[Ocfs2-devel] [PATCH 1/3] ocfs2:freeze-thaw: add freeze cluster lock

[Wengang Wang]

add cluster lock for freeze/thaw.
change dlm version from 1.0 to 1.1

Authored-by: Tiger Yang <tiger.yang at oracle.com>
Authored-by: Wengang Wang <wen.gang.wang at oracle.com>
Signed-off-by: Wengang Wang <wen.gang.wang at oracle.com>
---
 fs/ocfs2/dlm/dlmdomain.c |    6 +++++-
 fs/ocfs2/dlmglue.c       |   28 ++++++++++++++++++++++++++++
 fs/ocfs2/dlmglue.h       |    2 ++
 fs/ocfs2/ocfs2.h         |    1 +
 fs/ocfs2/ocfs2_lockid.h  |    5 +++++
 5 files changed, 41 insertions(+), 1 deletions(-)

diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c
index 0334000..6e8bcb6 100644
--- a/fs/ocfs2/dlm/dlmdomain.c
+++ b/fs/ocfs2/dlm/dlmdomain.c
@@ -128,10 +128,14 @@ static DECLARE_WAIT_QUEUE_HEAD(dlm_domain_events);
  * will have a negotiated version with the same major number and a minor
  * number equal or smaller.  The dlm_ctxt->dlm_locking_proto field should
  * be used to determine what a running domain is actually using.
+ *
+ * dlm protocal history:
+ * 1.0:	base
+ * 1.1:	freeze lock support added
  */
 static const struct dlm_protocol_version dlm_protocol = {
 	.pv_major = 1,
-	.pv_minor = 0,
+	.pv_minor = 1,
 };
 
 #define DLM_DOMAIN_BACKOFF_MS 200
diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index c5e4a49..0caa69e 100644
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -2894,6 +2894,34 @@ static const struct file_operations ocfs2_dlm_debug_fops = {
 	.llseek =	seq_lseek,
 };
 
+int ocfs2_freeze_lock(struct ocfs2_super *osb, int ex)
+{
+	int ret;
+	int level = ex ? LKM_EXMODE : LKM_PRMODE;
+	struct ocfs2_lock_res *lockres = &osb->osb_freeze_lockres;
+
+	if (ocfs2_is_hard_readonly(osb))
+		return -EROFS;
+
+	if (ocfs2_mount_local(osb))
+		return 0;
+
+	ret = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
+	if (ret < 0)
+		mlog_errno(ret);
+
+	return ret;
+}
+
+void ocfs2_freeze_unlock(struct ocfs2_super *osb, int ex)
+{
+	int level = ex ? LKM_EXMODE : LKM_PRMODE;
+	struct ocfs2_lock_res *lockres = &osb->osb_freeze_lockres;
+
+	if (!ocfs2_mount_local(osb))
+		ocfs2_cluster_unlock(osb, lockres, level);
+}
+
 static int ocfs2_dlm_init_debug(struct ocfs2_super *osb)
 {
 	int ret = 0;
diff --git a/fs/ocfs2/dlmglue.h b/fs/ocfs2/dlmglue.h
index d1ce48e..8687b81 100644
--- a/fs/ocfs2/dlmglue.h
+++ b/fs/ocfs2/dlmglue.h
@@ -155,6 +155,8 @@ struct ocfs2_refcount_tree;
 int ocfs2_refcount_lock(struct ocfs2_refcount_tree *ref_tree, int ex);
 void ocfs2_refcount_unlock(struct ocfs2_refcount_tree *ref_tree, int ex);
 
+int ocfs2_freeze_lock(struct ocfs2_super *osb, int ex);
+void ocfs2_freeze_unlock(struct ocfs2_super *osb, int ex);
 
 void ocfs2_mark_lockres_freeing(struct ocfs2_lock_res *lockres);
 void ocfs2_simple_drop_lockres(struct ocfs2_super *osb,
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index d963d86..bf66978 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -355,6 +355,7 @@ struct ocfs2_super
 	struct ocfs2_lock_res osb_super_lockres;
 	struct ocfs2_lock_res osb_rename_lockres;
 	struct ocfs2_lock_res osb_nfs_sync_lockres;
+	struct ocfs2_lock_res osb_freeze_lockres;
 	struct ocfs2_dlm_debug *osb_dlm_debug;
 
 	struct dentry *osb_debug_root;
diff --git a/fs/ocfs2/ocfs2_lockid.h b/fs/ocfs2/ocfs2_lockid.h
index d277aab..3c29924 100644
--- a/fs/ocfs2/ocfs2_lockid.h
+++ b/fs/ocfs2/ocfs2_lockid.h
@@ -50,6 +50,7 @@ enum ocfs2_lock_type {
 	OCFS2_LOCK_TYPE_NFS_SYNC,
 	OCFS2_LOCK_TYPE_ORPHAN_SCAN,
 	OCFS2_LOCK_TYPE_REFCOUNT,
+	OCFS2_LOCK_TYPE_FREEZE,
 	OCFS2_NUM_LOCK_TYPES
 };
 
@@ -93,6 +94,9 @@ static inline char ocfs2_lock_type_char(enum ocfs2_lock_type type)
 		case OCFS2_LOCK_TYPE_REFCOUNT:
 			c = 'T';
 			break;
+		case OCFS2_LOCK_TYPE_FREEZE:
+			c = 'Z';
+			break;
 		default:
 			c = '\0';
 	}
@@ -115,6 +119,7 @@ static char *ocfs2_lock_type_strings[] = {
 	[OCFS2_LOCK_TYPE_NFS_SYNC] = "NFSSync",
 	[OCFS2_LOCK_TYPE_ORPHAN_SCAN] = "OrphanScan",
 	[OCFS2_LOCK_TYPE_REFCOUNT] = "Refcount",
+	[OCFS2_LOCK_TYPE_FREEZE] = "Freeze",
 };
 
 static inline const char *ocfs2_lock_type_string(enum ocfs2_lock_type type)
-- 
1.6.5.2