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>.
28 #include <sys/zfs_context.h>
30 #include <sys/vdev_disk.h>
31 #include <sys/vdev_impl.h>
32 #include <sys/fs/zfs.h>
34 #include <sys/sunldi.h>
36 char *zfs_vdev_scheduler
= VDEV_SCHEDULER
;
39 * Virtual device vector for disks.
41 typedef struct dio_request
{
42 struct completion dr_comp
; /* Completion for sync IO */
43 atomic_t dr_ref
; /* References */
44 zio_t
*dr_zio
; /* Parent ZIO */
45 int dr_rw
; /* Read/Write */
46 int dr_error
; /* Bio error */
47 int dr_bio_count
; /* Count of bio's */
48 struct bio
*dr_bio
[0]; /* Attached bio's */
52 #ifdef HAVE_OPEN_BDEV_EXCLUSIVE
54 vdev_bdev_mode(int smode
)
58 ASSERT3S(smode
& (FREAD
| FWRITE
), !=, 0);
70 vdev_bdev_mode(int smode
)
74 ASSERT3S(smode
& (FREAD
| FWRITE
), !=, 0);
76 if ((smode
& FREAD
) && !(smode
& FWRITE
))
81 #endif /* HAVE_OPEN_BDEV_EXCLUSIVE */
84 bdev_capacity(struct block_device
*bdev
)
86 struct hd_struct
*part
= bdev
->bd_part
;
88 /* The partition capacity referenced by the block device */
90 return (part
->nr_sects
<< 9);
92 /* Otherwise assume the full device capacity */
93 return (get_capacity(bdev
->bd_disk
) << 9);
97 vdev_disk_error(zio_t
*zio
)
100 printk("ZFS: zio error=%d type=%d offset=%llu size=%llu "
101 "flags=%x delay=%llu\n", zio
->io_error
, zio
->io_type
,
102 (u_longlong_t
)zio
->io_offset
, (u_longlong_t
)zio
->io_size
,
103 zio
->io_flags
, (u_longlong_t
)zio
->io_delay
);
108 * Use the Linux 'noop' elevator for zfs managed block devices. This
109 * strikes the ideal balance by allowing the zfs elevator to do all
110 * request ordering and prioritization. While allowing the Linux
111 * elevator to do the maximum front/back merging allowed by the
112 * physical device. This yields the largest possible requests for
113 * the device with the lowest total overhead.
115 * Unfortunately we cannot directly call the elevator_switch() function
116 * because it is not exported from the block layer. This means we have
117 * to use the sysfs interface and a user space upcall. Pools will be
118 * automatically imported on module load so we must do this at device
119 * open time from the kernel.
121 #define SET_SCHEDULER_CMD \
122 "exec 0</dev/null " \
123 " 1>/sys/block/%s/queue/scheduler " \
128 vdev_elevator_switch(vdev_t
*v
, char *elevator
)
130 vdev_disk_t
*vd
= v
->vdev_tsd
;
131 struct block_device
*bdev
= vd
->vd_bdev
;
132 struct request_queue
*q
= bdev_get_queue(bdev
);
133 char *device
= bdev
->bd_disk
->disk_name
;
134 char *argv
[] = { "/bin/sh", "-c", NULL
, NULL
};
135 char *envp
[] = { NULL
};
138 /* Skip devices which are not whole disks (partitions) */
139 if (!v
->vdev_wholedisk
)
142 /* Skip devices without schedulers (loop, ram, dm, etc) */
143 if (!q
->elevator
|| !blk_queue_stackable(q
))
146 /* Leave existing scheduler when set to "none" */
147 if (!strncmp(elevator
, "none", 4) && (strlen(elevator
) == 4))
150 argv
[2] = kmem_asprintf(SET_SCHEDULER_CMD
, device
, elevator
);
151 error
= call_usermodehelper(argv
[0], argv
, envp
, 1);
153 printk("ZFS: Unable to set \"%s\" scheduler for %s (%s): %d\n",
154 elevator
, v
->vdev_path
, device
, error
);
162 * Expanding a whole disk vdev involves invoking BLKRRPART on the
163 * whole disk device. This poses a problem, because BLKRRPART will
164 * return EBUSY if one of the disk's partitions is open. That's why
165 * we have to do it here, just before opening the data partition.
