Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
[wrt350n-kernel.git] / fs / gfs2 / glock.h
blob2f9c6d136b37a860a790367a35e02c2e59d47130
1 /*
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
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 */
10 #ifndef __GLOCK_DOT_H__
11 #define __GLOCK_DOT_H__
13 #include <linux/sched.h>
14 #include "incore.h"
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 */
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 #define GL_FLOCK 0x00000800
30 #define GL_NOCANCEL 0x00001000
32 #define GLR_TRYFAILED 13
33 #define GLR_CANCELED 14
35 static inline int gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
37 struct gfs2_holder *gh;
38 int locked = 0;
39 struct pid *pid;
41 /* Look in glock's list of holders for one with current task as owner */
42 spin_lock(&gl->gl_spin);
43 pid = task_pid(current);
44 list_for_each_entry(gh, &gl->gl_holders, gh_list) {
45 if (gh->gh_owner_pid == pid) {
46 locked = 1;
47 break;
50 spin_unlock(&gl->gl_spin);
52 return locked;
55 static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
57 return gl->gl_state == LM_ST_EXCLUSIVE;
60 static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
62 return gl->gl_state == LM_ST_DEFERRED;
65 static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
67 return gl->gl_state == LM_ST_SHARED;
70 static inline int gfs2_glock_is_blocking(struct gfs2_glock *gl)
72 int ret;
73 spin_lock(&gl->gl_spin);
74 ret = test_bit(GLF_DEMOTE, &gl->gl_flags) || !list_empty(&gl->gl_waiters3);
75 spin_unlock(&gl->gl_spin);
76 return ret;
79 int gfs2_glock_get(struct gfs2_sbd *sdp,
80 u64 number, const struct gfs2_glock_operations *glops,
81 int create, struct gfs2_glock **glp);
82 void gfs2_glock_hold(struct gfs2_glock *gl);
83 int gfs2_glock_put(struct gfs2_glock *gl);
84 void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
85 struct gfs2_holder *gh);
86 void gfs2_holder_reinit(unsigned int state, unsigned flags,
87 struct gfs2_holder *gh);
88 void gfs2_holder_uninit(struct gfs2_holder *gh);
89 int gfs2_glock_nq(struct gfs2_holder *gh);
90 int gfs2_glock_poll(struct gfs2_holder *gh);
91 int gfs2_glock_wait(struct gfs2_holder *gh);
92 void gfs2_glock_dq(struct gfs2_holder *gh);
93 void gfs2_glock_dq_wait(struct gfs2_holder *gh);
95 void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
96 int gfs2_glock_nq_num(struct gfs2_sbd *sdp,
97 u64 number, const struct gfs2_glock_operations *glops,
98 unsigned int state, int flags, struct gfs2_holder *gh);
100 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
101 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
102 void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs);
105 * gfs2_glock_nq_init - intialize a holder and enqueue it on a glock
106 * @gl: the glock
107 * @state: the state we're requesting
108 * @flags: the modifier flags
109 * @gh: the holder structure
111 * Returns: 0, GLR_*, or errno
114 static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
115 unsigned int state, int flags,
116 struct gfs2_holder *gh)
118 int error;
120 gfs2_holder_init(gl, state, flags, gh);
122 error = gfs2_glock_nq(gh);
123 if (error)
124 gfs2_holder_uninit(gh);
126 return error;
129 /* Lock Value Block functions */
131 int gfs2_lvb_hold(struct gfs2_glock *gl);
132 void gfs2_lvb_unhold(struct gfs2_glock *gl);
134 void gfs2_glock_cb(void *cb_data, unsigned int type, void *data);
136 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl);
137 void gfs2_reclaim_glock(struct gfs2_sbd *sdp);
138 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait);
140 int __init gfs2_glock_init(void);
141 void gfs2_glock_exit(void);
143 int gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
144 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
145 int gfs2_register_debugfs(void);
146 void gfs2_unregister_debugfs(void);
148 #endif /* __GLOCK_DOT_H__ */