*/
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2012 by Delphix. All rights reserved.
+ * Copyright (c) 2011, 2018 by Delphix. All rights reserved.
+ * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
+ * Copyright (c) 2017, Intel Corporation.
*/
#include <sys/zfs_context.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>
-#define WITH_DF_BLOCK_ALLOCATOR
+#define WITH_DF_BLOCK_ALLOCATOR
+
+#define GANG_ALLOCATION(flags) \
+ ((flags) & (METASLAB_GANG_CHILD | METASLAB_GANG_HEADER))
+
+/*
+ * Metaslab granularity, in bytes. This is roughly similar to what would be
+ * referred to as the "stripe size" in traditional RAID arrays. In normal
+ * operation, we will try to write this amount of data to a top-level vdev
+ * before moving on to the next one.
+ */
+unsigned long metaslab_aliquot = 512 << 10;
/*
- * Allow allocations to switch to gang blocks quickly. We do this to
- * avoid having to load lots of space_maps in a given txg. There are,
- * however, some cases where we want to avoid "fast" ganging and instead
- * we want to do an exhaustive search of all metaslabs on this device.
- * Currently we don't allow any gang, zil, or dump device related allocations
- * to "fast" gang.
+ * For testing, make some blocks above a certain size be gang blocks.
*/
-#define CAN_FASTGANG(flags) \
- (!((flags) & (METASLAB_GANG_CHILD | METASLAB_GANG_HEADER | \
- METASLAB_GANG_AVOID)))
+unsigned long metaslab_force_ganging = SPA_MAXBLOCKSIZE + 1;
-uint64_t metaslab_aliquot = 512ULL << 10;
-uint64_t metaslab_gang_bang = SPA_MAXBLOCKSIZE + 1; /* force gang blocks */
+/*
+ * 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);
/*
* 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.
+ * 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;
/*
- * This value defines the number of allowed allocation failures per vdev.
- * If a device reaches this threshold in a given txg then we consider skipping
- * allocations on that device.
+ * 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_blksz), 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;
+
+/*
+ * 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;
+
+/*
+ * 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;
+
+/*
+ * When set will load all metaslabs when pool is first opened.
*/
-int zfs_mg_alloc_failures;
+int metaslab_debug_load = 0;
/*
- * Metaslab debugging: when set, keeps all space maps in core to verify frees.
+ * When set will prevent metaslabs from being unloaded.
*/
-int metaslab_debug = 0;
+int metaslab_debug_unload = 0;
/*
* Minimum size which forces the dynamic allocator to change
* 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_MAXBLOCKSIZE;
+uint64_t metaslab_df_alloc_threshold = SPA_OLD_MAXBLOCKSIZE;
/*
* 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
+ * 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;
/*
- * A metaslab is considered "free" if it contains a contiguous
- * segment which is greater than metaslab_min_alloc_size.
+ * Percentage of all cpus that can be used by the metaslab taskq.
+ */
+int metaslab_load_pct = 50;
+
+/*
+ * 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;
+
+/*
+ * Max number of metaslabs per group to preload.
+ */
+int metaslab_preload_limit = SPA_DVAS_PER_BP;
+
+/*
+ * Enable/disable preloading of metaslab.
+ */
+int metaslab_preload_enabled = B_TRUE;
+
+/*
+ * Enable/disable fragmentation weighting on metaslabs.
+ */
+int metaslab_fragmentation_factor_enabled = B_TRUE;
+
+/*
+ * Enable/disable lba weighting (i.e. outer tracks are given preference).
+ */
+int metaslab_lba_weighting_enabled = B_TRUE;
+
+/*
+ * Enable/disable metaslab group biasing.
+ */
+int metaslab_bias_enabled = B_TRUE;
+
+
+/*
+ * Enable/disable remapping of indirect DVAs to their concrete vdevs.
*/
-uint64_t metaslab_min_alloc_size = DMU_MAX_ACCESS;
+boolean_t zfs_remap_blkptr_enable = B_TRUE;
/*
- * Max number of space_maps to prefetch.
+ * Enable/disable segment-based metaslab selection.
*/
-int metaslab_prefetch_limit = SPA_DVAS_PER_BP;
+int zfs_metaslab_segment_weight_enabled = B_TRUE;
/*
- * Percentage bonus multiplier for metaslabs that are in the bonus area.
+ * 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 metaslab_smo_bonus_pct = 150;
+int zfs_metaslab_switch_threshold = 2;
+
+/*
+ * Internal switch to enable/disable the metaslab allocation tracing
+ * facility.
+ */
+#ifdef _METASLAB_TRACING
+boolean_t metaslab_trace_enabled = B_TRUE;
+#endif
+
+/*
+ * 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.
+ */
+#ifdef _METASLAB_TRACING
+uint64_t metaslab_trace_max_entries = 5000;
+#endif
+
+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);
+#ifdef _METASLAB_TRACING
+kmem_cache_t *metaslab_alloc_trace_cache;
+#endif
/*
* ==========================================================================
* ==========================================================================
*/
metaslab_class_t *
-metaslab_class_create(spa_t *spa, space_map_ops_t *ops)
+metaslab_class_create(spa_t *spa, metaslab_ops_t *ops)
{
metaslab_class_t *mc;
- mc = kmem_zalloc(sizeof (metaslab_class_t), KM_PUSHPAGE);
+ 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_fastwrite_lock, NULL, MUTEX_DEFAULT, NULL);
+ mutex_init(&mc->mc_lock, NULL, MUTEX_DEFAULT, NULL);
+ mc->mc_alloc_slots = kmem_zalloc(spa->spa_alloc_count *
+ sizeof (zfs_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++)
+ zfs_refcount_create_tracked(&mc->mc_alloc_slots[i]);
return (mc);
}
ASSERT(mc->mc_space == 0);
ASSERT(mc->mc_dspace == 0);
- mutex_destroy(&mc->mc_fastwrite_lock);
+ for (int i = 0; i < mc->mc_spa->spa_alloc_count; i++)
+ zfs_refcount_destroy(&mc->mc_alloc_slots[i]);
+ kmem_free(mc->mc_alloc_slots, mc->mc_spa->spa_alloc_count *
+ sizeof (zfs_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));
}
return (0);
}
-void
+static 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)
{
return (spa_deflate(mc->mc_spa) ? mc->mc_dspace : mc->mc_space);
}
+void
+metaslab_class_histogram_verify(metaslab_class_t *mc)
+{
+ spa_t *spa = mc->mc_spa;
+ vdev_t *rvd = 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);
+}
+
/*
- * ==========================================================================
- * Metaslab groups
- * ==========================================================================
+ * 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++) {
+ 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.
+ */
+ space += P2ALIGN(tvd->vdev_max_asize - tvd->vdev_asize,
+ 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 = x1;
- const metaslab_t *m2 = x2;
-
- if (m1->ms_weight < m2->ms_weight)
- return (1);
- if (m1->ms_weight > m2->ms_weight)
- return (-1);
+ 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;
/*
- * If the weights are identical, use the offset to force uniqueness.
+ * 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 (m1->ms_map->sm_start < m2->ms_map->sm_start)
+ if (sort1 < sort2)
return (-1);
- if (m1->ms_map->sm_start > m2->ms_map->sm_start)
+ if (sort1 > sort2)
return (1);
- ASSERT3P(m1, ==, m2);
+ int cmp = AVL_CMP(m2->ms_weight, m1->ms_weight);
+ if (likely(cmp))
+ return (cmp);
- return (0);
+ IMPLY(AVL_CMP(m1->ms_start, m2->ms_start) == 0, m1 == m2);
+
+ return (AVL_CMP(m1->ms_start, m2->ms_start));
+}
+
+uint64_t
+metaslab_allocated_space(metaslab_t *msp)
+{
+ return (msp->ms_allocated_space);
+}
+
+/*
+ * Verify that the space accounting on disk matches the in-core range_trees.
+ */
+static void
+metaslab_verify_space(metaslab_t *msp, uint64_t txg)
+{
+ spa_t *spa = msp->ms_group->mg_vd->vdev_spa;
+ uint64_t allocating = 0;
+ uint64_t sm_free_space, msp_free_space;
+
+ ASSERT(MUTEX_HELD(&msp->ms_lock));
+ ASSERT(!msp->ms_condensing);
+
+ 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;
+
+ /*
+ * Even though the smp_alloc field can get negative (e.g.
+ * see vdev_checkpoint_sm), that should never be the case
+ * when it come's to a metaslab's space map.
+ */
+ ASSERT3S(space_map_allocated(msp->ms_sm), >=, 0);
+
+ sm_free_space = msp->ms_size - metaslab_allocated_space(msp);
+
+ /*
+ * Account for future allocations since we would have
+ * already deducted that space from the ms_allocatable.
+ */
+ for (int t = 0; t < TXG_CONCURRENT_STATES; t++) {
+ allocating +=
+ range_tree_space(msp->ms_allocating[(txg + t) & TXG_MASK]);
+ }
+
+ ASSERT3U(msp->ms_deferspace, ==,
+ range_tree_space(msp->ms_defer[0]) +
+ range_tree_space(msp->ms_defer[1]));
+
+ msp_free_space = range_tree_space(msp->ms_allocatable) + allocating +
+ 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)
+metaslab_group_create(metaslab_class_t *mc, vdev_t *vd, int allocators)
{
metaslab_group_t *mg;
- mg = kmem_zalloc(sizeof (metaslab_group_t), KM_PUSHPAGE);
+ 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 (zfs_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++) {
+ zfs_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,
+ maxclsyspri, 10, INT_MAX, TASKQ_THREADS_CPU_PCT | TASKQ_DYNAMIC);
return (mg);
}
*/
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++) {
+ zfs_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 (zfs_refcount_t));
+ kmem_free(mg->mg_cur_max_alloc_queue_depth, mg->mg_allocators *
+ sizeof (uint64_t));
+
kmem_free(mg, sizeof (metaslab_group_t));
}
metaslab_class_t *mc = mg->mg_class;
metaslab_group_t *mgprev, *mgnext;
- ASSERT(spa_config_held(mc->mc_spa, SCL_ALLOC, RW_WRITER));
+ ASSERT3U(spa_config_held(mc->mc_spa, SCL_ALLOC, RW_WRITER), !=, 0);
ASSERT(mc->mc_rotor != mg);
ASSERT(mg->mg_prev == NULL);
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;
mc->mc_rotor = mg;
}
+/*
+ * 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);
- ASSERT(spa_config_held(mc->mc_spa, SCL_ALLOC, 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);
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_outstanding(mg->mg_taskq, 0);
+ 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;
mg->mg_next = NULL;
}
+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];
+ ASSERT(msp != NULL);
+
+ /* skip if not active or not a member */
+ if (msp->ms_sm == NULL || msp->ms_group != mg)
+ 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_add(metaslab_group_t *mg, metaslab_t *msp)
+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);
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, 510].
+ * practice we do not use values in the range [1, 511].
*/
- ASSERT(weight >= SPA_MINBLOCKSIZE-1 || weight == 0);
+ ASSERT(weight >= SPA_MINBLOCKSIZE || weight == 0);
ASSERT(MUTEX_HELD(&msp->ms_lock));
mutex_enter(&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);
+ metaslab_group_sort_impl(mg, msp, weight);
mutex_exit(&mg->mg_lock);
}
/*
- * ==========================================================================
- * Common allocator routines
- * ==========================================================================
+ * 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.
*/
-static int
-metaslab_segsize_compare(const void *x1, const void *x2)
+uint64_t
+metaslab_group_fragmentation(metaslab_group_t *mg)
{
- const space_seg_t *s1 = x1;
- const space_seg_t *s2 = x2;
- uint64_t ss_size1 = s1->ss_end - s1->ss_start;
- uint64_t ss_size2 = s2->ss_end - s2->ss_start;
+ vdev_t *vd = mg->mg_vd;
+ uint64_t fragmentation = 0;
+ uint64_t valid_ms = 0;
- if (ss_size1 < ss_size2)
- return (-1);
- if (ss_size1 > ss_size2)
- return (1);
+ for (int m = 0; m < vd->vdev_ms_count; m++) {
+ metaslab_t *msp = vd->vdev_ms[m];
- if (s1->ss_start < s2->ss_start)
- return (-1);
- if (s1->ss_start > s2->ss_start)
- return (1);
+ if (msp->ms_fragmentation == ZFS_FRAG_INVALID)
+ continue;
+ if (msp->ms_group != mg)
+ continue;
- return (0);
+ valid_ms++;
+ fragmentation += msp->ms_fragmentation;
+ }
+
+ if (valid_ms <= mg->mg_vd->vdev_ms_count / 2)
+ return (ZFS_FRAG_INVALID);
+
+ fragmentation /= valid_ms;
+ ASSERT3U(fragmentation, <=, 100);
+ return (fragmentation);
}
-#if defined(WITH_FF_BLOCK_ALLOCATOR) || \
- defined(WITH_DF_BLOCK_ALLOCATOR) || \
- defined(WITH_CDF_BLOCK_ALLOCATOR)
/*
- * 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.
