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 * 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/zfs_events.h>
89 #include <sys/dmu_tx.h>
90 #include <sys/zfeature.h>
91 #include <sys/zio_checksum.h>
92
93 #include "zfs_namecheck.h"
94
95 void *zfsdev_state;
96 static char *zvol_tag = "zvol_tag";
97
98 #define ZVOL_DUMPSIZE "dumpsize"
99
100 /*
101 * This lock protects the zfsdev_state structure from being modified
102 * while it's being used, e.g. an open that comes in before a create
103 * finishes. It also protects temporary opens of the dataset so that,
104 * e.g., an open doesn't get a spurious EBUSY.
105 */
106 kmutex_t zfsdev_state_lock;
107 static uint32_t zvol_minors;
108
109 typedef struct zvol_extent {
110 list_node_t ze_node;
111 dva_t ze_dva; /* dva associated with this extent */
112 uint64_t ze_nblks; /* number of blocks in extent */
113 } zvol_extent_t;
114
115 /*
116 * The in-core state of each volume.
117 */
118 typedef struct zvol_state {
119 char zv_name[MAXPATHLEN]; /* pool/dd name */
120 uint64_t zv_volsize; /* amount of space we advertise */
121 uint64_t zv_volblocksize; /* volume block size */
122 minor_t zv_minor; /* minor number */
123 uint8_t zv_min_bs; /* minimum addressable block shift */
124 uint8_t zv_flags; /* readonly, dumpified, etc. */
125 objset_t *zv_objset; /* objset handle */
126 uint32_t zv_open_count[OTYPCNT]; /* open counts */
127 uint32_t zv_total_opens; /* total open count */
128 zilog_t *zv_zilog; /* ZIL handle */
129 list_t zv_extents; /* List of extents for dump */
130 znode_t zv_znode; /* for range locking */
131 dmu_buf_t *zv_dbuf; /* bonus handle */
132 } zvol_state_t;
133
134 /*
135 * zvol specific flags
136 */
137 #define ZVOL_RDONLY 0x1
138 #define ZVOL_DUMPIFIED 0x2
139 #define ZVOL_EXCL 0x4
140 #define ZVOL_WCE 0x8
141
142 /*
143 * zvol maximum transfer in one DMU tx.
144 */
145 int zvol_maxphys = DMU_MAX_ACCESS/2;
146
147 /*
148 * Toggle unmap functionality.
149 */
150 boolean_t zvol_unmap_enabled = B_TRUE;
151
152 extern int zfs_set_prop_nvlist(const char *, zprop_source_t,
153 nvlist_t *, nvlist_t *);
154 static int zvol_remove_zv(zvol_state_t *);
155 static int zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio);
156 static int zvol_dumpify(zvol_state_t *zv);
157 static int zvol_dump_fini(zvol_state_t *zv);
158 static int zvol_dump_init(zvol_state_t *zv, boolean_t resize);
159
160 static void
zvol_size_changed(zvol_state_t * zv,uint64_t volsize)161 zvol_size_changed(zvol_state_t *zv, uint64_t volsize)
162 {
163 dev_t dev = makedevice(ddi_driver_major(zfs_dip), zv->zv_minor);
164
165 zv->zv_volsize = volsize;
166 VERIFY(ddi_prop_update_int64(dev, zfs_dip,
167 "Size", volsize) == DDI_SUCCESS);
168 VERIFY(ddi_prop_update_int64(dev, zfs_dip,
169 "Nblocks", lbtodb(volsize)) == DDI_SUCCESS);
170
171 /* Notify specfs to invalidate the cached size */
172 spec_size_invalidate(dev, VBLK);
173 spec_size_invalidate(dev, VCHR);
174 }
175
176 int
zvol_check_volsize(uint64_t volsize,uint64_t blocksize)177 zvol_check_volsize(uint64_t volsize, uint64_t blocksize)
178 {
179 if (volsize == 0)
180 return (SET_ERROR(EINVAL));
181
182 if (volsize % blocksize != 0)
183 return (SET_ERROR(EINVAL));
184
185 #ifdef _ILP32
186 if (volsize - 1 > SPEC_MAXOFFSET_T)
187 return (SET_ERROR(EOVERFLOW));
188 #endif
189 return (0);
190 }
191
192 int
zvol_check_volblocksize(uint64_t volblocksize)193 zvol_check_volblocksize(uint64_t volblocksize)
194 {
195 if (volblocksize < SPA_MINBLOCKSIZE ||
196 volblocksize > SPA_OLD_MAXBLOCKSIZE ||
197 !ISP2(volblocksize))
198 return (SET_ERROR(EDOM));
199
200 return (0);
201 }
202
203 int
zvol_get_stats(objset_t * os,nvlist_t * nv)204 zvol_get_stats(objset_t *os, nvlist_t *nv)
205 {
206 int error;
207 dmu_object_info_t doi;
208 uint64_t val;
209
210 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &val);
211 if (error)
212 return (error);
213
214 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLSIZE, val);
215
216 error = dmu_object_info(os, ZVOL_OBJ, &doi);
217
218 if (error == 0) {
219 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLBLOCKSIZE,
220 doi.doi_data_block_size);
221 }
222
223 return (error);
224 }
225
226 static zvol_state_t *
zvol_minor_lookup(const char * name)227 zvol_minor_lookup(const char *name)
228 {
229 minor_t minor;
230 zvol_state_t *zv;
231
232 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
233
234 for (minor = 1; minor <= ZFSDEV_MAX_MINOR; minor++) {
235 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
236 if (zv == NULL)
237 continue;
238 if (strcmp(zv->zv_name, name) == 0)
239 return (zv);
240 }
241
242 return (NULL);
243 }
244
245 /* extent mapping arg */
246 struct maparg {
247 zvol_state_t *ma_zv;
248 uint64_t ma_blks;
249 };
250
251 /*ARGSUSED*/
252 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)253 zvol_map_block(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
254 const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
255 {
256 struct maparg *ma = arg;
257 zvol_extent_t *ze;
258 int bs = ma->ma_zv->zv_volblocksize;
259
260 if (bp == NULL || BP_IS_HOLE(bp) ||
261 zb->zb_object != ZVOL_OBJ || zb->zb_level != 0)
262 return (0);
263
264 VERIFY(!BP_IS_EMBEDDED(bp));
265
266 VERIFY3U(ma->ma_blks, ==, zb->zb_blkid);
267 ma->ma_blks++;
268
269 /* Abort immediately if we have encountered gang blocks */
270 if (BP_IS_GANG(bp))
271 return (SET_ERROR(EFRAGS));
272
273 /*
274 * See if the block is at the end of the previous extent.
275 */
276 ze = list_tail(&ma->ma_zv->zv_extents);
277 if (ze &&
278 DVA_GET_VDEV(BP_IDENTITY(bp)) == DVA_GET_VDEV(&ze->ze_dva) &&
279 DVA_GET_OFFSET(BP_IDENTITY(bp)) ==
280 DVA_GET_OFFSET(&ze->ze_dva) + ze->ze_nblks * bs) {
281 ze->ze_nblks++;
282 return (0);
283 }
284
285 dprintf_bp(bp, "%s", "next blkptr:");
286
287 /* start a new extent */
288 ze = kmem_zalloc(sizeof (zvol_extent_t), KM_SLEEP);
289 ze->ze_dva = bp->blk_dva[0]; /* structure assignment */
290 ze->ze_nblks = 1;
291 list_insert_tail(&ma->ma_zv->zv_extents, ze);
292 return (0);
293 }
294
295 static void
zvol_free_extents(zvol_state_t * zv)296 zvol_free_extents(zvol_state_t *zv)
297 {
298 zvol_extent_t *ze;
299
300 while (ze = list_head(&zv->zv_extents)) {
301 list_remove(&zv->zv_extents, ze);
302 kmem_free(ze, sizeof (zvol_extent_t));
303 }
304 }
305
306 static int
zvol_get_lbas(zvol_state_t * zv)307 zvol_get_lbas(zvol_state_t *zv)
308 {
309 objset_t *os = zv->zv_objset;
310 struct maparg ma;
311 int err;
312
313 ma.ma_zv = zv;
314 ma.ma_blks = 0;
315 zvol_free_extents(zv);
316
317 /* commit any in-flight changes before traversing the dataset */
318 txg_wait_synced(dmu_objset_pool(os), 0);
319 err = traverse_dataset(dmu_objset_ds(os), 0,
320 TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA, zvol_map_block, &ma);
321 if (err || ma.ma_blks != (zv->zv_volsize / zv->zv_volblocksize)) {
322 zvol_free_extents(zv);
323 return (err ? err : EIO);
324 }
325
326 return (0);
327 }
328
329 /* ARGSUSED */
330 void
zvol_create_cb(objset_t * os,void * arg,cred_t * cr,dmu_tx_t * tx)331 zvol_create_cb(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx)
332 {
333 zfs_creat_t *zct = arg;
334 nvlist_t *nvprops = zct->zct_props;
335 int error;
336 uint64_t volblocksize, volsize;
337
338 VERIFY(nvlist_lookup_uint64(nvprops,
339 zfs_prop_to_name(ZFS_PROP_VOLSIZE), &volsize) == 0);
340 if (nvlist_lookup_uint64(nvprops,
341 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &volblocksize) != 0)
342 volblocksize = zfs_prop_default_numeric(ZFS_PROP_VOLBLOCKSIZE);
343
344 /*
345 * These properties must be removed from the list so the generic
346 * property setting step won't apply to them.
347 */
348 VERIFY(nvlist_remove_all(nvprops,
349 zfs_prop_to_name(ZFS_PROP_VOLSIZE)) == 0);
350 (void) nvlist_remove_all(nvprops,
351 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE));
352
353 error = dmu_object_claim(os, ZVOL_OBJ, DMU_OT_ZVOL, volblocksize,
354 DMU_OT_NONE, 0, tx);
355 ASSERT(error == 0);
356
357 error = zap_create_claim(os, ZVOL_ZAP_OBJ, DMU_OT_ZVOL_PROP,
358 DMU_OT_NONE, 0, tx);
359 ASSERT(error == 0);
360
361 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize, tx);
362 ASSERT(error == 0);
363 }
364
365 /*
366 * Replay a TX_TRUNCATE ZIL transaction if asked. TX_TRUNCATE is how we
367 * implement DKIOCFREE/free-long-range.
