diff options
Diffstat (limited to 'sys/contrib/opensolaris/uts/common/fs/zfs/vdev_label.c')
| -rw-r--r-- | sys/contrib/opensolaris/uts/common/fs/zfs/vdev_label.c | 1011 |
1 files changed, 0 insertions, 1011 deletions
diff --git a/sys/contrib/opensolaris/uts/common/fs/zfs/vdev_label.c b/sys/contrib/opensolaris/uts/common/fs/zfs/vdev_label.c deleted file mode 100644 index 9d9f555..0000000 --- a/sys/contrib/opensolaris/uts/common/fs/zfs/vdev_label.c +++ /dev/null @@ -1,1011 +0,0 @@ -/* - * 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 2007 Sun Microsystems, Inc. All rights reserved. - * Use is subject to license terms. - */ - -#pragma ident "%Z%%M% %I% %E% SMI" - -/* - * Virtual Device Labels - * --------------------- - * - * The vdev label serves several distinct purposes: - * - * 1. Uniquely identify this device as part of a ZFS pool and confirm its - * identity within the pool. - * - * 2. Verify that all the devices given in a configuration are present - * within the pool. - * - * 3. Determine the uberblock for the pool. - * - * 4. In case of an import operation, determine the configuration of the - * toplevel vdev of which it is a part. - * - * 5. If an import operation cannot find all the devices in the pool, - * provide enough information to the administrator to determine which - * devices are missing. - * - * It is important to note that while the kernel is responsible for writing the - * label, it only consumes the information in the first three cases. The - * latter information is only consumed in userland when determining the - * configuration to import a pool. - * - * - * Label Organization - * ------------------ - * - * Before describing the contents of the label, it's important to understand how - * the labels are written and updated with respect to the uberblock. - * - * When the pool configuration is altered, either because it was newly created - * or a device was added, we want to update all the labels such that we can deal - * with fatal failure at any point. To this end, each disk has two labels which - * are updated before and after the uberblock is synced. Assuming we have - * labels and an uberblock with the following transacation groups: - * - * L1 UB L2 - * +------+ +------+ +------+ - * | | | | | | - * | t10 | | t10 | | t10 | - * | | | | | | - * +------+ +------+ +------+ - * - * In this stable state, the labels and the uberblock were all updated within - * the same transaction group (10). Each label is mirrored and checksummed, so - * that we can detect when we fail partway through writing the label. - * - * In order to identify which labels are valid, the labels are written in the - * following manner: - * - * 1. For each vdev, update 'L1' to the new label - * 2. Update the uberblock - * 3. For each vdev, update 'L2' to the new label - * - * Given arbitrary failure, we can determine the correct label to use based on - * the transaction group. If we fail after updating L1 but before updating the - * UB, we will notice that L1's transaction group is greater than the uberblock, - * so L2 must be valid. If we fail after writing the uberblock but before - * writing L2, we will notice that L2's transaction group is less than L1, and - * therefore L1 is valid. - * - * Another added complexity is that not every label is updated when the config - * is synced. If we add a single device, we do not want to have to re-write - * every label for every device in the pool. This means that both L1 and L2 may - * be older than the pool uberblock, because the necessary information is stored - * on another vdev. - * - * - * On-disk Format - * -------------- - * - * The vdev label consists of two