1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 *
24 * Portions Copyright 2010 Robert Milkowski
25 *
26 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
27 * Copyright (c) 2013 by Delphix. All rights reserved.
28 * Copyright (c) 2013, Joyent, Inc. All rights reserved.
29 */
30
31 /*
32 * ZFS volume emulation driver.
33 *
34 * Makes a DMU object look like a volume of arbitrary size, up to 2^64 bytes.
35 * Volumes are accessed through the symbolic links named:
36 *
37 * /dev/zvol/dsk/<pool_name>/<dataset_name>
38 * /dev/zvol/rdsk/<pool_name>/<dataset_name>
39 *
40 * These links are created by the /dev filesystem (sdev_zvolops.c).
41 * Volumes are persistent through reboot. No user command needs to be
42 * run before opening and using a device.
43 */
44
45 #include <sys/types.h>
46 #include <sys/param.h>
47 #include <sys/errno.h>
48 #include <sys/uio.h>
49 #include <sys/buf.h>
50 #include <sys/modctl.h>
51 #include <sys/open.h>
52 #include <sys/kmem.h>
53 #include <sys/conf.h>
54 #include <sys/cmn_err.h>
55 #include <sys/stat.h>
56 #include <sys/zap.h>
57 #include <sys/spa.h>
58 #include <sys/spa_impl.h>
59 #include <sys/zio.h>
60 #include <sys/dmu_traverse.h>
61 #include <sys/dnode.h>
62 #include <sys/dsl_dataset.h>
63 #include <sys/dsl_prop.h>
64 #include <sys/dkio.h>
65 #include <sys/efi_partition.h>
66 #include <sys/byteorder.h>
67 #include <sys/pathname.h>
68 #include <sys/ddi.h>
69 #include <sys/sunddi.h>
70 #include <sys/crc32.h>
71 #include <sys/dirent.h>
72 #include <sys/policy.h>
73 #include <sys/fs/zfs.h>
74 #include <sys/zfs_ioctl.h>
75 #include <sys/mkdev.h>
76 #include <sys/zil.h>
77 #include <sys/refcount.h>
78 #include <sys/zfs_znode.h>
79 #include <sys/zfs_rlock.h>
80 #include <sys/vdev_disk.h>
81 #include <sys/vdev_impl.h>
82 #include <sys/vdev_raidz.h>
83 #include <sys/zvol.h>
84 #include <sys/dumphdr.h>
85 #include <sys/zil_impl.h>
86 #include <sys/dbuf.h>
87 #include <sys/dmu_tx.h>
88 #include <sys/zfeature.h>
89 #include <sys/zio_checksum.h>
90
91 #include "zfs_namecheck.h"
92
93 void *zfsdev_state;
94 static char *zvol_tag = "zvol_tag";
95
96 #define ZVOL_DUMPSIZE "dumpsize"
97
98 /*
99 * This lock protects the zfsdev_state structure from being modified
100 * while it's being used, e.g. an open that comes in before a create
101 * finishes. It also protects temporary opens of the dataset so that,
102 * e.g., an open doesn't get a spurious EBUSY.
103 */
104 kmutex_t zfsdev_state_lock;
105 static uint32_t zvol_minors;
106
107 typedef struct zvol_extent {
108 list_node_t ze_node;
109 dva_t ze_dva; /* dva associated with this extent */
110 uint64_t ze_nblks; /* number of blocks in extent */
111 } zvol_extent_t;
112
113 /*
114 * The in-core state of each volume.
115 */
116 typedef struct zvol_state {
117 char zv_name[MAXPATHLEN]; /* pool/dd name */
118 uint64_t zv_volsize; /* amount of space we advertise */
119 uint64_t zv_volblocksize; /* volume block size */
120 minor_t zv_minor; /* minor number */
121 uint8_t zv_min_bs; /* minimum addressable block shift */
122 uint8_t zv_flags; /* readonly, dumpified, etc. */
123 objset_t *zv_objset; /* objset handle */
124 uint32_t zv_open_count[OTYPCNT]; /* open counts */
125 uint32_t zv_total_opens; /* total open count */
126 zilog_t *zv_zilog; /* ZIL handle */
127 list_t zv_extents; /* List of extents for dump */
128 znode_t zv_znode; /* for range locking */
129 dmu_buf_t *zv_dbuf; /* bonus handle */
130 } zvol_state_t;
131
132 /*
133 * zvol specific flags
134 */
135 #define ZVOL_RDONLY 0x1
136 #define ZVOL_DUMPIFIED 0x2
137 #define ZVOL_EXCL 0x4
138 #define ZVOL_WCE 0x8
139
140 /*
141 * zvol maximum transfer in one DMU tx.
142 */
143 int zvol_maxphys = DMU_MAX_ACCESS/2;
144
145 extern int zfs_set_prop_nvlist(const char *, zprop_source_t,
146 nvlist_t *, nvlist_t *);
147 static int zvol_remove_zv(zvol_state_t *);
148 static int zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio);
149 static int zvol_dumpify(zvol_state_t *zv);
150 static int zvol_dump_fini(zvol_state_t *zv);
151 static int zvol_dump_init(zvol_state_t *zv, boolean_t resize);
152
153 static void
154 zvol_size_changed(zvol_state_t *zv, uint64_t volsize)
155 {
156 dev_t dev = makedevice(ddi_driver_major(zfs_dip), zv->zv_minor);
157
158 zv->zv_volsize = volsize;
159 VERIFY(ddi_prop_update_int64(dev, zfs_dip,
160 "Size", volsize) == DDI_SUCCESS);
161 VERIFY(ddi_prop_update_int64(dev, zfs_dip,
162 "Nblocks", lbtodb(volsize)) == DDI_SUCCESS);
163
164 /* Notify specfs to invalidate the cached size */
165 spec_size_invalidate(dev, VBLK);
166 spec_size_invalidate(dev, VCHR);
167 }
168
169 int
170 zvol_check_volsize(uint64_t volsize, uint64_t blocksize)
171 {
172 if (volsize == 0)
173 return (SET_ERROR(EINVAL));
174
175 if (volsize % blocksize != 0)
176 return (SET_ERROR(EINVAL));
177
178 #ifdef _ILP32
179 if (volsize - 1 > SPEC_MAXOFFSET_T)
180 return (SET_ERROR(EOVERFLOW));
181 #endif
182 return (0);
183 }
184
185 int
186 zvol_check_volblocksize(uint64_t volblocksize)
187 {
188 if (volblocksize < SPA_MINBLOCKSIZE ||
189 volblocksize > SPA_MAXBLOCKSIZE ||
190 !ISP2(volblocksize))
191 return (SET_ERROR(EDOM));
192
193 return (0);
194 }
195
196 int
197 zvol_get_stats(objset_t *os, nvlist_t *nv)
198 {
199 int error;
200 dmu_object_info_t doi;
201 uint64_t val;
202
203 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &val);
204 if (error)
205 return (error);
206
207 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLSIZE, val);
208
209 error = dmu_object_info(os, ZVOL_OBJ, &doi);
210
211 if (error == 0) {
212 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLBLOCKSIZE,
213 doi.doi_data_block_size);
214 }
215
216 return (error);
217 }
218
219 static zvol_state_t *
220 zvol_minor_lookup(const char *name)
221 {
222 minor_t minor;
223 zvol_state_t *zv;
224
225 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
226
227 for (minor = 1; minor <= ZFSDEV_MAX_MINOR; minor++) {
228 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
229 if (zv == NULL)
230 continue;
231 if (strcmp(zv->zv_name, name) == 0)
232 return (zv);
233 }
234
235 return (NULL);
236 }
237
238 /* extent mapping arg */
239 struct maparg {
240 zvol_state_t *ma_zv;
241 uint64_t ma_blks;
242 };
243
244 /*ARGSUSED*/
245 static int
246 zvol_map_block(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
247 const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
248 {
249 struct maparg *ma = arg;
250 zvol_extent_t *ze;
251 int bs = ma->ma_zv->zv_volblocksize;
252
253 if (bp == NULL || zb->zb_object != ZVOL_OBJ || zb->zb_level != 0)
254 return (0);
255
256 VERIFY3U(ma->ma_blks, ==, zb->zb_blkid);
257 ma->ma_blks++;
258
259 /* Abort immediately if we have encountered gang blocks */
260 if (BP_IS_GANG(bp))
261 return (SET_ERROR(EFRAGS));
262
263 /*
264 * See if the block is at the end of the previous extent.
