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-rw-r--r--pkg/sentry/fsimpl/fuse/BUILD6
-rw-r--r--pkg/sentry/fsimpl/fuse/connection.go11
-rw-r--r--pkg/sentry/fsimpl/fuse/connection_control.go62
-rw-r--r--pkg/sentry/fsimpl/fuse/connection_test.go127
-rw-r--r--pkg/sentry/fsimpl/fuse/dev.go51
-rw-r--r--pkg/sentry/fsimpl/fuse/dev_test.go4
-rw-r--r--pkg/sentry/fsimpl/fuse/fusefs.go12
-rw-r--r--pkg/sentry/fsimpl/fuse/utils_test.go111
8 files changed, 362 insertions, 22 deletions
diff --git a/pkg/sentry/fsimpl/fuse/BUILD b/pkg/sentry/fsimpl/fuse/BUILD
index 23660a708..77025772c 100644
--- a/pkg/sentry/fsimpl/fuse/BUILD
+++ b/pkg/sentry/fsimpl/fuse/BUILD
@@ -66,7 +66,11 @@ go_library(
go_test(
name = "fuse_test",
size = "small",
- srcs = ["dev_test.go"],
+ srcs = [
+ "connection_test.go",
+ "dev_test.go",
+ "utils_test.go",
+ ],
library = ":fuse",
deps = [
"//pkg/abi/linux",
diff --git a/pkg/sentry/fsimpl/fuse/connection.go b/pkg/sentry/fsimpl/fuse/connection.go
index 122b7d92f..6009cdf97 100644
--- a/pkg/sentry/fsimpl/fuse/connection.go
+++ b/pkg/sentry/fsimpl/fuse/connection.go
@@ -179,7 +179,6 @@ func newFUSEConnection(_ context.Context, fd *vfs.FileDescription, opts *filesys
// Mark the device as ready so it can be used. /dev/fuse can only be used if the FD was used to
// mount a FUSE filesystem.
fuseFD := fd.Impl().(*DeviceFD)
- fuseFD.mounted = true
// Create the writeBuf for the header to be stored in.
hdrLen := uint32((*linux.FUSEHeaderOut)(nil).SizeBytes())
@@ -282,6 +281,16 @@ func (conn *connection) callFuture(t *kernel.Task, r *Request) (*futureResponse,
// callFutureLocked makes a request to the server and returns a future response.
func (conn *connection) callFutureLocked(t *kernel.Task, r *Request) (*futureResponse, error) {
+ // Check connected again holding conn.mu.
+ conn.mu.Lock()
+ if !conn.connected {
+ conn.mu.Unlock()
+ // we checked connected before,
+ // this must be due to aborted connection.
+ return nil, syserror.ECONNABORTED
+ }
+ conn.mu.Unlock()
+
conn.fd.queue.PushBack(r)
conn.fd.numActiveRequests++
fut := newFutureResponse(r)
diff --git a/pkg/sentry/fsimpl/fuse/connection_control.go b/pkg/sentry/fsimpl/fuse/connection_control.go
index d84d9caf2..a63c66e7c 100644
--- a/pkg/sentry/fsimpl/fuse/connection_control.go
+++ b/pkg/sentry/fsimpl/fuse/connection_control.go
@@ -16,8 +16,10 @@ package fuse
import (
"sync/atomic"
+ "syscall"
"gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
)
@@ -181,3 +183,63 @@ func (conn *connection) initProcessReply(out *linux.FUSEInitOut, hasSysAdminCap
return nil
}
+
+// Abort this FUSE connection.
+// It tries to acquire conn.fd.mu, conn.lock, conn.bgLock in order.
+// All possible requests waiting or blocking will be aborted.
+func (conn *connection) Abort(ctx context.Context) {
+ conn.fd.mu.Lock()
+ conn.mu.Lock()
+ conn.asyncMu.Lock()
+
+ if !conn.connected {
+ conn.asyncMu.Unlock()
+ conn.mu.Unlock()
+ conn.fd.mu.Unlock()
+ return
+ }
+
+ conn.connected = false
+
+ // Empty the `fd.queue` that holds the requests
+ // not yet read by the FUSE daemon yet.
+ // These are a subset of the requests in `fuse.completion` map.
+ for !conn.fd.queue.Empty() {
+ req := conn.fd.queue.Front()
+ conn.fd.queue.Remove(req)
+ }
+
+ var terminate []linux.FUSEOpID
+
+ // 2. Collect the requests have not been sent to FUSE daemon,
+ // or have not received a reply.
