Add support for locking based on SCSI volume ID

src/locking/libvirt_lockd.aug

@@ -21,6 +21,7 @@ module Libvirt_lockd =
              | bool_entry "require_lease_for_disks"
              | str_entry "file_lockspace_dir"
 	     | str_entry "lvm_lockspace_dir"
+	     | str_entry "scsi_lockspace_dir"
    let comment = [ label "#comment" . del /#[ \t]*/ "# " .  store /([^ \t\n][^\n]*)?/ . del /\n/ "\n" ]
    let empty = [ label "#empty" . eol ]
 

src/locking/lock_driver_lockd.c

@@ -74,6 +74,7 @@ struct _virLockManagerLockDaemonDriver {
 
     char *fileLockSpaceDir;
     char *lvmLockSpaceDir;
+    char *scsiLockSpaceDir;
 };
 
 static virLockManagerLockDaemonDriverPtr driver = NULL;
@@ -146,6 +147,17 @@ static int virLockManagerLockDaemonLoadConfig(const char *configFile)
         }
     }
 
+    p = virConfGetValue(conf, "scsi_lockspace_dir");
+    CHECK_TYPE("scsi_lockspace_dir", VIR_CONF_STRING);
+    if (p && p->str) {
+        VIR_FREE(driver->scsiLockSpaceDir);
+        if (!(driver->scsiLockSpaceDir = strdup(p->str))) {
+            virReportOOMError();
+            virConfFree(conf);
+            return -1;
+        }
+    }
+
     p = virConfGetValue(conf, "require_lease_for_disks");
     CHECK_TYPE("require_lease_for_disks", VIR_CONF_LONG);
     if (p)
@@ -387,6 +399,10 @@ static int virLockManagerLockDaemonInit(unsigned int version,
         if (driver->lvmLockSpaceDir &&
             virLockManagerLockDaemonSetupLockspace(driver->lvmLockSpaceDir) < 0)
             goto error;
+
+        if (driver->scsiLockSpaceDir &&
+            virLockManagerLockDaemonSetupLockspace(driver->scsiLockSpaceDir) < 0)
+            goto error;
     }
 
     return 0;
@@ -581,6 +597,23 @@ static int virLockManagerLockDaemonAddResource(virLockManagerPtr lock,
             /* Fallback to generic non-block code */
         }
 
+        if (STRPREFIX(name, "/dev") &&
+            driver->scsiLockSpaceDir) {
+            VIR_DEBUG("Trying to find an SCSI ID for %s", name);
+            if (virStorageFileGetSCSIKey(name, &newName) < 0)
+                goto error;
+
+            if (newName) {
+                VIR_DEBUG("Got an SCSI ID %s for %s", newName, name);
+                if (!(newLockspace = strdup(driver->scsiLockSpaceDir)))
+                    goto no_memory;
+                autoCreate = true;
+                break;
+            }
+            virResetLastError();
+            /* Fallback to generic non-block code */
+        }
+
         if (driver->fileLockSpaceDir) {
             if (!(newLockspace = strdup(driver->fileLockSpaceDir)))
                 goto no_memory;

src/locking/lockd.conf

@@ -52,3 +52,17 @@
 # storage.
 #
 #lvm_lockspace_dir = "/var/lib/libvirt/lockd/lvmvolumes"
+
+
+#
+# When using SCSI volumes that can be visible across
+# multiple, it is desirable to do locking based on
+# the unique UUID associated with each volume, instead
+# of their paths. Setting this path causes libvirt to
+# do UUID based locking for SCSI.
+#
+# Typically this directory would be located on a shared
+# filesystem visible to all hosts accessing the same
+# storage.
+#
+#scsi_lockspace_dir = "/var/lib/libvirt/lockd/scsivolumes"

src/locking/test_libvirt_lockd.aug.in

@@ -6,3 +6,4 @@ module Test_libvirt_lockd =
 { "require_lease_for_disks" = "1" }
 { "file_lockspace_dir" = "/var/lib/libvirt/lockd/files" }
 { "lvm_lockspace_dir" = "/var/lib/libvirt/lockd/lvmvolumes" }
+{ "scsi_lockspace_dir" = "/var/lib/libvirt/lockd/scsivolumes" }