1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
23 /* All Rights Reserved */
24
25
26 /*
27 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
28 * Use is subject to license terms.
29 */
30 /*
31 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
32 */
33
34 #ifndef _SYS_FLOCK_H
35 #define _SYS_FLOCK_H
36
37 #include <sys/types.h>
38 #include <sys/fcntl.h>
39 #include <sys/vnode.h>
40 #include <sys/t_lock.h> /* for <sys/callb.h> */
41 #include <sys/callb.h>
42 #include <sys/param.h>
43 #include <sys/zone.h>
44
45 #ifdef __cplusplus
46 extern "C" {
47 #endif
48
49 /*
50 * Private declarations and instrumentation for local locking.
51 */
52
53 /*
54 * The flag passed to fs_frlock() may be ORed together with either
55 * `F_REMOTELOCK' or `F_PXFSLOCK'. Since this flag is initialized using the
56 * `f_flag' field in the `file' structure, and that field is an unsigned short,
57 * we do not use the first 2 bytes.
58 */
59 #define F_REMOTELOCK (0x01 << 16) /* Set if NLM lock */
60 #define F_PXFSLOCK (0x02 << 16) /* Clustering: set if PXFS lock */
61
62 /*
63 * The command passed to reclock() is made by ORing together one or more of
64 * the following values.
65 */
66
67 #define INOFLCK 0x01 /* Vnode is locked when reclock() is called. */
68 #define SETFLCK 0x02 /* Set a file lock. */
69 #define SLPFLCK 0x04 /* Wait if blocked. */
70 #define RCMDLCK 0x08 /* F_REMOTELOCK specified */
71 #define PCMDLCK 0x10 /* Clustering: F_PXFSLOCK specified */
72 #define NBMLCK 0x20 /* non-blocking mandatory locking */
73
74 /*
75 * Special pid value that can be passed to cleanlocks(). It means that
76 * cleanlocks() should flush all locks for the given sysid, not just the
77 * locks owned by a specific process.
78 */
79
80 #define IGN_PID (-1)
81
82 /* file locking structure (connected to vnode) */
83
84 #define l_end l_len
85
86 /*
87 * The lock manager is allowed to use unsigned offsets and lengths, though
88 * regular Unix processes are still required to use signed offsets and
89 * lengths.
90 */
91 typedef ulong_t u_off_t;
92
93 #define MAX_U_OFF_T ((u_off_t)~0)
94 #define MAX_U_OFFSET_T ((u_offset_t)~0)
95
96 /*
97 * define MAXEND as the largest positive value the signed offset_t will hold.
98 */
99 #define MAXEND MAXOFFSET_T
100
101 /*
102 * Definitions for accessing the l_pad area of struct flock. The
103 * descriminant of the pad_info_t union is the fcntl command used in
104 * conjunction with the flock struct.
105 */
106
107 typedef union {
108 int pi_pad[4]; /* (original pad area) */
109 int pi_has_rmt; /* F_HASREMOTELOCKS */
110 } pad_info_t;
111
112 #define l_has_rmt(flockp) (((pad_info_t *)((flockp)->l_pad))->pi_has_rmt)
113
114 /*
115 * Optional callbacks for blocking lock requests. Each function is called
116 * twice.
117 * The first call is after the request is put in the "sleeping" list, but
118 * before waiting. At most one callback may return a callb_cpr_t object;
119 * the others must return NULL. If a callb_cpr_t is returned, the thread
120 * will be marked as safe to suspend while waiting for the lock.
121 * The second call is after the request wakes up. Note that the request
122 * might not have been granted at the second call (e.g., the request was
123 * signalled).
124 * New callbacks should be added to the head of the list. For the first
125 * call the list is walked in order. For the second call the list is
126 * walked backwards (in case the callbacks need to reacquire locks).
127 */
128
129 typedef enum {FLK_BEFORE_SLEEP, FLK_AFTER_SLEEP} flk_cb_when_t;
130
131 struct flk_callback {
132 struct flk_callback *cb_next; /* circular linked list */
133 struct flk_callback *cb_prev;
134 callb_cpr_t *(*cb_callback)(flk_cb_when_t, void *); /* fcn ptr */
135 void *cb_data; /* ptr to callback data */
136 };
137
138 typedef struct flk_callback flk_callback_t;
139
140 /*
141 * This structure members are not used any more inside the kernel.
142 * The structure is used for casting some pointer assignments only.
143 */
144
145 typedef struct filock {
146 kcondvar_t cv;
147 struct flock set; /* contains type, start, and end */
148 struct {
149 int granted_flag; /* granted flag */
150 struct filock *blk; /* for sleeping locks only */
151 struct attacher *blocking_list;
152 struct attacher *my_attacher;
153 } stat;
154 struct filock *prev;
155 struct filock *next;
156 } filock_t;
157
158 #define FLP_DELAYED_FREE -1 /* special value for granted_flag */
159
160 /* structure that contains list of locks to be granted */
161
162 #define MAX_GRANT_LOCKS 52
163
164 typedef struct grant_lock {
165 struct filock *grant_lock_list[MAX_GRANT_LOCKS];
166 struct grant_lock *next;
167 } grant_lock_t;
168
169 /*
170 * Provide a way to cleanly enable and disable Network Lock Manager locking
171 * requests (i.e., requests from remote clients):
172 * FLK_NLM_SHUTTING_DOWN: Forces all blocked NLM requests to bail out
173 * and return ENOLCK.
