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
80 #define LM_FLAG_TRY 0x0001
81 #define LM_FLAG_TRY_1CB 0x0002
82 #define LM_FLAG_NOEXP 0x0004
83 #define LM_FLAG_ANY 0x0008
84 #define LM_FLAG_PRIORITY 0x0010
85 #define GL_ASYNC 0x0040
86 #define GL_EXACT 0x0080
87 #define GL_SKIP 0x0100
88 #define GL_NOCACHE 0x0400
89
90 /*
91 * lm_async_cb return flags
92 *
93 * LM_OUT_ST_MASK
94 * Masks the lower two bits of lock state in the returned value.
95 *
96 * LM_OUT_CANCELED
97 * The lock request was canceled.
98 *
99 */
100
101 #define LM_OUT_ST_MASK 0x00000003
102 #define LM_OUT_CANCELED 0x00000008
103 #define LM_OUT_ERROR 0x00000004
104
105 /*
106 * lm_recovery_done() messages
107 */
108
109 #define LM_RD_GAVEUP 308
110 #define LM_RD_SUCCESS 309
111
112 #define GLR_TRYFAILED 13
113
114 #define GL_GLOCK_MAX_HOLD (long)(HZ / 5)
115 #define GL_GLOCK_DFT_HOLD (long)(HZ / 5)
116 #define GL_GLOCK_MIN_HOLD (long)(10)
117 #define GL_GLOCK_HOLD_INCR (long)(HZ / 20)
118 #define GL_GLOCK_HOLD_DECR (long)(HZ / 40)
119
120 struct lm_lockops {
121 const char *lm_proto_name;
122 int (*lm_mount) (struct gfs2_sbd *sdp, const char *table);
123 void (*lm_first_done) (struct gfs2_sbd *sdp);
124 void (*lm_recovery_result) (struct gfs2_sbd *sdp, unsigned int jid,
125 unsigned int result);
126 void (*lm_unmount) (struct gfs2_sbd *sdp);
127 void (*lm_withdraw) (struct gfs2_sbd *sdp);
128 void (*lm_put_lock) (struct gfs2_glock *gl);
129 int (*lm_lock) (struct gfs2_glock *gl, unsigned int req_state,
130 unsigned int flags);
131 void (*lm_cancel) (struct gfs2_glock *gl);
132 const match_table_t *lm_tokens;
133 };
134
135 extern struct workqueue_struct *gfs2_delete_workqueue;
gfs2_glock_is_locked_by_me(struct gfs2_glock * gl)136 static inline struct gfs2_holder *gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
137 {
138 struct gfs2_holder *gh;
139 struct pid *pid;
140
141 /* Look in glock's list of holders for one with current task as owner */
142 spin_lock(&gl->gl_lockref.lock);
143 pid = task_pid(current);
144 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
145 if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
146 break;
147 if (gh->gh_owner_pid == pid)
148 goto out;
149 }
150 gh = NULL;
151 out:
152 spin_unlock(&gl->gl_lockref.lock);
153
154 return gh;
155 }
156
gfs2_glock_is_held_excl(struct gfs2_glock * gl)157 static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
158 {
159 return gl->gl_state == LM_ST_EXCLUSIVE;
160 }
161
gfs2_glock_is_held_dfrd(struct gfs2_glock * gl)162 static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
163 {
164 return gl->gl_state == LM_ST_DEFERRED;
165 }
166
gfs2_glock_is_held_shrd(struct gfs2_glock * gl)167 static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
168 {
169 return gl->gl_state == LM_ST_SHARED;
170 }
171
gfs2_glock2aspace(struct gfs2_glock * gl)172 static inline struct address_space *gfs2_glock2aspace(struct gfs2_glock *gl)
173 {
174 if (gl->gl_ops->go_flags & GLOF_ASPACE)
175 return (struct address_space *)(gl + 1);
176 return NULL;
177 }
178
179 extern int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
180 const struct gfs2_glock_operations *glops,
181 int create, struct gfs2_glock **glp);
182 extern void gfs2_glock_hold(struct gfs2_glock *gl);
183 extern void gfs2_glock_put(struct gfs2_glock *gl);
184 extern void gfs2_glock_queue_put(struct gfs2_glock *gl);
185 extern void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state,
186 u16 flags, struct gfs2_holder *gh);
187 extern void gfs2_holder_reinit(unsigned int state, u16 flags,
188 struct gfs2_holder *gh);
189 extern void gfs2_holder_uninit(struct gfs2_holder *gh);
190 extern int gfs2_glock_nq(struct gfs2_holder *gh);
191 extern int gfs2_glock_poll(struct gfs2_holder *gh);
192 extern int gfs2_glock_wait(struct gfs2_holder *gh);
193 extern int gfs2_glock_async_wait(unsigned int num_gh, struct gfs2_holder *ghs);
194 extern void gfs2_glock_dq(struct gfs2_holder *gh);
195 extern void gfs2_glock_dq_wait(struct gfs2_holder *gh);
196 extern void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