+ * 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 uint64_t
-metaslab_block_picker(avl_tree_t *t, uint64_t *cursor, uint64_t size,
- uint64_t align)
+static boolean_t
+metaslab_group_allocatable(metaslab_group_t *mg, metaslab_group_t *rotor,
+ uint64_t psize, int allocator, int d)
{
- space_seg_t *ss, ssearch;
- avl_index_t where;
+ spa_t *spa = mg->mg_vd->vdev_spa;
+ metaslab_class_t *mc = mg->mg_class;
- ssearch.ss_start = *cursor;
- ssearch.ss_end = *cursor + size;
+ /*
+ * 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 != spa_special_class(spa) &&
+ mc != spa_dedup_class(spa)) ||
+ mc->mc_groups <= 1)
+ return (B_TRUE);
- ss = avl_find(t, &ssearch, &where);
- if (ss == NULL)
- ss = avl_nearest(t, where, AVL_AFTER);
+ /*
+ * 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];
- while (ss != NULL) {
- uint64_t offset = P2ROUNDUP(ss->ss_start, align);
+ if (!mc->mc_alloc_throttle_enabled)
+ return (B_TRUE);
- if (offset + size <= ss->ss_end) {
- *cursor = offset + size;
- return (offset);
- }
- ss = AVL_NEXT(t, ss);
- }
+ /*
+ * 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);
- /*
- * 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);
+ /*
+ * 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;
- *cursor = 0;
- return (metaslab_block_picker(t, cursor, size, align));
-}
-#endif /* WITH_FF/DF/CDF_BLOCK_ALLOCATOR */
+ qdepth = zfs_refcount_count(
+ &mg->mg_alloc_queue_depth[allocator]);
-static void
-metaslab_pp_load(space_map_t *sm)
-{
- space_seg_t *ss;
+ /*
+ * 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 = zfs_refcount_count(
+ &mgp->mg_alloc_queue_depth[allocator]);
- ASSERT(sm->sm_ppd == NULL);
- sm->sm_ppd = kmem_zalloc(64 * sizeof (uint64_t), KM_PUSHPAGE);
+ /*
+ * 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);
+ }
- sm->sm_pp_root = kmem_alloc(sizeof (avl_tree_t), KM_PUSHPAGE);
- avl_create(sm->sm_pp_root, metaslab_segsize_compare,
- sizeof (space_seg_t), offsetof(struct space_seg, ss_pp_node));
+ /*
+ * 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);
- for (ss = avl_first(&sm->sm_root); ss; ss = AVL_NEXT(&sm->sm_root, ss))
- avl_add(sm->sm_pp_root, ss);
+ } else if (mc->mc_alloc_groups == 0 || psize == SPA_MINBLOCKSIZE) {
+ return (B_TRUE);
+ }
+ return (B_FALSE);
}
-static void
-metaslab_pp_unload(space_map_t *sm)
-{
- void *cookie = NULL;
+/*
+ * ==========================================================================
+ * Range tree callbacks
+ * ==========================================================================
+ */
- kmem_free(sm->sm_ppd, 64 * sizeof (uint64_t));
- sm->sm_ppd = NULL;
+/*
+ * 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;
- while (avl_destroy_nodes(sm->sm_pp_root, &cookie) != NULL) {
- /* tear down the tree */
- }
+ int cmp = AVL_CMP(rs_size1, rs_size2);
+ if (likely(cmp))
+ return (cmp);
- avl_destroy(sm->sm_pp_root);
- kmem_free(sm->sm_pp_root, sizeof (avl_tree_t));
- sm->sm_pp_root = NULL;
+ return (AVL_CMP(r1->rs_start, r2->rs_start));
}
-/* ARGSUSED */
-static void
-metaslab_pp_claim(space_map_t *sm, uint64_t start, uint64_t size)
+/*
+ * ==========================================================================
+ * Common allocator routines
+ * ==========================================================================
+ */
+
+/*
+ * Return the maximum contiguous segment within the metaslab.
+ */
+uint64_t
+metaslab_block_maxsize(metaslab_t *msp)
{
- /* No need to update cursor */
+ 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);
}
-/* ARGSUSED */
-static void
-metaslab_pp_free(space_map_t *sm, uint64_t start, uint64_t size)
+static range_seg_t *
+metaslab_block_find(avl_tree_t *t, uint64_t start, uint64_t size)
{
- /* No need to update cursor */
+ 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);
}
+#if defined(WITH_FF_BLOCK_ALLOCATOR) || \
+ defined(WITH_DF_BLOCK_ALLOCATOR) || \
+ defined(WITH_CF_BLOCK_ALLOCATOR)
/*
- * Return the maximum contiguous segment within the metaslab.
+ * 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.
*/
-uint64_t
-metaslab_pp_maxsize(space_map_t *sm)
+static uint64_t
+metaslab_block_picker(avl_tree_t *t, uint64_t *cursor, uint64_t size,
+ uint64_t align)
{
- avl_tree_t *t = sm->sm_pp_root;
- space_seg_t *ss;
+ range_seg_t *rs = metaslab_block_find(t, *cursor, size);
- if (t == NULL || (ss = avl_last(t)) == NULL)
- return (0ULL);
+ 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);
- return (ss->ss_end - ss->ss_start);
+ *cursor = 0;
+ return (metaslab_block_picker(t, cursor, size, align));
}
+#endif /* WITH_FF/DF/CF_BLOCK_ALLOCATOR */
#if defined(WITH_FF_BLOCK_ALLOCATOR)
/*
* ==========================================================================
*/
static uint64_t
-metaslab_ff_alloc(space_map_t *sm, uint64_t size)
+metaslab_ff_alloc(metaslab_t *msp, uint64_t size)
{
- avl_tree_t *t = &sm->sm_root;
+ /*
+ * 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 = (uint64_t *)sm->sm_ppd + highbit(align) - 1;
+ 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));
}
-/* ARGSUSED */
-boolean_t
-metaslab_ff_fragmented(space_map_t *sm)
-{
- return (B_TRUE);
-}
-
-static space_map_ops_t metaslab_ff_ops = {
- metaslab_pp_load,
- metaslab_pp_unload,
- metaslab_ff_alloc,
- metaslab_pp_claim,
- metaslab_pp_free,
- metaslab_pp_maxsize,
- metaslab_ff_fragmented
+static metaslab_ops_t metaslab_ff_ops = {
+ metaslab_ff_alloc
};
-space_map_ops_t *zfs_metaslab_ops = &metaslab_ff_ops;
+metaslab_ops_t *zfs_metaslab_ops = &metaslab_ff_ops;
#endif /* WITH_FF_BLOCK_ALLOCATOR */
#if defined(WITH_DF_BLOCK_ALLOCATOR)
* ==========================================================================
*/
static uint64_t
-metaslab_df_alloc(space_map_t *sm, uint64_t size)
+metaslab_df_alloc(metaslab_t *msp, uint64_t size)
{
- avl_tree_t *t = &sm->sm_root;
+ /*
+ * 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 = (uint64_t *)sm->sm_ppd + highbit(align) - 1;
- uint64_t max_size = metaslab_pp_maxsize(sm);
- int free_pct = sm->sm_space * 100 / sm->sm_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(sm->sm_lock));
- ASSERT3U(avl_numnodes(&sm->sm_root), ==, avl_numnodes(sm->sm_pp_root));
+ ASSERT(MUTEX_HELD(&msp->ms_lock));
+ ASSERT3U(avl_numnodes(t), ==,
+ avl_numnodes(&msp->ms_allocatable_by_size));
if (max_size < size)
return (-1ULL);
*/
if (max_size < metaslab_df_alloc_threshold ||
free_pct < metaslab_df_free_pct) {
- t = sm->sm_pp_root;
+ t = &msp->ms_allocatable_by_size;
*cursor = 0;
}
return (metaslab_block_picker(t, cursor, size, 1ULL));
}
-static boolean_t
-metaslab_df_fragmented(space_map_t *sm)
-{
- uint64_t max_size = metaslab_pp_maxsize(sm);
- int free_pct = sm->sm_space * 100 / sm->sm_size;
-
- if (max_size >= metaslab_df_alloc_threshold &&
- free_pct >= metaslab_df_free_pct)
- return (B_FALSE);
-
- return (B_TRUE);
-}
-
-static space_map_ops_t metaslab_df_ops = {
- metaslab_pp_load,
- metaslab_pp_unload,
- metaslab_df_alloc,
- metaslab_pp_claim,
- metaslab_pp_free,
- metaslab_pp_maxsize,
- metaslab_df_fragmented
+static metaslab_ops_t metaslab_df_ops = {
+ metaslab_df_alloc
};
-space_map_ops_t *zfs_metaslab_ops = &metaslab_df_ops;
+metaslab_ops_t *zfs_metaslab_ops = &metaslab_df_ops;
#endif /* WITH_DF_BLOCK_ALLOCATOR */
+#if defined(WITH_CF_BLOCK_ALLOCATOR)
/*
* ==========================================================================
- * Other experimental allocators
+ * 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.
* ==========================================================================
*/
-#if defined(WITH_CDF_BLOCK_ALLOCATOR)
static uint64_t
-metaslab_cdf_alloc(space_map_t *sm, uint64_t size)
+metaslab_cf_alloc(metaslab_t *msp, uint64_t size)
{
- avl_tree_t *t = &sm->sm_root;
- uint64_t *cursor = (uint64_t *)sm->sm_ppd;
- uint64_t *extent_end = (uint64_t *)sm->sm_ppd + 1;
- uint64_t max_size = metaslab_pp_maxsize(sm);
- uint64_t rsize = 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(sm->sm_lock));
- ASSERT3U(avl_numnodes(&sm->sm_root), ==, avl_numnodes(sm->sm_pp_root));
-
- if (max_size < size)
- return (-1ULL);
+ ASSERT(MUTEX_HELD(&msp->ms_lock));
+ ASSERT3U(avl_numnodes(t), ==, avl_numnodes(&rt->rt_root));
- ASSERT3U(*extent_end, >=, *cursor);
+ ASSERT3U(*cursor_end, >=, *cursor);
- /*
- * If we're running low on space switch to using the size
- * sorted AVL tree (best-fit).
