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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 *
24 * Portions Copyright 2010 Robert Milkowski
25 *
26 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
27 * Copyright (c) 2012, 2017 by Delphix. All rights reserved.
28 * Copyright (c) 2013, Joyent, Inc. All rights reserved.
29 * Copyright (c) 2014 Integros [integros.com]
30 */
31
32 /*
33 * ZFS volume emulation driver.
34 *
35 * Makes a DMU object look like a volume of arbitrary size, up to 2^64 bytes.
36 * Volumes are accessed through the symbolic links named:
37 *
38 * /dev/zvol/dsk/<pool_name>/<dataset_name>
39 * /dev/zvol/rdsk/<pool_name>/<dataset_name>
40 *
41 * These links are created by the /dev filesystem (sdev_zvolops.c).
42 * Volumes are persistent through reboot. No user command needs to be
43 * run before opening and using a device.
44 */
45
46 #include <sys/types.h>
47 #include <sys/param.h>
48 #include <sys/errno.h>
49 #include <sys/uio.h>
50 #include <sys/buf.h>
51 #include <sys/modctl.h>
52 #include <sys/open.h>
53 #include <sys/kmem.h>
54 #include <sys/conf.h>
55 #include <sys/cmn_err.h>
56 #include <sys/stat.h>
57 #include <sys/zap.h>
58 #include <sys/spa.h>
59 #include <sys/spa_impl.h>
60 #include <sys/zio.h>
61 #include <sys/dmu_traverse.h>
62 #include <sys/dnode.h>
63 #include <sys/dsl_dataset.h>
64 #include <sys/dsl_prop.h>
65 #include <sys/dkio.h>
66 #include <sys/efi_partition.h>
67 #include <sys/byteorder.h>
68 #include <sys/pathname.h>
69 #include <sys/ddi.h>
70 #include <sys/sunddi.h>
71 #include <sys/crc32.h>
72 #include <sys/dirent.h>
73 #include <sys/policy.h>
74 #include <sys/fs/zfs.h>
75 #include <sys/zfs_ioctl.h>
76 #include <sys/mkdev.h>
77 #include <sys/zil.h>
78 #include <sys/refcount.h>
79 #include <sys/zfs_znode.h>
80 #include <sys/zfs_rlock.h>
81 #include <sys/vdev_disk.h>
82 #include <sys/vdev_impl.h>
83 #include <sys/vdev_raidz.h>
84 #include <sys/zvol.h>
85 #include <sys/dumphdr.h>
86 #include <sys/zil_impl.h>
87 #include <sys/dbuf.h>
88 #include <sys/dmu_tx.h>
89 #include <sys/zfeature.h>
90 #include <sys/zio_checksum.h>
91 #include <sys/zil_impl.h>
92
93 #include "zfs_namecheck.h"
94
95 void *zfsdev_state;
96 static char *zvol_tag = "zvol_tag";
97
98 #define ZVOL_DUMPSIZE "dumpsize"
99
100 /*
101 * This lock protects the zfsdev_state structure from being modified
102 * while it's being used, e.g. an open that comes in before a create
103 * finishes. It also protects temporary opens of the dataset so that,
104 * e.g., an open doesn't get a spurious EBUSY.
105 */
106 kmutex_t zfsdev_state_lock;
107 static uint32_t zvol_minors;
108
109 typedef struct zvol_extent {
110 list_node_t ze_node;
111 dva_t ze_dva; /* dva associated with this extent */
112 uint64_t ze_nblks; /* number of blocks in extent */
113 } zvol_extent_t;
114
115 /*
116 * The in-core state of each volume.
117 */
118 typedef struct zvol_state {
119 char zv_name[MAXPATHLEN]; /* pool/dd name */
120 uint64_t zv_volsize; /* amount of space we advertise */
121 uint64_t zv_volblocksize; /* volume block size */
122 minor_t zv_minor; /* minor number */
123 uint8_t zv_min_bs; /* minimum addressable block shift */
124 uint8_t zv_flags; /* readonly, dumpified, etc. */
125 objset_t *zv_objset; /* objset handle */
126 uint32_t zv_open_count[OTYPCNT]; /* open counts */
127 uint32_t zv_total_opens; /* total open count */
128 zilog_t *zv_zilog; /* ZIL handle */
129 list_t zv_extents; /* List of extents for dump */
130 znode_t zv_znode; /* for range locking */
131 dmu_buf_t *zv_dbuf; /* bonus handle */
132 } zvol_state_t;
133
134 /*
135 * zvol specific flags
136 */
137 #define ZVOL_RDONLY 0x1
138 #define ZVOL_DUMPIFIED 0x2
139 #define ZVOL_EXCL 0x4
140 #define ZVOL_WCE 0x8
141
142 /*
143 * zvol maximum transfer in one DMU tx.
144 */
145 int zvol_maxphys = DMU_MAX_ACCESS/2;
146
147 /*
148 * Toggle unmap functionality.
149 */
150 boolean_t zvol_unmap_enabled = B_TRUE;
151
152 /*
153 * If true, unmaps requested as synchronous are executed synchronously,
154 * otherwise all unmaps are asynchronous.
155 */
156 boolean_t zvol_unmap_sync_enabled = B_FALSE;
157
158 extern int zfs_set_prop_nvlist(const char *, zprop_source_t,
159 nvlist_t *, nvlist_t *);
160 static int zvol_remove_zv(zvol_state_t *);
161 static int zvol_get_data(void *arg, lr_write_t *lr, char *buf,
162 struct lwb *lwb, zio_t *zio);
163 static int zvol_dumpify(zvol_state_t *zv);
164 static int zvol_dump_fini(zvol_state_t *zv);
165 static int zvol_dump_init(zvol_state_t *zv, boolean_t resize);
166
167 static void
168 zvol_size_changed(zvol_state_t *zv, uint64_t volsize)
169 {
170 dev_t dev = makedevice(ddi_driver_major(zfs_dip), zv->zv_minor);
171
172 zv->zv_volsize = volsize;
173 VERIFY(ddi_prop_update_int64(dev, zfs_dip,
174 "Size", volsize) == DDI_SUCCESS);
175 VERIFY(ddi_prop_update_int64(dev, zfs_dip,
176 "Nblocks", lbtodb(volsize)) == DDI_SUCCESS);
177
178 /* Notify specfs to invalidate the cached size */
179 spec_size_invalidate(dev, VBLK);
180 spec_size_invalidate(dev, VCHR);
181 }
182
183 int
184 zvol_check_volsize(uint64_t volsize, uint64_t blocksize)
185 {
186 if (volsize == 0)
187 return (SET_ERROR(EINVAL));
188
189 if (volsize % blocksize != 0)
190 return (SET_ERROR(EINVAL));
191
192 #ifdef _ILP32
193 if (volsize - 1 > SPEC_MAXOFFSET_T)
194 return (SET_ERROR(EOVERFLOW));
195 #endif
196 return (0);
197 }
198
199 int
200 zvol_check_volblocksize(uint64_t volblocksize)
201 {
202 if (volblocksize < SPA_MINBLOCKSIZE ||
203 volblocksize > SPA_OLD_MAXBLOCKSIZE ||
204 !ISP2(volblocksize))
205 return (SET_ERROR(EDOM));
206
207 return (0);
208 }
209
210 int
211 zvol_get_stats(objset_t *os, nvlist_t *nv)
212 {
213 int error;
214 dmu_object_info_t doi;
215 uint64_t val;
216
217 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &val);
218 if (error)
219 return (error);
220
221 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLSIZE, val);
222
223 error = dmu_object_info(os, ZVOL_OBJ, &doi);
224
225 if (error == 0) {
226 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLBLOCKSIZE,
227 doi.doi_data_block_size);
228 }
229
230 return (error);
231 }
232
233 static zvol_state_t *
234 zvol_minor_lookup(const char *name)
235 {
236 minor_t minor;
237 zvol_state_t *zv;
238
239 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
240
241 for (minor = 1; minor <= ZFSDEV_MAX_MINOR; minor++) {
242 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
243 if (zv == NULL)
244 continue;
245 if (strcmp(zv->zv_name, name) == 0)
246 return (zv);
247 }
248
249 return (NULL);
250 }
251
252 /* extent mapping arg */
253 struct maparg {
254 zvol_state_t *ma_zv;
255 uint64_t ma_blks;
256 };
257
258 /*ARGSUSED*/
259 static int
260 zvol_map_block(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
261 const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
262 {
263 struct maparg *ma = arg;
264 zvol_extent_t *ze;
265 int bs = ma->ma_zv->zv_volblocksize;
266
267 if (bp == NULL || BP_IS_HOLE(bp) ||
268 zb->zb_object != ZVOL_OBJ || zb->zb_level != 0)
269 return (0);
270
271 VERIFY(!BP_IS_EMBEDDED(bp));
272
273 VERIFY3U(ma->ma_blks, ==, zb->zb_blkid);
274 ma->ma_blks++;
275
276 /* Abort immediately if we have encountered gang blocks */
277 if (BP_IS_GANG(bp))
278 return (SET_ERROR(EFRAGS));
279
280 /*
281 * See if the block is at the end of the previous extent.
