From 7b3f84ea7d3f9bcbb7f0f1264a4c228a27a32703 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Sat, 6 Oct 2018 00:46:55 -0400 Subject: bcachefs: Split out alloc_background.c Signed-off-by: Kent Overstreet --- fs/bcachefs/alloc_background.c | 1428 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1428 insertions(+) create mode 100644 fs/bcachefs/alloc_background.c (limited to 'fs/bcachefs/alloc_background.c') diff --git a/fs/bcachefs/alloc_background.c b/fs/bcachefs/alloc_background.c new file mode 100644 index 000000000000..d22b2b72b0d1 --- /dev/null +++ b/fs/bcachefs/alloc_background.c @@ -0,0 +1,1428 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "bcachefs.h" +#include "alloc_background.h" +#include "alloc_foreground.h" +#include "btree_cache.h" +#include "btree_io.h" +#include "btree_update.h" +#include "btree_update_interior.h" +#include "btree_gc.h" +#include "buckets.h" +#include "clock.h" +#include "debug.h" +#include "error.h" +#include "journal_io.h" +#include "trace.h" + +#include +#include +#include +#include +#include +#include +#include + +static void bch2_recalc_oldest_io(struct bch_fs *, struct bch_dev *, int); + +/* Ratelimiting/PD controllers */ + +static void pd_controllers_update(struct work_struct *work) +{ + struct bch_fs *c = container_of(to_delayed_work(work), + struct bch_fs, + pd_controllers_update); + struct bch_dev *ca; + unsigned i; + + for_each_member_device(ca, c, i) { + struct bch_dev_usage stats = bch2_dev_usage_read(c, ca); + + u64 free = bucket_to_sector(ca, + __dev_buckets_free(ca, stats)) << 9; + /* + * Bytes of internal fragmentation, which can be + * reclaimed by copy GC + */ + s64 fragmented = (bucket_to_sector(ca, + stats.buckets[BCH_DATA_USER] + + stats.buckets[BCH_DATA_CACHED]) - + (stats.sectors[BCH_DATA_USER] + + stats.sectors[BCH_DATA_CACHED])) << 9; + + fragmented = max(0LL, fragmented); + + bch2_pd_controller_update(&ca->copygc_pd, + free, fragmented, -1); + } + + schedule_delayed_work(&c->pd_controllers_update, + c->pd_controllers_update_seconds * HZ); +} + +/* Persistent alloc info: */ + +static unsigned bch_alloc_val_u64s(const struct bch_alloc *a) +{ + unsigned bytes = offsetof(struct bch_alloc, data); + + if (a->fields & (1 << BCH_ALLOC_FIELD_READ_TIME)) + bytes += 2; + if (a->fields & (1 << BCH_ALLOC_FIELD_WRITE_TIME)) + bytes += 2; + + return DIV_ROUND_UP(bytes, sizeof(u64)); +} + +const char *bch2_alloc_invalid(const struct bch_fs *c, struct bkey_s_c k) +{ + if (k.k->p.inode >= c->sb.nr_devices || + !c->devs[k.k->p.inode]) + return "invalid device"; + + switch (k.k->type) { + case BCH_ALLOC: { + struct bkey_s_c_alloc a = bkey_s_c_to_alloc(k); + + if (bch_alloc_val_u64s(a.v) != bkey_val_u64s(a.k)) + return "incorrect value size"; + break; + } + default: + return "invalid type"; + } + + return NULL; +} + +int bch2_alloc_to_text(struct bch_fs *c, char *buf, + size_t size, struct bkey_s_c k) +{ + buf[0] = '\0'; + + switch (k.k->type) { + case BCH_ALLOC: + break; + } + + return 0; +} + +static inline unsigned get_alloc_field(const u8 **p, unsigned bytes) +{ + unsigned v; + + switch (bytes) { + case 1: + v = **p; + break; + case 2: + v = le16_to_cpup((void *) *p); + break; + case 4: + v = le32_to_cpup((void *) *p); + break; + default: + BUG(); + } + + *p += bytes; + return v; +} + +static inline void put_alloc_field(u8 **p, unsigned bytes, unsigned v) +{ + switch (bytes) { + case 1: + **p = v; + break; + case 2: + *((__le16 *) *p) = cpu_to_le16(v); + break; + case 4: + *((__le32 *) *p) = cpu_to_le32(v); + break; + default: + BUG(); + } + + *p += bytes; +} + +static void bch2_alloc_read_key(struct bch_fs *c, struct bkey_s_c k) +{ + struct bch_dev *ca; + struct bkey_s_c_alloc a; + struct bucket_mark new; + struct bucket *g; + const u8 *d; + + if (k.k->type != BCH_ALLOC) + return; + + a = bkey_s_c_to_alloc(k); + ca = bch_dev_bkey_exists(c, a.k->p.inode); + + if (a.k->p.offset >= ca->mi.nbuckets) + return; + + percpu_down_read(&c->usage_lock); + + g = bucket(ca, a.k->p.offset); + bucket_cmpxchg(g, new, ({ + new.gen = a.v->gen; + new.gen_valid = 1; + })); + + d = a.v->data; + if (a.v->fields & (1 << BCH_ALLOC_FIELD_READ_TIME)) + g->io_time[READ] = get_alloc_field(&d, 2); + if (a.v->fields & (1 << BCH_ALLOC_FIELD_WRITE_TIME)) + g->io_time[WRITE] = get_alloc_field(&d, 2); + + percpu_up_read(&c->usage_lock); +} + +int