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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
Goldwyn Rodriguesc74a3bd2014-01-21 15:48:21 -080048/* This shadows OCFS2_CLUSTER_NAME_LEN */
49#define CLUSTER_NAME_MAX 16
50
Joel Becker4670c462008-02-01 14:39:35 -080051
Joel Beckere3dad422008-02-01 15:02:36 -080052/*
53 * ocfs2_protocol_version changes when ocfs2 does something different in
54 * its inter-node behavior. See dlmglue.c for more information.
55 */
Joel Becker4670c462008-02-01 14:39:35 -080056struct ocfs2_protocol_version {
57 u8 pv_major;
58 u8 pv_minor;
59};
60
Joel Beckere3dad422008-02-01 15:02:36 -080061/*
David Teiglandcf4d8d72008-02-20 14:29:27 -080062 * 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
Joel Beckere3dad422008-02-01 15:02:36 -080071/*
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 */
Joel Beckerc0e41332010-01-29 14:46:44 -080076struct 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;
Joel Becker8f2c9c12008-02-01 12:16:57 -080084};
85
Joel Beckere3dad422008-02-01 15:02:36 -080086/*
Joel Beckera796d282010-01-28 19:22:39 -080087 * 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;
Joel Beckerc0e41332010-01-29 14:46:44 -080091 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);
Joel Beckera796d282010-01-28 19:22:39 -080094};
95
96
97/*
Joel Beckere3dad422008-02-01 15:02:36 -080098 * 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 */
Joel Becker4670c462008-02-01 14:39:35 -0800102struct ocfs2_cluster_connection {
Goldwyn Rodriguesc74a3bd2014-01-21 15:48:21 -0800103 char cc_name[GROUP_NAME_MAX + 1];
Joel Becker4670c462008-02-01 14:39:35 -0800104 int cc_namelen;
Goldwyn Rodriguesc74a3bd2014-01-21 15:48:21 -0800105 char cc_cluster_name[CLUSTER_NAME_MAX + 1];
106 int cc_cluster_name_len;
Joel Becker4670c462008-02-01 14:39:35 -0800107 struct ocfs2_protocol_version cc_version;
Joel Becker110946c2010-01-29 15:46:23 -0800108 struct ocfs2_locking_protocol *cc_proto;
Joel Becker4670c462008-02-01 14:39:35 -0800109 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
Joel Beckere3dad422008-02-01 15:02:36 -0800115/*
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 *
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300134 * - Node down notifications for the filesystem will be received
Joel Beckere3dad422008-02-01 15:02:36 -0800135 * 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.
Joel Becker286eaa92008-02-01 15:03:57 -0800150 *
Joel Becker2c394502008-05-30 15:58:26 -0700151 * Once this call returns, the stack glue will be dropping this
152 * connection's reference on the module.
Joel Beckere3dad422008-02-01 15:02:36 -0800153 */
Joel Becker2c394502008-05-30 15:58:26 -0700154 int (*disconnect)(struct ocfs2_cluster_connection *conn);
Joel Beckere3dad422008-02-01 15:02:36 -0800155
156 /*
157 * ->this_node() returns the cluster's unique identifier for the
158 * local node.
159 */
Goldwyn Rodrigues3e834152014-01-21 15:48:24 -0800160 int (*this_node)(struct ocfs2_cluster_connection *conn,
161 unsigned int *node);
Joel Beckere3dad422008-02-01 15:02:36 -0800162
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
Joel Beckera796d282010-01-28 19:22:39 -0800169 * 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.
Joel Beckere3dad422008-02-01 15:02:36 -0800172 */
173 int (*dlm_lock)(struct ocfs2_cluster_connection *conn,
174 int mode,
Joel Beckerc0e41332010-01-29 14:46:44 -0800175 struct ocfs2_dlm_lksb *lksb,
Joel Beckere3dad422008-02-01 15:02:36 -0800176 u32 flags,
177 void *name,
Joel Beckera796d282010-01-28 19:22:39 -0800178 unsigned int namelen);
Joel Beckere3dad422008-02-01 15:02:36 -0800179
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
Joel Beckera796d282010-01-28 19:22:39 -0800185 * 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.
Joel Beckere3dad422008-02-01 15:02:36 -0800188 */
189 int (*dlm_unlock)(struct ocfs2_cluster_connection *conn,
Joel Beckerc0e41332010-01-29 14:46:44 -0800190 struct ocfs2_dlm_lksb *lksb,
Joel Beckera796d282010-01-28 19:22:39 -0800191 u32 flags);
Joel Beckere3dad422008-02-01 15:02:36 -0800192
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 */
Joel Beckerc0e41332010-01-29 14:46:44 -0800199 int (*lock_status)(struct ocfs2_dlm_lksb *lksb);
Joel Beckere3dad422008-02-01 15:02:36 -0800200
201 /*
Joel Becker1c520df2009-06-19 15:14:13 -0700202 * Return non-zero if the LVB is valid.
