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Diffstat (limited to 'sys/cddl/contrib/opensolaris/uts/common/fs/zfs/metaslab.c')
| -rw-r--r-- | sys/cddl/contrib/opensolaris/uts/common/fs/zfs/metaslab.c | 4216 |
1 files changed, 4216 insertions, 0 deletions
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/metaslab.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/metaslab.c new file mode 100644 index 000000000000..fcb1f3487b31 --- /dev/null +++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/metaslab.c @@ -0,0 +1,4216 @@ +/* + * 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) 2005, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2011, 2018 by Delphix. All rights reserved. + * Copyright (c) 2013 by Saso Kiselkov. All rights reserved. + * Copyright (c) 2014 Integros [integros.com] + */ + +#include <sys/zfs_context.h> +#include <sys/dmu.h> +#include <sys/dmu_tx.h> +#include <sys/space_map.h> +#include <sys/metaslab_impl.h> +#include <sys/vdev_impl.h> +#include <sys/zio.h> +#include <sys/spa_impl.h> +#include <sys/zfeature.h> +#include <sys/vdev_indirect_mapping.h> +#include <sys/zap.h> + +SYSCTL_DECL(_vfs_zfs); +SYSCTL_NODE(_vfs_zfs, OID_AUTO, metaslab, CTLFLAG_RW, 0, "ZFS metaslab"); + +#define GANG_ALLOCATION(flags) \ + ((flags) & (METASLAB_GANG_CHILD | METASLAB_GANG_HEADER)) + +uint64_t metaslab_aliquot = 512ULL << 10; +uint64_t metaslab_force_ganging = SPA_MAXBLOCKSIZE + 1; /* force gang blocks */ +SYSCTL_QUAD(_vfs_zfs_metaslab, OID_AUTO, force_ganging, CTLFLAG_RWTUN, + &metaslab_force_ganging, 0, + "Force gang block allocation for blocks larger than or equal to this value"); + +/* + * Since we can touch multiple metaslabs (and their respective space maps) + * with each transaction group, we benefit from having a smaller space map + * block size since it allows us to issue more I/O operations scattered + * around the disk. + */ +int zfs_metaslab_sm_blksz = (1 << 12); +SYSCTL_INT(_vfs_zfs, OID_AUTO, metaslab_sm_blksz, CTLFLAG_RDTUN, + &zfs_metaslab_sm_blksz, 0, + "Block size for metaslab DTL space map. Power of 2 and greater than 4096."); + +/* + * The in-core space map representation is more compact than its on-disk form. + * The zfs_condense_pct determines how much more compact the in-core + * space map representation must be before we compact it on-disk. + * Values should be greater than or equal to 100. + */ +int zfs_condense_pct = 200; +SYSCTL_INT(_vfs_zfs, OID_AUTO, condense_pct, CTLFLAG_RWTUN, + &zfs_condense_pct, 0, + "Condense on-disk spacemap when it is more than this many percents" + " of in-memory counterpart"); + +/* + * Condensing a metaslab is not guaranteed to actually reduce the amount of + * space used on disk. In particular, a space map uses data in increments of + * MAX(1 << ashift, space_map_blksize), so a metaslab might use the + * same number of blocks after condensing. Since the goal of condensing is to + * reduce the number of IOPs required to read the space map, we only want to + * condense when we can be sure we will reduce the number of blocks used by the + * space map. Unfortunately, we cannot precisely compute whether or not this is + * the case in metaslab_should_condense since we are holding ms_lock. Instead, + * we apply the following heuristic: do not condense a spacemap unless the + * uncondensed size consumes greater than zfs_metaslab_condense_block_threshold + * blocks. + */ +int zfs_metaslab_condense_block_threshold = 4; + +/* + * The zfs_mg_noalloc_threshold defines which metaslab groups should + * be eligible for allocation. The value is defined as a percentage of + * free space. Metaslab groups that have more free space than + * zfs_mg_noalloc_threshold are always eligible for allocations. Once + * a metaslab group's free space is less than or equal to the + * zfs_mg_noalloc_threshold the allocator will avoid allocating to that + * group unless all groups in the pool have reached zfs_mg_noalloc_threshold. + * Once all groups in the pool reach zfs_mg_noalloc_threshold then all + * groups are allowed to accept allocations. Gang blocks are always + * eligible to allocate on any metaslab group. The default value of 0 means + * no metaslab group will be excluded based on this criterion. + */ +int zfs_mg_noalloc_threshold = 0; +SYSCTL_INT(_vfs_zfs, OID_AUTO, mg_noalloc_threshold, CTLFLAG_RWTUN, + &zfs_mg_noalloc_threshold, 0, + "Percentage of metaslab group size that should be free" + " to make it eligible for allocation"); + +/* + * Metaslab groups are considered eligible for allocations if their + * fragmenation metric (measured as a percentage) is less than or equal to + * zfs_mg_fragmentation_threshold. If a metaslab group exceeds this threshold + * then it will be skipped unless all metaslab groups within the metaslab + * class have also crossed this threshold. + */ +int zfs_mg_fragmentation_threshold = 85; +SYSCTL_INT(_vfs_zfs, OID_AUTO, mg_fragmentation_threshold, CTLFLAG_RWTUN, + &zfs_mg_fragmentation_threshold, 0, + "Percentage of metaslab group size that should be considered " + "eligible for allocations unless all metaslab groups within the metaslab class " + "have also crossed this threshold"); + +/* + * Allow metaslabs to keep their active state as long as their fragmentation + * percentage is less than or equal to zfs_metaslab_fragmentation_threshold. An + * active metaslab that exceeds this threshold will no longer keep its active + * status allowing better metaslabs to be selected. + */ +int zfs_metaslab_fragmentation_threshold = 70; +SYSCTL_INT(_vfs_zfs_metaslab, OID_AUTO, fragmentation_threshold, CTLFLAG_RWTUN, + &zfs_metaslab_fragmentation_threshold, 0, + "Maximum percentage of metaslab fragmentation level to keep their active state"); + +/* + * When set will load all metaslabs when pool is first opened. + */ +int metaslab_debug_load = 0; +SYSCTL_INT(_vfs_zfs_metaslab, OID_AUTO, debug_load, CTLFLAG_RWTUN, + &metaslab_debug_load, 0, + "Load all metaslabs when pool is first opened"); + +/* + * When set will prevent metaslabs from being unloaded. + */ +int metaslab_debug_unload = 0; +SYSCTL_INT(_vfs_zfs_metaslab, OID_AUTO, debug_unload, CTLFLAG_RWTUN, + &metaslab_debug_unload, 0, + "Prevent metaslabs from being unloaded"); + +/* + * Minimum size which forces the dynamic allocator to change + * it's allocation strategy. Once the space map cannot satisfy + * an allocation of this size then it switches to using more + * aggressive strategy (i.e search by size rather than offset). + */ +uint64_t metaslab_df_alloc_threshold = SPA_OLD_MAXBLOCKSIZE; +SYSCTL_QUAD(_vfs_zfs_metaslab, OID_AUTO, df_alloc_threshold, CTLFLAG_RWTUN, + &metaslab_df_alloc_threshold, 0, + "Minimum size which forces the dynamic allocator to change it's allocation strategy"); + +/* + * The minimum free space, in percent, which must be available + * in a space map to continue allocations in a first-fit fashion. + * Once the space map's free space drops below this level we dynamically + * switch to using best-fit allocations. + */ +int metaslab_df_free_pct = 4; +SYSCTL_INT(_vfs_zfs_metaslab, OID_AUTO, df_free_pct, CTLFLAG_RWTUN, + &metaslab_df_free_pct, 0, + "The minimum free space, in percent, which must be available in a " + "space map to continue allocations in a first-fit fashion"); + +/* + * A metaslab is considered "free" if it contains a contiguous + * segment which is greater than metaslab_min_alloc_size. + */ +uint64_t metaslab_min_alloc_size = DMU_MAX_ACCESS; +SYSCTL_QUAD(_vfs_zfs_metaslab, OID_AUTO, min_alloc_size, CTLFLAG_RWTUN, + &metaslab_min_alloc_size, 0, + "A metaslab is considered \"free\" if it contains a contiguous " + "segment which is greater than vfs.zfs.metaslab.min_alloc_size"); + +/* + * Percentage of all cpus that can be used by the metaslab taskq. + */ +int metaslab_load_pct = 50; +SYSCTL_INT(_vfs_zfs_metaslab, OID_AUTO, load_pct, CTLFLAG_RWTUN, + &metaslab_load_pct, 0, + "Percentage of cpus that can be used by the metaslab taskq"); + +/* + * Determines how many txgs a metaslab may remain loaded without having any + * allocations from it. As long as a metaslab continues to be used we will + * keep it loaded. + */ +int metaslab_unload_delay = TXG_SIZE * 2; +SYSCTL_INT(_vfs_zfs_metaslab, OID_AUTO, unload_delay, CTLFLAG_RWTUN, + &metaslab_unload_delay, 0, + "Number of TXGs that an unused metaslab can be kept in memory"); + +/* + * Max number of metaslabs per group to preload. + */ +int metaslab_preload_limit = SPA_DVAS_PER_BP; +SYSCTL_INT(_vfs_zfs_metaslab, OID_AUTO, preload_limit, CTLFLAG_RWTUN, + &metaslab_preload_limit, 0, + "Max number of metaslabs per group to preload"); + +/* + * Enable/disable preloading of metaslab. + */ +boolean_t metaslab_preload_enabled = B_TRUE; +SYSCTL_INT(_vfs_zfs_metaslab, OID_AUTO, preload_enabled, CTLFLAG_RWTUN, + &metaslab_preload_enabled, 0, + "Max number of metaslabs per group to preload"); + +/* + * Enable/disable fragmentation weighting on metaslabs. + */ +boolean_t metaslab_fragmentation_factor_enabled = B_TRUE; +SYSCTL_INT(_vfs_zfs_metaslab, OID_AUTO, fragmentation_factor_enabled, CTLFLAG_RWTUN, + &metaslab_fragmentation_factor_enabled, 0, + "Enable fragmentation weighting on metaslabs"); + +/* + * Enable/disable lba weighting (i.e. outer tracks are given preference). + */ +boolean_t metaslab_lba_weighting_enabled = B_TRUE; +SYSCTL_INT(_vfs_zfs_metaslab, OID_AUTO, lba_weighting_enabled, CTLFLAG_RWTUN, + &metaslab_lba_weighting_enabled, 0, + "Enable LBA weighting (i.e. outer tracks are given preference)"); + +/* + * Enable/disable metaslab group biasing. + */ +boolean_t metaslab_bias_enabled = B_TRUE; +SYSCTL_INT(_vfs_zfs_metaslab, OID_AUTO, bias_enabled, CTLFLAG_RWTUN, + &metaslab_bias_enabled, 0, + "Enable metaslab group biasing"); + +/* + * Enable/disable remapping of indirect DVAs to their concrete vdevs. + */ +boolean_t zfs_remap_blkptr_enable = B_TRUE; + +/* + * Enable/disable segment-based metaslab selection. + */ +boolean_t zfs_metaslab_segment_weight_enabled = B_TRUE; + +/* + * When using segment-based metaslab selection, we will continue + * allocating from the active metaslab until we have exhausted + * zfs_metaslab_switch_threshold of its buckets. + */ +int zfs_metaslab_switch_threshold = 2; + +/* + * Internal switch to enable/disable the metaslab allocation tracing + * facility. + */ +boolean_t metaslab_trace_enabled = B_TRUE; + +/* + * Maximum entries that the metaslab allocation tracing facility will keep + * in a given list when running in non-debug mode. We limit the number + * of entries in non-debug mode to prevent us from using up too much memory. + * The limit should be sufficiently large that we don't expect any allocation + * to every exceed this value. In debug mode, the system will panic if this + * limit is ever reached allowing for further investigation. + */ +uint64_t metaslab_trace_max_entries = 5000; + +static uint64_t metaslab_weight(metaslab_t *); +static void metaslab_set_fragmentation(metaslab_t *); +static void metaslab_free_impl(vdev_t *, uint64_t, uint64_t, boolean_t); +static void metaslab_check_free_impl(vdev_t *, uint64_t, uint64_t); +static void metaslab_passivate(metaslab_t *msp, uint64_t weight); +static uint64_t metaslab_weight_from_range_tree(metaslab_t *msp); + +kmem_cache_t *metaslab_alloc_trace_cache; + +/* + * ========================================================================== + * Metaslab classes + * ========================================================================== + */ +metaslab_class_t * +metaslab_class_create(spa_t *spa, metaslab_ops_t *ops) +{ + metaslab_class_t *mc; + + mc = kmem_zalloc(sizeof (metaslab_class_t), KM_SLEEP); + + mc->mc_spa = spa; + mc->mc_rotor = NULL; + mc->mc_ops = ops; + mutex_init(&mc->mc_lock, NULL, MUTEX_DEFAULT, NULL); + mc->mc_alloc_slots = kmem_zalloc(spa->spa_alloc_count * + sizeof (refcount_t), KM_SLEEP); + mc->mc_alloc_max_slots = kmem_zalloc(spa->spa_alloc_count * + sizeof (uint64_t), KM_SLEEP); + for (int i = 0; i < spa->spa_alloc_count; i++) + refcount_create_tracked(&mc->mc_alloc_slots[i]); + + return (mc); +} + +void +metaslab_class_destroy(metaslab_class_t *mc) +{ + ASSERT(mc->mc_rotor == NULL); + ASSERT(mc->mc_alloc == 0); + ASSERT(mc->mc_deferred == 0); + ASSERT(mc->mc_space == 0); + ASSERT(mc->mc_dspace == 0); + + for (int i = 0; i < mc->mc_spa->spa_alloc_count; i++) + refcount_destroy(&mc->mc_alloc_slots[i]); + kmem_free(mc->mc_alloc_slots, mc->mc_spa->spa_alloc_count * + sizeof (refcount_t)); + kmem_free(mc->mc_alloc_max_slots, mc->mc_spa->spa_alloc_count * + sizeof (uint64_t)); + mutex_destroy(&mc->mc_lock); + kmem_free(mc, sizeof (metaslab_class_t)); +} + +int +metaslab_class_validate(metaslab_class_t *mc) +{ + metaslab_group_t *mg; + vdev_t *vd; + + /* + * Must hold one of the spa_config locks. + */ + ASSERT(spa_config_held(mc->mc_spa, SCL_ALL, RW_READER) || + spa_config_held(mc->mc_spa, SCL_ALL, RW_WRITER)); + + if ((mg = mc->mc_rotor) == NULL) + return (0); + + do { + vd = mg->mg_vd; + ASSERT(vd->vdev_mg != NULL); + ASSERT3P(vd->vdev_top, ==, vd); + ASSERT3P(mg->mg_class, ==, mc); + ASSERT3P(vd->vdev_ops, !=, &vdev_hole_ops); + } while ((mg = mg->mg_next) != mc->mc_rotor); + + return (0); +} + +void +metaslab_class_space_update(metaslab_class_t *mc, int64_t alloc_delta, + int64_t defer_delta, int64_t space_delta, int64_t dspace_delta) +{ + atomic_add_64(&mc->mc_alloc, alloc_delta); + atomic_add_64(&mc->mc_deferred, defer_delta); + atomic_add_64(&mc->mc_space, space_delta); + atomic_add_64(&mc->mc_dspace, dspace_delta); +} + +void +metaslab_class_minblocksize_update(metaslab_class_t *mc) +{ + metaslab_group_t *mg; + vdev_t *vd; + uint64_t minashift = UINT64_MAX; + + if ((mg = mc->mc_rotor) == NULL) { + mc->mc_minblocksize = SPA_MINBLOCKSIZE; + return; + } + + do { + vd = mg->mg_vd; + if (vd->vdev_ashift < minashift) + minashift = vd->vdev_ashift; + } while ((mg = mg->mg_next) != mc->mc_rotor); + + mc->mc_minblocksize = 1ULL << minashift; +} + +uint64_t +metaslab_class_get_alloc(metaslab_class_t *mc) +{ + return (mc->mc_alloc); +} + +uint64_t +metaslab_class_get_deferred(metaslab_class_t *mc) +{ + return (mc->mc_deferred); +} + +uint64_t +metaslab_class_get_space(metaslab_class_t *mc) +{ + return (mc->mc_space); +} + +uint64_t +metaslab_class_get_dspace(metaslab_class_t *mc) +{ + return (spa_deflate(mc->mc_spa) ? mc->mc_dspace : mc->mc_space); +} + +uint64_t +metaslab_class_get_minblocksize(metaslab_class_t *mc) +{ + return (mc->mc_minblocksize); +} + +void +metaslab_class_histogram_verify(metaslab_class_t *mc) +{ + vdev_t *rvd = mc->mc_spa->spa_root_vdev; + uint64_t *mc_hist; + int i; + + if ((zfs_flags & ZFS_DEBUG_HISTOGRAM_VERIFY) == 0) + return; + + mc_hist = kmem_zalloc(sizeof (uint64_t) * RANGE_TREE_HISTOGRAM_SIZE, + KM_SLEEP); + + for (int c = 0; c < rvd->vdev_children; c++) { + vdev_t *tvd = rvd->vdev_child[c]; + metaslab_group_t *mg = tvd->vdev_mg; + + /* + * Skip any holes, uninitialized top-levels, or + * vdevs that are not in this metalab class. + */ + if (!vdev_is_concrete(tvd) || tvd->vdev_ms_shift == 0 || + mg->mg_class != mc) { + continue; + } + + for (i = 0; i < RANGE_TREE_HISTOGRAM_SIZE; i++) + mc_hist[i] += mg->mg_histogram[i]; + } + + for (i = 0; i < RANGE_TREE_HISTOGRAM_SIZE; i++) + VERIFY3U(mc_hist[i], ==, mc->mc_histogram[i]); + + kmem_free(mc_hist, sizeof (uint64_t) * RANGE_TREE_HISTOGRAM_SIZE); +} + +/* + * Calculate the metaslab class's fragmentation metric. The metric + * is weighted based on the space contribution of each metaslab group. + * The return value will be a number between 0 and 100 (inclusive), or + * ZFS_FRAG_INVALID if the metric has not been set. See comment above the + * zfs_frag_table for more information about the metric. + */ +uint64_t +metaslab_class_fragmentation(metaslab_class_t *mc) +{ + vdev_t *rvd = mc->mc_spa->spa_root_vdev; + uint64_t fragmentation = 0; + + spa_config_enter(mc->mc_spa, SCL_VDEV, FTAG, RW_READER); + + for (int c = 0; c < rvd->vdev_children; c++) { + vdev_t *tvd = rvd->vdev_child[c]; + metaslab_group_t *mg = tvd->vdev_mg; + + /* + * Skip any holes, uninitialized top-levels, + * or vdevs that are not in this metalab class. + */ + if (!vdev_is_concrete(tvd) || tvd->vdev_ms_shift == 0 || + mg->mg_class != mc) { + continue; + } + + /* + * If a metaslab group does not contain a fragmentation + * metric then just bail out. + */ + if (mg->mg_fragmentation == ZFS_FRAG_INVALID) { + spa_config_exit(mc->mc_spa, SCL_VDEV, FTAG); + return (ZFS_FRAG_INVALID); + } + + /* + * Determine how much this metaslab_group is contributing + * to the overall pool fragmentation metric. + */ + fragmentation += mg->mg_fragmentation * + metaslab_group_get_space(mg); + } + fragmentation /= metaslab_class_get_space(mc); + + ASSERT3U(fragmentation, <=, 100); + spa_config_exit(mc->mc_spa, SCL_VDEV, FTAG); + return (fragmentation); +} + +/* + * Calculate the amount of expandable space that is available in + * this metaslab class. If a device is expanded then its expandable + * space will be the amount of allocatable space that is currently not + * part of this metaslab class. + */ +uint64_t +metaslab_class_expandable_space(metaslab_class_t *mc) +{ + vdev_t *rvd = mc->mc_spa->spa_root_vdev; + uint64_t space = 0; + + spa_config_enter(mc->mc_spa, SCL_VDEV, FTAG, RW_READER); + for (int c = 0; c < rvd->vdev_children; c++) { + uint64_t tspace; + vdev_t *tvd = rvd->vdev_child[c]; + metaslab_group_t *mg = tvd->vdev_mg; + + if (!vdev_is_concrete(tvd) || tvd->vdev_ms_shift == 0 || + mg->mg_class != mc) { + continue; + } + + /* + * Calculate if we have enough space to add additional + * metaslabs. We report the expandable space in terms + * of the metaslab size since that's the unit of expansion. + * Adjust by efi system partition size. + */ + tspace = tvd->vdev_max_asize - tvd->vdev_asize; + if (tspace > mc->mc_spa->spa_bootsize) { + tspace -= mc->mc_spa->spa_bootsize; + } + space += P2ALIGN(tspace, 1ULL << tvd->vdev_ms_shift); + } + spa_config_exit(mc->mc_spa, SCL_VDEV, FTAG); + return (space); +} + +static int +metaslab_compare(const void *x1, const void *x2) +{ + const metaslab_t *m1 = (const metaslab_t *)x1; + const metaslab_t *m2 = (const metaslab_t *)x2; + + int sort1 = 0; + int sort2 = 0; + if (m1->ms_allocator != -1 && m1->ms_primary) + sort1 = 1; + else if (m1->ms_allocator != -1 && !m1->ms_primary) + sort1 = 2; + if (m2->ms_allocator != -1 && m2->ms_primary) + sort2 = 1; + else if (m2->ms_allocator != -1 && !m2->ms_primary) + sort2 = 2; + + /* + * Sort inactive metaslabs first, then primaries, then secondaries. When + * selecting a metaslab to allocate from, an allocator first tries its + * primary, then secondary active metaslab. If it doesn't have active + * metaslabs, or can't allocate from them, it searches for an inactive + * metaslab to activate. If it can't find a suitable one, it will steal + * a primary or secondary metaslab from another allocator. + */ + if (sort1 < sort2) + return (-1); + if (sort1 > sort2) + return (1); + + int cmp = AVL_CMP(m2->ms_weight, m1->ms_weight); + if (likely(cmp)) + return (cmp); + + IMPLY(AVL_CMP(m1->ms_start, m2->ms_start) == 0, m1 == m2); + + return (AVL_CMP(m1->ms_start, m2->ms_start)); +} + +/* + * Verify that the space accounting on disk matches the in-core range_trees. + */ +void +metaslab_verify_space(metaslab_t *msp, uint64_t txg) +{ + spa_t *spa = msp->ms_group->mg_vd->vdev_spa; + uint64_t allocated = 0; + uint64_t sm_free_space, msp_free_space; + + ASSERT(MUTEX_HELD(&msp->ms_lock)); + + if ((zfs_flags & ZFS_DEBUG_METASLAB_VERIFY) == 0) + return; + + /* + * We can only verify the metaslab space when we're called + * from syncing context with a loaded metaslab that has an allocated + * space map. Calling this in non-syncing context does not + * provide a consistent view of the metaslab since we're performing + * allocations in the future. + */ + if (txg != spa_syncing_txg(spa) || msp->ms_sm == NULL || + !msp->ms_loaded) + return; + + sm_free_space = msp->ms_size - space_map_allocated(msp->ms_sm) - + space_map_alloc_delta(msp->ms_sm); + + /* + * Account for future allocations since we would have already + * deducted that space from the ms_freetree. + */ + for (int t = 0; t < TXG_CONCURRENT_STATES; t++) { + allocated += + range_tree_space(msp->ms_allocating[(txg + t) & TXG_MASK]); + } + + msp_free_space = range_tree_space(msp->ms_allocatable) + allocated + + msp->ms_deferspace + range_tree_space(msp->ms_freed); + + VERIFY3U(sm_free_space, ==, msp_free_space); +} + +/* + * ========================================================================== + * Metaslab groups + * ========================================================================== + */ +/* + * Update the allocatable flag and the metaslab group's capacity. + * The allocatable flag is set to true if the capacity is below + * the zfs_mg_noalloc_threshold or has a fragmentation value that is + * greater than zfs_mg_fragmentation_threshold. If a metaslab group + * transitions from allocatable to non-allocatable or vice versa then the + * metaslab group's class is updated to reflect the transition. + */ +static void +metaslab_group_alloc_update(metaslab_group_t *mg) +{ + vdev_t *vd = mg->mg_vd; + metaslab_class_t *mc = mg->mg_class; + vdev_stat_t *vs = &vd->vdev_stat; + boolean_t was_allocatable; + boolean_t was_initialized; + + ASSERT(vd == vd->vdev_top); + ASSERT3U(spa_config_held(mc->mc_spa, SCL_ALLOC, RW_READER), ==, + SCL_ALLOC); + + mutex_enter(&mg->mg_lock); + was_allocatable = mg->mg_allocatable; + was_initialized = mg->mg_initialized; + + mg->mg_free_capacity = ((vs->vs_space - vs->vs_alloc) * 100) / + (vs->vs_space + 1); + + mutex_enter(&mc->mc_lock); + + /* + * If the metaslab group was just added then it won't + * have any space until we finish syncing out this txg. + * At that point we will consider it initialized and available + * for allocations. We also don't consider non-activated + * metaslab groups (e.g. vdevs that are in the middle of being removed) + * to be initialized, because they can't be used for allocation. + */ + mg->mg_initialized = metaslab_group_initialized(mg); + if (!was_initialized && mg->mg_initialized) { + mc->mc_groups++; + } else if (was_initialized && !mg->mg_initialized) { + ASSERT3U(mc->mc_groups, >, 0); + mc->mc_groups--; + } + if (mg->mg_initialized) + mg->mg_no_free_space = B_FALSE; + + /* + * A metaslab group is considered allocatable if it has plenty + * of free space or is not heavily fragmented. We only take + * fragmentation into account if the metaslab group has a valid + * fragmentation metric (i.e. a value between 0 and 100). + */ + mg->mg_allocatable = (mg->mg_activation_count > 0 && + mg->mg_free_capacity > zfs_mg_noalloc_threshold && + (mg->mg_fragmentation == ZFS_FRAG_INVALID || + mg->mg_fragmentation <= zfs_mg_fragmentation_threshold)); + + /* + * The mc_alloc_groups maintains a count of the number of + * groups in this metaslab class that are still above the + * zfs_mg_noalloc_threshold. This is used by the allocating + * threads to determine if they should avoid allocations to + * a given group. The allocator will avoid allocations to a group + * if that group has reached or is below the zfs_mg_noalloc_threshold + * and there are still other groups that are above the threshold. + * When a group transitions from allocatable to non-allocatable or + * vice versa we update the metaslab class to reflect that change. + * When the mc_alloc_groups value drops to 0 that means that all + * groups have reached the zfs_mg_noalloc_threshold making all groups + * eligible for allocations. This effectively means that all devices + * are balanced again. + */ + if (was_allocatable && !mg->mg_allocatable) + mc->mc_alloc_groups--; + else if (!was_allocatable && mg->mg_allocatable) + mc->mc_alloc_groups++; + mutex_exit(&mc->mc_lock); + + mutex_exit(&mg->mg_lock); +} + +metaslab_group_t * +metaslab_group_create(metaslab_class_t *mc, vdev_t *vd, int allocators) +{ + metaslab_group_t *mg; + + mg = kmem_zalloc(sizeof (metaslab_group_t), KM_SLEEP); + mutex_init(&mg->mg_lock, NULL, MUTEX_DEFAULT, NULL); + mutex_init(&mg->mg_ms_initialize_lock, NULL, MUTEX_DEFAULT, NULL); + cv_init(&mg->mg_ms_initialize_cv, NULL, CV_DEFAULT, NULL); + mg->mg_primaries = kmem_zalloc(allocators * sizeof (metaslab_t *), + KM_SLEEP); + mg->mg_secondaries = kmem_zalloc(allocators * sizeof (metaslab_t *), + KM_SLEEP); + avl_create(&mg->mg_metaslab_tree, metaslab_compare, + sizeof (metaslab_t), offsetof(struct metaslab, ms_group_node)); + mg->mg_vd = vd; + mg->mg_class = mc; + mg->mg_activation_count = 0; + mg->mg_initialized = B_FALSE; + mg->mg_no_free_space = B_TRUE; + mg->mg_allocators = allocators; + + mg->mg_alloc_queue_depth = kmem_zalloc(allocators * sizeof (refcount_t), + KM_SLEEP); + mg->mg_cur_max_alloc_queue_depth = kmem_zalloc(allocators * + sizeof (uint64_t), KM_SLEEP); + for (int i = 0; i < allocators; i++) { + refcount_create_tracked(&mg->mg_alloc_queue_depth[i]); + mg->mg_cur_max_alloc_queue_depth[i] = 0; + } + + mg->mg_taskq = taskq_create("metaslab_group_taskq", metaslab_load_pct, + minclsyspri, 10, INT_MAX, TASKQ_THREADS_CPU_PCT); + + return (mg); +} + +void +metaslab_group_destroy(metaslab_group_t *mg) +{ + ASSERT(mg->mg_prev == NULL); + ASSERT(mg->mg_next == NULL); + /* + * We may have gone below zero with the activation count + * either because we never activated in the first place or + * because we're done, and possibly removing the vdev. + */ + ASSERT(mg->mg_activation_count <= 0); + + taskq_destroy(mg->mg_taskq); + avl_destroy(&mg->mg_metaslab_tree); + kmem_free(mg->mg_primaries, mg->mg_allocators * sizeof (metaslab_t *)); + kmem_free(mg->mg_secondaries, mg->mg_allocators * + sizeof (metaslab_t *)); + mutex_destroy(&mg->mg_lock); + mutex_destroy(&mg->mg_ms_initialize_lock); + cv_destroy(&mg->mg_ms_initialize_cv); + + for (int i = 0; i < mg->mg_allocators; i++) { + refcount_destroy(&mg->mg_alloc_queue_depth[i]); + mg->mg_cur_max_alloc_queue_depth[i] = 0; + } + kmem_free(mg->mg_alloc_queue_depth, mg->mg_allocators * + sizeof (refcount_t)); + kmem_free(mg->mg_cur_max_alloc_queue_depth, mg->mg_allocators * + sizeof (uint64_t)); + + kmem_free(mg, sizeof (metaslab_group_t)); +} + +void +metaslab_group_activate(metaslab_group_t *mg) +{ + metaslab_class_t *mc = mg->mg_class; + metaslab_group_t *mgprev, *mgnext; + + ASSERT3U(spa_config_held(mc->mc_spa, SCL_ALLOC, RW_WRITER), !=, 0); + + ASSERT(mc->mc_rotor != mg); + ASSERT(mg->mg_prev == NULL); + ASSERT(mg->mg_next == NULL); + ASSERT(mg->mg_activation_count <= 0); + + if (++mg->mg_activation_count <= 0) + return; + + mg->mg_aliquot = metaslab_aliquot * MAX(1, mg->mg_vd->vdev_children); + metaslab_group_alloc_update(mg); + + if ((mgprev = mc->mc_rotor) == NULL) { + mg->mg_prev = mg; + mg->mg_next = mg; + } else { + mgnext = mgprev->mg_next; + mg->mg_prev = mgprev; + mg->mg_next = mgnext; + mgprev->mg_next = mg; + mgnext->mg_prev = mg; + } + mc->mc_rotor = mg; + metaslab_class_minblocksize_update(mc); +} + +/* + * Passivate a metaslab group and remove it from the allocation rotor. + * Callers must hold both the SCL_ALLOC and SCL_ZIO lock prior to passivating + * a metaslab group. This function will momentarily drop spa_config_locks + * that are lower than the SCL_ALLOC lock (see comment below). + */ +void +metaslab_group_passivate(metaslab_group_t *mg) +{ + metaslab_class_t *mc = mg->mg_class; + spa_t *spa = mc->mc_spa; + metaslab_group_t *mgprev, *mgnext; + int locks = spa_config_held(spa, SCL_ALL, RW_WRITER); + + ASSERT3U(spa_config_held(spa, SCL_ALLOC | SCL_ZIO, RW_WRITER), ==, + (SCL_ALLOC | SCL_ZIO)); + + if (--mg->mg_activation_count != 0) { + ASSERT(mc->mc_rotor != mg); + ASSERT(mg->mg_prev == NULL); + ASSERT(mg->mg_next == NULL); + ASSERT(mg->mg_activation_count < 0); + return; + } + + /* + * The spa_config_lock is an array of rwlocks, ordered as + * follows (from highest to lowest): + * SCL_CONFIG > SCL_STATE > SCL_L2ARC > SCL_ALLOC > + * SCL_ZIO > SCL_FREE > SCL_VDEV + * (For more information about the spa_config_lock see spa_misc.c) + * The higher the lock, the broader its coverage. When we passivate + * a metaslab group, we must hold both the SCL_ALLOC and the SCL_ZIO + * config locks. However, the metaslab group's taskq might be trying + * to preload metaslabs so we must drop the SCL_ZIO lock and any + * lower locks to allow the I/O to complete. At a minimum, + * we continue to hold the SCL_ALLOC lock, which prevents any future + * allocations from taking place and any changes to the vdev tree. + */ + spa_config_exit(spa, locks & ~(SCL_ZIO - 1), spa); + taskq_wait(mg->mg_taskq); + spa_config_enter(spa, locks & ~(SCL_ZIO - 1), spa, RW_WRITER); + metaslab_group_alloc_update(mg); + for (int i = 0; i < mg->mg_allocators; i++) { + metaslab_t *msp = mg->mg_primaries[i]; + if (msp != NULL) { + mutex_enter(&msp->ms_lock); + metaslab_passivate(msp, + metaslab_weight_from_range_tree(msp)); + mutex_exit(&msp->ms_lock); + } + msp = mg->mg_secondaries[i]; + if (msp != NULL) { + mutex_enter(&msp->ms_lock); + metaslab_passivate(msp, + metaslab_weight_from_range_tree(msp)); + mutex_exit(&msp->ms_lock); + } + } + + mgprev = mg->mg_prev; + mgnext = mg->mg_next; + + if (mg == mgnext) { + mc->mc_rotor = NULL; + } else { + mc->mc_rotor = mgnext; + mgprev->mg_next = mgnext; + mgnext->mg_prev = mgprev; + } + + mg->mg_prev = NULL; + mg->mg_next = NULL; + metaslab_class_minblocksize_update(mc); +} + +boolean_t +metaslab_group_initialized(metaslab_group_t *mg) +{ + vdev_t *vd = mg->mg_vd; + vdev_stat_t *vs = &vd->vdev_stat; + + return (vs->vs_space != 0 && mg->mg_activation_count > 0); +} + +uint64_t +metaslab_group_get_space(metaslab_group_t *mg) +{ + return ((1ULL << mg->mg_vd->vdev_ms_shift) * mg->mg_vd->vdev_ms_count); +} + +void +metaslab_group_histogram_verify(metaslab_group_t *mg) +{ + uint64_t *mg_hist; + vdev_t *vd = mg->mg_vd; + uint64_t ashift = vd->vdev_ashift; + int i; + + if ((zfs_flags & ZFS_DEBUG_HISTOGRAM_VERIFY) == 0) + return; + + mg_hist = kmem_zalloc(sizeof (uint64_t) * RANGE_TREE_HISTOGRAM_SIZE, + KM_SLEEP); + + ASSERT3U(RANGE_TREE_HISTOGRAM_SIZE, >=, + SPACE_MAP_HISTOGRAM_SIZE + ashift); + + for (int m = 0; m < vd->vdev_ms_count; m++) { + metaslab_t *msp = vd->vdev_ms[m]; + + if (msp->ms_sm == NULL) + continue; + + for (i = 0; i < SPACE_MAP_HISTOGRAM_SIZE; i++) + mg_hist[i + ashift] += + msp->ms_sm->sm_phys->smp_histogram[i]; + } + + for (i = 0; i < RANGE_TREE_HISTOGRAM_SIZE; i ++) + VERIFY3U(mg_hist[i], ==, mg->mg_histogram[i]); + + kmem_free(mg_hist, sizeof (uint64_t) * RANGE_TREE_HISTOGRAM_SIZE); +} + +static void +metaslab_group_histogram_add(metaslab_group_t *mg, metaslab_t *msp) +{ + metaslab_class_t *mc = mg->mg_class; + uint64_t ashift = mg->mg_vd->vdev_ashift; + + ASSERT(MUTEX_HELD(&msp->ms_lock)); + if (msp->ms_sm == NULL) + return; + + mutex_enter(&mg->mg_lock); + for (int i = 0; i < SPACE_MAP_HISTOGRAM_SIZE; i++) { + mg->mg_histogram[i + ashift] += + msp->ms_sm->sm_phys->smp_histogram[i]; + mc->mc_histogram[i + ashift] += + msp->ms_sm->sm_phys->smp_histogram[i]; + } + mutex_exit(&mg->mg_lock); +} + +void +metaslab_group_histogram_remove(metaslab_group_t *mg, metaslab_t *msp) +{ + metaslab_class_t *mc = mg->mg_class; + uint64_t ashift = mg->mg_vd->vdev_ashift; + + ASSERT(MUTEX_HELD(&msp->ms_lock)); + if (msp->ms_sm == NULL) + return; + + mutex_enter(&mg->mg_lock); + for (int i = 0; i < SPACE_MAP_HISTOGRAM_SIZE; i++) { + ASSERT3U(mg->mg_histogram[i + ashift], >=, + msp->ms_sm->sm_phys->smp_histogram[i]); + ASSERT3U(mc->mc_histogram[i + ashift], >=, + msp->ms_sm->sm_phys->smp_histogram[i]); + + mg->mg_histogram[i + ashift] -= + msp->ms_sm->sm_phys->smp_histogram[i]; + mc->mc_histogram[i + ashift] -= + msp->ms_sm->sm_phys->smp_histogram[i]; + } + mutex_exit(&mg->mg_lock); +} + +static void +metaslab_group_add(metaslab_group_t *mg, metaslab_t *msp) +{ + ASSERT(msp->ms_group == NULL); + mutex_enter(&mg->mg_lock); + msp->ms_group = mg; + msp->ms_weight = 0; + avl_add(&mg->mg_metaslab_tree, msp); + mutex_exit(&mg->mg_lock); + + mutex_enter(&msp->ms_lock); + metaslab_group_histogram_add(mg, msp); + mutex_exit(&msp->ms_lock); +} + +static