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/zfs_events.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 extern int zfs_set_prop_nvlist(const char *, zprop_source_t,
152 nvlist_t *, nvlist_t *);
153 static int zvol_remove_zv(zvol_state_t *);
154 static int zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio);
155 static int zvol_dumpify(zvol_state_t *zv);
156 static int zvol_dump_fini(zvol_state_t *zv);
157 static int zvol_dump_init(zvol_state_t *zv, boolean_t resize);
158
159 static void
zvol_size_changed(zvol_state_t * zv,uint64_t volsize)160 zvol_size_changed(zvol_state_t *zv, uint64_t volsize)
161 {
162 dev_t dev = makedevice(ddi_driver_major(zfs_dip), zv->zv_minor);
163
164 zv->zv_volsize = volsize;
165 VERIFY(ddi_prop_update_int64(dev, zfs_dip,
166 "Size", volsize) == DDI_SUCCESS);
167 VERIFY(ddi_prop_update_int64(dev, zfs_dip,
168 "Nblocks", lbtodb(volsize)) == DDI_SUCCESS);
169
170 /* Notify specfs to invalidate the cached size */
171 spec_size_invalidate(dev, VBLK);
172 spec_size_invalidate(dev, VCHR);
173 }
174
175 int
zvol_check_volsize(uint64_t volsize,uint64_t blocksize)176 zvol_check_volsize(uint64_t volsize, uint64_t blocksize)
177 {
178 if (volsize == 0)
179 return (SET_ERROR(EINVAL));
180
181 if (volsize % blocksize != 0)
182 return (SET_ERROR(EINVAL));
183
184 #ifdef _ILP32
185 if (volsize - 1 > SPEC_MAXOFFSET_T)
186 return (SET_ERROR(EOVERFLOW));
187 #endif
188 return (0);
189 }
190
191 int
zvol_check_volblocksize(uint64_t volblocksize)192 zvol_check_volblocksize(uint64_t volblocksize)
193 {
194 if (volblocksize < SPA_MINBLOCKSIZE ||
195 volblocksize > SPA_OLD_MAXBLOCKSIZE ||
196 !ISP2(volblocksize))
197 return (SET_ERROR(EDOM));
198
199 return (0);
200 }
201
202 int
zvol_get_stats(objset_t * os,nvlist_t * nv)203 zvol_get_stats(objset_t *os, nvlist_t *nv)
204 {
205 int error;
206 dmu_object_info_t doi;
207 uint64_t val;
208
209 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &val);
210 if (error)
211 return (error);
212
213 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLSIZE, val);
214
215 error = dmu_object_info(os, ZVOL_OBJ, &doi);
216
217 if (error == 0) {
218 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLBLOCKSIZE,
219 doi.doi_data_block_size);
220 }
221
222 return (error);
223 }
224
225 static zvol_state_t *
zvol_minor_lookup(const char * name)226 zvol_minor_lookup(const char *name)
227 {
228 minor_t minor;
229 zvol_state_t *zv;
230
231 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
232
233 for (minor = 1; minor <= ZFSDEV_MAX_MINOR; minor++) {
234 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
235 if (zv == NULL)
236 continue;
237 if (strcmp(zv->zv_name, name) == 0)
238 return (zv);
239 }
240
241 return (NULL);
242 }
243
244 /* extent mapping arg */
245 struct maparg {
246 zvol_state_t *ma_zv;
247 uint64_t ma_blks;
248 };
249
250 /*ARGSUSED*/
251 static int
zvol_map_block(spa_t * spa,zilog_t * zilog,const blkptr_t * bp,const zbookmark_phys_t * zb,const dnode_phys_t * dnp,void * arg)252 zvol_map_block(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
253 const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
254 {
255 struct maparg *ma = arg;
256 zvol_extent_t *ze;
257 int bs = ma->ma_zv->zv_volblocksize;
258
259 if (bp == NULL || BP_IS_HOLE(bp) ||
260 zb->zb_object != ZVOL_OBJ || zb->zb_level != 0)
261 return (0);
262
263 VERIFY(!BP_IS_EMBEDDED(bp));
264
265 VERIFY3U(ma->ma_blks, ==, zb->zb_blkid);
266 ma->ma_blks++;
267
268 /* Abort immediately if we have encountered gang blocks */
269 if (BP_IS_GANG(bp))
270 return (SET_ERROR(EFRAGS));
271
272 /*
273 * See if the block is at the end of the previous extent.
274 */
275 ze = list_tail(&ma->ma_zv->zv_extents);
276 if (ze &&
277 DVA_GET_VDEV(BP_IDENTITY(bp)) == DVA_GET_VDEV(&ze->ze_dva) &&
278 DVA_GET_OFFSET(BP_IDENTITY(bp)) ==
279 DVA_GET_OFFSET(&ze->ze_dva) + ze->ze_nblks * bs) {
280 ze->ze_nblks++;
281 return (0);
282 }
283
284 dprintf_bp(bp, "%s", "next blkptr:");
285
286 /* start a new extent */
287 ze = kmem_zalloc(sizeof (zvol_extent_t), KM_SLEEP);
288 ze->ze_dva = bp->blk_dva[0]; /* structure assignment */
289 ze->ze_nblks = 1;
290 list_insert_tail(&ma->ma_zv->zv_extents, ze);
291 return (0);
292 }
293
294 static void
zvol_free_extents(zvol_state_t * zv)295 zvol_free_extents(zvol_state_t *zv)
296 {
297 zvol_extent_t *ze;
298
299 while (ze = list_head(&zv->zv_extents)) {
300 list_remove(&zv->zv_extents, ze);
301 kmem_free(ze, sizeof (zvol_extent_t));
302 }
303 }
304
305 static int
zvol_get_lbas(zvol_state_t * zv)306 zvol_get_lbas(zvol_state_t *zv)
307 {
308 objset_t *os = zv->zv_objset;
309 struct maparg ma;
310 int err;
311
312 ma.ma_zv = zv;
313 ma.ma_blks = 0;
314 zvol_free_extents(zv);
315
316 /* commit any in-flight changes before traversing the dataset */
317 txg_wait_synced(dmu_objset_pool(os), 0);
318 err = traverse_dataset(dmu_objset_ds(os), 0,
319 TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA, zvol_map_block, &ma);
320 if (err || ma.ma_blks != (zv->zv_volsize / zv->zv_volblocksize)) {
321 zvol_free_extents(zv);
322 return (err ? err : EIO);
323 }
324
325 return (0);
326 }
327
328 /* ARGSUSED */
329 void
zvol_create_cb(objset_t * os,void * arg,cred_t * cr,dmu_tx_t * tx)330 zvol_create_cb(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx)
331 {
332 zfs_creat_t *zct = arg;
333 nvlist_t *nvprops = zct->zct_props;
334 int error;
335 uint64_t volblocksize, volsize;
336
337 VERIFY(nvlist_lookup_uint64(nvprops,
338 zfs_prop_to_name(ZFS_PROP_VOLSIZE), &volsize) == 0);
339 if (nvlist_lookup_uint64(nvprops,
340 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &volblocksize) != 0)
341 volblocksize = zfs_prop_default_numeric(ZFS_PROP_VOLBLOCKSIZE);
342
343 /*
344 * These properties must be removed from the list so the generic
345 * property setting step won't apply to them.
346 */
347 VERIFY(nvlist_remove_all(nvprops,
348 zfs_prop_to_name(ZFS_PROP_VOLSIZE)) == 0);
349 (void) nvlist_remove_all(nvprops,
350 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE));
351
352 error = dmu_object_claim(os, ZVOL_OBJ, DMU_OT_ZVOL, volblocksize,
353 DMU_OT_NONE, 0, tx);
354 ASSERT(error == 0);
355
356 error = zap_create_claim(os, ZVOL_ZAP_OBJ, DMU_OT_ZVOL_PROP,
357 DMU_OT_NONE, 0, tx);
358 ASSERT(error == 0);
359
360 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize, tx);
361 ASSERT(error == 0);
362 }
363
364 /*
365 * Replay a TX_TRUNCATE ZIL transaction if asked. TX_TRUNCATE is how we
366 * implement DKIOCFREE/free-long-range.
367 */
368 static int
zvol_replay_truncate(zvol_state_t * zv,lr_truncate_t * lr,boolean_t byteswap)369 zvol_replay_truncate(zvol_state_t *zv, lr_truncate_t *lr, boolean_t byteswap)
370 {
371 uint64_t offset, length;
372
373 if (byteswap)
374 byteswap_uint64_array(lr, sizeof (*lr));
375
376 offset = lr->lr_offset;
377 length = lr->lr_length;
378
379 return (dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, offset, length));
380 }
381
382 /*
383 * Replay a TX_WRITE ZIL transaction that didn't get committed
384 * after a system failure
385 */
386 static int
zvol_replay_write(zvol_state_t * zv,lr_write_t * lr,boolean_t byteswap)387 zvol_replay_write(zvol_state_t *zv, lr_write_t *lr, boolean_t byteswap)
388 {
389 objset_t *os = zv->zv_objset;
390 char *data = (char *)(lr + 1); /* data follows lr_write_t */
391 uint64_t offset, length;
392 dmu_tx_t *tx;
393 int error;
394
395 if (byteswap)
396 byteswap_uint64_array(lr, sizeof (*lr));
397
398 offset = lr->lr_offset;
399 length = lr->lr_length;
400
401 /* If it's a dmu_sync() block, write the whole block */
402 if (lr->lr_common.lrc_reclen == sizeof (lr_write_t)) {
403 uint64_t blocksize = BP_GET_LSIZE(&lr->lr_blkptr);
404 if (length < blocksize) {
405 offset -= offset % blocksize;
406 length = blocksize;
407 }
408 }
409
410 tx = dmu_tx_create(os);
411 dmu_tx_hold_write(tx, ZVOL_OBJ, offset, length);
412 error = dmu_tx_assign(tx, TXG_WAIT);
413 if (error) {
414 dmu_tx_abort(tx);
415 } else {
416 dmu_write(os, ZVOL_OBJ, offset, length, data, tx);
417 dmu_tx_commit(tx);
418 }
419
420 return (error);
421 }
422
423 /* ARGSUSED */
424 static int
zvol_replay_err(zvol_state_t * zv,lr_t * lr,boolean_t byteswap)425 zvol_replay_err(zvol_state_t *zv, lr_t *lr, boolean_t byteswap)
426 {
427 return (SET_ERROR(ENOTSUP));
428 }
429
430 /*
431 * Callback vectors for replaying records.
