X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libbcachefs%2Fmovinggc.c;h=5242f20bb680fc2c0d9fc8ebd54188db87dfa8ab;hb=87179c7a6e2a210ea57951d444a3055e883d08fa;hp=8804dbb32a69b64192770026d285d258e142a577;hpb=5ec39af8eaba49aee7bafa44c661da39e2f40dc3;p=bcachefs-tools-debian

diff --git a/libbcachefs/movinggc.c b/libbcachefs/movinggc.c
index 8804dbb..5242f20 100644
--- a/libbcachefs/movinggc.c
+++ b/libbcachefs/movinggc.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Moving/copying garbage collector
  *
@@ -5,293 +6,416 @@
  */
 
 #include "bcachefs.h"
+#include "alloc_background.h"
+#include "alloc_foreground.h"
 #include "btree_iter.h"
+#include "btree_update.h"
+#include "btree_write_buffer.h"
 #include "buckets.h"
 #include "clock.h"
+#include "disk_groups.h"
+#include "errcode.h"
+#include "error.h"
 #include "extents.h"
+#include "eytzinger.h"
 #include "io.h"
 #include "keylist.h"
+#include "lru.h"
 #include "move.h"
 #include "movinggc.h"
+#include "super-io.h"
+#include "trace.h"
 
-#include <trace/events/bcachefs.h>
+#include <linux/bsearch.h>
 #include <linux/freezer.h>
 #include <linux/kthread.h>
+#include <linux/math64.h>
+#include <linux/sched/task.h>
+#include <linux/sort.h>
 #include <linux/wait.h>
 
-/* Moving GC - IO loop */
-
-static const struct bch_extent_ptr *moving_pred(struct bch_dev *ca,
-						struct bkey_s_c k)
+struct buckets_in_flight {
+	struct rhashtable		table;
+	struct move_bucket_in_flight	*first;
+	struct move_bucket_in_flight	*last;
+	size_t				nr;
+	size_t				sectors;
+};
+
+static const struct rhashtable_params bch_move_bucket_params = {
+	.head_offset	= offsetof(struct move_bucket_in_flight, hash),
+	.key_offset	= offsetof(struct move_bucket_in_flight, bucket.k),
+	.key_len	= sizeof(struct move_bucket_key),
+};
+
+static struct move_bucket_in_flight *
+move_bucket_in_flight_add(struct buckets_in_flight *list, struct move_bucket b)
 {
-	const struct bch_extent_ptr *ptr;
+	struct move_bucket_in_flight *new = kzalloc(sizeof(*new), GFP_KERNEL);
+	int ret;
+
+	if (!new)
+		return ERR_PTR(-ENOMEM);
+
+	new->bucket = b;
+
+	ret = rhashtable_lookup_insert_fast(&list->table, &new->hash,
+					    bch_move_bucket_params);
+	if (ret) {
+		kfree(new);
+		return ERR_PTR(ret);
+	}
 
-	if (bkey_extent_is_data(k.k) &&
-	    (ptr = bch2_extent_has_device(bkey_s_c_to_extent(k),
-					 ca->dev_idx)) &&
-	    PTR_BUCKET(ca, ptr)->mark.copygc)
-		return ptr;
+	if (!list->first)
+		list->first = new;
+	else
+		list->last->next = new;
 
-	return NULL;
+	list->last = new;
+	list->nr++;
+	list->sectors += b.sectors;
+	return new;
 }
 
-static int issue_moving_gc_move(struct bch_dev *ca,
-				struct moving_context *ctxt,
-				struct bkey_s_c k)
+static int bch2_bucket_is_movable(struct btree_trans *trans,
+				  struct move_bucket *b, u64 time)
 {
-	struct bch_fs *c = ca->fs;
-	const struct bch_extent_ptr *ptr;
+	struct btree_iter iter;
+	struct bkey_s_c k;
+	struct bch_alloc_v4 _a;
+	const struct bch_alloc_v4 *a;
 	int ret;
 
