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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
Mark Fasheh53da4932008-07-21 14:29:16 -070031/* Needed for plock-related prototypes */
32struct file;
33struct file_lock;
34
Joel Beckerbd3e7612008-02-01 12:14:57 -080035/*
36 * dlmconstants.h does not have a LOCAL flag. We hope to remove it
37 * some day, but right now we need it. Let's fake it. This value is larger
38 * than any flag in dlmconstants.h.
39 */
40#define DLM_LKF_LOCAL 0x00100000
41
Joel Becker4670c462008-02-01 14:39:35 -080042/*
43 * This shadows DLM_LOCKSPACE_LEN in fs/dlm/dlm_internal.h. That probably
44 * wants to be in a public header.
45 */
46#define GROUP_NAME_MAX 64
47
48
Joel Beckere3dad422008-02-01 15:02:36 -080049/*
50 * ocfs2_protocol_version changes when ocfs2 does something different in
51 * its inter-node behavior. See dlmglue.c for more information.
52 */
Joel Becker4670c462008-02-01 14:39:35 -080053struct ocfs2_protocol_version {
54 u8 pv_major;
55 u8 pv_minor;
56};
57
Joel Beckere3dad422008-02-01 15:02:36 -080058/*
David Teiglandcf4d8d72008-02-20 14:29:27 -080059 * The dlm_lockstatus struct includes lvb space, but the dlm_lksb struct only
60 * has a pointer to separately allocated lvb space. This struct exists only to
61 * include in the lksb union to make space for a combined dlm_lksb and lvb.
62 */
63struct fsdlm_lksb_plus_lvb {
64 struct dlm_lksb lksb;
65 char lvb[DLM_LVB_LEN];
66};
67
Joel Beckere3dad422008-02-01 15:02:36 -080068/*
69 * A union of all lock status structures. We define it here so that the
70 * size of the union is known. Lock status structures are embedded in
71 * ocfs2 inodes.
72 */
Joel Beckerc0e41332010-01-29 14:46:44 -080073struct ocfs2_cluster_connection;
74struct ocfs2_dlm_lksb {
75 union {
76 struct dlm_lockstatus lksb_o2dlm;
77 struct dlm_lksb lksb_fsdlm;
78 struct fsdlm_lksb_plus_lvb padding;
79 };
80 struct ocfs2_cluster_connection *lksb_conn;
Joel Becker8f2c9c12008-02-01 12:16:57 -080081};
82
Joel Beckere3dad422008-02-01 15:02:36 -080083/*
Joel Beckera796d282010-01-28 19:22:39 -080084 * The ocfs2_locking_protocol defines the handlers called on ocfs2's behalf.
85 */
86struct ocfs2_locking_protocol {
87 struct ocfs2_protocol_version lp_max_version;
Joel Beckerc0e41332010-01-29 14:46:44 -080088 void (*lp_lock_ast)(struct ocfs2_dlm_lksb *lksb);
89 void (*lp_blocking_ast)(struct ocfs2_dlm_lksb *lksb, int level);
90 void (*lp_unlock_ast)(struct ocfs2_dlm_lksb *lksb, int error);
Joel Beckera796d282010-01-28 19:22:39 -080091};
92
93
94/*
Joel Beckere3dad422008-02-01 15:02:36 -080095 * A cluster connection. Mostly opaque to ocfs2, the connection holds
96 * state for the underlying stack. ocfs2 does use cc_version to determine
97 * locking compatibility.
98 */
Joel Becker4670c462008-02-01 14:39:35 -080099struct ocfs2_cluster_connection {
100 char cc_name[GROUP_NAME_MAX];
101 int cc_namelen;
102 struct ocfs2_protocol_version cc_version;
Joel Becker110946c2010-01-29 15:46:23 -0800103 struct ocfs2_locking_protocol *cc_proto;
Joel Becker4670c462008-02-01 14:39:35 -0800104 void (*cc_recovery_handler)(int node_num, void *recovery_data);
105 void *cc_recovery_data;
106 void *cc_lockspace;
107 void *cc_private;
108};
109
Joel Beckere3dad422008-02-01 15:02:36 -0800110/*
111 * Each cluster stack implements the stack operations structure. Not used
112 * in the ocfs2 code, the stackglue code translates generic cluster calls
113 * into stack operations.
114 */
115struct ocfs2_stack_operations {
116 /*
117 * The fs code calls ocfs2_cluster_connect() to attach a new
118 * filesystem to the cluster stack. The ->connect() op is passed
119 * an ocfs2_cluster_connection with the name and recovery field
120 * filled in.
121 *
122 * The stack must set up any notification mechanisms and create
123 * the filesystem lockspace in the DLM. The lockspace should be
124 * stored on cc_lockspace. Any other information can be stored on
125 * cc_private.
126 *
127 * ->connect() must not return until it is guaranteed that
128 *
129 * - Node down notifications for the filesystem will be recieved
130 * and passed to conn->cc_recovery_handler().
131 * - Locking requests for the filesystem will be processed.
