Files
wazero/internal/sys/fs_test.go
2023-05-23 10:18:27 -07:00

361 lines
8.6 KiB
Go

package sys
import (
"embed"
"errors"
"io/fs"
"os"
"syscall"
"testing"
"testing/fstest"
"github.com/tetratelabs/wazero/internal/fsapi"
"github.com/tetratelabs/wazero/internal/sysfs"
testfs "github.com/tetratelabs/wazero/internal/testing/fs"
"github.com/tetratelabs/wazero/internal/testing/require"
)
//go:embed testdata
var testdata embed.FS
func TestNewFSContext(t *testing.T) {
embedFS, err := fs.Sub(testdata, "testdata")
require.NoError(t, err)
dirfs := sysfs.NewDirFS(".")
// Test various usual configuration for the file system.
tests := []struct {
name string
fs fsapi.FS
}{
{
name: "embed.FS",
fs: sysfs.Adapt(embedFS),
},
{
name: "NewDirFS",
// Don't use "testdata" because it may not be present in
// cross-architecture (a.k.a. scratch) build containers.
fs: dirfs,
},
{
name: "NewReadFS",
fs: sysfs.NewReadFS(dirfs),
},
{
name: "fstest.MapFS",
fs: sysfs.Adapt(fstest.MapFS{}),
},
}
for _, tt := range tests {
tc := tt
t.Run(tc.name, func(t *testing.T) {
c := Context{}
err := c.NewFSContext(nil, nil, nil, tc.fs)
require.NoError(t, err)
fsc := c.fsc
defer fsc.Close()
preopenedDir, _ := fsc.openedFiles.Lookup(FdPreopen)
require.Equal(t, tc.fs, fsc.rootFS)
require.NotNil(t, preopenedDir)
require.Equal(t, "/", preopenedDir.Name)
// Verify that each call to OpenFile returns a different file
// descriptor.
f1, errno := fsc.OpenFile(preopenedDir.FS, preopenedDir.Name, 0, 0)
require.EqualErrno(t, 0, errno)
require.NotEqual(t, FdPreopen, f1)
// Verify that file descriptors are reused.
//
// Note that this specific behavior is not required by WASI which
// only documents that file descriptor numbers will be selected
// randomly and applications should not rely on them. We added this
// test to ensure that our implementation properly reuses descriptor
// numbers but if we were to change the reuse strategy, this test
// would likely break and need to be updated.
require.EqualErrno(t, 0, fsc.CloseFile(f1))
f2, errno := fsc.OpenFile(preopenedDir.FS, preopenedDir.Name, 0, 0)
require.EqualErrno(t, 0, errno)
require.Equal(t, f1, f2)
})
}
}
func TestFSContext_CloseFile(t *testing.T) {
embedFS, err := fs.Sub(testdata, "testdata")
require.NoError(t, err)
testFS := sysfs.Adapt(embedFS)
c := Context{}
err = c.NewFSContext(nil, nil, nil, testFS)
require.NoError(t, err)
fsc := c.fsc
defer fsc.Close()
fdToClose, errno := fsc.OpenFile(testFS, "empty.txt", os.O_RDONLY, 0)
require.EqualErrno(t, 0, errno)
fdToKeep, errno := fsc.OpenFile(testFS, "test.txt", os.O_RDONLY, 0)
require.EqualErrno(t, 0, errno)
// Close
require.EqualErrno(t, 0, fsc.CloseFile(fdToClose))
// Verify fdToClose is closed and removed from the opened FDs.
_, ok := fsc.LookupFile(fdToClose)
require.False(t, ok)
// Verify fdToKeep is not closed
_, ok = fsc.LookupFile(fdToKeep)
require.True(t, ok)
t.Run("EBADF for an invalid FD", func(t *testing.T) {
require.EqualErrno(t, syscall.EBADF, fsc.CloseFile(42)) // 42 is an arbitrary invalid FD
})
t.Run("Can close a pre-open", func(t *testing.T) {
require.EqualErrno(t, 0, fsc.CloseFile(FdPreopen))
})
}
func TestUnimplementedFSContext(t *testing.T) {
c := Context{}
err := c.NewFSContext(nil, nil, nil, fsapi.UnimplementedFS{})
require.NoError(t, err)
testFS := &c.fsc
require.NoError(t, err)
expected := &FSContext{rootFS: fsapi.UnimplementedFS{}}
noopStdin, _ := stdinFile(nil)
expected.openedFiles.Insert(noopStdin)
noopStdout, _ := stdioWriterFile("stdout", nil)
expected.openedFiles.Insert(noopStdout)
noopStderr, _ := stdioWriterFile("stderr", nil)
expected.openedFiles.Insert(noopStderr)
t.Run("Close closes", func(t *testing.T) {
err := testFS.Close()
require.NoError(t, err)
// Closes opened files
require.Equal(t, &FSContext{rootFS: fsapi.UnimplementedFS{}}, testFS)
})
}
func TestCompositeFSContext(t *testing.T) {
tmpDir1 := t.TempDir()
testFS1 := sysfs.NewDirFS(tmpDir1)
tmpDir2 := t.TempDir()
testFS2 := sysfs.NewDirFS(tmpDir2)
rootFS, err := sysfs.NewRootFS([]fsapi.FS{testFS2, testFS1}, []string{"/tmp", "/"})
require.NoError(t, err)
c := Context{}
err = c.NewFSContext(nil, nil, nil, rootFS)
require.NoError(t, err)
testFS := &c.fsc
// Ensure the pre-opens have exactly the name specified, and are in order.
