bcachefs: Make copygc thread global

Per device copygc threads don't move data to different devices and they
make fragmentation works - they don't make much sense anymore.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

1 files changed, 117 insertions, 96 deletions

diff --git a/fs/bcachefs/movinggc.c b/fs/bcachefs/movinggc.c
index 135bbc102b53..c33b58dc5c50 100644
--- a/fs/bcachefs/movinggc.c
+++ b/fs/bcachefs/movinggc.c
@@ -43,13 +43,6 @@
 #define COPYGC_BUCKETS_PER_ITER(ca)					\
 	((ca)->free[RESERVE_MOVINGGC].size / 2)
 
-/*
- * 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))
-
 static inline int sectors_used_cmp(copygc_heap *heap,
 				   struct copygc_heap_entry l,
 				   struct copygc_heap_entry r)
@@ -62,18 +55,22 @@ static int bucket_offset_cmp(const void *_l, const void *_r, size_t size)
 	const struct copygc_heap_entry *l = _l;
 	const struct copygc_heap_entry *r = _r;
 
-	return cmp_int(l->offset, r->offset);
+	return  cmp_int(l->dev,    r->dev) ?:
+		cmp_int(l->offset, r->offset);
 }
 
-static bool __copygc_pred(struct bch_dev *ca,
-			  struct bkey_s_c k)
+static int __copygc_pred(struct bch_fs *c, struct bkey_s_c k)
 {
-	copygc_heap *h = &ca->copygc_heap;
-	const struct bch_extent_ptr *ptr =
-		bch2_bkey_has_device(k, ca->dev_idx);
-
-	if (ptr) {
-		struct copygc_heap_entry search = { .offset = ptr->offset };
+	copygc_heap *h = &c->copygc_heap;
+	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
+	const struct bch_extent_ptr *ptr;
+
+	bkey_for_each_ptr(ptrs, ptr) {
+		struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
+		struct copygc_heap_entry search = {
+			.dev = ptr->dev,
+			.offset = ptr->offset
+		};
 
 		ssize_t i = eytzinger0_find_le(h->data, h->used,
 					       sizeof(h->data[0]),
@@ -89,12 +86,13 @@ static bool __copygc_pred(struct bch_dev *ca,
 
 		BUG_ON(i != j);
 #endif
-		return (i >= 0 &&
-			ptr->offset < h->data[i].offset + ca->mi.bucket_size &&
-			ptr->gen == h->data[i].gen);
+		if (i >= 0 &&
+		    ptr->offset < h->data[i].offset + ca->mi.bucket_size &&
+		    ptr->gen == h->data[i].gen)
+			return ptr->dev;
 	}
 
-	return false;
+	return -1;
 }
 
 static enum data_cmd copygc_pred(struct bch_fs *c, void *arg,
@@ -102,14 +100,14 @@ static enum data_cmd copygc_pred(struct bch_fs *c, void *arg,
 				 struct bch_io_opts *io_opts,
 				 struct data_opts *data_opts)
 {
-	struct bch_dev *ca = arg;
-
-	if (!__copygc_pred(ca, k))
+	int dev_idx = __copygc_pred(c, k);
+	if (dev_idx < 0)
 		return DATA_SKIP;
 
-	data_opts->target		= dev_to_target(ca->dev_idx);
+	/* XXX: use io_opts for this inode */
+	data_opts->target		= dev_to_target(dev_idx);
 	data_opts->btree_insert_flags	= BTREE_INSERT_USE_RESERVE;
-	data_opts->rewrite_dev		= ca->dev_idx;
+	data_opts->rewrite_dev		= dev_idx;
 	return DATA_REWRITE;
 }
 
@@ -125,20 +123,21 @@ static bool have_copygc_reserve(struct bch_dev *ca)
 	return ret;
 }
 
-static void bch2_copygc(struct bch_fs *c, struct bch_dev *ca)
+static void bch2_copygc(struct bch_fs *c)
 {
-	copygc_heap *h = &ca->copygc_heap;
+	copygc_heap *h = &c->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 sectors_reserved = 0;
 	u64 buckets_to_move, buckets_not_moved = 0;
-	size_t b;
+	struct bch_dev *ca;
+	unsigned dev_idx;
+	size_t b, heap_size = 0;
 	int ret;
 
 	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,
@@ -147,38 +146,51 @@ static void bch2_copygc(struct bch_fs *c, struct bch_dev *ca)
 	 */
 	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)
-			continue;
+	for_each_rw_member(ca, c, dev_idx)
+		heap_size += ca->mi.nbuckets >> 7;
 
-		e = (struct copygc_heap_entry) {
-			.gen		= m.gen,
-			.sectors	= bucket_sectors_used(m),
-			.offset		= bucket_to_sector(ca, b),
-		};
-		heap_add_or_replace(h, e, -sectors_used_cmp, NULL);
+	if (h->size < heap_size) {
+		free_heap(&c->copygc_heap);
+		if (!init_heap(&c->copygc_heap, heap_size, GFP_KERNEL)) {
+			bch_err(c, "error allocating copygc heap");
+			return;
+		}
+	}
+
+	for_each_rw_member(ca, c, dev_idx) {
+		closure_wait_event(&c->freelist_wait, have_copygc_reserve(ca));
+
+		spin_lock(&ca->fs->freelist_lock);
+		sectors_reserved += fifo_used(&ca->free[RESERVE_MOVINGGC]) * ca->mi.bucket_size;
+		spin_unlock(&ca->fs->freelist_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)
+				continue;
+
+			e = (struct copygc_heap_entry) {
+				.gen		= m.gen,
+				.sectors	= bucket_sectors_used(m),
+				.offset		= bucket_to_sector(ca, b),
+			};
+			heap_add_or_replace(h, e, -sectors_used_cmp, NULL);
+		}
+		up_read(&ca->bucket_lock);
 	}
-	up_read(&ca->bucket_lock);
-	up_read(&c->gc_lock);
 
 	for (i = h->data; i < h->data + h->used; i++)
 		sectors_to_move += i->sectors;
 
