1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * dlmapi.h
4  *
5  * externally exported dlm interfaces
6  *
7  * Copyright (C) 2004 Oracle.  All rights reserved.
8  */
9 
10 #ifndef DLMAPI_H
11 #define DLMAPI_H
12 
13 struct dlm_lock;
14 struct dlm_ctxt;
15 
16 /* NOTE: changes made to this enum should be reflected in dlmdebug.c */
17 enum dlm_status {
18 	DLM_NORMAL = 0,           /*  0: request in progress */
19 	DLM_GRANTED,              /*  1: request granted */
20 	DLM_DENIED,               /*  2: request denied */
21 	DLM_DENIED_NOLOCKS,       /*  3: request denied, out of system resources */
22 	DLM_WORKING,              /*  4: async request in progress */
23 	DLM_BLOCKED,              /*  5: lock request blocked */
24 	DLM_BLOCKED_ORPHAN,       /*  6: lock request blocked by a orphan lock*/
25 	DLM_DENIED_GRACE_PERIOD,  /*  7: topological change in progress */
26 	DLM_SYSERR,               /*  8: system error */
27 	DLM_NOSUPPORT,            /*  9: unsupported */
28 	DLM_CANCELGRANT,          /* 10: can't cancel convert: already granted */
29 	DLM_IVLOCKID,             /* 11: bad lockid */
30 	DLM_SYNC,                 /* 12: synchronous request granted */
31 	DLM_BADTYPE,              /* 13: bad resource type */
32 	DLM_BADRESOURCE,          /* 14: bad resource handle */
33 	DLM_MAXHANDLES,           /* 15: no more resource handles */
34 	DLM_NOCLINFO,             /* 16: can't contact cluster manager */
35 	DLM_NOLOCKMGR,            /* 17: can't contact lock manager */
36 	DLM_NOPURGED,             /* 18: can't contact purge daemon */
37 	DLM_BADARGS,              /* 19: bad api args */
38 	DLM_VOID,                 /* 20: no status */
39 	DLM_NOTQUEUED,            /* 21: NOQUEUE was specified and request failed */
40 	DLM_IVBUFLEN,             /* 22: invalid resource name length */
41 	DLM_CVTUNGRANT,           /* 23: attempted to convert ungranted lock */
42 	DLM_BADPARAM,             /* 24: invalid lock mode specified */
43 	DLM_VALNOTVALID,          /* 25: value block has been invalidated */
44 	DLM_REJECTED,             /* 26: request rejected, unrecognized client */
45 	DLM_ABORT,                /* 27: blocked lock request cancelled */
46 	DLM_CANCEL,               /* 28: conversion request cancelled */
47 	DLM_IVRESHANDLE,          /* 29: invalid resource handle */
48 	DLM_DEADLOCK,             /* 30: deadlock recovery refused this request */
49 	DLM_DENIED_NOASTS,        /* 31: failed to allocate AST */
50 	DLM_FORWARD,              /* 32: request must wait for primary's response */
51 	DLM_TIMEOUT,              /* 33: timeout value for lock has expired */
52 	DLM_IVGROUPID,            /* 34: invalid group specification */
53 	DLM_VERS_CONFLICT,        /* 35: version conflicts prevent request handling */
54 	DLM_BAD_DEVICE_PATH,      /* 36: Locks device does not exist or path wrong */
55 	DLM_NO_DEVICE_PERMISSION, /* 37: Client has insufficient pers for device */
56 	DLM_NO_CONTROL_DEVICE,    /* 38: Cannot set options on opened device */
57 
58 	DLM_RECOVERING,           /* 39: extension, allows caller to fail a lock
59 				     request if it is being recovered */
60 	DLM_MIGRATING,            /* 40: extension, allows caller to fail a lock
61 				     request if it is being migrated */
62 	DLM_MAXSTATS,             /* 41: upper limit for return code validation */
63 };
64 
65 /* for pretty-printing dlm_status error messages */
66 const char *dlm_errmsg(enum dlm_status err);
67 /* for pretty-printing dlm_status error names */
68 const char *dlm_errname(enum dlm_status err);
69 
70 /* Eventually the DLM will use standard errno values, but in the
71  * meantime this lets us track dlm errors as they bubble up. When we
72  * bring its error reporting into line with the rest of the stack,
73  * these can just be replaced with calls to mlog_errno. */
74 #define dlm_error(st) do {						\
75 	if ((st) != DLM_RECOVERING &&					\
76 	    (st) != DLM_MIGRATING &&					\
77 	    (st) != DLM_FORWARD)					\
78 		mlog(ML_ERROR, "dlm status = %s\n", dlm_errname((st)));	\
79 } while (0)
80 
81 #define DLM_LKSB_UNUSED1           0x01
82 #define DLM_LKSB_PUT_LVB           0x02
83 #define DLM_LKSB_GET_LVB           0x04
84 #define DLM_LKSB_UNUSED2           0x08
85 #define DLM_LKSB_UNUSED3           0x10
86 #define DLM_LKSB_UNUSED4           0x20
87 #define DLM_LKSB_UNUSED5           0x40
88 #define DLM_LKSB_UNUSED6           0x80
89 
90 #define DLM_LVB_LEN  64
91 
92 /* Callers are only allowed access to the lvb and status members of
93  * this struct. */
94 struct dlm_lockstatus {
95 	enum dlm_status status;
96 	u32 flags;
97 	struct dlm_lock *lockid;
98 	char lvb[DLM_LVB_LEN];
99 };
100 
101 /* Valid lock modes. */
