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Joel Becker24ef1812008-01-29 17:37:32 -08001/* -*- 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
Joel Beckerbd3e7612008-02-01 12:14:57 -080024#include <linux/types.h>
25#include <linux/list.h>
26#include <linux/dlmconstants.h>
27
Joel Beckere3dad422008-02-01 15:02:36 -080028#include "dlm/dlmapi.h"
David Teiglandcf4d8d72008-02-20 14:29:27 -080029#include <linux/dlm.h>
Joel Beckere3dad422008-02-01 15:02:36 -080030
Joel Beckerbd3e7612008-02-01 12:14:57 -080031/*
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
Joel Becker4670c462008-02-01 14:39:35 -080038/*
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
Joel Beckere3dad422008-02-01 15:02:36 -080045/*
46 * ocfs2_protocol_version changes when ocfs2 does something different in
47 * its inter-node behavior. See dlmglue.c for more information.
48 */
Joel Becker4670c462008-02-01 14:39:35 -080049struct ocfs2_protocol_version {
50 u8 pv_major;
51 u8 pv_minor;
52};
53
Joel Beckere3dad422008-02-01 15:02:36 -080054/*
55 * The ocfs2_locking_protocol defines the handlers called on ocfs2's behalf.
56 */
Joel Becker24ef1812008-01-29 17:37:32 -080057struct ocfs2_locking_protocol {
Joel Becker4670c462008-02-01 14:39:35 -080058 struct ocfs2_protocol_version lp_max_version;
Joel Becker24ef1812008-01-29 17:37:32 -080059 void (*lp_lock_ast)(void *astarg);
60 void (*lp_blocking_ast)(void *astarg, int level);
Joel Becker7431cd72008-02-01 12:15:37 -080061 void (*lp_unlock_ast)(void *astarg, int error);
Joel Becker24ef1812008-01-29 17:37:32 -080062};
63
David Teiglandcf4d8d72008-02-20 14:29:27 -080064
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 */
70struct fsdlm_lksb_plus_lvb {
71 struct dlm_lksb lksb;
72 char lvb[DLM_LVB_LEN];
73};
74
Joel Beckere3dad422008-02-01 15:02:36 -080075/*
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 */
Joel Becker8f2c9c12008-02-01 12:16:57 -080080union ocfs2_dlm_lksb {
81 struct dlm_lockstatus lksb_o2dlm;
David Teiglandcf4d8d72008-02-20 14:29:27 -080082 struct dlm_lksb lksb_fsdlm;
83 struct fsdlm_lksb_plus_lvb padding;
Joel Becker8f2c9c12008-02-01 12:16:57 -080084};
85
Joel Beckere3dad422008-02-01 15:02:36 -080086/*
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 */
Joel Becker4670c462008-02-01 14:39:35 -080091struct 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
Joel Beckere3dad422008-02-01 15:02:36 -0800101/*
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 */
106struct 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.
Joel Becker286eaa92008-02-01 15:03:57 -0800136 *
Joel Becker2c394502008-05-30 15:58:26 -0700137 * Once this call returns, the stack glue will be dropping this
138 * connection's reference on the module.
Joel Beckere3dad422008-02-01 15:02:36 -0800139 */
Joel Becker2c394502008-05-30 15:58:26 -0700140 int (*disconnect)(struct ocfs2_cluster_connection *conn);
Joel Beckere3dad422008-02-01 15:02:36 -0800141
142 /*
143 * ->this_node() returns the cluster's unique identifier for the
144 * local node.
145 */
146 int (*this_node)(unsigned int *node);
147
148 /*
149 * Call the underlying dlm lock function. The ->dlm_lock()
150 * callback should convert the flags and mode as appropriate.
151 *
152 * ast and bast functions are not part of the call because the
153 * stack will likely want to wrap ast and bast calls before passing
154 * them to stack->sp_proto.
155 */
156 int (*dlm_lock)(struct ocfs2_cluster_connection *conn,
157 int mode,
158 union ocfs2_dlm_lksb *lksb,
159 u32 flags,
160 void *name,
161 unsigned int namelen,
162 void *astarg);
163
164 /*
165 * Call the underlying dlm unlock function. The ->dlm_unlock()
166 * function should convert the flags as appropriate.
167 *
168 * The unlock ast is not passed, as the stack will want to wrap
169 * it before calling stack->sp_proto->lp_unlock_ast().
170 */
171 int (*dlm_unlock)(struct ocfs2_cluster_connection *conn,
172 union ocfs2_dlm_lksb *lksb,
173 u32 flags,
174 void *astarg);
175
176 /*
177 * Return the status of the current lock status block. The fs
178 * code should never dereference the union. The ->lock_status()
179 * callback pulls out the stack-specific lksb, converts the status
180 * to a proper errno, and returns it.
