileNoopWrite `state:"nosave"` + fsutil.FileNoopRelease `state:"nosave"` + fsutil.FileNotDirReaddir `state:"nosave"` } +var _ fs.FileOperations = (*nullFileOperations)(nil) + // +stateify savable type zeroDevice struct { nullDevice } +var _ fs.InodeOperations = (*zeroDevice)(nil) + func newZeroDevice(ctx context.Context, owner fs.FileOwner, mode linux.FileMode) *zeroDevice { - zd := &zeroDevice{} - zd.InitEntry(ctx, owner, fs.FilePermsFromMode(mode)) + zd := &zeroDevice{ + nullDevice: nullDevice{ + InodeSimpleAttributes: fsutil.NewInodeSimpleAttributes(ctx, owner, fs.FilePermsFromMode(mode), linux.TMPFS_MAGIC), + }, + } return zd } -// DeprecatedPreadv implements fs.InodeOperations.DeprecatedPreadv. -func (zd *zeroDevice) DeprecatedPreadv(ctx context.Context, dst usermem.IOSequence, offset int64) (int64, error) { - return dst.ZeroOut(ctx, math.MaxInt64) -} - -// GetFile overrides ramfs.Entry.GetFile and returns a zeroFile instead. +// GetFile implements fs.FileOperations.GetFile. func (zd *zeroDevice) GetFile(ctx context.Context, dirent *fs.Dirent, flags fs.FileFlags) (*fs.File, error) { - // Allow pread(2) and pwrite(2) on this file. flags.Pread = true flags.Pwrite = true - return fs.NewFile(ctx, dirent, flags, &zeroFileOperations{ - FileOperations: &fsutil.Handle{HandleOperations: dirent.Inode.HandleOps()}, - }), nil + return fs.NewFile(ctx, dirent, flags, &zeroFileOperations{}), nil } // +stateify savable type zeroFileOperations struct { - fs.FileOperations + waiter.AlwaysReady `state:"nosave"` + fsutil.FileGenericSeek `state:"nosave"` + fsutil.FileNoopFlush `state:"nosave"` + fsutil.FileNoopFsync `state:"nosave"` + fsutil.FileNoopRelease `state:"nosave"` + fsutil.FileNoopWrite `state:"nosave"` + fsutil.FileNotDirReaddir `state:"nosave"` + fsutil.FileNoIoctl `state:"nosave"` + readZeros `state:"nosave"` } +var _ fs.FileOperations = (*zeroFileOperations)(nil) + // ConfigureMMap implements fs.FileOperations.ConfigureMMap. func (*zeroFileOperations) ConfigureMMap(ctx context.Context, file *fs.File, opts *memmap.MMapOpts) error { m, err := mm.NewSharedAnonMappable(opts.Length, platform.FromContext(ctx)) diff --git a/pkg/sentry/fs/dev/random.go b/pkg/sentry/fs/dev/random.go index 33e4913e4..837b7793a 100644 --- a/pkg/sentry/fs/dev/random.go +++ b/pkg/sentry/fs/dev/random.go @@ -19,37 +19,58 @@ import ( "gvisor.googlesource.com/gvisor/pkg/rand" "gvisor.googlesource.com/gvisor/pkg/sentry/context" "gvisor.googlesource.com/gvisor/pkg/sentry/fs" - "gvisor.googlesource.com/gvisor/pkg/sentry/fs/ramfs" + "gvisor.googlesource.com/gvisor/pkg/sentry/fs/fsutil" "gvisor.googlesource.com/gvisor/pkg/sentry/safemem" "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" + "gvisor.googlesource.com/gvisor/pkg/waiter" ) // +stateify savable type randomDevice struct { - ramfs.Entry + fsutil.InodeGenericChecker `state:"nosave"` + fsutil.InodeNoExtendedAttributes `state:"nosave"` + fsutil.InodeNoopRelease `state:"nosave"` + fsutil.InodeNoopTruncate `state:"nosave"` + fsutil.InodeNoopWriteOut `state:"nosave"` + fsutil.InodeNotDirectory `state:"nosave"` + fsutil.InodeNotMappable `state:"nosave"` + fsutil.InodeNotSocket `state:"nosave"` + fsutil.InodeNotSymlink `state:"nosave"` + fsutil.InodeVirtual `state:"nosave"` + + fsutil.InodeSimpleAttributes } +var _ fs.InodeOperations = (*randomDevice)(nil) + func newRandomDevice(ctx context.Context, owner fs.FileOwner, mode linux.FileMode) *randomDevice { - r := &randomDevice{} - r.InitEntry(ctx, owner, fs.FilePermsFromMode(mode)) + r := &randomDevice{ + InodeSimpleAttributes: fsutil.NewInodeSimpleAttributes(ctx, owner, fs.FilePermsFromMode(mode), linux.TMPFS_MAGIC), + } return r } -// DeprecatedPreadv reads random data. -func (*randomDevice) DeprecatedPreadv(ctx context.Context, dst usermem.IOSequence, offset int64) (int64, error) { - return dst.CopyOutFrom(ctx, safemem.FromIOReader{rand.Reader}) +// GetFile implements fs.InodeOperations.GetFile. +func (randomDevice) GetFile(ctx context.Context, dirent *fs.Dirent, flags fs.FileFlags) (*fs.File, error) { + return fs.NewFile(ctx, dirent, flags, &randomFileOperations{}), nil } -// DeprecatedPwritev implements fs.HandleOperations.DeprecatedPwritev. -func (*randomDevice) DeprecatedPwritev(ctx context.Context, src usermem.IOSequence, offset int64) (int64, error) { - // On Linux, "Writing to /dev/random or /dev/urandom will update the - // entropy pool with the data written, but this will not result in a higher - // entropy count" - random(4). We don't need to support this, but we do - // need to support the write, so just make it a no-op a la /dev/null. - return src.NumBytes(), nil +// +stateify savable +type randomFileOperations struct { + waiter.AlwaysReady `state:"nosave"` + fsutil.FileGenericSeek `state:"nosave"` + fsutil.FileNotDirReaddir `state:"nosave"` + fsutil.FileNoMMap `state:"nosave"` + fsutil.FileNoopFsync `state:"nosave"` + fsutil.FileNoopFlush `state:"nosave"` + fsutil.FileNoIoctl `state:"nosave"` + fsutil.FileNoopRelease `state:"nosave"` + fsutil.FileNoopWrite `state:"nosave"` } -// Truncate should be simply ignored for character devices on linux. -func (r *randomDevice) Truncate(context.Context, *fs.Inode, int64) error { - return nil +var _ fs.FileOperations = (*randomFileOperations)(nil) + +// Read implements fs.FileOperations.Read. +func (randomFileOperations) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequence, _ int64) (int64, error) { + return dst.CopyOutFrom(ctx, safemem.FromIOReader{rand.Reader}) } -- cgit v1.2.3