X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libbcachefs%2Fmovinggc.c;h=1a64643313cf188c4d197a3cfd11988250c28bd0;hb=da6a35689518599b381c285cd9505ab8d58f7c73;hp=0b1faee5094c87794e47b72b6ba79dde7753f25d;hpb=e7c4380a892297d2f65e1c317a1b6d4c67378299;p=bcachefs-tools-debian

diff --git a/libbcachefs/movinggc.c b/libbcachefs/movinggc.c
index 0b1faee..1a64643 100644
--- a/libbcachefs/movinggc.c
+++ b/libbcachefs/movinggc.c
@@ -6,17 +6,21 @@
  */
 
 #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"
@@ -29,237 +33,110 @@
 #include <linux/sort.h>
 #include <linux/wait.h>
 
-/*
- * We can't use the entire copygc reserve in one iteration of copygc: we may
- * need the buckets we're freeing up to go back into the copygc reserve to make
- * forward progress, but if the copygc reserve is full they'll be available for
- * any allocation - and it's possible that in a given iteration, we free up most
- * of the buckets we're going to free before we allocate most of the buckets
- * we're going to allocate.
- *
- * If we only use half of the reserve per iteration, then in steady state we'll
- * always have room in the reserve for the buckets we're going to need in the
- * next iteration:
- */
-#define COPYGC_BUCKETS_PER_ITER(ca)					\
-	((ca)->free[RESERVE_MOVINGGC].size / 2)
-
-static int bucket_offset_cmp(const void *_l, const void *_r, size_t size)
+static int bch2_bucket_is_movable(struct btree_trans *trans,
+				  struct bpos bucket, u64 time, u8 *gen)
 {
-	const struct copygc_heap_entry *l = _l;
-	const struct copygc_heap_entry *r = _r;
+	struct btree_iter iter;
+	struct bkey_s_c k;
+	struct bch_alloc_v4 _a;
+	const struct bch_alloc_v4 *a;
+	int ret;
 
-	return  cmp_int(l->dev,    r->dev) ?:
-		cmp_int(l->offset, r->offset);
-}
+	if (bch2_bucket_is_open(trans->c, bucket.inode, bucket.offset))
+		return 0;
 
-static enum data_cmd copygc_pred(struct bch_fs *c, void *arg,
-				 struct bkey_s_c k,
-				 struct bch_io_opts *io_opts,
-				 struct data_opts *data_opts)
-{
-	copygc_heap *h = &c->copygc_heap;
-	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
-	const union bch_extent_entry *entry;
-	struct extent_ptr_decoded p = { 0 };
-
-	bkey_for_each_ptr_decode(k.k, ptrs, p, entry) {
-		struct bch_dev *ca = bch_dev_bkey_exists(c, p.ptr.dev);
-		struct copygc_heap_entry search = {
-			.dev	= p.ptr.dev,
-			.offset	= p.ptr.offset,
-		};
-
-		ssize_t i = eytzinger0_find_le(h->data, h->used,
-					       sizeof(h->data[0]),
-					       bucket_offset_cmp, &search);
-#if 0
-		/* eytzinger search verify code: */
-		ssize_t j = -1, k;
-
-		for (k = 0; k < h->used; k++)
-			if (h->data[k].offset <= ptr->offset &&
-			    (j < 0 || h->data[k].offset > h->data[j].offset))
-				j = k;
-
-		BUG_ON(i != j);
-#endif
-		if (i >= 0 &&
-		    p.ptr.offset < h->data[i].offset + ca->mi.bucket_size &&
-		    p.ptr.gen == h->data[i].gen) {
-			data_opts->target		= io_opts->background_target;
-			data_opts->nr_replicas		= 1;
-			data_opts->btree_insert_flags	= BTREE_INSERT_USE_RESERVE;
-			data_opts->rewrite_dev		= p.ptr.dev;
-
-			if (p.has_ec)
-				data_opts->nr_replicas += p.ec.redundancy;
-
-			return DATA_REWRITE;
-		}
-	}
+	bch2_trans_iter_init(trans, &iter, BTREE_ID_alloc, bucket, 0);
+	k = bch2_btree_iter_peek_slot(&iter);
+	ret = bkey_err(k);
+	bch2_trans_iter_exit(trans, &iter);
 
