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|
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (C) 2008-2010 Lawrence Livermore National Security, LLC.
* Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
* Rewritten for Linux by Brian Behlendorf <behlendorf1@llnl.gov>.
* LLNL-CODE-403049.
* Copyright (c) 2012, 2014 by Delphix. All rights reserved.
*/
#include <sys/zfs_context.h>
#include <sys/spa.h>
#include <sys/vdev_disk.h>
#include <sys/vdev_impl.h>
#include <sys/fs/zfs.h>
#include <sys/zio.h>
#include <sys/sunldi.h>
char *zfs_vdev_scheduler = VDEV_SCHEDULER;
static void *zfs_vdev_holder = VDEV_HOLDER;
/*
* Virtual device vector for disks.
*/
typedef struct dio_request {
struct completion dr_comp; /* Completion for sync IO */
atomic_t dr_ref; /* References */
zio_t *dr_zio; /* Parent ZIO */
int dr_rw; /* Read/Write */
int dr_error; /* Bio error */
int dr_bio_count; /* Count of bio's */
struct bio *dr_bio[0]; /* Attached bio's */
} dio_request_t;
#ifdef HAVE_OPEN_BDEV_EXCLUSIVE
static fmode_t
vdev_bdev_mode(int smode)
{
fmode_t mode = 0;
ASSERT3S(smode & (FREAD | FWRITE), !=, 0);
if (smode & FREAD)
mode |= FMODE_READ;
if (smode & FWRITE)
mode |= FMODE_WRITE;
return (mode);
}
#else
static int
vdev_bdev_mode(int smode)
{
int mode = 0;
ASSERT3S(smode & (FREAD | FWRITE), !=, 0);
if ((smode & FREAD) && !(smode & FWRITE))
mode = MS_RDONLY;
return (mode);
}
#endif /* HAVE_OPEN_BDEV_EXCLUSIVE */
static uint64_t
bdev_capacity(struct block_device *bdev)
{
struct hd_struct *part = bdev->bd_part;
/* The partition capacity referenced by the block device */
if (part)
return (part->nr_sects << 9);
/* Otherwise assume the full device capacity */
return (get_capacity(bdev->bd_disk) << 9);
}
static void
vdev_disk_error(zio_t *zio)
{
#ifdef ZFS_DEBUG
printk("ZFS: zio error=%d type=%d offset=%llu size=%llu "
"flags=%x delay=%llu\n", zio->io_error, zio->io_type,
(u_longlong_t)zio->io_offset, (u_longlong_t)zio->io_size,
zio->io_flags, (u_longlong_t)zio->io_delay);
#endif
}
/*
* Use the Linux 'noop' elevator for zfs managed block devices. This
* strikes the ideal balance by allowing the zfs elevator to do all
* request ordering and prioritization. While allowing the Linux
* elevator to do the maximum front/back merging allowed by the
* physical device. This yields the largest possible requests for
* the device with the lowest total overhead.
*/
static int
vdev_elevator_switch(vdev_t *v, char *elevator)
{
vdev_disk_t *vd = v->vdev_tsd;
struct block_device *bdev = vd->vd_bdev;
struct request_queue *q = bdev_get_queue(bdev);
char *device = bdev->bd_disk->disk_name;
int error;
/*
* Skip devices which are not whole disks (partitions).
* Device-mapper devices are excepted since they may be whole
* disks despite the vdev_wholedisk flag, in which case we can
* and should switch the elevator. If the device-mapper device
* does not have an elevator (i.e. dm-raid, dm-crypt, etc.) the
* "Skip devices without schedulers" check below will fail.
*/
if (!v->vdev_wholedisk && strncmp(device, "dm-", 3) != 0)
return (0);
/* Skip devices without schedulers (loop, ram, dm, etc) */
if (!q->elevator || !blk_queue_stackable(q))
return (0);
/* Leave existing scheduler when set to "none" */
if (strncmp(elevator, "none", 4) && (strlen(elevator) == 4) == 0)
return (0);
#ifdef HAVE_ELEVATOR_CHANGE
error = elevator_change(q, elevator);
#else
/*
* For pre-2.6.36 kernels elevator_change() is not available.
* Therefore we fall back to using a usermodehelper to echo the
* elevator into sysfs; This requires /bin/echo and sysfs to be
* mounted which may not be true early in the boot process.
