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 2017 Nexenta Systems, Inc. All rights reserved.
27 * Copyright (c) 2012, 2017 by Delphix. All rights reserved.
28 * Copyright (c) 2014 Integros [integros.com]
29 * Copyright (c) 2019, Joyent, Inc.
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 #include <sys/ht.h>
93 #include <sys/dkioc_free_util.h>
94 #include <sys/zfs_rlock.h>
95
96 #include "zfs_namecheck.h"
97
98 void *zfsdev_state;
99 static char *zvol_tag = "zvol_tag";
100
101 #define ZVOL_DUMPSIZE "dumpsize"
102
103 /*
104 * This lock protects the zfsdev_state structure from being modified
105 * while it's being used, e.g. an open that comes in before a create
106 * finishes. It also protects temporary opens of the dataset so that,
107 * e.g., an open doesn't get a spurious EBUSY.
108 */
109 kmutex_t zfsdev_state_lock;
110 static uint32_t zvol_minors;
111
112 typedef struct zvol_extent {
113 list_node_t ze_node;
114 dva_t ze_dva; /* dva associated with this extent */
115 uint64_t ze_nblks; /* number of blocks in extent */
116 } zvol_extent_t;
117
118 /*
119 * The in-core state of each volume.
120 */
121 typedef struct zvol_state {
122 char zv_name[MAXPATHLEN]; /* pool/dd name */
123 uint64_t zv_volsize; /* amount of space we advertise */
124 uint64_t zv_volblocksize; /* volume block size */
125 minor_t zv_minor; /* minor number */
126 uint8_t zv_min_bs; /* minimum addressable block shift */
127 uint8_t zv_flags; /* readonly, dumpified, etc. */
128 objset_t *zv_objset; /* objset handle */
129 uint32_t zv_open_count[OTYPCNT]; /* open counts */
130 uint32_t zv_total_opens; /* total open count */
131 zilog_t *zv_zilog; /* ZIL handle */
132 list_t zv_extents; /* List of extents for dump */
133 rangelock_t zv_rangelock;
134 dnode_t *zv_dn; /* dnode hold */
135 } zvol_state_t;
136
137 /*
138 * zvol specific flags
139 */
140 #define ZVOL_RDONLY 0x1
141 #define ZVOL_DUMPIFIED 0x2
142 #define ZVOL_EXCL 0x4
143 #define ZVOL_WCE 0x8
144
145 /*
146 * zvol maximum transfer in one DMU tx.
147 */
148 int zvol_maxphys = DMU_MAX_ACCESS/2;
149
150 /*
151 * Toggle unmap functionality.
152 */
153 boolean_t zvol_unmap_enabled = B_TRUE;
154
155 /*
156 * If true, unmaps requested as synchronous are executed synchronously,
157 * otherwise all unmaps are asynchronous.
158 */
159 boolean_t zvol_unmap_sync_enabled = B_FALSE;
160
161 extern int zfs_set_prop_nvlist(const char *, zprop_source_t,
162 nvlist_t *, nvlist_t *);
163 static int zvol_remove_zv(zvol_state_t *);
164 static int zvol_get_data(void *arg, lr_write_t *lr, char *buf,
165 struct lwb *lwb, zio_t *zio);
166 static int zvol_dumpify(zvol_state_t *zv);
167 static int zvol_dump_fini(zvol_state_t *zv);
168 static int zvol_dump_init(zvol_state_t *zv, boolean_t resize);
169
170 static void
171 zvol_size_changed(zvol_state_t *zv, uint64_t volsize)
172 {
173 dev_t dev = makedevice(ddi_driver_major(zfs_dip), zv->zv_minor);
174
175 zv->zv_volsize = volsize;
176 VERIFY(ddi_prop_update_int64(dev, zfs_dip,
177 "Size", volsize) == DDI_SUCCESS);
178 VERIFY(ddi_prop_update_int64(dev, zfs_dip,
179 "Nblocks", lbtodb(volsize)) == DDI_SUCCESS);
180
181 /* Notify specfs to invalidate the cached size */
182 spec_size_invalidate(dev, VBLK);
183 spec_size_invalidate(dev, VCHR);
184 }
185
186 int
187 zvol_check_volsize(uint64_t volsize, uint64_t blocksize)
188 {
189 if (volsize == 0)
190 return (SET_ERROR(EINVAL));
191
192 if (volsize % blocksize != 0)
193 return (SET_ERROR(EINVAL));
194
195 #ifdef _ILP32
196 if (volsize - 1 > SPEC_MAXOFFSET_T)
197 return (SET_ERROR(EOVERFLOW));
198 #endif
199 return (0);
200 }
201
202 int
203 zvol_check_volblocksize(uint64_t volblocksize)
204 {
205 if (volblocksize < SPA_MINBLOCKSIZE ||
206 volblocksize > SPA_OLD_MAXBLOCKSIZE ||
207 !ISP2(volblocksize))
208 return (SET_ERROR(EDOM));
209
210 return (0);
211 }
212
213 int
214 zvol_get_stats(objset_t *os, nvlist_t *nv)
215 {
216 int error;
217 dmu_object_info_t doi;
218 uint64_t val;
219
220 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &val);
221 if (error)
222 return (error);
223
224 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLSIZE, val);
225
226 error = dmu_object_info(os, ZVOL_OBJ, &doi);
227
228 if (error == 0) {
229 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLBLOCKSIZE,
230 doi.doi_data_block_size);
231 }
232
233 return (error);
234 }
235
236 static zvol_state_t *
237 zvol_minor_lookup(const char *name)
238 {
239 minor_t minor;
240 zvol_state_t *zv;
241
242 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
243
244 for (minor = 1; minor <= ZFSDEV_MAX_MINOR; minor++) {
245 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
246 if (zv == NULL)
247 continue;
248 if (strcmp(zv->zv_name, name) == 0)
249 return (zv);
250 }
251
252 return (NULL);
253 }
254
255 /* extent mapping arg */
256 struct maparg {
257 zvol_state_t *ma_zv;
258 uint64_t ma_blks;
259 };
260
261 /*ARGSUSED*/
262 static int
263 zvol_map_block(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
264 const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
265 {
266 struct maparg *ma = arg;
267 zvol_extent_t *ze;
268 int bs = ma->ma_zv->zv_volblocksize;
269
270 if (bp == NULL || BP_IS_HOLE(bp) ||
271 zb->zb_object != ZVOL_OBJ || zb->zb_level != 0)
272 return (0);
273
274 VERIFY(!BP_IS_EMBEDDED(bp));
275
276 VERIFY3U(ma->ma_blks, ==, zb->zb_blkid);
277 ma->ma_blks++;
278
279 /* Abort immediately if we have encountered gang blocks */
280 if (BP_IS_GANG(bp))
281 return (SET_ERROR(EFRAGS));
282
283 /*
284 * See if the block is at the end of the previous extent.
285 */
286 ze = list_tail(&ma->ma_zv->zv_extents);
287 if (ze &&
288 DVA_GET_VDEV(BP_IDENTITY(bp)) == DVA_GET_VDEV(&ze->ze_dva) &&
289 DVA_GET_OFFSET(BP_IDENTITY(bp)) ==
290 DVA_GET_OFFSET(&ze->ze_dva) + ze->ze_nblks * bs) {
291 ze->ze_nblks++;
292 return (0);
293 }
294
295 dprintf_bp(bp, "%s", "next blkptr:");
296
297 /* start a new extent */
298 ze = kmem_zalloc(sizeof (zvol_extent_t), KM_SLEEP);
299 ze->ze_dva = bp->blk_dva[0]; /* structure assignment */
300 ze->ze_nblks = 1;
301 list_insert_tail(&ma->ma_zv->zv_extents, ze);
302 return (0);
303 }
304
305 static void
306 zvol_free_extents(zvol_state_t *zv)
307 {
308 zvol_extent_t *ze;
309
310 while (ze = list_head(&zv->zv_extents)) {
311 list_remove(&zv->zv_extents, ze);
312 kmem_free(ze, sizeof (zvol_extent_t));
313 }
314 }
315
316 static int
317 zvol_get_lbas(zvol_state_t *zv)
318 {
319 objset_t *os = zv->zv_objset;
320 struct maparg ma;
321 int err;
322
323 ma.ma_zv = zv;
324 ma.ma_blks = 0;
325 zvol_free_extents(zv);
326
327 /* commit any in-flight changes before traversing the dataset */
328 txg_wait_synced(dmu_objset_pool(os), 0);
329 err = traverse_dataset(dmu_objset_ds(os), 0,
330 TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA, zvol_map_block, &ma);
331 if (err || ma.ma_blks != (zv->zv_volsize / zv->zv_volblocksize)) {
332 zvol_free_extents(zv);
333 return (err ? err : EIO);
334 }
335
336 return (0);
337 }
338
339 /* ARGSUSED */
340 void
341 zvol_create_cb(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx)
342 {
343 zfs_creat_t *zct = arg;
344 nvlist_t *nvprops = zct->zct_props;
345 int error;
346 uint64_t volblocksize, volsize;
347
348 VERIFY(nvlist_lookup_uint64(nvprops,
349 zfs_prop_to_name(ZFS_PROP_VOLSIZE), &volsize) == 0);
350 if (nvlist_lookup_uint64(nvprops,
351 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &volblocksize) != 0)
352 volblocksize = zfs_prop_default_numeric(ZFS_PROP_VOLBLOCKSIZE);
353
354 /*
355 * These properties must be removed from the list so the generic
356 * property setting step won't apply to them.