- */
- if ((*cursor + size) > *extent_end) {
+ if ((*cursor + size) > *cursor_end) {
+ range_seg_t *rs;
- t = sm->sm_pp_root;
- *cursor = *extent_end = 0;
+ rs = avl_last(&msp->ms_allocatable_by_size);
+ if (rs == NULL || (rs->rs_end - rs->rs_start) < size)
+ return (-1ULL);
- if (max_size > 2 * SPA_MAXBLOCKSIZE)
- rsize = MIN(metaslab_min_alloc_size, max_size);
- offset = metaslab_block_picker(t, extent_end, rsize, 1ULL);
- if (offset != -1)
- *cursor = offset + size;
- } else {
- offset = metaslab_block_picker(t, cursor, rsize, 1ULL);
+ *cursor = rs->rs_start;
+ *cursor_end = rs->rs_end;
}
- ASSERT3U(*cursor, <=, *extent_end);
- return (offset);
-}
-static boolean_t
-metaslab_cdf_fragmented(space_map_t *sm)
-{
- uint64_t max_size = metaslab_pp_maxsize(sm);
+ offset = *cursor;
+ *cursor += size;
- if (max_size > (metaslab_min_alloc_size * 10))
- return (B_FALSE);
- return (B_TRUE);
+ return (offset);
}
-static space_map_ops_t metaslab_cdf_ops = {
- metaslab_pp_load,
- metaslab_pp_unload,
- metaslab_cdf_alloc,
- metaslab_pp_claim,
- metaslab_pp_free,
- metaslab_pp_maxsize,
- metaslab_cdf_fragmented
+static metaslab_ops_t metaslab_cf_ops = {
+ metaslab_cf_alloc
};
-space_map_ops_t *zfs_metaslab_ops = &metaslab_cdf_ops;
-#endif /* WITH_CDF_BLOCK_ALLOCATOR */
+metaslab_ops_t *zfs_metaslab_ops = &metaslab_cf_ops;
+#endif /* WITH_CF_BLOCK_ALLOCATOR */
#if defined(WITH_NDF_BLOCK_ALLOCATOR)
+/*
+ * ==========================================================================
+ * 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(space_map_t *sm, uint64_t size)
+metaslab_ndf_alloc(metaslab_t *msp, uint64_t size)
{
- avl_tree_t *t = &sm->sm_root;
+ avl_tree_t *t = &msp->ms_allocatable->rt_root;
avl_index_t where;
- space_seg_t *ss, ssearch;
- uint64_t hbit = highbit(size);
- uint64_t *cursor = (uint64_t *)sm->sm_ppd + hbit - 1;
- uint64_t max_size = metaslab_pp_maxsize(sm);
+ 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(sm->sm_lock));
- ASSERT3U(avl_numnodes(&sm->sm_root), ==, avl_numnodes(sm->sm_pp_root));
+ ASSERT(MUTEX_HELD(&msp->ms_lock));
+ ASSERT3U(avl_numnodes(t), ==,
+ avl_numnodes(&msp->ms_allocatable_by_size));
if (max_size < size)
return (-1ULL);
- ssearch.ss_start = *cursor;
- ssearch.ss_end = *cursor + size;
+ rsearch.rs_start = *cursor;
+ rsearch.rs_end = *cursor + size;
- ss = avl_find(t, &ssearch, &where);
- if (ss == NULL || (ss->ss_start + size > ss->ss_end)) {
- t = sm->sm_pp_root;
+ rs = avl_find(t, &rsearch, &where);
+ if (rs == NULL || (rs->rs_end - rs->rs_start) < size) {
+ t = &msp->ms_allocatable_by_size;
- ssearch.ss_start = 0;
- ssearch.ss_end = MIN(max_size,
+ rsearch.rs_start = 0;
+ rsearch.rs_end = MIN(max_size,
1ULL << (hbit + metaslab_ndf_clump_shift));
- ss = avl_find(t, &ssearch, &where);
- if (ss == NULL)
- ss = avl_nearest(t, where, AVL_AFTER);
- ASSERT(ss != NULL);
+ rs = avl_find(t, &rsearch, &where);
+ if (rs == NULL)
+ rs = avl_nearest(t, where, AVL_AFTER);
+ ASSERT(rs != NULL);
}
- if (ss != NULL) {
- if (ss->ss_start + size <= ss->ss_end) {
- *cursor = ss->ss_start + size;
- return (ss->ss_start);
- }
+ if ((rs->rs_end - rs->rs_start) >= size) {
+ *cursor = rs->rs_start + size;
+ return (rs->rs_start);
}
return (-1ULL);
}
-static boolean_t
-metaslab_ndf_fragmented(space_map_t *sm)
-{
- uint64_t max_size = metaslab_pp_maxsize(sm);
-
- if (max_size > (metaslab_min_alloc_size << metaslab_ndf_clump_shift))
- return (B_FALSE);
- return (B_TRUE);
-}
-
-
-static space_map_ops_t metaslab_ndf_ops = {
- metaslab_pp_load,
- metaslab_pp_unload,
- metaslab_ndf_alloc,
- metaslab_pp_claim,
- metaslab_pp_free,
- metaslab_pp_maxsize,
- metaslab_ndf_fragmented
+static metaslab_ops_t metaslab_ndf_ops = {
+ metaslab_ndf_alloc
};
-space_map_ops_t *zfs_metaslab_ops = &metaslab_ndf_ops;
+metaslab_ops_t *zfs_metaslab_ops = &metaslab_ndf_ops;
#endif /* WITH_NDF_BLOCK_ALLOCATOR */
+
/*
* ==========================================================================
* Metaslabs
* ==========================================================================
*/
-metaslab_t *
-metaslab_init(metaslab_group_t *mg, space_map_obj_t *smo,
- uint64_t start, uint64_t size, uint64_t txg)
-{
- vdev_t *vd = mg->mg_vd;
- metaslab_t *msp;
-
- msp = kmem_zalloc(sizeof (metaslab_t), KM_PUSHPAGE);
- mutex_init(&msp->ms_lock, NULL, MUTEX_DEFAULT, NULL);
-
- msp->ms_smo_syncing = *smo;
+static void
+metaslab_aux_histograms_clear(metaslab_t *msp)
+{
/*
- * We create the main space map here, but we don't create the
- * allocmaps and freemaps 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.
+ * Auxiliary histograms are only cleared when resetting them,
+ * which can only happen while the metaslab is loaded.
*/
- msp->ms_map = kmem_zalloc(sizeof (space_map_t), KM_PUSHPAGE);
- space_map_create(msp->ms_map, start, size,
- vd->vdev_ashift, &msp->ms_lock);
-
- metaslab_group_add(mg, msp);
+ ASSERT(msp->ms_loaded);
- if (metaslab_debug && smo->smo_object != 0) {
- mutex_enter(&msp->ms_lock);
- VERIFY(space_map_load(msp->ms_map, mg->mg_class->mc_ops,
- SM_FREE, smo, spa_meta_objset(vd->vdev_spa)) == 0);
- mutex_exit(&msp->ms_lock);
- }
+ bzero(msp->ms_synchist, sizeof (msp->ms_synchist));
+ for (int t = 0; t < TXG_DEFER_SIZE; t++)
+ bzero(msp->ms_deferhist[t], sizeof (msp->ms_deferhist[t]));
+}
+static void
+metaslab_aux_histogram_add(uint64_t *histogram, uint64_t shift,
+ range_tree_t *rt)
+{
/*
- * 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.
+ * This is modeled after space_map_histogram_add(), so refer to that
+ * function for implementation details. We want this to work like
+ * the space map histogram, and not the range tree histogram, as we
+ * are essentially constructing a delta that will be later subtracted
+ * from the space map histogram.
*/
- if (txg <= TXG_INITIAL)
- metaslab_sync_done(msp, 0);
-
- if (txg != 0) {
- vdev_dirty(vd, 0, NULL, txg);
- vdev_dirty(vd, VDD_METASLAB, msp, txg);
+ int idx = 0;
+ for (int i = shift; i < RANGE_TREE_HISTOGRAM_SIZE; i++) {
+ ASSERT3U(i, >=, idx + shift);
+ histogram[idx] += rt->rt_histogram[i] << (i - idx - shift);
+
+ if (idx < SPACE_MAP_HISTOGRAM_SIZE - 1) {
+ ASSERT3U(idx + shift, ==, i);
+ idx++;
+ ASSERT3U(idx, <, SPACE_MAP_HISTOGRAM_SIZE);
+ }
}
-
- return (msp);
}
-void
-metaslab_fini(metaslab_t *msp)
+/*
+ * Called at every sync pass that the metaslab gets synced.
+ *
+ * The reason is that we want our auxiliary histograms to be updated
+ * wherever the metaslab's space map histogram is updated. This way
+ * we stay consistent on which parts of the metaslab space map's
+ * histogram are currently not available for allocations (e.g because
+ * they are in the defer, freed, and freeing trees).
+ */
+static void
+metaslab_aux_histograms_update(metaslab_t *msp)
{
- metaslab_group_t *mg = msp->ms_group;
- int t;
-
- vdev_space_update(mg->mg_vd,
- -msp->ms_smo.smo_alloc, 0, -msp->ms_map->sm_size);
+ space_map_t *sm = msp->ms_sm;
+ ASSERT(sm != NULL);
- metaslab_group_remove(mg, msp);
-
- mutex_enter(&msp->ms_lock);
+ /*
+ * This is similar to the metaslab's space map histogram updates
+ * that take place in metaslab_sync(). The only difference is that
+ * we only care about segments that haven't made it into the
+ * ms_allocatable tree yet.
+ */
+ if (msp->ms_loaded) {
+ metaslab_aux_histograms_clear(msp);
- space_map_unload(msp->ms_map);
- space_map_destroy(msp->ms_map);
- kmem_free(msp->ms_map, sizeof (*msp->ms_map));
+ metaslab_aux_histogram_add(msp->ms_synchist,
+ sm->sm_shift, msp->ms_freed);
- for (t = 0; t < TXG_SIZE; t++) {
- space_map_destroy(msp->ms_allocmap[t]);
- space_map_destroy(msp->ms_freemap[t]);
- kmem_free(msp->ms_allocmap[t], sizeof (*msp->ms_allocmap[t]));
- kmem_free(msp->ms_freemap[t], sizeof (*msp->ms_freemap[t]));
+ for (int t = 0; t < TXG_DEFER_SIZE; t++) {
+ metaslab_aux_histogram_add(msp->ms_deferhist[t],
+ sm->sm_shift, msp->ms_defer[t]);
+ }
}
- for (t = 0; t < TXG_DEFER_SIZE; t++) {
- space_map_destroy(msp->ms_defermap[t]);
- kmem_free(msp->ms_defermap[t], sizeof (*msp->ms_defermap[t]));
- }
+ metaslab_aux_histogram_add(msp->ms_synchist,
+ sm->sm_shift, msp->ms_freeing);
+}
- ASSERT0(msp->ms_deferspace);
+/*
+ * Called every time we are done syncing (writing to) the metaslab,
+ * i.e. at the end of each sync pass.
+ * [see the comment in metaslab_impl.h for ms_synchist, ms_deferhist]
+ */
+static void
+metaslab_aux_histograms_update_done(metaslab_t *msp, boolean_t defer_allowed)
+{
+ spa_t *spa = msp->ms_group->mg_vd->vdev_spa;
+ space_map_t *sm = msp->ms_sm;
- mutex_exit(&msp->ms_lock);
- mutex_destroy(&msp->ms_lock);
+ if (sm == NULL) {
+ /*
+ * We came here from metaslab_init() when creating/opening a
+ * pool, looking at a metaslab that hasn't had any allocations
+ * yet.
+ */
+ return;
+ }
- kmem_free(msp, sizeof (metaslab_t));
+ /*
+ * This is similar to the actions that we take for the ms_freed
+ * and ms_defer trees in metaslab_sync_done().
+ */
+ uint64_t hist_index = spa_syncing_txg(spa) % TXG_DEFER_SIZE;
+ if (defer_allowed) {
+ bcopy(msp->ms_synchist, msp->ms_deferhist[hist_index],
+ sizeof (msp->ms_synchist));
+ } else {
+ bzero(msp->ms_deferhist[hist_index],
+ sizeof (msp->ms_deferhist[hist_index]));
+ }
+ bzero(msp->ms_synchist, sizeof (msp->ms_synchist));
}
-#define METASLAB_WEIGHT_PRIMARY (1ULL << 63)
-#define METASLAB_WEIGHT_SECONDARY (1ULL << 62)
-#define METASLAB_ACTIVE_MASK \
- (METASLAB_WEIGHT_PRIMARY | METASLAB_WEIGHT_SECONDARY)
-
-static uint64_t
-metaslab_weight(metaslab_t *msp)
+/*
+ * Ensure that the metaslab's weight and fragmentation are consistent
+ * with the contents of the histogram (either the range tree's histogram
+ * or the space map's depending whether the metaslab is loaded).
+ */
+static void
+metaslab_verify_weight_and_frag(metaslab_t *msp)
{
- metaslab_group_t *mg = msp->ms_group;
- space_map_t *sm = msp->ms_map;
- space_map_obj_t *smo = &msp->ms_smo;
- vdev_t *vd = mg->mg_vd;
- uint64_t weight, space;
-
ASSERT(MUTEX_HELD(&msp->ms_lock));
+ if ((zfs_flags & ZFS_DEBUG_METASLAB_VERIFY) == 0)
+ return;
+
+ /* see comment in metaslab_verify_unflushed_changes() */
+ if (msp->ms_group == NULL)
+ return;
+
/*
- * The baseline weight is the metaslab's free space.
+ * Devices being removed always return a weight of 0 and leave
+ * fragmentation and ms_max_size as is - there is nothing for
+ * us to verify here.
*/
- space = sm->sm_size - smo->smo_alloc;
+ vdev_t *vd = msp->ms_group->mg_vd;
+ if (vd->vdev_removing)
+ return;
+
+ /*
+ * If the metaslab is dirty it probably means that we've done
+ * some allocations or frees that have changed our histograms
+ * and thus the weight.
+ */
+ for (int t = 0; t < TXG_SIZE; t++) {
+ if (txg_list_member(&vd->vdev_ms_list, msp, t))
+ return;
+ }
+
+ /*
+ * This verification checks that our in-memory state is consistent
+ * with what's on disk. If the pool is read-only then there aren't
+ * any changes and we just have the initially-loaded state.
