bcachefs: Initial commit
Initially forked from drivers/md/bcache, bcachefs is a new copy-on-write
filesystem with every feature you could possibly want.
Website: https://bcachefs.org
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
diff --git a/fs/bcachefs/alloc.c b/fs/bcachefs/alloc.c
new file mode 100644
index 0000000..e6e506e
--- /dev/null
+++ b/fs/bcachefs/alloc.c
@@ -0,0 +1,2205 @@
+/*
+ * Primary bucket allocation code
+ *
+ * Copyright 2012 Google, Inc.
+ *
+ * Allocation in bcache is done in terms of buckets:
+ *
+ * Each bucket has associated an 8 bit gen; this gen corresponds to the gen in
+ * btree pointers - they must match for the pointer to be considered valid.
+ *
+ * Thus (assuming a bucket has no dirty data or metadata in it) we can reuse a
+ * bucket simply by incrementing its gen.
+ *
+ * The gens (along with the priorities; it's really the gens are important but
+ * the code is named as if it's the priorities) are written in an arbitrary list
+ * of buckets on disk, with a pointer to them in the journal header.
+ *
+ * When we invalidate a bucket, we have to write its new gen to disk and wait
+ * for that write to complete before we use it - otherwise after a crash we
+ * could have pointers that appeared to be good but pointed to data that had
+ * been overwritten.
+ *
+ * Since the gens and priorities are all stored contiguously on disk, we can
+ * batch this up: We fill up the free_inc list with freshly invalidated buckets,
+ * call prio_write(), and when prio_write() finishes we pull buckets off the
+ * free_inc list and optionally discard them.
+ *
+ * free_inc isn't the only freelist - if it was, we'd often have to sleep while
+ * priorities and gens were being written before we could allocate. c->free is a
+ * smaller freelist, and buckets on that list are always ready to be used.
+ *
+ * If we've got discards enabled, that happens when a bucket moves from the
+ * free_inc list to the free list.
+ *
+ * It's important to ensure that gens don't wrap around - with respect to
+ * either the oldest gen in the btree or the gen on disk. This is quite
+ * difficult to do in practice, but we explicitly guard against it anyways - if
+ * a bucket is in danger of wrapping around we simply skip invalidating it that
+ * time around, and we garbage collect or rewrite the priorities sooner than we
+ * would have otherwise.
+ *
+ * bch2_bucket_alloc() allocates a single bucket from a specific device.
+ *
+ * bch2_bucket_alloc_set() allocates one or more buckets from different devices
+ * in a given filesystem.
+ *
+ * invalidate_buckets() drives all the processes described above. It's called
+ * from bch2_bucket_alloc() and a few other places that need to make sure free
+ * buckets are ready.
+ *
+ * invalidate_buckets_(lru|fifo)() find buckets that are available to be
+ * invalidated, and then invalidate them and stick them on the free_inc list -
+ * in either lru or fifo order.
+ */
+
+#include "bcachefs.h"
+#include "alloc.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 "checksum.h"
+#include "clock.h"
+#include "debug.h"
+#include "disk_groups.h"
+#include "error.h"
+#include "extents.h"
+#include "io.h"
+#include "journal.h"
+#include "journal_io.h"
+#include "super-io.h"
+#include "trace.h"
+
+#include <linux/blkdev.h>
+#include <linux/kthread.h>
+#include <linux/math64.h>
+#include <linux/random.h>
+#include <linux/rculist.h>
+#include <linux/rcupdate.h>
+#include <linux/sched/task.h>
+#include <linux/sort.h>
+
+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;
+}
+
+void 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;
+ }
+}
+
+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, bool nowait)
+{
+ 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;
+ int ret;
+ unsigned flags = BTREE_INSERT_ATOMIC|
+ BTREE_INSERT_NOFAIL|
+ BTREE_INSERT_USE_RESERVE|
+ BTREE_INSERT_USE_ALLOC_RESERVE;
+
+ if (nowait)
+ flags |= BTREE_INSERT_NOWAIT;
+
+ bch2_btree_iter_set_pos(iter, POS(ca->dev_idx, b));
+
+ do {
+ ret = btree_iter_err(bch2_btree_iter_peek_slot(iter));
+ if (ret)
+ break;
+
+ percpu_down_read(&c->usage_lock);
+ g = bucket(ca, b);
+
+ /* read mark under btree node lock: */
+ m = READ_ONCE(g->mark);
+ a = bkey_alloc_init(&alloc_key.k);
+ a->k.p = iter->pos;
+ 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);
+
+ ret = bch2_btree_insert_at(c, NULL, NULL, journal_seq, flags,
+ BTREE_INSERT_ENTRY(iter, &a->k_i));
+ bch2_btree_iter_cond_resched(iter);
+ } while (ret == -EINTR);
+
+ return ret;
+}
+
+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, false);
+ 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, false);
+ 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.
