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) 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 #include <sys/dkioc_free_util.h>
93 #include <sys/zfs_rlock.h>
94
95 #include "zfs_namecheck.h"
96
97 void *zfsdev_state;
98 static char *zvol_tag = "zvol_tag";
99
100 #define ZVOL_DUMPSIZE "dumpsize"
101
102 /*
103 * This lock protects the zfsdev_state structure from being modified
104 * while it's being used, e.g. an open that comes in before a create
105 * finishes. It also protects temporary opens of the dataset so that,
106 * e.g., an open doesn't get a spurious EBUSY.
107 */
108 kmutex_t zfsdev_state_lock;
109 static uint32_t zvol_minors;
110
111 typedef struct zvol_extent {
112 list_node_t ze_node;
113 dva_t ze_dva; /* dva associated with this extent */
114 uint64_t ze_nblks; /* number of blocks in extent */
115 } zvol_extent_t;
116
117 /*
118 * The in-core state of each volume.
119 */
120 typedef struct zvol_state {
121 char zv_name[MAXPATHLEN]; /* pool/dd name */
122 uint64_t zv_volsize; /* amount of space we advertise */
123 uint64_t zv_volblocksize; /* volume block size */
124 minor_t zv_minor; /* minor number */
125 uint8_t zv_min_bs; /* minimum addressable block shift */
126 uint8_t zv_flags; /* readonly, dumpified, etc. */
127 objset_t *zv_objset; /* objset handle */
128 uint32_t zv_open_count[OTYPCNT]; /* open counts */
129 uint32_t zv_total_opens; /* total open count */
130 zilog_t *zv_zilog; /* ZIL handle */
131 list_t zv_extents; /* List of extents for dump */
132 rangelock_t zv_rangelock;
133 dnode_t *zv_dn; /* dnode hold */
134 } zvol_state_t;
135
136 /*
137 * zvol specific flags
138 */
139 #define ZVOL_RDONLY 0x1
140 #define ZVOL_DUMPIFIED 0x2
141 #define ZVOL_EXCL 0x4
142 #define ZVOL_WCE 0x8
143
144 /*
145 * zvol maximum transfer in one DMU tx.
146 */
147 int zvol_maxphys = DMU_MAX_ACCESS/2;
148
149 /*
150 * Toggle unmap functionality.
151 */
152 boolean_t zvol_unmap_enabled = B_TRUE;
153
154 /*
155 * If true, unmaps requested as synchronous are executed synchronously,
156 * otherwise all unmaps are asynchronous.
157 */
158 boolean_t zvol_unmap_sync_enabled = B_FALSE;
159
160 extern int zfs_set_prop_nvlist(const char *, zprop_source_t,
161 nvlist_t *, nvlist_t *);
162 static int zvol_remove_zv(zvol_state_t *);
163 static int zvol_get_data(void *arg, lr_write_t *lr, char *buf,
164 struct lwb *lwb, zio_t *zio);
165 static int zvol_dumpify(zvol_state_t *zv);
166 static int zvol_dump_fini(zvol_state_t *zv);
167 static int zvol_dump_init(zvol_state_t *zv, boolean_t resize);
168
169 static void
170 zvol_size_changed(zvol_state_t *zv, uint64_t volsize)
171 {
172 dev_t dev = makedevice(ddi_driver_major(zfs_dip), zv->zv_minor);
173
174 zv->zv_volsize = volsize;
175 VERIFY(ddi_prop_update_int64(dev, zfs_dip,
176 "Size", volsize) == DDI_SUCCESS);
177 VERIFY(ddi_prop_update_int64(dev, zfs_dip,
178 "Nblocks", lbtodb(volsize)) == DDI_SUCCESS);
179
180 /* Notify specfs to invalidate the cached size */
181 spec_size_invalidate(dev, VBLK);
182 spec_size_invalidate(dev, VCHR);
183 }
184
185 int
186 zvol_check_volsize(uint64_t volsize, uint64_t blocksize)
187 {
188 if (volsize == 0)
189 return (SET_ERROR(EINVAL));
190
191 if (volsize % blocksize != 0)
192 return (SET_ERROR(EINVAL));
193
194 #ifdef _ILP32
195 if (volsize - 1 > SPEC_MAXOFFSET_T)
196 return (SET_ERROR(EOVERFLOW));
197 #endif
198 return (0);
199 }
200
201 int
202 zvol_check_volblocksize(uint64_t volblocksize)
203 {
204 if (volblocksize < SPA_MINBLOCKSIZE ||
205 volblocksize > SPA_OLD_MAXBLOCKSIZE ||
206 !ISP2(volblocksize))
207 return (SET_ERROR(EDOM));
208
209 return (0);
210 }
211
212 int
213 zvol_get_stats(objset_t *os, nvlist_t *nv)
214 {
215 int error;
216 dmu_object_info_t doi;
217 uint64_t val;
218
219 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &val);
220 if (error)
221 return (error);
222
223 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLSIZE, val);
224
225 error = dmu_object_info(os, ZVOL_OBJ, &doi);
226
227 if (error == 0) {
228 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLBLOCKSIZE,
229 doi.doi_data_block_size);
230 }
231
232 return (error);
233 }
234
235 static zvol_state_t *
236 zvol_minor_lookup(const char *name)
237 {
238 minor_t minor;
239 zvol_state_t *zv;
240
241 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
242
243 for (minor = 1; minor <= ZFSDEV_MAX_MINOR; minor++) {
244 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
245 if (zv == NULL)
246 continue;
247 if (strcmp(zv->zv_name, name) == 0)
248 return (zv);
249 }
250
251 return (NULL);
252 }
253
254 /* extent mapping arg */
255 struct maparg {
256 zvol_state_t *ma_zv;
257 uint64_t ma_blks;
258 };
259
260 /*ARGSUSED*/
261 static int
262 zvol_map_block(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
263 const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
264 {
265 struct maparg *ma = arg;
266 zvol_extent_t *ze;
267 int bs = ma->ma_zv->zv_volblocksize;
268
269 if (bp == NULL || BP_IS_HOLE(bp) ||
270 zb->zb_object != ZVOL_OBJ || zb->zb_level != 0)
271 return (0);
272
273 VERIFY(!BP_IS_EMBEDDED(bp));
274
275 VERIFY3U(ma->ma_blks, ==, zb->zb_blkid);
276 ma->ma_blks++;
277
278 /* Abort immediately if we have encountered gang blocks */
279 if (BP_IS_GANG(bp))
280 return (SET_ERROR(EFRAGS));
281
282 /*
283 * See if the block is at the end of the previous extent.
284 */
285 ze = list_tail(&ma->ma_zv->zv_extents);
286 if (ze &&
287 DVA_GET_VDEV(BP_IDENTITY(bp)) == DVA_GET_VDEV(&ze->ze_dva) &&
288 DVA_GET_OFFSET(BP_IDENTITY(bp)) ==
289 DVA_GET_OFFSET(&ze->ze_dva) + ze->ze_nblks * bs) {
290 ze->ze_nblks++;
291 return (0);
292 }
293
294 dprintf_bp(bp, "%s", "next blkptr:");
295
296 /* start a new extent */
297 ze = kmem_zalloc(sizeof (zvol_extent_t), KM_SLEEP);
298 ze->ze_dva = bp->blk_dva[0]; /* structure assignment */
299 ze->ze_nblks = 1;
300 list_insert_tail(&ma->ma_zv->zv_extents, ze);
301 return (0);
302 }
303
304 static void
305 zvol_free_extents(zvol_state_t *zv)
306 {
307 zvol_extent_t *ze;
308
309 while (ze = list_head(&zv->zv_extents)) {
310 list_remove(&zv->zv_extents, ze);
311 kmem_free(ze, sizeof (zvol_extent_t));
312 }
313 }
314
315 static int
316 zvol_get_lbas(zvol_state_t *zv)
317 {
318 objset_t *os = zv->zv_objset;
319 struct maparg ma;
320 int err;
321
322 ma.ma_zv = zv;
323 ma.ma_blks = 0;
324 zvol_free_extents(zv);
325
326 /* commit any in-flight changes before traversing the dataset */
327 txg_wait_synced(dmu_objset_pool(os), 0);
328 err = traverse_dataset(dmu_objset_ds(os), 0,
329 TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA, zvol_map_block, &ma);
330 if (err || ma.ma_blks != (zv->zv_volsize / zv->zv_volblocksize)) {
331 zvol_free_extents(zv);
332 return (err ? err : EIO);
333 }
334
335 return (0);
336 }
337
338 /* ARGSUSED */
339 void
340 zvol_create_cb(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx)
341 {
342 zfs_creat_t *zct = arg;
343 nvlist_t *nvprops = zct->zct_props;
344 int error;
345 uint64_t volblocksize, volsize;
346
347 VERIFY(nvlist_lookup_uint64(nvprops,
348 zfs_prop_to_name(ZFS_PROP_VOLSIZE), &volsize) == 0);
349 if (nvlist_lookup_uint64(nvprops,
350 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &volblocksize) != 0)
351 volblocksize = zfs_prop_default_numeric(ZFS_PROP_VOLBLOCKSIZE);
352
353 /*
354 * These properties must be removed from the list so the generic
355 * property setting step won't apply to them.
