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15637ed4 RG |
1 | /* |
2 | * Copyright (c) 1982, 1986, 1989 Regents of the University of California. | |
3 | * All rights reserved. | |
4 | * | |
5 | * This code is derived from software contributed to Berkeley by | |
6 | * Scooter Morris at Genentech Inc. | |
7 | * | |
8 | * Redistribution and use in source and binary forms, with or without | |
9 | * modification, are permitted provided that the following conditions | |
10 | * are met: | |
11 | * 1. Redistributions of source code must retain the above copyright | |
12 | * notice, this list of conditions and the following disclaimer. | |
13 | * 2. Redistributions in binary form must reproduce the above copyright | |
14 | * notice, this list of conditions and the following disclaimer in the | |
15 | * documentation and/or other materials provided with the distribution. | |
16 | * 3. All advertising materials mentioning features or use of this software | |
17 | * must display the following acknowledgement: | |
18 | * This product includes software developed by the University of | |
19 | * California, Berkeley and its contributors. | |
20 | * 4. Neither the name of the University nor the names of its contributors | |
21 | * may be used to endorse or promote products derived from this software | |
22 | * without specific prior written permission. | |
23 | * | |
24 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
25 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
28 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
29 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
30 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
31 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
32 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
33 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
34 | * SUCH DAMAGE. | |
35 | * | |
36 | * @(#)ufs_lockf.c 7.7 (Berkeley) 7/2/91 | |
37 | * | |
38 | * PATCHES MAGIC LEVEL PATCH THAT GOT US HERE | |
39 | * -------------------- ----- ---------------------- | |
40 | * CURRENT PATCH LEVEL: 1 00169 | |
41 | * -------------------- ----- ---------------------- | |
42 | * | |
43 | * 04 Jun 93 Paul Kranenburg Fix dangling pointer in lockf struct | |
44 | * | |
45 | */ | |
46 | ||
47 | #include "param.h" | |
48 | #include "systm.h" | |
49 | #include "kernel.h" | |
50 | #include "file.h" | |
51 | #include "proc.h" | |
52 | #include "vnode.h" | |
53 | #include "malloc.h" | |
54 | #include "fcntl.h" | |
55 | ||
56 | #include "lockf.h" | |
57 | #include "quota.h" | |
58 | #include "inode.h" | |
59 | ||
60 | /* | |
61 | * This variable controls the maximum number of processes that will | |
62 | * be checked in doing deadlock detection. | |
63 | */ | |
64 | int maxlockdepth = MAXDEPTH; | |
65 | ||
66 | #ifdef LOCKF_DEBUG | |
67 | int lockf_debug = 0; | |
68 | #endif /* LOCKF_DEBUG */ | |
69 | ||
70 | #define NOLOCKF (struct lockf *)0 | |
71 | #define SELF 0x1 | |
72 | #define OTHERS 0x2 | |
73 | ||
74 | /* | |
75 | * Set a byte-range lock. | |
76 | */ | |
77 | lf_setlock(lock) | |
78 | register struct lockf *lock; | |
79 | { | |
80 | register struct lockf *block; | |
81 | struct inode *ip = lock->lf_inode; | |
82 | struct lockf **prev, *overlap, *ltmp; | |
83 | static char lockstr[] = "lockf"; | |
