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 extern __printf(2, 3)
209 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...);
210
211 /**
212 * gfs2_glock_nq_init - initialize a holder and enqueue it on a glock
213 * @gl: the glock
214 * @state: the state we're requesting
215 * @flags: the modifier flags
216 * @gh: the holder structure
217 *
218 * Returns: 0, GLR_*, or errno
219 */
220
gfs2_glock_nq_init(struct gfs2_glock * gl,unsigned int state,u16 flags,struct gfs2_holder * gh)221 static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
222 unsigned int state, u16 flags,
223 struct gfs2_holder *gh)
224 {
225 int error;
226
227 gfs2_holder_init(gl, state, flags, gh);
228
229 error = gfs2_glock_nq(gh);
230 if (error)
231 gfs2_holder_uninit(gh);
232
233 return error;
234 }
235
236 extern void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state);
237 extern void gfs2_glock_complete(struct gfs2_glock *gl, int ret);
238 extern void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
239 extern void gfs2_glock_finish_truncate(struct gfs2_inode *ip);
240 extern void gfs2_glock_thaw(struct gfs2_sbd *sdp);
241 extern void gfs2_glock_add_to_lru(struct gfs2_glock *gl);
242 extern void gfs2_glock_free(struct gfs2_glock *gl);
243
244 extern int __init gfs2_glock_init(void);
245 extern void gfs2_glock_exit(void);
246
247 extern void gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
248 extern void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
249 extern void gfs2_register_debugfs(void);
250 extern void gfs2_unregister_debugfs(void);
251
252 extern const struct lm_lockops gfs2_dlm_ops;
253
gfs2_holder_mark_uninitialized(struct gfs2_holder * gh)254 static inline void gfs2_holder_mark_uninitialized(struct gfs2_holder *gh)
255 {
256 gh->gh_gl = NULL;
257 }
258
gfs2_holder_initialized(struct gfs2_holder * gh)259 static inline bool gfs2_holder_initialized(struct gfs2_holder *gh)
260 {
261 return gh->gh_gl;
262 }
263
gfs2_holder_queued(struct gfs2_holder * gh)264 static inline bool gfs2_holder_queued(struct gfs2_holder *gh)
265 {
266 return !list_empty(&gh->gh_list);
267 }
268
269 /**
270 * glock_set_object - set the gl_object field of a glock
271 * @gl: the glock
272 * @object: the object
273 */
glock_set_object(struct gfs2_glock * gl,void * object)274 static inline void glock_set_object(struct gfs2_glock *gl, void *object)
275 {
276 spin_lock(&gl->gl_lockref.lock);
277 if (gfs2_assert_warn(gl->gl_name.ln_sbd, gl->gl_object == NULL))
278 gfs2_dump_glock(NULL, gl, true);
279 gl->gl_object = object;
280 spin_unlock(&gl->gl_lockref.lock);
281 }
282
283 /**
284 * glock_clear_object - clear the gl_object field of a glock
285 * @gl: the glock
286 * @object: the object
287 *
288 * I'd love to similarly add this:
289 * else if (gfs2_assert_warn(gl->gl_sbd, gl->gl_object == object))
290 * gfs2_dump_glock(NULL, gl, true);
291 * Unfortunately, that's not possible because as soon as gfs2_delete_inode
292 * frees the block in the rgrp, another process can reassign it for an I_NEW
293 * inode in gfs2_create_inode because that calls new_inode, not gfs2_iget.
294 * That means gfs2_delete_inode may subsequently try to call this function
295 * for a glock that's already pointing to a brand new inode. If we clear the
296 * new inode's gl_object, we'll introduce metadata corruption. Function
297 * gfs2_delete_inode calls clear_inode which calls gfs2_clear_inode which also
298 * tries to clear gl_object, so it's more than just gfs2_delete_inode.
299 *
300 */
glock_clear_object(struct gfs2_glock * gl,void * object)301 static inline void glock_clear_object(struct gfs2_glock *gl, void *object)
302 {
303 spin_lock(&gl->gl_lockref.lock);
304 if (gl->gl_object == object)
305 gl->gl_object = NULL;
306 spin_unlock(&gl->gl_lockref.lock);
307 }
308
309 #endif /* __GLOCK_DOT_H__ */
310