-	return DATA_SKIP;
-}
+	if (ret)
+		return ret;
 
-static bool have_copygc_reserve(struct bch_dev *ca)
-{
-	bool ret;
+	a = bch2_alloc_to_v4(k, &_a);
+	*gen = a->gen;
+	ret = (a->data_type == BCH_DATA_btree ||
+	       a->data_type == BCH_DATA_user) &&
+		a->fragmentation_lru &&
+		a->fragmentation_lru <= time;
 
-	spin_lock(&ca->fs->freelist_lock);
-	ret = fifo_full(&ca->free[RESERVE_MOVINGGC]) ||
-		ca->allocator_state != ALLOCATOR_RUNNING;
-	spin_unlock(&ca->fs->freelist_lock);
+	if (ret) {
+		struct printbuf buf = PRINTBUF;
 
-	return ret;
-}
+		bch2_bkey_val_to_text(&buf, trans->c, k);
+		pr_debug("%s", buf.buf);
+		printbuf_exit(&buf);
+	}
 
-static inline int fragmentation_cmp(copygc_heap *heap,
-				   struct copygc_heap_entry l,
-				   struct copygc_heap_entry r)
-{
-	return cmp_int(l.fragmentation, r.fragmentation);
+	return ret;
 }
 
-static int bch2_copygc(struct bch_fs *c)
+static int bch2_copygc_next_bucket(struct btree_trans *trans,
+				   struct bpos *bucket, u8 *gen, struct bpos *pos)
 {
-	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;
-	struct bch_dev *ca;
-	unsigned dev_idx;
-	size_t b, heap_size = 0;
+	struct btree_iter iter;
+	struct bkey_s_c k;
 	int ret;
 
-	memset(&move_stats, 0, sizeof(move_stats));
-	/*
-	 * Find buckets with lowest sector counts, skipping completely
-	 * empty buckets, by building a maxheap sorted by sector count,
-	 * and repeatedly replacing the maximum element until all
-	 * buckets have been visited.
-	 */
-	h->used = 0;
-
-	for_each_rw_member(ca, c, dev_idx)
-		heap_size += ca->mi.nbuckets >> 7;
-
-	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 0;
-		}
-	}
+	ret = for_each_btree_key2_upto(trans, iter, BTREE_ID_lru,
+				  bpos_max(*pos, lru_pos(BCH_LRU_FRAGMENTATION_START, 0, 0)),
+				  lru_pos(BCH_LRU_FRAGMENTATION_START, U64_MAX, LRU_TIME_MAX),
+				  0, k, ({
+		*bucket = u64_to_bucket(k.k->p.offset);
 
-	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 *g = buckets->b + b;
-			struct bucket_mark m = READ_ONCE(g->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;
-
-			WARN_ON(m.stripe && !g->stripe_redundancy);
-
-			e = (struct copygc_heap_entry) {
-				.dev		= dev_idx,
-				.gen		= m.gen,
-				.replicas	= 1 + g->stripe_redundancy,
-				.fragmentation	= bucket_sectors_used(m) * (1U << 15)
-					/ ca->mi.bucket_size,
-				.sectors	= bucket_sectors_used(m),
-				.offset		= bucket_to_sector(ca, b),
-			};
-			heap_add_or_replace(h, e, -fragmentation_cmp, NULL);
-		}
-		up_read(&ca->bucket_lock);
-	}
-
-	if (!sectors_reserved) {
-		bch2_fs_fatal_error(c, "stuck, ran out of copygc reserve!");
-		return -1;
-	}
+		bch2_bucket_is_movable(trans, *bucket, lru_pos_time(k.k->p), gen);
+	}));
 
