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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 __GLOCK_DOT_H__
11#define __GLOCK_DOT_H__
12
13#include <linux/sched.h>
14#include <linux/parser.h>
15#include "incore.h"
16
17/* Options for hostdata parser */
18
19enum {
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
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
86#define LM_FLAG_PRIORITY 0x00000010
87#define GL_ASYNC 0x00000040
88#define GL_EXACT 0x00000080
89#define GL_SKIP 0x00000100
90#define GL_NOCACHE 0x00000400
91
92/*
93 * lm_async_cb return flags
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 *
101 */
102
103#define LM_OUT_ST_MASK 0x00000003
104#define LM_OUT_CANCELED 0x00000008
105#define LM_OUT_ERROR 0x00000004
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
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
122struct lm_lockops {
123 const char *lm_proto_name;
124 int (*lm_mount) (struct gfs2_sbd *sdp, const char *table);
125 void (*lm_first_done) (struct gfs2_sbd *sdp);
126 void (*lm_recovery_result) (struct gfs2_sbd *sdp, unsigned int jid,
127 unsigned int result);
128 void (*lm_unmount) (struct gfs2_sbd *sdp);
129 void (*lm_withdraw) (struct gfs2_sbd *sdp);
130 void (*lm_put_lock) (struct gfs2_glock *gl);
131 int (*lm_lock) (struct gfs2_glock *gl, unsigned int req_state,
132 unsigned int flags);
133 void (*lm_cancel) (struct gfs2_glock *gl);
134 const match_table_t *lm_tokens;
135};
136
137extern struct workqueue_struct *gfs2_delete_workqueue;
138static inline struct gfs2_holder *gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
139{
140 struct gfs2_holder *gh;
141 struct pid *pid;
142
143 /* Look in glock's list of holders for one with current task as owner */
144 spin_lock(&gl->gl_spin);
145 pid = task_pid(current);
146 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
147 if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
148 break;
149 if (gh->gh_owner_pid == pid)
150 goto out;
151 }
152 gh = NULL;
153out:
154 spin_unlock(&gl->gl_spin);
155
156 return gh;
157}
158
159static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
160{
161 return gl->gl_state == LM_ST_EXCLUSIVE;
162}
163
164static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
165{
166 return gl->gl_state == LM_ST_DEFERRED;
167}
168
169static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
170{
171 return gl->gl_state == LM_ST_SHARED;
172}
173
174static inline struct address_space *gfs2_glock2aspace(struct gfs2_glock *gl)
175{
176 if (gl->gl_ops->go_flags & GLOF_ASPACE)
177 return (struct address_space *)(gl + 1);
178 return NULL;
179}
180
181int gfs2_glock_get(struct gfs2_sbd *sdp,
182 u64 number, const struct gfs2_glock_operations *glops,
183 int create, struct gfs2_glock **glp);
184void gfs2_glock_hold(struct gfs2_glock *gl);
185void gfs2_glock_put_nolock(struct gfs2_glock *gl);
186void gfs2_glock_put(struct gfs2_glock *gl);
187void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
188 struct gfs2_holder *gh);
189void gfs2_holder_reinit(unsigned int state, unsigned flags,
190 struct gfs2_holder *gh);
191void gfs2_holder_uninit(struct gfs2_holder *gh);
192int gfs2_glock_nq(struct gfs2_holder *gh);
193int gfs2_glock_poll(struct gfs2_holder *gh);
194int gfs2_glock_wait(struct gfs2_holder *gh);
195void gfs2_glock_dq(struct gfs2_holder *gh);
196void gfs2_glock_dq_wait(struct gfs2_holder *gh);
197
198void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
199int gfs2_glock_nq_num(struct gfs2_sbd *sdp,
200 u64 number, const struct gfs2_glock_operations *glops,
201 unsigned int state, int flags, struct gfs2_holder *gh);
202
203int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
