geom_io.c revision 93238 
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 93238 2002-03-26 19:16:37Z phk $
36 */
37
38
39#include <sys/param.h>
40#ifndef _KERNEL
41#include <stdio.h>
42#include <string.h>
43#include <stdlib.h>
44#include <signal.h>
45#include <err.h>
46#include <sched.h>
47#else
48#include <sys/systm.h>
49#include <sys/kernel.h>
50#include <sys/malloc.h>
51#include <sys/bio.h>
52#endif
53
54#include <sys/errno.h>
55#include <geom/geom.h>
56
57static struct g_bioq g_bio_run_down;
58static struct g_bioq g_bio_run_up;
59static struct g_bioq g_bio_idle;
60
61#include <machine/atomic.h>
62
63static void
64g_bioq_lock(struct g_bioq *bq)
65{
66
67	mtx_lock(&bq->bio_queue_lock);
68}
69
70static void
71g_bioq_unlock(struct g_bioq *bq)
72{
73
74	mtx_unlock(&bq->bio_queue_lock);
75}
76
77#if 0
78static void
79g_bioq_destroy(struct g_bioq *bq)
80{
81
82	mtx_destroy(&bq->bio_queue_lock);
83}
84#endif
85
86static void
87g_bioq_init(struct g_bioq *bq)
88{
89
90	TAILQ_INIT(&bq->bio_queue);
91	mtx_init(&bq->bio_queue_lock, "bio queue", MTX_DEF);
92}
93
94static struct bio *
95g_bioq_first(struct g_bioq *bq)
96{
97	struct bio *bp;
98
99	g_bioq_lock(bq);
100	bp = TAILQ_FIRST(&bq->bio_queue);
101	if (bp != NULL) {
102		TAILQ_REMOVE(&bq->bio_queue, bp, bio_queue);
103		bq->bio_queue_length--;
104	}
105	g_bioq_unlock(bq);
106	return (bp);
107}
108
109static void
110g_bioq_enqueue_tail(struct bio *bp, struct g_bioq *rq)
111{
112
113	g_bioq_lock(rq);
114	TAILQ_INSERT_TAIL(&rq->bio_queue, bp, bio_queue);
115	rq->bio_queue_length++;
116	g_bioq_unlock(rq);
117}
118
119struct bio *
120g_new_bio(void)
121{
122	struct bio *bp;
123
124	bp = g_bioq_first(&g_bio_idle);
125	if (bp == NULL)
126		bp = g_malloc(sizeof *bp, M_WAITOK | M_ZERO);
127	g_trace(G_T_BIO, "g_new_bio() = %p", bp);
128	return (bp);
129}
130
131void
132g_destroy_bio(struct bio *bp)
133{
134
135	g_trace(G_T_BIO, "g_destroy_bio(%p)", bp);
136	bzero(bp, sizeof *bp);
137	g_bioq_enqueue_tail(bp, &g_bio_idle);
138}
139
140struct bio *
141g_clone_bio(struct bio *bp)
142{
143	struct bio *bp2;
144
145	bp2 = g_new_bio();
146	bp2->bio_linkage = bp;
147	bp2->bio_cmd = bp->bio_cmd;
148	bp2->bio_length = bp->bio_length;
149	bp2->bio_offset = bp->bio_offset;
150	bp2->bio_data = bp->bio_data;
151	bp2->bio_attribute = bp->bio_attribute;
152	g_trace(G_T_BIO, "g_clone_bio(%p) = %p", bp, bp2);
153	return(bp2);
154}
155
156void
157g_io_init()
158{
159
160	g_bioq_init(&g_bio_run_down);
161	g_bioq_init(&g_bio_run_up);
162	g_bioq_init(&g_bio_idle);
163}
164
165int
166g_io_setattr(char *attr, struct g_consumer *cp, int len, void *ptr, struct thread *tp __unused)
167{
168	struct bio *bp;
169	int error;
170
171	g_trace(G_T_BIO, "bio_setattr(%s)", attr);
172	do {
173		bp = g_new_bio();
174		bp->bio_cmd = BIO_SETATTR;
175		bp->bio_done = NULL;
176		bp->bio_attribute = attr;
177		bp->bio_length = len;
178		bp->bio_data = ptr;
179		g_io_request(bp, cp);
180		while ((bp->bio_flags & BIO_DONE) == 0) {
181			mtx_lock(&Giant);
182			tsleep(bp, 0, "setattr", hz / 10);
183			mtx_unlock(&Giant);
184		}
185		error = bp->bio_error;
186		g_destroy_bio(bp);
187		if (error == EBUSY)
188			tsleep(&error, 0, "setattr_busy", hz);
189	} while(error == EBUSY);
190	return (error);
191}
192
193
194int
195g_io_getattr(char *attr, struct g_consumer *cp, int *len, void *ptr, struct thread *tp __unused)
196{
197	struct bio *bp;
198	int error;
199
200	g_trace(G_T_BIO, "bio_getattr(%s)", attr);
201	do {
202		bp = g_new_bio();
203		bp->bio_cmd = BIO_GETATTR;
204		bp->bio_done = NULL;
205		bp->bio_attribute = attr;
206		bp->bio_length = *len;
207		bp->bio_data = ptr;
208		g_io_request(bp, cp);
209		while ((bp->bio_flags & BIO_DONE) == 0) {
210			mtx_lock(&Giant);
211			tsleep(bp, 0, "getattr", hz / 10);