282 */
283 ze = list_tail(&ma->ma_zv->zv_extents);
284 if (ze &&
285 DVA_GET_VDEV(BP_IDENTITY(bp)) == DVA_GET_VDEV(&ze->ze_dva) &&
286 DVA_GET_OFFSET(BP_IDENTITY(bp)) ==
287 DVA_GET_OFFSET(&ze->ze_dva) + ze->ze_nblks * bs) {
288 ze->ze_nblks++;
289 return (0);
290 }
291
292 dprintf_bp(bp, "%s", "next blkptr:");
293
294 /* start a new extent */
295 ze = kmem_zalloc(sizeof (zvol_extent_t), KM_SLEEP);
296 ze->ze_dva = bp->blk_dva[0]; /* structure assignment */
297 ze->ze_nblks = 1;
298 list_insert_tail(&ma->ma_zv->zv_extents, ze);
299 return (0);
300 }
301
302 static void
303 zvol_free_extents(zvol_state_t *zv)
304 {
305 zvol_extent_t *ze;
306
307 while (ze = list_head(&zv->zv_extents)) {
308 list_remove(&zv->zv_extents, ze);
309 kmem_free(ze, sizeof (zvol_extent_t));
310 }
311 }
312
313 static int
314 zvol_get_lbas(zvol_state_t *zv)
315 {
316 objset_t *os = zv->zv_objset;
317 struct maparg ma;
318 int err;
319
320 ma.ma_zv = zv;
321 ma.ma_blks = 0;
322 zvol_free_extents(zv);
323
324 /* commit any in-flight changes before traversing the dataset */
325 txg_wait_synced(dmu_objset_pool(os), 0);
326 err = traverse_dataset(dmu_objset_ds(os), 0,
327 TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA, zvol_map_block, &ma);
328 if (err || ma.ma_blks != (zv->zv_volsize / zv->zv_volblocksize)) {
329 zvol_free_extents(zv);
330 return (err ? err : EIO);
331 }
332
333 return (0);
334 }
335
336 /* ARGSUSED */
337 void
338 zvol_create_cb(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx)
339 {
340 zfs_creat_t *zct = arg;
341 nvlist_t *nvprops = zct->zct_props;
342 int error;
343 uint64_t volblocksize, volsize;
344
345 VERIFY(nvlist_lookup_uint64(nvprops,
346 zfs_prop_to_name(ZFS_PROP_VOLSIZE), &volsize) == 0);
347 if (nvlist_lookup_uint64(nvprops,
348 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &volblocksize) != 0)
349 volblocksize = zfs_prop_default_numeric(ZFS_PROP_VOLBLOCKSIZE);
350
351 /*
352 * These properties must be removed from the list so the generic
353 * property setting step won't apply to them.
354 */
355 VERIFY(nvlist_remove_all(nvprops,
356 zfs_prop_to_name(ZFS_PROP_VOLSIZE)) == 0);
357 (void) nvlist_remove_all(nvprops,
358 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE));
359
360 error = dmu_object_claim(os, ZVOL_OBJ, DMU_OT_ZVOL, volblocksize,
361 DMU_OT_NONE, 0, tx);
362 ASSERT(error == 0);
363
364 error = zap_create_claim(os, ZVOL_ZAP_OBJ, DMU_OT_ZVOL_PROP,
365 DMU_OT_NONE, 0, tx);
366 ASSERT(error == 0);
367
368 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize, tx);
369 ASSERT(error == 0);
370 }
371
372 /*
373 * Replay a TX_TRUNCATE ZIL transaction if asked. TX_TRUNCATE is how we
374 * implement DKIOCFREE/free-long-range.
375 */
376 static int
377 zvol_replay_truncate(void *arg1, void *arg2, boolean_t byteswap)
378 {
379 zvol_state_t *zv = arg1;
380 lr_truncate_t *lr = arg2;
381 uint64_t offset, length;
382
383 if (byteswap)
384 byteswap_uint64_array(lr, sizeof (*lr));
385
386 offset = lr->lr_offset;
387 length = lr->lr_length;
388
389 return (dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, offset, length));
390 }
391
392 /*
393 * Replay a TX_WRITE ZIL transaction that didn't get committed
394 * after a system failure
395 */
396 static int
397 zvol_replay_write(void *arg1, void *arg2, boolean_t byteswap)
398 {
399 zvol_state_t *zv = arg1;
400 lr_write_t *lr = arg2;
401 objset_t *os = zv->zv_objset;
402 char *data = (char *)(lr + 1); /* data follows lr_write_t */
403 uint64_t offset, length;
404 dmu_tx_t *tx;
405 int error;
406
407 if (byteswap)
408 byteswap_uint64_array(lr, sizeof (*lr));
409
410 offset = lr->lr_offset;
411 length = lr->lr_length;
412
413 /* If it's a dmu_sync() block, write the whole block */
414 if (lr->lr_common.lrc_reclen == sizeof (lr_write_t)) {
415 uint64_t blocksize = BP_GET_LSIZE(&lr->lr_blkptr);
416 if (length < blocksize) {
417 offset -= offset % blocksize;
418 length = blocksize;
419 }
420 }
421
422 tx = dmu_tx_create(os);
423 dmu_tx_hold_write(tx, ZVOL_OBJ, offset, length);
424 error = dmu_tx_assign(tx, TXG_WAIT);
425 if (error) {
426 dmu_tx_abort(tx);
427 } else {
428 dmu_write(os, ZVOL_OBJ, offset, length, data, tx);
429 dmu_tx_commit(tx);
430 }
431
432 return (error);
433 }
434
435 /* ARGSUSED */
436 static int
437 zvol_replay_err(void *arg1, void *arg2, boolean_t byteswap)
438 {
439 return (SET_ERROR(ENOTSUP));
440 }
441
442 /*
443 * Callback vectors for replaying records.
444 * Only TX_WRITE and TX_TRUNCATE are needed for zvol.
445 */
446 zil_replay_func_t *zvol_replay_vector[TX_MAX_TYPE] = {
447 zvol_replay_err, /* 0 no such transaction type */
448 zvol_replay_err, /* TX_CREATE */
449 zvol_replay_err, /* TX_MKDIR */
450 zvol_replay_err, /* TX_MKXATTR */
451 zvol_replay_err, /* TX_SYMLINK */
452 zvol_replay_err, /* TX_REMOVE */
453 zvol_replay_err, /* TX_RMDIR */
454 zvol_replay_err, /* TX_LINK */
455 zvol_replay_err, /* TX_RENAME */
456 zvol_replay_write, /* TX_WRITE */
457 zvol_replay_truncate, /* TX_TRUNCATE */
458 zvol_replay_err, /* TX_SETATTR */
459 zvol_replay_err, /* TX_ACL */
460 zvol_replay_err, /* TX_CREATE_ACL */
461 zvol_replay_err, /* TX_CREATE_ATTR */
462 zvol_replay_err, /* TX_CREATE_ACL_ATTR */
463 zvol_replay_err, /* TX_MKDIR_ACL */
464 zvol_replay_err, /* TX_MKDIR_ATTR */
465 zvol_replay_err, /* TX_MKDIR_ACL_ATTR */
466 zvol_replay_err, /* TX_WRITE2 */
467 };
468
469 int
470 zvol_name2minor(const char *name, minor_t *minor)
471 {
472 zvol_state_t *zv;
473
474 mutex_enter(&zfsdev_state_lock);
475 zv = zvol_minor_lookup(name);
476 if (minor && zv)
477 *minor = zv->zv_minor;
478 mutex_exit(&zfsdev_state_lock);
479 return (zv ? 0 : -1);
480 }
481
482 /*
483 * Create a minor node (plus a whole lot more) for the specified volume.
484 */
485 int
486 zvol_create_minor(const char *name)
487 {
488 zfs_soft_state_t *zs;
489 zvol_state_t *zv;
490 objset_t *os;
491 dmu_object_info_t doi;
492 minor_t minor = 0;
493 char chrbuf[30], blkbuf[30];
494 int error;
495
496 mutex_enter(&zfsdev_state_lock);
497
498 if (zvol_minor_lookup(name) != NULL) {
499 mutex_exit(&zfsdev_state_lock);
500 return (SET_ERROR(EEXIST));
501 }
502
503 /* lie and say we're read-only */
504 error = dmu_objset_own(name, DMU_OST_ZVOL, B_TRUE, FTAG, &os);
505
506 if (error) {
507 mutex_exit(&zfsdev_state_lock);
508 return (error);
509 }
510
511 if ((minor = zfsdev_minor_alloc()) == 0) {
512 dmu_objset_disown(os, FTAG);
513 mutex_exit(&zfsdev_state_lock);
514 return (SET_ERROR(ENXIO));
515 }
516
517 if (ddi_soft_state_zalloc(zfsdev_state, minor) != DDI_SUCCESS) {
518 dmu_objset_disown(os, FTAG);
519 mutex_exit(&zfsdev_state_lock);
520 return (SET_ERROR(EAGAIN));
521 }
522 (void) ddi_prop_update_string(minor, zfs_dip, ZVOL_PROP_NAME,
523 (char *)name);
524
525 (void) snprintf(chrbuf, sizeof (chrbuf), "%u,raw", minor);
526
527 if (ddi_create_minor_node(zfs_dip, chrbuf, S_IFCHR,
528 minor, DDI_PSEUDO, 0) == DDI_FAILURE) {
529 ddi_soft_state_free(zfsdev_state, minor);
530 dmu_objset_disown(os, FTAG);
531 mutex_exit(&zfsdev_state_lock);
532 return (SET_ERROR(EAGAIN));
533 }
534
535 (void) snprintf(blkbuf, sizeof (blkbuf), "%u", minor);
536
537 if (ddi_create_minor_node(zfs_dip, blkbuf, S_IFBLK,
538 minor, DDI_PSEUDO, 0) == DDI_FAILURE) {
539 ddi_remove_minor_node(zfs_dip, chrbuf);
540 ddi_soft_state_free(zfsdev_state, minor);
541 dmu_objset_disown(os, FTAG);
542 mutex_exit(&zfsdev_state_lock);
543 return (SET_ERROR(EAGAIN));
544 }
545
546 zs = ddi_get_soft_state(zfsdev_state, minor);
547 zs->zss_type = ZSST_ZVOL;
548 zv = zs->zss_data = kmem_zalloc(sizeof (zvol_state_t), KM_SLEEP);
549 (void) strlcpy(zv->zv_name, name, MAXPATHLEN);
550 zv->zv_min_bs = DEV_BSHIFT;
551 zv->zv_minor = minor;
552 zv->zv_objset = os;
553 if (dmu_objset_is_snapshot(os) || !spa_writeable(dmu_objset_spa(os)))
554 zv->zv_flags |= ZVOL_RDONLY;
555 mutex_init(&zv->zv_znode.z_range_lock, NULL, MUTEX_DEFAULT, NULL);
556 avl_create(&zv->zv_znode.z_range_avl, zfs_range_compare,
557 sizeof (rl_t), offsetof(rl_t, r_node));
558 list_create(&zv->zv_extents, sizeof (zvol_extent_t),
559 offsetof(zvol_extent_t, ze_node));
560 /* get and cache the blocksize */
561 error = dmu_object_info(os, ZVOL_OBJ, &doi);
562 ASSERT(error == 0);
563 zv->zv_volblocksize = doi.doi_data_block_size;
564
565 if (spa_writeable(dmu_objset_spa(os))) {
566 if (zil_replay_disable)
567 zil_destroy(dmu_objset_zil(os), B_FALSE);
568 else
569 zil_replay(os, zv, zvol_replay_vector);
570 }
571 dmu_objset_disown(os, FTAG);
572 zv->zv_objset = NULL;
573
574 zvol_minors++;
575
576 mutex_exit(&zfsdev_state_lock);
577
578 return (0);
579 }
580
581 /*
582 * Remove minor node for the specified volume.