368 */
369 static int
zvol_replay_truncate(zvol_state_t * zv,lr_truncate_t * lr,boolean_t byteswap)370 zvol_replay_truncate(zvol_state_t *zv, lr_truncate_t *lr, boolean_t byteswap)
371 {
372 uint64_t offset, length;
373
374 if (byteswap)
375 byteswap_uint64_array(lr, sizeof (*lr));
376
377 offset = lr->lr_offset;
378 length = lr->lr_length;
379
380 return (dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, offset, length));
381 }
382
383 /*
384 * Replay a TX_WRITE ZIL transaction that didn't get committed
385 * after a system failure
386 */
387 static int
zvol_replay_write(zvol_state_t * zv,lr_write_t * lr,boolean_t byteswap)388 zvol_replay_write(zvol_state_t *zv, lr_write_t *lr, boolean_t byteswap)
389 {
390 objset_t *os = zv->zv_objset;
391 char *data = (char *)(lr + 1); /* data follows lr_write_t */
392 uint64_t offset, length;
393 dmu_tx_t *tx;
394 int error;
395
396 if (byteswap)
397 byteswap_uint64_array(lr, sizeof (*lr));
398
399 offset = lr->lr_offset;
400 length = lr->lr_length;
401
402 /* If it's a dmu_sync() block, write the whole block */
403 if (lr->lr_common.lrc_reclen == sizeof (lr_write_t)) {
404 uint64_t blocksize = BP_GET_LSIZE(&lr->lr_blkptr);
405 if (length < blocksize) {
406 offset -= offset % blocksize;
407 length = blocksize;
408 }
409 }
410
411 tx = dmu_tx_create(os);
412 dmu_tx_hold_write(tx, ZVOL_OBJ, offset, length);
413 error = dmu_tx_assign(tx, TXG_WAIT);
414 if (error) {
415 dmu_tx_abort(tx);
416 } else {
417 dmu_write(os, ZVOL_OBJ, offset, length, data, tx);
418 dmu_tx_commit(tx);
419 }
420
421 return (error);
422 }
423
424 /* ARGSUSED */
425 static int
zvol_replay_err(zvol_state_t * zv,lr_t * lr,boolean_t byteswap)426 zvol_replay_err(zvol_state_t *zv, lr_t *lr, boolean_t byteswap)
427 {
428 return (SET_ERROR(ENOTSUP));
429 }
430
431 /*
432 * Callback vectors for replaying records.
433 * Only TX_WRITE and TX_TRUNCATE are needed for zvol.
434 */
435 zil_replay_func_t *zvol_replay_vector[TX_MAX_TYPE] = {
436 zvol_replay_err, /* 0 no such transaction type */
437 zvol_replay_err, /* TX_CREATE */
438 zvol_replay_err, /* TX_MKDIR */
439 zvol_replay_err, /* TX_MKXATTR */
440 zvol_replay_err, /* TX_SYMLINK */
441 zvol_replay_err, /* TX_REMOVE */
442 zvol_replay_err, /* TX_RMDIR */
443 zvol_replay_err, /* TX_LINK */
444 zvol_replay_err, /* TX_RENAME */
445 zvol_replay_write, /* TX_WRITE */
446 zvol_replay_truncate, /* TX_TRUNCATE */
447 zvol_replay_err, /* TX_SETATTR */
448 zvol_replay_err, /* TX_ACL */
449 zvol_replay_err, /* TX_CREATE_ACL */
450 zvol_replay_err, /* TX_CREATE_ATTR */
451 zvol_replay_err, /* TX_CREATE_ACL_ATTR */
452 zvol_replay_err, /* TX_MKDIR_ACL */
453 zvol_replay_err, /* TX_MKDIR_ATTR */
454 zvol_replay_err, /* TX_MKDIR_ACL_ATTR */
455 zvol_replay_err, /* TX_WRITE2 */
456 };
457
458 int
zvol_name2minor(const char * name,minor_t * minor)459 zvol_name2minor(const char *name, minor_t *minor)
460 {
461 zvol_state_t *zv;
462
463 mutex_enter(&zfsdev_state_lock);
464 zv = zvol_minor_lookup(name);
465 if (minor && zv)
466 *minor = zv->zv_minor;
467 mutex_exit(&zfsdev_state_lock);
468 return (zv ? 0 : -1);
469 }
470
471 /*
472 * Create a minor node (plus a whole lot more) for the specified volume.
473 */
474 int
zvol_create_minor(const char * name)475 zvol_create_minor(const char *name)
476 {
477 zfs_soft_state_t *zs;
478 zvol_state_t *zv;
479 objset_t *os;
480 dmu_object_info_t doi;
481 minor_t minor = 0;
482 char chrbuf[30], blkbuf[30];
483 int error;
484
485 mutex_enter(&zfsdev_state_lock);
486
487 if (zvol_minor_lookup(name) != NULL) {
488 mutex_exit(&zfsdev_state_lock);
489 return (SET_ERROR(EEXIST));
490 }
491
492 /* lie and say we're read-only */
493 error = dmu_objset_own(name, DMU_OST_ZVOL, B_TRUE, FTAG, &os);
494
495 if (error) {
496 mutex_exit(&zfsdev_state_lock);
497 return (error);
498 }
499
500 if ((minor = zfsdev_minor_alloc()) == 0) {
501 dmu_objset_disown(os, FTAG);
502 mutex_exit(&zfsdev_state_lock);
503 return (SET_ERROR(ENXIO));
504 }
505
506 if (ddi_soft_state_zalloc(zfsdev_state, minor) != DDI_SUCCESS) {
507 dmu_objset_disown(os, FTAG);
508 mutex_exit(&zfsdev_state_lock);
509 return (SET_ERROR(EAGAIN));
510 }
511 (void) ddi_prop_update_string(minor, zfs_dip, ZVOL_PROP_NAME,
512 (char *)name);
513
514 (void) snprintf(chrbuf, sizeof (chrbuf), "%u,raw", minor);
515
516 if (ddi_create_minor_node(zfs_dip, chrbuf, S_IFCHR,
517 minor, DDI_PSEUDO, 0) == DDI_FAILURE) {
518 ddi_soft_state_free(zfsdev_state, minor);
519 dmu_objset_disown(os, FTAG);
520 mutex_exit(&zfsdev_state_lock);
521 return (SET_ERROR(EAGAIN));
522 }
523
524 (void) snprintf(blkbuf, sizeof (blkbuf), "%u", minor);
525
526 if (ddi_create_minor_node(zfs_dip, blkbuf, S_IFBLK,
527 minor, DDI_PSEUDO, 0) == DDI_FAILURE) {
528 ddi_remove_minor_node(zfs_dip, chrbuf);
529 ddi_soft_state_free(zfsdev_state, minor);
530 dmu_objset_disown(os, FTAG);
531 mutex_exit(&zfsdev_state_lock);
532 return (SET_ERROR(EAGAIN));
533 }
534
535 zs = ddi_get_soft_state(zfsdev_state, minor);
536 zs->zss_type = ZSST_ZVOL;
537 zv = zs->zss_data = kmem_zalloc(sizeof (zvol_state_t), KM_SLEEP);
538 (void) strlcpy(zv->zv_name, name, MAXPATHLEN);
539 zv->zv_min_bs = DEV_BSHIFT;
540 zv->zv_minor = minor;
541 zv->zv_objset = os;
542 if (dmu_objset_is_snapshot(os) || !spa_writeable(dmu_objset_spa(os)))
543 zv->zv_flags |= ZVOL_RDONLY;
544 mutex_init(&zv->zv_znode.z_range_lock, NULL, MUTEX_DEFAULT, NULL);
545 avl_create(&zv->zv_znode.z_range_avl, zfs_range_compare,
546 sizeof (rl_t), offsetof(rl_t, r_node));
547 list_create(&zv->zv_extents, sizeof (zvol_extent_t),
548 offsetof(zvol_extent_t, ze_node));
549 /* get and cache the blocksize */
550 error = dmu_object_info(os, ZVOL_OBJ, &doi);
551 ASSERT(error == 0);
552 zv->zv_volblocksize = doi.doi_data_block_size;
553
554 if (spa_writeable(dmu_objset_spa(os))) {
555 if (zil_replay_disable)
556 zil_destroy(dmu_objset_zil(os), B_FALSE);
557 else
558 zil_replay(os, zv, zvol_replay_vector);
559 }
560 dmu_objset_disown(os, FTAG);
561 zv->zv_objset = NULL;
562
563 zvol_minors++;
564
565 mutex_exit(&zfsdev_state_lock);
566
567 return (0);
568 }
569
570 /*
571 * Remove minor node for the specified volume.
