Commit 6ec8623f authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcachefs: btree node scan: fall back to comparing by journal seq 



highly damaged filesystems, or filesystems that have been damaged and
repair and damaged again, may have sequence numbers we can't fully trust
- which in itself is something we need to debug.

Add a journal_seq fallback so that repair doesn't get stuck.

Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent 375476c4

fs/bcachefs/btree_io.c

+4 −0
Original line number Diff line number Diff line
@@ -1006,6 +1006,7 @@ int bch2_btree_node_read_done(struct bch_fs *c, struct bch_dev *ca, 
		BTREE_PTR_RANGE_UPDATED(&bkey_i_to_btree_ptr_v2(&b->key)->v);

	unsigned u64s;

	unsigned ptr_written = btree_ptr_sectors_written(bkey_i_to_s_c(&b->key));

	u64 max_journal_seq = 0;

	struct printbuf buf = PRINTBUF;

	int ret = 0, retry_read = 0, write = READ;

	u64 start_time = local_clock();
@@ -1181,6 +1182,8 @@ int bch2_btree_node_read_done(struct bch_fs *c, struct bch_dev *ca, 
		sort_iter_add(iter,

			      vstruct_idx(i, 0),

			      vstruct_last(i));



		max_journal_seq = max(max_journal_seq, le64_to_cpu(i->journal_seq));

	}



	if (ptr_written) {
@@ -1217,6 +1220,7 @@ int bch2_btree_node_read_done(struct bch_fs *c, struct bch_dev *ca, 
	swap(sorted, b->data);

	set_btree_bset(b, b->set, &b->data->keys);

	b->nsets = 1;

	b->data->keys.journal_seq = cpu_to_le64(max_journal_seq);



	BUG_ON(b->nr.live_u64s != u64s);

fs/bcachefs/btree_node_scan.c

+36 −15
Original line number Diff line number Diff line
@@ -22,7 +22,9 @@ struct find_btree_nodes_worker { 


static void found_btree_node_to_text(struct printbuf *out, struct bch_fs *c, const struct found_btree_node *n)

{

	prt_printf(out, "%s l=%u seq=%u cookie=%llx ", bch2_btree_id_str(n->btree_id), n->level, n->seq, n->cookie);

	prt_printf(out, "%s l=%u seq=%u journal_seq=%llu cookie=%llx ",

		   bch2_btree_id_str(n->btree_id), n->level, n->seq,

		   n->journal_seq, n->cookie);

	bch2_bpos_to_text(out, n->min_key);

	prt_str(out, "-");

	bch2_bpos_to_text(out, n->max_key);
@@ -63,19 +65,37 @@ static void found_btree_node_to_key(struct bkey_i *k, const struct found_btree_n 
	memcpy(bp->v.start, f->ptrs, sizeof(struct bch_extent_ptr) * f->nr_ptrs);

}



static inline u64 bkey_journal_seq(struct bkey_s_c k)

{

	switch (k.k->type) {

	case KEY_TYPE_inode_v3:

		return le64_to_cpu(bkey_s_c_to_inode_v3(k).v->bi_journal_seq);

	default:

		return 0;

	}

}



static bool found_btree_node_is_readable(struct btree_trans *trans,

					 struct found_btree_node *f)

{

	struct { __BKEY_PADDED(k, BKEY_BTREE_PTR_VAL_U64s_MAX); } k;

	struct { __BKEY_PADDED(k, BKEY_BTREE_PTR_VAL_U64s_MAX); } tmp;



	found_btree_node_to_key(&k.k, f);

	found_btree_node_to_key(&tmp.k, f);



	struct btree *b = bch2_btree_node_get_noiter(trans, &k.k, f->btree_id, f->level, false);

	struct btree *b = bch2_btree_node_get_noiter(trans, &tmp.k, f->btree_id, f->level, false);

	bool ret = !IS_ERR_OR_NULL(b);

	if (!ret)

		return ret;



	f->sectors_written = b->written;

	f->journal_seq = le64_to_cpu(b->data->keys.journal_seq);



	struct bkey_s_c k;

	struct bkey unpacked;

	struct btree_node_iter iter;

	for_each_btree_node_key_unpack(b, k, &iter, &unpacked)

		f->journal_seq = max(f->journal_seq, bkey_journal_seq(k));



	six_unlock_read(&b->c.lock);



	/*
@@ -84,7 +104,7 @@ static bool found_btree_node_is_readable(struct btree_trans *trans, 
	 * this node

	 */

	if (b != btree_node_root(trans->c, b))

		bch2_btree_node_evict(trans, &k.k);

		bch2_btree_node_evict(trans, &tmp.k);

	return ret;

}
@@ -105,7 +125,8 @@ static int found_btree_node_cmp_cookie(const void *_l, const void *_r) 
static int found_btree_node_cmp_time(const struct found_btree_node *l,

				     const struct found_btree_node *r)

{

	return cmp_int(l->seq, r->seq);

	return  cmp_int(l->seq, r->seq) ?:

		cmp_int(l->journal_seq, r->journal_seq);

}



static int found_btree_node_cmp_pos(const void *_l, const void *_r)
@@ -309,15 +330,15 @@ static int handle_overwrites(struct bch_fs *c, 
		} else if (n->level) {

			n->overwritten = true;

		} else {

			struct printbuf buf = PRINTBUF;



			prt_str(&buf, "overlapping btree nodes with same seq! halting\n  ");

			found_btree_node_to_text(&buf, c, start);

			prt_str(&buf, "\n  ");

			found_btree_node_to_text(&buf, c, n);

			bch_err(c, "%s", buf.buf);

			printbuf_exit(&buf);

			return -BCH_ERR_fsck_repair_unimplemented;

			if (bpos_cmp(start->max_key, n->max_key) >= 0)

				n->overwritten = true;

			else {

				n->range_updated = true;

				n->min_key = bpos_successor(start->max_key);

				n->range_updated = true;

				bubble_up(n, end);

				goto again;

			}

		}

	}

fs/bcachefs/btree_node_scan_types.h

+1 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ struct found_btree_node { 
	u8			level;

	unsigned		sectors_written;

	u32			seq;

	u64			journal_seq;

	u64			cookie;



	struct bpos		min_key;