432 * Only TX_WRITE and TX_TRUNCATE are needed for zvol.
433 */
434 zil_replay_func_t *zvol_replay_vector[TX_MAX_TYPE] = {
435 zvol_replay_err, /* 0 no such transaction type */
436 zvol_replay_err, /* TX_CREATE */
437 zvol_replay_err, /* TX_MKDIR */
438 zvol_replay_err, /* TX_MKXATTR */
439 zvol_replay_err, /* TX_SYMLINK */
440 zvol_replay_err, /* TX_REMOVE */
441 zvol_replay_err, /* TX_RMDIR */
442 zvol_replay_err, /* TX_LINK */
443 zvol_replay_err, /* TX_RENAME */
444 zvol_replay_write, /* TX_WRITE */
445 zvol_replay_truncate, /* TX_TRUNCATE */
446 zvol_replay_err, /* TX_SETATTR */
447 zvol_replay_err, /* TX_ACL */
448 zvol_replay_err, /* TX_CREATE_ACL */
449 zvol_replay_err, /* TX_CREATE_ATTR */
450 zvol_replay_err, /* TX_CREATE_ACL_ATTR */
451 zvol_replay_err, /* TX_MKDIR_ACL */
452 zvol_replay_err, /* TX_MKDIR_ATTR */
453 zvol_replay_err, /* TX_MKDIR_ACL_ATTR */
454 zvol_replay_err, /* TX_WRITE2 */
455 };
456
457 int
zvol_name2minor(const char * name,minor_t * minor)458 zvol_name2minor(const char *name, minor_t *minor)
459 {
460 zvol_state_t *zv;
461
462 mutex_enter(&zfsdev_state_lock);
463 zv = zvol_minor_lookup(name);
464 if (minor && zv)
465 *minor = zv->zv_minor;
466 mutex_exit(&zfsdev_state_lock);
467 return (zv ? 0 : -1);
468 }
469
470 /*
471 * Create a minor node (plus a whole lot more) for the specified volume.
472 */
473 int
zvol_create_minor(const char * name)474 zvol_create_minor(const char *name)
475 {
476 zfs_soft_state_t *zs;
477 zvol_state_t *zv;
478 objset_t *os;
479 dmu_object_info_t doi;
480 minor_t minor = 0;
481 char chrbuf[30], blkbuf[30];
482 int error;
483
484 mutex_enter(&zfsdev_state_lock);
485
486 if (zvol_minor_lookup(name) != NULL) {
487 mutex_exit(&zfsdev_state_lock);
488 return (SET_ERROR(EEXIST));
489 }
490
491 /* lie and say we're read-only */
492 error = dmu_objset_own(name, DMU_OST_ZVOL, B_TRUE, FTAG, &os);
493
494 if (error) {
495 mutex_exit(&zfsdev_state_lock);
496 return (error);
497 }
498
499 if ((minor = zfsdev_minor_alloc()) == 0) {
500 dmu_objset_disown(os, FTAG);
501 mutex_exit(&zfsdev_state_lock);
502 return (SET_ERROR(ENXIO));
503 }
504
505 if (ddi_soft_state_zalloc(zfsdev_state, minor) != DDI_SUCCESS) {
506 dmu_objset_disown(os, FTAG);
507 mutex_exit(&zfsdev_state_lock);
508 return (SET_ERROR(EAGAIN));
509 }
510 (void) ddi_prop_update_string(minor, zfs_dip, ZVOL_PROP_NAME,
511 (char *)name);
512
513 (void) snprintf(chrbuf, sizeof (chrbuf), "%u,raw", minor);
514
515 if (ddi_create_minor_node(zfs_dip, chrbuf, S_IFCHR,
516 minor, DDI_PSEUDO, 0) == DDI_FAILURE) {
517 ddi_soft_state_free(zfsdev_state, minor);
518 dmu_objset_disown(os, FTAG);
519 mutex_exit(&zfsdev_state_lock);
520 return (SET_ERROR(EAGAIN));
521 }
522
523 (void) snprintf(blkbuf, sizeof (blkbuf), "%u", minor);
524
525 if (ddi_create_minor_node(zfs_dip, blkbuf, S_IFBLK,
526 minor, DDI_PSEUDO, 0) == DDI_FAILURE) {
527 ddi_remove_minor_node(zfs_dip, chrbuf);
528 ddi_soft_state_free(zfsdev_state, minor);
529 dmu_objset_disown(os, FTAG);
530 mutex_exit(&zfsdev_state_lock);
531 return (SET_ERROR(EAGAIN));
532 }
533
534 zs = ddi_get_soft_state(zfsdev_state, minor);
535 zs->zss_type = ZSST_ZVOL;
536 zv = zs->zss_data = kmem_zalloc(sizeof (zvol_state_t), KM_SLEEP);
537 (void) strlcpy(zv->zv_name, name, MAXPATHLEN);
538 zv->zv_min_bs = DEV_BSHIFT;
539 zv->zv_minor = minor;
540 zv->zv_objset = os;
541 if (dmu_objset_is_snapshot(os) || !spa_writeable(dmu_objset_spa(os)))
542 zv->zv_flags |= ZVOL_RDONLY;
543 mutex_init(&zv->zv_znode.z_range_lock, NULL, MUTEX_DEFAULT, NULL);
544 avl_create(&zv->zv_znode.z_range_avl, zfs_range_compare,
545 sizeof (rl_t), offsetof(rl_t, r_node));
546 list_create(&zv->zv_extents, sizeof (zvol_extent_t),
547 offsetof(zvol_extent_t, ze_node));
548 /* get and cache the blocksize */
549 error = dmu_object_info(os, ZVOL_OBJ, &doi);
550 ASSERT(error == 0);
551 zv->zv_volblocksize = doi.doi_data_block_size;
552
553 if (spa_writeable(dmu_objset_spa(os))) {
554 if (zil_replay_disable)
555 zil_destroy(dmu_objset_zil(os), B_FALSE);
556 else
557 zil_replay(os, zv, zvol_replay_vector);
558 }
559 dmu_objset_disown(os, FTAG);
560 zv->zv_objset = NULL;
561
562 zvol_minors++;
563
564 mutex_exit(&zfsdev_state_lock);
565
566 return (0);
567 }
568
569 /*
570 * Remove minor node for the specified volume.