void +metaslab_group_remove(metaslab_group_t *mg, metaslab_t *msp) +{ + mutex_enter(&msp->ms_lock); + metaslab_group_histogram_remove(mg, msp); + mutex_exit(&msp->ms_lock); + + mutex_enter(&mg->mg_lock); + ASSERT(msp->ms_group == mg); + avl_remove(&mg->mg_metaslab_tree, msp); + msp->ms_group = NULL; + mutex_exit(&mg->mg_lock); +} + +static void +metaslab_group_sort_impl(metaslab_group_t *mg, metaslab_t *msp, uint64_t weight) +{ + ASSERT(MUTEX_HELD(&mg->mg_lock)); + ASSERT(msp->ms_group == mg); + avl_remove(&mg->mg_metaslab_tree, msp); + msp->ms_weight = weight; + avl_add(&mg->mg_metaslab_tree, msp); + +} + +static void +metaslab_group_sort(metaslab_group_t *mg, metaslab_t *msp, uint64_t weight) +{ + /* + * Although in principle the weight can be any value, in + * practice we do not use values in the range [1, 511]. + */ + ASSERT(weight >= SPA_MINBLOCKSIZE || weight == 0); + ASSERT(MUTEX_HELD(&msp->ms_lock)); + + mutex_enter(&mg->mg_lock); + metaslab_group_sort_impl(mg, msp, weight); + mutex_exit(&mg->mg_lock); +} + +/* + * Calculate the fragmentation for a given metaslab group. We can use + * a simple average here since all metaslabs within the group must have + * the same size. The return value will be a value between 0 and 100 + * (inclusive), or ZFS_FRAG_INVALID if less than half of the metaslab in this + * group have a fragmentation metric. + */ +uint64_t +metaslab_group_fragmentation(metaslab_group_t *mg) +{ + vdev_t *vd = mg->mg_vd; + uint64_t fragmentation = 0; + uint64_t valid_ms = 0; + + for (int m = 0; m < vd->vdev_ms_count; m++) { + metaslab_t *msp = vd->vdev_ms[m]; + + if (msp->ms_fragmentation == ZFS_FRAG_INVALID) + continue; + + valid_ms++; + fragmentation += msp->ms_fragmentation; + } + + if (valid_ms <= vd->vdev_ms_count / 2) + return (ZFS_FRAG_INVALID); + + fragmentation /= valid_ms; + ASSERT3U(fragmentation, <=, 100); + return (fragmentation); +} + +/* + * Determine if a given metaslab group should skip allocations. A metaslab + * group should avoid allocations if its free capacity is less than the + * zfs_mg_noalloc_threshold or its fragmentation metric is greater than + * zfs_mg_fragmentation_threshold and there is at least one metaslab group + * that can still handle allocations. If the allocation throttle is enabled + * then we skip allocations to devices that have reached their maximum + * allocation queue depth unless the selected metaslab group is the only + * eligible group remaining. + */ +static boolean_t +metaslab_group_allocatable(metaslab_group_t *mg, metaslab_group_t *rotor, + uint64_t psize, int allocator, int d) +{ + spa_t *spa = mg->mg_vd->vdev_spa; + metaslab_class_t *mc = mg->mg_class; + + /* + * We can only consider skipping this metaslab group if it's + * in the normal metaslab class and there are other metaslab + * groups to select from. Otherwise, we always consider it eligible + * for allocations. + */ + if (mc != spa_normal_class(spa) || mc->mc_groups <= 1) + return (B_TRUE); + + /* + * If the metaslab group's mg_allocatable flag is set (see comments + * in metaslab_group_alloc_update() for more information) and + * the allocation throttle is disabled then allow allocations to this + * device. However, if the allocation throttle is enabled then + * check if we have reached our allocation limit (mg_alloc_queue_depth) + * to determine if we should allow allocations to this metaslab group. + * If all metaslab groups are no longer considered allocatable + * (mc_alloc_groups == 0) or we're trying to allocate the smallest + * gang block size then we allow allocations on this metaslab group + * regardless of the mg_allocatable or throttle settings. + */ + if (mg->mg_allocatable) { + metaslab_group_t *mgp; + int64_t qdepth; + uint64_t qmax = mg->mg_cur_max_alloc_queue_depth[allocator]; + + if (!mc->mc_alloc_throttle_enabled) + return (B_TRUE); + + /* + * If this metaslab group does not have any free space, then + * there is no point in looking further. + */ + if (mg->mg_no_free_space) + return (B_FALSE); + + /* + * Relax allocation throttling for ditto blocks. Due to + * random imbalances in allocation it tends to push copies + * to one vdev, that looks a bit better at the moment. + */ + qmax = qmax * (4 + d) / 4; + + qdepth = refcount_count(&mg->mg_alloc_queue_depth[allocator]); + + /* + * If this metaslab group is below its qmax or it's + * the only allocatable metasable group, then attempt + * to allocate from it. + */ + if (qdepth < qmax || mc->mc_alloc_groups == 1) + return (B_TRUE); + ASSERT3U(mc->mc_alloc_groups, >, 1); + + /* + * Since this metaslab group is at or over its qmax, we + * need to determine if there are metaslab groups after this + * one that might be able to handle this allocation. This is + * racy since we can't hold the locks for all metaslab + * groups at the same time when we make this check. + */ + for (mgp = mg->mg_next; mgp != rotor; mgp = mgp->mg_next) { + qmax = mgp->mg_cur_max_alloc_queue_depth[allocator]; + qmax = qmax * (4 + d) / 4; + qdepth = refcount_count( + &mgp->mg_alloc_queue_depth[allocator]); + + /* + * If there is another metaslab group that + * might be able to handle the allocation, then + * we return false so that we skip this group. + */ + if (qdepth < qmax && !mgp->mg_no_free_space) + return (B_FALSE); + } + + /* + * We didn't find another group to handle the allocation + * so we can't skip this metaslab group even though + * we are at or over our qmax. + */ + return (B_TRUE); + + } else if (mc->mc_alloc_groups == 0 || psize == SPA_MINBLOCKSIZE) { + return (B_TRUE); + } + return (B_FALSE); +} + +/* + * ========================================================================== + * Range tree callbacks + * ========================================================================== + */ + +/* + * Comparison function for the private size-ordered tree. Tree is sorted + * by size, larger sizes at the end of the tree. + */ +static int +metaslab_rangesize_compare(const void *x1, const void *x2) +{ + const range_seg_t *r1 = x1; + const range_seg_t *r2 = x2; + uint64_t rs_size1 = r1->rs_end - r1->rs_start; + uint64_t rs_size2 = r2->rs_end - r2->rs_start; + + int cmp = AVL_CMP(rs_size1, rs_size2); + if (likely(cmp)) + return (cmp); + + if (r1->rs_start < r2->rs_start) + return (-1); + + return (AVL_CMP(r1->rs_start, r2->rs_start)); +} + +/* + * ========================================================================== + * Common allocator routines + * ========================================================================== + */ + +/* + * Return the maximum contiguous segment within the metaslab. + */ +uint64_t +metaslab_block_maxsize(metaslab_t *msp) +{ + avl_tree_t *t = &msp->ms_allocatable_by_size; + range_seg_t *rs; + + if (t == NULL || (rs = avl_last(t)) == NULL) + return (0ULL); + + return (rs->rs_end - rs->rs_start); +} + +static range_seg_t * +metaslab_block_find(avl_tree_t *t, uint64_t start, uint64_t size) +{ + range_seg_t *rs, rsearch; + avl_index_t where; + + rsearch.rs_start = start; + rsearch.rs_end = start + size; + + rs = avl_find(t, &rsearch, &where); + if (rs == NULL) { + rs = avl_nearest(t, where, AVL_AFTER); + } + + return (rs); +} + +/* + * This is a helper function that can be used by the allocator to find + * a suitable block to allocate. This will search the specified AVL + * tree looking for a block that matches the specified criteria. + */ +static uint64_t +metaslab_block_picker(avl_tree_t *t, uint64_t *cursor, uint64_t size, + uint64_t align) +{ + range_seg_t *rs = metaslab_block_find(t, *cursor, size); + + while (rs != NULL) { + uint64_t offset = P2ROUNDUP(rs->rs_start, align); + + if (offset + size <= rs->rs_end) { + *cursor = offset + size; + return (offset); + } + rs = AVL_NEXT(t, rs); + } + + /* + * If we know we've searched the whole map (*cursor == 0), give up. + * Otherwise, reset the cursor to the beginning and try again. + */ + if (*cursor == 0) + return (-1ULL); + + *cursor = 0; + return (metaslab_block_picker(t, cursor, size, align)); +} + +/* + * ========================================================================== + * The first-fit block allocator + * ========================================================================== + */ +static uint64_t +metaslab_ff_alloc(metaslab_t *msp, uint64_t size) +{ + /* + * Find the largest power of 2 block size that evenly divides the + * requested size. This is used to try to allocate blocks with similar + * alignment from the same area of the metaslab (i.e. same cursor + * bucket) but it does not guarantee that other allocations sizes + * may exist in the same region. + */ + uint64_t align = size & -size; + uint64_t *cursor = &msp->ms_lbas[highbit64(align) - 1]; + avl_tree_t *t = &msp->ms_allocatable->rt_root; + + return (metaslab_block_picker(t, cursor, size, align)); +} + +static metaslab_ops_t metaslab_ff_ops = { + metaslab_ff_alloc +}; + +/* + * ========================================================================== + * Dynamic block allocator - + * Uses the first fit allocation scheme until space get low and then + * adjusts to a best fit allocation method. Uses metaslab_df_alloc_threshold + * and metaslab_df_free_pct to determine when to switch the allocation scheme. + * ========================================================================== + */ +static uint64_t +metaslab_df_alloc(metaslab_t *msp, uint64_t size) +{ + /* + * Find the largest power of 2 block size that evenly divides the + * requested size. This is used to try to allocate blocks with similar + * alignment from the same area of the metaslab (i.e. same cursor + * bucket) but it does not guarantee that other allocations sizes + * may exist in the same region. + */ + uint64_t align = size & -size; + uint64_t *cursor = &msp->ms_lbas[highbit64(align) - 1]; + range_tree_t *rt = msp->ms_allocatable; + avl_tree_t *t = &rt->rt_root; + uint64_t max_size = metaslab_block_maxsize(msp); + int free_pct = range_tree_space(rt) * 100 / msp->ms_size; + + ASSERT(MUTEX_HELD(&msp->ms_lock)); + ASSERT3U(avl_numnodes(t), ==, + avl_numnodes(&msp->ms_allocatable_by_size)); + + if (max_size < size) + return (-1ULL); + + /* + * If we're running low on space switch to using the size + * sorted AVL tree (best-fit). + */ + if (max_size < metaslab_df_alloc_threshold || + free_pct < metaslab_df_free_pct) { + t = &msp->ms_allocatable_by_size; + *cursor = 0; + } + + return (metaslab_block_picker(t, cursor, size, 1ULL)); +} + +static metaslab_ops_t metaslab_df_ops = { + metaslab_df_alloc +}; + +/* + * ========================================================================== + * Cursor fit block allocator - + * Select the largest region in the metaslab, set the cursor to the beginning + * of the range and the cursor_end to the end of the range. As allocations + * are made advance the cursor. Continue allocating from the cursor until + * the range is exhausted and then find a new range. + * ========================================================================== + */ +static uint64_t +metaslab_cf_alloc(metaslab_t *msp, uint64_t size) +{ + range_tree_t *rt = msp->ms_allocatable; + avl_tree_t *t = &msp->ms_allocatable_by_size; + uint64_t *cursor = &msp->ms_lbas[0]; + uint64_t *cursor_end = &msp->ms_lbas[1]; + uint64_t offset = 0; + + ASSERT(MUTEX_HELD(&msp->ms_lock)); + ASSERT3U(avl_numnodes(t), ==, avl_numnodes(&rt->rt_root)); + + ASSERT3U(*cursor_end, >=, *cursor); + + if ((*cursor + size) > *cursor_end) { + range_seg_t *rs; + + rs = avl_last(&msp->ms_allocatable_by_size); + if (rs == NULL || (rs->rs_end - rs->rs_start) < size) + return (-1ULL); + + *cursor = rs->rs_start; + *cursor_end = rs->rs_end; + } + + offset = *cursor; + *cursor += size; + + return (offset); +} + +static metaslab_ops_t metaslab_cf_ops = { + metaslab_cf_alloc +}; + +/* + * ========================================================================== + * New dynamic fit allocator - + * Select a region that is large enough to allocate 2^metaslab_ndf_clump_shift + * contiguous blocks. If no region is found then just use the largest segment + * that remains. + * ========================================================================== + */ + +/* + * Determines desired number of contiguous blocks (2^metaslab_ndf_clump_shift) + * to request from the allocator. + */ +uint64_t metaslab_ndf_clump_shift = 4; + +static uint64_t +metaslab_ndf_alloc(metaslab_t *msp, uint64_t size) +{ + avl_tree_t *t = &msp->ms_allocatable->rt_root; + avl_index_t where; + range_seg_t *rs, rsearch; + uint64_t hbit = highbit64(size); + uint64_t *cursor = &msp->ms_lbas[hbit - 1]; + uint64_t max_size = metaslab_block_maxsize(msp); + + ASSERT(MUTEX_HELD(&msp->ms_lock)); + ASSERT3U(avl_numnodes(t), ==, + avl_numnodes(&msp->ms_allocatable_by_size)); + + if (max_size < size) + return (-1ULL); + + rsearch.rs_start = *cursor; + rsearch.rs_end = *cursor + size; + + rs = avl_find(t, &rsearch, &where); + if (rs == NULL || (rs->rs_end - rs->rs_start) < size) { + t = &msp->ms_allocatable_by_size; + + rsearch.rs_start = 0; + rsearch.rs_end = MIN(max_size, + 1ULL << (hbit + metaslab_ndf_clump_shift)); + rs = avl_find(t, &rsearch, &where); + if (rs == NULL) + rs = avl_nearest(t, where, AVL_AFTER); + ASSERT(rs != NULL); + } + + if ((rs->rs_end - rs->rs_start) >= size) { + *cursor = rs->rs_start + size; + return (rs->rs_start); + } + return (-1ULL); +} + +static metaslab_ops_t metaslab_ndf_ops = { + metaslab_ndf_alloc +}; + +metaslab_ops_t *zfs_metaslab_ops = &metaslab_df_ops; + +/* + * ========================================================================== + * Metaslabs + * ========================================================================== + */ + +/* + * Wait for any in-progress metaslab loads to complete. + */ +void +metaslab_load_wait(metaslab_t *msp) +{ + ASSERT(MUTEX_HELD(&msp->ms_lock)); + + while (msp->ms_loading) { + ASSERT(!msp->ms_loaded); + cv_wait(&msp->ms_load_cv, &msp->ms_lock); + } +} + +int +metaslab_load(metaslab_t *msp) +{ + int error = 0; + boolean_t success = B_FALSE; + + ASSERT(MUTEX_HELD(&msp->ms_lock)); + ASSERT(!msp->ms_loaded); + ASSERT(!msp->ms_loading); + + msp->ms_loading = B_TRUE; + /* + * Nobody else can manipulate a loading metaslab, so it's now safe + * to drop the lock. This way we don't have to hold the lock while + * reading the spacemap from disk. + */ + mutex_exit(&msp->ms_lock); + + /* + * If the space map has not been allocated yet, then treat + * all the space in the metaslab as free and add it to ms_allocatable. + */ + if (msp->ms_sm != NULL) { + error = space_map_load(msp->ms_sm, msp->ms_allocatable, + SM_FREE); + } else { + range_tree_add(msp->ms_allocatable, + msp->ms_start, msp->ms_size); + } + + success = (error == 0); + + mutex_enter(&msp->ms_lock); + msp->ms_loading = B_FALSE; + + if (success) { + ASSERT3P(msp->ms_group, !