FreeBSD/Linux Kernel Cross Reference
sys/geom/geom_io.c
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: releng/5.1/sys/geom/geom_io.c 114795 2003-05-07 05:37:31Z phk $
36 */
37
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
45 #include <sys/errno.h>
46 #include <geom/geom.h>
47 #include <geom/geom_int.h>
48 #include <sys/devicestat.h>
49
50 #include <vm/uma.h>
51
52 static struct g_bioq g_bio_run_down;
53 static struct g_bioq g_bio_run_up;
54
55 static u_int pace;
56 static uma_zone_t biozone;
57
58 #include <machine/atomic.h>
59
60 static void
61 g_bioq_lock(struct g_bioq *bq)
62 {
63
64 mtx_lock(&bq->bio_queue_lock);
65 }
66
67 static void
68 g_bioq_unlock(struct g_bioq *bq)
69 {
70
71 mtx_unlock(&bq->bio_queue_lock);
72 }
73
74 #if 0
75 static void
76 g_bioq_destroy(struct g_bioq *bq)
77 {
78
79 mtx_destroy(&bq->bio_queue_lock);
80 }
81 #endif
82
83 static void
84 g_bioq_init(struct g_bioq *bq)
85 {
86
87 TAILQ_INIT(&bq->bio_queue);
88 mtx_init(&bq->bio_queue_lock, "bio queue", NULL, MTX_DEF);
89 }
90
91 static struct bio *
92 g_bioq_first(struct g_bioq *bq)
93 {
94 struct bio *bp;
95
96 bp = TAILQ_FIRST(&bq->bio_queue);
97 if (bp != NULL) {
98 TAILQ_REMOVE(&bq->bio_queue, bp, bio_queue);
99 bq->bio_queue_length--;
100 }
101 return (bp);
102 }
103
104 static void
105 g_bioq_enqueue_tail(struct bio *bp, struct g_bioq *rq)
106 {
107
108 g_bioq_lock(rq);
109 TAILQ_INSERT_TAIL(&rq->bio_queue, bp, bio_queue);
110 rq->bio_queue_length++;
111 g_bioq_unlock(rq);
112 }
113
114 struct bio *
115 g_new_bio(void)
116 {
117 struct bio *bp;
118
119 bp = uma_zalloc(biozone, M_NOWAIT | M_ZERO);
120 return (bp);
121 }
122
123 void
124 g_destroy_bio(struct bio *bp)
125 {
126
127 uma_zfree(biozone, bp);
128 }
129
130 struct bio *
131 g_clone_bio(struct bio *bp)
132 {
133 struct bio *bp2;
134
135 bp2 = uma_zalloc(biozone, M_NOWAIT | M_ZERO);
136 if (bp2 != NULL) {
137 bp2->bio_parent = bp;
138 bp2->bio_cmd = bp->bio_cmd;
139 bp2->bio_length = bp->bio_length;
140 bp2->bio_offset = bp->bio_offset;
141 bp2->bio_data = bp->bio_data;
142 bp2->bio_attribute = bp->bio_attribute;
143 bp->bio_children++;
144 }
145 return(bp2);
146 }
147
148 void
149 g_io_init()
150 {
151
152 g_bioq_init(&g_bio_run_down);
153 g_bioq_init(&g_bio_run_up);
154 biozone = uma_zcreate("g_bio", sizeof (struct bio),
155 NULL, NULL,
156 NULL, NULL,
157 0, 0);
158 }
159
160 int
161 g_io_getattr(const char *attr, struct g_consumer *cp, int *len, void *ptr)
162 {
163 struct bio *bp;
164 int error;
165
166 g_trace(G_T_BIO, "bio_getattr(%s)", attr);
167 bp = g_new_bio();
168 bp->bio_cmd = BIO_GETATTR;
169 bp->bio_done = NULL;
170 bp->bio_attribute = attr;
171 bp->bio_length = *len;
172 bp->bio_data = ptr;
173 g_io_request(bp, cp);
174 error = biowait(bp, "ggetattr");
175 *len = bp->bio_completed;
176 g_destroy_bio(bp);
177 return (error);
178 }
179
180 static int
181 g_io_check(struct bio *bp)
182 {
