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