-	ptr = moving_pred(ca, k);
-	if (!ptr) /* We raced - bucket's been reused */
+	if (bch2_bucket_is_open(trans->c,
+				b->k.bucket.inode,
+				b->k.bucket.offset))
 		return 0;
 
-	ret = bch2_data_move(c, ctxt, &ca->copygc_write_point, k, ptr);
-	if (!ret)
-		trace_gc_copy(k.k);
-	else
-		trace_moving_gc_alloc_fail(c, k.k->size);
+	k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_alloc,
+			       b->k.bucket, BTREE_ITER_CACHED);
+	ret = bkey_err(k);
+	if (ret)
+		return ret;
+
+	a = bch2_alloc_to_v4(k, &_a);
+	b->k.gen	= a->gen;
+	b->sectors	= a->dirty_sectors;
+
+	ret = data_type_movable(a->data_type) &&
+		a->fragmentation_lru &&
+		a->fragmentation_lru <= time;
+
+	bch2_trans_iter_exit(trans, &iter);
 	return ret;
 }
 
-static void read_moving(struct bch_dev *ca, size_t buckets_to_move,
-			u64 sectors_to_move)
+static void move_buckets_wait(struct btree_trans *trans,
+			      struct moving_context *ctxt,
+			      struct buckets_in_flight *list,
+			      bool flush)
 {
-	struct bch_fs *c = ca->fs;
-	struct bucket *g;
-	struct moving_context ctxt;
-	struct btree_iter iter;
-	struct bkey_s_c k;
-	u64 sectors_not_moved = 0;
-	size_t buckets_not_moved = 0;
-
-	bch2_ratelimit_reset(&ca->moving_gc_pd.rate);
-	bch2_move_ctxt_init(&ctxt, &ca->moving_gc_pd.rate,
-				SECTORS_IN_FLIGHT_PER_DEVICE);
-	bch2_btree_iter_init(&iter, c, BTREE_ID_EXTENTS, POS_MIN);
-
-	while (1) {
-		if (kthread_should_stop())
-			goto out;
-		if (bch2_move_ctxt_wait(&ctxt))
-			goto out;
-		k = bch2_btree_iter_peek(&iter);
-		if (!k.k)
-			break;
-		if (btree_iter_err(k))
-			goto out;
-
-		if (!moving_pred(ca, k))
-			goto next;
+	struct move_bucket_in_flight *i;
+	int ret;
 
-		if (issue_moving_gc_move(ca, &ctxt, k)) {
-			bch2_btree_iter_unlock(&iter);
+	while ((i = list->first)) {
+		if (flush)
+			move_ctxt_wait_event(ctxt, trans, !atomic_read(&i->count));
 
-			/* memory allocation failure, wait for some IO to finish */
-			bch2_move_ctxt_wait_for_io(&ctxt);
-			continue;
-		}
-next:
-		bch2_btree_iter_advance_pos(&iter);
-		//bch2_btree_iter_cond_resched(&iter);
+		if (atomic_read(&i->count))
+			break;
 
-		/* unlock before calling moving_context_wait() */
-		bch2_btree_iter_unlock(&iter);
-		cond_resched();
-	}
+		list->first = i->next;
+		if (!list->first)
+			list->last = NULL;
 
-	bch2_btree_iter_unlock(&iter);
-	bch2_move_ctxt_exit(&ctxt);
-	trace_moving_gc_end(ca, ctxt.sectors_moved, ctxt.keys_moved,
-				   buckets_to_move);
+		list->nr--;
+		list->sectors -= i->bucket.sectors;
 
-	/* don't check this if we bailed out early: */
-	for_each_bucket(g, ca)
-		if (g->mark.copygc && bucket_sectors_used(g)) {
-			sectors_not_moved += bucket_sectors_used(g);
-			buckets_not_moved++;
-		}
+		ret = rhashtable_remove_fast(&list->table, &i->hash,
+					     bch_move_bucket_params);
+		BUG_ON(ret);
+		kfree(i);
+	}
 
