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50acfb2b | 1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
24ef1815 JB |
2 | /* -*- mode: c; c-basic-offset: 8; -*- |
3 | * vim: noexpandtab sw=8 ts=8 sts=0: | |
4 | * | |
5 | * stackglue.h | |
6 | * | |
7 | * Glue to the underlying cluster stack. | |
8 | * | |
9 | * Copyright (C) 2007 Oracle. All rights reserved. | |
24ef1815 JB |
10 | */ |
11 | ||
12 | ||
13 | #ifndef STACKGLUE_H | |
14 | #define STACKGLUE_H | |
15 | ||
bd3e7610 JB |
16 | #include <linux/types.h> |
17 | #include <linux/list.h> | |
18 | #include <linux/dlmconstants.h> | |
19 | ||
e3dad42b | 20 | #include "dlm/dlmapi.h" |
cf4d8d75 | 21 | #include <linux/dlm.h> |
e3dad42b | 22 | |
53da4939 MF |
23 | /* Needed for plock-related prototypes */ |
24 | struct file; | |
25 | struct file_lock; | |
26 | ||
bd3e7610 JB |
27 | /* |
28 | * dlmconstants.h does not have a LOCAL flag. We hope to remove it | |
29 | * some day, but right now we need it. Let's fake it. This value is larger | |
30 | * than any flag in dlmconstants.h. | |
31 | */ | |
32 | #define DLM_LKF_LOCAL 0x00100000 | |
33 | ||
4670c46d JB |
34 | /* |
35 | * This shadows DLM_LOCKSPACE_LEN in fs/dlm/dlm_internal.h. That probably | |
36 | * wants to be in a public header. | |
37 | */ | |
38 | #define GROUP_NAME_MAX 64 | |
39 | ||
c74a3bdd GR |
40 | /* This shadows OCFS2_CLUSTER_NAME_LEN */ |
41 | #define CLUSTER_NAME_MAX 16 | |
42 | ||
4670c46d | 43 | |
e3dad42b JB |
44 | /* |
45 | * ocfs2_protocol_version changes when ocfs2 does something different in | |
46 | * its inter-node behavior. See dlmglue.c for more information. | |
47 | */ | |
4670c46d JB |
48 | struct ocfs2_protocol_version { |
49 | u8 pv_major; | |
50 | u8 pv_minor; | |
51 | }; | |
52 | ||
cf4d8d75 DT |
53 | /* |
54 | * The dlm_lockstatus struct includes lvb space, but the dlm_lksb struct only | |
55 | * has a pointer to separately allocated lvb space. This struct exists only to | |
56 | * include in the lksb union to make space for a combined dlm_lksb and lvb. | |
57 | */ | |
58 | struct fsdlm_lksb_plus_lvb { | |
59 | struct dlm_lksb lksb; | |
60 | char lvb[DLM_LVB_LEN]; | |
61 | }; | |
62 | ||
e3dad42b JB |
63 | /* |
64 | * A union of all lock status structures. We define it here so that the | |
65 | * size of the union is known. Lock status structures are embedded in | |
66 | * ocfs2 inodes. | |
67 | */ | |
c0e41338 JB |
68 | struct ocfs2_cluster_connection; |
69 | struct ocfs2_dlm_lksb { | |
70 | union { | |
71 | struct dlm_lockstatus lksb_o2dlm; | |
72 | struct dlm_lksb lksb_fsdlm; | |
73 | struct fsdlm_lksb_plus_lvb padding; | |
74 | }; | |
75 | struct ocfs2_cluster_connection *lksb_conn; | |
8f2c9c1b JB |
76 | }; |
77 | ||
a796d286 JB |
78 | /* |
79 | * The ocfs2_locking_protocol defines the handlers called on ocfs2's behalf. | |
80 | */ | |
81 | struct ocfs2_locking_protocol { | |
82 | struct ocfs2_protocol_version lp_max_version; | |
c0e41338 JB |
83 | void (*lp_lock_ast)(struct ocfs2_dlm_lksb *lksb); |
84 | void (*lp_blocking_ast)(struct ocfs2_dlm_lksb *lksb, int level); | |
85 | void (*lp_unlock_ast)(struct ocfs2_dlm_lksb *lksb, int error); | |
a796d286 JB |
86 | }; |
87 | ||
88 | ||
e3dad42b JB |
89 | /* |
90 | * A cluster connection. Mostly opaque to ocfs2, the connection holds | |
91 | * state for the underlying stack. ocfs2 does use cc_version to determine | |
92 | * locking compatibility. | |
93 | */ | |
4670c46d | 94 | struct ocfs2_cluster_connection { |
c74a3bdd | 95 | char cc_name[GROUP_NAME_MAX + 1]; |
4670c46d | 96 | int cc_namelen; |
c74a3bdd GR |
97 | char cc_cluster_name[CLUSTER_NAME_MAX + 1]; |
98 | int cc_cluster_name_len; | |
4670c46d | 99 | struct ocfs2_protocol_version cc_version; |
110946c8 | 100 | struct ocfs2_locking_protocol *cc_proto; |
4670c46d JB |
101 | void (*cc_recovery_handler)(int node_num, void *recovery_data); |
102 | void *cc_recovery_data; | |
103 | void *cc_lockspace; | |
104 | void *cc_private; | |
105 | }; | |
106 | ||
e3dad42b JB |
107 | /* |
