xref: /openbmc/linux/fs/gfs2/glock.h (revision 5029996547a9f3988459e11955c13259495308ef)
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 /* Flags for lock requests; used in gfs2_holder gh_flag field.
14    From lm_interface.h:
15 #define LM_FLAG_TRY		0x00000001
16 #define LM_FLAG_TRY_1CB		0x00000002
17 #define LM_FLAG_NOEXP		0x00000004
18 #define LM_FLAG_ANY		0x00000008
19 #define LM_FLAG_PRIORITY	0x00000010 */
20 
21 #define GL_LOCAL_EXCL		0x00000020
22 #define GL_ASYNC		0x00000040
23 #define GL_EXACT		0x00000080
24 #define GL_SKIP			0x00000100
25 #define GL_ATIME		0x00000200
26 #define GL_NOCACHE		0x00000400
27 #define GL_NOCANCEL		0x00001000
28 #define GL_AOP			0x00004000
29 #define GL_DUMP			0x00008000
30 
31 #define GLR_TRYFAILED		13
32 #define GLR_CANCELED		14
33 
34 static inline int gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
35 {
36 	struct gfs2_holder *gh;
37 	int locked = 0;
38 
39 	/* Look in glock's list of holders for one with current task as owner */
40 	spin_lock(&gl->gl_spin);
41 	list_for_each_entry(gh, &gl->gl_holders, gh_list) {
42 		if (gh->gh_owner == current) {
43 			locked = 1;
44 			break;
45 		}
46 	}
47 	spin_unlock(&gl->gl_spin);
48 
49 	return locked;
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 = !list_empty(&gl->gl_waiters2) || !list_empty(&gl->gl_waiters3);
72 	spin_unlock(&gl->gl_spin);
73 	return ret;
74 }
75 
76 int gfs2_glock_get(struct gfs2_sbd *sdp,
77 		   uint64_t number, const struct gfs2_glock_operations *glops,
78 		   int create, struct gfs2_glock **glp);
79 void gfs2_glock_hold(struct gfs2_glock *gl);
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 
87 void gfs2_glock_xmote_th(struct gfs2_glock *gl, unsigned int state, int flags);
88 void gfs2_glock_drop_th(struct gfs2_glock *gl);
89 
90 int gfs2_glock_nq(struct gfs2_holder *gh);
91 int gfs2_glock_poll(struct gfs2_holder *gh);
92 int gfs2_glock_wait(struct gfs2_holder *gh);
93 void gfs2_glock_dq(struct gfs2_holder *gh);
94 
95 int gfs2_glock_be_greedy(struct gfs2_glock *gl, unsigned int time);
96 
97 void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
98 int gfs2_glock_nq_num(struct gfs2_sbd *sdp,
99 		      uint64_t number, const struct gfs2_glock_operations *glops,
100 		      unsigned int state, int flags, struct gfs2_holder *gh);
101 
102 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
103 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
104 void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs);
105 
106 void gfs2_glock_prefetch_num(struct gfs2_sbd *sdp, uint64_t number,
107 			     const struct gfs2_glock_operations *glops,
108 			     unsigned int state, int flags);
109 void gfs2_glock_inode_squish(struct inode *inode);
110 
111 /**
112  * gfs2_glock_nq_init - intialize a holder and enqueue it on a glock
113  * @gl: the glock
114  * @state: the state we're requesting
115  * @flags: the modifier flags
116  * @gh: the holder structure
117  *
118  * Returns: 0, GLR_*, or errno
119  */
120 
121 static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
122 				     unsigned int state, int flags,
123 				     struct gfs2_holder *gh)
124 {
125 	int error;
126 
127 	gfs2_holder_init(gl, state, flags, gh);
128 
129 	error = gfs2_glock_nq(gh);
130 	if (error)
131 		gfs2_holder_uninit(gh);
132 
133 	return error;
134 }
135 
136 /*  Lock Value Block functions  */
137 
138 int gfs2_lvb_hold(struct gfs2_glock *gl);
139 void gfs2_lvb_unhold(struct gfs2_glock *gl);
140 
141 void gfs2_glock_cb(lm_fsdata_t *fsdata, unsigned int type, void *data);
142 
143 void gfs2_iopen_go_callback(struct gfs2_glock *gl, unsigned int state);
144 
145 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl);
146 void gfs2_reclaim_glock(struct gfs2_sbd *sdp);
147 
148 void gfs2_scand_internal(struct gfs2_sbd *sdp);
149 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait);
150 
151 #endif /* __GLOCK_DOT_H__ */
152