583 */
584 static int
585 zvol_remove_zv(zvol_state_t *zv)
586 {
587 char nmbuf[20];
588 minor_t minor = zv->zv_minor;
589
590 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
591 if (zv->zv_total_opens != 0)
592 return (SET_ERROR(EBUSY));
593
594 (void) snprintf(nmbuf, sizeof (nmbuf), "%u,raw", minor);
595 ddi_remove_minor_node(zfs_dip, nmbuf);
596
597 (void) snprintf(nmbuf, sizeof (nmbuf), "%u", minor);
598 ddi_remove_minor_node(zfs_dip, nmbuf);
599
600 avl_destroy(&zv->zv_znode.z_range_avl);
601 mutex_destroy(&zv->zv_znode.z_range_lock);
602
603 kmem_free(zv, sizeof (zvol_state_t));
604
605 ddi_soft_state_free(zfsdev_state, minor);
606
607 zvol_minors--;
608 return (0);
609 }
610
611 int
612 zvol_remove_minor(const char *name)
613 {
614 zvol_state_t *zv;
615 int rc;
616
617 mutex_enter(&zfsdev_state_lock);
618 if ((zv = zvol_minor_lookup(name)) == NULL) {
619 mutex_exit(&zfsdev_state_lock);
620 return (SET_ERROR(ENXIO));
621 }
622 rc = zvol_remove_zv(zv);
623 mutex_exit(&zfsdev_state_lock);
624 return (rc);
625 }
626
627 int
628 zvol_first_open(zvol_state_t *zv)
629 {
630 objset_t *os;
631 uint64_t volsize;
632 int error;
633 uint64_t readonly;
634
635 /* lie and say we're read-only */
636 error = dmu_objset_own(zv->zv_name, DMU_OST_ZVOL, B_TRUE,
637 zvol_tag, &os);
638 if (error)
639 return (error);
640
641 zv->zv_objset = os;
642 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize);
643 if (error) {
644 ASSERT(error == 0);
645 dmu_objset_disown(os, zvol_tag);
646 return (error);
647 }
648
649 error = dmu_bonus_hold(os, ZVOL_OBJ, zvol_tag, &zv->zv_dbuf);
650 if (error) {
651 dmu_objset_disown(os, zvol_tag);
652 return (error);
653 }
654
655 zvol_size_changed(zv, volsize);
656 zv->zv_zilog = zil_open(os, zvol_get_data);
657
658 VERIFY(dsl_prop_get_integer(zv->zv_name, "readonly", &readonly,
659 NULL) == 0);
660 if (readonly || dmu_objset_is_snapshot(os) ||
661 !spa_writeable(dmu_objset_spa(os)))
662 zv->zv_flags |= ZVOL_RDONLY;
663 else
664 zv->zv_flags &= ~ZVOL_RDONLY;
665 return (error);
666 }
667
668 void
669 zvol_last_close(zvol_state_t *zv)
670 {
671 zil_close(zv->zv_zilog);
672 zv->zv_zilog = NULL;
673
674 dmu_buf_rele(zv->zv_dbuf, zvol_tag);
675 zv->zv_dbuf = NULL;
676
677 /*
678 * Evict cached data
679 */
680 if (dsl_dataset_is_dirty(dmu_objset_ds(zv->zv_objset)) &&
681 !(zv->zv_flags & ZVOL_RDONLY))
682 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
683 dmu_objset_evict_dbufs(zv->zv_objset);
684
685 dmu_objset_disown(zv->zv_objset, zvol_tag);
686 zv->zv_objset = NULL;
687 }
688
689 int
690 zvol_prealloc(zvol_state_t *zv)
691 {
692 objset_t *os = zv->zv_objset;
693 dmu_tx_t *tx;
694 uint64_t refd, avail, usedobjs, availobjs;
695 uint64_t resid = zv->zv_volsize;
696 uint64_t off = 0;
697
698 /* Check the space usage before attempting to allocate the space */
699 dmu_objset_space(os, &refd, &avail, &usedobjs, &availobjs);
700 if (avail < zv->zv_volsize)
701 return (SET_ERROR(ENOSPC));
702
703 /* Free old extents if they exist */
704 zvol_free_extents(zv);
705
706 while (resid != 0) {
707 int error;
708 uint64_t bytes = MIN(resid, SPA_OLD_MAXBLOCKSIZE);
709
710 tx = dmu_tx_create(os);
711 dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes);
712 error = dmu_tx_assign(tx, TXG_WAIT);
713 if (error) {
714 dmu_tx_abort(tx);
715 (void) dmu_free_long_range(os, ZVOL_OBJ, 0, off);
716 return (error);
717 }
718 dmu_prealloc(os, ZVOL_OBJ, off, bytes, tx);
719 dmu_tx_commit(tx);
720 off += bytes;
721 resid -= bytes;
722 }
723 txg_wait_synced(dmu_objset_pool(os), 0);
724
725 return (0);
726 }
727
728 static int
729 zvol_update_volsize(objset_t *os, uint64_t volsize)
730 {
731 dmu_tx_t *tx;
732 int error;
733
734 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
735
736 tx = dmu_tx_create(os);
737 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
738 dmu_tx_mark_netfree(tx);
739 error = dmu_tx_assign(tx, TXG_WAIT);
740 if (error) {
741 dmu_tx_abort(tx);
742 return (error);
743 }
744
745 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1,
746 &volsize, tx);
747 dmu_tx_commit(tx);
748
749 if (error == 0)
750 error = dmu_free_long_range(os,
751 ZVOL_OBJ, volsize, DMU_OBJECT_END);
752 return (error);
753 }
754
755 void
756 zvol_remove_minors(const char *name)
757 {
758 zvol_state_t *zv;
759 char *namebuf;
760 minor_t minor;
761
762 namebuf = kmem_zalloc(strlen(name) + 2, KM_SLEEP);
763 (void) strncpy(namebuf, name, strlen(name));
764 (void) strcat(namebuf, "/");
765 mutex_enter(&zfsdev_state_lock);
766 for (minor = 1; minor <= ZFSDEV_MAX_MINOR; minor++) {
767
768 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
769 if (zv == NULL)
770 continue;
771 if (strncmp(namebuf, zv->zv_name, strlen(namebuf)) == 0)
772 (void) zvol_remove_zv(zv);
773 }
774 kmem_free(namebuf, strlen(name) + 2);
775
776 mutex_exit(&zfsdev_state_lock);
777 }
778
779 static int
780 zvol_update_live_volsize(zvol_state_t *zv, uint64_t volsize)
781 {
782 uint64_t old_volsize = 0ULL;
783 int error = 0;
784
785 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
786
787 /*
788 * Reinitialize the dump area to the new size. If we
789 * failed to resize the dump area then restore it back to
790 * its original size. We must set the new volsize prior
791 * to calling dumpvp_resize() to ensure that the devices'
792 * size(9P) is not visible by the dump subsystem.
793 */
794 old_volsize = zv->zv_volsize;
795 zvol_size_changed(zv, volsize);
796
797 if (zv->zv_flags & ZVOL_DUMPIFIED) {
798 if ((error = zvol_dumpify(zv)) != 0 ||
799 (error = dumpvp_resize()) != 0) {
800 int dumpify_error;
801
802 (void) zvol_update_volsize(zv->zv_objset, old_volsize);
803 zvol_size_changed(zv, old_volsize);
804 dumpify_error = zvol_dumpify(zv);
805 error = dumpify_error ? dumpify_error : error;
806 }
807 }
808
809 /*
810 * Generate a LUN expansion event.