357 */
358 VERIFY(nvlist_remove_all(nvprops,
359 zfs_prop_to_name(ZFS_PROP_VOLSIZE)) == 0);
360 (void) nvlist_remove_all(nvprops,
361 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE));
362
363 error = dmu_object_claim(os, ZVOL_OBJ, DMU_OT_ZVOL, volblocksize,
364 DMU_OT_NONE, 0, tx);
365 ASSERT(error == 0);
366
367 error = zap_create_claim(os, ZVOL_ZAP_OBJ, DMU_OT_ZVOL_PROP,
368 DMU_OT_NONE, 0, tx);
369 ASSERT(error == 0);
370
371 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize, tx);
372 ASSERT(error == 0);
373 }
374
375 /*
376 * Replay a TX_TRUNCATE ZIL transaction if asked. TX_TRUNCATE is how we
377 * implement DKIOCFREE/free-long-range.
378 */
379 static int
380 zvol_replay_truncate(void *arg1, void *arg2, boolean_t byteswap)
381 {
382 zvol_state_t *zv = arg1;
383 lr_truncate_t *lr = arg2;
384 uint64_t offset, length;
385
386 if (byteswap)
387 byteswap_uint64_array(lr, sizeof (*lr));
388
389 offset = lr->lr_offset;
390 length = lr->lr_length;
391
392 return (dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, offset, length));
393 }
394
395 /*
396 * Replay a TX_WRITE ZIL transaction that didn't get committed
397 * after a system failure
398 */
399 static int
400 zvol_replay_write(void *arg1, void *arg2, boolean_t byteswap)
401 {
402 zvol_state_t *zv = arg1;
403 lr_write_t *lr = arg2;
404 objset_t *os = zv->zv_objset;
405 char *data = (char *)(lr + 1); /* data follows lr_write_t */
406 uint64_t offset, length;
407 dmu_tx_t *tx;
408 int error;
409
410 if (byteswap)
411 byteswap_uint64_array(lr, sizeof (*lr));
412
413 offset = lr->lr_offset;
414 length = lr->lr_length;
415
416 /* If it's a dmu_sync() block, write the whole block */
417 if (lr->lr_common.lrc_reclen == sizeof (lr_write_t)) {
418 uint64_t blocksize = BP_GET_LSIZE(&lr->lr_blkptr);
419 if (length < blocksize) {
420 offset -= offset % blocksize;
421 length = blocksize;
422 }
423 }
424
425 tx = dmu_tx_create(os);
426 dmu_tx_hold_write(tx, ZVOL_OBJ, offset, length);
427 error = dmu_tx_assign(tx, TXG_WAIT);
428 if (error) {
429 dmu_tx_abort(tx);
430 } else {
431 dmu_write(os, ZVOL_OBJ, offset, length, data, tx);
432 dmu_tx_commit(tx);
433 }
434
435 return (error);
436 }
437
438 /* ARGSUSED */
439 static int
440 zvol_replay_err(void *arg1, void *arg2, boolean_t byteswap)
441 {
442 return (SET_ERROR(ENOTSUP));
443 }
444
445 /*
446 * Callback vectors for replaying records.
447 * Only TX_WRITE and TX_TRUNCATE are needed for zvol.
448 */
449 zil_replay_func_t *zvol_replay_vector[TX_MAX_TYPE] = {
450 zvol_replay_err, /* 0 no such transaction type */
451 zvol_replay_err, /* TX_CREATE */
452 zvol_replay_err, /* TX_MKDIR */
453 zvol_replay_err, /* TX_MKXATTR */
454 zvol_replay_err, /* TX_SYMLINK */
455 zvol_replay_err, /* TX_REMOVE */
456 zvol_replay_err, /* TX_RMDIR */
457 zvol_replay_err, /* TX_LINK */
458 zvol_replay_err, /* TX_RENAME */
459 zvol_replay_write, /* TX_WRITE */
460 zvol_replay_truncate, /* TX_TRUNCATE */
461 zvol_replay_err, /* TX_SETATTR */
462 zvol_replay_err, /* TX_ACL */
463 zvol_replay_err, /* TX_CREATE_ACL */
464 zvol_replay_err, /* TX_CREATE_ATTR */
465 zvol_replay_err, /* TX_CREATE_ACL_ATTR */
466 zvol_replay_err, /* TX_MKDIR_ACL */
467 zvol_replay_err, /* TX_MKDIR_ATTR */
468 zvol_replay_err, /* TX_MKDIR_ACL_ATTR */
469 zvol_replay_err, /* TX_WRITE2 */
470 };
471
472 int
473 zvol_name2minor(const char *name, minor_t *minor)
474 {
475 zvol_state_t *zv;
476
477 mutex_enter(&zfsdev_state_lock);
478 zv = zvol_minor_lookup(name);
479 if (minor && zv)
480 *minor = zv->zv_minor;
481 mutex_exit(&zfsdev_state_lock);
482 return (zv ? 0 : -1);
483 }
484
485 /*
486 * Create a minor node (plus a whole lot more) for the specified volume.
487 */
488 int
489 zvol_create_minor(const char *name)
490 {
491 zfs_soft_state_t *zs;
492 zvol_state_t *zv;
493 objset_t *os;
494 dmu_object_info_t doi;
495 minor_t minor = 0;
496 char chrbuf[30], blkbuf[30];
497 int error;
498
499 mutex_enter(&zfsdev_state_lock);
500
501 if (zvol_minor_lookup(name) != NULL) {
502 mutex_exit(&zfsdev_state_lock);
503 return (SET_ERROR(EEXIST));
504 }
505
506 /* lie and say we're read-only */
507 error = dmu_objset_own(name, DMU_OST_ZVOL, B_TRUE, FTAG, &os);
508
509 if (error) {
510 mutex_exit(&zfsdev_state_lock);
511 return (error);
512 }
513
514 if ((minor = zfsdev_minor_alloc()) == 0) {
515 dmu_objset_disown(os, FTAG);
516 mutex_exit(&zfsdev_state_lock);
517 return (SET_ERROR(ENXIO));
518 }
519
520 if (ddi_soft_state_zalloc(zfsdev_state, minor) != DDI_SUCCESS) {
521 dmu_objset_disown(os, FTAG);
522 mutex_exit(&zfsdev_state_lock);
523 return (SET_ERROR(EAGAIN));
524 }
525 (void) ddi_prop_update_string(minor, zfs_dip, ZVOL_PROP_NAME,
526 (char *)name);
527
528 (void) snprintf(chrbuf, sizeof (chrbuf), "%u,raw", minor);
529
530 if (ddi_create_minor_node(zfs_dip, chrbuf, S_IFCHR,
531 minor, DDI_PSEUDO, 0) == DDI_FAILURE) {
532 ddi_soft_state_free(zfsdev_state, minor);
533 dmu_objset_disown(os, FTAG);
534 mutex_exit(&zfsdev_state_lock);
535 return (SET_ERROR(EAGAIN));
536 }
537
538 (void) snprintf(blkbuf, sizeof (blkbuf), "%u", minor);
539
540 if (ddi_create_minor_node(zfs_dip, blkbuf, S_IFBLK,
541 minor, DDI_PSEUDO, 0) == DDI_FAILURE) {
542 ddi_remove_minor_node(zfs_dip, chrbuf);
543 ddi_soft_state_free(zfsdev_state, minor);
544 dmu_objset_disown(os, FTAG);
545 mutex_exit(&zfsdev_state_lock);
546 return (SET_ERROR(EAGAIN));
547 }
548
549 zs = ddi_get_soft_state(zfsdev_state, minor);
550 zs->zss_type = ZSST_ZVOL;
551 zv = zs->zss_data = kmem_zalloc(sizeof (zvol_state_t), KM_SLEEP);
552 (void) strlcpy(zv->zv_name, name, MAXPATHLEN);
553 zv->zv_min_bs = DEV_BSHIFT;
554 zv->zv_minor = minor;
555 zv->zv_objset = os;
556 if (dmu_objset_is_snapshot(os) || !spa_writeable(dmu_objset_spa(os)))
557 zv->zv_flags |= ZVOL_RDONLY;
558 rangelock_init(&zv->zv_rangelock, NULL, NULL);
559 list_create(&zv->zv_extents, sizeof (zvol_extent_t),
560 offsetof(zvol_extent_t, ze_node));
561 /* get and cache the blocksize */
562 error = dmu_object_info(os, ZVOL_OBJ, &doi);
563 ASSERT(error == 0);
564 zv->zv_volblocksize = doi.doi_data_block_size;
565
566 if (spa_writeable(dmu_objset_spa(os))) {
567 if (zil_replay_disable)
568 zil_destroy(dmu_objset_zil(os), B_FALSE);
569 else
570 zil_replay(os, zv, zvol_replay_vector);
571 }
572 dmu_objset_disown(os, FTAG);
573 zv->zv_objset = NULL;
574
575 zvol_minors++;
576
577 mutex_exit(&zfsdev_state_lock);
578
579 return (0);
580 }
581
582 /*
583 * Remove minor node for the specified volume.