+ */
+
+static void verify_not_on_freelist(struct bch_fs *c, struct bch_dev *ca,
+ size_t bucket)
+{
+ if (expensive_debug_checks(c) &&
+ test_bit(BCH_FS_ALLOCATOR_STARTED, &c->flags)) {
+ size_t iter;
+ long i;
+ unsigned j;
+
+ for (j = 0; j < RESERVE_NR; j++)
+ fifo_for_each_entry(i, &ca->free[j], iter)
+ BUG_ON(i == bucket);
+ fifo_for_each_entry(i, &ca->free_inc, iter)
+ BUG_ON(i == bucket);
+ }
+}
+
+#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;
+}
+
+static void bch2_invalidate_one_bucket(struct bch_fs *c, struct bch_dev *ca,
+ size_t bucket)
+{
+ struct bucket_mark m;
+
+ percpu_down_read(&c->usage_lock);
+ spin_lock(&c->freelist_lock);
+
+ if (!bch2_invalidate_bucket(c, ca, bucket, &m)) {
+ spin_unlock(&c->freelist_lock);
+ percpu_up_read(&c->usage_lock);
+ return;
+ }
+
+ verify_not_on_freelist(c, ca, bucket);
+ BUG_ON(!fifo_push(&ca->free_inc, bucket));
+
+ spin_unlock(&c->freelist_lock);
+ percpu_up_read(&c->usage_lock);
+
+ /* gc lock held: */
+ bucket_io_clock_reset(c, ca, bucket, READ);
+ bucket_io_clock_reset(c, ca, bucket, WRITE);
+
+ if (m.cached_sectors) {
+ ca->allocator_invalidating_data = true;
+ } else 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;
+
+ ca->allocator_journal_seq_flush =
+ max(ca->allocator_journal_seq_flush, bucket_seq);
+ }
+}
+
+/*
+ * 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);
+}
+
+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 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;
+
+ 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);
+
+ up_read(&ca->bucket_lock);
+ mutex_unlock(&c->bucket_clock[READ].lock);
+
+ heap_resort(&ca->alloc_heap, bucket_alloc_cmp);
+
+ while (heap_pop(&ca->alloc_heap, e, bucket_alloc_cmp)) {
+ for (b = e.bucket;
+ b < e.bucket + e.nr;
+ b++) {
+ if (fifo_full(&ca->free_inc))
+ return;
+
+ bch2_invalidate_one_bucket(c, ca, b);
+ }
+ }
+}
+
+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, checked;
+
+ for (checked = 0;
+ checked < ca->mi.nbuckets && !fifo_full(&ca->free_inc);
+ checked++) {
+ if (ca->fifo_last_bucket < ca->mi.first_bucket ||
+ 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))
+ bch2_invalidate_one_bucket(c, ca, b);
+
+ cond_resched();
+ }
+}
+
+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;
+
+ for (checked = 0;
+ checked < ca->mi.nbuckets / 2 && !fifo_full(&ca->free_inc);
+ 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))
+ bch2_invalidate_one_bucket(c, ca, b);
+
+ cond_resched();
+ }
+}
+
+static void find_reclaimable_buckets(struct bch_fs *c, struct bch_dev *ca)
+{
+ ca->inc_gen_needs_gc = 0;
+ ca->inc_gen_really_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;
+ }
+}
+
+static int size_t_cmp(const void *_l, const void *_r)
+{
+ const size_t *l = _l, *r = _r;
+
+ return (*l > *r) - (*l < *r);
+}
+
+static void sort_free_inc(struct bch_fs *c, struct bch_dev *ca)
+{
+ BUG_ON(ca->free_inc.front);
+
+ spin_lock(&c->freelist_lock);
+ sort(ca->free_inc.data,
+ ca->free_inc.back,
+ sizeof(ca->free_inc.data[0]),
+ size_t_cmp, NULL);
+ spin_unlock(&c->freelist_lock);
+}
+
+static int bch2_invalidate_free_inc(struct bch_fs *c, struct bch_dev *ca,
+ u64 *journal_seq, size_t nr,
+ bool nowait)
+{
+ struct btree_iter iter;
+ int ret = 0;
+
+ 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 (ca->nr_invalidated < min(nr, fifo_used(&ca->free_inc))) {
+ size_t b = fifo_idx_entry(&ca->free_inc, ca->nr_invalidated);
+
+ ret = __bch2_alloc_write_key(c, ca, b, &iter, journal_seq,
+ nowait && ca->nr_invalidated);
+ if (ret)
+ break;
+
+ ca->nr_invalidated++;
+ }
+
+ bch2_btree_iter_unlock(&iter);
+
+ /* If we used NOWAIT, don't return the error: */
+ return ca->nr_invalidated ? 0 : ret;
+}
+
+static bool __push_invalidated_bucket(struct bch_fs *c, struct bch_dev *ca, size_t bucket)
+{
+ unsigned i;
+
+ /*
+ * Don't remove from free_inc until after it's added to
+ * freelist, so gc can find it:
+ */
+ 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);
+ --ca->nr_invalidated;
+ closure_wake_up(&c->freelist_wait);
+ spin_unlock(&c->freelist_lock);
+ return true;
