1/****************************************************************************** 2******************************************************************************* 3** 4** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. 5** Copyright (C) 2004-2008 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/* Lock levels and flags are here */ 23#include <linux/dlmconstants.h> 24#include <linux/types.h> 25 26typedef void dlm_lockspace_t; 27 28/* 29 * Lock status block 30 * 31 * Use this structure to specify the contents of the lock value block. For a 32 * conversion request, this structure is used to specify the lock ID of the 33 * lock. DLM writes the status of the lock request and the lock ID assigned 34 * to the request in the lock status block. 35 * 36 * sb_lkid: the returned lock ID. It is set on new (non-conversion) requests. 37 * It is available when dlm_lock returns. 38 * 39 * sb_lvbptr: saves or returns the contents of the lock's LVB according to rules 40 * shown for the DLM_LKF_VALBLK flag. 41 * 42 * sb_flags: DLM_SBF_DEMOTED is returned if in the process of promoting a lock, 43 * it was first demoted to NL to avoid conversion deadlock. 44 * DLM_SBF_VALNOTVALID is returned if the resource's LVB is marked invalid. 45 * 46 * sb_status: the returned status of the lock request set prior to AST 47 * execution. Possible return values: 48 * 49 * 0 if lock request was successful 50 * -EAGAIN if request would block and is flagged DLM_LKF_NOQUEUE 51 * -DLM_EUNLOCK if unlock request was successful 52 * -DLM_ECANCEL if a cancel completed successfully 53 * -EDEADLK if a deadlock was detected 54 * -ETIMEDOUT if the lock request was canceled due to a timeout 55 */ 56 57#define DLM_SBF_DEMOTED 0x01 58#define DLM_SBF_VALNOTVALID 0x02 59#define DLM_SBF_ALTMODE 0x04 60 61struct dlm_lksb { 62 int sb_status; 63 __u32 sb_lkid; 64 char sb_flags; 65 char * sb_lvbptr; 66}; 67 68/* dlm_new_lockspace() flags */ 69 70#define DLM_LSFL_NODIR 0x00000001 71#define DLM_LSFL_TIMEWARN 0x00000002 72#define DLM_LSFL_FS 0x00000004 73#define DLM_LSFL_NEWEXCL 0x00000008 74 75#ifdef __KERNEL__ 76 77/* 78 * dlm_new_lockspace 79 * 80 * Starts a lockspace with the given name. If the named lockspace exists in 81 * the cluster, the calling node joins it. 82 */ 83 84int dlm_new_lockspace(const char *name, int namelen, 85 dlm_lockspace_t **lockspace, uint32_t flags, int lvblen); 86 87/* 88 * dlm_release_lockspace 89 * 90 * Stop a lockspace. 91 */ 92 93int dlm_release_lockspace(dlm_lockspace_t *lockspace, int force); 94 95/* 96 * dlm_lock 97 * 98 * Make an asyncronous request to acquire or convert a lock on a named 99 * resource. 100 * 101 * lockspace: context for the request 102 * mode: the requested mode of the lock (DLM_LOCK_) 103 * lksb: lock status block for input and async return values 104 * flags: input flags (DLM_LKF_) 105 * name: name of the resource to lock, can be binary 106 * namelen: the length in bytes of the resource name (MAX_RESNAME_LEN) 107 * parent: the lock ID of a parent lock or 0 if none 108 * lockast: function DLM executes when it completes processing the request 109 * astarg: argument passed to lockast and bast functions 110 * bast: function DLM executes when this lock later blocks another request 111 * 112 * Returns: 113 * 0 if request is successfully queued for processing 114 * -EINVAL if any input parameters are invalid 115 * -EAGAIN if request would block and is flagged DLM_LKF_NOQUEUE 116 * -ENOMEM if there is no memory to process request 117 * -ENOTCONN if there is a communication error 118 * 119 * If the call to dlm_lock returns an error then the operation has failed and 120 * the AST routine will not be called. If dlm_lock returns 0 it is still 121 * possible that the lock operation will fail. The AST routine will be called 122 * when the locking is complete and the status is returned in the lksb. 123 * 124 * If the AST routines or parameter are passed to a conversion operation then 125 * they will overwrite those values that were passed to a previous dlm_lock 126 * call. 127 * 128 * AST routines should not block (at least not for long), but may make 129 * any locking calls they please. 130 */ 131 132int dlm_lock(dlm_lockspace_t *lockspace, 133 int mode, 134 struct dlm_lksb *lksb, 135 uint32_t flags, 136 void *name, 137 unsigned int namelen, 138 uint32_t parent_lkid, 139 void (*lockast) (void *astarg), 140 void *astarg, 141 void (*bast) (void *astarg, int mode)); 142 143/* 144 * dlm_unlock 145 * 146 * Asynchronously release a lock on a resource. The AST routine is called 147 * when the resource is successfully unlocked. 148 * 149 * lockspace: context for the request 150 * lkid: the lock ID as returned in the lksb 151 * flags: input flags (DLM_LKF_) 152 * lksb: if NULL the lksb parameter passed to last lock request is used 153 * astarg: the arg used with the completion ast for the unlock 154 * 155 * Returns: 156 * 0 if request is successfully queued for processing 157 * -EINVAL if any input parameters are invalid 158 * -ENOTEMPTY if the lock still has sublocks 159 * -EBUSY if the lock is waiting for a remote lock operation 160 * -ENOTCONN if there is a communication error 161 */ 162 163int dlm_unlock(dlm_lockspace_t *lockspace, 164 uint32_t lkid, 165 uint32_t flags, 166 struct dlm_lksb *lksb, 167 void *astarg); 168 169#endif /* __KERNEL__ */ 170 171#endif /* __DLM_DOT_H__ */ 172 173