[linux.git] / fs / gfs2 / lm_interface.h

/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
 *
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU General Public License v.2.
 */

#ifndef __LM_INTERFACE_DOT_H__
#define __LM_INTERFACE_DOT_H__

/*
 * Opaque handles represent the lock module's lockspace structure, the lock
 * module's lock structures, and GFS's file system (superblock) structure.
 */

typedef void lm_lockspace_t;
typedef void lm_lock_t;
typedef void lm_fsdata_t;

typedef void (*lm_callback_t) (lm_fsdata_t *fsdata, unsigned int type,
			       void *data);

/*
 * lm_mount() flags
 *
 * LM_MFLAG_SPECTATOR
 * GFS is asking to join the filesystem's lockspace, but it doesn't want to
 * modify the filesystem.  The lock module shouldn't assign a journal to the FS
 * mount.  It shouldn't send recovery callbacks to the FS mount.  If the node
 * dies or withdraws, all locks can be wiped immediately.
 */

#define LM_MFLAG_SPECTATOR	0x00000001

/*
 * lm_lockstruct flags
 *
 * LM_LSFLAG_LOCAL
 * The lock_nolock module returns LM_LSFLAG_LOCAL to GFS, indicating that GFS
 * can make single-node optimizations.
 */

#define LM_LSFLAG_LOCAL		0x00000001

/*
 * lm_lockname types
 */

#define LM_TYPE_RESERVED	0x00
#define LM_TYPE_NONDISK		0x01
#define LM_TYPE_INODE		0x02
#define LM_TYPE_RGRP		0x03
#define LM_TYPE_META		0x04
#define LM_TYPE_IOPEN		0x05
#define LM_TYPE_FLOCK		0x06
#define LM_TYPE_PLOCK		0x07
#define LM_TYPE_QUOTA		0x08
#define LM_TYPE_JOURNAL		0x09

/*
 * lm_lock() states
 *
 * SHARED is compatible with SHARED, not with DEFERRED or EX.
 * DEFERRED is compatible with DEFERRED, not with SHARED or EX.
 */

#define LM_ST_UNLOCKED		0
#define LM_ST_EXCLUSIVE		1
#define LM_ST_DEFERRED		2
#define LM_ST_SHARED		3

/*
 * lm_lock() flags
 *
 * LM_FLAG_TRY
 * Don't wait to acquire the lock if it can't be granted immediately.
 *
 * LM_FLAG_TRY_1CB
 * Send one blocking callback if TRY is set and the lock is not granted.
 *
 * LM_FLAG_NOEXP
 * GFS sets this flag on lock requests it makes while doing journal recovery.
 * These special requests should not be blocked due to the recovery like
 * ordinary locks would be.
 *
 * LM_FLAG_ANY
 * A SHARED request may also be granted in DEFERRED, or a DEFERRED request may
 * also be granted in SHARED.  The preferred state is whichever is compatible
 * with other granted locks, or the specified state if no other locks exist.
 *
 * LM_FLAG_PRIORITY
 * Override fairness considerations.  Suppose a lock is held in a shared state
 * and there is a pending request for the deferred state.  A shared lock
 * request with the priority flag would be allowed to bypass the deferred
 * request and directly join the other shared lock.  A shared lock request
 * without the priority flag might be forced to wait until the deferred
 * requested had acquired and released the lock.
 */

#define LM_FLAG_TRY		0x00000001
#define LM_FLAG_TRY_1CB		0x00000002
#define LM_FLAG_NOEXP		0x00000004
#define LM_FLAG_ANY		0x00000008
#define LM_FLAG_PRIORITY	0x00000010

/*
 * lm_lock() and lm_async_cb return flags
 *
 * LM_OUT_ST_MASK
 * Masks the lower two bits of lock state in the returned value.
 *
 * LM_OUT_CACHEABLE
 * The lock hasn't been released so GFS can continue to cache data for it.
 *
 * LM_OUT_CANCELED
 * The lock request was canceled.
 *
 * LM_OUT_ASYNC
 * The result of the request will be returned in an LM_CB_ASYNC callback.
 */