+ */
+ if (!spa_writeable(msp->ms_group->mg_vd->vdev_spa))
+ return;
+
+ /* some extra verification for in-core tree if you can */
+ if (msp->ms_loaded) {
+ range_tree_stat_verify(msp->ms_allocatable);
+ VERIFY(space_map_histogram_verify(msp->ms_sm,
+ msp->ms_allocatable));
+ }
+
+ uint64_t weight = msp->ms_weight;
+ uint64_t was_active = msp->ms_weight & METASLAB_ACTIVE_MASK;
+ boolean_t space_based = WEIGHT_IS_SPACEBASED(msp->ms_weight);
+ uint64_t frag = msp->ms_fragmentation;
+ uint64_t max_segsize = msp->ms_max_size;
+
+ msp->ms_weight = 0;
+ msp->ms_fragmentation = 0;
+ msp->ms_max_size = 0;
+
+ /*
+ * This function is used for verification purposes. Regardless of
+ * whether metaslab_weight() thinks this metaslab should be active or
+ * not, we want to ensure that the actual weight (and therefore the
+ * value of ms_weight) would be the same if it was to be recalculated
+ * at this point.
+ */
+ msp->ms_weight = metaslab_weight(msp) | was_active;
+
+ VERIFY3U(max_segsize, ==, msp->ms_max_size);
+
+ /*
+ * If the weight type changed then there is no point in doing
+ * verification. Revert fields to their original values.
+ */
+ if ((space_based && !WEIGHT_IS_SPACEBASED(msp->ms_weight)) ||
+ (!space_based && WEIGHT_IS_SPACEBASED(msp->ms_weight))) {
+ msp->ms_fragmentation = frag;
+ msp->ms_weight = weight;
+ return;
+ }
+
+ VERIFY3U(msp->ms_fragmentation, ==, frag);
+ VERIFY3U(msp->ms_weight, ==, weight);
+}
+
+/*
+ * Wait for any in-progress metaslab loads to complete.
+ */
+static 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);
+ }
+}
+
+static int
+metaslab_load_impl(metaslab_t *msp)
+{
+ int error = 0;
+
+ ASSERT(MUTEX_HELD(&msp->ms_lock));
+ ASSERT(msp->ms_loading);
+ ASSERT(!msp->ms_condensing);
+
+ /*
+ * We temporarily drop the lock to unblock other operations while we
+ * are reading the space map. Therefore, metaslab_sync() and
+ * metaslab_sync_done() can run at the same time as we do.
+ *
+ * metaslab_sync() can append to the space map while we are loading.
+ * Therefore we load only entries that existed when we started the
+ * load. Additionally, metaslab_sync_done() has to wait for the load
+ * to complete because there are potential races like metaslab_load()
+ * loading parts of the space map that are currently being appended
+ * by metaslab_sync(). If we didn't, the ms_allocatable would have
+ * entries that metaslab_sync_done() would try to re-add later.
+ *
+ * That's why before dropping the lock we remember the synced length
+ * of the metaslab and read up to that point of the space map,
+ * ignoring entries appended by metaslab_sync() that happen after we
+ * drop the lock.
+ */
+ uint64_t length = msp->ms_synced_length;
+ mutex_exit(&msp->ms_lock);
+
+ if (msp->ms_sm != NULL) {
+ error = space_map_load_length(msp->ms_sm, msp->ms_allocatable,
+ SM_FREE, length);
+ } else {
+ /*
+ * The space map has not been allocated yet, so treat
+ * all the space in the metaslab as free and add it to the
+ * ms_allocatable tree.
+ */
+ range_tree_add(msp->ms_allocatable,
+ msp->ms_start, msp->ms_size);
+ }
+
+ /*
+ * We need to grab the ms_sync_lock to prevent metaslab_sync() from
+ * changing the ms_sm and the metaslab's range trees while we are
+ * about to use them and populate the ms_allocatable. The ms_lock
+ * is insufficient for this because metaslab_sync() doesn't hold
+ * the ms_lock while writing the ms_checkpointing tree to disk.
+ */
+ mutex_enter(&msp->ms_sync_lock);
+ mutex_enter(&msp->ms_lock);
+ ASSERT(!msp->ms_condensing);
+
+ if (error != 0) {
+ mutex_exit(&msp->ms_sync_lock);
+ return (error);
+ }
+
+ ASSERT3P(msp->ms_group, !=, NULL);
+ msp->ms_loaded = B_TRUE;
+
+ /*
+ * The ms_allocatable contains the segments that exist in the
+ * ms_defer trees [see ms_synced_length]. Thus we need to remove
+ * them from ms_allocatable as they will be added again in
+ * metaslab_sync_done().
+ */
+ for (int t = 0; t < TXG_DEFER_SIZE; t++) {
+ range_tree_walk(msp->ms_defer[t],
+ range_tree_remove, msp->ms_allocatable);
+ }
+
+ /*
+ * Call metaslab_recalculate_weight_and_sort() now that the
+ * metaslab is loaded so we get the metaslab's real weight.
+ *
+ * Unless this metaslab was created with older software and
+ * has not yet been converted to use segment-based weight, we
+ * expect the new weight to be better or equal to the weight
+ * that the metaslab had while it was not loaded. This is
+ * because the old weight does not take into account the
+ * consolidation of adjacent segments between TXGs. [see
+ * comment for ms_synchist and ms_deferhist[] for more info]
+ */
+ uint64_t weight = msp->ms_weight;
+ metaslab_recalculate_weight_and_sort(msp);
+ if (!WEIGHT_IS_SPACEBASED(weight))
+ ASSERT3U(weight, <=, msp->ms_weight);
+ msp->ms_max_size = metaslab_block_maxsize(msp);
+
+ spa_t *spa = msp->ms_group->mg_vd->vdev_spa;
+ metaslab_verify_space(msp, spa_syncing_txg(spa));
+ mutex_exit(&msp->ms_sync_lock);
+
+ return (0);
+}
+
+int
+metaslab_load(metaslab_t *msp)
+{
+ ASSERT(MUTEX_HELD(&msp->ms_lock));
+
+ /*
+ * There may be another thread loading the same metaslab, if that's
+ * the case just wait until the other thread is done and return.
+ */
+ metaslab_load_wait(msp);
+ if (msp->ms_loaded)
+ return (0);
+ VERIFY(!msp->ms_loading);
+ ASSERT(!msp->ms_condensing);
+
+ msp->ms_loading = B_TRUE;
+ int error = metaslab_load_impl(msp);
+ msp->ms_loading = B_FALSE;
+ cv_broadcast(&msp->ms_load_cv);
+
+ return (error);
+}
+
+void
+metaslab_unload(metaslab_t *msp)
+{
+ ASSERT(MUTEX_HELD(&msp->ms_lock));
+
+ metaslab_verify_weight_and_frag(msp);
+
+ range_tree_vacate(msp->ms_allocatable, NULL, NULL);
+ msp->ms_loaded = B_FALSE;
+
+ msp->ms_weight &= ~METASLAB_ACTIVE_MASK;
+ msp->ms_max_size = 0;
+
+ /*
+ * We explicitly recalculate the metaslab's weight based on its space
+ * map (as it is now not loaded). We want unload metaslabs to always
+ * have their weights calculated from the space map histograms, while
+ * loaded ones have it calculated from their in-core range tree
+ * [see metaslab_load()]. This way, the weight reflects the information
+ * available in-core, whether it is loaded or not
+ *
+ * If ms_group == NULL means that we came here from metaslab_fini(),
+ * at which point it doesn't make sense for us to do the recalculation
+ * and the sorting.
+ */
+ if (msp->ms_group != NULL)
+ metaslab_recalculate_weight_and_sort(msp);
+}
+
+static void
+metaslab_space_update(vdev_t *vd, metaslab_class_t *mc, int64_t alloc_delta,
+ int64_t defer_delta, int64_t space_delta)
+{
+ vdev_space_update(vd, alloc_delta, defer_delta, space_delta);
+
+ ASSERT3P(vd->vdev_spa->spa_root_vdev, ==, vd->vdev_parent);
+ ASSERT(vd->vdev_ms_count != 0);
+
+ metaslab_class_space_update(mc, alloc_delta, defer_delta, space_delta,
+ vdev_deflated_space(vd, space_delta));
+}
+
+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;
+ spa_t *spa = vd->vdev_spa;
+ objset_t *mos = 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.
+ *
+ * Note:
+ * When called from vdev_expand(), we can't call into the DMU as
+ * we are holding the spa_config_lock as a writer and we would
+ * deadlock [see relevant comment in vdev_metaslab_init()]. in
+ * that case, the object parameter is zero though, so we won't
+ * call into the DMU.
+ */
+ 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);
+ ms->ms_allocated_space = space_map_allocated(ms->ms_sm);
+ }
+
+ /*
+ * We create the ms_allocatable 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);
+ metaslab_space_update(vd, mg->mg_class,
+ metaslab_allocated_space(ms), 0, 0);
+ }
+
+ /*
+ * If metaslab_debug_load is set and we're initializing a metaslab
+ * that has an allocated space map object then load the space map
+ * so that we 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;
+ vdev_t *vd = mg->mg_vd;
+
+ metaslab_group_remove(mg, msp);
+
+ mutex_enter(&msp->ms_lock);
+ VERIFY(msp->ms_group == NULL);
+ metaslab_space_update(vd, mg->mg_class,
+ -metaslab_allocated_space(msp), 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);
+
+ for (int t = 0; t < TXG_SIZE; t++)
+ ASSERT(!txg_list_member(&vd->vdev_ms_list, msp, t));
+
+ 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 fragmentation 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 */
+};
+
+/*
+ * Calculate the metaslab's fragmentation metric and set ms_fragmentation.
+ * Setting this value to 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 - metaslab_allocated_space(msp);
+
+ 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;
/*
* 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.
*/
- weight = 2 * weight -
- ((sm->sm_start >> vd->vdev_ms_shift) * weight) / vd->vdev_ms_count;
- ASSERT(weight >= space && weight <= 2 * 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);
+ }
/*
- * For locality, assign higher weight to metaslabs which have
- * a lower offset than what we've already activated.
+ * 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 (sm->sm_start <= mg->mg_bonus_area)
- weight *= (metaslab_smo_bonus_pct / 100);
- ASSERT(weight >= space &&
- weight <= 2 * (metaslab_smo_bonus_pct / 100) * space);
+ 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];
- if (sm->sm_loaded && !sm->sm_ops->smop_fragmented(sm)) {
/*
- * 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.
+ * 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".
*/
- weight |= (msp->ms_weight & METASLAB_ACTIVE_MASK);
+ 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);
}
-static void
-metaslab_prefetch(metaslab_group_t *mg)
+/*
+ * 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)
{
- spa_t *spa = mg->mg_vd->vdev_spa;
- metaslab_t *msp;
- avl_tree_t *t = &mg->mg_metaslab_tree;
- int m;
-
- mutex_enter(&mg->mg_lock);
+ space_map_t *sm = msp->ms_sm;
+ ASSERT(!msp->ms_loaded);
+ ASSERT(sm != NULL);
+ ASSERT3U(space_map_object(sm), !=, 0);
+ ASSERT3U(sm->sm_dbuf->db_size, ==, sizeof (space_map_phys_t));
/*
- * Prefetch the next potential metaslabs
+ * Create a joint histogram from all the segments that have made
+ * it to the metaslab's space map histogram, that are not yet
+ * available for allocation because they are still in the freeing
+ * pipeline (e.g. freeing, freed, and defer trees). Then subtract
+ * these segments from the space map's histogram to get a more
+ * accurate weight.
