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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/* Needed for plock-related prototypes */
32struct file;
33struct file_lock;
34
35/*
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
42/*
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/* This shadows OCFS2_CLUSTER_NAME_LEN */
49#define CLUSTER_NAME_MAX 16
50
51
52/*
53 * ocfs2_protocol_version changes when ocfs2 does something different in
54 * its inter-node behavior. See dlmglue.c for more information.
55 */
56struct ocfs2_protocol_version {
57 u8 pv_major;
58 u8 pv_minor;
59};
60
61/*
62 * The dlm_lockstatus struct includes lvb space, but the dlm_lksb struct only
63 * has a pointer to separately allocated lvb space. This struct exists only to
64 * include in the lksb union to make space for a combined dlm_lksb and lvb.
65 */
66struct fsdlm_lksb_plus_lvb {
67 struct dlm_lksb lksb;
68 char lvb[DLM_LVB_LEN];
69};
70
71/*
72 * A union of all lock status structures. We define it here so that the
73 * size of the union is known. Lock status structures are embedded in
74 * ocfs2 inodes.
75 */
76struct ocfs2_cluster_connection;
77struct ocfs2_dlm_lksb {
78 union {
79 struct dlm_lockstatus lksb_o2dlm;
80 struct dlm_lksb lksb_fsdlm;
81 struct fsdlm_lksb_plus_lvb padding;
82 };
83 struct ocfs2_cluster_connection *lksb_conn;
84};
85
86/*
87 * The ocfs2_locking_protocol defines the handlers called on ocfs2's behalf.
88 */
89struct ocfs2_locking_protocol {
90 struct ocfs2_protocol_version lp_max_version;
91 void (*lp_lock_ast)(struct ocfs2_dlm_lksb *lksb);
92 void (*lp_blocking_ast)(struct ocfs2_dlm_lksb *lksb, int level);
93 void (*lp_unlock_ast)(struct ocfs2_dlm_lksb *lksb, int error);
94};
95
96
97/*
98 * A cluster connection. Mostly opaque to ocfs2, the connection holds
99 * state for the underlying stack. ocfs2 does use cc_version to determine
100 * locking compatibility.
101 */
102struct ocfs2_cluster_connection {
103 char cc_name[GROUP_NAME_MAX + 1];
104 int cc_namelen;
105 char cc_cluster_name[CLUSTER_NAME_MAX + 1];
106 int cc_cluster_name_len;
107 struct ocfs2_protocol_version cc_version;
108 struct ocfs2_locking_protocol *cc_proto;
109 void (*cc_recovery_handler)(int node_num, void *recovery_data);
110 void *cc_recovery_data;
111 void *cc_lockspace;
112 void *cc_private;
113};
114
115/*
116 * Each cluster stack implements the stack operations structure. Not used
117 * in the ocfs2 code, the stackglue code translates generic cluster calls
118 * into stack operations.
119 */
120struct ocfs2_stack_operations {
121 /*
122 * The fs code calls ocfs2_cluster_connect() to attach a new
123 * filesystem to the cluster stack. The ->connect() op is passed
124 * an ocfs2_cluster_connection with the name and recovery field
125 * filled in.
126 *
127 * The stack must set up any notification mechanisms and create
128 * the filesystem lockspace in the DLM. The lockspace should be
129 * stored on cc_lockspace. Any other information can be stored on
130 * cc_private.
131 *
132 * ->connect() must not return until it is guaranteed that
133 *
134 * - Node down notifications for the filesystem will be received
135 * and passed to conn->cc_recovery_handler().
136 * - Locking requests for the filesystem will be processed.
137 */
138 int (*connect)(struct ocfs2_cluster_connection *conn);
139
140 /*
141 * The fs code calls ocfs2_cluster_disconnect() when a filesystem
142 * no longer needs cluster services. All DLM locks have been
143 * dropped, and recovery notification is being ignored by the
144 * fs code. The stack must disengage from the DLM and discontinue
145 * recovery notification.
146 *
147 * Once ->disconnect() has returned, the connection structure will
148 * be freed. Thus, a stack must not return from ->disconnect()
149 * until it will no longer reference the conn pointer.
