bcachefs: Another should_be_locked fixup

When returning a key from the key cache, in BTREE_ITER_WITH_KEY_CACHE
mode, we don't want to set should_be_locked on iter->path; we're not
returning a key from that path, so we donn't need to, and also since we
traversed the key cache iterator before setting should_be_locked on that
path it might be unlocked (if we unlocked, bch2_trans_relock() won't
have relocked it).

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

diff --git a/fs/bcachefs/btree_iter.c b/fs/bcachefs/btree_iter.c
index a464327..0c6e215 100644 (file)
--- a/fs/bcachefs/btree_iter.c
+++ b/fs/bcachefs/btree_iter.c
@@ -2334,7 +2334,7 @@ struct bkey_s_c btree_trans_peek_journal(struct btree_trans *trans,
  * bkey_s_c_null:
  */
 static noinline
-struct bkey_s_c btree_trans_peek_key_cache(struct btree_iter *iter, struct bpos pos)
+struct bkey_s_c __btree_trans_peek_key_cache(struct btree_iter *iter, struct bpos pos)
 {
        struct btree_trans *trans = iter->trans;
        struct bch_fs *c = trans->c;
@@ -2361,6 +2361,15 @@ struct bkey_s_c btree_trans_peek_key_cache(struct btree_iter *iter, struct bpos
        return bch2_btree_path_peek_slot(iter->key_cache_path, &u);
 }
 
+static noinline
+struct bkey_s_c btree_trans_peek_key_cache(struct btree_iter *iter, struct bpos pos)
+{
+       struct bkey_s_c ret = __btree_trans_peek_key_cache(iter, pos);
+       int err = bkey_err(ret) ?: bch2_btree_path_relock(iter->trans, iter->path, _THIS_IP_);
+
+       return err ? bkey_s_c_err(err) : ret;
+}
+
 static struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter, struct bpos search_key)
 {
        struct btree_trans *trans = iter->trans;
@@ -2390,15 +2399,12 @@ static struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter, struct bp
                if (unlikely(iter->flags & BTREE_ITER_WITH_KEY_CACHE) &&
                    k.k &&
                    (k2 = btree_trans_peek_key_cache(iter, k.k->p)).k) {
-                       ret = bkey_err(k2);
+                       k = k2;
+                       ret = bkey_err(k);
                        if (ret) {
-                               k = k2;
                                bch2_btree_iter_set_pos(iter, iter->pos);
                                goto out;
                        }
-
-                       k = k2;
-                       iter->k = *k.k;
                }
 
                if (unlikely(iter->flags & BTREE_ITER_WITH_JOURNAL))
@@ -2857,13 +2863,11 @@ struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *iter)
                        goto out;
 
                if (unlikely(iter->flags & BTREE_ITER_WITH_KEY_CACHE) &&
-                   (k = btree_trans_peek_key_cache(iter, iter->pos)).k) {
-                       if (bkey_err(k)) {
-                               goto out_no_locked;
-                       } else {
+                   (k = __btree_trans_peek_key_cache(iter, iter->pos)).k) {
+                       if (!bkey_err(k))
                                iter->k = *k.k;
-                               goto out;
-                       }
+                       /* We're not returning a key from iter->path: */
+                       goto out_no_locked;
                }
 
                k = bch2_btree_path_peek_slot(iter->path, &iter->k);