811 */
812 if (error == 0) {
813 sysevent_id_t eid;
814 nvlist_t *attr;
815 char *physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
816
817 (void) snprintf(physpath, MAXPATHLEN, "%s%u", ZVOL_PSEUDO_DEV,
818 zv->zv_minor);
819
820 VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0);
821 VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0);
822
823 (void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS,
824 ESC_DEV_DLE, attr, &eid, DDI_SLEEP);
825
826 nvlist_free(attr);
827 kmem_free(physpath, MAXPATHLEN);
828 }
829 return (error);
830 }
831
832 int
833 zvol_set_volsize(const char *name, uint64_t volsize)
834 {
835 zvol_state_t *zv = NULL;
836 objset_t *os;
837 int error;
838 dmu_object_info_t doi;
839 uint64_t readonly;
840 boolean_t owned = B_FALSE;
841
842 error = dsl_prop_get_integer(name,
843 zfs_prop_to_name(ZFS_PROP_READONLY), &readonly, NULL);
844 if (error != 0)
845 return (error);
846 if (readonly)
847 return (SET_ERROR(EROFS));
848
849 mutex_enter(&zfsdev_state_lock);
850 zv = zvol_minor_lookup(name);
851
852 if (zv == NULL || zv->zv_objset == NULL) {
853 if ((error = dmu_objset_own(name, DMU_OST_ZVOL, B_FALSE,
854 FTAG, &os)) != 0) {
855 mutex_exit(&zfsdev_state_lock);
856 return (error);
857 }
858 owned = B_TRUE;
859 if (zv != NULL)
860 zv->zv_objset = os;
861 } else {
862 os = zv->zv_objset;
863 }
864
865 if ((error = dmu_object_info(os, ZVOL_OBJ, &doi)) != 0 ||
866 (error = zvol_check_volsize(volsize, doi.doi_data_block_size)) != 0)
867 goto out;
868
869 error = zvol_update_volsize(os, volsize);
870
871 if (error == 0 && zv != NULL)
872 error = zvol_update_live_volsize(zv, volsize);
873 out:
874 if (owned) {
875 dmu_objset_disown(os, FTAG);
876 if (zv != NULL)
877 zv->zv_objset = NULL;
878 }
879 mutex_exit(&zfsdev_state_lock);
880 return (error);
881 }
882
883 /*ARGSUSED*/
884 int
885 zvol_open(dev_t *devp, int flag, int otyp, cred_t *cr)
886 {
887 zvol_state_t *zv;
888 int err = 0;
889
890 mutex_enter(&zfsdev_state_lock);
891
892 zv = zfsdev_get_soft_state(getminor(*devp), ZSST_ZVOL);
893 if (zv == NULL) {
894 mutex_exit(&zfsdev_state_lock);
895 return (SET_ERROR(ENXIO));
896 }
897
898 if (zv->zv_total_opens == 0)
899 err = zvol_first_open(zv);
900 if (err) {
901 mutex_exit(&zfsdev_state_lock);
902 return (err);
903 }
904 if ((flag & FWRITE) && (zv->zv_flags & ZVOL_RDONLY)) {
905 err = SET_ERROR(EROFS);
906 goto out;
907 }
908 if (zv->zv_flags & ZVOL_EXCL) {
909 err = SET_ERROR(EBUSY);
910 goto out;
911 }
912 if (flag & FEXCL) {
913 if (zv->zv_total_opens != 0) {
914 err = SET_ERROR(EBUSY);
915 goto out;
916 }
917 zv->zv_flags |= ZVOL_EXCL;
918 }
919
920 if (zv->zv_open_count[otyp] == 0 || otyp == OTYP_LYR) {
921 zv->zv_open_count[otyp]++;
922 zv->zv_total_opens++;
923 }
924 mutex_exit(&zfsdev_state_lock);
925
926 return (err);
927 out:
928 if (zv->zv_total_opens == 0)
929 zvol_last_close(zv);
930 mutex_exit(&zfsdev_state_lock);
931 return (err);
932 }
933
934 /*ARGSUSED*/
935 int
936 zvol_close(dev_t dev, int flag, int otyp, cred_t *cr)
937 {
938 minor_t minor = getminor(dev);
939 zvol_state_t *zv;
940 int error = 0;
941
942 mutex_enter(&zfsdev_state_lock);
943
944 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
945 if (zv == NULL) {
946 mutex_exit(&zfsdev_state_lock);
947 return (SET_ERROR(ENXIO));
948 }
949
950 if (zv->zv_flags & ZVOL_EXCL) {
951 ASSERT(zv->zv_total_opens == 1);
952 zv->zv_flags &= ~ZVOL_EXCL;
953 }
954
955 /*
956 * If the open count is zero, this is a spurious close.
957 * That indicates a bug in the kernel / DDI framework.
958 */
959 ASSERT(zv->zv_open_count[otyp] != 0);
960 ASSERT(zv->zv_total_opens != 0);
961
962 /*
963 * You may get multiple opens, but only one close.
964 */
965 zv->zv_open_count[otyp]--;
966 zv->zv_total_opens--;
967
968 if (zv->zv_total_opens == 0)
969 zvol_last_close(zv);
970
971 mutex_exit(&zfsdev_state_lock);
972 return (error);
973 }
974
975 static void
976 zvol_get_done(zgd_t *zgd, int error)
977 {
978 if (zgd->zgd_db)
979 dmu_buf_rele(zgd->zgd_db, zgd);
980
981 zfs_range_unlock(zgd->zgd_rl);
982
983 if (error == 0 && zgd->zgd_bp)
984 zil_lwb_add_block(zgd->zgd_lwb, zgd->zgd_bp);
985
986 kmem_free(zgd, sizeof (zgd_t));
987 }
988
989 /*
990 * Get data to generate a TX_WRITE intent log record.
991 */
992 static int
993 zvol_get_data(void *arg, lr_write_t *lr, char *buf, struct lwb *lwb, zio_t *zio)
994 {
995 zvol_state_t *zv = arg;
996 objset_t *os = zv->zv_objset;
997 uint64_t object = ZVOL_OBJ;
998 uint64_t offset = lr->lr_offset;
999 uint64_t size = lr->lr_length; /* length of user data */
1000 dmu_buf_t *db;
1001 zgd_t *zgd;
1002 int error;
1003
1004 ASSERT3P(lwb, !=, NULL);
1005 ASSERT3P(zio, !=, NULL);
1006 ASSERT3U(size, !=, 0);
1007
1008 zgd = kmem_zalloc(sizeof (zgd_t), KM_SLEEP);
1009 zgd->zgd_lwb = lwb;
1010
1011 /*
1012 * Write records come in two flavors: immediate and indirect.
1013 * For small writes it's cheaper to store the data with the
1014 * log record (immediate); for large writes it's cheaper to
1015 * sync the data and get a pointer to it (indirect) so that
1016 * we don't have to write the data twice.
1017 */
1018 if (buf != NULL) { /* immediate write */
1019 zgd->zgd_rl = zfs_range_lock(&zv->zv_znode, offset, size,
1020 RL_READER);
1021 error = dmu_read(os, object, offset, size, buf,
1022 DMU_READ_NO_PREFETCH);
1023 } else { /* indirect write */
1024 /*
1025 * Have to lock the whole block to ensure when it's written out
1026 * and its checksum is being calculated that no one can change
1027 * the data. Contrarily to zfs_get_data we need not re-check
1028 * blocksize after we get the lock because it cannot be changed.
1029 */
1030 size = zv->zv_volblocksize;
1031 offset = P2ALIGN(offset, size);
1032 zgd->zgd_rl = zfs_range_lock(&zv->zv_znode, offset, size,
1033 RL_READER);
1034 error = dmu_buf_hold(os, object, offset, zgd, &db,
1035 DMU_READ_NO_PREFETCH);
1036 if (error == 0) {
1037 blkptr_t *bp = &lr->lr_blkptr;
1038
1039 zgd->zgd_db = db;
1040 zgd->zgd_bp = bp;
1041
1042 ASSERT(db->db_offset == offset);
1043 ASSERT(db->db_size == size);
1044
1045 error = dmu_sync(zio, lr->lr_common.lrc_txg,
1046 zvol_get_done, zgd);
1047
1048 if (error == 0)
1049 return (0);
1050 }
1051 }
1052
1053 zvol_get_done(zgd, error);
1054
1055 return (error);
1056 }
1057
1058 /*
1059 * zvol_log_write() handles synchronous writes using TX_WRITE ZIL transactions.
1060 *
1061 * We store data in the log buffers if it's small enough.
1062 * Otherwise we will later flush the data out via dmu_sync().
