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 /*
23 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 * Copyright 2015 Joyent, Inc.
26 */
27
28 #ifndef _SYS_FLOCK_IMPL_H
29 #define _SYS_FLOCK_IMPL_H
30
31 #include <sys/types.h>
32 #include <sys/fcntl.h> /* flock definition */
33 #include <sys/file.h> /* FREAD etc */
34 #include <sys/flock.h> /* RCMD etc */
35 #include <sys/kmem.h>
36 #include <sys/user.h>
37 #include <sys/thread.h>
38 #include <sys/proc.h>
39 #include <sys/cred.h>
40 #include <sys/debug.h>
41 #include <sys/cmn_err.h>
42 #include <sys/errno.h>
43 #include <sys/systm.h>
44 #include <sys/vnode.h>
45 #include <sys/share.h> /* just to get GETSYSID def */
46
47 #ifdef __cplusplus
48 extern "C" {
49 #endif
50
51 struct edge {
52 struct edge *edge_adj_next; /* adjacency list next */
53 struct edge *edge_adj_prev; /* adjacency list prev */
54 struct edge *edge_in_next; /* incoming edges list next */
55 struct edge *edge_in_prev; /* incoming edges list prev */
56 struct lock_descriptor *from_vertex; /* edge emanating from lock */
57 struct lock_descriptor *to_vertex; /* edge pointing to lock */
58 };
59
60 typedef struct edge edge_t;
61
62 struct lock_descriptor {
63 struct lock_descriptor *l_next; /* next active/sleep lock */
64 struct lock_descriptor *l_prev; /* previous active/sleep lock */
65 struct edge l_edge; /* edge for adj and in lists */
66 struct lock_descriptor *l_stack; /* for stack operations */
67 struct lock_descriptor *l_stack1; /* for stack operations */
68 struct lock_descriptor *l_dstack; /* stack for debug functions */
69 struct edge *l_sedge; /* start edge for graph alg. */
70 int l_index; /* used for barrier count */
71 struct graph *l_graph; /* graph this belongs to */
72 vnode_t *l_vnode; /* vnode being locked */
73 int l_type; /* type of lock */
74 int l_state; /* state described below */
75 u_offset_t l_start; /* start offset */
76 u_offset_t l_end; /* end offset */
77 flock64_t l_flock; /* original flock request */
78 int l_color; /* color used for graph alg */
79 kcondvar_t l_cv; /* wait condition for lock */
80 int pvertex; /* index to proc vertex */
81 int l_status; /* status described below */
82 flk_nlm_status_t l_nlm_state; /* state of NLM server */
83 flk_callback_t *l_callbacks; /* callbacks, or NULL */
84 zoneid_t l_zoneid; /* zone of request */
85 file_t *l_ofd; /* OFD-style reference */
86 };
87
88 typedef struct lock_descriptor lock_descriptor_t;
89
90 /*
91 * Each graph holds locking information for some number of vnodes. The
92 * active and sleeping lists are circular, with a dummy head element.
93 */
94
95 struct graph {
96 kmutex_t gp_mutex; /* mutex for this graph */
97 struct lock_descriptor active_locks;
98 struct lock_descriptor sleeping_locks;
99 int index; /* index of this graph into the hash table */
100 int mark; /* used for coloring the graph */
101 };
102
103 typedef struct graph graph_t;
104
105 /*
106 * The possible states a lock can be in. These states are stored in the
107 * 'l_status' member of the 'lock_descriptor_t' structure. All locks start
108 * life in the INITIAL state, and end up in the DEAD state. Possible state
109 * transitions are :
110 *
111 * INITIAL--> START --> ACTIVE --> DEAD
112 *
113 * --> DEAD
114 *
115 * --> ACTIVE --> DEAD (new locks from flk_relation)
116 *
117 * --> SLEEPING --> GRANTED --> START --> ACTIVE --> DEAD
118 *
119 * --> INTR --> DEAD
120 *
121 * --> CANCELLED --> DEAD
122 *
123 * --> INTR --> DEAD
124 *
125 * --> INTR --> DEAD
126 *
127 * --> CANCELLED --> DEAD
128 *
129 * --> INTR --> DEAD
130 *
131 * Lock transitions are done in the following functions:
132 * --> INITIAL flk_get_lock(), reclock()
133 * --> START flk_execute_request()
134 * --> ACTIVE flk_insert_active_lock()
135 * --> SLEEPING flk_insert_sleeping_lock()
136 * --> GRANTED GRANT_WAKEUP
137 * --> INTERRUPTED INTERRUPT_WAKEUP
138 * --> CANCELLED CANCEL_WAKEUP
139 * --> DEAD reclock(), flk_delete_active_lock(), and
140 * flk_cancel_sleeping_lock()
141 */
142
143 #define FLK_INITIAL_STATE 1 /* Initial state of all requests */
144 #define FLK_START_STATE 2 /* Request has started execution */
145 #define FLK_ACTIVE_STATE 3 /* In active queue */
146 #define FLK_SLEEPING_STATE 4 /* Request is blocked */
147 #define FLK_GRANTED_STATE 5 /* Request is granted */
148 #define FLK_INTERRUPTED_STATE 6 /* Request is interrupted */
149 #define FLK_CANCELLED_STATE 7 /* Request is cancelled */
150 #define FLK_DEAD_STATE 8 /* Request is done - will be deleted */
151
152 /* flags defining state of locks */
153
154 /*
155 * The LLM design has been modified so that lock states are now stored
156 * in the l_status field of lock_descriptor_t. The l_state field is
157 * currently preserved for binary compatibility, but may be modified or
158 * removed in a minor release of Solaris. Note that both of these
159 * fields (and the rest of the lock_descriptor_t structure) are private
160 * to the implementation of the lock manager and should not be used
161 * externally.
