1 files changed, 261 insertions, 0 deletions
diff --git a/fs/ocfs2/stackglue.h b/fs/ocfs2/stackglue.h
new file mode 100644
index 000000000000..005e4f170e0f
--- /dev/null
+++ b/fs/ocfs2/stackglue.h
@@ -0,0 +1,261 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * stackglue.h
+ *
+ * Glue to the underlying cluster stack.
+ *
+ * Copyright (C) 2007 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, version 2.
+ *
+ * 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.
+ */
+#ifndef STACKGLUE_H
+#define STACKGLUE_H
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/dlmconstants.h>
+#include "dlm/dlmapi.h"
+#include <linux/dlm.h>
+/*
+ * dlmconstants.h does not have a LOCAL flag.  We hope to remove it
+ * some day, but right now we need it.  Let's fake it.  This value is larger
+ * than any flag in dlmconstants.h.
+ */
+#define DLM_LKF_LOCAL           0x00100000
+/*
+ * This shadows DLM_LOCKSPACE_LEN in fs/dlm/dlm_internal.h.  That probably
+ * wants to be in a public header.
+ */
+#define GROUP_NAME_MAX          64
+/*
+ * ocfs2_protocol_version changes when ocfs2 does something different in
+ * its inter-node behavior.  See dlmglue.c for more information.
+ */
+struct ocfs2_protocol_version {
+        u8 pv_major;
+        u8 pv_minor;
+};
+/*
+ * The ocfs2_locking_protocol defines the handlers called on ocfs2's behalf.
+ */
+struct ocfs2_locking_protocol {
+        struct ocfs2_protocol_version lp_max_version;
+        void (*lp_lock_ast)(void *astarg);
+        void (*lp_blocking_ast)(void *astarg, int level);
+        void (*lp_unlock_ast)(void *astarg, int error);
+};
+/*
+ * The dlm_lockstatus struct includes lvb space, but the dlm_lksb struct only
+ * has a pointer to separately allocated lvb space.  This struct exists only to
+ * include in the lksb union to make space for a combined dlm_lksb and lvb.
+ */
+struct fsdlm_lksb_plus_lvb {
+        struct dlm_lksb lksb;
+        char lvb[DLM_LVB_LEN];
+};
+/*
+ * A union of all lock status structures.  We define it here so that the
+ * size of the union is known.  Lock status structures are embedded in
+ * ocfs2 inodes.
+ */
+union ocfs2_dlm_lksb {
+        struct dlm_lockstatus lksb_o2dlm;
+        struct dlm_lksb lksb_fsdlm;
+        struct fsdlm_lksb_plus_lvb padding;
+};
+/*
+ * A cluster connection.  Mostly opaque to ocfs2, the connection holds
+ * state for the underlying stack.  ocfs2 does use cc_version to determine
+ * locking compatibility.
+ */
+struct ocfs2_cluster_connection {
+        char cc_name[GROUP_NAME_MAX];
+        int cc_namelen;
+        struct ocfs2_protocol_version cc_version;
+        void (*cc_recovery_handler)(int node_num, void *recovery_data);
+        void *cc_recovery_data;
+        void *cc_lockspace;
+        void *cc_private;
+};
+/*
+ * Each cluster stack implements the stack operations structure.  Not used
+ * in the ocfs2 code, the stackglue code translates generic cluster calls
+ * into stack operations.
+ */
+struct ocfs2_stack_operations {
+        /*
+         * The fs code calls ocfs2_cluster_connect() to attach a new
+         * filesystem to the cluster stack.  The ->connect() op is passed
+         * an ocfs2_cluster_connection with the name and recovery field
+         * filled in.
+         *
+         * The stack must set up any notification mechanisms and create
+         * the filesystem lockspace in the DLM.  The lockspace should be
+         * stored on cc_lockspace.  Any other information can be stored on
+         * cc_private.
+         *
+         * ->connect() must not return until it is guaranteed that
+         *
+         *  - Node down notifications for the filesystem will be recieved
+         *    and passed to conn->cc_recovery_handler().
