[linux.git] / fs / gfs2 / glock.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 version 2.
 */

#ifndef __GLOCK_DOT_H__
#define __GLOCK_DOT_H__

#include <linux/sched.h>
#include <linux/parser.h>
#include "incore.h"

/* Options for hostdata parser */

enum {
	Opt_jid,
	Opt_id,
	Opt_first,
	Opt_nodir,
	Opt_err,
};

/*
 * 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
#define GL_ASYNC		0x00000040
#define GL_EXACT		0x00000080
#define GL_SKIP			0x00000100
#define GL_NOCACHE		0x00000400
  
/*
 * lm_async_cb return flags
 *
 * LM_OUT_ST_MASK
 * Masks the lower two bits of lock state in the returned value.
 *
 * LM_OUT_CANCELED
 * The lock request was canceled.
 *
 */

#define LM_OUT_ST_MASK		0x00000003
#define LM_OUT_CANCELED		0x00000008
#define LM_OUT_ERROR		0x00000004

/*
 * lm_recovery_done() messages
 */

#define LM_RD_GAVEUP		308
#define LM_RD_SUCCESS		309

#define GLR_TRYFAILED		13

#define GL_GLOCK_MAX_HOLD        (long)(HZ / 5)
#define GL_GLOCK_DFT_HOLD        (long)(HZ / 5)
#define GL_GLOCK_MIN_HOLD        (long)(10)
#define GL_GLOCK_HOLD_INCR       (long)(HZ / 20)
#define GL_GLOCK_HOLD_DECR       (long)(HZ / 40)

struct lm_lockops {
	const char *lm_proto_name;
	int (*lm_mount) (struct gfs2_sbd *sdp, const char *fsname);
 	void (*lm_unmount) (struct gfs2_sbd *sdp);
	void (*lm_withdraw) (struct gfs2_sbd *sdp);
	void (*lm_put_lock) (struct gfs2_glock *gl);
	int (*lm_lock) (struct gfs2_glock *gl, unsigned int req_state,
			unsigned int flags);
	void (*lm_cancel) (struct gfs2_glock *gl);
	const match_table_t *lm_tokens;
};

extern struct workqueue_struct *gfs2_delete_workqueue;
static inline struct gfs2_holder *gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
{
	struct gfs2_holder *gh;
	struct pid *pid;

	/* Look in glock's list of holders for one with current task as owner */
	spin_lock(&gl->gl_spin);
	pid = task_pid(current);
	list_for_each_entry(gh, &gl->gl_holders, gh_list) {
		if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
			break;
		if (gh->gh_owner_pid == pid)
			goto out;
	}
	gh = NULL;
out:
	spin_unlock(&gl->gl_spin);

	return gh;
}

static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
{
	return gl->gl_state == LM_ST_EXCLUSIVE;
}

static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
{
	return gl->gl_state == LM_ST_DEFERRED;
}

static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
{
	return gl->gl_state == LM_ST_SHARED;
}

static inline struct address_space *gfs2_glock2aspace(struct gfs2_glock *gl)
{
	if (gl->gl_ops->go_flags & GLOF_ASPACE)
		return (struct address_space *)(gl + 1);
	return NULL;
}

int gfs2_glock_get(struct gfs2_sbd *sdp,
		   u64 number, const struct gfs2_glock_operations *glops,
		   int create, struct gfs2_glock **glp);
void gfs2_glock_hold(struct gfs2_glock *gl);
void gfs2_glock_put_nolock(struct gfs2_glock *gl);
void gfs2_glock_put(struct gfs2_glock *gl);
void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
		      struct gfs2_holder *gh);
void gfs2_holder_reinit(unsigned int state, unsigned flags,
			struct gfs2_holder *gh);
void gfs2_holder_uninit(struct gfs2_holder *gh);
int gfs2_glock_nq(struct gfs2_holder *gh);
int gfs2_glock_poll(struct gfs2_holder *gh);
int gfs2_glock_wait(struct gfs2_holder *gh);
void gfs2_glock_dq(struct gfs2_holder *gh);
void gfs2_glock_dq_wait(struct gfs2_holder *gh);

void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
int gfs2_glock_nq_num(struct gfs2_sbd *sdp,
		      u64 number, const struct gfs2_glock_operations *glops,
		      unsigned int state, int flags, struct gfs2_holder *gh);

int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs);

