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