xref: /freebsd/sys/geom/geom_io.c (revision 262e143bd46171a6415a5b28af260a5efa2a3db8) 
1 /*-
2  * Copyright (c) 2002 Poul-Henning Kamp
3  * Copyright (c) 2002 Networks Associates Technology, Inc.
4  * All rights reserved.
5  *
6  * This software was developed for the FreeBSD Project by Poul-Henning Kamp
7  * and NAI Labs, the Security Research Division of Network Associates, Inc.
8  * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
9  * DARPA CHATS research program.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. The names of the authors may not be used to endorse or promote
20  *    products derived from this software without specific prior written
21  *    permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/kernel.h>
42 #include <sys/malloc.h>
43 #include <sys/bio.h>
44 #include <sys/ktr.h>
45 #include <sys/proc.h>
46 #include <sys/stack.h>
47 
48 #include <sys/errno.h>
49 #include <geom/geom.h>
50 #include <geom/geom_int.h>
51 #include <sys/devicestat.h>
52 
53 #include <vm/uma.h>
54 
55 static struct g_bioq g_bio_run_down;
56 static struct g_bioq g_bio_run_up;
57 static struct g_bioq g_bio_run_task;
58 
59 static u_int pace;
60 static uma_zone_t	biozone;
61 
62 #include <machine/atomic.h>
63 
64 static void
65 g_bioq_lock(struct g_bioq *bq)
66 {
67 
68 	mtx_lock(&bq->bio_queue_lock);
69 }
70 
71 static void
72 g_bioq_unlock(struct g_bioq *bq)
73 {
74 
75 	mtx_unlock(&bq->bio_queue_lock);
76 }
77 
78 #if 0
79 static void
80 g_bioq_destroy(struct g_bioq *bq)
81 {
82 
83 	mtx_destroy(&bq->bio_queue_lock);
84 }
85 #endif
86 
87 static void
88 g_bioq_init(struct g_bioq *bq)
89 {
90 
91 	TAILQ_INIT(&bq->bio_queue);
92 	mtx_init(&bq->bio_queue_lock, "bio queue", NULL, MTX_DEF);
93 }
94 
95 static struct bio *
96 g_bioq_first(struct g_bioq *bq)
97 {
98 	struct bio *bp;
99 
100 	bp = TAILQ_FIRST(&bq->bio_queue);
101 	if (bp != NULL) {
102 		KASSERT((bp->bio_flags & BIO_ONQUEUE),
103 		    ("Bio not on queue bp=%p target %p", bp, bq));
104 		bp->bio_flags &= ~BIO_ONQUEUE;
105 		TAILQ_REMOVE(&bq->bio_queue, bp, bio_queue);
106 		bq->bio_queue_length--;
107 	}
108 	return (bp);
109 }
110 
111 struct bio *
112 g_new_bio(void)
113 {
114 	struct bio *bp;
115 
116 	bp = uma_zalloc(biozone, M_NOWAIT | M_ZERO);
117 #ifdef KTR
118 	if (KTR_COMPILE & KTR_GEOM) {
119 		struct stack st;
120 
121 		CTR1(KTR_GEOM, "g_new_bio(): %p", bp);
122 		stack_save(&st);
123 		CTRSTACK(KTR_GEOM, &st, 3, 0);
124 	}
125 #endif
126 	return (bp);
127 }
128 
129 struct bio *
130 g_alloc_bio(void)
131 {
132 	struct bio *bp;
133 
134 	bp = uma_zalloc(biozone, M_WAITOK | M_ZERO);
135 #ifdef KTR
136 	if (KTR_COMPILE & KTR_GEOM) {
137 		struct stack st;
138 
139 		CTR1(KTR_GEOM, "g_alloc_bio(): %p", bp);
140 		stack_save(&st);
141 		CTRSTACK(KTR_GEOM, &st, 3, 0);
142 	}
143 #endif
144 	return (bp);
145 }
146 
147 void
148 g_destroy_bio(struct bio *bp)
149 {
150 #ifdef KTR
151 	if (KTR_COMPILE & KTR_GEOM) {
152 		struct stack st;
153 
154 		CTR1(KTR_GEOM, "g_destroy_bio(): %p", bp);
155 		stack_save(&st);