162 */
163
164 #define ACTIVE_LOCK 0x0001 /* in active queue */
165 #define SLEEPING_LOCK 0x0002 /* in sleep queue */
166 #define IO_LOCK 0x0004 /* is an IO lock */
167 #define REFERENCED_LOCK 0x0008 /* referenced some where */
168 #define QUERY_LOCK 0x0010 /* querying about lock */
169 #define WILLING_TO_SLEEP_LOCK 0x0020 /* lock can be put in sleep queue */
170 #define RECOMPUTE_LOCK 0x0040 /* used for recomputing dependencies */
171 #define RECOMPUTE_DONE 0x0080 /* used for recomputing dependencies */
172 #define BARRIER_LOCK 0x0100 /* used for recomputing dependencies */
173 #define GRANTED_LOCK 0x0200 /* granted but still in sleep queue */
174 #define CANCELLED_LOCK 0x0400 /* cancelled will be thrown out */
175 #define DELETED_LOCK 0x0800 /* deleted - free at earliest */
176 #define INTERRUPTED_LOCK 0x1000 /* pretend signal */
177 #define LOCKMGR_LOCK 0x2000 /* remote lock (server-side) */
178 /* Clustering: flag for PXFS locks */
179 #define PXFS_LOCK 0x4000 /* lock created by PXFS file system */
180 #define NBMAND_LOCK 0x8000 /* non-blocking mandatory locking */
181
182 #define HASH_SIZE 32
183 #define HASH_SHIFT (HASH_SIZE - 1)
184 #define HASH_INDEX(vp) (((uintptr_t)vp >> 7) & HASH_SHIFT)
185
186 /* extern definitions */
187
188 extern struct graph *lock_graph[HASH_SIZE];
189 extern struct kmem_cache *flk_edge_cache;
190
191 /* Clustering: functions called by PXFS */
192 int flk_execute_request(lock_descriptor_t *);
193 void flk_cancel_sleeping_lock(lock_descriptor_t *, int);
194 void flk_set_state(lock_descriptor_t *, int);
195 graph_t *flk_get_lock_graph(vnode_t *, int);
196
197 /* flags used for readability in flock.c */
198
199 #define FLK_USE_GRAPH 0 /* don't initialize the lock_graph */
200 #define FLK_INIT_GRAPH 1 /* initialize the lock graph */
201 #define NO_COLOR 0 /* vertex is not colored */
202 #define NO_CHECK_CYCLE 0 /* don't mark vertex's in flk_add_edge */
203 #define CHECK_CYCLE 1 /* mark vertex's in flk_add_edge */
204
205 #define SAME_OWNER(lock1, lock2) \
206 (((lock1)->l_flock.l_pid == (lock2)->l_flock.l_pid) && \
207 ((lock1)->l_flock.l_sysid == (lock2)->l_flock.l_sysid) && \
208 ((lock1)->l_ofd == (lock2)->l_ofd))
209
210 #define COLORED(vertex) ((vertex)->l_color == (vertex)->l_graph->mark)
211 #define COLOR(vertex) ((vertex)->l_color = (vertex)->l_graph->mark)
212
213 /*
214 * stack data structure and operations
215 */
216
217 #define STACK_INIT(stack) ((stack) = NULL)
218 #define STACK_PUSH(stack, ptr, stack_link) (ptr)->stack_link = (stack),\
219 (stack) = (ptr)
220 #define STACK_POP(stack, stack_link) (stack) = (stack)->stack_link
221 #define STACK_TOP(stack) (stack)
222 #define STACK_EMPTY(stack) ((stack) == NULL)
223
224
225 #define ACTIVE_HEAD(gp) (&(gp)->active_locks)
226
227 #define SLEEPING_HEAD(gp) (&(gp)->sleeping_locks)
228
229 #define SET_LOCK_TO_FIRST_ACTIVE_VP(gp, lock, vp) \
