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_PRIORITY
72  * Override fairness considerations.  Suppose a lock is held in a shared state
73  * and there is a pending request for the deferred state.  A shared lock
74  * request with the priority flag would be allowed to bypass the deferred
75  * request and directly join the other shared lock.  A shared lock request
76  * without the priority flag might be forced to wait until the deferred
77  * requested had acquired and released the lock.
78  *
79  * LM_FLAG_NODE_SCOPE
80  * This holder agrees to share the lock within this node. In other words,
81  * the glock is held in EX mode according to DLM, but local holders on the
82  * same node can share it.
83  */
84 
85 #define LM_FLAG_TRY		0x0001
86 #define LM_FLAG_TRY_1CB		0x0002
87 #define LM_FLAG_NOEXP		0x0004
88 #define LM_FLAG_ANY		0x0008
89 #define LM_FLAG_PRIORITY	0x0010
90 #define LM_FLAG_NODE_SCOPE	0x0020
91 #define GL_ASYNC		0x0040
92 #define GL_EXACT		0x0080
93 #define GL_SKIP			0x0100
94 #define GL_NOCACHE		0x0400
95 
96 /*
97  * lm_async_cb return flags
98  *
99  * LM_OUT_ST_MASK
100  * Masks the lower two bits of lock state in the returned value.
101  *
102  * LM_OUT_CANCELED
103  * The lock request was canceled.
104  *
105  */
106 
107 #define LM_OUT_ST_MASK		0x00000003
108 #define LM_OUT_CANCELED		0x00000008
109 #define LM_OUT_ERROR		0x00000004
110 
111 /*
112  * lm_recovery_done() messages
113  */
114 
115 #define LM_RD_GAVEUP		308
116 #define LM_RD_SUCCESS		309
117 
118 #define GLR_TRYFAILED		13
119 
120 #define GL_GLOCK_MAX_HOLD        (long)(HZ / 5)
121 #define GL_GLOCK_DFT_HOLD        (long)(HZ / 5)
122 #define GL_GLOCK_MIN_HOLD        (long)(10)
123 #define GL_GLOCK_HOLD_INCR       (long)(HZ / 20)
124 #define GL_GLOCK_HOLD_DECR       (long)(HZ / 40)
125 
126 struct lm_lockops {
127 	const char *lm_proto_name;
128 	int (*lm_mount) (struct gfs2_sbd *sdp, const char *table);
129 	void (*lm_first_done) (struct gfs2_sbd *sdp);
130 	void (*lm_recovery_result) (struct gfs2_sbd *sdp, unsigned int jid,
131 				    unsigned int result);
132 	void (*lm_unmount) (struct gfs2_sbd *sdp);
133 	void (*lm_withdraw) (struct gfs2_sbd *sdp);
134 	void (*lm_put_lock) (struct gfs2_glock *gl);
135 	int (*lm_lock) (struct gfs2_glock *gl, unsigned int req_state,
136 			unsigned int flags);
137 	void (*lm_cancel) (struct gfs2_glock *gl);
138 	const match_table_t *lm_tokens;
139 };
140 
141 extern struct workqueue_struct *gfs2_delete_workqueue;
gfs2_glock_is_locked_by_me(struct gfs2_glock * gl)142 static inline struct gfs2_holder *gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
143 {
144 	struct gfs2_holder *gh;
145 	struct pid *pid;
146 
147 	/* Look in glock's list of holders for one with current task as owner */
148 	spin_lock(&gl->gl_lockref.lock);
149 	pid = task_pid(current);
150 	list_for_each_entry(gh, &gl->gl_holders, gh_list) {
151 		if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
152 			break;
153 		if (test_bit(HIF_MAY_DEMOTE, &gh->gh_iflags))
154 			continue;
155 		if (gh->gh_owner_pid == pid)
156 			goto out;
157 	}
158 	gh = NULL;
159 out:
160 	spin_unlock(&gl->gl_lockref.lock);
161 
162 	return gh;
163 }
164 
gfs2_glock_is_held_excl(struct gfs2_glock * gl)165 static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
166 {
167 	return gl->gl_state == LM_ST_EXCLUSIVE;
168 }
169 
gfs2_glock_is_held_dfrd(struct gfs2_glock * gl)170 static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
171 {
172 	return gl->gl_state == LM_ST_DEFERRED;
173 }
174 
gfs2_glock_is_held_shrd(struct gfs2_glock * gl)175 static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