166 * Unfortunately, BLKRRPART works by dropping all partitions and
167 * recreating them, which means that for a short time window, all
168 * /dev/sdxN device files disappear (until udev recreates them).
169 * This means two things:
170 * - When we open the data partition just after a BLKRRPART, we
171 * can't do it using the normal device file path because of the
172 * obvious race condition with udev. Instead, we use reliable
173 * kernel APIs to get a handle to the new partition device from
174 * the whole disk device.
175 * - Because vdev_disk_open() initially needs to find the device
176 * using its path, multiple vdev_disk_open() invocations in
177 * short succession on the same disk with BLKRRPARTs in the
178 * middle have a high probability of failure (because of the
179 * race condition with udev). A typical situation where this
180 * might happen is when the zpool userspace tool does a
181 * TRYIMPORT immediately followed by an IMPORT. For this
182 * reason, we only invoke BLKRRPART in the module when strictly
183 * necessary (zpool online -e case), and rely on userspace to
184 * do it when possible.
186 static struct block_device
*
187 vdev_disk_rrpart(const char *path
, int mode
, vdev_disk_t
*vd
)
189 #if defined(HAVE_3ARG_BLKDEV_GET) && defined(HAVE_GET_GENDISK)
190 struct block_device
*bdev
, *result
= ERR_PTR(-ENXIO
);
191 struct gendisk
*disk
;
194 bdev
= vdev_bdev_open(path
, vdev_bdev_mode(mode
), vd
);
198 disk
= get_gendisk(bdev
->bd_dev
, &partno
);
199 vdev_bdev_close(bdev
, vdev_bdev_mode(mode
));
202 bdev
= bdget(disk_devt(disk
));
204 error
= blkdev_get(bdev
, vdev_bdev_mode(mode
), vd
);
206 error
= ioctl_by_bdev(bdev
, BLKRRPART
, 0);
207 vdev_bdev_close(bdev
, vdev_bdev_mode(mode
));
210 bdev
= bdget_disk(disk
, partno
);
212 error
= blkdev_get(bdev
,
213 vdev_bdev_mode(mode
) | FMODE_EXCL
, vd
);
222 return ERR_PTR(-EOPNOTSUPP
);
223 #endif /* defined(HAVE_3ARG_BLKDEV_GET) && defined(HAVE_GET_GENDISK) */
227 vdev_disk_open(vdev_t
*v
, uint64_t *psize
, uint64_t *ashift
)
229 struct block_device
*bdev
= ERR_PTR(-ENXIO
);
231 int mode
, block_size
;
233 /* Must have a pathname and it must be absolute. */
234 if (v
->vdev_path
== NULL
|| v
->vdev_path
[0] != '/') {
235 v
->vdev_stat
.vs_aux
= VDEV_AUX_BAD_LABEL
;
239 vd
= kmem_zalloc(sizeof(vdev_disk_t
), KM_SLEEP
);
244 * Devices are always opened by the path provided at configuration
245 * time. This means that if the provided path is a udev by-id path
246 * then drives may be recabled without an issue. If the provided
247 * path is a udev by-path path then the physical location information
248 * will be preserved. This can be critical for more complicated
249 * configurations where drives are located in specific physical
250 * locations to maximize the systems tolerence to component failure.
251 * Alternately you can provide your own udev rule to flexibly map
252 * the drives as you see fit. It is not advised that you use the
253 * /dev/[hd]d devices which may be reorder due to probing order.
254 * Devices in the wrong locations will be detected by the higher
255 * level vdev validation.
257 mode
= spa_mode(v
->vdev_spa
);
258 if (v
->vdev_wholedisk
&& v
->vdev_expanding
)
259 bdev
= vdev_disk_rrpart(v
->vdev_path
, mode
, vd
);
261 bdev
= vdev_bdev_open(v
->vdev_path
, vdev_bdev_mode(mode
), vd
);
263 kmem_free(vd
, sizeof(vdev_disk_t
));
264 return -PTR_ERR(bdev
);
269 block_size
= vdev_bdev_block_size(bdev
);
271 /* We think the wholedisk property should always be set when this
272 * function is called. ASSERT here so if any legitimate cases exist
273 * where it's not set, we'll find them during debugging. If we never
274 * hit the ASSERT, this and the following conditional statement can be
276 ASSERT3S(v
->vdev_wholedisk
, !=, -1ULL);
278 /* The wholedisk property was initialized to -1 in vdev_alloc() if it
279 * was unspecified. In that case, check if this is a whole device.