197 extern 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 extern int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
202 extern void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
203 extern 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 extern __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
gfs2_glock_nq_init(struct gfs2_glock * gl,unsigned int state,u16 flags,struct gfs2_holder * gh)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);
237
238 error = gfs2_glock_nq(gh);
239 if (error)
240 gfs2_holder_uninit(gh);
241
242 return error;
243 }
244
245 extern void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state);
246 extern void gfs2_glock_complete(struct gfs2_glock *gl, int ret);
247 extern bool gfs2_queue_delete_work(struct gfs2_glock *gl, unsigned long delay);
248 extern void gfs2_cancel_delete_work(struct gfs2_glock *gl);
249 extern bool gfs2_delete_work_queued(const struct gfs2_glock *gl);
250 extern void gfs2_flush_delete_work(struct gfs2_sbd *sdp);
251 extern void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
252 extern void gfs2_glock_finish_truncate(struct gfs2_inode *ip);
253 extern void gfs2_glock_thaw(struct gfs2_sbd *sdp);
254 extern void gfs2_glock_add_to_lru(struct gfs2_glock *gl);
255 extern void gfs2_glock_free(struct gfs2_glock *gl);
256
257 extern int __init gfs2_glock_init(void);
258 extern void gfs2_glock_exit(void);
259
260 extern void gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
261 extern void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
262 extern void gfs2_register_debugfs(void);
263 extern void gfs2_unregister_debugfs(void);
264
265 extern const struct lm_lockops gfs2_dlm_ops;
266
gfs2_holder_mark_uninitialized(struct gfs2_holder * gh)267 static inline void gfs2_holder_mark_uninitialized(struct gfs2_holder *gh)
268 {
269 gh->gh_gl = NULL;
270 }
271
gfs2_holder_initialized(struct gfs2_holder * gh)272 static inline bool gfs2_holder_initialized(struct gfs2_holder *gh)
273 {
274 return gh->gh_gl;
275 }
276
gfs2_holder_queued(struct gfs2_holder * gh)277 static inline bool gfs2_holder_queued(struct gfs2_holder *gh)
278 {
279 return !list_empty(&gh->gh_list);
280 }
281
282 /**
283 * glock_set_object - set the gl_object field of a glock
284 * @gl: the glock
285 * @object: the object
286 */
glock_set_object(struct gfs2_glock * gl,void * object)287 static inline void glock_set_object(struct gfs2_glock *gl, void *object)
288 {
289 spin_lock(&gl->gl_lockref.lock);
290 if (gfs2_assert_warn(gl->gl_name.ln_sbd, gl->gl_object == NULL))
291 gfs2_dump_glock(NULL, gl, true);
292 gl->gl_object = object;
293 spin_unlock(&gl->gl_lockref.lock);
294 }
295
296 /**
297 * glock_clear_object - clear the gl_object field of a glock
298 * @gl: the glock
299 * @object: the object
300 *
301 * I'd love to similarly add this:
302 * else if (gfs2_assert_warn(gl->gl_sbd, gl->gl_object == object))
303 * gfs2_dump_glock(NULL, gl, true);
304 * Unfortunately, that's not possible because as soon as gfs2_delete_inode
305 * frees the block in the rgrp, another process can reassign it for an I_NEW
306 * inode in gfs2_create_inode because that calls new_inode, not gfs2_iget.
307 * That means gfs2_delete_inode may subsequently try to call this function
308 * for a glock that's already pointing to a brand new inode. If we clear the
309 * new inode's gl_object, we'll introduce metadata corruption. Function
310 * gfs2_delete_inode calls clear_inode which calls gfs2_clear_inode which also
311 * tries to clear gl_object, so it's more than just gfs2_delete_inode.
312 *
313 */
glock_clear_object(struct gfs2_glock * gl,void * object)314 static inline void glock_clear_object(struct gfs2_glock *gl, void *object)
315 {
316 spin_lock(&gl->gl_lockref.lock);
317 if (gl->gl_object == object)
318 gl->gl_object = NULL;
319 spin_unlock(&gl->gl_lockref.lock);
320 }
321
322 extern void gfs2_inode_remember_delete(struct gfs2_glock *gl, u64 generation);
323 extern bool gfs2_inode_already_deleted(struct gfs2_glock *gl, u64 generation);
324
325 #endif /* __GLOCK_DOT_H__ */
326