glock.h

  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_RECOVER
 62 * GFS sets this flag on lock requests it makes while doing journal recovery.
 63 * While ordinary requests are blocked until the end of recovery, requests
 64 * with this flag set do proceed.
 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 * In addition, when a lock is already held in EX mode locally, a SHARED or
 72 * DEFERRED mode request with the LM_FLAG_ANY flag set will be granted.
 73 * (The LM_FLAG_ANY flag is only use for SHARED mode requests currently.)
 74 *
 75 * LM_FLAG_NODE_SCOPE
 76 * This holder agrees to share the lock within this node. In other words,
 77 * the glock is held in EX mode according to DLM, but local holders on the
 78 * same node can share it.
 79 */
 80
 81#define LM_FLAG_TRY		0x0001
 82#define LM_FLAG_TRY_1CB		0x0002
 83#define LM_FLAG_RECOVER		0x0004
 84#define LM_FLAG_ANY		0x0008
 85#define LM_FLAG_NODE_SCOPE	0x0020
 86#define GL_ASYNC		0x0040
 87#define GL_EXACT		0x0080
 88#define GL_SKIP			0x0100
 89#define GL_NOPID		0x0200
 90#define GL_NOCACHE		0x0400
 91#define GL_NOBLOCK		0x0800
 92  
 93/*
 94 * lm_async_cb return flags
 95 *
 96 * LM_OUT_ST_MASK
 97 * Masks the lower two bits of lock state in the returned value.
 98 *
 99 * LM_OUT_TRY_AGAIN
100 * The trylock request failed.
101 *
102 * LM_OUT_DEADLOCK
103 * The lock request failed because it would deadlock.
104 *
105 * LM_OUT_CANCELED
106 * The lock request was canceled.
107 *
108 * LM_OUT_ERROR
109 * The lock request timed out or failed.
110 */
111
112#define LM_OUT_ST_MASK		0x00000003
113#define LM_OUT_TRY_AGAIN	0x00000020
114#define LM_OUT_DEADLOCK		0x00000010
115#define LM_OUT_CANCELED		0x00000008
116#define LM_OUT_ERROR		0x00000004
117
118/*
119 * lm_recovery_done() messages
120 */
121
122#define LM_RD_GAVEUP		308
123#define LM_RD_SUCCESS		309
124
125#define GLR_TRYFAILED		13
126
127#define GL_GLOCK_MAX_HOLD        (long)(HZ / 5)
128#define GL_GLOCK_DFT_HOLD        (long)(HZ / 5)
129#define GL_GLOCK_MIN_HOLD        (long)(10)
130#define GL_GLOCK_HOLD_INCR       (long)(HZ / 20)
131#define GL_GLOCK_HOLD_DECR       (long)(HZ / 40)
132
133struct lm_lockops {
134	const char *lm_proto_name;
135	int (*lm_mount) (struct gfs2_sbd *sdp, const char *table);
136	void (*lm_first_done) (struct gfs2_sbd *sdp);
137	void (*lm_recovery_result) (struct gfs2_sbd *sdp, unsigned int jid,
138				    unsigned int result);
139	void (*lm_unmount) (struct gfs2_sbd *sdp, bool clean);
140	void (*lm_withdraw) (struct gfs2_sbd *sdp);
141	void (*lm_put_lock) (struct gfs2_glock *gl);
142	int (*lm_lock) (struct gfs2_glock *gl, unsigned int req_state,
143			unsigned int flags);
144	void (*lm_cancel) (struct gfs2_glock *gl);
145	const match_table_t *lm_tokens;
146};
147
148struct gfs2_glock_aspace {
149	struct gfs2_glock glock;
150	struct address_space mapping;
151};
152
153static inline struct gfs2_holder *gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
154{
155	struct gfs2_holder *gh;
156	struct pid *pid;
157
158	/* Look in glock's list of holders for one with current task as owner */
159	spin_lock(&gl->gl_lockref.lock);
160	pid = task_pid(current);
161	list_for_each_entry(gh, &gl->gl_holders, gh_list) {
162		if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
163			break;
164		if (gh->gh_owner_pid == pid)
165			goto out;
166	}
167	gh = NULL;
168out:
169	spin_unlock(&gl->gl_lockref.lock);
170
171	return gh;
172}
173
174static inline struct address_space *gfs2_glock2aspace(struct gfs2_glock *gl)
175{
176	if (gl->gl_ops->go_flags & GLOF_ASPACE) {
177		struct gfs2_glock_aspace *gla =
178			container_of(gl, struct gfs2_glock_aspace, glock);
179		return &gla->mapping;
180	}
181	return NULL;
182}
183
184int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
185		   const struct gfs2_glock_operations *glops,
186		   int create, struct gfs2_glock **glp);
187struct gfs2_glock *gfs2_glock_hold(struct gfs2_glock *gl);
188void gfs2_glock_put(struct gfs2_glock *gl);
189void gfs2_glock_put_async(struct gfs2_glock *gl);
190
191void __gfs2_holder_init(struct gfs2_glock *gl, unsigned int state,
192		        u16 flags, struct gfs2_holder *gh,
193		        unsigned long ip);