__printf(2, 3)
void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...);

/**
 * gfs2_glock_nq_init - initialize a holder and enqueue it on a glock
 * @gl: the glock
 * @state: the state we're requesting
 * @flags: the modifier flags
 * @gh: the holder structure
 *
 * Returns: 0, GLR_*, or errno
 */

static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
				     unsigned int state, int flags,
				     struct gfs2_holder *gh)
{
	int error;

	gfs2_holder_init(gl, state, flags, gh);

	error = gfs2_glock_nq(gh);
	if (error)
		gfs2_holder_uninit(gh);

	return error;
}

extern void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state);
extern void gfs2_glock_complete(struct gfs2_glock *gl, int ret);
extern void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
extern void gfs2_glock_finish_truncate(struct gfs2_inode *ip);
extern void gfs2_glock_thaw(struct gfs2_sbd *sdp);
extern void gfs2_glock_add_to_lru(struct gfs2_glock *gl);
extern void gfs2_glock_free(struct gfs2_glock *gl);

extern int __init gfs2_glock_init(void);
extern void gfs2_glock_exit(void);

extern int gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
extern void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
extern int gfs2_register_debugfs(void);
extern void gfs2_unregister_debugfs(void);

extern const struct lm_lockops gfs2_dlm_ops;

#endif /* __GLOCK_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
e9fc2aa0	7	* of the GNU General Public License version 2.
b3b94faa DT	8	*/
	9
	10	#ifndef __GLOCK_DOT_H__
	11	#define __GLOCK_DOT_H__
	12
e8edc6e0	13	#include <linux/sched.h>
f057f6cd	14	#include <linux/parser.h>
f2f7ba52 SW	15	#include "incore.h"
f2f7ba52 SW	16
f057f6cd SW	17	/* Options for hostdata parser */
	18
	19	enum {
	20	Opt_jid,
	21	Opt_id,
	22	Opt_first,
	23	Opt_nodir,
	24	Opt_err,
	25	};
	26
	27	/*
	28	* lm_lockname types
	29	*/
	30
	31	#define LM_TYPE_RESERVED 0x00
	32	#define LM_TYPE_NONDISK 0x01
	33	#define LM_TYPE_INODE 0x02
	34	#define LM_TYPE_RGRP 0x03
	35	#define LM_TYPE_META 0x04
	36	#define LM_TYPE_IOPEN 0x05
	37	#define LM_TYPE_FLOCK 0x06
	38	#define LM_TYPE_PLOCK 0x07
	39	#define LM_TYPE_QUOTA 0x08
	40	#define LM_TYPE_JOURNAL 0x09
	41
	42	/*
	43	* lm_lock() states
	44	*
	45	* SHARED is compatible with SHARED, not with DEFERRED or EX.
	46	* DEFERRED is compatible with DEFERRED, not with SHARED or EX.
	47	*/
	48
	49	#define LM_ST_UNLOCKED 0
	50	#define LM_ST_EXCLUSIVE 1
	51	#define LM_ST_DEFERRED 2
	52	#define LM_ST_SHARED 3
	53
	54	/*
	55	* lm_lock() flags
	56	*
	57	* LM_FLAG_TRY
	58	* Don't wait to acquire the lock if it can't be granted immediately.
	59	*
	60	* LM_FLAG_TRY_1CB
	61	* Send one blocking callback if TRY is set and the lock is not granted.
	62	*
	63	* LM_FLAG_NOEXP
	64	* GFS sets this flag on lock requests it makes while doing journal recovery.
	65	* These special requests should not be blocked due to the recovery like
	66	* ordinary locks would be.
	67	*
	68	* LM_FLAG_ANY
	69	* A SHARED request may also be granted in DEFERRED, or a DEFERRED request may
	70	* also be granted in SHARED. The preferred state is whichever is compatible
	71	* with other granted locks, or the specified state if no other locks exist.
	72	*
	73	* LM_FLAG_PRIORITY
	74	* Override fairness considerations. Suppose a lock is held in a shared state
