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5960 zfs recv should prefetch indirect blocks
[illumos-gate.git] / usr / src / uts / common / fs / zfs / zvol.c
blob101566a1ea55e86af6c070af6a3befd84493e42d
1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 *
24 * Portions Copyright 2010 Robert Milkowski
25 *
26 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
27 * Copyright (c) 2012, 2014 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 /*
146 * Toggle unmap functionality.
147 */
148 boolean_t zvol_unmap_enabled = B_TRUE;
149
150 extern int zfs_set_prop_nvlist(const char *, zprop_source_t,
151 nvlist_t *, nvlist_t *);
152 static int zvol_remove_zv(zvol_state_t *);
153 static int zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio);
154 static int zvol_dumpify(zvol_state_t *zv);
155 static int zvol_dump_fini(zvol_state_t *zv);
156 static int zvol_dump_init(zvol_state_t *zv, boolean_t resize);
157
158 static void
159 zvol_size_changed(zvol_state_t *zv, uint64_t volsize)
160 {
161 dev_t dev = makedevice(ddi_driver_major(zfs_dip), zv->zv_minor);
162
163 zv->zv_volsize = volsize;
164 VERIFY(ddi_prop_update_int64(dev, zfs_dip,
165 "Size", volsize) == DDI_SUCCESS);
166 VERIFY(ddi_prop_update_int64(dev, zfs_dip,
167 "Nblocks", lbtodb(volsize)) == DDI_SUCCESS);
168
169 /* Notify specfs to invalidate the cached size */
170 spec_size_invalidate(dev, VBLK);
171 spec_size_invalidate(dev, VCHR);
172 }
173
174 int
175 zvol_check_volsize(uint64_t volsize, uint64_t blocksize)
176 {
177 if (volsize == 0)
178 return (SET_ERROR(EINVAL));
179
180 if (volsize % blocksize != 0)
181 return (SET_ERROR(EINVAL));
182
183 #ifdef _ILP32
184 if (volsize - 1 > SPEC_MAXOFFSET_T)
185 return (SET_ERROR(EOVERFLOW));
186 #endif
187 return (0);
188 }
189
190 int
191 zvol_check_volblocksize(uint64_t volblocksize)
192 {
193 if (volblocksize < SPA_MINBLOCKSIZE ||
194 volblocksize > SPA_OLD_MAXBLOCKSIZE ||
195 !ISP2(volblocksize))
196 return (SET_ERROR(EDOM));
197
198 return (0);
199 }
200
201 int
202 zvol_get_stats(objset_t *os, nvlist_t *nv)
203 {
204 int error;
205 dmu_object_info_t doi;
206 uint64_t val;
207
208 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &val);
209 if (error)
210 return (error);
211
212 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLSIZE, val);
213
214 error = dmu_object_info(os, ZVOL_OBJ, &doi);
215
216 if (error == 0) {
217 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLBLOCKSIZE,
218 doi.doi_data_block_size);
219 }
220
221 return (error);
222 }
223
224 static zvol_state_t *
225 zvol_minor_lookup(const char *name)
226 {
227 minor_t minor;
228 zvol_state_t *zv;
229
230 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
231
232 for (minor = 1; minor <= ZFSDEV_MAX_MINOR; minor++) {
233 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
234 if (zv == NULL)
235 continue;
236 if (strcmp(zv->zv_name, name) == 0)
237 return (zv);
238 }
239
240 return (NULL);
241 }
242
243 /* extent mapping arg */
244 struct maparg {
245 zvol_state_t *ma_zv;
246 uint64_t ma_blks;
247 };
248
249 /*ARGSUSED*/
250 static int
251 zvol_map_block(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
252 const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
253 {
254 struct maparg *ma = arg;
255 zvol_extent_t *ze;
256 int bs = ma->ma_zv->zv_volblocksize;
257
258 if (bp == NULL || BP_IS_HOLE(bp) ||
259 zb->zb_object != ZVOL_OBJ || zb->zb_level != 0)
260 return (0);
261
262 VERIFY(!BP_IS_EMBEDDED(bp));
263
264 VERIFY3U(ma->ma_blks, ==, zb->zb_blkid);
265 ma->ma_blks++;
266
267 /* Abort immediately if we have encountered gang blocks */
268 if (BP_IS_GANG(bp))
269 return (SET_ERROR(EFRAGS));
270
271 /*
272 * See if the block is at the end of the previous extent.
273 */
274 ze = list_tail(&ma->ma_zv->zv_extents);
275 if (ze &&
276 DVA_GET_VDEV(BP_IDENTITY(bp)) == DVA_GET_VDEV(&ze->ze_dva) &&
277 DVA_GET_OFFSET(BP_IDENTITY(bp)) ==
278 DVA_GET_OFFSET(&ze->ze_dva) + ze->ze_nblks * bs) {
279 ze->ze_nblks++;
280 return (0);
281 }
282
283 dprintf_bp(bp, "%s", "next blkptr:");
284
285 /* start a new extent */
286 ze = kmem_zalloc(sizeof (zvol_extent_t), KM_SLEEP);
287 ze->ze_dva = bp->blk_dva[0]; /* structure assignment */
288 ze->ze_nblks = 1;
289 list_insert_tail(&ma->ma_zv->zv_extents, ze);
290 return (0);
291 }
292
293 static void
294 zvol_free_extents(zvol_state_t *zv)
295 {
296 zvol_extent_t *ze;
297
298 while (ze = list_head(&zv->zv_extents)) {
299 list_remove(&zv->zv_extents, ze);
300 kmem_free(ze, sizeof (zvol_extent_t));
301 }
302 }
303
304 static int
305 zvol_get_lbas(zvol_state_t *zv)
306 {
307 objset_t *os = zv->zv_objset;
308 struct maparg ma;
309 int err;
310
311 ma.ma_zv = zv;
312 ma.ma_blks = 0;
313 zvol_free_extents(zv);
314
315 /* commit any in-flight changes before traversing the dataset */
316 txg_wait_synced(dmu_objset_pool(os), 0);
317 err = traverse_dataset(dmu_objset_ds(os), 0,
318 TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA, zvol_map_block, &ma);
319 if (err || ma.ma_blks != (zv->zv_volsize / zv->zv_volblocksize)) {
320 zvol_free_extents(zv);
321 return (err ? err : EIO);
322 }
323
324 return (0);
325 }
326
327 /* ARGSUSED */
328 void
329 zvol_create_cb(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx)
330 {
331 zfs_creat_t *zct = arg;
332 nvlist_t *nvprops = zct->zct_props;
333 int error;
334 uint64_t volblocksize, volsize;
335
336 VERIFY(nvlist_lookup_uint64(nvprops,
337 zfs_prop_to_name(ZFS_PROP_VOLSIZE), &volsize) == 0);
338 if (nvlist_lookup_uint64(nvprops,
339 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &volblocksize) != 0)
340 volblocksize = zfs_prop_default_numeric(ZFS_PROP_VOLBLOCKSIZE);
341
342 /*
343 * These properties must be removed from the list so the generic
344 * property setting step won't apply to them.
345 */
346 VERIFY(nvlist_remove_all(nvprops,
347 zfs_prop_to_name(ZFS_PROP_VOLSIZE)) == 0);
348 (void) nvlist_remove_all(nvprops,
349 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE));
350
351 error = dmu_object_claim(os, ZVOL_OBJ, DMU_OT_ZVOL, volblocksize,
352 DMU_OT_NONE, 0, tx);
353 ASSERT(error == 0);
354
355 error = zap_create_claim(os, ZVOL_ZAP_OBJ, DMU_OT_ZVOL_PROP,
356 DMU_OT_NONE, 0, tx);
357 ASSERT(error == 0);
358
359 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize, tx);
360 ASSERT(error == 0);
361 }
362
363 /*
364 * Replay a TX_TRUNCATE ZIL transaction if asked. TX_TRUNCATE is how we
365 * implement DKIOCFREE/free-long-range.
366 */
367 static int
368 zvol_replay_truncate(zvol_state_t *zv, lr_truncate_t *lr, boolean_t byteswap)
369 {
370 uint64_t offset, length;
371
372 if (byteswap)
373 byteswap_uint64_array(lr, sizeof (*lr));
374
375 offset = lr->lr_offset;
376 length = lr->lr_length;
377
378 return (dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, offset, length));
379 }
380
381 /*
382 * Replay a TX_WRITE ZIL transaction that didn't get committed
383 * after a system failure
384 */
385 static int
386 zvol_replay_write(zvol_state_t *zv, lr_write_t *lr, boolean_t byteswap)
387 {
388 objset_t *os = zv->zv_objset;
389 char *data = (char *)(lr + 1); /* data follows lr_write_t */
390 uint64_t offset, length;
391 dmu_tx_t *tx;
392 int error;
393
394 if (byteswap)
395 byteswap_uint64_array(lr, sizeof (*lr));
396
397 offset = lr->lr_offset;
398 length = lr->lr_length;
399
400 /* If it's a dmu_sync() block, write the whole block */
401 if (lr->lr_common.lrc_reclen == sizeof (lr_write_t)) {
402 uint64_t blocksize = BP_GET_LSIZE(&lr->lr_blkptr);
403 if (length < blocksize) {
404 offset -= offset % blocksize;
405 length = blocksize;
406 }
407 }
408
409 tx = dmu_tx_create(os);
410 dmu_tx_hold_write(tx, ZVOL_OBJ, offset, length);
411 error = dmu_tx_assign(tx, TXG_WAIT);
412 if (error) {
413 dmu_tx_abort(tx);
414 } else {
415 dmu_write(os, ZVOL_OBJ, offset, length, data, tx);
416 dmu_tx_commit(tx);
417 }
418
419 return (error);
420 }
421
422 /* ARGSUSED */
423 static int
424 zvol_replay_err(zvol_state_t *zv, lr_t *lr, boolean_t byteswap)
425 {
426 return (SET_ERROR(ENOTSUP));
427 }
428
429 /*
430 * Callback vectors for replaying records.