+ }
+ spin_unlock(&c->freelist_lock);
+
+ return false;
+}
+
+static int push_invalidated_bucket(struct bch_fs *c, struct bch_dev *ca, size_t bucket)
+{
+ int ret = 0;
+
+ while (1) {
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ if (__push_invalidated_bucket(c, ca, bucket))
+ break;
+
+ if ((current->flags & PF_KTHREAD) &&
+ kthread_should_stop()) {
+ ret = 1;
+ break;
+ }
+
+ schedule();
+ try_to_freeze();
+ }
+
+ __set_current_state(TASK_RUNNING);
+ return ret;
+}
+
+/*
+ * Given an invalidated, ready to use bucket: issue a discard to it if enabled,
+ * then add it to the freelist, waiting until there's room if necessary:
+ */
+static int discard_invalidated_buckets(struct bch_fs *c, struct bch_dev *ca)
+{
+ while (ca->nr_invalidated) {
+ size_t bucket = fifo_peek(&ca->free_inc);
+
+ BUG_ON(fifo_empty(&ca->free_inc) || !ca->nr_invalidated);
+
+ 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;
+ u64 journal_seq;
+ int ret;
+
+ set_freezable();
+
+ while (1) {
+ while (1) {
+ cond_resched();
+
+ pr_debug("discarding %zu invalidated buckets",
+ ca->nr_invalidated);
+
+ ret = discard_invalidated_buckets(c, ca);
+ if (ret)
+ goto stop;
+
+ if (fifo_empty(&ca->free_inc))
+ break;
+
+ pr_debug("invalidating %zu buckets",
+ fifo_used(&ca->free_inc));
+
+ journal_seq = 0;
+ ret = bch2_invalidate_free_inc(c, ca, &journal_seq,
+ SIZE_MAX, true);
+ if (ret) {
+ bch_err(ca, "error invalidating buckets: %i", ret);
+ goto stop;
+ }
+
+ if (!ca->nr_invalidated) {
+ bch_err(ca, "allocator thread unable to make forward progress!");
+ goto stop;
+ }
+
+ if (ca->allocator_invalidating_data)
+ ret = bch2_journal_flush_seq(&c->journal, journal_seq);
+ else if (ca->allocator_journal_seq_flush)
+ ret = bch2_journal_flush_seq(&c->journal,
+ ca->allocator_journal_seq_flush);
+
+ /*
+ * journal error - buckets haven't actually been
+ * invalidated, can't discard them:
+ */
+ if (ret) {
+ bch_err(ca, "journal error: %i", ret);
+ goto stop;
+ }
+ }
+
+ pr_debug("free_inc now empty");
+
+ /* Reset front/back so we can easily sort fifo entries later: */
+ ca->free_inc.front = ca->free_inc.back = 0;
+ ca->allocator_journal_seq_flush = 0;
+ ca->allocator_invalidating_data = false;
+
+ down_read(&c->gc_lock);
+ while (1) {
+ size_t prev = fifo_used(&ca->free_inc);
+
+ 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");
+
+ find_reclaimable_buckets(c, ca);
+
+ pr_debug("found %zu buckets (free_inc %zu/%zu)",
+ fifo_used(&ca->free_inc) - prev,
+ fifo_used(&ca->free_inc), ca->free_inc.size);
+
+ trace_alloc_batch(ca, fifo_used(&ca->free_inc),
+ ca->free_inc.size);
+
+ if ((ca->inc_gen_needs_gc >= ca->free_inc.size ||
+ (!fifo_full(&ca->free_inc) &&
+ ca->inc_gen_really_needs_gc >=
+ fifo_free(&ca->free_inc))) &&
+ c->gc_thread) {
+ atomic_inc(&c->kick_gc);
+ wake_up_process(c->gc_thread);
+ }
+
+ if (fifo_full(&ca->free_inc))
+ break;
+
+ if (!fifo_empty(&ca->free_inc) &&
+ !fifo_full(&ca->free[RESERVE_MOVINGGC]))
+ break;
+
+ /*
+ * copygc may be waiting until either its reserve fills
+ * up, or we can't make forward progress:
+ */
+ 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;
+ }
+ }
+
+ ca->allocator_blocked = false;
+ up_read(&c->gc_lock);
+
+ pr_debug("free_inc now %zu/%zu",
+ fifo_used(&ca->free_inc),
+ ca->free_inc.size);
+
+ sort_free_inc(c, ca);
+
+ /*
+ * free_inc 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;
+}
+
+/* Allocation */
+
+/*
+ * Open buckets represent a bucket that's currently being allocated from. They
+ * serve two purposes:
+ *
+ * - They track buckets that have been partially allocated, allowing for
+ * sub-bucket sized allocations - they're used by the sector allocator below
+ *
+ * - They provide a reference to the buckets they own that mark and sweep GC
+ * can find, until the new allocation has a pointer to it inserted into the
+ * btree
+ *
+ * When allocating some space with the sector allocator, the allocation comes
+ * with a reference to an open bucket - the caller is required to put that
+ * reference _after_ doing the index update that makes its allocation reachable.