-	/*
-	 * Our btree node allocations also come out of RESERVE_MOVINGGC:
-	 */
-	sectors_to_move = (sectors_to_move * 3) / 4;
-
-	for (i = h->data; i < h->data + h->used; i++)
-		sectors_to_move += i->sectors * i->replicas;
+	*pos = iter.pos;
+	if (ret < 0)
+		return ret;
+	return ret ? 0 : -ENOENT;
+}
 
-	while (sectors_to_move > sectors_reserved) {
-		BUG_ON(!heap_pop(h, e, -fragmentation_cmp, NULL));
-		sectors_to_move -= e.sectors * e.replicas;
+static int bch2_copygc(struct bch_fs *c)
+{
+	struct bch_move_stats move_stats;
+	struct btree_trans trans;
+	struct moving_context ctxt;
+	struct data_update_opts data_opts = {
+		.btree_insert_flags = BTREE_INSERT_USE_RESERVE|JOURNAL_WATERMARK_copygc,
+	};
+	struct bpos bucket;
+	struct bpos pos;
+	u8 gen = 0;
+	unsigned nr_evacuated;
+	int ret = 0;
+
+	bch2_move_stats_init(&move_stats, "copygc");
+	bch2_moving_ctxt_init(&ctxt, c, NULL, &move_stats,
+			      writepoint_ptr(&c->copygc_write_point),
+			      false);
+	bch2_trans_init(&trans, c, 0, 0);
+
+	ret = bch2_btree_write_buffer_flush(&trans);
+	BUG_ON(ret);
+
+	for (nr_evacuated = 0, pos = POS_MIN;
+	     nr_evacuated < 32 && !ret;
+	     nr_evacuated++, pos = bpos_nosnap_successor(pos)) {
+		ret = bch2_copygc_next_bucket(&trans, &bucket, &gen, &pos) ?:
+			__bch2_evacuate_bucket(&trans, &ctxt, bucket, gen, data_opts);
+		if (bkey_eq(pos, POS_MAX))
+			break;
 	}
 
-	buckets_to_move = h->used;
-
-	if (!buckets_to_move)
-		return 0;
-
-	eytzinger0_sort(h->data, h->used,
-			sizeof(h->data[0]),
-			bucket_offset_cmp, NULL);
+	bch2_trans_exit(&trans);
+	bch2_moving_ctxt_exit(&ctxt);
 
-	ret = bch2_move_data(c, &c->copygc_pd.rate,
-			     writepoint_ptr(&c->copygc_write_point),
-			     POS_MIN, POS_MAX,
-			     copygc_pred, NULL,
-			     &move_stats);
+	/* no entries in LRU btree found, or got to end: */
+	if (ret == -ENOENT)
+		ret = 0;
 
-	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++) {
-			struct bucket_mark m;
-			size_t b;
-
-			if (i->dev != dev_idx)
-				continue;
-
-			b = sector_to_bucket(ca, i->offset);
-			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);
-	}
+	if (ret < 0 && !bch2_err_matches(ret, EROFS))
+		bch_err(c, "error from bch2_move_data() in copygc: %s", bch2_err_str(ret));
 
-	if (sectors_not_moved && !ret)
-		bch_warn_ratelimited(c,
-			"copygc finished but %llu/%llu sectors, %llu/%llu buckets not moved (move stats: moved %llu sectors, raced %llu keys, %llu sectors)",
-			 sectors_not_moved, sectors_to_move,
-			 buckets_not_moved, buckets_to_move,
-			 atomic64_read(&move_stats.sectors_moved),
-			 atomic64_read(&move_stats.keys_raced),
-			 atomic64_read(&move_stats.sectors_raced));
-
-	trace_copygc(c,
-		     atomic64_read(&move_stats.sectors_moved), sectors_not_moved,
-		     buckets_to_move, buckets_not_moved);
-	return 0;
+	trace_and_count(c, copygc, c, atomic64_read(&move_stats.sectors_moved), 0, 0, 0);
+	return ret;
 }
 