*/
- for (msp = avl_first(t), m = 0; msp; msp = AVL_NEXT(t, msp), m++) {
- space_map_t *sm = msp->ms_map;
- space_map_obj_t *smo = &msp->ms_smo;
+ uint64_t deferspace_histogram[SPACE_MAP_HISTOGRAM_SIZE] = {0};
+ for (int i = 0; i < SPACE_MAP_HISTOGRAM_SIZE; i++)
+ deferspace_histogram[i] += msp->ms_synchist[i];
+ for (int t = 0; t < TXG_DEFER_SIZE; t++) {
+ for (int i = 0; i < SPACE_MAP_HISTOGRAM_SIZE; i++) {
+ deferspace_histogram[i] += msp->ms_deferhist[t][i];
+ }
+ }
- /* If we have reached our prefetch limit then we're done */
- if (m >= metaslab_prefetch_limit)
+ uint64_t weight = 0;
+ for (int i = SPACE_MAP_HISTOGRAM_SIZE - 1; i >= 0; i--) {
+ ASSERT3U(sm->sm_phys->smp_histogram[i], >=,
+ deferspace_histogram[i]);
+ uint64_t count =
+ sm->sm_phys->smp_histogram[i] - deferspace_histogram[i];
+ if (count != 0) {
+ WEIGHT_SET_COUNT(weight, count);
+ WEIGHT_SET_INDEX(weight, i + sm->sm_shift);
+ WEIGHT_SET_ACTIVE(weight, 0);
break;
+ }
+ }
+ return (weight);
+}
- if (!sm->sm_loaded && smo->smo_object != 0) {
- mutex_exit(&mg->mg_lock);
- dmu_prefetch(spa_meta_objset(spa), smo->smo_object,
- 0ULL, smo->smo_objsize);
- mutex_enter(&mg->mg_lock);
+/*
+ * 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 (metaslab_allocated_space(msp) == 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);
}
- mutex_exit(&mg->mg_lock);
+
+ 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 (metaslab_allocated_space(msp) == 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);
+ else
+ ASSERT0(msp->ms_max_size);
+
+ /*
+ * 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);
+}
+
+void
+metaslab_recalculate_weight_and_sort(metaslab_t *msp)
+{
+ /* note: we preserve the mask (e.g. indication of primary, etc..) */
+ uint64_t was_active = msp->ms_weight & METASLAB_ACTIVE_MASK;
+ metaslab_group_sort(msp->ms_group, msp,
+ metaslab_weight(msp) | was_active);
}
static int
-metaslab_activate(metaslab_t *msp, uint64_t activation_weight)
+metaslab_activate_allocator(metaslab_group_t *mg, metaslab_t *msp,
+ int allocator, uint64_t activation_weight)
{
- metaslab_group_t *mg = msp->ms_group;
- space_map_t *sm = msp->ms_map;
- space_map_ops_t *sm_ops = msp->ms_group->mg_class->mc_ops;
- int t;
+ /*
+ * 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);
+ }
- if ((msp->ms_weight & METASLAB_ACTIVE_MASK) == 0) {
- space_map_load_wait(sm);
- if (!sm->sm_loaded) {
- space_map_obj_t *smo = &msp->ms_smo;
-
- int error = space_map_load(sm, sm_ops, SM_FREE, smo,
- spa_meta_objset(msp->ms_group->mg_vd->vdev_spa));
- if (error) {
- metaslab_group_sort(msp->ms_group, msp, 0);
- return (error);
- }
- for (t = 0; t < TXG_DEFER_SIZE; t++)
- space_map_walk(msp->ms_defermap[t],
- space_map_claim, sm);
+ 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 = metaslab_load(msp);
+ if (error != 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 (SET_ERROR(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)
+{
+ ASSERTV(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(!WEIGHT_IS_SPACEBASED(msp->ms_weight) ||
+ size >= SPA_MINBLOCKSIZE ||
+ range_tree_space(msp->ms_allocatable) == 0);
+ 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
+ * metaslab with a 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;
+ fstrans_cookie_t cookie = spl_fstrans_mark();
+
+ ASSERT(!MUTEX_HELD(&msp->ms_group->mg_lock));
+
+ mutex_enter(&msp->ms_lock);
+ (void) metaslab_load(msp);
+ msp->ms_selected_txg = spa_syncing_txg(spa);
+ mutex_exit(&msp->ms_lock);
+ spl_fstrans_unmark(cookie);
+}
+
+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_outstanding(mg->mg_taskq, 0);
+ 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);
/*
- * Track the bonus area as we activate new metaslabs.
+ * 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 (sm->sm_start > mg->mg_bonus_area) {
- mutex_enter(&mg->mg_lock);
- mg->mg_bonus_area = sm->sm_start;
- mutex_exit(&mg->mg_lock);
+ if (++m > metaslab_preload_limit && !msp->ms_condense_wanted) {
+ continue;
}
- metaslab_group_sort(msp->ms_group, msp,
- msp->ms_weight | activation_weight);
+ VERIFY(taskq_dispatch(mg->mg_taskq, metaslab_preload,
+ msp, TQ_SLEEP) != TASKQID_INVALID);
}
- ASSERT(sm->sm_loaded);
- ASSERT(msp->ms_weight & METASLAB_ACTIVE_MASK);
-
- return (0);
-}
-
-static void
-metaslab_passivate(metaslab_t *msp, uint64_t size)
-{
- /*
- * 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 || msp->ms_map->sm_space == 0);
- metaslab_group_sort(msp->ms_group, msp, MIN(msp->ms_weight, size));
- ASSERT((msp->ms_weight & METASLAB_ACTIVE_MASK) == 0);
+ mutex_exit(&mg->mg_lock);
}
/*
- * Determine if the in-core space map representation can be condensed on-disk.
- * We would like to use the following criteria to make our decision:
+ * 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 our in-core free map.
+ * 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 in-core representation (i.e. zfs_condense_pct = 110
- * and in-core = 1MB, minimal = 1.1.MB).
+ * times the size than the free space range tree representation
+ * (i.e. zfs_condense_pct = 110 and in-core = 1MB, minimal = 1.1MB).
*
- * Checking the first condition is tricky since we don't want to walk
- * the entire AVL tree calculating the estimated on-disk size. Instead we
- * use the size-ordered AVL tree in the space map and calculate the
- * size required for the largest segment in our in-core free map. If the
- * size required to represent that segment on disk is larger than the space
- * map object then we avoid condensing this map.
+ * 3. The on-disk size of the space map should actually decrease.
*
- * To determine the second criterion we use a best-case estimate and assume
- * each segment can be represented on-disk as a single 64-bit entry. We refer
- * to this best-case estimate as the space map's minimal form.
+ * 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_map;
- space_map_obj_t *smo = &msp->ms_smo_syncing;
- space_seg_t *ss;
- uint64_t size, entries, segsz;
+ 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(sm->sm_loaded);
+ ASSERT(msp->ms_loaded);
/*
- * Use the sm_pp_root AVL tree, which is ordered by size, to obtain
- * the largest segment in the in-core free map. If the tree is
- * empty then we should condense the map.
+ * 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.
*/
- ss = avl_last(sm->sm_pp_root);
- if (ss == NULL)
- return (B_TRUE);
+ if (msp->ms_condense_checked_txg == current_txg)
+ return (B_FALSE);
+ msp->ms_condense_checked_txg = current_txg;
/*
- * Calculate the number of 64-bit entries this segment would
- * require when written to disk. If this single segment would be
- * larger on-disk than the entire current on-disk structure, then
- * clearly condensing will increase the on-disk structure size.
+ * We always condense metaslabs that are empty and metaslabs for
+ * which a condense request has been made.
*/
- size = (ss->ss_end - ss->ss_start) >> sm->sm_shift;
- entries = size / (MIN(size, SM_RUN_MAX));
- segsz = entries * sizeof (uint64_t);
+ 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 (segsz <= smo->smo_objsize &&
- smo->smo_objsize >= (zfs_condense_pct *
- sizeof (uint64_t) * avl_numnodes(&sm->sm_root)) / 100);
+ 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 in-core free map.
+ * the entries of the free range tree.
*/
static void
metaslab_condense(metaslab_t *msp, uint64_t txg, dmu_tx_t *tx)
{
- spa_t *spa = msp->ms_group->mg_vd->vdev_spa;
- space_map_t *freemap = msp->ms_freemap[txg & TXG_MASK];
- space_map_t condense_map;
- space_map_t *sm = msp->ms_map;
- objset_t *mos = spa_meta_objset(spa);
- space_map_obj_t *smo = &msp->ms_smo_syncing;
- int t;
+ range_tree_t *condense_tree;
+ space_map_t *sm = msp->ms_sm;
ASSERT(MUTEX_HELD(&msp->ms_lock));
- ASSERT3U(spa_sync_pass(spa), ==, 1);
- ASSERT(sm->sm_loaded);
+ 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");
- spa_dbgmsg(spa, "condensing: txg %llu, msp[%llu] %p, "
- "smo size %llu, segments %lu", txg,
- (msp->ms_map->sm_start / msp->ms_map->sm_size), msp,
- smo->smo_objsize, avl_numnodes(&sm->sm_root));
+ msp->ms_condense_wanted = B_FALSE;
/*
- * Create an map that is a 100% allocated map. We remove segments
+ * 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 maps to
- * a small number of nodes.
+ * a relatively inexpensive operation since we expect these trees to
+ * have a small number of nodes.
*/
- space_map_create(&condense_map, sm->sm_start, sm->sm_size,
- sm->sm_shift, sm->sm_lock);
- space_map_add(&condense_map, condense_map.sm_start,
- condense_map.sm_size);
+ condense_tree = range_tree_create(NULL, NULL);
+ range_tree_add(condense_tree, msp->ms_start, msp->ms_size);
- /*
- * Remove what's been freed in this txg from the condense_map.
- * Since we're in sync_pass 1, we know that all the frees from
- * this txg are in the freemap.
- */
- space_map_walk(freemap, space_map_remove, &condense_map);
+ range_tree_walk(msp->ms_freeing, range_tree_remove, condense_tree);
+ range_tree_walk(msp->ms_freed, range_tree_remove, condense_tree);
- for (t = 0; t < TXG_DEFER_SIZE; t++)
- space_map_walk(msp->ms_defermap[t],
- space_map_remove, &condense_map);
+ for (int t = 0; t < TXG_DEFER_SIZE; t++) {
+ range_tree_walk(msp->ms_defer[t],
+ range_tree_remove, condense_tree);
+ }
- for (t = 1; t < TXG_CONCURRENT_STATES; t++)
- space_map_walk(msp->ms_allocmap[(txg + t) & TXG_MASK],
- space_map_remove, &condense_map);
+ 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
- * space_map's sm_condensing flag to ensure that
+ * 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 the ms_map as all other space_maps use per txg
+ * for ms_allocatable as all other range trees use per txg
* views of their content.
*/
- sm->sm_condensing = B_TRUE;
+ msp->ms_condensing = B_TRUE;
mutex_exit(&msp->ms_lock);
- space_map_truncate(smo, mos, tx);
- mutex_enter(&msp->ms_lock);
+ space_map_truncate(sm, zfs_metaslab_sm_blksz, tx);
/*
- * While we would ideally like to create a space_map representation
+ * 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 map can be
+ * prohibitively expensive because the in-core free tree can be
* large, and therefore computationally expensive to subtract
- * from the condense_map. Instead we sync out two maps, a cheap
- * allocation only map followed by the in-core free map. While not
+ * 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_sync(&condense_map, SM_ALLOC, smo, mos, tx);
- space_map_vacate(&condense_map, NULL, NULL);
- space_map_destroy(&condense_map);
-
- space_map_sync(sm, SM_FREE, smo, mos, tx);
- sm->sm_condensing = B_FALSE;
+ space_map_write(sm, condense_tree, SM_ALLOC, SM_NO_VDEVID, tx);
+ range_tree_vacate(condense_tree, NULL, NULL);
+ range_tree_destroy(condense_tree);
- spa_dbgmsg(spa, "condensed: txg %llu, msp[%llu] %p, "
- "smo size %llu", txg,
- (msp->ms_map->sm_start / msp->ms_map->sm_size), msp,
- smo->smo_objsize);
+ space_map_write(sm, msp->ms_allocatable, SM_FREE, SM_NO_VDEVID, tx);
+ mutex_enter(&msp->ms_lock);
+ msp->ms_condensing = B_FALSE;
}
/*
void
metaslab_sync(metaslab_t *msp, uint64_t txg)
{
- vdev_t *vd = msp->ms_group->mg_vd;
+ 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);
- space_map_t *allocmap = msp->ms_allocmap[txg & TXG_MASK];
- space_map_t **freemap = &msp->ms_freemap[txg & TXG_MASK];
- space_map_t **freed_map = &msp->ms_freemap[TXG_CLEAN(txg) & TXG_MASK];
- space_map_t *sm = msp->ms_map;
- space_map_obj_t *smo = &msp->ms_smo_syncing;
- dmu_buf_t *db;
+ 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 (*freemap == NULL) {
- ASSERT3P(allocmap, ==, NULL);
+ if (msp->ms_freeing == NULL) {
+ ASSERT3P(alloctree, ==, NULL);
return;
}
- ASSERT3P(allocmap, !=, NULL);
- ASSERT3P(*freemap, !=, NULL);
- ASSERT3P(*freed_map, !=, NULL);
+ ASSERT3P(alloctree, !=, NULL);
+ ASSERT3P(msp->ms_freeing, !=, NULL);
+ ASSERT3P(msp->ms_freed, !=, NULL);
+ ASSERT3P(msp->ms_checkpointing, !=, NULL);
- if (allocmap->sm_space == 0 && (*freemap)->sm_space == 0)
+ /*
+ * 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_map. No other thread can
- * be modifying this txg's allocmap, freemap, freed_map, or smo.