356 */
357 VERIFY(nvlist_remove_all(nvprops,
358 zfs_prop_to_name(ZFS_PROP_VOLSIZE)) == 0);
359 (void) nvlist_remove_all(nvprops,
360 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE));
361
362 error = dmu_object_claim(os, ZVOL_OBJ, DMU_OT_ZVOL, volblocksize,
363 DMU_OT_NONE, 0, tx);
364 ASSERT(error == 0);
365
366 error = zap_create_claim(os, ZVOL_ZAP_OBJ, DMU_OT_ZVOL_PROP,
367 DMU_OT_NONE, 0, tx);
368 ASSERT(error == 0);
369
370 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize, tx);
371 ASSERT(error == 0);
372 }
373
374 /*
375 * Replay a TX_TRUNCATE ZIL transaction if asked. TX_TRUNCATE is how we
376 * implement DKIOCFREE/free-long-range.
377 */
378 static int
379 zvol_replay_truncate(void *arg1, void *arg2, boolean_t byteswap)
380 {
381 zvol_state_t *zv = arg1;
382 lr_truncate_t *lr = arg2;
383 uint64_t offset, length;
384
385 if (byteswap)
386 byteswap_uint64_array(lr, sizeof (*lr));
387
388 offset = lr->lr_offset;
389 length = lr->lr_length;
390
391 return (dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, offset, length));
392 }
393
394 /*
395 * Replay a TX_WRITE ZIL transaction that didn't get committed
396 * after a system failure
397 */
398 static int
399 zvol_replay_write(void *arg1, void *arg2, boolean_t byteswap)
400 {
401 zvol_state_t *zv = arg1;
402 lr_write_t *lr = arg2;
403 objset_t *os = zv->zv_objset;
404 char *data = (char *)(lr + 1); /* data follows lr_write_t */
405 uint64_t offset, length;
406 dmu_tx_t *tx;
407 int error;
408
409 if (byteswap)
410 byteswap_uint64_array(lr, sizeof (*lr));
411
412 offset = lr->lr_offset;
413 length = lr->lr_length;
414
415 /* If it's a dmu_sync() block, write the whole block */
416 if (lr->lr_common.lrc_reclen == sizeof (lr_write_t)) {
417 uint64_t blocksize = BP_GET_LSIZE(&lr->lr_blkptr);
418 if (length < blocksize) {
419 offset -= offset % blocksize;
420 length = blocksize;
421 }
422 }
423
424 tx = dmu_tx_create(os);
425 dmu_tx_hold_write(tx, ZVOL_OBJ, offset, length);
426 error = dmu_tx_assign(tx, TXG_WAIT);
427 if (error) {
428 dmu_tx_abort(tx);
429 } else {
430 dmu_write(os, ZVOL_OBJ, offset, length, data, tx);
431 dmu_tx_commit(tx);
432 }
433
434 return (error);
435 }
436
437 /* ARGSUSED */
438 static int
439 zvol_replay_err(void *arg1, void *arg2, boolean_t byteswap)
440 {
441 return (SET_ERROR(ENOTSUP));
442 }
443
444 /*
445 * Callback vectors for replaying records.
446 * Only TX_WRITE and TX_TRUNCATE are needed for zvol.
447 */
448 zil_replay_func_t *zvol_replay_vector[TX_MAX_TYPE] = {
449 zvol_replay_err, /* 0 no such transaction type */
450 zvol_replay_err, /* TX_CREATE */
451 zvol_replay_err, /* TX_MKDIR */
452 zvol_replay_err, /* TX_MKXATTR */
453 zvol_replay_err, /* TX_SYMLINK */
454 zvol_replay_err, /* TX_REMOVE */
455 zvol_replay_err, /* TX_RMDIR */
456 zvol_replay_err, /* TX_LINK */
457 zvol_replay_err, /* TX_RENAME */
458 zvol_replay_write, /* TX_WRITE */
459 zvol_replay_truncate, /* TX_TRUNCATE */
460 zvol_replay_err, /* TX_SETATTR */
461 zvol_replay_err, /* TX_ACL */
462 zvol_replay_err, /* TX_CREATE_ACL */
463 zvol_replay_err, /* TX_CREATE_ATTR */
464 zvol_replay_err, /* TX_CREATE_ACL_ATTR */
465 zvol_replay_err, /* TX_MKDIR_ACL */
466 zvol_replay_err, /* TX_MKDIR_ATTR */
467 zvol_replay_err, /* TX_MKDIR_ACL_ATTR */
468 zvol_replay_err, /* TX_WRITE2 */
469 };
470
471 int
472 zvol_name2minor(const char *name, minor_t *minor)
473 {
474 zvol_state_t *zv;
475
476 mutex_enter(&zfsdev_state_lock);
477 zv = zvol_minor_lookup(name);
478 if (minor && zv)
479 *minor = zv->zv_minor;
480 mutex_exit(&zfsdev_state_lock);
481 return (zv ? 0 : -1);
482 }
483
484 /*
485 * Create a minor node (plus a whole lot more) for the specified volume.
486 */
487 int
488 zvol_create_minor(const char *name)
489 {
490 zfs_soft_state_t *zs;
491 zvol_state_t *zv;
492 objset_t *os;
493 dmu_object_info_t doi;
494 minor_t minor = 0;
495 char chrbuf[30], blkbuf[30];
496 int error;
497
498 mutex_enter(&zfsdev_state_lock);
499
500 if (zvol_minor_lookup(name) != NULL) {
501 mutex_exit(&zfsdev_state_lock);
502 return (SET_ERROR(EEXIST));
503 }
504
505 /* lie and say we're read-only */
506 error = dmu_objset_own(name, DMU_OST_ZVOL, B_TRUE, FTAG, &os);
507
508 if (error) {
509 mutex_exit(&zfsdev_state_lock);
510 return (error);
511 }
512
513 if ((minor = zfsdev_minor_alloc()) == 0) {
514 dmu_objset_disown(os, FTAG);
515 mutex_exit(&zfsdev_state_lock);
516 return (SET_ERROR(ENXIO));
517 }
518
519 if (ddi_soft_state_zalloc(zfsdev_state, minor) != DDI_SUCCESS) {
520 dmu_objset_disown(os, FTAG);
521 mutex_exit(&zfsdev_state_lock);
522 return (SET_ERROR(EAGAIN));
523 }
524 (void) ddi_prop_update_string(minor, zfs_dip, ZVOL_PROP_NAME,
525 (char *)name);
526
527 (void) snprintf(chrbuf, sizeof (chrbuf), "%u,raw", minor);
528
529 if (ddi_create_minor_node(zfs_dip, chrbuf, S_IFCHR,
530 minor, DDI_PSEUDO, 0) == DDI_FAILURE) {
531 ddi_soft_state_free(zfsdev_state, minor);
532 dmu_objset_disown(os, FTAG);
533 mutex_exit(&zfsdev_state_lock);
534 return (SET_ERROR(EAGAIN));
535 }
536
537 (void) snprintf(blkbuf, sizeof (blkbuf), "%u", minor);
538
539 if (ddi_create_minor_node(zfs_dip, blkbuf, S_IFBLK,
540 minor, DDI_PSEUDO, 0) == DDI_FAILURE) {
541 ddi_remove_minor_node(zfs_dip, chrbuf);
542 ddi_soft_state_free(zfsdev_state, minor);
543 dmu_objset_disown(os, FTAG);
544 mutex_exit(&zfsdev_state_lock);
545 return (SET_ERROR(EAGAIN));
546 }
547
548 zs = ddi_get_soft_state(zfsdev_state, minor);
549 zs->zss_type = ZSST_ZVOL;
550 zv = zs->zss_data = kmem_zalloc(sizeof (zvol_state_t), KM_SLEEP);
551 (void) strlcpy(zv->zv_name, name, MAXPATHLEN);
552 zv->zv_min_bs = DEV_BSHIFT;
553 zv->zv_minor = minor;
554 zv->zv_objset = os;
555 if (dmu_objset_is_snapshot(os) || !spa_writeable(dmu_objset_spa(os)))
556 zv->zv_flags |= ZVOL_RDONLY;
557 rangelock_init(&zv->zv_rangelock, NULL, NULL);
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 rangelock_fini(&zv->zv_rangelock);
601
602 kmem_free(zv, sizeof (zvol_state_t));
603
604 ddi_soft_state_free(zfsdev_state, minor);
605
606 zvol_minors--;
607 return (0);
608 }
609
610 int
611 zvol_remove_minor(const char *name)
612 {
613 zvol_state_t *zv;
614 int rc;
615
616 mutex_enter(&zfsdev_state_lock);
617 if ((zv = zvol_minor_lookup(name)) == NULL) {
618 mutex_exit(&zfsdev_state_lock);
619 return (SET_ERROR(ENXIO));
620 }
621 rc = zvol_remove_zv(zv);
622 mutex_exit(&zfsdev_state_lock);
623 return (rc);
624 }
625
626 int
627 zvol_first_open(zvol_state_t *zv)
628 {
629 objset_t *os;
630 uint64_t volsize;
631 int error;
632 uint64_t readonly;
633
634 /* lie and say we're read-only */
635 error = dmu_objset_own(zv->zv_name, DMU_OST_ZVOL, B_TRUE,
636 zvol_tag, &os);
637 if (error)
638 return (error);
639
640 zv->zv_objset = os;
641 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize);
642 if (error) {
643 ASSERT(error == 0);
644 dmu_objset_disown(os, zvol_tag);
645 return (error);
646 }
647
648 error = dnode_hold(os, ZVOL_OBJ, zvol_tag, &zv->zv_dn);
649 if (error) {
650 dmu_objset_disown(os, zvol_tag);
651 return (error);
652 }
653
654 zvol_size_changed(zv, volsize);
655 zv->zv_zilog = zil_open(os, zvol_get_data);
656
657 VERIFY(dsl_prop_get_integer(zv->zv_name, "readonly", &readonly,
658 NULL) == 0);
659 if (readonly || dmu_objset_is_snapshot(os) ||
660 !spa_writeable(dmu_objset_spa(os)))
661 zv->zv_flags |= ZVOL_RDONLY;
662 else