572 */
573 static int
zvol_remove_zv(zvol_state_t * zv)574 zvol_remove_zv(zvol_state_t *zv)
575 {
576 char nmbuf[20];
577 minor_t minor = zv->zv_minor;
578
579 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
580 if (zv->zv_total_opens != 0)
581 return (SET_ERROR(EBUSY));
582
583 (void) snprintf(nmbuf, sizeof (nmbuf), "%u,raw", minor);
584 ddi_remove_minor_node(zfs_dip, nmbuf);
585
586 (void) snprintf(nmbuf, sizeof (nmbuf), "%u", minor);
587 ddi_remove_minor_node(zfs_dip, nmbuf);
588
589 avl_destroy(&zv->zv_znode.z_range_avl);
590 mutex_destroy(&zv->zv_znode.z_range_lock);
591
592 kmem_free(zv, sizeof (zvol_state_t));
593
594 ddi_soft_state_free(zfsdev_state, minor);
595
596 zvol_minors--;
597 return (0);
598 }
599
600 int
zvol_remove_minor(const char * name)601 zvol_remove_minor(const char *name)
602 {
603 zvol_state_t *zv;
604 int rc;
605
606 mutex_enter(&zfsdev_state_lock);
607 if ((zv = zvol_minor_lookup(name)) == NULL) {
608 mutex_exit(&zfsdev_state_lock);
609 return (SET_ERROR(ENXIO));
610 }
611 rc = zvol_remove_zv(zv);
612 mutex_exit(&zfsdev_state_lock);
613 return (rc);
614 }
615
616 int
zvol_first_open(zvol_state_t * zv)617 zvol_first_open(zvol_state_t *zv)
618 {
619 objset_t *os;
620 uint64_t volsize;
621 int error;
622 uint64_t readonly;
623
624 /* lie and say we're read-only */
625 error = dmu_objset_own(zv->zv_name, DMU_OST_ZVOL, B_TRUE,
626 zvol_tag, &os);
627 if (error)
628 return (error);
629
630 zv->zv_objset = os;
631 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize);
632 if (error) {
633 ASSERT(error == 0);
634 dmu_objset_disown(os, zvol_tag);
635 return (error);
636 }
637
638 error = dmu_bonus_hold(os, ZVOL_OBJ, zvol_tag, &zv->zv_dbuf);
639 if (error) {
640 dmu_objset_disown(os, zvol_tag);
641 return (error);
642 }
643
644 zvol_size_changed(zv, volsize);
645 zv->zv_zilog = zil_open(os, zvol_get_data);
646
647 VERIFY(dsl_prop_get_integer(zv->zv_name, "readonly", &readonly,
648 NULL) == 0);
649 if (readonly || dmu_objset_is_snapshot(os) ||
650 !spa_writeable(dmu_objset_spa(os)))
651 zv->zv_flags |= ZVOL_RDONLY;
652 else
653 zv->zv_flags &= ~ZVOL_RDONLY;
654 return (error);
655 }
656
657 void
zvol_last_close(zvol_state_t * zv)658 zvol_last_close(zvol_state_t *zv)
659 {
660 zil_close(zv->zv_zilog);
661 zv->zv_zilog = NULL;
662
663 dmu_buf_rele(zv->zv_dbuf, zvol_tag);
664 zv->zv_dbuf = NULL;
665
666 /*
667 * Evict cached data
668 */
669 if (dsl_dataset_is_dirty(dmu_objset_ds(zv->zv_objset)) &&
670 !(zv->zv_flags & ZVOL_RDONLY))
671 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
672 dmu_objset_evict_dbufs(zv->zv_objset);
673
674 dmu_objset_disown(zv->zv_objset, zvol_tag);
675 zv->zv_objset = NULL;
676 }
677
678 int
zvol_prealloc(zvol_state_t * zv)679 zvol_prealloc(zvol_state_t *zv)
680 {
681 objset_t *os = zv->zv_objset;
682 dmu_tx_t *tx;
683 uint64_t refd, avail, usedobjs, availobjs;
684 uint64_t resid = zv->zv_volsize;
685 uint64_t off = 0;
686
687 /* Check the space usage before attempting to allocate the space */
688 dmu_objset_space(os, &refd, &avail, &usedobjs, &availobjs);
689 if (avail < zv->zv_volsize)
690 return (SET_ERROR(ENOSPC));
691
692 /* Free old extents if they exist */
693 zvol_free_extents(zv);
694
695 while (resid != 0) {
696 int error;
697 uint64_t bytes = MIN(resid, SPA_OLD_MAXBLOCKSIZE);
698
699 tx = dmu_tx_create(os);
700 dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes);
701 error = dmu_tx_assign(tx, TXG_WAIT);
702 if (error) {
703 dmu_tx_abort(tx);
704 (void) dmu_free_long_range(os, ZVOL_OBJ, 0, off);
705 return (error);
706 }
707 dmu_prealloc(os, ZVOL_OBJ, off, bytes, tx);
708 dmu_tx_commit(tx);
709 off += bytes;
710 resid -= bytes;
711 }
712 txg_wait_synced(dmu_objset_pool(os), 0);
713
714 return (0);
715 }
716
717 static int
zvol_update_volsize(objset_t * os,uint64_t volsize)718 zvol_update_volsize(objset_t *os, uint64_t volsize)
719 {
720 dmu_tx_t *tx;
721 int error;
722
723 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
724
725 tx = dmu_tx_create(os);
726 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
727 dmu_tx_mark_netfree(tx);
728 error = dmu_tx_assign(tx, TXG_WAIT);
729 if (error) {
730 dmu_tx_abort(tx);
731 return (error);
732 }
733
734 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1,
735 &volsize, tx);
736 dmu_tx_commit(tx);
737
738 if (error == 0)
739 error = dmu_free_long_range(os,
740 ZVOL_OBJ, volsize, DMU_OBJECT_END);
741 return (error);
742 }
743
744 void
zvol_remove_minors(const char * name)745 zvol_remove_minors(const char *name)
746 {
747 zvol_state_t *zv;
748 char *namebuf;
749 minor_t minor;
750
751 namebuf = kmem_zalloc(strlen(name) + 2, KM_SLEEP);
752 (void) strncpy(namebuf, name, strlen(name));
753 (void) strcat(namebuf, "/");
754 mutex_enter(&zfsdev_state_lock);
755 for (minor = 1; minor <= ZFSDEV_MAX_MINOR; minor++) {
756
757 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
758 if (zv == NULL)
759 continue;
760 if (strncmp(namebuf, zv->zv_name, strlen(namebuf)) == 0)
761 (void) zvol_remove_zv(zv);
762 }
763 kmem_free(namebuf, strlen(name) + 2);
764
765 mutex_exit(&zfsdev_state_lock);
766 }
767
768 static int
zvol_update_live_volsize(zvol_state_t * zv,uint64_t volsize)769 zvol_update_live_volsize(zvol_state_t *zv, uint64_t volsize)
770 {
771 uint64_t old_volsize = 0ULL;
772 int error = 0;
773
774 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
775
776 /*
777 * Reinitialize the dump area to the new size. If we
778 * failed to resize the dump area then restore it back to
779 * its original size. We must set the new volsize prior
780 * to calling dumpvp_resize() to ensure that the devices'
781 * size(9P) is not visible by the dump subsystem.
782 */
783 old_volsize = zv->zv_volsize;
784 zvol_size_changed(zv, volsize);
785
786 if (zv->zv_flags & ZVOL_DUMPIFIED) {
787 if ((error = zvol_dumpify(zv)) != 0 ||
788 (error = dumpvp_resize()) != 0) {
789 int dumpify_error;
790
791 (void) zvol_update_volsize(zv->zv_objset, old_volsize);
792 zvol_size_changed(zv, old_volsize);
793 dumpify_error = zvol_dumpify(zv);
794 error = dumpify_error ? dumpify_error : error;
795 }
796 }
797
798 /*
799 * Generate a LUN expansion event.
800 */
801 if (error == 0) {
802 sysevent_id_t eid;
803 nvlist_t *attr;
804 char *physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
805
806 (void) snprintf(physpath, MAXPATHLEN, "%s%u", ZVOL_PSEUDO_DEV,
807 zv->zv_minor);
808
809 VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0);
810 VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0);
811
812 (void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS,
813 ESC_DEV_DLE, attr, &eid, DDI_SLEEP);
814
815 nvlist_free(attr);
816 kmem_free(physpath, MAXPATHLEN);
817 }
818 return (error);
819 }
820
821 int
zvol_set_volsize(const char * name,uint64_t volsize)822 zvol_set_volsize(const char *name, uint64_t volsize)
823 {
824 zvol_state_t *zv = NULL;
825 objset_t *os;
826 int error;
827 dmu_object_info_t doi;
828 uint64_t readonly;
829 boolean_t owned = B_FALSE;
830
831 error = dsl_prop_get_integer(name,
832 zfs_prop_to_name(ZFS_PROP_READONLY), &readonly, NULL);
833 if (error != 0)
834 return (error);
835 if (readonly)
836 return (SET_ERROR(EROFS));
837
838 mutex_enter(&zfsdev_state_lock);
839 zv = zvol_minor_lookup(name);
840
841 if (zv == NULL || zv->zv_objset == NULL) {
842 if ((error = dmu_objset_own(name, DMU_OST_ZVOL, B_FALSE,
843 FTAG, &os)) != 0) {
844 mutex_exit(&zfsdev_state_lock);
845 return (error);
846 }
847 owned = B_TRUE;
848 if (zv != NULL)
849 zv->zv_objset = os;
850 } else {
851 os = zv->zv_objset;
852 }
853
854 if ((error = dmu_object_info(os, ZVOL_OBJ, &doi)) != 0 ||
855 (error = zvol_check_volsize(volsize, doi.doi_data_block_size)) != 0)
856 goto out;
857
858 error = zvol_update_volsize(os, volsize);
859
860 if (error == 0 && zv != NULL)
861 error = zvol_update_live_volsize(zv, volsize);
862 out:
863 if (owned) {
864 dmu_objset_disown(os, FTAG);
865 if (zv != NULL)
866 zv->zv_objset = NULL;
867 }
868 mutex_exit(&zfsdev_state_lock);
869 return (error);
870 }
871
872 /*ARGSUSED*/
873 int
zvol_open(dev_t * devp,int flag,int otyp,cred_t * cr)874 zvol_open(dev_t *devp, int flag, int otyp, cred_t *cr)
875 {
876 zvol_state_t *zv;
877 int err = 0;
878
879 mutex_enter(&zfsdev_state_lock);
880
881 zv = zfsdev_get_soft_state(getminor(*devp), ZSST_ZVOL);
882 if (zv == NULL) {
883 mutex_exit(&zfsdev_state_lock);
884 return (SET_ERROR(ENXIO));
885 }
886
887 if (zv->zv_total_opens == 0)
888 err = zvol_first_open(zv);
889 if (err) {
890 mutex_exit(&zfsdev_state_lock);
891 return (err);
892 }
893 if ((flag & FWRITE) && (zv->zv_flags & ZVOL_RDONLY)) {
894 err = SET_ERROR(EROFS);
895 goto out;
896 }
897 if (zv->zv_flags & ZVOL_EXCL) {
898 err = SET_ERROR(EBUSY);
899 goto out;
900 }
901 if (flag & FEXCL) {
902 if (zv->zv_total_opens != 0) {
903 err = SET_ERROR(EBUSY);
904 goto out;
905 }
906 zv->zv_flags |= ZVOL_EXCL;
907 }
908
909 if (zv->zv_open_count[otyp] == 0 || otyp == OTYP_LYR) {
910 zv->zv_open_count[otyp]++;
911 zv->zv_total_opens++;
912 }
913 mutex_exit(&zfsdev_state_lock);
914
915 return (err);
916 out:
917 if (zv->zv_total_opens == 0)
918 zvol_last_close(zv);
919 mutex_exit(&zfsdev_state_lock);
920 return (err);
921 }
922
923 /*ARGSUSED*/
924 int
zvol_close(dev_t dev,int flag,int otyp,cred_t * cr)925 zvol_close(dev_t dev, int flag, int otyp, cred_t *cr)
926 {
927 minor_t minor = getminor(dev);
928 zvol_state_t *zv;
929 int error = 0;
930
931 mutex_enter(&zfsdev_state_lock);
932
933 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
934 if (zv == NULL) {
935 mutex_exit(&zfsdev_state_lock);
936 return (SET_ERROR(ENXIO));
937 }
938
939 if (zv->zv_flags & ZVOL_EXCL) {
940 ASSERT(zv->zv_total_opens == 1);
941 zv->zv_flags &= ~ZVOL_EXCL;
942 }
943
944 /*
945 * If the open count is zero, this is a spurious close.