280 * When bdev->bd_contains == bdev we have a whole device and not simply
282 if (v
->vdev_wholedisk
== -1ULL)
283 v
->vdev_wholedisk
= (bdev
->bd_contains
== bdev
);
285 /* Clear the nowritecache bit, causes vdev_reopen() to try again. */
286 v
->vdev_nowritecache
= B_FALSE
;
288 /* Physical volume size in bytes */
289 *psize
= bdev_capacity(bdev
);
291 /* Based on the minimum sector size set the block size */
292 *ashift
= highbit(MAX(block_size
, SPA_MINBLOCKSIZE
)) - 1;
294 /* Try to set the io scheduler elevator algorithm */
295 (void) vdev_elevator_switch(v
, zfs_vdev_scheduler
);
301 vdev_disk_close(vdev_t
*v
)
303 vdev_disk_t
*vd
= v
->vdev_tsd
;
308 if (vd
->vd_bdev
!= NULL
)
309 vdev_bdev_close(vd
->vd_bdev
,
310 vdev_bdev_mode(spa_mode(v
->vdev_spa
)));
312 kmem_free(vd
, sizeof(vdev_disk_t
));
316 static dio_request_t
*
317 vdev_disk_dio_alloc(int bio_count
)
322 dr
= kmem_zalloc(sizeof(dio_request_t
) +
323 sizeof(struct bio
*) * bio_count
, KM_SLEEP
);
325 init_completion(&dr
->dr_comp
);
326 atomic_set(&dr
->dr_ref
, 0);
327 dr
->dr_bio_count
= bio_count
;
330 for (i
= 0; i
< dr
->dr_bio_count
; i
++)
331 dr
->dr_bio
[i
] = NULL
;
338 vdev_disk_dio_free(dio_request_t
*dr
)
342 for (i
= 0; i
< dr
->dr_bio_count
; i
++)
344 bio_put(dr
->dr_bio
[i
]);
346 kmem_free(dr
, sizeof(dio_request_t
) +
347 sizeof(struct bio
*) * dr
->dr_bio_count
);
351 vdev_disk_dio_is_sync(dio_request_t
*dr
)
353 #ifdef HAVE_BIO_RW_SYNC
354 /* BIO_RW_SYNC preferred interface from 2.6.12-2.6.29 */
355 return (dr
->dr_rw
& (1 << BIO_RW_SYNC
));
357 # ifdef HAVE_BIO_RW_SYNCIO
358 /* BIO_RW_SYNCIO preferred interface from 2.6.30-2.6.35 */
359 return (dr
->dr_rw
& (1 << BIO_RW_SYNCIO
));
361 # ifdef HAVE_REQ_SYNC
362 /* REQ_SYNC preferred interface from 2.6.36-2.6.xx */
363 return (dr
->dr_rw
& REQ_SYNC
);
365 # error "Unable to determine bio sync flag"
366 # endif /* HAVE_REQ_SYNC */
367 # endif /* HAVE_BIO_RW_SYNC */
368 #endif /* HAVE_BIO_RW_SYNCIO */
372 vdev_disk_dio_get(dio_request_t
*dr
)
374 atomic_inc(&dr
->dr_ref
);
378 vdev_disk_dio_put(dio_request_t
*dr
)
380 int rc
= atomic_dec_return(&dr
->dr_ref
);
383 * Free the dio_request when the last reference is dropped and
384 * ensure zio_interpret is called only once with the correct zio
387 zio_t
*zio
= dr
->dr_zio
;
388 int error
= dr
->dr_error
;
390 vdev_disk_dio_free(dr
);
393 zio
->io_delay
= jiffies_to_msecs(
394 jiffies_64
- zio
->io_delay
);
395 zio
->io_error
= error
;
396 ASSERT3S(zio
->io_error
, >=, 0);
398 vdev_disk_error(zio
);
406 BIO_END_IO_PROTO(vdev_disk_physio_completion
, bio
, size
, error
)
