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 8bfd19cbcfaad791a21feeb7348724b1ab4faeeb..1c720953800ce4dc0c6571da72e60971cb3c17c1 100644 (file)
--- a/src/mds/Server.cc
+++ b/src/mds/Server.cc
@@ -5830,6 +5830,11 @@ void Server::handle_client_mkdir(MDRequestRef& mdr)
   le->metablob.add_opened_ino(newi->ino());
 
   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);
 }