156 		CTRSTACK(KTR_GEOM, &st, 3, 0);
157 	}
158 #endif
159 	uma_zfree(biozone, bp);
160 }
161 
162 struct bio *
163 g_clone_bio(struct bio *bp)
164 {
165 	struct bio *bp2;
166 
167 	bp2 = uma_zalloc(biozone, M_NOWAIT | M_ZERO);
168 	if (bp2 != NULL) {
169 		bp2->bio_parent = bp;
170 		bp2->bio_cmd = bp->bio_cmd;
171 		bp2->bio_length = bp->bio_length;
172 		bp2->bio_offset = bp->bio_offset;
173 		bp2->bio_data = bp->bio_data;
174 		bp2->bio_attribute = bp->bio_attribute;
175 		bp->bio_children++;
176 	}
177 #ifdef KTR
178 	if (KTR_COMPILE & KTR_GEOM) {
179 		struct stack st;
180 
181 		CTR2(KTR_GEOM, "g_close_bio(%p): %p", bp, bp2);
182 		stack_save(&st);
183 		CTRSTACK(KTR_GEOM, &st, 3, 0);
184 	}
185 #endif
186 	return(bp2);
187 }
188 
189 void
190 g_io_init()
191 {
192 
193 	g_bioq_init(&g_bio_run_down);
194 	g_bioq_init(&g_bio_run_up);
195 	g_bioq_init(&g_bio_run_task);
196 	biozone = uma_zcreate("g_bio", sizeof (struct bio),
197 	    NULL, NULL,
198 	    NULL, NULL,
199 	    0, 0);
200 }
201 
202 int
203 g_io_getattr(const char *attr, struct g_consumer *cp, int *len, void *ptr)
204 {
205 	struct bio *bp;
206 	int error;
207 
208 	g_trace(G_T_BIO, "bio_getattr(%s)", attr);
209 	bp = g_alloc_bio();
210 	bp->bio_cmd = BIO_GETATTR;
211 	bp->bio_done = NULL;
212 	bp->bio_attribute = attr;
213 	bp->bio_length = *len;
214 	bp->bio_data = ptr;
215 	g_io_request(bp, cp);
216 	error = biowait(bp, "ggetattr");
217 	*len = bp->bio_completed;
218 	g_destroy_bio(bp);
219 	return (error);
220 }
221 
222 static int
223 g_io_check(struct bio *bp)
224 {
225 	struct g_consumer *cp;
226 	struct g_provider *pp;
227 
228 	cp = bp->bio_from;
229 	pp = bp->bio_to;
230 
231 	/* Fail if access counters dont allow the operation */
232 	switch(bp->bio_cmd) {
233 	case BIO_READ:
234 	case BIO_GETATTR:
235 		if (cp->acr == 0)
236 			return (EPERM);
237 		break;
238 	case BIO_WRITE:
239 	case BIO_DELETE:
240 		if (cp->acw == 0)
241 			return (EPERM);
242 		break;
243 	default:
244 		return (EPERM);
245 	}
246 	/* if provider is marked for error, don't disturb. */
247 	if (pp->error)
248 		return (pp->error);
249 
250 	switch(bp->bio_cmd) {
251 	case BIO_READ:
252 	case BIO_WRITE:
253 	case BIO_DELETE:
254 		/* Zero sectorsize is a probably lack of media */
255 		if (pp->sectorsize == 0)
256 			return (ENXIO);
257 		/* Reject I/O not on sector boundary */
258 		if (bp->bio_offset % pp->sectorsize)
259 			return (EINVAL);
260 		/* Reject I/O not integral sector long */
261 		if (bp->bio_length % pp->sectorsize)
262 			return (EINVAL);
263 		/* Reject requests before or past the end of media. */
264 		if (bp->bio_offset < 0)
265 			return (EIO);
266 		if (bp->bio_offset > pp->mediasize)
267 			return (EIO);
268 		break;
269 	default:
270 		break;
271 	}
272 	return (0);
273 }
274 
275 void
276 g_io_request(struct bio *bp, struct g_consumer *cp)
277 {
278 	struct g_provider *pp;
279 
280 	KASSERT(cp != NULL, ("NULL cp in g_io_request"));
281 	KASSERT(bp != NULL, ("NULL bp in g_io_request"));