-	if (sectors_not_moved)
-		bch_warn(c, "copygc finished but %llu/%llu sectors, %zu/%zu buckets not moved",
-			 sectors_not_moved, sectors_to_move,
-			 buckets_not_moved, buckets_to_move);
-	return;
-out:
-	bch2_btree_iter_unlock(&iter);
-	bch2_move_ctxt_exit(&ctxt);
-	trace_moving_gc_end(ca, ctxt.sectors_moved, ctxt.keys_moved,
-				   buckets_to_move);
+	bch2_trans_unlock(trans);
 }
 
-static bool have_copygc_reserve(struct bch_dev *ca)
+static bool bucket_in_flight(struct buckets_in_flight *list,
+			     struct move_bucket_key k)
 {
-	bool ret;
-
-	spin_lock(&ca->freelist_lock);
-	ret = fifo_used(&ca->free[RESERVE_MOVINGGC]) >=
-		COPYGC_BUCKETS_PER_ITER(ca);
-	spin_unlock(&ca->freelist_lock);
-
-	return ret;
+	return rhashtable_lookup_fast(&list->table, &k, bch_move_bucket_params);
 }
 
-static void bch2_moving_gc(struct bch_dev *ca)
-{
-	struct bch_fs *c = ca->fs;
-	struct bucket *g;
-	struct bucket_mark new;
-	u64 sectors_to_move;
-	size_t buckets_to_move, buckets_unused = 0;
-	struct bucket_heap_entry e;
-	unsigned sectors_used, i;
-	int reserve_sectors;
-
-	if (!have_copygc_reserve(ca)) {
-		struct closure cl;
-
-		closure_init_stack(&cl);
-		while (1) {
-			closure_wait(&c->freelist_wait, &cl);
-			if (have_copygc_reserve(ca))
-				break;
-			closure_sync(&cl);
-		}
-		closure_wake_up(&c->freelist_wait);
-	}
+typedef DARRAY(struct move_bucket) move_buckets;
 
-	reserve_sectors = COPYGC_SECTORS_PER_ITER(ca);
+static int bch2_copygc_get_buckets(struct btree_trans *trans,
+			struct moving_context *ctxt,
+			struct buckets_in_flight *buckets_in_flight,
+			move_buckets *buckets)
+{
+	struct bch_fs *c = trans->c;
+	struct btree_iter iter;
+	struct bkey_s_c k;
+	size_t nr_to_get = max(16UL, buckets_in_flight->nr / 4);
+	size_t saw = 0, in_flight = 0, not_movable = 0, sectors = 0;
+	int ret;
 
-	trace_moving_gc_start(ca);
+	move_buckets_wait(trans, ctxt, buckets_in_flight, false);
+
+	ret = bch2_btree_write_buffer_flush(trans);
+	if (bch2_fs_fatal_err_on(ret, c, "%s: error %s from bch2_btree_write_buffer_flush()",
+				 __func__, bch2_err_str(ret)))
+		return ret;
+
+	ret = for_each_btree_key2_upto(trans, iter, BTREE_ID_lru,
+				  lru_pos(BCH_LRU_FRAGMENTATION_START, 0, 0),
+				  lru_pos(BCH_LRU_FRAGMENTATION_START, U64_MAX, LRU_TIME_MAX),
+				  0, k, ({
+		struct move_bucket b = { .k.bucket = u64_to_bucket(k.k->p.offset) };
+		int ret = 0;
+
+		saw++;
+
+		if (!bch2_bucket_is_movable(trans, &b, lru_pos_time(k.k->p)))
+			not_movable++;
+		else if (bucket_in_flight(buckets_in_flight, b.k))
+			in_flight++;
+		else {
+			ret = darray_push(buckets, b) ?: buckets->nr >= nr_to_get;
+			if (ret >= 0)
+				sectors += b.sectors;
+		}
+		ret;
+	}));
 
