mds: check dir fragment to split dir if mkdir makes it oversized.

In handle_client_mkdir we hit_dir (via hit_inode) in mkdir finish callback, but by then we might have overshot the split size (multiple mkdir in flight), so check dir fragment for an early chance to split the dir if mkdir makes it oversized.

Fixes: https://tracker.ceph.com/issues/39166
Signed-off-by: Erqi Chen <bestchenerqi@126.com>
(cherry picked from commit 01b4818c26b744ef74ccb09586ec03478f6b1b61)

diff --git a/src/mds/Server.cc b/src/mds/Server.cc
index 2249d317300c35aea7107968f4d3e958d97d7595..183b2714f984a00299661bfd7e7df5c727443930 100644 (file)
--- a/src/mds/Server.cc
+++ b/src/mds/Server.cc
@@ -5460,6 +5460,11 @@ void Server::handle_client_mkdir(MDRequestRef& mdr)
   ls->open_files.push_back(&newi->item_open_file);
 
   journal_and_reply(mdr, newi, dn, le, new C_MDS_mknod_finish(this, mdr, dn, newi));
+
+  // We hit_dir (via hit_inode) in our finish callback, but by then we might
+  // have overshot the split size (multiple mkdir in flight), so here is
+  // an early chance to split the dir if this mkdir makes it oversized.
+  mds->balancer->maybe_fragment(dir, false);
 }