freebsd-nq/module/zfs/vdev_mirror.c
Ryan Moeller 6fe3498ca3
Import vdev ashift optimization from FreeBSD
Many modern devices use physical allocation units that are much
larger than the minimum logical allocation size accessible by
external commands. Two prevalent examples of this are 512e disk
drives (512b logical sector, 4K physical sector) and flash devices
(512b logical sector, 4K or larger allocation block size, and 128k
or larger erase block size). Operations that modify less than the
physical sector size result in a costly read-modify-write or garbage
collection sequence on these devices.

Simply exporting the true physical sector of the device to ZFS would
yield optimal performance, but has two serious drawbacks:

 1. Existing pools created with devices that have different logical
    and physical block sizes, but were configured to use the logical
    block size (e.g. because the OS version used for pool construction
    reported the logical block size instead of the physical block
    size) will suddenly find that the vdev allocation size has
    increased. This can be easily tolerated for active members of
    the array, but ZFS would prevent replacement of a vdev with
    another identical device because it now appears that the smaller
    allocation size required by the pool is not supported by the new
    device.

 2. The device's physical block size may be too large to be supported
    by ZFS. The optimal allocation size for the vdev may be quite
    large. For example, a RAID controller may export a vdev that
    requires read-modify-write cycles unless accessed using 64k
    aligned/sized requests. ZFS currently has an 8k minimum block
    size limit.

Reporting both the logical and physical allocation sizes for vdevs
solves these problems. A device may be used so long as the logical
block size is compatible with the configuration. By comparing the
logical and physical block sizes, new configurations can be optimized
and administrators can be notified of any existing pools that are
sub-optimal.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Co-authored-by: Matthew Macy <mmacy@freebsd.org>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes #10619
2020-08-21 12:53:17 -07:00

864 lines
24 KiB
C

/*
* 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 2010 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* Copyright (c) 2012, 2015 by Delphix. All rights reserved.
*/
#include <sys/zfs_context.h>
#include <sys/spa.h>
#include <sys/spa_impl.h>
#include <sys/dsl_pool.h>
#include <sys/dsl_scan.h>
#include <sys/vdev_impl.h>
#include <sys/zio.h>
#include <sys/abd.h>
#include <sys/fs/zfs.h>
/*
* Vdev mirror kstats
*/
static kstat_t *mirror_ksp = NULL;
typedef struct mirror_stats {
kstat_named_t vdev_mirror_stat_rotating_linear;
kstat_named_t vdev_mirror_stat_rotating_offset;
kstat_named_t vdev_mirror_stat_rotating_seek;
kstat_named_t vdev_mirror_stat_non_rotating_linear;
kstat_named_t vdev_mirror_stat_non_rotating_seek;
kstat_named_t vdev_mirror_stat_preferred_found;
kstat_named_t vdev_mirror_stat_preferred_not_found;
} mirror_stats_t;
static mirror_stats_t mirror_stats = {
/* New I/O follows directly the last I/O */
{ "rotating_linear", KSTAT_DATA_UINT64 },
/* New I/O is within zfs_vdev_mirror_rotating_seek_offset of the last */
{ "rotating_offset", KSTAT_DATA_UINT64 },
/* New I/O requires random seek */
{ "rotating_seek", KSTAT_DATA_UINT64 },
/* New I/O follows directly the last I/O (nonrot) */
{ "non_rotating_linear", KSTAT_DATA_UINT64 },
/* New I/O requires random seek (nonrot) */
{ "non_rotating_seek", KSTAT_DATA_UINT64 },
/* Preferred child vdev found */
{ "preferred_found", KSTAT_DATA_UINT64 },
/* Preferred child vdev not found or equal load */
{ "preferred_not_found", KSTAT_DATA_UINT64 },
};
#define MIRROR_STAT(stat) (mirror_stats.stat.value.ui64)
#define MIRROR_INCR(stat, val) atomic_add_64(&MIRROR_STAT(stat), val)
#define MIRROR_BUMP(stat) MIRROR_INCR(stat, 1)
void
vdev_mirror_stat_init(void)
{
mirror_ksp = kstat_create("zfs", 0, "vdev_mirror_stats",
"misc", KSTAT_TYPE_NAMED,
sizeof (mirror_stats) / sizeof (kstat_named_t), KSTAT_FLAG_VIRTUAL);
if (mirror_ksp != NULL) {
mirror_ksp->ks_data = &mirror_stats;
kstat_install(mirror_ksp);
}
}
void
vdev_mirror_stat_fini(void)
{
if (mirror_ksp != NULL) {
kstat_delete(mirror_ksp);
mirror_ksp = NULL;
}
}
/*
* Virtual device vector for mirroring.