150 *
151 * Once this call returns, the stack glue will be dropping this
152 * connection's reference on the module.
153 */
154 int (*disconnect)(struct ocfs2_cluster_connection *conn);
155
156 /*
157 * ->this_node() returns the cluster's unique identifier for the
158 * local node.
159 */
160 int (*this_node)(struct ocfs2_cluster_connection *conn,
161 unsigned int *node);
162
163 /*
164 * Call the underlying dlm lock function. The ->dlm_lock()
165 * callback should convert the flags and mode as appropriate.
166 *
167 * ast and bast functions are not part of the call because the
168 * stack will likely want to wrap ast and bast calls before passing
169 * them to stack->sp_proto. There is no astarg. The lksb will
170 * be passed back to the ast and bast functions. The caller can
171 * use this to find their object.
172 */
173 int (*dlm_lock)(struct ocfs2_cluster_connection *conn,
174 int mode,
175 struct ocfs2_dlm_lksb *lksb,
176 u32 flags,
177 void *name,
178 unsigned int namelen);
179
180 /*
181 * Call the underlying dlm unlock function. The ->dlm_unlock()
182 * function should convert the flags as appropriate.
183 *
184 * The unlock ast is not passed, as the stack will want to wrap
185 * it before calling stack->sp_proto->lp_unlock_ast(). There is
186 * no astarg. The lksb will be passed back to the unlock ast
187 * function. The caller can use this to find their object.
188 */
189 int (*dlm_unlock)(struct ocfs2_cluster_connection *conn,
190 struct ocfs2_dlm_lksb *lksb,
191 u32 flags);
192
193 /*
194 * Return the status of the current lock status block. The fs
195 * code should never dereference the union. The ->lock_status()
196 * callback pulls out the stack-specific lksb, converts the status
197 * to a proper errno, and returns it.
198 */
199 int (*lock_status)(struct ocfs2_dlm_lksb *lksb);
200
201 /*
202 * Return non-zero if the LVB is valid.
203 */
204 int (*lvb_valid)(struct ocfs2_dlm_lksb *lksb);
205
206 /*
207 * Pull the lvb pointer off of the stack-specific lksb.
208 */
209 void *(*lock_lvb)(struct ocfs2_dlm_lksb *lksb);
210
211 /*
212 * Cluster-aware posix locks
213 *
214 * This is NULL for stacks which do not support posix locks.
215 */
216 int (*plock)(struct ocfs2_cluster_connection *conn,
217 u64 ino,
218 struct file *file,
219 int cmd,
220 struct file_lock *fl);
221
222 /*
223 * This is an optoinal debugging hook. If provided, the
224 * stack can dump debugging information about this lock.
225 */
226 void (*dump_lksb)(struct ocfs2_dlm_lksb *lksb);
227};
228
229/*
230 * Each stack plugin must describe itself by registering a
231 * ocfs2_stack_plugin structure. This is only seen by stackglue and the
232 * stack driver.
233 */
234struct ocfs2_stack_plugin {
235 char *sp_name;
236 struct ocfs2_stack_operations *sp_ops;
237 struct module *sp_owner;
238
239 /* These are managed by the stackglue code. */
240 struct list_head sp_list;
241 unsigned int sp_count;
242 struct ocfs2_protocol_version sp_max_proto;
243};
244
245
246/* Used by the filesystem */
247int ocfs2_cluster_connect(const char *stack_name,
248 const char *cluster_name,
249 int cluster_name_len,
250 const char *group,
251 int grouplen,
252 struct ocfs2_locking_protocol *lproto,
253 void (*recovery_handler)(int node_num,
254 void *recovery_data),
255 void *recovery_data,
256 struct ocfs2_cluster_connection **conn);
257/*
258 * Used by callers that don't store their stack name. They must ensure
259 * all nodes have the same stack.
