xref: /openbmc/linux/include/linux/dlm.h (revision 01c7a597)
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 /*
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 
77 int 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 
88 int 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 
127 int 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 
158 int 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