1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2007 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26 #pragma ident "%Z%%M% %I% %E% SMI"
27
28 #include <sys/zfs_context.h>
29 #include <sys/spa.h>
30 #include <sys/vdev_disk.h>
31 #include <sys/vdev_impl.h>
32 #include <sys/fs/zfs.h>
33 #include <sys/zio.h>
34 #include <sys/sunldi.h>
35
36 /*
37 * Virtual device vector for disks.
38 */
39
40 extern ldi_ident_t zfs_li;
41
42 typedef struct vdev_disk_buf {
43 buf_t vdb_buf;
44 zio_t *vdb_io;
45 } vdev_disk_buf_t;
46
47 static int
48 vdev_disk_open_common(vdev_t *vd)
49 {
50 vdev_disk_t *dvd;
51 dev_t dev;
52 int error;
53
54 /*
55 * We must have a pathname, and it must be absolute.
56 */
57 if (vd->vdev_path == NULL || vd->vdev_path[0] != '/') {
58 vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
59 return (EINVAL);
60 }
61
62 dvd = vd->vdev_tsd = kmem_zalloc(sizeof (vdev_disk_t), KM_SLEEP);
63
64 /*
65 * When opening a disk device, we want to preserve the user's original
66 * intent. We always want to open the device by the path the user gave
67 * us, even if it is one of multiple paths to the save device. But we
68 * also want to be able to survive disks being removed/recabled.
69 * Therefore the sequence of opening devices is:
70 *
71 * 1. Try opening the device by path. For legacy pools without the
72 * 'whole_disk' property, attempt to fix the path by appending 's0'.
73 *
74 * 2. If the devid of the device matches the stored value, return
75 * success.
76 *
77 * 3. Otherwise, the device may have moved. Try opening the device
78 * by the devid instead.
79 *
80 */
81 if (vd->vdev_devid != NULL) {
82 if (ddi_devid_str_decode(vd->vdev_devid, &dvd->vd_devid,
83 &dvd->vd_minor) != 0) {
84 vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
85 return (EINVAL);
86 }
87 }
88
89 error = EINVAL; /* presume failure */
90
91 if (vd->vdev_path != NULL) {
92 ddi_devid_t devid;
93
94 if (vd->vdev_wholedisk == -1ULL) {
95 size_t len = strlen(vd->vdev_path) + 3;
96 char *buf = kmem_alloc(len, KM_SLEEP);
97 ldi_handle_t lh;
98
99 (void) snprintf(buf, len, "%ss0", vd->vdev_path);
100
101 if (ldi_open_by_name(buf, spa_mode, kcred,
102 &lh, zfs_li) == 0) {
103 spa_strfree(vd->vdev_path);
104 vd->vdev_path = buf;
105 vd->vdev_wholedisk = 1ULL;
106 (void) ldi_close(lh, spa_mode, kcred);
107 } else {
108 kmem_free(buf, len);
109 }
110 }
111
112 error = ldi_open_by_name(vd->vdev_path, spa_mode, kcred,
113 &dvd->vd_lh, zfs_li);
114
115 /*
116 * Compare the devid to the stored value.
117 */
118 if (error == 0 && vd->vdev_devid != NULL &&
119 ldi_get_devid(dvd->vd_lh, &devid) == 0) {
120 if (ddi_devid_compare(devid, dvd->vd_devid) != 0) {
121 error = EINVAL;
122 (void) ldi_close(dvd->vd_lh, spa_mode, kcred);
123 dvd->vd_lh = NULL;
124 }
125 ddi_devid_free(devid);
126 }
127
128 /*
129 * If we succeeded in opening the device, but 'vdev_wholedisk'
130 * is not yet set, then this must be a slice.
131 */
132 if (error == 0 && vd->vdev_wholedisk == -1ULL)
133 vd->vdev_wholedisk = 0;
134 }
135
136 /*
137 * If we were unable to open by path, or the devid check fails, open by
138 * devid instead.