84 | int ovcase, priority, needtolink, error; | |
85 | ||
86 | #ifdef LOCKF_DEBUG | |
87 | if (lockf_debug & 1) | |
88 | lf_print("lf_setlock", lock); | |
89 | #endif /* LOCKF_DEBUG */ | |
90 | ||
91 | /* | |
92 | * Set the priority | |
93 | */ | |
94 | priority = PLOCK; | |
95 | if (lock->lf_type == F_WRLCK) | |
96 | priority += 4; | |
97 | priority |= PCATCH; | |
98 | /* | |
99 | * Scan lock list for this file looking for locks that would block us. | |
100 | */ | |
101 | while (block = lf_getblock(lock)) { | |
102 | /* | |
103 | * Free the structure and return if nonblocking. | |
104 | */ | |
105 | if ((lock->lf_flags & F_WAIT) == 0) { | |
106 | FREE(lock, M_LOCKF); | |
107 | return (EAGAIN); | |
108 | } | |
109 | /* | |
110 | * We are blocked. Since flock style locks cover | |
111 | * the whole file, there is no chance for deadlock. | |
112 | * For byte-range locks we must check for deadlock. | |
113 | * | |
114 | * Deadlock detection is done by looking through the | |
115 | * wait channels to see if there are any cycles that | |
116 | * involve us. MAXDEPTH is set just to make sure we | |
117 | * do not go off into neverland. | |
118 | */ | |
119 | if ((lock->lf_flags & F_POSIX) && | |
120 | (block->lf_flags & F_POSIX)) { | |
121 | register struct proc *wproc; | |
122 | register struct lockf *waitblock; | |
123 | int i = 0; | |
124 | ||
125 | /* The block is waiting on something */ | |
126 | wproc = (struct proc *)block->lf_id; | |
127 | while (wproc->p_wchan && | |
128 | (wproc->p_wmesg == lockstr) && | |
129 | (i++ < maxlockdepth)) { | |
130 | waitblock = (struct lockf *)wproc->p_wchan; | |
131 | /* Get the owner of the blocking lock */ | |
132 | waitblock = waitblock->lf_next; | |
133 | if ((waitblock->lf_flags & F_POSIX) == 0) | |
134 | break; | |
135 | wproc = (struct proc *)waitblock->lf_id; | |
136 | if (wproc == (struct proc *)lock->lf_id) { | |
137 | free(lock, M_LOCKF); | |
138 | return (EDEADLK); | |
139 | } | |
140 | } | |
141 | } | |
142 | /* | |
143 | * For flock type locks, we must first remove | |
144 | * any shared locks that we hold before we sleep | |
145 | * waiting for an exclusive lock. | |
146 | */ | |
147 | if ((lock->lf_flags & F_FLOCK) && | |
148 | lock->lf_type == F_WRLCK) { | |
149 | lock->lf_type = F_UNLCK; | |
150 | (void) lf_clearlock(lock); | |
151 | lock->lf_type = F_WRLCK; | |
152 | } | |
153 | /* | |
154 | * Add our lock to the blocked list and sleep until we're free. | |
155 | * Remember who blocked us (for deadlock detection). | |
156 | */ | |
157 | lock->lf_next = block; | |
158 | lf_addblock(block, lock); | |
159 | #ifdef LOCKF_DEBUG | |
160 | if (lockf_debug & 1) { | |
161 | lf_print("lf_setlock: blocking on", block); | |
162 | lf_printlist("lf_setlock", block); | |
163 | } | |
164 | #endif /* LOCKF_DEBUG */ | |
165 | if (error = tsleep((caddr_t)lock, priority, lockstr, 0)) { | |
166 | ||
167 | /* Don't leave a dangling pointer in block list */ | |
168 | if (lf_getblock(lock) == block) { | |
169 | struct lockf **prev; | |
170 | ||
171 | /* Still there, find us on list */ | |
172 | prev = &block->lf_block; | |
173 | while ((block = block->lf_block) != NOLOCKF) { | |
174 | if (block == lock) { | |
175 | *prev = block->lf_block; | |
176 | break; | |
177 | } | |