preopen3, ok := testFS.openedFiles.Lookup(3)
require.True(t, ok)
require.Equal(t, "/tmp", preopen3.Name)
preopen4, ok := testFS.openedFiles.Lookup(4)
require.True(t, ok)
require.Equal(t, "/", preopen4.Name)
t.Run("Close closes", func(t *testing.T) {
err := testFS.Close()
require.NoError(t, err)
// Closes opened files
require.Equal(t, &FSContext{rootFS: rootFS}, testFS)
})
}
func TestContext_Close(t *testing.T) {
testFS := sysfs.Adapt(testfs.FS{"foo": &testfs.File{}})
c := Context{}
err := c.NewFSContext(nil, nil, nil, testFS)
require.NoError(t, err)
fsc := c.fsc
// Verify base case
require.Equal(t, 1+FdPreopen, int32(fsc.openedFiles.Len()))
_, errno := fsc.OpenFile(testFS, "foo", os.O_RDONLY, 0)
require.EqualErrno(t, 0, errno)
require.Equal(t, 2+FdPreopen, int32(fsc.openedFiles.Len()))
// Closing should not err.
require.NoError(t, fsc.Close())
// Verify our intended side-effect
require.Zero(t, fsc.openedFiles.Len())
// Verify no error closing again.
require.NoError(t, fsc.Close())
}
func TestContext_Close_Error(t *testing.T) {
file := &testfs.File{CloseErr: errors.New("error closing")}
testFS := sysfs.Adapt(testfs.FS{"foo": file})
c := Context{}
err := c.NewFSContext(nil, nil, nil, testFS)
require.NoError(t, err)
fsc := c.fsc
// open another file
_, errno := fsc.OpenFile(testFS, "foo", os.O_RDONLY, 0)
require.EqualErrno(t, 0, errno)
// arbitrary errors coerce to EIO
require.EqualErrno(t, syscall.EIO, fsc.Close())
// Paths should clear even under error
require.Zero(t, fsc.openedFiles.Len(), "expected no opened files")
}
func TestFSContext_Renumber(t *testing.T) {
tmpDir := t.TempDir()
dirFs := sysfs.NewDirFS(tmpDir)
const dirName = "dir"
errno := dirFs.Mkdir(dirName, 0o700)
require.EqualErrno(t, 0, errno)
c := Context{}
err := c.NewFSContext(nil, nil, nil, dirFs)
require.NoError(t, err)
fsc := c.fsc
defer fsc.Close()
for _, toFd := range []int32{10, 100, 100} {
fromFd, errno := fsc.OpenFile(dirFs, dirName, os.O_RDONLY, 0)
require.EqualErrno(t, 0, errno)
prevDirFile, ok := fsc.LookupFile(fromFd)
require.True(t, ok)
require.EqualErrno(t, 0, fsc.Renumber(fromFd, toFd))
renumberedDirFile, ok := fsc.LookupFile(toFd)
require.True(t, ok)
require.Equal(t, prevDirFile, renumberedDirFile)
// Previous file descriptor shouldn't be used.
_, ok = fsc.LookupFile(fromFd)
require.False(t, ok)
}
t.Run("errors", func(t *testing.T) {
// Sanity check for 3 being preopen.
preopen, ok := fsc.LookupFile(3)
require.True(t, ok)
require.True(t, preopen.IsPreopen)
// From is preopen.
require.Equal(t, syscall.ENOTSUP, fsc.Renumber(3, 100))
// From does not exist.
require.Equal(t, syscall.EBADF, fsc.Renumber(12345, 3))
// Both are preopen.
require.Equal(t, syscall.ENOTSUP, fsc.Renumber(3, 3))
})
}
func TestReaddDir_Rewind(t *testing.T) {
tests := []struct {
name string
f *Readdir
cookie int64
expectedCookie int64
expectedErrno syscall.Errno
}{
{
name: "no prior call",
},
{
name: "no prior call, but passed a cookie",
cookie: 1,
expectedErrno: syscall.EINVAL,
},
{
name: "cookie is negative",
f: &Readdir{
countRead: 3,
},
cookie: -1,
expectedErrno: syscall.EINVAL,
},
{
name: "cookie is greater than last d_next",
f: &Readdir{
countRead: 3,
},
cookie: 5,
expectedErrno: syscall.EINVAL,
},
{
name: "cookie is last pos",
f: &Readdir{
countRead: 3,
},
cookie: 3,
},
{
name: "cookie is one before last pos",
f: &Readdir{
countRead: 3,
},
cookie: 2,
},
{
name: "cookie is before current entries",
f: &Readdir{
countRead: direntBufSize + 2,
},
cookie: 1,
expectedErrno: syscall.ENOSYS, // not implemented
},
{
name: "read from the beginning (cookie=0)",
f: &Readdir{
dirInit: func() ([]fsapi.Dirent, syscall.Errno) {
return []fsapi.Dirent{{Name: "."}, {Name: ".."}}, 0
},
dirReader: func(n uint64) ([]fsapi.Dirent, syscall.Errno) {
return nil, 0
},
cursor: 3,
},
cookie: 0,
},
}
for _, tt := range tests {
tc := tt
t.Run(tc.name, func(t *testing.T) {
f := tc.f
if f == nil {
f = &Readdir{}
}
errno := f.Rewind(tc.cookie)
require.EqualErrno(t, tc.expectedErrno, errno)
})
}
}