265 */
266 ze = list_tail(&ma->ma_zv->zv_extents);
267 if (ze &&
268 DVA_GET_VDEV(BP_IDENTITY(bp)) == DVA_GET_VDEV(&ze->ze_dva) &&
269 DVA_GET_OFFSET(BP_IDENTITY(bp)) ==
270 DVA_GET_OFFSET(&ze->ze_dva) + ze->ze_nblks * bs) {
271 ze->ze_nblks++;
272 return (0);
273 }
274
275 dprintf_bp(bp, "%s", "next blkptr:");
276
277 /* start a new extent */
278 ze = kmem_zalloc(sizeof (zvol_extent_t), KM_SLEEP);
279 ze->ze_dva = bp->blk_dva[0]; /* structure assignment */
280 ze->ze_nblks = 1;
281 list_insert_tail(&ma->ma_zv->zv_extents, ze);
282 return (0);
283 }
284
285 static void
286 zvol_free_extents(zvol_state_t *zv)
287 {
288 zvol_extent_t *ze;
289
290 while (ze = list_head(&zv->zv_extents)) {
291 list_remove(&zv->zv_extents, ze);
292 kmem_free(ze, sizeof (zvol_extent_t));
293 }
294 }
295
296 static int
297 zvol_get_lbas(zvol_state_t *zv)
298 {
299 objset_t *os = zv->zv_objset;
300 struct maparg ma;
301 int err;
302
303 ma.ma_zv = zv;
304 ma.ma_blks = 0;
305 zvol_free_extents(zv);
306
307 /* commit any in-flight changes before traversing the dataset */
308 txg_wait_synced(dmu_objset_pool(os), 0);
309 err = traverse_dataset(dmu_objset_ds(os), 0,
310 TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA, zvol_map_block, &ma);
311 if (err || ma.ma_blks != (zv->zv_volsize / zv->zv_volblocksize)) {
312 zvol_free_extents(zv);
313 return (err ? err : EIO);
314 }
315
316 return (0);
317 }
318
319 /* ARGSUSED */
320 void
321 zvol_create_cb(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx)
322 {
323 zfs_creat_t *zct = arg;
324 nvlist_t *nvprops = zct->zct_props;
325 int error;
326 uint64_t volblocksize, volsize;
327
328 VERIFY(nvlist_lookup_uint64(nvprops,
329 zfs_prop_to_name(ZFS_PROP_VOLSIZE), &volsize) == 0);
330 if (nvlist_lookup_uint64(nvprops,
331 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &volblocksize) != 0)
332 volblocksize = zfs_prop_default_numeric(ZFS_PROP_VOLBLOCKSIZE);
333
334 /*
335 * These properties must be removed from the list so the generic
336 * property setting step won't apply to them.
337 */
338 VERIFY(nvlist_remove_all(nvprops,
339 zfs_prop_to_name(ZFS_PROP_VOLSIZE)) == 0);
340 (void) nvlist_remove_all(nvprops,
341 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE));
342
343 error = dmu_object_claim(os, ZVOL_OBJ, DMU_OT_ZVOL, volblocksize,
344 DMU_OT_NONE, 0, tx);
345 ASSERT(error == 0);
346
347 error = zap_create_claim(os, ZVOL_ZAP_OBJ, DMU_OT_ZVOL_PROP,
348 DMU_OT_NONE, 0, tx);
349 ASSERT(error == 0);
350
351 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize, tx);
352 ASSERT(error == 0);
353 }
354
355 /*
356 * Replay a TX_TRUNCATE ZIL transaction if asked. TX_TRUNCATE is how we
357 * implement DKIOCFREE/free-long-range.
358 */
359 static int
360 zvol_replay_truncate(zvol_state_t *zv, lr_truncate_t *lr, boolean_t byteswap)
361 {
362 uint64_t offset, length;
363
364 if (byteswap)
365 byteswap_uint64_array(lr, sizeof (*lr));
366
367 offset = lr->lr_offset;
368 length = lr->lr_length;
369
370 return (dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, offset, length));
371 }
372
373 /*
374 * Replay a TX_WRITE ZIL transaction that didn't get committed
375 * after a system failure
376 */
377 static int
378 zvol_replay_write(zvol_state_t *zv, lr_write_t *lr, boolean_t byteswap)
379 {
380 objset_t *os = zv->zv_objset;
381 char *data = (char *)(lr + 1); /* data follows lr_write_t */
382 uint64_t offset, length;
383 dmu_tx_t *tx;
384 int error;
385
386 if (byteswap)
387 byteswap_uint64_array(lr, sizeof (*lr));
388
389 offset = lr->lr_offset;
390 length = lr->lr_length;
391
392 /* If it's a dmu_sync() block, write the whole block */
393 if (lr->lr_common.lrc_reclen == sizeof (lr_write_t)) {
394 uint64_t blocksize = BP_GET_LSIZE(&lr->lr_blkptr);
395 if (length < blocksize) {
396 offset -= offset % blocksize;
397 length = blocksize;
398 }
399 }
400
401 tx = dmu_tx_create(os);
402 dmu_tx_hold_write(tx, ZVOL_OBJ, offset, length);
403 error = dmu_tx_assign(tx, TXG_WAIT);
404 if (error) {
405 dmu_tx_abort(tx);
406 } else {
407 dmu_write(os, ZVOL_OBJ, offset, length, data, tx);
408 dmu_tx_commit(tx);
409 }
410
411 return (error);
412 }
413
414 /* ARGSUSED */
415 static int
416 zvol_replay_err(zvol_state_t *zv, lr_t *lr, boolean_t byteswap)
417 {
418 return (SET_ERROR(ENOTSUP));
419 }
420
421 /*
422 * Callback vectors for replaying records.
423 * Only TX_WRITE and TX_TRUNCATE are needed for zvol.
424 */
425 zil_replay_func_t *zvol_replay_vector[TX_MAX_TYPE] = {
426 zvol_replay_err, /* 0 no such transaction type */
427 zvol_replay_err, /* TX_CREATE */
428 zvol_replay_err, /* TX_MKDIR */
429 zvol_replay_err, /* TX_MKXATTR */
430 zvol_replay_err, /* TX_SYMLINK */
431 zvol_replay_err, /* TX_REMOVE */
432 zvol_replay_err, /* TX_RMDIR */
433 zvol_replay_err, /* TX_LINK */
434 zvol_replay_err, /* TX_RENAME */
435 zvol_replay_write, /* TX_WRITE */
436 zvol_replay_truncate, /* TX_TRUNCATE */
437 zvol_replay_err, /* TX_SETATTR */
438 zvol_replay_err, /* TX_ACL */
439 zvol_replay_err, /* TX_CREATE_ACL */
440 zvol_replay_err, /* TX_CREATE_ATTR */
441 zvol_replay_err, /* TX_CREATE_ACL_ATTR */
442 zvol_replay_err, /* TX_MKDIR_ACL */
443 zvol_replay_err, /* TX_MKDIR_ATTR */
444 zvol_replay_err, /* TX_MKDIR_ACL_ATTR */
445 zvol_replay_err, /* TX_WRITE2 */
446 };
447
448 int
449 zvol_name2minor(const char *name, minor_t *minor)
450 {
451 zvol_state_t *zv;
452
453 mutex_enter(&zfsdev_state_lock);
454 zv = zvol_minor_lookup(name);
455 if (minor && zv)
456 *minor = zv->zv_minor;
457 mutex_exit(&zfsdev_state_lock);
458 return (zv ? 0 : -1);
459 }
460
461 /*
462 * Create a minor node (plus a whole lot more) for the specified volume.
463 */
464 int
465 zvol_create_minor(const char *name)
466 {
467 zfs_soft_state_t *zs;
468 zvol_state_t *zv;
469 objset_t *os;
470 dmu_object_info_t doi;
471 minor_t minor = 0;
472 char chrbuf[30], blkbuf[30];
473 int error;
474
475 mutex_enter(&zfsdev_state_lock);
476
477 if (zvol_minor_lookup(name) != NULL) {
478 mutex_exit(&zfsdev_state_lock);
479 return (SET_ERROR(EEXIST));
480 }
481
482 /* lie and say we're read-only */
483 error = dmu_objset_own(name, DMU_OST_ZVOL, B_TRUE, FTAG, &os);
484
485 if (error) {
486 mutex_exit(&zfsdev_state_lock);
487 return (error);
488 }
489
490 if ((minor = zfsdev_minor_alloc()) == 0) {
491 dmu_objset_disown(os, FTAG);
492 mutex_exit(&zfsdev_state_lock);
493 return (SET_ERROR(ENXIO));
494 }
495
496 if (ddi_soft_state_zalloc(zfsdev_state, minor) != DDI_SUCCESS) {
497 dmu_objset_disown(os, FTAG);
498 mutex_exit(&zfsdev_state_lock);
499 return (SET_ERROR(EAGAIN));
500 }
501 (void) ddi_prop_update_string(minor, zfs_dip, ZVOL_PROP_NAME,
502 (char *)name);
503
504 (void) snprintf(chrbuf, sizeof (chrbuf), "%u,raw", minor);
505
506 if (ddi_create_minor_node(zfs_dip, chrbuf, S_IFCHR,
507 minor, DDI_PSEUDO, 0) == DDI_FAILURE) {
508 ddi_soft_state_free(zfsdev_state, minor);
509 dmu_objset_disown(os, FTAG);
510 mutex_exit(&zfsdev_state_lock);
511 return (SET_ERROR(EAGAIN));
512 }
513
514 (void) snprintf(blkbuf, sizeof (blkbuf), "%u", minor);
515
516 if (ddi_create_minor_node(zfs_dip, blkbuf, S_IFBLK,
517 minor, DDI_PSEUDO, 0) == DDI_FAILURE) {
518 ddi_remove_minor_node(zfs_dip, chrbuf);
519 ddi_soft_state_free(zfsdev_state, minor);
520 dmu_objset_disown(os, FTAG);
521 mutex_exit(&zfsdev_state_lock);
522 return (SET_ERROR(EAGAIN));
523 }
524
525 zs = ddi_get_soft_state(zfsdev_state, minor);
526 zs->zss_type = ZSST_ZVOL;
527 zv = zs->zss_data = kmem_zalloc(sizeof (zvol_state_t), KM_SLEEP);
528 (void) strlcpy(zv->zv_name, name, MAXPATHLEN);
529 zv->zv_min_bs = DEV_BSHIFT;
530 zv->zv_minor = minor;
531 zv->zv_objset = os;
532 if (dmu_objset_is_snapshot(os) || !spa_writeable(dmu_objset_spa(os)))
533 zv->zv_flags |= ZVOL_RDONLY;
534 mutex_init(&zv->zv_znode.z_range_lock, NULL, MUTEX_DEFAULT, NULL);
535 avl_create(&zv->zv_znode.z_range_avl, zfs_range_compare,
536 sizeof (rl_t), offsetof(rl_t, r_node));
537 list_create(&zv->zv_extents, sizeof (zvol_extent_t),
538 offsetof(zvol_extent_t, ze_node));
539 /* get and cache the blocksize */
540 error = dmu_object_info(os, ZVOL_OBJ, &doi);
541 ASSERT(error == 0);
542 zv->zv_volblocksize = doi.doi_data_block_size;
543
544 if (spa_writeable(dmu_objset_spa(os))) {
545 if (zil_replay_disable)
546 zil_destroy(dmu_objset_zil(os), B_FALSE);
547 else
548 zil_replay(os, zv, zvol_replay_vector);
549 }
550 dmu_objset_disown(os, FTAG);
551 zv->zv_objset = NULL;
552
553 zvol_minors++;
554
555 mutex_exit(&zfsdev_state_lock);
556
557 return (0);
558 }
559
560 /*
561 * Remove minor node for the specified volume.
