bcachefs: Improve alloc_mem_to_key()

This moves some common code into alloc_mem_to_key(), which translates
from the in-memory format for a bucket to the btree key format.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

fs/bcachefs/alloc_background.c

@@ -393,9 +393,6 @@ static int bch2_alloc_write_key(struct btree_trans *trans,
 {
 	struct bch_fs *c = trans->c;
 	struct bkey_s_c k;
-	struct bch_dev *ca;
-	struct bucket *g;
-	struct bucket_mark m;
 	struct bkey_alloc_unpacked old_u, new_u;
 	int ret;
 retry:
@@ -411,14 +408,8 @@ static int bch2_alloc_write_key(struct btree_trans *trans,
 	if (ret)
 		goto err;
 
-	old_u = bch2_alloc_unpack(k);
-
-	percpu_down_read(&c->mark_lock);
-	ca	= bch_dev_bkey_exists(c, iter->pos.inode);
-	g	= bucket(ca, iter->pos.offset);
-	m	= READ_ONCE(g->mark);
-	new_u	= alloc_mem_to_key(iter, g, m);
-	percpu_up_read(&c->mark_lock);
+	old_u	= bch2_alloc_unpack(k);
+	new_u	= alloc_mem_to_key(c, iter);
 
 	if (!bkey_alloc_unpacked_cmp(old_u, new_u))
 		return 0;
@@ -470,9 +461,7 @@ int bch2_bucket_io_time_reset(struct btree_trans *trans, unsigned dev,
 			      size_t bucket_nr, int rw)
 {
 	struct bch_fs *c = trans->c;
-	struct bch_dev *ca = bch_dev_bkey_exists(c, dev);
 	struct btree_iter iter;
-	struct bucket *g;
 	struct bkey_alloc_unpacked u;
 	u64 *time, now;
 	int ret = 0;
@@ -485,10 +474,7 @@ int bch2_bucket_io_time_reset(struct btree_trans *trans, unsigned dev,
 	if (ret)
 		goto out;
 
-	percpu_down_read(&c->mark_lock);
-	g = bucket(ca, bucket_nr);
-	u = alloc_mem_to_key(&iter, g, READ_ONCE(g->mark));
-	percpu_up_read(&c->mark_lock);
+	u = alloc_mem_to_key(c, &iter);
 
 	time = rw == READ ? &u.read_time : &u.write_time;
 	now = atomic64_read(&c->io_clock[rw].now);
@@ -766,8 +752,6 @@ static int bucket_invalidate_btree(struct btree_trans *trans,
 {
 	struct bch_fs *c = trans->c;
 	struct bkey_alloc_unpacked u;
-	struct bucket *g;
-	struct bucket_mark m;
 	struct btree_iter iter;
 	int ret;
 
@@ -781,11 +765,7 @@ static int bucket_invalidate_btree(struct btree_trans *trans,
 	if (ret)
 		goto err;
 
-	percpu_down_read(&c->mark_lock);
-	g = bucket(ca, b);
-	m = READ_ONCE(g->mark);
-	u = alloc_mem_to_key(&iter, g, m);
-	percpu_up_read(&c->mark_lock);
+	u = alloc_mem_to_key(c, &iter);
 
 	u.gen++;
 	u.data_type	= 0;

fs/bcachefs/alloc_background.h

@@ -4,7 +4,9 @@
 
 #include "bcachefs.h"
 #include "alloc_types.h"
+#include "buckets.h"
 #include "debug.h"
+#include "super.h"
 
 extern const char * const bch2_allocator_states[];
 
@@ -43,22 +45,31 @@ int bch2_alloc_write(struct btree_trans *, struct btree_iter *,
 int bch2_bucket_io_time_reset(struct btree_trans *, unsigned, size_t, int);
 
 static inline struct bkey_alloc_unpacked
-alloc_mem_to_key(struct btree_iter *iter,
-		 struct bucket *g, struct bucket_mark m)
+alloc_mem_to_key(struct bch_fs *c, struct btree_iter *iter)
 {
-	return (struct bkey_alloc_unpacked) {
+	struct bch_dev *ca;
+	struct bucket *g;
+	struct bkey_alloc_unpacked ret;
+
+	percpu_down_read(&c->mark_lock);
+	ca	= bch_dev_bkey_exists(c, iter->pos.inode);
+	g	= bucket(ca, iter->pos.offset);
+	ret	= (struct bkey_alloc_unpacked) {
 		.dev		= iter->pos.inode,
 		.bucket		= iter->pos.offset,
-		.gen		= m.gen,
+		.gen		= g->mark.gen,
 		.oldest_gen	= g->oldest_gen,
-		.data_type	= m.data_type,
-		.dirty_sectors	= m.dirty_sectors,
-		.cached_sectors	= m.cached_sectors,
+		.data_type	= g->mark.data_type,
+		.dirty_sectors	= g->mark.dirty_sectors,
+		.cached_sectors	= g->mark.cached_sectors,
 		.read_time	= g->io_time[READ],
 		.write_time	= g->io_time[WRITE],
 		.stripe		= g->stripe,
 		.stripe_redundancy = g->stripe_redundancy,
 	};
+	percpu_up_read(&c->mark_lock);
+
+	return ret;
 }
 
 #define ALLOC_SCAN_BATCH(ca)		max_t(size_t, 1, (ca)->mi.nbuckets >> 9)

fs/bcachefs/buckets.c

@@ -1492,7 +1492,6 @@ static int bch2_trans_start_alloc_update(struct btree_trans *trans, struct btree
 	struct bch_fs *c = trans->c;
 	struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev);
 	struct bpos pos = POS(ptr->dev, PTR_BUCKET_NR(ca, ptr));
-	struct bucket *g;
 	struct bkey_i *update;
 	int ret;
 
@@ -1507,14 +1506,9 @@ static int bch2_trans_start_alloc_update(struct btree_trans *trans, struct btree
 	}
 
 	update = __bch2_btree_trans_peek_updates(iter);
-	if (update && !bpos_cmp(update->k.p, pos)) {
-		*u = bch2_alloc_unpack(bkey_i_to_s_c(update));
-	} else {
-		percpu_down_read(&c->mark_lock);
-		g = bucket(ca, pos.offset);
-		*u = alloc_mem_to_key(iter, g, READ_ONCE(g->mark));
-		percpu_up_read(&c->mark_lock);
-	}
+	*u = update && !bpos_cmp(update->k.p, pos)
+		? bch2_alloc_unpack(bkey_i_to_s_c(update))
+		: alloc_mem_to_key(c, iter);
 
 	return 0;
 }