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 "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__ */