*/
typedef struct mirror_child {
vdev_t *mc_vd;
uint64_t mc_offset;
int mc_error;
int mc_load;
uint8_t mc_tried;
uint8_t mc_skipped;
uint8_t mc_speculative;
} mirror_child_t;
typedef struct mirror_map {
int *mm_preferred;
int mm_preferred_cnt;
int mm_children;
boolean_t mm_resilvering;
boolean_t mm_root;
mirror_child_t mm_child[];
} mirror_map_t;
static int vdev_mirror_shift = 21;
/*
* The load configuration settings below are tuned by default for
* the case where all devices are of the same rotational type.
*
* If there is a mixture of rotating and non-rotating media, setting
* zfs_vdev_mirror_non_rotating_seek_inc to 0 may well provide better results
* as it will direct more reads to the non-rotating vdevs which are more likely
* to have a higher performance.
*/
/* Rotating media load calculation configuration. */
static int zfs_vdev_mirror_rotating_inc = 0;
static int zfs_vdev_mirror_rotating_seek_inc = 5;
static int zfs_vdev_mirror_rotating_seek_offset = 1 * 1024 * 1024;
/* Non-rotating media load calculation configuration. */
static int zfs_vdev_mirror_non_rotating_inc = 0;
static int zfs_vdev_mirror_non_rotating_seek_inc = 1;
static inline size_t
vdev_mirror_map_size(int children)
{
return (offsetof(mirror_map_t, mm_child[children]) +
sizeof (int) * children);
}
static inline mirror_map_t *
vdev_mirror_map_alloc(int children, boolean_t resilvering, boolean_t root)
{
mirror_map_t *mm;
mm = kmem_zalloc(vdev_mirror_map_size(children), KM_SLEEP);
mm->mm_children = children;
mm->mm_resilvering = resilvering;
mm->mm_root = root;
mm->mm_preferred = (int *)((uintptr_t)mm +
offsetof(mirror_map_t, mm_child[children]));
return (mm);
}
static void
vdev_mirror_map_free(zio_t *zio)
{
mirror_map_t *mm = zio->io_vsd;
kmem_free(mm, vdev_mirror_map_size(mm->mm_children));
}
static const zio_vsd_ops_t vdev_mirror_vsd_ops = {
.vsd_free = vdev_mirror_map_free,
.vsd_cksum_report = zio_vsd_default_cksum_report
};
static int
vdev_mirror_load(mirror_map_t *mm, vdev_t *vd, uint64_t zio_offset)
{
uint64_t last_offset;
int64_t offset_diff;
int load;
/* All DVAs have equal weight at the root. */
if (mm->mm_root)
return (INT_MAX);
/*
* We don't return INT_MAX if the device is resilvering i.e.
* vdev_resilver_txg != 0 as when tested performance was slightly
* worse overall when resilvering with compared to without.
*/
/* Fix zio_offset for leaf vdevs */
if (vd->vdev_ops->vdev_op_leaf)
zio_offset += VDEV_LABEL_START_SIZE;
/* Standard load based on pending queue length. */
load = vdev_queue_length(vd);
last_offset = vdev_queue_last_offset(vd);
if (vd->vdev_nonrot) {
/* Non-rotating media. */
if (last_offset == zio_offset) {
MIRROR_BUMP(vdev_mirror_stat_non_rotating_linear);
return (load + zfs_vdev_mirror_non_rotating_inc);
}
/*
* Apply a seek penalty even for non-rotating devices as
* sequential I/O's can be aggregated into fewer operations on
* the device, thus avoiding unnecessary per-command overhead
* and boosting performance.
*/
MIRROR_BUMP(vdev_mirror_stat_non_rotating_seek);
return (load + zfs_vdev_mirror_non_rotating_seek_inc);
}
/* Rotating media I/O's which directly follow the last I/O. */
if (last_offset == zio_offset) {
MIRROR_BUMP(vdev_mirror_stat_rotating_linear);
return (load + zfs_vdev_mirror_rotating_inc);
}
/*
* Apply half the seek increment to I/O's within seek offset
* of the last I/O issued to this vdev as they should incur less
* of a seek increment.