282 	KASSERT(bp->bio_data != NULL, ("NULL bp->data in g_io_request"));
283 	pp = cp->provider;
284 	KASSERT(pp != NULL, ("consumer not attached in g_io_request"));
285 
286 	if (bp->bio_cmd & (BIO_READ|BIO_WRITE|BIO_DELETE)) {
287 		KASSERT(bp->bio_offset % cp->provider->sectorsize == 0,
288 		    ("wrong offset %jd for sectorsize %u",
289 		    bp->bio_offset, cp->provider->sectorsize));
290 		KASSERT(bp->bio_length % cp->provider->sectorsize == 0,
291 		    ("wrong length %jd for sectorsize %u",
292 		    bp->bio_length, cp->provider->sectorsize));
293 	}
294 
295 	g_trace(G_T_BIO, "bio_request(%p) from %p(%s) to %p(%s) cmd %d",
296 	    bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd);
297 
298 	bp->bio_from = cp;
299 	bp->bio_to = pp;
300 	bp->bio_error = 0;
301 	bp->bio_completed = 0;
302 
303 	KASSERT(!(bp->bio_flags & BIO_ONQUEUE),
304 	    ("Bio already on queue bp=%p", bp));
305 	bp->bio_flags |= BIO_ONQUEUE;
306 
307 	binuptime(&bp->bio_t0);
308 
309 	/*
310 	 * The statistics collection is lockless, as such, but we
311 	 * can not update one instance of the statistics from more
312 	 * than one thread at a time, so grab the lock first.
313 	 */
314 	g_bioq_lock(&g_bio_run_down);
315 	if (g_collectstats & 1)
316 		devstat_start_transaction(pp->stat, &bp->bio_t0);
317 	if (g_collectstats & 2)
318 		devstat_start_transaction(cp->stat, &bp->bio_t0);
319 
320 	pp->nstart++;
321 	cp->nstart++;
322 	TAILQ_INSERT_TAIL(&g_bio_run_down.bio_queue, bp, bio_queue);
323 	g_bio_run_down.bio_queue_length++;
324 	g_bioq_unlock(&g_bio_run_down);
325 
326 	/* Pass it on down. */
327 	wakeup(&g_wait_down);
328 }
329 
330 void
331 g_io_deliver(struct bio *bp, int error)
332 {
333 	struct g_consumer *cp;
334 	struct g_provider *pp;
335 
336 	KASSERT(bp != NULL, ("NULL bp in g_io_deliver"));
337 	pp = bp->bio_to;
338 	KASSERT(pp != NULL, ("NULL bio_to in g_io_deliver"));
339 	cp = bp->bio_from;
340 	if (cp == NULL) {
341 		bp->bio_error = error;
342 		bp->bio_done(bp);
343 		return;
344 	}
345 	KASSERT(cp != NULL, ("NULL bio_from in g_io_deliver"));
346 	KASSERT(cp->geom != NULL, ("NULL bio_from->geom in g_io_deliver"));
347 	KASSERT(bp->bio_completed >= 0, ("bio_completed can't be less than 0"));
348 	KASSERT(bp->bio_completed <= bp->bio_length,
349 	    ("bio_completed can't be greater than bio_length"));
350 
351 	g_trace(G_T_BIO,
352 "g_io_deliver(%p) from %p(%s) to %p(%s) cmd %d error %d off %jd len %jd",
353 	    bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd, error,
354 	    (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length);
355 
356 	KASSERT(!(bp->bio_flags & BIO_ONQUEUE),
357 	    ("Bio already on queue bp=%p", bp));
358 
359 	/*
360 	 * XXX: next two doesn't belong here
361 	 */
362 	bp->bio_bcount = bp->bio_length;
363 	bp->bio_resid = bp->bio_bcount - bp->bio_completed;
364 
365 	/*
366 	 * The statistics collection is lockless, as such, but we
367 	 * can not update one instance of the statistics from more
368 	 * than one thread at a time, so grab the lock first.