+ */
+
+void __bch2_open_bucket_put(struct bch_fs *c, struct open_bucket *ob)
+{
+ struct bch_dev *ca = bch_dev_bkey_exists(c, ob->ptr.dev);
+
+ percpu_down_read(&c->usage_lock);
+ spin_lock(&ob->lock);
+
+ bch2_mark_alloc_bucket(c, ca, PTR_BUCKET_NR(ca, &ob->ptr),
+ false, gc_pos_alloc(c, ob), 0);
+ ob->valid = false;
+
+ spin_unlock(&ob->lock);
+ percpu_up_read(&c->usage_lock);
+
+ spin_lock(&c->freelist_lock);
+ ob->freelist = c->open_buckets_freelist;
+ c->open_buckets_freelist = ob - c->open_buckets;
+ c->open_buckets_nr_free++;
+ spin_unlock(&c->freelist_lock);
+
+ closure_wake_up(&c->open_buckets_wait);
+}
+
+static struct open_bucket *bch2_open_bucket_alloc(struct bch_fs *c)
+{
+ struct open_bucket *ob;
+
+ BUG_ON(!c->open_buckets_freelist || !c->open_buckets_nr_free);
+
+ ob = c->open_buckets + c->open_buckets_freelist;
+ c->open_buckets_freelist = ob->freelist;
+ atomic_set(&ob->pin, 1);
+
+ c->open_buckets_nr_free--;
+ return ob;
+}
+
+/* _only_ for allocating the journal on a new device: */
+long bch2_bucket_alloc_new_fs(struct bch_dev *ca)
+{
+ struct bucket_array *buckets;
+ ssize_t b;
+
+ rcu_read_lock();
+ buckets = bucket_array(ca);
+
+ for (b = ca->mi.first_bucket; b < ca->mi.nbuckets; b++)
+ if (is_available_bucket(buckets->b[b].mark))
+ goto success;
+ b = -1;
+success:
+ rcu_read_unlock();
+ return b;
+}
+
+static inline unsigned open_buckets_reserved(enum alloc_reserve reserve)
+{
+ switch (reserve) {
+ case RESERVE_ALLOC:
+ return 0;
+ case RESERVE_BTREE:
+ return BTREE_NODE_RESERVE / 2;
+ default:
+ return BTREE_NODE_RESERVE;
+ }
+}
+
+/**
+ * bch_bucket_alloc - allocate a single bucket from a specific device
+ *
+ * Returns index of bucket on success, 0 on failure
+ * */
+int bch2_bucket_alloc(struct bch_fs *c, struct bch_dev *ca,
+ enum alloc_reserve reserve,
+ bool may_alloc_partial,
+ struct closure *cl)
+{
+ struct bucket_array *buckets;
+ struct open_bucket *ob;
+ long bucket;
+
+ spin_lock(&c->freelist_lock);
+
+ if (may_alloc_partial &&
+ ca->open_buckets_partial_nr) {
+ int ret = ca->open_buckets_partial[--ca->open_buckets_partial_nr];
+ c->open_buckets[ret].on_partial_list = false;
+ spin_unlock(&c->freelist_lock);
+ return ret;
+ }
+
+ if (unlikely(c->open_buckets_nr_free <= open_buckets_reserved(reserve))) {
+ if (cl)
+ closure_wait(&c->open_buckets_wait, cl);
+ spin_unlock(&c->freelist_lock);
+ trace_open_bucket_alloc_fail(ca, reserve);
+ return OPEN_BUCKETS_EMPTY;
+ }
+
+ if (likely(fifo_pop(&ca->free[RESERVE_NONE], bucket)))
+ goto out;
+
+ switch (reserve) {
+ case RESERVE_ALLOC:
+ if (fifo_pop(&ca->free[RESERVE_BTREE], bucket))
+ goto out;
+ break;
+ case RESERVE_BTREE:
+ if (fifo_used(&ca->free[RESERVE_BTREE]) * 2 >=
+ ca->free[RESERVE_BTREE].size &&
+ fifo_pop(&ca->free[RESERVE_BTREE], bucket))
+ goto out;
+ break;
+ case RESERVE_MOVINGGC:
+ if (fifo_pop(&ca->free[RESERVE_MOVINGGC], bucket))
+ goto out;
+ break;
+ default:
+ break;
+ }
+
+ if (cl)
+ closure_wait(&c->freelist_wait, cl);
+
+ spin_unlock(&c->freelist_lock);
+
+ trace_bucket_alloc_fail(ca, reserve);
+ return FREELIST_EMPTY;
+out:
+ verify_not_on_freelist(c, ca, bucket);
+
+ ob = bch2_open_bucket_alloc(c);
+
+ spin_lock(&ob->lock);
+ buckets = bucket_array(ca);
+
+ ob->valid = true;
+ ob->sectors_free = ca->mi.bucket_size;
+ ob->ptr = (struct bch_extent_ptr) {
+ .gen = buckets->b[bucket].mark.gen,
+ .offset = bucket_to_sector(ca, bucket),
+ .dev = ca->dev_idx,
+ };
+
+ bucket_io_clock_reset(c, ca, bucket, READ);
+ bucket_io_clock_reset(c, ca, bucket, WRITE);
+ spin_unlock(&ob->lock);
+
+ spin_unlock(&c->freelist_lock);
+
+ bch2_wake_allocator(ca);
+
+ trace_bucket_alloc(ca, reserve);
+ return ob - c->open_buckets;
+}
+
+static int __dev_alloc_cmp(struct write_point *wp,
+ unsigned l, unsigned r)
+{
