Fixed two issues with error responses to the kernel.

One of them caused the writeMessage error observed on OS X in
GoogleCloudPlatform/gcsfuse#101.
geesefs-0-30-9
Aaron Jacobs 2015-08-04 12:30:01 +10:00
commit b5c1fd6ddc
3 changed files with 350 additions and 13 deletions

View File

@ -423,15 +423,37 @@ func (c *Connection) kernelResponse(
h := m.OutHeader()
h.Unique = fuseID
// Did the user return an error? Otherwise, fill in the rest of the response.
// Special case: handle the ops for which the kernel expects no response.
// interruptOp .
switch op.(type) {
case *fuseops.ForgetInodeOp:
noResponse = true
return
case *interruptOp:
noResponse = true
return
}
// If the user returned the error, fill in the error field of the outgoing
// message header.
if opErr != nil {
m.OutHeader().Error = -int32(syscall.EIO)
if errno, ok := opErr.(syscall.Errno); ok {
m.OutHeader().Error = -int32(errno)
} else {
m.OutHeader().Error = -int32(syscall.EIO)
}
} else {
noResponse = c.kernelResponseForOp(m, op)
// Special case: for some types, convertInMessage grew the message in order
// to obtain a destination buffer. Make sure that we shrink back to just
// the header, because on OS X the kernel otherwise returns EINVAL when we
// attempt to write an error response with a length that extends beyond the
// header.
m.Shrink(uintptr(m.Len() - int(buffer.OutMessageInitialSize)))
}
// Otherwise, fill in the rest of the response.
if opErr == nil {
c.kernelResponseForOp(m, op)
}
h.Len = uint32(m.Len())
@ -442,7 +464,7 @@ func (c *Connection) kernelResponse(
// op.
func (c *Connection) kernelResponseForOp(
m *buffer.OutMessage,
op interface{}) (noResponse bool) {
op interface{}) {
// Create the appropriate output message
switch o := op.(type) {
case *fuseops.LookUpInodeOp:
@ -464,9 +486,6 @@ func (c *Connection) kernelResponseForOp(
o.AttributesExpiration)
convertAttributes(o.Inode, &o.Attributes, &out.Attr)
case *fuseops.ForgetInodeOp:
noResponse = true
case *fuseops.MkDirOp:
size := fusekernel.EntryOutSize(c.protocol)
out := (*fusekernel.EntryOut)(m.Grow(size))
@ -541,9 +560,6 @@ func (c *Connection) kernelResponseForOp(
case *statFSOp:
m.Grow(unsafe.Sizeof(fusekernel.StatfsOut{}))
case *interruptOp:
noResponse = true
case *initOp:
out := (*fusekernel.InitOut)(m.Grow(unsafe.Sizeof(fusekernel.InitOut{})))
@ -554,7 +570,7 @@ func (c *Connection) kernelResponseForOp(
out.MaxWrite = o.MaxWrite
default:
panic(fmt.Sprintf("Unknown op: %#v", op))
panic(fmt.Sprintf("Unexpected op: %#v", op))
}
return