+ for unique := range conn.fd.completions {
+ terminate = append(terminate, unique)
+ }
+
+ // Release all locks to avoid deadlock.
+ conn.asyncMu.Unlock()
+ conn.mu.Unlock()
+ conn.fd.mu.Unlock()
+
+ // 1. The requets blocked before initialization.
+ // Will reach call() `connected` check and return.
+ if !conn.Initialized() {
+ conn.SetInitialized()
+ }
+
+ // 2. Terminate the requests collected above.
+ // Set ECONNABORTED error.
+ // sendError() will remove them from `fd.completion` map.
+ // Will enter the path of a normally received error.
+ for _, toTerminate := range terminate {
+ conn.fd.sendError(ctx, -int32(syscall.ECONNABORTED), toTerminate)
+ }
+
+ // 3. The requests not yet written to FUSE device.
+ // Early terminate.
+ // Will reach callFutureLocked() `connected` check and return.
+ close(conn.fd.fullQueueCh)
+
+ // TODO(gvisor.dev/issue/3528): Forget all pending forget reqs.
+}
diff --git a/pkg/sentry/fsimpl/fuse/connection_test.go b/pkg/sentry/fsimpl/fuse/connection_test.go
new file mode 100644
index 000000000..6aa77b36d
--- /dev/null
+++ b/pkg/sentry/fsimpl/fuse/connection_test.go
@@ -0,0 +1,127 @@
+// Copyright 2020 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 fuse
+
+import (
+ "math/rand"
+ "syscall"
+ "testing"
+
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+ "gvisor.dev/gvisor/pkg/syserror"
+)
+
+// TestConnectionInitBlock tests if initialization
+// correctly blocks and unblocks the connection.
+// Since it's unfeasible to test kernelTask.Block() in unit test,
+// the code in Call() are not tested here.
+func TestConnectionInitBlock(t *testing.T) {
+ s := setup(t)
+ defer s.Destroy()
+
+ k := kernel.KernelFromContext(s.Ctx)
+
+ conn, _, err := newTestConnection(s, k, maxActiveRequestsDefault)
+ if err != nil {
+ t.Fatalf("newTestConnection: %v", err)
+ }
+
+ select {
+ case <-conn.initializedChan:
+ t.Fatalf("initializedChan should be blocking before SetInitialized")
+ default:
+ }
+
+ conn.SetInitialized()
+
+ select {
+ case <-conn.initializedChan:
+ default:
+ t.Fatalf("initializedChan should not be blocking after SetInitialized")
+ }
+}
+
+func TestConnectionAbort(t *testing.T) {
+ s := setup(t)
+ defer s.Destroy()
+
+ k := kernel.KernelFromContext(s.Ctx)
+ creds := auth.CredentialsFromContext(s.Ctx)
+ task := kernel.TaskFromContext(s.Ctx)
+
+ const maxActiveRequest uint64 = 10
+
+ conn, _, err := newTestConnection(s, k, maxActiveRequest)
+ if err != nil {
+ t.Fatalf("newTestConnection: %v", err)
+ }
+
+ testObj := &testPayload{
+ data: rand.Uint32(),
+ }
+
+ var futNormal []*futureResponse
+
+ for i := 0; i < 2*int(maxActiveRequest); i++ {
+ req, err := conn.NewRequest(creds, uint32(i), uint64(i), 0, testObj)
+ if err != nil {
+ t.Fatalf("NewRequest creation failed: %v", err)
+ }
+ if i < int(maxActiveRequest) {
+ // Issue the requests that will not be blocked due to maxActiveRequest.
+ fut, err := conn.callFutureLocked(task, req)
+ if err != nil {
+ t.Fatalf("callFutureLocked failed: %v", err)
+ }
+ futNormal = append(futNormal, fut)
+ } else {
+ go func(t *testing.T) {
+ // The requests beyond maxActiveRequest will be blocked and receive expected errors.
+ _, err := conn.callFutureLocked(task, req)
+ if err != syserror.ECONNABORTED && err != syserror.ENOTCONN {
+ t.Fatalf("Incorrect error code received for blocked callFutureLocked() on aborted connection")
+ }
+ }(t)
+ }
+ }
+
+ conn.Abort(s.Ctx)
+
+ // Abort should unblock the initialization channel.
