dlm.h (6005B)
1/* SPDX-License-Identifier: GPL-2.0-only */ 2/****************************************************************************** 3******************************************************************************* 4** 5** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. 6** Copyright (C) 2004-2011 Red Hat, Inc. All rights reserved. 7** 8** 9******************************************************************************* 10******************************************************************************/ 11#ifndef __DLM_DOT_H__ 12#define __DLM_DOT_H__ 13 14#include <uapi/linux/dlm.h> 15 16 17struct dlm_slot { 18 int nodeid; /* 1 to MAX_INT */ 19 int slot; /* 1 to MAX_INT */ 20}; 21 22/* 23 * recover_prep: called before the dlm begins lock recovery. 24 * Notfies lockspace user that locks from failed members will be granted. 25 * recover_slot: called after recover_prep and before recover_done. 26 * Identifies a failed lockspace member. 27 * recover_done: called after the dlm completes lock recovery. 28 * Identifies lockspace members and lockspace generation number. 29 */ 30 31struct dlm_lockspace_ops { 32 void (*recover_prep) (void *ops_arg); 33 void (*recover_slot) (void *ops_arg, struct dlm_slot *slot); 34 void (*recover_done) (void *ops_arg, struct dlm_slot *slots, 35 int num_slots, int our_slot, uint32_t generation); 36}; 37 38/* 39 * dlm_new_lockspace 40 * 41 * Create/join a lockspace. 42 * 43 * name: lockspace name, null terminated, up to DLM_LOCKSPACE_LEN (not 44 * including terminating null). 45 * 46 * cluster: cluster name, null terminated, up to DLM_LOCKSPACE_LEN (not 47 * including terminating null). Optional. When cluster is null, it 48 * is not used. When set, dlm_new_lockspace() returns -EBADR if cluster 49 * is not equal to the dlm cluster name. 50 * 51 * flags: 52 * DLM_LSFL_NODIR 53 * The dlm should not use a resource directory, but statically assign 54 * resource mastery to nodes based on the name hash that is otherwise 55 * used to select the directory node. Must be the same on all nodes. 56 * DLM_LSFL_TIMEWARN 57 * The dlm should emit netlink messages if locks have been waiting 58 * for a configurable amount of time. (Unused.) 59 * DLM_LSFL_FS 60 * The lockspace user is in the kernel (i.e. filesystem). Enables 61 * direct bast/cast callbacks. 62 * DLM_LSFL_NEWEXCL 63 * dlm_new_lockspace() should return -EEXIST if the lockspace exists. 64 * 65 * lvblen: length of lvb in bytes. Must be multiple of 8. 66 * dlm_new_lockspace() returns an error if this does not match 67 * what other nodes are using. 68 * 69 * ops: callbacks that indicate lockspace recovery points so the 70 * caller can coordinate its recovery and know lockspace members. 71 * This is only used by the initial dlm_new_lockspace() call. 72 * Optional. 73 * 74 * ops_arg: arg for ops callbacks. 75 * 76 * ops_result: tells caller if the ops callbacks (if provided) will 77 * be used or not. 0: will be used, -EXXX will not be used. 78 * -EOPNOTSUPP: the dlm does not have recovery_callbacks enabled. 79 * 80 * lockspace: handle for dlm functions 81 */ 82 83int dlm_new_lockspace(const char *name, const char *cluster, 84 uint32_t flags, int lvblen, 85 const struct dlm_lockspace_ops *ops, void *ops_arg, 86 int *ops_result, dlm_lockspace_t **lockspace); 87 88/* 89 * dlm_release_lockspace 90 * 91 * Stop a lockspace. 92 */ 93 94int dlm_release_lockspace(dlm_lockspace_t *lockspace, int force); 95 96/* 97 * dlm_lock 98 * 99 * Make an asynchronous request to acquire or convert a lock on a named 100 * resource. 101 * 102 * lockspace: context for the request 103 * mode: the requested mode of the lock (DLM_LOCK_) 104 * lksb: lock status block for input and async return values 105 * flags: input flags (DLM_LKF_) 106 * name: name of the resource to lock, can be binary 107 * namelen: the length in bytes of the resource name (MAX_RESNAME_LEN) 108 * parent: the lock ID of a parent lock or 0 if none 109 * lockast: function DLM executes when it completes processing the request 110 * astarg: argument passed to lockast and bast functions 111 * bast: function DLM executes when this lock later blocks another request 112 * 113 * Returns: 114 * 0 if request is successfully queued for processing 115 * -EINVAL if any input parameters are invalid 116 * -EAGAIN if request would block and is flagged DLM_LKF_NOQUEUE 117 * -ENOMEM if there is no memory to process request 118 * -ENOTCONN if there is a communication error 119 * 120 * If the call to dlm_lock returns an error then the operation has failed and 121 * the AST routine will not be called. If dlm_lock returns 0 it is still 122 * possible that the lock operation will fail. The AST routine will be called 123 * when the locking is complete and the status is returned in the lksb. 124 * 125 * If the AST routines or parameter are passed to a conversion operation then 126 * they will overwrite those values that were passed to a previous dlm_lock 127 * call. 128 * 129 * AST routines should not block (at least not for long), but may make 130 * any locking calls they please. 131 */ 132 133int dlm_lock(dlm_lockspace_t *lockspace, 134 int mode, 135 struct dlm_lksb *lksb, 136 uint32_t flags, 137 void *name, 138 unsigned int namelen, 139 uint32_t parent_lkid, 140 void (*lockast) (void *astarg), 141 void *astarg, 142 void (*bast) (void *astarg, int mode)); 143 144/* 145 * dlm_unlock 146 * 147 * Asynchronously release a lock on a resource. The AST routine is called 148 * when the resource is successfully unlocked. 149 * 150 * lockspace: context for the request 151 * lkid: the lock ID as returned in the lksb 152 * flags: input flags (DLM_LKF_) 153 * lksb: if NULL the lksb parameter passed to last lock request is used 154 * astarg: the arg used with the completion ast for the unlock 155 * 156 * Returns: 157 * 0 if request is successfully queued for processing 158 * -EINVAL if any input parameters are invalid 159 * -ENOTEMPTY if the lock still has sublocks 160 * -EBUSY if the lock is waiting for a remote lock operation 161 * -ENOTCONN if there is a communication error 162 */ 163 164int dlm_unlock(dlm_lockspace_t *lockspace, 165 uint32_t lkid, 166 uint32_t flags, 167 struct dlm_lksb *lksb, 168 void *astarg); 169 170#endif /* __DLM_DOT_H__ */