1063 */
1064 ssize_t zvol_immediate_write_sz = 32768;
1065
1066 static void
1067 zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, offset_t off, ssize_t resid,
1068 boolean_t sync)
1069 {
1070 uint32_t blocksize = zv->zv_volblocksize;
1071 zilog_t *zilog = zv->zv_zilog;
1072 itx_wr_state_t write_state;
1073
1074 if (zil_replaying(zilog, tx))
1075 return;
1076
1077 if (zilog->zl_logbias == ZFS_LOGBIAS_THROUGHPUT)
1078 write_state = WR_INDIRECT;
1079 else if (!spa_has_slogs(zilog->zl_spa) &&
1080 resid >= blocksize && blocksize > zvol_immediate_write_sz)
1081 write_state = WR_INDIRECT;
1082 else if (sync)
1083 write_state = WR_COPIED;
1084 else
1085 write_state = WR_NEED_COPY;
1086
1087 while (resid) {
1088 itx_t *itx;
1089 lr_write_t *lr;
1090 itx_wr_state_t wr_state = write_state;
1091 ssize_t len = resid;
1092
1093 if (wr_state == WR_COPIED && resid > ZIL_MAX_COPIED_DATA)
1094 wr_state = WR_NEED_COPY;
1095 else if (wr_state == WR_INDIRECT)
1096 len = MIN(blocksize - P2PHASE(off, blocksize), resid);
1097
1098 itx = zil_itx_create(TX_WRITE, sizeof (*lr) +
1099 (wr_state == WR_COPIED ? len : 0));
1100 lr = (lr_write_t *)&itx->itx_lr;
1101 if (wr_state == WR_COPIED && dmu_read(zv->zv_objset,
1102 ZVOL_OBJ, off, len, lr + 1, DMU_READ_NO_PREFETCH) != 0) {
1103 zil_itx_destroy(itx);
1104 itx = zil_itx_create(TX_WRITE, sizeof (*lr));
1105 lr = (lr_write_t *)&itx->itx_lr;
1106 wr_state = WR_NEED_COPY;
1107 }
1108
1109 itx->itx_wr_state = wr_state;
1110 lr->lr_foid = ZVOL_OBJ;
1111 lr->lr_offset = off;
1112 lr->lr_length = len;
1113 lr->lr_blkoff = 0;
1114 BP_ZERO(&lr->lr_blkptr);
1115
1116 itx->itx_private = zv;
1117 itx->itx_sync = sync;
1118
1119 zil_itx_assign(zilog, itx, tx);
1120
1121 off += len;
1122 resid -= len;
1123 }
1124 }
1125
1126 static int
1127 zvol_dumpio_vdev(vdev_t *vd, void *addr, uint64_t offset, uint64_t origoffset,
1128 uint64_t size, boolean_t doread, boolean_t isdump)
1129 {
1130 vdev_disk_t *dvd;
1131 int c;
1132 int numerrors = 0;
1133
1134 if (vd->vdev_ops == &vdev_mirror_ops ||
1135 vd->vdev_ops == &vdev_replacing_ops ||
1136 vd->vdev_ops == &vdev_spare_ops) {
1137 for (c = 0; c < vd->vdev_children; c++) {
1138 int err = zvol_dumpio_vdev(vd->vdev_child[c],
1139 addr, offset, origoffset, size, doread, isdump);
1140 if (err != 0) {
1141 numerrors++;
1142 } else if (doread) {
1143 break;
1144 }
1145 }
1146 }
1147
1148 if (!vd->vdev_ops->vdev_op_leaf && vd->vdev_ops != &vdev_raidz_ops)
1149 return (numerrors < vd->vdev_children ? 0 : EIO);
1150
1151 if (doread && !vdev_readable(vd))
1152 return (SET_ERROR(EIO));
1153 else if (!doread && !vdev_writeable(vd))
1154 return (SET_ERROR(EIO));
1155
1156 if (vd->vdev_ops == &vdev_raidz_ops) {
1157 return (vdev_raidz_physio(vd,
1158 addr, size, offset, origoffset, doread, isdump));
1159 }
1160
1161 offset += VDEV_LABEL_START_SIZE;
1162
1163 if (ddi_in_panic() || isdump) {
1164 ASSERT(!doread);
1165 if (doread)
1166 return (SET_ERROR(EIO));
1167 dvd = vd->vdev_tsd;
1168 ASSERT3P(dvd, !=, NULL);
1169 return (ldi_dump(dvd->vd_lh, addr, lbtodb(offset),
1170 lbtodb(size)));
1171 } else {
1172 dvd = vd->vdev_tsd;
1173 ASSERT3P(dvd, !=, NULL);
1174 return (vdev_disk_ldi_physio(dvd->vd_lh, addr, size,
1175 offset, doread ? B_READ : B_WRITE));
1176 }
1177 }
1178
1179 static int
1180 zvol_dumpio(zvol_state_t *zv, void *addr, uint64_t offset, uint64_t size,
1181 boolean_t doread, boolean_t isdump)
1182 {
1183 vdev_t *vd;
1184 int error;
1185 zvol_extent_t *ze;
1186 spa_t *spa = dmu_objset_spa(zv->zv_objset);
1187
1188 /* Must be sector aligned, and not stradle a block boundary. */
1189 if (P2PHASE(offset, DEV_BSIZE) || P2PHASE(size, DEV_BSIZE) ||
1190 P2BOUNDARY(offset, size, zv->zv_volblocksize)) {
1191 return (SET_ERROR(EINVAL));
1192 }
1193 ASSERT(size <= zv->zv_volblocksize);
1194
1195 /* Locate the extent this belongs to */
1196 ze = list_head(&zv->zv_extents);
1197 while (offset >= ze->ze_nblks * zv->zv_volblocksize) {
1198 offset -= ze->ze_nblks * zv->zv_volblocksize;
1199 ze = list_next(&zv->zv_extents, ze);
1200 }
1201
1202 if (ze == NULL)
1203 return (SET_ERROR(EINVAL));
1204
1205 if (!ddi_in_panic())
1206 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
1207
1208 vd = vdev_lookup_top(spa, DVA_GET_VDEV(&ze->ze_dva));
1209 offset += DVA_GET_OFFSET(&ze->ze_dva);
1210 error = zvol_dumpio_vdev(vd, addr, offset, DVA_GET_OFFSET(&ze->ze_dva),
1211 size, doread, isdump);
1212
1213 if (!ddi_in_panic())
1214 spa_config_exit(spa, SCL_STATE, FTAG);
1215
1216 return (error);
1217 }
1218
1219 int
1220 zvol_strategy(buf_t *bp)
1221 {
1222 zfs_soft_state_t *zs = NULL;
1223 zvol_state_t *zv;
1224 uint64_t off, volsize;
1225 size_t resid;
1226 char *addr;
1227 objset_t *os;
1228 rl_t *rl;
1229 int error = 0;
1230 boolean_t doread = bp->b_flags & B_READ;
1231 boolean_t is_dumpified;
1232 boolean_t sync;
1233
1234 if (getminor(bp->b_edev) == 0) {
1235 error = SET_ERROR(EINVAL);
1236 } else {
1237 zs = ddi_get_soft_state(zfsdev_state, getminor(bp->b_edev));
1238 if (zs == NULL)
1239 error = SET_ERROR(ENXIO);
1240 else if (zs->zss_type != ZSST_ZVOL)
1241 error = SET_ERROR(EINVAL);
1242 }
1243
1244 if (error) {
1245 bioerror(bp, error);
1246 biodone(bp);
1247 return (0);
1248 }
1249
1250 zv = zs->zss_data;
1251
1252 if (!(bp->b_flags & B_READ) && (zv->zv_flags & ZVOL_RDONLY)) {
1253 bioerror(bp, EROFS);
1254 biodone(bp);
1255 return (0);
1256 }
1257
1258 off = ldbtob(bp->b_blkno);
1259 volsize = zv->zv_volsize;
1260
1261 os = zv->zv_objset;
1262 ASSERT(os != NULL);
1263
1264 bp_mapin(bp);
1265 addr = bp->b_un.b_addr;
1266 resid = bp->b_bcount;
1267
1268 if (resid > 0 && (off < 0 || off >= volsize)) {
1269 bioerror(bp, EIO);
1270 biodone(bp);
1271 return (0);
1272 }
1273
1274 is_dumpified = zv->zv_flags & ZVOL_DUMPIFIED;
1275 sync = ((!(bp->b_flags & B_ASYNC) &&
1276 !(zv->zv_flags & ZVOL_WCE)) ||
1277 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS)) &&
1278 !doread && !is_dumpified;
1279
1280 /*
1281 * There must be no buffer changes when doing a dmu_sync() because
1282 * we can't change the data whilst calculating the checksum.
1283 */
1284 rl = zfs_range_lock(&zv->zv_znode, off, resid,
1285 doread ? RL_READER : RL_WRITER);
1286
1287 while (resid != 0 && off < volsize) {
1288 size_t size = MIN(resid, zvol_maxphys);
1289 if (is_dumpified) {
1290 size = MIN(size, P2END(off, zv->zv_volblocksize) - off);
1291 error = zvol_dumpio(zv, addr, off, size,
1292 doread, B_FALSE);
1293 } else if (doread) {
1294 error = dmu_read(os, ZVOL_OBJ, off, size, addr,
1295 DMU_READ_PREFETCH);
1296 } else {
1297 dmu_tx_t *tx = dmu_tx_create(os);
1298 dmu_tx_hold_write(tx, ZVOL_OBJ, off, size);
1299 error = dmu_tx_assign(tx, TXG_WAIT);
1300 if (error) {
1301 dmu_tx_abort(tx);
1302 } else {
1303 dmu_write(os, ZVOL_OBJ, off, size, addr, tx);
1304 zvol_log_write(zv, tx, off, size, sync);
1305 dmu_tx_commit(tx);
1306 }
1307 }
1308 if (error) {
1309 /* convert checksum errors into IO errors */
1310 if (error == ECKSUM)
1311 error = SET_ERROR(EIO);
1312 break;
1313 }
1314 off += size;
1315 addr += size;
1316 resid -= size;
1317 }
1318 zfs_range_unlock(rl);
1319
1320 if ((bp->b_resid = resid) == bp->b_bcount)
1321 bioerror(bp, off > volsize ? EINVAL : error);
1322
1323 if (sync)
1324 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1325 biodone(bp);
1326
1327 return (0);
1328 }
1329
1330 /*
1331 * Set the buffer count to the zvol maximum transfer.
1332 * Using our own routine instead of the default minphys()
1333 * means that for larger writes we write bigger buffers on X86
1334 * (128K instead of 56K) and flush the disk write cache less often
1335 * (every zvol_maxphys - currently 1MB) instead of minphys (currently
1336 * 56K on X86 and 128K on sparc).