663 zv->zv_flags &= ~ZVOL_RDONLY;
664 return (error);
665 }
666
667 void
668 zvol_last_close(zvol_state_t *zv)
669 {
670 zil_close(zv->zv_zilog);
671 zv->zv_zilog = NULL;
672
673 dnode_rele(zv->zv_dn, zvol_tag);
674 zv->zv_dn = NULL;
675
676 /*
677 * Evict cached data
678 */
679 if (dsl_dataset_is_dirty(dmu_objset_ds(zv->zv_objset)) &&
680 !(zv->zv_flags & ZVOL_RDONLY))
681 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
682 dmu_objset_evict_dbufs(zv->zv_objset);
683
684 dmu_objset_disown(zv->zv_objset, zvol_tag);
685 zv->zv_objset = NULL;
686 }
687
688 int
689 zvol_prealloc(zvol_state_t *zv)
690 {
691 objset_t *os = zv->zv_objset;
692 dmu_tx_t *tx;
693 uint64_t refd, avail, usedobjs, availobjs;
694 uint64_t resid = zv->zv_volsize;
695 uint64_t off = 0;
696
697 /* Check the space usage before attempting to allocate the space */
698 dmu_objset_space(os, &refd, &avail, &usedobjs, &availobjs);
699 if (avail < zv->zv_volsize)
700 return (SET_ERROR(ENOSPC));
701
702 /* Free old extents if they exist */
703 zvol_free_extents(zv);
704
705 while (resid != 0) {
706 int error;
707 uint64_t bytes = MIN(resid, SPA_OLD_MAXBLOCKSIZE);
708
709 tx = dmu_tx_create(os);
710 dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes);
711 error = dmu_tx_assign(tx, TXG_WAIT);
712 if (error) {
713 dmu_tx_abort(tx);
714 (void) dmu_free_long_range(os, ZVOL_OBJ, 0, off);
715 return (error);
716 }
717 dmu_prealloc(os, ZVOL_OBJ, off, bytes, tx);
718 dmu_tx_commit(tx);
719 off += bytes;
720 resid -= bytes;
721 }
722 txg_wait_synced(dmu_objset_pool(os), 0);
723
724 return (0);
725 }
726
727 static int
728 zvol_update_volsize(objset_t *os, uint64_t volsize)
729 {
730 dmu_tx_t *tx;
731 int error;
732
733 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
734
735 tx = dmu_tx_create(os);
736 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
737 dmu_tx_mark_netfree(tx);
738 error = dmu_tx_assign(tx, TXG_WAIT);
739 if (error) {
740 dmu_tx_abort(tx);
741 return (error);
742 }
743
744 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1,
745 &volsize, tx);
746 dmu_tx_commit(tx);
747
748 if (error == 0)
749 error = dmu_free_long_range(os,
750 ZVOL_OBJ, volsize, DMU_OBJECT_END);
751 return (error);
752 }
753
754 void
755 zvol_remove_minors(const char *name)
756 {
757 zvol_state_t *zv;
758 char *namebuf;
759 minor_t minor;
760
761 namebuf = kmem_zalloc(strlen(name) + 2, KM_SLEEP);
762 (void) strncpy(namebuf, name, strlen(name));
763 (void) strcat(namebuf, "/");
764 mutex_enter(&zfsdev_state_lock);
765 for (minor = 1; minor <= ZFSDEV_MAX_MINOR; minor++) {
766
767 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
768 if (zv == NULL)
769 continue;
770 if (strncmp(namebuf, zv->zv_name, strlen(namebuf)) == 0)
771 (void) zvol_remove_zv(zv);
772 }
773 kmem_free(namebuf, strlen(name) + 2);
774
775 mutex_exit(&zfsdev_state_lock);
776 }
777
778 static int
779 zvol_update_live_volsize(zvol_state_t *zv, uint64_t volsize)
780 {
781 uint64_t old_volsize = 0ULL;
782 int error = 0;
783
784 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
785
786 /*
787 * Reinitialize the dump area to the new size. If we
788 * failed to resize the dump area then restore it back to
789 * its original size. We must set the new volsize prior
790 * to calling dumpvp_resize() to ensure that the devices'
791 * size(9P) is not visible by the dump subsystem.
792 */
793 old_volsize = zv->zv_volsize;
794 zvol_size_changed(zv, volsize);
795
796 if (zv->zv_flags & ZVOL_DUMPIFIED) {
797 if ((error = zvol_dumpify(zv)) != 0 ||
798 (error = dumpvp_resize()) != 0) {
799 int dumpify_error;
800
801 (void) zvol_update_volsize(zv->zv_objset, old_volsize);
802 zvol_size_changed(zv, old_volsize);
803 dumpify_error = zvol_dumpify(zv);
804 error = dumpify_error ? dumpify_error : error;
805 }
806 }
807
808 /*
809 * Generate a LUN expansion event.
810 */
811 if (error == 0) {
812 sysevent_id_t eid;
813 nvlist_t *attr;
814 char *physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
815
816 (void) snprintf(physpath, MAXPATHLEN, "%s%u", ZVOL_PSEUDO_DEV,
817 zv->zv_minor);
818
819 VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0);
820 VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0);
821
822 (void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS,
823 ESC_DEV_DLE, attr, &eid, DDI_SLEEP);
824
825 nvlist_free(attr);
826 kmem_free(physpath, MAXPATHLEN);
827 }
828 return (error);
829 }
830
831 int
832 zvol_set_volsize(const char *name, uint64_t volsize)
833 {
834 zvol_state_t *zv = NULL;
835 objset_t *os;
836 int error;
837 dmu_object_info_t doi;
838 uint64_t readonly;
839 boolean_t owned = B_FALSE;
840
841 error = dsl_prop_get_integer(name,
842 zfs_prop_to_name(ZFS_PROP_READONLY), &readonly, NULL);
843 if (error != 0)
844 return (error);
845 if (readonly)
846 return (SET_ERROR(EROFS));
847
848 mutex_enter(&zfsdev_state_lock);
849 zv = zvol_minor_lookup(name);
850
851 if (zv == NULL || zv->zv_objset == NULL) {
852 if ((error = dmu_objset_own(name, DMU_OST_ZVOL, B_FALSE,
853 FTAG, &os)) != 0) {
854 mutex_exit(&zfsdev_state_lock);
855 return (error);
856 }
857 owned = B_TRUE;
858 if (zv != NULL)
859 zv->zv_objset = os;
860 } else {
861 os = zv->zv_objset;
862 }
863
864 if ((error = dmu_object_info(os, ZVOL_OBJ, &doi)) != 0 ||
865 (error = zvol_check_volsize(volsize, doi.doi_data_block_size)) != 0)
866 goto out;
867
868 error = zvol_update_volsize(os, volsize);
869
870 if (error == 0 && zv != NULL)
871 error = zvol_update_live_volsize(zv, volsize);
872 out:
873 if (owned) {
874 dmu_objset_disown(os, FTAG);
875 if (zv != NULL)
876 zv->zv_objset = NULL;
877 }
878 mutex_exit(&zfsdev_state_lock);
879 return (error);
880 }
881
882 /*ARGSUSED*/
883 int
884 zvol_open(dev_t *devp, int flag, int otyp, cred_t *cr)
885 {
886 zvol_state_t *zv;
887 int err = 0;
888
889 mutex_enter(&zfsdev_state_lock);
890
891 zv = zfsdev_get_soft_state(getminor(*devp), ZSST_ZVOL);
892 if (zv == NULL) {
893 mutex_exit(&zfsdev_state_lock);
894 return (SET_ERROR(ENXIO));
895 }
896
897 if (zv->zv_total_opens == 0)
898 err = zvol_first_open(zv);
899 if (err) {
900 mutex_exit(&zfsdev_state_lock);
901 return (err);
902 }
903 if ((flag & FWRITE) && (zv->zv_flags & ZVOL_RDONLY)) {
904 err = SET_ERROR(EROFS);
905 goto out;
906 }
907 if (zv->zv_flags & ZVOL_EXCL) {
908 err = SET_ERROR(EBUSY);
909 goto out;
910 }
911 if (flag & FEXCL) {
912 if (zv->zv_total_opens != 0) {
913 err = SET_ERROR(EBUSY);
914 goto out;
915 }
916 zv->zv_flags |= ZVOL_EXCL;
917 }
918
919 if (zv->zv_open_count[otyp] == 0 || otyp == OTYP_LYR) {
920 zv->zv_open_count[otyp]++;
921 zv->zv_total_opens++;
922 }
923 mutex_exit(&zfsdev_state_lock);
924
925 return (err);
926 out:
927 if (zv->zv_total_opens == 0)
928 zvol_last_close(zv);
929 mutex_exit(&zfsdev_state_lock);
930 return (err);
931 }
932
933 /*ARGSUSED*/
934 int
935 zvol_close(dev_t dev, int flag, int otyp, cred_t *cr)
936 {
937 minor_t minor = getminor(dev);
938 zvol_state_t *zv;
939 int error = 0;
940
941 mutex_enter(&zfsdev_state_lock);
942
943 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
944 if (zv == NULL) {
945 mutex_exit(&zfsdev_state_lock);
946 return (SET_ERROR(ENXIO));
947 }
948
949 if (zv->zv_flags & ZVOL_EXCL) {
950 ASSERT(zv->zv_total_opens == 1);
951 zv->zv_flags &= ~ZVOL_EXCL;
952 }
953
954 /*
955 * If the open count is zero, this is a spurious close.
