1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
4  * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
5  */
6 
7 #ifndef __GLOCK_DOT_H__
8 #define __GLOCK_DOT_H__
9 
10 #include <linux/sched.h>
11 #include <linux/parser.h>
12 #include "incore.h"
13 #include "util.h"
14 
15 /* Options for hostdata parser */
16 
17 enum {
18 	Opt_jid,
19 	Opt_id,
20 	Opt_first,
21 	Opt_nodir,
22 	Opt_err,
23 };
24 
25 /*
26  * lm_lockname types
27  */
28 
29 #define LM_TYPE_RESERVED	0x00
30 #define LM_TYPE_NONDISK		0x01
31 #define LM_TYPE_INODE		0x02
32 #define LM_TYPE_RGRP		0x03
33 #define LM_TYPE_META		0x04
34 #define LM_TYPE_IOPEN		0x05
35 #define LM_TYPE_FLOCK		0x06
36 #define LM_TYPE_PLOCK		0x07
37 #define LM_TYPE_QUOTA		0x08
38 #define LM_TYPE_JOURNAL		0x09
39 
40 /*
41  * lm_lock() states
42  *
43  * SHARED is compatible with SHARED, not with DEFERRED or EX.
44  * DEFERRED is compatible with DEFERRED, not with SHARED or EX.
45  */
46 
47 #define LM_ST_UNLOCKED		0
48 #define LM_ST_EXCLUSIVE		1
49 #define LM_ST_DEFERRED		2
50 #define LM_ST_SHARED		3
51 
52 /*
53  * lm_lock() flags
54  *
55  * LM_FLAG_TRY
56  * Don't wait to acquire the lock if it can't be granted immediately.
57  *
58  * LM_FLAG_TRY_1CB
59  * Send one blocking callback if TRY is set and the lock is not granted.
60  *
61  * LM_FLAG_NOEXP
62  * GFS sets this flag on lock requests it makes while doing journal recovery.
63  * These special requests should not be blocked due to the recovery like
64  * ordinary locks would be.
65  *
66  * LM_FLAG_ANY
67  * A SHARED request may also be granted in DEFERRED, or a DEFERRED request may
68  * also be granted in SHARED.  The preferred state is whichever is compatible
69  * with other granted locks, or the specified state if no other locks exist.
70  *
71  * LM_FLAG_NODE_SCOPE
72  * This holder agrees to share the lock within this node. In other words,
73  * the glock is held in EX mode according to DLM, but local holders on the
74  * same node can share it.
75  */
76 
77 #define LM_FLAG_TRY		0x0001
78 #define LM_FLAG_TRY_1CB		0x0002
79 #define LM_FLAG_NOEXP		0x0004
80 #define LM_FLAG_ANY		0x0008
81 #define LM_FLAG_NODE_SCOPE	0x0020
82 #define GL_ASYNC		0x0040
83 #define GL_EXACT		0x0080
84 #define GL_SKIP			0x0100
85 #define GL_NOPID		0x0200
86 #define GL_NOCACHE		0x0400
87 
88 /*
89  * lm_async_cb return flags
90  *
91  * LM_OUT_ST_MASK
92  * Masks the lower two bits of lock state in the returned value.
93  *
94  * LM_OUT_CANCELED
95  * The lock request was canceled.