bch2_alloc_read(struct bch_fs *c, struct list_head *journal_replay_list) +{ + struct journal_replay *r; + struct btree_iter iter; + struct bkey_s_c k; + struct bch_dev *ca; + unsigned i; + int ret; + + for_each_btree_key(&iter, c, BTREE_ID_ALLOC, POS_MIN, 0, k) { + bch2_alloc_read_key(c, k); + bch2_btree_iter_cond_resched(&iter); + } + + ret = bch2_btree_iter_unlock(&iter); + if (ret) + return ret; + + list_for_each_entry(r, journal_replay_list, list) { + struct bkey_i *k, *n; + struct jset_entry *entry; + + for_each_jset_key(k, n, entry, &r->j) + if (entry->btree_id == BTREE_ID_ALLOC) + bch2_alloc_read_key(c, bkey_i_to_s_c(k)); + } + + mutex_lock(&c->bucket_clock[READ].lock); + for_each_member_device(ca, c, i) { + down_read(&ca->bucket_lock); + bch2_recalc_oldest_io(c, ca, READ); + up_read(&ca->bucket_lock); + } + mutex_unlock(&c->bucket_clock[READ].lock); + + mutex_lock(&c->bucket_clock[WRITE].lock); + for_each_member_device(ca, c, i) { + down_read(&ca->bucket_lock); + bch2_recalc_oldest_io(c, ca, WRITE); + up_read(&ca->bucket_lock); + } + mutex_unlock(&c->bucket_clock[WRITE].lock); + + return 0; +} + +static int __bch2_alloc_write_key(struct bch_fs *c, struct bch_dev *ca, + size_t b, struct btree_iter *iter, + u64 *journal_seq, unsigned flags) +{ + struct bucket_mark m; + __BKEY_PADDED(k, DIV_ROUND_UP(sizeof(struct bch_alloc), 8)) alloc_key; + struct bucket *g; + struct bkey_i_alloc *a; + u8 *d; + + percpu_down_read(&c->usage_lock); + g = bucket(ca, b); + + m = READ_ONCE(g->mark); + a = bkey_alloc_init(&alloc_key.k); + a->k.p = POS(ca->dev_idx, b); + a->v.fields = 0; + a->v.gen = m.gen; + set_bkey_val_u64s(&a->k, bch_alloc_val_u64s(&a->v)); + + d = a->v.data; + if (a->v.fields & (1 << BCH_ALLOC_FIELD_READ_TIME)) + put_alloc_field(&d, 2, g->io_time[READ]); + if (a->v.fields & (1 << BCH_ALLOC_FIELD_WRITE_TIME)) + put_alloc_field(&d, 2, g->io_time[WRITE]); + percpu_up_read(&c->usage_lock); + + bch2_btree_iter_cond_resched(iter); + + bch2_btree_iter_set_pos(iter, a->k.p); + + return bch2_btree_insert_at(c, NULL, journal_seq, + BTREE_INSERT_NOFAIL| + BTREE_INSERT_USE_RESERVE| + BTREE_INSERT_USE_ALLOC_RESERVE| + flags, + BTREE_INSERT_ENTRY(iter, &a->k_i)); +} + +int bch2_alloc_replay_key(struct bch_fs *c, struct bpos pos) +{ + struct bch_dev *ca; + struct btree_iter iter; + int ret; + + if (pos.inode >= c->sb.nr_devices || !c->devs[pos.inode]) + return 0; + + ca = bch_dev_bkey_exists(c, pos.inode); + + if (pos.offset >= ca->mi.nbuckets) + return 0; + + bch2_btree_iter_init(&iter, c, BTREE_ID_ALLOC, POS_MIN, + BTREE_ITER_SLOTS|BTREE_ITER_INTENT); + + ret = __bch2_alloc_write_key(c, ca, pos.offset, &iter, NULL, 0); + bch2_btree_iter_unlock(&iter); + return ret; +} + +int bch2_alloc_write(struct bch_fs *c) +{ + struct bch_dev *ca; + unsigned i; + int ret = 0; + + for_each_rw_member(ca, c, i) { + struct btree_iter iter; + unsigned long bucket; + + bch2_btree_iter_init(&iter, c, BTREE_ID_ALLOC, POS_MIN, + BTREE_ITER_SLOTS|BTREE_ITER_INTENT); + + down_read(&ca->bucket_lock); + for_each_set_bit(bucket, ca->buckets_dirty, ca->mi.nbuckets) { + ret = __bch2_alloc_write_key(c, ca, bucket, + &iter, NULL, 0); + if (ret) + break; + + clear_bit(bucket, ca->buckets_dirty); + } + up_read(&ca->bucket_lock); + bch2_btree_iter_unlock(&iter); + + if (ret) { + percpu_ref_put(&ca->io_ref); + break; + } + } + + return ret; +} + +/* Bucket IO clocks: */ + +static void bch2_recalc_oldest_io(struct bch_fs *c, struct bch_dev *ca, int rw) +{ + struct bucket_clock *clock = &c->bucket_clock[rw]; + struct bucket_array *buckets = bucket_array(ca); + struct bucket *g; + u16 max_last_io = 0; + unsigned i; + + lockdep_assert_held(&c->bucket_clock[rw].lock); + + /* Recalculate max_last_io for this device: */ + for_each_bucket(g, buckets) + max_last_io = max(max_last_io, bucket_last_io(c, g, rw)); + + ca->max_last_bucket_io[rw] = max_last_io; + + /* Recalculate global max_last_io: */ + max_last_io = 0; + + for_each_member_device(ca, c, i) + max_last_io = max(max_last_io, ca->max_last_bucket_io[rw]); + + clock->max_last_io = max_last_io; +} + +static void bch2_rescale_bucket_io_times(struct bch_fs *c, int rw) +{ + struct bucket_clock *clock = &c->bucket_clock[rw]; + struct bucket_array *buckets; + struct bch_dev *ca; + struct bucket *g; + unsigned