956 * That indicates a bug in the kernel / DDI framework.
957 */
958 ASSERT(zv->zv_open_count[otyp] != 0);
959 ASSERT(zv->zv_total_opens != 0);
960
961 /*
962 * You may get multiple opens, but only one close.
963 */
964 zv->zv_open_count[otyp]--;
965 zv->zv_total_opens--;
966
967 if (zv->zv_total_opens == 0)
968 zvol_last_close(zv);
969
970 mutex_exit(&zfsdev_state_lock);
971 return (error);
972 }
973
974 /* ARGSUSED */
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 rangelock_exit(zgd->zgd_lr);
982
983 kmem_free(zgd, sizeof (zgd_t));
984 }
985
986 /*
987 * Get data to generate a TX_WRITE intent log record.
988 */
989 static int
990 zvol_get_data(void *arg, lr_write_t *lr, char *buf, struct lwb *lwb, zio_t *zio)
991 {
992 zvol_state_t *zv = arg;
993 uint64_t offset = lr->lr_offset;
994 uint64_t size = lr->lr_length; /* length of user data */
995 dmu_buf_t *db;
996 zgd_t *zgd;
997 int error;
998
999 ASSERT3P(lwb, !=, NULL);
1000 ASSERT3P(zio, !=, NULL);
1001 ASSERT3U(size, !=, 0);
1002
1003 zgd = kmem_zalloc(sizeof (zgd_t), KM_SLEEP);
1004 zgd->zgd_lwb = lwb;
1005
1006 /*
1007 * Write records come in two flavors: immediate and indirect.
1008 * For small writes it's cheaper to store the data with the
1009 * log record (immediate); for large writes it's cheaper to
1010 * sync the data and get a pointer to it (indirect) so that
1011 * we don't have to write the data twice.
1012 */
1013 if (buf != NULL) { /* immediate write */
1014 zgd->zgd_lr = rangelock_enter(&zv->zv_rangelock, offset, size,
1015 RL_READER);
1016 error = dmu_read_by_dnode(zv->zv_dn, offset, size, buf,
1017 DMU_READ_NO_PREFETCH);
1018 } else { /* indirect write */
1019 /*
1020 * Have to lock the whole block to ensure when it's written out
1021 * and its checksum is being calculated that no one can change
1022 * the data. Contrarily to zfs_get_data we need not re-check
1023 * blocksize after we get the lock because it cannot be changed.
1024 */
1025 size = zv->zv_volblocksize;
1026 offset = P2ALIGN(offset, size);
1027 zgd->zgd_lr = rangelock_enter(&zv->zv_rangelock, offset, size,
1028 RL_READER);
1029 error = dmu_buf_hold_by_dnode(zv->zv_dn, offset, zgd, &db,
1030 DMU_READ_NO_PREFETCH);
1031 if (error == 0) {
1032 blkptr_t *bp = &lr->lr_blkptr;
1033
1034 zgd->zgd_db = db;
1035 zgd->zgd_bp = bp;
1036
1037 ASSERT(db->db_offset == offset);
1038 ASSERT(db->db_size == size);
1039
1040 error = dmu_sync(zio, lr->lr_common.lrc_txg,
1041 zvol_get_done, zgd);
1042
1043 if (error == 0)
1044 return (0);
1045 }
1046 }
1047
1048 zvol_get_done(zgd, error);
1049
1050 return (error);
1051 }
1052
1053 /*
1054 * zvol_log_write() handles synchronous writes using TX_WRITE ZIL transactions.
1055 *
1056 * We store data in the log buffers if it's small enough.
1057 * Otherwise we will later flush the data out via dmu_sync().
1058 */
1059 ssize_t zvol_immediate_write_sz = 32768;
1060
1061 static void
1062 zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, offset_t off, ssize_t resid,
1063 boolean_t sync)
1064 {
1065 uint32_t blocksize = zv->zv_volblocksize;
1066 zilog_t *zilog = zv->zv_zilog;
1067 itx_wr_state_t write_state;
1068
1069 if (zil_replaying(zilog, tx))
1070 return;
1071
1072 if (zilog->zl_logbias == ZFS_LOGBIAS_THROUGHPUT)
1073 write_state = WR_INDIRECT;
1074 else if (!spa_has_slogs(zilog->zl_spa) &&
1075 resid >= blocksize && blocksize > zvol_immediate_write_sz)
1076 write_state = WR_INDIRECT;
1077 else if (sync)
1078 write_state = WR_COPIED;
1079 else
1080 write_state = WR_NEED_COPY;
1081
1082 while (resid) {
1083 itx_t *itx;
1084 lr_write_t *lr;
1085 itx_wr_state_t wr_state = write_state;
1086 ssize_t len = resid;
1087
1088 if (wr_state == WR_COPIED && resid > ZIL_MAX_COPIED_DATA)
1089 wr_state = WR_NEED_COPY;
1090 else if (wr_state == WR_INDIRECT)
1091 len = MIN(blocksize - P2PHASE(off, blocksize), resid);
1092
1093 itx = zil_itx_create(TX_WRITE, sizeof (*lr) +
1094 (wr_state == WR_COPIED ? len : 0));
1095 lr = (lr_write_t *)&itx->itx_lr;
1096 if (wr_state == WR_COPIED && dmu_read_by_dnode(zv->zv_dn,
1097 off, len, lr + 1, DMU_READ_NO_PREFETCH) != 0) {
1098 zil_itx_destroy(itx);
1099 itx = zil_itx_create(TX_WRITE, sizeof (*lr));
1100 lr = (lr_write_t *)&itx->itx_lr;
1101 wr_state = WR_NEED_COPY;
1102 }
1103
1104 itx->itx_wr_state = wr_state;
1105 lr->lr_foid = ZVOL_OBJ;
1106 lr->lr_offset = off;
1107 lr->lr_length = len;
1108 lr->lr_blkoff = 0;
1109 BP_ZERO(&lr->lr_blkptr);
1110
1111 itx->itx_private = zv;
1112 itx->itx_sync = sync;
1113
1114 zil_itx_assign(zilog, itx, tx);
1115
1116 off += len;
1117 resid -= len;
1118 }
1119 }
1120
1121 static int
1122 zvol_dumpio_vdev(vdev_t *vd, void *addr, uint64_t offset, uint64_t origoffset,
1123 uint64_t size, boolean_t doread, boolean_t isdump)
1124 {
1125 vdev_disk_t *dvd;
1126 int c;
1127 int numerrors = 0;
1128
1129 if (vd->vdev_ops == &vdev_mirror_ops ||
1130 vd->vdev_ops == &vdev_replacing_ops ||
1131 vd->vdev_ops == &vdev_spare_ops) {
1132 for (c = 0; c < vd->vdev_children; c++) {
1133 int err = zvol_dumpio_vdev(vd->vdev_child[c],
1134 addr, offset, origoffset, size, doread, isdump);
1135 if (err != 0) {
1136 numerrors++;
1137 } else if (doread) {
1138 break;
1139 }
1140 }
1141 }
1142
1143 if (!vd->vdev_ops->vdev_op_leaf && vd->vdev_ops != &vdev_raidz_ops)
1144 return (numerrors < vd->vdev_children ? 0 : EIO);
1145
1146 if (doread && !vdev_readable(vd))
1147 return (SET_ERROR(EIO));
1148 else if (!doread && !vdev_writeable(vd))
1149 return (SET_ERROR(EIO));
1150
1151 if (vd->vdev_ops == &vdev_raidz_ops) {
1152 return (vdev_raidz_physio(vd,
1153 addr, size, offset, origoffset, doread, isdump));
1154 }
1155
1156 offset += VDEV_LABEL_START_SIZE;
1157
1158 if (ddi_in_panic() || isdump) {
1159 ASSERT(!doread);
1160 if (doread)
1161 return (SET_ERROR(EIO));
1162 dvd = vd->vdev_tsd;
1163 ASSERT3P(dvd, !=, NULL);
1164 return (ldi_dump(dvd->vd_lh, addr, lbtodb(offset),
1165 lbtodb(size)));
1166 } else {
1167 dvd = vd->vdev_tsd;
1168 ASSERT3P(dvd, !=, NULL);
1169 return (vdev_disk_ldi_physio(dvd->vd_lh, addr, size,
1170 offset, doread ? B_READ : B_WRITE));
1171 }
1172 }
1173
1174 static int
1175 zvol_dumpio(zvol_state_t *zv, void *addr, uint64_t offset, uint64_t size,
1176 boolean_t doread, boolean_t isdump)
1177 {
1178 vdev_t *vd;
1179 int error;
1180 zvol_extent_t *ze;
1181 spa_t *spa = dmu_objset_spa(zv->zv_objset);
1182
1183 /* Must be sector aligned, and not stradle a block boundary. */
1184 if (P2PHASE(offset, DEV_BSIZE) || P2PHASE(size, DEV_BSIZE) ||
1185 P2BOUNDARY(offset, size, zv->zv_volblocksize)) {
1186 return (SET_ERROR(EINVAL));
1187 }
1188 ASSERT(size <= zv->zv_volblocksize);
1189
1190 /* Locate the extent this belongs to */
1191 ze = list_head(&zv->zv_extents);
1192 while (offset >= ze->ze_nblks * zv->zv_volblocksize) {
1193 offset -= ze->ze_nblks * zv->zv_volblocksize;
1194 ze = list_next(&zv->zv_extents, ze);
1195 }
1196
1197 if (ze == NULL)
1198 return (SET_ERROR(EINVAL));
1199
1200 if (!ddi_in_panic())
1201 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
1202
1203 vd = vdev_lookup_top(spa, DVA_GET_VDEV(&ze->ze_dva));
1204 offset += DVA_GET_OFFSET(&ze->ze_dva);
1205 error = zvol_dumpio_vdev(vd, addr, offset, DVA_GET_OFFSET(&ze->ze_dva),
1206 size, doread, isdump);
1207
1208 if (!ddi_in_panic())
1209 spa_config_exit(spa, SCL_STATE, FTAG);
1210
1211 return (error);
1212 }
1213
1214 int
1215 zvol_strategy(buf_t *bp)
1216 {
1217 zfs_soft_state_t *zs = NULL;
1218 zvol_state_t *zv;
1219 uint64_t off, volsize;
1220 size_t resid;
1221 char *addr;
1222 objset_t *os;
1223 int error = 0;