260 */
261int ocfs2_cluster_connect_agnostic(const char *group,
262 int grouplen,
263 struct ocfs2_locking_protocol *lproto,
264 void (*recovery_handler)(int node_num,
265 void *recovery_data),
266 void *recovery_data,
267 struct ocfs2_cluster_connection **conn);
268int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn,
269 int hangup_pending);
270void ocfs2_cluster_hangup(const char *group, int grouplen);
271int ocfs2_cluster_this_node(struct ocfs2_cluster_connection *conn,
272 unsigned int *node);
273
274struct ocfs2_lock_res;
275int ocfs2_dlm_lock(struct ocfs2_cluster_connection *conn,
276 int mode,
277 struct ocfs2_dlm_lksb *lksb,
278 u32 flags,
279 void *name,
280 unsigned int namelen);
281int ocfs2_dlm_unlock(struct ocfs2_cluster_connection *conn,
282 struct ocfs2_dlm_lksb *lksb,
283 u32 flags);
284
285int ocfs2_dlm_lock_status(struct ocfs2_dlm_lksb *lksb);
286int ocfs2_dlm_lvb_valid(struct ocfs2_dlm_lksb *lksb);
287void *ocfs2_dlm_lvb(struct ocfs2_dlm_lksb *lksb);
288void ocfs2_dlm_dump_lksb(struct ocfs2_dlm_lksb *lksb);
289
290int ocfs2_stack_supports_plocks(void);
291int ocfs2_plock(struct ocfs2_cluster_connection *conn, u64 ino,
292 struct file *file, int cmd, struct file_lock *fl);
293
294void ocfs2_stack_glue_set_max_proto_version(struct ocfs2_protocol_version *max_proto);
295
296
297/* Used by stack plugins */
298int ocfs2_stack_glue_register(struct ocfs2_stack_plugin *plugin);
299void ocfs2_stack_glue_unregister(struct ocfs2_stack_plugin *plugin);
300
301#endif /* STACKGLUE_H */
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * stackglue.h
4 *
5 * Glue to the underlying cluster stack.
6 *
7 * Copyright (C) 2007 Oracle. All rights reserved.
8 */
9
10
11#ifndef STACKGLUE_H
12#define STACKGLUE_H
13
14#include <linux/types.h>
15#include <linux/list.h>
16#include <linux/dlmconstants.h>
17
18#include "dlm/dlmapi.h"
19#include <linux/dlm.h>
20
21/* Needed for plock-related prototypes */
22struct file;
23struct file_lock;
24
25/*
26 * dlmconstants.h does not have a LOCAL flag. We hope to remove it
27 * some day, but right now we need it. Let's fake it. This value is larger
28 * than any flag in dlmconstants.h.
29 */
30#define DLM_LKF_LOCAL 0x00100000
31
32/*
33 * This shadows DLM_LOCKSPACE_LEN in fs/dlm/dlm_internal.h. That probably
34 * wants to be in a public header.
35 */
36#define GROUP_NAME_MAX 64
37
38/* This shadows OCFS2_CLUSTER_NAME_LEN */
39#define CLUSTER_NAME_MAX 16
40
41
42/*
43 * ocfs2_protocol_version changes when ocfs2 does something different in
44 * its inter-node behavior. See dlmglue.c for more information.
45 */
46struct ocfs2_protocol_version {
47 u8 pv_major;
48 u8 pv_minor;
49};
50
51/*
52 * The dlm_lockstatus struct includes lvb space, but the dlm_lksb struct only
53 * has a pointer to separately allocated lvb space. This struct exists only to
54 * include in the lksb union to make space for a combined dlm_lksb and lvb.
55 */
56struct fsdlm_lksb_plus_lvb {
57 struct dlm_lksb lksb;
58 char lvb[DLM_LVB_LEN];
59};
60
61/*
62 * A union of all lock status structures. We define it here so that the
63 * size of the union is known. Lock status structures are embedded in
64 * ocfs2 inodes.
65 */
66struct ocfs2_cluster_connection;
67struct ocfs2_dlm_lksb {
68 union {
69 struct dlm_lockstatus lksb_o2dlm;
70 struct dlm_lksb lksb_fsdlm;
71 struct fsdlm_lksb_plus_lvb padding;
72 };
73 struct ocfs2_cluster_connection *lksb_conn;
74};
75
76/*
77 * The ocfs2_locking_protocol defines the handlers called on ocfs2's behalf.
