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.
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.
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]
22 * Copyright (C) 2008-2010 Lawrence Livermore National Security, LLC.
23 * Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
24 * Rewritten for Linux by Brian Behlendorf <behlendorf1@llnl.gov>.
27 * ZFS volume emulation driver.
29 * Makes a DMU object look like a volume of arbitrary size, up to 2^64 bytes.
30 * Volumes are accessed through the symbolic links named:
32 * /dev/<pool_name>/<dataset_name>
34 * Volumes are persistent through reboot and module load. No user command
35 * needs to be run before opening and using a device.
39 #include <sys/dmu_traverse.h>
40 #include <sys/dsl_dataset.h>
41 #include <sys/dsl_prop.h>
43 #include <sys/zil_impl.h>
45 #include <sys/zfs_rlock.h>
46 #include <sys/zfs_znode.h>
48 #include <linux/blkdev_compat.h>
50 unsigned int zvol_inhibit_dev
= 0;
51 unsigned int zvol_major
= ZVOL_MAJOR
;
52 unsigned int zvol_threads
= 32;
53 unsigned long zvol_max_discard_blocks
= 16384;
55 static taskq_t
*zvol_taskq
;
56 static kmutex_t zvol_state_lock
;
57 static list_t zvol_state_list
;
58 static char *zvol_tag
= "zvol_tag";
61 * The in-core state of each volume.
63 typedef struct zvol_state
{
64 char zv_name
[MAXNAMELEN
]; /* name */
65 uint64_t zv_volsize
; /* advertised space */
66 uint64_t zv_volblocksize
; /* volume block size */
67 objset_t
*zv_objset
; /* objset handle */
68 uint32_t zv_flags
; /* ZVOL_* flags */
69 uint32_t zv_open_count
; /* open counts */
70 uint32_t zv_changed
; /* disk changed */
71 zilog_t
*zv_zilog
; /* ZIL handle */
72 znode_t zv_znode
; /* for range locking */
73 dmu_buf_t
*zv_dbuf
; /* bonus handle */
74 dev_t zv_dev
; /* device id */
75 struct gendisk
*zv_disk
; /* generic disk */
76 struct request_queue
*zv_queue
; /* request queue */
77 spinlock_t zv_lock
; /* request queue lock */
78 list_node_t zv_next
; /* next zvol_state_t linkage */
81 #define ZVOL_RDONLY 0x1
84 * Find the next available range of ZVOL_MINORS minor numbers. The
85 * zvol_state_list is kept in ascending minor order so we simply need
86 * to scan the list for the first gap in the sequence. This allows us
87 * to recycle minor number as devices are created and removed.
90 zvol_find_minor(unsigned *minor
)
95 ASSERT(MUTEX_HELD(&zvol_state_lock
));
96 for (zv
= list_head(&zvol_state_list
); zv
!= NULL
;
97 zv
= list_next(&zvol_state_list
, zv
), *minor
+= ZVOL_MINORS
) {
98 if (MINOR(zv
->zv_dev
) != MINOR(*minor
))
102 /* All minors are in use */
103 if (*minor
>= (1 << MINORBITS
))
104 return (SET_ERROR(ENXIO
));
110 * Find a zvol_state_t given the full major+minor dev_t.
112 static zvol_state_t
*
113 zvol_find_by_dev(dev_t dev
)
117 ASSERT(MUTEX_HELD(&zvol_state_lock
));
118 for (zv
= list_head(&zvol_state_list
); zv
!= NULL
;
119 zv
= list_next(&zvol_state_list
, zv
)) {
120 if (zv
->zv_dev
== dev
)
128 * Find a zvol_state_t given the name provided at zvol_alloc() time.
130 static zvol_state_t
*
131 zvol_find_by_name(const char *name
)
135 ASSERT(MUTEX_HELD(&zvol_state_lock
));
136 for (zv
= list_head(&zvol_state_list
); zv
!= NULL
;
137 zv
= list_next(&zvol_state_list
, zv
)) {
138 if (strncmp(zv
->zv_name
, name
, MAXNAMELEN
) == 0)
147 * Given a path, return TRUE if path is a ZVOL.
150 zvol_is_zvol(const char *device
)
152 struct block_device
*bdev
;
155 bdev
= lookup_bdev(device
);
159 major
= MAJOR(bdev
->bd_dev
);
162 if (major
== zvol_major
)
169 * ZFS_IOC_CREATE callback handles dmu zvol and zap object creation.
172 zvol_create_cb(objset_t
*os
, void *arg
, cred_t
*cr
, dmu_tx_t
*tx
)
174 zfs_creat_t
*zct
= arg
;
175 nvlist_t
*nvprops
= zct
->zct_props
;
177 uint64_t volblocksize
, volsize
;
179 VERIFY(nvlist_lookup_uint64(nvprops
,
180 zfs_prop_to_name(ZFS_PROP_VOLSIZE
), &volsize
) == 0);
181 if (nvlist_lookup_uint64(nvprops
,
182 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE
), &volblocksize
) != 0)
183 volblocksize
= zfs_prop_default_numeric(ZFS_PROP_VOLBLOCKSIZE
);
186 * These properties must be removed from the list so the generic
187 * property setting step won't apply to them.
189 VERIFY(nvlist_remove_all(nvprops
,
190 zfs_prop_to_name(ZFS_PROP_VOLSIZE
)) == 0);
191 (void) nvlist_remove_all(nvprops
,
192 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE
));
194 error
= dmu_object_claim(os
, ZVOL_OBJ
, DMU_OT_ZVOL
, volblocksize
,
198 error
= zap_create_claim(os
, ZVOL_ZAP_OBJ
, DMU_OT_ZVOL_PROP
,
202 error
= zap_update(os
, ZVOL_ZAP_OBJ
, "size", 8, 1, &volsize
, tx
);
207 * ZFS_IOC_OBJSET_STATS entry point.
210 zvol_get_stats(objset_t
*os
, nvlist_t
*nv
)
213 dmu_object_info_t
*doi
;
216 error
= zap_lookup(os
, ZVOL_ZAP_OBJ
, "size", 8, 1, &val
);
218 return (SET_ERROR(error
));
220 dsl_prop_nvlist_add_uint64(nv
, ZFS_PROP_VOLSIZE
, val
);
221 doi
= kmem_alloc(sizeof (dmu_object_info_t
), KM_SLEEP
);
222 error
= dmu_object_info(os
, ZVOL_OBJ
, doi
);
225 dsl_prop_nvlist_add_uint64(nv
, ZFS_PROP_VOLBLOCKSIZE
,
226 doi
->doi_data_block_size
);
229 kmem_free(doi
, sizeof (dmu_object_info_t
));
231 return (SET_ERROR(error
));
235 zvol_size_changed(zvol_state_t
*zv
, uint64_t volsize
)
237 struct block_device
*bdev
;
239 bdev
= bdget_disk(zv
->zv_disk
, 0);
244 * Added check_disk_size_change() helper function.