- * Therefore, we only hold ms_lock to satify space_map ASSERTs.
- * We drop it whenever we call into the DMU, because the DMU
- * can call down to us (e.g. via zio_free()) at any time.
+ * 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 (smo->smo_object == 0) {
- ASSERT(smo->smo_objsize == 0);
- ASSERT(smo->smo_alloc == 0);
- smo->smo_object = dmu_object_alloc(mos,
- DMU_OT_SPACE_MAP, 1 << SPACE_MAP_BLOCKSHIFT,
- DMU_OT_SPACE_MAP_HEADER, sizeof (*smo), tx);
- ASSERT(smo->smo_object != 0);
- dmu_write(mos, vd->vdev_ms_array, sizeof (uint64_t) *
- (sm->sm_start >> vd->vdev_ms_shift),
- sizeof (uint64_t), &smo->smo_object, tx);
+ 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);
+ ASSERT0(metaslab_allocated_space(msp));
}
+ 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);
- if (sm->sm_loaded && spa_sync_pass(spa) == 1 &&
- metaslab_should_condense(msp)) {
+ /*
+ * 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 {
- space_map_sync(allocmap, SM_ALLOC, smo, mos, tx);
- space_map_sync(*freemap, SM_FREE, smo, mos, tx);
+ 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);
+ }
+
+ msp->ms_allocated_space += range_tree_space(alloctree);
+ ASSERT3U(msp->ms_allocated_space, >=,
+ range_tree_space(msp->ms_freeing));
+ msp->ms_allocated_space -= range_tree_space(msp->ms_freeing);
+
+ 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);
+
+ 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, ==,
+ -space_map_allocated(vd->vdev_checkpoint_sm));
+
+ 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);
+ }
}
- space_map_vacate(allocmap, NULL, NULL);
+ /*
+ * 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_aux_histograms_update(msp);
+
+ metaslab_group_histogram_add(mg, msp);
+ metaslab_group_histogram_verify(mg);
+ metaslab_class_histogram_verify(mg->mg_class);
/*
- * For sync pass 1, we avoid walking the entire space map and
- * instead will just swap the pointers for freemap and
- * freed_map. We can safely do this since the freed_map is
- * guaranteed to be empty on the initial pass.
+ * 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) {
- ASSERT0((*freed_map)->sm_space);
- ASSERT0(avl_numnodes(&(*freed_map)->sm_root));
- space_map_swap(freemap, freed_map);
+ range_tree_swap(&msp->ms_freeing, &msp->ms_freed);
+ ASSERT0(msp->ms_allocated_this_txg);
} else {
- space_map_vacate(*freemap, space_map_add, *freed_map);
+ range_tree_vacate(msp->ms_freeing,
+ range_tree_add, msp->ms_freed);
}
+ msp->ms_allocated_this_txg += range_tree_space(alloctree);
+ range_tree_vacate(alloctree, NULL, NULL);
- ASSERT0(msp->ms_allocmap[txg & TXG_MASK]->sm_space);
- ASSERT0(msp->ms_freemap[txg & TXG_MASK]->sm_space);
+ 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);
- VERIFY0(dmu_bonus_hold(mos, smo->smo_object, FTAG, &db));
- dmu_buf_will_dirty(db, tx);
- ASSERT3U(db->db_size, >=, sizeof (*smo));
- bcopy(smo, db->db_data, sizeof (*smo));
- dmu_buf_rele(db, FTAG);
-
+ 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);
}
void
metaslab_sync_done(metaslab_t *msp, uint64_t txg)
{
- space_map_obj_t *smo = &msp->ms_smo;
- space_map_obj_t *smosync = &msp->ms_smo_syncing;
- space_map_t *sm = msp->ms_map;
- space_map_t *freed_map = msp->ms_freemap[TXG_CLEAN(txg) & TXG_MASK];
- space_map_t *defer_map = msp->ms_defermap[txg % TXG_DEFER_SIZE];
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;
- int t;
+ boolean_t defer_allowed = B_TRUE;
ASSERT(!vd->vdev_ishole);
mutex_enter(&msp->ms_lock);
- /*
- * If this metaslab is just becoming available, initialize its
- * allocmaps, freemaps, and defermap and add its capacity to the vdev.
- */
- if (freed_map == NULL) {
- ASSERT(defer_map == NULL);
- for (t = 0; t < TXG_SIZE; t++) {
- msp->ms_allocmap[t] = kmem_zalloc(sizeof (space_map_t),
- KM_PUSHPAGE);
- space_map_create(msp->ms_allocmap[t], sm->sm_start,
- sm->sm_size, sm->sm_shift, sm->sm_lock);
- msp->ms_freemap[t] = kmem_zalloc(sizeof (space_map_t),
- KM_PUSHPAGE);
- space_map_create(msp->ms_freemap[t], sm->sm_start,
- sm->sm_size, sm->sm_shift, sm->sm_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);
+
+ metaslab_space_update(vd, mg->mg_class, 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 = msp->ms_allocated_this_txg -
+ range_tree_space(msp->ms_freed);
+ if (defer_allowed) {
+ defer_delta = range_tree_space(msp->ms_freed) -
+ range_tree_space(*defer_tree);
+ } else {
+ defer_delta -= range_tree_space(*defer_tree);
+ }
+
+ metaslab_space_update(vd, mg->mg_class, 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);
+ }
+
+ msp->ms_synced_length = space_map_length(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);
+ }
+ metaslab_aux_histograms_update_done(msp, defer_allowed);
+
+ if (msp->ms_new) {
+ msp->ms_new = B_FALSE;
+ mutex_enter(&mg->mg_lock);
+ mg->mg_ms_ready++;
+ mutex_exit(&mg->mg_lock);
+ }
+
+ /*
+ * Re-sort metaslab within its group now that we've adjusted
+ * its allocatable space.
+ */
+ metaslab_recalculate_weight_and_sort(msp);
+
+ /*
+ * 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));
+
+ msp->ms_allocated_this_txg = 0;
+ 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);
+}
+
+/*
+ * When writing 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
+ * on a different metaslab than existing DVAs (i.e. a unique metaslab).
+ */
+static boolean_t
+metaslab_is_unique(metaslab_t *msp, dva_t *dva)
+{
+ uint64_t dva_ms_id;
+
+ if (DVA_GET_ASIZE(dva) == 0)
+ return (B_TRUE);
+
+ if (msp->ms_group->mg_vd->vdev_id != DVA_GET_VDEV(dva))
+ return (B_TRUE);
+
+ dva_ms_id = DVA_GET_OFFSET(dva) >> msp->ms_group->mg_vd->vdev_ms_shift;
+
+ return (msp->ms_id != dva_ms_id);
+}
+
+/*
+ * ==========================================================================
+ * Metaslab allocation tracing facility
+ * ==========================================================================
+ */
+#ifdef _METASLAB_TRACING
+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)
+{
+ metaslab_alloc_trace_t *mat;
+
+ 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);
+ }
+
+ 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;
+}
+#else
+
+#define metaslab_trace_add(zal, mg, msp, psize, id, off, alloc)
+
+void
+metaslab_alloc_trace_init(void)
+{
+}
+
+void
+metaslab_alloc_trace_fini(void)
+{
+}
+
+void
+metaslab_trace_init(zio_alloc_list_t *zal)
+{
+}
+
+void
+metaslab_trace_fini(zio_alloc_list_t *zal)
+{
+}
+
+#endif /* _METASLAB_TRACING */
+
+/*
+ * ==========================================================================
+ * 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) zfs_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;
- for (t = 0; t < TXG_DEFER_SIZE; t++) {
- msp->ms_defermap[t] = kmem_zalloc(sizeof (space_map_t),
- KM_PUSHPAGE);
- space_map_create(msp->ms_defermap[t], sm->sm_start,
- sm->sm_size, sm->sm_shift, sm->sm_lock);
- }
+ (void) zfs_refcount_remove(&mg->mg_alloc_queue_depth[allocator], tag);
+ if (io_complete)
+ metaslab_group_increment_qdepth(mg, allocator);
+}
- freed_map = msp->ms_freemap[TXG_CLEAN(txg) & TXG_MASK];
- defer_map = msp->ms_defermap[txg % TXG_DEFER_SIZE];
+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);
- vdev_space_update(vd, 0, 0, sm->sm_size);
+ 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(zfs_refcount_not_held(
+ &mg->mg_alloc_queue_depth[allocator], tag));
}
+#endif
+}
- alloc_delta = smosync->smo_alloc - smo->smo_alloc;
- defer_delta = freed_map->sm_space - defer_map->sm_space;
+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;
- vdev_space_update(vd, alloc_delta + defer_delta, defer_delta, 0);
+ VERIFY(!msp->ms_condensing);
+ VERIFY0(msp->ms_initializing);
- ASSERT(msp->ms_allocmap[txg & TXG_MASK]->sm_space == 0);
- ASSERT(msp->ms_freemap[txg & TXG_MASK]->sm_space == 0);
+ start = mc->mc_ops->msop_alloc(msp, size);
+ if (start != -1ULL) {
+ metaslab_group_t *mg = msp->ms_group;
+ vdev_t *vd = mg->mg_vd;
- /*
- * If there's a space_map_load() in progress, wait for it to complete
- * so that we have a consistent view of the in-core space map.
- * Then, add defer_map (oldest deferred frees) to this map and
- * transfer freed_map (this txg's frees) to defer_map.
- */
- space_map_load_wait(sm);
- space_map_vacate(defer_map, sm->sm_loaded ? space_map_free : NULL, sm);
- space_map_vacate(freed_map, space_map_add, defer_map);
+ 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);
- *smo = *smosync;
+ if (range_tree_is_empty(msp->ms_allocating[txg & TXG_MASK]))
+ vdev_dirty(mg->mg_vd, VDD_METASLAB, msp, txg);
- msp->ms_deferspace += defer_delta;
- ASSERT3S(msp->ms_deferspace, >=, 0);
- ASSERT3S(msp->ms_deferspace, <=, sm->sm_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);
+ 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);
}
/*
- * If the map is loaded but no longer active, evict it as soon as all
- * future allocations have synced. (If we unloaded it now and then
- * loaded a moment later, the map wouldn't reflect those allocations.)
+ * Now that we've attempted the allocation we need to update the
+ * metaslab's maximum block size since it may have changed.
*/
- if (sm->sm_loaded && (msp->ms_weight & METASLAB_ACTIVE_MASK) == 0) {
- int evictable = 1;
-
- for (t = 1; t < TXG_CONCURRENT_STATES; t++)
- if (msp->ms_allocmap[(txg + t) & TXG_MASK]->sm_space)
- evictable = 0;
-
- if (evictable && !metaslab_debug)
- space_map_unload(sm);
- }
-
- metaslab_group_sort(mg, msp, metaslab_weight(msp));
-
- mutex_exit(&msp->ms_lock);
+ msp->ms_max_size = metaslab_block_maxsize(msp);
+ return (start);
}
-void
-metaslab_sync_reassess(metaslab_group_t *mg)
+/*
+ * 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, boolean_t want_unique, uint64_t asize, int allocator,
+ zio_alloc_list_t *zal, metaslab_t *search, boolean_t *was_active)
{
- vdev_t *vd = mg->mg_vd;
- int64_t failures = mg->mg_alloc_failures;
- int m;
+ 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;
+ }
- /*
- * Re-evaluate all metaslabs which have lower offsets than the
- * bonus area.
- */
- for (m = 0; m < vd->vdev_ms_count; m++) {
- metaslab_t *msp = vd->vdev_ms[m];
+ /*
+ * If the selected metaslab is condensing or being
+ * initialized, skip it.
