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-rw-r--r--pkg/sentry/fs/ext/BUILD20
-rw-r--r--pkg/sentry/fs/ext/dentry.go24
-rw-r--r--pkg/sentry/fs/ext/disklayout/dirent_old.go3
-rw-r--r--pkg/sentry/fs/ext/disklayout/superblock_32.go3
-rw-r--r--pkg/sentry/fs/ext/disklayout/superblock_64.go3
-rw-r--r--pkg/sentry/fs/ext/disklayout/superblock_old.go2
-rw-r--r--pkg/sentry/fs/ext/ext.go70
-rw-r--r--pkg/sentry/fs/ext/ext_test.go322
8 files changed, 432 insertions, 15 deletions
diff --git a/pkg/sentry/fs/ext/BUILD b/pkg/sentry/fs/ext/BUILD
index 3ba278e08..7028b3f78 100644
--- a/pkg/sentry/fs/ext/BUILD
+++ b/pkg/sentry/fs/ext/BUILD
@@ -15,7 +15,10 @@ go_library(
deps = [
"//pkg/abi/linux",
"//pkg/binary",
+ "//pkg/sentry/context",
"//pkg/sentry/fs/ext/disklayout",
+ "//pkg/sentry/kernel/auth",
+ "//pkg/sentry/vfs",
"//pkg/syserror",
],
)
@@ -23,11 +26,26 @@ go_library(
go_test(
name = "ext_test",
size = "small",
- srcs = ["extent_test.go"],
+ srcs = [
+ "ext_test.go",
+ "extent_test.go",
+ ],
+ data = [
+ "//pkg/sentry/fs/ext:assets/bigfile.txt",
+ "//pkg/sentry/fs/ext:assets/file.txt",
+ "//pkg/sentry/fs/ext:assets/tiny.ext2",
+ "//pkg/sentry/fs/ext:assets/tiny.ext3",
+ "//pkg/sentry/fs/ext:assets/tiny.ext4",
+ ],
embed = [":ext"],
deps = [
+ "//pkg/abi/linux",
"//pkg/binary",
+ "//pkg/sentry/context",
+ "//pkg/sentry/context/contexttest",
"//pkg/sentry/fs/ext/disklayout",
+ "//pkg/sentry/vfs",
+ "//runsc/test/testutil",
"@com_github_google_go-cmp//cmp:go_default_library",
"@com_github_google_go-cmp//cmp/cmpopts:go_default_library",
],
diff --git a/pkg/sentry/fs/ext/dentry.go b/pkg/sentry/fs/ext/dentry.go
index 71cd217df..07be99a84 100644
--- a/pkg/sentry/fs/ext/dentry.go
+++ b/pkg/sentry/fs/ext/dentry.go
@@ -14,10 +14,34 @@
package ext
+import (
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+)
+
// dentry implements vfs.DentryImpl.
type dentry struct {
+ vfsd vfs.Dentry
+
// inode is the inode represented by this dentry. Multiple Dentries may
// share a single non-directory Inode (with hard links). inode is
// immutable.
inode *inode
}
+
+// Compiles only if dentry implements vfs.DentryImpl.
+var _ vfs.DentryImpl = (*dentry)(nil)
+
+// IncRef implements vfs.DentryImpl.IncRef.
+func (d *dentry) IncRef(vfsfs *vfs.Filesystem) {
+ d.inode.incRef()
+}
+
+// TryIncRef implements vfs.DentryImpl.TryIncRef.
+func (d *dentry) TryIncRef(vfsfs *vfs.Filesystem) bool {
+ return d.inode.tryIncRef()
+}
+
+// DecRef implements vfs.DentryImpl.DecRef.
+func (d *dentry) DecRef(vfsfs *vfs.Filesystem) {
+ d.inode.decRef(vfsfs.Impl().(*filesystem))
+}
diff --git a/pkg/sentry/fs/ext/disklayout/dirent_old.go b/pkg/sentry/fs/ext/disklayout/dirent_old.go
index 2e0f9c812..6fff12a6e 100644
--- a/pkg/sentry/fs/ext/disklayout/dirent_old.go
+++ b/pkg/sentry/fs/ext/disklayout/dirent_old.go
@@ -17,8 +17,7 @@ package disklayout
import "gvisor.dev/gvisor/pkg/sentry/fs"
// DirentOld represents the old directory entry struct which does not contain
-// the file type. This emulates Linux's ext4_dir_entry struct. This is used in
-// ext2, ext3 and sometimes in ext4.
+// the file type. This emulates Linux's ext4_dir_entry struct.
