geom_io.c revision 105506 
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 105506 2002-10-20 08:45:17Z 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
59static struct g_bioq g_bio_run_down;
60static struct g_bioq g_bio_run_up;
61static struct g_bioq g_bio_idle;
62
63#include <machine/atomic.h>
64
65static void
66g_bioq_lock(struct g_bioq *bq)
67{
68
69	mtx_lock(&bq->bio_queue_lock);
70}
71
72static void
73g_bioq_unlock(struct g_bioq *bq)
74{
75
76	mtx_unlock(&bq->bio_queue_lock);
77}
78
79#if 0
80static void
81g_bioq_destroy(struct g_bioq *bq)
82{
83
84	mtx_destroy(&bq->bio_queue_lock);
85}
86#endif
87
88static void
89g_bioq_init(struct g_bioq *bq)
90{
91
92	TAILQ_INIT(&bq->bio_queue);
93	mtx_init(&bq->bio_queue_lock, "bio queue", NULL, MTX_DEF);
94}
95
96static struct bio *
97g_bioq_first(struct g_bioq *bq)
98{
99	struct bio *bp;
100
101	g_bioq_lock(bq);
102	bp = TAILQ_FIRST(&bq->bio_queue);
103	if (bp != NULL) {
104		TAILQ_REMOVE(&bq->bio_queue, bp, bio_queue);
105		bq->bio_queue_length--;
106	}
107	g_bioq_unlock(bq);
108	return (bp);
109}
110
111static void
112g_bioq_enqueue_tail(struct bio *bp, struct g_bioq *rq)
113{
114
115	g_bioq_lock(rq);
116	TAILQ_INSERT_TAIL(&rq->bio_queue, bp, bio_queue);
117	rq->bio_queue_length++;
118	g_bioq_unlock(rq);
119}
120
121struct bio *
122g_new_bio(void)
123{
124	struct bio *bp;
125
126	bp = g_bioq_first(&g_bio_idle);
127	if (bp == NULL)
128		bp = g_malloc(sizeof *bp, M_NOWAIT | M_ZERO);
129	/* g_trace(G_T_BIO, "g_new_bio() = %p", bp); */
130	return (bp);
131}
132
133void
134g_destroy_bio(struct bio *bp)
135{
136
137	/* g_trace(G_T_BIO, "g_destroy_bio(%p)", bp); */
138	bzero(bp, sizeof *bp);
139	g_bioq_enqueue_tail(bp, &g_bio_idle);
140}
141
142struct bio *
143g_clone_bio(struct bio *bp)
144{
145	struct bio *bp2;
146
147	bp2 = g_new_bio();
148	if (bp2 != NULL) {
149		bp2->bio_linkage = bp;
150		bp2->bio_cmd = bp->bio_cmd;
151		bp2->bio_length = bp->bio_length;
152		bp2->bio_offset = bp->bio_offset;
153		bp2->bio_data = bp->bio_data;
154		bp2->bio_attribute = bp->bio_attribute;
155		bp->bio_children++;	/* XXX: atomic ? */
156	}
157	/* g_trace(G_T_BIO, "g_clone_bio(%p) = %p", bp, bp2); */
158	return(bp2);
159}
160
161void
162g_io_init()
163{
164
165	g_bioq_init(&g_bio_run_down);
166	g_bioq_init(&g_bio_run_up);
167	g_bioq_init(&g_bio_idle);
168}
169
170int
171g_io_setattr(const char *attr, struct g_consumer *cp, int len, void *ptr)
172{
173	struct bio *bp;
174	int error;
175
176	g_trace(G_T_BIO, "bio_setattr(%s)", attr);
177	bp = g_new_bio();
178	bp->bio_cmd = BIO_SETATTR;
179	bp->bio_done = NULL;
180	bp->bio_attribute = attr;
181	bp->bio_length = len;
182	bp->bio_data = ptr;
183	g_io_request(bp, cp);
184	error = biowait(bp, "gsetattr");
185	g_destroy_bio(bp);
186	return (error);
187}
188
189
190int
191g_io_getattr(const char *attr, struct g_consumer *cp, int *len, void *ptr)
192{
193	struct bio *bp;
194	int error;
195
196	g_trace(G_T_BIO, "bio_getattr(%s)", attr);
197	bp = g_new_bio();
198	bp->bio_cmd = BIO_GETATTR;
199	bp->bio_done = NULL;
200	bp->bio_attribute = attr;
201	bp->bio_length = *len;
202	bp->bio_data = ptr;
203	g_io_request(bp, cp);
204	error = biowait(bp, "ggetattr");
205	*len = bp->bio_completed;
206	g_destroy_bio(bp);
207	return (error);
208}
209
210void
211g_io_request(struct bio *bp, struct g_consumer *cp)
212{
213	int error;
214	off_t excess;
215
216	KASSERT(cp != NULL, ("NULL cp in g_io_request"));
217	KASSERT(bp != NULL, ("NULL bp in g_io_request"));
218	KASSERT(bp->bio_data != NULL, ("NULL bp->data in g_io_request"));
219	error = 0;
220	bp->bio_from = cp;
221	bp->bio_to = cp->provider;
222	bp->bio_error = 0;
223	bp->bio_completed = 0;
224
225	/* begin_stats(&bp->stats); */
226
227	atomic_add_int(&cp->biocount, 1);
228	/* Fail on unattached consumers */
229	if (bp->bio_to == NULL) {
230		g_io_deliver(bp, ENXIO);
231		return;
232	}
233	/* Fail if access doesn't allow operation */
234	switch(bp->bio_cmd) {
