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David Teiglande7fd4172006-01-18 09:30:29 +00001/******************************************************************************
2*******************************************************************************
3**
4** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
David Teigland60f98d12011-11-02 14:30:58 -05005** Copyright (C) 2004-2011 Red Hat, Inc. All rights reserved.
David Teiglande7fd4172006-01-18 09:30:29 +00006**
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
Joel Beckerd69a3ad2007-10-05 14:31:44 -070022/* Lock levels and flags are here */
23#include <linux/dlmconstants.h>
Mike Frysingerc1c76742008-04-21 11:35:39 -050024#include <linux/types.h>
David Teiglande7fd4172006-01-18 09:30:29 +000025
David Teiglande7fd4172006-01-18 09:30:29 +000026typedef void dlm_lockspace_t;
27
28/*
David Teiglande7fd4172006-01-18 09:30:29 +000029 * 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
David Teiglande7fd4172006-01-18 09:30:29 +000051 * -DLM_EUNLOCK if unlock request was successful
52 * -DLM_ECANCEL if a cancel completed successfully
Steven Whitehouse269cddd2010-09-07 14:17:10 -050053 * -EDEADLK if a deadlock was detected
54 * -ETIMEDOUT if the lock request was canceled due to a timeout
David Teiglande7fd4172006-01-18 09:30:29 +000055 */
56
57#define DLM_SBF_DEMOTED 0x01
58#define DLM_SBF_VALNOTVALID 0x02
59#define DLM_SBF_ALTMODE 0x04
60
61struct dlm_lksb {
62 int sb_status;
Mike Frysingerc1c76742008-04-21 11:35:39 -050063 __u32 sb_lkid;
David Teiglande7fd4172006-01-18 09:30:29 +000064 char sb_flags;
65 char * sb_lvbptr;
66};
67
David Teigland0f8e0d92008-08-06 13:30:24 -050068/* dlm_new_lockspace() flags */
69
David Teigland3ae1acf2007-05-18 08:59:31 -050070#define DLM_LSFL_NODIR 0x00000001
71#define DLM_LSFL_TIMEWARN 0x00000002
Patrick Caulfield44f487a2007-06-06 09:21:22 -050072#define DLM_LSFL_FS 0x00000004
David Teigland0f8e0d92008-08-06 13:30:24 -050073#define DLM_LSFL_NEWEXCL 0x00000008
David Teiglande7fd4172006-01-18 09:30:29 +000074
75#ifdef __KERNEL__
76
David Teigland60f98d12011-11-02 14:30:58 -050077struct dlm_slot {
78 int nodeid; /* 1 to MAX_INT */
79 int slot; /* 1 to MAX_INT */
80};
81
82/*
83 * recover_prep: called before the dlm begins lock recovery.
84 * Notfies lockspace user that locks from failed members will be granted.
85 * recover_slot: called after recover_prep and before recover_done.
86 * Identifies a failed lockspace member.
87 * recover_done: called after the dlm completes lock recovery.
88 * Identifies lockspace members and lockspace generation number.
89 */
90
91struct dlm_lockspace_ops {
92 void (*recover_prep) (void *ops_arg);
93 void (*recover_slot) (void *ops_arg, struct dlm_slot *slot);
94 void (*recover_done) (void *ops_arg, struct dlm_slot *slots,
95 int num_slots, int our_slot, uint32_t generation);
96};
97
David Teiglande7fd4172006-01-18 09:30:29 +000098/*
99 * dlm_new_lockspace
100 *
David Teigland60f98d12011-11-02 14:30:58 -0500101 * Create/join a lockspace.
102 *
103 * name: lockspace name, null terminated, up to DLM_LOCKSPACE_LEN (not
104 * including terminating null).
105 *
106 * cluster: cluster name, null terminated, up to DLM_LOCKSPACE_LEN (not
107 * including terminating null). Optional. When cluster is null, it
108 * is not used. When set, dlm_new_lockspace() returns -EBADR if cluster
109 * is not equal to the dlm cluster name.
110 *
111 * flags:
112 * DLM_LSFL_NODIR
113 * The dlm should not use a resource directory, but statically assign
114 * resource mastery to nodes based on the name hash that is otherwise
115 * used to select the directory node. Must be the same on all nodes.
116 * DLM_LSFL_TIMEWARN
117 * The dlm should emit netlink messages if locks have been waiting
118 * for a configurable amount of time. (Unused.)
119 * DLM_LSFL_FS
120 * The lockspace user is in the kernel (i.e. filesystem). Enables
121 * direct bast/cast callbacks.