431 * Only TX_WRITE and TX_TRUNCATE are needed for zvol.
432 */
433 zil_replay_func_t *zvol_replay_vector[TX_MAX_TYPE] = {
434 zvol_replay_err, /* 0 no such transaction type */
435 zvol_replay_err, /* TX_CREATE */
436 zvol_replay_err, /* TX_MKDIR */
437 zvol_replay_err, /* TX_MKXATTR */
438 zvol_replay_err, /* TX_SYMLINK */
439 zvol_replay_err, /* TX_REMOVE */
440 zvol_replay_err, /* TX_RMDIR */
441 zvol_replay_err, /* TX_LINK */
442 zvol_replay_err, /* TX_RENAME */
443 zvol_replay_write, /* TX_WRITE */
444 zvol_replay_truncate, /* TX_TRUNCATE */
445 zvol_replay_err, /* TX_SETATTR */
446 zvol_replay_err, /* TX_ACL */
447 zvol_replay_err, /* TX_CREATE_ACL */
448 zvol_replay_err, /* TX_CREATE_ATTR */
449 zvol_replay_err, /* TX_CREATE_ACL_ATTR */
450 zvol_replay_err, /* TX_MKDIR_ACL */
451 zvol_replay_err, /* TX_MKDIR_ATTR */
452 zvol_replay_err, /* TX_MKDIR_ACL_ATTR */
453 zvol_replay_err, /* TX_WRITE2 */
454 };
455
456 int
457 zvol_name2minor(const char *name, minor_t *minor)
458 {
459 zvol_state_t *zv;
460
461 mutex_enter(&zfsdev_state_lock);
462 zv = zvol_minor_lookup(name);
463 if (minor && zv)
464 *minor = zv->zv_minor;
465 mutex_exit(&zfsdev_state_lock);
466 return (zv ? 0 : -1);
467 }
468
469 /*
470 * Create a minor node (plus a whole lot more) for the specified volume.
471 */
472 int
473 zvol_create_minor(const char *name)
474 {
475 zfs_soft_state_t *zs;
476 zvol_state_t *zv;
477 objset_t *os;
478 dmu_object_info_t doi;
479 minor_t minor = 0;
480 char chrbuf[30], blkbuf[30];
481 int error;
482
483 mutex_enter(&zfsdev_state_lock);
484
485 if (zvol_minor_lookup(name) != NULL) {
486 mutex_exit(&zfsdev_state_lock);
487 return (SET_ERROR(EEXIST));
488 }
489
490 /* lie and say we're read-only */
491 error = dmu_objset_own(name, DMU_OST_ZVOL, B_TRUE, FTAG, &os);
492
493 if (error) {
494 mutex_exit(&zfsdev_state_lock);
495 return (error);
496 }
497
498 if ((minor = zfsdev_minor_alloc()) == 0) {
499 dmu_objset_disown(os, FTAG);
500 mutex_exit(&zfsdev_state_lock);
501 return (SET_ERROR(ENXIO));
502 }
503
504 if (ddi_soft_state_zalloc(zfsdev_state, minor) != DDI_SUCCESS) {
505 dmu_objset_disown(os, FTAG);
506 mutex_exit(&zfsdev_state_lock);
507 return (SET_ERROR(EAGAIN));
508 }
509 (void) ddi_prop_update_string(minor, zfs_dip, ZVOL_PROP_NAME,
510 (char *)name);
511
512 (void) snprintf(chrbuf, sizeof (chrbuf), "%u,raw", minor);
513
514 if (ddi_create_minor_node(zfs_dip, chrbuf, S_IFCHR,
515 minor, DDI_PSEUDO, 0) == DDI_FAILURE) {
516 ddi_soft_state_free(zfsdev_state, minor);
517 dmu_objset_disown(os, FTAG);
518 mutex_exit(&zfsdev_state_lock);
519 return (SET_ERROR(EAGAIN));
520 }
521
522 (void) snprintf(blkbuf, sizeof (blkbuf), "%u", minor);
523
524 if (ddi_create_minor_node(zfs_dip, blkbuf, S_IFBLK,
525 minor, DDI_PSEUDO, 0) == DDI_FAILURE) {
526 ddi_remove_minor_node(zfs_dip, chrbuf);
527 ddi_soft_state_free(zfsdev_state, minor);
528 dmu_objset_disown(os, FTAG);
529 mutex_exit(&zfsdev_state_lock);
530 return (SET_ERROR(EAGAIN));
531 }
532
533 zs = ddi_get_soft_state(zfsdev_state, minor);
534 zs->zss_type = ZSST_ZVOL;
535 zv = zs->zss_data = kmem_zalloc(sizeof (zvol_state_t), KM_SLEEP);
536 (void) strlcpy(zv->zv_name, name, MAXPATHLEN);
537 zv->zv_min_bs = DEV_BSHIFT;
538 zv->zv_minor = minor;
539 zv->zv_objset = os;
540 if (dmu_objset_is_snapshot(os) || !spa_writeable(dmu_objset_spa(os)))
541 zv->zv_flags |= ZVOL_RDONLY;
542 mutex_init(&zv->zv_znode.z_range_lock, NULL, MUTEX_DEFAULT, NULL);
543 avl_create(&zv->zv_znode.z_range_avl, zfs_range_compare,
544 sizeof (rl_t), offsetof(rl_t, r_node));
545 list_create(&zv->zv_extents, sizeof (zvol_extent_t),
546 offsetof(zvol_extent_t, ze_node));
547 /* get and cache the blocksize */
548 error = dmu_object_info(os, ZVOL_OBJ, &doi);
549 ASSERT(error == 0);
550 zv->zv_volblocksize = doi.doi_data_block_size;
551
552 if (spa_writeable(dmu_objset_spa(os))) {
553 if (zil_replay_disable)
554 zil_destroy(dmu_objset_zil(os), B_FALSE);
555 else
556 zil_replay(os, zv, zvol_replay_vector);
557 }
558 dmu_objset_disown(os, FTAG);
559 zv->zv_objset = NULL;
560
561 zvol_minors++;
562
563 mutex_exit(&zfsdev_state_lock);
564
565 return (0);
566 }
567
568 /*
569 * Remove minor node for the specified volume.