562 */
563 static int
564 zvol_remove_zv(zvol_state_t *zv)
565 {
566 char nmbuf[20];
567 minor_t minor = zv->zv_minor;
568
569 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
570 if (zv->zv_total_opens != 0)
571 return (SET_ERROR(EBUSY));
572
573 (void) snprintf(nmbuf, sizeof (nmbuf), "%u,raw", minor);
574 ddi_remove_minor_node(zfs_dip, nmbuf);
575
576 (void) snprintf(nmbuf, sizeof (nmbuf), "%u", minor);
577 ddi_remove_minor_node(zfs_dip, nmbuf);
578
579 avl_destroy(&zv->zv_znode.z_range_avl);
580 mutex_destroy(&zv->zv_znode.z_range_lock);
581
582 kmem_free(zv, sizeof (zvol_state_t));
583
584 ddi_soft_state_free(zfsdev_state, minor);
585
586 zvol_minors--;
587 return (0);
588 }
589
590 int
591 zvol_remove_minor(const char *name)
592 {
593 zvol_state_t *zv;
594 int rc;
595
596 mutex_enter(&zfsdev_state_lock);
597 if ((zv = zvol_minor_lookup(name)) == NULL) {
598 mutex_exit(&zfsdev_state_lock);
599 return (SET_ERROR(ENXIO));
600 }
601 rc = zvol_remove_zv(zv);
602 mutex_exit(&zfsdev_state_lock);
603 return (rc);
604 }
605
606 int
607 zvol_first_open(zvol_state_t *zv)
608 {
609 objset_t *os;
610 uint64_t volsize;
611 int error;
612 uint64_t readonly;
613
614 /* lie and say we're read-only */
615 error = dmu_objset_own(zv->zv_name, DMU_OST_ZVOL, B_TRUE,
616 zvol_tag, &os);
617 if (error)
618 return (error);
619
620 zv->zv_objset = os;
621 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize);
622 if (error) {
623 ASSERT(error == 0);
624 dmu_objset_disown(os, zvol_tag);
625 return (error);
626 }
627
628 error = dmu_bonus_hold(os, ZVOL_OBJ, zvol_tag, &zv->zv_dbuf);
629 if (error) {
630 dmu_objset_disown(os, zvol_tag);
631 return (error);
632 }
633
634 zvol_size_changed(zv, volsize);
635 zv->zv_zilog = zil_open(os, zvol_get_data);
636
637 VERIFY(dsl_prop_get_integer(zv->zv_name, "readonly", &readonly,
638 NULL) == 0);
639 if (readonly || dmu_objset_is_snapshot(os) ||
640 !spa_writeable(dmu_objset_spa(os)))
641 zv->zv_flags |= ZVOL_RDONLY;
642 else
643 zv->zv_flags &= ~ZVOL_RDONLY;
644 return (error);
645 }
646
647 void
648 zvol_last_close(zvol_state_t *zv)
649 {
650 zil_close(zv->zv_zilog);
651 zv->zv_zilog = NULL;
652
653 dmu_buf_rele(zv->zv_dbuf, zvol_tag);
654 zv->zv_dbuf = NULL;
655
656 /*
657 * Evict cached data
658 */
659 if (dsl_dataset_is_dirty(dmu_objset_ds(zv->zv_objset)) &&
660 !(zv->zv_flags & ZVOL_RDONLY))
661 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
662 dmu_objset_evict_dbufs(zv->zv_objset);
663
664 dmu_objset_disown(zv->zv_objset, zvol_tag);
665 zv->zv_objset = NULL;
666 }
667
668 int
669 zvol_prealloc(zvol_state_t *zv)
670 {
671 objset_t *os = zv->zv_objset;
672 dmu_tx_t *tx;
673 uint64_t refd, avail, usedobjs, availobjs;
674 uint64_t resid = zv->zv_volsize;
675 uint64_t off = 0;
676
677 /* Check the space usage before attempting to allocate the space */
678 dmu_objset_space(os, &refd, &avail, &usedobjs, &availobjs);
679 if (avail < zv->zv_volsize)
680 return (SET_ERROR(ENOSPC));
681
682 /* Free old extents if they exist */
683 zvol_free_extents(zv);
684
685 while (resid != 0) {
686 int error;
687 uint64_t bytes = MIN(resid, SPA_MAXBLOCKSIZE);
688
689 tx = dmu_tx_create(os);
690 dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes);
691 error = dmu_tx_assign(tx, TXG_WAIT);
692 if (error) {
693 dmu_tx_abort(tx);
694 (void) dmu_free_long_range(os, ZVOL_OBJ, 0, off);
695 return (error);
696 }
697 dmu_prealloc(os, ZVOL_OBJ, off, bytes, tx);
698 dmu_tx_commit(tx);
699 off += bytes;
700 resid -= bytes;
701 }
702 txg_wait_synced(dmu_objset_pool(os), 0);
703
704 return (0);
705 }
706
707 static int
708 zvol_update_volsize(objset_t *os, uint64_t volsize)
709 {
710 dmu_tx_t *tx;
711 int error;
712
713 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
714
715 tx = dmu_tx_create(os);
716 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
717 error = dmu_tx_assign(tx, TXG_WAIT);
718 if (error) {
719 dmu_tx_abort(tx);
720 return (error);
721 }
722
723 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1,
724 &volsize, tx);
725 dmu_tx_commit(tx);
726
727 if (error == 0)
728 error = dmu_free_long_range(os,
729 ZVOL_OBJ, volsize, DMU_OBJECT_END);
730 return (error);
731 }
732
733 void
734 zvol_remove_minors(const char *name)
735 {
736 zvol_state_t *zv;
737 char *namebuf;
738 minor_t minor;
739
740 namebuf = kmem_zalloc(strlen(name) + 2, KM_SLEEP);
741 (void) strncpy(namebuf, name, strlen(name));
742 (void) strcat(namebuf, "/");
743 mutex_enter(&zfsdev_state_lock);
744 for (minor = 1; minor <= ZFSDEV_MAX_MINOR; minor++) {
745
746 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
747 if (zv == NULL)
748 continue;
749 if (strncmp(namebuf, zv->zv_name, strlen(namebuf)) == 0)
750 (void) zvol_remove_zv(zv);
751 }
752 kmem_free(namebuf, strlen(name) + 2);
753
754 mutex_exit(&zfsdev_state_lock);
755 }
756
757 static int
758 zvol_update_live_volsize(zvol_state_t *zv, uint64_t volsize)
759 {
760 uint64_t old_volsize = 0ULL;
761 int error = 0;
762
763 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
764
765 /*
766 * Reinitialize the dump area to the new size. If we
767 * failed to resize the dump area then restore it back to
768 * its original size. We must set the new volsize prior
769 * to calling dumpvp_resize() to ensure that the devices'
770 * size(9P) is not visible by the dump subsystem.
771 */
772 old_volsize = zv->zv_volsize;
773 zvol_size_changed(zv, volsize);
774
775 if (zv->zv_flags & ZVOL_DUMPIFIED) {
776 if ((error = zvol_dumpify(zv)) != 0 ||
777 (error = dumpvp_resize()) != 0) {
778 int dumpify_error;
779
780 (void) zvol_update_volsize(zv->zv_objset, old_volsize);
781 zvol_size_changed(zv, old_volsize);
782 dumpify_error = zvol_dumpify(zv);
783 error = dumpify_error ? dumpify_error : error;
784 }
785 }
786
787 /*
788 * Generate a LUN expansion event.