584 */
585 static int
586 zvol_remove_zv(zvol_state_t *zv)
587 {
588 char nmbuf[20];
589 minor_t minor = zv->zv_minor;
590
591 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
592 if (zv->zv_total_opens != 0)
593 return (SET_ERROR(EBUSY));
594
595 (void) snprintf(nmbuf, sizeof (nmbuf), "%u,raw", minor);
596 ddi_remove_minor_node(zfs_dip, nmbuf);
597
598 (void) snprintf(nmbuf, sizeof (nmbuf), "%u", minor);
599 ddi_remove_minor_node(zfs_dip, nmbuf);
600
601 rangelock_fini(&zv->zv_rangelock);
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 = dnode_hold(os, ZVOL_OBJ, zvol_tag, &zv->zv_dn);
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 dnode_rele(zv->zv_dn, zvol_tag);
675 zv->zv_dn = 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 /* ARGSUSED */
976 static void
977 zvol_get_done(zgd_t *zgd, int error)
978 {
979 if (zgd->zgd_db)
980 dmu_buf_rele(zgd->zgd_db, zgd);
981
982 rangelock_exit(zgd->zgd_lr);
983
984 kmem_free(zgd, sizeof (zgd_t));
985 }
986
987 /*
988 * Get data to generate a TX_WRITE intent log record.
989 */
990 static int
991 zvol_get_data(void *arg, lr_write_t *lr, char *buf, struct lwb *lwb, zio_t *zio)
992 {
993 zvol_state_t *zv = arg;
994 uint64_t offset = lr->lr_offset;
995 uint64_t size = lr->lr_length; /* length of user data */
996 dmu_buf_t *db;
997 zgd_t *zgd;
998 int error;
999
1000 ASSERT3P(lwb, !=, NULL);
1001 ASSERT3P(zio, !=, NULL);
1002 ASSERT3U(size, !=, 0);
1003
1004 zgd = kmem_zalloc(sizeof (zgd_t), KM_SLEEP);
1005 zgd->zgd_lwb = lwb;
1006
1007 /*
1008 * Write records come in two flavors: immediate and indirect.
1009 * For small writes it's cheaper to store the data with the
1010 * log record (immediate); for large writes it's cheaper to
1011 * sync the data and get a pointer to it (indirect) so that
1012 * we don't have to write the data twice.
1013 */
1014 if (buf != NULL) { /* immediate write */
1015 zgd->zgd_lr = rangelock_enter(&zv->zv_rangelock, offset, size,
1016 RL_READER);
1017 error = dmu_read_by_dnode(zv->zv_dn, offset, size, buf,
1018 DMU_READ_NO_PREFETCH);
1019 } else { /* indirect write */
1020 /*
1021 * Have to lock the whole block to ensure when it's written out
1022 * and its checksum is being calculated that no one can change
1023 * the data. Contrarily to zfs_get_data we need not re-check
1024 * blocksize after we get the lock because it cannot be changed.
1025 */
1026 size = zv->zv_volblocksize;
1027 offset = P2ALIGN(offset, size);
1028 zgd->zgd_lr = rangelock_enter(&zv->zv_rangelock, offset, size,
1029 RL_READER);
1030 error = dmu_buf_hold_by_dnode(zv->zv_dn, offset, zgd, &db,
1031 DMU_READ_NO_PREFETCH);
1032 if (error == 0) {
1033 blkptr_t *bp = &lr->lr_blkptr;
1034
1035 zgd->zgd_db = db;
1036 zgd->zgd_bp = bp;
1037
1038 ASSERT(db->db_offset == offset);
1039 ASSERT(db->db_size == size);
1040
1041 error = dmu_sync(zio, lr->lr_common.lrc_txg,
1042 zvol_get_done, zgd);
1043
1044 if (error == 0)
1045 return (0);
1046 }
1047 }
1048
1049 zvol_get_done(zgd, error);
1050
1051 return (error);
1052 }
1053
1054 /*
1055 * zvol_log_write() handles synchronous writes using TX_WRITE ZIL transactions.
1056 *
1057 * We store data in the log buffers if it's small enough.
1058 * Otherwise we will later flush the data out via dmu_sync().