230 { \
231 (lock) = (lock_descriptor_t *)vp->v_filocks; \
232 }
233
234 #define SET_LOCK_TO_FIRST_SLEEP_VP(gp, lock, vp) \
235 { \
236 for ((lock) = SLEEPING_HEAD((gp))->l_next; ((lock) != SLEEPING_HEAD((gp)) && \
237 (lock)->l_vnode != (vp)); (lock) = (lock)->l_next) \
238 ; \
239 (lock) = ((lock) == SLEEPING_HEAD((gp))) ? NULL : (lock); \
240 }
241
242 #define OVERLAP(lock1, lock2) \
243 (((lock1)->l_start <= (lock2)->l_start && \
244 (lock2)->l_start <= (lock1)->l_end) || \
245 ((lock2)->l_start <= (lock1)->l_start && \
246 (lock1)->l_start <= (lock2)->l_end))
247
248 #define IS_INITIAL(lock) ((lock)->l_status == FLK_INITIAL_STATE)
249 #define IS_ACTIVE(lock) ((lock)->l_status == FLK_ACTIVE_STATE)
250 #define IS_SLEEPING(lock) ((lock)->l_status == FLK_SLEEPING_STATE)
251 #define IS_GRANTED(lock) ((lock)->l_status == FLK_GRANTED_STATE)
252 #define IS_INTERRUPTED(lock) ((lock)->l_status == FLK_INTERRUPTED_STATE)
253 #define IS_CANCELLED(lock) ((lock)->l_status == FLK_CANCELLED_STATE)
254 #define IS_DEAD(lock) ((lock)->l_status == FLK_DEAD_STATE)
255
256 #define IS_QUERY_LOCK(lock) ((lock)->l_state & QUERY_LOCK)
257 #define IS_RECOMPUTE(lock) ((lock)->l_state & RECOMPUTE_LOCK)
258 #define IS_BARRIER(lock) ((lock)->l_state & BARRIER_LOCK)
259 #define IS_DELETED(lock) ((lock)->l_state & DELETED_LOCK)
260 #define IS_REFERENCED(lock) ((lock)->l_state & REFERENCED_LOCK)
261 #define IS_IO_LOCK(lock) ((lock)->l_state & IO_LOCK)
262 #define IS_WILLING_TO_SLEEP(lock) \
263 ((lock)->l_state & WILLING_TO_SLEEP_LOCK)
264 #define IS_LOCKMGR(lock) ((lock)->l_state & LOCKMGR_LOCK)
265 #define IS_NLM_UP(lock) ((lock)->l_nlm_state == FLK_NLM_UP)
266 /* Clustering: Macro for PXFS locks */
267 #define IS_PXFS(lock) ((lock)->l_state & PXFS_LOCK)
268
269 /*
270 * "local" requests don't involve the NFS lock manager in any way.
271 * "remote" requests can be on the server (requests from a remote client),
272 * in which case they should be associated with a local vnode (UFS, tmpfs,
273 * etc.). These requests are flagged with LOCKMGR_LOCK and are made using
274 * kernel service threads. Remote requests can also be on an NFS client,
275 * because the NFS lock manager uses local locking for some of its
276 * bookkeeping. These requests are made by regular user processes.
277 */
278 #define IS_LOCAL(lock) (GETSYSID((lock)->l_flock.l_sysid) == 0)
279 #define IS_REMOTE(lock) (! IS_LOCAL(lock))
280
281 /* Clustering: Return value for blocking PXFS locks */
282 /*
283 * For PXFS locks, reclock() will return this error code for requests that
284 * need to block
285 */
286 #define PXFS_LOCK_BLOCKED -1
287
288 /* Clustering: PXFS callback function */
289 /*
290 * This function is a callback from the LLM into the PXFS server module. It
291 * is initialized as a weak stub, and is functional when the pxfs server module
292 * is loaded.
