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libc: add strtonum(3)
[unleashed/tickless.git] / kernel / fs / zfs / zvol.c
blobb857b9b560b0edfd67a9033caf082a3787adb4d0
1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 *
24 * Portions Copyright 2010 Robert Milkowski
25 *
26 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
27 * Copyright (c) 2012, 2017 by Delphix. All rights reserved.
28 * Copyright (c) 2013, Joyent, Inc. All rights reserved.
29 * Copyright (c) 2014 Integros [integros.com]
30 */
31
32 /*
33 * ZFS volume emulation driver.
34 *
35 * Makes a DMU object look like a volume of arbitrary size, up to 2^64 bytes.
36 * Volumes are accessed through the symbolic links named:
37 *
38 * /dev/zvol/dsk/<pool_name>/<dataset_name>
39 * /dev/zvol/rdsk/<pool_name>/<dataset_name>
40 *
41 * These links are created by the /dev filesystem (sdev_zvolops.c).
42 * Volumes are persistent through reboot. No user command needs to be
43 * run before opening and using a device.
44 */
45
46 #include <sys/types.h>
47 #include <sys/param.h>
48 #include <sys/errno.h>
49 #include <sys/uio.h>
50 #include <sys/buf.h>
51 #include <sys/modctl.h>
52 #include <sys/open.h>
53 #include <sys/kmem.h>
54 #include <sys/conf.h>
55 #include <sys/cmn_err.h>
56 #include <sys/stat.h>
57 #include <sys/zap.h>
58 #include <sys/spa.h>
59 #include <sys/spa_impl.h>
60 #include <sys/zio.h>
61 #include <sys/dmu_traverse.h>
62 #include <sys/dnode.h>
63 #include <sys/dsl_dataset.h>
64 #include <sys/dsl_prop.h>
65 #include <sys/dkio.h>
66 #include <sys/efi_partition.h>
67 #include <sys/byteorder.h>
68 #include <sys/pathname.h>
69 #include <sys/ddi.h>
70 #include <sys/sunddi.h>
71 #include <sys/crc32.h>
72 #include <sys/dirent.h>
73 #include <sys/policy.h>
74 #include <sys/fs/zfs.h>
75 #include <sys/zfs_ioctl.h>
76 #include <sys/mkdev.h>
77 #include <sys/zil.h>
78 #include <sys/refcount.h>
79 #include <sys/zfs_znode.h>
80 #include <sys/zfs_rlock.h>
81 #include <sys/vdev_disk.h>
82 #include <sys/vdev_impl.h>
83 #include <sys/vdev_raidz.h>
84 #include <sys/zvol.h>
85 #include <sys/dumphdr.h>
86 #include <sys/zil_impl.h>
87 #include <sys/dbuf.h>
88 #include <sys/dmu_tx.h>
89 #include <sys/zfeature.h>
90 #include <sys/zio_checksum.h>
91
92 #include "zfs_namecheck.h"
93
94 void *zfsdev_state;
95 static char *zvol_tag = "zvol_tag";
96
97 #define ZVOL_DUMPSIZE "dumpsize"
98
99 /*
100 * This lock protects the zfsdev_state structure from being modified
101 * while it's being used, e.g. an open that comes in before a create
102 * finishes. It also protects temporary opens of the dataset so that,
103 * e.g., an open doesn't get a spurious EBUSY.
104 */
105 kmutex_t zfsdev_state_lock;
106 static uint32_t zvol_minors;
107
108 typedef struct zvol_extent {
109 list_node_t ze_node;
110 dva_t ze_dva; /* dva associated with this extent */
111 uint64_t ze_nblks; /* number of blocks in extent */
112 } zvol_extent_t;
113
114 /*
115 * The in-core state of each volume.
116 */
117 typedef struct zvol_state {
118 char zv_name[MAXPATHLEN]; /* pool/dd name */
119 uint64_t zv_volsize; /* amount of space we advertise */
120 uint64_t zv_volblocksize; /* volume block size */
121 minor_t zv_minor; /* minor number */
122 uint8_t zv_min_bs; /* minimum addressable block shift */
123 uint8_t zv_flags; /* readonly, dumpified, etc. */
124 objset_t *zv_objset; /* objset handle */
125 uint32_t zv_open_count[OTYPCNT]; /* open counts */
126 uint32_t zv_total_opens; /* total open count */
127 zilog_t *zv_zilog; /* ZIL handle */
128 list_t zv_extents; /* List of extents for dump */
129 znode_t zv_znode; /* for range locking */
130 dmu_buf_t *zv_dbuf; /* bonus handle */
131 } zvol_state_t;
132
133 /*
134 * zvol specific flags
135 */
136 #define ZVOL_RDONLY 0x1
137 #define ZVOL_DUMPIFIED 0x2
138 #define ZVOL_EXCL 0x4
139 #define ZVOL_WCE 0x8
140
141 /*
142 * zvol maximum transfer in one DMU tx.
143 */
144 int zvol_maxphys = DMU_MAX_ACCESS/2;
145
146 /*
147 * Toggle unmap functionality.
148 */
149 boolean_t zvol_unmap_enabled = B_TRUE;
150
151 /*
152 * If true, unmaps requested as synchronous are executed synchronously,
153 * otherwise all unmaps are asynchronous.
154 */
155 boolean_t zvol_unmap_sync_enabled = B_FALSE;
156
157 extern int zfs_set_prop_nvlist(const char *, zprop_source_t,
158 nvlist_t *, nvlist_t *);
159 static int zvol_remove_zv(zvol_state_t *);
160 static int zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio);
161 static int zvol_dumpify(zvol_state_t *zv);
162 static int zvol_dump_fini(zvol_state_t *zv);
163 static int zvol_dump_init(zvol_state_t *zv, boolean_t resize);
164
165 static void
166 zvol_size_changed(zvol_state_t *zv, uint64_t volsize)
167 {
168 dev_t dev = makedevice(ddi_driver_major(zfs_dip), zv->zv_minor);
169
170 zv->zv_volsize = volsize;
171 VERIFY(ddi_prop_update_int64(dev, zfs_dip,
172 "Size", volsize) == DDI_SUCCESS);
173 VERIFY(ddi_prop_update_int64(dev, zfs_dip,
174 "Nblocks", lbtodb(volsize)) == DDI_SUCCESS);
175
176 /* Notify specfs to invalidate the cached size */
177 spec_size_invalidate(dev, VBLK);
178 spec_size_invalidate(dev, VCHR);
179 }
180
181 int
182 zvol_check_volsize(uint64_t volsize, uint64_t blocksize)
183 {
184 if (volsize == 0)
185 return (SET_ERROR(EINVAL));
186
187 if (volsize % blocksize != 0)
188 return (SET_ERROR(EINVAL));
189
190 #ifdef _ILP32
191 if (volsize - 1 > SPEC_MAXOFFSET_T)
192 return (SET_ERROR(EOVERFLOW));
193 #endif
194 return (0);
195 }
196
197 int
198 zvol_check_volblocksize(uint64_t volblocksize)
199 {
200 if (volblocksize < SPA_MINBLOCKSIZE ||
201 volblocksize > SPA_OLD_MAXBLOCKSIZE ||
202 !ISP2(volblocksize))
203 return (SET_ERROR(EDOM));
204
205 return (0);
206 }
207
208 int
209 zvol_get_stats(objset_t *os, nvlist_t *nv)
210 {
211 int error;
212 dmu_object_info_t doi;
213 uint64_t val;
214
215 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &val);
216 if (error)
217 return (error);
218
219 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLSIZE, val);
220
221 error = dmu_object_info(os, ZVOL_OBJ, &doi);
222
223 if (error == 0) {
224 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLBLOCKSIZE,
225 doi.doi_data_block_size);
226 }
227
228 return (error);
229 }
230
231 static zvol_state_t *
232 zvol_minor_lookup(const char *name)
233 {
234 minor_t minor;
235 zvol_state_t *zv;
236
237 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
238
239 for (minor = 1; minor <= ZFSDEV_MAX_MINOR; minor++) {
240 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
241 if (zv == NULL)
242 continue;
243 if (strcmp(zv->zv_name, name) == 0)
244 return (zv);
245 }
246
247 return (NULL);
248 }
249
250 /* extent mapping arg */
251 struct maparg {
252 zvol_state_t *ma_zv;
253 uint64_t ma_blks;
254 };
255
256 /*ARGSUSED*/
257 static int
258 zvol_map_block(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
259 const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
260 {
261 struct maparg *ma = arg;
262 zvol_extent_t *ze;
263 int bs = ma->ma_zv->zv_volblocksize;
264
265 if (bp == NULL || BP_IS_HOLE(bp) ||
266 zb->zb_object != ZVOL_OBJ || zb->zb_level != 0)
267 return (0);
268
269 VERIFY(!BP_IS_EMBEDDED(bp));
270
271 VERIFY3U(ma->ma_blks, ==, zb->zb_blkid);
272 ma->ma_blks++;
273
274 /* Abort immediately if we have encountered gang blocks */
275 if (BP_IS_GANG(bp))
276 return (SET_ERROR(EFRAGS));
277
278 /*
279 * See if the block is at the end of the previous extent.