139 */
140 if (error != 0 && vd->vdev_devid != NULL)
141 error = ldi_open_by_devid(dvd->vd_devid, dvd->vd_minor,
142 spa_mode, kcred, &dvd->vd_lh, zfs_li);
143
144 /*
145 * If all else fails, then try opening by physical path (if available)
146 * or the logical path (if we failed due to the devid check). While not
147 * as reliable as the devid, this will give us something, and the higher
148 * level vdev validation will prevent us from opening the wrong device.
149 */
150 if (error) {
151 if (vd->vdev_physpath != NULL &&
152 (dev = ddi_pathname_to_dev_t(vd->vdev_physpath)) != ENODEV)
153 error = ldi_open_by_dev(&dev, OTYP_BLK, spa_mode,
154 kcred, &dvd->vd_lh, zfs_li);
155
156 /*
157 * Note that we don't support the legacy auto-wholedisk support
158 * as above. This hasn't been used in a very long time and we
159 * don't need to propagate its oddities to this edge condition.
160 */
161 if (error && vd->vdev_path != NULL)
162 error = ldi_open_by_name(vd->vdev_path, spa_mode, kcred,
163 &dvd->vd_lh, zfs_li);
164 }
165
166 if (error)
167 vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
168
169 return (error);
170 }
171
172 static int
173 vdev_disk_open(vdev_t *vd, uint64_t *psize, uint64_t *ashift)
174 {
175 vdev_disk_t *dvd;
176 struct dk_minfo dkm;
177 int error;
178 dev_t dev;
179 int otyp;
180
181 error = vdev_disk_open_common(vd);
182 if (error)
183 return (error);
184
185 dvd = vd->vdev_tsd;
186 /*
187 * Once a device is opened, verify that the physical device path (if
188 * available) is up to date.
189 */
190 if (ldi_get_dev(dvd->vd_lh, &dev) == 0 &&
191 ldi_get_otyp(dvd->vd_lh, &otyp) == 0) {
192 char *physpath, *minorname;
193
194 physpath = kmem_alloc(MAXPATHLEN, KM_SLEEP);
195 minorname = NULL;
196 if (ddi_dev_pathname(dev, otyp, physpath) == 0 &&
197 ldi_get_minor_name(dvd->vd_lh, &minorname) == 0 &&
198 (vd->vdev_physpath == NULL ||
199 strcmp(vd->vdev_physpath, physpath) != 0)) {
200 if (vd->vdev_physpath)
201 spa_strfree(vd->vdev_physpath);
202 (void) strlcat(physpath, ":", MAXPATHLEN);
203 (void) strlcat(physpath, minorname, MAXPATHLEN);
204 vd->vdev_physpath = spa_strdup(physpath);
205 }
206 if (minorname)
207 kmem_free(minorname, strlen(minorname) + 1);
208 kmem_free(physpath, MAXPATHLEN);
209 }
210
211 /*
212 * Determine the actual size of the device.
213 */
214 if (ldi_get_size(dvd->vd_lh, psize) != 0) {
215 vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
216 return (EINVAL);
217 }
218
219 /*
220 * If we own the whole disk, try to enable disk write caching.
221 * We ignore errors because it's OK if we can't do it.
222 */
223 if (vd->vdev_wholedisk == 1) {
224 int wce = 1;
225 (void) ldi_ioctl(dvd->vd_lh, DKIOCSETWCE, (intptr_t)&wce,
226 FKIOCTL, kcred, NULL);
227 }
228
229 /*
230 * Determine the device's minimum transfer size.
231 * If the ioctl isn't supported, assume DEV_BSIZE.