1337 */
1338 void
1339 zvol_minphys(struct buf *bp)
1340 {
1341 if (bp->b_bcount > zvol_maxphys)
1342 bp->b_bcount = zvol_maxphys;
1343 }
1344
1345 int
1346 zvol_dump(dev_t dev, caddr_t addr, daddr_t blkno, int nblocks)
1347 {
1348 minor_t minor = getminor(dev);
1349 zvol_state_t *zv;
1350 int error = 0;
1351 uint64_t size;
1352 uint64_t boff;
1353 uint64_t resid;
1354
1355 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1356 if (zv == NULL)
1357 return (SET_ERROR(ENXIO));
1358
1359 if ((zv->zv_flags & ZVOL_DUMPIFIED) == 0)
1360 return (SET_ERROR(EINVAL));
1361
1362 boff = ldbtob(blkno);
1363 resid = ldbtob(nblocks);
1364
1365 VERIFY3U(boff + resid, <=, zv->zv_volsize);
1366
1367 while (resid) {
1368 size = MIN(resid, P2END(boff, zv->zv_volblocksize) - boff);
1369 error = zvol_dumpio(zv, addr, boff, size, B_FALSE, B_TRUE);
1370 if (error)
1371 break;
1372 boff += size;
1373 addr += size;
1374 resid -= size;
1375 }
1376
1377 return (error);
1378 }
1379
1380 /*ARGSUSED*/
1381 int
1382 zvol_read(dev_t dev, uio_t *uio, cred_t *cr)
1383 {
1384 minor_t minor = getminor(dev);
1385 zvol_state_t *zv;
1386 uint64_t volsize;
1387 rl_t *rl;
1388 int error = 0;
1389
1390 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1391 if (zv == NULL)
1392 return (SET_ERROR(ENXIO));
1393
1394 volsize = zv->zv_volsize;
1395 if (uio->uio_resid > 0 &&
1396 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize))
1397 return (SET_ERROR(EIO));
1398
1399 if (zv->zv_flags & ZVOL_DUMPIFIED) {
1400 error = physio(zvol_strategy, NULL, dev, B_READ,
1401 zvol_minphys, uio);
1402 return (error);
1403 }
1404
1405 rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid,
1406 RL_READER);
1407 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) {
1408 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1);
1409
1410 /* don't read past the end */
1411 if (bytes > volsize - uio->uio_loffset)
1412 bytes = volsize - uio->uio_loffset;
1413
1414 error = dmu_read_uio(zv->zv_objset, ZVOL_OBJ, uio, bytes);
1415 if (error) {
1416 /* convert checksum errors into IO errors */
1417 if (error == ECKSUM)
1418 error = SET_ERROR(EIO);
1419 break;
1420 }
1421 }
1422 zfs_range_unlock(rl);
1423 return (error);
1424 }
1425
1426 /*ARGSUSED*/
1427 int
1428 zvol_write(dev_t dev, uio_t *uio, cred_t *cr)
1429 {
1430 minor_t minor = getminor(dev);
1431 zvol_state_t *zv;
1432 uint64_t volsize;
1433 rl_t *rl;
1434 int error = 0;
1435 boolean_t sync;
1436
1437 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1438 if (zv == NULL)
1439 return (SET_ERROR(ENXIO));
1440
1441 volsize = zv->zv_volsize;
1442 if (uio->uio_resid > 0 &&
1443 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize))
1444 return (SET_ERROR(EIO));
1445
1446 if (zv->zv_flags & ZVOL_DUMPIFIED) {
1447 error = physio(zvol_strategy, NULL, dev, B_WRITE,
1448 zvol_minphys, uio);
1449 return (error);
1450 }
1451
1452 sync = !(zv->zv_flags & ZVOL_WCE) ||
1453 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS);
1454
1455 rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid,
1456 RL_WRITER);
1457 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) {
1458 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1);
1459 uint64_t off = uio->uio_loffset;
1460 dmu_tx_t *tx = dmu_tx_create(zv->zv_objset);
1461
1462 if (bytes > volsize - off) /* don't write past the end */
1463 bytes = volsize - off;
1464
1465 dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes);
1466 error = dmu_tx_assign(tx, TXG_WAIT);
1467 if (error) {
1468 dmu_tx_abort(tx);
1469 break;
1470 }
1471 error = dmu_write_uio_dbuf(zv->zv_dbuf, uio, bytes, tx);
1472 if (error == 0)
1473 zvol_log_write(zv, tx, off, bytes, sync);
1474 dmu_tx_commit(tx);
1475
1476 if (error)
1477 break;
1478 }
1479 zfs_range_unlock(rl);
1480 if (sync)
1481 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1482 return (error);
1483 }
1484
1485 int
1486 zvol_getefi(void *arg, int flag, uint64_t vs, uint8_t bs)
1487 {
1488 struct uuid uuid = EFI_RESERVED;
1489 efi_gpe_t gpe = { 0 };
1490 uint32_t crc;
1491 dk_efi_t efi;
1492 int length;
1493 char *ptr;
1494
1495 if (ddi_copyin(arg, &efi, sizeof (dk_efi_t), flag))
1496 return (SET_ERROR(EFAULT));
1497 ptr = (char *)(uintptr_t)efi.dki_data_64;
1498 length = efi.dki_length;
1499 /*
1500 * Some clients may attempt to request a PMBR for the
1501 * zvol. Currently this interface will return EINVAL to
1502 * such requests. These requests could be supported by
1503 * adding a check for lba == 0 and consing up an appropriate
1504 * PMBR.
1505 */
1506 if (efi.dki_lba < 1 || efi.dki_lba > 2 || length <= 0)
1507 return (SET_ERROR(EINVAL));
1508
1509 gpe.efi_gpe_StartingLBA = LE_64(34ULL);
1510 gpe.efi_gpe_EndingLBA = LE_64((vs >> bs) - 1);
1511 UUID_LE_CONVERT(gpe.efi_gpe_PartitionTypeGUID, uuid);
1512
1513 if (efi.dki_lba == 1) {
1514 efi_gpt_t gpt = { 0 };
1515
1516 gpt.efi_gpt_Signature = LE_64(EFI_SIGNATURE);
1517 gpt.efi_gpt_Revision = LE_32(EFI_VERSION_CURRENT);
1518 gpt.efi_gpt_HeaderSize = LE_32(sizeof (gpt));
1519 gpt.efi_gpt_MyLBA = LE_64(1ULL);
1520 gpt.efi_gpt_FirstUsableLBA = LE_64(34ULL);
1521 gpt.efi_gpt_LastUsableLBA = LE_64((vs >> bs) - 1);
1522 gpt.efi_gpt_PartitionEntryLBA = LE_64(2ULL);
1523 gpt.efi_gpt_NumberOfPartitionEntries = LE_32(1);
1524 gpt.efi_gpt_SizeOfPartitionEntry =
1525 LE_32(sizeof (efi_gpe_t));
1526 CRC32(crc, &gpe, sizeof (gpe), -1U, crc32_table);
1527 gpt.efi_gpt_PartitionEntryArrayCRC32 = LE_32(~crc);
1528 CRC32(crc, &gpt, sizeof (gpt), -1U, crc32_table);
1529 gpt.efi_gpt_HeaderCRC32 = LE_32(~crc);
1530 if (ddi_copyout(&gpt, ptr, MIN(sizeof (gpt), length),
1531 flag))
1532 return (SET_ERROR(EFAULT));
1533 ptr += sizeof (gpt);
1534 length -= sizeof (gpt);
1535 }
1536 if (length > 0 && ddi_copyout(&gpe, ptr, MIN(sizeof (gpe),
1537 length), flag))
1538 return (SET_ERROR(EFAULT));
1539 return (0);
1540 }
1541
1542 /*
1543 * BEGIN entry points to allow external callers access to the volume.
1544 */
1545 /*
1546 * Return the volume parameters needed for access from an external caller.
1547 * These values are invariant as long as the volume is held open.
1548 */
1549 int
1550 zvol_get_volume_params(minor_t minor, uint64_t *blksize,
1551 uint64_t *max_xfer_len, void **minor_hdl, void **objset_hdl, void **zil_hdl,
1552 void **rl_hdl, void **bonus_hdl)
1553 {
1554 zvol_state_t *zv;
1555
1556 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1557 if (zv == NULL)
1558 return (SET_ERROR(ENXIO));
1559 if (zv->zv_flags & ZVOL_DUMPIFIED)
1560 return (SET_ERROR(ENXIO));
1561
1562 ASSERT(blksize && max_xfer_len && minor_hdl &&
1563 objset_hdl && zil_hdl && rl_hdl && bonus_hdl);
1564
1565 *blksize = zv->zv_volblocksize;
1566 *max_xfer_len = (uint64_t)zvol_maxphys;
1567 *minor_hdl = zv;
1568 *objset_hdl = zv->zv_objset;
1569 *zil_hdl = zv->zv_zilog;
1570 *rl_hdl = &zv->zv_znode;
1571 *bonus_hdl = zv->zv_dbuf;
1572 return (0);
1573 }
1574
1575 /*
1576 * Return the current volume size to an external caller.
1577 * The size can change while the volume is open.
1578 */
1579 uint64_t
1580 zvol_get_volume_size(void *minor_hdl)
1581 {
1582 zvol_state_t *zv = minor_hdl;
1583
1584 return (zv->zv_volsize);
1585 }
1586
1587 /*
1588 * Return the current WCE setting to an external caller.
1589 * The WCE setting can change while the volume is open.
1590 */
1591 int
1592 zvol_get_volume_wce(void *minor_hdl)
1593 {
1594 zvol_state_t *zv = minor_hdl;
1595
1596 return ((zv->zv_flags & ZVOL_WCE) ? 1 : 0);
1597 }
1598
1599 /*
1600 * Entry point for external callers to zvol_log_write
1601 */
1602 void
1603 zvol_log_write_minor(void *minor_hdl, dmu_tx_t *tx, offset_t off, ssize_t resid,
1604 boolean_t sync)
1605 {
1606 zvol_state_t *zv = minor_hdl;
1607
1608 zvol_log_write(zv, tx, off, resid, sync);
1609 }
1610 /*
1611 * END entry points to allow external callers access to the volume.
1612 */
1613
1614 /*
1615 * Log a DKIOCFREE/free-long-range to the ZIL with TX_TRUNCATE.
1616 */
1617 static void
1618 zvol_log_truncate(zvol_state_t *zv, dmu_tx_t *tx, uint64_t off, uint64_t len,
1619 boolean_t sync)
1620 {
1621 itx_t *itx;
1622 lr_truncate_t *lr;
1623 zilog_t *zilog = zv->zv_zilog;
1624
1625 if (zil_replaying(zilog, tx))
1626 return;
1627
1628 itx = zil_itx_create(TX_TRUNCATE, sizeof (*lr));
1629 lr = (lr_truncate_t *)&itx->itx_lr;
1630 lr->lr_foid = ZVOL_OBJ;
1631 lr->lr_offset = off;
1632 lr->lr_length = len;
1633
1634 itx->itx_sync = sync;
1635 zil_itx_assign(zilog, itx, tx);
1636 }
1637
1638 /*
1639 * Dirtbag ioctls to support mkfs(1M) for UFS filesystems. See dkio(7I).
1640 * Also a dirtbag dkio ioctl for unmap/free-block functionality.