//
// Note: This struct can be of variable size on disk. The one described below
// is of maximum size and the FileName beyond NameLength bytes might contain
diff --git a/pkg/sentry/fs/ext/disklayout/superblock_32.go b/pkg/sentry/fs/ext/disklayout/superblock_32.go
index 587e4afaa..53e515fd3 100644
--- a/pkg/sentry/fs/ext/disklayout/superblock_32.go
+++ b/pkg/sentry/fs/ext/disklayout/superblock_32.go
@@ -15,7 +15,8 @@
package disklayout
// SuperBlock32Bit implements SuperBlock and represents the 32-bit version of
-// the ext4_super_block struct in fs/ext4/ext4.h.
+// the ext4_super_block struct in fs/ext4/ext4.h. Should be used only if
+// RevLevel = DynamicRev and 64-bit feature is disabled.
type SuperBlock32Bit struct {
// We embed the old superblock struct here because the 32-bit version is just
// an extension of the old version.
diff --git a/pkg/sentry/fs/ext/disklayout/superblock_64.go b/pkg/sentry/fs/ext/disklayout/superblock_64.go
index a2c2278fb..7c1053fb4 100644
--- a/pkg/sentry/fs/ext/disklayout/superblock_64.go
+++ b/pkg/sentry/fs/ext/disklayout/superblock_64.go
@@ -17,7 +17,8 @@ package disklayout
// SuperBlock64Bit implements SuperBlock and represents the 64-bit version of
// the ext4_super_block struct in fs/ext4/ext4.h. This sums up to be exactly
// 1024 bytes (smallest possible block size) and hence the superblock always
-// fits in no more than one data block.
+// fits in no more than one data block. Should only be used when the 64-bit
+// feature is set.
type SuperBlock64Bit struct {
// We embed the 32-bit struct here because 64-bit version is just an extension
// of the 32-bit version.
diff --git a/pkg/sentry/fs/ext/disklayout/superblock_old.go b/pkg/sentry/fs/ext/disklayout/superblock_old.go
index 5a64aaaa1..9221e0251 100644
--- a/pkg/sentry/fs/ext/disklayout/superblock_old.go
+++ b/pkg/sentry/fs/ext/disklayout/superblock_old.go
@@ -15,7 +15,7 @@
package disklayout
// SuperBlockOld implements SuperBlock and represents the old version of the
-// superblock struct in ext2 and ext3 systems.
+// superblock struct. Should be used only if RevLevel = OldRev.
type SuperBlockOld struct {
InodesCountRaw uint32
BlocksCountLo uint32
diff --git a/pkg/sentry/fs/ext/ext.go b/pkg/sentry/fs/ext/ext.go
index 7f4287b01..c8b554f4d 100644
--- a/pkg/sentry/fs/ext/ext.go
+++ b/pkg/sentry/fs/ext/ext.go
@@ -16,17 +16,34 @@
package ext
import (
+ "errors"
+ "fmt"
"io"
+ "os"
"sync"
"gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/sentry/context"
"gvisor.dev/gvisor/pkg/sentry/fs/ext/disklayout"
+ "gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
"gvisor.dev/gvisor/pkg/syserror"
)
+// filesystemType implements vfs.FilesystemType.
+type filesystemType struct{}
+
+// Compiles only if filesystemType implements vfs.FilesystemType.
+var _ vfs.FilesystemType = (*filesystemType)(nil)
+
// filesystem implements vfs.FilesystemImpl.
type filesystem struct {
- // mu serializes changes to the Dentry tree and the usage of the read seeker.
+ // TODO(b/134676337): Remove when all methods have been implemented.
+ vfs.FilesystemImpl
+
+ vfsfs vfs.Filesystem
+
+ // mu serializes changes to the dentry tree and the usage of the read seeker.
mu sync.Mutex
// dev is the ReadSeeker for the underlying fs device. It is protected by mu.
@@ -58,28 +75,63 @@ type filesystem struct {
bgs []disklayout.BlockGroup
}
-// newFilesystem is the filesystem constructor.
-func newFilesystem(dev io.ReadSeeker) (*filesystem, error) {
- fs := filesystem{dev: dev, inodeCache: make(map[uint32]*inode)}
- var err error
+// Compiles only if filesystem implements vfs.FilesystemImpl.
+var _ vfs.FilesystemImpl = (*filesystem)(nil)
+
+// getDeviceFd returns the read seeker to the underlying device.
+// Currently there are two ways of mounting an ext(2/3/4) fs:
+// 1. Specify a mount with our internal special MountType in the OCI spec.
