[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_ATIME		0x00000200
#define GL_NOCACHE		0x00000400
  
/*
 * 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_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_CANCELED		0x00000008
#define LM_OUT_ASYNC		0x00000080
#define LM_OUT_ERROR		0x00000100

/*
 * lm_recovery_done() messages
 */

#define LM_RD_GAVEUP		308
#define LM_RD_SUCCESS		309

#define GLR_TRYFAILED		13

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 kmem_cache *cachep, void *gl);
	unsigned 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;
};

#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

#define GLR_TRYFAILED		13

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 int gfs2_glock_is_blocking(struct gfs2_glock *gl)
{
	int ret;
	spin_lock(&gl->gl_spin);
	ret = test_bit(GLF_DEMOTE, &gl->gl_flags);
	spin_unlock(&gl->gl_spin);
	return ret;
}

int gfs2_glock_get(struct gfs2_sbd *sdp,
		   u64 number, const struct gfs2_glock_operations *glops,
		   int create, struct gfs2_glock **glp);
int 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);
void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...);

/**
 * gfs2_glock_nq_init - intialize 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;
}

/*  Lock Value Block functions  */

int gfs2_lvb_hold(struct gfs2_glock *gl);
void gfs2_lvb_unhold(struct gfs2_glock *gl);

void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state);
void gfs2_glock_complete(struct gfs2_glock *gl, int ret);
void gfs2_reclaim_glock(struct gfs2_sbd *sdp);
void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
void gfs2_glock_finish_truncate(struct gfs2_inode *ip);
void gfs2_glock_thaw(struct gfs2_sbd *sdp);

