include/linux/dlmconstants.h

   1 /******************************************************************************
   2 *******************************************************************************
   3 **
   4 **  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
   5 **  Copyright (C) 2004-2007 Red Hat, Inc.  All rights reserved.
   6 **
   7 **  This copyrighted material is made available to anyone wishing to use,
   8 **  modify, copy, or redistribute it subject to the terms and conditions
   9 **  of the GNU General Public License v.2.
  10 **
  11 *******************************************************************************
  12 ******************************************************************************/
  13
  14 #ifndef __DLMCONSTANTS_DOT_H__
  15 #define __DLMCONSTANTS_DOT_H__
  16
  17 /*
  18  * Constants used by DLM interface.
  19  */
  20
  21 /*
  22  * Lock Modes
  23  */
  24
  25 #define DLM_LOCK_IV             (-1)    /* invalid */
  26 #define DLM_LOCK_NL             0       /* null */
  27 #define DLM_LOCK_CR             1       /* concurrent read */
  28 #define DLM_LOCK_CW             2       /* concurrent write */
  29 #define DLM_LOCK_PR             3       /* protected read */
  30 #define DLM_LOCK_PW             4       /* protected write */
  31 #define DLM_LOCK_EX             5       /* exclusive */
  32
  33
  34 /*
  35  * Flags to dlm_lock
  36  *
  37  * DLM_LKF_NOQUEUE
  38  *
  39  * Do not queue the lock request on the wait queue if it cannot be granted
  40  * immediately.  If the lock cannot be granted because of this flag, DLM will
  41  * either return -EAGAIN from the dlm_lock call or will return 0 from
  42  * dlm_lock and -EAGAIN in the lock status block when the AST is executed.
  43  *
  44  * DLM_LKF_CANCEL
  45  *
  46  * Used to cancel a pending lock request or conversion.  A converting lock is
  47  * returned to its previously granted mode.
  48  *
  49  * DLM_LKF_CONVERT
  50  *
  51  * Indicates a lock conversion request.  For conversions the name and namelen
  52  * are ignored and the lock ID in the LKSB is used to identify the lock.
  53  *
  54  * DLM_LKF_VALBLK
  55  *
  56  * Requests DLM to return the current contents of the lock value block in the
  57  * lock status block.  When this flag is set in a lock conversion from PW or EX
  58  * modes, DLM assigns the value specified in the lock status block to the lock
  59  * value block of the lock resource.  The LVB is a DLM_LVB_LEN size array
  60  * containing application-specific information.
  61  *
  62  * DLM_LKF_QUECVT
  63  *
  64  * Force a conversion request to be queued, even if it is compatible with
  65  * the granted modes of other locks on the same resource.
  66  *
  67  * DLM_LKF_IVVALBLK
  68  *
  69  * Invalidate the lock value block.
  70  *
  71  * DLM_LKF_CONVDEADLK
  72  *
  73  * Allows the dlm to resolve conversion deadlocks internally by demoting the
  74  * granted mode of a converting lock to NL.  The DLM_SBF_DEMOTED flag is
  75  * returned for a conversion that's been effected by this.
  76  *
  77  * DLM_LKF_PERSISTENT
  78  *
  79  * Only relevant to locks originating in userspace.  A persistent lock will not
  80  * be removed if the process holding the lock exits.
  81  *
  82  * DLM_LKF_NODLCKWT
  83  *
  84  * Do not cancel the lock if it gets into conversion deadlock.
  85  * Exclude this lock from being monitored due to DLM_LSFL_TIMEWARN.
  86  *
  87  * DLM_LKF_NODLCKBLK
  88  *
  89  * net yet implemented
  90  *
  91  * DLM_LKF_EXPEDITE
  92  *
  93  * Used only with new requests for NL mode locks.  Tells the lock manager
  94  * to grant the lock, ignoring other locks in convert and wait queues.
  95  *
  96  * DLM_LKF_NOQUEUEBAST
  97  *
  98  * Send blocking AST's before returning -EAGAIN to the caller.  It is only
  99  * used along with the NOQUEUE flag.  Blocking AST's are not sent for failed
 100  * NOQUEUE requests otherwise.
 101  *
 102  * DLM_LKF_HEADQUE
 103  *
 104  * Add a lock to the head of the convert or wait queue rather than the tail.
 105  *
 106  * DLM_LKF_NOORDER
 107  *
 108  * Disregard the standard grant order rules and grant a lock as soon as it
 109  * is compatible with other granted locks.
 110  *
 111  * DLM_LKF_ORPHAN
 112  *
 113  * not yet implemented
 114  *
 115  * DLM_LKF_ALTPR
 116  *
 117  * If the requested mode cannot be granted immediately, try to grant the lock
 118  * in PR mode instead.  If this alternate mode is granted instead of the
 119  * requested mode, DLM_SBF_ALTMODE is returned in the lksb.
 120  *
 121  * DLM_LKF_ALTCW
 122  *
 123  * The same as ALTPR, but the alternate mode is CW.
 124  *
 125  * DLM_LKF_FORCEUNLOCK
 126  *
 127  * Unlock the lock even if it is converting or waiting or has sublocks.
 128  * Only really for use by the userland device.c code.
 129  *
 130  */
 131
 132 #define DLM_LKF_NOQUEUE         0x00000001
 133 #define DLM_LKF_CANCEL          0x00000002
 134 #define DLM_LKF_CONVERT         0x00000004
 135 #define DLM_LKF_VALBLK          0x00000008
 136 #define DLM_LKF_QUECVT          0x00000010
 137 #define DLM_LKF_IVVALBLK        0x00000020
 138 #define DLM_LKF_CONVDEADLK      0x00000040
 139 #define DLM_LKF_PERSISTENT      0x00000080
 140 #define DLM_LKF_NODLCKWT        0x00000100
 141 #define DLM_LKF_NODLCKBLK       0x00000200
 142 #define DLM_LKF_EXPEDITE        0x00000400
 143 #define DLM_LKF_NOQUEUEBAST     0x00000800
 144 #define DLM_LKF_HEADQUE         0x00001000
 145 #define DLM_LKF_NOORDER         0x00002000
 146 #define DLM_LKF_ORPHAN          0x00004000
 147 #define DLM_LKF_ALTPR           0x00008000
 148 #define DLM_LKF_ALTCW           0x00010000
 149 #define DLM_LKF_FORCEUNLOCK     0x00020000
 150 #define DLM_LKF_TIMEOUT         0x00040000
 151
 152 /*
 153  * Some return codes that are not in errno.h
 154  */
 155
 156 #define DLM_ECANCEL             0x10001
 157 #define DLM_EUNLOCK             0x10002
 158
 159 #endif  /* __DLMCONSTANTS_DOT_H__ */