From f889f1f95736a05fad5eb993f402b9d8fa8387e9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fabiano=20Fid=C3=AAncio?= <fabiano.fidencio@intel.com>
Date: Thu, 3 Mar 2022 12:18:43 +0100
Subject: [PATCH] clh: introduce supportsSharedFS()
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supportsSharedFS() is a new method to be used to ensure that no SharedFS
specifics are called when, for a reason or another, Cloud Hypervisor is
in a mode where SharedFSs are not supported.

Signed-off-by: Fabiano Fidêncio <fabiano.fidencio@intel.com>
---
 src/runtime/virtcontainers/clh.go | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/src/runtime/virtcontainers/clh.go b/src/runtime/virtcontainers/clh.go
index d609d9ea1f..6bdc917edc 100644
--- a/src/runtime/virtcontainers/clh.go
+++ b/src/runtime/virtcontainers/clh.go
@@ -199,6 +199,11 @@ func (clh *cloudHypervisor) setConfig(config *HypervisorConfig) error {
 }
 
 func (clh *cloudHypervisor) createVirtiofsDaemon(sharedPath string) (VirtiofsDaemon, error) {
+	if !clh.supportsSharedFS() {
+		clh.Logger().Info("SharedFS is not supported")
+		return nil, nil
+	}
+
 	virtiofsdSocketPath, err := clh.virtioFsSocketPath(clh.id)
 	if err != nil {
 		return nil, err
@@ -235,6 +240,11 @@ func (clh *cloudHypervisor) createVirtiofsDaemon(sharedPath string) (VirtiofsDae
 }
 
 func (clh *cloudHypervisor) setupVirtiofsDaemon(ctx context.Context) error {
+	if !clh.supportsSharedFS() {
+		clh.Logger().Info("SharedFS is not supported")
+		return nil
+	}
+
 	if clh.config.SharedFS == config.Virtio9P {
 		return errors.New("cloud-hypervisor only supports virtio based file sharing")
 	}
@@ -258,6 +268,11 @@ func (clh *cloudHypervisor) setupVirtiofsDaemon(ctx context.Context) error {
 }
 
 func (clh *cloudHypervisor) stopVirtiofsDaemon(ctx context.Context) (err error) {
+	if !clh.supportsSharedFS() {
+		clh.Logger().Info("SharedFS is not supported")
+		return nil
+	}
+
 	if clh.state.VirtiofsDaemonPid == 0 {
 		clh.Logger().Warn("The virtiofsd had stopped")
 		return nil
@@ -274,6 +289,11 @@ func (clh *cloudHypervisor) stopVirtiofsDaemon(ctx context.Context) (err error)
 }
 
 func (clh *cloudHypervisor) loadVirtiofsDaemon(sharedPath string) (VirtiofsDaemon, error) {
+	if !clh.supportsSharedFS() {
+		clh.Logger().Info("SharedFS is not supported")
+		return nil, nil
+	}
+
 	virtiofsdSocketPath, err := clh.virtioFsSocketPath(clh.id)
 	if err != nil {
 		return nil, err
@@ -291,6 +311,12 @@ func (clh *cloudHypervisor) nydusdAPISocketPath(id string) (string, error) {
 	return utils.BuildSocketPath(clh.config.VMStorePath, id, nydusdAPISock)
 }
 
+func (clh *cloudHypervisor) supportsSharedFS() bool {
+	caps := clh.Capabilities(clh.ctx)
+
+	return caps.IsFsSharingSupported()
+}
+
 func (clh *cloudHypervisor) enableProtection() error {
 	protection, err := availableGuestProtection()
 	if err != nil {