Add separate class for managing zFCP

src/lib/y2s390/zfcp.rb

@@ -0,0 +1,183 @@
+# Copyright (c) [2023] SUSE LLC
+#
+# All Rights Reserved.
+#
+# This program is free software; you can redistribute it and/or modify it
+# under the terms of version 2 of the GNU General Public License as published
+# by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+# more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, contact SUSE LLC.
+#
+# To contact SUSE LLC about this file by physical or electronic mail, you may
+# find current contact information at www.suse.com.
+
+require "yast"
+require "yaml"
+
+module Y2S390
+  # Manager for zFCP devices
+  class ZFCP
+    include Yast
+    include Yast::Logger
+
+    # Detected controllers
+    #
+    # @return [Array<Hash>] keys for each hash:
+    #   "sysfs_bus_id", "resource"
+    attr_reader :controllers
+
+    # Detected LUN disks
+    #
+    # @return [Array<Hash>] keys for each hash:
+    #   "dev_name", "detail", "vendor", "device" and "io".
+    attr_reader :disks
+
+    def initialize
+      @controllers = []
+      @disks = []
+    end
+
+    # Probes the zFCP controllers
+    def probe_controllers
+      make_all_devices_visible
+
+      storage_devices = Yast::SCR.Read(path(".probe.storage"))
+      controllers = storage_devices.select { |i| i["device"] == "zFCP controller" }
+
+      @controllers = controllers.map { |c| c.slice("sysfs_bus_id", "resource") }
+    end
+
+    # Probes the zFCP disks
+    def probe_disks
+      storage_disks = read_mock_disks || Yast::SCR.Read(path(".probe.disk"))
+      zfcp_disks = storage_disks.select { |d| d["driver"] == "zfcp" }
+
+      tapes = Yast::SCR.Read(path(".probe.tape"))
+      scsi_tapes = tapes.select { |t| t["bus"] == "SCSI" }
+
+      disks = zfcp_disks + scsi_tapes
+
+      @disks = disks.map { |d| d.slice("dev_name", "detail", "vendor", "device", "io") }
+    end
+
+    # Runs the command for activating a controller
+    #
+    # @note All LUNs are automatically activated if "allow_lun_scan" is active, see
+    #   https://www.ibm.com/docs/en/linux-on-systems?topic=wsd-configuring-devices.
+    #
+    # @param channel [String] E.g., "0.0.fa00"
+    # @return [Hash] See {#run}. The exit code corresponds to the chzdev one.
+    def activate_controller(channel)
+      command = format("/sbin/zfcp_host_configure '%s' %d", channel, 1)
+      run(command)
+    end
+
+    # Whether the controller is activated
+    #
+    # @param channel [String] E.g., "0.0.fa00"
+    # @return [Boolean]
+    def activated_controller?(channel)
+      controller = controllers.find { |c| c["sysfs_bus_id"] == channel }
+      return false unless controller
+
+      io = controller.dig("resource", "io") || []
+      io.any? { |i| i["active"] }
+    end
+
+    # Runs the command for activating a zFCP disk
+    #
+    # @param channel [String] E.g., "0.0.fa00"
+    # @param wwpn [String] E.g., "0x500507630708d3b3"
+    # @param lun [String] E.g., "0x0013000000000000"
+    #
+    # @return [Hash] See {#run}. The exit code corresponds to the chzdev one.
+    def activate_disk(channel, wwpn, lun)
+      command = format("/sbin/zfcp_disk_configure '%s' '%s' '%s' %d", channel, wwpn, lun, 1)
+      run(command)
+    end
+
+    # Runs the command for deactivating a zFCP disk
+    #
+    # @note Deactivate fails if "allow_lun_scan" is active, see
+    #   https://www.ibm.com/docs/en/linux-on-systems?topic=wsd-configuring-devices.
+    #
+    # @param channel [String] E.g., "0.0.fa00"
+    # @param wwpn [String] E.g., "0x500507630708d3b3"
+    # @param lun [String] E.g., "0x0013000000000000"
+    #
+    # @return [Hash] See {#run}. The exit code corresponds to the chzdev one.
+    def deactivate_disk(channel, wwpn, lun)
+      command = format("/sbin/zfcp_disk_configure '%s' '%s' '%s' %d", channel, wwpn, lun, 0)
+      run(command)
+    end
+
+    # Runs the command for finding WWPNs
+    #
+    # @param channel [String] E.g., "0.0.fa00"
+    # @return [Hash] See {#run}
+    def find_wwpns(channel)
+      command = format("zfcp_san_disc -b '%s' -W", channel)
+      run(command)
+    end
+
+    # Runs the command for finding LUNs
+    #
+    # @param channel [String] E.g., "0.0.fa00"
+    # @param wwpn [String] E.g., "0x500507630708d3b3"
+    #
+    # @return [Hash] See {#run}
+    def find_luns(channel, wwpn)
+      command = format("zfcp_san_disc -b '%s' -p '%s' -L", channel, wwpn)
+      run(command)
+    end
+
+  private
+
+    # Sets all detected controllers as visible
+    def make_all_devices_visible
+      # Checking if it is a z/VM and evaluating all FCP controllers in order to activate
+      output = run("/sbin/vmcp q v fcp")
+      return if output["exit"] != 0
+
+      fcp_lines = output["stdout"].map(&:split).select { |l| l.first == "FCP" }
+      devices = fcp_lines.map { |l| l[1].downcase }
+
+      # Remove all needed devices from CIO device driver blacklist in order to see it
+      devices.each do |device|
+        log.info "Removing #{device} from the CIO device driver blacklist"
+        run("/sbin/cio_ignore -r #{device}")
+      end
+    end
+
+    # Runs the given command
+    #
+    # @param command [String]
+    # @return [Hash] Output of the command which has these keys: "exit", "stdout", "stderr".
+    def run(command)
+      Yast::SCR.Execute(path(".target.bash_output"), command).tap do |output|
+        log.info("command #{command} output #{output}")
+
+        output["exit"] = output["exit"].to_i
+        output["stdout"] = output["stdout"].split("\n").reject(&:empty?)
+      end
+    end
+
+    # Reads the mock disks from the YAML file pointed by YAST2_S390_PROBE_DISK
+    #
+    # Suggestion: YAST2_S390_PROBE_DISK=test/data/probe_disk.yml rake run[zfcp]
+    #
+    # @return [Array<Hash>, nil] List of mocked LUN disks or nil if no file found
+    def read_mock_disks
+      mock_filename = ENV["YAST2_S390_PROBE_DISK"]
+      return nil unless mock_filename
+
+      YAML.safe_load(File.read(mock_filename))
+    end
+  end
+end