1/******************************************************************************
2*******************************************************************************
3**
4**  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
5**  Copyright (C) 2004-2011 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#ifndef __DLM_DOT_H__
14#define __DLM_DOT_H__
15
16#include <uapi/linux/dlm.h>
17
18
19struct dlm_slot {
20	int nodeid; /* 1 to MAX_INT */
21	int slot;   /* 1 to MAX_INT */
22};
23
24/*
25 * recover_prep: called before the dlm begins lock recovery.
26 *   Notfies lockspace user that locks from failed members will be granted.
27 * recover_slot: called after recover_prep and before recover_done.
28 *   Identifies a failed lockspace member.
29 * recover_done: called after the dlm completes lock recovery.
30 *   Identifies lockspace members and lockspace generation number.
31 */
32
33struct dlm_lockspace_ops {
34	void (*recover_prep) (void *ops_arg);
35	void (*recover_slot) (void *ops_arg, struct dlm_slot *slot);
36	void (*recover_done) (void *ops_arg, struct dlm_slot *slots,
37			      int num_slots, int our_slot, uint32_t generation);
38};
39
40/*
41 * dlm_new_lockspace
42 *
43 * Create/join a lockspace.
44 *
45 * name: lockspace name, null terminated, up to DLM_LOCKSPACE_LEN (not
46 *   including terminating null).
47 *
48 * cluster: cluster name, null terminated, up to DLM_LOCKSPACE_LEN (not
49 *   including terminating null).  Optional.  When cluster is null, it
50 *   is not used.  When set, dlm_new_lockspace() returns -EBADR if cluster
51 *   is not equal to the dlm cluster name.
52 *
53 * flags:
54 * DLM_LSFL_NODIR
55 *   The dlm should not use a resource directory, but statically assign
56 *   resource mastery to nodes based on the name hash that is otherwise
57 *   used to select the directory node.  Must be the same on all nodes.
58 * DLM_LSFL_TIMEWARN
59 *   The dlm should emit netlink messages if locks have been waiting
60 *   for a configurable amount of time.  (Unused.)
61 * DLM_LSFL_FS
62 *   The lockspace user is in the kernel (i.e. filesystem).  Enables
63 *   direct bast/cast callbacks.
64 * DLM_LSFL_NEWEXCL
65 *   dlm_new_lockspace() should return -EEXIST if the lockspace exists.
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
85int 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
96int 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.
133 */
134
135int dlm_lock(dlm_lockspace_t *lockspace,
136	     int mode,
137	     struct dlm_lksb *lksb,
138	     uint32_t flags,
139	     void *name,
140	     unsigned int namelen,
141	     uint32_t parent_lkid,
142	     void (*lockast) (void *astarg),
143	     void *astarg,
144	     void (*bast) (void *astarg, int mode));
145
146/*
147 * dlm_unlock
148 *
149 * Asynchronously release a lock on a resource.  The AST routine is called
150 * when the resource is successfully unlocked.
151 *
152 * lockspace: context for the request
153 * lkid: the lock ID as returned in the lksb
154 * flags: input flags (DLM_LKF_)
155 * lksb: if NULL the lksb parameter passed to last lock request is used
156 * astarg: the arg used with the completion ast for the unlock
157 *
158 * Returns:
159 * 0 if request is successfully queued for processing
160 * -EINVAL if any input parameters are invalid
161 * -ENOTEMPTY if the lock still has sublocks
162 * -EBUSY if the lock is waiting for a remote lock operation
163 * -ENOTCONN if there is a communication error
164 */
165
166int dlm_unlock(dlm_lockspace_t *lockspace,
167	       uint32_t lkid,
168	       uint32_t flags,
169	       struct dlm_lksb *lksb,
170	       void *astarg);
171
172#endif				/* __DLM_DOT_H__ */
173