235	case BIO_READ:
236	case BIO_GETATTR:
237		if (cp->acr == 0) {
238			g_io_deliver(bp, EPERM);
239			return;
240		}
241		break;
242	case BIO_WRITE:
243	case BIO_DELETE:
244		if (cp->acw == 0) {
245			g_io_deliver(bp, EPERM);
246			return;
247		}
248		break;
249	case BIO_SETATTR:
250		/* XXX: Should ideally check for (cp->ace == 0) */
251		if ((cp->acw == 0)) {
252#ifdef DIAGNOSTIC
253			printf("setattr on %s mode (%d,%d,%d)\n",
254				cp->provider->name,
255				cp->acr, cp->acw, cp->ace);
256#endif
257			g_io_deliver(bp, EPERM);
258			return;
259		}
260		break;
261	default:
262		g_io_deliver(bp, EPERM);
263		return;
264	}
265	/* if provider is marked for error, don't disturb. */
266	if (bp->bio_to->error) {
267		g_io_deliver(bp, bp->bio_to->error);
268		return;
269	}
270	switch(bp->bio_cmd) {
271	case BIO_READ:
272	case BIO_WRITE:
273	case BIO_DELETE:
274		/* Reject requests past the end of media. */
275		if (bp->bio_offset > bp->bio_to->mediasize) {
276			g_io_deliver(bp, EIO);
277			return;
278		}
279		/* Truncate requests to the end of providers media. */
280		excess = bp->bio_offset + bp->bio_length;
281		if (excess > bp->bio_to->mediasize) {
282			excess -= bp->bio_to->mediasize;
283			bp->bio_length -= excess;
284		}
285		/* Deliver zero length transfers right here. */
286		if (bp->bio_length == 0) {
287			g_io_deliver(bp, 0);
288			return;
289		}
290		break;
291	default:
292		break;
293	}
294	/* Pass it on down. */
295	g_trace(G_T_BIO, "bio_request(%p) from %p(%s) to %p(%s) cmd %d",
296	    bp, bp->bio_from, bp->bio_from->geom->name,
297	    bp->bio_to, bp->bio_to->name, bp->bio_cmd);
298	g_bioq_enqueue_tail(bp, &g_bio_run_down);
299	wakeup(&g_wait_down);
300}
301
302void
303g_io_deliver(struct bio *bp, int error)
304{
305
306	KASSERT(bp != NULL, ("NULL bp in g_io_deliver"));
307	KASSERT(bp->bio_from != NULL, ("NULL bio_from in g_io_deliver"));
308	KASSERT(bp->bio_from->geom != NULL, ("NULL bio_from->geom in g_io_deliver"));
309	KASSERT(bp->bio_to != NULL, ("NULL bio_to in g_io_deliver"));
310	g_trace(G_T_BIO,
311	    "g_io_deliver(%p) from %p(%s) to %p(%s) cmd %d error %d off %jd len %jd",
312	    bp, bp->bio_from, bp->bio_from->geom->name,
313	    bp->bio_to, bp->bio_to->name, bp->bio_cmd, error,
314	    (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length);
315	/* finish_stats(&bp->stats); */
316
317	bp->bio_error = error;
318
319	g_bioq_enqueue_tail(bp, &g_bio_run_up);
320
321	wakeup(&g_wait_up);
322}
323
324void
325g_io_schedule_down(struct thread *tp __unused)
326{
327	struct bio *bp;
328
329	for(;;) {
330		bp = g_bioq_first(&g_bio_run_down);
331		if (bp == NULL)
332			break;
333		bp->bio_to->geom->start(bp);
334	}
335}
336
337void
338g_io_schedule_up(struct thread *tp __unused)
339{
340	struct bio *bp;
341	struct g_consumer *cp;
342
343	for(;;) {
344		bp = g_bioq_first(&g_bio_run_up);
345		if (bp == NULL)
346			break;
347
348		cp = bp->bio_from;
349
350		atomic_add_int(&cp->biocount, -1);
351		biodone(bp);
352	}
353}
354
355void *
356g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error)
357{
358	struct bio *bp;
359	void *ptr;
360	int errorc;
361
362	bp = g_new_bio();
363	bp->bio_cmd = BIO_READ;
364	bp->bio_done = NULL;
365	bp->bio_offset = offset;
366	bp->bio_length = length;
367	ptr = g_malloc(length, M_WAITOK);
368	bp->bio_data = ptr;
369	g_io_request(bp, cp);
370	errorc = biowait(bp, "gread");
371	if (error != NULL)
372		*error = errorc;
373	g_destroy_bio(bp);
374	if (errorc) {
375		g_free(ptr);
376		ptr = NULL;
377	}
378	return (ptr);
379}
380
381int
382g_write_data(struct g_consumer *cp, off_t offset, void *ptr, off_t length)
383{
384	struct bio *bp;
385	int error;
386
387	bp = g_new_bio();
388	bp->bio_cmd = BIO_WRITE;
389	bp->bio_done = NULL;
390	bp->bio_offset = offset;
391	bp->bio_length = length;
392	bp->bio_data = ptr;
393	g_io_request(bp, cp);
394	error = biowait(bp, "gwrite");
395	g_destroy_bio(bp);
396	return (error);
397}
398