xref: /dragonfly/sys/vfs/hammer/hammer_subs.c (revision 62f7f702) 
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 1.18 2008/05/06 00:21:08 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(struct hammer_lock *lock)
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->wanted = 1;
53 			if (hammer_debug_locks) {
54 				kprintf("hammer_lock_ex: held by %p\n",
55 					lock->locktd);
56 			}
57 			++hammer_contention_count;
58 			tsleep(lock, 0, "hmrlck", 0);
59 			if (hammer_debug_locks)
60 				kprintf("hammer_lock_ex: try again\n");
61 		}
62 		lock->locktd = td;
63 	}
64 	KKASSERT(lock->lockcount >= 0);
65 	++lock->lockcount;
66 	crit_exit();
67 }
68 
69 /*
70  * Try to obtain an exclusive lock
71  */
72 int
73 hammer_lock_ex_try(struct hammer_lock *lock)
74 {
75 	thread_t td = curthread;
76 
77 	KKASSERT(lock->refs > 0);
78 	crit_enter();
79 	if (lock->locktd != td) {
80 		if (lock->locktd != NULL || lock->lockcount) {
81 			crit_exit();
82 			return(EAGAIN);
83 		}
84 		lock->locktd = td;
85 	}
86 	KKASSERT(lock->lockcount >= 0);
87 	++lock->lockcount;
88 	crit_exit();
89 	return(0);
90 }
91 
92 void
93 hammer_lock_sh(struct hammer_lock *lock)
94 {
95 	KKASSERT(lock->refs > 0);
96 	crit_enter();
97 	while (lock->locktd != NULL) {
98 		if (lock->locktd == curthread) {
99 			Debugger("hammer_lock_sh: lock_sh on exclusive");
100 			++lock->lockcount;
101 			crit_exit();
102 			return;
103 		}
104 		lock->wanted = 1;
105 		tsleep(lock, 0, "hmrlck", 0);
106 	}
107 	KKASSERT(lock->lockcount <= 0);
108 	--lock->lockcount;
109 	crit_exit();
110 }
111 
112 /*
113  * Upgrade a shared lock to an exclusively held lock.  This function will
114  * return EDEADLK If there is more then one shared holder.
115  *
116  * No error occurs and no action is taken if the lock is already exclusively
117  * held by the caller.  If the lock is not held at all or held exclusively
118  * by someone else, this function will panic.
119  */
120 int
121 hammer_lock_upgrade(struct hammer_lock *lock)
122 {
123 	int error;
124 
125 	crit_enter();
126 	if (lock->lockcount > 0) {
127 		if (lock->locktd != curthread)
128 			panic("hammer_lock_upgrade: illegal lock state");
129 		error = 0;
130 	} else if (lock->lockcount == -1) {
131 		lock->lockcount = 1;
132 		lock->locktd = curthread;
133 		error = 0;
134 	} else if (lock->lockcount != 0) {
135 		error = EDEADLK;
136 	} else {
137 		panic("hammer_lock_upgrade: lock is not held");
138 		/* NOT REACHED */
139 		error = 0;
140 	}
141 	crit_exit();
142 	return(error);
143 }
144 
145 /*
146  * Downgrade an exclusively held lock to a shared lock.
