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 __DLM_DOT_H__ 15 #define __DLM_DOT_H__ 16 17 /* 18 * Interface to Distributed Lock Manager (DLM) 19 * routines and structures to use DLM lockspaces 20 */ 21 22 /* 23 * Lock Modes 24 */ 25 26 #define DLM_LOCK_IV -1 /* invalid */ 27 #define DLM_LOCK_NL 0 /* null */ 28 #define DLM_LOCK_CR 1 /* concurrent read */ 29 #define DLM_LOCK_CW 2 /* concurrent write */ 30 #define DLM_LOCK_PR 3 /* protected read */ 31 #define DLM_LOCK_PW 4 /* protected write */ 32 #define DLM_LOCK_EX 5 /* exclusive */ 33 34 /* 35 * Maximum size in bytes of a dlm_lock name 36 */ 37 38 #define DLM_RESNAME_MAXLEN 64 39 40 /* 41 * Flags to dlm_lock 42 * 43 * DLM_LKF_NOQUEUE 44 * 45 * Do not queue the lock request on the wait queue if it cannot be granted 46 * immediately. If the lock cannot be granted because of this flag, DLM will 47 * either return -EAGAIN from the dlm_lock call or will return 0 from 48 * dlm_lock and -EAGAIN in the lock status block when the AST is executed. 49 * 50 * DLM_LKF_CANCEL 51 * 52 * Used to cancel a pending lock request or conversion. A converting lock is 53 * returned to its previously granted mode. 54 * 55 * DLM_LKF_CONVERT 56 * 57 * Indicates a lock conversion request. For conversions the name and namelen 58 * are ignored and the lock ID in the LKSB is used to identify the lock. 59 * 60 * DLM_LKF_VALBLK 61 * 62 * Requests DLM to return the current contents of the lock value block in the 63 * lock status block. When this flag is set in a lock conversion from PW or EX 64 * modes, DLM assigns the value specified in the lock status block to the lock 65 * value block of the lock resource. The LVB is a DLM_LVB_LEN size array 66 * containing application-specific information. 67 * 68 * DLM_LKF_QUECVT 69 * 70 * Force a conversion request to be queued, even if it is compatible with 71 * the granted modes of other locks on the same resource. 72 * 73 * DLM_LKF_IVVALBLK 74 * 75 * Invalidate the lock value block. 76 * 77 * DLM_LKF_CONVDEADLK 78 * 79 * Allows the dlm to resolve conversion deadlocks internally by demoting the 80 * granted mode of a converting lock to NL. The DLM_SBF_DEMOTED flag is 81 * returned for a conversion that's been effected by this. 82 * 83 * DLM_LKF_PERSISTENT 84 * 85 * Only relevant to locks originating in userspace. A persistent lock will not 86 * be removed if the process holding the lock exits. 87 * 88 * DLM_LKF_NODLCKWT 89 * 90 * Do not cancel the lock if it gets into conversion deadlock. 91 * Exclude this lock from being monitored due to DLM_LSFL_TIMEWARN. 92 * 93 * DLM_LKF_NODLCKBLK 94 * 95 * net yet implemented 96 * 97 * DLM_LKF_EXPEDITE 98 * 99 * Used only with new requests for NL mode locks. Tells the lock manager 100 * to grant the lock, ignoring other locks in convert and wait queues. 101 * 102 * DLM_LKF_NOQUEUEBAST 103 * 104 * Send blocking AST's before returning -EAGAIN to the caller. It is only 105 * used along with the NOQUEUE flag. Blocking AST's are not sent for failed 106 * NOQUEUE requests otherwise. 107 * 108 * DLM_LKF_HEADQUE 109 * 110 * Add a lock to the head of the convert or wait queue rather than the tail. 111 * 112 * DLM_LKF_NOORDER 113 * 114 * Disregard the standard grant order rules and grant a lock as soon as it 115 * is compatible with other granted locks. 