96  *
97  */
98 
99 #define LM_OUT_ST_MASK		0x00000003
100 #define LM_OUT_CANCELED		0x00000008
101 #define LM_OUT_ERROR		0x00000004
102 
103 /*
104  * lm_recovery_done() messages
105  */
106 
107 #define LM_RD_GAVEUP		308
108 #define LM_RD_SUCCESS		309
109 
110 #define GLR_TRYFAILED		13
111 
112 #define GL_GLOCK_MAX_HOLD        (long)(HZ / 5)
113 #define GL_GLOCK_DFT_HOLD        (long)(HZ / 5)
114 #define GL_GLOCK_MIN_HOLD        (long)(10)
115 #define GL_GLOCK_HOLD_INCR       (long)(HZ / 20)
116 #define GL_GLOCK_HOLD_DECR       (long)(HZ / 40)
117 
118 struct lm_lockops {
119 	const char *lm_proto_name;
120 	int (*lm_mount) (struct gfs2_sbd *sdp, const char *table);
121 	void (*lm_first_done) (struct gfs2_sbd *sdp);
122 	void (*lm_recovery_result) (struct gfs2_sbd *sdp, unsigned int jid,
123 				    unsigned int result);
124 	void (*lm_unmount) (struct gfs2_sbd *sdp);
125 	void (*lm_withdraw) (struct gfs2_sbd *sdp);
126 	void (*lm_put_lock) (struct gfs2_glock *gl);
127 	int (*lm_lock) (struct gfs2_glock *gl, unsigned int req_state,
128 			unsigned int flags);
129 	void (*lm_cancel) (struct gfs2_glock *gl);
130 	const match_table_t *lm_tokens;
131 };
132 
133 struct gfs2_glock_aspace {
134 	struct gfs2_glock glock;
135 	struct address_space mapping;
136 };
137 
gfs2_glock_is_locked_by_me(struct gfs2_glock * gl)138 static 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_lockref.lock);
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;
153 out:
154 	spin_unlock(&gl->gl_lockref.lock);
155 
156 	return gh;
157 }
158 
gfs2_glock_is_held_excl(struct gfs2_glock * gl)159 static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
160 {
161 	return gl->gl_state == LM_ST_EXCLUSIVE;
162 }
163 
gfs2_glock_is_held_dfrd(struct gfs2_glock * gl)164 static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
165 {
166 	return gl->gl_state == LM_ST_DEFERRED;
167 }
168 
gfs2_glock_is_held_shrd(struct gfs2_glock * gl)169 static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
170 {
171 	return gl->gl_state == LM_ST_SHARED;
172 }
173 
gfs2_glock2aspace(struct gfs2_glock * gl)174 static inline struct address_space *gfs2_glock2aspace(struct gfs2_glock *gl)
175 {
176 	if (gl->gl_ops->go_flags & GLOF_ASPACE) {
177 		struct gfs2_glock_aspace *gla =
178 			container_of(gl, struct gfs2_glock_aspace, glock);
179 		return &gla->mapping;
180 	}
181 	return NULL;
182 }
183 
184 extern int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
185 			  const struct gfs2_glock_operations *glops,
186 			  int create, struct gfs2_glock **glp);
187 extern struct gfs2_glock *gfs2_glock_hold(struct gfs2_glock *gl);
188 extern void gfs2_glock_put(struct gfs2_glock *gl);
189 extern void gfs2_glock_queue_put(struct gfs2_glock *gl);
190 
191 extern void __gfs2_holder_init(struct gfs2_glock *gl, unsigned int state,
192 			       u16 flags, struct gfs2_holder *gh,
193 			       unsigned long ip);
gfs2_holder_init(struct gfs2_glock * gl,unsigned int state,u16 flags,struct gfs2_holder * gh)194 static inline void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state,
195 				    u16 flags, struct gfs2_holder *gh) {
196 	__gfs2_holder_init(gl, state, flags, gh, _RET_IP_);
197 }
198 
199 extern void gfs2_holder_reinit(unsigned int state, u16 flags,
200 			       struct gfs2_holder *gh);
201 extern void gfs2_holder_uninit(struct gfs2_holder *gh);
202 extern int gfs2_glock_nq(struct gfs2_holder *gh);
203 extern int gfs2_glock_poll(struct gfs2_holder *gh);
204 extern int gfs2_instantiate(struct gfs2_holder *gh);
205 extern int gfs2_glock_holder_ready(struct gfs2_holder *gh);
206 extern int gfs2_glock_wait(struct gfs2_holder *gh);
207 extern int gfs2_glock_async_wait(unsigned int num_gh, struct gfs2_holder *ghs);
208 extern void gfs2_glock_dq(struct gfs2_holder *gh);