178 | prev = &block->lf_block; | |
179 | } | |
180 | } | |
181 | free(lock, M_LOCKF); | |
182 | return (error); | |
183 | } | |
184 | } | |
185 | /* | |
186 | * No blocks!! Add the lock. Note that we will | |
187 | * downgrade or upgrade any overlapping locks this | |
188 | * process already owns. | |
189 | * | |
190 | * Skip over locks owned by other processes. | |
191 | * Handle any locks that overlap and are owned by ourselves. | |
192 | */ | |
193 | prev = &ip->i_lockf; | |
194 | block = ip->i_lockf; | |
195 | needtolink = 1; | |
196 | for (;;) { | |
197 | if (ovcase = lf_findoverlap(block, lock, SELF, &prev, &overlap)) | |
198 | block = overlap->lf_next; | |
199 | /* | |
200 | * Six cases: | |
201 | * 0) no overlap | |
202 | * 1) overlap == lock | |
203 | * 2) overlap contains lock | |
204 | * 3) lock contains overlap | |
205 | * 4) overlap starts before lock | |
206 | * 5) overlap ends after lock | |
207 | */ | |
208 | switch (ovcase) { | |
209 | case 0: /* no overlap */ | |
210 | if (needtolink) { | |
211 | *prev = lock; | |
212 | lock->lf_next = overlap; | |
213 | } | |
214 | break; | |
215 | ||
216 | case 1: /* overlap == lock */ | |
217 | /* | |
218 | * If downgrading lock, others may be | |
219 | * able to acquire it. | |
220 | */ | |
221 | if (lock->lf_type == F_RDLCK && | |
222 | overlap->lf_type == F_WRLCK) | |
223 | lf_wakelock(overlap); | |
224 | overlap->lf_type = lock->lf_type; | |
225 | FREE(lock, M_LOCKF); | |
226 | lock = overlap; /* for debug output below */ | |
227 | break; | |
228 | ||
229 | case 2: /* overlap contains lock */ | |
230 | /* | |
231 | * Check for common starting point and different types. | |
232 | */ | |
233 | if (overlap->lf_type == lock->lf_type) { | |
234 | free(lock, M_LOCKF); | |
235 | lock = overlap; /* for debug output below */ | |
236 | break; | |
237 | } | |
238 | if (overlap->lf_start == lock->lf_start) { | |
239 | *prev = lock; | |
240 | lock->lf_next = overlap; | |
241 | overlap->lf_start = lock->lf_end + 1; | |
242 | } else | |
243 | lf_split(overlap, lock); | |
244 | lf_wakelock(overlap); | |
245 | break; | |
246 | ||
247 | case 3: /* lock contains overlap */ | |
248 | /* | |
249 | * If downgrading lock, others may be able to | |
250 | * acquire it, otherwise take the list. | |
251 | */ | |
252 | if (lock->lf_type == F_RDLCK && | |
253 | overlap->lf_type == F_WRLCK) { | |
254 | lf_wakelock(overlap); | |
255 | } else { | |
256 | ltmp = lock->lf_block; | |
257 | lock->lf_block = overlap->lf_block; | |
258 | lf_addblock(lock, ltmp); | |
259 | } | |
260 | /* | |
261 | * Add the new lock if necessary and delete the overlap. | |
262 | */ | |
263 | if (needtolink) { | |
264 | *prev = lock; | |
265 | lock->lf_next = overlap->lf_next; | |
266 | prev = &lock->lf_next; | |
267 | needtolink = 0; | |
268 | } else | |
269 | *prev = overlap->lf_next; | |
270 | free(overlap, M_LOCKF); | |
271 | continue; | |
272 | ||
273 | case 4: /* overlap starts before lock */ | |
274 | /* | |
275 | * Add lock after overlap on the list. | |
276 | */ | |
277 | lock->lf_next = overlap->lf_next; | |
278 | overlap->lf_next = lock; | |
279 | overlap->lf_end = lock->lf_start - 1; | |
280 | prev = &lock->lf_next; | |
281 | lf_wakelock(overlap); | |
282 | needtolink = 0; | |
283 | continue; | |
284 | ||