132 */
133 int (*connect)(struct ocfs2_cluster_connection *conn);
134
135 /*
136 * The fs code calls ocfs2_cluster_disconnect() when a filesystem
137 * no longer needs cluster services. All DLM locks have been
138 * dropped, and recovery notification is being ignored by the
139 * fs code. The stack must disengage from the DLM and discontinue
140 * recovery notification.
141 *
142 * Once ->disconnect() has returned, the connection structure will
143 * be freed. Thus, a stack must not return from ->disconnect()
144 * until it will no longer reference the conn pointer.
Joel Becker286eaa92008-02-01 15:03:57 -0800145 *
Joel Becker2c394502008-05-30 15:58:26 -0700146 * Once this call returns, the stack glue will be dropping this
147 * connection's reference on the module.
Joel Beckere3dad422008-02-01 15:02:36 -0800148 */
Joel Becker2c394502008-05-30 15:58:26 -0700149 int (*disconnect)(struct ocfs2_cluster_connection *conn);
Joel Beckere3dad422008-02-01 15:02:36 -0800150
151 /*
152 * ->this_node() returns the cluster's unique identifier for the
153 * local node.
154 */
155 int (*this_node)(unsigned int *node);
156
157 /*
158 * Call the underlying dlm lock function. The ->dlm_lock()
159 * callback should convert the flags and mode as appropriate.
160 *
161 * ast and bast functions are not part of the call because the
162 * stack will likely want to wrap ast and bast calls before passing
Joel Beckera796d282010-01-28 19:22:39 -0800163 * them to stack->sp_proto. There is no astarg. The lksb will
164 * be passed back to the ast and bast functions. The caller can
165 * use this to find their object.
Joel Beckere3dad422008-02-01 15:02:36 -0800166 */
167 int (*dlm_lock)(struct ocfs2_cluster_connection *conn,
168 int mode,
Joel Beckerc0e41332010-01-29 14:46:44 -0800169 struct ocfs2_dlm_lksb *lksb,
Joel Beckere3dad422008-02-01 15:02:36 -0800170 u32 flags,
171 void *name,
Joel Beckera796d282010-01-28 19:22:39 -0800172 unsigned int namelen);
Joel Beckere3dad422008-02-01 15:02:36 -0800173
174 /*
175 * Call the underlying dlm unlock function. The ->dlm_unlock()
176 * function should convert the flags as appropriate.
177 *
178 * The unlock ast is not passed, as the stack will want to wrap
Joel Beckera796d282010-01-28 19:22:39 -0800179 * it before calling stack->sp_proto->lp_unlock_ast(). There is
180 * no astarg. The lksb will be passed back to the unlock ast
181 * function. The caller can use this to find their object.
Joel Beckere3dad422008-02-01 15:02:36 -0800182 */
183 int (*dlm_unlock)(struct ocfs2_cluster_connection *conn,
Joel Beckerc0e41332010-01-29 14:46:44 -0800184 struct ocfs2_dlm_lksb *lksb,
Joel Beckera796d282010-01-28 19:22:39 -0800185 u32 flags);
Joel Beckere3dad422008-02-01 15:02:36 -0800186
187 /*
188 * Return the status of the current lock status block. The fs
189 * code should never dereference the union. The ->lock_status()
190 * callback pulls out the stack-specific lksb, converts the status
191 * to a proper errno, and returns it.
192 */
Joel Beckerc0e41332010-01-29 14:46:44 -0800193 int (*lock_status)(struct ocfs2_dlm_lksb *lksb);
Joel Beckere3dad422008-02-01 15:02:36 -0800194
195 /*
Joel Becker1c520df2009-06-19 15:14:13 -0700196 * Return non-zero if the LVB is valid.
197 */
Joel Beckerc0e41332010-01-29 14:46:44 -0800198 int (*lvb_valid)(struct ocfs2_dlm_lksb *lksb);
Joel Becker1c520df2009-06-19 15:14:13 -0700199
200 /*
Joel Beckere3dad422008-02-01 15:02:36 -0800201 * Pull the lvb pointer off of the stack-specific lksb.
202 */
Joel Beckerc0e41332010-01-29 14:46:44 -0800203 void *(*lock_lvb)(struct ocfs2_dlm_lksb *lksb);
Joel Beckere3dad422008-02-01 15:02:36 -0800204
205 /*
Mark Fasheh53da4932008-07-21 14:29:16 -0700206 * Cluster-aware posix locks
207 *
208 * This is NULL for stacks which do not support posix locks.
209 */
210 int (*plock)(struct ocfs2_cluster_connection *conn,
211 u64 ino,
212 struct file *file,
213 int cmd,
214 struct file_lock *fl);
215
216 /*
Joel Beckere3dad422008-02-01 15:02:36 -0800217 * This is an optoinal debugging hook. If provided, the
218 * stack can dump debugging information about this lock.