946 * That indicates a bug in the kernel / DDI framework.
947 */
948 ASSERT(zv->zv_open_count[otyp] != 0);
949 ASSERT(zv->zv_total_opens != 0);
950
951 /*
952 * You may get multiple opens, but only one close.
953 */
954 zv->zv_open_count[otyp]--;
955 zv->zv_total_opens--;
956
957 if (zv->zv_total_opens == 0)
958 zvol_last_close(zv);
959
960 mutex_exit(&zfsdev_state_lock);
961 return (error);
962 }
963
964 static void
zvol_get_done(zgd_t * zgd,int error)965 zvol_get_done(zgd_t *zgd, int error)
966 {
967 if (zgd->zgd_db)
968 dmu_buf_rele(zgd->zgd_db, zgd);
969
970 zfs_range_unlock(zgd->zgd_rl);
971
972 if (error == 0 && zgd->zgd_bp)
973 zil_add_block(zgd->zgd_zilog, zgd->zgd_bp);
974
975 kmem_free(zgd, sizeof (zgd_t));
976 }
977
978 /*
979 * Get data to generate a TX_WRITE intent log record.
980 */
981 static int
zvol_get_data(void * arg,lr_write_t * lr,char * buf,zio_t * zio)982 zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
983 {
984 zvol_state_t *zv = arg;
985 objset_t *os = zv->zv_objset;
986 uint64_t object = ZVOL_OBJ;
987 uint64_t offset = lr->lr_offset;
988 uint64_t size = lr->lr_length; /* length of user data */
989 blkptr_t *bp = &lr->lr_blkptr;
990 dmu_buf_t *db;
991 zgd_t *zgd;
992 int error;
993
994 ASSERT(zio != NULL);
995 ASSERT(size != 0);
996
997 zgd = kmem_zalloc(sizeof (zgd_t), KM_SLEEP);
998 zgd->zgd_zilog = zv->zv_zilog;
999 zgd->zgd_rl = zfs_range_lock(&zv->zv_znode, offset, size, RL_READER);
1000
1001 /*
1002 * Write records come in two flavors: immediate and indirect.
1003 * For small writes it's cheaper to store the data with the
1004 * log record (immediate); for large writes it's cheaper to
1005 * sync the data and get a pointer to it (indirect) so that
1006 * we don't have to write the data twice.
1007 */
1008 if (buf != NULL) { /* immediate write */
1009 error = dmu_read(os, object, offset, size, buf,
1010 DMU_READ_NO_PREFETCH);
1011 } else {
1012 size = zv->zv_volblocksize;
1013 offset = P2ALIGN(offset, size);
1014 error = dmu_buf_hold(os, object, offset, zgd, &db,
1015 DMU_READ_NO_PREFETCH);
1016 if (error == 0) {
1017 blkptr_t *obp = dmu_buf_get_blkptr(db);
1018 if (obp) {
1019 ASSERT(BP_IS_HOLE(bp));
1020 *bp = *obp;
1021 }
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
zvol_log_write(zvol_state_t * zv,dmu_tx_t * tx,offset_t off,ssize_t resid,boolean_t sync)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 boolean_t slogging;
1057 ssize_t immediate_write_sz;
1058
1059 if (zil_replaying(zilog, tx))
1060 return;
1061
1062 immediate_write_sz = (zilog->zl_logbias == ZFS_LOGBIAS_THROUGHPUT)
1063 ? 0 : zvol_immediate_write_sz;
1064
1065 slogging = spa_has_slogs(zilog->zl_spa) &&
1066 (zilog->zl_logbias == ZFS_LOGBIAS_LATENCY);
1067
1068 while (resid) {
1069 itx_t *itx;
1070 lr_write_t *lr;
1071 ssize_t len;
1072 itx_wr_state_t write_state;
1073
1074 /*
1075 * Unlike zfs_log_write() we can be called with
1076 * upto DMU_MAX_ACCESS/2 (5MB) writes.
1077 */
1078 if (blocksize > immediate_write_sz && !slogging &&
1079 resid >= blocksize && off % blocksize == 0) {
1080 write_state = WR_INDIRECT; /* uses dmu_sync */
1081 len = blocksize;
1082 } else if (sync) {
1083 write_state = WR_COPIED;
1084 len = MIN(ZIL_MAX_LOG_DATA, resid);
1085 } else {
1086 write_state = WR_NEED_COPY;
1087 len = MIN(ZIL_MAX_LOG_DATA, resid);
1088 }
1089
1090 itx = zil_itx_create(TX_WRITE, sizeof (*lr) +
1091 (write_state == WR_COPIED ? len : 0));
1092 lr = (lr_write_t *)&itx->itx_lr;
1093 if (write_state == WR_COPIED && dmu_read(zv->zv_objset,
1094 ZVOL_OBJ, off, len, lr + 1, DMU_READ_NO_PREFETCH) != 0) {
1095 zil_itx_destroy(itx);
1096 itx = zil_itx_create(TX_WRITE, sizeof (*lr));
1097 lr = (lr_write_t *)&itx->itx_lr;
1098 write_state = WR_NEED_COPY;
1099 }
1100
1101 itx->itx_wr_state = write_state;
1102 if (write_state == WR_NEED_COPY)
1103 itx->itx_sod += len;
1104 lr->lr_foid = ZVOL_OBJ;
1105 lr->lr_offset = off;
1106 lr->lr_length = len;
1107 lr->lr_blkoff = 0;
1108 BP_ZERO(&lr->lr_blkptr);
1109
1110 itx->itx_private = zv;
1111 itx->itx_sync = sync;
1112
1113 zil_itx_assign(zilog, itx, tx);
1114
1115 rw_enter(&rz_zev_rwlock, RW_READER);
1116 if (rz_zev_callbacks && rz_zev_callbacks->rz_zev_zvol_write)
1117 rz_zev_callbacks->rz_zev_zvol_write(zv->zv_name,
1118 zv->zv_objset, tx, off, len);
1119 rw_exit(&rz_zev_rwlock);
1120
1121 off += len;
1122 resid -= len;
1123 }
1124 }
1125
1126 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)1127 zvol_dumpio_vdev(vdev_t *vd, void *addr, uint64_t offset, uint64_t origoffset,
1128 uint64_t size, boolean_t doread, boolean_t isdump)
1129 {
1130 vdev_disk_t *dvd;
1131 int c;
1132 int numerrors = 0;
1133
1134 if (vd->vdev_ops == &vdev_mirror_ops ||
1135 vd->vdev_ops == &vdev_replacing_ops ||
1136 vd->vdev_ops == &vdev_spare_ops) {
1137 for (c = 0; c < vd->vdev_children; c++) {
1138 int err = zvol_dumpio_vdev(vd->vdev_child[c],
1139 addr, offset, origoffset, size, doread, isdump);
1140 if (err != 0) {
1141 numerrors++;
1142 } else if (doread) {
1143 break;
1144 }
1145 }
1146 }
1147
1148 if (!vd->vdev_ops->vdev_op_leaf && vd->vdev_ops != &vdev_raidz_ops)
1149 return (numerrors < vd->vdev_children ? 0 : EIO);
1150
1151 if (doread && !vdev_readable(vd))
1152 return (SET_ERROR(EIO));
1153 else if (!doread && !vdev_writeable(vd))
1154 return (SET_ERROR(EIO));
1155
1156 if (vd->vdev_ops == &vdev_raidz_ops) {
1157 return (vdev_raidz_physio(vd,
1158 addr, size, offset, origoffset, doread, isdump));
1159 }
1160
1161 offset += VDEV_LABEL_START_SIZE;
1162
1163 if (ddi_in_panic() || isdump) {
1164 ASSERT(!doread);
1165 if (doread)
1166 return (SET_ERROR(EIO));
1167 dvd = vd->vdev_tsd;
1168 ASSERT3P(dvd, !=, NULL);
1169 return (ldi_dump(dvd->vd_lh, addr, lbtodb(offset),
1170 lbtodb(size)));
1171 } else {
1172 dvd = vd->vdev_tsd;
1173 ASSERT3P(dvd, !=, NULL);
1174 return (vdev_disk_ldi_physio(dvd->vd_lh, addr, size,
1175 offset, doread ? B_READ : B_WRITE));
1176 }
1177 }
1178
1179 static int
zvol_dumpio(zvol_state_t * zv,void * addr,uint64_t offset,uint64_t size,boolean_t doread,boolean_t isdump)1180 zvol_dumpio(zvol_state_t *zv, void *addr, uint64_t offset, uint64_t size,
1181 boolean_t doread, boolean_t isdump)
1182 {
1183 vdev_t *vd;
1184 int error;
1185 zvol_extent_t *ze;
1186 spa_t *spa = dmu_objset_spa(zv->zv_objset);
1187
1188 /* Must be sector aligned, and not stradle a block boundary. */
1189 if (P2PHASE(offset, DEV_BSIZE) || P2PHASE(size, DEV_BSIZE) ||
1190 P2BOUNDARY(offset, size, zv->zv_volblocksize)) {
1191 return (SET_ERROR(EINVAL));
1192 }
1193 ASSERT(size <= zv->zv_volblocksize);
1194
1195 /* Locate the extent this belongs to */
1196 ze = list_head(&zv->zv_extents);
1197 while (offset >= ze->ze_nblks * zv->zv_volblocksize) {
1198 offset -= ze->ze_nblks * zv->zv_volblocksize;
1199 ze = list_next(&zv->zv_extents, ze);
1200 }
1201
1202 if (ze == NULL)
1203 return (SET_ERROR(EINVAL));
1204
1205 if (!ddi_in_panic())
1206 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
1207
1208 vd = vdev_lookup_top(spa, DVA_GET_VDEV(&ze->ze_dva));
1209 offset += DVA_GET_OFFSET(&ze->ze_dva);
1210 error = zvol_dumpio_vdev(vd, addr, offset, DVA_GET_OFFSET(&ze->ze_dva),
1211 size, doread, isdump);
1212
1213 if (!ddi_in_panic())
1214 spa_config_exit(spa, SCL_STATE, FTAG);
1215
1216 return (error);
1217 }
1218
1219 int
zvol_strategy(buf_t * bp)1220 zvol_strategy(buf_t *bp)
1221 {
1222 zfs_soft_state_t *zs = NULL;
1223 zvol_state_t *zv;
1224 uint64_t off, volsize;
1225 size_t resid;
1226 char *addr;
1227 objset_t *os;
1228 rl_t *rl;
1229 int error = 0;
1230 boolean_t doread = bp->b_flags & B_READ;
1231 boolean_t is_dumpified;
1232 boolean_t sync;
1233
