bcachefs: bch2_btree_iter_peek() now works with interior nodes

Needed by the next patch, which will be iterating over keys in nodes at
level 1.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/btree_iter.c b/fs/bcachefs/btree_iter.c
index 7ea29724985067281bdeb81cae6a27f1348b1f4d..baf8ed40280ce7ccb4cfd8f5c24bbcd8a556fb90 100644 (file)
--- a/fs/bcachefs/btree_iter.c
+++ b/fs/bcachefs/btree_iter.c
@@ -1862,10 +1862,12 @@ static struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter, struct bp
        struct bkey_s_c k, k2;
        int ret;
 
-       EBUG_ON(iter->path->cached || iter->path->level);
+       EBUG_ON(iter->path->cached);
        bch2_btree_iter_verify(iter);
 
        while (1) {
+               struct btree_path_level *l;
+
                iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key,
                                        iter->flags & BTREE_ITER_INTENT);
 
@@ -1877,9 +1879,18 @@ static struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter, struct bp
                        goto out;
                }
 
+               l = path_l(iter->path);
+
+               if (unlikely(!l->b)) {
+                       /* No btree nodes at requested level: */
+                       bch2_btree_iter_set_pos(iter, SPOS_MAX);
+                       k = bkey_s_c_null;
+                       goto out;
+               }
+
                btree_path_set_should_be_locked(iter->path);
 
-               k = btree_path_level_peek_all(trans->c, &iter->path->l[0], &iter->k);
+               k = btree_path_level_peek_all(trans->c, l, &iter->k);
 
                if (unlikely(iter->flags & BTREE_ITER_WITH_KEY_CACHE) &&
                    k.k &&
@@ -1899,7 +1910,7 @@ static struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter, struct bp
 
                if (next_update &&
                    bpos_cmp(next_update->k.p,
-                            k.k ? k.k->p : iter->path->l[0].b->key.k.p) <= 0) {
+                            k.k ? k.k->p : l->b->key.k.p) <= 0) {
                        iter->k = next_update->k;
                        k = bkey_i_to_s_c(next_update);
                }
@@ -1920,9 +1931,9 @@ static struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter, struct bp
 
                if (likely(k.k)) {
                        break;
-               } else if (likely(bpos_cmp(iter->path->l[0].b->key.k.p, SPOS_MAX))) {
+               } else if (likely(bpos_cmp(l->b->key.k.p, SPOS_MAX))) {
                        /* Advance to next leaf node: */
-                       search_key = bpos_successor(iter->path->l[0].b->key.k.p);
+                       search_key = bpos_successor(l->b->key.k.p);
                } else {
                        /* End of btree: */
                        bch2_btree_iter_set_pos(iter, SPOS_MAX);