-	while (sectors_to_move > COPYGC_SECTORS_PER_ITER(ca)) {
+	while (sectors_to_move > sectors_reserved) {
 		BUG_ON(!heap_pop(h, e, -sectors_used_cmp, NULL));
 		sectors_to_move -= e.sectors;
 	}
@@ -192,24 +204,26 @@ static void bch2_copygc(struct bch_fs *c, struct bch_dev *ca)
 			sizeof(h->data[0]),
 			bucket_offset_cmp, NULL);
 
-	ret = bch2_move_data(c, &ca->copygc_pd.rate,
-			     writepoint_ptr(&ca->copygc_write_point),
+	ret = bch2_move_data(c, &c->copygc_pd.rate,
+			     writepoint_ptr(&c->copygc_write_point),
 			     POS_MIN, POS_MAX,
-			     copygc_pred, ca,
+			     copygc_pred, NULL,
 			     &move_stats);
 
-	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);
-
-		if (i->gen == m.gen && bucket_sectors_used(m)) {
-			sectors_not_moved += bucket_sectors_used(m);
-			buckets_not_moved++;
+	for_each_rw_member(ca, c, dev_idx) {
+		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);
+
+			if (i->gen == m.gen && bucket_sectors_used(m)) {
+				sectors_not_moved += bucket_sectors_used(m);
+				buckets_not_moved++;
+			}
 		}
+		up_read(&ca->bucket_lock);
 	}
-	up_read(&ca->bucket_lock);
 
 	if (sectors_not_moved && !ret)
 		bch_warn_ratelimited(c,
@@ -220,7 +234,7 @@ static void bch2_copygc(struct bch_fs *c, struct bch_dev *ca)
 			 atomic64_read(&move_stats.keys_raced),
 			 atomic64_read(&move_stats.sectors_raced));
 
-	trace_copygc(ca,
+	trace_copygc(c,
 		     atomic64_read(&move_stats.sectors_moved), sectors_not_moved,
 		     buckets_to_move, buckets_not_moved);
 }
@@ -239,20 +253,27 @@ static void bch2_copygc(struct bch_fs *c, struct bch_dev *ca)
  * 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_dev *ca)
+unsigned long bch2_copygc_wait_amount(struct bch_fs *c)
 {
-	struct bch_fs *c = ca->fs;
-	struct bch_dev_usage usage = bch2_dev_usage_read(c, ca);
-	u64 fragmented_allowed = ca->copygc_threshold +
-		((__dev_buckets_available(ca, usage) * ca->mi.bucket_size) >> 1);
+	struct bch_dev *ca;
+	unsigned dev_idx;
+	u64 fragmented_allowed = c->copygc_threshold;
+	u64 fragmented = 0;
+
+	for_each_rw_member(ca, c, dev_idx) {
+		struct bch_dev_usage usage = bch2_dev_usage_read(c, ca);
+
+		fragmented_allowed += ((__dev_buckets_available(ca, usage) *
+					ca->mi.bucket_size) >> 1);
+		fragmented += usage.sectors_fragmented;
+	}
 
-	return max_t(s64, 0, fragmented_allowed - usage.sectors_fragmented);
+	return max_t(s64, 0, fragmented_allowed - fragmented);
 }
 
 static int bch2_copygc_thread(void *arg)
 {
-	struct bch_dev *ca = arg;
-	struct bch_fs *c = ca->fs;
+	struct bch_fs *c = arg;
 	struct io_clock *clock = &c->io_clock[WRITE];
 	unsigned long last, wait;
 
@@ -263,7 +284,7 @@ static int bch2_copygc_thread(void *arg)
 			break;
 
 		last = atomic_long_read(&clock->now);
-		wait = bch2_copygc_wait_amount(ca);
+		wait = bch2_copygc_wait_amount(c);
 
 		if (wait > clock->max_slop) {
 			bch2_kthread_io_clock_wait(clock, last + wait,
@@ -271,29 +292,29 @@ static int bch2_copygc_thread(void *arg)
 			continue;
 		}
 
-		bch2_copygc(c, ca);
+		bch2_copygc(c);
 	}
 
 	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);
+	c->copygc_pd.rate.rate = UINT_MAX;
+	bch2_ratelimit_reset(&c->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;
 
-	if (ca->copygc_thread)
+	if (c->copygc_thread)
 		return 0;
 
 	if (c->opts.nochanges)
@@ -302,21 +323,21 @@ 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[%s]", ca->name);
+	t = kthread_create(bch2_copygc_thread, c,
+			   "bch_copygc[%s]", c->name);
 	if (IS_ERR(t))
 		return PTR_ERR(t);
 
 	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;
+	bch2_pd_controller_init(&c->copygc_pd);
+	c->copygc_pd.d_term = 0;
 }