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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 Becker8f2c9c12008-02-01 12:16:57 -080073union ocfs2_dlm_lksb {
74 struct dlm_lockstatus lksb_o2dlm;
David Teiglandcf4d8d72008-02-20 14:29:27 -080075 struct dlm_lksb lksb_fsdlm;
76 struct fsdlm_lksb_plus_lvb padding;
Joel Becker8f2c9c12008-02-01 12:16:57 -080077};
78
Joel Beckere3dad422008-02-01 15:02:36 -080079/*
Joel Beckera796d282010-01-28 19:22:39 -080080 * The ocfs2_locking_protocol defines the handlers called on ocfs2's behalf.
81 */
82struct ocfs2_locking_protocol {
83 struct ocfs2_protocol_version lp_max_version;
84 void (*lp_lock_ast)(union ocfs2_dlm_lksb *lksb);
85 void (*lp_blocking_ast)(union ocfs2_dlm_lksb *lksb, int level);
86 void (*lp_unlock_ast)(union ocfs2_dlm_lksb *lksb, int error);
87};
88
89
90/*
Joel Beckere3dad422008-02-01 15:02:36 -080091 * A cluster connection. Mostly opaque to ocfs2, the connection holds
92 * state for the underlying stack. ocfs2 does use cc_version to determine
93 * locking compatibility.
94 */
Joel Becker4670c462008-02-01 14:39:35 -080095struct ocfs2_cluster_connection {
96 char cc_name[GROUP_NAME_MAX];
97 int cc_namelen;
98 struct ocfs2_protocol_version cc_version;
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
Joel Beckere3dad422008-02-01 15:02:36 -0800105/*
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 recieved
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.
Joel Becker286eaa92008-02-01 15:03:57 -0800140 *
Joel Becker2c394502008-05-30 15:58:26 -0700141 * Once this call returns, the stack glue will be dropping this
142 * connection's reference on the module.
Joel Beckere3dad422008-02-01 15:02:36 -0800143 */
Joel Becker2c394502008-05-30 15:58:26 -0700144 int (*disconnect)(struct ocfs2_cluster_connection *conn);
Joel Beckere3dad422008-02-01 15:02:36 -0800145
146 /*
147 * ->this_node() returns the cluster's unique identifier for the
148 * local node.
149 */
150 int (*this_node)(unsigned int *node);
151
152 /*
153 * Call the underlying dlm lock function. The ->dlm_lock()
154 * callback should convert the flags and mode as appropriate.
155 *
156 * ast and bast functions are not part of the call because the
157 * stack will likely want to wrap ast and bast calls before passing
Joel Beckera796d282010-01-28 19:22:39 -0800158 * them to stack->sp_proto. There is no astarg. The lksb will
159 * be passed back to the ast and bast functions. The caller can
160 * use this to find their object.
Joel Beckere3dad422008-02-01 15:02:36 -0800161 */
162 int (*dlm_lock)(struct ocfs2_cluster_connection *conn,
163 int mode,
164 union ocfs2_dlm_lksb *lksb,
165 u32 flags,
166 void *name,
Joel Beckera796d282010-01-28 19:22:39 -0800167 unsigned int namelen);
Joel Beckere3dad422008-02-01 15:02:36 -0800168
169 /*
170 * Call the underlying dlm unlock function. The ->dlm_unlock()
171 * function should convert the flags as appropriate.
172 *
173 * The unlock ast is not passed, as the stack will want to wrap
Joel Beckera796d282010-01-28 19:22:39 -0800174 * it before calling stack->sp_proto->lp_unlock_ast(). There is
175 * no astarg. The lksb will be passed back to the unlock ast
176 * function. The caller can use this to find their object.
Joel Beckere3dad422008-02-01 15:02:36 -0800177 */
178 int (*dlm_unlock)(struct ocfs2_cluster_connection *conn,
179 union ocfs2_dlm_lksb *lksb,
Joel Beckera796d282010-01-28 19:22:39 -0800180 u32 flags);
Joel Beckere3dad422008-02-01 15:02:36 -0800181
182 /*
183 * Return the status of the current lock status block. The fs
184 * code should never dereference the union. The ->lock_status()
185 * callback pulls out the stack-specific lksb, converts the status
186 * to a proper errno, and returns it.
187 */
188 int (*lock_status)(union ocfs2_dlm_lksb *lksb);
189
190 /*
Joel Becker1c520df2009-06-19 15:14:13 -0700191 * Return non-zero if the LVB is valid.
192 */
193 int (*lvb_valid)(union ocfs2_dlm_lksb *lksb);
194
195 /*
Joel Beckere3dad422008-02-01 15:02:36 -0800196 * Pull the lvb pointer off of the stack-specific lksb.
197 */
198 void *(*lock_lvb)(union ocfs2_dlm_lksb *lksb);
199
200 /*
Mark Fasheh53da4932008-07-21 14:29:16 -0700201 * Cluster-aware posix locks
202 *
203 * This is NULL for stacks which do not support posix locks.