+ select {
+ case <-conn.initializedChan:
+ default:
+ t.Fatalf("initializedChan should not be blocking after SetInitialized")
+ }
+
+ // Abort will return ECONNABORTED error to unblocked requests.
+ for _, fut := range futNormal {
+ if fut.getResponse().hdr.Error != -int32(syscall.ECONNABORTED) {
+ t.Fatalf("Incorrect error code received for aborted connection")
+ }
+ }
+
+ // After abort, Call() should return directly with ENOTCONN.
+ req, err := conn.NewRequest(creds, 0, 0, 0, testObj)
+ if err != nil {
+ t.Fatalf("NewRequest creation failed: %v", err)
+ }
+ _, err = conn.Call(task, req)
+ if err != syserror.ENOTCONN {
+ t.Fatalf("Incorrect error code received for Call() after connection aborted")
+ }
+
+}
diff --git a/pkg/sentry/fsimpl/fuse/dev.go b/pkg/sentry/fsimpl/fuse/dev.go
index 6f0b896cb..64c3e32e2 100644
--- a/pkg/sentry/fsimpl/fuse/dev.go
+++ b/pkg/sentry/fsimpl/fuse/dev.go
@@ -55,9 +55,6 @@ type DeviceFD struct {
vfs.DentryMetadataFileDescriptionImpl
vfs.NoLockFD
- // mounted specifies whether a FUSE filesystem was mounted using the DeviceFD.
- mounted bool
-
// nextOpID is used to create new requests.
nextOpID linux.FUSEOpID
@@ -99,13 +96,15 @@ type DeviceFD struct {
// Release implements vfs.FileDescriptionImpl.Release.
func (fd *DeviceFD) Release(context.Context) {
- fd.fs.conn.connected = false
+ if fd.fs != nil {
+ fd.fs.conn.connected = false
+ }
}
// PRead implements vfs.FileDescriptionImpl.PRead.
func (fd *DeviceFD) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) {
// Operations on /dev/fuse don't make sense until a FUSE filesystem is mounted.
- if !fd.mounted {
+ if fd.fs == nil {
return 0, syserror.EPERM
}
@@ -115,10 +114,16 @@ func (fd *DeviceFD) PRead(ctx context.Context, dst usermem.IOSequence, offset in
// Read implements vfs.FileDescriptionImpl.Read.
func (fd *DeviceFD) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) {
// Operations on /dev/fuse don't make sense until a FUSE filesystem is mounted.
- if !fd.mounted {
+ if fd.fs == nil {
return 0, syserror.EPERM
}
+ // Return ENODEV if the filesystem is umounted.
+ if fd.fs.umounted {
+ // TODO(gvisor.dev/issue/3525): return ECONNABORTED if aborted via fuse control fs.
+ return 0, syserror.ENODEV
+ }
+
// We require that any Read done on this filesystem have a sane minimum
// read buffer. It must have the capacity for the fixed parts of any request
// header (Linux uses the request header and the FUSEWriteIn header for this
@@ -165,7 +170,7 @@ func (fd *DeviceFD) readLocked(ctx context.Context, dst usermem.IOSequence, opts
}
// Return the error to the calling task.
- if err := fd.sendError(ctx, errno, req); err != nil {
+ if err := fd.sendError(ctx, errno, req.hdr.Unique); err != nil {
return 0, err
}
@@ -217,7 +222,7 @@ func (fd *DeviceFD) readLocked(ctx context.Context, dst usermem.IOSequence, opts
// PWrite implements vfs.FileDescriptionImpl.PWrite.
func (fd *DeviceFD) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) {
// Operations on /dev/fuse don't make sense until a FUSE filesystem is mounted.
- if !fd.mounted {
+ if fd.fs == nil {
return 0, syserror.EPERM
}
@@ -234,10 +239,15 @@ func (fd *DeviceFD) Write(ctx context.Context, src usermem.IOSequence, opts vfs.
// writeLocked implements writing to the fuse device while locked with DeviceFD.mu.
func (fd *DeviceFD) writeLocked(ctx context.Context, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) {
// Operations on /dev/fuse don't make sense until a FUSE filesystem is mounted.
- if !fd.mounted {
+ if fd.fs == nil {
return 0, syserror.EPERM
}
+ // Return ENODEV if the filesystem is umounted.
