bcachefs: Fix btree node merging on write buffer btrees

The btree write buffer flush fastpath that avoids the main transaction
commit path had the unfortunate side effect of not doing btree node
merging.

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

diff --git a/fs/bcachefs/btree_write_buffer.c b/fs/bcachefs/btree_write_buffer.c
index baf63e2fddb64cd8f4c745d0cc80c864c86ffaa6..36a6f42aba5e6fc5a36418c1d7565e07e8f90420 100644 (file)
--- a/fs/bcachefs/btree_write_buffer.c
+++ b/fs/bcachefs/btree_write_buffer.c
@@ -316,6 +316,16 @@ static int bch2_btree_write_buffer_flush_locked(struct btree_trans *trans)
                            bpos_gt(k->k.k.p, path->l[0].b->key.k.p)) {
                                bch2_btree_node_unlock_write(trans, path, path->l[0].b);
                                write_locked = false;
+
+                               ret = lockrestart_do(trans,
+                                       bch2_btree_iter_traverse(&iter) ?:
+                                       bch2_foreground_maybe_merge(trans, iter.path, 0,
+                                                       BCH_WATERMARK_reclaim|
+                                                       BCH_TRANS_COMMIT_journal_reclaim|
+                                                       BCH_TRANS_COMMIT_no_check_rw|
+                                                       BCH_TRANS_COMMIT_no_enospc));
+                               if (ret)
+                                       goto err;
                        }
                }
 
@@ -382,10 +392,10 @@ static int bch2_btree_write_buffer_flush_locked(struct btree_trans *trans)
 
                        ret = commit_do(trans, NULL, NULL,
                                        BCH_WATERMARK_reclaim|
+                                       BCH_TRANS_COMMIT_journal_reclaim|
                                        BCH_TRANS_COMMIT_no_check_rw|
                                        BCH_TRANS_COMMIT_no_enospc|
-                                       BCH_TRANS_COMMIT_no_journal_res|
-                                       BCH_TRANS_COMMIT_journal_reclaim,
+                                       BCH_TRANS_COMMIT_no_journal_res ,
                                        btree_write_buffered_insert(trans, i));
                        if (ret)
                                goto err;