Commit 968feb85 authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcachefs: Convert for_each_btree_node() to lockrestart_do() 



for_each_btree_node() now works similarly to for_each_btree_key(), where
the loop body is passed as an argument to be passed to lockrestart_do().

This now calls trans_begin() on every loop iteration - which fixes an
SRCU warning in backpointers fsck.

Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent 48d6cc1b

fs/bcachefs/backpointers.c

+5 −10
Original line number Diff line number Diff line
@@ -763,27 +763,22 @@ static int bch2_get_btree_in_memory_pos(struct btree_trans *trans, 
	     btree < BTREE_ID_NR && !ret;

	     btree++) {

		unsigned depth = (BIT_ULL(btree) & btree_leaf_mask) ? 0 : 1;

		struct btree_iter iter;

		struct btree *b;



		if (!(BIT_ULL(btree) & btree_leaf_mask) &&

		    !(BIT_ULL(btree) & btree_interior_mask))

			continue;



		bch2_trans_begin(trans);



		__for_each_btree_node(trans, iter, btree,

		ret = __for_each_btree_node(trans, iter, btree,

				      btree == start.btree ? start.pos : POS_MIN,

				      0, depth, BTREE_ITER_prefetch, b, ret) {

				      0, depth, BTREE_ITER_prefetch, b, ({

			mem_may_pin -= btree_buf_bytes(b);

			if (mem_may_pin <= 0) {

				c->btree_cache.pinned_nodes_end = *end =

					BBPOS(btree, b->key.k.p);

				bch2_trans_iter_exit(trans, &iter);

				return 0;

			}

				break;

			}

		bch2_trans_iter_exit(trans, &iter);

			0;

		}));

	}



	return ret;

fs/bcachefs/btree_iter.c

+1 −0
Original line number Diff line number Diff line
@@ -1900,6 +1900,7 @@ struct btree *bch2_btree_iter_peek_node(struct btree_iter *iter) 
	goto out;

}



/* Only kept for -tools */

struct btree *bch2_btree_iter_peek_node_and_restart(struct btree_iter *iter)

{

	struct btree *b;

fs/bcachefs/btree_iter.h

+27 −15
Original line number Diff line number Diff line
@@ -600,23 +600,35 @@ void bch2_trans_srcu_unlock(struct btree_trans *); 


u32 bch2_trans_begin(struct btree_trans *);



/*

 * XXX

 * this does not handle transaction restarts from bch2_btree_iter_next_node()

 * correctly

 */

#define __for_each_btree_node(_trans, _iter, _btree_id, _start,			\

			      _locks_want, _depth, _flags, _b, _ret)	\

	for (bch2_trans_node_iter_init((_trans), &(_iter), (_btree_id),	\

			      _locks_want, _depth, _flags, _b, _do)		\

({										\

	bch2_trans_begin((_trans));						\

										\

	struct btree_iter _iter;						\

	bch2_trans_node_iter_init((_trans), &_iter, (_btree_id),		\

				  _start, _locks_want, _depth, _flags);		\

	     (_b) = bch2_btree_iter_peek_node_and_restart(&(_iter)),	\

	     !((_ret) = PTR_ERR_OR_ZERO(_b)) && (_b);			\

	     (_b) = bch2_btree_iter_next_node(&(_iter)))

	int _ret3 = 0;								\

	do {									\

		_ret3 = lockrestart_do((_trans), ({				\

			struct btree *_b = bch2_btree_iter_peek_node(&_iter);	\

			if (!_b)						\

				break;						\

										\

			PTR_ERR_OR_ZERO(_b) ?: (_do);				\

		})) ?:								\

		lockrestart_do((_trans),					\

			PTR_ERR_OR_ZERO(bch2_btree_iter_next_node(&_iter)));	\

	} while (!_ret3);							\

										\

	bch2_trans_iter_exit((_trans), &(_iter));				\

	_ret3;									\

})



#define for_each_btree_node(_trans, _iter, _btree_id, _start,		\

			    _flags, _b, _ret)				\

			    _flags, _b, _do)				\

	__for_each_btree_node(_trans, _iter, _btree_id, _start,	\

			      0, 0, _flags, _b, _ret)

			      0, 0, _flags, _b, _do)



static inline struct bkey_s_c bch2_btree_iter_peek_prev_type(struct btree_iter *iter,

							     unsigned flags)

fs/bcachefs/debug.c

+9 −29
Original line number Diff line number Diff line
@@ -397,47 +397,27 @@ static ssize_t bch2_read_btree_formats(struct file *file, char __user *buf, 
				       size_t size, loff_t *ppos)

{

	struct dump_iter *i = file->private_data;

	struct btree_trans *trans;

	struct btree_iter iter;

	struct btree *b;

	ssize_t ret;



	i->ubuf = buf;

	i->size	= size;

	i->ret	= 0;



	ret = flush_buf(i);

	ssize_t ret = flush_buf(i);

	if (ret)

		return ret;



	if (bpos_eq(SPOS_MAX, i->from))

		return i->ret;



	trans = bch2_trans_get(i->c);

retry:

	bch2_trans_begin(trans);



	for_each_btree_node(trans, iter, i->id, i->from, 0, b, ret) {

	return bch2_trans_run(i->c,

		for_each_btree_node(trans, iter, i->id, i->from, 0, b, ({

			bch2_btree_node_to_text(&i->buf, i->c, b);

			i->from = !bpos_eq(SPOS_MAX, b->key.k.p)

				? bpos_successor(b->key.k.p)

				: b->key.k.p;



		ret = drop_locks_do(trans, flush_buf(i));

		if (ret)

			break;

	}

	bch2_trans_iter_exit(trans, &iter);



	if (bch2_err_matches(ret, BCH_ERR_transaction_restart))

		goto retry;



	bch2_trans_put(trans);



	if (!ret)

		ret = flush_buf(i);



	return ret ?: i->ret;

			drop_locks_do(trans, flush_buf(i));

		}))) ?: i->ret;

}



static const struct file_operations btree_format_debug_ops = {