232 */
233 if (ldi_ioctl(dvd->vd_lh, DKIOCGMEDIAINFO, (intptr_t)&dkm,
234 FKIOCTL, kcred, NULL) != 0)
235 dkm.dki_lbsize = DEV_BSIZE;
236
237 *ashift = highbit(MAX(dkm.dki_lbsize, SPA_MINBLOCKSIZE)) - 1;
238
239 /*
240 * Clear the nowritecache bit, so that on a vdev_reopen() we will
241 * try again.
242 */
243 vd->vdev_nowritecache = B_FALSE;
244
245 return (0);
246 }
247
248 static void
249 vdev_disk_close(vdev_t *vd)
250 {
251 vdev_disk_t *dvd = vd->vdev_tsd;
252
253 if (dvd == NULL)
254 return;
255
256 if (dvd->vd_minor != NULL)
257 ddi_devid_str_free(dvd->vd_minor);
258
259 if (dvd->vd_devid != NULL)
260 ddi_devid_free(dvd->vd_devid);
261
262 if (dvd->vd_lh != NULL)
263 (void) ldi_close(dvd->vd_lh, spa_mode, kcred);
264
265 kmem_free(dvd, sizeof (vdev_disk_t));
266 vd->vdev_tsd = NULL;
267 }
268
269 static int
270 vdev_disk_probe_io(vdev_t *vd, caddr_t data, size_t size, uint64_t offset,
271 int flags)
272 {
273 buf_t buf;
274 int error = 0;
275 vdev_disk_t *dvd = vd->vdev_tsd;
276
277 if (vd == NULL || dvd == NULL || dvd->vd_lh == NULL)
278 return (EINVAL);
279
280 ASSERT(flags & B_READ || flags & B_WRITE);
281
282 bioinit(&buf);
283 buf.b_flags = flags | B_BUSY | B_NOCACHE | B_FAILFAST;
284 buf.b_bcount = size;
285 buf.b_un.b_addr = (void *)data;
286 buf.b_lblkno = lbtodb(offset);
287 buf.b_bufsize = size;
288
289 error = ldi_strategy(dvd->vd_lh, &buf);
290 ASSERT(error == 0);
291 error = biowait(&buf);
292
293 if (zio_injection_enabled && error == 0)
294 error = zio_handle_device_injection(vd, EIO);
295
296 return (error);
297 }
298
299 /*
300 * Determine if the underlying device is accessible by reading and writing
301 * to a known location. We must be able to do this during syncing context
302 * and thus we cannot set the vdev state directly.
303 */
304 static int
305 vdev_disk_probe(vdev_t *vd)
306 {
307 uint64_t offset;
308 vdev_t *nvd;
309 int l, error = 0, retries = 0;
310 char *vl_pad;
311
312 if (vd == NULL)
313 return (EINVAL);
314
315 /* Hijack the current vdev */
316 nvd = vd;
317
318 /*
319 * Pick a random label to rewrite.
320 */
321 l = spa_get_random(VDEV_LABELS);
322 ASSERT(l < VDEV_LABELS);
323
324 offset = vdev_label_offset(vd->vdev_psize, l,
325 offsetof(vdev_label_t, vl_pad));
326
327 vl_pad = kmem_alloc(VDEV_SKIP_SIZE, KM_SLEEP);
328
329 /*
330 * Try to read and write to a special location on the
331 * label. We use the existing vdev initially and only
332 * try to create and reopen it if we encounter a failure.
