Hello guys, I met a bug. Mount dfs root share failed on v5.11.0-rc5. But It's success on v5.10. [root@ibm-x3650m4-01-vm-14 ~]# mount -vvv //localhost/dfsroot cifs -o user=root,password=redhat mount.cifs kernel mount options: ip=::1,unc=\\localhost\dfsroot,user=root,pass=******** mount error(22): Invalid argument dmesg log: [ 1648.025424] CIFS: fs/cifs/connect.c: build_unc_path_to_root: full_path=\\localhost\dfsroot [ 1648.025427] CIFS: fs/cifs/connect.c: build_unc_path_to_root: full_path=\\localhost\dfsroot [ 1648.025429] CIFS: fs/cifs/connect.c: build_unc_path_to_root: full_path=\\localhost\dfsroot [ 1648.025434] CIFS: fs/cifs/dfs_cache.c: __dfs_cache_find: search path: \localhost\dfsroot [ 1648.025437] CIFS: fs/cifs/dfs_cache.c: setup_referral: set up new ref [ 1648.026760] CIFS: fs/cifs/dns_resolve.c: dns_resolve_server_name_to_ip: resolved: localhost to 127.0.0.1 [ 1648.026773] CIFS: VFS: No username specified [ 1648.028008] CIFS: fs/cifs/connect.c: cifs_put_smb_ses: ses_count=3 [ 1648.028012] CIFS: fs/cifs/connect.c: cifs_put_tcon: tc_count=1 [ 1648.028014] CIFS: fs/cifs/connect.c: VFS: in cifs_put_tcon as Xid: 32 with uid: 0 [ 1648.028017] CIFS: fs/cifs/smb2pdu.c: Tree Disconnect [ 1648.028385] CIFS: fs/cifs/connect.c: cifs_put_smb_ses: ses_count=2 [ 1648.028390] CIFS: fs/cifs/connect.c: VFS: leaving mount_put_conns (xid = 29) rc = 0 [ 1648.028393] CIFS: VFS: cifs_mount failed w/return code = -22 More info please look https://bugzilla.kernel.org/show_bug.cgi?id=211345. Thanks. -- Best regards! XiaoLi Feng 冯小丽 Red Hat Software (Beijing) Co.,Ltd filesystem-qe Team IRC:xifeng,#channel: fs-qe Tel:+86-10-8388112 9/F, Raycom