distinct parts, and is wrapped within the - * vdev_label_t structure. The label includes 8k of padding to permit legacy - * VTOC disk labels, but is otherwise ignored. - * - * The first half of the label is a packed nvlist which contains pool wide - * properties, per-vdev properties, and configuration information. It is - * described in more detail below. - * - * The latter half of the label consists of a redundant array of uberblocks. - * These uberblocks are updated whenever a transaction group is committed, - * or when the configuration is updated. When a pool is loaded, we scan each - * vdev for the 'best' uberblock. - * - * - * Configuration Information - * ------------------------- - * - * The nvlist describing the pool and vdev contains the following elements: - * - * version ZFS on-disk version - * name Pool name - * state Pool state - * txg Transaction group in which this label was written - * pool_guid Unique identifier for this pool - * vdev_tree An nvlist describing vdev tree. - * - * Each leaf device label also contains the following: - * - * top_guid Unique ID for top-level vdev in which this is contained - * guid Unique ID for the leaf vdev - * - * The 'vs' configuration follows the format described in 'spa_config.c'. - */ - -#include <sys/zfs_context.h> -#include <sys/spa.h> -#include <sys/spa_impl.h> -#include <sys/dmu.h> -#include <sys/zap.h> -#include <sys/vdev.h> -#include <sys/vdev_impl.h> -#include <sys/uberblock_impl.h> -#include <sys/metaslab.h> -#include <sys/zio.h> -#include <sys/fs/zfs.h> - -/* - * Basic routines to read and write from a vdev label. - * Used throughout the rest of this file. - */ -uint64_t -vdev_label_offset(uint64_t psize, int l, uint64_t offset) -{ - ASSERT(offset < sizeof (vdev_label_t)); - - return (offset + l * sizeof (vdev_label_t) + (l < VDEV_LABELS / 2 ? - 0 : psize - VDEV_LABELS * sizeof (vdev_label_t))); -} - -static void -vdev_label_read(zio_t *zio, vdev_t *vd, int l, void *buf, uint64_t offset, - uint64_t size, zio_done_func_t *done, void *private) -{ - ASSERT(vd->vdev_children == 0); - - zio_nowait(zio_read_phys(zio, vd, - vdev_label_offset(vd->vdev_psize, l, offset), - size, buf, ZIO_CHECKSUM_LABEL, done, private, - ZIO_PRIORITY_SYNC_READ, - ZIO_FLAG_CONFIG_HELD | ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE)); -} - -static void -vdev_label_write(zio_t *zio, vdev_t *vd, int l, void *buf, uint64_t offset, - uint64_t size, zio_done_func_t *done, void *private) -{ - ASSERT(vd->vdev_children == 0); - - zio_nowait(zio_write_phys(zio, vd, - vdev_label_offset(vd->vdev_psize, l, offset), - size, buf, ZIO_CHECKSUM_LABEL, done, private, - ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CONFIG_HELD | ZIO_FLAG_CANFAIL)); -} - -/* - * Generate the nvlist representing this vdev's config. - */ -nvlist_t * -vdev_config_generate(spa_t *spa, vdev_t *vd, boolean_t getstats, - boolean_t isspare) -{ - nvlist_t *nv = NULL; - - VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0); - - VERIFY(nvlist_add_string(nv, ZPOOL_CONFIG_TYPE, - vd->vdev_ops->vdev_op_type) == 0); - if (!isspare) - VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_ID, vd->vdev_id) - == 0); - VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_GUID, vd->vdev_guid) == 0); - - if (vd->vdev_path != NULL) - VERIFY(nvlist_add_string(nv, ZPOOL_CONFIG_PATH, - vd->vdev_path) == 0); - - if (vd->vdev_devid != NULL) - VERIFY(nvlist_add_string(nv, ZPOOL_CONFIG_DEVID, - vd->vdev_devid) == 0); - - if (vd->vdev_nparity != 0) { - ASSERT(strcmp(vd->vdev_ops->vdev_op_type, - VDEV_TYPE_RAIDZ) == 0); - - /* - * Make sure someone hasn't managed to sneak a fancy new vdev - * into a crufty old storage