Add dracutSetupString() method to ZFCPDiskDevice (#526354).

Collect CCW bus ID, WWPN, and FCP LUN values for zFCP devices when
building the device tree.  Store these in the ZFCPDiskDevice object and
use them to generate the rd_ZFCP= string for dracut.

Expand storage/udev.py with functions to determine if a device is zFCP
and to get arbitrary attribute values.

3 files changed, 62 insertions, 12 deletions

diff --git a/storage/devices.py b/storage/devices.py
index 9fafeb611..9166b6cf6 100644
--- a/storage/devices.py
+++ b/storage/devices.py
@@ -3135,23 +3135,24 @@ class ZFCPDiskDevice(DiskDevice):
     """ A mainframe ZFCP disk. """
     _type = "zfcp"
 
-    def __init__(self, name, size=None, major=None, minor=None,
-                 devnum=None, wwpn=None, fcplun=None,
-                 parents=None, sysfsPath=''):
-        self.devnum = devnum
-        self.wwpn = wwpn
-        self.fcplun = fcplun
-        name = "zfcp://%s/%s/%s" % (self.devnum, self.wwpn, self.fcplun)
-        DiskDevice.__init__(self, name, size=size,
-                            major=major, minor=minor,
-                            parents=parents, sysfsPath=sysfsPath)
+    def __init__(self, name, **kwargs):
+        self.hba_id = kwargs.get("hba_id")
+        self.wwpn = kwargs.get("wwpn")
+        self.fcp_lun = kwargs.get("fcp_lun")
+        name = "zfcp://%s/%s/%s" % (self.hba_id, self.wwpn, self.fcplun,)
+        DiskDevice.__init__(self, name, **kwargs)
 
     def __str__(self):
         s = DiskDevice.__str__(self)
-        s += ("  devnum = %(devnum)s  wwpn = %(wwpn)s  fcplun = %(fcplun)s" %
-              {"devnum": self.devnum, "wwpn": self.wwpn, "fcplun": self.fcplun})
+        s += ("  hba_id = %(hba_id)s  wwpn = %(wwpn)s  fcp_lun = %(fcp_lun)s" %
+              {"hba_id": self.hba_id,
+               "wwpn": self.wwpn,
+               "fcp_lun": self.fcp_lun})
         return s
 
+    def dracutSetupString(self):
+        return "rd_ZFCP=%s,%s,%s" % (self.hba_id, self.wwpn, self.fcp_lun,)
+
 
 class DASDDevice(DiskDevice):
     """ A mainframe DASD. """
diff --git a/storage/devicetree.py b/storage/devicetree.py
index d35580434..d117f4c79 100644
--- a/storage/devicetree.py
+++ b/storage/devicetree.py
@@ -1193,6 +1193,13 @@ class DeviceTree(object):
         elif udev_device_is_dasd(info):
             diskType = DASDDevice
             log.debug("%s is a dasd device" % name)
+        elif udev_device_is_zfcp(info):
+            diskType = ZFCPDiskDevice
+
+            for attr in ['hba_id', 'wwpn', 'fcp_lun']:
+                kwargs[attr] = udev_device_get_zfcp_attribute(info, attr=attr)
+
+            log.debug("%s is a zfcp device" % name)
         else:
             diskType = DiskDevice
             log.debug("%s is a disk" % name)
diff --git a/storage/udev.py b/storage/udev.py
index d051157b5..bd89007bc 100644
--- a/storage/udev.py
+++ b/storage/udev.py
@@ -165,6 +165,48 @@ def udev_device_is_dasd(info):
     else:
         return False
 
+def udev_device_is_zfcp(info):
+    """ Return True if the device is a zfcp device. """
+    if info.get("DEVTYPE") != "disk":
+        return False
+
+    subsystem = "/sys" + info.get("sysfs_path")
+
+    while True:
+        topdir = os.path.realpath(os.path.dirname(subsystem))
+        driver = "%s/driver" % (topdir,)
+
+        if os.path.islink(driver):
+            subsystemname = os.path.basename(os.readlink(subsystem))
+            drivername = os.path.basename(os.readlink(driver))
+
+            if subsystemname == 'ccw' and drivername == 'zfcp':
+                return True
+
+        newsubsystem = os.path.dirname(topdir)
+
+        if newsubsystem == topdir:
+            break
+
+        subsystem = newsubsystem + "/subsystem"
+
+    return False
+
+def udev_device_get_zfcp_attribute(info, attr=None):
+    """ Return the value of the specified attribute of the zfcp device. """
+    if not attr:
+        log.debug("udev_device_get_zfcp_attribute() called with attr=None")
+        return None
+
+    attribute = "/sys%s/devices/%s" % (info.get("sysfs_path"), attr,)
+    attribute = os.path.realpath(attribute)
+
+    if not os.path.isfile(attribute):
+        log.warning("%s is not a valid zfcp attribute" % (attribute,))
+        return None
+
+    return open(attribute, "r").read().strip()
+
 def udev_device_is_cdrom(info):
     """ Return True if the device is an optical drive. """
     # FIXME: how can we differentiate USB drives from CD-ROM drives?