xref: /linux/fs/gfs2/glock.h (revision 8fa5723aa7e053d498336b48448b292fc2e0458b)
1 /*
2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
3  * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
4  *
5  * This copyrighted material is made available to anyone wishing to use,
6  * modify, copy, or redistribute it subject to the terms and conditions
7  * of the GNU General Public License version 2.
8  */
9 
10 #ifndef __GLOCK_DOT_H__
11 #define __GLOCK_DOT_H__
12 
13 #include <linux/sched.h>
14 #include "incore.h"
15 
16 /* Flags for lock requests; used in gfs2_holder gh_flag field.
17    From lm_interface.h:
18 #define LM_FLAG_TRY		0x00000001
19 #define LM_FLAG_TRY_1CB		0x00000002
20 #define LM_FLAG_NOEXP		0x00000004
21 #define LM_FLAG_ANY		0x00000008
22 #define LM_FLAG_PRIORITY	0x00000010 */
23 
24 #define GL_ASYNC		0x00000040
25 #define GL_EXACT		0x00000080
26 #define GL_SKIP			0x00000100
27 #define GL_NOCACHE		0x00000400
28 
29 #define GLR_TRYFAILED		13
30 
31 static inline struct gfs2_holder *gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
32 {
33 	struct gfs2_holder *gh;
34 	struct pid *pid;
35 
36 	/* Look in glock's list of holders for one with current task as owner */
37 	spin_lock(&gl->gl_spin);
38 	pid = task_pid(current);
39 	list_for_each_entry(gh, &gl->gl_holders, gh_list) {
40 		if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
41 			break;
42 		if (gh->gh_owner_pid == pid)
43 			goto out;
44 	}
45 	gh = NULL;
46 out:
47 	spin_unlock(&gl->gl_spin);
48 
49 	return gh;
50 }
51 
52 static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
53 {
54 	return gl->gl_state == LM_ST_EXCLUSIVE;
55 }
56 
57 static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
58 {
59 	return gl->gl_state == LM_ST_DEFERRED;
60 }
61 
62 static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
63 {
64 	return gl->gl_state == LM_ST_SHARED;
65 }
66 
67 static inline int gfs2_glock_is_blocking(struct gfs2_glock *gl)
68 {
69 	int ret;
70 	spin_lock(&gl->gl_spin);
71 	ret = test_bit(GLF_DEMOTE, &gl->gl_flags);
72 	spin_unlock(&gl->gl_spin);
73 	return ret;
74 }
75 
76 int gfs2_glock_get(struct gfs2_sbd *sdp,
77 		   u64 number, const struct gfs2_glock_operations *glops,
78 		   int create, struct gfs2_glock **glp);
79 int gfs2_glock_put(struct gfs2_glock *gl);
80 void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
81 		      struct gfs2_holder *gh);
82 void gfs2_holder_reinit(unsigned int state, unsigned flags,
83 			struct gfs2_holder *gh);
84 void gfs2_holder_uninit(struct gfs2_holder *gh);
85 int gfs2_glock_nq(struct gfs2_holder *gh);
86 int gfs2_glock_poll(struct gfs2_holder *gh);
87 int gfs2_glock_wait(struct gfs2_holder *gh);
88 void gfs2_glock_dq(struct gfs2_holder *gh);
89 void gfs2_glock_dq_wait(struct gfs2_holder *gh);
90 
91 void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
92 int gfs2_glock_nq_num(struct gfs2_sbd *sdp,
93 		      u64 number, const struct gfs2_glock_operations *glops,
94 		      unsigned int state, int flags, struct gfs2_holder *gh);
95 
96 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
97 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
98 void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs);
99 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...);
100 
101 /**
102  * gfs2_glock_nq_init - intialize a holder and enqueue it on a glock
103  * @gl: the glock
104  * @state: the state we're requesting
105  * @flags: the modifier flags
106  * @gh: the holder structure
107  *
108  * Returns: 0, GLR_*, or errno
109  */
110 
111 static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
112 				     unsigned int state, int flags,
113 				     struct gfs2_holder *gh)
114 {
115 	int error;
116 
117 	gfs2_holder_init(gl, state, flags, gh);
118 
119 	error = gfs2_glock_nq(gh);
120 	if (error)
121 		gfs2_holder_uninit(gh);
122 
123 	return error;
124 }
125 
126 /*  Lock Value Block functions  */
127 
128 int gfs2_lvb_hold(struct gfs2_glock *gl);
129 void gfs2_lvb_unhold(struct gfs2_glock *gl);
130 
131 void gfs2_glock_cb(void *cb_data, unsigned int type, void *data);
132 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl);
133 void gfs2_reclaim_glock(struct gfs2_sbd *sdp);
134 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
135 
136 int __init gfs2_glock_init(void);
137 void gfs2_glock_exit(void);
138 
139 int gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
140 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
141 int gfs2_register_debugfs(void);
142 void gfs2_unregister_debugfs(void);
143 
144 #endif /* __GLOCK_DOT_H__ */
145