#define LM_OUT_ST_MASK		0x00000003
#define LM_OUT_CACHEABLE	0x00000004
#define LM_OUT_CANCELED		0x00000008
#define LM_OUT_ASYNC		0x00000080
#define LM_OUT_ERROR		0x00000100

/*
 * lm_callback_t types
 *
 * LM_CB_NEED_E LM_CB_NEED_D LM_CB_NEED_S
 * Blocking callback, a remote node is requesting the given lock in
 * EXCLUSIVE, DEFERRED, or SHARED.
 *
 * LM_CB_NEED_RECOVERY
 * The given journal needs to be recovered.
 *
 * LM_CB_DROPLOCKS
 * Reduce the number of cached locks.
 *
 * LM_CB_ASYNC
 * The given lock has been granted.
 */

#define LM_CB_NEED_E		257
#define LM_CB_NEED_D		258
#define LM_CB_NEED_S		259
#define LM_CB_NEED_RECOVERY	260
#define LM_CB_DROPLOCKS		261
#define LM_CB_ASYNC		262

/*
 * lm_recovery_done() messages
 */

#define LM_RD_GAVEUP		308
#define LM_RD_SUCCESS		309


struct lm_lockname {
	uint64_t ln_number;
	unsigned int ln_type;
};

#define lm_name_equal(name1, name2) \
	(((name1)->ln_number == (name2)->ln_number) && \
	 ((name1)->ln_type == (name2)->ln_type)) \

struct lm_async_cb {
	struct lm_lockname lc_name;
	int lc_ret;
};

struct lm_lockstruct;

struct lm_lockops {
	char lm_proto_name[256];

	/*
	 * Mount/Unmount
	 */

	int (*lm_mount) (char *table_name, char *host_data,
			 lm_callback_t cb, lm_fsdata_t *fsdata,
			 unsigned int min_lvb_size, int flags,
			 struct lm_lockstruct *lockstruct,
			 struct kobject *fskobj);

	void (*lm_others_may_mount) (lm_lockspace_t *lockspace);

	void (*lm_unmount) (lm_lockspace_t *lockspace);

	void (*lm_withdraw) (lm_lockspace_t *lockspace);

	/*
	 * Lock oriented operations
	 */

	int (*lm_get_lock) (lm_lockspace_t *lockspace,
			    struct lm_lockname *name, lm_lock_t **lockp);

	void (*lm_put_lock) (lm_lock_t *lock);

	unsigned int (*lm_lock) (lm_lock_t *lock, unsigned int cur_state,
				 unsigned int req_state, unsigned int flags);

	unsigned int (*lm_unlock) (lm_lock_t *lock, unsigned int cur_state);

	void (*lm_cancel) (lm_lock_t *lock);

	int (*lm_hold_lvb) (lm_lock_t *lock, char **lvbp);
	void (*lm_unhold_lvb) (lm_lock_t *lock, char *lvb);
	void (*lm_sync_lvb) (lm_lock_t *lock, char *lvb);

	/*
	 * Posix Lock oriented operations
	 */

	int (*lm_plock_get) (lm_lockspace_t *lockspace,
			     struct lm_lockname *name,
			     struct file *file, struct file_lock *fl);

	int (*lm_plock) (lm_lockspace_t *lockspace,
			 struct lm_lockname *name,
			 struct file *file, int cmd, struct file_lock *fl);

	int (*lm_punlock) (lm_lockspace_t *lockspace,
			   struct lm_lockname *name,
			   struct file *file, struct file_lock *fl);

	/*
	 * Client oriented operations
	 */

	void (*lm_recovery_done) (lm_lockspace_t *lockspace, unsigned int jid,
				  unsigned int message);

	struct module *lm_owner;
};

