xref: /linux/fs/gfs2/glock.h (revision 7f71507851fc7764b36a3221839607d3a45c2025)
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 #define GL_NOBLOCK		0x0800
88 
89 /*
90  * lm_async_cb return flags
91  *
92  * LM_OUT_ST_MASK
93  * Masks the lower two bits of lock state in the returned value.
94  *
95  * LM_OUT_CANCELED
96  * The lock request was canceled.
97  *
98  */
99 
100 #define LM_OUT_ST_MASK		0x00000003
101 #define LM_OUT_CANCELED		0x00000008
102 #define LM_OUT_ERROR		0x00000004
103 
104 /*
105  * lm_recovery_done() messages
106  */
107 
108 #define LM_RD_GAVEUP		308
109 #define LM_RD_SUCCESS		309
110 
111 #define GLR_TRYFAILED		13
112 
113 #define GL_GLOCK_MAX_HOLD        (long)(HZ / 5)
114 #define GL_GLOCK_DFT_HOLD        (long)(HZ / 5)
115 #define GL_GLOCK_MIN_HOLD        (long)(10)
116 #define GL_GLOCK_HOLD_INCR       (long)(HZ / 20)
117 #define GL_GLOCK_HOLD_DECR       (long)(HZ / 40)
118 
119 struct lm_lockops {
120 	const char *lm_proto_name;
121 	int (*lm_mount) (struct gfs2_sbd *sdp, const char *table);
122 	void (*lm_first_done) (struct gfs2_sbd *sdp);
123 	void (*lm_recovery_result) (struct gfs2_sbd *sdp, unsigned int jid,
124 				    unsigned int result);
125 	void (*lm_unmount) (struct gfs2_sbd *sdp);
126 	void (*lm_withdraw) (struct gfs2_sbd *sdp);
127 	void (*lm_put_lock) (struct gfs2_glock *gl);
128 	int (*lm_lock) (struct gfs2_glock *gl, unsigned int req_state,
129 			unsigned int flags);
130 	void (*lm_cancel) (struct gfs2_glock *gl);
131 	const match_table_t *lm_tokens;
132 };
133 
134 struct gfs2_glock_aspace {
135 	struct gfs2_glock glock;
136 	struct address_space mapping;
137 };
138 
139 static 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;
154 out:
155 	spin_unlock(&gl->gl_lockref.lock);
156 
157 	return gh;
158 }
159 
160 static inline struct address_space *gfs2_glock2aspace(struct gfs2_glock *gl)
161 {
162 	if (gl->gl_ops->go_flags & GLOF_ASPACE) {
163 		struct gfs2_glock_aspace *gla =
164 			container_of(gl, struct gfs2_glock_aspace, glock);
165 		return &gla->mapping;
166 	}
167 	return NULL;
168 }
169 
170 int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
171 		   const struct gfs2_glock_operations *glops,
172 		   int create, struct gfs2_glock **glp);
173 struct gfs2_glock *gfs2_glock_hold(struct gfs2_glock *gl);
174 void gfs2_glock_put(struct gfs2_glock *gl);
175 void gfs2_glock_put_async(struct gfs2_glock *gl);
176 
177 void __gfs2_holder_init(struct gfs2_glock *gl, unsigned int state,
178 		        u16 flags, struct gfs2_holder *gh,
179 		        unsigned long ip);
180 static inline void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state,
181 				    u16 flags, struct gfs2_holder *gh) {
182 	__gfs2_holder_init(gl, state, flags, gh, _RET_IP_);
183 }
184 
185 void gfs2_holder_reinit(unsigned int state, u16 flags,
186 		        struct gfs2_holder *gh);
187 void gfs2_holder_uninit(struct gfs2_holder *gh);
188 int gfs2_glock_nq(struct gfs2_holder *gh);
189 int gfs2_glock_poll(struct gfs2_holder *gh);
190 int gfs2_instantiate(struct gfs2_holder *gh);
191 int gfs2_glock_holder_ready(struct gfs2_holder *gh);
192 int gfs2_glock_wait(struct gfs2_holder *gh);
193 int gfs2_glock_async_wait(unsigned int num_gh, struct gfs2_holder *ghs);
194 void gfs2_glock_dq(struct gfs2_holder *gh);
195 void gfs2_glock_dq_wait(struct gfs2_holder *gh);
196 void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
197 int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