*/
#define SET_SCHEDULER_CMD \
"exec 0</dev/null " \
" 1>/sys/block/%s/queue/scheduler " \
" 2>/dev/null; " \
"echo %s"
{
char *argv[] = { "/bin/sh", "-c", NULL, NULL };
char *envp[] = { NULL };
argv[2] = kmem_asprintf(SET_SCHEDULER_CMD, device, elevator);
error = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
strfree(argv[2]);
}
#endif /* HAVE_ELEVATOR_CHANGE */
if (error)
printk("ZFS: Unable to set \"%s\" scheduler for %s (%s): %d\n",
elevator, v->vdev_path, device, error);
return (error);
}
/*
* Expanding a whole disk vdev involves invoking BLKRRPART on the
* whole disk device. This poses a problem, because BLKRRPART will
* return EBUSY if one of the disk's partitions is open. That's why
* we have to do it here, just before opening the data partition.
* Unfortunately, BLKRRPART works by dropping all partitions and
* recreating them, which means that for a short time window, all
* /dev/sdxN device files disappear (until udev recreates them).
* This means two things:
* - When we open the data partition just after a BLKRRPART, we
* can't do it using the normal device file path because of the
* obvious race condition with udev. Instead, we use reliable
* kernel APIs to get a handle to the new partition device from
* the whole disk device.
* - Because vdev_disk_open() initially needs to find the device
* using its path, multiple vdev_disk_open() invocations in
* short succession on the same disk with BLKRRPARTs in the
* middle have a high probability of failure (because of the
* race condition with udev). A typical situation where this
* might happen is when the zpool userspace tool does a
* TRYIMPORT immediately followed by an IMPORT. For this
* reason, we only invoke BLKRRPART in the module when strictly
* necessary (zpool online -e case), and rely on userspace to
* do it when possible.
*/
static struct block_device *
vdev_disk_rrpart(const char *path, int mode, vdev_disk_t *vd)
{
#if defined(HAVE_3ARG_BLKDEV_GET) && defined(HAVE_GET_GENDISK)
struct block_device *bdev, *result = ERR_PTR(-ENXIO);
struct gendisk *disk;
int error, partno;
bdev = vdev_bdev_open(path, vdev_bdev_mode(mode), zfs_vdev_holder);
if (IS_ERR(bdev))
return (bdev);
disk = get_gendisk(bdev->bd_dev, &partno);
vdev_bdev_close(bdev, vdev_bdev_mode(mode));
if (disk) {
bdev = bdget(disk_devt(disk));
if (bdev) {
error = blkdev_get(bdev, vdev_bdev_mode(mode), vd);
if (error == 0)
error = ioctl_by_bdev(bdev, BLKRRPART, 0);
vdev_bdev_close(bdev, vdev_bdev_mode(mode));
}
bdev = bdget_disk(disk, partno);
if (bdev) {
error = blkdev_get(bdev,
vdev_bdev_mode(mode) | FMODE_EXCL, vd);
if (error == 0)
result = bdev;
}
put_disk(disk);
}
return (result);
#else
return (ERR_PTR(-EOPNOTSUPP));
#endif /* defined(HAVE_3ARG_BLKDEV_GET) && defined(HAVE_GET_GENDISK) */
}
static int
vdev_disk_open(vdev_t *v, uint64_t *psize, uint64_t *max_psize,
uint64_t *ashift)
{
struct block_device *bdev = ERR_PTR(-ENXIO);
vdev_disk_t *vd;
int mode, block_size;
/* Must have a pathname and it must be absolute. */
if (v->vdev_path == NULL || v->vdev_path[0] != '/') {
v->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
return (EINVAL);
}
/*
* Reopen the device if it's not currently open. Otherwise,
* just update the physical size of the device.
*/
if (v->vdev_tsd != NULL) {
ASSERT(v->vdev_reopening);
vd = v->vdev_tsd;
goto skip_open;
}
vd = kmem_zalloc(sizeof (vdev_disk_t), KM_SLEEP);
if (vd == NULL)
return (ENOMEM);
/*
* Devices are always opened by the path provided at configuration
* time. This means that if the provided path is a udev by-id path
* then drives may be recabled without an issue. If the provided
* path is a udev by-path path, then the physical location information
* will be preserved. This can be critical for more complicated
* configurations where drives are located in specific physical
* locations to maximize the systems tolerence to component failure.
* Alternatively, you can provide your own udev rule to flexibly map
* the drives as you see fit. It is not advised that you use the
* /dev/[hd]d devices which may be reordered due to probing order.
* Devices in the wrong locations will be detected by the higher
* level vdev validation.