571 */
572 static int
zvol_remove_zv(zvol_state_t * zv)573 zvol_remove_zv(zvol_state_t *zv)
574 {
575 char nmbuf[20];
576 minor_t minor = zv->zv_minor;
577
578 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
579 if (zv->zv_total_opens != 0)
580 return (SET_ERROR(EBUSY));
581
582 (void) snprintf(nmbuf, sizeof (nmbuf), "%u,raw", minor);
583 ddi_remove_minor_node(zfs_dip, nmbuf);
584
585 (void) snprintf(nmbuf, sizeof (nmbuf), "%u", minor);
586 ddi_remove_minor_node(zfs_dip, nmbuf);
587
588 avl_destroy(&zv->zv_znode.z_range_avl);
589 mutex_destroy(&zv->zv_znode.z_range_lock);
590
591 kmem_free(zv, sizeof (zvol_state_t));
592
593 ddi_soft_state_free(zfsdev_state, minor);
594
595 zvol_minors--;
596 return (0);
597 }
598
599 int
zvol_remove_minor(const char * name)600 zvol_remove_minor(const char *name)
601 {
602 zvol_state_t *zv;
603 int rc;
604
605 mutex_enter(&zfsdev_state_lock);
606 if ((zv = zvol_minor_lookup(name)) == NULL) {
607 mutex_exit(&zfsdev_state_lock);
608 return (SET_ERROR(ENXIO));
609 }
610 rc = zvol_remove_zv(zv);
611 mutex_exit(&zfsdev_state_lock);
612 return (rc);
613 }
614
615 int
zvol_first_open(zvol_state_t * zv)616 zvol_first_open(zvol_state_t *zv)
617 {
618 objset_t *os;
619 uint64_t volsize;
620 int error;
621 uint64_t readonly;
622
623 /* lie and say we're read-only */
624 error = dmu_objset_own(zv->zv_name, DMU_OST_ZVOL, B_TRUE,
625 zvol_tag, &os);
626 if (error)
627 return (error);
628
629 zv->zv_objset = os;
630 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize);
631 if (error) {
632 ASSERT(error == 0);
633 dmu_objset_disown(os, zvol_tag);
634 return (error);
635 }
636
637 error = dmu_bonus_hold(os, ZVOL_OBJ, zvol_tag, &zv->zv_dbuf);
638 if (error) {
639 dmu_objset_disown(os, zvol_tag);
640 return (error);
641 }
642
643 zvol_size_changed(zv, volsize);
644 zv->zv_zilog = zil_open(os, zvol_get_data);
645
646 VERIFY(dsl_prop_get_integer(zv->zv_name, "readonly", &readonly,
647 NULL) == 0);
648 if (readonly || dmu_objset_is_snapshot(os) ||
649 !spa_writeable(dmu_objset_spa(os)))
650 zv->zv_flags |= ZVOL_RDONLY;
651 else
652 zv->zv_flags &= ~ZVOL_RDONLY;
653 return (error);
654 }
655
656 void
zvol_last_close(zvol_state_t * zv)657 zvol_last_close(zvol_state_t *zv)
658 {
659 zil_close(zv->zv_zilog);
660 zv->zv_zilog = NULL;
661
662 dmu_buf_rele(zv->zv_dbuf, zvol_tag);
663 zv->zv_dbuf = NULL;
664
665 /*
666 * Evict cached data
667 */
668 if (dsl_dataset_is_dirty(dmu_objset_ds(zv->zv_objset)) &&
669 !(zv->zv_flags & ZVOL_RDONLY))
670 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
671 dmu_objset_evict_dbufs(zv->zv_objset);
672
673 dmu_objset_disown(zv->zv_objset, zvol_tag);
674 zv->zv_objset = NULL;
675 }
676
677 int
zvol_prealloc(zvol_state_t * zv)678 zvol_prealloc(zvol_state_t *zv)
679 {
680 objset_t *os = zv->zv_objset;
681 dmu_tx_t *tx;
682 uint64_t refd, avail, usedobjs, availobjs;
683 uint64_t resid = zv->zv_volsize;
684 uint64_t off = 0;
685
686 /* Check the space usage before attempting to allocate the space */
687 dmu_objset_space(os, &refd, &avail, &usedobjs, &availobjs);
688 if (avail < zv->zv_volsize)
689 return (SET_ERROR(ENOSPC));
690
691 /* Free old extents if they exist */
692 zvol_free_extents(zv);
693
694 while (resid != 0) {
695 int error;
696 uint64_t bytes = MIN(resid, SPA_OLD_MAXBLOCKSIZE);
697
698 tx = dmu_tx_create(os);
699 dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes);
700 error = dmu_tx_assign(tx, TXG_WAIT);
701 if (error) {
702 dmu_tx_abort(tx);
703 (void) dmu_free_long_range(os, ZVOL_OBJ, 0, off);
704 return (error);
705 }
706 dmu_prealloc(os, ZVOL_OBJ, off, bytes, tx);
707 dmu_tx_commit(tx);
708 off += bytes;
709 resid -= bytes;
710 }
711 txg_wait_synced(dmu_objset_pool(os), 0);
712
713 return (0);
714 }
715
716 static int
zvol_update_volsize(objset_t * os,uint64_t volsize)717 zvol_update_volsize(objset_t *os, uint64_t volsize)
718 {
719 dmu_tx_t *tx;
720 int error;
721
722 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
723
724 tx = dmu_tx_create(os);
725 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
726 dmu_tx_mark_netfree(tx);
727 error = dmu_tx_assign(tx, TXG_WAIT);
728 if (error) {
729 dmu_tx_abort(tx);
730 return (error);
731 }
732
733 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1,
734 &volsize, tx);
735 dmu_tx_commit(tx);
736
737 if (error == 0)
738 error = dmu_free_long_range(os,
739 ZVOL_OBJ, volsize, DMU_OBJECT_END);
740 return (error);
741 }
742
743 void
zvol_remove_minors(const char * name)744 zvol_remove_minors(const char *name)
745 {
746 zvol_state_t *zv;
747 char *namebuf;
748 minor_t minor;
749
750 namebuf = kmem_zalloc(strlen(name) + 2, KM_SLEEP);
751 (void) strncpy(namebuf, name, strlen(name));
752 (void) strcat(namebuf, "/");
753 mutex_enter(&zfsdev_state_lock);
754 for (minor = 1; minor <= ZFSDEV_MAX_MINOR; minor++) {
755
756 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
757 if (zv == NULL)
758 continue;
759 if (strncmp(namebuf, zv->zv_name, strlen(namebuf)) == 0)
760 (void) zvol_remove_zv(zv);
761 }
762 kmem_free(namebuf, strlen(name) + 2);
763
764 mutex_exit(&zfsdev_state_lock);
765 }
766
767 static int
zvol_update_live_volsize(zvol_state_t * zv,uint64_t volsize)768 zvol_update_live_volsize(zvol_state_t *zv, uint64_t volsize)
769 {
770 uint64_t old_volsize = 0ULL;
771 int error = 0;
772
773 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
774
775 /*
776 * Reinitialize the dump area to the new size. If we
777 * failed to resize the dump area then restore it back to
778 * its original size. We must set the new volsize prior
779 * to calling dumpvp_resize() to ensure that the devices'
780 * size(9P) is not visible by the dump subsystem.
781 */
782 old_volsize = zv->zv_volsize;
783 zvol_size_changed(zv, volsize);
784
785 if (zv->zv_flags & ZVOL_DUMPIFIED) {
786 if ((error = zvol_dumpify(zv)) != 0 ||
787 (error = dumpvp_resize()) != 0) {
788 int dumpify_error;
789
790 (void) zvol_update_volsize(zv->zv_objset, old_volsize);
791 zvol_size_changed(zv, old_volsize);
792 dumpify_error = zvol_dumpify(zv);
793 error = dumpify_error ? dumpify_error : error;
794 }
795 }
796
797 /*
798 * Generate a LUN expansion event.
799 */
800 if (error == 0) {
801 sysevent_id_t eid;
802 nvlist_t *attr;
803 char *physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
804
805 (void) snprintf(physpath, MAXPATHLEN, "%s%u", ZVOL_PSEUDO_DEV,
806 zv->zv_minor);
807
808 VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0);
809 VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0);
810
811 (void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS,
812 ESC_DEV_DLE, attr, &eid, DDI_SLEEP);
813
814 nvlist_free(attr);
815 kmem_free(physpath, MAXPATHLEN);
816 }
817 return (error);
818 }
819
820 int
zvol_set_volsize(const char * name,uint64_t volsize)821 zvol_set_volsize(const char *name, uint64_t volsize)
822 {
823 zvol_state_t *zv = NULL;
824 objset_t *os;
825 int error;
826 dmu_object_info_t doi;
827 uint64_t readonly;
828 boolean_t owned = B_FALSE;
829
830 error = dsl_prop_get_integer(name,
831 zfs_prop_to_name(ZFS_PROP_READONLY), &readonly, NULL);
832 if (error != 0)
833 return (error);
834 if (readonly)
835 return (SET_ERROR(EROFS));
836
837 mutex_enter(&zfsdev_state_lock);
838 zv = zvol_minor_lookup(name);
839
840 if (zv == NULL || zv->zv_objset == NULL) {
841 if ((error = dmu_objset_own(name, DMU_OST_ZVOL, B_FALSE,
842 FTAG, &os)) != 0) {
843 mutex_exit(&zfsdev_state_lock);
844 return (error);
845 }
846 owned = B_TRUE;
847 if (zv != NULL)
848 zv->zv_objset = os;
849 } else {
850 os = zv->zv_objset;
851 }
852
853 if ((error = dmu_object_info(os, ZVOL_OBJ, &doi)) != 0 ||
854 (error = zvol_check_volsize(volsize, doi.doi_data_block_size)) != 0)
855 goto out;
856
857 error = zvol_update_volsize(os, volsize);
858
859 if (error == 0 && zv != NULL)
860 error = zvol_update_live_volsize(zv, volsize);
861 out:
862 if (owned) {
863 dmu_objset_disown(os, FTAG);
864 if (zv != NULL)
865 zv->zv_objset = NULL;
866 }
867 mutex_exit(&zfsdev_state_lock);
868 return (error);
869 }
870
871 /*ARGSUSED*/
872 int
zvol_open(dev_t * devp,int flag,int otyp,cred_t * cr)873 zvol_open(dev_t *devp, int flag, int otyp, cred_t *cr)
874 {
875 zvol_state_t *zv;
876 int err = 0;
877
878 mutex_enter(&zfsdev_state_lock);
879
880 zv = zfsdev_get_soft_state(getminor(*devp), ZSST_ZVOL);
881 if (zv == NULL) {
882 mutex_exit(&zfsdev_state_lock);
883 return (SET_ERROR(ENXIO));
884 }
885
886 if (zv->zv_total_opens == 0)
887 err = zvol_first_open(zv);
888 if (err) {
889 mutex_exit(&zfsdev_state_lock);
890 return (err);
891 }
892 if ((flag & FWRITE) && (zv->zv_flags & ZVOL_RDONLY)) {
893 err = SET_ERROR(EROFS);
894 goto out;
895 }
896 if (zv->zv_flags & ZVOL_EXCL) {
897 err = SET_ERROR(EBUSY);
898 goto out;
899 }
900 if (flag & FEXCL) {
901 if (zv->zv_total_opens != 0) {
902 err = SET_ERROR(EBUSY);
903 goto out;
904 }
905 zv->zv_flags |= ZVOL_EXCL;
906 }
907
908 if (zv->zv_open_count[otyp] == 0 || otyp == OTYP_LYR) {
909 zv->zv_open_count[otyp]++;
910 zv->zv_total_opens++;
911 }
912 mutex_exit(&zfsdev_state_lock);
913
914 return (err);
915 out:
916 if (zv->zv_total_opens == 0)
917 zvol_last_close(zv);
918 mutex_exit(&zfsdev_state_lock);
919 return (err);
920 }
921
922 /*ARGSUSED*/
923 int
zvol_close(dev_t dev,int flag,int otyp,cred_t * cr)924 zvol_close(dev_t dev, int flag, int otyp, cred_t *cr)
925 {
926 minor_t minor = getminor(dev);
927 zvol_state_t *zv;
928 int error = 0;
929
930 mutex_enter(&zfsdev_state_lock);
931
932 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
933 if (zv == NULL) {
934 mutex_exit(&zfsdev_state_lock);
935 return (SET_ERROR(ENXIO));
936 }
937
938 if (zv->zv_flags & ZVOL_EXCL) {
939 ASSERT(zv->zv_total_opens == 1);
940 zv->zv_flags &= ~ZVOL_EXCL;
941 }
942
943 /*
944 * If the open count is zero, this is a spurious close.