+         *  - Locking requests for the filesystem will be processed.
+         */
+        int (*connect)(struct ocfs2_cluster_connection *conn);
+        /*
+         * The fs code calls ocfs2_cluster_disconnect() when a filesystem
+         * no longer needs cluster services.  All DLM locks have been
+         * dropped, and recovery notification is being ignored by the
+         * fs code.  The stack must disengage from the DLM and discontinue
+         * recovery notification.
+         *
+         * Once ->disconnect() has returned, the connection structure will
+         * be freed.  Thus, a stack must not return from ->disconnect()
+         * until it will no longer reference the conn pointer.
+         *
+         * If hangup_pending is zero, ocfs2_cluster_disconnect() will also
+         * be dropping the reference on the module.
+         */
+        int (*disconnect)(struct ocfs2_cluster_connection *conn,
+                          int hangup_pending);
+        /*
+         * ocfs2_cluster_hangup() exists for compatibility with older
+         * ocfs2 tools.  Only the classic stack really needs it.  As such
+         * ->hangup() is not required of all stacks.  See the comment by
+         * ocfs2_cluster_hangup() for more details.
+         *
+         * Note that ocfs2_cluster_hangup() can only be called if
+         * hangup_pending was passed to ocfs2_cluster_disconnect().
+         */
+        void (*hangup)(const char *group, int grouplen);
+        /*
+         * ->this_node() returns the cluster's unique identifier for the
+         * local node.
+         */
+        int (*this_node)(unsigned int *node);
+        /*
+         * Call the underlying dlm lock function.  The ->dlm_lock()
+         * callback should convert the flags and mode as appropriate.
+         *
+         * ast and bast functions are not part of the call because the
+         * stack will likely want to wrap ast and bast calls before passing
+         * them to stack->sp_proto.
+         */
+        int (*dlm_lock)(struct ocfs2_cluster_connection *conn,
+                        int mode,
+                        union ocfs2_dlm_lksb *lksb,
+                        u32 flags,
+                        void *name,
+                        unsigned int namelen,
+                        void *astarg);
+        /*
+         * Call the underlying dlm unlock function.  The ->dlm_unlock()
+         * function should convert the flags as appropriate.
+         *
+         * The unlock ast is not passed, as the stack will want to wrap
+         * it before calling stack->sp_proto->lp_unlock_ast().
+         */
+        int (*dlm_unlock)(struct ocfs2_cluster_connection *conn,
+                          union ocfs2_dlm_lksb *lksb,
+                          u32 flags,
+                          void *astarg);
+        /*
+         * Return the status of the current lock status block.  The fs
+         * code should never dereference the union.  The ->lock_status()
+         * callback pulls out the stack-specific lksb, converts the status
+         * to a proper errno, and returns it.
+         */
+        int (*lock_status)(union ocfs2_dlm_lksb *lksb);
+        /*
+         * Pull the lvb pointer off of the stack-specific lksb.
+         */
+        void *(*lock_lvb)(union ocfs2_dlm_lksb *lksb);
+        /*
+         * This is an optoinal debugging hook.  If provided, the
+         * stack can dump debugging information about this lock.
+         */
+        void (*dump_lksb)(union ocfs2_dlm_lksb *lksb);
+};
+/*
+ * Each stack plugin must describe itself by registering a
+ * ocfs2_stack_plugin structure.  This is only seen by stackglue and the
+ * stack driver.