285 | case 5: /* overlap ends after lock */ | |
286 | /* | |
287 | * Add the new lock before overlap. | |
288 | */ | |
289 | if (needtolink) { | |
290 | *prev = lock; | |
291 | lock->lf_next = overlap; | |
292 | } | |
293 | overlap->lf_start = lock->lf_end + 1; | |
294 | lf_wakelock(overlap); | |
295 | break; | |
296 | } | |
297 | break; | |
298 | } | |
299 | #ifdef LOCKF_DEBUG | |
300 | if (lockf_debug & 1) { | |
301 | lf_print("lf_setlock: got the lock", lock); | |
302 | lf_printlist("lf_setlock", lock); | |
303 | } | |
304 | #endif /* LOCKF_DEBUG */ | |
305 | return (0); | |
306 | } | |
307 | ||
308 | /* | |
309 | * Remove a byte-range lock on an inode. | |
310 | * | |
311 | * Generally, find the lock (or an overlap to that lock) | |
312 | * and remove it (or shrink it), then wakeup anyone we can. | |
313 | */ | |
314 | lf_clearlock(unlock) | |
315 | register struct lockf *unlock; | |
316 | { | |
317 | struct inode *ip = unlock->lf_inode; | |
318 | register struct lockf *lf = ip->i_lockf; | |
319 | struct lockf *overlap, **prev; | |
320 | int ovcase; | |
321 | ||
322 | if (lf == NOLOCKF) | |
323 | return (0); | |
324 | #ifdef LOCKF_DEBUG | |
325 | if (unlock->lf_type != F_UNLCK) | |
326 | panic("lf_clearlock: bad type"); | |
327 | if (lockf_debug & 1) | |
328 | lf_print("lf_clearlock", unlock); | |
329 | #endif /* LOCKF_DEBUG */ | |
330 | prev = &ip->i_lockf; | |
331 | while (ovcase = lf_findoverlap(lf, unlock, SELF, &prev, &overlap)) { | |
332 | /* | |
333 | * Wakeup the list of locks to be retried. | |
334 | */ | |
335 | lf_wakelock(overlap); | |
336 | ||
337 | switch (ovcase) { | |
338 | ||
339 | case 1: /* overlap == lock */ | |
340 | *prev = overlap->lf_next; | |
341 | FREE(overlap, M_LOCKF); | |
342 | break; | |
343 | ||
344 | case 2: /* overlap contains lock: split it */ | |
345 | if (overlap->lf_start == unlock->lf_start) { | |
346 | overlap->lf_start = unlock->lf_end + 1; | |
347 | break; | |
348 | } | |
349 | lf_split(overlap, unlock); | |
350 | overlap->lf_next = unlock->lf_next; | |
351 | break; | |
352 | ||
353 | case 3: /* lock contains overlap */ | |
354 | *prev = overlap->lf_next; | |
355 | lf = overlap->lf_next; | |
356 | free(overlap, M_LOCKF); | |
357 | continue; | |
358 | ||
359 | case 4: /* overlap starts before lock */ | |
360 | overlap->lf_end = unlock->lf_start - 1; | |
361 | prev = &overlap->lf_next; | |
362 | lf = overlap->lf_next; | |
363 | continue; | |
364 | ||
365 | case 5: /* overlap ends after lock */ | |
366 | overlap->lf_start = unlock->lf_end + 1; | |
367 | break; | |
368 | } | |
369 | break; | |
370 | } | |
371 | #ifdef LOCKF_DEBUG | |
372 | if (lockf_debug & 1) | |
373 | lf_printlist("lf_clearlock", unlock); | |
374 | #endif /* LOCKF_DEBUG */ | |
375 | return (0); | |
376 | } | |
377 | ||
378 | /* | |
379 | * Check whether there is a blocking lock, | |
380 | * and if so return its process identifier. | |
381 | */ | |
382 | lf_getlock(lock, fl) | |
383 | register struct lockf *lock; | |
384 | register struct flock *fl; | |
385 | { | |
386 | register struct lockf *block; | |
387 | off_t start, end; | |
388 | ||
389 | #ifdef LOCKF_DEBUG | |
390 | if (lockf_debug & 1) | |
391 | lf_print("lf_getlock", lock); | |
392 | #endif /* LOCKF_DEBUG */ | |
393 | ||
394 | if (block = lf_getblock(lock)) { | |