*/
mode = spa_mode(v->vdev_spa);
if (v->vdev_wholedisk && v->vdev_expanding)
bdev = vdev_disk_rrpart(v->vdev_path, mode, vd);
if (IS_ERR(bdev))
bdev = vdev_bdev_open(v->vdev_path,
vdev_bdev_mode(mode), zfs_vdev_holder);
if (IS_ERR(bdev)) {
kmem_free(vd, sizeof (vdev_disk_t));
return (-PTR_ERR(bdev));
}
v->vdev_tsd = vd;
vd->vd_bdev = bdev;
skip_open:
/* Determine the physical block size */
block_size = vdev_bdev_block_size(vd->vd_bdev);
/* Clear the nowritecache bit, causes vdev_reopen() to try again. */
v->vdev_nowritecache = B_FALSE;
/* Inform the ZIO pipeline that we are non-rotational */
v->vdev_nonrot = blk_queue_nonrot(bdev_get_queue(vd->vd_bdev));
/* Physical volume size in bytes */
*psize = bdev_capacity(vd->vd_bdev);
/* TODO: report possible expansion size */
*max_psize = *psize;
/* Based on the minimum sector size set the block size */
*ashift = highbit64(MAX(block_size, SPA_MINBLOCKSIZE)) - 1;
/* Try to set the io scheduler elevator algorithm */
(void) vdev_elevator_switch(v, zfs_vdev_scheduler);
return (0);
}
static void
vdev_disk_close(vdev_t *v)
{
vdev_disk_t *vd = v->vdev_tsd;
if (v->vdev_reopening || vd == NULL)
return;
if (vd->vd_bdev != NULL)
vdev_bdev_close(vd->vd_bdev,
vdev_bdev_mode(spa_mode(v->vdev_spa)));
kmem_free(vd, sizeof (vdev_disk_t));
v->vdev_tsd = NULL;
}
static dio_request_t *
vdev_disk_dio_alloc(int bio_count)
{
dio_request_t *dr;
int i;
dr = kmem_zalloc(sizeof (dio_request_t) +
sizeof (struct bio *) * bio_count, KM_SLEEP);
if (dr) {
init_completion(&dr->dr_comp);
atomic_set(&dr->dr_ref, 0);
dr->dr_bio_count = bio_count;
dr->dr_error = 0;
for (i = 0; i < dr->dr_bio_count; i++)
dr->dr_bio[i] = NULL;
}
return (dr);
}
static void
vdev_disk_dio_free(dio_request_t *dr)
{
int i;
for (i = 0; i < dr->dr_bio_count; i++)
if (dr->dr_bio[i])
bio_put(dr->dr_bio[i]);
kmem_free(dr, sizeof (dio_request_t) +
sizeof (struct bio *) * dr->dr_bio_count);
}
static int
vdev_disk_dio_is_sync(dio_request_t *dr)
{
#ifdef HAVE_BIO_RW_SYNC
/* BIO_RW_SYNC preferred interface from 2.6.12-2.6.29 */
return (dr->dr_rw & (1 << BIO_RW_SYNC));
#else
#ifdef HAVE_BIO_RW_SYNCIO
/* BIO_RW_SYNCIO preferred interface from 2.6.30-2.6.35 */
return (dr->dr_rw & (1 << BIO_RW_SYNCIO));
#else
#ifdef HAVE_REQ_SYNC
/* REQ_SYNC preferred interface from 2.6.36-2.6.xx */
return (dr->dr_rw & REQ_SYNC);
#else
#error "Unable to determine bio sync flag"
#endif /* HAVE_REQ_SYNC */
#endif /* HAVE_BIO_RW_SYNC */
#endif /* HAVE_BIO_RW_SYNCIO */
}
static void
vdev_disk_dio_get(dio_request_t *dr)
{
atomic_inc(&dr->dr_ref);
}
static int
vdev_disk_dio_put(dio_request_t *dr)
{
int rc = atomic_dec_return(&dr->dr_ref);
/*
* Free the dio_request when the last reference is dropped and
* ensure zio_interpret is called only once with the correct zio
*/
if (rc == 0) {
zio_t *zio = dr->dr_zio;
int error = dr->dr_error;
vdev_disk_dio_free(dr);
if (zio) {
zio->io_delay = jiffies_64 - zio->io_delay;
zio->io_error = error;
ASSERT3S(zio->io_error, >=, 0);
if (zio->io_error)
vdev_disk_error(zio);
zio_interrupt(zio);
}
