[libvirt] [PATCH v3 10/28] lock_driver_lockd: Introduce VIR_LOCK_SPACE_PROTOCOL_ACQUIRE_RESOURCE_METADATA flag

[Michal Privoznik]

This flag causes virtlockd to use different offset when locking
the file.

Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
---
 src/locking/lock_daemon_dispatch.c | 10 ++++++++--
 src/locking/lock_driver_lockd.c    |  3 ++-
 src/locking/lock_driver_lockd.h    |  1 +
 3 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/locking/lock_daemon_dispatch.c b/src/locking/lock_daemon_dispatch.c
index 10248ec0b5..a683ad3d6b 100644
--- a/src/locking/lock_daemon_dispatch.c
+++ b/src/locking/lock_daemon_dispatch.c
@@ -37,6 +37,9 @@ VIR_LOG_INIT("locking.lock_daemon_dispatch");
 
 #include "lock_daemon_dispatch_stubs.h"
 
+#define DEFAULT_OFFSET 0
+#define METADATA_OFFSET 1
+
 static int
 virLockSpaceProtocolDispatchAcquireResource(virNetServerPtr server ATTRIBUTE_UNUSED,
                                             virNetServerClientPtr client,
@@ -50,13 +53,14 @@ virLockSpaceProtocolDispatchAcquireResource(virNetServerPtr server ATTRIBUTE_UNU
         virNetServerClientGetPrivateData(client);
     virLockSpacePtr lockspace;
     unsigned int newFlags;
-    off_t start = 0;
+    off_t start = DEFAULT_OFFSET;
     off_t len = 1;
 
     virMutexLock(&priv->lock);
 
     virCheckFlagsGoto(VIR_LOCK_SPACE_PROTOCOL_ACQUIRE_RESOURCE_SHARED |
-                      VIR_LOCK_SPACE_PROTOCOL_ACQUIRE_RESOURCE_AUTOCREATE, cleanup);
+                      VIR_LOCK_SPACE_PROTOCOL_ACQUIRE_RESOURCE_AUTOCREATE |
+                      VIR_LOCK_SPACE_PROTOCOL_ACQUIRE_RESOURCE_METADATA, cleanup);
 
     if (priv->restricted) {
         virReportError(VIR_ERR_OPERATION_DENIED, "%s",
@@ -82,6 +86,8 @@ virLockSpaceProtocolDispatchAcquireResource(virNetServerPtr server ATTRIBUTE_UNU
         newFlags |= VIR_LOCK_SPACE_ACQUIRE_SHARED;
     if (flags & VIR_LOCK_SPACE_PROTOCOL_ACQUIRE_RESOURCE_AUTOCREATE)
         newFlags |= VIR_LOCK_SPACE_ACQUIRE_AUTOCREATE;
+    if (flags & VIR_LOCK_SPACE_PROTOCOL_ACQUIRE_RESOURCE_METADATA)
+        start = METADATA_OFFSET;
 
     if (virLockSpaceAcquireResource(lockspace,
                                     args->name,
diff --git a/src/locking/lock_driver_lockd.c b/src/locking/lock_driver_lockd.c
index 16fce551c3..ca825e6026 100644
--- a/src/locking/lock_driver_lockd.c
+++ b/src/locking/lock_driver_lockd.c
@@ -723,7 +723,8 @@ static int virLockManagerLockDaemonRelease(virLockManagerPtr lock,
 
         args.flags &=
             ~(VIR_LOCK_SPACE_PROTOCOL_ACQUIRE_RESOURCE_SHARED |
-              VIR_LOCK_SPACE_PROTOCOL_ACQUIRE_RESOURCE_AUTOCREATE);
+              VIR_LOCK_SPACE_PROTOCOL_ACQUIRE_RESOURCE_AUTOCREATE |
+              VIR_LOCK_SPACE_PROTOCOL_ACQUIRE_RESOURCE_METADATA);
 
         if (virNetClientProgramCall(program,
                                     client,
diff --git a/src/locking/lock_driver_lockd.h b/src/locking/lock_driver_lockd.h
index 6931fe7425..bebd804365 100644
--- a/src/locking/lock_driver_lockd.h
+++ b/src/locking/lock_driver_lockd.h
@@ -25,6 +25,7 @@
 enum virLockSpaceProtocolAcquireResourceFlags {
         VIR_LOCK_SPACE_PROTOCOL_ACQUIRE_RESOURCE_SHARED = (1 << 0),
         VIR_LOCK_SPACE_PROTOCOL_ACQUIRE_RESOURCE_AUTOCREATE = (1 << 1),
+        VIR_LOCK_SPACE_PROTOCOL_ACQUIRE_RESOURCE_METADATA = (1 << 2),
 };
 
 #endif /* __VIR_LOCK_DRIVER_LOCKD_H__ */
-- 
2.16.4