1059 */
1060 ssize_t zvol_immediate_write_sz = 32768;
1061
1062 static void
1063 zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, offset_t off, ssize_t resid,
1064 boolean_t sync)
1065 {
1066 uint32_t blocksize = zv->zv_volblocksize;
1067 zilog_t *zilog = zv->zv_zilog;
1068 itx_wr_state_t write_state;
1069
1070 if (zil_replaying(zilog, tx))
1071 return;
1072
1073 if (zilog->zl_logbias == ZFS_LOGBIAS_THROUGHPUT)
1074 write_state = WR_INDIRECT;
1075 else if (!spa_has_slogs(zilog->zl_spa) &&
1076 resid >= blocksize && blocksize > zvol_immediate_write_sz)
1077 write_state = WR_INDIRECT;
1078 else if (sync)
1079 write_state = WR_COPIED;
1080 else
1081 write_state = WR_NEED_COPY;
1082
1083 while (resid) {
1084 itx_t *itx;
1085 lr_write_t *lr;
1086 itx_wr_state_t wr_state = write_state;
1087 ssize_t len = resid;
1088
1089 if (wr_state == WR_COPIED && resid > ZIL_MAX_COPIED_DATA)
1090 wr_state = WR_NEED_COPY;
1091 else if (wr_state == WR_INDIRECT)
1092 len = MIN(blocksize - P2PHASE(off, blocksize), resid);
1093
1094 itx = zil_itx_create(TX_WRITE, sizeof (*lr) +
1095 (wr_state == WR_COPIED ? len : 0));
1096 lr = (lr_write_t *)&itx->itx_lr;
1097 if (wr_state == WR_COPIED && dmu_read_by_dnode(zv->zv_dn,
1098 off, len, lr + 1, DMU_READ_NO_PREFETCH) != 0) {
1099 zil_itx_destroy(itx);
1100 itx = zil_itx_create(TX_WRITE, sizeof (*lr));
1101 lr = (lr_write_t *)&itx->itx_lr;
1102 wr_state = WR_NEED_COPY;
1103 }
1104
1105 itx->itx_wr_state = wr_state;
1106 lr->lr_foid = ZVOL_OBJ;
1107 lr->lr_offset = off;
1108 lr->lr_length = len;
1109 lr->lr_blkoff = 0;
1110 BP_ZERO(&lr->lr_blkptr);
1111
1112 itx->itx_private = zv;
1113 itx->itx_sync = sync;
1114
1115 zil_itx_assign(zilog, itx, tx);
1116
1117 off += len;
1118 resid -= len;
1119 }
1120 }
1121
1122 static int
1123 zvol_dumpio_vdev(vdev_t *vd, void *addr, uint64_t offset, uint64_t origoffset,
1124 uint64_t size, boolean_t doread, boolean_t isdump)
1125 {
1126 vdev_disk_t *dvd;
1127 int c;
1128 int numerrors = 0;
1129
1130 if (vd->vdev_ops == &vdev_mirror_ops ||
1131 vd->vdev_ops == &vdev_replacing_ops ||
1132 vd->vdev_ops == &vdev_spare_ops) {
1133 for (c = 0; c < vd->vdev_children; c++) {
1134 int err = zvol_dumpio_vdev(vd->vdev_child[c],
1135 addr, offset, origoffset, size, doread, isdump);
1136 if (err != 0) {
1137 numerrors++;
1138 } else if (doread) {
1139 break;
1140 }
1141 }
1142 }
1143
1144 if (!vd->vdev_ops->vdev_op_leaf && vd->vdev_ops != &vdev_raidz_ops)
1145 return (numerrors < vd->vdev_children ? 0 : EIO);
1146
1147 if (doread && !vdev_readable(vd))
1148 return (SET_ERROR(EIO));
1149 else if (!doread && !vdev_writeable(vd))
1150 return (SET_ERROR(EIO));
1151
1152 if (vd->vdev_ops == &vdev_raidz_ops) {
1153 return (vdev_raidz_physio(vd,
1154 addr, size, offset, origoffset, doread, isdump));
1155 }
1156
1157 offset += VDEV_LABEL_START_SIZE;
1158
1159 if (ddi_in_panic() || isdump) {
1160 ASSERT(!doread);
1161 if (doread)
1162 return (SET_ERROR(EIO));
1163 dvd = vd->vdev_tsd;
1164 ASSERT3P(dvd, !=, NULL);
1165 return (ldi_dump(dvd->vd_lh, addr, lbtodb(offset),
1166 lbtodb(size)));
1167 } else {
1168 dvd = vd->vdev_tsd;
1169 ASSERT3P(dvd, !=, NULL);
1170 return (vdev_disk_ldi_physio(dvd->vd_lh, addr, size,
1171 offset, doread ? B_READ : B_WRITE));
1172 }
1173 }
1174
1175 static int
1176 zvol_dumpio(zvol_state_t *zv, void *addr, uint64_t offset, uint64_t size,
1177 boolean_t doread, boolean_t isdump)
1178 {
1179 vdev_t *vd;
1180 int error;
1181 zvol_extent_t *ze;
1182 spa_t *spa = dmu_objset_spa(zv->zv_objset);
1183
1184 /* Must be sector aligned, and not stradle a block boundary. */
1185 if (P2PHASE(offset, DEV_BSIZE) || P2PHASE(size, DEV_BSIZE) ||
1186 P2BOUNDARY(offset, size, zv->zv_volblocksize)) {
1187 return (SET_ERROR(EINVAL));
1188 }
1189 ASSERT(size <= zv->zv_volblocksize);
1190
1191 /* Locate the extent this belongs to */
1192 ze = list_head(&zv->zv_extents);
1193 while (offset >= ze->ze_nblks * zv->zv_volblocksize) {
1194 offset -= ze->ze_nblks * zv->zv_volblocksize;
1195 ze = list_next(&zv->zv_extents, ze);
1196 }
1197
1198 if (ze == NULL)
1199 return (SET_ERROR(EINVAL));
1200
1201 if (!ddi_in_panic())
1202 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
1203
1204 vd = vdev_lookup_top(spa, DVA_GET_VDEV(&ze->ze_dva));
1205 offset += DVA_GET_OFFSET(&ze->ze_dva);
1206 error = zvol_dumpio_vdev(vd, addr, offset, DVA_GET_OFFSET(&ze->ze_dva),
1207 size, doread, isdump);
1208
1209 if (!ddi_in_panic())
1210 spa_config_exit(spa, SCL_STATE, FTAG);
1211
1212 return (error);
1213 }
1214
1215 int
1216 zvol_strategy(buf_t *bp)
1217 {
1218 zfs_soft_state_t *zs = NULL;
1219 zvol_state_t *zv;
1220 uint64_t off, volsize;
1221 size_t resid;
1222 char *addr;
1223 objset_t *os;
1224 int error = 0;
1225 boolean_t doread = bp->b_flags & B_READ;
1226 boolean_t is_dumpified;
1227 boolean_t sync;
1228
1229 if (getminor(bp->b_edev) == 0) {
1230 error = SET_ERROR(EINVAL);
1231 } else {
1232 zs = ddi_get_soft_state(zfsdev_state, getminor(bp->b_edev));
1233 if (zs == NULL)
1234 error = SET_ERROR(ENXIO);
1235 else if (zs->zss_type != ZSST_ZVOL)
1236 error = SET_ERROR(EINVAL);
1237 }
1238
1239 if (error) {
1240 bioerror(bp, error);
1241 biodone(bp);
1242 return (0);
1243 }
1244
1245 zv = zs->zss_data;
1246
1247 if (!(bp->b_flags & B_READ) && (zv->zv_flags & ZVOL_RDONLY)) {
1248 bioerror(bp, EROFS);
1249 biodone(bp);
1250 return (0);
1251 }
1252
1253 off = ldbtob(bp->b_blkno);
1254 volsize = zv->zv_volsize;
1255
1256 os = zv->zv_objset;
1257 ASSERT(os != NULL);
1258
1259 bp_mapin(bp);
1260 addr = bp->b_un.b_addr;
1261 resid = bp->b_bcount;
1262
1263 if (resid > 0 && (off < 0 || off >= volsize)) {
1264 bioerror(bp, EIO);
1265 biodone(bp);
1266 return (0);
1267 }
1268
1269 is_dumpified = zv->zv_flags & ZVOL_DUMPIFIED;
1270 sync = ((!(bp->b_flags & B_ASYNC) &&
1271 !(zv->zv_flags & ZVOL_WCE)) ||
1272 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS)) &&
1273 !doread && !is_dumpified;
1274
1275 ht_begin_unsafe();
1276
1277 /*
1278 * There must be no buffer changes when doing a dmu_sync() because
1279 * we can't change the data whilst calculating the checksum.
1280 */
1281 locked_range_t *lr = rangelock_enter(&zv->zv_rangelock, off, resid,
1282 doread ? RL_READER : RL_WRITER);
1283
1284 while (resid != 0 && off < volsize) {
1285 size_t size = MIN(resid, zvol_maxphys);
1286 if (is_dumpified) {
1287 size = MIN(size, P2END(off, zv->zv_volblocksize) - off);
1288 error = zvol_dumpio(zv, addr, off, size,
1289 doread, B_FALSE);
1290 } else if (doread) {
1291 error = dmu_read(os, ZVOL_OBJ, off, size, addr,
1292 DMU_READ_PREFETCH);
1293 } else {
1294 dmu_tx_t *tx = dmu_tx_create(os);
1295 dmu_tx_hold_write(tx, ZVOL_OBJ, off, size);
1296 error = dmu_tx_assign(tx, TXG_WAIT);
1297 if (error) {
1298 dmu_tx_abort(tx);
1299 } else {
1300 dmu_write(os, ZVOL_OBJ, off, size, addr, tx);
1301 zvol_log_write(zv, tx, off, size, sync);
1302 dmu_tx_commit(tx);
1303 }
1304 }
1305 if (error) {
1306 /* convert checksum errors into IO errors */
1307 if (error == ECKSUM)
1308 error = SET_ERROR(EIO);
1309 break;
1310 }
1311 off += size;
1312 addr += size;
1313 resid -= size;
1314 }
1315 rangelock_exit(lr);
1316
1317 if ((bp->b_resid = resid) == bp->b_bcount)
1318 bioerror(bp, off > volsize ? EINVAL : error);
1319
1320 if (sync)
1321 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1322 biodone(bp);
1323
1324 ht_end_unsafe();
1325
1326 return (0);
1327 }
1328
1329 /*
1330 * Set the buffer count to the zvol maximum transfer.