945 * That indicates a bug in the kernel / DDI framework.
946 */
947 ASSERT(zv->zv_open_count[otyp] != 0);
948 ASSERT(zv->zv_total_opens != 0);
949
950 /*
951 * You may get multiple opens, but only one close.
952 */
953 zv->zv_open_count[otyp]--;
954 zv->zv_total_opens--;
955
956 if (zv->zv_total_opens == 0)
957 zvol_last_close(zv);
958
959 mutex_exit(&zfsdev_state_lock);
960 return (error);
961 }
962
963 static void
zvol_get_done(zgd_t * zgd,int error)964 zvol_get_done(zgd_t *zgd, int error)
965 {
966 if (zgd->zgd_db)
967 dmu_buf_rele(zgd->zgd_db, zgd);
968
969 zfs_range_unlock(zgd->zgd_rl);
970
971 if (error == 0 && zgd->zgd_bp)
972 zil_add_block(zgd->zgd_zilog, zgd->zgd_bp);
973
974 kmem_free(zgd, sizeof (zgd_t));
975 }
976
977 /*
978 * Get data to generate a TX_WRITE intent log record.
979 */
980 static int
zvol_get_data(void * arg,lr_write_t * lr,char * buf,zio_t * zio)981 zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
982 {
983 zvol_state_t *zv = arg;
984 objset_t *os = zv->zv_objset;
985 uint64_t object = ZVOL_OBJ;
986 uint64_t offset = lr->lr_offset;
987 uint64_t size = lr->lr_length; /* length of user data */
988 blkptr_t *bp = &lr->lr_blkptr;
989 dmu_buf_t *db;
990 zgd_t *zgd;
991 int error;
992
993 ASSERT(zio != NULL);
994 ASSERT(size != 0);
995
996 zgd = kmem_zalloc(sizeof (zgd_t), KM_SLEEP);
997 zgd->zgd_zilog = zv->zv_zilog;
998 zgd->zgd_rl = zfs_range_lock(&zv->zv_znode, offset, size, RL_READER);
999
1000 /*
1001 * Write records come in two flavors: immediate and indirect.
1002 * For small writes it's cheaper to store the data with the
1003 * log record (immediate); for large writes it's cheaper to
1004 * sync the data and get a pointer to it (indirect) so that
1005 * we don't have to write the data twice.
1006 */
1007 if (buf != NULL) { /* immediate write */
1008 error = dmu_read(os, object, offset, size, buf,
1009 DMU_READ_NO_PREFETCH);
1010 } else {
1011 size = zv->zv_volblocksize;
1012 offset = P2ALIGN(offset, size);
1013 error = dmu_buf_hold(os, object, offset, zgd, &db,
1014 DMU_READ_NO_PREFETCH);
1015 if (error == 0) {
1016 blkptr_t *obp = dmu_buf_get_blkptr(db);
1017 if (obp) {
1018 ASSERT(BP_IS_HOLE(bp));
1019 *bp = *obp;
1020 }
1021
1022 zgd->zgd_db = db;
1023 zgd->zgd_bp = bp;
1024
1025 ASSERT(db->db_offset == offset);
1026 ASSERT(db->db_size == size);
1027
1028 error = dmu_sync(zio, lr->lr_common.lrc_txg,
1029 zvol_get_done, zgd);
1030
1031 if (error == 0)
1032 return (0);
1033 }
1034 }
1035
1036 zvol_get_done(zgd, error);
1037
1038 return (error);
1039 }
1040
1041 /*
1042 * zvol_log_write() handles synchronous writes using TX_WRITE ZIL transactions.
1043 *
1044 * We store data in the log buffers if it's small enough.
1045 * Otherwise we will later flush the data out via dmu_sync().
1046 */
1047 ssize_t zvol_immediate_write_sz = 32768;
1048
1049 static void
zvol_log_write(zvol_state_t * zv,dmu_tx_t * tx,offset_t off,ssize_t resid,boolean_t sync)1050 zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, offset_t off, ssize_t resid,
1051 boolean_t sync)
1052 {
1053 uint32_t blocksize = zv->zv_volblocksize;
1054 zilog_t *zilog = zv->zv_zilog;
1055 boolean_t slogging;
1056 ssize_t immediate_write_sz;
1057
1058 if (zil_replaying(zilog, tx))
1059 return;
1060
1061 immediate_write_sz = (zilog->zl_logbias == ZFS_LOGBIAS_THROUGHPUT)
1062 ? 0 : zvol_immediate_write_sz;
1063
1064 slogging = spa_has_slogs(zilog->zl_spa) &&
1065 (zilog->zl_logbias == ZFS_LOGBIAS_LATENCY);
1066
1067 while (resid) {
1068 itx_t *itx;
1069 lr_write_t *lr;
1070 ssize_t len;
1071 itx_wr_state_t write_state;
1072
1073 /*
1074 * Unlike zfs_log_write() we can be called with
1075 * upto DMU_MAX_ACCESS/2 (5MB) writes.
1076 */
1077 if (blocksize > immediate_write_sz && !slogging &&
1078 resid >= blocksize && off % blocksize == 0) {
1079 write_state = WR_INDIRECT; /* uses dmu_sync */
1080 len = blocksize;
1081 } else if (sync) {
1082 write_state = WR_COPIED;
1083 len = MIN(ZIL_MAX_LOG_DATA, resid);
1084 } else {
1085 write_state = WR_NEED_COPY;
1086 len = MIN(ZIL_MAX_LOG_DATA, resid);
1087 }
1088
1089 itx = zil_itx_create(TX_WRITE, sizeof (*lr) +
1090 (write_state == WR_COPIED ? len : 0));
1091 lr = (lr_write_t *)&itx->itx_lr;
1092 if (write_state == WR_COPIED && dmu_read(zv->zv_objset,
1093 ZVOL_OBJ, off, len, lr + 1, DMU_READ_NO_PREFETCH) != 0) {
1094 zil_itx_destroy(itx);
1095 itx = zil_itx_create(TX_WRITE, sizeof (*lr));
1096 lr = (lr_write_t *)&itx->itx_lr;
1097 write_state = WR_NEED_COPY;
1098 }
1099
1100 itx->itx_wr_state = write_state;
1101 if (write_state == WR_NEED_COPY)
1102 itx->itx_sod += len;
1103 lr->lr_foid = ZVOL_OBJ;
1104 lr->lr_offset = off;
1105 lr->lr_length = len;
1106 lr->lr_blkoff = 0;
1107 BP_ZERO(&lr->lr_blkptr);
1108
1109 itx->itx_private = zv;
1110 itx->itx_sync = sync;
1111
1112 zil_itx_assign(zilog, itx, tx);
1113
1114 rw_enter(&rz_zev_rwlock, RW_READER);
1115 if (rz_zev_callbacks && rz_zev_callbacks->rz_zev_zvol_write)
1116 rz_zev_callbacks->rz_zev_zvol_write(zv->zv_name,
1117 zv->zv_objset, tx, off, len);
1118 rw_exit(&rz_zev_rwlock);
1119
1120 off += len;
1121 resid -= len;
1122 }
1123 }
1124
1125 static int
zvol_dumpio_vdev(vdev_t * vd,void * addr,uint64_t offset,uint64_t origoffset,uint64_t size,boolean_t doread,boolean_t isdump)1126 zvol_dumpio_vdev(vdev_t *vd, void *addr, uint64_t offset, uint64_t origoffset,
1127 uint64_t size, boolean_t doread, boolean_t isdump)
1128 {
1129 vdev_disk_t *dvd;
1130 int c;
1131 int numerrors = 0;
1132
1133 if (vd->vdev_ops == &vdev_mirror_ops ||
1134 vd->vdev_ops == &vdev_replacing_ops ||
1135 vd->vdev_ops == &vdev_spare_ops) {
1136 for (c = 0; c < vd->vdev_children; c++) {
1137 int err = zvol_dumpio_vdev(vd->vdev_child[c],
1138 addr, offset, origoffset, size, doread, isdump);
1139 if (err != 0) {
1140 numerrors++;
1141 } else if (doread) {
1142 break;
1143 }
1144 }
1145 }
1146
1147 if (!vd->vdev_ops->vdev_op_leaf && vd->vdev_ops != &vdev_raidz_ops)
1148 return (numerrors < vd->vdev_children ? 0 : EIO);
1149
1150 if (doread && !vdev_readable(vd))
1151 return (SET_ERROR(EIO));
1152 else if (!doread && !vdev_writeable(vd))
1153 return (SET_ERROR(EIO));
1154
1155 if (vd->vdev_ops == &vdev_raidz_ops) {
1156 return (vdev_raidz_physio(vd,
1157 addr, size, offset, origoffset, doread, isdump));
1158 }
1159
1160 offset += VDEV_LABEL_START_SIZE;
1161
1162 if (ddi_in_panic() || isdump) {
1163 ASSERT(!doread);
1164 if (doread)
1165 return (SET_ERROR(EIO));
1166 dvd = vd->vdev_tsd;
1167 ASSERT3P(dvd, !=, NULL);
1168 return (ldi_dump(dvd->vd_lh, addr, lbtodb(offset),
1169 lbtodb(size)));
1170 } else {
1171 dvd = vd->vdev_tsd;
1172 ASSERT3P(dvd, !=, NULL);
1173 return (vdev_disk_ldi_physio(dvd->vd_lh, addr, size,
1174 offset, doread ? B_READ : B_WRITE));
1175 }
1176 }
1177
1178 static int
zvol_dumpio(zvol_state_t * zv,void * addr,uint64_t offset,uint64_t size,boolean_t doread,boolean_t isdump)1179 zvol_dumpio(zvol_state_t *zv, void *addr, uint64_t offset, uint64_t size,
1180 boolean_t doread, boolean_t isdump)
1181 {
1182 vdev_t *vd;
1183 int error;
1184 zvol_extent_t *ze;
1185 spa_t *spa = dmu_objset_spa(zv->zv_objset);
1186
1187 /* Must be sector aligned, and not stradle a block boundary. */
1188 if (P2PHASE(offset, DEV_BSIZE) || P2PHASE(size, DEV_BSIZE) ||
1189 P2BOUNDARY(offset, size, zv->zv_volblocksize)) {
1190 return (SET_ERROR(EINVAL));
1191 }
1192 ASSERT(size <= zv->zv_volblocksize);
1193
1194 /* Locate the extent this belongs to */
1195 ze = list_head(&zv->zv_extents);
1196 while (offset >= ze->ze_nblks * zv->zv_volblocksize) {
1197 offset -= ze->ze_nblks * zv->zv_volblocksize;
1198 ze = list_next(&zv->zv_extents, ze);
1199 }
1200
1201 if (ze == NULL)
1202 return (SET_ERROR(EINVAL));
1203
1204 if (!ddi_in_panic())
1205 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
1206
1207 vd = vdev_lookup_top(spa, DVA_GET_VDEV(&ze->ze_dva));
1208 offset += DVA_GET_OFFSET(&ze->ze_dva);
1209 error = zvol_dumpio_vdev(vd, addr, offset, DVA_GET_OFFSET(&ze->ze_dva),
1210 size, doread, isdump);
1211
1212 if (!ddi_in_panic())
