X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libbcachefs%2Fmovinggc.c;h=256431a6dc0caf502b11808877b625848048ad75;hb=15b24c732749339e3f65f030e7e68624b1b4bfbd;hp=3b4a5292ef6a4007a0f0e71d248ad4a0157d7996;hpb=ff5e165532a2eed87700649d03f91a612a58e92a;p=bcachefs-tools-debian diff --git a/libbcachefs/movinggc.c b/libbcachefs/movinggc.c index 3b4a529..256431a 100644 --- a/libbcachefs/movinggc.c +++ b/libbcachefs/movinggc.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Moving/copying garbage collector * @@ -5,19 +6,27 @@ */ #include "bcachefs.h" +#include "alloc_background.h" +#include "alloc_foreground.h" #include "btree_iter.h" #include "btree_update.h" +#include "btree_write_buffer.h" #include "buckets.h" #include "clock.h" +#include "disk_groups.h" +#include "errcode.h" +#include "error.h" #include "extents.h" #include "eytzinger.h" #include "io.h" #include "keylist.h" +#include "lru.h" #include "move.h" #include "movinggc.h" #include "super-io.h" +#include "trace.h" -#include +#include #include #include #include @@ -25,258 +34,366 @@ #include #include -/* - * We can't use the entire copygc reserve in one iteration of copygc: we may - * need the buckets we're freeing up to go back into the copygc reserve to make - * forward progress, but if the copygc reserve is full they'll be available for - * any allocation - and it's possible that in a given iteration, we free up most - * of the buckets we're going to free before we allocate most of the buckets - * we're going to allocate. - * - * If we only use half of the reserve per iteration, then in steady state we'll - * always have room in the reserve for the buckets we're going to need in the - * next iteration: - */ -#define COPYGC_BUCKETS_PER_ITER(ca) \ - ((ca)->free[RESERVE_MOVINGGC].size / 2) +struct buckets_in_flight { + struct rhashtable table; + struct move_bucket_in_flight *first; + struct move_bucket_in_flight *last; + size_t nr; + size_t sectors; +}; + +static const struct rhashtable_params bch_move_bucket_params = { + .head_offset = offsetof(struct move_bucket_in_flight, hash), + .key_offset = offsetof(struct move_bucket_in_flight, bucket.k), + .key_len = sizeof(struct move_bucket_key), +}; + +static struct move_bucket_in_flight * +move_bucket_in_flight_add(struct buckets_in_flight *list, struct move_bucket b) +{ + struct move_bucket_in_flight *new = kzalloc(sizeof(*new), GFP_KERNEL); + int ret; -/* - * Max sectors to move per iteration: Have to take into account internal - * fragmentation from the multiple write points for each generation: - */ -#define COPYGC_SECTORS_PER_ITER(ca) \ - ((ca)->mi.bucket_size * COPYGC_BUCKETS_PER_ITER(ca)) + if (!new) + return ERR_PTR(-ENOMEM); -static inline int sectors_used_cmp(copygc_heap *heap, - struct copygc_heap_entry l, - struct copygc_heap_entry r) -{ - return bucket_sectors_used(l.mark) - bucket_sectors_used(r.mark); + new->bucket = b; + + ret = rhashtable_lookup_insert_fast(&list->table, &new->hash, + bch_move_bucket_params); + if (ret) { + kfree(new); + return ERR_PTR(ret); + } + + if (!list->first) + list->first = new; + else + list->last->next = new; + + list->last = new; + list->nr++; + list->sectors += b.sectors; + return new; } -static int bucket_offset_cmp(const void *_l, const void *_r, size_t size) +static int bch2_bucket_is_movable(struct btree_trans *trans, + struct move_bucket *b, u64 time) { - const struct copygc_heap_entry *l = _l; - const struct copygc_heap_entry *r = _r; + struct btree_iter iter; + struct bkey_s_c k; + struct bch_alloc_v4 _a; + const struct bch_alloc_v4 *a; + int ret; + + if (bch2_bucket_is_open(trans->c, + b->k.bucket.inode, + b->k.bucket.offset)) + return 0; + + k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_alloc, + b->k.bucket, BTREE_ITER_CACHED); + ret = bkey_err(k); + if (ret) + return ret; - return (l->offset > r->offset) - (l->offset < r->offset); + a = bch2_alloc_to_v4(k, &_a); + b->k.gen = a->gen; + b->sectors = a->dirty_sectors; + + ret = data_type_movable(a->data_type) && + a->fragmentation_lru && + a->fragmentation_lru <= time; + + bch2_trans_iter_exit(trans, &iter); + return ret; } -static bool __copygc_pred(struct bch_dev *ca, - struct bkey_s_c_extent e) +static void move_buckets_wait(struct btree_trans *trans, + struct moving_context *ctxt, + struct buckets_in_flight *list, + bool flush) { - copygc_heap *h = &ca->copygc_heap; - const struct bch_extent_ptr *ptr = - bch2_extent_has_device(e, ca->dev_idx); + struct move_bucket_in_flight *i; + int ret; - if (ptr) { - struct copygc_heap_entry search = { .offset = ptr->offset }; + while ((i = list->first)) { + if (flush) + move_ctxt_wait_event(ctxt, trans, !atomic_read(&i->count)); - ssize_t i = eytzinger0_find_le(h->data, h->used, - sizeof(h->data[0]), - bucket_offset_cmp, &search); + if (atomic_read(&i->count)) + break; + + list->first = i->next; + if (!list->first) + list->last = NULL; - return (i >= 0 && - ptr->offset < h->data[i].offset + ca->mi.bucket_size && - ptr->gen == h->data[i].mark.gen); + list->nr--; + list->sectors -= i->bucket.sectors; + + ret = rhashtable_remove_fast(&list->table, &i->hash, + bch_move_bucket_params); + BUG_ON(ret); + kfree(i); } - return false; + bch2_trans_unlock(trans); } -static enum data_cmd copygc_pred(struct bch_fs *c, void *arg, - enum bkey_type type, - struct bkey_s_c_extent e, - struct bch_io_opts *io_opts, - struct data_opts *data_opts) +static bool bucket_in_flight(struct buckets_in_flight *list, + struct move_bucket_key k) { - struct bch_dev *ca = arg; - - if (!__copygc_pred(ca, e)) - return DATA_SKIP; - - data_opts->target = dev_to_target(ca->dev_idx); - data_opts->btree_insert_flags = BTREE_INSERT_USE_RESERVE; - data_opts->rewrite_dev = ca->dev_idx; - return DATA_REWRITE; + return rhashtable_lookup_fast(&list->table, &k, bch_move_bucket_params); } -static bool have_copygc_reserve(struct bch_dev *ca) +typedef DARRAY(struct move_bucket) move_buckets; + +static int bch2_copygc_get_buckets(struct btree_trans *trans, + struct moving_context *ctxt, + struct buckets_in_flight *buckets_in_flight, + move_buckets *buckets) { - bool ret; + struct bch_fs *c = trans->c; + struct btree_iter iter; + struct bkey_s_c k; + size_t nr_to_get = max(16UL, buckets_in_flight->nr / 4); + size_t saw = 0, in_flight = 0, not_movable = 0, sectors = 0; + int ret; - spin_lock(&ca->freelist_lock); - ret = fifo_full(&ca->free[RESERVE_MOVINGGC]) || - ca->allocator_blocked; - spin_unlock(&ca->freelist_lock); + move_buckets_wait(trans, ctxt, buckets_in_flight, false); + + ret = bch2_btree_write_buffer_flush(trans); + if (bch2_fs_fatal_err_on(ret, c, "%s: error %s from bch2_btree_write_buffer_flush()", + __func__, bch2_err_str(ret))) + return ret; + + ret = for_each_btree_key2_upto(trans, iter, BTREE_ID_lru, + lru_pos(BCH_LRU_FRAGMENTATION_START, 0, 0), + lru_pos(BCH_LRU_FRAGMENTATION_START, U64_MAX, LRU_TIME_MAX), + 0, k, ({ + struct move_bucket b = { .k.bucket = u64_to_bucket(k.k->p.offset) }; + int ret = 0; + + saw++; + + if (!bch2_bucket_is_movable(trans, &b, lru_pos_time(k.k->p))) + not_movable++; + else