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
))
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
))
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
);
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
));
235 * Sanity check volume size.
238 zvol_check_volsize(uint64_t volsize
, uint64_t blocksize
)
241 return (SET_ERROR(EINVAL
));
243 if (volsize
% blocksize
!= 0)
244 return (SET_ERROR(EINVAL
));
247 if (volsize
- 1 > MAXOFFSET_T
)
248 return (SET_ERROR(EOVERFLOW
));
254 * Ensure the zap is flushed then inform the VFS of the capacity change.
257 zvol_update_volsize(zvol_state_t
*zv
, uint64_t volsize
, objset_t
*os
)
259 struct block_device
*bdev
;
263 ASSERT(MUTEX_HELD(&zvol_state_lock
));
265 tx
= dmu_tx_create(os
);
266 dmu_tx_hold_zap(tx
, ZVOL_ZAP_OBJ
, TRUE
, NULL
);
267 error
= dmu_tx_assign(tx
, TXG_WAIT
);
273 error
= zap_update(os
, ZVOL_ZAP_OBJ
, "size", 8, 1,
280 error
= dmu_free_long_range(os
,
281 ZVOL_OBJ
, volsize
, DMU_OBJECT_END
);
285 bdev
= bdget_disk(zv
->zv_disk
, 0);
287 return (SET_ERROR(EIO
));
290 * Added check_disk_size_change() helper function.
292 #ifdef HAVE_CHECK_DISK_SIZE_CHANGE
293 set_capacity(zv
->zv_disk
, volsize
>> 9);
294 zv
->zv_volsize
= volsize
;
295 check_disk_size_change(zv
->zv_disk
, bdev
);
297 zv
->zv_volsize
= volsize
;
299 (void) check_disk_change(bdev
);
300 #endif /* HAVE_CHECK_DISK_SIZE_CHANGE */
308 * Set ZFS_PROP_VOLSIZE set entry point.
311 zvol_set_volsize(const char *name
, uint64_t volsize
)
314 dmu_object_info_t
*doi
;
319 error
= dsl_prop_get_integer(name
,
320 zfs_prop_to_name(ZFS_PROP_READONLY
), &readonly
, NULL
);
324 return (SET_ERROR(EROFS
));
326 mutex_enter(&zvol_state_lock
);
328 zv
= zvol_find_by_name(name
);
330 error
= SET_ERROR(ENXIO
);
334 doi
= kmem_alloc(sizeof(dmu_object_info_t
), KM_SLEEP
);
336 error
= dmu_objset_hold(name
, FTAG
, &os
);
340 if ((error
= dmu_object_info(os
, ZVOL_OBJ
, doi
)) != 0 ||
341 (error
= zvol_check_volsize(volsize
,doi
->doi_data_block_size
)) != 0)
344 VERIFY(dsl_prop_get_integer(name
, "readonly", &readonly
, NULL
) == 0);
346 error
= SET_ERROR(EROFS
);
350 if (zv
->zv_flags
& ZVOL_RDONLY
) {
351 error
= SET_ERROR(EROFS
);
355 error
= zvol_update_volsize(zv
, volsize
, os
);
357 kmem_free(doi
, sizeof(dmu_object_info_t
));
360 dmu_objset_rele(os
, FTAG
);
362 mutex_exit(&zvol_state_lock
);
368 * Sanity check volume block size.
371 zvol_check_volblocksize(uint64_t volblocksize
)
373 if (volblocksize
< SPA_MINBLOCKSIZE
||
374 volblocksize
> SPA_MAXBLOCKSIZE
||
376 return (SET_ERROR(EDOM
));
382 * Set ZFS_PROP_VOLBLOCKSIZE set entry point.
385 zvol_set_volblocksize(const char *name
, uint64_t volblocksize
)
391 mutex_enter(&zvol_state_lock
);
393 zv
= zvol_find_by_name(name
);
395 error
= SET_ERROR(ENXIO
);
399 if (zv
->zv_flags
& ZVOL_RDONLY
) {
400 error
= SET_ERROR(EROFS
);
404 tx
= dmu_tx_create(zv
->zv_objset
);
405 dmu_tx_hold_bonus(tx
, ZVOL_OBJ
);
406 error
= dmu_tx_assign(tx
, TXG_WAIT
);
410 error
= dmu_object_set_blocksize(zv
->zv_objset
, ZVOL_OBJ
,
411 volblocksize
, 0, tx
);
412 if (error
== ENOTSUP
)
413 error
= SET_ERROR(EBUSY
);
416 zv
->zv_volblocksize
= volblocksize
;
419 mutex_exit(&zvol_state_lock
);
425 * Replay a TX_WRITE ZIL transaction that didn't get committed
426 * after a system failure
429 zvol_replay_write(zvol_state_t
*zv
, lr_write_t
*lr
, boolean_t byteswap
)
431 objset_t
*os
= zv
->zv_objset
;
432 char *data
= (char *)(lr
+ 1); /* data follows lr_write_t */
433 uint64_t off
= lr
->lr_offset
;
434 uint64_t len
= lr
->lr_length
;
439 byteswap_uint64_array(lr
, sizeof (*lr
));
441 tx
= dmu_tx_create(os
);
442 dmu_tx_hold_write(tx
, ZVOL_OBJ
, off
, len
);
443 error
= dmu_tx_assign(tx
, TXG_WAIT
);
447 dmu_write(os
, ZVOL_OBJ
, off
, len
, data
, tx
);
455 zvol_replay_err(zvol_state_t
*zv
, lr_t
*lr
, boolean_t byteswap
)
457 return (SET_ERROR(ENOTSUP
));
461 * Callback vectors for replaying records.
462 * Only TX_WRITE is needed for zvol.