i; + + trace_rescale_prios(c); + + for_each_member_device(ca, c, i) { + down_read(&ca->bucket_lock); + buckets = bucket_array(ca); + + for_each_bucket(g, buckets) + g->io_time[rw] = clock->hand - + bucket_last_io(c, g, rw) / 2; + + bch2_recalc_oldest_io(c, ca, rw); + + up_read(&ca->bucket_lock); + } +} + +static void bch2_inc_clock_hand(struct io_timer *timer) +{ + struct bucket_clock *clock = container_of(timer, + struct bucket_clock, rescale); + struct bch_fs *c = container_of(clock, + struct bch_fs, bucket_clock[clock->rw]); + struct bch_dev *ca; + u64 capacity; + unsigned i; + + mutex_lock(&clock->lock); + + /* if clock cannot be advanced more, rescale prio */ + if (clock->max_last_io >= U16_MAX - 2) + bch2_rescale_bucket_io_times(c, clock->rw); + + BUG_ON(clock->max_last_io >= U16_MAX - 2); + + for_each_member_device(ca, c, i) + ca->max_last_bucket_io[clock->rw]++; + clock->max_last_io++; + clock->hand++; + + mutex_unlock(&clock->lock); + + capacity = READ_ONCE(c->capacity); + + if (!capacity) + return; + + /* + * we only increment when 0.1% of the filesystem capacity has been read + * or written too, this determines if it's time + * + * XXX: we shouldn't really be going off of the capacity of devices in + * RW mode (that will be 0 when we're RO, yet we can still service + * reads) + */ + timer->expire += capacity >> 10; + + bch2_io_timer_add(&c->io_clock[clock->rw], timer); +} + +static void bch2_bucket_clock_init(struct bch_fs *c, int rw) +{ + struct bucket_clock *clock = &c->bucket_clock[rw]; + + clock->hand = 1; + clock->rw = rw; + clock->rescale.fn = bch2_inc_clock_hand; + clock->rescale.expire = c->capacity >> 10; + mutex_init(&clock->lock); +} + +/* Background allocator thread: */ + +/* + * Scans for buckets to be invalidated, invalidates them, rewrites prios/gens + * (marking them as invalidated on disk), then optionally issues discard + * commands to the newly free buckets, then puts them on the various freelists. + */ + +#define BUCKET_GC_GEN_MAX 96U + +/** + * wait_buckets_available - wait on reclaimable buckets + * + * If there aren't enough available buckets to fill up free_inc, wait until + * there are. + */ +static int wait_buckets_available(struct bch_fs *c, struct bch_dev *ca) +{ + unsigned long gc_count = c->gc_count; + int ret = 0; + + while (1) { + set_current_state(TASK_INTERRUPTIBLE); + if (kthread_should_stop()) { + ret = 1; + break; + } + + if (gc_count != c->gc_count) + ca->inc_gen_really_needs_gc = 0; + + if ((ssize_t) (dev_buckets_available(c, ca) - + ca->inc_gen_really_needs_gc) >= + (ssize_t) fifo_free(&ca->free_inc)) + break; + + up_read(&c->gc_lock); + schedule(); + try_to_freeze(); + down_read(&c->gc_lock); + } + + __set_current_state(TASK_RUNNING); + return ret; +} + +static bool bch2_can_invalidate_bucket(struct bch_dev *ca, + size_t bucket, + struct bucket_mark mark) +{ + u8 gc_gen; + + if (!is_available_bucket(mark)) + return false; + + gc_gen = bucket_gc_gen(ca, bucket); + + if (gc_gen >= BUCKET_GC_GEN_MAX / 2) + ca->inc_gen_needs_gc++; + + if (gc_gen >= BUCKET_GC_GEN_MAX) + ca->inc_gen_really_needs_gc++; + + return gc_gen < BUCKET_GC_GEN_MAX; +} + +/* + * Determines what order we're going to reuse buckets, smallest bucket_key() + * first. + * + * + * - We take into account the read prio of the bucket, which gives us an + * indication of how hot the data is -- we scale the prio so that the prio + * farthest from the clock is worth 1/8th of the closest. + * + * - The number of sectors of cached data in the bucket, which gives us an + * indication of the cost in cache misses this eviction will cause. + * + * - If hotness * sectors used compares equal, we pick the bucket with the + * smallest bucket_gc_gen() - since incrementing the same bucket's generation + * number repeatedly forces us to run mark and sweep gc to avoid generation + * number wraparound. + */ + +static unsigned long bucket_sort_key(struct bch_fs *c, struct bch_dev *ca, + size_t b, struct bucket_mark m) +{ + unsigned last_io = bucket_last_io(c, bucket(ca, b), READ); + unsigned max_last_io = ca->max_last_bucket_io[READ]; + + /* + * Time since last read, scaled to [0, 8) where larger value indicates + * more recently read data: + */ + unsigned long hotness = (max_last_io - last_io) * 7 / max_last_io; + + /* How much we want to keep the data in this bucket: */ + unsigned long