Linux kernel mirror (for testing)
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1/*
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
4 *
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License version 2.
8 */
9
10#ifndef __LM_INTERFACE_DOT_H__
11#define __LM_INTERFACE_DOT_H__
12
13
14typedef void (*lm_callback_t) (void *ptr, unsigned int type, void *data);
15
16/*
17 * lm_mount() flags
18 *
19 * LM_MFLAG_SPECTATOR
20 * GFS is asking to join the filesystem's lockspace, but it doesn't want to
21 * modify the filesystem. The lock module shouldn't assign a journal to the FS
22 * mount. It shouldn't send recovery callbacks to the FS mount. If the node
23 * dies or withdraws, all locks can be wiped immediately.
24 */
25
26#define LM_MFLAG_SPECTATOR 0x00000001
27
28/*
29 * lm_lockstruct flags
30 *
31 * LM_LSFLAG_LOCAL
32 * The lock_nolock module returns LM_LSFLAG_LOCAL to GFS, indicating that GFS
33 * can make single-node optimizations.
34 */
35
36#define LM_LSFLAG_LOCAL 0x00000001
37
38/*
39 * lm_lockname types
40 */
41
42#define LM_TYPE_RESERVED 0x00
43#define LM_TYPE_NONDISK 0x01
44#define LM_TYPE_INODE 0x02
45#define LM_TYPE_RGRP 0x03
46#define LM_TYPE_META 0x04
47#define LM_TYPE_IOPEN 0x05
48#define LM_TYPE_FLOCK 0x06
49#define LM_TYPE_PLOCK 0x07
50#define LM_TYPE_QUOTA 0x08
51#define LM_TYPE_JOURNAL 0x09
52
53/*
54 * lm_lock() states
55 *
56 * SHARED is compatible with SHARED, not with DEFERRED or EX.
57 * DEFERRED is compatible with DEFERRED, not with SHARED or EX.
58 */
59
60#define LM_ST_UNLOCKED 0
61#define LM_ST_EXCLUSIVE 1
62#define LM_ST_DEFERRED 2
63#define LM_ST_SHARED 3
64
65/*
66 * lm_lock() flags
67 *
68 * LM_FLAG_TRY
69 * Don't wait to acquire the lock if it can't be granted immediately.
70 *
71 * LM_FLAG_TRY_1CB
72 * Send one blocking callback if TRY is set and the lock is not granted.
73 *
74 * LM_FLAG_NOEXP
75 * GFS sets this flag on lock requests it makes while doing journal recovery.
76 * These special requests should not be blocked due to the recovery like
77 * ordinary locks would be.
78 *
79 * LM_FLAG_ANY
80 * A SHARED request may also be granted in DEFERRED, or a DEFERRED request may
81 * also be granted in SHARED. The preferred state is whichever is compatible
82 * with other granted locks, or the specified state if no other locks exist.
83 *
84 * LM_FLAG_PRIORITY
85 * Override fairness considerations. Suppose a lock is held in a shared state
86 * and there is a pending request for the deferred state. A shared lock
87 * request with the priority flag would be allowed to bypass the deferred
88 * request and directly join the other shared lock. A shared lock request
89 * without the priority flag might be forced to wait until the deferred
90 * requested had acquired and released the lock.
91 */
92
93#define LM_FLAG_TRY 0x00000001
94#define LM_FLAG_TRY_1CB 0x00000002
95#define LM_FLAG_NOEXP 0x00000004
96#define LM_FLAG_ANY 0x00000008
97#define LM_FLAG_PRIORITY 0x00000010
98
99/*
100 * lm_lock() and lm_async_cb return flags
101 *
102 * LM_OUT_ST_MASK
103 * Masks the lower two bits of lock state in the returned value.
104 *
105 * LM_OUT_CACHEABLE
106 * The lock hasn't been released so GFS can continue to cache data for it.
107 *
108 * LM_OUT_CANCELED
109 * The lock request was canceled.
110 *
111 * LM_OUT_ASYNC
112 * The result of the request will be returned in an LM_CB_ASYNC callback.
113 */
114
115#define LM_OUT_ST_MASK 0x00000003
116#define LM_OUT_CACHEABLE 0x00000004
117#define LM_OUT_CANCELED 0x00000008
118#define LM_OUT_ASYNC 0x00000080
119#define LM_OUT_ERROR 0x00000100
120
121/*
122 * lm_callback_t types
123 *
124 * LM_CB_NEED_E LM_CB_NEED_D LM_CB_NEED_S
125 * Blocking callback, a remote node is requesting the given lock in
126 * EXCLUSIVE, DEFERRED, or SHARED.
