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1 | /****************************************************************************** |
2 | ******************************************************************************* | |
3 | ** | |
4 | ** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. | |
5 | ** Copyright (C) 2004-2005 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 | /* | |
23 | * Lock Modes | |
24 | */ | |
25 | ||
26 | #define DLM_LOCK_IV -1 /* invalid */ | |
27 | #define DLM_LOCK_NL 0 /* null */ | |
28 | #define DLM_LOCK_CR 1 /* concurrent read */ | |
29 | #define DLM_LOCK_CW 2 /* concurrent write */ | |
30 | #define DLM_LOCK_PR 3 /* protected read */ | |
31 | #define DLM_LOCK_PW 4 /* protected write */ | |
32 | #define DLM_LOCK_EX 5 /* exclusive */ | |
33 | ||
34 | /* | |
35 | * Maximum size in bytes of a dlm_lock name | |
36 | */ | |
37 | ||
38 | #define DLM_RESNAME_MAXLEN 64 | |
39 | ||
40 | /* | |
41 | * Flags to dlm_lock | |
42 | * | |
43 | * DLM_LKF_NOQUEUE | |
44 | * | |
45 | * Do not queue the lock request on the wait queue if it cannot be granted | |
46 | * immediately. If the lock cannot be granted because of this flag, DLM will | |
47 | * either return -EAGAIN from the dlm_lock call or will return 0 from | |
48 | * dlm_lock and -EAGAIN in the lock status block when the AST is executed. | |
49 | * | |
50 | * DLM_LKF_CANCEL | |
51 | * | |
52 | * Used to cancel a pending lock request or conversion. A converting lock is | |
53 | * returned to its previously granted mode. | |
54 | * | |
55 | * DLM_LKF_CONVERT | |
56 | * | |
57 | * Indicates a lock conversion request. For conversions the name and namelen | |
58 | * are ignored and the lock ID in the LKSB is used to identify the lock. | |
59 | * | |
60 | * DLM_LKF_VALBLK | |
61 | * | |
62 | * Requests DLM to return the current contents of the lock value block in the | |
63 | * lock status block. When this flag is set in a lock conversion from PW or EX | |
64 | * modes, DLM assigns the value specified in the lock status block to the lock | |
65 | * value block of the lock resource. The LVB is a DLM_LVB_LEN size array | |
66 | * containing application-specific information. | |
67 | * | |
68 | * DLM_LKF_QUECVT | |
69 | * | |
70 | * Force a conversion request to be queued, even if it is compatible with | |
71 | * the granted modes of other locks on the same resource. | |
72 | * | |
73 | * DLM_LKF_IVVALBLK | |
74 | * | |
75 | * Invalidate the lock value block. | |
76 | * | |
77 | * DLM_LKF_CONVDEADLK | |
78 | * | |
79 | * Allows the dlm to resolve conversion deadlocks internally by demoting the | |
80 | * granted mode of a converting lock to NL. The DLM_SBF_DEMOTED flag is | |
81 | * returned for a conversion that's been effected by this. | |
82 | * | |
83 | * DLM_LKF_PERSISTENT | |
84 | * | |
85 | * Only relevant to locks originating in userspace. A persistent lock will not | |
86 | * be removed if the process holding the lock exits. | |
87 | * | |
88 | * DLM_LKF_NODLKWT | |
89 | * DLM_LKF_NODLCKBLK | |
90 | * | |
91 | * net yet implemented | |
92 | * | |
93 | * DLM_LKF_EXPEDITE | |
94 | * | |
95 | * Used only with new requests for NL mode locks. Tells the lock manager | |
96 | * to grant the lock, ignoring other locks in convert and wait queues. | |
97 | * | |
98 | * DLM_LKF_NOQUEUEBAST | |
99 | * | |
100 | * Send blocking AST's before returning -EAGAIN to the caller. It is only | |
101 | * used along with the NOQUEUE flag. Blocking AST's are not sent for failed | |
102 | * NOQUEUE requests otherwise. | |
103 | * | |
104 | * DLM_LKF_HEADQUE | |
105 | * | |
106 | * Add a lock to the head of the convert or wait queue rather than the tail. | |
107 | * | |
108 | * DLM_LKF_NOORDER | |
109 | * | |
110 | * Disregard the standard grant order rules and grant a lock as soon as it | |