+ */
+struct ocfs2_stack_plugin {
+        char *sp_name;
+        struct ocfs2_stack_operations *sp_ops;
+        struct module *sp_owner;
+        /* These are managed by the stackglue code. */
+        struct list_head sp_list;
+        unsigned int sp_count;
+        struct ocfs2_locking_protocol *sp_proto;
+};
+/* Used by the filesystem */
+int ocfs2_cluster_connect(const char *stack_name,
+                          const char *group,
+                          int grouplen,
+                          void (*recovery_handler)(int node_num,
+                                                   void *recovery_data),
+                          void *recovery_data,
+                          struct ocfs2_cluster_connection **conn);
+int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn,
+                             int hangup_pending);
+void ocfs2_cluster_hangup(const char *group, int grouplen);
+int ocfs2_cluster_this_node(unsigned int *node);
+struct ocfs2_lock_res;
+int ocfs2_dlm_lock(struct ocfs2_cluster_connection *conn,
+                   int mode,
+                   union ocfs2_dlm_lksb *lksb,
+                   u32 flags,
+                   void *name,
+                   unsigned int namelen,
+                   struct ocfs2_lock_res *astarg);
+int ocfs2_dlm_unlock(struct ocfs2_cluster_connection *conn,
+                     union ocfs2_dlm_lksb *lksb,
+                     u32 flags,
+                     struct ocfs2_lock_res *astarg);
+int ocfs2_dlm_lock_status(union ocfs2_dlm_lksb *lksb);
+void *ocfs2_dlm_lvb(union ocfs2_dlm_lksb *lksb);
+void ocfs2_dlm_dump_lksb(union ocfs2_dlm_lksb *lksb);
+void ocfs2_stack_glue_set_locking_protocol(struct ocfs2_locking_protocol *proto);
+/* Used by stack plugins */
+int ocfs2_stack_glue_register(struct ocfs2_stack_plugin *plugin);
+void ocfs2_stack_glue_unregister(struct ocfs2_stack_plugin *plugin);
+#endif  /* STACKGLUE_H */

diff --git a/fs/ocfs2/stackglue.h b/fs/ocfs2/stackglue.h new file mode 100644 index 000000000000..005e4f170e0f --- /dev/null +++ b/fs/ocfs2/stackglue.h
@@ -0,0 +1,261 @@
	1	/* -- mode: c; c-basic-offset: 8; --
	2	* vim: noexpandtab sw=8 ts=8 sts=0:
	3	*
	4	* stackglue.h
	5	*
	6	* Glue to the underlying cluster stack.
	7	*
	8	* Copyright (C) 2007 Oracle. All rights reserved.
	9	*
	10	* This program is free software; you can redistribute it and/or
	11	* modify it under the terms of the GNU General Public
	12	* License as published by the Free Software Foundation, version 2.
	13	*
	14	* This program is distributed in the hope that it will be useful,
	15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	17	* General Public License for more details.
	18	*/
	19
	20
	21	#ifndef STACKGLUE_H
	22	#define STACKGLUE_H
	23
	24	#include <linux/types.h>
	25	#include <linux/list.h>
	26	#include <linux/dlmconstants.h>
	27
	28	#include "dlm/dlmapi.h"
	29	#include <linux/dlm.h>
	30
	31	/*
	32	* dlmconstants.h does not have a LOCAL flag. We hope to remove it
	33	* some day, but right now we need it. Let's fake it. This value is larger
	34	* than any flag in dlmconstants.h.
	35	*/
	36	#define DLM_LKF_LOCAL 0x00100000
	37
	38	/*
	39	* This shadows DLM_LOCKSPACE_LEN in fs/dlm/dlm_internal.h. That probably
	40	* wants to be in a public header.
	41	*/
	42	#define GROUP_NAME_MAX 64
	43
	44
	45	/*
	46	* ocfs2_protocol_version changes when ocfs2 does something different in
	47	* its inter-node behavior. See dlmglue.c for more information.
	48	*/
	49	struct ocfs2_protocol_version {
	50	u8 pv_major;
	51	u8 pv_minor;
	52	};
	53
	54	/*
	55	* The ocfs2_locking_protocol defines the handlers called on ocfs2's behalf.
	56	*/
	57	struct ocfs2_locking_protocol {
	58	struct ocfs2_protocol_version lp_max_version;
	59	void (lp_lock_ast)(void astarg);
	60	void (lp_blocking_ast)(void astarg, int level);
	61	void (lp_unlock_ast)(void astarg, int error);
	62	};
	63
	64
	65	/*
	66	* The dlm_lockstatus struct includes lvb space, but the dlm_lksb struct only
	67	* has a pointer to separately allocated lvb space. This struct exists only to
	68	* include in the lksb union to make space for a combined dlm_lksb and lvb.