789 */
790 if (error == 0) {
791 sysevent_id_t eid;
792 nvlist_t *attr;
793 char *physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
794
795 (void) snprintf(physpath, MAXPATHLEN, "%s%u", ZVOL_PSEUDO_DEV,
796 zv->zv_minor);
797
798 VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0);
799 VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0);
800
801 (void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS,
802 ESC_DEV_DLE, attr, &eid, DDI_SLEEP);
803
804 nvlist_free(attr);
805 kmem_free(physpath, MAXPATHLEN);
806 }
807 return (error);
808 }
809
810 int
811 zvol_set_volsize(const char *name, uint64_t volsize)
812 {
813 zvol_state_t *zv = NULL;
814 objset_t *os;
815 int error;
816 dmu_object_info_t doi;
817 uint64_t readonly;
818 boolean_t owned = B_FALSE;
819
820 error = dsl_prop_get_integer(name,
821 zfs_prop_to_name(ZFS_PROP_READONLY), &readonly, NULL);
822 if (error != 0)
823 return (error);
824 if (readonly)
825 return (SET_ERROR(EROFS));
826
827 mutex_enter(&zfsdev_state_lock);
828 zv = zvol_minor_lookup(name);
829
830 if (zv == NULL || zv->zv_objset == NULL) {
831 if ((error = dmu_objset_own(name, DMU_OST_ZVOL, B_FALSE,
832 FTAG, &os)) != 0) {
833 mutex_exit(&zfsdev_state_lock);
834 return (error);
835 }
836 owned = B_TRUE;
837 if (zv != NULL)
838 zv->zv_objset = os;
839 } else {
840 os = zv->zv_objset;
841 }
842
843 if ((error = dmu_object_info(os, ZVOL_OBJ, &doi)) != 0 ||
844 (error = zvol_check_volsize(volsize, doi.doi_data_block_size)) != 0)
845 goto out;
846
847 error = zvol_update_volsize(os, volsize);
848
849 if (error == 0 && zv != NULL)
850 error = zvol_update_live_volsize(zv, volsize);
851 out:
852 if (owned) {
853 dmu_objset_disown(os, FTAG);
854 if (zv != NULL)
855 zv->zv_objset = NULL;
856 }
857 mutex_exit(&zfsdev_state_lock);
858 return (error);
859 }
860
861 /*ARGSUSED*/
862 int
863 zvol_open(dev_t *devp, int flag, int otyp, cred_t *cr)
864 {
865 zvol_state_t *zv;
866 int err = 0;
867
868 mutex_enter(&zfsdev_state_lock);
869
870 zv = zfsdev_get_soft_state(getminor(*devp), ZSST_ZVOL);
871 if (zv == NULL) {
872 mutex_exit(&zfsdev_state_lock);
873 return (SET_ERROR(ENXIO));
874 }
875
876 if (zv->zv_total_opens == 0)
877 err = zvol_first_open(zv);
878 if (err) {
879 mutex_exit(&zfsdev_state_lock);
880 return (err);
881 }
882 if ((flag & FWRITE) && (zv->zv_flags & ZVOL_RDONLY)) {
883 err = SET_ERROR(EROFS);
884 goto out;
885 }
886 if (zv->zv_flags & ZVOL_EXCL) {
887 err = SET_ERROR(EBUSY);
888 goto out;
889 }
890 if (flag & FEXCL) {
891 if (zv->zv_total_opens != 0) {
892 err = SET_ERROR(EBUSY);
893 goto out;
894 }
895 zv->zv_flags |= ZVOL_EXCL;
896 }
897
898 if (zv->zv_open_count[otyp] == 0 || otyp == OTYP_LYR) {
899 zv->zv_open_count[otyp]++;
900 zv->zv_total_opens++;
901 }
902 mutex_exit(&zfsdev_state_lock);
903
904 return (err);
905 out:
906 if (zv->zv_total_opens == 0)
907 zvol_last_close(zv);
908 mutex_exit(&zfsdev_state_lock);
909 return (err);
910 }
911
912 /*ARGSUSED*/
913 int
914 zvol_close(dev_t dev, int flag, int otyp, cred_t *cr)
915 {
916 minor_t minor = getminor(dev);
917 zvol_state_t *zv;
918 int error = 0;
919
920 mutex_enter(&zfsdev_state_lock);
921
922 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
923 if (zv == NULL) {
924 mutex_exit(&zfsdev_state_lock);
925 return (SET_ERROR(ENXIO));
926 }
927
928 if (zv->zv_flags & ZVOL_EXCL) {
929 ASSERT(zv->zv_total_opens == 1);
930 zv->zv_flags &= ~ZVOL_EXCL;
931 }
932
933 /*
934 * If the open count is zero, this is a spurious close.
935 * That indicates a bug in the kernel / DDI framework.
936 */
937 ASSERT(zv->zv_open_count[otyp] != 0);
938 ASSERT(zv->zv_total_opens != 0);
939
940 /*
941 * You may get multiple opens, but only one close.
942 */
943 zv->zv_open_count[otyp]--;
944 zv->zv_total_opens--;
945
946 if (zv->zv_total_opens == 0)
947 zvol_last_close(zv);
948
949 mutex_exit(&zfsdev_state_lock);
950 return (error);
951 }
952
953 static void
954 zvol_get_done(zgd_t *zgd, int error)
955 {
956 if (zgd->zgd_db)
957 dmu_buf_rele(zgd->zgd_db, zgd);
958
959 zfs_range_unlock(zgd->zgd_rl);
960
961 if (error == 0 && zgd->zgd_bp)
962 zil_add_block(zgd->zgd_zilog, zgd->zgd_bp);
963
964 kmem_free(zgd, sizeof (zgd_t));
965 }
966
967 /*
968 * Get data to generate a TX_WRITE intent log record.
969 */
970 static int
971 zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
972 {
973 zvol_state_t *zv = arg;
974 objset_t *os = zv->zv_objset;
975 uint64_t object = ZVOL_OBJ;
976 uint64_t offset = lr->lr_offset;
977 uint64_t size = lr->lr_length; /* length of user data */
978 blkptr_t *bp = &lr->lr_blkptr;
979 dmu_buf_t *db;
980 zgd_t *zgd;
981 int error;
982
983 ASSERT(zio != NULL);
984 ASSERT(size != 0);
985
986 zgd = kmem_zalloc(sizeof (zgd_t), KM_SLEEP);
987 zgd->zgd_zilog = zv->zv_zilog;
988 zgd->zgd_rl = zfs_range_lock(&zv->zv_znode, offset, size, RL_READER);
989
990 /*
991 * Write records come in two flavors: immediate and indirect.
992 * For small writes it's cheaper to store the data with the
993 * log record (immediate); for large writes it's cheaper to
994 * sync the data and get a pointer to it (indirect) so that
995 * we don't have to write the data twice.
996 */
997 if (buf != NULL) { /* immediate write */
998 error = dmu_read(os, object, offset, size, buf,
999 DMU_READ_NO_PREFETCH);
1000 } else {
1001 size = zv->zv_volblocksize;
1002 offset = P2ALIGN(offset, size);
1003 error = dmu_buf_hold(os, object, offset, zgd, &db,
1004 DMU_READ_NO_PREFETCH);
1005 if (error == 0) {
1006 blkptr_t *obp = dmu_buf_get_blkptr(db);
1007 if (obp) {
1008 ASSERT(BP_IS_HOLE(bp));
1009 *bp = *obp;
1010 }
1011
1012 zgd->zgd_db = db;
1013 zgd->zgd_bp = bp;
1014
1015 ASSERT(db->db_offset == offset);
1016 ASSERT(db->db_size == size);
1017
1018 error = dmu_sync(zio, lr->lr_common.lrc_txg,
1019 zvol_get_done, zgd);
1020
1021 if (error == 0)
1022 return (0);
1023 }
1024 }
1025
1026 zvol_get_done(zgd, error);
1027
1028 return (error);
1029 }
1030
1031 /*
1032 * zvol_log_write() handles synchronous writes using TX_WRITE ZIL transactions.
1033 *
1034 * We store data in the log buffers if it's small enough.
1035 * Otherwise we will later flush the data out via dmu_sync().
1036 */
1037 ssize_t zvol_immediate_write_sz = 32768;
1038
1039 static void
1040 zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, offset_t off, ssize_t resid,
1041 boolean_t sync)
1042 {
1043 uint32_t blocksize = zv->zv_volblocksize;
1044 zilog_t *zilog = zv->zv_zilog;
1045 boolean_t slogging;
1046 ssize_t immediate_write_sz;
1047
1048 if (zil_replaying(zilog, tx))
1049 return;
1050
1051 immediate_write_sz = (zilog->zl_logbias == ZFS_LOGBIAS_THROUGHPUT)
1052 ? 0 : zvol_immediate_write_sz;
1053
1054 slogging = spa_has_slogs(zilog->zl_spa) &&
1055 (zilog->zl_logbias == ZFS_LOGBIAS_LATENCY);
1056
1057 while (resid) {
1058 itx_t *itx;
1059 lr_write_t *lr;
1060 ssize_t len;
1061 itx_wr_state_t write_state;
1062
1063 /*
1064 * Unlike zfs_log_write() we can be called with
1065 * upto DMU_MAX_ACCESS/2 (5MB) writes.