111 | * is compatible with other granted locks. | |
112 | * | |
113 | * DLM_LKF_ORPHAN | |
114 | * | |
115 | * not yet implemented | |
116 | * | |
117 | * DLM_LKF_ALTPR | |
118 | * | |
119 | * If the requested mode cannot be granted immediately, try to grant the lock | |
120 | * in PR mode instead. If this alternate mode is granted instead of the | |
121 | * requested mode, DLM_SBF_ALTMODE is returned in the lksb. | |
122 | * | |
123 | * DLM_LKF_ALTCW | |
124 | * | |
125 | * The same as ALTPR, but the alternate mode is CW. | |
126 | * | |
127 | * DLM_LKF_FORCEUNLOCK | |
128 | * | |
129 | * Unlock the lock even if it is converting or waiting or has sublocks. | |
130 | * Only really for use by the userland device.c code. | |
131 | * | |
132 | */ | |
133 | ||
134 | #define DLM_LKF_NOQUEUE 0x00000001 | |
135 | #define DLM_LKF_CANCEL 0x00000002 | |
136 | #define DLM_LKF_CONVERT 0x00000004 | |
137 | #define DLM_LKF_VALBLK 0x00000008 | |
138 | #define DLM_LKF_QUECVT 0x00000010 | |
139 | #define DLM_LKF_IVVALBLK 0x00000020 | |
140 | #define DLM_LKF_CONVDEADLK 0x00000040 | |
141 | #define DLM_LKF_PERSISTENT 0x00000080 | |
142 | #define DLM_LKF_NODLCKWT 0x00000100 | |
143 | #define DLM_LKF_NODLCKBLK 0x00000200 | |
144 | #define DLM_LKF_EXPEDITE 0x00000400 | |
145 | #define DLM_LKF_NOQUEUEBAST 0x00000800 | |
146 | #define DLM_LKF_HEADQUE 0x00001000 | |
147 | #define DLM_LKF_NOORDER 0x00002000 | |
148 | #define DLM_LKF_ORPHAN 0x00004000 | |
149 | #define DLM_LKF_ALTPR 0x00008000 | |
150 | #define DLM_LKF_ALTCW 0x00010000 | |
151 | #define DLM_LKF_FORCEUNLOCK 0x00020000 | |
152 | ||
153 | /* | |
154 | * Some return codes that are not in errno.h | |
155 | */ | |
156 | ||
157 | #define DLM_ECANCEL 0x10001 | |
158 | #define DLM_EUNLOCK 0x10002 | |
159 | ||
160 | typedef void dlm_lockspace_t; | |
161 | ||
e7fd4179 DT |
162 | /* |
163 | * Lock status block | |
164 | * | |
165 | * Use this structure to specify the contents of the lock value block. For a | |
166 | * conversion request, this structure is used to specify the lock ID of the | |
167 | * lock. DLM writes the status of the lock request and the lock ID assigned | |
168 | * to the request in the lock status block. | |
169 | * | |
170 | * sb_lkid: the returned lock ID. It is set on new (non-conversion) requests. | |
171 | * It is available when dlm_lock returns. | |
172 | * | |
173 | * sb_lvbptr: saves or returns the contents of the lock's LVB according to rules | |
174 | * shown for the DLM_LKF_VALBLK flag. | |
175 | * | |
176 | * sb_flags: DLM_SBF_DEMOTED is returned if in the process of promoting a lock, | |
177 | * it was first demoted to NL to avoid conversion deadlock. | |
178 | * DLM_SBF_VALNOTVALID is returned if the resource's LVB is marked invalid. | |
179 | * | |
180 | * sb_status: the returned status of the lock request set prior to AST | |
181 | * execution. Possible return values: | |
182 | * | |
183 | * 0 if lock request was successful | |
184 | * -EAGAIN if request would block and is flagged DLM_LKF_NOQUEUE | |
185 | * -ENOMEM if there is no memory to process request | |
186 | * -EINVAL if there are invalid parameters | |
187 | * -DLM_EUNLOCK if unlock request was successful | |
188 | * -DLM_ECANCEL if a cancel completed successfully | |
189 | */ | |
190 | ||
191 | #define DLM_SBF_DEMOTED 0x01 | |
192 | #define DLM_SBF_VALNOTVALID 0x02 | |
193 | #define DLM_SBF_ALTMODE 0x04 | |
194 | ||
195 | struct dlm_lksb { | |
196 | int sb_status; | |
197 | uint32_t sb_lkid; | |
198 | char sb_flags; | |
199 | char * sb_lvbptr; | |
200 | }; | |
201 | ||
202 | ||
203 | #ifdef __KERNEL__ | |
204 | ||
205 | #define DLM_LSFL_NODIR 0x00000001 | |
206 | ||
207 | /* | |
208 | * dlm_new_lockspace | |
209 | * | |
