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 #include <linux/types.h> 25 26 typedef 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 * -ENOMEM if there is no memory to process request 52 * -EINVAL if there are invalid parameters 53 * -DLM_EUNLOCK if unlock request was successful 54 * -DLM_ECANCEL if a cancel completed successfully 55 */ 56 57 #define DLM_SBF_DEMOTED 0x01 58 #define DLM_SBF_VALNOTVALID 0x02 59 #define DLM_SBF_ALTMODE 0x04 60 61 struct dlm_lksb { 62 int sb_status; 63 __u32 sb_lkid; 64 char sb_flags; 65 char * sb_lvbptr; 66 }; 67 68 #define DLM_LSFL_NODIR 0x00000001 69 #define DLM_LSFL_TIMEWARN 0x00000002 70 #define DLM_LSFL_FS 0x00000004 71 72 #ifdef __KERNEL__ 73 74 /* 75 * dlm_new_lockspace 76 * 77 * Starts a lockspace with the given name. If the named lockspace exists in 78 * the cluster, the calling node joins it. 79 */ 80 81 int dlm_new_lockspace(char *name, int namelen, dlm_lockspace_t **lockspace, 82 uint32_t flags, int lvblen); 83 84 /* 85 * dlm_release_lockspace 86 * 87 * Stop a lockspace. 88 */ 89 90 int dlm_release_lockspace(dlm_lockspace_t *lockspace, int force); 91 92 /* 93 * dlm_lock 94 * 95 * Make an asyncronous request to acquire or convert a lock on a named 96 * resource. 97 * 98 * lockspace: context for the request 99 * mode: the requested mode of the lock (DLM_LOCK_) 100 * lksb: lock status block for input and async return values 101 * flags: input flags (DLM_LKF_) 102 * name: name of the resource to lock, can be binary 103 * namelen: the length in bytes of the resource name (MAX_RESNAME_LEN) 104 * parent: the lock ID of a parent lock or 0 if none 105 * lockast: function DLM executes when it completes processing the request 106 * astarg: argument passed to lockast and bast functions 107 * bast: function DLM executes when this lock later blocks another request 108 * 109 * Returns: 110 * 0 if request is successfully queued for processing 111 * -EINVAL if any input parameters are invalid 112 * -EAGAIN if request would block and is flagged DLM_LKF_NOQUEUE 113 * -ENOMEM if there is no memory to process request 114 * -ENOTCONN if there is a communication error 115 * 116 * If the call to dlm_lock returns an error then the operation has failed and 117 * the AST routine will not be called. If dlm_lock returns 0 it is still 118 * possible that the lock operation will fail. The AST routine will be called 119 * when the locking is complete and the status is returned in the lksb. 120 * 121 * If the AST routines or parameter are passed to a conversion operation then 122 * they will overwrite those values that were passed to a previous dlm_lock 123 * call. 124 * 125 * AST routines should not block (at least not for long), but may make 126 * any locking calls they please. 127 */ 128 129 int dlm_lock(dlm_lockspace_t *lockspace, 130 int mode, 131 struct dlm_lksb *lksb, 132 uint32_t flags, 133 void *name, 134 unsigned int namelen, 135 uint32_t parent_lkid, 136 void (*lockast) (void *astarg), 137 void *astarg, 138 void (*bast) (void *astarg, int mode)); 139 140 /* 141 * dlm_unlock 142 * 143 * Asynchronously release a lock on a resource. The AST routine is called 144 * when the resource is successfully unlocked. 145 * 146 * lockspace: context for the request 147 * lkid: the lock ID as returned in the lksb 148 * flags: input flags (DLM_LKF_) 149 * lksb: if NULL the lksb parameter passed to last lock request is used 150 * astarg: the arg used with the completion ast for the unlock 151 * 152 * Returns: 153 * 0 if request is successfully queued for processing 154 * -EINVAL if any input parameters are invalid 155 * -ENOTEMPTY if the lock still has sublocks 156 * -EBUSY if the lock is waiting for a remote lock operation 157 * -ENOTCONN if there is a communication error 158 */ 159 160 int dlm_unlock(dlm_lockspace_t *lockspace, 161 uint32_t lkid, 162 uint32_t flags, 163 struct dlm_lksb *lksb, 164 void *astarg); 165 166 #endif /* __KERNEL__ */ 167 168 #endif /* __DLM_DOT_H__ */ 169 170