246 #ifdef HAVE_CHECK_DISK_SIZE_CHANGE
247 set_capacity(zv
->zv_disk
, volsize
>> 9);
248 zv
->zv_volsize
= volsize
;
249 check_disk_size_change(zv
->zv_disk
, bdev
);
251 zv
->zv_volsize
= volsize
;
253 (void) check_disk_change(bdev
);
254 #endif /* HAVE_CHECK_DISK_SIZE_CHANGE */
260 * Sanity check volume size.
263 zvol_check_volsize(uint64_t volsize
, uint64_t blocksize
)
266 return (SET_ERROR(EINVAL
));
268 if (volsize
% blocksize
!= 0)
269 return (SET_ERROR(EINVAL
));
272 if (volsize
- 1 > MAXOFFSET_T
)
273 return (SET_ERROR(EOVERFLOW
));
279 * Ensure the zap is flushed then inform the VFS of the capacity change.
282 zvol_update_volsize(uint64_t volsize
, objset_t
*os
)
287 ASSERT(MUTEX_HELD(&zvol_state_lock
));
289 tx
= dmu_tx_create(os
);
290 dmu_tx_hold_zap(tx
, ZVOL_ZAP_OBJ
, TRUE
, NULL
);
291 error
= dmu_tx_assign(tx
, TXG_WAIT
);
294 return (SET_ERROR(error
));
297 error
= zap_update(os
, ZVOL_ZAP_OBJ
, "size", 8, 1,
302 error
= dmu_free_long_range(os
,
303 ZVOL_OBJ
, volsize
, DMU_OBJECT_END
);
309 zvol_update_live_volsize(zvol_state_t
*zv
, uint64_t volsize
)
311 zvol_size_changed(zv
, volsize
);
314 * We should post a event here describing the expansion. However,
315 * the zfs_ereport_post() interface doesn't nicely support posting
316 * events for zvols, it assumes events relate to vdevs or zios.
323 * Set ZFS_PROP_VOLSIZE set entry point.
326 zvol_set_volsize(const char *name
, uint64_t volsize
)
328 zvol_state_t
*zv
= NULL
;
331 dmu_object_info_t
*doi
;
333 boolean_t owned
= B_FALSE
;
335 error
= dsl_prop_get_integer(name
,
336 zfs_prop_to_name(ZFS_PROP_READONLY
), &readonly
, NULL
);
338 return (SET_ERROR(error
));
340 return (SET_ERROR(EROFS
));
342 mutex_enter(&zvol_state_lock
);
343 zv
= zvol_find_by_name(name
);
345 if (zv
== NULL
|| zv
->zv_objset
== NULL
) {
346 if ((error
= dmu_objset_own(name
, DMU_OST_ZVOL
, B_FALSE
,
348 mutex_exit(&zvol_state_lock
);
349 return (SET_ERROR(error
));
358 doi
= kmem_alloc(sizeof (dmu_object_info_t
), KM_SLEEP
);
360 if ((error
= dmu_object_info(os
, ZVOL_OBJ
, doi
)) ||
361 (error
= zvol_check_volsize(volsize
, doi
->doi_data_block_size
)))
364 error
= zvol_update_volsize(volsize
, os
);
365 kmem_free(doi
, sizeof (dmu_object_info_t
));
367 if (error
== 0 && zv
!= NULL
)
368 error
= zvol_update_live_volsize(zv
, volsize
);
371 dmu_objset_disown(os
, FTAG
);
373 zv
->zv_objset
= NULL
;
375 mutex_exit(&zvol_state_lock
);
380 * Sanity check volume block size.
383 zvol_check_volblocksize(uint64_t volblocksize
)
385 if (volblocksize
< SPA_MINBLOCKSIZE
||
386 volblocksize
> SPA_MAXBLOCKSIZE
||
388 return (SET_ERROR(EDOM
));
394 * Set ZFS_PROP_VOLBLOCKSIZE set entry point.
397 zvol_set_volblocksize(const char *name
, uint64_t volblocksize
)
403 mutex_enter(&zvol_state_lock
);
405 zv
= zvol_find_by_name(name
);
407 error
= SET_ERROR(ENXIO
);
411 if (zv
->zv_flags
& ZVOL_RDONLY
) {
412 error
= SET_ERROR(EROFS
);
416 tx
= dmu_tx_create(zv
->zv_objset
);
417 dmu_tx_hold_bonus(tx
, ZVOL_OBJ
);
418 error
= dmu_tx_assign(tx
, TXG_WAIT
);
422 error
= dmu_object_set_blocksize(zv
->zv_objset
, ZVOL_OBJ
,
423 volblocksize
, 0, tx
);
424 if (error
== ENOTSUP
)
425 error
= SET_ERROR(EBUSY
);
428 zv
->zv_volblocksize
= volblocksize
;
431 mutex_exit(&zvol_state_lock
);
433 return (SET_ERROR(error
));
437 * Replay a TX_WRITE ZIL transaction that didn't get committed
438 * after a system failure
441 zvol_replay_write(zvol_state_t
*zv
, lr_write_t
*lr
, boolean_t byteswap
)
443 objset_t
*os
= zv
->zv_objset
;
444 char *data
= (char *)(lr
+ 1); /* data follows lr_write_t */
445 uint64_t off
= lr
->lr_offset
;
446 uint64_t len
= lr
->lr_length
;
451 byteswap_uint64_array(lr
, sizeof (*lr
));
453 tx
= dmu_tx_create(os
);
454 dmu_tx_hold_write(tx
, ZVOL_OBJ
, off
, len
);
455 error
= dmu_tx_assign(tx
, TXG_WAIT
);
459 dmu_write(os
, ZVOL_OBJ
, off
, len
, data
, tx
);
463 return (SET_ERROR(error
));
467 zvol_replay_err(zvol_state_t
*zv
, lr_t
*lr
, boolean_t byteswap
)
469 return (SET_ERROR(ENOTSUP
));
473 * Callback vectors for replaying records.
474 * Only TX_WRITE is needed for zvol.