174 * FLK_NLM_DOWN: Clears all granted NLM server locks. Both status
175 * codes cause new NLM lock requests to fail immediately with ENOLCK.
176 * FLK_NLM_UP: Changes the state of all locks to UP, after a server has
177 * shutdown and is restarting on the same node.
178 */
179
180 /*
181 * Enumerated type of the four possible states an NLM server can be in.
182 */
183 typedef enum {
184 FLK_NLM_UP,
185 FLK_NLM_SHUTTING_DOWN,
186 FLK_NLM_DOWN,
187 FLK_NLM_UNKNOWN
188 } flk_nlm_status_t;
189
190 /*
191 * Provide a way to cleanly enable and disable lock manager locking
192 * requests (i.e., requests from remote clients). FLK_WAKEUP_SLEEPERS
193 * forces all blocked lock manager requests to bail out and return ENOLCK.
194 * FLK_LOCKMGR_DOWN clears all granted lock manager locks. Both status
195 * codes cause new lock manager requests to fail immediately with ENOLCK.
196 */
197
198 typedef enum {
199 FLK_LOCKMGR_UP,
200 FLK_WAKEUP_SLEEPERS,
201 FLK_LOCKMGR_DOWN
202 } flk_lockmgr_status_t;
203
204 #if defined(_KERNEL)
205
206 /*
207 * The following structure is used to hold a list of locks returned
208 * by the F_ACTIVELIST or F_SLEEPINGLIST commands to fs_frlock.
209 *
210 * N.B. The lists returned by these commands are dynamically
211 * allocated and must be freed by the caller. The vnodes returned
212 * in the lists are held and must be released when the caller is done.
213 */
214
215 typedef struct locklist {
216 struct vnode *ll_vp;
217 struct flock64 ll_flock;
218 struct locklist *ll_next;
219 } locklist_t;
220
221 #define FLK_QUERY_ACTIVE 0x1
222 #define FLK_QUERY_SLEEPING 0x2
223
224 int reclock(struct vnode *, struct flock64 *, int, int, u_offset_t,
225 flk_callback_t *);
226 int chklock(struct vnode *, int, u_offset_t, ssize_t, int,
227 caller_context_t *);
228 int convoff(struct vnode *, struct flock64 *, int, offset_t);
229 void cleanlocks(struct vnode *, pid_t, int);
230 locklist_t *flk_get_sleeping_locks(int sysid, pid_t pid);
231 locklist_t *flk_get_active_locks(int sysid, pid_t pid);
232 locklist_t *flk_active_locks_for_vp(const struct vnode *vp);
233 locklist_t *flk_active_nbmand_locks_for_vp(const struct vnode *vp);
234 locklist_t *flk_active_nbmand_locks(pid_t pid);
235 void flk_free_locklist(locklist_t *);
236 int flk_convert_lock_data(struct vnode *, struct flock64 *,
237 u_offset_t *, u_offset_t *, offset_t);
238 int flk_check_lock_data(u_offset_t, u_offset_t, offset_t);
239 int flk_has_remote_locks(struct vnode *vp);
240 void flk_set_lockmgr_status(flk_lockmgr_status_t status);
241 int flk_sysid_has_locks(int sysid, int chklck);
242 int flk_has_remote_locks_for_sysid(vnode_t *vp, int);
243 void flk_init_callback(flk_callback_t *,
244 callb_cpr_t *(*)(flk_cb_when_t, void *), void *);
245 void flk_add_callback(flk_callback_t *,
246 callb_cpr_t *(*)(flk_cb_when_t, void *), void *,
247 flk_callback_t *);
248 callb_cpr_t *flk_invoke_callbacks(flk_callback_t *, flk_cb_when_t);
249
250 /* Zones hooks */
251 extern zone_key_t flock_zone_key;
252
253 void *flk_zone_init(zoneid_t);
254 void flk_zone_fini(zoneid_t, void *);
255
256 /* Clustering hooks */
257 void cl_flk_set_nlm_status(int nlmid, flk_nlm_status_t nlm_state);
258 void cl_flk_remove_locks_by_sysid(int sysid);
259 int cl_flk_has_remote_locks_for_nlmid(struct vnode *vp, int nlmid);
260 void cl_flk_change_nlm_state_to_unknown(int nlmid);
261 void cl_flk_delete_pxfs_locks(struct vfs *vfsp, int pxfsid);
262 #endif /* _KERNEL */
263
264 #ifdef __cplusplus
265 }
266 #endif
267
268 #endif /* _SYS_FLOCK_H */