xref: /openbmc/linux/fs/gfs2/glock.h (revision edc221d0)
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 
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 
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_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, struct gfs2_glock *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
138 
139 #define GL_ASYNC		0x00000040
140 #define GL_EXACT		0x00000080
141 #define GL_SKIP			0x00000100
142 #define GL_NOCACHE		0x00000400
143 
144 #define GLR_TRYFAILED		13
145 
146 extern struct workqueue_struct *gfs2_delete_workqueue;
147 static inline struct gfs2_holder *gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
148 {
149 	struct gfs2_holder *gh;
150 	struct pid *pid;
151 
152 	/* Look in glock's list of holders for one with current task as owner */
153 	spin_lock(&gl->gl_spin);
154 	pid = task_pid(current);
155 	list_for_each_entry(gh, &gl->gl_holders, gh_list) {
156 		if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
157 			break;
158 		if (gh->gh_owner_pid == pid)
159 			goto out;
160 	}
161 	gh = NULL;
162 out:
163 	spin_unlock(&gl->gl_spin);
164 
165 	return gh;
166 }
167 
168 static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
169 {
170 	return gl->gl_state == LM_ST_EXCLUSIVE;
171 }
172 
173 static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
174 {
175 	return gl->gl_state == LM_ST_DEFERRED;
176 }
177 
178 static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
179 {
180 	return gl->gl_state == LM_ST_SHARED;
181 }
182 
183 static inline struct address_space *gfs2_glock2aspace(struct gfs2_glock *gl)
184 {
185 	if (gl->gl_ops->go_flags & GLOF_ASPACE)
186 		return (struct address_space *)(gl + 1);
187 	return NULL;
188 }
189 
190 int gfs2_glock_get(struct gfs2_sbd *sdp,
191 		   u64 number, const struct gfs2_glock_operations *glops,
192 		   int create, struct gfs2_glock **glp);
193 void gfs2_glock_hold(struct gfs2_glock *gl);
194 void gfs2_glock_put_nolock(struct gfs2_glock *gl);
195 int gfs2_glock_put(struct gfs2_glock *gl);
196 void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
197 		      struct gfs2_holder *gh);
198 void gfs2_holder_reinit(unsigned int state, unsigned flags,
199 			struct gfs2_holder *gh);
200 void gfs2_holder_uninit(struct gfs2_holder *gh);
201 int gfs2_glock_nq(struct gfs2_holder *gh);
202 int gfs2_glock_poll(struct gfs2_holder *gh);
203 int gfs2_glock_wait(struct gfs2_holder *gh);
204 void gfs2_glock_dq(struct gfs2_holder *gh);
205 void gfs2_glock_dq_wait(struct gfs2_holder *gh);
206 
207 void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
208 int gfs2_glock_nq_num(struct gfs2_sbd *sdp,
209 		      u64 number, const struct gfs2_glock_operations *glops,
210 		      unsigned int state, int flags, struct gfs2_holder *gh);
211 
212 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
213 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
214 void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs);
215 
216 __attribute__ ((format(printf, 2, 3)))
217 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...);
218 
219 /**
220  * gfs2_glock_nq_init - initialize a holder and enqueue it on a glock
221  * @gl: the glock
222  * @state: the state we're requesting
223  * @flags: the modifier flags
224  * @gh: the holder structure
225  *
226  * Returns: 0, GLR_*, or errno
227  */
228 
229 static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
230 				     unsigned int state, int flags,
231 				     struct gfs2_holder *gh)
232 {
233 	int error;
234 
235 	gfs2_holder_init(gl, state, flags, gh);
236 
237 	error = gfs2_glock_nq(gh);
238 	if (error)
239 		gfs2_holder_uninit(gh);
240 
241 	return error;
242 }
243 
244 /*  Lock Value Block functions  */
245 
246 int gfs2_lvb_hold(struct gfs2_glock *gl);
247 void gfs2_lvb_unhold(struct gfs2_glock *gl);
248 
249 void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state);
250 void gfs2_glock_complete(struct gfs2_glock *gl, int ret);
251 void gfs2_reclaim_glock(struct gfs2_sbd *sdp);
252 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
253 void gfs2_glock_finish_truncate(struct gfs2_inode *ip);
254 void gfs2_glock_thaw(struct gfs2_sbd *sdp);
255 
256 int __init gfs2_glock_init(void);
257 void gfs2_glock_exit(void);
258 
259 int gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
260 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
261 int gfs2_register_debugfs(void);
262 void gfs2_unregister_debugfs(void);
263 
264 extern const struct lm_lockops gfs2_dlm_ops;
265 
266 #endif /* __GLOCK_DOT_H__ */
267