108 | * Each cluster stack implements the stack operations structure. Not used | |
109 | * in the ocfs2 code, the stackglue code translates generic cluster calls | |
110 | * into stack operations. | |
111 | */ | |
112 | struct ocfs2_stack_operations { | |
113 | /* | |
114 | * The fs code calls ocfs2_cluster_connect() to attach a new | |
115 | * filesystem to the cluster stack. The ->connect() op is passed | |
116 | * an ocfs2_cluster_connection with the name and recovery field | |
117 | * filled in. | |
118 | * | |
119 | * The stack must set up any notification mechanisms and create | |
120 | * the filesystem lockspace in the DLM. The lockspace should be | |
121 | * stored on cc_lockspace. Any other information can be stored on | |
122 | * cc_private. | |
123 | * | |
124 | * ->connect() must not return until it is guaranteed that | |
125 | * | |
25985edc | 126 | * - Node down notifications for the filesystem will be received |
e3dad42b JB |
127 | * and passed to conn->cc_recovery_handler(). |
128 | * - Locking requests for the filesystem will be processed. | |
129 | */ | |
130 | int (*connect)(struct ocfs2_cluster_connection *conn); | |
131 | ||
132 | /* | |
133 | * The fs code calls ocfs2_cluster_disconnect() when a filesystem | |
134 | * no longer needs cluster services. All DLM locks have been | |
135 | * dropped, and recovery notification is being ignored by the | |
136 | * fs code. The stack must disengage from the DLM and discontinue | |
137 | * recovery notification. | |
138 | * | |
139 | * Once ->disconnect() has returned, the connection structure will | |
140 | * be freed. Thus, a stack must not return from ->disconnect() | |
141 | * until it will no longer reference the conn pointer. | |
286eaa95 | 142 | * |
2c39450b JB |
143 | * Once this call returns, the stack glue will be dropping this |
144 | * connection's reference on the module. | |
e3dad42b | 145 | */ |
2c39450b | 146 | int (*disconnect)(struct ocfs2_cluster_connection *conn); |
e3dad42b JB |
147 | |
148 | /* | |
149 | * ->this_node() returns the cluster's unique identifier for the | |
150 | * local node. | |
151 | */ | |
3e834151 GR |
152 | int (*this_node)(struct ocfs2_cluster_connection *conn, |
153 | unsigned int *node); | |
e3dad42b JB |
154 | |
155 | /* | |
156 | * Call the underlying dlm lock function. The ->dlm_lock() | |
157 | * callback should convert the flags and mode as appropriate. | |
158 | * | |
159 | * ast and bast functions are not part of the call because the | |
160 | * stack will likely want to wrap ast and bast calls before passing | |
a796d286 JB |
161 | * them to stack->sp_proto. There is no astarg. The lksb will |
162 | * be passed back to the ast and bast functions. The caller can | |
163 | * use this to find their object. | |
e3dad42b JB |
164 | */ |
165 | int (*dlm_lock)(struct ocfs2_cluster_connection *conn, | |
166 | int mode, | |
c0e41338 | 167 | struct ocfs2_dlm_lksb *lksb, |
e3dad42b JB |
168 | u32 flags, |
169 | void *name, | |
a796d286 | 170 | unsigned int namelen); |
e3dad42b JB |
171 | |
172 | /* | |
173 | * Call the underlying dlm unlock function. The ->dlm_unlock() | |
174 | * function should convert the flags as appropriate. | |
175 | * | |
176 | * The unlock ast is not passed, as the stack will want to wrap | |
a796d286 JB |
177 | * it before calling stack->sp_proto->lp_unlock_ast(). There is |
178 | * no astarg. The lksb will be passed back to the unlock ast | |
179 | * function. The caller can use this to find their object. | |
e3dad42b JB |
180 | */ |
181 | int (*dlm_unlock)(struct ocfs2_cluster_connection *conn, | |
c0e41338 | 182 | struct ocfs2_dlm_lksb *lksb, |
a796d286 | 183 | u32 flags); |
e3dad42b JB |
184 | |
185 | /* | |
186 | * Return the status of the current lock status block. The fs | |
187 | * code should never dereference the union. The ->lock_status() | |
188 | * callback pulls out the stack-specific lksb, converts the status | |
189 | * to a proper errno, and returns it. | |
190 | */ | |
c0e41338 | 191 | int (*lock_status)(struct ocfs2_dlm_lksb *lksb); |
e3dad42b | 192 | |