1331 * Using our own routine instead of the default minphys()
1332 * means that for larger writes we write bigger buffers on X86
1333 * (128K instead of 56K) and flush the disk write cache less often
1334 * (every zvol_maxphys - currently 1MB) instead of minphys (currently
1335 * 56K on X86 and 128K on sparc).
1336 */
1337 void
1338 zvol_minphys(struct buf *bp)
1339 {
1340 if (bp->b_bcount > zvol_maxphys)
1341 bp->b_bcount = zvol_maxphys;
1342 }
1343
1344 int
1345 zvol_dump(dev_t dev, caddr_t addr, daddr_t blkno, int nblocks)
1346 {
1347 minor_t minor = getminor(dev);
1348 zvol_state_t *zv;
1349 int error = 0;
1350 uint64_t size;
1351 uint64_t boff;
1352 uint64_t resid;
1353
1354 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1355 if (zv == NULL)
1356 return (SET_ERROR(ENXIO));
1357
1358 if ((zv->zv_flags & ZVOL_DUMPIFIED) == 0)
1359 return (SET_ERROR(EINVAL));
1360
1361 boff = ldbtob(blkno);
1362 resid = ldbtob(nblocks);
1363
1364 VERIFY3U(boff + resid, <=, zv->zv_volsize);
1365
1366 while (resid) {
1367 size = MIN(resid, P2END(boff, zv->zv_volblocksize) - boff);
1368 error = zvol_dumpio(zv, addr, boff, size, B_FALSE, B_TRUE);
1369 if (error)
1370 break;
1371 boff += size;
1372 addr += size;
1373 resid -= size;
1374 }
1375
1376 return (error);
1377 }
1378
1379 /*ARGSUSED*/
1380 int
1381 zvol_read(dev_t dev, uio_t *uio, cred_t *cr)
1382 {
1383 minor_t minor = getminor(dev);
1384 zvol_state_t *zv;
1385 uint64_t volsize;
1386 int error = 0;
1387
1388 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1389 if (zv == NULL)
1390 return (SET_ERROR(ENXIO));
1391
1392 volsize = zv->zv_volsize;
1393 if (uio->uio_resid > 0 &&
1394 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize))
1395 return (SET_ERROR(EIO));
1396
1397 if (zv->zv_flags & ZVOL_DUMPIFIED) {
1398 error = physio(zvol_strategy, NULL, dev, B_READ,
1399 zvol_minphys, uio);
1400 return (error);
1401 }
1402
1403 ht_begin_unsafe();
1404
1405 locked_range_t *lr = rangelock_enter(&zv->zv_rangelock,
1406 uio->uio_loffset, uio->uio_resid, 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 rangelock_exit(lr);
1423
1424 ht_end_unsafe();
1425
1426 return (error);
1427 }
1428
1429 /*ARGSUSED*/
1430 int
1431 zvol_write(dev_t dev, uio_t *uio, cred_t *cr)
1432 {
1433 minor_t minor = getminor(dev);
1434 zvol_state_t *zv;
1435 uint64_t volsize;
1436 int error = 0;
1437 boolean_t sync;
1438
1439 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1440 if (zv == NULL)
1441 return (SET_ERROR(ENXIO));
1442
1443 volsize = zv->zv_volsize;
1444 if (uio->uio_resid > 0 &&
1445 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize))
1446 return (SET_ERROR(EIO));
1447
1448 if (zv->zv_flags & ZVOL_DUMPIFIED) {
1449 error = physio(zvol_strategy, NULL, dev, B_WRITE,
1450 zvol_minphys, uio);
1451 return (error);
1452 }
1453
1454 ht_begin_unsafe();
1455
1456 sync = !(zv->zv_flags & ZVOL_WCE) ||
1457 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS);
1458
1459 locked_range_t *lr = rangelock_enter(&zv->zv_rangelock,
1460 uio->uio_loffset, uio->uio_resid, RL_WRITER);
1461 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) {
1462 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1);
1463 uint64_t off = uio->uio_loffset;
1464 dmu_tx_t *tx = dmu_tx_create(zv->zv_objset);
1465
1466 if (bytes > volsize - off) /* don't write past the end */
1467 bytes = volsize - off;
1468
1469 dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes);
1470 error = dmu_tx_assign(tx, TXG_WAIT);
1471 if (error) {
1472 dmu_tx_abort(tx);
1473 break;
1474 }
1475 error = dmu_write_uio_dnode(zv->zv_dn, uio, bytes, tx);
1476 if (error == 0)
1477 zvol_log_write(zv, tx, off, bytes, sync);
1478 dmu_tx_commit(tx);
1479
1480 if (error)
1481 break;
1482 }
1483 rangelock_exit(lr);
1484
1485 if (sync)
1486 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1487
1488 ht_end_unsafe();
1489
1490 return (error);
1491 }
1492
1493 int
1494 zvol_getefi(void *arg, int flag, uint64_t vs, uint8_t bs)
1495 {
1496 struct uuid uuid = EFI_RESERVED;
1497 efi_gpe_t gpe = { 0 };
1498 uint32_t crc;
1499 dk_efi_t efi;
1500 int length;
1501 char *ptr;
1502
1503 if (ddi_copyin(arg, &efi, sizeof (dk_efi_t), flag))
1504 return (SET_ERROR(EFAULT));
1505 ptr = (char *)(uintptr_t)efi.dki_data_64;
1506 length = efi.dki_length;
1507 /*
1508 * Some clients may attempt to request a PMBR for the
1509 * zvol. Currently this interface will return EINVAL to
1510 * such requests. These requests could be supported by
1511 * adding a check for lba == 0 and consing up an appropriate
1512 * PMBR.
1513 */
1514 if (efi.dki_lba < 1 || efi.dki_lba > 2 || length <= 0)
1515 return (SET_ERROR(EINVAL));
1516
1517 gpe.efi_gpe_StartingLBA = LE_64(34ULL);
1518 gpe.efi_gpe_EndingLBA = LE_64((vs >> bs) - 1);
1519 UUID_LE_CONVERT(gpe.efi_gpe_PartitionTypeGUID, uuid);
1520
1521 if (efi.dki_lba == 1) {
1522 efi_gpt_t gpt = { 0 };
1523
1524 gpt.efi_gpt_Signature = LE_64(EFI_SIGNATURE);
1525 gpt.efi_gpt_Revision = LE_32(EFI_VERSION_CURRENT);
1526 gpt.efi_gpt_HeaderSize = LE_32(EFI_HEADER_SIZE);
1527 gpt.efi_gpt_MyLBA = LE_64(1ULL);
1528 gpt.efi_gpt_FirstUsableLBA = LE_64(34ULL);
1529 gpt.efi_gpt_LastUsableLBA = LE_64((vs >> bs) - 1);
1530 gpt.efi_gpt_PartitionEntryLBA = LE_64(2ULL);
1531 gpt.efi_gpt_NumberOfPartitionEntries = LE_32(1);
1532 gpt.efi_gpt_SizeOfPartitionEntry =
1533 LE_32(sizeof (efi_gpe_t));
1534 CRC32(crc, &gpe, sizeof (gpe), -1U, crc32_table);
1535 gpt.efi_gpt_PartitionEntryArrayCRC32 = LE_32(~crc);
1536 CRC32(crc, &gpt, EFI_HEADER_SIZE, -1U, crc32_table);
1537 gpt.efi_gpt_HeaderCRC32 = LE_32(~crc);
1538 if (ddi_copyout(&gpt, ptr, MIN(sizeof (gpt), length),
1539 flag))
1540 return (SET_ERROR(EFAULT));
1541 ptr += sizeof (gpt);
1542 length -= sizeof (gpt);
1543 }
1544 if (length > 0 && ddi_copyout(&gpe, ptr, MIN(sizeof (gpe),
1545 length), flag))
1546 return (SET_ERROR(EFAULT));
1547 return (0);
1548 }
1549
1550 /*
1551 * BEGIN entry points to allow external callers access to the volume.
1552 */
1553 /*
1554 * Return the volume parameters needed for access from an external caller.
1555 * These values are invariant as long as the volume is held open.