293 */
294 extern void cl_flk_state_transition_notify(lock_descriptor_t *lock,
295 int old_state, int new_state);
296
297 #define BLOCKS(lock1, lock2) (!SAME_OWNER((lock1), (lock2)) && \
298 (((lock1)->l_type == F_WRLCK) || \
299 ((lock2)->l_type == F_WRLCK)) && \
300 OVERLAP((lock1), (lock2)))
301
302 #define COVERS(lock1, lock2) \
303 (((lock1)->l_start <= (lock2)->l_start) && \
304 ((lock1)->l_end >= (lock2)->l_end))
305
306 #define IN_LIST_REMOVE(ep) \
307 { \
308 (ep)->edge_in_next->edge_in_prev = (ep)->edge_in_prev; \
309 (ep)->edge_in_prev->edge_in_next = (ep)->edge_in_next; \
310 }
311
312 #define ADJ_LIST_REMOVE(ep) \
313 { \
314 (ep)->edge_adj_next->edge_adj_prev = (ep)->edge_adj_prev; \
315 (ep)->edge_adj_prev->edge_adj_next = (ep)->edge_adj_next; \
316 }
317
318 #define NOT_BLOCKED(lock) \
319 ((lock)->l_edge.edge_adj_next == &(lock)->l_edge && !IS_GRANTED(lock))
320
321 #define GRANT_WAKEUP(lock) \
322 { \
323 flk_set_state(lock, FLK_GRANTED_STATE); \
324 (lock)->l_state |= GRANTED_LOCK; \
325 /* \
326 * Clustering: PXFS locks do not sleep in the LLM, \
327 * so there is no need to signal them \
328 */ \
329 if (!IS_PXFS(lock)) { \
330 cv_signal(&(lock)->l_cv); \
331 } \
332 }
333
334 #define CANCEL_WAKEUP(lock) \
335 { \
336 flk_set_state(lock, FLK_CANCELLED_STATE); \
337 (lock)->l_state |= CANCELLED_LOCK; \
338 /* \
339 * Clustering: PXFS locks do not sleep in the LLM, \
340 * so there is no need to signal them \
341 */ \
342 if (!IS_PXFS(lock)) { \
343 cv_signal(&(lock)->l_cv); \
344 } \
345 }
346
347 #define INTERRUPT_WAKEUP(lock) \
348 { \
349 flk_set_state(lock, FLK_INTERRUPTED_STATE); \
350 (lock)->l_state |= INTERRUPTED_LOCK; \
351 /* \
352 * Clustering: PXFS locks do not sleep in the LLM, \
353 * so there is no need to signal them \
354 */ \
355 if (!IS_PXFS(lock)) { \
356 cv_signal(&(lock)->l_cv); \
357 } \
358 }
359
360 #define REMOVE_SLEEP_QUEUE(lock) \
361 { \
362 ASSERT(IS_SLEEPING(lock) || IS_GRANTED(lock) || \
363 IS_INTERRUPTED(lock) || IS_CANCELLED(lock)); \
364 (lock)->l_state &= ~SLEEPING_LOCK; \
365 (lock)->l_next->l_prev = (lock)->l_prev; \
366 (lock)->l_prev->l_next = (lock)->l_next; \
367 (lock)->l_next = (lock)->l_prev = (lock_descriptor_t *)NULL; \
368 }
369
370 #define NO_DEPENDENTS(lock) \
371 ((lock)->l_edge.edge_in_next == &(lock)->l_edge)
372
373 #define GRANT(lock) \
374 { \
375 (lock)->l_state |= GRANTED_LOCK; \
376 flk_set_state(lock, FLK_GRANTED_STATE); \
377 }
378
379 #define FIRST_IN(lock) ((lock)->l_edge.edge_in_next)
380 #define FIRST_ADJ(lock) ((lock)->l_edge.edge_adj_next)
381 #define HEAD(lock) (&(lock)->l_edge)
382 #define NEXT_ADJ(ep) ((ep)->edge_adj_next)
383 #define NEXT_IN(ep) ((ep)->edge_in_next)
384 #define IN_ADJ_INIT(lock) \
385 { \
386 (lock)->l_edge.edge_adj_next = (lock)->l_edge.edge_adj_prev = &(lock)->l_edge; \
387 (lock)->l_edge.edge_in_next = (lock)->l_edge.edge_in_prev = &(lock)->l_edge; \
388 }
389
390 #define COPY(lock1, lock2) \
391 { \
392 (lock1)->l_graph = (lock2)->l_graph; \
393 (lock1)->l_vnode = (lock2)->l_vnode; \
394 (lock1)->l_type = (lock2)->l_type; \
395 (lock1)->l_state = (lock2)->l_state; \
396 (lock1)->l_start = (lock2)->l_start; \
397 (lock1)->l_end = (lock2)->l_end; \
398 (lock1)->l_flock = (lock2)->l_flock; \
399 (lock1)->l_zoneid = (lock2)->l_zoneid; \
400 (lock1)->pvertex = (lock2)->pvertex; \
401 }
402
403 /*
404 * Clustering
405 */
406 /* Routines to set and get the NLM state in a lock request */
407 #define SET_NLM_STATE(lock, nlm_state) ((lock)->l_nlm_state = nlm_state)
408 #define GET_NLM_STATE(lock) ((lock)->l_nlm_state)
409 /*
410 * NLM registry abstraction:
411 * Abstraction overview:
412 * This registry keeps track of the NLM servers via their nlmids
413 * that have requested locks at the LLM this registry is associated
414 * with.