-	/*
-	 * Find buckets with lowest sector counts, skipping completely
-	 * empty buckets, by building a maxheap sorted by sector count,
-	 * and repeatedly replacing the maximum element until all
-	 * buckets have been visited.
-	 */
+	pr_debug("have: %zu (%zu) saw %zu in flight %zu not movable %zu got %zu (%zu)/%zu buckets ret %i",
+		 buckets_in_flight->nr, buckets_in_flight->sectors,
+		 saw, in_flight, not_movable, buckets->nr, sectors, nr_to_get, ret);
 
-	/*
-	 * We need bucket marks to be up to date, so gc can't be recalculating
-	 * them, and we don't want the allocator invalidating a bucket after
-	 * we've decided to evacuate it but before we set copygc:
-	 */
-	down_read(&c->gc_lock);
-	mutex_lock(&ca->heap_lock);
-	mutex_lock(&ca->fs->bucket_lock);
+	return ret < 0 ? ret : 0;
+}
 
-	ca->heap.used = 0;
-	for_each_bucket(g, ca) {
-		bucket_cmpxchg(g, new, new.copygc = 0);
+noinline
+static int bch2_copygc(struct btree_trans *trans,
+		       struct moving_context *ctxt,
+		       struct buckets_in_flight *buckets_in_flight)
+{
+	struct bch_fs *c = trans->c;
+	struct data_update_opts data_opts = {
+		.btree_insert_flags = BCH_WATERMARK_copygc,
+	};
+	move_buckets buckets = { 0 };
+	struct move_bucket_in_flight *f;
+	struct move_bucket *i;
+	u64 moved = atomic64_read(&ctxt->stats->sectors_moved);
+	int ret = 0;
+
+	ret = bch2_copygc_get_buckets(trans, ctxt, buckets_in_flight, &buckets);
+	if (ret)
+		goto err;
+
+	darray_for_each(buckets, i) {
+		if (unlikely(freezing(current)))
+			break;
 
-		if (bucket_unused(g)) {
-			buckets_unused++;
+		f = move_bucket_in_flight_add(buckets_in_flight, *i);
+		ret = PTR_ERR_OR_ZERO(f);
+		if (ret == -EEXIST) /* rare race: copygc_get_buckets returned same bucket more than once */
 			continue;
+		if (ret == -ENOMEM) { /* flush IO, continue later */
+			ret = 0;
+			break;
 		}
 
-		if (g->mark.owned_by_allocator ||
-		    g->mark.data_type != BUCKET_DATA)
-			continue;
+		ret = __bch2_evacuate_bucket(trans, ctxt, f, f->bucket.k.bucket,
+					     f->bucket.k.gen, data_opts);
+		if (ret)
+			goto err;
+	}
+err:
+	darray_exit(&buckets);
 
-		sectors_used = bucket_sectors_used(g);
+	/* no entries in LRU btree found, or got to end: */
+	if (bch2_err_matches(ret, ENOENT))
+		ret = 0;
 
-		if (sectors_used >= ca->mi.bucket_size)
-			continue;
+	if (ret < 0 && !bch2_err_matches(ret, EROFS))
+		bch_err(c, "error from bch2_move_data() in copygc: %s", bch2_err_str(ret));
 
-		bucket_heap_push(ca, g, sectors_used);
-	}
+	moved = atomic64_read(&ctxt->stats->sectors_moved) - moved;
+	trace_and_count(c, copygc, c, moved, 0, 0, 0);
+	return ret;
+}
+
+/*
+ * Copygc runs when the amount of fragmented data is above some arbitrary
+ * threshold:
+ *
+ * The threshold at the limit - when the device is full - is the amount of space
+ * we reserved in bch2_recalc_capacity; we can't have more than that amount of
+ * disk space stranded due to fragmentation and store everything we have
+ * promised to store.
+ *
+ * But we don't want to be running copygc unnecessarily when the device still
+ * has plenty of free space - rather, we want copygc to smoothly run every so
+ * often and continually reduce the amount of fragmented space as the device
+ * fills up. So, we increase the threshold by half the current free space.
+ */
+unsigned long bch2_copygc_wait_amount(struct bch_fs *c)
+{
+	struct bch_dev *ca;
+	unsigned dev_idx;
+	s64 wait = S64_MAX, fragmented_allowed, fragmented;
+	unsigned i;
 
