geom_io.c revision 110592 
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 * $FreeBSD: head/sys/geom/geom_io.c 110592 2003-02-09 17:04:57Z phk $
36 */
37
38
39#include <sys/param.h>
40#include <sys/stdint.h>
41#ifndef _KERNEL
42#include <stdio.h>
43#include <string.h>
44#include <stdlib.h>
45#include <signal.h>
46#include <err.h>
47#include <sched.h>
48#else
49#include <sys/systm.h>
50#include <sys/kernel.h>
51#include <sys/malloc.h>
52#include <sys/bio.h>
53#endif
54
55#include <sys/errno.h>
56#include <geom/geom.h>
57#include <geom/geom_int.h>
58#include <geom/geom_stats.h>
59
60static struct g_bioq g_bio_run_down;
61static struct g_bioq g_bio_run_up;
62static struct g_bioq g_bio_idle;
63
64static u_int pace;
65
66#include <machine/atomic.h>
67
68static void
69g_bioq_lock(struct g_bioq *bq)
70{
71
72	mtx_lock(&bq->bio_queue_lock);
73}
74
75static void
76g_bioq_unlock(struct g_bioq *bq)
77{
78
79	mtx_unlock(&bq->bio_queue_lock);
80}
81
82#if 0
83static void
84g_bioq_destroy(struct g_bioq *bq)
85{
86
87	mtx_destroy(&bq->bio_queue_lock);
88}
89#endif
90
91static void
92g_bioq_init(struct g_bioq *bq)
93{
94
95	TAILQ_INIT(&bq->bio_queue);
96	mtx_init(&bq->bio_queue_lock, "bio queue", NULL, MTX_DEF);
97}
98
99static struct bio *
100g_bioq_first(struct g_bioq *bq)
101{
102	struct bio *bp;
103
104	g_bioq_lock(bq);
105	bp = TAILQ_FIRST(&bq->bio_queue);
106	if (bp != NULL) {
107		TAILQ_REMOVE(&bq->bio_queue, bp, bio_queue);
108		bq->bio_queue_length--;
109	}
110	g_bioq_unlock(bq);
111	return (bp);
112}
113
114static void
115g_bioq_enqueue_tail(struct bio *bp, struct g_bioq *rq)
116{
117
118	g_bioq_lock(rq);
119	TAILQ_INSERT_TAIL(&rq->bio_queue, bp, bio_queue);
120	rq->bio_queue_length++;
121	g_bioq_unlock(rq);
122}
123
124struct bio *
125g_new_bio(void)
126{
127	struct bio *bp;
128
129	bp = g_bioq_first(&g_bio_idle);
130	if (bp == NULL)
131		bp = g_malloc(sizeof *bp, M_NOWAIT | M_ZERO);
132	/* g_trace(G_T_BIO, "g_new_bio() = %p", bp); */
133	return (bp);
134}
135
136void
137g_destroy_bio(struct bio *bp)
138{
139
140	/* g_trace(G_T_BIO, "g_destroy_bio(%p)", bp); */
141	bzero(bp, sizeof *bp);
142	g_bioq_enqueue_tail(bp, &g_bio_idle);
143}
144
145struct bio *
146g_clone_bio(struct bio *bp)
147{
148	struct bio *bp2;
149
150	bp2 = g_new_bio();
151	if (bp2 != NULL) {
152		bp2->bio_parent = bp;
153		bp2->bio_cmd = bp->bio_cmd;
154		bp2->bio_length = bp->bio_length;
155		bp2->bio_offset = bp->bio_offset;
156		bp2->bio_data = bp->bio_data;
157		bp2->bio_attribute = bp->bio_attribute;
158		bp->bio_children++;
159	}
160	/* g_trace(G_T_BIO, "g_clone_bio(%p) = %p", bp, bp2); */
161	return(bp2);
162}
163
164void
165g_io_init()
166{
167
168	g_bioq_init(&g_bio_run_down);
169	g_bioq_init(&g_bio_run_up);
170	g_bioq_init(&g_bio_idle);
171}
172
173int
174g_io_setattr(const char *attr, struct g_consumer *cp, int len, void *ptr)
175{
176	struct bio *bp;
177	int error;
178
179	g_trace(G_T_BIO, "bio_setattr(%s)", attr);
180	bp = g_new_bio();
181	bp->bio_cmd = BIO_SETATTR;
182	bp->bio_done = NULL;
183	bp->bio_attribute = attr;
184	bp->bio_length = len;
185	bp->bio_data = ptr;
186	g_io_request(bp, cp);
187	error = biowait(bp, "gsetattr");
188	g_destroy_bio(bp);
189	return (error);
190}
191
192
193int
194g_io_getattr(const char *attr, struct g_consumer *cp, int *len, void *ptr)
195{
196	struct bio *bp;
197	int error;
198
199	g_trace(G_T_BIO, "bio_getattr(%s)", attr);
200	bp = g_new_bio();
201	bp->bio_cmd = BIO_GETATTR;
202	bp->bio_done = NULL;
203	bp->bio_attribute = attr;