204void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
205void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs);
206
207__printf(2, 3)
208void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...);
209
210/**
211 * gfs2_glock_nq_init - initialize a holder and enqueue it on a glock
212 * @gl: the glock
213 * @state: the state we're requesting
214 * @flags: the modifier flags
215 * @gh: the holder structure
216 *
217 * Returns: 0, GLR_*, or errno
218 */
219
220static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
221 unsigned int state, int flags,
222 struct gfs2_holder *gh)
223{
224 int error;
225
226 gfs2_holder_init(gl, state, flags, gh);
227
228 error = gfs2_glock_nq(gh);
229 if (error)
230 gfs2_holder_uninit(gh);
231
232 return error;
233}
234
235extern void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state);
236extern void gfs2_glock_complete(struct gfs2_glock *gl, int ret);
237extern void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
238extern void gfs2_glock_finish_truncate(struct gfs2_inode *ip);
239extern void gfs2_glock_thaw(struct gfs2_sbd *sdp);
240extern void gfs2_glock_add_to_lru(struct gfs2_glock *gl);
241extern void gfs2_glock_free(struct gfs2_glock *gl);
242
243extern int __init gfs2_glock_init(void);
244extern void gfs2_glock_exit(void);
245
246extern int gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
247extern void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
248extern int gfs2_register_debugfs(void);
249extern void gfs2_unregister_debugfs(void);
250
251extern const struct lm_lockops gfs2_dlm_ops;
252
253#endif /* __GLOCK_DOT_H__ */
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 __GLOCK_DOT_H__
11#define __GLOCK_DOT_H__
12
13#include <linux/sched.h>
14#include <linux/parser.h>
15#include "incore.h"
16#include "util.h"
17
18/* Options for hostdata parser */
19
20enum {
21 Opt_jid,
22 Opt_id,
23 Opt_first,
24 Opt_nodir,
25 Opt_err,
26};
27
28/*
29 * lm_lockname types
30 */
31
32#define LM_TYPE_RESERVED 0x00
33#define LM_TYPE_NONDISK 0x01
34#define LM_TYPE_INODE 0x02
35#define LM_TYPE_RGRP 0x03
36#define LM_TYPE_META 0x04
37#define LM_TYPE_IOPEN 0x05
38#define LM_TYPE_FLOCK 0x06
39#define LM_TYPE_PLOCK 0x07
40#define LM_TYPE_QUOTA 0x08
41#define LM_TYPE_JOURNAL 0x09
42
43/*
44 * lm_lock() states
45 *
46 * SHARED is compatible with SHARED, not with DEFERRED or EX.
47 * DEFERRED is compatible with DEFERRED, not with SHARED or EX.
48 */
49
50#define LM_ST_UNLOCKED 0
51#define LM_ST_EXCLUSIVE 1
52#define LM_ST_DEFERRED 2
53#define LM_ST_SHARED 3
54
55/*
56 * lm_lock() flags
57 *
58 * LM_FLAG_TRY
59 * Don't wait to acquire the lock if it can't be granted immediately.
60 *
61 * LM_FLAG_TRY_1CB
62 * Send one blocking callback if TRY is set and the lock is not granted.
63 *
64 * LM_FLAG_NOEXP
65 * GFS sets this flag on lock requests it makes while doing journal recovery.
66 * These special requests should not be blocked due to the recovery like
67 * ordinary locks would be.
68 *
69 * LM_FLAG_ANY
70 * A SHARED request may also be granted in DEFERRED, or a DEFERRED request may
71 * also be granted in SHARED. The preferred state is whichever is compatible
72 * with other granted locks, or the specified state if no other locks exist.
73 *
74 * LM_FLAG_PRIORITY
75 * Override fairness considerations. Suppose a lock is held in a shared state
76 * and there is a pending request for the deferred state. A shared lock
77 * request with the priority flag would be allowed to bypass the deferred
78 * request and directly join the other shared lock. A shared lock request
79 * without the priority flag might be forced to wait until the deferred
80 * requested had acquired and released the lock.