212			mtx_unlock(&Giant);
213		}
214		*len = bp->bio_completed;
215		error = bp->bio_error;
216		g_destroy_bio(bp);
217		if (error == EBUSY)
218			tsleep(&error, 0, "getattr_busy", hz);
219
220	} while(error == EBUSY);
221	return (error);
222}
223
224void
225g_io_request(struct bio *bp, struct g_consumer *cp)
226{
227	int error;
228
229	KASSERT(cp != NULL, ("bio_request on thin air"));
230	error = 0;
231	bp->bio_from = cp;
232	bp->bio_to = cp->provider;
233
234	/* begin_stats(&bp->stats); */
235
236	atomic_add_int(&cp->biocount, 1);
237	if (bp->bio_to == NULL)
238		error = ENXIO;
239	if (!error) {
240		switch(bp->bio_cmd) {
241		case BIO_READ:
242		case BIO_GETATTR:
243			if (cp->acr == 0)
244				error = EPERM;
245			break;
246		case BIO_WRITE:
247			if (cp->acw == 0)
248				error = EPERM;
249			break;
250		case BIO_SETATTR:
251		case BIO_DELETE:
252			if ((cp->acw == 0) || (cp->ace == 0))
253				error = EPERM;
254			break;
255		default:
256			error = EPERM;
257			break;
258		}
259	}
260	/* if provider is marked for error, don't disturb */
261	if (!error)
262		error = bp->bio_to->error;
263	if (error) {
264		bp->bio_error = error;
265		/* finish_stats(&bp->stats); */
266
267		g_trace(G_T_BIO,
268		    "bio_request(%p) from %p(%s) to %p(%s) cmd %d error %d\n",
269		    bp, bp->bio_from, bp->bio_from->geom->name,
270		    bp->bio_to, bp->bio_to->name, bp->bio_cmd, bp->bio_error);
271		g_bioq_enqueue_tail(bp, &g_bio_run_up);
272		mtx_lock(&Giant);
273		wakeup(&g_wait_up);
274		mtx_unlock(&Giant);
275	} else {
276		g_trace(G_T_BIO, "bio_request(%p) from %p(%s) to %p(%s) cmd %d",
277		    bp, bp->bio_from, bp->bio_from->geom->name,
278		    bp->bio_to, bp->bio_to->name, bp->bio_cmd);
279		g_bioq_enqueue_tail(bp, &g_bio_run_down);
280		mtx_lock(&Giant);
281		wakeup(&g_wait_down);
282		mtx_unlock(&Giant);
283	}
284}
285
286void
287g_io_deliver(struct bio *bp)
288{
289
290	g_trace(G_T_BIO,
291	    "g_io_deliver(%p) from %p(%s) to %p(%s) cmd %d error %d",
292	    bp, bp->bio_from, bp->bio_from->geom->name,
293	    bp->bio_to, bp->bio_to->name, bp->bio_cmd, bp->bio_error);
294	/* finish_stats(&bp->stats); */
295
296	g_bioq_enqueue_tail(bp, &g_bio_run_up);
297
298	mtx_lock(&Giant);
299	wakeup(&g_wait_up);
300	mtx_unlock(&Giant);
301}
302
303void
304g_io_schedule_down(struct thread *tp __unused)
305{
306	struct bio *bp;
307
308	for(;;) {
309		bp = g_bioq_first(&g_bio_run_down);
310		if (bp == NULL)
311			break;
312		bp->bio_to->geom->start(bp);
313	}
314}
315
316void
317g_io_schedule_up(struct thread *tp __unused)
318{
319	struct bio *bp;
320	struct g_consumer *cp;
321
322	for(;;) {
323		bp = g_bioq_first(&g_bio_run_up);
324		if (bp == NULL)
325			break;
326
327		cp = bp->bio_from;
328
329		bp->bio_flags |= BIO_DONE;
330		atomic_add_int(&cp->biocount, -1);
331		if (bp->bio_done != NULL) {
332			bp->bio_done(bp);
333		} else {
334			mtx_lock(&Giant);
335			wakeup(bp);
336			mtx_unlock(&Giant);
337		}
338	}
339}
340
341void *
342g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error)
343{
344	struct bio *bp;
345	void *ptr;
346	int errorc;
347
348        do {
349		bp = g_new_bio();
350		bp->bio_cmd = BIO_READ;
351		bp->bio_done = NULL;
352		bp->bio_offset = offset;
353		bp->bio_length = length;
354		ptr = g_malloc(length, M_WAITOK);
355		bp->bio_data = ptr;
356		g_io_request(bp, cp);
357		while ((bp->bio_flags & BIO_DONE) == 0) {
358			mtx_lock(&Giant);
359			tsleep(bp, 0, "g_read_data", hz / 10);
360			mtx_unlock(&Giant);
361		}
362		errorc = bp->bio_error;
363		if (error != NULL)
364			*error = errorc;
365		g_destroy_bio(bp);
366		if (errorc) {
367			g_free(ptr);
368			ptr = NULL;
369		}
370		if (errorc == EBUSY)
371			tsleep(&errorc, 0, "g_read_data_busy", hz);
372        } while (errorc == EBUSY);
373	return (ptr);
374}
375