bcachefs: Kill BTREE_ITER_SET_POS_AFTER_COMMIT

BTREE_ITER_SET_POS_AFTER_COMMIT is used internally to automagically
advance extent btree iterators on sucessful commit.

But with the upcomnig btree_path patch it's getting more awkward to
support, and it adds overhead to core data structures that's only used
in a few places, and can be easily done by the caller instead.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

fs/bcachefs/btree_iter.c

@@ -2347,7 +2347,6 @@ static void btree_iter_copy(struct btree_trans *trans, struct btree_iter *dst,
 					   __btree_lock_want(dst, i));
 
 	dst->flags &= ~BTREE_ITER_KEEP_UNTIL_COMMIT;
-	dst->flags &= ~BTREE_ITER_SET_POS_AFTER_COMMIT;
 	trans->iters_sorted = false;
 }
 
@@ -2564,8 +2563,7 @@ void bch2_trans_begin(struct btree_trans *trans)
 	struct btree_iter *iter;
 
 	trans_for_each_iter(trans, iter)
-		iter->flags &= ~(BTREE_ITER_KEEP_UNTIL_COMMIT|
-				 BTREE_ITER_SET_POS_AFTER_COMMIT);
+		iter->flags &= ~BTREE_ITER_KEEP_UNTIL_COMMIT;
 
 	/*
 	 * XXX: we shouldn't be doing this if the transaction was restarted, but

fs/bcachefs/btree_types.h

@@ -211,11 +211,10 @@ enum btree_iter_type {
 #define BTREE_ITER_IS_EXTENTS		(1 << 6)
 #define BTREE_ITER_NOT_EXTENTS		(1 << 7)
 #define BTREE_ITER_ERROR		(1 << 8)
-#define BTREE_ITER_SET_POS_AFTER_COMMIT	(1 << 9)
-#define BTREE_ITER_CACHED_NOFILL	(1 << 10)
-#define BTREE_ITER_CACHED_NOCREATE	(1 << 11)
-#define BTREE_ITER_WITH_UPDATES		(1 << 12)
-#define BTREE_ITER_ALL_SNAPSHOTS	(1 << 13)
+#define BTREE_ITER_CACHED_NOFILL	(1 << 9)
+#define BTREE_ITER_CACHED_NOCREATE	(1 << 10)
+#define BTREE_ITER_WITH_UPDATES		(1 << 11)
+#define BTREE_ITER_ALL_SNAPSHOTS	(1 << 12)
 
 enum btree_iter_uptodate {
 	BTREE_ITER_UPTODATE		= 0,
@@ -256,7 +255,6 @@ struct btree_iter {
 
 	struct bpos		pos;
 	struct bpos		real_pos;
-	struct bpos		pos_after_commit;
 
 	enum btree_id		btree_id:4;
 	enum btree_iter_uptodate uptodate:3;

fs/bcachefs/btree_update_leaf.c

@@ -742,7 +742,6 @@ bch2_trans_commit_get_rw_cold(struct btree_trans *trans)
 int __bch2_trans_commit(struct btree_trans *trans)
 {
 	struct btree_insert_entry *i = NULL;
-	struct btree_iter *iter;
 	bool trans_trigger_run;
 	unsigned u64s;
 	int ret = 0;
@@ -840,11 +839,6 @@ int __bch2_trans_commit(struct btree_trans *trans)
 
 	if (ret)
 		goto err;
-
-	trans_for_each_iter(trans, iter)
-		if (btree_iter_live(trans, iter) &&
-		    (iter->flags & BTREE_ITER_SET_POS_AFTER_COMMIT))
-			bch2_btree_iter_set_pos(iter, iter->pos_after_commit);
 out:
 	bch2_journal_preres_put(&trans->c->journal, &trans->journal_preres);
 
