geom_io.c revision 106338 
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 106338 2002-11-02 11:08:07Z 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
63static u_int pace;
64
65#include <machine/atomic.h>
66
67static void
68g_bioq_lock(struct g_bioq *bq)
69{
70
71	mtx_lock(&bq->bio_queue_lock);
72}
73
74static void
75g_bioq_unlock(struct g_bioq *bq)
76{
77
78	mtx_unlock(&bq->bio_queue_lock);
79}
80
81#if 0
82static void
83g_bioq_destroy(struct g_bioq *bq)
84{
85
86	mtx_destroy(&bq->bio_queue_lock);
87}
88#endif
89
90static void
91g_bioq_init(struct g_bioq *bq)
92{
93
94	TAILQ_INIT(&bq->bio_queue);
95	mtx_init(&bq->bio_queue_lock, "bio queue", NULL, MTX_DEF);
96}
97
98static struct bio *
99g_bioq_first(struct g_bioq *bq)
100{
101	struct bio *bp;
102
103	g_bioq_lock(bq);
104	bp = TAILQ_FIRST(&bq->bio_queue);
105	if (bp != NULL) {
106		TAILQ_REMOVE(&bq->bio_queue, bp, bio_queue);
107		bq->bio_queue_length--;
108	}
109	g_bioq_unlock(bq);
110	return (bp);
111}
112
113static void
114g_bioq_enqueue_tail(struct bio *bp, struct g_bioq *rq)
115{
116
117	g_bioq_lock(rq);
118	TAILQ_INSERT_TAIL(&rq->bio_queue, bp, bio_queue);
119	rq->bio_queue_length++;
120	g_bioq_unlock(rq);
121}
122
123struct bio *
124g_new_bio(void)
125{
126	struct bio *bp;
127
128	bp = g_bioq_first(&g_bio_idle);
129	if (bp == NULL)
130		bp = g_malloc(sizeof *bp, M_NOWAIT | M_ZERO);
131	/* g_trace(G_T_BIO, "g_new_bio() = %p", bp); */
132	return (bp);
133}
134
135void
136g_destroy_bio(struct bio *bp)
137{
138
139	/* g_trace(G_T_BIO, "g_destroy_bio(%p)", bp); */
140	bzero(bp, sizeof *bp);
141	g_bioq_enqueue_tail(bp, &g_bio_idle);
142}
143
144struct bio *
145g_clone_bio(struct bio *bp)
146{
147	struct bio *bp2;
148
149	bp2 = g_new_bio();
150	if (bp2 != NULL) {
151		bp2->bio_linkage = bp;
152		bp2->bio_cmd = bp->bio_cmd;
153		bp2->bio_length = bp->bio_length;
154		bp2->bio_offset = bp->bio_offset;
155		bp2->bio_data = bp->bio_data;
156		bp2->bio_attribute = bp->bio_attribute;
157		bp->bio_children++;	/* XXX: atomic ? */
158	}
159	/* g_trace(G_T_BIO, "g_clone_bio(%p) = %p", bp, bp2); */
160	return(bp2);
161}
162
163void
164g_io_init()
165{
166
167	g_bioq_init(&g_bio_run_down);
168	g_bioq_init(&g_bio_run_up);
169	g_bioq_init(&g_bio_idle);
170}
171
172int
173g_io_setattr(const char *attr, struct g_consumer *cp, int len, void *ptr)
174{
175	struct bio *bp;
176	int error;
177
178	g_trace(G_T_BIO, "bio_setattr(%s)", attr);
179	bp = g_new_bio();
180	bp->bio_cmd = BIO_SETATTR;
181	bp->bio_done = NULL;
182	bp->bio_attribute = attr;
183	bp->bio_length = len;
184	bp->bio_data = ptr;
185	g_io_request(bp, cp);
186	error = biowait(bp, "gsetattr");
187	g_destroy_bio(bp);
188	return (error);
189}
190
191
192int
193g_io_getattr(const char *attr, struct g_consumer *cp, int *len, void *ptr)
194{
195	struct bio *bp;
196	int error;
197
198	g_trace(G_T_BIO, "bio_getattr(%s)", attr);
199	bp = g_new_bio();
200	bp->bio_cmd = BIO_GETATTR;
201	bp->bio_done = NULL;
202	bp->bio_attribute = attr;
203	bp->bio_length = *len;
204	bp->bio_data = ptr;
205	g_io_request(bp, cp);
206	error = biowait(bp, "ggetattr");
207	*len = bp->bio_completed;
208	g_destroy_bio(bp);
209	return (error);
210}
211
212void
213g_io_request(struct bio *bp, struct g_consumer *cp)
214{
215	int error;
216	off_t excess;
217
218	KASSERT(cp != NULL, ("NULL cp in g_io_request"));
219	KASSERT(bp != NULL, ("NULL bp in g_io_request"));
220	KASSERT(bp->bio_data != NULL, ("NULL bp->data in g_io_request"));
221	error = 0;
222	bp->bio_from = cp;
223	bp->bio_to = cp->provider;
224	bp->bio_error = 0;
225	bp->bio_completed = 0;
226
227	/* begin_stats(&bp->stats); */
228
229	atomic_add_int(&cp->biocount, 1);
230	/* Fail on unattached consumers */
231	if (bp->bio_to == NULL) {
232		g_io_deliver(bp, ENXIO);
233		return;
234	}
235	/* Fail if access doesn't allow operation */
236	switch(bp->bio_cmd) {
237	case BIO_READ:
238	case BIO_GETATTR:
239		if (cp->acr == 0) {
240			g_io_deliver(bp, EPERM);
241			return;
242		}
243		break;