	69	*/
	70	struct fsdlm_lksb_plus_lvb {
	71	struct dlm_lksb lksb;
	72	char lvb[DLM_LVB_LEN];
	73	};
	74
	75	/*
	76	* A union of all lock status structures. We define it here so that the
	77	* size of the union is known. Lock status structures are embedded in
	78	* ocfs2 inodes.
	79	*/
	80	union ocfs2_dlm_lksb {
	81	struct dlm_lockstatus lksb_o2dlm;
	82	struct dlm_lksb lksb_fsdlm;
	83	struct fsdlm_lksb_plus_lvb padding;
	84	};
	85
	86	/*
	87	* A cluster connection. Mostly opaque to ocfs2, the connection holds
	88	* state for the underlying stack. ocfs2 does use cc_version to determine
	89	* locking compatibility.
	90	*/
	91	struct ocfs2_cluster_connection {
	92	char cc_name[GROUP_NAME_MAX];
	93	int cc_namelen;
	94	struct ocfs2_protocol_version cc_version;
	95	void (cc_recovery_handler)(int node_num, void recovery_data);
	96	void *cc_recovery_data;
	97	void *cc_lockspace;
	98	void *cc_private;
	99	};
	100
	101	/*
	102	* Each cluster stack implements the stack operations structure. Not used
	103	* in the ocfs2 code, the stackglue code translates generic cluster calls
	104	* into stack operations.
	105	*/
	106	struct ocfs2_stack_operations {
	107	/*
	108	* The fs code calls ocfs2_cluster_connect() to attach a new
	109	* filesystem to the cluster stack. The ->connect() op is passed
	110	* an ocfs2_cluster_connection with the name and recovery field
	111	* filled in.
	112	*
	113	* The stack must set up any notification mechanisms and create
	114	* the filesystem lockspace in the DLM. The lockspace should be
	115	* stored on cc_lockspace. Any other information can be stored on
	116	* cc_private.
	117	*
	118	* ->connect() must not return until it is guaranteed that
	119	*
	120	* - Node down notifications for the filesystem will be recieved
	121	* and passed to conn->cc_recovery_handler().
	122	* - Locking requests for the filesystem will be processed.
	123	*/
	124	int (connect)(struct ocfs2_cluster_connection conn);
	125
	126	/*
	127	* The fs code calls ocfs2_cluster_disconnect() when a filesystem
	128	* no longer needs cluster services. All DLM locks have been
	129	* dropped, and recovery notification is being ignored by the
	130	* fs code. The stack must disengage from the DLM and discontinue
	131	* recovery notification.
	132	*
	133	* Once ->disconnect() has returned, the connection structure will
	134	* be freed. Thus, a stack must not return from ->disconnect()
	135	* until it will no longer reference the conn pointer.
	136	*
	137	* If hangup_pending is zero, ocfs2_cluster_disconnect() will also
	138	* be dropping the reference on the module.
	139	*/
	140	int (disconnect)(struct ocfs2_cluster_connection conn,
	141	int hangup_pending);
	142
	143	/*
	144	* ocfs2_cluster_hangup() exists for compatibility with older
	145	* ocfs2 tools. Only the classic stack really needs it. As such
	146	* ->hangup() is not required of all stacks. See the comment by
	147	* ocfs2_cluster_hangup() for more details.
	148	*
	149	* Note that ocfs2_cluster_hangup() can only be called if
	150	* hangup_pending was passed to ocfs2_cluster_disconnect().
	151	*/
	152	void (hangup)(const char group, int grouplen);
	153
	154	/*
	155	* ->this_node() returns the cluster's unique identifier for the
	156	* local node.
	157	*/
	158	int (this_node)(unsigned int node);
	159
	160	/*
	161	* Call the underlying dlm lock function. The ->dlm_lock()
	162	* callback should convert the flags and mode as appropriate.