464 zil_replay_func_t zvol_replay_vector
[TX_MAX_TYPE
] = {
465 (zil_replay_func_t
)zvol_replay_err
, /* no such transaction type */
466 (zil_replay_func_t
)zvol_replay_err
, /* TX_CREATE */
467 (zil_replay_func_t
)zvol_replay_err
, /* TX_MKDIR */
468 (zil_replay_func_t
)zvol_replay_err
, /* TX_MKXATTR */
469 (zil_replay_func_t
)zvol_replay_err
, /* TX_SYMLINK */
470 (zil_replay_func_t
)zvol_replay_err
, /* TX_REMOVE */
471 (zil_replay_func_t
)zvol_replay_err
, /* TX_RMDIR */
472 (zil_replay_func_t
)zvol_replay_err
, /* TX_LINK */
473 (zil_replay_func_t
)zvol_replay_err
, /* TX_RENAME */
474 (zil_replay_func_t
)zvol_replay_write
, /* TX_WRITE */
475 (zil_replay_func_t
)zvol_replay_err
, /* TX_TRUNCATE */
476 (zil_replay_func_t
)zvol_replay_err
, /* TX_SETATTR */
477 (zil_replay_func_t
)zvol_replay_err
, /* TX_ACL */
481 * zvol_log_write() handles synchronous writes using TX_WRITE ZIL transactions.
483 * We store data in the log buffers if it's small enough.
484 * Otherwise we will later flush the data out via dmu_sync().
486 ssize_t zvol_immediate_write_sz
= 32768;
489 zvol_log_write(zvol_state_t
*zv
, dmu_tx_t
*tx
,
490 uint64_t offset
, uint64_t size
, int sync
)
492 uint32_t blocksize
= zv
->zv_volblocksize
;
493 zilog_t
*zilog
= zv
->zv_zilog
;
495 ssize_t immediate_write_sz
;
497 if (zil_replaying(zilog
, tx
))
500 immediate_write_sz
= (zilog
->zl_logbias
== ZFS_LOGBIAS_THROUGHPUT
)
501 ? 0 : zvol_immediate_write_sz
;
502 slogging
= spa_has_slogs(zilog
->zl_spa
) &&
503 (zilog
->zl_logbias
== ZFS_LOGBIAS_LATENCY
);
509 itx_wr_state_t write_state
;
512 * Unlike zfs_log_write() we can be called with
513 * up to DMU_MAX_ACCESS/2 (5MB) writes.
515 if (blocksize
> immediate_write_sz
&& !slogging
&&
516 size
>= blocksize
&& offset
% blocksize
== 0) {
517 write_state
= WR_INDIRECT
; /* uses dmu_sync */
520 write_state
= WR_COPIED
;
521 len
= MIN(ZIL_MAX_LOG_DATA
, size
);
523 write_state
= WR_NEED_COPY
;
524 len
= MIN(ZIL_MAX_LOG_DATA
, size
);
527 itx
= zil_itx_create(TX_WRITE
, sizeof (*lr
) +
528 (write_state
== WR_COPIED
? len
: 0));
529 lr
= (lr_write_t
*)&itx
->itx_lr
;
530 if (write_state
== WR_COPIED
&& dmu_read(zv
->zv_objset
,
531 ZVOL_OBJ
, offset
, len
, lr
+1, DMU_READ_NO_PREFETCH
) != 0) {
532 zil_itx_destroy(itx
);
533 itx
= zil_itx_create(TX_WRITE
, sizeof (*lr
));
534 lr
= (lr_write_t
*)&itx
->itx_lr
;
535 write_state
= WR_NEED_COPY
;
538 itx
->itx_wr_state
= write_state
;
539 if (write_state
== WR_NEED_COPY
)
541 lr
->lr_foid
= ZVOL_OBJ
;
542 lr
->lr_offset
= offset
;
545 BP_ZERO(&lr
->lr_blkptr
);
547 itx
->itx_private
= zv
;
548 itx
->itx_sync
= sync
;
550 (void) zil_itx_assign(zilog
, itx
, tx
);
558 * Common write path running under the zvol taskq context. This function
559 * is responsible for copying the request structure data in to the DMU and
560 * signaling the request queue with the result of the copy.
563 zvol_write(void *arg
)
565 struct request
*req
= (struct request
*)arg
;
566 struct request_queue
*q
= req
->q
;
567 zvol_state_t
*zv
= q
->queuedata
;
568 uint64_t offset
= blk_rq_pos(req
) << 9;
569 uint64_t size
= blk_rq_bytes(req
);
575 * Annotate this call path with a flag that indicates that it is
576 * unsafe to use KM_SLEEP during memory allocations due to the
577 * potential for a deadlock. KM_PUSHPAGE should be used instead.
579 ASSERT(!(current
->flags
& PF_NOFS
));
580 current
->flags
|= PF_NOFS
;
582 if (req
->cmd_flags
& VDEV_REQ_FLUSH
)
583 zil_commit(zv
->zv_zilog
, ZVOL_OBJ
);
586 * Some requests are just for flush and nothing else.
