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
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