[PATCH 12/14] Add support for locking based on LVM volume uuid

["Daniel P. Berrange" <berrange@xxxxxxxxxx>]

From: "Daniel P. Berrange" <berrange@xxxxxxxxxx>

---
 src/locking/lock_driver_lockd.c | 35 ++++++++++++++++++++++++++++++++++-
 src/locking/lockd.conf          | 14 ++++++++++++++
 2 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/src/locking/lock_driver_lockd.c b/src/locking/lock_driver_lockd.c
index aa0f94a..abae52d 100644
--- a/src/locking/lock_driver_lockd.c
+++ b/src/locking/lock_driver_lockd.c
@@ -73,6 +73,7 @@ struct _virLockManagerLockDaemonDriver {
     bool requireLeaseForDisks;
 
     char *fileLockSpaceDir;
+    char *lvmLockSpaceDir;
 };
 
 static virLockManagerLockDaemonDriverPtr driver = NULL;
@@ -134,6 +135,17 @@ static int virLockManagerLockDaemonLoadConfig(const char *configFile)
         }
     }
 
+    p = virConfGetValue(conf, "lvm_lockspace_dir");
+    CHECK_TYPE("lvm_lockspace_dir", VIR_CONF_STRING);
+    if (p && p->str) {
+        VIR_FREE(driver->lvmLockSpaceDir);
+        if (!(driver->lvmLockSpaceDir = 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)
@@ -371,8 +383,11 @@ static int virLockManagerLockDaemonInit(unsigned int version,
         if (driver->fileLockSpaceDir &&
             virLockManagerLockDaemonSetupLockspace(driver->fileLockSpaceDir) < 0)
             goto error;
-    }
 
+        if (driver->lvmLockSpaceDir &&
+            virLockManagerLockDaemonSetupLockspace(driver->lvmLockSpaceDir) < 0)
+            goto error;
+    }
 
     return 0;
 
@@ -546,6 +561,24 @@ static int virLockManagerLockDaemonAddResource(virLockManagerPtr lock,
             return 0;
         }
 
+        /* XXX we should somehow pass in TYPE=BLOCK info
+         * from the domain_lock code, instead of assuming /dev
+         */
+        if (STRPREFIX(name, "/dev") &&
+            driver->lvmLockSpaceDir) {
+            VIR_DEBUG("Trying to find an LVM UUID for %s", name);
+            newName = virStorageFileGetLVMKey(name);
+            if (newName) {
+                VIR_DEBUG("Got an LVM UUID %s for %s", newName, name);
+                if (!(newLockspace = strdup(driver->lvmLockSpaceDir)))
+                    goto no_memory;
+                autoCreate = true;
+                break;
+            }
+            virResetLastError();
+            /* Fallback to generic non-block code */
+        }
+
         if (driver->fileLockSpaceDir) {
             if (!(newLockspace = strdup(driver->fileLockSpaceDir)))
                 goto no_memory;
diff --git a/src/locking/lockd.conf b/src/locking/lockd.conf
index 7545fd9..00f9b49 100644
--- a/src/locking/lockd.conf
+++ b/src/locking/lockd.conf
@@ -38,3 +38,17 @@
 # storage.
 #
 #file_lockspace_dir = "/var/lib/libvirt/lockd/files"
+
+
+#
+# When using LVM 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 LVM.
+#
+# Typically this directory would be located on a shared
+# filesystem visible to all hosts accessing the same
+# storage.
+#
+#lvm_lockspace_dir = "/var/lib/libvirt/lockd/lvmvolumes"
-- 
1.7.11.7

--
libvir-list mailing list
libvir-list@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/libvir-list