From f42238b5cde2f1624b2be5f64c813e6127a8012a Mon Sep 17 00:00:00 2001
From: Kent Overstreet <kent.overstreet@linux.dev>
Date: Wed, 12 Oct 2022 07:58:50 -0400
Subject: [PATCH] bcachefs: Fix a rare path in bch2_btree_path_peek_slot()
In the drop_alloc tests, we may end up calling
bch2_btree_iter_peek_slot() on an interior level that doesn't exist.
Previously, this would hit the path->uptodate assertion in
bch2_btree_path_peek_slot(); this path first checks a NULL btree node,
which is how we know we're at the end of the btree.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
---
fs/bcachefs/btree_iter.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/fs/bcachefs/btree_iter.c b/fs/bcachefs/btree_iter.c
index 283764225d133..0bb156e6152a0 100644
--- a/fs/bcachefs/btree_iter.c
+++ b/fs/bcachefs/btree_iter.c
@@ -1544,14 +1544,17 @@ struct btree_path *bch2_path_get(struct btree_trans *trans,
inline struct bkey_s_c bch2_btree_path_peek_slot(struct btree_path *path, struct bkey *u)
{
+ struct btree_path_level *l = path_l(path);
+ struct bkey_packed *_k;
struct bkey_s_c k;
- if (!path->cached) {
- struct btree_path_level *l = path_l(path);
- struct bkey_packed *_k;
+ if (unlikely(!l->b))
+ return bkey_s_c_null;
- EBUG_ON(path->uptodate != BTREE_ITER_UPTODATE);
+ EBUG_ON(path->uptodate != BTREE_ITER_UPTODATE);
+ EBUG_ON(!btree_node_locked(path, path->level));
+ if (!path->cached) {
_k = bch2_btree_node_iter_peek_all(&l->iter, l->b);
k = _k ? bkey_disassemble(l->b, _k, u) : bkey_s_c_null;
@@ -1566,7 +1569,6 @@ inline struct bkey_s_c bch2_btree_path_peek_slot(struct btree_path *path, struct
(path->btree_id != ck->key.btree_id ||
bkey_cmp(path->pos, ck->key.pos)));
EBUG_ON(!ck || !ck->valid);
- EBUG_ON(path->uptodate != BTREE_ITER_UPTODATE);
*u = ck->k->k;
k = bkey_i_to_s_c(ck->k);
@@ -2381,6 +2383,8 @@ struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *iter)
}
k = bch2_btree_path_peek_slot(iter->path, &iter->k);
+ if (unlikely(!k.k))
+ goto out_no_locked;
} else {
struct bpos next;
@@ -2412,7 +2416,7 @@ struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *iter)
}
if (unlikely(bkey_err(k)))
- return k;
+ goto out_no_locked;
next = k.k ? bkey_start_pos(k.k) : POS_MAX;
--
2.30.2