Support multiple local SSD controllers. (#39)

Two changes have been included in this commit:
1. Extended `google_nvme_id` script to handle multi-controllers for local SSD.
2. Added new match rules for local SSD multi-controllers in 65-gce-disk-naming.rules

Co-authored-by: Fan Yang <fanyanf@google.com>

src/lib/udev/google_nvme_id

@@ -13,18 +13,21 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Used to generate symlinks for PD-NVMe devices using the disk names reported by
-# the metadata server
+# Used to generate symlinks for NVMe devices (both local SSD and
+# persistent disk) using the disk names reported by the metadata server.
 
 # Locations of the script's dependencies
 readonly nvme_cli_bin=/usr/sbin/nvme
 
 # Bash regex to parse device paths and controller identification
+readonly PD_CONTROLLER_REGEX="nvme_card-pd"
+readonly SSD_CONTROLLER_REGEX="nvme_card[0-9]*"
+readonly CONTROLLER_NUMBER_REGEX="nvme_card([[:digit:]]+)"
 readonly NAMESPACE_NUMBER_REGEX="/dev/nvme[[:digit:]]+n([[:digit:]]+).*"
 readonly PARTITION_NUMBER_REGEX="/dev/nvme[[:digit:]]+n[[:digit:]]+p([[:digit:]]+)"
 readonly PD_NVME_REGEX="sn[[:space:]]+:[[:space]]+nvme_card-pd"
 
-# Globals used to generate the symlinks for a PD-NVMe disk.  These are populated
+# Globals used to generate the symlinks for a NVMe disk.  These are populated
 # by the identify_pd_disk function and exported for consumption by udev rules.
 ID_SERIAL=''
 ID_SERIAL_SHORT=''
@@ -124,6 +127,28 @@ function get_partition_number() {
   return 0
 }
 
+#######################################
+# Retrieves the controller number from the device model if it exists
+# Globals:
+#   None
+# Arguments:
+#   The NVMe device model (nvme_card or nvme_card1/2/3/...)
+# Outputs:
+#   The controller id/number
+#######################################
+function get_controller_number() {
+  local dev_model="$1"
+  local controller_number
+  if [[ "$dev_model" =~ $CONTROLLER_NUMBER_REGEX ]]; then
+    controller_number="${BASH_REMATCH[1]}"
+    echo "$controller_number"
+  else
+    # if it's 'nvme_card', echo 0. This is for backward compatibility.
+    echo '0'
+  fi
+  return 0
+}
+
 #######################################
 # Generates a symlink for a PD-NVMe device using the metadata's disk name.
 # Primarily used for testing but can be used if the script is directly invoked.
@@ -152,7 +177,7 @@ function gen_symlink() {
 # Arguments:
 #   The device path for the disk
 # Returns:
-#   0 on success and 1 if an error occurrs
+#   0 on success and 1 if an error occurs
 #######################################
 function identify_pd_disk() {
   local dev_path="$1"
@@ -167,6 +192,35 @@ function identify_pd_disk() {
   return 0
 }
 
+#######################################
+# Populates the ID_* global variables with a disk's device name and namespace
+# Globals:
+#   Populates ID_SERIAL_SHORT, and ID_SERIAL
+# Arguments:
+#   The device path for the disk
+# Returns:
+#   0 on success and 1 if an error occurs
+#######################################
+function identify_local_ssd_disk() {
+  local dev_model="$1"
+  local dev_path="$2"
+  local controller_number
+  controller_number="$(get_controller_number "$dev_model")"
+  if [[ $? -ne 0 ]]; then
+    return 1
+  fi
+
+  local namespace_number
+  namespace_number="$(get_namespace_number "$dev_path")"
+  if [[ $? -ne 0 ]]; then
+    return 1
+  fi
+
+  ID_SERIAL_SHORT="local-nvme-ssd-$(($controller_number+$namespace_number-1))"
+  ID_SERIAL="Google_EphemeralDisk_${ID_SERIAL_SHORT}"
+  return 0
+}
+
 function print_help_message() {
   echo "Usage: google_nvme_id [-s] [-h] -d device_path"
   echo "  -d <device_path> (Required): Specifies the path to generate a name"
@@ -218,18 +272,23 @@ script as root/with sudo)."
   # Detect the type of attached nvme device
   local controller_id
   controller_id=$("$nvme_cli_bin" id-ctrl "$device_path")
-  if [[ ! "$controller_id" =~ nvme_card-pd ]] ; then
-    err "Device is not a PD-NVMe device"
+  if [[ "$controller_id" =~ $PD_CONTROLLER_REGEX ]] ; then
+    # Fill the global variables for the id command for the given disk type
+    # Error messages will be printed closer to error, no need to reprint here
+    identify_pd_disk "$device_path"
+    if [[ $? -ne 0 ]]; then
+      return $?
+    fi
+  elif [[ "$controller_id" =~ $SSD_CONTROLLER_REGEX ]] ; then
+    identify_local_ssd_disk "$controller_id" "$device_path"
+    if [[ $? -ne 0 ]]; then
+      return $?
+    fi
+  else
+    err "Device is not a NVMe device"
     return 1
   fi
 
-  # Fill the global variables for the id command for the given disk type
-  # Error messages will be printed closer to error, no need to reprint here
-  identify_pd_disk "$device_path"
-  if [[ $? -ne 0 ]]; then
-    return $?
-  fi
-
   # Gen symlinks or print out the globals set by the identify command
   if [[ "$opt_gen_symlink" == 'true' ]]; then
     gen_symlink "$device_path"

src/lib/udev/rules.d/65-gce-disk-naming.rules

@@ -23,6 +23,8 @@ KERNEL=="sd*|vd*", IMPORT{program}="scsi_id --export --whitelisted -d $tempnode"
 # NVME Local SSD naming
 KERNEL=="nvme*n*", ATTRS{model}=="nvme_card", PROGRAM="/bin/sh -c 'nsid=$$(echo %k|sed -re s/nvme[0-9]+n\([0-9]+\).\*/\\1/); echo $$((nsid-1))'", ENV{ID_SERIAL_SHORT}="local-nvme-ssd-%c"
 KERNEL=="nvme*", ATTRS{model}=="nvme_card", ENV{ID_SERIAL}="Google_EphemeralDisk_$env{ID_SERIAL_SHORT}"
+# Support for local SSD multi-controller
+KERNEL=="nvme*n*", ATTRS{model}=="nvme_card[0-9]*", IMPORT{program}="google_nvme_id -d $tempnode"
 
 # NVME Persistent Disk IO Timeout
 KERNEL=="nvme*n*", ENV{DEVTYPE}=="disk", ATTRS{model}=="nvme_card-pd", ATTR{queue/io_timeout}="4294967295"