1066 */
1067 if (blocksize > immediate_write_sz && !slogging &&
1068 resid >= blocksize && off % blocksize == 0) {
1069 write_state = WR_INDIRECT; /* uses dmu_sync */
1070 len = blocksize;
1071 } else if (sync) {
1072 write_state = WR_COPIED;
1073 len = MIN(ZIL_MAX_LOG_DATA, resid);
1074 } else {
1075 write_state = WR_NEED_COPY;
1076 len = MIN(ZIL_MAX_LOG_DATA, resid);
1077 }
1078
1079 itx = zil_itx_create(TX_WRITE, sizeof (*lr) +
1080 (write_state == WR_COPIED ? len : 0));
1081 lr = (lr_write_t *)&itx->itx_lr;
1082 if (write_state == WR_COPIED && dmu_read(zv->zv_objset,
1083 ZVOL_OBJ, off, len, lr + 1, DMU_READ_NO_PREFETCH) != 0) {
1084 zil_itx_destroy(itx);
1085 itx = zil_itx_create(TX_WRITE, sizeof (*lr));
1086 lr = (lr_write_t *)&itx->itx_lr;
1087 write_state = WR_NEED_COPY;
1088 }
1089
1090 itx->itx_wr_state = write_state;
1091 if (write_state == WR_NEED_COPY)
1092 itx->itx_sod += len;
1093 lr->lr_foid = ZVOL_OBJ;
1094 lr->lr_offset = off;
1095 lr->lr_length = len;
1096 lr->lr_blkoff = 0;
1097 BP_ZERO(&lr->lr_blkptr);
1098
1099 itx->itx_private = zv;
1100 itx->itx_sync = sync;
1101
1102 zil_itx_assign(zilog, itx, tx);
1103
1104 off += len;
1105 resid -= len;
1106 }
1107 }
1108
1109 static int
1110 zvol_dumpio_vdev(vdev_t *vd, void *addr, uint64_t offset, uint64_t origoffset,
1111 uint64_t size, boolean_t doread, boolean_t isdump)
1112 {
1113 vdev_disk_t *dvd;
1114 int c;
1115 int numerrors = 0;
1116
1117 if (vd->vdev_ops == &vdev_mirror_ops ||
1118 vd->vdev_ops == &vdev_replacing_ops ||
1119 vd->vdev_ops == &vdev_spare_ops) {
1120 for (c = 0; c < vd->vdev_children; c++) {
1121 int err = zvol_dumpio_vdev(vd->vdev_child[c],
1122 addr, offset, origoffset, size, doread, isdump);
1123 if (err != 0) {
1124 numerrors++;
1125 } else if (doread) {
1126 break;
1127 }
1128 }
1129 }
1130
1131 if (!vd->vdev_ops->vdev_op_leaf && vd->vdev_ops != &vdev_raidz_ops)
1132 return (numerrors < vd->vdev_children ? 0 : EIO);
1133
1134 if (doread && !vdev_readable(vd))
1135 return (SET_ERROR(EIO));
1136 else if (!doread && !vdev_writeable(vd))
1137 return (SET_ERROR(EIO));
1138
1139 if (vd->vdev_ops == &vdev_raidz_ops) {
1140 return (vdev_raidz_physio(vd,
1141 addr, size, offset, origoffset, doread, isdump));
1142 }
1143
1144 offset += VDEV_LABEL_START_SIZE;
1145
1146 if (ddi_in_panic() || isdump) {
1147 ASSERT(!doread);
1148 if (doread)
1149 return (SET_ERROR(EIO));
1150 dvd = vd->vdev_tsd;
1151 ASSERT3P(dvd, !=, NULL);
1152 return (ldi_dump(dvd->vd_lh, addr, lbtodb(offset),
1153 lbtodb(size)));
1154 } else {
1155 dvd = vd->vdev_tsd;
1156 ASSERT3P(dvd, !=, NULL);
1157 return (vdev_disk_ldi_physio(dvd->vd_lh, addr, size,
1158 offset, doread ? B_READ : B_WRITE));
1159 }
1160 }
1161
1162 static int
1163 zvol_dumpio(zvol_state_t *zv, void *addr, uint64_t offset, uint64_t size,
1164 boolean_t doread, boolean_t isdump)
1165 {
1166 vdev_t *vd;
1167 int error;
1168 zvol_extent_t *ze;
1169 spa_t *spa = dmu_objset_spa(zv->zv_objset);
1170
1171 /* Must be sector aligned, and not stradle a block boundary. */
1172 if (P2PHASE(offset, DEV_BSIZE) || P2PHASE(size, DEV_BSIZE) ||
1173 P2BOUNDARY(offset, size, zv->zv_volblocksize)) {
1174 return (SET_ERROR(EINVAL));
1175 }
1176 ASSERT(size <= zv->zv_volblocksize);
1177
1178 /* Locate the extent this belongs to */
1179 ze = list_head(&zv->zv_extents);
1180 while (offset >= ze->ze_nblks * zv->zv_volblocksize) {
1181 offset -= ze->ze_nblks * zv->zv_volblocksize;
1182 ze = list_next(&zv->zv_extents, ze);
1183 }
1184
1185 if (ze == NULL)
1186 return (SET_ERROR(EINVAL));
1187
1188 if (!ddi_in_panic())
1189 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
1190
1191 vd = vdev_lookup_top(spa, DVA_GET_VDEV(&ze->ze_dva));
1192 offset += DVA_GET_OFFSET(&ze->ze_dva);
1193 error = zvol_dumpio_vdev(vd, addr, offset, DVA_GET_OFFSET(&ze->ze_dva),
1194 size, doread, isdump);
1195
1196 if (!ddi_in_panic())
1197 spa_config_exit(spa, SCL_STATE, FTAG);
1198
1199 return (error);
1200 }
1201
1202 int
1203 zvol_strategy(buf_t *bp)
1204 {
1205 zfs_soft_state_t *zs = NULL;
1206 zvol_state_t *zv;
1207 uint64_t off, volsize;
1208 size_t resid;
1209 char *addr;
1210 objset_t *os;
1211 rl_t *rl;
1212 int error = 0;
1213 boolean_t doread = bp->b_flags & B_READ;
1214 boolean_t is_dumpified;
1215 boolean_t sync;
1216
1217 if (getminor(bp->b_edev) == 0) {
1218 error = SET_ERROR(EINVAL);
1219 } else {
1220 zs = ddi_get_soft_state(zfsdev_state, getminor(bp->b_edev));
1221 if (zs == NULL)
1222 error = SET_ERROR(ENXIO);
1223 else if (zs->zss_type != ZSST_ZVOL)
1224 error = SET_ERROR(EINVAL);
1225 }
1226
1227 if (error) {
1228 bioerror(bp, error);
1229 biodone(bp);
1230 return (0);
1231 }
1232
1233 zv = zs->zss_data;
1234
1235 if (!(bp->b_flags & B_READ) && (zv->zv_flags & ZVOL_RDONLY)) {
1236 bioerror(bp, EROFS);
1237 biodone(bp);
1238 return (0);
1239 }
1240
1241 off = ldbtob(bp->b_blkno);
1242 volsize = zv->zv_volsize;
1243
1244 os = zv->zv_objset;
1245 ASSERT(os != NULL);
1246
1247 bp_mapin(bp);
1248 addr = bp->b_un.b_addr;
1249 resid = bp->b_bcount;
1250
1251 if (resid > 0 && (off < 0 || off >= volsize)) {
1252 bioerror(bp, EIO);
1253 biodone(bp);
1254 return (0);
1255 }
1256
1257 is_dumpified = zv->zv_flags & ZVOL_DUMPIFIED;
1258 sync = ((!(bp->b_flags & B_ASYNC) &&
1259 !(zv->zv_flags & ZVOL_WCE)) ||
1260 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS)) &&
1261 !doread && !is_dumpified;
1262
1263 /*
1264 * There must be no buffer changes when doing a dmu_sync() because
1265 * we can't change the data whilst calculating the checksum.
1266 */
1267 rl = zfs_range_lock(&zv->zv_znode, off, resid,
1268 doread ? RL_READER : RL_WRITER);
1269
1270 while (resid != 0 && off < volsize) {
1271 size_t size = MIN(resid, zvol_maxphys);
1272 if (is_dumpified) {
1273 size = MIN(size, P2END(off, zv->zv_volblocksize) - off);
1274 error = zvol_dumpio(zv, addr, off, size,
1275 doread, B_FALSE);
1276 } else if (doread) {
1277 error = dmu_read(os, ZVOL_OBJ, off, size, addr,
1278 DMU_READ_PREFETCH);
1279 } else {
1280 dmu_tx_t *tx = dmu_tx_create(os);
1281 dmu_tx_hold_write(tx, ZVOL_OBJ, off, size);
1282 error = dmu_tx_assign(tx, TXG_WAIT);
1283 if (error) {
1284 dmu_tx_abort(tx);
1285 } else {
1286 dmu_write(os, ZVOL_OBJ, off, size, addr, tx);
1287 zvol_log_write(zv, tx, off, size, sync);
1288 dmu_tx_commit(tx);
1289 }
1290 }
1291 if (error) {
1292 /* convert checksum errors into IO errors */
1293 if (error == ECKSUM)
1294 error = SET_ERROR(EIO);
1295 break;
1296 }
1297 off += size;
1298 addr += size;
1299 resid -= size;
1300 }
1301 zfs_range_unlock(rl);
1302
1303 if ((bp->b_resid = resid) == bp->b_bcount)
1304 bioerror(bp, off > volsize ? EINVAL : error);
1305
1306 if (sync)
1307 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1308 biodone(bp);
1309
1310 return (0);
1311 }
1312
1313 /*
1314 * Set the buffer count to the zvol maximum transfer.
1315 * Using our own routine instead of the default minphys()
1316 * means that for larger writes we write bigger buffers on X86
1317 * (128K instead of 56K) and flush the disk write cache less often
1318 * (every zvol_maxphys - currently 1MB) instead of minphys (currently
1319 * 56K on X86 and 128K on sparc).
