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 17 struct 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 31 struct 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 /* only relevant for kernel lockspaces, will be removed in future */ 39 #define DLM_LSFL_SOFTIRQ __DLM_LSFL_RESERVED0 40 41 /* 42 * dlm_new_lockspace 43 * 44 * Create/join a lockspace. 45 * 46 * name: lockspace name, null terminated, up to DLM_LOCKSPACE_LEN (not 47 * including terminating null). 48 * 49 * cluster: cluster name, null terminated, up to DLM_LOCKSPACE_LEN (not 50 * including terminating null). Optional. When cluster is null, it 51 * is not used. When set, dlm_new_lockspace() returns -EBADR if cluster 52 * is not equal to the dlm cluster name. 53 * 54 * flags: 55 * DLM_LSFL_NODIR 56 * The dlm should not use a resource directory, but statically assign 57 * resource mastery to nodes based on the name hash that is otherwise 58 * used to select the directory node. Must be the same on all nodes. 59 * DLM_LSFL_NEWEXCL 60 * dlm_new_lockspace() should return -EEXIST if the lockspace exists. 61 * DLM_LSFL_SOFTIRQ 62 * dlm request callbacks (ast, bast) are softirq safe. Flag should be 63 * preferred by users. Will be default in some future. If set the 64 * strongest context for ast, bast callback is softirq as it avoids 65 * an additional context switch. 66 * 67 * lvblen: length of lvb in bytes. Must be multiple of 8. 68 * dlm_new_lockspace() returns an error if this does not match 69 * what other nodes are using. 70 * 71 * ops: callbacks that indicate lockspace recovery points so the 72 * caller can coordinate its recovery and know lockspace members. 73 * This is only used by the initial dlm_new_lockspace() call. 74 * Optional. 75 * 76 * ops_arg: arg for ops callbacks. 77 * 78 * ops_result: tells caller if the ops callbacks (if provided) will 79 * be used or not. 0: will be used, -EXXX will not be used. 80 * -EOPNOTSUPP: the dlm does not have recovery_callbacks enabled. 81 * 82 * lockspace: handle for dlm functions 83 */ 84 85 int dlm_new_lockspace(const char *name, const char *cluster, 86 uint32_t flags, int lvblen, 87 const struct dlm_lockspace_ops *ops, void *ops_arg, 88 int *ops_result, dlm_lockspace_t **lockspace); 89 90 /* 91 * dlm_release_lockspace() release_option values: 92 * 93 * DLM_RELEASE_NO_LOCKS returns -EBUSY if any locks (lkb's) 94 * exist in the local lockspace. 95 * 96 * DLM_RELEASE_UNUSED previous value that is no longer used. 97 * 98 * DLM_RELEASE_NORMAL releases the lockspace regardless of any 99 * locks managed in the local lockspace. 100 * 101 * DLM_RELEASE_NO_EVENT release the lockspace regardless of any 102 * locks managed in the local lockspace, and does not submit 103 * a leave event to the cluster manager, so other nodes will 104 * not be notified that the node should be removed from the 105 * list of lockspace members. 106 * 107 * DLM_RELEASE_RECOVER like DLM_RELEASE_NORMAL, but the remaining 108 * nodes will handle the removal of the node as if the node 109 * had failed, e.g. the recover_slot() callback would be used. 110 */ 111 #define DLM_RELEASE_NO_LOCKS 0 112 #define DLM_RELEASE_UNUSED 1 113 #define DLM_RELEASE_NORMAL 2 114 #define DLM_RELEASE_NO_EVENT 3 115 #define DLM_RELEASE_RECOVER 4 116 #define __DLM_RELEASE_MAX DLM_RELEASE_RECOVER 117 118 /* 119 * dlm_release_lockspace 120 * 121 * Stop a lockspace. 122 * 123 * release_option: see DLM_RELEASE values above. 124 */ 125 126 int dlm_release_lockspace(dlm_lockspace_t *lockspace, 127 unsigned int release_option); 128 129 /* 130 * dlm_lock 131 * 132 * Make an asynchronous request to acquire or convert a lock on a named 133 * resource. 134 * 135 * lockspace: context for the request 136 * mode: the requested mode of the lock (DLM_LOCK_) 137 * lksb: lock status block for input and async return values 138 * flags: input flags (DLM_LKF_) 139 * name: name of the resource to lock, can be binary 140 * namelen: the length in bytes of the resource name (MAX_RESNAME_LEN) 141 * parent: the lock ID of a parent lock or 0 if none 142 * lockast: function DLM executes when it completes processing the request 143 * astarg: argument passed to lockast and bast functions 144 * bast: function DLM executes when this lock later blocks another request 145 * 146 * Returns: 147 * 0 if request is successfully queued for processing 148 * -EINVAL if any input parameters are invalid 149 * -EAGAIN if request would block and is flagged DLM_LKF_NOQUEUE 150 * -ENOMEM if there is no memory to process request 151 * -ENOTCONN if there is a communication error 152 * 153 * If the call to dlm_lock returns an error then the operation has failed and 154 * the AST routine will not be called. If dlm_lock returns 0 it is still 155 * possible that the lock operation will fail. The AST routine will be called 156 * when the locking is complete and the status is returned in the lksb. 157 * 158 * If the AST routines or parameter are passed to a conversion operation then 159 * they will overwrite those values that were passed to a previous dlm_lock 160 * call. 161 * 162 * AST routines should not block (at least not for long), but may make 163 * any locking calls they please. If DLM_LSFL_SOFTIRQ for kernel 164 * users of dlm_new_lockspace() is passed the ast and bast callbacks 165 * can be processed in softirq context. Also some of the callback 166 * contexts are in the same context as the DLM lock request API, users 167 * must not hold locks while calling dlm lock request API and trying 168 * to acquire this lock in the callback again, this will end in a 169 * lock recursion. For newer implementation the DLM_LSFL_SOFTIRQ 170 * should be used. 171 */ 172 173 int dlm_lock(dlm_lockspace_t *lockspace, 174 int mode, 175 struct dlm_lksb *lksb, 176 uint32_t flags, 177 const void *name, 178 unsigned int namelen, 179 uint32_t parent_lkid, 180 void (*lockast) (void *astarg), 181 void *astarg, 182 void (*bast) (void *astarg, int mode)); 183 184 /* 185 * dlm_unlock 186 * 187 * Asynchronously release a lock on a resource. The AST routine is called 188 * when the resource is successfully unlocked. 189 * 190 * lockspace: context for the request 191 * lkid: the lock ID as returned in the lksb 192 * flags: input flags (DLM_LKF_) 193 * lksb: if NULL the lksb parameter passed to last lock request is used 194 * astarg: the arg used with the completion ast for the unlock 195 * 196 * Returns: 197 * 0 if request is successfully queued for processing 198 * -EINVAL if any input parameters are invalid 199 * -ENOTEMPTY if the lock still has sublocks 200 * -EBUSY if the lock is waiting for a remote lock operation 201 * -ENOTCONN if there is a communication error 202 */ 203 204 int dlm_unlock(dlm_lockspace_t *lockspace, 205 uint32_t lkid, 206 uint32_t flags, 207 struct dlm_lksb *lksb, 208 void *astarg); 209 210 #endif /* __DLM_DOT_H__ */ 211