[DLM] The core of the DLM for GFS2/CLVM

This is the core of the distributed lock manager which is required
to use GFS2 as a cluster filesystem. It is also used by CLVM and
can be used as a standalone lock manager independantly of either
of these two projects.

It implements VAX-style locking modes.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steve Whitehouse <swhiteho@redhat.com>

1 files changed, 84 insertions, 0 deletions

diff --git a/include/linux/dlm_device.h b/include/linux/dlm_device.h
new file mode 100644
index 000000000000..5e17d295544b
--- /dev/null
+++ b/include/linux/dlm_device.h
@@ -0,0 +1,84 @@
+/******************************************************************************
+*******************************************************************************
+**
+**  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
+**  Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
+**
+**  This copyrighted material is made available to anyone wishing to use,
+**  modify, copy, or redistribute it subject to the terms and conditions
+**  of the GNU General Public License v.2.
+**
+*******************************************************************************
+******************************************************************************/
+
+/* This is the device interface for dlm, most users will use a library
+ * interface.
+ */
+
+#define DLM_USER_LVB_LEN        32
+
+/* Version of the device interface */
+#define DLM_DEVICE_VERSION_MAJOR 3
+#define DLM_DEVICE_VERSION_MINOR 0
+#define DLM_DEVICE_VERSION_PATCH 0
+
+/* struct passed to the lock write */
+struct dlm_lock_params {
+        __u8 mode;
+        __u16 flags;
+        __u32 lkid;
+        __u32 parent;
+        struct dlm_range range;
+        __u8 namelen;
+        void __user *castparam;
+        void __user *castaddr;
+        void __user *bastparam;
+        void __user *bastaddr;
+        struct dlm_lksb __user *lksb;
+        char lvb[DLM_USER_LVB_LEN];
+        char name[1];
+};
+
+struct dlm_lspace_params {
+        __u32 flags;
+        __u32 minor;
+        char name[1];
+};
+
+struct dlm_write_request {
+        __u32 version[3];
+        __u8 cmd;
+
+        union  {
+                struct dlm_lock_params   lock;
+                struct dlm_lspace_params lspace;
+        } i;
+};
+
+/* struct read from the "device" fd,
+   consists mainly of userspace pointers for the library to use */
+struct dlm_lock_result {
+        __u32 length;
+        void __user * user_astaddr;
+        void __user * user_astparam;
+        struct dlm_lksb __user * user_lksb;
+        struct dlm_lksb lksb;
+        __u8 bast_mode;
+        /* Offsets may be zero if no data is present */
+        __u32 lvb_offset;
+};
+
+/* Commands passed to the device */
+#define DLM_USER_LOCK         1
+#define DLM_USER_UNLOCK       2
+#define DLM_USER_QUERY        3
+#define DLM_USER_CREATE_LOCKSPACE  4
+#define DLM_USER_REMOVE_LOCKSPACE  5
+
+/* Arbitrary length restriction */
+#define MAX_LS_NAME_LEN 64
+
+/* Lockspace flags */
+#define DLM_USER_LSFLG_AUTOFREE   1
+#define DLM_USER_LSFLG_FORCEFREE  2
+