+ return ((wp->next_alloc[l] > wp->next_alloc[r]) -
+ (wp->next_alloc[l] < wp->next_alloc[r]));
+}
+
+#define dev_alloc_cmp(l, r) __dev_alloc_cmp(wp, l, r)
+
+struct dev_alloc_list bch2_wp_alloc_list(struct bch_fs *c,
+ struct write_point *wp,
+ struct bch_devs_mask *devs)
+{
+ struct dev_alloc_list ret = { .nr = 0 };
+ struct bch_dev *ca;
+ unsigned i;
+
+ for_each_member_device_rcu(ca, c, i, devs)
+ ret.devs[ret.nr++] = i;
+
+ bubble_sort(ret.devs, ret.nr, dev_alloc_cmp);
+ return ret;
+}
+
+void bch2_wp_rescale(struct bch_fs *c, struct bch_dev *ca,
+ struct write_point *wp)
+{
+ u64 *v = wp->next_alloc + ca->dev_idx;
+ u64 free_space = dev_buckets_free(c, ca);
+ u64 free_space_inv = free_space
+ ? div64_u64(1ULL << 48, free_space)
+ : 1ULL << 48;
+ u64 scale = *v / 4;
+
+ if (*v + free_space_inv >= *v)
+ *v += free_space_inv;
+ else
+ *v = U64_MAX;
+
+ for (v = wp->next_alloc;
+ v < wp->next_alloc + ARRAY_SIZE(wp->next_alloc); v++)
+ *v = *v < scale ? 0 : *v - scale;
+}
+
+static enum bucket_alloc_ret bch2_bucket_alloc_set(struct bch_fs *c,
+ struct write_point *wp,
+ unsigned nr_replicas,
+ enum alloc_reserve reserve,
+ struct bch_devs_mask *devs,
+ struct closure *cl)
+{
+ enum bucket_alloc_ret ret = NO_DEVICES;
+ struct dev_alloc_list devs_sorted;
+ struct bch_dev *ca;
+ unsigned i, nr_ptrs_effective = 0;
+ bool have_cache_dev = false;
+
+ BUG_ON(nr_replicas > ARRAY_SIZE(wp->ptrs));
+
+ for (i = wp->first_ptr; i < wp->nr_ptrs; i++) {
+ ca = bch_dev_bkey_exists(c, wp->ptrs[i]->ptr.dev);
+
+ nr_ptrs_effective += ca->mi.durability;
+ have_cache_dev |= !ca->mi.durability;
+ }
+
+ if (nr_ptrs_effective >= nr_replicas)
+ return ALLOC_SUCCESS;
+
+ devs_sorted = bch2_wp_alloc_list(c, wp, devs);
+
+ for (i = 0; i < devs_sorted.nr; i++) {
+ int ob;
+
+ ca = rcu_dereference(c->devs[devs_sorted.devs[i]]);
+ if (!ca)
+ continue;
+
+ if (!ca->mi.durability &&
+ (have_cache_dev ||
+ wp->type != BCH_DATA_USER))
+ continue;
+
+ ob = bch2_bucket_alloc(c, ca, reserve,
+ wp->type == BCH_DATA_USER, cl);
+ if (ob < 0) {
+ ret = ob;
+ if (ret == OPEN_BUCKETS_EMPTY)
+ break;
+ continue;
+ }
+
+ BUG_ON(ob <= 0 || ob > U8_MAX);
+ BUG_ON(wp->nr_ptrs >= ARRAY_SIZE(wp->ptrs));
+
+ wp->ptrs[wp->nr_ptrs++] = c->open_buckets + ob;
+
+ bch2_wp_rescale(c, ca, wp);
+
+ nr_ptrs_effective += ca->mi.durability;
+ have_cache_dev |= !ca->mi.durability;
+
+ __clear_bit(ca->dev_idx, devs->d);
+
+ if (nr_ptrs_effective >= nr_replicas) {
+ ret = ALLOC_SUCCESS;
+ break;
+ }
+ }
+
+ EBUG_ON(reserve == RESERVE_MOVINGGC &&
+ ret != ALLOC_SUCCESS &&
+ ret != OPEN_BUCKETS_EMPTY);
+
+ switch (ret) {
+ case ALLOC_SUCCESS:
+ return 0;
+ case NO_DEVICES:
+ return -EROFS;
+ case FREELIST_EMPTY:
+ case OPEN_BUCKETS_EMPTY:
+ return cl ? -EAGAIN : -ENOSPC;
+ default:
+ BUG();
+ }
+}
+
+/* Sector allocator */
+
+static void writepoint_drop_ptr(struct bch_fs *c,
+ struct write_point *wp,
+ unsigned i)
+{
+ struct open_bucket *ob = wp->ptrs[i];
+ struct bch_dev *ca = bch_dev_bkey_exists(c, ob->ptr.dev);
+
+ BUG_ON(ca->open_buckets_partial_nr >=
+ ARRAY_SIZE(ca->open_buckets_partial));
+
+ if (wp->type == BCH_DATA_USER) {
+ spin_lock(&c->freelist_lock);
+ ob->on_partial_list = true;
+ ca->open_buckets_partial[ca->open_buckets_partial_nr++] =
+ ob - c->open_buckets;
+ spin_unlock(&c->freelist_lock);
+
+ closure_wake_up(&c->open_buckets_wait);
+ closure_wake_up(&c->freelist_wait);
+ } else {
+ bch2_open_bucket_put(c, ob);
+ }
+
+ array_remove_item(wp->ptrs, wp->nr_ptrs, i);
+
+ if (i < wp->first_ptr)
+ wp->first_ptr--;
+}
+
+static void writepoint_drop_ptrs(struct bch_fs *c,
+ struct write_point *wp,
+ u16 target, bool in_target)
+{
+ int i;
+
+ for (i = wp->first_ptr - 1; i >= 0; --i)
+ if (bch2_dev_in_target(c, wp->ptrs[i]->ptr.dev,
+ target) == in_target)
+ writepoint_drop_ptr(c, wp, i);
+}
+
