sanlock: fix locking for readonly devices

Add ignore param for readonly and shared disk in sanlock

AUTHORS

@@ -237,6 +237,7 @@ Patches have also been contributed by:
   Eugen Feller         <eugen.feller@inria.fr>
   Dmitry Guryanov      <dguryanov@parallels.com>
   William Jon McCann   <william.jon.mccann@gmail.com>
+  David Weber          <wb@munzinger.de>
 
   [....send patches to get your name here....]
 

src/locking/libvirt_sanlock.aug

@@ -21,6 +21,7 @@ module Libvirt_sanlock =
              | bool_entry "auto_disk_leases"
              | int_entry "host_id"
              | bool_entry "require_lease_for_disks"
+             | bool_entry "ignore_readonly_and_shared_disks"
    let comment = [ label "#comment" . del /#[ \t]*/ "# " .  store /([^ \t\n][^\n]*)?/ . del /\n/ "\n" ]
    let empty = [ label "#empty" . eol ]
 

src/locking/lock_driver_sanlock.c

 /*
  * lock_driver_sanlock.c: A lock driver for Sanlock
  *
- * Copyright (C) 2010-2011 Red Hat, Inc.
+ * Copyright (C) 2010-2012 Red Hat, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -65,6 +65,7 @@ struct _virLockManagerSanlockDriver {
     bool requireLeaseForDisks;
     int hostID;
     bool autoDiskLease;
+    bool ignoreReadonlyShared;
     char *autoDiskLeasePath;
 };
 
@@ -114,6 +115,10 @@ static int virLockManagerSanlockLoadConfig(const char *configFile)
     CHECK_TYPE("auto_disk_leases", VIR_CONF_LONG);
     if (p) driver->autoDiskLease = p->l;
 
+    p = virConfGetValue(conf, "ignore_readonly_and_shared_disks");
+    CHECK_TYPE("ignore_readonly_and_shared_disks", VIR_CONF_LONG);
+    if (p) driver->ignoreReadonlyShared = p->l;
+
     p = virConfGetValue(conf, "disk_lease_dir");
     CHECK_TYPE("disk_lease_dir", VIR_CONF_STRING);
     if (p && p->str) {
@@ -625,6 +630,12 @@ static int virLockManagerSanlockAddResource(virLockManagerPtr lock,
         return -1;
     }
 
+    if ((flags & (VIR_LOCK_MANAGER_RESOURCE_READONLY |
+                  VIR_LOCK_MANAGER_RESOURCE_SHARED)) &&
+        driver->ignoreReadonlyShared) {
+            return 0;
+    }
+
     if (flags & VIR_LOCK_MANAGER_RESOURCE_READONLY) {
         virLockError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
                      _("Readonly leases are not supported"));

src/locking/sanlock.conf

@@ -52,3 +52,10 @@
 # to enabled, otherwise it defaults to disabled.
 #
 #require_lease_for_disks = 1
+
+#
+# Enable this flag to have sanlock ignore readonly and shared disks.
+# If disabled, then this rejects attempts to share resources until
+# sanlock gains support for shared locks.
+#
+#ignore_readonly_and_shared_disks = 1

src/locking/test_libvirt_sanlock.aug

@@ -4,6 +4,7 @@ module Test_libvirt_sanlock =
 disk_lease_dir = \"/var/lib/libvirt/sanlock\"
 host_id = 1
 require_lease_for_disks = 1
+ignore_readonly_and_shared_disks = 1
 "
 
    test Libvirt_sanlock.lns get conf =
@@ -11,3 +12,4 @@ require_lease_for_disks = 1
 { "disk_lease_dir" = "/var/lib/libvirt/sanlock" }
 { "host_id" = "1" }
 { "require_lease_for_disks" = "1" }
+{ "ignore_readonly_and_shared_disks" = "1" }