=, NULL); + msp->ms_loaded = B_TRUE; + + /* + * If the metaslab already has a spacemap, then we need to + * remove all segments from the defer tree; otherwise, the + * metaslab is completely empty and we can skip this. + */ + if (msp->ms_sm != NULL) { + for (int t = 0; t < TXG_DEFER_SIZE; t++) { + range_tree_walk(msp->ms_defer[t], + range_tree_remove, msp->ms_allocatable); + } + } + msp->ms_max_size = metaslab_block_maxsize(msp); + } + cv_broadcast(&msp->ms_load_cv); + return (error); +} + +void +metaslab_unload(metaslab_t *msp) +{ + ASSERT(MUTEX_HELD(&msp->ms_lock)); + range_tree_vacate(msp->ms_allocatable, NULL, NULL); + msp->ms_loaded = B_FALSE; + msp->ms_weight &= ~METASLAB_ACTIVE_MASK; + msp->ms_max_size = 0; +} + +int +metaslab_init(metaslab_group_t *mg, uint64_t id, uint64_t object, uint64_t txg, + metaslab_t **msp) +{ + vdev_t *vd = mg->mg_vd; + objset_t *mos = vd->vdev_spa->spa_meta_objset; + metaslab_t *ms; + int error; + + ms = kmem_zalloc(sizeof (metaslab_t), KM_SLEEP); + mutex_init(&ms->ms_lock, NULL, MUTEX_DEFAULT, NULL); + mutex_init(&ms->ms_sync_lock, NULL, MUTEX_DEFAULT, NULL); + cv_init(&ms->ms_load_cv, NULL, CV_DEFAULT, NULL); + + ms->ms_id = id; + ms->ms_start = id << vd->vdev_ms_shift; + ms->ms_size = 1ULL << vd->vdev_ms_shift; + ms->ms_allocator = -1; + ms->ms_new = B_TRUE; + + /* + * We only open space map objects that already exist. All others + * will be opened when we finally allocate an object for it. + */ + if (object != 0) { + error = space_map_open(&ms->ms_sm, mos, object, ms->ms_start, + ms->ms_size, vd->vdev_ashift); + + if (error != 0) { + kmem_free(ms, sizeof (metaslab_t)); + return (error); + } + + ASSERT(ms->ms_sm != NULL); + } + + /* + * We create the main range tree here, but we don't create the + * other range trees until metaslab_sync_done(). This serves + * two purposes: it allows metaslab_sync_done() to detect the + * addition of new space; and for debugging, it ensures that we'd + * data fault on any attempt to use this metaslab before it's ready. + */ + ms->ms_allocatable = range_tree_create_impl(&rt_avl_ops, &ms->ms_allocatable_by_size, + metaslab_rangesize_compare, 0); + metaslab_group_add(mg, ms); + + metaslab_set_fragmentation(ms); + + /* + * If we're opening an existing pool (txg == 0) or creating + * a new one (txg == TXG_INITIAL), all space is available now. + * If we're adding space to an existing pool, the new space + * does not become available until after this txg has synced. + * The metaslab's weight will also be initialized when we sync + * out this txg. This ensures that we don't attempt to allocate + * from it before we have initialized it completely. + */ + if (txg <= TXG_INITIAL) + metaslab_sync_done(ms, 0); + + /* + * If metaslab_debug_load is set and we're initializing a metaslab + * that has an allocated space map object then load the its space + * map so that can verify frees. + */ + if (metaslab_debug_load && ms->ms_sm != NULL) { + mutex_enter(&ms->ms_lock); + VERIFY0(metaslab_load(ms)); + mutex_exit(&ms->ms_lock); + } + + if (txg != 0) { + vdev_dirty(vd, 0, NULL, txg); + vdev_dirty(vd, VDD_METASLAB, ms, txg); + } + + *msp = ms; + + return (0); +} + +void +metaslab_fini(metaslab_t *msp) +{ + metaslab_group_t *mg = msp->ms_group; + + metaslab_group_remove(mg, msp); + + mutex_enter(&msp->ms_lock); + VERIFY(msp->ms_group == NULL); + vdev_space_update(mg->mg_vd, -space_map_allocated(msp->ms_sm), + 0, -msp->ms_size); + space_map_close(msp->ms_sm); + + metaslab_unload(msp); + range_tree_destroy(msp->ms_allocatable); + range_tree_destroy(msp->ms_freeing); + range_tree_destroy(msp->ms_freed); + + for (int t = 0; t < TXG_SIZE; t++) { + range_tree_destroy(msp->ms_allocating[t]); + } + + for (int t = 0; t < TXG_DEFER_SIZE; t++) { + range_tree_destroy(msp->ms_defer[t]); + } + ASSERT0(msp->ms_deferspace); + + range_tree_destroy(msp->ms_checkpointing); + + mutex_exit(&msp->ms_lock); + cv_destroy(&msp->ms_load_cv); + mutex_destroy(&msp->ms_lock); + mutex_destroy(&msp->ms_sync_lock); + ASSERT3U(msp->ms_allocator, ==, -1); + + kmem_free(msp, sizeof (metaslab_t)); +} + +#define FRAGMENTATION_TABLE_SIZE 17 + +/* + * This table defines a segment size based fragmentation metric that will + * allow each metaslab to derive its own fragmentation value. This is done + * by calculating the space in each bucket of the spacemap histogram and + * multiplying that by the fragmetation metric in this table. Doing + * this for all buckets and dividing it by the total amount of free + * space in this metaslab (i.e. the total free space in all buckets) gives + * us the fragmentation metric. This means that a high fragmentation metric + * equates to most of the free space being comprised of small segments. + * Conversely, if the metric is low, then most of the free space is in + * large segments. A 10% change in fragmentation equates to approximately + * double the number of segments. + * + * This table defines 0% fragmented space using 16MB segments. Testing has + * shown that segments that are greater than or equal to 16MB do not suffer + * from drastic performance problems. Using this value, we derive the rest + * of the table. Since the fragmentation value is never stored on disk, it + * is possible to change these calculations in the future. + */ +int zfs_frag_table[FRAGMENTATION_TABLE_SIZE] = { + 100, /* 512B */ + 100, /* 1K */ + 98, /* 2K */ + 95, /* 4K */ + 90, /* 8K */ + 80, /* 16K */ + 70, /* 32K */ + 60, /* 64K */ + 50, /* 128K */ + 40, /* 256K */ + 30, /* 512K */ + 20, /* 1M */ + 15, /* 2M */ + 10, /* 4M */ + 5, /* 8M */ + 0 /* 16M */ +}; + +/* + * Calclate the metaslab's fragmentation metric. A return value + * of ZFS_FRAG_INVALID means that the metaslab has not been upgraded and does + * not support this metric. Otherwise, the return value should be in the + * range [0, 100]. + */ +static void +metaslab_set_fragmentation(metaslab_t *msp) +{ + spa_t *spa = msp->ms_group->mg_vd->vdev_spa; + uint64_t fragmentation = 0; + uint64_t total = 0; + boolean_t feature_enabled = spa_feature_is_enabled(spa, + SPA_FEATURE_SPACEMAP_HISTOGRAM); + + if (!feature_enabled) { + msp->ms_fragmentation = ZFS_FRAG_INVALID; + return; + } + + /* + * A null space map means that the entire metaslab is free + * and thus is not fragmented. + */ + if (msp->ms_sm == NULL) { + msp->ms_fragmentation = 0; + return; + } + + /* + * If this metaslab's space map has not been upgraded, flag it + * so that we upgrade next time we encounter it. + */ + if (msp->ms_sm->sm_dbuf->db_size != sizeof (space_map_phys_t)) { + uint64_t txg = spa_syncing_txg(spa); + vdev_t *vd = msp->ms_group->mg_vd; + + /* + * If we've reached the final dirty txg, then we must + * be shutting down the pool. We don't want to dirty + * any data past this point so skip setting the condense + * flag. We can retry this action the next time the pool + * is imported. + */ + if (spa_writeable(spa) && txg < spa_final_dirty_txg(spa)) { + msp->ms_condense_wanted = B_TRUE; + vdev_dirty(vd, VDD_METASLAB, msp, txg + 1); + zfs_dbgmsg("txg %llu, requesting force condense: " + "ms_id %llu, vdev_id %llu", txg, msp->ms_id, + vd->vdev_id); + } + msp->ms_fragmentation = ZFS_FRAG_INVALID; + return; + } + + for (int i = 0; i < SPACE_MAP_HISTOGRAM_SIZE; i++) { + uint64_t space = 0; + uint8_t shift = msp->ms_sm->sm_shift; + + int idx = MIN(shift - SPA_MINBLOCKSHIFT + i, + FRAGMENTATION_TABLE_SIZE - 1); + + if (msp->ms_sm->sm_phys->smp_histogram[i] == 0) + continue; + + space = msp->ms_sm->sm_phys->smp_histogram[i] << (i + shift); + total += space; + + ASSERT3U(idx, <, FRAGMENTATION_TABLE_SIZE); + fragmentation += space * zfs_frag_table[idx]; + } + + if (total > 0) + fragmentation /= total; + ASSERT3U(fragmentation, <=, 100); + + msp->ms_fragmentation = fragmentation; +} + +/* + * Compute a weight -- a selection preference value -- for the given metaslab. + * This is based on the amount of free space, the level of fragmentation, + * the LBA range, and whether the metaslab is loaded. + */ +static uint64_t +metaslab_space_weight(metaslab_t *msp) +{ + metaslab_group_t *mg = msp->ms_group; + vdev_t *vd = mg->mg_vd; + uint64_t weight, space; + + ASSERT(MUTEX_HELD(&msp->ms_lock)); + ASSERT(!vd->vdev_removing); + + /* + * The baseline weight is the metaslab's free space. + */ + space = msp->ms_size - space_map_allocated(msp->ms_sm); + + if (metaslab_fragmentation_factor_enabled && + msp->ms_fragmentation != ZFS_FRAG_INVALID) { + /* + * Use the fragmentation information to inversely scale + * down the baseline weight. We need to ensure that we + * don't exclude this metaslab completely when it's 100% + * fragmented. To avoid this we reduce the fragmented value + * by 1. + */ + space = (space * (100 - (msp->ms_fragmentation - 1))) / 100; + + /* + * If space < SPA_MINBLOCKSIZE, then we will not allocate from + * this metaslab again. The fragmentation metric may have + * decreased the space to something smaller than + * SPA_MINBLOCKSIZE, so reset the space to SPA_MINBLOCKSIZE + * so that we can consume any remaining space. + */ + if (space > 0 && space < SPA_MINBLOCKSIZE) + space = SPA_MINBLOCKSIZE; + } + weight = space; + + /* + * Modern disks have uniform bit density and constant angular velocity. + * Therefore, the outer recording zones are faster (higher bandwidth) + * than the inner zones by the ratio of outer to inner track diameter, + * which is typically around 2:1. We account for this by assigning + * higher weight to lower metaslabs (multiplier ranging from 2x to 1x). + * In effect, this means that we'll select the metaslab with the most + * free bandwidth rather than simply the one with the most free space. + */ + if (!vd->vdev_nonrot && metaslab_lba_weighting_enabled) { + weight = 2 * weight - (msp->ms_id * weight) / vd->vdev_ms_count; + ASSERT(weight >= space && weight <= 2 * space); + } + + /* + * If this metaslab is one we're actively using, adjust its + * weight to make it preferable to any inactive metaslab so + * we'll polish it off. If the fragmentation on this metaslab + * has exceed our threshold, then don't mark it active. + */ + if (msp->ms_loaded && msp->ms_fragmentation != ZFS_FRAG_INVALID && + msp->ms_fragmentation <= zfs_metaslab_fragmentation_threshold) { + weight |= (msp->ms_weight & METASLAB_ACTIVE_MASK); + } + + WEIGHT_SET_SPACEBASED(weight); + return (weight); +} + +/* + * Return the weight of the specified metaslab, according to the segment-based + * weighting algorithm. The metaslab must be loaded. This function can + * be called within a sync pass since it relies only on the metaslab's + * range tree which is always accurate when the metaslab is loaded. + */ +static uint64_t +metaslab_weight_from_range_tree(metaslab_t *msp) +{ + uint64_t weight = 0; + uint32_t segments = 0; + + ASSERT(msp->ms_loaded); + + for (int i = RANGE_TREE_HISTOGRAM_SIZE - 1; i >= SPA_MINBLOCKSHIFT; + i--) { + uint8_t shift = msp->ms_group->mg_vd->vdev_ashift; + int max_idx = SPACE_MAP_HISTOGRAM_SIZE + shift - 1; + + segments <<= 1; + segments += msp->ms_allocatable->rt_histogram[i]; + + /* + * The range tree provides more precision than the space map + * and must be downgraded so that all values fit within the + * space map's histogram. This allows us to compare loaded + * vs. unloaded metaslabs to determine which metaslab is + * considered "best". + */ + if (i > max_idx) + continue; + + if (segments != 0) { + WEIGHT_SET_COUNT(weight, segments); + WEIGHT_SET_INDEX(weight, i); + WEIGHT_SET_ACTIVE(weight, 0); + break; + } + } + return (weight); +} + +/* + * Calculate the weight based on the on-disk histogram. This should only + * be called after a sync pass has completely finished since the on-disk + * information is updated in metaslab_sync(). + */ +static uint64_t +metaslab_weight_from_spacemap(metaslab_t *msp) +{ + uint64_t weight = 0; + + for (int i = SPACE_MAP_HISTOGRAM_SIZE - 1; i >= 0; i--) { + if (msp->ms_sm->sm_phys->smp_histogram[i] != 0) { + WEIGHT_SET_COUNT(weight, + msp->ms_sm->sm_phys->smp_histogram[i]); + WEIGHT_SET_INDEX(weight, i + + msp->ms_sm->sm_shift); + WEIGHT_SET_ACTIVE(weight, 0); + break; + } + } + return (weight); +} + +/* + * Compute a segment-based weight for the specified metaslab. The weight + * is determined by highest bucket in the histogram. The information + * for the highest bucket is encoded into the weight value. + */ +static uint64_t +metaslab_segment_weight(metaslab_t *msp) +{ + metaslab_group_t *mg = msp->ms_group; + uint64_t weight = 0; + uint8_t shift = mg->mg_vd->vdev_ashift; + + ASSERT(MUTEX_HELD(&msp->ms_lock)); + + /* + * The metaslab is completely free. + */ + if (space_map_allocated(msp->ms_sm) == 0) { + int idx = highbit64(msp->ms_size) - 1; + int max_idx = SPACE_MAP_HISTOGRAM_SIZE + shift - 1; + + if (idx < max_idx) { + WEIGHT_SET_COUNT(weight, 1ULL); + WEIGHT_SET_INDEX(weight, idx); + } else { + WEIGHT_SET_COUNT(weight, 1ULL << (idx - max_idx)); + WEIGHT_SET_INDEX(weight, max_idx); + } + WEIGHT_SET_ACTIVE(weight, 0); + ASSERT(!WEIGHT_IS_SPACEBASED(weight)); + + return (weight); + } + + ASSERT3U(msp->ms_sm->sm_dbuf->db_size, ==, sizeof (space_map_phys_t)); + + /* + * If the metaslab is fully allocated then just make the weight 0. + */ + if (space_map_allocated(msp->ms_sm) == msp->ms_size) + return (0); + /* + * If the metaslab is already loaded, then use the range tree to + * determine the weight. Otherwise, we rely on the space map information + * to generate the weight. + */ + if (msp->ms_loaded) { + weight = metaslab_weight_from_range_tree(msp); + } else { + weight = metaslab_weight_from_spacemap(msp); + } + + /* + * If the metaslab was active the last time we calculated its weight + * then keep it active. We want to consume the entire region that + * is associated with this weight. + */ + if (msp->ms_activation_weight != 0 && weight != 0) + WEIGHT_SET_ACTIVE(weight, WEIGHT_GET_ACTIVE(msp->ms_weight)); + return (weight); +} + +/* + * Determine if we should attempt to allocate from this metaslab. If the + * metaslab has a maximum size then we can quickly determine if the desired + * allocation size can be satisfied. Otherwise, if we're using segment-based + * weighting then we can determine the maximum allocation that this metaslab + * can accommodate based on the index encoded in the weight. If we're using + * space-based weights then rely on the entire weight (excluding the weight + * type bit). + */ +boolean_t +metaslab_should_allocate(metaslab_t *msp, uint64_t asize) +{ + boolean_t should_allocate; + + if (msp->ms_max_size != 0) + return (msp->ms_max_size >= asize); + + if (!WEIGHT_IS_SPACEBASED(msp->ms_weight)) { + /* + * The metaslab segment weight indicates segments in the + * range [2^i, 2^(i+1)), where i is the index in the weight. + * Since the asize might be in the middle of the range, we + * should attempt the allocation if asize < 2^(i+1). + */ + should_allocate = (asize < + 1ULL << (WEIGHT_GET_INDEX(msp->ms_weight) + 1)); + } else { + should_allocate = (asize <= + (msp->ms_weight & ~METASLAB_WEIGHT_TYPE)); + } + return (should_allocate); +} + +static uint64_t +metaslab_weight(metaslab_t *msp) +{ + vdev_t *vd = msp->ms_group->mg_vd; + spa_t *spa = vd->vdev_spa; + uint64_t weight; + + ASSERT(MUTEX_HELD(&msp->ms_lock)); + + /* + * If this vdev is in the process of being removed, there is nothing + * for us to do here. + */ + if (vd->vdev_removing) + return (0); + + metaslab_set_fragmentation(msp); + + /* + * Update the maximum size if the metaslab is loaded. This will + * ensure that we get an accurate maximum size if newly freed space + * has been added back into the free tree. + */ + if (msp->ms_loaded) + msp->ms_max_size = metaslab_block_maxsize(msp); + + /* + * Segment-based weighting requires space map histogram support. + */ + if (zfs_metaslab_segment_weight_enabled && + spa_feature_is_enabled(spa, SPA_FEATURE_SPACEMAP_HISTOGRAM) && + (msp->ms_sm == NULL || msp->ms_sm->sm_dbuf->db_size == + sizeof (space_map_phys_t))) { + weight = metaslab_segment_weight(msp); + } else { + weight = metaslab_space_weight(msp); + } + return (weight); +} + +static int +metaslab_activate_allocator(metaslab_group_t *mg, metaslab_t *msp, + int allocator, uint64_t activation_weight) +{ + /* + * If we're activating for the claim code, we don't want to actually + * set the metaslab up for a specific allocator. + */ + if (activation_weight == METASLAB_WEIGHT_CLAIM) + return (0); + metaslab_t **arr = (activation_weight == METASLAB_WEIGHT_PRIMARY ? + mg->mg_primaries : mg->mg_secondaries); + + ASSERT(MUTEX_HELD(&msp->ms_lock)); + mutex_enter(&mg->mg_lock); + if (arr[allocator] != NULL) { + mutex_exit(&mg->mg_lock); + return (EEXIST); + } + + arr[allocator] = msp; + ASSERT3S(msp->ms_allocator, ==, -1); + msp->ms_allocator = allocator; + msp->ms_primary = (activation_weight == METASLAB_WEIGHT_PRIMARY); + mutex_exit(&mg->mg_lock); + + return (0); +} + +static int +metaslab_activate(metaslab_t *msp, int allocator, uint64_t activation_weight) +{ + ASSERT(MUTEX_HELD(&msp->ms_lock)); + + if ((msp->ms_weight & METASLAB_ACTIVE_MASK) == 0) { + int error = 0; + metaslab_load_wait(msp); + if (!msp->ms_loaded) { + if ((error = metaslab_load(msp)) != 