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_NOCACHE              0x00000400
  28
  29 #define GLR_TRYFAILED           13
  30
  31 static inline struct gfs2_holder *gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
  32 {
  33         struct gfs2_holder *gh;
  34         struct pid *pid;
  35
  36         /* Look in glock's list of holders for one with current task as owner */
  37         spin_lock(&gl->gl_spin);
  38         pid = task_pid(current);
  39         list_for_each_entry(gh, &gl->gl_holders, gh_list) {
  40                 if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
  41                         break;
  42                 if (gh->gh_owner_pid == pid)
  43                         goto out;
  44         }
  45         gh = NULL;
  46 out:
  47         spin_unlock(&gl->gl_spin);
  48
  49         return gh;
  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 = test_bit(GLF_DEMOTE, &gl->gl_flags);
  72         spin_unlock(&gl->gl_spin);
  73         return ret;
  74 }
  75
  76 int gfs2_glock_get(struct gfs2_sbd *sdp,
  77                    u64 number, const struct gfs2_glock_operations *glops,
  78                    int create, struct gfs2_glock **glp);
  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 void gfs2_glock_dq_wait(struct gfs2_holder *gh);
  90
  91 void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
  92 int gfs2_glock_nq_num(struct gfs2_sbd *sdp,
  93                       u64 number, const struct gfs2_glock_operations *glops,
  94                       unsigned int state, int flags, struct gfs2_holder *gh);
  95
  96 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
  97 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
  98 void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs);
  99 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...);
 100
 101 /**
 102  * gfs2_glock_nq_init - intialize a holder and enqueue it on a glock
 103  * @gl: the glock
 104  * @state: the state we're requesting
 105  * @flags: the modifier flags
 106  * @gh: the holder structure
 107  *
 108  * Returns: 0, GLR_*, or errno
 109  */
 110
 111 static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
 112                                      unsigned int state, int flags,
 113                                      struct gfs2_holder *gh)
 114 {
 115         int error;
 116
 117         gfs2_holder_init(gl, state, flags, gh);
 118
 119         error = gfs2_glock_nq(gh);
 120         if (error)
 121                 gfs2_holder_uninit(gh);
 122
 123         return error;
 124 }
 125
 126 /*  Lock Value Block functions  */
 127
 128 int gfs2_lvb_hold(struct gfs2_glock *gl);
 129 void gfs2_lvb_unhold(struct gfs2_glock *gl);
 130
 131 void gfs2_glock_cb(void *cb_data, unsigned int type, void *data);
 132 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl);
 133 void gfs2_reclaim_glock(struct gfs2_sbd *sdp);
 134 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
 135
 136 int __init gfs2_glock_init(void);
 137 void gfs2_glock_exit(void);
 138
 139 int gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
 140 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
 141 int gfs2_register_debugfs(void);
 142 void gfs2_unregister_debugfs(void);
 143
 144 #endif /* __GLOCK_DOT_H__ */