81 */
82
83#define LM_FLAG_TRY 0x0001
84#define LM_FLAG_TRY_1CB 0x0002
85#define LM_FLAG_NOEXP 0x0004
86#define LM_FLAG_ANY 0x0008
87#define LM_FLAG_PRIORITY 0x0010
88#define GL_ASYNC 0x0040
89#define GL_EXACT 0x0080
90#define GL_SKIP 0x0100
91#define GL_NOCACHE 0x0400
92
93/*
94 * 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 */
103
104#define LM_OUT_ST_MASK 0x00000003
105#define LM_OUT_CANCELED 0x00000008
106#define LM_OUT_ERROR 0x00000004
107
108/*
109 * lm_recovery_done() messages
110 */
111
112#define LM_RD_GAVEUP 308
113#define LM_RD_SUCCESS 309
114
115#define GLR_TRYFAILED 13
116
117#define GL_GLOCK_MAX_HOLD (long)(HZ / 5)
118#define GL_GLOCK_DFT_HOLD (long)(HZ / 5)
119#define GL_GLOCK_MIN_HOLD (long)(10)
120#define GL_GLOCK_HOLD_INCR (long)(HZ / 20)
121#define GL_GLOCK_HOLD_DECR (long)(HZ / 40)
122
123struct lm_lockops {
124 const char *lm_proto_name;
125 int (*lm_mount) (struct gfs2_sbd *sdp, const char *table);
126 void (*lm_first_done) (struct gfs2_sbd *sdp);
127 void (*lm_recovery_result) (struct gfs2_sbd *sdp, unsigned int jid,
128 unsigned int result);
129 void (*lm_unmount) (struct gfs2_sbd *sdp);
130 void (*lm_withdraw) (struct gfs2_sbd *sdp);
131 void (*lm_put_lock) (struct gfs2_glock *gl);
132 int (*lm_lock) (struct gfs2_glock *gl, unsigned int req_state,
133 unsigned int flags);
134 void (*lm_cancel) (struct gfs2_glock *gl);
135 const match_table_t *lm_tokens;
136};
137
138extern struct workqueue_struct *gfs2_delete_workqueue;
139static inline struct gfs2_holder *gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
140{
141 struct gfs2_holder *gh;
142 struct pid *pid;
143
144 /* Look in glock's list of holders for one with current task as owner */
145 spin_lock(&gl->gl_lockref.lock);
146 pid = task_pid(current);
147 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
148 if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
149 break;
150 if (gh->gh_owner_pid == pid)
151 goto out;
152 }
153 gh = NULL;
154out:
155 spin_unlock(&gl->gl_lockref.lock);
156
157 return gh;
158}
159
160static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
161{
162 return gl->gl_state == LM_ST_EXCLUSIVE;
163}
164
165static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
166{
167 return gl->gl_state == LM_ST_DEFERRED;
168}
169
170static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
171{
172 return gl->gl_state == LM_ST_SHARED;
173}
174
175static inline struct address_space *gfs2_glock2aspace(struct gfs2_glock *gl)
176{
177 if (gl->gl_ops->go_flags & GLOF_ASPACE)
178 return (struct address_space *)(gl + 1);
179 return NULL;
180}
181
182extern int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
183 const struct gfs2_glock_operations *glops,
184 int create, struct gfs2_glock **glp);
185extern void gfs2_glock_hold(struct gfs2_glock *gl);
186extern void gfs2_glock_put(struct gfs2_glock *gl);
187extern void gfs2_glock_queue_put(struct gfs2_glock *gl);
188extern void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state,
189 u16 flags, struct gfs2_holder *gh);
190extern void gfs2_holder_reinit(unsigned int state, u16 flags,
191 struct gfs2_holder *gh);
192extern void gfs2_holder_uninit(struct gfs2_holder *gh);
193extern int gfs2_glock_nq(struct gfs2_holder *gh);
194extern int gfs2_glock_poll(struct gfs2_holder *gh);
195extern int gfs2_glock_wait(struct gfs2_holder *gh);
196extern void gfs2_glock_dq(struct gfs2_holder *gh);
197extern void gfs2_glock_dq_wait(struct gfs2_holder *gh);
198extern void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
199extern int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
200 const struct gfs2_glock_operations *glops,