369 	 */
370 	g_bioq_lock(&g_bio_run_up);
371 	if (g_collectstats & 1)
372 		devstat_end_transaction_bio(pp->stat, bp);
373 	if (g_collectstats & 2)
374 		devstat_end_transaction_bio(cp->stat, bp);
375 
376 	cp->nend++;
377 	pp->nend++;
378 	if (error != ENOMEM) {
379 		bp->bio_error = error;
380 		TAILQ_INSERT_TAIL(&g_bio_run_up.bio_queue, bp, bio_queue);
381 		bp->bio_flags |= BIO_ONQUEUE;
382 		g_bio_run_up.bio_queue_length++;
383 		g_bioq_unlock(&g_bio_run_up);
384 		wakeup(&g_wait_up);
385 		return;
386 	}
387 	g_bioq_unlock(&g_bio_run_up);
388 
389 	if (bootverbose)
390 		printf("ENOMEM %p on %p(%s)\n", bp, pp, pp->name);
391 	bp->bio_children = 0;
392 	bp->bio_inbed = 0;
393 	g_io_request(bp, cp);
394 	pace++;
395 	return;
396 }
397 
398 void
399 g_io_schedule_down(struct thread *tp __unused)
400 {
401 	struct bio *bp;
402 	off_t excess;
403 	int error;
404 
405 	for(;;) {
406 		g_bioq_lock(&g_bio_run_down);
407 		bp = g_bioq_first(&g_bio_run_down);
408 		if (bp == NULL) {
409 			CTR0(KTR_GEOM, "g_down going to sleep");
410 			msleep(&g_wait_down, &g_bio_run_down.bio_queue_lock,
411 			    PRIBIO | PDROP, "-", hz/10);
412 			continue;
413 		}
414 		CTR0(KTR_GEOM, "g_down has work to do");
415 		g_bioq_unlock(&g_bio_run_down);
416 		if (pace > 0) {
417 			CTR1(KTR_GEOM, "g_down pacing self (pace %d)", pace);
418 			msleep(&error, NULL, PRIBIO, "g_down", hz/10);
419 			pace--;
420 		}
421 		error = g_io_check(bp);
422 		if (error) {
423 			CTR3(KTR_GEOM, "g_down g_io_check on bp %p provider "
424 			    "%s returned %d", bp, bp->bio_to->name, error);
425 			g_io_deliver(bp, error);
426 			continue;
427 		}
428 		CTR2(KTR_GEOM, "g_down processing bp %p provider %s", bp,
429 		    bp->bio_to->name);
430 		switch (bp->bio_cmd) {
431 		case BIO_READ:
432 		case BIO_WRITE:
433 		case BIO_DELETE:
434 			/* Truncate requests to the end of providers media. */
435 			/*
436 			 * XXX: What if we truncate because of offset being
437 			 * bad, not length?
438 			 */
439 			excess = bp->bio_offset + bp->bio_length;
440 			if (excess > bp->bio_to->mediasize) {
441 				excess -= bp->bio_to->mediasize;
442 				bp->bio_length -= excess;
443 				if (excess > 0)
444 					CTR3(KTR_GEOM, "g_down truncated bio "
445 					    "%p provider %s by %d", bp,
446 					    bp->bio_to->name, excess);
447 			}
448 			/* Deliver zero length transfers right here. */
449 			if (bp->bio_length == 0) {
450 				g_io_deliver(bp, 0);
451 				CTR2(KTR_GEOM, "g_down terminated 0-length "
452 				    "bp %p provider %s", bp, bp->bio_to->name);
453 				continue;
454 			}
455 			break;
456 		default:
457 			break;
458 		}
459 		THREAD_NO_SLEEPING();
460 		CTR4(KTR_GEOM, "g_down starting bp %p provider %s off %ld "
461 		    "len %ld", bp, bp->bio_to->name, bp->bio_offset,
462 		    bp->bio_length);
463 		bp->bio_to->geom->start(bp);
464 		THREAD_SLEEPING_OK();
465 	}
466 }
467 
468 void
469 bio_taskqueue(struct bio *bp, bio_task_t *func, void *arg)
470 {
471 	bp->bio_task = func;
472 	bp->bio_task_arg = arg;
473 	/*
474 	 * The taskqueue is actually just a second queue off the "up"
475 	 * queue, so we use the same lock.