476 zil_replay_func_t zvol_replay_vector
[TX_MAX_TYPE
] = {
477 (zil_replay_func_t
)zvol_replay_err
, /* no such transaction type */
478 (zil_replay_func_t
)zvol_replay_err
, /* TX_CREATE */
479 (zil_replay_func_t
)zvol_replay_err
, /* TX_MKDIR */
480 (zil_replay_func_t
)zvol_replay_err
, /* TX_MKXATTR */
481 (zil_replay_func_t
)zvol_replay_err
, /* TX_SYMLINK */
482 (zil_replay_func_t
)zvol_replay_err
, /* TX_REMOVE */
483 (zil_replay_func_t
)zvol_replay_err
, /* TX_RMDIR */
484 (zil_replay_func_t
)zvol_replay_err
, /* TX_LINK */
485 (zil_replay_func_t
)zvol_replay_err
, /* TX_RENAME */
486 (zil_replay_func_t
)zvol_replay_write
, /* TX_WRITE */
487 (zil_replay_func_t
)zvol_replay_err
, /* TX_TRUNCATE */
488 (zil_replay_func_t
)zvol_replay_err
, /* TX_SETATTR */
489 (zil_replay_func_t
)zvol_replay_err
, /* TX_ACL */
493 * zvol_log_write() handles synchronous writes using TX_WRITE ZIL transactions.
495 * We store data in the log buffers if it's small enough.
496 * Otherwise we will later flush the data out via dmu_sync().
498 ssize_t zvol_immediate_write_sz
= 32768;
501 zvol_log_write(zvol_state_t
*zv
, dmu_tx_t
*tx
, uint64_t offset
,
502 uint64_t size
, int sync
)
504 uint32_t blocksize
= zv
->zv_volblocksize
;
505 zilog_t
*zilog
= zv
->zv_zilog
;
507 ssize_t immediate_write_sz
;
509 if (zil_replaying(zilog
, tx
))
512 immediate_write_sz
= (zilog
->zl_logbias
== ZFS_LOGBIAS_THROUGHPUT
)
513 ? 0 : zvol_immediate_write_sz
;
514 slogging
= spa_has_slogs(zilog
->zl_spa
) &&
515 (zilog
->zl_logbias
== ZFS_LOGBIAS_LATENCY
);
521 itx_wr_state_t write_state
;
524 * Unlike zfs_log_write() we can be called with
525 * up to DMU_MAX_ACCESS/2 (5MB) writes.
527 if (blocksize
> immediate_write_sz
&& !slogging
&&
528 size
>= blocksize
&& offset
% blocksize
== 0) {
529 write_state
= WR_INDIRECT
; /* uses dmu_sync */
532 write_state
= WR_COPIED
;
533 len
= MIN(ZIL_MAX_LOG_DATA
, size
);
535 write_state
= WR_NEED_COPY
;
536 len
= MIN(ZIL_MAX_LOG_DATA
, size
);
539 itx
= zil_itx_create(TX_WRITE
, sizeof (*lr
) +
540 (write_state
== WR_COPIED
? len
: 0));
541 lr
= (lr_write_t
*)&itx
->itx_lr
;
542 if (write_state
== WR_COPIED
&& dmu_read(zv
->zv_objset
,
543 ZVOL_OBJ
, offset
, len
, lr
+1, DMU_READ_NO_PREFETCH
) != 0) {
544 zil_itx_destroy(itx
);
545 itx
= zil_itx_create(TX_WRITE
, sizeof (*lr
));
546 lr
= (lr_write_t
*)&itx
->itx_lr
;
547 write_state
= WR_NEED_COPY
;
550 itx
->itx_wr_state
= write_state
;
551 if (write_state
== WR_NEED_COPY
)
553 lr
->lr_foid
= ZVOL_OBJ
;
554 lr
->lr_offset
= offset
;
557 BP_ZERO(&lr
->lr_blkptr
);
559 itx
->itx_private
= zv
;
560 itx
->itx_sync
= sync
;
562 (void) zil_itx_assign(zilog
, itx
, tx
);
570 * Common write path running under the zvol taskq context. This function
571 * is responsible for copying the request structure data in to the DMU and
572 * signaling the request queue with the result of the copy.
575 zvol_write(void *arg
)
577 struct request
*req
= (struct request
*)arg
;
578 struct request_queue
*q
= req
->q
;
579 zvol_state_t
*zv
= q
->queuedata
;
580 fstrans_cookie_t cookie
= spl_fstrans_mark();
581 uint64_t offset
= blk_rq_pos(req
) << 9;
582 uint64_t size
= blk_rq_bytes(req
);
587 if (req
->cmd_flags
& VDEV_REQ_FLUSH
)
588 zil_commit(zv
->zv_zilog
, ZVOL_OBJ
);
591 * Some requests are just for flush and nothing else.
598 rl
= zfs_range_lock(&zv
->zv_znode
, offset
, size
, RL_WRITER
);
600 tx
= dmu_tx_create(zv
->zv_objset
);
601 dmu_tx_hold_write(tx
, ZVOL_OBJ
, offset
, size
);
603 /* This will only fail for ENOSPC */
604 error
= dmu_tx_assign(tx
, TXG_WAIT
);
607 zfs_range_unlock(rl
);
611 error
= dmu_write_req(zv
->zv_objset
, ZVOL_OBJ
, req
, tx
);
613 zvol_log_write(zv
, tx
, offset
, size
,
614 req
->cmd_flags
& VDEV_REQ_FUA
);
617 zfs_range_unlock(rl
);
619 if ((req
->cmd_flags
& VDEV_REQ_FUA
) ||
620 zv
->zv_objset
->os_sync
== ZFS_SYNC_ALWAYS
)
621 zil_commit(zv
->zv_zilog
, ZVOL_OBJ
);
624 blk_end_request(req
, -error
, size
);
625 spl_fstrans_unmark(cookie
);
628 #ifdef HAVE_BLK_QUEUE_DISCARD
630 zvol_discard(void *arg
)
632 struct request
*req
= (struct request
*)arg
;
633 struct request_queue
*q
= req
->q
;
634 zvol_state_t
*zv
= q
->queuedata
;
635 fstrans_cookie_t cookie
= spl_fstrans_mark();
636 uint64_t start
= blk_rq_pos(req
) << 9;
637 uint64_t end
= start
+ blk_rq_bytes(req
);
641 if (end
> zv
->zv_volsize
) {
647 * Align the request to volume block boundaries. If we don't,
648 * then this will force dnode_free_range() to zero out the
649 * unaligned parts, which is slow (read-modify-write) and
650 * useless since we are not freeing any space by doing so.