1224 boolean_t doread = bp->b_flags & B_READ;
1225 boolean_t is_dumpified;
1226 boolean_t sync;
1227
1228 if (getminor(bp->b_edev) == 0) {
1229 error = SET_ERROR(EINVAL);
1230 } else {
1231 zs = ddi_get_soft_state(zfsdev_state, getminor(bp->b_edev));
1232 if (zs == NULL)
1233 error = SET_ERROR(ENXIO);
1234 else if (zs->zss_type != ZSST_ZVOL)
1235 error = SET_ERROR(EINVAL);
1236 }
1237
1238 if (error) {
1239 bioerror(bp, error);
1240 biodone(bp);
1241 return (0);
1242 }
1243
1244 zv = zs->zss_data;
1245
1246 if (!(bp->b_flags & B_READ) && (zv->zv_flags & ZVOL_RDONLY)) {
1247 bioerror(bp, EROFS);
1248 biodone(bp);
1249 return (0);
1250 }
1251
1252 off = ldbtob(bp->b_blkno);
1253 volsize = zv->zv_volsize;
1254
1255 os = zv->zv_objset;
1256 ASSERT(os != NULL);
1257
1258 bp_mapin(bp);
1259 addr = bp->b_un.b_addr;
1260 resid = bp->b_bcount;
1261
1262 if (resid > 0 && (off < 0 || off >= volsize)) {
1263 bioerror(bp, EIO);
1264 biodone(bp);
1265 return (0);
1266 }
1267
1268 is_dumpified = zv->zv_flags & ZVOL_DUMPIFIED;
1269 sync = ((!(bp->b_flags & B_ASYNC) &&
1270 !(zv->zv_flags & ZVOL_WCE)) ||
1271 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS)) &&
1272 !doread && !is_dumpified;
1273
1274 /*
1275 * There must be no buffer changes when doing a dmu_sync() because
1276 * we can't change the data whilst calculating the checksum.
1277 */
1278 locked_range_t *lr = rangelock_enter(&zv->zv_rangelock, off, resid,
1279 doread ? RL_READER : RL_WRITER);
1280
1281 while (resid != 0 && off < volsize) {
1282 size_t size = MIN(resid, zvol_maxphys);
1283 if (is_dumpified) {
1284 size = MIN(size, P2END(off, zv->zv_volblocksize) - off);
1285 error = zvol_dumpio(zv, addr, off, size,
1286 doread, B_FALSE);
1287 } else if (doread) {
1288 error = dmu_read(os, ZVOL_OBJ, off, size, addr,
1289 DMU_READ_PREFETCH);
1290 } else {
1291 dmu_tx_t *tx = dmu_tx_create(os);
1292 dmu_tx_hold_write(tx, ZVOL_OBJ, off, size);
1293 error = dmu_tx_assign(tx, TXG_WAIT);
1294 if (error) {
1295 dmu_tx_abort(tx);
1296 } else {
1297 dmu_write(os, ZVOL_OBJ, off, size, addr, tx);
1298 zvol_log_write(zv, tx, off, size, sync);
1299 dmu_tx_commit(tx);
1300 }
1301 }
1302 if (error) {
1303 /* convert checksum errors into IO errors */
1304 if (error == ECKSUM)
1305 error = SET_ERROR(EIO);
1306 break;
1307 }
1308 off += size;
1309 addr += size;
1310 resid -= size;
1311 }
1312 rangelock_exit(lr);
1313
1314 if ((bp->b_resid = resid) == bp->b_bcount)
1315 bioerror(bp, off > volsize ? EINVAL : error);
1316
1317 if (sync)
1318 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1319 biodone(bp);
1320
1321 return (0);
1322 }
1323
1324 /*
1325 * Set the buffer count to the zvol maximum transfer.
1326 * Using our own routine instead of the default minphys()
1327 * means that for larger writes we write bigger buffers on X86
1328 * (128K instead of 56K) and flush the disk write cache less often
1329 * (every zvol_maxphys - currently 1MB) instead of minphys (currently
1330 * 56K on X86 and 128K on sparc).
1331 */
1332 void
1333 zvol_minphys(struct buf *bp)
1334 {
1335 if (bp->b_bcount > zvol_maxphys)
1336 bp->b_bcount = zvol_maxphys;
1337 }
1338
1339 int
1340 zvol_dump(dev_t dev, caddr_t addr, daddr_t blkno, int nblocks)
1341 {
1342 minor_t minor = getminor(dev);
1343 zvol_state_t *zv;
1344 int error = 0;
1345 uint64_t size;
1346 uint64_t boff;
1347 uint64_t resid;
1348
1349 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1350 if (zv == NULL)
1351 return (SET_ERROR(ENXIO));
1352
1353 if ((zv->zv_flags & ZVOL_DUMPIFIED) == 0)
1354 return (SET_ERROR(EINVAL));
1355
1356 boff = ldbtob(blkno);
1357 resid = ldbtob(nblocks);
1358
1359 VERIFY3U(boff + resid, <=, zv->zv_volsize);
1360
1361 while (resid) {
1362 size = MIN(resid, P2END(boff, zv->zv_volblocksize) - boff);
1363 error = zvol_dumpio(zv, addr, boff, size, B_FALSE, B_TRUE);
1364 if (error)
1365 break;
1366 boff += size;
1367 addr += size;
1368 resid -= size;
1369 }
1370
1371 return (error);
1372 }
1373
1374 /*ARGSUSED*/
1375 int
1376 zvol_read(dev_t dev, uio_t *uio, cred_t *cr)
1377 {
1378 minor_t minor = getminor(dev);
1379 zvol_state_t *zv;
1380 uint64_t volsize;
1381 int error = 0;
1382
1383 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1384 if (zv == NULL)
1385 return (SET_ERROR(ENXIO));
1386
1387 volsize = zv->zv_volsize;
1388 if (uio->uio_resid > 0 &&
1389 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize))
1390 return (SET_ERROR(EIO));
1391
1392 if (zv->zv_flags & ZVOL_DUMPIFIED) {
1393 error = physio(zvol_strategy, NULL, dev, B_READ,
1394 zvol_minphys, uio);
1395 return (error);
1396 }
1397
1398 locked_range_t *lr = rangelock_enter(&zv->zv_rangelock,
1399 uio->uio_loffset, uio->uio_resid, RL_READER);
1400 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) {
1401 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1);
1402
1403 /* don't read past the end */
1404 if (bytes > volsize - uio->uio_loffset)
1405 bytes = volsize - uio->uio_loffset;
1406
1407 error = dmu_read_uio(zv->zv_objset, ZVOL_OBJ, uio, bytes);
1408 if (error) {
1409 /* convert checksum errors into IO errors */
1410 if (error == ECKSUM)
1411 error = SET_ERROR(EIO);
1412 break;
1413 }
1414 }
1415 rangelock_exit(lr);
1416
1417 return (error);
1418 }
1419
1420 /*ARGSUSED*/
1421 int
1422 zvol_write(dev_t dev, uio_t *uio, cred_t *cr)
1423 {
1424 minor_t minor = getminor(dev);
1425 zvol_state_t *zv;
1426 uint64_t volsize;
1427 int error = 0;
1428 boolean_t sync;
1429
1430 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1431 if (zv == NULL)
1432 return (SET_ERROR(ENXIO));
1433
1434 volsize = zv->zv_volsize;
1435 if (uio->uio_resid > 0 &&
1436 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize))
1437 return (SET_ERROR(EIO));
1438
1439 if (zv->zv_flags & ZVOL_DUMPIFIED) {
1440 error = physio(zvol_strategy, NULL, dev, B_WRITE,
1441 zvol_minphys, uio);
1442 return (error);
1443 }
1444
1445 sync = !(zv->zv_flags & ZVOL_WCE) ||
1446 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS);
1447
1448 locked_range_t *lr = rangelock_enter(&zv->zv_rangelock,
1449 uio->uio_loffset, uio->uio_resid, RL_WRITER);
1450 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) {
1451 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1);
1452 uint64_t off = uio->uio_loffset;
1453 dmu_tx_t *tx = dmu_tx_create(zv->zv_objset);
1454
1455 if (bytes > volsize - off) /* don't write past the end */
1456 bytes = volsize - off;
1457
1458 dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes);
1459 error = dmu_tx_assign(tx, TXG_WAIT);
1460 if (error) {
1461 dmu_tx_abort(tx);
1462 break;
1463 }
1464 error = dmu_write_uio_dnode(zv->zv_dn, uio, bytes, tx);
1465 if (error == 0)
1466 zvol_log_write(zv, tx, off, bytes, sync);
1467 dmu_tx_commit(tx);
1468
1469 if (error)
1470 break;
1471 }
1472 rangelock_exit(lr);
1473
1474 if (sync)
1475 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1476 return (error);
1477 }
1478
1479 int
1480 zvol_getefi(void *arg, int flag, uint64_t vs, uint8_t bs)
1481 {
1482 struct uuid uuid = EFI_RESERVED;
1483 efi_gpe_t gpe = { 0 };
1484 uint32_t crc;
1485 dk_efi_t efi;
1486 int length;
1487 char *ptr;
1488
1489 if (ddi_copyin(arg, &efi, sizeof (dk_efi_t), flag))
1490 return (SET_ERROR(EFAULT));
1491 ptr = (char *)(uintptr_t)efi.dki_data_64;
1492 length = efi.dki_length;
1493 /*
1494 * Some clients may attempt to request a PMBR for the
1495 * zvol. Currently this interface will return EINVAL to
1496 * such requests. These requests could be supported by
1497 * adding a check for lba == 0 and consing up an appropriate
1498 * PMBR.
