1 /* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
6 * Glue to the underlying cluster stack.
8 * Copyright (C) 2007 Oracle. All rights reserved.
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.
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.
24 #include <linux/types.h>
25 #include <linux/list.h>
26 #include <linux/dlmconstants.h>
28 #include "dlm/dlmapi.h"
29 #include <linux/dlm.h>
31 /* Needed for plock-related prototypes */
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.
40 #define DLM_LKF_LOCAL 0x00100000
43 * This shadows DLM_LOCKSPACE_LEN in fs/dlm/dlm_internal.h. That probably
44 * wants to be in a public header.
46 #define GROUP_NAME_MAX 64
48 /* This shadows OCFS2_CLUSTER_NAME_LEN */
49 #define CLUSTER_NAME_MAX 16
53 * ocfs2_protocol_version changes when ocfs2 does something different in
54 * its inter-node behavior. See dlmglue.c for more information.
56 struct ocfs2_protocol_version {
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.
66 struct fsdlm_lksb_plus_lvb {
68 char lvb[DLM_LVB_LEN];
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
76 struct ocfs2_cluster_connection;
77 struct ocfs2_dlm_lksb {
79 struct dlm_lockstatus lksb_o2dlm;
80 struct dlm_lksb lksb_fsdlm;
81 struct fsdlm_lksb_plus_lvb padding;
83 struct ocfs2_cluster_connection *lksb_conn;
87 * The ocfs2_locking_protocol defines the handlers called on ocfs2's behalf.
89 struct 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);
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.
102 struct ocfs2_cluster_connection {
103 char cc_name[GROUP_NAME_MAX + 1];
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;
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.
120 struct ocfs2_stack_operations {
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
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
132 * ->connect() must not return until it is guaranteed that
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.
138 int (*connect)(struct ocfs2_cluster_connection *conn);
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.
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.
151 * Once this call returns, the stack glue will be dropping this
152 * connection's reference on the module.
154 int (*disconnect)(struct ocfs2_cluster_connection *conn);
157 * ->this_node() returns the cluster's unique identifier for the
160 int (*this_node)(unsigned int *node);
163 * Call the underlying dlm lock function. The ->dlm_lock()
164 * callback should convert the flags and mode as appropriate.
166 * ast and bast functions are not part of the call because the
167 * stack will likely want to wrap ast and bast calls before passing
168 * them to stack->sp_proto. There is no astarg. The lksb will
169 * be passed back to the ast and bast functions. The caller can
170 * use this to find their object.
172 int (*dlm_lock)(struct ocfs2_cluster_connection *conn,
174 struct ocfs2_dlm_lksb *lksb,
177 unsigned int namelen);
180 * Call the underlying dlm unlock function. The ->dlm_unlock()
181 * function should convert the flags as appropriate.
183 * The unlock ast is not passed, as the stack will want to wrap
184 * it before calling stack->sp_proto->lp_unlock_ast(). There is
185 * no astarg. The lksb will be passed back to the unlock ast
186 * function. The caller can use this to find their object.
188 int (*dlm_unlock)(struct ocfs2_cluster_connection *conn,
189 struct ocfs2_dlm_lksb *lksb,
193 * Return the status of the current lock status block. The fs
194 * code should never dereference the union. The ->lock_status()
195 * callback pulls out the stack-specific lksb, converts the status
196 * to a proper errno, and returns it.
198 int (*lock_status)(struct ocfs2_dlm_lksb *lksb);
201 * Return non-zero if the LVB is valid.
203 int (*lvb_valid)(struct ocfs2_dlm_lksb *lksb);
206 * Pull the lvb pointer off of the stack-specific lksb.
208 void *(*lock_lvb)(struct ocfs2_dlm_lksb *lksb);
211 * Cluster-aware posix locks
213 * This is NULL for stacks which do not support posix locks.
215 int (*plock)(struct ocfs2_cluster_connection *conn,
219 struct file_lock *fl);
222 * This is an optoinal debugging hook. If provided, the
223 * stack can dump debugging information about this lock.
225 void (*dump_lksb)(struct ocfs2_dlm_lksb *lksb);
229 * Each stack plugin must describe itself by registering a
230 * ocfs2_stack_plugin structure. This is only seen by stackglue and the
233 struct ocfs2_stack_plugin {
235 struct ocfs2_stack_operations *sp_ops;
236 struct module *sp_owner;
238 /* These are managed by the stackglue code. */
239 struct list_head sp_list;
240 unsigned int sp_count;
241 struct ocfs2_protocol_version sp_max_proto;
245 /* Used by the filesystem */
246 int ocfs2_cluster_connect(const char *stack_name,
247 const char *cluster_name,
248 int cluster_name_len,
251 struct ocfs2_locking_protocol *lproto,
252 void (*recovery_handler)(int node_num,
253 void *recovery_data),
255 struct ocfs2_cluster_connection **conn);
257 * Used by callers that don't store their stack name. They must ensure
258 * all nodes have the same stack.
260 int ocfs2_cluster_connect_agnostic(const char *group,
262 struct ocfs2_locking_protocol *lproto,
263 void (*recovery_handler)(int node_num,
264 void *recovery_data),
266 struct ocfs2_cluster_connection **conn);
267 int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn,
269 void ocfs2_cluster_hangup(const char *group, int grouplen);
270 int ocfs2_cluster_this_node(unsigned int *node);
272 struct ocfs2_lock_res;
273 int ocfs2_dlm_lock(struct ocfs2_cluster_connection *conn,
275 struct ocfs2_dlm_lksb *lksb,
278 unsigned int namelen);
279 int ocfs2_dlm_unlock(struct ocfs2_cluster_connection *conn,
280 struct ocfs2_dlm_lksb *lksb,
283 int ocfs2_dlm_lock_status(struct ocfs2_dlm_lksb *lksb);
284 int ocfs2_dlm_lvb_valid(struct ocfs2_dlm_lksb *lksb);
285 void *ocfs2_dlm_lvb(struct ocfs2_dlm_lksb *lksb);
286 void ocfs2_dlm_dump_lksb(struct ocfs2_dlm_lksb *lksb);
288 int ocfs2_stack_supports_plocks(void);
289 int ocfs2_plock(struct ocfs2_cluster_connection *conn, u64 ino,
290 struct file *file, int cmd, struct file_lock *fl);
292 void ocfs2_stack_glue_set_max_proto_version(struct ocfs2_protocol_version *max_proto);
295 /* Used by stack plugins */
296 int ocfs2_stack_glue_register(struct ocfs2_stack_plugin *plugin);
297 void ocfs2_stack_glue_unregister(struct ocfs2_stack_plugin *plugin);
299 #endif /* STACKGLUE_H */