1641 */
1642 /*ARGSUSED*/
1643 int
1644 zvol_ioctl(dev_t dev, int cmd, intptr_t arg, int flag, cred_t *cr, int *rvalp)
1645 {
1646 zvol_state_t *zv;
1647 struct dk_callback *dkc;
1648 int error = 0;
1649 rl_t *rl;
1650
1651 mutex_enter(&zfsdev_state_lock);
1652
1653 zv = zfsdev_get_soft_state(getminor(dev), ZSST_ZVOL);
1654
1655 if (zv == NULL) {
1656 mutex_exit(&zfsdev_state_lock);
1657 return (SET_ERROR(ENXIO));
1658 }
1659 ASSERT(zv->zv_total_opens > 0);
1660
1661 switch (cmd) {
1662
1663 case DKIOCINFO:
1664 {
1665 struct dk_cinfo dki;
1666
1667 bzero(&dki, sizeof (dki));
1668 (void) strcpy(dki.dki_cname, "zvol");
1669 (void) strcpy(dki.dki_dname, "zvol");
1670 dki.dki_ctype = DKC_UNKNOWN;
1671 dki.dki_unit = getminor(dev);
1672 dki.dki_maxtransfer =
1673 1 << (SPA_OLD_MAXBLOCKSHIFT - zv->zv_min_bs);
1674 mutex_exit(&zfsdev_state_lock);
1675 if (ddi_copyout(&dki, (void *)arg, sizeof (dki), flag))
1676 error = SET_ERROR(EFAULT);
1677 return (error);
1678 }
1679
1680 case DKIOCGMEDIAINFO:
1681 {
1682 struct dk_minfo dkm;
1683
1684 bzero(&dkm, sizeof (dkm));
1685 dkm.dki_lbsize = 1U << zv->zv_min_bs;
1686 dkm.dki_capacity = zv->zv_volsize >> zv->zv_min_bs;
1687 dkm.dki_media_type = DK_UNKNOWN;
1688 mutex_exit(&zfsdev_state_lock);
1689 if (ddi_copyout(&dkm, (void *)arg, sizeof (dkm), flag))
1690 error = SET_ERROR(EFAULT);
1691 return (error);
1692 }
1693
1694 case DKIOCGMEDIAINFOEXT:
1695 {
1696 struct dk_minfo_ext dkmext;
1697
1698 bzero(&dkmext, sizeof (dkmext));
1699 dkmext.dki_lbsize = 1U << zv->zv_min_bs;
1700 dkmext.dki_pbsize = zv->zv_volblocksize;
1701 dkmext.dki_capacity = zv->zv_volsize >> zv->zv_min_bs;
1702 dkmext.dki_media_type = DK_UNKNOWN;
1703 mutex_exit(&zfsdev_state_lock);
1704 if (ddi_copyout(&dkmext, (void *)arg, sizeof (dkmext), flag))
1705 error = SET_ERROR(EFAULT);
1706 return (error);
1707 }
1708
1709 case DKIOCGETEFI:
1710 {
1711 uint64_t vs = zv->zv_volsize;
1712 uint8_t bs = zv->zv_min_bs;
1713
1714 mutex_exit(&zfsdev_state_lock);
1715 error = zvol_getefi((void *)arg, flag, vs, bs);
1716 return (error);
1717 }
1718
1719 case DKIOCFLUSHWRITECACHE:
1720 dkc = (struct dk_callback *)arg;
1721 mutex_exit(&zfsdev_state_lock);
1722 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1723 if ((flag & FKIOCTL) && dkc != NULL && dkc->dkc_callback) {
1724 (*dkc->dkc_callback)(dkc->dkc_cookie, error);
1725 error = 0;
1726 }
1727 return (error);
1728
1729 case DKIOCGETWCE:
1730 {
1731 int wce = (zv->zv_flags & ZVOL_WCE) ? 1 : 0;
1732 if (ddi_copyout(&wce, (void *)arg, sizeof (int),
1733 flag))
1734 error = SET_ERROR(EFAULT);
1735 break;
1736 }
1737 case DKIOCSETWCE:
1738 {
1739 int wce;
1740 if (ddi_copyin((void *)arg, &wce, sizeof (int),
1741 flag)) {
1742 error = SET_ERROR(EFAULT);
1743 break;
1744 }
1745 if (wce) {
1746 zv->zv_flags |= ZVOL_WCE;
1747 mutex_exit(&zfsdev_state_lock);
1748 } else {
1749 zv->zv_flags &= ~ZVOL_WCE;
1750 mutex_exit(&zfsdev_state_lock);
1751 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1752 }
1753 return (0);
1754 }
1755
1756 case DKIOCGGEOM:
1757 case DKIOCGVTOC:
1758 /*
1759 * commands using these (like prtvtoc) expect ENOTSUP
1760 * since we're emulating an EFI label
1761 */
1762 error = SET_ERROR(ENOTSUP);
1763 break;
1764
1765 case DKIOCDUMPINIT:
1766 rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize,
1767 RL_WRITER);
1768 error = zvol_dumpify(zv);
1769 zfs_range_unlock(rl);
1770 break;
1771
1772 case DKIOCDUMPFINI:
1773 if (!(zv->zv_flags & ZVOL_DUMPIFIED))
1774 break;
1775 rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize,
1776 RL_WRITER);
1777 error = zvol_dump_fini(zv);
1778 zfs_range_unlock(rl);
1779 break;
1780
1781 case DKIOCFREE:
1782 {
1783 dkioc_free_t df;
1784 dmu_tx_t *tx;
1785
1786 if (!zvol_unmap_enabled)
1787 break;
1788
1789 if (ddi_copyin((void *)arg, &df, sizeof (df), flag)) {
1790 error = SET_ERROR(EFAULT);
1791 break;
1792 }
1793
1794 /*
1795 * Apply Postel's Law to length-checking. If they overshoot,
1796 * just blank out until the end, if there's a need to blank
1797 * out anything.
1798 */
1799 if (df.df_start >= zv->zv_volsize)
1800 break; /* No need to do anything... */
1801
1802 mutex_exit(&zfsdev_state_lock);
1803
1804 rl = zfs_range_lock(&zv->zv_znode, df.df_start, df.df_length,
1805 RL_WRITER);
1806 tx = dmu_tx_create(zv->zv_objset);
1807 dmu_tx_mark_netfree(tx);
1808 error = dmu_tx_assign(tx, TXG_WAIT);
1809 if (error != 0) {
1810 dmu_tx_abort(tx);
1811 } else {
1812 zvol_log_truncate(zv, tx, df.df_start,
1813 df.df_length, B_TRUE);
1814 dmu_tx_commit(tx);
1815 error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ,
1816 df.df_start, df.df_length);
1817 }
1818
1819 zfs_range_unlock(rl);
1820
1821 /*
1822 * If the write-cache is disabled, 'sync' property
1823 * is set to 'always', or if the caller is asking for
1824 * a synchronous free, commit this operation to the zil.
1825 * This will sync any previous uncommitted writes to the
1826 * zvol object.
1827 * Can be overridden by the zvol_unmap_sync_enabled tunable.
1828 */
1829 if ((error == 0) && zvol_unmap_sync_enabled &&
1830 (!(zv->zv_flags & ZVOL_WCE) ||
1831 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS) ||
1832 (df.df_flags & DF_WAIT_SYNC))) {
1833 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1834 }
1835
1836 return (error);
1837 }
1838
1839 default:
1840 error = SET_ERROR(ENOTTY);
1841 break;
1842
1843 }
1844 mutex_exit(&zfsdev_state_lock);
1845 return (error);
1846 }
1847
1848 int
1849 zvol_busy(void)
1850 {
1851 return (zvol_minors != 0);
1852 }
1853
1854 void
1855 zvol_init(void)
1856 {
1857 VERIFY(ddi_soft_state_init(&zfsdev_state, sizeof (zfs_soft_state_t),
1858 1) == 0);
1859 mutex_init(&zfsdev_state_lock, NULL, MUTEX_DEFAULT, NULL);
1860 }
1861
1862 void
1863 zvol_fini(void)
1864 {
1865 mutex_destroy(&zfsdev_state_lock);
1866 ddi_soft_state_fini(&zfsdev_state);
1867 }
1868
1869 /*ARGSUSED*/
1870 static int
1871 zfs_mvdev_dump_feature_check(void *arg, dmu_tx_t *tx)
1872 {
1873 spa_t *spa = dmu_tx_pool(tx)->dp_spa;
1874
1875 if (spa_feature_is_active(spa, SPA_FEATURE_MULTI_VDEV_CRASH_DUMP))
1876 return (1);
1877 return (0);
1878 }
1879
1880 /*ARGSUSED*/
1881 static void
1882 zfs_mvdev_dump_activate_feature_sync(void *arg, dmu_tx_t *tx)
1883 {
1884 spa_t *spa = dmu_tx_pool(tx)->dp_spa;
1885
1886 spa_feature_incr(spa, SPA_FEATURE_MULTI_VDEV_CRASH_DUMP, tx);
1887 }
1888
1889 static int
1890 zvol_dump_init(zvol_state_t *zv, boolean_t resize)
1891 {
1892 dmu_tx_t *tx;
1893 int error;
1894 objset_t *os = zv->zv_objset;
1895 spa_t *spa = dmu_objset_spa(os);
1896 vdev_t *vd = spa->spa_root_vdev;
1897 nvlist_t *nv = NULL;
1898 uint64_t version = spa_version(spa);
1899 uint64_t checksum, compress, refresrv, vbs, dedup;
1900
1901 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
1902 ASSERT(vd->vdev_ops == &vdev_root_ops);
1903
1904 error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, 0,
1905 DMU_OBJECT_END);
1906 if (error != 0)
1907 return (error);
1908 /* wait for dmu_free_long_range to actually free the blocks */
1909 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
1910
1911 /*
1912 * If the pool on which the dump device is being initialized has more
1913 * than one child vdev, check that the MULTI_VDEV_CRASH_DUMP feature is
1914 * enabled. If so, bump that feature's counter to indicate that the
1915 * feature is active. We also check the vdev type to handle the
1916 * following case:
1917 * # zpool create test raidz disk1 disk2 disk3
1918 * Now have spa_root_vdev->vdev_children == 1 (the raidz vdev),
1919 * the raidz vdev itself has 3 children.