176 {
177 	return gl->gl_state == LM_ST_SHARED;
178 }
179 
gfs2_glock2aspace(struct gfs2_glock * gl)180 static inline struct address_space *gfs2_glock2aspace(struct gfs2_glock *gl)
181 {
182 	if (gl->gl_ops->go_flags & GLOF_ASPACE)
183 		return (struct address_space *)(gl + 1);
184 	return NULL;
185 }
186 
187 extern int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
188 			  const struct gfs2_glock_operations *glops,
189 			  int create, struct gfs2_glock **glp);
190 extern void gfs2_glock_hold(struct gfs2_glock *gl);
191 extern void gfs2_glock_put(struct gfs2_glock *gl);
192 extern void gfs2_glock_queue_put(struct gfs2_glock *gl);
193 
194 extern void __gfs2_holder_init(struct gfs2_glock *gl, unsigned int state,
195 			       u16 flags, struct gfs2_holder *gh,
196 			       unsigned long ip);
gfs2_holder_init(struct gfs2_glock * gl,unsigned int state,u16 flags,struct gfs2_holder * gh)197 static inline void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state,
198 				    u16 flags, struct gfs2_holder *gh) {
199 	__gfs2_holder_init(gl, state, flags, gh, _RET_IP_);
200 }
201 
202 extern void gfs2_holder_reinit(unsigned int state, u16 flags,
203 			       struct gfs2_holder *gh);
204 extern void gfs2_holder_uninit(struct gfs2_holder *gh);
205 extern int gfs2_glock_nq(struct gfs2_holder *gh);
206 extern int gfs2_glock_poll(struct gfs2_holder *gh);
207 extern int gfs2_instantiate(struct gfs2_holder *gh);
208 extern int gfs2_glock_wait(struct gfs2_holder *gh);
209 extern int gfs2_glock_async_wait(unsigned int num_gh, struct gfs2_holder *ghs);
210 extern void gfs2_glock_dq(struct gfs2_holder *gh);
211 extern void gfs2_glock_dq_wait(struct gfs2_holder *gh);
212 extern void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
213 extern int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
214 			     const struct gfs2_glock_operations *glops,
215 			     unsigned int state, u16 flags,
216 			     struct gfs2_holder *gh);
217 extern int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
218 extern void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
219 extern void gfs2_dump_glock(struct seq_file *seq, struct gfs2_glock *gl,
220 			    bool fsid);
221 #define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) {		\
222 			gfs2_dump_glock(NULL, gl, true);	\
223 			BUG(); } } while(0)
224 #define gfs2_glock_assert_warn(gl, x) do { if (unlikely(!(x))) {	\
225 			gfs2_dump_glock(NULL, gl, true);		\
226 			gfs2_assert_warn((gl)->gl_name.ln_sbd, (x)); } } \
227 	while (0)
228 #define gfs2_glock_assert_withdraw(gl, x) do { if (unlikely(!(x))) {	\
229 			gfs2_dump_glock(NULL, gl, true);		\
230 			gfs2_assert_withdraw((gl)->gl_name.ln_sbd, (x)); } } \
231 	while (0)
232 
233 extern __printf(2, 3)
234 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...);
235 
236 /**
237  * gfs2_glock_nq_init - initialize a holder and enqueue it on a glock
238  * @gl: the glock
239  * @state: the state we're requesting
240  * @flags: the modifier flags
241  * @gh: the holder structure
242  *
243  * Returns: 0, GLR_*, or errno
244  */
245 
gfs2_glock_nq_init(struct gfs2_glock * gl,unsigned int state,u16 flags,struct gfs2_holder * gh)246 static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
247 				     unsigned int state, u16 flags,
248 				     struct gfs2_holder *gh)
249 {
250 	int error;
251 
252 	__gfs2_holder_init(gl, state, flags, gh, _RET_IP_);
253 
254 	error = gfs2_glock_nq(gh);
255 	if (error)
256 		gfs2_holder_uninit(gh);
257 
258 	return error;
259 }
260 