*/
offset_diff = (int64_t)(last_offset - zio_offset);
if (ABS(offset_diff) < zfs_vdev_mirror_rotating_seek_offset) {
MIRROR_BUMP(vdev_mirror_stat_rotating_offset);
return (load + (zfs_vdev_mirror_rotating_seek_inc / 2));
}
/* Apply the full seek increment to all other I/O's. */
MIRROR_BUMP(vdev_mirror_stat_rotating_seek);
return (load + zfs_vdev_mirror_rotating_seek_inc);
}
/*
* Avoid inlining the function to keep vdev_mirror_io_start(), which
* is this functions only caller, as small as possible on the stack.
*/
noinline static mirror_map_t *
vdev_mirror_map_init(zio_t *zio)
{
mirror_map_t *mm = NULL;
mirror_child_t *mc;
vdev_t *vd = zio->io_vd;
int c;
if (vd == NULL) {
dva_t *dva = zio->io_bp->blk_dva;
spa_t *spa = zio->io_spa;
dsl_scan_t *scn = spa->spa_dsl_pool->dp_scan;
dva_t dva_copy[SPA_DVAS_PER_BP];
/*
* The sequential scrub code sorts and issues all DVAs
* of a bp separately. Each of these IOs includes all
* original DVA copies so that repairs can be performed
* in the event of an error, but we only actually want
* to check the first DVA since the others will be
* checked by their respective sorted IOs. Only if we
* hit an error will we try all DVAs upon retrying.
*
* Note: This check is safe even if the user switches
* from a legacy scrub to a sequential one in the middle
* of processing, since scn_is_sorted isn't updated until
* all outstanding IOs from the previous scrub pass
* complete.
*/
if ((zio->io_flags & ZIO_FLAG_SCRUB) &&
!(zio->io_flags & ZIO_FLAG_IO_RETRY) &&
dsl_scan_scrubbing(spa->spa_dsl_pool) &&
scn->scn_is_sorted) {
c = 1;
} else {
c = BP_GET_NDVAS(zio->io_bp);
}
/*
* If the pool cannot be written to, then infer that some
* DVAs might be invalid or point to vdevs that do not exist.
* We skip them.
*/
if (!spa_writeable(spa)) {
ASSERT3U(zio->io_type, ==, ZIO_TYPE_READ);
int j = 0;
for (int i = 0; i < c; i++) {
if (zfs_dva_valid(spa, &dva[i], zio->io_bp))
dva_copy[j++] = dva[i];
}
if (j == 0) {
zio->io_vsd = NULL;
zio->io_error = ENXIO;
return (NULL);
}
if (j < c) {
dva = dva_copy;
c = j;
}
}
mm = vdev_mirror_map_alloc(c, B_FALSE, B_TRUE);
for (c = 0; c < mm->mm_children; c++) {
mc = &mm->mm_child[c];
mc->mc_vd = vdev_lookup_top(spa, DVA_GET_VDEV(&dva[c]));
mc->mc_offset = DVA_GET_OFFSET(&dva[c]);
if (mc->mc_vd == NULL) {
kmem_free(mm, vdev_mirror_map_size(
mm->mm_children));
zio->io_vsd = NULL;
zio->io_error = ENXIO;
return (NULL);
}
}
} else {
/*
* If we are resilvering, then we should handle scrub reads
* differently; we shouldn't issue them to the resilvering
* device because it might not have those blocks.
*
* We are resilvering iff:
* 1) We are a replacing vdev (ie our name is "replacing-1" or
* "spare-1" or something like that), and
* 2) The pool is currently being resilvered.
*
* We cannot simply check vd->vdev_resilver_txg, because it's
* not set in this path.
*
* Nor can we just check our vdev_ops; there are cases (such as
* when a user types "zpool replace pool odev spare_dev" and
* spare_dev is in the spare list, or when a spare device is
* automatically used to replace a DEGRADED device) when
* resilvering is complete but both the original vdev and the
* spare vdev remain in the pool. That behavior is intentional.
* It helps implement the policy that a spare should be
* automatically removed from the pool after the user replaces
* the device that originally failed.
*
* If a spa load is in progress, then spa_dsl_pool may be
* uninitialized. But we shouldn't be resilvering during a spa
* load anyway.