1c520dfb JB |
193 | /* |
194 | * Return non-zero if the LVB is valid. | |
195 | */ | |
c0e41338 | 196 | int (*lvb_valid)(struct ocfs2_dlm_lksb *lksb); |
1c520dfb | 197 | |
e3dad42b JB |
198 | /* |
199 | * Pull the lvb pointer off of the stack-specific lksb. | |
200 | */ | |
c0e41338 | 201 | void *(*lock_lvb)(struct ocfs2_dlm_lksb *lksb); |
e3dad42b | 202 | |
53da4939 MF |
203 | /* |
204 | * Cluster-aware posix locks | |
205 | * | |
206 | * This is NULL for stacks which do not support posix locks. | |
207 | */ | |
208 | int (*plock)(struct ocfs2_cluster_connection *conn, | |
209 | u64 ino, | |
210 | struct file *file, | |
211 | int cmd, | |
212 | struct file_lock *fl); | |
213 | ||
e3dad42b JB |
214 | /* |
215 | * This is an optoinal debugging hook. If provided, the | |
216 | * stack can dump debugging information about this lock. | |
217 | */ | |
c0e41338 | 218 | void (*dump_lksb)(struct ocfs2_dlm_lksb *lksb); |
e3dad42b JB |
219 | }; |
220 | ||
286eaa95 JB |
221 | /* |
222 | * Each stack plugin must describe itself by registering a | |
223 | * ocfs2_stack_plugin structure. This is only seen by stackglue and the | |
224 | * stack driver. | |
225 | */ | |
226 | struct ocfs2_stack_plugin { | |
227 | char *sp_name; | |
228 | struct ocfs2_stack_operations *sp_ops; | |
229 | struct module *sp_owner; | |
230 | ||
231 | /* These are managed by the stackglue code. */ | |
232 | struct list_head sp_list; | |
233 | unsigned int sp_count; | |
e603cfb0 | 234 | struct ocfs2_protocol_version sp_max_proto; |
286eaa95 JB |
235 | }; |
236 | ||
237 | ||
238 | /* Used by the filesystem */ | |
9c6c877c | 239 | int ocfs2_cluster_connect(const char *stack_name, |
c74a3bdd GR |
240 | const char *cluster_name, |
241 | int cluster_name_len, | |
9c6c877c | 242 | const char *group, |
4670c46d | 243 | int grouplen, |
553b5eb9 | 244 | struct ocfs2_locking_protocol *lproto, |
4670c46d JB |
245 | void (*recovery_handler)(int node_num, |
246 | void *recovery_data), | |
247 | void *recovery_data, | |
248 | struct ocfs2_cluster_connection **conn); | |
cbe0e331 JB |
249 | /* |
250 | * Used by callers that don't store their stack name. They must ensure | |
251 | * all nodes have the same stack. | |
252 | */ | |
253 | int 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); | |
286eaa95 JB |
260 | int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn, |
261 | int hangup_pending); | |
6953b4c0 | 262 | void ocfs2_cluster_hangup(const char *group, int grouplen); |
3e834151 GR |
263 | int ocfs2_cluster_this_node(struct ocfs2_cluster_connection *conn, |
264 | unsigned int *node); | |
4670c46d | 265 | |
cf4d8d75 | 266 | struct ocfs2_lock_res; |
4670c46d | 267 | int ocfs2_dlm_lock(struct ocfs2_cluster_connection *conn, |
24ef1815 | 268 | int mode, |
c0e41338 | 269 | struct ocfs2_dlm_lksb *lksb, |
24ef1815 JB |
270 | u32 flags, |
271 | void *name, | |
a796d286 | 272 | unsigned int namelen); |
4670c46d | 273 | int ocfs2_dlm_unlock(struct ocfs2_cluster_connection *conn, |
c0e41338 | 274 | struct ocfs2_dlm_lksb *lksb, |
a796d286 | 275 | u32 flags); |
24ef1815 | 276 | |
c0e41338 JB |
277 | int ocfs2_dlm_lock_status(struct ocfs2_dlm_lksb *lksb); |
278 | int ocfs2_dlm_lvb_valid(struct ocfs2_dlm_lksb *lksb); | |
279 | void *ocfs2_dlm_lvb(struct ocfs2_dlm_lksb *lksb); | |
280 | void ocfs2_dlm_dump_lksb(struct ocfs2_dlm_lksb *lksb); | |
8f2c9c1b | 281 | |
53da4939 MF |
282 | int ocfs2_stack_supports_plocks(void); |
283 | int ocfs2_plock(struct ocfs2_cluster_connection *conn, u64 ino, | |
284 | struct file *file, int cmd, struct file_lock *fl); | |
285 | ||
553b5eb9 | 286 | void ocfs2_stack_glue_set_max_proto_version(struct ocfs2_protocol_version *max_proto); |
24ef1815 | 287 | |
286eaa95 JB |
288 | |
289 | /* Used by stack plugins */ | |
290 | int ocfs2_stack_glue_register(struct ocfs2_stack_plugin *plugin); | |
291 | void ocfs2_stack_glue_unregister(struct ocfs2_stack_plugin *plugin); | |
3878f110 | 292 | |
9dde5e4f GH |
293 | extern struct kset *ocfs2_kset; |
294 | ||
24ef1815 | 295 | #endif /* STACKGLUE_H */ |