1234 if (getminor(bp->b_edev) == 0) {
1235 error = SET_ERROR(EINVAL);
1236 } else {
1237 zs = ddi_get_soft_state(zfsdev_state, getminor(bp->b_edev));
1238 if (zs == NULL)
1239 error = SET_ERROR(ENXIO);
1240 else if (zs->zss_type != ZSST_ZVOL)
1241 error = SET_ERROR(EINVAL);
1242 }
1243
1244 if (error) {
1245 bioerror(bp, error);
1246 biodone(bp);
1247 return (0);
1248 }
1249
1250 zv = zs->zss_data;
1251
1252 if (!(bp->b_flags & B_READ) && (zv->zv_flags & ZVOL_RDONLY)) {
1253 bioerror(bp, EROFS);
1254 biodone(bp);
1255 return (0);
1256 }
1257
1258 off = ldbtob(bp->b_blkno);
1259 volsize = zv->zv_volsize;
1260
1261 os = zv->zv_objset;
1262 ASSERT(os != NULL);
1263
1264 bp_mapin(bp);
1265 addr = bp->b_un.b_addr;
1266 resid = bp->b_bcount;
1267
1268 if (resid > 0 && (off < 0 || off >= volsize)) {
1269 bioerror(bp, EIO);
1270 biodone(bp);
1271 return (0);
1272 }
1273
1274 is_dumpified = zv->zv_flags & ZVOL_DUMPIFIED;
1275 sync = ((!(bp->b_flags & B_ASYNC) &&
1276 !(zv->zv_flags & ZVOL_WCE)) ||
1277 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS)) &&
1278 !doread && !is_dumpified;
1279
1280 /*
1281 * There must be no buffer changes when doing a dmu_sync() because
1282 * we can't change the data whilst calculating the checksum.
1283 */
1284 rl = zfs_range_lock(&zv->zv_znode, off, resid,
1285 doread ? RL_READER : RL_WRITER);
1286
1287 while (resid != 0 && off < volsize) {
1288 size_t size = MIN(resid, zvol_maxphys);
1289 if (is_dumpified) {
1290 size = MIN(size, P2END(off, zv->zv_volblocksize) - off);
1291 error = zvol_dumpio(zv, addr, off, size,
1292 doread, B_FALSE);
1293 } else if (doread) {
1294 error = dmu_read(os, ZVOL_OBJ, off, size, addr,
1295 DMU_READ_PREFETCH);
1296 } else {
1297 dmu_tx_t *tx = dmu_tx_create(os);
1298 dmu_tx_hold_write(tx, ZVOL_OBJ, off, size);
1299 error = dmu_tx_assign(tx, TXG_WAIT);
1300 if (error) {
1301 dmu_tx_abort(tx);
1302 } else {
1303 dmu_write(os, ZVOL_OBJ, off, size, addr, tx);
1304 zvol_log_write(zv, tx, off, size, sync);
1305 dmu_tx_commit(tx);
1306 }
1307 }
1308 if (error) {
1309 /* convert checksum errors into IO errors */
1310 if (error == ECKSUM)
1311 error = SET_ERROR(EIO);
1312 break;
1313 }
1314 off += size;
1315 addr += size;
1316 resid -= size;
1317 }
1318 zfs_range_unlock(rl);
1319
1320 if ((bp->b_resid = resid) == bp->b_bcount)
1321 bioerror(bp, off > volsize ? EINVAL : error);
1322
1323 if (sync)
1324 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1325 biodone(bp);
1326
1327 return (0);
1328 }
1329
1330 /*
1331 * Set the buffer count to the zvol maximum transfer.
1332 * Using our own routine instead of the default minphys()
1333 * means that for larger writes we write bigger buffers on X86
1334 * (128K instead of 56K) and flush the disk write cache less often
1335 * (every zvol_maxphys - currently 1MB) instead of minphys (currently
1336 * 56K on X86 and 128K on sparc).
1337 */
1338 void
zvol_minphys(struct buf * bp)1339 zvol_minphys(struct buf *bp)
1340 {
1341 if (bp->b_bcount > zvol_maxphys)
1342 bp->b_bcount = zvol_maxphys;
1343 }
1344
1345 int
zvol_dump(dev_t dev,caddr_t addr,daddr_t blkno,int nblocks)1346 zvol_dump(dev_t dev, caddr_t addr, daddr_t blkno, int nblocks)
1347 {
1348 minor_t minor = getminor(dev);
1349 zvol_state_t *zv;
1350 int error = 0;
1351 uint64_t size;
1352 uint64_t boff;
1353 uint64_t resid;
1354
1355 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1356 if (zv == NULL)
1357 return (SET_ERROR(ENXIO));
1358
1359 if ((zv->zv_flags & ZVOL_DUMPIFIED) == 0)
1360 return (SET_ERROR(EINVAL));
1361
1362 boff = ldbtob(blkno);
1363 resid = ldbtob(nblocks);
1364
1365 VERIFY3U(boff + resid, <=, zv->zv_volsize);
1366
1367 while (resid) {
1368 size = MIN(resid, P2END(boff, zv->zv_volblocksize) - boff);
1369 error = zvol_dumpio(zv, addr, boff, size, B_FALSE, B_TRUE);
1370 if (error)
1371 break;
1372 boff += size;
1373 addr += size;
1374 resid -= size;
1375 }
1376
1377 return (error);
1378 }
1379
1380 /*ARGSUSED*/
1381 int
zvol_read(dev_t dev,uio_t * uio,cred_t * cr)1382 zvol_read(dev_t dev, uio_t *uio, cred_t *cr)
1383 {
1384 minor_t minor = getminor(dev);
1385 zvol_state_t *zv;
1386 uint64_t volsize;
1387 rl_t *rl;
1388 int error = 0;
1389
1390 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1391 if (zv == NULL)
1392 return (SET_ERROR(ENXIO));
1393
1394 volsize = zv->zv_volsize;
1395 if (uio->uio_resid > 0 &&
1396 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize))
1397 return (SET_ERROR(EIO));
1398
1399 if (zv->zv_flags & ZVOL_DUMPIFIED) {
1400 error = physio(zvol_strategy, NULL, dev, B_READ,
1401 zvol_minphys, uio);
1402 return (error);
1403 }
1404
1405 rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid,
1406 RL_READER);
1407 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) {
1408 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1);
1409
1410 /* don't read past the end */
1411 if (bytes > volsize - uio->uio_loffset)
1412 bytes = volsize - uio->uio_loffset;
1413
1414 error = dmu_read_uio(zv->zv_objset, ZVOL_OBJ, uio, bytes);
1415 if (error) {
1416 /* convert checksum errors into IO errors */
1417 if (error == ECKSUM)
1418 error = SET_ERROR(EIO);
1419 break;
1420 }
1421 }
1422 zfs_range_unlock(rl);
1423 return (error);
1424 }
1425
1426 /*ARGSUSED*/
1427 int
zvol_write(dev_t dev,uio_t * uio,cred_t * cr)1428 zvol_write(dev_t dev, uio_t *uio, cred_t *cr)
1429 {
1430 minor_t minor = getminor(dev);
1431 zvol_state_t *zv;
1432 uint64_t volsize;
1433 rl_t *rl;
1434 int error = 0;
1435 boolean_t sync;
1436
1437 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1438 if (zv == NULL)
1439 return (SET_ERROR(ENXIO));
1440
1441 volsize = zv->zv_volsize;
1442 if (uio->uio_resid > 0 &&
1443 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize))
1444 return (SET_ERROR(EIO));
1445
1446 if (zv->zv_flags & ZVOL_DUMPIFIED) {
1447 error = physio(zvol_strategy, NULL, dev, B_WRITE,
1448 zvol_minphys, uio);
1449 return (error);
1450 }
1451
1452 sync = !(zv->zv_flags & ZVOL_WCE) ||
1453 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS);
1454
1455 rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid,
1456 RL_WRITER);
1457 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) {
1458 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1);
1459 uint64_t off = uio->uio_loffset;
1460 dmu_tx_t *tx = dmu_tx_create(zv->zv_objset);
1461
1462 if (bytes > volsize - off) /* don't write past the end */
1463 bytes = volsize - off;
1464
1465 dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes);
1466 error = dmu_tx_assign(tx, TXG_WAIT);
1467 if (error) {
1468 dmu_tx_abort(tx);
1469 break;
1470 }
1471 error = dmu_write_uio_dbuf(zv->zv_dbuf, uio, bytes, tx);
1472 if (error == 0)
1473 zvol_log_write(zv, tx, off, bytes, sync);
1474 dmu_tx_commit(tx);
1475
1476 if (error)
1477 break;
1478 }
1479 zfs_range_unlock(rl);
1480 if (sync)
1481 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1482 return (error);
1483 }
1484
1485 int
zvol_getefi(void * arg,int flag,uint64_t vs,uint8_t bs)1486 zvol_getefi(void *arg, int flag, uint64_t vs, uint8_t bs)
1487 {
1488 struct uuid uuid = EFI_RESERVED;
1489 efi_gpe_t gpe = { 0 };
1490 uint32_t crc;
1491 dk_efi_t efi;
1492 int length;
1493 char *ptr;
1494
1495 if (ddi_copyin(arg, &efi, sizeof (dk_efi_t), flag))
1496 return (SET_ERROR(EFAULT));
1497 ptr = (char *)(uintptr_t)efi.dki_data_64;
1498 length = efi.dki_length;
1499 /*
1500 * Some clients may attempt to request a PMBR for the
1501 * zvol. Currently this interface will return EINVAL to
1502 * such requests. These requests could be supported by
1503 * adding a check for lba == 0 and consing up an appropriate
1504 * PMBR.