-	sectors_to_move = 0;
-	for (i = 0; i < ca->heap.used; i++)
-		sectors_to_move += ca->heap.data[i].val;
+	for_each_rw_member(ca, c, dev_idx) {
+		struct bch_dev_usage usage = bch2_dev_usage_read(ca);
 
-	while (sectors_to_move > COPYGC_SECTORS_PER_ITER(ca)) {
-		BUG_ON(!heap_pop(&ca->heap, e, bucket_min_cmp));
-		sectors_to_move -= e.val;
-	}
+		fragmented_allowed = ((__dev_buckets_available(ca, usage, BCH_WATERMARK_stripe) *
+				       ca->mi.bucket_size) >> 1);
+		fragmented = 0;
 
-	for (i = 0; i < ca->heap.used; i++)
-		bucket_cmpxchg(ca->heap.data[i].g, new, new.copygc = 1);
+		for (i = 0; i < BCH_DATA_NR; i++)
+			if (data_type_movable(i))
+				fragmented += usage.d[i].fragmented;
 
-	buckets_to_move = ca->heap.used;
+		wait = min(wait, max(0LL, fragmented_allowed - fragmented));
+	}
 
-	mutex_unlock(&ca->fs->bucket_lock);
-	mutex_unlock(&ca->heap_lock);
-	up_read(&c->gc_lock);
+	return wait;
+}
 
-	read_moving(ca, buckets_to_move, sectors_to_move);
+void bch2_copygc_wait_to_text(struct printbuf *out, struct bch_fs *c)
+{
+	prt_printf(out, "Currently waiting for:     ");
+	prt_human_readable_u64(out, max(0LL, c->copygc_wait -
+					atomic64_read(&c->io_clock[WRITE].now)) << 9);
+	prt_newline(out);
+
+	prt_printf(out, "Currently waiting since:   ");
+	prt_human_readable_u64(out, max(0LL,
+					atomic64_read(&c->io_clock[WRITE].now) -
+					c->copygc_wait_at) << 9);
+	prt_newline(out);
+
+	prt_printf(out, "Currently calculated wait: ");
+	prt_human_readable_u64(out, bch2_copygc_wait_amount(c));
+	prt_newline(out);
 }
 
-static int bch2_moving_gc_thread(void *arg)
+static int bch2_copygc_thread(void *arg)
 {
-	struct bch_dev *ca = arg;
-	struct bch_fs *c = ca->fs;
+	struct bch_fs *c = arg;
+	struct btree_trans trans;
+	struct moving_context ctxt;
+	struct bch_move_stats move_stats;
 	struct io_clock *clock = &c->io_clock[WRITE];
-	unsigned long last;
-	u64 available, want, next;
+	struct buckets_in_flight move_buckets;
+	u64 last, wait;
+	int ret = 0;
+
+	memset(&move_buckets, 0, sizeof(move_buckets));
+
+	ret = rhashtable_init(&move_buckets.table, &bch_move_bucket_params);
+	if (ret) {
+		bch_err(c, "error allocating copygc buckets in flight: %s",
+			bch2_err_str(ret));
+		return ret;
+	}
 
 	set_freezable();
+	bch2_trans_init(&trans, c, 0, 0);
 
-	while (!kthread_should_stop()) {
-		if (kthread_wait_freezable(c->copy_gc_enabled))
-			break;
+	bch2_move_stats_init(&move_stats, "copygc");
+	bch2_moving_ctxt_init(&ctxt, c, NULL, &move_stats,
+			      writepoint_ptr(&c->copygc_write_point),
+			      false);
+
+	while (!ret && !kthread_should_stop()) {
+		bch2_trans_unlock(&trans);
+		cond_resched();
+
+		if (!c->copy_gc_enabled) {
+			move_buckets_wait(&trans, &ctxt, &move_buckets, true);
+			kthread_wait_freezable(c->copy_gc_enabled);
+		}
+
+		if (unlikely(freezing(current))) {
+			move_buckets_wait(&trans, &ctxt, &move_buckets, true);
+			__refrigerator(false);
+			continue;
+		}
+
+		last = atomic64_read(&clock->now);
+		wait = bch2_copygc_wait_amount(c);
 