}
return (rc);
}
BIO_END_IO_PROTO(vdev_disk_physio_completion, bio, error)
{
dio_request_t *dr = bio->bi_private;
int rc;
if (dr->dr_error == 0) {
#ifdef HAVE_1ARG_BIO_END_IO_T
dr->dr_error = -(bio->bi_error);
#else
if (error)
dr->dr_error = -(error);
else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
dr->dr_error = EIO;
#endif
}
/* Drop reference aquired by __vdev_disk_physio */
rc = vdev_disk_dio_put(dr);
/* Wake up synchronous waiter this is the last outstanding bio */
if ((rc == 1) && vdev_disk_dio_is_sync(dr))
complete(&dr->dr_comp);
}
static inline unsigned long
bio_nr_pages(void *bio_ptr, unsigned int bio_size)
{
return ((((unsigned long)bio_ptr + bio_size + PAGE_SIZE - 1) >>
PAGE_SHIFT) - ((unsigned long)bio_ptr >> PAGE_SHIFT));
}
static unsigned int
bio_map(struct bio *bio, void *bio_ptr, unsigned int bio_size)
{
unsigned int offset, size, i;
struct page *page;
offset = offset_in_page(bio_ptr);
for (i = 0; i < bio->bi_max_vecs; i++) {
size = PAGE_SIZE - offset;
if (bio_size <= 0)
break;
if (size > bio_size)
size = bio_size;
if (is_vmalloc_addr(bio_ptr))
page = vmalloc_to_page(bio_ptr);
else
page = virt_to_page(bio_ptr);
/*
* Some network related block device uses tcp_sendpage, which
* doesn't behave well when using 0-count page, this is a
* safety net to catch them.
*/
ASSERT3S(page_count(page), >, 0);
if (bio_add_page(bio, page, size, offset) != size)
break;
bio_ptr += size;
bio_size -= size;
offset = 0;
}
return (bio_size);
}
static inline void
vdev_submit_bio(int rw, struct bio *bio)
{
#ifdef HAVE_CURRENT_BIO_TAIL
struct bio **bio_tail = current->bio_tail;
current->bio_tail = NULL;
submit_bio(rw, bio);
current->bio_tail = bio_tail;
#else
struct bio_list *bio_list = current->bio_list;
current->bio_list = NULL;
submit_bio(rw, bio);
current->bio_list = bio_list;
#endif
}
static int
__vdev_disk_physio(struct block_device *bdev, zio_t *zio, caddr_t kbuf_ptr,
size_t kbuf_size, uint64_t kbuf_offset, int flags)
{
dio_request_t *dr;
caddr_t bio_ptr;
uint64_t bio_offset;
int bio_size, bio_count = 16;
int i = 0, error = 0;
ASSERT3U(kbuf_offset + kbuf_size, <=, bdev->bd_inode->i_size);
retry:
dr = vdev_disk_dio_alloc(bio_count);
if (dr == NULL)
return (ENOMEM);
if (zio && !(zio->io_flags & (ZIO_FLAG_IO_RETRY | ZIO_FLAG_TRYHARD)))
bio_set_flags_failfast(bdev, &flags);
dr->dr_zio = zio;
dr->dr_rw = flags;
/*
* When the IO size exceeds the maximum bio size for the request
* queue we are forced to break the IO in multiple bio's and wait
* for them all to complete. Ideally, all pool users will set
* their volume block size to match the maximum request size and
* the common case will be one bio per vdev IO request.
*/
bio_ptr = kbuf_ptr;
bio_offset = kbuf_offset;
bio_size = kbuf_size;
for (i = 0; i <= dr->dr_bio_count; i++) {
/* Finished constructing bio's for given buffer */
if (bio_size <= 0)
break;
/*
* By default only 'bio_count' bio's per dio are allowed.
* However, if we find ourselves in a situation where more
* are needed we allocate a larger dio and warn the user.