0) { + metaslab_group_sort(msp->ms_group, msp, 0); + return (error); + } + } + if ((msp->ms_weight & METASLAB_ACTIVE_MASK) != 0) { + /* + * The metaslab was activated for another allocator + * while we were waiting, we should reselect. + */ + return (EBUSY); + } + if ((error = metaslab_activate_allocator(msp->ms_group, msp, + allocator, activation_weight)) != 0) { + return (error); + } + + msp->ms_activation_weight = msp->ms_weight; + metaslab_group_sort(msp->ms_group, msp, + msp->ms_weight | activation_weight); + } + ASSERT(msp->ms_loaded); + ASSERT(msp->ms_weight & METASLAB_ACTIVE_MASK); + + return (0); +} + +static void +metaslab_passivate_allocator(metaslab_group_t *mg, metaslab_t *msp, + uint64_t weight) +{ + ASSERT(MUTEX_HELD(&msp->ms_lock)); + if (msp->ms_weight & METASLAB_WEIGHT_CLAIM) { + metaslab_group_sort(mg, msp, weight); + return; + } + + mutex_enter(&mg->mg_lock); + ASSERT3P(msp->ms_group, ==, mg); + if (msp->ms_primary) { + ASSERT3U(0, <=, msp->ms_allocator); + ASSERT3U(msp->ms_allocator, <, mg->mg_allocators); + ASSERT3P(mg->mg_primaries[msp->ms_allocator], ==, msp); + ASSERT(msp->ms_weight & METASLAB_WEIGHT_PRIMARY); + mg->mg_primaries[msp->ms_allocator] = NULL; + } else { + ASSERT(msp->ms_weight & METASLAB_WEIGHT_SECONDARY); + ASSERT3P(mg->mg_secondaries[msp->ms_allocator], ==, msp); + mg->mg_secondaries[msp->ms_allocator] = NULL; + } + msp->ms_allocator = -1; + metaslab_group_sort_impl(mg, msp, weight); + mutex_exit(&mg->mg_lock); +} + +static void +metaslab_passivate(metaslab_t *msp, uint64_t weight) +{ + uint64_t size = weight & ~METASLAB_WEIGHT_TYPE; + + /* + * If size < SPA_MINBLOCKSIZE, then we will not allocate from + * this metaslab again. In that case, it had better be empty, + * or we would be leaving space on the table. + */ + ASSERT(size >= SPA_MINBLOCKSIZE || + range_tree_is_empty(msp->ms_allocatable)); + ASSERT0(weight & METASLAB_ACTIVE_MASK); + + msp->ms_activation_weight = 0; + metaslab_passivate_allocator(msp->ms_group, msp, weight); + ASSERT((msp->ms_weight & METASLAB_ACTIVE_MASK) == 0); +} + +/* + * Segment-based metaslabs are activated once and remain active until + * we either fail an allocation attempt (similar to space-based metaslabs) + * or have exhausted the free space in zfs_metaslab_switch_threshold + * buckets since the metaslab was activated. This function checks to see + * if we've exhaused the zfs_metaslab_switch_threshold buckets in the + * metaslab and passivates it proactively. This will allow us to select a + * metaslabs with larger contiguous region if any remaining within this + * metaslab group. If we're in sync pass > 1, then we continue using this + * metaslab so that we don't dirty more block and cause more sync passes. + */ +void +metaslab_segment_may_passivate(metaslab_t *msp) +{ + spa_t *spa = msp->ms_group->mg_vd->vdev_spa; + + if (WEIGHT_IS_SPACEBASED(msp->ms_weight) || spa_sync_pass(spa) > 1) + return; + + /* + * Since we are in the middle of a sync pass, the most accurate + * information that is accessible to us is the in-core range tree + * histogram; calculate the new weight based on that information. + */ + uint64_t weight = metaslab_weight_from_range_tree(msp); + int activation_idx = WEIGHT_GET_INDEX(msp->ms_activation_weight); + int current_idx = WEIGHT_GET_INDEX(weight); + + if (current_idx <= activation_idx - zfs_metaslab_switch_threshold) + metaslab_passivate(msp, weight); +} + +static void +metaslab_preload(void *arg) +{ + metaslab_t *msp = arg; + spa_t *spa = msp->ms_group->mg_vd->vdev_spa; + + ASSERT(!MUTEX_HELD(&msp->ms_group->mg_lock)); + + mutex_enter(&msp->ms_lock); + metaslab_load_wait(msp); + if (!msp->ms_loaded) + (void) metaslab_load(msp); + msp->ms_selected_txg = spa_syncing_txg(spa); + mutex_exit(&msp->ms_lock); +} + +static void +metaslab_group_preload(metaslab_group_t *mg) +{ + spa_t *spa = mg->mg_vd->vdev_spa; + metaslab_t *msp; + avl_tree_t *t = &mg->mg_metaslab_tree; + int m = 0; + + if (spa_shutting_down(spa) || !metaslab_preload_enabled) { + taskq_wait(mg->mg_taskq); + return; + } + + mutex_enter(&mg->mg_lock); + + /* + * Load the next potential metaslabs + */ + for (msp = avl_first(t); msp != NULL; msp = AVL_NEXT(t, msp)) { + ASSERT3P(msp->ms_group, ==, mg); + + /* + * We preload only the maximum number of metaslabs specified + * by metaslab_preload_limit. If a metaslab is being forced + * to condense then we preload it too. This will ensure + * that force condensing happens in the next txg. + */ + if (++m > metaslab_preload_limit && !msp->ms_condense_wanted) { + continue; + } + + VERIFY(taskq_dispatch(mg->mg_taskq, metaslab_preload, + msp, TQ_SLEEP) != 0); + } + mutex_exit(&mg->mg_lock); +} + +/* + * Determine if the space map's on-disk footprint is past our tolerance + * for inefficiency. We would like to use the following criteria to make + * our decision: + * + * 1. The size of the space map object should not dramatically increase as a + * result of writing out the free space range tree. + * + * 2. The minimal on-disk space map representation is zfs_condense_pct/100 + * times the size than the free space range tree representation + * (i.e. zfs_condense_pct = 110 and in-core = 1MB, minimal = 1.1MB). + * + * 3. The on-disk size of the space map should actually decrease. + * + * Unfortunately, we cannot compute the on-disk size of the space map in this + * context because we cannot accurately compute the effects of compression, etc. + * Instead, we apply the heuristic described in the block comment for + * zfs_metaslab_condense_block_threshold - we only condense if the space used + * is greater than a threshold number of blocks. + */ +static boolean_t +metaslab_should_condense(metaslab_t *msp) +{ + space_map_t *sm = msp->ms_sm; + vdev_t *vd = msp->ms_group->mg_vd; + uint64_t vdev_blocksize = 1 << vd->vdev_ashift; + uint64_t current_txg = spa_syncing_txg(vd->vdev_spa); + + ASSERT(MUTEX_HELD(&msp->ms_lock)); + ASSERT(msp->ms_loaded); + + /* + * Allocations and frees in early passes are generally more space + * efficient (in terms of blocks described in space map entries) + * than the ones in later passes (e.g. we don't compress after + * sync pass 5) and condensing a metaslab multiple times in a txg + * could degrade performance. + * + * Thus we prefer condensing each metaslab at most once every txg at + * the earliest sync pass possible. If a metaslab is eligible for + * condensing again after being considered for condensing within the + * same txg, it will hopefully be dirty in the next txg where it will + * be condensed at an earlier pass. + */ + if (msp->ms_condense_checked_txg == current_txg) + return (B_FALSE); + msp->ms_condense_checked_txg = current_txg; + + /* + * We always condense metaslabs that are empty and metaslabs for + * which a condense request has been made. + */ + if (avl_is_empty(&msp->ms_allocatable_by_size) || + msp->ms_condense_wanted) + return (B_TRUE); + + uint64_t object_size = space_map_length(msp->ms_sm); + uint64_t optimal_size = space_map_estimate_optimal_size(sm, + msp->ms_allocatable, SM_NO_VDEVID); + + dmu_object_info_t doi; + dmu_object_info_from_db(sm->sm_dbuf, &doi); + uint64_t record_size = MAX(doi.doi_data_block_size, vdev_blocksize); + + return (object_size >= (optimal_size * zfs_condense_pct / 100) && + object_size > zfs_metaslab_condense_block_threshold * record_size); +} + +/* + * Condense the on-disk space map representation to its minimized form. + * The minimized form consists of a small number of allocations followed by + * the entries of the free range tree. + */ +static void +metaslab_condense(metaslab_t *msp, uint64_t txg, dmu_tx_t *tx) +{ + range_tree_t *condense_tree; + space_map_t *sm = msp->ms_sm; + + ASSERT(MUTEX_HELD(&msp->ms_lock)); + ASSERT(msp->ms_loaded); + + zfs_dbgmsg("condensing: txg %llu, msp[%llu] %p, vdev id %llu, " + "spa %s, smp size %llu, segments %lu, forcing condense=%s", txg, + msp->ms_id, msp, msp->ms_group->mg_vd->vdev_id, + msp->ms_group->mg_vd->vdev_spa->spa_name, + space_map_length(msp->ms_sm), + avl_numnodes(&msp->ms_allocatable->rt_root), + msp->ms_condense_wanted ? "TRUE" : "FALSE"); + + msp->ms_condense_wanted = B_FALSE; + + /* + * Create an range tree that is 100% allocated. We remove segments + * that have been freed in this txg, any deferred frees that exist, + * and any allocation in the future. Removing segments should be + * a relatively inexpensive operation since we expect these trees to + * have a small number of nodes. + */ + condense_tree = range_tree_create(NULL, NULL); + range_tree_add(condense_tree, msp->ms_start, msp->ms_size); + + range_tree_walk(msp->ms_freeing, range_tree_remove, condense_tree); + range_tree_walk(msp->ms_freed, range_tree_remove, condense_tree); + + for (int t = 0; t < TXG_DEFER_SIZE; t++) { + range_tree_walk(msp->ms_defer[t], + range_tree_remove, condense_tree); + } + + for (int t = 1; t < TXG_CONCURRENT_STATES; t++) { + range_tree_walk(msp->ms_allocating[(txg + t) & TXG_MASK], + range_tree_remove, condense_tree); + } + + /* + * We're about to drop the metaslab's lock thus allowing + * other consumers to change it's content. Set the + * metaslab's ms_condensing flag to ensure that + * allocations on this metaslab do not occur while we're + * in the middle of committing it to disk. This is only critical + * for ms_allocatable as all other range trees use per txg + * views of their content. + */ + msp->ms_condensing = B_TRUE; + + mutex_exit(&msp->ms_lock); + space_map_truncate(sm, zfs_metaslab_sm_blksz, tx); + + /* + * While we would ideally like to create a space map representation + * that consists only of allocation records, doing so can be + * prohibitively expensive because the in-core free tree can be + * large, and therefore computationally expensive to subtract + * from the condense_tree. Instead we sync out two trees, a cheap + * allocation only tree followed by the in-core free tree. While not + * optimal, this is typically close to optimal, and much cheaper to + * compute. + */ + space_map_write(sm, condense_tree, SM_ALLOC, SM_NO_VDEVID, tx); + range_tree_vacate(condense_tree, NULL, NULL); + range_tree_destroy(condense_tree); + + space_map_write(sm, msp->ms_allocatable, SM_FREE, SM_NO_VDEVID, tx); + mutex_enter(&msp->ms_lock); + msp->ms_condensing = B_FALSE; +} + +/* + * Write a metaslab to disk in the context of the specified transaction group. + */ +void +metaslab_sync(metaslab_t *msp, uint64_t txg) +{ + metaslab_group_t *mg = msp->ms_group; + vdev_t *vd = mg->mg_vd; + spa_t *spa = vd->vdev_spa; + objset_t *mos = spa_meta_objset(spa); + range_tree_t *alloctree = msp->ms_allocating[txg & TXG_MASK]; + dmu_tx_t *tx; + uint64_t object = space_map_object(msp->ms_sm); + + ASSERT(!vd->vdev_ishole); + + /* + * This metaslab has just been added so there's no work to do now. + */ + if (msp->ms_freeing == NULL) { + ASSERT3P(alloctree, ==, NULL); + return; + } + + ASSERT3P(alloctree, !=, NULL); + ASSERT3P(msp->ms_freeing, !=, NULL); + ASSERT3P(msp->ms_freed, !=, NULL); + ASSERT3P(msp->ms_checkpointing, !=, NULL); + + /* + * Normally, we don't want to process a metaslab if there are no + * allocations or frees to perform. However, if the metaslab is being + * forced to condense and it's loaded, we need to let it through. + */ + if (range_tree_is_empty(alloctree) && + range_tree_is_empty(msp->ms_freeing) && + range_tree_is_empty(msp->ms_checkpointing) && + !(msp->ms_loaded && msp->ms_condense_wanted)) + return; + + + VERIFY(txg <= spa_final_dirty_txg(spa)); + + /* + * The only state that can actually be changing concurrently with + * metaslab_sync() is the metaslab's ms_allocatable. No other + * thread can be modifying this txg's alloc, freeing, + * freed, or space_map_phys_t. We drop ms_lock whenever we + * could call into the DMU, because the DMU can call down to us + * (e.g. via zio_free()) at any time. + * + * The spa_vdev_remove_thread() can be reading metaslab state + * concurrently, and it is locked out by the ms_sync_lock. Note + * that the ms_lock is insufficient for this, because it is dropped + * by space_map_write(). + */ + tx = dmu_tx_create_assigned(spa_get_dsl(spa), txg); + + if (msp->ms_sm == NULL) { + uint64_t new_object; + + new_object = space_map_alloc(mos, zfs_metaslab_sm_blksz, tx); + VERIFY3U(new_object, !=, 0); + + VERIFY0(space_map_open(&msp->ms_sm, mos, new_object, + msp->ms_start, msp->ms_size, vd->vdev_ashift)); + ASSERT(msp->ms_sm != NULL); + } + + if (!range_tree_is_empty(msp->ms_checkpointing) && + vd->vdev_checkpoint_sm == NULL) { + ASSERT(spa_has_checkpoint(spa)); + + uint64_t new_object = space_map_alloc(mos, + vdev_standard_sm_blksz, tx); + VERIFY3U(new_object, !=, 0); + + VERIFY0(space_map_open(&vd->vdev_checkpoint_sm, + mos, new_object, 0, vd->vdev_asize, vd->vdev_ashift)); + ASSERT3P(vd->vdev_checkpoint_sm, !=, NULL); + + /* + * We save the space map object as an entry in vdev_top_zap + * so it can be retrieved when the pool is reopened after an + * export or through zdb. + */ + VERIFY0(zap_add(vd->vdev_spa->spa_meta_objset, + vd->vdev_top_zap, VDEV_TOP_ZAP_POOL_CHECKPOINT_SM, + sizeof (new_object), 1, &new_object, tx)); + } + + mutex_enter(&msp->ms_sync_lock); + mutex_enter(&msp->ms_lock); + + /* + * Note: metaslab_condense() clears the space map's histogram. + * Therefore we must verify and remove this histogram before + * condensing. + */ + metaslab_group_histogram_verify(mg); + metaslab_class_histogram_verify(mg->mg_class); + metaslab_group_histogram_remove(mg, msp); + + if (msp->ms_loaded && metaslab_should_condense(msp)) { + metaslab_condense(msp, txg, tx); + } else { + mutex_exit(&msp->ms_lock); + space_map_write(msp->ms_sm, alloctree, SM_ALLOC, + SM_NO_VDEVID, tx); + space_map_write(msp->ms_sm, msp->ms_freeing, SM_FREE, + SM_NO_VDEVID, tx); + mutex_enter(&msp->ms_lock); + } + + if (!range_tree_is_empty(msp->ms_checkpointing)) { + ASSERT(spa_has_checkpoint(spa)); + ASSERT3P(vd->vdev_checkpoint_sm, !