@@ -920,9 +914,6 @@ static int bch2_trans_update_extent(struct btree_trans *trans,
 	enum btree_id btree_id = orig_iter->btree_id;
 	int ret = 0, compressed_sectors;
 
-	orig_iter->pos_after_commit = insert->k.p;
-	orig_iter->flags |= BTREE_ITER_SET_POS_AFTER_COMMIT;
-
 	iter = bch2_trans_get_iter(trans, btree_id, start,
 				   BTREE_ITER_INTENT|
 				   BTREE_ITER_WITH_UPDATES|

fs/bcachefs/ec.c

@@ -824,6 +824,7 @@ static int ec_stripe_update_ptrs(struct bch_fs *c,
 	struct bkey_s_c k;
 	struct bkey_s_extent e;
 	struct bkey_buf sk;
+	struct bpos next_pos;
 	int ret = 0, dev, block;
 
 	bch2_bkey_buf_init(&sk);
@@ -863,10 +864,14 @@ static int ec_stripe_update_ptrs(struct bch_fs *c,
 		extent_stripe_ptr_add(e, s, ec_ptr, block);
 
 		bch2_btree_iter_set_pos(iter, bkey_start_pos(&sk.k->k));
+		next_pos = sk.k->k.p;
+
 		ret   = bch2_btree_iter_traverse(iter) ?:
 			bch2_trans_update(&trans, iter, sk.k, 0) ?:
 			bch2_trans_commit(&trans, NULL, NULL,
 					BTREE_INSERT_NOFAIL);
+		if (!ret)
+			bch2_btree_iter_set_pos(iter, next_pos);
 		if (ret == -EINTR)
 			ret = 0;
 		if (ret)

fs/bcachefs/io.c

@@ -276,6 +276,7 @@ int bch2_extent_update(struct btree_trans *trans,
 {
 	/* this must live until after bch2_trans_commit(): */
 	struct bkey_inode_buf inode_p;
+	struct bpos next_pos;
 	bool extending = false, usage_increasing;
 	s64 i_sectors_delta = 0, disk_sectors_delta = 0;
 	int ret;
@@ -354,6 +355,8 @@ int bch2_extent_update(struct btree_trans *trans,
 			return ret;
 	}
 
+	next_pos = k->k.p;
+
 	ret =   bch2_trans_update(trans, iter, k, 0) ?:
 		bch2_trans_commit(trans, disk_res, journal_seq,
 				BTREE_INSERT_NOCHECK_RW|
@@ -362,6 +365,8 @@ int bch2_extent_update(struct btree_trans *trans,
 	if (ret)
 		return ret;
 
+	bch2_btree_iter_set_pos(iter, next_pos);
+
 	if (i_sectors_delta_total)
 		*i_sectors_delta_total += i_sectors_delta;
 	return 0;

fs/bcachefs/move.c

@@ -79,6 +79,7 @@ int bch2_migrate_index_update(struct bch_write_op *op)
 		struct bkey_i_extent *new;
 		const union bch_extent_entry *entry;
 		struct extent_ptr_decoded p;
+		struct bpos next_pos;
 		bool did_work = false;
 		bool extending = false, should_check_enospc;
 		s64 i_sectors_delta = 0, disk_sectors_delta = 0;
@@ -162,14 +163,18 @@ int bch2_migrate_index_update(struct bch_write_op *op)
 				goto out;
 		}
 
+		next_pos = insert->k.p;
+
 		ret   = bch2_trans_update(&trans, iter, insert, 0) ?:
 			bch2_trans_commit(&trans, &op->res,
 				op_journal_seq(op),
 				BTREE_INSERT_NOFAIL|
 				m->data_opts.btree_insert_flags);
-err:
-		if (!ret)
+		if (!ret) {
+			bch2_btree_iter_set_pos(iter, next_pos);
 			atomic_long_inc(&c->extent_migrate_done);
+		}
+err:
 		if (ret == -EINTR)
 			ret = 0;
 		if (ret)