 /*
@@ -280,18 +157,19 @@ unsigned long bch2_copygc_wait_amount(struct bch_fs *c)
 {
 	struct bch_dev *ca;
 	unsigned dev_idx;
-	u64 fragmented_allowed = c->copygc_threshold;
-	u64 fragmented = 0;
+	s64 wait = S64_MAX, fragmented_allowed, fragmented;
 
 	for_each_rw_member(ca, c, dev_idx) {
 		struct bch_dev_usage usage = bch2_dev_usage_read(ca);
 
-		fragmented_allowed += ((__dev_buckets_available(ca, usage) *
-					ca->mi.bucket_size) >> 1);
-		fragmented += usage.d[BCH_DATA_user].fragmented;
+		fragmented_allowed = ((__dev_buckets_available(ca, usage, RESERVE_none) *
+				       ca->mi.bucket_size) >> 1);
+		fragmented = usage.d[BCH_DATA_user].fragmented;
+
+		wait = min(wait, max(0LL, fragmented_allowed - fragmented));
 	}
 
-	return max_t(s64, 0, fragmented_allowed - fragmented);
+	return wait;
 }
 
 static int bch2_copygc_thread(void *arg)
@@ -299,10 +177,13 @@ static int bch2_copygc_thread(void *arg)
 	struct bch_fs *c = arg;
 	struct io_clock *clock = &c->io_clock[WRITE];
 	u64 last, wait;
+	int ret = 0;
 
 	set_freezable();
 
-	while (!kthread_should_stop()) {
+	while (!ret && !kthread_should_stop()) {
+		cond_resched();
+
 		if (kthread_wait_freezable(c->copy_gc_enabled))
 			break;
 
@@ -310,13 +191,20 @@ static int bch2_copygc_thread(void *arg)
 		wait = bch2_copygc_wait_amount(c);
 
 		if (wait > clock->max_slop) {
+			trace_and_count(c, copygc_wait, c, wait, last + wait);
+			c->copygc_wait = last + wait;
 			bch2_kthread_io_clock_wait(clock, last + wait,
 					MAX_SCHEDULE_TIMEOUT);
 			continue;
 		}
 
-		if (bch2_copygc(c))
-			break;
+		c->copygc_wait = 0;
+
+		c->copygc_running = true;
+		ret = bch2_copygc(c);
+		c->copygc_running = false;
+
+		wake_up(&c->copygc_running_wq);
 	}
 
 	return 0;
@@ -324,9 +212,6 @@ static int bch2_copygc_thread(void *arg)
 
 void bch2_copygc_stop(struct bch_fs *c)
 {
-	c->copygc_pd.rate.rate = UINT_MAX;
-	bch2_ratelimit_reset(&c->copygc_pd.rate);
-
 	if (c->copygc_thread) {
 		kthread_stop(c->copygc_thread);
 		put_task_struct(c->copygc_thread);
@@ -337,6 +222,7 @@ void bch2_copygc_stop(struct bch_fs *c)
 int bch2_copygc_start(struct bch_fs *c)
 {
 	struct task_struct *t;
+	int ret;
 
 	if (c->copygc_thread)
 		return 0;
@@ -348,9 +234,10 @@ int bch2_copygc_start(struct bch_fs *c)
 		return -ENOMEM;
 
 	t = kthread_create(bch2_copygc_thread, c, "bch-copygc/%s", c->name);
-	if (IS_ERR(t)) {
-		bch_err(c, "error creating copygc thread: %li", PTR_ERR(t));
-		return PTR_ERR(t);
+	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);
@@ -363,6 +250,6 @@ int bch2_copygc_start(struct bch_fs *c)
 
 void bch2_fs_copygc_init(struct bch_fs *c)
 {
-	bch2_pd_controller_init(&c->copygc_pd);
-	c->copygc_pd.d_term = 0;
+	init_waitqueue_head(&c->copygc_running_wq);
+	c->copygc_running = false;
 }