Commit 3b8c4507 authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcachefs: btree_trans->write_locked 



As prep work for the next patch to fix a key cache reclaim issue, we
need to start tracking whether we're currently holding write locks - so
that we can release and retake the before calling into memory reclaim.

Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent c65c13f0

fs/bcachefs/btree_trans_commit.c

+49 −36
Original line number Diff line number Diff line
@@ -78,6 +78,53 @@ inline void bch2_btree_node_prep_for_write(struct btree_trans *trans, 
		bch2_btree_init_next(trans, b);

}



static noinline int trans_lock_write_fail(struct btree_trans *trans, struct btree_insert_entry *i)

{

	while (--i >= trans->updates) {

		if (same_leaf_as_prev(trans, i))

			continue;



		bch2_btree_node_unlock_write(trans, i->path, insert_l(i)->b);

	}



	trace_and_count(trans->c, trans_restart_would_deadlock_write, trans);

	return btree_trans_restart(trans, BCH_ERR_transaction_restart_would_deadlock_write);

}



static inline int bch2_trans_lock_write(struct btree_trans *trans)

{

	struct btree_insert_entry *i;



	EBUG_ON(trans->write_locked);



	trans_for_each_update(trans, i) {

		if (same_leaf_as_prev(trans, i))

			continue;



		if (bch2_btree_node_lock_write(trans, i->path, &insert_l(i)->b->c))

			return trans_lock_write_fail(trans, i);



		if (!i->cached)

			bch2_btree_node_prep_for_write(trans, i->path, insert_l(i)->b);

	}



	trans->write_locked = true;

	return 0;

}



static inline void bch2_trans_unlock_write(struct btree_trans *trans)

{

	if (likely(trans->write_locked)) {

		struct btree_insert_entry *i;



		trans_for_each_update(trans, i)

			if (!same_leaf_as_prev(trans, i))

				bch2_btree_node_unlock_write_inlined(trans, i->path,

								     insert_l(i)->b);

		trans->write_locked = false;

	}

}



/* Inserting into a given leaf node (last stage of insert): */



/* Handle overwrites and do insert, for non extents: */
@@ -732,37 +779,6 @@ bch2_trans_commit_write_locked(struct btree_trans *trans, unsigned flags, 
	return ret;

}



static noinline int trans_lock_write_fail(struct btree_trans *trans, struct btree_insert_entry *i)

{

	while (--i >= trans->updates) {

		if (same_leaf_as_prev(trans, i))

			continue;



		bch2_btree_node_unlock_write(trans, i->path, insert_l(i)->b);

	}



	trace_and_count(trans->c, trans_restart_would_deadlock_write, trans);

	return btree_trans_restart(trans, BCH_ERR_transaction_restart_would_deadlock_write);

}



static inline int trans_lock_write(struct btree_trans *trans)

{

	struct btree_insert_entry *i;



	trans_for_each_update(trans, i) {

		if (same_leaf_as_prev(trans, i))

			continue;



		if (bch2_btree_node_lock_write(trans, i->path, &insert_l(i)->b->c))

			return trans_lock_write_fail(trans, i);



		if (!i->cached)

			bch2_btree_node_prep_for_write(trans, i->path, insert_l(i)->b);

	}



	return 0;

}



static noinline void bch2_drop_overwrites_from_journal(struct btree_trans *trans)

{

	struct btree_insert_entry *i;
@@ -838,7 +854,7 @@ static inline int do_bch2_trans_commit(struct btree_trans *trans, unsigned flags 
	if (unlikely(ret))

		return ret;



	ret = trans_lock_write(trans);

	ret = bch2_trans_lock_write(trans);

	if (unlikely(ret))

		return ret;
@@ -847,10 +863,7 @@ static inline int do_bch2_trans_commit(struct btree_trans *trans, unsigned flags 
	if (!ret && unlikely(trans->journal_replay_not_finished))

		bch2_drop_overwrites_from_journal(trans);



	trans_for_each_update(trans, i)

		if (!same_leaf_as_prev(trans, i))

			bch2_btree_node_unlock_write_inlined(trans, i->path,

							insert_l(i)->b);

	bch2_trans_unlock_write(trans);



	if (!ret && trans->journal_pin)

		bch2_journal_pin_add(&c->journal, trans->journal_res.seq,

fs/bcachefs/btree_types.h

+1 −0
Original line number Diff line number Diff line
@@ -409,6 +409,7 @@ struct btree_trans { 
	bool			journal_transaction_names:1;

	bool			journal_replay_not_finished:1;

	bool			notrace_relock_fail:1;

	bool			write_locked:1;

	enum bch_errcode	restarted:16;

	u32			restart_count;

	unsigned long		last_begin_ip;