xref: /openbmc/linux/fs/gfs2/glock.h (revision e868d61272caa648214046a096e5a6bfc068dc8c)
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 "incore.h"
14 
15 /* Flags for lock requests; used in gfs2_holder gh_flag field.
16    From lm_interface.h:
17 #define LM_FLAG_TRY		0x00000001
18 #define LM_FLAG_TRY_1CB		0x00000002
19 #define LM_FLAG_NOEXP		0x00000004
20 #define LM_FLAG_ANY		0x00000008
21 #define LM_FLAG_PRIORITY	0x00000010 */
22 
23 #define GL_ASYNC		0x00000040
24 #define GL_EXACT		0x00000080
25 #define GL_SKIP			0x00000100
26 #define GL_ATIME		0x00000200
27 #define GL_NOCACHE		0x00000400
28 #define GL_NOCANCEL		0x00001000
29 
30 #define GLR_TRYFAILED		13
31 #define GLR_CANCELED		14
32 
33 static inline int gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
34 {
35 	struct gfs2_holder *gh;
36 	int locked = 0;
37 
38 	/* Look in glock's list of holders for one with current task as owner */
39 	spin_lock(&gl->gl_spin);
40 	list_for_each_entry(gh, &gl->gl_holders, gh_list) {
41 		if (gh->gh_owner_pid == current->pid) {
42 			locked = 1;
43 			break;
44 		}
45 	}
46 	spin_unlock(&gl->gl_spin);
47 
48 	return locked;
49 }
50 
51 static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
52 {
53 	return gl->gl_state == LM_ST_EXCLUSIVE;
54 }
55 
56 static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
57 {
58 	return gl->gl_state == LM_ST_DEFERRED;
59 }
60 
61 static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
62 {
63 	return gl->gl_state == LM_ST_SHARED;
64 }
65 
66 static inline int gfs2_glock_is_blocking(struct gfs2_glock *gl)
67 {
68 	int ret;
69 	spin_lock(&gl->gl_spin);
70 	ret = test_bit(GLF_DEMOTE, &gl->gl_flags) || !list_empty(&gl->gl_waiters3);
71 	spin_unlock(&gl->gl_spin);
72 	return ret;
73 }
74 
75 int gfs2_glock_get(struct gfs2_sbd *sdp,
76 		   u64 number, const struct gfs2_glock_operations *glops,
77 		   int create, struct gfs2_glock **glp);
78 void gfs2_glock_hold(struct gfs2_glock *gl);
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 
90 void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
91 int gfs2_glock_nq_num(struct gfs2_sbd *sdp,
92 		      u64 number, const struct gfs2_glock_operations *glops,
93 		      unsigned int state, int flags, struct gfs2_holder *gh);
94 
95 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
96 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
97 void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs);
98 
99 /**
100  * gfs2_glock_nq_init - intialize a holder and enqueue it on a glock
101  * @gl: the glock
102  * @state: the state we're requesting
103  * @flags: the modifier flags
104  * @gh: the holder structure
105  *
106  * Returns: 0, GLR_*, or errno
107  */
108 
109 static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
110 				     unsigned int state, int flags,
111 				     struct gfs2_holder *gh)
112 {
113 	int error;
114 
115 	gfs2_holder_init(gl, state, flags, gh);
116 
117 	error = gfs2_glock_nq(gh);
118 	if (error)
119 		gfs2_holder_uninit(gh);
120 
121 	return error;
122 }
123 
124 /*  Lock Value Block functions  */
125 
126 int gfs2_lvb_hold(struct gfs2_glock *gl);
127 void gfs2_lvb_unhold(struct gfs2_glock *gl);
128 
129 void gfs2_glock_cb(void *cb_data, unsigned int type, void *data);
130 
131 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl);
132 void gfs2_reclaim_glock(struct gfs2_sbd *sdp);
133 
134 void gfs2_scand_internal(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 int gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
139 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
140 int gfs2_register_debugfs(void);
141 void gfs2_unregister_debugfs(void);
142 
143 #endif /* __GLOCK_DOT_H__ */
144