408 dio_request_t
*dr
= bio
->bi_private
;
411 /* Fatal error but print some useful debugging before asserting */
413 PANIC("dr == NULL, bio->bi_private == NULL\n"
414 "bi_next: %p, bi_flags: %lx, bi_rw: %lu, bi_vcnt: %d\n"
415 "bi_idx: %d, bi_size: %d, bi_end_io: %p, bi_cnt: %d\n",
416 bio
->bi_next
, bio
->bi_flags
, bio
->bi_rw
, bio
->bi_vcnt
,
417 bio
->bi_idx
, bio
->bi_size
, bio
->bi_end_io
,
418 atomic_read(&bio
->bi_cnt
));
420 #ifndef HAVE_2ARGS_BIO_END_IO_T
423 #endif /* HAVE_2ARGS_BIO_END_IO_T */
425 if (error
== 0 && !test_bit(BIO_UPTODATE
, &bio
->bi_flags
))
428 if (dr
->dr_error
== 0)
429 dr
->dr_error
= -error
;
431 /* Drop reference aquired by __vdev_disk_physio */
432 rc
= vdev_disk_dio_put(dr
);
434 /* Wake up synchronous waiter this is the last outstanding bio */
435 if ((rc
== 1) && vdev_disk_dio_is_sync(dr
))
436 complete(&dr
->dr_comp
);
438 BIO_END_IO_RETURN(0);
441 static inline unsigned long
442 bio_nr_pages(void *bio_ptr
, unsigned int bio_size
)
444 return ((((unsigned long)bio_ptr
+ bio_size
+ PAGE_SIZE
- 1) >>
445 PAGE_SHIFT
) - ((unsigned long)bio_ptr
>> PAGE_SHIFT
));
449 bio_map(struct bio
*bio
, void *bio_ptr
, unsigned int bio_size
)
451 unsigned int offset
, size
, i
;
454 offset
= offset_in_page(bio_ptr
);
455 for (i
= 0; i
< bio
->bi_max_vecs
; i
++) {
456 size
= PAGE_SIZE
- offset
;
464 if (kmem_virt(bio_ptr
))
465 page
= vmalloc_to_page(bio_ptr
);
467 page
= virt_to_page(bio_ptr
);
469 if (bio_add_page(bio
, page
, size
, offset
) != size
)
481 __vdev_disk_physio(struct block_device
*bdev
, zio_t
*zio
, caddr_t kbuf_ptr
,
482 size_t kbuf_size
, uint64_t kbuf_offset
, int flags
)
487 int bio_size
, bio_count
= 16;
488 int i
= 0, error
= 0;
490 ASSERT3U(kbuf_offset
+ kbuf_size
, <=, bdev
->bd_inode
->i_size
);
493 dr
= vdev_disk_dio_alloc(bio_count
);
497 if (zio
&& !(zio
->io_flags
& (ZIO_FLAG_IO_RETRY
| ZIO_FLAG_TRYHARD
)))
498 bio_set_flags_failfast(bdev
, &flags
);
504 * When the IO size exceeds the maximum bio size for the request
505 * queue we are forced to break the IO in multiple bio's and wait
506 * for them all to complete. Ideally, all pool users will set
507 * their volume block size to match the maximum request size and
508 * the common case will be one bio per vdev IO request.
511 bio_offset
= kbuf_offset
;
512 bio_size
= kbuf_size
;
513 for (i
= 0; i
<= dr
->dr_bio_count
; i
++) {
515 /* Finished constructing bio's for given buffer */
520 * By default only 'bio_count' bio's per dio are allowed.
521 * However, if we find ourselves in a situation where more
522 * are needed we allocate a larger dio and warn the user.