589 blk_end_request(req
, 0, size
);
593 rl
= zfs_range_lock(&zv
->zv_znode
, offset
, size
, RL_WRITER
);
595 tx
= dmu_tx_create(zv
->zv_objset
);
596 dmu_tx_hold_write(tx
, ZVOL_OBJ
, offset
, size
);
598 /* This will only fail for ENOSPC */
599 error
= dmu_tx_assign(tx
, TXG_WAIT
);
602 zfs_range_unlock(rl
);
603 blk_end_request(req
, -error
, size
);
607 error
= dmu_write_req(zv
->zv_objset
, ZVOL_OBJ
, req
, tx
);
609 zvol_log_write(zv
, tx
, offset
, size
,
610 req
->cmd_flags
& VDEV_REQ_FUA
);
613 zfs_range_unlock(rl
);
615 if ((req
->cmd_flags
& VDEV_REQ_FUA
) ||
616 zv
->zv_objset
->os_sync
== ZFS_SYNC_ALWAYS
)
617 zil_commit(zv
->zv_zilog
, ZVOL_OBJ
);
619 blk_end_request(req
, -error
, size
);
621 current
->flags
&= ~PF_NOFS
;
624 #ifdef HAVE_BLK_QUEUE_DISCARD
626 zvol_discard(void *arg
)
628 struct request
*req
= (struct request
*)arg
;
629 struct request_queue
*q
= req
->q
;
630 zvol_state_t
*zv
= q
->queuedata
;
631 uint64_t start
= blk_rq_pos(req
) << 9;
632 uint64_t end
= start
+ blk_rq_bytes(req
);
637 * Annotate this call path with a flag that indicates that it is
638 * unsafe to use KM_SLEEP during memory allocations due to the
639 * potential for a deadlock. KM_PUSHPAGE should be used instead.
641 ASSERT(!(current
->flags
& PF_NOFS
));
642 current
->flags
|= PF_NOFS
;
644 if (end
> zv
->zv_volsize
) {
645 blk_end_request(req
, -EIO
, blk_rq_bytes(req
));
650 * Align the request to volume block boundaries. If we don't,
651 * then this will force dnode_free_range() to zero out the
652 * unaligned parts, which is slow (read-modify-write) and
653 * useless since we are not freeing any space by doing so.
655 start
= P2ROUNDUP(start
, zv
->zv_volblocksize
);
656 end
= P2ALIGN(end
, zv
->zv_volblocksize
);
659 blk_end_request(req
, 0, blk_rq_bytes(req
));
663 rl
= zfs_range_lock(&zv
->zv_znode
, start
, end
- start
, RL_WRITER
);
665 error
= dmu_free_long_range(zv
->zv_objset
, ZVOL_OBJ
, start
, end
- start
);
668 * TODO: maybe we should add the operation to the log.
671 zfs_range_unlock(rl
);
673 blk_end_request(req
, -error
, blk_rq_bytes(req
));
675 current
->flags
&= ~PF_NOFS
;
677 #endif /* HAVE_BLK_QUEUE_DISCARD */
680 * Common read path running under the zvol taskq context. This function
681 * is responsible for copying the requested data out of the DMU and in to
682 * a linux request structure. It then must signal the request queue with
683 * an error code describing the result of the copy.
688 struct request
*req
= (struct request
*)arg
;
689 struct request_queue
*q
= req
->q
;
690 zvol_state_t
*zv
= q
->queuedata
;
691 uint64_t offset
= blk_rq_pos(req
) << 9;
692 uint64_t size
= blk_rq_bytes(req
);
697 blk_end_request(req
, 0, size
);
701 rl
= zfs_range_lock(&zv
->zv_znode
, offset
, size
, RL_READER
);
703 error
= dmu_read_req(zv
->zv_objset
, ZVOL_OBJ
, req
);
705 zfs_range_unlock(rl
);
707 /* convert checksum errors into IO errors */
709 error
= SET_ERROR(EIO
);
711 blk_end_request(req
, -error
, size
);
715 * Request will be added back to the request queue and retried if
716 * it cannot be immediately dispatched to the taskq for handling
719 zvol_dispatch(task_func_t func
, struct request
*req
)
721 if (!taskq_dispatch(zvol_taskq
, func
, (void *)req
, TQ_NOSLEEP
))
722 blk_requeue_request(req
->q
, req
);
726 * Common request path. Rather than registering a custom make_request()
727 * function we use the generic Linux version. This is done because it allows
728 * us to easily merge read requests which would otherwise we performed
729 * synchronously by the DMU. This is less critical in write case where the
730 * DMU will perform the correct merging within a transaction group. Using
731 * the generic make_request() also let's use leverage the fact that the
732 * elevator with ensure correct ordering in regards to barrior IOs. On
733 * the downside it means that in the write case we end up doing request
734 * merging twice once in the elevator and once in the DMU.
736 * The request handler is called under a spin lock so all the real work
737 * is handed off to be done in the context of the zvol taskq. This function
738 * simply performs basic request sanity checking and hands off the request.
741 zvol_request(struct request_queue
*q
)
743 zvol_state_t
*zv
= q
->queuedata
;
747 while ((req
= blk_fetch_request(q
)) != NULL
) {
748 size
= blk_rq_bytes(req
);
750 if (size
!= 0 && blk_rq_pos(req
) + blk_rq_sectors(req
) >
751 get_capacity(zv
->zv_disk
)) {
753 "%s: bad access: block=%llu, count=%lu\n",
754 req
->rq_disk
->disk_name
,
755 (long long unsigned)blk_rq_pos(req
),
756 (long unsigned)blk_rq_sectors(req
));
757 __blk_end_request(req
, -EIO
, size
);
761 if (!blk_fs_request(req
)) {
762 printk(KERN_INFO
"%s: non-fs cmd\n",
763 req
->rq_disk
->disk_name
);
764 __blk_end_request(req
, -EIO
, size
);
768 switch (rq_data_dir(req
)) {
770 zvol_dispatch(zvol_read
, req
);
773 if (unlikely(zv
->zv_flags
& ZVOL_RDONLY
)) {
774 __blk_end_request(req
, -EROFS
, size
);
778 #ifdef HAVE_BLK_QUEUE_DISCARD
779 if (req
->cmd_flags
& VDEV_REQ_DISCARD
) {
780 zvol_dispatch(zvol_discard
, req
);
783 #endif /* HAVE_BLK_QUEUE_DISCARD */
785 zvol_dispatch(zvol_write
, req
);
788 printk(KERN_INFO
"%s: unknown cmd: %d\n",
789 req
->rq_disk
->disk_name
, (int)rq_data_dir(req
));
790 __blk_end_request(req
, -EIO
, size
);
797 zvol_get_done(zgd_t
*zgd
, int error
)
800 dmu_buf_rele(zgd
->zgd_db
, zgd
);
802 zfs_range_unlock(zgd
->zgd_rl
);
804 if (error
== 0 && zgd
->zgd_bp
)
805 zil_add_block(zgd
->zgd_zilog
, zgd
->zgd_bp
);
807 kmem_free(zgd
, sizeof (zgd_t
));
811 * Get data to generate a TX_WRITE intent log record.