1499 */
1500 if (efi.dki_lba < 1 || efi.dki_lba > 2 || length <= 0)
1501 return (SET_ERROR(EINVAL));
1502
1503 gpe.efi_gpe_StartingLBA = LE_64(34ULL);
1504 gpe.efi_gpe_EndingLBA = LE_64((vs >> bs) - 1);
1505 UUID_LE_CONVERT(gpe.efi_gpe_PartitionTypeGUID, uuid);
1506
1507 if (efi.dki_lba == 1) {
1508 efi_gpt_t gpt = { 0 };
1509
1510 gpt.efi_gpt_Signature = LE_64(EFI_SIGNATURE);
1511 gpt.efi_gpt_Revision = LE_32(EFI_VERSION_CURRENT);
1512 gpt.efi_gpt_HeaderSize = LE_32(sizeof (gpt));
1513 gpt.efi_gpt_MyLBA = LE_64(1ULL);
1514 gpt.efi_gpt_FirstUsableLBA = LE_64(34ULL);
1515 gpt.efi_gpt_LastUsableLBA = LE_64((vs >> bs) - 1);
1516 gpt.efi_gpt_PartitionEntryLBA = LE_64(2ULL);
1517 gpt.efi_gpt_NumberOfPartitionEntries = LE_32(1);
1518 gpt.efi_gpt_SizeOfPartitionEntry =
1519 LE_32(sizeof (efi_gpe_t));
1520 CRC32(crc, &gpe, sizeof (gpe), -1U, crc32_table);
1521 gpt.efi_gpt_PartitionEntryArrayCRC32 = LE_32(~crc);
1522 CRC32(crc, &gpt, sizeof (gpt), -1U, crc32_table);
1523 gpt.efi_gpt_HeaderCRC32 = LE_32(~crc);
1524 if (ddi_copyout(&gpt, ptr, MIN(sizeof (gpt), length),
1525 flag))
1526 return (SET_ERROR(EFAULT));
1527 ptr += sizeof (gpt);
1528 length -= sizeof (gpt);
1529 }
1530 if (length > 0 && ddi_copyout(&gpe, ptr, MIN(sizeof (gpe),
1531 length), flag))
1532 return (SET_ERROR(EFAULT));
1533 return (0);
1534 }
1535
1536 /*
1537 * BEGIN entry points to allow external callers access to the volume.
1538 */
1539 /*
1540 * Return the volume parameters needed for access from an external caller.
1541 * These values are invariant as long as the volume is held open.
1542 */
1543 int
1544 zvol_get_volume_params(minor_t minor, uint64_t *blksize,
1545 uint64_t *max_xfer_len, void **minor_hdl, void **objset_hdl, void **zil_hdl,
1546 void **rl_hdl, void **dnode_hdl)
1547 {
1548 zvol_state_t *zv;
1549
1550 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1551 if (zv == NULL)
1552 return (SET_ERROR(ENXIO));
1553 if (zv->zv_flags & ZVOL_DUMPIFIED)
1554 return (SET_ERROR(ENXIO));
1555
1556 ASSERT(blksize && max_xfer_len && minor_hdl &&
1557 objset_hdl && zil_hdl && rl_hdl && dnode_hdl);
1558
1559 *blksize = zv->zv_volblocksize;
1560 *max_xfer_len = (uint64_t)zvol_maxphys;
1561 *minor_hdl = zv;
1562 *objset_hdl = zv->zv_objset;
1563 *zil_hdl = zv->zv_zilog;
1564 *rl_hdl = &zv->zv_rangelock;
1565 *dnode_hdl = zv->zv_dn;
1566 return (0);
1567 }
1568
1569 /*
1570 * Return the current volume size to an external caller.
1571 * The size can change while the volume is open.
1572 */
1573 uint64_t
1574 zvol_get_volume_size(void *minor_hdl)
1575 {
1576 zvol_state_t *zv = minor_hdl;
1577
1578 return (zv->zv_volsize);
1579 }
1580
1581 /*
1582 * Return the current WCE setting to an external caller.
1583 * The WCE setting can change while the volume is open.
1584 */
1585 int
1586 zvol_get_volume_wce(void *minor_hdl)
1587 {
1588 zvol_state_t *zv = minor_hdl;
1589
1590 return ((zv->zv_flags & ZVOL_WCE) ? 1 : 0);
1591 }
1592
1593 /*
1594 * Entry point for external callers to zvol_log_write
1595 */
1596 void
1597 zvol_log_write_minor(void *minor_hdl, dmu_tx_t *tx, offset_t off, ssize_t resid,
1598 boolean_t sync)
1599 {
1600 zvol_state_t *zv = minor_hdl;
1601
1602 zvol_log_write(zv, tx, off, resid, sync);
1603 }
1604 /*
1605 * END entry points to allow external callers access to the volume.
1606 */
1607
1608 /*
1609 * Log a DKIOCFREE/free-long-range to the ZIL with TX_TRUNCATE.
1610 */
1611 static void
1612 zvol_log_truncate(zvol_state_t *zv, dmu_tx_t *tx, uint64_t off, uint64_t len,
1613 boolean_t sync)
1614 {
1615 itx_t *itx;
1616 lr_truncate_t *lr;
1617 zilog_t *zilog = zv->zv_zilog;
1618
1619 if (zil_replaying(zilog, tx))
1620 return;
1621
1622 itx = zil_itx_create(TX_TRUNCATE, sizeof (*lr));
1623 lr = (lr_truncate_t *)&itx->itx_lr;
1624 lr->lr_foid = ZVOL_OBJ;
1625 lr->lr_offset = off;
1626 lr->lr_length = len;
1627
1628 itx->itx_sync = sync;
1629 zil_itx_assign(zilog, itx, tx);
1630 }
1631
1632 /*
1633 * Dirtbag ioctls to support mkfs(1M) for UFS filesystems. See dkio(7I).
1634 * Also a dirtbag dkio ioctl for unmap/free-block functionality.