219 */
Joel Beckerc0e41332010-01-29 14:46:44 -0800220 void (*dump_lksb)(struct ocfs2_dlm_lksb *lksb);
Joel Beckere3dad422008-02-01 15:02:36 -0800221};
222
Joel Becker286eaa92008-02-01 15:03:57 -0800223/*
224 * Each stack plugin must describe itself by registering a
225 * ocfs2_stack_plugin structure. This is only seen by stackglue and the
226 * stack driver.
227 */
228struct ocfs2_stack_plugin {
229 char *sp_name;
230 struct ocfs2_stack_operations *sp_ops;
231 struct module *sp_owner;
232
233 /* These are managed by the stackglue code. */
234 struct list_head sp_list;
235 unsigned int sp_count;
Joel Beckere603cfb2010-01-29 16:06:29 -0800236 struct ocfs2_protocol_version sp_max_proto;
Joel Becker286eaa92008-02-01 15:03:57 -0800237};
238
239
240/* Used by the filesystem */
Joel Becker9c6c8772008-02-01 15:17:30 -0800241int ocfs2_cluster_connect(const char *stack_name,
242 const char *group,
Joel Becker4670c462008-02-01 14:39:35 -0800243 int grouplen,
Joel Becker553b5eb2010-01-29 17:19:06 -0800244 struct ocfs2_locking_protocol *lproto,
Joel Becker4670c462008-02-01 14:39:35 -0800245 void (*recovery_handler)(int node_num,
246 void *recovery_data),
247 void *recovery_data,
248 struct ocfs2_cluster_connection **conn);
Joel Beckercbe0e332010-01-30 06:02:10 -0800249/*
250 * Used by callers that don't store their stack name. They must ensure
251 * all nodes have the same stack.
252 */
253int ocfs2_cluster_connect_agnostic(const char *group,
254 int grouplen,
255 struct ocfs2_locking_protocol *lproto,
256 void (*recovery_handler)(int node_num,
257 void *recovery_data),
258 void *recovery_data,
259 struct ocfs2_cluster_connection **conn);
Joel Becker286eaa92008-02-01 15:03:57 -0800260int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn,
261 int hangup_pending);
Joel Becker6953b4c2008-01-29 16:59:56 -0800262void ocfs2_cluster_hangup(const char *group, int grouplen);
Joel Becker19fdb622008-01-30 15:38:24 -0800263int ocfs2_cluster_this_node(unsigned int *node);
Joel Becker4670c462008-02-01 14:39:35 -0800264
David Teiglandcf4d8d72008-02-20 14:29:27 -0800265struct ocfs2_lock_res;
Joel Becker4670c462008-02-01 14:39:35 -0800266int ocfs2_dlm_lock(struct ocfs2_cluster_connection *conn,
Joel Becker24ef1812008-01-29 17:37:32 -0800267 int mode,
Joel Beckerc0e41332010-01-29 14:46:44 -0800268 struct ocfs2_dlm_lksb *lksb,
Joel Becker24ef1812008-01-29 17:37:32 -0800269 u32 flags,
270 void *name,
Joel Beckera796d282010-01-28 19:22:39 -0800271 unsigned int namelen);
Joel Becker4670c462008-02-01 14:39:35 -0800272int ocfs2_dlm_unlock(struct ocfs2_cluster_connection *conn,
Joel Beckerc0e41332010-01-29 14:46:44 -0800273 struct ocfs2_dlm_lksb *lksb,
Joel Beckera796d282010-01-28 19:22:39 -0800274 u32 flags);
Joel Becker24ef1812008-01-29 17:37:32 -0800275
Joel Beckerc0e41332010-01-29 14:46:44 -0800276int ocfs2_dlm_lock_status(struct ocfs2_dlm_lksb *lksb);
277int ocfs2_dlm_lvb_valid(struct ocfs2_dlm_lksb *lksb);
278void *ocfs2_dlm_lvb(struct ocfs2_dlm_lksb *lksb);
279void ocfs2_dlm_dump_lksb(struct ocfs2_dlm_lksb *lksb);
Joel Becker8f2c9c12008-02-01 12:16:57 -0800280
Mark Fasheh53da4932008-07-21 14:29:16 -0700281int ocfs2_stack_supports_plocks(void);
282int ocfs2_plock(struct ocfs2_cluster_connection *conn, u64 ino,
283 struct file *file, int cmd, struct file_lock *fl);
284
Joel Becker553b5eb2010-01-29 17:19:06 -0800285void ocfs2_stack_glue_set_max_proto_version(struct ocfs2_protocol_version *max_proto);
Joel Becker24ef1812008-01-29 17:37:32 -0800286
Joel Becker286eaa92008-02-01 15:03:57 -0800287
288/* Used by stack plugins */
289int ocfs2_stack_glue_register(struct ocfs2_stack_plugin *plugin);
290void ocfs2_stack_glue_unregister(struct ocfs2_stack_plugin *plugin);
Joel Becker3878f112008-05-30 15:30:49 -0700291
Joel Becker24ef1812008-01-29 17:37:32 -0800292#endif /* STACKGLUE_H */