+static void verify_not_stale(struct bch_fs *c, const struct write_point *wp)
+{
+#ifdef CONFIG_BCACHEFS_DEBUG
+ struct open_bucket *ob;
+ unsigned i;
+
+ writepoint_for_each_ptr_all(wp, ob, i) {
+ struct bch_dev *ca = bch_dev_bkey_exists(c, ob->ptr.dev);
+
+ BUG_ON(ptr_stale(ca, &ob->ptr));
+ }
+#endif
+}
+
+static int open_bucket_add_buckets(struct bch_fs *c,
+ u16 target,
+ struct write_point *wp,
+ struct bch_devs_list *devs_have,
+ unsigned nr_replicas,
+ enum alloc_reserve reserve,
+ struct closure *cl)
+{
+ struct bch_devs_mask devs = c->rw_devs[wp->type];
+ const struct bch_devs_mask *t;
+ struct open_bucket *ob;
+ unsigned i;
+ int ret;
+
+ percpu_down_read(&c->usage_lock);
+ rcu_read_lock();
+
+ /* Don't allocate from devices we already have pointers to: */
+ for (i = 0; i < devs_have->nr; i++)
+ __clear_bit(devs_have->devs[i], devs.d);
+
+ writepoint_for_each_ptr_all(wp, ob, i)
+ __clear_bit(ob->ptr.dev, devs.d);
+
+ t = bch2_target_to_mask(c, target);
+ if (t)
+ bitmap_and(devs.d, devs.d, t->d, BCH_SB_MEMBERS_MAX);
+
+ ret = bch2_bucket_alloc_set(c, wp, nr_replicas, reserve, &devs, cl);
+
+ rcu_read_unlock();
+ percpu_up_read(&c->usage_lock);
+
+ return ret;
+}
+
+static struct write_point *__writepoint_find(struct hlist_head *head,
+ unsigned long write_point)
+{
+ struct write_point *wp;
+
+ hlist_for_each_entry_rcu(wp, head, node)
+ if (wp->write_point == write_point)
+ return wp;
+
+ return NULL;
+}
+
+static struct hlist_head *writepoint_hash(struct bch_fs *c,
+ unsigned long write_point)
+{
+ unsigned hash =
+ hash_long(write_point, ilog2(ARRAY_SIZE(c->write_points_hash)));
+
+ return &c->write_points_hash[hash];
+}
+
+static struct write_point *writepoint_find(struct bch_fs *c,
+ unsigned long write_point)
+{
+ struct write_point *wp, *oldest;
+ struct hlist_head *head;
+
+ if (!(write_point & 1UL)) {
+ wp = (struct write_point *) write_point;
+ mutex_lock(&wp->lock);
+ return wp;
+ }
+
+ head = writepoint_hash(c, write_point);
+restart_find:
+ wp = __writepoint_find(head, write_point);
+ if (wp) {
+lock_wp:
+ mutex_lock(&wp->lock);
+ if (wp->write_point == write_point)
+ goto out;
+ mutex_unlock(&wp->lock);
+ goto restart_find;
+ }
+
+ oldest = NULL;
+ for (wp = c->write_points;
+ wp < c->write_points + ARRAY_SIZE(c->write_points);
+ wp++)
+ if (!oldest || time_before64(wp->last_used, oldest->last_used))
+ oldest = wp;
+
+ mutex_lock(&oldest->lock);
+ mutex_lock(&c->write_points_hash_lock);
+ wp = __writepoint_find(head, write_point);
+ if (wp && wp != oldest) {
+ mutex_unlock(&c->write_points_hash_lock);
+ mutex_unlock(&oldest->lock);
+ goto lock_wp;
+ }
+
+ wp = oldest;
+ hlist_del_rcu(&wp->node);
+ wp->write_point = write_point;
+ hlist_add_head_rcu(&wp->node, head);
+ mutex_unlock(&c->write_points_hash_lock);
+out:
+ wp->last_used = sched_clock();
+ return wp;
+}
+
+/*
+ * Get us an open_bucket we can allocate from, return with it locked:
+ */
+struct write_point *bch2_alloc_sectors_start(struct bch_fs *c,
+ unsigned target,
+ struct write_point_specifier write_point,
+ struct bch_devs_list *devs_have,
+ unsigned nr_replicas,
+ unsigned nr_replicas_required,
+ enum alloc_reserve reserve,
+ unsigned flags,
+ struct closure *cl)
+{
+ struct write_point *wp;
+ struct open_bucket *ob;
+ struct bch_dev *ca;
+ unsigned nr_ptrs_have, nr_ptrs_effective;
+ int ret, i, cache_idx = -1;
+
+ BUG_ON(!nr_replicas || !nr_replicas_required);
+
+ wp = writepoint_find(c, write_point.v);
+
+ wp->first_ptr = 0;
+
+ /* does writepoint have ptrs we can't use? */
+ writepoint_for_each_ptr(wp, ob, i)
+ if (bch2_dev_list_has_dev(*devs_have, ob->ptr.dev)) {
+ swap(wp->ptrs[i], wp->ptrs[wp->first_ptr]);
+ wp->first_ptr++;
+ }
+
+ nr_ptrs_have = wp->first_ptr;
+
+ /* does writepoint have ptrs we don't want to use? */
+ if (target)