814 zvol_get_data(void *arg
, lr_write_t
*lr
, char *buf
, zio_t
*zio
)
816 zvol_state_t
*zv
= arg
;
817 objset_t
*os
= zv
->zv_objset
;
818 uint64_t object
= ZVOL_OBJ
;
819 uint64_t offset
= lr
->lr_offset
;
820 uint64_t size
= lr
->lr_length
;
821 blkptr_t
*bp
= &lr
->lr_blkptr
;
829 zgd
= (zgd_t
*)kmem_zalloc(sizeof (zgd_t
), KM_PUSHPAGE
);
830 zgd
->zgd_zilog
= zv
->zv_zilog
;
831 zgd
->zgd_rl
= zfs_range_lock(&zv
->zv_znode
, offset
, size
, RL_READER
);
834 * Write records come in two flavors: immediate and indirect.
835 * For small writes it's cheaper to store the data with the
836 * log record (immediate); for large writes it's cheaper to
837 * sync the data and get a pointer to it (indirect) so that
838 * we don't have to write the data twice.
840 if (buf
!= NULL
) { /* immediate write */
841 error
= dmu_read(os
, object
, offset
, size
, buf
,
842 DMU_READ_NO_PREFETCH
);
844 size
= zv
->zv_volblocksize
;
845 offset
= P2ALIGN_TYPED(offset
, size
, uint64_t);
846 error
= dmu_buf_hold(os
, object
, offset
, zgd
, &db
,
847 DMU_READ_NO_PREFETCH
);
849 blkptr_t
*obp
= dmu_buf_get_blkptr(db
);
851 ASSERT(BP_IS_HOLE(bp
));
856 zgd
->zgd_bp
= &lr
->lr_blkptr
;
859 ASSERT(db
->db_offset
== offset
);
860 ASSERT(db
->db_size
== size
);
862 error
= dmu_sync(zio
, lr
->lr_common
.lrc_txg
,
870 zvol_get_done(zgd
, error
);
876 * The zvol_state_t's are inserted in increasing MINOR(dev_t) order.
879 zvol_insert(zvol_state_t
*zv_insert
)
881 zvol_state_t
*zv
= NULL
;
883 ASSERT(MUTEX_HELD(&zvol_state_lock
));
884 ASSERT3U(MINOR(zv_insert
->zv_dev
) & ZVOL_MINOR_MASK
, ==, 0);
885 for (zv
= list_head(&zvol_state_list
); zv
!= NULL
;
886 zv
= list_next(&zvol_state_list
, zv
)) {
887 if (MINOR(zv
->zv_dev
) > MINOR(zv_insert
->zv_dev
))
891 list_insert_before(&zvol_state_list
, zv
, zv_insert
);
895 * Simply remove the zvol from to list of zvols.
898 zvol_remove(zvol_state_t
*zv_remove
)
900 ASSERT(MUTEX_HELD(&zvol_state_lock
));
901 list_remove(&zvol_state_list
, zv_remove
);
905 zvol_first_open(zvol_state_t
*zv
)
914 * In all other cases the spa_namespace_lock is taken before the
915 * bdev->bd_mutex lock. But in this case the Linux __blkdev_get()
916 * function calls fops->open() with the bdev->bd_mutex lock held.
918 * To avoid a potential lock inversion deadlock we preemptively
919 * try to take the spa_namespace_lock(). Normally it will not
920 * be contended and this is safe because spa_open_common() handles
921 * the case where the caller already holds the spa_namespace_lock.
923 * When it is contended we risk a lock inversion if we were to
924 * block waiting for the lock. Luckily, the __blkdev_get()
925 * function allows us to return -ERESTARTSYS which will result in
926 * bdev->bd_mutex being dropped, reacquired, and fops->open() being
927 * called again. This process can be repeated safely until both
928 * locks are acquired.