	75	* and there is a pending request for the deferred state. A shared lock
	76	* request with the priority flag would be allowed to bypass the deferred
	77	* request and directly join the other shared lock. A shared lock request
	78	* without the priority flag might be forced to wait until the deferred
	79	* requested had acquired and released the lock.
	80	*/
81
b3b94faa DT	82	#define LM_FLAG_TRY 0x00000001
	83	#define LM_FLAG_TRY_1CB 0x00000002
	84	#define LM_FLAG_NOEXP 0x00000004
	85	#define LM_FLAG_ANY 0x00000008
f057f6cd SW	86	#define LM_FLAG_PRIORITY 0x00000010
	87	#define GL_ASYNC 0x00000040
	88	#define GL_EXACT 0x00000080
	89	#define GL_SKIP 0x00000100
f057f6cd SW	90	#define GL_NOCACHE 0x00000400
	91
	92	/*
921169ca	93	* lm_async_cb return flags
f057f6cd SW	94	*
	95	* LM_OUT_ST_MASK
	96	* Masks the lower two bits of lock state in the returned value.
	97	*
	98	* LM_OUT_CANCELED
	99	* The lock request was canceled.
	100	*
f057f6cd SW	101	*/
	102
	103	#define LM_OUT_ST_MASK 0x00000003
	104	#define LM_OUT_CANCELED 0x00000008
921169ca	105	#define LM_OUT_ERROR 0x00000004
f057f6cd SW	106
	107	/*
	108	* lm_recovery_done() messages
	109	*/
	110
	111	#define LM_RD_GAVEUP 308
	112	#define LM_RD_SUCCESS 309
	113
	114	#define GLR_TRYFAILED 13
	115
7cf8dcd3 BP	116	#define GL_GLOCK_MAX_HOLD (long)(HZ / 5)
	117	#define GL_GLOCK_DFT_HOLD (long)(HZ / 5)
	118	#define GL_GLOCK_MIN_HOLD (long)(10)
	119	#define GL_GLOCK_HOLD_INCR (long)(HZ / 20)
	120	#define GL_GLOCK_HOLD_DECR (long)(HZ / 40)
	121
f057f6cd SW	122	struct lm_lockops {
	123	const char *lm_proto_name;
	124	int (lm_mount) (struct gfs2_sbd sdp, const char *fsname);
	125	void (lm_unmount) (struct gfs2_sbd sdp);
	126	void (lm_withdraw) (struct gfs2_sbd sdp);
bc015cb8	127	void (lm_put_lock) (struct gfs2_glock gl);
921169ca SW	128	int (lm_lock) (struct gfs2_glock gl, unsigned int req_state,
921169ca SW	129	unsigned int flags);
f057f6cd SW	130	void (lm_cancel) (struct gfs2_glock gl);
	131	const match_table_t *lm_tokens;
	132	};
	133
b94a170e	134	extern struct workqueue_struct *gfs2_delete_workqueue;
7afd88d9	135	static inline struct gfs2_holder gfs2_glock_is_locked_by_me(struct gfs2_glock gl)
b3b94faa DT	136	{
b3b94faa DT	137	struct gfs2_holder *gh;
b1e058da	138	struct pid *pid;
b3b94faa DT	139
	140	/* Look in glock's list of holders for one with current task as owner */
	141	spin_lock(&gl->gl_spin);
b1e058da	142	pid = task_pid(current);
b3b94faa	143	list_for_each_entry(gh, &gl->gl_holders, gh_list) {
6802e340 SW	144	if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
6802e340 SW	145	break;
7afd88d9 SW	146	if (gh->gh_owner_pid == pid)
7afd88d9 SW	147	goto out;
b3b94faa	148	}
7afd88d9 SW	149	gh = NULL;
7afd88d9 SW	150	out:
b3b94faa DT	151	spin_unlock(&gl->gl_spin);
b3b94faa DT	152
7afd88d9	153	return gh;
b3b94faa DT	154	}
	155
	156	static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
	157	{
50299965	158	return gl->gl_state == LM_ST_EXCLUSIVE;
b3b94faa DT	159	}
	160
	161	static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
	162	{
50299965	163	return gl->gl_state == LM_ST_DEFERRED;
b3b94faa DT	164	}
	165
	166	static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
	167	{
50299965	168	return gl->gl_state == LM_ST_SHARED;
b3b94faa DT	169	}
b3b94faa DT	170