570 */
571 static int
572 zvol_remove_zv(zvol_state_t *zv)
573 {
574 char nmbuf[20];
575 minor_t minor = zv->zv_minor;
576
577 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
578 if (zv->zv_total_opens != 0)
579 return (SET_ERROR(EBUSY));
580
581 (void) snprintf(nmbuf, sizeof (nmbuf), "%u,raw", minor);
582 ddi_remove_minor_node(zfs_dip, nmbuf);
583
584 (void) snprintf(nmbuf, sizeof (nmbuf), "%u", minor);
585 ddi_remove_minor_node(zfs_dip, nmbuf);
586
587 avl_destroy(&zv->zv_znode.z_range_avl);
588 mutex_destroy(&zv->zv_znode.z_range_lock);
589
590 kmem_free(zv, sizeof (zvol_state_t));
591
592 ddi_soft_state_free(zfsdev_state, minor);
593
594 zvol_minors--;
595 return (0);
596 }
597
598 int
599 zvol_remove_minor(const char *name)
600 {
601 zvol_state_t *zv;
602 int rc;
603
604 mutex_enter(&zfsdev_state_lock);
605 if ((zv = zvol_minor_lookup(name)) == NULL) {
606 mutex_exit(&zfsdev_state_lock);
607 return (SET_ERROR(ENXIO));
608 }
609 rc = zvol_remove_zv(zv);
610 mutex_exit(&zfsdev_state_lock);
611 return (rc);
612 }
613
614 int
615 zvol_first_open(zvol_state_t *zv)
616 {
617 objset_t *os;
618 uint64_t volsize;
619 int error;
620 uint64_t readonly;
621
622 /* lie and say we're read-only */
623 error = dmu_objset_own(zv->zv_name, DMU_OST_ZVOL, B_TRUE,
624 zvol_tag, &os);
625 if (error)
626 return (error);
627
628 zv->zv_objset = os;
629 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize);
630 if (error) {
631 ASSERT(error == 0);
632 dmu_objset_disown(os, zvol_tag);
633 return (error);
634 }
635
636 error = dmu_bonus_hold(os, ZVOL_OBJ, zvol_tag, &zv->zv_dbuf);
637 if (error) {
638 dmu_objset_disown(os, zvol_tag);
639 return (error);
640 }
641
642 zvol_size_changed(zv, volsize);
643 zv->zv_zilog = zil_open(os, zvol_get_data);
644
645 VERIFY(dsl_prop_get_integer(zv->zv_name, "readonly", &readonly,
646 NULL) == 0);
647 if (readonly || dmu_objset_is_snapshot(os) ||
648 !spa_writeable(dmu_objset_spa(os)))
649 zv->zv_flags |= ZVOL_RDONLY;
650 else
651 zv->zv_flags &= ~ZVOL_RDONLY;
652 return (error);
653 }
654
655 void
656 zvol_last_close(zvol_state_t *zv)
657 {
658 zil_close(zv->zv_zilog);
659 zv->zv_zilog = NULL;
660
661 dmu_buf_rele(zv->zv_dbuf, zvol_tag);
662 zv->zv_dbuf = NULL;
663
664 /*
665 * Evict cached data
666 */
667 if (dsl_dataset_is_dirty(dmu_objset_ds(zv->zv_objset)) &&
668 !(zv->zv_flags & ZVOL_RDONLY))
669 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
670 dmu_objset_evict_dbufs(zv->zv_objset);
671
672 dmu_objset_disown(zv->zv_objset, zvol_tag);
673 zv->zv_objset = NULL;
674 }
675
676 int
677 zvol_prealloc(zvol_state_t *zv)
678 {
679 objset_t *os = zv->zv_objset;
680 dmu_tx_t *tx;
681 uint64_t refd, avail, usedobjs, availobjs;
682 uint64_t resid = zv->zv_volsize;
683 uint64_t off = 0;
684
685 /* Check the space usage before attempting to allocate the space */
686 dmu_objset_space(os, &refd, &avail, &usedobjs, &availobjs);
687 if (avail < zv->zv_volsize)
688 return (SET_ERROR(ENOSPC));
689
690 /* Free old extents if they exist */
691 zvol_free_extents(zv);
692
693 while (resid != 0) {
694 int error;
695 uint64_t bytes = MIN(resid, SPA_OLD_MAXBLOCKSIZE);
696
697 tx = dmu_tx_create(os);
698 dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes);
699 error = dmu_tx_assign(tx, TXG_WAIT);
700 if (error) {
701 dmu_tx_abort(tx);
702 (void) dmu_free_long_range(os, ZVOL_OBJ, 0, off);
703 return (error);
704 }
705 dmu_prealloc(os, ZVOL_OBJ, off, bytes, tx);
706 dmu_tx_commit(tx);
707 off += bytes;
708 resid -= bytes;
709 }
710 txg_wait_synced(dmu_objset_pool(os), 0);
711
712 return (0);
713 }
714
715 static int
716 zvol_update_volsize(objset_t *os, uint64_t volsize)
717 {
718 dmu_tx_t *tx;
719 int error;
720
721 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
722
723 tx = dmu_tx_create(os);
724 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
725 dmu_tx_mark_netfree(tx);
726 error = dmu_tx_assign(tx, TXG_WAIT);
727 if (error) {
728 dmu_tx_abort(tx);
729 return (error);
730 }
731
732 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1,
733 &volsize, tx);
734 dmu_tx_commit(tx);
735
736 if (error == 0)
737 error = dmu_free_long_range(os,
738 ZVOL_OBJ, volsize, DMU_OBJECT_END);
739 return (error);
740 }
741
742 void
743 zvol_remove_minors(const char *name)
744 {
745 zvol_state_t *zv;
746 char *namebuf;
747 minor_t minor;
748
749 namebuf = kmem_zalloc(strlen(name) + 2, KM_SLEEP);
750 (void) strncpy(namebuf, name, strlen(name));
751 (void) strcat(namebuf, "/");
752 mutex_enter(&zfsdev_state_lock);
753 for (minor = 1; minor <= ZFSDEV_MAX_MINOR; minor++) {
754
755 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
756 if (zv == NULL)
757 continue;
758 if (strncmp(namebuf, zv->zv_name, strlen(namebuf)) == 0)
759 (void) zvol_remove_zv(zv);
760 }
761 kmem_free(namebuf, strlen(name) + 2);
762
763 mutex_exit(&zfsdev_state_lock);
764 }
765
766 static int
767 zvol_update_live_volsize(zvol_state_t *zv, uint64_t volsize)
768 {
769 uint64_t old_volsize = 0ULL;
770 int error = 0;
771
772 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
773
774 /*
775 * Reinitialize the dump area to the new size. If we
776 * failed to resize the dump area then restore it back to
777 * its original size. We must set the new volsize prior
778 * to calling dumpvp_resize() to ensure that the devices'
779 * size(9P) is not visible by the dump subsystem.
780 */
781 old_volsize = zv->zv_volsize;
782 zvol_size_changed(zv, volsize);
783
784 if (zv->zv_flags & ZVOL_DUMPIFIED) {
785 if ((error = zvol_dumpify(zv)) != 0 ||
786 (error = dumpvp_resize()) != 0) {
787 int dumpify_error;
788
789 (void) zvol_update_volsize(zv->zv_objset, old_volsize);
790 zvol_size_changed(zv, old_volsize);
791 dumpify_error = zvol_dumpify(zv);
792 error = dumpify_error ? dumpify_error : error;
793 }
794 }
795
796 /*
797 * Generate a LUN expansion event.
798 */
799 if (error == 0) {
800 sysevent_id_t eid;
801 nvlist_t *attr;
802 char *physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
803
804 (void) snprintf(physpath, MAXPATHLEN, "%s%u", ZVOL_PSEUDO_DEV,
805 zv->zv_minor);
806
807 VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0);
808 VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0);
809
810 (void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS,
811 ESC_DEV_DLE, attr, &eid, DDI_SLEEP);
812
813 nvlist_free(attr);
814 kmem_free(physpath, MAXPATHLEN);
815 }
816 return (error);
817 }
818
819 int
820 zvol_set_volsize(const char *name, uint64_t volsize)
821 {
822 zvol_state_t *zv = NULL;
823 objset_t *os;
824 int error;
825 dmu_object_info_t doi;
826 uint64_t readonly;
827 boolean_t owned = B_FALSE;
828
829 error = dsl_prop_get_integer(name,
830 zfs_prop_to_name(ZFS_PROP_READONLY), &readonly, NULL);
831 if (error != 0)
832 return (error);
833 if (readonly)
834 return (SET_ERROR(EROFS));
835
836 mutex_enter(&zfsdev_state_lock);
837 zv = zvol_minor_lookup(name);
838
839 if (zv == NULL || zv->zv_objset == NULL) {
840 if ((error = dmu_objset_own(name, DMU_OST_ZVOL, B_FALSE,
841 FTAG, &os)) != 0) {
842 mutex_exit(&zfsdev_state_lock);
843 return (error);
844 }
845 owned = B_TRUE;
846 if (zv != NULL)
847 zv->zv_objset = os;
848 } else {
849 os = zv->zv_objset;
850 }
851
852 if ((error = dmu_object_info(os, ZVOL_OBJ, &doi)) != 0 ||
853 (error = zvol_check_volsize(volsize, doi.doi_data_block_size)) != 0)
854 goto out;
855
856 error = zvol_update_volsize(os, volsize);
857
858 if (error == 0 && zv != NULL)
859 error = zvol_update_live_volsize(zv, volsize);
860 out:
861 if (owned) {
862 dmu_objset_disown(os, FTAG);
863 if (zv != NULL)
864 zv->zv_objset = NULL;
865 }
866 mutex_exit(&zfsdev_state_lock);
867 return (error);
868 }
869
870 /*ARGSUSED*/
871 int
872 zvol_open(dev_t *devp, int flag, int otyp, cred_t *cr)
873 {
874 zvol_state_t *zv;
875 int err = 0;
876
877 mutex_enter(&zfsdev_state_lock);
878
879 zv = zfsdev_get_soft_state(getminor(*devp), ZSST_ZVOL);
880 if (zv == NULL) {
881 mutex_exit(&zfsdev_state_lock);
882 return (SET_ERROR(ENXIO));
883 }
884
885 if (zv->zv_total_opens == 0)
886 err = zvol_first_open(zv);
887 if (err) {
888 mutex_exit(&zfsdev_state_lock);
889 return (err);
890 }
891 if ((flag & FWRITE) && (zv->zv_flags & ZVOL_RDONLY)) {
892 err = SET_ERROR(EROFS);
893 goto out;
894 }
895 if (zv->zv_flags & ZVOL_EXCL) {
896 err = SET_ERROR(EBUSY);
897 goto out;
898 }
899 if (flag & FEXCL) {
900 if (zv->zv_total_opens != 0) {
901 err = SET_ERROR(EBUSY);
902 goto out;
903 }
904 zv->zv_flags |= ZVOL_EXCL;
905 }
906
907 if (zv->zv_open_count[otyp] == 0 || otyp == OTYP_LYR) {
908 zv->zv_open_count[otyp]++;
909 zv->zv_total_opens++;
910 }
911 mutex_exit(&zfsdev_state_lock);
912
913 return (err);
914 out:
915 if (zv->zv_total_opens == 0)
916 zvol_last_close(zv);
917 mutex_exit(&zfsdev_state_lock);
918 return (err);
919 }
920
921 /*ARGSUSED*/
922 int
923 zvol_close(dev_t dev, int flag, int otyp, cred_t *cr)
924 {
925 minor_t minor = getminor(dev);
926 zvol_state_t *zv;
927 int error = 0;
928
929 mutex_enter(&zfsdev_state_lock);
930
931 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
932 if (zv == NULL) {
933 mutex_exit(&zfsdev_state_lock);
934 return (SET_ERROR(ENXIO));
935 }
936
937 if (zv->zv_flags & ZVOL_EXCL) {
938 ASSERT(zv->zv_total_opens == 1);
939 zv->zv_flags &= ~ZVOL_EXCL;
940 }
941
942 /*
943 * If the open count is zero, this is a spurious close.