395 | fl->l_type = block->lf_type; | |
396 | fl->l_whence = SEEK_SET; | |
397 | fl->l_start = block->lf_start; | |
398 | if (block->lf_end == -1) | |
399 | fl->l_len = 0; | |
400 | else | |
401 | fl->l_len = block->lf_end - block->lf_start + 1; | |
402 | if (block->lf_flags & F_POSIX) | |
403 | fl->l_pid = ((struct proc *)(block->lf_id))->p_pid; | |
404 | else | |
405 | fl->l_pid = -1; | |
406 | } else { | |
407 | fl->l_type = F_UNLCK; | |
408 | } | |
409 | return (0); | |
410 | } | |
411 | ||
412 | /* | |
413 | * Walk the list of locks for an inode and | |
414 | * return the first blocking lock. | |
415 | */ | |
416 | struct lockf * | |
417 | lf_getblock(lock) | |
418 | register struct lockf *lock; | |
419 | { | |
420 | struct lockf **prev, *overlap, *lf = lock->lf_inode->i_lockf; | |
421 | int ovcase; | |
422 | ||
423 | prev = &lock->lf_inode->i_lockf; | |
424 | while (ovcase = lf_findoverlap(lf, lock, OTHERS, &prev, &overlap)) { | |
425 | /* | |
426 | * We've found an overlap, see if it blocks us | |
427 | */ | |
428 | if ((lock->lf_type == F_WRLCK || overlap->lf_type == F_WRLCK)) | |
429 | return (overlap); | |
430 | /* | |
431 | * Nope, point to the next one on the list and | |
432 | * see if it blocks us | |
433 | */ | |
434 | lf = overlap->lf_next; | |
435 | } | |
436 | return (NOLOCKF); | |
437 | } | |
438 | ||
439 | /* | |
440 | * Walk the list of locks for an inode to | |
441 | * find an overlapping lock (if any). | |
442 | * | |
443 | * NOTE: this returns only the FIRST overlapping lock. There | |
444 | * may be more than one. | |
445 | */ | |
446 | lf_findoverlap(lf, lock, type, prev, overlap) | |
447 | register struct lockf *lf; | |
448 | struct lockf *lock; | |
449 | int type; | |
450 | struct lockf ***prev; | |
451 | struct lockf **overlap; | |
452 | { | |
453 | off_t start, end; | |
454 | ||
455 | *overlap = lf; | |
456 | if (lf == NOLOCKF) | |
457 | return (0); | |
458 | #ifdef LOCKF_DEBUG | |
459 | if (lockf_debug & 2) | |
460 | lf_print("lf_findoverlap: looking for overlap in", lock); | |
461 | #endif /* LOCKF_DEBUG */ | |
462 | start = lock->lf_start; | |
463 | end = lock->lf_end; | |
464 | while (lf != NOLOCKF) { | |
465 | if (((type & SELF) && lf->lf_id != lock->lf_id) || | |
466 | ((type & OTHERS) && lf->lf_id == lock->lf_id)) { | |
467 | *prev = &lf->lf_next; | |
468 | *overlap = lf = lf->lf_next; | |
469 | continue; | |
470 | } | |
471 | #ifdef LOCKF_DEBUG | |
472 | if (lockf_debug & 2) | |
473 | lf_print("\tchecking", lf); | |
474 | #endif /* LOCKF_DEBUG */ | |
475 | /* | |
476 | * OK, check for overlap | |
477 | * | |
478 | * Six cases: | |
479 | * 0) no overlap | |
480 | * 1) overlap == lock | |
481 | * 2) overlap contains lock | |
482 | * 3) lock contains overlap | |
483 | * 4) overlap starts before lock | |
484 | * 5) overlap ends after lock | |
485 | */ | |
486 | if ((lf->lf_end != -1 && start > lf->lf_end) || | |
487 | (end != -1 && lf->lf_start > end)) { | |
488 | /* Case 0 */ | |
489 | #ifdef LOCKF_DEBUG | |
490 | if (lockf_debug & 2) | |
491 | printf("no overlap\n"); | |
492 | #endif /* LOCKF_DEBUG */ | |
493 | if ((type & SELF) && end != -1 && lf->lf_start > end) | |
494 | return (0); | |
495 | *prev = &lf->lf_next; | |
496 | *overlap = lf = lf->lf_next; | |
497 | continue; | |
498 | } | |
