devmapper: Log fstype and mount options during mount error

Right now we only log source and destination (and demsg) if mount operation
fails. fstype and mount options are available easily. It probably is a good
idea to log these as well. Especially sometimes failures can happen due to
mount options.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>

daemon/graphdriver/devmapper/deviceset.go

@@ -1201,7 +1201,7 @@ func (devices *DeviceSet) growFS(info *devInfo) error {
 	options = joinMountOptions(options, devices.mountOptions)
 
 	if err := mount.Mount(info.DevName(), fsMountPoint, devices.BaseDeviceFilesystem, options); err != nil {
-		return fmt.Errorf("Error mounting '%s' on '%s': %s\n%v", info.DevName(), fsMountPoint, err, string(dmesg.Dmesg(256)))
+		return fmt.Errorf("Error mounting '%s' on '%s' (fstype='%s' options='%s'): %s\n%v", info.DevName(), fsMountPoint, devices.BaseDeviceFilesystem, options, err, string(dmesg.Dmesg(256)))
 	}
 
 	defer unix.Unmount(fsMountPoint, unix.MNT_DETACH)
@@ -2392,7 +2392,7 @@ func (devices *DeviceSet) MountDevice(hash, path, mountLabel string) error {
 	options = joinMountOptions(options, label.FormatMountLabel("", mountLabel))
 
 	if err := mount.Mount(info.DevName(), path, fstype, options); err != nil {
-		return fmt.Errorf("devmapper: Error mounting '%s' on '%s': %s\n%v", info.DevName(), path, err, string(dmesg.Dmesg(256)))
+		return fmt.Errorf("devmapper: Error mounting '%s' on '%s' (fstype='%s' options='%s'): %s\n%v", info.DevName(), path, fstype, options, err, string(dmesg.Dmesg(256)))
 	}
 
 	if fstype == "xfs" && devices.xfsNospaceRetries != "" {