244	case BIO_WRITE:
245	case BIO_DELETE:
246		if (cp->acw == 0) {
247			g_io_deliver(bp, EPERM);
248			return;
249		}
250		break;
251	case BIO_SETATTR:
252		/* XXX: Should ideally check for (cp->ace == 0) */
253		if ((cp->acw == 0)) {
254#ifdef DIAGNOSTIC
255			printf("setattr on %s mode (%d,%d,%d)\n",
256				cp->provider->name,
257				cp->acr, cp->acw, cp->ace);
258#endif
259			g_io_deliver(bp, EPERM);
260			return;
261		}
262		break;
263	default:
264		g_io_deliver(bp, EPERM);
265		return;
266	}
267	/* if provider is marked for error, don't disturb. */
268	if (bp->bio_to->error) {
269		g_io_deliver(bp, bp->bio_to->error);
270		return;
271	}
272	switch(bp->bio_cmd) {
273	case BIO_READ:
274	case BIO_WRITE:
275	case BIO_DELETE:
276		/* Reject requests past the end of media. */
277		if (bp->bio_offset > bp->bio_to->mediasize) {
278			g_io_deliver(bp, EIO);
279			return;
280		}
281		/* Truncate requests to the end of providers media. */
282		excess = bp->bio_offset + bp->bio_length;
283		if (excess > bp->bio_to->mediasize) {
284			excess -= bp->bio_to->mediasize;
285			bp->bio_length -= excess;
286		}
287		/* Deliver zero length transfers right here. */
288		if (bp->bio_length == 0) {
289			g_io_deliver(bp, 0);
290			return;
291		}
292		break;
293	default:
294		break;
295	}
296	/* Pass it on down. */
297	g_trace(G_T_BIO, "bio_request(%p) from %p(%s) to %p(%s) cmd %d",
298	    bp, bp->bio_from, bp->bio_from->geom->name,
299	    bp->bio_to, bp->bio_to->name, bp->bio_cmd);
300	g_bioq_enqueue_tail(bp, &g_bio_run_down);
301	wakeup(&g_wait_down);
302}
303
304void
305g_io_deliver(struct bio *bp, int error)
306{
307
308	KASSERT(bp != NULL, ("NULL bp in g_io_deliver"));
309	KASSERT(bp->bio_from != NULL, ("NULL bio_from in g_io_deliver"));
310	KASSERT(bp->bio_from->geom != NULL, ("NULL bio_from->geom in g_io_deliver"));
311	KASSERT(bp->bio_to != NULL, ("NULL bio_to in g_io_deliver"));
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, bp->bio_from, bp->bio_from->geom->name,
315	    bp->bio_to, bp->bio_to->name, bp->bio_cmd, error,
316	    (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length);
317	/* finish_stats(&bp->stats); */
318
319	if (error == ENOMEM) {
320		printf("ENOMEM %p on %p(%s)\n",
321			bp, bp->bio_to, bp->bio_to->name);
322		g_io_request(bp, bp->bio_from);
323		pace++;
324		return;
325	}
326
327	bp->bio_error = error;
328
329	g_bioq_enqueue_tail(bp, &g_bio_run_up);
330
331	wakeup(&g_wait_up);
332}
333
334void
335g_io_schedule_down(struct thread *tp __unused)
336{
337	struct bio *bp;
338
339	for(;;) {
340		bp = g_bioq_first(&g_bio_run_down);
341		if (bp == NULL)
342			break;
343		bp->bio_to->geom->start(bp);
344		if (pace) {
345			pace--;
346			break;
347		}
348	}
349}
350
351void
352g_io_schedule_up(struct thread *tp __unused)
353{
354	struct bio *bp;
355	struct g_consumer *cp;
356
357	for(;;) {
358		bp = g_bioq_first(&g_bio_run_up);
359		if (bp == NULL)
360			break;
361
362		cp = bp->bio_from;
363
364		atomic_add_int(&cp->biocount, -1);
365		biodone(bp);
366	}
367}
368
369void *
370g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error)
371{
372	struct bio *bp;
373	void *ptr;
374	int errorc;
375
376	bp = g_new_bio();
377	bp->bio_cmd = BIO_READ;
378	bp->bio_done = NULL;
379	bp->bio_offset = offset;
380	bp->bio_length = length;
381	ptr = g_malloc(length, M_WAITOK);
382	bp->bio_data = ptr;
383	g_io_request(bp, cp);
384	errorc = biowait(bp, "gread");
385	if (error != NULL)
386		*error = errorc;
387	g_destroy_bio(bp);
388	if (errorc) {
389		g_free(ptr);
390		ptr = NULL;
391	}
392	return (ptr);
393}
394
395int
396g_write_data(struct g_consumer *cp, off_t offset, void *ptr, off_t length)
397{
398	struct bio *bp;
399	int error;
400
401	bp = g_new_bio();
402	bp->bio_cmd = BIO_WRITE;
403	bp->bio_done = NULL;
404	bp->bio_offset = offset;
405	bp->bio_length = length;
406	bp->bio_data = ptr;
407	g_io_request(bp, cp);
408	error = biowait(bp, "gwrite");
409	g_destroy_bio(bp);
410	return (error);
411}
412