102 #define LKM_IVMODE      (-1)            /* invalid mode */
103 #define LKM_NLMODE      0               /* null lock */
104 #define LKM_CRMODE      1               /* concurrent read    unsupported */
105 #define LKM_CWMODE      2               /* concurrent write   unsupported */
106 #define LKM_PRMODE      3               /* protected read */
107 #define LKM_PWMODE      4               /* protected write    unsupported */
108 #define LKM_EXMODE      5               /* exclusive */
109 #define LKM_MAXMODE     5
110 #define LKM_MODEMASK    0xff
111 
112 /* Flags passed to dlmlock and dlmunlock:
113  * reserved: flags used by the "real" dlm
114  * only a few are supported by this dlm
115  * (U) = unsupported by ocfs2 dlm */
116 #define LKM_ORPHAN       0x00000010  /* this lock is orphanable (U) */
117 #define LKM_PARENTABLE   0x00000020  /* this lock was orphaned (U) */
118 #define LKM_BLOCK        0x00000040  /* blocking lock request (U) */
119 #define LKM_LOCAL        0x00000080  /* local lock request */
120 #define LKM_VALBLK       0x00000100  /* lock value block request */
121 #define LKM_NOQUEUE      0x00000200  /* non blocking request */
122 #define LKM_CONVERT      0x00000400  /* conversion request */
123 #define LKM_NODLCKWT     0x00000800  /* this lock wont deadlock (U) */
124 #define LKM_UNLOCK       0x00001000  /* deallocate this lock */
125 #define LKM_CANCEL       0x00002000  /* cancel conversion request */
126 #define LKM_DEQALL       0x00004000  /* remove all locks held by proc (U) */
127 #define LKM_INVVALBLK    0x00008000  /* invalidate lock value block */
128 #define LKM_SYNCSTS      0x00010000  /* return synchronous status if poss (U) */
129 #define LKM_TIMEOUT      0x00020000  /* lock request contains timeout (U) */
130 #define LKM_SNGLDLCK     0x00040000  /* request can self-deadlock (U) */
131 #define LKM_FINDLOCAL    0x00080000  /* find local lock request (U) */
132 #define LKM_PROC_OWNED   0x00100000  /* owned by process, not group (U) */
133 #define LKM_XID          0x00200000  /* use transaction id for deadlock (U) */
134 #define LKM_XID_CONFLICT 0x00400000  /* do not allow lock inheritance (U) */
135 #define LKM_FORCE        0x00800000  /* force unlock flag */
136 #define LKM_REVVALBLK    0x01000000  /* temporary solution: re-validate
137 					lock value block (U) */
138 /* unused */
139 #define LKM_UNUSED1      0x00000001  /* unused */
140 #define LKM_UNUSED2      0x00000002  /* unused */
141 #define LKM_UNUSED3      0x00000004  /* unused */
142 #define LKM_UNUSED4      0x00000008  /* unused */
143 #define LKM_UNUSED5      0x02000000  /* unused */
144 #define LKM_UNUSED6      0x04000000  /* unused */
145 #define LKM_UNUSED7      0x08000000  /* unused */
146 
147 /* ocfs2 extensions: internal only
148  * should never be used by caller */
149 #define LKM_MIGRATION    0x10000000  /* extension: lockres is to be migrated
150 					to another node */
151 #define LKM_PUT_LVB      0x20000000  /* extension: lvb is being passed
152 					should be applied to lockres */
153 #define LKM_GET_LVB      0x40000000  /* extension: lvb should be copied
154 					from lockres when lock is granted */
155 #define LKM_RECOVERY     0x80000000  /* extension: flag for recovery lock
156 					used to avoid recovery rwsem */
157 
158 
159 typedef void (dlm_astlockfunc_t)(void *);
160 typedef void (dlm_bastlockfunc_t)(void *, int);
161 typedef void (dlm_astunlockfunc_t)(void *, enum dlm_status);
162 
163 enum dlm_status dlmlock(struct dlm_ctxt *dlm,
164 			int mode,
165 			struct dlm_lockstatus *lksb,
166 			int flags,
167 			const char *name,
168 			int namelen,
169 			dlm_astlockfunc_t *ast,
170 			void *data,
171 			dlm_bastlockfunc_t *bast);
172 
173 enum dlm_status dlmunlock(struct dlm_ctxt *dlm,
174 			  struct dlm_lockstatus *lksb,
175 			  int flags,
176 			  dlm_astunlockfunc_t *unlockast,
177 			  void *data);
178 
179 struct dlm_protocol_version {
180 	u8 pv_major;
181 	u8 pv_minor;
182 };
183 struct dlm_ctxt * dlm_register_domain(const char *domain, u32 key,
184 				      struct dlm_protocol_version *fs_proto);
185 
186 void dlm_unregister_domain(struct dlm_ctxt *dlm);
187 
188 void dlm_print_one_lock(struct dlm_lock *lockid);
189 
190 typedef void (dlm_eviction_func)(int, void *);
191 struct dlm_eviction_cb {
192 	struct list_head        ec_item;
193 	dlm_eviction_func       *ec_func;
194 	void                    *ec_data;
195 };
196 void dlm_setup_eviction_cb(struct dlm_eviction_cb *cb,
197 			   dlm_eviction_func *f,
198 			   void *data);
199 void dlm_register_eviction_cb(struct dlm_ctxt *dlm,
200 			      struct dlm_eviction_cb *cb);
201 void dlm_unregister_eviction_cb(struct dlm_eviction_cb *cb);
202 
203 #endif /* DLMAPI_H */
204