	163	*
	164	* ast and bast functions are not part of the call because the
	165	* stack will likely want to wrap ast and bast calls before passing
	166	* them to stack->sp_proto.
	167	*/
	168	int (dlm_lock)(struct ocfs2_cluster_connection conn,
	169	int mode,
	170	union ocfs2_dlm_lksb *lksb,
	171	u32 flags,
	172	void *name,
	173	unsigned int namelen,
	174	void *astarg);
	175
	176	/*
	177	* Call the underlying dlm unlock function. The ->dlm_unlock()
	178	* function should convert the flags as appropriate.
	179	*
	180	* The unlock ast is not passed, as the stack will want to wrap
	181	* it before calling stack->sp_proto->lp_unlock_ast().
	182	*/
	183	int (dlm_unlock)(struct ocfs2_cluster_connection conn,
	184	union ocfs2_dlm_lksb *lksb,
	185	u32 flags,
	186	void *astarg);
	187
	188	/*
	189	* Return the status of the current lock status block. The fs
	190	* code should never dereference the union. The ->lock_status()
	191	* callback pulls out the stack-specific lksb, converts the status
	192	* to a proper errno, and returns it.
	193	*/
	194	int (lock_status)(union ocfs2_dlm_lksb lksb);
	195
	196	/*
	197	* Pull the lvb pointer off of the stack-specific lksb.
	198	*/
	199	void (lock_lvb)(union ocfs2_dlm_lksb *lksb);
	200
	201	/*
	202	* This is an optoinal debugging hook. If provided, the
	203	* stack can dump debugging information about this lock.
	204	*/
	205	void (dump_lksb)(union ocfs2_dlm_lksb lksb);
	206	};
	207
	208	/*
	209	* Each stack plugin must describe itself by registering a
	210	* ocfs2_stack_plugin structure. This is only seen by stackglue and the
	211	* stack driver.
	212	*/
	213	struct ocfs2_stack_plugin {
	214	char *sp_name;
	215	struct ocfs2_stack_operations *sp_ops;
	216	struct module *sp_owner;
	217
	218	/* These are managed by the stackglue code. */
	219	struct list_head sp_list;
	220	unsigned int sp_count;
	221	struct ocfs2_locking_protocol *sp_proto;
	222	};
	223
	224
	225	/* Used by the filesystem */
	226	int ocfs2_cluster_connect(const char *stack_name,
	227	const char *group,
	228	int grouplen,
	229	void (*recovery_handler)(int node_num,
	230	void *recovery_data),
	231	void *recovery_data,
	232	struct ocfs2_cluster_connection **conn);
	233	int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn,
	234	int hangup_pending);
	235	void ocfs2_cluster_hangup(const char *group, int grouplen);
	236	int ocfs2_cluster_this_node(unsigned int *node);
	237
	238	struct ocfs2_lock_res;
	239	int ocfs2_dlm_lock(struct ocfs2_cluster_connection *conn,
	240	int mode,
	241	union ocfs2_dlm_lksb *lksb,
	242	u32 flags,
	243	void *name,
	244	unsigned int namelen,
	245	struct ocfs2_lock_res *astarg);
	246	int ocfs2_dlm_unlock(struct ocfs2_cluster_connection *conn,
	247	union ocfs2_dlm_lksb *lksb,
	248	u32 flags,
	249	struct ocfs2_lock_res *astarg);
	250
	251	int ocfs2_dlm_lock_status(union ocfs2_dlm_lksb *lksb);
	252	void ocfs2_dlm_lvb(union ocfs2_dlm_lksb lksb);
	253	void ocfs2_dlm_dump_lksb(union ocfs2_dlm_lksb *lksb);
	254
	255	void ocfs2_stack_glue_set_locking_protocol(struct ocfs2_locking_protocol *proto);
	256
	257
	258	/* Used by stack plugins */
	259	int ocfs2_stack_glue_register(struct ocfs2_stack_plugin *plugin);
	260	void ocfs2_stack_glue_unregister(struct ocfs2_stack_plugin *plugin);
	261	#endif /* STACKGLUE_H */