944 * That indicates a bug in the kernel / DDI framework.
945 */
946 ASSERT(zv->zv_open_count[otyp] != 0);
947 ASSERT(zv->zv_total_opens != 0);
948
949 /*
950 * You may get multiple opens, but only one close.
951 */
952 zv->zv_open_count[otyp]--;
953 zv->zv_total_opens--;
954
955 if (zv->zv_total_opens == 0)
956 zvol_last_close(zv);
957
958 mutex_exit(&zfsdev_state_lock);
959 return (error);
960 }
961
962 static void
963 zvol_get_done(zgd_t *zgd, int error)
964 {
965 if (zgd->zgd_db)
966 dmu_buf_rele(zgd->zgd_db, zgd);
967
968 zfs_range_unlock(zgd->zgd_rl);
969
970 if (error == 0 && zgd->zgd_bp)
971 zil_add_block(zgd->zgd_zilog, zgd->zgd_bp);
972
973 kmem_free(zgd, sizeof (zgd_t));
974 }
975
976 /*
977 * Get data to generate a TX_WRITE intent log record.
978 */
979 static int
980 zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
981 {
982 zvol_state_t *zv = arg;
983 objset_t *os = zv->zv_objset;
984 uint64_t object = ZVOL_OBJ;
985 uint64_t offset = lr->lr_offset;
986 uint64_t size = lr->lr_length; /* length of user data */
987 blkptr_t *bp = &lr->lr_blkptr;
988 dmu_buf_t *db;
989 zgd_t *zgd;
990 int error;
991
992 ASSERT(zio != NULL);
993 ASSERT(size != 0);
994
995 zgd = kmem_zalloc(sizeof (zgd_t), KM_SLEEP);
996 zgd->zgd_zilog = zv->zv_zilog;
997 zgd->zgd_rl = zfs_range_lock(&zv->zv_znode, offset, size, RL_READER);
998
999 /*
1000 * Write records come in two flavors: immediate and indirect.
1001 * For small writes it's cheaper to store the data with the
1002 * log record (immediate); for large writes it's cheaper to
1003 * sync the data and get a pointer to it (indirect) so that
1004 * we don't have to write the data twice.
1005 */
1006 if (buf != NULL) { /* immediate write */
1007 error = dmu_read(os, object, offset, size, buf,
1008 DMU_READ_NO_PREFETCH);
1009 } else {
1010 size = zv->zv_volblocksize;
1011 offset = P2ALIGN(offset, size);
1012 error = dmu_buf_hold(os, object, offset, zgd, &db,
1013 DMU_READ_NO_PREFETCH);
1014 if (error == 0) {
1015 blkptr_t *obp = dmu_buf_get_blkptr(db);
1016 if (obp) {
1017 ASSERT(BP_IS_HOLE(bp));
1018 *bp = *obp;
1019 }
1020
1021 zgd->zgd_db = db;
1022 zgd->zgd_bp = bp;
1023
1024 ASSERT(db->db_offset == offset);
1025 ASSERT(db->db_size == size);
1026
1027 error = dmu_sync(zio, lr->lr_common.lrc_txg,
1028 zvol_get_done, zgd);
1029
1030 if (error == 0)
1031 return (0);
1032 }
1033 }
1034
1035 zvol_get_done(zgd, error);
1036
1037 return (error);
1038 }
1039
1040 /*
1041 * zvol_log_write() handles synchronous writes using TX_WRITE ZIL transactions.
1042 *
1043 * We store data in the log buffers if it's small enough.
1044 * Otherwise we will later flush the data out via dmu_sync().
1045 */
1046 ssize_t zvol_immediate_write_sz = 32768;
1047
1048 static void
1049 zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, offset_t off, ssize_t resid,
1050 boolean_t sync)
1051 {
1052 uint32_t blocksize = zv->zv_volblocksize;
1053 zilog_t *zilog = zv->zv_zilog;
1054 boolean_t slogging;
1055 ssize_t immediate_write_sz;
1056
1057 if (zil_replaying(zilog, tx))
1058 return;
1059
1060 immediate_write_sz = (zilog->zl_logbias == ZFS_LOGBIAS_THROUGHPUT)
1061 ? 0 : zvol_immediate_write_sz;
1062
1063 slogging = spa_has_slogs(zilog->zl_spa) &&
1064 (zilog->zl_logbias == ZFS_LOGBIAS_LATENCY);
1065
1066 while (resid) {
1067 itx_t *itx;
1068 lr_write_t *lr;
1069 ssize_t len;
1070 itx_wr_state_t write_state;
1071
1072 /*
1073 * Unlike zfs_log_write() we can be called with
1074 * upto DMU_MAX_ACCESS/2 (5MB) writes.
1075 */
1076 if (blocksize > immediate_write_sz && !slogging &&
1077 resid >= blocksize && off % blocksize == 0) {
1078 write_state = WR_INDIRECT; /* uses dmu_sync */
1079 len = blocksize;
1080 } else if (sync) {
1081 write_state = WR_COPIED;
1082 len = MIN(ZIL_MAX_LOG_DATA, resid);
1083 } else {
1084 write_state = WR_NEED_COPY;
1085 len = MIN(ZIL_MAX_LOG_DATA, resid);
1086 }
1087
1088 itx = zil_itx_create(TX_WRITE, sizeof (*lr) +
1089 (write_state == WR_COPIED ? len : 0));
1090 lr = (lr_write_t *)&itx->itx_lr;
1091 if (write_state == WR_COPIED && dmu_read(zv->zv_objset,
1092 ZVOL_OBJ, off, len, lr + 1, DMU_READ_NO_PREFETCH) != 0) {
1093 zil_itx_destroy(itx);
1094 itx = zil_itx_create(TX_WRITE, sizeof (*lr));
1095 lr = (lr_write_t *)&itx->itx_lr;
1096 write_state = WR_NEED_COPY;
1097 }
1098
1099 itx->itx_wr_state = write_state;
1100 if (write_state == WR_NEED_COPY)
1101 itx->itx_sod += len;
1102 lr->lr_foid = ZVOL_OBJ;
1103 lr->lr_offset = off;
1104 lr->lr_length = len;
1105 lr->lr_blkoff = 0;
1106 BP_ZERO(&lr->lr_blkptr);
1107
1108 itx->itx_private = zv;
1109 itx->itx_sync = sync;
1110
1111 zil_itx_assign(zilog, itx, tx);
1112
1113 off += len;
1114 resid -= len;
1115 }
1116 }
1117
1118 static int
1119 zvol_dumpio_vdev(vdev_t *vd, void *addr, uint64_t offset, uint64_t origoffset,
1120 uint64_t size, boolean_t doread, boolean_t isdump)
1121 {
1122 vdev_disk_t *dvd;
1123 int c;
1124 int numerrors = 0;
1125
1126 if (vd->vdev_ops == &vdev_mirror_ops ||
1127 vd->vdev_ops == &vdev_replacing_ops ||
1128 vd->vdev_ops == &vdev_spare_ops) {
1129 for (c = 0; c < vd->vdev_children; c++) {
1130 int err = zvol_dumpio_vdev(vd->vdev_child[c],
1131 addr, offset, origoffset, size, doread, isdump);
1132 if (err != 0) {
1133 numerrors++;
1134 } else if (doread) {
1135 break;
1136 }
1137 }
1138 }
1139
1140 if (!vd->vdev_ops->vdev_op_leaf && vd->vdev_ops != &vdev_raidz_ops)
1141 return (numerrors < vd->vdev_children ? 0 : EIO);
1142
1143 if (doread && !vdev_readable(vd))
1144 return (SET_ERROR(EIO));
1145 else if (!doread && !vdev_writeable(vd))
1146 return (SET_ERROR(EIO));
1147
1148 if (vd->vdev_ops == &vdev_raidz_ops) {
1149 return (vdev_raidz_physio(vd,
1150 addr, size, offset, origoffset, doread, isdump));
1151 }
1152
1153 offset += VDEV_LABEL_START_SIZE;
1154
1155 if (ddi_in_panic() || isdump) {
1156 ASSERT(!doread);
1157 if (doread)
1158 return (SET_ERROR(EIO));
1159 dvd = vd->vdev_tsd;
1160 ASSERT3P(dvd, !=, NULL);
1161 return (ldi_dump(dvd->vd_lh, addr, lbtodb(offset),
1162 lbtodb(size)));
1163 } else {
1164 dvd = vd->vdev_tsd;
1165 ASSERT3P(dvd, !=, NULL);
1166 return (vdev_disk_ldi_physio(dvd->vd_lh, addr, size,
1167 offset, doread ? B_READ : B_WRITE));
1168 }
1169 }
1170
1171 static int
1172 zvol_dumpio(zvol_state_t *zv, void *addr, uint64_t offset, uint64_t size,
1173 boolean_t doread, boolean_t isdump)
1174 {
1175 vdev_t *vd;
1176 int error;
1177 zvol_extent_t *ze;
1178 spa_t *spa = dmu_objset_spa(zv->zv_objset);
1179
1180 /* Must be sector aligned, and not stradle a block boundary. */
1181 if (P2PHASE(offset, DEV_BSIZE) || P2PHASE(size, DEV_BSIZE) ||
1182 P2BOUNDARY(offset, size, zv->zv_volblocksize)) {
1183 return (SET_ERROR(EINVAL));
1184 }
1185 ASSERT(size <= zv->zv_volblocksize);
1186
1187 /* Locate the extent this belongs to */
1188 ze = list_head(&zv->zv_extents);
1189 while (offset >= ze->ze_nblks * zv->zv_volblocksize) {
1190 offset -= ze->ze_nblks * zv->zv_volblocksize;
1191 ze = list_next(&zv->zv_extents, ze);
1192 }
1193
1194 if (ze == NULL)
1195 return (SET_ERROR(EINVAL));
1196
1197 if (!ddi_in_panic())
1198 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
1199
1200 vd = vdev_lookup_top(spa, DVA_GET_VDEV(&ze->ze_dva));
1201 offset += DVA_GET_OFFSET(&ze->ze_dva);
1202 error = zvol_dumpio_vdev(vd, addr, offset, DVA_GET_OFFSET(&ze->ze_dva),
1203 size, doread, isdump);
1204
1205 if (!ddi_in_panic())
1206 spa_config_exit(spa, SCL_STATE, FTAG);
1207
1208 return (error);
1209 }
1210
1211 int
1212 zvol_strategy(buf_t *bp)
1213 {
1214 zfs_soft_state_t *zs = NULL;
1215 zvol_state_t *zv;
1216 uint64_t off, volsize;