1505 */
1506 if (efi.dki_lba < 1 || efi.dki_lba > 2 || length <= 0)
1507 return (SET_ERROR(EINVAL));
1508
1509 gpe.efi_gpe_StartingLBA = LE_64(34ULL);
1510 gpe.efi_gpe_EndingLBA = LE_64((vs >> bs) - 1);
1511 UUID_LE_CONVERT(gpe.efi_gpe_PartitionTypeGUID, uuid);
1512
1513 if (efi.dki_lba == 1) {
1514 efi_gpt_t gpt = { 0 };
1515
1516 gpt.efi_gpt_Signature = LE_64(EFI_SIGNATURE);
1517 gpt.efi_gpt_Revision = LE_32(EFI_VERSION_CURRENT);
1518 gpt.efi_gpt_HeaderSize = LE_32(sizeof (gpt));
1519 gpt.efi_gpt_MyLBA = LE_64(1ULL);
1520 gpt.efi_gpt_FirstUsableLBA = LE_64(34ULL);
1521 gpt.efi_gpt_LastUsableLBA = LE_64((vs >> bs) - 1);
1522 gpt.efi_gpt_PartitionEntryLBA = LE_64(2ULL);
1523 gpt.efi_gpt_NumberOfPartitionEntries = LE_32(1);
1524 gpt.efi_gpt_SizeOfPartitionEntry =
1525 LE_32(sizeof (efi_gpe_t));
1526 CRC32(crc, &gpe, sizeof (gpe), -1U, crc32_table);
1527 gpt.efi_gpt_PartitionEntryArrayCRC32 = LE_32(~crc);
1528 CRC32(crc, &gpt, sizeof (gpt), -1U, crc32_table);
1529 gpt.efi_gpt_HeaderCRC32 = LE_32(~crc);
1530 if (ddi_copyout(&gpt, ptr, MIN(sizeof (gpt), length),
1531 flag))
1532 return (SET_ERROR(EFAULT));
1533 ptr += sizeof (gpt);
1534 length -= sizeof (gpt);
1535 }
1536 if (length > 0 && ddi_copyout(&gpe, ptr, MIN(sizeof (gpe),
1537 length), flag))
1538 return (SET_ERROR(EFAULT));
1539 return (0);
1540 }
1541
1542 /*
1543 * BEGIN entry points to allow external callers access to the volume.
1544 */
1545 /*
1546 * Return the volume parameters needed for access from an external caller.
1547 * These values are invariant as long as the volume is held open.
1548 */
1549 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)1550 zvol_get_volume_params(minor_t minor, uint64_t *blksize,
1551 uint64_t *max_xfer_len, void **minor_hdl, void **objset_hdl, void **zil_hdl,
1552 void **rl_hdl, void **bonus_hdl)
1553 {
1554 zvol_state_t *zv;
1555
1556 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL);
1557 if (zv == NULL)
1558 return (SET_ERROR(ENXIO));
1559 if (zv->zv_flags & ZVOL_DUMPIFIED)
1560 return (SET_ERROR(ENXIO));
1561
1562 ASSERT(blksize && max_xfer_len && minor_hdl &&
1563 objset_hdl && zil_hdl && rl_hdl && bonus_hdl);
1564
1565 *blksize = zv->zv_volblocksize;
1566 *max_xfer_len = (uint64_t)zvol_maxphys;
1567 *minor_hdl = zv;
1568 *objset_hdl = zv->zv_objset;
1569 *zil_hdl = zv->zv_zilog;
1570 *rl_hdl = &zv->zv_znode;
1571 *bonus_hdl = zv->zv_dbuf;
1572 return (0);
1573 }
1574
1575 /*
1576 * Return the current volume size to an external caller.
1577 * The size can change while the volume is open.
1578 */
1579 uint64_t
zvol_get_volume_size(void * minor_hdl)1580 zvol_get_volume_size(void *minor_hdl)
1581 {
1582 zvol_state_t *zv = minor_hdl;
1583
1584 return (zv->zv_volsize);
1585 }
1586
1587 /*
1588 * Return the current WCE setting to an external caller.
1589 * The WCE setting can change while the volume is open.
1590 */
1591 int
zvol_get_volume_wce(void * minor_hdl)1592 zvol_get_volume_wce(void *minor_hdl)
1593 {
1594 zvol_state_t *zv = minor_hdl;
1595
1596 return ((zv->zv_flags & ZVOL_WCE) ? 1 : 0);
1597 }
1598
1599 /*
1600 * Entry point for external callers to zvol_log_write
1601 */
1602 void
zvol_log_write_minor(void * minor_hdl,dmu_tx_t * tx,offset_t off,ssize_t resid,boolean_t sync)1603 zvol_log_write_minor(void *minor_hdl, dmu_tx_t *tx, offset_t off, ssize_t resid,
1604 boolean_t sync)
1605 {
1606 zvol_state_t *zv = minor_hdl;
1607
1608 zvol_log_write(zv, tx, off, resid, sync);
1609 }
1610 /*
1611 * END entry points to allow external callers access to the volume.
1612 */
1613
1614 /*
1615 * Log a DKIOCFREE/free-long-range to the ZIL with TX_TRUNCATE.
1616 */
1617 static void
zvol_log_truncate(zvol_state_t * zv,dmu_tx_t * tx,uint64_t off,uint64_t len,boolean_t sync)1618 zvol_log_truncate(zvol_state_t *zv, dmu_tx_t *tx, uint64_t off, uint64_t len,
1619 boolean_t sync)
1620 {
1621 itx_t *itx;
1622 lr_truncate_t *lr;
1623 zilog_t *zilog = zv->zv_zilog;
1624
1625 if (zil_replaying(zilog, tx))
1626 return;
1627
1628 itx = zil_itx_create(TX_TRUNCATE, sizeof (*lr));
1629 lr = (lr_truncate_t *)&itx->itx_lr;
1630 lr->lr_foid = ZVOL_OBJ;
1631 lr->lr_offset = off;
1632 lr->lr_length = len;
1633
1634 itx->itx_sync = sync;
1635 zil_itx_assign(zilog, itx, tx);
1636
1637 rw_enter(&rz_zev_rwlock, RW_READER);
1638 if (rz_zev_callbacks && rz_zev_callbacks->rz_zev_zvol_truncate)
1639 rz_zev_callbacks->rz_zev_zvol_truncate(zv->zv_name,
1640 zv->zv_objset, tx, off, len);
1641 rw_exit(&rz_zev_rwlock);
1642 }
1643
1644 /*
1645 * Dirtbag ioctls to support mkfs(1M) for UFS filesystems. See dkio(7I).
1646 * Also a dirtbag dkio ioctl for unmap/free-block functionality.
