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Linux kernel mirror (for testing)
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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
17enum {
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
120struct 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
135extern struct workqueue_struct *gfs2_delete_workqueue;
136static 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;
151out:
152 spin_unlock(&gl->gl_lockref.lock);
153
154 return gh;
155}
156
157static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
158{
159 return gl->gl_state == LM_ST_EXCLUSIVE;
160}
161
162static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
163{
164 return gl->gl_state == LM_ST_DEFERRED;
165}
166
167static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
168{
169 return gl->gl_state == LM_ST_SHARED;
170}
171
172static 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
179extern int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
180 const struct gfs2_glock_operations *glops,
181 int create, struct gfs2_glock **glp);
182extern void gfs2_glock_hold(struct gfs2_glock *gl);
183extern void gfs2_glock_put(struct gfs2_glock *gl);
184extern void gfs2_glock_queue_put(struct gfs2_glock *gl);
185extern void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state,
186 u16 flags, struct gfs2_holder *gh);
187extern void gfs2_holder_reinit(unsigned int state, u16 flags,
188 struct gfs2_holder *gh);
189extern void gfs2_holder_uninit(struct gfs2_holder *gh);
190extern int gfs2_glock_nq(struct gfs2_holder *gh);
191extern int gfs2_glock_poll(struct gfs2_holder *gh);
192extern int gfs2_glock_wait(struct gfs2_holder *gh);
193extern void gfs2_glock_dq(struct gfs2_holder *gh);
194extern void gfs2_glock_dq_wait(struct gfs2_holder *gh);
195extern void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
196extern int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
197 const struct gfs2_glock_operations *glops,
198 unsigned int state, u16 flags,
199 struct gfs2_holder *gh);
200extern int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
201extern void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
202extern void gfs2_dump_glock(struct seq_file *seq, struct gfs2_glock *gl);
203#define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) { gfs2_dump_glock(NULL, gl); BUG(); } } while(0)
204extern __printf(2, 3)
205void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...);
206
207/**
208 * gfs2_glock_nq_init - initialize a holder and enqueue it on a glock
209 * @gl: the glock
210 * @state: the state we're requesting
211 * @flags: the modifier flags
212 * @gh: the holder structure
213 *
214 * Returns: 0, GLR_*, or errno
215 */
216
217static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
218 unsigned int state, u16 flags,
219 struct gfs2_holder *gh)
220{
221 int error;
222
223 gfs2_holder_init(gl, state, flags, gh);
224
225 error = gfs2_glock_nq(gh);
226 if (error)
227 gfs2_holder_uninit(gh);
228
229 return error;
230}
231
232extern void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state);
233extern void gfs2_glock_complete(struct gfs2_glock *gl, int ret);
234extern void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
235extern void gfs2_glock_finish_truncate(struct gfs2_inode *ip);
236extern void gfs2_glock_thaw(struct gfs2_sbd *sdp);
237extern void gfs2_glock_add_to_lru(struct gfs2_glock *gl);
238extern void gfs2_glock_free(struct gfs2_glock *gl);
239
240extern int __init gfs2_glock_init(void);
241extern void gfs2_glock_exit(void);
242
243extern void gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
244extern void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
245extern void gfs2_register_debugfs(void);
246extern void gfs2_unregister_debugfs(void);
247
248extern const struct lm_lockops gfs2_dlm_ops;
249
250static inline void gfs2_holder_mark_uninitialized(struct gfs2_holder *gh)
251{
252 gh->gh_gl = NULL;
253}
254
255static inline bool gfs2_holder_initialized(struct gfs2_holder *gh)
256{
257 return gh->gh_gl;
258}
259
260/**
261 * glock_set_object - set the gl_object field of a glock
262 * @gl: the glock
263 * @object: the object
264 */
265static inline void glock_set_object(struct gfs2_glock *gl, void *object)
266{
267 spin_lock(&gl->gl_lockref.lock);
268 if (gfs2_assert_warn(gl->gl_name.ln_sbd, gl->gl_object == NULL))
269 gfs2_dump_glock(NULL, gl);
270 gl->gl_object = object;
271 spin_unlock(&gl->gl_lockref.lock);
272}
273
274/**
275 * glock_clear_object - clear the gl_object field of a glock
276 * @gl: the glock
277 * @object: the object
278 *
279 * I'd love to similarly add this:
280 * else if (gfs2_assert_warn(gl->gl_sbd, gl->gl_object == object))
281 * gfs2_dump_glock(NULL, gl);
282 * Unfortunately, that's not possible because as soon as gfs2_delete_inode
283 * frees the block in the rgrp, another process can reassign it for an I_NEW
284 * inode in gfs2_create_inode because that calls new_inode, not gfs2_iget.
285 * That means gfs2_delete_inode may subsequently try to call this function
286 * for a glock that's already pointing to a brand new inode. If we clear the
287 * new inode's gl_object, we'll introduce metadata corruption. Function
288 * gfs2_delete_inode calls clear_inode which calls gfs2_clear_inode which also
289 * tries to clear gl_object, so it's more than just gfs2_delete_inode.
290 *
291 */
292static inline void glock_clear_object(struct gfs2_glock *gl, void *object)
293{
294 spin_lock(&gl->gl_lockref.lock);
295 if (gl->gl_object == object)
296 gl->gl_object = NULL;
297 spin_unlock(&gl->gl_lockref.lock);
298}
299
300#endif /* __GLOCK_DOT_H__ */