+ */
+ if (msp->ms_condensing || msp->ms_initializing > 0)
+ continue;
- if (msp->ms_map->sm_start > mg->mg_bonus_area)
+ *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;
- mutex_enter(&msp->ms_lock);
- metaslab_group_sort(mg, msp, metaslab_weight(msp));
- mutex_exit(&msp->ms_lock);
+ for (i = 0; i < d; i++) {
+ if (want_unique &&
+ !metaslab_is_unique(msp, &dva[i]))
+ break; /* try another metaslab */
+ }
+ if (i == d)
+ break;
}
- atomic_add_64(&mg->mg_alloc_failures, -failures);
-
- /*
- * Prefetch the next potential metaslabs
- */
- metaslab_prefetch(mg);
-}
-
-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_map->sm_start >> ms_shift;
-
- 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);
+ 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(metaslab_group_t *mg, uint64_t psize, uint64_t asize,
- uint64_t txg, uint64_t min_distance, dva_t *dva, int d, int flags)
+metaslab_group_alloc_normal(metaslab_group_t *mg, zio_alloc_list_t *zal,
+ uint64_t asize, uint64_t txg, boolean_t want_unique, dva_t *dva,
+ int d, int allocator)
{
- spa_t *spa = mg->mg_vd->vdev_spa;
metaslab_t *msp = NULL;
uint64_t offset = -1ULL;
- avl_tree_t *t = &mg->mg_metaslab_tree;
uint64_t activation_weight;
- uint64_t target_distance;
- int i;
activation_weight = METASLAB_WEIGHT_PRIMARY;
- for (i = 0; i < d; i++) {
- if (DVA_GET_VDEV(&dva[i]) == mg->mg_vd->vdev_id) {
+ 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;
+ boolean_t was_active = B_FALSE;
mutex_enter(&mg->mg_lock);
- for (msp = avl_first(t); msp; msp = AVL_NEXT(t, msp)) {
- if (msp->ms_weight < asize) {
- spa_dbgmsg(spa, "%s: failed to meet weight "
- "requirement: vdev %llu, txg %llu, mg %p, "
- "msp %p, psize %llu, asize %llu, "
- "failures %llu, weight %llu",
- spa_name(spa), mg->mg_vd->vdev_id, txg,
- mg, msp, psize, asize,
- mg->mg_alloc_failures, msp->ms_weight);
- mutex_exit(&mg->mg_lock);
- return (-1ULL);
- }
- /*
- * If the selected metaslab is condensing, skip it.
- */
- if (msp->ms_map->sm_condensing)
- continue;
-
- was_active = msp->ms_weight & METASLAB_ACTIVE_MASK;
- if (activation_weight == METASLAB_WEIGHT_PRIMARY)
- break;
-
- target_distance = min_distance +
- (msp->ms_smo.smo_alloc ? 0 : min_distance >> 1);
-
- for (i = 0; i < d; i++)
- if (metaslab_distance(msp, &dva[i]) <
- target_distance)
- break;
- if (i == d)
- break;
+ 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,
+ want_unique, asize, allocator, zal, search,
+ &was_active);
}
- mutex_exit(&mg->mg_lock);
- if (msp == NULL)
- return (-1ULL);
- /*
- * If we've already reached the allowable number of failed
- * allocation attempts on this metaslab group then we
- * consider skipping it. We skip it only if we're allowed
- * to "fast" gang, the physical size is larger than
- * a gang block, and we're attempting to allocate from
- * the primary metaslab.
- */
- if (mg->mg_alloc_failures > zfs_mg_alloc_failures &&
- CAN_FASTGANG(flags) && psize > SPA_GANGBLOCKSIZE &&
- activation_weight == METASLAB_WEIGHT_PRIMARY) {
- spa_dbgmsg(spa, "%s: skipping metaslab group: "
- "vdev %llu, txg %llu, mg %p, psize %llu, "
- "asize %llu, failures %llu", spa_name(spa),
- mg->mg_vd->vdev_id, txg, mg, psize, asize,
- mg->mg_alloc_failures);
+ 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.
+ * were blocked on the metaslab lock. We check the
+ * active status first to see if we need to reselect
+ * a new metaslab.
*/
- if (msp->ms_weight < asize || (was_active &&
- !(msp->ms_weight & METASLAB_ACTIVE_MASK) &&
- activation_weight == METASLAB_WEIGHT_PRIMARY)) {
+ if (was_active && !(msp->ms_weight & METASLAB_ACTIVE_MASK)) {
mutex_exit(&msp->ms_lock);
continue;
}
- if ((msp->ms_weight & METASLAB_WEIGHT_SECONDARY) &&
- activation_weight == METASLAB_WEIGHT_PRIMARY) {
- metaslab_passivate(msp,
- msp->ms_weight & ~METASLAB_ACTIVE_MASK);
+ /*
+ * 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, activation_weight) != 0) {
+ 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.
+ * 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_map->sm_condensing) {
+ 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;
}
- if ((offset = space_map_alloc(msp->ms_map, asize)) != -1ULL)
+ 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);
- atomic_inc_64(&mg->mg_alloc_failures);
+ /*
+ * 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));
+ }
- metaslab_passivate(msp, space_map_maxsize(msp->ms_map));
+ /*
+ * 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);
+}
- if (msp->ms_allocmap[txg & TXG_MASK]->sm_space == 0)
- vdev_dirty(mg->mg_vd, VDD_METASLAB, msp, txg);
-
- space_map_add(msp->ms_allocmap[txg & TXG_MASK], offset, asize);
+static uint64_t
+metaslab_group_alloc(metaslab_group_t *mg, zio_alloc_list_t *zal,
+ uint64_t asize, uint64_t txg, boolean_t want_unique, dva_t *dva,
+ int d, int allocator)
+{
+ uint64_t offset;
+ ASSERT(mg->mg_initialized);
- mutex_exit(&msp->ms_lock);
+ offset = metaslab_group_alloc_normal(mg, zal, asize, txg, want_unique,
+ 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);
}
/*
* Allocate a block for the specified i/o.
*/
-static int
+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)
+ dva_t *dva, int d, dva_t *hintdva, uint64_t txg, int flags,
+ zio_alloc_list_t *zal, int allocator)
{
metaslab_group_t *mg, *fast_mg, *rotor;
vdev_t *vd;
- int dshift = 3;
- int all_zero;
- int zio_lock = B_FALSE;
- boolean_t allocatable;
- uint64_t offset = -1ULL;
- uint64_t asize;
- uint64_t distance;
+ boolean_t try_hard = B_FALSE;
ASSERT(!DVA_IS_VALID(&dva[d]));
/*
* For testing, make some blocks above a certain size be gang blocks.
+ * This will result in more split blocks when using device removal,
+ * and a large number of split blocks coupled with ztest-induced
+ * damage can result in extremely long reconstruction times. This
+ * will also test spilling from special to normal.
*/
- if (psize >= metaslab_gang_bang && (ddi_get_lbolt() & 3) == 0)
- return (ENOSPC);
-
- if (flags & METASLAB_FASTWRITE)
- mutex_enter(&mc->mc_fastwrite_lock);
+ if (psize >= metaslab_force_ganging && (spa_get_random(100) < 3)) {
+ 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.
/*
* It's possible the vdev we're using as the hint no
- * longer exists (i.e. removed). Consult the rotor when
+ * longer exists or its mg has been closed (e.g. by
+ * device removal). Consult the rotor when
* all else fails.
*/
- if (vd != NULL) {
+ if (vd != NULL && vd->vdev_mg != NULL) {
mg = vd->vdev_mg;
if (flags & METASLAB_HINTBP_AVOID &&
} while ((fast_mg = fast_mg->mg_next) != mc->mc_rotor);
} else {
+ ASSERT(mc->mc_rotor != NULL);
mg = mc->mc_rotor;
}
rotor = mg;
top:
- all_zero = B_TRUE;
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);
+
+ uint64_t asize = vdev_psize_to_asize(vd, psize);
+ ASSERT(P2PHASE(asize, 1ULL << vd->vdev_ashift) == 0);
+
+ /*
+ * If we don't need to try hard, then require that the
+ * block be on an different metaslab from any other DVAs
+ * in this BP (unique=true). If we are trying hard, then
+ * allow any metaslab to be used (unique=false).
+ */
+ uint64_t offset = metaslab_group_alloc(mg, zal, asize, txg,
+ !try_hard, 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.
+ *
+ * Bias is also used to compensate for unequally
+ * sized vdevs so that space is allocated fairly.
+ */
+ if (mc->mc_aliquot == 0 && metaslab_bias_enabled) {
+ vdev_stat_t *vs = &vd->vdev_stat;
+ int64_t vs_free = vs->vs_space - vs->vs_alloc;
+ int64_t mc_free = mc->mc_space - mc->mc_alloc;
+ int64_t ratio;
+
+ /*
+ * Calculate how much more or less we should
+ * try to allocate from this device during
+ * this iteration around the rotor.
+ *
+ * This basically introduces a zero-centered
+ * bias towards the devices with the most
+ * free space, while compensating for vdev
+ * size differences.
+ *
+ * Examples:
+ * vdev V1 = 16M/128M
+ * vdev V2 = 16M/128M
+ * ratio(V1) = 100% ratio(V2) = 100%
+ *
+ * vdev V1 = 16M/128M
+ * vdev V2 = 64M/128M
+ * ratio(V1) = 127% ratio(V2) = 72%
+ *
+ * vdev V1 = 16M/128M
+ * vdev V2 = 64M/512M
+ * ratio(V1) = 40% ratio(V2) = 160%
+ */
+ ratio = (vs_free * mc->mc_alloc_groups * 100) /
+ (mc_free + 1);
+ mg->mg_bias = ((ratio - 100) *
+ (int64_t)mg->mg_aliquot) / 100;
+ } else if (!metaslab_bias_enabled) {
+ mg->mg_bias = 0;
+ }
+
+ if ((flags & METASLAB_FASTWRITE) ||
+ 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) ? 1 : 0));
+ DVA_SET_ASIZE(&dva[d], asize);
+
+ if (flags & METASLAB_FASTWRITE) {
+ atomic_add_64(&vd->vdev_pending_fastwrite,
+ psize);
+ }
+
+ 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;
- vd = mg->mg_vd;
+ /* We can not remap split blocks. */
+ if (size != DVA_GET_ASIZE(&bp->blk_dva[0]))
+ return;
+ ASSERT0(inner_offset);
+ if (rbca->rbca_cb != NULL) {
/*
- * Don't allocate from faulted devices.
+ * 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.
*/
- if (zio_lock) {
- 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);
- }
- if (!allocatable)
- goto next;
+ ASSERT3P(rbca->rbca_remap_vd->vdev_ops, ==, &vdev_indirect_ops);
- /*
- * Avoid writing single-copy data to a failing vdev
- */
- if ((vd->vdev_stat.vs_write_errors > 0 ||
- vd->vdev_state < VDEV_STATE_HEALTHY) &&
- d == 0 && dshift == 3) {
- all_zero = B_FALSE;
- goto next;
- }
+ rbca->rbca_cb(rbca->rbca_remap_vd->vdev_id,
+ rbca->rbca_remap_offset, size, rbca->rbca_cb_arg);
- ASSERT(mg->mg_class == mc);
+ /* set up remap_blkptr_cb_arg for the next call */
+ rbca->rbca_remap_vd = vd;
+ rbca->rbca_remap_offset = offset;
+ }
- distance = vd->vdev_asize >> dshift;
- if (distance <= (1ULL << vd->vdev_ms_shift))
- distance = 0;
- else
- all_zero = B_FALSE;
+ /*
+ * 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);
+}
- asize = vdev_psize_to_asize(vd, psize);
- ASSERT(P2PHASE(asize, 1ULL << vd->vdev_ashift) == 0);
+/*
+ * 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;
- offset = metaslab_group_alloc(mg, psize, asize, txg, distance,
- dva, d, flags);
- 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) {
- vdev_stat_t *vs = &vd->vdev_stat;
- int64_t vu, cu;
+ if (!zfs_remap_blkptr_enable)
+ return (B_FALSE);
- vu = (vs->vs_alloc * 100) / (vs->vs_space + 1);
- cu = (mc->mc_alloc * 100) / (mc->mc_space + 1);
+ if (!spa_feature_is_enabled(spa, SPA_FEATURE_OBSOLETE_COUNTS))
+ return (B_FALSE);
- /*
- * 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;
- }
+ /*
+ * 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);
- if ((flags & METASLAB_FASTWRITE) ||
- atomic_add_64_nv(&mc->mc_aliquot, asize) >=
- mg->mg_aliquot + mg->mg_bias) {
- mc->mc_rotor = mg->mg_next;
- mc->mc_aliquot = 0;
- }
+ /*
+ * 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);
- 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);
+ /*
+ * Embedded BP's have no DVA to remap.
+ */
+ if (BP_GET_NDVAS(bp) < 1)
+ return (B_FALSE);
- if (flags & METASLAB_FASTWRITE) {
- atomic_add_64(&vd->vdev_pending_fastwrite,
- psize);
- mutex_exit(&mc->mc_fastwrite_lock);
- }
+ /*
+ * 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];
- return (0);
- }
-next:
- mc->mc_rotor = mg->mg_next;
- mc->mc_aliquot = 0;
- } while ((mg = mg->mg_next) != rotor);
+ 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 (!all_zero) {
- dshift++;
- ASSERT(dshift < 64);
- goto top;
- }
+ if (vd->vdev_ops->vdev_op_remap == NULL)
+ return (B_FALSE);
- if (!allocatable && !zio_lock) {
- dshift = 3;
- zio_lock = B_TRUE;
- goto top;
- }
+ rbca.rbca_bp = bp;
+ rbca.rbca_cb = callback;
+ rbca.rbca_remap_vd = vd;
+ rbca.rbca_remap_offset = offset;
+ rbca.rbca_cb_arg = arg;
- bzero(&dva[d], sizeof (dva_t));
+ /*
+ * 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);
- if (flags & METASLAB_FASTWRITE)
- mutex_exit(&mc->mc_fastwrite_lock);
- return (ENOSPC);
+ return (B_TRUE);
}
/*
- * Free the block represented by DVA in the context of the specified
- * transaction group.
