xref: /dragonfly/sys/vfs/hammer/hammer_subs.c (revision cc93b0eb) 
1 /*
2  * Copyright (c) 2007-2008 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
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
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  * $DragonFly: src/sys/vfs/hammer/hammer_subs.c,v 1.32 2008/07/09 10:29:20 dillon Exp $
35  */
36 /*
37  * HAMMER structural locking
38  */
39 
40 #include "hammer.h"
41 #include <sys/dirent.h>
42 
43 void
44 hammer_lock_ex_ident(struct hammer_lock *lock, const char *ident)
45 {
46 	thread_t td = curthread;
47 
48 	KKASSERT(lock->refs > 0);
49 	crit_enter();
50 	if (lock->locktd != td) {
51 		while (lock->locktd != NULL || lock->lockcount) {
52 			++lock->exwanted;
53 			lock->wanted = 1;
54 			if (hammer_debug_locks) {
55 				kprintf("hammer_lock_ex: held by %p\n",
56 					lock->locktd);
57 			}
58 			++hammer_contention_count;
59 			tsleep(lock, 0, ident, 0);
60 			if (hammer_debug_locks)
61 				kprintf("hammer_lock_ex: try again\n");
62 			--lock->exwanted;
63 		}
64 		lock->locktd = td;
65 	}
66 	KKASSERT(lock->lockcount >= 0);
67 	++lock->lockcount;
68 	crit_exit();
69 }
70 
71 /*
72  * Try to obtain an exclusive lock
73  */
74 int
75 hammer_lock_ex_try(struct hammer_lock *lock)
76 {
77 	thread_t td = curthread;
78 
79 	KKASSERT(lock->refs > 0);
80 	crit_enter();
81 	if (lock->locktd != td) {
82 		if (lock->locktd != NULL || lock->lockcount) {
83 			crit_exit();
84 			return(EAGAIN);
85 		}
86 		lock->locktd = td;
87 	}
88 	KKASSERT(lock->lockcount >= 0);
89 	++lock->lockcount;
90 	crit_exit();
91 	return(0);
92 }
93 
94 /*
95  * Obtain a shared lock
96  */
97 void
98 hammer_lock_sh(struct hammer_lock *lock)
99 {
100 	KKASSERT(lock->refs > 0);
101 	crit_enter();
102 	while (lock->locktd != NULL) {
103 		if (lock->locktd == curthread) {
104 			Debugger("hammer_lock_sh: lock_sh on exclusive");
105 			++lock->lockcount;
106 			crit_exit();
107 			return;
108 		}
109 		lock->wanted = 1;
110 		tsleep(lock, 0, "hmrlck", 0);
111 	}
112 	KKASSERT(lock->lockcount <= 0);
113 	--lock->lockcount;
114 	crit_exit();
115 }
116 
117 /*
118  * Obtain a shared lock at a lower priority then thread waiting for an
119  * exclusive lock.  To avoid a deadlock this may only be done if no other
120  * shared locks are being held by the caller.
121  */
122 void
123 hammer_lock_sh_lowpri(struct hammer_lock *lock)
124 {
125 	KKASSERT(lock->refs > 0);
126 	crit_enter();
127 	while (lock->locktd != NULL || lock->exwanted) {
128 		if (lock->locktd == curthread) {
129 			Debugger("hammer_lock_sh: lock_sh on exclusive");
130 			++lock->lockcount;
131 			crit_exit();
132 			return;
133 		}
134 		lock->wanted = 1;
135 		tsleep(lock, 0, "hmrlck", 0);
136 	}
137 	KKASSERT(lock->lockcount <= 0);
138 	--lock->lockcount;
139 	crit_exit();
140 }
141 
142 int
143 hammer_lock_sh_try(struct hammer_lock *lock)
144 {
145 	KKASSERT(lock->refs > 0);
146 	crit_enter();
147 	if (lock->locktd) {
148 		crit_exit();
149 		return(EAGAIN);
150 	}
151 	KKASSERT(lock->lockcount <= 0);
152 	--lock->lockcount;
153 	crit_exit();
154 	return(0);
155 }
156 
157 /*
158  * Upgrade a shared lock to an exclusively held lock.  This function will
159  * return EDEADLK If there is more then one shared holder.
160  *
161  * No error occurs and no action is taken if the lock is already exclusively
162  * held by the caller.  If the lock is not held at all or held exclusively
163  * by someone else, this function will panic.
