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24ef1815 JB |
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 | ||
bd3e7610 JB |
24 | #include <linux/types.h> |
25 | #include <linux/list.h> | |
26 | #include <linux/dlmconstants.h> | |
27 | ||
e3dad42b | 28 | #include "dlm/dlmapi.h" |
cf4d8d75 | 29 | #include <linux/dlm.h> |
e3dad42b | 30 | |
bd3e7610 JB |
31 | /* |
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 | ||
4670c46d JB |
38 | /* |
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 | ||
e3dad42b JB |
45 | /* |
46 | * ocfs2_protocol_version changes when ocfs2 does something different in | |
47 | * its inter-node behavior. See dlmglue.c for more information. | |
48 | */ | |
4670c46d JB |
49 | struct ocfs2_protocol_version { |
50 | u8 pv_major; | |
51 | u8 pv_minor; | |
52 | }; | |
53 | ||
e3dad42b JB |
54 | /* |
55 | * The ocfs2_locking_protocol defines the handlers called on ocfs2's behalf. | |
56 | */ | |
24ef1815 | 57 | struct ocfs2_locking_protocol { |
4670c46d | 58 | struct ocfs2_protocol_version lp_max_version; |
24ef1815 JB |
59 | void (*lp_lock_ast)(void *astarg); |
60 | void (*lp_blocking_ast)(void *astarg, int level); | |
7431cd7e | 61 | void (*lp_unlock_ast)(void *astarg, int error); |
24ef1815 JB |
62 | }; |
63 | ||
cf4d8d75 DT |
64 | |
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 | */ | |
70 | struct fsdlm_lksb_plus_lvb { | |
71 | struct dlm_lksb lksb; | |
72 | char lvb[DLM_LVB_LEN]; | |
73 | }; | |
74 | ||
e3dad42b JB |
75 | /* |
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 | */ | |
8f2c9c1b JB |
80 | union ocfs2_dlm_lksb { |
81 | struct dlm_lockstatus lksb_o2dlm; | |
cf4d8d75 DT |
82 | struct dlm_lksb lksb_fsdlm; |
83 | struct fsdlm_lksb_plus_lvb padding; | |
8f2c9c1b JB |
84 | }; |
85 | ||
e3dad42b JB |
86 | /* |
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 | */ | |
4670c46d JB |
91 | struct 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 | ||
e3dad42b JB |
101 | /* |
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 | */ | |
106 | struct 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. | |
286eaa95 | 136 | * |
2c39450b JB |
137 | * Once this call returns, the stack glue will be dropping this |
138 | * connection's reference on the module. | |
e3dad42b | 139 | */ |
2c39450b | 140 | int (*disconnect)(struct ocfs2_cluster_connection *conn); |
e3dad42b JB |
141 | |
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 | ||
286eaa95 JB |
196 | /* |
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 | */ | |
201 | struct 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 */ | |
9c6c877c JB |
214 | int ocfs2_cluster_connect(const char *stack_name, |
215 | const char *group, | |
4670c46d JB |
216 | int grouplen, |
217 | void (*recovery_handler)(int node_num, | |
218 | void *recovery_data), | |
219 | void *recovery_data, | |
220 | struct ocfs2_cluster_connection **conn); | |
286eaa95 JB |
221 | int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn, |
222 | int hangup_pending); | |
6953b4c0 | 223 | void ocfs2_cluster_hangup(const char *group, int grouplen); |
19fdb624 | 224 | int ocfs2_cluster_this_node(unsigned int *node); |
4670c46d | 225 | |
cf4d8d75 | 226 | struct ocfs2_lock_res; |
4670c46d | 227 | int ocfs2_dlm_lock(struct ocfs2_cluster_connection *conn, |
24ef1815 | 228 | int mode, |
8f2c9c1b | 229 | union ocfs2_dlm_lksb *lksb, |
24ef1815 JB |
230 | u32 flags, |
231 | void *name, | |
232 | unsigned int namelen, | |
cf4d8d75 | 233 | struct ocfs2_lock_res *astarg); |
4670c46d | 234 | int ocfs2_dlm_unlock(struct ocfs2_cluster_connection *conn, |
8f2c9c1b | 235 | union ocfs2_dlm_lksb *lksb, |
24ef1815 | 236 | u32 flags, |
cf4d8d75 | 237 | struct ocfs2_lock_res *astarg); |
24ef1815 | 238 | |
8f2c9c1b JB |
239 | int ocfs2_dlm_lock_status(union ocfs2_dlm_lksb *lksb); |
240 | void *ocfs2_dlm_lvb(union ocfs2_dlm_lksb *lksb); | |
cf0acdcd | 241 | void ocfs2_dlm_dump_lksb(union ocfs2_dlm_lksb *lksb); |
8f2c9c1b | 242 | |
63e0c48a | 243 | void ocfs2_stack_glue_set_locking_protocol(struct ocfs2_locking_protocol *proto); |
24ef1815 | 244 | |
286eaa95 JB |
245 | |
246 | /* Used by stack plugins */ | |
247 | int ocfs2_stack_glue_register(struct ocfs2_stack_plugin *plugin); | |
248 | void ocfs2_stack_glue_unregister(struct ocfs2_stack_plugin *plugin); | |
3878f110 | 249 | |
24ef1815 | 250 | #endif /* STACKGLUE_H */ |