930 if (!mutex_owned(&spa_namespace_lock
)) {
931 locked
= mutex_tryenter(&spa_namespace_lock
);
933 return (-SET_ERROR(ERESTARTSYS
));
936 /* lie and say we're read-only */
937 error
= dmu_objset_own(zv
->zv_name
, DMU_OST_ZVOL
, 1, zvol_tag
, &os
);
941 error
= zap_lookup(os
, ZVOL_ZAP_OBJ
, "size", 8, 1, &volsize
);
943 dmu_objset_disown(os
, zvol_tag
);
948 error
= dmu_bonus_hold(os
, ZVOL_OBJ
, zvol_tag
, &zv
->zv_dbuf
);
950 dmu_objset_disown(os
, zvol_tag
);
954 set_capacity(zv
->zv_disk
, volsize
>> 9);
955 zv
->zv_volsize
= volsize
;
956 zv
->zv_zilog
= zil_open(os
, zvol_get_data
);
958 VERIFY(dsl_prop_get_integer(zv
->zv_name
, "readonly", &ro
, NULL
) == 0);
959 if (ro
|| dmu_objset_is_snapshot(os
) ||
960 !spa_writeable(dmu_objset_spa(os
))) {
961 set_disk_ro(zv
->zv_disk
, 1);
962 zv
->zv_flags
|= ZVOL_RDONLY
;
964 set_disk_ro(zv
->zv_disk
, 0);
965 zv
->zv_flags
&= ~ZVOL_RDONLY
;
970 mutex_exit(&spa_namespace_lock
);
976 zvol_last_close(zvol_state_t
*zv
)
978 zil_close(zv
->zv_zilog
);
981 dmu_buf_rele(zv
->zv_dbuf
, zvol_tag
);
987 if (dsl_dataset_is_dirty(dmu_objset_ds(zv
->zv_objset
)) &&
988 !(zv
->zv_flags
& ZVOL_RDONLY
))
989 txg_wait_synced(dmu_objset_pool(zv
->zv_objset
), 0);
990 (void) dmu_objset_evict_dbufs(zv
->zv_objset
);
992 dmu_objset_disown(zv
->zv_objset
, zvol_tag
);
993 zv
->zv_objset
= NULL
;
997 zvol_open(struct block_device
*bdev
, fmode_t flag
)
999 zvol_state_t
*zv
= bdev
->bd_disk
->private_data
;
1000 int error
= 0, drop_mutex
= 0;
1003 * If the caller is already holding the mutex do not take it
1004 * again, this will happen as part of zvol_create_minor().
1005 * Once add_disk() is called the device is live and the kernel
1006 * will attempt to open it to read the partition information.
1008 if (!mutex_owned(&zvol_state_lock
)) {
1009 mutex_enter(&zvol_state_lock
);
1013 ASSERT3P(zv
, !=, NULL
);
1015 if (zv
->zv_open_count
== 0) {
1016 error
= zvol_first_open(zv
);
1021 if ((flag
& FMODE_WRITE
) && (zv
->zv_flags
& ZVOL_RDONLY
)) {
1023 goto out_open_count
;
1026 zv
->zv_open_count
++;
1029 if (zv
->zv_open_count
== 0)
1030 zvol_last_close(zv
);
1034 mutex_exit(&zvol_state_lock
);
1036 check_disk_change(bdev
);
1041 #ifdef HAVE_BLOCK_DEVICE_OPERATIONS_RELEASE_VOID
1046 zvol_release(struct gendisk
*disk
, fmode_t mode
)
1048 zvol_state_t
*zv
= disk
->private_data
;
1051 if (!mutex_owned(&zvol_state_lock
)) {
1052 mutex_enter(&zvol_state_lock
);
1056 ASSERT3P(zv
, !=, NULL
);
1057 ASSERT3U(zv
->zv_open_count
, >, 0);
1058 zv
->zv_open_count
--;
1059 if (zv
->zv_open_count
== 0)
1060 zvol_last_close(zv
);
1063 mutex_exit(&zvol_state_lock
);
1065 #ifndef HAVE_BLOCK_DEVICE_OPERATIONS_RELEASE_VOID
1071 zvol_ioctl(struct block_device
*bdev
, fmode_t mode
,
1072 unsigned int cmd
, unsigned long arg
)
1074 zvol_state_t
*zv
= bdev
->bd_disk
->private_data
;
1078 return (-SET_ERROR(ENXIO
));
1082 zil_commit(zv
->zv_zilog
, ZVOL_OBJ
);
1085 error
= copy_to_user((void *)arg
, zv
->zv_name
, MAXNAMELEN
);
1097 #ifdef CONFIG_COMPAT
1099 zvol_compat_ioctl(struct block_device
*bdev
, fmode_t mode
,
1100 unsigned cmd
, unsigned long arg
)
1102 return zvol_ioctl(bdev
, mode
, cmd
, arg
);
1105 #define zvol_compat_ioctl NULL
1108 static int zvol_media_changed(struct gendisk
*disk
)
1110 zvol_state_t
*zv
= disk
->private_data
;
1112 return zv
->zv_changed
;
1115 static int zvol_revalidate_disk(struct gendisk
*disk
)
1117 zvol_state_t
*zv
= disk
->private_data
;
1120 set_capacity(zv
->zv_disk
, zv
->zv_volsize
>> 9);
1126 * Provide a simple virtual geometry for legacy compatibility. For devices
1127 * smaller than 1 MiB a small head and sector count is used to allow very
1128 * tiny devices. For devices over 1 Mib a standard head and sector count
1129 * is used to keep the cylinders count reasonable.