164  */
165 int
166 hammer_lock_upgrade(struct hammer_lock *lock)
167 {
168 	int error;
169 
170 	crit_enter();
171 	if (lock->lockcount > 0) {
172 		if (lock->locktd != curthread)
173 			panic("hammer_lock_upgrade: illegal lock state");
174 		error = 0;
175 	} else if (lock->lockcount == -1) {
176 		lock->lockcount = 1;
177 		lock->locktd = curthread;
178 		error = 0;
179 	} else if (lock->lockcount != 0) {
180 		error = EDEADLK;
181 	} else {
182 		panic("hammer_lock_upgrade: lock is not held");
183 		/* NOT REACHED */
184 		error = 0;
185 	}
186 	crit_exit();
187 	return(error);
188 }
189 
190 /*
191  * Downgrade an exclusively held lock to a shared lock.
192  */
193 void
194 hammer_lock_downgrade(struct hammer_lock *lock)
195 {
196 	KKASSERT(lock->lockcount == 1 && lock->locktd == curthread);
197 	crit_enter();
198 	lock->lockcount = -1;
199 	lock->locktd = NULL;
200 	if (lock->wanted) {
201 		lock->wanted = 0;
202 		wakeup(lock);
203 	}
204 	crit_exit();
205 	/* XXX memory barrier */
206 }
207 
208 void
209 hammer_unlock(struct hammer_lock *lock)
210 {
211 	crit_enter();
212 	KKASSERT(lock->lockcount != 0);
213 	if (lock->lockcount < 0) {
214 		if (++lock->lockcount == 0 && lock->wanted) {
215 			lock->wanted = 0;
216 			wakeup(lock);
217 		}
218 	} else {
219 		KKASSERT(lock->locktd == curthread);
220 		if (--lock->lockcount == 0) {
221 			lock->locktd = NULL;
222 			if (lock->wanted) {
223 				lock->wanted = 0;
224 				wakeup(lock);
225 			}
226 		}
227 
228 	}
229 	crit_exit();
230 }
231 
232 /*
233  * The calling thread must be holding a shared or exclusive lock.
234  * Returns < 0 if lock is held shared, and > 0 if held exlusively.
235  */
236 int
237 hammer_lock_status(struct hammer_lock *lock)
238 {
239 	if (lock->lockcount < 0)
240 		return(-1);
241 	if (lock->lockcount > 0)
242 		return(1);
243 	panic("hammer_lock_status: lock must be held: %p", lock);
244 }
245 
246 void
247 hammer_ref(struct hammer_lock *lock)
248 {
249 	KKASSERT(lock->refs >= 0);
250 	crit_enter();
251 	++lock->refs;
252 	crit_exit();
253 }
254 
255 void
256 hammer_unref(struct hammer_lock *lock)
257 {
258 	KKASSERT(lock->refs > 0);
259 	crit_enter();
260 	--lock->refs;
261 	crit_exit();
262 }
263 
264 /*
265  * The sync_lock must be held when doing any modifying operations on
266  * meta-data.  The flusher holds the lock exclusively while the reblocker
267  * and pruner use a shared lock.
268  *
269  * Modifying operations can run in parallel until the flusher needs to
270  * sync the disk media.
271  */
272 void
273 hammer_sync_lock_ex(hammer_transaction_t trans)
274 {
275 	++trans->sync_lock_refs;
276 	hammer_lock_ex(&trans->hmp->sync_lock);
277 }
278 
279 void
280 hammer_sync_lock_sh(hammer_transaction_t trans)
281 {
282 	++trans->sync_lock_refs;
283 	hammer_lock_sh(&trans->hmp->sync_lock);
284 }
285 
286 int
287 hammer_sync_lock_sh_try(hammer_transaction_t trans)
288 {
289 	int error;
290 
291 	++trans->sync_lock_refs;
292 	if ((error = hammer_lock_sh_try(&trans->hmp->sync_lock)) != 0)
293 		--trans->sync_lock_refs;
294 	return (error);
295 }
296 
297 void
298 hammer_sync_unlock(hammer_transaction_t trans)
299 {
300 	--trans->sync_lock_refs;
301 	hammer_unlock(&trans->hmp->sync_lock);
302 }
303 
304 /*
305  * Misc
306  */
307 u_int32_t
308 hammer_to_unix_xid(uuid_t *uuid)
309 {
310 	return(*(u_int32_t *)&uuid->node[2]);