204	bp->bio_length = *len;
205	bp->bio_data = ptr;
206	g_io_request(bp, cp);
207	error = biowait(bp, "ggetattr");
208	*len = bp->bio_completed;
209	g_destroy_bio(bp);
210	return (error);
211}
212
213static int
214g_io_check(struct bio *bp)
215{
216	struct g_consumer *cp;
217	struct g_provider *pp;
218
219	cp = bp->bio_from;
220	pp = bp->bio_to;
221
222	/* Fail if access counters dont allow the operation */
223	switch(bp->bio_cmd) {
224	case BIO_READ:
225	case BIO_GETATTR:
226		if (cp->acr == 0)
227			return (EPERM);
228		break;
229	case BIO_WRITE:
230	case BIO_DELETE:
231	case BIO_SETATTR:
232		if (cp->acw == 0)
233			return (EPERM);
234		break;
235	default:
236		return (EPERM);
237	}
238	/* if provider is marked for error, don't disturb. */
239	if (pp->error)
240		return (pp->error);
241
242	switch(bp->bio_cmd) {
243	case BIO_READ:
244	case BIO_WRITE:
245	case BIO_DELETE:
246		/* Reject I/O not on sector boundary */
247		if (bp->bio_offset % pp->sectorsize)
248			return (EINVAL);
249		/* Reject I/O not integral sector long */
250		if (bp->bio_length % pp->sectorsize)
251			return (EINVAL);
252		/* Reject requests past the end of media. */
253		if (bp->bio_offset > pp->mediasize)
254			return (EIO);
255		break;
256	default:
257		break;
258	}
259	return (0);
260}
261
262void
263g_io_request(struct bio *bp, struct g_consumer *cp)
264{
265	struct g_provider *pp;
266	struct bintime bt;
267
268	pp = cp->provider;
269	KASSERT(cp != NULL, ("NULL cp in g_io_request"));
270	KASSERT(bp != NULL, ("NULL bp in g_io_request"));
271	KASSERT(bp->bio_data != NULL, ("NULL bp->data in g_io_request"));
272	KASSERT(pp != NULL, ("consumer not attached in g_io_request"));
273
274	bp->bio_from = cp;
275	bp->bio_to = pp;
276	bp->bio_error = 0;
277	bp->bio_completed = 0;
278
279	if (g_collectstats) {
280		binuptime(&bt);
281		bp->bio_t0 = bt;
282		if (cp->stat->nop == cp->stat->nend)
283			cp->stat->wentbusy = bt; /* Consumer is idle */
284		if (pp->stat->nop == pp->stat->nend)
285			pp->stat->wentbusy = bt; /* Provider is idle */
286	}
287	cp->stat->nop++;
288	pp->stat->nop++;
289
290	/* Pass it on down. */
291	g_trace(G_T_BIO, "bio_request(%p) from %p(%s) to %p(%s) cmd %d",
292	    bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd);
293	g_bioq_enqueue_tail(bp, &g_bio_run_down);
294	wakeup(&g_wait_down);
295}
296
297void
298g_io_deliver(struct bio *bp, int error)
299{
300	struct g_consumer *cp;
301	struct g_provider *pp;
302	struct bintime t1, dt;
303	int idx;
304
305	cp = bp->bio_from;
306	pp = bp->bio_to;
307	KASSERT(bp != NULL, ("NULL bp in g_io_deliver"));
308	KASSERT(cp != NULL, ("NULL bio_from in g_io_deliver"));
309	KASSERT(cp->geom != NULL, ("NULL bio_from->geom in g_io_deliver"));
310	KASSERT(pp != NULL, ("NULL bio_to in g_io_deliver"));
311
312	g_trace(G_T_BIO,
313"g_io_deliver(%p) from %p(%s) to %p(%s) cmd %d error %d off %jd len %jd",
314	    bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd, error,
315	    (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length);
316
317	if (g_collectstats) {
318		switch (bp->bio_cmd) {
319		case BIO_READ:    idx =  G_STAT_IDX_READ;    break;
320		case BIO_WRITE:   idx =  G_STAT_IDX_WRITE;   break;
321		case BIO_DELETE:  idx =  G_STAT_IDX_DELETE;  break;
322		case BIO_GETATTR: idx =  -1; break;
323		case BIO_SETATTR: idx =  -1; break;
324		default:
325			panic("unknown bio_cmd in g_io_deliver");
326			break;
327		}
328		binuptime(&t1);
329		/* Raise the "inconsistent" flag for userland */