78 */
79struct ocfs2_locking_protocol {
80 struct ocfs2_protocol_version lp_max_version;
81 void (*lp_lock_ast)(struct ocfs2_dlm_lksb *lksb);
82 void (*lp_blocking_ast)(struct ocfs2_dlm_lksb *lksb, int level);
83 void (*lp_unlock_ast)(struct ocfs2_dlm_lksb *lksb, int error);
84};
85
86
87/*
88 * A cluster connection. Mostly opaque to ocfs2, the connection holds
89 * state for the underlying stack. ocfs2 does use cc_version to determine
90 * locking compatibility.
91 */
92struct ocfs2_cluster_connection {
93 char cc_name[GROUP_NAME_MAX + 1];
94 int cc_namelen;
95 char cc_cluster_name[CLUSTER_NAME_MAX + 1];
96 int cc_cluster_name_len;
97 struct ocfs2_protocol_version cc_version;
98 struct ocfs2_locking_protocol *cc_proto;
99 void (*cc_recovery_handler)(int node_num, void *recovery_data);
100 void *cc_recovery_data;
101 void *cc_lockspace;
102 void *cc_private;
103};
104
105/*
106 * Each cluster stack implements the stack operations structure. Not used
107 * in the ocfs2 code, the stackglue code translates generic cluster calls
108 * into stack operations.
109 */
110struct ocfs2_stack_operations {
111 /*
112 * The fs code calls ocfs2_cluster_connect() to attach a new
113 * filesystem to the cluster stack. The ->connect() op is passed
114 * an ocfs2_cluster_connection with the name and recovery field
115 * filled in.
116 *
117 * The stack must set up any notification mechanisms and create
118 * the filesystem lockspace in the DLM. The lockspace should be
119 * stored on cc_lockspace. Any other information can be stored on
120 * cc_private.
121 *
122 * ->connect() must not return until it is guaranteed that
123 *
124 * - Node down notifications for the filesystem will be received
125 * and passed to conn->cc_recovery_handler().
126 * - Locking requests for the filesystem will be processed.
127 */
128 int (*connect)(struct ocfs2_cluster_connection *conn);
129
130 /*
131 * The fs code calls ocfs2_cluster_disconnect() when a filesystem
132 * no longer needs cluster services. All DLM locks have been
133 * dropped, and recovery notification is being ignored by the
134 * fs code. The stack must disengage from the DLM and discontinue
135 * recovery notification.
136 *
137 * Once ->disconnect() has returned, the connection structure will
138 * be freed. Thus, a stack must not return from ->disconnect()
139 * until it will no longer reference the conn pointer.
140 *
141 * Once this call returns, the stack glue will be dropping this
142 * connection's reference on the module.
143 */
144 int (*disconnect)(struct ocfs2_cluster_connection *conn);
145
146 /*
147 * ->this_node() returns the cluster's unique identifier for the
148 * local node.
149 */
150 int (*this_node)(struct ocfs2_cluster_connection *conn,
151 unsigned int *node);
152
153 /*
154 * Call the underlying dlm lock function. The ->dlm_lock()
155 * callback should convert the flags and mode as appropriate.
156 *
157 * ast and bast functions are not part of the call because the
158 * stack will likely want to wrap ast and bast calls before passing
159 * them to stack->sp_proto. There is no astarg. The lksb will
160 * be passed back to the ast and bast functions. The caller can
161 * use this to find their object.
162 */
163 int (*dlm_lock)(struct ocfs2_cluster_connection *conn,
164 int mode,
165 struct ocfs2_dlm_lksb *lksb,
166 u32 flags,
167 void *name,
168 unsigned int namelen);
169
170 /*
171 * Call the underlying dlm unlock function. The ->dlm_unlock()
172 * function should convert the flags as appropriate.
173 *
174 * The unlock ast is not passed, as the stack will want to wrap
175 * it before calling stack->sp_proto->lp_unlock_ast(). There is
176 * no astarg. The lksb will be passed back to the unlock ast
177 * function. The caller can use this to find their object.
178 */
179 int (*dlm_unlock)(struct ocfs2_cluster_connection *conn,
180 struct ocfs2_dlm_lksb *lksb,
181 u32 flags);
182
183 /*
184 * Return the status of the current lock status block. The fs
185 * code should never dereference the union. The ->lock_status()
186 * callback pulls out the stack-specific lksb, converts the status
187 * to a proper errno, and returns it.
