[PATCH] OCFS2: The Second Oracle Cluster Filesystem

dlmfs: A minimal dlm userspace interface implemented via a virtual
file system.
Most of the OCFS2 tools make use of this to take cluster locks when
doing operations on the file system.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com>

1 files changed, 111 insertions, 0 deletions

diff --git a/fs/ocfs2/dlm/userdlm.h b/fs/ocfs2/dlm/userdlm.h
new file mode 100644
index 000000000000..04178bc40b76
--- /dev/null
+++ b/fs/ocfs2/dlm/userdlm.h
@@ -0,0 +1,111 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * userdlm.h
+ *
+ * Userspace dlm defines
+ *
+ * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+
+#ifndef USERDLM_H
+#define USERDLM_H
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+
+/* user_lock_res->l_flags flags. */
+#define USER_LOCK_ATTACHED      (0x00000001) /* have we initialized
+                                               * the lvb */
+#define USER_LOCK_BUSY          (0x00000002) /* we are currently in
+                                               * dlm_lock */
+#define USER_LOCK_BLOCKED       (0x00000004) /* blocked waiting to
+                                              * downconvert*/
+#define USER_LOCK_IN_TEARDOWN   (0x00000008) /* we're currently
+                                              * destroying this
+                                              * lock. */
+#define USER_LOCK_QUEUED        (0x00000010) /* lock is on the
+                                              * workqueue */
+#define USER_LOCK_IN_CANCEL     (0x00000020)
+
+struct user_lock_res {
+        spinlock_t               l_lock;
+
+        int                      l_flags;
+
+#define USER_DLM_LOCK_ID_MAX_LEN  32
+        char                     l_name[USER_DLM_LOCK_ID_MAX_LEN];
+        int                      l_level;
+        unsigned int             l_ro_holders;
+        unsigned int             l_ex_holders;
+        struct dlm_lockstatus    l_lksb;
+
+        int                      l_requested;
+        int                      l_blocking;
+
+        wait_queue_head_t        l_event;
+
+        struct work_struct       l_work;
+};
+
+extern struct workqueue_struct *user_dlm_worker;
+
+void user_dlm_lock_res_init(struct user_lock_res *lockres,
+                            struct dentry *dentry);
+int user_dlm_destroy_lock(struct user_lock_res *lockres);
+int user_dlm_cluster_lock(struct user_lock_res *lockres,
+                          int level,
+                          int lkm_flags);
+void user_dlm_cluster_unlock(struct user_lock_res *lockres,
+                             int level);
+void user_dlm_write_lvb(struct inode *inode,
+                        const char *val,
+                        unsigned int len);
+void user_dlm_read_lvb(struct inode *inode,
+                       char *val,
+                       unsigned int len);
+struct dlm_ctxt *user_dlm_register_context(struct qstr *name);
+void user_dlm_unregister_context(struct dlm_ctxt *dlm);
+
+struct dlmfs_inode_private {
+        struct dlm_ctxt             *ip_dlm;
+
+        struct user_lock_res ip_lockres; /* unused for directories. */
+        struct inode         *ip_parent;
+
+        struct inode         ip_vfs_inode;
+};
+
+static inline struct dlmfs_inode_private *
+DLMFS_I(struct inode *inode)
+{
+        return container_of(inode,
+                            struct dlmfs_inode_private,
+                            ip_vfs_inode);
+}
+
+struct dlmfs_filp_private {
+        int                  fp_lock_level;
+};
+
+#define DLMFS_MAGIC     0x76a9f425
+
+#endif /* USERDLM_H */