Commit 49771a75 authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcachefs: Fix bch2_btree_path_traverse_cached() when paths realloced 



btree_key_cache_fill() will allocate and traverse another path (for the
underlying btree), so we can't hold pointers to paths across a call - we
have to pass indices.

Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent 9c09e59c

fs/bcachefs/btree_iter.c

+1 −1
Original line number Diff line number Diff line
@@ -1162,7 +1162,7 @@ int bch2_btree_path_traverse_one(struct btree_trans *trans, 
	}



	if (path->cached) {

		ret = bch2_btree_path_traverse_cached(trans, path, flags);

		ret = bch2_btree_path_traverse_cached(trans, path_idx, flags);

		goto out;

	}

fs/bcachefs/btree_key_cache.c

+17 −8
Original line number Diff line number Diff line
@@ -301,9 +301,11 @@ static noinline_for_stack void do_trace_key_cache_fill(struct btree_trans *trans 
}



static noinline int btree_key_cache_fill(struct btree_trans *trans,

					 struct btree_path *ck_path,

					 btree_path_idx_t ck_path_idx,

					 unsigned flags)

{

	struct btree_path *ck_path = trans->paths + ck_path_idx;



	if (flags & BTREE_ITER_cached_nofill) {

		ck_path->l[0].b = NULL;

		return 0;
@@ -325,6 +327,7 @@ static noinline int btree_key_cache_fill(struct btree_trans *trans, 
		goto err;



	/* Recheck after btree lookup, before allocating: */

	ck_path = trans->paths + ck_path_idx;

	ret = bch2_btree_key_cache_find(c, ck_path->btree_id, ck_path->pos) ? -EEXIST : 0;

	if (unlikely(ret))

		goto out;
@@ -344,10 +347,11 @@ static noinline int btree_key_cache_fill(struct btree_trans *trans, 
}



static inline int btree_path_traverse_cached_fast(struct btree_trans *trans,

						  struct btree_path *path)

						  btree_path_idx_t path_idx)

{

	struct bch_fs *c = trans->c;

	struct bkey_cached *ck;

	struct btree_path *path = trans->paths + path_idx;

retry:

	ck = bch2_btree_key_cache_find(c, path->btree_id, path->pos);

	if (!ck)
@@ -373,27 +377,32 @@ static inline int btree_path_traverse_cached_fast(struct btree_trans *trans, 
	return 0;

}



int bch2_btree_path_traverse_cached(struct btree_trans *trans, struct btree_path *path,

int bch2_btree_path_traverse_cached(struct btree_trans *trans,

				    btree_path_idx_t path_idx,

				    unsigned flags)

{

	EBUG_ON(path->level);



	path->l[1].b = NULL;

	EBUG_ON(trans->paths[path_idx].level);



	int ret;

	do {

		ret = btree_path_traverse_cached_fast(trans, path);

		ret = btree_path_traverse_cached_fast(trans, path_idx);

		if (unlikely(ret == -ENOENT))

			ret = btree_key_cache_fill(trans, path, flags);

			ret = btree_key_cache_fill(trans, path_idx, flags);

	} while (ret == -EEXIST);



	struct btree_path *path = trans->paths + path_idx;



	if (unlikely(ret)) {

		path->uptodate = BTREE_ITER_NEED_TRAVERSE;

		if (!bch2_err_matches(ret, BCH_ERR_transaction_restart)) {

			btree_node_unlock(trans, path, 0);

			path->l[0].b = ERR_PTR(ret);

		}

	} else {

		BUG_ON(path->uptodate);

		BUG_ON(!path->nodes_locked);

	}



	return ret;

}

fs/bcachefs/btree_key_cache.h

+1 −2
Original line number Diff line number Diff line
@@ -40,8 +40,7 @@ int bch2_btree_key_cache_journal_flush(struct journal *, 
struct bkey_cached *

bch2_btree_key_cache_find(struct bch_fs *, enum btree_id, struct bpos);



int bch2_btree_path_traverse_cached(struct btree_trans *, struct btree_path *,

				    unsigned);

int bch2_btree_path_traverse_cached(struct btree_trans *, btree_path_idx_t, unsigned);



bool bch2_btree_insert_key_cached(struct btree_trans *, unsigned,

			struct btree_insert_entry *);