1920 */
1921 if (vd->vdev_children > 1 || vd->vdev_ops == &vdev_raidz_ops) {
1922 if (!spa_feature_is_enabled(spa,
1923 SPA_FEATURE_MULTI_VDEV_CRASH_DUMP))
1924 return (SET_ERROR(ENOTSUP));
1925 (void) dsl_sync_task(spa_name(spa),
1926 zfs_mvdev_dump_feature_check,
1927 zfs_mvdev_dump_activate_feature_sync, NULL,
1928 2, ZFS_SPACE_CHECK_RESERVED);
1929 }
1930
1931 if (!resize) {
1932 error = dsl_prop_get_integer(zv->zv_name,
1933 zfs_prop_to_name(ZFS_PROP_COMPRESSION), &compress, NULL);
1934 if (error == 0) {
1935 error = dsl_prop_get_integer(zv->zv_name,
1936 zfs_prop_to_name(ZFS_PROP_CHECKSUM), &checksum,
1937 NULL);
1938 }
1939 if (error == 0) {
1940 error = dsl_prop_get_integer(zv->zv_name,
1941 zfs_prop_to_name(ZFS_PROP_REFRESERVATION),
1942 &refresrv, NULL);
1943 }
1944 if (error == 0) {
1945 error = dsl_prop_get_integer(zv->zv_name,
1946 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &vbs,
1947 NULL);
1948 }
1949 if (version >= SPA_VERSION_DEDUP && error == 0) {
1950 error = dsl_prop_get_integer(zv->zv_name,
1951 zfs_prop_to_name(ZFS_PROP_DEDUP), &dedup, NULL);
1952 }
1953 }
1954 if (error != 0)
1955 return (error);
1956
1957 tx = dmu_tx_create(os);
1958 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
1959 dmu_tx_hold_bonus(tx, ZVOL_OBJ);
1960 error = dmu_tx_assign(tx, TXG_WAIT);
1961 if (error != 0) {
1962 dmu_tx_abort(tx);
1963 return (error);
1964 }
1965
1966 /*
1967 * If we are resizing the dump device then we only need to
1968 * update the refreservation to match the newly updated
1969 * zvolsize. Otherwise, we save off the original state of the
1970 * zvol so that we can restore them if the zvol is ever undumpified.
1971 */
1972 if (resize) {
1973 error = zap_update(os, ZVOL_ZAP_OBJ,
1974 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1,
1975 &zv->zv_volsize, tx);
1976 } else {
1977 error = zap_update(os, ZVOL_ZAP_OBJ,
1978 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1,
1979 &compress, tx);
1980 if (error == 0) {
1981 error = zap_update(os, ZVOL_ZAP_OBJ,
1982 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1,
1983 &checksum, tx);
1984 }
1985 if (error == 0) {
1986 error = zap_update(os, ZVOL_ZAP_OBJ,
1987 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1,
1988 &refresrv, tx);
1989 }
1990 if (error == 0) {
1991 error = zap_update(os, ZVOL_ZAP_OBJ,
1992 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1,
1993 &vbs, tx);
1994 }
1995 if (error == 0) {
1996 error = dmu_object_set_blocksize(
1997 os, ZVOL_OBJ, SPA_OLD_MAXBLOCKSIZE, 0, tx);
1998 }
1999 if (version >= SPA_VERSION_DEDUP && error == 0) {
2000 error = zap_update(os, ZVOL_ZAP_OBJ,
2001 zfs_prop_to_name(ZFS_PROP_DEDUP), 8, 1,
2002 &dedup, tx);
2003 }
2004 if (error == 0)
2005 zv->zv_volblocksize = SPA_OLD_MAXBLOCKSIZE;
2006 }
2007 dmu_tx_commit(tx);
2008
2009 /*
2010 * We only need update the zvol's property if we are initializing
2011 * the dump area for the first time.
2012 */
2013 if (error == 0 && !resize) {
2014 /*
2015 * If MULTI_VDEV_CRASH_DUMP is active, use the NOPARITY checksum
2016 * function. Otherwise, use the old default -- OFF.
2017 */
2018 checksum = spa_feature_is_active(spa,
2019 SPA_FEATURE_MULTI_VDEV_CRASH_DUMP) ? ZIO_CHECKSUM_NOPARITY :
2020 ZIO_CHECKSUM_OFF;
2021
2022 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2023 VERIFY(nvlist_add_uint64(nv,
2024 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 0) == 0);
2025 VERIFY(nvlist_add_uint64(nv,
2026 zfs_prop_to_name(ZFS_PROP_COMPRESSION),
2027 ZIO_COMPRESS_OFF) == 0);
2028 VERIFY(nvlist_add_uint64(nv,
2029 zfs_prop_to_name(ZFS_PROP_CHECKSUM),
2030 checksum) == 0);
2031 if (version >= SPA_VERSION_DEDUP) {
2032 VERIFY(nvlist_add_uint64(nv,
2033 zfs_prop_to_name(ZFS_PROP_DEDUP),
2034 ZIO_CHECKSUM_OFF) == 0);
2035 }
2036
2037 error = zfs_set_prop_nvlist(zv->zv_name, ZPROP_SRC_LOCAL,
2038 nv, NULL);
2039 nvlist_free(nv);
2040 }
2041
2042 /* Allocate the space for the dump */
2043 if (error == 0)
2044 error = zvol_prealloc(zv);
2045 return (error);
2046 }
2047
2048 static int
2049 zvol_dumpify(zvol_state_t *zv)
2050 {
2051 int error = 0;
2052 uint64_t dumpsize = 0;
2053 dmu_tx_t *tx;
2054 objset_t *os = zv->zv_objset;
2055
2056 if (zv->zv_flags & ZVOL_RDONLY)
2057 return (SET_ERROR(EROFS));
2058
2059 if (zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE,
2060 8, 1, &dumpsize) != 0 || dumpsize != zv->zv_volsize) {
2061 boolean_t resize = (dumpsize > 0);
2062
2063 if ((error = zvol_dump_init(zv, resize)) != 0) {
2064 (void) zvol_dump_fini(zv);
2065 return (error);
2066 }
2067 }
2068
2069 /*
2070 * Build up our lba mapping.
2071 */
2072 error = zvol_get_lbas(zv);
2073 if (error) {
2074 (void) zvol_dump_fini(zv);
2075 return (error);
2076 }
2077
2078 tx = dmu_tx_create(os);
2079 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
2080 error = dmu_tx_assign(tx, TXG_WAIT);
2081 if (error) {
2082 dmu_tx_abort(tx);
2083 (void) zvol_dump_fini(zv);
2084 return (error);
2085 }
2086
2087 zv->zv_flags |= ZVOL_DUMPIFIED;
2088 error = zap_update(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, 8, 1,
2089 &zv->zv_volsize, tx);
2090 dmu_tx_commit(tx);
2091
2092 if (error) {
2093 (void) zvol_dump_fini(zv);
2094 return (error);
2095 }
2096
2097 txg_wait_synced(dmu_objset_pool(os), 0);
2098 return (0);
2099 }
2100
2101 static int
2102 zvol_dump_fini(zvol_state_t *zv)
2103 {
2104 dmu_tx_t *tx;
2105 objset_t *os = zv->zv_objset;
2106 nvlist_t *nv;
2107 int error = 0;
2108 uint64_t checksum, compress, refresrv, vbs, dedup;
2109 uint64_t version = spa_version(dmu_objset_spa(zv->zv_objset));
2110
2111 /*
2112 * Attempt to restore the zvol back to its pre-dumpified state.
2113 * This is a best-effort attempt as it's possible that not all
2114 * of these properties were initialized during the dumpify process
2115 * (i.e. error during zvol_dump_init).
2116 */
2117
2118 tx = dmu_tx_create(os);
2119 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
2120 error = dmu_tx_assign(tx, TXG_WAIT);
2121 if (error) {
2122 dmu_tx_abort(tx);
2123 return (error);
2124 }
2125 (void) zap_remove(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, tx);
2126 dmu_tx_commit(tx);
2127
2128 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2129 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1, &checksum);
2130 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2131 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1, &compress);
2132 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2133 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, &refresrv);
2134 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2135 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1, &vbs);
2136
2137 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2138 (void) nvlist_add_uint64(nv,
2139 zfs_prop_to_name(ZFS_PROP_CHECKSUM), checksum);
2140 (void) nvlist_add_uint64(nv,
2141 zfs_prop_to_name(ZFS_PROP_COMPRESSION), compress);
2142 (void) nvlist_add_uint64(nv,
2143 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), refresrv);
2144 if (version >= SPA_VERSION_DEDUP &&
2145 zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2146 zfs_prop_to_name(ZFS_PROP_DEDUP), 8, 1, &dedup) == 0) {
2147 (void) nvlist_add_uint64(nv,
2148 zfs_prop_to_name(ZFS_PROP_DEDUP), dedup);
2149 }
2150 (void) zfs_set_prop_nvlist(zv->zv_name, ZPROP_SRC_LOCAL,
2151 nv, NULL);
2152 nvlist_free(nv);
2153
2154 zvol_free_extents(zv);
2155 zv->zv_flags &= ~ZVOL_DUMPIFIED;
2156 (void) dmu_free_long_range(os, ZVOL_OBJ, 0, DMU_OBJECT_END);
2157 /* wait for dmu_free_long_range to actually free the blocks */
2158 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
2159 tx = dmu_tx_create(os);
2160 dmu_tx_hold_bonus(tx, ZVOL_OBJ);
2161 error = dmu_tx_assign(tx, TXG_WAIT);
2162 if (error) {
2163 dmu_tx_abort(tx);
2164 return (error);
2165 }
2166 if (dmu_object_set_blocksize(os, ZVOL_OBJ, vbs, 0, tx) == 0)
2167 zv->zv_volblocksize = vbs;
2168 dmu_tx_commit(tx);
2169
2170 return (0);
2171 }