glusterd: Volume locks and transaction specific opinfos

With this patch we are replacing the existing cluster-wide
lock taken on glusterds across the cluster, with volume locks
which are also taken on glusterds across the cluster, but are
volume specific. So with the volume locks we are able to perform
more than one gluster operation at the same time, as long as the
operations are being performed on different volumes.

We maintain a global list of volume-locks (using a dict for a list)
where the key is the volume name, and which saves the uuid of the
originator glusterd. These locks are held and released per volume
transaction.

In order to acheive multiple gluster operations occuring at the
same time, we also separate opinfos in the op-state-machine, as a
part of this patch. To do so, we generate a unique transaction-id
(uuid) per gluster transaction. An opinfo is then associated with
this transaction id, which is used throughout the transaction. We
maintain a run-time global list(using a dict) of transaction-ids,
and their respective opinfos to achieve this.

Upstream Feature Page: http://www.gluster.org/community/documentation/index.php/Features/glusterd-volume-locks

Change-Id: Iaad505a854bac8de8f83beec0357eb6cde3f7ea8
BUG: 1011470
Signed-off-by: Avra Sengupta <asengupt@redhat.com>
Reviewed-on: http://review.gluster.org/5994
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd.h b/xlators/mgmt/glusterd/src/glusterd.h
index 9b6e2fb3343..e8035c7c619 100644
--- a/xlators/mgmt/glusterd/src/glusterd.h
+++ b/xlators/mgmt/glusterd/src/glusterd.h
@@ -525,6 +525,14 @@ int
 glusterd_op_unlock_send_resp (rpcsvc_request_t *req, int32_t status);
 
 int
+glusterd_op_volume_lock_send_resp (rpcsvc_request_t *req,
+                                   uuid_t *txn_id, int32_t status);
+
+int
+glusterd_op_volume_unlock_send_resp (rpcsvc_request_t *req,
+                                     uuid_t *txn_id, int32_t status);
+
+int
 glusterd_op_stage_send_resp (rpcsvc_request_t *req,
                              int32_t op, int32_t status,
                              char *op_errstr, dict_t *rsp_dict);
@@ -797,4 +805,14 @@ int32_t glusterd_op_begin_synctask (rpcsvc_request_t *req, glusterd_op_t op,
                                     void *dict);
 int32_t
 glusterd_defrag_event_notify_handle (dict_t *dict);
+
+int32_t
+glusterd_txn_opinfo_dict_init ();
+
+void
+glusterd_txn_opinfo_dict_fini ();
+
+void
+glusterd_txn_opinfo_init ();
+
 #endif