+ * Undo the allocation of a DVA which happened in the given transaction group.
*/
-static void
-metaslab_free_dva(spa_t *spa, const dva_t *dva, uint64_t txg, boolean_t now)
+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);
- vdev_t *vd;
- metaslab_t *msp;
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 ||
+ if ((vd = vdev_lookup_top(spa, vdev)) == NULL || !DVA_IS_VALID(dva) ||
(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);
+ zfs_panic_recover("metaslab_free_dva(): bad DVA %llu:%llu:%llu",
+ (u_longlong_t)vdev, (u_longlong_t)offset,
+ (u_longlong_t)size);
return;
}
- msp = vd->vdev_ms[offset >> vd->vdev_ms_shift];
+ 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);
- mutex_enter(&msp->ms_lock);
-
- if (now) {
- space_map_remove(msp->ms_allocmap[txg & TXG_MASK],
- offset, size);
- space_map_free(msp->ms_map, offset, size);
- } else {
- if (msp->ms_freemap[txg & TXG_MASK]->sm_space == 0)
- vdev_dirty(vd, VDD_METASLAB, msp, txg);
- space_map_add(msp->ms_freemap[txg & TXG_MASK], offset, size);
- }
+ 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);
}
/*
- * 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.
+ * Free the block represented by the given DVA.
*/
-static int
-metaslab_claim_dva(spa_t *spa, const dva_t *dva, uint64_t txg)
+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;
- metaslab_t *msp;
- int error = 0;
+ vdev_t *vd = vdev_lookup_top(spa, vdev);
ASSERT(DVA_IS_VALID(dva));
+ ASSERT3U(spa_config_held(spa, SCL_ALL, RW_READER), !=, 0);
- if ((vd = vdev_lookup_top(spa, vdev)) == NULL ||
- (offset >> vd->vdev_ms_shift) >= vd->vdev_ms_count)
- return (ENXIO);
+ if (DVA_GET_GANG(dva)) {
+ size = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE);
+ }
- msp = vd->vdev_ms[offset >> vd->vdev_ms_shift];
+ metaslab_free_impl(vd, offset, size, checkpoint);
+}
- if (DVA_GET_GANG(dva))
- size = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE);
+/*
+ * 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 =
+ zfs_refcount_count(&mc->mc_alloc_slots[allocator]);
+ if (reserved_slots < max)
+ available_slots = max - reserved_slots;
+
+ if (slots <= available_slots || GANG_ALLOCATION(flags) ||
+ flags & METASLAB_MUST_RESERVE) {
+ /*
+ * 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 =
+ zfs_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) zfs_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 (SET_ERROR(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_map->sm_loaded)
- error = metaslab_activate(msp, METASLAB_WEIGHT_SECONDARY);
+ if ((txg != 0 && spa_writeable(spa)) || !msp->ms_loaded) {
+ error = metaslab_activate(msp, 0, METASLAB_WEIGHT_CLAIM);
+ if (error == EBUSY) {
+ ASSERT(msp->ms_loaded);
+ ASSERT(msp->ms_weight & METASLAB_ACTIVE_MASK);
+ error = 0;
+ }
+ }
- if (error == 0 && !space_map_contains(msp->ms_map, offset, size))
- error = ENOENT;
+ 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);
}
- space_map_claim(msp->ms_map, offset, size);
+ 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 (msp->ms_allocmap[txg & TXG_MASK]->sm_space == 0)
+ if (range_tree_is_empty(msp->ms_allocating[txg & TXG_MASK]))
vdev_dirty(vd, VDD_METASLAB, msp, txg);
- space_map_add(msp->ms_allocmap[txg & TXG_MASK], offset, size);
+ 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)
+ 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 d, error = 0;
+ dva_t *hintdva = (hintbp != NULL) ? hintbp->blk_dva : NULL;
+ int error = 0;
ASSERT(bp->blk_birth == 0);
ASSERT(BP_PHYSICAL_BIRTH(bp) == 0);
if (mc->mc_rotor == NULL) { /* no vdevs in this class */
spa_config_exit(spa, SCL_ALLOC, FTAG);
- return (ENOSPC);
+ 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 (d = 0; d < ndvas; d++) {
+ for (int d = 0; d < ndvas; d++) {
error = metaslab_alloc_dva(spa, mc, psize, dva, d, hintdva,
- txg, flags);
- if (error) {
+ txg, flags, zal, allocator);
+ if (error != 0) {
for (d--; d >= 0; d--) {
- metaslab_free_dva(spa, &dva[d], txg, B_TRUE);
+ 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);
+ BP_SET_BIRTH(bp, txg, 0);
return (0);
}
metaslab_free(spa_t *spa, const blkptr_t *bp, uint64_t txg, boolean_t now)
{
const dva_t *dva = bp->blk_dva;
- int d, ndvas = BP_GET_NDVAS(bp);
+ 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 (d = 0; d < ndvas; d++)
- metaslab_free_dva(spa, &dva[d], txg, now);
+ 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);
}
{
const dva_t *dva = bp->blk_dva;
int ndvas = BP_GET_NDVAS(bp);
- int d, error = 0;
+ int error = 0;
ASSERT(!BP_IS_HOLE(bp));
spa_config_enter(spa, SCL_ALLOC, FTAG, RW_READER);
- for (d = 0; d < ndvas; d++)
- if ((error = metaslab_claim_dva(spa, &dva[d], txg)) != 0)
+ for (int d = 0; d < ndvas; d++) {
+ error = metaslab_claim_dva(spa, &dva[d], txg);
+ if (error != 0)
break;
+ }
spa_config_exit(spa, SCL_ALLOC, FTAG);
return (error);
}
-void metaslab_fastwrite_mark(spa_t *spa, const blkptr_t *bp)
+void
+metaslab_fastwrite_mark(spa_t *spa, const blkptr_t *bp)
{
const dva_t *dva = bp->blk_dva;
int ndvas = BP_GET_NDVAS(bp);
vdev_t *vd;
ASSERT(!BP_IS_HOLE(bp));
+ ASSERT(!BP_IS_EMBEDDED(bp));
ASSERT(psize > 0);
spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
spa_config_exit(spa, SCL_VDEV, FTAG);
}
-void metaslab_fastwrite_unmark(spa_t *spa, const blkptr_t *bp)
+void
+metaslab_fastwrite_unmark(spa_t *spa, const blkptr_t *bp)
{
const dva_t *dva = bp->blk_dva;
int ndvas = BP_GET_NDVAS(bp);
vdev_t *vd;
ASSERT(!BP_IS_HOLE(bp));
+ ASSERT(!BP_IS_EMBEDDED(bp));
ASSERT(psize > 0);
spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
spa_config_exit(spa, SCL_VDEV, FTAG);
}
+/* ARGSUSED */
static void
-checkmap(space_map_t *sm, uint64_t off, uint64_t size)
+metaslab_check_free_impl_cb(uint64_t inner, vdev_t *vd, uint64_t offset,
+ uint64_t size, void *arg)
{
- space_seg_t *ss;
- avl_index_t where;
+ 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;
+ ASSERTV(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_not_present(msp->ms_allocatable,
+ offset, size);
+ }
- mutex_enter(sm->sm_lock);
- ss = space_map_find(sm, off, size, &where);
- if (ss != NULL)
- panic("freeing free block; ss=%p", (void *)ss);
- mutex_exit(sm->sm_lock);
+ range_tree_verify_not_present(msp->ms_freeing, offset, size);
+ range_tree_verify_not_present(msp->ms_checkpointing, offset, size);
+ range_tree_verify_not_present(msp->ms_freed, offset, size);
+ for (int j = 0; j < TXG_DEFER_SIZE; j++)
+ range_tree_verify_not_present(msp->ms_defer[j], offset, size);
+ mutex_exit(&msp->ms_lock);
}
void
metaslab_check_free(spa_t *spa, const blkptr_t *bp)
{
- int i, j;
-
if ((zfs_flags & ZFS_DEBUG_ZIO_FREE) == 0)
return;
spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER);
- for (i = 0; i < BP_GET_NDVAS(bp); i++) {
- uint64_t vdid = DVA_GET_VDEV(&bp->blk_dva[i]);
- vdev_t *vd = vdev_lookup_top(spa, vdid);
- uint64_t off = DVA_GET_OFFSET(&bp->blk_dva[i]);
+ 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]);
- metaslab_t *ms = vd->vdev_ms[off >> vd->vdev_ms_shift];
- if (ms->ms_map->sm_loaded)
- checkmap(ms->ms_map, off, size);
+ if (DVA_GET_GANG(&bp->blk_dva[i]))
+ size = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE);
- for (j = 0; j < TXG_SIZE; j++)
- checkmap(ms->ms_freemap[j], off, size);
- for (j = 0; j < TXG_DEFER_SIZE; j++)
- checkmap(ms->ms_defermap[j], off, size);
+ ASSERT3P(vd, !=, NULL);
+
+ metaslab_check_free_impl(vd, offset, size);
}
spa_config_exit(spa, SCL_VDEV, FTAG);
}
-#if defined(_KERNEL) && defined(HAVE_SPL)
-module_param(metaslab_debug, int, 0644);
-MODULE_PARM_DESC(metaslab_debug, "keep space maps in core to verify frees");
-#endif /* _KERNEL && HAVE_SPL */
+#if defined(_KERNEL)
+/* BEGIN CSTYLED */
+module_param(metaslab_aliquot, ulong, 0644);
+MODULE_PARM_DESC(metaslab_aliquot,
+ "allocation granularity (a.k.a. stripe size)");
+
+module_param(metaslab_debug_load, int, 0644);
+MODULE_PARM_DESC(metaslab_debug_load,
+ "load all metaslabs when pool is first opened");
+
+module_param(metaslab_debug_unload, int, 0644);
+MODULE_PARM_DESC(metaslab_debug_unload,
+ "prevent metaslabs from being unloaded");
+
+module_param(metaslab_preload_enabled, int, 0644);
+MODULE_PARM_DESC(metaslab_preload_enabled,
+ "preload potential metaslabs during reassessment");
+
+module_param(zfs_mg_noalloc_threshold, int, 0644);
+MODULE_PARM_DESC(zfs_mg_noalloc_threshold,
+ "percentage of free space for metaslab group to allow allocation");
+
+module_param(zfs_mg_fragmentation_threshold, int, 0644);
+MODULE_PARM_DESC(zfs_mg_fragmentation_threshold,
+ "fragmentation for metaslab group to allow allocation");
+
+module_param(zfs_metaslab_fragmentation_threshold, int, 0644);
+MODULE_PARM_DESC(zfs_metaslab_fragmentation_threshold,
+ "fragmentation for metaslab to allow allocation");
+
+module_param(metaslab_fragmentation_factor_enabled, int, 0644);
+MODULE_PARM_DESC(metaslab_fragmentation_factor_enabled,
+ "use the fragmentation metric to prefer less fragmented metaslabs");
+
+module_param(metaslab_lba_weighting_enabled, int, 0644);
+MODULE_PARM_DESC(metaslab_lba_weighting_enabled,
+ "prefer metaslabs with lower LBAs");
+
+module_param(metaslab_bias_enabled, int, 0644);
+MODULE_PARM_DESC(metaslab_bias_enabled,
+ "enable metaslab group biasing");
+
+module_param(zfs_metaslab_segment_weight_enabled, int, 0644);
+MODULE_PARM_DESC(zfs_metaslab_segment_weight_enabled,
+ "enable segment-based metaslab selection");
+
+module_param(zfs_metaslab_switch_threshold, int, 0644);
+MODULE_PARM_DESC(zfs_metaslab_switch_threshold,
+ "segment-based metaslab selection maximum buckets before switching");
+
+module_param(metaslab_force_ganging, ulong, 0644);
+MODULE_PARM_DESC(metaslab_force_ganging,
+ "blocks larger than this size are forced to be gang blocks");
+/* END CSTYLED */
+
+#endif
projects / mirror_zfs.git / blobdiff