+ if fd.fs.umounted {
+ return 0, syserror.ENODEV
+ }
+
var cn, n int64
hdrLen := uint32((*linux.FUSEHeaderOut)(nil).SizeBytes())
@@ -303,7 +313,8 @@ func (fd *DeviceFD) writeLocked(ctx context.Context, src usermem.IOSequence, opt
// Currently we simply discard the reply for FUSE_RELEASE.
return n + src.NumBytes(), nil
}
- // Server sent us a response for a request we never sent?
+ // Server sent us a response for a request we never sent,
+ // or for which we already received a reply (e.g. aborted), an unlikely event.
return 0, syserror.EINVAL
}
@@ -343,7 +354,14 @@ func (fd *DeviceFD) Readiness(mask waiter.EventMask) waiter.EventMask {
// locked with DeviceFD.mu.
func (fd *DeviceFD) readinessLocked(mask waiter.EventMask) waiter.EventMask {
var ready waiter.EventMask
- ready |= waiter.EventOut // FD is always writable
+
+ if fd.fs.umounted {
+ ready |= waiter.EventErr
+ return ready & mask
+ }
+
+ // FD is always writable.
+ ready |= waiter.EventOut
if !fd.queue.Empty() {
// Have reqs available, FD is readable.
ready |= waiter.EventIn
@@ -365,7 +383,7 @@ func (fd *DeviceFD) EventUnregister(e *waiter.Entry) {
// Seek implements vfs.FileDescriptionImpl.Seek.
func (fd *DeviceFD) Seek(ctx context.Context, offset int64, whence int32) (int64, error) {
// Operations on /dev/fuse don't make sense until a FUSE filesystem is mounted.
- if !fd.mounted {
+ if fd.fs == nil {
return 0, syserror.EPERM
}
@@ -391,19 +409,20 @@ func (fd *DeviceFD) sendResponse(ctx context.Context, fut *futureResponse) error
return nil
}
-// sendError sends an error response to the waiting task (if any).
-func (fd *DeviceFD) sendError(ctx context.Context, errno int32, req *Request) error {
+// sendError sends an error response to the waiting task (if any) by calling sendResponse().
+func (fd *DeviceFD) sendError(ctx context.Context, errno int32, unique linux.FUSEOpID) error {
// Return the error to the calling task.
outHdrLen := uint32((*linux.FUSEHeaderOut)(nil).SizeBytes())
respHdr := linux.FUSEHeaderOut{
Len: outHdrLen,
Error: errno,
- Unique: req.hdr.Unique,
+ Unique: unique,
}
fut, ok := fd.completions[respHdr.Unique]
if !ok {
- // Server sent us a response for a request we never sent?
+ // A response for a request we never sent,
+ // or for which we already received a reply (e.g. aborted).
return syserror.EINVAL
}
delete(fd.completions, respHdr.Unique)
diff --git a/pkg/sentry/fsimpl/fuse/dev_test.go b/pkg/sentry/fsimpl/fuse/dev_test.go
index 936683454..3da8b469b 100644
--- a/pkg/sentry/fsimpl/fuse/dev_test.go
+++ b/pkg/sentry/fsimpl/fuse/dev_test.go
@@ -35,10 +35,6 @@ import (
// will simply echo the payload back with the appropriate headers.
const echoTestOpcode linux.FUSEOpcode = 1000
-type testPayload struct {
- data uint32
-}
-
// TestFUSECommunication tests that the communication layer between the Sentry and the
// FUSE server daemon works as expected.
func TestFUSECommunication(t *testing.T) {
diff --git a/pkg/sentry/fsimpl/fuse/fusefs.go b/pkg/sentry/fsimpl/fuse/fusefs.go
index 30725182a..f4ed73c12 100644
--- a/pkg/sentry/fsimpl/fuse/fusefs.go
+++ b/pkg/sentry/fsimpl/fuse/fusefs.go
@@ -29,6 +29,7 @@ import (
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
"gvisor.dev/gvisor/pkg/sentry/vfs"
"gvisor.dev/gvisor/pkg/syserror"
+ "gvisor.dev/gvisor/pkg/waiter"
"gvisor.dev/gvisor/tools/go_marshal/marshal"
)
@@ -82,6 +83,9 @@ type filesystem struct {
// opts is the options the fusefs is initialized with.
opts *filesystemOptions
+
+ // umounted is true if filesystem.Release() has been called.
+ umounted bool
}
// Name implements vfs.FilesystemType.Name.