183 struct g_consumer *cp;
184 struct g_provider *pp;
185
186 cp = bp->bio_from;
187 pp = bp->bio_to;
188
189 /* Fail if access counters dont allow the operation */
190 switch(bp->bio_cmd) {
191 case BIO_READ:
192 case BIO_GETATTR:
193 if (cp->acr == 0)
194 return (EPERM);
195 break;
196 case BIO_WRITE:
197 case BIO_DELETE:
198 if (cp->acw == 0)
199 return (EPERM);
200 break;
201 default:
202 return (EPERM);
203 }
204 /* if provider is marked for error, don't disturb. */
205 if (pp->error)
206 return (pp->error);
207
208 switch(bp->bio_cmd) {
209 case BIO_READ:
210 case BIO_WRITE:
211 case BIO_DELETE:
212 /* Reject I/O not on sector boundary */
213 if (bp->bio_offset % pp->sectorsize)
214 return (EINVAL);
215 /* Reject I/O not integral sector long */
216 if (bp->bio_length % pp->sectorsize)
217 return (EINVAL);
218 /* Reject requests past the end of media. */
219 if (bp->bio_offset > pp->mediasize)
220 return (EIO);
221 break;
222 default:
223 break;
224 }
225 return (0);
226 }
227
228 void
229 g_io_request(struct bio *bp, struct g_consumer *cp)
230 {
231 struct g_provider *pp;
232
233 pp = cp->provider;
234 KASSERT(cp != NULL, ("NULL cp in g_io_request"));
235 KASSERT(bp != NULL, ("NULL bp in g_io_request"));
236 KASSERT(bp->bio_data != NULL, ("NULL bp->data in g_io_request"));
237 KASSERT(pp != NULL, ("consumer not attached in g_io_request"));
238
239 bp->bio_from = cp;
240 bp->bio_to = pp;
241 bp->bio_error = 0;
242 bp->bio_completed = 0;
243
244 if (g_collectstats) {
245 devstat_start_transaction_bio(cp->stat, bp);
246 devstat_start_transaction_bio(pp->stat, bp);
247 }
248 cp->nstart++;
249 pp->nstart++;
250
251 /* Pass it on down. */
252 g_trace(G_T_BIO, "bio_request(%p) from %p(%s) to %p(%s) cmd %d",
253 bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd);
254 g_bioq_enqueue_tail(bp, &g_bio_run_down);
255 wakeup(&g_wait_down);
256 }
257
258 void
259 g_io_deliver(struct bio *bp, int error)
260 {
261 struct g_consumer *cp;
262 struct g_provider *pp;
263
264 cp = bp->bio_from;
265 pp = bp->bio_to;
266 KASSERT(bp != NULL, ("NULL bp in g_io_deliver"));
267 KASSERT(cp != NULL, ("NULL bio_from in g_io_deliver"));
268 KASSERT(cp->geom != NULL, ("NULL bio_from->geom in g_io_deliver"));
269 KASSERT(pp != NULL, ("NULL bio_to in g_io_deliver"));
270
271 g_trace(G_T_BIO,
272 "g_io_deliver(%p) from %p(%s) to %p(%s) cmd %d error %d off %jd len %jd",
273 bp, cp, cp->geom->name, pp, pp->name, bp->bio_cmd, error,
274 (intmax_t)bp->bio_offset, (intmax_t)bp->bio_length);
275
276 bp->bio_bcount = bp->bio_length;
277 if (g_collectstats) {
278 bp->bio_resid = bp->bio_bcount - bp->bio_completed;
279 devstat_end_transaction_bio(cp->stat, bp);
280 devstat_end_transaction_bio(pp->stat, bp);
281 }
282 cp->nend++;
283 pp->nend++;
284
285 if (error == ENOMEM) {
286 if (bootverbose)
287 printf("ENOMEM %p on %p(%s)\n", bp, pp, pp->name);
288 g_io_request(bp, cp);
289 pace++;