280 */
281 ze = list_tail(&ma->ma_zv->zv_extents);
282 if (ze &&
283 DVA_GET_VDEV(BP_IDENTITY(bp)) == DVA_GET_VDEV(&ze->ze_dva) &&
284 DVA_GET_OFFSET(BP_IDENTITY(bp)) ==
285 DVA_GET_OFFSET(&ze->ze_dva) + ze->ze_nblks * bs) {
286 ze->ze_nblks++;
287 return (0);
288 }
289
290 dprintf_bp(bp, "%s", "next blkptr:");
291
292 /* start a new extent */
293 ze = kmem_zalloc(sizeof (zvol_extent_t), KM_SLEEP);
294 ze->ze_dva = bp->blk_dva[0]; /* structure assignment */
295 ze->ze_nblks = 1;
296 list_insert_tail(&ma->ma_zv->zv_extents, ze);
297 return (0);
298 }
299
300 static void
301 zvol_free_extents(zvol_state_t *zv)
302 {
303 zvol_extent_t *ze;
304
305 while (ze = list_head(&zv->zv_extents)) {
306 list_remove(&zv->zv_extents, ze);
307 kmem_free(ze, sizeof (zvol_extent_t));
308 }
309 }
310
311 static int
312 zvol_get_lbas(zvol_state_t *zv)
313 {
314 objset_t *os = zv->zv_objset;
315 struct maparg ma;
316 int err;
317
318 ma.ma_zv = zv;
319 ma.ma_blks = 0;
320 zvol_free_extents(zv);
321
322 /* commit any in-flight changes before traversing the dataset */
323 txg_wait_synced(dmu_objset_pool(os), 0);
324 err = traverse_dataset(dmu_objset_ds(os), 0,
325 TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA, zvol_map_block, &ma);
326 if (err || ma.ma_blks != (zv->zv_volsize / zv->zv_volblocksize)) {
327 zvol_free_extents(zv);
328 return (err ? err : EIO);
329 }
330
331 return (0);
332 }
333
334 /* ARGSUSED */
335 void
336 zvol_create_cb(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx)
337 {
338 zfs_creat_t *zct = arg;
339 nvlist_t *nvprops = zct->zct_props;
340 int error;
341 uint64_t volblocksize, volsize;
342
343 VERIFY(nvlist_lookup_uint64(nvprops,
344 zfs_prop_to_name(ZFS_PROP_VOLSIZE), &volsize) == 0);
345 if (nvlist_lookup_uint64(nvprops,
346 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &volblocksize) != 0)
347 volblocksize = zfs_prop_default_numeric(ZFS_PROP_VOLBLOCKSIZE);
348
349 /*
350 * These properties must be removed from the list so the generic
351 * property setting step won't apply to them.
352 */
353 VERIFY(nvlist_remove_all(nvprops,
354 zfs_prop_to_name(ZFS_PROP_VOLSIZE)) == 0);
355 (void) nvlist_remove_all(nvprops,
356 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE));
357
358 error = dmu_object_claim(os, ZVOL_OBJ, DMU_OT_ZVOL, volblocksize,
359 DMU_OT_NONE, 0, tx);
360 ASSERT(error == 0);
361
362 error = zap_create_claim(os, ZVOL_ZAP_OBJ, DMU_OT_ZVOL_PROP,
363 DMU_OT_NONE, 0, tx);
364 ASSERT(error == 0);
365
366 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize, tx);
367 ASSERT(error == 0);
368 }
369
370 /*
371 * Replay a TX_TRUNCATE ZIL transaction if asked. TX_TRUNCATE is how we
372 * implement DKIOCFREE/free-long-range.
373 */
374 static int
375 zvol_replay_truncate(zvol_state_t *zv, lr_truncate_t *lr, boolean_t byteswap)
376 {
377 uint64_t offset, length;
378
379 if (byteswap)
380 byteswap_uint64_array(lr, sizeof (*lr));
381
382 offset = lr->lr_offset;
383 length = lr->lr_length;
384
385 return (dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, offset, length));
386 }
387
388 /*
389 * Replay a TX_WRITE ZIL transaction that didn't get committed
390 * after a system failure
391 */
392 static int
393 zvol_replay_write(zvol_state_t *zv, lr_write_t *lr, boolean_t byteswap)
394 {
395 objset_t *os = zv->zv_objset;
396 char *data = (char *)(lr + 1); /* data follows lr_write_t */
397 uint64_t offset, length;
398 dmu_tx_t *tx;
399 int error;
400
401 if (byteswap)
402 byteswap_uint64_array(lr, sizeof (*lr));
403
404 offset = lr->lr_offset;
405 length = lr->lr_length;
406
407 /* If it's a dmu_sync() block, write the whole block */
408 if (lr->lr_common.lrc_reclen == sizeof (lr_write_t)) {
409 uint64_t blocksize = BP_GET_LSIZE(&lr->lr_blkptr);
410 if (length < blocksize) {
411 offset -= offset % blocksize;
412 length = blocksize;
413 }
414 }
415
416 tx = dmu_tx_create(os);
417 dmu_tx_hold_write(tx, ZVOL_OBJ, offset, length);
418 error = dmu_tx_assign(tx, TXG_WAIT);
419 if (error) {
420 dmu_tx_abort(tx);
421 } else {
422 dmu_write(os, ZVOL_OBJ, offset, length, data, tx);
423 dmu_tx_commit(tx);
424 }
425
426 return (error);
427 }
428
429 /* ARGSUSED */
430 static int
431 zvol_replay_err(zvol_state_t *zv, lr_t *lr, boolean_t byteswap)
432 {
433 return (SET_ERROR(ENOTSUP));
434 }
435
436 /*
437 * Callback vectors for replaying records.
438 * Only TX_WRITE and TX_TRUNCATE are needed for zvol.
439 */
440 zil_replay_func_t *zvol_replay_vector[TX_MAX_TYPE] = {
441 zvol_replay_err, /* 0 no such transaction type */
442 zvol_replay_err, /* TX_CREATE */
443 zvol_replay_err, /* TX_MKDIR */
444 zvol_replay_err, /* TX_MKXATTR */
445 zvol_replay_err, /* TX_SYMLINK */
446 zvol_replay_err, /* TX_REMOVE */
447 zvol_replay_err, /* TX_RMDIR */
448 zvol_replay_err, /* TX_LINK */
449 zvol_replay_err, /* TX_RENAME */
450 zvol_replay_write, /* TX_WRITE */
451 zvol_replay_truncate, /* TX_TRUNCATE */
452 zvol_replay_err, /* TX_SETATTR */
453 zvol_replay_err, /* TX_ACL */
454 zvol_replay_err, /* TX_CREATE_ACL */
455 zvol_replay_err, /* TX_CREATE_ATTR */
456 zvol_replay_err, /* TX_CREATE_ACL_ATTR */
457 zvol_replay_err, /* TX_MKDIR_ACL */
458 zvol_replay_err, /* TX_MKDIR_ATTR */
459 zvol_replay_err, /* TX_MKDIR_ACL_ATTR */
460 zvol_replay_err, /* TX_WRITE2 */
461 };
462
463 int
464 zvol_name2minor(const char *name, minor_t *minor)
465 {
466 zvol_state_t *zv;
467
468 mutex_enter(&zfsdev_state_lock);
469 zv = zvol_minor_lookup(name);
470 if (minor && zv)
471 *minor = zv->zv_minor;
472 mutex_exit(&zfsdev_state_lock);
473 return (zv ? 0 : -1);
474 }
475
476 /*
477 * Create a minor node (plus a whole lot more) for the specified volume.
478 */
479 int
480 zvol_create_minor(const char *name)
481 {
482 zfs_soft_state_t *zs;
483 zvol_state_t *zv;
484 objset_t *os;
485 dmu_object_info_t doi;
486 minor_t minor = 0;
487 char chrbuf[30], blkbuf[30];
488 int error;
489
490 mutex_enter(&zfsdev_state_lock);
491
492 if (zvol_minor_lookup(name) != NULL) {
493 mutex_exit(&zfsdev_state_lock);
494 return (SET_ERROR(EEXIST));
495 }
496
497 /* lie and say we're read-only */
498 error = dmu_objset_own(name, DMU_OST_ZVOL, B_TRUE, FTAG, &os);
499
500 if (error) {
501 mutex_exit(&zfsdev_state_lock);
502 return (error);
503 }
504
505 if ((minor = zfsdev_minor_alloc()) == 0) {
506 dmu_objset_disown(os, FTAG);
507 mutex_exit(&zfsdev_state_lock);
508 return (SET_ERROR(ENXIO));
509 }
510
511 if (ddi_soft_state_zalloc(zfsdev_state, minor) != DDI_SUCCESS) {
512 dmu_objset_disown(os, FTAG);
513 mutex_exit(&zfsdev_state_lock);
514 return (SET_ERROR(EAGAIN));
515 }
516 (void) ddi_prop_update_string(minor, zfs_dip, ZVOL_PROP_NAME,
517 (char *)name);
518
519 (void) snprintf(chrbuf, sizeof (chrbuf), "%u,raw", minor);
520
521 if (ddi_create_minor_node(zfs_dip, chrbuf, S_IFCHR,
522 minor, DDI_PSEUDO, 0) == DDI_FAILURE) {
523 ddi_soft_state_free(zfsdev_state, minor);
524 dmu_objset_disown(os, FTAG);
525 mutex_exit(&zfsdev_state_lock);
526 return (SET_ERROR(EAGAIN));
527 }
528
529 (void) snprintf(blkbuf, sizeof (blkbuf), "%u", minor);
530
531 if (ddi_create_minor_node(zfs_dip, blkbuf, S_IFBLK,
532 minor, DDI_PSEUDO, 0) == DDI_FAILURE) {
533 ddi_remove_minor_node(zfs_dip, chrbuf);
534 ddi_soft_state_free(zfsdev_state, minor);
535 dmu_objset_disown(os, FTAG);
536 mutex_exit(&zfsdev_state_lock);
537 return (SET_ERROR(EAGAIN));
538 }
539
540 zs = ddi_get_soft_state(zfsdev_state, minor);
541 zs->zss_type = ZSST_ZVOL;
542 zv = zs->zss_data = kmem_zalloc(sizeof (zvol_state_t), KM_SLEEP);
543 (void) strlcpy(zv->zv_name, name, MAXPATHLEN);
544 zv->zv_min_bs = DEV_BSHIFT;
545 zv->zv_minor = minor;
546 zv->zv_objset = os;
547 if (dmu_objset_is_snapshot(os) || !spa_writeable(dmu_objset_spa(os)))
548 zv->zv_flags |= ZVOL_RDONLY;
549 mutex_init(&zv->zv_znode.z_range_lock, NULL, MUTEX_DEFAULT, NULL);
550 avl_create(&zv->zv_znode.z_range_avl, zfs_range_compare,
551 sizeof (rl_t), offsetof(rl_t, r_node));
552 list_create(&zv->zv_extents, sizeof (zvol_extent_t),
553 offsetof(zvol_extent_t, ze_node));
554 /* get and cache the blocksize */
555 error = dmu_object_info(os, ZVOL_OBJ, &doi);
556 ASSERT(error == 0);
557 zv->zv_volblocksize = doi.doi_data_block_size;
558
559 if (spa_writeable(dmu_objset_spa(os))) {
560 if (zil_replay_disable)
561 zil_destroy(dmu_objset_zil(os), B_FALSE);
562 else
563 zil_replay(os, zv, zvol_replay_vector);
564 }
565 dmu_objset_disown(os, FTAG);
566 zv->zv_objset = NULL;
567
568 zvol_minors++;
569
570 mutex_exit(&zfsdev_state_lock);
571
572 return (0);
573 }
574
575 /*
576 * Remove minor node for the specified volume.