1217 size_t resid;
1218 char *addr;
1219 objset_t *os;
1220 rl_t *rl;
1221 int error = 0;
1222 boolean_t doread = bp->b_flags & B_READ;
1223 boolean_t is_dumpified;
1224 boolean_t sync;
1225
1226 if (getminor(bp->b_edev) == 0) {
1227 error = SET_ERROR(EINVAL);
1228 } else {
1229 zs = ddi_get_soft_state(zfsdev_state, getminor(bp->b_edev));
1230 if (zs == NULL)
1231 error = SET_ERROR(ENXIO);
1232 else if (zs->zss_type != ZSST_ZVOL)
1233 error = SET_ERROR(EINVAL);
1234 }
1235
1236 if (error) {
1237 bioerror(bp, error);
1238 biodone(bp);
1239 return (0);
1240 }
1241
1242 zv = zs->zss_data;
1243
1244 if (!(bp->b_flags & B_READ) && (zv->zv_flags & ZVOL_RDONLY)) {
1245 bioerror(bp, EROFS);
1246 biodone(bp);
1247 return (0);
1248 }
1249
1250 off = ldbtob(bp->b_blkno);
1251 volsize = zv->zv_volsize;
1252
1253 os = zv->zv_objset;
1254 ASSERT(os != NULL);
1255
1256 bp_mapin(bp);
1257 addr = bp->b_un.b_addr;
1258 resid = bp->b_bcount;
1259
1260 if (resid > 0 && (off < 0 || off >= volsize)) {
1261 bioerror(bp, EIO);
1262 biodone(bp);
1263 return (0);
1264 }
1265
1266 is_dumpified = zv->zv_flags & ZVOL_DUMPIFIED;
1267 sync = ((!(bp->b_flags & B_ASYNC) &&
1268 !(zv->zv_flags & ZVOL_WCE)) ||
1269 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS)) &&
1270 !doread && !is_dumpified;
1271
1272 /*
1273 * There must be no buffer changes when doing a dmu_sync() because
1274 * we can't change the data whilst calculating the checksum.
1275 */
1276 rl = zfs_range_lock(&zv->zv_znode, off, resid,
1277 doread ? RL_READER : RL_WRITER);
1278
1279 while (resid != 0 && off < volsize) {
1280 size_t size = MIN(resid, zvol_maxphys);
1281 if (is_dumpified) {
1282 size = MIN(size, P2END(off, zv->zv_volblocksize) - off);
1283 error = zvol_dumpio(zv, addr, off, size,
1284 doread, B_FALSE);
1285 } else if (doread) {
1286 error = dmu_read(os, ZVOL_OBJ, off, size, addr,
1287 DMU_READ_PREFETCH);
1288 } else {
1289 dmu_tx_t *tx = dmu_tx_create(os);
1290 dmu_tx_hold_write(tx, ZVOL_OBJ, off, size);
1291 error = dmu_tx_assign(tx, TXG_WAIT);
1292 if (error) {
1293 dmu_tx_abort(tx);
1294 } else {
1295 dmu_write(os, ZVOL_OBJ, off, size, addr, tx);
1296 zvol_log_write(zv, tx, off, size, sync);
1297 dmu_tx_commit(tx);
1298 }
1299 }
1300 if (error) {
1301 /* convert checksum errors into IO errors */
1302 if (error == ECKSUM)
1303 error = SET_ERROR(EIO);
1304 break;
1305 }
1306 off += size;
1307 addr += size;
1308 resid -= size;
1309 }
1310 zfs_range_unlock(rl);
1311
1312 if ((bp->b_resid = resid) == bp->b_bcount)
1313 bioerror(bp, off > volsize ? EINVAL : error);
1314
1315 if (sync)
1316 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1317 biodone(bp);
1318
1319 return (0);
1320 }
1321
1322 /*
1323 * Set the buffer count to the zvol maximum transfer.
1324 * Using our own routine instead of the default minphys()
1325 * means that for larger writes we write bigger buffers on X86
1326 * (128K instead of 56K) and flush the disk write cache less often
1327 * (every zvol_maxphys - currently 1MB) instead of minphys (currently
1328 * 56K on X86 and 128K on sparc).
1329 */
1330 void
1331 zvol_minphys(struct buf *bp)
1332 {
1333 if (bp->b_bcount > zvol_maxphys)
1334 bp->b_bcount = zvol_maxphys;
1335 }
1336
1337 int
1338 zvol_dump(dev_t dev, caddr_t addr, daddr_t blkno, int nblocks)
1339 {
1340 minor_t minor = getminor(dev);
1341 zvol_state_t *zv;
1342 int error = 0;
1343 uint64_t size;
1344 uint64_t boff;
1345 uint64_t resid;
1346
1347 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1348 if (zv == NULL)
1349 return (SET_ERROR(ENXIO));
1350
1351 if ((zv->zv_flags & ZVOL_DUMPIFIED) == 0)
1352 return (SET_ERROR(EINVAL));
1353
1354 boff = ldbtob(blkno);
1355 resid = ldbtob(nblocks);
1356
1357 VERIFY3U(boff + resid, <=, zv->zv_volsize);
1358
1359 while (resid) {
1360 size = MIN(resid, P2END(boff, zv->zv_volblocksize) - boff);
1361 error = zvol_dumpio(zv, addr, boff, size, B_FALSE, B_TRUE);
1362 if (error)
1363 break;
1364 boff += size;
1365 addr += size;
1366 resid -= size;
1367 }
1368
1369 return (error);
1370 }
1371
1372 /*ARGSUSED*/
1373 int
1374 zvol_read(dev_t dev, uio_t *uio, cred_t *cr)
1375 {
1376 minor_t minor = getminor(dev);
1377 zvol_state_t *zv;
1378 uint64_t volsize;
1379 rl_t *rl;
1380 int error = 0;
1381
1382 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1383 if (zv == NULL)
1384 return (SET_ERROR(ENXIO));
1385
1386 volsize = zv->zv_volsize;
1387 if (uio->uio_resid > 0 &&
1388 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize))
1389 return (SET_ERROR(EIO));
1390
1391 if (zv->zv_flags & ZVOL_DUMPIFIED) {
1392 error = physio(zvol_strategy, NULL, dev, B_READ,
1393 zvol_minphys, uio);
1394 return (error);
1395 }
1396
1397 rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid,
1398 RL_READER);
1399 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) {
1400 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1);
1401
1402 /* don't read past the end */
1403 if (bytes > volsize - uio->uio_loffset)
1404 bytes = volsize - uio->uio_loffset;
1405
1406 error = dmu_read_uio(zv->zv_objset, ZVOL_OBJ, uio, bytes);
1407 if (error) {
1408 /* convert checksum errors into IO errors */
1409 if (error == ECKSUM)
1410 error = SET_ERROR(EIO);
1411 break;
1412 }
1413 }
1414 zfs_range_unlock(rl);
1415 return (error);
1416 }
1417
1418 /*ARGSUSED*/
1419 int
1420 zvol_write(dev_t dev, uio_t *uio, cred_t *cr)
1421 {
1422 minor_t minor = getminor(dev);
1423 zvol_state_t *zv;
1424 uint64_t volsize;
1425 rl_t *rl;
1426 int error = 0;
1427 boolean_t sync;
1428
1429 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1430 if (zv == NULL)
1431 return (SET_ERROR(ENXIO));
1432
1433 volsize = zv->zv_volsize;
1434 if (uio->uio_resid > 0 &&
1435 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize))
1436 return (SET_ERROR(EIO));
1437
1438 if (zv->zv_flags & ZVOL_DUMPIFIED) {
1439 error = physio(zvol_strategy, NULL, dev, B_WRITE,
1440 zvol_minphys, uio);
1441 return (error);
1442 }
1443
1444 sync = !(zv->zv_flags & ZVOL_WCE) ||
1445 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS);
1446
1447 rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid,
1448 RL_WRITER);
1449 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) {
1450 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1);
1451 uint64_t off = uio->uio_loffset;
1452 dmu_tx_t *tx = dmu_tx_create(zv->zv_objset);
1453
1454 if (bytes > volsize - off) /* don't write past the end */
1455 bytes = volsize - off;
1456
1457 dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes);
1458 error = dmu_tx_assign(tx, TXG_WAIT);
1459 if (error) {
1460 dmu_tx_abort(tx);
1461 break;
1462 }
1463 error = dmu_write_uio_dbuf(zv->zv_dbuf, uio, bytes, tx);
1464 if (error == 0)
1465 zvol_log_write(zv, tx, off, bytes, sync);
1466 dmu_tx_commit(tx);
1467
1468 if (error)
1469 break;
1470 }
1471 zfs_range_unlock(rl);
1472 if (sync)
1473 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1474 return (error);
1475 }
1476
1477 int
1478 zvol_getefi(void *arg, int flag, uint64_t vs, uint8_t bs)
1479 {
1480 struct uuid uuid = EFI_RESERVED;
1481 efi_gpe_t gpe = { 0 };
1482 uint32_t crc;
1483 dk_efi_t efi;
1484 int length;
1485 char *ptr;
1486
1487 if (ddi_copyin(arg, &efi, sizeof (dk_efi_t), flag))
1488 return (SET_ERROR(EFAULT));
1489 ptr = (char *)(uintptr_t)efi.dki_data_64;
1490 length = efi.dki_length;
1491 /*
1492 * Some clients may attempt to request a PMBR for the
1493 * zvol. Currently this interface will return EINVAL to
1494 * such requests. These requests could be supported by
1495 * adding a check for lba == 0 and consing up an appropriate
1496 * PMBR.