652 start
= P2ROUNDUP(start
, zv
->zv_volblocksize
);
653 end
= P2ALIGN(end
, zv
->zv_volblocksize
);
660 rl
= zfs_range_lock(&zv
->zv_znode
, start
, end
- start
, RL_WRITER
);
662 error
= dmu_free_long_range(zv
->zv_objset
, ZVOL_OBJ
, start
, end
-start
);
665 * TODO: maybe we should add the operation to the log.
668 zfs_range_unlock(rl
);
670 blk_end_request(req
, -error
, blk_rq_bytes(req
));
671 spl_fstrans_unmark(cookie
);
673 #endif /* HAVE_BLK_QUEUE_DISCARD */
676 * Common read path running under the zvol taskq context. This function
677 * is responsible for copying the requested data out of the DMU and in to
678 * a linux request structure. It then must signal the request queue with
679 * an error code describing the result of the copy.
684 struct request
*req
= (struct request
*)arg
;
685 struct request_queue
*q
= req
->q
;
686 zvol_state_t
*zv
= q
->queuedata
;
687 fstrans_cookie_t cookie
= spl_fstrans_mark();
688 uint64_t offset
= blk_rq_pos(req
) << 9;
689 uint64_t size
= blk_rq_bytes(req
);
698 rl
= zfs_range_lock(&zv
->zv_znode
, offset
, size
, RL_READER
);
700 error
= dmu_read_req(zv
->zv_objset
, ZVOL_OBJ
, req
);
702 zfs_range_unlock(rl
);
704 /* convert checksum errors into IO errors */
706 error
= SET_ERROR(EIO
);
709 blk_end_request(req
, -error
, size
);
710 spl_fstrans_unmark(cookie
);
714 * Request will be added back to the request queue and retried if
715 * it cannot be immediately dispatched to the taskq for handling
718 zvol_dispatch(task_func_t func
, struct request
*req
)
720 if (!taskq_dispatch(zvol_taskq
, func
, (void *)req
, TQ_NOSLEEP
))
721 blk_requeue_request(req
->q
, req
);
725 * Common request path. Rather than registering a custom make_request()
726 * function we use the generic Linux version. This is done because it allows
727 * us to easily merge read requests which would otherwise we performed
728 * synchronously by the DMU. This is less critical in write case where the
729 * DMU will perform the correct merging within a transaction group. Using
730 * the generic make_request() also let's use leverage the fact that the
731 * elevator with ensure correct ordering in regards to barrior IOs. On
732 * the downside it means that in the write case we end up doing request
733 * merging twice once in the elevator and once in the DMU.
735 * The request handler is called under a spin lock so all the real work
736 * is handed off to be done in the context of the zvol taskq. This function
737 * simply performs basic request sanity checking and hands off the request.
740 zvol_request(struct request_queue
*q
)
742 zvol_state_t
*zv
= q
->queuedata
;
746 while ((req
= blk_fetch_request(q
)) != NULL
) {
747 size
= blk_rq_bytes(req
);
749 if (size
!= 0 && blk_rq_pos(req
) + blk_rq_sectors(req
) >
750 get_capacity(zv
->zv_disk
)) {
752 "%s: bad access: block=%llu, count=%lu\n",
753 req
->rq_disk
->disk_name
,
754 (long long unsigned)blk_rq_pos(req
),
755 (long unsigned)blk_rq_sectors(req
));
756 __blk_end_request(req
, -EIO
, size
);
760 if (!blk_fs_request(req
)) {
761 printk(KERN_INFO
"%s: non-fs cmd\n",
762 req
->rq_disk
->disk_name
);
763 __blk_end_request(req
, -EIO
, size
);
767 switch ((int)rq_data_dir(req
)) {
769 zvol_dispatch(zvol_read
, req
);
772 if (unlikely(zv
->zv_flags
& ZVOL_RDONLY
)) {
773 __blk_end_request(req
, -EROFS
, size
);
777 #ifdef HAVE_BLK_QUEUE_DISCARD
778 if (req
->cmd_flags
& VDEV_REQ_DISCARD
) {
779 zvol_dispatch(zvol_discard
, req
);
782 #endif /* HAVE_BLK_QUEUE_DISCARD */
784 zvol_dispatch(zvol_write
, req
);
787 printk(KERN_INFO
"%s: unknown cmd: %d\n",
788 req
->rq_disk
->disk_name
, (int)rq_data_dir(req
));
789 __blk_end_request(req
, -EIO
, size
);
796 zvol_get_done(zgd_t
*zgd
, int error
)
799 dmu_buf_rele(zgd
->zgd_db
, zgd
);
801 zfs_range_unlock(zgd
->zgd_rl
);
803 if (error
== 0 && zgd
->zgd_bp
)
804 zil_add_block(zgd
->zgd_zilog
, zgd
->zgd_bp
);
806 kmem_free(zgd
, sizeof (zgd_t
));
810 * Get data to generate a TX_WRITE intent log record.
813 zvol_get_data(void *arg
, lr_write_t
*lr
, char *buf
, zio_t
*zio
)
815 zvol_state_t
*zv
= arg
;
816 objset_t
*os
= zv
->zv_objset
;
817 uint64_t object
= ZVOL_OBJ
;
818 uint64_t offset
= lr
->lr_offset
;
819 uint64_t size
= lr
->lr_length
;
820 blkptr_t
*bp
= &lr
->lr_blkptr
;
828 zgd
= (zgd_t
*)kmem_zalloc(sizeof (zgd_t
), KM_SLEEP
);
829 zgd
->zgd_zilog
= zv
->zv_zilog
;
830 zgd
->zgd_rl
= zfs_range_lock(&zv
->zv_znode
, offset
, size
, RL_READER
);
833 * Write records come in two flavors: immediate and indirect.
834 * For small writes it's cheaper to store the data with the
835 * log record (immediate); for large writes it's cheaper to
836 * sync the data and get a pointer to it (indirect) so that
837 * we don't have to write the data twice.
839 if (buf
!= NULL
) { /* immediate write */
840 error
= dmu_read(os
, object
, offset
, size
, buf
,
841 DMU_READ_NO_PREFETCH
);
843 size
= zv
->zv_volblocksize
;
844 offset
= P2ALIGN_TYPED(offset
, size
, uint64_t);
845 error
= dmu_buf_hold(os
, object
, offset
, zgd
, &db
,
846 DMU_READ_NO_PREFETCH
);
848 blkptr_t
*obp
= dmu_buf_get_blkptr(db
);
850 ASSERT(BP_IS_HOLE(bp
));
855 zgd
->zgd_bp
= &lr
->lr_blkptr
;
858 ASSERT(db
->db_offset
== offset
);
859 ASSERT(db
->db_size
== size
);
861 error
= dmu_sync(zio
, lr
->lr_common
.lrc_txg
,
869 zvol_get_done(zgd
, error
);
871 return (SET_ERROR(error
));
875 * The zvol_state_t's are inserted in increasing MINOR(dev_t) order.
