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 <linux/parser.h>
  15 #include "incore.h"
  16
  17 /* Options for hostdata parser */
  18
  19 enum {
  20         Opt_jid,
  21         Opt_id,
  22         Opt_first,
  23         Opt_nodir,
  24         Opt_err,
  25 };
  26
  27 /*
  28  * lm_lockname types
  29  */
  30
  31 #define LM_TYPE_RESERVED        0x00
  32 #define LM_TYPE_NONDISK         0x01
  33 #define LM_TYPE_INODE           0x02
  34 #define LM_TYPE_RGRP            0x03
  35 #define LM_TYPE_META            0x04
  36 #define LM_TYPE_IOPEN           0x05
  37 #define LM_TYPE_FLOCK           0x06
  38 #define LM_TYPE_PLOCK           0x07
  39 #define LM_TYPE_QUOTA           0x08
  40 #define LM_TYPE_JOURNAL         0x09
  41
  42 /*
  43  * lm_lock() states
  44  *
  45  * SHARED is compatible with SHARED, not with DEFERRED or EX.
  46  * DEFERRED is compatible with DEFERRED, not with SHARED or EX.
  47  */
  48
  49 #define LM_ST_UNLOCKED          0
  50 #define LM_ST_EXCLUSIVE         1
  51 #define LM_ST_DEFERRED          2
  52 #define LM_ST_SHARED            3
  53
  54 /*
  55  * lm_lock() flags
  56  *
  57  * LM_FLAG_TRY
  58  * Don't wait to acquire the lock if it can't be granted immediately.
  59  *
  60  * LM_FLAG_TRY_1CB
  61  * Send one blocking callback if TRY is set and the lock is not granted.
  62  *
  63  * LM_FLAG_NOEXP
  64  * GFS sets this flag on lock requests it makes while doing journal recovery.
  65  * These special requests should not be blocked due to the recovery like
  66  * ordinary locks would be.
  67  *
  68  * LM_FLAG_ANY
  69  * A SHARED request may also be granted in DEFERRED, or a DEFERRED request may
  70  * also be granted in SHARED.  The preferred state is whichever is compatible
  71  * with other granted locks, or the specified state if no other locks exist.
  72  *
  73  * LM_FLAG_PRIORITY
  74  * Override fairness considerations.  Suppose a lock is held in a shared state
  75  * and there is a pending request for the deferred state.  A shared lock
  76  * request with the priority flag would be allowed to bypass the deferred
  77  * request and directly join the other shared lock.  A shared lock request
  78  * without the priority flag might be forced to wait until the deferred
  79  * requested had acquired and released the lock.
  80  */
  81
  82 #define LM_FLAG_TRY             0x00000001
  83 #define LM_FLAG_TRY_1CB         0x00000002
  84 #define LM_FLAG_NOEXP           0x00000004
  85 #define LM_FLAG_ANY             0x00000008
  86 #define LM_FLAG_PRIORITY        0x00000010
  87 #define GL_ASYNC                0x00000040
  88 #define GL_EXACT                0x00000080
  89 #define GL_SKIP                 0x00000100
  90 #define GL_ATIME                0x00000200
  91 #define GL_NOCACHE              0x00000400
  92
  93 /*
  94  * lm_lock() and lm_async_cb return flags
  95  *
  96  * LM_OUT_ST_MASK
  97  * Masks the lower two bits of lock state in the returned value.
  98  *
  99  * LM_OUT_CANCELED
 100  * The lock request was canceled.
 101  *
 102  * LM_OUT_ASYNC
 103  * The result of the request will be returned in an LM_CB_ASYNC callback.