415 */
416 /* Routines to manipulate the NLM registry object state */
417 #define FLK_REGISTRY_IS_NLM_UNKNOWN(nlmreg, nlmid) \
418 ((nlmreg)[nlmid] == FLK_NLM_UNKNOWN)
419 #define FLK_REGISTRY_IS_NLM_UP(nlmreg, nlmid) \
420 ((nlmreg)[nlmid] == FLK_NLM_UP)
421 #define FLK_REGISTRY_ADD_NLMID(nlmreg, nlmid) \
422 ((nlmreg)[nlmid] = FLK_NLM_UP)
423 #define FLK_REGISTRY_CHANGE_NLM_STATE(nlmreg, nlmid, state) \
424 ((nlmreg)[nlmid] = state)
425
426 /* Indicates the effect of executing a request on the existing locks */
427
428 #define FLK_UNLOCK 0x1 /* request unlocks the existing lock */
429 #define FLK_DOWNGRADE 0x2 /* request downgrades the existing lock */
430 #define FLK_UPGRADE 0x3 /* request upgrades the existing lock */
431 #define FLK_STAY_SAME 0x4 /* request type is same as existing lock */
432
433
434 /* proc graph definitions */
435
436 /*
437 * Proc graph is the global process graph that maintains information
438 * about the dependencies between processes. An edge is added between two
439 * processes represented by proc_vertex's A and B, iff there exists l1
440 * owned by process A in any of the lock_graph's dependent on l2
441 * (thus having an edge to l2) owned by process B.
442 */
443 struct proc_vertex {
444 pid_t pid; /* pid of the process */
445 long sysid; /* sysid of the process */
446 struct proc_edge *edge; /* adajcent edges of this process */
447 int incount; /* Number of inedges to this process */
448 struct proc_edge *p_sedge; /* used for implementing stack alg. */
449 struct proc_vertex *p_stack; /* used for stack alg. */
450 int atime; /* used for cycle detection algorithm */
451 int dtime; /* used for cycle detection algorithm */
452 int index; /* index into the array of proc_graph vertices */
453 };
454
455 typedef struct proc_vertex proc_vertex_t;
456
457 struct proc_edge {
458 struct proc_edge *next; /* next edge in adjacency list */
459 int refcount; /* reference count of this edge */
460 struct proc_vertex *to_proc; /* process this points to */
461 };
462
463 typedef struct proc_edge proc_edge_t;
464
465
466 #define PROC_CHUNK 100
467
468 struct proc_graph {
469 struct proc_vertex **proc; /* list of proc_vertexes */
470 int gcount; /* list size */
471 int free; /* number of free slots in the list */
472 int mark; /* used for graph coloring */
473 };
474
475 typedef struct proc_graph proc_graph_t;
476
477 extern struct proc_graph pgraph;
478
479 #define PROC_SAME_OWNER(lock, pvertex) \
480 (((lock)->l_flock.l_pid == (pvertex)->pid) && \
481 ((lock)->l_flock.l_sysid == (pvertex)->sysid))
482
483 #define PROC_ARRIVE(pvertex) ((pvertex)->atime = pgraph.mark)
484 #define PROC_DEPART(pvertex) ((pvertex)->dtime = pgraph.mark)
485 #define PROC_ARRIVED(pvertex) ((pvertex)->atime == pgraph.mark)
486 #define PROC_DEPARTED(pvertex) ((pvertex)->dtime == pgraph.mark)
487
488 #ifdef __cplusplus
489 }
490 #endif
491
492 #endif /* _SYS_FLOCK_IMPL_H */