1647 */
1648 /*ARGSUSED*/
1649 int
zvol_ioctl(dev_t dev,int cmd,intptr_t arg,int flag,cred_t * cr,int * rvalp)1650 zvol_ioctl(dev_t dev, int cmd, intptr_t arg, int flag, cred_t *cr, int *rvalp)
1651 {
1652 zvol_state_t *zv;
1653 struct dk_callback *dkc;
1654 int error = 0;
1655 rl_t *rl;
1656
1657 mutex_enter(&zfsdev_state_lock);
1658
1659 zv = zfsdev_get_soft_state(getminor(dev), ZSST_ZVOL);
1660
1661 if (zv == NULL) {
1662 mutex_exit(&zfsdev_state_lock);
1663 return (SET_ERROR(ENXIO));
1664 }
1665 ASSERT(zv->zv_total_opens > 0);
1666
1667 switch (cmd) {
1668
1669 case DKIOCINFO:
1670 {
1671 struct dk_cinfo dki;
1672
1673 bzero(&dki, sizeof (dki));
1674 (void) strcpy(dki.dki_cname, "zvol");
1675 (void) strcpy(dki.dki_dname, "zvol");
1676 dki.dki_ctype = DKC_UNKNOWN;
1677 dki.dki_unit = getminor(dev);
1678 dki.dki_maxtransfer =
1679 1 << (SPA_OLD_MAXBLOCKSHIFT - zv->zv_min_bs);
1680 mutex_exit(&zfsdev_state_lock);
1681 if (ddi_copyout(&dki, (void *)arg, sizeof (dki), flag))
1682 error = SET_ERROR(EFAULT);
1683 return (error);
1684 }
1685
1686 case DKIOCGMEDIAINFO:
1687 {
1688 struct dk_minfo dkm;
1689
1690 bzero(&dkm, sizeof (dkm));
1691 dkm.dki_lbsize = 1U << zv->zv_min_bs;
1692 dkm.dki_capacity = zv->zv_volsize >> zv->zv_min_bs;
1693 dkm.dki_media_type = DK_UNKNOWN;
1694 mutex_exit(&zfsdev_state_lock);
1695 if (ddi_copyout(&dkm, (void *)arg, sizeof (dkm), flag))
1696 error = SET_ERROR(EFAULT);
1697 return (error);
1698 }
1699
1700 case DKIOCGMEDIAINFOEXT:
1701 {
1702 struct dk_minfo_ext dkmext;
1703
1704 bzero(&dkmext, sizeof (dkmext));
1705 dkmext.dki_lbsize = 1U << zv->zv_min_bs;
1706 dkmext.dki_pbsize = zv->zv_volblocksize;
1707 dkmext.dki_capacity = zv->zv_volsize >> zv->zv_min_bs;
1708 dkmext.dki_media_type = DK_UNKNOWN;
1709 mutex_exit(&zfsdev_state_lock);
1710 if (ddi_copyout(&dkmext, (void *)arg, sizeof (dkmext), flag))
1711 error = SET_ERROR(EFAULT);
1712 return (error);
1713 }
1714
1715 case DKIOCGETEFI:
1716 {
1717 uint64_t vs = zv->zv_volsize;
1718 uint8_t bs = zv->zv_min_bs;
1719
1720 mutex_exit(&zfsdev_state_lock);
1721 error = zvol_getefi((void *)arg, flag, vs, bs);
1722 return (error);
1723 }
1724
1725 case DKIOCFLUSHWRITECACHE:
1726 dkc = (struct dk_callback *)arg;
1727 mutex_exit(&zfsdev_state_lock);
1728 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1729 if ((flag & FKIOCTL) && dkc != NULL && dkc->dkc_callback) {
1730 (*dkc->dkc_callback)(dkc->dkc_cookie, error);
1731 error = 0;
1732 }
1733 return (error);
1734
1735 case DKIOCGETWCE:
1736 {
1737 int wce = (zv->zv_flags & ZVOL_WCE) ? 1 : 0;
1738 if (ddi_copyout(&wce, (void *)arg, sizeof (int),
1739 flag))
1740 error = SET_ERROR(EFAULT);
1741 break;
1742 }
1743 case DKIOCSETWCE:
1744 {
1745 int wce;
1746 if (ddi_copyin((void *)arg, &wce, sizeof (int),
1747 flag)) {
1748 error = SET_ERROR(EFAULT);
1749 break;
1750 }
1751 if (wce) {
1752 zv->zv_flags |= ZVOL_WCE;
1753 mutex_exit(&zfsdev_state_lock);
1754 } else {
1755 zv->zv_flags &= ~ZVOL_WCE;
1756 mutex_exit(&zfsdev_state_lock);
1757 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1758 }
1759 return (0);
1760 }
1761
1762 case DKIOCGGEOM:
1763 case DKIOCGVTOC:
1764 /*
1765 * commands using these (like prtvtoc) expect ENOTSUP
1766 * since we're emulating an EFI label
1767 */
1768 error = SET_ERROR(ENOTSUP);
1769 break;
1770
1771 case DKIOCDUMPINIT:
1772 rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize,
1773 RL_WRITER);
1774 error = zvol_dumpify(zv);
1775 zfs_range_unlock(rl);
1776 break;
1777
1778 case DKIOCDUMPFINI:
1779 if (!(zv->zv_flags & ZVOL_DUMPIFIED))
1780 break;
1781 rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize,
1782 RL_WRITER);
1783 error = zvol_dump_fini(zv);
1784 zfs_range_unlock(rl);
1785 break;
1786
1787 case DKIOCFREE:
1788 {
1789 dkioc_free_t df;
1790 dmu_tx_t *tx;
1791
1792 if (!zvol_unmap_enabled)
1793 break;
1794
1795 if (ddi_copyin((void *)arg, &df, sizeof (df), flag)) {
1796 error = SET_ERROR(EFAULT);
1797 break;
1798 }
1799
1800 /*
1801 * Apply Postel's Law to length-checking. If they overshoot,
1802 * just blank out until the end, if there's a need to blank
1803 * out anything.
1804 */
1805 if (df.df_start >= zv->zv_volsize)
1806 break; /* No need to do anything... */
1807
1808 mutex_exit(&zfsdev_state_lock);
1809
1810 rl = zfs_range_lock(&zv->zv_znode, df.df_start, df.df_length,
1811 RL_WRITER);
1812 tx = dmu_tx_create(zv->zv_objset);
1813 dmu_tx_mark_netfree(tx);
1814 error = dmu_tx_assign(tx, TXG_WAIT);
1815 if (error != 0) {
1816 dmu_tx_abort(tx);
1817 } else {
1818 zvol_log_truncate(zv, tx, df.df_start,
1819 df.df_length, B_TRUE);
1820 dmu_tx_commit(tx);
1821 error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ,
1822 df.df_start, df.df_length);
1823 }
1824
1825 zfs_range_unlock(rl);
1826
1827 if (error == 0) {
1828 /*
1829 * If the write-cache is disabled or 'sync' property
1830 * is set to 'always' then treat this as a synchronous
1831 * operation (i.e. commit to zil).
1832 */
1833 if (!(zv->zv_flags & ZVOL_WCE) ||
1834 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS))
1835 zil_commit(zv->zv_zilog, ZVOL_OBJ);
1836
1837 /*
1838 * If the caller really wants synchronous writes, and
1839 * can't wait for them, don't return until the write
1840 * is done.
1841 */
1842 if (df.df_flags & DF_WAIT_SYNC) {
1843 txg_wait_synced(
1844 dmu_objset_pool(zv->zv_objset), 0);
1845 }
1846 }
1847 return (error);
1848 }
1849
1850 default:
1851 error = SET_ERROR(ENOTTY);
1852 break;
1853
1854 }
1855 mutex_exit(&zfsdev_state_lock);
1856 return (error);
1857 }
1858
1859 int
zvol_busy(void)1860 zvol_busy(void)
1861 {
1862 return (zvol_minors != 0);
1863 }
1864
1865 void
zvol_init(void)1866 zvol_init(void)
1867 {
1868 VERIFY(ddi_soft_state_init(&zfsdev_state, sizeof (zfs_soft_state_t),
1869 1) == 0);
1870 mutex_init(&zfsdev_state_lock, NULL, MUTEX_DEFAULT, NULL);
1871 }
1872
1873 void
zvol_fini(void)1874 zvol_fini(void)
1875 {
1876 mutex_destroy(&zfsdev_state_lock);
1877 ddi_soft_state_fini(&zfsdev_state);
1878 }
1879
1880 /*ARGSUSED*/
1881 static int
zfs_mvdev_dump_feature_check(void * arg,dmu_tx_t * tx)1882 zfs_mvdev_dump_feature_check(void *arg, dmu_tx_t *tx)
1883 {
1884 spa_t *spa = dmu_tx_pool(tx)->dp_spa;
1885
1886 if (spa_feature_is_active(spa, SPA_FEATURE_MULTI_VDEV_CRASH_DUMP))
1887 return (1);
1888 return (0);
1889 }
1890
1891 /*ARGSUSED*/
1892 static void
zfs_mvdev_dump_activate_feature_sync(void * arg,dmu_tx_t * tx)1893 zfs_mvdev_dump_activate_feature_sync(void *arg, dmu_tx_t *tx)
1894 {
1895 spa_t *spa = dmu_tx_pool(tx)->dp_spa;
1896
1897 spa_feature_incr(spa, SPA_FEATURE_MULTI_VDEV_CRASH_DUMP, tx);
1898 }
1899
1900 static int
zvol_dump_init(zvol_state_t * zv,boolean_t resize)1901 zvol_dump_init(zvol_state_t *zv, boolean_t resize)
1902 {
1903 dmu_tx_t *tx;
1904 int error;
1905 objset_t *os = zv->zv_objset;
1906 spa_t *spa = dmu_objset_spa(os);
1907 vdev_t *vd = spa->spa_root_vdev;
1908 nvlist_t *nv = NULL;
1909 uint64_t version = spa_version(spa);
1910 uint64_t checksum, compress, refresrv, vbs, dedup;
1911
1912 ASSERT(MUTEX_HELD(&zfsdev_state_lock));
1913 ASSERT(vd->vdev_ops == &vdev_root_ops);
1914
1915 error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, 0,
1916 DMU_OBJECT_END);
1917 if (error != 0)
1918 return (error);
1919 /* wait for dmu_free_long_range to actually free the blocks */
1920 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
1921
1922 /*
1923 * If the pool on which the dump device is being initialized has more
1924 * than one child vdev, check that the MULTI_VDEV_CRASH_DUMP feature is
1925 * enabled. If so, bump that feature's counter to indicate that the
1926 * feature is active. We also check the vdev type to handle the
1927 * following case:
1928 * # zpool create test raidz disk1 disk2 disk3
1929 * Now have spa_root_vdev->vdev_children == 1 (the raidz vdev),
1930 * the raidz vdev itself has 3 children.