 104  *
 105  */
 106
 107 #define LM_OUT_ST_MASK          0x00000003
 108 #define LM_OUT_CANCELED         0x00000008
 109 #define LM_OUT_ASYNC            0x00000080
 110 #define LM_OUT_ERROR            0x00000100
 111
 112 /*
 113  * lm_recovery_done() messages
 114  */
 115
 116 #define LM_RD_GAVEUP            308
 117 #define LM_RD_SUCCESS           309
 118
 119 #define GLR_TRYFAILED           13
 120
 121 struct lm_lockops {
 122         const char *lm_proto_name;
 123         int (*lm_mount) (struct gfs2_sbd *sdp, const char *fsname);
 124         void (*lm_unmount) (struct gfs2_sbd *sdp);
 125         void (*lm_withdraw) (struct gfs2_sbd *sdp);
 126         void (*lm_put_lock) (struct kmem_cache *cachep, void *gl);
 127         unsigned int (*lm_lock) (struct gfs2_glock *gl,
 128                                  unsigned int req_state, unsigned int flags);
 129         void (*lm_cancel) (struct gfs2_glock *gl);
 130         const match_table_t *lm_tokens;
 131 };
 132
 133 #define LM_FLAG_TRY             0x00000001
 134 #define LM_FLAG_TRY_1CB         0x00000002
 135 #define LM_FLAG_NOEXP           0x00000004
 136 #define LM_FLAG_ANY             0x00000008
 137 #define LM_FLAG_PRIORITY        0x00000010
 138
 139 #define GL_ASYNC                0x00000040
 140 #define GL_EXACT                0x00000080
 141 #define GL_SKIP                 0x00000100
 142 #define GL_NOCACHE              0x00000400
 143
 144 #define GLR_TRYFAILED           13
 145
 146 extern struct workqueue_struct *gfs2_delete_workqueue;
 147 static inline struct gfs2_holder *gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
 148 {
 149         struct gfs2_holder *gh;
 150         struct pid *pid;
 151
 152         /* Look in glock's list of holders for one with current task as owner */
 153         spin_lock(&gl->gl_spin);
 154         pid = task_pid(current);
 155         list_for_each_entry(gh, &gl->gl_holders, gh_list) {
 156                 if (!test_bit(HIF_HOLDER, &gh->gh_iflags))
 157                         break;
 158                 if (gh->gh_owner_pid == pid)
 159                         goto out;
 160         }
 161         gh = NULL;
 162 out:
 163         spin_unlock(&gl->gl_spin);
 164
 165         return gh;
 166 }
 167
 168 static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
 169 {
 170         return gl->gl_state == LM_ST_EXCLUSIVE;
 171 }
 172
 173 static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
 174 {
 175         return gl->gl_state == LM_ST_DEFERRED;
 176 }
 177
 178 static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
 179 {
 180         return gl->gl_state == LM_ST_SHARED;
 181 }
 182
 183 static inline int gfs2_glock_is_blocking(struct gfs2_glock *gl)
 184 {
 185         int ret;
 186         spin_lock(&gl->gl_spin);
 187         ret = test_bit(GLF_DEMOTE, &gl->gl_flags);
 188         spin_unlock(&gl->gl_spin);
 189         return ret;
 190 }
 191
 192 int gfs2_glock_get(struct gfs2_sbd *sdp,
 193                    u64 number, const struct gfs2_glock_operations *glops,
 194                    int create, struct gfs2_glock **glp);
 195 void gfs2_glock_hold(struct gfs2_glock *gl);
 196 void gfs2_glock_put_nolock(struct gfs2_glock *gl);
 197 int gfs2_glock_put(struct gfs2_glock *gl);
 198 void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
 199                       struct gfs2_holder *gh);
 200 void gfs2_holder_reinit(unsigned int state, unsigned flags,
 201                         struct gfs2_holder *gh);
 202 void gfs2_holder_uninit(struct gfs2_holder *gh);
 203 int gfs2_glock_nq(struct gfs2_holder *gh);
 204 int gfs2_glock_poll(struct gfs2_holder *gh);
 205 int gfs2_glock_wait(struct gfs2_holder *gh);
 206 void gfs2_glock_dq(struct gfs2_holder *gh);
 207 void gfs2_glock_dq_wait(struct gfs2_holder *gh);
 208
 209 void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
 210 int gfs2_glock_nq_num(struct gfs2_sbd *sdp,
 211                       u64 number, const struct gfs2_glock_operations *glops,
 212                       unsigned int state, int flags, struct gfs2_holder *gh);
 213
 214 int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
 215 void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
 216 void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs);
 217 void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...);
 218
 219 /**
 220  * gfs2_glock_nq_init - intialize a holder and enqueue it on a glock
 221  * @gl: the glock
 222  * @state: the state we're requesting
 223  * @flags: the modifier flags
 224  * @gh: the holder structure
 225  *
 226  * Returns: 0, GLR_*, or errno
 227  */
 228
 229 static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
 230                                      unsigned int state, int flags,
 231                                      struct gfs2_holder *gh)
 232 {
 233         int error;
 234
 235         gfs2_holder_init(gl, state, flags, gh);
 236
 237         error = gfs2_glock_nq(gh);
 238         if (error)
 239                 gfs2_holder_uninit(gh);
 240
 241         return error;
 242 }
 243
 244 /*  Lock Value Block functions  */
 245
 246 int gfs2_lvb_hold(struct gfs2_glock *gl);
 247 void gfs2_lvb_unhold(struct gfs2_glock *gl);
 248
 249 void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state);
 250 void gfs2_glock_complete(struct gfs2_glock *gl, int ret);
 251 void gfs2_reclaim_glock(struct gfs2_sbd *sdp);
 252 void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);
 253 void gfs2_glock_finish_truncate(struct gfs2_inode *ip);
 254 void gfs2_glock_thaw(struct gfs2_sbd *sdp);
 255
 256 int __init gfs2_glock_init(void);
 257 void gfs2_glock_exit(void);
 258
 259 int gfs2_create_debugfs_file(struct gfs2_sbd *sdp);
 260 void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp);
 261 int gfs2_register_debugfs(void);
 262 void gfs2_unregister_debugfs(void);
 263
 264 extern const struct lm_lockops gfs2_dlm_ops;
 265
 266 #endif /* __GLOCK_DOT_H__ */