fs/gfs2/glock.h

   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 #define GL_FLOCK                0x00000800
  30 #define GL_NOCANCEL             0x00001000
  31
  32 #define GLR_TRYFAILED           13
  33 #define GLR_CANCELED            14
  34
  35 static inline int gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
  36 {
  37         struct gfs2_holder *gh;
  38         int locked = 0;
  39         struct pid *pid;
  40
  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;
  48                 }
  49         }
  50         spin_unlock(&gl->gl_spin);
  51
  52         return locked;
  53 }
  54
  55 static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
  56 {
  57         return gl->gl_state == LM_ST_EXCLUSIVE;
  58 }
  59
  60 static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
  61 {
  62         return gl->gl_state == LM_ST_DEFERRED;
  63 }
  64
  65 static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
  66 {
  67         return gl->gl_state == LM_ST_SHARED;
  68 }
  69
  70 static inline int gfs2_glock_is_blocking(struct gfs2_glock *gl)
  71 {
  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;
  77 }
  78
  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);
  94
  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);
  99
 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);
 103
 104 /**
 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
 110  *
 111  * Returns: 0, GLR_*, or errno
 112  */
 113
 114 static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
 115                                      unsigned int state, int flags,
 116                                      struct gfs2_holder *gh)
 117 {
 118         int error;
 119
 120         gfs2_holder_init(gl, state, flags, gh);
 121
 122         error = gfs2_glock_nq(gh);
 123         if (error)
 124                 gfs2_holder_uninit(gh);
 125
 126         return error;
 127 }
 128
 129 /*  Lock Value Block functions  */
 130
 131 int gfs2_lvb_hold(struct gfs2_glock *gl);
 132 void gfs2_lvb_unhold(struct gfs2_glock *gl);
 133
 134 void gfs2_glock_cb(void *cb_data, unsigned int type, void *data);
 135
 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);
 139
 140 int __init gfs2_glock_init(void);
 141 void gfs2_glock_exit(void);
 142
 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);
 147
 148 #endif /* __GLOCK_DOT_H__ */