1497 */
1498 if (efi.dki_lba < 1 || efi.dki_lba > 2 || length <= 0)
1499 return (SET_ERROR(EINVAL));
1500
1501 gpe.efi_gpe_StartingLBA = LE_64(34ULL);
1502 gpe.efi_gpe_EndingLBA = LE_64((vs >> bs) - 1);
1503 UUID_LE_CONVERT(gpe.efi_gpe_PartitionTypeGUID, uuid);
1504
1505 if (efi.dki_lba == 1) {
1506 efi_gpt_t gpt = { 0 };
1507
1508 gpt.efi_gpt_Signature = LE_64(EFI_SIGNATURE);
1509 gpt.efi_gpt_Revision = LE_32(EFI_VERSION_CURRENT);
1510 gpt.efi_gpt_HeaderSize = LE_32(sizeof (gpt));
1511 gpt.efi_gpt_MyLBA = LE_64(1ULL);
1512 gpt.efi_gpt_FirstUsableLBA = LE_64(34ULL);
1513 gpt.efi_gpt_LastUsableLBA = LE_64((vs >> bs) - 1);
1514 gpt.efi_gpt_PartitionEntryLBA = LE_64(2ULL);
1515 gpt.efi_gpt_NumberOfPartitionEntries = LE_32(1);
1516 gpt.efi_gpt_SizeOfPartitionEntry =
1517 LE_32(sizeof (efi_gpe_t));
1518 CRC32(crc, &gpe, sizeof (gpe), -1U, crc32_table);
1519 gpt.efi_gpt_PartitionEntryArrayCRC32 = LE_32(~crc);
1520 CRC32(crc, &gpt, sizeof (gpt), -1U, crc32_table);
1521 gpt.efi_gpt_HeaderCRC32 = LE_32(~crc);
1522 if (ddi_copyout(&gpt, ptr, MIN(sizeof (gpt), length),
1523 flag))
1524 return (SET_ERROR(EFAULT));
1525 ptr += sizeof (gpt);
1526 length -= sizeof (gpt);
1527 }
1528 if (length > 0 && ddi_copyout(&gpe, ptr, MIN(sizeof (gpe),
1529 length), flag))
1530 return (SET_ERROR(EFAULT));
1531 return (0);
1532 }
1533
1534 /*
1535 * BEGIN entry points to allow external callers access to the volume.
1536 */
1537 /*
1538 * Return the volume parameters needed for access from an external caller.
1539 * These values are invariant as long as the volume is held open.
1540 */
1541 int
1542 zvol_get_volume_params(minor_t minor, uint64_t *blksize,
1543 uint64_t *max_xfer_len, void **minor_hdl, void **objset_hdl, void **zil_hdl,
1544 void **rl_hdl, void **bonus_hdl)
1545 {
1546 zvol_state_t *zv;
1547
1548 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1549 if (zv == NULL)
1550 return (SET_ERROR(ENXIO));
1551 if (zv->zv_flags & ZVOL_DUMPIFIED)
1552 return (SET_ERROR(ENXIO));
1553
1554 ASSERT(blksize && max_xfer_len && minor_hdl &&
1555 objset_hdl && zil_hdl && rl_hdl && bonus_hdl);
1556
1557 *blksize = zv->zv_volblocksize;
1558 *max_xfer_len = (uint64_t)zvol_maxphys;
1559 *minor_hdl = zv;
1560 *objset_hdl = zv->zv_objset;
1561 *zil_hdl = zv->zv_zilog;
1562 *rl_hdl = &zv->zv_znode;
1563 *bonus_hdl = zv->zv_dbuf;
1564 return (0);
1565 }
1566
1567 /*
1568 * Return the current volume size to an external caller.
1569 * The size can change while the volume is open.
1570 */
1571 uint64_t
1572 zvol_get_volume_size(void *minor_hdl)
1573 {
1574 zvol_state_t *zv = minor_hdl;
1575
1576 return (zv->zv_volsize);
1577 }
1578
1579 /*
1580 * Return the current WCE setting to an external caller.
1581 * The WCE setting can change while the volume is open.
1582 */
1583 int
1584 zvol_get_volume_wce(void *minor_hdl)
1585 {
1586 zvol_state_t *zv = minor_hdl;
1587
1588 return ((zv->zv_flags & ZVOL_WCE) ? 1 : 0);
1589 }
1590
1591 /*
1592 * Entry point for external callers to zvol_log_write
1593 */
1594 void
1595 zvol_log_write_minor(void *minor_hdl, dmu_tx_t *tx, offset_t off, ssize_t resid,
1596 boolean_t sync)
1597 {
1598 zvol_state_t *zv = minor_hdl;
1599
1600 zvol_log_write(zv, tx, off, resid, sync);
1601 }
1602 /*
1603 * END entry points to allow external callers access to the volume.
1604 */
1605
1606 /*
1607 * Log a DKIOCFREE/free-long-range to the ZIL with TX_TRUNCATE.
1608 */
1609 static void
1610 zvol_log_truncate(zvol_state_t *zv, dmu_tx_t *tx, uint64_t off, uint64_t len,
1611 boolean_t sync)
1612 {
1613 itx_t *itx;
1614 lr_truncate_t *lr;
1615 zilog_t *zilog = zv->zv_zilog;
1616
1617 if (zil_replaying(zilog, tx))
1618 return;
1619
1620 itx = zil_itx_create(TX_TRUNCATE, sizeof (*lr));
1621 lr = (lr_truncate_t *)&itx->itx_lr;
1622 lr->lr_foid = ZVOL_OBJ;
1623 lr->lr_offset = off;
1624 lr->lr_length = len;
1625
1626 itx->itx_sync = sync;
1627 zil_itx_assign(zilog, itx, tx);
1628 }
1629
1630 /*
1631 * Dirtbag ioctls to support mkfs(1M) for UFS filesystems. See dkio(7I).
1632 * Also a dirtbag dkio ioctl for unmap/free-block functionality.