210 | * Starts a lockspace with the given name. If the named lockspace exists in | |
211 | * the cluster, the calling node joins it. | |
212 | */ | |
213 | ||
214 | int dlm_new_lockspace(char *name, int namelen, dlm_lockspace_t **lockspace, | |
215 | uint32_t flags, int lvblen); | |
216 | ||
217 | /* | |
218 | * dlm_release_lockspace | |
219 | * | |
220 | * Stop a lockspace. | |
221 | */ | |
222 | ||
223 | int dlm_release_lockspace(dlm_lockspace_t *lockspace, int force); | |
224 | ||
225 | /* | |
226 | * dlm_lock | |
227 | * | |
228 | * Make an asyncronous request to acquire or convert a lock on a named | |
229 | * resource. | |
230 | * | |
231 | * lockspace: context for the request | |
232 | * mode: the requested mode of the lock (DLM_LOCK_) | |
233 | * lksb: lock status block for input and async return values | |
234 | * flags: input flags (DLM_LKF_) | |
235 | * name: name of the resource to lock, can be binary | |
236 | * namelen: the length in bytes of the resource name (MAX_RESNAME_LEN) | |
237 | * parent: the lock ID of a parent lock or 0 if none | |
238 | * lockast: function DLM executes when it completes processing the request | |
239 | * astarg: argument passed to lockast and bast functions | |
240 | * bast: function DLM executes when this lock later blocks another request | |
241 | * | |
242 | * Returns: | |
243 | * 0 if request is successfully queued for processing | |
244 | * -EINVAL if any input parameters are invalid | |
245 | * -EAGAIN if request would block and is flagged DLM_LKF_NOQUEUE | |
246 | * -ENOMEM if there is no memory to process request | |
247 | * -ENOTCONN if there is a communication error | |
248 | * | |
249 | * If the call to dlm_lock returns an error then the operation has failed and | |
250 | * the AST routine will not be called. If dlm_lock returns 0 it is still | |
251 | * possible that the lock operation will fail. The AST routine will be called | |
252 | * when the locking is complete and the status is returned in the lksb. | |
253 | * | |
254 | * If the AST routines or parameter are passed to a conversion operation then | |
255 | * they will overwrite those values that were passed to a previous dlm_lock | |
256 | * call. | |
257 | * | |
258 | * AST routines should not block (at least not for long), but may make | |
259 | * any locking calls they please. | |
260 | */ | |
261 | ||
262 | int dlm_lock(dlm_lockspace_t *lockspace, | |
263 | int mode, | |
264 | struct dlm_lksb *lksb, | |
265 | uint32_t flags, | |
266 | void *name, | |
267 | unsigned int namelen, | |
268 | uint32_t parent_lkid, | |
269 | void (*lockast) (void *astarg), | |
270 | void *astarg, | |
3bcd3687 | 271 | void (*bast) (void *astarg, int mode)); |
e7fd4179 DT |
272 | |
273 | /* | |
274 | * dlm_unlock | |
275 | * | |
276 | * Asynchronously release a lock on a resource. The AST routine is called | |
277 | * when the resource is successfully unlocked. | |
278 | * | |
279 | * lockspace: context for the request | |
280 | * lkid: the lock ID as returned in the lksb | |
281 | * flags: input flags (DLM_LKF_) | |
282 | * lksb: if NULL the lksb parameter passed to last lock request is used | |
283 | * astarg: the arg used with the completion ast for the unlock | |
284 | * | |
285 | * Returns: | |
286 | * 0 if request is successfully queued for processing | |
287 | * -EINVAL if any input parameters are invalid | |
288 | * -ENOTEMPTY if the lock still has sublocks | |
289 | * -EBUSY if the lock is waiting for a remote lock operation | |
290 | * -ENOTCONN if there is a communication error | |
291 | */ | |
292 | ||
293 | int dlm_unlock(dlm_lockspace_t *lockspace, | |
294 | uint32_t lkid, | |
295 | uint32_t flags, | |
296 | struct dlm_lksb *lksb, | |
297 | void *astarg); | |
298 | ||
299 | #endif /* __KERNEL__ */ | |
300 | ||
301 | #endif /* __DLM_DOT_H__ */ | |
302 |