311 }
312 
313 void
314 hammer_guid_to_uuid(uuid_t *uuid, u_int32_t guid)
315 {
316 	bzero(uuid, sizeof(*uuid));
317 	*(u_int32_t *)&uuid->node[2] = guid;
318 }
319 
320 void
321 hammer_time_to_timespec(u_int64_t xtime, struct timespec *ts)
322 {
323 	ts->tv_sec = (unsigned long)(xtime / 1000000);
324 	ts->tv_nsec = (unsigned int)(xtime % 1000000) * 1000L;
325 }
326 
327 u_int64_t
328 hammer_timespec_to_time(struct timespec *ts)
329 {
330 	u_int64_t xtime;
331 
332 	xtime = (unsigned)(ts->tv_nsec / 1000) +
333 		(unsigned long)ts->tv_sec * 1000000ULL;
334 	return(xtime);
335 }
336 
337 
338 /*
339  * Convert a HAMMER filesystem object type to a vnode type
340  */
341 enum vtype
342 hammer_get_vnode_type(u_int8_t obj_type)
343 {
344 	switch(obj_type) {
345 	case HAMMER_OBJTYPE_DIRECTORY:
346 		return(VDIR);
347 	case HAMMER_OBJTYPE_REGFILE:
348 		return(VREG);
349 	case HAMMER_OBJTYPE_DBFILE:
350 		return(VDATABASE);
351 	case HAMMER_OBJTYPE_FIFO:
352 		return(VFIFO);
353 	case HAMMER_OBJTYPE_SOCKET:
354 		return(VSOCK);
355 	case HAMMER_OBJTYPE_CDEV:
356 		return(VCHR);
357 	case HAMMER_OBJTYPE_BDEV:
358 		return(VBLK);
359 	case HAMMER_OBJTYPE_SOFTLINK:
360 		return(VLNK);
361 	default:
362 		return(VBAD);
363 	}
364 	/* not reached */
365 }
366 
367 int
368 hammer_get_dtype(u_int8_t obj_type)
369 {
370 	switch(obj_type) {
371 	case HAMMER_OBJTYPE_DIRECTORY:
372 		return(DT_DIR);
373 	case HAMMER_OBJTYPE_REGFILE:
374 		return(DT_REG);
375 	case HAMMER_OBJTYPE_DBFILE:
376 		return(DT_DBF);
377 	case HAMMER_OBJTYPE_FIFO:
378 		return(DT_FIFO);
379 	case HAMMER_OBJTYPE_SOCKET:
380 		return(DT_SOCK);
381 	case HAMMER_OBJTYPE_CDEV:
382 		return(DT_CHR);
383 	case HAMMER_OBJTYPE_BDEV:
384 		return(DT_BLK);
385 	case HAMMER_OBJTYPE_SOFTLINK:
386 		return(DT_LNK);
387 	default:
388 		return(DT_UNKNOWN);
389 	}
390 	/* not reached */
391 }
392 
393 u_int8_t
394 hammer_get_obj_type(enum vtype vtype)
395 {
396 	switch(vtype) {
397 	case VDIR:
398 		return(HAMMER_OBJTYPE_DIRECTORY);
399 	case VREG:
400 		return(HAMMER_OBJTYPE_REGFILE);
401 	case VDATABASE:
402 		return(HAMMER_OBJTYPE_DBFILE);
403 	case VFIFO:
404 		return(HAMMER_OBJTYPE_FIFO);
405 	case VSOCK:
406 		return(HAMMER_OBJTYPE_SOCKET);
407 	case VCHR:
408 		return(HAMMER_OBJTYPE_CDEV);
409 	case VBLK:
410 		return(HAMMER_OBJTYPE_BDEV);
411 	case VLNK:
412 		return(HAMMER_OBJTYPE_SOFTLINK);
413 	default:
414 		return(HAMMER_OBJTYPE_UNKNOWN);
415 	}
416 	/* not reached */
417 }
418 
419 /*
420  * Return flags for hammer_delete_at_cursor()
421  */
422 int
423 hammer_nohistory(hammer_inode_t ip)
424 {
425 	if (ip->hmp->hflags & HMNT_NOHISTORY)
426 		return(HAMMER_DELETE_DESTROY);
427 	if (ip->ino_data.uflags & (SF_NOHISTORY|UF_NOHISTORY))
428 		return(HAMMER_DELETE_DESTROY);
429 	return(0);
430 }
431 
432 /*
433  * Return a namekey hash.   The 64 bit namekey hash consists of a 32 bit
434  * crc in the MSB and 0 in the LSB.  The caller will use the low bits to
435  * generate a unique key and will scan all entries with the same upper
436  * 32 bits when issuing a lookup.
437  *
438  * We strip bit 63 in order to provide a positive key, this way a seek
439  * offset of 0 will represent the base of the directory.
440  *
441  * This function can never return 0.  We use the MSB-0 space to synthesize
442  * artificial directory entries such as "." and "..".