*/
if (dr->dr_bio_count == i) {
vdev_disk_dio_free(dr);
bio_count *= 2;
goto retry;
}
/* bio_alloc() with __GFP_WAIT never returns NULL */
dr->dr_bio[i] = bio_alloc(GFP_NOIO,
MIN(bio_nr_pages(bio_ptr, bio_size), BIO_MAX_PAGES));
if (unlikely(dr->dr_bio[i] == NULL)) {
vdev_disk_dio_free(dr);
return (ENOMEM);
}
/* Matching put called by vdev_disk_physio_completion */
vdev_disk_dio_get(dr);
dr->dr_bio[i]->bi_bdev = bdev;
BIO_BI_SECTOR(dr->dr_bio[i]) = bio_offset >> 9;
dr->dr_bio[i]->bi_rw = dr->dr_rw;
dr->dr_bio[i]->bi_end_io = vdev_disk_physio_completion;
dr->dr_bio[i]->bi_private = dr;
/* Remaining size is returned to become the new size */
bio_size = bio_map(dr->dr_bio[i], bio_ptr, bio_size);
/* Advance in buffer and construct another bio if needed */
bio_ptr += BIO_BI_SIZE(dr->dr_bio[i]);
bio_offset += BIO_BI_SIZE(dr->dr_bio[i]);
}
/* Extra reference to protect dio_request during vdev_submit_bio */
vdev_disk_dio_get(dr);
if (zio)
zio->io_delay = jiffies_64;
/* Submit all bio's associated with this dio */
for (i = 0; i < dr->dr_bio_count; i++)
if (dr->dr_bio[i])
vdev_submit_bio(dr->dr_rw, dr->dr_bio[i]);
/*
* On synchronous blocking requests we wait for all bio the completion
* callbacks to run. We will be woken when the last callback runs
* for this dio. We are responsible for putting the last dio_request
* reference will in turn put back the last bio references. The
* only synchronous consumer is vdev_disk_read_rootlabel() all other
* IO originating from vdev_disk_io_start() is asynchronous.
*/
if (vdev_disk_dio_is_sync(dr)) {
wait_for_completion(&dr->dr_comp);
error = dr->dr_error;
ASSERT3S(atomic_read(&dr->dr_ref), ==, 1);
}
(void) vdev_disk_dio_put(dr);
return (error);
}
int
vdev_disk_physio(struct block_device *bdev, caddr_t kbuf,
size_t size, uint64_t offset, int flags)
{
bio_set_flags_failfast(bdev, &flags);
return (__vdev_disk_physio(bdev, NULL, kbuf, size, offset, flags));
}
BIO_END_IO_PROTO(vdev_disk_io_flush_completion, bio, rc)
{
zio_t *zio = bio->bi_private;
#ifdef HAVE_1ARG_BIO_END_IO_T
int rc = bio->bi_error;
#endif
zio->io_delay = jiffies_64 - zio->io_delay;
zio->io_error = -rc;
if (rc && (rc == -EOPNOTSUPP))
zio->io_vd->vdev_nowritecache = B_TRUE;
bio_put(bio);
ASSERT3S(zio->io_error, >=, 0);
if (zio->io_error)
vdev_disk_error(zio);
zio_interrupt(zio);
}
static int
vdev_disk_io_flush(struct block_device *bdev, zio_t *zio)
{
struct request_queue *q;
struct bio *bio;
q = bdev_get_queue(bdev);
if (!q)
return (ENXIO);
bio = bio_alloc(GFP_NOIO, 0);
/* bio_alloc() with __GFP_WAIT never returns NULL */
if (unlikely(bio == NULL))
return (ENOMEM);
bio->bi_end_io = vdev_disk_io_flush_completion;
bio->bi_private = zio;
bio->bi_bdev = bdev;
zio->io_delay = jiffies_64;
vdev_submit_bio(VDEV_WRITE_FLUSH_FUA, bio);
invalidate_bdev(bdev);
return (0);
}
static void
vdev_disk_io_start(zio_t *zio)
{
vdev_t *v = zio->io_vd;
vdev_disk_t *vd = v->vdev_tsd;
int flags, error;
switch (zio->io_type) {
case ZIO_TYPE_IOCTL:
if (!vdev_readable(v)) {
zio->io_error = SET_ERROR(ENXIO);
zio_interrupt(zio);
return;
}
switch (zio->io_cmd) {
case DKIOCFLUSHWRITECACHE:
if (zfs_nocacheflush)
break;
if (v->vdev_nowritecache) {
zio->io_error = SET_ERROR(ENOTSUP);
break;
}
error = vdev_disk_io_flush(vd->vd_bdev, zio);
if (error == 0)
return;
zio->io_error = error;
if (error == ENOTSUP)
v->vdev_nowritecache = B_TRUE;
break;
default:
zio->io_error = SET_ERROR(ENOTSUP);
}
zio_execute(zio);
return;
case ZIO_TYPE_WRITE:
if (zio->io_priority == ZIO_PRIORITY_SYNC_WRITE)
flags = WRITE_SYNC;
else
flags = WRITE;
break;
case ZIO_TYPE_READ:
if (zio->io_priority == ZIO_PRIORITY_SYNC_READ)
flags = READ_SYNC;
else
flags = READ;
break;
default:
zio->io_error = SET_ERROR(ENOTSUP);
zio_interrupt(zio);
return;
}
error = __vdev_disk_physio(vd->vd_bdev, zio, zio->io_data,
zio->io_size, zio->io_offset, flags);
if (error) {
zio->io_error = error;
zio_interrupt(zio);
return;
}
}
static void
vdev_disk_io_done(zio_t *zio)
{
/*
* If the device returned EIO, we revalidate the media. If it is
* determined the media has changed this triggers the asynchronous
* removal of the device from the configuration.