if (bucket_in_flight(buckets_in_flight, b.k)) + in_flight++; + else { + ret = darray_push(buckets, b) ?: buckets->nr >= nr_to_get; + if (ret >= 0) + sectors += b.sectors; + } + ret; + })); - return ret; + pr_debug("have: %zu (%zu) saw %zu in flight %zu not movable %zu got %zu (%zu)/%zu buckets ret %i", + buckets_in_flight->nr, buckets_in_flight->sectors, + saw, in_flight, not_movable, buckets->nr, sectors, nr_to_get, ret); + + return ret < 0 ? ret : 0; } -static void bch2_copygc(struct bch_fs *c, struct bch_dev *ca) +noinline +static int bch2_copygc(struct btree_trans *trans, + struct moving_context *ctxt, + struct buckets_in_flight *buckets_in_flight) { - copygc_heap *h = &ca->copygc_heap; - struct copygc_heap_entry e, *i; - struct bucket_array *buckets; - struct bch_move_stats move_stats; - u64 sectors_to_move = 0, sectors_not_moved = 0; - u64 buckets_to_move, buckets_not_moved = 0; - size_t b; - int ret; + struct bch_fs *c = trans->c; + struct data_update_opts data_opts = { + .btree_insert_flags = BCH_WATERMARK_copygc, + }; + move_buckets buckets = { 0 }; + struct move_bucket_in_flight *f; + struct move_bucket *i; + u64 moved = atomic64_read(&ctxt->stats->sectors_moved); + int ret = 0; + + ret = bch2_copygc_get_buckets(trans, ctxt, buckets_in_flight, &buckets); + if (ret) + goto err; + + darray_for_each(buckets, i) { + if (unlikely(freezing(current))) + break; - memset(&move_stats, 0, sizeof(move_stats)); - closure_wait_event(&c->freelist_wait, have_copygc_reserve(ca)); - - /* - * Find buckets with lowest sector counts, skipping completely - * empty buckets, by building a maxheap sorted by sector count, - * and repeatedly replacing the maximum element until all - * buckets have been visited. - */ - h->used = 0; - - /* - * We need bucket marks to be up to date - gc can't be recalculating - * them: - */ - down_read(&c->gc_lock); - down_read(&ca->bucket_lock); - buckets = bucket_array(ca); - - for (b = buckets->first_bucket; b < buckets->nbuckets; b++) { - struct bucket_mark m = READ_ONCE(buckets->b[b].mark); - struct copygc_heap_entry e; - - if (m.owned_by_allocator || - m.data_type != BCH_DATA_USER || - !bucket_sectors_used(m) || - bucket_sectors_used(m) >= ca->mi.bucket_size) + f = move_bucket_in_flight_add(buckets_in_flight, *i); + ret = PTR_ERR_OR_ZERO(f); + if (ret == -EEXIST) { /* rare race: copygc_get_buckets returned same bucket more than once */ + ret = 0; continue; + } + if (ret == -ENOMEM) { /* flush IO, continue later */ + ret = 0; + break; + } - e = (struct copygc_heap_entry) { - .offset = bucket_to_sector(ca, b), - .mark = m - }; - heap_add_or_replace(h, e, -sectors_used_cmp); + ret = __bch2_evacuate_bucket(trans, ctxt, f, f->bucket.k.bucket, + f->bucket.k.gen, data_opts); + if (ret) + goto err; } - up_read(&ca->bucket_lock); - up_read(&c->gc_lock); +err: + darray_exit(&buckets); - for (i = h->data; i < h->data + h->used; i++) - sectors_to_move += bucket_sectors_used(i->mark); + /* no entries in LRU btree found, or got to end: */ + if (bch2_err_matches(ret, ENOENT)) + ret = 0; - while (sectors_to_move > COPYGC_SECTORS_PER_ITER(ca)) { - BUG_ON(!heap_pop(h, e, -sectors_used_cmp)); - sectors_to_move -= bucket_sectors_used(e.mark); - } + if (ret < 0 && !bch2_err_matches(ret, EROFS)) + bch_err(c, "error from bch2_move_data() in copygc: %s", bch2_err_str(ret)); - buckets_to_move = h->used; + moved = atomic64_read(&ctxt->stats->sectors_moved) - moved; + trace_and_count(c, copygc, c, moved, 0, 0, 0); + return ret; +} - if (!buckets_to_move) - return; +/* + * Copygc runs when the amount of fragmented data is above some arbitrary + * threshold: + * + * The threshold at the limit - when the device is full - is the amount of space + * we reserved in bch2_recalc_capacity; we can't have more than that amount of + * disk space stranded due to fragmentation and store everything we have + * promised to store. + * + * But we don't want to be running copygc unnecessarily when the device still + * has plenty of free space - rather, we want copygc to smoothly run every so + * often and continually reduce the amount of fragmented space as the device + * fills up. So, we increase the threshold by half the current free space. + */ +unsigned long bch2_copygc_wait_amount(struct bch_fs *c) +{ + struct bch_dev *ca; + unsigned dev_idx; + s64 wait = S64_MAX, fragmented_allowed, fragmented; + unsigned i; - eytzinger0_sort(h->data, h->used, - sizeof(h->data[0]), - bucket_offset_cmp, NULL); + for_each_rw_member(ca, c, dev_idx) { + struct bch_dev_usage usage = bch2_dev_usage_read(ca); - ret = bch2_move_data(c, &ca->copygc_pd.rate, - writepoint_ptr(&ca->copygc_write_point), - POS_MIN, POS_MAX, - copygc_pred, ca, - &move_stats); + fragmented_allowed = ((__dev_buckets_available(ca, usage, BCH_WATERMARK_stripe) * + ca->mi.bucket_size) >> 1); + fragmented = 0; - down_read(&ca->bucket_lock); - buckets = bucket_array(ca); - for (i = h->data; i < h->data + h->used; i++) { - size_t b = sector_to_bucket(ca, i->offset); - struct bucket_mark m = READ_ONCE(buckets->b[b].mark); + for (i = 0; i < BCH_DATA_NR; i++) + if (data_type_movable(i)) + fragmented += usage.d[i].fragmented; - if (i->mark.gen == m.gen && bucket_sectors_used(m)) { - sectors_not_moved += bucket_sectors_used(m); - buckets_not_moved++; - } + wait = min(wait, max(0LL, fragmented_allowed - fragmented)); } - up_read(&ca->bucket_lock); - if (sectors_not_moved && !ret) - bch_warn(c, "copygc finished but %llu/%llu sectors, %llu/%llu buckets not moved", - sectors_not_moved, sectors_to_move, - buckets_not_moved, buckets_to_move); + return wait; +} - trace_copygc(ca, - atomic64_read(&move_stats.sectors_moved), sectors_not_moved, - buckets_to_move, buckets_not_moved); +void bch2_copygc_wait_to_text(struct printbuf *out, struct bch_fs *c) +{ + prt_printf(out, "Currently waiting for: "); + prt_human_readable_u64(out, max(0LL, c->copygc_wait - + atomic64_read(&c->io_clock[WRITE].now)) << 9); + prt_newline(out); + + prt_printf(out, "Currently waiting since: "); + prt_human_readable_u64(out, max(0LL, + atomic64_read(&c->io_clock[WRITE].now) - + c->copygc_wait_at) << 9); + prt_newline(out); + + prt_printf(out, "Currently calculated wait: "); + prt_human_readable_u64(out, bch2_copygc_wait_amount(c)); + prt_newline(out); } static int bch2_copygc_thread(void *arg) { - struct bch_dev *ca = arg; - struct bch_fs *c = ca->fs; + struct bch_fs *c = arg; + struct btree_trans trans; + struct moving_context ctxt; + struct bch_move_stats move_stats; struct io_clock *clock = &c->io_clock[WRITE]; - struct bch_dev_usage usage; - unsigned long last; - u64 available, fragmented, reserve, next; + struct buckets_in_flight move_buckets; + u64 last, wait; + int ret = 0; - set_freezable(); + memset(&move_buckets, 0, sizeof(move_buckets)); - while (!kthread_should_stop()) { - if (kthread_wait_freezable(c->copy_gc_enabled)) - break; + ret = rhashtable_init(&move_buckets.table, &bch_move_bucket_params); + if (ret) { + bch_err(c, "error allocating copygc buckets in flight: %s", + bch2_err_str(ret)); + return