443  */
444 int64_t
445 hammer_directory_namekey(const void *name, int len)
446 {
447 	int64_t key;
448 
449 	key = (int64_t)(crc32(name, len) & 0x7FFFFFFF) << 32;
450 	if (key == 0)
451 		key |= 0x100000000LL;
452 	return(key);
453 }
454 
455 hammer_tid_t
456 hammer_str_to_tid(const char *str, int *ispfs, u_int32_t *localizationp)
457 
458 {
459 	hammer_tid_t tid;
460 	char *ptr;
461 
462 	tid = strtouq(str, &ptr, 0);
463 	if (*ptr == ':') {
464 		*ispfs = 1;
465 		*localizationp = strtoul(ptr + 1, NULL, 0) << 16;
466 	} else {
467 		*ispfs = 0;
468 	}
469 	return(tid);
470 }
471 
472 void
473 hammer_crc_set_blockmap(hammer_blockmap_t blockmap)
474 {
475 	blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
476 }
477 
478 void
479 hammer_crc_set_volume(hammer_volume_ondisk_t ondisk)
480 {
481 	ondisk->vol_crc = crc32(ondisk, HAMMER_VOL_CRCSIZE1) ^
482 			  crc32(&ondisk->vol_crc + 1, HAMMER_VOL_CRCSIZE2);
483 }
484 
485 int
486 hammer_crc_test_blockmap(hammer_blockmap_t blockmap)
487 {
488 	hammer_crc_t crc;
489 
490 	crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
491 	return (blockmap->entry_crc == crc);
492 }
493 
494 int
495 hammer_crc_test_volume(hammer_volume_ondisk_t ondisk)
496 {
497 	hammer_crc_t crc;
498 
499 	crc = crc32(ondisk, HAMMER_VOL_CRCSIZE1) ^
500 	      crc32(&ondisk->vol_crc + 1, HAMMER_VOL_CRCSIZE2);
501 	return (ondisk->vol_crc == crc);
502 }
503 
504 int
505 hammer_crc_test_btree(hammer_node_ondisk_t ondisk)
506 {
507 	hammer_crc_t crc;
508 
509 	crc = crc32(&ondisk->crc + 1, HAMMER_BTREE_CRCSIZE);
510 	return (ondisk->crc == crc);
511 }
512 
513 /*
514  * Test or set the leaf->data_crc field.  Deal with any special cases given
515  * a generic B-Tree leaf element and its data.
516  *
517  * NOTE: Inode-data: the atime and mtime fields are not CRCd, allowing them
518  *       to be updated in-place.
519  */
520 int
521 hammer_crc_test_leaf(void *data, hammer_btree_leaf_elm_t leaf)
522 {
523 	hammer_crc_t crc;
524 
525 	if (leaf->data_len == 0) {
526 		crc = 0;
527 	} else {
528 		switch(leaf->base.rec_type) {
529 		case HAMMER_RECTYPE_INODE:
530 			if (leaf->data_len != sizeof(struct hammer_inode_data))
531 				return(0);
532 			crc = crc32(data, HAMMER_INODE_CRCSIZE);
533 			break;
534 		default:
535 			crc = crc32(data, leaf->data_len);
536 			break;
537 		}
538 	}
539 	return (leaf->data_crc == crc);
540 }
541 
542 void
543 hammer_crc_set_leaf(void *data, hammer_btree_leaf_elm_t leaf)
544 {
545 	if (leaf->data_len == 0) {
546 		leaf->data_crc = 0;
547 	} else {
548 		switch(leaf->base.rec_type) {
549 		case HAMMER_RECTYPE_INODE:
550 			KKASSERT(leaf->data_len ==
551 				  sizeof(struct hammer_inode_data));
552 			leaf->data_crc = crc32(data, HAMMER_INODE_CRCSIZE);
553 			break;
554 		default:
555 			leaf->data_crc = crc32(data, leaf->data_len);
556 			break;
557 		}
558 	}
559 }
560 
561 void
562 hkprintf(const char *ctl, ...)
563 {
564 	__va_list va;
565 
566 	if (hammer_debug_debug) {
567 		__va_start(va, ctl);
568 		kvprintf(ctl, va);
569 		__va_end(va);
570 	}
571 }
572 
573 /*
574  * Return the block size at the specified file offset.
575  */
576 int
577 hammer_blocksize(int64_t file_offset)
578 {
579 	if (file_offset < HAMMER_XDEMARC)
580 		return(HAMMER_BUFSIZE);
581 	else
582 		return(HAMMER_XBUFSIZE);
583 }
584 
585 /*
586  * Return the demarkation point between the two offsets where
587  * the block size changes.
588  */
589 int64_t
590 hammer_blockdemarc(int64_t file_offset1, int64_t file_offset2)
591 {
592 	if (file_offset1 < HAMMER_XDEMARC) {
593 		if (file_offset2 <= HAMMER_XDEMARC)
594 			return(file_offset2);
595 		return(HAMMER_XDEMARC);
596 	}
597 	panic("hammer_blockdemarc: illegal range %lld %lld\n",
598 	      file_offset1, file_offset2);
599 }
600 
601 udev_t
602 hammer_fsid_to_udev(uuid_t *uuid)
603 {
604 	u_int32_t crc;
605 
606 	crc = crc32(uuid, sizeof(*uuid));
607 	return((udev_t)crc);
608 }
609 
610