181 */
182 int (*lock_status)(union ocfs2_dlm_lksb *lksb);
183
184 /*
185 * Pull the lvb pointer off of the stack-specific lksb.
186 */
187 void *(*lock_lvb)(union ocfs2_dlm_lksb *lksb);
188
189 /*
190 * This is an optoinal debugging hook. If provided, the
191 * stack can dump debugging information about this lock.
192 */
193 void (*dump_lksb)(union ocfs2_dlm_lksb *lksb);
194};
195
Joel Becker286eaa92008-02-01 15:03:57 -0800196/*
197 * Each stack plugin must describe itself by registering a
198 * ocfs2_stack_plugin structure. This is only seen by stackglue and the
199 * stack driver.
200 */
201struct ocfs2_stack_plugin {
202 char *sp_name;
203 struct ocfs2_stack_operations *sp_ops;
204 struct module *sp_owner;
205
206 /* These are managed by the stackglue code. */
207 struct list_head sp_list;
208 unsigned int sp_count;
209 struct ocfs2_locking_protocol *sp_proto;
210};
211
212
213/* Used by the filesystem */
Joel Becker9c6c8772008-02-01 15:17:30 -0800214int ocfs2_cluster_connect(const char *stack_name,
215 const char *group,
Joel Becker4670c462008-02-01 14:39:35 -0800216 int grouplen,
217 void (*recovery_handler)(int node_num,
218 void *recovery_data),
219 void *recovery_data,
220 struct ocfs2_cluster_connection **conn);
Joel Becker286eaa92008-02-01 15:03:57 -0800221int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn,
222 int hangup_pending);
Joel Becker6953b4c2008-01-29 16:59:56 -0800223void ocfs2_cluster_hangup(const char *group, int grouplen);
Joel Becker19fdb622008-01-30 15:38:24 -0800224int ocfs2_cluster_this_node(unsigned int *node);
Joel Becker4670c462008-02-01 14:39:35 -0800225
David Teiglandcf4d8d72008-02-20 14:29:27 -0800226struct ocfs2_lock_res;
Joel Becker4670c462008-02-01 14:39:35 -0800227int ocfs2_dlm_lock(struct ocfs2_cluster_connection *conn,
Joel Becker24ef1812008-01-29 17:37:32 -0800228 int mode,
Joel Becker8f2c9c12008-02-01 12:16:57 -0800229 union ocfs2_dlm_lksb *lksb,
Joel Becker24ef1812008-01-29 17:37:32 -0800230 u32 flags,
231 void *name,
232 unsigned int namelen,
David Teiglandcf4d8d72008-02-20 14:29:27 -0800233 struct ocfs2_lock_res *astarg);
Joel Becker4670c462008-02-01 14:39:35 -0800234int ocfs2_dlm_unlock(struct ocfs2_cluster_connection *conn,
Joel Becker8f2c9c12008-02-01 12:16:57 -0800235 union ocfs2_dlm_lksb *lksb,
Joel Becker24ef1812008-01-29 17:37:32 -0800236 u32 flags,
David Teiglandcf4d8d72008-02-20 14:29:27 -0800237 struct ocfs2_lock_res *astarg);
Joel Becker24ef1812008-01-29 17:37:32 -0800238
Joel Becker8f2c9c12008-02-01 12:16:57 -0800239int ocfs2_dlm_lock_status(union ocfs2_dlm_lksb *lksb);
240void *ocfs2_dlm_lvb(union ocfs2_dlm_lksb *lksb);
Joel Beckercf0acdc2008-01-29 16:59:55 -0800241void ocfs2_dlm_dump_lksb(union ocfs2_dlm_lksb *lksb);
Joel Becker8f2c9c12008-02-01 12:16:57 -0800242
Joel Becker63e0c482008-01-30 16:58:36 -0800243void ocfs2_stack_glue_set_locking_protocol(struct ocfs2_locking_protocol *proto);
Joel Becker24ef1812008-01-29 17:37:32 -0800244
Joel Becker286eaa92008-02-01 15:03:57 -0800245
246/* Used by stack plugins */
247int ocfs2_stack_glue_register(struct ocfs2_stack_plugin *plugin);
248void ocfs2_stack_glue_unregister(struct ocfs2_stack_plugin *plugin);
Joel Becker3878f112008-05-30 15:30:49 -0700249
Joel Becker24ef1812008-01-29 17:37:32 -0800250#endif /* STACKGLUE_H */