577 */
578 static int
579 zvol_remove_zv(zvol_state_t *zv)
580 {
581 char nmbuf[20];
582 minor_t minor = zv->zv_minor;
583
584 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
585 if (zv->zv_total_opens != 0)
586 return (SET_ERROR(EBUSY));
587
588 (void) snprintf(nmbuf, sizeof (nmbuf), "%u,raw", minor);
589 ddi_remove_minor_node(zfs_dip, nmbuf);
590
591 (void) snprintf(nmbuf, sizeof (nmbuf), "%u", minor);
592 ddi_remove_minor_node(zfs_dip, nmbuf);
593
594 avl_destroy(&zv->zv_znode.z_range_avl);
595 mutex_destroy(&zv->zv_znode.z_range_lock);
596
597 kmem_free(zv, sizeof (zvol_state_t));
598
599 ddi_soft_state_free(zfsdev_state, minor);
600
601 zvol_minors--;
602 return (0);
603 }
604
605 int
606 zvol_remove_minor(const char *name)
607 {
608 zvol_state_t *zv;
609 int rc;
610
611 mutex_enter(&zfsdev_state_lock);
612 if ((zv = zvol_minor_lookup(name)) == NULL) {
613 mutex_exit(&zfsdev_state_lock);
614 return (SET_ERROR(ENXIO));
615 }
616 rc = zvol_remove_zv(zv);
617 mutex_exit(&zfsdev_state_lock);
618 return (rc);
619 }
620
621 int
622 zvol_first_open(zvol_state_t *zv)
623 {
624 objset_t *os;
625 uint64_t volsize;
626 int error;
627 uint64_t readonly;
628
629 /* lie and say we're read-only */
630 error = dmu_objset_own(zv->zv_name, DMU_OST_ZVOL, B_TRUE,
631 zvol_tag, &os);
632 if (error)
633 return (error);
634
635 zv->zv_objset = os;
636 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize);
637 if (error) {
638 ASSERT(error == 0);
639 dmu_objset_disown(os, zvol_tag);
640 return (error);
641 }
642
643 error = dmu_bonus_hold(os, ZVOL_OBJ, zvol_tag, &zv->zv_dbuf);
644 if (error) {
645 dmu_objset_disown(os, zvol_tag);
646 return (error);
647 }
648
649 zvol_size_changed(zv, volsize);
650 zv->zv_zilog = zil_open(os, zvol_get_data);
651
652 VERIFY(dsl_prop_get_integer(zv->zv_name, "readonly", &readonly,
653 NULL) == 0);
654 if (readonly || dmu_objset_is_snapshot(os) ||
655 !spa_writeable(dmu_objset_spa(os)))
656 zv->zv_flags |= ZVOL_RDONLY;
657 else
658 zv->zv_flags &= ~ZVOL_RDONLY;
659 return (error);
660 }
661
662 void
663 zvol_last_close(zvol_state_t *zv)
664 {
665 zil_close(zv->zv_zilog);
666 zv->zv_zilog = NULL;
667
668 dmu_buf_rele(zv->zv_dbuf, zvol_tag);
669 zv->zv_dbuf = NULL;
670
671 /*
672 * Evict cached data
673 */
674 if (dsl_dataset_is_dirty(dmu_objset_ds(zv->zv_objset)) &&
675 !(zv->zv_flags & ZVOL_RDONLY))
676 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
677 dmu_objset_evict_dbufs(zv->zv_objset);
678
679 dmu_objset_disown(zv->zv_objset, zvol_tag);
680 zv->zv_objset = NULL;
681 }
682
683 int
684 zvol_prealloc(zvol_state_t *zv)
685 {
686 objset_t *os = zv->zv_objset;
687 dmu_tx_t *tx;
688 uint64_t refd, avail, usedobjs, availobjs;
689 uint64_t resid = zv->zv_volsize;
690 uint64_t off = 0;
691
692 /* Check the space usage before attempting to allocate the space */
693 dmu_objset_space(os, &refd, &avail, &usedobjs, &availobjs);
694 if (avail < zv->zv_volsize)
695 return (SET_ERROR(ENOSPC));
696
697 /* Free old extents if they exist */
698 zvol_free_extents(zv);
699
700 while (resid != 0) {
701 int error;
702 uint64_t bytes = MIN(resid, SPA_OLD_MAXBLOCKSIZE);
703
704 tx = dmu_tx_create(os);
705 dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes);
706 error = dmu_tx_assign(tx, TXG_WAIT);
707 if (error) {
708 dmu_tx_abort(tx);
709 (void) dmu_free_long_range(os, ZVOL_OBJ, 0, off);
710 return (error);
711 }
712 dmu_prealloc(os, ZVOL_OBJ, off, bytes, tx);
713 dmu_tx_commit(tx);
714 off += bytes;
715 resid -= bytes;
716 }
717 txg_wait_synced(dmu_objset_pool(os), 0);
718
719 return (0);
720 }
721
722 static int
723 zvol_update_volsize(objset_t *os, uint64_t volsize)
724 {
725 dmu_tx_t *tx;
726 int error;
727
728 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
729
730 tx = dmu_tx_create(os);
731 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
732 dmu_tx_mark_netfree(tx);
733 error = dmu_tx_assign(tx, TXG_WAIT);
734 if (error) {
735 dmu_tx_abort(tx);
736 return (error);
737 }
738
739 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1,
740 &volsize, tx);
741 dmu_tx_commit(tx);
742
743 if (error == 0)
744 error = dmu_free_long_range(os,
745 ZVOL_OBJ, volsize, DMU_OBJECT_END);
746 return (error);
747 }
748
749 void
750 zvol_remove_minors(const char *name)
751 {
752 zvol_state_t *zv;
753 char *namebuf;
754 minor_t minor;
755
756 namebuf = kmem_zalloc(strlen(name) + 2, KM_SLEEP);
757 (void) strncpy(namebuf, name, strlen(name));
758 (void) strcat(namebuf, "/");
759 mutex_enter(&zfsdev_state_lock);
760 for (minor = 1; minor <= ZFSDEV_MAX_MINOR; minor++) {
761
762 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
763 if (zv == NULL)
764 continue;
765 if (strncmp(namebuf, zv->zv_name, strlen(namebuf)) == 0)
766 (void) zvol_remove_zv(zv);
767 }
768 kmem_free(namebuf, strlen(name) + 2);
769
770 mutex_exit(&zfsdev_state_lock);
771 }
772
773 static int
774 zvol_update_live_volsize(zvol_state_t *zv, uint64_t volsize)
775 {
776 uint64_t old_volsize = 0ULL;
777 int error = 0;
778
779 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
780
781 /*
782 * Reinitialize the dump area to the new size. If we
783 * failed to resize the dump area then restore it back to
784 * its original size. We must set the new volsize prior
785 * to calling dumpvp_resize() to ensure that the devices'
786 * size(9P) is not visible by the dump subsystem.
787 */
788 old_volsize = zv->zv_volsize;
789 zvol_size_changed(zv, volsize);
790
791 if (zv->zv_flags & ZVOL_DUMPIFIED) {
792 if ((error = zvol_dumpify(zv)) != 0 ||
793 (error = dumpvp_resize()) != 0) {
794 int dumpify_error;
795
796 (void) zvol_update_volsize(zv->zv_objset, old_volsize);
797 zvol_size_changed(zv, old_volsize);
798 dumpify_error = zvol_dumpify(zv);
799 error = dumpify_error ? dumpify_error : error;
800 }
801 }
802
803 /*
804 * Generate a LUN expansion event.
