bcachefs: Fix btree lock being incorrectly dropped

__btree_trans_get_iter() was using bch2_btree_iter_upgrade, but it
shouldn't have been because on failure bch2_btree_iter_upgrade may drop
locks in other iterators, expecting the transaction to be restarted. But
__btree_trans_get_iter can't return an error to indicate that we need to
restart thet transaction - oops.

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

diff --git a/fs/bcachefs/btree_iter.c b/fs/bcachefs/btree_iter.c
index c0333ee94463f45b7f041516a49e681612f60828..15963a657c72e726ec94ccfd4f96c6fb67855799 100644 (file)
--- a/fs/bcachefs/btree_iter.c
+++ b/fs/bcachefs/btree_iter.c
@@ -2124,9 +2124,12 @@ static struct btree_iter *__btree_trans_get_iter(struct btree_trans *trans,
        iter->flags &= ~BTREE_ITER_USER_FLAGS;
        iter->flags |= flags & BTREE_ITER_USER_FLAGS;
 
-       if (iter->flags & BTREE_ITER_INTENT)
-               bch2_btree_iter_upgrade(iter, 1);
-       else
+       if (iter->flags & BTREE_ITER_INTENT) {
+               if (!iter->locks_want) {
+                       __bch2_btree_iter_unlock(iter);
+                       iter->locks_want = 1;
+               }
+       } else
                bch2_btree_iter_downgrade(iter);
 
        BUG_ON(iter->btree_id != btree_id);

diff --git a/fs/bcachefs/btree_update_leaf.c b/fs/bcachefs/btree_update_leaf.c
index e27ec0fbee2c5d6042dcf6db69061541ae8f3eb0..a2ec2e58f9e43743fef5b2c1dc3133c6678fbcc1 100644 (file)
--- a/fs/bcachefs/btree_update_leaf.c
+++ b/fs/bcachefs/btree_update_leaf.c
@@ -869,8 +869,8 @@ int __bch2_trans_commit(struct btree_trans *trans)
                trans_trigger_run = false;
 
                trans_for_each_update(trans, i) {
-                       if (unlikely(i->iter->uptodate > BTREE_ITER_NEED_PEEK &&
-                                    (ret = bch2_btree_iter_traverse(i->iter)))) {
+                       ret = bch2_btree_iter_traverse(i->iter);
+                       if (unlikely(ret)) {
                                trace_trans_restart_traverse(trans->ip);
                                goto out;
                        }
@@ -879,8 +879,8 @@ int __bch2_trans_commit(struct btree_trans *trans)
                         * We're not using bch2_btree_iter_upgrade here because
                         * we know trans->nounlock can't be set:
                         */
-                       if (unlikely(i->iter->locks_want < 1 &&
-                                    !__bch2_btree_iter_upgrade(i->iter, 1))) {
+                       if (unlikely(!btree_node_intent_locked(i->iter, i->iter->level) &&
+                                    !__bch2_btree_iter_upgrade(i->iter, i->iter->level + 1))) {
                                trace_trans_restart_upgrade(trans->ip);
                                ret = -EINTR;
                                goto out;