*/
if (zio->io_error == EIO) {
vdev_t *v = zio->io_vd;
vdev_disk_t *vd = v->vdev_tsd;
if (check_disk_change(vd->vd_bdev)) {
vdev_bdev_invalidate(vd->vd_bdev);
v->vdev_remove_wanted = B_TRUE;
spa_async_request(zio->io_spa, SPA_ASYNC_REMOVE);
}
}
}
static void
vdev_disk_hold(vdev_t *vd)
{
ASSERT(spa_config_held(vd->vdev_spa, SCL_STATE, RW_WRITER));
/* We must have a pathname, and it must be absolute. */
if (vd->vdev_path == NULL || vd->vdev_path[0] != '/')
return;
/*
* Only prefetch path and devid info if the device has
* never been opened.
*/
if (vd->vdev_tsd != NULL)
return;
/* XXX: Implement me as a vnode lookup for the device */
vd->vdev_name_vp = NULL;
vd->vdev_devid_vp = NULL;
}
static void
vdev_disk_rele(vdev_t *vd)
{
ASSERT(spa_config_held(vd->vdev_spa, SCL_STATE, RW_WRITER));
/* XXX: Implement me as a vnode rele for the device */
}
vdev_ops_t vdev_disk_ops = {
vdev_disk_open,
vdev_disk_close,
vdev_default_asize,
vdev_disk_io_start,
vdev_disk_io_done,
NULL,
vdev_disk_hold,
vdev_disk_rele,
VDEV_TYPE_DISK, /* name of this vdev type */
B_TRUE /* leaf vdev */
};
/*
* Given the root disk device devid or pathname, read the label from
* the device, and construct a configuration nvlist.
*/
int
vdev_disk_read_rootlabel(char *devpath, char *devid, nvlist_t **config)
{
struct block_device *bdev;
vdev_label_t *label;
uint64_t s, size;
int i;
bdev = vdev_bdev_open(devpath, vdev_bdev_mode(FREAD), zfs_vdev_holder);
if (IS_ERR(bdev))
return (-PTR_ERR(bdev));
s = bdev_capacity(bdev);
if (s == 0) {
vdev_bdev_close(bdev, vdev_bdev_mode(FREAD));
return (EIO);
}
size = P2ALIGN_TYPED(s, sizeof (vdev_label_t), uint64_t);
label = vmem_alloc(sizeof (vdev_label_t), KM_SLEEP);
for (i = 0; i < VDEV_LABELS; i++) {
uint64_t offset, state, txg = 0;
/* read vdev label */
offset = vdev_label_offset(size, i, 0);
if (vdev_disk_physio(bdev, (caddr_t)label,
VDEV_SKIP_SIZE + VDEV_PHYS_SIZE, offset, READ_SYNC) != 0)
continue;
if (nvlist_unpack(label->vl_vdev_phys.vp_nvlist,
sizeof (label->vl_vdev_phys.vp_nvlist), config, 0) != 0) {
*config = NULL;
continue;
}
if (nvlist_lookup_uint64(*config, ZPOOL_CONFIG_POOL_STATE,
&state) != 0 || state >= POOL_STATE_DESTROYED) {
nvlist_free(*config);
*config = NULL;
continue;
}
if (nvlist_lookup_uint64(*config, ZPOOL_CONFIG_POOL_TXG,
&txg) != 0 || txg == 0) {
nvlist_free(*config);
*config = NULL;
continue;
}
break;
}
vmem_free(label, sizeof (vdev_label_t));
vdev_bdev_close(bdev, vdev_bdev_mode(FREAD));
return (0);
}
module_param(zfs_vdev_scheduler, charp, 0644);
MODULE_PARM_DESC(zfs_vdev_scheduler, "I/O scheduler");
|