/* * 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, 2014 by Delphix. All rights reserved. */ #include #include #include #include #include /* * Virtual device vector for mirroring. */ typedef struct mirror_child { vdev_t *mc_vd; uint64_t mc_offset; int mc_error; uint8_t mc_tried; uint8_t mc_skipped; uint8_t mc_speculative; } mirror_child_t; typedef struct mirror_map { int mm_children; int mm_replacing; int mm_preferred; int mm_root; mirror_child_t mm_child[1]; } mirror_map_t; int vdev_mirror_shift = 21; static void vdev_mirror_map_free(zio_t *zio) { mirror_map_t *mm = zio->io_vsd; kmem_free(mm, offsetof(mirror_map_t, mm_child[mm->mm_children])); } static const zio_vsd_ops_t vdev_mirror_vsd_ops = { vdev_mirror_map_free, zio_vsd_default_cksum_report }; static mirror_map_t * vdev_mirror_map_alloc(zio_t *zio) { mirror_map_t *mm = NULL; mirror_child_t *mc; vdev_t *vd = zio->io_vd; int c, d; if (vd == NULL) { dva_t *dva = zio->io_bp->blk_dva; spa_t *spa = zio->io_spa; c = BP_GET_NDVAS(zio->io_bp); mm = kmem_zalloc(offsetof(mirror_map_t, mm_child[c]), KM_SLEEP); mm->mm_children = c; mm->mm_replacing = B_FALSE; mm->mm_preferred = spa_get_random(c); mm->mm_root = B_TRUE; /* * 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. */ for (c = mm->mm_preferred, d = c - 1; d >= 0; d--) { if (DVA_GET_VDEV(&dva[d]) == DVA_GET_VDEV(&dva[c])) mm->mm_preferred = d; } 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 { c = vd->vdev_children; mm = kmem_zalloc(offsetof(mirror_map_t, mm_child[c]), KM_SLEEP); mm->mm_children = c; mm->mm_replacing = (vd->vdev_ops == &vdev_replacing_ops || vd->vdev_ops == &vdev_spare_ops); mm->mm_preferred = mm->mm_replacing ? 0 : (zio->io_offset >> vdev_mirror_shift) % c; mm->mm_root = 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; 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; *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) { 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; mutex_enter(&zio->io_lock); while ((pio = zio_walk_parents(zio)) != NULL) { mutex_enter(&pio->io_lock); ASSERT3U(zio->io_size, >=, pio->io_size); bcopy(zio->io_data, pio->io_data, pio->io_size); mutex_exit(&pio->io_lock); } mutex_exit(&zio->io_lock); } zio_buf_free(zio->io_data, zio->io_size); mc->mc_error = zio->io_error; mc->mc_tried = 1; mc->mc_skipped = 0; } /* * 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; mirror_child_t *mc; uint64_t txg = zio->io_txg; int i, c; ASSERT(zio->io_bp == NULL || BP_PHYSICAL_BIRTH(zio->io_bp) == txg); /* * Try to find a child whose DTL doesn't contain the block to read. * If a child is known to be completely inaccessible (indicated by * vdev_readable() returning B_FALSE), don't even try. */ for (i = 0, c = mm->mm_preferred; i < mm->mm_children; i++, c++) { if (c >= mm->mm_children) c = 0; mc = &mm->mm_child[c]; if (mc->mc_tried || mc->mc_skipped) continue; if (!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)) return (c); mc->mc_error = SET_ERROR(ESTALE); mc->mc_skipped = 1; mc->mc_speculative = 1; } /* * 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_alloc(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, zio_buf_alloc(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_data, 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; 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_data, 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_data, 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, 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, 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, VDEV_TYPE_SPARE, /* name of this vdev type */ B_FALSE /* not a leaf vdev */ };