-		last = atomic_long_read(&clock->now);
-		/*
-		 * don't start copygc until less than half the gc reserve is
-		 * available:
-		 */
-		available = dev_buckets_available(ca);
-		want = div64_u64((ca->mi.nbuckets - ca->mi.first_bucket) *
-				 c->opts.gc_reserve_percent, 200);
-		if (available > want) {
-			next = last + (available - want) *
-				ca->mi.bucket_size;
-			bch2_kthread_io_clock_wait(clock, next);
+		if (wait > clock->max_slop) {
+			c->copygc_wait_at = last;
+			c->copygc_wait = last + wait;
+			move_buckets_wait(&trans, &ctxt, &move_buckets, true);
+			trace_and_count(c, copygc_wait, c, wait, last + wait);
+			bch2_kthread_io_clock_wait(clock, last + wait,
+					MAX_SCHEDULE_TIMEOUT);
 			continue;
 		}
 
-		bch2_moving_gc(ca);
+		c->copygc_wait = 0;
+
+		c->copygc_running = true;
+		ret = bch2_copygc(&trans, &ctxt, &move_buckets);
+		c->copygc_running = false;
+
+		wake_up(&c->copygc_running_wq);
 	}
 
+	move_buckets_wait(&trans, &ctxt, &move_buckets, true);
+	rhashtable_destroy(&move_buckets.table);
+	bch2_trans_exit(&trans);
+	bch2_moving_ctxt_exit(&ctxt);
+
 	return 0;
 }
 
-void bch2_moving_gc_stop(struct bch_dev *ca)
+void bch2_copygc_stop(struct bch_fs *c)
 {
-	ca->moving_gc_pd.rate.rate = UINT_MAX;
-	bch2_ratelimit_reset(&ca->moving_gc_pd.rate);
-
-	if (ca->moving_gc_read)
-		kthread_stop(ca->moving_gc_read);
-	ca->moving_gc_read = NULL;
+	if (c->copygc_thread) {
+		kthread_stop(c->copygc_thread);
+		put_task_struct(c->copygc_thread);
+	}
+	c->copygc_thread = NULL;
 }
 
-int bch2_moving_gc_start(struct bch_dev *ca)
+int bch2_copygc_start(struct bch_fs *c)
 {
 	struct task_struct *t;
+	int ret;
 
-	BUG_ON(ca->moving_gc_read);
+	if (c->copygc_thread)
+		return 0;
 
-	if (ca->fs->opts.nochanges)
+	if (c->opts.nochanges)
 		return 0;
 
-	if (bch2_fs_init_fault("moving_gc_start"))
+	if (bch2_fs_init_fault("copygc_start"))
 		return -ENOMEM;
 
-	t = kthread_create(bch2_moving_gc_thread, ca, "bch_copygc_read");
-	if (IS_ERR(t))
-		return PTR_ERR(t);
+	t = kthread_create(bch2_copygc_thread, c, "bch-copygc/%s", c->name);
+	ret = PTR_ERR_OR_ZERO(t);
+	if (ret) {
+		bch_err(c, "error creating copygc thread: %s", bch2_err_str(ret));
+		return ret;
+	}
+
+	get_task_struct(t);
 
-	ca->moving_gc_read = t;
-	wake_up_process(ca->moving_gc_read);
+	c->copygc_thread = t;
+	wake_up_process(c->copygc_thread);
 
 	return 0;
 }
 
-void bch2_dev_moving_gc_init(struct bch_dev *ca)
+void bch2_fs_copygc_init(struct bch_fs *c)
 {
-	bch2_pd_controller_init(&ca->moving_gc_pd);
-	ca->moving_gc_pd.d_term = 0;
+	init_waitqueue_head(&c->copygc_running_wq);
+	c->copygc_running = false;
 }