215
samples/errorfs/error_fs.go Normal file
View File

@ -0,0 +1,215 @@
// Copyright 2015 Google Inc. All Rights Reserved.
//
// 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 errorfs
import (
"fmt"
"os"
"reflect"
"sync"
"syscall"
"golang.org/x/net/context"
"github.com/jacobsa/fuse/fuseops"
"github.com/jacobsa/fuse/fuseutil"
)
const FooContents = "xxxx"
const fooInodeID = fuseops.RootInodeID + 1
var fooAttrs = fuseops.InodeAttributes{
Nlink: 1,
Size: uint64(len(FooContents)),
Mode: 0444,
}
// A file system whose sole contents are a file named "foo" containing the
// string defined by FooContents.
//
// The file system can be configured to returned canned errors for particular
// operations using the method SetError.
type FS interface {
fuseutil.FileSystem
// Cause the file system to return the supplied error for all future
// operations matching the supplied type.
SetError(t reflect.Type, err syscall.Errno)
}
func New() (fs FS, err error) {
fs = &errorFS{
errors: make(map[reflect.Type]syscall.Errno),
}
return
}
type errorFS struct {
fuseutil.NotImplementedFileSystem
mu sync.Mutex
// GUARDED_BY(mu)
errors map[reflect.Type]syscall.Errno
}
// LOCKS_EXCLUDED(fs.mu)
func (fs *errorFS) SetError(t reflect.Type, err syscall.Errno) {
fs.mu.Lock()
defer fs.mu.Unlock()
fs.errors[t] = err
}
// LOCKS_EXCLUDED(fs.mu)
func (fs *errorFS) transformError(op interface{}, err *error) bool {
fs.mu.Lock()
defer fs.mu.Unlock()
cannedErr, ok := fs.errors[reflect.TypeOf(op)]
if ok {
*err = cannedErr
return true
}
return false
}
////////////////////////////////////////////////////////////////////////
// File system methods
////////////////////////////////////////////////////////////////////////
// LOCKS_EXCLUDED(fs.mu)
func (fs *errorFS) GetInodeAttributes(
ctx context.Context,
op *fuseops.GetInodeAttributesOp) (err error) {
if fs.transformError(op, &err) {
return
}
// Figure out which inode the request is for.
switch {
case op.Inode == fuseops.RootInodeID:
op.Attributes = fuseops.InodeAttributes{
Mode: os.ModeDir | 0777,
}
case op.Inode == fooInodeID:
op.Attributes = fooAttrs
default:
err = fmt.Errorf("Unknown inode: %d", op.Inode)
return
}
return
}
// LOCKS_EXCLUDED(fs.mu)
func (fs *errorFS) LookUpInode(
ctx context.Context,
op *fuseops.LookUpInodeOp) (err error) {
if fs.transformError(op, &err) {
return
}
// Is this a known inode?
if !(op.Parent == fuseops.RootInodeID && op.Name == "foo") {
err = syscall.ENOENT
return
}
op.Entry.Child = fooInodeID
op.Entry.Attributes = fooAttrs
return
}
// LOCKS_EXCLUDED(fs.mu)
func (fs *errorFS) OpenFile(
ctx context.Context,
op *fuseops.OpenFileOp) (err error) {
if fs.transformError(op, &err) {
return
}
if op.Inode != fooInodeID {
err = fmt.Errorf("Unsupported inode ID: %d", op.Inode)
return
}
return
}
// LOCKS_EXCLUDED(fs.mu)
func (fs *errorFS) ReadFile(
ctx context.Context,
op *fuseops.ReadFileOp) (err error) {
if fs.transformError(op, &err) {
return
}
if op.Inode != fooInodeID || op.Offset != 0 {
err = fmt.Errorf("Unexpected request: %#v", op)
return
}
op.BytesRead = copy(op.Dst, FooContents)
return
}
// LOCKS_EXCLUDED(fs.mu)
func (fs *errorFS) OpenDir(
ctx context.Context,
op *fuseops.OpenDirOp) (err error) {
if fs.transformError(op, &err) {
return
}
if op.Inode != fuseops.RootInodeID {
err = fmt.Errorf("Unsupported inode ID: %d", op.Inode)
return
}
return
}
// LOCKS_EXCLUDED(fs.mu)
func (fs *errorFS) ReadDir(
ctx context.Context,
op *fuseops.ReadDirOp) (err error) {
if fs.transformError(op, &err) {
return
}
if op.Inode != fuseops.RootInodeID || op.Offset != 0 {
err = fmt.Errorf("Unexpected request: %#v", op)
return
}
op.BytesRead = fuseutil.WriteDirent(
op.Dst,
fuseutil.Dirent{
Offset: 0,
Inode: fooInodeID,
Name: "foo",
Type: fuseutil.DT_File,
})
return
}

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@ -0,0 +1,106 @@
// Copyright 2015 Google Inc. All Rights Reserved.
//
// 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 errorfs_test
import (
"io/ioutil"
"os"
"path"
"reflect"
"syscall"
"testing"
"github.com/jacobsa/fuse/fuseops"
"github.com/jacobsa/fuse/fuseutil"
"github.com/jacobsa/fuse/samples"
"github.com/jacobsa/fuse/samples/errorfs"
. "github.com/jacobsa/oglematchers"
. "github.com/jacobsa/ogletest"
)
func TestErrorFS(t *testing.T) { RunTests(t) }
////////////////////////////////////////////////////////////////////////
// Boilerplate
////////////////////////////////////////////////////////////////////////
type ErrorFSTest struct {
samples.SampleTest
fs errorfs.FS
}
func init() { RegisterTestSuite(&ErrorFSTest{}) }
var _ SetUpInterface = &ErrorFSTest{}
var _ TearDownInterface = &ErrorFSTest{}
func (t *ErrorFSTest) SetUp(ti *TestInfo) {
var err error
// Create the file system.
t.fs, err = errorfs.New()
AssertEq(nil, err)
t.Server = fuseutil.NewFileSystemServer(t.fs)
// Mount it.
t.SampleTest.SetUp(ti)
}
////////////////////////////////////////////////////////////////////////
// Tests
////////////////////////////////////////////////////////////////////////
func (t *ErrorFSTest) OpenFile() {
t.fs.SetError(reflect.TypeOf(&fuseops.OpenFileOp{}), syscall.EOWNERDEAD)
f, err := os.Open(path.Join(t.Dir, "foo"))
defer f.Close()
ExpectThat(err, Error(MatchesRegexp("open.*: .*owner died")))
}
func (t *ErrorFSTest) ReadFile() {
t.fs.SetError(reflect.TypeOf(&fuseops.ReadFileOp{}), syscall.EOWNERDEAD)
// Open
f, err := os.Open(path.Join(t.Dir, "foo"))
defer f.Close()
AssertEq(nil, err)
// Read
_, err = ioutil.ReadAll(f)
ExpectThat(err, Error(MatchesRegexp("read.*: .*owner died")))
}
func (t *ErrorFSTest) OpenDir() {
t.fs.SetError(reflect.TypeOf(&fuseops.OpenDirOp{}), syscall.EOWNERDEAD)
f, err := os.Open(t.Dir)
defer f.Close()
ExpectThat(err, Error(MatchesRegexp("open.*: .*owner died")))
}
func (t *ErrorFSTest) ReadDir() {
t.fs.SetError(reflect.TypeOf(&fuseops.ReadDirOp{}), syscall.EOWNERDEAD)
// Open
f, err := os.Open(t.Dir)
defer f.Close()
AssertEq(nil, err)
// Read
_, err = f.Readdirnames(1)
ExpectThat(err, Error(MatchesRegexp("read.*: .*owner died")))
}