+++ /dev/null
-/*
- * 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/vdev_impl.h>
-#include <sys/zio.h>
-#include <sys/abd.h>
-#include <sys/fs/zfs.h>
-
-/*
- * 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_replacing;
- 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 replacing, boolean_t root)
-{
- mirror_map_t *mm;
-
- mm = kmem_zalloc(vdev_mirror_map_size(children), KM_SLEEP);
- mm->mm_children = children;
- mm->mm_replacing = replacing;
- 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)
- 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.
- */
- 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)
- 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)
- return (load + (zfs_vdev_mirror_rotating_seek_inc / 2));
-
- /* Apply the full seek increment to all other I/O's. */
- 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;
-
- mm = vdev_mirror_map_alloc(BP_GET_NDVAS(zio->io_bp), 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]);
- }
- } else {
- mm = vdev_mirror_map_alloc(vd->vdev_children,
- (vd->vdev_ops == &vdev_replacing_ops ||
- vd->vdev_ops == &vdev_spare_ops), 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 *ashift)
-{
- int numerrors = 0;
- int lasterror = 0;
- int c;
-
- if (vd->vdev_children == 0) {
- vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
- return (SET_ERROR(EINVAL));
- }
-
- vdev_open_children(vd);
-
- for (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;
- *ashift = MAX(*ashift, cvd->vdev_ashift);
- }
-
- if (numerrors == vd->vdev_children) {
- vd->vdev_stat.vs_aux = VDEV_AUX_NO_REPLICAS;
- return (lasterror);
- }
-
- return (0);
-}
-
-static void
-vdev_mirror_close(vdev_t *vd)
-{
- int c;
-
- for (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
- * prefering 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)
- return (mm->mm_preferred[0]);
-
-
- if (mm->mm_preferred_cnt > 1)
- 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 (zio->io_type == ZIO_TYPE_READ) {
- if ((zio->io_flags & ZIO_FLAG_SCRUB) && !mm->mm_replacing) {
- /*
- * For scrubbing reads 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 c, error[2] = { 0, 0 };
-
- for (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;
-
- 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_replacing))) {
- /*
- * 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;
- if (!(zio->io_flags & ZIO_FLAG_SCRUB) &&
- !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_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)
- 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_mirror_open,
- vdev_mirror_close,
- vdev_default_asize,
- vdev_mirror_io_start,
- vdev_mirror_io_done,
- vdev_mirror_state_change,
- NULL,
- NULL,
- NULL,
- VDEV_TYPE_MIRROR, /* name of this vdev type */
- B_FALSE /* not a leaf vdev */
-};
-
-vdev_ops_t vdev_replacing_ops = {
- vdev_mirror_open,
- vdev_mirror_close,
- vdev_default_asize,
- vdev_mirror_io_start,
- vdev_mirror_io_done,
- vdev_mirror_state_change,
- NULL,
- NULL,
- NULL,
- VDEV_TYPE_REPLACING, /* name of this vdev type */
- B_FALSE /* not a leaf vdev */
-};
-
-vdev_ops_t vdev_spare_ops = {
- vdev_mirror_open,
- vdev_mirror_close,
- vdev_default_asize,
- vdev_mirror_io_start,
- vdev_mirror_io_done,
- vdev_mirror_state_change,
- NULL,
- NULL,
- NULL,
- VDEV_TYPE_SPARE, /* name of this vdev type */
- B_FALSE /* not a leaf vdev */
-};
-
-#if defined(_KERNEL) && defined(HAVE_SPL)
-/* BEGIN CSTYLED */
-module_param(zfs_vdev_mirror_rotating_inc, int, 0644);
-MODULE_PARM_DESC(zfs_vdev_mirror_rotating_inc,
- "Rotating media load increment for non-seeking I/O's");
-
-module_param(zfs_vdev_mirror_rotating_seek_inc, int, 0644);
-MODULE_PARM_DESC(zfs_vdev_mirror_rotating_seek_inc,
- "Rotating media load increment for seeking I/O's");
-
-module_param(zfs_vdev_mirror_rotating_seek_offset, int, 0644);
-
-MODULE_PARM_DESC(zfs_vdev_mirror_rotating_seek_offset,
- "Offset in bytes from the last I/O which "
- "triggers a reduced rotating media seek increment");
-
-module_param(zfs_vdev_mirror_non_rotating_inc, int, 0644);
-MODULE_PARM_DESC(zfs_vdev_mirror_non_rotating_inc,
- "Non-rotating media load increment for non-seeking I/O's");
-
-module_param(zfs_vdev_mirror_non_rotating_seek_inc, int, 0644);
-MODULE_PARM_DESC(zfs_vdev_mirror_non_rotating_seek_inc,
- "Non-rotating media load increment for seeking I/O's");
-/* END CSTYLED */
-#endif
projects / mirror_ubuntu-bionic-kernel.git / blobdiff