+ writepoint_for_each_ptr(wp, ob, i)
+ if (!bch2_dev_in_target(c, ob->ptr.dev, target)) {
+ swap(wp->ptrs[i], wp->ptrs[wp->first_ptr]);
+ wp->first_ptr++;
+ }
+
+ if (flags & BCH_WRITE_ONLY_SPECIFIED_DEVS) {
+ ret = open_bucket_add_buckets(c, target, wp, devs_have,
+ nr_replicas, reserve, cl);
+ } else {
+ ret = open_bucket_add_buckets(c, target, wp, devs_have,
+ nr_replicas, reserve, NULL);
+ if (!ret)
+ goto alloc_done;
+
+ wp->first_ptr = nr_ptrs_have;
+
+ ret = open_bucket_add_buckets(c, 0, wp, devs_have,
+ nr_replicas, reserve, cl);
+ }
+
+ if (ret && ret != -EROFS)
+ goto err;
+alloc_done:
+ /* check for more than one cache: */
+ for (i = wp->nr_ptrs - 1; i >= wp->first_ptr; --i) {
+ ca = bch_dev_bkey_exists(c, wp->ptrs[i]->ptr.dev);
+
+ if (ca->mi.durability)
+ continue;
+
+ /*
+ * if we ended up with more than one cache device, prefer the
+ * one in the target we want:
+ */
+ if (cache_idx >= 0) {
+ if (!bch2_dev_in_target(c, wp->ptrs[i]->ptr.dev,
+ target)) {
+ writepoint_drop_ptr(c, wp, i);
+ } else {
+ writepoint_drop_ptr(c, wp, cache_idx);
+ cache_idx = i;
+ }
+ } else {
+ cache_idx = i;
+ }
+ }
+
+ /* we might have more effective replicas than required: */
+ nr_ptrs_effective = 0;
+ writepoint_for_each_ptr(wp, ob, i) {
+ ca = bch_dev_bkey_exists(c, ob->ptr.dev);
+ nr_ptrs_effective += ca->mi.durability;
+ }
+
+ if (ret == -EROFS &&
+ nr_ptrs_effective >= nr_replicas_required)
+ ret = 0;
+
+ if (ret)
+ goto err;
+
+ if (nr_ptrs_effective > nr_replicas) {
+ writepoint_for_each_ptr(wp, ob, i) {
+ ca = bch_dev_bkey_exists(c, ob->ptr.dev);
+
+ if (ca->mi.durability &&
+ ca->mi.durability <= nr_ptrs_effective - nr_replicas &&
+ !bch2_dev_in_target(c, ob->ptr.dev, target)) {
+ swap(wp->ptrs[i], wp->ptrs[wp->first_ptr]);
+ wp->first_ptr++;
+ nr_ptrs_effective -= ca->mi.durability;
+ }
+ }
+ }
+
+ if (nr_ptrs_effective > nr_replicas) {
+ writepoint_for_each_ptr(wp, ob, i) {
+ ca = bch_dev_bkey_exists(c, ob->ptr.dev);
+
+ if (ca->mi.durability &&
+ ca->mi.durability <= nr_ptrs_effective - nr_replicas) {
+ swap(wp->ptrs[i], wp->ptrs[wp->first_ptr]);
+ wp->first_ptr++;
+ nr_ptrs_effective -= ca->mi.durability;
+ }
+ }
+ }
+
+ /* Remove pointers we don't want to use: */
+ if (target)
+ writepoint_drop_ptrs(c, wp, target, false);
+
+ BUG_ON(wp->first_ptr >= wp->nr_ptrs);
+ BUG_ON(nr_ptrs_effective < nr_replicas_required);
+
+ wp->sectors_free = UINT_MAX;
+
+ writepoint_for_each_ptr(wp, ob, i)
+ wp->sectors_free = min(wp->sectors_free, ob->sectors_free);
+
+ BUG_ON(!wp->sectors_free || wp->sectors_free == UINT_MAX);
+
+ verify_not_stale(c, wp);
+
+ return wp;
+err:
+ mutex_unlock(&wp->lock);
+ return ERR_PTR(ret);
+}
+
+/*
+ * Append pointers to the space we just allocated to @k, and mark @sectors space
+ * as allocated out of @ob
+ */
+void bch2_alloc_sectors_append_ptrs(struct bch_fs *c, struct write_point *wp,
+ struct bkey_i_extent *e, unsigned sectors)
+{
+ struct open_bucket *ob;
+ unsigned i;
+
+ BUG_ON(sectors > wp->sectors_free);
+ wp->sectors_free -= sectors;
+
+ writepoint_for_each_ptr(wp, ob, i) {
+ struct bch_dev *ca = bch_dev_bkey_exists(c, ob->ptr.dev);
+ struct bch_extent_ptr tmp = ob->ptr;
+
+ EBUG_ON(bch2_extent_has_device(extent_i_to_s_c(e), ob->ptr.dev));
+
+ tmp.cached = bkey_extent_is_cached(&e->k) ||
+ (!ca->mi.durability && wp->type == BCH_DATA_USER);
+
+ tmp.offset += ca->mi.bucket_size - ob->sectors_free;
+ extent_ptr_append(e, tmp);
+
+ BUG_ON(sectors > ob->sectors_free);
+ ob->sectors_free -= sectors;
+ }
+}
+
+/*
+ * Append pointers to the space we just allocated to @k, and mark @sectors space
+ * as allocated out of @ob
+ */
+void bch2_alloc_sectors_done(struct bch_fs *c, struct write_point *wp)
+{
+ int i;
+
+ for (i = wp->nr_ptrs - 1; i >= 0; --i) {
+ struct open_bucket *ob = wp->ptrs[i];
+
+ if (!ob->sectors_free) {