203 */
Joel Beckerc0e41332010-01-29 14:46:44 -0800204 int (*lvb_valid)(struct ocfs2_dlm_lksb *lksb);
Joel Becker1c520df2009-06-19 15:14:13 -0700205
206 /*
Joel Beckere3dad422008-02-01 15:02:36 -0800207 * Pull the lvb pointer off of the stack-specific lksb.
208 */
Joel Beckerc0e41332010-01-29 14:46:44 -0800209 void *(*lock_lvb)(struct ocfs2_dlm_lksb *lksb);
Joel Beckere3dad422008-02-01 15:02:36 -0800210
211 /*
Mark Fasheh53da4932008-07-21 14:29:16 -0700212 * 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 /*
Joel Beckere3dad422008-02-01 15:02:36 -0800223 * This is an optoinal debugging hook. If provided, the
224 * stack can dump debugging information about this lock.
225 */
Joel Beckerc0e41332010-01-29 14:46:44 -0800226 void (*dump_lksb)(struct ocfs2_dlm_lksb *lksb);
Joel Beckere3dad422008-02-01 15:02:36 -0800227};
228
Joel Becker286eaa92008-02-01 15:03:57 -0800229/*
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;
Joel Beckere603cfb2010-01-29 16:06:29 -0800242 struct ocfs2_protocol_version sp_max_proto;
Joel Becker286eaa92008-02-01 15:03:57 -0800243};
244
245
246/* Used by the filesystem */
Joel Becker9c6c8772008-02-01 15:17:30 -0800247int ocfs2_cluster_connect(const char *stack_name,
Goldwyn Rodriguesc74a3bd2014-01-21 15:48:21 -0800248 const char *cluster_name,
249 int cluster_name_len,
Joel Becker9c6c8772008-02-01 15:17:30 -0800250 const char *group,
Joel Becker4670c462008-02-01 14:39:35 -0800251 int grouplen,
Joel Becker553b5eb2010-01-29 17:19:06 -0800252 struct ocfs2_locking_protocol *lproto,
Joel Becker4670c462008-02-01 14:39:35 -0800253 void (*recovery_handler)(int node_num,
254 void *recovery_data),
255 void *recovery_data,
256 struct ocfs2_cluster_connection **conn);
Joel Beckercbe0e332010-01-30 06:02:10 -0800257/*
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);
Joel Becker286eaa92008-02-01 15:03:57 -0800268int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn,
269 int hangup_pending);
Joel Becker6953b4c2008-01-29 16:59:56 -0800270void ocfs2_cluster_hangup(const char *group, int grouplen);
Goldwyn Rodrigues3e834152014-01-21 15:48:24 -0800271int ocfs2_cluster_this_node(struct ocfs2_cluster_connection *conn,
272 unsigned int *node);
Joel Becker4670c462008-02-01 14:39:35 -0800273
David Teiglandcf4d8d72008-02-20 14:29:27 -0800274struct ocfs2_lock_res;
Joel Becker4670c462008-02-01 14:39:35 -0800275int ocfs2_dlm_lock(struct ocfs2_cluster_connection *conn,
Joel Becker24ef1812008-01-29 17:37:32 -0800276 int mode,
Joel Beckerc0e41332010-01-29 14:46:44 -0800277 struct ocfs2_dlm_lksb *lksb,
Joel Becker24ef1812008-01-29 17:37:32 -0800278 u32 flags,
279 void *name,
Joel Beckera796d282010-01-28 19:22:39 -0800280 unsigned int namelen);
Joel Becker4670c462008-02-01 14:39:35 -0800281int ocfs2_dlm_unlock(struct ocfs2_cluster_connection *conn,
Joel Beckerc0e41332010-01-29 14:46:44 -0800282 struct ocfs2_dlm_lksb *lksb,
Joel Beckera796d282010-01-28 19:22:39 -0800283 u32 flags);
Joel Becker24ef1812008-01-29 17:37:32 -0800284
Joel Beckerc0e41332010-01-29 14:46:44 -0800285int 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);
Joel Becker8f2c9c12008-02-01 12:16:57 -0800289
Mark Fasheh53da4932008-07-21 14:29:16 -0700290int 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
Joel Becker553b5eb2010-01-29 17:19:06 -0800294void ocfs2_stack_glue_set_max_proto_version(struct ocfs2_protocol_version *max_proto);
Joel Becker24ef1812008-01-29 17:37:32 -0800295
Joel Becker286eaa92008-02-01 15:03:57 -0800296
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);
Joel Becker3878f112008-05-30 15:30:49 -0700300
Joel Becker24ef1812008-01-29 17:37:32 -0800301#endif /* STACKGLUE_H */