1556 */
1557 int
1558 zvol_get_volume_params(minor_t minor, uint64_t *blksize,
1559 uint64_t *max_xfer_len, void **minor_hdl, void **objset_hdl, void **zil_hdl,
1560 void **rl_hdl, void **dnode_hdl)
1561 {
1562 zvol_state_t *zv;
1563
1564 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1565 if (zv == NULL)
1566 return (SET_ERROR(ENXIO));
1567 if (zv->zv_flags & ZVOL_DUMPIFIED)
1568 return (SET_ERROR(ENXIO));
1569
1570 ASSERT(blksize && max_xfer_len && minor_hdl &&
1571 objset_hdl && zil_hdl && rl_hdl && dnode_hdl);
1572
1573 *blksize = zv->zv_volblocksize;
1574 *max_xfer_len = (uint64_t)zvol_maxphys;
1575 *minor_hdl = zv;
1576 *objset_hdl = zv->zv_objset;
1577 *zil_hdl = zv->zv_zilog;
1578 *rl_hdl = &zv->zv_rangelock;
1579 *dnode_hdl = zv->zv_dn;
1580 return (0);
1581 }
1582
1583 /*
1584 * Return the current volume size to an external caller.
1585 * The size can change while the volume is open.
1586 */
1587 uint64_t
1588 zvol_get_volume_size(void *minor_hdl)
1589 {
1590 zvol_state_t *zv = minor_hdl;
1591
1592 return (zv->zv_volsize);
1593 }
1594
1595 /*
1596 * Return the current WCE setting to an external caller.
1597 * The WCE setting can change while the volume is open.
1598 */
1599 int
1600 zvol_get_volume_wce(void *minor_hdl)
1601 {
1602 zvol_state_t *zv = minor_hdl;
1603
1604 return ((zv->zv_flags & ZVOL_WCE) ? 1 : 0);
1605 }
1606
1607 /*
1608 * Entry point for external callers to zvol_log_write
1609 */
1610 void
1611 zvol_log_write_minor(void *minor_hdl, dmu_tx_t *tx, offset_t off, ssize_t resid,
1612 boolean_t sync)
1613 {
1614 zvol_state_t *zv = minor_hdl;
1615
1616 zvol_log_write(zv, tx, off, resid, sync);
1617 }
1618 /*
1619 * END entry points to allow external callers access to the volume.
1620 */
1621
1622 /*
1623 * Log a DKIOCFREE/free-long-range to the ZIL with TX_TRUNCATE.
1624 */
1625 static void
1626 zvol_log_truncate(zvol_state_t *zv, dmu_tx_t *tx, uint64_t off, uint64_t len,
1627 boolean_t sync)
1628 {
1629 itx_t *itx;
1630 lr_truncate_t *lr;
1631 zilog_t *zilog = zv->zv_zilog;
1632
1633 if (zil_replaying(zilog, tx))
1634 return;
1635
1636 itx = zil_itx_create(TX_TRUNCATE, sizeof (*lr));
1637 lr = (lr_truncate_t *)&itx->itx_lr;
1638 lr->lr_foid = ZVOL_OBJ;
1639 lr->lr_offset = off;
1640 lr->lr_length = len;
1641
1642 itx->itx_sync = sync;
1643 zil_itx_assign(zilog, itx, tx);
1644 }
1645
1646 /*
1647 * Dirtbag ioctls to support mkfs(1M) for UFS filesystems. See dkio(7I).
1648 * Also a dirtbag dkio ioctl for unmap/free-block functionality.
1649 */
1650 /*ARGSUSED*/
1651 int
1652 zvol_ioctl(dev_t dev, int cmd, intptr_t arg, int flag, cred_t *cr, int *rvalp)
1653 {
1654 zvol_state_t *zv;
1655 struct dk_callback *dkc;
1656 int error = 0;
1657 locked_range_t *lr;
1658
1659 mutex_enter(&zfsdev_state_lock);
1660
1661 zv = zfsdev_get_soft_state(getminor(dev), ZSST_ZVOL);
1662
1663 if (zv == NULL) {
1664 mutex_exit(&zfsdev_state_lock);
1665 return (SET_ERROR(ENXIO));
1666 }
1667 ASSERT(zv->zv_total_opens > 0);
1668
1669 switch (cmd) {
1670
1671 case DKIOCINFO:
1672 {
1673 struct dk_cinfo dki;
1674
1675 bzero(&dki, sizeof (dki));
1676 (void) strcpy(dki.dki_cname, "zvol");
1677 (void) strcpy(dki.dki_dname, "zvol");
1678 dki.dki_ctype = DKC_UNKNOWN;
1679 dki.dki_unit = getminor(dev);
1680 dki.dki_maxtransfer =
1681 1 << (SPA_OLD_MAXBLOCKSHIFT - zv->zv_min_bs);
1682 mutex_exit(&zfsdev_state_lock);
1683 if (ddi_copyout(&dki, (void *)arg, sizeof (dki), flag))
1684 error = SET_ERROR(EFAULT);
1685 return (error);
1686 }
1687
1688 case DKIOCGMEDIAINFO:
1689 {
1690 struct dk_minfo dkm;
1691
1692 bzero(&dkm, sizeof (dkm));
1693 dkm.dki_lbsize = 1U << zv->zv_min_bs;
1694 dkm.dki_capacity = zv->zv_volsize >> zv->zv_min_bs;
1695 dkm.dki_media_type = DK_UNKNOWN;
1696 mutex_exit(&zfsdev_state_lock);
1697 if (ddi_copyout(&dkm, (void *)arg, sizeof (dkm), flag))
1698 error = SET_ERROR(EFAULT);
1699 return (error);
1700 }
1701
1702 case DKIOCGMEDIAINFOEXT:
1703 {
1704 struct dk_minfo_ext dkmext;
1705
1706 bzero(&dkmext, sizeof (dkmext));
1707 dkmext.dki_lbsize = 1U << zv->zv_min_bs;
1708 dkmext.dki_pbsize = zv->zv_volblocksize;
1709 dkmext.dki_capacity = zv->zv_volsize >> zv->zv_min_bs;
1710 dkmext.dki_media_type = DK_UNKNOWN;
1711 mutex_exit(&zfsdev_state_lock);
1712 if (ddi_copyout(&dkmext, (void *)arg, sizeof (dkmext), flag))
1713 error = SET_ERROR(EFAULT);
1714 return (error);
1715 }
1716
1717 case DKIOCGETEFI:
1718 {
1719 uint64_t vs = zv->zv_volsize;
1720 uint8_t bs = zv->zv_min_bs;
1721
1722 mutex_exit(&zfsdev_state_lock);
1723 error = zvol_getefi((void *)arg, flag, vs, bs);
1724 return (error);
1725 }
1726
1727 case DKIOCFLUSHWRITECACHE:
1728 dkc = (struct dk_callback *)arg;
1729 mutex_exit(&zfsdev_state_lock);
1730
1731 ht_begin_unsafe();
1732
1733 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1734 if ((flag & FKIOCTL) && dkc != NULL && dkc->dkc_callback) {
1735 (*dkc->dkc_callback)(dkc->dkc_cookie, error);
1736 error = 0;
1737 }
1738
1739 ht_end_unsafe();
1740
1741 return (error);
1742
1743 case DKIOCGETWCE:
1744 {
1745 int wce = (zv->zv_flags & ZVOL_WCE) ? 1 : 0;
1746 if (ddi_copyout(&wce, (void *)arg, sizeof (int),
1747 flag))
1748 error = SET_ERROR(EFAULT);
1749 break;
1750 }
1751 case DKIOCSETWCE:
1752 {
1753 int wce;
1754 if (ddi_copyin((void *)arg, &wce, sizeof (int),
1755 flag)) {
1756 error = SET_ERROR(EFAULT);
1757 break;
1758 }
1759 if (wce) {
1760 zv->zv_flags |= ZVOL_WCE;
1761 mutex_exit(&zfsdev_state_lock);
1762 } else {
1763 zv->zv_flags &= ~ZVOL_WCE;
1764 mutex_exit(&zfsdev_state_lock);
1765 ht_begin_unsafe();
1766 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1767 ht_end_unsafe();
1768 }
1769 return (0);
1770 }
1771
1772 case DKIOCGGEOM:
1773 case DKIOCGVTOC:
1774 /*
1775 * commands using these (like prtvtoc) expect ENOTSUP
1776 * since we're emulating an EFI label
1777 */
1778 error = SET_ERROR(ENOTSUP);
1779 break;
1780
1781 case DKIOCDUMPINIT:
1782 lr = rangelock_enter(&zv->zv_rangelock, 0, zv->zv_volsize,
1783 RL_WRITER);
1784 error = zvol_dumpify(zv);
1785 rangelock_exit(lr);
1786 break;
1787
1788 case DKIOCDUMPFINI:
1789 if (!(zv->zv_flags & ZVOL_DUMPIFIED))
1790 break;
1791 lr = rangelock_enter(&zv->zv_rangelock, 0, zv->zv_volsize,
1792 RL_WRITER);
1793 error = zvol_dump_fini(zv);
1794 rangelock_exit(lr);
1795 break;
1796
1797 case DKIOCFREE:
1798 {
1799 dkioc_free_list_t *dfl;
1800 dmu_tx_t *tx;
1801
1802 if (!zvol_unmap_enabled)
1803 break;
1804
1805 if (!(flag & FKIOCTL)) {
1806 error = dfl_copyin((void *)arg, &dfl, flag, KM_SLEEP);
1807 if (error != 0)
1808 break;
1809 } else {
1810 dfl = (dkioc_free_list_t *)arg;
1811 ASSERT3U(dfl->dfl_num_exts, <=, DFL_COPYIN_MAX_EXTS);
1812 if (dfl->dfl_num_exts > DFL_COPYIN_MAX_EXTS) {
1813 error = SET_ERROR(EINVAL);
1814 break;
1815 }
1816 }
1817
1818 mutex_exit(&zfsdev_state_lock);
1819
1820 ht_begin_unsafe();
1821
1822 for (int i = 0; i < dfl->dfl_num_exts; i++) {
1823 uint64_t start = dfl->dfl_exts[i].dfle_start,
1824 length = dfl->dfl_exts[i].dfle_length,
1825 end = start + length;
1826
1827 /*
1828 * Apply Postel's Law to length-checking. If they
1829 * overshoot, just blank out until the end, if there's
1830 * a need to blank out anything.
