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 92 * 93 * Stop a lockspace. 94 */ 95 96 int dlm_release_lockspace(dlm_lockspace_t *lockspace, int force); 97 98 /* 99 * dlm_lock 100 * 101 * Make an asynchronous request to acquire or convert a lock on a named 102 * resource. 103 * 104 * lockspace: context for the request 105 * mode: the requested mode of the lock (DLM_LOCK_) 106 * lksb: lock status block for input and async return values 107 * flags: input flags (DLM_LKF_) 108 * name: name of the resource to lock, can be binary 109 * namelen: the length in bytes of the resource name (MAX_RESNAME_LEN) 110 * parent: the lock ID of a parent lock or 0 if none 111 * lockast: function DLM executes when it completes processing the request 112 * astarg: argument passed to lockast and bast functions 113 * bast: function DLM executes when this lock later blocks another request 114 * 115 * Returns: 116 * 0 if request is successfully queued for processing 117 * -EINVAL if any input parameters are invalid 118 * -EAGAIN if request would block and is flagged DLM_LKF_NOQUEUE 119 * -ENOMEM if there is no memory to process request 120 * -ENOTCONN if there is a communication error 121 * 122 * If the call to dlm_lock returns an error then the operation has failed and 123 * the AST routine will not be called. If dlm_lock returns 0 it is still 124 * possible that the lock operation will fail. The AST routine will be called 125 * when the locking is complete and the status is returned in the lksb. 126 * 127 * If the AST routines or parameter are passed to a conversion operation then 128 * they will overwrite those values that were passed to a previous dlm_lock 129 * call. 130 * 131 * AST routines should not block (at least not for long), but may make 132 * any locking calls they please. If DLM_LSFL_SOFTIRQ for kernel 133 * users of dlm_new_lockspace() is passed the ast and bast callbacks 134 * can be processed in softirq context. Also some of the callback 135 * contexts are in the same context as the DLM lock request API, users 136 * must not hold locks while calling dlm lock request API and trying 137 * to acquire this lock in the callback again, this will end in a 138 * lock recursion. For newer implementation the DLM_LSFL_SOFTIRQ 139 * should be used. 140 */ 141 142 int dlm_lock(dlm_lockspace_t *lockspace, 143 int mode, 144 struct dlm_lksb *lksb, 145 uint32_t flags, 146 const void *name, 147 unsigned int namelen, 148 uint32_t parent_lkid, 149 void (*lockast) (void *astarg), 150 void *astarg, 151 void (*bast) (void *astarg, int mode)); 152 153 /* 154 * dlm_unlock 155 * 156 * Asynchronously release a lock on a resource. The AST routine is called 157 * when the resource is successfully unlocked. 158 * 159 * lockspace: context for the request 160 * lkid: the lock ID as returned in the lksb 161 * flags: input flags (DLM_LKF_) 162 * lksb: if NULL the lksb parameter passed to last lock request is used 163 * astarg: the arg used with the completion ast for the unlock 164 * 165 * Returns: 166 * 0 if request is successfully queued for processing 167 * -EINVAL if any input parameters are invalid 168 * -ENOTEMPTY if the lock still has sublocks 169 * -EBUSY if the lock is waiting for a remote lock operation 170 * -ENOTCONN if there is a communication error 171 */ 172 173 int dlm_unlock(dlm_lockspace_t *lockspace, 174 uint32_t lkid, 175 uint32_t flags, 176 struct dlm_lksb *lksb, 177 void *astarg); 178 179 #endif /* __DLM_DOT_H__ */ 180