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 struct gfs2_holder *gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
  36 {
  37         struct gfs2_holder *gh;
  38         struct pid *pid;
  39
  40         /* Look in glock's list of holders for one with current task as owner */
  41         spin_lock(&gl->gl_spin);
  42         pid = task_pid(current);
  43         list_for_each_entry(gh, &gl->gl_holders, gh_list) {
  44                 if (gh->gh_owner_pid == pid)
  45                         goto out;
  46         }
  47         gh = NULL;
  48 out:
  49         spin_unlock(&gl->gl_spin);
  50
  51         return gh;
  52 }
  53
  54 static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
  55 {
  56         return gl->gl_state == LM_ST_EXCLUSIVE;
  57 }
  58
  59 static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
  60 {
  61         return gl->gl_state == LM_ST_DEFERRED;
  62 }
  63
  64 static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
  65 {
  66         return gl->gl_state == LM_ST_SHARED;
  67 }
  68
  69 static inline int gfs2_glock_is_blocking(struct gfs2_glock *gl)
  70 {
  71         int ret;
  72         spin_lock(&gl->gl_spin);
  73         ret = test_bit(GLF_DEMOTE, &gl->gl_flags) || !list_empty(&gl->gl_waiters3);
  74         spin_unlock(&gl->gl_spin);
  75         return ret;
  76 }
  77
  78 int gfs2_glock_get(struct gfs2_sbd *sdp,
  79                    u64 number, const struct gfs2_glock_operations *glops,
  80                    int create, struct gfs2_glock **glp);
  81 int gfs2_glock_put(struct gfs2_glock *gl);
  82 void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
  83                       struct gfs2_holder *gh);
  84 void gfs2_holder_reinit(unsigned int state, unsigned flags,
  85                         struct gfs2_holder *gh);
  86 void gfs2_holder_uninit(struct gfs2_holder *gh);
  87 int gfs2_glock_nq(struct gfs2_holder *gh);
  88 int gfs2_glock_poll(struct gfs2_holder *gh);
  89 int gfs2_glock_wait(struct gfs2_holder *gh);
  90 void gfs2_glock_dq(struct gfs2_holder *gh);
  91 void gfs2_glock_dq_wait(struct gfs2_holder *gh);
  92
  93 void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
  94 int gfs2_glock_nq_num(struct gfs2_sbd *sdp,
  95                       u64 number, const struct gfs2_glock_operations *glops,
  96                       unsigned int state, int flags, struct gfs2_holder *gh);
  97
  98 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
  99 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
 100 void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs);
 101
 102 /**
 103  * gfs2_glock_nq_init - intialize a holder and enqueue it on a glock
 104  * @gl: the glock
 105  * @state: the state we're requesting
 106  * @flags: the modifier flags
 107  * @gh: the holder structure
 108  *
 109  * Returns: 0, GLR_*, or errno
 110  */
 111
 112 static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
 113                                      unsigned int state, int flags,
 114                                      struct gfs2_holder *gh)
 115 {
 116         int error;
 117
 118         gfs2_holder_init(gl, state, flags, gh);
 119
 120         error = gfs2_glock_nq(gh);
 121         if (error)
 122                 gfs2_holder_uninit(gh);
 123
 124         return error;
 125 }
 126
 127 /*  Lock Value Block functions  */
 128
 129 int gfs2_lvb_hold(struct gfs2_glock *gl);
 130 void gfs2_lvb_unhold(struct gfs2_glock *gl);
 131
 132 void gfs2_glock_cb(void *cb_data, unsigned int type, void *data);
 133
 134 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl);
 135 void gfs2_reclaim_glock(struct gfs2_sbd *sdp);
 136 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait);
 137
 138 int __init gfs2_glock_init(void);
 139 void gfs2_glock_exit(void);
 140
 141 int gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
 142 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
 143 int gfs2_register_debugfs(void);
 144 void gfs2_unregister_debugfs(void);
 145
 146 #endif /* __GLOCK_DOT_H__ */