+ array_remove_item(wp->ptrs, wp->nr_ptrs, i);
+ bch2_open_bucket_put(c, ob);
+ }
+ }
+
+ mutex_unlock(&wp->lock);
+}
+
+/* Startup/shutdown (ro/rw): */
+
+void bch2_recalc_capacity(struct bch_fs *c)
+{
+ struct bch_dev *ca;
+ u64 total_capacity, capacity = 0, reserved_sectors = 0;
+ 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) {
+ size_t 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++)
+ reserve += ca->free[j].size;
+
+ reserve += ca->free_inc.size;
+
+ reserve += ARRAY_SIZE(c->write_points);
+
+ reserve += 1; /* btree write point */
+
+ reserved_sectors += bucket_to_sector(ca, reserve);
+
+ capacity += bucket_to_sector(ca, ca->mi.nbuckets -
+ ca->mi.first_bucket);
+ }
+
+ total_capacity = capacity;
+
+ capacity *= (100 - c->opts.gc_reserve_percent);
+ capacity = div64_u64(capacity, 100);
+
+ BUG_ON(reserved_sectors > total_capacity);
+
+ capacity = min(capacity, total_capacity - reserved_sectors);
+
+ c->capacity = capacity;
+
+ 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 void bch2_stop_write_point(struct bch_fs *c, struct bch_dev *ca,
+ struct write_point *wp)
+{
+ struct bch_devs_mask not_self;
+
+ bitmap_complement(not_self.d, ca->self.d, BCH_SB_MEMBERS_MAX);
+
+ mutex_lock(&wp->lock);
+ wp->first_ptr = wp->nr_ptrs;
+ writepoint_drop_ptrs(c, wp, dev_to_target(ca->dev_idx), true);
+ mutex_unlock(&wp->lock);
+}
+
+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_stop_write_point(c, ca, &c->write_points[i]);
+
+ bch2_stop_write_point(c, ca, &ca->copygc_write_point);
+ bch2_stop_write_point(c, ca, &c->rebalance_write_point);
+ bch2_stop_write_point(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 allocator_start_issue_discards(struct bch_fs *c)
+{
+ struct bch_dev *ca;
+ unsigned dev_iter;
+ size_t i, bu;
+
+ for_each_rw_member(ca, c, dev_iter) {
+ unsigned done = 0;
+
+ fifo_for_each_entry(bu, &ca->free_inc, i) {
+ if (done == ca->nr_invalidated)
+ break;
+
+ blkdev_issue_discard(ca->disk_sb.bdev,
+ bucket_to_sector(ca, bu),
+ ca->mi.bucket_size, GFP_NOIO);
+ done++;
+ }
+ }
+}
+
+static int __bch2_fs_allocator_start(struct bch_fs *c)
+{
+ struct bch_dev *ca;
+ size_t bu, i;
+ unsigned dev_iter;
+ u64 journal_seq = 0;
+ bool invalidating_data = false;
+ int ret = 0;
+
+ if (test_bit(BCH_FS_GC_FAILURE, &c->flags))
+ return -1;
+
+ /* 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);
+ ca->nr_invalidated++;
+
+ 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 - find_reclaimable_buckets() assumes it's empty */
+ 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) {
+ BUG_ON(!fifo_empty(&ca->free_inc));
+ ca->free_inc.front = ca->free_inc.back = 0;
+
+ find_reclaimable_buckets(c, ca);
+ sort_free_inc(c, ca);
+
+ invalidating_data |= ca->allocator_invalidating_data;
+
+ fifo_for_each_entry(bu, &ca->free_inc, i)
+ if (!fifo_push(&ca->free[RESERVE_BTREE], bu))
+ break;
+ }
+
+ 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) {
+ 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?
+ */
+
+ for_each_rw_member(ca, c, dev_iter) {
+ ret = bch2_invalidate_free_inc(c, ca, &journal_seq,
+ ca->free[RESERVE_BTREE].size,
+ false);
+ if (ret) {
+ percpu_ref_put(&ca->io_ref);
+ 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);
+ }
+
+ for_each_rw_member(ca, c, dev_iter)
+ while (ca->nr_invalidated) {
+ BUG_ON(!fifo_pop(&ca->free_inc, bu));
+ ca->nr_invalidated--;
+ }
+
+ set_bit(BCH_FS_ALLOCATOR_STARTED, &c->flags);
+
+ /* now flush dirty btree nodes: */
+ if (invalidating_data) {
+ struct bucket_table *tbl;
+ struct rhash_head *pos;
+ struct btree *b;
+ bool flush_updates;
+ size_t 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();
+
+ /*
+ * 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;
+ }
+ }
+
+ 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);
+}