1213 spa_config_exit(spa, SCL_STATE, FTAG);
1214
1215 return (error);
1216 }
1217
1218 int
zvol_strategy(buf_t * bp)1219 zvol_strategy(buf_t *bp)
1220 {
1221 zfs_soft_state_t *zs = NULL;
1222 zvol_state_t *zv;
1223 uint64_t off, volsize;
1224 size_t resid;
1225 char *addr;
1226 objset_t *os;
1227 rl_t *rl;
1228 int error = 0;
1229 boolean_t doread = bp->b_flags & B_READ;
1230 boolean_t is_dumpified;
1231 boolean_t sync;
1232
1233 if (getminor(bp->b_edev) == 0) {
1234 error = SET_ERROR(EINVAL);
1235 } else {
1236 zs = ddi_get_soft_state(zfsdev_state, getminor(bp->b_edev));
1237 if (zs == NULL)
1238 error = SET_ERROR(ENXIO);
1239 else if (zs->zss_type != ZSST_ZVOL)
1240 error = SET_ERROR(EINVAL);
1241 }
1242
1243 if (error) {
1244 bioerror(bp, error);
1245 biodone(bp);
1246 return (0);
1247 }
1248
1249 zv = zs->zss_data;
1250
1251 if (!(bp->b_flags & B_READ) && (zv->zv_flags & ZVOL_RDONLY)) {
1252 bioerror(bp, EROFS);
1253 biodone(bp);
1254 return (0);
1255 }
1256
1257 off = ldbtob(bp->b_blkno);
1258 volsize = zv->zv_volsize;
1259
1260 os = zv->zv_objset;
1261 ASSERT(os != NULL);
1262
1263 bp_mapin(bp);
1264 addr = bp->b_un.b_addr;
1265 resid = bp->b_bcount;
1266
1267 if (resid > 0 && (off < 0 || off >= volsize)) {
1268 bioerror(bp, EIO);
1269 biodone(bp);
1270 return (0);
1271 }
1272
1273 is_dumpified = zv->zv_flags & ZVOL_DUMPIFIED;
1274 sync = ((!(bp->b_flags & B_ASYNC) &&
1275 !(zv->zv_flags & ZVOL_WCE)) ||
1276 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS)) &&
1277 !doread && !is_dumpified;
1278
1279 /*
1280 * There must be no buffer changes when doing a dmu_sync() because
1281 * we can't change the data whilst calculating the checksum.
1282 */
1283 rl = zfs_range_lock(&zv->zv_znode, off, resid,
1284 doread ? RL_READER : RL_WRITER);
1285
1286 while (resid != 0 && off < volsize) {
1287 size_t size = MIN(resid, zvol_maxphys);
1288 if (is_dumpified) {
1289 size = MIN(size, P2END(off, zv->zv_volblocksize) - off);
1290 error = zvol_dumpio(zv, addr, off, size,
1291 doread, B_FALSE);
1292 } else if (doread) {
1293 error = dmu_read(os, ZVOL_OBJ, off, size, addr,
1294 DMU_READ_PREFETCH);
1295 } else {
1296 dmu_tx_t *tx = dmu_tx_create(os);
1297 dmu_tx_hold_write(tx, ZVOL_OBJ, off, size);
1298 error = dmu_tx_assign(tx, TXG_WAIT);
1299 if (error) {
1300 dmu_tx_abort(tx);
1301 } else {
1302 dmu_write(os, ZVOL_OBJ, off, size, addr, tx);
1303 zvol_log_write(zv, tx, off, size, sync);
1304 dmu_tx_commit(tx);
1305 }
1306 }
1307 if (error) {
1308 /* convert checksum errors into IO errors */
1309 if (error == ECKSUM)
1310 error = SET_ERROR(EIO);
1311 break;
1312 }
1313 off += size;
1314 addr += size;
1315 resid -= size;
1316 }
1317 zfs_range_unlock(rl);
1318
1319 if ((bp->b_resid = resid) == bp->b_bcount)
1320 bioerror(bp, off > volsize ? EINVAL : error);
1321
1322 if (sync)
1323 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1324 biodone(bp);
1325
1326 return (0);
1327 }
1328
1329 /*
1330 * Set the buffer count to the zvol maximum transfer.
1331 * Using our own routine instead of the default minphys()
1332 * means that for larger writes we write bigger buffers on X86
1333 * (128K instead of 56K) and flush the disk write cache less often
1334 * (every zvol_maxphys - currently 1MB) instead of minphys (currently
1335 * 56K on X86 and 128K on sparc).
1336 */
1337 void
zvol_minphys(struct buf * bp)1338 zvol_minphys(struct buf *bp)
1339 {
1340 if (bp->b_bcount > zvol_maxphys)
1341 bp->b_bcount = zvol_maxphys;
1342 }
1343
1344 int
zvol_dump(dev_t dev,caddr_t addr,daddr_t blkno,int nblocks)1345 zvol_dump(dev_t dev, caddr_t addr, daddr_t blkno, int nblocks)
1346 {
1347 minor_t minor = getminor(dev);
1348 zvol_state_t *zv;
1349 int error = 0;
1350 uint64_t size;
1351 uint64_t boff;
1352 uint64_t resid;
1353
1354 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1355 if (zv == NULL)
1356 return (SET_ERROR(ENXIO));
1357
1358 if ((zv->zv_flags & ZVOL_DUMPIFIED) == 0)
1359 return (SET_ERROR(EINVAL));
1360
1361 boff = ldbtob(blkno);
1362 resid = ldbtob(nblocks);
1363
1364 VERIFY3U(boff + resid, <=, zv->zv_volsize);
1365
1366 while (resid) {
1367 size = MIN(resid, P2END(boff, zv->zv_volblocksize) - boff);
1368 error = zvol_dumpio(zv, addr, boff, size, B_FALSE, B_TRUE);
1369 if (error)
1370 break;
1371 boff += size;
1372 addr += size;
1373 resid -= size;
1374 }
1375
1376 return (error);
1377 }
1378
1379 /*ARGSUSED*/
1380 int
zvol_read(dev_t dev,uio_t * uio,cred_t * cr)1381 zvol_read(dev_t dev, uio_t *uio, cred_t *cr)
1382 {
1383 minor_t minor = getminor(dev);
1384 zvol_state_t *zv;
1385 uint64_t volsize;
1386 rl_t *rl;
1387 int error = 0;
1388
1389 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1390 if (zv == NULL)
1391 return (SET_ERROR(ENXIO));
1392
1393 volsize = zv->zv_volsize;
1394 if (uio->uio_resid > 0 &&
1395 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize))
1396 return (SET_ERROR(EIO));
1397
1398 if (zv->zv_flags & ZVOL_DUMPIFIED) {
1399 error = physio(zvol_strategy, NULL, dev, B_READ,
1400 zvol_minphys, uio);
1401 return (error);
1402 }
1403
1404 rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid,
1405 RL_READER);
1406 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) {
1407 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1);
1408
1409 /* don't read past the end */
1410 if (bytes > volsize - uio->uio_loffset)
1411 bytes = volsize - uio->uio_loffset;
1412
1413 error = dmu_read_uio(zv->zv_objset, ZVOL_OBJ, uio, bytes);
1414 if (error) {
1415 /* convert checksum errors into IO errors */
1416 if (error == ECKSUM)
1417 error = SET_ERROR(EIO);
1418 break;
1419 }
1420 }
1421 zfs_range_unlock(rl);
1422 return (error);
1423 }
1424
1425 /*ARGSUSED*/
1426 int
zvol_write(dev_t dev,uio_t * uio,cred_t * cr)1427 zvol_write(dev_t dev, uio_t *uio, cred_t *cr)
1428 {
1429 minor_t minor = getminor(dev);
1430 zvol_state_t *zv;
1431 uint64_t volsize;
1432 rl_t *rl;
1433 int error = 0;
1434 boolean_t sync;
1435
1436 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1437 if (zv == NULL)
1438 return (SET_ERROR(ENXIO));
1439
1440 volsize = zv->zv_volsize;
1441 if (uio->uio_resid > 0 &&
1442 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize))
1443 return (SET_ERROR(EIO));
1444
1445 if (zv->zv_flags & ZVOL_DUMPIFIED) {
1446 error = physio(zvol_strategy, NULL, dev, B_WRITE,
1447 zvol_minphys, uio);
1448 return (error);
1449 }
1450
1451 sync = !(zv->zv_flags & ZVOL_WCE) ||
1452 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS);
1453
1454 rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid,
1455 RL_WRITER);
1456 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) {
1457 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1);
1458 uint64_t off = uio->uio_loffset;
1459 dmu_tx_t *tx = dmu_tx_create(zv->zv_objset);
1460
1461 if (bytes > volsize - off) /* don't write past the end */
1462 bytes = volsize - off;
1463
1464 dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes);
1465 error = dmu_tx_assign(tx, TXG_WAIT);
1466 if (error) {
1467 dmu_tx_abort(tx);
1468 break;
1469 }
1470 error = dmu_write_uio_dbuf(zv->zv_dbuf, uio, bytes, tx);
1471 if (error == 0)
1472 zvol_log_write(zv, tx, off, bytes, sync);
1473 dmu_tx_commit(tx);
1474
1475 if (error)
1476 break;
1477 }
1478 zfs_range_unlock(rl);
1479 if (sync)
1480 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1481 return (error);
1482 }
1483
1484 int
zvol_getefi(void * arg,int flag,uint64_t vs,uint8_t bs)1485 zvol_getefi(void *arg, int flag, uint64_t vs, uint8_t bs)
1486 {
1487 struct uuid uuid = EFI_RESERVED;
1488 efi_gpe_t gpe = { 0 };
1489 uint32_t crc;
1490 dk_efi_t efi;
1491 int length;
1492 char *ptr;
1493
1494 if (ddi_copyin(arg, &efi, sizeof (dk_efi_t), flag))
1495 return (SET_ERROR(EFAULT));
1496 ptr = (char *)(uintptr_t)efi.dki_data_64;
1497 length = efi.dki_length;
1498 /*
1499 * Some clients may attempt to request a PMBR for the
1500 * zvol. Currently this interface will return EINVAL to
1501 * such requests. These requests could be supported by
1502 * adding a check for lba == 0 and consing up an appropriate
1503 * PMBR.
