bcachefs: bch2_btree_path_upgrade() checks nodes_locked, not uptodate

In the key cache fill path, we use path_upgrade() on a path that isn't
uptodate yet but should be locked.

This change makes bch2_btree_path_upgrade() slightly looser so we can
use it in key cache upgrade, instead of the __ version.

Also, make the related assert - that path->uptodate implies nodes_locked
- slightly clearer.

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

1 files changed, 6 insertions, 7 deletions

diff --git a/fs/bcachefs/btree_locking.c b/fs/bcachefs/btree_locking.c
index e6adb2df3a57..9a3ab56f6cfc 100644
--- a/fs/bcachefs/btree_locking.c
+++ b/fs/bcachefs/btree_locking.c
@@ -840,20 +840,19 @@ int __bch2_trans_mutex_lock(struct btree_trans *trans,
 
 void bch2_btree_path_verify_locks(struct btree_path *path)
 {
-	unsigned l;
-
 	/*
 	 * A path may be uptodate and yet have nothing locked if and only if
 	 * there is no node at path->level, which generally means we were
 	 * iterating over all nodes and got to the end of the btree
 	 */
-	if (!path->nodes_locked) {
-		BUG_ON(path->uptodate == BTREE_ITER_UPTODATE &&
-		       btree_path_node(path, path->level));
+	BUG_ON(path->uptodate == BTREE_ITER_UPTODATE &&
+	       btree_path_node(path, path->level) &&
+	       !path->nodes_locked);
+
+	if (!path->nodes_locked)
 		return;
-	}
 
-	for (l = 0; l < BTREE_MAX_DEPTH; l++) {
+	for (unsigned l = 0; l < BTREE_MAX_DEPTH; l++) {
 		int want = btree_lock_want(path, l);
 		int have = btree_node_locked_type(path, l);