201 unsigned int state, u16 flags,
202 struct gfs2_holder *gh);
203extern int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
204extern void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
205extern void gfs2_dump_glock(struct seq_file *seq, const struct gfs2_glock *gl);
206#define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) { gfs2_dump_glock(NULL, gl); BUG(); } } while(0)
207extern __printf(2, 3)
208void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...);
209
210/**
211 * gfs2_glock_nq_init - initialize a holder and enqueue it on a glock
212 * @gl: the glock
213 * @state: the state we're requesting
214 * @flags: the modifier flags
215 * @gh: the holder structure
216 *
217 * Returns: 0, GLR_*, or errno
218 */
219
220static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
221 unsigned int state, u16 flags,
222 struct gfs2_holder *gh)
223{
224 int error;
225
226 gfs2_holder_init(gl, state, flags, gh);
227
228 error = gfs2_glock_nq(gh);
229 if (error)
230 gfs2_holder_uninit(gh);
231
232 return error;
233}
234
235extern void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state);
236extern void gfs2_glock_complete(struct gfs2_glock *gl, int ret);
237extern void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
238extern void gfs2_glock_finish_truncate(struct gfs2_inode *ip);
239extern void gfs2_glock_thaw(struct gfs2_sbd *sdp);
240extern void gfs2_glock_add_to_lru(struct gfs2_glock *gl);
241extern void gfs2_glock_free(struct gfs2_glock *gl);
242
243extern int __init gfs2_glock_init(void);
244extern void gfs2_glock_exit(void);
245
246extern int gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
247extern void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
248extern int gfs2_register_debugfs(void);
249extern void gfs2_unregister_debugfs(void);
250
251extern const struct lm_lockops gfs2_dlm_ops;
252
253static inline void gfs2_holder_mark_uninitialized(struct gfs2_holder *gh)
254{
255 gh->gh_gl = NULL;
256}
257
258static inline bool gfs2_holder_initialized(struct gfs2_holder *gh)
259{
260 return gh->gh_gl;
261}
262
263/**
264 * glock_set_object - set the gl_object field of a glock
265 * @gl: the glock
266 * @object: the object
267 */
268static inline void glock_set_object(struct gfs2_glock *gl, void *object)
269{
270 spin_lock(&gl->gl_lockref.lock);
271 if (gfs2_assert_warn(gl->gl_name.ln_sbd, gl->gl_object == NULL))
272 gfs2_dump_glock(NULL, gl);
273 gl->gl_object = object;
274 spin_unlock(&gl->gl_lockref.lock);
275}
276
277/**
278 * glock_clear_object - clear the gl_object field of a glock
279 * @gl: the glock
280 * @object: the object
281 *
282 * I'd love to similarly add this:
283 * else if (gfs2_assert_warn(gl->gl_sbd, gl->gl_object == object))
284 * gfs2_dump_glock(NULL, gl);
285 * Unfortunately, that's not possible because as soon as gfs2_delete_inode
286 * frees the block in the rgrp, another process can reassign it for an I_NEW
287 * inode in gfs2_create_inode because that calls new_inode, not gfs2_iget.
288 * That means gfs2_delete_inode may subsequently try to call this function
289 * for a glock that's already pointing to a brand new inode. If we clear the
290 * new inode's gl_object, we'll introduce metadata corruption. Function
291 * gfs2_delete_inode calls clear_inode which calls gfs2_clear_inode which also
292 * tries to clear gl_object, so it's more than just gfs2_delete_inode.
293 *
294 */
295static inline void glock_clear_object(struct gfs2_glock *gl, void *object)
296{
297 spin_lock(&gl->gl_lockref.lock);
298 if (gl->gl_object == object)
299 gl->gl_object = NULL;
300 spin_unlock(&gl->gl_lockref.lock);
301}
302
303#endif /* __GLOCK_DOT_H__ */