127 *
128 * LM_CB_NEED_RECOVERY
129 * The given journal needs to be recovered.
130 *
131 * LM_CB_DROPLOCKS
132 * Reduce the number of cached locks.
133 *
134 * LM_CB_ASYNC
135 * The given lock has been granted.
136 */
137
138#define LM_CB_NEED_E 257
139#define LM_CB_NEED_D 258
140#define LM_CB_NEED_S 259
141#define LM_CB_NEED_RECOVERY 260
142#define LM_CB_DROPLOCKS 261
143#define LM_CB_ASYNC 262
144
145/*
146 * lm_recovery_done() messages
147 */
148
149#define LM_RD_GAVEUP 308
150#define LM_RD_SUCCESS 309
151
152
153struct lm_lockname {
154 u64 ln_number;
155 unsigned int ln_type;
156};
157
158#define lm_name_equal(name1, name2) \
159 (((name1)->ln_number == (name2)->ln_number) && \
160 ((name1)->ln_type == (name2)->ln_type)) \
161
162struct lm_async_cb {
163 struct lm_lockname lc_name;
164 int lc_ret;
165};
166
167struct lm_lockstruct;
168
169struct lm_lockops {
170 const char *lm_proto_name;
171
172 /*
173 * Mount/Unmount
174 */
175
176 int (*lm_mount) (char *table_name, char *host_data,
177 lm_callback_t cb, void *cb_data,
178 unsigned int min_lvb_size, int flags,
179 struct lm_lockstruct *lockstruct,
180 struct kobject *fskobj);
181
182 void (*lm_others_may_mount) (void *lockspace);
183
184 void (*lm_unmount) (void *lockspace);
185
186 void (*lm_withdraw) (void *lockspace);
187
188 /*
189 * Lock oriented operations
190 */
191
192 int (*lm_get_lock) (void *lockspace, struct lm_lockname *name, void **lockp);
193
194 void (*lm_put_lock) (void *lock);
195
196 unsigned int (*lm_lock) (void *lock, unsigned int cur_state,
197 unsigned int req_state, unsigned int flags);
198
199 unsigned int (*lm_unlock) (void *lock, unsigned int cur_state);
200
201 void (*lm_cancel) (void *lock);
202
203 int (*lm_hold_lvb) (void *lock, char **lvbp);
204 void (*lm_unhold_lvb) (void *lock, char *lvb);
205
206 /*
207 * Posix Lock oriented operations
208 */
209
210 int (*lm_plock_get) (void *lockspace, struct lm_lockname *name,
211 struct file *file, struct file_lock *fl);
212
213 int (*lm_plock) (void *lockspace, struct lm_lockname *name,
214 struct file *file, int cmd, struct file_lock *fl);
215
216 int (*lm_punlock) (void *lockspace, struct lm_lockname *name,
217 struct file *file, struct file_lock *fl);
218
219 /*
220 * Client oriented operations
221 */
222
223 void (*lm_recovery_done) (void *lockspace, unsigned int jid,
224 unsigned int message);
225
226 struct module *lm_owner;
227};
228
229/*
230 * lm_mount() return values
231 *
232 * ls_jid - the journal ID this node should use
233 * ls_first - this node is the first to mount the file system
234 * ls_lvb_size - size in bytes of lock value blocks
235 * ls_lockspace - lock module's context for this file system
236 * ls_ops - lock module's functions
237 * ls_flags - lock module features
238 */
239
240struct lm_lockstruct {
241 unsigned int ls_jid;
242 unsigned int ls_first;
243 unsigned int ls_lvb_size;
244 void *ls_lockspace;
245 const struct lm_lockops *ls_ops;
246 int ls_flags;
247};
248
249/*
250 * Lock module bottom interface. A lock module makes itself available to GFS
251 * with these functions.
252 */
253
254int gfs2_register_lockproto(const struct lm_lockops *proto);
255void gfs2_unregister_lockproto(const struct lm_lockops *proto);
256
257/*
258 * Lock module top interface. GFS calls these functions when mounting or
259 * unmounting a file system.
260 */
261
262int gfs2_mount_lockproto(char *proto_name, char *table_name, char *host_data,
263 lm_callback_t cb, void *cb_data,
264 unsigned int min_lvb_size, int flags,
265 struct lm_lockstruct *lockstruct,
266 struct kobject *fskobj);
267
268void gfs2_unmount_lockproto(struct lm_lockstruct *lockstruct);
269
270void gfs2_withdraw_lockproto(struct lm_lockstruct *lockstruct);
271
272#endif /* __LM_INTERFACE_DOT_H__ */
273