805 */
806 if (error == 0) {
807 sysevent_id_t eid;
808 nvlist_t *attr;
809 char *physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
810
811 (void) snprintf(physpath, MAXPATHLEN, "%s%u", ZVOL_PSEUDO_DEV,
812 zv->zv_minor);
813
814 VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0);
815 VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0);
816
817 (void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS,
818 ESC_DEV_DLE, attr, &eid, DDI_SLEEP);
819
820 nvlist_free(attr);
821 kmem_free(physpath, MAXPATHLEN);
822 }
823 return (error);
824 }
825
826 int
827 zvol_set_volsize(const char *name, uint64_t volsize)
828 {
829 zvol_state_t *zv = NULL;
830 objset_t *os;
831 int error;
832 dmu_object_info_t doi;
833 uint64_t readonly;
834 boolean_t owned = B_FALSE;
835
836 error = dsl_prop_get_integer(name,
837 zfs_prop_to_name(ZFS_PROP_READONLY), &readonly, NULL);
838 if (error != 0)
839 return (error);
840 if (readonly)
841 return (SET_ERROR(EROFS));
842
843 mutex_enter(&zfsdev_state_lock);
844 zv = zvol_minor_lookup(name);
845
846 if (zv == NULL || zv->zv_objset == NULL) {
847 if ((error = dmu_objset_own(name, DMU_OST_ZVOL, B_FALSE,
848 FTAG, &os)) != 0) {
849 mutex_exit(&zfsdev_state_lock);
850 return (error);
851 }
852 owned = B_TRUE;
853 if (zv != NULL)
854 zv->zv_objset = os;
855 } else {
856 os = zv->zv_objset;
857 }
858
859 if ((error = dmu_object_info(os, ZVOL_OBJ, &doi)) != 0 ||
860 (error = zvol_check_volsize(volsize, doi.doi_data_block_size)) != 0)
861 goto out;
862
863 error = zvol_update_volsize(os, volsize);
864
865 if (error == 0 && zv != NULL)
866 error = zvol_update_live_volsize(zv, volsize);
867 out:
868 if (owned) {
869 dmu_objset_disown(os, FTAG);
870 if (zv != NULL)
871 zv->zv_objset = NULL;
872 }
873 mutex_exit(&zfsdev_state_lock);
874 return (error);
875 }
876
877 /*ARGSUSED*/
878 int
879 zvol_open(dev_t *devp, int flag, int otyp, cred_t *cr)
880 {
881 zvol_state_t *zv;
882 int err = 0;
883
884 mutex_enter(&zfsdev_state_lock);
885
886 zv = zfsdev_get_soft_state(getminor(*devp), ZSST_ZVOL);
887 if (zv == NULL) {
888 mutex_exit(&zfsdev_state_lock);
889 return (SET_ERROR(ENXIO));
890 }
891
892 if (zv->zv_total_opens == 0)
893 err = zvol_first_open(zv);
894 if (err) {
895 mutex_exit(&zfsdev_state_lock);
896 return (err);
897 }
898 if ((flag & FWRITE) && (zv->zv_flags & ZVOL_RDONLY)) {
899 err = SET_ERROR(EROFS);
900 goto out;
901 }
902 if (zv->zv_flags & ZVOL_EXCL) {
903 err = SET_ERROR(EBUSY);
904 goto out;
905 }
906 if (flag & FEXCL) {
907 if (zv->zv_total_opens != 0) {
908 err = SET_ERROR(EBUSY);
909 goto out;
910 }
911 zv->zv_flags |= ZVOL_EXCL;
912 }
913
914 if (zv->zv_open_count[otyp] == 0 || otyp == OTYP_LYR) {
915 zv->zv_open_count[otyp]++;
916 zv->zv_total_opens++;
917 }
918 mutex_exit(&zfsdev_state_lock);
919
920 return (err);
921 out:
922 if (zv->zv_total_opens == 0)
923 zvol_last_close(zv);
924 mutex_exit(&zfsdev_state_lock);
925 return (err);
926 }
927
928 /*ARGSUSED*/
929 int
930 zvol_close(dev_t dev, int flag, int otyp, cred_t *cr)
931 {
932 minor_t minor = getminor(dev);
933 zvol_state_t *zv;
934 int error = 0;
935
936 mutex_enter(&zfsdev_state_lock);
937
938 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
939 if (zv == NULL) {
940 mutex_exit(&zfsdev_state_lock);
941 return (SET_ERROR(ENXIO));
942 }
943
944 if (zv->zv_flags & ZVOL_EXCL) {
945 ASSERT(zv->zv_total_opens == 1);
946 zv->zv_flags &= ~ZVOL_EXCL;
947 }
948
949 /*
950 * If the open count is zero, this is a spurious close.
951 * That indicates a bug in the kernel / DDI framework.
952 */
953 ASSERT(zv->zv_open_count[otyp] != 0);
954 ASSERT(zv->zv_total_opens != 0);
955
956 /*
957 * You may get multiple opens, but only one close.
958 */
959 zv->zv_open_count[otyp]--;
960 zv->zv_total_opens--;
961
962 if (zv->zv_total_opens == 0)
963 zvol_last_close(zv);
964
965 mutex_exit(&zfsdev_state_lock);
966 return (error);
967 }
968
969 static void
970 zvol_get_done(zgd_t *zgd, int error)
971 {
972 if (zgd->zgd_db)
973 dmu_buf_rele(zgd->zgd_db, zgd);
974
975 zfs_range_unlock(zgd->zgd_rl);
976
977 if (error == 0 && zgd->zgd_bp)
978 zil_add_block(zgd->zgd_zilog, zgd->zgd_bp);
979
980 kmem_free(zgd, sizeof (zgd_t));
981 }
982
983 /*
984 * Get data to generate a TX_WRITE intent log record.
985 */
986 static int
987 zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
988 {
989 zvol_state_t *zv = arg;
990 objset_t *os = zv->zv_objset;
991 uint64_t object = ZVOL_OBJ;
992 uint64_t offset = lr->lr_offset;
993 uint64_t size = lr->lr_length; /* length of user data */
994 dmu_buf_t *db;
995 zgd_t *zgd;
996 int error;
997
998 ASSERT(zio != NULL);
999 ASSERT(size != 0);
1000
1001 zgd = kmem_zalloc(sizeof (zgd_t), KM_SLEEP);
1002 zgd->zgd_zilog = zv->zv_zilog;
1003 zgd->zgd_rl = zfs_range_lock(&zv->zv_znode, offset, size, RL_READER);
1004
1005 /*
1006 * Write records come in two flavors: immediate and indirect.
1007 * For small writes it's cheaper to store the data with the
1008 * log record (immediate); for large writes it's cheaper to
1009 * sync the data and get a pointer to it (indirect) so that
1010 * we don't have to write the data twice.
1011 */
1012 if (buf != NULL) { /* immediate write */
1013 error = dmu_read(os, object, offset, size, buf,
1014 DMU_READ_NO_PREFETCH);
1015 } else {
1016 size = zv->zv_volblocksize;
1017 offset = P2ALIGN(offset, size);
1018 error = dmu_buf_hold(os, object, offset, zgd, &db,
1019 DMU_READ_NO_PREFETCH);
1020 if (error == 0) {
1021 blkptr_t *bp = &lr->lr_blkptr;
1022
1023 zgd->zgd_db = db;
1024 zgd->zgd_bp = bp;
1025
1026 ASSERT(db->db_offset == offset);
1027 ASSERT(db->db_size == size);
1028
1029 error = dmu_sync(zio, lr->lr_common.lrc_txg,
1030 zvol_get_done, zgd);
1031
1032 if (error == 0)
1033 return (0);
1034 }
1035 }
1036
1037 zvol_get_done(zgd, error);
1038
1039 return (error);
1040 }
1041
1042 /*
1043 * zvol_log_write() handles synchronous writes using TX_WRITE ZIL transactions.
1044 *
1045 * We store data in the log buffers if it's small enough.
1046 * Otherwise we will later flush the data out via dmu_sync().