pool. - */ - ASSERT(vd->vdev_nparity == 1 || - (vd->vdev_nparity == 2 && - spa_version(spa) >= ZFS_VERSION_RAID6)); - - /* - * Note that we'll add the nparity tag even on storage pools - * that only support a single parity device -- older software - * will just ignore it. - */ - VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_NPARITY, - vd->vdev_nparity) == 0); - } - - if (vd->vdev_wholedisk != -1ULL) - VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_WHOLE_DISK, - vd->vdev_wholedisk) == 0); - - if (vd->vdev_not_present) - VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_NOT_PRESENT, 1) == 0); - - if (vd->vdev_isspare) - VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_IS_SPARE, 1) == 0); - - if (!isspare && vd == vd->vdev_top) { - VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_METASLAB_ARRAY, - vd->vdev_ms_array) == 0); - VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_METASLAB_SHIFT, - vd->vdev_ms_shift) == 0); - VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_ASHIFT, - vd->vdev_ashift) == 0); - VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_ASIZE, - vd->vdev_asize) == 0); - } - - if (vd->vdev_dtl.smo_object != 0) - VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_DTL, - vd->vdev_dtl.smo_object) == 0); - - if (getstats) { - vdev_stat_t vs; - vdev_get_stats(vd, &vs); - VERIFY(nvlist_add_uint64_array(nv, ZPOOL_CONFIG_STATS, - (uint64_t *)&vs, sizeof (vs) / sizeof (uint64_t)) == 0); - } - - if (!vd->vdev_ops->vdev_op_leaf) { - nvlist_t **child; - int c; - - child = kmem_alloc(vd->vdev_children * sizeof (nvlist_t *), - KM_SLEEP); - - for (c = 0; c < vd->vdev_children; c++) - child[c] = vdev_config_generate(spa, vd->vdev_child[c], - getstats, isspare); - - VERIFY(nvlist_add_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN, - child, vd->vdev_children) == 0); - - for (c = 0; c < vd->vdev_children; c++) - nvlist_free(child[c]); - - kmem_free(child, vd->vdev_children * sizeof (nvlist_t *)); - - } else { - if (vd->vdev_offline && !vd->vdev_tmpoffline) - VERIFY(nvlist_add_uint64(nv, ZPOOL_CONFIG_OFFLINE, - B_TRUE) == 0); - else - (void) nvlist_remove(nv, ZPOOL_CONFIG_OFFLINE, - DATA_TYPE_UINT64); - } - - return (nv); -} - -nvlist_t * -vdev_label_read_config(vdev_t *vd) -{ - spa_t *spa = vd->vdev_spa; - nvlist_t *config = NULL; - vdev_phys_t *vp; - zio_t *zio; - int l; - - ASSERT(spa_config_held(spa, RW_READER)); - - if (vdev_is_dead(vd)) - return (NULL); - - vp = zio_buf_alloc(sizeof (vdev_phys_t)); - - for (l = 0; l < VDEV_LABELS; l++) { - - zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL | - ZIO_FLAG_SPECULATIVE | ZIO_FLAG_CONFIG_HELD); - - vdev_label_read(zio, vd, l, vp, - offsetof(vdev_label_t, vl_vdev_phys), - sizeof (vdev_phys_t), NULL, NULL); - - if (zio_wait(zio) == 0 && - nvlist_unpack(vp->vp_nvlist, sizeof (vp->vp_nvlist), - &config, 0) == 0) - break; - - if (config != NULL) { - nvlist_free(config); - config = NULL; - } - } - - zio_buf_free(vp, sizeof (vdev_phys_t)); - - return (config); -} - -/* - * Determine if a device is in use. The 'spare_guid' parameter will be filled - * in with the device guid if this spare is active elsewhere on the system. - */ -static boolean_t -vdev_inuse(vdev_t *vd, uint64_t crtxg, vdev_labeltype_t reason, - uint64_t *spare_guid) -{ - spa_t *spa = vd->vdev_spa; - uint64_t state, pool_guid, device_guid, txg, spare_pool; - uint64_t vdtxg = 0; - nvlist_t *label; - - if (spare_guid) - *spare_guid = 0ULL; - - /* - * Read the label, if any, and perform some basic sanity checks. - */ - if ((label = vdev_label_read_config(vd)) == NULL) - return (B_FALSE); - - (void) nvlist_lookup_uint64(label, ZPOOL_CONFIG_CREATE_TXG, - &vdtxg); - - if (nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_STATE, - &state) != 0 || - nvlist_lookup_uint64(label, ZPOOL_CONFIG_GUID, - &device_guid) != 0) { - nvlist_free(label); - return (B_FALSE); - } - - if (state != POOL_STATE_SPARE && - (nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_GUID, - &pool_guid) != 0 || - nvlist_lookup_uint64(label, ZPOOL_CONFIG_POOL_TXG, - &txg) != 0)) { - nvlist_free(label); - return (B_FALSE); - } - - nvlist_free(label); - - /* - * Check to see if this device indeed belongs to the pool it claims to - * be a part of. The only way this is allowed is if the device is a hot - * spare (which we check for later on). - */ - if (state != POOL_STATE_SPARE && - !spa_guid_exists(pool_guid, device_guid) && - !spa_spare_exists(device_guid, NULL)) - return (B_FALSE); - - /* - * If the transaction group is zero, then this an initialized (but - * unused) label. This is only an error if the create transaction - * on-disk is the same as the one we're using now, in which case the - * user has attempted to add the same vdev multiple times in the same - * transaction. - */ - if (state != POOL_STATE_SPARE && txg == 0 && vdtxg == crtxg) - return (B_TRUE); - - /* - * Check to see if this is a spare device. We do an explicit check for - * spa_has_spare() here because it may be on our pending list of spares - * to add. - */ - if (spa_spare_exists(device_guid, &spare_pool) || - spa_has_spare(spa, device_guid)) { - if (spare_guid) - *spare_guid = device_guid; - - switch (reason) { - case VDEV_LABEL_CREATE: - return (B_TRUE); - - case VDEV_LABEL_REPLACE: - return (!spa_has_spare(spa, device_guid) || - spare_pool != 0ULL); - - case VDEV_LABEL_SPARE: - return (spa_has_spare(spa, device_guid)); - } - } - - /* - * If the device is marked ACTIVE, then this device is in use by another - * pool on the system. - */ - return (state == POOL_STATE_ACTIVE); -} - -/* - * Initialize a vdev label. We check to make sure each leaf device is not in - * use, and writable. We put down an initial label which we will later - * overwrite with a complete label. Note that it's important to do this - * sequentially, not in parallel, so that we catch cases of multiple use of the - * same leaf vdev in the vdev we're creating -- e.g. mirroring a disk with - * itself. - */ -int -vdev_label_init(vdev_t *vd, uint64_t crtxg, vdev_labeltype_t reason) -{ - spa_t *spa = vd->vdev_spa; - nvlist_t *label; - vdev_phys_t *vp; - vdev_boot_header_t *vb; - uberblock_t *ub; - zio_t *zio; - int l, c, n; - char *buf; - size_t buflen; - int error; - uint64_t spare_guid; - - ASSERT(spa_config_held(spa, RW_WRITER)); - - for (c = 0; c < vd->vdev_children; c++) - if ((error = vdev_label_init(vd->vdev_child[c], - crtxg, reason)) != 0) - return (error); - - if (!vd->vdev_ops->vdev_op_leaf) - return (0); - - /* - * Dead vdevs cannot be initialized. - */ - if (vdev_is_dead(vd)) - return (EIO); - - /* - * Determine if the vdev is in use. - */ - if (reason != VDEV_LABEL_REMOVE && - vdev_inuse(vd, crtxg, reason, &spare_guid)) - return (EBUSY); - - ASSERT(reason != VDEV_LABEL_REMOVE || - vdev_inuse(vd, crtxg, reason, NULL)); - - /* - * If this is a request to add or replace a spare that is in use - * elsewhere on the system, then we must update the guid (which was - * initialized to a random value) to reflect the actual GUID (which is - * shared between multiple pools). - */ - if (reason != VDEV_LABEL_REMOVE && spare_guid != 0ULL) { - vdev_t *pvd = vd->vdev_parent; - - for (; pvd != NULL; pvd = pvd->vdev_parent) { - pvd->vdev_guid_sum -= vd->vdev_guid; - pvd->vdev_guid_sum += spare_guid; - } - - vd->vdev_guid = vd->vdev_guid_sum = spare_guid; - - /* - * If this is a replacement, then we want to fallthrough to the - * rest of the code. If we're adding a spare, then it's already - * labelled appropriately and we can just return. - */ - if (reason == VDEV_LABEL_SPARE) - return (0); - ASSERT(reason == VDEV_LABEL_REPLACE); - } - - /* - * Initialize its label. - */ - vp = zio_buf_alloc(sizeof (vdev_phys_t)); - bzero(vp, sizeof (vdev_phys_t)); - - /* - * Generate a label describing the pool and our top-level vdev. - * We mark it as being from txg 0 to indicate that it's not - * really part of an active pool just yet. The labels will - * be written again with a meaningful txg by spa_sync(). - */ - if (reason == VDEV_LABEL_SPARE || - (reason == VDEV_LABEL_REMOVE && vd->vdev_isspare)) { - /* - * For inactive hot spares, we generate a special label that - * identifies as a mutually shared hot spare. We write the - * label if we are adding a hot spare, or if we are removing an - * active hot spare (in which case we want to revert the - * labels). - */ - VERIFY(nvlist_alloc(&label, NV_UNIQUE_NAME, KM_SLEEP) == 0); - - VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_VERSION, - spa_version(spa)) == 0); - VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_POOL_STATE, - POOL_STATE_SPARE) == 0); - VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_GUID, - vd->vdev_guid) == 0); - } else { - label = spa_config_generate(spa, vd, 0ULL, B_FALSE); - - /* - * Add our creation time. This allows us to detect multiple - * vdev uses as described above, and automatically expires if we - * fail. - */ - VERIFY(nvlist_add_uint64(label, ZPOOL_CONFIG_CREATE_TXG, - crtxg) == 0); - } - - buf = vp->vp_nvlist; - buflen = sizeof (vp->vp_nvlist); - - error = nvlist_pack(label, &buf, &buflen, NV_ENCODE_XDR, KM_SLEEP); - if (error != 0) { - nvlist_free(label); - zio_buf_free(vp, sizeof (vdev_phys_t)); - /* EFAULT means nvlist_pack ran out of room */ - return (error == EFAULT ? ENAMETOOLONG : EINVAL); - } - - /* - * Initialize boot block header. - */ - vb = zio_buf_alloc(sizeof (vdev_boot_header_t)); - bzero(vb, sizeof (vdev_boot_header_t)); - vb->vb_magic = VDEV_BOOT_MAGIC; - vb->vb_version = VDEV_BOOT_VERSION; - vb->vb_offset = VDEV_BOOT_OFFSET; - vb->vb_size = VDEV_BOOT_SIZE; - - /* - * Initialize uberblock template. - */ - ub = zio_buf_alloc(VDEV_UBERBLOCK_SIZE(vd)); - bzero(ub, VDEV_UBERBLOCK_SIZE(vd)); - *ub = spa->spa_uberblock; - ub->ub_txg = 0; - - /* - * Write everything in parallel. - */ - zio = zio_root(spa, NULL, NULL, - ZIO_FLAG_CONFIG_HELD | ZIO_FLAG_CANFAIL); - - for (l = 0; l < VDEV_LABELS; l++) { - - vdev_label_write(zio, vd, l, vp, - offsetof(vdev_label_t, vl_vdev_phys), - sizeof (vdev_phys_t), NULL, NULL); - - vdev_label_write(zio, vd, l, vb, - offsetof(vdev_label_t, vl_boot_header), - sizeof (vdev_boot_header_t), NULL, NULL); - - for (n = 0; n < VDEV_UBERBLOCK_COUNT(vd); n++) { - vdev_label_write(zio, vd, l, ub, - VDEV_UBERBLOCK_OFFSET(vd, n), - VDEV_UBERBLOCK_SIZE(vd), NULL, NULL); - } - } - - error = zio_wait(zio); - - nvlist_free(label); - zio_buf_free(ub, VDEV_UBERBLOCK_SIZE(vd)); - zio_buf_free(vb, sizeof (vdev_boot_header_t)); - zio_buf_free(vp, sizeof (vdev_phys_t)); - - /* - * If this vdev hasn't been previously identified as a spare, then we - * mark it as such only if a) we are labelling it as a spare, or b) it - * exists as a spare elsewhere in the system. - */ - if (error == 0 && !vd->vdev_isspare && - (reason == VDEV_LABEL_SPARE || - spa_spare_exists(vd->vdev_guid, NULL))) - spa_spare_add(vd); - - return (error); -} - -/* - * ========================================================================== - * uberblock load/sync - * ========================================================================== - */ - -/* - * Consider the following situation: txg is safely synced to disk. We've - * written the first uberblock for txg + 1, and then we lose power. When we - * come back up, we fail to see the uberblock for txg + 1 because, say, - * it was on a mirrored device and the replica to which we wrote txg + 1 - * is now offline. If we then make some changes and sync txg + 1, and then - * the missing replica comes back, then for a new seconds we'll have two - * conflicting uberblocks on disk with the same txg. The solution is simple: - * among uberblocks with equal txg, choose the one with the latest timestamp. - */ -static int -vdev_uberblock_compare(uberblock_t *ub1, uberblock_t *ub2) -{ - if (ub1->ub_txg < ub2->ub_txg) - return (-1); - if (ub1->ub_txg > ub2->ub_txg) - return (1); - - if (ub1->ub_timestamp < ub2->ub_timestamp) - return (-1); - if (ub1->ub_timestamp > ub2->ub_timestamp) - return (1); - - return (0); -} - -static void -vdev_uberblock_load_done(zio_t *zio) -{ - uberblock_t *ub = zio->io_data; - uberblock_t *ubbest = zio->io_private; - spa_t *spa = zio->io_spa; - - ASSERT3U(zio->io_size, ==, VDEV_UBERBLOCK_SIZE(zio->io_vd)); - - if (zio->io_error == 0 && uberblock_verify(ub) == 0) { - mutex_enter(&spa->spa_uberblock_lock); - if (vdev_uberblock_compare(ub, ubbest) > 0) - *ubbest = *ub; - mutex_exit(&spa->spa_uberblock_lock); - } - - zio_buf_free(zio->io_data, zio->io_size); -} - -void -vdev_uberblock_load(zio_t *zio, vdev_t *vd, uberblock_t *ubbest) -{ - int l, c, n; - - for (c = 0; c < vd->vdev_children; c++) - vdev_uberblock_load(zio, vd->vdev_child[c], ubbest); - - if (!vd->vdev_ops->vdev_op_leaf) - return; - - if (vdev_is_dead(vd)) - return; - - for (l = 0; l < VDEV_LABELS; l++) { - for (n = 0; n < VDEV_UBERBLOCK_COUNT(vd); n++) { - vdev_label_read(zio, vd, l, - zio_buf_alloc(VDEV_UBERBLOCK_SIZE(vd)), - VDEV_UBERBLOCK_OFFSET(vd, n), - VDEV_UBERBLOCK_SIZE(vd), - vdev_uberblock_load_done, ubbest); - } - } -} - -/* - * Write the uberblock to both labels of all leaves of the specified vdev. - * We only get credit for writes to known-visible vdevs; see spa_vdev_add(). - */ -static void -vdev_uberblock_sync_done(zio_t *zio) -{ - uint64_t *good_writes = zio->io_root->io_private; - - if (zio->io_error == 0 && zio->io_vd->vdev_top->vdev_ms_array != 0) - atomic_add_64(good_writes, 1); -} - -static void -vdev_uberblock_sync(zio_t *zio, uberblock_t *ub, vdev_t *vd, uint64_t txg) -{ - int l, c, n; - - for (c = 0; c < vd->vdev_children; c++) - vdev_uberblock_sync(zio, ub, vd->vdev_child[c], txg); - - if (!vd->vdev_ops->vdev_op_leaf) - return; - - if (vdev_is_dead(vd)) - return; - - n = txg & (VDEV_UBERBLOCK_COUNT(vd) - 1); - - ASSERT(ub->ub_txg == txg); - - for (l = 0; l < VDEV_LABELS; l++) - vdev_label_write(zio, vd, l, ub, - VDEV_UBERBLOCK_OFFSET(vd, n), - VDEV_UBERBLOCK_SIZE(vd), - vdev_uberblock_sync_done, NULL); - - dprintf("vdev %s in txg %llu\n", vdev_description(vd), txg); -} - -static int -vdev_uberblock_sync_tree(spa_t *spa, uberblock_t *ub, vdev_t *vd, uint64_t txg) -{ - uberblock_t *ubbuf; - size_t size = vd->vdev_top ? VDEV_UBERBLOCK_SIZE(vd) : SPA_MAXBLOCKSIZE; - uint64_t *good_writes; - zio_t *zio; - int error; - - ubbuf = zio_buf_alloc(size); - bzero(ubbuf, size); - *ubbuf = *ub; - - good_writes = kmem_zalloc(sizeof (uint64_t), KM_SLEEP); - - zio = zio_root(spa, NULL, good_writes, - ZIO_FLAG_CONFIG_HELD | ZIO_FLAG_CANFAIL); - - vdev_uberblock_sync(zio, ubbuf, vd, txg); - - error = zio_wait(zio); - - if (error && *good_writes != 0) { - dprintf("partial success: good_writes = %llu\n", *good_writes); - error = 0; - } - - /* - * It's