*/
boolean_t replacing = (vd->vdev_ops == &vdev_replacing_ops ||
vd->vdev_ops == &vdev_spare_ops) &&
spa_load_state(vd->vdev_spa) == SPA_LOAD_NONE &&
dsl_scan_resilvering(vd->vdev_spa->spa_dsl_pool);
mm = vdev_mirror_map_alloc(vd->vdev_children, replacing,
B_FALSE);
for (c = 0; c < mm->mm_children; c++) {
mc = &mm->mm_child[c];
mc->mc_vd = vd->vdev_child[c];
mc->mc_offset = zio->io_offset;
}
}
zio->io_vsd = mm;
zio->io_vsd_ops = &vdev_mirror_vsd_ops;
return (mm);
}
static int
vdev_mirror_open(vdev_t *vd, uint64_t *asize, uint64_t *max_asize,
uint64_t *logical_ashift, uint64_t *physical_ashift)
{
int numerrors = 0;
int lasterror = 0;
if (vd->vdev_children == 0) {
vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
return (SET_ERROR(EINVAL));
}
vdev_open_children(vd);
for (int c = 0; c < vd->vdev_children; c++) {
vdev_t *cvd = vd->vdev_child[c];
if (cvd->vdev_open_error) {
lasterror = cvd->vdev_open_error;
numerrors++;
continue;
}
*asize = MIN(*asize - 1, cvd->vdev_asize - 1) + 1;
*max_asize = MIN(*max_asize - 1, cvd->vdev_max_asize - 1) + 1;
*logical_ashift = MAX(*logical_ashift, cvd->vdev_ashift);
*physical_ashift = MAX(*physical_ashift,
vd->vdev_physical_ashift);
}
if (numerrors == vd->vdev_children) {
if (vdev_children_are_offline(vd))
vd->vdev_stat.vs_aux = VDEV_AUX_CHILDREN_OFFLINE;
else
vd->vdev_stat.vs_aux = VDEV_AUX_NO_REPLICAS;
return (lasterror);
}
return (0);
}
static void
vdev_mirror_close(vdev_t *vd)
{
for (int c = 0; c < vd->vdev_children; c++)
vdev_close(vd->vdev_child[c]);
}
static void
vdev_mirror_child_done(zio_t *zio)
{
mirror_child_t *mc = zio->io_private;
mc->mc_error = zio->io_error;
mc->mc_tried = 1;
mc->mc_skipped = 0;
}
static void
vdev_mirror_scrub_done(zio_t *zio)
{
mirror_child_t *mc = zio->io_private;
if (zio->io_error == 0) {
zio_t *pio;
zio_link_t *zl = NULL;
mutex_enter(&zio->io_lock);
while ((pio = zio_walk_parents(zio, &zl)) != NULL) {
mutex_enter(&pio->io_lock);
ASSERT3U(zio->io_size, >=, pio->io_size);
abd_copy(pio->io_abd, zio->io_abd, pio->io_size);
mutex_exit(&pio->io_lock);
}
mutex_exit(&zio->io_lock);
}
abd_free(zio->io_abd);
mc->mc_error = zio->io_error;
mc->mc_tried = 1;
mc->mc_skipped = 0;
}
/*
* Check the other, lower-index DVAs to see if they're on the same
* vdev as the child we picked. If they are, use them since they
* are likely to have been allocated from the primary metaslab in
* use at the time, and hence are more likely to have locality with
* single-copy data.
*/
static int
vdev_mirror_dva_select(zio_t *zio, int p)
{
dva_t *dva = zio->io_bp->blk_dva;
mirror_map_t *mm = zio->io_vsd;
int preferred;
int c;
preferred = mm->mm_preferred[p];
for (p--; p >= 0; p--) {
c = mm->mm_preferred[p];
if (DVA_GET_VDEV(&dva[c]) == DVA_GET_VDEV(&dva[preferred]))
preferred = c;
}
return (preferred);
}
static int
vdev_mirror_preferred_child_randomize(zio_t *zio)
{
mirror_map_t *mm = zio->io_vsd;
int p;
if (mm->mm_root) {
p = spa_get_random(mm->mm_preferred_cnt);
return (vdev_mirror_dva_select(zio, p));
}
/*
* To ensure we don't always favour the first matching vdev,
* which could lead to wear leveling issues on SSD's, we
* use the I/O offset as a pseudo random seed into the vdevs
* which have the lowest load.
