From 84e0ee13c8de454c1e6809e2089a4d09d53f9794 Mon Sep 17 00:00:00 2001
From: Julio Montes <julio.montes@intel.com>
Date: Fri, 20 Mar 2020 14:12:38 +0000
Subject: [PATCH] virtcontainers: reimplement `createBlockDevices`

Reimplement `createBlockDevices` to identify possible volumes that can be
used as pmem devices

Signed-off-by: Julio Montes <julio.montes@intel.com>
---
 virtcontainers/container.go              | 31 +++++++++++++++++++++---
 virtcontainers/device/manager/manager.go | 16 +++++++-----
 2 files changed, 37 insertions(+), 10 deletions(-)

diff --git a/virtcontainers/container.go b/virtcontainers/container.go
index bfb32e9a42..4ba7ee2e3a 100644
--- a/virtcontainers/container.go
+++ b/virtcontainers/container.go
@@ -643,6 +643,11 @@ func filterDevices(c *Container, devices []ContainerDevice) (ret []ContainerDevi
 }
 
 func (c *Container) createBlockDevices() error {
+	if !c.checkBlockDeviceSupport() {
+		c.Logger().Warn("Block device not supported")
+		return nil
+	}
+
 	// iterate all mounts and create block device if it's block based.
 	for i, m := range c.mounts {
 		if len(m.BlockDeviceID) > 0 || m.Type != "bind" {
@@ -657,18 +662,36 @@ func (c *Container) createBlockDevices() error {
 			return fmt.Errorf("stat %q failed: %v", m.Source, err)
 		}
 
+		var di *config.DeviceInfo
+		var err error
+
 		// Check if mount is a block device file. If it is, the block device will be attached to the host
 		// instead of passing this as a shared mount.
-		if c.checkBlockDeviceSupport() && stat.Mode&unix.S_IFBLK == unix.S_IFBLK {
-			b, err := c.sandbox.devManager.NewDevice(config.DeviceInfo{
+		if stat.Mode&unix.S_IFBLK == unix.S_IFBLK {
+			di = &config.DeviceInfo{
 				HostPath:      m.Source,
 				ContainerPath: m.Destination,
 				DevType:       "b",
 				Major:         int64(unix.Major(stat.Rdev)),
 				Minor:         int64(unix.Minor(stat.Rdev)),
-			})
+			}
+			// check whether source can be used as a pmem device
+		} else if di, err = config.PmemDeviceInfo(m.Source, m.Destination); err != nil {
+			c.Logger().WithError(err).
+				WithField("mount-source", m.Source).
+				Debug("no loop device")
+		}
+
+		if err == nil && di != nil {
+			b, err := c.sandbox.devManager.NewDevice(*di)
+
 			if err != nil {
-				return fmt.Errorf("device manager failed to create new device for %q: %v", m.Source, err)
+				// Do not return an error, try to create
+				// devices for other mounts
+				c.Logger().WithError(err).WithField("mount-source", m.Source).
+					Error("device manager failed to create new device")
+				continue
+
 			}
 
 			c.mounts[i].BlockDeviceID = b.DeviceID()
diff --git a/virtcontainers/device/manager/manager.go b/virtcontainers/device/manager/manager.go
index 531cbd1ddb..6a2b665a5e 100644
--- a/virtcontainers/device/manager/manager.go
+++ b/virtcontainers/device/manager/manager.go
@@ -98,11 +98,15 @@ func (dm *deviceManager) findDeviceByMajorMinor(major, minor int64) api.Device {
 
 // createDevice creates one device based on DeviceInfo
 func (dm *deviceManager) createDevice(devInfo config.DeviceInfo) (dev api.Device, err error) {
-	path, err := config.GetHostPathFunc(devInfo, dm.vhostUserStoreEnabled, dm.vhostUserStorePath)
-	if err != nil {
-		return nil, err
+	// pmem device may points to block devices or raw files,
+	// do not change its HostPath.
+	if !devInfo.Pmem {
+		path, err := config.GetHostPathFunc(devInfo, dm.vhostUserStoreEnabled, dm.vhostUserStorePath)
+		if err != nil {
+			return nil, err
+		}
+		devInfo.HostPath = path
 	}
-	devInfo.HostPath = path
 
 	defer func() {
 		if err == nil {
@@ -119,7 +123,7 @@ func (dm *deviceManager) createDevice(devInfo config.DeviceInfo) (dev api.Device
 	if devInfo.ID, err = dm.newDeviceID(); err != nil {
 		return nil, err
 	}
-	if isVFIO(path) {
+	if isVFIO(devInfo.HostPath) {
 		return drivers.NewVFIODevice(&devInfo), nil
 	} else if isVhostUserBlk(devInfo) {
 		if devInfo.DriverOptions == nil {
@@ -134,7 +138,7 @@ func (dm *deviceManager) createDevice(devInfo config.DeviceInfo) (dev api.Device
 		devInfo.DriverOptions["block-driver"] = dm.blockDriver
 		return drivers.NewBlockDevice(&devInfo), nil
 	} else {
-		deviceLogger().WithField("device", path).Info("Device has not been passed to the container")
+		deviceLogger().WithField("device", devInfo.HostPath).Info("Device has not been passed to the container")
 		return drivers.NewGenericDevice(&devInfo), nil
 	}
 }