524 if (dr
->dr_bio_count
== i
) {
525 vdev_disk_dio_free(dr
);
527 printk("WARNING: Resized bio's/dio to %d\n",bio_count
);
531 dr
->dr_bio
[i
] = bio_alloc(GFP_NOIO
,
532 bio_nr_pages(bio_ptr
, bio_size
));
533 if (dr
->dr_bio
[i
] == NULL
) {
534 vdev_disk_dio_free(dr
);
538 /* Matching put called by vdev_disk_physio_completion */
539 vdev_disk_dio_get(dr
);
541 dr
->dr_bio
[i
]->bi_bdev
= bdev
;
542 dr
->dr_bio
[i
]->bi_sector
= bio_offset
>> 9;
543 dr
->dr_bio
[i
]->bi_rw
= dr
->dr_rw
;
544 dr
->dr_bio
[i
]->bi_end_io
= vdev_disk_physio_completion
;
545 dr
->dr_bio
[i
]->bi_private
= dr
;
547 /* Remaining size is returned to become the new size */
548 bio_size
= bio_map(dr
->dr_bio
[i
], bio_ptr
, bio_size
);
550 /* Advance in buffer and construct another bio if needed */
551 bio_ptr
+= dr
->dr_bio
[i
]->bi_size
;
552 bio_offset
+= dr
->dr_bio
[i
]->bi_size
;
555 /* Extra reference to protect dio_request during submit_bio */
556 vdev_disk_dio_get(dr
);
558 zio
->io_delay
= jiffies_64
;
560 /* Submit all bio's associated with this dio */
561 for (i
= 0; i
< dr
->dr_bio_count
; i
++)
563 submit_bio(dr
->dr_rw
, dr
->dr_bio
[i
]);
566 * On synchronous blocking requests we wait for all bio the completion
567 * callbacks to run. We will be woken when the last callback runs
568 * for this dio. We are responsible for putting the last dio_request
569 * reference will in turn put back the last bio references. The
570 * only synchronous consumer is vdev_disk_read_rootlabel() all other
571 * IO originating from vdev_disk_io_start() is asynchronous.
573 if (vdev_disk_dio_is_sync(dr
)) {
574 wait_for_completion(&dr
->dr_comp
);
575 error
= dr
->dr_error
;
576 ASSERT3S(atomic_read(&dr
->dr_ref
), ==, 1);
579 (void)vdev_disk_dio_put(dr
);
585 vdev_disk_physio(struct block_device
*bdev
, caddr_t kbuf
,
586 size_t size
, uint64_t offset
, int flags
)
588 bio_set_flags_failfast(bdev
, &flags
);
589 return __vdev_disk_physio(bdev
, NULL
, kbuf
, size
, offset
, flags
);
592 /* 2.6.24 API change */
593 #ifdef HAVE_BIO_EMPTY_BARRIER
594 BIO_END_IO_PROTO(vdev_disk_io_flush_completion
, bio
, size
, rc
)
596 zio_t
*zio
= bio
->bi_private
;
598 zio
->io_delay
= jiffies_to_msecs(jiffies_64
- zio
->io_delay
);
600 if (rc
&& (rc
== -EOPNOTSUPP
))
601 zio
->io_vd
->vdev_nowritecache
= B_TRUE
;
604 ASSERT3S(zio
->io_error
, >=, 0);
606 vdev_disk_error(zio
);
609 BIO_END_IO_RETURN(0);
613 vdev_disk_io_flush(struct block_device
*bdev
, zio_t
*zio
)
615 struct request_queue
*q
;
618 q
= bdev_get_queue(bdev
);
622 bio
= bio_alloc(GFP_KERNEL
, 0);
626 bio
->bi_end_io
= vdev_disk_io_flush_completion
;
627 bio
->bi_private
= zio
;
629 zio
->io_delay
= jiffies_64
;
630 submit_bio(VDEV_WRITE_FLUSH_FUA
, bio
);
636 vdev_disk_io_flush(struct block_device
*bdev
, zio_t
*zio
)
640 #endif /* HAVE_BIO_EMPTY_BARRIER */
643 vdev_disk_io_start(zio_t
*zio
)
645 vdev_t
*v
= zio
->io_vd
;
646 vdev_disk_t
*vd
= v
->vdev_tsd
;
649 switch (zio
->io_type
) {
652 if (!vdev_readable(v
)) {
653 zio
->io_error
= ENXIO
;
654 return ZIO_PIPELINE_CONTINUE
;
657 switch (zio
->io_cmd
) {
658 case DKIOCFLUSHWRITECACHE
:
660 if (zfs_nocacheflush
)
663 if (v
->vdev_nowritecache
) {
664 zio
->io_error
= ENOTSUP
;
668 error
= vdev_disk_io_flush(vd
->vd_bdev
, zio
);
670 return ZIO_PIPELINE_STOP
;
672 zio
->io_error
= error
;
673 if (error
== ENOTSUP
)
674 v
->vdev_nowritecache
= B_TRUE
;
679 zio
->io_error
= ENOTSUP
;
682 return ZIO_PIPELINE_CONTINUE
;
693 zio
->io_error
= ENOTSUP
;
694 return ZIO_PIPELINE_CONTINUE
;
697 error
= __vdev_disk_physio(vd
->vd_bdev
, zio
, zio
->io_data
,
698 zio
->io_size
, zio
->io_offset
, flags
);
700 zio
->io_error
= error
;
701 return ZIO_PIPELINE_CONTINUE
;
704 return ZIO_PIPELINE_STOP
;
708 vdev_disk_io_done(zio_t
*zio
)
711 * If the device returned EIO, we revalidate the media. If it is
712 * determined the media has changed this triggers the asynchronous
713 * removal of the device from the configuration.