878 zvol_insert(zvol_state_t
*zv_insert
)
880 zvol_state_t
*zv
= NULL
;
882 ASSERT(MUTEX_HELD(&zvol_state_lock
));
883 ASSERT3U(MINOR(zv_insert
->zv_dev
) & ZVOL_MINOR_MASK
, ==, 0);
884 for (zv
= list_head(&zvol_state_list
); zv
!= NULL
;
885 zv
= list_next(&zvol_state_list
, zv
)) {
886 if (MINOR(zv
->zv_dev
) > MINOR(zv_insert
->zv_dev
))
890 list_insert_before(&zvol_state_list
, zv
, zv_insert
);
894 * Simply remove the zvol from to list of zvols.
897 zvol_remove(zvol_state_t
*zv_remove
)
899 ASSERT(MUTEX_HELD(&zvol_state_lock
));
900 list_remove(&zvol_state_list
, zv_remove
);
904 zvol_first_open(zvol_state_t
*zv
)
913 * In all other cases the spa_namespace_lock is taken before the
914 * bdev->bd_mutex lock. But in this case the Linux __blkdev_get()
915 * function calls fops->open() with the bdev->bd_mutex lock held.
917 * To avoid a potential lock inversion deadlock we preemptively
918 * try to take the spa_namespace_lock(). Normally it will not
919 * be contended and this is safe because spa_open_common() handles
920 * the case where the caller already holds the spa_namespace_lock.
922 * When it is contended we risk a lock inversion if we were to
923 * block waiting for the lock. Luckily, the __blkdev_get()
924 * function allows us to return -ERESTARTSYS which will result in
925 * bdev->bd_mutex being dropped, reacquired, and fops->open() being
926 * called again. This process can be repeated safely until both
927 * locks are acquired.
929 if (!mutex_owned(&spa_namespace_lock
)) {
930 locked
= mutex_tryenter(&spa_namespace_lock
);
932 return (-SET_ERROR(ERESTARTSYS
));
935 error
= dsl_prop_get_integer(zv
->zv_name
, "readonly", &ro
, NULL
);
939 /* lie and say we're read-only */
940 error
= dmu_objset_own(zv
->zv_name
, DMU_OST_ZVOL
, 1, zvol_tag
, &os
);
944 error
= zap_lookup(os
, ZVOL_ZAP_OBJ
, "size", 8, 1, &volsize
);
946 dmu_objset_disown(os
, zvol_tag
);
951 error
= dmu_bonus_hold(os
, ZVOL_OBJ
, zvol_tag
, &zv
->zv_dbuf
);
953 dmu_objset_disown(os
, zvol_tag
);
957 set_capacity(zv
->zv_disk
, volsize
>> 9);
958 zv
->zv_volsize
= volsize
;
959 zv
->zv_zilog
= zil_open(os
, zvol_get_data
);
961 if (ro
|| dmu_objset_is_snapshot(os
) ||
962 !spa_writeable(dmu_objset_spa(os
))) {
963 set_disk_ro(zv
->zv_disk
, 1);
964 zv
->zv_flags
|= ZVOL_RDONLY
;
966 set_disk_ro(zv
->zv_disk
, 0);
967 zv
->zv_flags
&= ~ZVOL_RDONLY
;
972 mutex_exit(&spa_namespace_lock
);
974 return (SET_ERROR(-error
));
978 zvol_last_close(zvol_state_t
*zv
)
980 zil_close(zv
->zv_zilog
);
983 dmu_buf_rele(zv
->zv_dbuf
, zvol_tag
);
989 if (dsl_dataset_is_dirty(dmu_objset_ds(zv
->zv_objset
)) &&
990 !(zv
->zv_flags
& ZVOL_RDONLY
))
991 txg_wait_synced(dmu_objset_pool(zv
->zv_objset
), 0);
992 (void) dmu_objset_evict_dbufs(zv
->zv_objset
);
994 dmu_objset_disown(zv
->zv_objset
, zvol_tag
);
995 zv
->zv_objset
= NULL
;
999 zvol_open(struct block_device
*bdev
, fmode_t flag
)
1001 zvol_state_t
*zv
= bdev
->bd_disk
->private_data
;
1002 int error
= 0, drop_mutex
= 0;
1005 * If the caller is already holding the mutex do not take it
1006 * again, this will happen as part of zvol_create_minor().
1007 * Once add_disk() is called the device is live and the kernel
1008 * will attempt to open it to read the partition information.
1010 if (!mutex_owned(&zvol_state_lock
)) {
1011 mutex_enter(&zvol_state_lock
);
1015 ASSERT3P(zv
, !=, NULL
);
1017 if (zv
->zv_open_count
== 0) {
1018 error
= zvol_first_open(zv
);
1023 if ((flag
& FMODE_WRITE
) && (zv
->zv_flags
& ZVOL_RDONLY
)) {
1025 goto out_open_count
;
1028 zv
->zv_open_count
++;
1031 if (zv
->zv_open_count
== 0)
1032 zvol_last_close(zv
);
1036 mutex_exit(&zvol_state_lock
);
1038 check_disk_change(bdev
);
1040 return (SET_ERROR(error
));
1043 #ifdef HAVE_BLOCK_DEVICE_OPERATIONS_RELEASE_VOID
1048 zvol_release(struct gendisk
*disk
, fmode_t mode
)
1050 zvol_state_t
*zv
= disk
->private_data
;
1053 if (!mutex_owned(&zvol_state_lock
)) {
1054 mutex_enter(&zvol_state_lock
);
1058 if (zv
->zv_open_count
> 0) {
1059 zv
->zv_open_count
--;
1060 if (zv
->zv_open_count
== 0)
1061 zvol_last_close(zv
);
1065 mutex_exit(&zvol_state_lock
);
1067 #ifndef HAVE_BLOCK_DEVICE_OPERATIONS_RELEASE_VOID
1073 zvol_ioctl(struct block_device
*bdev
, fmode_t mode
,
1074 unsigned int cmd
, unsigned long arg
)
1076 zvol_state_t
*zv
= bdev
->bd_disk
->private_data
;
1080 return (SET_ERROR(-ENXIO
));
1084 zil_commit(zv
->zv_zilog
, ZVOL_OBJ
);
1087 error
= copy_to_user((void *)arg
, zv
->zv_name
, MAXNAMELEN
);
1096 return (SET_ERROR(error
));
1099 #ifdef CONFIG_COMPAT
1101 zvol_compat_ioctl(struct block_device
*bdev
, fmode_t mode
,
1102 unsigned cmd
, unsigned long arg
)
1104 return (zvol_ioctl(bdev
, mode
, cmd
, arg
));
1107 #define zvol_compat_ioctl NULL
1110 static int zvol_media_changed(struct gendisk
*disk
)
1112 zvol_state_t
*zv
= disk
->private_data
;
1114 return (zv
->zv_changed
);
1117 static int zvol_revalidate_disk(struct gendisk
*disk
)
1119 zvol_state_t
*zv
= disk
->private_data
;
1122 set_capacity(zv
->zv_disk
, zv
->zv_volsize
>> 9);
1128 * Provide a simple virtual geometry for legacy compatibility. For devices
1129 * smaller than 1 MiB a small head and sector count is used to allow very
1130 * tiny devices. For devices over 1 Mib a standard head and sector count
1131 * is used to keep the cylinders count reasonable.
