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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 * 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
126struct 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
141extern struct workqueue_struct *gfs2_delete_workqueue;
142static 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 (gh->gh_owner_pid == pid)
154 goto out;
155 }
156 gh = NULL;
157out:
158 spin_unlock(&gl->gl_lockref.lock);
159
160 return gh;
161}
162
163static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
164{
165 return gl->gl_state == LM_ST_EXCLUSIVE;
166}
167
168static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
169{
170 return gl->gl_state == LM_ST_DEFERRED;
171}
172
173static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
174{
175 return gl->gl_state == LM_ST_SHARED;
176}
177
178static inline struct address_space *gfs2_glock2aspace(struct gfs2_glock *gl)
179{
180 if (gl->gl_ops->go_flags & GLOF_ASPACE)
181 return (struct address_space *)(gl + 1);
182 return NULL;
183}
184
185extern int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
186 const struct gfs2_glock_operations *glops,
187 int create, struct gfs2_glock **glp);
188extern void gfs2_glock_hold(struct gfs2_glock *gl);
189extern void gfs2_glock_put(struct gfs2_glock *gl);
190extern void gfs2_glock_queue_put(struct gfs2_glock *gl);
191extern void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state,
192 u16 flags, struct gfs2_holder *gh);
193extern void gfs2_holder_reinit(unsigned int state, u16 flags,
194 struct gfs2_holder *gh);
195extern void gfs2_holder_uninit(struct gfs2_holder *gh);
196extern int gfs2_glock_nq(struct gfs2_holder *gh);
197extern int gfs2_glock_poll(struct gfs2_holder *gh);
198extern int gfs2_glock_wait(struct gfs2_holder *gh);
199extern int gfs2_glock_async_wait(unsigned int num_gh, struct gfs2_holder *ghs);
200extern void gfs2_glock_dq(struct gfs2_holder *gh);
201extern void gfs2_glock_dq_wait(struct gfs2_holder *gh);
202extern void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
203extern int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
204 const struct gfs2_glock_operations *glops,
205 unsigned int state, u16 flags,
206 struct gfs2_holder *gh);
207extern int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
208extern void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
209extern void gfs2_dump_glock(struct seq_file *seq, struct gfs2_glock *gl,
210 bool fsid);
211#define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) { \
212 gfs2_dump_glock(NULL, gl, true); \
213 BUG(); } } while(0)
214#define gfs2_glock_assert_warn(gl, x) do { if (unlikely(!(x))) { \
215 gfs2_dump_glock(NULL, gl, true); \
216 gfs2_assert_warn((gl)->gl_name.ln_sbd, (x)); } } \
217 while (0)
218#define gfs2_glock_assert_withdraw(gl, x) do { if (unlikely(!(x))) { \
219 gfs2_dump_glock(NULL, gl, true); \
220 gfs2_assert_withdraw((gl)->gl_name.ln_sbd, (x)); } } \
221 while (0)
222
223extern __printf(2, 3)
224void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...);
225
226/**
227 * gfs2_glock_nq_init - initialize a holder and enqueue it on a glock
228 * @gl: the glock
229 * @state: the state we're requesting
230 * @flags: the modifier flags
231 * @gh: the holder structure
232 *
233 * Returns: 0, GLR_*, or errno
234 */
235
236static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
237 unsigned int state, u16 flags,
238 struct gfs2_holder *gh)
239{
240 int error;
241
242 gfs2_holder_init(gl, state, flags, gh);
243
244 error = gfs2_glock_nq(gh);
245 if (error)
246 gfs2_holder_uninit(gh);
247
248 return error;
249}
250
251extern void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state);
252extern void gfs2_glock_complete(struct gfs2_glock *gl, int ret);
253extern bool gfs2_queue_delete_work(struct gfs2_glock *gl, unsigned long delay);
254extern void gfs2_cancel_delete_work(struct gfs2_glock *gl);
255extern bool gfs2_delete_work_queued(const struct gfs2_glock *gl);
256extern void gfs2_flush_delete_work(struct gfs2_sbd *sdp);
257extern void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
258extern void gfs2_glock_finish_truncate(struct gfs2_inode *ip);
259extern void gfs2_glock_thaw(struct gfs2_sbd *sdp);
260extern void gfs2_glock_add_to_lru(struct gfs2_glock *gl);
261extern void gfs2_glock_free(struct gfs2_glock *gl);
262
263extern int __init gfs2_glock_init(void);
264extern void gfs2_glock_exit(void);
265
266extern void gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
267extern void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
268extern void gfs2_register_debugfs(void);
269extern void gfs2_unregister_debugfs(void);
270
271extern const struct lm_lockops gfs2_dlm_ops;
272
273static inline void gfs2_holder_mark_uninitialized(struct gfs2_holder *gh)
274{
275 gh->gh_gl = NULL;
276}
277
278static inline bool gfs2_holder_initialized(struct gfs2_holder *gh)
279{
280 return gh->gh_gl;
281}
282
283static inline bool gfs2_holder_queued(struct gfs2_holder *gh)
284{
285 return !list_empty(&gh->gh_list);
286}
287
288/**
289 * glock_set_object - set the gl_object field of a glock
290 * @gl: the glock
291 * @object: the object
292 */
293static inline void glock_set_object(struct gfs2_glock *gl, void *object)
294{
295 spin_lock(&gl->gl_lockref.lock);
296 if (gfs2_assert_warn(gl->gl_name.ln_sbd, gl->gl_object == NULL))
297 gfs2_dump_glock(NULL, gl, true);
298 gl->gl_object = object;
299 spin_unlock(&gl->gl_lockref.lock);
300}
301
302/**
303 * glock_clear_object - clear the gl_object field of a glock
304 * @gl: the glock
305 * @object: the object
306 *
307 * I'd love to similarly add this:
308 * else if (gfs2_assert_warn(gl->gl_sbd, gl->gl_object == object))
309 * gfs2_dump_glock(NULL, gl, true);
310 * Unfortunately, that's not possible because as soon as gfs2_delete_inode
311 * frees the block in the rgrp, another process can reassign it for an I_NEW
312 * inode in gfs2_create_inode because that calls new_inode, not gfs2_iget.
313 * That means gfs2_delete_inode may subsequently try to call this function
314 * for a glock that's already pointing to a brand new inode. If we clear the
315 * new inode's gl_object, we'll introduce metadata corruption. Function
316 * gfs2_delete_inode calls clear_inode which calls gfs2_clear_inode which also
317 * tries to clear gl_object, so it's more than just gfs2_delete_inode.
318 *
319 */
320static inline void glock_clear_object(struct gfs2_glock *gl, void *object)
321{
322 spin_lock(&gl->gl_lockref.lock);
323 if (gl->gl_object == object)
324 gl->gl_object = NULL;
325 spin_unlock(&gl->gl_lockref.lock);
326}
327
328extern void gfs2_inode_remember_delete(struct gfs2_glock *gl, u64 generation);
329extern bool gfs2_inode_already_deleted(struct gfs2_glock *gl, u64 generation);
330
331#endif /* __GLOCK_DOT_H__ */