122 * DLM_LSFL_NEWEXCL
123 * dlm_new_lockspace() should return -EEXIST if the lockspace exists.
124 *
125 * lvblen: length of lvb in bytes. Must be multiple of 8.
126 * dlm_new_lockspace() returns an error if this does not match
127 * what other nodes are using.
128 *
129 * ops: callbacks that indicate lockspace recovery points so the
130 * caller can coordinate its recovery and know lockspace members.
131 * This is only used by the initial dlm_new_lockspace() call.
132 * Optional.
133 *
134 * ops_arg: arg for ops callbacks.
135 *
136 * ops_result: tells caller if the ops callbacks (if provided) will
137 * be used or not. 0: will be used, -EXXX will not be used.
138 * -EOPNOTSUPP: the dlm does not have recovery_callbacks enabled.
139 *
140 * lockspace: handle for dlm functions
David Teiglande7fd4172006-01-18 09:30:29 +0000141 */
142
David Teigland60f98d12011-11-02 14:30:58 -0500143int dlm_new_lockspace(const char *name, const char *cluster,
144 uint32_t flags, int lvblen,
145 const struct dlm_lockspace_ops *ops, void *ops_arg,
146 int *ops_result, dlm_lockspace_t **lockspace);
David Teiglande7fd4172006-01-18 09:30:29 +0000147
148/*
149 * dlm_release_lockspace
150 *
151 * Stop a lockspace.
152 */
153
154int dlm_release_lockspace(dlm_lockspace_t *lockspace, int force);
155
156/*
157 * dlm_lock
158 *
159 * Make an asyncronous request to acquire or convert a lock on a named
160 * resource.
161 *
162 * lockspace: context for the request
163 * mode: the requested mode of the lock (DLM_LOCK_)
164 * lksb: lock status block for input and async return values
165 * flags: input flags (DLM_LKF_)
166 * name: name of the resource to lock, can be binary
167 * namelen: the length in bytes of the resource name (MAX_RESNAME_LEN)
168 * parent: the lock ID of a parent lock or 0 if none
169 * lockast: function DLM executes when it completes processing the request
170 * astarg: argument passed to lockast and bast functions
171 * bast: function DLM executes when this lock later blocks another request
172 *
173 * Returns:
174 * 0 if request is successfully queued for processing
175 * -EINVAL if any input parameters are invalid
176 * -EAGAIN if request would block and is flagged DLM_LKF_NOQUEUE
177 * -ENOMEM if there is no memory to process request
178 * -ENOTCONN if there is a communication error
179 *
180 * If the call to dlm_lock returns an error then the operation has failed and
181 * the AST routine will not be called. If dlm_lock returns 0 it is still
182 * possible that the lock operation will fail. The AST routine will be called
183 * when the locking is complete and the status is returned in the lksb.
184 *
185 * If the AST routines or parameter are passed to a conversion operation then
186 * they will overwrite those values that were passed to a previous dlm_lock
187 * call.
188 *
189 * AST routines should not block (at least not for long), but may make
190 * any locking calls they please.
191 */
192
193int dlm_lock(dlm_lockspace_t *lockspace,
194 int mode,
195 struct dlm_lksb *lksb,
196 uint32_t flags,
197 void *name,
198 unsigned int namelen,
199 uint32_t parent_lkid,
200 void (*lockast) (void *astarg),
201 void *astarg,
David Teigland3bcd3682006-02-23 09:56:38 +0000202 void (*bast) (void *astarg, int mode));
David Teiglande7fd4172006-01-18 09:30:29 +0000203
204/*
205 * dlm_unlock
206 *
207 * Asynchronously release a lock on a resource. The AST routine is called
208 * when the resource is successfully unlocked.
209 *
210 * lockspace: context for the request
211 * lkid: the lock ID as returned in the lksb
212 * flags: input flags (DLM_LKF_)
213 * lksb: if NULL the lksb parameter passed to last lock request is used
214 * astarg: the arg used with the completion ast for the unlock
215 *
216 * Returns:
217 * 0 if request is successfully queued for processing
218 * -EINVAL if any input parameters are invalid
219 * -ENOTEMPTY if the lock still has sublocks
220 * -EBUSY if the lock is waiting for a remote lock operation
221 * -ENOTCONN if there is a communication error
222 */
223
224int dlm_unlock(dlm_lockspace_t *lockspace,
225 uint32_t lkid,
226 uint32_t flags,
227 struct dlm_lksb *lksb,
228 void *astarg);
229
230#endif /* __KERNEL__ */
231
232#endif /* __DLM_DOT_H__ */
233