1504 */
1505 if (efi.dki_lba < 1 || efi.dki_lba > 2 || length <= 0)
1506 return (SET_ERROR(EINVAL));
1507
1508 gpe.efi_gpe_StartingLBA = LE_64(34ULL);
1509 gpe.efi_gpe_EndingLBA = LE_64((vs >> bs) - 1);
1510 UUID_LE_CONVERT(gpe.efi_gpe_PartitionTypeGUID, uuid);
1511
1512 if (efi.dki_lba == 1) {
1513 efi_gpt_t gpt = { 0 };
1514
1515 gpt.efi_gpt_Signature = LE_64(EFI_SIGNATURE);
1516 gpt.efi_gpt_Revision = LE_32(EFI_VERSION_CURRENT);
1517 gpt.efi_gpt_HeaderSize = LE_32(sizeof (gpt));
1518 gpt.efi_gpt_MyLBA = LE_64(1ULL);
1519 gpt.efi_gpt_FirstUsableLBA = LE_64(34ULL);
1520 gpt.efi_gpt_LastUsableLBA = LE_64((vs >> bs) - 1);
1521 gpt.efi_gpt_PartitionEntryLBA = LE_64(2ULL);
1522 gpt.efi_gpt_NumberOfPartitionEntries = LE_32(1);
1523 gpt.efi_gpt_SizeOfPartitionEntry =
1524 LE_32(sizeof (efi_gpe_t));
1525 CRC32(crc, &gpe, sizeof (gpe), -1U, crc32_table);
1526 gpt.efi_gpt_PartitionEntryArrayCRC32 = LE_32(~crc);
1527 CRC32(crc, &gpt, sizeof (gpt), -1U, crc32_table);
1528 gpt.efi_gpt_HeaderCRC32 = LE_32(~crc);
1529 if (ddi_copyout(&gpt, ptr, MIN(sizeof (gpt), length),
1530 flag))
1531 return (SET_ERROR(EFAULT));
1532 ptr += sizeof (gpt);
1533 length -= sizeof (gpt);
1534 }
1535 if (length > 0 && ddi_copyout(&gpe, ptr, MIN(sizeof (gpe),
1536 length), flag))
1537 return (SET_ERROR(EFAULT));
1538 return (0);
1539 }
1540
1541 /*
1542 * BEGIN entry points to allow external callers access to the volume.
1543 */
1544 /*
1545 * Return the volume parameters needed for access from an external caller.
1546 * These values are invariant as long as the volume is held open.
1547 */
1548 int
zvol_get_volume_params(minor_t minor,uint64_t * blksize,uint64_t * max_xfer_len,void ** minor_hdl,void ** objset_hdl,void ** zil_hdl,void ** rl_hdl,void ** bonus_hdl)1549 zvol_get_volume_params(minor_t minor, uint64_t *blksize,
1550 uint64_t *max_xfer_len, void **minor_hdl, void **objset_hdl, void **zil_hdl,
1551 void **rl_hdl, void **bonus_hdl)
1552 {
1553 zvol_state_t *zv;
1554
1555 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1556 if (zv == NULL)
1557 return (SET_ERROR(ENXIO));
1558 if (zv->zv_flags & ZVOL_DUMPIFIED)
1559 return (SET_ERROR(ENXIO));
1560
1561 ASSERT(blksize && max_xfer_len && minor_hdl &&
1562 objset_hdl && zil_hdl && rl_hdl && bonus_hdl);
1563
1564 *blksize = zv->zv_volblocksize;
1565 *max_xfer_len = (uint64_t)zvol_maxphys;
1566 *minor_hdl = zv;
1567 *objset_hdl = zv->zv_objset;
1568 *zil_hdl = zv->zv_zilog;
1569 *rl_hdl = &zv->zv_znode;
1570 *bonus_hdl = zv->zv_dbuf;
1571 return (0);
1572 }
1573
1574 /*
1575 * Return the current volume size to an external caller.
1576 * The size can change while the volume is open.
1577 */
1578 uint64_t
zvol_get_volume_size(void * minor_hdl)1579 zvol_get_volume_size(void *minor_hdl)
1580 {
1581 zvol_state_t *zv = minor_hdl;
1582
1583 return (zv->zv_volsize);
1584 }
1585
1586 /*
1587 * Return the current WCE setting to an external caller.
1588 * The WCE setting can change while the volume is open.
1589 */
1590 int
zvol_get_volume_wce(void * minor_hdl)1591 zvol_get_volume_wce(void *minor_hdl)
1592 {
1593 zvol_state_t *zv = minor_hdl;
1594
1595 return ((zv->zv_flags & ZVOL_WCE) ? 1 : 0);
1596 }
1597
1598 /*
1599 * Entry point for external callers to zvol_log_write
1600 */
1601 void
zvol_log_write_minor(void * minor_hdl,dmu_tx_t * tx,offset_t off,ssize_t resid,boolean_t sync)1602 zvol_log_write_minor(void *minor_hdl, dmu_tx_t *tx, offset_t off, ssize_t resid,
1603 boolean_t sync)
1604 {
1605 zvol_state_t *zv = minor_hdl;
1606
1607 zvol_log_write(zv, tx, off, resid, sync);
1608 }
1609 /*
1610 * END entry points to allow external callers access to the volume.
1611 */
1612
1613 /*
1614 * Log a DKIOCFREE/free-long-range to the ZIL with TX_TRUNCATE.
1615 */
1616 static void
zvol_log_truncate(zvol_state_t * zv,dmu_tx_t * tx,uint64_t off,uint64_t len,boolean_t sync)1617 zvol_log_truncate(zvol_state_t *zv, dmu_tx_t *tx, uint64_t off, uint64_t len,
1618 boolean_t sync)
1619 {
1620 itx_t *itx;
1621 lr_truncate_t *lr;
1622 zilog_t *zilog = zv->zv_zilog;
1623
1624 if (zil_replaying(zilog, tx))
1625 return;
1626
1627 itx = zil_itx_create(TX_TRUNCATE, sizeof (*lr));
1628 lr = (lr_truncate_t *)&itx->itx_lr;
1629 lr->lr_foid = ZVOL_OBJ;
1630 lr->lr_offset = off;
1631 lr->lr_length = len;
1632
1633 itx->itx_sync = sync;
1634 zil_itx_assign(zilog, itx, tx);
1635
1636 rw_enter(&rz_zev_rwlock, RW_READER);
1637 if (rz_zev_callbacks && rz_zev_callbacks->rz_zev_zvol_truncate)
1638 rz_zev_callbacks->rz_zev_zvol_truncate(zv->zv_name,
1639 zv->zv_objset, tx, off, len);
1640 rw_exit(&rz_zev_rwlock);
1641 }
1642
1643 /*
1644 * Dirtbag ioctls to support mkfs(1M) for UFS filesystems. See dkio(7I).
1645 * Also a dirtbag dkio ioctl for unmap/free-block functionality.