1635 */
1636 /*ARGSUSED*/
1637 int
1638 zvol_ioctl(dev_t dev, int cmd, intptr_t arg, int flag, cred_t *cr, int *rvalp)
1639 {
1640 zvol_state_t *zv;
1641 struct dk_callback *dkc;
1642 int error = 0;
1643 locked_range_t *lr;
1644
1645 mutex_enter(&zfsdev_state_lock);
1646
1647 zv = zfsdev_get_soft_state(getminor(dev), ZSST_ZVOL);
1648
1649 if (zv == NULL) {
1650 mutex_exit(&zfsdev_state_lock);
1651 return (SET_ERROR(ENXIO));
1652 }
1653 ASSERT(zv->zv_total_opens > 0);
1654
1655 switch (cmd) {
1656
1657 case DKIOCINFO:
1658 {
1659 struct dk_cinfo dki;
1660
1661 bzero(&dki, sizeof (dki));
1662 (void) strcpy(dki.dki_cname, "zvol");
1663 (void) strcpy(dki.dki_dname, "zvol");
1664 dki.dki_ctype = DKC_UNKNOWN;
1665 dki.dki_unit = getminor(dev);
1666 dki.dki_maxtransfer =
1667 1 << (SPA_OLD_MAXBLOCKSHIFT - zv->zv_min_bs);
1668 mutex_exit(&zfsdev_state_lock);
1669 if (ddi_copyout(&dki, (void *)arg, sizeof (dki), flag))
1670 error = SET_ERROR(EFAULT);
1671 return (error);
1672 }
1673
1674 case DKIOCGMEDIAINFO:
1675 {
1676 struct dk_minfo dkm;
1677
1678 bzero(&dkm, sizeof (dkm));
1679 dkm.dki_lbsize = 1U << zv->zv_min_bs;
1680 dkm.dki_capacity = zv->zv_volsize >> zv->zv_min_bs;
1681 dkm.dki_media_type = DK_UNKNOWN;
1682 mutex_exit(&zfsdev_state_lock);
1683 if (ddi_copyout(&dkm, (void *)arg, sizeof (dkm), flag))
1684 error = SET_ERROR(EFAULT);
1685 return (error);
1686 }
1687
1688 case DKIOCGMEDIAINFOEXT:
1689 {
1690 struct dk_minfo_ext dkmext;
1691
1692 bzero(&dkmext, sizeof (dkmext));
1693 dkmext.dki_lbsize = 1U << zv->zv_min_bs;
1694 dkmext.dki_pbsize = zv->zv_volblocksize;
1695 dkmext.dki_capacity = zv->zv_volsize >> zv->zv_min_bs;
1696 dkmext.dki_media_type = DK_UNKNOWN;
1697 mutex_exit(&zfsdev_state_lock);
1698 if (ddi_copyout(&dkmext, (void *)arg, sizeof (dkmext), flag))
1699 error = SET_ERROR(EFAULT);
1700 return (error);
1701 }
1702
1703 case DKIOCGETEFI:
1704 {
1705 uint64_t vs = zv->zv_volsize;
1706 uint8_t bs = zv->zv_min_bs;
1707
1708 mutex_exit(&zfsdev_state_lock);
1709 error = zvol_getefi((void *)arg, flag, vs, bs);
1710 return (error);
1711 }
1712
1713 case DKIOCFLUSHWRITECACHE:
1714 dkc = (struct dk_callback *)arg;
1715 mutex_exit(&zfsdev_state_lock);
1716 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1717 if ((flag & FKIOCTL) && dkc != NULL && dkc->dkc_callback) {
1718 (*dkc->dkc_callback)(dkc->dkc_cookie, error);
1719 error = 0;
1720 }
1721 return (error);
1722
1723 case DKIOCGETWCE:
1724 {
1725 int wce = (zv->zv_flags & ZVOL_WCE) ? 1 : 0;
1726 if (ddi_copyout(&wce, (void *)arg, sizeof (int),
1727 flag))
1728 error = SET_ERROR(EFAULT);
1729 break;
1730 }
1731 case DKIOCSETWCE:
1732 {
1733 int wce;
1734 if (ddi_copyin((void *)arg, &wce, sizeof (int),
1735 flag)) {
1736 error = SET_ERROR(EFAULT);
1737 break;
1738 }
1739 if (wce) {
1740 zv->zv_flags |= ZVOL_WCE;
1741 mutex_exit(&zfsdev_state_lock);
1742 } else {
1743 zv->zv_flags &= ~ZVOL_WCE;
1744 mutex_exit(&zfsdev_state_lock);
1745 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1746 }
1747 return (0);
1748 }
1749
1750 case DKIOCGGEOM:
1751 case DKIOCGVTOC:
1752 /*
1753 * commands using these (like prtvtoc) expect ENOTSUP
1754 * since we're emulating an EFI label
1755 */
1756 error = SET_ERROR(ENOTSUP);
1757 break;
1758
1759 case DKIOCDUMPINIT:
1760 lr = rangelock_enter(&zv->zv_rangelock, 0, zv->zv_volsize,
1761 RL_WRITER);
1762 error = zvol_dumpify(zv);
1763 rangelock_exit(lr);
1764 break;
1765
1766 case DKIOCDUMPFINI:
1767 if (!(zv->zv_flags & ZVOL_DUMPIFIED))
1768 break;
1769 lr = rangelock_enter(&zv->zv_rangelock, 0, zv->zv_volsize,
1770 RL_WRITER);
1771 error = zvol_dump_fini(zv);
1772 rangelock_exit(lr);
1773 break;
1774
1775 case DKIOCFREE:
1776 {
1777 dkioc_free_list_t *dfl;
1778 dmu_tx_t *tx;
1779
1780 if (!zvol_unmap_enabled)
1781 break;
1782
1783 if (!(flag & FKIOCTL)) {
1784 error = dfl_copyin((void *)arg, &dfl, flag, KM_SLEEP);
1785 if (error != 0)
1786 break;
1787 } else {
1788 dfl = (dkioc_free_list_t *)arg;
1789 ASSERT3U(dfl->dfl_num_exts, <=, DFL_COPYIN_MAX_EXTS);
1790 if (dfl->dfl_num_exts > DFL_COPYIN_MAX_EXTS) {
1791 error = SET_ERROR(EINVAL);
1792 break;
1793 }
1794 }
1795
1796 mutex_exit(&zfsdev_state_lock);
1797
1798 for (int i = 0; i < dfl->dfl_num_exts; i++) {
1799 uint64_t start = dfl->dfl_exts[i].dfle_start,
1800 length = dfl->dfl_exts[i].dfle_length,
1801 end = start + length;
1802
1803 /*
1804 * Apply Postel's Law to length-checking. If they
1805 * overshoot, just blank out until the end, if there's
1806 * a need to blank out anything.
1807 */
1808 if (start >= zv->zv_volsize)
1809 continue; /* No need to do anything... */
1810 if (end > zv->zv_volsize) {
1811 end = DMU_OBJECT_END;
1812 length = end - start;
1813 }
1814
1815 lr = rangelock_enter(&zv->zv_rangelock, start, length,
1816 RL_WRITER);
1817 tx = dmu_tx_create(zv->zv_objset);
1818 error = dmu_tx_assign(tx, TXG_WAIT);
1819 if (error != 0) {
1820 dmu_tx_abort(tx);
1821 } else {
1822 zvol_log_truncate(zv, tx, start, length,
1823 B_TRUE);
1824 dmu_tx_commit(tx);
1825 error = dmu_free_long_range(zv->zv_objset,
1826 ZVOL_OBJ, start, length);
1827 }
1828
1829 rangelock_exit(lr);
1830
1831 if (error != 0)
1832 break;
1833 }
1834
1835 /*
1836 * If the write-cache is disabled, 'sync' property
1837 * is set to 'always', or if the caller is asking for
1838 * a synchronous free, commit this operation to the zil.
1839 * This will sync any previous uncommitted writes to the
1840 * zvol object.
1841 * Can be overridden by the zvol_unmap_sync_enabled tunable.
1842 */
1843 if ((error == 0) && zvol_unmap_sync_enabled &&
1844 (!(zv->zv_flags & ZVOL_WCE) ||
1845 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS) ||
1846 (dfl->dfl_flags & DF_WAIT_SYNC))) {
1847 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1848 }
1849
1850 if (!(flag & FKIOCTL))
1851 dfl_free(dfl);
1852
1853 return (error);
1854 }
1855
1856 default:
1857 error = SET_ERROR(ENOTTY);
1858 break;
1859
1860 }
1861 mutex_exit(&zfsdev_state_lock);
1862 return (error);
1863 }
1864
1865 int
1866 zvol_busy(void)
1867 {
1868 return (zvol_minors != 0);
1869 }
1870
1871 void
1872 zvol_init(void)
1873 {
1874 VERIFY(ddi_soft_state_init(&zfsdev_state, sizeof (zfs_soft_state_t),
1875 1) == 0);
1876 mutex_init(&zfsdev_state_lock, NULL, MUTEX_DEFAULT, NULL);
1877 }
1878
1879 void
1880 zvol_fini(void)
1881 {
1882 mutex_destroy(&zfsdev_state_lock);
1883 ddi_soft_state_fini(&zfsdev_state);
1884 }
1885
1886 /*ARGSUSED*/
1887 static int
1888 zfs_mvdev_dump_feature_check(void *arg, dmu_tx_t *tx)
1889 {
1890 spa_t *spa = dmu_tx_pool(tx)->dp_spa;
1891
1892 if (spa_feature_is_active(spa, SPA_FEATURE_MULTI_VDEV_CRASH_DUMP))
1893 return (1);
1894 return (0);
1895 }
1896
1897 /*ARGSUSED*/
1898 static void
1899 zfs_mvdev_dump_activate_feature_sync(void *arg, dmu_tx_t *tx)
1900 {
1901 spa_t *spa = dmu_tx_pool(tx)->dp_spa;
1902
1903 spa_feature_incr(spa, SPA_FEATURE_MULTI_VDEV_CRASH_DUMP, tx);
1904 }
1905
1906 static int
1907 zvol_dump_init(zvol_state_t *zv, boolean_t resize)
1908 {
1909 dmu_tx_t *tx;
1910 int error;
1911 objset_t *os = zv->zv_objset;
1912 spa_t *spa = dmu_objset_spa(os);
1913 vdev_t *vd = spa->spa_root_vdev;
1914 nvlist_t *nv = NULL;
1915 uint64_t version = spa_version(spa);
1916 uint64_t checksum, compress, refresrv, vbs, dedup;
1917
1918 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
1919 ASSERT(vd->vdev_ops == &vdev_root_ops);
1920
1921 error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, 0,
1922 DMU_OBJECT_END);
1923 if (error != 0)
1924 return (error);
1925 /* wait for dmu_free_long_range to actually free the blocks */
1926 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
1927
1928 /*
1929 * If the pool on which the dump device is being initialized has more
1930 * than one child vdev, check that the MULTI_VDEV_CRASH_DUMP feature is
1931 * enabled. If so, bump that feature's counter to indicate that the
1932 * feature is active. We also check the vdev type to handle the
1933 * following case:
1934 * # zpool create test raidz disk1 disk2 disk3
1935 * Now have spa_root_vdev->vdev_children == 1 (the raidz vdev),
1936 * the raidz vdev itself has 3 children.
