xref: /openbmc/linux/fs/gfs2/glock.h (revision 6802e340)
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_ATIME		0x00000200
28 #define GL_NOCACHE		0x00000400
29 
30 #define GLR_TRYFAILED		13
31 
32 static inline struct gfs2_holder *gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
33 {
34 	struct gfs2_holder *gh;
35 	struct pid *pid;
36 
37 	/* Look in glock's list of holders for one with current task as owner */
38 	spin_lock(&gl->gl_spin);
39 	pid = task_pid(current);
40 	list_for_each_entry(gh, &gl->gl_holders, gh_list) {
41 		if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
42 			break;
43 		if (gh->gh_owner_pid == pid)
44 			goto out;
45 	}
46 	gh = NULL;
47 out:
48 	spin_unlock(&gl->gl_spin);
49 
50 	return gh;
51 }
52 
53 static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
54 {
55 	return gl->gl_state == LM_ST_EXCLUSIVE;
56 }
57 
58 static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
59 {
60 	return gl->gl_state == LM_ST_DEFERRED;
61 }
62 
63 static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
64 {
65 	return gl->gl_state == LM_ST_SHARED;
66 }
67 
68 static inline int gfs2_glock_is_blocking(struct gfs2_glock *gl)
69 {
70 	int ret;
71 	spin_lock(&gl->gl_spin);
72 	ret = test_bit(GLF_DEMOTE, &gl->gl_flags);
73 	spin_unlock(&gl->gl_spin);
74 	return ret;
75 }
76 
77 int gfs2_glock_get(struct gfs2_sbd *sdp,
78 		   u64 number, const struct gfs2_glock_operations *glops,
79 		   int create, struct gfs2_glock **glp);
80 int gfs2_glock_put(struct gfs2_glock *gl);
81 void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
82 		      struct gfs2_holder *gh);
83 void gfs2_holder_reinit(unsigned int state, unsigned flags,
84 			struct gfs2_holder *gh);
85 void gfs2_holder_uninit(struct gfs2_holder *gh);
86 int gfs2_glock_nq(struct gfs2_holder *gh);
87 int gfs2_glock_poll(struct gfs2_holder *gh);
88 int gfs2_glock_wait(struct gfs2_holder *gh);
89 void gfs2_glock_dq(struct gfs2_holder *gh);
90 void gfs2_glock_dq_wait(struct gfs2_holder *gh);
91 
92 void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
93 int gfs2_glock_nq_num(struct gfs2_sbd *sdp,
94 		      u64 number, const struct gfs2_glock_operations *glops,
95 		      unsigned int state, int flags, struct gfs2_holder *gh);
96 
97 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
98 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
99 void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs);
100 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...);
101 
102 /**
103  * gfs2_glock_nq_init - intialize a holder and enqueue it on a glock
104  * @gl: the glock
105  * @state: the state we're requesting
106  * @flags: the modifier flags
107  * @gh: the holder structure
108  *
109  * Returns: 0, GLR_*, or errno
110  */
111 
112 static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
113 				     unsigned int state, int flags,
114 				     struct gfs2_holder *gh)
115 {
116 	int error;
117 
118 	gfs2_holder_init(gl, state, flags, gh);
119 
120 	error = gfs2_glock_nq(gh);
121 	if (error)
122 		gfs2_holder_uninit(gh);
123 
124 	return error;
125 }
126 
127 /*  Lock Value Block functions  */
128 
129 int gfs2_lvb_hold(struct gfs2_glock *gl);
130 void gfs2_lvb_unhold(struct gfs2_glock *gl);
131 
132 void gfs2_glock_cb(void *cb_data, unsigned int type, void *data);
133 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl);
134 void gfs2_reclaim_glock(struct gfs2_sbd *sdp);
135 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait);
136 
137 int __init gfs2_glock_init(void);
138 void gfs2_glock_exit(void);
139 
140 int gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
141 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
142 int gfs2_register_debugfs(void);
143 void gfs2_unregister_debugfs(void);
144 
145 #endif /* __GLOCK_DOT_H__ */
146