1831 */
1832 if (start >= zv->zv_volsize)
1833 continue; /* No need to do anything... */
1834 if (end > zv->zv_volsize) {
1835 end = DMU_OBJECT_END;
1836 length = end - start;
1837 }
1838
1839 lr = rangelock_enter(&zv->zv_rangelock, start, length,
1840 RL_WRITER);
1841 tx = dmu_tx_create(zv->zv_objset);
1842 error = dmu_tx_assign(tx, TXG_WAIT);
1843 if (error != 0) {
1844 dmu_tx_abort(tx);
1845 } else {
1846 zvol_log_truncate(zv, tx, start, length,
1847 B_TRUE);
1848 dmu_tx_commit(tx);
1849 error = dmu_free_long_range(zv->zv_objset,
1850 ZVOL_OBJ, start, length);
1851 }
1852
1853 rangelock_exit(lr);
1854
1855 if (error != 0)
1856 break;
1857 }
1858
1859 /*
1860 * If the write-cache is disabled, 'sync' property
1861 * is set to 'always', or if the caller is asking for
1862 * a synchronous free, commit this operation to the zil.
1863 * This will sync any previous uncommitted writes to the
1864 * zvol object.
1865 * Can be overridden by the zvol_unmap_sync_enabled tunable.
1866 */
1867 if ((error == 0) && zvol_unmap_sync_enabled &&
1868 (!(zv->zv_flags & ZVOL_WCE) ||
1869 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS) ||
1870 (dfl->dfl_flags & DF_WAIT_SYNC))) {
1871 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1872 }
1873
1874 if (!(flag & FKIOCTL))
1875 dfl_free(dfl);
1876
1877 ht_end_unsafe();
1878
1879 return (error);
1880 }
1881
1882 default:
1883 error = SET_ERROR(ENOTTY);
1884 break;
1885
1886 }
1887 mutex_exit(&zfsdev_state_lock);
1888 return (error);
1889 }
1890
1891 int
1892 zvol_busy(void)
1893 {
1894 return (zvol_minors != 0);
1895 }
1896
1897 void
1898 zvol_init(void)
1899 {
1900 VERIFY(ddi_soft_state_init(&zfsdev_state, sizeof (zfs_soft_state_t),
1901 1) == 0);
1902 mutex_init(&zfsdev_state_lock, NULL, MUTEX_DEFAULT, NULL);
1903 }
1904
1905 void
1906 zvol_fini(void)
1907 {
1908 mutex_destroy(&zfsdev_state_lock);
1909 ddi_soft_state_fini(&zfsdev_state);
1910 }
1911
1912 /*ARGSUSED*/
1913 static int
1914 zfs_mvdev_dump_feature_check(void *arg, dmu_tx_t *tx)
1915 {
1916 spa_t *spa = dmu_tx_pool(tx)->dp_spa;
1917
1918 if (spa_feature_is_active(spa, SPA_FEATURE_MULTI_VDEV_CRASH_DUMP))
1919 return (1);
1920 return (0);
1921 }
1922
1923 /*ARGSUSED*/
1924 static void
1925 zfs_mvdev_dump_activate_feature_sync(void *arg, dmu_tx_t *tx)
1926 {
1927 spa_t *spa = dmu_tx_pool(tx)->dp_spa;
1928
1929 spa_feature_incr(spa, SPA_FEATURE_MULTI_VDEV_CRASH_DUMP, tx);
1930 }
1931
1932 static int
1933 zvol_dump_init(zvol_state_t *zv, boolean_t resize)
1934 {
1935 dmu_tx_t *tx;
1936 int error;
1937 objset_t *os = zv->zv_objset;
1938 spa_t *spa = dmu_objset_spa(os);
1939 vdev_t *vd = spa->spa_root_vdev;
1940 nvlist_t *nv = NULL;
1941 uint64_t version = spa_version(spa);
1942 uint64_t checksum, compress, refresrv, vbs, dedup;
1943
1944 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
1945 ASSERT(vd->vdev_ops == &vdev_root_ops);
1946
1947 error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, 0,
1948 DMU_OBJECT_END);
1949 if (error != 0)
1950 return (error);
1951 /* wait for dmu_free_long_range to actually free the blocks */
1952 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
1953
1954 /*
1955 * If the pool on which the dump device is being initialized has more
1956 * than one child vdev, check that the MULTI_VDEV_CRASH_DUMP feature is
1957 * enabled. If so, bump that feature's counter to indicate that the
1958 * feature is active. We also check the vdev type to handle the
1959 * following case:
1960 * # zpool create test raidz disk1 disk2 disk3
1961 * Now have spa_root_vdev->vdev_children == 1 (the raidz vdev),
1962 * the raidz vdev itself has 3 children.
1963 */
1964 if (vd->vdev_children > 1 || vd->vdev_ops == &vdev_raidz_ops) {
1965 if (!spa_feature_is_enabled(spa,
1966 SPA_FEATURE_MULTI_VDEV_CRASH_DUMP))
1967 return (SET_ERROR(ENOTSUP));
1968 (void) dsl_sync_task(spa_name(spa),
1969 zfs_mvdev_dump_feature_check,
1970 zfs_mvdev_dump_activate_feature_sync, NULL,
1971 2, ZFS_SPACE_CHECK_RESERVED);
1972 }
1973
1974 if (!resize) {
1975 error = dsl_prop_get_integer(zv->zv_name,
1976 zfs_prop_to_name(ZFS_PROP_COMPRESSION), &compress, NULL);
1977 if (error == 0) {
1978 error = dsl_prop_get_integer(zv->zv_name,
1979 zfs_prop_to_name(ZFS_PROP_CHECKSUM), &checksum,
1980 NULL);
1981 }
1982 if (error == 0) {
1983 error = dsl_prop_get_integer(zv->zv_name,
1984 zfs_prop_to_name(ZFS_PROP_REFRESERVATION),
1985 &refresrv, NULL);
1986 }
1987 if (error == 0) {
1988 error = dsl_prop_get_integer(zv->zv_name,
1989 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &vbs,
1990 NULL);
1991 }
1992 if (version >= SPA_VERSION_DEDUP && error == 0) {
1993 error = dsl_prop_get_integer(zv->zv_name,
1994 zfs_prop_to_name(ZFS_PROP_DEDUP), &dedup, NULL);
1995 }
1996 }
1997 if (error != 0)
1998 return (error);
1999
2000 tx = dmu_tx_create(os);
2001 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
2002 dmu_tx_hold_bonus(tx, ZVOL_OBJ);
2003 error = dmu_tx_assign(tx, TXG_WAIT);
2004 if (error != 0) {
2005 dmu_tx_abort(tx);
2006 return (error);
2007 }
2008
2009 /*
2010 * If we are resizing the dump device then we only need to
2011 * update the refreservation to match the newly updated
2012 * zvolsize. Otherwise, we save off the original state of the
2013 * zvol so that we can restore them if the zvol is ever undumpified.