290 return;
291 }
292 bp->bio_error = error;
293 g_bioq_enqueue_tail(bp, &g_bio_run_up);
294 wakeup(&g_wait_up);
295 }
296
297 void
298 g_io_schedule_down(struct thread *tp __unused)
299 {
300 struct bio *bp;
301 off_t excess;
302 int error;
303 struct mtx mymutex;
304
305 bzero(&mymutex, sizeof mymutex);
306 mtx_init(&mymutex, "g_xdown", MTX_DEF, 0);
307
308 for(;;) {
309 g_bioq_lock(&g_bio_run_down);
310 bp = g_bioq_first(&g_bio_run_down);
311 if (bp == NULL) {
312 msleep(&g_wait_down, &g_bio_run_down.bio_queue_lock,
313 PRIBIO | PDROP, "g_down", hz/10);
314 continue;
315 }
316 g_bioq_unlock(&g_bio_run_down);
317 if (pace > 0) {
318 msleep(&error, NULL, PRIBIO, "g_down", hz/10);
319 pace--;
320 }
321 error = g_io_check(bp);
322 if (error) {
323 g_io_deliver(bp, error);
324 continue;
325 }
326 switch (bp->bio_cmd) {
327 case BIO_READ:
328 case BIO_WRITE:
329 case BIO_DELETE:
330 /* Truncate requests to the end of providers media. */
331 excess = bp->bio_offset + bp->bio_length;
332 if (excess > bp->bio_to->mediasize) {
333 excess -= bp->bio_to->mediasize;
334 bp->bio_length -= excess;
335 }
336 /* Deliver zero length transfers right here. */
337 if (bp->bio_length == 0) {
338 g_io_deliver(bp, 0);
339 continue;
340 }
341 break;
342 default:
343 break;
344 }
345 mtx_lock(&mymutex);
346 bp->bio_to->geom->start(bp);
347 mtx_unlock(&mymutex);
348 }
349 }
350
351 void
352 g_io_schedule_up(struct thread *tp __unused)
353 {
354 struct bio *bp;
355 struct mtx mymutex;
356
357 bzero(&mymutex, sizeof mymutex);
358 mtx_init(&mymutex, "g_xup", MTX_DEF, 0);
359 for(;;) {
360 g_bioq_lock(&g_bio_run_up);
361 bp = g_bioq_first(&g_bio_run_up);
362 if (bp != NULL) {
363 g_bioq_unlock(&g_bio_run_up);
364 mtx_lock(&mymutex);
365 biodone(bp);
366 mtx_unlock(&mymutex);
367 continue;
368 }
369 msleep(&g_wait_up, &g_bio_run_up.bio_queue_lock,
370 PRIBIO | PDROP, "g_up", hz/10);
371 }
372 }
373
374 void *
375 g_read_data(struct g_consumer *cp, off_t offset, off_t length, int *error)
376 {
377 struct bio *bp;
378 void *ptr;
379 int errorc;
380
381 bp = g_new_bio();
382 bp->bio_cmd = BIO_READ;
383 bp->bio_done = NULL;
384 bp->bio_offset = offset;
385 bp->bio_length = length;
386 ptr = g_malloc(length, M_WAITOK);
387 bp->bio_data = ptr;
388 g_io_request(bp, cp);
389 errorc = biowait(bp, "gread");
390 if (error != NULL)
391 *error = errorc;
392 g_destroy_bio(bp);
393 if (errorc) {
394 g_free(ptr);
395 ptr = NULL;
396 }
397 return (ptr);
398 }
399
400 int
401 g_write_data(struct g_consumer *cp, off_t offset, void *ptr, off_t length)
402 {
403 struct bio *bp;
404 int error;
405
406 bp = g_new_bio();
407 bp->bio_cmd = BIO_WRITE;
408 bp->bio_done = NULL;
409 bp->bio_offset = offset;
410 bp->bio_length = length;
411 bp->bio_data = ptr;
412 g_io_request(bp, cp);
413 error = biowait(bp, "gwrite");
414 g_destroy_bio(bp);
415 return (error);
416 }
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