1633 */
1634 /*ARGSUSED*/
1635 int
1636 zvol_ioctl(dev_t dev, int cmd, intptr_t arg, int flag, cred_t *cr, int *rvalp)
1637 {
1638 zvol_state_t *zv;
1639 struct dk_callback *dkc;
1640 int error = 0;
1641 rl_t *rl;
1642
1643 mutex_enter(&zfsdev_state_lock);
1644
1645 zv = zfsdev_get_soft_state(getminor(dev), ZSST_ZVOL);
1646
1647 if (zv == NULL) {
1648 mutex_exit(&zfsdev_state_lock);
1649 return (SET_ERROR(ENXIO));
1650 }
1651 ASSERT(zv->zv_total_opens > 0);
1652
1653 switch (cmd) {
1654
1655 case DKIOCINFO:
1656 {
1657 struct dk_cinfo dki;
1658
1659 bzero(&dki, sizeof (dki));
1660 (void) strcpy(dki.dki_cname, "zvol");
1661 (void) strcpy(dki.dki_dname, "zvol");
1662 dki.dki_ctype = DKC_UNKNOWN;
1663 dki.dki_unit = getminor(dev);
1664 dki.dki_maxtransfer =
1665 1 << (SPA_OLD_MAXBLOCKSHIFT - zv->zv_min_bs);
1666 mutex_exit(&zfsdev_state_lock);
1667 if (ddi_copyout(&dki, (void *)arg, sizeof (dki), flag))
1668 error = SET_ERROR(EFAULT);
1669 return (error);
1670 }
1671
1672 case DKIOCGMEDIAINFO:
1673 {
1674 struct dk_minfo dkm;
1675
1676 bzero(&dkm, sizeof (dkm));
1677 dkm.dki_lbsize = 1U << zv->zv_min_bs;
1678 dkm.dki_capacity = zv->zv_volsize >> zv->zv_min_bs;
1679 dkm.dki_media_type = DK_UNKNOWN;
1680 mutex_exit(&zfsdev_state_lock);
1681 if (ddi_copyout(&dkm, (void *)arg, sizeof (dkm), flag))
1682 error = SET_ERROR(EFAULT);
1683 return (error);
1684 }
1685
1686 case DKIOCGMEDIAINFOEXT:
1687 {
1688 struct dk_minfo_ext dkmext;
1689
1690 bzero(&dkmext, sizeof (dkmext));
1691 dkmext.dki_lbsize = 1U << zv->zv_min_bs;
1692 dkmext.dki_pbsize = zv->zv_volblocksize;
1693 dkmext.dki_capacity = zv->zv_volsize >> zv->zv_min_bs;
1694 dkmext.dki_media_type = DK_UNKNOWN;
1695 mutex_exit(&zfsdev_state_lock);
1696 if (ddi_copyout(&dkmext, (void *)arg, sizeof (dkmext), flag))
1697 error = SET_ERROR(EFAULT);
1698 return (error);
1699 }
1700
1701 case DKIOCGETEFI:
1702 {
1703 uint64_t vs = zv->zv_volsize;
1704 uint8_t bs = zv->zv_min_bs;
1705
1706 mutex_exit(&zfsdev_state_lock);
1707 error = zvol_getefi((void *)arg, flag, vs, bs);
1708 return (error);
1709 }
1710
1711 case DKIOCFLUSHWRITECACHE:
1712 dkc = (struct dk_callback *)arg;
1713 mutex_exit(&zfsdev_state_lock);
1714 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1715 if ((flag & FKIOCTL) && dkc != NULL && dkc->dkc_callback) {
1716 (*dkc->dkc_callback)(dkc->dkc_cookie, error);
1717 error = 0;
1718 }
1719 return (error);
1720
1721 case DKIOCGETWCE:
1722 {
1723 int wce = (zv->zv_flags & ZVOL_WCE) ? 1 : 0;
1724 if (ddi_copyout(&wce, (void *)arg, sizeof (int),
1725 flag))
1726 error = SET_ERROR(EFAULT);
1727 break;
1728 }
1729 case DKIOCSETWCE:
1730 {
1731 int wce;
1732 if (ddi_copyin((void *)arg, &wce, sizeof (int),
1733 flag)) {
1734 error = SET_ERROR(EFAULT);
1735 break;
1736 }
1737 if (wce) {
1738 zv->zv_flags |= ZVOL_WCE;
1739 mutex_exit(&zfsdev_state_lock);
1740 } else {
1741 zv->zv_flags &= ~ZVOL_WCE;
1742 mutex_exit(&zfsdev_state_lock);
1743 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1744 }
1745 return (0);
1746 }
1747
1748 case DKIOCGGEOM:
1749 case DKIOCGVTOC:
1750 /*
1751 * commands using these (like prtvtoc) expect ENOTSUP
1752 * since we're emulating an EFI label
1753 */
1754 error = SET_ERROR(ENOTSUP);
1755 break;
1756
1757 case DKIOCDUMPINIT:
1758 rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize,
1759 RL_WRITER);
1760 error = zvol_dumpify(zv);
1761 zfs_range_unlock(rl);
1762 break;
1763
1764 case DKIOCDUMPFINI:
1765 if (!(zv->zv_flags & ZVOL_DUMPIFIED))
1766 break;
1767 rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize,
1768 RL_WRITER);
1769 error = zvol_dump_fini(zv);
1770 zfs_range_unlock(rl);
1771 break;
1772
1773 case DKIOCFREE:
1774 {
1775 dkioc_free_t df;
1776 dmu_tx_t *tx;
1777
1778 if (!zvol_unmap_enabled)
1779 break;
1780
1781 if (ddi_copyin((void *)arg, &df, sizeof (df), flag)) {
1782 error = SET_ERROR(EFAULT);
1783 break;
1784 }
1785
1786 /*
1787 * Apply Postel's Law to length-checking. If they overshoot,
1788 * just blank out until the end, if there's a need to blank
1789 * out anything.
1790 */
1791 if (df.df_start >= zv->zv_volsize)
1792 break; /* No need to do anything... */
1793
1794 mutex_exit(&zfsdev_state_lock);
1795
1796 rl = zfs_range_lock(&zv->zv_znode, df.df_start, df.df_length,
1797 RL_WRITER);
1798 tx = dmu_tx_create(zv->zv_objset);
1799 dmu_tx_mark_netfree(tx);
1800 error = dmu_tx_assign(tx, TXG_WAIT);
1801 if (error != 0) {
1802 dmu_tx_abort(tx);
1803 } else {
1804 zvol_log_truncate(zv, tx, df.df_start,
1805 df.df_length, B_TRUE);
1806 dmu_tx_commit(tx);
1807 error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ,
1808 df.df_start, df.df_length);
1809 }
1810
1811 zfs_range_unlock(rl);
1812
1813 if (error == 0) {
1814 /*
1815 * If the write-cache is disabled or 'sync' property
1816 * is set to 'always' then treat this as a synchronous
1817 * operation (i.e. commit to zil).
1818 */
1819 if (!(zv->zv_flags & ZVOL_WCE) ||
1820 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS))
1821 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1822
1823 /*
1824 * If the caller really wants synchronous writes, and
1825 * can't wait for them, don't return until the write
1826 * is done.
1827 */
1828 if (df.df_flags & DF_WAIT_SYNC) {
1829 txg_wait_synced(
1830 dmu_objset_pool(zv->zv_objset), 0);
1831 }
1832 }
1833 return (error);
1834 }
1835
1836 default:
1837 error = SET_ERROR(ENOTTY);
1838 break;
1839
1840 }
1841 mutex_exit(&zfsdev_state_lock);
1842 return (error);
1843 }
1844
1845 int
1846 zvol_busy(void)
1847 {
1848 return (zvol_minors != 0);
1849 }
1850
1851 void
1852 zvol_init(void)
1853 {
1854 VERIFY(ddi_soft_state_init(&zfsdev_state, sizeof (zfs_soft_state_t),
1855 1) == 0);
1856 mutex_init(&zfsdev_state_lock, NULL, MUTEX_DEFAULT, NULL);
1857 }
1858
1859 void
1860 zvol_fini(void)
1861 {
1862 mutex_destroy(&zfsdev_state_lock);
1863 ddi_soft_state_fini(&zfsdev_state);
1864 }
1865
1866 /*ARGSUSED*/
1867 static int
1868 zfs_mvdev_dump_feature_check(void *arg, dmu_tx_t *tx)
1869 {
1870 spa_t *spa = dmu_tx_pool(tx)->dp_spa;
1871
1872 if (spa_feature_is_active(spa, SPA_FEATURE_MULTI_VDEV_CRASH_DUMP))
1873 return (1);
1874 return (0);
1875 }
1876
1877 /*ARGSUSED*/
1878 static void
1879 zfs_mvdev_dump_activate_feature_sync(void *arg, dmu_tx_t *tx)
1880 {
1881 spa_t *spa = dmu_tx_pool(tx)->dp_spa;
1882
1883 spa_feature_incr(spa, SPA_FEATURE_MULTI_VDEV_CRASH_DUMP, tx);
1884 }
1885
1886 static int
1887 zvol_dump_init(zvol_state_t *zv, boolean_t resize)
1888 {
1889 dmu_tx_t *tx;
1890 int error;
1891 objset_t *os = zv->zv_objset;
1892 spa_t *spa = dmu_objset_spa(os);
1893 vdev_t *vd = spa->spa_root_vdev;
1894 nvlist_t *nv = NULL;
1895 uint64_t version = spa_version(spa);
1896 enum zio_checksum checksum;
1897
1898 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
1899 ASSERT(vd->vdev_ops == &vdev_root_ops);
1900
1901 error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, 0,
1902 DMU_OBJECT_END);
1903 /* wait for dmu_free_long_range to actually free the blocks */
1904 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
1905
1906 /*
1907 * If the pool on which the dump device is being initialized has more
1908 * than one child vdev, check that the MULTI_VDEV_CRASH_DUMP feature is
1909 * enabled. If so, bump that feature's counter to indicate that the
1910 * feature is active. We also check the vdev type to handle the
1911 * following case:
1912 * # zpool create test raidz disk1 disk2 disk3
1913 * Now have spa_root_vdev->vdev_children == 1 (the raidz vdev),
1914 * the raidz vdev itself has 3 children.