1937 */
1938 if (vd->vdev_children > 1 || vd->vdev_ops == &vdev_raidz_ops) {
1939 if (!spa_feature_is_enabled(spa,
1940 SPA_FEATURE_MULTI_VDEV_CRASH_DUMP))
1941 return (SET_ERROR(ENOTSUP));
1942 (void) dsl_sync_task(spa_name(spa),
1943 zfs_mvdev_dump_feature_check,
1944 zfs_mvdev_dump_activate_feature_sync, NULL,
1945 2, ZFS_SPACE_CHECK_RESERVED);
1946 }
1947
1948 if (!resize) {
1949 error = dsl_prop_get_integer(zv->zv_name,
1950 zfs_prop_to_name(ZFS_PROP_COMPRESSION), &compress, NULL);
1951 if (error == 0) {
1952 error = dsl_prop_get_integer(zv->zv_name,
1953 zfs_prop_to_name(ZFS_PROP_CHECKSUM), &checksum,
1954 NULL);
1955 }
1956 if (error == 0) {
1957 error = dsl_prop_get_integer(zv->zv_name,
1958 zfs_prop_to_name(ZFS_PROP_REFRESERVATION),
1959 &refresrv, NULL);
1960 }
1961 if (error == 0) {
1962 error = dsl_prop_get_integer(zv->zv_name,
1963 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &vbs,
1964 NULL);
1965 }
1966 if (version >= SPA_VERSION_DEDUP && error == 0) {
1967 error = dsl_prop_get_integer(zv->zv_name,
1968 zfs_prop_to_name(ZFS_PROP_DEDUP), &dedup, NULL);
1969 }
1970 }
1971 if (error != 0)
1972 return (error);
1973
1974 tx = dmu_tx_create(os);
1975 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
1976 dmu_tx_hold_bonus(tx, ZVOL_OBJ);
1977 error = dmu_tx_assign(tx, TXG_WAIT);
1978 if (error != 0) {
1979 dmu_tx_abort(tx);
1980 return (error);
1981 }
1982
1983 /*
1984 * If we are resizing the dump device then we only need to
1985 * update the refreservation to match the newly updated
1986 * zvolsize. Otherwise, we save off the original state of the
1987 * zvol so that we can restore them if the zvol is ever undumpified.
1988 */
1989 if (resize) {
1990 error = zap_update(os, ZVOL_ZAP_OBJ,
1991 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1,
1992 &zv->zv_volsize, tx);
1993 } else {
1994 error = zap_update(os, ZVOL_ZAP_OBJ,
1995 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1,
1996 &compress, tx);
1997 if (error == 0) {
1998 error = zap_update(os, ZVOL_ZAP_OBJ,
1999 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1,
2000 &checksum, tx);
2001 }
2002 if (error == 0) {
2003 error = zap_update(os, ZVOL_ZAP_OBJ,
2004 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1,
2005 &refresrv, tx);
2006 }
2007 if (error == 0) {
2008 error = zap_update(os, ZVOL_ZAP_OBJ,
2009 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1,
2010 &vbs, tx);
2011 }
2012 if (error == 0) {
2013 error = dmu_object_set_blocksize(
2014 os, ZVOL_OBJ, SPA_OLD_MAXBLOCKSIZE, 0, tx);
2015 }
2016 if (version >= SPA_VERSION_DEDUP && error == 0) {
2017 error = zap_update(os, ZVOL_ZAP_OBJ,
2018 zfs_prop_to_name(ZFS_PROP_DEDUP), 8, 1,
2019 &dedup, tx);
2020 }
2021 if (error == 0)
2022 zv->zv_volblocksize = SPA_OLD_MAXBLOCKSIZE;
2023 }
2024 dmu_tx_commit(tx);
2025
2026 /*
2027 * We only need update the zvol's property if we are initializing
2028 * the dump area for the first time.
2029 */
2030 if (error == 0 && !resize) {
2031 /*
2032 * If MULTI_VDEV_CRASH_DUMP is active, use the NOPARITY checksum
2033 * function. Otherwise, use the old default -- OFF.
2034 */
2035 checksum = spa_feature_is_active(spa,
2036 SPA_FEATURE_MULTI_VDEV_CRASH_DUMP) ? ZIO_CHECKSUM_NOPARITY :
2037 ZIO_CHECKSUM_OFF;
2038
2039 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2040 VERIFY(nvlist_add_uint64(nv,
2041 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 0) == 0);
2042 VERIFY(nvlist_add_uint64(nv,
2043 zfs_prop_to_name(ZFS_PROP_COMPRESSION),
2044 ZIO_COMPRESS_OFF) == 0);
2045 VERIFY(nvlist_add_uint64(nv,
2046 zfs_prop_to_name(ZFS_PROP_CHECKSUM),
2047 checksum) == 0);
2048 if (version >= SPA_VERSION_DEDUP) {
2049 VERIFY(nvlist_add_uint64(nv,
2050 zfs_prop_to_name(ZFS_PROP_DEDUP),
2051 ZIO_CHECKSUM_OFF) == 0);
2052 }
2053
2054 error = zfs_set_prop_nvlist(zv->zv_name, ZPROP_SRC_LOCAL,
2055 nv, NULL);
2056 nvlist_free(nv);
2057 }
2058
2059 /* Allocate the space for the dump */
2060 if (error == 0)
2061 error = zvol_prealloc(zv);
2062 return (error);
2063 }
2064
2065 static int
2066 zvol_dumpify(zvol_state_t *zv)
2067 {
2068 int error = 0;
2069 uint64_t dumpsize = 0;
2070 dmu_tx_t *tx;
2071 objset_t *os = zv->zv_objset;
2072
2073 if (zv->zv_flags & ZVOL_RDONLY)
2074 return (SET_ERROR(EROFS));
2075
2076 if (zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE,
2077 8, 1, &dumpsize) != 0 || dumpsize != zv->zv_volsize) {
2078 boolean_t resize = (dumpsize > 0);
2079
2080 if ((error = zvol_dump_init(zv, resize)) != 0) {
2081 (void) zvol_dump_fini(zv);
2082 return (error);
2083 }
2084 }
2085
2086 /*
2087 * Build up our lba mapping.
2088 */
2089 error = zvol_get_lbas(zv);
2090 if (error) {
2091 (void) zvol_dump_fini(zv);
2092 return (error);
2093 }
2094
2095 tx = dmu_tx_create(os);
2096 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
2097 error = dmu_tx_assign(tx, TXG_WAIT);
2098 if (error) {
2099 dmu_tx_abort(tx);
2100 (void) zvol_dump_fini(zv);
2101 return (error);
2102 }
2103
2104 zv->zv_flags |= ZVOL_DUMPIFIED;
2105 error = zap_update(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, 8, 1,
2106 &zv->zv_volsize, tx);
2107 dmu_tx_commit(tx);
2108
2109 if (error) {
2110 (void) zvol_dump_fini(zv);
2111 return (error);
2112 }
2113
2114 txg_wait_synced(dmu_objset_pool(os), 0);
2115 return (0);
2116 }
2117
2118 static int
2119 zvol_dump_fini(zvol_state_t *zv)
2120 {
2121 dmu_tx_t *tx;
2122 objset_t *os = zv->zv_objset;
2123 nvlist_t *nv;
2124 int error = 0;
2125 uint64_t checksum, compress, refresrv, vbs, dedup;
2126 uint64_t version = spa_version(dmu_objset_spa(zv->zv_objset));
2127
2128 /*
2129 * Attempt to restore the zvol back to its pre-dumpified state.
2130 * This is a best-effort attempt as it's possible that not all
2131 * of these properties were initialized during the dumpify process
2132 * (i.e. error during zvol_dump_init).
2133 */
2134
2135 tx = dmu_tx_create(os);
2136 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
2137 error = dmu_tx_assign(tx, TXG_WAIT);
2138 if (error) {
2139 dmu_tx_abort(tx);
2140 return (error);
2141 }
2142 (void) zap_remove(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, tx);
2143 dmu_tx_commit(tx);
2144
2145 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2146 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1, &checksum);
2147 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2148 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1, &compress);
2149 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2150 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, &refresrv);
2151 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2152 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1, &vbs);
2153
2154 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2155 (void) nvlist_add_uint64(nv,
2156 zfs_prop_to_name(ZFS_PROP_CHECKSUM), checksum);
2157 (void) nvlist_add_uint64(nv,
2158 zfs_prop_to_name(ZFS_PROP_COMPRESSION), compress);
2159 (void) nvlist_add_uint64(nv,
2160 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), refresrv);
2161 if (version >= SPA_VERSION_DEDUP &&
2162 zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2163 zfs_prop_to_name(ZFS_PROP_DEDUP), 8, 1, &dedup) == 0) {
2164 (void) nvlist_add_uint64(nv,
2165 zfs_prop_to_name(ZFS_PROP_DEDUP), dedup);
2166 }
2167 (void) zfs_set_prop_nvlist(zv->zv_name, ZPROP_SRC_LOCAL,
2168 nv, NULL);
2169 nvlist_free(nv);
2170
2171 zvol_free_extents(zv);
2172 zv->zv_flags &= ~ZVOL_DUMPIFIED;
2173 (void) dmu_free_long_range(os, ZVOL_OBJ, 0, DMU_OBJECT_END);
2174 /* wait for dmu_free_long_range to actually free the blocks */
2175 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
2176 tx = dmu_tx_create(os);
2177 dmu_tx_hold_bonus(tx, ZVOL_OBJ);
2178 error = dmu_tx_assign(tx, TXG_WAIT);
2179 if (error) {
2180 dmu_tx_abort(tx);
2181 return (error);
2182 }
2183 if (dmu_object_set_blocksize(os, ZVOL_OBJ, vbs, 0, tx) == 0)
2184 zv->zv_volblocksize = vbs;
2185 dmu_tx_commit(tx);
2186
2187 return (0);
2188 }