209 extern void gfs2_glock_dq_wait(struct gfs2_holder *gh);
210 extern void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
211 extern int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
212 			     const struct gfs2_glock_operations *glops,
213 			     unsigned int state, u16 flags,
214 			     struct gfs2_holder *gh);
215 extern int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
216 extern void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
217 extern void gfs2_dump_glock(struct seq_file *seq, struct gfs2_glock *gl,
218 			    bool fsid);
219 #define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) {		\
220 			gfs2_dump_glock(NULL, gl, true);	\
221 			BUG(); } } while(0)
222 #define gfs2_glock_assert_warn(gl, x) do { if (unlikely(!(x))) {	\
223 			gfs2_dump_glock(NULL, gl, true);		\
224 			gfs2_assert_warn((gl)->gl_name.ln_sbd, (x)); } } \
225 	while (0)
226 #define gfs2_glock_assert_withdraw(gl, x) do { if (unlikely(!(x))) {	\
227 			gfs2_dump_glock(NULL, gl, true);		\
228 			gfs2_assert_withdraw((gl)->gl_name.ln_sbd, (x)); } } \
229 	while (0)
230 
231 extern __printf(2, 3)
232 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...);
233 
234 /**
235  * gfs2_glock_nq_init - initialize a holder and enqueue it on a glock
236  * @gl: the glock
237  * @state: the state we're requesting
238  * @flags: the modifier flags
239  * @gh: the holder structure
240  *
241  * Returns: 0, GLR_*, or errno
242  */
243 
gfs2_glock_nq_init(struct gfs2_glock * gl,unsigned int state,u16 flags,struct gfs2_holder * gh)244 static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
245 				     unsigned int state, u16 flags,
246 				     struct gfs2_holder *gh)
247 {
248 	int error;
249 
250 	__gfs2_holder_init(gl, state, flags, gh, _RET_IP_);
251 
252 	error = gfs2_glock_nq(gh);
253 	if (error)
254 		gfs2_holder_uninit(gh);
255 
256 	return error;
257 }
258 
259 extern void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state);
260 extern void gfs2_glock_complete(struct gfs2_glock *gl, int ret);
261 extern bool gfs2_queue_try_to_evict(struct gfs2_glock *gl);
262 extern void gfs2_cancel_delete_work(struct gfs2_glock *gl);
263 extern void gfs2_flush_delete_work(struct gfs2_sbd *sdp);
264 extern void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
265 extern void gfs2_gl_dq_holders(struct gfs2_sbd *sdp);
266 extern void gfs2_glock_thaw(struct gfs2_sbd *sdp);
267 extern void gfs2_glock_add_to_lru(struct gfs2_glock *gl);
268 extern void gfs2_glock_free(struct gfs2_glock *gl);
269 
270 extern int __init gfs2_glock_init(void);
271 extern void gfs2_glock_exit(void);
272 
273 extern void gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
274 extern void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
275 extern void gfs2_register_debugfs(void);
276 extern void gfs2_unregister_debugfs(void);
277 
278 extern void glock_set_object(struct gfs2_glock *gl, void *object);
279 extern void glock_clear_object(struct gfs2_glock *gl, void *object);
280 
281 extern const struct lm_lockops gfs2_dlm_ops;
282 
gfs2_holder_mark_uninitialized(struct gfs2_holder * gh)283 static inline void gfs2_holder_mark_uninitialized(struct gfs2_holder *gh)
284 {
285 	gh->gh_gl = NULL;
286 }
287 
gfs2_holder_initialized(struct gfs2_holder * gh)288 static inline bool gfs2_holder_initialized(struct gfs2_holder *gh)
289 {
290 	return gh->gh_gl;
291 }
292 
gfs2_holder_queued(struct gfs2_holder * gh)293 static inline bool gfs2_holder_queued(struct gfs2_holder *gh)
294 {
295 	return !list_empty(&gh->gh_list);
296 }
297 
298 extern void gfs2_inode_remember_delete(struct gfs2_glock *gl, u64 generation);
299 extern bool gfs2_inode_already_deleted(struct gfs2_glock *gl, u64 generation);
300 
301 #endif /* __GLOCK_DOT_H__ */
302