1646 */
1647 /*ARGSUSED*/
1648 int
zvol_ioctl(dev_t dev,int cmd,intptr_t arg,int flag,cred_t * cr,int * rvalp)1649 zvol_ioctl(dev_t dev, int cmd, intptr_t arg, int flag, cred_t *cr, int *rvalp)
1650 {
1651 zvol_state_t *zv;
1652 struct dk_callback *dkc;
1653 int error = 0;
1654 rl_t *rl;
1655
1656 mutex_enter(&zfsdev_state_lock);
1657
1658 zv = zfsdev_get_soft_state(getminor(dev), ZSST_ZVOL);
1659
1660 if (zv == NULL) {
1661 mutex_exit(&zfsdev_state_lock);
1662 return (SET_ERROR(ENXIO));
1663 }
1664 ASSERT(zv->zv_total_opens > 0);
1665
1666 switch (cmd) {
1667
1668 case DKIOCINFO:
1669 {
1670 struct dk_cinfo dki;
1671
1672 bzero(&dki, sizeof (dki));
1673 (void) strcpy(dki.dki_cname, "zvol");
1674 (void) strcpy(dki.dki_dname, "zvol");
1675 dki.dki_ctype = DKC_UNKNOWN;
1676 dki.dki_unit = getminor(dev);
1677 dki.dki_maxtransfer =
1678 1 << (SPA_OLD_MAXBLOCKSHIFT - zv->zv_min_bs);
1679 mutex_exit(&zfsdev_state_lock);
1680 if (ddi_copyout(&dki, (void *)arg, sizeof (dki), flag))
1681 error = SET_ERROR(EFAULT);
1682 return (error);
1683 }
1684
1685 case DKIOCGMEDIAINFO:
1686 {
1687 struct dk_minfo dkm;
1688
1689 bzero(&dkm, sizeof (dkm));
1690 dkm.dki_lbsize = 1U << zv->zv_min_bs;
1691 dkm.dki_capacity = zv->zv_volsize >> zv->zv_min_bs;
1692 dkm.dki_media_type = DK_UNKNOWN;
1693 mutex_exit(&zfsdev_state_lock);
1694 if (ddi_copyout(&dkm, (void *)arg, sizeof (dkm), flag))
1695 error = SET_ERROR(EFAULT);
1696 return (error);
1697 }
1698
1699 case DKIOCGMEDIAINFOEXT:
1700 {
1701 struct dk_minfo_ext dkmext;
1702
1703 bzero(&dkmext, sizeof (dkmext));
1704 dkmext.dki_lbsize = 1U << zv->zv_min_bs;
1705 dkmext.dki_pbsize = zv->zv_volblocksize;
1706 dkmext.dki_capacity = zv->zv_volsize >> zv->zv_min_bs;
1707 dkmext.dki_media_type = DK_UNKNOWN;
1708 mutex_exit(&zfsdev_state_lock);
1709 if (ddi_copyout(&dkmext, (void *)arg, sizeof (dkmext), flag))
1710 error = SET_ERROR(EFAULT);
1711 return (error);
1712 }
1713
1714 case DKIOCGETEFI:
1715 {
1716 uint64_t vs = zv->zv_volsize;
1717 uint8_t bs = zv->zv_min_bs;
1718
1719 mutex_exit(&zfsdev_state_lock);
1720 error = zvol_getefi((void *)arg, flag, vs, bs);
1721 return (error);
1722 }
1723
1724 case DKIOCFLUSHWRITECACHE:
1725 dkc = (struct dk_callback *)arg;
1726 mutex_exit(&zfsdev_state_lock);
1727 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1728 if ((flag & FKIOCTL) && dkc != NULL && dkc->dkc_callback) {
1729 (*dkc->dkc_callback)(dkc->dkc_cookie, error);
1730 error = 0;
1731 }
1732 return (error);
1733
1734 case DKIOCGETWCE:
1735 {
1736 int wce = (zv->zv_flags & ZVOL_WCE) ? 1 : 0;
1737 if (ddi_copyout(&wce, (void *)arg, sizeof (int),
1738 flag))
1739 error = SET_ERROR(EFAULT);
1740 break;
1741 }
1742 case DKIOCSETWCE:
1743 {
1744 int wce;
1745 if (ddi_copyin((void *)arg, &wce, sizeof (int),
1746 flag)) {
1747 error = SET_ERROR(EFAULT);
1748 break;
1749 }
1750 if (wce) {
1751 zv->zv_flags |= ZVOL_WCE;
1752 mutex_exit(&zfsdev_state_lock);
1753 } else {
1754 zv->zv_flags &= ~ZVOL_WCE;
1755 mutex_exit(&zfsdev_state_lock);
1756 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1757 }
1758 return (0);
1759 }
1760
1761 case DKIOCGGEOM:
1762 case DKIOCGVTOC:
1763 /*
1764 * commands using these (like prtvtoc) expect ENOTSUP
1765 * since we're emulating an EFI label
1766 */
1767 error = SET_ERROR(ENOTSUP);
1768 break;
1769
1770 case DKIOCDUMPINIT:
1771 rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize,
1772 RL_WRITER);
1773 error = zvol_dumpify(zv);
1774 zfs_range_unlock(rl);
1775 break;
1776
1777 case DKIOCDUMPFINI:
1778 if (!(zv->zv_flags & ZVOL_DUMPIFIED))
1779 break;
1780 rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize,
1781 RL_WRITER);
1782 error = zvol_dump_fini(zv);
1783 zfs_range_unlock(rl);
1784 break;
1785
1786 case DKIOCFREE:
1787 {
1788 dkioc_free_t df;
1789 dmu_tx_t *tx;
1790
1791 if (!zvol_unmap_enabled)
1792 break;
1793
1794 if (ddi_copyin((void *)arg, &df, sizeof (df), flag)) {
1795 error = SET_ERROR(EFAULT);
1796 break;
1797 }
1798
1799 /*
1800 * Apply Postel's Law to length-checking. If they overshoot,
1801 * just blank out until the end, if there's a need to blank
1802 * out anything.
1803 */
1804 if (df.df_start >= zv->zv_volsize)
1805 break; /* No need to do anything... */
1806
1807 mutex_exit(&zfsdev_state_lock);
1808
1809 rl = zfs_range_lock(&zv->zv_znode, df.df_start, df.df_length,
1810 RL_WRITER);
1811 tx = dmu_tx_create(zv->zv_objset);
1812 dmu_tx_mark_netfree(tx);
1813 error = dmu_tx_assign(tx, TXG_WAIT);
1814 if (error != 0) {
1815 dmu_tx_abort(tx);
1816 } else {
1817 zvol_log_truncate(zv, tx, df.df_start,
1818 df.df_length, B_TRUE);
1819 dmu_tx_commit(tx);
1820 error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ,
1821 df.df_start, df.df_length);
1822 }
1823
1824 zfs_range_unlock(rl);
1825
1826 if (error == 0) {
1827 /*
1828 * If the write-cache is disabled or 'sync' property
1829 * is set to 'always' then treat this as a synchronous
1830 * operation (i.e. commit to zil).
1831 */
1832 if (!(zv->zv_flags & ZVOL_WCE) ||
1833 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS))
1834 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1835
1836 /*
1837 * If the caller really wants synchronous writes, and
1838 * can't wait for them, don't return until the write
1839 * is done.
1840 */
1841 if (df.df_flags & DF_WAIT_SYNC) {
1842 txg_wait_synced(
1843 dmu_objset_pool(zv->zv_objset), 0);
1844 }
1845 }
1846 return (error);
1847 }
1848
1849 default:
1850 error = SET_ERROR(ENOTTY);
1851 break;
1852
1853 }
1854 mutex_exit(&zfsdev_state_lock);
1855 return (error);
1856 }
1857
1858 int
zvol_busy(void)1859 zvol_busy(void)
1860 {
1861 return (zvol_minors != 0);
1862 }
1863
1864 void
zvol_init(void)1865 zvol_init(void)
1866 {
1867 VERIFY(ddi_soft_state_init(&zfsdev_state, sizeof (zfs_soft_state_t),
1868 1) == 0);
1869 mutex_init(&zfsdev_state_lock, NULL, MUTEX_DEFAULT, NULL);
1870 }
1871
1872 void
zvol_fini(void)1873 zvol_fini(void)
1874 {
1875 mutex_destroy(&zfsdev_state_lock);
1876 ddi_soft_state_fini(&zfsdev_state);
1877 }
1878
1879 /*ARGSUSED*/
1880 static int
zfs_mvdev_dump_feature_check(void * arg,dmu_tx_t * tx)1881 zfs_mvdev_dump_feature_check(void *arg, dmu_tx_t *tx)
1882 {
1883 spa_t *spa = dmu_tx_pool(tx)->dp_spa;
1884
1885 if (spa_feature_is_active(spa, SPA_FEATURE_MULTI_VDEV_CRASH_DUMP))
1886 return (1);
1887 return (0);
1888 }
1889
1890 /*ARGSUSED*/
1891 static void
zfs_mvdev_dump_activate_feature_sync(void * arg,dmu_tx_t * tx)1892 zfs_mvdev_dump_activate_feature_sync(void *arg, dmu_tx_t *tx)
1893 {
1894 spa_t *spa = dmu_tx_pool(tx)->dp_spa;
1895
1896 spa_feature_incr(spa, SPA_FEATURE_MULTI_VDEV_CRASH_DUMP, tx);
1897 }
1898
1899 static int
zvol_dump_init(zvol_state_t * zv,boolean_t resize)1900 zvol_dump_init(zvol_state_t *zv, boolean_t resize)
1901 {
1902 dmu_tx_t *tx;
1903 int error;
1904 objset_t *os = zv->zv_objset;
1905 spa_t *spa = dmu_objset_spa(os);
1906 vdev_t *vd = spa->spa_root_vdev;
1907 nvlist_t *nv = NULL;
1908 uint64_t version = spa_version(spa);
1909 enum zio_checksum checksum;
1910
1911 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
1912 ASSERT(vd->vdev_ops == &vdev_root_ops);
1913
1914 error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, 0,
1915 DMU_OBJECT_END);
1916 /* wait for dmu_free_long_range to actually free the blocks */
1917 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
1918
1919 /*
1920 * If the pool on which the dump device is being initialized has more
1921 * than one child vdev, check that the MULTI_VDEV_CRASH_DUMP feature is
1922 * enabled. If so, bump that feature's counter to indicate that the
1923 * feature is active. We also check the vdev type to handle the
1924 * following case:
1925 * # zpool create test raidz disk1 disk2 disk3
1926 * Now have spa_root_vdev->vdev_children == 1 (the raidz vdev),
1927 * the raidz vdev itself has 3 children.