/*
 * lm_mount() return values
 *
 * ls_jid - the journal ID this node should use
 * ls_first - this node is the first to mount the file system
 * ls_lvb_size - size in bytes of lock value blocks
 * ls_lockspace - lock module's context for this file system
 * ls_ops - lock module's functions
 * ls_flags - lock module features
 */

struct lm_lockstruct {
	unsigned int ls_jid;
	unsigned int ls_first;
	unsigned int ls_lvb_size;
	lm_lockspace_t *ls_lockspace;
	struct lm_lockops *ls_ops;
	int ls_flags;
};

void __init gfs2_init_lmh(void);

/*
 * Lock module bottom interface.  A lock module makes itself available to GFS
 * with these functions.
 */

int gfs2_register_lockproto(struct lm_lockops *proto);

void gfs2_unregister_lockproto(struct lm_lockops *proto);

/*
 * Lock module top interface.  GFS calls these functions when mounting or
 * unmounting a file system.
 */

int gfs2_mount_lockproto(char *proto_name, char *table_name, char *host_data,
			 lm_callback_t cb, lm_fsdata_t *fsdata,
			 unsigned int min_lvb_size, int flags,
			 struct lm_lockstruct *lockstruct,
			 struct kobject *fskobj);

void gfs2_unmount_lockproto(struct lm_lockstruct *lockstruct);

void gfs2_withdraw_lockproto(struct lm_lockstruct *lockstruct);

