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_LOCAL_EXCL           0x00000020
  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_NOCANCEL             0x00001000
  30 #define GL_AOP                  0x00004000
  31 #define GL_DUMP                 0x00008000
  32
  33 #define GLR_TRYFAILED           13
  34 #define GLR_CANCELED            14
  35
  36 static inline int gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
  37 {
  38         struct gfs2_holder *gh;
  39         int locked = 0;
  40
  41         /* Look in glock's list of holders for one with current task as owner */
  42         spin_lock(&gl->gl_spin);
  43         list_for_each_entry(gh, &gl->gl_holders, gh_list) {
  44                 if (gh->gh_owner == current) {
  45                         locked = 1;
  46                         break;
  47                 }
  48         }
  49         spin_unlock(&gl->gl_spin);
  50
  51         return locked;
  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 = !list_empty(&gl->gl_waiters2) || !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 void gfs2_glock_hold(struct gfs2_glock *gl);
  82 int gfs2_glock_put(struct gfs2_glock *gl);
  83 void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
  84                       struct gfs2_holder *gh);
  85 void gfs2_holder_reinit(unsigned int state, unsigned flags,
  86                         struct gfs2_holder *gh);
  87 void gfs2_holder_uninit(struct gfs2_holder *gh);
  88
  89 void gfs2_glock_xmote_th(struct gfs2_glock *gl, unsigned int state, int flags);
  90 void gfs2_glock_drop_th(struct gfs2_glock *gl);
  91
  92 int gfs2_glock_nq(struct gfs2_holder *gh);
  93 int gfs2_glock_poll(struct gfs2_holder *gh);
  94 int gfs2_glock_wait(struct gfs2_holder *gh);
  95 void gfs2_glock_dq(struct gfs2_holder *gh);
  96
  97 int gfs2_glock_be_greedy(struct gfs2_glock *gl, unsigned int time);
  98
  99 void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
 100 int gfs2_glock_nq_num(struct gfs2_sbd *sdp,
 101                       u64 number, const struct gfs2_glock_operations *glops,
 102                       unsigned int state, int flags, struct gfs2_holder *gh);
 103
 104 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
 105 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
 106 void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs);
 107
 108 void gfs2_glock_prefetch_num(struct gfs2_sbd *sdp, u64 number,
 109                              const struct gfs2_glock_operations *glops,
 110                              unsigned int state, int flags);
 111 void gfs2_glock_inode_squish(struct inode *inode);
 112
 113 /**
 114  * gfs2_glock_nq_init - intialize a holder and enqueue it on a glock
 115  * @gl: the glock
 116  * @state: the state we're requesting
 117  * @flags: the modifier flags
 118  * @gh: the holder structure
 119  *
 120  * Returns: 0, GLR_*, or errno
 121  */
 122
 123 static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
 124                                      unsigned int state, int flags,
 125                                      struct gfs2_holder *gh)
 126 {
 127         int error;
 128
 129         gfs2_holder_init(gl, state, flags, gh);
 130
 131         error = gfs2_glock_nq(gh);
 132         if (error)
 133                 gfs2_holder_uninit(gh);
 134
 135         return error;
 136 }
 137
 138 /*  Lock Value Block functions  */
 139
 140 int gfs2_lvb_hold(struct gfs2_glock *gl);
 141 void gfs2_lvb_unhold(struct gfs2_glock *gl);
 142
 143 void gfs2_glock_cb(void *cb_data, unsigned int type, void *data);
 144
 145 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl);
 146 void gfs2_reclaim_glock(struct gfs2_sbd *sdp);
 147
 148 void gfs2_scand_internal(struct gfs2_sbd *sdp);
 149 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait);
 150
 151 int __init gfs2_glock_init(void);
 152
 153 #endif /* __GLOCK_DOT_H__ */