+// 2. Expose the device to the container and mount it from application layer.
+func getDeviceFd(source string, opts vfs.NewFilesystemOptions) (io.ReadSeeker, error) {
+ if opts.InternalData == nil {
+ // User mount call.
+ // TODO(b/134676337): Open the device specified by `source` and return that.
+ panic("unimplemented")
+ }
+
+ // NewFilesystem call originated from within the sentry.
+ fd, ok := opts.InternalData.(uintptr)
+ if !ok {
+ return nil, errors.New("internal data for ext fs must be a uintptr containing the file descriptor to device")
+ }
+
+ // We do not close this file because that would close the underlying device
+ // file descriptor (which is required for reading the fs from disk).
+ // TODO(b/134676337): Use pkg/fd instead.
+ deviceFile := os.NewFile(fd, source)
+ if deviceFile == nil {
+ return nil, fmt.Errorf("ext4 device file descriptor is not valid: %d", fd)
+ }
+
+ return deviceFile, nil
+}
+// NewFilesystem implements vfs.FilesystemType.NewFilesystem.
+func (fstype filesystemType) NewFilesystem(ctx context.Context, creds *auth.Credentials, source string, opts vfs.NewFilesystemOptions) (*vfs.Filesystem, *vfs.Dentry, error) {
+ dev, err := getDeviceFd(source, opts)
+ if err != nil {
+ return nil, nil, err
+ }
+
+ fs := filesystem{dev: dev, inodeCache: make(map[uint32]*inode)}
+ fs.vfsfs.Init(&fs)
fs.sb, err = readSuperBlock(dev)
if err != nil {
- return nil, err
+ return nil, nil, err
}
if fs.sb.Magic() != linux.EXT_SUPER_MAGIC {
// mount(2) specifies that EINVAL should be returned if the superblock is
// invalid.
- return nil, syserror.EINVAL
+ return nil, nil, syserror.EINVAL
}
fs.bgs, err = readBlockGroups(dev, fs.sb)
if err != nil {
- return nil, err
+ return nil, nil, err
}
- return &fs, nil
+ return &fs.vfsfs, nil, nil
}
// getOrCreateInode gets the inode corresponding to the inode number passed in.
diff --git a/pkg/sentry/fs/ext/ext_test.go b/pkg/sentry/fs/ext/ext_test.go
new file mode 100644
index 000000000..f92e77450
--- /dev/null
+++ b/pkg/sentry/fs/ext/ext_test.go
@@ -0,0 +1,322 @@
+// Copyright 2019 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 ext
+
+import (
+ "fmt"
+ "os"
+ "path"
+ "testing"
+
+ "github.com/google/go-cmp/cmp"
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/sentry/context"
+ "gvisor.dev/gvisor/pkg/sentry/context/contexttest"
+ "gvisor.dev/gvisor/pkg/sentry/fs/ext/disklayout"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+
+ "gvisor.dev/gvisor/runsc/test/testutil"
+)
+
+const (
+ assetsDir = "pkg/sentry/fs/ext/assets"
+)
+
+var (
+ ext2ImagePath = path.Join(assetsDir, "tiny.ext2")
+ ext3ImagePath = path.Join(assetsDir, "tiny.ext3")
+ ext4ImagePath = path.Join(assetsDir, "tiny.ext4")
+)
+
+func beginning(_ uint64) uint64 {
+ return 0
+}
+
+func middle(i uint64) uint64 {
+ return i / 2
+}
+
+func end(i uint64) uint64 {
+ return i
+}
+
+// setUp opens imagePath as an ext Filesystem and returns all necessary
+// elements required to run tests. If error is non-nil, it also returns a tear
+// down function which must be called after the test is run for clean up.
+func setUp(t *testing.T, imagePath string) (context.Context, *vfs.Filesystem, *vfs.Dentry, func(), error) {
+ localImagePath, err := testutil.FindFile(imagePath)
+ if err != nil {
+ return nil, nil, nil, nil, fmt.Errorf("failed to open local image at path %s: %v", imagePath, err)
+ }
+
+ f, err := os.Open(localImagePath)
+ if err != nil {
+ return nil, nil, nil, nil, err
+ }
+
+ // Mount the ext4 fs and retrieve the inode structure for the file.