*/
p = (zio->io_offset >> vdev_mirror_shift) % mm->mm_preferred_cnt;
return (mm->mm_preferred[p]);
}
/*
* Try to find a vdev whose DTL doesn't contain the block we want to read
* preferring vdevs based on determined load.
*
* Try to find a child whose DTL doesn't contain the block we want to read.
* If we can't, try the read on any vdev we haven't already tried.
*/
static int
vdev_mirror_child_select(zio_t *zio)
{
mirror_map_t *mm = zio->io_vsd;
uint64_t txg = zio->io_txg;
int c, lowest_load;
ASSERT(zio->io_bp == NULL || BP_PHYSICAL_BIRTH(zio->io_bp) == txg);
lowest_load = INT_MAX;
mm->mm_preferred_cnt = 0;
for (c = 0; c < mm->mm_children; c++) {
mirror_child_t *mc;
mc = &mm->mm_child[c];
if (mc->mc_tried || mc->mc_skipped)
continue;
if (mc->mc_vd == NULL || !vdev_readable(mc->mc_vd)) {
mc->mc_error = SET_ERROR(ENXIO);
mc->mc_tried = 1; /* don't even try */
mc->mc_skipped = 1;
continue;
}
if (vdev_dtl_contains(mc->mc_vd, DTL_MISSING, txg, 1)) {
mc->mc_error = SET_ERROR(ESTALE);
mc->mc_skipped = 1;
mc->mc_speculative = 1;
continue;
}
mc->mc_load = vdev_mirror_load(mm, mc->mc_vd, mc->mc_offset);
if (mc->mc_load > lowest_load)
continue;
if (mc->mc_load < lowest_load) {
lowest_load = mc->mc_load;
mm->mm_preferred_cnt = 0;
}
mm->mm_preferred[mm->mm_preferred_cnt] = c;
mm->mm_preferred_cnt++;
}
if (mm->mm_preferred_cnt == 1) {
MIRROR_BUMP(vdev_mirror_stat_preferred_found);
return (mm->mm_preferred[0]);
}
if (mm->mm_preferred_cnt > 1) {
MIRROR_BUMP(vdev_mirror_stat_preferred_not_found);
return (vdev_mirror_preferred_child_randomize(zio));
}
/*
* Every device is either missing or has this txg in its DTL.
* Look for any child we haven't already tried before giving up.
*/
for (c = 0; c < mm->mm_children; c++) {
if (!mm->mm_child[c].mc_tried)
return (c);
}
/*
* Every child failed. There's no place left to look.
*/
return (-1);
}
static void
vdev_mirror_io_start(zio_t *zio)
{
mirror_map_t *mm;
mirror_child_t *mc;
int c, children;
mm = vdev_mirror_map_init(zio);
if (mm == NULL) {
ASSERT(!spa_trust_config(zio->io_spa));
ASSERT(zio->io_type == ZIO_TYPE_READ);
zio_execute(zio);
return;
}
if (zio->io_type == ZIO_TYPE_READ) {
if (zio->io_bp != NULL &&
(zio->io_flags & ZIO_FLAG_SCRUB) && !mm->mm_resilvering) {
/*
* For scrubbing reads (if we can verify the
* checksum here, as indicated by io_bp being
* non-NULL) we need to allocate a read buffer for
* each child and issue reads to all children. If
* any child succeeds, it will copy its data into
* zio->io_data in vdev_mirror_scrub_done.
*/
for (c = 0; c < mm->mm_children; c++) {
mc = &mm->mm_child[c];
zio_nowait(zio_vdev_child_io(zio, zio->io_bp,
mc->mc_vd, mc->mc_offset,
abd_alloc_sametype(zio->io_abd,
zio->io_size), zio->io_size,
zio->io_type, zio->io_priority, 0,
vdev_mirror_scrub_done, mc));
}
zio_execute(zio);
return;
}
/*
* For normal reads just pick one child.
*/
c = vdev_mirror_child_select(zio);
children = (c >= 0);
} else {
ASSERT(zio->io_type == ZIO_TYPE_WRITE);
/*
* Writes go to all children.