147  */
148 void
149 hammer_lock_downgrade(struct hammer_lock *lock)
150 {
151 	KKASSERT(lock->lockcount == 1 && lock->locktd == curthread);
152 	crit_enter();
153 	lock->lockcount = -1;
154 	lock->locktd = NULL;
155 	if (lock->wanted) {
156 		lock->wanted = 0;
157 		wakeup(lock);
158 	}
159 	crit_exit();
160 	/* XXX memory barrier */
161 }
162 
163 void
164 hammer_unlock(struct hammer_lock *lock)
165 {
166 	crit_enter();
167 	KKASSERT(lock->lockcount != 0);
168 	if (lock->lockcount < 0) {
169 		if (++lock->lockcount == 0 && lock->wanted) {
170 			lock->wanted = 0;
171 			wakeup(lock);
172 		}
173 	} else {
174 		KKASSERT(lock->locktd == curthread);
175 		if (--lock->lockcount == 0) {
176 			lock->locktd = NULL;
177 			if (lock->wanted) {
178 				lock->wanted = 0;
179 				wakeup(lock);
180 			}
181 		}
182 
183 	}
184 	crit_exit();
185 }
186 
187 void
188 hammer_ref(struct hammer_lock *lock)
189 {
190 	KKASSERT(lock->refs >= 0);
191 	crit_enter();
192 	++lock->refs;
193 	crit_exit();
194 }
195 
196 void
197 hammer_unref(struct hammer_lock *lock)
198 {
199 	KKASSERT(lock->refs > 0);
200 	crit_enter();
201 	--lock->refs;
202 	crit_exit();
203 }
204 
205 u_int32_t
206 hammer_to_unix_xid(uuid_t *uuid)
207 {
208 	return(*(u_int32_t *)&uuid->node[2]);
209 }
210 
211 void
212 hammer_guid_to_uuid(uuid_t *uuid, u_int32_t guid)
213 {
214 	bzero(uuid, sizeof(*uuid));
215 	*(u_int32_t *)&uuid->node[2] = guid;
216 }
217 
218 void
219 hammer_to_timespec(hammer_tid_t tid, struct timespec *ts)
220 {
221 	ts->tv_sec = tid / 1000000000;
222 	ts->tv_nsec = tid % 1000000000;
223 }
224 
225 hammer_tid_t
226 hammer_timespec_to_transid(struct timespec *ts)
227 {
228 	hammer_tid_t tid;
229 
230 	tid = ts->tv_nsec + (unsigned long)ts->tv_sec * 1000000000LL;
231 	return(tid);
232 }
233 
234 
235 /*
236  * Convert a HAMMER filesystem object type to a vnode type
237  */
238 enum vtype
239 hammer_get_vnode_type(u_int8_t obj_type)
240 {
241 	switch(obj_type) {
242 	case HAMMER_OBJTYPE_DIRECTORY:
243 		return(VDIR);
244 	case HAMMER_OBJTYPE_REGFILE:
245 		return(VREG);
246 	case HAMMER_OBJTYPE_DBFILE:
247 		return(VDATABASE);
248 	case HAMMER_OBJTYPE_FIFO:
249 		return(VFIFO);
250 	case HAMMER_OBJTYPE_CDEV:
251 		return(VCHR);
252 	case HAMMER_OBJTYPE_BDEV:
253 		return(VBLK);
254 	case HAMMER_OBJTYPE_SOFTLINK:
255 		return(VLNK);
256 	default:
257 		return(VBAD);
258 	}
259 	/* not reached */
260 }
261 
262 int
263 hammer_get_dtype(u_int8_t obj_type)
264 {
265 	switch(obj_type) {
266 	case HAMMER_OBJTYPE_DIRECTORY:
267 		return(DT_DIR);
268 	case HAMMER_OBJTYPE_REGFILE:
269 		return(DT_REG);
270 	case HAMMER_OBJTYPE_DBFILE:
271 		return(DT_DBF);
272 	case HAMMER_OBJTYPE_FIFO:
273 		return(DT_FIFO);
274 	case HAMMER_OBJTYPE_CDEV:
275 		return(DT_CHR);
276 	case HAMMER_OBJTYPE_BDEV:
277 		return(DT_BLK);
278 	case HAMMER_OBJTYPE_SOFTLINK:
279 		return(DT_LNK);
280 	default:
281 		return(DT_UNKNOWN);
282 	}
283 	/* not reached */
284 }
285 
286 u_int8_t
287 hammer_get_obj_type(enum vtype vtype)
288 {
289 	switch(vtype) {
290 	case VDIR:
291 		return(HAMMER_OBJTYPE_DIRECTORY);
292 	case VREG:
293 		return(HAMMER_OBJTYPE_REGFILE);
294 	case VDATABASE:
295 		return(HAMMER_OBJTYPE_DBFILE);
296 	case VFIFO:
297 		return(HAMMER_OBJTYPE_FIFO);
298 	case VCHR:
299 		return(HAMMER_OBJTYPE_CDEV);
300 	case VBLK:
301 		return(HAMMER_OBJTYPE_BDEV);
302 	case VLNK:
303 		return(HAMMER_OBJTYPE_SOFTLINK);
304 	default:
305 		return(HAMMER_OBJTYPE_UNKNOWN);
306 	}
307 	/* not reached */
308 }
309 
310 /*
311  * Return a namekey hash.   The 64 bit namekey hash consists of a 32 bit
312  * crc in the MSB and 0 in the LSB.  The caller will use the low bits to
313  * generate a unique key and will scan all entries with the same upper
314  * 32 bits when issuing a lookup.