=, NULL); + + /* + * Since we are doing writes to disk and the ms_checkpointing + * tree won't be changing during that time, we drop the + * ms_lock while writing to the checkpoint space map. + */ + mutex_exit(&msp->ms_lock); + space_map_write(vd->vdev_checkpoint_sm, + msp->ms_checkpointing, SM_FREE, SM_NO_VDEVID, tx); + mutex_enter(&msp->ms_lock); + space_map_update(vd->vdev_checkpoint_sm); + + spa->spa_checkpoint_info.sci_dspace += + range_tree_space(msp->ms_checkpointing); + vd->vdev_stat.vs_checkpoint_space += + range_tree_space(msp->ms_checkpointing); + ASSERT3U(vd->vdev_stat.vs_checkpoint_space, ==, + -vd->vdev_checkpoint_sm->sm_alloc); + + range_tree_vacate(msp->ms_checkpointing, NULL, NULL); + } + + if (msp->ms_loaded) { + /* + * When the space map is loaded, we have an accurate + * histogram in the range tree. This gives us an opportunity + * to bring the space map's histogram up-to-date so we clear + * it first before updating it. + */ + space_map_histogram_clear(msp->ms_sm); + space_map_histogram_add(msp->ms_sm, msp->ms_allocatable, tx); + + /* + * Since we've cleared the histogram we need to add back + * any free space that has already been processed, plus + * any deferred space. This allows the on-disk histogram + * to accurately reflect all free space even if some space + * is not yet available for allocation (i.e. deferred). + */ + space_map_histogram_add(msp->ms_sm, msp->ms_freed, tx); + + /* + * Add back any deferred free space that has not been + * added back into the in-core free tree yet. This will + * ensure that we don't end up with a space map histogram + * that is completely empty unless the metaslab is fully + * allocated. + */ + for (int t = 0; t < TXG_DEFER_SIZE; t++) { + space_map_histogram_add(msp->ms_sm, + msp->ms_defer[t], tx); + } + } + + /* + * Always add the free space from this sync pass to the space + * map histogram. We want to make sure that the on-disk histogram + * accounts for all free space. If the space map is not loaded, + * then we will lose some accuracy but will correct it the next + * time we load the space map. + */ + space_map_histogram_add(msp->ms_sm, msp->ms_freeing, tx); + + metaslab_group_histogram_add(mg, msp); + metaslab_group_histogram_verify(mg); + metaslab_class_histogram_verify(mg->mg_class); + + /* + * For sync pass 1, we avoid traversing this txg's free range tree + * and instead will just swap the pointers for freeing and + * freed. We can safely do this since the freed_tree is + * guaranteed to be empty on the initial pass. + */ + if (spa_sync_pass(spa) == 1) { + range_tree_swap(&msp->ms_freeing, &msp->ms_freed); + } else { + range_tree_vacate(msp->ms_freeing, + range_tree_add, msp->ms_freed); + } + range_tree_vacate(alloctree, NULL, NULL); + + ASSERT0(range_tree_space(msp->ms_allocating[txg & TXG_MASK])); + ASSERT0(range_tree_space(msp->ms_allocating[TXG_CLEAN(txg) + & TXG_MASK])); + ASSERT0(range_tree_space(msp->ms_freeing)); + ASSERT0(range_tree_space(msp->ms_checkpointing)); + + mutex_exit(&msp->ms_lock); + + if (object != space_map_object(msp->ms_sm)) { + object = space_map_object(msp->ms_sm); + dmu_write(mos, vd->vdev_ms_array, sizeof (uint64_t) * + msp->ms_id, sizeof (uint64_t), &object, tx); + } + mutex_exit(&msp->ms_sync_lock); + dmu_tx_commit(tx); +} + +/* + * Called after a transaction group has completely synced to mark + * all of the metaslab's free space as usable. + */ +void +metaslab_sync_done(metaslab_t *msp, uint64_t txg) +{ + metaslab_group_t *mg = msp->ms_group; + vdev_t *vd = mg->mg_vd; + spa_t *spa = vd->vdev_spa; + range_tree_t **defer_tree; + int64_t alloc_delta, defer_delta; + boolean_t defer_allowed = B_TRUE; + + ASSERT(!vd->vdev_ishole); + + mutex_enter(&msp->ms_lock); + + /* + * If this metaslab is just becoming available, initialize its + * range trees and add its capacity to the vdev. + */ + if (msp->ms_freed == NULL) { + for (int t = 0; t < TXG_SIZE; t++) { + ASSERT(msp->ms_allocating[t] == NULL); + + msp->ms_allocating[t] = range_tree_create(NULL, NULL); + } + + ASSERT3P(msp->ms_freeing, ==, NULL); + msp->ms_freeing = range_tree_create(NULL, NULL); + + ASSERT3P(msp->ms_freed, ==, NULL); + msp->ms_freed = range_tree_create(NULL, NULL); + + for (int t = 0; t < TXG_DEFER_SIZE; t++) { + ASSERT(msp->ms_defer[t] == NULL); + + msp->ms_defer[t] = range_tree_create(NULL, NULL); + } + + ASSERT3P(msp->ms_checkpointing, ==, NULL); + msp->ms_checkpointing = range_tree_create(NULL, NULL); + + vdev_space_update(vd, 0, 0, msp->ms_size); + } + ASSERT0(range_tree_space(msp->ms_freeing)); + ASSERT0(range_tree_space(msp->ms_checkpointing)); + + defer_tree = &msp->ms_defer[txg % TXG_DEFER_SIZE]; + + uint64_t free_space = metaslab_class_get_space(spa_normal_class(spa)) - + metaslab_class_get_alloc(spa_normal_class(spa)); + if (free_space <= spa_get_slop_space(spa) || vd->vdev_removing) { + defer_allowed = B_FALSE; + } + + defer_delta = 0; + alloc_delta = space_map_alloc_delta(msp->ms_sm); + if (defer_allowed) { + defer_delta = range_tree_space(msp->ms_freed) - + range_tree_space(*defer_tree); + } else { + defer_delta -= range_tree_space(*defer_tree); + } + + vdev_space_update(vd, alloc_delta + defer_delta, defer_delta, 0); + + /* + * If there's a metaslab_load() in progress, wait for it to complete + * so that we have a consistent view of the in-core space map. + */ + metaslab_load_wait(msp); + + /* + * Move the frees from the defer_tree back to the free + * range tree (if it's loaded). Swap the freed_tree and + * the defer_tree -- this is safe to do because we've + * just emptied out the defer_tree. + */ + range_tree_vacate(*defer_tree, + msp->ms_loaded ? range_tree_add : NULL, msp->ms_allocatable); + if (defer_allowed) { + range_tree_swap(&msp->ms_freed, defer_tree); + } else { + range_tree_vacate(msp->ms_freed, + msp->ms_loaded ? range_tree_add : NULL, + msp->ms_allocatable); + } + space_map_update(msp->ms_sm); + + msp->ms_deferspace += defer_delta; + ASSERT3S(msp->ms_deferspace, >=, 0); + ASSERT3S(msp->ms_deferspace, <=, msp->ms_size); + if (msp->ms_deferspace != 0) { + /* + * Keep syncing this metaslab until all deferred frees + * are back in circulation. + */ + vdev_dirty(vd, VDD_METASLAB, msp, txg + 1); + } + + if (msp->ms_new) { + msp->ms_new = B_FALSE; + mutex_enter(&mg->mg_lock); + mg->mg_ms_ready++; + mutex_exit(&mg->mg_lock); + } + /* + * Calculate the new weights before unloading any metaslabs. + * This will give us the most accurate weighting. + */ + metaslab_group_sort(mg, msp, metaslab_weight(msp) | + (msp->ms_weight & METASLAB_ACTIVE_MASK)); + + /* + * If the metaslab is loaded and we've not tried to load or allocate + * from it in 'metaslab_unload_delay' txgs, then unload it. + */ + if (msp->ms_loaded && + msp->ms_initializing == 0 && + msp->ms_selected_txg + metaslab_unload_delay < txg) { + for (int t = 1; t < TXG_CONCURRENT_STATES; t++) { + VERIFY0(range_tree_space( + msp->ms_allocating[(txg + t) & TXG_MASK])); + } + if (msp->ms_allocator != -1) { + metaslab_passivate(msp, msp->ms_weight & + ~METASLAB_ACTIVE_MASK); + } + + if (!metaslab_debug_unload) + metaslab_unload(msp); + } + + ASSERT0(range_tree_space(msp->ms_allocating[txg & TXG_MASK])); + ASSERT0(range_tree_space(msp->ms_freeing)); + ASSERT0(range_tree_space(msp->ms_freed)); + ASSERT0(range_tree_space(msp->ms_checkpointing)); + + mutex_exit(&msp->ms_lock); +} + +void +metaslab_sync_reassess(metaslab_group_t *mg) +{ + spa_t *spa = mg->mg_class->mc_spa; + + spa_config_enter(spa, SCL_ALLOC, FTAG, RW_READER); + metaslab_group_alloc_update(mg); + mg->mg_fragmentation = metaslab_group_fragmentation(mg); + + /* + * Preload the next potential metaslabs but only on active + * metaslab groups. We can get into a state where the metaslab + * is no longer active since we dirty metaslabs as we remove a + * a device, thus potentially making the metaslab group eligible + * for preloading. + */ + if (mg->mg_activation_count > 0) { + metaslab_group_preload(mg); + } + spa_config_exit(spa, SCL_ALLOC, FTAG); +} + +static uint64_t +metaslab_distance(metaslab_t *msp, dva_t *dva) +{ + uint64_t ms_shift = msp->ms_group->mg_vd->vdev_ms_shift; + uint64_t offset = DVA_GET_OFFSET(dva) >> ms_shift; + uint64_t start = msp->ms_id; + + if (msp->ms_group->mg_vd->vdev_id != DVA_GET_VDEV(dva)) + return (1ULL << 63); + + if (offset < start) + return ((start - offset) << ms_shift); + if (offset > start) + return ((offset - start) << ms_shift); + return (0); +} + +/* + * ========================================================================== + * Metaslab allocation tracing facility + * ========================================================================== + */ +kstat_t *metaslab_trace_ksp; +kstat_named_t metaslab_trace_over_limit; + +void +metaslab_alloc_trace_init(void) +{ + ASSERT(metaslab_alloc_trace_cache == NULL); + metaslab_alloc_trace_cache = kmem_cache_create( + "metaslab_alloc_trace_cache", sizeof (metaslab_alloc_trace_t), + 0, NULL, NULL, NULL, NULL, NULL, 0); + metaslab_trace_ksp = kstat_create("zfs", 0, "metaslab_trace_stats", + "misc", KSTAT_TYPE_NAMED, 1, KSTAT_FLAG_VIRTUAL); + if (metaslab_trace_ksp != NULL) { + metaslab_trace_ksp->ks_data = &metaslab_trace_over_limit; + kstat_named_init(&metaslab_trace_over_limit, + "metaslab_trace_over_limit", KSTAT_DATA_UINT64); + kstat_install(metaslab_trace_ksp); + } +} + +void +metaslab_alloc_trace_fini(void) +{ + if (metaslab_trace_ksp != NULL) { + kstat_delete(metaslab_trace_ksp); + metaslab_trace_ksp = NULL; + } + kmem_cache_destroy(metaslab_alloc_trace_cache); + metaslab_alloc_trace_cache = NULL; +} + +/* + * Add an allocation trace element to the allocation tracing list. + */ +static void +metaslab_trace_add(zio_alloc_list_t *zal, metaslab_group_t *mg, + metaslab_t *msp, uint64_t psize, uint32_t dva_id, uint64_t offset, + int allocator) +{ + if (!metaslab_trace_enabled) + return; + + /* + * When the tracing list reaches its maximum we remove + * the second element in the list before adding a new one. + * By removing the second element we preserve the original + * entry as a clue to what allocations steps have already been + * performed. + */ + if (zal->zal_size == metaslab_trace_max_entries) { + metaslab_alloc_trace_t *mat_next; +#ifdef DEBUG + panic("too many entries in allocation list"); +#endif + atomic_inc_64(&metaslab_trace_over_limit.value.ui64); + zal->zal_size--; + mat_next = list_next(&zal->zal_list, list_head(&zal->zal_list)); + list_remove(&zal->zal_list, mat_next); + kmem_cache_free(metaslab_alloc_trace_cache, mat_next); + } + + metaslab_alloc_trace_t *mat = + kmem_cache_alloc(metaslab_alloc_trace_cache, KM_SLEEP); + list_link_init(&mat->mat_list_node); + mat->mat_mg = mg; + mat->mat_msp = msp; + mat->mat_size = psize; + mat->mat_dva_id = dva_id; + mat->mat_offset = offset; + mat->mat_weight = 0; + mat->mat_allocator = allocator; + + if (msp != NULL) + mat->mat_weight = msp->ms_weight; + + /* + * The list is part of the zio so locking is not required. Only + * a single thread will perform allocations for a given zio. + */ + list_insert_tail(&zal->zal_list, mat); + zal->zal_size++; + + ASSERT3U(zal->zal_size, <=, metaslab_trace_max_entries); +} + +void +metaslab_trace_init(zio_alloc_list_t *zal) +{ + list_create(&zal->zal_list, sizeof (metaslab_alloc_trace_t), + offsetof(metaslab_alloc_trace_t, mat_list_node)); + zal->zal_size = 0; +} + +void +metaslab_trace_fini(zio_alloc_list_t *zal) +{ + metaslab_alloc_trace_t *mat; + + while ((mat = list_remove_head(&zal->zal_list)) != NULL) + kmem_cache_free(metaslab_alloc_trace_cache, mat); + list_destroy(&zal->zal_list); + zal->zal_size = 0; +} + +/* + * ========================================================================== + * Metaslab block operations + * ========================================================================== + */ + +static void +metaslab_group_alloc_increment(spa_t *spa, uint64_t vdev, void *tag, int flags, + int allocator) +{ + if (!(flags & METASLAB_ASYNC_ALLOC) || + (flags & METASLAB_DONT_THROTTLE)) + return; + + metaslab_group_t *mg = vdev_lookup_top(spa, vdev)->vdev_mg; + if (!mg->mg_class->mc_alloc_throttle_enabled) + return; + + (void) refcount_add(&mg->mg_alloc_queue_depth[allocator], tag); +} + +static void +metaslab_group_increment_qdepth(metaslab_group_t *mg, int allocator) +{ + uint64_t max = mg->mg_max_alloc_queue_depth; + uint64_t cur = mg->mg_cur_max_alloc_queue_depth[allocator]; + while (cur < max) { + if (atomic_cas_64(&mg->mg_cur_max_alloc_queue_depth[allocator], + cur, cur + 1) == cur) { + atomic_inc_64( + &mg->mg_class->mc_alloc_max_slots[allocator]); + return; + } + cur = mg->mg_cur_max_alloc_queue_depth[allocator]; + } +} + +void +metaslab_group_alloc_decrement(spa_t *spa, uint64_t vdev, void *tag, int flags, + int allocator, boolean_t io_complete) +{ + if (!(flags & METASLAB_ASYNC_ALLOC) || + (flags & METASLAB_DONT_THROTTLE)) + return; + + metaslab_group_t *mg = vdev_lookup_top(spa, vdev)->vdev_mg; + if (!mg->mg_class->mc_alloc_throttle_enabled) + return; + + (void) refcount_remove(&mg->mg_alloc_queue_depth[allocator], tag); + if (io_complete) + metaslab_group_increment_qdepth(mg, allocator); +} + +void +metaslab_group_alloc_verify(spa_t *spa, const blkptr_t *bp, void *tag, + int allocator) +{ +#ifdef ZFS_DEBUG + const dva_t *dva = bp->blk_dva; + int ndvas = BP_GET_NDVAS(bp); + + for (int d = 0; d < ndvas; d++) { + uint64_t vdev = DVA_GET_VDEV(&dva[d]); + metaslab_group_t *mg = vdev_lookup_top(spa, vdev)->vdev_mg; + VERIFY(refcount_not_held(&mg->mg_alloc_queue_depth[allocator], + tag)); + } +#endif +} + +static uint64_t +metaslab_block_alloc(metaslab_t *msp, uint64_t size, uint64_t txg) +{ + uint64_t start; + range_tree_t *rt = msp->ms_allocatable; + metaslab_class_t *mc = msp->ms_group->mg_class; + + VERIFY(!msp->ms_condensing); + VERIFY0(msp->ms_initializing); + + start = mc->mc_ops->msop_alloc(msp, size); + if (start != -1ULL) { + metaslab_group_t *mg = msp->ms_group; + vdev_t *vd = mg->mg_vd; + + VERIFY0(P2PHASE(start, 1ULL << vd->vdev_ashift)); + VERIFY0(P2PHASE(size, 1ULL << vd->vdev_ashift)); + VERIFY3U(range_tree_space(rt) - size, <=, msp->ms_size); + range_tree_remove(rt, start, size); + + if (range_tree_is_empty(msp->ms_allocating[txg & TXG_MASK])) + vdev_dirty(mg->mg_vd, VDD_METASLAB, msp, txg); + + range_tree_add(msp->ms_allocating[txg & TXG_MASK], start, size); + + /* Track the last successful allocation */ + msp->ms_alloc_txg = txg; + metaslab_verify_space(msp, txg); + } + + /* + * Now that we've attempted the allocation we need to update the + * metaslab's maximum block size since it may have changed. + */ + msp->ms_max_size = metaslab_block_maxsize(msp); + return (start); +} + +/* + * Find the metaslab with the highest weight that is less than what we've + * already tried. In the common case, this means that we will examine each + * metaslab at most once. Note that concurrent callers could reorder metaslabs + * by activation/passivation once we have dropped the mg_lock. If a metaslab is + * activated by another thread, and we fail to allocate from the metaslab we + * have selected, we may not try the newly-activated metaslab, and instead + * activate another metaslab. This is not optimal, but generally does not cause + * any problems (a possible exception being if every metaslab is completely full + * except for the the newly-activated metaslab which we fail to examine). + */ +static metaslab_t * +find_valid_metaslab(metaslab_group_t *mg, uint64_t activation_weight, + dva_t *dva, int d, uint64_t min_distance, uint64_t asize, int allocator, + zio_alloc_list_t *zal, metaslab_t *search, boolean_t *was_active) +{ + avl_index_t idx; + avl_tree_t *t = &mg->mg_metaslab_tree; + metaslab_t *msp = avl_find(t, search, &idx); + if (msp == NULL) + msp = avl_nearest(t, idx, AVL_AFTER); + + for (; msp != NULL; msp = AVL_NEXT(t, msp)) { + int i; + if (!metaslab_should_allocate(msp, asize)) { + metaslab_trace_add(zal, mg, msp, asize, d, + TRACE_TOO_SMALL, allocator); + continue; + } + + /* + * If the selected metaslab is condensing or being + * initialized, skip it. + */ + if (msp->ms_condensing || msp->ms_initializing > 0) + continue; + + *was_active = msp->ms_allocator != -1; + /* + * If we're activating as primary, this is our first allocation + * from this disk, so we don't need to check how close we are. + * If the metaslab under consideration was already active, + * we're getting desperate enough to steal another allocator's + * metaslab, so we still don't care about distances. + */ + if (activation_weight == METASLAB_WEIGHT_PRIMARY || *was_active) + break; + + uint64_t target_distance = min_distance + + (space_map_allocated(msp->ms_sm) != 0 ? 0 : + min_distance >> 1); + + for (i = 0; i < d; i++) { + if (metaslab_distance(msp, &dva[i]) < target_distance) + break; + } + if (i == d) + break; + } + + if (msp != NULL) { + search->ms_weight = msp->ms_weight; + search->ms_start = msp->ms_start + 1; + search->ms_allocator = msp->ms_allocator; + search->ms_primary = msp->ms_primary; + } + return (msp); +} + +/* ARGSUSED */ +static uint64_t +metaslab_group_alloc_normal(metaslab_group_t *mg, zio_alloc_list_t *zal, + uint64_t asize, uint64_t txg, uint64_t min_distance, dva_t *dva, int d, + int allocator) +{ + metaslab_t *msp = NULL; + uint64_t offset = -1ULL; + uint64_t activation_weight; + + activation_weight = METASLAB_WEIGHT_PRIMARY; + for (int i = 0; i < d; i++) { + if (activation_weight == METASLAB_WEIGHT_PRIMARY && + DVA_GET_VDEV(&dva[i]) == mg->mg_vd->vdev_id) { + activation_weight = METASLAB_WEIGHT_SECONDARY; + } else if (activation_weight == METASLAB_WEIGHT_SECONDARY && + DVA_GET_VDEV(&dva[i]) == mg->mg_vd->vdev_id) { + activation_weight = METASLAB_WEIGHT_CLAIM; + break; + } + } + + /* + * If we don't have enough metaslabs active to fill the entire array, we + * just use the 0th slot. + */ + if (mg->mg_ms_ready < mg->mg_allocators * 3) + allocator = 0; + + ASSERT3U(mg->mg_vd->vdev_ms_count, >=, 2); + + metaslab_t *search = kmem_alloc(sizeof (*search), KM_SLEEP); + search->ms_weight = UINT64_MAX; + search->ms_start = 0; + /* + * At the end of the metaslab tree are the already-active metaslabs, + * first the primaries, then the secondaries. When we resume searching + * through the tree, we need to consider ms_allocator and ms_primary so + * we start in the location right after where we left off, and don't + * accidentally loop forever considering the same metaslabs. + */ + search->ms_allocator = -1; + search->ms_primary = B_TRUE; + for (;;) { + boolean_t was_active = B_FALSE; + + mutex_enter(&mg->mg_lock); + + if (activation_weight == METASLAB_WEIGHT_PRIMARY && + mg->mg_primaries[allocator] != NULL) { + msp = mg->mg_primaries[allocator]; + was_active = B_TRUE; + } else if (activation_weight == METASLAB_WEIGHT_SECONDARY && + mg->mg_secondaries[allocator] != NULL) { + msp = mg->mg_secondaries[allocator]; + was_active = B_TRUE; + } else { + msp = find_valid_metaslab(mg, activation_weight, dva, d, + min_distance, asize, allocator, zal, search, + &was_active); + } + + mutex_exit(&mg->mg_lock); + if (msp == NULL) { + kmem_free(search, sizeof (*search)); + return (-1ULL); + } + + mutex_enter(&msp->ms_lock); + /* + * Ensure that the metaslab we have selected is still + * capable of handling our request. It's possible that + * another thread may have changed the weight while we + * were blocked on the metaslab lock. We check the + * active status first to see if we need to reselect + * a new metaslab. + */ + if (was_active && !