261 extern void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state);
262 extern void gfs2_glock_complete(struct gfs2_glock *gl, int ret);
263 extern bool gfs2_queue_delete_work(struct gfs2_glock *gl, unsigned long delay);
264 extern void gfs2_cancel_delete_work(struct gfs2_glock *gl);
265 extern bool gfs2_delete_work_queued(const struct gfs2_glock *gl);
266 extern void gfs2_flush_delete_work(struct gfs2_sbd *sdp);
267 extern void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
268 extern void gfs2_glock_finish_truncate(struct gfs2_inode *ip);
269 extern void gfs2_glock_thaw(struct gfs2_sbd *sdp);
270 extern void gfs2_glock_add_to_lru(struct gfs2_glock *gl);
271 extern void gfs2_glock_free(struct gfs2_glock *gl);
272 
273 extern int __init gfs2_glock_init(void);
274 extern void gfs2_glock_exit(void);
275 
276 extern void gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
277 extern void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
278 extern void gfs2_register_debugfs(void);
279 extern void gfs2_unregister_debugfs(void);
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 /**
299  * glock_set_object - set the gl_object field of a glock
300  * @gl: the glock
301  * @object: the object
302  */
glock_set_object(struct gfs2_glock * gl,void * object)303 static inline void glock_set_object(struct gfs2_glock *gl, void *object)
304 {
305 	spin_lock(&gl->gl_lockref.lock);
306 	if (gfs2_assert_warn(gl->gl_name.ln_sbd, gl->gl_object == NULL))
307 		gfs2_dump_glock(NULL, gl, true);
308 	gl->gl_object = object;
309 	spin_unlock(&gl->gl_lockref.lock);
310 }
311 
312 /**
313  * glock_clear_object - clear the gl_object field of a glock
314  * @gl: the glock
315  * @object: the object
316  *
317  * I'd love to similarly add this:
318  *	else if (gfs2_assert_warn(gl->gl_sbd, gl->gl_object == object))
319  *		gfs2_dump_glock(NULL, gl, true);
320  * Unfortunately, that's not possible because as soon as gfs2_delete_inode
321  * frees the block in the rgrp, another process can reassign it for an I_NEW
322  * inode in gfs2_create_inode because that calls new_inode, not gfs2_iget.
323  * That means gfs2_delete_inode may subsequently try to call this function
324  * for a glock that's already pointing to a brand new inode. If we clear the
325  * new inode's gl_object, we'll introduce metadata corruption. Function
326  * gfs2_delete_inode calls clear_inode which calls gfs2_clear_inode which also
327  * tries to clear gl_object, so it's more than just gfs2_delete_inode.
328  *
329  */
glock_clear_object(struct gfs2_glock * gl,void * object)330 static inline void glock_clear_object(struct gfs2_glock *gl, void *object)
331 {
332 	spin_lock(&gl->gl_lockref.lock);
333 	if (gl->gl_object == object)
334 		gl->gl_object = NULL;
335 	spin_unlock(&gl->gl_lockref.lock);
336 }
337 
gfs2_holder_allow_demote(struct gfs2_holder * gh)338 static inline void gfs2_holder_allow_demote(struct gfs2_holder *gh)
339 {
340 	struct gfs2_glock *gl = gh->gh_gl;
341 
342 	spin_lock(&gl->gl_lockref.lock);
343 	set_bit(HIF_MAY_DEMOTE, &gh->gh_iflags);
344 	spin_unlock(&gl->gl_lockref.lock);
345 }
346 
gfs2_holder_disallow_demote(struct gfs2_holder * gh)347 static inline void gfs2_holder_disallow_demote(struct gfs2_holder *gh)
348 {
349 	struct gfs2_glock *gl = gh->gh_gl;
350 
351 	spin_lock(&gl->gl_lockref.lock);
352 	clear_bit(HIF_MAY_DEMOTE, &gh->gh_iflags);
353 	spin_unlock(&gl->gl_lockref.lock);
354 }
355 
356 extern void gfs2_inode_remember_delete(struct gfs2_glock *gl, u64 generation);
357 extern bool gfs2_inode_already_deleted(struct gfs2_glock *gl, u64 generation);
358 
359 #endif /* __GLOCK_DOT_H__ */
360