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_NEWEXCL
57 *   dlm_new_lockspace() should return -EEXIST if the lockspace exists.
58 *
59 * lvblen: length of lvb in bytes.  Must be multiple of 8.
60 *   dlm_new_lockspace() returns an error if this does not match
61 *   what other nodes are using.
62 *
63 * ops: callbacks that indicate lockspace recovery points so the
64 *   caller can coordinate its recovery and know lockspace members.
65 *   This is only used by the initial dlm_new_lockspace() call.
66 *   Optional.
67 *
68 * ops_arg: arg for ops callbacks.
69 *
70 * ops_result: tells caller if the ops callbacks (if provided) will
71 *   be used or not.  0: will be used, -EXXX will not be used.
72 *   -EOPNOTSUPP: the dlm does not have recovery_callbacks enabled.
73 *
74 * lockspace: handle for dlm functions
75 */
76
77int dlm_new_lockspace(const char *name, const char *cluster,
78		      uint32_t flags, int lvblen,
79		      const struct dlm_lockspace_ops *ops, void *ops_arg,
80		      int *ops_result, dlm_lockspace_t **lockspace);
81
82/*
83 * dlm_release_lockspace
84 *
85 * Stop a lockspace.
86 */
87
88int dlm_release_lockspace(dlm_lockspace_t *lockspace, int force);
89
90/*
91 * dlm_lock
92 *
93 * Make an asynchronous request to acquire or convert a lock on a named
94 * resource.
95 *
96 * lockspace: context for the request
97 * mode: the requested mode of the lock (DLM_LOCK_)
98 * lksb: lock status block for input and async return values
99 * flags: input flags (DLM_LKF_)
100 * name: name of the resource to lock, can be binary
101 * namelen: the length in bytes of the resource name (MAX_RESNAME_LEN)
102 * parent: the lock ID of a parent lock or 0 if none
103 * lockast: function DLM executes when it completes processing the request
104 * astarg: argument passed to lockast and bast functions
105 * bast: function DLM executes when this lock later blocks another request
106 *
107 * Returns:
108 * 0 if request is successfully queued for processing
109 * -EINVAL if any input parameters are invalid
110 * -EAGAIN if request would block and is flagged DLM_LKF_NOQUEUE
111 * -ENOMEM if there is no memory to process request
112 * -ENOTCONN if there is a communication error
113 *
114 * If the call to dlm_lock returns an error then the operation has failed and
115 * the AST routine will not be called.  If dlm_lock returns 0 it is still
116 * possible that the lock operation will fail. The AST routine will be called
117 * when the locking is complete and the status is returned in the lksb.
118 *
119 * If the AST routines or parameter are passed to a conversion operation then
120 * they will overwrite those values that were passed to a previous dlm_lock
121 * call.
122 *
123 * AST routines should not block (at least not for long), but may make
124 * any locking calls they please.
125 */
126
127int dlm_lock(dlm_lockspace_t *lockspace,
128	     int mode,
129	     struct dlm_lksb *lksb,
130	     uint32_t flags,
131	     const void *name,
132	     unsigned int namelen,
133	     uint32_t parent_lkid,
134	     void (*lockast) (void *astarg),
135	     void *astarg,
136	     void (*bast) (void *astarg, int mode));
137
138/*
139 * dlm_unlock
140 *
141 * Asynchronously release a lock on a resource.  The AST routine is called
142 * when the resource is successfully unlocked.
143 *
144 * lockspace: context for the request
145 * lkid: the lock ID as returned in the lksb
146 * flags: input flags (DLM_LKF_)
147 * lksb: if NULL the lksb parameter passed to last lock request is used
148 * astarg: the arg used with the completion ast for the unlock
149 *
150 * Returns:
151 * 0 if request is successfully queued for processing
152 * -EINVAL if any input parameters are invalid
153 * -ENOTEMPTY if the lock still has sublocks
154 * -EBUSY if the lock is waiting for a remote lock operation
155 * -ENOTCONN if there is a communication error
156 */
157
158int dlm_unlock(dlm_lockspace_t *lockspace,
159	       uint32_t lkid,
160	       uint32_t flags,
161	       struct dlm_lksb *lksb,
162	       void *astarg);
163
164#endif				/* __DLM_DOT_H__ */
165