1134 zvol_getgeo(struct block_device
*bdev
, struct hd_geometry
*geo
)
1136 zvol_state_t
*zv
= bdev
->bd_disk
->private_data
;
1137 sector_t sectors
= get_capacity(zv
->zv_disk
);
1139 if (sectors
> 2048) {
1148 geo
->cylinders
= sectors
/ (geo
->heads
* geo
->sectors
);
1153 static struct kobject
*
1154 zvol_probe(dev_t dev
, int *part
, void *arg
)
1157 struct kobject
*kobj
;
1159 mutex_enter(&zvol_state_lock
);
1160 zv
= zvol_find_by_dev(dev
);
1161 kobj
= zv
? get_disk(zv
->zv_disk
) : NULL
;
1162 mutex_exit(&zvol_state_lock
);
1167 #ifdef HAVE_BDEV_BLOCK_DEVICE_OPERATIONS
1168 static struct block_device_operations zvol_ops
= {
1170 .release
= zvol_release
,
1171 .ioctl
= zvol_ioctl
,
1172 .compat_ioctl
= zvol_compat_ioctl
,
1173 .media_changed
= zvol_media_changed
,
1174 .revalidate_disk
= zvol_revalidate_disk
,
1175 .getgeo
= zvol_getgeo
,
1176 .owner
= THIS_MODULE
,
1179 #else /* HAVE_BDEV_BLOCK_DEVICE_OPERATIONS */
1182 zvol_open_by_inode(struct inode
*inode
, struct file
*file
)
1184 return (zvol_open(inode
->i_bdev
, file
->f_mode
));
1188 zvol_release_by_inode(struct inode
*inode
, struct file
*file
)
1190 return (zvol_release(inode
->i_bdev
->bd_disk
, file
->f_mode
));
1194 zvol_ioctl_by_inode(struct inode
*inode
, struct file
*file
,
1195 unsigned int cmd
, unsigned long arg
)
1197 if (file
== NULL
|| inode
== NULL
)
1198 return (SET_ERROR(-EINVAL
));
1200 return (zvol_ioctl(inode
->i_bdev
, file
->f_mode
, cmd
, arg
));
1203 #ifdef CONFIG_COMPAT
1205 zvol_compat_ioctl_by_inode(struct file
*file
,
1206 unsigned int cmd
, unsigned long arg
)
1209 return (SET_ERROR(-EINVAL
));
1211 return (zvol_compat_ioctl(file
->f_dentry
->d_inode
->i_bdev
,
1212 file
->f_mode
, cmd
, arg
));
1215 #define zvol_compat_ioctl_by_inode NULL
1218 static struct block_device_operations zvol_ops
= {
1219 .open
= zvol_open_by_inode
,
1220 .release
= zvol_release_by_inode
,
1221 .ioctl
= zvol_ioctl_by_inode
,
1222 .compat_ioctl
= zvol_compat_ioctl_by_inode
,
1223 .media_changed
= zvol_media_changed
,
1224 .revalidate_disk
= zvol_revalidate_disk
,
1225 .getgeo
= zvol_getgeo
,
1226 .owner
= THIS_MODULE
,
1228 #endif /* HAVE_BDEV_BLOCK_DEVICE_OPERATIONS */
1231 * Allocate memory for a new zvol_state_t and setup the required
1232 * request queue and generic disk structures for the block device.
1234 static zvol_state_t
*
1235 zvol_alloc(dev_t dev
, const char *name
)
1240 zv
= kmem_zalloc(sizeof (zvol_state_t
), KM_SLEEP
);
1242 spin_lock_init(&zv
->zv_lock
);
1243 list_link_init(&zv
->zv_next
);
1245 zv
->zv_queue
= blk_init_queue(zvol_request
, &zv
->zv_lock
);
1246 if (zv
->zv_queue
== NULL
)
1249 #ifdef HAVE_ELEVATOR_CHANGE
1250 error
= elevator_change(zv
->zv_queue
, "noop");
1251 #endif /* HAVE_ELEVATOR_CHANGE */
1253 printk("ZFS: Unable to set \"%s\" scheduler for zvol %s: %d\n",
1254 "noop", name
, error
);
1258 #ifdef HAVE_BLK_QUEUE_FLUSH
1259 blk_queue_flush(zv
->zv_queue
, VDEV_REQ_FLUSH
| VDEV_REQ_FUA
);
1261 blk_queue_ordered(zv
->zv_queue
, QUEUE_ORDERED_DRAIN
, NULL
);
1262 #endif /* HAVE_BLK_QUEUE_FLUSH */
1264 zv
->zv_disk
= alloc_disk(ZVOL_MINORS
);
1265 if (zv
->zv_disk
== NULL
)
1268 zv
->zv_queue
->queuedata
= zv
;
1270 zv
->zv_open_count
= 0;
1271 strlcpy(zv
->zv_name
, name
, MAXNAMELEN
);
1273 mutex_init(&zv
->zv_znode
.z_range_lock
, NULL
, MUTEX_DEFAULT
, NULL
);
1274 avl_create(&zv
->zv_znode
.z_range_avl
, zfs_range_compare
,
1275 sizeof (rl_t
), offsetof(rl_t
, r_node
));
1276 zv
->zv_znode
.z_is_zvol
= TRUE
;
1278 zv
->zv_disk
->major
= zvol_major
;
1279 zv
->zv_disk
->first_minor
= (dev
& MINORMASK
);
1280 zv
->zv_disk
->fops
= &zvol_ops
;
1281 zv
->zv_disk
->private_data
= zv
;
1282 zv
->zv_disk
->queue
= zv
->zv_queue
;
1283 snprintf(zv
->zv_disk
->disk_name
, DISK_NAME_LEN
, "%s%d",
1284 ZVOL_DEV_NAME
, (dev
& MINORMASK
));
1289 blk_cleanup_queue(zv
->zv_queue
);
1291 kmem_free(zv
, sizeof (zvol_state_t
));
1297 * Cleanup then free a zvol_state_t which was created by zvol_alloc().