204 */
205 int (*plock)(struct ocfs2_cluster_connection *conn,
206 u64 ino,
207 struct file *file,
208 int cmd,
209 struct file_lock *fl);
210
211 /*
Joel Beckere3dad422008-02-01 15:02:36 -0800212 * This is an optoinal debugging hook. If provided, the
213 * stack can dump debugging information about this lock.
214 */
215 void (*dump_lksb)(union ocfs2_dlm_lksb *lksb);
216};
217
Joel Becker286eaa92008-02-01 15:03:57 -0800218/*
219 * Each stack plugin must describe itself by registering a
220 * ocfs2_stack_plugin structure. This is only seen by stackglue and the
221 * stack driver.
222 */
223struct ocfs2_stack_plugin {
224 char *sp_name;
225 struct ocfs2_stack_operations *sp_ops;
226 struct module *sp_owner;
227
228 /* These are managed by the stackglue code. */
229 struct list_head sp_list;
230 unsigned int sp_count;
231 struct ocfs2_locking_protocol *sp_proto;
232};
233
234
235/* Used by the filesystem */
Joel Becker9c6c8772008-02-01 15:17:30 -0800236int ocfs2_cluster_connect(const char *stack_name,
237 const char *group,
Joel Becker4670c462008-02-01 14:39:35 -0800238 int grouplen,
239 void (*recovery_handler)(int node_num,
240 void *recovery_data),
241 void *recovery_data,
242 struct ocfs2_cluster_connection **conn);
Joel Becker286eaa92008-02-01 15:03:57 -0800243int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn,
244 int hangup_pending);
Joel Becker6953b4c2008-01-29 16:59:56 -0800245void ocfs2_cluster_hangup(const char *group, int grouplen);
Joel Becker19fdb622008-01-30 15:38:24 -0800246int ocfs2_cluster_this_node(unsigned int *node);
Joel Becker4670c462008-02-01 14:39:35 -0800247
David Teiglandcf4d8d72008-02-20 14:29:27 -0800248struct ocfs2_lock_res;
Joel Becker4670c462008-02-01 14:39:35 -0800249int ocfs2_dlm_lock(struct ocfs2_cluster_connection *conn,
Joel Becker24ef1812008-01-29 17:37:32 -0800250 int mode,
Joel Becker8f2c9c12008-02-01 12:16:57 -0800251 union ocfs2_dlm_lksb *lksb,
Joel Becker24ef1812008-01-29 17:37:32 -0800252 u32 flags,
253 void *name,
Joel Beckera796d282010-01-28 19:22:39 -0800254 unsigned int namelen);
Joel Becker4670c462008-02-01 14:39:35 -0800255int ocfs2_dlm_unlock(struct ocfs2_cluster_connection *conn,
Joel Becker8f2c9c12008-02-01 12:16:57 -0800256 union ocfs2_dlm_lksb *lksb,
Joel Beckera796d282010-01-28 19:22:39 -0800257 u32 flags);
Joel Becker24ef1812008-01-29 17:37:32 -0800258
Joel Becker8f2c9c12008-02-01 12:16:57 -0800259int ocfs2_dlm_lock_status(union ocfs2_dlm_lksb *lksb);
Joel Becker1c520df2009-06-19 15:14:13 -0700260int ocfs2_dlm_lvb_valid(union ocfs2_dlm_lksb *lksb);
Joel Becker8f2c9c12008-02-01 12:16:57 -0800261void *ocfs2_dlm_lvb(union ocfs2_dlm_lksb *lksb);
Joel Beckercf0acdc2008-01-29 16:59:55 -0800262void ocfs2_dlm_dump_lksb(union ocfs2_dlm_lksb *lksb);
Joel Becker8f2c9c12008-02-01 12:16:57 -0800263
Mark Fasheh53da4932008-07-21 14:29:16 -0700264int ocfs2_stack_supports_plocks(void);
265int ocfs2_plock(struct ocfs2_cluster_connection *conn, u64 ino,
266 struct file *file, int cmd, struct file_lock *fl);
267
Joel Becker63e0c482008-01-30 16:58:36 -0800268void ocfs2_stack_glue_set_locking_protocol(struct ocfs2_locking_protocol *proto);
Joel Becker24ef1812008-01-29 17:37:32 -0800269
Joel Becker286eaa92008-02-01 15:03:57 -0800270
271/* Used by stack plugins */
272int ocfs2_stack_glue_register(struct ocfs2_stack_plugin *plugin);
273void ocfs2_stack_glue_unregister(struct ocfs2_stack_plugin *plugin);
Joel Becker3878f112008-05-30 15:30:49 -0700274
Joel Becker24ef1812008-01-29 17:37:32 -0800275#endif /* STACKGLUE_H */