1915 */
1916 if (vd->vdev_children > 1 || vd->vdev_ops == &vdev_raidz_ops) {
1917 if (!spa_feature_is_enabled(spa,
1918 SPA_FEATURE_MULTI_VDEV_CRASH_DUMP))
1919 return (SET_ERROR(ENOTSUP));
1920 (void) dsl_sync_task(spa_name(spa),
1921 zfs_mvdev_dump_feature_check,
1922 zfs_mvdev_dump_activate_feature_sync, NULL,
1923 2, ZFS_SPACE_CHECK_RESERVED);
1924 }
1925
1926 tx = dmu_tx_create(os);
1927 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
1928 dmu_tx_hold_bonus(tx, ZVOL_OBJ);
1929 error = dmu_tx_assign(tx, TXG_WAIT);
1930 if (error) {
1931 dmu_tx_abort(tx);
1932 return (error);
1933 }
1934
1935 /*
1936 * If MULTI_VDEV_CRASH_DUMP is active, use the NOPARITY checksum
1937 * function. Otherwise, use the old default -- OFF.
1938 */
1939 checksum = spa_feature_is_active(spa,
1940 SPA_FEATURE_MULTI_VDEV_CRASH_DUMP) ? ZIO_CHECKSUM_NOPARITY :
1941 ZIO_CHECKSUM_OFF;
1942
1943 /*
1944 * If we are resizing the dump device then we only need to
1945 * update the refreservation to match the newly updated
1946 * zvolsize. Otherwise, we save off the original state of the
1947 * zvol so that we can restore them if the zvol is ever undumpified.
1948 */
1949 if (resize) {
1950 error = zap_update(os, ZVOL_ZAP_OBJ,
1951 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1,
1952 &zv->zv_volsize, tx);
1953 } else {
1954 uint64_t checksum, compress, refresrv, vbs, dedup;
1955
1956 error = dsl_prop_get_integer(zv->zv_name,
1957 zfs_prop_to_name(ZFS_PROP_COMPRESSION), &compress, NULL);
1958 error = error ? error : dsl_prop_get_integer(zv->zv_name,
1959 zfs_prop_to_name(ZFS_PROP_CHECKSUM), &checksum, NULL);
1960 error = error ? error : dsl_prop_get_integer(zv->zv_name,
1961 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), &refresrv, NULL);
1962 error = error ? error : dsl_prop_get_integer(zv->zv_name,
1963 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &vbs, NULL);
1964 if (version >= SPA_VERSION_DEDUP) {
1965 error = error ? error :
1966 dsl_prop_get_integer(zv->zv_name,
1967 zfs_prop_to_name(ZFS_PROP_DEDUP), &dedup, NULL);
1968 }
1969
1970 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ,
1971 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1,
1972 &compress, tx);
1973 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ,
1974 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1, &checksum, tx);
1975 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ,
1976 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1,
1977 &refresrv, tx);
1978 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ,
1979 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1,
1980 &vbs, tx);
1981 error = error ? error : dmu_object_set_blocksize(
1982 os, ZVOL_OBJ, SPA_OLD_MAXBLOCKSIZE, 0, tx);
1983 if (version >= SPA_VERSION_DEDUP) {
1984 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ,
1985 zfs_prop_to_name(ZFS_PROP_DEDUP), 8, 1,
1986 &dedup, tx);
1987 }
1988 if (error == 0)
1989 zv->zv_volblocksize = SPA_OLD_MAXBLOCKSIZE;
1990 }
1991 dmu_tx_commit(tx);
1992
1993 /*
1994 * We only need update the zvol's property if we are initializing
1995 * the dump area for the first time.
1996 */
1997 if (!resize) {
1998 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
1999 VERIFY(nvlist_add_uint64(nv,
2000 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 0) == 0);
2001 VERIFY(nvlist_add_uint64(nv,
2002 zfs_prop_to_name(ZFS_PROP_COMPRESSION),
2003 ZIO_COMPRESS_OFF) == 0);
2004 VERIFY(nvlist_add_uint64(nv,
2005 zfs_prop_to_name(ZFS_PROP_CHECKSUM),
2006 checksum) == 0);
2007 if (version >= SPA_VERSION_DEDUP) {
2008 VERIFY(nvlist_add_uint64(nv,
2009 zfs_prop_to_name(ZFS_PROP_DEDUP),
2010 ZIO_CHECKSUM_OFF) == 0);
2011 }
2012
2013 error = zfs_set_prop_nvlist(zv->zv_name, ZPROP_SRC_LOCAL,
2014 nv, NULL);
2015 nvlist_free(nv);
2016
2017 if (error)
2018 return (error);
2019 }
2020
2021 /* Allocate the space for the dump */
2022 error = zvol_prealloc(zv);
2023 return (error);
2024 }
2025
2026 static int
2027 zvol_dumpify(zvol_state_t *zv)
2028 {
2029 int error = 0;
2030 uint64_t dumpsize = 0;
2031 dmu_tx_t *tx;
2032 objset_t *os = zv->zv_objset;
2033
2034 if (zv->zv_flags & ZVOL_RDONLY)
2035 return (SET_ERROR(EROFS));
2036
2037 if (zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE,
2038 8, 1, &dumpsize) != 0 || dumpsize != zv->zv_volsize) {
2039 boolean_t resize = (dumpsize > 0);
2040
2041 if ((error = zvol_dump_init(zv, resize)) != 0) {
2042 (void) zvol_dump_fini(zv);
2043 return (error);
2044 }
2045 }
2046
2047 /*
2048 * Build up our lba mapping.
2049 */
2050 error = zvol_get_lbas(zv);
2051 if (error) {
2052 (void) zvol_dump_fini(zv);
2053 return (error);
2054 }
2055
2056 tx = dmu_tx_create(os);
2057 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
2058 error = dmu_tx_assign(tx, TXG_WAIT);
2059 if (error) {
2060 dmu_tx_abort(tx);
2061 (void) zvol_dump_fini(zv);
2062 return (error);
2063 }
2064
2065 zv->zv_flags |= ZVOL_DUMPIFIED;
2066 error = zap_update(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, 8, 1,
2067 &zv->zv_volsize, tx);
2068 dmu_tx_commit(tx);
2069
2070 if (error) {
2071 (void) zvol_dump_fini(zv);
2072 return (error);
2073 }
2074
2075 txg_wait_synced(dmu_objset_pool(os), 0);
2076 return (0);
2077 }
2078
2079 static int
2080 zvol_dump_fini(zvol_state_t *zv)
2081 {
2082 dmu_tx_t *tx;
2083 objset_t *os = zv->zv_objset;
2084 nvlist_t *nv;
2085 int error = 0;
2086 uint64_t checksum, compress, refresrv, vbs, dedup;
2087 uint64_t version = spa_version(dmu_objset_spa(zv->zv_objset));
2088
2089 /*
2090 * Attempt to restore the zvol back to its pre-dumpified state.
2091 * This is a best-effort attempt as it's possible that not all
2092 * of these properties were initialized during the dumpify process
2093 * (i.e. error during zvol_dump_init).
2094 */
2095
2096 tx = dmu_tx_create(os);
2097 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
2098 error = dmu_tx_assign(tx, TXG_WAIT);
2099 if (error) {
2100 dmu_tx_abort(tx);
2101 return (error);
2102 }
2103 (void) zap_remove(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, tx);
2104 dmu_tx_commit(tx);
2105
2106 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2107 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1, &checksum);
2108 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2109 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1, &compress);
2110 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2111 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, &refresrv);
2112 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2113 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1, &vbs);
2114
2115 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2116 (void) nvlist_add_uint64(nv,
2117 zfs_prop_to_name(ZFS_PROP_CHECKSUM), checksum);
2118 (void) nvlist_add_uint64(nv,
2119 zfs_prop_to_name(ZFS_PROP_COMPRESSION), compress);
2120 (void) nvlist_add_uint64(nv,
2121 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), refresrv);
2122 if (version >= SPA_VERSION_DEDUP &&
2123 zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2124 zfs_prop_to_name(ZFS_PROP_DEDUP), 8, 1, &dedup) == 0) {
2125 (void) nvlist_add_uint64(nv,
2126 zfs_prop_to_name(ZFS_PROP_DEDUP), dedup);
2127 }
2128 (void) zfs_set_prop_nvlist(zv->zv_name, ZPROP_SRC_LOCAL,
2129 nv, NULL);
2130 nvlist_free(nv);
2131
2132 zvol_free_extents(zv);
2133 zv->zv_flags &= ~ZVOL_DUMPIFIED;
2134 (void) dmu_free_long_range(os, ZVOL_OBJ, 0, DMU_OBJECT_END);
2135 /* wait for dmu_free_long_range to actually free the blocks */
2136 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
2137 tx = dmu_tx_create(os);
2138 dmu_tx_hold_bonus(tx, ZVOL_OBJ);
2139 error = dmu_tx_assign(tx, TXG_WAIT);
2140 if (error) {
2141 dmu_tx_abort(tx);
2142 return (error);
2143 }
2144 if (dmu_object_set_blocksize(os, ZVOL_OBJ, vbs, 0, tx) == 0)
2145 zv->zv_volblocksize = vbs;
2146 dmu_tx_commit(tx);
2147
2148 return (0);
2149 }
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