1047 */
1048 ssize_t zvol_immediate_write_sz = 32768;
1049
1050 static void
1051 zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, offset_t off, ssize_t resid,
1052 boolean_t sync)
1053 {
1054 uint32_t blocksize = zv->zv_volblocksize;
1055 zilog_t *zilog = zv->zv_zilog;
1056 itx_wr_state_t write_state;
1057
1058 if (zil_replaying(zilog, tx))
1059 return;
1060
1061 if (zilog->zl_logbias == ZFS_LOGBIAS_THROUGHPUT)
1062 write_state = WR_INDIRECT;
1063 else if (!spa_has_slogs(zilog->zl_spa) &&
1064 resid >= blocksize && blocksize > zvol_immediate_write_sz)
1065 write_state = WR_INDIRECT;
1066 else if (sync)
1067 write_state = WR_COPIED;
1068 else
1069 write_state = WR_NEED_COPY;
1070
1071 while (resid) {
1072 itx_t *itx;
1073 lr_write_t *lr;
1074 itx_wr_state_t wr_state = write_state;
1075 ssize_t len = resid;
1076
1077 if (wr_state == WR_COPIED && resid > ZIL_MAX_COPIED_DATA)
1078 wr_state = WR_NEED_COPY;
1079 else if (wr_state == WR_INDIRECT)
1080 len = MIN(blocksize - P2PHASE(off, blocksize), resid);
1081
1082 itx = zil_itx_create(TX_WRITE, sizeof (*lr) +
1083 (wr_state == WR_COPIED ? len : 0));
1084 lr = (lr_write_t *)&itx->itx_lr;
1085 if (wr_state == WR_COPIED && dmu_read(zv->zv_objset,
1086 ZVOL_OBJ, off, len, lr + 1, DMU_READ_NO_PREFETCH) != 0) {
1087 zil_itx_destroy(itx);
1088 itx = zil_itx_create(TX_WRITE, sizeof (*lr));
1089 lr = (lr_write_t *)&itx->itx_lr;
1090 wr_state = WR_NEED_COPY;
1091 }
1092
1093 itx->itx_wr_state = wr_state;
1094 lr->lr_foid = ZVOL_OBJ;
1095 lr->lr_offset = off;
1096 lr->lr_length = len;
1097 lr->lr_blkoff = 0;
1098 BP_ZERO(&lr->lr_blkptr);
1099
1100 itx->itx_private = zv;
1101 itx->itx_sync = sync;
1102
1103 zil_itx_assign(zilog, itx, tx);
1104
1105 off += len;
1106 resid -= len;
1107 }
1108 }
1109
1110 static int
1111 zvol_dumpio_vdev(vdev_t *vd, void *addr, uint64_t offset, uint64_t origoffset,
1112 uint64_t size, boolean_t doread, boolean_t isdump)
1113 {
1114 vdev_disk_t *dvd;
1115 int c;
1116 int numerrors = 0;
1117
1118 if (vd->vdev_ops == &vdev_mirror_ops ||
1119 vd->vdev_ops == &vdev_replacing_ops ||
1120 vd->vdev_ops == &vdev_spare_ops) {
1121 for (c = 0; c < vd->vdev_children; c++) {
1122 int err = zvol_dumpio_vdev(vd->vdev_child[c],
1123 addr, offset, origoffset, size, doread, isdump);
1124 if (err != 0) {
1125 numerrors++;
1126 } else if (doread) {
1127 break;
1128 }
1129 }
1130 }
1131
1132 if (!vd->vdev_ops->vdev_op_leaf && vd->vdev_ops != &vdev_raidz_ops)
1133 return (numerrors < vd->vdev_children ? 0 : EIO);
1134
1135 if (doread && !vdev_readable(vd))
1136 return (SET_ERROR(EIO));
1137 else if (!doread && !vdev_writeable(vd))
1138 return (SET_ERROR(EIO));
1139
1140 if (vd->vdev_ops == &vdev_raidz_ops) {
1141 return (vdev_raidz_physio(vd,
1142 addr, size, offset, origoffset, doread, isdump));
1143 }
1144
1145 offset += VDEV_LABEL_START_SIZE;
1146
1147 if (ddi_in_panic() || isdump) {
1148 ASSERT(!doread);
1149 if (doread)
1150 return (SET_ERROR(EIO));
1151 dvd = vd->vdev_tsd;
1152 ASSERT3P(dvd, !=, NULL);
1153 return (ldi_dump(dvd->vd_lh, addr, lbtodb(offset),
1154 lbtodb(size)));
1155 } else {
1156 dvd = vd->vdev_tsd;
1157 ASSERT3P(dvd, !=, NULL);
1158 return (vdev_disk_ldi_physio(dvd->vd_lh, addr, size,
1159 offset, doread ? B_READ : B_WRITE));
1160 }
1161 }
1162
1163 static int
1164 zvol_dumpio(zvol_state_t *zv, void *addr, uint64_t offset, uint64_t size,
1165 boolean_t doread, boolean_t isdump)
1166 {
1167 vdev_t *vd;
1168 int error;
1169 zvol_extent_t *ze;
1170 spa_t *spa = dmu_objset_spa(zv->zv_objset);
1171
1172 /* Must be sector aligned, and not stradle a block boundary. */
1173 if (P2PHASE(offset, DEV_BSIZE) || P2PHASE(size, DEV_BSIZE) ||
1174 P2BOUNDARY(offset, size, zv->zv_volblocksize)) {
1175 return (SET_ERROR(EINVAL));
1176 }
1177 ASSERT(size <= zv->zv_volblocksize);
1178
1179 /* Locate the extent this belongs to */
1180 ze = list_head(&zv->zv_extents);
1181 while (offset >= ze->ze_nblks * zv->zv_volblocksize) {
1182 offset -= ze->ze_nblks * zv->zv_volblocksize;
1183 ze = list_next(&zv->zv_extents, ze);
1184 }
1185
1186 if (ze == NULL)
1187 return (SET_ERROR(EINVAL));
1188
1189 if (!ddi_in_panic())
1190 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
1191
1192 vd = vdev_lookup_top(spa, DVA_GET_VDEV(&ze->ze_dva));
1193 offset += DVA_GET_OFFSET(&ze->ze_dva);
1194 error = zvol_dumpio_vdev(vd, addr, offset, DVA_GET_OFFSET(&ze->ze_dva),
1195 size, doread, isdump);
1196
1197 if (!ddi_in_panic())
1198 spa_config_exit(spa, SCL_STATE, FTAG);
1199
1200 return (error);
1201 }
1202
1203 int
1204 zvol_strategy(buf_t *bp)
1205 {
1206 zfs_soft_state_t *zs = NULL;
1207 zvol_state_t *zv;
1208 uint64_t off, volsize;
1209 size_t resid;
1210 char *addr;
1211 objset_t *os;
1212 rl_t *rl;
1213 int error = 0;
1214 boolean_t doread = bp->b_flags & B_READ;
1215 boolean_t is_dumpified;
1216 boolean_t sync;
1217
1218 if (getminor(bp->b_edev) == 0) {
1219 error = SET_ERROR(EINVAL);
1220 } else {
1221 zs = ddi_get_soft_state(zfsdev_state, getminor(bp->b_edev));
1222 if (zs == NULL)
1223 error = SET_ERROR(ENXIO);
1224 else if (zs->zss_type != ZSST_ZVOL)
1225 error = SET_ERROR(EINVAL);
1226 }
1227
1228 if (error) {
1229 bioerror(bp, error);
1230 biodone(bp);
1231 return (0);
1232 }
1233
1234 zv = zs->zss_data;
1235
1236 if (!(bp->b_flags & B_READ) && (zv->zv_flags & ZVOL_RDONLY)) {
1237 bioerror(bp, EROFS);
1238 biodone(bp);
1239 return (0);
1240 }
1241
1242 off = ldbtob(bp->b_blkno);
1243 volsize = zv->zv_volsize;
1244
1245 os = zv->zv_objset;
1246 ASSERT(os != NULL);
1247
1248 bp_mapin(bp);
1249 addr = bp->b_un.b_addr;
1250 resid = bp->b_bcount;
1251
1252 if (resid > 0 && (off < 0 || off >= volsize)) {
1253 bioerror(bp, EIO);
1254 biodone(bp);
1255 return (0);
1256 }
1257
1258 is_dumpified = zv->zv_flags & ZVOL_DUMPIFIED;
1259 sync = ((!(bp->b_flags & B_ASYNC) &&
1260 !(zv->zv_flags & ZVOL_WCE)) ||
1261 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS)) &&
1262 !doread && !is_dumpified;
1263
1264 /*
1265 * There must be no buffer changes when doing a dmu_sync() because
1266 * we can't change the data whilst calculating the checksum.
1267 */
1268 rl = zfs_range_lock(&zv->zv_znode, off, resid,
1269 doread ? RL_READER : RL_WRITER);
1270
1271 while (resid != 0 && off < volsize) {
1272 size_t size = MIN(resid, zvol_maxphys);
1273 if (is_dumpified) {
1274 size = MIN(size, P2END(off, zv->zv_volblocksize) - off);
1275 error = zvol_dumpio(zv, addr, off, size,
1276 doread, B_FALSE);
1277 } else if (doread) {
1278 error = dmu_read(os, ZVOL_OBJ, off, size, addr,
1279 DMU_READ_PREFETCH);
1280 } else {
1281 dmu_tx_t *tx = dmu_tx_create(os);
1282 dmu_tx_hold_write(tx, ZVOL_OBJ, off, size);
1283 error = dmu_tx_assign(tx, TXG_WAIT);
1284 if (error) {
1285 dmu_tx_abort(tx);
1286 } else {
1287 dmu_write(os, ZVOL_OBJ, off, size, addr, tx);
1288 zvol_log_write(zv, tx, off, size, sync);
1289 dmu_tx_commit(tx);
1290 }
1291 }
1292 if (error) {
1293 /* convert checksum errors into IO errors */
1294 if (error == ECKSUM)
1295 error = SET_ERROR(EIO);
1296 break;
1297 }
1298 off += size;
1299 addr += size;
1300 resid -= size;
1301 }
1302 zfs_range_unlock(rl);
1303
1304 if ((bp->b_resid = resid) == bp->b_bcount)
1305 bioerror(bp, off > volsize ? EINVAL : error);
1306
1307 if (sync)
1308 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1309 biodone(bp);
1310
1311 return (0);
1312 }
1313
1314 /*
1315 * Set the buffer count to the zvol maximum transfer.
1316 * Using our own routine instead of the default minphys()
1317 * means that for larger writes we write bigger buffers on X86
1318 * (128K instead of 56K) and flush the disk write cache less often
1319 * (every zvol_maxphys - currently 1MB) instead of minphys (currently
1320 * 56K on X86 and 128K on sparc).