ret; + } - last = atomic_long_read(&clock->now); + set_freezable(); + bch2_trans_init(&trans, c, 0, 0); + + bch2_move_stats_init(&move_stats, "copygc"); + bch2_moving_ctxt_init(&ctxt, c, NULL, &move_stats, + writepoint_ptr(&c->copygc_write_point), + false); - reserve = div64_u64((ca->mi.nbuckets - ca->mi.first_bucket) * - ca->mi.bucket_size * - c->opts.gc_reserve_percent, 200); + while (!ret && !kthread_should_stop()) { + bch2_trans_unlock(&trans); + cond_resched(); - usage = bch2_dev_usage_read(c, ca); + if (!c->copy_gc_enabled) { + move_buckets_wait(&trans, &ctxt, &move_buckets, true); + kthread_wait_freezable(c->copy_gc_enabled); + } - /* - * don't start copygc until less than half the gc reserve is - * available: - */ - available = __dev_buckets_available(ca, usage) * - ca->mi.bucket_size; - if (available > reserve) { - next = last + available - reserve; - bch2_kthread_io_clock_wait(clock, next); + if (unlikely(freezing(current))) { + move_buckets_wait(&trans, &ctxt, &move_buckets, true); + __refrigerator(false); continue; } - /* - * don't start copygc until there's more than half the copygc - * reserve of fragmented space: - */ - fragmented = usage.sectors_fragmented; - if (fragmented < reserve) { - next = last + reserve - fragmented; - bch2_kthread_io_clock_wait(clock, next); + last = atomic64_read(&clock->now); + wait = bch2_copygc_wait_amount(c); + + if (wait > clock->max_slop) { + c->copygc_wait_at = last; + c->copygc_wait = last + wait; + move_buckets_wait(&trans, &ctxt, &move_buckets, true); + trace_and_count(c, copygc_wait, c, wait, last + wait); + bch2_kthread_io_clock_wait(clock, last + wait, + MAX_SCHEDULE_TIMEOUT); continue; } - bch2_copygc(c, ca); + c->copygc_wait = 0; + + c->copygc_running = true; + ret = bch2_copygc(&trans, &ctxt, &move_buckets); + c->copygc_running = false; + + wake_up(&c->copygc_running_wq); } + move_buckets_wait(&trans, &ctxt, &move_buckets, true); + rhashtable_destroy(&move_buckets.table); + bch2_trans_exit(&trans); + bch2_moving_ctxt_exit(&ctxt); + return 0; } -void bch2_copygc_stop(struct bch_dev *ca) +void bch2_copygc_stop(struct bch_fs *c) { - ca->copygc_pd.rate.rate = UINT_MAX; - bch2_ratelimit_reset(&ca->copygc_pd.rate); - - if (ca->copygc_thread) { - kthread_stop(ca->copygc_thread); - put_task_struct(ca->copygc_thread); + if (c->copygc_thread) { + kthread_stop(c->copygc_thread); + put_task_struct(c->copygc_thread); } - ca->copygc_thread = NULL; + c->copygc_thread = NULL; } -int bch2_copygc_start(struct bch_fs *c, struct bch_dev *ca) +int bch2_copygc_start(struct bch_fs *c) { struct task_struct *t; + int ret; - BUG_ON(ca->copygc_thread); + if (c->copygc_thread) + return 0; if (c->opts.nochanges) return 0; @@ -284,20 +401,23 @@ int bch2_copygc_start(struct bch_fs *c, struct bch_dev *ca) if (bch2_fs_init_fault("copygc_start")) return -ENOMEM; - t = kthread_create(bch2_copygc_thread, ca, "bch_copygc"); - if (IS_ERR(t)) - return PTR_ERR(t); + t = kthread_create(bch2_copygc_thread, c, "bch-copygc/%s", c->name); + ret = PTR_ERR_OR_ZERO(t); + if (ret) { + bch_err(c, "error creating copygc thread: %s", bch2_err_str(ret)); + return ret; + } get_task_struct(t); - ca->copygc_thread = t; - wake_up_process(ca->copygc_thread); + c->copygc_thread = t; + wake_up_process(c->copygc_thread); return 0; } -void bch2_dev_copygc_init(struct bch_dev *ca) +void bch2_fs_copygc_init(struct bch_fs *c) { - bch2_pd_controller_init(&ca->copygc_pd); - ca->copygc_pd.d_term = 0; + init_waitqueue_head(&c->copygc_running_wq); + c->copygc_running = false; }