+ mockCtx := contexttest.Context(t)
+ fs, d, err := filesystemType{}.NewFilesystem(mockCtx, nil, localImagePath, vfs.NewFilesystemOptions{InternalData: f.Fd()})
+ if err != nil {
+ f.Close()
+ return nil, nil, nil, nil, err
+ }
+
+ tearDown := func() {
+ if err := f.Close(); err != nil {
+ t.Fatalf("tearDown failed: %v", err)
+ }
+ }
+ return mockCtx, fs, d, tearDown, nil
+}
+
+// TestFilesystemInit tests that the filesystem superblock and block group
+// descriptors are correctly read in and initialized.
+func TestFilesystemInit(t *testing.T) {
+ // sb only contains the immutable properties of the superblock.
+ type sb struct {
+ InodesCount uint32
+ BlocksCount uint64
+ MaxMountCount uint16
+ FirstDataBlock uint32
+ BlockSize uint64
+ BlocksPerGroup uint32
+ ClusterSize uint64
+ ClustersPerGroup uint32
+ InodeSize uint16
+ InodesPerGroup uint32
+ BgDescSize uint16
+ Magic uint16
+ Revision disklayout.SbRevision
+ CompatFeatures disklayout.CompatFeatures
+ IncompatFeatures disklayout.IncompatFeatures
+ RoCompatFeatures disklayout.RoCompatFeatures
+ }
+
+ // bg only contains the immutable properties of the block group descriptor.
+ type bg struct {
+ InodeTable uint64
+ BlockBitmap uint64
+ InodeBitmap uint64
+ ExclusionBitmap uint64
+ Flags disklayout.BGFlags
+ }
+
+ type fsInitTest struct {
+ name string
+ image string
+ wantSb sb
+ wantBgs []bg
+ }
+
+ tests := []fsInitTest{
+ {
+ name: "ext4 filesystem init",
+ image: ext4ImagePath,
+ wantSb: sb{
+ InodesCount: 0x10,
+ BlocksCount: 0x40,
+ MaxMountCount: 0xffff,
+ FirstDataBlock: 0x1,
+ BlockSize: 0x400,
+ BlocksPerGroup: 0x2000,
+ ClusterSize: 0x400,
+ ClustersPerGroup: 0x2000,
+ InodeSize: 0x80,
+ InodesPerGroup: 0x10,
+ BgDescSize: 0x40,
+ Magic: linux.EXT_SUPER_MAGIC,
+ Revision: disklayout.DynamicRev,
+ CompatFeatures: disklayout.CompatFeatures{
+ ExtAttr: true,
+ ResizeInode: true,
+ DirIndex: true,
+ },
+ IncompatFeatures: disklayout.IncompatFeatures{
+ DirentFileType: true,
+ Extents: true,
+ Is64Bit: true,
+ FlexBg: true,
+ },
+ RoCompatFeatures: disklayout.RoCompatFeatures{
+ Sparse: true,
+ LargeFile: true,
+ HugeFile: true,
+ DirNlink: true,
+ ExtraIsize: true,
+ MetadataCsum: true,
+ },
+ },
+ wantBgs: []bg{
+ {
+ InodeTable: 0x23,
+ BlockBitmap: 0x3,
+ InodeBitmap: 0x13,
+ Flags: disklayout.BGFlags{
+ InodeZeroed: true,
+ },
+ },
+ },
+ },
+ {
+ name: "ext3 filesystem init",
+ image: ext3ImagePath,
+ wantSb: sb{
+ InodesCount: 0x10,
+ BlocksCount: 0x40,
+ MaxMountCount: 0xffff,
+ FirstDataBlock: 0x1,
+ BlockSize: 0x400,
+ BlocksPerGroup: 0x2000,
+ ClusterSize: 0x400,
+ ClustersPerGroup: 0x2000,
+ InodeSize: 0x80,
+ InodesPerGroup: 0x10,
+ BgDescSize: 0x20,
+ Magic: linux.EXT_SUPER_MAGIC,
+ Revision: disklayout.DynamicRev,
+ CompatFeatures: disklayout.CompatFeatures{
+ ExtAttr: true,
+ ResizeInode: true,
+ DirIndex: true,
+ },
+ IncompatFeatures: disklayout.IncompatFeatures{
+ DirentFileType: true,
+ },
+ RoCompatFeatures: disklayout.RoCompatFeatures{
+ Sparse: true,
+ LargeFile: true,
+ },
+ },
+ wantBgs: []bg{
+ {
+ InodeTable: 0x5,
+ BlockBitmap: 0x3,
+ InodeBitmap: 0x4,