data_wantness = + (hotness + 1) * bucket_sectors_used(m); + + unsigned long needs_journal_commit = + bucket_needs_journal_commit(m, c->journal.last_seq_ondisk); + + return (data_wantness << 9) | + (needs_journal_commit << 8) | + (bucket_gc_gen(ca, b) / 16); +} + +static inline int bucket_alloc_cmp(alloc_heap *h, + struct alloc_heap_entry l, + struct alloc_heap_entry r) +{ + return (l.key > r.key) - (l.key < r.key) ?: + (l.nr < r.nr) - (l.nr > r.nr) ?: + (l.bucket > r.bucket) - (l.bucket < r.bucket); +} + +static inline int bucket_idx_cmp(const void *_l, const void *_r) +{ + const struct alloc_heap_entry *l = _l, *r = _r; + + return (l->bucket > r->bucket) - (l->bucket < r->bucket); +} + +static void find_reclaimable_buckets_lru(struct bch_fs *c, struct bch_dev *ca) +{ + struct bucket_array *buckets; + struct alloc_heap_entry e = { 0 }; + size_t b, i, nr = 0; + + ca->alloc_heap.used = 0; + + mutex_lock(&c->bucket_clock[READ].lock); + down_read(&ca->bucket_lock); + + buckets = bucket_array(ca); + + bch2_recalc_oldest_io(c, ca, READ); + + /* + * Find buckets with lowest read priority, by building a maxheap sorted + * by read priority and repeatedly replacing the maximum element until + * all buckets have been visited. + */ + for (b = ca->mi.first_bucket; b < ca->mi.nbuckets; b++) { + struct bucket_mark m = READ_ONCE(buckets->b[b].mark); + unsigned long key = bucket_sort_key(c, ca, b, m); + + if (!bch2_can_invalidate_bucket(ca, b, m)) + continue; + + if (e.nr && e.bucket + e.nr == b && e.key == key) { + e.nr++; + } else { + if (e.nr) + heap_add_or_replace(&ca->alloc_heap, e, -bucket_alloc_cmp); + + e = (struct alloc_heap_entry) { + .bucket = b, + .nr = 1, + .key = key, + }; + } + + cond_resched(); + } + + if (e.nr) + heap_add_or_replace(&ca->alloc_heap, e, -bucket_alloc_cmp); + + for (i = 0; i < ca->alloc_heap.used; i++) + nr += ca->alloc_heap.data[i].nr; + + while (nr - ca->alloc_heap.data[0].nr >= ALLOC_SCAN_BATCH(ca)) { + nr -= ca->alloc_heap.data[0].nr; + heap_pop(&ca->alloc_heap, e, -bucket_alloc_cmp); + } + + up_read(&ca->bucket_lock); + mutex_unlock(&c->bucket_clock[READ].lock); +} + +static void find_reclaimable_buckets_fifo(struct bch_fs *c, struct bch_dev *ca) +{ + struct bucket_array *buckets = bucket_array(ca); + struct bucket_mark m; + size_t b, start; + + if (ca->fifo_last_bucket < ca->mi.first_bucket || + ca->fifo_last_bucket >= ca->mi.nbuckets) + ca->fifo_last_bucket = ca->mi.first_bucket; + + start = ca->fifo_last_bucket; + + do { + ca->fifo_last_bucket++; + if (ca->fifo_last_bucket == ca->mi.nbuckets) + ca->fifo_last_bucket = ca->mi.first_bucket; + + b = ca->fifo_last_bucket; + m = READ_ONCE(buckets->b[b].mark); + + if (bch2_can_invalidate_bucket(ca, b, m)) { + struct alloc_heap_entry e = { .bucket = b, .nr = 1, }; + + heap_add(&ca->alloc_heap, e, bucket_alloc_cmp); + if (heap_full(&ca->alloc_heap)) + break; + } + + cond_resched(); + } while (ca->fifo_last_bucket != start); +} + +static void find_reclaimable_buckets_random(struct bch_fs *c, struct bch_dev *ca) +{ + struct bucket_array *buckets = bucket_array(ca); + struct bucket_mark m; + size_t checked, i; + + for (checked = 0; + checked < ca->mi.nbuckets / 2; + checked++) { + size_t b = bch2_rand_range(ca->mi.nbuckets - + ca->mi.first_bucket) + + ca->mi.first_bucket; + + m = READ_ONCE(buckets->b[b].mark); + + if (bch2_can_invalidate_bucket(ca, b, m)) { + struct alloc_heap_entry e = { .bucket = b, .nr = 1, }; + + heap_add(&ca->alloc_heap, e, bucket_alloc_cmp); + if (heap_full(&ca->alloc_heap)) + break; + } + + cond_resched(); + } + + sort(ca->alloc_heap.data, + ca->alloc_heap.used, + sizeof(ca->alloc_heap.data[0]), + bucket_idx_cmp, NULL); + + /* remove duplicates: */ + for (i = 0; i + 1 < ca->alloc_heap.used; i++) + if (ca->alloc_heap.data[i].bucket == + ca->alloc_heap.data[i + 1].bucket) + ca->alloc_heap.data[i].nr = 0; +} + +static size_t find_reclaimable_buckets(struct bch_fs *c, struct bch_dev *ca) +{ + size_t i, nr = 0; + + ca->inc_gen_needs_gc = 0; + + switch (ca->mi.replacement) { + case CACHE_REPLACEMENT_LRU: + find_reclaimable_buckets_lru(c, ca); + break; + case CACHE_REPLACEMENT_FIFO: + find_reclaimable_buckets_fifo(c, ca); + break; + case CACHE_REPLACEMENT_RANDOM: + find_reclaimable_buckets_random(c, ca); + break; + } + + heap_resort(&ca->alloc_heap, bucket_alloc_cmp); + + for (i = 