1132 zvol_getgeo(struct block_device
*bdev
, struct hd_geometry
*geo
)
1134 zvol_state_t
*zv
= bdev
->bd_disk
->private_data
;
1135 sector_t sectors
= get_capacity(zv
->zv_disk
);
1137 if (sectors
> 2048) {
1146 geo
->cylinders
= sectors
/ (geo
->heads
* geo
->sectors
);
1151 static struct kobject
*
1152 zvol_probe(dev_t dev
, int *part
, void *arg
)
1155 struct kobject
*kobj
;
1157 mutex_enter(&zvol_state_lock
);
1158 zv
= zvol_find_by_dev(dev
);
1159 kobj
= zv
? get_disk(zv
->zv_disk
) : NULL
;
1160 mutex_exit(&zvol_state_lock
);
1165 #ifdef HAVE_BDEV_BLOCK_DEVICE_OPERATIONS
1166 static struct block_device_operations zvol_ops
= {
1168 .release
= zvol_release
,
1169 .ioctl
= zvol_ioctl
,
1170 .compat_ioctl
= zvol_compat_ioctl
,
1171 .media_changed
= zvol_media_changed
,
1172 .revalidate_disk
= zvol_revalidate_disk
,
1173 .getgeo
= zvol_getgeo
,
1174 .owner
= THIS_MODULE
,
1177 #else /* HAVE_BDEV_BLOCK_DEVICE_OPERATIONS */
1180 zvol_open_by_inode(struct inode
*inode
, struct file
*file
)
1182 return zvol_open(inode
->i_bdev
, file
->f_mode
);
1186 zvol_release_by_inode(struct inode
*inode
, struct file
*file
)
1188 return zvol_release(inode
->i_bdev
->bd_disk
, file
->f_mode
);
1192 zvol_ioctl_by_inode(struct inode
*inode
, struct file
*file
,
1193 unsigned int cmd
, unsigned long arg
)
1195 if (file
== NULL
|| inode
== NULL
)
1197 return zvol_ioctl(inode
->i_bdev
, file
->f_mode
, cmd
, arg
);
1200 # ifdef CONFIG_COMPAT
1202 zvol_compat_ioctl_by_inode(struct file
*file
,
1203 unsigned int cmd
, unsigned long arg
)
1207 return zvol_compat_ioctl(file
->f_dentry
->d_inode
->i_bdev
,
1208 file
->f_mode
, cmd
, arg
);
1211 # define zvol_compat_ioctl_by_inode NULL
1214 static struct block_device_operations zvol_ops
= {
1215 .open
= zvol_open_by_inode
,
1216 .release
= zvol_release_by_inode
,
1217 .ioctl
= zvol_ioctl_by_inode
,
1218 .compat_ioctl
= zvol_compat_ioctl_by_inode
,
1219 .media_changed
= zvol_media_changed
,
1220 .revalidate_disk
= zvol_revalidate_disk
,
1221 .getgeo
= zvol_getgeo
,
1222 .owner
= THIS_MODULE
,
1224 #endif /* HAVE_BDEV_BLOCK_DEVICE_OPERATIONS */
1227 * Allocate memory for a new zvol_state_t and setup the required
1228 * request queue and generic disk structures for the block device.
1230 static zvol_state_t
*
1231 zvol_alloc(dev_t dev
, const char *name
)
1236 zv
= kmem_zalloc(sizeof (zvol_state_t
), KM_PUSHPAGE
);
1238 spin_lock_init(&zv
->zv_lock
);
1239 list_link_init(&zv
->zv_next
);
1241 zv
->zv_queue
= blk_init_queue(zvol_request
, &zv
->zv_lock
);
1242 if (zv
->zv_queue
== NULL
)
1245 #ifdef HAVE_ELEVATOR_CHANGE
1246 error
= elevator_change(zv
->zv_queue
, "noop");
1247 #endif /* HAVE_ELEVATOR_CHANGE */
1249 printk("ZFS: Unable to set \"%s\" scheduler for zvol %s: %d\n",
1250 "noop", name
, error
);
1254 #ifdef HAVE_BLK_QUEUE_FLUSH
1255 blk_queue_flush(zv
->zv_queue
, VDEV_REQ_FLUSH
| VDEV_REQ_FUA
);
1257 blk_queue_ordered(zv
->zv_queue
, QUEUE_ORDERED_DRAIN
, NULL
);
1258 #endif /* HAVE_BLK_QUEUE_FLUSH */
1260 zv
->zv_disk
= alloc_disk(ZVOL_MINORS
);
1261 if (zv
->zv_disk
== NULL
)
1264 zv
->zv_queue
->queuedata
= zv
;
1266 zv
->zv_open_count
= 0;
1267 strlcpy(zv
->zv_name
, name
, MAXNAMELEN
);
1269 mutex_init(&zv
->zv_znode
.z_range_lock
, NULL
, MUTEX_DEFAULT
, NULL
);
1270 avl_create(&zv
->zv_znode
.z_range_avl
, zfs_range_compare
,
1271 sizeof (rl_t
), offsetof(rl_t
, r_node
));
1272 zv
->zv_znode
.z_is_zvol
= TRUE
;
1274 zv
->zv_disk
->major
= zvol_major
;
1275 zv
->zv_disk
->first_minor
= (dev
& MINORMASK
);
1276 zv
->zv_disk
->fops
= &zvol_ops
;
1277 zv
->zv_disk
->private_data
= zv
;
1278 zv
->zv_disk
->queue
= zv
->zv_queue
;
1279 snprintf(zv
->zv_disk
->disk_name
, DISK_NAME_LEN
, "%s%d",
1280 ZVOL_DEV_NAME
, (dev
& MINORMASK
));
1285 blk_cleanup_queue(zv
->zv_queue
);
1287 kmem_free(zv
, sizeof (zvol_state_t
));
1293 * Cleanup then free a zvol_state_t which was created by zvol_alloc().