+ Flags: disklayout.BGFlags{
+ InodeZeroed: true,
+ },
+ },
+ },
+ },
+ {
+ name: "ext2 filesystem init",
+ image: ext2ImagePath,
+ wantSb: sb{
+ InodesCount: 0x10,
+ BlocksCount: 0x40,
+ MaxMountCount: 0xffff,
+ FirstDataBlock: 0x1,
+ BlockSize: 0x400,
+ BlocksPerGroup: 0x2000,
+ ClusterSize: 0x400,
+ ClustersPerGroup: 0x2000,
+ InodeSize: 0x80,
+ InodesPerGroup: 0x10,
+ BgDescSize: 0x20,
+ Magic: linux.EXT_SUPER_MAGIC,
+ Revision: disklayout.DynamicRev,
+ CompatFeatures: disklayout.CompatFeatures{
+ ExtAttr: true,
+ ResizeInode: true,
+ DirIndex: true,
+ },
+ IncompatFeatures: disklayout.IncompatFeatures{
+ DirentFileType: true,
+ },
+ RoCompatFeatures: disklayout.RoCompatFeatures{
+ Sparse: true,
+ LargeFile: true,
+ },
+ },
+ wantBgs: []bg{
+ {
+ InodeTable: 0x5,
+ BlockBitmap: 0x3,
+ InodeBitmap: 0x4,
+ Flags: disklayout.BGFlags{
+ InodeZeroed: true,
+ },
+ },
+ },
+ },
+ }
+
+ for _, test := range tests {
+ t.Run(test.name, func(t *testing.T) {
+ _, vfsfs, _, tearDown, err := setUp(t, test.image)
+ if err != nil {
+ t.Fatalf("setUp failed: %v", err)
+ }
+ defer tearDown()
+
+ fs, ok := vfsfs.Impl().(*filesystem)
+ if !ok {
+ t.Fatalf("ext filesystem of incorrect type: %T", vfsfs.Impl())
+ }
+
+ // Offload superblock and block group descriptors contents into
+ // local structs for comparison.
+ totalFreeInodes := uint32(0)
+ totalFreeBlocks := uint64(0)
+ gotSb := sb{
+ InodesCount: fs.sb.InodesCount(),
+ BlocksCount: fs.sb.BlocksCount(),
+ MaxMountCount: fs.sb.MaxMountCount(),
+ FirstDataBlock: fs.sb.FirstDataBlock(),
+ BlockSize: fs.sb.BlockSize(),
+ BlocksPerGroup: fs.sb.BlocksPerGroup(),
+ ClusterSize: fs.sb.ClusterSize(),
+ ClustersPerGroup: fs.sb.ClustersPerGroup(),
+ InodeSize: fs.sb.InodeSize(),
+ InodesPerGroup: fs.sb.InodesPerGroup(),
+ BgDescSize: fs.sb.BgDescSize(),
+ Magic: fs.sb.Magic(),
+ Revision: fs.sb.Revision(),
+ CompatFeatures: fs.sb.CompatibleFeatures(),
+ IncompatFeatures: fs.sb.IncompatibleFeatures(),
+ RoCompatFeatures: fs.sb.ReadOnlyCompatibleFeatures(),
+ }
+ gotNumBgs := len(fs.bgs)
+ gotBgs := make([]bg, gotNumBgs)
+ for i := 0; i < gotNumBgs; i++ {
+ gotBgs[i].InodeTable = fs.bgs[i].InodeTable()
+ gotBgs[i].BlockBitmap = fs.bgs[i].BlockBitmap()
+ gotBgs[i].InodeBitmap = fs.bgs[i].InodeBitmap()
+ gotBgs[i].ExclusionBitmap = fs.bgs[i].ExclusionBitmap()
+ gotBgs[i].Flags = fs.bgs[i].Flags()
+
+ totalFreeInodes += fs.bgs[i].FreeInodesCount()
+ totalFreeBlocks += uint64(fs.bgs[i].FreeBlocksCount())
+ }
+
+ if diff := cmp.Diff(gotSb, test.wantSb); diff != "" {
+ t.Errorf("superblock mismatch (-want +got):\n%s", diff)
+ }
+
+ if diff := cmp.Diff(gotBgs, test.wantBgs); diff != "" {
+ t.Errorf("block group descriptors mismatch (-want +got):\n%s", diff)
+ }
+
+ if diff := cmp.Diff(totalFreeInodes, fs.sb.FreeInodesCount()); diff != "" {
+ t.Errorf("total free inodes mismatch (-want +got):\n%s", diff)
+ }
+
+ if diff := cmp.Diff(totalFreeBlocks, fs.sb.FreeBlocksCount()); diff != "" {
+ t.Errorf("total free blocks mismatch (-want +got):\n%s", diff)
+ }
+ })
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-25 19:51:20 +0000