1321 */
1322 void
1323 zvol_minphys(struct buf *bp)
1324 {
1325 if (bp->b_bcount > zvol_maxphys)
1326 bp->b_bcount = zvol_maxphys;
1327 }
1328
1329 int
1330 zvol_dump(dev_t dev, caddr_t addr, daddr_t blkno, int nblocks)
1331 {
1332 minor_t minor = getminor(dev);
1333 zvol_state_t *zv;
1334 int error = 0;
1335 uint64_t size;
1336 uint64_t boff;
1337 uint64_t resid;
1338
1339 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1340 if (zv == NULL)
1341 return (SET_ERROR(ENXIO));
1342
1343 if ((zv->zv_flags & ZVOL_DUMPIFIED) == 0)
1344 return (SET_ERROR(EINVAL));
1345
1346 boff = ldbtob(blkno);
1347 resid = ldbtob(nblocks);
1348
1349 VERIFY3U(boff + resid, <=, zv->zv_volsize);
1350
1351 while (resid) {
1352 size = MIN(resid, P2END(boff, zv->zv_volblocksize) - boff);
1353 error = zvol_dumpio(zv, addr, boff, size, B_FALSE, B_TRUE);
1354 if (error)
1355 break;
1356 boff += size;
1357 addr += size;
1358 resid -= size;
1359 }
1360
1361 return (error);
1362 }
1363
1364 /*ARGSUSED*/
1365 int
1366 zvol_read(dev_t dev, uio_t *uio, cred_t *cr)
1367 {
1368 minor_t minor = getminor(dev);
1369 zvol_state_t *zv;
1370 uint64_t volsize;
1371 rl_t *rl;
1372 int error = 0;
1373
1374 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1375 if (zv == NULL)
1376 return (SET_ERROR(ENXIO));
1377
1378 volsize = zv->zv_volsize;
1379 if (uio->uio_resid > 0 &&
1380 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize))
1381 return (SET_ERROR(EIO));
1382
1383 if (zv->zv_flags & ZVOL_DUMPIFIED) {
1384 error = physio(zvol_strategy, NULL, dev, B_READ,
1385 zvol_minphys, uio);
1386 return (error);
1387 }
1388
1389 rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid,
1390 RL_READER);
1391 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) {
1392 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1);
1393
1394 /* don't read past the end */
1395 if (bytes > volsize - uio->uio_loffset)
1396 bytes = volsize - uio->uio_loffset;
1397
1398 error = dmu_read_uio(zv->zv_objset, ZVOL_OBJ, uio, bytes);
1399 if (error) {
1400 /* convert checksum errors into IO errors */
1401 if (error == ECKSUM)
1402 error = SET_ERROR(EIO);
1403 break;
1404 }
1405 }
1406 zfs_range_unlock(rl);
1407 return (error);
1408 }
1409
1410 /*ARGSUSED*/
1411 int
1412 zvol_write(dev_t dev, uio_t *uio, cred_t *cr)
1413 {
1414 minor_t minor = getminor(dev);
1415 zvol_state_t *zv;
1416 uint64_t volsize;
1417 rl_t *rl;
1418 int error = 0;
1419 boolean_t sync;
1420
1421 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1422 if (zv == NULL)
1423 return (SET_ERROR(ENXIO));
1424
1425 volsize = zv->zv_volsize;
1426 if (uio->uio_resid > 0 &&
1427 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize))
1428 return (SET_ERROR(EIO));
1429
1430 if (zv->zv_flags & ZVOL_DUMPIFIED) {
1431 error = physio(zvol_strategy, NULL, dev, B_WRITE,
1432 zvol_minphys, uio);
1433 return (error);
1434 }
1435
1436 sync = !(zv->zv_flags & ZVOL_WCE) ||
1437 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS);
1438
1439 rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid,
1440 RL_WRITER);
1441 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) {
1442 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1);
1443 uint64_t off = uio->uio_loffset;
1444 dmu_tx_t *tx = dmu_tx_create(zv->zv_objset);
1445
1446 if (bytes > volsize - off) /* don't write past the end */
1447 bytes = volsize - off;
1448
1449 dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes);
1450 error = dmu_tx_assign(tx, TXG_WAIT);
1451 if (error) {
1452 dmu_tx_abort(tx);
1453 break;
1454 }
1455 error = dmu_write_uio_dbuf(zv->zv_dbuf, uio, bytes, tx);
1456 if (error == 0)
1457 zvol_log_write(zv, tx, off, bytes, sync);
1458 dmu_tx_commit(tx);
1459
1460 if (error)
1461 break;
1462 }
1463 zfs_range_unlock(rl);
1464 if (sync)
1465 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1466 return (error);
1467 }
1468
1469 int
1470 zvol_getefi(void *arg, int flag, uint64_t vs, uint8_t bs)
1471 {
1472 struct uuid uuid = EFI_RESERVED;
1473 efi_gpe_t gpe = { 0 };
1474 uint32_t crc;
1475 dk_efi_t efi;
1476 int length;
1477 char *ptr;
1478
1479 if (ddi_copyin(arg, &efi, sizeof (dk_efi_t), flag))
1480 return (SET_ERROR(EFAULT));
1481 ptr = (char *)(uintptr_t)efi.dki_data_64;
1482 length = efi.dki_length;
1483 /*
1484 * Some clients may attempt to request a PMBR for the
1485 * zvol. Currently this interface will return EINVAL to
1486 * such requests. These requests could be supported by
1487 * adding a check for lba == 0 and consing up an appropriate
1488 * PMBR.
1489 */
1490 if (efi.dki_lba < 1 || efi.dki_lba > 2 || length <= 0)
1491 return (SET_ERROR(EINVAL));
1492
1493 gpe.efi_gpe_StartingLBA = LE_64(34ULL);
1494 gpe.efi_gpe_EndingLBA = LE_64((vs >> bs) - 1);
1495 UUID_LE_CONVERT(gpe.efi_gpe_PartitionTypeGUID, uuid);
1496
1497 if (efi.dki_lba == 1) {
1498 efi_gpt_t gpt = { 0 };
1499
1500 gpt.efi_gpt_Signature = LE_64(EFI_SIGNATURE);
1501 gpt.efi_gpt_Revision = LE_32(EFI_VERSION_CURRENT);
1502 gpt.efi_gpt_HeaderSize = LE_32(sizeof (gpt));
1503 gpt.efi_gpt_MyLBA = LE_64(1ULL);
1504 gpt.efi_gpt_FirstUsableLBA = LE_64(34ULL);
1505 gpt.efi_gpt_LastUsableLBA = LE_64((vs >> bs) - 1);
1506 gpt.efi_gpt_PartitionEntryLBA = LE_64(2ULL);
1507 gpt.efi_gpt_NumberOfPartitionEntries = LE_32(1);
1508 gpt.efi_gpt_SizeOfPartitionEntry =
1509 LE_32(sizeof (efi_gpe_t));
1510 CRC32(crc, &gpe, sizeof (gpe), -1U, crc32_table);
1511 gpt.efi_gpt_PartitionEntryArrayCRC32 = LE_32(~crc);
1512 CRC32(crc, &gpt, sizeof (gpt), -1U, crc32_table);
1513 gpt.efi_gpt_HeaderCRC32 = LE_32(~crc);
1514 if (ddi_copyout(&gpt, ptr, MIN(sizeof (gpt), length),
1515 flag))
1516 return (SET_ERROR(EFAULT));
1517 ptr += sizeof (gpt);
1518 length -= sizeof (gpt);
1519 }
1520 if (length > 0 && ddi_copyout(&gpe, ptr, MIN(sizeof (gpe),
1521 length), flag))
1522 return (SET_ERROR(EFAULT));
1523 return (0);
1524 }
1525
1526 /*
1527 * BEGIN entry points to allow external callers access to the volume.
1528 */
1529 /*
1530 * Return the volume parameters needed for access from an external caller.
1531 * These values are invariant as long as the volume is held open.
1532 */
1533 int
1534 zvol_get_volume_params(minor_t minor, uint64_t *blksize,
1535 uint64_t *max_xfer_len, void **minor_hdl, void **objset_hdl, void **zil_hdl,
1536 void **rl_hdl, void **bonus_hdl)
1537 {
1538 zvol_state_t *zv;
1539
1540 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1541 if (zv == NULL)
1542 return (SET_ERROR(ENXIO));
1543 if (zv->zv_flags & ZVOL_DUMPIFIED)
1544 return (SET_ERROR(ENXIO));
1545
1546 ASSERT(blksize && max_xfer_len && minor_hdl &&
1547 objset_hdl && zil_hdl && rl_hdl && bonus_hdl);
1548
1549 *blksize = zv->zv_volblocksize;
1550 *max_xfer_len = (uint64_t)zvol_maxphys;
1551 *minor_hdl = zv;
1552 *objset_hdl = zv->zv_objset;
1553 *zil_hdl = zv->zv_zilog;
1554 *rl_hdl = &zv->zv_znode;
1555 *bonus_hdl = zv->zv_dbuf;
1556 return (0);
1557 }
1558
1559 /*
1560 * Return the current volume size to an external caller.
1561 * The size can change while the volume is open.
1562 */
1563 uint64_t
1564 zvol_get_volume_size(void *minor_hdl)
1565 {
1566 zvol_state_t *zv = minor_hdl;
1567
1568 return (zv->zv_volsize);
1569 }
1570
1571 /*
1572 * Return the current WCE setting to an external caller.
1573 * The WCE setting can change while the volume is open.
1574 */
1575 int
1576 zvol_get_volume_wce(void *minor_hdl)
1577 {
1578 zvol_state_t *zv = minor_hdl;
1579
1580 return ((zv->zv_flags & ZVOL_WCE) ? 1 : 0);
1581 }
1582
1583 /*
1584 * Entry point for external callers to zvol_log_write
1585 */
1586 void
1587 zvol_log_write_minor(void *minor_hdl, dmu_tx_t *tx, offset_t off, ssize_t resid,
1588 boolean_t sync)
1589 {
1590 zvol_state_t *zv = minor_hdl;
1591
1592 zvol_log_write(zv, tx, off, resid, sync);
1593 }
1594 /*
1595 * END entry points to allow external callers access to the volume.
1596 */
1597
1598 /*
1599 * Log a DKIOCFREE/free-long-range to the ZIL with TX_TRUNCATE.
1600 */
1601 static void
1602 zvol_log_truncate(zvol_state_t *zv, dmu_tx_t *tx, uint64_t off, uint64_t len,
1603 boolean_t sync)
1604 {
1605 itx_t *itx;
1606 lr_truncate_t *lr;
1607 zilog_t *zilog = zv->zv_zilog;
1608
1609 if (zil_replaying(zilog, tx))
1610 return;
1611
1612 itx = zil_itx_create(TX_TRUNCATE, sizeof (*lr));
1613 lr = (lr_truncate_t *)&itx->itx_lr;
1614 lr->lr_foid = ZVOL_OBJ;
1615 lr->lr_offset = off;
1616 lr->lr_length = len;
1617
1618 itx->itx_sync = sync;
1619 zil_itx_assign(zilog, itx, tx);
1620 }
1621
1622 /*
1623 * Dirtbag ioctls to support mkfs(1M) for UFS filesystems. See dkio(7I).
1624 * Also a dirtbag dkio ioctl for unmap/free-block functionality.