possible to have no good writes and no error if every vdev is in - * the CANT_OPEN state. - */ - if (*good_writes == 0 && error == 0) - error = EIO; - - kmem_free(good_writes, sizeof (uint64_t)); - zio_buf_free(ubbuf, size); - - return (error); -} - -/* - * Sync out an individual vdev. - */ -static void -vdev_sync_label_done(zio_t *zio) -{ - uint64_t *good_writes = zio->io_root->io_private; - - if (zio->io_error == 0) - atomic_add_64(good_writes, 1); -} - -static void -vdev_sync_label(zio_t *zio, vdev_t *vd, int l, uint64_t txg) -{ - nvlist_t *label; - vdev_phys_t *vp; - char *buf; - size_t buflen; - int c; - - for (c = 0; c < vd->vdev_children; c++) - vdev_sync_label(zio, vd->vdev_child[c], l, txg); - - if (!vd->vdev_ops->vdev_op_leaf) - return; - - if (vdev_is_dead(vd)) - return; - - /* - * Generate a label describing the top-level config to which we belong. - */ - label = spa_config_generate(vd->vdev_spa, vd, txg, B_FALSE); - - vp = zio_buf_alloc(sizeof (vdev_phys_t)); - bzero(vp, sizeof (vdev_phys_t)); - - buf = vp->vp_nvlist; - buflen = sizeof (vp->vp_nvlist); - - if (nvlist_pack(label, &buf, &buflen, NV_ENCODE_XDR, KM_SLEEP) == 0) - vdev_label_write(zio, vd, l, vp, - offsetof(vdev_label_t, vl_vdev_phys), sizeof (vdev_phys_t), - vdev_sync_label_done, NULL); - - zio_buf_free(vp, sizeof (vdev_phys_t)); - nvlist_free(label); - - dprintf("%s label %d txg %llu\n", vdev_description(vd), l, txg); -} - -static int -vdev_sync_labels(vdev_t *vd, int l, uint64_t txg) -{ - uint64_t *good_writes; - zio_t *zio; - int error; - - ASSERT(vd == vd->vdev_top); - - good_writes = kmem_zalloc(sizeof (uint64_t), KM_SLEEP); - - zio = zio_root(vd->vdev_spa, NULL, good_writes, - ZIO_FLAG_CONFIG_HELD | ZIO_FLAG_CANFAIL); - - /* - * Recursively kick off writes to all labels. - */ - vdev_sync_label(zio, vd, l, txg); - - error = zio_wait(zio); - - if (error && *good_writes != 0) { - dprintf("partial success: good_writes = %llu\n", *good_writes); - error = 0; - } - - if (*good_writes == 0 && error == 0) - error = ENODEV; - - kmem_free(good_writes, sizeof (uint64_t)); - - return (error); -} - -/* - * Sync the entire vdev configuration. - * - * The order of operations is carefully crafted to ensure that - * if the system panics or loses power at any time, the state on disk - * is still transactionally consistent. The in-line comments below - * describe the failure semantics at each stage. - * - * Moreover, it is designed to be idempotent: if spa_sync_labels() fails - * at any time, you can just call it again, and it will resume its work. - */ -int -vdev_config_sync(vdev_t *uvd, uint64_t txg) -{ - spa_t *spa = uvd->vdev_spa; - uberblock_t *ub = &spa->spa_uberblock; - vdev_t *rvd = spa->spa_root_vdev; - vdev_t *vd; - zio_t *zio; - int l, error; - - ASSERT(ub->ub_txg <= txg); - - /* - * If this isn't a resync due to I/O errors, and nothing changed - * in this transaction group, and the vdev configuration hasn't changed, - * then there's nothing to do. - */ - if (ub->ub_txg < txg && uberblock_update(ub, rvd, txg) == B_FALSE && - list_is_empty(&spa->spa_dirty_list)) { - dprintf("nothing to sync in %s in txg %llu\n", - spa_name(spa), txg); - return (0); - } - - if (txg > spa_freeze_txg(spa)) - return (0); - - ASSERT(txg <= spa->spa_final_txg); - - dprintf("syncing %s txg %llu\n", spa_name(spa), txg); - - /* - * Flush the write cache of every disk that's been written to - * in this transaction group. This ensures that all blocks - * written in this txg will be committed to stable storage - * before any uberblock that references them. - */ - zio = zio_root(spa, NULL, NULL, - ZIO_FLAG_CONFIG_HELD | ZIO_FLAG_CANFAIL); - for (vd = txg_list_head(&spa->spa_vdev_txg_list, TXG_CLEAN(txg)); vd; - vd = txg_list_next(&spa->spa_vdev_txg_list, vd, TXG_CLEAN(txg))) { - zio_nowait(zio_ioctl(zio, spa, vd, DKIOCFLUSHWRITECACHE, - NULL, NULL, ZIO_PRIORITY_NOW, - ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY)); - } - (void) zio_wait(zio); - - /* - * Sync out the even labels (L0, L2) for every dirty vdev. If the - * system dies in the middle of this process, that's OK: all of the - * even labels that made it to disk will be newer than any uberblock, - * and will therefore be considered invalid. The odd labels (L1, L3), - * which have not yet been touched, will still be valid. - */ - for (vd = list_head(&spa->spa_dirty_list); vd != NULL; - vd = list_next(&spa->spa_dirty_list, vd)) { - for (l = 0; l < VDEV_LABELS; l++) { - if (l & 1) - continue; - if ((error = vdev_sync_labels(vd, l, txg)) != 0) - return (error); - } - } - - /* - * Flush the new labels to disk. This ensures that all even-label - * updates are committed to stable storage before the uberblock update. - */ - zio = zio_root(spa, NULL, NULL, - ZIO_FLAG_CONFIG_HELD | ZIO_FLAG_CANFAIL); - for (vd = list_head(&spa->spa_dirty_list); vd != NULL; - vd = list_next(&spa->spa_dirty_list, vd)) { - zio_nowait(zio_ioctl(zio, spa, vd, DKIOCFLUSHWRITECACHE, - NULL, NULL, ZIO_PRIORITY_NOW, - ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY)); - } - (void) zio_wait(zio); - - /* - * Sync the uberblocks to all vdevs in the tree specified by uvd. - * If the system dies in the middle of this step, there are two cases - * to consider, and the on-disk state is consistent either way: - * - * (1) If none of the new uberblocks made it to disk, then the - * previous uberblock will be the newest, and the odd labels - * (which had not yet been touched) will be valid with respect - * to that uberblock. - * - * (2) If one or more new uberblocks made it to disk, then they - * will be the newest, and the even labels (which had all - * been successfully committed) will be valid with respect - * to the new uberblocks. - */ - if ((error = vdev_uberblock_sync_tree(spa, ub, uvd, txg)) != 0) - return (error); - - /* - * Flush the uberblocks to disk. This ensures that the odd labels - * are no longer needed (because the new uberblocks and the even - * labels are safely on disk), so it is safe to overwrite them. - */ - (void) zio_wait(zio_ioctl(NULL, spa, uvd, DKIOCFLUSHWRITECACHE, - NULL, NULL, ZIO_PRIORITY_NOW, - ZIO_FLAG_CONFIG_HELD | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY)); - - /* - * Sync out odd labels for every dirty vdev. If the system dies - * in the middle of this process, the even labels and the new - * uberblocks will suffice to open the pool. The next time - * the pool is opened, the first thing we'll do -- before any - * user data is modified -- is mark every vdev dirty so that - * all labels will be brought up to date. - */ - for (vd = list_head(&spa->spa_dirty_list); vd != NULL; - vd = list_next(&spa->spa_dirty_list, vd)) { - for (l = 0; l < VDEV_LABELS; l++) { - if ((l & 1) == 0) - continue; - if ((error = vdev_sync_labels(vd, l, txg)) != 0) - return (error); - } - } - - /* - * Flush the new labels to disk. This ensures that all odd-label - * updates are committed to stable storage before the next - * transaction group begins. - */ - zio = zio_root(spa, NULL, NULL, - ZIO_FLAG_CONFIG_HELD | ZIO_FLAG_CANFAIL); - for (vd = list_head(&spa->spa_dirty_list); vd != NULL; - vd = list_next(&spa->spa_dirty_list, vd)) { - zio_nowait(zio_ioctl(zio, spa, vd, DKIOCFLUSHWRITECACHE, - NULL, NULL, ZIO_PRIORITY_NOW, - ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY)); - } - (void) zio_wait(zio); - - return (0); -} |