@@ -221,6 +225,14 @@ func newFUSEFilesystem(ctx context.Context, devMinor uint32, opts *filesystemOpt
// Release implements vfs.FilesystemImpl.Release.
func (fs *filesystem) Release(ctx context.Context) {
+ fs.umounted = true
+ fs.conn.Abort(ctx)
+
+ fs.conn.fd.mu.Lock()
+ // Notify all the waiters on this fd.
+ fs.conn.fd.waitQueue.Notify(waiter.EventIn)
+ fs.conn.fd.mu.Unlock()
+
fs.Filesystem.VFSFilesystem().VirtualFilesystem().PutAnonBlockDevMinor(fs.devMinor)
fs.Filesystem.Release(ctx)
}
diff --git a/pkg/sentry/fsimpl/fuse/utils_test.go b/pkg/sentry/fsimpl/fuse/utils_test.go
new file mode 100644
index 000000000..436322830
--- /dev/null
+++ b/pkg/sentry/fsimpl/fuse/utils_test.go
@@ -0,0 +1,111 @@
+// Copyright 2020 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 fuse
+
+import (
+ "testing"
+
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/sentry/fsimpl/testutil"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/usermem"
+ "gvisor.dev/gvisor/tools/go_marshal/marshal"
+)
+
+func setup(t *testing.T) *testutil.System {
+ k, err := testutil.Boot()
+ if err != nil {
+ t.Fatalf("Error creating kernel: %v", err)
+ }
+
+ ctx := k.SupervisorContext()
+ creds := auth.CredentialsFromContext(ctx)
+
+ k.VFS().MustRegisterFilesystemType(Name, &FilesystemType{}, &vfs.RegisterFilesystemTypeOptions{
+ AllowUserList: true,
+ AllowUserMount: true,
+ })
+
+ mntns, err := k.VFS().NewMountNamespace(ctx, creds, "", "tmpfs", &vfs.GetFilesystemOptions{})
+ if err != nil {
+ t.Fatalf("NewMountNamespace(): %v", err)
+ }
+
+ return testutil.NewSystem(ctx, t, k.VFS(), mntns)
+}
+
+// newTestConnection creates a fuse connection that the sentry can communicate with
+// and the FD for the server to communicate with.
+func newTestConnection(system *testutil.System, k *kernel.Kernel, maxActiveRequests uint64) (*connection, *vfs.FileDescription, error) {
+ vfsObj := &vfs.VirtualFilesystem{}
+ fuseDev := &DeviceFD{}
+
+ if err := vfsObj.Init(system.Ctx); err != nil {
+ return nil, nil, err
+ }
+
+ vd := vfsObj.NewAnonVirtualDentry("genCountFD")
+ defer vd.DecRef(system.Ctx)
+ if err := fuseDev.vfsfd.Init(fuseDev, linux.O_RDWR|linux.O_CREAT, vd.Mount(), vd.Dentry(), &vfs.FileDescriptionOptions{}); err != nil {
+ return nil, nil, err
+ }
+
+ fsopts := filesystemOptions{
+ maxActiveRequests: maxActiveRequests,
+ }
+ fs, err := newFUSEFilesystem(system.Ctx, 0, &fsopts, &fuseDev.vfsfd)
+ if err != nil {
+ return nil, nil, err
+ }
+
+ return fs.conn, &fuseDev.vfsfd, nil
+}
+
+type testPayload struct {
+ marshal.StubMarshallable
+ data uint32
+}
+
+// SizeBytes implements marshal.Marshallable.SizeBytes.
+func (t *testPayload) SizeBytes() int {
+ return 4
+}
+
+// MarshalBytes implements marshal.Marshallable.MarshalBytes.
+func (t *testPayload) MarshalBytes(dst []byte) {
+ usermem.ByteOrder.PutUint32(dst[:4], t.data)
+}
+
+// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes.
+func (t *testPayload) UnmarshalBytes(src []byte) {
+ *t = testPayload{data: usermem.ByteOrder.Uint32(src[:4])}
+}
+
+// Packed implements marshal.Marshallable.Packed.
+func (t *testPayload) Packed() bool {
+ return true
+}
+
+// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
+func (t *testPayload) MarshalUnsafe(dst []byte) {
+ t.MarshalBytes(dst)
+}
+
+// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.
+func (t *testPayload) UnmarshalUnsafe(src []byte) {
+ t.UnmarshalBytes(src)
+}