188 */
189 int (*lock_status)(struct ocfs2_dlm_lksb *lksb);
190
191 /*
192 * Return non-zero if the LVB is valid.
193 */
194 int (*lvb_valid)(struct ocfs2_dlm_lksb *lksb);
195
196 /*
197 * Pull the lvb pointer off of the stack-specific lksb.
198 */
199 void *(*lock_lvb)(struct ocfs2_dlm_lksb *lksb);
200
201 /*
202 * Cluster-aware posix locks
203 *
204 * This is NULL for stacks which do not support posix locks.
205 */
206 int (*plock)(struct ocfs2_cluster_connection *conn,
207 u64 ino,
208 struct file *file,
209 int cmd,
210 struct file_lock *fl);
211
212 /*
213 * This is an optoinal debugging hook. If provided, the
214 * stack can dump debugging information about this lock.
215 */
216 void (*dump_lksb)(struct ocfs2_dlm_lksb *lksb);
217};
218
219/*
220 * Each stack plugin must describe itself by registering a
221 * ocfs2_stack_plugin structure. This is only seen by stackglue and the
222 * stack driver.
223 */
224struct ocfs2_stack_plugin {
225 char *sp_name;
226 struct ocfs2_stack_operations *sp_ops;
227 struct module *sp_owner;
228
229 /* These are managed by the stackglue code. */
230 struct list_head sp_list;
231 unsigned int sp_count;
232 struct ocfs2_protocol_version sp_max_proto;
233};
234
235
236/* Used by the filesystem */
237int ocfs2_cluster_connect(const char *stack_name,
238 const char *cluster_name,
239 int cluster_name_len,
240 const char *group,
241 int grouplen,
242 struct ocfs2_locking_protocol *lproto,
243 void (*recovery_handler)(int node_num,
244 void *recovery_data),
245 void *recovery_data,
246 struct ocfs2_cluster_connection **conn);
247/*
248 * Used by callers that don't store their stack name. They must ensure
249 * all nodes have the same stack.
250 */
251int ocfs2_cluster_connect_agnostic(const char *group,
252 int grouplen,
253 struct ocfs2_locking_protocol *lproto,
254 void (*recovery_handler)(int node_num,
255 void *recovery_data),
256 void *recovery_data,
257 struct ocfs2_cluster_connection **conn);
258int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn,
259 int hangup_pending);
260void ocfs2_cluster_hangup(const char *group, int grouplen);
261int ocfs2_cluster_this_node(struct ocfs2_cluster_connection *conn,
262 unsigned int *node);
263
264struct ocfs2_lock_res;
265int ocfs2_dlm_lock(struct ocfs2_cluster_connection *conn,
266 int mode,
267 struct ocfs2_dlm_lksb *lksb,
268 u32 flags,
269 void *name,
270 unsigned int namelen);
271int ocfs2_dlm_unlock(struct ocfs2_cluster_connection *conn,
272 struct ocfs2_dlm_lksb *lksb,
273 u32 flags);
274
275int ocfs2_dlm_lock_status(struct ocfs2_dlm_lksb *lksb);
276int ocfs2_dlm_lvb_valid(struct ocfs2_dlm_lksb *lksb);
277void *ocfs2_dlm_lvb(struct ocfs2_dlm_lksb *lksb);
278void ocfs2_dlm_dump_lksb(struct ocfs2_dlm_lksb *lksb);
279
280int ocfs2_stack_supports_plocks(void);
281int ocfs2_plock(struct ocfs2_cluster_connection *conn, u64 ino,
282 struct file *file, int cmd, struct file_lock *fl);
283
284void ocfs2_stack_glue_set_max_proto_version(struct ocfs2_protocol_version *max_proto);
285
286
287/* Used by stack plugins */
288int ocfs2_stack_glue_register(struct ocfs2_stack_plugin *plugin);
289void ocfs2_stack_glue_unregister(struct ocfs2_stack_plugin *plugin);
290
291extern struct kset *ocfs2_kset;
292
293#endif /* STACKGLUE_H */