#endif /* __LM_INTERFACE_DOT_H__ */
Commit	Line	Data
b3b94faa DT	1	/*
b3b94faa DT	2	* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3a8a9a10	3	* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
b3b94faa DT	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 v.2.
	8	*/
	9
	10	#ifndef __LM_INTERFACE_DOT_H__
	11	#define __LM_INTERFACE_DOT_H__
	12
	13	/*
	14	* Opaque handles represent the lock module's lockspace structure, the lock
	15	* module's lock structures, and GFS's file system (superblock) structure.
	16	*/
	17
	18	typedef void lm_lockspace_t;
	19	typedef void lm_lock_t;
	20	typedef void lm_fsdata_t;
	21
	22	typedef void (lm_callback_t) (lm_fsdata_t fsdata, unsigned int type,
	23	void *data);
	24
	25	/*
	26	* lm_mount() flags
	27	*
	28	* LM_MFLAG_SPECTATOR
	29	* GFS is asking to join the filesystem's lockspace, but it doesn't want to
	30	* modify the filesystem. The lock module shouldn't assign a journal to the FS
	31	* mount. It shouldn't send recovery callbacks to the FS mount. If the node
	32	* dies or withdraws, all locks can be wiped immediately.
	33	*/
	34
	35	#define LM_MFLAG_SPECTATOR 0x00000001
	36
	37	/*
	38	* lm_lockstruct flags
	39	*
	40	* LM_LSFLAG_LOCAL
	41	* The lock_nolock module returns LM_LSFLAG_LOCAL to GFS, indicating that GFS
	42	* can make single-node optimizations.
	43	*/
	44
	45	#define LM_LSFLAG_LOCAL 0x00000001
	46
	47	/*
	48	* lm_lockname types
	49	*/
	50
	51	#define LM_TYPE_RESERVED 0x00
	52	#define LM_TYPE_NONDISK 0x01
	53	#define LM_TYPE_INODE 0x02
	54	#define LM_TYPE_RGRP 0x03
	55	#define LM_TYPE_META 0x04
	56	#define LM_TYPE_IOPEN 0x05
	57	#define LM_TYPE_FLOCK 0x06
	58	#define LM_TYPE_PLOCK 0x07
	59	#define LM_TYPE_QUOTA 0x08
	60	#define LM_TYPE_JOURNAL 0x09
	61
	62	/*
	63	* lm_lock() states
	64	*
	65	* SHARED is compatible with SHARED, not with DEFERRED or EX.
	66	* DEFERRED is compatible with DEFERRED, not with SHARED or EX.
	67	*/
68
69	#define LM_ST_UNLOCKED 0
70	#define LM_ST_EXCLUSIVE 1
71	#define LM_ST_DEFERRED 2
72	#define LM_ST_SHARED 3
73
74	/*
75	* lm_lock() flags
76	*
77	* LM_FLAG_TRY
78	* Don't wait to acquire the lock if it can't be granted immediately.
79	*
80	* LM_FLAG_TRY_1CB
81	* Send one blocking callback if TRY is set and the lock is not granted.
82	*
83	* LM_FLAG_NOEXP
84	* GFS sets this flag on lock requests it makes while doing journal recovery.
85	* These special requests should not be blocked due to the recovery like
86	* ordinary locks would be.
87	*
88	* LM_FLAG_ANY
89	* A SHARED request may also be granted in DEFERRED, or a DEFERRED request may
90	* also be granted in SHARED. The preferred state is whichever is compatible
91	* with other granted locks, or the specified state if no other locks exist.
92	*
93	* LM_FLAG_PRIORITY
94	* Override fairness considerations. Suppose a lock is held in a shared state
95	* and there is a pending request for the deferred state. A shared lock
96	* request with the priority flag would be allowed to bypass the deferred
97	* request and directly join the other shared lock. A shared lock request
98	* without the priority flag might be forced to wait until the deferred
99	* requested had acquired and released the lock.
100	*/
101
102	#define LM_FLAG_TRY 0x00000001
103	#define LM_FLAG_TRY_1CB 0x00000002
104	#define LM_FLAG_NOEXP 0x00000004
105	#define LM_FLAG_ANY 0x00000008
106	#define LM_FLAG_PRIORITY 0x00000010
107
108	/*
109	* lm_lock() and lm_async_cb return flags
110	*
111	* LM_OUT_ST_MASK
112	* Masks the lower two bits of lock state in the returned value.
113	*
114	* LM_OUT_CACHEABLE
115	* The lock hasn't been released so GFS can continue to cache data for it.
116	*
117	* LM_OUT_CANCELED
118	* The lock request was canceled.
119	*
120	* LM_OUT_ASYNC
121	* The result of the request will be returned in an LM_CB_ASYNC callback.
122	*/
123
124	#define LM_OUT_ST_MASK 0x00000003
125	#define LM_OUT_CACHEABLE 0x00000004
126	#define LM_OUT_CANCELED 0x00000008
127	#define LM_OUT_ASYNC 0x00000080
128	#define LM_OUT_ERROR 0x00000100
129
130	/*
131	* lm_callback_t types
132	*
133	* LM_CB_NEED_E LM_CB_NEED_D LM_CB_NEED_S
134	* Blocking callback, a remote node is requesting the given lock in