0; i < ca->alloc_heap.used; i++) + nr += ca->alloc_heap.data[i].nr; + + return nr; +} + +static inline long next_alloc_bucket(struct bch_dev *ca) +{ + struct alloc_heap_entry e, *top = ca->alloc_heap.data; + + while (ca->alloc_heap.used) { + if (top->nr) { + size_t b = top->bucket; + + top->bucket++; + top->nr--; + return b; + } + + heap_pop(&ca->alloc_heap, e, bucket_alloc_cmp); + } + + return -1; +} + +static bool bch2_invalidate_one_bucket(struct bch_fs *c, struct bch_dev *ca, + size_t bucket, u64 *flush_seq) +{ + struct bucket_mark m; + + percpu_down_read(&c->usage_lock); + spin_lock(&c->freelist_lock); + + bch2_invalidate_bucket(c, ca, bucket, &m); + + verify_not_on_freelist(c, ca, bucket); + BUG_ON(!fifo_push(&ca->free_inc, bucket)); + + spin_unlock(&c->freelist_lock); + + bucket_io_clock_reset(c, ca, bucket, READ); + bucket_io_clock_reset(c, ca, bucket, WRITE); + + percpu_up_read(&c->usage_lock); + + if (m.journal_seq_valid) { + u64 journal_seq = atomic64_read(&c->journal.seq); + u64 bucket_seq = journal_seq; + + bucket_seq &= ~((u64) U16_MAX); + bucket_seq |= m.journal_seq; + + if (bucket_seq > journal_seq) + bucket_seq -= 1 << 16; + + *flush_seq = max(*flush_seq, bucket_seq); + } + + return m.cached_sectors != 0; +} + +/* + * Pull buckets off ca->alloc_heap, invalidate them, move them to ca->free_inc: + */ +static int bch2_invalidate_buckets(struct bch_fs *c, struct bch_dev *ca) +{ + struct btree_iter iter; + u64 journal_seq = 0; + int ret = 0; + long b; + + bch2_btree_iter_init(&iter, c, BTREE_ID_ALLOC, POS(ca->dev_idx, 0), + BTREE_ITER_SLOTS|BTREE_ITER_INTENT); + + /* Only use nowait if we've already invalidated at least one bucket: */ + while (!ret && + !fifo_full(&ca->free_inc) && + (b = next_alloc_bucket(ca)) >= 0) { + bool must_flush = + bch2_invalidate_one_bucket(c, ca, b, &journal_seq); + + ret = __bch2_alloc_write_key(c, ca, b, &iter, + must_flush ? &journal_seq : NULL, + !fifo_empty(&ca->free_inc) ? BTREE_INSERT_NOWAIT : 0); + } + + bch2_btree_iter_unlock(&iter); + + /* If we used NOWAIT, don't return the error: */ + if (!fifo_empty(&ca->free_inc)) + ret = 0; + if (ret) { + bch_err(ca, "error invalidating buckets: %i", ret); + return ret; + } + + if (journal_seq) + ret = bch2_journal_flush_seq(&c->journal, journal_seq); + if (ret) { + bch_err(ca, "journal error: %i", ret); + return ret; + } + + return 0; +} + +static int push_invalidated_bucket(struct bch_fs *c, struct bch_dev *ca, size_t bucket) +{ + unsigned i; + int ret = 0; + + while (1) { + set_current_state(TASK_INTERRUPTIBLE); + + spin_lock(&c->freelist_lock); + for (i = 0; i < RESERVE_NR; i++) + if (fifo_push(&ca->free[i], bucket)) { + fifo_pop(&ca->free_inc, bucket); + closure_wake_up(&c->freelist_wait); + spin_unlock(&c->freelist_lock); + goto out; + } + spin_unlock(&c->freelist_lock); + + if ((current->flags & PF_KTHREAD) && + kthread_should_stop()) { + ret = 1; + break; + } + + schedule(); + try_to_freeze(); + } +out: + __set_current_state(TASK_RUNNING); + return ret; +} + +/* + * Pulls buckets off free_inc, discards them (if enabled), then adds them to + * freelists, waiting until there's room if necessary: + */ +static int discard_invalidated_buckets(struct bch_fs *c, struct bch_dev *ca) +{ + while (!fifo_empty(&ca->free_inc)) { + size_t bucket = fifo_peek(&ca->free_inc); + + if (ca->mi.discard && + bdev_max_discard_sectors(ca->disk_sb.bdev)) + blkdev_issue_discard(ca->disk_sb.bdev, + bucket_to_sector(ca, bucket), + ca->mi.bucket_size, GFP_NOIO); + + if (push_invalidated_bucket(c, ca, bucket)) + return 1; + } + + return 0; +} + +/** + * bch_allocator_thread - move buckets from free_inc to reserves + * + * The free_inc FIFO is populated by find_reclaimable_buckets(), and + * the reserves are depleted by bucket allocation. When we run out + * of free_inc, try to invalidate some buckets and write out + * prios and gens. + */ +static int bch2_allocator_thread(void *arg) +{ + struct bch_dev *ca = arg; + struct bch_fs *c = ca->fs; + size_t nr; + int ret; + + set_freezable(); + + while (1) { + cond_resched(); + + pr_debug("discarding %zu invalidated buckets", + fifo_used(&ca->free_inc)); + + ret = discard_invalidated_buckets(c, ca); + if (ret) + goto stop; + + down_read(&c->gc_lock); + + ret = bch2_invalidate_buckets(c, ca); + if (ret) { + up_read(&c->gc_lock); + goto stop; + } + + if (!fifo_empty(&ca->free_inc)) { + up_read(&c->gc_lock); + continue; + } + + pr_debug("free_inc now empty"); + + do { + if (test_bit(BCH_FS_GC_FAILURE, &c->flags)) { + up_read(&c->gc_lock); + bch_err(ca, "gc failure"); + goto stop; + } + + /* + * Find some buckets that we can invalidate, either + * they're completely unused, or only contain clean data + * that's been written back to the backing device or + * another cache tier + */ + + pr_debug("scanning for reclaimable buckets"); + + nr = find_reclaimable_buckets(c, ca); + + pr_debug("found %zu buckets", nr); + + trace_alloc_batch(ca, nr, ca->alloc_heap.size); + + if ((ca->inc_gen_needs_gc >= ALLOC_SCAN_BATCH(ca) || + ca->inc_gen_really_needs_gc) && + c->gc_thread) { + atomic_inc(&c->kick_gc); + wake_up_process(c->gc_thread); + } + + /* + * If we found any buckets, we have to invalidate them + * before we scan for more - but if we didn't find very + * many we may want to wait on more buckets being + * available so we don't spin: + */ + if (!nr || + (nr < ALLOC_SCAN_BATCH(ca) && + !fifo_full(&ca->free[RESERVE_MOVINGGC]))) { + ca->allocator_blocked = true; + closure_wake_up(&c->freelist_wait); + + ret = wait_buckets_available(c, ca); + if (ret) { + up_read(&c->gc_lock); + goto stop; + } + } + } while (!nr); + + ca->allocator_blocked = false; + up_read(&c->gc_lock); + + pr_debug("%zu buckets to invalidate", nr); + + /* + * alloc_heap is now full of newly-invalidated buckets: next, + * write out the new bucket gens: + */ + } + +stop: + pr_debug("alloc thread stopping (ret %i)", ret); + return 0; +} + +/* Startup/shutdown (ro/rw): */ + +void bch2_recalc_capacity(struct bch_fs *c) +{ + struct bch_dev *ca; + u64 capacity = 0, reserved_sectors = 0, gc_reserve; + unsigned long ra_pages = 0; + unsigned i, j; + + lockdep_assert_held(&c->state_lock); + + for_each_online_member(ca, c, i) { + struct backing_dev_info *bdi = ca->disk_sb.bdev->bd_disk->bdi; + + ra_pages += bdi->ra_pages; + } + + bch2_set_ra_pages(c, ra_pages); + + for_each_rw_member(ca, c, i) { + u64 dev_reserve = 0; + + /* + * We need to reserve buckets (from the number + * of currently available buckets) against + * foreground writes so that mainly copygc can + * make forward progress. + * + * We need enough to refill the various reserves + * from scratch - copygc will use its entire + * reserve all at once, then run against when + * its reserve is refilled (from the formerly + * available buckets). + * + * This reserve is just used when considering if + * allocations for foreground writes must wait - + * not -ENOSPC calculations. + */ + for (j = 0; j < RESERVE_NONE; j++) + dev_reserve += ca->free[j].size; + + dev_reserve += ca->free_inc.size; + + dev_reserve += ARRAY_SIZE(c->write_points); + + dev_reserve += 1; /* btree write point */ + dev_reserve += 1; /* copygc write point */ + dev_reserve += 1; /* rebalance write point */ + dev_reserve += WRITE_POINT_COUNT; + + dev_reserve *= ca->mi.bucket_size; + + ca->copygc_threshold = dev_reserve; + + capacity += bucket_to_sector(ca, ca->mi.nbuckets - + ca->mi.first_bucket); + + reserved_sectors += dev_reserve * 2; + } + + gc_reserve = c->opts.gc_reserve_bytes + ? c->opts.gc_reserve_bytes >> 9 + : div64_u64(capacity * c->opts.gc_reserve_percent, 100); + + reserved_sectors = max(gc_reserve, reserved_sectors); + + reserved_sectors = min(reserved_sectors, capacity); + + c->capacity = capacity - reserved_sectors; + + if (c->capacity) { + bch2_io_timer_add(&c->io_clock[READ], + &c->bucket_clock[READ].rescale); + bch2_io_timer_add(&c->io_clock[WRITE], + &c->bucket_clock[WRITE].rescale); + } else { + bch2_io_timer_del(&c->io_clock[READ], + &c->bucket_clock[READ].rescale); + bch2_io_timer_del(&c->io_clock[WRITE], + &c->bucket_clock[WRITE].rescale); + } + + /* Wake up case someone was waiting for buckets */ + closure_wake_up(&c->freelist_wait); +} + +static bool bch2_dev_has_open_write_point(struct bch_fs *c, struct bch_dev *ca) +{ + struct open_bucket *ob; + bool ret = false; + + for (ob = c->open_buckets; + ob < c->open_buckets + ARRAY_SIZE(c->open_buckets); + ob++) { + spin_lock(&ob->lock); + if (ob->valid && !ob->on_partial_list && + ob->ptr.dev == ca->dev_idx) + ret = true; + spin_unlock(&ob->lock); + } + + return ret; +} + +/* device goes ro: */ +void bch2_dev_allocator_remove(struct bch_fs *c, struct bch_dev *ca) +{ + unsigned i; + + BUG_ON(ca->alloc_thread); + + /* First, remove device from allocation groups: */ + + for (i = 0; i < ARRAY_SIZE(c->rw_devs); i++) + clear_bit(ca->dev_idx, c->rw_devs[i].d); + + /* + * Capacity is calculated based off of devices in allocation groups: + */ + bch2_recalc_capacity(c); + + /* Next, close write points that point to this device... */ + for (i = 0; i < ARRAY_SIZE(c->write_points); i++) + bch2_writepoint_stop(c, ca, &c->write_points[i]); + + bch2_writepoint_stop(c, ca, &ca->copygc_write_point); + bch2_writepoint_stop(c, ca, &c->rebalance_write_point); + bch2_writepoint_stop(c, ca, &c->btree_write_point); + + mutex_lock(&c->btree_reserve_cache_lock); + while (c->btree_reserve_cache_nr) { + struct btree_alloc *a = + &c->btree_reserve_cache[--c->btree_reserve_cache_nr]; + + bch2_open_bucket_put_refs(c, &a->ob.nr, a->ob.refs); + } + mutex_unlock(&c->btree_reserve_cache_lock); + + /* + * Wake up threads that were blocked on allocation, so they can notice + * the device can no longer be removed and the capacity has changed: + */ + closure_wake_up(&c->freelist_wait); + + /* + * journal_res_get() can block waiting for free space in the journal - + * it needs to notice there may not be devices to allocate from anymore: + */ + wake_up(&c->journal.wait); + + /* Now wait for any in flight writes: */ + + closure_wait_event(&c->open_buckets_wait, + !bch2_dev_has_open_write_point(c, ca)); +} + +/* device goes rw: */ +void bch2_dev_allocator_add(struct bch_fs *c, struct bch_dev *ca) +{ + unsigned i; + + for (i = 0; i < ARRAY_SIZE(c->rw_devs); i++) + if (ca->mi.data_allowed & (1 << i)) + set_bit(ca->dev_idx, c->rw_devs[i].d); +} + +/* stop allocator thread: */ +void bch2_dev_allocator_stop(struct bch_dev *ca) +{ + struct task_struct *p; + + p = rcu_dereference_protected(ca->alloc_thread, 1); + ca->alloc_thread = NULL; + + /* + * We need an rcu barrier between setting ca->alloc_thread = NULL and + * the thread shutting down to avoid bch2_wake_allocator() racing: + * + * XXX: it would be better to have the rcu barrier be asynchronous + * instead of blocking us here + */ + synchronize_rcu(); + + if (p) { + kthread_stop(p); + put_task_struct(p); + } +} + +/* start allocator thread: */ +int bch2_dev_allocator_start(struct bch_dev *ca) +{ + struct task_struct *p; + + /* + * allocator thread already started? + */ + if (ca->alloc_thread) + return 0; + + p = kthread_create(bch2_allocator_thread, ca, + "bch_alloc[%s]", ca->name); + if (IS_ERR(p)) + return PTR_ERR(p); + + get_task_struct(p); + rcu_assign_pointer(ca->alloc_thread, p); + wake_up_process(p); + return 0; +} + +static void flush_held_btree_writes(struct bch_fs *c) +{ + struct bucket_table *tbl; + struct rhash_head *pos; + struct btree *b; + bool flush_updates; + size_t i, nr_pending_updates; + + clear_bit(BCH_FS_HOLD_BTREE_WRITES, &c->flags); +again: + pr_debug("flushing dirty btree nodes"); + cond_resched(); + + flush_updates = false; + nr_pending_updates = bch2_btree_interior_updates_nr_pending(c); + + rcu_read_lock(); + for_each_cached_btree(b, c, tbl, i, pos) + if (btree_node_dirty(b) && (!b->written || b->level)) { + if (btree_node_may_write(b)) { + rcu_read_unlock(); + btree_node_lock_type(c, b, SIX_LOCK_read); + bch2_btree_node_write(c, b, SIX_LOCK_read); + six_unlock_read(&b->lock); + goto again; + } else { + flush_updates = true; + } + } + rcu_read_unlock(); + + if (c->btree_roots_dirty) + bch2_journal_meta(&c->journal); + + /* + * This is ugly, but it's needed to flush btree node writes + * without spinning... + */ + if (flush_updates) { + closure_wait_event(&c->btree_interior_update_wait, + bch2_btree_interior_updates_nr_pending(c) < + nr_pending_updates); + goto again; + } + +} + +static void allocator_start_issue_discards(struct bch_fs *c) +{ + struct bch_dev *ca; + unsigned dev_iter; + size_t bu; + + for_each_rw_member(ca, c, dev_iter) + while (fifo_pop(&ca->free_inc, bu)) + blkdev_issue_discard(ca->disk_sb.bdev, + bucket_to_sector(ca, bu), + ca->mi.bucket_size, GFP_NOIO); +} + +static int __bch2_fs_allocator_start(struct bch_fs *c) +{ + struct bch_dev *ca; + unsigned dev_iter; + u64 journal_seq = 0; + long bu; + bool invalidating_data = false; + int ret = 0; + + if (test_bit(BCH_FS_GC_FAILURE, &c->flags)) + return -1; + + if (test_alloc_startup(c)) { + invalidating_data = true; + goto not_enough; + } + + /* Scan for buckets that are already invalidated: */ + for_each_rw_member(ca, c, dev_iter) { + struct btree_iter iter; + struct bucket_mark m; + struct bkey_s_c k; + + for_each_btree_key(&iter, c, BTREE_ID_ALLOC, POS(ca->dev_idx, 0), 0, k) { + if (k.k->type != BCH_ALLOC) + continue; + + bu = k.k->p.offset; + m = READ_ONCE(bucket(ca, bu)->mark); + + if (!is_available_bucket(m) || m.cached_sectors) + continue; + + percpu_down_read(&c->usage_lock); + bch2_mark_alloc_bucket(c, ca, bu, true, + gc_pos_alloc(c, NULL), + BCH_BUCKET_MARK_MAY_MAKE_UNAVAILABLE| + BCH_BUCKET_MARK_GC_LOCK_HELD); + percpu_up_read(&c->usage_lock); + + fifo_push(&ca->free_inc, bu); + + if (fifo_full(&ca->free_inc)) + break; + } + bch2_btree_iter_unlock(&iter); + } + + /* did we find enough buckets? */ + for_each_rw_member(ca, c, dev_iter) + if (fifo_used(&ca->free_inc) < ca->free[RESERVE_BTREE].size) { + percpu_ref_put(&ca->io_ref); + goto not_enough; + } + + return 0; +not_enough: + pr_debug("did not find enough empty buckets; issuing discards"); + + /* clear out free_inc, we'll be using it again below: */ + for_each_rw_member(ca, c, dev_iter) + discard_invalidated_buckets(c, ca); + + pr_debug("scanning for reclaimable buckets"); + + for_each_rw_member(ca, c, dev_iter) { + find_reclaimable_buckets(c, ca); + + while (!fifo_full(&ca->free[RESERVE_BTREE]) && + (bu = next_alloc_bucket(ca)) >= 0) { + invalidating_data |= + bch2_invalidate_one_bucket(c, ca, bu, &journal_seq); + + fifo_push(&ca->free[RESERVE_BTREE], bu); + set_bit(bu, ca->buckets_dirty); + } + } + + pr_debug("done scanning for reclaimable buckets"); + + /* + * We're moving buckets to freelists _before_ they've been marked as + * invalidated on disk - we have to so that we can allocate new btree + * nodes to mark them as invalidated on disk. + * + * However, we can't _write_ to any of these buckets yet - they might + * have cached data in them, which is live until they're marked as + * invalidated on disk: + */ + if (invalidating_data) { + BUG(); + pr_info("holding writes"); + pr_debug("invalidating existing data"); + set_bit(BCH_FS_HOLD_BTREE_WRITES, &c->flags); + } else { + pr_debug("issuing discards"); + allocator_start_issue_discards(c); + } + + /* + * XXX: it's possible for this to deadlock waiting on journal reclaim, + * since we're holding btree writes. What then? + */ + ret = bch2_alloc_write(c); + if (ret) + return ret; + + if (invalidating_data) { + pr_debug("flushing journal"); + + ret = bch2_journal_flush_seq(&c->journal, journal_seq); + if (ret) + return ret; + + pr_debug("issuing discards"); + allocator_start_issue_discards(c); + } + + set_bit(BCH_FS_ALLOCATOR_STARTED, &c->flags); + + /* now flush dirty btree nodes: */ + if (invalidating_data) + flush_held_btree_writes(c); + + return 0; +} + +int bch2_fs_allocator_start(struct bch_fs *c) +{ + struct bch_dev *ca; + unsigned i; + int ret; + + down_read(&c->gc_lock); + ret = __bch2_fs_allocator_start(c); + up_read(&c->gc_lock); + + if (ret) + return ret; + + for_each_rw_member(ca, c, i) { + ret = bch2_dev_allocator_start(ca); + if (ret) { + percpu_ref_put(&ca->io_ref); + return ret; + } + } + + return bch2_alloc_write(c); +} + +void bch2_fs_allocator_init(struct bch_fs *c) +{ + struct open_bucket *ob; + struct write_point *wp; + + mutex_init(&c->write_points_hash_lock); + spin_lock_init(&c->freelist_lock); + bch2_bucket_clock_init(c, READ); + bch2_bucket_clock_init(c, WRITE); + + /* open bucket 0 is a sentinal NULL: */ + spin_lock_init(&c->open_buckets[0].lock); + + for (ob = c->open_buckets + 1; + ob < c->open_buckets + ARRAY_SIZE(c->open_buckets); ob++) { + spin_lock_init(&ob->lock); + c->open_buckets_nr_free++; + + ob->freelist = c->open_buckets_freelist; + c->open_buckets_freelist = ob - c->open_buckets; + } + + writepoint_init(&c->btree_write_point, BCH_DATA_BTREE); + writepoint_init(&c->rebalance_write_point, BCH_DATA_USER); + + for (wp = c->write_points; + wp < c->write_points + ARRAY_SIZE(c->write_points); wp++) { + writepoint_init(wp, BCH_DATA_USER); + + wp->last_used = sched_clock(); + wp->write_point = (unsigned long) wp; + hlist_add_head_rcu(&wp->node, writepoint_hash(c, wp->write_point)); + } + + c->pd_controllers_update_seconds = 5; + INIT_DELAYED_WORK(&c->pd_controllers_update, pd_controllers_update); +} -- cgit v1.2.3