*/
c = 0;
children = mm->mm_children;
}
while (children--) {
mc = &mm->mm_child[c];
zio_nowait(zio_vdev_child_io(zio, zio->io_bp,
mc->mc_vd, mc->mc_offset, zio->io_abd, zio->io_size,
zio->io_type, zio->io_priority, 0,
vdev_mirror_child_done, mc));
c++;
}
zio_execute(zio);
}
static int
vdev_mirror_worst_error(mirror_map_t *mm)
{
int error[2] = { 0, 0 };
for (int c = 0; c < mm->mm_children; c++) {
mirror_child_t *mc = &mm->mm_child[c];
int s = mc->mc_speculative;
error[s] = zio_worst_error(error[s], mc->mc_error);
}
return (error[0] ? error[0] : error[1]);
}
static void
vdev_mirror_io_done(zio_t *zio)
{
mirror_map_t *mm = zio->io_vsd;
mirror_child_t *mc;
int c;
int good_copies = 0;
int unexpected_errors = 0;
if (mm == NULL)
return;
for (c = 0; c < mm->mm_children; c++) {
mc = &mm->mm_child[c];
if (mc->mc_error) {
if (!mc->mc_skipped)
unexpected_errors++;
} else if (mc->mc_tried) {
good_copies++;
}
}
if (zio->io_type == ZIO_TYPE_WRITE) {
/*
* XXX -- for now, treat partial writes as success.
*
* Now that we support write reallocation, it would be better
* to treat partial failure as real failure unless there are
* no non-degraded top-level vdevs left, and not update DTLs
* if we intend to reallocate.
*/
/* XXPOLICY */
if (good_copies != mm->mm_children) {
/*
* Always require at least one good copy.
*
* For ditto blocks (io_vd == NULL), require
* all copies to be good.
*
* XXX -- for replacing vdevs, there's no great answer.
* If the old device is really dead, we may not even
* be able to access it -- so we only want to
* require good writes to the new device. But if
* the new device turns out to be flaky, we want
* to be able to detach it -- which requires all
* writes to the old device to have succeeded.
*/
if (good_copies == 0 || zio->io_vd == NULL)
zio->io_error = vdev_mirror_worst_error(mm);
}
return;
}
ASSERT(zio->io_type == ZIO_TYPE_READ);
/*
* If we don't have a good copy yet, keep trying other children.
*/
/* XXPOLICY */
if (good_copies == 0 && (c = vdev_mirror_child_select(zio)) != -1) {
ASSERT(c >= 0 && c < mm->mm_children);
mc = &mm->mm_child[c];
zio_vdev_io_redone(zio);
zio_nowait(zio_vdev_child_io(zio, zio->io_bp,
mc->mc_vd, mc->mc_offset, zio->io_abd, zio->io_size,
ZIO_TYPE_READ, zio->io_priority, 0,
vdev_mirror_child_done, mc));
return;
}
/* XXPOLICY */
if (good_copies == 0) {
zio->io_error = vdev_mirror_worst_error(mm);
ASSERT(zio->io_error != 0);
}
if (good_copies && spa_writeable(zio->io_spa) &&
(unexpected_errors ||
(zio->io_flags & ZIO_FLAG_RESILVER) ||
((zio->io_flags & ZIO_FLAG_SCRUB) && mm->mm_resilvering))) {
/*
* Use the good data we have in hand to repair damaged children.
*/
for (c = 0; c < mm->mm_children; c++) {
/*
* Don't rewrite known good children.
* Not only is it unnecessary, it could
* actually be harmful: if the system lost
* power while rewriting the only good copy,
* there would be no good copies left!
*/
mc = &mm->mm_child[c];
if (mc->mc_error == 0) {
if (mc->mc_tried)
continue;
/*
* We didn't try this child. We need to
* repair it if:
* 1. it's a scrub (in which case we have
* tried everything that was healthy)
* - or -
* 2. it's an indirect vdev (in which case
* it could point to any other vdev, which
* might have a bad DTL)
* - or -
* 3. the DTL indicates that this data is
* missing from this vdev
*/
if (!(zio->io_flags & ZIO_FLAG_SCRUB) &&
mc->mc_vd->vdev_ops != &vdev_indirect_ops &&
!vdev_dtl_contains(mc->mc_vd, DTL_PARTIAL,
zio->io_txg, 1))
continue;
mc->mc_error = SET_ERROR(ESTALE);
}
zio_nowait(zio_vdev_child_io(zio, zio->io_bp,
mc->mc_vd, mc->mc_offset,
zio->io_abd, zio->io_size, ZIO_TYPE_WRITE,
zio->io_priority == ZIO_PRIORITY_REBUILD ?