1625 */
1626 /*ARGSUSED*/
1627 int
1628 zvol_ioctl(dev_t dev, int cmd, intptr_t arg, int flag, cred_t *cr, int *rvalp)
1629 {
1630 zvol_state_t *zv;
1631 struct dk_callback *dkc;
1632 int error = 0;
1633 rl_t *rl;
1634
1635 mutex_enter(&zfsdev_state_lock);
1636
1637 zv = zfsdev_get_soft_state(getminor(dev), ZSST_ZVOL);
1638
1639 if (zv == NULL) {
1640 mutex_exit(&zfsdev_state_lock);
1641 return (SET_ERROR(ENXIO));
1642 }
1643 ASSERT(zv->zv_total_opens > 0);
1644
1645 switch (cmd) {
1646
1647 case DKIOCINFO:
1648 {
1649 struct dk_cinfo dki;
1650
1651 bzero(&dki, sizeof (dki));
1652 (void) strcpy(dki.dki_cname, "zvol");
1653 (void) strcpy(dki.dki_dname, "zvol");
1654 dki.dki_ctype = DKC_UNKNOWN;
1655 dki.dki_unit = getminor(dev);
1656 dki.dki_maxtransfer =
1657 1 << (SPA_OLD_MAXBLOCKSHIFT - zv->zv_min_bs);
1658 mutex_exit(&zfsdev_state_lock);
1659 if (ddi_copyout(&dki, (void *)arg, sizeof (dki), flag))
1660 error = SET_ERROR(EFAULT);
1661 return (error);
1662 }
1663
1664 case DKIOCGMEDIAINFO:
1665 {
1666 struct dk_minfo dkm;
1667
1668 bzero(&dkm, sizeof (dkm));
1669 dkm.dki_lbsize = 1U << zv->zv_min_bs;
1670 dkm.dki_capacity = zv->zv_volsize >> zv->zv_min_bs;
1671 dkm.dki_media_type = DK_UNKNOWN;
1672 mutex_exit(&zfsdev_state_lock);
1673 if (ddi_copyout(&dkm, (void *)arg, sizeof (dkm), flag))
1674 error = SET_ERROR(EFAULT);
1675 return (error);
1676 }
1677
1678 case DKIOCGMEDIAINFOEXT:
1679 {
1680 struct dk_minfo_ext dkmext;
1681
1682 bzero(&dkmext, sizeof (dkmext));
1683 dkmext.dki_lbsize = 1U << zv->zv_min_bs;
1684 dkmext.dki_pbsize = zv->zv_volblocksize;
1685 dkmext.dki_capacity = zv->zv_volsize >> zv->zv_min_bs;
1686 dkmext.dki_media_type = DK_UNKNOWN;
1687 mutex_exit(&zfsdev_state_lock);
1688 if (ddi_copyout(&dkmext, (void *)arg, sizeof (dkmext), flag))
1689 error = SET_ERROR(EFAULT);
1690 return (error);
1691 }
1692
1693 case DKIOCGETEFI:
1694 {
1695 uint64_t vs = zv->zv_volsize;
1696 uint8_t bs = zv->zv_min_bs;
1697
1698 mutex_exit(&zfsdev_state_lock);
1699 error = zvol_getefi((void *)arg, flag, vs, bs);
1700 return (error);
1701 }
1702
1703 case DKIOCFLUSHWRITECACHE:
1704 dkc = (struct dk_callback *)arg;
1705 mutex_exit(&zfsdev_state_lock);
1706 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1707 if ((flag & FKIOCTL) && dkc != NULL && dkc->dkc_callback) {
1708 (*dkc->dkc_callback)(dkc->dkc_cookie, error);
1709 error = 0;
1710 }
1711 return (error);
1712
1713 case DKIOCGETWCE:
1714 {
1715 int wce = (zv->zv_flags & ZVOL_WCE) ? 1 : 0;
1716 if (ddi_copyout(&wce, (void *)arg, sizeof (int),
1717 flag))
1718 error = SET_ERROR(EFAULT);
1719 break;
1720 }
1721 case DKIOCSETWCE:
1722 {
1723 int wce;
1724 if (ddi_copyin((void *)arg, &wce, sizeof (int),
1725 flag)) {
1726 error = SET_ERROR(EFAULT);
1727 break;
1728 }
1729 if (wce) {
1730 zv->zv_flags |= ZVOL_WCE;
1731 mutex_exit(&zfsdev_state_lock);
1732 } else {
1733 zv->zv_flags &= ~ZVOL_WCE;
1734 mutex_exit(&zfsdev_state_lock);
1735 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1736 }
1737 return (0);
1738 }
1739
1740 case DKIOCGGEOM:
1741 case DKIOCGVTOC:
1742 /*
1743 * commands using these (like prtvtoc) expect ENOTSUP
1744 * since we're emulating an EFI label
1745 */
1746 error = SET_ERROR(ENOTSUP);
1747 break;
1748
1749 case DKIOCDUMPINIT:
1750 rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize,
1751 RL_WRITER);
1752 error = zvol_dumpify(zv);
1753 zfs_range_unlock(rl);
1754 break;
1755
1756 case DKIOCDUMPFINI:
1757 if (!(zv->zv_flags & ZVOL_DUMPIFIED))
1758 break;
1759 rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize,
1760 RL_WRITER);
1761 error = zvol_dump_fini(zv);
1762 zfs_range_unlock(rl);
1763 break;
1764
1765 case DKIOCFREE:
1766 {
1767 dkioc_free_t df;
1768 dmu_tx_t *tx;
1769
1770 if (!zvol_unmap_enabled)
1771 break;
1772
1773 if (ddi_copyin((void *)arg, &df, sizeof (df), flag)) {
1774 error = SET_ERROR(EFAULT);
1775 break;
1776 }
1777
1778 /*
1779 * Apply Postel's Law to length-checking. If they overshoot,
1780 * just blank out until the end, if there's a need to blank
1781 * out anything.
1782 */
1783 if (df.df_start >= zv->zv_volsize)
1784 break; /* No need to do anything... */
1785
1786 mutex_exit(&zfsdev_state_lock);
1787
1788 rl = zfs_range_lock(&zv->zv_znode, df.df_start, df.df_length,
1789 RL_WRITER);
1790 tx = dmu_tx_create(zv->zv_objset);
1791 dmu_tx_mark_netfree(tx);
1792 error = dmu_tx_assign(tx, TXG_WAIT);
1793 if (error != 0) {
1794 dmu_tx_abort(tx);
1795 } else {
1796 zvol_log_truncate(zv, tx, df.df_start,
1797 df.df_length, B_TRUE);
1798 dmu_tx_commit(tx);
1799 error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ,
1800 df.df_start, df.df_length);
1801 }
1802
1803 zfs_range_unlock(rl);
1804
1805 /*
1806 * If the write-cache is disabled, 'sync' property
1807 * is set to 'always', or if the caller is asking for
1808 * a synchronous free, commit this operation to the zil.
1809 * This will sync any previous uncommitted writes to the
1810 * zvol object.
1811 * Can be overridden by the zvol_unmap_sync_enabled tunable.
1812 */
1813 if ((error == 0) && zvol_unmap_sync_enabled &&
1814 (!(zv->zv_flags & ZVOL_WCE) ||
1815 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS) ||
1816 (df.df_flags & DF_WAIT_SYNC))) {
1817 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1818 }
1819
1820 return (error);
1821 }
1822
1823 default:
1824 error = SET_ERROR(ENOTTY);
1825 break;
1826
1827 }
1828 mutex_exit(&zfsdev_state_lock);
1829 return (error);
1830 }
1831
1832 int
1833 zvol_busy(void)
1834 {
1835 return (zvol_minors != 0);
1836 }
1837
1838 void
1839 zvol_init(void)
1840 {
1841 VERIFY(ddi_soft_state_init(&zfsdev_state, sizeof (zfs_soft_state_t),
1842 1) == 0);
1843 mutex_init(&zfsdev_state_lock, NULL, MUTEX_DEFAULT, NULL);
1844 }
1845
1846 void
1847 zvol_fini(void)
1848 {
1849 mutex_destroy(&zfsdev_state_lock);
1850 ddi_soft_state_fini(&zfsdev_state);
1851 }
1852
1853 /*ARGSUSED*/
1854 static int
1855 zfs_mvdev_dump_feature_check(void *arg, dmu_tx_t *tx)
1856 {
1857 spa_t *spa = dmu_tx_pool(tx)->dp_spa;
1858
1859 if (spa_feature_is_active(spa, SPA_FEATURE_MULTI_VDEV_CRASH_DUMP))
1860 return (1);
1861 return (0);
1862 }
1863
1864 /*ARGSUSED*/
1865 static void
1866 zfs_mvdev_dump_activate_feature_sync(void *arg, dmu_tx_t *tx)
1867 {
1868 spa_t *spa = dmu_tx_pool(tx)->dp_spa;
1869
1870 spa_feature_incr(spa, SPA_FEATURE_MULTI_VDEV_CRASH_DUMP, tx);
1871 }
1872
1873 static int
1874 zvol_dump_init(zvol_state_t *zv, boolean_t resize)
1875 {
1876 dmu_tx_t *tx;
1877 int error;
1878 objset_t *os = zv->zv_objset;
1879 spa_t *spa = dmu_objset_spa(os);
1880 vdev_t *vd = spa->spa_root_vdev;
1881 nvlist_t *nv = NULL;
1882 uint64_t version = spa_version(spa);
1883 uint64_t checksum, compress, refresrv, vbs, dedup;
1884
1885 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
1886 ASSERT(vd->vdev_ops == &vdev_root_ops);
1887
1888 error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, 0,
1889 DMU_OBJECT_END);
1890 if (error != 0)
1891 return (error);
1892 /* wait for dmu_free_long_range to actually free the blocks */
1893 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
1894
1895 /*
1896 * If the pool on which the dump device is being initialized has more
1897 * than one child vdev, check that the MULTI_VDEV_CRASH_DUMP feature is
1898 * enabled. If so, bump that feature's counter to indicate that the
1899 * feature is active. We also check the vdev type to handle the
1900 * following case:
1901 * # zpool create test raidz disk1 disk2 disk3
1902 * Now have spa_root_vdev->vdev_children == 1 (the raidz vdev),
1903 * the raidz vdev itself has 3 children.