330		atomic_set_acq_int(&cp->stat->updating, 1);
331		atomic_set_acq_int(&pp->stat->updating, 1);
332		if (idx >= 0) {
333			/* Account the service time */
334			dt = t1;
335			bintime_sub(&dt, &bp->bio_t0);
336			bintime_add(&cp->stat->ops[idx].dt, &dt);
337			bintime_add(&pp->stat->ops[idx].dt, &dt);
338			/* ... and the metrics */
339			pp->stat->ops[idx].nbyte += bp->bio_completed;
340			cp->stat->ops[idx].nbyte += bp->bio_completed;
341			pp->stat->ops[idx].nop++;
342			cp->stat->ops[idx].nop++;
343			/* ... and any errors */
344			if (error == ENOMEM) {
345				cp->stat->ops[idx].nmem++;
346				pp->stat->ops[idx].nmem++;
347			} else if (error != 0) {
348				cp->stat->ops[idx].nerr++;
349				pp->stat->ops[idx].nerr++;
350			}
351		}
352		/* Account for busy time on the consumer */
353		dt = t1;
354		bintime_sub(&dt, &cp->stat->wentbusy);
355		bintime_add(&cp->stat->bt, &dt);
356		cp->stat->wentbusy = t1;
357		/* Account for busy time on the provider */
358		dt = t1;
359		bintime_sub(&dt, &pp->stat->wentbusy);
360		bintime_add(&pp->stat->bt, &dt);
361		pp->stat->wentbusy = t1;
362		/* Mark the structures as consistent again */
363		atomic_store_rel_int(&cp->stat->updating, 0);
364		atomic_store_rel_int(&pp->stat->updating, 0);
365	}
366	cp->stat->nend++;
367	pp->stat->nend++;
368
369	if (error == ENOMEM) {
370		printf("ENOMEM %p on %p(%s)\n", bp, pp, pp->name);
371		g_io_request(bp, cp);
372		pace++;
373		return;
374	}
375	bp->bio_error = error;
376	g_bioq_enqueue_tail(bp, &g_bio_run_up);
377	wakeup(&g_wait_up);
378}
379
380void
381g_io_schedule_down(struct thread *tp __unused)
382{
383	struct bio *bp;
384	off_t excess;
385	int error;
386
387	for(;;) {
388		bp = g_bioq_first(&g_bio_run_down);
389		if (bp == NULL)
390			break;
391		error = g_io_check(bp);
392		if (error) {
393			g_io_deliver(bp, error);
394			continue;
395		}
396		/* Truncate requests to the end of providers media. */
397		excess = bp->bio_offset + bp->bio_length;
398		if (excess > bp->bio_to->mediasize) {
399			excess -= bp->bio_to->mediasize;
400			bp->bio_length -= excess;
401		}
402		/* Deliver zero length transfers right here. */
403		if (bp->bio_length == 0) {
404			g_io_deliver(bp, 0);
405			continue;
406		}
407		bp->bio_to->geom->start(bp);
408		if (pace) {
409			pace--;
410			break;
411		}
412	}
413}
414
415void
416g_io_schedule_up(struct thread *tp __unused)
417{
418	struct bio *bp;
419	struct g_consumer *cp;
420
421	for(;;) {
422		bp = g_bioq_first(&g_bio_run_up);
423		if (bp == NULL)
424			break;
425
426		cp = bp->bio_from;
427		biodone(bp);
428	}
429}
430
431void *
432g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error)
433{
434	struct bio *bp;
435	void *ptr;
436	int errorc;
437
438	bp = g_new_bio();
439	bp->bio_cmd = BIO_READ;
440	bp->bio_done = NULL;
441	bp->bio_offset = offset;
442	bp->bio_length = length;
443	ptr = g_malloc(length, 0);
444	bp->bio_data = ptr;
445	g_io_request(bp, cp);
446	errorc = biowait(bp, "gread");
447	if (error != NULL)
448		*error = errorc;
449	g_destroy_bio(bp);
450	if (errorc) {
451		g_free(ptr);
452		ptr = NULL;
453	}
454	return (ptr);
455}
456
457int
458g_write_data(struct g_consumer *cp, off_t offset, void *ptr, off_t length)
459{
460	struct bio *bp;
461	int error;
462
463	bp = g_new_bio();
464	bp->bio_cmd = BIO_WRITE;
465	bp->bio_done = NULL;
466	bp->bio_offset = offset;
467	bp->bio_length = length;
468	bp->bio_data = ptr;
469	g_io_request(bp, cp);
470	error = biowait(bp, "gwrite");
471	g_destroy_bio(bp);
472	return (error);
473}
474