1928 */
1929 if (vd->vdev_children > 1 || vd->vdev_ops == &vdev_raidz_ops) {
1930 if (!spa_feature_is_enabled(spa,
1931 SPA_FEATURE_MULTI_VDEV_CRASH_DUMP))
1932 return (SET_ERROR(ENOTSUP));
1933 (void) dsl_sync_task(spa_name(spa),
1934 zfs_mvdev_dump_feature_check,
1935 zfs_mvdev_dump_activate_feature_sync, NULL,
1936 2, ZFS_SPACE_CHECK_RESERVED);
1937 }
1938
1939 tx = dmu_tx_create(os);
1940 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
1941 dmu_tx_hold_bonus(tx, ZVOL_OBJ);
1942 error = dmu_tx_assign(tx, TXG_WAIT);
1943 if (error) {
1944 dmu_tx_abort(tx);
1945 return (error);
1946 }
1947
1948 /*
1949 * If MULTI_VDEV_CRASH_DUMP is active, use the NOPARITY checksum
1950 * function. Otherwise, use the old default -- OFF.
1951 */
1952 checksum = spa_feature_is_active(spa,
1953 SPA_FEATURE_MULTI_VDEV_CRASH_DUMP) ? ZIO_CHECKSUM_NOPARITY :
1954 ZIO_CHECKSUM_OFF;
1955
1956 /*
1957 * If we are resizing the dump device then we only need to
1958 * update the refreservation to match the newly updated
1959 * zvolsize. Otherwise, we save off the original state of the
1960 * zvol so that we can restore them if the zvol is ever undumpified.
1961 */
1962 if (resize) {
1963 error = zap_update(os, ZVOL_ZAP_OBJ,
1964 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1,
1965 &zv->zv_volsize, tx);
1966 } else {
1967 uint64_t checksum, compress, refresrv, vbs, dedup;
1968
1969 error = dsl_prop_get_integer(zv->zv_name,
1970 zfs_prop_to_name(ZFS_PROP_COMPRESSION), &compress, NULL);
1971 error = error ? error : dsl_prop_get_integer(zv->zv_name,
1972 zfs_prop_to_name(ZFS_PROP_CHECKSUM), &checksum, NULL);
1973 error = error ? error : dsl_prop_get_integer(zv->zv_name,
1974 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), &refresrv, NULL);
1975 error = error ? error : dsl_prop_get_integer(zv->zv_name,
1976 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &vbs, NULL);
1977 if (version >= SPA_VERSION_DEDUP) {
1978 error = error ? error :
1979 dsl_prop_get_integer(zv->zv_name,
1980 zfs_prop_to_name(ZFS_PROP_DEDUP), &dedup, NULL);
1981 }
1982
1983 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ,
1984 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1,
1985 &compress, tx);
1986 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ,
1987 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1, &checksum, tx);
1988 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ,
1989 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1,
1990 &refresrv, tx);
1991 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ,
1992 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1,
1993 &vbs, tx);
1994 error = error ? error : dmu_object_set_blocksize(
1995 os, ZVOL_OBJ, SPA_OLD_MAXBLOCKSIZE, 0, tx);
1996 if (version >= SPA_VERSION_DEDUP) {
1997 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ,
1998 zfs_prop_to_name(ZFS_PROP_DEDUP), 8, 1,
1999 &dedup, tx);
2000 }
2001 if (error == 0)
2002 zv->zv_volblocksize = SPA_OLD_MAXBLOCKSIZE;
2003 }
2004 dmu_tx_commit(tx);
2005
2006 /*
2007 * We only need update the zvol's property if we are initializing
2008 * the dump area for the first time.
2009 */
2010 if (!resize) {
2011 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2012 VERIFY(nvlist_add_uint64(nv,
2013 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 0) == 0);
2014 VERIFY(nvlist_add_uint64(nv,
2015 zfs_prop_to_name(ZFS_PROP_COMPRESSION),
2016 ZIO_COMPRESS_OFF) == 0);
2017 VERIFY(nvlist_add_uint64(nv,
2018 zfs_prop_to_name(ZFS_PROP_CHECKSUM),
2019 checksum) == 0);
2020 if (version >= SPA_VERSION_DEDUP) {
2021 VERIFY(nvlist_add_uint64(nv,
2022 zfs_prop_to_name(ZFS_PROP_DEDUP),
2023 ZIO_CHECKSUM_OFF) == 0);
2024 }
2025
2026 error = zfs_set_prop_nvlist(zv->zv_name, ZPROP_SRC_LOCAL,
2027 nv, NULL);
2028 nvlist_free(nv);
2029
2030 if (error)
2031 return (error);
2032 }
2033
2034 /* Allocate the space for the dump */
2035 error = zvol_prealloc(zv);
2036 return (error);
2037 }
2038
2039 static int
zvol_dumpify(zvol_state_t * zv)2040 zvol_dumpify(zvol_state_t *zv)
2041 {
2042 int error = 0;
2043 uint64_t dumpsize = 0;
2044 dmu_tx_t *tx;
2045 objset_t *os = zv->zv_objset;
2046
2047 if (zv->zv_flags & ZVOL_RDONLY)
2048 return (SET_ERROR(EROFS));
2049
2050 if (zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE,
2051 8, 1, &dumpsize) != 0 || dumpsize != zv->zv_volsize) {
2052 boolean_t resize = (dumpsize > 0);
2053
2054 if ((error = zvol_dump_init(zv, resize)) != 0) {
2055 (void) zvol_dump_fini(zv);
2056 return (error);
2057 }
2058 }
2059
2060 /*
2061 * Build up our lba mapping.
2062 */
2063 error = zvol_get_lbas(zv);
2064 if (error) {
2065 (void) zvol_dump_fini(zv);
2066 return (error);
2067 }
2068
2069 tx = dmu_tx_create(os);
2070 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
2071 error = dmu_tx_assign(tx, TXG_WAIT);
2072 if (error) {
2073 dmu_tx_abort(tx);
2074 (void) zvol_dump_fini(zv);
2075 return (error);
2076 }
2077
2078 zv->zv_flags |= ZVOL_DUMPIFIED;
2079 error = zap_update(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, 8, 1,
2080 &zv->zv_volsize, tx);
2081 dmu_tx_commit(tx);
2082
2083 if (error) {
2084 (void) zvol_dump_fini(zv);
2085 return (error);
2086 }
2087
2088 txg_wait_synced(dmu_objset_pool(os), 0);
2089 return (0);
2090 }
2091
2092 static int
zvol_dump_fini(zvol_state_t * zv)2093 zvol_dump_fini(zvol_state_t *zv)
2094 {
2095 dmu_tx_t *tx;
2096 objset_t *os = zv->zv_objset;
2097 nvlist_t *nv;
2098 int error = 0;
2099 uint64_t checksum, compress, refresrv, vbs, dedup;
2100 uint64_t version = spa_version(dmu_objset_spa(zv->zv_objset));
2101
2102 /*
2103 * Attempt to restore the zvol back to its pre-dumpified state.
2104 * This is a best-effort attempt as it's possible that not all
2105 * of these properties were initialized during the dumpify process
2106 * (i.e. error during zvol_dump_init).
2107 */
2108
2109 tx = dmu_tx_create(os);
2110 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
2111 error = dmu_tx_assign(tx, TXG_WAIT);
2112 if (error) {
2113 dmu_tx_abort(tx);
2114 return (error);
2115 }
2116 (void) zap_remove(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, tx);
2117 dmu_tx_commit(tx);
2118
2119 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2120 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1, &checksum);
2121 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2122 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1, &compress);
2123 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2124 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, &refresrv);
2125 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2126 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1, &vbs);
2127
2128 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2129 (void) nvlist_add_uint64(nv,
2130 zfs_prop_to_name(ZFS_PROP_CHECKSUM), checksum);
2131 (void) nvlist_add_uint64(nv,
2132 zfs_prop_to_name(ZFS_PROP_COMPRESSION), compress);
2133 (void) nvlist_add_uint64(nv,
2134 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), refresrv);
2135 if (version >= SPA_VERSION_DEDUP &&
2136 zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2137 zfs_prop_to_name(ZFS_PROP_DEDUP), 8, 1, &dedup) == 0) {
2138 (void) nvlist_add_uint64(nv,
2139 zfs_prop_to_name(ZFS_PROP_DEDUP), dedup);
2140 }
2141 (void) zfs_set_prop_nvlist(zv->zv_name, ZPROP_SRC_LOCAL,
2142 nv, NULL);
2143 nvlist_free(nv);
2144
2145 zvol_free_extents(zv);
2146 zv->zv_flags &= ~ZVOL_DUMPIFIED;
2147 (void) dmu_free_long_range(os, ZVOL_OBJ, 0, DMU_OBJECT_END);
2148 /* wait for dmu_free_long_range to actually free the blocks */
2149 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
2150 tx = dmu_tx_create(os);
2151 dmu_tx_hold_bonus(tx, ZVOL_OBJ);
2152 error = dmu_tx_assign(tx, TXG_WAIT);
2153 if (error) {
2154 dmu_tx_abort(tx);
2155 return (error);
2156 }
2157 if (dmu_object_set_blocksize(os, ZVOL_OBJ, vbs, 0, tx) == 0)
2158 zv->zv_volblocksize = vbs;
2159 dmu_tx_commit(tx);
2160
2161 return (0);
2162 }
2163