1300 zvol_free(zvol_state_t
*zv
)
1302 avl_destroy(&zv
->zv_znode
.z_range_avl
);
1303 mutex_destroy(&zv
->zv_znode
.z_range_lock
);
1305 del_gendisk(zv
->zv_disk
);
1306 blk_cleanup_queue(zv
->zv_queue
);
1307 put_disk(zv
->zv_disk
);
1309 kmem_free(zv
, sizeof (zvol_state_t
));
1313 __zvol_snapdev_hidden(const char *name
)
1320 parent
= kmem_alloc(MAXPATHLEN
, KM_SLEEP
);
1321 (void) strlcpy(parent
, name
, MAXPATHLEN
);
1323 if ((atp
= strrchr(parent
, '@')) != NULL
) {
1325 error
= dsl_prop_get_integer(parent
, "snapdev", &snapdev
, NULL
);
1326 if ((error
== 0) && (snapdev
== ZFS_SNAPDEV_HIDDEN
))
1327 error
= SET_ERROR(ENODEV
);
1330 kmem_free(parent
, MAXPATHLEN
);
1332 return (SET_ERROR(error
));
1336 __zvol_create_minor(const char *name
, boolean_t ignore_snapdev
)
1340 dmu_object_info_t
*doi
;
1345 ASSERT(MUTEX_HELD(&zvol_state_lock
));
1347 zv
= zvol_find_by_name(name
);
1349 error
= SET_ERROR(EEXIST
);
1353 if (ignore_snapdev
== B_FALSE
) {
1354 error
= __zvol_snapdev_hidden(name
);
1359 doi
= kmem_alloc(sizeof (dmu_object_info_t
), KM_SLEEP
);
1361 error
= dmu_objset_own(name
, DMU_OST_ZVOL
, B_TRUE
, zvol_tag
, &os
);
1365 error
= dmu_object_info(os
, ZVOL_OBJ
, doi
);
1367 goto out_dmu_objset_disown
;
1369 error
= zap_lookup(os
, ZVOL_ZAP_OBJ
, "size", 8, 1, &volsize
);
1371 goto out_dmu_objset_disown
;
1373 error
= zvol_find_minor(&minor
);
1375 goto out_dmu_objset_disown
;
1377 zv
= zvol_alloc(MKDEV(zvol_major
, minor
), name
);
1379 error
= SET_ERROR(EAGAIN
);
1380 goto out_dmu_objset_disown
;
1383 if (dmu_objset_is_snapshot(os
))
1384 zv
->zv_flags
|= ZVOL_RDONLY
;
1386 zv
->zv_volblocksize
= doi
->doi_data_block_size
;
1387 zv
->zv_volsize
= volsize
;
1390 set_capacity(zv
->zv_disk
, zv
->zv_volsize
>> 9);
1392 blk_queue_max_hw_sectors(zv
->zv_queue
, DMU_MAX_ACCESS
/ 512);
1393 blk_queue_max_segments(zv
->zv_queue
, UINT16_MAX
);
1394 blk_queue_max_segment_size(zv
->zv_queue
, UINT_MAX
);
1395 blk_queue_physical_block_size(zv
->zv_queue
, zv
->zv_volblocksize
);
1396 blk_queue_io_opt(zv
->zv_queue
, zv
->zv_volblocksize
);
1397 #ifdef HAVE_BLK_QUEUE_DISCARD
1398 blk_queue_max_discard_sectors(zv
->zv_queue
,
1399 (zvol_max_discard_blocks
* zv
->zv_volblocksize
) >> 9);
1400 blk_queue_discard_granularity(zv
->zv_queue
, zv
->zv_volblocksize
);
1401 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD
, zv
->zv_queue
);
1403 #ifdef HAVE_BLK_QUEUE_NONROT
1404 queue_flag_set_unlocked(QUEUE_FLAG_NONROT
, zv
->zv_queue
);
1407 if (spa_writeable(dmu_objset_spa(os
))) {
1408 if (zil_replay_disable
)
1409 zil_destroy(dmu_objset_zil(os
), B_FALSE
);
1411 zil_replay(os
, zv
, zvol_replay_vector
);
1414 zv
->zv_objset
= NULL
;
1415 out_dmu_objset_disown
:
1416 dmu_objset_disown(os
, zvol_tag
);
1418 kmem_free(doi
, sizeof (dmu_object_info_t
));
1423 add_disk(zv
->zv_disk
);
1426 return (SET_ERROR(error
));
1430 * Create a block device minor node and setup the linkage between it
1431 * and the specified volume. Once this function returns the block
1432 * device is live and ready for use.
1435 zvol_create_minor(const char *name
)
1439 mutex_enter(&zvol_state_lock
);
1440 error
= __zvol_create_minor(name
, B_FALSE
);
1441 mutex_exit(&zvol_state_lock
);
1443 return (SET_ERROR(error
));
1447 __zvol_remove_minor(const char *name
)
1451 ASSERT(MUTEX_HELD(&zvol_state_lock
));
1453 zv
= zvol_find_by_name(name
);
1455 return (SET_ERROR(ENXIO
));
1457 if (zv
->zv_open_count
> 0)
1458 return (SET_ERROR(EBUSY
));
1467 * Remove a block device minor node for the specified volume.
1470 zvol_remove_minor(const char *name
)
1474 mutex_enter(&zvol_state_lock
);
1475 error
= __zvol_remove_minor(name
);
1476 mutex_exit(&zvol_state_lock
);
1478 return (SET_ERROR(error
));
1482 * Rename a block device minor mode for the specified volume.