194static inline void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state,
195				    u16 flags, struct gfs2_holder *gh) {
196	__gfs2_holder_init(gl, state, flags, gh, _RET_IP_);
197}
198
199void gfs2_holder_reinit(unsigned int state, u16 flags,
200		        struct gfs2_holder *gh);
201void gfs2_holder_uninit(struct gfs2_holder *gh);
202int gfs2_glock_nq(struct gfs2_holder *gh);
203int gfs2_glock_poll(struct gfs2_holder *gh);
204int gfs2_instantiate(struct gfs2_holder *gh);
205int gfs2_glock_holder_ready(struct gfs2_holder *gh);
206int gfs2_glock_wait(struct gfs2_holder *gh);
207int gfs2_glock_async_wait(unsigned int num_gh, struct gfs2_holder *ghs,
208			  unsigned int retries);
209void gfs2_glock_dq(struct gfs2_holder *gh);
210void gfs2_glock_dq_wait(struct gfs2_holder *gh);
211void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
212int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
213		      const struct gfs2_glock_operations *glops,
214		      unsigned int state, u16 flags,
215		      struct gfs2_holder *gh);
216int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
217void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
218void gfs2_dump_glock(struct seq_file *seq, struct gfs2_glock *gl,
219			    bool fsid);
220#define GLOCK_BUG_ON(gl,x) do { if (unlikely(x)) {		\
221			gfs2_dump_glock(NULL, gl, true);	\
222			BUG(); } } while(0)
223#define gfs2_glock_assert_warn(gl, x) do { if (unlikely(!(x))) {	\
224			gfs2_dump_glock(NULL, gl, true);		\
225			gfs2_assert_warn((gl)->gl_name.ln_sbd, (x)); } } \
226	while (0)
227#define gfs2_glock_assert_withdraw(gl, x) do { if (unlikely(!(x))) {	\
228			gfs2_dump_glock(NULL, gl, true);		\
229			gfs2_assert_withdraw((gl)->gl_name.ln_sbd, (x)); } } \
230	while (0)
231
232__printf(2, 3)
233void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...);
234
235/**
236 * gfs2_glock_nq_init - initialize a holder and enqueue it on a glock
237 * @gl: the glock
238 * @state: the state we're requesting
239 * @flags: the modifier flags
240 * @gh: the holder structure
241 *
242 * Returns: 0, GLR_*, or errno
243 */
244
245static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
246				     unsigned int state, u16 flags,
247				     struct gfs2_holder *gh)
248{
249	int error;
250
251	__gfs2_holder_init(gl, state, flags, gh, _RET_IP_);
252
253	error = gfs2_glock_nq(gh);
254	if (error)
255		gfs2_holder_uninit(gh);
256
257	return error;
258}
259
260void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state);
261void gfs2_glock_complete(struct gfs2_glock *gl, int ret);
262bool gfs2_queue_try_to_evict(struct gfs2_glock *gl);
263bool gfs2_queue_verify_delete(struct gfs2_glock *gl, bool later);
264void gfs2_cancel_delete_work(struct gfs2_glock *gl);
265void gfs2_flush_delete_work(struct gfs2_sbd *sdp);
266void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
267void gfs2_withdraw_glocks(struct gfs2_sbd *sdp);
268void gfs2_glock_thaw(struct gfs2_sbd *sdp);
269void gfs2_glock_free(struct gfs2_glock *gl);
270void gfs2_glock_free_later(struct gfs2_glock *gl);
271
272int __init gfs2_glock_init(void);
273void gfs2_glock_exit(void);
274
275void gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
276void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
277void gfs2_register_debugfs(void);
278void gfs2_unregister_debugfs(void);
279
280void glock_set_object(struct gfs2_glock *gl, void *object);
281void glock_clear_object(struct gfs2_glock *gl, void *object);
282
283extern const struct lm_lockops gfs2_dlm_ops;
284
285static inline void gfs2_holder_mark_uninitialized(struct gfs2_holder *gh)
286{
287	gh->gh_gl = NULL;
288}
289
290static inline bool gfs2_holder_initialized(struct gfs2_holder *gh)
291{
292	return gh->gh_gl;
293}
294
295static inline bool gfs2_holder_queued(struct gfs2_holder *gh)
296{
297	return !list_empty(&gh->gh_list);
298}
299
300void gfs2_inode_remember_delete(struct gfs2_glock *gl, u64 generation);
301bool gfs2_inode_already_deleted(struct gfs2_glock *gl, u64 generation);
302
303static inline bool glock_needs_demote(struct gfs2_glock *gl)
304{
305	return (test_bit(GLF_DEMOTE, &gl->gl_flags) ||
306		test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags));
307}
308
309#endif /* __GLOCK_DOT_H__ */