198 		      const struct gfs2_glock_operations *glops,
199 		      unsigned int state, u16 flags,
200 		      struct gfs2_holder *gh);
201 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
202 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
203 void gfs2_dump_glock(struct seq_file *seq, struct gfs2_glock *gl,
204 			    bool fsid);
205 #define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) {		\
206 			gfs2_dump_glock(NULL, gl, true);	\
207 			BUG(); } } while(0)
208 #define gfs2_glock_assert_warn(gl, x) do { if (unlikely(!(x))) {	\
209 			gfs2_dump_glock(NULL, gl, true);		\
210 			gfs2_assert_warn((gl)->gl_name.ln_sbd, (x)); } } \
211 	while (0)
212 #define gfs2_glock_assert_withdraw(gl, x) do { if (unlikely(!(x))) {	\
213 			gfs2_dump_glock(NULL, gl, true);		\
214 			gfs2_assert_withdraw((gl)->gl_name.ln_sbd, (x)); } } \
215 	while (0)
216 
217 __printf(2, 3)
218 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...);
219 
220 /**
221  * gfs2_glock_nq_init - initialize a holder and enqueue it on a glock
222  * @gl: the glock
223  * @state: the state we're requesting
224  * @flags: the modifier flags
225  * @gh: the holder structure
226  *
227  * Returns: 0, GLR_*, or errno
228  */
229 
230 static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
231 				     unsigned int state, u16 flags,
232 				     struct gfs2_holder *gh)
233 {
234 	int error;
235 
236 	__gfs2_holder_init(gl, state, flags, gh, _RET_IP_);
237 
238 	error = gfs2_glock_nq(gh);
239 	if (error)
240 		gfs2_holder_uninit(gh);
241 
242 	return error;
243 }
244 
245 void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state);
246 void gfs2_glock_complete(struct gfs2_glock *gl, int ret);
247 bool gfs2_queue_try_to_evict(struct gfs2_glock *gl);
248 bool gfs2_queue_verify_delete(struct gfs2_glock *gl, bool later);
249 void gfs2_cancel_delete_work(struct gfs2_glock *gl);
250 void gfs2_flush_delete_work(struct gfs2_sbd *sdp);
251 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
252 void gfs2_gl_dq_holders(struct gfs2_sbd *sdp);
253 void gfs2_glock_thaw(struct gfs2_sbd *sdp);
254 void gfs2_glock_free(struct gfs2_glock *gl);
255 void gfs2_glock_free_later(struct gfs2_glock *gl);
256 
257 int __init gfs2_glock_init(void);
258 void gfs2_glock_exit(void);
259 
260 void gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
261 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
262 void gfs2_register_debugfs(void);
263 void gfs2_unregister_debugfs(void);
264 
265 void glock_set_object(struct gfs2_glock *gl, void *object);
266 void glock_clear_object(struct gfs2_glock *gl, void *object);
267 
268 extern const struct lm_lockops gfs2_dlm_ops;
269 
270 static inline void gfs2_holder_mark_uninitialized(struct gfs2_holder *gh)
271 {
272 	gh->gh_gl = NULL;
273 }
274 
275 static inline bool gfs2_holder_initialized(struct gfs2_holder *gh)
276 {
277 	return gh->gh_gl;
278 }
279 
280 static inline bool gfs2_holder_queued(struct gfs2_holder *gh)
281 {
282 	return !list_empty(&gh->gh_list);
283 }
284 
285 void gfs2_inode_remember_delete(struct gfs2_glock *gl, u64 generation);
286 bool gfs2_inode_already_deleted(struct gfs2_glock *gl, u64 generation);
287 
288 static inline bool glock_needs_demote(struct gfs2_glock *gl)
289 {
290 	return (test_bit(GLF_DEMOTE, &gl->gl_flags) ||
291 		test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags));
292 }
293 
294 #endif /* __GLOCK_DOT_H__ */
295