499 | if ((lf->lf_start == start) && (lf->lf_end == end)) { | |
500 | /* Case 1 */ | |
501 | #ifdef LOCKF_DEBUG | |
502 | if (lockf_debug & 2) | |
503 | printf("overlap == lock\n"); | |
504 | #endif /* LOCKF_DEBUG */ | |
505 | return (1); | |
506 | } | |
507 | if ((lf->lf_start <= start) && | |
508 | (end != -1) && | |
509 | ((lf->lf_end >= end) || (lf->lf_end == -1))) { | |
510 | /* Case 2 */ | |
511 | #ifdef LOCKF_DEBUG | |
512 | if (lockf_debug & 2) | |
513 | printf("overlap contains lock\n"); | |
514 | #endif /* LOCKF_DEBUG */ | |
515 | return (2); | |
516 | } | |
517 | if (start <= lf->lf_start && | |
518 | (end == -1 || | |
519 | (lf->lf_end != -1 && end >= lf->lf_end))) { | |
520 | /* Case 3 */ | |
521 | #ifdef LOCKF_DEBUG | |
522 | if (lockf_debug & 2) | |
523 | printf("lock contains overlap\n"); | |
524 | #endif /* LOCKF_DEBUG */ | |
525 | return (3); | |
526 | } | |
527 | if ((lf->lf_start < start) && | |
528 | ((lf->lf_end >= start) || (lf->lf_end == -1))) { | |
529 | /* Case 4 */ | |
530 | #ifdef LOCKF_DEBUG | |
531 | if (lockf_debug & 2) | |
532 | printf("overlap starts before lock\n"); | |
533 | #endif /* LOCKF_DEBUG */ | |
534 | return (4); | |
535 | } | |
536 | if ((lf->lf_start > start) && | |
537 | (end != -1) && | |
538 | ((lf->lf_end > end) || (lf->lf_end == -1))) { | |
539 | /* Case 5 */ | |
540 | #ifdef LOCKF_DEBUG | |
541 | if (lockf_debug & 2) | |
542 | printf("overlap ends after lock\n"); | |
543 | #endif /* LOCKF_DEBUG */ | |
544 | return (5); | |
545 | } | |
546 | panic("lf_findoverlap: default"); | |
547 | } | |
548 | return (0); | |
549 | } | |
550 | ||
551 | /* | |
552 | * Add a lock to the end of the blocked list. | |
553 | */ | |
554 | lf_addblock(lock, blocked) | |
555 | struct lockf *lock; | |
556 | struct lockf *blocked; | |
557 | { | |
558 | register struct lockf *lf; | |
559 | ||
560 | if (blocked == NOLOCKF) | |
561 | return; | |
562 | #ifdef LOCKF_DEBUG | |
563 | if (lockf_debug & 2) { | |
564 | lf_print("addblock: adding", blocked); | |
565 | lf_print("to blocked list of", lock); | |
566 | } | |
567 | #endif /* LOCKF_DEBUG */ | |
568 | if ((lf = lock->lf_block) == NOLOCKF) { | |
569 | lock->lf_block = blocked; | |
570 | return; | |
571 | } | |
572 | while (lf->lf_block != NOLOCKF) | |
573 | lf = lf->lf_block; | |
574 | lf->lf_block = blocked; | |
575 | return; | |
576 | } | |
577 | ||
578 | /* | |
579 | * Split a lock and a contained region into | |
580 | * two or three locks as necessary. | |
581 | */ | |
582 | lf_split(lock1, lock2) | |
583 | register struct lockf *lock1; | |
584 | register struct lockf *lock2; | |
585 | { | |
586 | register struct lockf *splitlock; | |
587 | ||
588 | #ifdef LOCKF_DEBUG | |
589 | if (lockf_debug & 2) { | |
590 | lf_print("lf_split", lock1); | |
591 | lf_print("splitting from", lock2); | |
592 | } | |
593 | #endif /* LOCKF_DEBUG */ | |
594 | /* | |
595 | * Check to see if spliting into only two pieces. | |
596 | */ | |
597 | if (lock1->lf_start == lock2->lf_start) { | |
598 | lock1->lf_start = lock2->lf_end + 1; | |
599 | lock2->lf_next = lock1; | |
600 | return; | |
601 | } | |
602 | if (lock1->lf_end == lock2->lf_end) { | |
603 | lock1->lf_end = lock2->lf_start - 1; | |
604 | lock2->lf_next = lock1->lf_next; | |
605 | lock1->lf_next = lock2; | |