1931 */
1932 if (vd->vdev_children > 1 || vd->vdev_ops == &vdev_raidz_ops) {
1933 if (!spa_feature_is_enabled(spa,
1934 SPA_FEATURE_MULTI_VDEV_CRASH_DUMP))
1935 return (SET_ERROR(ENOTSUP));
1936 (void) dsl_sync_task(spa_name(spa),
1937 zfs_mvdev_dump_feature_check,
1938 zfs_mvdev_dump_activate_feature_sync, NULL,
1939 2, ZFS_SPACE_CHECK_RESERVED);
1940 }
1941
1942 if (!resize) {
1943 error = dsl_prop_get_integer(zv->zv_name,
1944 zfs_prop_to_name(ZFS_PROP_COMPRESSION), &compress, NULL);
1945 if (error == 0) {
1946 error = dsl_prop_get_integer(zv->zv_name,
1947 zfs_prop_to_name(ZFS_PROP_CHECKSUM), &checksum,
1948 NULL);
1949 }
1950 if (error == 0) {
1951 error = dsl_prop_get_integer(zv->zv_name,
1952 zfs_prop_to_name(ZFS_PROP_REFRESERVATION),
1953 &refresrv, NULL);
1954 }
1955 if (error == 0) {
1956 error = dsl_prop_get_integer(zv->zv_name,
1957 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &vbs,
1958 NULL);
1959 }
1960 if (version >= SPA_VERSION_DEDUP && error == 0) {
1961 error = dsl_prop_get_integer(zv->zv_name,
1962 zfs_prop_to_name(ZFS_PROP_DEDUP), &dedup, NULL);
1963 }
1964 }
1965 if (error != 0)
1966 return (error);
1967
1968 tx = dmu_tx_create(os);
1969 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
1970 dmu_tx_hold_bonus(tx, ZVOL_OBJ);
1971 error = dmu_tx_assign(tx, TXG_WAIT);
1972 if (error != 0) {
1973 dmu_tx_abort(tx);
1974 return (error);
1975 }
1976
1977 /*
1978 * If we are resizing the dump device then we only need to
1979 * update the refreservation to match the newly updated
1980 * zvolsize. Otherwise, we save off the original state of the
1981 * zvol so that we can restore them if the zvol is ever undumpified.
1982 */
1983 if (resize) {
1984 error = zap_update(os, ZVOL_ZAP_OBJ,
1985 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1,
1986 &zv->zv_volsize, tx);
1987 } else {
1988 error = zap_update(os, ZVOL_ZAP_OBJ,
1989 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1,
1990 &compress, tx);
1991 if (error == 0) {
1992 error = zap_update(os, ZVOL_ZAP_OBJ,
1993 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1,
1994 &checksum, tx);
1995 }
1996 if (error == 0) {
1997 error = zap_update(os, ZVOL_ZAP_OBJ,
1998 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1,
1999 &refresrv, tx);
2000 }
2001 if (error == 0) {
2002 error = zap_update(os, ZVOL_ZAP_OBJ,
2003 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1,
2004 &vbs, tx);
2005 }
2006 if (error == 0) {
2007 error = dmu_object_set_blocksize(
2008 os, ZVOL_OBJ, SPA_OLD_MAXBLOCKSIZE, 0, tx);
2009 }
2010 if (version >= SPA_VERSION_DEDUP && error == 0) {
2011 error = zap_update(os, ZVOL_ZAP_OBJ,
2012 zfs_prop_to_name(ZFS_PROP_DEDUP), 8, 1,
2013 &dedup, tx);
2014 }
2015 if (error == 0)
2016 zv->zv_volblocksize = SPA_OLD_MAXBLOCKSIZE;
2017 }
2018 dmu_tx_commit(tx);
2019
2020 /*
2021 * We only need update the zvol's property if we are initializing
2022 * the dump area for the first time.
2023 */
2024 if (error == 0 && !resize) {
2025 /*
2026 * If MULTI_VDEV_CRASH_DUMP is active, use the NOPARITY checksum
2027 * function. Otherwise, use the old default -- OFF.
2028 */
2029 checksum = spa_feature_is_active(spa,
2030 SPA_FEATURE_MULTI_VDEV_CRASH_DUMP) ? ZIO_CHECKSUM_NOPARITY :
2031 ZIO_CHECKSUM_OFF;
2032
2033 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2034 VERIFY(nvlist_add_uint64(nv,
2035 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 0) == 0);
2036 VERIFY(nvlist_add_uint64(nv,
2037 zfs_prop_to_name(ZFS_PROP_COMPRESSION),
2038 ZIO_COMPRESS_OFF) == 0);
2039 VERIFY(nvlist_add_uint64(nv,
2040 zfs_prop_to_name(ZFS_PROP_CHECKSUM),
2041 checksum) == 0);
2042 if (version >= SPA_VERSION_DEDUP) {
2043 VERIFY(nvlist_add_uint64(nv,
2044 zfs_prop_to_name(ZFS_PROP_DEDUP),
2045 ZIO_CHECKSUM_OFF) == 0);
2046 }
2047
2048 error = zfs_set_prop_nvlist(zv->zv_name, ZPROP_SRC_LOCAL,
2049 nv, NULL);
2050 nvlist_free(nv);
2051 }
2052
2053 /* Allocate the space for the dump */
2054 if (error == 0)
2055 error = zvol_prealloc(zv);
2056 return (error);
2057 }
2058
2059 static int
zvol_dumpify(zvol_state_t * zv)2060 zvol_dumpify(zvol_state_t *zv)
2061 {
2062 int error = 0;
2063 uint64_t dumpsize = 0;
2064 dmu_tx_t *tx;
2065 objset_t *os = zv->zv_objset;
2066
2067 if (zv->zv_flags & ZVOL_RDONLY)
2068 return (SET_ERROR(EROFS));
2069
2070 if (zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE,
2071 8, 1, &dumpsize) != 0 || dumpsize != zv->zv_volsize) {
2072 boolean_t resize = (dumpsize > 0);
2073
2074 if ((error = zvol_dump_init(zv, resize)) != 0) {
2075 (void) zvol_dump_fini(zv);
2076 return (error);
2077 }
2078 }
2079
2080 /*
2081 * Build up our lba mapping.
2082 */
2083 error = zvol_get_lbas(zv);
2084 if (error) {
2085 (void) zvol_dump_fini(zv);
2086 return (error);
2087 }
2088
2089 tx = dmu_tx_create(os);
2090 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
2091 error = dmu_tx_assign(tx, TXG_WAIT);
2092 if (error) {
2093 dmu_tx_abort(tx);
2094 (void) zvol_dump_fini(zv);
2095 return (error);
2096 }
2097
2098 zv->zv_flags |= ZVOL_DUMPIFIED;
2099 error = zap_update(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, 8, 1,
2100 &zv->zv_volsize, tx);
2101 dmu_tx_commit(tx);
2102
2103 if (error) {
2104 (void) zvol_dump_fini(zv);
2105 return (error);
2106 }
2107
2108 txg_wait_synced(dmu_objset_pool(os), 0);
2109 return (0);
2110 }
2111
2112 static int
zvol_dump_fini(zvol_state_t * zv)2113 zvol_dump_fini(zvol_state_t *zv)
2114 {
2115 dmu_tx_t *tx;
2116 objset_t *os = zv->zv_objset;
2117 nvlist_t *nv;
2118 int error = 0;
2119 uint64_t checksum, compress, refresrv, vbs, dedup;
2120 uint64_t version = spa_version(dmu_objset_spa(zv->zv_objset));
2121
2122 /*
2123 * Attempt to restore the zvol back to its pre-dumpified state.
2124 * This is a best-effort attempt as it's possible that not all
2125 * of these properties were initialized during the dumpify process
2126 * (i.e. error during zvol_dump_init).
2127 */
2128
2129 tx = dmu_tx_create(os);
2130 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
2131 error = dmu_tx_assign(tx, TXG_WAIT);
2132 if (error) {
2133 dmu_tx_abort(tx);
2134 return (error);
2135 }
2136 (void) zap_remove(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, tx);
2137 dmu_tx_commit(tx);
2138
2139 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2140 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1, &checksum);
2141 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2142 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1, &compress);
2143 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2144 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, &refresrv);
2145 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2146 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1, &vbs);
2147
2148 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2149 (void) nvlist_add_uint64(nv,
2150 zfs_prop_to_name(ZFS_PROP_CHECKSUM), checksum);
2151 (void) nvlist_add_uint64(nv,
2152 zfs_prop_to_name(ZFS_PROP_COMPRESSION), compress);
2153 (void) nvlist_add_uint64(nv,
2154 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), refresrv);
2155 if (version >= SPA_VERSION_DEDUP &&
2156 zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
2157 zfs_prop_to_name(ZFS_PROP_DEDUP), 8, 1, &dedup) == 0) {
2158 (void) nvlist_add_uint64(nv,
2159 zfs_prop_to_name(ZFS_PROP_DEDUP), dedup);
2160 }
2161 (void) zfs_set_prop_nvlist(zv->zv_name, ZPROP_SRC_LOCAL,
2162 nv, NULL);
2163 nvlist_free(nv);
2164
2165 zvol_free_extents(zv);
2166 zv->zv_flags &= ~ZVOL_DUMPIFIED;
2167 (void) dmu_free_long_range(os, ZVOL_OBJ, 0, DMU_OBJECT_END);
2168 /* wait for dmu_free_long_range to actually free the blocks */
2169 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0);
2170 tx = dmu_tx_create(os);
2171 dmu_tx_hold_bonus(tx, ZVOL_OBJ);
2172 error = dmu_tx_assign(tx, TXG_WAIT);
2173 if (error) {
2174 dmu_tx_abort(tx);
2175 return (error);
2176 }
2177 if (dmu_object_set_blocksize(os, ZVOL_OBJ, vbs, 0, tx) == 0)
2178 zv->zv_volblocksize = vbs;
2179 dmu_tx_commit(tx);
2180
2181 return (0);
2182 }
2183