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

int gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
int gfs2_register_debugfs(void);
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
	90	#define GL_ATIME 0x00000200
	91	#define GL_NOCACHE 0x00000400
	92
	93	/*
	94	* lm_lock() and lm_async_cb return flags
	95	*
	96	* LM_OUT_ST_MASK
	97	* Masks the lower two bits of lock state in the returned value.
	98	*
	99	* LM_OUT_CANCELED
	100	* The lock request was canceled.
	101	*
	102	* LM_OUT_ASYNC
	103	* The result of the request will be returned in an LM_CB_ASYNC callback.
	104	*
	105	*/
	106
	107	#define LM_OUT_ST_MASK 0x00000003
	108	#define LM_OUT_CANCELED 0x00000008
	109	#define LM_OUT_ASYNC 0x00000080
	110	#define LM_OUT_ERROR 0x00000100
	111
	112	/*
	113	* lm_recovery_done() messages
	114	*/
	115
	116	#define LM_RD_GAVEUP 308
	117	#define LM_RD_SUCCESS 309
	118
	119	#define GLR_TRYFAILED 13
	120
	121	struct lm_lockops {
	122	const char *lm_proto_name;
	123	int (lm_mount) (struct gfs2_sbd sdp, const char *fsname);
	124	void (lm_unmount) (struct gfs2_sbd sdp);
	125	void (lm_withdraw) (struct gfs2_sbd sdp);
	126	void (lm_put_lock) (struct kmem_cache cachep, void *gl);
	127	unsigned int (lm_lock) (struct gfs2_glock gl,
	128	unsigned int req_state, unsigned int flags);
	129	void (lm_cancel) (struct gfs2_glock gl);
	130	const match_table_t *lm_tokens;
	131	};
	132
	133	#define LM_FLAG_TRY 0x00000001
	134	#define LM_FLAG_TRY_1CB 0x00000002
	135	#define LM_FLAG_NOEXP 0x00000004
	136	#define LM_FLAG_ANY 0x00000008
	137	#define LM_FLAG_PRIORITY 0x00000010
b3b94faa	138
b3b94faa DT	139	#define GL_ASYNC 0x00000040
	140	#define GL_EXACT 0x00000080
	141	#define GL_SKIP 0x00000100
b3b94faa	142	#define GL_NOCACHE 0x00000400
b3b94faa DT	143
b3b94faa DT	144	#define GLR_TRYFAILED 13
b3b94faa	145
7afd88d9	146	static inline struct gfs2_holder gfs2_glock_is_locked_by_me(struct gfs2_glock gl)
b3b94faa DT	147	{
b3b94faa DT	148	struct gfs2_holder *gh;
b1e058da	149	struct pid *pid;
b3b94faa DT	150
	151	/* Look in glock's list of holders for one with current task as owner */
	152	spin_lock(&gl->gl_spin);
b1e058da	153	pid = task_pid(current);
b3b94faa	154	list_for_each_entry(gh, &gl->gl_holders, gh_list) {
6802e340 SW	155	if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
6802e340 SW	156	break;
7afd88d9 SW	157	if (gh->gh_owner_pid == pid)
7afd88d9 SW	158	goto out;
b3b94faa	159	}
7afd88d9 SW	160	gh = NULL;
7afd88d9 SW	161	out:
b3b94faa DT	162	spin_unlock(&gl->gl_spin);
b3b94faa DT	163
7afd88d9	164	return gh;
b3b94faa DT	165	}
	166
	167	static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
	168	{
50299965	169	return gl->gl_state == LM_ST_EXCLUSIVE;
b3b94faa DT	170	}
	171
	172	static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
	173	{
50299965	174	return gl->gl_state == LM_ST_DEFERRED;
b3b94faa DT	175	}
	176
	177	static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
	178	{
50299965	179	return gl->gl_state == LM_ST_SHARED;
b3b94faa DT	180	}
	181
	182	static inline int gfs2_glock_is_blocking(struct gfs2_glock *gl)
	183	{
	184	int ret;
	185	spin_lock(&gl->gl_spin);
6802e340	186	ret = test_bit(GLF_DEMOTE, &gl->gl_flags);
b3b94faa DT	187	spin_unlock(&gl->gl_spin);
	188	return ret;
	189	}
	190
b3b94faa	191	int gfs2_glock_get(struct gfs2_sbd *sdp,
cd915493	192	u64 number, const struct gfs2_glock_operations *glops,
b3b94faa	193	int create, struct gfs2_glock **glp);
b3b94faa	194	int gfs2_glock_put(struct gfs2_glock *gl);
190562bd	195	void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
b3b94faa	196	struct gfs2_holder *gh);
190562bd SW	197	void gfs2_holder_reinit(unsigned int state, unsigned flags,
190562bd SW	198	struct gfs2_holder *gh);
b3b94faa	199	void gfs2_holder_uninit(struct gfs2_holder *gh);
b3b94faa DT	200	int gfs2_glock_nq(struct gfs2_holder *gh);
	201	int gfs2_glock_poll(struct gfs2_holder *gh);
	202	int gfs2_glock_wait(struct gfs2_holder *gh);
	203	void gfs2_glock_dq(struct gfs2_holder *gh);
d93cfa98	204	void gfs2_glock_dq_wait(struct gfs2_holder *gh);
b3b94faa	205
b3b94faa DT	206	void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
b3b94faa DT	207	int gfs2_glock_nq_num(struct gfs2_sbd *sdp,
cd915493	208	u64 number, const struct gfs2_glock_operations *glops,
b3b94faa DT	209	unsigned int state, int flags, struct gfs2_holder *gh);
	210
	211	int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
	212	void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
	213	void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs);
6802e340	214	void gfs2_print_dbg(struct seq_file seq, const char fmt, ...);
b3b94faa	215
d0dc80db SW	216	/**
	217	* gfs2_glock_nq_init - intialize a holder and enqueue it on a glock
	218	* @gl: the glock
	219	* @state: the state we're requesting
	220	* @flags: the modifier flags
	221	* @gh: the holder structure
	222	*
	223	* Returns: 0, GLR_*, or errno
	224	*/
	225
	226	static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
	227	unsigned int state, int flags,
	228	struct gfs2_holder *gh)
	229	{
	230	int error;
	231
	232	gfs2_holder_init(gl, state, flags, gh);
	233
	234	error = gfs2_glock_nq(gh);
	235	if (error)
	236	gfs2_holder_uninit(gh);
	237
	238	return error;
	239	}
	240
b3b94faa DT	241	/* Lock Value Block functions */
	242
	243	int gfs2_lvb_hold(struct gfs2_glock *gl);
	244	void gfs2_lvb_unhold(struct gfs2_glock *gl);
b3b94faa	245
f057f6cd SW	246	void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state);
f057f6cd SW	247	void gfs2_glock_complete(struct gfs2_glock *gl, int ret);
b3b94faa	248	void gfs2_reclaim_glock(struct gfs2_sbd *sdp);
fefc03bf	249	void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
813e0c46	250	void gfs2_glock_finish_truncate(struct gfs2_inode *ip);
f057f6cd	251	void gfs2_glock_thaw(struct gfs2_sbd *sdp);
b3b94faa	252
85d1da67	253	int __init gfs2_glock_init(void);
8fbbfd21 SW	254	void gfs2_glock_exit(void);
8fbbfd21 SW	255
7c52b166 RP	256	int gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
	257	void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
	258	int gfs2_register_debugfs(void);
	259	void gfs2_unregister_debugfs(void);
85d1da67	260
f057f6cd SW	261	extern const struct lm_lockops gfs2_dlm_ops;
f057f6cd SW	262
b3b94faa	263	#endif /* __GLOCK_DOT_H__ */