333 */
334 while ((error = vdev_disk_probe_io(nvd, vl_pad, VDEV_SKIP_SIZE,
335 offset, B_READ)) != 0 && retries == 0) {
336
337 nvd = kmem_zalloc(sizeof (vdev_t), KM_SLEEP);
338 if (vd->vdev_path)
339 nvd->vdev_path = spa_strdup(vd->vdev_path);
340 if (vd->vdev_physpath)
341 nvd->vdev_physpath = spa_strdup(vd->vdev_physpath);
342 if (vd->vdev_devid)
343 nvd->vdev_devid = spa_strdup(vd->vdev_devid);
344 nvd->vdev_wholedisk = vd->vdev_wholedisk;
345 nvd->vdev_guid = vd->vdev_guid;
346 retries++;
347
348 error = vdev_disk_open_common(nvd);
349 if (error)
350 break;
351 }
352
353 if (!error) {
354 error = vdev_disk_probe_io(nvd, vl_pad, VDEV_SKIP_SIZE,
355 offset, B_WRITE);
356 }
357
358 /* Clean up if we allocated a new vdev */
359 if (retries) {
360 vdev_disk_close(nvd);
361 if (nvd->vdev_path)
362 spa_strfree(nvd->vdev_path);
363 if (nvd->vdev_physpath)
364 spa_strfree(nvd->vdev_physpath);
365 if (nvd->vdev_devid)
366 spa_strfree(nvd->vdev_devid);
367 kmem_free(nvd, sizeof (vdev_t));
368 }
369 kmem_free(vl_pad, VDEV_SKIP_SIZE);
370
371 /* Reset the failing flag */
372 if (!error)
373 vd->vdev_is_failing = B_FALSE;
374
375 return (error);
376 }
377
378 static void
379 vdev_disk_io_intr(buf_t *bp)
380 {
381 vdev_disk_buf_t *vdb = (vdev_disk_buf_t *)bp;
382 zio_t *zio = vdb->vdb_io;
383
384 if ((zio->io_error = geterror(bp)) == 0 && bp->b_resid != 0)
385 zio->io_error = EIO;
386
387 kmem_free(vdb, sizeof (vdev_disk_buf_t));
388
389 zio_interrupt(zio);
390 }
391
392 static void
393 vdev_disk_ioctl_done(void *zio_arg, int error)
394 {
395 zio_t *zio = zio_arg;
396
397 zio->io_error = error;
398
399 zio_interrupt(zio);
400 }
401
402 static int
403 vdev_disk_io_start(zio_t *zio)
404 {
405 vdev_t *vd = zio->io_vd;
406 vdev_disk_t *dvd = vd->vdev_tsd;
407 vdev_disk_buf_t *vdb;
408 buf_t *bp;
409 int flags, error;
410
411 if (zio->io_type == ZIO_TYPE_IOCTL) {
412 zio_vdev_io_bypass(zio);
413
414 /* XXPOLICY */
415 if (!vdev_readable(vd)) {
416 zio->io_error = ENXIO;
417 return (ZIO_PIPELINE_CONTINUE);
418 }
419
420 switch (zio->io_cmd) {
421
422 case DKIOCFLUSHWRITECACHE:
423
424 if (zfs_nocacheflush)
425 break;
426
427 if (vd->vdev_nowritecache) {
428 zio->io_error = ENOTSUP;
429 break;
430 }
431
432 zio->io_dk_callback.dkc_callback = vdev_disk_ioctl_done;
433 zio->io_dk_callback.dkc_flag = FLUSH_VOLATILE;
434 zio->io_dk_callback.dkc_cookie = zio;
435
436 error = ldi_ioctl(dvd->vd_lh, zio->io_cmd,
437 (uintptr_t)&zio->io_dk_callback,
438 FKIOCTL, kcred, NULL);
439
440 if (error == 0) {
441 /*
442 * The ioctl will be done asychronously,
443 * and will call vdev_disk_ioctl_done()
444 * upon completion.
445 */
446 return (ZIO_PIPELINE_STOP);
447 }
448
449 if (error == ENOTSUP || error == ENOTTY) {
450 /*
451 * If we get ENOTSUP or ENOTTY, we know that
452 * no future attempts will ever succeed.
453 * In this case we set a persistent bit so
454 * that we don't bother with the ioctl in the
455 * future.