1485 __zvol_rename_minor(zvol_state_t
*zv
, const char *newname
)
1487 int readonly
= get_disk_ro(zv
->zv_disk
);
1489 ASSERT(MUTEX_HELD(&zvol_state_lock
));
1491 strlcpy(zv
->zv_name
, newname
, sizeof (zv
->zv_name
));
1494 * The block device's read-only state is briefly changed causing
1495 * a KOBJ_CHANGE uevent to be issued. This ensures udev detects
1496 * the name change and fixes the symlinks. This does not change
1497 * ZVOL_RDONLY in zv->zv_flags so the actual read-only state never
1498 * changes. This would normally be done using kobject_uevent() but
1499 * that is a GPL-only symbol which is why we need this workaround.
1501 set_disk_ro(zv
->zv_disk
, !readonly
);
1502 set_disk_ro(zv
->zv_disk
, readonly
);
1506 zvol_create_minors_cb(const char *dsname
, void *arg
)
1508 (void) zvol_create_minor(dsname
);
1514 * Create minors for specified dataset including children and snapshots.
1517 zvol_create_minors(const char *name
)
1521 if (!zvol_inhibit_dev
)
1522 error
= dmu_objset_find((char *)name
, zvol_create_minors_cb
,
1523 NULL
, DS_FIND_CHILDREN
| DS_FIND_SNAPSHOTS
);
1525 return (SET_ERROR(error
));
1529 * Remove minors for specified dataset including children and snapshots.
1532 zvol_remove_minors(const char *name
)
1534 zvol_state_t
*zv
, *zv_next
;
1535 int namelen
= ((name
) ? strlen(name
) : 0);
1537 if (zvol_inhibit_dev
)
1540 mutex_enter(&zvol_state_lock
);
1542 for (zv
= list_head(&zvol_state_list
); zv
!= NULL
; zv
= zv_next
) {
1543 zv_next
= list_next(&zvol_state_list
, zv
);
1545 if (name
== NULL
|| strcmp(zv
->zv_name
, name
) == 0 ||
1546 (strncmp(zv
->zv_name
, name
, namelen
) == 0 &&
1547 zv
->zv_name
[namelen
] == '/')) {
1553 mutex_exit(&zvol_state_lock
);
1557 * Rename minors for specified dataset including children and snapshots.
1560 zvol_rename_minors(const char *oldname
, const char *newname
)
1562 zvol_state_t
*zv
, *zv_next
;
1563 int oldnamelen
, newnamelen
;
1566 if (zvol_inhibit_dev
)
1569 oldnamelen
= strlen(oldname
);
1570 newnamelen
= strlen(newname
);
1571 name
= kmem_alloc(MAXNAMELEN
, KM_SLEEP
);
1573 mutex_enter(&zvol_state_lock
);
1575 for (zv
= list_head(&zvol_state_list
); zv
!= NULL
; zv
= zv_next
) {
1576 zv_next
= list_next(&zvol_state_list
, zv
);
1578 if (strcmp(zv
->zv_name
, oldname
) == 0) {
1579 __zvol_rename_minor(zv
, newname
);
1580 } else if (strncmp(zv
->zv_name
, oldname
, oldnamelen
) == 0 &&
1581 (zv
->zv_name
[oldnamelen
] == '/' ||
1582 zv
->zv_name
[oldnamelen
] == '@')) {
1583 snprintf(name
, MAXNAMELEN
, "%s%c%s", newname
,
1584 zv
->zv_name
[oldnamelen
],
1585 zv
->zv_name
+ oldnamelen
+ 1);
1586 __zvol_rename_minor(zv
, name
);
1590 mutex_exit(&zvol_state_lock
);
1592 kmem_free(name
, MAXNAMELEN
);
1596 snapdev_snapshot_changed_cb(const char *dsname
, void *arg
) {
1597 uint64_t snapdev
= *(uint64_t *) arg
;
1599 if (strchr(dsname
, '@') == NULL
)
1603 case ZFS_SNAPDEV_VISIBLE
:
1604 mutex_enter(&zvol_state_lock
);
1605 (void) __zvol_create_minor(dsname
, B_TRUE
);
1606 mutex_exit(&zvol_state_lock
);
1608 case ZFS_SNAPDEV_HIDDEN
:
1609 (void) zvol_remove_minor(dsname
);
1617 zvol_set_snapdev(const char *dsname
, uint64_t snapdev
) {
1618 (void) dmu_objset_find((char *) dsname
, snapdev_snapshot_changed_cb
,
1619 &snapdev
, DS_FIND_SNAPSHOTS
| DS_FIND_CHILDREN
);
1620 /* caller should continue to modify snapdev property */
1629 list_create(&zvol_state_list
, sizeof (zvol_state_t
),
1630 offsetof(zvol_state_t
, zv_next
));
1632 mutex_init(&zvol_state_lock
, NULL
, MUTEX_DEFAULT
, NULL
);
1634 zvol_taskq
= taskq_create(ZVOL_DRIVER
, zvol_threads
, maxclsyspri
,
1635 zvol_threads
* 2, INT_MAX
, TASKQ_PREPOPULATE
| TASKQ_DYNAMIC
);
1636 if (zvol_taskq
== NULL
) {
1637 printk(KERN_INFO
"ZFS: taskq_create() failed\n");
1642 error
= register_blkdev(zvol_major
, ZVOL_DRIVER
);
1644 printk(KERN_INFO
"ZFS: register_blkdev() failed %d\n", error
);
1648 blk_register_region(MKDEV(zvol_major
, 0), 1UL << MINORBITS
,
1649 THIS_MODULE
, zvol_probe
, NULL
, NULL
);
1654 taskq_destroy(zvol_taskq
);
1656 mutex_destroy(&zvol_state_lock
);
1657 list_destroy(&zvol_state_list
);
1659 return (SET_ERROR(error
));
1665 zvol_remove_minors(NULL
);
1666 blk_unregister_region(MKDEV(zvol_major
, 0), 1UL << MINORBITS
);
1667 unregister_blkdev(zvol_major
, ZVOL_DRIVER
);
1668 taskq_destroy(zvol_taskq
);
1669 mutex_destroy(&zvol_state_lock
);
1670 list_destroy(&zvol_state_list
);
1673 module_param(zvol_inhibit_dev
, uint
, 0644);
1674 MODULE_PARM_DESC(zvol_inhibit_dev
, "Do not create zvol device nodes");
1676 module_param(zvol_major
, uint
, 0444);
1677 MODULE_PARM_DESC(zvol_major
, "Major number for zvol device");
1679 module_param(zvol_threads
, uint
, 0444);
1680 MODULE_PARM_DESC(zvol_threads
, "Number of threads for zvol device");
1682 module_param(zvol_max_discard_blocks
, ulong
, 0444);
1683 MODULE_PARM_DESC(zvol_max_discard_blocks
, "Max number of blocks to discard");