116 * 117 * DLM_LKF_ORPHAN 118 * 119 * not yet implemented 120 * 121 * DLM_LKF_ALTPR 122 * 123 * If the requested mode cannot be granted immediately, try to grant the lock 124 * in PR mode instead. If this alternate mode is granted instead of the 125 * requested mode, DLM_SBF_ALTMODE is returned in the lksb. 126 * 127 * DLM_LKF_ALTCW 128 * 129 * The same as ALTPR, but the alternate mode is CW. 130 * 131 * DLM_LKF_FORCEUNLOCK 132 * 133 * Unlock the lock even if it is converting or waiting or has sublocks. 134 * Only really for use by the userland device.c code. 135 * 136 */ 137 138 #define DLM_LKF_NOQUEUE 0x00000001 139 #define DLM_LKF_CANCEL 0x00000002 140 #define DLM_LKF_CONVERT 0x00000004 141 #define DLM_LKF_VALBLK 0x00000008 142 #define DLM_LKF_QUECVT 0x00000010 143 #define DLM_LKF_IVVALBLK 0x00000020 144 #define DLM_LKF_CONVDEADLK 0x00000040 145 #define DLM_LKF_PERSISTENT 0x00000080 146 #define DLM_LKF_NODLCKWT 0x00000100 147 #define DLM_LKF_NODLCKBLK 0x00000200 148 #define DLM_LKF_EXPEDITE 0x00000400 149 #define DLM_LKF_NOQUEUEBAST 0x00000800 150 #define DLM_LKF_HEADQUE 0x00001000 151 #define DLM_LKF_NOORDER 0x00002000 152 #define DLM_LKF_ORPHAN 0x00004000 153 #define DLM_LKF_ALTPR 0x00008000 154 #define DLM_LKF_ALTCW 0x00010000 155 #define DLM_LKF_FORCEUNLOCK 0x00020000 156 #define DLM_LKF_TIMEOUT 0x00040000 157 158 /* 159 * Some return codes that are not in errno.h 160 */ 161 162 #define DLM_ECANCEL 0x10001 163 #define DLM_EUNLOCK 0x10002 164 165 typedef void dlm_lockspace_t; 166 167 /* 168 * Lock status block 169 * 170 * Use this structure to specify the contents of the lock value block. For a 171 * conversion request, this structure is used to specify the lock ID of the 172 * lock. DLM writes the status of the lock request and the lock ID assigned 173 * to the request in the lock status block. 174 * 175 * sb_lkid: the returned lock ID. It is set on new (non-conversion) requests. 176 * It is available when dlm_lock returns. 177 * 178 * sb_lvbptr: saves or returns the contents of the lock's LVB according to rules 179 * shown for the DLM_LKF_VALBLK flag. 180 * 181 * sb_flags: DLM_SBF_DEMOTED is returned if in the process of promoting a lock, 182 * it was first demoted to NL to avoid conversion deadlock. 183 * DLM_SBF_VALNOTVALID is returned if the resource's LVB is marked invalid. 184 * 185 * sb_status: the returned status of the lock request set prior to AST 186 * execution. Possible return values: 187 * 188 * 0 if lock request was successful 189 * -EAGAIN if request would block and is flagged DLM_LKF_NOQUEUE 190 * -ENOMEM if there is no memory to process request 191 * -EINVAL if there are invalid parameters 192 * -DLM_EUNLOCK if unlock request was successful 193 * -DLM_ECANCEL if a cancel completed successfully 194 */ 195 196 #define DLM_SBF_DEMOTED 0x01 197 #define DLM_SBF_VALNOTVALID 0x02 198 #define DLM_SBF_ALTMODE 0x04 199 200 struct dlm_lksb { 201 int sb_status; 202 uint32_t sb_lkid; 203 char sb_flags; 204 char * sb_lvbptr; 205 }; 206 207 #define DLM_LSFL_NODIR 0x00000001 208 #define DLM_LSFL_TIMEWARN 0x00000002 209 #define DLM_LSFL_FS 0x00000004 210 211 212 #endif /* __DLM_DOT_H__ */ 213 214