1296 zvol_free(zvol_state_t
*zv
)
1298 avl_destroy(&zv
->zv_znode
.z_range_avl
);
1299 mutex_destroy(&zv
->zv_znode
.z_range_lock
);
1301 del_gendisk(zv
->zv_disk
);
1302 blk_cleanup_queue(zv
->zv_queue
);
1303 put_disk(zv
->zv_disk
);
1305 kmem_free(zv
, sizeof (zvol_state_t
));
1309 __zvol_snapdev_hidden(const char *name
)
1316 parent
= kmem_alloc(MAXPATHLEN
, KM_PUSHPAGE
);
1317 (void) strlcpy(parent
, name
, MAXPATHLEN
);
1319 if ((atp
= strrchr(parent
, '@')) != NULL
) {
1321 error
= dsl_prop_get_integer(parent
, "snapdev", &snapdev
, NULL
);
1322 if ((error
== 0) && (snapdev
== ZFS_SNAPDEV_HIDDEN
))
1323 error
= SET_ERROR(ENODEV
);
1325 kmem_free(parent
, MAXPATHLEN
);
1330 __zvol_create_minor(const char *name
, boolean_t ignore_snapdev
)
1334 dmu_object_info_t
*doi
;
1339 ASSERT(MUTEX_HELD(&zvol_state_lock
));
1341 zv
= zvol_find_by_name(name
);
1343 error
= SET_ERROR(EEXIST
);
1347 if (ignore_snapdev
== B_FALSE
) {
1348 error
= __zvol_snapdev_hidden(name
);
1353 doi
= kmem_alloc(sizeof(dmu_object_info_t
), KM_PUSHPAGE
);
1355 error
= dmu_objset_own(name
, DMU_OST_ZVOL
, B_TRUE
, zvol_tag
, &os
);
1359 error
= dmu_object_info(os
, ZVOL_OBJ
, doi
);
1361 goto out_dmu_objset_disown
;
1363 error
= zap_lookup(os
, ZVOL_ZAP_OBJ
, "size", 8, 1, &volsize
);
1365 goto out_dmu_objset_disown
;
1367 error
= zvol_find_minor(&minor
);
1369 goto out_dmu_objset_disown
;
1371 zv
= zvol_alloc(MKDEV(zvol_major
, minor
), name
);
1373 error
= SET_ERROR(EAGAIN
);
1374 goto out_dmu_objset_disown
;
1377 if (dmu_objset_is_snapshot(os
))
1378 zv
->zv_flags
|= ZVOL_RDONLY
;
1380 zv
->zv_volblocksize
= doi
->doi_data_block_size
;
1381 zv
->zv_volsize
= volsize
;
1384 set_capacity(zv
->zv_disk
, zv
->zv_volsize
>> 9);
1386 blk_queue_max_hw_sectors(zv
->zv_queue
, UINT_MAX
);
1387 blk_queue_max_segments(zv
->zv_queue
, UINT16_MAX
);
1388 blk_queue_max_segment_size(zv
->zv_queue
, UINT_MAX
);
1389 blk_queue_physical_block_size(zv
->zv_queue
, zv
->zv_volblocksize
);
1390 blk_queue_io_opt(zv
->zv_queue
, zv
->zv_volblocksize
);
1391 #ifdef HAVE_BLK_QUEUE_DISCARD
1392 blk_queue_max_discard_sectors(zv
->zv_queue
,
1393 (zvol_max_discard_blocks
* zv
->zv_volblocksize
) >> 9);
1394 blk_queue_discard_granularity(zv
->zv_queue
, zv
->zv_volblocksize
);
1395 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD
, zv
->zv_queue
);
1397 #ifdef HAVE_BLK_QUEUE_NONROT
1398 queue_flag_set_unlocked(QUEUE_FLAG_NONROT
, zv
->zv_queue
);
1401 if (spa_writeable(dmu_objset_spa(os
))) {
1402 if (zil_replay_disable
)
1403 zil_destroy(dmu_objset_zil(os
), B_FALSE
);
1405 zil_replay(os
, zv
, zvol_replay_vector
);
1408 zv
->zv_objset
= NULL
;
1409 out_dmu_objset_disown
:
1410 dmu_objset_disown(os
, zvol_tag
);
1412 kmem_free(doi
, sizeof(dmu_object_info_t
));
1417 add_disk(zv
->zv_disk
);
1424 * Create a block device minor node and setup the linkage between it
1425 * and the specified volume. Once this function returns the block
1426 * device is live and ready for use.
1429 zvol_create_minor(const char *name
)
1433 mutex_enter(&zvol_state_lock
);
1434 error
= __zvol_create_minor(name
, B_FALSE
);
1435 mutex_exit(&zvol_state_lock
);
1441 __zvol_remove_minor(const char *name
)
1445 ASSERT(MUTEX_HELD(&zvol_state_lock
));
1447 zv
= zvol_find_by_name(name
);
1449 return (SET_ERROR(ENXIO
));
1451 if (zv
->zv_open_count
> 0)
1452 return (SET_ERROR(EBUSY
));
1461 * Remove a block device minor node for the specified volume.
1464 zvol_remove_minor(const char *name
)
1468 mutex_enter(&zvol_state_lock
);
1469 error
= __zvol_remove_minor(name
);
1470 mutex_exit(&zvol_state_lock
);
1476 * Rename a block device minor mode for the specified volume.
1479 __zvol_rename_minor(zvol_state_t
*zv
, const char *newname
)
1481 int readonly
= get_disk_ro(zv
->zv_disk
);
1483 ASSERT(MUTEX_HELD(&zvol_state_lock
));
1485 strlcpy(zv
->zv_name
, newname
, sizeof (zv
->zv_name
));
1488 * The block device's read-only state is briefly changed causing
1489 * a KOBJ_CHANGE uevent to be issued. This ensures udev detects
1490 * the name change and fixes the symlinks. This does not change
1491 * ZVOL_RDONLY in zv->zv_flags so the actual read-only state never
1492 * changes. This would normally be done using kobject_uevent() but
1493 * that is a GPL-only symbol which is why we need this workaround.
1495 set_disk_ro(zv
->zv_disk
, !readonly
);
1496 set_disk_ro(zv
->zv_disk
, readonly
);
1500 zvol_create_minors_cb(const char *dsname
, void *arg
)
1502 (void) zvol_create_minor(dsname
);
1508 * Create minors for specified dataset including children and snapshots.