315  *
316  * We strip bit 63 in order to provide a positive key, this way a seek
317  * offset of 0 will represent the base of the directory.
318  *
319  * This function can never return 0.  We use the MSB-0 space to synthesize
320  * artificial directory entries such as "." and "..".
321  */
322 int64_t
323 hammer_directory_namekey(void *name, int len)
324 {
325 	int64_t key;
326 
327 	key = (int64_t)(crc32(name, len) & 0x7FFFFFFF) << 32;
328 	if (key == 0)
329 		key |= 0x100000000LL;
330 	return(key);
331 }
332 
333 hammer_tid_t
334 hammer_now_tid(void)
335 {
336 	struct timespec ts;
337 	hammer_tid_t tid;
338 
339 	getnanotime(&ts);
340 	tid = ts.tv_sec * 1000000000LL + ts.tv_nsec;
341 	return(tid);
342 }
343 
344 hammer_tid_t
345 hammer_str_to_tid(const char *str)
346 {
347 	hammer_tid_t tid;
348 	int len = strlen(str);
349 
350 	if (len > 10)
351 		tid = strtouq(str, NULL, 0);			/* full TID */
352 	else
353 		tid = strtouq(str, NULL, 0) * 1000000000LL;	/* time_t */
354 	return(tid);
355 }
356 
357 void
358 hammer_crc_set_blockmap(hammer_blockmap_t blockmap)
359 {
360 	blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
361 }
362 
363 void
364 hammer_crc_set_volume(hammer_volume_ondisk_t ondisk)
365 {
366 	ondisk->vol_crc = crc32(ondisk, HAMMER_VOL_CRCSIZE1) ^
367 			  crc32(&ondisk->vol_crc + 1, HAMMER_VOL_CRCSIZE2);
368 }
369 
370 int
371 hammer_crc_test_blockmap(hammer_blockmap_t blockmap)
372 {
373 	hammer_crc_t crc;
374 
375 	crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
376 	return (blockmap->entry_crc == crc);
377 }
378 
379 int
380 hammer_crc_test_volume(hammer_volume_ondisk_t ondisk)
381 {
382 	hammer_crc_t crc;
383 
384 	crc = crc32(ondisk, HAMMER_VOL_CRCSIZE1) ^
385 	      crc32(&ondisk->vol_crc + 1, HAMMER_VOL_CRCSIZE2);
386 	return (ondisk->vol_crc == crc);
387 }
388 
389 int
390 hammer_crc_test_record(hammer_record_ondisk_t ondisk)
391 {
392 	hammer_crc_t crc;
393 
394 	crc = crc32(&ondisk->base.rec_crc + 1, HAMMER_RECORD_CRCSIZE);
395 	return (ondisk->base.rec_crc == crc &&
396 		ondisk->base.signature == HAMMER_RECORD_SIGNATURE_GOOD);
397 }
398 
399 int
400 hammer_crc_test_btree(hammer_node_ondisk_t ondisk)
401 {
402 	hammer_crc_t crc;
403 
404 	crc = crc32(&ondisk->crc + 1, HAMMER_BTREE_CRCSIZE);
405 	return (ondisk->crc == crc);
406 }
407 
408 void
409 hkprintf(const char *ctl, ...)
410 {
411 	__va_list va;
412 
413 	if (hammer_debug_debug) {
414 		__va_start(va, ctl);
415 		kvprintf(ctl, va);
416 		__va_end(va);
417 	}
418 }
419 
420