606 | return; | |
607 | } | |
608 | /* | |
609 | * Make a new lock consisting of the last part of | |
610 | * the encompassing lock | |
611 | */ | |
612 | MALLOC(splitlock, struct lockf *, sizeof *splitlock, M_LOCKF, M_WAITOK); | |
613 | bcopy((caddr_t)lock1, (caddr_t)splitlock, sizeof *splitlock); | |
614 | splitlock->lf_start = lock2->lf_end + 1; | |
615 | splitlock->lf_block = NOLOCKF; | |
616 | lock1->lf_end = lock2->lf_start - 1; | |
617 | /* | |
618 | * OK, now link it in | |
619 | */ | |
620 | splitlock->lf_next = lock1->lf_next; | |
621 | lock2->lf_next = splitlock; | |
622 | lock1->lf_next = lock2; | |
623 | } | |
624 | ||
625 | /* | |
626 | * Wakeup a blocklist | |
627 | */ | |
628 | lf_wakelock(listhead) | |
629 | struct lockf *listhead; | |
630 | { | |
631 | register struct lockf *blocklist, *wakelock; | |
632 | ||
633 | blocklist = listhead->lf_block; | |
634 | listhead->lf_block = NOLOCKF; | |
635 | while (blocklist != NOLOCKF) { | |
636 | wakelock = blocklist; | |
637 | blocklist = blocklist->lf_block; | |
638 | wakelock->lf_block = NOLOCKF; | |
639 | wakelock->lf_next = NOLOCKF; | |
640 | #ifdef LOCKF_DEBUG | |
641 | if (lockf_debug & 2) | |
642 | lf_print("lf_wakelock: awakening", wakelock); | |
643 | #endif /* LOCKF_DEBUG */ | |
644 | wakeup((caddr_t)wakelock); | |
645 | } | |
646 | } | |
647 | ||
648 | #ifdef LOCKF_DEBUG | |
649 | /* | |
650 | * Print out a lock. | |
651 | */ | |
652 | lf_print(tag, lock) | |
653 | char *tag; | |
654 | register struct lockf *lock; | |
655 | { | |
656 | ||
657 | printf("%s: lock 0x%lx for ", tag, lock); | |
658 | if (lock->lf_flags & F_POSIX) | |
659 | printf("proc %d", ((struct proc *)(lock->lf_id))->p_pid); | |
660 | else | |
661 | printf("id 0x%x", lock->lf_id); | |
662 | printf(" in ino %d on dev <%d, %d>, %s, start %d, end %d", | |
663 | lock->lf_inode->i_number, | |
664 | major(lock->lf_inode->i_dev), | |
665 | minor(lock->lf_inode->i_dev), | |
666 | lock->lf_type == F_RDLCK ? "shared" : | |
667 | lock->lf_type == F_WRLCK ? "exclusive" : | |
668 | lock->lf_type == F_UNLCK ? "unlock" : | |
669 | "unknown", lock->lf_start, lock->lf_end); | |
670 | if (lock->lf_block) | |
671 | printf(" block 0x%x\n", lock->lf_block); | |
672 | else | |
673 | printf("\n"); | |
674 | } | |
675 | ||
676 | lf_printlist(tag, lock) | |
677 | char *tag; | |
678 | struct lockf *lock; | |
679 | { | |
680 | register struct lockf *lf; | |
681 | ||
682 | printf("%s: Lock list for ino %d on dev <%d, %d>:\n", | |
683 | tag, lock->lf_inode->i_number, | |
684 | major(lock->lf_inode->i_dev), | |
685 | minor(lock->lf_inode->i_dev)); | |
686 | for (lf = lock->lf_inode->i_lockf; lf; lf = lf->lf_next) { | |
687 | printf("\tlock 0x%lx for ", lf); | |
688 | if (lf->lf_flags & F_POSIX) | |
689 | printf("proc %d", ((struct proc *)(lf->lf_id))->p_pid); | |
690 | else | |
691 | printf("id 0x%x", lf->lf_id); | |
692 | printf(", %s, start %d, end %d", | |
693 | lf->lf_type == F_RDLCK ? "shared" : | |
694 | lf->lf_type == F_WRLCK ? "exclusive" : | |
695 | lf->lf_type == F_UNLCK ? "unlock" : | |
696 | "unknown", lf->lf_start, lf->lf_end); | |
697 | if (lf->lf_block) | |
698 | printf(" block 0x%x\n", lf->lf_block); | |
699 | else | |
700 | printf("\n"); | |
701 | } | |
702 | } | |
703 | #endif /* LOCKF_DEBUG */ |