456 */
457 vd->vdev_nowritecache = B_TRUE;
458 }
459 zio->io_error = error;
460
461 break;
462
463 default:
464 zio->io_error = ENOTSUP;
465 }
466
467 return (ZIO_PIPELINE_CONTINUE);
468 }
469
470 if (zio->io_type == ZIO_TYPE_READ && vdev_cache_read(zio) == 0)
471 return (ZIO_PIPELINE_STOP);
472
473 if ((zio = vdev_queue_io(zio)) == NULL)
474 return (ZIO_PIPELINE_STOP);
475
476 if (zio->io_type == ZIO_TYPE_WRITE)
477 error = vdev_writeable(vd) ? vdev_error_inject(vd, zio) : ENXIO;
478 else
479 error = vdev_readable(vd) ? vdev_error_inject(vd, zio) : ENXIO;
480 error = (vd->vdev_remove_wanted || vd->vdev_is_failing) ? ENXIO : error;
481
482 if (error) {
483 zio->io_error = error;
484 zio_interrupt(zio);
485 return (ZIO_PIPELINE_STOP);
486 }
487
488 flags = (zio->io_type == ZIO_TYPE_READ ? B_READ : B_WRITE);
489 flags |= B_BUSY | B_NOCACHE;
490 if (zio->io_flags & ZIO_FLAG_FAILFAST)
491 flags |= B_FAILFAST;
492
493 vdb = kmem_alloc(sizeof (vdev_disk_buf_t), KM_SLEEP);
494
495 vdb->vdb_io = zio;
496 bp = &vdb->vdb_buf;
497
498 bioinit(bp);
499 bp->b_flags = flags;
500 bp->b_bcount = zio->io_size;
501 bp->b_un.b_addr = zio->io_data;
502 bp->b_lblkno = lbtodb(zio->io_offset);
503 bp->b_bufsize = zio->io_size;
504 bp->b_iodone = (int (*)())vdev_disk_io_intr;
505
506 error = ldi_strategy(dvd->vd_lh, bp);
507 /* ldi_strategy() will return non-zero only on programming errors */
508 ASSERT(error == 0);
509
510 return (ZIO_PIPELINE_STOP);
511 }
512
513 static int
514 vdev_disk_io_done(zio_t *zio)
515 {
516 vdev_queue_io_done(zio);
517
518 if (zio->io_type == ZIO_TYPE_WRITE)
519 vdev_cache_write(zio);
520
521 if (zio_injection_enabled && zio->io_error == 0)
522 zio->io_error = zio_handle_device_injection(zio->io_vd, EIO);
523
524 /*
525 * If the device returned EIO, then attempt a DKIOCSTATE ioctl to see if
526 * the device has been removed. If this is the case, then we trigger an
527 * asynchronous removal of the device. Otherwise, probe the device and
528 * make sure it's still accessible.
529 */
530 if (zio->io_error == EIO) {
531 vdev_t *vd = zio->io_vd;
532 vdev_disk_t *dvd = vd->vdev_tsd;
533 int state;
534
535 state = DKIO_NONE;
536 if (dvd && ldi_ioctl(dvd->vd_lh, DKIOCSTATE, (intptr_t)&state,
537 FKIOCTL, kcred, NULL) == 0 &&
538 state != DKIO_INSERTED) {
539 vd->vdev_remove_wanted = B_TRUE;
540 spa_async_request(zio->io_spa, SPA_ASYNC_REMOVE);
541 } else if (vdev_probe(vd) != 0) {
542 ASSERT(vd->vdev_ops->vdev_op_leaf);
543 vd->vdev_is_failing = B_TRUE;
544 }
545 }
546
547 return (ZIO_PIPELINE_CONTINUE);
548 }
549
550 vdev_ops_t vdev_disk_ops = {
551 vdev_disk_open,
552 vdev_disk_close,
553 vdev_disk_probe,
554 vdev_default_asize,
555 vdev_disk_io_start,
556 vdev_disk_io_done,
557 NULL,
558 NULL,
559 VDEV_TYPE_DISK, /* name of this vdev type */
560 B_TRUE /* leaf vdev */
561 };