fuse: fix FUSE_RELEASE reply handling

fix #3963

3 files changed, 2 insertions, 6 deletions

diff --git a/pkg/sentry/fsimpl/fuse/connection.go b/pkg/sentry/fsimpl/fuse/connection.go
index a7402c149..dbc5e1954 100644
--- a/pkg/sentry/fsimpl/fuse/connection.go
+++ b/pkg/sentry/fsimpl/fuse/connection.go
@@ -110,7 +110,7 @@ type connection struct {
 	//
 	// We call the "background" requests in unix term as async requests.
 	// The "async requests" in unix term is our async requests that expect a reply,
-	// i.e. `!requestOptions.noReply`
+	// i.e. `!request.noReply`
 
 	// asyncMu protects the async request fields.
 	asyncMu sync.Mutex
diff --git a/pkg/sentry/fsimpl/fuse/dev.go b/pkg/sentry/fsimpl/fuse/dev.go
index a19544fe9..5539466ff 100644
--- a/pkg/sentry/fsimpl/fuse/dev.go
+++ b/pkg/sentry/fsimpl/fuse/dev.go
@@ -309,10 +309,6 @@ func (fd *DeviceFD) writeLocked(ctx context.Context, src usermem.IOSequence, opt
 
 			fut, ok := fd.completions[hdr.Unique]
 			if !ok {
-				if fut.hdr.Unique == linux.FUSE_RELEASE {
-					// 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,
 				// or for which we already received a reply (e.g. aborted), an unlikely event.
 				return 0, syserror.EINVAL
diff --git a/pkg/sentry/fsimpl/fuse/file.go b/pkg/sentry/fsimpl/fuse/file.go
index 991efcda4..83f2816b7 100644
--- a/pkg/sentry/fsimpl/fuse/file.go
+++ b/pkg/sentry/fsimpl/fuse/file.go
@@ -89,7 +89,7 @@ func (fd *fileDescription) Release(ctx context.Context) {
 		// No way to invoke Call() with an errored request.
 		return
 	}
-	req.noReply = true
+	// The reply will be ignored since no callback is defined in asyncCallBack().
 	conn.CallAsync(kernelTask, req)
 }