135	* EXCLUSIVE, DEFERRED, or SHARED.
136	*
137	* LM_CB_NEED_RECOVERY
138	* The given journal needs to be recovered.
139	*
140	* LM_CB_DROPLOCKS
141	* Reduce the number of cached locks.
142	*
143	* LM_CB_ASYNC
144	* The given lock has been granted.
145	*/
146
147	#define LM_CB_NEED_E 257
148	#define LM_CB_NEED_D 258
149	#define LM_CB_NEED_S 259
150	#define LM_CB_NEED_RECOVERY 260
151	#define LM_CB_DROPLOCKS 261
152	#define LM_CB_ASYNC 262
153
154	/*
155	* lm_recovery_done() messages
156	*/
157
158	#define LM_RD_GAVEUP 308
159	#define LM_RD_SUCCESS 309
160
161
162	struct lm_lockname {
163	uint64_t ln_number;
164	unsigned int ln_type;
165	};
166
167	#define lm_name_equal(name1, name2) \
168	(((name1)->ln_number == (name2)->ln_number) && \
169	((name1)->ln_type == (name2)->ln_type)) \
170
171	struct lm_async_cb {
172	struct lm_lockname lc_name;
173	int lc_ret;
174	};
175
176	struct lm_lockstruct;
177
178	struct lm_lockops {
179	char lm_proto_name[256];
180
181	/*
182	* Mount/Unmount
183	*/
184
185	int (lm_mount) (char table_name, char *host_data,
186	lm_callback_t cb, lm_fsdata_t *fsdata,
187	unsigned int min_lvb_size, int flags,
188	struct lm_lockstruct *lockstruct,
189	struct kobject *fskobj);
190
191	void (lm_others_may_mount) (lm_lockspace_t lockspace);
192
193	void (lm_unmount) (lm_lockspace_t lockspace);
194
195	void (lm_withdraw) (lm_lockspace_t lockspace);
196
197	/*
198	* Lock oriented operations
199	*/
200
201	int (lm_get_lock) (lm_lockspace_t lockspace,
202	struct lm_lockname name, lm_lock_t *lockp);
203
204	void (lm_put_lock) (lm_lock_t lock);
205
206	unsigned int (lm_lock) (lm_lock_t lock, unsigned int cur_state,
207	unsigned int req_state, unsigned int flags);
208
209	unsigned int (lm_unlock) (lm_lock_t lock, unsigned int cur_state);
210
211	void (lm_cancel) (lm_lock_t lock);
212
213	int (lm_hold_lvb) (lm_lock_t lock, char **lvbp);
214	void (lm_unhold_lvb) (lm_lock_t lock, char *lvb);
215	void (lm_sync_lvb) (lm_lock_t lock, char *lvb);
216
217	/*
218	* Posix Lock oriented operations
219	*/
220
221	int (lm_plock_get) (lm_lockspace_t lockspace,
222	struct lm_lockname *name,
223	struct file file, struct file_lock fl);
224
225	int (lm_plock) (lm_lockspace_t lockspace,
226	struct lm_lockname *name,
227	struct file file, int cmd, struct file_lock fl);
228
229	int (lm_punlock) (lm_lockspace_t lockspace,
230	struct lm_lockname *name,
231	struct file file, struct file_lock fl);
232
233	/*
234	* Client oriented operations
235	*/
236
237	void (lm_recovery_done) (lm_lockspace_t lockspace, unsigned int jid,
238	unsigned int message);
239
240	struct module *lm_owner;
241	};
242
243	/*
244	* lm_mount() return values
245	*
246	* ls_jid - the journal ID this node should use
247	* ls_first - this node is the first to mount the file system
248	* ls_lvb_size - size in bytes of lock value blocks
249	* ls_lockspace - lock module's context for this file system
250	* ls_ops - lock module's functions
251	* ls_flags - lock module features
252	*/
253
254	struct lm_lockstruct {
255	unsigned int ls_jid;
256	unsigned int ls_first;
257	unsigned int ls_lvb_size;
258	lm_lockspace_t *ls_lockspace;
259	struct lm_lockops *ls_ops;
260	int ls_flags;
261	};
262
263	void __init gfs2_init_lmh(void);
264
265	/*
266	* Lock module bottom interface. A lock module makes itself available to GFS
267	* with these functions.
b3b94faa DT	268	*/
b3b94faa DT	269
3120ec54	270	int gfs2_register_lockproto(struct lm_lockops *proto);
b3b94faa	271
3120ec54	272	void gfs2_unregister_lockproto(struct lm_lockops *proto);
b3b94faa DT	273
	274	/*
	275	* Lock module top interface. GFS calls these functions when mounting or
	276	* unmounting a file system.
	277	*/
	278
	279	int gfs2_mount_lockproto(char proto_name, char table_name, char *host_data,
	280	lm_callback_t cb, lm_fsdata_t *fsdata,
	281	unsigned int min_lvb_size, int flags,
	282	struct lm_lockstruct *lockstruct,
	283	struct kobject *fskobj);
	284
	285	void gfs2_unmount_lockproto(struct lm_lockstruct *lockstruct);
	286
	287	void gfs2_withdraw_lockproto(struct lm_lockstruct *lockstruct);
	288
	289	#endif /* __LM_INTERFACE_DOT_H__ */
	290