1904 */
1905 if (vd->vdev_children > 1 || vd->vdev_ops == &vdev_raidz_ops) {
1906 if (!spa_feature_is_enabled(spa,
1907 SPA_FEATURE_MULTI_VDEV_CRASH_DUMP))
1908 return (SET_ERROR(ENOTSUP));
1909 (void) dsl_sync_task(spa_name(spa),
1910 zfs_mvdev_dump_feature_check,
1911 zfs_mvdev_dump_activate_feature_sync, NULL,
1912 2, ZFS_SPACE_CHECK_RESERVED);
1913 }
1914
1915 if (!resize) {
1916 error = dsl_prop_get_integer(zv->zv_name,
1917 zfs_prop_to_name(ZFS_PROP_COMPRESSION), &compress, NULL);
1918 if (error == 0) {
1919 error = dsl_prop_get_integer(zv->zv_name,
1920 zfs_prop_to_name(ZFS_PROP_CHECKSUM), &checksum,
1921 NULL);
1922 }
1923 if (error == 0) {
1924 error = dsl_prop_get_integer(zv->zv_name,
1925 zfs_prop_to_name(ZFS_PROP_REFRESERVATION),
1926 &refresrv, NULL);
1927 }
1928 if (error == 0) {
1929 error = dsl_prop_get_integer(zv->zv_name,
1930 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &vbs,
1931 NULL);
1932 }
1933 if (version >= SPA_VERSION_DEDUP && error == 0) {
1934 error = dsl_prop_get_integer(zv->zv_name,
1935 zfs_prop_to_name(ZFS_PROP_DEDUP), &dedup, NULL);
1936 }
1937 }
1938 if (error != 0)
1939 return (error);
1940
1941 tx = dmu_tx_create(os);
1942 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
1943 dmu_tx_hold_bonus(tx, ZVOL_OBJ);
1944 error = dmu_tx_assign(tx, TXG_WAIT);
1945 if (error != 0) {
1946 dmu_tx_abort(tx);
1947 return (error);
1948 }
1949
1950 /*
1951 * If we are resizing the dump device then we only need to
1952 * update the refreservation to match the newly updated
1953 * zvolsize. Otherwise, we save off the original state of the
1954 * zvol so that we can restore them if the zvol is ever undumpified.
1955 */
1956 if (resize) {
1957 error = zap_update(os, ZVOL_ZAP_OBJ,
1958 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1,
1959 &zv->zv_volsize, tx);
1960 } else {
1961 error = zap_update(os, ZVOL_ZAP_OBJ,
1962 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1,
1963 &compress, tx);
1964 if (error == 0) {
1965 error = zap_update(os, ZVOL_ZAP_OBJ,
1966 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1,
1967 &checksum, tx);
1968 }
1969 if (error == 0) {
1970 error = zap_update(os, ZVOL_ZAP_OBJ,
1971 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1,
1972 &refresrv, tx);
1973 }
1974 if (error == 0) {
1975 error = zap_update(os, ZVOL_ZAP_OBJ,
1976 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1,
1977 &vbs, tx);
1978 }
1979 if (error == 0) {
1980 error = dmu_object_set_blocksize(
1981 os, ZVOL_OBJ, SPA_OLD_MAXBLOCKSIZE, 0, tx);
1982 }
1983 if (version >= SPA_VERSION_DEDUP && error == 0) {
1984 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 (error == 0 && !resize) {
1998 /*
1999 * If MULTI_VDEV_CRASH_DUMP is active, use the NOPARITY checksum
2000 * function. Otherwise, use the old default -- OFF.
2001 */
2002 checksum = spa_feature_is_active(spa,
2003 SPA_FEATURE_MULTI_VDEV_CRASH_DUMP) ? ZIO_CHECKSUM_NOPARITY :
2004 ZIO_CHECKSUM_OFF;
2005
2006 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2007 VERIFY(nvlist_add_uint64(nv,
2008 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 0) == 0);
2009 VERIFY(nvlist_add_uint64(nv,
2010 zfs_prop_to_name(ZFS_PROP_COMPRESSION),
2011 ZIO_COMPRESS_OFF) == 0);
2012 VERIFY(nvlist_add_uint64(nv,
2013 zfs_prop_to_name(ZFS_PROP_CHECKSUM),
2014 checksum) == 0);
2015 if (version >= SPA_VERSION_DEDUP) {
2016 VERIFY(nvlist_add_uint64(nv,
2017 zfs_prop_to_name(ZFS_PROP_DEDUP),
2018 ZIO_CHECKSUM_OFF) == 0);
2019 }
2020
2021 error = zfs_set_prop_nvlist(zv->zv_name, ZPROP_SRC_LOCAL,
2022 nv, NULL);
2023 nvlist_free(nv);
2024 }
2025
2026 /* Allocate the space for the dump */
2027 if (error == 0)
2028 error = zvol_prealloc(zv);
2029 return (error);
2030 }
2031
2032 static int
2033 zvol_dumpify(zvol_state_t *zv)
2034 {
2035 int error = 0;
2036 uint64_t dumpsize = 0;
2037 dmu_tx_t *tx;
2038 objset_t *os = zv->zv_objset;
2039
2040 if (zv->zv_flags & ZVOL_RDONLY)
2041 return (SET_ERROR(EROFS));
2042
2043 if (zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE,
2044 8, 1, &dumpsize) != 0 || dumpsize != zv->zv_volsize) {
2045 boolean_t resize = (dumpsize > 0);
2046
2047 if ((error = zvol_dump_init(zv, resize)) != 0) {
2048 (void) zvol_dump_fini(zv);
2049 return (error);
2050 }
2051 }
2052
2053 /*
2054 * Build up our lba mapping.
2055 */
2056 error = zvol_get_lbas(zv);
2057 if (error) {
2058 (void) zvol_dump_fini(zv);
2059 return (error);
2060 }
2061
2062 tx = dmu_tx_create(os);
2063 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
2064 error = dmu_tx_assign(tx, TXG_WAIT);
2065 if (error) {
2066 dmu_tx_abort(tx);
2067 (void) zvol_dump_fini(zv);
2068 return (error);
2069 }
2070
2071 zv->zv_flags |= ZVOL_DUMPIFIED;
2072 error = zap_update(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, 8, 1,
2073 &zv->zv_volsize, tx);
2074 dmu_tx_commit(tx);
2075
2076 if (error) {
2077 (void) zvol_dump_fini(zv);
2078 return (error);
2079 }
2080
2081 txg_wait_synced(dmu_objset_pool(os), 0);
2082 return (0);
2083 }
2084
2085 static int
2086 zvol_dump_fini(zvol_state_t *zv)
2087 {
2088 dmu_tx_t *tx;
2089 objset_t *os = zv->zv_objset;
2090 nvlist_t *nv;
2091 int error = 0;
2092 uint64_t checksum, compress, refresrv, vbs, dedup;
2093 uint64_t version = spa_version(dmu_objset_spa(zv->zv_objset));
2094
2095 /*
2096 * Attempt to restore the zvol back to its pre-dumpified state.
2097 * This is a best-effort attempt as it's possible that not all
2098 * of these properties were initialized during the dumpify process
2099 * (i.e. error during zvol_dump_init).
2100 */
2101
2102 tx = dmu_tx_create(os);
2103 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
2104 error = dmu_tx_assign(tx, TXG_WAIT);
2105 if (error) {
2106 dmu_tx_abort(tx);
2107 return (error);
2108 }
2109 (void) zap_remove(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, tx);
2110 dmu_tx_commit(tx);
2111
2112 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2113 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1, &checksum);
2114 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2115 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1, &compress);
2116 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2117 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, &refresrv);
2118 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2119 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1, &vbs);
2120
2121 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2122 (void) nvlist_add_uint64(nv,
2123 zfs_prop_to_name(ZFS_PROP_CHECKSUM), checksum);
2124 (void) nvlist_add_uint64(nv,
2125 zfs_prop_to_name(ZFS_PROP_COMPRESSION), compress);
2126 (void) nvlist_add_uint64(nv,
2127 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), refresrv);
2128 if (version >= SPA_VERSION_DEDUP &&
2129 zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2130 zfs_prop_to_name(ZFS_PROP_DEDUP), 8, 1, &dedup) == 0) {
2131 (void) nvlist_add_uint64(nv,
2132 zfs_prop_to_name(ZFS_PROP_DEDUP), dedup);
2133 }
2134 (void) zfs_set_prop_nvlist(zv->zv_name, ZPROP_SRC_LOCAL,
2135 nv, NULL);
2136 nvlist_free(nv);
2137
2138 zvol_free_extents(zv);
2139 zv->zv_flags &= ~ZVOL_DUMPIFIED;
2140 (void) dmu_free_long_range(os, ZVOL_OBJ, 0, DMU_OBJECT_END);
2141 /* wait for dmu_free_long_range to actually free the blocks */
2142 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
2143 tx = dmu_tx_create(os);
2144 dmu_tx_hold_bonus(tx, ZVOL_OBJ);
2145 error = dmu_tx_assign(tx, TXG_WAIT);
2146 if (error) {
2147 dmu_tx_abort(tx);
2148 return (error);
2149 }
2150 if (dmu_object_set_blocksize(os, ZVOL_OBJ, vbs, 0, tx) == 0)
2151 zv->zv_volblocksize = vbs;
2152 dmu_tx_commit(tx);
2153
2154 return (0);
2155 }
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