1511 zvol_create_minors(const char *name
)
1515 if (!zvol_inhibit_dev
)
1516 error
= dmu_objset_find((char *)name
, zvol_create_minors_cb
,
1517 NULL
, DS_FIND_CHILDREN
| DS_FIND_SNAPSHOTS
);
1519 return (SET_ERROR(error
));
1523 * Remove minors for specified dataset including children and snapshots.
1526 zvol_remove_minors(const char *name
)
1528 zvol_state_t
*zv
, *zv_next
;
1529 int namelen
= ((name
) ? strlen(name
) : 0);
1531 if (zvol_inhibit_dev
)
1534 mutex_enter(&zvol_state_lock
);
1536 for (zv
= list_head(&zvol_state_list
); zv
!= NULL
; zv
= zv_next
) {
1537 zv_next
= list_next(&zvol_state_list
, zv
);
1539 if (name
== NULL
|| strcmp(zv
->zv_name
, name
) == 0 ||
1540 (strncmp(zv
->zv_name
, name
, namelen
) == 0 &&
1541 zv
->zv_name
[namelen
] == '/')) {
1547 mutex_exit(&zvol_state_lock
);
1551 * Rename minors for specified dataset including children and snapshots.
1554 zvol_rename_minors(const char *oldname
, const char *newname
)
1556 zvol_state_t
*zv
, *zv_next
;
1557 int oldnamelen
, newnamelen
;
1560 if (zvol_inhibit_dev
)
1563 oldnamelen
= strlen(oldname
);
1564 newnamelen
= strlen(newname
);
1565 name
= kmem_alloc(MAXNAMELEN
, KM_PUSHPAGE
);
1567 mutex_enter(&zvol_state_lock
);
1569 for (zv
= list_head(&zvol_state_list
); zv
!= NULL
; zv
= zv_next
) {
1570 zv_next
= list_next(&zvol_state_list
, zv
);
1572 if (strcmp(zv
->zv_name
, oldname
) == 0) {
1573 __zvol_rename_minor(zv
, newname
);
1574 } else if (strncmp(zv
->zv_name
, oldname
, oldnamelen
) == 0 &&
1575 (zv
->zv_name
[oldnamelen
] == '/' ||
1576 zv
->zv_name
[oldnamelen
] == '@')) {
1577 snprintf(name
, MAXNAMELEN
, "%s%c%s", newname
,
1578 zv
->zv_name
[oldnamelen
],
1579 zv
->zv_name
+ oldnamelen
+ 1);
1580 __zvol_rename_minor(zv
, name
);
1584 mutex_exit(&zvol_state_lock
);
1586 kmem_free(name
, MAXNAMELEN
);
1590 snapdev_snapshot_changed_cb(const char *dsname
, void *arg
) {
1591 uint64_t snapdev
= *(uint64_t *) arg
;
1593 if (strchr(dsname
, '@') == NULL
)
1597 case ZFS_SNAPDEV_VISIBLE
:
1598 mutex_enter(&zvol_state_lock
);
1599 (void) __zvol_create_minor(dsname
, B_TRUE
);
1600 mutex_exit(&zvol_state_lock
);
1602 case ZFS_SNAPDEV_HIDDEN
:
1603 (void) zvol_remove_minor(dsname
);
1611 zvol_set_snapdev(const char *dsname
, uint64_t snapdev
) {
1612 (void) dmu_objset_find((char *) dsname
, snapdev_snapshot_changed_cb
,
1613 &snapdev
, DS_FIND_SNAPSHOTS
| DS_FIND_CHILDREN
);
1614 /* caller should continue to modify snapdev property */
1624 list_create(&zvol_state_list
, sizeof (zvol_state_t
),
1625 offsetof(zvol_state_t
, zv_next
));
1626 mutex_init(&zvol_state_lock
, NULL
, MUTEX_DEFAULT
, NULL
);
1628 zvol_taskq
= taskq_create(ZVOL_DRIVER
, zvol_threads
, maxclsyspri
,
1629 zvol_threads
, INT_MAX
, TASKQ_PREPOPULATE
);
1630 if (zvol_taskq
== NULL
) {
1631 printk(KERN_INFO
"ZFS: taskq_create() failed\n");
1636 error
= register_blkdev(zvol_major
, ZVOL_DRIVER
);
1638 printk(KERN_INFO
"ZFS: register_blkdev() failed %d\n", error
);
1642 blk_register_region(MKDEV(zvol_major
, 0), 1UL << MINORBITS
,
1643 THIS_MODULE
, zvol_probe
, NULL
, NULL
);
1648 taskq_destroy(zvol_taskq
);
1650 mutex_destroy(&zvol_state_lock
);
1651 list_destroy(&zvol_state_list
);
1659 zvol_remove_minors(NULL
);
1660 blk_unregister_region(MKDEV(zvol_major
, 0), 1UL << MINORBITS
);
1661 unregister_blkdev(zvol_major
, ZVOL_DRIVER
);
1662 taskq_destroy(zvol_taskq
);
1663 mutex_destroy(&zvol_state_lock
);
1664 list_destroy(&zvol_state_list
);
1667 module_param(zvol_inhibit_dev
, uint
, 0644);
1668 MODULE_PARM_DESC(zvol_inhibit_dev
, "Do not create zvol device nodes");
1670 module_param(zvol_major
, uint
, 0444);
1671 MODULE_PARM_DESC(zvol_major
, "Major number for zvol device");
1673 module_param(zvol_threads
, uint
, 0444);
1674 MODULE_PARM_DESC(zvol_threads
, "Number of threads for zvol device");
1676 module_param(zvol_max_discard_blocks
, ulong
, 0444);
1677 MODULE_PARM_DESC(zvol_max_discard_blocks
, "Max number of blocks to discard at once");