2014 */
2015 if (resize) {
2016 error = zap_update(os, ZVOL_ZAP_OBJ,
2017 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1,
2018 &zv->zv_volsize, tx);
2019 } else {
2020 error = zap_update(os, ZVOL_ZAP_OBJ,
2021 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1,
2022 &compress, tx);
2023 if (error == 0) {
2024 error = zap_update(os, ZVOL_ZAP_OBJ,
2025 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1,
2026 &checksum, tx);
2027 }
2028 if (error == 0) {
2029 error = zap_update(os, ZVOL_ZAP_OBJ,
2030 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1,
2031 &refresrv, tx);
2032 }
2033 if (error == 0) {
2034 error = zap_update(os, ZVOL_ZAP_OBJ,
2035 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1,
2036 &vbs, tx);
2037 }
2038 if (error == 0) {
2039 error = dmu_object_set_blocksize(
2040 os, ZVOL_OBJ, SPA_OLD_MAXBLOCKSIZE, 0, tx);
2041 }
2042 if (version >= SPA_VERSION_DEDUP && error == 0) {
2043 error = zap_update(os, ZVOL_ZAP_OBJ,
2044 zfs_prop_to_name(ZFS_PROP_DEDUP), 8, 1,
2045 &dedup, tx);
2046 }
2047 if (error == 0)
2048 zv->zv_volblocksize = SPA_OLD_MAXBLOCKSIZE;
2049 }
2050 dmu_tx_commit(tx);
2051
2052 /*
2053 * We only need update the zvol's property if we are initializing
2054 * the dump area for the first time.
2055 */
2056 if (error == 0 && !resize) {
2057 /*
2058 * If MULTI_VDEV_CRASH_DUMP is active, use the NOPARITY checksum
2059 * function. Otherwise, use the old default -- OFF.
2060 */
2061 checksum = spa_feature_is_active(spa,
2062 SPA_FEATURE_MULTI_VDEV_CRASH_DUMP) ? ZIO_CHECKSUM_NOPARITY :
2063 ZIO_CHECKSUM_OFF;
2064
2065 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2066 VERIFY(nvlist_add_uint64(nv,
2067 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 0) == 0);
2068 VERIFY(nvlist_add_uint64(nv,
2069 zfs_prop_to_name(ZFS_PROP_COMPRESSION),
2070 ZIO_COMPRESS_OFF) == 0);
2071 VERIFY(nvlist_add_uint64(nv,
2072 zfs_prop_to_name(ZFS_PROP_CHECKSUM),
2073 checksum) == 0);
2074 if (version >= SPA_VERSION_DEDUP) {
2075 VERIFY(nvlist_add_uint64(nv,
2076 zfs_prop_to_name(ZFS_PROP_DEDUP),
2077 ZIO_CHECKSUM_OFF) == 0);
2078 }
2079
2080 error = zfs_set_prop_nvlist(zv->zv_name, ZPROP_SRC_LOCAL,
2081 nv, NULL);
2082 nvlist_free(nv);
2083 }
2084
2085 /* Allocate the space for the dump */
2086 if (error == 0)
2087 error = zvol_prealloc(zv);
2088 return (error);
2089 }
2090
2091 static int
2092 zvol_dumpify(zvol_state_t *zv)
2093 {
2094 int error = 0;
2095 uint64_t dumpsize = 0;
2096 dmu_tx_t *tx;
2097 objset_t *os = zv->zv_objset;
2098
2099 if (zv->zv_flags & ZVOL_RDONLY)
2100 return (SET_ERROR(EROFS));
2101
2102 if (zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE,
2103 8, 1, &dumpsize) != 0 || dumpsize != zv->zv_volsize) {
2104 boolean_t resize = (dumpsize > 0);
2105
2106 if ((error = zvol_dump_init(zv, resize)) != 0) {
2107 (void) zvol_dump_fini(zv);
2108 return (error);
2109 }
2110 }
2111
2112 /*
2113 * Build up our lba mapping.
2114 */
2115 error = zvol_get_lbas(zv);
2116 if (error) {
2117 (void) zvol_dump_fini(zv);
2118 return (error);
2119 }
2120
2121 tx = dmu_tx_create(os);
2122 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
2123 error = dmu_tx_assign(tx, TXG_WAIT);
2124 if (error) {
2125 dmu_tx_abort(tx);
2126 (void) zvol_dump_fini(zv);
2127 return (error);
2128 }
2129
2130 zv->zv_flags |= ZVOL_DUMPIFIED;
2131 error = zap_update(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, 8, 1,
2132 &zv->zv_volsize, tx);
2133 dmu_tx_commit(tx);
2134
2135 if (error) {
2136 (void) zvol_dump_fini(zv);
2137 return (error);
2138 }
2139
2140 txg_wait_synced(dmu_objset_pool(os), 0);
2141 return (0);
2142 }
2143
2144 static int
2145 zvol_dump_fini(zvol_state_t *zv)
2146 {
2147 dmu_tx_t *tx;
2148 objset_t *os = zv->zv_objset;
2149 nvlist_t *nv;
2150 int error = 0;
2151 uint64_t checksum, compress, refresrv, vbs, dedup;
2152 uint64_t version = spa_version(dmu_objset_spa(zv->zv_objset));
2153
2154 /*
2155 * Attempt to restore the zvol back to its pre-dumpified state.
2156 * This is a best-effort attempt as it's possible that not all
2157 * of these properties were initialized during the dumpify process
2158 * (i.e. error during zvol_dump_init).
2159 */
2160
2161 tx = dmu_tx_create(os);
2162 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
2163 error = dmu_tx_assign(tx, TXG_WAIT);
2164 if (error) {
2165 dmu_tx_abort(tx);
2166 return (error);
2167 }
2168 (void) zap_remove(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, tx);
2169 dmu_tx_commit(tx);
2170
2171 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2172 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1, &checksum);
2173 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2174 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1, &compress);
2175 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2176 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, &refresrv);
2177 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2178 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1, &vbs);
2179
2180 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2181 (void) nvlist_add_uint64(nv,
2182 zfs_prop_to_name(ZFS_PROP_CHECKSUM), checksum);
2183 (void) nvlist_add_uint64(nv,
2184 zfs_prop_to_name(ZFS_PROP_COMPRESSION), compress);
2185 (void) nvlist_add_uint64(nv,
2186 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), refresrv);
2187 if (version >= SPA_VERSION_DEDUP &&
2188 zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2189 zfs_prop_to_name(ZFS_PROP_DEDUP), 8, 1, &dedup) == 0) {
2190 (void) nvlist_add_uint64(nv,
2191 zfs_prop_to_name(ZFS_PROP_DEDUP), dedup);
2192 }
2193 (void) zfs_set_prop_nvlist(zv->zv_name, ZPROP_SRC_LOCAL,
2194 nv, NULL);
2195 nvlist_free(nv);
2196
2197 zvol_free_extents(zv);
2198 zv->zv_flags &= ~ZVOL_DUMPIFIED;
2199 (void) dmu_free_long_range(os, ZVOL_OBJ, 0, DMU_OBJECT_END);
2200 /* wait for dmu_free_long_range to actually free the blocks */
2201 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
2202 tx = dmu_tx_create(os);
2203 dmu_tx_hold_bonus(tx, ZVOL_OBJ);
2204 error = dmu_tx_assign(tx, TXG_WAIT);
2205 if (error) {
2206 dmu_tx_abort(tx);
2207 return (error);
2208 }
2209 if (dmu_object_set_blocksize(os, ZVOL_OBJ, vbs, 0, tx) == 0)
2210 zv->zv_volblocksize = vbs;
2211 dmu_tx_commit(tx);
2212
2213 return (0);
2214 }