(msp->ms_weight & METASLAB_ACTIVE_MASK)) { + mutex_exit(&msp->ms_lock); + continue; + } + + /* + * If the metaslab is freshly activated for an allocator that + * isn't the one we're allocating from, or if it's a primary and + * we're seeking a secondary (or vice versa), we go back and + * select a new metaslab. + */ + if (!was_active && (msp->ms_weight & METASLAB_ACTIVE_MASK) && + (msp->ms_allocator != -1) && + (msp->ms_allocator != allocator || ((activation_weight == + METASLAB_WEIGHT_PRIMARY) != msp->ms_primary))) { + mutex_exit(&msp->ms_lock); + continue; + } + + if (msp->ms_weight & METASLAB_WEIGHT_CLAIM && + activation_weight != METASLAB_WEIGHT_CLAIM) { + metaslab_passivate(msp, msp->ms_weight & + ~METASLAB_WEIGHT_CLAIM); + mutex_exit(&msp->ms_lock); + continue; + } + + if (metaslab_activate(msp, allocator, activation_weight) != 0) { + mutex_exit(&msp->ms_lock); + continue; + } + + msp->ms_selected_txg = txg; + + /* + * Now that we have the lock, recheck to see if we should + * continue to use this metaslab for this allocation. The + * the metaslab is now loaded so metaslab_should_allocate() can + * accurately determine if the allocation attempt should + * proceed. + */ + if (!metaslab_should_allocate(msp, asize)) { + /* Passivate this metaslab and select a new one. */ + metaslab_trace_add(zal, mg, msp, asize, d, + TRACE_TOO_SMALL, allocator); + goto next; + } + + /* + * If this metaslab is currently condensing then pick again as + * we can't manipulate this metaslab until it's committed + * to disk. If this metaslab is being initialized, we shouldn't + * allocate from it since the allocated region might be + * overwritten after allocation. + */ + if (msp->ms_condensing) { + metaslab_trace_add(zal, mg, msp, asize, d, + TRACE_CONDENSING, allocator); + metaslab_passivate(msp, msp->ms_weight & + ~METASLAB_ACTIVE_MASK); + mutex_exit(&msp->ms_lock); + continue; + } else if (msp->ms_initializing > 0) { + metaslab_trace_add(zal, mg, msp, asize, d, + TRACE_INITIALIZING, allocator); + metaslab_passivate(msp, msp->ms_weight & + ~METASLAB_ACTIVE_MASK); + mutex_exit(&msp->ms_lock); + continue; + } + + offset = metaslab_block_alloc(msp, asize, txg); + metaslab_trace_add(zal, mg, msp, asize, d, offset, allocator); + + if (offset != -1ULL) { + /* Proactively passivate the metaslab, if needed */ + metaslab_segment_may_passivate(msp); + break; + } +next: + ASSERT(msp->ms_loaded); + + /* + * We were unable to allocate from this metaslab so determine + * a new weight for this metaslab. Now that we have loaded + * the metaslab we can provide a better hint to the metaslab + * selector. + * + * For space-based metaslabs, we use the maximum block size. + * This information is only available when the metaslab + * is loaded and is more accurate than the generic free + * space weight that was calculated by metaslab_weight(). + * This information allows us to quickly compare the maximum + * available allocation in the metaslab to the allocation + * size being requested. + * + * For segment-based metaslabs, determine the new weight + * based on the highest bucket in the range tree. We + * explicitly use the loaded segment weight (i.e. the range + * tree histogram) since it contains the space that is + * currently available for allocation and is accurate + * even within a sync pass. + */ + if (WEIGHT_IS_SPACEBASED(msp->ms_weight)) { + uint64_t weight = metaslab_block_maxsize(msp); + WEIGHT_SET_SPACEBASED(weight); + metaslab_passivate(msp, weight); + } else { + metaslab_passivate(msp, + metaslab_weight_from_range_tree(msp)); + } + + /* + * We have just failed an allocation attempt, check + * that metaslab_should_allocate() agrees. Otherwise, + * we may end up in an infinite loop retrying the same + * metaslab. + */ + ASSERT(!metaslab_should_allocate(msp, asize)); + mutex_exit(&msp->ms_lock); + } + mutex_exit(&msp->ms_lock); + kmem_free(search, sizeof (*search)); + return (offset); +} + +static uint64_t +metaslab_group_alloc(metaslab_group_t *mg, zio_alloc_list_t *zal, + uint64_t asize, uint64_t txg, uint64_t min_distance, dva_t *dva, int d, + int allocator) +{ + uint64_t offset; + ASSERT(mg->mg_initialized); + + offset = metaslab_group_alloc_normal(mg, zal, asize, txg, + min_distance, dva, d, allocator); + + mutex_enter(&mg->mg_lock); + if (offset == -1ULL) { + mg->mg_failed_allocations++; + metaslab_trace_add(zal, mg, NULL, asize, d, + TRACE_GROUP_FAILURE, allocator); + if (asize == SPA_GANGBLOCKSIZE) { + /* + * This metaslab group was unable to allocate + * the minimum gang block size so it must be out of + * space. We must notify the allocation throttle + * to start skipping allocation attempts to this + * metaslab group until more space becomes available. + * Note: this failure cannot be caused by the + * allocation throttle since the allocation throttle + * is only responsible for skipping devices and + * not failing block allocations. + */ + mg->mg_no_free_space = B_TRUE; + } + } + mg->mg_allocations++; + mutex_exit(&mg->mg_lock); + return (offset); +} + +/* + * If we have to write a ditto block (i.e. more than one DVA for a given BP) + * on the same vdev as an existing DVA of this BP, then try to allocate it + * at least (vdev_asize / (2 ^ ditto_same_vdev_distance_shift)) away from the + * existing DVAs. + */ +int ditto_same_vdev_distance_shift = 3; + +/* + * Allocate a block for the specified i/o. + */ +int +metaslab_alloc_dva(spa_t *spa, metaslab_class_t *mc, uint64_t psize, + dva_t *dva, int d, dva_t *hintdva, uint64_t txg, int flags, + zio_alloc_list_t *zal, int allocator) +{ + metaslab_group_t *mg, *rotor; + vdev_t *vd; + boolean_t try_hard = B_FALSE; + + ASSERT(!DVA_IS_VALID(&dva[d])); + + /* + * For testing, make some blocks above a certain size be gang blocks. + */ + if (psize >= metaslab_force_ganging && (ddi_get_lbolt() & 3) == 0) { + metaslab_trace_add(zal, NULL, NULL, psize, d, TRACE_FORCE_GANG, + allocator); + return (SET_ERROR(ENOSPC)); + } + + /* + * Start at the rotor and loop through all mgs until we find something. + * Note that there's no locking on mc_rotor or mc_aliquot because + * nothing actually breaks if we miss a few updates -- we just won't + * allocate quite as evenly. It all balances out over time. + * + * If we are doing ditto or log blocks, try to spread them across + * consecutive vdevs. If we're forced to reuse a vdev before we've + * allocated all of our ditto blocks, then try and spread them out on + * that vdev as much as possible. If it turns out to not be possible, + * gradually lower our standards until anything becomes acceptable. + * Also, allocating on consecutive vdevs (as opposed to random vdevs) + * gives us hope of containing our fault domains to something we're + * able to reason about. Otherwise, any two top-level vdev failures + * will guarantee the loss of data. With consecutive allocation, + * only two adjacent top-level vdev failures will result in data loss. + * + * If we are doing gang blocks (hintdva is non-NULL), try to keep + * ourselves on the same vdev as our gang block header. That + * way, we can hope for locality in vdev_cache, plus it makes our + * fault domains something tractable. + */ + if (hintdva) { + vd = vdev_lookup_top(spa, DVA_GET_VDEV(&hintdva[d])); + + /* + * It's possible the vdev we're using as the hint no + * longer exists or its mg has been closed (e.g. by + * device removal). Consult the rotor when + * all else fails. + */ + if (vd != NULL && vd->vdev_mg != NULL) { + mg = vd->vdev_mg; + + if (flags & METASLAB_HINTBP_AVOID && + mg->mg_next != NULL) + mg = mg->mg_next; + } else { + mg = mc->mc_rotor; + } + } else if (d != 0) { + vd = vdev_lookup_top(spa, DVA_GET_VDEV(&dva[d - 1])); + mg = vd->vdev_mg->mg_next; + } else { + mg = mc->mc_rotor; + } + + /* + * If the hint put us into the wrong metaslab class, or into a + * metaslab group that has been passivated, just follow the rotor. + */ + if (mg->mg_class != mc || mg->mg_activation_count <= 0) + mg = mc->mc_rotor; + + rotor = mg; +top: + do { + boolean_t allocatable; + + ASSERT(mg->mg_activation_count == 1); + vd = mg->mg_vd; + + /* + * Don't allocate from faulted devices. + */ + if (try_hard) { + spa_config_enter(spa, SCL_ZIO, FTAG, RW_READER); + allocatable = vdev_allocatable(vd); + spa_config_exit(spa, SCL_ZIO, FTAG); + } else { + allocatable = vdev_allocatable(vd); + } + + /* + * Determine if the selected metaslab group is eligible + * for allocations. If we're ganging then don't allow + * this metaslab group to skip allocations since that would + * inadvertently return ENOSPC and suspend the pool + * even though space is still available. + */ + if (allocatable && !GANG_ALLOCATION(flags) && !try_hard) { + allocatable = metaslab_group_allocatable(mg, rotor, + psize, allocator, d); + } + + if (!allocatable) { + metaslab_trace_add(zal, mg, NULL, psize, d, + TRACE_NOT_ALLOCATABLE, allocator); + goto next; + } + + ASSERT(mg->mg_initialized); + + /* + * Avoid writing single-copy data to a failing, + * non-redundant vdev, unless we've already tried all + * other vdevs. + */ + if ((vd->vdev_stat.vs_write_errors > 0 || + vd->vdev_state < VDEV_STATE_HEALTHY) && + d == 0 && !try_hard && vd->vdev_children == 0) { + metaslab_trace_add(zal, mg, NULL, psize, d, + TRACE_VDEV_ERROR, allocator); + goto next; + } + + ASSERT(mg->mg_class == mc); + + /* + * If we don't need to try hard, then require that the + * block be 1/8th of the device away from any other DVAs + * in this BP. If we are trying hard, allow any offset + * to be used (distance=0). + */ + uint64_t distance = 0; + if (!try_hard) { + distance = vd->vdev_asize >> + ditto_same_vdev_distance_shift; + if (distance <= (1ULL << vd->vdev_ms_shift)) + distance = 0; + } + + uint64_t asize = vdev_psize_to_asize(vd, psize); + ASSERT(P2PHASE(asize, 1ULL << vd->vdev_ashift) == 0); + + uint64_t offset = metaslab_group_alloc(mg, zal, asize, txg, + distance, dva, d, allocator); + + if (offset != -1ULL) { + /* + * If we've just selected this metaslab group, + * figure out whether the corresponding vdev is + * over- or under-used relative to the pool, + * and set an allocation bias to even it out. + */ + if (mc->mc_aliquot == 0 && metaslab_bias_enabled) { + vdev_stat_t *vs = &vd->vdev_stat; + int64_t vu, cu; + + vu = (vs->vs_alloc * 100) / (vs->vs_space + 1); + cu = (mc->mc_alloc * 100) / (mc->mc_space + 1); + + /* + * Calculate how much more or less we should + * try to allocate from this device during + * this iteration around the rotor. + * For example, if a device is 80% full + * and the pool is 20% full then we should + * reduce allocations by 60% on this device. + * + * mg_bias = (20 - 80) * 512K / 100 = -307K + * + * This reduces allocations by 307K for this + * iteration. + */ + mg->mg_bias = ((cu - vu) * + (int64_t)mg->mg_aliquot) / 100; + } else if (!metaslab_bias_enabled) { + mg->mg_bias = 0; + } + + if (atomic_add_64_nv(&mc->mc_aliquot, asize) >= + mg->mg_aliquot + mg->mg_bias) { + mc->mc_rotor = mg->mg_next; + mc->mc_aliquot = 0; + } + + DVA_SET_VDEV(&dva[d], vd->vdev_id); + DVA_SET_OFFSET(&dva[d], offset); + DVA_SET_GANG(&dva[d], !!(flags & METASLAB_GANG_HEADER)); + DVA_SET_ASIZE(&dva[d], asize); + + return (0); + } +next: + mc->mc_rotor = mg->mg_next; + mc->mc_aliquot = 0; + } while ((mg = mg->mg_next) != rotor); + + /* + * If we haven't tried hard, do so now. + */ + if (!try_hard) { + try_hard = B_TRUE; + goto top; + } + + bzero(&dva[d], sizeof (dva_t)); + + metaslab_trace_add(zal, rotor, NULL, psize, d, TRACE_ENOSPC, allocator); + return (SET_ERROR(ENOSPC)); +} + +void +metaslab_free_concrete(vdev_t *vd, uint64_t offset, uint64_t asize, + boolean_t checkpoint) +{ + metaslab_t *msp; + spa_t *spa = vd->vdev_spa; + + ASSERT(vdev_is_concrete(vd)); + ASSERT3U(spa_config_held(spa, SCL_ALL, RW_READER), !=, 0); + ASSERT3U(offset >> vd->vdev_ms_shift, <, vd->vdev_ms_count); + + msp = vd->vdev_ms[offset >> vd->vdev_ms_shift]; + + VERIFY(!msp->ms_condensing); + VERIFY3U(offset, >=, msp->ms_start); + VERIFY3U(offset + asize, <=, msp->ms_start + msp->ms_size); + VERIFY0(P2PHASE(offset, 1ULL << vd->vdev_ashift)); + VERIFY0(P2PHASE(asize, 1ULL << vd->vdev_ashift)); + + metaslab_check_free_impl(vd, offset, asize); + + mutex_enter(&msp->ms_lock); + if (range_tree_is_empty(msp->ms_freeing) && + range_tree_is_empty(msp->ms_checkpointing)) { + vdev_dirty(vd, VDD_METASLAB, msp, spa_syncing_txg(spa)); + } + + if (checkpoint) { + ASSERT(spa_has_checkpoint(spa)); + range_tree_add(msp->ms_checkpointing, offset, asize); + } else { + range_tree_add(msp->ms_freeing, offset, asize); + } + mutex_exit(&msp->ms_lock); +} + +/* ARGSUSED */ +void +metaslab_free_impl_cb(uint64_t inner_offset, vdev_t *vd, uint64_t offset, + uint64_t size, void *arg) +{ + boolean_t *checkpoint = arg; + + ASSERT3P(checkpoint, !=, NULL); + + if (vd->vdev_ops->vdev_op_remap != NULL) + vdev_indirect_mark_obsolete(vd, offset, size); + else + metaslab_free_impl(vd, offset, size, *checkpoint); +} + +static void +metaslab_free_impl(vdev_t *vd, uint64_t offset, uint64_t size, + boolean_t checkpoint) +{ + spa_t *spa = vd->vdev_spa; + + ASSERT3U(spa_config_held(spa, SCL_ALL, RW_READER), !