1320 */
1321 void
1322 zvol_minphys(struct buf *bp)
1323 {
1324 if (bp->b_bcount > zvol_maxphys)
1325 bp->b_bcount = zvol_maxphys;
1326 }
1327
1328 int
1329 zvol_dump(dev_t dev, caddr_t addr, daddr_t blkno, int nblocks)
1330 {
1331 minor_t minor = getminor(dev);
1332 zvol_state_t *zv;
1333 int error = 0;
1334 uint64_t size;
1335 uint64_t boff;
1336 uint64_t resid;
1337
1338 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1339 if (zv == NULL)
1340 return (SET_ERROR(ENXIO));
1341
1342 if ((zv->zv_flags & ZVOL_DUMPIFIED) == 0)
1343 return (SET_ERROR(EINVAL));
1344
1345 boff = ldbtob(blkno);
1346 resid = ldbtob(nblocks);
1347
1348 VERIFY3U(boff + resid, <=, zv->zv_volsize);
1349
1350 while (resid) {
1351 size = MIN(resid, P2END(boff, zv->zv_volblocksize) - boff);
1352 error = zvol_dumpio(zv, addr, boff, size, B_FALSE, B_TRUE);
1353 if (error)
1354 break;
1355 boff += size;
1356 addr += size;
1357 resid -= size;
1358 }
1359
1360 return (error);
1361 }
1362
1363 /*ARGSUSED*/
1364 int
1365 zvol_read(dev_t dev, uio_t *uio, cred_t *cr)
1366 {
1367 minor_t minor = getminor(dev);
1368 zvol_state_t *zv;
1369 uint64_t volsize;
1370 rl_t *rl;
1371 int error = 0;
1372
1373 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1374 if (zv == NULL)
1375 return (SET_ERROR(ENXIO));
1376
1377 volsize = zv->zv_volsize;
1378 if (uio->uio_resid > 0 &&
1379 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize))
1380 return (SET_ERROR(EIO));
1381
1382 if (zv->zv_flags & ZVOL_DUMPIFIED) {
1383 error = physio(zvol_strategy, NULL, dev, B_READ,
1384 zvol_minphys, uio);
1385 return (error);
1386 }
1387
1388 rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid,
1389 RL_READER);
1390 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) {
1391 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1);
1392
1393 /* don't read past the end */
1394 if (bytes > volsize - uio->uio_loffset)
1395 bytes = volsize - uio->uio_loffset;
1396
1397 error = dmu_read_uio(zv->zv_objset, ZVOL_OBJ, uio, bytes);
1398 if (error) {
1399 /* convert checksum errors into IO errors */
1400 if (error == ECKSUM)
1401 error = SET_ERROR(EIO);
1402 break;
1403 }
1404 }
1405 zfs_range_unlock(rl);
1406 return (error);
1407 }
1408
1409 /*ARGSUSED*/
1410 int
1411 zvol_write(dev_t dev, uio_t *uio, cred_t *cr)
1412 {
1413 minor_t minor = getminor(dev);
1414 zvol_state_t *zv;
1415 uint64_t volsize;
1416 rl_t *rl;
1417 int error = 0;
1418 boolean_t sync;
1419
1420 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1421 if (zv == NULL)
1422 return (SET_ERROR(ENXIO));
1423
1424 volsize = zv->zv_volsize;
1425 if (uio->uio_resid > 0 &&
1426 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize))
1427 return (SET_ERROR(EIO));
1428
1429 if (zv->zv_flags & ZVOL_DUMPIFIED) {
1430 error = physio(zvol_strategy, NULL, dev, B_WRITE,
1431 zvol_minphys, uio);
1432 return (error);
1433 }
1434
1435 sync = !(zv->zv_flags & ZVOL_WCE) ||
1436 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS);
1437
1438 rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid,
1439 RL_WRITER);
1440 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) {
1441 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1);
1442 uint64_t off = uio->uio_loffset;
1443 dmu_tx_t *tx = dmu_tx_create(zv->zv_objset);
1444
1445 if (bytes > volsize - off) /* don't write past the end */
1446 bytes = volsize - off;
1447
1448 dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes);
1449 error = dmu_tx_assign(tx, TXG_WAIT);
1450 if (error) {
1451 dmu_tx_abort(tx);
1452 break;
1453 }
1454 error = dmu_write_uio_dbuf(zv->zv_dbuf, uio, bytes, tx);
1455 if (error == 0)
1456 zvol_log_write(zv, tx, off, bytes, sync);
1457 dmu_tx_commit(tx);
1458
1459 if (error)
1460 break;
1461 }
1462 zfs_range_unlock(rl);
1463 if (sync)
1464 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1465 return (error);
1466 }
1467
1468 int
1469 zvol_getefi(void *arg, int flag, uint64_t vs, uint8_t bs)
1470 {
1471 struct uuid uuid = EFI_RESERVED;
1472 efi_gpe_t gpe = { 0 };
1473 uint32_t crc;
1474 dk_efi_t efi;
1475 int length;
1476 char *ptr;
1477
1478 if (ddi_copyin(arg, &efi, sizeof (dk_efi_t), flag))
1479 return (SET_ERROR(EFAULT));
1480 ptr = (char *)(uintptr_t)efi.dki_data_64;
1481 length = efi.dki_length;
1482 /*
1483 * Some clients may attempt to request a PMBR for the
1484 * zvol. Currently this interface will return EINVAL to
1485 * such requests. These requests could be supported by
1486 * adding a check for lba == 0 and consing up an appropriate
1487 * PMBR.
1488 */
1489 if (efi.dki_lba < 1 || efi.dki_lba > 2 || length <= 0)
1490 return (SET_ERROR(EINVAL));
1491
1492 gpe.efi_gpe_StartingLBA = LE_64(34ULL);
1493 gpe.efi_gpe_EndingLBA = LE_64((vs >> bs) - 1);
1494 UUID_LE_CONVERT(gpe.efi_gpe_PartitionTypeGUID, uuid);
1495
1496 if (efi.dki_lba == 1) {
1497 efi_gpt_t gpt = { 0 };
1498
1499 gpt.efi_gpt_Signature = LE_64(EFI_SIGNATURE);
1500 gpt.efi_gpt_Revision = LE_32(EFI_VERSION_CURRENT);
1501 gpt.efi_gpt_HeaderSize = LE_32(sizeof (gpt));
1502 gpt.efi_gpt_MyLBA = LE_64(1ULL);
1503 gpt.efi_gpt_FirstUsableLBA = LE_64(34ULL);
1504 gpt.efi_gpt_LastUsableLBA = LE_64((vs >> bs) - 1);
1505 gpt.efi_gpt_PartitionEntryLBA = LE_64(2ULL);
1506 gpt.efi_gpt_NumberOfPartitionEntries = LE_32(1);
1507 gpt.efi_gpt_SizeOfPartitionEntry =
1508 LE_32(sizeof (efi_gpe_t));
1509 CRC32(crc, &gpe, sizeof (gpe), -1U, crc32_table);
1510 gpt.efi_gpt_PartitionEntryArrayCRC32 = LE_32(~crc);
1511 CRC32(crc, &gpt, sizeof (gpt), -1U, crc32_table);
1512 gpt.efi_gpt_HeaderCRC32 = LE_32(~crc);
1513 if (ddi_copyout(&gpt, ptr, MIN(sizeof (gpt), length),
1514 flag))
1515 return (SET_ERROR(EFAULT));
1516 ptr += sizeof (gpt);
1517 length -= sizeof (gpt);
1518 }
1519 if (length > 0 && ddi_copyout(&gpe, ptr, MIN(sizeof (gpe),
1520 length), flag))
1521 return (SET_ERROR(EFAULT));
1522 return (0);
1523 }
1524
1525 /*
1526 * BEGIN entry points to allow external callers access to the volume.
1527 */
1528 /*
1529 * Return the volume parameters needed for access from an external caller.
1530 * These values are invariant as long as the volume is held open.
1531 */
1532 int
1533 zvol_get_volume_params(minor_t minor, uint64_t *blksize,
1534 uint64_t *max_xfer_len, void **minor_hdl, void **objset_hdl, void **zil_hdl,
1535 void **rl_hdl, void **bonus_hdl)
1536 {
1537 zvol_state_t *zv;
1538
1539 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1540 if (zv == NULL)
1541 return (SET_ERROR(ENXIO));
1542 if (zv->zv_flags & ZVOL_DUMPIFIED)
1543 return (SET_ERROR(ENXIO));
1544
1545 ASSERT(blksize && max_xfer_len && minor_hdl &&
1546 objset_hdl && zil_hdl && rl_hdl && bonus_hdl);
1547
1548 *blksize = zv->zv_volblocksize;
1549 *max_xfer_len = (uint64_t)zvol_maxphys;
1550 *minor_hdl = zv;
1551 *objset_hdl = zv->zv_objset;
1552 *zil_hdl = zv->zv_zilog;
1553 *rl_hdl = &zv->zv_znode;
1554 *bonus_hdl = zv->zv_dbuf;
1555 return (0);
1556 }
1557
1558 /*
1559 * Return the current volume size to an external caller.
1560 * The size can change while the volume is open.
1561 */
1562 uint64_t
1563 zvol_get_volume_size(void *minor_hdl)
1564 {
1565 zvol_state_t *zv = minor_hdl;
1566
1567 return (zv->zv_volsize);
1568 }
1569
1570 /*
1571 * Return the current WCE setting to an external caller.
1572 * The WCE setting can change while the volume is open.
1573 */
1574 int
1575 zvol_get_volume_wce(void *minor_hdl)
1576 {
1577 zvol_state_t *zv = minor_hdl;
1578
1579 return ((zv->zv_flags & ZVOL_WCE) ? 1 : 0);
1580 }
1581
1582 /*
1583 * Entry point for external callers to zvol_log_write
1584 */
1585 void
1586 zvol_log_write_minor(void *minor_hdl, dmu_tx_t *tx, offset_t off, ssize_t resid,
1587 boolean_t sync)
1588 {
1589 zvol_state_t *zv = minor_hdl;
1590
1591 zvol_log_write(zv, tx, off, resid, sync);
1592 }
1593 /*
1594 * END entry points to allow external callers access to the volume.
1595 */
1596
1597 /*
1598 * Log a DKIOCFREE/free-long-range to the ZIL with TX_TRUNCATE.