009d8518 SW	171	static inline struct address_space gfs2_glock2aspace(struct gfs2_glock gl)
	172	{
	173	if (gl->gl_ops->go_flags & GLOF_ASPACE)
	174	return (struct address_space *)(gl + 1);
	175	return NULL;
	176	}
	177
b3b94faa	178	int gfs2_glock_get(struct gfs2_sbd *sdp,
cd915493	179	u64 number, const struct gfs2_glock_operations *glops,
b3b94faa	180	int create, struct gfs2_glock **glp);
b94a170e BM	181	void gfs2_glock_hold(struct gfs2_glock *gl);
b94a170e BM	182	void gfs2_glock_put_nolock(struct gfs2_glock *gl);
bc015cb8	183	void gfs2_glock_put(struct gfs2_glock *gl);
190562bd	184	void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
b3b94faa	185	struct gfs2_holder *gh);
190562bd SW	186	void gfs2_holder_reinit(unsigned int state, unsigned flags,
190562bd SW	187	struct gfs2_holder *gh);
b3b94faa	188	void gfs2_holder_uninit(struct gfs2_holder *gh);
b3b94faa DT	189	int gfs2_glock_nq(struct gfs2_holder *gh);
	190	int gfs2_glock_poll(struct gfs2_holder *gh);
	191	int gfs2_glock_wait(struct gfs2_holder *gh);
	192	void gfs2_glock_dq(struct gfs2_holder *gh);
d93cfa98	193	void gfs2_glock_dq_wait(struct gfs2_holder *gh);
b3b94faa	194
b3b94faa DT	195	void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
b3b94faa DT	196	int gfs2_glock_nq_num(struct gfs2_sbd *sdp,
cd915493	197	u64 number, const struct gfs2_glock_operations *glops,
b3b94faa DT	198	unsigned int state, int flags, struct gfs2_holder *gh);
	199
	200	int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
	201	void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
	202	void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs);
edc221d0	203
b9075fa9	204	__printf(2, 3)
6802e340	205	void gfs2_print_dbg(struct seq_file seq, const char fmt, ...);
b3b94faa	206
d0dc80db	207	/**
33027af6	208	* gfs2_glock_nq_init - initialize a holder and enqueue it on a glock
d0dc80db SW	209	* @gl: the glock
	210	* @state: the state we're requesting
	211	* @flags: the modifier flags
	212	* @gh: the holder structure
	213	*
	214	* Returns: 0, GLR_*, or errno
	215	*/
	216
	217	static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
	218	unsigned int state, int flags,
	219	struct gfs2_holder *gh)
	220	{
	221	int error;
	222
	223	gfs2_holder_init(gl, state, flags, gh);
	224
	225	error = gfs2_glock_nq(gh);
	226	if (error)
	227	gfs2_holder_uninit(gh);
	228
	229	return error;
	230	}
	231
bc015cb8 SW	232	extern void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state);
bc015cb8 SW	233	extern void gfs2_glock_complete(struct gfs2_glock *gl, int ret);
bc015cb8 SW	234	extern void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
	235	extern void gfs2_glock_finish_truncate(struct gfs2_inode *ip);
	236	extern void gfs2_glock_thaw(struct gfs2_sbd *sdp);
29687a2a	237	extern void gfs2_glock_add_to_lru(struct gfs2_glock *gl);
fc0e38da	238	extern void gfs2_glock_free(struct gfs2_glock *gl);
bc015cb8 SW	239
	240	extern int __init gfs2_glock_init(void);
	241	extern void gfs2_glock_exit(void);
	242
	243	extern int gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
	244	extern void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
	245	extern int gfs2_register_debugfs(void);
	246	extern void gfs2_unregister_debugfs(void);
85d1da67	247
f057f6cd SW	248	extern const struct lm_lockops gfs2_dlm_ops;
f057f6cd SW	249
b3b94faa	250	#endif /* __GLOCK_DOT_H__ */