=, 0); + + if (spa_syncing_txg(spa) > spa_freeze_txg(spa)) + return; + + if (spa->spa_vdev_removal != NULL && + spa->spa_vdev_removal->svr_vdev_id == vd->vdev_id && + vdev_is_concrete(vd)) { + /* + * Note: we check if the vdev is concrete because when + * we complete the removal, we first change the vdev to be + * an indirect vdev (in open context), and then (in syncing + * context) clear spa_vdev_removal. + */ + free_from_removing_vdev(vd, offset, size); + } else if (vd->vdev_ops->vdev_op_remap != NULL) { + vdev_indirect_mark_obsolete(vd, offset, size); + vd->vdev_ops->vdev_op_remap(vd, offset, size, + metaslab_free_impl_cb, &checkpoint); + } else { + metaslab_free_concrete(vd, offset, size, checkpoint); + } +} + +typedef struct remap_blkptr_cb_arg { + blkptr_t *rbca_bp; + spa_remap_cb_t rbca_cb; + vdev_t *rbca_remap_vd; + uint64_t rbca_remap_offset; + void *rbca_cb_arg; +} remap_blkptr_cb_arg_t; + +void +remap_blkptr_cb(uint64_t inner_offset, vdev_t *vd, uint64_t offset, + uint64_t size, void *arg) +{ + remap_blkptr_cb_arg_t *rbca = arg; + blkptr_t *bp = rbca->rbca_bp; + + /* We can not remap split blocks. */ + if (size != DVA_GET_ASIZE(&bp->blk_dva[0])) + return; + ASSERT0(inner_offset); + + if (rbca->rbca_cb != NULL) { + /* + * At this point we know that we are not handling split + * blocks and we invoke the callback on the previous + * vdev which must be indirect. + */ + ASSERT3P(rbca->rbca_remap_vd->vdev_ops, ==, &vdev_indirect_ops); + + rbca->rbca_cb(rbca->rbca_remap_vd->vdev_id, + rbca->rbca_remap_offset, size, rbca->rbca_cb_arg); + + /* set up remap_blkptr_cb_arg for the next call */ + rbca->rbca_remap_vd = vd; + rbca->rbca_remap_offset = offset; + } + + /* + * The phys birth time is that of dva[0]. This ensures that we know + * when each dva was written, so that resilver can determine which + * blocks need to be scrubbed (i.e. those written during the time + * the vdev was offline). It also ensures that the key used in + * the ARC hash table is unique (i.e. dva[0] + phys_birth). If + * we didn't change the phys_birth, a lookup in the ARC for a + * remapped BP could find the data that was previously stored at + * this vdev + offset. + */ + vdev_t *oldvd = vdev_lookup_top(vd->vdev_spa, + DVA_GET_VDEV(&bp->blk_dva[0])); + vdev_indirect_births_t *vib = oldvd->vdev_indirect_births; + bp->blk_phys_birth = vdev_indirect_births_physbirth(vib, + DVA_GET_OFFSET(&bp->blk_dva[0]), DVA_GET_ASIZE(&bp->blk_dva[0])); + + DVA_SET_VDEV(&bp->blk_dva[0], vd->vdev_id); + DVA_SET_OFFSET(&bp->blk_dva[0], offset); +} + +/* + * If the block pointer contains any indirect DVAs, modify them to refer to + * concrete DVAs. Note that this will sometimes not be possible, leaving + * the indirect DVA in place. This happens if the indirect DVA spans multiple + * segments in the mapping (i.e. it is a "split block"). + * + * If the BP was remapped, calls the callback on the original dva (note the + * callback can be called multiple times if the original indirect DVA refers + * to another indirect DVA, etc). + * + * Returns TRUE if the BP was remapped. + */ +boolean_t +spa_remap_blkptr(spa_t *spa, blkptr_t *bp, spa_remap_cb_t callback, void *arg) +{ + remap_blkptr_cb_arg_t rbca; + + if (!zfs_remap_blkptr_enable) + return (B_FALSE); + + if (!spa_feature_is_enabled(spa, SPA_FEATURE_OBSOLETE_COUNTS)) + return (B_FALSE); + + /* + * Dedup BP's can not be remapped, because ddt_phys_select() depends + * on DVA[0] being the same in the BP as in the DDT (dedup table). + */ + if (BP_GET_DEDUP(bp)) + return (B_FALSE); + + /* + * Gang blocks can not be remapped, because + * zio_checksum_gang_verifier() depends on the DVA[0] that's in + * the BP used to read the gang block header (GBH) being the same + * as the DVA[0] that we allocated for the GBH. + */ + if (BP_IS_GANG(bp)) + return (B_FALSE); + + /* + * Embedded BP's have no DVA to remap. + */ + if (BP_GET_NDVAS(bp) < 1) + return (B_FALSE); + + /* + * Note: we only remap dva[0]. If we remapped other dvas, we + * would no longer know what their phys birth txg is. + */ + dva_t *dva = &bp->blk_dva[0]; + + uint64_t offset = DVA_GET_OFFSET(dva); + uint64_t size = DVA_GET_ASIZE(dva); + vdev_t *vd = vdev_lookup_top(spa, DVA_GET_VDEV(dva)); + + if (vd->vdev_ops->vdev_op_remap == NULL) + return (B_FALSE); + + rbca.rbca_bp = bp; + rbca.rbca_cb = callback; + rbca.rbca_remap_vd = vd; + rbca.rbca_remap_offset = offset; + rbca.rbca_cb_arg = arg; + + /* + * remap_blkptr_cb() will be called in order for each level of + * indirection, until a concrete vdev is reached or a split block is + * encountered. old_vd and old_offset are updated within the callback + * as we go from the one indirect vdev to the next one (either concrete + * or indirect again) in that order. + */ + vd->vdev_ops->vdev_op_remap(vd, offset, size, remap_blkptr_cb, &rbca); + + /* Check if the DVA wasn't remapped because it is a split block */ + if (DVA_GET_VDEV(&rbca.rbca_bp->blk_dva[0]) == vd->vdev_id) + return (B_FALSE); + + return (B_TRUE); +} + +/* + * Undo the allocation of a DVA which happened in the given transaction group. + */ +void +metaslab_unalloc_dva(spa_t *spa, const dva_t *dva, uint64_t txg) +{ + metaslab_t *msp; + vdev_t *vd; + uint64_t vdev = DVA_GET_VDEV(dva); + uint64_t offset = DVA_GET_OFFSET(dva); + uint64_t size = DVA_GET_ASIZE(dva); + + ASSERT(DVA_IS_VALID(dva)); + ASSERT3U(spa_config_held(spa, SCL_ALL, RW_READER), !=, 0); + + if (txg > spa_freeze_txg(spa)) + return; + + if ((vd = vdev_lookup_top(spa, vdev)) == NULL || + (offset >> vd->vdev_ms_shift) >= vd->vdev_ms_count) { + cmn_err(CE_WARN, "metaslab_free_dva(): bad DVA %llu:%llu", + (u_longlong_t)vdev, (u_longlong_t)offset); + ASSERT(0); + return; + } + + ASSERT(!vd->vdev_removing); + ASSERT(vdev_is_concrete(vd)); + ASSERT0(vd->vdev_indirect_config.vic_mapping_object); + ASSERT3P(vd->vdev_indirect_mapping, ==, NULL); + + if (DVA_GET_GANG(dva)) + size = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE); + + msp = vd->vdev_ms[offset >> vd->vdev_ms_shift]; + + mutex_enter(&msp->ms_lock); + range_tree_remove(msp->ms_allocating[txg & TXG_MASK], + offset, size); + + VERIFY(!msp->ms_condensing); + VERIFY3U(offset, >=, msp->ms_start); + VERIFY3U(offset + size, <=, msp->ms_start + msp->ms_size); + VERIFY3U(range_tree_space(msp->ms_allocatable) + size, <=, + msp->ms_size); + VERIFY0(P2PHASE(offset, 1ULL << vd->vdev_ashift)); + VERIFY0(P2PHASE(size, 1ULL << vd->vdev_ashift)); + range_tree_add(msp->ms_allocatable, offset, size); + mutex_exit(&msp->ms_lock); +} + +/* + * Free the block represented by the given DVA. + */ +void +metaslab_free_dva(spa_t *spa, const dva_t *dva, boolean_t checkpoint) +{ + uint64_t vdev = DVA_GET_VDEV(dva); + uint64_t offset = DVA_GET_OFFSET(dva); + uint64_t size = DVA_GET_ASIZE(dva); + vdev_t *vd = vdev_lookup_top(spa, vdev); + + ASSERT(DVA_IS_VALID(dva)); + ASSERT3U(spa_config_held(spa, SCL_ALL, RW_READER), !=, 0); + + if (DVA_GET_GANG(dva)) { + size = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE); + } + + metaslab_free_impl(vd, offset, size, checkpoint); +} + +/* + * Reserve some allocation slots. The reservation system must be called + * before we call into the allocator. If there aren't any available slots + * then the I/O will be throttled until an I/O completes and its slots are + * freed up. The function returns true if it was successful in placing + * the reservation. + */ +boolean_t +metaslab_class_throttle_reserve(metaslab_class_t *mc, int slots, int allocator, + zio_t *zio, int flags) +{ + uint64_t available_slots = 0; + boolean_t slot_reserved = B_FALSE; + uint64_t max = mc->mc_alloc_max_slots[allocator]; + + ASSERT(mc->mc_alloc_throttle_enabled); + mutex_enter(&mc->mc_lock); + + uint64_t reserved_slots = + refcount_count(&mc->mc_alloc_slots[allocator]); + if (reserved_slots < max) + available_slots = max - reserved_slots; + + if (slots <= available_slots || GANG_ALLOCATION(flags)) { + /* + * We reserve the slots individually so that we can unreserve + * them individually when an I/O completes. + */ + for (int d = 0; d < slots; d++) { + reserved_slots = + refcount_add(&mc->mc_alloc_slots[allocator], + zio); + } + zio->io_flags |= ZIO_FLAG_IO_ALLOCATING; + slot_reserved = B_TRUE; + } + + mutex_exit(&mc->mc_lock); + return (slot_reserved); +} + +void +metaslab_class_throttle_unreserve(metaslab_class_t *mc, int slots, + int allocator, zio_t *zio) +{ + ASSERT(mc->mc_alloc_throttle_enabled); + mutex_enter(&mc->mc_lock); + for (int d = 0; d < slots; d++) { + (void) refcount_remove(&mc->mc_alloc_slots[allocator], + zio); + } + mutex_exit(&mc->mc_lock); +} + +static int +metaslab_claim_concrete(vdev_t *vd, uint64_t offset, uint64_t size, + uint64_t txg) +{ + metaslab_t *msp; + spa_t *spa = vd->vdev_spa; + int error = 0; + + if (offset >> vd->vdev_ms_shift >= vd->vdev_ms_count) + return (ENXIO); + + ASSERT3P(vd->vdev_ms, !=, NULL); + msp = vd->vdev_ms[offset >> vd->vdev_ms_shift]; + + mutex_enter(&msp->ms_lock); + + if ((txg != 0 && spa_writeable(spa)) || !msp->ms_loaded) + error = metaslab_activate(msp, 0, METASLAB_WEIGHT_CLAIM); + /* + * No need to fail in that case; someone else has activated the + * metaslab, but that doesn't preclude us from using it. + */ + if (error == EBUSY) + error = 0; + + if (error == 0 && + !range_tree_contains(msp->ms_allocatable, offset, size)) + error = SET_ERROR(ENOENT); + + if (error || txg == 0) { /* txg == 0 indicates dry run */ + mutex_exit(&msp->ms_lock); + return (error); + } + + VERIFY(!msp->ms_condensing); + VERIFY0(P2PHASE(offset, 1ULL << vd->vdev_ashift)); + VERIFY0(P2PHASE(size, 1ULL << vd->vdev_ashift)); + VERIFY3U(range_tree_space(msp->ms_allocatable) - size, <=, + msp->ms_size); + range_tree_remove(msp->ms_allocatable, offset, size); + + if (spa_writeable(spa)) { /* don't dirty if we're zdb(1M) */ + if (range_tree_is_empty(msp->ms_allocating[txg & TXG_MASK])) + vdev_dirty(vd, VDD_METASLAB, msp, txg); + range_tree_add(msp->ms_allocating[txg & TXG_MASK], + offset, size); + } + + mutex_exit(&msp->ms_lock); + + return (0); +} + +typedef struct metaslab_claim_cb_arg_t { + uint64_t mcca_txg; + int mcca_error; +} metaslab_claim_cb_arg_t; + +/* ARGSUSED */ +static void +metaslab_claim_impl_cb(uint64_t inner_offset, vdev_t *vd, uint64_t offset, + uint64_t size, void *arg) +{ + metaslab_claim_cb_arg_t *mcca_arg = arg; + + if (mcca_arg->mcca_error == 0) { + mcca_arg->mcca_error = metaslab_claim_concrete(vd, offset, + size, mcca_arg->mcca_txg); + } +} + +int +metaslab_claim_impl(vdev_t *vd, uint64_t offset, uint64_t size, uint64_t txg) +{ + if (vd->vdev_ops->vdev_op_remap != NULL) { + metaslab_claim_cb_arg_t arg; + + /* + * Only zdb(1M) can claim on indirect vdevs. This is used + * to detect leaks of mapped space (that are not accounted + * for in the obsolete counts, spacemap, or bpobj). + */ + ASSERT(!spa_writeable(vd->vdev_spa)); + arg.mcca_error = 0; + arg.mcca_txg = txg; + + vd->vdev_ops->vdev_op_remap(vd, offset, size, + metaslab_claim_impl_cb, &arg); + + if (arg.mcca_error == 0) { + arg.mcca_error = metaslab_claim_concrete(vd, + offset, size, txg); + } + return (arg.mcca_error); + } else { + return (metaslab_claim_concrete(vd, offset, size, txg)); + } +} + +/* + * Intent log support: upon opening the pool after a crash, notify the SPA + * of blocks that the intent log has allocated for immediate write, but + * which are still considered free by the SPA because the last transaction + * group didn't commit yet. + */ +static int +metaslab_claim_dva(spa_t *spa, const dva_t *dva, uint64_t txg) +{ + uint64_t vdev = DVA_GET_VDEV(dva); + uint64_t offset = DVA_GET_OFFSET(dva); + uint64_t size = DVA_GET_ASIZE(dva); + vdev_t *vd; + + if ((vd = vdev_lookup_top(spa, vdev)) == NULL) { + return (SET_ERROR(ENXIO)); + } + + ASSERT(DVA_IS_VALID(dva)); + + if (DVA_GET_GANG(dva)) + size = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE); + + return (metaslab_claim_impl(vd, offset, size, txg)); +} + +int +metaslab_alloc(spa_t *spa, metaslab_class_t *mc, uint64_t psize, blkptr_t *bp, + int ndvas, uint64_t txg, blkptr_t *hintbp, int flags, + zio_alloc_list_t *zal, zio_t *zio, int allocator) +{ + dva_t *dva = bp->blk_dva; + dva_t *hintdva = hintbp->blk_dva; + int error = 0; + + ASSERT(bp->blk_birth == 0); + ASSERT(BP_PHYSICAL_BIRTH(bp) == 0); + + spa_config_enter(spa, SCL_ALLOC, FTAG, RW_READER); + + if (mc->mc_rotor == NULL) { /* no vdevs in this class */ + spa_config_exit(spa, SCL_ALLOC, FTAG); + return (SET_ERROR(ENOSPC)); + } + + ASSERT(ndvas > 0 && ndvas <= spa_max_replication(spa)); + ASSERT(BP_GET_NDVAS(bp) == 0); + ASSERT(hintbp == NULL || ndvas <= BP_GET_NDVAS(hintbp)); + ASSERT3P(zal, !=, NULL); + + for (int d = 0; d < ndvas; d++) { + error = metaslab_alloc_dva(spa, mc, psize, dva, d, hintdva, + txg, flags, zal, allocator); + if (error != 0) { + for (d--; d >= 0; d--) { + metaslab_unalloc_dva(spa, &dva[d], txg); + metaslab_group_alloc_decrement(spa, + DVA_GET_VDEV(&dva[d]), zio, flags, + allocator, B_FALSE); + bzero(&dva[d], sizeof (dva_t)); + } + spa_config_exit(spa, SCL_ALLOC, FTAG); + return (error); + } else { + /* + * Update the metaslab group's queue depth + * based on the newly allocated dva. + */ + metaslab_group_alloc_increment(spa, + DVA_GET_VDEV(&dva[d]), zio, flags, allocator); + } + + } + ASSERT(error == 0); + ASSERT(BP_GET_NDVAS(bp) == ndvas); + + spa_config_exit(spa, SCL_ALLOC, FTAG); + + BP_SET_BIRTH(bp, txg, txg); + + return (0); +} + +void +metaslab_free(spa_t *spa, const blkptr_t *bp, uint64_t txg, boolean_t now) +{ + const dva_t *dva = bp->blk_dva; + int ndvas = BP_GET_NDVAS(bp); + + ASSERT(!BP_IS_HOLE(bp)); + ASSERT(!now || bp->blk_birth >= spa_syncing_txg(spa)); + + /* + * If we have a checkpoint for the pool we need to make sure that + * the blocks that we free that are part of the checkpoint won't be + * reused until the checkpoint is discarded or we revert to it. + * + * The checkpoint flag is passed down the metaslab_free code path + * and is set whenever we want to add a block to the checkpoint's + * accounting. That is, we "checkpoint" blocks that existed at the + * time the checkpoint was created and are therefore referenced by + * the checkpointed uberblock. + * + * Note that, we don't checkpoint any blocks if the current + * syncing txg <= spa_checkpoint_txg. We want these frees to sync + * normally as they will be referenced by the checkpointed uberblock. + */ + boolean_t checkpoint = B_FALSE; + if (bp->blk_birth <= spa->spa_checkpoint_txg && + spa_syncing_txg(spa) > spa->spa_checkpoint_txg) { + /* + * At this point, if the block is part of the checkpoint + * there is no way it was created in the current txg. + */ + ASSERT(!now); + ASSERT3U(spa_syncing_txg(spa), ==, txg); + checkpoint = B_TRUE; + } + + spa_config_enter(spa, SCL_FREE, FTAG, RW_READER); + + for (int d = 0; d < ndvas; d++) { + if (now) { + metaslab_unalloc_dva(spa, &dva[d], txg); + } else { + ASSERT3U(txg, ==, spa_syncing_txg(spa)); + metaslab_free_dva(spa, &dva[d], checkpoint); + } + } + + spa_config_exit(spa, SCL_FREE, FTAG); +} + +int +metaslab_claim(spa_t *spa, const blkptr_t *bp, uint64_t txg) +{ + const dva_t *dva = bp->blk_dva; + int ndvas = BP_GET_NDVAS(bp); + int error = 0; + + ASSERT(!BP_IS_HOLE(bp)); + + if (txg != 0) { + /* + * First do a dry run to make sure all DVAs are claimable, + * so we don't have to unwind from partial failures below. + */ + if ((error = metaslab_claim(spa, bp, 0)) != 0) + return (error); + } + + spa_config_enter(spa, SCL_ALLOC, FTAG, RW_READER); + + for (int d = 0; d < ndvas; d++) + if ((error = metaslab_claim_dva(spa, &dva[d], txg)) != 0) + break; + + spa_config_exit(spa, SCL_ALLOC, FTAG); + + ASSERT(error == 0 || txg == 0); + + return (error); +} + +/* ARGSUSED */ +static void +metaslab_check_free_impl_cb(uint64_t inner, vdev_t *vd, uint64_t offset, + uint64_t size, void *arg) +{ + if (vd->vdev_ops == &vdev_indirect_ops) + return; + + metaslab_check_free_impl(vd, offset, size); +} + +static void +metaslab_check_free_impl(vdev_t *vd, uint64_t offset, uint64_t size) +{ + metaslab_t *msp; + spa_t *spa = vd->vdev_spa; + + if ((zfs_flags & ZFS_DEBUG_ZIO_FREE) == 0) + return; + + if (vd->vdev_ops->vdev_op_remap != NULL) { + vd->vdev_ops->vdev_op_remap(vd, offset, size, + metaslab_check_free_impl_cb, NULL); + return; + } + + ASSERT(vdev_is_concrete(vd)); + ASSERT3U(offset >> vd->vdev_ms_shift, <, vd->vdev_ms_count); + ASSERT3U(spa_config_held(spa, SCL_ALL, RW_READER), !=, 0); + + msp = vd->vdev_ms[offset >> vd->vdev_ms_shift]; + + mutex_enter(&msp->ms_lock); + if (msp->ms_loaded) + range_tree_verify(msp->ms_allocatable, offset, size); + + range_tree_verify(msp->ms_freeing, offset, size); + range_tree_verify(msp->ms_checkpointing, offset, size); + range_tree_verify(msp->ms_freed, offset, size); + for (int j = 0; j < TXG_DEFER_SIZE; j++) + range_tree_verify(msp->ms_defer[j], offset, size); + mutex_exit(&msp->ms_lock); +} + +void +metaslab_check_free(spa_t *spa, const blkptr_t *bp) +{ + if ((zfs_flags & ZFS_DEBUG_ZIO_FREE) == 0) + return; + + spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER); + for (int i = 0; i < BP_GET_NDVAS(bp); i++) { + uint64_t vdev = DVA_GET_VDEV(&bp->blk_dva[i]); + vdev_t *vd = vdev_lookup_top(spa, vdev); + uint64_t offset = DVA_GET_OFFSET(&bp->blk_dva[i]); + uint64_t size = DVA_GET_ASIZE(&bp->blk_dva[i]); + + if (DVA_GET_GANG(&bp->blk_dva[i])) + size = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE); + + ASSERT3P(vd, !=, NULL); + + metaslab_check_free_impl(vd, offset, size); + } + spa_config_exit(spa, SCL_VDEV, FTAG); +} |