1599 */
1600 static void
1601 zvol_log_truncate(zvol_state_t *zv, dmu_tx_t *tx, uint64_t off, uint64_t len,
1602 boolean_t sync)
1603 {
1604 itx_t *itx;
1605 lr_truncate_t *lr;
1606 zilog_t *zilog = zv->zv_zilog;
1607
1608 if (zil_replaying(zilog, tx))
1609 return;
1610
1611 itx = zil_itx_create(TX_TRUNCATE, sizeof (*lr));
1612 lr = (lr_truncate_t *)&itx->itx_lr;
1613 lr->lr_foid = ZVOL_OBJ;
1614 lr->lr_offset = off;
1615 lr->lr_length = len;
1616
1617 itx->itx_sync = sync;
1618 zil_itx_assign(zilog, itx, tx);
1619 }
1620
1621 /*
1622 * Dirtbag ioctls to support mkfs(1M) for UFS filesystems. See dkio(7I).
1623 * Also a dirtbag dkio ioctl for unmap/free-block functionality.
1624 */
1625 /*ARGSUSED*/
1626 int
1627 zvol_ioctl(dev_t dev, int cmd, intptr_t arg, int flag, cred_t *cr, int *rvalp)
1628 {
1629 zvol_state_t *zv;
1630 struct dk_cinfo dki;
1631 struct dk_minfo dkm;
1632 struct dk_callback *dkc;
1633 int error = 0;
1634 rl_t *rl;
1635
1636 mutex_enter(&zfsdev_state_lock);
1637
1638 zv = zfsdev_get_soft_state(getminor(dev), ZSST_ZVOL);
1639
1640 if (zv == NULL) {
1641 mutex_exit(&zfsdev_state_lock);
1642 return (SET_ERROR(ENXIO));
1643 }
1644 ASSERT(zv->zv_total_opens > 0);
1645
1646 switch (cmd) {
1647
1648 case DKIOCINFO:
1649 bzero(&dki, sizeof (dki));
1650 (void) strcpy(dki.dki_cname, "zvol");
1651 (void) strcpy(dki.dki_dname, "zvol");
1652 dki.dki_ctype = DKC_UNKNOWN;
1653 dki.dki_unit = getminor(dev);
1654 dki.dki_maxtransfer = 1 << (SPA_MAXBLOCKSHIFT - zv->zv_min_bs);
1655 mutex_exit(&zfsdev_state_lock);
1656 if (ddi_copyout(&dki, (void *)arg, sizeof (dki), flag))
1657 error = SET_ERROR(EFAULT);
1658 return (error);
1659
1660 case DKIOCGMEDIAINFO:
1661 bzero(&dkm, sizeof (dkm));
1662 dkm.dki_lbsize = 1U << zv->zv_min_bs;
1663 dkm.dki_capacity = zv->zv_volsize >> zv->zv_min_bs;
1664 dkm.dki_media_type = DK_UNKNOWN;
1665 mutex_exit(&zfsdev_state_lock);
1666 if (ddi_copyout(&dkm, (void *)arg, sizeof (dkm), flag))
1667 error = SET_ERROR(EFAULT);
1668 return (error);
1669
1670 case DKIOCGETEFI:
1671 {
1672 uint64_t vs = zv->zv_volsize;
1673 uint8_t bs = zv->zv_min_bs;
1674
1675 mutex_exit(&zfsdev_state_lock);
1676 error = zvol_getefi((void *)arg, flag, vs, bs);
1677 return (error);
1678 }
1679
1680 case DKIOCFLUSHWRITECACHE:
1681 dkc = (struct dk_callback *)arg;
1682 mutex_exit(&zfsdev_state_lock);
1683 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1684 if ((flag & FKIOCTL) && dkc != NULL && dkc->dkc_callback) {
1685 (*dkc->dkc_callback)(dkc->dkc_cookie, error);
1686 error = 0;
1687 }
1688 return (error);
1689
1690 case DKIOCGETWCE:
1691 {
1692 int wce = (zv->zv_flags & ZVOL_WCE) ? 1 : 0;
1693 if (ddi_copyout(&wce, (void *)arg, sizeof (int),
1694 flag))
1695 error = SET_ERROR(EFAULT);
1696 break;
1697 }
1698 case DKIOCSETWCE:
1699 {
1700 int wce;
1701 if (ddi_copyin((void *)arg, &wce, sizeof (int),
1702 flag)) {
1703 error = SET_ERROR(EFAULT);
1704 break;
1705 }
1706 if (wce) {
1707 zv->zv_flags |= ZVOL_WCE;
1708 mutex_exit(&zfsdev_state_lock);
1709 } else {
1710 zv->zv_flags &= ~ZVOL_WCE;
1711 mutex_exit(&zfsdev_state_lock);
1712 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1713 }
1714 return (0);
1715 }
1716
1717 case DKIOCGGEOM:
1718 case DKIOCGVTOC:
1719 /*
1720 * commands using these (like prtvtoc) expect ENOTSUP
1721 * since we're emulating an EFI label
1722 */
1723 error = SET_ERROR(ENOTSUP);
1724 break;
1725
1726 case DKIOCDUMPINIT:
1727 rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize,
1728 RL_WRITER);
1729 error = zvol_dumpify(zv);
1730 zfs_range_unlock(rl);
1731 break;
1732
1733 case DKIOCDUMPFINI:
1734 if (!(zv->zv_flags & ZVOL_DUMPIFIED))
1735 break;
1736 rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize,
1737 RL_WRITER);
1738 error = zvol_dump_fini(zv);
1739 zfs_range_unlock(rl);
1740 break;
1741
1742 case DKIOCFREE:
1743 {
1744 dkioc_free_t df;
1745 dmu_tx_t *tx;
1746
1747 if (ddi_copyin((void *)arg, &df, sizeof (df), flag)) {
1748 error = SET_ERROR(EFAULT);
1749 break;
1750 }
1751
1752 /*
1753 * Apply Postel's Law to length-checking. If they overshoot,
1754 * just blank out until the end, if there's a need to blank
1755 * out anything.
1756 */
1757 if (df.df_start >= zv->zv_volsize)
1758 break; /* No need to do anything... */
1759 if (df.df_start + df.df_length > zv->zv_volsize)
1760 df.df_length = DMU_OBJECT_END;
1761
1762 rl = zfs_range_lock(&zv->zv_znode, df.df_start, df.df_length,
1763 RL_WRITER);
1764 tx = dmu_tx_create(zv->zv_objset);
1765 error = dmu_tx_assign(tx, TXG_WAIT);
1766 if (error != 0) {
1767 dmu_tx_abort(tx);
1768 } else {
1769 zvol_log_truncate(zv, tx, df.df_start,
1770 df.df_length, B_TRUE);
1771 dmu_tx_commit(tx);
1772 error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ,
1773 df.df_start, df.df_length);
1774 }
1775
1776 zfs_range_unlock(rl);
1777
1778 if (error == 0) {
1779 /*
1780 * If the write-cache is disabled or 'sync' property
1781 * is set to 'always' then treat this as a synchronous
1782 * operation (i.e. commit to zil).
1783 */
1784 if (!(zv->zv_flags & ZVOL_WCE) ||
1785 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS))
1786 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1787
1788 /*
1789 * If the caller really wants synchronous writes, and
1790 * can't wait for them, don't return until the write
1791 * is done.
1792 */
1793 if (df.df_flags & DF_WAIT_SYNC) {
1794 txg_wait_synced(
1795 dmu_objset_pool(zv->zv_objset), 0);
1796 }
1797 }
1798 break;
1799 }
1800
1801 default:
1802 error = SET_ERROR(ENOTTY);
1803 break;
1804
1805 }
1806 mutex_exit(&zfsdev_state_lock);
1807 return (error);
1808 }
1809
1810 int
1811 zvol_busy(void)
1812 {
1813 return (zvol_minors != 0);
1814 }
1815
1816 void
1817 zvol_init(void)
1818 {
1819 VERIFY(ddi_soft_state_init(&zfsdev_state, sizeof (zfs_soft_state_t),
1820 1) == 0);
1821 mutex_init(&zfsdev_state_lock, NULL, MUTEX_DEFAULT, NULL);
1822 }
1823
1824 void
1825 zvol_fini(void)
1826 {
1827 mutex_destroy(&zfsdev_state_lock);
1828 ddi_soft_state_fini(&zfsdev_state);
1829 }
1830
1831 /*ARGSUSED*/
1832 static int
1833 zfs_mvdev_dump_feature_check(void *arg, dmu_tx_t *tx)
1834 {
1835 spa_t *spa = dmu_tx_pool(tx)->dp_spa;
1836
1837 if (spa_feature_is_active(spa, SPA_FEATURE_MULTI_VDEV_CRASH_DUMP))
1838 return (1);
1839 return (0);
1840 }
1841
1842 /*ARGSUSED*/
1843 static void
1844 zfs_mvdev_dump_activate_feature_sync(void *arg, dmu_tx_t *tx)
1845 {
1846 spa_t *spa = dmu_tx_pool(tx)->dp_spa;
1847
1848 spa_feature_incr(spa, SPA_FEATURE_MULTI_VDEV_CRASH_DUMP, tx);
1849 }
1850
1851 static int
1852 zvol_dump_init(zvol_state_t *zv, boolean_t resize)
1853 {
1854 dmu_tx_t *tx;
1855 int error;
1856 objset_t *os = zv->zv_objset;
1857 spa_t *spa = dmu_objset_spa(os);
1858 vdev_t *vd = spa->spa_root_vdev;
1859 nvlist_t *nv = NULL;
1860 uint64_t version = spa_version(spa);
1861 enum zio_checksum checksum;
1862
1863 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
1864 ASSERT(vd->vdev_ops == &vdev_root_ops);
1865
1866 error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, 0,
1867 DMU_OBJECT_END);
1868 /* wait for dmu_free_long_range to actually free the blocks */
1869 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
1870
1871 /*
1872 * If the pool on which the dump device is being initialized has more
1873 * than one child vdev, check that the MULTI_VDEV_CRASH_DUMP feature is
1874 * enabled. If so, bump that feature's counter to indicate that the
1875 * feature is active. We also check the vdev type to handle the
1876 * following case:
1877 * # zpool create test raidz disk1 disk2 disk3
1878 * Now have spa_root_vdev->vdev_children == 1 (the raidz vdev),
1879 * the raidz vdev itself has 3 children.