ZIO_PRIORITY_REBUILD : ZIO_PRIORITY_ASYNC_WRITE,
ZIO_FLAG_IO_REPAIR | (unexpected_errors ?
ZIO_FLAG_SELF_HEAL : 0), NULL, NULL));
}
}
}
static void
vdev_mirror_state_change(vdev_t *vd, int faulted, int degraded)
{
if (faulted == vd->vdev_children) {
if (vdev_children_are_offline(vd)) {
vdev_set_state(vd, B_FALSE, VDEV_STATE_OFFLINE,
VDEV_AUX_CHILDREN_OFFLINE);
} else {
vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN,
VDEV_AUX_NO_REPLICAS);
}
} else if (degraded + faulted != 0) {
vdev_set_state(vd, B_FALSE, VDEV_STATE_DEGRADED, VDEV_AUX_NONE);
} else {
vdev_set_state(vd, B_FALSE, VDEV_STATE_HEALTHY, VDEV_AUX_NONE);
}
}
vdev_ops_t vdev_mirror_ops = {
.vdev_op_open = vdev_mirror_open,
.vdev_op_close = vdev_mirror_close,
.vdev_op_asize = vdev_default_asize,
.vdev_op_io_start = vdev_mirror_io_start,
.vdev_op_io_done = vdev_mirror_io_done,
.vdev_op_state_change = vdev_mirror_state_change,
.vdev_op_need_resilver = NULL,
.vdev_op_hold = NULL,
.vdev_op_rele = NULL,
.vdev_op_remap = NULL,
.vdev_op_xlate = vdev_default_xlate,
.vdev_op_type = VDEV_TYPE_MIRROR, /* name of this vdev type */
.vdev_op_leaf = B_FALSE /* not a leaf vdev */
};
vdev_ops_t vdev_replacing_ops = {
.vdev_op_open = vdev_mirror_open,
.vdev_op_close = vdev_mirror_close,
.vdev_op_asize = vdev_default_asize,
.vdev_op_io_start = vdev_mirror_io_start,
.vdev_op_io_done = vdev_mirror_io_done,
.vdev_op_state_change = vdev_mirror_state_change,
.vdev_op_need_resilver = NULL,
.vdev_op_hold = NULL,
.vdev_op_rele = NULL,
.vdev_op_remap = NULL,
.vdev_op_xlate = vdev_default_xlate,
.vdev_op_type = VDEV_TYPE_REPLACING, /* name of this vdev type */
.vdev_op_leaf = B_FALSE /* not a leaf vdev */
};
vdev_ops_t vdev_spare_ops = {
.vdev_op_open = vdev_mirror_open,
.vdev_op_close = vdev_mirror_close,
.vdev_op_asize = vdev_default_asize,
.vdev_op_io_start = vdev_mirror_io_start,
.vdev_op_io_done = vdev_mirror_io_done,
.vdev_op_state_change = vdev_mirror_state_change,
.vdev_op_need_resilver = NULL,
.vdev_op_hold = NULL,
.vdev_op_rele = NULL,
.vdev_op_remap = NULL,
.vdev_op_xlate = vdev_default_xlate,
.vdev_op_type = VDEV_TYPE_SPARE, /* name of this vdev type */
.vdev_op_leaf = B_FALSE /* not a leaf vdev */
};
/* BEGIN CSTYLED */
ZFS_MODULE_PARAM(zfs_vdev_mirror, zfs_vdev_mirror_, rotating_inc, INT, ZMOD_RW,
"Rotating media load increment for non-seeking I/O's");
ZFS_MODULE_PARAM(zfs_vdev_mirror, zfs_vdev_mirror_, rotating_seek_inc, INT, ZMOD_RW,
"Rotating media load increment for seeking I/O's");
ZFS_MODULE_PARAM(zfs_vdev_mirror, zfs_vdev_mirror_, rotating_seek_offset, INT, ZMOD_RW,
"Offset in bytes from the last I/O which triggers "
"a reduced rotating media seek increment");
ZFS_MODULE_PARAM(zfs_vdev_mirror, zfs_vdev_mirror_, non_rotating_inc, INT, ZMOD_RW,
"Non-rotating media load increment for non-seeking I/O's");
ZFS_MODULE_PARAM(zfs_vdev_mirror, zfs_vdev_mirror_, non_rotating_seek_inc, INT, ZMOD_RW,
"Non-rotating media load increment for seeking I/O's");
/* END CSTYLED */