476 	 */
477 	g_bioq_lock(&g_bio_run_up);
478 	KASSERT(!(bp->bio_flags & BIO_ONQUEUE),
479 	    ("Bio already on queue bp=%p target taskq", bp));
480 	bp->bio_flags |= BIO_ONQUEUE;
481 	TAILQ_INSERT_TAIL(&g_bio_run_task.bio_queue, bp, bio_queue);
482 	g_bio_run_task.bio_queue_length++;
483 	wakeup(&g_wait_up);
484 	g_bioq_unlock(&g_bio_run_up);
485 }
486 
487 
488 void
489 g_io_schedule_up(struct thread *tp __unused)
490 {
491 	struct bio *bp;
492 	for(;;) {
493 		g_bioq_lock(&g_bio_run_up);
494 		bp = g_bioq_first(&g_bio_run_task);
495 		if (bp != NULL) {
496 			g_bioq_unlock(&g_bio_run_up);
497 			THREAD_NO_SLEEPING();
498 			CTR1(KTR_GEOM, "g_up processing task bp %p", bp);
499 			bp->bio_task(bp->bio_task_arg);
500 			THREAD_SLEEPING_OK();
501 			continue;
502 		}
503 		bp = g_bioq_first(&g_bio_run_up);
504 		if (bp != NULL) {
505 			g_bioq_unlock(&g_bio_run_up);
506 			THREAD_NO_SLEEPING();
507 			CTR4(KTR_GEOM, "g_up biodone bp %p provider %s off "
508 			    "%ld len %ld", bp, bp->bio_to->name,
509 			    bp->bio_offset, bp->bio_length);
510 			biodone(bp);
511 			THREAD_SLEEPING_OK();
512 			continue;
513 		}
514 		CTR0(KTR_GEOM, "g_up going to sleep");
515 		msleep(&g_wait_up, &g_bio_run_up.bio_queue_lock,
516 		    PRIBIO | PDROP, "-", hz/10);
517 	}
518 }
519 
520 void *
521 g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error)
522 {
523 	struct bio *bp;
524 	void *ptr;
525 	int errorc;
526 
527 	KASSERT(length > 0 && length >= cp->provider->sectorsize &&
528 	    length <= MAXPHYS, ("g_read_data(): invalid length %jd",
529 	    (intmax_t)length));
530 
531 	bp = g_alloc_bio();
532 	bp->bio_cmd = BIO_READ;
533 	bp->bio_done = NULL;
534 	bp->bio_offset = offset;
535 	bp->bio_length = length;
536 	ptr = g_malloc(length, M_WAITOK);
537 	bp->bio_data = ptr;
538 	g_io_request(bp, cp);
539 	errorc = biowait(bp, "gread");
540 	if (error != NULL)
541 		*error = errorc;
542 	g_destroy_bio(bp);
543 	if (errorc) {
544 		g_free(ptr);
545 		ptr = NULL;
546 	}
547 	return (ptr);
548 }
549 
550 int
551 g_write_data(struct g_consumer *cp, off_t offset, void *ptr, off_t length)
552 {
553 	struct bio *bp;
554 	int error;
555 
556 	KASSERT(length > 0 && length >= cp->provider->sectorsize &&
557 	    length <= MAXPHYS, ("g_write_data(): invalid length %jd",
558 	    (intmax_t)length));
559 
560 	bp = g_alloc_bio();
561 	bp->bio_cmd = BIO_WRITE;
562 	bp->bio_done = NULL;
563 	bp->bio_offset = offset;
564 	bp->bio_length = length;
565 	bp->bio_data = ptr;
566 	g_io_request(bp, cp);
567 	error = biowait(bp, "gwrite");
568 	g_destroy_bio(bp);
569 	return (error);
570 }
571 
572 void
573 g_print_bio(struct bio *bp)
574 {
575 	const char *pname, *cmd = NULL;
576 
577 	if (bp->bio_to != NULL)
578 		pname = bp->bio_to->name;
579 	else
580 		pname = "[unknown]";
581 
582 	switch (bp->bio_cmd) {
583 	case BIO_GETATTR:
584 		cmd = "GETATTR";
585 		printf("%s[%s(attr=%s)]", pname, cmd, bp->bio_attribute);
586 		return;
587 	case BIO_READ:
588 		cmd = "READ";
589 	case BIO_WRITE:
590 		if (cmd == NULL)
591 			cmd = "WRITE";
592 	case BIO_DELETE:
593 		if (cmd == NULL)
594 			cmd = "DELETE";
595 		printf("%s[%s(offset=%jd, length=%jd)]", pname, cmd,
596 		    (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length);
597 		return;
598 	default:
599 		cmd = "UNKNOWN";
600 		printf("%s[%s()]", pname, cmd);
601 		return;
602 	}
603 	/* NOTREACHED */
604 }
605