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 v.2.
   8  */
   9
  10 #ifndef __GLOCK_DOT_H__
  11 #define __GLOCK_DOT_H__
  12
  13 /* Flags for lock requests; used in gfs2_holder gh_flag field.
  14    From lm_interface.h:
  15 #define LM_FLAG_TRY             0x00000001
  16 #define LM_FLAG_TRY_1CB         0x00000002
  17 #define LM_FLAG_NOEXP           0x00000004
  18 #define LM_FLAG_ANY             0x00000008
  19 #define LM_FLAG_PRIORITY        0x00000010 */
  20
  21 #define GL_LOCAL_EXCL           0x00000020
  22 #define GL_ASYNC                0x00000040
  23 #define GL_EXACT                0x00000080
  24 #define GL_SKIP                 0x00000100
  25 #define GL_ATIME                0x00000200
  26 #define GL_NOCACHE              0x00000400
  27 #define GL_SYNC                 0x00000800
  28 #define GL_NOCANCEL             0x00001000
  29 #define GL_AOP                  0x00004000
  30 #define GL_DUMP                 0x00008000
  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
  40         /* Look in glock's list of holders for one with current task as owner */
  41         spin_lock(&gl->gl_spin);
  42         list_for_each_entry(gh, &gl->gl_holders, gh_list) {
  43                 if (gh->gh_owner == current) {
  44                         locked = 1;
  45                         break;
  46                 }
  47         }
  48         spin_unlock(&gl->gl_spin);
  49
  50         return locked;
  51 }
  52
  53 static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
  54 {
  55         return (gl->gl_state == LM_ST_EXCLUSIVE);
  56 }
  57
  58 static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
  59 {
  60         return (gl->gl_state == LM_ST_DEFERRED);
  61 }
  62
  63 static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
  64 {
  65         return (gl->gl_state == LM_ST_SHARED);
  66 }
  67
  68 static inline int gfs2_glock_is_blocking(struct gfs2_glock *gl)
  69 {
  70         int ret;
  71         spin_lock(&gl->gl_spin);
  72         ret = !list_empty(&gl->gl_waiters2) || !list_empty(&gl->gl_waiters3);
  73         spin_unlock(&gl->gl_spin);
  74         return ret;
  75 }
  76
  77 int gfs2_glock_get(struct gfs2_sbd *sdp,
  78                    uint64_t number, struct gfs2_glock_operations *glops,
  79                    int create, struct gfs2_glock **glp);
  80 void gfs2_glock_hold(struct gfs2_glock *gl);
  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
  88 void gfs2_glock_xmote_th(struct gfs2_glock *gl, unsigned int state, int flags);
  89 void gfs2_glock_drop_th(struct gfs2_glock *gl);
  90
  91 int gfs2_glock_nq(struct gfs2_holder *gh);
  92 int gfs2_glock_poll(struct gfs2_holder *gh);
  93 int gfs2_glock_wait(struct gfs2_holder *gh);
  94 void gfs2_glock_dq(struct gfs2_holder *gh);
  95
  96 int gfs2_glock_be_greedy(struct gfs2_glock *gl, unsigned int time);
  97
  98 void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
  99 int gfs2_glock_nq_num(struct gfs2_sbd *sdp,
 100                       uint64_t number, struct gfs2_glock_operations *glops,
 101                       unsigned int state, int flags, struct gfs2_holder *gh);
 102
 103 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
 104 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
 105 void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs);
 106
 107 void gfs2_glock_prefetch_num(struct gfs2_sbd *sdp, uint64_t number,
 108                              struct gfs2_glock_operations *glops,
 109                              unsigned int state, int flags);
 110 void gfs2_glock_inode_squish(struct inode *inode);
 111
 112 /**
 113  * gfs2_glock_nq_init - intialize a holder and enqueue it on a glock
 114  * @gl: the glock
 115  * @state: the state we're requesting
 116  * @flags: the modifier flags
 117  * @gh: the holder structure
 118  *
 119  * Returns: 0, GLR_*, or errno
 120  */
 121
 122 static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
 123                                      unsigned int state, int flags,
 124                                      struct gfs2_holder *gh)
 125 {
 126         int error;
 127
 128         gfs2_holder_init(gl, state, flags, gh);
 129
 130         error = gfs2_glock_nq(gh);
 131         if (error)
 132                 gfs2_holder_uninit(gh);
 133
 134         return error;
 135 }
 136
 137 /*  Lock Value Block functions  */
 138
 139 int gfs2_lvb_hold(struct gfs2_glock *gl);
 140 void gfs2_lvb_unhold(struct gfs2_glock *gl);
 141
 142 void gfs2_glock_cb(lm_fsdata_t *fsdata, unsigned int type, void *data);
 143
 144 void gfs2_iopen_go_callback(struct gfs2_glock *gl, unsigned int state);
 145
 146 void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl);
 147 void gfs2_reclaim_glock(struct gfs2_sbd *sdp);
 148
 149 void gfs2_scand_internal(struct gfs2_sbd *sdp);
 150 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait);
 151
 152 #endif /* __GLOCK_DOT_H__ */