715 if (zio
->io_error
== EIO
) {
716 vdev_t
*v
= zio
->io_vd
;
717 vdev_disk_t
*vd
= v
->vdev_tsd
;
719 if (check_disk_change(vd
->vd_bdev
)) {
720 vdev_bdev_invalidate(vd
->vd_bdev
);
721 v
->vdev_remove_wanted
= B_TRUE
;
722 spa_async_request(zio
->io_spa
, SPA_ASYNC_REMOVE
);
728 vdev_disk_hold(vdev_t
*vd
)
730 ASSERT(spa_config_held(vd
->vdev_spa
, SCL_STATE
, RW_WRITER
));
732 /* We must have a pathname, and it must be absolute. */
733 if (vd
->vdev_path
== NULL
|| vd
->vdev_path
[0] != '/')
737 * Only prefetch path and devid info if the device has
740 if (vd
->vdev_tsd
!= NULL
)
743 /* XXX: Implement me as a vnode lookup for the device */
744 vd
->vdev_name_vp
= NULL
;
745 vd
->vdev_devid_vp
= NULL
;
749 vdev_disk_rele(vdev_t
*vd
)
751 ASSERT(spa_config_held(vd
->vdev_spa
, SCL_STATE
, RW_WRITER
));
753 /* XXX: Implement me as a vnode rele for the device */
756 vdev_ops_t vdev_disk_ops
= {
765 VDEV_TYPE_DISK
, /* name of this vdev type */
766 B_TRUE
/* leaf vdev */
770 * Given the root disk device devid or pathname, read the label from
771 * the device, and construct a configuration nvlist.
774 vdev_disk_read_rootlabel(char *devpath
, char *devid
, nvlist_t
**config
)
776 struct block_device
*bdev
;
781 bdev
= vdev_bdev_open(devpath
, vdev_bdev_mode(FREAD
), NULL
);
783 return -PTR_ERR(bdev
);
785 s
= bdev_capacity(bdev
);
787 vdev_bdev_close(bdev
, vdev_bdev_mode(FREAD
));
791 size
= P2ALIGN_TYPED(s
, sizeof(vdev_label_t
), uint64_t);
792 label
= vmem_alloc(sizeof(vdev_label_t
), KM_SLEEP
);
794 for (i
= 0; i
< VDEV_LABELS
; i
++) {
795 uint64_t offset
, state
, txg
= 0;
797 /* read vdev label */
798 offset
= vdev_label_offset(size
, i
, 0);
799 if (vdev_disk_physio(bdev
, (caddr_t
)label
,
800 VDEV_SKIP_SIZE
+ VDEV_PHYS_SIZE
, offset
, READ_SYNC
) != 0)
803 if (nvlist_unpack(label
->vl_vdev_phys
.vp_nvlist
,
804 sizeof (label
->vl_vdev_phys
.vp_nvlist
), config
, 0) != 0) {
809 if (nvlist_lookup_uint64(*config
, ZPOOL_CONFIG_POOL_STATE
,
810 &state
) != 0 || state
>= POOL_STATE_DESTROYED
) {
811 nvlist_free(*config
);
816 if (nvlist_lookup_uint64(*config
, ZPOOL_CONFIG_POOL_TXG
,
817 &txg
) != 0 || txg
== 0) {
818 nvlist_free(*config
);
826 vmem_free(label
, sizeof(vdev_label_t
));
827 vdev_bdev_close(bdev
, vdev_bdev_mode(FREAD
));
832 module_param(zfs_vdev_scheduler
, charp
, 0644);
833 MODULE_PARM_DESC(zfs_vdev_scheduler
, "I/O scheduler");