1880 */
1881 if (vd->vdev_children > 1 || vd->vdev_ops == &vdev_raidz_ops) {
1882 if (!spa_feature_is_enabled(spa,
1883 SPA_FEATURE_MULTI_VDEV_CRASH_DUMP))
1884 return (SET_ERROR(ENOTSUP));
1885 (void) dsl_sync_task(spa_name(spa),
1886 zfs_mvdev_dump_feature_check,
1887 zfs_mvdev_dump_activate_feature_sync, NULL, 2);
1888 }
1889
1890 tx = dmu_tx_create(os);
1891 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
1892 dmu_tx_hold_bonus(tx, ZVOL_OBJ);
1893 error = dmu_tx_assign(tx, TXG_WAIT);
1894 if (error) {
1895 dmu_tx_abort(tx);
1896 return (error);
1897 }
1898
1899 /*
1900 * If MULTI_VDEV_CRASH_DUMP is active, use the NOPARITY checksum
1901 * function. Otherwise, use the old default -- OFF.
1902 */
1903 checksum = spa_feature_is_active(spa,
1904 SPA_FEATURE_MULTI_VDEV_CRASH_DUMP) ? ZIO_CHECKSUM_NOPARITY :
1905 ZIO_CHECKSUM_OFF;
1906
1907 /*
1908 * If we are resizing the dump device then we only need to
1909 * update the refreservation to match the newly updated
1910 * zvolsize. Otherwise, we save off the original state of the
1911 * zvol so that we can restore them if the zvol is ever undumpified.
1912 */
1913 if (resize) {
1914 error = zap_update(os, ZVOL_ZAP_OBJ,
1915 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1,
1916 &zv->zv_volsize, tx);
1917 } else {
1918 uint64_t checksum, compress, refresrv, vbs, dedup;
1919
1920 error = dsl_prop_get_integer(zv->zv_name,
1921 zfs_prop_to_name(ZFS_PROP_COMPRESSION), &compress, NULL);
1922 error = error ? error : dsl_prop_get_integer(zv->zv_name,
1923 zfs_prop_to_name(ZFS_PROP_CHECKSUM), &checksum, NULL);
1924 error = error ? error : dsl_prop_get_integer(zv->zv_name,
1925 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), &refresrv, NULL);
1926 error = error ? error : dsl_prop_get_integer(zv->zv_name,
1927 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &vbs, NULL);
1928 if (version >= SPA_VERSION_DEDUP) {
1929 error = error ? error :
1930 dsl_prop_get_integer(zv->zv_name,
1931 zfs_prop_to_name(ZFS_PROP_DEDUP), &dedup, NULL);
1932 }
1933
1934 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ,
1935 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1,
1936 &compress, tx);
1937 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ,
1938 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1, &checksum, tx);
1939 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ,
1940 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1,
1941 &refresrv, tx);
1942 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ,
1943 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1,
1944 &vbs, tx);
1945 error = error ? error : dmu_object_set_blocksize(
1946 os, ZVOL_OBJ, SPA_MAXBLOCKSIZE, 0, tx);
1947 if (version >= SPA_VERSION_DEDUP) {
1948 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ,
1949 zfs_prop_to_name(ZFS_PROP_DEDUP), 8, 1,
1950 &dedup, tx);
1951 }
1952 if (error == 0)
1953 zv->zv_volblocksize = SPA_MAXBLOCKSIZE;
1954 }
1955 dmu_tx_commit(tx);
1956
1957 /*
1958 * We only need update the zvol's property if we are initializing
1959 * the dump area for the first time.
1960 */
1961 if (!resize) {
1962 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
1963 VERIFY(nvlist_add_uint64(nv,
1964 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 0) == 0);
1965 VERIFY(nvlist_add_uint64(nv,
1966 zfs_prop_to_name(ZFS_PROP_COMPRESSION),
1967 ZIO_COMPRESS_OFF) == 0);
1968 VERIFY(nvlist_add_uint64(nv,
1969 zfs_prop_to_name(ZFS_PROP_CHECKSUM),
1970 checksum) == 0);
1971 if (version >= SPA_VERSION_DEDUP) {
1972 VERIFY(nvlist_add_uint64(nv,
1973 zfs_prop_to_name(ZFS_PROP_DEDUP),
1974 ZIO_CHECKSUM_OFF) == 0);
1975 }
1976
1977 error = zfs_set_prop_nvlist(zv->zv_name, ZPROP_SRC_LOCAL,
1978 nv, NULL);
1979 nvlist_free(nv);
1980
1981 if (error)
1982 return (error);
1983 }
1984
1985 /* Allocate the space for the dump */
1986 error = zvol_prealloc(zv);
1987 return (error);
1988 }
1989
1990 static int
1991 zvol_dumpify(zvol_state_t *zv)
1992 {
1993 int error = 0;
1994 uint64_t dumpsize = 0;
1995 dmu_tx_t *tx;
1996 objset_t *os = zv->zv_objset;
1997
1998 if (zv->zv_flags & ZVOL_RDONLY)
1999 return (SET_ERROR(EROFS));
2000
2001 if (zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE,
2002 8, 1, &dumpsize) != 0 || dumpsize != zv->zv_volsize) {
2003 boolean_t resize = (dumpsize > 0);
2004
2005 if ((error = zvol_dump_init(zv, resize)) != 0) {
2006 (void) zvol_dump_fini(zv);
2007 return (error);
2008 }
2009 }
2010
2011 /*
2012 * Build up our lba mapping.
2013 */
2014 error = zvol_get_lbas(zv);
2015 if (error) {
2016 (void) zvol_dump_fini(zv);
2017 return (error);
2018 }
2019
2020 tx = dmu_tx_create(os);
2021 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
2022 error = dmu_tx_assign(tx, TXG_WAIT);
2023 if (error) {
2024 dmu_tx_abort(tx);
2025 (void) zvol_dump_fini(zv);
2026 return (error);
2027 }
2028
2029 zv->zv_flags |= ZVOL_DUMPIFIED;
2030 error = zap_update(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, 8, 1,
2031 &zv->zv_volsize, tx);
2032 dmu_tx_commit(tx);
2033
2034 if (error) {
2035 (void) zvol_dump_fini(zv);
2036 return (error);
2037 }
2038
2039 txg_wait_synced(dmu_objset_pool(os), 0);
2040 return (0);
2041 }
2042
2043 static int
2044 zvol_dump_fini(zvol_state_t *zv)
2045 {
2046 dmu_tx_t *tx;
2047 objset_t *os = zv->zv_objset;
2048 nvlist_t *nv;
2049 int error = 0;
2050 uint64_t checksum, compress, refresrv, vbs, dedup;
2051 uint64_t version = spa_version(dmu_objset_spa(zv->zv_objset));
2052
2053 /*
2054 * Attempt to restore the zvol back to its pre-dumpified state.
2055 * This is a best-effort attempt as it's possible that not all
2056 * of these properties were initialized during the dumpify process
2057 * (i.e. error during zvol_dump_init).
2058 */
2059
2060 tx = dmu_tx_create(os);
2061 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
2062 error = dmu_tx_assign(tx, TXG_WAIT);
2063 if (error) {
2064 dmu_tx_abort(tx);
2065 return (error);
2066 }
2067 (void) zap_remove(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, tx);
2068 dmu_tx_commit(tx);
2069
2070 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2071 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1, &checksum);
2072 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2073 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1, &compress);
2074 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2075 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, &refresrv);
2076 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2077 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1, &vbs);
2078
2079 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2080 (void) nvlist_add_uint64(nv,
2081 zfs_prop_to_name(ZFS_PROP_CHECKSUM), checksum);
2082 (void) nvlist_add_uint64(nv,
2083 zfs_prop_to_name(ZFS_PROP_COMPRESSION), compress);
2084 (void) nvlist_add_uint64(nv,
2085 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), refresrv);
2086 if (version >= SPA_VERSION_DEDUP &&
2087 zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2088 zfs_prop_to_name(ZFS_PROP_DEDUP), 8, 1, &dedup) == 0) {
2089 (void) nvlist_add_uint64(nv,
2090 zfs_prop_to_name(ZFS_PROP_DEDUP), dedup);
2091 }
2092 (void) zfs_set_prop_nvlist(zv->zv_name, ZPROP_SRC_LOCAL,
2093 nv, NULL);
2094 nvlist_free(nv);
2095
2096 zvol_free_extents(zv);
2097 zv->zv_flags &= ~ZVOL_DUMPIFIED;
2098 (void) dmu_free_long_range(os, ZVOL_OBJ, 0, DMU_OBJECT_END);
2099 /* wait for dmu_free_long_range to actually free the blocks */
2100 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
2101 tx = dmu_tx_create(os);
2102 dmu_tx_hold_bonus(tx, ZVOL_OBJ);
2103 error = dmu_tx_assign(tx, TXG_WAIT);
2104 if (error) {
2105 dmu_tx_abort(tx);
2106 return (error);
2107 }
2108 if (dmu_object_set_blocksize(os, ZVOL_OBJ, vbs, 0, tx) == 0)
2109 zv->zv_volblocksize = vbs;
2110 dmu_tx_commit(tx);
2111
2112 return (0);
2113 }